FXUS62 KTAE 250851 AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 351 AM EST TUE JAN 25 2011 ...SLIGHT RISK OF SEVERE STORMS FOR THE SOUTHEAST BIG BEND THIS AFTERNOON... .SYNOPSIS... AN AREA OF LOW PRESSURE DEVELOPING IN THE GULF OF MEXICO WILL MOVE EASTWARD TODAY THROUGH THE AREA...PROVIDING RAIN AND A CHANCE OF THUNDERSTORMS. THE BEST CHANCE OF THUNDERSTORMS IS STILL EXPECTED TO BE NEAR AND SOUTHEAST OF A LINE FROM MEXICO BEACH TO TALLAHASSEE TO VALDOSTA WITH A SLIGHT RISK OF SEVERE STORMS OVER THE SOUTHEAST BIG BEND. TWO POTENTIAL SCENARIOS FOR THE POSSIBLE EVOLUTION OF THE CONVECTION ARE DISCUSSED BELOW. TOTAL RAINFALL AMOUNTS ARE EXPECTED TO AVERAGE BETWEEN 1 AND 2 INCHES. DRY WX IS EXPECTED TO RETURN FOR WEDNESDAY AND THURSDAY. && .SHORT TERM... (TODAY THROUGH THURSDAY) THE MAIN FOCUS FOR THE SHORT TERM IS ON TODAY AND TONIGHT AS AN AREA OF LOW PRESSURE MOVES THROUGH THE REGION. ALTHOUGH BOTH THE NAM AND GFS HAVE COME TO A CONSENSUS ON THE MAIN LOW TRACKING OVER THE WESTERN PART OF THE FORECAST AREA...SOME INTERESTING THINGS WILL HAPPEN SOUTH OF THE AREA IN THE GULF OF MEXICO TODAY THAT COULD INFLUENCE THE FORECAST LOCALLY. LOOKING AT THE BIG PICTURE...A SUBTLE BUT PERHAPS IMPORTANT ~100 KNOT SUBTROPICAL JET STREAK AT 250 MB IS FORECAST TO SWEEP ACROSS CENTRAL MEXICO. BY THE AFTERNOON HOURS TODAY...THE LEFT EXIT REGION OF THIS JET AND THE RIGHT ENTRANCE REGION OF THE MID-LATITUDE JET WILL BE ALIGNED IN A VERY FAVORABLE POSITION FOR RISING MOTION OVER THE CENTRAL GULF OF MEXICO. IN ADDITION...THIS WILL BE HAPPENING NEAR AND OVER A WARM EDDY IN THE LOOP CURRENT WHERE MORE FAVORABLE THERMODYNAMICS EXIST. THE END RESULT WILL LIKELY BE VERY ROBUST THUNDERSTORM DEVELOPMENT OVER THE CENTRAL GULF OF MEXICO IN THE FORM OF A SQUALL LINE AT SOME POINT THIS AFTERNOON THAT WILL MOVE RAPIDLY EASTWARD THIS EVENING. THESE VERY INTENSE THUNDERSTORMS SHOULD STAY SOUTH OF THE AREA...BUT THEY MAY ACT TO LOWER PRESSURES AND DEVELOP A MESO-LOW IN ASSOCIATION WITH THE SQUALL LINE THAT MAY DISRUPT OUR LOCAL MOISTURE INFLUX TO SOME EXTENT. IN THIS FIRST SCENARIO...THE END RESULT WOULD BE SLIGHTLY LOWER RAINFALL AMOUNTS AND A REDUCED CHANCE OF STRONGER STORMS LOCALLY SINCE ALL OF THE THERMODYNAMICS AND DYNAMICS ASSOCIATED WITH THE SQUALL LINE WOULD BE SOUTH OF THE AREA. HOWEVER...IF THAT DEVELOPMENT IS DELAYED SLIGHTLY...THEN FAVORABLE LIFT WITH THE RIGHT ENTRANCE REGION OF THE MID-LATITUDE JET LOCALLY COUPLED WITH THE APPROACH OF THE UPPER LEVEL AND SURFACE LOW COULD ALLOW STORMS TO DEVELOP FURTHER NORTHWARD INITIALLY. IN FACT...OUR LOCAL 4 KM WRF IS SHOWING A RATHER IMPRESSIVE LOOKING QLCS SQUALL LINE CROSSING THE FORECAST AREA DURING THE AFTERNOON AND EVENING HOURS TODAY. THE LIMITING FACTOR IN THIS SCENARIO WOULD BE LACK OF SURFACE BASED INSTABILITY WITH FLOW OFF THE COOL SHELF WATERS OF APALACHEE BAY. THE LOCAL WRF...WHICH ASSIMILATES THE HIGH RESOLUTION MODIS SST DATA...DOES NOT SHOW ANY SURFACE BASED INSTABILITY IN THE FORECAST AREA...WITH ONE NOTABLE EXCEPTION OVER THE SOUTHEAST BIG BEND. IN THE SOUTHEAST BIG BEND REGION...THE LOCAL HIGH RES WRF ACTUALLY MANAGES TO DEVELOP UPWARDS OF 500-800 J/KG OF SBCAPE DURING THE LATE AFTERNOON HOURS. THIS HAPPENS IN THE MODEL BECAUSE IT HAS THE SURFACE WINDS IN THAT AREA MORE SOUTHEASTERLY THAN DUE SOUTHERLY...WHICH KEEPS THE SURFACE FLOW TRAJECTORY MORE AWAY FROM APALACHEE BAY AND ALLOWS A RICHER INFLUX OF MOISTURE FROM THE FL PENINSULA. THIS IS A MUCH MORE THREATENING SCENARIO WHERE WE END UP WITH HIGHER INSTABILITY AND BACKED SURFACE WINDS THAT COULD LOCALLY ENHANCE HELICITY AHEAD OF AN APPROACHING QLCS SQUALL LINE. AS WITH MOST CONVECTIVE SITUATIONS...IT IS HARD TO SAY