FXUS66 KMFR 291200 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 400 AM PST SUN DEC 29 2013 .DISCUSSION...HI RESOLUTION SPORT MODIS-VIIRS NIGHTTIME MICRO-PHYSICS RGB SATELLITE IMAGERY IS SHOWING A DEEPER MOIST LAYER NORTH OF THE UMPQUA DIVIDE COMPARED TO THE LAST COUPLE OF NIGHTS. AS A RESULT, THE CLOUD LAYER IS MORE STRATUS THAN FOG NEAR ROSEBURG THIS MORNING. HOWEVER, IT IS LIKELY THAT DENSE FOG WILL BE ENCOUNTERED AT HIGHER ELEVATIONS SURROUNDING ROSEBURG...ESPECIALLY NEAR CAMAS MOUNTAIN AND ALSO THE PASSES SOUTH OF THE CITY NEAR CANYONVILLE. FOR THIS REASON, HAVE MAINTAINED THE DENSE FOG ADVISORY THROUGH MID MORNING. A SHALLOWER MOIST LAYER IS EVIDENT IN THE ROGUE VALLEY WITH SURFACE OBSERVATIONS AND AREA WEB CAMS INDICATING WIDESPREAD FREEZING FOG FROM GRANTS PASS TO MEDFORD. A FREEZING FOG ADVISORY IS OUT FOR THESE LOCATIONS. THE SOUTH ENDS OF BOTH THE ILLINOIS VALLEY AND ROGUE VALLEY HAVE REMAINED MOSTLY CLEAR OVERNIGHT WITH TEMPERATURES AT THIS EARLY HOUR IN THE LOW TO MID 20S. WITH THE RIDGE AT ITS STRONGEST TODAY, NOT EXPECTING MUCH MIXING OUT OF THE MOIST LAYER IN THE LOW LEVELS, SO WE'LL REMAIN COLD IN THE LOW CLOUDS/FOG HERE IN MEDFORD WITH HIGHS ONLY IN THE MID 30S. ASHLAND THOUGH SHOULD GET SOME SOUTHEAST WIND TODAY TO WARM INTO THE 40S. MEANWHILE, OFFSHORE FLOW WILL BRING PLENTY OF SUNSHINE WITH WARM AND DRY CONDITIONS TO THE MID SLOPES AND RIDGES AROUND THE AREA. THE BROOKINGS EFFECT WILL BE IN FULL FORCE TODAY AND IS ALREADY WITH TEMPS IN THE LOW 60S AT 3AM! MODEL 975 TEMPS ARE INDICATING AROUND 17C THIS AFTERNOON AND THIS SHOULD RESULT IN HIGHS THERE IN THE LOW TO MID 70S. OFFSHORE FLOW WILL WEAKEN SIGNIFICANTLY TONIGHT AND THE RIDGE WILL BEGIN TO FLATTEN ON MONDAY. EVEN SO, THERE IS STILL NO APPRECIABLE MIXING TO SCOUR OUT THESE LOW CLOUDS/FOG. SO, EXPECT ANOTHER DISMAL DAY AROUND MEDFORD. SLIGHTLY COOLER AIR MOVING IN ALOFT AND A GENERAL INCREASE IN MID AND HIGH CLOUDS SHOULD BRING SEVERAL DEGREES OF COOLING TO THE SURROUNDING HILLS. IT WILL ALSO BE A COOLER DAY ALONG THE SOUTH COAST AS THE LOW LEVEL FLOW TURNS SOUTHERLY AND MORE MARINE AIR RETURNS. THE FLOW ALOFT WILL BECOME MORE WESTERLY AND A WEAK DISTURBANCE WILL ZIP OFF TO OUR NORTH MONDAY NIGHT INTO TUESDAY. PRECIPITATION CHANCES ARE SLIGHT AT BEST WITH THIS FEATURE, BUT THERE MAY BE A LITTLE LIGHT RAIN IN COOS OR DOUGLAS COUNTIES. THIS SYSTEM SHOULD CAUSE MORE MIXING AND WEAKEN THE INVERSION TUESDAY. FOR NOW, HAVE KEPT THE FORECAST ON THE PESSIMISTIC SIDE WITH CLOUDS/PATCHY FOG REMAINING IN SOME OF THE VALLEYS THROUGH THE DAY. SHORT WAVE RIDGING IS EXPECTED NEW YEARS EVE INTO NEW YEARS DAY, SO IT'LL BE DRY. OPERATIONAL MODELS AND ENSEMBLE GUIDANCE INDICATE THE RIDGE PERSISTING INTO THURSDAY, BUT ALL INDICATE A SHIFT IN THE PATTERN TOWARD THE END OF THE WEEK WITH A SHORTWAVE TROUGH MOVING ONSHORE FRIDAY WITH BETTER PRECIPITATION CHANCES THAN WE'VE SEEN IN AWHILE. IT IS STILL TOO EARLY TO SAY IF THIS IS A TREND TOWARD A MORE ACTIVE PATTERN NEXT WEEKEND OR IF THE RIDGE THAT HAS BEEN SO PERSISTENT REBUILDS OFFSHORE AGAIN. WE'LL BE TAKING A CLOSER LOOK AT THIS OVER THE NEXT COUPLE OF DAYS. SPILDE && .AVIATION...A PERSISTENT PATTERN CONTINUES THROUGH THROUGH SUNDAY EVENING WITH HIGH PRESSURE OVER THE AREA BRINGING INLAND VALLEY FOG AND FREEZING FOG WEST OF THE CASCADES. WIDESPREAD IFR/LIFR CIGS AND AREAS OF IFR/LIFR VSBYS WILL CONTINUE IN THE UMPQUA, ILLINOIS, APPLEGATE AND ROGUE VALLEYS INTO SUNDAY AFTERNOON. FOG MAY PARTIALLY CLEAR IN THE LATE AFTERNOON AND CIGS MAY LIFT SLIGHTLY. HOWEVER CIGS AND VSBYS WILL BE LOWEST AND ALSO SLOWEST TO IMPROVE ON SUNDAY IN THE ROGUE VALLEY. ANY IMPROVEMENT AT KMFR INTO EARLY SUNDAY AFTERNOON WILL BE DUE TO FOG SEEDING. LATER SUNDAY AFTERNOON...AS WITH THE PAST FEW DAYS...THERE WILL BE PARTIAL IMPROVEMENT. HOWEVER AREAS OF VALLEY IFR/MVFR CIGS AND VSBYS ARE EXPECTED IN THE UMPQUA, ROGUE, ILLINOIS AND APPLEGATE VALLEYS. THEN SUNDAY EVENING EXPECT A RETURN OF WIDESPREAD VALLEY IFR/LIFR CIGS AND VISIBILITIES IN FOR FOR THESE AREAS ONCE AGAIN. ELSEWHERE...WHICH INCLUDES THE COAST, SISKIYOU COUNTY AND THE AREA EAST OF THE CASCADES...EXPECT VFR CONDITIONS WITH MAINLY CLEAR SKIES. CC && .MFR WATCHES/WARNINGS/ADVISORIES... OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST WEDNESDAY FOR ORZ023>026. DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ023. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS AFTERNOON FOR ORZ022. FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ024-026. AIR STAGNATION ADVISORY UNTIL 10 AM PST WEDNESDAY FOR ORZ029>031. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS AFTERNOON FOR PZZ350-356. SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR PZZ370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST MONDAY FOR PZZ370-376. HAZARDOUS SEAS WARNING UNTIL 4 PM PST THIS AFTERNOON FOR PZZ370-376. $$ MAS/FJB/CC  FXUS66 KMFR 291657 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 857 AM PST SUN DEC 29 2013 .DISCUSSION...CURRENT VISIBLE IMAGE SHOWS STRATUS OVER THE SAME LOCATIONS AS IN THE PAST FEW DAYS. THE MORNING SOUNDING SHOWS THE MOISTURE LAYER AROUND 1700 FEET WITH RAPID DRYING ABOVE THAT. THIS IS BEING SUPPORTED BY OBSERVATIONS OVER THE MID SLOPES AND RIDGES WHERE RELATIVE HUMIDITIES ARE LOW. THE FOG IN THE ROGUE VALLEY IS EXPECTED TO PERSIST THROUGH EARLY THIS AFTERNOON AND COULD LIFT TO A LOW OVERCAST BRIEFLY BEFORE FOG RETURNS EARLY THIS EVENING. THE WEATHER WILL BE PRETTY MUCH STATUS QUO THROUGH AT LEAST MID WEEK. THE RIDGE WILL FLATTEN OUT SOME MONDAY AND TUESDAY AS WEAK DISTURBANCES MOVE NORTH OF THE FORECAST AREA, BUT WILL HAVE LITTLE OR NO EFFECT FOR US. IT MAY NOT BE UNTIL THE END OF THE WEEK BEFORE WE SEE ANY SIGNIFICANT CHANGE TO OUR WEATHER. -PETRUCELLI && .AVIATION...BASED ON THE 29/12Z TAF CYCLE A PERSISTENT PATTERN CONTINUES FOR THE NEXT 24 HOURS WITH HIGH PRESSURE OVER THE AREA BRINGING INLAND VALLEY FOG AND FREEZING FOG WEST OF THE CASCADES. WIDESPREAD IFR/LIFR CIGS AND AREAS OF IFR/LIFR VSBYS WILL CONTINUE IN THE UMPQUA, ILLINOIS, APPLEGATE AND ROGUE VALLEYS INTO THIS AFTERNOON. FOG MAY PARTIALLY CLEAR IN THE LATE AFTERNOON AND CIGS MAY LIFT SLIGHTLY, BUT CIGS AND VSBYS WILL BE LOWEST AND ALSO SLOWEST TO IMPROVE THE ROGUE VALLEY. ANY IMPROVEMENT AT KMFR MAY ONLY BE FOR A COUPLE OF HOURS LATE THIS AFTERNOON BEFORE FOG RETURNS EARLY THIS EVENING. WIDESPREAD VALLEY IFR/LIFR CIGS AND VISIBILITIES RETURNS IN FOR FOR THESE AREAS ONCE AGAIN THIS EVENING AND TONIGHT. ELSEWHERE...WHICH INCLUDES THE COAST, SISKIYOU COUNTY AND THE AREA EAST OF THE CASCADES...EXPECT VFR CONDITIONS WITH MAINLY CLEAR SKIES. && .PREV DISCUSSION... /ISSUED 400 AM PST SUN DEC 29 2013/ DISCUSSION...HI RESOLUTION SPORT MODIS-VIIRS NIGHTTIME MICRO-PHYSICS RGB SATELLITE IMAGERY IS SHOWING A DEEPER MOIST LAYER NORTH OF THE UMPQUA DIVIDE COMPARED TO THE LAST COUPLE OF NIGHTS. AS A RESULT, THE CLOUD LAYER IS MORE STRATUS THAN FOG NEAR ROSEBURG THIS MORNING. HOWEVER, IT IS LIKELY THAT DENSE FOG WILL BE ENCOUNTERED AT HIGHER ELEVATIONS SURROUNDING ROSEBURG...ESPECIALLY NEAR CAMAS MOUNTAIN AND