Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/18/12


AREA FORECAST DISCUSSION
NWS MIAMI FL
1015 PM EST SAT NOV 17 2012 .UPDATE... NO MAJOR UPDATES TO THE PREVIOUS FORECAST ARE EXPECTED THIS EVENING. THE EVENING SURFACE ANALYSIS SHOWED A LINGERING WEAK TROUGH OR WHAT IS LEFT OF AN OLD FRONTAL BOUNDARY JUST EAST OF THE FLORIDA PENINSULA WITH LIGHT TO MODERATE NORTHEAST FLOW CONTINUING. ENHANCED LOW-LEVEL CONVERGENCE NEAR AND AROUND THIS SURFACE FEATURE COMBINED WITH BELOW AVERAGE MID/UPPER-LEVEL TEMPERATURES WILL MAINTAIN THE CHANCE FOR MAINLY ISOLATED SHOWERS OVER THE ADJACENT ATLANTIC WATERS AND COASTAL AREAS THROUGH THE OVERNIGHT HOURS. SIMILAR TO THE PAST FEW NIGHTS...INLAND FOG WILL BE POSSIBLE THROUGH THE OVERNIGHT HOURS ACROSS THE INTERIOR AREAS. THE LATEST SREF MODEL PROBABILITIES SUPPORT THIS AND INDICATE A GOOD PORTION OF THIS INTERIOR AREA AROUND AND SOUTH OF THE LAKE DIPPING INTO THE 1-3 MILE VISIBILITY RANGE BY DAYBREAK SUNDAY. 85/AG && .PREV DISCUSSION... /ISSUED 644 PM EST SAT NOV 17 2012/ AVIATION... AS A STALLED FRONTAL BOUNDARY LINGERS JUST OFFSHORE THE ATLANTIC COAST...ISOLATED SHOWERS WILL REMAIN ACROSS THE AREA THROUGH THE NIGHT AND IS DEPICTED BY THE LATEST HRRR GUIDANCE. SHOWERS COULD BRIEFLY AFFECT ONE OR MORE EAST COAST SITES THROUGH THE EVENING WITH MVFR CONDITIONS BUT WOULD BE VERY BRIEF AND DECIDED NOT TO PREVAIL ANY SHRA MENTION. MID LEVEL DRYING EXPECTED TO PUSH INTO THE SOUTH FLORIDA PENINSULA FROM THE NORTH THROUGH THE LATTER HALF OF THE PERIOD. PREV DISCUSSION... /ISSUED 246 PM EST SAT NOV 17 2012/ DISCUSSION... SHORT TERM...THE BASIC SYNOPTIC SETUP OVER THE AREA IS A NORTHWESTERLY FLOW OVER THE CWA AS HIGH PRESSURE TO THE NORTH SLOWLY PUSHES A LOW PRESSURE SYSTEM WELL TO THE SOUTHEAST EASTWARD. THERE IS A STALLED BOUNDARY THAT CONTINUES TO LAY ACROSS THE OFFSHORE WATERS IN THE ATLANTIC. THE HIGH, CENTERED OVER NEW ENGLAND, IS VERY SLOWLY CAUSING THE BOUNDARY TO DRIFT TO THE EAST AND HAS PUSHED MOST OF THE SHOWERS AWAY FROM THE CWA. THIS BOUNDARY WILL NOT GO FAR, HOWEVER, AS THERE IS NO REAL PUSH NORMAL TO THE BOUNDARY. RATHER, THE FLOW IS ALMOST PARALLEL TO THE BOUNDARY. SO, WITH STILL PLENTY OF MOISTURE REMAINING OVER THE MAINLAND, DAYTIME HEATING WILL CAUSE SOME ISOLATED SHOWERS TO DEVELOP. MODELS ARE INDICATING MOST OF ANY CONVECTION WILL BE LOCATED MAINLY OFF SHORE. THIS PATTERN WILL BE IN PLACE FOR THE REMAINDER OF THE WEEKEND. OVER THE NEXT COUPLE OF DAYS, THE LOW WILL SLOWLY MOVE TO THE NORTH AS THE HIGH PRESSURE SLIDES WELL TO THE NORTHEAST. THE LOW WILL THEN DEEPEN AND INTERACT WITH THE STALLED BOUNDARY, TURNING IT INTO A COLD FRONT. THIS COULD ALLOW FOR SOME SHOWERS OVER THE ATLANTIC TO DEVELOP, BUT STILL LOOK ISOLATED AT BEST THROUGH 12Z TUESDAY. ALSO, WITH THE LOW DEVELOPING NEXT WEEK, SOMEWHAT COOLER, DRIER AIR WILL TRY TO MAKE ITS WAY DOWN THE FLORIDA PENINSULA. WHILE THE TEMPERATURES WILL ONLY COOL A COUPLE OF DEGREES, THE DEW POINTS SHOULD DROP AROUND 5 DEGREES, ALLOWING THE AIR TO FEEL SOMEWHAT DRIER FOR THE BEGINNING OF THE WEEK. LONG TERM...TUESDAY THROUGH FRIDAY...DRY AND STABLE AIR OVER S FLA TUESDAY PRECLUDES PRECIPITATION EXCEPT FOR THE E COAST. BY WEDNESDAY THE APPROACHING UPPER TROUGH SHOVES A COLD FRONT TOWARD S FLA THAT MOVES THROUGH THE AREA WEDNESDAY WITH SOME SHOWER ACTIVITY. THURSDAY AND FRIDAY WILL BE DRY BUT COOLER. LOWS THURSDAY WILL RANGE FROM NEAR 50 W OF LAKE OKEECHOBEE TO THE LOWER 60S SE WITH SLIGHTLY WARMER TEMPERATURES FRIDAY MORNING. HIGHS WILL BE IN THE 70S THURSDAY AND FRIDAY. MARINE... NNE TO NE WINDS AT 10 TO 15 KTS THROUGH MONDAY THEN SHIFTING MORE NORTHERLY AND SLIGHTLY DECREASING TUESDAY BEFORE INCREASING FROM THE NW WEDNESDAY BEHIND THE FRONT WITH MARINE