WHICH SCENARIO WILL HAPPEN DUE TO THE INHERENT DIFFICULTIES OF EXPLICITLY FORECASTING CONVECTION. HOWEVER...WITH AT LEAST SOME GUIDANCE SHOWING THE MORE THREATENING SCENARIO...DO NOT WANT TO DOWNPLAY THE SEVERE THREAT FOR THE SOUTHEAST BIG BEND TOO MUCH AND HAVE INCLUDED A SLIGHT CHANCE OF SEVERE WORDING IN THE GRIDS IN THE AREAS THAT SPC HAS HIGHLIGHTED UNDER A SLIGHT RISK. .LONG TERM... (THURSDAY NIGHT THROUGH NEXT TUESDAY)...AS WE HAVE BEEN ADVERTISING DURING THE LAST FEW NIGHTS...THE AIR MASS BUILDING IN BEHIND TODAY'S LOW PRESSURE SYSTEM WILL BE OF CONTINENTAL ORIGIN AND NOT ARCTIC LIKE SO MANY OF THE PRECEDING SFC RIDGES SO FAR THIS WINTER. THEREFORE...AFTER A COUPLE OF COOL DAYS IN THE SHORT TERM ON WEDNESDAY AND THURSDAY WITH ONLY LIGHT FREEZES EXPECTED FOR PARTS OF THE REGION ON THURSDAY AND FRIDAY MORNINGS...A VERY WELCOME MODERATING TREND IS NOW EXPECTED FOR THE END OF THE WEEK AND MUCH...IF NOT ALL...OF THE UPCOMING WEEKEND. WHILE LOWS WILL REMAIN ABOVE FREEZING DURING THIS PERIOD...HIGH TEMPERATURES SHOULD MODERATE FROM THE LOWER 60S ON FRIDAY...TO THE BALMY MID TO UPPER 60S ON SATURDAY AND SUNDAY. FOR MONDAY AND TUESDAY...THERE ARE SOME DISCREPANCIES BETWEEN THE 00 UTC GFS AND THE OLDER 12 UTC ECMWF... BUT MAINLY JUST IN THE POP CATEGORY...WITH THE MILD WEATHER LIKELY TO CONTINUE. THE ECMWF HAS A VERY WET SOLUTION FOR TUESDAY...WHILE THE GFS WOULD ARGUE FOR HIGHER POPS ON SUNDAY INTO MONDAY...WITH COOLER AND DRIER CONDITIONS RETURNING FOR TUESDAY. THEREFORE...WILL INTRODUCE POPS TO THE FCST FOR SUNDAY AFTERNOON...AND WILL KEEP AT LEAST LOW END POPS IN THROUGH TUESDAY UNTIL A BETTER CONSENSUS CAN BE REACHED. AS FOR THE NEXT POTENTIAL ARCTIC OUTBREAK WE HAVE BEEN KEEPING AN EYE ON...IT STILL COULD VERY WELL BE IN THE CARDS FOR NEXT THURSDAY AND FRIDAY...AS PLENTY OF ARCTIC AIR IN NW CANADA IS STILL WAITING FOR AN OPPORTUNITY TO PLUNGE SE BACK INTO THE SE U.S. && .AVIATION... IT WILL CERTAINLY BE A MUCH MORE CHALLENGING AVIATION FCST TONIGHT THAN IT WAS AT THIS SAME TIME ON MONDAY NIGHT...AS A DEVELOPING LOW PRESSURE SYSTEM WHICH IS NOW GETTING ORGANIZED JUST OFF THE SW COAST OF LA MOVES E-NE THROUGH OUR CWA TODAY. AS THIS LOW CONTINUES TO SLOWLY STRENGTHEN AND APPROACH OUR AREA FROM THE WEST...A LARGE SWATH OF RAIN IS EXPECTED TO DEVELOP WELL OUT IN ITS ADVANCE DUE TO A PERIOD OF STRONG ISENTROPIC LIFT. INITIALLY...THIS RAIN WILL LIKELY BE LIGHT TO MODERATE AT TIMES AND SHOULD FALL FROM MAINLY VFR LEVEL CIGS ESPECIALLY DURING THE OVERNIGHT AND EARLY MORNING HOURS. THEREAFTER...CONDITIONS SHOULD RAPIDLY DETERIORATE FROM WEST TO EAST DURING THE DAYLIGHT HOURS AS THE HEAVIER BANDS OF RAIN WITH A FEW EMBEDDED THUNDERSTORMS (WITH THE BEST CHANCES FOR THUNDER AT TLH AND VLD) ACCELERATE EASTWARD ACROSS THE TERMINALS. THIS IS EXPECTED TO RESULT IN AN EXTENDED PERIOD OF MVFR TO IFR CONDITIONS...WITH THE RAIN LINGERING AFTER 00 UTC WED IN MOST LOCATIONS. EVEN AFTER THE RAIN ENDS...THERE WILL LIKELY BE A PERIOD OF LOW CLOUDS AND SOME FOG AFTER THE LOW MOVES THROUGH...SO TIMING THE IMPROVING CONDITIONS ON WED. SHOULD BE QUITE CHALLENGING AS WELL. && .MARINE... AN INTENSIFYING LOW PRESSURE SYSTEM WILL MOVE NORTHEAST ACROSS THE FLORIDA PANHANDLE LATE THIS AFTERNOON THROUGH TONIGHT...BRINGING SHOWERS AND THUNDERSTORMS...INCREASING WINDS AND SEAS...AND ABOVE NORMAL TIDES TO THE MARINE AREA. ALTHOUGH THE RAIN WILL LIKELY END BY WEDNESDAY MORNING AS THE LOW MOVES INTO THE CAROLINAS...WINDS AND SEAS WILL REMAIN HIGH...LIKELY AT ADVISORY LEVELS. THE SURF HEIGHTS ARE EXPECTED TO REMAIN BELOW HIGH SURF CRITERIA AT THIS TIME. THE EXTRATROPICAL STORM SURGE GUIDANCE CONTINUES TO FORECAST TIDES 1 TO 1.5 FEET ABOVE