ALSO THE PASSES SOUTH OF THE CITY NEAR CANYONVILLE. FOR THIS REASON, HAVE MAINTAINED THE DENSE FOG ADVISORY THROUGH MID MORNING. A SHALLOWER MOIST LAYER IS EVIDENT IN THE ROGUE VALLEY WITH SURFACE OBSERVATIONS AND AREA WEB CAMS INDICATING WIDESPREAD FREEZING FOG FROM GRANTS PASS TO MEDFORD. A FREEZING FOG ADVISORY IS OUT FOR THESE LOCATIONS. THE SOUTH ENDS OF BOTH THE ILLINOIS VALLEY AND ROGUE VALLEY HAVE REMAINED MOSTLY CLEAR OVERNIGHT WITH TEMPERATURES AT THIS EARLY HOUR IN THE LOW TO MID 20S. WITH THE RIDGE AT ITS STRONGEST TODAY, NOT EXPECTING MUCH MIXING OUT OF THE MOIST LAYER IN THE LOW LEVELS, SO WE'LL REMAIN COLD IN THE LOW CLOUDS/FOG HERE IN MEDFORD WITH HIGHS ONLY IN THE MID 30S. ASHLAND THOUGH SHOULD GET SOME SOUTHEAST WIND TODAY TO WARM INTO THE 40S. MEANWHILE, OFFSHORE FLOW WILL BRING PLENTY OF SUNSHINE WITH WARM AND DRY CONDITIONS TO THE MID SLOPES AND RIDGES AROUND THE AREA. THE BROOKINGS EFFECT WILL BE IN FULL FORCE TODAY AND IS ALREADY WITH TEMPS IN THE LOW 60S AT 3AM! MODEL 975 TEMPS ARE INDICATING AROUND 17C THIS AFTERNOON AND THIS SHOULD RESULT IN HIGHS THERE IN THE LOW TO MID 70S. OFFSHORE FLOW WILL WEAKEN SIGNIFICANTLY TONIGHT AND THE RIDGE WILL BEGIN TO FLATTEN ON MONDAY. EVEN SO, THERE IS STILL NO APPRECIABLE MIXING TO SCOUR OUT THESE LOW CLOUDS/FOG. SO, EXPECT ANOTHER DISMAL DAY AROUND MEDFORD. SLIGHTLY COOLER AIR MOVING IN ALOFT AND A GENERAL INCREASE IN MID AND HIGH CLOUDS SHOULD BRING SEVERAL DEGREES OF COOLING TO THE SURROUNDING HILLS. IT WILL ALSO BE A COOLER DAY ALONG THE SOUTH COAST AS THE LOW LEVEL FLOW TURNS SOUTHERLY AND MORE MARINE AIR RETURNS. THE FLOW ALOFT WILL BECOME MORE WESTERLY AND A WEAK DISTURBANCE WILL ZIP OFF TO OUR NORTH MONDAY NIGHT INTO TUESDAY. PRECIPITATION CHANCES ARE SLIGHT AT BEST WITH THIS FEATURE, BUT THERE MAY BE A LITTLE LIGHT RAIN IN COOS OR DOUGLAS COUNTIES. THIS SYSTEM SHOULD CAUSE MORE MIXING AND WEAKEN THE INVERSION TUESDAY. FOR NOW, HAVE KEPT THE FORECAST ON THE PESSIMISTIC SIDE WITH CLOUDS/PATCHY FOG REMAINING IN SOME OF THE VALLEYS THROUGH THE DAY. SHORT WAVE RIDGING IS EXPECTED NEW YEARS EVE INTO NEW YEARS DAY, SO IT'LL BE DRY. OPERATIONAL MODELS AND ENSEMBLE GUIDANCE INDICATE THE RIDGE PERSISTING INTO THURSDAY, BUT ALL INDICATE A SHIFT IN THE PATTERN TOWARD THE END OF THE WEEK WITH A SHORTWAVE TROUGH MOVING ONSHORE FRIDAY WITH BETTER PRECIPITATION CHANCES THAN WE'VE SEEN IN AWHILE. IT IS STILL TOO EARLY TO SAY IF THIS IS A TREND TOWARD A MORE ACTIVE PATTERN NEXT WEEKEND OR IF THE RIDGE THAT HAS BEEN SO PERSISTENT REBUILDS OFFSHORE AGAIN. WE'LL BE TAKING A CLOSER LOOK AT THIS OVER THE NEXT COUPLE OF DAYS. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST WEDNESDAY FOR ORZ023>026. DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ023. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS AFTERNOON FOR ORZ022. FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ024-026. AIR STAGNATION ADVISORY UNTIL 10 AM PST WEDNESDAY FOR ORZ029>031. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THIS AFTERNOON FOR PZZ350-356. SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR PZZ370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST MONDAY FOR PZZ370-376. HAZARDOUS SEAS WARNING UNTIL 4 PM PST THIS AFTERNOON FOR PZZ370-376. $$  FXUS66 KMFR 211210 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 410 AM PST TUE JAN 21 2014 .SHORT TERM...THIS MORNING'S SPORT MODIS-VIIRS MICROPHYSICS IMAGERY DEPICTS VERY SIMILAR CONDITIONS COMPARED TO 24 HOURS AGO WITH FOG/LOW CLOUDS OVER THE WEST SIDE VALLEYS. SUBTLE DIFFERENCES ARE EVIDENT WITH LESS COVERAGE OF FOG THROUGH THE SOUTH END OF THE ROGUE VALLEY NEAR TALENT AND ASHLAND. BUT, ONE NOTABLE DIFFERENCE IS THE SURGE OF FOG/STRATUS NORTHWARD THROUGH THE COASTAL WATERS AND ALONG THE IMMEDIATE COAST. THIS IS BEING INDUCED BY A SHORT WAVE TROUGH APPROACHING 130 W AND THE ASSOCIATED SURFACE SOUTHERLIES AHEAD OF IT. A QUICK LOOK AT THE 12Z KMFR SOUNDING INDICATED THE MOIST LAYER DEPTH AT ABOUT 1000FT WITH RAPID DRYING ABOVE ABOUT 945MB. OVERALL, NOT EXPECTING MUCH CHANGE FROM YESTERDAY, EXCEPT PERHAPS A TAD EARLIER BREAK OUT TIMES. THE DEEPER "BOWLS" LIKE GRANTS PASS MAY TAKE THE LONGEST. IT APPEARS THICKEST THERE CURRENTLY. COASTAL AREAS WILL BE SLIGHTLY COOLER THAN YESTERDAY, BUT THE REST OF THE AREA WILL BE SUNNY AND MILD AGAIN. THE AFOREMENTIONED SHORT WAVE TROUGH WILL ZIP BY TO OUR NORTH THIS EVENING. NOT EXPECTING MUCH OUT OF THIS FEATURE...THERE IS A SLIGHT CHANCE OF LIGHT RAIN ALONG THE COAST...BUT THAT'S ALL IT IS...A SLIGHT CHANCE. BY WEDNESDAY...THE SHORT WAVE WILL DIG INTO THE INTERMOUNTAIN WEST AND THE RIDGE WILL REBUILD ALONG 130 W. WITH SURFACE HIGH PRESSURE BUILDING OFFSHORE AND A THERMAL TROUGH DEVELOPING OVER NORTHERN CALIFORNIA...EXPECT ANOTHER ROUND OF OFFSHORE FLOW WEDNESDAY NIGHT INTO THURSDAY. RIGHT NOW, IT APPEARS WINDS WILL BE 15-25 MPH WITH SOME HIGHER GUSTS ON THE MID SLOPES AND RIDGES WITH RH RECOVERIES 30-35% IN SW OREGON AND WESTERN SISKIYOU COUNTY. A SECOND SHORT WAVE DISTURBANCE WILL DIVE SOUTHWARD FROM BRITISH COLUMBIA AND RETROGRADE OVER NORTHERN CALIFORNIA THURSDAY INTO FRIDAY. THIS SYSTEM IS MOISTURE STARVED SO PRECIPITATION IS UNLIKELY...BUT IT WILL KEEP THE OFFSHORE FLOW EVENT GOING THURSDAY NIGHT INTO FRIDAY MORNING. THIS MAY NOT BE THAT NOTABLE IN A NORMAL YEAR, BUT SINCE WE HAVE BEEN VERY DRY SO FAR THIS SEASON, THIS MAY RESULT IN FIRE WEATHER CONCERNS DUE TO THE WINDS AND LOW RHS. BEYOND THAT, OFFSHORE FLOW WILL EASE THIS WEEKEND AND WE'LL REMAIN UNDER THE INFLUENCE OF THE WEST COAST RIDGE, RESULTING IN A CONTINUED DRY PATTERN. IT WON'T BE UNTIL SOMETIME NEXT WEEK WHERE A PACIFIC SYSTEM MAY BE ABLE BREAK THROUGH AND BRING SOME RAIN TO THE AREA. RIGHT NOW...IT LOOKS LIKE THE BEST CHANCE FOR THIS TO OCCUR WOULD BE MONDAY NIGHT INTO TUESDAY. SPILDE && .AVIATION...A SURGE OF FOG AND STRATUS HAS MOVED ONSHORE FROM CHARLESTON SOUTHWARD BUT REMAINS OFFSHORE NORTH OF COOS BAY. KOTH REMAINS VFR AT THIS TIME...BUT STRATUS MAY APPROACH THE AREA LATER THIS MORNING. LIFR CIGS/VSBYS PREVAIL IN THE STRATUS. AREAS OF LIFR CIGS/VSBYS HAVE DEVELOPED OVER THE UMPQUA...ILLINOIS...AND ROGUE VALLEYS AS WELL...INCLUDING KRBG AND KMFR. EXPECT ALL THESE AREAS TO CLEAR TO VFR TUESDAY AFTERNOON...EXCEPT UNDER THE STRATUS OFFSHORE. EXPECT THE LOWER CONDITIONS TO RETURN TO THE SAME WEST SIDE VALLEYS ALONG WITH THE ENTIRE COAST TUESDAY EVENING. ELSEWHERE...VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY EVENING. STOCKTON && .MARINE...ANOTHER ROUND OF LONG PERIOD MODERATE WEST SWELL IS NOW PEAKING AND WILL SUBSIDE INTO TUESDAY. OTHERWISE...HIGH PRESSURE CENTERED OVER INTERIOR BRITISH COLUMBIA WILL RECENTER INLAND OVER THE INTER-MOUNTAIN WEST MONDAY THROUGH TUESDAY CONTINUING SOUTHERLY WINDS. A WEAK FRONT WILL BRUSH BY TUESDAY NIGHT. THE RETURN OF OFFSHORE HIGH PRESSURE WILL LEAD TO STRONGER NORTH WINDS WEDNESDAY INTO THURSDAY. WINDS WILL BECOME OFFSHORE THURSDAY INTO FRIDAY AS HIGH PRESSURE DEVELOPS INLAND. BTL/STOCKTON && .CLIMATE...THE 3 PRIMARY OPERATIONAL MODELS NOW, FOR THE FIRST TIME IN THE LAST