Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/10/13


AREA FORECAST DISCUSSION
NWS NEW YORK NY
952 PM EDT WED OCT 9 2013 .SYNOPSIS... LOW PRESSURE OFF OF CAPE HATTERAS WILL DRIFT UP THE COAST AND SPREAD MOISTURE INTO THE AREA THROUGH THURSDAY. THE LOW WILL CONTINUE UP THE COAST FRIDAY AND MEANDER OFFSHORE THIS WEEKEND. HIGH PRESSURE WILL BUILD SOUTH FROM THE CANADIAN MARITIMES LATE IN THE WEEKEND THROUGH TUESDAY. A COLD FRONT WILL APPROACH ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 18Z MODEL RUNS MUCH CLOSER TO CURRENT CONDITIONS AS 1010 MB LOW REMAIN JUST SE OF CAPE HAT WITH 1030 MB HIGH PRES TO THE NORTH. RAIN STILL OVER THE DELMARVA...WITH ONLY A FEW SPRINKLES OVER EXTREME SRN NJ AS ENOUGH DRY AIR REMAINS IN PLACE THERE. FOR OUR AREA MAINLY HIGH CLOUDS OVER THE AREA WITH WATER VAPOR INDICATING A SUBTROPICAL TAP. OKX SOUNDING SHOWS PLENTY OF DRY AIR TO OVERCOME IN THE LOW TO MID LEVELS. DRY WEATHER THRU AT LEAST MIDNIGHT...THEN WE START GETTING INTO SOME LIGHT RAIN OR SPRINKLE CHANCES AROUND SUNRISE. HRRR SUGGESTING RAIN BANDS HEADING TOWARD THE COAST BY SUNRISE. NE WINDS CONTINUE WITH GUSTS TO AROUND 20 MPH...ESPECIALLY N SHORE OF LI INTO NRN QUEENS WITH THE FUNNELING EFFECT DOWN THE SOUND. LATE EVENING UPDATE TO TEMPS AS READINGS WERE SLIGHTLY COOLER THAN FCST. OTHERWISE FCST IS ON TRACK. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... MID LVL FROGEN SPREADS NWD INTO THE REGION HELPING TO FOCUS RAIN INTO THE CWA FROM LATE MRNG THRU THE AFTN HOURS. ALTHOUGH THERE COULD BE SOME SUBTLE CHANGES TO THIS TIMING...WIDESPREAD MDT RAIN...WITH POCKETS OF HEAVIER RAIN...CAN BE EXPECTED THRU THE DAY. THE RAIN CONTINUES THU NGT AS H85 MOISTURE TRANSPORT PERSISTS FROM THE OCEAN. NE WINDS WILL REMAIN LOCKED IN THRU THE PERIOD WITH THE TIGHT PRES GRADIENT OVER THE AREA. STRONGEST WINDS ALONG THE COASTS...ESPECIALLY THE N SHORE OF LI. PLEASE SEE TIDES SECTION FOR DETAILS ON CSTL FLOODING AND MINOR BEACH EROSION. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... MODELS CONTINUE IN GENERAL AGREEMENT WITH A CUTOFF LOW OVER THE SOUTHEAST STATES AND ASSOCIATED SURFACE LOW...DRIFTING NORTH UP THE EAST COAST THROUGH THE LATE WEEK AND THEN REMAINING OFF THE MID ATLANTIC COAST INTO EARLY NEXT WEEK. MEANWHILE STRONG HIGH PRESSURE ACROSS NEW ENGLAND AND THE CANADIAN MARITIMES WILL START TO BUILD DOWN OVER THE WEEKEND INTO EARLY NEXT WEEK. FOLLOWED ECMWF/GFS COMPROMISE FOR THE MOST PART...WITH A MODERATE RAINFALL CONTINUING INTO FRIDAY WITH COOL CONVEYOR BELT MOISTURE LOCKED IN OVER THE AREA VIA LOW LEVEL EASTERLY FLOW...WITH DECENT LIFT VIA H7-8 FRONTOGENESIS AND WEAK UPPER DIVERGENCE IN THE LEFT EXIT REGION OF AN OFFSHORE DIFLUENT H3 JET STREAK EAST OF THE CUTOFF LOW. UNCERTAINTY ON WHEN DRY WX RETURNS BEGINS TO CREEP INTO THE FCST THIS WEEKEND. MODELS AGREE THAT THE THE JET STREAK SHOULD MOVE EAST FRI NIGHT WHILE THE UPPER LOW BEGINS TO SLOWLY RETREAT SOUTH...PUTTING AN END TO STRONGEST LIFT...BUT WITH MOISTURE AND LOW LEVEL ONSHORE FLOW CONTINUING LIGHT RAIN SHOULD ALSO CONTINUE AT LEAST INTO SAT OR SAT NIGHT. ECMWF IS MOSTLY DRY BY SAT NIGHT OR SUNDAY....BUT WITH THE GFS SLOWER TO BEGIN THE SOUTHWARD DRIFT OF THE LOW AND TO BUILD IN THE HIGH TO THE NORTH...HELD ONTO SLIGHT CHANCE POP FOR SOUTHERN CT AND CHANCE POP ELSEWHERE FOR THE REST OF THE WEEKEND. MAINLY DRY CONDS MORE LIKELY TO ARRIVE SUNDAY NIGHT INTO MON NIGHT AS THE HIGH TO THE NORTH DOMINATES...AND INTO TUE AS THE HIGH WEAKENS AND BEGINS TO DRIFT E. WITH THE AXIS OF THE HIGH TO THE NORTH MAY STILL HOWEVER HAVE TO DEAL WITH CLOUDINESS FROM THE OFFSHORE LOW VIA MARITIME MOISTURE TRAPPED BENEATH A SUBSIDENCE INVERSION. AN APPROACHING COLD FRONT MAY BRING THE NEXT CHANCE OF SHOWERS ON WED. DAYTIME TEMPS SHOULD BE ON THE COOL SIDE ON FRI...MAINLY UPPER 50S AND LOWER 60S...WITH A SMALL DIURNAL SPREAD FOR FRI NIGHT AND LIKELY INTO THE WEEKEND AS PRECIP/CLOUDS DOMINATE. NEAR OR SLIGHTLY BELOW AVG TEMPS SHOULD CONTINUE INTO EARLY NEXT WEEK AS THE HIGH BUILDS... WITH SOMEWHAT COOLER NIGHTTIME TEMPS AS WELL. TEMPS MAY MODERATE TO NEAR OR SLIGHTLY ABOVE AVG BY WED AHEAD OF THE APPROACHING COLD FRONT. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... RAIN FROM A SLOWLY APPROACHING LOW OFF THE CAROLINA COAST ARRIVES FROM SOUTH TO NORTH OVERNIGHT INTO THURSDAY MORNING. THE RAIN CONTINUES THROUGH THE TAF PERIOD AS THE LOW FURTHER SLOWS DOWN. VFR WITH WINDS AROUND 10 KTS OR LESS THIS EVENING...INCREASING OVERNIGHT INTO THURSDAY AS CONDITIONS DETERIORATE TO MVFR WITH LOCALIZED IFR. GUSTS AROUND 20-25 KT WILL BE LIKELY FOR COASTAL TERMINALS THURSDAY. THERE WILL BE SOME LOCALLY HIGHER GUSTS. WIND DIRECTION WILL BE PRIMARILY OUT OF THE NORTHEAST THROUGH THE PERIOD. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: AMENDMENTS WILL BE LIKELY TO REFINE TIMING OF RAIN AND WIND GUSTS. THERE WILL LIKELY BE SOME FLUCTUATION BETWEEN VFR AND MVFR STARTING LATE TONIGHT. KJFK FCSTER COMMENTS: AMENDMENTS WILL BE LIKELY TO REFINE TIMING OF RAIN AND WIND GUSTS. THERE WILL LIKELY BE SOME FLUCTUATION BETWEEN VFR AND MVFR STARTING LATE TONIGHT. IFR WILL BE POSSIBLE AT TIMES STARTING THURSDAY MORNING. KLGA FCSTER COMMENTS: AMENDMENTS WILL BE LIKELY TO REFINE TIMING OF RAIN AND WIND GUSTS. THERE WILL LIKELY BE SOME FLUCTUATION BETWEEN VFR AND MVFR STARTING LATE TONIGHT. IFR WILL BE POSSIBLE AT TIMES STARTING THURSDAY MORNING. KTEB FCSTER COMMENTS: AMENDMENTS WILL BE LIKELY TO REFINE TIMING OF RAIN AND WIND GUSTS. THERE WILL LIKELY BE SOME FLUCTUATION BETWEEN VFR AND MVFR STARTING LATE TONIGHT. KHPN FCSTER COMMENTS: AMENDMENTS WILL BE LIKELY TO REFINE TIMING OF RAIN AND WIND GUSTS. THERE WILL LIKELY BE SOME FLUCTUATION BETWEEN VFR AND MVFR STARTING LATE TONIGHT. KISP FCSTER COMMENTS: AMENDMENTS WILL BE LIKELY TO REFINE TIMING OF RAIN AND WIND GUSTS. THERE WILL LIKELY BE SOME FLUCTUATION BETWEEN VFR AND MVFR STARTING LATE TONIGHT AND BETWEEN IFR AND MVFR ON THURSDAY. .OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY... .THU NIGHT-FRI NIGHT...IFR POSSIBLE IN -RA. PERSISTENT ENE FLOW. GUSTS UP TO 30 KT POSSIBLE ALONG THE COAST. .SAT-SUN...MAINLY VFR...THOUGH UNCERTAINTY ON HOW FAST THE COASTAL LOW WEAKENS AND MOVES OUT THIS WEEKEND. .MON...VFR. && .MARINE... NE FLOW CURRENTLY PRODUCING SCA CONDITIONS THRU THU NGT. SEAS BUILDING OVER THE WESTERN OCEAN WATERS QUICKER THAN WAVE WATCH FCST. 6 TO 10 FT SEAS LIKELY THROUGH THU AND THU NIGHT. AN EXTENDED PERIOD OF SCA CONDS WINDS AND SEAS IS EXPECTED TO CONTINUE THROUGH FRI-SAT ON ALL WATERS WIND GUSTS ON THE OCEAN MAY APPROACH MINIMAL GALE FORCE FRI INTO FRI NIGHT. PERSISTENT E FLOW SHOULD MAINTAIN SCA CONDS ON THE OCEAN SAT NIGHT INTO MON NIGHT...WITH WIND GUSTS UP TO 25 KT INTO SUNDAY EVENING... THEN RESIDUAL HAZARDOUS SEAS VIA EASTERLY SWELL. && .HYDROLOGY... A WIDESPREAD PROLONGED RAINFALL CAN BE EXPECTED THU-FRI. RAINFALL AMOUNTS OF AROUND 2 INCHES CAN BE EXPECTED WHERE THE HEAVIEST BAND SETS UP THRU THE PERIOD. A RAINFALL GRAPHIC HAS BEEN POSTED. && .TIDES/COASTAL FLOODING... A STRENGTHENING AND PERSISTENT NE FLOW THROUGH THE LATTER HALF OF THE WEEK WILL RESULT IN TIDAL PILING AND MINOR COASTAL FLOODING CONCERNS OVER SUCCESSIVE HIGH TIDE CYCLE. A LOWER ASTRONOMICAL HIGH TIDE TONIGHT SHOULD KEEP ANY FLOODING THREATS AT MINIMAL LEVELS. THE PERSISTENT NE FLOW...COMBINING WITH A HIGHER ASTRONOMICAL TIDE AND PERIODS OF HEAVY RAIN THURS AFTERNOON SHOULD RESULT IN A MORE WIDESPREAD MINOR COASTAL FLOODING EVENT...ESPECIALLY ALONG THE SOUTH SHORE BAYS OF LONG ISLAND AND THE WESTERN SOUND WHERE TIDAL DEPARTURES OF AROUND 1.5 FT ARE FORECASTED. IN ADDITION...VULNERABLE LOW LYING AREAS ALONG SUFFOLK COUNTY...NEW HAVEN...AND NEW YORK HARBOR MAY BE AFFECTED WHERE TIDAL DEPARTURES BETWEEN 1.0-1.5 FT ARE EXPECTED. HAVE THUS ISSUED A COASTAL FLOOD ADVISORY FOR THURSDAY AFTERNOON FOR THE COASTS ALONG THE SOUTH SHORE BAYS OF QUEENS...BROOKLYN...AND NASSAU COUNTY AS WELL AS THE WESTERN PORTION OF LONG ISLAND SOUND. WITH LOWER CONFIDENCE OF A MORE WIDESPREAD IMPACT...HAVE ISSUED A COASTAL FLOOD STATEMENT FOR THE REMAINDER OF THE AREA...EXCLUDING THE EASTERN HALF OF SUFFOLK COUNTY...AND NEW LONDON COUNTY. HOWEVER...ANY CHANGE IN THE PATH AND STRENGTH OF THE APPROACHING LOW RESULTING IN DIFFERING TIDAL DEPARTURES AND RAINFALL AMOUNTS COULD INCREASE THE THREAT...AND THUS THE ADVISORY MAY NEED TO BE EXTENDED. THE MINOR COASTAL FLOODING THREAT SHOULD BE MINIMAL ONCE AGAIN THURSDAY NIGHT...BUT MAY BE AN ISSUE ONCE AGAIN FOR FRIDAYS AFTERNOON TIDAL CYCLE. MINOR COASTAL FLOODING ISSUES COULD CONTINUE ALONG VULNERABLE BACK BAY LOCALES INTO THE WEEKEND. IN ADDITION...MINOR BEACH EROSION IS POSSIBLE DURING THE LATE WEEK/WEEKEND DUE TO A PROLONGED PERIOD OF HIGHER SURF WITH EASTERLY SWELLS. LOW LYING COASTAL AREAS ESPECIALLY OVER EASTERN SUFFOLK COUNTY MAY BE IMPACTED. && .EQUIPMENT... DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM. DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...COASTAL FLOOD ADVISORY FROM 3 PM TO 6 PM EDT THURSDAY FOR CTZ009. NY...COASTAL FLOOD ADVISORY FROM 3 PM TO 6 PM EDT THURSDAY FOR NYZ071-073-176-177. COASTAL FLOOD ADVISORY FROM 11 AM TO 2 PM EDT THURSDAY FOR NYZ075-178-179. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ330-335-338- 340-345-350-353-355. && $$ SYNOPSIS...JMC/GOODMAN NEAR TERM...JMC/GOODMAN/PW SHORT TERM...JMC LONG TERM...GOODMAN AVIATION...JM MARINE...JMC/GOODMAN/PW HYDROLOGY...JMC/GOODMAN TIDES/COASTAL FLOODING... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MIAMI FL
155 PM EDT TUE OCT 8 2013 .AVIATION... A PRE-FRONTAL TROUGH IS CURRENTLY PUSHING OF THE SOUTHEAST COAST. THIS HAS BROUGHT SHOWERS AND THUNDERSTORMS TO THE MIAMI DADE METRO AREAS THIS MORNING, INCLUDING SOME WATERSPOUTS. THIS WILL CONTINUE TO PUSH FURTHER TO SOUTHEAST THROUGH THE AFTERNOON AND EVENING. HAVE PULLED VCTS FROM TAFS AT THIS TIME AS MOST OF THE CONVECTIVE ACTIVITY BEHIND THE TROUGH CONSISTS OF SHOWERS. HOWEVER, THERE IS STILL A POSSIBILITY OF AN ISOLATED TSRA. BUT IT WOULD BE QUICK MOVING AND ONLY AFFECT AN AREAS FOR A BRIEF TIME, IF ANY DO DEVELOP. LATER TONIGHT, A COLD FRONT WILL SLIDE THROUGH, POSSIBLY STALLING SOMEWHERE OVER SOUTH FLORIDA. CURRENTLY, THINKING THIS FRONT WILL BE FAIRLY BENIGN WEATHER WISE, JUST CAUSING A WIND SHIFT AND LOWER HUMIDITY. && .PREV DISCUSSION... /ISSUED 903 AM EDT TUE OCT 8 2013/ UPDATE... LOW PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL MOVE SLOWLY EAST PUSHING A COLD FRONT OVER NORTH FLORIDA SOUTHWARD INTO CENTRAL FLORIDA. THIS WILL KEEP THE WIND FLOW OVER SOUTH FLORIDA IN A SOUTHWEST TO WEST DIRECTION OVER THE SOUTH FLORIDA TODAY. A PRE-FRONTAL TROUGH OF LOW PRESSURE FROM ABOUT WEST PALM BEACH SOUTHWEST TO NAPLES WILL ALSO MOVE SOUTHWARD THROUGH SOUTH FLORIDA TODAY. THIS PRE-FRONTAL TROUGH WILL BRING IN SOME DRIER AIR TO THE AREA FROM THE NORTH THROUGH TODAY. SO THE PWAT VALUES OVER THE NORTHERN AREAS WILL BE FALLING FROM AROUND 1.6 INCHES THIS MORNING TO AROUND 1 INCH BY THIS EVENING...AND FROM AROUND 2 INCHES THIS MORNING TO 1.5 INCHES BY THIS EVENING OVER THE SOUTHERN AREAS. THEREFORE...THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE OVER THE SOUTHEAST AREAS OF SOUTH FLORIDA THIS AFTERNOON. THE 500 MB TEMP FROM THE MORNING MIA SOUNDING WAS ALSO SHOWING -4 TO -5 CELSIUS. THIS WILL KEEP THE THREAT OF THUNDERSTORMS LOW OVER THE SOUTHERN AREAS OF SOUTH FLORIDA TODAY DUE TO THE WARM MID LEVELS OF THE ATMOSPHERE. SO THE POPS WILL REMAIN IN THE SLIGHT CHANCE ACROSS SOUTH FLORIDA TODAY EXCEPT LOW END CHANCE OVER THE SOUTHEAST AREAS. THE THUNDER WORDING WILL ALSO BE REMOVED FROM MOST OF SOUTH FLORIDA...EXCEPT FOR THE SOUTHEAST AREAS WHERE A SLIGHT CHANCE WILL REMAIN IN PLACE. REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES ARE PLANNED. UPDATED...54/BNB PREV DISCUSSION... /ISSUED 338 AM EDT TUE OCT 8 2013/ DISCUSSION... MID LEVEL TROUGH CURRENTLY LOCATED OVER NORTH FLORIDA WITH A SURFACE LOW PRESSURE JUST SOUTH OF JAX AND ITS TRAILING COLD FRONT EXTENDING TO THE SOUTHWEST INTO THE GULF OF MEXICO. AS THE TROUGH CONTINUES TO LIFT NORTHEAST, WEAK RIDGING WILL BUILD BEHIND IT WITH MUCH DRIER ALOFT MOVING ACROSS SOUTH FLORIDA. THIS WILL CONTINUE A DEEP SOUTHWESTERLY FLOW ACROSS THE REGION THROUGH THE DAY. AS THE DRIER AIR BEGINS TO FILTER INTO THE AREA, FORECAST SOUNDINGS FROM THE NAM, GFS AND ECMWF ALL SHOW PWAT DROPPING TO 1.5 INCHES OR LESS BY 00Z THIS EVENING. HOWEVER, THE PWAT IS FORECAST TO BE IN THE RANGE OF 1.8-1.9 INCHES THIS MORNING. THEREFORE, THE MEDIUM RANGE AND SHORT TERM HIGH RESOLUTION MODELS HAVE HUGE DIFFERENCES ON RAINFALL COVERAGE FOR TODAY. THE NAM SHOWS VIRTUALLY NOTHING WHILE THE HRRR DEPICTS SCATTERED COVERAGE DEVELOPING AFTER 15Z OVER THE SOUTHERN PORTIONS AND SPREADING TOWARDS THE EAST COAST INTO THE EARLY AFTERNOON. ALL OF THIS CONSIDERED, IT WOULD APPEAR THAT THE BEST CHANCE FOR CONVECTIVE ACTIVITY WILL BE OVER THE SOUTHEAST METRO AREAS AND HAVE THUS DEPICTED THIS IN THE GRIDS. BY WEDNESDAY, THE TROUGH WILL CONTINUE TO LIFT NORTHEAST WITH A RIDGE BUILDING ACROSS THE SOUTHEAST STATES. THIS WILL CONTINUE TO FILTER DRIER AIR INTO SOUTH FLORIDA WITH LOW CHANCES FOR SEEING SHOWERS ON WEDNESDAY AND NO ACTIVITY FROM THURSDAY INTO THE WEEKEND AND EARLY NEXT WEEK. MARINE... WIND AND SEAS WILL REMAIN RATHER TRANQUIL THROUGH THE FORECAST WITH A SOUTHWEST WIND OF LESS THAN 15 KNOTS TODAY BECOMING NORTHEAST AT AROUND 10 KNOTS LATER IN THE WEEK INTO THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 70 87 74 87 / 10 20 10 10 FORT LAUDERDALE 72 87 77 86 / 20 30 10 10 MIAMI 72 88 77 88 / 20 30 20 10 NAPLES 74 87 74 87 / 10 20 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...54/BNB AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
955 AM EDT TUE OCT 8 2013 .DISCUSSION... CURRENT...WEAK LOW PRES CENTER HAS PUSHED OFFSHORE NE FL AND NOW SITS EAST OF KXFL/SOUTH OF 41012 AS IT CONTINUES TO SLIDE EWD. DIFFUSE LEADING EDGE OF WEAK COOL FRONT APPEARS TO BE N/W OF BOTH THE 09Z AND 12Z HPC-ADVERTISED POSITIONS. AS OF 13Z IT LOOKS TO EXTEND PRETTY MUCH DUE WWD FROM THE LOW CENTER ACROSS THE SRN EDGE OF THE JAX CWA. SOUTH OF THE FRONT...BKN TO OVC LOW CLOUD DECK PLAGUING THE NRN THIRD CWA...FROM ABOUT KMCO-KTIX NWD WITH A FEW SCRAPS OF STFRA FARTHER SOUTH ACROSS OSCEOLA/BREVARD COS. LOOKING ALOFT...WATER VAPOR IMAGERY AND RUC ANLYS FIELDS SHOW MID LEVEL TROUGH AXIS EXTENDING FROM THE XTRM NE GOMEX ACROSS NORTH FL AND UP THROUGH THE CAROLINAS. FEATURE IS COLOCATED WITH STRONG AND RATHER NARROW H25 JET STREAK OF 70-80KT AND DEFORMATION ZONE. MORNING RAOB DATA CLEARLY SHOWS THE MID LEVEL DRY TONGUE OVER THE CENTRAL CWA WITH MUCH LOWER RH VALUES AOA H70 AT TBW/MLB COMPARED TO JAX. CONSEQUENTLY...MEAN PWATS (1.4" TO 1.5") ARE SEVERAL TENTHS LOWER THAN THOSE TO THE NORTH. REMAINDER OF TODAY/TONIGHT...SFC LOW AND PARENT H50 TROUGH WILL LIFT OUT TO THE ENE IN TANDEM. MESOSCALE MODEL GUIDANCE (12KM NAM/3-9KM LOCALLY RUN WRF) SHOW WRAPAROUND MOISTURE NEAR WEAK FRONTAL BOUNDARY GETTING DRAGGED SE ACROSS THE CWA AS THE SFC AND UPPER FEATURES PULL AWAY. THIS SHOULD RESULT IN AN INCREASE IN MEAN MOISTURE THROUGH THE DAY...WITH RAIN CHANCES IN LOW END SCATTERED RANGE. PLAN TO GO WITH POPS TO ABOUT 30 AREAWIDE...WHICH MEANS TWEAKING NUMBERS ACROSS THE NORTHERN CWA DOWN BY 10 PCT...AND UP 10 OVER THE SE. WILL GO WITH A SMALL CHANCE FOR A LINGERING EARLY EVENING SHOWER ACROSS THE SERN CWA COINCIDENT WITH POSITION OF WRAPAROUND MOISTURE BAND. && .AVIATION...STILL DEALING WITH A FEW SCRAPS OF PESKY BKN IFR ST/STFRA NORTH OF ISM-MCO-TIX...BUT IT APPEARS THE BKN006-009 CIGS WILL LIFT INTO THE BKN-OVC010-020 RANGE STARTING A LITTLE AFTER 14Z. MVFR CIGS SHOULD GRADUALLY RISE TO VFR BY 17Z-18Z. && .MARINE...OFFSHORE FLOW WITH SEAS 2-3FT NEAR SHORE AND W-4FT WELL OFFSHORE && FORECAST/AVIATION...CRISTALDI RADAR/IMPACT WX....SPRATT && .PREV DISCUSSION... /ISSUED 333 AM EDT TUE OCT 8 2013/ WED...SFC LOW PRESSURE OFF THE NE FL COAST WILL ALLOW A DRY NNW LOW LVL FLOW ACROSS MUCH OF EAST CENTRAL FL EXCEPT FAR SRN SECTIONS WHERE ENOUGH LOW-MID LVL MOISTURE MAY ALLOW FOR ISOLATED AFTERNOON SHOWERS ACROSS PORTIONS OF MARTIN AND ST LUCE COUNTIES. HIGH TEMPS WILL RANGE FROM THE MID 80S ACROSS THE NORTH TO UPPER 80S TO NEAR 90 ACROSS INLAND SECTIONS OF THE TREASURE COAST AND OKEECHOBEE COUNTY. WED NIGHT...SFC LOW WILL REMAIN OFFSHORE AND APPEARS ISOLD SHOWERS ACROSS THE ATLANTIC WATERS NORTH OF THE CAPE SHOULD REMAIN JUST OFFSHORE. SKIES WILL BE MOSTLY CLEAR TO PARTLY CLOUDY WITH LOW TEMPERATURES IN THE MID-UPPER 60S. THU...GFS INDICATES LOW PRESSURE THAT WAS THE REMAINS OF KAREN WILL PULL A BIT FURTHER OFFSHORE WITH CONTINUED NORTHERLY SFC WINDS. A MID LVL SHORTWAVE TROUGH SHOULD INDUCE SECONDARY LOW PRESSURE DEVELOPMENT OFF THE MID ATLC. ENOUGH NNE LOW LVL NORTH OF THE CAPE TO ENTERTAIN SOME LOW COASTAL POPS NORTH OF CAPE CANAVERAL WITH THE SLIGHT CHANCE FOR ATLC SHOWERS MOVING ONSHORE. WILL KEEP INTERIOR AND SRN SECTIONS DRY WITH HIGHS IN THE LWR-MID 80 N CSTL TO UPPER 80S SRN INTERIOR. FRI...00Z GFS CONTINUES TREND TWD VEERING LOW LVL FLOW FROM N TO NE THROUGH THE DAY WITH RELATIVELY LOW MOISTURE LEVELS. MOS POPS BELOW 5 PERCENT LOOK OPTIMISTIC WITH NE FLOW TO 10-15 KNOTS OVER THE WARM ATLC AND SOME LOW LVL MOISTURE. COULD BE A FEW SHOWERS MOVING ONSHORE ESPECIALLY FROM THE CAPE SOUTH BUT FOR NOW WILL CAP LAND POPS AROUND 10 PCT AND KEEP SLGT SHOWER CHCS ACROSS THE ATLC WATERS. HIGHS LWR-MID 80S IMMEDIATE COAST TO MID-UPPER 80S FOR THE INTERIOR. SAT-TUE...00Z GFS INDICATES MID LVL S/W TROUGH OFF THE MID ATLC COAST WILL ALLOW A SFC LOW PRESSURE AREA TO MOVE SOUTH OFF THE CAROLINA COAST BY EARLY NEXT WEEK. THIS WILL KEEP E CENTRAL FL IN A LOW LVL NE FLOW PATTERN WITH A RELATIVELY DRY AIRMASS ACROSS THE AREA FOR SATURDAY INTO SUNDAY BEFORE SOME ATLC MOISTURE WORK DOWN BEHIND THE LOW TWD THE AREA BY EARLY NEXT WEEK. FOR NOW WILL KEEP WEEKEND DRY WITH SOME LOW POPS MONDAY INTO TUESDAY OF NEXT WEEK. HIGHS WILL MAINLY BE IN THE LOWER TO MID 80S WITH WARMER TEMPS OVER THE INTERIOR AND COOLER ALONG N CSTL. LOWS IN THE MID 60S INTERIOR TO UPPER 60S TO AROUND 70 ALONG THE COAST. && .AVIATION...PREVAILING MVFR TEMPO IFR/LIFR 09Z TO 14Z AS WRAP AROUND MOISTURE AND SOUTHWEST WIND CONDUCIVE TO LATE NIGHT STRATUS AND STRATOCU. VFR 14Z TO 02Z WITH TEMPOS MVFR CEILINGS AND VISIBILITIES DUE TO SHOWERS AND STORMS. PREVAILING MVFR WITH TEMPO IFR CEILINGS IN THE EVENING AND TEMPO LIFR CONDITIONS AFTER 06Z DUE TO LOW CLOUDS COMING OFF THE OCEAN AND MOVING INLAND. && .MARINE... TODAY-TONIGHT...BUOYS WERE RECORDING SOUTH TO SOUTHWEST WINDS AROUND 10 KNOTS AND 2 TO 3 FOOT SEAS. WINDS SOUTHWEST LESS THAN 15 KNOTS DURING THE DAY. WINDS SHIFT TO THE WEST AND NORTHWEST 10 KNOTS DURING THE EVENING AS THE SURFACE BOUNDARY MOVES NORTH TO SOUTH OVER THE COASTAL WATERS. NORTH WINDS AROUND 10 KNOTS AFTER MIDNIGHT AS HIGH PRESSURE BUILDS OVER THE COASTAL WATERS. WED...WINDS WILL REACH SCEC LEVELS ACROSS CENTRAL/NRN MARINE ZONES WED INTO THU WITH STRONGER PRESSURE GRADIENT ON THE BACK SIDE OF THE LOW PRESSURE AREA OFFSHORE FROM THE NE FL COAST. WINDS WILL BECOME N/NE LATE THIS WEEK TO NEAR 15 KNOTS OFFSHORE... WHICH SHOULD ALLOW FOR SCEC CONDITIONS IN THE GULF STREAM INTO LATE WEEK. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
903 AM EDT TUE OCT 8 2013 .UPDATE... LOW PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL MOVE SLOWLY EAST PUSHING A COLD FRONT OVER NORTH FLORIDA SOUTHWARD INTO CENTRAL FLORIDA. THIS WILL KEEP THE WIND FLOW OVER SOUTH FLORIDA IN A SOUTHWEST TO WEST DIRECTION OVER THE SOUTH FLORIDA TODAY. A PRE-FRONTAL TROUGH OF LOW PRESSURE FROM ABOUT WEST PALM BEACH SOUTHWEST TO NAPLES WILL ALSO MOVE SOUTHWARD THROUGH SOUTH FLORIDA TODAY. THIS PRE-FRONTAL TROUGH WILL BRING IN SOME DRIER AIR TO THE AREA FROM THE NORTH THROUGH TODAY. SO THE PWAT VALUES OVER THE NORTHERN AREAS WILL BE FALLING FROM AROUND 1.6 INCHES THIS MORNING TO AROUND 1 INCH BY THIS EVENING...AND FROM AROUND 2 INCHES THIS MORNING TO 1.5 INCHES BY THIS EVENING OVER THE SOUTHERN AREAS. THEREFORE...THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE OVER THE SOUTHEAST AREAS OF SOUTH FLORIDA THIS AFTERNOON. THE 500 MB TEMP FROM THE MORNING MIA SOUNDING WAS ALSO SHOWING -4 TO -5 CELSIUS. THIS WILL KEEP THE THREAT OF THUNDERSTORMS LOW OVER THE SOUTHERN AREAS OF SOUTH FLORIDA TODAY DUE TO THE WARM MID LEVELS OF THE ATMOSPHERE. SO THE POPS WILL REMAIN IN THE SLIGHT CHANCE ACROSS SOUTH FLORIDA TODAY EXCEPT LOW END CHANCE OVER THE SOUTHEAST AREAS. THE THUNDER WORDING WILL ALSO BE REMOVED FROM MOST OF SOUTH FLORIDA...EXCEPT FOR THE SOUTHEAST AREAS WHERE A SLIGHT CHANCE WILL REMAIN IN PLACE. REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES ARE PLANNED. && .UPDATED...54/BNB .PREV DISCUSSION... /ISSUED 631 AM EDT TUE OCT 8 2013/ AVIATION... DRIER AIR IN THE WAKE OF A FRONTAL BOUNDARY WILL BEGIN TO SPREAD SOUTH INTO THE LOCAL AREA TODAY. WINDS WILL REMAIN OUT OF THE WEST AND INCREASE TO AROUND 10 KT WITH A FEW MODERATE GUSTS THROUGH THE LATE MORNING/AFTERNOON HOURS. THE BEST CHANCE OF SHRA/TSTMS WILL REMAIN ACROSS THE SOUTHEAST FLORIDA PENINSULA...MAINLY FROM FLL TO MIA/TMB. AS A RESULT...VCTS WILL BE INCLUDED IN THIS PACKAGE FOR THESE TERMINALS THROUGH THE AFTERNOON PERIOD. OTHERWISE...VFR CONDITIONS ARE ANTICIPATED. WINDS WILL GRADUALLY BEGIN TO SHIFT TO THE NORTH BY THE END OF THE PERIOD AND INTO WEDNESDAY. && PREV DISCUSSION... /ISSUED 338 AM EDT TUE OCT 8 2013/ DISCUSSION... MID LEVEL TROUGH CURRENTLY LOCATED OVER NORTH FLORIDA WITH A SURFACE LOW PRESSURE JUST SOUTH OF JAX AND ITS TRAILING COLD FRONT EXTENDING TO THE SOUTHWEST INTO THE GULF OF MEXICO. AS THE TROUGH CONTINUES TO LIFT NORTHEAST, WEAK RIDGING WILL BUILD BEHIND IT WITH MUCH DRIER ALOFT MOVING ACROSS SOUTH FLORIDA. THIS WILL CONTINUE A DEEP SOUTHWESTERLY FLOW ACROSS THE REGION THROUGH THE DAY. AS THE DRIER AIR BEGINS TO FILTER INTO THE AREA, FORECAST SOUNDINGS FROM THE NAM, GFS AND ECMWF ALL SHOW PWAT DROPPING TO 1.5 INCHES OR LESS BY 00Z THIS EVENING. HOWEVER, THE PWAT IS FORECAST TO BE IN THE RANGE OF 1.8-1.9 INCHES THIS MORNING. THEREFORE, THE MEDIUM RANGE AND SHORT TERM HIGH RESOLUTION MODELS HAVE HUGE DIFFERENCES ON RAINFALL COVERAGE FOR TODAY. THE NAM SHOWS VIRTUALLY NOTHING WHILE THE HRRR DEPICTS SCATTERED COVERAGE DEVELOPING AFTER 15Z OVER THE SOUTHERN PORTIONS AND SPREADING TOWARDS THE EAST COAST INTO THE EARLY AFTERNOON. ALL OF THIS CONSIDERED, IT WOULD APPEAR THAT THE BEST CHANCE FOR CONVECTIVE ACTIVITY WILL BE OVER THE SOUTHEAST METRO AREAS AND HAVE THUS DEPICTED THIS IN THE GRIDS. BY WEDNESDAY, THE TROUGH WILL CONTINUE TO LIFT NORTHEAST WITH A RIDGE BUILDING ACROSS THE SOUTHEAST STATES. THIS WILL CONTINUE TO FILTER DRIER AIR INTO SOUTH FLORIDA WITH LOW CHANCES FOR SEEING SHOWERS ON WEDNESDAY AND NO ACTIVITY FROM THURSDAY INTO THE WEEKEND AND EARLY NEXT WEEK. MARINE... WIND AND SEAS WILL REMAIN RATHER TRANQUIL THROUGH THE FORECAST WITH A SOUTHWEST WIND OF LESS THAN 15 KNOTS TODAY BECOMING NORTHEAST AT AROUND 10 KNOTS LATER IN THE WEEK INTO THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 91 70 87 74 / 20 10 20 10 FORT LAUDERDALE 90 72 87 77 / 30 20 30 10 MIAMI 91 72 88 77 / 30 20 30 20 NAPLES 87 74 87 74 / 10 10 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
631 AM EDT TUE OCT 8 2013 .AVIATION... DRIER AIR IN THE WAKE OF A FRONTAL BOUNDARY WILL BEGIN TO SPREAD SOUTH INTO THE LOCAL AREA TODAY. WINDS WILL REMAIN OUT OF THE WEST AND INCREASE TO AROUND 10 KT WITH A FEW MODERATE GUSTS THROUGH THE LATE MORNING/AFTERNOON HOURS. THE BEST CHANCE OF SHRA/TSTMS WILL REMAIN ACROSS THE SOUTHEAST FLORIDA PENINSULA...MAINLY FROM FLL TO MIA/TMB. AS A RESULT...VCTS WILL BE INCLUDED IN THIS PACKAGE FOR THESE TERMINALS THROUGH THE AFTERNOON PERIOD. OTHERWISE...VFR CONDITIONS ARE ANTICIPATED. WINDS WILL GRADUALLY BEGIN TO SHIFT TO THE NORTH BY THE END OF THE PERIOD AND INTO WEDNESDAY. && .PREV DISCUSSION... /ISSUED 338 AM EDT TUE OCT 8 2013/ DISCUSSION... MID LEVEL TROUGH CURRENTLY LOCATED OVER NORTH FLORIDA WITH A SURFACE LOW PRESSURE JUST SOUTH OF JAX AND ITS TRAILING COLD FRONT EXTENDING TO THE SOUTHWEST INTO THE GULF OF MEXICO. AS THE TROUGH CONTINUES TO LIFT NORTHEAST, WEAK RIDGING WILL BUILD BEHIND IT WITH MUCH DRIER ALOFT MOVING ACROSS SOUTH FLORIDA. THIS WILL CONTINUE A DEEP SOUTHWESTERLY FLOW ACROSS THE REGION THROUGH THE DAY. AS THE DRIER AIR BEGINS TO FILTER INTO THE AREA, FORECAST SOUNDINGS FROM THE NAM, GFS AND ECMWF ALL SHOW PWAT DROPPING TO 1.5 INCHES OR LESS BY 00Z THIS EVENING. HOWEVER, THE PWAT IS FORECAST TO BE IN THE RANGE OF 1.8-1.9 INCHES THIS MORNING. THEREFORE, THE MEDIUM RANGE AND SHORT TERM HIGH RESOLUTION MODELS HAVE HUGE DIFFERENCES ON RAINFALL COVERAGE FOR TODAY. THE NAM SHOWS VIRTUALLY NOTHING WHILE THE HRRR DEPICTS SCATTERED COVERAGE DEVELOPING AFTER 15Z OVER THE SOUTHERN PORTIONS AND SPREADING TOWARDS THE EAST COAST INTO THE EARLY AFTERNOON. ALL OF THIS CONSIDERED, IT WOULD APPEAR THAT THE BEST CHANCE FOR CONVECTIVE ACTIVITY WILL BE OVER THE SOUTHEAST METRO AREAS AND HAVE THUS DEPICTED THIS IN THE GRIDS. BY WEDNESDAY, THE TROUGH WILL CONTINUE TO LIFT NORTHEAST WITH A RIDGE BUILDING ACROSS THE SOUTHEAST STATES. THIS WILL CONTINUE TO FILTER DRIER AIR INTO SOUTH FLORIDA WITH LOW CHANCES FOR SEEING SHOWERS ON WEDNESDAY AND NO ACTIVITY FROM THURSDAY INTO THE WEEKEND AND EARLY NEXT WEEK. MARINE... WIND AND SEAS WILL REMAIN RATHER TRANQUIL THROUGH THE FORECAST WITH A SOUTHWEST WIND OF LESS THAN 15 KNOTS TODAY BECOMING NORTHEAST AT AROUND 10 KNOTS LATER IN THE WEEK INTO THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 89 70 87 74 / 20 10 20 10 FORT LAUDERDALE 88 72 87 77 / 30 20 30 10 MIAMI 89 72 88 77 / 30 20 30 20 NAPLES 85 74 87 74 / 20 10 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
338 AM EDT TUE OCT 8 2013 .DISCUSSION... MID LEVEL TROUGH CURRENTLY LOCATED OVER NORTH FLORIDA WITH A SURFACE LOW PRESSURE JUST SOUTH OF JAX AND ITS TRAILING COLD FRONT EXTENDING TO THE SOUTHWEST INTO THE GULF OF MEXICO. AS THE TROUGH CONTINUES TO LIFT NORTHEAST, WEAK RIDGING WILL BUILD BEHIND IT WITH MUCH DRIER ALOFT MOVING ACROSS SOUTH FLORIDA. THIS WILL CONTINUE A DEEP SOUTHWESTERLY FLOW ACROSS THE REGION THROUGH THE DAY. AS THE DRIER AIR BEGINS TO FILTER INTO THE AREA, FORECAST SOUNDINGS FROM THE NAM, GFS AND ECMWF ALL SHOW PWAT DROPPING TO 1.5 INCHES OR LESS BY 00Z THIS EVENING. HOWEVER, THE PWAT IS FORECAST TO BE IN THE RANGE OF 1.8-1.9 INCHES THIS MORNING. THEREFORE, THE MEDIUM RANGE AND SHORT TERM HIGH RESOLUTION MODELS HAVE HUGE DIFFERENCES ON RAINFALL COVERAGE FOR TODAY. THE NAM SHOWS VIRTUALLY NOTHING WHILE THE HRRR DEPICTS SCATTERED COVERAGE DEVELOPING AFTER 15Z OVER THE SOUTHERN PORTIONS AND SPREADING TOWARDS THE EAST COAST INTO THE EARLY AFTERNOON. ALL OF THIS CONSIDERED, IT WOULD APPEAR THAT THE BEST CHANCE FOR CONVECTIVE ACTIVITY WILL BE OVER THE SOUTHEAST METRO AREAS AND HAVE THUS DEPICTED THIS IN THE GRIDS. BY WEDNESDAY, THE TROUGH WILL CONTINUE TO LIFT NORTHEAST WITH A RIDGE BUILDING ACROSS THE SOUTHEAST STATES. THIS WILL CONTINUE TO FILTER DRIER AIR INTO SOUTH FLORIDA WITH LOW CHANCES FOR SEEING SHOWERS ON WEDNESDAY AND NO ACTIVITY FROM THURSDAY INTO THE WEEKEND AND EARLY NEXT WEEK. && .MARINE... WIND AND SEAS WILL REMAIN RATHER TRANQUIL THROUGH THE FORECAST WITH A SOUTHWEST WIND OF LESS THAN 15 KNOTS TODAY BECOMING NORTHEAST AT AROUND 10 KNOTS LATER IN THE WEEK INTO THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 89 70 87 74 / 20 10 20 10 FORT LAUDERDALE 88 72 87 77 / 30 20 30 10 MIAMI 89 72 88 77 / 30 20 30 20 NAPLES 87 74 87 74 / 20 10 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
313 AM EDT TUE OCT 8 2013 .SHORT TERM (TODAY-THURSDAY)... U/L PATTERN WILL BEGIN WITH A WEAK AREA OF LOW PRESSURE OVER THE SOUTHEAST U.S. CUT-OFF FROM THE MAIN U/L FLOW. DIGGING SHORTWAVE OVER THE WESTERN U.S. WILL INDUCE RIDGING THROUGH THE MISSISSIPPI RIVER VALLEY AND GREAT LAKES TODAY. STRONG CUT-OFF LOW WILL DEVELOP OVER THE SOUTHWEST U.S. WEDNESDAY WHICH WILL CONTINUE TO PUMP UP THE RIDGE OVER THE EASTERN U.S. WITH THE MAIN U/L FLOW PUSHED NORTH INTO SOUTHEAST CANADA. WEAK U/L LOW WILL PERSIST OVER THE MID ATLANTIC STAGES TRAPPED UNDER THE STRONG RIDGE. THE STRONG DISTURBANCE OVER SOUTHWEST U.S. WILL LIFT NORTHEAST TOWARD THE CENTRAL PLAINS THURSDAY WHICH WILL HELP EJECT THE WEAK LOW OVER THE MID ATLANTIC... WITH AN U/L RIDGE DEVELOPING OVER THE GULF OF MEXICO. AT THE SURFACE...AREA OF LOW PRESSURE WILL MOVE OFF THE NORTHEAST COAST OF FLORIDA TODAY WITH A FEW RAP AROUND SHOWERS PERSISTING ACROSS WEST CENTRAL FLORIDA THROUGH THIS AFTERNOON. SLIGHTLY DRIER COOLER AIR WILL FILTER DOWN THE BACKSIDE OF THE LOW OVER FLORIDA WEDNESDAY AND THURSDAY AS THE AREA OF LOW PRESSURE GRADUALLY WEAKENS OFF THE SOUTHEAST U.S. COAST AND SURFACE HIGH PRESSURE BUILDS DOWN THE EASTERN SEABOARD AND FLORIDA. TEMPERATURES WILL RUN NEAR TO A COUPLE DEGREES ABOVE CLIMATOLOGICAL NORMALS THROUGH THURSDAY. .LONG TERM (THURSDAY NIGHT-MONDAY)... CONDITIONS SHOULD BE FAIRLY BENIGN FOR THE END OF THIS WEEK AND THROUGH THE WEEKEND. AN UPPER LEVEL RIDGE FROM THE GULF OF MEXICO WILL START TO BUILD OVER THE AREA AT THE START OF THE LONG TERM PERIOD AS A LOW BEGINS TO CUT OFF ALONG THE EASTERN SEABOARD. SURFACE HIGH PRESSURE WILL ALSO BE IN PLACE ACROSS MUCH OF THE EASTERN PART OF THE COUNTRY. PLENTY OF DRY AIR WILL BE IN PLACE WITH SURFACE AND UPPER LEVEL HIGH PRESSURE OVER THE AREA AND THIS WILL KEEP RAIN CHANCES LOW THROUGH THE END OF THE WEEK AND INTO NEXT WEEK. && .AVIATION... MAINLY VFR CONDITIONS ARE EXPECTED WITH SOME BRIEF MVFR CEILINGS POSSIBLE EARLY THIS MORNING. && .MARINE... SEAS OF 3 TO 4 FEET WILL GRADUALLY SUBSIDE TONIGHT AND WEDNESDAY AS BOUNDARY LAYER WINDS WEAKEN AND BECOME INCREASINGLY OFFSHORE. SEAS WILL BE LESS THAN 4 FEET WITH WINDS LESS THAN 15 KNOTS FROM WEDNESDAY THROUGH THE WEEKEND WITH NO HAZARDS EXPECTED. && .FIRE WEATHER... NO FIRE WEATHER HAZARDS EXPECTED THROUGH THE PERIOD. RELATIVE HUMIDITY VALUES WILL REMAIN ABOVE CRITICAL LEVELS EACH AFTERNOON THROUGH THE REMAINDER OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 87 70 88 70 / 20 10 10 10 FMY 88 71 89 70 / 20 10 10 10 GIF 89 69 89 67 / 20 10 10 10 SRQ 86 71 87 69 / 20 10 10 10 BKV 88 66 86 62 / 20 10 10 10 SPG 87 75 87 73 / 20 10 10 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...RIP CURRENT RISK FROM 8 AM EDT THIS MORNING THROUGH THIS EVENING FOR CHARLOTTE-HILLSBOROUGH-LEE-MANATEE- PINELLAS-SARASOTA. GULF WATERS...NONE. && $$ SHORT TERM/MARINE/FIRE WEATHER...13/OGLESBY LONG TERM/AVIATION...05/CARLISLE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
816 PM MDT WED OCT 9 2013 .UPDATE... ISSUED AT 806 PM MDT WED OCT 9 2013 UPDATED FORECAST TO INCLUDE A WIND ADVISORY ACROSS ROUGHLY THE SOUTHEAST 2/3 OF THE FORECAST AREA FROM MID DAY THROUGH THE EVENING HOURS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 149 PM MDT WED OCT 9 2013 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW LARGE SCALE TROUGH ACROSS WESTERN CONUS WITH CLOSED 548DM H5 CENTER OVER WESTCENTRAL CALIFORNIA. 135KT H3 JET IS ROUNDING WESTERN EXTENT OF THIS TROUGH WITH WELL DEFINED PV HEIGHT ANOMALY OVER SOUTHERN CALIFORNIA. SW FLOW AHEAD OF THIS FEATURE IS IN PLACE ACROSS THE PLAINS. AT THE SURFACE A STATIONARY FRONT IS CURRENTLY EXTENDING FORM THE NORTHERN PLAINS ACROSS CENTRAL NEBRASKA TO NEAR KGLD AND WEST TOWARDS NORTHCENTRAL COLORADO. TONIGHT...WITH DRY/STABLE AIR MASS IN PLACE WE SHOULD SEE DRY CONDITIONS CONTINUE THROUGH TONIGHT. FRONT IS PROGGED TO LIFT NORTH THROUGH THE NIGHT WITH SLIGHTLY WARMER AIR MASS BUILDING BACK OVER THE CWA. WHILE H85 TEMPS ARENT TOO DIFFERENT THAN LAST NIGHT...WINDS MAY REMAIN IN THE 10-12KT RANGE WHICH COULD LIMIT RADIATIONAL COOLING. I WENT AHEAD AND BUMPED OVERNIGHT LOWS UP A LITTLE...THOUGH WITH CLEAR SKIES IF WINDS DIMINISH WE COULD END UP WITH LOWS SIMILAR TO LAST NIGHT. THURSDAY...LEE TROUGH DEEPENS THROUGH THE DAY THURSDAY WITH TIGHT PRESSURE GRADIENT DEVELOPING BY THURSDAY AFTERNOON. CONFIDENCE IS HIGH IN WINDY CONDITIONS...HOWEVER THERE ARE SOME MODEL DISCREPANCIES REGARDING WINDS ALOFT...AND THUS PEAK GUST POTENTIAL. BASED ON BL/ML WINDS ON THE NAM I WOULD BE CONFIDENT IN A PERIOD OF ADVISORY LEVEL WINDS (GUSTS 45-50MPH). GFS CONTINUES TO BE THE STRONGER MODEL...WITH HIGH END ADVISORY/NEAR WARNING CRITERIA. THE STRONGEST WINDS APPEAR TO OCCUR AROUND 00Z WHEN MIXING MIGHT NOT BE AS DEEP (CONSIDERING THE EARLIER SUNSET THIS TIME OF YEAR)...SO I WAS NOT CONFIDENT ENOUGH TO ADD A HIGHLIGHT AT THIS TIME. PRECIPITATION CHANCES INCREASE FROM MID AFTERNOON THROUGH 00Z AS LAPSE RATES STEEPEN ALONG SURFACE TROUGH IN EASTERN COLORADO. TD VALUES GENERALLY IN THE 40S WILL LIMIT CAPE TO 500 J/KG OR LESS...AND THUNDERSTORMS WILL BE HIGH BASED (LCL/LFC AROUND 10KFT). AT THE SAME TIME UNIDIRECTIONAL SHEER WILL BE IMPRESSIVE AHEAD OF TROUGH BY LATE AFTERNOON...AND SOUNDINGS ARE INDICATIVE OF STRONG DOWNDRAFT POTENTIAL. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 1246 PM MDT WED OCT 9 2013 STRONG SHORTWAVE TROUGH WILL BRING WIDESPREAD SHOWERS AND THUNDERSTORMS THURSDAY EVENING TO THE AREA. LACK OF MOISTURE/WEAK INSTABILITY CONTINUE TO BE THE LIMITING FACTORS FOR MORE INTENSE CONVECTION. NONETHELESS...HIGH BASED THUNDERSTORMS WILL DEVELOP ALONG THE LEE TROUGH IN EASTERN COLORADO AND MOVE EAST AS A SQUALL LINE IN THE EVENING...WHILE INDIVIDUAL CELLS RACE NORTHEAST AT AROUND 50KTS. DESPITE FAVORABLE SHEAR PROFILES...UPDRAFTS WILL STRUGGLE TO ORGANIZE GIVEN SBCAPE OF LESS THAN 500 J/KG. AS A RESULT...HAIL THREAT SEEMS MINIMAL AND TORNADO THREAT EVEN LESS...HOWEVER DAMAGING WINDS WILL BE LIKELY WITH STRONGEST STORMS GIVEN HIGH BASES AND UNIDIRECTIONAL WINDS THROUGH NEARLY THE ENTIRE TROPOSPHERE. PRECIPITATION WILL END BY 06Z AS SYSTEM QUICKLY LIFTS INTO THE NORTHERN PLAINS. FRIDAY WILL BE COOLER AND DRY...BUT ANOTHER VORT LOBE WILL ROTATE THROUGH THE BASE OF THE LONGWAVE TROUGH FRIDAY NIGHT. HOWEVER...THERE WILL NOT BE ENOUGH TIME FOR MOISTURE RETURN AND THE WEAK LIFT WILL HAVE DIFFICULTY IN GENERATING MORE THAN A FEW ISOLATED TO WIDELY SCATTERED RAIN SHOWERS ACROSS NORTHERN PORTIONS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY MORNING. SHORTWAVE RIDGING WILL BRIEFLY FOLLOW SATURDAY AFTERNOON AND SATURDAY NIGHT...HOWEVER ANOTHER WEAK TROUGH WILL BE MOVING THROUGH THE FLOW ON SUNDAY BRINGING LOW CHANCES OF SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM AS SOME WEAK INSTABILITY IS FORECAST. THE MAIN SYSTEM WILL EJECT ACROSS THE CENTRAL AND NORTHERN ROCKIES MONDAY WITH PRECIPITATION CHANCES CONTINUING AS ASSOCIATED SURFACE COLD FRONT MOVES THROUGH DURING THE DAY ON MONDAY. BREEZY NORTHWEST WINDS WILL FOLLOW FRONTAL PASSAGE MONDAY AFTERNOON AND EVENING AS PRECIPITATION COMES TO AN END. THE REMAINDER OF THE PERIOD (TUESDAY AND WEDNESDAY) WILL SEE DRY NORTHWEST FLOW WITH TEMPERATURES SLIGHTLY BELOW NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 504 PM MDT WED OCT 9 2013 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. THE FIRST PART OF THE TAF PERIOD APPEARS TO REMAIN RATHER CALM...WITH LIGHT AND VARIABLE WINDS TO START AND HIGH CLOUDS MOVING INTO BOTH TAF SITES. TWO ISSUES FOR TAFS WILL BE GUSTY WINDS AND THE CHANCE FOR THUNDERSTORMS TOMORROW AFTERNOON ASSOCIATED WITH THE SURFACE TROUGH. STRONG SOUTHERLY WINDS WILL DEVELOP AS A TIGHT PRESSURE GRADIENT FORMS AROUND THE SURFACE LOW IN EASTERN COLORADO TOMORROW. SOUTHERLY WINDS SUSTAINED BETWEEN 20 TO 35 KTS COULD GUSTS UP TO AROUND 45 KTS AT KGLD AND 39 KTS AT KMCK MID- DAY/EARLY AFTERNOON TOMORROW. THERE WILL ALSO BE A CHANCE FOR THUNDERSTORMS TOMORROW AFTERNOON AHEAD OF THE SURFACE TROUGH THAT MOVES THROUGH BOTH TAF SITES....SO INCLUDED VCTS FOR KGLD AT 21Z AND FOR KMCK AT 22Z...BUT THINK THAT THUNDERSTORMS WILL OCCUR OVER BOTH SITES AROUND 0Z OR PAST THE TAF PERIOD. THERE IS SOME UNCERTAINTY AT THIS TIME WITH TIMING AND LOCATION OF THUNDERSTORMS...BUT LATER TAF ISSUANCES WILL HAVE A BETTER HANDLE ON IT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ THURSDAY FOR KSZ002>004-013>016-027>029-041-042. CO...WIND ADVISORY FROM NOON TO 9 PM MDT THURSDAY FOR COZ092. NE...WIND ADVISORY FROM 1 PM TO 10 PM CDT THURSDAY FOR NEZ081. && $$ UPDATE...LOCKHART SHORT TERM...DR LONG TERM...024 AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
531 PM MDT WED OCT 9 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 149 PM MDT WED OCT 9 2013 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW LARGE SCALE TROUGH ACROSS WESTERN CONUS WITH CLOSED 548DM H5 CENTER OVER WESTCENTRAL CALIFORNIA. 135KT H3 JET IS ROUNDING WESTERN EXTENT OF THIS TROUGH WITH WELL DEFINED PV HEIGHT ANOMALY OVER SOUTHERN CALIFORNIA. SW FLOW AHEAD OF THIS FEATURE IS IN PLACE ACROSS THE PLAINS. AT THE SURFACE A STATIONARY FRONT IS CURRENTLY EXTENDING FORM THE NORTHERN PLAINS ACROSS CENTRAL NEBRASKA TO NEAR KGLD AND WEST TOWARDS NORTHCENTRAL COLORADO. TONIGHT...WITH DRY/STABLE AIR MASS IN PLACE WE SHOULD SEE DRY CONDITIONS CONTINUE THROUGH TONIGHT. FRONT IS PROGGED TO LIFT NORTH THROUGH THE NIGHT WITH SLIGHTLY WARMER AIR MASS BUILDING BACK OVER THE CWA. WHILE H85 TEMPS ARENT TOO DIFFERENT THAN LAST NIGHT...WINDS MAY REMAIN IN THE 10-12KT RANGE WHICH COULD LIMIT RADIATIONAL COOLING. I WENT AHEAD AND BUMPED OVERNIGHT LOWS UP A LITTLE...THOUGH WITH CLEAR SKIES IF WINDS DIMINISH WE COULD END UP WITH LOWS SIMILAR TO LAST NIGHT. THURSDAY...LEE TROUGH DEEPENS THROUGH THE DAY THURSDAY WITH TIGHT PRESSURE GRADIENT DEVELOPING BY THURSDAY AFTERNOON. CONFIDENCE IS HIGH IN WINDY CONDITIONS...HOWEVER THERE ARE SOME MODEL DISCREPANCIES REGARDING WINDS ALOFT...AND THUS PEAK GUST POTENTIAL. BASED ON BL/ML WINDS ON THE NAM I WOULD BE CONFIDENT IN A PERIOD OF ADVISORY LEVEL WINDS (GUSTS 45-50MPH). GFS CONTINUES TO BE THE STRONGER MODEL...WITH HIGH END ADVISORY/NEAR WARNING CRITERIA. THE STRONGEST WINDS APPEAR TO OCCUR AROUND 00Z WHEN MIXING MIGHT NOT BE AS DEEP (CONSIDERING THE EARLIER SUNSET THIS TIME OF YEAR)...SO I WAS NOT CONFIDENT ENOUGH TO ADD A HIGHLIGHT AT THIS TIME. PRECIPITATION CHANCES INCREASE FROM MID AFTERNOON THROUGH 00Z AS LAPSE RATES STEEPEN ALONG SURFACE TROUGH IN EASTERN COLORADO. TD VALUES GENERALLY IN THE 40S WILL LIMIT CAPE TO 500 J/KG OR LESS...AND THUNDERSTORMS WILL BE HIGH BASED (LCL/LFC AROUND 10KFT). AT THE SAME TIME UNIDIRECTIONAL SHEER WILL BE IMPRESSIVE AHEAD OF TROUGH BY LATE AFTERNOON...AND SOUNDINGS ARE INDICATIVE OF STRONG DOWNDRAFT POTENTIAL. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 1246 PM MDT WED OCT 9 2013 STRONG SHORTWAVE TROUGH WILL BRING WIDESPREAD SHOWERS AND THUNDERSTORMS THURSDAY EVENING TO THE AREA. LACK OF MOISTURE/WEAK INSTABILITY CONTINUE TO BE THE LIMITING FACTORS FOR MORE INTENSE CONVECTION. NONETHELESS...HIGH BASED THUNDERSTORMS WILL DEVELOP ALONG THE LEE TROUGH IN EASTERN COLORADO AND MOVE EAST AS A SQUALL LINE IN THE EVENING...WHILE INDIVIDUAL CELLS RACE NORTHEAST AT AROUND 50KTS. DESPITE FAVORABLE SHEAR PROFILES...UPDRAFTS WILL STRUGGLE TO ORGANIZE GIVEN SBCAPE OF LESS THAN 500 J/KG. AS A RESULT...HAIL THREAT SEEMS MINIMAL AND TORNADO THREAT EVEN LESS...HOWEVER DAMAGING WINDS WILL BE LIKELY WITH STRONGEST STORMS GIVEN HIGH BASES AND UNIDIRECTIONAL WINDS THROUGH NEARLY THE ENTIRE TROPOSPHERE. PRECIPITATION WILL END BY 06Z AS SYSTEM QUICKLY LIFTS INTO THE NORTHERN PLAINS. FRIDAY WILL BE COOLER AND DRY...BUT ANOTHER VORT LOBE WILL ROTATE THROUGH THE BASE OF THE LONGWAVE TROUGH FRIDAY NIGHT. HOWEVER...THERE WILL NOT BE ENOUGH TIME FOR MOISTURE RETURN AND THE WEAK LIFT WILL HAVE DIFFICULTY IN GENERATING MORE THAN A FEW ISOLATED TO WIDELY SCATTERED RAIN SHOWERS ACROSS NORTHERN PORTIONS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY MORNING. SHORTWAVE RIDGING WILL BRIEFLY FOLLOW SATURDAY AFTERNOON AND SATURDAY NIGHT...HOWEVER ANOTHER WEAK TROUGH WILL BE MOVING THROUGH THE FLOW ON SUNDAY BRINGING LOW CHANCES OF SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM AS SOME WEAK INSTABILITY IS FORECAST. THE MAIN SYSTEM WILL EJECT ACROSS THE CENTRAL AND NORTHERN ROCKIES MONDAY WITH PRECIPITATION CHANCES CONTINUING AS ASSOCIATED SURFACE COLD FRONT MOVES THROUGH DURING THE DAY ON MONDAY. BREEZY NORTHWEST WINDS WILL FOLLOW FRONTAL PASSAGE MONDAY AFTERNOON AND EVENING AS PRECIPITATION COMES TO AN END. THE REMAINDER OF THE PERIOD (TUESDAY AND WEDNESDAY) WILL SEE DRY NORTHWEST FLOW WITH TEMPERATURES SLIGHTLY BELOW NORMAL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 504 PM MDT WED OCT 9 2013 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. THE FIRST PART OF THE TAF PERIOD APPEARS TO REMAIN RATHER CALM...WITH LIGHT AND VARIABLE WINDS TO START AND HIGH CLOUDS MOVING INTO BOTH TAF SITES. TWO ISSUES FOR TAFS WILL BE GUSTY WINDS AND THE CHANCE FOR THUNDERSTORMS TOMORROW AFTERNOON ASSOCIATED WITH THE SURFACE TROUGH. STRONG SOUTHERLY WINDS WILL DEVELOP AS A TIGHT PRESSURE GRADIENT FORMS AROUND THE SURFACE LOW IN EASTERN COLORADO TOMORROW. SOUTHERLY WINDS SUSTAINED BETWEEN 20 TO 35 KTS COULD GUSTS UP TO AROUND 45 KTS AT KGLD AND 39 KTS AT KMCK MID- DAY/EARLY AFTERNOON TOMORROW. THERE WILL ALSO BE A CHANCE FOR THUNDERSTORMS TOMORROW AFTERNOON AHEAD OF THE SURFACE TROUGH THAT MOVES THROUGH BOTH TAF SITES....SO INCLUDED VCTS FOR KGLD AT 21Z AND FOR KMCK AT 22Z...BUT THINK THAT THUNDERSTORMS WILL OCCUR OVER BOTH SITES AROUND 0Z OR PAST THE TAF PERIOD. THERE IS SOME UNCERTAINTY AT THIS TIME WITH TIMING AND LOCATION OF THUNDERSTORMS...BUT LATER TAF ISSUANCES WILL HAVE A BETTER HANDLE ON IT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...024 AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1256 PM MDT TUE OCT 8 2013 .UPDATE... ISSUED AT 820 AM MDT TUE OCT 8 2013 AN UPDATE WAS JUST COMPLETED TO ADJUST WINDS...TEMPERATURES...DEWPOINTS AND RELATIVE HUMIDITIES. LATEST GUIDANCE FROM THE HRRR AND CONSSHORT SUGGESTS WARMER HIGH TEMPERATURES...LOWER DEWPOINTS AND SLIGHTLY HIGHER WINDS. WINDS AT 1 KM UP ARE AROUND 35-45 KTS AND WITH FULL AFTERNOON MIXING...SOME GUSTS NEAR WIND ADVISORY CRITERIA WOULD BE POSSIBLE FOR THE FAR EASTERN FORECAST AREA. IN ADDITION TO TWEAKING THE GRIDS...THE RED FLAG WARNING HAS BEEN EXPANDED TO INCLUDE CHEYENNE COUNTY KANSAS AND KIT CARSON COUNTY DUE TO THE LOWER HUMIDITIES AND HIGHER WIND SPEEDS EXPECTED. IT IS POSSIBLE THAT MIXING IS LIMITED WITH CIRRUS SPREADING OVER BUT IT SEEMS THE CIRRUS IS NOT TOO DENSE SO FULL MIXING SHOULD STILL BE ABLE TO OCCUR. WILL CONTINUE TO MONITOR TRENDS...ESPECIALLY WINDS. && .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 252 AM MDT TUE OCT 8 2013 UPPER FLOW WILL BE SOUTHWEST THROUGH WEDNESDAY NIGHT AS A TROUGH DIGS SOUTH FROM THE PACIFIC NORTHWEST. THE UPPER LOW WILL MOVE INTO THE ROCKIES THURSDAY AND NORTHEAST INTO THE NORTHERN PLAINS THURSDAY NIGHT. SURFACE LOW PRESSURE WILL RESIDE OVER EASTERN COLORADO TODAY THROUGH THURSDAY NIGHT. CONDITIONS WILL REMAIN DRY THROUGH WEDNESDAY NIGHT DUE TO THE LACK OF FORCING AND MOISTURE. POPS WILL BE NIL FOR THOSE PERIODS. DYNAMICS AND MOISTURE MOVE INTO THE FA THURSDAY AFTERNOON AND CONTINUE THURSDAY NIGHT. PLAN TO GO WITH CHANCE POPS THURSDAY AFTERNOON AND LIKELY POPS THURSDAY NIGHT. INSTABILITY DROPS OFF AFTER MIDNIGHT SO CHANGED PRECIPITATION TO SHOWERS WITH ISOLATED THUNDER IN THE EASTERN HALF OF THE FA. SURFACE WINDS IN THE SOUTHEAST FA ARE JUST UNDER WIND ADVISORY THIS AFTERNOON. HRRR SHOWS THAT SUSTAINED WINDS SHOULD GENERALLY RANGE FROM 20 TO 25KTS OVER THE SOUTHEAST ZONES WITH GUSTS UNDER ADVISORY AS WELL. THIS DECISION WAS ALSO BASED ON CONSENSUS FROM SURROUNDING OFFICES. H925-850 LAYER MEAN WINDS RANGE FROM 27 TO 36 KTS THURSDAY/THURSDAY NIGHT. H7 WINDS ARE FROM 45-48KTS. THE NAM BUFKIT SOUNDING SHOWS 35 KTS IN THE MIXING LAYER THURSDAY AFTERNOON. SINCE THIS IS PERIODS 5 AND 6 IT IS TOO EARLY FOR A WIND HIGHLIGHT. WINDS WILL NEED TO BE MONITORED IN UPCOMING SHIFTS. WINDS AND RH FOR THE RED FLAG WARNING THIS AFTERNOON LOOK ON TRACK WITH 25KTS IN THE MIXING LAYER FROM NAM BUFKIT. MIN RH VALUES FALL BELOW 15 PERCENT SO PLAN TO CONTINUE RED FLAG WARNING FOR TODAY. FOR FIRE WEATHER CONSIDERATIONS WEDNESDAY, THE NAM AND GFS BUFKIT SHOWS 15 TO 20KTS IN THE MIXING LAYER WEDNESDAY AFTERNOON BUT RH VALUES ARE MARGINAL EXCEPT FOR THE FAR SOUTHWEST ZONES. MAX TEMPERATURES TODAY WILL RISE INTO THE LOWER 80S. HIGH TEMPERATURES WEDNESDAY WILL BE COOLER IN THE NORTHWEST WITH LOWER 80S ELSEWHERE ACROSS THE FA. HIGH TEMPERATURES THURSDAY WILL BE IN THE 70S ACROSS THE WESTERN HALF AND LOWER 80S IN THE EAST. MIN TEMPERATURES WILL RANGE FROM THE MID 40S WEST TO THE LOWER TO MID 50S EAST. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 1245 PM MDT TUE OCT 8 2013 NEGATIVELY TILTED SHORTWAVE TROUGH WILL EJECT NORTHEAST ACROSS COLORADO AND INTO THE NORTHERN PLAINS THURSDAY AND THURSDAY NIGHT. SHEAR PROFILES ARE EXCELLENT...HOWEVER MOISTURE AND SBCAPE WILL BE LACKING FOR A MORE PRONOUNCED SEVERE EVENT. NONETHELESS...AN ISOLATED SEVERE STORM OR TWO CANNOT BE RULED OUT WITH THE PRIMARY THREAT APPEARING TO BE WIND/BLOWING DUST AS STORMS WILL RACE NORTHEAST AT AROUND 50 MPH. AREA WILL GET DRY SLOTTED BY 06Z WITH STORMS PULLING OUT OF THE AREA AFTERWARDS. ATTENTION THEN TURNS TO A SECONDARY VORT LOBE WHICH WILL SWING THROUGH FRIDAY NIGHT AND SATURDAY. MODELS NOT IN VERY GOOD AGREEMENT WITH THE DETAILS...BUT EVEN THE STRONGER ECMWF SOLUTION SHOWS NO MUCAPE AND ONLY SCATTERED LIGHT RAIN SHOWERS AT WORST IN A COOLER AIR MASS. THERE WILL BE A REPRIEVE IN PRECIPITATION CHANCES SATURDAY NIGHT THROUGH SUNDAY...BUT ANOTHER SYSTEM WILL ORGANIZE IN THE NORTHERN ROCKIES LATE IN THE WEEKEND WITH A SERIES OF SHORTWAVE DISTURBANCES ROTATING AROUND IT BRINGING A CHANCE OF SHOWERS. AS FOR TEMPERATURES...THEY WILL BE ABOVE NORMAL THROUGH THURSDAY...THEN NEAR TO SLIGHTLY BELOW NORMAL FRIDAY THROUGH TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1119 AM MDT TUE OCT 8 2013 VFR CONDITIONS WILL PERSIST FOR THE NEXT 24 HOURS. HIGH CLOUDS CONTINUE TO STREAM IN FROM THE WEST. ACCORDING TO MODEL TIME/HEIGHT PROJECTIONS...THE CIRRUS SHOULD REMAIN IN PLACE THROUGH ABOUT 06Z. CIRRUS HAS LIMITED WINDS FROM BECOMING GUSTY THIS MORNING BUT MODELS AND LATEST GUIDANCE CONTINUE TO SUGGEST WINDS WILL PICK UP THIS AFTERNOON. THEREFORE...DELAYED THE INCREASE IN WIND SPEEDS FOR KGLD. KMCK LOOKS ON RELATIVELY ON TRACK. WINDS WILL SLOWLY DECREASE THIS EVENING AS THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE EAST AND THE LEE TROUGH LOW PRESSURE TO THE WEST. WINDS AT KMCK WILL BACK TO THE EAST WHILE WINDS AT KGLD WILL VEER TO THE WEST AS THE LEE TROUGH MOVES IN AFTER 06Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING UNTIL 7 PM MDT /8 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. CO...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR COZ253-254. NE...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NEZ080-081. && $$ UPDATE...RRH SHORT TERM...FS LONG TERM...024 AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1119 AM MDT TUE OCT 8 2013 .UPDATE... ISSUED AT 820 AM MDT TUE OCT 8 2013 AN UPDATE WAS JUST COMPLETED TO ADJUST WINDS...TEMPERATURES...DEWPOINTS AND RELATIVE HUMIDITIES. LATEST GUIDANCE FROM THE HRRR AND CONSSHORT SUGGESTS WARMER HIGH TEMPERATURES...LOWER DEWPOINTS AND SLIGHTLY HIGHER WINDS. WINDS AT 1 KM UP ARE AROUND 35-45 KTS AND WITH FULL AFTERNOON MIXING...SOME GUSTS NEAR WIND ADVISORY CRITERIA WOULD BE POSSIBLE FOR THE FAR EASTERN FORECAST AREA. IN ADDITION TO TWEAKING THE GRIDS...THE RED FLAG WARNING HAS BEEN EXPANDED TO INCLUDE CHEYENNE COUNTY KANSAS AND KIT CARSON COUNTY DUE TO THE LOWER HUMIDITIES AND HIGHER WIND SPEEDS EXPECTED. IT IS POSSIBLE THAT MIXING IS LIMITED WITH CIRRUS SPREADING OVER BUT IT SEEMS THE CIRRUS IS NOT TOO DENSE SO FULL MIXING SHOULD STILL BE ABLE TO OCCUR. WILL CONTINUE TO MONITOR TRENDS...ESPECIALLY WINDS. && .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 252 AM MDT TUE OCT 8 2013 UPPER FLOW WILL BE SOUTHWEST THROUGH WEDNESDAY NIGHT AS A TROUGH DIGS SOUTH FROM THE PACIFIC NORTHWEST. THE UPPER LOW WILL MOVE INTO THE ROCKIES THURSDAY AND NORTHEAST INTO THE NORTHERN PLAINS THURSDAY NIGHT. SURFACE LOW PRESSURE WILL RESIDE OVER EASTERN COLORADO TODAY THROUGH THURSDAY NIGHT. CONDITIONS WILL REMAIN DRY THROUGH WEDNESDAY NIGHT DUE TO THE LACK OF FORCING AND MOISTURE. POPS WILL BE NIL FOR THOSE PERIODS. DYNAMICS AND MOISTURE MOVE INTO THE FA THURSDAY AFTERNOON AND CONTINUE THURSDAY NIGHT. PLAN TO GO WITH CHANCE POPS THURSDAY AFTERNOON AND LIKELY POPS THURSDAY NIGHT. INSTABILITY DROPS OFF AFTER MIDNIGHT SO CHANGED PRECIPITATION TO SHOWERS WITH ISOLATED THUNDER IN THE EASTERN HALF OF THE FA. SURFACE WINDS IN THE SOUTHEAST FA ARE JUST UNDER WIND ADVISORY THIS AFTERNOON. HRRR SHOWS THAT SUSTAINED WINDS SHOULD GENERALLY RANGE FROM 20 TO 25KTS OVER THE SOUTHEAST ZONES WITH GUSTS UNDER ADVISORY AS WELL. THIS DECISION WAS ALSO BASED ON CONSENSUS FROM SURROUNDING OFFICES. H925-850 LAYER MEAN WINDS RANGE FROM 27 TO 36 KTS THURSDAY/THURSDAY NIGHT. H7 WINDS ARE FROM 45-48KTS. THE NAM BUFKIT SOUNDING SHOWS 35 KTS IN THE MIXING LAYER THURSDAY AFTERNOON. SINCE THIS IS PERIODS 5 AND 6 IT IS TOO EARLY FOR A WIND HIGHLIGHT. WINDS WILL NEED TO BE MONITORED IN UPCOMING SHIFTS. WINDS AND RH FOR THE RED FLAG WARNING THIS AFTERNOON LOOK ON TRACK WITH 25KTS IN THE MIXING LAYER FROM NAM BUFKIT. MIN RH VALUES FALL BELOW 15 PERCENT SO PLAN TO CONTINUE RED FLAG WARNING FOR TODAY. FOR FIRE WEATHER CONSIDERATIONS WEDNESDAY, THE NAM AND GFS BUFKIT SHOWS 15 TO 20KTS IN THE MIXING LAYER WEDNESDAY AFTERNOON BUT RH VALUES ARE MARGINAL EXCEPT FOR THE FAR SOUTHWEST ZONES. MAX TEMPERATURES TODAY WILL RISE INTO THE LOWER 80S. HIGH TEMPERATURES WEDNESDAY WILL BE COOLER IN THE NORTHWEST WITH LOWER 80S ELSEWHERE ACROSS THE FA. HIGH TEMPERATURES THURSDAY WILL BE IN THE 70S ACROSS THE WESTERN HALF AND LOWER 80S IN THE EAST. MIN TEMPERATURES WILL RANGE FROM THE MID 40S WEST TO THE LOWER TO MID 50S EAST. .LONG TERM...(FRIDAY THROUGH NEXT TUESDAY) ISSUED AT 238 AM MDT TUE OCT 8 2013 A NEGATIVE TILTED TROUGH WILL BEGIN TO EXIT THE HIGH PLAINS REGION ON FRIDAY...AND A SHORTWAVE TROUGH AT THE UPPER LEVELS WILL MOVE INTO THE REGION SATURDAY. A SHORTWAVE RIDGE PATTERN WILL BE PRESENT OVER THE TRI STATE AREA FOR SUNDAY BEFORE ANOTHER LONGWAVE TROUGH MOVES INTO THE AREA FOR MONDAY AND TUESDAY. UPPER LEVEL JET SPEEDS WILL BE FAIRLY MILD THROUGH THE PERIOD...WITH CHANCES FOR STRONGER WINDS TO MOVE OVER THE AREA FOR TUESDAY WITH THE NEW TROUGH PATTERN. STRONGER LOWER LEVEL JET ACTIVITY IS FORECASTED TO MOVE THROUGH THE HIGH PLAINS SATURDAY WHICH COULD KEEP SOME LINGERING SHOWERS FOR THE EASTERN COLORADO COUNTIES BEHIND THE FRONTAL PASSAGE. OTHERWISE...MOST OF THE WARNING AREA SHOULD BE DRY FOR THE WEEKEND WITH COOLER CONDITIONS. WINDS COULD BE STRONG WITH TIGHT PRESSURE GRADIENT OVER THE CENTRAL PLAINS FOR FRIDAY AND POSSIBLY EARLY SATURDAY. TEMPERATURES SHOULD REMAIN NEAR NORMAL IN THE MID 60S FOR THE BEGINNING OF NEXT WEEK AS MORE COOL AIR MOVES INTO THE HIGH PLAINS WITH ANOTHER COLD FRONT MONDAY EVENING. CHANCES FOR PRECIPITATION WILL EXIST AHEAD OF THE FRONT MONDAY AND TUESDAY MORNING. EXPECT HIGH TEMPERATURES TO DROP INTO THE MID 50S FOR TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1119 AM MDT TUE OCT 8 2013 VFR CONDITIONS WILL PERSIST FOR THE NEXT 24 HOURS. HIGH CLOUDS CONTINUE TO STREAM IN FROM THE WEST. ACCORDING TO MODEL TIME/HEIGHT PROJECTIONS...THE CIRRUS SHOULD REMAIN IN PLACE THROUGH ABOUT 06Z. CIRRUS HAS LIMITED WINDS FROM BECOMING GUSTY THIS MORNING BUT MODELS AND LATEST GUIDANCE CONTINUE TO SUGGEST WINDS WILL PICK UP THIS AFTERNOON. THEREFORE...DELAYED THE INCREASE IN WIND SPEEDS FOR KGLD. KMCK LOOKS ON RELATIVELY ON TRACK. WINDS WILL SLOWLY DECREASE THIS EVENING AS THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE EAST AND THE LEE TROUGH LOW PRESSURE TO THE WEST. WINDS AT KMCK WILL BACK TO THE EAST WHILE WINDS AT KGLD WILL VEER TO THE WEST AS THE LEE TROUGH MOVES IN AFTER 06Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING UNTIL 7 PM MDT /8 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. CO...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR COZ253-254. NE...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NEZ080-081. && $$ UPDATE...RRH SHORT TERM...FS LONG TERM...MK AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
820 AM MDT TUE OCT 8 2013 .UPDATE... ISSUED AT 820 AM MDT TUE OCT 8 2013 AN UPDATE WAS JUST COMPLETED TO ADJUST WINDS...TEMPERATURES...DEWPOINTS AND RELATIVE HUMIDITIES. LATEST GUIDANCE FROM THE HRRR AND CONSSHORT SUGGESTS WARMER HIGH TEMPERATURES...LOWER DEWPOINTS AND SLIGHTLY HIGHER WINDS. WINDS AT 1 KM UP ARE AROUND 35-45 KTS AND WITH FULL AFTERNOON MIXING...SOME GUSTS NEAR WIND ADVISORY CRITERIA WOULD BE POSSIBLE FOR THE FAR EASTERN FORECAST AREA. IN ADDITION TO TWEAKING THE GRIDS...THE RED FLAG WARNING HAS BEEN EXPANDED TO INCLUDE CHEYENNE COUNTY KANSAS AND KIT CARSON COUNTY DUE TO THE LOWER HUMIDITIES AND HIGHER WIND SPEEDS EXPECTED. IT IS POSSIBLE THAT MIXING IS LIMITED WITH CIRRUS SPREADING OVER BUT IT SEEMS THE CIRRUS IS NOT TOO DENSE SO FULL MIXING SHOULD STILL BE ABLE TO OCCUR. WILL CONTINUE TO MONITOR TRENDS...ESPECIALLY WINDS. && .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 252 AM MDT TUE OCT 8 2013 UPPER FLOW WILL BE SOUTHWEST THROUGH WEDNESDAY NIGHT AS A TROUGH DIGS SOUTH FROM THE PACIFIC NORTHWEST. THE UPPER LOW WILL MOVE INTO THE ROCKIES THURSDAY AND NORTHEAST INTO THE NORTHERN PLAINS THURSDAY NIGHT. SURFACE LOW PRESSURE WILL RESIDE OVER EASTERN COLORADO TODAY THROUGH THURSDAY NIGHT. CONDITIONS WILL REMAIN DRY THROUGH WEDNESDAY NIGHT DUE TO THE LACK OF FORCING AND MOISTURE. POPS WILL BE NIL FOR THOSE PERIODS. DYNAMICS AND MOISTURE MOVE INTO THE FA THURSDAY AFTERNOON AND CONTINUE THURSDAY NIGHT. PLAN TO GO WITH CHANCE POPS THURSDAY AFTERNOON AND LIKELY POPS THURSDAY NIGHT. INSTABILITY DROPS OFF AFTER MIDNIGHT SO CHANGED PRECIPITATION TO SHOWERS WITH ISOLATED THUNDER IN THE EASTERN HALF OF THE FA. SURFACE WINDS IN THE SOUTHEAST FA ARE JUST UNDER WIND ADVISORY THIS AFTERNOON. HRRR SHOWS THAT SUSTAINED WINDS SHOULD GENERALLY RANGE FROM 20 TO 25KTS OVER THE SOUTHEAST ZONES WITH GUSTS UNDER ADVISORY AS WELL. THIS DECISION WAS ALSO BASED ON CONSENSUS FROM SURROUNDING OFFICES. H925-850 LAYER MEAN WINDS RANGE FROM 27 TO 36 KTS THURSDAY/THURSDAY NIGHT. H7 WINDS ARE FROM 45-48KTS. THE NAM BUFKIT SOUNDING SHOWS 35 KTS IN THE MIXING LAYER THURSDAY AFTERNOON. SINCE THIS IS PERIODS 5 AND 6 IT IS TOO EARLY FOR A WIND HIGHLIGHT. WINDS WILL NEED TO BE MONITORED IN UPCOMING SHIFTS. WINDS AND RH FOR THE RED FLAG WARNING THIS AFTERNOON LOOK ON TRACK WITH 25KTS IN THE MIXING LAYER FROM NAM BUFKIT. MIN RH VALUES FALL BELOW 15 PERCENT SO PLAN TO CONTINUE RED FLAG WARNING FOR TODAY. FOR FIRE WEATHER CONSIDERATIONS WEDNESDAY, THE NAM AND GFS BUFKIT SHOWS 15 TO 20KTS IN THE MIXING LAYER WEDNESDAY AFTERNOON BUT RH VALUES ARE MARGINAL EXCEPT FOR THE FAR SOUTHWEST ZONES. MAX TEMPERATURES TODAY WILL RISE INTO THE LOWER 80S. HIGH TEMPERATURES WEDNESDAY WILL BE COOLER IN THE NORTHWEST WITH LOWER 80S ELSEWHERE ACROSS THE FA. HIGH TEMPERATURES THURSDAY WILL BE IN THE 70S ACROSS THE WESTERN HALF AND LOWER 80S IN THE EAST. MIN TEMPERATURES WILL RANGE FROM THE MID 40S WEST TO THE LOWER TO MID 50S EAST. .LONG TERM...(FRIDAY THROUGH NEXT TUESDAY) ISSUED AT 238 AM MDT TUE OCT 8 2013 A NEGATIVE TILTED TROUGH WILL BEGIN TO EXIT THE HIGH PLAINS REGION ON FRIDAY...AND A SHORTWAVE TROUGH AT THE UPPER LEVELS WILL MOVE INTO THE REGION SATURDAY. A SHORTWAVE RIDGE PATTERN WILL BE PRESENT OVER THE TRI STATE AREA FOR SUNDAY BEFORE ANOTHER LONGWAVE TROUGH MOVES INTO THE AREA FOR MONDAY AND TUESDAY. UPPER LEVEL JET SPEEDS WILL BE FAIRLY MILD THROUGH THE PERIOD...WITH CHANCES FOR STRONGER WINDS TO MOVE OVER THE AREA FOR TUESDAY WITH THE NEW TROUGH PATTERN. STRONGER LOWER LEVEL JET ACTIVITY IS FORECASTED TO MOVE THROUGH THE HIGH PLAINS SATURDAY WHICH COULD KEEP SOME LINGERING SHOWERS FOR THE EASTERN COLORADO COUNTIES BEHIND THE FRONTAL PASSAGE. OTHERWISE...MOST OF THE WARNING AREA SHOULD BE DRY FOR THE WEEKEND WITH COOLER CONDITIONS. WINDS COULD BE STRONG WITH TIGHT PRESSURE GRADIENT OVER THE CENTRAL PLAINS FOR FRIDAY AND POSSIBLY EARLY SATURDAY. TEMPERATURES SHOULD REMAIN NEAR NORMAL IN THE MID 60S FOR THE BEGINNING OF NEXT WEEK AS MORE COOL AIR MOVES INTO THE HIGH PLAINS WITH ANOTHER COLD FRONT MONDAY EVENING. CHANCES FOR PRECIPITATION WILL EXIST AHEAD OF THE FRONT MONDAY AND TUESDAY MORNING. EXPECT HIGH TEMPERATURES TO DROP INTO THE MID 50S FOR TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 524 AM MDT TUE OCT 8 2013 VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24 HOURS. BREEZY SOUTH WIND CAN BE EXPECTED THROUGH A GOOD PART OF THE PERIOD FOR KGLD AND TAPER OFF SOME AT KMCK TOWARD SUNRISE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 7 PM MDT /8 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. CO...RED FLAG WARNING FROM NOON TODAY TO 7 PM MDT THIS EVENING FOR COZ253-254. NE...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR NEZ080-081. && $$ UPDATE...RRH SHORT TERM...FS LONG TERM...MK AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
