FXUS63 KGRB 130855 AFDGRB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 255 AM CST SAT DEC 13 2014 FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND SUNDAY ISSUED AT 254 AM CST SAT DEC 13 2014 CLOUD/FOG TRENDS ALONG WITH LIGHT PCPN WILL BE THE PRIMARY ISSUE THROUGH SUNDAY. EARLY THIS MORNING MUCH OF THE FORECAST AREA WAS UNDER BLANKET OF STRATUS AND FOG. SATELLITE IMAGERY DID SHOW A SMALL POCKET OF CLEAR SKIES OVER FAR NORTHEAST WISCONSIN NEAR IMT...WITH A MORE SIGNIFICANT CLEAR REGION WORKING OVER SOUTHWEST WISCONSIN. THIS CLEARING REGION MAY BRUSH WAUSHARA COUNTY EARLY THIS MORNING BUT RAPIDLY DEVELOPING STRATUS OVER IOWA WAS QUICKLY FILLING IN THIS HOLE. GUIDANCE SUGGESTS SKIES TO GO PARTLY CLOUDY THIS AFTERNOON OVER CENTRAL AND EAST CENTRAL WISCONSIN. IT IS A SMALL POSSIBILITY DUE TO THE INCREASING WINDS/GRADIENT ACROSS THE AREA. WILL CONTINUE TO TREND TO MORE CLOUDS FOR NOW. THIS INCREASING SOUTHWEST FLOW WAS ALSO ALLOWING INCREASING DEWPOINTS TO WORK OVER THE SNOW COVER EARLY THIS MORNING WITH WIDESPREAD DENSE FOG OVER WESTERN WISCONSIN STARTING TO SPILL INTO CENTRAL AND NORTH CENTRAL WISCONSIN. WILL ISSUE A DENSE FOG ADVISORY FOR THESE LOCATIONS THROUGH MOST OF THE MORNING HOURS AND MONITOR FOR ANY NEEDED EXPANSION TO THE EAST. MODELS IN GOOD AGREEMENT WITH LIGHT MEASUREABLE PCPN EVENTUALLY SPREADING OVER THE AREA THROUGH SUNDAY. CONTINUED INCREASING DEWPOINTS WILL FURTHER SATURATE THE BOUNDARY LAYER AND MAY PROMPT ANOTHER DENSE FOG ADVISORY HEADLINE LATE TONIGHT INTO SUNDAY. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY ISSUED AT 254 AM CST SAT DEC 13 2014 MEAN FLOW STILL EXPECTED TO SPLIT OVER THE ERN PACIFIC WITH A NRN STREAM RUNNING ACROSS SRN CANADA (WITH AN OCNL DIP INTO THE NRN TIER OF STATES) AND A SRN BRANCH RUNNING ACROSS THE SRN HALF OF THE CONUS. AN ACTIVE START TO THE WORK WEEK AS AN INITIAL SRN STREAM SYSTEM LIFTS NE INTO THE GREAT LAKES AND BRINGS RAIN... THEN SNOW TO WI. WEATHER TO TURN QUIET THRU MID-WEEK WITH HI PRES IN CONTROL...BEFORE ATTENTION TURNS TO THE NEXT SRN STREAM SYSTEM WHICH MODELS DISAGREE WITH THE EVENTUAL TRACK FOR LATE NEXT WEEK. TEMPS TO BE MUCH ABOVE NORMAL THRU MON WITH READINGS FALLING TO ONLY SLIGHTLY ABOVE NORMAL FOR THE BULK OF NEXT WEEK. SRN STREAM SYSTEM TO BE MOVING ACROSS THE CNTRL/SRN PLAINS SUNDAY NGT AND CONTINUING TO PUMP WARM/MOIST AIR INTO WI ON S-SW WINDS. THE DEPTH OF THE SATURATION WL CONT TO INCREASE THRU THE NGT... THUS AREAS OF DRIZZLE MAY TURN TO RAIN CHCS AFTER MIDNGT. OTHERWISE...A CLOUDY/MILD NGT IN STORE AND WL HAVE TO WATCH THE FOG THICKNESS AS LOCALLY DENSE CONDITIONS/POSSIBLE HEADLINES CAN'T BE RULED OUT. MIN TEMPS TO RANGE FROM THE UPR 30S TO LWR 40S. THE SYSTEM IS PROGGED TO LIFT NE INTO THE MIDWEST ON MON AND WITH MID-LEVEL FORCING/LIFT ON THE INCREASE INTO WI...WE SHOULD SEE PCPN CHCS ALSO ON THE INCREASE. HIGHER QPF AMOUNTS SHOULD STILL BE TO OUR SW CLOSER TO THE SYSTEM...THUS THE HIGHEST POPS HAVE BEEN PLACED OVER CNTRL WI (LIKELY). MON TO BE THE LAST OF THE MILD DAYS WITH MAX TEMPS TO RANGE FROM THE LWR 40S NORTH...MID TO UPR 40S E-CNTRL WI. MODELS HAVE FINALLY COME INTO FAIRLY GOOD AGREEMENT BY TAKING THIS SYSTEM INTO THE WRN GREAT LAKES MON NGT (THE SFC LOW TO REACH ROUGHLY SE WI/SRN LAKE MI BY 12Z TUE). THE DEFORMATION ZONE TO EXTEND FROM SRN MN TO N-CNTRL WI...SO HIGHER QPF MAY NEED TO BE SHIFTED A BIT TO THE NW FROM THE PREVIOUS FCST. THE MAIN FCST ISSUE WL BE TIMING OF THE PCPN CHANGEOVER ACROSS NRN AND