NORMAL TONIGHT THROUGH WEDNESDAY MORNING...WHICH SHOULD HAVE LITTLE IMPACT ON COASTAL RESIDENTS. WINDS AND SEAS WILL SUBSIDE THURSDAY AS A HIGH PRESSURE RIDGE BUILDS ACROSS THE GULF COAST. && .FIRE WEATHER... WITH A DEVELOPING LOW PRESSURE SYSTEM MOVING INTO THE REGION TODAY WITH WIDESPREAD RAIN POSSIBLY LINGERING WELL INTO TUESDAY NIGHT...NO FIRE WEATHER CONCERNS ARE EXPECTED UNTIL THURSDAY OR FRIDAY. FURTHERMORE...THE NEXT AIR MASS BUILDING IN BEHIND THIS LOW WILL LIKELY ONLY BE DRY ENOUGH TO POSE A THREAT TO THE FL BIG BEND AND PANHANDLE...AS THE CRITERIA OF SUB 35 PERCENT RH OVER FL WILL BE EASIER TO REACH THAN THE MORE DIFFICULT SUB 25 PERCENT REQUIREMENT FOR OUR AL AND GA ZONES. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 63 48 56 30 56 / 100 40 10 0 0 PANAMA CITY 62 46 54 34 54 / 100 40 10 0 0 DOTHAN 51 41 52 31 54 / 100 40 10 0 0 ALBANY 50 42 51 29 54 / 100 40 10 0 0 VALDOSTA 61 50 57 34 57 / 100 60 10 0 0 CROSS CITY 68 52 62 32 58 / 100 80 10 0 0 APALACHICOLA 64 49 57 35 55 / 100 50 10 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. GM...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 7 PM EST WEDNESDAY FOR THE FOLLOWING ZONES: APALACHEE BAY OR COASTAL WATERS FROM KEATON BEACH TO OCHLOCKONEE RIVER FL OUT TO 20 NM...COASTAL WATERS FROM OCHLOCKONEE RIVER TO APALACHICOLA FL OUT TO 20 NM...COASTAL WATERS FROM SUWANNEE RIVER TO KEATON BEACH OUT 20 NM...COASTAL WATERS FROM APALACHICOLA TO DESTIN FL OUT 20 NM...WATERS FROM SUWANNEE RIVER TO APALACHICOLA FL FROM 20 TO 60 NM...WATERS FROM APALACHICOLA TO DESTIN FL FROM 20 TO 60 NM. && $$ SYNOPSIS/SHORT TERM/MARINE...DVD LONG TERM/AVIATION/FIRE WX...GOULD  FXUS62 KTAE 050901 AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 415 AM EDT THU OCT 6 2011 .SYNOPSIS... AT UPPER LEVELS... THE LARGE SCALE LONGWAVE OMEGA BLOCK PATTERN REMAINS HIGHLY AMPLIFIED. THIS IS HIGHLIGHTED BY TROUGH OVER WRN STATES WITH LOW JUST OFFSHORE FROM BRITISH COLUMBIA...SHARP RIDGE EWD TO EAST COAST WITH A WEAKNESS OVER CNTRL GULF COAST...AND A TROUGH JUST OFF ERN SEABOARD WITH 555DM JUST SE OF NEW ENGLAND COAST. DURING THE NEXT 24HRS...WRN TROUGH IS PROGGED TO EXPAND ACROSS THE WRN HALF OF THE COUNTRY...WITH A LEAD SHORTWAVE WAVE SHIFTING NEWD OUT OF THE FOUR CORNERS STATES AND THEN DAMPENING ACROSS THE HIGH PLAINS. THIS WILL PUSH RIDGE EWD WITH AXIS FROM SOUTHEAST TO MIDWEST TO UPPER GREAT LAKES REGION. DOWNSTREAM...STRONG CYCLONIC FLOW WILL PERSIST WITH ERN TROUGH THAT MOVES FURTHER OFFSHORE. ASSOCD LOW SHIFTS NEWD INTO FAR NE CANADA THEN OFFSHORE. LOCALLY... THIS RESULTS IN RISING HEIGHTS AND TEMPS. WITH LOCAL AREA BETWEEN DEPARTING TROUGH AND ADVANCING RIDGE...DRY MID LEVEL AIR WILL REMAIN INTACT PROVIDING MOSTLY CLEAR SKIES AND LITTLE OR NO CHANCE FOR RAIN. A WEAK LOW DEVELOPS IN WEAKNESS UNDER THE RIDGE FORMING WEAK TROUGHING OVER THE FLORIDA PENINSULA ON LATE THURSDAY...WEAKENS IT EARLY FRIDAY BEFORE REDEVELOPING IT IN THE SOUTHEAST GULF OF MEXICO LATE FRIDAY INTO WEEKEND. SATELLITE SHOWS THAT DEEP MOISTURE IS ALREADY IN SITU JUST S OF FL WITH HIGH LEVEL MOISTURE BEGINNING TO LIFT NWD ALONG THE E COAST OF FL...WHILE ALSO ADVECTING WWD FM THE WRN ATLC. (SEE EXTENDED FORECAST FOR DETAILS). AT LOWER LEVELS... MAIN FEATURE ARE HIGH CENTERED OVER THE CANADIAN MARITIMES...A 1026MB HIGH LOCATED OVER UPR OH VALLEY AND A DEEP LOW OFF OF NEW ENGLAND. LOCALLY THIS COMBINATION HAS FAVORED CONTINUED SUBSIDENCE ...LOW DEW POINTS AND CLEAR SKIES. DURING THE NEXT 24 HRS...AS LOW SHIFTS NEWD ACROSS THE CANADIAN MARITIMES...CANADIAN WILL SLIDE TO THE SOUTHEAST BECOMING CENTERED OVER NEW ENGLAND TONIGHT AND BE REINFORCED BY OH VALLEY HIGH ALSO SHIFTING ESE AND THEN BUILD