531 AM MDT TUE OCT 8 2013 .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 252 AM MDT TUE OCT 8 2013 UPPER FLOW WILL BE SOUTHWEST THROUGH WEDNESDAY NIGHT AS A TROUGH DIGS SOUTH FROM THE PACIFIC NORTHWEST. THE UPPER LOW WILL MOVE INTO THE ROCKIES THURSDAY AND NORTHEAST INTO THE NORTHERN PLAINS THURSDAY NIGHT. SURFACE LOW PRESSURE WILL RESIDE OVER EASTERN COLORADO TODAY THROUGH THURSDAY NIGHT. CONDITIONS WILL REMAIN DRY THROUGH WEDNESDAY NIGHT DUE TO THE LACK OF FORCING AND MOISTURE. POPS WILL BE NIL FOR THOSE PERIODS. DYNAMICS AND MOISTURE MOVE INTO THE FA THURSDAY AFTERNOON AND CONTINUE THURSDAY NIGHT. PLAN TO GO WITH CHANCE POPS THURSDAY AFTERNOON AND LIKELY POPS THURSDAY NIGHT. INSTABILITY DROPS OFF AFTER MIDNIGHT SO CHANGED PRECIPITATION TO SHOWERS WITH ISOLATED THUNDER IN THE EASTERN HALF OF THE FA. SURFACE WINDS IN THE SOUTHEAST FA ARE JUST UNDER WIND ADVISORY THIS AFTERNOON. HRRR SHOWS THAT SUSTAINED WINDS SHOULD GENERALLY RANGE FROM 20 TO 25KTS OVER THE SOUTHEAST ZONES WITH GUSTS UNDER ADVISORY AS WELL. THIS DECISION WAS ALSO BASED ON CONSENSUS FROM SURROUNDING OFFICES. H925-850 LAYER MEAN WINDS RANGE FROM 27 TO 36 KTS THURSDAY/THURSDAY NIGHT. H7 WINDS ARE FROM 45-48KTS. THE NAM BUFKIT SOUNDING SHOWS 35 KTS IN THE MIXING LAYER THURSDAY AFTERNOON. SINCE THIS IS PERIODS 5 AND 6 IT IS TOO EARLY FOR A WIND HIGHLIGHT. WINDS WILL NEED TO BE MONITORED IN UPCOMING SHIFTS. WINDS AND RH FOR THE RED FLAG WARNING THIS AFTERNOON LOOK ON TRACK WITH 25KTS IN THE MIXING LAYER FROM NAM BUFKIT. MIN RH VALUES FALL BELOW 15 PERCENT SO PLAN TO CONTINUE RED FLAG WARNING FOR TODAY. FOR FIRE WEATHER CONSIDERATIONS WEDNESDAY, THE NAM AND GFS BUFKIT SHOWS 15 TO 20KTS IN THE MIXING LAYER WEDNESDAY AFTERNOON BUT RH VALUES ARE MARGINAL EXCEPT FOR THE FAR SOUTHWEST ZONES. MAX TEMPERATURES TODAY WILL RISE INTO THE LOWER 80S. HIGH TEMPERATURES WEDNESDAY WILL BE COOLER IN THE NORTHWEST WITH LOWER 80S ELSEWHERE ACROSS THE FA. HIGH TEMPERATURES THURSDAY WILL BE IN THE 70S ACROSS THE WESTERN HALF AND LOWER 80S IN THE EAST. MIN TEMPERATURES WILL RANGE FROM THE MID 40S WEST TO THE LOWER TO MID 50S EAST. .LONG TERM...(FRIDAY THROUGH NEXT TUESDAY) ISSUED AT 238 AM MDT TUE OCT 8 2013 A NEGATIVE TILTED TROUGH WILL BEGIN TO EXIT THE HIGH PLAINS REGION ON FRIDAY...AND A SHORTWAVE TROUGH AT THE UPPER LEVELS WILL MOVE INTO THE REGION SATURDAY. A SHORTWAVE RIDGE PATTERN WILL BE PRESENT OVER THE TRI STATE AREA FOR SUNDAY BEFORE ANOTHER LONGWAVE TROUGH MOVES INTO THE AREA FOR MONDAY AND TUESDAY. UPPER LEVEL JET SPEEDS WILL BE FAIRLY MILD THROUGH THE PERIOD...WITH CHANCES FOR STRONGER WINDS TO MOVE OVER THE AREA FOR TUESDAY WITH THE NEW TROUGH PATTERN. STRONGER LOWER LEVEL JET ACTIVITY IS FORECASTED TO MOVE THROUGH THE HIGH PLAINS SATURDAY WHICH COULD KEEP SOME LINGERING SHOWERS FOR THE EASTERN COLORADO COUNTIES BEHIND THE FRONTAL PASSAGE. OTHERWISE...MOST OF THE WARNING AREA SHOULD BE DRY FOR THE WEEKEND WITH COOLER CONDITIONS. WINDS COULD BE STRONG WITH TIGHT PRESSURE GRADIENT OVER THE CENTRAL PLAINS FOR FRIDAY AND POSSIBLY EARLY SATURDAY. TEMPERATURES SHOULD REMAIN NEAR NORMAL IN THE MID 60S FOR THE BEGINNING OF NEXT WEEK AS MORE COOL AIR MOVES INTO THE HIGH PLAINS WITH ANOTHER COLD FRONT MONDAY EVENING. CHANCES FOR PRECIPITATION WILL EXIST AHEAD OF THE FRONT MONDAY AND TUESDAY MORNING. EXPECT HIGH TEMPERATURES TO DROP INTO THE MID 50S FOR TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 524 AM MDT TUE OCT 8 2013 VFR CONDTIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24 HOURS. BREEZY SOUTH WIND CAN BE EXPECTED THROUGH A GOOD PART OF THE PERIOD FOR KGLD AND TAPER OFF SOME AT KMCK TOWARD SUNRISE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 6 PM MDT /7 PM CDT/ THIS EVENING FOR KSZ002>004-013>016-027>029-041-042. CO...RED FLAG WARNING FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR COZ254. NE...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR NEZ080-081. && $$ SHORT TERM...FS LONG TERM...MK AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
253 AM MDT TUE OCT 8 2013 .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 252 AM MDT TUE OCT 8 2013 UPPER FLOW WILL BE SOUTHWEST THROUGH WEDNESDAY NIGHT AS A TROUGH DIGS SOUTH FROM THE PACIFIC NORTHWEST. THE UPPER LOW WILL MOVE INTO THE ROCKIES THURSDAY AND NORTHEAST INTO THE NORTHERN PLAINS THURSDAY NIGHT. SURFACE LOW PRESSURE WILL RESIDE OVER EASTERN COLORADO TODAY THROUGH THURSDAY NIGHT. CONDITIONS WILL REMAIN DRY THROUGH WEDNESDAY NIGHT DUE TO THE LACK OF FORCING AND MOISTURE. POPS WILL BE NIL FOR THOSE PERIODS. DYNAMICS AND MOISTURE MOVE INTO THE FA THURSDAY AFTERNOON AND CONTINUE THURSDAY NIGHT. PLAN TO GO WITH CHANCE POPS THURSDAY AFTERNOON AND LIKELY POPS THURSDAY NIGHT. INSTABILITY DROPS OFF AFTER MIDNIGHT SO CHANGED PRECIPITATION TO SHOWERS WITH ISOLATED THUNDER IN THE EASTERN HALF OF THE FA. SURFACE WINDS IN THE SOUTHEAST FA ARE JUST UNDER WIND ADVISORY THIS AFTERNOON. HRRR SHOWS THAT SUSTAINED WINDS SHOULD GENERALLY RANGE FROM 20 TO 25KTS OVER THE SOUTHEAST ZONES WITH GUSTS UNDER ADVISORY AS WELL. THIS DECISION WAS ALSO BASED ON CONSENSUS FROM SURROUNDING OFFICES. H925-850 LAYER MEAN WINDS RANGE FROM 27 TO 36 KTS THURSDAY/THURSDAY NIGHT. H7 WINDS ARE FROM 45-48KTS. THE NAM BUFKIT SOUNDING SHOWS 35 KTS IN THE MIXING LAYER THURSDAY AFTERNOON. SINCE THIS IS PERIODS 5 AND 6 IT IS TOO EARLY FOR A WIND HIGHLIGHT. WINDS WILL NEED TO BE MONITORED IN UPCOMING SHIFTS. WINDS AND RH FOR THE RED FLAG WARNING THIS AFTERNOON LOOK ON TRACK WITH 25KTS IN THE MIXING LAYER FROM NAM BUFKIT. MIN RH VALUES FALL BELOW 15 PERCENT SO PLAN TO CONTINUE RED FLAG WARNING FOR TODAY. FOR FIRE WEATHER CONSIDERATIONS WEDNESDAY, THE NAM AND GFS BUFKIT SHOWS 15 TO 20KTS IN THE MIXING LAYER WEDNESDAY AFTERNOON BUT RH VALUES ARE MARGINAL EXCEPT FOR THE FAR SOUTHWEST ZONES. MAX TEMPERATURES TODAY WILL RISE INTO THE LOWER 80S. HIGH TEMPERATURES WEDNESDAY WILL BE COOLER IN THE NORTHWEST WITH LOWER 80S ELSEWHERE ACROSS THE FA. HIGH TEMPERATURES THURSDAY WILL BE IN THE 70S ACROSS THE WESTERN HALF AND LOWER 80S IN THE EAST. MIN TEMPERATURES WILL RANGE FROM THE MID 40S WEST TO THE LOWER TO MID 50S EAST. .LONG TERM...(FRIDAY THROUGH NEXT TUESDAY) ISSUED AT 238 AM MDT TUE OCT 8 2013 A NEGATIVE TILTED TROUGH WILL BEGIN TO EXIT THE HIGH PLAINS REGION ON FRIDAY...AND A SHORTWAVE TROUGH AT THE UPPER LEVELS WILL MOVE INTO THE REGION SATURDAY. A SHORTWAVE RIDGE PATTERN WILL BE PRESENT OVER THE TRI STATE AREA FOR SUNDAY BEFORE ANOTHER LONGWAVE TROUGH MOVES INTO THE AREA FOR MONDAY AND TUESDAY. UPPER LEVEL JET SPEEDS WILL BE FAIRLY MILD THROUGH THE PERIOD...WITH CHANCES FOR STRONGER WINDS TO MOVE OVER THE AREA FOR TUESDAY WITH THE NEW TROUGH PATTERN. STRONGER LOWER LEVEL JET ACTIVITY IS FORECASTED TO MOVE THROUGH THE HIGH PLAINS SATURDAY WHICH COULD KEEP SOME LINGERING SHOWERS FOR THE EASTERN COLORADO COUNTIES BEHIND THE FRONTAL PASSAGE. OTHERWISE...MOST OF THE WARNING AREA SHOULD BE DRY FOR THE WEEKEND WITH COOLER CONDITIONS. WINDS COULD BE STRONG WITH TIGHT PRESSURE GRADIENT OVER THE CENTRAL PLAINS FOR FRIDAY AND POSSIBLY EARLY SATURDAY. TEMPERATURES SHOULD REMAIN NEAR NORMAL IN THE MID 60S FOR THE BEGINNING OF NEXT WEEK AS MORE COOL AIR MOVES INTO THE HIGH PLAINS WITH ANOTHER COLD FRONT MONDAY EVENING. CHANCES FOR PRECIPITATION WILL EXIST AHEAD OF THE FRONT MONDAY AND TUESDAY MORNING. EXPECT HIGH TEMPERATURES TO DROP INTO THE MID 50S FOR TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1000 PM MDT MON OCT 7 2013 VFR THROUGH THE PERIOD AT KGLD AND KMCK. SFC TROUGH OVER FAR EASTERN COLORADO WILL REMAIN NEARLY STATIONARY THROUGH THE TAF PERIOD. SOUTH WINDS AROUND 10-13KTS AT TAF ISSUANCE WILL GUST INTO THE 25-30KT RANGE DURING THE DAY TUESDAY BEFORE BRIEFLY SUBSIDING BACK TO 10-15KTS BY 00Z. THIS WILL CONTINUE THROUGH THE REST OF THE TAF PERIOD AT KMCK. AT KGLD WINDS MAY START TO GUST TO 25KTS AGAIN AFTER 03Z WEDNESDAY AND CONTINUE THROUGH THE REST OF THE TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 6 PM MDT /7 PM CDT/ THIS EVENING FOR KSZ002>004-013>016-027>029-041-042. CO...RED FLAG WARNING FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR COZ254. NE...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR NEZ080-081. && $$ SHORT TERM...FS LONG TERM...MK AVIATION...99
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
724 PM EDT WED OCT 9 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 239 PM EDT WED OCT 9 2013 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG OVER THE E HALF OF THE CONUS DOWNWIND OF TROF OVER THE W. AT THE SFC...HI PRES IS SITUATED OVER NEW ENGLAND...WITH WEAKENING LO PRES OVER NW ONTARIO ASSOCIATED WITH CNDN SHRTWV RIDING OVER UPR RDG. THE CWA IS DOMINATED BY THE LLVL SW FLOW BTWN THESE FEATURES. BUT BECAUSE THE SFC LO IS WEAKENING WITH PRES RISES OBSVD OVER THE SFC LO...THE GRADIENT IS WEAKENING STEADILY WITH TIME. SO SW WINDS THIS AFTN ARE NOT AS GUSTY AS YDAY DESPITE DAYTIME HEATING/MIXING. OTRW...THE LOCAL AND UPSTREAM 12Z RAOBS SHOW A RELATIVELY DRY LLVL AIRMASS...SO THERE IS NOTHING MORE THAN PATCHY HI CLDS TO THE SW OF SOME THICKER CLDS IN ONTARIO ASSOCIATED WITH THE LO WELL N OF THE BORDER. THE ONLY EXCEPTION WAS A BIT OF LO CLD THAT DVLPD DOWNWIND OF LK MI NEAR MANISTIQUE WHERE THE SW FLOW OFF THE WATER HAS LIFTED SFC DEWPTS AS HI AS 55 TO 60. WITH A RIBBON OF H85 TEMPS UP TO 15C STREAMING INTO THE WRN CWA IN THE SW FLOW...TEMPS ARE RUNNING WELL ABV NORMAL EARLY THIS AFTN WITH READINGS AS HI AS THE LO 70S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF LK MI. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH DRY...ACYC SW FLOW ARND SFC HI PRES STRETCHING FM THE NE COAST INTO THE GREAT LKS FCST TO DOMINATE THRU THU. TNGT...EXPECT LO TEMPS TNGT TO FALL A BIT MORE THAN LAST NGT WITH DRY AIR LINGERING UNDER WEAKENING PRES GRADIENT/SW FLOW AS HIER PRES SLOWLY EXPANDS TO THE W. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCENTRAL AND E...CLOSER TO THE WEAKEST GRADIENT/LOWER PWATS AOB 0.5 INCH. WITH THESE IMPROVED RADIATIONAL COOLING CONDITIONS OVER HIER DEWPTS OBSVD THIS AFTN...EXPECT PATCHY FOG IN THESE AREAS. THU...LOOKS LIKE ANOTHER PLEASANT OCT DAY WITH DRY SW FLOW FCST TO DOMINATE AND LEAD TO MOSUNNY CONDITIONS. H85 TEMPS ARE FCST NEAR 14C...ALMOST THE SAME AS TDAY...SO EXPECT MAX TEMPS TO BE SIMILAR TO THIS AFTN. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 239 PM EDT WED OCT 9 2013 AT 00Z FRI...THERE WILL BE AN UPPER RIDGE OVER THE CWA THAT WILL GIVE WAY TO A LOW PRESSURE SYSTEM MOVING FROM NE AT 12Z FRI TO FAR SRN MANITOBA AT 12Z SAT. FRI WILL BE QUIET WITH NO PRECIP EXPECTED DUE TO THE RIDGE BEING OVERHEAD...BUT WITH 850MB TEMPS AROUND 14C...TEMPS WILL BE WELL ABOVE NORMAL WITH HIGHS IN THE 60S AND 70S. AFTER 12Z SAT...MODEL DISAGREEMENT ON THE TIMING/TRACK OF THE SYSTEM IS MORE UNCERTAIN. THE 12Z/09 GFS KEEPS THE LOW MOVING RAPIDLY NNE TO HUDSON BAY BY 00Z SUN...WHILE 00Z/09 ECMWF HANGS THE LOW OVER ONTARIO WHILE WEAKENING...AND FINALLY MOVING TO JAMES BAY AROUND 06Z MON. THE 00Z/09 GEM SOLUTION IS BETWEEN THE GFS AND ECMWF WITH TIMING/TRACK. PRECIP OVER THE CWA FROM THIS SYSTEM WILL MAINLY RESULT FROM THE ASSOCIATED COLD FRONT MOVING THROUGH. OF COURSE...THERE ARE ALSO SOME TIMING DIFFERENCES WITH TIMING OF FROPA. THE GFS MOVES THE FRONT FROM THE WRN U.P. AT 18Z SAT TO THE ERN CWA AROUND 06Z SUN...WITH THE ECMWF BEING AROUND 6 HOURS SLOWER. THE GEM MATCHES UP PRETTY CLOSE TO THE GFS WITH FROPA TIMING. THERE MAY BE SOME SHOWERS OVER THE WRN CWA FRI NIGHT AS THE LOW MOVES TO THE W...BUT OTHERWISE MOST PRECIP WITH THE FRONT SHOULD BE OVER THE CENTRAL AND ERN CWA WHERE THE FRONT WILL INTERACT WITH BETTER INSTABILITY AND MAY BE BACKED UP BY AN UPPER SHORTWAVE TROUGH. WILL NOT GO COMPLETELY DRY OVER THE W...BUT WILL HAVE HIGHEST POPS CENTRAL AND E AND TIMING CLOSER THE GFS/GEM SOLUTIONS. COLDER AIR WILL FILTER IN BEHIND THE SYSTEM...WITH 850MB TEMPS FALLING INTO THE LOW SINGLE DIGITS ABOVE AND MAYBE JUST BELOW ZERO BY LATE SUN/SUN NIGHT. THIS IS WHERE THE MODEL DIFFERENCES BECOME MORE SIGNIFICANT AS THE GFS AND GEM USHER IN DRY HIGH PRESSURE FOR SUN NIGHT WHILE THE ECMWF SOLUTION WITH THE LAGGING LOW WILL KEEP MORE CLOUDS OVERHEAD. WITH THE CLOUDIER ECMWF SOLUTION...LOW TEMPS SUN NIGHT SHOULD FALL INTO THE UPPER 30S TO MID 40S. THE LESS CLOUDY SOLUTIONS WOULD LIKELY RESULT IN A DECENT FREEZE AWAY FROM THE IMMEDIATE SHORES OF THE GREAT LAKES. WILL GO WITH A MIDDLE OF THE ROAD APPROACH AND KEEP CONSENSUS LOW TEMPS FROM THE MID 30S TO MID 40S. THINGS BECOME MORE UNCERTAIN MON THROUGH NEXT WED AS MODELS CONTINUE TO POINT TO A MAJOR PATTERN CHANGE FROM THIS PORTION OF THE COUNTRY. MODELS GENERALLY SHOW MUCH INCREASED UPPER TROUGHING OVER THE ERN HAVE OF THE CONUS...RESULTING IN COLDER TEMPERATURES AND GREATER STRENGTH/FREQUENCY OF SYSTEMS MOVING THROUGH THE REGION. DEFINITELY LOOKS COLDER WITH TEMPS EVEN FALLING TO BELOW NORMAL VALUES. POPS ARE FAR MORE UNCERTAIN AS SYSTEM STRENGTH/TRACK IS FAR FROM CERTAIN. TEMPS DO NOT LOOK QUITE COLD ENOUGH TO ADD MIXED PRECIP TO THE FORECAST...ESPECIALLY GIVEN UNCERTAINTY INVOLVED. USED A CONSENSUS OF MODEL GUIDANCE FOR THIS PORTION OF THE FORECAST PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 723 PM EDT WED OCT 9 2013 WINDS ON THU SHOULD NOT BE AS GUSTY AS TODAY WITH A WEAKER GRADIENT STILL IN PLACE. OTHERWISE...DRY HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE TAF SITES THIS FCST PERIOD. THE ONE EXCEPTION MAY BE SAW LATE TONIGHT OR EARLY THU...WHERE SOME FOG COULD DEVELOP. WITH THE LLVL FLOW MORE SSW COMPARED TO SSE OFF LAKE MI...PROBABILITY OF FOG FORMATION WAS LOW ENOUGH TO KEEP VFR FCST GOING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 239 PM EDT WED OCT 9 2013 EXPECT S TO SW WINDS UP TO 20 KTS THRU THU NIGHT TO INCREASE TO UP TO 25 KTS ON FRI INTO SAT AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES OVER THE EASTERN CONUS AND AN APPROACHING COLD FRONT. BEHIND THIS FRONTAL PASSAGE ON SAT...LOOK FOR A WIND SHIFT TO THE W-NW BEFORE WINDS SLOWLY VEER TO THE N BY MON AHEAD OF AN APPROACHING HI PRES CENTER. WINDS WILL BE AS HI AS 20-25 KTS ON SAT NIGHT/SUN FOLLOWING THIS FROPA...BUT THESE WINDS SHOULD DIMINISH UNDER 20 KTS BY MON AS THE HI PRES/WEAKER PRES GRADIENT MOVES NEARBY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...JLB MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
119 AM EDT TUE OCT 8 2013 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 346 PM EDT MON OCT 7 2013 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF OVER THE GREAT LKS SANDWICHED BTWN UPR RDG OVER THE ROCKIES/WRN PLAINS AND ANOTHER RDG OFF THE E COAST. H925-85 THERMAL TROF ASSOCIATED WITH REINFORCING SHRTWV DIGGING INTO THE UPR LKS AND MOIST LLVLS SHOWN ON THE 12Z YPL RAOB HAVE BROUGHT QUITE A BIT OF CLD COVER TO MUCH OF THE CWA...AND THERE HAVE EVEN BEEN A FEW -SHRA...MAINLY OVER THE E HALF OF UPR MI. THE CLDS HAVE BEEN MORE SCT NEAR THE WI BORDER AND ESPECIALLY THE SCENTRAL...WHERE LLVL NW FLOW BTWN SFC LO PRES MOVING INTO QUEBEC AND HI PRES IN THE PLAINS IS DOWNSLOPING. MAIN FCST CONCERNS IN THE SHORT TERM ARE MAINLY LO CLD TRENDS/TEMPS. TNGT...SINCE THE UPR PATTERN IS RATHER PROGRESSIVE...MODELS SHOW UPR RDG AXIS TO THE W SLIDING E AND OVER THE MS RIVER VALLEY BY 12Z TUE... WITH SFC HI PRES SHIFTING INTO THE OH RIVER VALLEY. ALTHOUGH LINGERING LLVL THERMAL TROF/CYC NW FLOW WL MAINTAIN SOME LO CLDS OVER THE E HALF THIS EVNG...ARRIVAL OF SFC HI PRES RDG AXIS AND BACKING LLVL FLOW TO THE W AND THEN SW WL CAUSE SKIES TO TURN MOCLR. THERE COULD BE SOME MID/HI CLDS OVER MAINLY THE NW LATER IN THE RETURN SW FLOW...BUT THE BULK OF THIS CLD SHOULD STAY IN CANADA. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCENTRAL...WHERE SKIES WL BE MOCLR/WINDS LIGHTER THRU THE NGT. TUE...THE CWA WL BE DOMINATED BY A STRONG SW FLOW UNDER SHARPENING PRES GRADIENT BTWN SFC HI PRES MOVING INTO THE MID ATLANTIC STATES AND SFC LO PRES IN SCENTRAL CANADA RIDING OVER THE UPR RDG. ALTHOUGH SOME DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THIS FEATURE/WAD WL BRUSH THE NW CWA...FCST SDNGS SHOW SO MUCH LO-MID DRY AIR THAT THE ONLY IMPACT WL BE SOME HI CLDS. 12Z NAM/GFS SHOW SW H925 WINDS INCRSG TO 45-50 KTS IN THE AFTN OVER THE WRN CWA TO THE S OF PRES FALL CENTER OVER NW ONTARIO E OF THE SFC LO CENTER. MIXING TO H925 ON FCST SDNGS YIELDS HI TEMPS APRCHG 70 OVER THE W AND HINTS SOME WIND GUSTS MAY AT LEAST APRCH ADVY CRITERIA AT EXPOSED LOCATIONS OVER THE W. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 346 PM EDT MON OCT 7 2013 WITH THE UPPER TROUGH PEELING OUT OF THE UPPER GREAT LAKES REGION TONIGHT...AN UPPER RIDGE WILL BUILD OVER THE EASTERN CONUS AND REMAIN THROUGH THE END OF THE WORK WEEK. WITH A SURFACE HIGH OVER THE NEW ENGLAND STATES AND A LOW MOVING THROUGH CENTRAL CANADA...SOUTH-SOUTHWESTERLY FLOW WILL PULL WARM AIR OVER THE AREA. THIS WILL LEAD TO ABOVE NORMAL TEMPERATURES (GENERALLY IN THE MID 60S TO LOWER 70S) THROUGH THE END OF THE WORK WEEK. AS FOR WEATHER...EXPECT DRY CONDITIONS DURING THIS PERIOD WITH GENERALLY MOSTLY CLEAR SKIES. IT WILL STILL BE A LITTLE BREEZY ON WEDNESDAY AS THE PRESSURE GRADIENT IS GRADUALLY WEAKENING DUE TO THE LOW IN CANADA WEAKENING WHILE SHIFTING INTO THE CANADIAN MARITIMES. THERE ARE SOME HINTS OF FOG IN THE NAM/SREF OVER THE SOUTH CENTRAL AND EAST FOR WEDNESDAY NIGHT INTO THURSDAY MORNING. THE WEAKENING OF THE PRESSURE GRADIENT OVER THE AREA THAT STARTS ON WEDNESDAY WILL CONTINUE INTO WEDNESDAY NIGHT AND THURSDAY. SINCE SKIES WILL BE CLEAR AND IT SEEMS LIKE A BETTER RADIATIONAL COOLING NIGHT THAT MAY NOT BE TOO UNREASONABLE BUT DIDN/T ADD ANY FOG AT THIS TIME. AN UPPER TROUGH THAT DIVES INTO THE SOUTHWESTERN CONUS AROUND MID WEEK WILL BE THE MAIN WEATHER MAKER FOR THIS WEEKEND. THIS TROUGH WILL EJECT NORTHEAST INTO THE PLAINS ON FRIDAY AND THEN INTO THE UPPER MISSISSIPPI VALLEY FRIDAY NIGHT INTO SATURDAY. THE SURFACE LOW WILL FOLLOW A SIMILAR TRACK BUT THE CWA SHOULD STILL SEE AN ASSOCIATED COLD FRONT AND SHOWERS SLIDE ACROSS THE AREA ON SATURDAY. WILL CONTINUE TO SHOW THAT LINE OF SHOWERS SLIDING ACROSS THE CWA LATE FRIDAY NIGHT AND SATURDAY WITH CHANCE POPS. DID PUT IN A MENTION OF A RUMBLE OF THUNDER INTO THE GRIDS OVER THE SOUTH CENTRAL...AS THERE IS A POCKET OF MARGINAL MUCAPE VALUES ALONG THE FRONT (ALONG WITH SHOWALTER APPROACHING ZERO). BEHIND THE UPPER TROUGH...MODEL DIFFERENCES REALLY BEGIN TO GROW ON THE SMALLER SCALE FEATURES AFFECTING THE AREA. BUT THE LARGER SCALE IDEA OF AN UPPER TROUGH OVER THE WESTERN 2/3RDS OF THE CONUS AND THE UPPER GREAT LAKES REGION BEING ON THE EASTERN EDGE OF THE TROUGH. 00Z/12Z ECMWF/GEM RUNS ARE SHOWING A SECONDARY SHORTWAVE EJECTING FROM THE UPPER TROUGH AND THROUGH THE UPPER GREAT LAKES REGION ON SUNDAY INTO SUNDAY EVENING. 12Z GFS (LIKE IT/S PREVIOUS RUN) STILL HOLDS ONTO THE DRIER IDEA AND NO SHORTWAVE MOVING THROUGH. SINCE IT IS STILL A WAYS OFF...WILL FOLLOW A HIGH END SLIGHT AND LOW END CHANCE CONSENSUS FOR THE POPS AND SEE WHICH WAY THE MODELS GO. IF THE GEM/ECMWF SOLUTION PANS OUT...COULD SEE A DECENT RAINFALL FOR PORTIONS OF THE CWA ON SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 118 AM EDT TUE OCT 8 2013 DRY AIR MASS ASSOCIATED WITH SFC HIGH PRES RIDGE MOVING FROM THE WRN GREAT LAKES OVERNIGHT TO THE LOWER GREAT LAKES TODAY WILL ENSURE VFR CONDITIONS THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW. TIGHTENING PRES GRADIENT BTWN THE DEPARTING HIGH AND LOW PRES MOVING ACROSS SCNTRL CANADA WILL LEAD TO LLWS EARLY THIS MORNING AT KIWD. DEEPENING MIXED LAYER AND TIGHT PRES GRADIENT WILL THEN LEAD TO GUSTY WINDS AT ALL TERMINALS TODAY. WITH KIWD/KSAW MORE EXPOSED TO SOUTHERLY WINDS... EXPECT GUSTS TO 30KT OR BETTER AT THOSE TERMINALS IN THE AFTN. WHERE WINDS DECOUPLE TONIGHT (MOST LIKELY AT KCMX WHICH IS MORE SHELTERED WITH S WINDS)...LLWS WILL AGAIN DEVELOP. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 346 PM EDT MON OCT 7 2013 EXPECT NW WINDS UP TO 20 TO 30 KTS LATE THIS AFTERNOON TO DIMINISH STEADILY W-E TONIGHT AS A HI PRES RIDGE MOVES ACROSS LAKE SUPERIOR. A STRONGER S FLOW...WITH WINDS UP TO 30 KTS...WILL THEN DOMINATE LATER TUE/TUE NIGHT AS THE HI PRES SHIFTS TO THE E AND A SHARPER GRADIENT BETWEEN THIS FEATURE AND A LO PRES SYSTEM MOVING THRU SCENTRAL CANADA GETS SITUATED OVER THE UPPER LAKES. PLAN ON LIGHTER S-SW WINDS WED THRU SAT AS THE HI TO THE E REBUILDS BACK TOWARD THE AREA...RESULTING IN A WEAKER GRADIENT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
914 AM MDT TUE OCT 8 2013 .UPDATE... MID LEVEL CLOUDS STREAMING ACROSS THE AREA THIS MORNING IN SOUTHWEST FLOW ALOFT WITH GENERALLY LIGHT WINDS. COOLER TEMPERATURES AND DRY BEHIND THE OVERNIGHT FRONTAL PASSAGE WITH A BIT OF MOISTURE PUSHING INTO THE MOUNTAINS LATE TODAY. NO UPDATES TO GOING FORECAST. BORSUM && .SHORT TERM...VALID FOR TDY AND WED... A GENERALLY BENIGN COLD FRONT CURRENTLY MOVING THROUGH THE AREA WITH WIND SHIFT TO THE N/NW AT LVM-BIL-MLS AS OF 08Z. THIS IS ASSOCIATED WITH SHORTWAVE SKIRTING ACROSS NORTH CENTRAL MT. LOOKING WEST...SATELLITE IMAGERY SHOWS STRONG NORTHERLY JET ALONG THE BC COAST...WITH LATEST RAP ANALYSIS SHOWING 140 KTS AT 300MB. SO AMPLIFICATION OF THE FLOW IS UNDERWAY AS THIS JET WILL ALLOW FOR A LOW TO CUT OFF OVER CA ON WEDNESDAY...WHICH WILL EVENTUALLY BECOME A PLAYER IN OUR REGION BY THURSDAY. CURRENT FRONTAL PASSAGE IS A DRY ONE WITH ONLY SOME MID AND HIGH CLOUD OVER OUR REGION. COMBINATION OF WEAK MID LEVEL FRONTOGENESIS ALONG IDAHO PV MAX AND SOME MODEST DIURNAL HEATING SHOULD ALLOW FOR SOME LIGHT SHOWERS TO DEVELOP OVER OUR SOUTHERN MTNS LATE THIS AFTERNOON...WITH A TURNING OF THE LOW LEVEL FLOW TO NORTH/UPSLOPE HELPING THIS CAUSE. MORE INTERESTING FACET OF THE NEXT 24-36 HOURS IS THE PERIOD OF FAIRLY STRONG/MOIST ISENTROPIC ASCENT FROM THE SOUTH AS LOW DEEPENS TO OUR WEST LATE TONIGHT AND WEDNESDAY. MODELS ARE CONSISTENT IN SHOWING LIFT BUT DIFFER IN STRENGTH OF ASCENT AND PRODUCTION OF QPF. FEEL THAT THE DEPTH OF MID LEVEL FORCING AND MOISTURE...ALONG WITH LOW LEVEL UPSLOPE FLOW...WILL BE ENOUGH FOR SOME LIGHT PCPN AND WILL SUSTAIN CHANCE POPS ON WEDNESDAY. PCPN TYPE WILL BE RAIN AT LOWER ELEVATIONS WITH SOME SNOW ABOVE 7KFT OR SO. MID LEVEL WARM FRONT WHICH SHOULD BE THE FOCUS OF THE PCPN WILL LIFT NORTH OF OUR AREA BY LATE WEDNESDAY AFTERNOON. WILL SUSTAIN LOW POPS FOR WEDNESDAY NIGHT BUT FORCING DOES BECOME MUCH WEAKER AND THIS MAY TURN OUT TO BE A DRY PERIOD...AS WE AWAIT UPPER LOW TO OUR SW. TEMPS WILL TURN BACK BELOW NORMAL THESE NEXT COUPLE DAYS...WITH HIGHS IN THE LOW TO MID 60S TODAY AND IN THE 50S/NEAR 60 ON WEDNESDAY...WITH TEMPS ON THE LATTER DAY POTENTIALLY IMPACTED BY LIGHT PCPN. MONDAY AFTERNOON VISIBLE IMAGERY STILL SHOWED SOME SNOW COVER ALONG THE NORTH SLOPES WHICH WILL HAVE A LITTLE IMPACT ON TEMPS IN THESE AREAS AGAIN TODAY. NOT IN BILLINGS THOUGH...PER SHIFT FROM SW TO NW-N WINDS...SO EXPECT THE CITY TO ACTUALLY REACH ITS POTENTIAL TODAY WITH A HIGH TEMP INTO THE LOW 60S. JKL .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... THE FOCUS FOR THIS EXTENDED PACKAGE WILL BE TWO TIME FRAMES. THE FIRST WILL BE THURSDAY THROUGH FRIDAY. THE SECOND WILL BE IN THE SUNDAY THROUGH MONDAY PERIOD. AN UPPER TROUGH WILL POSITION ITSELF OVER THE INTERMOUNTAIN WEST ON THURSDAY WITH A CLOSED LOW AT THE BASE OF THE TROUGH OVER SOUTHEASTERN UTAH. THE NORTHERN BRANCH OF THROUGH WILL SEND SOME WEAK ENERGY ACROSS...ALONG WITH DEEPENING UPSLOPE FLOW...FOR AN INCREASING CHANCE OF SHOWERS. THE BIGGER EVENT WITH THIS SYSTEM WILL BE THURSDAY NIGHT THROUGH FRIDAY AS THE UPPER LOW KICKS OUT. MODELS AGREE ON TAKING THE SYSTEM INTO THE PLAINS AND POSITIONING IT SOUTHEAST OF RAPID CITY EARLY FRIDAY. MODELS KICK IT NORTHEAST THROUGH THE DAY. THIS WILL SEND THE SURFACE LOW ACROSS THE WESTERN DAKOTAS WITH STRONG SURFACE CONVERGENCE AND QG FORCING OVER THE EASTERN FOUR COUNTIES. RAISED POPS FURTHER. ALSO BUMPED WIND SPEEDS AS THE SYSTEM CRANKS UP. STILL LOOKS TOO WARM FOR SNOW OVER THE LOWER ELEVATIONS. SHOULD SEE ACCUMULATING SNOWFALL OVER THE HIGHER TERRAIN THURSDAY INTO FRIDAY AS THE SYSTEM MOVES ACROSS. THIS SYSTEM WILL KICK NORTHEAST AWAY FROM THE AREA FRIDAY NIGHT AND SET THE STAGE FOR THE NEXT POTENTIAL EVENT SUNDAY INTO MONDAY. MODELS DRIVE ENERGY INTO IDAHO SUNDAY WITH CYCLONIC FLOW AND STRENGTHENING UPSLOPE. THE ECMWF WAS THE DEEPEST WITH THIS SYSTEM AND ACTUALLY CLOSES OFF A LOW OVER CENTRAL IDAHO FOR STRONG ASCENT OVER THE FORECAST AREA. THERMAL PROFILES LOOK COLD ENOUGH FOR SNOW FOR MOST LOCATIONS...EVEN THE PLAINS SUNDAY AND ESPECIALLY SUNDAY NIGHT. THE ECMWF LINGERS THE LOW OVER THE NORTHERN ROCKIES MONDAY AND MONDAY NIGHT...WHILE THE GFS SENDS THE WEAKER TROUGH WITH CYCLONIC FLOW AND ENERGY SINKING SOUTH. THERE WAS A GOOD DEAL OF DIFFERENCE WITH THIS SYSTEM...BUT EITHER WAY...BOTH MODELS GENERATE A SNOW EVENT FOR AT LEAST SUNDAY AND SUNDAY NIGHT. WILL MENTION IN THE HWO. TWH && .AVIATION... MAINLY VFR FLYING WEATHER IS EXPECTED TODAY...THOUGH MOUNTAIN SHOWERS MAY BRING MOUNTAIN OBSCURATION...ESPECIALLY THIS AFTERNOON AND EVENING. WINDS WILL BE LIGHT ACROSS MUCH OF THE AREA...THOUGH WESTERLY GUSTS TO 25 KTS ARE POSSIBLE NEAR KLVM THIS AFTERNOON. STC && .PRELIMINARY POINT TEMP/POPS... TDY WED THU FRI SAT SUN MON ------------------------------------------------------- BIL 062 039/055 039/054 040/052 036/050 036/044 031/043 0/B 23/W 24/W 53/W 21/B 34/W 54/W LVM 057 035/053 035/055 034/048 033/046 030/044 028/042 1/B 22/W 24/W 64/W 22/W 35/W 64/W HDN 062 038/058 038/055 039/054 037/051 036/046 032/044 0/B 23/W 24/W 53/W 21/B 23/W 45/W MLS 065 040/059 039/060 040/055 037/053 035/051 031/047 0/B 03/W 23/W 65/W 20/B 21/B 34/W 4BQ 064 039/059 039/058 039/051 036/050 035/049 032/044 0/B 12/W 13/W 75/W 20/B 11/B 45/W BHK 064 038/059 039/058 041/051 035/050 032/049 029/043 0/B 02/W 13/W 78/W 30/B 21/B 24/W SHR 061 038/057 037/057 037/052 033/048 031/045 028/042 0/B 23/W 24/W 54/W 21/B 22/W 65/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
326 AM MDT TUE OCT 8 2013 .SHORT TERM...VALID FOR TDY AND WED... A GENERALLY BENIGN COLD FRONT CURRENTLY MOVING THROUGH THE AREA WITH WIND SHIFT TO THE N/NW AT LVM-BIL-MLS AS OF 08Z. THIS IS ASSOCIATED WITH SHORTWAVE SKIRTING ACROSS NORTH CENTRAL MT. LOOKING WEST...SATELLITE IMAGERY SHOWS STRONG NORTHERLY JET ALONG THE BC COAST...WITH LATEST RAP ANALYSIS SHOWING 140 KTS AT 300MB. SO AMPLIFICATION OF THE FLOW IS UNDERWAY AS THIS JET WILL ALLOW FOR A LOW TO CUT OFF OVER CA ON WEDNESDAY...WHICH WILL EVENTUALLY BECOME A PLAYER IN OUR REGION BY THURSDAY. CURRENT FRONTAL PASSAGE IS A DRY ONE WITH ONLY SOME MID AND HIGH CLOUD OVER OUR REGION. COMBINATION OF WEAK MID LEVEL FRONTOGENESIS ALONG IDAHO PV MAX AND SOME MODEST DIURNAL HEATING SHOULD ALLOW FOR SOME LIGHT SHOWERS TO DEVELOP OVER OUR SOUTHERN MTNS LATE THIS AFTERNOON...WITH A TURNING OF THE LOW LEVEL FLOW TO NORTH/UPSLOPE HELPING THIS CAUSE. MORE INTERESTING FACET OF THE NEXT 24-36 HOURS IS THE PERIOD OF FAIRLY STRONG/MOIST ISENTROPIC ASCENT FROM THE SOUTH AS LOW DEEPENS TO OUR WEST LATE TONIGHT AND WEDNESDAY. MODELS ARE CONSISTENT IN SHOWING LIFT BUT DIFFER IN STRENGTH OF ASCENT AND PRODUCTION OF QPF. FEEL THAT THE DEPTH OF MID LEVEL FORCING AND MOISTURE...ALONG WITH LOW LEVEL UPSLOPE FLOW...WILL BE ENOUGH FOR SOME LIGHT PCPN AND WILL SUSTAIN CHANCE POPS ON WEDNESDAY. PCPN TYPE WILL BE RAIN AT LOWER ELEVATIONS WITH SOME SNOW ABOVE 7KFT OR SO. MID LEVEL WARM FRONT WHICH SHOULD BE THE FOCUS OF THE PCPN WILL LIFT NORTH OF OUR AREA BY LATE WEDNESDAY AFTERNOON. WILL SUSTAIN LOW POPS FOR WEDNESDAY NIGHT BUT FORCING DOES BECOME MUCH WEAKER AND THIS MAY TURN OUT TO BE A DRY PERIOD...AS WE AWAIT UPPER LOW TO OUR SW. TEMPS WILL TURN BACK BELOW NORMAL THESE NEXT COUPLE DAYS...WITH HIGHS IN THE LOW TO MID 60S TODAY AND IN THE 50S/NEAR 60 ON WEDNESDAY...WITH TEMPS ON THE LATTER DAY POTENTIALLY IMPACTED BY LIGHT PCPN. MONDAY AFTERNOON VISIBLE IMAGERY STILL SHOWED SOME SNOW COVER ALONG THE NORTH SLOPES WHICH WILL HAVE A LITTLE IMPACT ON TEMPS IN THESE AREAS AGAIN TODAY. NOT IN BILLINGS THOUGH...PER SHIFT FROM SW TO NW-N WINDS...SO EXPECT THE CITY TO ACTUALLY REACH ITS POTENTIAL TODAY WITH A HIGH TEMP INTO THE LOW 60S. JKL .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... THE FOCUS FOR THIS EXTENDED PACKAGE WILL BE TWO TIME FRAMES. THE FIRST WILL BE THURSDAY THROUGH FRIDAY. THE SECOND WILL BE IN THE SUNDAY THROUGH MONDAY PERIOD. AN UPPER TROUGH WILL POSITION ITSELF OVER THE INTERMOUNTAIN WEST ON THURSDAY WITH A CLOSED LOW AT THE BASE OF THE TROUGH OVER SOUTHEASTERN UTAH. THE NORTHERN BRANCH OF TROUGH WILL SEND SOME WEAK ENERGY ACROSS...ALONG WITH DEEPENING UPSLOPE FLOW...FOR AN INCREASING CHANCE OF SHOWERS. THE BIGGER EVENT WITH THIS SYSTEM WILL BE THURSDAY NIGHT THROUGH FRIDAY AS THE UPPER LOW KICKS OUT. MODELS AGREE ON TAKING THE SYSTEM INTO THE PLAINS AND POSITIONING IT SOUTHEAST OF RAPID CITY EARLY FRIDAY. MODELS KICK IT NORTHEAST THROUGH THE DAY. THIS WILL SEND THE SURFACE LOW ACROSS THE WESTERN DAKOTAS WITH STRONG SURFACE CONVERGENCE AND QG FORCING OVER THE EASTERN FOUR COUNTIES. RAISED POPS FURTHER. ALSO BUMPED WIND SPEEDS AS THE SYSTEM CRANKS UP. STILL LOOKS TOO WARM FOR SNOW OVER THE LOWER ELEVATIONS. SHOULD SEE ACCUMULATING SNOWFALL OVER THE HIGHER TERRAIN THURSDAY INTO FRIDAY AS THE SYSTEM MOVES ACROSS. THIS SYSTEM WILL KICK NORTHEAST AWAY FROM THE AREA FRIDAY NIGHT AND SET THE STAGE FOR THE NEXT POTENTIAL EVENT SUNDAY INTO MONDAY. MODELS DRIVE ENERGY INTO IDAHO SUNDAY WITH CYCLONIC FLOW AND STRENGTHENING UPSLOPE. THE ECMWF WAS THE DEEPEST WITH THIS SYSTEM AND ACTUALLY CLOSES OFF A LOW OVER CENTRAL IDAHO FOR STRONG ASCENT OVER THE FORECAST AREA. THERMAL PROFILES LOOK COLD ENOUGH FOR SNOW FOR MOST LOCATIONS...EVEN THE PLAINS SUNDAY AND ESPECIALLY SUNDAY NIGHT. THE ECMWF LINGERS THE LOW OVER THE NORTHERN ROCKIES MONDAY AND MONDAY NIGHT...WHILE THE GFS SENDS THE WEAKER TROUGH WITH CYCLONIC FLOW AND ENERGY SINKING SOUTH. THERE WAS A GOOD DEAL OF DIFFERENCE WITH THIS SYSTEM...BUT EITHER WAY...BOTH MODELS GENERATE A SNOW EVENT FOR AT LEAST SUNDAY AND SUNDAY NIGHT. WILL MENTION IN THE HWO. TWH && .AVIATION... A COLD FRONT WAS WORKING ACROSS THE AREA AND BRINGING A SHIFT TO NORTHERLY WINDS. THE WINDS WINDS SHOULD BE NOT STRONG. THERE WILL BE CLOUDS AROUND TODAY BEHIND THE FRONT...BUT THEY SHOULD BE MAINLY ABOVE 8 THOUSAND FEET. VFR FLYING WEATHER EXPECTED. TWH && .PRELIMINARY POINT TEMP/POPS... TDY WED THU FRI SAT SUN MON ------------------------------------------------------- BIL 062 039/055 039/054 040/052 036/050 036/044 031/043 0/B 23/W 24/W 53/W 21/B 34/W 54/W LVM 057 035/053 035/055 034/048 033/046 030/044 028/042 1/B 22/W 24/W 64/W 22/W 35/W 64/W HDN 062 038/058 038/055 039/054 037/051 036/046 032/044 0/B 23/W 24/W 53/W 21/B 23/W 45/W MLS 065 040/059 039/060 040/055 037/053 035/051 031/047 0/B 03/W 23/W 65/W 20/B 21/B 34/W 4BQ 064 039/059 039/058 039/051 036/050 035/049 032/044 0/B 12/W 13/W 75/W 20/B 11/B 45/W BHK 064 038/059 039/058 041/051 035/050 032/049 029/043 0/B 02/W 13/W 78/W 30/B 21/B 24/W SHR 061 038/057 037/057 037/052 033/048 031/045 028/042 0/B 23/W 24/W 54/W 21/B 22/W 65/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1238 PM CDT TUE OCT 8 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 352 AM CDT TUE OCT 8 2013 A BROAD AREA OF SUBTROPICAL MOISTURE FEEDING OFF THE EASTERN PACIFIC IS EXPECTED TO MOVE OVER THE FCST AREA TODAY AND TONIGHT KEEPING SKIES PARTLY CLOUDY. THIS MOISTURE IS BEING SWEPT IN AS AN UPPER LEVEL LOW ACROSS BRITISH COLUMBIA AND ALBERTA DROPS SOUTH INTO THE GREAT BASIN. THE GFS MODEL SEEMS TO HANDLE THESE CLOUDS THE BEST AND WAS THE BASIS FOR THE SKY FORECAST. THE RAP MODEL SHOWS A THERMAL RIDGE WITH H700 MB TEMPS NEAR 10C STATIONARY ACROSS THE FCST AREA THIS AFTN. TEMPERATURES TODAY SHOULD RISE INTO THE 70S TO LOWER 80S EXCEPT OVER THE SNOW FIELD ACROSS NRN SHERIDAN COUNTY WHERE HIGHS WILL TOP OUT IN THE 50S AND 60S. THE NAM SHOWS MIXING HEIGHTS NEAR 800 MB SOUTH AND 850 MB NORTH BUT THE UPPER AIR SOUNDING FROM KLBF LAST NIGHT SHOWED A MIXING TO 750 MB. THIS WAS ABOUT 50 MB HIGHER THAN THE NAM WAS FORECASTING. SO THE FORECAST TRENDS TOWARD THE WARMER MET GUIDANCE WHICH VERIFIED THE BEST MONDAY AFTERNOON. AS THIS UPPER LEVEL LOW DROPS INTO THE GREAT BASIN LATER TODAY...WINDS ALOFT INCREASE AND SFC LOW PRESSURE DEVELOPS ACROSS ERN COLO. THIS WILL HELP PULL A WEAK COLD FRONT PART WAY THROUGH THE FCST AREA. THE RESULT WILL BE THE DEVELOPMENT OF AN INVERTED SFC TROF AND STATIONARY FRONT DRAPED FROM ROUGHLY KSNY TO KVTN. THE FRONT WILL HELP POOL MOISTURE AND DEW POINTS TONIGHT SHOULD RISE INTO THE MID 40S AHEAD OF THE FRONT. LOWS TONIGHT SHOULD FALL INTO THE 40S TO NEAR 50 WITH THIS INCREASE IN MOISTURE. THE NAM MODEL THEN SHOWS A BANK OF STRATUS AND FOG DEVELOPING BEHIND THE FRONT ACROSS NORTHWEST NEB. THIS AREA OF STRATUS AND FOG...IF IT DEVELOPS...SHOULD MIX OUT WEDNESDAY MORNING ACCORDING TO THE MODEL. LASTLY...THE NAM AND RAP MODELS MAINTAIN A SOUTHERLY BELT OF 30 TO 45 KT H850 MB WINDS TODAY ANGLED FROM KMCK TO KONL. THIS SHOULD PRODUCE WINDY CONDITIONS IN THE ERN 1/3 OF THE FCST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 352 AM CDT TUE OCT 8 2013 ANOTHER MILD DAY FOR WEDNESDAY WITH DRY CONDITIONS AND HIGHS FOR MOST OF THE AREA IN THE 70S...COOLER ACROSS THE NW...60S. UPPER LEVEL TROUGH WILL STILL RESIDE ACROSS DESERT SOUTHWEST...WITH SW FLOW ACROSS THE HIGH PLAINS. BY THURSDAY THE AFTERNOON THE LOW WILL PUSH ACROSS THE ROCKIES WITH MODELS SHOWING MORE DIFFERENCES WITH THE EXACT TRACK OF THE LOW FROM YESTERDAY. THE NAM AND THE GEM HAVE A MORE NORTHERLY BIAS...HOWEVER AT THE SFC THE LOW IS FAIRLY SIMILAR...ACROSS NE COLORADO. THE SFC LOW WILL RACE INTO THE DAKOTAS THURSDAY NIGHT AND FRIDAY. MOISTURE POOLS AHEAD OF THE LOW...WITH PWATS REACHING AROUND 1 INCH...WHICH IS 2SD FOR OCTOBER. SPEED SHEAR IS GREAT THROUGH THE COLUMN...WITH DIRECTIONAL SHEAR GOOD ONLY IN THE LOWEST LEVEL. MODELS IN GOOD AGREEMENT WITH THUNDERSTORMS EXPECTED TO FIRE AS THE LOW LIFTS TO THE NE. TIMING LOOKS TO BE MID AFTERNOON THURS TO THURS EVENING. SOME CONCERN WITH DEW PTS ONLY IN THE 50S...HOWEVER FOR OCTOBER...SHOULD BE GOOD FOR SOME SEVERE WEATHER...MAINLY HAIL AND WINDS. ALTHOUGH WITH THE GOOD DIRECTIONAL SHEAR IN THE LOWEST LEVEL NEAR THE TRIPLE POINT...WILL NEED TO MONITOR A POSSIBLE WEAK TORNADO THREAT. ANOTHER CONCERN WILL BE THE SPEED OF THE STORMS. SOUNDINGS SHOW STORM MOTION TO THE NE AROUND 40 MPH. LOW POPS START THURSDAY 18Z TO 21Z AND INCREASE THROUGH THURSDAY EVENING AS STORMS COVERAGE LIKELY INCREASES. OVERNIGHT THE LOW WILL LIFT NE AND WILL NEED TO MONITOR WRAP AROUND AND DRY SLOT...AS BOTH TO IMPACT THE AREA. FRIDAY COOLER TEMPS AS COLD FRONT SWINGS THROUGH ACROSS THE AREA. NO ARCTIC AIR BEHIND THIS FRONT...SO HIGH TEMPS WILL ONLY COOL INTO THE 50S AND 60S. LINGERING RAIN CHANCES POSSIBLE...HOWEVER CONFIDENCE IS NOT ALL THAT HIGH. FRIDAY NIGHT INTO SATURDAY THE MAIN LOW CONTINUES TO LIFT INTO CANADA...WHILE A SECONDARY WEAK TROUGH SLIDES ACROSS THE NRN/CENTRAL ROCKIES. MOISTURE IS LIMITED...HOWEVER CAN NOT RULE OUT A SHOWER ACROSS THE HIGHER TERRAIN OF SW NEB. BY SATURDAY WITH WARMING TEMPS...FROM RETURN SOUTHERLY FLOW...T/TD SPREAD SHOULD RESULT IN ONLY SOME PASSING CLOUDS. SATURDAY NIGHT INTO SUNDAY ZONAL FLOW WITH DRY AND MILD CONDITIONS. THEN ANOTHER WEAK TROUGH ROTATES ACROSS THE ROCKIES. THE GFS CONTINUES TO BRING THIS ACROSS SUNDAY NIGHT INTO MONDAY...WHILE THE EC IS STRONGER AND SLOWER...MONDAY INTO TUES. LOW POPS FOR NOW AND WILL WAIT FOR BETTER AGREEMENT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1237 PM CDT TUE OCT 8 2013 A WEAK FRONTAL BOUNDARY WILL BE LOCATED ACROSS WESTERN NEBRASKA THROUGH MID DAY WEDNESDAY. THE SURFACE LOW WILL BE OVER NORTHEAST COLORADO TODAY...WITH THE FRONT EXTENDING INTO SOUTH CENTRAL SOUTH DAKOTA. THEN ON WEDNESDAY...THE SURFACE LOW IS EXPECTED TO MOVE EAST SLIGHTLY INTO SOUTHWEST NEBRASKA. THIS WILL KEEP WINDS FAIRLY LIGHT AT BOTH KVTN AND KLBF TERMINALS. LOCATIONS TO THE EAST WILL SEE BREEZIER SOUTHERLY WINDS...WHILE PLACES TO THE WEST OF THE BOUNDARY COULD EXPECT WINDS FROM THE WEST TO NORTH. CLOUD COVER WILL PRIMARILY BE SCATTERED HIGH CLOUDS ABOVE 25K FEET. HOWEVER...THERE ARE INDICATIONS OF SOME LOW LEVEL MOISTURE JUST OFF THE SURFACE BEING BROUGHT INTO NORTHWEST NEBRASKA ON THE NORTH SIDE OF THE BOUNDARY. THIS MOISTURE LOOKS TO BE VERY SHALLOW SO CURRENTLY DON/T THINK STRATUS WILL DEVELOP...BUT WINDS MAY STAY HIGH ENOUGH TO PREVENT FOG. CURRENTLY BELIEVE THAT AREAS WITH HIGHEST THREAT FOR FOG WOULD BE OVER THE AREAS WITH SNOWPACK...AS MELTING IS EXPECTED TODAY TO INCREASE THE MOISTURE IN THE BOUNDARY LAYER. BUT AGAIN...WITH WINDS NOT FORECAST TO BECOME CALM IN THESE AREAS...NOT THINKING DENSE FOG IS A HIGH THREAT RIGHT NOW. WILL CONTINUE TO MONITOR FOR COMING FORECASTS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...BROOKS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
640 AM CDT TUE OCT 8 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 352 AM CDT TUE OCT 8 2013 A BROAD AREA OF SUBTROPICAL MOISTURE FEEDING OFF THE EASTERN PACIFIC IS EXPECTED TO MOVE OVER THE FCST AREA TODAY AND TONIGHT KEEPING SKIES PARTLY CLOUDY. THIS MOISTURE IS BEING SWEPT IN AS AN UPPER LEVEL LOW ACROSS BRITISH COLUMBIA AND ALBERTA DROPS SOUTH INTO THE GREAT BASIN. THE GFS MODEL SEEMS TO HANDLE THESE CLOUDS THE BEST AND WAS THE BASIS FOR THE SKY FORECAST. THE RAP MODEL SHOWS A THERMAL RIDGE WITH H700 MB TEMPS NEAR 10C STATIONARY ACROSS THE FCST AREA THIS AFTN. TEMPERATURES TODAY SHOULD RISE INTO THE 70S TO LOWER 80S EXCEPT OVER THE SNOW FIELD ACROSS NRN SHERIDAN COUNTY WHERE HIGHS WILL TOP OUT IN THE 50S AND 60S. THE NAM SHOWS MIXING HEIGHTS NEAR 800 MB SOUTH AND 850 MB NORTH BUT THE UPPER AIR SOUNDING FROM KLBF LAST NIGHT SHOWED A MIXING TO 750 MB. THIS WAS ABOUT 50 MB HIGHER THAN THE NAM WAS FORECASTING. SO THE FORECAST TRENDS TOWARD THE WARMER MET GUIDANCE WHICH VERIFIED THE BEST MONDAY AFTERNOON. AS THIS UPPER LEVEL LOW DROPS INTO THE GREAT BASIN LATER TODAY...WINDS ALOFT INCREASE AND SFC LOW PRESSURE DEVELOPS ACROSS ERN COLO. THIS WILL HELP PULL A WEAK COLD FRONT PART WAY THROUGH THE FCST AREA. THE RESULT WILL BE THE DEVELOPMENT OF AN INVERTED SFC TROF AND STATIONARY FRONT DRAPED FROM ROUGHLY KSNY TO KVTN. THE FRONT WILL HELP POOL MOISTURE AND DEW POINTS TONIGHT SHOULD RISE INTO THE MID 40S AHEAD OF THE FRONT. LOWS TONIGHT SHOULD FALL INTO THE 40S TO NEAR 50 WITH THIS INCREASE IN MOISTURE. THE NAM MODEL THEN SHOWS A BANK OF STRATUS AND FOG DEVELOPING BEHIND THE FRONT ACROSS NORTHWEST NEB. THIS AREA OF STRATUS AND FOG...IF IT DEVELOPS...SHOULD MIX OUT WEDNESDAY MORNING ACCORDING TO THE MODEL. LASTLY...THE NAM AND RAP MODELS MAINTAIN A SOUTHERLY BELT OF 30 TO 45 KT H850 MB WINDS TODAY ANGLED FROM KMCK TO KONL. THIS SHOULD PRODUCE WINDY CONDITIONS IN THE ERN 1/3 OF THE FCST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 352 AM CDT TUE OCT 8 2013 ANOTHER MILD DAY FOR WEDNESDAY WITH DRY CONDITIONS AND HIGHS FOR MOST OF THE AREA IN THE 70S...COOLER ACROSS THE NW...60S. UPPER LEVEL TROUGH WILL STILL RESIDE ACROSS DESERT SOUTHWEST...WITH SW FLOW ACROSS THE HIGH PLAINS. BY THURSDAY THE AFTERNOON THE LOW WILL PUSH ACROSS THE ROCKIES WITH MODELS SHOWING MORE DIFFERENCES WITH THE EXACT TRACK OF THE LOW FROM YESTERDAY. THE NAM AND THE GEM HAVE A MORE NORTHERLY BIAS...HOWEVER AT THE SFC THE LOW IS FAIRLY SIMILAR...ACROSS NE COLORADO. THE SFC LOW WILL RACE INTO THE DAKOTAS THURSDAY NIGHT AND FRIDAY. MOISTURE POOLS AHEAD OF THE LOW...WITH PWATS REACHING AROUND 1 INCH...WHICH IS 2SD FOR OCTOBER. SPEED SHEAR IS GREAT THROUGH THE COLUMN...WITH DIRECTIONAL SHEAR GOOD ONLY IN THE LOWEST LEVEL. MODELS IN GOOD AGREEMENT WITH THUNDERSTORMS EXPECTED TO FIRE AS THE LOW LIFTS TO THE NE. TIMING LOOKS TO BE MID AFTERNOON THURS TO THURS EVENING. SOME CONCERN WITH DEW PTS ONLY IN THE 50S...HOWEVER FOR OCTOBER...SHOULD BE GOOD FOR SOME SEVERE WEATHER...MAINLY HAIL AND WINDS. ALTHOUGH WITH THE GOOD DIRECTIONAL SHEAR IN THE LOWEST LEVEL NEAR THE TRIPLE POINT...WILL NEED TO MONITOR A POSSIBLE WEAK TORNADO THREAT. ANOTHER CONCERN WILL BE THE SPEED OF THE STORMS. SOUNDINGS SHOW STORM MOTION TO THE NE AROUND 40 MPH. LOW POPS START THURSDAY 18Z TO 21Z AND INCREASE THROUGH THURSDAY EVENING AS STORMS COVERAGE LIKELY INCREASES. OVERNIGHT THE LOW WILL LIFT NE AND WILL NEED TO MONITOR WRAP AROUND AND DRY SLOT...AS BOTH TO IMPACT THE AREA. FRIDAY COOLER TEMPS AS COLD FRONT SWINGS THROUGH ACROSS THE AREA. NO ARCTIC AIR BEHIND THIS FRONT...SO HIGH TEMPS WILL ONLY COOL INTO THE 50S AND 60S. LINGERING RAIN CHANCES POSSIBLE...HOWEVER CONFIDENCE IS NOT ALL THAT HIGH. FRIDAY NIGHT INTO SATURDAY THE MAIN LOW CONTINUES TO LIFT INTO CANADA...WHILE A SECONDARY WEAK TROUGH SLIDES ACROSS THE NRN/CENTRAL ROCKIES. MOISTURE IS LIMITED...HOWEVER CAN NOT RULE OUT A SHOWER ACROSS THE HIGHER TERRAIN OF SW NEB. BY SATURDAY WITH WARMING TEMPS...FROM RETURN SOUTHERLY FLOW...T/TD SPREAD SHOULD RESULT IN ONLY SOME PASSING CLOUDS. SATURDAY NIGHT INTO SUNDAY ZONAL FLOW WITH DRY AND MILD CONDITIONS. THEN ANOTHER WEAK TROUGH ROTATES ACROSS THE ROCKIES. THE GFS CONTINUES TO BRING THIS ACROSS SUNDAY NIGHT INTO MONDAY...WHILE THE EC IS STRONGER AND SLOWER...MONDAY INTO TUES. LOW POPS FOR NOW AND WILL WAIT FOR BETTER AGREEMENT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 638 AM CDT TUE OCT 8 2013 WINDS ALOFT WILL CONTINUE TO INCREASE TODAY AND TONIGHT AND THIS WILL PRODUCE SOME HIGH CLOUDINESS. THESE STRONG WINDS WILL ALSO DEVELOP A LOW PRESSURE SYSTEM ACROSS ERN COLO TONIGHT. THE LOW WILL CAUSE A WEAK COLD FRONT TO DROP THROUGH NORTHWEST NEB...INCLUDING KVTN. THE NAM MODEL SUGGESTS IFR CIGS/VSBY ACROSS THE NORTHWEST AFTER 06Z TONIGHT BEHIND THE FRONT. GIVEN THE TENDENCY FOR THE NAM TO OVERFORECAST AT TIMES...IT WOULD BE BEST TO WAIT ON THE RAP MODEL FOR CONFORMATION. VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
352 AM CDT TUE OCT 8 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 352 AM CDT TUE OCT 8 2013 A BROAD AREA OF SUBTROPICAL MOISTURE FEEDING OFF THE EASTERN PACIFIC IS EXPECTED TO MOVE OVER THE FCST AREA TODAY AND TONIGHT KEEPING SKIES PARTLY CLOUDY. THIS MOISTURE IS BEING SWEPT IN AS AN UPPER LEVEL LOW ACROSS BRITISH COLUMBIA AND ALBERTA DROPS SOUTH INTO THE GREAT BASIN. THE GFS MODEL SEEMS TO HANDLE THESE CLOUDS THE BEST AND WAS THE BASIS FOR THE SKY FORECAST. THE RAP MODEL SHOWS A THERMAL RIDGE WITH H700 MB TEMPS NEAR 10C STATIONARY ACROSS THE FCST AREA THIS AFTN. TEMPERATURES TODAY SHOULD RISE INTO THE 70S TO LOWER 80S EXCEPT OVER THE SNOW FIELD ACROSS NRN SHERIDAN COUNTY WHERE HIGHS WILL TOP OUT IN THE 50S AND 60S. THE NAM SHOWS MIXING HEIGHTS NEAR 800 MB SOUTH AND 850 MB NORTH BUT THE UPPER AIR SOUNDING FROM KLBF LAST NIGHT SHOWED A MIXING TO 750 MB. THIS WAS ABOUT 50 MB HIGHER THAN THE NAM WAS FORECASTING. SO THE FORECAST TRENDS TOWARD THE WARMER MET GUIDANCE WHICH VERIFIED THE BEST MONDAY AFTERNOON. AS THIS UPPER LEVEL LOW DROPS INTO THE GREAT BASIN LATER TODAY...WINDS ALOFT INCREASE AND SFC LOW PRESSURE DEVELOPS ACROSS ERN COLO. THIS WILL HELP PULL A WEAK COLD FRONT PART WAY THROUGH THE FCST AREA. THE RESULT WILL BE THE DEVELOPMENT OF AN INVERTED SFC TROF AND STATIONARY FRONT DRAPED FROM ROUGHLY KSNY TO KVTN. THE FRONT WILL HELP POOL MOISTURE AND DEW POINTS TONIGHT SHOULD RISE INTO THE MID 40S AHEAD OF THE FRONT. LOWS TONIGHT SHOULD FALL INTO THE 40S TO NEAR 50 WITH THIS INCREASE IN MOISTURE. THE NAM MODEL THEN SHOWS A BANK OF STRATUS AND FOG DEVELOPING BEHIND THE FRONT ACROSS NORTHWEST NEB. THIS AREA OF STRATUS AND FOG...IF IT DEVELOPS...SHOULD MIX OUT WEDNESDAY MORNING ACCORDING TO THE MODEL. LASTLY...THE NAM AND RAP MODELS MAINTAIN A SOUTHERLY BELT OF 30 TO 45 KT H850 MB WINDS TODAY ANGLED FROM KMCK TO KONL. THIS SHOULD PRODUCE WINDY CONDITIONS IN THE ERN 1/3 OF THE FCST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 352 AM CDT TUE OCT 8 2013 ANOTHER MILD DAY FOR WEDNESDAY WITH DRY CONDITIONS AND HIGHS FOR MOST OF THE AREA IN THE 70S...COOLER ACROSS THE NW...60S. UPPER LEVEL TROUGH WILL STILL RESIDE ACROSS DESERT SOUTHWEST...WITH SW FLOW ACROSS THE HIGH PLAINS. BY THURSDAY THE AFTERNOON THE LOW WILL PUSH ACROSS THE ROCKIES WITH MODELS SHOWING MORE DIFFERENCES WITH THE EXACT TRACK OF THE LOW FROM YESTERDAY. THE NAM AND THE GEM HAVE A MORE NORTHERLY BIAS...HOWEVER AT THE SFC THE LOW IS FAIRLY SIMILAR...ACROSS NE COLORADO. THE SFC LOW WILL RACE INTO THE DAKOTAS THURSDAY NIGHT AND FRIDAY. MOISTURE POOLS AHEAD OF THE LOW...WITH PWATS REACHING AROUND 1 INCH...WHICH IS 2SD FOR OCTOBER. SPEED SHEAR IS GREAT THROUGH THE COLUMN...WITH DIRECTIONAL SHEAR GOOD ONLY IN THE LOWEST LEVEL. MODELS IN GOOD AGREEMENT WITH THUNDERSTORMS EXPECTED TO FIRE AS THE LOW LIFTS TO THE NE. TIMING LOOKS TO BE MID AFTERNOON THURS TO THURS EVENING. SOME CONCERN WITH DEW PTS ONLY IN THE 50S...HOWEVER FOR OCTOBER...SHOULD BE GOOD FOR SOME SEVERE WEATHER...MAINLY HAIL AND WINDS. ALTHOUGH WITH THE GOOD DIRECTIONAL SHEAR IN THE LOWEST LEVEL NEAR THE TRIPLE POINT...WILL NEED TO MONITOR A POSSIBLE WEAK TORNADO THREAT. ANOTHER CONCERN WILL BE THE SPEED OF THE STORMS. SOUNDINGS SHOW STORM MOTION TO THE NE AROUND 40 MPH. LOW POPS START THURSDAY 18Z TO 21Z AND INCREASE THROUGH THURSDAY EVENING AS STORMS COVERAGE LIKELY INCREASES. OVERNIGHT THE LOW WILL LIFT NE AND WILL NEED TO MONITOR WRAP AROUND AND DRY SLOT...AS BOTH TO IMPACT THE AREA. FRIDAY COOLER TEMPS AS COLD FRONT SWINGS THROUGH ACROSS THE AREA. NO ARCTIC AIR BEHIND THIS FRONT...SO HIGH TEMPS WILL ONLY COOL INTO THE 50S AND 60S. LINGERING RAIN CHANCES POSSIBLE...HOWEVER CONFIDENCE IS NOT ALL THAT HIGH. FRIDAY NIGHT INTO SATURDAY THE MAIN LOW CONTINUES TO LIFT INTO CANADA...WHILE A SECONDARY WEAK TROUGH SLIDES ACROSS THE NRN/CENTRAL ROCKIES. MOISTURE IS LIMITED...HOWEVER CAN NOT RULE OUT A SHOWER ACROSS THE HIGHER TERRAIN OF SW NEB. BY SATURDAY WITH WARMING TEMPS...FROM RETURN SOUTHERLY FLOW...T/TD SPREAD SHOULD RESULT IN ONLY SOME PASSING CLOUDS. SATURDAY NIGHT INTO SUNDAY ZONAL FLOW WITH DRY AND MILD CONDITIONS. THEN ANOTHER WEAK TROUGH ROTATES ACROSS THE ROCKIES. THE GFS CONTINUES TO BRING THIS ACROSS SUNDAY NIGHT INTO MONDAY...WHILE THE EC IS STRONGER AND SLOWER...MONDAY INTO TUES. LOW POPS FOR NOW AND WILL WAIT FOR BETTER AGREEMENT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1151 PM CDT MON OCT 7 2013 VFR FLIGHT CONDS ARE EXPECTED OVER THE NEXT 24 HOURS. SOME SCATTERED HIGH CLOUDINESS AON 25000 FT AGL IS POSSIBLE AT BOTH THE KVTN AND KLBF TERMINALS TONIGHT THROUGH TUESDAY EVENING. WINDS WILL BE FROM THE SOUTH OR SOUTHWEST AT AROUND 10 KTS TONIGHT...INCREASING TO 10 TO 20 KTS ON TUESDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1029 PM EDT WED OCT 9 2013 .SYNOPSIS... HIGH PRESSURE OVER THE NORTHEAST UNITED STATES TONIGHT WILL GIVE WAY TO A LOW PRESSURE SYSTEM MOVING UP ALONG THE EAST COAST THURSDAY INTO FRIDAY, BRINGING A CHANCE OF SHOWERS TO THE AREA. THE BEST CHANCE FOR SHOWERS WILL BE ACROSS NORTHEAST PENNSYLVANIA AND THE CATSKILLS. EXPECT TEMPERATURES TO REMAIN ABOVE NORMAL FOR EARLY TO MID OCTOBER INTO THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... 1020 PM UPDATE... FORECAST IN GOOD SHAPE. LATEST HRRR STILL SUPPORTS A DRY OVERNIGHT...WITH A FEW SHOWERS POSSIBLE TOWARD 15Z FAR SOUTH. THIS MATCHES UP WELL WITH THE CURRENT FORECAST SO LITTLE TO CHANGE. ALSO LEFT IN THE MENTION OF PATCHY FOG IN THE VALLEYS. WHILE THE CIRRUS SHIELD IS ALREADY OVERHEAD...IT IS NOT VERY THICK WITH THE STARS STILL VISIBLE. IT TAKES A LOT TO NOT HAVE FOG IN OUR RIVER VALLEYS SO FOR NOW PATCHY FOG LOOKS REASONABLE. THE PREVIOUS AFD IS BELOW... FOR THE REST OF THE AFTERNOON...WE EXPECT TO SEE CONTINUED HIGH LEVEL MOISTURE ADVECTION FROM THE MIDDLE ATLANTIC LOW SUPPORT MORE CIRRUS INTO NY AND PA WHICH WILL THIN OUT AS IT WORKS INTO A REGION OF UPPER LEVEL SUBSDC. THIS SUBSDC WAS SUPPORTG A LL ANTICYCLONE OVER THE NORTHEAST U.S. WITH SUBSBC...850-925 MB TEMPS CONT TO WARM AND WILL BE IN THE LOW TO MID 50S (F) THIS PM. THE SFC LAYER REMAINS FAIRLY DRY WITH DEWPOINTS ONLY THE UPPER 30S AND 40S. THIS COLLABORATES THE MODEL SOUNDING DATA WHICH SUGGEST NO CUMULUS FORMS WITH THE DAY/S HEATING. HENCE ALL WE WILL HAVE IN THE SKY GRIDS IS RELATED TO THINNING CI. CIRRUS WILL BE THICKEST IN NE PA IN CLOSER PROXIMITY TO THE MID ATLANTIC SYSTEM. OTHERWISE A MILD FALL DAY WITH FILTERED SUNSHINE. FOR TONIGHT...WEAK MID ATLANTIC CYCLONE CONTINUES TO SLOWLY WORK NORTHWARD AS PER ALL SYNOPTIC AND MESOSCALE MODEL GUIDC. THIS FEATURE SUPPORTS A FAIRLY STRG LL ERLY JET DUE TO THE STRG HIGH PRESSURE SYSTEM TO THE NE WHICH IS ENHANCING THE PRES GRAD. HENCE WE HAVE A WEAK SFC LOW OFF THE MID ATLANTIC COAST WITH A PRETTY DECENT PRESSURE GRADIENT TO THE NORTH. THIS WILL LEAD TO DECENT MOISTURE ADVECTIONS INTO NE PA BEGINNING LATE TONIGHT...BUT GIVEN THAT THE LOWER AMS BEGINS VERY DRY WE DON/T SEE MUCH IF ANY PRECIP REACHING NE PA B4 12Z THU. SO MID TO HI CLDS WILL STREAM NORTHWARD INTO NE PA AND THIN OUT OVERNGT AS THEY WORK INTO C NY. THERE LIKELY WILL BE VALLEY FOG FORMING IN C NY WHERE MOSTLY CLR SKIES WILL PREDOMINATE AND LIGHT WINDS...BUT IT WON/T BE AS EXTENSIVE AS THIS MORNING/S FOG. BY LATER THU...850 MB JET AS PER GFS...EURO AND CMC MOVES TO THE NORTH OF THIS ADVANCING CYCLONE AND REACHES ACRS ALL OF NE PA/CATSKILLS AND INTO SC NY. THE NAM CONTS TO BE THE ODD MODEL OUT KEEPING THE BEST MOISTURE ADVTNS AND ALL QPF TO THE SOUTH B4 00Z FRI. THINK PRECIP WILL CREEP NORTHWARD AND DRY OUT THU PM BUT SOME LIGHT PRECIP WILL POTENTIALLY REACH INTO NE PA BY LATE THU. THERE IS UNCERTAINTY AS TO HOW FAR N AND W THE PRECIP MAKES IT INTO SC NY THU PM GIVEN THE DRY LL/S SO BASICALLY HAVE DROPPED POPS IN C NY UNTIL THU NGT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... MID-ATLANTIC CYCLONE SLOWLY WORKS NORTHWARD REACHING OFF THE VA/NC COAST BY 12Z FRI ON THE CMC...EURO AND GFS. THE NAM CONTS TO BE THE OUTLIER WITH THE SFC LOW AND ASSCTD UPPER LOW MUCH FARTHER S ONLY REACHING OFF THE SC COAST AT THE SAME TIME. SINCE THE GFS/EURO AND CMC HAVE BEEN CONSISTENT ALL SHOW SOME LIGHT PRECIP REACHING INTO NE PA AND THE CATSKILLS THU NGT...ESP LATER AT NGT. AS SUCH HAVE GRADUALLY RAMPED POPS UP THU NGT FRM CHC TO LIKELY IN THE POCONOS BTWN 00Z AND 12Z FRI AND FROM BELOW 15 PCT TO CHC MOST OF REST OF CWA AND REACHING UP TO SLGHT CHC IN OUR FAR NW COUNTIES MAINLY ACROSS THE FINGER LAKES TO UPPER MOHAWK THU NGT. FRIDAY THE CYCLONE THEN BEGINS TO PUSH BACK TO THE SOUTH SLOWLY. THIS IS IN RESPONSE TO AN UPPER LEVEL WAVE WHICH DROPS SOUTHWARD ACRS SERN CANADA AND RE-ENFORCES LL HIGH PRESSURE ACRS THE NE U.S AND SERN CANADA IT IS WAKE ON FROM FRI INTO SAT. HENCE POPS PEAK FRI PM FROM SLGHT CHC NW ZONES TO CHC/LIKELY IN THE SERN ZONES. THEN I HAVE POPS TRENDING BACK DOWN FRI NGT THRU SAT AS THE UPPER LEVEL LOW IS PUSHED SOUTHWARD. FOR QPF POTENTIALLY UP TO 1/2 TO 1 INCH WHICH SHUD NOT CAUSE ANY HYDRO ISSUES MAINLY POCONOS-CATSKILLS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... STILL SOME MODEL DISAGREEMENT TO START OUT THE EXTENDED TIME FRAME WITH RESPECT TO POTENTIAL IMPACTS ACROSS OUR REGION FROM CLOSED LOW PRESSURE CENTER PERSISTING OFF THE MID-ATLANTIC COAST. GFS AND CANADIAN-CMC CONTINUE TO SHOW THE FEATURE GRADUALLY DEFLECTING TO THE SOUTH AS WEAK SHORTWAVE RIDGING BUILDS OVER THE NORTHEAST THIS WEEKEND. THE ECMWF ON THE OTHER HAND SHOWS A FURTHER NORTHWARD POSITION WITH POSSIBLE SHWR ACTIVITY PERSISTING ACROSS OUR REGION THROUGH EARLY NEXT WEEK BEFORE A WEAK COLD FRONT MOVES THROUGH THE AREA BY LATE MONDAY/EARLY TUESDAY TIMEFRAME. FOR NOW...WILL ADVERTISE SLGT CHC POPS ACROSS THE FAR SOUTH AND SOUTHEAST AT THE START OF THE PERIOD BEFORE INCREASING POPS REGION WIDE BY MONDAY IN ANTICIPATION OF AFOREMENTIONED FRONT. WX BECOMES A BIT MORE INTERESTING BY TUESDAY/WEDNESDAY AS A STRONG STORM SYSTEM SHIFTING EAST FROM THE CENTRAL/NORTHERN PLANS REGION LIFTS A WARM FRONT NORTH THROUGH THE AREA. FROM THIS VANTAGE POINT...STORM SYSTEM APPEARS FAIRLY WELL SUPPORTED WITH STRONG DYNAMICS ALOFT AND HAVE INCREASED POPS INTO THE CHC CATEGORY BY MIDWEEK BASED ON FAVORABLE AGREEMENT BETWEEN THE ECMWF AND GFS. THAT SAID...SOME DISAGREEMENTS WITH 12Z MODEL SUITE AND FROPA TIMING...HOWEVER INDICATIONS SUGGEST A REGION WIDE RAIN EVENT WILL BE POSSIBLE BY MIDWEEK AS STORM SYSTEM MOVES EAST WITH TIME. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... 00Z UPDATE... VFR THROUGH THE TAF PERIOD FOR ALL TERMINALS...WITH ONE POSSIBLE EXCEPTION. NUMERICAL MODEL GUIDANCE IS LIKELY OVERFORECASTING THE AMOUNT EARLY MORNING VALLEY FOG AT KELM...CONSIDERING VERY BROAD SHIELD OF HIGH CIRRUS CLOUDS NOW OVERSPREADING THE AREA...THICKER THAN PREVIOUSLY EXPECTED. THAT BEING SAID...EVEN THE LIMITED RADIATIONAL COOLING OVERNIGHT MAY BE ENOUGH FOR AT LEAST SOME VALLEY FOG. I HAVE BACKED OFF ON AMOUNT OF FOG COMPARED TO MODELS AND ANALOG COMPARISONS...BUT FOR NOW I STILL ALLOW FOR A TEMPO GROUP BELOW ALT MINS 09Z-12Z. CONFIDENCE IN IT OCCURRING IS NOT VERY HIGH...AND TRENDS IN DEWPOINT DEPRESSION WILL BE MONITORED TO HELP WITH DECISION OF WHETHER OR NOT TO KEEP IN FORECAST. OTHERWISE...LOOKING AT CLOUD COVER DURING THE DAY MAINLY ABOVE THE 10 KFT AGL LEVEL /PERHAPS SLIGHTLY BELOW KAVP/ AS UPPER LOW IN THE MIDATLANTIC STATES CREEPS SLOWLY CLOSER TO OUR VICINITY. WINDS VARIABLE OR SOME VERSION OF EASTERLY AT GENERALLY LESS THAN 5 KTS THROUGH THE PERIOD. OUTLOOK... THU NGT-MON...VFR WITH THE EXCEPTION OF POTENTIAL VALLEY FOG ACROSS THE TWIN TIERS EACH MORNING OVER THE WEEKEND /MAINLY IMPACTING KELM/. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJN NEAR TERM...DJN/HEDEN SHORT TERM...DJN LONG TERM...CMG AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
736 AM EDT TUE OCT 8 2013 .SYNOPSIS... FOLLOWING THE COLD FRONTAL PASSAGE YESTERDAY EVENING...COOLER AND DRIER AIR IS FILTERING INTO THE NORTH COUNTRY THIS MORNING ON NORTHWESTERLY WINDS. LINGERING STRATUS CLOUDS THIS MORNING WILL GIVE WAY TO FULL SUNSHINE AS HIGH PRESSURE BUILDS EASTWARD FROM THE GREAT LAKES REGION. STATIONARY HIGH PRESSURE THROUGH A DEEP-LAYER OF THE ATMOSPHERE WILL PROVIDE AN EXTENDED PERIOD OF TRANQUIL WEATHER ACROSS THE NORTH COUNTRY THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL BE NEAR AVERAGE TODAY...AND THEN MODERATE BACK ABOVE AVERAGE THROUGH THE NEXT SEVEN DAYS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 730 AM EDT TUESDAY...QUICK UPDATE FOR DIMINISHING CLOUD TRENDS FROM WEST TO EAST AND TO ADJUST FOR CURRENT TEMPS. REMAINDER OF THE FORECAST REMAINS UNCHANGED. PREVIOUS DISCUSSION...STRATUS DECK REMAINS EARLY THIS MORNING IN FRONTAL INVERSION LAYER BETWEEN 3-5 KFT...WITH SOME LOWER CLOUDS HGTS VCNTY MTNS WITH OROGRAPHIC INFLUENCES. COMBINATION OF DRY ADVECTION AND INCREASING SUBSIDENCE AS SFC HIGH BUILDS EAST FROM THE GREAT LAKES SHOULD DISSIPATE THESE REMAINING CLOUDS BY MID- MORNING...WITH CLOUDS LINGERING LATEST VCNTY OF THE ADIRONDACKS AND N-CENTRAL/NERN VT. A FEW FAIR WX CU WILL DOT THE HIGHER TERRAIN DURING THE AFTN HOURS...BUT SKIES WILL OTHERWISE BE SUNNY. SHOULD BE ABOUT 20 DEGREES COOLER THAN YESTERDAY AT BTV...60F OR SO AFTER HITTING 80 YESTERDAY. WINDS WILL CONTINUE FROM THE NW AROUND 10 MPH...DIMINISHING TOWARD SUNSET AS BOUNDARY LAYER STABILIZES. CLEAR AND CALM TONIGHT WITH CENTER OF SFC ANTICYCLONE BUILDING OVER THE NORTH COUNTRY. GOOD RADIATIVE COOLING AND RECENT RAINFALL WILL LEAD TO FOG IN THE FAVORED VALLEY LOCATIONS 06-14Z WEDNESDAY. MAY SEE A FEW PATCHES OF FROST IN THE CHAMPLAIN VALLEY WHERE GROWING SEASON REMAINS ACTIVE. MARGINAL FROST ADVISORY CONDITIONS IN SPOTS BASED ON LOW TEMPS 35-38F...AND AROUND 40F ON GRAND ISLE WITH MODERATING INFLUENCE OF WARM LAKE TEMPERATURES. INCLUDED PATCHY FROST FOR THOSE ISOLATED SPOTS AWAY FROM LAKE CHAMPLAIN WITH MIN TEMPS FORECAST AT 36F OR LESS. TEMPERATURES WILL BE COLDEST IN THE ADIRONDACKS AND NORTHEAST KINGDOM WITH LOWS THERE IN THE UPR 20S TO LOWER 30S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 309 AM EDT TUESDAY...SYNOPTICALLY QUIESCENT CONDITIONS PREVAIL WITH DEEP-LAYER RIDGE IN PLACE. USED BLEND OF MOS CONSENSUS AND BIAS-CORRECTED MOS CONSENSUS ON TEMPERATURES...WHICH SHOULD MODERATE THRU THE PERIOD. LOOKING FOR HIGHS MID 60S WED AND UPR 60S THU FOR MOST VALLEY LOCATIONS. LOWS WEDNESDAY NIGHT WILL RANGE WIDELY UNDER GOOD RADIATIONAL COOLING CONDITIONS...FROM NEAR 30F AT SLK/ESSEX COUNTY TO THE UPR 30S/LOWER 40S ELSEWHERE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 410 AM EDT TUESDAY...OVERALL VERY QUIET DAYS 4 THRU 7 ANTICIPATED WITH ABOVE NORMAL TEMPS AND BLW NORMAL CHCS FOR PRECIP. LARGE SCALE PATTERN WL FEATURE BUILDING MID/UPPER LVL RIDGE AND ASSOCIATED SFC HIGH PRES ACRS THE NE CONUS. SEVERAL WEAK FEATURES WL HAVE TO BE WATCHED FOR POTENTIAL MINOR IMPACTS ACRS OUR CWA THRU THE TIME PERIOD. FIRST WL BE WEAK AREA OF LOW PRES ALONG THE EASTERN SEABOARD ON FRI-SAT...WHICH COULD SPREAD CLOUDS AND COOLER EASTERLY FLW INTO OUR REGION...ALONG WITH A CHC FOR SOME LIGHT PRECIP. BOTH ECMWF/GFS SHOW BEST LIFT/MOISTURE SOUTH OF OUR CWA THOUGH. NEXT FEATURE IS A WEAK BACKDOOR SFC COLD FRONT ON SAT AFTN/EVENING...WHICH WL PRODUCE COOLER TEMPS AND MAYBE A SPRINKLE ACRS THE NEK OF VERMONT. PROGGED 85H TEMPS START BTWN 10-12C FOR FRIDAY...BUT FALL BTWN 6-8C BY 06Z SUNDAY ACRS EASTERN VT. WL MENTION SLIGHTLY COOLER TEMPS...BUT STILL WELL ABOVE NORMAL. OTHERWISE...RIDGE ALOFT REBUILDS FOR SUNDAY/MONDAY...BEFORE NEXT WEEK SFC ARRIVES BY EARLY NEXT WEEK. BOTH ECMWF/GFS SHOW A WEAK RIBBON OF ENHANCED MOISTURE/LIFT...SO WL MENTION SCHC/CHC POPS...MAINLY ACRS NNY. OTHERWISE...TEMPS WL RANGE MAINLY IN THE 60S TO NEAR 70F WITH LOWS IN THE 40S TO NEAR 50F THRU THE PERIOD. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... THROUGH 06Z WEDNESDAY...AVIATION CHALLENGE WL BE CIGS THRU THIS MORNING...ALONG WITH WINDS. SFC ANALYSIS PLACES SECONDARY COLD FRNT ACRS THE CPV ATTM...WITH BREEZY WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS. THIS UPSLOPE FLW AND LEFTOVER MOISTURE...COMBINED WITH LLVL CAA WL HELP IN THE DEVELOPMENT OF MVFR WITH A PERIOD OF IFR CIGS AT SLK THIS MORNING...BASED ON RAP 13 RH PROFILES. LATEST 3.9 SATL TRENDS SHOW CLOUDS REDEVELOPING ACRS THE OTTAWA VALLEY AND SLV ATTM...WHICH WL MOVE INTO THE DACKS AND THE REST OF OUR CWA THRU EARLY THIS MORNING. HOWEVER...AS SFC HIGH PRES LOCATED OVER THE OHIO VALLEY BUILDS INTO THE REGION...DRIER AIR ADVECTS ACRS OUR TAF SITES RESULTING IN VFR CONDITIONS BY 15Z. STILL THINKING SOME UPSLOPE CLOUDS WL LINGER AT SLK/MPV THRU THIS MORNING...WITH WEST WINDS AT 5 TO 10 KNTS. EXPECT CLR SKIES WITH LIGHT WINDS BY EVENING WITH AREAS OF FOG DEVELOPING BTWN 04-06Z...ESPECIALLY AT SLK/MPV. OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...A BUILDING RIDGE OF HIGH PRES BOTH ALOFT AND AT THE SFC WL RESULT IN VFR CONDITIONS THRU SATURDAY...WITH EXCEPTION OF IFR/LIFR IN MORNING FOG/BR...ESPECIALLY AT MPV/SLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS SHORT TERM...BANACOS LONG TERM...TABER AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