CNTRL WI AS COLDER AIR GETS DRAWN INTO THE STATE. SNOW SHOULD BEGIN TO MIX WITH RAIN DURING THE LATE EVENING N-CNTRL AND THEN OVER FAR NE/ PARTS OF CNTRL WI AFTER MIDNGT. ERN WI SHOULD REMAIN ALL LIQUID THRU THE NGT. THERE COULD BE MINOR ACCUMULATIONS OVER N-CNTRL WI BY DAYBREAK (GENERALLY AN INCH OR LESS) AS THE MIX DOES CHANGE TO ALL SNOW. MIN TEMPS TO RANGE FROM THE MID 20S N-CNTRL...TO THE MID 30S NEAR LAKE MI. RAIN OR MIXED PCPN OVER ERN WI WL EVENTUALLY SWITCH TO SNOW ON TUE AS COLDER AIR OVERSPREAD THE REGION BEHIND THE SFC LOW WHICH THE MODELS TAKE INTO NRN SECTIONS OF LWR MI OR LAKE HURON. ADDITIONAL MINOR ACCUMULATIONS ARE POSSIBLE...ESPECIALLY TUE MORNING BEFORE DEEPER MOISTURE BEGINS TO PULL AWAY FROM WI DURING THE AFTERNOON HOURS. HARD TO PUT A TOTAL ACCUMULATION NUMBER JUST YET DUE TO THE UNKNOWN TIMING OF THE PCPN CHANGEOVER MON NGT AND THE EXTENT OF MOISTURE OVER THE AREA ON TUE. AN EARLY ESTIMATE WOULD BE AROUND ONE-HALF INCH OVER E-CNTRL WI TO AS MUCH AS THREE INCHES N-CNTRL WI WHERE A LITTLE LAKE ENHANCEMENT IS POSSIBLE ON TUE DUE TO N-NW WINDS OFF OF LAKE SUPERIOR. TEMPS ARE EXPECTED TO BE STEADY OR SLOWLY FALL THRU THE DAY AS THE CAA TAKES OVER. THERE CONTS TO BE SOME MODEL DISPUTE WITH RESPECT TO THE TRAILING NRN STREAM SHORTWAVE TROF TUE NGT AS THE GFS CONTS TO CLOSE THIS FEATURE OFF INTO AN UPR LOW OVER ND. OTHER MODELS FAVOR A MORE PROGRESSIVE EWD MOVEMENT AND BRING THE SHORTWAVE TROF INTO THE GREAT LAKES. HAVE FOLLOWED THE MAJORITY SOLUTION HERE WITH A SMALL CHC OF SNOW SHWRS OR FLURRIES ACROSS THE FCST AREA. MAIN CONCERN WL BE N-CNTRL WI WHERE PREVAILING NW WINDS AND 8H TEMPS AROUND -12C OVER WRN LAKE SUPERIOR MAY PROVIDE LAKE EFFECT. THIS SYSTEM DEPARTS THE REGION WED...LEAVING ONLY A MINIMAL CHC OF LAKE EFFECT SNOW SHWRS PRIMARILY OVER VILAS CNTY. THE REST OF THE FCST AREA SHOULD SEE PARTLY CLOUDY SKIES AS HI PRES BUILDS OVER THE UPR MS VALLEY. MAX TEMPS BY WED TO ONLY BE A FEW DEGS ABOVE NORMAL. A QUIET AND SOMEWHAT SEASONAL STRETCH OF WEATHER EXPECTED FOR THE LATTER PART OF THE WORK WEEK AS THE SPRAWLING AREA OF HI PRES SETTLES OVER THE GREAT LAKES. IT WOULD BE NICE IF THE GFS PLAYED ALONG WITH THE OTHER MODELS/ENSEMBLES AS THE GFS RACES THE NEXT SRN STREAM SYSTEM ACROSS THE SRN PLAINS (THU) AND OHIO/TN VALLEYS (FRI). OBVIOUSLY...THIS SOLUTION WOULD BRING MORE CLOUDS...EVEN PCPN CHCS TO NE WI AT WEEK'S END. HAVE DISMISSED THE GFS AS AN OUTLIER AND KEEP THU/FRI DRY WITH TEMPS A FEW DEGS ABOVE NORMAL. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1042 PM CST FRI DEC 12 2014 LOW-LEVEL MOISTURE TRAPPED BLO STG INVERSION WL KEEP IFR/LIFR CONDITIONS ACRS THE AREA THROUGH THE PERIOD. EXPECT CIGS/VSBYS TO EDGE DOWN A BIT MORE OVERNIGHT...THEN UP A BIT TOMORROW. MOISTURE SHOULD BE DEEP ENOUGH FOR SOME DZ BY TOMORROW NGT. && .HYDROLOGY... ISSUED AT 254 AM CST SAT DEC 13 2014 THE FLOOD WARNING FOR ICE JAMS ON THE WOLF RIVER IN KESHENA WILL CONTINUE. CALLS LATE FRIDAY SUGGESTS LITTLE CHANGE IN THE HEIGHT OF THE ICE AND WATER. WARMER TEMPERATURES THIS WEEKEND AND RAIN MONDAY MAY PRODUCE RUN OFF AND FLUCTUATING LEVELS THROUGH TUESDAY. ITS POSSIBLE THE WARNING MAY BE EXTENDED THROUGH TUESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 11 AM CST THIS MORNING FOR WIZ005-010- 018>020-030-031-035>037-045. && $$ SHORT TERM.....TDH LONG TERM......KALLAS AVIATION.......SKOWRONSKI HYDROLOGY......TDH  FXUS63 KGRB 122040 CCA AFDGRB AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE GREEN BAY