DOWN EAST COAST ON FRI AND OFFSHORE BY FRI NIGHT. AS A RESULT...LOCAL GRADIENT WILL INCREASINGLY TIGHTEN THRU SHORT TERM...AND LONG FETCH OF ENE THEN E WINDS WILL INCREASE ACROSS THE NE GULF REGION ESPECIALLY IMPACTING ESPECIALLY THE MARINE AREA AND ERN COUNTIES. THIS HIGH BUILDING SWD WILL ALSO FAVOR DEVELOPMENT OF AN INVERTED TROUGH EWD OVER THE WATERS TONIGHT. THESE WINDS COMBINED WITH INVERTED TROUGH WILL ADVECT ADDITIONAL LOW LEVEL CLOUDS AND MOISTURE WWD TO THE CWA THURS INTO FRO AS INVERTED TROUGH STRENGTHENS. WDLY SCT RAIN POSSIBLE LATE THURS NIGHT THRU FRI SE THIRD OF CWA OTHERWISE...ANY RAIN SHOULD HOLD OFF UNTIL AFTER THE SHORT TERM PERIOD. WEAK UPPER LOW DEVELOPS OVER FL PENINSULA ON FRIDAY BUT AT THIS TIME...MODELS ARE NOT DEVELOPING A SURFACE REFLECTION LEAVING A LARGE AND STRENGTHENING SURFACE RIDGE TO DOMINATE THE EASTERN STATES AND FORECAST AREA THROUGH THE PERIOD. SHORT TERM...(TODAY THROUGH FRIDAY)... TODAY...NO POPS. HIGHS FROM AROUND 80 COAST TO MID 80S INLAND. TONIGHT...NO POPS. LOWS FROM MID 50S NORTH TO AROUND 60 AT COAST. THURSDAY...20 PCT POPS AT NIGHT SE THIRD OF AREA. HIGHS MID 80S. LOWS MID-UPPER 50S NORTH TO LOW 60S COAST. FRIDAY...ISOLD-WDLY SCT POPS. INCREASING LOW LEVEL CLOUDS FROM ATLC. HIGHS IN THE LOW 80S. && .LONG TERM (SATURDAY THROUGH NEXT WEDNESDAY)... THE EXTENDED FORECAST IS BEGINNING TO COME INTO A LITTLE BETTER FOCUS AS MOST GLOBAL MODELS ARE CONVERGING CLOSER TO THE ECMWF SOLUTION REGARDING THE SUBTROPICAL LOW THAT IS FORECAST TO DEVELOP. THE 04.12Z AND 05.00Z RUNS OF THE ECMWF HAVE BEEN CONSISTENT WITH PRODUCING A WEAK CLOSED SURFACE LOW (AROUND 1007 MB) NEAR THE WESTERN TIP OF CUBA AND THE FLORIDA STRAITS...AND THEN SLOWLY DEEPENING THE LOW AS IT PUSHES NORTH TO NEAR APALACHICOLA BY LATE TUESDAY. HIGHER CONFIDENCE WAS PLACED IN THE ECMWF THE LAST SEVERAL RUNS DUE TO ITS BETTER CONSISTENCY WITH THIS FEATURE...AND THAT CONTINUES TO BE THE CASE. THEREFORE...THE EXTENDED FORECAST WAS WEIGHTED ABOUT TWO-THIRDS 00Z ECMWF...AND ONE-THIRD 00Z GFS WHICH HAS MOVED MUCH CLOSER TO THAT SOLUTION. THE FACT THAT THE 05.00Z GFS ENSEMBLE MEAN IS VERY SIMILAR TO THE EUROPEAN MODEL LENDS MORE CONFIDENCE TO THE FORECAST THAN THE PAST TWO NIGHTS. OBVIOUSLY...THE WESTWARD TREND IN THE MODELS OVER THE PAST 24-48 HOURS PLACES THE TAE CWA MORE IN LINE FOR THE HEAVIER AXIS OF PRECIPITATION WITH ANY SUCH LOW THAT WOULD BE TRACKING NORTH. THE GFS ENSEMBLE MEAN PLACES NEARLY 3.5 INCHES OF RAIN JUST SOUTH OF APALACHICOLA BY WEDNESDAY AFTERNOON...AND 2 INCHES ACROSS OUR SOUTHEAST. WITH INCREASING MODEL SUPPORT FOR RAIN...POPS WERE NUDGED UP ANOTHER 5 TO 10 PERCENT BEYOND THIS WEEKEND. THE EVOLUTION OF THIS LOW IS STILL VERY INTERESTING. AS THE PRESSURE AND HEIGHT FALLS TAKE PLACE AROUND THE FLORIDA STRAITS INTO THE WEEKEND...THAT AREA WILL BE IN SOMEWHAT OF A COUPLED JET STRUCTURE AND CERTAINLY IN THE RIGHT ENTRANCE REGION OF A 60-70 KT UPPER LEVEL JET. THERE WILL BE HORIZONTAL TEMPERATURE AND THICKNESS GRADIENT FROM NORTH-SOUTH ACROSS THE DEVELOPING LOW. THEREFORE ITS ORIGINS WILL NOT BE TROPICAL IN NATURE. AND YET...AS THE LOW DEVELOPS...THE ECMWF/GFS MODEL SOLUTIONS SHOW INCREASING TROPICAL CHARACTERISTICS. BY MONDAY-TUESDAY THEY INDICATE MORE OF A WARM CORE STRUCTURE...WITH SLIGHTLY HIGHER 1000-500MB THK AT THE CENTER OF THE VERTICALLY STACKED CIRCULATION...AND THERMAL WIND VECTORS IN THE SAME LAYER WRAP AROUND THE LOW IN A CLOCKWISE FASHION. THE LOW WILL BE PASSING OVER WATER THAT HAS SEA SURFACE TEMPERATURES STILL 29-30C...AND 850-300MB BULK SHEAR OVER MUCH OF THE EASTERN GULF DROPS TO AROUND 5-10 KNOTS BY MONDAY. BOTH ARE INDICATIVE OF FAVORABLE CONDITIONS FOR TROPICAL DEVELOPMENT. CERTAINLY...THIS