315 AM EDT TUE OCT 8 2013 .SYNOPSIS... FOLLOWING THE COLD FRONTAL PASSAGE YESTERDAY EVENING...COOLER AND DRIER AIR IS FILTERING INTO THE NORTH COUNTRY THIS MORNING ON NORTHWESTERLY WINDS. LINGERING STRATUS CLOUDS THIS MORNING WILL GIVE WAY TO FULL SUNSHINE AS HIGH PRESSURE BUILDS EASTWARD FROM THE GREAT LAKES REGION. STATIONARY HIGH PRESSURE THROUGH A DEEP-LAYER OF THE ATMOSPHERE WILL PROVIDE AN EXTENDED PERIOD OF TRANQUIL WEATHER ACROSS THE NORTH COUNTRY THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL BE NEAR AVERAGE TODAY...AND THEN MODERATE BACK ABOVE AVERAGE THROUGH THE NEXT SEVEN DAYS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 309 AM EDT TUESDAY...STRATUS DECK REMAINS EARLY THIS MORNING IN FRONTAL INVERSION LAYER BETWEEN 3-5 KFT...WITH SOME LOWER CLOUDS HGTS VCNTY MTNS WITH OROGRAPHIC INFLUENCES. COMBINATION OF DRY ADVECTION AND INCREASING SUBSIDENCE AS SFC HIGH BUILDS EAST FROM THE GREAT LAKES SHOULD DISSIPATE THESE REMAINING CLOUDS BY MID-MORNING...WITH CLOUDS LINGERING LATEST VCNTY OF THE ADIRONDACKS AND N-CENTRAL/NERN VT. A FEW FAIR WX CU WILL DOT THE HIGHER TERRAIN DURING THE AFTN HOURS...BUT SKIES WILL OTHERWISE BE SUNNY. SHOULD BE ABOUT 20 DEGREES COOLER THAN YESTERDAY AT BTV...60F OR SO AFTER HITTING 80 YESTERDAY. WINDS WILL CONTINUE FROM THE NW AROUND 10 MPH...DIMINISHING TOWARD SUNSET AS BOUNDARY LAYER STABILIZES. CLEAR AND CALM TONIGHT WITH CENTER OF SFC ANTICYCLONE BUILDING OVER THE NORTH COUNTRY. GOOD RADIATIVE COOLING AND RECENT RAINFALL WILL LEAD TO FOG IN THE FAVORED VALLEY LOCATIONS 06-14Z WEDNESDAY. MAY SEE A FEW PATCHES OF FROST IN THE CHAMPLAIN VALLEY WHERE GROWING SEASON REMAINS ACTIVE. MARGINAL FROST ADVISORY CONDITIONS IN SPOTS BASED ON LOW TEMPS 35-38F...AND AROUND 40F ON GRAND ISLE WITH MODERATING INFLUENCE OF WARM LAKE TEMPERATURES. INCLUDED PATCHY FROST FOR THOSE ISOLATED SPOTS AWAY FROM LAKE CHAMPLAIN WITH MIN TEMPS FORECAST AT 36F OR LESS. TEMPERATURES WILL BE COLDEST IN THE ADIRONDACKS AND NORTHEAST KINGDOM WITH LOWS THERE IN THE UPR 20S TO LOWER 30S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 309 AM EDT TUESDAY...SYNOPTICALLY QUIESCENT CONDITIONS PREVAIL WITH DEEP-LAYER RIDGE IN PLACE. USED BLEND OF MOS CONSENSUS AND BIAS-CORRECTED MOS CONSENSUS ON TEMPERATURES...WHICH SHOULD MODERATE THRU THE PERIOD. LOOKING FOR HIGHS MID 60S WED AND UPR 60S THU FOR MOST VALLEY LOCATIONS. LOWS WEDNESDAY NIGHT WILL RANGE WIDELY UNDER GOOD RADIATIONAL COOLING CONDITIONS...FROM NEAR 30F AT SLK/ESSEX COUNTY TO THE UPR 30S/LOWER 40S ELSEWHERE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 410 AM EDT TUESDAY...OVERALL VERY QUIET DAYS 4 THRU 7 ANTICIPATED WITH ABOVE NORMAL TEMPS AND BLW NORMAL CHCS FOR PRECIP. LARGE SCALE PATTERN WL FEATURE BUILDING MID/UPPER LVL RIDGE AND ASSOCIATED SFC HIGH PRES ACRS THE NE CONUS. SEVERAL WEAK FEATURES WL HAVE TO BE WATCHED FOR POTENTIAL MINOR IMPACTS ACRS OUR CWA THRU THE TIME PERIOD. FIRST WL BE WEAK AREA OF LOW PRES ALONG THE EASTERN SEABOARD ON FRI-SAT...WHICH COULD SPREAD CLOUDS AND COOLER EASTERLY FLW INTO OUR REGION...ALONG WITH A CHC FOR SOME LIGHT PRECIP. BOTH ECMWF/GFS SHOW BEST LIFT/MOISTURE SOUTH OF OUR CWA THOUGH. NEXT FEATURE IS A WEAK BACKDOOR SFC COLD FRONT ON SAT AFTN/EVENING...WHICH WL PRODUCE COOLER TEMPS AND MAYBE A SPRINKLE ACRS THE NEK OF VERMONT. PROGGED 85H TEMPS START BTWN 10-12C FOR FRIDAY...BUT FALL BTWN 6-8C BY 06Z SUNDAY ACRS EASTERN VT. WL MENTION SLIGHTLY COOLER TEMPS...BUT STILL WELL ABOVE NORMAL. OTHERWISE...RIDGE ALOFT REBUILDS FOR SUNDAY/MONDAY...BEFORE NEXT WEEK SFC ARRIVES BY EARLY NEXT WEEK. BOTH ECMWF/GFS SHOW A WEAK RIBBON OF ENHANCED MOISTURE/LIFT...SO WL MENTION SCHC/CHC POPS...MAINLY ACRS NNY. OTHERWISE...TEMPS WL RANGE MAINLY IN THE 60S TO NEAR 70F WITH LOWS IN THE 40S TO NEAR 50F THRU THE PERIOD. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... THROUGH 06Z WEDNESDAY...AVIATION CHALLENGE WL BE CIGS THRU THIS MORNING...ALONG WITH WINDS. SFC ANALYSIS PLACES SECONDARY COLD FRNT ACRS THE CPV ATTM...WITH BREEZY WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS. THIS UPSLOPE FLW AND LEFTOVER MOISTURE...COMBINED WITH LLVL CAA WL HELP IN THE DEVELOPMENT OF MVFR WITH A PERIOD OF IFR CIGS AT SLK THIS MORNING...BASED ON RAP 13 RH PROFILES. LATEST 3.9 SATL TRENDS SHOW CLOUDS REDEVELOPING ACRS THE OTTAWA VALLEY AND SLV ATTM...WHICH WL MOVE INTO THE DACKS AND THE REST OF OUR CWA THRU EARLY THIS MORNING. HOWEVER...AS SFC HIGH PRES LOCATED OVER THE OHIO VALLEY BUILDS INTO THE REGION...DRIER AIR ADVECTS ACRS OUR TAF SITES RESULTING IN VFR CONDITIONS BY 15Z. STILL THINKING SOME UPSLOPE CLOUDS WL LINGER AT SLK/MPV THRU THIS MORNING...WITH WEST WINDS AT 5 TO 10 KNTS. EXPECT CLR SKIES WITH LIGHT WINDS BY EVENING WITH AREAS OF FOG DEVELOPING BTWN 04-06Z...ESPECIALLY AT SLK/MPV. OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...A BUILDING RIDGE OF HIGH PRES BOTH ALOFT AND AT THE SFC WL RESULT IN VFR CONDITIONS THRU SATURDAY...WITH EXCEPTION OF IFR/LIFR IN MORNING FOG/BR...ESPECIALLY AT MPV/SLK. && .EQUIPMENT... AS OF 1054 PM EDT MONDAY...SURFACE OBSERVATIONS FROM MORRISVILLE STATE AIRPORT (KMVL) HAVE NOT REPORTED SINCE LATE THIS AFTERNOON. THIS OUTAGE IS DUE TO TELEPHONE LINE ISSUES WHICH ARE PREVENTING THE OBSERVATIONS FROM BEING TRANSMITTED TO THE OUTSIDE WORLD. THE TELEPHONE COMPANY HAS BEEN NOTIFIED OF THIS. NO ESTIMATE IS AVAILABLE AT THIS TIME AS TO WHEN SERVICE WILL BE RESTORED. AS OF 1054 PM EDT MONDAY...THE NOAA WEATHER RADIO TRANSMITTER ON TOP OF MOUNT ASCUTNEY IN SOUTHEAST VERMONT IS OFF THE AIR AT THIS TIME. NO ESTIMATE IS AVAILABLE AT THIS TIME AS TO WHEN SERVICE WILL BE RESTORED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS SHORT TERM...BANACOS LONG TERM...TABER AVIATION...TABER EQUIPMENT...WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
412 AM EDT TUE OCT 8 2013 .SYNOPSIS... FOLLOWING THE COLD FRONTAL PASSAGE YESTERDAY EVENING...COOLER AND DRIER AIR IS FILTERING INTO THE NORTH COUNTRY THIS MORNING ON NORTHWESTERLY WINDS. LINGERING STRATUS CLOUDS THIS MORNING WILL GIVE WAY TO FULL SUNSHINE AS HIGH PRESSURE BUILDS EASTWARD FROM THE GREAT LAKES REGION. STATIONARY HIGH PRESSURE THROUGH A DEEP-LAYER OF THE ATMOSPHERE WILL PROVIDE AN EXTENDED PERIOD OF TRANQUIL WEATHER ACROSS THE NORTH COUNTRY THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL BE NEAR AVERAGE TODAY...AND THEN MODERATE BACK ABOVE AVERAGE THROUGH THE NEXT SEVEN DAYS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 309 AM EDT TUESDAY...STRATUS DECK REMAINS EARLY THIS MORNING IN FRONTAL INVERSION LAYER BETWEEN 3-5 KFT...WITH SOME LOWER CLOUDS HGTS VCNTY MTNS WITH OROGRAPHIC INFLUENCES. COMBINATION OF DRY ADVECTION AND INCREASING SUBSIDENCE AS SFC HIGH BUILDS EAST FROM THE GREAT LAKES SHOULD DISSIPATE THESE REMAINING CLOUDS BY MID-MORNING...WITH CLOUDS LINGERING LATEST VCNTY OF THE ADIRONDACKS AND N-CENTRAL/NERN VT. A FEW FAIR WX CU WILL DOT THE HIGHER TERRAIN DURING THE AFTN HOURS...BUT SKIES WILL OTHERWISE BE SUNNY. SHOULD BE ABOUT 20 DEGREES COOLER THAN YESTERDAY AT BTV...60F OR SO AFTER HITTING 80 YESTERDAY. WINDS WILL CONTINUE FROM THE NW AROUND 10 MPH...DIMINISHING TOWARD SUNSET AS BOUNDARY LAYER STABILIZES. CLEAR AND CALM TONIGHT WITH CENTER OF SFC ANTICYCLONE BUILDING OVER THE NORTH COUNTRY. GOOD RADIATIVE COOLING AND RECENT RAINFALL WILL LEAD TO FOG IN THE FAVORED VALLEY LOCATIONS 06-14Z WEDNESDAY. MAY SEE A FEW PATCHES OF FROST IN THE CHAMPLAIN VALLEY WHERE GROWING SEASON REMAINS ACTIVE. MARGINAL FROST ADVISORY CONDITIONS IN SPOTS BASED ON LOW TEMPS 35-38F...AND AROUND 40F ON GRAND ISLE WITH MODERATING INFLUENCE OF WARM LAKE TEMPERATURES. INCLUDED PATCHY FROST FOR THOSE ISOLATED SPOTS AWAY FROM LAKE CHAMPLAIN WITH MIN TEMPS FORECAST AT 36F OR LESS. TEMPERATURES WILL BE COLDEST IN THE ADIRONDACKS AND NORTHEAST KINGDOM WITH LOWS THERE IN THE UPR 20S TO LOWER 30S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 309 AM EDT TUESDAY...SYNOPTICALLY QUIESCENT CONDITIONS PREVAIL WITH DEEP-LAYER RIDGE IN PLACE. USED BLEND OF MOS CONSENSUS AND BIAS-CORRECTED MOS CONSENSUS ON TEMPERATURES...WHICH SHOULD MODERATE THRU THE PERIOD. LOOKING FOR HIGHS MID 60S WED AND UPR 60S THU FOR MOST VALLEY LOCATIONS. LOWS WEDNESDAY NIGHT WILL RANGE WIDELY UNDER GOOD RADIATIONAL COOLING CONDITIONS...FROM NEAR 30F AT SLK/ESSEX COUNTY TO THE UPR 30S/LOWER 40S ELSEWHERE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 355 PM EDT MONDAY...STRONG UPPER RIDGE BECOMES ESTABLISHED ONCE AGAIN OVER THE NORTHEAST UNITED STATES THROUGH MUCH OF THE EXTENDED PERIOD. FORECAST SOUNDINGS POINT OUT A COUPLE OF KEY ELEMENTS DURING THIS TIME PERIOD. FIRST THE WARMING ALOFT WITH BE RATHER PRONOUNCED...BUT MIXING WILL BE LIMITED AND NEVER TAP INTO THE WARMEST AIR ALOFT. THIS SHOULD RESULT IN HIGH TEMPERATURES REMAINING IN THE 60S THROUGH THE PERIOD...WHICH WILL BE SEVERAL DEGREES ABOVE NORMAL AND THIS WILL BE THE CASE WITH OVERNIGHT LOWS AS WELL. ALSO OF NOTE IS THE DEEP LAYER OF DRY AIR...SO PLENTY OF SUNSHINE SHOULD EXIST DURING THE DAY WITH NO REAL SHOT AT TRAPPING ANY LOW LEVEL MOISTURE AT NIGHT UNDER THE INVERSION. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... THROUGH 06Z WEDNESDAY...AVIATION CHALLENGE WL BE CIGS THRU THIS MORNING...ALONG WITH WINDS. SFC ANALYSIS PLACES SECONDARY COLD FRNT ACRS THE CPV ATTM...WITH BREEZY WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS. THIS UPSLOPE FLW AND LEFTOVER MOISTURE...COMBINED WITH LLVL CAA WL HELP IN THE DEVELOPMENT OF MVFR WITH A PERIOD OF IFR CIGS AT SLK THIS MORNING...BASED ON RAP 13 RH PROFILES. LATEST 3.9 SATL TRENDS SHOW CLOUDS REDEVELOPING ACRS THE OTTAWA VALLEY AND SLV ATTM...WHICH WL MOVE INTO THE DACKS AND THE REST OF OUR CWA THRU EARLY THIS MORNING. HOWEVER...AS SFC HIGH PRES LOCATED OVER THE OHIO VALLEY BUILDS INTO THE REGION...DRIER AIR ADVECTS ACRS OUR TAF SITES RESULTING IN VFR CONDITIONS BY 15Z. STILL THINKING SOME UPSLOPE CLOUDS WL LINGER AT SLK/MPV THRU THIS MORNING...WITH WEST WINDS AT 5 TO 10 KNTS. EXPECT CLR SKIES WITH LIGHT WINDS BY EVENING WITH AREAS OF FOG DEVELOPING BTWN 04-06Z...ESPECIALLY AT SLK/MPV. OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...A BUILDING RIDGE OF HIGH PRES BOTH ALOFT AND AT THE SFC WL RESULT IN VFR CONDITIONS THRU SATURDAY...WITH EXCEPTION OF IFR/LIFR IN MORNING FOG/BR...ESPECIALLY AT MPV/SLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS SHORT TERM...BANACOS LONG TERM... AVIATION...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
157 AM EDT TUE OCT 8 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO THE NORTH COUNTRY ON TUESDAY AND WILL REMAIN OVER THE REGION THE REMAINDER OF THIS WEEK WITH MAINLY CLEAR SKIES AND MORE SEASONAL TEMPERATURES EXPECTED. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 151 AM EDT TUESDAY...MOSTLY CLOUDY CONDITIONS PREVAIL ACROSS MOST OF THE NORTH COUNTRY EARLY THIS MORNING WITH RESIDUAL LOW- LEVEL MOISTURE IN THE WAKE OF THE FRONTAL PASSAGE. SKIES WILL REMAIN MOSTLY CLOUDY ACROSS CENTRAL/ERN VT AND ACROSS THE NRN ADIRONDACKS WITH GRADUAL CLEARING ELSEWHERE AS DRIER/COOLER AIR MASS ADVECTS IN WITH PREVAILING WNWLY LOW-LEVEL FLOW. CAN/T RULE OUT A BRIEF SPRINKLE/LIGHT SHOWER IN THE MTNS THRU DAYBREAK...AND THAT IS WHERE POPS REMAIN 15-20%. LOW TEMPERATURES WILL GENERALLY BE IN THE MID-UPR 40S. HAVE MADE SOME MINOR ADJUSTMENTS TO POPS/SKY GRIDS BASED ON RECENT TRENDS...BUT OVERALL FORECAST IS ON TRACK. && .SHORT TERM /8 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... AS OF 425 PM EDT MONDAY...HIGH PRESSURE BUILDS INTO THE REGION AT THE SFC FROM THE SW...BRINGING W-NW FLOW ACROSS THE NORTH COUNTRY. WITH MUCH DRIER AIR IN PLACE...MOSTLY CLEAR SKIES ANTICIPATED FOR THE DURATION OF THE SHORT TERM. COOLER AIR IN PLACE TO START TUESDAY WITH WARMING TREND FOR WEDNESDAY AND WEDNESDAY NIGHT. MAX TEMPS TUESDAY WILL NOTICEABLY COLDER IN THE M40S-L60S. AS THE SFC HIGH CRESTS OVER THE NORTH COUNTRY TUESDAY NIGHT...TEMPS WILL DROP INTO THE 30S...AND L-M20S IN THE HIGH TRRN. WITH THE CPV GROWING SEASON STILL IN PLAY...MAY NEED TO THINK ABOUT FROST ISSUES FOR EARLY WEDNESDAY MORNING. WEDNESDAY AND WEDNESDAY NIGHT WILL MODERATE AS THE HIGH SHIFTS TO OUR EAST...ALLOWING FOR LGT SRLY FLOW. MAX TEMPS IN THE 60S IN THE VALLEYS AND 50S IN THE HIGH TRRN. MIN TEMPS IN THE 40S IN THE VALLEY AND 30S IN THE HIGH TRRN. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 355 PM EDT MONDAY...STRONG UPPER RIDGE BECOMES ESTABLISHED ONCE AGAIN OVER THE NORTHEAST UNITED STATES THROUGH MUCH OF THE EXTENDED PERIOD. FORECAST SOUNDINGS POINT OUT A COUPLE OF KEY ELEMENTS DURING THIS TIME PERIOD. FIRST THE WARMING ALOFT WITH BE RATHER PRONOUNCED...BUT MIXING WILL BE LIMITED AND NEVER TAP INTO THE WARMEST AIR ALOFT. THIS SHOULD RESULT IN HIGH TEMPERATURES REMAINING IN THE 60S THROUGH THE PERIOD...WHICH WILL BE SEVERAL DEGREES ABOVE NORMAL AND THIS WILL BE THE CASE WITH OVERNIGHT LOWS AS WELL. ALSO OF NOTE IS THE DEEP LAYER OF DRY AIR...SO PLENTY OF SUNSHINE SHOULD EXIST DURING THE DAY WITH NO REAL SHOT AT TRAPPING ANY LOW LEVEL MOISTURE AT NIGHT UNDER THE INVERSION. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... THROUGH 06Z WEDNESDAY...AVIATION CHALLENGE WL BE CIGS THRU THIS MORNING...ALONG WITH WINDS. SFC ANALYSIS PLACES SECONDARY COLD FRNT ACRS THE CPV ATTM...WITH BREEZY WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS. THIS UPSLOPE FLW AND LEFTOVER MOISTURE...COMBINED WITH LLVL CAA WL HELP IN THE DEVELOPMENT OF MVFR WITH A PERIOD OF IFR CIGS AT SLK THIS MORNING...BASED ON RAP 13 RH PROFILES. LATEST 3.9 SATL TRENDS SHOW CLOUDS REDEVELOPING ACRS THE OTTAWA VALLEY AND SLV ATTM...WHICH WL MOVE INTO THE DACKS AND THE REST OF OUR CWA THRU EARLY THIS MORNING. HOWEVER...AS SFC HIGH PRES LOCATED OVER THE OHIO VALLEY BUILDS INTO THE REGION...DRIER AIR ADVECTS ACRS OUR TAF SITES RESULTING IN VFR CONDITIONS BY 15Z. STILL THINKING SOME UPSLOPE CLOUDS WL LINGER AT SLK/MPV THRU THIS MORNING...WITH WEST WINDS AT 5 TO 10 KNTS. EXPECT CLR SKIES WITH LIGHT WINDS BY EVENING WITH AREAS OF FOG DEVELOPING BTWN 04-06Z...ESPECIALLY AT SLK/MPV. OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...A BUILDING RIDGE OF HIGH PRES BOTH ALOFT AND AT THE SFC WL RESULT IN VFR CONDITIONS THRU SATURDAY...WITH EXCEPTION OF IFR/LIFR IN MORNING FOG/BR...ESPECIALLY AT MPV/SLK. && .MARINE... AS OF 1100 PM EDT MONDAY...SOUTHWEST WINDS OF 15 TO 25 KTS WILL CONTINUE THROUGH MOST OF TONIGHT OVER THE OPEN WATERS OF LAKE CHAMPLAIN..BEFORE GRADUALLY DIMINISHING TOWARDS MORNING. WAVES UP TO 2 TO 3 FEET ARE EXPECTED...DECREASING TO 1 TO 2 FEET TOWARDS MORNING. && .EQUIPMENT... AS OF 1054 PM EDT MONDAY...SURFACE OBSERVATIONS FROM MORRISVILLE STATE AIRPORT (KMVL) AND RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) HAVE NOT REPORTED SINCE LATE THIS AFTERNOON. BOTH OF THESE OUTAGES ARE DUE TO TELEPHONE LINE ISSUES WHICH ARE PREVENTING THE OBSERVATIONS FROM THESE SITES TO BE TRANSMITTED TO THE OUTSIDE WORLD. THE TELEPHONE COMPANY HAS BEEN NOTIFIED OF THIS. NO ESTIMATE IS AVAILABLE AT THIS TIME AS TO WHEN SERVICE WILL BE RESTORED. AS OF 1054 PM EDT MONDAY...THE NOAA WEATHER RADIO TRANSMITTER ON TOP OF MOUNT ASCUTNEY IN SOUTHEAST VERMONT IS OFF THE AIR AT THIS TIME. NO ESTIMATE IS AVAILABLE AT THIS TIME AS TO WHEN SERVICE WILL BE RESTORED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...WGH NEAR TERM...BANACOS/WGH SHORT TERM...KGM LONG TERM...EVENSON AVIATION...TABER MARINE...WFO BTV EQUIPMENT...WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
140 AM EDT TUE OCT 8 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO THE NORTH COUNTRY ON TUESDAY AND WILL REMAIN OVER THE REGION THE REMAINDER OF THIS WEEK WITH MAINLY CLEAR SKIES AND MORE SEASONAL TEMPERATURES EXPECTED. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1054 PM EDT MONDAY...COMPOSITE RADAR LOOP SHOWING SOME SCATTERED RAIN SHOWERS ACROSS THE SOUTHWEST SAINT LAWRENCE VALLEY APPROACHING THE ADIRONDACKS AT THIS TIME. THIS IS ASSOCIATED WITH THE SECONDARY COLD FRONT MOVING INTO THE REGION AT THIS TIME. WILL KEEP IN A SLIGHT CHANCE FOR SOME RAIN SHOWERS FOR A PORTION OF THE OVERNIGHT PERIOD WITH THIS FRONTAL PASSAGE. && .SHORT TERM /8 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... AS OF 425 PM EDT MONDAY...HIGH PRESSURE BUILDS INTO THE REGION AT THE SFC FROM THE SW...BRINGING W-NW FLOW ACROSS THE NORTH COUNTRY. WITH MUCH DRIER AIR IN PLACE...MOSTLY CLEAR SKIES ANTICIPATED FOR THE DURATION OF THE SHORT TERM. COOLER AIR IN PLACE TO START TUESDAY WITH WARMING TREND FOR WEDNESDAY AND WEDNESDAY NIGHT. MAX TEMPS TUESDAY WILL NOTICEABLY COLDER IN THE M40S-L60S. AS THE SFC HIGH CRESTS OVER THE NORTH COUNTRY TUESDAY NIGHT...TEMPS WILL DROP INTO THE 30S...AND L-M20S IN THE HIGH TRRN. WITH THE CPV GROWING SEASON STILL IN PLAY...MAY NEED TO THINK ABOUT FROST ISSUES FOR EARLY WEDNESDAY MORNING. WEDNESDAY AND WEDNESDAY NIGHT WILL MODERATE AS THE HIGH SHIFTS TO OUR EAST...ALLOWING FOR LGT SRLY FLOW. MAX TEMPS IN THE 60S IN THE VALLEYS AND 50S IN THE HIGH TRRN. MIN TEMPS IN THE 40S IN THE VALLEY AND 30S IN THE HIGH TRRN. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 355 PM EDT MONDAY...STRONG UPPER RIDGE BECOMES ESTABLISHED ONCE AGAIN OVER THE NORTHEAST UNITED STATES THROUGH MUCH OF THE EXTENDED PERIOD. FORECAST SOUNDINGS POINT OUT A COUPLE OF KEY ELEMENTS DURING THIS TIME PERIOD. FIRST THE WARMING ALOFT WITH BE RATHER PRONOUNCED...BUT MIXING WILL BE LIMITED AND NEVER TAP INTO THE WARMEST AIR ALOFT. THIS SHOULD RESULT IN HIGH TEMPERATURES REMAINING IN THE 60S THROUGH THE PERIOD...WHICH WILL BE SEVERAL DEGREES ABOVE NORMAL AND THIS WILL BE THE CASE WITH OVERNIGHT LOWS AS WELL. ALSO OF NOTE IS THE DEEP LAYER OF DRY AIR...SO PLENTY OF SUNSHINE SHOULD EXIST DURING THE DAY WITH NO REAL SHOT AT TRAPPING ANY LOW LEVEL MOISTURE AT NIGHT UNDER THE INVERSION. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... THROUGH 06Z WEDNESDAY...AVIATION CHALLENGE WL BE CIGS THRU THIS MORNING...ALONG WITH WINDS. SFC ANALYSIS PLACES SECONDARY COLD FRNT ACRS THE CPV ATTM...WITH BREEZY WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS. THIS UPSLOPE FLW AND LEFTOVER MOISTURE...COMBINED WITH LLVL CAA WL HELP IN THE DEVELOPMENT OF MVFR WITH A PERIOD OF IFR CIGS AT SLK THIS MORNING...BASED ON RAP 13 RH PROFILES. LATEST 3.9 SATL TRENDS SHOW CLOUDS REDEVELOPING ACRS THE OTTAWA VALLEY AND SLV ATTM...WHICH WL MOVE INTO THE DACKS AND THE REST OF OUR CWA THRU EARLY THIS MORNING. HOWEVER...AS SFC HIGH PRES LOCATED OVER THE OHIO VALLEY BUILDS INTO THE REGION...DRIER AIR ADVECTS ACRS OUR TAF SITES RESULTING IN VFR CONDITIONS BY 15Z. STILL THINKING SOME UPSLOPE CLOUDS WL LINGER AT SLK/MPV THRU THIS MORNING...WITH WEST WINDS AT 5 TO 10 KNTS. EXPECT CLR SKIES WITH LIGHT WINDS BY EVENING WITH AREAS OF FOG DEVELOPING BTWN 04-06Z...ESPECIALLY AT SLK/MPV. OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...A BUILDING RIDGE OF HIGH PRES BOTH ALOFT AND AT THE SFC WL RESULT IN VFR CONDITIONS THRU SATURDAY...WITH EXCEPTION OF IFR/LIFR IN MORNING FOG/BR...ESPECIALLY AT MPV/SLK. && .MARINE... AS OF 1100 PM EDT MONDAY...SOUTHWEST WINDS OF 15 TO 25 KTS WILL CONTINUE THROUGH MOST OF TONIGHT OVER THE OPEN WATERS OF LAKE CHAMPLAIN..BEFORE GRADUALLY DIMINISHING TOWARDS MORNING. WAVES UP TO 2 TO 3 FEET ARE EXPECTED...DECREASING TO 1 TO 2 FEET TOWARDS MORNING. && .EQUIPMENT... AS OF 1054 PM EDT MONDAY...SURFACE OBSERVATIONS FROM MORRISVILLE STATE AIRPORT (KMVL) AND RUTLAND-SOUTHERN VERMONT REGIONAL AIRPORT (KRUT) HAVE NOT REPORTED SINCE LATE THIS AFTERNOON. BOTH OF THESE OUTAGES ARE DUE TO TELEPHONE LINE ISSUES WHICH ARE PREVENTING THE OBSERVATIONS FROM THESE SITES TO BE TRANSMITTED TO THE OUTSIDE WORLD. THE TELEPHONE COMPANY HAS BEEN NOTIFIED OF THIS. NO ESTIMATE IS AVAILABLE AT THIS TIME AS TO WHEN SERVICE WILL BE RESTORED. AS OF 1054 PM EDT MONDAY...THE NOAA WEATHER RADIO TRANSMITTER ON TOP OF MOUNT ASCUTNEY IN SOUTHEAST VERMONT IS OFF THE AIR AT THIS TIME. NO ESTIMATE IS AVAILABLE AT THIS TIME AS TO WHEN SERVICE WILL BE RESTORED. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...WGH NEAR TERM...WGH SHORT TERM...KGM LONG TERM...EVENSON AVIATION...TABER MARINE...WFO BTV EQUIPMENT...WGH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1015 PM EDT WED OCT 9 2013 .SYNOPSIS... A STRONG SURFACE HIGH PRESSURE WILL EXTEND INTO THE CAROLINAS FROM NEW ENGLAND THROUGH THURSDAY. A COMPLEX AREA OF LOW PRESSURE OFF THE SOUTHEAST COAST WILL MOVE SLOWLY NORTH UP THE MID-ATLANTIC COAST THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1010 PM WEDNESDAY THE MID LEVEL LOW THIS EVENING IS CURRENTLY CENTERED NEAR THE NC/VA BORDER ACROSS THE NORTHERN PIEDMONT/NORTHERN COASTAL PLAIN PORTIONS OF CENTRAL NC. THIS MID LEVEL LOW IS EXPECTED TO MOVE VERY LITTLE OVERNIGHT WITH A BLOCKING MID LEVEL RIDGE TO THE NORTH. MEANWHILE... SURFACE LOW PRESSURE IS LOCATED OFF THE NC COAST ALONG THE STALLED SURFACE FRONT JUST OFFSHORE... WITH A 1030 MB SURFACE HIGH ALONG THE NEW ENGLAND COAST EXTENDING SOUTH/SOUTHWESTWARD INTO FAR WESTERN NC. THIS SHOULD SUPPORT THE BEST POPS FROM ENERGY ROTATING AROUND THE MID LEVEL LOW ACROSS THE NORTHEAST/NORTHERN PORTION OF CENTRAL NC... WITH THE LEAST CHANCES ACROSS THE FAR SOUTHWEST PIEDMONT. ANY DEEP MOISTURE IS LOCATED TO THE NORTH AND EAST OF CENTRAL NC AND IS EXPECTED TO REMAIN SO OVERNIGHT... WITH BOTH THE NAM AND GFS BUFR SOUNDINGS SHOWING QUITE A BIT OF DRY AIR ABOVE 500-550 MB (WITH LACK OF ANY MUCAPE AS WELL). THUS... NOT EXPECTING ANY ISSUES WITH FLOODING... WITH GENERALLY ANY RAINFALL AMOUNTS (MOST ACROSS THE NORTHERN PIEDMONT AND NORTHERN COASTAL PLAIN) A QUARTER OF AN INCH OR LESS... WITH LIGHT RAIN AND/OR DRIZZLE. GIVEN A DECENT MSLP GRADIENT ACROSS THE AREA EXPECT WE WILL CONTINUE TO SEE SOME GUSTY WINDS OVERNIGHT... WITH WIND GUSTS OF UP TO 20 TO 25 MPH ACROSS THE EAST AND NORTH. EXPECT SKIES WILL REMAIN OVERCAST WITH A DEVELOPING/REINFORCING CAD AIRMASS. THIS SHOULD LEAD TO NEAR STEADY TEMPS ACROSS THE EAST TO TEMPS FALLING GENERALLY ANOTHER 5 TO 10 DEGREES ACROSS THE WEST. EXPECT LOW TEMPS WILL RANGE FROM THE LOW 50S WEST TO MID TO UPPER 50S EAST. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 300 PM WEDNESDAY MID-UPPER LEVEL CYCLONE WILL SLOWLY DRIFT NWD THIS PERIOD...BEING BLOCKED BY THE PERSISTENT HIGH OVER NEW ENGLAND. LOW-MID LEVEL NLY FLOW WILL MAINTAIN CLOUDY AND COOL CONDITIONS. A BAND OF RAIN ASSOCIATED WITH A MID LEVEL TROUGH SHOULD BE OCCURRING EARLY THU OVER SECTIONS OF THE NE PIEDMONT. AS THE DAY WEARS ON...CONVERGENCE ALONG THIS FEATURE PROJECTED TO WEAKEN...SUGGESTING THE LIGHT RAIN WILL BECOME SPOTTY LIGHT RAIN OR MAINLY DRIZZLE. CLOUDS EXPECTED TO BE THICKER IN THIS REGION AS WELL. ELSEWHERE...WHILE CONSIDERABLE CLOUDINESS WILL BE PREVALENT...THEY WILL NOT BE AS LOW/THICK AS WHAT IS EXPECTED OVER THE TRIANGLE-BUY AREAS. THUS...EXPECT A POCKET OF COOLER TEMPS OVER THE HEART OF CENTRAL NC (LOWER 60S) WITH AFTERNOON TEMPS IN THE MID-UPPER 60S (POSSIBLY LOWER 70S FAR SW) OVER OUR EASTERN AND WESTERN FRINGES. NLY WINDS WILL INITIALLY GUST AROUND 20-25 MPH ...MAINLY IN THE MORNING. THE PRESSURE GRADIENT EXPECTED TO GRADUALLY RELAX BY LATE IN THE DAY. CYCLONIC CIRCULATION OVER THE REGION THURSDAY NIGHT WILL MAINTAIN CONSIDERABLE CLOUDINESS. APPEARS THAT ANY PRECIP WILL BE SPOTTY AND VERY LIGHT...AND MAINLY OVER THE NORTHERN PIEDMONT-NORTHERN COASTAL PLAIN. MIN TEMPS FAIRLY UNIFORM IN THE MID 50S. RELAXING PRESSURE GRADIENT WILL RESULT IN SUSTAINED WINDS IN THE 4-7 MPH RANGE. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 240 PM WEDNESDAY... FOR FRIDAY THROUGH SATURDAY NIGHT: THE STAGNANT UNSETTLED PATTERN WILL LINGER INTO THE WEEKEND WITH ONLY FAINT SIGNS OF FINALLY BREAKING DOWN. FRIDAY WILL FEATURE THE UPPER LOW STILL SITTING OVER ERN VA/NE NC... WITH THE CORRESPONDING 850 MB LOW OVER OR JUST OFF THE NRN OUTER BANKS... AND THE SURFACE LOW JUST OFF THE VA COAST... WHILE THE SURFACE HIGH CENTERED OVER SE CANADA EXTENDS NARROWLY SOUTHWARD THROUGH WRN NC. THE STEADY FEED OF ATLANTIC MOISTURE BELOW 700 MB INTO CENTRAL NC VIA A CONFLUENT EASTERLY OR NORTHEASTERLY FLOW WILL PERSIST... WITH FORECAST SOUNDINGS SHOWING NEAR SATURATION THROUGH THIS LAYER INTO SATURDAY MORNING. GRADUAL MINOR IMPROVEMENT IS ANTICIPATED AS THE GFS/ECMWF SHOW THE 850 MB LOW SLOWLY FILLING AND DRIFTING NORTHWARD IN RESPONSE TO THE MID LEVEL RIDGING CENTERED OVER THE GULF ATTEMPTING TO BUILD NE TOWARD NC. THIS WILL SHIFT OUR 950-700 MB FLOW AROUND TO NORTHERLY... AND WHILE WE`LL SEE SOME REDUCTION IN THE DEPTH AND EXTEND OF MOISTURE IN THIS LAYER AS WE HEAD INTO SATURDAY... THE AIR MASS TO THE NORTH WILL STILL BE RATHER MOIST... AND AT LEAST SOME CLOUDS WILL PERSIST. APART FROM WEAK MID LEVEL DPVA AS ENERGY SPINS AROUND THE LOW... AND QUICKLY WEAKENING MOIST UPGLIDE AROUND 295K-300K THAT IS ALL BUT GONE BY FRIDAY NIGHT... THERE IS LITTLE TO NO APPARENT FORCING FOR ASCENT. WILL RETAIN GENERALLY CLOUDY SKIES AREAWIDE AND A SMALL CHANCE OF RAIN MAINLY ACROSS THE NORTH AND NE FRIDAY... SLOWLY RETREATING NORTHWARD AND TAPERING TO PATCHY DRIZZLE IN THE NORTHEAST ONLY FRIDAY NIGHT... BUT WITH CONTINUED MOSTLY CLOUDY SKIES. BY SATURDAY... WE`LL STILL HAVE A GOOD MOIST ONSHORE FETCH AROUND 850 MB DRIVING INTO THE MIDATLANTIC COAST... SO EXPECT SKIES TO BE MOSTLY CLOUDY FOR MUCH OF THE DAY OVER THE NORTHEAST CWA WITH SKIES BECOMING PARTLY CLOUDY ELSEWHERE AS THE LOW LEVELS START TO DRY OUT A BIT. WE MAY SEE SOME PATCHY DRIZZLE IN THE MORNING BUT OTHERWISE ANY REMAINING MOIST UPGLIDE IS GONE BY SATURDAY MORNING... SO EXPECT A GENERALLY DRY DAY WITH NO WORSE THAN ISOLATED SPRINKLES NEAR THE VA BORDER. HIGHS FRIDAY WILL BE TRICKY GIVEN THE STRONG DEPENDENCE ON THE DEGREE OF CLOUD COVER. WILL NUDGE TEMPS UP A DEGREE OR SO FRIDAY AS ABOVE-NORMAL THICKNESSES WITH ANY SUNSHINE AT ALL WILL LEAD TO QUICK WARMING... HOWEVER GIVEN THE PATTERN IN PLACE WILL STAY A FEW DEGREES BELOW STATISTICAL GUIDANCE... 67 NE TO 75 SW. LOWS 55-59 WITH CLOUDS BLANKETING THE AREA HELPING TO LIMIT RADIATIONAL COOLING. WITH A LITTLE MORE SUNSHINE AND AIR MASS MODERATION... EXPECT HIGHS SATURDAY OF 70-78... AGAIN COOLEST NEAR THE VA BORDER. THE MID LEVEL LOW DRIFTS EVER SO SLOWLY TO OUR NE SATURDAY NIGHT... NUDGED BY THE STRONG SHORTWAVE TROUGH THAT MOVES FROM THE FRONT RANGE FRIDAY MORNING INTO SOUTH CENTRAL CANADA AND THE GREAT LAKES THROUGH SATURDAY NIGHT. ANOTHER ROUND OF STRATUS APPEARS LIKELY SATURDAY NIGHT WITH CONTINUED LOW LEVEL MOISTURE AND NIGHTTIME STABILIZATION BELOW 800 MB... AND A LIGHTER AND BY-NOW DIFFLUENT LOW LEVEL FLOW LEAVING NOWHERE FOR THIS LOW LEVEL MOISTURE TO GO. LOWS 54-59 UNDER MOSTLY CLOUDY SKIES. FOR SUNDAY THROUGH WEDNESDAY: BOTH THE FILLING MID LEVEL VORTEX AND THE ASSOCIATED SURFACE LOW JUST ENE OF THE FORECAST AREA SHOULD CONTINUE A VERY SLOW ENE DRIFT AWAY FROM NC. WITH THE WEAKENING SURFACE RIDGE CENTERED WELL TO OUR NORTH STILL EXTENDING DOWN THROUGH WRN NC... WE`LL RETAIN THE LOW LEVEL FLOW FROM THE NNE AND MID LEVEL FLOW FROM THE NW... A GENERALLY STABLE PATTERN BUT ONE IN WHICH THERE IS LITTLE OPPORTUNITY FOR DISPERSION OF THE LOWER LEVEL MOISTURE EITHER HORIZONTALLY (DUE TO RESIDUAL HIGH MOISTURE FLUX AND MOUNTAIN BLOCKING) OR VERTICALLY (DUE TO THE STABILITY AND DIFFLUENT FLOW IN THE LOW LEVELS). THE VORTEX SLIPS A BIT FURTHER OUT TO SEA THROUGH TUESDAY AS NEW LONGWAVE TROUGHING DIGS OVER THE ROCKIES... ALLOWING THE GULF-CENTERED RIDGE ALOFT TO NUDGE A LITTLE FARTHER TOWARD NC. THE SURFACE RIDGE NOSING IN FROM THE NORTH WILL CONTINUE A SLOW MODIFICATION AS THE AXIS SHIFTS A LITTLE EASTWARD TO HAVE A GREATER INFLUENCE ON CENTRAL NC... SUPPORTING A TREND TO DRY WEATHER THROUGH THE FIRST HALF OF THE WEEK... BUT WITH PARTLY TO AT TIMES MOSTLY CLOUDY SKIES. MODELS SOLUTIONS DIVERGE REGARDING THE DEPTH AND EASTWARD PROGRESSION OF THE WRN TROUGH... WITH THE 00Z/09 ECMWF LESS AMPLIFIED (AND WITH ANOTHER WAVE DROPPING SOUTH THROUGH THE ROCKIES WEDNESDAY) WHILE THE 12Z/09 GFS HAS A MUCH DEEPER TROUGH PROGRESSING EASTWARD. IN EITHER CASE IT APPEARS WE`LL HAVE A SURFACE COLD FRONT APPROACHING FROM THE WEST ON WEDNESDAY... WITH GRADUALLY FALLING HEIGHTS ALOFT OVER NC. BUT BASED ON THE POTENTIAL TIMING ERRORS OF THE MODELS THIS FAR OUT... THE FRONT`S ARRIVAL COULD BE OFF BY A FULL DAY OR MORE FROM WHAT THE MODELS CURRENTLY SHOW... SO WILL BRING IN JUST A SMALL CHANCE OF SHOWERS AND STORMS INTO THE WRN CWA WEDNESDAY AFTERNOON. LOW LEVEL THICKNESSES ARE EXPECTED TO HOLD 5-10 M ABOVE NORMAL... SUPPORTING A TREND TOWARD TEMPS AROUND A CATEGORY WARMER THAN NORMAL... HIGHS IN THE MID-UPPER 70S AND LOWS IN THE MID-UPPER 50S. -GIH && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AS OF 815 PM WEDNESDAY... 24 HOUR TAF PERIOD: SIMILAR SYNOPTIC SETUP TO LAST NIGHT AS THE LOW CONTINUES TO CHURN ALONG THE COAST. THEREFORE IT REMAINS A VERY LOW CONFIDENCE FORECAST BUT MAYBE SLIGHTLY BETTER THAN LAST NIGHT. WILL DISCUSS THE FORECAST TRENDS AS THEY WILL BE MORE VALUABLE THAN THE DETAILS WHICH MAY CHANGE SEVERAL TIMES DURING THE TAF PERIOD. IN GENERAL CONDITIONS WILL GENERALLY BE WORSE FROM WEST TO EAST WITH A FOCUS FOR RAINFALL AND ADVERSE CONDITIONS IN THE NORTHEASTERN QUADRANT OF THE CWA. CURRENT CONDITIONS SHOW IFR FOR KRWI MVFR FOR KRDU AND KFAY AND VFR AT KINT AND KGSO. THIS GENERAL PATTERN OF SUB-VFR CONDITIONS SHOULD CONTINUE BUT WILL WORSEN WITH TIME AS THE TRIAD SITES ARE EXPECTED TO COME DOWN TO MVFR AND KRDU AND KFAY TO IFR WHILE KRWI IS EXPECTED TO REMAIN AT IFR THROUGH THE TAF PERIOD. THIS IS SUPPORTED BY DATA FROM THE SREF AND THE HRRR MODELS WHICH DID A FAIRLY GOOD JOB LAST NIGHT AS WELL. ONE DIFFERENCE FROM LAST NIGHT IS THAT THE HEAVIER BANDS OF PRECIPITATION SHOULD STAY WELL EAST OF THE AREA AND THE GENERAL MODE OF PRECIPITATION WILL BE LIGHT RAIN. WINDS WILL REMAIN NEAR 10 KNOTS GUSTING UP TO 20 AND THEY WILL CONTINUE THROUGH THE TAF PERIOD. WIND DIRECTION IS EXPECTED TO REMAIN LARGELY NORTHERLY. LONG TERM: THE LOW WILL CONTINUE TO SPIN OFF THE VIRGINIA COAST OVER THE NEXT FEW DAYS BUT MODELS SHOW SOME GRADUAL DISORGANIZATION. WHILE CLOUDY NORTHERLY FLOW WILL STILL DOMINATE AND BRING THE POTENTIAL FOR SUB-VFR CONDITIONS THROUGH THE WEEKEND...CONDITIONS WILL GRADUALLY IMPROVE AND THE THREAT FOR PRECIPITATION WILL DECREASE UNTIL LATE IN THE WEEKEND WHEN THE LOW IS EXPECTED TO RETROGRADE BACK SOUTHWARD WHICH MAY ONCE AGAIN INCREASE RAIN CHANCES DEPENDENT UPON PROXIMITY TO THE COAST. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CBL/BADGETT NEAR TERM...BSD SHORT TERM...WSS LONG TERM...HARTFIELD AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
815 PM EDT WED OCT 9 2013 .SYNOPSIS... A STRONG SURFACE HIGH PRESSURE WILL EXTEND INTO THE CAROLINAS FROM NEW ENGLAND THROUGH THURSDAY. A COMPLEX AREA OF LOW PRESSURE OFF THE SOUTHEAST COAST WILL MOVE SLOWLY NORTH UP THE MID-ATLANTIC COAST THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY REST OF THE AFTERNOON...HIGHEST THREAT FOR MEASURABLE RAIN THROUGH 6 PM WILL REMAIN OVER THE COASTAL PLAIN AND THE FAR NE PIEDMONT AS AN AREA OF LOW PRESSURE OVER THE REGION REMAINS NEARLY STATIONARY. OVER THE WESTERN AND SOUTHERN PIEDMONT...LOW CLOUDS NOT AS PREVALENT WHICH HAS ALLOWED PARTIAL SUN TO OCCUR. THIS IN TURN HAS WARMED TEMPS WELL INTO THE 60S...NEAR 70 AT A FEW SPOTS. AREAS OF RAIN AND LOW CLOUDS WILL HOLD TEMPS NEAR 60 IN THE NORTHERN COASTAL PLAIN AND FAR NE PIEDMONT. TONIGHT...STRONG HIGH PRESSURE ANCHORED COVER NEW ENGLAND WILL CAUSE THE LOW PRESSURE SYSTEM OVERHEAD TO REMAIN STATIONARY. A MID LEVEL TROUGH ROTATING AROUND THE LOW PROJECTED TO SWING ACROSS THE NORTHERN COASTAL PLAIN-NE PIEDMONT LATE TONIGHT-EARLY THU MORNING. CONVERGENCE ALONG THIS TROUGH WILL CAUSE PATCHES OF LIGHT RAIN TO DEVELOP. THUS...PLAN TO HAVE HIGH LIKELY-LOW END CATEGORICAL ACROSS THE FAR NORTHERN COUNTIES...EXTENDING AS FAR SOUTH AS THE TRIANGLE AREA BY EARLY THU. FORCING THROUGH THE COLUMN NOT CONTINUOUS...MAINLY CONCENTRATED BETWEEN 850-500MB...SO NOT EXPECTING HEAVY OR EXCESSIVE RAINFALL. MOST LOCATIONS ACROSS THE NORTHERN COASTAL PLAIN-NE PIEDMONT SHOULD MEASURE A QUARTER OF AN INCH OR LESS. ELSEWHERE...RAIN EXPECTED TO BE SPOTTY AT BEST WITH AMOUNTS TOTALING A TRACE TO A FEW HUNDREDTHS. A STEADY NLY WIND AND OVERCAST SKIES WILL RESULT IN A COMPACT DIURNAL TEMP RANGE. MIN TEMPS VARY FROM MID-UPPER 50S EAST TO LOWER 50S WEST. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 300 PM WEDNESDAY MID-UPPER LEVEL CYCLONE WILL SLOWLY DRIFT NWD THIS PERIOD...BEING BLOCKED BY THE PERSISTENT HIGH OVER NEW ENGLAND. LOW-MID LEVEL NLY FLOW WILL MAINTAIN CLOUDY AND COOL CONDITIONS. A BAND OF RAIN ASSOCIATED WITH A MID LEVEL TROUGH SHOULD BE OCCURRING EARLY THU OVER SECTIONS OF THE NE PIEDMONT. AS THE DAY WEARS ON...CONVERGENCE ALONG THIS FEATURE PROJECTED TO WEAKEN...SUGGESTING THE LIGHT RAIN WILL BECOME SPOTTY LIGHT RAIN OR MAINLY DRIZZLE. CLOUDS EXPECTED TO BE THICKER IN THIS REGION AS WELL. ELSEWHERE...WHILE CONSIDERABLE CLOUDINESS WILL BE PREVALENT...THEY WILL NOT BE AS LOW/THICK AS WHAT IS EXPECTED OVER THE TRIANGLE-BUY AREAS. THUS...EXPECT A POCKET OF COOLER TEMPS OVER THE HEART OF CENTRAL NC (LOWER 60S) WITH AFTERNOON TEMPS IN THE MID-UPPER 60S (POSSIBLY LOWER 70S FAR SW) OVER OUR EASTERN AND WESTERN FRINGES. NLY WINDS WILL INITIALLY GUST AROUND 20-25 MPH ...MAINLY IN THE MORNING. THE PRESSURE GRADIENT EXPECTED TO GRADUALLY RELAX BY LATE IN THE DAY. CYCLONIC CIRCULATION OVER THE REGION THURSDAY NIGHT WILL MAINTAIN CONSIDERABLE CLOUDINESS. APPEARS THAT ANY PRECIP WILL BE SPOTTY AND VERY LIGHT...AND MAINLY OVER THE NORTHERN PIEDMONT-NORTHERN COASTAL PLAIN. MIN TEMPS FAIRLY UNIFORM IN THE MID 50S. RELAXING PRESSURE GRADIENT WILL RESULT IN SUSTAINED WINDS IN THE 4-7 MPH RANGE. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 240 PM WEDNESDAY... FOR FRIDAY THROUGH SATURDAY NIGHT: THE STAGNANT UNSETTLED PATTERN WILL LINGER INTO THE WEEKEND WITH ONLY FAINT SIGNS OF FINALLY BREAKING DOWN. FRIDAY WILL FEATURE THE UPPER LOW STILL SITTING OVER ERN VA/NE NC... WITH THE CORRESPONDING 850 MB LOW OVER OR JUST OFF THE NRN OUTER BANKS... AND THE SURFACE LOW JUST OFF THE VA COAST... WHILE THE SURFACE HIGH CENTERED OVER SE CANADA EXTENDS NARROWLY SOUTHWARD THROUGH WRN NC. THE STEADY FEED OF ATLANTIC MOISTURE BELOW 700 MB INTO CENTRAL NC VIA A CONFLUENT EASTERLY OR NORTHEASTERLY FLOW WILL PERSIST... WITH FORECAST SOUNDINGS SHOWING NEAR SATURATION THROUGH THIS LAYER INTO SATURDAY MORNING. GRADUAL MINOR IMPROVEMENT IS ANTICIPATED AS THE GFS/ECMWF SHOW THE 850 MB LOW SLOWLY FILLING AND DRIFTING NORTHWARD IN RESPONSE TO THE MID LEVEL RIDGING CENTERED OVER THE GULF ATTEMPTING TO BUILD NE TOWARD NC. THIS WILL SHIFT OUR 950-700 MB FLOW AROUND TO NORTHERLY... AND WHILE WE`LL SEE SOME REDUCTION IN THE DEPTH AND EXTEND OF MOISTURE IN THIS LAYER AS WE HEAD INTO SATURDAY... THE AIR MASS TO THE NORTH WILL STILL BE RATHER MOIST... AND AT LEAST SOME CLOUDS WILL PERSIST. APART FROM WEAK MID LEVEL DPVA AS ENERGY SPINS AROUND THE LOW... AND QUICKLY WEAKENING MOIST UPGLIDE AROUND 295K-300K THAT IS ALL BUT GONE BY FRIDAY NIGHT... THERE IS LITTLE TO NO APPARENT FORCING FOR ASCENT. WILL RETAIN GENERALLY CLOUDY SKIES AREAWIDE AND A SMALL CHANCE OF RAIN MAINLY ACROSS THE NORTH AND NE FRIDAY... SLOWLY RETREATING NORTHWARD AND TAPERING TO PATCHY DRIZZLE IN THE NORTHEAST ONLY FRIDAY NIGHT... BUT WITH CONTINUED MOSTLY CLOUDY SKIES. BY SATURDAY... WE`LL STILL HAVE A GOOD MOIST ONSHORE FETCH AROUND 850 MB DRIVING INTO THE MIDATLANTIC COAST... SO EXPECT SKIES TO BE MOSTLY CLOUDY FOR MUCH OF THE DAY OVER THE NORTHEAST CWA WITH SKIES BECOMING PARTLY CLOUDY ELSEWHERE AS THE LOW LEVELS START TO DRY OUT A BIT. WE MAY SEE SOME PATCHY DRIZZLE IN THE MORNING BUT OTHERWISE ANY REMAINING MOIST UPGLIDE IS GONE BY SATURDAY MORNING... SO EXPECT A GENERALLY DRY DAY WITH NO WORSE THAN ISOLATED SPRINKLES NEAR THE VA BORDER. HIGHS FRIDAY WILL BE TRICKY GIVEN THE STRONG DEPENDENCE ON THE DEGREE OF CLOUD COVER. WILL NUDGE TEMPS UP A DEGREE OR SO FRIDAY AS ABOVE-NORMAL THICKNESSES WITH ANY SUNSHINE AT ALL WILL LEAD TO QUICK WARMING... HOWEVER GIVEN THE PATTERN IN PLACE WILL STAY A FEW DEGREES BELOW STATISTICAL GUIDANCE... 67 NE TO 75 SW. LOWS 55-59 WITH CLOUDS BLANKETING THE AREA HELPING TO LIMIT RADIATIONAL COOLING. WITH A LITTLE MORE SUNSHINE AND AIR MASS MODERATION... EXPECT HIGHS SATURDAY OF 70-78... AGAIN COOLEST NEAR THE VA BORDER. THE MID LEVEL LOW DRIFTS EVER SO SLOWLY TO OUR NE SATURDAY NIGHT... NUDGED BY THE STRONG SHORTWAVE TROUGH THAT MOVES FROM THE FRONT RANGE FRIDAY MORNING INTO SOUTH CENTRAL CANADA AND THE GREAT LAKES THROUGH SATURDAY NIGHT. ANOTHER ROUND OF STRATUS APPEARS LIKELY SATURDAY NIGHT WITH CONTINUED LOW LEVEL MOISTURE AND NIGHTTIME STABILIZATION BELOW 800 MB... AND A LIGHTER AND BY-NOW DIFFLUENT LOW LEVEL FLOW LEAVING NOWHERE FOR THIS LOW LEVEL MOISTURE TO GO. LOWS 54-59 UNDER MOSTLY CLOUDY SKIES. FOR SUNDAY THROUGH WEDNESDAY: BOTH THE FILLING MID LEVEL VORTEX AND THE ASSOCIATED SURFACE LOW JUST ENE OF THE FORECAST AREA SHOULD CONTINUE A VERY SLOW ENE DRIFT AWAY FROM NC. WITH THE WEAKENING SURFACE RIDGE CENTERED WELL TO OUR NORTH STILL EXTENDING DOWN THROUGH WRN NC... WE`LL RETAIN THE LOW LEVEL FLOW FROM THE NNE AND MID LEVEL FLOW FROM THE NW... A GENERALLY STABLE PATTERN BUT ONE IN WHICH THERE IS LITTLE OPPORTUNITY FOR DISPERSION OF THE LOWER LEVEL MOISTURE EITHER HORIZONTALLY (DUE TO RESIDUAL HIGH MOISTURE FLUX AND MOUNTAIN BLOCKING) OR VERTICALLY (DUE TO THE STABILITY AND DIFFLUENT FLOW IN THE LOW LEVELS). THE VORTEX SLIPS A BIT FURTHER OUT TO SEA THROUGH TUESDAY AS NEW LONGWAVE TROUGHING DIGS OVER THE ROCKIES... ALLOWING THE GULF-CENTERED RIDGE ALOFT TO NUDGE A LITTLE FARTHER TOWARD NC. THE SURFACE RIDGE NOSING IN FROM THE NORTH WILL CONTINUE A SLOW MODIFICATION AS THE AXIS SHIFTS A LITTLE EASTWARD TO HAVE A GREATER INFLUENCE ON CENTRAL NC... SUPPORTING A TREND TO DRY WEATHER THROUGH THE FIRST HALF OF THE WEEK... BUT WITH PARTLY TO AT TIMES MOSTLY CLOUDY SKIES. MODELS SOLUTIONS DIVERGE REGARDING THE DEPTH AND EASTWARD PROGRESSION OF THE WRN TROUGH... WITH THE 00Z/09 ECMWF LESS AMPLIFIED (AND WITH ANOTHER WAVE DROPPING SOUTH THROUGH THE ROCKIES WEDNESDAY) WHILE THE 12Z/09 GFS HAS A MUCH DEEPER TROUGH PROGRESSING EASTWARD. IN EITHER CASE IT APPEARS WE`LL HAVE A SURFACE COLD FRONT APPROACHING FROM THE WEST ON WEDNESDAY... WITH GRADUALLY FALLING HEIGHTS ALOFT OVER NC. BUT BASED ON THE POTENTIAL TIMING ERRORS OF THE MODELS THIS FAR OUT... THE FRONT`S ARRIVAL COULD BE OFF BY A FULL DAY OR MORE FROM WHAT THE MODELS CURRENTLY SHOW... SO WILL BRING IN JUST A SMALL CHANCE OF SHOWERS AND STORMS INTO THE WRN CWA WEDNESDAY AFTERNOON. LOW LEVEL THICKNESSES ARE EXPECTED TO HOLD 5-10 M ABOVE NORMAL... SUPPORTING A TREND TOWARD TEMPS AROUND A CATEGORY WARMER THAN NORMAL... HIGHS IN THE MID-UPPER 70S AND LOWS IN THE MID-UPPER 50S. -GIH && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AS OF 815 PM WEDNESDAY... 24 HOUR TAF PERIOD: SIMILAR SYNOPTIC SETUP TO LAST NIGHT AS THE LOW CONTINUES TO CHURN ALONG THE COAST. THEREFORE IT REMAINS A VERY LOW CONFIDENCE FORECAST BUT MAYBE SLIGHTLY BETTER THAN LAST NIGHT. WILL DISCUSS THE FORECAST TRENDS AS THEY WILL BE MORE VALUABLE THAN THE DETAILS WHICH MAY CHANGE SEVERAL TIMES DURING THE TAF PERIOD. IN GENERAL CONDITIONS WILL GENERALLY BE WORSE FROM WEST TO EAST WITH A FOCUS FOR RAINFALL AND ADVERSE CONDITIONS IN THE NORTHEASTERN QUADRANT OF THE CWA. CURRENT CONDITIONS SHOW IFR FOR KRWI MVFR FOR KRDU AND KFAY AND VFR AT KINT AND KGSO. THIS GENERAL PATTERN OF SUB-VFR CONDITIONS SHOULD CONTINUE BUT WILL WORSEN WITH TIME AS THE TRIAD SITES ARE EXPECTED TO COME DOWN TO MVFR AND KRDU AND KFAY TO IFR WHILE KRWI IS EXPECTED TO REMAIN AT IFR THROUGH THE TAF PERIOD. THIS IS SUPPORTED BY DATA FROM THE SREF AND THE HRRR MODELS WHICH DID A FAIRLY GOOD JOB LAST NIGHT AS WELL. ONE DIFFERENCE FROM LAST NIGHT IS THAT THE HEAVIER BANDS OF PRECIPITATION SHOULD STAY WELL EAST OF THE AREA AND THE GENERAL MODE OF PRECIPITATION WILL BE LIGHT RAIN. WINDS WILL REMAIN NEAR 10 KNOTS GUSTING UP TO 20 AND THEY WILL CONTINUE THROUGH THE TAF PERIOD. WIND DIRECTION IS EXPECTED TO REMAIN LARGELY NORTHERLY. LONG TERM: THE LOW WILL CONTINUE TO SPIN OFF THE VIRGINIA COAST OVER THE NEXT FEW DAYS BUT MODELS SHOW SOME GRADUAL DISORGANIZATION. WHILE CLOUDY NORTHERLY FLOW WILL STILL DOMINATE AND BRING THE POTENTIAL FOR SUB-VFR CONDITIONS THROUGH THE WEEKEND...CONDITIONS WILL GRADUALLY IMPROVE AND THE THREAT FOR PRECIPITATION WILL DECREASE UNTIL LATE IN THE WEEKEND WHEN THE LOW IS EXPECTED TO RETROGRADE BACK SOUTHWARD WHICH MAY ONCE AGAIN INCREASE RAIN CHANCES DEPENDENT UPON PROXIMITY TO THE COAST. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CBL/BADGETT NEAR TERM...WSS SHORT TERM...WSS LONG TERM...HARTFIELD AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
659 AM EDT TUE OCT 8 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE OHIO VALLEY TODAY...THEN PARK ITSELF OVER NEW ENGLAND THROUGH THE SECOND HALF OF THE WEEK. MEANWHILE...A WEAK AREA OF LOW PRESSURE OFF OF THE SOUTHEAST COAST WILL CRAWL SLOWLY NORTHWARD THROUGH THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MODIS 11-3.7UM IMAGERY SHOWING SOME PATCHY DENSE VALLEY FOG HAS FORMED EARLY THIS AM ACROSS WESTERN PA. HRRR AND LAMP GUIDANCE BOTH INDICATE ANY FOG WILL BURN OFF BTWN 13Z-14Z. LG SCALE SUBSIDENCE AND DRY AIR ASSOC WITH SFC HIGH SHOULD ENSURE ABUNDANT SUNSHINE FOR MOST OF CENTRAL PA TODAY. HOWEVER...THE NORTHERN EDGE OF CIRRUS SHIELD ASSOC WITH CUTOFF LOW OVR THE SOUTHEAST CONUS WILL MAKE SLOW PROGRESS NORTHWARD INTO THE AREA DURING THE DAY. GEFS MEAN 925 TEMPS ARE SUPPORTIVE OF HIGH TEMPS FROM THE L60S OVR THE ALLEGHENIES...TO THE U60S IN THE SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... HIGH PRES OVR THE AREA WILL ENSURE A DRY/TRANQUIL NIGHT. NORTHERN EDGE OF CIRRUS SHIELD WILL CONTINUE TO AFFECT MAINLY SOUTHERN PA. CLEAR SKIES AND A CALM WIND ACROSS THE NORTH SHOULD ALLOW TEMPS TO DIP INTO THE 30S WITH PATCHY VALLEY FOG/FROST. UPPER LOW AND ASSOC SFC WAVE WILL CONTINUE TO CRAWL NORTH ALONG THE E COAST ON WEDNESDAY...LIKELY SPREADING INCREASING CLOUDS INTO CENTRAL PA. HOWEVER...ALL MDL DATA INDICATE ANOMALOUSLY LOW PWATS REMAIN OVR THE AREA...ENSURING ANOTHER DRY DAY. BRIGHTEST SKIES SHOULD BE ACROSS THE N MTNS AND THE MOST CIRRUS ACROSS THE SOUTH...WHICH SHOULD RESULT IN UNIFORM HIGH TEMPS IN THE M60S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... CUT OFF UPPER LOW AND ASSOC MOIST EASTERLY LL JET LIFTING NORTH INTO THE AREA WILL LIKELY BRING A CLOUDY AND DAMP END TO THE WORK WEEK. GFS/GEFS MEAN BOTH INDICATING A SLIGHTLY MORE EASTERLY TRACK THAN OTHER MDL DATA...RESULTING IN LIGHTER QPF THAN ECMWF MEAN/CMC/NAM SOLUTIONS. FOR NOW...HAVE RAMPED UP POPS ACROSS THE ENTIRE AREA THURSDAY...BASED ON ALL MDL DATA INDICATING ARRIVAL OF ANOMALOUS EASTERLY FLOW AND PWATS...FOCUSED ESP ACROSS SE PA. BLENDED MDL QPF YIELDS 2 DAY RAINFALL TOTALS THU-FRI RANGING FROM ALMOST NOTHING ACROSS WARREN CO...TO ARND 1.5 INCHES ACROSS THE EASTERN THIRD OF THE STATE. HIGH FFG NUMBERS INDICATE THIS WOULD BE A BENEFICIAL RAIN...RATHER THAN A FLOOD THREAT. UPPER LOW INDICATED BY ALL MDL DATA TO SLOWLY PASS OFF THE MID ATLANTIC COAST NEXT WEEKEND...BRINGING A RETURN TO DRIER WX. LG SCALE RIDGE OVR THE E COAST SUGGESTS TEMPS WILL RETURN TO SLIGHTLY ABV NORMAL LEVELS BY THE WEEKEND WITH THE BENEFIT OF A BIT OF SUNSHINE. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... DESPITE CLEAR SKIES AND COOLER TEMPS...ENOUGH DRY AIR AND SOME WINDS WERE IN PLAY TO KEEP WIDESPREAD FROG FROM FORMING OVERNIGHT. ONLY BFD SAW SIGNIFICANT FOG DEVELOPMENT AND IS CURRENTLY SITTING WITH VLIFR VIS AND CIGS. CONDS WILL IMPROVE TO VFR EVERYWHERE BY 13/14Z...AS HIGH PRESSURE BUILDS INTO THE REGION...AND PERSIST THROUGH THE DAY. PATCHY FOG IS POSSIBLE AGAIN TONIGHT...FOLLOWED BY A RETURN TO VFR CONDS WEDNESDAY. AFTER THAT...FLYING CONDS MAY BEGIN TO DETERIORATE LATER IN THE WEEK AS EASTERLY FLOW DEVELOPS ACROSS THE REGION BETWEEN DEPARTING HIGH PRESSURE AND AN AREA OF LOW PRESSURE THAT MAY TRY TO DEVELOP ALONG THE MID-ATLANTIC COAST. OUTLOOK... WED...PATCHY AM FOG. OTHERWISE VFR. WED NIGHT-SATURDAY...EASTERLY FLOW DEVELOPS ACROSS THE AREA...ACCOMPANIED BY POTENTIAL FOR REDUCED CIGS AND VSBYS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...DANGELO/FITZGERALD AVIATION...GARTNER/EVANEGO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
604 AM EDT TUE OCT 8 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE OHIO VALLEY TODAY...THEN PARK ITSELF OVER NEW ENGLAND THROUGH THE SECOND HALF OF THE WEEK. MEANWHILE...A WEAK AREA OF LOW PRESSURE OFF OF THE SOUTHEAST COAST WILL CRAWL SLOWLY NORTHWARD THROUGH THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MODIS 11-3.7UM IMAGERY SHOWING SOME PATCHY DENSE VALLEY FOG HAS FORMED EARLY THIS AM ACROSS WESTERN PA. HRRR AND LAMP GUIDANCE BOTH INDICATE ANY FOG WILL BURN OFF BTWN 13Z-14Z. LG SCALE SUBSIDENCE AND DRY AIR ASSOC WITH SFC HIGH SHOULD ENSURE ABUNDANT SUNSHINE FOR MOST OF CENTRAL PA TODAY. HOWEVER...THE NORTHERN EDGE OF CIRRUS SHIELD ASSOC WITH CUTOFF LOW OVR THE SOUTHEAST CONUS WILL MAKE SLOW PROGRESS NORTHWARD INTO THE AREA DURING THE DAY. GEFS MEAN 925 TEMPS ARE SUPPORTIVE OF HIGH TEMPS FROM THE L60S OVR THE ALLEGHENIES...TO THE U60S IN THE SUSQ VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... HIGH PRES OVR THE AREA WILL ENSURE A DRY/TRANQUIL NIGHT. NORTHERN EDGE OF CIRRUS SHIELD WILL CONTINUE TO AFFECT MAINLY SOUTHERN PA. CLEAR SKIES AND A CALM WIND ACROSS THE NORTH SHOULD ALLOW TEMPS TO DIP INTO THE 30S WITH PATCHY VALLEY FOG/FROST. UPPER LOW AND ASSOC SFC WAVE WILL CONTINUE TO CRAWL NORTH ALONG THE E COAST ON WEDNESDAY...LIKELY SPREADING INCREASING CLOUDS INTO CENTRAL PA. HOWEVER...ALL MDL DATA INDICATE ANOMALOUSLY LOW PWATS REMAIN OVR THE AREA...ENSURING ANOTHER DRY DAY. BRIGHTEST SKIES SHOULD BE ACROSS THE N MTNS AND THE MOST CIRRUS ACROSS THE SOUTH...WHICH SHOULD RESULT IN UNIFORM HIGH TEMPS IN THE M60S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... CUT OFF UPPER LOW AND ASSOC MOIST EASTERLY LL JET LIFTING NORTH INTO THE AREA WILL LIKELY BRING A CLOUDY AND DAMP END TO THE WORK WEEK. GFS/GEFS MEAN BOTH INDICATING A SLIGHTLY MORE EASTERLY TRACK THAN OTHER MDL DATA...RESULTING IN LIGHTER QPF THAN ECMWF MEAN/CMC/NAM SOLUTIONS. FOR NOW...HAVE RAMPED UP POPS ACROSS THE ENTIRE AREA THURSDAY...BASED ON ALL MDL DATA INDICATING ARRIVAL OF ANOMALOUS EASTERLY FLOW AND PWATS...FOCUSED ESP ACROSS SE PA. BLENDED MDL QPF YIELDS 2 DAY RAINFALL TOTALS THU-FRI RANGING FROM ALMOST NOTHING ACROSS WARREN CO...TO ARND 1.5 INCHES ACROSS THE EASTERN THIRD OF THE STATE. HIGH FFG NUMBERS INDICATE THIS WOULD BE A BENEFICIAL RAIN...RATHER THAN A FLOOD THREAT. UPPER LOW INDICATED BY ALL MDL DATA TO SLOWLY PASS OFF THE MID ATLANTIC COAST NEXT WEEKEND...BRINGING A RETURN TO DRIER WX. LG SCALE RIDGE OVR THE E COAST SUGGESTS TEMPS WILL RETURN TO SLIGHTLY ABV NORMAL LEVELS BY THE WEEKEND WITH THE BENEFIT OF A BIT OF SUNSHINE. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... BORDERLINE VFR/MVFR CIGS ARE EXPECTED ACROSS THE WRN MTNS /KBFD AND KJST/ OVERNIGHT IN THE CHILLY WNW FLOW. WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR FOG OVERNIGHT AS WELL. THE WET GROUND COMBINED WITH CLEARING SKIES AND SLACKENING WINDS COULD SUPPORT FOG IN SOME LOCATIONS. HOWEVER...DEWPOINTS HAVE BEEN FALLING BEHIND THE DEPARTING COLD FRONT. ADDITIONALLY...JUST ENOUGH OF A BREEZE MAY PERSIST IN SOME LOCATIONS TO DISCOURAGE FOG FORMATION. FOR NOW...JUST HINTED AT THE POTENTIAL FOR REDUCED VSBYS TOWARD DAYBREAK IN THE TAFS. CONDS WILL IMPROVE ON TUES...AS HIGH PRESSURE PASSES OVERHEAD. ANY LINGERING LOW CLOUDS/PATCHY FOG WILL DISSIPATE AS THE MORNING PROGRESSES...WITH VFR CONDS EXPECTED BY MIDDAY. PATCHY FOG IS POSSIBLE AGAIN TUES NIGHT...FOLLOWED BY A RETURN TO VFR CONDS WEDNESDAY. AFTER THAT...FLYING CONDS MAY BEGIN TO DETERIORATE LATER IN THE WEEK AS EASTERLY FLOW DEVELOPS ACROSS THE REGION BETWEEN DEPARTING HIGH PRESSURE AND AN AREA OF LOW PRESSURE THAT MAY TRY TO DEVELOP ALONG THE MID-ATLANTIC COAST. OUTLOOK... WED...PATCHY AM FOG. OTHERWISE VFR. WED NIGHT-SATURDAY...EASTERLY FLOW DEVELOPS ACROSS THE AREA...ACCOMPANIED BY POTENTIAL FOR REDUCED CIGS AND VSBYS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...GARTNER/EVANEGO
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1238 AM CDT TUE OCT 8 2013 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...VFR CONDITIONS TO PREVAIL FOR THE NEXT 24 HOURS AS HIGH PRESSURE AT THE SURFACE AND ALOFT WILL PROVIDE SUBSIDENCE ACROSS DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY. LIGHT WINDS OVERNIGHT WILL BECOME EAST TO SOUTHEAST AROUND 10 KNOTS BY THE AFTERNOON. && .PREV DISCUSSION... /ISSUED 641 PM CDT MON OCT 7 2013/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE CLEAR SKIES ACROSS THE CWA EARLY THIS EVENING. EXPECT VFR CONDITIONS TO PREVAIL THE REST OF TONIGHT INTO TUESDAY AS 500MB RIDGE ACROSS NORTHERN MEXICO AND WEST TEXAS AND SURFACE HIGH PRESSURE ACROSS SOUTH TX PROVIDES SUBSIDENCE ACROSS THE RIO GRANDE VALLEY. PREV DISCUSSION... /ISSUED 239 PM CDT MON OCT 7 2013/ SHORT TERM.../NOW THROUGH TUESDAY NIGHT/...AS MR. RODGERS WOULD SAY...IT IS A BEAUTIFUL DAY IN THE NEIGHBORHOOD...AND IT WILL REMAIN BEAUTIFUL THROUGH THE SHORT TERM PERIOD. MID LEVEL RIDGE MOVES INTO WESTERN TEXAS AND SURFACE RIDGE PARKS ITSELF OVER SOUTH TEXAS TONIGHT. ATMOSPHERE REMAINS VERY DRY WITH THE LIGHT OFFSHORE FLOW CONTINUING INTO TUESDAY BEFORE VEERING SOUTHEAST TUESDAY NIGHT. WARM DAYS AND COOL NIGHTS CONTINUE UNDER THE CLEAR SKIES AND LOW DEW POINT AIR. MODEL TEMPERATURES GUIDANCE REMAINS CONSISTENT BUT WILL TREND SLIGHTLY LOWER FOR OVERNIGHT LOWS AS EXCELLENT RADIATIONAL COOLING TAKES PLACE. A FEW DEGREES WARMER ON TUESDAY WITH FORECAST NUMBERS NOT STRAYING TO FAR GUIDANCE. AS WE HEAD INTO TUESDAY NIGHT SOUTHEAST WINDS RETURN ALBEIT WEAK. SOMEWHAT MODEST LOW LEVEL MOISTURE ADVECTION IN THE LOWER 3000 FEET...LIGHT WINDS AND MOSTLY CLEAR SKIES COULD RESULT IN SOME PATCHY GROUND FOG BY SUNRISE WEDNESDAY. UNSURE IF MOISTURE ADVECTION WILL BE SUFFICIENT FOR DENSE FOG FORMATION BUT VISIBILITIES COULD LOWER BELOW 1 MILE IN THE MORE FAVORED LOCATIONS IN THE KHBV KBKS AREAS. OVERNIGHT NIGHT LOWS WILL BE WARMER BUT STILL BELOW GUIDANCE VALUES WITH THE WEAK RETURN FLOW NOT ADDING MUCH WARM AIR ADVECTION AT THIS TIME. ENJOY IT NOW A/C MAY HAVE TO CRANKED UP SOON. LONG TERM.../WEDNESDAY THROUGH MONDAY NIGHT/... UPPER LEVEL TROUGH OVER THE WESTERN U.S. WILL DEPEND AND LIFT TO THE NORTHEAST ACROSS THE FOUR CORNERS REGION THURSDAY INTO FRIDAY. AT THE SURFACE...STRONG SURFACE LEE TROUGH DEVELOPS ENHANCING THE SOUTHEAST FLOW FROM THE CENTRAL PLAINS SOUTHWARD INTO SOUTH TEXAS REGION. EXPECT THIS BREEZE AFTERNOON THROUGH THURSDAY. WARM FRONT OVER THE SOUTHERN GULF WILL LIFT N/NW AS RIDGE BUILDS ACROSS THE REGION. THIS SURFACE LOW WILL SURGE DEEP LAYER MOISTURE FROM THE SOUTHERN GULF INTO THE CWA THURSDAY AND FRIDAY. THE 1000 TO 500 MB RH VALUES SHOWS AN INCREASE BETWEEN 60 TO 70 PERCENT THROUGH THE WEEKEND AS THE UPPER LEVEL LOW INTERACTS WITH RIDGE OVER SOUTH TEXAS. THIS WILL ENHANCE THE CHANCE OF SHOWERS AND THUNDERSTORMS TO DEVELOP OVER THE CWA FRIDAY AND INTO THE WEEKEND. DECIDED TO INCREASE POP FORECAST TO 20 PERCENT AT THIS TIME SINCE THERE IS GOOD AGREEMENT AND CONSISTENCY WITH THE GFS/ECMWF MODEL RUN. THE COASTAL COUNTIES ARE MORE FAVORABLE TO RECEIVE SOME RAINFALL FROM THIS MOISTURE SURGE. DAYTIME HIGHS WILL GRADUALLY WARM TO THE MID 90S THROUGH THE END OF THE LONG TERM FORECAST. BY NEXT WEEK...GULF MOISTURE WILL RAP AROUND THE PERIPHERY OF THE HIGH AND ENHANCE THUNDERSTORM ACTIVITY ALONG THE SIERRA MADRE AND CENTRAL TEXAS. THIS AREA OF CONVECTION WILL CONTINUE INTO TUESDAY UNTIL THE NEXT UPPER TROUGH DEEPENS PUSHING ALL THE MOISTURE OUT OF THE AREA POSSIBLY BY MID WEEK. MARINE...NOW THROUGH TUESDAY NIGHT...EXCELLENT MARINE CONDITIONS THROUGH TUESDAY NIGHT WITH SURFACE HIGH PRESSURE SETTLING OVER THE COASTAL WATERS. LIGHT NORTHEAST WINDS TONIGHT TO VEER EAST TUESDAY THEN SOUTHEAST TUESDAY NIGHT. SEAS CONTINUE TO FALL TONIGHT LOWERING TO 2 FEET OR LESS TUESDAY. WEDNESDAY THROUGH MONDAY NIGHT... SOUTHEAST WINDS RETURN WEDNESDAY AS THE HIGH PRESSURE BUILDS ACROSS THE AREA. THIS SOUTHEAST FLOW WILL INCREASE THURSDAY INTO FRIDAY AND BUILD SEAS BELOW ADVISORY CRITERIA THROUGH THE END OF THE WEEK. AN AREA OF LOW PRESSURE WILL MOVE NORTHWARD INTO THE MARINE ZONES THURSDAY INTO FRIDAY ENHANCING THE MOISTURE CONTENT IN THE AREA. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE SATURDAY THROUGH MONDAY OVER THE GULF WATERS AS THE ABUNDANT MOISTURE WILL BE HIGHEST OVER THE MARINE ZONES. NO SCA OR SCEC EXPECTED AT THIS TIME THROUGH MONDAY. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 68 88 74 89 / 0 0 0 10 BROWNSVILLE 66 90 70 90 / 0 0 0 10 HARLINGEN 64 90 69 91 / 0 0 0 10 MCALLEN 66 91 71 93 / 0 0 0 10 RIO GRANDE CITY 65 92 70 93 / 0 0 0 10 SOUTH PADRE ISLAND 74 87 75 88 / 0 0 0 10 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 63
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