WEEK, INDICATE A BREAK DOWN IN THE BLOCKING HIGH PRESSURE RIDGE ALONG THE WEST COAST AROUND DAY 10, JANUARY 28TH. MODELS HAVE BEEN MOSTLY CONSISTENT IN TRENDING IN THIS DIRECTION FOR THE LAST SEVERAL DAYS, AND THERE IS GOOD REASON TO BELIEVE IN THIS TREND. A STRONG AREA OF DEEP TROPICAL CONVECTION IN AND AROUND INDONESIA HAS BEEN PERSISTING THROUGH THE WEEKEND AND IS EVER SO SLOWLY REFOCUSING EASTWARD TOWARD THE INTERNATIONAL DATELINE. THIS FEATURE IS REFLECTED IN FORECAST MJO INDICES. THIS FEATURE ALONG WITH A DIP IN THE JET STREAM COMING OFF OF THE COAST OF ASIA ARE EXPECTED TO SEND FORTH ENOUGH ENHANCED JET STREAM ENERGY ACROSS THE PACIFIC TO WEAKEN AND BUMP THE RIDGE ALONG THE WEST COAST. WHILE THE OPERATIONAL MODELS DO INDICATE A BREAKDOWN IN THE HIGH PRESSURE RIDGE IN PLACE, THEY DIFFER SUBSTANTIALLY ON RELATED DETAILS- PRIMARILY HOW FAST THIS BREAKDOWN OCCURS AND HOW FAST WE GET WET. THE CFS INDICATES THE WET PART WON'T BEGIN UNTIL THE WEEK THAT BEGINS FEBRUARY 2ND, WHEREAS THE FASTER OPERATIONAL ECMWF MODEL INDICATES A NOTABLE STORM ARRIVING ON THE 28TH OF JANUARY. BTL && .MFR WATCHES/WARNINGS/ADVISORIES... OR...DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ021-023. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ023-024-026. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ029>031. FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ024-026. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST WEDNESDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SATURDAY FOR PZZ370-376. $$ MAS/JRS/BTL/FJB  FXUS66 KMFR 211635 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 835 AM PST TUE JAN 21 2014 .SHORT TERM...THE CURRENT FORECAST REMAINS ON TRACK. AHEAD OF A SHORTWAVE TROUGH AND A WEAK FRONT, SOUTH WINDS OFFSHORE AND ALONG THE COAST HAVE BROUGHT A SURGE OF LOW STRATUS TO THE COAST THIS MORNING. INLAND, MORNING VALLEY FOG IS PRESENT IN THE WEST SIDE VALLEYS. AREAS OF DENSE FOG WITH LIMITED VISIBILITIES ARE ALSO PRESENT, ESPECIALLY IN THE VALLEYS IN DOUGLAS, JACKSON AND JOSEPHINE COUNTIES. VISIBILITIES ARE EXPECTED TO IMPROVE AROUND 10 AM PST THIS MORNING WITH CLEARING EXPECTED IN THE AFTERNOON. AS THE WEAK FRONT MOVES INTO THE COAST LATE THIS EVENING AND TONIGHT THERE IS A SLIGHT CHANCE FOR LIGHT RAIN ALONG THE COAST. OTHERWISE EXPECT HIGH PRESSURE TO PERSIST WITH VALLEY FOG REDEVELOPING TONIGHT AND WEDNESDAY MORNING. && .AVIATION...BASED ON THE 21/12Z TAF CYCLE. A SURGE OF FOG AND STRATUS HAS MOVED UP THE COAST TO AROUND FLORENCE OREGON WITH KOTH HAVING COME BELOW IFR EARLIER THIS MORNING. LIFR CIGS/VSBYS PREVAIL IN THE STRATUS. AREAS OF LIFR CIGS/VSBYS HAVE DEVELOPED OVER THE UMPQUA...ILLINOIS...APPLEGATE AND ROGUE VALLEYS AS WELL...INCLUDING KRBG AND KMFR. EXPECT ALL THESE AREAS TO CLEAR TO VFR THIS AFTERNOON. STRATUS WILL CONTINUE OFFSHORE. THEN EXPECT THE LOWER CONDITIONS TO RETURN TO THE SAME WEST SIDE VALLEYS ALONG WITH THE ENTIRE COAST THIS EVENING. ELSEWHERE...VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. && .MARINE...LONG PERIOD MODERATE WEST SWELL WILL GRADUALLY SUBSIDE THIS MORNING AND SHOULD FALL BELOW 10 FEET BY LATE THIS AFTERNOON. OTHERWISE...HIGH PRESSURE CENTERED OVER INTERIOR BRITISH COLUMBIA WILL RECENTER INLAND OVER THE INTER-MOUNTAIN WEST TODAY CONTINUING THE SOUTHERLY WINDS. A WEAK FRONT WILL BRUSH BY TONIGHT. THE RETURN OF OFFSHORE HIGH PRESSURE WILL LEAD TO STRONGER NORTH WINDS WEDNESDAY INTO THURSDAY. WINDS WILL BECOME OFFSHORE THURSDAY INTO FRIDAY AS HIGH PRESSURE DEVELOPS INLAND. /FB && .PREV DISCUSSION... /ISSUED 410 AM PST TUE JAN 21 2014/ SHORT TERM...THIS MORNING'S SPORT MODIS-VIIRS MICROPHYSICS IMAGERY DEPICTS VERY SIMILAR CONDITIONS COMPARED TO 24 HOURS AGO WITH FOG/LOW CLOUDS OVER THE WEST SIDE VALLEYS. SUBTLE DIFFERENCES ARE EVIDENT WITH LESS COVERAGE OF FOG THROUGH THE SOUTH END OF THE ROGUE VALLEY NEAR TALENT AND ASHLAND. BUT, ONE NOTABLE DIFFERENCE IS THE SURGE OF FOG/STRATUS NORTHWARD THROUGH THE COASTAL WATERS AND ALONG THE IMMEDIATE COAST. THIS IS BEING INDUCED BY A SHORT WAVE TROUGH APPROACHING 130 W AND THE ASSOCIATED SURFACE SOUTHERLIES AHEAD OF IT. A QUICK LOOK AT THE 12Z KMFR SOUNDING INDICATED THE MOIST LAYER DEPTH AT ABOUT 1000FT WITH RAPID DRYING ABOVE ABOUT 945MB. OVERALL, NOT EXPECTING MUCH CHANGE FROM YESTERDAY, EXCEPT PERHAPS A TAD EARLIER BREAK OUT TIMES. THE DEEPER "BOWLS" LIKE GRANTS PASS MAY TAKE THE LONGEST. IT APPEARS THICKEST THERE CURRENTLY. COASTAL AREAS WILL BE SLIGHTLY COOLER THAN YESTERDAY, BUT THE REST OF THE AREA WILL BE SUNNY AND MILD AGAIN. THE AFOREMENTIONED SHORT WAVE TROUGH WILL ZIP BY TO OUR NORTH THIS EVENING. NOT EXPECTING MUCH OUT OF THIS FEATURE...THERE IS A SLIGHT CHANCE OF LIGHT RAIN ALONG THE COAST...BUT THAT'S ALL IT IS...A SLIGHT CHANCE. BY WEDNESDAY...THE SHORT WAVE WILL DIG INTO THE INTERMOUNTAIN WEST AND THE RIDGE WILL REBUILD ALONG 130 W. WITH SURFACE HIGH PRESSURE BUILDING OFFSHORE AND A THERMAL TROUGH DEVELOPING OVER NORTHERN CALIFORNIA...EXPECT ANOTHER ROUND OF OFFSHORE FLOW WEDNESDAY NIGHT INTO THURSDAY. RIGHT NOW, IT APPEARS WINDS WILL BE 15-25 MPH WITH SOME HIGHER GUSTS ON THE MID SLOPES AND RIDGES WITH RH RECOVERIES 30-35% IN SW OREGON AND WESTERN SISKIYOU COUNTY. A SECOND SHORT WAVE DISTURBANCE WILL DIVE SOUTHWARD FROM BRITISH COLUMBIA AND RETROGRADE OVER NORTHERN CALIFORNIA THURSDAY INTO FRIDAY. THIS SYSTEM IS MOISTURE STARVED SO PRECIPITATION IS UNLIKELY...BUT IT WILL KEEP THE OFFSHORE FLOW EVENT GOING THURSDAY NIGHT INTO FRIDAY MORNING. THIS MAY NOT BE THAT NOTABLE IN A NORMAL YEAR, BUT SINCE WE HAVE BEEN VERY DRY SO FAR THIS SEASON, THIS MAY RESULT IN FIRE WEATHER CONCERNS DUE TO THE WINDS AND LOW RHS. BEYOND THAT, OFFSHORE FLOW WILL EASE THIS WEEKEND AND WE'LL REMAIN UNDER THE INFLUENCE OF THE WEST COAST RIDGE, RESULTING IN A CONTINUED DRY PATTERN. IT WON'T BE UNTIL SOMETIME NEXT WEEK WHERE A PACIFIC SYSTEM MAY BE ABLE BREAK THROUGH AND BRING SOME RAIN TO THE AREA. RIGHT NOW...IT LOOKS LIKE THE BEST CHANCE FOR THIS TO OCCUR WOULD BE MONDAY NIGHT INTO TUESDAY. SPILDE CLIMATE...THE 3 PRIMARY OPERATIONAL MODELS NOW, FOR THE FIRST TIME IN THE LAST WEEK, INDICATE A BREAK DOWN IN THE BLOCKING HIGH PRESSURE RIDGE ALONG THE WEST COAST AROUND DAY 10, JANUARY 28TH. MODELS HAVE BEEN MOSTLY CONSISTENT IN TRENDING IN THIS DIRECTION FOR THE LAST SEVERAL DAYS, AND THERE IS GOOD REASON TO BELIEVE IN THIS TREND. A STRONG AREA OF DEEP TROPICAL CONVECTION IN AND AROUND INDONESIA HAS BEEN PERSISTING THROUGH THE WEEKEND AND IS EVER SO SLOWLY REFOCUSING EASTWARD TOWARD THE INTERNATIONAL DATELINE. THIS FEATURE IS REFLECTED IN FORECAST MJO INDICES. THIS FEATURE ALONG WITH A DIP IN THE JET STREAM COMING OFF OF THE COAST OF ASIA ARE EXPECTED TO SEND FORTH ENOUGH ENHANCED JET STREAM ENERGY ACROSS THE PACIFIC TO WEAKEN AND BUMP THE RIDGE ALONG THE WEST COAST. WHILE THE OPERATIONAL MODELS DO INDICATE A BREAKDOWN IN THE HIGH PRESSURE RIDGE IN PLACE, THEY DIFFER SUBSTANTIALLY ON RELATED DETAILS- PRIMARILY HOW FAST THIS BREAKDOWN OCCURS AND HOW FAST WE GET WET. THE CFS INDICATES THE WET PART WON'T BEGIN UNTIL THE WEEK THAT BEGINS FEBRUARY 2ND, WHEREAS THE FASTER OPERATIONAL ECMWF MODEL INDICATES A NOTABLE STORM ARRIVING ON THE 28TH OF JANUARY. BTL && .MFR WATCHES/WARNINGS/ADVISORIES... OR...DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ021-023. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ023-024-026. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ029>031. FREEZING FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ024-026. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST WEDNESDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SATURDAY FOR PZZ370-376. $$ CC  FXUS66 KMFR 221145 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 345 AM PST WED JAN 22 2014 .DISCUSSION...MODIS-VIIRS NIGHTTIME MICROPHYSICS RGB SATELLITE IMAGERY VIA NASA/SPORT REVEALS PRETTY MUCH THE STATUS QUO THIS MORNING. COMPARED TO YESTERDAY'S SATELLITE IMAGE AT ABOUT THE SAME TIME, IT APPEARS NEARLY IDENTICAL WITH RESPECT TO WHERE THE LOW CLOUDS AND FOG ARE...JUST PERHAPS A SLIGHTLY SHALLOWER FOG IN PORTIONS OF THE ROGUE VALLEY. DENSE FOG ADVISORIES (NPWMFR) ARE UP FOR THE UMPQUA/ROGUE VALLEYS UNTIL 10 AM THIS MORNING. COULD ALSO BE SOME SLIPPERY SPOTS ON AREA ROADS WHERE TEMPERATURES HAVE FALLEN BELOW FREEZING. MOST AREAS BROKE OUT YESTERDAY WITH THE EXCEPTION OF GRANTS PASS. EXPECT A SIMILAR SCENARIO TODAY. AS A RESULT, HAVE NUDGED MAX TEMPS HIGHER IN MEDFORD...UP INTO THE LOW 50S...WHILE KEEPING GRANTS PASS DOWN CLOSER TO THE MID 40S. AN UPPER LEVEL SHORT WAVE WILL DIVE SOUTHEASTWARD INTO THE GREAT BASIN TODAY BRINGING SLIGHT COOLING ALOFT TO AREAS EAST OF THE CASCADES. THOSE AREAS SHOULD HAVE MAX TEMPS A FEW DEGREES LOWER THAN YESTERDAY. OFFSHORE FLOW WILL COMMENCE LATER TODAY AND TONIGHT AS THIS SYSTEM MOVES INTO UTAH AND SURFACE HIGH PRESSURE BUILDS TO THE NORTH. ANOTHER FAST-MOVING SHORT WAVE WILL DIVE SOUTHWARD THROUGH OREGON INTO NORTHERN CALIFORNIA TONIGHT INTO THURSDAY. A STRONG RIDGE WILL DEVELOP OFF THE BRITISH COLUMBIA COAST AND THIS WILL ALLOW THE SHORT WAVE TO DEVELOP INTO A CLOSED LOW AS IT MOVES WESTWARD OFFSHORE IN THE EASTERLY FLOW ALOFT. THIS SYSTEM HAS VIRTUALLY NO MOISTURE WITH IT, SO WE'RE NOT EXPECTING ANY PRECIPITATION. STRONG OFFSHORE FLOW DEVELOPS THURSDAY AND PEAKS THURSDAY NIGHT INTO FRIDAY AS A STRONG WEST-EAST SURFACE PRESSURE GRADIENT SETS UP. THIS WILL CAUSE GUSTY WINDS OVER THE EAST SIDE AND OVER THE MID SLOPES AND RIDGES FROM THE CASCADES WEST. DUE TO THE INCREASE IN WINDS AND EXPECTED MIXING, HAVE DECIDED TO END THE AIR STAGNATION ADVISORY EAST OF THE CASCADES A BIT SOONER...THURSDAY MORNING. OVER THE WEST SIDE VALLEYS, CONFIDENCE IS NOT HIGH IN WINDS REACHING THE SURFACE TO MIX OUT THE INVERSION, SO HAVE CONTINUED THE AIR STAGNATION ADVISORY THERE THROUGH EARLY SATURDAY. IT MAY NEED TO BE EXTENDED OR RE- ISSUED AS THE RIDGE ALOFT BUILDS OVERHEAD AGAIN THIS WEEKEND AND OFFSHORE FLOW EASES. THE RIDGE WILL HOLD THROUGH AT LEAST MONDAY, THEN A PACIFIC SYSTEM WILL ATTEMPT TO MOVE ONSHORE MONDAY NIGHT INTO TUESDAY. MODELS CONTINUE TO WAVER ON THE STRENGTH OF THIS SYSTEM, BUT RIGHT NOW MODELS APPEAR WEAK. HAVE MAINTAINED THE GOING FORECAST OF SLIGHT CHANCE TO CHANCE POPS...HIGHEST ON THE COAST. SPILDE && .AVIATION...MARINE STRATUS WITH MVFR CIGS REMAINS LOCKED IN ALONG THE NORTH COAST FROM ABOUT BANDON NORTHWARD. INLAND...FOG/LOW CLOUDS ARE IN NEARLY IDENTICAL LOCATIONS THAT THEY WERE YESTERDAY ACROSS THE WEST SIDE AND COASTAL VALLEYS. LIFR/IFR CIG AND VIS WILL IMPACT KMFR AND KRBG THROUGH THE MORNING BUT SHOULD BURN OFF TO AT LEAST MVFR IN ALL AREAS LATE THIS MORNING. ELSEWHERE, VFR CONDITIONS WILL CONTINUE THROUGH THURSDAY. -WRIGHT/SPILDE && .MARINE...LONG PERIOD MODERATE WEST SWELL BUILDS TONIGHT...SUBSIDE LATE WEDNESDAY...AND BUILD AGAIN LATE THURSDAY. BEHIND A VERY WEAK FRONT THIS EVENING...WINDS WILL INCREASE AND BECOME GUSTY FROM THE NORTH LATE WEDNESDAY INTO THURSDAY...WITH THE HIGHEST WIND SPEEDS IN THE SOUTHERN OUTER ZONE. HIGH PRESSURE LATE IN THE WEEK AND INTO THE WEEKEND WILL SWITCH WINDS TO THE SOUTH AT MAINLY LIGHT SPEEDS. CONFIDENCE IS HIGH THAT NO MAJOR STORMS WILL AFFECT THE COASTAL WATERS THROUGH THIS WEEKEND. SK && .FIRE WEATHER...A SIGNIFICANT OFFSHORE FLOW EVENT IS EXPECTED TO COMMENCE TODAY INCREASING TONIGHT INTO THURSDAY MORNING, THEN PEAKING THURSDAY INTO FRIDAY MORNING. THIS IS IN RESPONSE TO TWO STRONG SHORT WAVE DISTURBANCES TRACKING SOUTHWARD FROM BRITISH COLUMBIA. THE FIRST WILL MOVE INTO THE GREAT BASIN TONIGHT WHILE THE SECOND TAKES A MORE WESTERLY TRAJECTORY THROUGH OREGON INTO NORTHERN CALIFORNIA THURSDAY. MEANWHILE, MID-LEVEL RIDGING WILL DEVELOP ALONG THE BRITISH COLUMBIA COAST. THIS WILL ALLOW THE SECOND SHORTWAVE TO MOVE WESTWARD DEVELOPING INTO A CLOSED LOW AS IT MOVES OFFSHORE IN THE BROAD EASTERLY FLOW ALOFT THURSDAY NIGHT INTO FRIDAY. A STRONG WEST-EAST SURFACE PRESSURE GRADIENT WILL RESULT THURSDAY NIGHT INTO FRIDAY AND THIS WILL ALLOW FOR GOOD MID SLOPE AND RIDGE WINDS IN THE 15-25 MPH RANGE WITH GUSTS TO 35 MPH. COULD SEE SOME GUSTS TO 40 MPH IN CHANNELED AREAS. IT HAS BEEN EXCEPTIONALLY DRY SINCE OCTOBER AND THIS HAS RESULTED IN VERY DRY FUELS FOR THIS TIME OF YEAR. THESE WINDS, COMBINED WITH RH RECOVERIES ONLY IN THE 20-30 PERCENT RANGE COULD RESULT IN FIRE WEATHER CONCERNS. A FIRE WEATHER WATCH (RFWMFR) DETAILS THIS POTENTIAL HAZARD. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST THURSDAY FOR ORZ029>031. FIRE WEATHER WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR ORZ615>617-619>624. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ023-024-026. DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ021-023-024-026. CA...FIRE WEATHER WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR CAZ280>282-284. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 1 AM PST THURSDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST FRIDAY FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 9 PM PST THURSDAY FOR PZZ370-376. $$ MAS/TRW/FJB/SK  FXUS66 KMFR 221652 AFDMFR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 852 AM PST WED JAN 22 2014 .SHORT TERM...THE HIGH PRESSURE RIDGE JUST OFF THE COAST WILL STRENGTHEN TODAY WHILE A SHORTWAVE MOVES DOWN THE EAST SIDE OF THE RIDGE INTO EASTERN OREGON AND IDAHO. THEN ON THURSDAY THE STRONG RIDGE PERSISTS TO THE NORTH WITH AN UPPER LOW SETTING UP TO THE SOUTH OVER NORTHERN CALIFORNIA. THIS PATTERN IS EXPECTED TO BRING CONTINUED DRY WEATHER WITH STRONG OFFSHORE FLOW DEVELOPING OVER THE RIDGES TONIGHT INTO THURSDAY AND FRIDAY. IN THE VALLEYS EXPECT A DECREASE IN FOG BY THURSDAY NIGHT, EXCEPT POSSIBLY IN THE ROSEBURG AND GRANTS PASS AREAS. ON THE RIDGES, THE MAIN CONCERN WILL BE WITH THE STRONG GUSTY WINDS AND DRY AIR. UPDATED THE CURRENT FORECAST FOR TODAY OF FOG AND SKY COVER BASED ON THE LATEST SATELLITE DATA. && .AVIATION...BASED ON THE 22/12Z TAF CYCLE. FOG IS PRESENT THROUGH MANY OF THE VALLEYS IN SW OREGON AND WILL AFFECT KRBG AND KMFR WITH IFR TO LIFR VIS AND CIGS THIS MORNING. THIS FOG AND STRATUS SHOULD BURN OFF TO AT LEAST MVFR IN ALL AREAS LATE THIS MORNING WITH CLEARING TO VFR IN THE AFTERNOON. ELSEWHERE, VFR CONDITIONS