LOW WILL BE ONE TO KEEP AN EYE ON...EVEN IF IT ONLY ATTAINS SUBTROPICAL STATUS. AT THE VERY LEAST IT SHOULD BE A BREEZY AND WET START TO THE NEXT WORK WEEK. && .MARINE...AN EASTERLY WIND SURGE OVERNIGHT HAS CAUSED WINDS AND SEAS TO INCREASE FROM EAST TO WEST. CAUTIONARY LEVELS ARE EXPECTED OVER APALACHEE BAY AND NEARBY OFFSHORE WATERS. AS THE EASTERLY SURGE DIMINISHES THIS AFTERNOON...WINDS AND SEAS ARE FORECAST TO FALL BELOW HEADLINE CRITERIA. ANOTHER EASTERLY SURGE IS EXPECTED ON TONIGHT. HOWEVER... AS THE SURFACE RIDGE STRENGTHENS INTO THE AFTERNOON ON THURSDAY...CAUTIONARY LEVELS ARE FORECAST TO PERSIST FOR THE DURATION OF THE AFTERNOON. BY THE END OF THE WEEK...AS THE RIDGE CONTINUES TO STRENGTHEN ADVISORY CONDITIONS WILL BE POSSIBLE AND COULD POSSIBLY CONTINUE THROUGH THE WEEKEND. && .AVIATION...THROUGH 06Z THURSDAY. VFR CONDITIONS ARE ONCE AGAIN EXPECTED TO PREVAIL THROUGH THE TAF PERIOD AT ALL FIVE TERMINALS. SOME SCATTERED MID LEVEL CLOUDS ARE MOVING THROUGH THE AREA FROM WSW-ENE AT TAF ISSUANCE TIME (05Z) AND CLOUD HEIGHT SAMPLING TOOLS SUGGEST THESE AROUND AROUND 12000 FT AGL. A LAYER AROUND THIS HEIGHT WAS INCLUDED PRIOR TO 13Z AT THE THREE EASTERN TERMINALS (TLH...VLD...ABY). LOW LEVEL FLOW REMAINS EASTERLY TODAY...WHICH SHOULD FINALLY BRING IN SOME INCREASED LOW LEVEL MOISTURE. SOME DIURNAL CUMULUS ARE EXPECTED...ESPECIALLY AT VLD AND TO A LESSER EXTENT TLH. ANY CU SHOULD REMAIN SCT AROUND 4000-5000 FT. ONE VSBY CONCERN IS RELATED TO A SMOLDERING WILDFIRE THAT FLARED UP AGAIN TODAY ABOUT 40 MILES ENE OF VLD. THE SMOKE PLUME ON SATELLITE SEEMED SMALL AND RAGGED...SO NO VSBY RESTRICTIONS WERE INCLUDED. HOWEVER...IT WOULD NOT BE SURPRISING TO SEE SOME 4-7SM VSBYS EARLY THIS MORNING WITH HAZE IF WINDS ORIENT CORRECTLY. && .FIRE WEATHER... WE ARE LOOKING AT ANOTHER DAY OF LOW RH TODAY ALTHOUGH THE DURATION OF RH BELOW CRITICAL THRESHOLDS WILL BE LESS THAN IN RECENT DAYS. MODIS SATELLITE PASS FROM YESTERDAY AFTERNOON REVEALED MANY SMOKE PLUMES ACROSS ALABAMA...GEORGIA...AND NW FLORIDA SO IT SEEMS THAT CONDITIONS WERE FAVORABLE FOR AT LEAST A FEW WILDFIRES TO BREAK OUT ACROSS OUR FIRE WEATHER ZONES. DISPERSIONS ARE FORECAST TO BE MUCH HIGHER ACROSS THE FLORIDA FIRE WX ZONES TODAY (75 TO 90). SUCH VALUES ONLY NEED TO COINCIDE WITH ONE HOURLY OBSERVATION OF RH OF 35 PERCENT OR LOWER FOR RED FLAG CONDITIONS TO BE MET...SO A MORE EXPANSIVE RED FLAG WARNING WAS ISSUED FOR TODAY. DISPERSIONS REMAIN HIGH FOR THURSDAY...AND ALTHOUGH LOW LEVEL MOISTURE WILL BE ON THE INCREASE...THE FIRE WEATHER WATCH WAS EXPANDED TO COVER THE SAME AREA AS TODAYS WARNING FOR SIMPLICITY. DATA FROM SACC SUGGESTS ERC VALUES RUNNING AROUND 90TH PERCENTILE EVEN IN OUR GEORGIA COUNTIES. WITH THIS IN MIND...AND ONGOING DROUGHT...IT SHOULD BE NOTED THAT EVEN IF EXACT RED FLAG CONDITIONS ARE NOT MET...THE FIRE DANGER WILL BE QUITE HIGH AREAWIDE THE NEXT SEVERAL DAYS AND PARTICULARLY TODAY. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 85 55 85 61 84 / 0 0 0 20 10 PANAMA CITY 80 62 86 63 82 / 0 0 0 10 10 DOTHAN 84 54 84 57 83 / 0 0 0 0 0 ALBANY 85 54 84 57 82 / 0 0 0 0 10 VALDOSTA 85 56 84 60 82 / 0 0 0 20 10 CROSS CITY 84 59 85 63 83 / 0 0 10 20 20 APALACHICOLA 82 61 83 65 81 / 0 0 0 20 10 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING FROM 1 PM EDT /NOON CDT/ THIS AFTERNOON TO 7 PM EDT /6 PM CDT/ THIS EVENING FOR THE FOLLOWING ZONES: CALHOUN...CENTRAL WALTON...COASTAL BAY...COASTAL JEFFERSON...COASTAL WAKULLA...GADSDEN...HOLMES...INLAND BAY...INLAND FRANKLIN...INLAND GULF...INLAND JEFFERSON...INLAND WAKULLA...INLAND WALTON...JACKSON...LEON...LIBERTY...WASHINGTON. FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR THE FOLLOWING ZONES: CALHOUN...CENTRAL WALTON... COASTAL BAY...COASTAL JEFFERSON...COASTAL WAKULLA... GADSDEN...HOLMES...INLAND BAY...INLAND FRANKLIN...INLAND GULF...INLAND JEFFERSON...INLAND WAKULLA...INLAND WALTON... JACKSON...LEON...LIBERTY...WASHINGTON. GM...NONE. && $$ BLOCK/LAMERS  FXUS62 KTAE 081011 AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 511 AM EST Sun Jan 8 2012 .SYNOPSIS...At the surface, a ridge of high pressure remained in place from the Florida Peninsula extending back through the Bahamas. Meanwhile, a cold front had stalled to the north of this area of high pressure, from northern Louisiana into the Carolinas. Other than a few isolated showers, there was no notable precipitation across the southeast corner of the country including our local forecast area. However, the calm winds and (relatively) clear skies associated with the high pressure were contributing to yet another night of fog. The fog was dense in spots, but the expansion of the dense fog was less uniform than in past nights, complicated by a smattering of mid-level clouds slowly traversing north Florida and southern Georgia. The stalled front is likely to remain locked in place over the next several days, and thus persistence will play a large role in the forecast. The focus over the first four days of the forecast is related to a strong upper level closed low that will be ejecting out of the southern Plains, and affecting our forecast area Tuesday and Wednesday. The feature that will eventually develop into this low is in the form of a digging trough currently over the desert Southwest. && .NEAR TERM [through Tonight]...Compared to the past several nights, the development and expansion of dense fog has been more complex early this morning. This is largely because of a few isolated showers in our southwestern areas, and some altostratus that has been slowly moving east across our area. The mid-level clouds have limited fog development across most of southwest Georgia, but it is finally beginning to set in across the rest of the area. We have expanded the Dense Fog Advisory several times, and this will be done once more with the forecast updates recently sent out. The gap in the advisory area from Panama City NNE to Marianna and around the Dothan and Bainbridge areas will be filled in. KECP and KBIJ have already dipped down occasionally to near 1/4SM. Despite a few showers approaching Panama City right now that may cause the fog to temporarily lift, the thinking is that it should set in once more closer to daybreak. This will give us a more uniform advisory area. With forecast soundings for the NAM and local 4km WRF-ARW indicating that the radiation inversion won't break until around 15z, the expiration time of the advisory has been extended an additional hour. After the fog burns off, the focus turns to the possibility of some afternoon showers and thunderstorms. Although the primary surface front will remain north of the area, there should be some increase in low-level moisture advection with the southern edge of a ribbon of stronger 0-2km moisture transport vectors clipping through the northwest third of our forecast area. There is about a 0.3" increase in PWATs through the course of the day over this area. The 4km-WRF runs have been consistent across various flavors of the model in generating some scattered showers in the afternoon. In fact, there appears to be enough instability for some thunderstorms as well. The WRF models, RUC, and NAM forecast soundings all show about 300-500 j/kg of SBCAPE extending up to about the -30C level, so there could be vigorous enough updrafts for some lightning. It