138 PM EDT TUE OCT 8 2013 .SYNOPSIS... REGION WILL REMAIN BETWEEN HIGH PRESSURE WEDGING DOWN THE EAST SLOPES OF THE APPALACHIANS AND A LOW TRACKING SLOWLY NORTHEAST FROM OFF THE FLORIDA COAST THIS MORNING...TO OFF THE NORTH CAROLINA COAST ON FRIDAY. THE LOW MOVES FARTHER OFFSHORE WITH HIGH PRESSURE BUILDING OVER THE AREA FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM EDT TUESDAY... NOT A LOT OF CHANGES SINCE THE PREVIOUS UPDATE. THE ONLY ITEM OF FOCUS IS A TREND TOWARD INCREASING CLOUD COVER IN THE EAST AND SOUTHEAST PART OF THE AREA. THIS IN TURN IS EXPECTED TO KEEP HIGH TEMPERATURES IN THIS PART OF THE FORECAST ARE ABOUT TWO OR THREE DEGREES COOLER THAN PREVIOUSLY FORECAST. ALSO...WESTERN PARTS OF THE AREA FROM ROUGHLY RICHLANDS TO BLUEFIELD WILL BENEFIT FROM AN EASTERLY DOWNSLOPE COMPONENT. HAVE RAISED EXPECTED HIGHS BY ROUGHLY TWO TO THREE DEGREES IN THIS AREA. OTHERWISE...NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. AS OF 945 AM EDT TUESDAY... SOME VALLEY FOG STILL EXISTS OVER PARTS OF THE GREENBRIER VALLEY OF SOUTHEAST WEST VIRGINIA. SATELLITE IMAGERY IS CURRENTLY SHOWING A RAPID BURN-OFF...BUT SOME SPOTS STILL COULD HAVE SOME FOG THROUGH 1100 AM. MUCH OF THE DAY WILL BE INFLUENCED BY SURFACE HIGH PRESSURE OVER THE AREA ALLOWING FOR COOL AND DRY CONDITIONS. LOW PRESSURE OFF THE COAST OF FLORIDA WILL SLOWLY MAKE ITS WAY NORTHWARD. AS IT DOES...THERE WILL BE A INCREASING NE-E FLOW OFF THE ATLANTIC THAT WILL OVERSPREAD MOISTURE INTO OUR REGION. FOR THE MOST PART...THIS WILL MEAN AN INCREASE IN CLOUD COVER...ESPECIALLY IN THE SOUTHEAST PART OF THE AREA. HOWEVER...SOME OF THE MODEL GUIDANCE HINTS AT SOME VERY LIGHT PRECIPITATION REACHING...OR ALMOST REACHING...THIS SAME AREA BY SUNSET. HAVE CONTINUED THE MENTION OF A SLIGHT CHANCE OF LIGHT RAIN HERE. HAVE BACKED OFF ON THE SLIGHT CHANCE FARTHER WEST TOWARD THE FOOTHILLS AND NORTHERN MOUNTAINS OF NORTH CAROLINA. HAVE TWEAKED HOURLY TEMPERATURES...DEW POINTS...CLOUDS AND WIND SPEED/GUSTS TO REFLECT THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE EARLY AFTERNOON. AS OF 400 AM EDT TUESDAY... SHORT WAVE MOVING NORTHEAST THROUGH THE CAROLINAS HAS PUSHED HIGH CLOUDS BACK TO THE WEST VIRGINIA/VIRGINIA BORDER. EXPECT CLOUD COVER OVER MOST OF THE COUNTY WARNING AREA THIS MORNING. AT THE SURFACE...LOW PRESSURE WAS OFF THE EASTERN FLORIDA COAST. HIGH PRESSURE WAS CONTINUING TO BUILD FROM THE OHIO VALLEY INTO THE NORTHEAST UNITED STATES AND MID ATLANTIC REGION. BY THE END OF THE DAY THE CENTER OF THE HIGH WILL BE IN A FAVORABLE POSITION OVER NEW YORK AND PENNSYLVANIA FOR A WEDGE TO DEVELOP DOWN THE EAST SLOPES OF THE APPALACHIANS. THIS WEDGE WILL REMAIN IN PLACE THROUGH TONIGHT. MEANWHILE...THE COASTAL LOW WILL MOVE SLOWLY NORTHEAST. AS A RESULT DEEP NORTHEAST TO EAST WINDS WILL DEVELOP AT THE SURFACE. 850 MB WINDS BECOME EASTERLY TODAY WITH INCREASING SPEEDS OVERNIGHT. THIS WILL BRING ATLANTIC MOISTURE INTO THE COUNTY WARNING AREA BY THIS AFTERNOON. SREF...LOCAL WRF AND RAP MODELS HAD BEST ISENTROPIC LIFT AND DEEPEST MOISTURE SOUTH OF A LINE FROM AROUND CHARLOTTE COUNTY TO WILKES COUNTY. WENT SLIGHTLY BELOW GUIDANCE FOR MAXIMUM TEMPERATURES TODAY...ESPECIALLY IN THE SOUTHEAST COUNTIES OF THE FORECAST AREA WHERE LITTLE TO NO SUNSHINE IS EXPECTED. CLOUDS WILL LIMIT DROP IN TEMPERATURES TONIGHT IN THE SOUTHEAST SO WENT WITH MILDER MAV GUIDANCE FOR OVERNIGHT LOWS. STAYED WITH A BLEND OF MAV/MET FOR THE REST OF THE FORECAST AREA. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 325 AM EDT TUESDAY... IN A BLOCKING PATTERN...AN UPPER LEVEL LOW WILL GET STUCK OVER THE REGION WHILE AT THE SURFACE...HIGH PRESSURE WEDGES DOWN THE COAST. THESE TWO FEATURES WILL COMBINE TO KEEP LOW CLOUDS...RAIN AND DRIZZLE IN THE AREA THROUGH THE PERIOD. THE BEST CHANCE FOR MEASURABLE RAIN WILL RESIDE OVER THE PIEDMONT...AND POSSIBLY ALONG THE BLUE RIDGE. IF THE UPPER LEVEL LOW WOBBLES TO THE WEST (NAM/ECM)...MORE EASTERLY FLOW AND PASSING SHORT WAVES WILL BRING A GREATER CHANCE AND AREAL COVERAGE OF RAIN TO THE FORECAST AREA. IF THIS LOW DRIFTS TO THE EAST (GFS)...DRIER AIR WILL GET PULLED INTO THE AREA ON NORTH-NORTHWEST FLOW. PLACED MORE WEIGHT ON THE NAM/ECM AS HEIGHTS INCREASE OVER THE WESTERN ATLANTIC...WOBBLING THE LOW TO THE WEST. WITH LOW TEMPORAL/SPATIAL CONFIDENCE WITH REGARDS TO MEASURABLE RAINFALL...HAVE THE HIGHEST POPS ACROSS THE PIEDMONT AT 40 PERCENT...DECREASING TO 20 PERCENT WESTWARD. BOTH OF THESE FEATURES...BY THEMSELVES...WOULD PRODUCE COOLER THAN NORMAL TEMPERATURES. AREAS SEEING LOW CLOUDS AND RAIN WILL LIKELY HAVE AFTERNOON TEMPERATURES 10F-15F COOLER THAN NORMAL. LOCATIONS OUTSIDE OF THE WEDGE...BUT UNDER THE LOW...MAY ONLY HAVE TEMPERATURES 3F-6F BELOW NORMAL. WITH CLOUDS INSULATING THE AREA EACH NIGHT...TEMPERATURES DIFFERENCES BETWEEN NIGHT AND DAY WILL BE AROUND 10F OR LESS. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 100 PM EDT MONDAY... CONSENSUS OF MODELS/WPC GUIDANCE SEEMS BEST THIS PERIOD DEALING WITH UPPER TROUGH/CUTOFF OVER VA/CAROLINAS FRIDAY THROUGH THE WEEKEND...AND DEVELOPMENT LOW PRESSURE ALONG/EAST OF THE NC/VA COAST. THIS SOLUTION FAVORS KEEPING OUR AREA JUST ON THE WESTERN PERIPHERY OF DEEPER MOISTURE AND SHOWER CHANCES. LOWERED POPS SOME BASED ON THE TRENDS WITH SLIGHT/LOW CHANCE AT BEST MAINLY OVER THE NORTHERN AND EASTERN CWA. CLOUD COVER WILL BE VARIED FROM MOSTLY CLOUDY/OVC EAST AND NORTH OF ROANOKE TO MORE SUN DURING THE DAY ACROSS OUR SW CWA AROUND BOONE NC/MARION VA/BLUEFIELD WV. TEMPS WILL BE SEASONAL DURING THE DAY BUT A TAD MILDER AT NIGHT GIVEN CLOUD COVER...AND NO APPRECIABLE CHANGE IN 5H HEIGHTS. BY MONDAY...LOOKS AS IF THE MAIN TROUGH HEADS NORTHEAST OVER THE NEW ENGLAND/MID ATLANTIC COAST....WHILE THE 5H FLOW FLATTENS SOME WEST OF US ALLOWING A FRONT TO MOVE TOWARD US MON-TUE NEXT WEEK. AT THE MOMENT MONDAY SHOULD BE MAINLY DRY ALTHOUGH A FEW SHOWERS COULD PUSH INTO SE WV MONDAY AFTERNOON. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 130 PM EDT TUESDAY... JUST SOME HIGH CLOUDS ACROSS THE REGION THIS AFTERNOON. VFR CONDITIONS WILL CONTINUE TO DOMINATE ALL TAF LOCATIONS INTO THIS EVENING. FOG SHOULD ONLY AFFECT LWB AGAIN OVERNIGHT...WITH THE FOG ERODING BY 13Z. ALL OTHER TAF LOCATIONS ARE EXPECTED TO REMAIN VFR THROUGH THE EVENING. COASTAL LOW TRACKING ALONG THE COAST WILL BRING SOME UNCERTAINTY TO THE TAF PERIOD ON WEDNESDAY...SPECIFICALLY AT LYH AND DAN. EXPECT THAT SOME RAIN WILL BE IN THE AREA...BUT AT THIS POINT LEFT ANY MENTION OF PRECIP OUT OF THE TAF LOCATIONS. WHAT IS MORE CERTAIN IS THAT CEILINGS WILL LOWER AT THE EASTERN TAF LOCATIONS DURING THE DAY. MVFR CEILINGS ARE EXPECTED AT DAN BY THE END OF THE TAF PERIOD. DEPENDING ON THE WESTERN EXTENT OF ANY PRECIP CEILINGS MAY LOWER TO MVFR AT ROA/LYH AS WELL. BCB/LWB/BLF SHOULD REMAIN VFR THROUGH THE DAY ON WEDNESDAY. THE COASTAL LOW WILL CONTINUE TO DOMINATE THE TAF DISCUSSION THURSDAY AS LOW LEVEL FLOW WILL REMAIN EASTERLY BRINGING IN ADDITIONAL MOISTURE. MVFR/IFR CEILINGS WILL BE POSSIBLE AGAIN ON THURSDAY ESPECIALLY ALONG AND EAST OF THE BLUE RIDGE. THE LOW SHOULD SHIFT ENOUGH TO THE NORTH BY FRIDAY AND SATURDAY TO RETURN OUR FLOW TO THE NORTHWEST THUS REDUCING THE CHANCES OF SUB-VFR CEILINGS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...WP AVIATION...CF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1247 PM EDT TUE OCT 8 2013 .SYNOPSIS... REGION WILL REMAIN BETWEEN HIGH PRESSURE WEDGING DOWN THE EAST SLOPES OF THE APPALACHIANS AND A LOW TRACKING SLOWLY NORTHEAST FROM OFF THE FLORIDA COAST THIS MORNING...TO OFF THE NORTH CAROLINA COAST ON FRIDAY. THE LOW MOVES FARTHER OFFSHORE WITH HIGH PRESSURE BUILDING OVER THE AREA FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM EDT TUESDAY... NOT A LOT OF CHANGES SINCE THE PREVIOUS UPDATE. THE ONLY ITEM OF FOCUS IS A TREND TOWARD INCREASING CLOUD COVER IN THE EAST AND SOUTHEAST PART OF THE AREA. THIS IN TURN IS EXPECTED TO KEEP HIGH TEMPERATURES IN THIS PART OF THE FORECAST ARE ABOUT TWO OR THREE DEGREES COOLER THAN PREVIOUSLY FORECAST. ALSO...WESTERN PARTS OF THE AREA FROM ROUGHLY RICHLANDS TO BLUEFIELD WILL BENEFIT FROM AN EASTERLY DOWNSLOPE COMPONENT. HAVE RAISED EXPECTED HIGHS BY ROUGHLY TWO TO THREE DEGREES IN THIS AREA. OTHERWISE...NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. AS OF 945 AM EDT TUESDAY... SOME VALLEY FOG STILL EXISTS OVER PARTS OF THE GREENBRIER VALLEY OF SOUTHEAST WEST VIRGINIA. SATELLITE IMAGERY IS CURRENTLY SHOWING A RAPID BURN-OFF...BUT SOME SPOTS STILL COULD HAVE SOME FOG THROUGH 1100 AM. MUCH OF THE DAY WILL BE INFLUENCED BY SURFACE HIGH PRESSURE OVER THE AREA ALLOWING FOR COOL AND DRY CONDITIONS. LOW PRESSURE OFF THE COAST OF FLORIDA WILL SLOWLY MAKE ITS WAY NORTHWARD. AS IT DOES...THERE WILL BE A INCREASING NE-E FLOW OFF THE ATLANTIC THAT WILL OVERSPREAD MOISTURE INTO OUR REGION. FOR THE MOST PART...THIS WILL MEAN AN INCREASE IN CLOUD COVER...ESPECIALLY IN THE SOUTHEAST PART OF THE AREA. HOWEVER...SOME OF THE MODEL GUIDANCE HINTS AT SOME VERY LIGHT PRECIPITATION REACHING...OR ALMOST REACHING...THIS SAME AREA BY SUNSET. HAVE CONTINUED THE MENTION OF A SLIGHT CHANCE OF LIGHT RAIN HERE. HAVE BACKED OFF ON THE SLIGHT CHANCE FARTHER WEST TOWARD THE FOOTHILLS AND NORTHERN MOUNTAINS OF NORTH CAROLINA. HAVE TWEAKED HOURLY TEMPERATURES...DEW POINTS...CLOUDS AND WIND SPEED/GUSTS TO REFLECT THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE EARLY AFTERNOON. AS OF 400 AM EDT TUESDAY... SHORT WAVE MOVING NORTHEAST THROUGH THE CAROLINAS HAS PUSHED HIGH CLOUDS BACK TO THE WEST VIRGINIA/VIRGINIA BORDER. EXPECT CLOUD COVER OVER MOST OF THE COUNTY WARNING AREA THIS MORNING. AT THE SURFACE...LOW PRESSURE WAS OFF THE EASTERN FLORIDA COAST. HIGH PRESSURE WAS CONTINUING TO BUILD FROM THE OHIO VALLEY INTO THE NORTHEAST UNITED STATES AND MID ATLANTIC REGION. BY THE END OF THE DAY THE CENTER OF THE HIGH WILL BE IN A FAVORABLE POSITION OVER NEW YORK AND PENNSYLVANIA FOR A WEDGE TO DEVELOP DOWN THE EAST SLOPES OF THE APPALACHIANS. THIS WEDGE WILL REMAIN IN PLACE THROUGH TONIGHT. MEANWHILE...THE COASTAL LOW WILL MOVE SLOWLY NORTHEAST. AS A RESULT DEEP NORTHEAST TO EAST WINDS WILL DEVELOP AT THE SURFACE. 850 MB WINDS BECOME EASTERLY TODAY WITH INCREASING SPEEDS OVERNIGHT. THIS WILL BRING ATLANTIC MOISTURE INTO THE COUNTY WARNING AREA BY THIS AFTERNOON. SREF...LOCAL WRF AND RAP MODELS HAD BEST ISENTROPIC LIFT AND DEEPEST MOISTURE SOUTH OF A LINE FROM AROUND CHARLOTTE COUNTY TO WILKES COUNTY. WENT SLIGHTLY BELOW GUIDANCE FOR MAXIMUM TEMPERATURES TODAY...ESPECIALLY IN THE SOUTHEAST COUNTIES OF THE FORECAST AREA WHERE LITTLE TO NO SUNSHINE IS EXPECTED. CLOUDS WILL LIMIT DROP IN TEMPERATURES TONIGHT IN THE SOUTHEAST SO WENT WITH MILDER MAV GUIDANCE FOR OVERNIGHT LOWS. STAYED WITH A BLEND OF MAV/MET FOR THE REST OF THE FORECAST AREA. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 325 AM EDT TUESDAY... IN A BLOCKING PATTERN...AN UPPER LEVEL LOW WILL GET STUCK OVER THE REGION WHILE AT THE SURFACE...HIGH PRESSURE WEDGES DOWN THE COAST. THESE TWO FEATURES WILL COMBINE TO KEEP LOW CLOUDS...RAIN AND DRIZZLE IN THE AREA THROUGH THE PERIOD. THE BEST CHANCE FOR MEASURABLE RAIN WILL RESIDE OVER THE PIEDMONT...AND POSSIBLY ALONG THE BLUE RIDGE. IF THE UPPER LEVEL LOW WOBBLES TO THE WEST (NAM/ECM)...MORE EASTERLY FLOW AND PASSING SHORT WAVES WILL BRING A GREATER CHANCE AND AREAL COVERAGE OF RAIN TO THE FORECAST AREA. IF THIS LOW DRIFTS TO THE EAST (GFS)...DRIER AIR WILL GET PULLED INTO THE AREA ON NORTH-NORTHWEST FLOW. PLACED MORE WEIGHT ON THE NAM/ECM AS HEIGHTS INCREASE OVER THE WESTERN ATLANTIC...WOBBLING THE LOW TO THE WEST. WITH LOW TEMPORAL/SPATIAL CONFIDENCE WITH REGARDS TO MEASURABLE RAINFALL...HAVE THE HIGHEST POPS ACROSS THE PIEDMONT AT 40 PERCENT...DECREASING TO 20 PERCENT WESTWARD. BOTH OF THESE FEATURES...BY THEMSELVES...WOULD PRODUCE COOLER THAN NORMAL TEMPERATURES. AREAS SEEING LOW CLOUDS AND RAIN WILL LIKELY HAVE AFTERNOON TEMPERATURES 10F-15F COOLER THAN NORMAL. LOCATIONS OUTSIDE OF THE WEDGE...BUT UNDER THE LOW...MAY ONLY HAVE TEMPERATURES 3F-6F BELOW NORMAL. WITH CLOUDS INSULATING THE AREA EACH NIGHT...TEMPERATURES DIFFERENCES BETWEEN NIGHT AND DAY WILL BE AROUND 10F OR LESS. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 100 PM EDT MONDAY... CONSENSUS OF MODELS/WPC GUIDANCE SEEMS BEST THIS PERIOD DEALING WITH UPPER TROUGH/CUTOFF OVER VA/CAROLINAS FRIDAY THROUGH THE WEEKEND...AND DEVELOPMENT LOW PRESSURE ALONG/EAST OF THE NC/VA COAST. THIS SOLUTION FAVORS KEEPING OUR AREA JUST ON THE WESTERN PERIPHERY OF DEEPER MOISTURE AND SHOWER CHANCES. LOWERED POPS SOME BASED ON THE TRENDS WITH SLIGHT/LOW CHANCE AT BEST MAINLY OVER THE NORTHERN AND EASTERN CWA. CLOUD COVER WILL BE VARIED FROM MOSTLY CLOUDY/OVC EAST AND NORTH OF ROANOKE TO MORE SUN DURING THE DAY ACROSS OUR SW CWA AROUND BOONE NC/MARION VA/BLUEFIELD WV. TEMPS WILL BE SEASONAL DURING THE DAY BUT A TAD MILDER AT NIGHT GIVEN CLOUD COVER...AND NO APPRECIABLE CHANGE IN 5H HEIGHTS. BY MONDAY...LOOKS AS IF THE MAIN TROUGH HEADS NORTHEAST OVER THE NEW ENGLAND/MID ATLANTIC COAST....WHILE THE 5H FLOW FLATTENS SOME WEST OF US ALLOWING A FRONT TO MOVE TOWARD US MON-TUE NEXT WEEK. AT THE MOMENT MONDAY SHOULD BE MAINLY DRY ALTHOUGH A FEW SHOWERS COULD PUSH INTO SE WV MONDAY AFTERNOON. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 735 AM EDT TUESDAY... THE REGION WILL BE BETWEEN HIGH PRESSURE OVER THE OHIO VALLEY AND LOW PRESSURE CENTERED OVER FLORIDA. MUCH LOWER DEW POINTS HAVE ARRIVED IN THE AREA BEHIND THE STRONG COLD FRONT THAT COME THROUGH ON MONDAY. EXPECT SHALLOW RIVER FOG AT KLWB WITH LIFR VISIBILITIES THROUGH 14Z/10AM. CIRRUS WILL COVER MUCH OF THE VIRGINIA THIS MORNING. AS A SHORT WAVE MOVES THROUGH NORTH CAROLINA THERE WILL BE MORE BREAKS IN THE CLOUD COVER THIS AFTERNOON. CEILINGS WILL REMAIN VFR. TODAY INTO THURSDAY THE FLORIDA THE COASTAL LOW WILL TRACK NORTH ALONG THE EAST COAST. LOW LEVEL FLOW INTO THE REGION WILL REMAIN EAST TO NORTHEAST...AND BECOME PROGRESSIVELY MOIST AS IT TAPS THE WESTERN ATLANTIC. LOOK FOR AN LOWERING CEILING AND SOME LIGHT PRECIPITATION IN KDAN LATE TONIGHT. AREAS OF IFR CONDITIONS ARE EXPECTED BY WEDNESDAY...ESPECIALLY ALONG AND EAST OF THE BLUE RIDGE WHERE MOISTURE WILL POOL. FRIDAY INTO SATURDAY THE LOW IS EXPECTED TO BE FAR ENOUGH NORTH SO THAT LOW LEVEL FLOW WILL BACK TO THE NORTHWEST. THIS SHOULD HELP REDUCE THE AREAL COVERAGE OF SUB-VFR CEILINGS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...WP AVIATION...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
952 AM EDT TUE OCT 8 2013 .SYNOPSIS... REGION WILL REMAIN BETWEEN HIGH PRESSURE WEDGING DOWN THE EAST SLOPES OF THE APPALACHIANS AND A LOW TRACKING SLOWLY NORTHEAST FROM OFF THE FLORIDA COAST THIS MORNING...TO OFF THE NORTH CAROLINA COAST ON FRIDAY. THE LOW MOVES FARTHER OFFSHORE WITH HIGH PRESSURE BUILDING OVER THE AREA FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM EDT TUESDAY... SOME VALLEY FOG STILL EXISTS OVER PARTS OF THE GREENBRIER VALLEY OF SOUTHEAST WEST VIRGINIA. SATELLITE IMAGERY IS CURRENTLY SHOWING A RAPID BURN-OFF...BUT SOME SPOTS STILL COULD HAVE SOME FOG THROUGH 1100 AM. MUCH OF THE DAY WILL BE INFLUENCED BY SURFACE HIGH PRESSURE OVER THE AREA ALLOWING FOR COOL AND DRY CONDITIONS. LOW PRESSURE OFF THE COAST OF FLORIDA WILL SLOWLY MAKE ITS WAY NORTHWARD. AS IT DOES...THERE WILL BE A INCREASING NE-E FLOW OFF THE ATLANTIC THAT WILL OVERSPREAD MOISTURE INTO OUR REGION. FOR THE MOST PART...THIS WILL MEAN AN INCREASE IN CLOUD COVER...ESPECIALLY IN THE SOUTHEAST PART OF THE AREA. HOWEVER...SOME OF THE MODEL GUIDANCE HINTS AT SOME VERY LIGHT PRECIPITATION REACHING...OR ALMOST REACHING...THIS SAME AREA BY SUNSET. HAVE CONTINUED THE MENTION OF A SLIGHT CHANCE OF LIGHT RAIN HERE. HAVE BACKED OFF ON THE SLIGHT CHANCE FARTHER WEST TOWARD THE FOOTHILLS AND NORTHERN MOUNTAINS OF NORTH CAROLINA. HAVE TWEAKED HOURLY TEMPERATURES...DEW POINTS...CLOUDS AND WIND SPEED/GUSTS TO REFLECT THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE EARLY AFTERNOON. AS OF 400 AM EDT TUESDAY... SHORT WAVE MOVING NORTHEAST THROUGH THE CAROLINAS HAS PUSHED HIGH CLOUDS BACK TO THE WEST VIRGINIA/VIRGINIA BORDER. EXPECT CLOUD COVER OVER MOST OF THE COUNTY WARNING AREA THIS MORNING. AT THE SURFACE...LOW PRESSURE WAS OFF THE EASTERN FLORIDA COAST. HIGH PRESSURE WAS CONTINUING TO BUILD FROM THE OHIO VALLEY INTO THE NORTHEAST UNITED STATES AND MID ATLANTIC REGION. BY THE END OF THE DAY THE CENTER OF THE HIGH WILL BE IN A FAVORABLE POSITION OVER NEW YORK AND PENNSYLVANIA FOR A WEDGE TO DEVELOP DOWN THE EAST SLOPES OF THE APPALACHIANS. THIS WEDGE WILL REMAIN IN PLACE THROUGH TONIGHT. MEANWHILE...THE COASTAL LOW WILL MOVE SLOWLY NORTHEAST. AS A RESULT DEEP NORTHEAST TO EAST WINDS WILL DEVELOP AT THE SURFACE. 850 MB WINDS BECOME EASTERLY TODAY WITH INCREASING SPEEDS OVERNIGHT. THIS WILL BRING ATLANTIC MOISTURE INTO THE COUNTY WARNING AREA BY THIS AFTERNOON. SREF...LOCAL WRF AND RAP MODELS HAD BEST ISENTROPIC LIFT AND DEEPEST MOISTURE SOUTH OF A LINE FROM AROUND CHARLOTTE COUNTY TO WILKES COUNTY. WENT SLIGHTLY BELOW GUIDANCE FOR MAXIMUM TEMPERATURES TODAY...ESPECIALLY IN THE SOUTHEAST COUNTIES OF THE FORECAST AREA WHERE LITTLE TO NO SUNSHINE IS EXPECTED. CLOUDS WILL LIMIT DROP IN TEMPERATURES TONIGHT IN THE SOUTHEAST SO WENT WITH MILDER MAV GUIDANCE FOR OVERNIGHT LOWS. STAYED WITH A BLEND OF MAV/MET FOR THE REST OF THE FORECAST AREA. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 325 AM EDT TUESDAY... IN A BLOCKING PATTERN...AN UPPER LEVEL LOW WILL GET STUCK OVER THE REGION WHILE AT THE SURFACE...HIGH PRESSURE WEDGES DOWN THE COAST. THESE TWO FEATURES WILL COMBINE TO KEEP LOW CLOUDS...RAIN AND DRIZZLE IN THE AREA THROUGH THE PERIOD. THE BEST CHANCE FOR MEASURABLE RAIN WILL RESIDE OVER THE PIEDMONT...AND POSSIBLY ALONG THE BLUE RIDGE. IF THE UPPER LEVEL LOW WOBBLES TO THE WEST (NAM/ECM)...MORE EASTERLY FLOW AND PASSING SHORT WAVES WILL BRING A GREATER CHANCE AND AREAL COVERAGE OF RAIN TO THE FORECAST AREA. IF THIS LOW DRIFTS TO THE EAST (GFS)...DRIER AIR WILL GET PULLED INTO THE AREA ON NORTH-NORTHWEST FLOW. PLACED MORE WEIGHT ON THE NAM/ECM AS HEIGHTS INCREASE OVER THE WESTERN ATLANTIC...WOBBLING THE LOW TO THE WEST. WITH LOW TEMPORAL/SPATIAL CONFIDENCE WITH REGARDS TO MEASURABLE RAINFALL...HAVE THE HIGHEST POPS ACROSS THE PIEDMONT AT 40 PERCENT...DECREASING TO 20 PERCENT WESTWARD. BOTH OF THESE FEATURES...BY THEMSELVES...WOULD PRODUCE COOLER THAN NORMAL TEMPERATURES. AREAS SEEING LOW CLOUDS AND RAIN WILL LIKELY HAVE AFTERNOON TEMPERATURES 10F-15F COOLER THAN NORMAL. LOCATIONS OUTSIDE OF THE WEDGE...BUT UNDER THE LOW...MAY ONLY HAVE TEMPERATURES 3F-6F BELOW NORMAL. WITH CLOUDS INSULATING THE AREA EACH NIGHT...TEMPERATURES DIFFERENCES BETWEEN NIGHT AND DAY WILL BE AROUND 10F OR LESS. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 100 PM EDT MONDAY... CONSENSUS OF MODELS/WPC GUIDANCE SEEMS BEST THIS PERIOD DEALING WITH UPPER TROUGH/CUTOFF OVER VA/CAROLINAS FRIDAY THROUGH THE WEEKEND...AND DEVELOPMENT LOW PRESSURE ALONG/EAST OF THE NC/VA COAST. THIS SOLUTION FAVORS KEEPING OUR AREA JUST ON THE WESTERN PERIPHERY OF DEEPER MOISTURE AND SHOWER CHANCES. LOWERED POPS SOME BASED ON THE TRENDS WITH SLIGHT/LOW CHANCE AT BEST MAINLY OVER THE NORTHERN AND EASTERN CWA. CLOUD COVER WILL BE VARIED FROM MOSTLY CLOUDY/OVC EAST AND NORTH OF ROANOKE TO MORE SUN DURING THE DAY ACROSS OUR SW CWA AROUND BOONE NC/MARION VA/BLUEFIELD WV. TEMPS WILL BE SEASONAL DURING THE DAY BUT A TAD MILDER AT NIGHT GIVEN CLOUD COVER...AND NO APPRECIABLE CHANGE IN 5H HEIGHTS. BY MONDAY...LOOKS AS IF THE MAIN TROUGH HEADS NORTHEAST OVER THE NEW ENGLAND/MID ATLANTIC COAST....WHILE THE 5H FLOW FLATTENS SOME WEST OF US ALLOWING A FRONT TO MOVE TOWARD US MON-TUE NEXT WEEK. AT THE MOMENT MONDAY SHOULD BE MAINLY DRY ALTHOUGH A FEW SHOWERS COULD PUSH INTO SE WV MONDAY AFTERNOON. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... AS OF 735 AM EDT TUESDAY... THE REGION WILL BE BETWEEN HIGH PRESSURE OVER THE OHIO VALLEY AND LOW PRESSURE CENTERED OVER FLORIDA. MUCH LOWER DEW POINTS HAVE ARRIVED IN THE AREA BEHIND THE STRONG COLD FRONT THAT COME THROUGH ON MONDAY. EXPECT SHALLOW RIVER FOG AT KLWB WITH LIFR VISIBILITIES THROUGH 14Z/10AM. CIRRUS WILL COVER MUCH OF THE VIRGINIA THIS MORNING. AS A SHORT WAVE MOVES THROUGH NORTH CAROLINA THERE WILL BE MORE BREAKS IN THE CLOUD COVER THIS AFTERNOON. CEILINGS WILL REMAIN VFR. TODAY INTO THURSDAY THE FLORIDA THE COASTAL LOW WILL TRACK NORTH ALONG THE EAST COAST. LOW LEVEL FLOW INTO THE REGION WILL REMAIN EAST TO NORTHEAST...AND BECOME PROGRESSIVELY MOIST AS IT TAPS THE WESTERN ATLANTIC. LOOK FOR AN LOWERING CEILING AND SOME LIGHT PRECIPITATION IN KDAN LATE TONIGHT. AREAS OF IFR CONDITIONS ARE EXPECTED BY WEDNESDAY...ESPECIALLY ALONG AND EAST OF THE BLUE RIDGE WHERE MOISTURE WILL POOL. FRIDAY INTO SATURDAY THE LOW IS EXPECTED TO BE FAR ENOUGH NORTH SO THAT LOW LEVEL FLOW WILL BACK TO THE NORTHWEST. THIS SHOULD HELP REDUCE THE AREAL COVERAGE OF SUB-VFR CEILINGS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...WP AVIATION...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
414 AM EDT TUE OCT 8 2013 .SYNOPSIS... REGION WILL REMAIN BETWEEN HIGH PRESSURE WEDGING DOWN THE EAST SLOPES OF THE APPALACHIANS AND A LOW TRACKING SLOWLY NORTHEAST FROM OFF THE FLORIDA COAST THIS MORNING...TO OFF THE NORTH CAROLINA COAST ON FRIDAY. THE LOW MOVES FARTHER OFFSHORE WITH HIGH PRESSURE BUILDING OVER THE AREA FOR SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT TUESDAY... SHORT WAVE MOVING NORTHEAST THROUGH THE CAROLINAS HAS PUSHED HIGH CLOUDS BACK TO THE WEST VIRGINIA/VIRGINIA BORDER. EXPECT CLOUD COVER OVER MOST OF THE COUNTY WARNING AREA THIS MORNING. AT THE SURFACE...LOW PRESSURE WAS OFF THE EASTERN FLORIDA COAST. HIGH PRESSURE WAS CONTINUING TO BUILD FROM THE OHIO VALLEY INTO THE NORTHEAST UNITED STATES AND MID ATLANTIC REGION. BY THE END OF THE DAY THE CENTER OF THE HIGH WILL BE IN A FAVORABLE POSITION OVER NEW YORK AND PENNSYLVANIA FOR A WEDGE TO DEVELOP DOWN THE EAST SLOPES OF THE APPALACHIANS. THIS WEDGE WILL REMAIN IN PLACE THROUGH TONIGHT. MEANWHILE...THE COASTAL LOW WILL MOVE SLOWLY NORTHEAST. AS A RESULT DEEP NORTHEAST TO EAST WINDS WILL DEVELOP AT THE SURFACE. 850 MB WINDS BECOME EASTERLY TODAY WITH INCREASING SPEEDS OVERNIGHT. THIS WILL BRING ATLANTIC MOISTURE INTO THE COUNTY WARNING AREA BY THIS AFTERNOON. SREF...LOCAL WRF AND RAP MODELS HAD BEST ISENTROPIC LIFT AND DEEPEST MOISTURE SOUTH OF A LINE FROM AROUND CHARLOTTE COUNTY TO WILKES COUNTY. WENT SLIGHTLY BELOW GUIDANCE FOR MAXIMUM TEMPERATURES TODAY...ESPECIALLY IN THE SOUTHEAST COUNTIES OF THE FORECAST AREA WHERE LITTLE TO NO SUNSHINE IS EXPECTED. CLOUDS WILL LIMIT DROP IN TEMPERATURES TONIGHT IN THE SOUTHEAST SO WENT WITH MILDER MAV GUIDANCE FOR OVERNIGHT LOWS. STAYED WITH A BLEND OF MAV/MET FOR THE REST OF THE FORECAST AREA. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 325 AM EDT TUESDAY... IN A BLOCKING PATTERN...AN UPPER LEVEL LOW WILL GET STUCK OVER THE REGION WHILE AT THE SURFACE...HIGH PRESSURE WEDGES DOWN THE COAST. THESE TWO FEATURES WILL COMBINE TO KEEP LOW CLOUDS...RAIN AND DRIZZLE IN THE AREA THROUGH THE PERIOD. THE BEST CHANCE FOR MEASURABLE RAIN WILL RESIDE OVER THE PIEDMONT...AND POSSIBLY ALONG THE BLUE RIDGE. IF THE UPPER LEVEL LOW WOBBLES TO THE WEST (NAM/ECM)...MORE EASTERLY FLOW AND PASSING SHORT WAVES WILL BRING A GREATER CHANCE AND AREAL COVERAGE OF RAIN TO THE FORECAST AREA. IF THIS LOW DRIFTS TO THE EAST (GFS)...DRIER AIR WILL GET PULLED INTO THE AREA ON NORTH-NORTHWEST FLOW. PLACED MORE WEIGHT ON THE NAM/ECM AS HEIGHTS INCREASE OVER THE WESTERN ATLANTIC...WOBBLING THE LOW TO THE WEST. WITH LOW TEMPORAL/SPATIAL CONFIDENCE WITH REGARDS TO MEASURABLE RAINFALL...HAVE THE HIGHEST POPS ACROSS THE PIEDMONT AT 40 PERCENT...DECREASING TO 20 PERCENT WESTWARD. BOTH OF THESE FEATURES...BY THEMSELVES...WOULD PRODUCE COOLER THAN NORMAL TEMPERATURES. AREAS SEEING LOW CLOUDS AND RAIN WILL LIKELY HAVE AFTERNOON TEMPERATURES 10F-15F COOLER THAN NORMAL. LOCATIONS OUTSIDE OF THE WEDGE...BUT UNDER THE LOW...MAY ONLY HAVE TEMPERATURES 3F-6F BELOW NORMAL. WITH CLOUDS INSULATING THE AREA EACH NIGHT...TEMPERATURES DIFFERENCES BETWEEN NIGHT AND DAY WILL BE AROUND 10F OR LESS. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 100 PM EDT MONDAY... CONSENSUS OF MODELS/WPC GUIDANCE SEEMS BEST THIS PERIOD DEALING WITH UPPER TROUGH/CUTOFF OVER VA/CAROLINAS FRIDAY THROUGH THE WEEKEND...AND DEVELOPMENT LOW PRESSURE ALONG/EAST OF THE NC/VA COAST. THIS SOLUTION FAVORS KEEPING OUR AREA JUST ON THE WESTERN PERIPHERY OF DEEPER MOISTURE AND SHOWER CHANCES. LOWERED POPS SOME BASED ON THE TRENDS WITH SLIGHT/LOW CHANCE AT BEST MAINLY OVER THE NORTHERN AND EASTERN CWA. CLOUD COVER WILL BE VARIED FROM MOSTLY CLOUDY/OVC EAST AND NORTH OF ROANOKE TO MORE SUN DURING THE DAY ACROSS OUR SW CWA AROUND BOONE NC/MARION VA/BLUEFIELD WV. TEMPS WILL BE SEASONAL DURING THE DAY BUT A TAD MILDER AT NIGHT GIVEN CLOUD COVER...AND NO APPRECIABLE CHANGE IN 5H HEIGHTS. BY MONDAY...LOOKS AS IF THE MAIN TROUGH HEADS NORTHEAST OVER THE NEW ENGLAND/MID ATLANTIC COAST....WHILE THE 5H FLOW FLATTENS SOME WEST OF US ALLOWING A FRONT TO MOVE TOWARD US MON-TUE NEXT WEEK. AT THE MOMENT MONDAY SHOULD BE MAINLY DRY ALTHOUGH A FEW SHOWERS COULD PUSH INTO SE WV MONDAY AFTERNOON. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... AS OF 140 AM EDT TUESDAY... THE REGION WILL BE BETWEEN HIGH PRESSURE OVER THE OHIO VALLEY AND LOW PRESSURE CENTERED OVER FLORIDA. MUCH LOWER DEW POINTS HAVE ARRIVED IN THE AREA BEHIND THE STRONG COLD FRONT THAT COME THROUGH ON MONDAY. EVEN WITH THE CLEAR SKY AND LIGHT WIND EARLY THIS MORNING CONFIDENCE IS ONLY MODERATE OF FOG DEVELOPMENT. AIR MASS IS COOL ENOUGH THAT FOG MAY FORM OVER THE WARMER RIVERS THEN DRIFT INTO KLWB AND KBCB. THE NORTHERN EDGE OF CLOUD COVER WILL KEEP CIRRUS OVER KLYH AND KDAN THROUGH THE TAF PERIOD. FARTHER WEST EXPECT VFR CONDITIONS WITH ONLY GRADUALLY INCREASING HIGH CLOUDS. TODAY INTO THURSDAY THE FLORIDA LOW WILL TRACK NORTH ALONG THE EAST COAST. LOW LEVEL FLOW INTO THE REGION WILL REMAIN EAST TO NORTHEAST...AND BECOME PROGRESSIVELY MOIST AS IT TAPS THE WESTERN ATLANTIC. LOOK FOR AN INCREASE IN CLOUD COVER AND SOME LIGHT PRECIPITATION. AREAS OF IFR CONDITIONS ARE EXPECTED BY WEDNESDAY...ESPECIALLY ALONG AND EAST OF THE BLUE RIDGE WHERE MOISTURE WILL POOL. FRIDAY INTO SATURDAY THE LOW IS EXPECTED TO BE FAR ENOUGH NORTH SO THAT LOW LEVEL FLOW WILL BACK TO THE NORTHWEST. THIS SHOULD HELP REDUCE THE AREAL COVERAGE OF SUB-VFR CEILINGS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...RCS LONG TERM...WP AVIATION...AMS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
858 PM CDT WED OCT 9 2013 .UPDATE... && .AVIATION/06Z TAFS/... LIGHTER WIND REGIME IN THE BOUNDARY LEVEL TONIGHT SO SOME CONCERN FOR FOG IN THE EASTERN INLAND AREAS...POTENTIALLY AFFECTING THE KENW/KUES CORRIDOR. SREF PROBS WERE LOW BUT THE HRRR BRINGS VSBYS DOWN TO 1/4 MILE FROM SOUTH OF SHEBOYGAN TO KENOSHA. WILL INCLUDE SOME FOG BUT NOT GO QUITE AS LOW AS THE HRRR AND KENOSHA MOS SUGGESTS AT THIS POINT. IF THIS DID OCCUR IT WOULD LIKELY BE IN THE TYPICAL LOW AREA/RIVER VALLEYS UNTIL 13Z. OTHERWISE MOSTLY CLEAR SKIES WITH ONLY SOME SCATTERED CIRRUS. && .PREV DISCUSSION... /ISSUED 306 PM CDT WED OCT 9 2013/ TONIGHT AND THURSDAY - CONFIDENCE...HIGH QUIET WEATHER CONTINUES. HIGH PRESSURE REMAINS ACROSS THE EASTERN U.S. WITH A NEARLY STATIONARY TROUGH OF LOW PRESSURE IN THE PLAINS. THE SOUTHERLY FLOW PERSISTS WITH AN ONSHORE FLOW AS WELL. AIRMASS REMAINS DRY WITH ONLY A BIT OF CIRRUS. 925 TEMPS SUPPORT MORE IN THE WAY OF ABOVE NORMAL TEMPERATURES. THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE IS HIGH. HIGH PRESSURE EXITS TO THE EAST WHILE STRONG LOW PRESSURE MOVES FROM THE HIGH PLAINS OF ERN COLORADO...NORTHEAST TO EASTERN NORTH DAKOTA BY FRIDAY EVENING. THE TIGHTENING PRESSURE GRADIENT WILL BRING BREEZY SOUTHERLY WINDS TO SOUTHERN WISCONSIN BY FRIDAY AFTERNOON. GUSTS COULD REACH 30 MPH WEST OF MADISON...LOWER IN THE EAST. THE STRONGEST WINDS JUST OFF THE SURFACE ARRIVE FRIDAY EVENING...BUT WE DECOUPLE WITH SUNSET WHICH WILL LIMIT WIND SPEEDS. OTHERWISE...STILL DRY AND WARM FOR MID OCTOBER. FRIDAY NIGHT AND SATURDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. A COLD FRONT ASSOCIATED WITH THE LOW TRACKING NORTH INTO CANADA WILL SWEEP THROUGH ON SATURDAY. SHOWERS ALONG AND AHEAD OF IT COULD ARRIVE IN THE WEST AFTER MIDNIGHT FRIDAY NIGHT. THE MODELS ARE IN BETTER AGREEMENT WITH TIMING. THERE IS A SECONDARY MID LEVEL SHORT WAVE THAT SWINGS NORTHEAST INTO THE AREA ON SATURDAY...ENHANCING THE FROTOGENESIS AND OMEGA WITH THE FRONT. IN ADDITION...ALTHOUGH MOISTURE WILL BE LACKING WITH THE FRONT WHEN IT IS UPSTREAM...WE SHOULD SEE A RIBBON OF HIGHER DEWPOINTS MOVE INTO THE AREA. ALL THIS LOOKS TO COME TOGETHER ACROSS THE AREA ON SATURDAY...SO WILL MAINTAIN HIGH CHC POPS FOR NOW...AND IF CONFIDENCE INCREASES...THOSE POPS WILL RISE. THERE IS SOME CAPE...BUT NOT IMPRESSIVE...SO WILL MAINTAIN JUST A SLIGHT CHANCE OF STORMS. LOOKING AT TIMING...AREAS WEST OF MADISON MAY BE CLEARING OUT BY AFTERNOON WITH THE RAIN ENDING BY EARLY EVENING IN THE EAST. SUNDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM TO HIGH. COOLER HIGH PRESSURE ARRIVES IN THE WAKE OF THE LOW WITH TEMPERATURES FALLING BACK TO LEVELS MORE NORMAL FOR THE TIME OF YEAR. TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM. A NICE MEATY SYNOPTIC SYSTEM IS EXPECTED TO COME THROUGH DURING THIS PERIOD. IT/S STARTING TO LOOK MORE FALL-LIKE WITH THESE TYPES OF SYSTEMS SPINNING THROUGH. THE GFS AND ECMWF WERE AT ODDS ON TIMING OVER THE LAST FEW RUNS...BUT HAVE COME INTO SYNC WITH BOTH THE TIMING AND THE GENERAL TRACK OF THE LOW. RAIN SHOULD MOVE LATE MONDAY NIGHT AND CONTINUE INTO WEDNESDAY MORNING. THE HEAVIEST RAIN LOOKS TO BE TUESDAY AFTERNOON AND EVENING. NO FEAR OF ANY SNOW FLAKES AS TEMPERATURES WILL BE TOO WARM. THEN EVEN COOLER TEMPERATURES ARRIVE LATE NEXT WEEK. AVIATION/00Z TAFS/...VFR MOSTLY SKC THIS PERIOD. LIGHTER WIND REGIME OFF THE DECK TONIGHT SO SOME CONCERN FOR FOG IN THE EASTERN INLAND AREAS...POTENTIALLY AFFECTING THE KENW/KUES CORRIDOR. SREF PROBS ARE VERY LOW. SO FOR NOW WILL INCLUDE SOME FOG BUT NOT GO QUITE AS LOW AS MOS SUGGESTS AT THIS POINT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...HENTZ TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR THURSDAY NIGHT THROUGH WEDNESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1248 PM CDT TUE OCT 8 2013 .SHORT TERM...(TODAY INTO WEDNESDAY) ISSUED AT 309 AM CDT TUE OCT 8 2013 AT 3 AM...LATEST WATER VAPOR IMAGERY AND RAP 500 MB HEIGHT ANALYSIS SHOWED A UPPER LEVEL RIDGE AXIS CENTERED ACROSS THE UPPER MIDWEST...WITH A DIGGING LONGWAVE TROUGH ENTERING THE PACIFIC NORTHWEST. AT THE SURFACE...HIGH PRESSURE OVER THE OHIO RIVER VALLEY CONTINUES TO SLIDE SOUTHEAST. THIS HAS SET THE STAGE FOR SOUTHERLY FLOW TO TAKE OVER...AS SEEN ALREADY BY VWP FROM KDMX/KFSD/KOAX/KUEX/KTWX...THE SOURCE REGION FOR TODAYS AIR MASS. A BREEZY DAY IS ON TAP AS THE PRESSURE GRADIENT TIGHTENS ACROSS MINNESOTA AND IOWA IN RESPONSE TO DEVELOPING LOW PRESSURE ACROSS THE NORTHERN PLAINS. THE STRONGEST GRADIENT EXISTS FROM CENTRAL INTO SOUTHWEST MINNESOTA...BUT MOST LOCATIONS WEST OF THE MISSISSIPPI RIVER WILL BE QUITE BREEZY TODAY. FORECAST SOUNDINGS SHOW MOSTLY SUNNY SKIES AND MIXING UP TO AROUND 850 MB...AND THIS SHOULD HELP TO MIX DOWN SUSTAINED SOUTHERLY WINDS OF 20 TO 25 MPH WITH OCCASIONAL GUSTS 30 TO 35 MPH ACROSS THE OPEN AREAS OF MINNESOTA AND IOWA. FURTHER EAST INTO WISCONSIN...LESS OF A GRADIENT BUT STILL GOOD MECHANICAL MIXING WILL RESULT IN WINDS 15 MPH WITH GUSTS TO AROUND 20 TO 25 MPH. 850 AND 925 MB TEMPERATURES ARE EXPECTED TO INCREASE 5 TO 6C COMPARED TO YESTERDAY...AND THIS SHOULD RESULT IN A 8 TO 10F BUMP IN HIGH TEMPERATURES. LOOK FOR READINGS TO TOP OUT FROM 70 TO 75F...ABOUT 5 TO 10 DEGREES ABOVE NORMAL. FOR WEDNESDAY...CONTINUED DRY AND PLEASANT AUTUMN CONDITIONS FOR THE UPPER MIDWEST. PRESSURE GRADIENT LOOSENS SOME ACROSS THE AREA...LESS MIXING SEEN IN THE SOUNDINGS AND 850 MB TEMPERATURES A FEW DEGREES COOLER SHOULD KEEP HIGHS A COUPLE DEGREES COOLER THAN TODAY. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 309 AM CDT TUE OCT 8 2013 FORECAST TARGET IN THE LONG TERM IS ON PRECIPITATION CHANCES FRIDAY INTO THE WEEKEND. BY FRIDAY...THERE IS ABOVE NORMAL MODEL AGREEMENT AND CONSISTENCY IN THE UPPER LEVEL WEATHER PATTERN. THE WESTERN CONUS TROUGH DIGS...AND EJECTS ENERGY OUT OF THE ROCKIES. HOWEVER...THE DOWNSTREAM RIDGE ACROSS THE EASTERN CONUS IS BLOCKED AND THIS FORCES THE DEVELOPING SURFACE LOW ACROSS CENTRAL PLAINS TO LIFT INTO THE NORTHERN PLAINS. BY FRIDAY NIGHT INTO SATURDAY MORNING...THE SYSTEM APPROACHES AND DRAGS A COLD FRONT ACROSS THE FORECAST AREA. HOWEVER...UPPER LEVEL DYNAMIC FORCING REMAINS TO THE NORTH AND WEST...WHILE THE BEST LOW AND MID LEVEL THERMODYNAMICS LOOK TO RESIDE SOUTH. THIS SCENARIO WOULD SPLIT THE UPPER MISSISSIPPI RIVER VALLEY OF THE GREATEST PRECIPITATION...AND AT THIS TIME...LOW-END CHANCES FRIDAY NIGHT INTO SATURDAY ARE APPROPRIATE. HOWEVER...MODEL GUIDANCE CONSISTENCY DIVERGES BY SATURDAY NIGHT INTO SUNDAY. THERE ARE INDICATIONS THAT THE FRONT COULD STALL OVER OR JUST EAST OF THE FORECAST AREA...WHILE A SECONDARY PIECE OF UPPER LEVEL ENERGY ROUNDS THE BASE OF THE UPPER LEVEL TROUGH. FRONTOGENETICAL FORCING INCREASES...AND ALLOWS A DEFORMATION BAND OF RAIN TO DEVELOP SATURDAY NIGHT INTO SUNDAY AS A WEAK AREA OF LOW PRESSURE LIFTS NORTH TOWARD LAKE MICHIGAN. THE 07.12Z/08.00Z EC AND THE 08.00Z GEM SIMILARLY SHOW THIS SOLUTION...WHILE THE 08.00Z GFS PUSHES THE FRONT FURTHER EAST AND LACKS THE SECONDARY PIECE OF ENERGY...MAKING FOR A DRY FORECAST. AT THIS TIME...FAVORED THE EC / GEM SOLUTIONS...THOUGH GIVEN THE LACK OF STRONG MODEL AGREEMENT AND CONSISTENCY...ONLY INCREASED PRECIPITATION CHANCES BY ABOUT 10 PERCENT ABOVE THE CONSENSUS APPROACH. THIS YIELDED 20-40 PERCENT CHANCES ACROSS MOST OF THE AREA...HIGHEST ACROSS SOUTHWEST WISCONSIN. IF TRENDS CONTINUE TO POINT TOWARD A 08.00Z EC TYPE SOLUTION...THEN PRECIPITATION CHANCES WILL NEED TO BE RAISED SATURDAY NIGHT INTO SUNDAY MORNING. HIGH TEMPERATURES LOOK TO COOL BACK DOWN TO THE UPPER 50S TO LOWER 60S SATURDAY INTO SUNDAY...CLOSER TO NORMAL FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1243 PM CDT TUE OCT 8 2013 AS DIURNAL MIXING CONTINUES THIS AFTERNOON...EXPECT THE SOUTH WINDS TO GUST INTO THE 30 TO 35 KNOT RANGE WEST OF THE MISSISSIPPI RIVER AND 25 TO 30 KNOTS EAST OF THE MISSISSIPPI RIVER. THESE WIND GUSTS WILL QUICKLY DROP OFF BETWEEN 08.23Z AND 09.00Z WITH THE LOSS OF DIURNAL HEATING. AS THIS OCCURS...LOW LEVEL WIND SHEAR WILL DEVELOP IN THE LOWEST 1000 TO 1500 FEET AS THE LOW LEVEL JET CLIMBS INTO THE 40 TO 50 KNOT RANGE. THIS LOW LEVEL WIND SHEAR WILL THEN CONTINUE THROUGH 09.15Z. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...ZT LONG TERM....ZT AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
709 AM CDT TUE OCT 8 2013 .SHORT TERM...(TODAY INTO WEDNESDAY) ISSUED AT 309 AM CDT TUE OCT 8 2013 AT 3 AM...LATEST WATER VAPOR IMAGERY AND RAP 500 MB HEIGHT ANALYSIS SHOWED A UPPER LEVEL RIDGE AXIS CENTERED ACROSS THE UPPER MIDWEST...WITH A DIGGING LONGWAVE TROUGH ENTERING THE PACIFIC NORTHWEST. AT THE SURFACE...HIGH PRESSURE OVER THE OHIO RIVER VALLEY CONTINUES TO SLIDE SOUTHEAST. THIS HAS SET THE STAGE FOR SOUTHERLY FLOW TO TAKE OVER...AS SEEN ALREADY BY VWP FROM KDMX/KFSD/KOAX/KUEX/KTWX...THE SOURCE REGION FOR TODAYS AIR MASS. A BREEZY DAY IS ON TAP AS THE PRESSURE GRADIENT TIGHTENS ACROSS MINNESOTA AND IOWA IN RESPONSE TO DEVELOPING LOW PRESSURE ACROSS THE NORTHERN PLAINS. THE STRONGEST GRADIENT EXISTS FROM CENTRAL INTO SOUTHWEST MINNESOTA...BUT MOST LOCATIONS WEST OF THE MISSISSIPPI RIVER WILL BE QUITE BREEZY TODAY. FORECAST SOUNDINGS SHOW MOSTLY SUNNY SKIES AND MIXING UP TO AROUND 850 MB...AND THIS SHOULD HELP TO MIX DOWN SUSTAINED SOUTHERLY WINDS OF 20 TO 25 MPH WITH OCCASIONAL GUSTS 30 TO 35 MPH ACROSS THE OPEN AREAS OF MINNESOTA AND IOWA. FURTHER EAST INTO WISCONSIN...LESS OF A GRADIENT BUT STILL GOOD MECHANICAL MIXING WILL RESULT IN WINDS 15 MPH WITH GUSTS TO AROUND 20 TO 25 MPH. 850 AND 925 MB TEMPERATURES ARE EXPECTED TO INCREASE 5 TO 6C COMPARED TO YESTERDAY...AND THIS SHOULD RESULT IN A 8 TO 10F BUMP IN HIGH TEMPERATURES. LOOK FOR READINGS TO TOP OUT FROM 70 TO 75F...ABOUT 5 TO 10 DEGREES ABOVE NORMAL. FOR WEDNESDAY...CONTINUED DRY AND PLEASANT AUTUMN CONDITIONS FOR THE UPPER MIDWEST. PRESSURE GRADIENT LOOSENS SOME ACROSS THE AREA...LESS MIXING SEEN IN THE SOUNDINGS AND 850 MB TEMPERATURES A FEW DEGREES COOLER SHOULD KEEP HIGHS A COUPLE DEGREES COOLER THAN TODAY. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 309 AM CDT TUE OCT 8 2013 FORECAST TARGET IN THE LONG TERM IS ON PRECIPITATION CHANCES FRIDAY INTO THE WEEKEND. BY FRIDAY...THERE IS ABOVE NORMAL MODEL AGREEMENT AND CONSISTENCY IN THE UPPER LEVEL WEATHER PATTERN. THE WESTERN CONUS TROUGH DIGS...AND EJECTS ENERGY OUT OF THE ROCKIES. HOWEVER...THE DOWNSTREAM RIDGE ACROSS THE EASTERN CONUS IS BLOCKED AND THIS FORCES THE DEVELOPING SURFACE LOW ACROSS CENTRAL PLAINS TO LIFT INTO THE NORTHERN PLAINS. BY FRIDAY NIGHT INTO SATURDAY MORNING...THE SYSTEM APPROACHES AND DRAGS A COLD FRONT ACROSS THE FORECAST AREA. HOWEVER...UPPER LEVEL DYNAMIC FORCING REMAINS TO THE NORTH AND WEST...WHILE THE BEST LOW AND MID LEVEL THERMODYNAMICS LOOK TO RESIDE SOUTH. THIS SCENARIO WOULD SPLIT THE UPPER MISSISSIPPI RIVER VALLEY OF THE GREATEST PRECIPITATION...AND AT THIS TIME...LOW-END CHANCES FRIDAY NIGHT INTO SATURDAY ARE APPROPRIATE. HOWEVER...MODEL GUIDANCE CONSISTENCY DIVERGES BY SATURDAY NIGHT INTO SUNDAY. THERE ARE INDICATIONS THAT THE FRONT COULD STALL OVER OR JUST EAST OF THE FORECAST AREA...WHILE A SECONDARY PIECE OF UPPER LEVEL ENERGY ROUNDS THE BASE OF THE UPPER LEVEL TROUGH. FRONTOGENETICAL FORCING INCREASES...AND ALLOWS A DEFORMATION BAND OF RAIN TO DEVELOP SATURDAY NIGHT INTO SUNDAY AS A WEAK AREA OF LOW PRESSURE LIFTS NORTH TOWARD LAKE MICHIGAN. THE 07.12Z/08.00Z EC AND THE 08.00Z GEM SIMILARLY SHOW THIS SOLUTION...WHILE THE 08.00Z GFS PUSHES THE FRONT FURTHER EAST AND LACKS THE SECONDARY PIECE OF ENERGY...MAKING FOR A DRY FORECAST. AT THIS TIME...FAVORED THE EC / GEM SOLUTIONS...THOUGH GIVEN THE LACK OF STRONG MODEL AGREEMENT AND CONSISTENCY...ONLY INCREASED PRECIPITATION CHANCES BY ABOUT 10 PERCENT ABOVE THE CONSENSUS APPROACH. THIS YIELDED 20-40 PERCENT CHANCES ACROSS MOST OF THE AREA...HIGHEST ACROSS SOUTHWEST WISCONSIN. IF TRENDS CONTINUE TO POINT TOWARD A 08.00Z EC TYPE SOLUTION...THEN PRECIPITATION CHANCES WILL NEED TO BE RAISED SATURDAY NIGHT INTO SUNDAY MORNING. HIGH TEMPERATURES LOOK TO COOL BACK DOWN TO THE UPPER 50S TO LOWER 60S SATURDAY INTO SUNDAY...CLOSER TO NORMAL FOR THIS TIME OF YEAR. && .AVIATION...TODAY AND TONIGHT 709 AM CDT TUE OCT 8 2013 PRIMARY ISSUE FOR AVIATION TODAY IS WINDS. STRONG GRADIENT SHOULD RESULT IN GUSTS IN THE 25-30 KT RANGE...PERHAPS HIGHER AT TIMES FOR KRST. OVERALL SYNOPTIC PATTERN REMAINS INTO TONIGHT...AND ALTHOUGH WE MAY HAVE SOME PARTIAL DECOUPLING OF THE LOWER ATMOSPHERE THERE STILL SHOULD BE ENOUGH MIXING TO KEEP WINDS IN A 10-15 KT RANGE. MORE IMPORTANTLY...MODELS INDICATE THAT THE LOW LEVEL JET INCREASES TO 45-50 KTS ABOVE 2000 FT. WITH THIS RAPID CHANGE IN SPEED WITH ELEVATION MAINTAINING THE LOW LEVEL WIND SHEAR MENTION IN BOTH TAF FORECASTS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. && $$ SHORT TERM...ZT LONG TERM....ZT AVIATION...MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 AM CDT TUE OCT 8 2013 .SHORT TERM...(TODAY INTO WEDNESDAY) ISSUED AT 309 AM CDT TUE OCT 8 2013 AT 3 AM...LATEST WATER VAPOR IMAGERY AND RAP 500 MB HEIGHT ANALYSIS SHOWED A UPPER LEVEL RIDGE AXIS CENTERED ACROSS THE UPPER MIDWEST...WITH A DIGGING LONGWAVE TROUGH ENTERING THE PACIFIC NORTHWEST. AT THE SURFACE...HIGH PRESSURE OVER THE OHIO RIVER VALLEY CONTINUES TO SLIDE SOUTHEAST. THIS HAS SET THE STAGE FOR SOUTHERLY FLOW TO TAKE OVER...AS SEEN ALREADY BY VWP FROM KDMX/KFSD/KOAX/KUEX/KTWX...THE SOURCE REGION FOR TODAYS AIR MASS. A BREEZY DAY IS ON TAP AS THE PRESSURE GRADIENT TIGHTENS ACROSS MINNESOTA AND IOWA IN RESPONSE TO DEVELOPING LOW PRESSURE ACROSS THE NORTHERN PLAINS. THE STRONGEST GRADIENT EXISTS FROM CENTRAL INTO SOUTHWEST MINNESOTA...BUT MOST LOCATIONS WEST OF THE MISSISSIPPI RIVER WILL BE QUITE BREEZY TODAY. FORECAST SOUNDINGS SHOW MOSTLY SUNNY SKIES AND MIXING UP TO AROUND 850 MB...AND THIS SHOULD HELP TO MIX DOWN SUSTAINED SOUTHERLY WINDS OF 20 TO 25 MPH WITH OCCASIONAL GUSTS 30 TO 35 MPH ACROSS THE OPEN AREAS OF MINNESOTA AND IOWA. FURTHER EAST INTO WISCONSIN...LESS OF A GRADIENT BUT STILL GOOD MECHANICAL MIXING WILL RESULT IN WINDS 15 MPH WITH GUSTS TO AROUND 20 TO 25 MPH. 850 AND 925 MB TEMPERATURES ARE EXPECTED TO INCREASE 5 TO 6C COMPARED TO YESTERDAY...AND THIS SHOULD RESULT IN A 8 TO 10F BUMP IN HIGH TEMPERATURES. LOOK FOR READINGS TO TOP OUT FROM 70 TO 75F...ABOUT 5 TO 10 DEGREES ABOVE NORMAL. FOR WEDNESDAY...CONTINUED DRY AND PLEASANT AUTUMN CONDITIONS FOR THE UPPER MIDWEST. PRESSURE GRADIENT LOOSENS SOME ACROSS THE AREA...LESS MIXING SEEN IN THE SOUNDINGS AND 850 MB TEMPERATURES A FEW DEGREES COOLER SHOULD KEEP HIGHS A COUPLE DEGREES COOLER THAN TODAY. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 309 AM CDT TUE OCT 8 2013 FORECAST TARGET IN THE LONG TERM IS ON PRECIPITATION CHANCES FRIDAY INTO THE WEEKEND. BY FRIDAY...THERE IS ABOVE NORMAL MODEL AGREEMENT AND CONSISTENCY IN THE UPPER LEVEL WEATHER PATTERN. THE WESTERN CONUS TROUGH DIGS...AND EJECTS ENERGY OUT OF THE ROCKIES. HOWEVER...THE DOWNSTREAM RIDGE ACROSS THE EASTERN CONUS IS BLOCKED AND THIS FORCES THE DEVELOPING SURFACE LOW ACROSS CENTRAL PLAINS TO LIFT INTO THE NORTHERN PLAINS. BY FRIDAY NIGHT INTO SATURDAY MORNING...THE SYSTEM APPROACHES AND DRAGS A COLD FRONT ACROSS THE FORECAST AREA. HOWEVER...UPPER LEVEL DYNAMIC FORCING REMAINS TO THE NORTH AND WEST...WHILE THE BEST LOW AND MID LEVEL THERMODYNAMICS LOOK TO RESIDE SOUTH. THIS SCENARIO WOULD SPLIT THE UPPER MISSISSIPPI RIVER VALLEY OF THE GREATEST PRECIPITATION...AND AT THIS TIME...LOW-END CHANCES FRIDAY NIGHT INTO SATURDAY ARE APPROPRIATE. HOWEVER...MODEL GUIDANCE CONSISTENCY DIVERGES BY SATURDAY NIGHT INTO SUNDAY. THERE ARE INDICATIONS THAT THE FRONT COULD STALL OVER OR JUST EAST OF THE FORECAST AREA...WHILE A SECONDARY PIECE OF UPPER LEVEL ENERGY ROUNDS THE BASE OF THE UPPER LEVEL TROUGH. FRONTOGENETICAL FORCING INCREASES...AND ALLOWS A DEFORMATION BAND OF RAIN TO DEVELOP SATURDAY NIGHT INTO SUNDAY AS A WEAK AREA OF LOW PRESSURE LIFTS NORTH TOWARD LAKE MICHIGAN. THE 07.12Z/08.00Z EC AND THE 08.00Z GEM SIMILARLY SHOW THIS SOLUTION...WHILE THE 08.00Z GFS PUSHES THE FRONT FURTHER EAST AND LACKS THE SECONDARY PIECE OF ENERGY...MAKING FOR A DRY FORECAST. AT THIS TIME...FAVORED THE EC / GEM SOLUTIONS...THOUGH GIVEN THE LACK OF STRONG MODEL AGREEMENT AND CONSISTENCY...ONLY INCREASED PRECIPITATION CHANCES BY ABOUT 10 PERCENT ABOVE THE CONSENSUS APPROACH. THIS YIELDED 20-40 PERCENT CHANCES ACROSS MOST OF THE AREA...HIGHEST ACROSS SOUTHWEST WISCONSIN. IF TRENDS CONTINUE TO POINT TOWARD A 08.00Z EC TYPE SOLUTION...THEN PRECIPITATION CHANCES WILL NEED TO BE RAISED SATURDAY NIGHT INTO SUNDAY MORNING. HIGH TEMPERATURES LOOK TO COOL BACK DOWN TO THE UPPER 50S TO LOWER 60S SATURDAY INTO SUNDAY...CLOSER TO NORMAL FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1124 PM CDT MON OCT 7 2013 AREAS OF FOG/STRATUS IN THE MISSISSIPPI RIVER VALLEY OVERNIGHT/EARLY TUESDAY MORNING AND WINDS WILL BE THE MAIN CONCERN THROUGH THE PERIOD. OTHERWISE...VFR CONDITION TO PREVAIL. RIDGE OF HIGH PRESSURE OVERHEAD AND LIGHT/CALM WINDS HAVE ALLOWED TEMPERATURES TO COOL SIGNIFICANTLY LATE THIS EVENING. TEMPERATURE/DEW POINT SPREADS HAVE CLOSED WITHIN 2-5 DEGREES AT LOCATIONS WITHIN THE MISSISSIPPI RIVER VALLEY... I.E. PRAIRIE DU CHIEN/LA CROSSE/WINONA. LOOK FOR THE RIDGE TO SLIP EAST OF THE REGION OVERNIGHT WITH AN INCREASING PRESSURE GRADIENT BETWEEN THE DEPARTING RIDGE AXIS AND A TROUGH OF LOW PRESSURE MOVING ACROSS THE NORTHERN PLAINS. BELIEVE WINDS IN THE MISSISSIPPI RIVER SHOULD REMAIN LIGHT/DECOUPLED FROM INCREASING GRADIENT WIND. AREAS OF FOG/STRATUS EXPECTED TO FORM OVER THE RIVER CHANNEL AND THEN ADVECT NORTH INTO THE KLSE BETWEEN 09-13Z. BELIEVE WITH WINDS AT BLUFFTOP OUT OF THE SOUTH SOUTHWEST INCREASING TO NEAR 20KT BY 11-12Z THAT THERE MAY BE MORE OF A STRATUS ISSUE WITH OCCASIONAL LIFR CIG. KRST BOUNDARY LAYER EXPECTED TO REMAIN MIXED OVERNIGHT FOR VFR CONDITIONS. ONCE THE RIVER VALLEY FOG/STRATUS BURNS OFF BETWEEN 13-14Z...LOOK FOR BREEZY SOUTH WINDS ACROSS THE AREA WITH GOOD BOUNDARY LAYER MIXING. THE LOWER BOUNDARY LAYER IS EXPECTED TO DECOUPLE IN THE EVENING WITH LOSS OF SURFACE HEATING. MEANWHILE...WINDS ARE EXPECTED TO INCREASE ABOVE THE NOCTURNAL INVERSION INTO THE 45-50KT RANGE AROUND THE 1.5KFT LEVEL. THIS WILL HIT LOW LEVEL WIND SHEAR CRITERIA WHICH WILL BE ADDED TO BOTH KRST/KLSE TAF SITES AFTER 03Z. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...ZT LONG TERM....ZT AVIATION.....DAS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
230 AM MST THU OCT 10 2013 .SYNOPSIS... A STRONG UPPER LEVEL STORM SYSTEM WILL QUICKLY MOVE THROUGH THE AREA TODAY...RESULTING IN SCATTERED SHOWERS THIS MORNING AND SUBSTANTIALLY COOLER THAN NORMAL TEMPERATURES BY THIS AFTERNOON. DRY CONDITIONS WITH A SLOW WARMING TREND IS EXPECTED TO BEGIN ON FRIDAY...THEN CONTINUE INTO EARLY NEXT WEEK. && .DISCUSSION... UPPER LEVEL LOW PRESSURE CONTINUES TO MOVE THROUGH THE AREA THIS MORNING. REGIONAL RADAR MOSAIC INDICATES SHOWERS DEVELOPING ACROSS THE PHOENIX AREA...HOWEVER THE BACK EDGE OF THE BROKEN BAND OF RAINFALL IS ALREADY EXITING SOUTHEAST CALIFORNIA. BASED ON CURRENT TRENDS...I WOULD EXPECT PRECIP TO BEGIN CLEARING OUT OF THE PHOENIX AREA BY MID MORNING /15Z OR SO/...WITH CLEARING SKIES AND DRY CONDITIONS ACROSS THE ENTIRE FORECAST AREA BY MID AFTERNOON. THIS THINKING IS IN LINE WITH PREVIOUS FORECASTS AND CONFIRMED BY THIS MORNINGS 00Z MODEL DATA...AS WELL AS THE LATEST HRRR AND HI-RES SUITE OF WRF MODELS. INHERITED FORECAST WAS ONLY MODIFIED SLIGHTLY TO INCREASE POPS ACROSS THE PHOENIX AREA TO AROUND 40 PERCENT AND TO AROUND 90 PERCENT IN THE MOUNTAINS EAST OF THE METRO. RAINFALL TOTALS HAVE BEEN VERY LIGHT SO FAR...ONLY A FEW HUNDREDTHS OBSERVED ACROSS SOUTHEAST CALIFORNIA AND ONLY A TRACE AT YUMA. HAD THESE VALUES BEEN HIGHER I WOULD CONTEMPLATE MUCH HIGHER POPS ACROSS THE METRO BUT THIS IS SHAPING UP TO BE A WIDESPREAD BUT SHORT LIVED SPOTTY LIGHT RAIN EVENT. AS HAS ALSO BEEN ADVERTISED...THE MOST NOTEWORTHY EFFECT WILL BE SUBSTANTIALLY COOLER TEMPERATURES THIS AFTERNOON. MOST DESERT LOCALES WILL ONLY TOP OUT IN THE LOWER 70S THIS AFTERNOON...ABOUT 15-20 DEGREES BELOW NORMAL FOR OCT 10. THE FORECAST TURNS VERY TRANQUIL ACROSS THE LOWER DESERTS FROM FRIDAY ONWARD AS BROAD NORTHWESTERLY FLOW ESTABLISHES ITSELF ACROSS THE AREA. THIS WILL RESULT IN DRY WEATHER WITH A GRADUAL WARMING TREND THROUGH NEXT WEEK. THE EUROPEAN AND GFS...ALONG WITH THEIR RESPECTIVE ENSEMBLES...INDICATE A LOW MOVING THROUGH NORTHERN ARIZONA LATE THIS WEEKEND WITH A SECONDARY SHORTWAVE TROUGH SWEEPING THROUGH EARLY NEXT WEEK. AT THIS POINT IT WOULD APPEAR ANY IMPACTS THIS FAR SOUTH SHOULD BE MINIMAL/NEGLIGIBLE FOR A COUPLE OF REASONS. THE PROLONGED OVER-LAND TRAJECTORY OF THE LOW WILL RESULT IN EXTREMELY LOW PWATS /ONLY 0.5-0.6 INCHES/ AS THE TROUGH MOVES THROUGH THIS WEEKEND AS WELL AS WITH THE SECONDARY SHORTWAVE. SECOND...THE BEST ISENTROPIC LIFT IS DISPLACED WELL TO THE NORTH OF THE AREA...MORE INTO THE FOUR CORNERS AREA THAN SOUTH-CENTRAL ARIZONA. PERHAPS A SUBTLE INCREASE IN WINDS WITH THE TROUGHS BUT NOTHING OF ANY SIGNIFICANCE. AS MENTIONED BEFORE...TEMPS WILL GRADUALLY RETURN TO NORMAL BY MID WEEK. HIGHS IN THE UPPER 80S WILL BE COMMON ACROSS THE DESERTS ALONG WITH LOWS IN THE LOWER 60S. && .AVIATION... SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL... VIGOROUS AREA OF LOW PRESSURE NOW MOVING INTO SOUTHERN CALIFORNIA TONIGHT AND WILL CONTINUE TO TREK EASTWARD INTO THURSDAY. SURFACE FRONTAL PASSAGE EXPECTED TO INTERACT WITH A SOMEWHAT LIMITED MOISTURE PROFILE...ALLOWING FOR SCATTERED LIGHT SHOWER DEVELOPMENT POSSIBLE BY EARLY THURSDAY MORNING ACROSS CENTRAL ARIZONA. ALONG WITH SHOWER ACTIVITY /VCSH TO SHRA AT MOST IN THE 06Z TAFS/...STRATOCU DECKS AON 5KFT WILL BE POSSIBLE ACROSS PORTIONS OF CENTRAL ARIZONA...INCLUDING THE PHOENIX AREA...THROUGH THE EARLY MORNING HOURS. WINDS WILL REMAIN WESTERLY IN NATURE NEAR 10 TO 15KTS WITH ISOLATED GUSTS OF 20KTS THROUGH EARLY MORNING. CONDITIONS WILL GRADUALLY DRY...SKIES WILL SLOWLY CLEAR AND WINDS WILL BEGIN TO RETREAT FROM ELEVATED OBSERVATIONS THROUGH THE DAY THURSDAY. SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH... CONTINUED ELEVATED WINDS...LIGHT SHOWER ACTIVITY AND MID LEVEL CIGS ARE EXPECTED ACROSS SOUTHEAST CALIFORNIA TONIGHT. LARGE AREA OF LOW PRESSURE MOVING THROUGH THE REGION WILL SUPPORT CONTINUED BREEZY CONDITIONS...WITH GUSTS NEAR 20KTS POSSIBLE OVERNIGHT. LIGHT SHOWER ACTIVITY WILL CLEAR EAST OF THE TERMINALS BY THURSDAY MORNING...WITH GRADUALLY CLEARING SKIES AND LIGHT VARIABLE WINDS EXPECTED THURSDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... CYCLONIC FLOW WILL PREDOMINATE ACROSS THE INTERMOUNTAIN WEST...RESULTING IN A PERSISTENT WESTERLY FLOW ALONG WITH A DRYING TREND ACROSS THE REGION. TEMPERATURES WILL WARM THROUGH THE WEEKEND BEFORE LEVELING OFF NEXT WEEK TO NEAR OR SLIGHTLY BELOW NORMAL READINGS. THERE IS THE POTENTIAL FOR ANOTHER PERIOD OF GUSTY WINDS PARTICULARLY DOWN THE CO RIVER VALLEY NEXT WEDNESDAY AS ANOTHER LOW PRESSURE SYSTEM AFFECTS THE REGION. HOWEVER...UNCERTAINTY IS HIGH WITH THIS SYSTEM AND THE OFFICIAL FORECAST REFLECTS WINDS CLOSER TO CLIMATOLOGICAL NORMS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...LEINS AVIATION....NOLTE FIRE WEATHER...HIRSCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
259 AM MDT THU OCT 10 2013 .SHORT TERM...RATHER STG SYSTEM OVER SRN CALIFORNIA EARLY THIS MORNING WILL MOVE RAPIDLY ENE INTO WRN COLORADO BY THIS AFTN AND THEN INTO NERN CO OVERNIGHT. MOISTURE WILL CONTIMNUE TO INCREASE IN THE MTNS WITH PCPN BECOMING MORE WIDESPREAD LATER THIS AFTN AS LAPSE RATES STEEPEN AND HEALTHY SHOT OF QG ASCENT MOVE INTO AREA. MTN TOP WINDS WILL BE SSW WHICH IS NOT GREAT FOR OROGRAPHICS WHICH WILL LIMIT SNOW AMOUNTS INITIALLY. EAST OF THE MTNS A SFC LOW WILL INTENSIFY NEAR DENVER THIS AFTN WITH GUSTY SSW WINDS DEVELOPING SOUTH OF A DENVER TO AKRON LINE. COULD SEE SOME GUSTS IN THE 40-50 MPH RANGE OVER THE PALMER DIVIDE TOWARDS LIMON. FOR NOW WILL NOT ISSUE A HIGH WIND WARNING OVER DOUGLAS...ELBERT AND LINCOLN COUNTIES BUT SPEEDS MAY GET CLOSE TO WARNING CRITERIA FOR A FEW HOURS BETWEEN 20Z AND 00Z. AS FOR TSTM CHANCES CAPES BY LATE AFTN WILL RANGE FM 500-1000 J/KG OVER THE NERN PLAINS. A SFC CONVRGENCE ZONE MAY DVLP FM NERN WELD ACROSS MORGAN INTO WASHINGTON COUNTIES SO THIS WILL BE AN AREA TO WATCH FOR CONVECTIVE DEVELOPMENT. SOUNDINGS SHOW SOME DECENT SSHEAR BY LATE AFTN INTO THE EARLY EVENING HOURS SO THERE COULD BE A FEW STORMS WITH DAMAGING WINDS AND MARGINAL LARGE HAIL. AS FOR HIGHS THIS AFTN READINGS COULD VARY QUITE A BIT OVER NERN CO DUE TO HIGH LEVEL CLOUD COVER AND WEAK UPSLOPE BEHIND SFC LOW. FOR NOW WILL KEEP READINGS IN THE LOWER TO MID 60S CLOSER TO THE FOOTHILLS AND HAVE HIGHS IN THE LOWER TO MID 70S FURTHER EAST OVER THE PLAINS. FOR TONIGHT AN UPPER LEVEL LOW WILL BE OVER NERN CO/WRN NE AND WILL MOVE NE INTO NRN NEBRASKA BY 12Z FRI. AS THIS FEATURE MOVES ACROSS THIS EVENING WOULD EXPECT A GOOD CHC OF SHOWERS AND STORMS OVER THE FAR NERN PLAINS DURING THE EVENING HOURS WITH ACTIVITY DECREASING AFTER MIDNIGHT. IN THE MTNS OROGRAPHICS WILL BECOMEE MORE FAVORABLE AS WINDS BECOME WNW WITH CROSS-SECTIONS SHOWIGN DECENT MOISTURE IN THE 700-500 MB LAYER. THUS SHOULD SEE SNOW SHOWERS CONTINUE OVERNIGHT WITH ADVISORY AMOUNTS THRU FRI MORNING. IN ADDITION GUSTY WINDS WILL ALSO OCCUR WITH AREAS OF BLOWING SNOW OVER THE HIGHER PASSES. MEANWHILE IN AND NR THE FOOTHILLS A RATHER STG LOW LVL GRADIENT WILL EXIST WITH RATHER STG SUBSIDENCE DEVELOPING IN THE 06Z-12Z TIMEFRAME. CROSS-SECTIONS SHOW COMPONENT ALONG WINDS INCREASING TO 60-65 KTS OVERNIGHT SO THERE WILL BE A THREAT OF HIGH WINDS IN THE NORMALLY WINDY AREAS IN AND NR THE FOOTHILLS. THUS WILL ISSUE A HIGH WIND WATCH FM 06Z TONIGHT THRU 15Z ON FRI. .LONG TERM...THE UPPER LEVEL TROUGH WILL CLOSE OFF AND INTENSIFY OVER THE DAKOTAS ON FRIDAY AS IT LIFTS NORTHEAST. COLORADO WILL BE UNDER A WEST-NORTHWEST FLOW ALOFT FRIDAY. STRONG DOWNSLOPE WINDS BEHIND THIS SYSTEM WILL DECREASE FRIDAY MORNING AS THE TROUGH EXITS THE AREA. THE FLOW ALOFT WILL REMAIN STRONG AND MOIST ENOUGH FOR OROGRAPHIC SNOW OVER THE MOUNTAINS. SNOW WILL LIKELY INCREASE IN COVERAGE AND INTENSITY FRIDAY AFTERNOON AS A SHORT WAVE TROUGH MOVES OVER THE REGION. MAY BE ENOUGH LIFT WITH THIS SYSTEM TO PRODUCE RAIN SHOWERS OVER THE PLAINS...MAINLY FRIDAY AFTERNOON AND EVENING. ONCE THIS FEATURE EXITS THE AREA...DRY AND MILD CONDITIONS WILL PREVAIL SATURDAY AS A WEAK RIDGE MOVES ACROSS THE STATE. MODELS STAY IN GOOD AGREEMENT THROUGH SUNDAY. THEY ARE SHOWING THE NEXT TROUGH BOTTOMING OUT OVER NEVADA AND UTAH. THIS WILL PRODUCE A SOUTHWEST FLOW ALOFT. BY AFTERNOON THERE MAY BE ENOUGH MOISTURE EMBEDDED IN THE FLOW ALOFT TO PRODUCE A FEW MOUNTAIN SHOWERS. TEMPERATURES WILL BE MILD WITH HIGHS IN THE 60S OVER NORTHEAST COLORADO. FOR MONDAY THROUGH WEDNESDAY...MODELS ARE SHOWING VARIOUS SOLUTIONS WHICH LEADS TO A LOW CONFIDENT FORECAST. GENERAL PATTERN IS THAT A LARGE TROUGH WILL FORM OVER NORTHERN ROCKIES. THE MODELS SHOW A FEW SHORT WAVE TROUGHS ROTATING AROUND THE LOW. HOWEVER...THE GFS IS PROGRESSIVE WITH THE TROUGH AND HAS IT CENTERED OVER THE GREAT LAKES WEDNESDAY AFTERNOON. THE ECMWF HAS IT OVER THE NORTHERN ROCKIES THROUGH WEDNESDAY. WOULD EXPECT A PERIOD OR TWO OF BRIEF LIGHT PRECIPITATION OUT OF THIS PATTERN. THE TROUGH DOES NOT DIG FAR ENOUGH SOUTH TO PRODUCE A SIGNIFICANT STORM FOR COLORADO. WILL BROAD BRUSH 5-20 POPS FOR EARLY NEXT WEEK. TEMPERATURES ARE EXPECTED TO BE AT OR BELOW NORMAL UNDER THIS TYPE OF PATTERN && .AVIATION...THRU MID AFTN WILL TREND TOWARDS THE HRRR FOR SFC WINDS WHICH ARE GOING TO BE A NIGHTMARE TO FCST. AT THIS TIME LOOKS LIKE INITIAL SFC LOW WILL HANG AROUND THE AIRPORT THRU 18Z WITH WINDS BECOMING SSE ON THE EAST SIDE WHILE ON THE WEST SIDE WINDS WIL BE MORE NNW. BY 20Z THE HRR LIFTS THE LOW INTO SCNTRL WELD COUNTY WITH WINDS SHIFTING TO THE SSW WITH SPEEDS IN THE 20-25 MPH RANGE WITH SOME GUSTS FM 35-40 MPH. MEANWHILE COULD SEE SOME WDLY SCT HIGH BASED STORMS DVLP IN THE 20Z-00Z TIME FRAME ALTHOUGH THE HRRR KEEEPS MOST OF THIS ACTIVITY NORTH OF DIA. AS FOR CLOUODS EARLY THI MORNING THERE ARE SOME CEILINGS IN THE 3500-4000 FT RANGE FM BJC TO LONGMONT HOWEVER DUE TO HI LVL CLOUDS DO NOT KNOW HOW FAR EAST THESE CLOUDS ARE. FOR NOW WILL CONTINUE WITH A TEMPO GROUP FOR CEILINGS IN THE 4000 FT RANGE THRU 14Z. IF SFC LOW STAY WEST OF DIA THEN THESE LOWER CEILINGS MAY NOT AFFECT THE AIRPORT. FOR TONIGHT GUSTY SSW WINDS SHOULD BECOME MORE WLY BY 02Z WITH SOME GUSTS TO 25 MPH THRU 06Z POSSIBLE. IN FACT THESE GUSTY WINDS COULD CONTINUE THRU FRI MORNING IF STRONGER WINDS NR THE FOOTHILLS MIX DOWN TO THE SFC. && .HYDROLOGY...NO ISSUES. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR COZ035-036-038-039. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON MDT FRIDAY FOR COZ031-033-034. && $$ SHORT TERM...RPK LONG TERM....MEIER AVIATION...RPK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