CONDITIONS DETERIORATING. SOME RISK OF RIP CURRENTS POSSIBLE E COAST TODAY...SUNDAY AND MONDAY. WATERSPOUTS POSSIBLE ATLC WATERS TODAY AS OFFSHORE FLOW CONVERGING WITH THE EASTERLY ATLC FLOW OFFSHORE. FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE CURRENTLY ANTICIPATED. LOW PRESSURE TO THE SOUTH, WILL SLOWLY MOVE TO THE NORTH, WELL EAST OF THE BAHAMAS. THIS WILL ALLOW SLIGHTLY DRIER AIR TO MOVE IN NEXT WEEK, WITH SLIGHTLY COOLER TEMPERATURES AS WELL. WINDS, OVER THE NEXT FEW DAYS, WILL CONTINUE TO BE OUT OF THE NORTH NORTHEAST BETWEEN 5 AND 10 KTS. THEY WILL BECOME MORE NORTH TO NORTHWESTERLY BY MONDAY, STILL BETWEEN 5 AND 10KTS. AS FOR MINIMUM RH, EXPECT RH`S IN THE MID 50 PERCENT RANGE FOR THE WEEKEND, DROPPING INTO THE MID 40 TO LOW 50 PERCENT RANGE BEGINNING NEXT WEEK. RECOVERIES SHOULD CONTINUE TO BE GOOD EVERY NIGHT, REACHING INTO THE 90 PERCENT RANGE. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 66 80 63 79 / 30 20 10 - FORT LAUDERDALE 68 80 65 79 / 30 20 10 10 MIAMI 66 81 65 79 / 20 20 10 - NAPLES 62 80 61 75 / 10 10 10 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
644 PM EST SAT NOV 17 2012 .AVIATION... AS A STALLED FRONTAL BOUNDARY LINGERS JUST OFFSHORE THE ATLANTIC COAST...ISOLATED SHOWERS WILL REMAIN ACROSS THE AREA THROUGH THE NIGHT AND IS DEPICTED BY THE LATEST HRRR GUIDANCE. SHOWERS COULD BRIEFLY AFFECT ONE OR MORE EAST COAST SITES THROUGH THE EVENING WITH MVFR CONDITIONS BUT WOULD BE VERY BRIEF AND DECIDED NOT TO PREVAIL ANY SHRA MENTION. MID LEVEL DRYING EXPECTED TO PUSH INTO THE SOUTH FLORIDA PENINSULA FROM THE NORTH THROUGH THE LATTER HALF OF THE PERIOD. && .PREV DISCUSSION... /ISSUED 246 PM EST SAT NOV 17 2012/ DISCUSSION... SHORT TERM...THE BASIC SYNOPTIC SETUP OVER THE AREA IS A NORTHWESTERLY FLOW OVER THE CWA AS HIGH PRESSURE TO THE NORTH SLOWLY PUSHES A LOW PRESSURE SYSTEM WELL TO THE SOUTHEAST EASTWARD. THERE IS A STALLED BOUNDARY THAT CONTINUES TO LAY ACROSS THE OFFSHORE WATERS IN THE ATLANTIC. THE HIGH, CENTERED OVER NEW ENGLAND, IS VERY SLOWLY CAUSING THE BOUNDARY TO DRIFT TO THE EAST AND HAS PUSHED MOST OF THE SHOWERS AWAY FROM THE CWA. THIS BOUNDARY WILL NOT GO FAR, HOWEVER, AS THERE IS NO REAL PUSH NORMAL TO THE BOUNDARY. RATHER, THE FLOW IS ALMOST PARALLEL TO THE BOUNDARY. SO, WITH STILL PLENTY OF MOISTURE REMAINING OVER THE MAINLAND, DAYTIME HEATING WILL CAUSE SOME ISOLATED SHOWERS TO DEVELOP. MODELS ARE INDICATING MOST OF ANY CONVECTION WILL BE LOCATED MAINLY OFF SHORE. THIS PATTERN WILL BE IN PLACE FOR THE REMAINDER OF THE WEEKEND. OVER THE NEXT COUPLE OF DAYS, THE LOW WILL SLOWLY MOVE TO THE NORTH AS THE HIGH PRESSURE SLIDES WELL TO THE NORTHEAST. THE LOW WILL THEN DEEPEN AND INTERACT WITH THE STALLED BOUNDARY, TURNING IT INTO A COLD FRONT. THIS COULD ALLOW FOR SOME SHOWERS OVER THE ATLANTIC TO DEVELOP, BUT STILL LOOK ISOLATED AT BEST THROUGH 12Z TUESDAY. ALSO, WITH THE LOW DEVELOPING NEXT WEEK, SOMEWHAT COOLER, DRIER AIR WILL TRY TO MAKE ITS WAY DOWN THE FLORIDA PENINSULA. WHILE THE TEMPERATURES WILL ONLY COOL A COUPLE OF DEGREES, THE DEW POINTS SHOULD DROP AROUND 5 DEGREES, ALLOWING THE AIR TO FEEL SOMEWHAT DRIER FOR THE BEGINNING OF THE WEEK. LONG TERM...TUESDAY THROUGH FRIDAY...DRY AND STABLE AIR OVER S FLA TUESDAY PRECLUDES PRECIPITATION EXCEPT FOR THE E COAST. BY WEDNESDAY THE APPROACHING UPPER TROUGH SHOVES A COLD FRONT TOWARD S FLA THAT MOVES THROUGH THE AREA WEDNESDAY WITH SOME SHOWER ACTIVITY. THURSDAY AND FRIDAY WILL BE DRY BUT COOLER. LOWS THURSDAY WILL RANGE FROM NEAR 50 W OF LAKE OKEECHOBEE TO THE LOWER 60S SE WITH SLIGHTLY WARMER TEMPERATURES FRIDAY MORNING. HIGHS WILL BE IN THE 70S THURSDAY AND FRIDAY. MARINE... NNE TO NE WINDS AT 10 TO 15 KTS THROUGH MONDAY THEN SHIFTING