looks like another warm day, and with negligible low-level advection the high temperature forecast was a blend of the MAV, MET, and persistence. Highs in the mid-70s should be about 10-15 degrees above normal. && .SHORT TERM [Monday through Tuesday]...Monday is expected to be a quieter day comparatively to Tuesday. Slight shortwave ridging ahead of the approaching trough, and the stalled front remaining north of our area, are expected to keep precipitation chances low. Other than immediately along our northern row of counties, the forecast was kept dry with PoPs generally 5-10%. Partly cloudy skies and a similar low-level temperature profile to what we are experiencing this weekend should support another day with highs in the mid-70s. For Tuesday, the closed upper level low will kick out from the southern Plains and begin migrating east across the Gulf Coast states. During the day, there should be a slow ramp-up in cloud cover and precipitation chances from west to east. By 00z Wednesday the majority of the models have the 500mb low centered near Shreveport, LA, and thus the bulk of the deeper layer QG convergence will still be focused to the west of our area. As such, PoPs were kept on the low end of the guidance envelope. However, we are still expecting some scattered showers to develop over most of the area by Tuesday afternoon as low-level WAA increases. Models are very reluctant to show much instability prior to 00z Wednesday, and this makes sense as the colder core of the mid-upper level low will remain west of our area. Therefore, we were slow to introduce thunder during the day time. It looks like most of the thunderstorm threat would be after dark, and that is discussed in more detail below. && .LONG TERM [Tuesday Night through next Sunday]...Guidance has come into good agreement for the early portion of the extended forecast period. Upper low/sfc low will begin the period situated near the Arklatex, with a cold front reaching southeast to the Mississippi coast and into the Gulf. As the system moves eastward through the overnight hours, good divergent pattern aloft will aid in maintaining broad area of large scale lift and resulting precipitation. Guidance also shows a 60-70kt mid-level jet moving into the panhandle and reaching the Big Bend by sunrise on Wednesday. This jet, along with significant low-level directional and speed shear, will create a very favorable kinematic environment for rotating storms. The weak parameter for severe weather continues to be the amount of instability available. 00Z GFS and Canadian are a bit more aggressive than the 00Z Euro with respect to low-level instability, each showing up to around 500j/kg of BL CAPE right along the front. With the favorable shear parameters, this would likely be sufficient to maintain a few severe thunderstorms Tuesday night into Wednesday morning as the front sweeps across the forecast area. Will continue to monitor this potential severe weather event closely over the coming days. Much drier air will push in behind the front during the day on Wednesday. However, without much in the way of cold air in waiting, temperatures will only modestly cool off. Significant uncertaintly exists as Friday and the weekend approaches. Guidance has reversed itself over the past few days, with the GFS now indicating a wet Gulf low by the end of the week, while the Euro maintains a dry frontal passage. The guidance was roughly reversed with the scenario 48 hours ago. Since the GFS has maintained this solution for a couple of runs, and has some support from the 00z Canadian, will begin to nudge PoP up for Thursday night through Friday as low pressure develops