323 AM CDT THU OCT 10 2013 .DISCUSSION... 322 AM CDT TODAY THROUGH TONIGHT... SIMILAR STORY FOR TODAY...ABUNDANT SUNSHINE AND UNSEASONABLE WARMTH ACROSS THE REGION. BROAD ANTI-CYCLONIC FLOW REMAINS ANCHORED ACROSS THE EASTERN THIRD OF THE CONUS...WITH A WAVE LIFTING NORTHEAST OFF OF THE VIRGINIA COAST. NEAR CLOUDLESS SKIES WITH LIGHT TO CALM WINDS EARLY THIS MORNING ACROSS THE FORECAST AREA. VWP FROM WSR-88D KLOT INDICATE WINDS REMAIN RATHER UNIFORM FROM THE EAST AT 1-9KFT AGL. LOCATIONS ADJACENT TO LAKE MICHIGAN IN FAR NORTHEAST IL CONTINUE TO SEE TEMPS HOLDING IN THE LOW 50S...WHILE FURTHER SOUTH IN THE METRO CHICAGO AREA TEMPS HOVER IN THE MID 50S. ELSEWHERE TEMPS HAVE RADIATED INTO THE LOW/MID 40S...WITH T/TD SPREADS NEARING 2 DEG OR LESS. THE COMBINATION OF MINIMAL T/TD SPREADS AND CALM WINDS HAS ALLOWED PATCHY FOG TO DEVELOP AGAIN THIS MORNING. EXPECT A FEW LOW LYING AREAS TO SEE VSBYS REDUCED TO ARND 1SM...HOWEVER SHOULD ONLY LINGER UNTIL JUST AFTER DAYBREAK. SHORTLY AFT SUNRISE THE SFC SHUD QUICKLY WARM GIVEN THE PAST SEVERAL DAYS OF DRY CONDS. THIS HAS RESULTED IN REDUCED HEAT CAPACITY...AND ATMOSPHERIC PARCELS WILL RESPOND TO THE SOLAR RADIATION IN THE FORM OF A LARGE DIURNAL SWING IN TEMPS TODAY. PLUMES SUGGEST TEMPS WILL BE IN THE MID/UPR 70S FOR MUCH OF THE CWFA...WITH THE EXCEPTION OF AREAS ADJACENT TO LAKE MICHIGAN. AN AFTN LAKE BREEZE IS EXPECTED TO DEVELOP AND PUSH INLAND...WHICH WILL LIKELY CAP TEMPS DOWNTOWN CHICAGO IN THE UPR 60S. TONIGHT DRY WEATHER CONTINUES WITH NEAR CLOUDLESS SKIES YET AGAIN...A FEW CIRRUS CLOUDS MAY SLIDE OVERHEAD WHICH MAY SLOW THE RATE OF COOLING TONIGHT. THUS IT APPEARS TEMPS WILL LIKELY BE SLIGHTLY WARMER IN THE LOW 50S...WITH A FEW TRADITIONAL LOCATIONS RADIATING INTO THE UPR 40S. CONFIDENCE...HIGH. FRIDAY THROUGH SATURDAY... MID-LVL RIDGING CONTINUES TO HANG TOUGH THROUGH MUCH OF FRI...AS THE STRENGTH OF THE 500MB RIDGE OVER QUEBEC/EASTERN ONTARIO REMAINS PROGGED AT 3 SIGMA. GIVEN THE STRENGTH OF THE DOWNSTREAM RIDGE THROUGH FRI NGT...IT APPEARS TO BE HAVING A SIGNIFICANT DIMINISHING ROLE IN THE APPROACHING MID-LVL SHORTWAVE THAT WILL LIFT NORTHEAST FROM THE FOUR-CORNERS REGION. OPERATIONAL GUIDANCE HAS CONTINUED TO TREND DRIER WITH THIS SYSTEM...WITH THE EARLIEST PRECIP NOT ARRIVING UNTIL ARND DAYBREAK SAT. LCL WRF MODEL THRU 12Z SAT INDICATES DRY WEATHER WITH THE FRONTAL BOUNDARY MUCH FASTER AND NEARING FAR NORTHWEST IL ARND DAYBREAK SAT. EC/GFS BOTH HAVE TRENDED DRIER WITH THE EARLY WEEKEND SYSTEM...WITH THE BEST DYNAMICS PASSING WELL NORTHWEST OF THE FORECAST AREA SAT. IT IS CONCEIVABLE THAT SAT MAY JUST SEE SPOTTY SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM SOUTH OF I-80...AS MUCAPE IN THE SFC-500MB LAYER HOVERS ARND 200-400J/KG. THIS TOO HAS BEEN ON A DECREASING TREND. AT THIS TIME HAVE HELD ONTO MENTION OF ISOLATED THUNDER FOR SAT THRU SAT EVE...THEN WITH THE FORWARD SPEED INCREASING FOR SAT NGT HAVE PULLED MENTION OF PRECIP AFT MIDNIGHT. FLOW THEN TURNS NORTHWEST BEHIND THE BOUNDARY...WITH COOLER/DRIER AIR FILTERING INTO THE CWFA FOR THE REMAINDER OF THE WEEKEND. TEMPS FRI AHEAD OF THE SYSTEM WILL LIKELY BE WARM AGAIN...WITH STRONG SOUTHEASTERLY TURNING SOUTHERLY FLOW. MANY PLUMES INDICATE TEMPS WILL BE IN THE MID/UPR 70S FRI...AND COULD PERHAPS SEE A HANDFUL OF POINTS REACH 80 DEGREES SOUTH OF A LASALLE TO KANKAKEE LINE. THEN WITH INCREASED CLOUD COVER FRI NGT TEMPS WILL REMAIN MILD IN THE MID/UPR 50S. DEPENDING ON THE TIMING OF FRONTAL PASSAGE SAT...AND IF CLOUD COVER CAN ERODE QUICK ENOUGH BEFORE SUNSET...TEMPS COULD STILL WARM INTO THE LOW/MID 70S. THE WARMEST LOCATIONS WILL LIKELY BE THE SOUTHEAST CWFA WHERE TEMPS MAY TOUCH 80 DEG SAT AFTN. CONFIDENCE...HIGH. SUNDAY THROUGH WEDNESDAY... ENSEMBLES HAVE CONTINUED TO PROG SLOW WEAKENING IN THE 500MB RIDGE OVER QUEBEC SUN...WITH THE TROUGH OVER THE CENTRAL CONUS FLATTENING. AN ELONGATED TROUGH APPEARS TO SETUP SUN NGT STRETCHING SOUTHWEST THROUGH THE ROCKIES...THEN RIDGING IS POISED TO DEVELOP ACROSS THE PAC-NW MON INTO TUE. THE INCREASING MID-LVL HEIGHTS ACROSS THE PAC-NW/WESTERN CANADA WILL PLAY A ROLE IN A POSSIBLE PATTERN ADJUSTMENT TOWARDS THE MIDDLE OF NEXT WEEK. OPERATIONAL GUIDANCE SLIDES SFC RIDGE INTO THE REGION SUN THRU MON...THEN QUICKLY DRIFTS NORTHEAST MON NIGHT. OPERATIONAL GUIDANCE HAS COME INTO BETTER AGREEMENT WITH A SHORTWAVE LIFTING INTO THE CENTRAL PLAINS MON NGT...WITH CONSIDERABLE MOISTURE BEING PUMPED INTO THIS FEATURE. GUIDANCE THEN BRINGS PRECIP NORTHEAST INTO THE FORECAST AREA MON NGT/TUE. SOME UNCERTAINTY REMAINS WITH RESPECT TO THE TIMING/COVERAGE OF PRECIP...HOWEVER CONCEPTUALLY THIS SYSTEM WOULD LIKELY PRODUCE A DECENT SLUG OF PRECIP TUE BEFORE A DRY SLOT PIVOTS EAST TUE NGT/WED. THE OVERALL THEME WITH TEMPS IN THE EXTENDED PERIODS IS MORE OF A SEASONAL SETUP...HOWEVER TEMPS COULD REMAIN MUCH COOLER IF ABUNDANT PRECIP DOES DEVELOP. THIS COULD HOLD TEMPS IN THE MID/UPR 50S...AT THIS POINT HAVE HELD ONTO TEMPS IN THE LOW/MID 60S. THEN TOWARDS THE MIDDLE OF NEXT WEEK WITH THE AFOREMENTIONED RIDGING ACROSS THE PAC-NW/WESTERN CANADA REMAINING IN PLACE...THIS WILL LIKELY PROVIDE COOLER AIR TO SLIDE SOUTHEAST ACROSS CENTRAL CANADA AND PUSH IN BEHIND THE EARLY WEEK SYSTEM INTO THE CWFA WED. HIGHS WED MAY STRUGGLE TO WARM BEYOND THE MID 50S. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * LIGHT/SHALLOW FOG THIS MORNING. * LAKE BREEZE THIS AFTERNOON. CMS //DISCUSSION...UPDATED 06Z... A RIDGE OF HIGH PRESSURE EXTENDS OVER THE GREAT LAKES REGION THIS MORNING AND WILL VERY SLOWLY DRIFT EAST TONIGHT AND FRIDAY. WINDS WILL REMAIN LIGHT AND VARIABLE OR CALM THROUGH SUNRISE THEN TURN SOUTHEASTERLY...WITH SPEEDS UNDER 10KTS. THIS HIGH WILL ALSO A LAKE BREEZE TO FORM WITH WINDS TURNING EASTERLY AT ORD/MDW BY MID AFTERNOON...NORTHEASTERLY AT GYY. WINDS WILL THEN SETTLE BACK TO LIGHT SOUTHEASTERLY AFTER SUNSET. PATCHES OF LIGHT/SHALLOW GROUND FOG HAVE DEVELOPED IN SOME AREAS INCLUDING AT GYY. AS TEMPS COOL TOWARD THE DEWPOINTS...EXPECT FOG TO CONTINUE TO DEVELOP IN COVERAGE AND CURRENT MVFR VIS WITH SHALLOW FOG MENTION AT RFD/DPA/GYY SEEMS REASONABLE...THOUGH SOME AREAS...PERHAPS NORTH OF THE TERMINALS INTO SOUTHERN WI...COULD BECOME MORE WIDESPREAD IFR VIS OR LOWER. POSSIBLE TO SEEM SOME 4-6SM VIS AT ORD/MDW BEFORE SUNRISE BUT CONFIDENCE IS LOW AND HAVE LEFT OUT OF THIS FORECAST. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW FOR LIGHT/SHALLOW FOG THIS MORNING. * HIGH FOR A LAKE BREEZE REACHING ORD/MDW...MEDIUM FOR TIMING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... * FRIDAY...DRY/VFR. * SATURDAY...CHANCE OF SHRA/TSRA. * SUNDAY AND MONDAY...DRY/VFR. * TUESDAY...SLIGHT CHANCE OF SHRA. KJB && .MARINE... 300 AM...A LARGE RIDGE OF HIGH PRESSURE EXTENDING FROM THE WESTERN LAKES TO NEW ENGLAND WILL SLOWLY DRIFT SOUTHEAST TONIGHT AND FRIDAY AND EVENTUALLY MERGE WITH STRONGER HIGH PRESSURE MOVING SOUTHEAST ACROSS QUEBEC FRIDAY AND FRIDAY NIGHT. THIS WILL MAINTAIN MAINLY SOUTHEASTERLY FLOW OVER THE LAKE INTO FRIDAY WITH SPEEDS GRADUALLY INCREASING INTO THE 10-20 KT RANGE FRIDAY. WEAK LOW PRESSURE NEAR COLORADO THIS MORNING WILL DEEPEN AS IT MOVES NORTH ACROSS THE DAKOTAS FRIDAY AND ACROSS MANITOBA AND WESTERN ONTARIO FRIDAY NIGHT. THIS WILL CAUSE THE GRADIENT TO TIGHTEN ACROSS THE WESTERN LAKES FRIDAY NIGHT INTO SATURDAY MORNING WITH A PERIOD OF 20-25KTS POSSIBLE. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE SATURDAY AFTERNOON OR SATURDAY EVENING SHIFTING WINDS TO THE WEST AND THEN TO THE NORTHWEST SATURDAY NIGHT INTO SUNDAY. HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE LAKES REGION SUNDAY INTO SUNDAY NIGHT. ANOTHER LOW PRESSURE IS EXPECTED TO MOVE FROM THE CENTRAL PLAINS MONDAY ACROSS THE LAKES REGION TUESDAY INTO WEDNESDAY... THOUGH CONFIDENCE REGARDING THE STRENGTH AND TRACK OF THIS SYSTEM REMAINS LOW AT THIS TIME. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion National Weather Service Lincoln IL 305 AM CDT Thu Oct 10 2013 .DISCUSSION... ISSUED 305 AM CDT Thu Oct 10 2013 SHORT TERM...Today through Saturday Gradual moisture advection from the south over the past 24 hours has resulted in 50+ surface dewpoints spreading northward into southern Illinois early this morning. Due to the increased low-level moisture and nearly calm winds beneath ridge axis, areas of fog are beginning to develop south of I-70. HRRR shows the fog developing/spreading further north toward dawn. Have therefore included patchy fog along and south of a Jacksonville to Paris line through 14z/9am. Once early morning fog dissipates, partly to mostly sunny skies and very warm conditions will prevail for the remainder of the day. Afternoon high temperatures will be a degree or two warmer than yesterday, with readings reaching the middle to upper 70s. As ridge only slowly shifts eastward, the potential exists for more patchy fog tonight. Given increasing moisture, clear skies, and continued light winds near the departing ridge axis, will include fog mention for the eastern half of the KILX CWA. Further west, light return flow should keep atmosphere mixed just enough to prevent fog west of I-55. Once fog dissipates, another mostly sunny and warm day will unfold on Friday...with highs reaching the 80-degree mark. 00z Oct 10 models have sped up the approach of the weekend system, with FROPA now expected to occur Saturday afternoon. NAM is the fastest of the models, but think it is too aggressive with pushing the front eastward into the prevailing upper ridge. Will therefore trend closer to the slightly slower ECMWF/GFS solution. With front expected to be along the Mississippi River by 12z Saturday, will maintain low chance POPs in the Illinois River Valley late Friday night, then will spread rain chances further east across the rest of the area on Saturday. With best upper support remaining well to the N/NW and only a shallow moisture profile in place, am not expecting a widespread soaking rainfall on Saturday. Will keep POPs in the chance category accordingly. Since system is moving a bit faster than previously forecast, will only hold on to chance POPs across the eastern CWA into the evening hours, then will go dry across the board overnight. LONG TERM...Sunday through Wednesday High pressure will build into the region behind the departing cold front on Sunday, with models indicating a very dry airmass with dewpoints in the lower to middle 40s settling in. Mostly clear and dry weather is expected for both Sunday and Monday, with warm afternoon highs in the upper 60s/lower 70s and cool overnight lows in the 40s. Next system is still slated to come into the picture early next week, although details are not clear at this point. An upper-level trough is expected to dig into the Rockies Sunday into Monday, although how deep the system becomes and how quickly it lifts northeastward are still very much in question. GFS is more progressive with the system, with the upper low and its associated surface wave ejecting into the western Great Lakes by Tuesday evening. Meanwhile, latest ECMWF is deeper and holds the system back in the Rockies/Plains until Thursday. Given significant timing discrepancies, have opted to leave going forecast alone until better agreement is achieved. As such, am expecting showers and thunderstorms to develop across the area Monday night into Tuesday, followed by cooler/drier weather by Wednesday. Barnes && .AVIATION... ISSUED 1125 PM CDT Wed Oct 9 2013 Main forecast concern will be with the development of fog in the 08z to 13z time frame, with VFR conditions expected for the remainder of the forecast period. Persistent S-SE flow has gradually drawn moisture northward into parts of south central IL late this evening with sfc dew points in the 50s along the I-70 corridor. Temp-dew point spreads already down to between 3-5 degrees in parts of our area so with a light wind and clear sky, it appears that a few locations in our taf area will see MVFR vsbys late tonight. What fog we do see should dissipate by 15z with the next concern being with sct-bkn cu forming by 18z. Forecast soundings suggest cig bases around 4000 feet during the afternoon with the better probabilities for bkn cigs at SPI and DEC. Light and variable winds today will turn more into a southerly direction around 10 kts on Thursday, and then back into a light southeast flow Thursday night with speeds around 5 kts. Smith && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1250 PM CDT TUE OCT 8 2013 .DISCUSSION... 307 AM CDT TODAY THROUGH TONIGHT... FORECAST CHALLENGES IN THE NEAR TERM ARE MAX TEMPS AND OVERNIGHT LOWS. BROAD RIDGE OF HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER FOR MUCH OF THE GREAT LAKES AND OHIO VALLEY REGIONS. THE CENTER OF ANTI-CYCLONIC FLOW HAS PUSHED SOUTHEAST OF THE FORECAST AREA INTO CENTRAL INDIANA/OHIO. THIS HAS ALLOWED WINDS EARLY THIS MORNING IN A FEW LOCATIONS TO HAVE TURNED SOUTHERLY. ALTHOUGH ENOUGH INFLUENCE FROM THE HIGH PRESSURE REMAINS AND HAS MANY SITES NORTH OF THE I-80 CORRIDOR IN NORTHERN IL HAVING GONE CALM. TEMPERATURES EARLY THIS MORNING HAVE RADIATED INTO THE MID 40S. A LIMITING FACTOR FOR SEEING ACROSS THE BOARD TEMPS MUCH COOLER HAS BEEN THE WINDS ALOFT HOVERING AT 20KT ARND 2KFT AGL...SHOWN BY THE VWP FROM THE WSR-88D KLOT. THIS HAS CREATED JUST ENOUGH FRICTION WITHIN THE BOUNDARY LAYER TO PREVENT TEMPS FROM COMPLETELY RADIATING. ALTHOUGH A FEW TRADITIONAL SPOTS HAVE BEEN ABLE TO COOL INTO THE LOW 40S. IN ADDITIONALLY SHALLOW GROUND FOG WAS BEGINNING TO FORM...HOWEVER THIS WILL LIKELY BE PATCHY AS A WORST CASE SCENARIO THIS MORNING GIVEN THE AFOREMENTIONED WINDS JUST ABOVE THE SFC. WHERE THE FOG FORMS EXPECT TEMPS TO RADIATE FURTHER INTO TO ARND 40 DEGREES BY DAYBREAK. THEN THE SHALLOW FOG SHOULD QUICKLY LIFT BY 14Z. ABUNDANT SUNSHINE COUPLED WITH SOUTHERLY WINDS ARND 10KT WILL ALLOW SFC TEMPS TO STEADILY WARM ABOVE CLIMO TODAY. MANY PLUMES INDICATE TEMPS WILL LIKELY WARM INTO THE LOW TO POSSIBLY MID 70S THIS AFTN...WITH THE WARMEST TEMPS FALLING ALONG SOUTH OF A ROCKFORD TO KANKAKEE LINE. DESPITE THE SOUTHERLY FLOW...THE WARM SFC TEMPS WILL LIKELY AID IN DEVELOPING A LAKE BREEZE TODAY. EXPECT THE LAKE BREEZE TO BE MORE OF AN IMPACT TO NORTHEAST IL RATHER THAN NORTHWEST IN AS THE SOUTHERLY FLOW SHOULD PREVENT MUCH MOVEMENT ONSHORE FOR NORTHWEST IN. THUS AREAS ADJACENT TO LAKE MI WILL LIKELY SEE TEMPS EARLY THIS AFTN COOL INTO THE MID 60S BEHIND THE BREEZE. AFTERNOON MIXING WILL HOLD DEW PTS IN THE MID 40S...WITH MIN RELATIVE HUMIDITY FALLING INTO TO 35 TO 40 PERCENT ACROSS MUCH OF THE FORECAST AREA. SKIES REMAIN MOSTLY CLEAR TONIGHT WITH WINDS REMAINING SOUTHERLY LESS THAN 10KTS...WITH OVERNIGHT LOWS STEADILY COOLING INTO THE LOW/MID 40S. URBAN HEAT ISLAND WILL KEEP THE CHICAGO METRO AREA IN THE LOW/MID 50S. CONFIDENCE...HIGH. WEDNESDAY THROUGH FRIDAY... MUCH OF THE MEDIUM TERM WILL BE DOMINATED BY A BROAD 500MB RIDGE POSITIONED OVER THE EASTERN GREAT LAKES/QUEBEC. ENSEMBLES HAVE CONTINUED TO TREND STRONGER WITH THIS FEATURE...WHICH IS LIKELY A REFLECTION OF THE DIGGING/STRENGTHENING TROUGH ACROSS THE SOUTHWEST CONUS. TOWARDS THE THUR/FRI TIMEFRAME THE TROUGH AXIS BEGINS TO WEAKEN AND PIVOT EAST...WHICH BEGINS TO SIGNAL THAT THE DOWNSTREAM RIDGE WILL LIKELY BEGIN TO WEAKEN AND DRIFT EAST. SFC FEATURES SUPPORT THIS WITH ANTI-CYCLONIC FLOW BEGINNING TO LOOSEN ITS INFLUENCE BY FRI...AS LLVL MOISTURE BEGINS TO STREAM NORTH FROM THE OZARKS INTO THE WESTERN GREAT LAKES REGION. OPERATIONAL SOLUTIONS CONTINUE TO PROG A VORT SPEED MAX ROUNDING THE TROUGH AXIS AND LIFTING NORTH INTO THE HIGH PLAINS FRI...WITH A CHANNEL OF MOISTURE ORIENTED FROM THE NORTHERN PLAINS SOUTH THROUGH TEXAS FRI AFTN. AS THE UPSTREAM TROUGH DRIFTS EAST FRI NIGHT...IT SHOULD BRING THE EARLIEST CHANCES FOR SHOWERS/THUNDERSTORMS TO THE WESTERN CWFA. HOWEVER MID-LVL HEIGHTS REMAIN ELEVATED...WHICH COULD SIGNAL KEEPING FRI NIGHT DRY ACROSS THE ENTIRE CWFA. TEMP PLUMES FOR WED/THUR/FRI ALL SIGNAL ABOVE CLIMO TEMPS...MAINLY IN THE MID 70S. ALTHOUGH COULD SEE TEMPS FRI WARMING INTO THE UPR 70S AS SOUTHERLY FLOW BEGINS TO STRENGTHEN AHEAD OF THE MID-LVL TROUGH. CONFIDENCE...HIGH. SATURDAY THROUGH MONDAY... THE EXTENDED PERIODS CONTINUE TO BE DOMINATED BY A MID-LVL RIDGE PARKED ACROSS EASTERN ONTARIO/QUEBEC...WHICH WILL PLAY A PIVOTAL ROLE IN THE TIMING OF THE UPCOMING WEEKEND SYSTEM. GUIDANCE THROUGH THE END OF THE WEEK WAS INDICATING THE MID-LVL RIDGE WOULD WEAKEN...HOWEVER LATEST ENSEMBLES ARE BEGINNING TO SUGGEST SOME RE-STRENGTHENING MAY TAKE PLACE FOR THE UPCOMING WEEKEND. TEMPS AHEAD OF THE SYSTEM FOR SAT WILL QUICKLY WARM INTO THE MID/UPR 70S UNDER SOUTHERLY FLOW. IF THIS SCENARIO VERIFIES A SLOWER EVOLUTION/ARRIVAL TO THE 500MB SHORTWAVE AND PRECIP CHANCES WILL TAKE PLACE...PUSHING PRECIP INTO SAT NIGHT/SUN. THE CHANNEL OF MOISTURE SHOULD PUSH EAST OF THE AREA SUN AFTN/MON WITH SFC HIGH PRESSURE BUILDING BACK INTO THE REGION...WITH TEMPS COOLING BACK INTO THE 60S. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * POSSIBLE LAKE BREEZE THIS AFTERNOON WHICH WOULD SHIFT WIND DIRECTLY FROM SLY TO SELY OR ELY. KREIN //DISCUSSION...UPDATED 18Z... A LARGE AREA OF HIGH PRESSURE OVER THE EXTENDS FROM THE EASTERN GREAT LAKES THROUGH THE MIDDLE MISSISSIPPI VALLEY. COMBINED WITH UPPER LEVEL RIDGING...SKIES WILL REMAIN CLEAR...WITH THE ONLY CLOUD COVER LIKELY TO BE SOME SCT CI. WINDS WILL BE THE ONLY CONCERN FOR THE REMAINDER OF THE AFTERNOON. WITH A WEAK PRESSURE GRADIENT OVER NERN IL/NRN IN...AND A TROUGH OF LOW PRESSURE DEVELOPING OVER THE PLAINS...WINDS SHOULD REMAIN GENERALLY SOUTHERLY TO JUST EAST OF SOUTH THROUGH THE PERIOD. DIFFERENTIAL HEATING BETWEEN LAND AND LAKE MICHIGAN AND THE RELATIVELY WEAK PRESSURE GRADIENT MAY LEAD TO LAKE BREEZE DEVELOPMENT...TURNING WINDS NEAR THE LAKE TO SELY OR ESELY...BUT WINDS THROUGH THE BOUNDARY LAYER SHOULD BE STRONG ENOUGH TO KEEP THE LAKE BREEZE FROM REACHING ORD/MDW...LET ALONE ANY OF THE OTHER TERMINALS...SO EXPECT THAT PREVAILING WINDS THIS AFTERNOON SHOULD BE JUST EAST OF SOUTH. THE ONLY OTHER POTENTIAL CONCERN WOULD BE FOR SOME PATCHY GROUND FOG TO DEVELOP IN SOME ISOLATED...LOW LYING AREAS. DO NOT EXPECT WIDESPREAD VSBY RESTRICTIONS...THOUGH THERE WOULD BE A SMALL CHANCE FOR SOME GROUND FOG TO IMPACT DPA. KREIN //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM CONFIDENCE IN LAKE BREEZE FORMATION...LOW CONFIDENCE THAT IT WILL REACH ORD/MDW. * MEDIUM TO HIGH CONFIDENCE THAT THERE WILL BE NO VISBY RESTRICTIONS FROM SHALLOW GROUND FOG AT ORD/MDW TONIGHT. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...DRY/VFR. * THURSDAY AND FRIDAY...DRY/VFR. AFTERNOON LAKE BREEZE POSSIBLE EACH DAY. * SATURDAY...CHANCE OF SHRA/TSRA. * SUNDAY...CHANCE SHRA. * MONDAY...DRY/VFR. && .MARINE... 315 AM...HIGH PRESSURE OVER THE OHIO VALLEY WILL STRENGTHEN AS IT MOVES NORTHEAST TO NEW ENGLAND TODAY AND TONIGHT. THIS HIGH WILL SLOWLY DRIFT EAST OVER THE ATLANTIC WHILE A WEAKER RIDGE EXTENDS BACK WEST INTO THE LAKES REGION INTO THURSDAY. MEANWHILE...LOW PRESSURE OVER CENTRAL CANADA WILL MOVE EAST TO ONTARIO WEDNESDAY AS IT SLOWLY WEAKENS. THE GRADIENT BETWEEN THIS APPROACHING LOW AND THE STRENGTHENING HIGH TO THE EAST WILL STEADILY TIGHTEN TODAY INTO TONIGHT PRODUCING INCREASING SOUTHERLY WINDS. SPEEDS LIKELY TO INCREASE UP TO 30 KTS OVER THE NORTH HALF LATER THIS AFTERNOON AND CONTINUE INTO WEDNESDAY MORNING BEFORE THE GRADIENT WEAKENS WEDNESDAY. ANOTHER LOW PRESSURE IS EXPECTED TO MOVE NORTHEAST OVER THE PLAINS THURSDAY NIGHT AND FRIDAY REACHING SOUTHERN MANITOBA FRIDAY NIGHT. THIS CURRENT TRACK WOULD SUGGEST THE STRONGEST WINDS WILL REMAIN WEST OF LAKE MICHIGAN WITH SOUTHERLY WINDS PERHAPS INTO THE 15-25KT RANGE FRIDAY NIGHT AND SATURDAY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1206 PM CDT Tue Oct 8 2013 .DISCUSSION... ISSUED 935 AM CDT Tue Oct 8 2013 High pressure near the Ohio/Pennsylvania border ridges southwest all the way to southeast Oklahoma, and will keep our weather quiet today. Dry air aloft should lead to mainly clear skies through the day, although the RAP and NAM do hint at a bit of diurnal cumulus south of a St Louis to Champaign line for a few hours. Have sent some zone/grid updates mainly to remove the earlier fog mention and update the dew point grids. Also did some minor hourly temperature updates, but overall highs still look reasonable. Geelhart && .AVIATION... ISSUED 1205 PM CDT Tue Oct 8 2013 Few clouds expected the next 24 hours, although NAM/RAP models continue to hint at a bit of diurnal development around 4000 feet this afternoon near KCMI/KDEC southward. Southerly winds will gradually trend more toward the southeast overnight. Geelhart && .PREV DISCUSSION... ISSUED 136 AM CDT Tue Oct 8 2013 SHORT TERM...Today through Thursday Ridge of high pressure currently centered over the Ohio River Valley will dominate the weather across central Illinois over the next several days. With calm winds beneath the ridge axis and 06z/1am temp/dewpoint spreads of only 1 to 2 degrees, think shallow ground fog will develop across the E/SE KILX CWA over the next couple of hours. HRRR suggests this as well, with fog generally forming along and southeast of a Danville to Shelbyville line. Will include patchy fog across this area early this morning accordingly. Once fog dissipates, sunny skies can be expected across the board for the remainder of the day. Full sunshine working on dry airmass will boost temperatures several degrees warmer than yesterday, with afternoon highs topping out in the middle to upper 70s. Surface ridge axis will begin to shift northward on Wednesday, allowing light southerly winds to back to a more east-southeast direction. This will temporarily curtail the warming trend, with highs perhaps a degree or two cooler than today in the middle 70s. With high pressure centered over the Great Lakes, both the NAM and GFS suggest some moisture associated with persistent upper low over the SE CONUS may advect northwestward around the periphery of the high into central Illinois on Thursday. Forecast soundings remain dry and forcing is completely absent, so only noticeable change in the weather will be a few more clouds. Under partly to mostly sunny skies, highs will once again reach the middle to upper 70s. LONG TERM...Friday through Monday Warmest day of the forecast period will be Friday, when southerly winds allow highs to approach the 80-degree mark. Meanwhile, closed upper low over the Desert Southwest will begin lifting northeastward into the Northern Plains/Upper Midwest, dragging a cold front into Illinois over the weekend. Latest run of the GFS continues to be rather progressive with the approaching front, bringing scattered showers and thunderstorms into the area Saturday/Saturday night, then quickly departing on Sunday. 12z ECMWF remains slower, with precip holding off until Saturday night into Sunday. Given developing blocking pattern due to upper low meandering northward into the Mid-Atlantic states later this week, would tend to side with the slower ECMWF solution. As a result, will keep chance POPs confined to the western half of the KILX CWA during the day Saturday, with rain chances spreading across the entire area Saturday night. Will hold on to chance POPs in the east on Sunday as well, as front will be slow to depart. After that, a return to dry weather with seasonable temps in the upper 60s and lower 70s can be expected by Monday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1050 AM CDT TUE OCT 8 2013 .DISCUSSION... 307 AM CDT TODAY THROUGH TONIGHT... FORECAST CHALLENGES IN THE NEAR TERM ARE MAX TEMPS AND OVERNIGHT LOWS. BROAD RIDGE OF HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER FOR MUCH OF THE GREAT LAKES AND OHIO VALLEY REGIONS. THE CENTER OF ANTI-CYCLONIC FLOW HAS PUSHED SOUTHEAST OF THE FORECAST AREA INTO CENTRAL INDIANA/OHIO. THIS HAS ALLOWED WINDS EARLY THIS MORNING IN A FEW LOCATIONS TO HAVE TURNED SOUTHERLY. ALTHOUGH ENOUGH INFLUENCE FROM THE HIGH PRESSURE REMAINS AND HAS MANY SITES NORTH OF THE I-80 CORRIDOR IN NORTHERN IL HAVING GONE CALM. TEMPERATURES EARLY THIS MORNING HAVE RADIATED INTO THE MID 40S. A LIMITING FACTOR FOR SEEING ACROSS THE BOARD TEMPS MUCH COOLER HAS BEEN THE WINDS ALOFT HOVERING AT 20KT ARND 2KFT AGL...SHOWN BY THE VWP FROM THE WSR-88D KLOT. THIS HAS CREATED JUST ENOUGH FRICTION WITHIN THE BOUNDARY LAYER TO PREVENT TEMPS FROM COMPLETELY RADIATING. ALTHOUGH A FEW TRADITIONAL SPOTS HAVE BEEN ABLE TO COOL INTO THE LOW 40S. IN ADDITIONALLY SHALLOW GROUND FOG WAS BEGINNING TO FORM...HOWEVER THIS WILL LIKELY BE PATCHY AS A WORST CASE SCENARIO THIS MORNING GIVEN THE AFOREMENTIONED WINDS JUST ABOVE THE SFC. WHERE THE FOG FORMS EXPECT TEMPS TO RADIATE FURTHER INTO TO ARND 40 DEGREES BY DAYBREAK. THEN THE SHALLOW FOG SHOULD QUICKLY LIFT BY 14Z. ABUNDANT SUNSHINE COUPLED WITH SOUTHERLY WINDS ARND 10KT WILL ALLOW SFC TEMPS TO STEADILY WARM ABOVE CLIMO TODAY. MANY PLUMES INDICATE TEMPS WILL LIKELY WARM INTO THE LOW TO POSSIBLY MID 70S THIS AFTN...WITH THE WARMEST TEMPS FALLING ALONG SOUTH OF A ROCKFORD TO KANKAKEE LINE. DESPITE THE SOUTHERLY FLOW...THE WARM SFC TEMPS WILL LIKELY AID IN DEVELOPING A LAKE BREEZE TODAY. EXPECT THE LAKE BREEZE TO BE MORE OF AN IMPACT TO NORTHEAST IL RATHER THAN NORTHWEST IN AS THE SOUTHERLY FLOW SHOULD PREVENT MUCH MOVEMENT ONSHORE FOR NORTHWEST IN. THUS AREAS ADJACENT TO LAKE MI WILL LIKELY SEE TEMPS EARLY THIS AFTN COOL INTO THE MID 60S BEHIND THE BREEZE. AFTERNOON MIXING WILL HOLD DEW PTS IN THE MID 40S...WITH MIN RELATIVE HUMIDITY FALLING INTO TO 35 TO 40 PERCENT ACROSS MUCH OF THE FORECAST AREA. SKIES REMAIN MOSTLY CLEAR TONIGHT WITH WINDS REMAINING SOUTHERLY LESS THAN 10KTS...WITH OVERNIGHT LOWS STEADILY COOLING INTO THE LOW/MID 40S. URBAN HEAT ISLAND WILL KEEP THE CHICAGO METRO AREA IN THE LOW/MID 50S. CONFIDENCE...HIGH. WEDNESDAY THROUGH FRIDAY... MUCH OF THE MEDIUM TERM WILL BE DOMINATED BY A BROAD 500MB RIDGE POSITIONED OVER THE EASTERN GREAT LAKES/QUEBEC. ENSEMBLES HAVE CONTINUED TO TREND STRONGER WITH THIS FEATURE...WHICH IS LIKELY A REFLECTION OF THE DIGGING/STRENGTHENING TROUGH ACROSS THE SOUTHWEST CONUS. TOWARDS THE THUR/FRI TIMEFRAME THE TROUGH AXIS BEGINS TO WEAKEN AND PIVOT EAST...WHICH BEGINS TO SIGNAL THAT THE DOWNSTREAM RIDGE WILL LIKELY BEGIN TO WEAKEN AND DRIFT EAST. SFC FEATURES SUPPORT THIS WITH ANTI-CYCLONIC FLOW BEGINNING TO LOOSEN ITS INFLUENCE BY FRI...AS LLVL MOISTURE BEGINS TO STREAM NORTH FROM THE OZARKS INTO THE WESTERN GREAT LAKES REGION. OPERATIONAL SOLUTIONS CONTINUE TO PROG A VORT SPEED MAX ROUNDING THE TROUGH AXIS AND LIFTING NORTH INTO THE HIGH PLAINS FRI...WITH A CHANNEL OF MOISTURE ORIENTED FROM THE NORTHERN PLAINS SOUTH THROUGH TEXAS FRI AFTN. AS THE UPSTREAM TROUGH DRIFTS EAST FRI NIGHT...IT SHOULD BRING THE EARLIEST CHANCES FOR SHOWERS/THUNDERSTORMS TO THE WESTERN CWFA. HOWEVER MID-LVL HEIGHTS REMAIN ELEVATED...WHICH COULD SIGNAL KEEPING FRI NIGHT DRY ACROSS THE ENTIRE CWFA. TEMP PLUMES FOR WED/THUR/FRI ALL SIGNAL ABOVE CLIMO TEMPS...MAINLY IN THE MID 70S. ALTHOUGH COULD SEE TEMPS FRI WARMING INTO THE UPR 70S AS SOUTHERLY FLOW BEGINS TO STRENGTHEN AHEAD OF THE MID-LVL TROUGH. CONFIDENCE...HIGH. SATURDAY THROUGH MONDAY... THE EXTENDED PERIODS CONTINUE TO BE DOMINATED BY A MID-LVL RIDGE PARKED ACROSS EASTERN ONTARIO/QUEBEC...WHICH WILL PLAY A PIVOTAL ROLE IN THE TIMING OF THE UPCOMING WEEKEND SYSTEM. GUIDANCE THROUGH THE END OF THE WEEK WAS INDICATING THE MID-LVL RIDGE WOULD WEAKEN...HOWEVER LATEST ENSEMBLES ARE BEGINNING TO SUGGEST SOME RE-STRENGTHENING MAY TAKE PLACE FOR THE UPCOMING WEEKEND. TEMPS AHEAD OF THE SYSTEM FOR SAT WILL QUICKLY WARM INTO THE MID/UPR 70S UNDER SOUTHERLY FLOW. IF THIS SCENARIO VERIFIES A SLOWER EVOLUTION/ARRIVAL TO THE 500MB SHORTWAVE AND PRECIP CHANCES WILL TAKE PLACE...PUSHING PRECIP INTO SAT NIGHT/SUN. THE CHANNEL OF MOISTURE SHOULD PUSH EAST OF THE AREA SUN AFTN/MON WITH SFC HIGH PRESSURE BUILDING BACK INTO THE REGION...WITH TEMPS COOLING BACK INTO THE 60S. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * POSSIBLE LAKE BREEZE THIS AFTERNOON WITH WIND SHIFT FROM SLY TO SELY OR ELY. KREIN //DISCUSSION...UPDATED 12Z... A LARGE AREA OF HIGH PRESSURE OVER THE OHIO VALLEY AND EASTERN GREAT LAKES WILL BUILD INTO NEW ENGLAND TODAY AND TONIGHT WHILE IT STRENGTHENS. SOUTHERLY FLOW ON THE BACK SIDE OF THIS HIGH WILL ALLOW WINDS TO INCREASE TO 10-12KTS WITH A FEW GUSTS POSSIBLE... MAINLY ACROSS NORTHWEST IL. DESPITE LOW LEVELS WINDS ABOVE 10 KTS...EXPECT WINDS TO TURN SOUTHEASTERLY OR EVEN EASTERLY WITH A LAKE BREEZE CLOSER TO THE IL LAKESHORE. CONCERN THEN BECOMES HOW FAR INLAND WILL IT MOVE. IT IS POSSIBLE THAT IT WILL REACH ORD/MDW BY MID AFTERNOON BUT CONFIDENCE ISN/T HIGH ENOUGH TO INCLUDE A SHIFT TO THE EAST WITH THIS FORECAST AND TRENDS WILL NEED TO BE MONITORED THROUGH THE DAY. SPEEDS WILL DIMINISH UNDER 10 KTS THIS EVENING. //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM CONFIDENCE IN LAKE BREEZE FORMATION...LOW CONFIDENCE THAT IT WILL REACH ORD/MDW. KREIN //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...DRY/VFR. * THURSDAY AND FRIDAY...DRY/VFR. AFTERNOON LAKE BREEZE POSSIBLE EACH DAY. * SATURDAY...CHANCE OF SHRA/TSRA. * SUNDAY...CHANCE SHRA. * MONDAY...DRY/VFR. && .MARINE... 315 AM...HIGH PRESSURE OVER THE OHIO VALLEY WILL STRENGTHEN AS IT MOVES NORTHEAST TO NEW ENGLAND TODAY AND TONIGHT. THIS HIGH WILL SLOWLY DRIFT EAST OVER THE ATLANTIC WHILE A WEAKER RIDGE EXTENDS BACK WEST INTO THE LAKES REGION INTO THURSDAY. MEANWHILE...LOW PRESSURE OVER CENTRAL CANADA WILL MOVE EAST TO ONTARIO WEDNESDAY AS IT SLOWLY WEAKENS. THE GRADIENT BETWEEN THIS APPROACHING LOW AND THE STRENGTHENING HIGH TO THE EAST WILL STEADILY TIGHTEN TODAY INTO TONIGHT PRODUCING INCREASING SOUTHERLY WINDS. SPEEDS LIKELY TO INCREASE UP TO 30 KTS OVER THE NORTH HALF LATER THIS AFTERNOON AND CONTINUE INTO WEDNESDAY MORNING BEFORE THE GRADIENT WEAKENS WEDNESDAY. ANOTHER LOW PRESSURE IS EXPECTED TO MOVE NORTHEAST OVER THE PLAINS THURSDAY NIGHT AND FRIDAY REACHING SOUTHERN MANITOBA FRIDAY NIGHT. THIS CURRENT TRACK WOULD SUGGEST THE STRONGEST WINDS WILL REMAIN WEST OF LAKE MICHIGAN WITH SOUTHERLY WINDS PERHAPS INTO THE 15-25KT RANGE FRIDAY NIGHT AND SATURDAY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 935 AM CDT Tue Oct 8 2013 .DISCUSSION... ISSUED 935 AM CDT Tue Oct 8 2013 High pressure near the Ohio/Pennsylvania border ridges southwest all the way to southeast Oklahoma, and will keep our weather quiet today. Dry air aloft should lead to mainly clear skies through the day, although the RAP and NAM do hint at a bit of diurnal cumulus south of a St Louis to Champaign line for a few hours. Have sent some zone/grid updates mainly to remove the earlier fog mention and update the dew point grids. Also did some minor hourly temperature updates, but overall highs still look reasonable. Geelhart && .AVIATION... ISSUED 607 AM CDT Tue Oct 8 2013 VFR conditions will prevail at all TAF sites next 24hrs. Expecting clear skies through the period as high pressure dominates the area for the next several days. Winds will be out of the south this morning and into the afternoon, and then become southeasterly later this afternoon and into the night and overnight. Wind speeds will be around 10kts this afternoon, but less the rest of the time. Auten && .PREV DISCUSSION... ISSUED 136 AM CDT Tue Oct 8 2013 SHORT TERM...Today through Thursday Ridge of high pressure currently centered over the Ohio River Valley will dominate the weather across central Illinois over the next several days. With calm winds beneath the ridge axis and 06z/1am temp/dewpoint spreads of only 1 to 2 degrees, think shallow ground fog will develop across the E/SE KILX CWA over the next couple of hours. HRRR suggests this as well, with fog generally forming along and southeast of a Danville to Shelbyville line. Will include patchy fog across this area early this morning accordingly. Once fog dissipates, sunny skies can be expected across the board for the remainder of the day. Full sunshine working on dry airmass will boost temperatures several degrees warmer than yesterday, with afternoon highs topping out in the middle to upper 70s. Surface ridge axis will begin to shift northward on Wednesday, allowing light southerly winds to back to a more east-southeast direction. This will temporarily curtail the warming trend, with highs perhaps a degree or two cooler than today in the middle 70s. With high pressure centered over the Great Lakes, both the NAM and GFS suggest some moisture associated with persistent upper low over the SE CONUS may advect northwestward around the periphery of the high into central Illinois on Thursday. Forecast soundings remain dry and forcing is completely absent, so only noticeable change in the weather will be a few more clouds. Under partly to mostly sunny skies, highs will once again reach the middle to upper 70s. LONG TERM...Friday through Monday Warmest day of the forecast period will be Friday, when southerly winds allow highs to approach the 80-degree mark. Meanwhile, closed upper low over the Desert Southwest will begin lifting northeastward into the Northern Plains/Upper Midwest, dragging a cold front into Illinois over the weekend. Latest run of the GFS continues to be rather progressive with the approaching front, bringing scattered showers and thunderstorms into the area Saturday/Saturday night, then quickly departing on Sunday. 12z ECMWF remains slower, with precip holding off until Saturday night into Sunday. Given developing blocking pattern due to upper low meandering northward into the Mid-Atlantic states later this week, would tend to side with the slower ECMWF solution. As a result, will keep chance POPs confined to the western half of the KILX CWA during the day Saturday, with rain chances spreading across the entire area Saturday night. Will hold on to chance POPs in the east on Sunday as well, as front will be slow to depart. After that, a return to dry weather with seasonable temps in the upper 60s and lower 70s can be expected by Monday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
642 AM CDT TUE OCT 8 2013 .DISCUSSION... 307 AM CDT TODAY THROUGH TONIGHT... FORECAST CHALLENGES IN THE NEAR TERM ARE MAX TEMPS AND OVERNIGHT LOWS. BROAD RIDGE OF HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER FOR MUCH OF THE GREAT LAKES AND OHIO VALLEY REGIONS. THE CENTER OF ANTI-CYCLONIC FLOW HAS PUSHED SOUTHEAST OF THE FORECAST AREA INTO CENTRAL INDIANA/OHIO. THIS HAS ALLOWED WINDS EARLY THIS MORNING IN A FEW LOCATIONS TO HAVE TURNED SOUTHERLY. ALTHOUGH ENOUGH INFLUENCE FROM THE HIGH PRESSURE REMAINS AND HAS MANY SITES NORTH OF THE I-80 CORRIDOR IN NORTHERN IL HAVING GONE CALM. TEMPERATURES EARLY THIS MORNING HAVE RADIATED INTO THE MID 40S. A LIMITING FACTOR FOR SEEING ACROSS THE BOARD TEMPS MUCH COOLER HAS BEEN THE WINDS ALOFT HOVERING AT 20KT ARND 2KFT AGL...SHOWN BY THE VWP FROM THE WSR-88D KLOT. THIS HAS CREATED JUST ENOUGH FRICTION WITHIN THE BOUNDARY LAYER TO PREVENT TEMPS FROM COMPLETELY RADIATING. ALTHOUGH A FEW TRADITIONAL SPOTS HAVE BEEN ABLE TO COOL INTO THE LOW 40S. IN ADDITIONALLY SHALLOW GROUND FOG WAS BEGINNING TO FORM...HOWEVER THIS WILL LIKELY BE PATCHY AS A WORST CASE SCENARIO THIS MORNING GIVEN THE AFOREMENTIONED WINDS JUST ABOVE THE SFC. WHERE THE FOG FORMS EXPECT TEMPS TO RADIATE FURTHER INTO TO ARND 40 DEGREES BY DAYBREAK. THEN THE SHALLOW FOG SHOULD QUICKLY LIFT BY 14Z. ABUNDANT SUNSHINE COUPLED WITH SOUTHERLY WINDS ARND 10KT WILL ALLOW SFC TEMPS TO STEADILY WARM ABOVE CLIMO TODAY. MANY PLUMES INDICATE TEMPS WILL LIKELY WARM INTO THE LOW TO POSSIBLY MID 70S THIS AFTN...WITH THE WARMEST TEMPS FALLING ALONG SOUTH OF A ROCKFORD TO KANKAKEE LINE. DESPITE THE SOUTHERLY FLOW...THE WARM SFC TEMPS WILL LIKELY AID IN DEVELOPING A LAKE BREEZE TODAY. EXPECT THE LAKE BREEZE TO BE MORE OF AN IMPACT TO NORTHEAST IL RATHER THAN NORTHWEST IN AS THE SOUTHERLY FLOW SHOULD PREVENT MUCH MOVEMENT ONSHORE FOR NORTHWEST IN. THUS AREAS ADJACENT TO LAKE MI WILL LIKELY SEE TEMPS EARLY THIS AFTN COOL INTO THE MID 60S BEHIND THE BREEZE. AFTERNOON MIXING WILL HOLD DEW PTS IN THE MID 40S...WITH MIN RELATIVE HUMIDITY FALLING INTO TO 35 TO 40 PERCENT ACROSS MUCH OF THE FORECAST AREA. SKIES REMAIN MOSTLY CLEAR TONIGHT WITH WINDS REMAINING SOUTHERLY LESS THAN 10KTS...WITH OVERNIGHT LOWS STEADILY COOLING INTO THE LOW/MID 40S. URBAN HEAT ISLAND WILL KEEP THE CHICAGO METRO AREA IN THE LOW/MID 50S. CONFIDENCE...HIGH. WEDNESDAY THROUGH FRIDAY... MUCH OF THE MEDIUM TERM WILL BE DOMINATED BY A BROAD 500MB RIDGE POSITIONED OVER THE EASTERN GREAT LAKES/QUEBEC. ENSEMBLES HAVE CONTINUED TO TREND STRONGER WITH THIS FEATURE...WHICH IS LIKELY A REFLECTION OF THE DIGGING/STRENGTHENING TROUGH ACROSS THE SOUTHWEST CONUS. TOWARDS THE THUR/FRI TIMEFRAME THE TROUGH AXIS BEGINS TO WEAKEN AND PIVOT EAST...WHICH BEGINS TO SIGNAL THAT THE DOWNSTREAM RIDGE WILL LIKELY BEGIN TO WEAKEN AND DRIFT EAST. SFC FEATURES SUPPORT THIS WITH ANTI-CYCLONIC FLOW BEGINNING TO LOOSEN ITS INFLUENCE BY FRI...AS LLVL MOISTURE BEGINS TO STREAM NORTH FROM THE OZARKS INTO THE WESTERN GREAT LAKES REGION. OPERATIONAL SOLUTIONS CONTINUE TO PROG A VORT SPEED MAX ROUNDING THE TROUGH AXIS AND LIFTING NORTH INTO THE HIGH PLAINS FRI...WITH A CHANNEL OF MOISTURE ORIENTED FROM THE NORTHERN PLAINS SOUTH THROUGH TEXAS FRI AFTN. AS THE UPSTREAM TROUGH DRIFTS EAST FRI NIGHT...IT SHOULD BRING THE EARLIEST CHANCES FOR SHOWERS/THUNDERSTORMS TO THE WESTERN CWFA. HOWEVER MID-LVL HEIGHTS REMAIN ELEVATED...WHICH COULD SIGNAL KEEPING FRI NIGHT DRY ACROSS THE ENTIRE CWFA. TEMP PLUMES FOR WED/THUR/FRI ALL SIGNAL ABOVE CLIMO TEMPS...MAINLY IN THE MID 70S. ALTHOUGH COULD SEE TEMPS FRI WARMING INTO THE UPR 70S AS SOUTHERLY FLOW BEGINS TO STRENGTHEN AHEAD OF THE MID-LVL TROUGH. CONFIDENCE...HIGH. SATURDAY THROUGH MONDAY... THE EXTENDED PERIODS CONTINUE TO BE DOMINATED BY A MID-LVL RIDGE PARKED ACROSS EASTERN ONTARIO/QUEBEC...WHICH WILL PLAY A PIVOTAL ROLE IN THE TIMING OF THE UPCOMING WEEKEND SYSTEM. GUIDANCE THROUGH THE END OF THE WEEK WAS INDICATING THE MID-LVL RIDGE WOULD WEAKEN...HOWEVER LATEST ENSEMBLES ARE BEGINNING TO SUGGEST SOME RE-STRENGTHENING MAY TAKE PLACE FOR THE UPCOMING WEEKEND. TEMPS AHEAD OF THE SYSTEM FOR SAT WILL QUICKLY WARM INTO THE MID/UPR 70S UNDER SOUTHERLY FLOW. IF THIS SCENARIO VERIFIES A SLOWER EVOLUTION/ARRIVAL TO THE 500MB SHORTWAVE AND PRECIP CHANCES WILL TAKE PLACE...PUSHING PRECIP INTO SAT NIGHT/SUN. THE CHANNEL OF MOISTURE SHOULD PUSH EAST OF THE AREA SUN AFTN/MON WITH SFC HIGH PRESSURE BUILDING BACK INTO THE REGION...WITH TEMPS COOLING BACK INTO THE 60S. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * POSSIBLE LAKE BREEZE THIS AFTERNOON. CMS //DISCUSSION...UPDATED 12Z... A LARGE AREA OF HIGH PRESSURE OVER THE OHIO VALLEY AND EASTERN GREAT LAKES WILL BUILD INTO NEW ENGLAND TODAY AND TONIGHT WHILE IT STRENGTHENS. SOUTHERLY FLOW ON THE BACK SIDE OF THIS HIGH WILL ALLOW WINDS TO INCREASE TO 10-12KTS WITH A FEW GUSTS POSSIBLE... MAINLY ACROSS NORTHWEST IL. DESPITE LOW LEVELS WINDS ABOVE 10 KTS...EXPECT WINDS TO TURN SOUTHEASTERLY OR EVEN EASTERLY WITH A LAKE BREEZE CLOSER TO THE IL LAKESHORE. CONCERN THEN BECOMES HOW FAR INLAND WILL IT MOVE. IT IS POSSIBLE THAT IT WILL REACH ORD/MDW BY MID AFTERNOON BUT CONFIDENCE ISN/T HIGH ENOUGH TO INCLUDE A SHIFT TO THE EAST WITH THIS FORECAST AND TRENDS WILL NEED TO BE MONITORED THROUGH THE DAY. SPEEDS WILL DIMINISH UNDER 10 KTS THIS EVENING. //ORD AND MDW CONFIDENCE...UPDATED 12Z... * MEDIUM A LAKE BREEZE WILL FORM...LOW IT WILL REACH ORD/MDW. CMS //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... * WEDNESDAY NIGHT...DRY/VFR. * THURSDAY AND FRIDAY...DRY/VFR. AFTERNOON LAKE BREEZE POSSIBLE EACH DAY. * SATURDAY...CHANCE OF SHRA/TSRA. * SUNDAY...CHANCE SHRA. * MONDAY...DRY/VFR. && .MARINE... 315 AM...HIGH PRESSURE OVER THE OHIO VALLEY WILL STRENGTHEN AS IT MOVES NORTHEAST TO NEW ENGLAND TODAY AND TONIGHT. THIS HIGH WILL SLOWLY DRIFT EAST OVER THE ATLANTIC WHILE A WEAKER RIDGE EXTENDS BACK WEST INTO THE LAKES REGION INTO THURSDAY. MEANWHILE...LOW PRESSURE OVER CENTRAL CANADA WILL MOVE EAST TO ONTARIO WEDNESDAY AS IT SLOWLY WEAKENS. THE GRADIENT BETWEEN THIS APPROACHING LOW AND THE STRENGTHENING HIGH TO THE EAST WILL STEADILY TIGHTEN TODAY INTO TONIGHT PRODUCING INCREASING SOUTHERLY WINDS. SPEEDS LIKELY TO INCREASE UP TO 30 KTS OVER THE NORTH HALF LATER THIS AFTERNOON AND CONTINUE INTO WEDNESDAY MORNING BEFORE THE GRADIENT WEAKENS WEDNESDAY. ANOTHER LOW PRESSURE IS EXPECTED TO MOVE NORTHEAST OVER THE PLAINS THURSDAY NIGHT AND FRIDAY REACHING SOUTHERN MANITOBA FRIDAY NIGHT. THIS CURRENT TRACK WOULD SUGGEST THE STRONGEST WINDS WILL REMAIN WEST OF LAKE MICHIGAN WITH SOUTHERLY WINDS PERHAPS INTO THE 15-25KT RANGE FRIDAY NIGHT AND SATURDAY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 607 AM CDT Tue Oct 8 2013 .DISCUSSION... ISSUED 136 AM CDT Tue Oct 8 2013 SHORT TERM...Today through Thursday Ridge of high pressure currently centered over the Ohio River Valley will dominate the weather across central Illinois over the next several days. With calm winds beneath the ridge axis and 06z/1am temp/dewpoint spreads of only 1 to 2 degrees, think shallow ground fog will develop across the E/SE KILX CWA over the next couple of hours. HRRR suggests this as well, with fog generally forming along and southeast of a Danville to Shelbyville line. Will include patchy fog across this area early this morning accordingly. Once fog dissipates, sunny skies can be expected across the board for the remainder of the day. Full sunshine working on dry airmass will boost temperatures several degrees warmer than yesterday, with afternoon highs topping out in the middle to upper 70s. Surface ridge axis will begin to shift northward on Wednesday, allowing light southerly winds to back to a more east-southeast direction. This will temporarily curtail the warming trend, with highs perhaps a degree or two cooler than today in the middle 70s. With high pressure centered over the Great Lakes, both the NAM and GFS suggest some moisture associated with persistent upper low over the SE CONUS may advect northwestward around the periphery of the high into central Illinois on Thursday. Forecast soundings remain dry and forcing is completely absent, so only noticeable change in the weather will be a few more clouds. Under partly to mostly sunny skies, highs will once again reach the middle to upper 70s. LONG TERM...Friday through Monday Warmest day of the forecast period will be Friday, when southerly winds allow highs to approach the 80-degree mark. Meanwhile, closed upper low over the Desert Southwest will begin lifting northeastward into the Northern Plains/Upper Midwest, dragging a cold front into Illinois over the weekend. Latest run of the GFS continues to be rather progressive with the approaching front, bringing scattered showers and thunderstorms into the area Saturday/Saturday night, then quickly departing on Sunday. 12z ECMWF remains slower, with precip holding off until Saturday night into Sunday. Given developing blocking pattern due to upper low meandering northward into the Mid-Atlantic states later this week, would tend to side with the slower ECMWF solution. As a result, will keep chance POPs confined to the western half of the KILX CWA during the day Saturday, with rain chances spreading across the entire area Saturday night. Will hold on to chance POPs in the east on Sunday as well, as front will be slow to depart. After that, a return to dry weather with seasonable temps in the upper 60s and lower 70s can be expected by Monday. Barnes && .AVIATION... ISSUED 607 AM CDT Tue Oct 8 2013 VFR conditions will prevail at all TAF sites next 24hrs. Expecting clear skies through the period as high pressure dominates the area for the next several days. Winds will be out of the south this morning and into the afternoon, and then become southeasterly later this afternoon and into the night and overnight. Wind speeds will be around 10kts this afternoon, but less the rest of the time. Auten && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
252 AM MDT THU OCT 10 2013 .UPDATE... ISSUED AT 806 PM MDT WED OCT 9 2013 UPDATED FORECAST TO INCLUDE A WIND ADVISORY ACROSS ROUGHLY THE SOUTHEAST 2/3 OF THE FORECAST AREA FROM MID DAY THROUGH THE EVENING HOURS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 149 PM MDT WED OCT 9 2013 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW LARGE SCALE TROUGH ACROSS WESTERN CONUS WITH CLOSED 548DM H5 CENTER OVER WESTCENTRAL CALIFORNIA. 135KT H3 JET IS ROUNDING WESTERN EXTENT OF THIS TROUGH WITH WELL DEFINED PV HEIGHT ANOMALY OVER SOUTHERN CALIFORNIA. SW FLOW AHEAD OF THIS FEATURE IS IN PLACE ACROSS THE PLAINS. AT THE SURFACE A STATIONARY FRONT IS CURRENTLY EXTENDING FORM THE NORTHERN PLAINS ACROSS CENTRAL NEBRASKA TO NEAR KGLD AND WEST TOWARDS NORTHCENTRAL COLORADO. TONIGHT...WITH DRY/STABLE AIR MASS IN PLACE WE SHOULD SEE DRY CONDITIONS CONTINUE THROUGH TONIGHT. FRONT IS PROGGED TO LIFT NORTH THROUGH THE NIGHT WITH SLIGHTLY WARMER AIR MASS BUILDING BACK OVER THE CWA. WHILE H85 TEMPS ARENT TOO DIFFERENT THAN LAST NIGHT...WINDS MAY REMAIN IN THE 10-12KT RANGE WHICH COULD LIMIT RADIATIONAL COOLING. I WENT AHEAD AND BUMPED OVERNIGHT LOWS UP A LITTLE...THOUGH WITH CLEAR SKIES IF WINDS DIMINISH WE COULD END UP WITH LOWS SIMILAR TO LAST NIGHT. THURSDAY...LEE TROUGH DEEPENS THROUGH THE DAY THURSDAY WITH TIGHT PRESSURE GRADIENT DEVELOPING BY THURSDAY AFTERNOON. CONFIDENCE IS HIGH IN WINDY CONDITIONS...HOWEVER THERE ARE SOME MODEL DISCREPANCIES REGARDING WINDS ALOFT...AND THUS PEAK GUST POTENTIAL. BASED ON BL/ML WINDS ON THE NAM I WOULD BE CONFIDENT IN A PERIOD OF ADVISORY LEVEL WINDS (GUSTS 45-50MPH). GFS CONTINUES TO BE THE STRONGER MODEL...WITH HIGH END ADVISORY/NEAR WARNING CRITERIA. THE STRONGEST WINDS APPEAR TO OCCUR AROUND 00Z WHEN MIXING MIGHT NOT BE AS DEEP (CONSIDERING THE EARLIER SUNSET THIS TIME OF YEAR)...SO I WAS NOT CONFIDENT ENOUGH TO ADD A HIGHLIGHT AT THIS TIME. PRECIPITATION CHANCES INCREASE FROM MID AFTERNOON THROUGH 00Z AS LAPSE RATES STEEPEN ALONG SURFACE TROUGH IN EASTERN COLORADO. TD VALUES GENERALLY IN THE 40S WILL LIMIT CAPE TO 500 J/KG OR LESS...AND THUNDERSTORMS WILL BE HIGH BASED (LCL/LFC AROUND 10KFT). AT THE SAME TIME UNIDIRECTIONAL SHEER WILL BE IMPRESSIVE AHEAD OF TROUGH BY LATE AFTERNOON...AND SOUNDINGS ARE INDICATIVE OF STRONG DOWNDRAFT POTENTIAL. .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 252 AM MDT THU OCT 10 2013 A TROUGH SITUATED OVER THE PACIFIC NORTHWEST AT THE START OF THE EXTENDED PERIOD WILL MOVE QUICKLY SOUTHEASTWARD TOWARD THE CENTRAL ROCKIES BY LATE SUNDAY. WEAK UPPER RIDGING WILL SHIFT EAST DURING THE DAY SUNDAY AND SIGNIFICANT STRENGTHENING OF MID/UPPER FLOW OCCURS. IN RESPONSE TO THE APPROACHING SYSTEM...STRONG SOUTHEASTERLY LOW LEVEL FLOW BECOMES REESTABLISHED ACROSS THE HIGH PLAINS. THE PREVIOUS FRONTAL INTRUSION WILL HAVE ONLY MADE IT INTO THE SOUTHERN PLAINS AND POOLING OF LOW LEVEL MOISTURE OVER ARKLATEX REGION WILL QUICKLY BE ADVECTED NORTHWESTWARD INTO THE AREA BY SUNDAY NIGHT INTO MONDAY. MODELS BEGIN TO DIFFER ON TIMING AND CHARACTER OF THE TROUGH BY THIS TIME. OPERATIONAL GFS REMAINS THE FASTEST WITH PROGRESSING THIS SYSTEM EASTWARD...EVEN CONSIDERABLY FASTER THAN GFS ENSEMBLE MEAN. ECMWF AND GEM ARE SIMILAR IN PLACEMENT/TIMING AND BOTH ARE MORE CLOSED OFF. THE SLOWER SOLUTION OF THE ECMWF AND GEM IS PROBABLY MORE REALISTIC AND THE FORECAST IS WEIGHTED TOWARD A BLEND OF THE TWO WITH REGARD TO TIMING. GREATEST PRECIPITATION CHANCES ARE DEPICTED AFTER LOW LEVEL MOISTURE / HIGH PWATS ABOVE CLIMO ARRIVE AND BEFORE FRONTAL PASSAGE WHICH WOULD OCCUR MONDAY EVENING. A CURSORY GLANCE AT GFS FORECAST SOUNDINGS INDICATES AT LEAST SOME ELEVATED INSTABILITY PRESENT BUT THE BOUNDARY LAYER IS SHOWN TO BE RATHER COOL/STABLE...PERHAPS A BIT TOO MUCH GIVEN THE SYNOPTIC PATTERN. WITH A SLIGHTLY FURTHER NORTHWEST TRACK OF SURFACE LOW...CONSIDERABLE UPWARD ADJUSTMENT OF TEMPERATURES LATE SUNDAY THROUGH MONDAY WOULD BE NEEDED ACROSS AT LEAST THE EASTERN PORTION OF THE AREA AND A MORE FAVORABLE THERMODYNAMIC PROFILE MAY BE PRESENT FOR A MORE ROBUST CONVECTIVE EPISODE. FOR NOW...HAVE CONFINED GREATEST THUNDER CHANCES TO THE SOUTHEASTERN PORTION OF THE AREA. ADDITIONALLY...WITH PWAT VALUES APPROACHING THE 99TH PERCENTILE FOR OCTOBER AND THE 75TH PERCENTILE BY MID SUMMER STANDARDS...HEAVY RAINFALL IS A POSSIBILITY. MODEL SOLUTION DIFFERENCES CONTINUE TO GROW INTO EARLY/MID WEEK. IN THE ECMWF THE TROUGH BECOMES ELONGATED ACROSS THE WESTERN CONUS KEEPING OUR REGION IN SOUTHWESTERLY FLOW ALOFT THROUGH WEDNESDAY. A CLOSED LOW BEGINS TO EVOLVE OVER NORTHERN UTAH AND WESTERN WYOMING BY LATE TUESDAY AND WEDNESDAY AND HEIGHT VALUES THAT WOULD SUPPORT NEAR OR ABOVE NORMAL TEMPERATURES. ON THE CONTRARY...GFS HAS THE UPPER LEVEL TROUGH AXIS POSITIONED WELL EAST OF THE AREA AND COOL NORTHWESTERLY SURFACE FLOW WITH BELOW NORMAL TEMPERATURES AS INDICATED BY MEX MOS. GFS ENSEMBLE IS A COMPROMISE BUT IS CLOSER TO THE MORE PROGRESSIVE OPERATIONAL GFS. CONFIDENCE IN THE LATTER HALF OF THE EXTENDED PERIOD IS SO LOW THAT A FORECAST OF CLIMATOLOGICALLY NORMAL CONDITIONS WOULD PROBABLY THE BEST APPROACH. HOWEVER...ALLBLEND SEEMS TO BE SIGNIFICANTLY WEIGHTED TOWARD THE GFS/GEFS AND DID NOT DEVIATED FROM THAT AT THIS TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1149 PM MDT WED OCT 9 2013 VFR CONDITIONS SHOULD PREVAIL AT BOTH MCK AND GLD THROUGH THE TAF PERIOD. A FEW HIGH CLOUDS WILL BE OBSERVED ALONG WITH LIGHT WINDS OVERNIGHT THAT WILL BECOME STRONG AND GUSTY OUT OF THE SOUTH BETWEEN 18Z-03Z AS THE SURFACE TROUGH OVER EASTERN COLORADO AND WESTERN KANSAS DEEPENS AHEAD OF THE MAIN UPPER TROUGH MOVING THROUGH THE SOUTHWEST U.S. AND INTO THE CENTRAL ROCKIES BY 06Z THURSDAY NIGHT. AHEAD OF THE SURFACE TROUGH AND MAIN UPPER TROUGH...THUNDERSTORMS WILL LIKELY FORM AND SPREAD EASTWARD THROUGH THE EVENING. STRONG GUSTY WINDS ARE POSSIBLE FROM THESE STORMS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ002>004-013>016-027>029-041-042. CO...WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR COZ092. NE...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING FOR NEZ081. && $$ UPDATE...LOCKHART SHORT TERM...DR LONG TERM...BRB AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1202 AM MDT THU OCT 10 2013 .UPDATE... ISSUED AT 806 PM MDT WED OCT 9 2013 UPDATED FORECAST TO INCLUDE A WIND ADVISORY ACROSS ROUGHLY THE SOUTHEAST 2/3 OF THE FORECAST AREA FROM MID DAY THROUGH THE EVENING HOURS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 149 PM MDT WED OCT 9 2013 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW LARGE SCALE TROUGH ACROSS WESTERN CONUS WITH CLOSED 548DM H5 CENTER OVER WESTCENTRAL CALIFORNIA. 135KT H3 JET IS ROUNDING WESTERN EXTENT OF THIS TROUGH WITH WELL DEFINED PV HEIGHT ANOMALY OVER SOUTHERN CALIFORNIA. SW FLOW AHEAD OF THIS FEATURE IS IN PLACE ACROSS THE PLAINS. AT THE SURFACE A STATIONARY FRONT IS CURRENTLY EXTENDING FORM THE NORTHERN PLAINS ACROSS CENTRAL NEBRASKA TO NEAR KGLD AND WEST TOWARDS NORTHCENTRAL COLORADO. TONIGHT...WITH DRY/STABLE AIR MASS IN PLACE WE SHOULD SEE DRY CONDITIONS CONTINUE THROUGH TONIGHT. FRONT IS PROGGED TO LIFT NORTH THROUGH THE NIGHT WITH SLIGHTLY WARMER AIR MASS BUILDING BACK OVER THE CWA. WHILE H85 TEMPS ARENT TOO DIFFERENT THAN LAST NIGHT...WINDS MAY REMAIN IN THE 10-12KT RANGE WHICH COULD LIMIT RADIATIONAL COOLING. I WENT AHEAD AND BUMPED OVERNIGHT LOWS UP A LITTLE...THOUGH WITH CLEAR SKIES IF WINDS DIMINISH WE COULD END UP WITH LOWS SIMILAR TO LAST NIGHT. THURSDAY...LEE TROUGH DEEPENS THROUGH THE DAY THURSDAY WITH TIGHT PRESSURE GRADIENT DEVELOPING BY THURSDAY AFTERNOON. CONFIDENCE IS HIGH IN WINDY CONDITIONS...HOWEVER THERE ARE SOME MODEL DISCREPANCIES REGARDING WINDS ALOFT...AND THUS PEAK GUST POTENTIAL. BASED ON BL/ML WINDS ON THE NAM I WOULD BE CONFIDENT IN A PERIOD OF ADVISORY LEVEL WINDS (GUSTS 45-50MPH). GFS CONTINUES TO BE THE STRONGER MODEL...WITH HIGH END ADVISORY/NEAR WARNING CRITERIA. THE STRONGEST WINDS APPEAR TO OCCUR AROUND 00Z WHEN MIXING MIGHT NOT BE AS DEEP (CONSIDERING THE EARLIER SUNSET THIS TIME OF YEAR)...SO I WAS NOT CONFIDENT ENOUGH TO ADD A HIGHLIGHT AT THIS TIME. PRECIPITATION CHANCES INCREASE FROM MID AFTERNOON THROUGH 00Z AS LAPSE RATES STEEPEN ALONG SURFACE TROUGH IN EASTERN COLORADO. TD VALUES GENERALLY IN THE 40S WILL LIMIT CAPE TO 500 J/KG OR LESS...AND THUNDERSTORMS WILL BE HIGH BASED (LCL/LFC AROUND 10KFT). AT THE SAME TIME UNIDIRECTIONAL SHEER WILL BE IMPRESSIVE AHEAD OF TROUGH BY LATE AFTERNOON...AND SOUNDINGS ARE INDICATIVE OF STRONG DOWNDRAFT POTENTIAL. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 1246 PM MDT WED OCT 9 2013 STRONG SHORTWAVE TROUGH WILL BRING WIDESPREAD SHOWERS AND THUNDERSTORMS THURSDAY EVENING TO THE AREA. LACK OF MOISTURE/WEAK INSTABILITY CONTINUE TO BE THE LIMITING FACTORS FOR MORE INTENSE CONVECTION. NONETHELESS...HIGH BASED THUNDERSTORMS WILL DEVELOP ALONG THE LEE TROUGH IN EASTERN COLORADO AND MOVE EAST AS A SQUALL LINE IN THE EVENING...WHILE INDIVIDUAL CELLS RACE NORTHEAST AT AROUND 50KTS. DESPITE FAVORABLE SHEAR PROFILES...UPDRAFTS WILL STRUGGLE TO ORGANIZE GIVEN SBCAPE OF LESS THAN 500 J/KG. AS A RESULT...HAIL THREAT SEEMS MINIMAL AND TORNADO THREAT EVEN LESS...HOWEVER DAMAGING WINDS WILL BE LIKELY WITH STRONGEST STORMS GIVEN HIGH BASES AND UNIDIRECTIONAL WINDS THROUGH NEARLY THE ENTIRE TROPOSPHERE. PRECIPITATION WILL END BY 06Z AS SYSTEM QUICKLY LIFTS INTO THE NORTHERN PLAINS. FRIDAY WILL BE COOLER AND DRY...BUT ANOTHER VORT LOBE WILL ROTATE THROUGH THE BASE OF THE LONGWAVE TROUGH FRIDAY NIGHT. HOWEVER...THERE WILL NOT BE ENOUGH TIME FOR MOISTURE RETURN AND THE WEAK LIFT WILL HAVE DIFFICULTY IN GENERATING MORE THAN A FEW ISOLATED TO WIDELY SCATTERED RAIN SHOWERS ACROSS NORTHERN PORTIONS OF THE AREA FRIDAY NIGHT THROUGH SATURDAY MORNING. SHORTWAVE RIDGING WILL BRIEFLY FOLLOW SATURDAY AFTERNOON AND SATURDAY NIGHT...HOWEVER ANOTHER WEAK TROUGH WILL BE MOVING THROUGH THE FLOW ON SUNDAY BRINGING LOW CHANCES OF SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM AS SOME WEAK INSTABILITY IS FORECAST. THE MAIN SYSTEM WILL EJECT ACROSS THE CENTRAL AND NORTHERN ROCKIES MONDAY WITH PRECIPITATION CHANCES CONTINUING AS ASSOCIATED SURFACE COLD FRONT MOVES THROUGH DURING THE DAY ON MONDAY. BREEZY NORTHWEST WINDS WILL FOLLOW FRONTAL PASSAGE MONDAY AFTERNOON AND EVENING AS PRECIPITATION COMES TO AN END. THE REMAINDER OF THE PERIOD (TUESDAY AND WEDNESDAY) WILL SEE DRY NORTHWEST FLOW WITH TEMPERATURES SLIGHTLY BELOW NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1149 PM MDT WED OCT 9 2013 VFR CONDITIONS SHOULD PREVAIL AT BOTH MCK AND GLD THROUGH THE TAF PERIOD. A FEW HIGH CLOUDS WILL BE OBSERVED ALONG WITH LIGHT WINDS OVERNIGHT THAT WILL BECOME STRONG AND GUSTY OUT OF THE SOUTH BETWEEN 18Z-03Z AS THE SURFACE TROUGH OVER EASTERN COLORADO AND WESTERN KANSAS DEEPENS AHEAD OF THE MAIN UPPER TROUGH MOVING THROUGH THE SOUTHWEST U.S. AND INTO THE CENTRAL ROCKIES BY 06Z THURSDAY NIGHT. AHEAD OF THE SURFACE TROUGH AND MAIN UPPER TROUGH...THUNDERSTORMS WILL LIKELY FORM AND SPREAD EASTWARD THROUGH THE EVENING. STRONG GUSTY WINDS ARE POSSIBLE FROM THESE STORMS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY FROM NOON MDT /1 PM CDT/ TO 9 PM MDT /10 PM CDT/ THURSDAY FOR KSZ002>004-013>016-027>029-041-042. CO...WIND ADVISORY FROM NOON TO 9 PM MDT THURSDAY FOR COZ092. NE...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM CDT THIS EVENING FOR NEZ081. && $$ UPDATE...LOCKHART SHORT TERM...DR LONG TERM...024 AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
330 AM EDT THU OCT 10 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 239 PM EDT WED OCT 9 2013 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG OVER THE E HALF OF THE CONUS DOWNWIND OF TROF OVER THE W. AT THE SFC...HI PRES IS SITUATED OVER NEW ENGLAND...WITH WEAKENING LO PRES OVER NW ONTARIO ASSOCIATED WITH CNDN SHRTWV RIDING OVER UPR RDG. THE CWA IS DOMINATED BY THE LLVL SW FLOW BTWN THESE FEATURES. BUT BECAUSE THE SFC LO IS WEAKENING WITH PRES RISES OBSVD OVER THE SFC LO...THE GRADIENT IS WEAKENING STEADILY WITH TIME. SO SW WINDS THIS AFTN ARE NOT AS GUSTY AS YDAY DESPITE DAYTIME HEATING/MIXING. OTRW...THE LOCAL AND UPSTREAM 12Z RAOBS SHOW A RELATIVELY DRY LLVL AIRMASS...SO THERE IS NOTHING MORE THAN PATCHY HI CLDS TO THE SW OF SOME THICKER CLDS IN ONTARIO ASSOCIATED WITH THE LO WELL N OF THE BORDER. THE ONLY EXCEPTION WAS A BIT OF LO CLD THAT DVLPD DOWNWIND OF LK MI NEAR MANISTIQUE WHERE THE SW FLOW OFF THE WATER HAS LIFTED SFC DEWPTS AS HI AS 55 TO 60. WITH A RIBBON OF H85 TEMPS UP TO 15C STREAMING INTO THE WRN CWA IN THE SW FLOW...TEMPS ARE RUNNING WELL ABV NORMAL EARLY THIS AFTN WITH READINGS AS HI AS THE LO 70S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF LK MI. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH DRY...ACYC SW FLOW ARND SFC HI PRES STRETCHING FM THE NE COAST INTO THE GREAT LKS FCST TO DOMINATE THRU THU. TNGT...EXPECT LO TEMPS TNGT TO FALL A BIT MORE THAN LAST NGT WITH DRY AIR LINGERING UNDER WEAKENING PRES GRADIENT/SW FLOW AS HIER PRES SLOWLY EXPANDS TO THE W. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCENTRAL AND E...CLOSER TO THE WEAKEST GRADIENT/LOWER PWATS AOB 0.5 INCH. WITH THESE IMPROVED RADIATIONAL COOLING CONDITIONS OVER HIER DEWPTS OBSVD THIS AFTN...EXPECT PATCHY FOG IN THESE AREAS. THU...LOOKS LIKE ANOTHER PLEASANT OCT DAY WITH DRY SW FLOW FCST TO DOMINATE AND LEAD TO MOSUNNY CONDITIONS. H85 TEMPS ARE FCST NEAR 14C...ALMOST THE SAME AS TDAY...SO EXPECT MAX TEMPS TO BE SIMILAR TO THIS AFTN. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 330 AM EDT THU OCT 10 2013 UPPER AIR PATTERN WILL BE A TROUGH AND CLOSED LOW OVER THE NORTHERN PLAINS 12Z FRI WITH THE LOW HEADING NE AND THE TROUGH MOVING INTO THE UPPER GREAT LAKES ON SAT. THIS TROUGH MOVES THROUGH SAT NIGHT. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE OVER THE AREA FRI NIGHT AND SAT AND GFS SHOWS THIS AS WELL. SINCE VERY LITTLE MOISTURE IS THERE TO WORK WITH FOR FRI NIGHT...SLIGHT CHANCE POPS FOR THE WEST HALF LOOK GOOD. ON SATURDAY...A BIT MORE MOISTURE COMES IN AND WENT WITH CHANCE POPS ACROSS THE CENTRAL CWA. THE PCPN MOVES OUT SAT NIGHT AND LOW CHANCE TO CHANCE POPS OVER THE EAST STILL LOOK GOOD. AS FOR TEMPERATURES...MADE A FEW ADJUSTMENTS HERE AND THERE TAKING INTO ACCOUNT SOME DOWNSLOPE AREAS WITH WEST OR SOUTH WINDS. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE WESTERN U.S. AND A SHORTWAVE TROUGH OVER THE UPPER GREAT LAKES 12Z SUN. THE TROUGH OVER THE WESTERN U.S. DIGS INTO THE DESERT SW 12Z MON AND THIS TROUGH MOVES INTO THE PLAINS 12Z TUE AND INTO THE UPPER GREAT LAKES 12Z WED. TEMPERATURES FALL TO BELOW NORMAL THIS PERIOD STARTING TUE. THERE WILL BE A CHANCE OF RAIN STARTING MON NIGHT LASTING INTO WED WITH A STORM SYSTEM PASSING BY TO THE SOUTH AND CHANCE POPS COVERS THIS FOR NOW...BUT THIS IS STARTING TO LOOK LIKE A GOOD RAIN PRODUCER AND FEELING IS FUTURE SHIFTS WILL PROBABLY HAVE TO BOOST POPS AS THIS APPROACHES THE AREA. IT WILL BE DRY SUNDAY THROUGH MONDAY AND NOTICEABLY COOLER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1208 AM EDT THU OCT 10 2013 DRY HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE TAF SITES THIS FCST PERIOD. THE ONE EXCEPTION MAY BE SAW LATE TONIGHT OR EARLY THU...WHERE SOME FOG COULD DEVELOP. WITH THE LOW LEVEL FLOW MORE SSW COMPARED TO SSE OFF LAKE MI...PROBABILITY OF FOG FORMATION WAS LOW AND NOT INCLUDED IN THE TAF. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 312 AM EDT THU OCT 10 2013 LAKE SUPERIOR WILL REMAIN IN BETWEEN HIGH PRESSURE TO OUR E AND LOW PRESSURE TO THE W. THE RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE GREAT LAKES AND NEW ENGLAND STATES WILL SLOWLY BE REPLACED BY LOW PRESSURE NEARING FROM THE SOUTHWEST. LOW PRESSURE OFF THE COLORADO ROCKIES THIS AFTERNOON WILL LIFT ACROSS THE DAKOTAS FRIDAY...BEFORE SURGING INTO HUDSON BAY SATURDAY NIGHT AND SUNDAY. THIS WILL ALLOW A TROUGH TO PUSH ACROSS LAKE SUPERIOR SATURDAY AND SATURDAY NIGHT. AHEAD OF THE TROUGH...S GUSTS OF 25-30KTS WILL BE POSSIBLE FRIDAY NIGHT THROUGH SATURDAY. EXPECT LARGE HIGH PRESSURE OVER THE PLAINS STATES TO QUICKLY PUSH ACROSS THE UPPER GREAT LAKES SUNDAY AND MONDAY. LOOKING FARTHER OUT...MID WEEK LOOKS COOL AND BREEZY. ALTHOUGH THERE IS SOME VARIABILITY IN TIMING AND INTENSITY...MORE 20-30KT WINDS IF NOT GALE FORCE GUSTS WILL BE POSSIBLE WEDNESDAY INTO THURSDAY AS LOW PRESSURE CROSSES THE REGION FROM THE SW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...07 AVIATION...JLB MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