MORE NORTHERLY AND SLIGHTLY DECREASING TUESDAY BEFORE INCREASING FROM THE NW WEDNESDAY BEHIND THE FRONT WITH MARINE CONDITIONS DETERIORATING. SOME RISK OF RIP CURRENTS POSSIBLE E COAST TODAY...SUNDAY AND MONDAY. WATERSPOUTS POSSIBLE ATLC WATERS TODAY AS OFFSHORE FLOW CONVERGING WITH THE EASTERLY ATLC FLOW OFFSHORE. FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE CURRENTLY ANTICIPATED. LOW PRESSURE TO THE SOUTH, WILL SLOWLY MOVE TO THE NORTH, WELL EAST OF THE BAHAMAS. THIS WILL ALLOW SLIGHTLY DRIER AIR TO MOVE IN NEXT WEEK, WITH SLIGHTLY COOLER TEMPERATURES AS WELL. WINDS, OVER THE NEXT FEW DAYS, WILL CONTINUE TO BE OUT OF THE NORTH NORTHEAST BETWEEN 5 AND 10 KTS. THEY WILL BECOME MORE NORTH TO NORTHWESTERLY BY MONDAY, STILL BETWEEN 5 AND 10KTS. AS FOR MINIMUM RH, EXPECT RH`S IN THE MID 50 PERCENT RANGE FOR THE WEEKEND, DROPPING INTO THE MID 40 TO LOW 50 PERCENT RANGE BEGINNING NEXT WEEK. RECOVERIES SHOULD CONTINUE TO BE GOOD EVERY NIGHT, REACHING INTO THE 90 PERCENT RANGE. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 66 80 63 79 / 20 20 10 - FORT LAUDERDALE 68 80 65 79 / 20 20 10 10 MIAMI 66 81 65 79 / 20 20 10 - NAPLES 62 80 61 75 / 10 10 10 - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
627 PM EST SAT NOV 17 2012 .SYNOPSIS... HIGH PRESSURE WILL KEEP DRY CONDITIONS AND SLIGHTLY ABOVE NORMAL TEMPERATURES ACROSS THE REGION THROUGH THANKSGIVING. A WEAK FRONT WILL CROSS THE AREA LATER FRIDAY INTO SATURDAY PRODUCING ONLY A SMALL CHANCE OF A SHOWER. && .NEAR TERM /THROUGH SUNDAY/... 630 PM UPDATE...WITH CLEAR SKIES AND LIGHT WINDS...LOWERED MINIMUM TEMPERATURES FOR MOUNTAIN AREAS GARRETT AND NORTHERN WEST VIRGINIA. DOESN`T LOOK LIKE CIRRUS FROM COASTAL SYSTEM WILL EVEN MAKE IT TO SE COUNTIES AND HRRR CONCURS. REST OF DISCUSSION FOLLOWS... A RIDGE OF HIGH PRESSURE EXTENDS FROM QUEBEC SOUTHWEST INTO THE MISSISSIPPI RIVER VALLEY. EXCEPT FOR A PASSING HIGH CLOUD...CLEAR SKIES ARE EXPECTED THROUGH THE NEXT 24 HOURS. FORECAST IS GENERALLY PERSISTENCE...WITH OVERNIGHT LOWS DROPPING BELOW FREEZING WITH CLEAR SKIES AND LIGHT WINDS ALLOWING FOR GOOD RADIATIONAL COOLING...AND SUNDAY/S HIGHS CLIMBING A DEGREE OR TWO FROM TODAY/S READINGS. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... QUIET WEATHER PERSISTS. CLOUDS WILL BE THE MAIN FORECAST CHALLENGE OF THE SHORT TERM...ESPECIALLY MONDAY NIGHT INTO TUESDAY. LOW PRESSURE OFF THE SERN CONUS WILL HAVE NO EFFECT OVER OUR AREA OUTSIDE PASSING ALTOCU OR CIRRUS IN THE AFOREMENTIONED TIME FRAME. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... HIGHLIGHTS... - MEDIUM TO HIGH CONFIDENCE - NO BIG STORMS OVER THE LONG HOLIDAY WEEKEND - NEAR NORMAL TEMPERATURES - FOLLOWED ECMWF EXTENDED FORECAST REMAINS RATHER UNEVENTFUL WHICH IS GOOD GIVEN THE TIME OF YEAR AND THE LARGE NUMBER OF PEOPLE OUT TRAVELING FOR THE UPCOMING HOLIDAY WEEKEND. UPPER LEVEL IMPULSES CROSS WEDNESDAY...BUT WITH MOISTURE CONVERGENCE VECTORS ORIGINATING FROM THE LAKES AND SRN CANADA...DO NOT EXPECT MUCH QPF...IF ANY AT ALL. A TRANSITORY H5 ANTI-CYCLONE ALLOWS A SUNNY AND MILD TURKEY DAY. THE NEXT SYNOPTIC FEATURE WILL BE A WEAK BAROCLINIC ZONE THE SECOND HALF OF FRIDAY. AGAIN...NOT MUCH IN THE WAY OF MOISTURE WITH THIS SYSTEM SO EXPECT MINIMAL QPF AT BEST. NW FLOW RESULTING FROM FAIRLY SIGNIFICANT HEIGHT FALLS OVER NEW ENGLAND ALLOW FOR LAKE EFFECT RW/SW TO DEVELOP SAT N OF I-80. H8 TEMPS AT THIS TIME ARE PROGGED IN THE -8 TO -10C RANGE...BUT DUE TO LESS THAN OPTIMAL INVERSION HEIGHTS...LITTLE ACCUMULATION IS PROJECTED SATURDAY. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... HIGH PRESSURE WILL ALLOW CLEAR SKIES AND LIGHT WINDS THROUGH THE TAF PERIOD. .OUTLOOK.../SUNDAY THROUGH THURSDAY/... THE NEXT CHANCE FOR RESTRICTIONS IS EXPECTED BY TUESDAY WITH A CROSSING DISTURBANCE...ALTHOUGH LIKELIHOOD OF RESTRICTIONS APPEARS LOW AT THIS TIME. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