WILL CONTINUE THROUGH THURSDAY. && .MARINE...LONG PERIOD MODERATE WEST SWELL WILL SUBSIDE THIS AFTERNOON AND BUILD AGAIN LATE THURSDAY. WINDS WILL INCREASE THIS AFTERNOON AND BECOME GUSTY WITH THE HIGHEST WIND SPEEDS IN THE SOUTHERN OUTER ZONE. HIGH PRESSURE LATE IN THE WEEK AND INTO THE WEEKEND WINDS WILL ALLOW WINDS TO BECOME LIGHT SOUTHERLY. && .PREV DISCUSSION... /ISSUED 345 AM PST WED JAN 22 2014/ DISCUSSION...MODIS-VIIRS NIGHTTIME MICROPHYSICS RGB SATELLITE IMAGERY VIA NASA/SPORT REVEALS PRETTY MUCH THE STATUS QUO THIS MORNING. COMPARED TO YESTERDAY'S SATELLITE IMAGE AT ABOUT THE SAME TIME, IT APPEARS NEARLY IDENTICAL WITH RESPECT TO WHERE THE LOW CLOUDS AND FOG ARE...JUST PERHAPS A SLIGHTLY SHALLOWER FOG IN PORTIONS OF THE ROGUE VALLEY. DENSE FOG ADVISORIES (NPWMFR) ARE UP FOR THE UMPQUA/ROGUE VALLEYS UNTIL 10 AM THIS MORNING. COULD ALSO BE SOME SLIPPERY SPOTS ON AREA ROADS WHERE TEMPERATURES HAVE FALLEN BELOW FREEZING. MOST AREAS BROKE OUT YESTERDAY WITH THE EXCEPTION OF GRANTS PASS. EXPECT A SIMILAR SCENARIO TODAY. AS A RESULT, HAVE NUDGED MAX TEMPS HIGHER IN MEDFORD...UP INTO THE LOW 50S...WHILE KEEPING GRANTS PASS DOWN CLOSER TO THE MID 40S. AN UPPER LEVEL SHORT WAVE WILL DIVE SOUTHEASTWARD INTO THE GREAT BASIN TODAY BRINGING SLIGHT COOLING ALOFT TO AREAS EAST OF THE CASCADES. THOSE AREAS SHOULD HAVE MAX TEMPS A FEW DEGREES LOWER THAN YESTERDAY. OFFSHORE FLOW WILL COMMENCE LATER TODAY AND TONIGHT AS THIS SYSTEM MOVES INTO UTAH AND SURFACE HIGH PRESSURE BUILDS TO THE NORTH. ANOTHER FAST-MOVING SHORT WAVE WILL DIVE SOUTHWARD THROUGH OREGON INTO NORTHERN CALIFORNIA TONIGHT INTO THURSDAY. A STRONG RIDGE WILL DEVELOP OFF THE BRITISH COLUMBIA COAST AND THIS WILL ALLOW THE SHORT WAVE TO DEVELOP INTO A CLOSED LOW AS IT MOVES WESTWARD OFFSHORE IN THE EASTERLY FLOW ALOFT. THIS SYSTEM HAS VIRTUALLY NO MOISTURE WITH IT, SO WE'RE NOT EXPECTING ANY PRECIPITATION. STRONG OFFSHORE FLOW DEVELOPS THURSDAY AND PEAKS THURSDAY NIGHT INTO FRIDAY AS A STRONG WEST-EAST SURFACE PRESSURE GRADIENT SETS UP. THIS WILL CAUSE GUSTY WINDS OVER THE EAST SIDE AND OVER THE MID SLOPES AND RIDGES FROM THE CASCADES WEST. DUE TO THE INCREASE IN WINDS AND EXPECTED MIXING, HAVE DECIDED TO END THE AIR STAGNATION ADVISORY EAST OF THE CASCADES A BIT SOONER...THURSDAY MORNING. OVER THE WEST SIDE VALLEYS, CONFIDENCE IS NOT HIGH IN WINDS REACHING THE SURFACE TO MIX OUT THE INVERSION, SO HAVE CONTINUED THE AIR STAGNATION ADVISORY THERE THROUGH EARLY SATURDAY. IT MAY NEED TO BE EXTENDED OR RE- ISSUED AS THE RIDGE ALOFT BUILDS OVERHEAD AGAIN THIS WEEKEND AND OFFSHORE FLOW EASES. THE RIDGE WILL HOLD THROUGH AT LEAST MONDAY, THEN A PACIFIC SYSTEM WILL ATTEMPT TO MOVE ONSHORE MONDAY NIGHT INTO TUESDAY. MODELS CONTINUE TO WAVER ON THE STRENGTH OF THIS SYSTEM, BUT RIGHT NOW MODELS APPEAR WEAK. HAVE MAINTAINED THE GOING FORECAST OF SLIGHT CHANCE TO CHANCE POPS...HIGHEST ON THE COAST. SPILDE FIRE WEATHER...A SIGNIFICANT OFFSHORE FLOW EVENT IS EXPECTED TO COMMENCE TODAY INCREASING TONIGHT INTO THURSDAY MORNING, THEN PEAKING THURSDAY INTO FRIDAY MORNING. THIS IS IN RESPONSE TO TWO STRONG SHORT WAVE DISTURBANCES TRACKING SOUTHWARD FROM BRITISH COLUMBIA. THE FIRST WILL MOVE INTO THE GREAT BASIN TONIGHT WHILE THE SECOND TAKES A MORE WESTERLY TRAJECTORY THROUGH OREGON INTO NORTHERN CALIFORNIA THURSDAY. MEANWHILE, MID-LEVEL RIDGING WILL DEVELOP ALONG THE BRITISH COLUMBIA COAST. THIS WILL ALLOW THE SECOND SHORTWAVE TO MOVE WESTWARD DEVELOPING INTO A CLOSED LOW AS IT MOVES OFFSHORE IN THE BROAD EASTERLY FLOW ALOFT THURSDAY NIGHT INTO FRIDAY. A STRONG WEST-EAST SURFACE PRESSURE GRADIENT WILL RESULT THURSDAY NIGHT INTO FRIDAY AND THIS WILL ALLOW FOR GOOD MID SLOPE AND RIDGE WINDS IN THE 15-25 MPH RANGE WITH GUSTS TO 35 MPH. COULD SEE SOME GUSTS TO 40 MPH IN CHANNELED AREAS. IT HAS BEEN EXCEPTIONALLY DRY SINCE OCTOBER AND THIS HAS RESULTED IN VERY DRY FUELS FOR THIS TIME OF YEAR. THESE WINDS, COMBINED WITH RH RECOVERIES ONLY IN THE 20-30 PERCENT RANGE COULD RESULT IN FIRE WEATHER CONCERNS. A FIRE WEATHER WATCH (RFWMFR) DETAILS THIS POTENTIAL HAZARD. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...AIR STAGNATION ADVISORY UNTIL 10 AM PST THURSDAY FOR ORZ029>031. FIRE WEATHER WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR ORZ615>617-619>624. AIR STAGNATION ADVISORY UNTIL 4 AM PST SATURDAY FOR ORZ023-024-026. DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ021-023-024-026. CA...FIRE WEATHER WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR CAZ280>282-284. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 4 PM THIS AFTERNOON TO 1 AM PST THURSDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 1 AM PST THURSDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR WINDS FROM 4 PM THIS AFTERNOON TO 4 PM PST THURSDAY FOR PZZ370. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST FRIDAY FOR PZZ370-376. SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM THIS AFTERNOON TO 4 PM PST THURSDAY FOR PZZ376. $$ CC  FXUS66 KMFR 211141 AAA AFDMFR AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MEDFORD OR 441 AM PDT FRI MAR 21 2014 UPDATED AVIATION AND MARINE SECTIONS .DISCUSSION...AT THE SURFACE A THERMAL TROUGH IS LOCATED ALONG THE NORTHERN CALIFORNIA AND SOUTHERN OREGON COAST WITH HIGH PRESSURE OFFSHORE. THIS IS BRINGING VERY GUSTY WINDS TO THE COASTAL MOUNTAINS AND TO THE COASTAL WATERS THIS MORNING...WITH THE GUSTY WINDS EXPECTED TO CONTINUE OVER THE COASTAL WATERS AND ALONG THE COAST THROUGH THIS EVENING. MEANWHILE, ALOFT NORTHWEST FLOW IS BRINGING A COUPLE WEAK SHORTWAVES INTO THE AREA TODAY BUT EXPECT CONTINUED DRY CONDITIONS. THEN ON THE WEEKEND , A HIGH PRESSURE RIDGE WILL BUILD OVER THE REGION BRINGING WARMER TEMPERATURES AS WELL AS CONTINUED DRY CONDITIONS. ON MONDAY THE RIDGE IS FORECAST TO SHIFT EAST WITH A FRONTAL SYSTEM APPROACHING THE COAST MONDAY EVENING AND NIGHT. THIS WILL BRING A CHANGE TO A WETTER AND COOLER REGIME. THIS MORNING SOME HIGH CLOUDS ARE PRESENT OVER THE AREA. ALSO LIGHT WINDS HAVE CONTINUED IN MANY INLAND VALLEY LOCATIONS. AS A RESULT TEMPERATURES HAVE BEEN SLOW TO DROP TONIGHT. STILL EXPECT AREAS OF FREEZING AND BELOW FREEZING TEMPERATURES IN WEST SIDE VALLEYS, ESPECIALLY IN OUTLYING AREAS OF THE ROGUE VALLEY, THE APPLEGATE AND ILLINOIS VALLEYS AND INTO THE SHASTA VALLEY. GIVEN DEW POINTS IN THESE AREAS RANGING FROM 22 TO 30 DEGREES F EARLY THIS MORNING, EXPECT LOCATIONS THAT ARE PROTECTED FROM WIND TO DROP INTO THE UPPER 20S. A WEAK SHORTWAVE TROUGH TO THE NORTHWEST WILL MOVE INTO THE AREA TODAY AND THEN SHIFT EASTWARD THIS EVENING. THE GFS AND ECMWF MODELS CONTINUE TO SHOW SOME LIGHT ISOLATED PRECIPITATION OVER MODOC COUNTY AND OVER AREAS FURTHER SOUTH THIS AFTERNOON AND EVENING WHILE THE NAM AND RUC KEEP THE AREA DRY. GIVEN THE LACK OF GOOD MOISTURE EXPECT MAINLY JUST SOME CLOUD COVER WITH NO PRECIPITATION. OTHERWISE, ACROSS THE AREA EXPECT MILD TEMPERATURES AND MOSTLY SUNNY SKIES TODAY. GUSTY WINDS ARE EXPECTED ALONG THE COAST THIS MORNING, INCREASING THIS AFTERNOON AND CONTINUING INTO THE EVENING. THE WINDS ALONG THE COAST