WI ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI 239 PM CST THU FEB 12 2015 .SYNOPSIS...ISSUED AT 239 PM CST THU FEB 12 2015 WATER VAPOR LOOP AND RUC ANALYSIS REVEALS AMPLIFIED PATTERN FEATURING WEST COAST RIDGE AND BROAD UPSTREAM TROF ACROSS MUCH OF NORTH AMERICA. MODELS INDICATE THIS PATTERN WILL STAY IN PLACE OVER MUCH OF NEXT WEEK ALLOWING FOR PERIODIC SURGES OF ARCTIC AIR INTO THE REGION RESULTING IN BLO NORMAL TEMPS. MODELS ADVERTISE ONLY PERIODIC LIGHT PCPN WITH A FEW CLIPPER SHORTWAVES TRAVERSING AREA. && .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 239 PM CST THU FEB 12 2015 MINS TEMP FCST TONIGHT COULD BE TRICKY AS WINDS WILL DIE OFF WITH SFC RDG MOVING ACROSS THE AREA. ALSO WAA MID-HIGH CLOUDS WILL BE SPREADING INTO THE AREA AHEAD OF SHORTWAVE AND ASSOC SFC LOW DIVING DOWN FM CENTRAL CANADA. THESE CLOUDS DEPENDING ON HOW THICK THEY ARE MAY TEMPER RADIATIONAL COOLING UNDER LIGHT WIND REGIME. GIVEN UNCERTAINTY WITH CLOUD THICKNESS DECIDED TO USED A BLEND OF COLDER BASE REG GEM/ECMWF TEMPS AND MOS GUIDE TEMPS WHICH WAS CLOSE TO PREV FCST AND IN MEDIUM RANGE OF TEMP GUIDANCE. BACKED OFF SLIGHTLY ON POPS FOR FRI AS MODELS INDICATE BEST MOISTURE AND ISENTROPIC ASCENT STAYING GENERALLY NORTH OF WI CLOSER TO TRACK OF SHORTWAVE AND ASSOC SFC LOW. HAVE POPS RANGING FROM HIGH CHC (AROUND 50 PCT) NORTH TO LOWER CHC 30-40 POPS FOR SOUTHERN PORTIONS OF CWA. WAA WL HELP TEMPS RECOVER TO AROUND 20F...BUT MAX TEMPS PROBABLY WON/T OCCUR UNTIL LATE IN THE DAY SO ADJUSTED DIURNAL CURVE ACCORDINGLY. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY ISSUED AT 327 AM CST THU FEB 12 2015 A STABLE PATTERN WILL CONTINUE TO BE PRESENT THROUGH THE END OF NEXT WEEK WHICH WILL CONSIST OF A DEEP TROUGH CENTERED ACROSS THE GREAT LAKES AND A RIDGE OVER FAR WESTERN NORTH AMERICA. THIS PATTERN WILL BRING PERIODIC INTRUSIONS OF BITTERLY COLD ARCTIC AIR INTO THE REGION...THE COLDEST OF WHICH WILL ARRIVE THIS WEEKEND. BOTH THE ECMWF AND GFS ARE COMPARABLE IN REGARDS TO THE MAGNITUDE OF THE COLD AIR PUSHING ACROSS THE REGION THIS WEEKEND...AND AGREE PRETTY WELL DURING LATER PERIODS TOO...SO A GENERAL MODEL BLEND WILL SUFFICE. FRIDAY NIGHT THROUGH SATURDAY NIGHT...A STRONG SHORTWAVE WILL BE DIVING ACROSS THE WESTERN GREAT LAKES FRIDAY NIGHT AND WILL DRIVE AN ARCTIC FRONT ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE EVENING. BEHIND THE FRONT...WINDS WILL TURN TO THE NORTHWEST AND BECOME STRONG AND GUSTY WHILE USHERING A BITTERLY COLD AIRMASS ACROSS THE REGION. 850MB TEMPERATURES WILL BE FALLING BETWEEN -25 TO -30C BY 12Z SATURDAY. TRAJECTORIES WILL BECOME FAVORABLE FOR LAKE EFFECT SNOW IN THE SNOW BELT...BUT THE 850MB TEMPS WILL BE TOO COLD FOR SIGNIFICANT ACCUMS. PERHAPS COULD GET AN INCH OR TWO. OTHERWISE SHOULD SEE A MOSTLY CLOUDY NIGHT WITH TEMPS FALLING BETWEEN 5 ABOVE AND 5 BELOW ZERO. WIND CHILLS WILL FALL INTO THE ADVISORY RANGE OVER N-C WISCONSIN LATE. ARCTIC HIGH PRESSURE WILL BE BUILDING INTO THE REGION ON SATURDAY...BUT WOULD NOT BE SURPRISED IF TEMPS CONTINUED TO FALL SATURDAY MORNING. COMBINED WITH 30-35 MPH WIND GUSTS...WIND CHILLS WILL HOVER RIGHT AROUND -20F TO -30F ALL DAY DESPITE INCREASING SUNSHINE THROUGH THE DAY. HIGH PRESSURE ARRIVES FOR SATURDAY NIGHT. IF WINDS DECOUPLE...TEMPS COULD PLUMMET TO 30 BELOW OVER N-C WISCONSIN...BUT ITS NOT A SURE BET. WILL LOWER TEMPS SOME THERE. REST OF THE FORECAST...ARCTIC HIGH PRESSURE WILL ENSURE ANOTHER BITTERLY COLD DAY ON SUNDAY ALBEIT WITH A FAR AMOUNT OF SUN. A CHANCE OF LIGHT SNOW WILL ARRIVE SUNDAY NIGHT INTO MONDAY AS WEAK CLIPPERS TRAVERSE THE REGION. ANY ACCUMS LOOK TO BE MINOR. BEHIND MONDAYS CLIPPER...ANOTHER SURGE OF ARCTIC AIR WILL ARRIVE. THIS AIR WILL NOT BE NEARLY AS COLD AS THE TEMPS OVER THE WEEKEND. THEN MODERATING TEMPS MIDWEEK AHEAD OF THE NEXT CLIPPER. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1205 PM CST THU FEB 12 2015 EXPECT VFR CONDITIONS THROUGH TONIGHT FOR ALL TAF SITES UNDER BUILDING HIGH PRESSURE. WARM ADVECTION/LIFT AHEAD OF THE NEXT LOW PRES SYSTEM DESCENDING FM ONTARIO WILL THEN BRING IN SOME LIGHT SNOW LATE FRI MORNING/AFTERNOON AS CONDITIONS LOWER TO MVFR. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......VOSS SHORT TERM.....VOSS LONG TERM......MPC AVIATION.......VOSS  FXUS63 KGRB 212059 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 259 PM CST Thu Feb 21 2019 Forecast discussion for routine afternoon forecast issuance .SHORT TERM...Tonight and Friday Issued at 258 PM CST Thu Feb 21 2019 Fairly quiet weather through much of the short-term portion of the forecast, which will be the calm before the upcoming weekend winter storm. Tonight into Friday: The weather during this time period will be largely controlled by a surface ridge. This will keep the weather fairly quiet, in regards to any precipitation. Aloft, the area will be under near zonal flow to begin with; however, the western Great Lakes will be just ahead of falling heights overnight into Friday. This will lead to increased west to southwesterly flow into the area just above the surface. The main impact this would have is an increase in cloud cover as moisture to the southwest of the area begins advecting in. This would likely be mid to high clouds, which will generally have an impact on temperatures; however, there will be an increase in cloud thickness from the west late Friday afternoon. This will be ahead of the next system. Overnight lows may be a bit tricky tonight as this will be highly dependent upon cloud cover. Current thinking is that mid to high clouds will be reinforced across the area, helping to keep temps a bit higher; therefore, opted not to go with the coldest guidance, but did trend a little colder. If the clouds are too thin or take a while to come in, then temperatures could tank overnight. .LONG TERM...Friday Night Through Thursday Issued at 258 PM CST Thu Feb 21 2019 Focus in this part of the forecast remains on the winter storm due to impact the region this weekend. The forecast track of the cyclone has been quite steady over the past 24 hours, judging by looking at the gfs ensemble mean, and favor the ecmwf for the details. Friday night and Saturday...A 35 kt low level jet is anticipated to develop over the northern Mississippi Valley and push east across the state on Friday night. Increasing elevated moisture transport and mid-level fgen will lead to light precip spreading in from the west after midnight over central and north-central WI but may wait until after 12z Sat before moving into eastern WI. Timing has slowed down some over the past 24 hours, but still appears that all areas will have a chance of light snow late Friday night into Saturday morning. Up to an inch appears possible with best chances over north-central WI. As the warm advection pushes east of the region by mid to late morning, models insist on mid-level moisture scouring out, while levels below 700-800mb remain saturated. This setup is favorable