651 AM EST FRI NOV 16 2012 .SYNOPSIS... ISSUED AT 310 AM EST FRI NOV 16 2012 QUIET AND SEASONABLE WEATHER IS EXPECTED THROUGH THE COMING WEEKEND AND LIKELY THROUGH THE THANKSGIVING DAY HOLIDAY. A GOOD DEAL OF SUNSHINE WITH TEMPERATURES AROUND 50 OR INTO THE 50S CAN BE EXPECTED THROUGH MONDAY. THERE IS A LOW CHANCE OF SOME RAIN DURING THE MID PORTION OF THE WEEK NEXT WEEK WITH A COUPLE OF WEAK SYSTEMS. TEMPERATURES WILL REMAIN MILD THROUGH THANKSGIVING. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 310 AM EST FRI NOV 16 2012 FORECAST CHALLENGES ARE RATHER MINIMAL THROUGH THE SHORT TERM WITH THE QUIET PATTERN IN PLACE. THE BIGGEST CONCERNS ARE PROBABLY FOG POTENTIAL AND CLOUD TRENDS THROUGH THE PERIOD. MOST SITES HAVE SOME REDUCTION IN VISIBILITY DUE TO LIGHT FOG THIS MORNING. MOST SITES ARE REMAINING ABOVE 3 MILES. A COUPLE OF SITES HAVE DROPPED DOWN INTO TRUE FOG BELOW A MILE. SO FAR...THIS SEEMS ISOLATED ENOUGH THAT A MENTION IN THE ZONES WILL SUFFICE. SOME CLOUDS WILL BE POSSIBLE TODAY AS THE WEAK FRONT CURRENTLY ACROSS NW LOWER MICHIGAN HAS SOME CLOUDS ASSOCIATED WITH IT THIS MORNING. LIKELY AIDING THE CAUSE FOR THESE CLOUDS IS SOME OVER LAKE INSTABILITY WITH DELTA T/S AROUND 10-11C THIS MORNING AND A SW FLOW AHEAD OF THE FRONT. WINDS WILL BECOME NE BEHIND THE FRONT...AND THERE COULD BE SOME CONTRIBUTION OF MOISTURE FROM LAKE HURON. THE ADDITIONAL MOISTURE AND LIGHT WINDS COULD ALLOW FOR SOME FOG ONCE AGAIN TONIGHT. THIS FRONT WILL SLOW DOWN ACROSS THE CWFA THIS AFTERNOON...BEFORE HEADING BACK NORTH OF THE AREA ON SAT. THIS OCCURS AS THE SFC RIDGE AXIS SHIFTS EAST OF THE AREA AND RETURN FLOW SETS UP. THE PATTERN WILL REMAIN LIKE THIS THROUGH SUNDAY AS THE OVERALL PATTERN GETS BOTTLE NECKED. WE MAY SEE A BATCH OF HIGH CLOUDS PASS ACROSS THE AREA WITH A WEAK UPPER WAVE...BUT THAT WOULD BE ABOUT IT. HIGHS WILL WARM INTO THE 50S FOR SAT AND SUN. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 310 AM EST FRI NOV 16 2012 FOR THE MOST PART EXPECT SLOWLY WARMING DAY TO DAY TEMPERATURES AND LITTLE IF ANY PRECIPITATION THROUGH THANKSGIVING. THERE IS A MOISTURE STARVED SHORTWAVE THAT CROSSES THE AREA IN THE TUESDAY TIME FRAME. THAT COULD RESULT IN A FEW SPRINKLES BUT THAT WOULD BE ABOUT IT. THERE IS FAIRLY HIGH CONFIDENCE IN THE FORECAST THROUGH THANKSGIVING SINCE THE MODEL AGREEMENT IN THAT TIME FRAME IS EXCELLENT FROM MODEL TO MODEL AND RUN TO RUN. HOWEVER MODEL CONTINUITY BREAKS DOWN SERIOUSLY AFTER THANKSGIVING BUT SINCE WE ONLY ARE FORECASTING OUT TO THANKSGIVING WE ARE GOOD! WE WILL ADDRESS THIS ISSUE IN LATER DISCUSSIONS. AS NOTED YESTERDAY THIS IS A VERY ANOMALOUS PATTERN FOR SOUTHWEST LOWER MICHIGAN AT THIS TIME YEAR. HAVING SO MANY DAYS IN NOVEMBER WITH NO MEASURABLE PRECIPITATION IS A LESS THAN 1 IN 10 SORT OF EVENT. ALSO AS NOTED YESTERDAY THE PROBLEM IS RELATED TO BLOCKING AT HIGH LATITUDES. NAMELY THE UPPER HIGH...THAT AT 00Z FRIDAY... WAS NEAR 178E AND 73N. IT IS CAUSING THE NORTHERN BRANCH OF THE POLAR JET TO STAY NORTH OF 65N AROUND THE HEMISPHERE. THUS LOCKING THE TRULY WINTER LIKE TEMPERATURES WELL NORTH OF HERE THROUGH THE END OF NEXT WEEK. THE PRIMARY POLAR JET IS STAYING NEAR THE CANADIAN BOARDER THROUGH THANKSGIVING. MEANWHILE THE SUB-TROPICAL JET IS DOWN NEAR THE GULF COAST AND WILL LIKELY STAY THERE UNTIL THANKSGIVING. SO... UNTIL THAT BLOCKING UPPER HIGH MOVES OUT OF THE WAY THIS OVERALL MILD AND DRY WEATHER PATTERN WILL CONTINUE HERE OVER SOUTHWEST LOWER MICHIGAN. ENJOY THIS MILD WEATHER WHILE YOU