AND OVER THE COASTAL WATERS WILL WEAKEN SOME TONIGHT INTO SATURDAY. STILL EXPECT GUSTY WINDS TO CONTINUE ON SATURDAY FOR SOME COASTAL AREAS AND FOR THE COASTAL WATERS, ESPECIALLY SOUTH OF CAPE BLANCO. THEN ON SUNDAY AS THE UPPER RIDGE AXIS MOVES INLAND OVER THE REGION, THE THERMAL TROUGH WILL SHIFT INLAND AND WINDS ALONG THE COAST WILL WEAKEN. MEANWHILE INLAND LOCATIONS WILL SEE A WARMING TREND AS THE RIDGE BUILDS INTO THE AREA THIS WEEKEND. THESE WARM TEMPERATURES WILL CONTINUE FOR INLAND ON MONDAY. THEN MODELS ARE SHOWING GOOD AGREEMENT WITH A MOIST AND COOL PATTERN DEVELOPING MONDAY NIGHT AND TUESDAY AS AN UPPER LOW SETS UP IN THE GULF OF ALASKA. THIS IS EXPECTED TO BRING A SERIES OF FRONTS INTO THE AREA NEXT WEEK. THE FIRST OF THESE IS A MOIST FRONTAL SYSTEM WHICH MODELS SHOW APPROACHING THE COAST MONDAY EVENING AND MOVING INLAND MONDAY NIGHT AND TUESDAY. HAVE RAISED POPS DURING THIS PERIOD. SNOW LEVELS ARE EXPECTED TO REMAIN HIGH, MAINLY ABOVE 7000 FEET, AHEAD OF THE FRONT AND THEN LOWER BEHIND THE FRONT TUESDAY AND TUESDAY NIGHT TO AROUND 5000 FEET. /CC && .AVIATION...BASED ON THE 21/12Z TAF CYCLE. LOW CLOUDS DEVELOPED IN THE UMPQUA VALLEY IN THE LAST HOUR OR SO. THIS WILL BRING MVFR TO KRBG FOR AT LEAST A FEW HOURS THIS MORNING BEFORE BURNING OFF BY AROUND 17Z. PATCHY IFR FOG IS ALSO EVIDENT IN THE MODIS-VIIRS NIGHTTIME MICROPHYSICS RGB IMAGERY THIS MORNING OVER PORTIONS OF THE COQUILLE VALLEY AND THE LOWER UMPQUA BASIN NEAR REEDSPORT. THE REMAINDER OF THE AREA WILL BE VFR FOR THE NEXT 24 HOURS, THOUGH GUSTY NORTH WINDS TO AROUND 30KT WILL DEVELOP THIS AFTERNOON ALONG THE COAST NEAR KOTH. SPILDE && .MARINE...NORTH GALES WILL CONTINUE OVER THE OUTER WATERS SOUTH OF CAPE BLANCO TODAY AS A THERMAL TROUGH PERSISTS OVER NORTHERN CALIFORNIA. GALES WILL NUDGE INTO THE SOUTHERN INNER ZONE AGAIN THIS AFTERNOON AND CONTINUE INTO THIS EVENING. THIS WILL BRING STEEP TO VERY STEEP WIND DRIVEN SEAS, ESPECIALLY BETWEEN 5 AND 40 NM OFFSHORE. HAZARDOUS CONDITIONS TO SMALL CRAFT WILL EXIST OVER THE ENTIRE WATERS. THE THERMAL TROUGH WILL WEAKEN TONIGHT, SO WINDS AND SEAS SHOULD EASE SOMEWHAT INTO SATURDAY. OFFSHORE HIGH PRESSURE WILL PERSIST THROUGH THE WEEKEND. A WETTER AND WINDIER PATTERN WITH MOSTLY SOUTHERLY WINDS WILL DEVELOP MONDAY NIGHT WHEN THE FIRST OF SEVERAL FRONTS MOVES THROUGH THE WATERS. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR ORZ024-026. FREEZE WARNING UNTIL 9 AM PDT THIS MORNING FOR ORZ024-026. CA...FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR CAZ081. FREEZE WARNING UNTIL 9 AM PDT THIS MORNING FOR CAZ081. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT SATURDAY FOR PZZ350-356. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT SATURDAY FOR PZZ350-356. GALE WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THIS EVENING FOR PZZ356. HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ350-356-370. SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT SATURDAY FOR PZZ370-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING TO 11 PM PDT SATURDAY FOR PZZ370-376. GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. HAZARDOUS SEAS WARNING UNTIL 5 AM PDT SATURDAY FOR PZZ376. $$ MAS/CC  FXUS66 KMFR 211149 AFDMFR Area Forecast Discussion National Weather Service Medford OR 449 AM PDT SUN AUG 21 2016 Updated AVIATION Section .DISCUSSION...Yesterday was another one for the record books as Medford, Roseburg, Klamath Falls, and Montague all set daily high temperature records for the third straight day. Temperatures will continue their downward trend today (but will still be 5-8 degrees above normal) and then even moreso tomorrow with temperatures back down around normal. This is all in response to lower heights as a trough moves along the U.S./Canadian border and an increase in onshore flow. Speaking of winds, the gradients will be fairly tight both today and tomorrow, so gusty afternoon west-northwest winds can be expected. Humidities remain low, especially east of the Cascades. This raises fire danger, and a variety of fire weather headlines are in effect to cover this. See PDXRFWMFR and/or the fire discussion below for details. There will be some weak instability over Siskiyou and Modoc counties today and tomorrow, but both moisture and forcing are lacking, so I wouldn't expect anything more than afternoon buildups. The models remain in decent agreement for the remainder of the week and show an upper ridge gradually building offshore and a trough over the middle of the country, which leaves us in the benign north flow between the two. The surface thermal trough will gradually reassert itself along the coast, which allows us to warm again, but relatively lower heights should prevent a repeat of our recent heat wave. The models then begin to differ for next weekend, but the preponderance of guidance suggests lowering heights over us as another trough comes down the B.C. coast. Models vary in strength and how far south the trough moves, but all suggest a dip in temperatures back toward normal with little to no chance for precipitation. -Wright && .AVIATION...21/12Z TAF cycle...NASA SPoRT VIIRS Nighttime Microphyics RGB satellite imagery is showing IFR/LIFR stratus/fog over all of the coastal waters early this morning, extending inland about 20-30 miles north of Cape Blanco, but hugging the immediate coastline south of Cape Blanco. Expect IFR to yield to VFR late this morning or early this afternoon (around 20-21Z), but IFR will return to the coast this evening. VFR will prevail elsewhere for the next 24 hours. Spilde && .MARINE...Updated 245 AM PDT, Sunday 21 August 2016...The gradient between high pressure offshore and a thermal trough inland will tighten today into Monday. This will result in increasing northerly winds. Winds about 5 to 30 NM offshore from around Cape Blanco to Gold Beach will reach low end small craft advisory criteria this afternoon and evening. The thermal trough is expected to reach a peak of strength on Monday afternoon with advisory conditions developing over much of the waters. North winds will be weakest north of Cape Arago and also near shore south of Brookings. Winds will be strongest in the outer waters south of Cape Blanco with high end small craft or low end gale force winds. A modest weakening will follow with wind dominated seas continuing through the middle of the week. Spilde && .FIRE WEATHER...Updated 250 AM PDT Sunday 21 August 2016... An upper level low will move across southern British Columbia and into southern Alberta today into Monday. This will allow an upper trough to swing through the area during this time frame. As a result, we'll see an uptick in west to northwest winds across the area. We won't be as blasted hot as we were the last few days, but afternoon humidities will still be near critical levels once again. Due to the combination of strong, gusty winds and humidities near critical levels (generally down to 10-15%, but even some single digit readings here and there) we've got myriad headlines out for the region. See the red flag warning message at