for periods of drizzle through the rest of the day. Temperatures should begin to rise above freezing over eastern WI by 9-10 am, so the threat of freezing drizzle should be rather minimal. But with temps not warming above 32F until midday or early afternoon across the far north, could see a freezing drizzle threat for a few hours. Under cloudy skies, highs on Saturday will warm into the mid 30s at most locations. Saturday night and Sunday...An intensifying area of low pressure remains on track to move from northern Missouri to northern Lake Michigan on Saturday night. Strong forcing on the nose of a 50-60 kt low level jet and differential positive vorticity advection will push heavy precip from southwest to northeast across the area from mid to late evening. Wouldnt be surprising to see some thunder as well, given the mid-level lapse rates of 6.5-7.5 c/km. Thermal profiles suggest mainly rain across eastern WI as this heavy precip arrives, snow across north-central WI, and a wintry mix in between. As the upper cyclone moves overhead, cooling temperatures should lead precip changing from rain to snow from northwest to southeast late Saturday night over eastern WI. However, snowfall is expected to be very heavy across central and north-central WI, with an inch per hour snowfall rates likely. 6 to 10 inches of accumulations will be possible by morning over the north. The heaviest snow will most likely have pushed off to the north by mid Sunday morning, but gusty northwest winds to 40 or 45 mph will likely lead to hazardous conditions continuing through the afternoon. Blowing and drifting snow could become a significant concern, particularly over central WI which is more prone to this type of hazard than further north. In the end, 8 to 12 inches looks likely across north-central WI from the system, 5 to 8 inches over central WI, while amounts may only reach 1 to 3 or 2 to 4 inches over eastern WI. Rest of the forecast...Some light snow showers may linger over far northern WI on Sunday night. Otherwise, winds will remain gusty through through the night, which may lead to some minor blowing and drifting of the new snow, particularly on north-south oriented highways. The colder air will trail the system, and push into the area on Monday. Highs will on rise into the low to mid teens. Although high pressure will build into the area on Monday night, a weak system will bring a chance of widespread light snow to the area on Tuesday and Tuesday night. Some accumulations appear possible, perhaps an inch or two. The flow will remain out of the northwest for the rest of the week, which will keep temps below normal. && .AVIATION...for 18Z TAF Issuance Issued at 1123 AM CST Thu Feb 21 2019 Outside of a few flurries, fairly quiet weather expected through the short-term portion of the forecast. The biggest concern will be low to mid cloud potential through tonight. VFR/MVFR conditions are noted at most TAF sites this morning; however, RHI has been generally staying around 1500 ft ceilings. That patch of clouds extends farther west int northwest WI, so the ceilings will likely linger for a good portion of the afternoon. CWA and AUW could end up seeing some MVFR ceilings at times, as there are some lower clouds upstream, but they have had trouble advancing very far east this morning. The rest of the TAF sites will likely remain VFR. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....Cooley LONG TERM......MPC AVIATION.......Cooley