313 AM EDT THU OCT 10 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 239 PM EDT WED OCT 9 2013 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG OVER THE E HALF OF THE CONUS DOWNWIND OF TROF OVER THE W. AT THE SFC...HI PRES IS SITUATED OVER NEW ENGLAND...WITH WEAKENING LO PRES OVER NW ONTARIO ASSOCIATED WITH CNDN SHRTWV RIDING OVER UPR RDG. THE CWA IS DOMINATED BY THE LLVL SW FLOW BTWN THESE FEATURES. BUT BECAUSE THE SFC LO IS WEAKENING WITH PRES RISES OBSVD OVER THE SFC LO...THE GRADIENT IS WEAKENING STEADILY WITH TIME. SO SW WINDS THIS AFTN ARE NOT AS GUSTY AS YDAY DESPITE DAYTIME HEATING/MIXING. OTRW...THE LOCAL AND UPSTREAM 12Z RAOBS SHOW A RELATIVELY DRY LLVL AIRMASS...SO THERE IS NOTHING MORE THAN PATCHY HI CLDS TO THE SW OF SOME THICKER CLDS IN ONTARIO ASSOCIATED WITH THE LO WELL N OF THE BORDER. THE ONLY EXCEPTION WAS A BIT OF LO CLD THAT DVLPD DOWNWIND OF LK MI NEAR MANISTIQUE WHERE THE SW FLOW OFF THE WATER HAS LIFTED SFC DEWPTS AS HI AS 55 TO 60. WITH A RIBBON OF H85 TEMPS UP TO 15C STREAMING INTO THE WRN CWA IN THE SW FLOW...TEMPS ARE RUNNING WELL ABV NORMAL EARLY THIS AFTN WITH READINGS AS HI AS THE LO 70S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF LK MI. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH DRY...ACYC SW FLOW ARND SFC HI PRES STRETCHING FM THE NE COAST INTO THE GREAT LKS FCST TO DOMINATE THRU THU. TNGT...EXPECT LO TEMPS TNGT TO FALL A BIT MORE THAN LAST NGT WITH DRY AIR LINGERING UNDER WEAKENING PRES GRADIENT/SW FLOW AS HIER PRES SLOWLY EXPANDS TO THE W. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCENTRAL AND E...CLOSER TO THE WEAKEST GRADIENT/LOWER PWATS AOB 0.5 INCH. WITH THESE IMPROVED RADIATIONAL COOLING CONDITIONS OVER HIER DEWPTS OBSVD THIS AFTN...EXPECT PATCHY FOG IN THESE AREAS. THU...LOOKS LIKE ANOTHER PLEASANT OCT DAY WITH DRY SW FLOW FCST TO DOMINATE AND LEAD TO MOSUNNY CONDITIONS. H85 TEMPS ARE FCST NEAR 14C...ALMOST THE SAME AS TDAY...SO EXPECT MAX TEMPS TO BE SIMILAR TO THIS AFTN. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 239 PM EDT WED OCT 9 2013 AT 00Z FRI...THERE WILL BE AN UPPER RIDGE OVER THE CWA THAT WILL GIVE WAY TO A LOW PRESSURE SYSTEM MOVING FROM NE AT 12Z FRI TO FAR SRN MANITOBA AT 12Z SAT. FRI WILL BE QUIET WITH NO PRECIP EXPECTED DUE TO THE RIDGE BEING OVERHEAD...BUT WITH 850MB TEMPS AROUND 14C...TEMPS WILL BE WELL ABOVE NORMAL WITH HIGHS IN THE 60S AND 70S. AFTER 12Z SAT...MODEL DISAGREEMENT ON THE TIMING/TRACK OF THE SYSTEM IS MORE UNCERTAIN. THE 12Z/09 GFS KEEPS THE LOW MOVING RAPIDLY NNE TO HUDSON BAY BY 00Z SUN...WHILE 00Z/09 ECMWF HANGS THE LOW OVER ONTARIO WHILE WEAKENING...AND FINALLY MOVING TO JAMES BAY AROUND 06Z MON. THE 00Z/09 GEM SOLUTION IS BETWEEN THE GFS AND ECMWF WITH TIMING/TRACK. PRECIP OVER THE CWA FROM THIS SYSTEM WILL MAINLY RESULT FROM THE ASSOCIATED COLD FRONT MOVING THROUGH. OF COURSE...THERE ARE ALSO SOME TIMING DIFFERENCES WITH TIMING OF FROPA. THE GFS MOVES THE FRONT FROM THE WRN U.P. AT 18Z SAT TO THE ERN CWA AROUND 06Z SUN...WITH THE ECMWF BEING AROUND 6 HOURS SLOWER. THE GEM MATCHES UP PRETTY CLOSE TO THE GFS WITH FROPA TIMING. THERE MAY BE SOME SHOWERS OVER THE WRN CWA FRI NIGHT AS THE LOW MOVES TO THE W...BUT OTHERWISE MOST PRECIP WITH THE FRONT SHOULD BE OVER THE CENTRAL AND ERN CWA WHERE THE FRONT WILL INTERACT WITH BETTER INSTABILITY AND MAY BE BACKED UP BY AN UPPER SHORTWAVE TROUGH. WILL NOT GO COMPLETELY DRY OVER THE W...BUT WILL HAVE HIGHEST POPS CENTRAL AND E AND TIMING CLOSER THE GFS/GEM SOLUTIONS. COLDER AIR WILL FILTER IN BEHIND THE SYSTEM...WITH 850MB TEMPS FALLING INTO THE LOW SINGLE DIGITS ABOVE AND MAYBE JUST BELOW ZERO BY LATE SUN/SUN NIGHT. THIS IS WHERE THE MODEL DIFFERENCES BECOME MORE SIGNIFICANT AS THE GFS AND GEM USHER IN DRY HIGH PRESSURE FOR SUN NIGHT WHILE THE ECMWF SOLUTION WITH THE LAGGING LOW WILL KEEP MORE CLOUDS OVERHEAD. WITH THE CLOUDIER ECMWF SOLUTION...LOW TEMPS SUN NIGHT SHOULD FALL INTO THE UPPER 30S TO MID 40S. THE LESS CLOUDY SOLUTIONS WOULD LIKELY RESULT IN A DECENT FREEZE AWAY FROM THE IMMEDIATE SHORES OF THE GREAT LAKES. WILL GO WITH A MIDDLE OF THE ROAD APPROACH AND KEEP CONSENSUS LOW TEMPS FROM THE MID 30S TO MID 40S. THINGS BECOME MORE UNCERTAIN MON THROUGH NEXT WED AS MODELS CONTINUE TO POINT TO A MAJOR PATTERN CHANGE FROM THIS PORTION OF THE COUNTRY. MODELS GENERALLY SHOW MUCH INCREASED UPPER TROUGHING OVER THE ERN HAVE OF THE CONUS...RESULTING IN COLDER TEMPERATURES AND GREATER STRENGTH/FREQUENCY OF SYSTEMS MOVING THROUGH THE REGION. DEFINITELY LOOKS COLDER WITH TEMPS EVEN FALLING TO BELOW NORMAL VALUES. POPS ARE FAR MORE UNCERTAIN AS SYSTEM STRENGTH/TRACK IS FAR FROM CERTAIN. TEMPS DO NOT LOOK QUITE COLD ENOUGH TO ADD MIXED PRECIP TO THE FORECAST...ESPECIALLY GIVEN UNCERTAINTY INVOLVED. USED A CONSENSUS OF MODEL GUIDANCE FOR THIS PORTION OF THE FORECAST PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1208 AM EDT THU OCT 10 2013 DRY HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE TAF SITES THIS FCST PERIOD. THE ONE EXCEPTION MAY BE SAW LATE TONIGHT OR EARLY THU...WHERE SOME FOG COULD DEVELOP. WITH THE LOW LEVEL FLOW MORE SSW COMPARED TO SSE OFF LAKE MI...PROBABILITY OF FOG FORMATION WAS LOW AND NOT INCLUDED IN THE TAF. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 312 AM EDT THU OCT 10 2013 LAKE SUPERIOR WILL REMAIN IN BETWEEN HIGH PRESSURE TO OUR E AND LOW PRESSURE TO THE W. THE RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE GREAT LAKES AND NEW ENGLAND STATES WILL SLOWLY BE REPLACED BY LOW PRESSURE NEARING FROM THE SOUTHWEST. LOW PRESSURE OFF THE COLORADO ROCKIES THIS AFTERNOON WILL LIFT ACROSS THE DAKOTAS FRIDAY...BEFORE SURGING INTO HUDSON BAY SATURDAY NIGHT AND SUNDAY. THIS WILL ALLOW A TROUGH TO PUSH ACROSS LAKE SUPERIOR SATURDAY AND SATURDAY NIGHT. AHEAD OF THE TROUGH...S GUSTS OF 25-30KTS WILL BE POSSIBLE FRIDAY NIGHT THROUGH SATURDAY. EXPECT LARGE HIGH PRESSURE OVER THE PLAINS STATES TO QUICKLY PUSH ACROSS THE UPPER GREAT LAKES SUNDAY AND MONDAY. LOOKING FARTHER OUT...MID WEEK LOOKS COOL AND BREEZY. ALTHOUGH THERE IS SOME VARIABILITY IN TIMING AND INTENSITY...MORE 20-30KT WINDS IF NOT GALE FORCE GUSTS WILL BE POSSIBLE WEDNESDAY INTO THURSDAY AS LOW PRESSURE CROSSES THE REGION FROM THE SW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...JLB MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1208 AM EDT THU OCT 10 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 239 PM EDT WED OCT 9 2013 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG OVER THE E HALF OF THE CONUS DOWNWIND OF TROF OVER THE W. AT THE SFC...HI PRES IS SITUATED OVER NEW ENGLAND...WITH WEAKENING LO PRES OVER NW ONTARIO ASSOCIATED WITH CNDN SHRTWV RIDING OVER UPR RDG. THE CWA IS DOMINATED BY THE LLVL SW FLOW BTWN THESE FEATURES. BUT BECAUSE THE SFC LO IS WEAKENING WITH PRES RISES OBSVD OVER THE SFC LO...THE GRADIENT IS WEAKENING STEADILY WITH TIME. SO SW WINDS THIS AFTN ARE NOT AS GUSTY AS YDAY DESPITE DAYTIME HEATING/MIXING. OTRW...THE LOCAL AND UPSTREAM 12Z RAOBS SHOW A RELATIVELY DRY LLVL AIRMASS...SO THERE IS NOTHING MORE THAN PATCHY HI CLDS TO THE SW OF SOME THICKER CLDS IN ONTARIO ASSOCIATED WITH THE LO WELL N OF THE BORDER. THE ONLY EXCEPTION WAS A BIT OF LO CLD THAT DVLPD DOWNWIND OF LK MI NEAR MANISTIQUE WHERE THE SW FLOW OFF THE WATER HAS LIFTED SFC DEWPTS AS HI AS 55 TO 60. WITH A RIBBON OF H85 TEMPS UP TO 15C STREAMING INTO THE WRN CWA IN THE SW FLOW...TEMPS ARE RUNNING WELL ABV NORMAL EARLY THIS AFTN WITH READINGS AS HI AS THE LO 70S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF LK MI. MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH DRY...ACYC SW FLOW ARND SFC HI PRES STRETCHING FM THE NE COAST INTO THE GREAT LKS FCST TO DOMINATE THRU THU. TNGT...EXPECT LO TEMPS TNGT TO FALL A BIT MORE THAN LAST NGT WITH DRY AIR LINGERING UNDER WEAKENING PRES GRADIENT/SW FLOW AS HIER PRES SLOWLY EXPANDS TO THE W. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCENTRAL AND E...CLOSER TO THE WEAKEST GRADIENT/LOWER PWATS AOB 0.5 INCH. WITH THESE IMPROVED RADIATIONAL COOLING CONDITIONS OVER HIER DEWPTS OBSVD THIS AFTN...EXPECT PATCHY FOG IN THESE AREAS. THU...LOOKS LIKE ANOTHER PLEASANT OCT DAY WITH DRY SW FLOW FCST TO DOMINATE AND LEAD TO MOSUNNY CONDITIONS. H85 TEMPS ARE FCST NEAR 14C...ALMOST THE SAME AS TDAY...SO EXPECT MAX TEMPS TO BE SIMILAR TO THIS AFTN. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 239 PM EDT WED OCT 9 2013 AT 00Z FRI...THERE WILL BE AN UPPER RIDGE OVER THE CWA THAT WILL GIVE WAY TO A LOW PRESSURE SYSTEM MOVING FROM NE AT 12Z FRI TO FAR SRN MANITOBA AT 12Z SAT. FRI WILL BE QUIET WITH NO PRECIP EXPECTED DUE TO THE RIDGE BEING OVERHEAD...BUT WITH 850MB TEMPS AROUND 14C...TEMPS WILL BE WELL ABOVE NORMAL WITH HIGHS IN THE 60S AND 70S. AFTER 12Z SAT...MODEL DISAGREEMENT ON THE TIMING/TRACK OF THE SYSTEM IS MORE UNCERTAIN. THE 12Z/09 GFS KEEPS THE LOW MOVING RAPIDLY NNE TO HUDSON BAY BY 00Z SUN...WHILE 00Z/09 ECMWF HANGS THE LOW OVER ONTARIO WHILE WEAKENING...AND FINALLY MOVING TO JAMES BAY AROUND 06Z MON. THE 00Z/09 GEM SOLUTION IS BETWEEN THE GFS AND ECMWF WITH TIMING/TRACK. PRECIP OVER THE CWA FROM THIS SYSTEM WILL MAINLY RESULT FROM THE ASSOCIATED COLD FRONT MOVING THROUGH. OF COURSE...THERE ARE ALSO SOME TIMING DIFFERENCES WITH TIMING OF FROPA. THE GFS MOVES THE FRONT FROM THE WRN U.P. AT 18Z SAT TO THE ERN CWA AROUND 06Z SUN...WITH THE ECMWF BEING AROUND 6 HOURS SLOWER. THE GEM MATCHES UP PRETTY CLOSE TO THE GFS WITH FROPA TIMING. THERE MAY BE SOME SHOWERS OVER THE WRN CWA FRI NIGHT AS THE LOW MOVES TO THE W...BUT OTHERWISE MOST PRECIP WITH THE FRONT SHOULD BE OVER THE CENTRAL AND ERN CWA WHERE THE FRONT WILL INTERACT WITH BETTER INSTABILITY AND MAY BE BACKED UP BY AN UPPER SHORTWAVE TROUGH. WILL NOT GO COMPLETELY DRY OVER THE W...BUT WILL HAVE HIGHEST POPS CENTRAL AND E AND TIMING CLOSER THE GFS/GEM SOLUTIONS. COLDER AIR WILL FILTER IN BEHIND THE SYSTEM...WITH 850MB TEMPS FALLING INTO THE LOW SINGLE DIGITS ABOVE AND MAYBE JUST BELOW ZERO BY LATE SUN/SUN NIGHT. THIS IS WHERE THE MODEL DIFFERENCES BECOME MORE SIGNIFICANT AS THE GFS AND GEM USHER IN DRY HIGH PRESSURE FOR SUN NIGHT WHILE THE ECMWF SOLUTION WITH THE LAGGING LOW WILL KEEP MORE CLOUDS OVERHEAD. WITH THE CLOUDIER ECMWF SOLUTION...LOW TEMPS SUN NIGHT SHOULD FALL INTO THE UPPER 30S TO MID 40S. THE LESS CLOUDY SOLUTIONS WOULD LIKELY RESULT IN A DECENT FREEZE AWAY FROM THE IMMEDIATE SHORES OF THE GREAT LAKES. WILL GO WITH A MIDDLE OF THE ROAD APPROACH AND KEEP CONSENSUS LOW TEMPS FROM THE MID 30S TO MID 40S. THINGS BECOME MORE UNCERTAIN MON THROUGH NEXT WED AS MODELS CONTINUE TO POINT TO A MAJOR PATTERN CHANGE FROM THIS PORTION OF THE COUNTRY. MODELS GENERALLY SHOW MUCH INCREASED UPPER TROUGHING OVER THE ERN HAVE OF THE CONUS...RESULTING IN COLDER TEMPERATURES AND GREATER STRENGTH/FREQUENCY OF SYSTEMS MOVING THROUGH THE REGION. DEFINITELY LOOKS COLDER WITH TEMPS EVEN FALLING TO BELOW NORMAL VALUES. POPS ARE FAR MORE UNCERTAIN AS SYSTEM STRENGTH/TRACK IS FAR FROM CERTAIN. TEMPS DO NOT LOOK QUITE COLD ENOUGH TO ADD MIXED PRECIP TO THE FORECAST...ESPECIALLY GIVEN UNCERTAINTY INVOLVED. USED A CONSENSUS OF MODEL GUIDANCE FOR THIS PORTION OF THE FORECAST PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1208 AM EDT THU OCT 10 2013 DRY HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE TAF SITES THIS FCST PERIOD. THE ONE EXCEPTION MAY BE SAW LATE TONIGHT OR EARLY THU...WHERE SOME FOG COULD DEVELOP. WITH THE LOW LEVEL FLOW MORE SSW COMPARED TO SSE OFF LAKE MI...PROBABILITY OF FOG FORMATION WAS LOW AND NOT INCLUDED IN THE TAF. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 239 PM EDT WED OCT 9 2013 EXPECT S TO SW WINDS UP TO 20 KTS THRU THU NIGHT TO INCREASE TO UP TO 25 KTS ON FRI INTO SAT AS THE PRES GRADIENT TIGHTENS BETWEEN HI PRES OVER THE EASTERN CONUS AND AN APPROACHING COLD FRONT. BEHIND THIS FRONTAL PASSAGE ON SAT...LOOK FOR A WIND SHIFT TO THE W-NW BEFORE WINDS SLOWLY VEER TO THE N BY MON AHEAD OF AN APPROACHING HI PRES CENTER. WINDS WILL BE AS HI AS 20-25 KTS ON SAT NIGHT/SUN FOLLOWING THIS FROPA...BUT THESE WINDS SHOULD DIMINISH UNDER 20 KTS BY MON AS THE HI PRES/WEAKER PRES GRADIENT MOVES NEARBY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...JLB MARINE...KC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
154 AM EDT THU OCT 10 2013 .SYNOPSIS... HIGH PRESSURE OVER THE NORTHEAST UNITED STATES TONIGHT WILL GIVE WAY TO A LOW PRESSURE SYSTEM MOVING UP ALONG THE EAST COAST THURSDAY INTO FRIDAY, BRINGING A CHANCE OF SHOWERS TO THE AREA. THE BEST CHANCE FOR SHOWERS WILL BE ACROSS NORTHEAST PENNSYLVANIA AND THE CATSKILLS. EXPECT TEMPERATURES TO REMAIN ABOVE NORMAL FOR EARLY TO MID OCTOBER INTO THE WEEKEND. && .NEAR TERM /THROUGH TODAY/... 1020 PM UPDATE... FORECAST IN GOOD SHAPE. LATEST HRRR STILL SUPPORTS A DRY OVERNIGHT...WITH A FEW SHOWERS POSSIBLE TOWARD 15Z FAR SOUTH. THIS MATCHES UP WELL WITH THE CURRENT FORECAST SO LITTLE TO CHANGE. ALSO LEFT IN THE MENTION OF PATCHY FOG IN THE VALLEYS. WHILE THE CIRRUS SHIELD IS ALREADY OVERHEAD...IT IS NOT VERY THICK WITH THE STARS STILL VISIBLE. IT TAKES A LOT TO NOT HAVE FOG IN OUR RIVER VALLEYS SO FOR NOW PATCHY FOG LOOKS REASONABLE. THE PREVIOUS AFD IS BELOW... FOR THE REST OF THE AFTERNOON...WE EXPECT TO SEE CONTINUED HIGH LEVEL MOISTURE ADVECTION FROM THE MIDDLE ATLANTIC LOW SUPPORT MORE CIRRUS INTO NY AND PA WHICH WILL THIN OUT AS IT WORKS INTO A REGION OF UPPER LEVEL SUBSDC. THIS SUBSDC WAS SUPPORTG A LL ANTICYCLONE OVER THE NORTHEAST U.S. WITH SUBSBC...850-925 MB TEMPS CONT TO WARM AND WILL BE IN THE LOW TO MID 50S (F) THIS PM. THE SFC LAYER REMAINS FAIRLY DRY WITH DEWPOINTS ONLY THE UPPER 30S AND 40S. THIS COLLABORATES THE MODEL SOUNDING DATA WHICH SUGGEST NO CUMULUS FORMS WITH THE DAY/S HEATING. HENCE ALL WE WILL HAVE IN THE SKY GRIDS IS RELATED TO THINNING CI. CIRRUS WILL BE THICKEST IN NE PA IN CLOSER PROXIMITY TO THE MID ATLANTIC SYSTEM. OTHERWISE A MILD FALL DAY WITH FILTERED SUNSHINE. FOR TONIGHT...WEAK MID ATLANTIC CYCLONE CONTINUES TO SLOWLY WORK NORTHWARD AS PER ALL SYNOPTIC AND MESOSCALE MODEL GUIDC. THIS FEATURE SUPPORTS A FAIRLY STRG LL ERLY JET DUE TO THE STRG HIGH PRESSURE SYSTEM TO THE NE WHICH IS ENHANCING THE PRES GRAD. HENCE WE HAVE A WEAK SFC LOW OFF THE MID ATLANTIC COAST WITH A PRETTY DECENT PRESSURE GRADIENT TO THE NORTH. THIS WILL LEAD TO DECENT MOISTURE ADVECTIONS INTO NE PA BEGINNING LATE TONIGHT...BUT GIVEN THAT THE LOWER AMS BEGINS VERY DRY WE DON/T SEE MUCH IF ANY PRECIP REACHING NE PA B4 12Z THU. SO MID TO HI CLDS WILL STREAM NORTHWARD INTO NE PA AND THIN OUT OVERNGT AS THEY WORK INTO C NY. THERE LIKELY WILL BE VALLEY FOG FORMING IN C NY WHERE MOSTLY CLR SKIES WILL PREDOMINATE AND LIGHT WINDS...BUT IT WON/T BE AS EXTENSIVE AS THIS MORNING/S FOG. BY LATER THU...850 MB JET AS PER GFS...EURO AND CMC MOVES TO THE NORTH OF THIS ADVANCING CYCLONE AND REACHES ACRS ALL OF NE PA/CATSKILLS AND INTO SC NY. THE NAM CONTS TO BE THE ODD MODEL OUT KEEPING THE BEST MOISTURE ADVTNS AND ALL QPF TO THE SOUTH B4 00Z FRI. THINK PRECIP WILL CREEP NORTHWARD AND DRY OUT THU PM BUT SOME LIGHT PRECIP WILL POTENTIALLY REACH INTO NE PA BY LATE THU. THERE IS UNCERTAINTY AS TO HOW FAR N AND W THE PRECIP MAKES IT INTO SC NY THU PM GIVEN THE DRY LL/S SO BASICALLY HAVE DROPPED POPS IN C NY UNTIL THU NGT. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... MID-ATLANTIC CYCLONE SLOWLY WORKS NORTHWARD REACHING OFF THE VA/NC COAST BY 12Z FRI ON THE CMC...EURO AND GFS. THE NAM CONTS TO BE THE OUTLIER WITH THE SFC LOW AND ASSCTD UPPER LOW MUCH FARTHER S ONLY REACHING OFF THE SC COAST AT THE SAME TIME. SINCE THE GFS/EURO AND CMC HAVE BEEN CONSISTENT ALL SHOW SOME LIGHT PRECIP REACHING INTO NE PA AND THE CATSKILLS THU NGT...ESP LATER AT NGT. AS SUCH HAVE GRADUALLY RAMPED POPS UP THU NGT FRM CHC TO LIKELY IN THE POCONOS BTWN 00Z AND 12Z FRI AND FROM BELOW 15 PCT TO CHC MOST OF REST OF CWA AND REACHING UP TO SLGHT CHC IN OUR FAR NW COUNTIES MAINLY ACROSS THE FINGER LAKES TO UPPER MOHAWK THU NGT. FRIDAY THE CYCLONE THEN BEGINS TO PUSH BACK TO THE SOUTH SLOWLY. THIS IS IN RESPONSE TO AN UPPER LEVEL WAVE WHICH DROPS SOUTHWARD ACRS SERN CANADA AND RE-ENFORCES LL HIGH PRESSURE ACRS THE NE U.S AND SERN CANADA IT IS WAKE ON FROM FRI INTO SAT. HENCE POPS PEAK FRI PM FROM SLGHT CHC NW ZONES TO CHC/LIKELY IN THE SERN ZONES. THEN I HAVE POPS TRENDING BACK DOWN FRI NGT THRU SAT AS THE UPPER LEVEL LOW IS PUSHED SOUTHWARD. FOR QPF POTENTIALLY UP TO 1/2 TO 1 INCH WHICH SHUD NOT CAUSE ANY HYDRO ISSUES MAINLY POCONOS-CATSKILLS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... STILL SOME MODEL DISAGREEMENT TO START OUT THE EXTENDED TIME FRAME WITH RESPECT TO POTENTIAL IMPACTS ACROSS OUR REGION FROM CLOSED LOW PRESSURE CENTER PERSISTING OFF THE MID-ATLANTIC COAST. GFS AND CANADIAN-CMC CONTINUE TO SHOW THE FEATURE GRADUALLY DEFLECTING TO THE SOUTH AS WEAK SHORTWAVE RIDGING BUILDS OVER THE NORTHEAST THIS WEEKEND. THE ECMWF ON THE OTHER HAND SHOWS A FURTHER NORTHWARD POSITION WITH POSSIBLE SHWR ACTIVITY PERSISTING ACROSS OUR REGION THROUGH EARLY NEXT WEEK BEFORE A WEAK COLD FRONT MOVES THROUGH THE AREA BY LATE MONDAY/EARLY TUESDAY TIMEFRAME. FOR NOW...WILL ADVERTISE SLGT CHC POPS ACROSS THE FAR SOUTH AND SOUTHEAST AT THE START OF THE PERIOD BEFORE INCREASING POPS REGION WIDE BY MONDAY IN ANTICIPATION OF AFOREMENTIONED FRONT. WX BECOMES A BIT MORE INTERESTING BY TUESDAY/WEDNESDAY AS A STRONG STORM SYSTEM SHIFTING EAST FROM THE CENTRAL/NORTHERN PLANS REGION LIFTS A WARM FRONT NORTH THROUGH THE AREA. FROM THIS VANTAGE POINT...STORM SYSTEM APPEARS FAIRLY WELL SUPPORTED WITH STRONG DYNAMICS ALOFT AND HAVE INCREASED POPS INTO THE CHC CATEGORY BY MIDWEEK BASED ON FAVORABLE AGREEMENT BETWEEN THE ECMWF AND GFS. THAT SAID...SOME DISAGREEMENTS WITH 12Z MODEL SUITE AND FROPA TIMING...HOWEVER INDICATIONS SUGGEST A REGION WIDE RAIN EVENT WILL BE POSSIBLE BY MIDWEEK AS STORM SYSTEM MOVES EAST WITH TIME. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... 140 AM EDT UPDATE... VFR CONDITIONS WITH LIGHT WINDS ARE EXPECTED FOR ALL TAFS THROUGH THE NEXT 24 HOURS EXCEPT FOR KELM. FOG HAS DEVELOPED THIS MORNING AT KELM DESPITE WIDESPREAD COVERAGE OF HIGH CLOUDS ACROSS NEW YORK. AT THE MOMENT DECIDED TO KEEP A TEMPO IN FOR VISBYS WITH BELOW ALTERNATE MINIMUMS THROUGH 10Z. THE FORECAST CHALLENGE OF THE NIGHT IS HOW DENSE WILL THE FOG GET AT KELM. CONFIDENCE IS NOT HIGH THAT IT WILL BECOME AS DENSE AS LAST NIGHT SO LEFT 1SM BR FOR THE TIME BEING. OUTLOOK... THU NGT-MON...VFR WITH THE EXCEPTION OF POTENTIAL VALLEY FOG ACROSS THE TWIN TIERS EACH MORNING OVER THE WEEKEND /MAINLY IMPACTING KELM/. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJN NEAR TERM...DJN/HEDEN SHORT TERM...DJN LONG TERM...CMG AVIATION...KAH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
225 AM CDT THU OCT 10 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM CDT THU OCT 10 2013 NO FORECAST CONCERNS FOR THE SHORT TERM PERIOD WITH QUIET WEATHER CONTINUING. CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A NORTHERN STREAM UPPER TROUGH CROSSING BRITISH COLUMBIA...A DEEP UPPER LOW/TROUGH OVER SOUTHERN CALIFORNIA...AND STRONG RIDGING FROM EASTERN TEXAS THROUGH THE EASTERN GREAT LAKES. VERY LITTLE CLOUD COVER TO SPEAK OF FROM THE CENTRAL PLAINS INTO THE FORECAST AREA... EXCEPT FOR A BAND OF CIRRUS ASSOCIATED WITH A SHORTWAVE LIFTING THROUGH WESTERN IA. THE LACK OF CLOUD COVER IS A RESULT OF PLENTIFUL DRY AIR SEEN ON 00Z SOUNDINGS FROM GRB...DVN...MPX...OAX AND DDC. AT THE SURFACE...LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO WHILE HIGH PRESSURE WAS PRESENT OVER LOWER MICHIGAN. THE PRESSURE GRADIENT BETWEEN THESE FEATURES OVER THE FORECAST AREA IS LIGHTER THAN THIS TIME YESTERDAY...RESULTING IN LIGHTER WINDS AND THEREFORE COOLER TEMPERATURES. THE TYPICAL WISCONSIN COLD SPOTS HAVE DROPPED INTO THE UPPER 30S...MEANWHILE HIGHER TERRAIN SITES ALONG AND WEST OF THE MISSISSIPPI RIVER WHICH ARE EXPERIENCING MORE WIND ARE IN THE LOW TO MID 50S. AIRMASS REMAINS ABNORMALLY WARM... THOUGH...WITH 00Z SOUNDINGS SHOWING 925MB TEMPERATURES OF 15-17C EAST TO WEST. THE DRY CONDITIONS WILL CONTINUE FOR ANOTHER 24 HOURS AS THE FORECAST AREA REMAINS SITUATED IN A BLOCKED UPPER LEVEL PATTERN. THAT PATTERN FEATURES THE UPPER LOW IN SOUTHERN CALIFORNIA PROGGED TO EJECT NORTHEASTWARD TOWARDS THE BLACK HILLS OF SOUTH DAKOTA BY 12Z FRIDAY...WHILE STRONG RIDGING HOLDS IN PLACE OVER LOWER MICHIGAN. EXPECT WINDS TO INCREASE...A RESULT OF THE PRESSURE GRADIENT TIGHTENING AHEAD OF THE DEEPENING SURFACE LOW IN COLORADO LIFTING NORTH WITH THE UPPER LOW. THE STRONGER SOUTHERLY WINDS DO NOT BRING ANY WARMER AIR IN FOR TODAY AT 925MB...AS MODEL FORECASTS SUGGESTS 925MB TEMPERATURES END UP AGAIN BETWEEN 16-18C AT 00Z. THUS HIGHS ARE LIKELY TO BE SIMILAR TO THOSE SEEN YESTERDAY. HOWEVER... THE WINDS WILL HELP TO KEEP THE NEAR SURFACE LAYER MORE MIXED TONIGHT...RESULTING IN A WARMER NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 225 AM CDT THU OCT 10 2013 FORECAST CONCERNS ARE ON WINDS FRIDAY...PRECIPITATION CHANCES LATE FRIDAY THROUGH SATURDAY...AND PRECIPITATION CHANCES AGAIN EARLY NEXT WEEK. SYNOPTIC OVERVIEW... MODELS ARE IN GOOD AGREEMENT THAT THE UPPER AND SURFACE LOWS OVER WESTERN SOUTH DAKOTA FRIDAY MORNING WILL CONTINUE LIFTING NORTH-NORTHEAST...AND BEGIN PHASING FRIDAY NIGHT WITH THE NORTHERN STREAM TROUGH CURRENTLY OVER BRITISH MARCHING EAST. AS THIS PHASING OCCURS...THE SYSTEMS COLD FRONT LOOKS PROGGED TO MOVE THROUGH THE FORECAST AREA LATE FRIDAY NIGHT INTO SATURDAY. ANOTHER SHORTWAVE TROUGH LOOKS TO MOVE INTO THE AREA LATE SATURDAY BUT LITTLE IMPACT IS SUGGESTED WITH IT. ATTENTION THEN FOCUSES BACK WEST AS ANOTHER DEEP UPPER TROUGH IS PROGGED TO DEVELOP OVER THE WESTERN U.S.. ECMWF/GFS/CANADIAN AND THEIR RESPECTIVE ENSEMBLES ARE COMING INTO BETTER AGREEMENT OF THIS UPPER TROUGH EJECTING EASTWARD SLOWLY TOWARDS THE FORECAST AREA MONDAY NIGHT THROUGH WEDNESDAY. A RELATIVELY STRONG SURFACE SYSTEM LOOKS TO ACCOMPANY THIS TROUGH...SETTING UP A GOOD CHANCE OF RAIN DURING THIS PERIOD...ESPECIALLY MONDAY NIGHT AND TUESDAY. DETAILS... WINDS ON FRIDAY REMAIN IN FOCUS AS A TIGHT PRESSURE GRADIENT IS FORECAST OVER THE AREA AHEAD OF THE DAKOTAS LOW. THE BEST JUXTAPOSITION OF HIGHEST PRESSURE GRADIENT MAGNITUDE AND MIXING APPEARS TO OCCUR OVER SOUTHEAST MN. MOMENTUM TRANSFER FROM SOUNDINGS SUGGEST GUSTS OVER THE HIGHER TERRAIN OF SOUTHEAST MN OF 35 KT...AND PERHAPS BRIEFLY UP TO 40 KT. THUS...THE CONCERN FOR A MARGINAL WIND ADVISORY PERSISTS. ELSEWHERE...GUSTS OF 25-30 KT SEEM REASONABLE. THESE WINDS OUT OF THE SOUTH HELP TO ADVECT IN 925MB TEMPS OF 16-18C...ALLOWING HIGH TEMPERATURES TO END UP SLIGHTLY WARMER THAN TODAY. NEXT CONCERN IS ON PRECIPITATION CHANCES. A WARM CONVEYOR BELT OF PRECIPITATION AHEAD OF THE LOW SHOULD BE LIFTING THROUGH WESTERN PORTIONS OF IOWA AND MINNESOTA FRIDAY MORNING. ALL INDICATIONS... MINUS THE 10.00Z ECMWF...ARE THAT THIS BELT OF PRECIPITATION WILL FALL APART AS IT PUSHES TOWARDS THE FORECAST AREA FRIDAY AFTERNOON...RESULTING FROM RUNNING INTO DRIER AIR AND THE DYNAMIC FORCING LIFTING NORTH. THE ECMWF HOLDS PRECIPITATION TOGETHER TO AFFECT SOUTHEAST MN AND NORTHEAST IA. FOR NOW HAVE KEPT FRIDAY MOSTLY DRY FROM THE PREVIOUS FORECAST...BUT INTRODUCED A SPRINKLES MENTION. AN INCREASE IN CLOUDS IS LIKELY LATER IN THE DAY NO MATTER WHAT. THERE IS GOOD MODEL AGREEMENT FRIDAY NIGHT AND ESPECIALLY ON SATURDAY THAT A BAND OF SHOWERS WILL FORM AROUND THE COLD FRONT MARCHING EAST. THIS PRECIPITATION IS A RESULT OF MID LEVEL FRONTOGENESIS FORCING AND A STREAM OF 1-1.3 INCH PRECIPITABLE WATER VALUES ADVECTING NORTH PROVIDING MOISTURE. THE FORECAST PROBLEM IS WHERE THE PRECIPITATION ENDS UP AS MODELS DIFFER ON FRONTAL TIMING. TIMING OF THE FRONT TO GET THROUGH THE ENTIRE AREA VARIES FROM 12Z SATURDAY ACCORDING TO THE 10.00Z NAM...15Z SATURDAY FROM THE 10.00Z GFS...18Z SATURDAY FROM THE 10.00Z CANADIAN/ECMWF AND ABOUT 21Z SATURDAY FROM THE 10.00Z UKMET/09.12Z ECMWF. IF THE FRONT ENDS UP SLOWER...THE GREATER THE CHANCE AT LEAST THE SOUTHEAST HALF OF THE FORECAST AREA WILL SEE RAIN. FOR NOW...HAVE STAYED WITH A CONSENSUS APPROACH WHICH RESULTS IN MAXIMUM CHANCES IN THE 30-35 PERCENT RANGE. TEMPERATURES DEFINITELY LOOK COOLER FOR THE WEEKEND AS 925MB READINGS FALL TO 10-13C ON SATURDAY AND 8-10C ON SUNDAY. DRY CONDITIONS ARE LIKELY SATURDAY NIGHT THROUGH AT LEAST MONDAY MORNING AS THE AREA IS UNDER THE INFLUENCE OF HIGH PRESSURE. ATTENTION THEN TURNS TO THE UPPER TROUGH AND LOW PRESSURE SYSTEM COMING OUT OF THE WESTERN U.S. AND PLAINS. PRECIPITABLE WATER VALUES AGAIN CLIMB TO 1-1.3 INCHES OR UP TO 200 PERCENT OF NORMAL AHEAD OF THE SYSTEM. THE COMBINATION OF THIS MOISTURE...FRONTOGENETICAL AND DPVA FORCING WILL ALL COMBINE TO SPREAD PRECIPITATION ACROSS THE UPPER MIDWEST WITH THIS SYSTEM. MODEL TIMING OF THIS PRECIPITATION TO AFFECT THE FORECAST AREA IS REALLY CENTERING ON MONDAY NIGHT AND TUESDAY...THUS HAVE RAISED PRECIPITATION CHANCES CONSIDERABLY FOR THIS TIME PERIOD. MUCAPE IS ALMOST NIL WITH THE SYSTEM...RESULTING FROM NEARLY MOIST-ADIABATIC LAPSE RATES...THUS HAVE KEPT THE MENTION OF THUNDER OUT OF THE FORECAST. THE FORECAST AREA LOOKS TO BECOME AFFECTED BY THE COLD CONVEYOR BELT OF THE SYSTEM TUESDAY NIGHT AND WEDNESDAY...RESULTING IN THE NEED TO CARRY 30-50 PERCENT CHANCES. THESE MAY NEED TO BE RAISED LATER AS THE SYSTEM TRACK FIRMS UP. THERMAL FIELDS ARE WARM ENOUGH TO KEEP THE PRECIPITATION TYPE AS RAIN...BUT WITH 925MB TEMPS DROPPING TO 3-6C ON WEDNESDAY...IT IS GOING TO FEEL MUCH COLDER THAN WHAT WE HAVE SEEN AS OF LATE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1141 PM CDT WED OCT 9 2013 THE MAIN FOCUS FOR THE TAF SITES IS ON LOW CHANCES FOR RIVER VALLEY FOG AT LSE FOLLOWED BY HOW STRONG WINDS WILL BE THURSDAY. SURFACE WINDS HAVE DROPPED OFF IN THE VALLEY WITH LSE AT 4-6KTS THOUGH WINDS JUST ABOVE IT ARE STILL BLOWING AT 10-20KTS. IT DOES NOT LOOK LIKE AN OVERLY FAVORABLE SETUP FOR VALLEY FOG...BUT THERE IS AN OUTSIDE CHANCE THAT SOMETHING COULD FORM ALONG THE LA CROSSE RIVER VALLEY AND DRAIN TO THE WEST TOWARD THE AIRPORT. OTHERWISE...WINDS WILL PICK UP THURSDAY MORNING WITH SOME GUSTS IN THE 16-20KT RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1155 PM CDT WED OCT 9 2013 .UPDATE... && .AVIATION/06Z TAFS/... LIGHTER WIND REGIME IN THE BOUNDARY LEVEL TONIGHT SO SOME CONCERN FOR FOG IN THE EASTERN INLAND AREAS...POTENTIALLY AFFECTING THE KENW/KUES CORRIDOR. SREF PROBS WERE LOW BUT THE HRRR BRINGS VSBYS DOWN TO 1/4 MILE FROM SOUTH OF SHEBOYGAN TO KENOSHA. WILL INCLUDE SOME FOG BUT NOT GO QUITE AS WIDESPREAD AS THE HRRR SHOWS. THE DENSE LIFR FOG WOULD LIKELY BE IN THE TYPICAL LOW AREA/RIVER VALLEYS UNTIL 13Z. OTHERWISE MOSTLY CLEAR SKIES WITH ONLY SOME SCATTERED CIRRUS. && .PREV DISCUSSION... /ISSUED 306 PM CDT WED OCT 9 2013/ TONIGHT AND THURSDAY - CONFIDENCE...HIGH QUIET WEATHER CONTINUES. HIGH PRESSURE REMAINS ACROSS THE EASTERN U.S. WITH A NEARLY STATIONARY TROUGH OF LOW PRESSURE IN THE PLAINS. THE SOUTHERLY FLOW PERSISTS WITH AN ONSHORE FLOW AS WELL. AIRMASS REMAINS DRY WITH ONLY A BIT OF CIRRUS. 925 TEMPS SUPPORT MORE IN THE WAY OF ABOVE NORMAL TEMPERATURES. THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE IS HIGH. HIGH PRESSURE EXITS TO THE EAST WHILE STRONG LOW PRESSURE MOVES FROM THE HIGH PLAINS OF ERN COLORADO...NORTHEAST TO EASTERN NORTH DAKOTA BY FRIDAY EVENING. THE TIGHTENING PRESSURE GRADIENT WILL BRING BREEZY SOUTHERLY WINDS TO SOUTHERN WISCONSIN BY FRIDAY AFTERNOON. GUSTS COULD REACH 30 MPH WEST OF MADISON...LOWER IN THE EAST. THE STRONGEST WINDS JUST OFF THE SURFACE ARRIVE FRIDAY EVENING...BUT WE DECOUPLE WITH SUNSET WHICH WILL LIMIT WIND SPEEDS. OTHERWISE...STILL DRY AND WARM FOR MID OCTOBER. FRIDAY NIGHT AND SATURDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. A COLD FRONT ASSOCIATED WITH THE LOW TRACKING NORTH INTO CANADA WILL SWEEP THROUGH ON SATURDAY. SHOWERS ALONG AND AHEAD OF IT COULD ARRIVE IN THE WEST AFTER MIDNIGHT FRIDAY NIGHT. THE MODELS ARE IN BETTER AGREEMENT WITH TIMING. THERE IS A SECONDARY MID LEVEL SHORT WAVE THAT SWINGS NORTHEAST INTO THE AREA ON SATURDAY...ENHANCING THE FROTOGENESIS AND OMEGA WITH THE FRONT. IN ADDITION...ALTHOUGH MOISTURE WILL BE LACKING WITH THE FRONT WHEN IT IS UPSTREAM...WE SHOULD SEE A RIBBON OF HIGHER DEWPOINTS MOVE INTO THE AREA. ALL THIS LOOKS TO COME TOGETHER ACROSS THE AREA ON SATURDAY...SO WILL MAINTAIN HIGH CHC POPS FOR NOW...AND IF CONFIDENCE INCREASES...THOSE POPS WILL RISE. THERE IS SOME CAPE...BUT NOT IMPRESSIVE...SO WILL MAINTAIN JUST A SLIGHT CHANCE OF STORMS. LOOKING AT TIMING...AREAS WEST OF MADISON MAY BE CLEARING OUT BY AFTERNOON WITH THE RAIN ENDING BY EARLY EVENING IN THE EAST. SUNDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM TO HIGH. COOLER HIGH PRESSURE ARRIVES IN THE WAKE OF THE LOW WITH TEMPERATURES FALLING BACK TO LEVELS MORE NORMAL FOR THE TIME OF YEAR. TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM. A NICE MEATY SYNOPTIC SYSTEM IS EXPECTED TO COME THROUGH DURING THIS PERIOD. IT/S STARTING TO LOOK MORE FALL-LIKE WITH THESE TYPES OF SYSTEMS SPINNING THROUGH. THE GFS AND ECMWF WERE AT ODDS ON TIMING OVER THE LAST FEW RUNS...BUT HAVE COME INTO SYNC WITH BOTH THE TIMING AND THE GENERAL TRACK OF THE LOW. RAIN SHOULD MOVE LATE MONDAY NIGHT AND CONTINUE INTO WEDNESDAY MORNING. THE HEAVIEST RAIN LOOKS TO BE TUESDAY AFTERNOON AND EVENING. NO FEAR OF ANY SNOW FLAKES AS TEMPERATURES WILL BE TOO WARM. THEN EVEN COOLER TEMPERATURES ARRIVE LATE NEXT WEEK. AVIATION/00Z TAFS/...VFR MOSTLY SKC THIS PERIOD. LIGHTER WIND REGIME OFF THE DECK TONIGHT SO SOME CONCERN FOR FOG IN THE EASTERN INLAND AREAS...POTENTIALLY AFFECTING THE KENW/KUES CORRIDOR. SREF PROBS ARE VERY LOW. SO FOR NOW WILL INCLUDE SOME FOG BUT NOT GO QUITE AS LOW AS MOS SUGGESTS AT THIS POINT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...HENTZ TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR THURSDAY NIGHT THROUGH WEDNESDAY...DAVIS
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
850 AM MST THU OCT 10 2013 && .SYNOPSIS... A STRONG UPPER LEVEL STORM SYSTEM WILL QUICKLY MOVE THROUGH THE AREA TODAY...RESULTING IN SCATTERED SHOWERS THIS MORNING AND SUBSTANTIALLY COOLER THAN NORMAL TEMPERATURES BY THIS AFTERNOON. DRY CONDITIONS WITH A SLOW WARMING TREND IS EXPECTED TO BEGIN ON FRIDAY...THEN CONTINUE INTO EARLY NEXT WEEK. && .DISCUSSION... THE UPPER LOW THAT HAS BROUGHT OUR CWA MUCH COOLER TEMPERATURES...AND SOME LIGHT RAIN...IS NOW CENTERED JUST WEST OF FLAGSTAFF. THIS LOW IS STILL FORECAST TO MOVE NORTHEASTWARD INTO EXTREME NORTHWEST NEW MEXICO/SOUTHWEST COLORADO BY LATE THIS AFTERNOON. THE SURFACE COLD FRONT HAS NOW MOVED INTO EASTERN ARIZONA WITH MOST OF ITS ASSOCIATED SHOWER ACTIVITY NOW CONFINED TO EXTREME EASTERN MARICOPA COUNTY AND POINTS EAST. SKIES SHOULD BEGIN TO CLEAR OVER THE PHOENIX AREA OVER THE NEXT HOUR OR TWO...WITH MOSTLY SUNNY SKIES EXPECTED BY LATE AFTERNOON. PRECIP AMOUNT ACROSS THE GREATER PHOENIX AREA HAVE BEEN ON THE LIGHT SIDE...MAINLY 0.05 INCH OR LESS...WITH ISOLATED AREAS IN NORTH PHOENIX SEEING AS MUCH AS 0.10 OF AN INCH. OTHER THAN SOME ADJUSTMENTS IN SHORT-TERM TEMPERATURE TRENDS...CURRENT GRIDDED FORECASTS ARE LOOKING QUITE GOOD...NO UPDATES ARE PLANNED AT THIS TIME. && .PREVIOUS DISCUSSION... UPPER LEVEL LOW PRESSURE CONTINUES TO MOVE THROUGH THE AREA THIS MORNING. REGIONAL RADAR MOSAIC INDICATES SHOWERS DEVELOPING ACROSS THE PHOENIX AREA...HOWEVER THE BACK EDGE OF THE BROKEN BAND OF RAINFALL IS ALREADY EXITING SOUTHEAST CALIFORNIA. BASED ON CURRENT TRENDS...I WOULD EXPECT PRECIP TO BEGIN CLEARING OUT OF THE PHOENIX AREA BY MID MORNING /15Z OR SO/...WITH CLEARING SKIES AND DRY CONDITIONS ACROSS THE ENTIRE FORECAST AREA BY MID AFTERNOON. THIS THINKING IS IN LINE WITH PREVIOUS FORECASTS AND CONFIRMED BY THIS MORNINGS 00Z MODEL DATA...AS WELL AS THE LATEST HRRR AND HI-RES SUITE OF WRF MODELS. INHERITED FORECAST WAS ONLY MODIFIED SLIGHTLY TO INCREASE POPS ACROSS THE PHOENIX AREA TO AROUND 40 PERCENT AND TO AROUND 90 PERCENT IN THE MOUNTAINS EAST OF THE METRO. RAINFALL TOTALS HAVE BEEN VERY LIGHT SO FAR...ONLY A FEW HUNDREDTHS OBSERVED ACROSS SOUTHEAST CALIFORNIA AND ONLY A TRACE AT YUMA. HAD THESE VALUES BEEN HIGHER I WOULD CONTEMPLATE MUCH HIGHER POPS ACROSS THE METRO BUT THIS IS SHAPING UP TO BE A WIDESPREAD BUT SHORT LIVED SPOTTY LIGHT RAIN EVENT. AS HAS ALSO BEEN ADVERTISED...THE MOST NOTEWORTHY EFFECT WILL BE SUBSTANTIALLY COOLER TEMPERATURES THIS AFTERNOON. MOST DESERT LOCALES WILL ONLY TOP OUT IN THE LOWER 70S THIS AFTERNOON...ABOUT 15-20 DEGREES BELOW NORMAL FOR OCT 10. THE FORECAST TURNS VERY TRANQUIL ACROSS THE LOWER DESERTS FROM FRIDAY ONWARD AS BROAD NORTHWESTERLY FLOW ESTABLISHES ITSELF ACROSS THE AREA. THIS WILL RESULT IN DRY WEATHER WITH A GRADUAL WARMING TREND THROUGH NEXT WEEK. THE EUROPEAN AND GFS...ALONG WITH THEIR RESPECTIVE ENSEMBLES...INDICATE A LOW MOVING THROUGH NORTHERN ARIZONA LATE THIS WEEKEND WITH A SECONDARY SHORTWAVE TROUGH SWEEPING THROUGH EARLY NEXT WEEK. AT THIS POINT IT WOULD APPEAR ANY IMPACTS THIS FAR SOUTH SHOULD BE MINIMAL/NEGLIGIBLE FOR A COUPLE OF REASONS. THE PROLONGED OVER-LAND TRAJECTORY OF THE LOW WILL RESULT IN EXTREMELY LOW PWATS /ONLY 0.5-0.6 INCHES/ AS THE TROUGH MOVES THROUGH THIS WEEKEND AS WELL AS WITH THE SECONDARY SHORTWAVE. SECOND...THE BEST ISENTROPIC LIFT IS DISPLACED WELL TO THE NORTH OF THE AREA...MORE INTO THE FOUR CORNERS AREA THAN SOUTH-CENTRAL ARIZONA. PERHAPS A SUBTLE INCREASE IN WINDS WITH THE TROUGHS BUT NOTHING OF ANY SIGNIFICANCE. AS MENTIONED BEFORE...TEMPS WILL GRADUALLY RETURN TO NORMAL BY MID WEEK. HIGHS IN THE UPPER 80S WILL BE COMMON ACROSS THE DESERTS ALONG WITH LOWS IN THE LOWER 60S. && .AVIATION... SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL... SURFACE COLD FRONT WILL WORK EASTWARD ACROSS THE CENTRAL DESERTS THIS MORNING...LOWERING CIGS GENLY INTO THE 5-7K RANGE. ISOLD CIGS DOWN TO AROUND 4K ARE POSSIBLE WITH MODERATE SHOWERS. EXPECT CLEARING BY LATE MORNING...16-18Z...AS FRONT MOVES OFF TO THE EAST AND A DRIER MORE SUBSIDENT AIRMASS MOVES IN. FEW-SCT CU WILL PERSIST THRU THE AFTERNOON THEN DISSIPATE AROUND SUNSET. WINDS TO FAVOR THE WEST THRU THE EVENING HOURS TODAY GENLY 15KT OR LESS...AND MAY BRIEFLY BACK AROUND TO THE SOUTHEAST EARLY THIS MORNING AHEAD OF THE APPROACHING FRONT. AS THE FRONT PASSES...LIGHT TO MODERATE SHOWERS WILL DOMINATE... CANNOT RULE OUT AN ISOLD THUNDERSTORM BUT THIS IDEA WILL NOT BE MENTIONED IN THE TAFS DUE TO LOW PROBABILITY. SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH... EXPECT CLEARING FROM THE WEST THIS MORNING AS A SURFACE COLD FRONT MOVES EAST OF THE AREA AND INTO THE CENTRAL AZ DESERTS. FEW-SCT CU WITH BASES 6-9K FEET ARE EXPECTED THIS MORNING INTO THE AFTN HOURS WITH SKIES BECOMING GENLY CLEAR BY SUNSET. WINDS TO FAVOR THE SOUTHWEST TO WEST NEXT 24 HOURS WITH SPEEDS MOSTLY 15KT OR LESS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... CYCLONIC FLOW WILL PREDOMINATE ACROSS THE INTERMOUNTAIN WEST...RESULTING IN A PERSISTENT WESTERLY FLOW ALONG WITH A DRYING TREND ACROSS THE REGION. MINIMUM HUMIDITIES WILL GENERALLY RANGE FROM THE LOW TO MID TEENS THROUGH THE WEEKEND...LOWERING A FEW PERCENT BY EARLY NEXT WEEK. TEMPERATURES WILL WARM THROUGH THE WEEKEND BEFORE LEVELING OFF NEXT WEEK TO NEAR OR SLIGHTLY BELOW NORMAL READINGS. THERE IS THE POTENTIAL FOR GUSTY NORTH WINDS DOWN THE LOWER COLORADO RIVER VALLEY EARLY NEXT WEEK BUT DUE TO LOWER CONFIDENCE...WILL KEEP VALUES CLOSER TO CLIMATOLOGICAL NORMALS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/LEINS AVIATION....CB FIRE WEATHER...CB/HIRSCH
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
325 AM MST THU OCT 10 2013 .UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS. && .SYNOPSIS... A STRONG UPPER LEVEL STORM SYSTEM WILL QUICKLY MOVE THROUGH THE AREA TODAY...RESULTING IN SCATTERED SHOWERS THIS MORNING AND SUBSTANTIALLY COOLER THAN NORMAL TEMPERATURES BY THIS AFTERNOON. DRY CONDITIONS WITH A SLOW WARMING TREND IS EXPECTED TO BEGIN ON FRIDAY...THEN CONTINUE INTO EARLY NEXT WEEK. && .DISCUSSION... UPPER LEVEL LOW PRESSURE CONTINUES TO MOVE THROUGH THE AREA THIS MORNING. REGIONAL RADAR MOSAIC INDICATES SHOWERS DEVELOPING ACROSS THE PHOENIX AREA...HOWEVER THE BACK EDGE OF THE BROKEN BAND OF RAINFALL IS ALREADY EXITING SOUTHEAST CALIFORNIA. BASED ON CURRENT TRENDS...I WOULD EXPECT PRECIP TO BEGIN CLEARING OUT OF THE PHOENIX AREA BY MID MORNING /15Z OR SO/...WITH CLEARING SKIES AND DRY CONDITIONS ACROSS THE ENTIRE FORECAST AREA BY MID AFTERNOON. THIS THINKING IS IN LINE WITH PREVIOUS FORECASTS AND CONFIRMED BY THIS MORNINGS 00Z MODEL DATA...AS WELL AS THE LATEST HRRR AND HI-RES SUITE OF WRF MODELS. INHERITED FORECAST WAS ONLY MODIFIED SLIGHTLY TO INCREASE POPS ACROSS THE PHOENIX AREA TO AROUND 40 PERCENT AND TO AROUND 90 PERCENT IN THE MOUNTAINS EAST OF THE METRO. RAINFALL TOTALS HAVE BEEN VERY LIGHT SO FAR...ONLY A FEW HUNDREDTHS OBSERVED ACROSS SOUTHEAST CALIFORNIA AND ONLY A TRACE AT YUMA. HAD THESE VALUES BEEN HIGHER I WOULD CONTEMPLATE MUCH HIGHER POPS ACROSS THE METRO BUT THIS IS SHAPING UP TO BE A WIDESPREAD BUT SHORT LIVED SPOTTY LIGHT RAIN EVENT. AS HAS ALSO BEEN ADVERTISED...THE MOST NOTEWORTHY EFFECT WILL BE SUBSTANTIALLY COOLER TEMPERATURES THIS AFTERNOON. MOST DESERT LOCALES WILL ONLY TOP OUT IN THE LOWER 70S THIS AFTERNOON...ABOUT 15-20 DEGREES BELOW NORMAL FOR OCT 10. THE FORECAST TURNS VERY TRANQUIL ACROSS THE LOWER DESERTS FROM FRIDAY ONWARD AS BROAD NORTHWESTERLY FLOW ESTABLISHES ITSELF ACROSS THE AREA. THIS WILL RESULT IN DRY WEATHER WITH A GRADUAL WARMING TREND THROUGH NEXT WEEK. THE EUROPEAN AND GFS...ALONG WITH THEIR RESPECTIVE ENSEMBLES...INDICATE A LOW MOVING THROUGH NORTHERN ARIZONA LATE THIS WEEKEND WITH A SECONDARY SHORTWAVE TROUGH SWEEPING THROUGH EARLY NEXT WEEK. AT THIS POINT IT WOULD APPEAR ANY IMPACTS THIS FAR SOUTH SHOULD BE MINIMAL/NEGLIGIBLE FOR A COUPLE OF REASONS. THE PROLONGED OVER-LAND TRAJECTORY OF THE LOW WILL RESULT IN EXTREMELY LOW PWATS /ONLY 0.5-0.6 INCHES/ AS THE TROUGH MOVES THROUGH THIS WEEKEND AS WELL AS WITH THE SECONDARY SHORTWAVE. SECOND...THE BEST ISENTROPIC LIFT IS DISPLACED WELL TO THE NORTH OF THE AREA...MORE INTO THE FOUR CORNERS AREA THAN SOUTH-CENTRAL ARIZONA. PERHAPS A SUBTLE INCREASE IN WINDS WITH THE TROUGHS BUT NOTHING OF ANY SIGNIFICANCE. AS MENTIONED BEFORE...TEMPS WILL GRADUALLY RETURN TO NORMAL BY MID WEEK. HIGHS IN THE UPPER 80S WILL BE COMMON ACROSS THE DESERTS ALONG WITH LOWS IN THE LOWER 60S. && .AVIATION... SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL... SURFACE COLD FRONT WILL WORK EASTWARD ACROSS THE CENTRAL DESERTS THIS MORNING...LOWERING CIGS GENLY INTO THE 5-7K RANGE. ISOLD CIGS DOWN TO AROUND 4K ARE POSSIBLE WITH MODERATE SHOWERS. EXPECT CLEARING BY LATE MORNING...16-18Z...AS FRONT MOVES OFF TO THE EAST AND A DRIER MORE SUBSIDENT AIRMASS MOVES IN. FEW-SCT CU WILL PERSIST THRU THE AFTERNOON THEN DISSIPATE AROUND SUNSET. WINDS TO FAVOR THE WEST THRU THE EVENING HOURS TODAY GENLY 15KT OR LESS...AND MAY BRIEFLY BACK AROUND TO THE SOUTHEAST EARLY THIS MORNING AHEAD OF THE APPROACHING FRONT. AS THE FRONT PASSES...LIGHT TO MODERATE SHOWERS WILL DOMINATE... CANNOT RULE OUT AN ISOLD THUNDERSTORM BUT THIS IDEA WILL NOT BE MENTIONED IN THE TAFS DUE TO LOW PROBABILITY. SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH... EXPECT CLEARING FROM THE WEST THIS MORNING AS A SURFACE COLD FRONT MOVES EAST OF THE AREA AND INTO THE CENTRAL AZ DESERTS. FEW-SCT CU WITH BASES 6-9K FEET ARE EXPECTED THIS MORNING INTO THE AFTN HOURS WITH SKIES BECOMING GENLY CLEAR BY SUNSET. WINDS TO FAVOR THE SOUTHWEST TO WEST NEXT 24 HOURS WITH SPEEDS MOSTLY 15KT OR LESS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... CYCLONIC FLOW WILL PREDOMINATE ACROSS THE INTERMOUNTAIN WEST...RESULTING IN A PERSISTENT WESTERLY FLOW ALONG WITH A DRYING TREND ACROSS THE REGION. MINIMUM HUMIDITIES WILL GENERALLY RANGE FROM THE LOW TO MID TEENS THROUGH THE WEEKEND...LOWERING A FEW PERCENT BY EARLY NEXT WEEK. TEMPERATURES WILL WARM THROUGH THE WEEKEND BEFORE LEVELING OFF NEXT WEEK TO NEAR OR SLIGHTLY BELOW NORMAL READINGS. THERE IS THE POTENTIAL FOR GUSTY NORTH WINDS DOWN THE LOWER COLORADO RIVER VALLEY EARLY NEXT WEEK BUT DUE TO LOWER CONFIDENCE...WILL KEEP VALUES CLOSER TO CLIMATOLOGICAL NORMALS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...LEINS AVIATION....CB FIRE WEATHER...CB/HIRSCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
942 AM MDT THU OCT 10 2013 .UPDATE... && .SHORT TERM...UPPER LOW NOW MOVING EAST AND NORTHEAST ACROSS WESTERN ARIZONA WITH GOOD PRECIP NOW OCCURRING OVER WESTERN COLORADO. NORTH CENTRAL MOUNTAINS UNDER A STRONG SOUTH AND SOUTHEAST MOUNTAIN TOP FLOW SO SEEING SOME STRONG WINDS ON MTN TOP SENSORS IN THE 30 TO 50 MPH RANGE. THIS FLOW NOT GOOD FOR PRECIP PRODUCTION AND HAVE LOWER POPS THIS AM FOR THE MOUNTAINS. AS THE UPPER LOW NEARS COLORADO THIS AFTERNOON EXPECT INCREASING SHOWERS IN THE MOUNTAINS WITH STRONG QG ASCENT. A MORE TRICKY FORECAST OVER NORTHEAST COLORADO WITH THE STRONG ASCENT FIGHTING THE DEVELOPING SOUTHERLY DOWNSLOPE FLOW OVER THE FRONT RANGE. LOWER POPS IN ORDER HERE BUT STILL EXPECT SOME STRONG SOUTHERLY WINDS TO DEVELOP WITH BETTER MIXING. ANY SHOWERS THAT DO DEVELOP WITH BE ABLE TO TRANSFER THOSE STRONGER WINDS TO THE SURFACE. FURTHER EAST...STILL A CHANCE FOR SEVERE STORMS AHEAD OF THE SURFACE TROF WITH HIGH WINDS THE BIGGEST THREAT. CAPES NOT ALL THAT IMPRESSIVE WITH ANYWHERE FROM 500 TO 1000J/KG AND GOOD SHEAR TO KEEP THE THREAT GOING. AS FOR CURRENT HILITESS...ADVISORY FOR MOUNTAINS LOOK GOOD ESPECIALLY FOR TONIGHT AS OROGRAPHIC FLOW INCREASES. HIGH WINDS LOOK MORE IFFY ESPECIALLY OVER LOWER FOOTHILLS AND ADJACENT PLAINS. WILL LOOK MORE AT THAT FOR AFTERNOON PACKAGE. .AVIATION...LIGHT AND VARIABLE WINDS THIS MORNING WITH SURFACE LOW OVER DENVER. SATELLITE IMAGERY SHOWING CLEARING MOVING IN FROM THE SOUTH...WHICH WILL ALLOW FOR BETTER MIXING BY EARLY THIS AFTERNOON AS STRONG SOUTHERLY WINDS DEVELOP AT APA AND DENVER. WEST OF THE SURFACE LOW WINDS WILL BE MORE NORTHERLY AND LIGHTER AT BJC. STILL UNCLEAR ON THE PRECIP SIDE OF THINGS ON AREAL EXTENT OF SHOWERS. STILL PLAY A LOW COVERAGE OF TS BUT GREATER CHANCE OF WINDS AS PORTRAYED IN CURRENT TAFS. ONLY MINOR CHANGES TO TIMING AND WINDS EXPECTED FOR 18Z ISSUANCES. && .PREV DISCUSSION... /ISSUED 259 AM MDT THU OCT 10 2013/ SHORT TERM...RATHER STG SYSTEM OVER SRN CALIFORNIA EARLY THIS MORNING WILL MOVE RAPIDLY ENE INTO WRN COLORADO BY THIS AFTN AND THEN INTO NERN CO OVERNIGHT. MOISTURE WILL CONTINUE TO INCREASE IN THE MTNS WITH PCPN BECOMING MORE WIDESPREAD LATER THIS AFTN AS LAPSE RATES STEEPEN AND HEALTHY SHOT OF QG ASCENT MOVE INTO AREA. MTN TOP WINDS WILL BE SSW WHICH IS NOT GREAT FOR OROGRAPHICS WHICH WILL LIMIT SNOW AMOUNTS INITIALLY. EAST OF THE MTNS A SFC LOW WILL INTENSIFY NEAR DENVER THIS AFTN WITH GUSTY SSW WINDS DEVELOPING SOUTH OF A DENVER TO AKRON LINE. COULD SEE SOME GUSTS IN THE 40-50 MPH RANGE OVER THE PALMER DIVIDE TOWARDS LIMON. FOR NOW WILL NOT ISSUE A HIGH WIND WARNING OVER DOUGLAS...ELBERT AND LINCOLN COUNTIES BUT SPEEDS MAY GET CLOSE TO WARNING CRITERIA FOR A FEW HOURS BETWEEN 20Z AND 00Z. AS FOR TSTM CHANCES CAPES BY LATE AFTN WILL RANGE FM 500-1000 J/KG OVER THE NERN PLAINS. A SFC CONVERGENCE ZONE MAY DEVELOP FM NERN WELD ACROSS MORGAN INTO WASHINGTON COUNTIES SO THIS WILL BE AN AREA TO WATCH FOR CONVECTIVE DEVELOPMENT. SOUNDINGS SHOW SOME DECENT SHEAR BY LATE AFTN INTO THE EARLY EVENING HOURS SO THERE COULD BE A FEW STORMS WITH DAMAGING WINDS AND MARGINAL LARGE HAIL. AS FOR HIGHS THIS AFTN READINGS COULD VARY QUITE A BIT OVER NERN CO DUE TO HIGH LEVEL CLOUD COVER AND WEAK UPSLOPE BEHIND SFC LOW. FOR NOW WILL KEEP READINGS IN THE LOWER TO MID 60S CLOSER TO THE FOOTHILLS AND HAVE HIGHS IN THE LOWER TO MID 70S FURTHER EAST OVER THE PLAINS. FOR TONIGHT AN UPPER LEVEL LOW WILL BE OVER NERN CO/WRN NE AND WILL MOVE NE INTO NRN NEBRASKA BY 12Z FRI. AS THIS FEATURE MOVES ACROSS THIS EVENING WOULD EXPECT A GOOD CHC OF SHOWERS AND STORMS OVER THE FAR NERN PLAINS DURING THE EVENING HOURS WITH ACTIVITY DECREASING AFTER MIDNIGHT. IN THE MTNS OROGRAPHICS WILL BECOME MORE FAVORABLE AS WINDS BECOME WNW WITH CROSS-SECTIONS SHOWING DECENT MOISTURE IN THE 700-500 MB LAYER. THUS SHOULD SEE SNOW SHOWERS CONTINUE OVERNIGHT WITH ADVISORY AMOUNTS THRU FRI MORNING. IN ADDITION GUSTY WINDS WILL ALSO OCCUR WITH AREAS OF BLOWING SNOW OVER THE HIGHER PASSES. MEANWHILE IN AND NR THE FOOTHILLS A RATHER STG LOW LVL GRADIENT WILL EXIST WITH RATHER STG SUBSIDENCE DEVELOPING IN THE 06Z-12Z TIMEFRAME. CROSS-SECTIONS SHOW COMPONENT ALONG WINDS INCREASING TO 60-65 KTS OVERNIGHT SO THERE WILL BE A THREAT OF HIGH WINDS IN THE NORMALLY WINDY AREAS IN AND NR THE FOOTHILLS. THUS WILL ISSUE A HIGH WIND WATCH FM 06Z TONIGHT THRU 15Z ON FRI. LONG TERM...THE UPPER LEVEL TROUGH WILL CLOSE OFF AND INTENSIFY OVER THE DAKOTAS ON FRIDAY AS IT LIFTS NORTHEAST. COLORADO WILL BE UNDER A WEST-NORTHWEST FLOW ALOFT FRIDAY. STRONG DOWNSLOPE WINDS BEHIND THIS SYSTEM WILL DECREASE FRIDAY MORNING AS THE TROUGH EXITS THE AREA. THE FLOW ALOFT WILL REMAIN STRONG AND MOIST ENOUGH FOR OROGRAPHIC SNOW OVER THE MOUNTAINS. SNOW WILL LIKELY INCREASE IN COVERAGE AND INTENSITY FRIDAY AFTERNOON AS A SHORT WAVE TROUGH MOVES OVER THE REGION. MAY BE ENOUGH LIFT WITH THIS SYSTEM TO PRODUCE RAIN SHOWERS OVER THE PLAINS...MAINLY FRIDAY AFTERNOON AND EVENING. ONCE THIS FEATURE EXITS THE AREA...DRY AND MILD CONDITIONS WILL PREVAIL SATURDAY AS A WEAK RIDGE MOVES ACROSS THE STATE. MODELS STAY IN GOOD AGREEMENT THROUGH SUNDAY. THEY ARE SHOWING THE NEXT TROUGH BOTTOMING OUT OVER NEVADA AND UTAH. THIS WILL PRODUCE A SOUTHWEST FLOW ALOFT. BY AFTERNOON THERE MAY BE ENOUGH MOISTURE EMBEDDED IN THE FLOW ALOFT TO PRODUCE A FEW MOUNTAIN SHOWERS. TEMPERATURES WILL BE MILD WITH HIGHS IN THE 60S OVER NORTHEAST COLORADO. FOR MONDAY THROUGH WEDNESDAY...MODELS ARE SHOWING VARIOUS SOLUTIONS WHICH LEADS TO A LOW CONFIDENCE FORECAST. GENERAL PATTERN IS THAT A LARGE TROUGH WILL FORM OVER NORTHERN ROCKIES. THE MODELS SHOW A FEW SHORT WAVE TROUGHS ROTATING AROUND THE LOW. HOWEVER...THE GFS IS PROGRESSIVE WITH THE TROUGH AND HAS IT CENTERED OVER THE GREAT LAKES WEDNESDAY AFTERNOON. THE ECMWF HAS IT OVER THE NORTHERN ROCKIES THROUGH WEDNESDAY. WOULD EXPECT A PERIOD OR TWO OF BRIEF LIGHT PRECIPITATION OUT OF THIS PATTERN. THE TROUGH DOES NOT DIG FAR ENOUGH SOUTH TO PRODUCE A SIGNIFICANT STORM FOR COLORADO. WILL BROAD BRUSH 5-20 POPS FOR EARLY NEXT WEEK. TEMPERATURES ARE EXPECTED TO BE AT OR BELOW NORMAL UNDER THIS TYPE OF PATTERN AVIATION...THRU MID AFTN WILL TREND TOWARDS THE HRRR FOR SFC WINDS WHICH ARE GOING TO BE A NIGHTMARE TO FCST. AT THIS TIME LOOKS LIKE INITIAL SFC LOW WILL HANG AROUND THE AIRPORT THRU 18Z WITH WINDS BECOMING SSE ON THE EAST SIDE WHILE ON THE WEST SIDE WINDS WILL BE MORE NNW. BY 20Z THE HRRR LIFTS THE LOW INTO SCNTRL WELD COUNTY WITH WINDS SHIFTING TO THE SSW WITH SPEEDS IN THE 20-25 MPH RANGE WITH SOME GUSTS FM 35-40 MPH. MEANWHILE COULD SEE SOME WDLY SCT HIGH BASED STORMS DVLP IN THE 20Z-00Z TIME FRAME ALTHOUGH THE HRRR KEEPS MOST OF THIS ACTIVITY NORTH OF DIA. AS FOR CLOUDS EARLY THIS MORNING THERE ARE SOME CEILINGS IN THE 3500-4000 FT RANGE FM BJC TO LONGMONT HOWEVER DUE TO HI LVL CLOUDS DO NOT KNOW HOW FAR EAST THESE CLOUDS ARE. FOR NOW WILL CONTINUE WITH A TEMPO GROUP FOR CEILINGS IN THE 4000 FT RANGE THRU 14Z. IF SFC LOW STAY WEST OF DIA THEN THESE LOWER CEILINGS MAY NOT AFFECT THE AIRPORT. FOR TONIGHT GUSTY SSW WINDS SHOULD BECOME MORE WLY BY 02Z WITH SOME GUSTS TO 25 MPH THRU 06Z POSSIBLE. IN FACT THESE GUSTY WINDS COULD CONTINUE THRU FRI MORNING IF STRONGER WINDS NR THE FOOTHILLS MIX DOWN TO THE SFC. HYDROLOGY...NO ISSUES. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR COZ035-036-038-039. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON MDT FRIDAY FOR COZ031-033-034. && $$ SHORT TERM...ENTREKIN LONG TERM....MEIER AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1045 AM EDT THU OCT 10 2013 .UPDATE (REST OF TODAY THROUGH FRIDAY)... 14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER ENERGETIC UPPER LEVEL PATTERN OVER THE CONUS. DEEP AND SHARP TROUGHING IS IN PLACE OVER THE INTER-MOUNTAIN WEST WHICH IS ANCHORED BY A VIGOROUS UPPER LOW NEAR THE 4-CORNERS REGION. QUITE A BIT OF LIGHTNING SHOWING UP WITHIN THE COLD POOL UNDER THE LOW...HIGHLIGHTING THE STRENGTH OF THIS FEATURE. NORTHERN STREAM FLOW THEN RIDGES TO THE NORTH THROUGH THE HIGH PLAINS INTO SOUTH-CENTRAL AND SOUTHEAST CANADA. REMOVED FROM THIS FLOW IS A BROAD TROUGH ALONG THE EAST COAST WITH AN UPPER LOW SPINNING OVER THE DELMARVA REGION. THIS FEATURE AND AN ASSOCIATED SURFACE REFLECTION LOW WILL REMAIN IN PLACE THROUGH THE NEXT COUPLE OF DAYS PROVIDING A WET AND DREARY FORECAST TO THE MID-ATLANTIC STATES. OUR POSITION BEHIND THIS TROUGH AXIS GIVES US A VERY DIFFERENT FORECAST TO THOSE AREAS TO OUR NORTH. WV IMAGERY SHOWS SIGNIFICANT SUPPRESSION/DRYING WORKING SOUTHWARD OVER THE FLORIDA PENINSULA. IN FACT...THE GFS AND ECMWF SUGGEST THE UPPER LEVEL Q-VECTOR DIVERGENCE WILL ONLY INCREASE WITH TIME INTO TONIGHT OVER OUR FORECAST AREA. 10/12Z RAOBS ACROSS THE STATE SHOWED A STEADY DECREASE IN PW VALUES FROM SOUTH TO NORTH WITH KMFL AROUND 1.7"...KTBW...JUST OVER 1"...AND KJAX DOWN BELOW 1". THESE VALUES ARE BELOW NORMAL...BUT NOT UNHEARD OF FOR MID OCTOBER. HOWEVER...THE COMBINATION OF THE DRIER COLUMN...NO FOCUS MECHANISM...AND THE OVERALL SUPPRESSION OF THE MID/UPPER TROP WILL KEEP OUR FORECAST RAIN FREE THROUGH THE NEXT COUPLE OF DAYS. BARELY A CLOUD IN THE SKY LATE THIS MORNING FOR MUCH OF THE FORECAST AREA. SEEING A FEW LOWER LEVEL CLOUDS DOWN TOWARD FT. MYERS...BUT OTHERWISE BRIGHT AND SUNNY FOR THE REST OF THE ZONES. WE DO SEE SCT-BKN STRATOCU BEGINNING ABOUT 20 OR SO MILES OFFSHORE INTO THE GULF. THESE LOWER CLOUDS ARE AN INSTABILITY RESPONSE TO THE COOL MORNING LAND TEMPS BEING ADVECTED OUT OVER THE WARMER GULF WATERS...A SURE SIGN THAT FALL IS BEGINNING TO ARRIVE. EARLY MORNING LOW TEMPERATURES REACHED DOWN INTO THE UPPER 50S OVER PORTIONS OF THE NATURE COAST WITH GENERALLY 60S ELSEWHERE. REST OF TODAY...VERY LITTLE TO NO CHANCE OF RAIN THROUGH THE REST OF THE DAY. TIME-HEIGHT PLOTS SHOW ENOUGH LOW LEVEL TRAPPED MOISTURE UNDERNEATH THE UPPER LEVEL SUPPRESSION TO SUPPORT A SCT AND SHALLOW CU FIELD FOR OUR SOUTHERN ZONES THROUGH THE AFTERNOON HOURS...HOWEVER...BY THE TIME YOU GET TO TAMPA AND NORTHWARD...EVEN MUCH OF THIS LOWER LEVEL MOISTURE HAS BEEN SCOURED OUT...AND WOULD EXPECT A FEW CU AT BEST. WILL KEEP THE FORECAST MOSTLY SUNNY WITH HIGH TEMP REACHING THE MIDDLE 80S BY 3-4PM. SKIES BECOME CLEAR QUICKLY WITH THE SETTING OF THE SUN. THE DRY ATMOSPHERE AND CLEAR SKIES WILL ALLOW FOR ANOTHER COMFORTABLY COOL OCTOBER NIGHT INTO EARLY FRIDAY MORNING. LOW TEMPS BY SUNRISE SHOULD REACH DOWN IN THE UPPER 50S/AROUND 60 NORTH OF TAMPA...AND IN THE 60S SOUTH OF THE I-4 CORRIDOR. THE COOL START FRIDAY MORNING WILL ONLY LEAD INTO YET ANOTHER MAINLY SUNNY AND SEASONABLE DAY TO END OUT THE WORK WEEK. ENJOY! && .AVIATION... LIMITED EARLY MORNING BR/LOW CIGS HAVE LIFTED. VFR THROUGH 11/12Z WITH ONLY FEW-SCT AOA 035. NE WINDS BACK TO NORTH OR NW DURING THE AFTERNOON AT COASTAL TERMINALS...AT 9 KT OR LESS. && .MARINE... HIGH PRESSURE WILL BUILD OVER THE NORTHEAST GULF OF MEXICO THROUGH THIS EVENING...AND THEN REMAIN IN PLACE THROUGH AT LEAST THE FIRST HALF OF THE UPCOMING WEEKEND. NORTH OF THE WATERS AND REMAIN IN PLACE THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... TPA 86 69 86 68 / 0 0 0 0 FMY 88 69 88 67 / 10 0 0 0 GIF 88 67 88 65 / 0 0 0 0 SRQ 85 68 86 66 / 0 0 0 0 BKV 87 56 87 55 / 0 0 0 0 SPG 84 73 86 70 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/MARINE...MROCZKA AVIATION...RUDE Area Forecast Discussion National Weather Service Lincoln IL 1042 AM CDT Thu Oct 10 2013 .DISCUSSION... ISSUED 1038 AM CDT Thu Oct 10 2013 High pressure ridge extending back from the eastern Great Lakes into the Midwest this morning. Very few clouds associated with a small stretch of moisture creeping into the llvls. Other than a few clouds...not much in the way of weather to speak of in the short term. Somewhat variable and light winds in the absence of a strong gradient...though south-southwesterly is the predominant direction. Forecast on track, but will update the grids for a quicker diurnal warm up this morning, and send update to eliminate the morning fog wording in the southern tier. HJS && .AVIATION... ISSUED 629 AM CDT Thu Oct 10 2013 VFR conditions will continue next 24hrs at all TAF sites. Lower level moisture streaming up into the area currently and will continue through the day and into tonight. Sct to broken clouds around 4kft being reported in the obs and satellite shows this as well. Based on satellite loop and obs, will have broken cigs at all sites except for PIA during the day. Then all sites will scatter out for this evening with scattered clouds continuing overnight tonight. Winds will be southerly to southeasterly through the whole period. Winds speeds strongest during the day at 7-8kts but then decrease some after sunset. Auten && .PREV DISCUSSION... ISSUED 305 AM CDT Thu Oct 10 2013 SHORT TERM...Today through Saturday Gradual moisture advection from the south over the past 24 hours has resulted in 50+ surface dewpoints spreading northward into southern Illinois early this morning. Due to the increased low-level moisture and nearly calm winds beneath ridge axis, areas of fog are beginning to develop south of I-70. HRRR shows the fog developing/spreading further north toward dawn. Have therefore included patchy fog along and south of a Jacksonville to Paris line through 14z/9am. Once early morning fog dissipates, partly to mostly sunny skies and very warm conditions will prevail for the remainder of the day. Afternoon high temperatures will be a degree or two warmer than yesterday, with readings reaching the middle to upper 70s. As ridge only slowly shifts eastward, the potential exists for more patchy fog tonight. Given increasing moisture, clear skies, and continued light winds near the departing ridge axis, will include fog mention for the eastern half of the KILX CWA. Further west, light return flow should keep atmosphere mixed just enough to prevent fog west of I-55. Once fog dissipates, another mostly sunny and warm day will unfold on Friday...with highs reaching the 80-degree mark. 00z Oct 10 models have sped up the approach of the weekend system, with FROPA now expected to occur Saturday afternoon. NAM is the fastest of the models, but think it is too aggressive with pushing the front eastward into the prevailing upper ridge. Will therefore trend closer to the slightly slower ECMWF/GFS solution. With front expected to be along the Mississippi River by 12z Saturday, will maintain low chance POPs in the Illinois River Valley late Friday night, then will spread rain chances further east across the rest of the area on Saturday. With best upper support remaining well to the N/NW and only a shallow moisture profile in place, am not expecting a widespread soaking rainfall on Saturday. Will keep POPs in the chance category accordingly. Since system is moving a bit faster than previously forecast, will only hold on to chance POPs across the eastern CWA into the evening hours, then will go dry across the board overnight. LONG TERM...Sunday through Wednesday High pressure will build into the region behind the departing cold front on Sunday, with models indicating a very dry airmass with dewpoints in the lower to middle 40s settling in. Mostly clear and dry weather is expected for both Sunday and Monday, with warm afternoon highs in the upper 60s/lower 70s and cool overnight lows in the 40s. Next system is still slated to come into the picture early next week, although details are not clear at this point. An upper-level trough is expected to dig into the Rockies Sunday into Monday, although how deep the system becomes and how quickly it lifts northeastward are still very much in question. GFS is more progressive with the system, with the upper low and its associated surface wave ejecting into the western Great Lakes by Tuesday evening. Meanwhile, latest ECMWF is deeper and holds the system back in the Rockies/Plains until Thursday. Given significant timing discrepancies, have opted to leave going forecast alone until better agreement is achieved. As such, am expecting showers and thunderstorms to develop across the area Monday night into Tuesday, followed by cooler/drier weather by Wednesday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