over the western Gulf and lifts east-northeastward. A colder airmass is expected to follow this system into the area for next weekend. && .MARINE...The main marine concern over the first 48-60 hours of the forecast is related to fog. A Marine Dense Fog Advisory was hoisted through 16z for our coastal zones within 20 NM of the shoreline. MODIS 1km 11-3.9u satellite image from 0703z showed some hints of fog over the waters, especially over protected bays and waterways. Another prominent area of fog was located between Alligator Point and the mouth of the Aucilla River along the northern rim of Apalachee Bay. It is uncertain if or when this fog will dissipate, and that is something the subsequent shift will have to examine in greater detail. As moist southeasterly flow continues over the next several days and dewpoints steadily climb, sea fog will likely be a continued concern over various parts of the waters. The predictability of this is low, but the extended potential for fog will be highlighted in the HWO and the synopsis section of the CWF. Advisory-level winds still look like a good bet around the cold front passage later Tuesday and very early Wednesday. The other concern would be related to surf heights on the Panhandle beaches Tuesday-Wednesday. The latest 06z run of the SWAN yields 3-4 foot surf along Walton County Tuesday, and around 2 feet elsewhere. This increases to 4-5 feet on most Panhandle beaches for Wednesday. This doesn't quite hit Surf Advisory criteria, but nonetheless stronger and more frequent rips should become likely by Tuesday afternoon. && .AVIATION [through 06z Monday]...Dense fog and conditions near airport minimums will continue to plague area terminals through the morning hours. An area of mid-level clouds is currently moving across southwest Georgia and the western Big Bend. This cloud deck will limit poor conditions at KABY and possibly result in some improvement at KTLH by 08-09Z. The lingering clouds at KECP should also keep conditions generally above airport minimums. VFR conditions are anticipated at all terminals by late morning as the fog burns off. However, fog will once again be an issue Sunday night. && .FIRE WEATHER...A moist low-level airmass will remain in place across the region into the middle of next week, with RH values remaining well above critical levels. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 75 48 76 50 73 / 20 10 10 10 30 Panama City 70 57 73 58 69 / 20 10 10 20 50 Dothan 74 53 74 54 71 / 40 30 10 20 50 Albany 73 52 75 51 72 / 30 30 10 10 40 Valdosta 75 48 76 49 74 / 10 10 10 10 30 Cross City 76 47 76 48 74 / 0 10 10 10 20 Apalachicola 69 55 71 58 68 / 10 10 10 10 40 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...Dense Fog Advisory until 9 AM CST this morning for Coffee-Dale- Geneva-Henry-Houston. GA...Dense Fog Advisory until 10 AM EST this morning for Brooks- Decatur-Early-Grady-Lowndes-Miller-Seminole-Thomas. FL...Dense Fog Advisory until 10 AM EST /9 AM CST/ this morning for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson-Coastal Taylor- Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie- Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor- Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon-Liberty- Madison-South Walton-Washington. GM...Dense Fog Advisory until 11 AM EST this morning for Apalachee Bay-Coastal waters From Ochlockonee River to Apalachicola FL out to 20 NM-Coastal waters from Suwannee River to Keaton Beach FL out 20 NM-Coastal waters from Apalachicola to Destin FL out 20 NM. && $$ Synopsis & Near Term...Lamers Short Term...Lamers Long Term...Camp Marine...Lamers/Camp Aviation & Fire Wx...Camp