CAN.... && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 650 AM EST FRI NOV 16 2012 LARGELY MVFR VSBY PREVAILED AT 11Z THIS MORNING. MKG AND AZO ARE MARGINALLY IFR (2 MILES VSBY). THERE IS ALSO A BAND OF MVFR/IFR CIGS FROM STRATUS DROPPING SOUTH INTO THE ROUTE 10 AREA HEADING SOUTH WITH TIME TO0. DUE TO LIGHT WINDS BEING FORECAST (WINDS UNDER 15 KNOTS THROUGH 5000 FT AGL THROUGH SAT NIGHT) AND THE FEEBLE LATE NOVEMBER SUNSHINE NOT HELPING OUR MIXING PROCESS MUCH I WOULD EXPECT T0 SEE HAZE CONTINUE INTO LATE MORNING AFTER THE LIGHT FOG BURNS OFF AFTER SUNRISE. WE MAY HAVE MORE FOG ISSUES TONIGHT SINCE ONCE AGAIN WINDS REMAIN LIGHT SO THERE IS NOTHING TO MIX OUT THE AIR OVER US. WHILE IT IS TRUE A FRONT TRIES TO COME TROUGH TODAY IT IS "BRIDGED" WHICH MEANS IT DISSIPATES SO NOT MUCH HELP THERE. THE OTHER ISSUE IS THE STRATUS DECK MOVING SOUTH BEHIND THE FRONT. THE NAM AND RAP MODELS SEEM TO WANT TO MIX THIS OUT BY EARLY AFTERNOON. SO I CONTINUED THE SAME IDEA THE PREVIOUS SHIFT HAD. THAT IS TO BRING MVFR CIGS TO MKG BY LATE MORNING AND TEMPO GROUP IN THE GRR TAFS INTO MID AFTERNOON AFTERNOON. && .MARINE... ISSUED AT 310 AM EST FRI NOV 16 2012 THE STRONGEST WINDS THROUGH EARLY NEXT WEEK WILL BE UP NORTH OF WHITEHALL THIS MORNING. A DECENT N-NE GRADIENT WILL HELP WINDS UP TO 20 KNOTS TODAY UP NORTH. BEYOND THAT...WINDS SHOULD GENERALLY REMAIN AT OR BELOW 15 KNOTS THROUGH MONDAY. && .HYDROLOGY... ISSUED AT 310 AM EST FRI NOV 16 2012 NO HYDROLOGY ISSUES EXPECTED THROUGH THE PERIOD. NO RAIN EXPECTED THROUGH MONDAY...AND ONLY A CHANCE OF LIGHT RAIN NEXT WEEK WILL ALLOW THE AVERAGE TO BELOW AVERAGE RIVER LEVELS TO CONTINUE TO DROP. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...WDM AVIATION...WDM HYDROLOGY...NJJ MARINE...NJJ
AREA FORECAST DISCUSSION
NWS ELKO NV
253 PM PST FRI NOV 16 2012 .SYNOPSIS...A MOIST PACIFIC ONSHORE FLOW WILL COMBINE WITH TWO WEAK AREAS OF LOW PRESSURE TO BRING UNSETTLED WEATHER TO THE GREAT BASIN THIS WEEKEND. VALLEY RAIN AND MOUNTAIN SNOW SHOWERS WILL BE THE NORM...WITH THE HEAVIEST PRECIPITATION EXPECTED ACROSS HUMBOLDT AND ELKO COUNTIES. PARTIAL CLEARING AND WARM WEATHER IS EXPECTED FOR THE BEGINNING OF THANKSGIVING WEEK. && .SHORT TERM...FRIDAY NIGHT THROUGH MONDAY. TONIGHT...THE RAP AND NAM12 ARE PROGGING A BAND OF PRECIPITATION TO DEVELOP ACROSS CENTRAL NEVADA AND SLOWLY MOVE NORTH THIS EVENING. CURRENT RADAR IS BEGINNING TO SHOW AN AREA OF RAIN SHOWERS DEVELOPING FROM EUREKA TO FALLON. HAVE INCREASED POPS AND QPF FOR THIS POSSIBLE SOLUTION ACROSS CENTRAL NEVADA THIS EVENING. SATURDAY WILL BE A CLOUDY DAY AS A WEAKENING 500MB TROUGH OFF THE CALIFORNIA COAST MOVES INTO THE GREAT BASIN. FEATURE IS DYNAMICALLY WEAK...BUT HAS PWAT VALUES PUSHING OVER .50" TO WORK WITH...THUS FEELING HUMBOLDT COUNTY COULD PICK UP .10-.30" OF RAIN TOMORROW WITH ONLY THE HIGHEST TERRAIN EXPECTED TO GET SNOWFALL. LIGHTER AMOUNTS OF PRECIPITATION WILL FALL ACROSS THE REMAINING PART OF THE CWA. SATURDAY NIGHT INTO SUNDAY A STRONGER 500MB SHORTWAVE WILL PUSH IN FROM NORTHERN CALIFORNIA AND TRACK ACROSS NORTHERN NEVADA DURING THE DAY ON SUNDAY. AMPLE ANTECEDENT MOISTURE AHEAD OF THIS WAVE WILL LEAD TO THE BEST CHANCE FOR WIDESPREAD PRECIPITATION IN QUITE SOME TIME. SNOW LEVELS WILL START OUT HIGH ABOVE 7500K ON SATURDAY NIGHT...BEFORE DROPPING FROM WEST TO EAST DOWN TO 6000K ON SUNDAY. THERE WILL BE A BURST OF SNOW ACROSS THE HIGHER PASSES OF I-80...MOUNTAIN CITY HIGHWAY...AND U.S. 93...BUT FEEL AIR TEMPS WILL REMAIN AROUND OR JUST ABOVE FREEZING. THIS WILL LIMIT THE IMPACTS AND NOT THINKING ANY WWA HEADLINES WILL BE NEEDED FOR MAJOR TRAVEL CORRIDORS...BUT ZONE 034 COULD NEED AN ADVISORY WITH 4-6" OF SNOW POSSIBLE FOR THE EAST HUMBOLDT`S & RUBY MOUNTAINS. 