648 AM CDT THU OCT 10 2013 .DISCUSSION... 322 AM CDT TODAY THROUGH TONIGHT... SIMILAR STORY FOR TODAY...ABUNDANT SUNSHINE AND UNSEASONABLE WARMTH ACROSS THE REGION. BROAD ANTI-CYCLONIC FLOW REMAINS ANCHORED ACROSS THE EASTERN THIRD OF THE CONUS...WITH A WAVE LIFTING NORTHEAST OFF OF THE VIRGINIA COAST. NEAR CLOUDLESS SKIES WITH LIGHT TO CALM WINDS EARLY THIS MORNING ACROSS THE FORECAST AREA. VWP FROM WSR-88D KLOT INDICATE WINDS REMAIN RATHER UNIFORM FROM THE EAST AT 1-9KFT AGL. LOCATIONS ADJACENT TO LAKE MICHIGAN IN FAR NORTHEAST IL CONTINUE TO SEE TEMPS HOLDING IN THE LOW 50S...WHILE FURTHER SOUTH IN THE METRO CHICAGO AREA TEMPS HOVER IN THE MID 50S. ELSEWHERE TEMPS HAVE RADIATED INTO THE LOW/MID 40S...WITH T/TD SPREADS NEARING 2 DEG OR LESS. THE COMBINATION OF MINIMAL T/TD SPREADS AND CALM WINDS HAS ALLOWED PATCHY FOG TO DEVELOP AGAIN THIS MORNING. EXPECT A FEW LOW LYING AREAS TO SEE VSBYS REDUCED TO ARND 1SM...HOWEVER SHOULD ONLY LINGER UNTIL JUST AFTER DAYBREAK. SHORTLY AFT SUNRISE THE SFC SHUD QUICKLY WARM GIVEN THE PAST SEVERAL DAYS OF DRY CONDS. THIS HAS RESULTED IN REDUCED HEAT CAPACITY...AND ATMOSPHERIC PARCELS WILL RESPOND TO THE SOLAR RADIATION IN THE FORM OF A LARGE DIURNAL SWING IN TEMPS TODAY. PLUMES SUGGEST TEMPS WILL BE IN THE MID/UPR 70S FOR MUCH OF THE CWFA...WITH THE EXCEPTION OF AREAS ADJACENT TO LAKE MICHIGAN. AN AFTN LAKE BREEZE IS EXPECTED TO DEVELOP AND PUSH INLAND...WHICH WILL LIKELY CAP TEMPS DOWNTOWN CHICAGO IN THE UPR 60S. TONIGHT DRY WEATHER CONTINUES WITH NEAR CLOUDLESS SKIES YET AGAIN...A FEW CIRRUS CLOUDS MAY SLIDE OVERHEAD WHICH MAY SLOW THE RATE OF COOLING TONIGHT. THUS IT APPEARS TEMPS WILL LIKELY BE SLIGHTLY WARMER IN THE LOW 50S...WITH A FEW TRADITIONAL LOCATIONS RADIATING INTO THE UPR 40S. CONFIDENCE...HIGH. FRIDAY THROUGH SATURDAY... MID-LVL RIDGING CONTINUES TO HANG TOUGH THROUGH MUCH OF FRI...AS THE STRENGTH OF THE 500MB RIDGE OVER QUEBEC/EASTERN ONTARIO REMAINS PROGGED AT 3 SIGMA. GIVEN THE STRENGTH OF THE DOWNSTREAM RIDGE THROUGH FRI NGT...IT APPEARS TO BE HAVING A SIGNIFICANT DIMINISHING ROLE IN THE APPROACHING MID-LVL SHORTWAVE THAT WILL LIFT NORTHEAST FROM THE FOUR-CORNERS REGION. OPERATIONAL GUIDANCE HAS CONTINUED TO TREND DRIER WITH THIS SYSTEM...WITH THE EARLIEST PRECIP NOT ARRIVING UNTIL ARND DAYBREAK SAT. LCL WRF MODEL THRU 12Z SAT INDICATES DRY WEATHER WITH THE FRONTAL BOUNDARY MUCH FASTER AND NEARING FAR NORTHWEST IL ARND DAYBREAK SAT. EC/GFS BOTH HAVE TRENDED DRIER WITH THE EARLY WEEKEND SYSTEM...WITH THE BEST DYNAMICS PASSING WELL NORTHWEST OF THE FORECAST AREA SAT. IT IS CONCEIVABLE THAT SAT MAY JUST SEE SPOTTY SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM SOUTH OF I-80...AS MUCAPE IN THE SFC-500MB LAYER HOVERS ARND 200-400J/KG. THIS TOO HAS BEEN ON A DECREASING TREND. AT THIS TIME HAVE HELD ONTO MENTION OF ISOLATED THUNDER FOR SAT THRU SAT EVE...THEN WITH THE FORWARD SPEED INCREASING FOR SAT NGT HAVE PULLED MENTION OF PRECIP AFT MIDNIGHT. FLOW THEN TURNS NORTHWEST BEHIND THE BOUNDARY...WITH COOLER/DRIER AIR FILTERING INTO THE CWFA FOR THE REMAINDER OF THE WEEKEND. TEMPS FRI AHEAD OF THE SYSTEM WILL LIKELY BE WARM AGAIN...WITH STRONG SOUTHEASTERLY TURNING SOUTHERLY FLOW. MANY PLUMES INDICATE TEMPS WILL BE IN THE MID/UPR 70S FRI...AND COULD PERHAPS SEE A HANDFUL OF POINTS REACH 80 DEGREES SOUTH OF A LASALLE TO KANKAKEE LINE. THEN WITH INCREASED CLOUD COVER FRI NGT TEMPS WILL REMAIN MILD IN THE MID/UPR 50S. DEPENDING ON THE TIMING OF FRONTAL PASSAGE SAT...AND IF CLOUD COVER CAN ERODE QUICK ENOUGH BEFORE SUNSET...TEMPS COULD STILL WARM INTO THE LOW/MID 70S. THE WARMEST LOCATIONS WILL LIKELY BE THE SOUTHEAST CWFA WHERE TEMPS MAY TOUCH 80 DEG SAT AFTN. CONFIDENCE...HIGH. SUNDAY THROUGH WEDNESDAY... ENSEMBLES HAVE CONTINUED TO PROG SLOW WEAKENING IN THE 500MB RIDGE OVER QUEBEC SUN...WITH THE TROUGH OVER THE CENTRAL CONUS FLATTENING. AN ELONGATED TROUGH APPEARS TO SETUP SUN NGT STRETCHING SOUTHWEST THROUGH THE ROCKIES...THEN RIDGING IS POISED TO DEVELOP ACROSS THE PAC-NW MON INTO TUE. THE INCREASING MID-LVL HEIGHTS ACROSS THE PAC-NW/WESTERN CANADA WILL PLAY A ROLE IN A POSSIBLE PATTERN ADJUSTMENT TOWARDS THE MIDDLE OF NEXT WEEK. OPERATIONAL GUIDANCE SLIDES SFC RIDGE INTO THE REGION SUN THRU MON...THEN QUICKLY DRIFTS NORTHEAST MON NIGHT. OPERATIONAL GUIDANCE HAS COME INTO BETTER AGREEMENT WITH A SHORTWAVE LIFTING INTO THE CENTRAL PLAINS MON NGT...WITH CONSIDERABLE MOISTURE BEING PUMPED INTO THIS FEATURE. GUIDANCE THEN BRINGS PRECIP NORTHEAST INTO THE FORECAST AREA MON NGT/TUE. SOME UNCERTAINTY REMAINS WITH RESPECT TO THE TIMING/COVERAGE OF PRECIP...HOWEVER CONCEPTUALLY THIS SYSTEM WOULD LIKELY PRODUCE A DECENT SLUG OF PRECIP TUE BEFORE A DRY SLOT PIVOTS EAST TUE NGT/WED. THE OVERALL THEME WITH TEMPS IN THE EXTENDED PERIODS IS MORE OF A SEASONAL SETUP...HOWEVER TEMPS COULD REMAIN MUCH COOLER IF ABUNDANT PRECIP DOES DEVELOP. THIS COULD HOLD TEMPS IN THE MID/UPR 50S...AT THIS POINT HAVE HELD ONTO TEMPS IN THE LOW/MID 60S. THEN TOWARDS THE MIDDLE OF NEXT WEEK WITH THE AFOREMENTIONED RIDGING ACROSS THE PAC-NW/WESTERN CANADA REMAINING IN PLACE...THIS WILL LIKELY PROVIDE COOLER AIR TO SLIDE SOUTHEAST ACROSS CENTRAL CANADA AND PUSH IN BEHIND THE EARLY WEEK SYSTEM INTO THE CWFA WED. HIGHS WED MAY STRUGGLE TO WARM BEYOND THE MID 50S. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * LAKE BREEZE THIS AFTERNOON. CMS //DISCUSSION...UPDATED 12Z... A RIDGE OF HIGH PRESSURE EXTENDS OVER THE GREAT LAKES REGION THIS MORNING AND WILL VERY SLOWLY DRIFT EAST TONIGHT AND FRIDAY. CALM WINDS TO START WILL BECOME SOUTHEASTERLY UNDER 10KTS THIS MORNING. THIS HIGH WILL ALSO ALLOW A LAKE BREEZE TO FORM WITH WINDS TURNING EASTERLY AT ORD/MDW BY MID AFTERNOON...NORTHEASTERLY AT GYY. WINDS WILL THEN SETTLE BACK TO LIGHT SOUTHEASTERLY AFTER SUNSET. HIGH CLOUDS WILL SPREAD ACROSS THE REGION THIS MORNING AND A 4-5KFT STRATOCU DECK HAS DEVELOPED ACROSS SOUTH CENTRAL IL. THIS MOISTURE WILL LIKELY CREEP NORTH THROUGH THE DAY AND SOME CU ARE POSSIBLE THIS AFTERNOON. FOG HAS BEEN QUITE VARIABLE EARLY THIS MORNING DUE TO ITS SHALLOW NATURE. SOME MVFR VIS IS STILL POSSIBLE FOR A FEW HOURS AT RFD/DPA...OTHERWISE VFR EXPECTED INTO THIS EVENING. WITH A BIT MORE LOW LEVEL MOISTURE TONIGHT...EXPECT SIMILAR CONDITIONS WITH LIGHT/SHALLOW FOG DEVELOPING IN SOME AREAS AFTER MIDNIGHT. CMS //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH FOR A LAKE BREEZE REACHING ORD/MDW...MEDIUM FOR TIMING. CMS //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... * FRIDAY NIGHT...DRY/VFR. * SATURDAY...CHANCE OF SHRA/SLIGHT CHANCE OF TSRA. COLD FRONT/WIND SHIFT TO THE WEST BY EARLY AFTERNOON. * SUNDAY AND MONDAY...DRY/VFR. * TUESDAY AND WEDNESDAY...CHANCE OF SHRA. && .MARINE... 300 AM...A LARGE RIDGE OF HIGH PRESSURE EXTENDING FROM THE WESTERN LAKES TO NEW ENGLAND WILL SLOWLY DRIFT SOUTHEAST TONIGHT AND FRIDAY AND EVENTUALLY MERGE WITH STRONGER HIGH PRESSURE MOVING SOUTHEAST ACROSS QUEBEC FRIDAY AND FRIDAY NIGHT. THIS WILL MAINTAIN MAINLY SOUTHEASTERLY FLOW OVER THE LAKE INTO FRIDAY WITH SPEEDS GRADUALLY INCREASING INTO THE 10-20 KT RANGE FRIDAY. WEAK LOW PRESSURE NEAR COLORADO THIS MORNING WILL DEEPEN AS IT MOVES NORTH ACROSS THE DAKOTAS FRIDAY AND ACROSS MANITOBA AND WESTERN ONTARIO FRIDAY NIGHT. THIS WILL CAUSE THE GRADIENT TO TIGHTEN ACROSS THE WESTERN LAKES FRIDAY NIGHT INTO SATURDAY MORNING WITH A PERIOD OF 20-25KTS POSSIBLE. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE SATURDAY AFTERNOON OR SATURDAY EVENING SHIFTING WINDS TO THE WEST AND THEN TO THE NORTHWEST SATURDAY NIGHT INTO SUNDAY. HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE LAKES REGION SUNDAY INTO SUNDAY NIGHT. ANOTHER LOW PRESSURE IS EXPECTED TO MOVE FROM THE CENTRAL PLAINS MONDAY ACROSS THE LAKES REGION TUESDAY INTO WEDNESDAY... THOUGH CONFIDENCE REGARDING THE STRENGTH AND TRACK OF THIS SYSTEM REMAINS LOW AT THIS TIME. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 629 AM CDT Thu Oct 10 2013 .DISCUSSION... ISSUED 305 AM CDT Thu Oct 10 2013 SHORT TERM...Today through Saturday Gradual moisture advection from the south over the past 24 hours has resulted in 50+ surface dewpoints spreading northward into southern Illinois early this morning. Due to the increased low-level moisture and nearly calm winds beneath ridge axis, areas of fog are beginning to develop south of I-70. HRRR shows the fog developing/spreading further north toward dawn. Have therefore included patchy fog along and south of a Jacksonville to Paris line through 14z/9am. Once early morning fog dissipates, partly to mostly sunny skies and very warm conditions will prevail for the remainder of the day. Afternoon high temperatures will be a degree or two warmer than yesterday, with readings reaching the middle to upper 70s. As ridge only slowly shifts eastward, the potential exists for more patchy fog tonight. Given increasing moisture, clear skies, and continued light winds near the departing ridge axis, will include fog mention for the eastern half of the KILX CWA. Further west, light return flow should keep atmosphere mixed just enough to prevent fog west of I-55. Once fog dissipates, another mostly sunny and warm day will unfold on Friday...with highs reaching the 80-degree mark. 00z Oct 10 models have sped up the approach of the weekend system, with FROPA now expected to occur Saturday afternoon. NAM is the fastest of the models, but think it is too aggressive with pushing the front eastward into the prevailing upper ridge. Will therefore trend closer to the slightly slower ECMWF/GFS solution. With front expected to be along the Mississippi River by 12z Saturday, will maintain low chance POPs in the Illinois River Valley late Friday night, then will spread rain chances further east across the rest of the area on Saturday. With best upper support remaining well to the N/NW and only a shallow moisture profile in place, am not expecting a widespread soaking rainfall on Saturday. Will keep POPs in the chance category accordingly. Since system is moving a bit faster than previously forecast, will only hold on to chance POPs across the eastern CWA into the evening hours, then will go dry across the board overnight. LONG TERM...Sunday through Wednesday High pressure will build into the region behind the departing cold front on Sunday, with models indicating a very dry airmass with dewpoints in the lower to middle 40s settling in. Mostly clear and dry weather is expected for both Sunday and Monday, with warm afternoon highs in the upper 60s/lower 70s and cool overnight lows in the 40s. Next system is still slated to come into the picture early next week, although details are not clear at this point. An upper-level trough is expected to dig into the Rockies Sunday into Monday, although how deep the system becomes and how quickly it lifts northeastward are still very much in question. GFS is more progressive with the system, with the upper low and its associated surface wave ejecting into the western Great Lakes by Tuesday evening. Meanwhile, latest ECMWF is deeper and holds the system back in the Rockies/Plains until Thursday. Given significant timing discrepancies, have opted to leave going forecast alone until better agreement is achieved. As such, am expecting showers and thunderstorms to develop across the area Monday night into Tuesday, followed by cooler/drier weather by Wednesday. Barnes && .AVIATION... ISSUED 629 AM CDT Thu Oct 10 2013 VFR conditions will continue next 24hrs at all TAF sites. Lower level moisture streaming up into the area currently and will continue through the day and into tonight. Sct to broken clouds around 4kft being reported in the obs and satellite shows this as well. Based on satellite loop and obs, will have broken cigs at all sites except for PIA during the day. Then all sites will scatter out for this evening with scattered clouds continuing overnight tonight. Winds will be southerly to southeasterly through the whole period. Winds speeds strongest during the day at 7-8kts but then decrease some after sunset. Auten && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
936 AM CDT THU OCT 10 2013 .UPDATE... ISSUED AT 935 AM CDT THU OCT 10 2013 MAIN FORECAST CONCERN THIS MORNING WILL BE WHICH 12Z MODEL INITIALIZES BEST FOR PRECIP STARTING LATE TONIGHT INTO FRI MORNING. 12Z NAM APPEARS TO BE TOO DRY WITH ACTIVITY OVER EASTERN SD WHILE THE LATEST RUC IS TOO AGGRESSIVE IN BRINGING THAT SHOWERY ACTIVITY INTO OUR CWA (TOO EARLY IF AT ALL). SO NO PLANS (FROM LATEST NAM RUN) FOR MAIN SYSTEM WHICH WILL BRING RAIN TO THE AREA TOMORROW. ONLY FCST CHANGE FOR NOW WILL BE TO FURTHER INCREASE SKY BASED ON CURRENT SAT TRENDS...MAINLY ACROSS THE NORTHERN HALF OF CWA. WILL LOOK AT TEMPS CLOSER TO 10 AM BUT NO MAJOR PLANS EXPECTED FOR DAYTIME HIGHS. UPDATE ISSUED AT 641 AM CDT THU OCT 10 2013 MADE A FEW TWEAKS TO CLOUDS AS HIGH AND MID LEVEL CLOUDS CONTINUE TO SPREAD OVER THE AREA ALTHOUGH THERE APPEAR TO BE SOME BREAKS. TEMPS HAVE STAYED IN THE 40S TO LOW 50S AND THINK EVEN WITH HIGH CLOUDS WE SHOULD STILL GET INTO THE 60S AND 70S THIS AFTERNOON. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 345 AM CDT THU OCT 10 2013 TEMPERATURES TODAY AND PRECIP CHANCES TONIGHT AND TOMORROW WILL BE THE MAIN ISSUES FOR THE SHORT TERM. WV LOOP SHOWS THE MAIN UPPER LOW DIGGING FROM SOUTHERN CA INTO AZ...AND THE SYSTEM WILL SWING NORTHEASTWARD INTO THE CENTRAL ROCKIES LATER TODAY. A WEAK LEAD SHORTWAVE HAS BEEN PRODUCING SOME SHOWERS OVER NORTHWESTERN ND...BUT THE UPPER FLOW HAS IT TRACKING INTO CANADA AND STAYING WEST OF US. WILL CONTINUE TO KEEP THE FORECAST DRY THROUGH 00Z. THERE WILL BE PLENTY OF MID AND HIGH CLOUDS IN THE SOUTHWESTERLY FLOW OVER THE NORTHERN PLAINS. INSOLATION WILL BE REDUCED A BIT BUT THERE WILL BE PLENTY OF WARM AIR ADVECTION AS SOUTHEASTERLY WINDS PICK UP AHEAD OF THE SFC LOW TODAY. KEPT HIGHS IN THE UPPER 60S TO MID 70S. THE UPPER LOW WILL BE CLOSING OFF AND MOVING INTO THE SD/NEB REGION TONIGHT. Q VECTOR CONVERGENCE SHOWS THE BEST SUPPORT WITH THE UPPER LOW WILL REMAIN MOSTLY TO OUR SOUTHWEST OVERNIGHT...BUT SOME PRECIP COULD BEGIN TO MOVE INTO THE DEVILS LAKE AREA LATER ON. MADE ONLY MINOR TWEAKS TO THE 30-40 POPS THAT WE HAD GOING FOR OUR WESTERN COUNTIES. THE UPPER LOW WILL BE LIFTING INTO EASTERN ND DURING THE DAY ON FRIDAY...WITH A FAIRLY STACKED SFC LOW TAKING A SIMILAR TRACK. THE MODELS STILL HAVE SOME MINOR DIFFERENCES IN EXACTLY WHERE THEY PUT THE SFC LOW BUT ARE IN BETTER AGREEMENT THAN LAST NIGHT. WITH STRONG UPPER SUPPORT AS THE SYSTEM MOVES INTO THE AREA CONTINUED TO KEEP PRETTY HIGH POPS FOR FRIDAY AS SHOWERS AND THUNDERSTORMS MOVE ACROSS THE AREA IN THE WARM SIDE OF THE SFC LOW. WITH THE VERY STRONG UPPER SYSTEM...THERE IS THE POSSIBILITY OF SOME LOW TOPPED SUPERCELLS IF WE GET THE CAPE THAT THE NAM IS SUGGESTING...AROUND 500 J/KG. MUCH WILL DEPEND ON HOW MUCH CLOUD COVER WE REALLY END UP WITH...AND SOME OF THE MODELS HAVE NOT MUCH SFC INSTABILITY AT ALL. WILL INCLUDE A MENTION IN THE HWO FOR POSSIBILITY OF SEVERE BUT WILL NOT INCLUDE IN GRIDS FOR NOW. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 345 AM CDT THU OCT 10 2013 FRIDAY NIGHT...THE UPPER LOW WILL LIFT OFF INTO CANADA...AND THE COLD FRONT WILL MOVE THROUGH. WITH THE TIGHT PRESSURE GRADIENT WINDS WILL BECOME QUITE STRONG AND BE ASSISTED BY COLD AIR ADVECTION ON THE BACKSIDE OF THE SFC LOW. SO WILL HAVE TO WATCH OUT FOR ADVISORY CRITERIA EVEN AT NIGHT. SHOWERS WILL CONTINUE MAINLY OVER THE NORTHERN CWA AS PRECIP WRAPS AROUND THE BACKSIDE OF THE LOW AS IT LIFTS OUT. THE ECMWF AND GEM KEEP PRECIP A BIT FURTHER WEST INTO SATURDAY WHILE THE DOMESTIC MODELS JUST KEEP SOME ACTIVITY OVER THE NORTHEASTERN COUNTIES. WITH CONVECTIVE TEMPS PRETTY LOW THINK THAT SHOWER ACTIVITY WILL CONTINUE OVER AT LEAST PART OF THE CWA SO KEPT 20-30 POPS GOING FOR A WHILE EVEN AS SFC HIGH PRESSURE BUILDS INTO THE AREA. THE SFC HIGH AND COOL AIR WILL HELP SATURDAY NIGHT DROP BACK INTO THE 30S. SUNDAY TO WEDNESDAY NIGHT...MODELS IN FAIR AGREEMENT WITH THE BEGINNING OF NEXT WEEK BRINGING IN THE NEXT STORM SYSTEM ON MONDAY AND INTO TUESDAY. POPS INCREASED TO LIKELY ACROSS THE S RRV FOR TUESDAY AM AS SHORTWAVE ENERGY MOVES INTO THE E DAKOTAS WHILE THE 500MB TROUGH STAYS POSITIVELY TILTED ACROSS THE FOUR CORNERS TO THE NORTHERN PLAINS. MODEL SOLNS CONTINUE TO AGREE WITH THE MOST QPF ACROSS THE SOUTH WITH VERY LITTLE IN THE NORTHERN HALF OF THE FA. TEMPS TO BE IN THE 50S FOR HIGHS FOR THE FIRST HALF OF THE WEEK...AT TO SLIGHTLY BELOW MID OCT NORMALS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 641 AM CDT THU OCT 10 2013 VFR CIGS CONTINUE OVER THE FORECAST AREA WITH MID AND HIGH CLOUDS MOSTLY ABOVE 8500 FT. A BIT OF LIGHT FOG BROUGHT VIS AT KTVF TO 4SM...BUT REDUCTIONS HAVE BEEN IN AND OUT AND SHOULD DISAPPEAR COMPLETELY IN THE NEXT HOUR OR SO. LIGHT WINDS WILL PICK UP OUT OF THE SOUTHEAST TODAY AND TONIGHT. THERE COULD BE A FEW SHOWERS NEAR KDVL TOWARDS THE END OF THE PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...SPEICHER SHORT TERM...JR LONG TERM...JR/JK AVIATION...JR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
704 AM CDT THU OCT 10 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM CDT THU OCT 10 2013 NO FORECAST CONCERNS FOR THE SHORT TERM PERIOD WITH QUIET WEATHER CONTINUING. CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A NORTHERN STREAM UPPER TROUGH CROSSING BRITISH COLUMBIA...A DEEP UPPER LOW/TROUGH OVER SOUTHERN CALIFORNIA...AND STRONG RIDGING FROM EASTERN TEXAS THROUGH THE EASTERN GREAT LAKES. VERY LITTLE CLOUD COVER TO SPEAK OF FROM THE CENTRAL PLAINS INTO THE FORECAST AREA... EXCEPT FOR A BAND OF CIRRUS ASSOCIATED WITH A SHORTWAVE LIFTING THROUGH WESTERN IA. THE LACK OF CLOUD COVER IS A RESULT OF PLENTIFUL DRY AIR SEEN ON 00Z SOUNDINGS FROM GRB...DVN...MPX...OAX AND DDC. AT THE SURFACE...LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO WHILE HIGH PRESSURE WAS PRESENT OVER LOWER MICHIGAN. THE PRESSURE GRADIENT BETWEEN THESE FEATURES OVER THE FORECAST AREA IS LIGHTER THAN THIS TIME YESTERDAY...RESULTING IN LIGHTER WINDS AND THEREFORE COOLER TEMPERATURES. THE TYPICAL WISCONSIN COLD SPOTS HAVE DROPPED INTO THE UPPER 30S...MEANWHILE HIGHER TERRAIN SITES ALONG AND WEST OF THE MISSISSIPPI RIVER WHICH ARE EXPERIENCING MORE WIND ARE IN THE LOW TO MID 50S. AIRMASS REMAINS ABNORMALLY WARM... THOUGH...WITH 00Z SOUNDINGS SHOWING 925MB TEMPERATURES OF 15-17C EAST TO WEST. THE DRY CONDITIONS WILL CONTINUE FOR ANOTHER 24 HOURS AS THE FORECAST AREA REMAINS SITUATED IN A BLOCKED UPPER LEVEL PATTERN. THAT PATTERN FEATURES THE UPPER LOW IN SOUTHERN CALIFORNIA PROGGED TO EJECT NORTHEASTWARD TOWARDS THE BLACK HILLS OF SOUTH DAKOTA BY 12Z FRIDAY...WHILE STRONG RIDGING HOLDS IN PLACE OVER LOWER MICHIGAN. EXPECT WINDS TO INCREASE...A RESULT OF THE PRESSURE GRADIENT TIGHTENING AHEAD OF THE DEEPENING SURFACE LOW IN COLORADO LIFTING NORTH WITH THE UPPER LOW. THE STRONGER SOUTHERLY WINDS DO NOT BRING ANY WARMER AIR IN FOR TODAY AT 925MB...AS MODEL FORECASTS SUGGESTS 925MB TEMPERATURES END UP AGAIN BETWEEN 16-18C AT 00Z. THUS HIGHS ARE LIKELY TO BE SIMILAR TO THOSE SEEN YESTERDAY. HOWEVER... THE WINDS WILL HELP TO KEEP THE NEAR SURFACE LAYER MORE MIXED TONIGHT...RESULTING IN A WARMER NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 225 AM CDT THU OCT 10 2013 FORECAST CONCERNS ARE ON WINDS FRIDAY...PRECIPITATION CHANCES LATE FRIDAY THROUGH SATURDAY...AND PRECIPITATION CHANCES AGAIN EARLY NEXT WEEK. SYNOPTIC OVERVIEW... MODELS ARE IN GOOD AGREEMENT THAT THE UPPER AND SURFACE LOWS OVER WESTERN SOUTH DAKOTA FRIDAY MORNING WILL CONTINUE LIFTING NORTH-NORTHEAST...AND BEGIN PHASING FRIDAY NIGHT WITH THE NORTHERN STREAM TROUGH CURRENTLY OVER BRITISH MARCHING EAST. AS THIS PHASING OCCURS...THE SYSTEMS COLD FRONT LOOKS PROGGED TO MOVE THROUGH THE FORECAST AREA LATE FRIDAY NIGHT INTO SATURDAY. ANOTHER SHORTWAVE TROUGH LOOKS TO MOVE INTO THE AREA LATE SATURDAY BUT LITTLE IMPACT IS SUGGESTED WITH IT. ATTENTION THEN FOCUSES BACK WEST AS ANOTHER DEEP UPPER TROUGH IS PROGGED TO DEVELOP OVER THE WESTERN U.S.. ECMWF/GFS/CANADIAN AND THEIR RESPECTIVE ENSEMBLES ARE COMING INTO BETTER AGREEMENT OF THIS UPPER TROUGH EJECTING EASTWARD SLOWLY TOWARDS THE FORECAST AREA MONDAY NIGHT THROUGH WEDNESDAY. A RELATIVELY STRONG SURFACE SYSTEM LOOKS TO ACCOMPANY THIS TROUGH...SETTING UP A GOOD CHANCE OF RAIN DURING THIS PERIOD...ESPECIALLY MONDAY NIGHT AND TUESDAY. DETAILS... WINDS ON FRIDAY REMAIN IN FOCUS AS A TIGHT PRESSURE GRADIENT IS FORECAST OVER THE AREA AHEAD OF THE DAKOTAS LOW. THE BEST JUXTAPOSITION OF HIGHEST PRESSURE GRADIENT MAGNITUDE AND MIXING APPEARS TO OCCUR OVER SOUTHEAST MN. MOMENTUM TRANSFER FROM SOUNDINGS SUGGEST GUSTS OVER THE HIGHER TERRAIN OF SOUTHEAST MN OF 35 KT...AND PERHAPS BRIEFLY UP TO 40 KT. THUS...THE CONCERN FOR A MARGINAL WIND ADVISORY PERSISTS. ELSEWHERE...GUSTS OF 25-30 KT SEEM REASONABLE. THESE WINDS OUT OF THE SOUTH HELP TO ADVECT IN 925MB TEMPS OF 16-18C...ALLOWING HIGH TEMPERATURES TO END UP SLIGHTLY WARMER THAN TODAY. NEXT CONCERN IS ON PRECIPITATION CHANCES. A WARM CONVEYOR BELT OF PRECIPITATION AHEAD OF THE LOW SHOULD BE LIFTING THROUGH WESTERN PORTIONS OF IOWA AND MINNESOTA FRIDAY MORNING. ALL INDICATIONS... MINUS THE 10.00Z ECMWF...ARE THAT THIS BELT OF PRECIPITATION WILL FALL APART AS IT PUSHES TOWARDS THE FORECAST AREA FRIDAY AFTERNOON...RESULTING FROM RUNNING INTO DRIER AIR AND THE DYNAMIC FORCING LIFTING NORTH. THE ECMWF HOLDS PRECIPITATION TOGETHER TO AFFECT SOUTHEAST MN AND NORTHEAST IA. FOR NOW HAVE KEPT FRIDAY MOSTLY DRY FROM THE PREVIOUS FORECAST...BUT INTRODUCED A SPRINKLES MENTION. AN INCREASE IN CLOUDS IS LIKELY LATER IN THE DAY NO MATTER WHAT. THERE IS GOOD MODEL AGREEMENT FRIDAY NIGHT AND ESPECIALLY ON SATURDAY THAT A BAND OF SHOWERS WILL FORM AROUND THE COLD FRONT MARCHING EAST. THIS PRECIPITATION IS A RESULT OF MID LEVEL FRONTOGENESIS FORCING AND A STREAM OF 1-1.3 INCH PRECIPITABLE WATER VALUES ADVECTING NORTH PROVIDING MOISTURE. THE FORECAST PROBLEM IS WHERE THE PRECIPITATION ENDS UP AS MODELS DIFFER ON FRONTAL TIMING. TIMING OF THE FRONT TO GET THROUGH THE ENTIRE AREA VARIES FROM 12Z SATURDAY ACCORDING TO THE 10.00Z NAM...15Z SATURDAY FROM THE 10.00Z GFS...18Z SATURDAY FROM THE 10.00Z CANADIAN/ECMWF AND ABOUT 21Z SATURDAY FROM THE 10.00Z UKMET/09.12Z ECMWF. IF THE FRONT ENDS UP SLOWER...THE GREATER THE CHANCE AT LEAST THE SOUTHEAST HALF OF THE FORECAST AREA WILL SEE RAIN. FOR NOW...HAVE STAYED WITH A CONSENSUS APPROACH WHICH RESULTS IN MAXIMUM CHANCES IN THE 30-35 PERCENT RANGE. TEMPERATURES DEFINITELY LOOK COOLER FOR THE WEEKEND AS 925MB READINGS FALL TO 10-13C ON SATURDAY AND 8-10C ON SUNDAY. DRY CONDITIONS ARE LIKELY SATURDAY NIGHT THROUGH AT LEAST MONDAY MORNING AS THE AREA IS UNDER THE INFLUENCE OF HIGH PRESSURE. ATTENTION THEN TURNS TO THE UPPER TROUGH AND LOW PRESSURE SYSTEM COMING OUT OF THE WESTERN U.S. AND PLAINS. PRECIPITABLE WATER VALUES AGAIN CLIMB TO 1-1.3 INCHES OR UP TO 200 PERCENT OF NORMAL AHEAD OF THE SYSTEM. THE COMBINATION OF THIS MOISTURE...FRONTOGENETICAL AND DPVA FORCING WILL ALL COMBINE TO SPREAD PRECIPITATION ACROSS THE UPPER MIDWEST WITH THIS SYSTEM. MODEL TIMING OF THIS PRECIPITATION TO AFFECT THE FORECAST AREA IS REALLY CENTERING ON MONDAY NIGHT AND TUESDAY...THUS HAVE RAISED PRECIPITATION CHANCES CONSIDERABLY FOR THIS TIME PERIOD. MUCAPE IS ALMOST NIL WITH THE SYSTEM...RESULTING FROM NEARLY MOIST-ADIABATIC LAPSE RATES...THUS HAVE KEPT THE MENTION OF THUNDER OUT OF THE FORECAST. THE FORECAST AREA LOOKS TO BECOME AFFECTED BY THE COLD CONVEYOR BELT OF THE SYSTEM TUESDAY NIGHT AND WEDNESDAY...RESULTING IN THE NEED TO CARRY 30-50 PERCENT CHANCES. THESE MAY NEED TO BE RAISED LATER AS THE SYSTEM TRACK FIRMS UP. THERMAL FIELDS ARE WARM ENOUGH TO KEEP THE PRECIPITATION TYPE AS RAIN...BUT WITH 925MB TEMPS DROPPING TO 3-6C ON WEDNESDAY...IT IS GOING TO FEEL MUCH COLDER THAN WHAT WE HAVE SEEN AS OF LATE. && .AVIATION...TODAY AND TONIGHT 704 AM CDT THU OCT 10 2013 MAIN CONCERN FOR AVIATION REMAINS WIND GUSTS...AS VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. WITH LOW PRESSURE ACROSS THE DAKOTAS AND HIGH PRESSURE OVER THE GREAT LAKES...AREA REMAINS IN SOUTHERLY FLOW. GRADIENT NOT QUITE AS STRONG AS THE PAST FEW DAYS SO DO NOT ANTICIPATE WINDS TO BE QUITE AS HIGH TODAY. BUT THAT WILL CHANGE TOMORROW AS THE MAIN SHORT WAVE TROUGH EJECTS THROUGH THE UPPER MIDWEST. ANTICIPATE WIND GUSTS OF 30-40 KTS ON FRIDAY...BUT THAT IS BEYOND THIS TAF PERIOD. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...MW
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1125 AM MST THU OCT 10 2013 .UPDATE...UPDATED AVIATION DISCUSSION. && .SYNOPSIS... A STRONG UPPER LEVEL STORM SYSTEM WILL QUICKLY MOVE THROUGH THE AREA TODAY...RESULTING IN SCATTERED SHOWERS THIS MORNING AND SUBSTANTIALLY COOLER THAN NORMAL TEMPERATURES BY THIS AFTERNOON. DRY CONDITIONS WITH A SLOW WARMING TREND IS EXPECTED TO BEGIN ON FRIDAY...THEN CONTINUE INTO EARLY NEXT WEEK. && .DISCUSSION... THE UPPER LOW THAT HAS BROUGHT OUR CWA MUCH COOLER TEMPERATURES...AND SOME LIGHT RAIN...IS NOW CENTERED JUST WEST OF FLAGSTAFF. THIS LOW IS STILL FORECAST TO MOVE NORTHEASTWARD INTO EXTREME NORTHWEST NEW MEXICO/SOUTHWEST COLORADO BY LATE THIS AFTERNOON. THE SURFACE COLD FRONT HAS NOW MOVED INTO EASTERN ARIZONA WITH MOST OF ITS ASSOCIATED SHOWER ACTIVITY NOW CONFINED TO EXTREME EASTERN MARICOPA COUNTY AND POINTS EAST. SKIES SHOULD BEGIN TO CLEAR OVER THE PHOENIX AREA OVER THE NEXT HOUR OR TWO...WITH MOSTLY SUNNY SKIES EXPECTED BY LATE AFTERNOON. PRECIP AMOUNT ACROSS THE GREATER PHOENIX AREA HAVE BEEN ON THE LIGHT SIDE...MAINLY 0.05 INCH OR LESS...WITH ISOLATED AREAS IN NORTH PHOENIX SEEING AS MUCH AS 0.10 OF AN INCH. OTHER THAN SOME ADJUSTMENTS IN SHORT-TERM TEMPERATURE TRENDS...CURRENT GRIDDED FORECASTS ARE LOOKING QUITE GOOD...NO UPDATES ARE PLANNED AT THIS TIME. && .PREVIOUS DISCUSSION... UPPER LEVEL LOW PRESSURE CONTINUES TO MOVE THROUGH THE AREA THIS MORNING. REGIONAL RADAR MOSAIC INDICATES SHOWERS DEVELOPING ACROSS THE PHOENIX AREA...HOWEVER THE BACK EDGE OF THE BROKEN BAND OF RAINFALL IS ALREADY EXITING SOUTHEAST CALIFORNIA. BASED ON CURRENT TRENDS...I WOULD EXPECT PRECIP TO BEGIN CLEARING OUT OF THE PHOENIX AREA BY MID MORNING /15Z OR SO/...WITH CLEARING SKIES AND DRY CONDITIONS ACROSS THE ENTIRE FORECAST AREA BY MID AFTERNOON. THIS THINKING IS IN LINE WITH PREVIOUS FORECASTS AND CONFIRMED BY THIS MORNINGS 00Z MODEL DATA...AS WELL AS THE LATEST HRRR AND HI-RES SUITE OF WRF MODELS. INHERITED FORECAST WAS ONLY MODIFIED SLIGHTLY TO INCREASE POPS ACROSS THE PHOENIX AREA TO AROUND 40 PERCENT AND TO AROUND 90 PERCENT IN THE MOUNTAINS EAST OF THE METRO. RAINFALL TOTALS HAVE BEEN VERY LIGHT SO FAR...ONLY A FEW HUNDREDTHS OBSERVED ACROSS SOUTHEAST CALIFORNIA AND ONLY A TRACE AT YUMA. HAD THESE VALUES BEEN HIGHER I WOULD CONTEMPLATE MUCH HIGHER POPS ACROSS THE METRO BUT THIS IS SHAPING UP TO BE A WIDESPREAD BUT SHORT LIVED SPOTTY LIGHT RAIN EVENT. AS HAS ALSO BEEN ADVERTISED...THE MOST NOTEWORTHY EFFECT WILL BE SUBSTANTIALLY COOLER TEMPERATURES THIS AFTERNOON. MOST DESERT LOCALES WILL ONLY TOP OUT IN THE LOWER 70S THIS AFTERNOON...ABOUT 15-20 DEGREES BELOW NORMAL FOR OCT 10. THE FORECAST TURNS VERY TRANQUIL ACROSS THE LOWER DESERTS FROM FRIDAY ONWARD AS BROAD NORTHWESTERLY FLOW ESTABLISHES ITSELF ACROSS THE AREA. THIS WILL RESULT IN DRY WEATHER WITH A GRADUAL WARMING TREND THROUGH NEXT WEEK. THE EUROPEAN AND GFS...ALONG WITH THEIR RESPECTIVE ENSEMBLES...INDICATE A LOW MOVING THROUGH NORTHERN ARIZONA LATE THIS WEEKEND WITH A SECONDARY SHORTWAVE TROUGH SWEEPING THROUGH EARLY NEXT WEEK. AT THIS POINT IT WOULD APPEAR ANY IMPACTS THIS FAR SOUTH SHOULD BE MINIMAL/NEGLIGIBLE FOR A COUPLE OF REASONS. THE PROLONGED OVER-LAND TRAJECTORY OF THE LOW WILL RESULT IN EXTREMELY LOW PWATS /ONLY 0.5-0.6 INCHES/ AS THE TROUGH MOVES THROUGH THIS WEEKEND AS WELL AS WITH THE SECONDARY SHORTWAVE. SECOND...THE BEST ISENTROPIC LIFT IS DISPLACED WELL TO THE NORTH OF THE AREA...MORE INTO THE FOUR CORNERS AREA THAN SOUTH-CENTRAL ARIZONA. PERHAPS A SUBTLE INCREASE IN WINDS WITH THE TROUGHS BUT NOTHING OF ANY SIGNIFICANCE. AS MENTIONED BEFORE...TEMPS WILL GRADUALLY RETURN TO NORMAL BY MID WEEK. HIGHS IN THE UPPER 80S WILL BE COMMON ACROSS THE DESERTS ALONG WITH LOWS IN THE LOWER 60S. && .AVIATION... SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL... DEEPER MOISTURE HAS MOVED EAST OF THE PHOENIX AREA...THOUGH RESIDUAL LOW-LEVEL MOISTURE WILL YIELD SCATTERED STRATOCU WITH BASES AROUND 4-5K FT. CLOUDS WILL LIFT AND DISSIPATE LATE THIS AFTERNOON...GIVING WAY TO CLEAR SKIES OVERNIGHT. OTHERWISE...WINDS WILL CONTINUE TO ABATE THIS AFTERNOON...GRADUALLY VEERING TO THE NORTHWEST BEFORE FINALLY BECOMING EASTERLY THIS EVENING. SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH... NO AVIATION WEATHER IMPACTS. LIGHT WINDS AND GENERALLY CLEAR SKIES EXPECTED THROUGH FRIDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... CYCLONIC FLOW WILL PREDOMINATE ACROSS THE INTERMOUNTAIN WEST...RESULTING IN A PERSISTENT WESTERLY FLOW ALONG WITH A DRYING TREND ACROSS THE REGION. MINIMUM HUMIDITIES WILL GENERALLY RANGE FROM THE LOW TO MID TEENS THROUGH THE WEEKEND...LOWERING A FEW PERCENT BY EARLY NEXT WEEK. TEMPERATURES WILL WARM THROUGH THE WEEKEND BEFORE LEVELING OFF NEXT WEEK TO NEAR OR SLIGHTLY BELOW NORMAL READINGS. THERE IS THE POTENTIAL FOR GUSTY NORTH WINDS DOWN THE LOWER COLORADO RIVER VALLEY EARLY NEXT WEEK BUT DUE TO LOWER CONFIDENCE...WILL KEEP VALUES CLOSER TO CLIMATOLOGICAL NORMALS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/LEINS AVIATION....HIRSCH FIRE WEATHER...CB/HIRSCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
301 PM MDT THU OCT 10 2013 .SHORT TERM...UPPER TROF APPROACHING COLORADO FROM THE WEST THIS AFTERNOON AND APPEARS THERE ARE TWO MAIN CIRCULATION CENTERS WITH THE ENTIRE TROF. THE STRONGER ONE IS NOW APPROACHING SW COLORADO WITH A WEAKER CIRCULATION OVER NORTHERN UTAH. SCATTERED SHOWERS AND A FEW THUNDERSTORMS HAVE BEEN DEVELOPING OVER THE MOUNTAINS BUT COVERAGE MORE SCATTERED WITH UNFAVORABLE SOUTH TO SOUTHEAST MTN TOP FLOW. FLOW WILL BECOME MORE FAVORABLE TNT AS MTN TOP FLOW SHIFTS MORE WESTERLY. SNOW PRODUCTION SHOULD INCREASE IN THE MOUNTAINS ALONG WITH STRONG WESTERLY WINDS. HENCE...CURRENT WINTER WEATHER ADVISORIES LOOK GOOD. ACROSS NORTHEAST COLORADO...SURFACE BOUNDARY JUST SHIFTING EAST OF DENVER WITH STRONG SOUTHEAST WINDS OVER THE PALMER DIVIDE AND NORTHEAST PLAINS. STILL A CHANCE FOR SEVERE STORMS ON THE PLAINS WITH STRONG SHEAR PROFILE AND MODERATE INSTABILITY. COULD EASILY SEE HIGH WIND GUSTS GIVEN THE STRONG 50KT MID LEVEL FLOW. HIGHEST CHANCES OF STORMS WILL BE OVER THE FAR PLAINS WITH CONVERGENCE AND BETTER LOW LEVEL MOISTURE NOW INTO WESTERN KANSAS. MAIN CONCERN FOR LATER TNT AND FRIDAY AM IS THE POTENTIAL FOR HIGH WINDS OVER THE FOOTHILLS AND ADJACENT PLAINS. THIS LOOKS LIKE A GOOD CASE FOR HIGH WINDS WITH EJECTING LOW FROM THE DESERT SOUTHWEST. BOTH NAM AND RAP SHOWING CROSS BARRIER FLOW INCREASING 50-60KT AFTER MIDNIGHT TONIGHT ALONG WITH STRONG MTN TOP STABILITY JUST BELOW 700MB. ALSO MEAN STATE CRITICAL LAYER DEVELOPS AS WELL. A FEW FACTORS AGAINST THE WINDS...AS DEEP UPSTREAM MOISTURE MAY LIMIT THE MTN TOP STABILITY AND BEST SUBSIDENCE BEHIND THE TROF IS JUST SOUTH AND EAST OF THE HIGH WIND AREA. ON THE OTHER SIDE...SURFACE GRADIENT INCREASES TO AROUND 15MB FROM GJT TO DEN. BOTTOM LINE...WILL UPGRADE THE WATCH TO WARNINGS FOR THE TARGETED AREA WITH ENOUGH FACTORS IN FAVOR OF HIGH WINDS. .LONG TERM...THE SECONDARY UPPER TROUGH WILL BE MOVING EAST OF THE AREA FRIDAY NIGHT WITH ISOLATED SHOWERS CONTINUING ACROSS THE AREA. AN UPPER RIDGE WILL BUILD OVER THE AREA SATURDAY BRINGING DRIER WEATHER BEFORE ANOTHER WEATHER SYSTEM DIGS INTO THE GREAT BASIN SUNDAY. A SURFACE LOW WILL BE FORMING TO THE NORTH OF THE STATE TO CREATE GUSTY SOUTHERLY WINDS OVER THE PLAINS SATURDAY. SOUTHWEST WINDS ALOFT WILL INCREASE TO BRING IN WARMER AIR SUNDAY BEFORE MOISTURE IS DRAWN UP FROM THE SOUTH TO BRING SHOWERS AND POSSIBLE THUNDERSTORMS OVER THE PLAINS. AT THE SAME TIME...MOISTURE FROM THE INCOMING GREAT BASIN SYSTEM WILL SPREAD SHOWERS OVER THE MOUNTAINS. THE ASSOCIATED COLD FRONT IS PROGGED TO PUSH DOWN ACROSS THE STATE MONDAY AS THE UPPER TROUGH BEGINS TO LIFT NORTHEAST. RAIN SHOWERS OVER THE PLAINS AND SNOW SHOWERS OVER THE MOUNTAINS WILL CONTINUE FROM SUNDAY INTO MONDAY NIGHT...WITH A SLIGHT CHANCE THE RAIN COULD CHANGE INTO SNOW AT LOWER ELEVATIONS MONDAY NIGHT. TUESDAY IS WHEN THE MODELS BEGIN TO DIVERGE WITH THE UPPER TROUGH. ECMWF AND THE CANADIAN MODEL KEEPS A LOW BACK IN THE GREAT BASIN TO ANCHOR THE UPPER TROUGH OVER THE STATE LONGER WHILE THE GFS CONTINUES TO MOVE THE TROUGH SOUTHEAST. WILL KEEP COLDER THAN NORMAL TEMPERATURES AND A SLIGHT CHANCE OF PRECIP IN THE FORECAST WHILE THESE DIFFERENCES ARE RESOLVED. && .AVIATION...SURFACE BOUNDARY HAS PUSHED EAST OF DENVER AS ALL TERMINALS HAVE NOW SHIFTED NORTHWEST. GIVEN THAT SHOWERS WILL BE AROUND THROUGH EARLY EVENING WINDS WILL END UP BEING QUITE VARIABLE AND WILL BE HARD TO PINPOINT SPECIFIC DIRECTIONS BUT MOST LIKELY SOME SORT OF WESTERLY COMPONENT. WEST WINDS WILL INCREASE AT BJC LATER TNT WITH POTENTIAL FOR HIGH WINDS AND GUSTS IN EXCESS OF 50KT. THE WEST WINDS WILL BE LIGHTER AT DEN AND APA WITH SPEEDS UP TO 25KT POSSIBLE. && .HYDROLOGY...NO CONCERNS WITH MAINLY FAST MOVING STORMS THIS AFTERNOON AND EVENING. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM MIDNIGHT MDT TONIGHT THROUGH FRIDAY MORNING FOR COZ035-036-038-039. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON MDT FRIDAY FOR COZ031-033-034. && $$ SHORT TERM...ENTREKIN LONG TERM....KRIEDERMAN AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
335 PM EDT THU OCT 10 2013 .SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER ENERGETIC UPPER LEVEL PATTERN OVER THE CONUS. DEEP AND SHARP TROUGHING IS IN PLACE OVER THE INTER-MOUNTAIN WEST WHICH IS ANCHORED BY A VIGOROUS UPPER LOW NEAR THE 4-CORNERS REGION. QUITE A BIT OF LIGHTNING STILL SHOWING UP WITHIN THE COLD POOL UNDER THE LOW...HIGHLIGHTING THE STRENGTH OF THIS FEATURE. NORTHERN STREAM FLOW THEN RIDGES TO THE NORTH THROUGH THE HIGH PLAINS INTO SOUTH-CENTRAL AND SOUTHEAST CANADA. REMOVED FROM THIS FLOW IS A BROAD TROUGH ALONG THE EAST COAST WITH AN UPPER LOW SPINNING OVER THE DELMARVA REGION. THIS FEATURE AND AN ASSOCIATED SURFACE REFLECTION LOW WILL REMAIN IN PLACE THROUGH THE NEXT COUPLE OF DAYS PROVIDING A WET AND DREARY FORECAST TO THE MID-ATLANTIC STATES. OUR POSITION BEHIND THIS TROUGH AXIS GIVES US A VERY DIFFERENT FORECAST COMPARED TO THOSE AREAS FURTHER TO OUR NORTH. WV IMAGERY SHOWS SIGNIFICANT SUPPRESSION/DRYING WORKING SOUTHWARD OVER THE FLORIDA PENINSULA. IN FACT...THE GFS AND ECMWF CONTINUE SUGGEST THE UPPER LEVEL Q-VECTOR DIVERGENCE WILL ONLY INCREASE WITH TIME INTO TONIGHT OVER OUR FORECAST AREA. 10/12Z RAOBS ACROSS THE STATE SHOWED A STEADY DECREASE IN PW VALUES FROM SOUTH TO NORTH WITH KMFL AROUND 1.7"...KTBW...JUST OVER 1"...AND KJAX DOWN BELOW 1". THESE VALUES ARE BELOW NORMAL...BUT NOT UNHEARD OF FOR MID OCTOBER. HOWEVER...THE COMBINATION OF THE DRIER COLUMN...NO FOCUS MECHANISM...AND THE OVERALL SUPPRESSION OF THE MID/UPPER TROP WILL KEEP OUR FORECAST RAIN FREE THROUGH THE NEXT COUPLE OF DAYS. && .SHORT TERM (TONIGHT THROUGH SATURDAY)... TONIGHT... SKIES BECOME CLEAR QUICKLY WITH THE SETTING OF THE SUN. THE DRY ATMOSPHERE AND CLEAR SKIES WILL ALLOW FOR ANOTHER COMFORTABLY COOL OCTOBER NIGHT INTO EARLY FRIDAY MORNING. LOW TEMPS BY SUNRISE SHOULD REACH DOWN IN THE UPPER 50S/AROUND 60 NORTH OF TAMPA...AND IN THE 60S SOUTH OF THE I-4 CORRIDOR. SOME OF THE COOP MOS SITES ARE SHOWING TEMPERATURES A BIT LOWER THAN WHAT IS CURRENTLY FORECAST. ITS NOT IMPOSSIBLE TO SEE THESE LOWER VALUES...HOWEVER IN GENERAL...UNLESS YOU ARE IN A NEAR IDEAL RADIATIONAL COOLING SETUP (RESERVED MAINLY FOR WINTER HIGH PRESSURE)...THESE COOP VALUES ARE OFTEN BIASED ON THE LOW SIDE. FRIDAY/FRIDAY NIGHT... THE COOL START TO THE MORNING WILL ONLY LEAD INTO YET ANOTHER MAINLY SUNNY AND SEASONABLE DAY TO END OUT THE WORK WEEK. SURFACE HIGH PRESSURE WILL HAVE BECOME ESTABLISHED OVER THE NORTHEAST GULF AND NORTHERN HALF OF THE FL PENINSULA UNDERNEATH A DEEP LAYER NW FLOW ON THE BACKSIDE OF THE EASTERN U.S. TROUGH. THIS NW FLOW WILL CONTINUE TO DELIVER A DRY MID/UPPER LEVEL AIRMASS WITH A LEAST MODEST LEVELS OF SYNOPTIC SUPPRESSION. AS MENTIONED ABOVE THIS WILL LEAD TO A DRY...AND COMFORTABLE DAY WITH HIGH TEMPS RISING INTO THE 80S UNDER MOSTLY CLEAR SKIES IN THE MORNING...AND A MIX OF SUN AND SHALLOW CU FOR THE AFTERNOON. FRIDAY NIGHT MAY BE THE BEST CHANCE TO SEE A FEW NORMALLY COLDER SPOTS UP OVER THE NATURE COAST REACH THE LOWER/MID 50S...DUE TO AN ALMOST NIL GRADIENT. ELSEWHERE IT WILL STILL BE ON THE COOL SIDE (ESPECIALLY AFTER THE LONG SUMMER) WITH MANY INLAND SPOTS IN THE UPPER 50S TO AROUND 60 AND COASTAL SPOTS IN THE 60S. SATURDAY...MORE OF THE SAME. UPPER TROUGH PULLS A BIT FURTHER EAST ALLOWING HEIGHT RISES TO BUILD OVER THE STATE FROM THE GULF OF MEXICO AND NORTHERN GULF COAST. LOOKING LIKE A "CHAMBER OF COMMERCE" TYPE OF DAY TO START OUT THE WEEKEND WITH PLENTY OF SUNSHINE...SEASONABLE TEMPS...AND COMFORTABLE DEWPOINTS. NEAR ZERO CHANCE OF RAIN FOR SATURDAY...SO TRY TO GET OUTSIDE AND ENJOY IT! && .LONG TERM (SUNDAY - THURSDAY)... MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH EARLY NEXT WEEK...WITH SOLUTIONS THEN BEGINNING TO DIVERGE A BIT BY THE MIDDLE AND END OF NEXT WEEK WITH RESPECT TO THE PROGRESSIVENESS OF THE NEXT COLD FRONT. OVERALL...HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER FEATURE THROUGH THE PERIOD...WITH THE POTENTIAL FOR A COLD FRONT TO APPROACH THE REGION LATE NEXT WEEK. MAINLY DRY CONDITIONS ARE EXPECTED...BUT SOME INCREASE IN DEEP LAYER MOISTURE MAY RESULT IN A FEW ISOLATED SHOWERS NEXT WEDNESDAY AND THURSDAY. AS A RESULT...WILL CARRY SLIGHT CHANCE POPS THESE DAYS...WITH RAIN FREE CONDITIONS THROUGH THE REMAINDER OF THE LONG TERM PERIODS. TEMPERATURES ARE EXPECTED TO RUN SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION... FR...WITH OCNL BKN CIGS AOA 035 THROUGH THE AFTERNOON. VFR CONTINUES THROUGH FRI ALTHOUGH THERE MAY BE LIMITED BR AND/OR LOW CIGS....ESPECIALLY LAL AND PGD...LATE NIGHT. WINDS ARE IN THE PROCESS OF SHIFTING TO ONSHORE AT COASTAL TERMINALS FOR THE AFTERNOON. WINDS GO TO NE OR EAST AND DIMINISH SOME OVERNIGHT. && .MARINE... HIGH PRESSURE WILL BUILD OVER THE NORTHEAST GULF OF MEXICO THROUGH THIS EVENING...AND THEN REMAIN IN PLACE THROUGH AT LEAST THE FIRST HALF OF THE UPCOMING WEEKEND. NORTH OF THE WATERS AND REMAIN IN PLACE THROUGH THE WEEKEND. && .FIRE WEATHER... HIGH PRESSURE BUILDS INTO NORTH FLORIDA TONIGHT AND REMAINS IN PLACE THROUGH THE EARLY PORTION OF THE UPCOMING WEEKEND. ENOUGH DRY AIR WILL BE IN PLACE TO RESULT RELATIVE HUMIDITY VALUES APPROACHING OR BRIEFLY DROPPING BELOW CRITICAL LEVELS DURING BOTH FRIDAY AND SATURDAY AFTERNOONS. THE GREATEST POTENTIAL FOR A BRIEF PERIOD WITH RELATIVE HUMIDITY VALUES DROPPING BELOW 35 PERCENT WILL BE ALONG AND NORTH OF THE I-4 CORRIDOR. HOWEVER...ERC VALUES AND DISPERSION INDICES WILL BE WELL BELOW CRITICAL LEVELS AND NO SIGNIFICANT FIRE WEATHER CONCERNS ARE ANTICIPATED. && .PRELIMINARY POINT TEMPS/POPS... TPA 67 86 66 85 / 0 0 0 10 FMY 68 88 66 86 / 0 0 0 10 GIF 64 89 61 86 / 0 0 0 10 SRQ 68 85 65 84 / 0 0 0 10 BKV 58 86 56 86 / 0 0 0 10 SPG 71 85 69 85 / 0 0 0 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/MARINE/FIRE WEATHER...MROCZKA LONG TERM...JELSEMA AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
106 PM CDT THU OCT 10 2013 .DISCUSSION... 322 AM CDT TODAY THROUGH TONIGHT... SIMILAR STORY FOR TODAY...ABUNDANT SUNSHINE AND UNSEASONABLE WARMTH ACROSS THE REGION. BROAD ANTI-CYCLONIC FLOW REMAINS ANCHORED ACROSS THE EASTERN THIRD OF THE CONUS...WITH A WAVE LIFTING NORTHEAST OFF OF THE VIRGINIA COAST. NEAR CLOUDLESS SKIES WITH LIGHT TO CALM WINDS EARLY THIS MORNING ACROSS THE FORECAST AREA. VWP FROM WSR-88D KLOT INDICATE WINDS REMAIN RATHER UNIFORM FROM THE EAST AT 1-9KFT AGL. LOCATIONS ADJACENT TO LAKE MICHIGAN IN FAR NORTHEAST IL CONTINUE TO SEE TEMPS HOLDING IN THE LOW 50S...WHILE FURTHER SOUTH IN THE METRO CHICAGO AREA TEMPS HOVER IN THE MID 50S. ELSEWHERE TEMPS HAVE RADIATED INTO THE LOW/MID 40S...WITH T/TD SPREADS NEARING 2 DEG OR LESS. THE COMBINATION OF MINIMAL T/TD SPREADS AND CALM WINDS HAS ALLOWED PATCHY FOG TO DEVELOP AGAIN THIS MORNING. EXPECT A FEW LOW LYING AREAS TO SEE VSBYS REDUCED TO ARND 1SM...HOWEVER SHOULD ONLY LINGER UNTIL JUST AFTER DAYBREAK. SHORTLY AFT SUNRISE THE SFC SHUD QUICKLY WARM GIVEN THE PAST SEVERAL DAYS OF DRY CONDS. THIS HAS RESULTED IN REDUCED HEAT CAPACITY...AND ATMOSPHERIC PARCELS WILL RESPOND TO THE SOLAR RADIATION IN THE FORM OF A LARGE DIURNAL SWING IN TEMPS TODAY. PLUMES SUGGEST TEMPS WILL BE IN THE MID/UPR 70S FOR MUCH OF THE CWFA...WITH THE EXCEPTION OF AREAS ADJACENT TO LAKE MICHIGAN. AN AFTN LAKE BREEZE IS EXPECTED TO DEVELOP AND PUSH INLAND...WHICH WILL LIKELY CAP TEMPS DOWNTOWN CHICAGO IN THE UPR 60S. TONIGHT DRY WEATHER CONTINUES WITH NEAR CLOUDLESS SKIES YET AGAIN...A FEW CIRRUS CLOUDS MAY SLIDE OVERHEAD WHICH MAY SLOW THE RATE OF COOLING TONIGHT. THUS IT APPEARS TEMPS WILL LIKELY BE SLIGHTLY WARMER IN THE LOW 50S...WITH A FEW TRADITIONAL LOCATIONS RADIATING INTO THE UPR 40S. CONFIDENCE...HIGH. FRIDAY THROUGH SATURDAY... MID-LVL RIDGING CONTINUES TO HANG TOUGH THROUGH MUCH OF FRI...AS THE STRENGTH OF THE 500MB RIDGE OVER QUEBEC/EASTERN ONTARIO REMAINS PROGGED AT 3 SIGMA. GIVEN THE STRENGTH OF THE DOWNSTREAM RIDGE THROUGH FRI NGT...IT APPEARS TO BE HAVING A SIGNIFICANT DIMINISHING ROLE IN THE APPROACHING MID-LVL SHORTWAVE THAT WILL LIFT NORTHEAST FROM THE FOUR-CORNERS REGION. OPERATIONAL GUIDANCE HAS CONTINUED TO TREND DRIER WITH THIS SYSTEM...WITH THE EARLIEST PRECIP NOT ARRIVING UNTIL ARND DAYBREAK SAT. LCL WRF MODEL THRU 12Z SAT INDICATES DRY WEATHER WITH THE FRONTAL BOUNDARY MUCH FASTER AND NEARING FAR NORTHWEST IL ARND DAYBREAK SAT. EC/GFS BOTH HAVE TRENDED DRIER WITH THE EARLY WEEKEND SYSTEM...WITH THE BEST DYNAMICS PASSING WELL NORTHWEST OF THE FORECAST AREA SAT. IT IS CONCEIVABLE THAT SAT MAY JUST SEE SPOTTY SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM SOUTH OF I-80...AS MUCAPE IN THE SFC-500MB LAYER HOVERS ARND 200-400J/KG. THIS TOO HAS BEEN ON A DECREASING TREND. AT THIS TIME HAVE HELD ONTO MENTION OF ISOLATED THUNDER FOR SAT THRU SAT EVE...THEN WITH THE FORWARD SPEED INCREASING FOR SAT NGT HAVE PULLED MENTION OF PRECIP AFT MIDNIGHT. FLOW THEN TURNS NORTHWEST BEHIND THE BOUNDARY...WITH COOLER/DRIER AIR FILTERING INTO THE CWFA FOR THE REMAINDER OF THE WEEKEND. TEMPS FRI AHEAD OF THE SYSTEM WILL LIKELY BE WARM AGAIN...WITH STRONG SOUTHEASTERLY TURNING SOUTHERLY FLOW. MANY PLUMES INDICATE TEMPS WILL BE IN THE MID/UPR 70S FRI...AND COULD PERHAPS SEE A HANDFUL OF POINTS REACH 80 DEGREES SOUTH OF A LASALLE TO KANKAKEE LINE. THEN WITH INCREASED CLOUD COVER FRI NGT TEMPS WILL REMAIN MILD IN THE MID/UPR 50S. DEPENDING ON THE TIMING OF FRONTAL PASSAGE SAT...AND IF CLOUD COVER CAN ERODE QUICK ENOUGH BEFORE SUNSET...TEMPS COULD STILL WARM INTO THE LOW/MID 70S. THE WARMEST LOCATIONS WILL LIKELY BE THE SOUTHEAST CWFA WHERE TEMPS MAY TOUCH 80 DEG SAT AFTN. CONFIDENCE...HIGH. SUNDAY THROUGH WEDNESDAY... ENSEMBLES HAVE CONTINUED TO PROG SLOW WEAKENING IN THE 500MB RIDGE OVER QUEBEC SUN...WITH THE TROUGH OVER THE CENTRAL CONUS FLATTENING. AN ELONGATED TROUGH APPEARS TO SETUP SUN NGT STRETCHING SOUTHWEST THROUGH THE ROCKIES...THEN RIDGING IS POISED TO DEVELOP ACROSS THE PAC-NW MON INTO TUE. THE INCREASING MID-LVL HEIGHTS ACROSS THE PAC-NW/WESTERN CANADA WILL PLAY A ROLE IN A POSSIBLE PATTERN ADJUSTMENT TOWARDS THE MIDDLE OF NEXT WEEK. OPERATIONAL GUIDANCE SLIDES SFC RIDGE INTO THE REGION SUN THRU MON...THEN QUICKLY DRIFTS NORTHEAST MON NIGHT. OPERATIONAL GUIDANCE HAS COME INTO BETTER AGREEMENT WITH A SHORTWAVE LIFTING INTO THE CENTRAL PLAINS MON NGT...WITH CONSIDERABLE MOISTURE BEING PUMPED INTO THIS FEATURE. GUIDANCE THEN BRINGS PRECIP NORTHEAST INTO THE FORECAST AREA MON NGT/TUE. SOME UNCERTAINTY REMAINS WITH RESPECT TO THE TIMING/COVERAGE OF PRECIP...HOWEVER CONCEPTUALLY THIS SYSTEM WOULD LIKELY PRODUCE A DECENT SLUG OF PRECIP TUE BEFORE A DRY SLOT PIVOTS EAST TUE NGT/WED. THE OVERALL THEME WITH TEMPS IN THE EXTENDED PERIODS IS MORE OF A SEASONAL SETUP...HOWEVER TEMPS COULD REMAIN MUCH COOLER IF ABUNDANT PRECIP DOES DEVELOP. THIS COULD HOLD TEMPS IN THE MID/UPR 50S...AT THIS POINT HAVE HELD ONTO TEMPS IN THE LOW/MID 60S. THEN TOWARDS THE MIDDLE OF NEXT WEEK WITH THE AFOREMENTIONED RIDGING ACROSS THE PAC-NW/WESTERN CANADA REMAINING IN PLACE...THIS WILL LIKELY PROVIDE COOLER AIR TO SLIDE SOUTHEAST ACROSS CENTRAL CANADA AND PUSH IN BEHIND THE EARLY WEEK SYSTEM INTO THE CWFA WED. HIGHS WED MAY STRUGGLE TO WARM BEYOND THE MID 50S. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * WEAK LAKE BREEZE ALONG/JUST INLAND OF SHORE AT MIDDAY TO CONTINUE TO MOVE INLAND AND PASS BY KMDW AND KORD DURING THE EARLY TO MID AFTERNOON. TRS //DISCUSSION...UPDATED 18Z... * WEAK PRESSURE GRADIENT TO REMAIN ACROSS THE REGION THROUGH TONIGHT. CONTINUED SURFACE HEATING DESPITE SOME PATCHES OF THICKER CIRRUS MOVING OVERHEAD WILL RESULT IN ADVANCEMENT OF A WEAK LAKE BREEZE INLAND DURING THE AFTERNOON. TRS //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH TRS //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... * FRIDAY NIGHT...DRY/VFR. * SATURDAY...CHANCE OF SHRA/SLIGHT CHANCE OF TSRA. COLD FRONT/WIND SHIFT TO THE WEST BY EARLY AFTERNOON. * SUNDAY AND MONDAY...DRY/VFR. * TUESDAY AND WEDNESDAY...CHANCE OF SHRA. && .MARINE... 106 PM CDT LOW PRESSURE OVER THE CENTRAL HIGH PLAINS WILL RAPIDLY DEEPEN AS IT LIFTS NORTH INTO THE NORTHERN PLAINS FRIDAY...THEN CONTINUES NORTH TO HUDSON BAY OVER THE WEEKEND. THE STRONG LOW WILL RESULT IN STRENGTHENING SOUTHERLY FLOW FRIDAY INTO FRIDAY NIGHT BEFORE GRADIENT WEAKENS AS THE LOW LIFTS FARTHER NORTH AWAY FROM THE LAKE THIS WEEKEND AND WINDS SHIFT TO THE WEST. PUSH OF COLD AIR BEHIND THE SYSTEM IS WEAK AND HIGH PRESSURE WILL MOVE QUICKLY IN RESULTING IN QUICKLY DIMINISHING WINDS/WAVES BEHIND THE FRONT. ANOTHER STRONG LOW PRESSURE IS FORECAST TO DEVELOP OVER THE PLAINS EARLY NEXT WEEK BEFORE MOVING INTO THE GREAT LAKES REGION TUESDAY. THERE ARE STILL DIFFERENCES IN THE MODELS WITH RESPECT TO INTENSITY AND TRACK...BUT GROWING CONSENSUS WOULD SEEM TO SUPPORT INCREASING WINDS AND BUILDING WAVES BY TUESDAY INTO WEDNESDAY. IZZI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1246 PM CDT Thu Oct 10 2013 .DISCUSSION... ISSUED 1038 AM CDT Thu Oct 10 2013 High pressure ridge extending back from the eastern Great Lakes into the Midwest this morning. Very few clouds associated with a small stretch of moisture creeping into the llvls. Other than a few clouds...not much in the way of weather to speak of in the short term. Somewhat variable and light winds in the absence of a strong gradient...though south-southwesterly is the predominant direction. Forecast on track, but will update the grids for a quicker diurnal warm up this morning, and send update to eliminate the morning fog wording in the southern tier. && .AVIATION... ISSUED 1241 PM CDT Thu Oct 10 2013 Increased RH at and below 850mb resulting in a cloud deck this afternoon around 4kft. Diurnal enhancement...so expect a slight lift and sct out before sunset...and a lowering when the inversion sets up tonight. Some vis reduction possible in DEC closer to the richer boundary layer moisture in the SE. Hesitate to go too far north with the BR mention for now. Bringing back the BKN deck mid morning. Light south/southeasterly flow through today and the overnight. VFR for much of the forecast with a tempo drop to MVFR vis toward dawn. HJS && .PREV DISCUSSION... ISSUED 305 AM CDT Thu Oct 10 2013 SHORT TERM...Today through Saturday Gradual moisture advection from the south over the past 24 hours has resulted in 50+ surface dewpoints spreading northward into southern Illinois early this morning. Due to the increased low-level moisture and nearly calm winds beneath ridge axis, areas of fog are beginning to develop south of I-70. HRRR shows the fog developing/spreading further north toward dawn. Have therefore included patchy fog along and south of a Jacksonville to Paris line through 14z/9am. Once early morning fog dissipates, partly to mostly sunny skies and very warm conditions will prevail for the remainder of the day. Afternoon high temperatures will be a degree or two warmer than yesterday, with readings reaching the middle to upper 70s. As ridge only slowly shifts eastward, the potential exists for more patchy fog tonight. Given increasing moisture, clear skies, and continued light winds near the departing ridge axis, will include fog mention for the eastern half of the KILX CWA. Further west, light return flow should keep atmosphere mixed just enough to prevent fog west of I-55. Once fog dissipates, another mostly sunny and warm day will unfold on Friday...with highs reaching the 80-degree mark. 00z Oct 10 models have sped up the approach of the weekend system, with FROPA now expected to occur Saturday afternoon. NAM is the fastest of the models, but think it is too aggressive with pushing the front eastward into the prevailing upper ridge. Will therefore trend closer to the slightly slower ECMWF/GFS solution. With front expected to be along the Mississippi River by 12z Saturday, will maintain low chance POPs in the Illinois River Valley late Friday night, then will spread rain chances further east across the rest of the area on Saturday. With best upper support remaining well to the N/NW and only a shallow moisture profile in place, am not expecting a widespread soaking rainfall on Saturday. Will keep POPs in the chance category accordingly. Since system is moving a bit faster than previously forecast, will only hold on to chance POPs across the eastern CWA into the evening hours, then will go dry across the board overnight. LONG TERM...Sunday through Wednesday High pressure will build into the region behind the departing cold front on Sunday, with models indicating a very dry airmass with dewpoints in the lower to middle 40s settling in. Mostly clear and dry weather is expected for both Sunday and Monday, with warm afternoon highs in the upper 60s/lower 70s and cool overnight lows in the 40s. Next system is still slated to come into the picture early next week, although details are not clear at this point. An upper-level trough is expected to dig into the Rockies Sunday into Monday, although how deep the system becomes and how quickly it lifts northeastward are still very much in question. GFS is more progressive with the system, with the upper low and its associated surface wave ejecting into the western Great Lakes by Tuesday evening. Meanwhile, latest ECMWF is deeper and holds the system back in the Rockies/Plains until Thursday. Given significant timing discrepancies, have opted to leave going forecast alone until better agreement is achieved. As such, am expecting showers and thunderstorms to develop across the area Monday night into Tuesday, followed by cooler/drier weather by Wednesday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1218 PM CDT THU OCT 10 2013 .DISCUSSION... 322 AM CDT TODAY THROUGH TONIGHT... SIMILAR STORY FOR TODAY...ABUNDANT SUNSHINE AND UNSEASONABLE WARMTH ACROSS THE REGION. BROAD ANTI-CYCLONIC FLOW REMAINS ANCHORED ACROSS THE EASTERN THIRD OF THE CONUS...WITH A WAVE LIFTING NORTHEAST OFF OF THE VIRGINIA COAST. NEAR CLOUDLESS SKIES WITH LIGHT TO CALM WINDS EARLY THIS MORNING ACROSS THE FORECAST AREA. VWP FROM WSR-88D KLOT INDICATE WINDS REMAIN RATHER UNIFORM FROM THE EAST AT 1-9KFT AGL. LOCATIONS ADJACENT TO LAKE MICHIGAN IN FAR NORTHEAST IL CONTINUE TO SEE TEMPS HOLDING IN THE LOW 50S...WHILE FURTHER SOUTH IN THE METRO CHICAGO AREA TEMPS HOVER IN THE MID 50S. ELSEWHERE TEMPS HAVE RADIATED INTO THE LOW/MID 40S...WITH T/TD SPREADS NEARING 2 DEG OR LESS. THE COMBINATION OF MINIMAL T/TD SPREADS AND CALM WINDS HAS ALLOWED PATCHY FOG TO DEVELOP AGAIN THIS MORNING. EXPECT A FEW LOW LYING AREAS TO SEE VSBYS REDUCED TO ARND 1SM...HOWEVER SHOULD ONLY LINGER UNTIL JUST AFTER DAYBREAK. SHORTLY AFT SUNRISE THE SFC SHUD QUICKLY WARM GIVEN THE PAST SEVERAL DAYS OF DRY CONDS. THIS HAS RESULTED IN REDUCED HEAT CAPACITY...AND ATMOSPHERIC PARCELS WILL RESPOND TO THE SOLAR RADIATION IN THE FORM OF A LARGE DIURNAL SWING IN TEMPS TODAY. PLUMES SUGGEST TEMPS WILL BE IN THE MID/UPR 70S FOR MUCH OF THE CWFA...WITH THE EXCEPTION OF AREAS ADJACENT TO LAKE MICHIGAN. AN AFTN LAKE BREEZE IS EXPECTED TO DEVELOP AND PUSH INLAND...WHICH WILL LIKELY CAP TEMPS DOWNTOWN CHICAGO IN THE UPR 60S. TONIGHT DRY WEATHER CONTINUES WITH NEAR CLOUDLESS SKIES YET AGAIN...A FEW CIRRUS CLOUDS MAY SLIDE OVERHEAD WHICH MAY SLOW THE RATE OF COOLING TONIGHT. THUS IT APPEARS TEMPS WILL LIKELY BE SLIGHTLY WARMER IN THE LOW 50S...WITH A FEW TRADITIONAL LOCATIONS RADIATING INTO THE UPR 40S. CONFIDENCE...HIGH. FRIDAY THROUGH SATURDAY... MID-LVL RIDGING CONTINUES TO HANG TOUGH THROUGH MUCH OF FRI...AS THE STRENGTH OF THE 500MB RIDGE OVER QUEBEC/EASTERN ONTARIO REMAINS PROGGED AT 3 SIGMA. GIVEN THE STRENGTH OF THE DOWNSTREAM RIDGE THROUGH FRI NGT...IT APPEARS TO BE HAVING A SIGNIFICANT DIMINISHING ROLE IN THE APPROACHING MID-LVL SHORTWAVE THAT WILL LIFT NORTHEAST FROM THE FOUR-CORNERS REGION. OPERATIONAL GUIDANCE HAS CONTINUED TO TREND DRIER WITH THIS SYSTEM...WITH THE EARLIEST PRECIP NOT ARRIVING UNTIL ARND DAYBREAK SAT. LCL WRF MODEL THRU 12Z SAT INDICATES DRY WEATHER WITH THE FRONTAL BOUNDARY MUCH FASTER AND NEARING FAR NORTHWEST IL ARND DAYBREAK SAT. EC/GFS BOTH HAVE TRENDED DRIER WITH THE EARLY WEEKEND SYSTEM...WITH THE BEST DYNAMICS PASSING WELL NORTHWEST OF THE FORECAST AREA SAT. IT IS CONCEIVABLE THAT SAT MAY JUST SEE SPOTTY SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM SOUTH OF I-80...AS MUCAPE IN THE SFC-500MB LAYER HOVERS ARND 200-400J/KG. THIS TOO HAS BEEN ON A DECREASING TREND. AT THIS TIME HAVE HELD ONTO MENTION OF ISOLATED THUNDER FOR SAT THRU SAT EVE...THEN WITH THE FORWARD SPEED INCREASING FOR SAT NGT HAVE PULLED MENTION OF PRECIP AFT MIDNIGHT. FLOW THEN TURNS NORTHWEST BEHIND THE BOUNDARY...WITH COOLER/DRIER AIR FILTERING INTO THE CWFA FOR THE REMAINDER OF THE WEEKEND. TEMPS FRI AHEAD OF THE SYSTEM WILL LIKELY BE WARM AGAIN...WITH STRONG SOUTHEASTERLY TURNING SOUTHERLY FLOW. MANY PLUMES INDICATE TEMPS WILL BE IN THE MID/UPR 70S FRI...AND COULD PERHAPS SEE A HANDFUL OF POINTS REACH 80 DEGREES SOUTH OF A LASALLE TO KANKAKEE LINE. THEN WITH INCREASED CLOUD COVER FRI NGT TEMPS WILL REMAIN MILD IN THE MID/UPR 50S. DEPENDING ON THE TIMING OF FRONTAL PASSAGE SAT...AND IF CLOUD COVER CAN ERODE QUICK ENOUGH BEFORE SUNSET...TEMPS COULD STILL WARM INTO THE LOW/MID 70S. THE WARMEST LOCATIONS WILL LIKELY BE THE SOUTHEAST CWFA WHERE TEMPS MAY TOUCH 80 DEG SAT AFTN. CONFIDENCE...HIGH. SUNDAY THROUGH WEDNESDAY... ENSEMBLES HAVE CONTINUED TO PROG SLOW WEAKENING IN THE 500MB RIDGE OVER QUEBEC SUN...WITH THE TROUGH OVER THE CENTRAL CONUS FLATTENING. AN ELONGATED TROUGH APPEARS TO SETUP SUN NGT STRETCHING SOUTHWEST THROUGH THE ROCKIES...THEN RIDGING IS POISED TO DEVELOP ACROSS THE PAC-NW MON INTO TUE. THE INCREASING MID-LVL HEIGHTS ACROSS THE PAC-NW/WESTERN CANADA WILL PLAY A ROLE IN A POSSIBLE PATTERN ADJUSTMENT TOWARDS THE MIDDLE OF NEXT WEEK. OPERATIONAL GUIDANCE SLIDES SFC RIDGE INTO THE REGION SUN THRU MON...THEN QUICKLY DRIFTS NORTHEAST MON NIGHT. OPERATIONAL GUIDANCE HAS COME INTO BETTER AGREEMENT WITH A SHORTWAVE LIFTING INTO THE CENTRAL PLAINS MON NGT...WITH CONSIDERABLE MOISTURE BEING PUMPED INTO THIS FEATURE. GUIDANCE THEN BRINGS PRECIP NORTHEAST INTO THE FORECAST AREA MON NGT/TUE. SOME UNCERTAINTY REMAINS WITH RESPECT TO THE TIMING/COVERAGE OF PRECIP...HOWEVER CONCEPTUALLY THIS SYSTEM WOULD LIKELY PRODUCE A DECENT SLUG OF PRECIP TUE BEFORE A DRY SLOT PIVOTS EAST TUE NGT/WED. THE OVERALL THEME WITH TEMPS IN THE EXTENDED PERIODS IS MORE OF A SEASONAL SETUP...HOWEVER TEMPS COULD REMAIN MUCH COOLER IF ABUNDANT PRECIP DOES DEVELOP. THIS COULD HOLD TEMPS IN THE MID/UPR 50S...AT THIS POINT HAVE HELD ONTO TEMPS IN THE LOW/MID 60S. THEN TOWARDS THE MIDDLE OF NEXT WEEK WITH THE AFOREMENTIONED RIDGING ACROSS THE PAC-NW/WESTERN CANADA REMAINING IN PLACE...THIS WILL LIKELY PROVIDE COOLER AIR TO SLIDE SOUTHEAST ACROSS CENTRAL CANADA AND PUSH IN BEHIND THE EARLY WEEK SYSTEM INTO THE CWFA WED. HIGHS WED MAY STRUGGLE TO WARM BEYOND THE MID 50S. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * WEAK LAKE BREEZE ALONG/JUST INLAND OF SHORE AT MIDDAY TO CONTINUE TO MOVE INLAND AND PASS BY KMDW AND KORD DURING THE EARLY TO MID AFTERNOON. TRS //DISCUSSION...UPDATED 18Z... * WEAK PRESSURE GRADIENT TO REMAIN ACROSS THE REGION THROUGH TONIGHT. CONTINUED SURFACE HEATING DESPITE SOME PATCHES OF THICKER CIRRUS MOVING OVERHEAD WILL RESULT IN ADVANCEMENT OF A WEAK LAKE BREEZE INLAND DURING THE AFTERNOON. TRS //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH TRS //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... * FRIDAY NIGHT...DRY/VFR. * SATURDAY...CHANCE OF SHRA/SLIGHT CHANCE OF TSRA. COLD FRONT/WIND SHIFT TO THE WEST BY EARLY AFTERNOON. * SUNDAY AND MONDAY...DRY/VFR. * TUESDAY AND WEDNESDAY...CHANCE OF SHRA. && .MARINE... 300 AM...A LARGE RIDGE OF HIGH PRESSURE EXTENDING FROM THE WESTERN LAKES TO NEW ENGLAND WILL SLOWLY DRIFT SOUTHEAST TONIGHT AND FRIDAY AND EVENTUALLY MERGE WITH STRONGER HIGH PRESSURE MOVING SOUTHEAST ACROSS QUEBEC FRIDAY AND FRIDAY NIGHT. THIS WILL MAINTAIN MAINLY SOUTHEASTERLY FLOW OVER THE LAKE INTO FRIDAY WITH SPEEDS GRADUALLY INCREASING INTO THE 10-20 KT RANGE FRIDAY. WEAK LOW PRESSURE NEAR COLORADO THIS MORNING WILL DEEPEN AS IT MOVES NORTH ACROSS THE DAKOTAS FRIDAY AND ACROSS MANITOBA AND WESTERN ONTARIO FRIDAY NIGHT. THIS WILL CAUSE THE GRADIENT TO TIGHTEN ACROSS THE WESTERN LAKES FRIDAY NIGHT INTO SATURDAY MORNING WITH A PERIOD OF 20-25KTS POSSIBLE. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE SATURDAY AFTERNOON OR SATURDAY EVENING SHIFTING WINDS TO THE WEST AND THEN TO THE NORTHWEST SATURDAY NIGHT INTO SUNDAY. HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE LAKES REGION SUNDAY INTO SUNDAY NIGHT. ANOTHER LOW PRESSURE IS EXPECTED TO MOVE FROM THE CENTRAL PLAINS MONDAY ACROSS THE LAKES REGION TUESDAY INTO WEDNESDAY... THOUGH CONFIDENCE REGARDING THE STRENGTH AND TRACK OF THIS SYSTEM REMAINS LOW AT THIS TIME. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO DISCLAIMER: NWS FACEBOOK...TWITTER AND YOUTUBE SITES ARE NOT CONSIDERED OFFICIAL MEANS OF DISSEMINATING WEATHER INFORMATION AND SHOULD NOT BE COUNTED ON AS SUCH. OFFICIAL NWS.NOAA.GOV WEB SITES ARE MOST RELIABLE IN PROVIDING TIMELY DELIVERY OF DATA AND PRODUCTS BUT EVEN THESE SOURCES CANNOT BE GUARANTEED DUE TO THE NATURE OF THE INTERNET.