PDXRFWMFR for the details. Haines 6 conditions are expected near the Withers Fire again this afternoon and evening, which is conducive for plume dominated fire. Humidities increase ever so slightly on Monday, but we'll still see some pretty gusty winds and fire weather watches remain up for portions of the east side. By Tuesday and Wednesday, winds should dial back a bit, though it will remain dry as a bone with mid slope and ridge recoveries in the poor to moderate range. Really, there is no significant rainfall in sight. Perhaps the silver lining to the dryness is that we have managed to avoid large lightning busts so far this summer. Still nothing on the horizon through the end of August lightning-wise. Spilde && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Red Flag Warning from noon today to 9 PM PDT this evening for ORZ624-625. Fire Weather Watch from Monday afternoon through Monday evening for ORZ624-625. Red Flag Warning from 2 PM this afternoon to 8 PM PDT this evening for ORZ622. CA...Red Flag Warning from noon today to 9 PM PDT this evening for CAZ285. Red Flag Warning from 1 PM this afternoon to 9 PM PDT this evening for CAZ280. Pacific Coastal Waters...Small Craft Advisory from 11 AM Monday to 5 AM PDT Tuesday for PZZ350-370. Small Craft Advisory from 11 AM this morning to 5 AM PDT Tuesday for PZZ356-376. $$  FXUS66 KMFR 211539 AFDMFR Area Forecast Discussion National Weather Service Medford OR 839 AM PDT SUN AUG 21 2016 .DISCUSSION...Previous forecast is on track and no changes are needed. Skies are clear over most of the region. Marine stratus is along the coast, Coquille Basin and northwest Douglas County and this should erode during the morning with clear skies in the afternoon. However the stratus probably will hug along the coast into the afternoon. See previous discussion for details. -Petrucelli && .AVIATION...21/12Z TAF cycle...NASA SPoRT VIIRS Nighttime Microphyics RGB satellite imagery is showing IFR/LIFR stratus/fog over all of the coastal waters early this morning, extending inland about 20-30 miles north of Cape Blanco, but hugging the immediate coastline south of Cape Blanco. Expect IFR to yield to VFR late this morning or early this afternoon (around 20-21Z), but IFR will return to the coast this evening. VFR will prevail elsewhere for the next 24 hours. Spilde && .MARINE...Updated 245 AM PDT, Sunday 21 August 2016...The gradient between high pressure offshore and a thermal trough inland will tighten today into Monday. This will result in increasing northerly winds. Winds about 5 to 30 NM offshore from around Cape Blanco to Gold Beach will reach low end small craft advisory criteria this afternoon and evening. The thermal trough is expected to reach a peak of strength on Monday afternoon with advisory conditions developing over much of the waters. North winds will be weakest north of Cape Arago and also near shore south of Brookings. Winds will be strongest in the outer waters south of Cape Blanco with high end small craft or low end gale force winds. A modest weakening will follow with wind dominated seas continuing through the middle of the week. Spilde && .FIRE WEATHER...Updated 250 AM PDT Sunday 21 August 2016... An upper level low will move across southern British Columbia and into southern Alberta today into Monday. This will allow an upper trough to swing through the area during this time frame. As a result, we'll see an uptick in west to northwest winds across the area. We won't be as blasted hot as we were the last few days, but afternoon humidities will still be near critical levels once again. Due to the combination of strong, gusty winds and humidities near critical levels (generally down to 10-15%, but even some single digit readings here and there) we've got myriad headlines out for the region. See the red flag warning message at PDXRFWMFR for the details. Haines 6 conditions are expected near the Withers Fire again this afternoon and evening, which is conducive for plume dominated fire. Humidities increase ever so slightly on Monday, but we'll still see some pretty gusty winds and fire weather watches remain up for portions of the east side. By Tuesday and Wednesday, winds should dial back a bit, though it will remain dry as a bone with mid slope and ridge recoveries in the poor to moderate range. Really, there is no significant rainfall in sight. Perhaps the silver lining to the dryness is that we have managed to avoid large lightning busts so far this summer. Still nothing on the horizon through the end of August lightning-wise. Spilde && .PREV DISCUSSION... /Issued 449 AM PDT SUN AUG 21 2016/ DISCUSSION...Yesterday was another one for the record books as Medford, Roseburg, Klamath Falls, and Montague all set daily high temperature records for the third straight day. Temperatures will continue their downward trend today (but will still be 5-8 degrees above normal) and then even moreso tomorrow with temperatures back down around normal. This is all in response to lower heights as a trough moves along the U.S./Canadian border and an increase in onshore flow. Speaking of winds, the gradients will be fairly tight both today and tomorrow, so gusty afternoon west-northwest winds can be expected. Humidities remain low, especially east of the Cascades. This raises fire danger, and a variety of fire weather headlines are in effect to cover this. See PDXRFWMFR and/or the fire discussion below for details. There will be some weak instability over Siskiyou and Modoc counties today and tomorrow, but both moisture and forcing are lacking, so I wouldn't expect anything more than afternoon buildups. The models remain in decent agreement for the remainder of the week and show an upper ridge gradually building offshore and a trough over the middle of the country, which leaves us in the benign north flow between the two. The surface thermal trough will gradually reassert itself along the coast, which allows us to warm again, but relatively lower heights should prevent a repeat of our recent heat wave. The models then begin to differ for next weekend, but the preponderance of guidance suggests lowering heights over us as another trough comes down the B.C. coast. Models vary in strength and how far south the trough moves, but all suggest a dip in temperatures back toward normal with little to no chance for precipitation. -Wright AVIATION...21/12Z TAF cycle...NASA SPoRT VIIRS Nighttime Microphyics RGB satellite imagery is showing IFR/LIFR stratus/fog over all of the coastal waters early this morning, extending inland about 20-30 miles north of Cape Blanco, but hugging the immediate coastline south of Cape Blanco. Expect IFR to yield to VFR late this morning or early this afternoon (around 20-21Z), but IFR will return to the coast this evening. VFR will prevail elsewhere for the next 24 hours. Spilde MARINE...Updated 245 AM PDT, Sunday 21 August 2016...The gradient between high pressure offshore and a thermal trough inland will tighten today into Monday. This will result in increasing northerly winds. Winds