500MB SHORTWAVE QUICKLY PUSHES OUT OF THE AREA SUNDAY NIGHT...WITH PARTIAL CLEARING EXPECTED ON MONDAY...AS HIGHS WARM BACK UP INTO THE 50S. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE PERIOD BEGINS WITH A LARGE UPPER TROUGH OFF THE PACIFIC NORTHWEST COAST WITH RIDGING OVER THE GREAT BASIN. SOME MOISTURE COMING OUT OF THE UPPER TROUGH WILL RIDE UP OVER THE RIDGE AND COULD BRING A FEW SHOWERS TO FAR NORTHERN NEVADA THROUGH WEDNESDAY. AS THE TROUGH COMES ONSHORE LATE WEDNESDAY AND THURSDAY THE ECMWF KEEPS MOST OF THE ENERGY TO OUR NORTH WHILE THE GFS DIGS IT FURTHER SOUTH. IN THE FORECAST GRIDS WENT WITH A BLEND OF THE ECMWF/GFS WITH 15-30 POPS FROM ABOUT I-80 NORTH. DAYTIME TEMPERATURES WILL REMAIN MILD WITH HIGHS IN THE 50S. && .AVIATION...MOIST SOUTHWEST FLOW ALOFT OVER THE AREA WILL BRING A FEW SHOWERS. CIGS/VSBYS EXPECTED TO REMAIN VFR. && .LKN WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 95/91/91
AREA FORECAST DISCUSSION
NWS RALEIGH NC
930 PM EST SAT NOV 17 2012 .SYNOPSIS... STRONG HIGH PRESSURE OVER THE NORTHEAST STATES WILL EXTEND SOUTHWARD INTO NORTH CAROLINA THROUGH MONDAY... WHILE BRISK NORTHEAST WINDS BRING A STRONG FLOW OF ATLANTIC MOISTURE INTO THE REGION. COOL AND CLOUDY CONDITIONS WITH A CHANCE OF RAIN WILL PERSIST INTO TUESDAY... AS LOW PRESSURE FORMS OFF THE NORTH CAROLINA COAST. && .NEAR TERM /THROUGH SUNDAY NIGHT/... AS OF 930 PM SATURDAY... REST OF TONIGHT: COMPLEX PATTERN ACROSS THE SOUTHEAST AND MIDATLANTIC THIS EVENING... AND THE MAIN FORECAST CONCERN REMAINS THE CHANCE FOR RAIN OVERNIGHT. SURFACE HIGH PRESSURE REMAINS QUITE STRONG (OVER 1038 MB) CENTERED OVER THE ST LAWRENCE VALLEY AND EXTENDING SOUTHWARD THROUGH NC... WHILE A STRENGTHENING LOW LEVEL FRONTAL ZONE AND DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST IS EXPECTED TO GENERATE A TIGHTENING MSLP GRADIENT OVERNIGHT... ESPECIALLY OVER THE SRN AND ERN CWA. CONVECTION WAS WIDESPREAD JUST OFF THE CAROLINA COAST THIS AFTERNOON... AND WHILE THE INTENSITY OF THIS RAIN HAS DECREASED... IT REMAINS IN PLACE JUST OFF THE SC AND SRN NC COAST. THE 12Z 4-KM WRF-ARW AND WRF-NMM DID A SUBPAR JOB IN DEPICTING THIS RAIN... ALTHOUGH THE 18Z LOCAL WRF-ARW DID BETTER AND IS SIMILAR TO THE LATEST HRRR OUTPUT... WHICH SHOWS THE BULK OF THE RAIN SHIELD HOLDING OVER AND JUST OFF THE SC COAST WITH JUST PATCHY RAIN SPREADING INTO OUR FAR SOUTHEAST COUNTIES OVERNIGHT. THIS ALSO APPEARS IN LINE WITH THE LATEST SREF PROBABILITIES OF MEASURABLE RAIN... WHICH KEEPS CHANCES UNDER 30 PERCENT IN THE SOUTHEAST TONIGHT. BASED ON THIS AND MODEL AGREEMENT ON ACCELERATING LOW LEVEL MOISTURE TRANSPORT TONIGHT AND THE PACE AT WHICH THE LOWER STRATUS AND SMALLER DEW POINT DEPRESSION AIR IS SPREADING WESTWARD INTO SOUTHEAST NC... WILL HOLD ONTO A SLIGHT CHANCE OF RAIN TONIGHT IN THIS AREA. FORECAST SOUNDINGS DEPICT A FAIRLY DEEP (3000-4000 FT THICK) SURFACE-BASED STABLE LAYER... BUT CLOSE EXAMINATION REVEALS A VERY SHALLOW (FEW HUNDRED FEET) SLIGHTLY MIXED LAYER RIGHT AT THE SURFACE... REASONABLE CONSIDERING HOW THE WINDS THROUGHOUT THE LOWEST FEW THOUSAND FEET WILL BE STRENGTHENING AT ONCE. WILL KEEP WINDS UP OVERNIGHT WITH PERIODIC GUSTS. THE LOW LEVEL STIRRING WILL HOLD TEMPS UP... AND EXPECT LOWS OF 38-48. -GIH SUNDAY AND SUNDAY NIGHT...THE MID LEVEL ANTI-CYCLONE OFF THE SOUTHERN NEW ENGLAND COAST AND THE NE FL/SRN GA COAST WILL MAINTAIN A DEEP ELY FLOW INTO CENTRAL NC WITH SPEED CONFLUENCE NOTED OVER THE REGION DURING THE AFTERNOON-EARLY EVENING HOURS. THE LIFT SUPPLIED BY THIS CONFLUENCE WILL GENERATE AREAS OF LIGHT RAIN...MAINLY ALONG THE I-95 CORRIDOR. FARTHER WEST...LIFT WEAKER TO NON-EXISTENT. THIS WILL LEAD TO PRECIP CHANCES RANGING FROM LIKELY IN THE EAST TO LOW END CHANCE-SLIGHT