Area Forecast Discussion National Weather Service Lincoln IL 1042 AM CDT Thu Oct 10 2013 .DISCUSSION... ISSUED 1038 AM CDT Thu Oct 10 2013 High pressure ridge extending back from the eastern Great Lakes into the Midwest this morning. Very few clouds associated with a small stretch of moisture creeping into the llvls. Other than a few clouds...not much in the way of weather to speak of in the short term. Somewhat variable and light winds in the absence of a strong gradient...though south-southwesterly is the predominant direction. Forecast on track, but will update the grids for a quicker diurnal warm up this morning, and send update to eliminate the morning fog wording in the southern tier. HJS && .AVIATION... ISSUED 629 AM CDT Thu Oct 10 2013 VFR conditions will continue next 24hrs at all TAF sites. Lower level moisture streaming up into the area currently and will continue through the day and into tonight. Sct to broken clouds around 4kft being reported in the obs and satellite shows this as well. Based on satellite loop and obs, will have broken cigs at all sites except for PIA during the day. Then all sites will scatter out for this evening with scattered clouds continuing overnight tonight. Winds will be southerly to southeasterly through the whole period. Winds speeds strongest during the day at 7-8kts but then decrease some after sunset. Auten && .PREV DISCUSSION... ISSUED 305 AM CDT Thu Oct 10 2013 SHORT TERM...Today through Saturday Gradual moisture advection from the south over the past 24 hours has resulted in 50+ surface dewpoints spreading northward into southern Illinois early this morning. Due to the increased low-level moisture and nearly calm winds beneath ridge axis, areas of fog are beginning to develop south of I-70. HRRR shows the fog developing/spreading further north toward dawn. Have therefore included patchy fog along and south of a Jacksonville to Paris line through 14z/9am. Once early morning fog dissipates, partly to mostly sunny skies and very warm conditions will prevail for the remainder of the day. Afternoon high temperatures will be a degree or two warmer than yesterday, with readings reaching the middle to upper 70s. As ridge only slowly shifts eastward, the potential exists for more patchy fog tonight. Given increasing moisture, clear skies, and continued light winds near the departing ridge axis, will include fog mention for the eastern half of the KILX CWA. Further west, light return flow should keep atmosphere mixed just enough to prevent fog west of I-55. Once fog dissipates, another mostly sunny and warm day will unfold on Friday...with highs reaching the 80-degree mark. 00z Oct 10 models have sped up the approach of the weekend system, with FROPA now expected to occur Saturday afternoon. NAM is the fastest of the models, but think it is too aggressive with pushing the front eastward into the prevailing upper ridge. Will therefore trend closer to the slightly slower ECMWF/GFS solution. With front expected to be along the Mississippi River by 12z Saturday, will maintain low chance POPs in the Illinois River Valley late Friday night, then will spread rain chances further east across the rest of the area on Saturday. With best upper support remaining well to the N/NW and only a shallow moisture profile in place, am not expecting a widespread soaking rainfall on Saturday. Will keep POPs in the chance category accordingly. Since system is moving a bit faster than previously forecast, will only hold on to chance POPs across the eastern CWA into the evening hours, then will go dry across the board overnight. LONG TERM...Sunday through Wednesday High pressure will build into the region behind the departing cold front on Sunday, with models indicating a very dry airmass with dewpoints in the lower to middle 40s settling in. Mostly clear and dry weather is expected for both Sunday and Monday, with warm afternoon highs in the upper 60s/lower 70s and cool overnight lows in the 40s. Next system is still slated to come into the picture early next week, although details are not clear at this point. An upper-level trough is expected to dig into the Rockies Sunday into Monday, although how deep the system becomes and how quickly it lifts northeastward are still very much in question. GFS is more progressive with the system, with the upper low and its associated surface wave ejecting into the western Great Lakes by Tuesday evening. Meanwhile, latest ECMWF is deeper and holds the system back in the Rockies/Plains until Thursday. Given significant timing discrepancies, have opted to leave going forecast alone until better agreement is achieved. As such, am expecting showers and thunderstorms to develop across the area Monday night into Tuesday, followed by cooler/drier weather by Wednesday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
146 PM MDT THU OCT 10 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 145 PM MDT THU OCT 10 2013 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW STRONG TROUGH WITH CLOSED CENTER JUST WEST OF FOUR CORNERS REGION...AND SOUTH-SOUTHWEST FLOW OVER EASTERN COLORADO/WESTERN KANSAS. 120-125KT H3 JET STREAK IS ROUNDING THE BASE OF THE TROUGH WITH NOSE OF JET STREAK BEGINNING TO MOVE INTO SOUTHERN COLORADO. AT THE SURFACE A STATIONARY FRONT HAS LINGERED OVER NW KS THROUGH MOST OF THE DAY...WITH LATEST OBS TRENDS INDICATING THE FRONT HAS FINALLY PUSHED NORTH OF KGLD TOWARDS THE NORTHWEST PART OF OUR CWA. UPPER LEVEL TROUGH IS EXPECTED TO MOVE NORTHEAST BECOMING NEGATIVELY TILTED OVER NORTHEAST COLORADO/SOUTHWEST NEBRASKA BY 06Z WITH BEST FORCING AHEAD OF THIS FEATURE. MODELS ARE STILL IN AGREEMENT THAT BEST FORCING OVER OUR CWA WILL BE THIS EVENING WITH STRONG SUBSIDENCE AND DRY SLOT MOVING OVER THE CWA BETWEEN 06Z-03Z. FORECAST INITIATION MAY BE SLOWER THAN ORIGINALLY THOUGHT THIS AFTERNOON DUE TO HIGH CINH AND WEAK LOW LEVEL MOISTURE RETURN LIMITING CAPE EARLY THIS AFTERNOON. THERE HAS BEEN SOME VIRGA APPARENT ON RADAR...HOWEVER MAIN ACTIVITY LIKELY WONT GET GOING UNTIL CLOSER TO 00Z. MODELS MAY BE TOO HIGH ON TD WITH LOW LEVEL AIR MASS LIKELY ORIGINATING OVER THE TX/OK PANHANDLES WHERE TD VALUES RANGE FROM THE 40S TO LOW 50S. THIS WILL IMPACT HOW MUCH CAPE WILL BE AVAILABLE OVER THE CWA. AT THIS POINT RAP SOLUTION OF 500-600 J/KG ML CAPE SEEMS TO BE THE MOST REASONABLE...THOUGH I WOULDNT RULE OUT EASTERN LOCATIONS GETTING HIGHER ELEVATED INSTABILITY AFTER 00Z. WITH LOW LEVEL LAPSE RATES CONTINUING TO STEEPEN THIS AFTERNOON WE SHOULD SEE SHOWER/THUNDERSTORM DEVELOPMENT ALONG KS/CO BORDER WHERE CONVERGENCE ALONG FRONT/SURFACE TROUGH WILL PROVIDE FORCING. BETTER COVERAGE WILL BE ASSOCIATED WITH INCREASING LARGE SCALE SUPPORT FROM UPPER TROUGH WHICH SHOULD MOVE INTO THE CWA AROUND 00Z FROM THE WEST. MODELS CONTINUE TO INDICATE SHOWERS/THUNDERSTORMS FORMING INTO A LINE OR MULTI-CELL CLUSTER BY THIS EVENING AND QUICKLY MOVING EAST...WHICH IS REASONABLE CONSIDERING THE UNIDIRECTIONAL SHEER PROFILES IN PLACE. I STILL EXPECT WIND TO BE THE PRIMARY THREAT WITH THUNDERSTORMS...THOUGH IF WE CAN GET AN ORGANIZED/DISCREET CELL THEN SEVERE HAIL WILL CERTAINLY BE POSSIBLE. REGARDING WINDS...WIND SPEEDS HAVE BEEN CLOSE TO ADVISORY CRITERIA IN THE WEST AND WITH LEE TROUGH STILL DEEPENING I EXPECT MOST LOCATIONS IN OUR CWA TO REACH CRITERIA BY LATE THIS AFTERNOON. GFS/MAV GUIDANCE STILL SUPPORTS NEAR WARNING CONDITIONS...WHICH IS PROBABLY TOO WINDY CONSIDERING EXPECTED MIXING HEIGHTS. UNLESS WE SEE A SHOWER/THUNDERSTORM MIX WINDS FROM ABOUT 700-750MB I THINK WE SHOULD REMAIN BELOW WARNING CRITERIA. THIS WILL NEED TO BE MONITORED. WINDS SHOULD DIMINISH AROUND 03Z THOUGH THEY WILL REMAIN BREEZY THROUGH FRIDAY. NW WINDS WILL INCREASE BEHIND UPPER LOW FRIDAY AFTERNOON...AND COULD APPROACH ADVISORY CRITERIA ACROSS THE NORTH. BASED ON CURRENT GUIDANCE IT APPEARS THE STRONGEST WINDS WILL REMAIN NORTH OF OUR CWA...SO NO ADVISORY IS PLANNED FOR FRI AFTERNOON AT THIS TIME. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 1239 PM MDT THU OCT 10 2013 A SECONDARY VORT LOBE ROTATING THROUGH NORTHERN COLORADO FRIDAY NIGHT MIGHT BE ENOUGH TO PRODUCE A FEW ISOLATED LIGHT RAIN SHOWERS...BUT FORCING WILL BE WEAK AND MOISTURE LACKING. LOW LEVEL RETURN FLOW GETS UNDERWAY ON SATURDAY WITH INCREASING SOUTHEASTERLY WINDS. TEMPERATURES SHOULD REBOUND QUICKLY AND RAISED HIGHS AS MUCH AS ISC ALLOWED. AS THE NEXT SYSTEM ORGANIZES IN THE GREAT BASIN...A SERIES OF SHORTWAVE TROUGHS WILL EJECT OUT AHEAD OF IT ACROSS THE CENTRAL ROCKIES AND ADJACENT PLAINS. THERE WILL BE LOW CHANCES OF SHOWERS AND ISOLATED THUNDERSTORMS BEGINNING AND SUNDAY BUT INCREASING SUNDAY NIGHT AND MONDAY AS THE MAIN ENERGY APPROACHES. BREEZY TO WINDY CONDITIONS WILL DEVELOP BOTH SUNDAY AND MONDAY WHICH MAY REQUIRE HIGHLIGHTS. MODELS IN VERY POOR AGREEMENT ON EVOLUTION OF THAT SYSTEM PAST MONDAY...THE ECMWF MUCH SLOWER TO KICK IT OUT COMPARED TO THE PROGRESSIVE GFS SOLUTION. AS A RESULT...THERE WILL BE SOME LINGERING LOW POPS THROUGH THE REMAINDER OF THE PERIOD. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH MONDAY...FOLLOWED BY BELOW NORMAL TUESDAY THROUGH THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1122 AM MDT THU OCT 10 2013 VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS...THOUGH MVFR CONDITIONS COULDNT BE RULED OUT IF A HEAVIER SHOWER/THUNDERSTORM DEVELOPS AT EITHER SITE. GUSTY WINDS WILL CONTINUE TO INCREASE THIS AFTERNOON AND CONTINUE THROUGH THE TAF PERIOD...WITH STRONGEST WINDS LATE THIS AFTERNOON THROUGH THE EARLY PART OF THE EVENING. WINDS WILL START FROM A SOUTHEASTERLY DIRECTION SHIFTING TO THE SOUTH-SOUTHWEST...AND THEN BACKING TO THE NW BY FRIDAY MORNING BEHIND MAIN SYSTEM. SHOWERS/THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND OVERSPREAD BOTH TERMINALS THIS EVENING UPPER LEVEL SYSTEM SHIFTS EAST. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. CO...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR COZ090>092. NE...WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR NEZ079>081. && $$ SHORT TERM...DR LONG TERM...024 AVIATION...DR
AREA FORECAST DISCUSSION
NWS GRAY ME
513 PM EDT THU OCT 10 2013 .SYNOPSIS... HIGH PRESSURE WILL HOLD OVER THE REGION TONIGHT AND FRIDAY. A WEAK BACK DOOR COLD FRONT WILL SLOWLY SAG SOUTHWEST THROUGH THE REGION FRIDAY NIGHT THROUGH SATURDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTHEAST BEHIND THE FRONT SATURDAY NIGHT AND SUNDAY. HIGH PRESSURE WILL GRADUALLY SHIFT OFF TO THE EAST SUNDAY NIGHT AS A COLD FRONT APPROACHES FROM THE NORTHWEST. THE FRONT WILL STALL ACROSS NORTHERN NEW ENGLAND ON MONDAY AND THEN LIFT NORTH AS A WARM FRONT ON TUESDAY. A COLD FRONT WILL APPROACH FROM THE WEST ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... QUIET WEATHER WILL CONTINUE ACROSS THE NORTHEAST AS HIGH PRESSURE REMAINS IN CONTROL. ONLY FLY IN THE OINTMENT IS THE CUTOFF SYSTEM OVER THE MID ATLANTIC STATES WHICH IS CURRENTLY THROWING A FAIR AMOUNT OF HIGH CLOUDINESS ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. HIGH LEVEL MOISTURE WILL CONTINUE TO SPREAD NORTH THROUGH THE REMAINDER OF THE AFTERNOON AND OVERNIGHT BEFORE GRADUALLY RETREATING ON FRIDAY. INCREASING MID LEVEL MOISTURE ACROSS FAR SOUTHERN NEW HAMPSHIRE WILL LIKELY HELP TO KEEP TEMPS UP IN THIS AREA OVERNIGHT. MODELS STILL TRYING TO INTRODUCE SOME LOW CHANCE POPS INTO SOUTHERN NEW HAMPSHIRE OVERNIGHT AND EARLY FRIDAY BUT HAVE SCALED THESE BACK CONSIDERING THE VERY DRY AIRMASS IN PLACE OVER THE REGION. WILL SEE A SLIGHTLY WARMER NIGHT WITH LOWS RANGING THROUGH THE 30S IN THE NORTH AND MID 30S TO MID 40S IN THE SOUTH. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... UPDATE... HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS. DEW POINTS REMAIN RELATIVELY HIGH...SO WILL BE MONITORING FOR POSSIBLE PATCHY FOG IF SKIES CLEAR OVER CENTRAL AND NORTHERN AREAS. LATEST HRRR MODEL CONTINUES TO SHOW ANY PRECIPITATION REMAINING WELL TO OUR SOUTHWEST DURING THE OVERNIGHT HOURS...WITH VERY DRY AIR IN PLACE ACROSS NORTHERN NEW ENGLAND. OTHERWISE...NO SIGNIFICANT CHANGES TO THE FORECAST. PREV DISC... EXPECT FRIDAY TO START OUT WITH MOSTLY CLOUDY SKIES BUT THIS MOISTURE WILL GRADUALLY DIMINISH AS THE DAY GOES ON. SHOULD SEE HIGHS PUSHING ABOVE NORMAL WITH CENTRAL AND NORTHERN AREAS TOPPING OUT IN THE LOWER 70S. EASTERLY FLOW WILL HOLD TEMPS DOWN ALONG THE COAST WITH HIGHS RANGING THROUGH THE 60S. BACKDOOR COLD FRONT APPROACHING FROM THE NORTHEAST WILL PUSH LOW LEVEL MOISTURE INTO THE REGION FRIDAY NIGHT UNDER A FAIRLY SHARP INVERSION. THIS WILL KEEP TEMPS UP ABOVE NORMAL THROUGH THE NIGHT WITH OVERNIGHT LOWS RANGING THROUGH THE 40S. && .LONG TERM /SATURDAY THROUGH THURSDAY/... THE DRY FALL WEATHER WILL CONTINUE THROUGH MUCH OF THE NEXT WEEK. ON THURSDAY MORNING...A RIDGE OF HIGH PRESSURE WAS WELL ESTABLISHED OVER ICELAND. THIS WILL PROVE TO BE A BENEFIT TO NORTHERN NEW ENGLAND AS THE HIGH DEVELOPS INTO A STRONG BLOCKING PATTERN OVER THE EASTERN NORTH ATLANTIC THROUGH THE WEEKEND. THE BROAD RIDGE OF HIGH PRESSURE CURRENTLY OVER OUR AREA HAS NOWHERE TO GO... AND WILL STRENGTHEN IN PLACE THROUGH EARLY NEXT WEEK. SATURDAY A LOW PUSHING THROUGH TO THE SOUTH OF THE REGION IN COMBINATION WITH MOIST AIR FROM THE MARI TIMES WILL DRIVE A WEAK BACK DOOR FRONT INTO COASTAL MAINE AND THE WESTERN MOUNTAINS. EASTERLY ON-SHORE FLOW COULD LEAD TO THE DEVELOPMENT OF PERIODS OF LIGHT DRIZZLE ON THE COAST...ALONG WITH A FEW SHOWERS IN THE INTERIOR BUT ANY WET WEATHER IS SHORT LIVED AS THE HIGH STRENGTHENS FOR THE END OF THE WEEKEND. THE LONG WAVE BLOCKING PATTERN WILL EVENTUALLY BREAK DOWN...RESULTING IN THE TROUGH OVER THE CENTRAL UNITED STATES SHIFTING EASTWARD AND DRAGGING A COLD FRONT THROUGH NEW ENGLAND. AS IS OFTEN THE CASE WITH BLOCKS... THERE IS LOW CONFIDENCE ON THE TIMING OF THIS CHANGE IN THE UPPER LEVEL PATTERN... WITH EACH MODEL RUN COMING IN PROGRESSIVELY LATER IN THE WEEK. I HAVE LEANED ON THE WARMER AND DRIER SIDE FOR EARLY NEXT WEEK... REFLECTING THE TREND TOWARDS A LATER BREAK DOWN OF THE TROUGH. BY WEDNESDAY THE BLOCK WILL BREAK DOWN ALLOWING FOR THE COLD FRONT WHICH HAD BEEN STALLED TO OUR WEST TO SWEEP THROUGH BRINGING WIDESPREAD RAIN WEDNESDAY AND THURSDAY. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... SHORT TERM...VFR TONIGHT THROUGH FRIDAY NIGHT WITH IFR/LIFR CEILINGS AND VSBY IN MORNING VALLEY FOG. LONG TERM... SATURDAY MORNING WILL SEE VALLEY FOG FOR LEB AND HIE WHERE CLEAR SKIES PREVAIL. EAST OF THE MTNS... ONSHORE FLOW WILL KEEP LIFR/IFR CEILINGS IN PLACE THROUGH THE MORNING. CIGS WILL INCREASE TO VFR BY SATURDAY AFTERNOON AND REMAIN VFR THROUGH EARLY NEXT WEEK. && .MARINE... SHORT TERM...NO FLAGS. LONG TERM... MOSTLY QUIET. SEAS WILL BUILD TO 5FT ON THE OUTER WATERS UNDER EAST FLOW FOR SATURDAY...THEN DIMINISH TO 2FT AS THE HIGH BUILDS IN. CONDITIONS WILL REMAIN CALM UNTIL SOMETIME WEDNESDAY WHEN WINDS AND SEAS WILL BUILD TO SCA AHEAD OF THE FRONT. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT THU OCT 10 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 415 PM EDT THU OCT 10 2013 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT UPR RDG DOMINATING THE E HALF OF THE CONUS DOWNSTREAM OF TROF OVER THE W. AT THE SFC...HI PRES EXTENDS FM NEW ENGLAND TO LOWER MI...WITH SW FLOW ARND THIS RDG DOMINATING UPR MI. IN CONCERT WITH VERY DRY LO-MID LVL AIR SHOWN ON THE 12Z GRB/MPX RAOBS...THE CWA IS ENJOYING ANOTHER VERY PLEASANT OCT DAY DESPITE A STREAM OF SCT-BKN CI/CS IN THE SW FLOW ALF BTWN THE ERN RDG/WRN TROF. MORE CLDS ARE PRESENT OVER NW MN AND ONTARIO ALONG A STNRY FNT EXTENDING NE FM LO PRES IN THE NRN PLAINS...BUT THESE CLDS ARE MAKING NO PROGRESS TOWARD THE CWA AND THE DOMINATING UPR RDG. THERE WAS SOME FOG OVER INTERIOR E AND SCENTRAL UPR MI AS WELL AS WI/LOWER MI THIS MRNG...BUT DAYTIME HEATING/MIXING HAS DSPTD THIS FOG. MAIN FCST CONCERNS THRU FRI REMAIN TEMPS AS WELL AS THE POTENTIAL FOR MORE FOG TNGT AS THE UPR RDG/SFC HI PRES/DRY AIRMASS ARE FCST TO REMAIN DOMINANT. TNGT...EXPECT THE LOWEST MIN TEMPS TOWARD THE LO END OF GUIDANCE OVER THE INTERIOR E AND SCENTRAL AGAIN TNGT CLOSER TO FLATTER PRES GRADIENT AND CORE OF DRY AIR WITH PWAT FCST AOB 0.50 INCH EXCEPT OVER THE FAR W...WHERE SHARPER PRES GRADIENT/STRONGER S WIND FARTHER FM HI CENTER WL ALSO LIMIT THE DIURNAL TEMP FALL. EXPANDED FCST AREA OF FOG INTO MUCH OF THE CENTRAL AWAY FM THE LK SUP SHORE WITH UPSLOPE SSE LLVL FLOW OFF LK MI. SUSPECT THE FOG WL BECOME LOCALLY DENSE IN THIS AREA. FRI...AS POTENT SHRTWV LIFTS NEWD OUT OF THE WRN TROF AND THE PRES FALLS IN THE PLAINS...THE GRADIENT OVER UPR MI WL SHARPEN THRU THE DAY...RESULTING IN GUSTY S WINDS WITH MIXING IN THE AFTN. ALTHOUGH THERE WL LIKELY BE AN INCRS IN HI CLDS AT LEAST OVER THE W UNDER THE MORE DIFFLUENT SW FLOW ALF CLOSER TO THE SHRTWV IN THE PLAINS... MODELS SHOW THE LO/MID LYRS REMAINING DRY. WITH FCST H85 TEMPS TO 12C-14C...EXPECT THE MERCURY TO TOP OUT IN THE 70S AGAIN AWAY FM THE MODERATING INFLUENCE OF LK MI IN LLVL SE FLOW. AS HAS BEEN THE CASE IN RECENT DAYS...THE HIEST TEMPS SHOULD OCCUR IN THE DOWNSLOPE AREAS OVER THE W NEAR LK SUP. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 415 PM EDT THU OCT 10 2013 FRI NIGHT...MODELS HAVE MAIN SHORTWAVE AND ASSOC SFC LOW LIFTING FROM THE NORTH DAKOTA INTO SRN MANITOBA AS COLD FRONT MOVES SLOWLY FM CENTRAL MN IN THE EVENING INTO FAR WRN UPPER MI BY 12Z SAT. WEAK DYNAMICS NOTED ALONG THE FRONT INITIALLY AS IT WORKS ITS WAY INTO WRN UPPER MI LATE FRI NIGHT AS BEST Q-VECT CONV WILL PASS WELL TO THE NW ALONG WITH MAIN SHORTWAVE AND SFC LOW. GIVEN RELATIVELY POOR DYNAMICS...LOOK FOR ONLY ISOLD TO SCT SHRA COVERAGE ALONG THE FRONT OVER FAR WRN UPPER MI LATE FRI NIGHT. CURRENT 20-30 PCT POPS SHOULD COVER IT. SAT INTO SAT EVENING...MODELS SHOW TWO SEPARATE SHORTWAVES...ONE FROM THE CENTRAL PLAINS AND A SECOND FROM THE NORTHERN PLAINS EJECTING INTO THE UPPER GREAT LAKES AND ALONG THE COLD FRONT AS IT MOVES ACROSS CENTRAL AND EASTERN UPPER MI. NOT SURPRISINGLY...MODELS SHOW RAIN COVERAGE INCREASING ALONG THE COLD FRONT AS 300K ISENTROPIC ASCENT AND Q-VECT CONV INCREASES AHEAD OF THE SHORTWAVES. GIVEN GOOD MODEL AGREEMENT WITH THESE DETAILS AND FCST PWAT VALUES NEAR 200 PCT OF NORMAL WILL PROBABLY NEED BOOST POPS UP TO HIGH LIKELY TO CATEGORICAL OVER CENTRAL AND ERN COUNTIES. WESTERN COUNTIES SHOULD BE MOSTLY DRY SAT INTO SAT NIGHT AS COLD FRONT AND BEST DYNAMICS WILL BE EAST. LATE SAT EVENING INTO MONDAY...DRIER WEATHER IS IN STORE IN THE WAKE OF THE FRONT AS BROAD SFC HIGH PRESSURE BUILDS IN FM CENTRAL CANADA AND THE NORTHERN PLAINS. HIGHS SUNDAY WILL COOL MAINLY INTO THE 50S CLOSER TO SEASONAL NORMALS...AS W-NW FLOW BRINGS 8H TEMPS OF 0-1C ACROSS THE AREA. SUNDAY NIGHT SHOULD SEE GOOD RADIATIONAL COOLING WITH SFC HIGH OVERHEAD AND SREF MODEL INDICATING PWAT VALUES AOB .50 INCH. WILL FCST TEMPS ON THE LOWER END OF MODEL GUIDANCE CLOSER TO BIAS CORRECTED GEM VALUES. HIGH TEMPS COULD MODERATE A FEW DEGREES ON MONDAY AS NORTHERLY FLOW WEAKENS AND VEERS EASTERLY. TUE INTO THU...MODEL CONSISTENCY DIMINISHES OUT TOWARD THE MIDDLE OF NEXT WEEK...ALTHOUGH GFS/ECMWF AND GEM IN GENERAL AGREEMENT WITH SYSTEM COMING IN FOR TUESDAY. NCEP FAVORED THE ECMWF SOLN WHICH IS SIMILAR TO GEM-NH AND SLOWER THAN GFS DUE IN LARGE PART TO DEEPER TROUGHING EXPECTED OVER SW CONUS AND BLOCKING PATTERN SETTING UP OVER THE EASTERN PACIFIC. FOLLOWING THE SLOWER ECMWF SOLN...BROUGHT IN HIGHER CHC TO LIKELY POPS OVER THE WRN COUNTIES MON NIGHT WITH INCREASING DEEP LYR Q-VECT CONV AND THEN SPREAD HIGH CHC TO LIKELY POPS ACROSS THE CWA ON TUE INTO TUE EVENING AS SFC LOW TRACKS JUST SOUTH OF THE AREA. MAINTAINED SOME HIGHER CHC POPS FOR WED AS COMMA-HEAD MOISTURE ON THE BACKSIDE OF THE LOW PRESSURE SYSTEM COULD LINGER OVER INTO THE AREA. BOTH THE 12Z GFS AND ECMWF SUGGEST SHORTWAVE RDGG AND DRIER CONDITIONS WED NIGHT IN WAKE OF DEPARTING STORM SYSTEM BEFORE ANOTHER SHORTWAVE MOVES IN FROM THE PLAINS ON THU BRINGING ANOTHER CHC OF SHRA. MODELS NOT SHOWING VERY GOOD CONSISTENCY WITH DETAILS OR STRENGTH WITH THU SYSTEM...SO EXPECT THERE WILL BE PLENTY OF FINE TUNING OF FCST YET TO COME FOR LATE NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 121 PM EDT THU OCT 10 2013 WITH DRY HI PRES DOMINATING...EXPECT VFR CONDITIONS TO BE THE RULE THIS TAF PERIOD. THE EXCEPTION WL BE LATE TNGT INTO FRI MRNG AT SAW. WITH A LGT UPSLOPE SSE WIND OFF LK MI UNDER LINGERING MID LVL DRY AIR...OPTED TO INCLUDE A FCST OF FOG/LIFR CONDITIONS FOR THAT LOCATION. DOWNSLOPE NATURE OF THIS FLOW AT CMX/IWD SHOULD LIMIT THE POTENTIAL FOR THIS FOG AT THOSE SITES. A GUSTY S WIND WL DVLP LATER IN THE TAF PERIOD ON FRI AFTN AT IWD WITH ONSET OF DAYTIME HEATING/ MIXING UNDER TIGHTENING PRES GRADIENT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 415 PM EDT THU OCT 10 2013 LIGHT E-SE WINDS WITH HI PRES DOMINATING WILL VEER TO THE S AND INCREASE UP TO 25 KTS ON FRI INTO SAT AS THE PRES GRADIENT TIGHTENS OVER THE UPPER LAKES BETWEEN THE HI CENTER TO THE E AND A DEVELOPING LO IN THE PLAINS. THIS LOW WILL MOVE NE THRU SCENTRAL CANADA INTO HUDSON BAY OVER THE WEEKEND...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR ON SAT. EXPECT A WIND SHIFT TO THE W-NW BEHIND THIS FROPA SAT NIGHT/SUN AND DIMINISHING WINDS AS HI PRES MOVES INTO THE AREA. WINDS ON MON INTO TUE WILL SHIFT TO THE E-NE AS THE HI RETREATS INTO CANADA AND A LO PRES APPROACHES FROM THE PLAINS. WINDS OVER THE WESTERN LAKE MAY INCREASE UP TO 25 KTS BY TUE WITH FAVORABLE TERRAIN ENHANCEMENT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...VOSS AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1244 PM CDT THU OCT 10 2013 .UPDATE... ISSUED AT 1244 PM CDT THU OCT 10 2013 MINOR CHANGES REQUIRED WITH EARLY AFTERNOON UPDATE. MUCH OF SOUTHERN TWO THIRDS OF CWA HAVE CLEARED OUT WITH CIRRUS MOVING IN FROM UPSTREAM...SO HAVE DECREASED SKY THROUGH 00Z FRIDAY. MODELS IN DECENT AGREEMENT WITH PRECIP ASSOCIATED WITH TOMORROWS SYSTEM ENDING AFT 03Z SUN...AND HAVE REMOVED POPS FOR MOST OF SAT NIGHT. NEXT SYSTEM LIFTS INTO SOUTHEASTERN ND ON LATE SUN AFTN AND HAVE ADDED A CHANCE FOR RAIN FROM 21Z SUN TO 00Z MON. NO OTHER CHANGES FOR TONIGHT AND SATURDAY AT THIS TIME AS AWAITING NEWEST SREF AND ECMWF. BIG CHALLENGE WILL BE TIMING PRECIP INTO THE WESTERN CWA...AND HAVE ADDED A CHANCE IN FOR THE UPPER SHEYENNE VALLEY (FROM SLIGHT CHANCE) EARLY IN THE EVENING. UPDATE ISSUED AT 935 AM CDT THU OCT 10 2013 MAIN FORECAST CONCERN THIS MORNING WILL BE WHICH 12Z MODEL INITIALIZES BEST FOR PRECIP STARTING LATE TONIGHT INTO FRI MORNING. 12Z NAM APPEARS TO BE TOO DRY WITH ACTIVITY OVER EASTERN SD WHILE THE LATEST RUC IS TOO AGGRESSIVE IN BRINGING THAT SHOWERY ACTIVITY INTO OUR CWA (TOO EARLY IF AT ALL). SO NO PLANS (FROM LATEST NAM RUN) FOR MAIN SYSTEM WHICH WILL BRING RAIN TO THE AREA TOMORROW. ONLY FCST CHANGE FOR NOW WILL BE TO FURTHER INCREASE SKY BASED ON CURRENT SAT TRENDS...MAINLY ACROSS THE NORTHERN HALF OF CWA. WILL LOOK AT TEMPS CLOSER TO 10 AM BUT NO MAJOR PLANS EXPECTED FOR DAYTIME HIGHS. UPDATE ISSUED AT 641 AM CDT THU OCT 10 2013 MADE A FEW TWEAKS TO CLOUDS AS HIGH AND MID LEVEL CLOUDS CONTINUE TO SPREAD OVER THE AREA ALTHOUGH THERE APPEAR TO BE SOME BREAKS. TEMPS HAVE STAYED IN THE 40S TO LOW 50S AND THINK EVEN WITH HIGH CLOUDS WE SHOULD STILL GET INTO THE 60S AND 70S THIS AFTERNOON. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 345 AM CDT THU OCT 10 2013 TEMPERATURES TODAY AND PRECIP CHANCES TONIGHT AND TOMORROW WILL BE THE MAIN ISSUES FOR THE SHORT TERM. WV LOOP SHOWS THE MAIN UPPER LOW DIGGING FROM SOUTHERN CA INTO AZ...AND THE SYSTEM WILL SWING NORTHEASTWARD INTO THE CENTRAL ROCKIES LATER TODAY. A WEAK LEAD SHORTWAVE HAS BEEN PRODUCING SOME SHOWERS OVER NORTHWESTERN ND...BUT THE UPPER FLOW HAS IT TRACKING INTO CANADA AND STAYING WEST OF US. WILL CONTINUE TO KEEP THE FORECAST DRY THROUGH 00Z. THERE WILL BE PLENTY OF MID AND HIGH CLOUDS IN THE SOUTHWESTERLY FLOW OVER THE NORTHERN PLAINS. INSOLATION WILL BE REDUCED A BIT BUT THERE WILL BE PLENTY OF WARM AIR ADVECTION AS SOUTHEASTERLY WINDS PICK UP AHEAD OF THE SFC LOW TODAY. KEPT HIGHS IN THE UPPER 60S TO MID 70S. THE UPPER LOW WILL BE CLOSING OFF AND MOVING INTO THE SD/NEB REGION TONIGHT. Q VECTOR CONVERGENCE SHOWS THE BEST SUPPORT WITH THE UPPER LOW WILL REMAIN MOSTLY TO OUR SOUTHWEST OVERNIGHT...BUT SOME PRECIP COULD BEGIN TO MOVE INTO THE DEVILS LAKE AREA LATER ON. MADE ONLY MINOR TWEAKS TO THE 30-40 POPS THAT WE HAD GOING FOR OUR WESTERN COUNTIES. THE UPPER LOW WILL BE LIFTING INTO EASTERN ND DURING THE DAY ON FRIDAY...WITH A FAIRLY STACKED SFC LOW TAKING A SIMILAR TRACK. THE MODELS STILL HAVE SOME MINOR DIFFERENCES IN EXACTLY WHERE THEY PUT THE SFC LOW BUT ARE IN BETTER AGREEMENT THAN LAST NIGHT. WITH STRONG UPPER SUPPORT AS THE SYSTEM MOVES INTO THE AREA CONTINUED TO KEEP PRETTY HIGH POPS FOR FRIDAY AS SHOWERS AND THUNDERSTORMS MOVE ACROSS THE AREA IN THE WARM SIDE OF THE SFC LOW. WITH THE VERY STRONG UPPER SYSTEM...THERE IS THE POSSIBILITY OF SOME LOW TOPPED SUPERCELLS IF WE GET THE CAPE THAT THE NAM IS SUGGESTING...AROUND 500 J/KG. MUCH WILL DEPEND ON HOW MUCH CLOUD COVER WE REALLY END UP WITH...AND SOME OF THE MODELS HAVE NOT MUCH SFC INSTABILITY AT ALL. WILL INCLUDE A MENTION IN THE HWO FOR POSSIBILITY OF SEVERE BUT WILL NOT INCLUDE IN GRIDS FOR NOW. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 345 AM CDT THU OCT 10 2013 FRIDAY NIGHT...THE UPPER LOW WILL LIFT OFF INTO CANADA...AND THE COLD FRONT WILL MOVE THROUGH. WITH THE TIGHT PRESSURE GRADIENT WINDS WILL BECOME QUITE STRONG AND BE ASSISTED BY COLD AIR ADVECTION ON THE BACKSIDE OF THE SFC LOW. SO WILL HAVE TO WATCH OUT FOR ADVISORY CRITERIA EVEN AT NIGHT. SHOWERS WILL CONTINUE MAINLY OVER THE NORTHERN CWA AS PRECIP WRAPS AROUND THE BACKSIDE OF THE LOW AS IT LIFTS OUT. THE ECMWF AND GEM KEEP PRECIP A BIT FURTHER WEST INTO SATURDAY WHILE THE DOMESTIC MODELS JUST KEEP SOME ACTIVITY OVER THE NORTHEASTERN COUNTIES. WITH CONVECTIVE TEMPS PRETTY LOW THINK THAT SHOWER ACTIVITY WILL CONTINUE OVER AT LEAST PART OF THE CWA SO KEPT 20-30 POPS GOING FOR A WHILE EVEN AS SFC HIGH PRESSURE BUILDS INTO THE AREA. THE SFC HIGH AND COOL AIR WILL HELP SATURDAY NIGHT DROP BACK INTO THE 30S. SUNDAY TO WEDNESDAY NIGHT...MODELS IN FAIR AGREEMENT WITH THE BEGINNING OF NEXT WEEK BRINGING IN THE NEXT STORM SYSTEM ON MONDAY AND INTO TUESDAY. POPS INCREASED TO LIKELY ACROSS THE S RRV FOR TUESDAY AM AS SHORTWAVE ENERGY MOVES INTO THE E DAKOTAS WHILE THE 500MB TROUGH STAYS POSITIVELY TILTED ACROSS THE FOUR CORNERS TO THE NORTHERN PLAINS. MODEL SOLNS CONTINUE TO AGREE WITH THE MOST QPF ACROSS THE SOUTH WITH VERY LITTLE IN THE NORTHERN HALF OF THE FA. TEMPS TO BE IN THE 50S FOR HIGHS FOR THE FIRST HALF OF THE WEEK...AT TO SLIGHTLY BELOW MID OCT NORMALS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1244 PM CDT THU OCT 10 2013 SCATTERED HIGH CLOUDS THIS AFTERNOON THEN INCREASING AND THICKENING HIGH CLOUD COVER TONIGHT AS LOW PRESSURE MOVES NORTH INTO WESTERN NEBRASKA. LOOK FOR THE SOUTHEAST WIND SHIFT LINE TO CONTINUE TO MOVE NORTH WITH WINDS AT DVL TURNING SOUTHEAST 00Z-02Z PERIOD. OTHER SITES WILL SEE SOUTHEAST WINDS THRU 12Z IN THE 8 TO 15 KT RANGE. WINDS WILL INCREASE QUICKLY AFTER SUNRISE FRIDAY AS SURFACE LOW MOVES TO OUR WEST WITH GUSTS OVER 20 KTS LIKELY OVER THE ENTIRE AREA WITH GUSTS OVER 25 KTS LIKELY DVL-GFK-FAR IN THE 14-18Z PERIOD. SOME SHOWER CHANCE IN TO DVL REGION LATE TONIGHT OR EARLY FRIDAY BUT OTHERWISE MAIN ACTIVITY HOLD OFF TIL PAST 18Z. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...SPEICHER SHORT TERM...JR LONG TERM...JR/JK AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
320 PM CDT THU OCT 10 2013 .VERY SHORT TERM...TONIGHT AND FRIDAY. PATTERN REMAINS ESSENTIALLY UNCHANGED WITH JUST A SLOW APPROACH OF THE TROUGH FROM THE PLAINS. DEW POINTS INCREASING INTO THE 50S ACROSS ILLINOIS AND THIS MOISTURE WILL CONTINUE TO BE DRAWN NORTH. LOW LEVEL RH PROGS HAVE BEEN CONSISTENT IN SHOWING THIS INCREASE IN RH ADVECTING INTO OUR AREA LATER TONIGHT INTO FRIDAY. MAIN CONCERN RESTS WITH HOW EXTENSIVE FOG WILL BE. SREF...WHILE WOEFULLY UNDERFORECASTING FOG LAST NIGHT...IS SHOWING A LITTLE BETTER SIGNAL TONIGHT. HRRR SHOWS SOME FOG MOVING IN FROM THE LAKE AS THE NIGHT WEARS ON. THE 925-950 WINDS ARE A BIT HIGHER THAN LAST NIGHT. OVERALL THE GRADIENT IN THE CWA REMAINS PRETTY WEAK. FOR NOW WILL STICK WITH THE PATCHY FOG IDEA...THOUGH FEEL THE EASTERN CWA MAY BE MORE FAVORED FOR A BIT MORE GIVEN LESS 925/850 WIND SPEEDS AND PROXIMITY TO THE LAKE. WILL PASS ALONG CONCERNS TO THE EVENING SHIFT. WARM AND MILD DAY AFTER THE LINGERING FOG BURNS OFF. 925 TEMPS MODIFY FURTHER INTO THE 15-17C RANGE. THE 925-850 RH SUGGESTS WE MAY END UP WITH AT LEAST A BROKEN CU FIELD WITH THE HIGHER DEW POINTS IN PLACE. ANY FORCING FROM THE SURFACE FRONT OR UPPER TROUGH WILL REMAIN TO OUR WEST. WITH THE PRESSURE GRADIENT TIGHTENING UP...BREEZY SSE WINDS ARE EXPECTED WITH 925 WINDS INCREASING TO 20 TO 30 KNOTS IN THE AFTERNOON. .SHORT TERM...FRIDAY NIGHT THROUGH SUNDAY. SHORT TERM GUIDANCE IN GOOD AGREEMENT ON CARRYING COLD FRONT ACROSS SOUTHERN WISCONSIN LATER FRIDAY NIGHT AND SATURDAY MORNING. COLUMN PRECIPITABLE WATER INCREASES TO OVER ONE INCH AHEAD OF THE FRONT FRIDAY EVENING. WHILE MAIN SHORT WAVE TROUGH REMAINS WELL WEST OF THE AREA...SPOKE OF SHORT WAVE VORTICITY AND WEAKER WARM AIR ADVECTION SWEEP ACROSS THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. MUCAPE INCREASES TO AROUND 200 J/KG. BEST CHANCE FOR SHRA WL BE SATURDAY MORNING ACROSS ERN CWA WHEN LOW LEVEL FORCING ASSOCD WITH FRONT COINCIDES WITH RIGHT ENTRANCE REGION OF PASSING UPPER JET. DRIER AIR SETTLES IN FAIRLY QUICKLY BEHIND FRONT ON SATURDAY AS MAIN SHORT WAVE TROUGH SWEEPS ACROSS WISCONSIN. SFC HIGH PRESSURE SETTLES IN SATURDAY NIGHT. CLEAR SKIES AND 925H TEMPS FAVOR OVERNIGHT LOWS DIPPING INTO THE UPPER 30S TO LOW 40S. FOR NOW WILL HOLD OFF ON MENTIONING FROST IN WESTERN CWA DUE TO BOUNDARY LAYER MIXING BUT WL NEED TO WATCH THOSE OVERNIGHT TEMPS CLOSELY FOR SUNDAY MORNING. .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. SHORT WAVE RIDGING AND DRY EASTERLY FLOW WILL RESULT IN A PLEASANT START TO THE EXTENDED PERIOD...WITH DRY CONDITIONS EXPECTED SUNDAY NIGHT AND MONDAY. INCREASING SOUTHERLY WINDS AHEAD OF AN APPROACHING SHORT WAVE TROUGH WILL BEGIN TO CARRY DEEPER MOISTURE INTO THE AREA MONDAY NIGHT. EXTENDED GUIDANCE IS IN REASONABLE AGREEMENT ON SHORT WAVE TROUGH AND SURFACE SYSTEM AFFECTING SOUTHERN WI MONDAY NIGHT THROUGH MID-WEEK...HOWEVER CONSIDERABLE DIFFERENCES ON STRENGTH OF SYSTEM AS WELL AS TIMING. AT THIS POINT...WL LEAN MORE ON WEAKER SOLUTION THAT GEM AND ECMWF HAVE BEEN GRAVITATING TOWARDS OVER LAST SEVERAL RUNS...CONSIDERING LACK OF UPSTREAM KICKER AND INCREASE OF SIGNIFICANT BAROCLINICITY...AND DISREGARD GFS STRONGER SOLUTION AS MORE OF AN OUTLIER FOR NOW. HENCE SHOWER THREAT SPREADS INTO THE AREA LATER MONDAY NIGHT AND CONTINUES INTO WED. MAY BE A BRIEF PERIOD OF DRY WEATHER AROUND WED NGT...HOWEVER WITH LINGERING UPSTREAM TROF...ANOTHER SHORT WAVE LOOKS TO AFFECT THE AREA ON THURSDAY. THIS SECOND SYSTEM WILL LIKELY USHER COLDER AIR INTO THE AREA WITH AN INCREASING LIKLIHOOD OF FROST/FREEZING TEMPS TOWARD THE END OF NEXT WEEK. GFS 5-DAY 500H MEANS SHOW 150 METER NEGATIVE ANOMOLY SETTING UP OVER THE WESTERN GREAT LAKES CENTERED AT 00Z/18. && .AVIATION /00Z TAFS/...MAIN CONCERN WILL BE FOG REDEVELOPMENT TONIGHT INTO FRIDAY MORNING. 925-850 WINDS WILL BE STRONGER THAN LAST NIGHT THOUGH SURFACE WINDS WILL BE FAIRLY WEAK FROM THE SOUTHEAST. MOS AND HRRR VSBYS HANDLED THINGS PRETTY WELL LAST NIGHT WITH SREF NOT SO GOOD. WILL TREND VSBYS LOWER GIVEN CONSENSUS BETWEEN GFS AND NAM MOS DATA. HIGHER 925-850 RH FIELD SURGES NORTH LATER TONIGHT INTO FRIDAY. THIS CURRENTLY SHOWING ITSELF AS A DIURNALLY DRIVEN CU FIELD CNTRL IL. SO AT THIS TIME WILL NOT FORECAST WIDESPREAD STRATUS WITH THIS INCREASE IN RH. MAIN DYNAMICS AND FRONTAL FORCING FOR SHRA/TSRA ARRIVE FRIDAY NIGHT INTO SATURDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && .CONFIDENCE... TONIGHT AND FRIDAY...MEDIUM. FRIDAY NIGHT AND SATURDAY...MEDIUM. SATURDAY NIGHT AND SUNDAY...MEDIUM TO HIGH. SUNDAY NIGHT AND MONDAY...HIGH. MONDAY NIGHT THROUGH THURSDAY...MEDIUM. $$ VERY SHORT TERM/AVIATION...PC SHORT TERM/LONG TERM...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1228 PM CDT THU OCT 10 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 225 AM CDT THU OCT 10 2013 NO FORECAST CONCERNS FOR THE SHORT TERM PERIOD WITH QUIET WEATHER CONTINUING. CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A NORTHERN STREAM UPPER TROUGH CROSSING BRITISH COLUMBIA...A DEEP UPPER LOW/TROUGH OVER SOUTHERN CALIFORNIA...AND STRONG RIDGING FROM EASTERN TEXAS THROUGH THE EASTERN GREAT LAKES. VERY LITTLE CLOUD COVER TO SPEAK OF FROM THE CENTRAL PLAINS INTO THE FORECAST AREA... EXCEPT FOR A BAND OF CIRRUS ASSOCIATED WITH A SHORTWAVE LIFTING THROUGH WESTERN IA. THE LACK OF CLOUD COVER IS A RESULT OF PLENTIFUL DRY AIR SEEN ON 00Z SOUNDINGS FROM GRB...DVN...MPX...OAX AND DDC. AT THE SURFACE...LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO WHILE HIGH PRESSURE WAS PRESENT OVER LOWER MICHIGAN. THE PRESSURE GRADIENT BETWEEN THESE FEATURES OVER THE FORECAST AREA IS LIGHTER THAN THIS TIME YESTERDAY...RESULTING IN LIGHTER WINDS AND THEREFORE COOLER TEMPERATURES. THE TYPICAL WISCONSIN COLD SPOTS HAVE DROPPED INTO THE UPPER 30S...MEANWHILE HIGHER TERRAIN SITES ALONG AND WEST OF THE MISSISSIPPI RIVER WHICH ARE EXPERIENCING MORE WIND ARE IN THE LOW TO MID 50S. AIRMASS REMAINS ABNORMALLY WARM... THOUGH...WITH 00Z SOUNDINGS SHOWING 925MB TEMPERATURES OF 15-17C EAST TO WEST. THE DRY CONDITIONS WILL CONTINUE FOR ANOTHER 24 HOURS AS THE FORECAST AREA REMAINS SITUATED IN A BLOCKED UPPER LEVEL PATTERN. THAT PATTERN FEATURES THE UPPER LOW IN SOUTHERN CALIFORNIA PROGGED TO EJECT NORTHEASTWARD TOWARDS THE BLACK HILLS OF SOUTH DAKOTA BY 12Z FRIDAY...WHILE STRONG RIDGING HOLDS IN PLACE OVER LOWER MICHIGAN. EXPECT WINDS TO INCREASE...A RESULT OF THE PRESSURE GRADIENT TIGHTENING AHEAD OF THE DEEPENING SURFACE LOW IN COLORADO LIFTING NORTH WITH THE UPPER LOW. THE STRONGER SOUTHERLY WINDS DO NOT BRING ANY WARMER AIR IN FOR TODAY AT 925MB...AS MODEL FORECASTS SUGGESTS 925MB TEMPERATURES END UP AGAIN BETWEEN 16-18C AT 00Z. THUS HIGHS ARE LIKELY TO BE SIMILAR TO THOSE SEEN YESTERDAY. HOWEVER... THE WINDS WILL HELP TO KEEP THE NEAR SURFACE LAYER MORE MIXED TONIGHT...RESULTING IN A WARMER NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 225 AM CDT THU OCT 10 2013 FORECAST CONCERNS ARE ON WINDS FRIDAY...PRECIPITATION CHANCES LATE FRIDAY THROUGH SATURDAY...AND PRECIPITATION CHANCES AGAIN EARLY NEXT WEEK. SYNOPTIC OVERVIEW... MODELS ARE IN GOOD AGREEMENT THAT THE UPPER AND SURFACE LOWS OVER WESTERN SOUTH DAKOTA FRIDAY MORNING WILL CONTINUE LIFTING NORTH-NORTHEAST...AND BEGIN PHASING FRIDAY NIGHT WITH THE NORTHERN STREAM TROUGH CURRENTLY OVER BRITISH MARCHING EAST. AS THIS PHASING OCCURS...THE SYSTEMS COLD FRONT LOOKS PROGGED TO MOVE THROUGH THE FORECAST AREA LATE FRIDAY NIGHT INTO SATURDAY. ANOTHER SHORTWAVE TROUGH LOOKS TO MOVE INTO THE AREA LATE SATURDAY BUT LITTLE IMPACT IS SUGGESTED WITH IT. ATTENTION THEN FOCUSES BACK WEST AS ANOTHER DEEP UPPER TROUGH IS PROGGED TO DEVELOP OVER THE WESTERN U.S.. ECMWF/GFS/CANADIAN AND THEIR RESPECTIVE ENSEMBLES ARE COMING INTO BETTER AGREEMENT OF THIS UPPER TROUGH EJECTING EASTWARD SLOWLY TOWARDS THE FORECAST AREA MONDAY NIGHT THROUGH WEDNESDAY. A RELATIVELY STRONG SURFACE SYSTEM LOOKS TO ACCOMPANY THIS TROUGH...SETTING UP A GOOD CHANCE OF RAIN DURING THIS PERIOD...ESPECIALLY MONDAY NIGHT AND TUESDAY. DETAILS... WINDS ON FRIDAY REMAIN IN FOCUS AS A TIGHT PRESSURE GRADIENT IS FORECAST OVER THE AREA AHEAD OF THE DAKOTAS LOW. THE BEST JUXTAPOSITION OF HIGHEST PRESSURE GRADIENT MAGNITUDE AND MIXING APPEARS TO OCCUR OVER SOUTHEAST MN. MOMENTUM TRANSFER FROM SOUNDINGS SUGGEST GUSTS OVER THE HIGHER TERRAIN OF SOUTHEAST MN OF 35 KT...AND PERHAPS BRIEFLY UP TO 40 KT. THUS...THE CONCERN FOR A MARGINAL WIND ADVISORY PERSISTS. ELSEWHERE...GUSTS OF 25-30 KT SEEM REASONABLE. THESE WINDS OUT OF THE SOUTH HELP TO ADVECT IN 925MB TEMPS OF 16-18C...ALLOWING HIGH TEMPERATURES TO END UP SLIGHTLY WARMER THAN TODAY. NEXT CONCERN IS ON PRECIPITATION CHANCES. A WARM CONVEYOR BELT OF PRECIPITATION AHEAD OF THE LOW SHOULD BE LIFTING THROUGH WESTERN PORTIONS OF IOWA AND MINNESOTA FRIDAY MORNING. ALL INDICATIONS... MINUS THE 10.00Z ECMWF...ARE THAT THIS BELT OF PRECIPITATION WILL FALL APART AS IT PUSHES TOWARDS THE FORECAST AREA FRIDAY AFTERNOON...RESULTING FROM RUNNING INTO DRIER AIR AND THE DYNAMIC FORCING LIFTING NORTH. THE ECMWF HOLDS PRECIPITATION TOGETHER TO AFFECT SOUTHEAST MN AND NORTHEAST IA. FOR NOW HAVE KEPT FRIDAY MOSTLY DRY FROM THE PREVIOUS FORECAST...BUT INTRODUCED A SPRINKLES MENTION. AN INCREASE IN CLOUDS IS LIKELY LATER IN THE DAY NO MATTER WHAT. THERE IS GOOD MODEL AGREEMENT FRIDAY NIGHT AND ESPECIALLY ON SATURDAY THAT A BAND OF SHOWERS WILL FORM AROUND THE COLD FRONT MARCHING EAST. THIS PRECIPITATION IS A RESULT OF MID LEVEL FRONTOGENESIS FORCING AND A STREAM OF 1-1.3 INCH PRECIPITABLE WATER VALUES ADVECTING NORTH PROVIDING MOISTURE. THE FORECAST PROBLEM IS WHERE THE PRECIPITATION ENDS UP AS MODELS DIFFER ON FRONTAL TIMING. TIMING OF THE FRONT TO GET THROUGH THE ENTIRE AREA VARIES FROM 12Z SATURDAY ACCORDING TO THE 10.00Z NAM...15Z SATURDAY FROM THE 10.00Z GFS...18Z SATURDAY FROM THE 10.00Z CANADIAN/ECMWF AND ABOUT 21Z SATURDAY FROM THE 10.00Z UKMET/09.12Z ECMWF. IF THE FRONT ENDS UP SLOWER...THE GREATER THE CHANCE AT LEAST THE SOUTHEAST HALF OF THE FORECAST AREA WILL SEE RAIN. FOR NOW...HAVE STAYED WITH A CONSENSUS APPROACH WHICH RESULTS IN MAXIMUM CHANCES IN THE 30-35 PERCENT RANGE. TEMPERATURES DEFINITELY LOOK COOLER FOR THE WEEKEND AS 925MB READINGS FALL TO 10-13C ON SATURDAY AND 8-10C ON SUNDAY. DRY CONDITIONS ARE LIKELY SATURDAY NIGHT THROUGH AT LEAST MONDAY MORNING AS THE AREA IS UNDER THE INFLUENCE OF HIGH PRESSURE. ATTENTION THEN TURNS TO THE UPPER TROUGH AND LOW PRESSURE SYSTEM COMING OUT OF THE WESTERN U.S. AND PLAINS. PRECIPITABLE WATER VALUES AGAIN CLIMB TO 1-1.3 INCHES OR UP TO 200 PERCENT OF NORMAL AHEAD OF THE SYSTEM. THE COMBINATION OF THIS MOISTURE...FRONTOGENETICAL AND DPVA FORCING WILL ALL COMBINE TO SPREAD PRECIPITATION ACROSS THE UPPER MIDWEST WITH THIS SYSTEM. MODEL TIMING OF THIS PRECIPITATION TO AFFECT THE FORECAST AREA IS REALLY CENTERING ON MONDAY NIGHT AND TUESDAY...THUS HAVE RAISED PRECIPITATION CHANCES CONSIDERABLY FOR THIS TIME PERIOD. MUCAPE IS ALMOST NIL WITH THE SYSTEM...RESULTING FROM NEARLY MOIST-ADIABATIC LAPSE RATES...THUS HAVE KEPT THE MENTION OF THUNDER OUT OF THE FORECAST. THE FORECAST AREA LOOKS TO BECOME AFFECTED BY THE COLD CONVEYOR BELT OF THE SYSTEM TUESDAY NIGHT AND WEDNESDAY...RESULTING IN THE NEED TO CARRY 30-50 PERCENT CHANCES. THESE MAY NEED TO BE RAISED LATER AS THE SYSTEM TRACK FIRMS UP. THERMAL FIELDS ARE WARM ENOUGH TO KEEP THE PRECIPITATION TYPE AS RAIN...BUT WITH 925MB TEMPS DROPPING TO 3-6C ON WEDNESDAY...IT IS GOING TO FEEL MUCH COLDER THAN WHAT WE HAVE SEEN AS OF LATE. && .AVIATION...THROUGH 18Z FRIDAY 1228 PM CDT THU OCT 10 2013 MAIN AVIATION CONCERNS ARE WIND SPEEDS AND GUSTS AT BOTH RST AND LSE TAF SITES AFTER 12Z FRIDAY. VFR CONDITIONS WILL CONTINUE TO PREVAIL THROUGH THE TAF PERIOD. PRESSURE GRADIENT WILL BE MORE RELAXED ACROSS THE REGION THIS AFTERNOON THAN PREVIOUS COUPLE OF DAYS...SOUTHERLY WIND SPEEDS WILL BE IN THE 10 TO 12 KNOT RANGE AT BOTH TAF SITES WITH GUSTS POSSIBLY UP TO 20 KNOTS AT RST THIS AFTERNOON. WINDS WILL DIMINISH THIS EVENING. THEN...PRESSURE GRADIENT TIGHTENS ACROSS THE AREA AFTER 12Z FRIDAY...AS LOW PRESSURE DEEPENS OVER THE DAKOTAS. THIS WILL ALLOW WINDS TO INCREASE TO 15 TO 20 KNOTS WITH GUST 25 TO 30 KNOTS AT BOTH TAF SITES AFTER 12Z FRIDAY. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1127 AM CDT THU OCT 10 2013 .AVIATION/18Z TAFS/...MAIN CONCERN WILL BE FOG REDEVELOPMENT TONIGHT INTO FRIDAY MORNING. 925-850 WINDS WILL BE STRONGER THAN LAST NIGHT THOUGH SURFACE WINDS WILL BE FAIRLY WEAK FROM THE SOUTHEAST. MOS AND HRRR VSBYS HANDLED THINGS PRETTY WELL LAST NIGHT WITH SREF NOT SO GOOD. WILL TREND VSBYS LOWER THAN CURRENT FCST GIVEN CONSENSUS BETWEEN GFS AND NAM MOS DATA. HIGHER 925-850 RH FIELD SURGES NORTH LATER TONIGHT INTO FRIDAY. THIS CURRENTLY SHOWING ITSELF AS A DIURNALLY DRIVEN CU FIELD CNTRL IL. SO AT THIS TIME WILL NOT FORECAST WIDESPREAD STRATUS WITH THIS INCREASE IN RH. SYNOPTICALLY INDUCED CLOUD FIELD WITH APPROACHING TROUGH PROGGD TO REMAIN WEST OF THE AREA THROUGH LATE FRIDAY. PC && .PREV DISCUSSION... /ISSUED 327 AM CDT THU OCT 10 2013/ TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH. PATCHY GROUND FOG WILL PREVAIL EARLY THIS MORNING ESPECIALLY IN THE FAVORED AREAS. OTHERWISE SELY FLOW WILL CONTINUE TODAY AND TNT AS HIGH PRESSURE REMAINS OVER THE ERN GREAT LAKES AND CYCLOGENESIS ENSUES FROM NE CO AND TRACKS TO THE SD/NE BORDER BY 12Z FRI. THIS IS IN RESPONSE TO THE UPPER LOW OVER SRN CA THAT WILL LIFT NEWD TO THE SD/NE BORDER BY 12Z FRI. 925 MB TEMPS IN THE MID TEENS CELSIUS SUGGESTS HIGH TEMPS WILL BE IN THE LOWER 70S INLAND. THE LAKE BREEZE AND SYNOPTIC SELY FLOW WILL DEVELOP EARLIER TODAY THAN YESTERDAY SO EXPECT TEMPS TO BE A LITTLE COOLER OVER THE LAKE COUNTIES. FOR TNT THE SLY FLOW WILL BRING INCREASED AMOUNTS OF LOW LEVEL MOISTURE INTO THE REGION. THIS SHOULD RESULT IN SCT CLOUD COVER AFTER 08Z ALONG WITH PATCHY FOG. FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH. SHORT TERM MODELS IN GOOD AGREEMENT WITH FEATURES DURING THIS PERIOD. DEEP LOW PRESSURE AND ASSOCIATED 500MB LOW WILL SHIFT FROM CENTRAL SOUTH DAKOTA TO EASTERN MANITOBA CANADA FRIDAY AND FRIDAY NIGHT. BREEZY SOUTH SOUTHEAST WINDS WILL KEEP WARM TEMPERATURES ACROSS THE AREA FRIDAY...WITH DRY CONDITIONS. COLD FRONT EXTENDING SOUTHWARD FROM THE LOW PUSHES EAST THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY. WEAK TO MODEST LOW LEVEL FRONTOGENESIS RESPONSE AND Q VECTOR CONVERGENCE IS SEEN WITH THE FRONT. MAIN 500MB SHORTWAVE TROUGH SLIDES THROUGH THE AREA SATURDAY AFTERNOON. AREA FORECAST SOUNDINGS ARE SHOWING GOOD COLUMN MOISTURE LATER FRIDAY NIGHT INTO SATURDAY MORNING. QPF VALUES ARE DECENT ON GFS/CANADIAN/ECMWF...LESS SO ON NAM. CONTINUED WITH HIGH CHANCE POPS FOR THIS PERIOD...AND WOULD NEED TO RAISE THEM LATER ON IF MODELS CONTINUE TO SHOW GOOD AGREEMENT. LEFT SLIGHT CHANCE FOR THUNDER WITH WEAK ELEVATED CAPE. STILL WARM AHEAD OF FRONT WITH SOUTH WINDS. COLD AIR ADVECTION OCCURS BEHIND FRONT LATER SATURDAY INTO SATURDAY NIGHT...WITH HIGH PRESSURE MOVING EASTWARD TOWARD THE REGION. BRISK WEST WINDS SATURDAY AFTERNOON TAPER OFF SATURDAY NIGHT...BRINGING MORE SEASONAL TEMPERATURES FOR SATURDAY NIGHT. SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM. ECMWF AND GFS ARE IN SOMEWHAT BETTER AGREEMENT WITH FEATURES DURING THIS PERIOD. THEY TAKE HIGH PRESSURE EAST ACROSS THE REGION SUNDAY AND SUNDAY NIGHT...THEN EAST OF THE REGION ON MONDAY. THIS SHOULD RESULT IN QUIET WEATHER WITH NEAR NORMAL TEMPERATURES. ECMWF AND GFS ARE IN A BIT MORE OF AN AGREEMENT WITH THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE REGION EARLY NEXT WEEK. THE GFS IS A BIT FURTHER NORTH WITH THE LOW TRACK AND SOMEWHAT STRONGER THAN THE ECMWF. THE GFS TAKES THE LOW FROM SOUTHEAST NEBRASKA AT 00Z TUESDAY TO NEAR LA CROSSE WISCONSIN BY 00Z WEDNESDAY...AND WEAKENS AS IT SHIFTS TO NORTHERN LAKE MICHIGAN BY 00Z THURSDAY. THE ECMWF TAKES IT FROM THE SOUTHERN HIGH PLAINS AT 00Z TUESDAY TO SOUTHEAST WISCONSIN BY 00Z WEDNESDAY...THEN WELL EAST OF THE REGION BY 00Z THURSDAY. GFS TAKES MAIN SHORTWAVE TROUGH EAST THROUGH THE REGION DURING THIS TIME...WITH THE ECMWF TAKING IT THROUGH MAINLY NORTHERN WISCONSIN. MORE DIFFERENCES SHOW UP ON WEDNESDAY...WITH THE GFS KEEPING THE LOW AND 500MB LOW OVER THE REGION WITH QPF...AND THE ECMWF DRY WITH WEAK HIGH PRESSURE. REGARDLESS OF THE MODEL DIFFERENCES...IT LOOKS LIKE A WET PERIOD MONDAY NIGHT INTO WEDNESDAY ACROSS THE AREA. THE BEST CHANCES WOULD BE ON TUESDAY. INCREASED POPS OVER INITIAL MODEL BLEND GIVEN BETTER CONFIDENCE IN THE MODEL TRENDS WITH POPS. TEMPERATURES LOOK TO DROP TO BELOW SEASONAL NORMALS DURING THIS TIME. AVIATION/12Z TAFS/...GROUND FOG WILL AFFECT SRN WI INCLUDING THE TAF SITES THIS AM. VSBYS WILL HAVE A WIDE RANGE FROM 1/4 TO 3 MILES...WHICH IS TYPICAL OF GROUND FOG. MOST OF THE FOG WILL END BY 14Z WITH VFR CONDITIONS AND FEW-SCT HIGH CLOUDS THE REMAINDER OF THE DAY INTO THE EVENING. THIS FOG WILL OCCUR AGAIN MAINLY AFTER 06Z TNT ALONG WITH SCT STRATOCUMULUS AROUND 4 KFT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...GEHRING FRIDAY THROUGH WEDNESDAY...WOOD