about 5 to 30 NM offshore from around Cape Blanco to Gold Beach will reach low end small craft advisory criteria this afternoon and evening. The thermal trough is expected to reach a peak of strength on Monday afternoon with advisory conditions developing over much of the waters. North winds will be weakest north of Cape Arago and also near shore south of Brookings. Winds will be strongest in the outer waters south of Cape Blanco with high end small craft or low end gale force winds. A modest weakening will follow with wind dominated seas continuing through the middle of the week. Spilde FIRE WEATHER...Updated 250 AM PDT Sunday 21 August 2016... An upper level low will move across southern British Columbia and into southern Alberta today into Monday. This will allow an upper trough to swing through the area during this time frame. As a result, we'll see an uptick in west to northwest winds across the area. We won't be as blasted hot as we were the last few days, but afternoon humidities will still be near critical levels once again. Due to the combination of strong, gusty winds and humidities near critical levels (generally down to 10-15%, but even some single digit readings here and there) we've got myriad headlines out for the region. See the red flag warning message at PDXRFWMFR for the details. Haines 6 conditions are expected near the Withers Fire again this afternoon and evening, which is conducive for plume dominated fire. Humidities increase ever so slightly on Monday, but we'll still see some pretty gusty winds and fire weather watches remain up for portions of the east side. By Tuesday and Wednesday, winds should dial back a bit, though it will remain dry as a bone with mid slope and ridge recoveries in the poor to moderate range. Really, there is no significant rainfall in sight. Perhaps the silver lining to the dryness is that we have managed to avoid large lightning busts so far this summer. Still nothing on the horizon through the end of August lightning-wise. Spilde && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Red Flag Warning from noon today to 9 PM PDT this evening for ORZ624-625. Fire Weather Watch from Monday afternoon through Monday evening for ORZ624-625. Red Flag Warning from 2 PM this afternoon to 8 PM PDT this evening for ORZ622. CA...Red Flag Warning from noon today to 9 PM PDT this evening for CAZ285. Red Flag Warning from 1 PM this afternoon to 9 PM PDT this evening for CAZ280. Pacific Coastal Waters...Small Craft Advisory from 11 AM Monday to 5 AM PDT Tuesday for PZZ350-370. Small Craft Advisory until 5 AM PDT Tuesday for PZZ356-376. $$ MAP/MAP/MAP  FXUS66 KMFR 111156 AFDMFR Area Forecast Discussion National Weather Service Medford OR 356 AM PST Mon Dec 11 2017 .DISCUSSION...A strong ridge over the Intermountain West will continue to be the main feature dominating our weather much of this week. Taking a look at the latest pass from the polar orbiting satellite, Suomi NPP, the NASA SPoRT nighttime microphysics imagery via the VIIRS instrument is showing areas of low clouds/fog in the Umpqua Basin from about Scottsburg to Elkton and Drain south along Interstate 5 to around 227 Canyonville. We currently have a dense fog advisory in effect for those areas. More fog/stratus can be seen in the Rogue/Illinois Valleys, and indeed, fog has developed here at the airport in the last hour. A freezing fog advisory is in effect in these locations. Specific advisory details can be viewed at NPWMFR. Patchy fog is also showing up in the lower Klamath River Valley as well as the Scott Valley and in the Christmas Valley over northern Lake County. 24 hours ago, the imagery was virtually the same, and with little change in the atmospheric profile, a persistence forecast will once again be favored over any single piece of guidance with respect to sky/temperatures today. An offshore front will make its way toward the coastal waters late today and tonight, but will dissipate Tuesday as it runs into the strong ridge. The ridge will re-establish along the West Coast Tuesday through Thursday resulting in more of the status quo - morning fog/stratus in the valleys west of the Cascades that will have difficulty breaking in some areas during the afternoons. Overall, it will remain cool/chilly in the valleys with milder conditions along the coast and at elevations just above the valley floors. -Spilde .LONG TERM...Thursday night until next Tuesday...No changes. A short wave trough will break through the ridge Friday. This trough will bring a little bit of rain and perhaps some freezing rain east of the Cascades Friday morning. The freezing rain should be very light looking at the model QPF output and the soundings east of the Cascades. After this quick hitting system moves through Friday, a deep trough will setup in the Gulf of Alaska. In general, models are in pretty good agreement with what will happen as an atmospheric river type event will impact the region. This should result in wetting precipitation for the majority of next weekend. The only reason for a little lack of confidence is how models are still changing run to run with exact timing and location. Right now the forecast calls for snow levels around 4000-6500 feet on Saturday before the snow levels rise on Sunday. The bulk of the precipitation will arrive when snow levels are higher, so not willing to commit to say that the mountains will see enough snow to make a difference in the snow pack. After Sunday night, it appears some more precipitation will be on the way during the Tuesday and Wednesday time frame. It's still unclear how strong that upcoming system might be or if it will miss the Oregon area entirely. -Smith && .AVIATION...11/12Z TAF CYCLE...IFR/LIFR conditions will continue this morning for RBG and MFR TAF sites. This is essentially a persistent forecast as the inversion has strengthened even more tonight. IFR/LIFR conditions will continue until the early afternoon hours on Monday for the Umpqua Valley and should lift around the noon hour in the Rogue Valley. VFR conditions will prevail elsewhere, including the coast and coastal waters. -Sven && .MARINE...Updated 230 AM PST Monday, Dec 11th, 2017...High pressure will remain in control over the waters with conditions remaining below small craft advisory levels through mid week. A dissipating cold front is expected to brush the outer portions of the coastal waters area late Monday, at which time west swell will increase through Tuesday afternoon. North winds will increase Wednesday as high pressure rebuilds, but will likely remain below small craft advisory levels. A change to a more active weather pattern is expected this weekend with increased swell and periods of increased southerly winds. -Sven && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Air Stagnation Advisory until 2 PM PST Thursday for ORZ023-024-026-029>031. Dense Fog Advisory until 10 AM PST this morning for ORZ023. Freezing Fog Advisory until 10 AM PST this morning for ORZ024-026. CA...None. Pacific Coastal Waters...None. $$ MAS/SBN/CZS