CHANCE IN THE FAR WEST LATE SUNDAY INTO SUNDAY NIGHT. EXPECT A NARROW DIURNAL TEMP RANGE SUNDAY SUNDAY NIGHT DUE TO CLOUDS AND PRECIP. MAX TEMPS LOW-MID 50S SUNDAY.MIN TEMPS SUNDAY NIGHT AROUND 40 NW TO UPPER 40S/NEAR 50 E-SE. -WSS && .SHORT TERM /MONDAY AND MONDAY NIGHT/... AS OF 310 PM SATURDAY... MONDAY AND MONDAY NIGHT...WHILE MID LEVEL ANTI-CYCLONE WILL REMAIN NEARLY STATIONARY OFF THE NORTHERN MID ATLANTIC COAST...THE AREA OF LOW PRESSURE OFF THE NE FL COAST WILL LIFT TO THE ENE. THIS MOVEMENT OF THE LOW WILL CAUSE THE MID LEVEL FLOW OVER CENTRAL NC TO WEAKEN AND BECOME MORE NELY. THUS...EXPECT RAIN CHANCES TO DWINDLE MONDAY WITH A SLIGHT CHANCE POP CONFINED TO THE EASTERN HALF BY AFTERNOON....AND LITTLE IF ANY RAIN EXPECTED MONDAY NIGHT. MODEL GUIDANCE DIFFERS AS TO THE AMOUNT OF DECREASING CLOUDINESS TO OCCUR WHICH LEADS TO DISCREPANCIES IN THE TEMP GUIDANCE MONDAY. LATEST NAM MORE EMPHATIC WITH ITS CLEARING TREND WHICH TRANSLATES TO WARMER AFTERNOON TEMPS. THE 12Z ECMWF WEAKEN OFFERS A SCENARIO SOMEWHAT BUT NOT AS EMPHATIC WITH THE AMOUNT OF DRYING. GFS MAINTAINS A SATURATED AIR MASS THROUGH THE PERIOD. PLACED A BIT MORE EMPHASIS TOT EH GFS AS POTENTIAL EXIST FOR MOISTURE TO BE TRAPPED BELOW MID LEVEL SUBSIDENCE INVERSION. THUS WILL FAVOR HIGH TEMPS MONDAY TOWARD THE COOLER GFS MOS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 310 PM SATURDAY... BRIEF S/W RIDING ALOFT AT THE START OF THE MEDIUM RANGE PERIOD IS EXPECTED TO QUICKLY SHIFT TO THE EAST OF THE AREA ON TUESDAY AS A PAIR OF MID/UPPER LEVEL DISTURBANCES USHER IN A RETURN TO POSSIBLE UNSETTLE WEATHER. HOWEVER... AT THE SURFACE/LOW LEVELS OF THE ATMOSPHERE EXPECT A GENERALLY NORTHERLY FLOW WILL CONTINUE... WITH THE AFOREMENTIONED SURFACE LOW PRESSURE EXPECTED TO REMAIN OFFSHORE OR SLOWLY LIFT NORTH OR NORTHEASTWARD. MODELS ARE CONTINUING TO STRUGGLE THOUGH WRT POSSIBLE LIGHT RAIN FOR TUESDAY INTO TUESDAY NIGHT. THE DIFFERENCES APPEAR TO BE TIED TO THE STRENGTH IN THE MID/UPPER LEVEL RIDGING AND APPROACHING NEXT SET OF IMPULSES ALOFT. FOR NOW WILL TREND THE FORECAST TO THE DRIER SIDE OF GUIDANCE (CLOSER TO THE ECMWF AND NAM). FOR NOW WILL LOWER POPS TO SLIGHT CHANCE AREAWIDE. HOWEVER... STILL EXPECT SKIES WILL BE AT LEAST MOSTLY CLOUDY WHICH WILL STILL HELP SUPPRESS HIGH TEMPS DESPITE LOW LEVEL THICKNESS VALUES AROUND NORMAL. WILL GO WITH HIGH TEMPS IN THE UPPER 50S TO AROUND 60... A BIT BELOW NORMAL. HOWEVER... IF THE RAIN DOES MATERIALIZE EXPECTED TEMPS WOULD BE A GOOD 5 TO 10 DEGREES COOLER AT LEAST THAN CURRENT FORECAST. LOW TUESDAY NIGHT/WEDNESDAY MORNING ARE EXPECTED TO BE IN THE LOWER TO MID 40S... WITH SKIES BEGINNING TO CLEAR AT BIT (MORE SO WEST) AS THE FIRST DISTURBANCE BEGINS TO PUSH TO THE EAST OF THE AREA. MID/UPPER LEVEL TROUGH AXIS IS EXPECTED TO AMPLIFY ACROSS THE AREA AGAIN ON WEDNESDAY AS A SECOND S/W TROUGH ROTATES THROUGH THE AREA ON WEDNESDAY/WEDNESDAY NIGHT. HOWEVER... DESPITE THE DEEPENING TROUGH... BEST LIFT AND MOISTURE SHOULD REMAIN TO THE SOUTH OF THE AREA. THUS... WITH AFTERNOON LOW LEVEL THICKNESS VALUES AROUND NORMAL AND SKIES BECOMING PARTLY SUNNY LATE IN THE DAY EXPECT HIGH TEMPS TO BE IN THE UPPER 50S TO LOWER 60S. LOWS WITH CLEARING SKIES ON THURSDAY MORNING ARE EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S. THURSDAY THROUGH SATURDAY: RIDGING ALOFT IS EXPECTED TO BUILD ACROSS THE AREA DURING THIS TIMEFRAME... WHILE A NORTHERN STREAM SYSTEM IS EXPECTED TO MOVE ACROSS THE NORTHERN PORTION OF THE COUNTRY. AT THE SURFACE EXPECT HIGH PRESSURE WILL REMAIN ACROSS THE AREA THROUGH AT LEAST FRIDAY MORNING/AFTERNOON... BEFORE A TRAILING DRY COLD FRONT ASSOCIATED WITH THE NORTHERN STREAM SYSTEM IS EXPECTED TO MOVE THROUGH THE AREA LATE FRIDAY INTO FRIDAY NIGHT. HIGH PRESSURE IS EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT ON SATURDAY. EXPECT ABOVE NORMAL TEMPS THURSDAY/FRIDAY... WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS ON SATURDAY. EXPECT HIGH TEMPS IN THE 60S THURSDAY/FRIDAY TO UPPER 50S TO AROUND 60 NEXT SATURDAY. LOWS IN THE UPPER 30S TO LOWER 40S... WITH POSSIBLE MID 30S IN THE USUAL RURAL COOL/COLDER AREAS. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AS OF 700 PM SATURDAY... ONLY MEDIUM CONFIDENCE IN THE CURRENT AVIATION FORECAST AS LOW CLOUDS MOVE INTO THE AREA TONIGHT AND LINGER INTO EARLY NEXT WEEK. THE COMBINATION OF AN UPPER LEVEL WAVE AND A WEAK SURFACE LOW OFFSHORE WILL LEAD TO STRENGTHENING EAST-NORTHEASTERLY LOW LEVEL FLOW AS STRATUS SURGES INLAND FROM THE COAST TONIGHT. CEILINGS OVER THE NC COASTAL PLAIN ARE CURRENTLY AROUND 3K FT AND THESE CEILINGS WILL REACH KRWI AND KFAY BY 02Z...AND POSSIBLY KRDU BY 06Z... LOWERING TO IFR BY 12Z. THE LOW LEVEL AIRMASS IS MUCH DRIER TO THE WEST OF KRDU AND THERE IS LESS CONFIDENCE IN MVFR/IFR CEILINGS REACHING KGSO/KINT BY 12Z. PRECIP WILL ALSO BEGIN TO SPREAD INLAND SUNDAY MORNING...WITH KRDU/KRWI/KFAY EXPECTED TO SEE LIGHT RAIN DURING THE DAY. AGAIN...WITH DRIER AIR OVER WESTERN NC...KGSO AND KINT MAY BE ON THE EDGE OF THE LIGHT RAIN. WHILE A PERIOD OF IFR CEILINGS ARE POSSIBLE...CEILINGS SHOULD REMAIN ABOVE 1000KT AND EVEN RISE A LITTLE DURING THE DAY SUNDAY. THE OTHER CONCERN DURING THE TAF PERIOD WILL BE STRENGTHENING NORTHEASTERLY WINDS AND TURBULENCE/LOW LEVEL WIND SHEAR. MODELS ARE INDICATING THAT WINDS WILL INCREASE BETWEEN THE WEAK LOW OFFSHORE AND A STRONG HIGH PRESSURE OVER NEW ENGLAND....WITH WINDS AT 2000 FT AS STRONG AS 40KT FROM KFAY TO KRWI AND EASTWARD SUNDAY AFTERNOON. THE LOW LEVEL WINDS WILL BE MOSTLY UNIDIRECTIONAL AND WELL MIXED IN THE BOUNDARY LAYER...SO LOW LEVEL WIND SHEAR CRITERIA MAY NOT BE MET. HOWEVER...SUSTAINED 10-15KT WINDS WITH GUSTS TO 25KT SHOULD BE EXPECTED. OUTLOOK... LOW CLOUDS ARE EXPECTED TO LINGER THROUGH AT LEAST TUESDAY...WITH PREDOMINATELY MVFR CONDITIONS....THOUGH IFR CONDITIONS ARE POSSIBLE MONDAY MORNING. THERE IS SOME UNCERTAINTY AS TO HOW QUICKLY VFR CONDITIONS WILL RETURN...BUT A GENERAL IMPROVEMENT IS EXPECTED TUESDAY THROUGH THURSDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD/WSS SHORT TERM...WSS LONG TERM...BSD AVIATION...BLS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
153 PM CST FRI NOV 16 2012 .SHORT TERM...THROUGH MONDAY NIGHT 153 PM CST FRI NOV 16 2012 STRATUS ALONG WITH FOG POTENTIAL WILL BE AN IMMEDIATE CONCERN TONIGHT...MAINLY ALONG/NORTHEAST OF I-94. FOCUS THEN SHIFTS TO MILDER PATTERN...ALONG WITH RAIN CHANCES ENTERING THE PICTURE SUNDAY NIGHT THROUGH MONDAY EVENING. SURFACE MAP HAS A HIGH PRESSURE RIDGE AXIS EXTENDING FROM SOUTHERN ONTARIO INTO EASTERN MN/WESTERN IA. VISIBLE SATELLITE AND SURFACE OBSERVATIONS SHOWING NORTHEAST WIND FETCH ACROSS LAKE MICHIGAN HAS BROUGHT AREAS OF STRATUS/STRATOCUMULUS INTO PORTIONS OF EASTERN/CENTRAL WISCONSIN. OTHERWISE...CLEAR/SUNNY SKIES PREVAILED ACROSS THE REST OF THE AREA THANKS TO THE RIDGE OF HIGH PRESSURE WITH TEMPERATURES AT 2 PM RANGING FROM THE LOW 40S TO NEAR 50 DEGREES. 16.12Z MODELS IN FAIRLY GOOD AGREEMENT THROUGH THE SHORT TERM.. FOR TONIGHT...WILL BE WATCHING FOR AREAS OF STRATUS/FOG ACROSS CENTRAL WISCONSIN...MAINLY NORTHEAST OF I-94 AS RIDGE AXIS SLOWLY SHIFTS INTO THE GREAT LAKES REGION. NAM/RAP IN GOOD AGREEMENT WITH COOLING/SATURATION IN THE LOWEST 0.5KM AS LIGHT SOUTHEAST FLOW CONTINUES TO ADVECT MOISTURE OFF OF LAKE MICHIGAN. QUESTION WILL BE HOW EXPANSIVE LOW CLOUDS AND FOG WILL BE. BESIDES THE NAM/RAP SHOWING FAIRLY SATURATED CONDITIONS IN THE LOWEST 0.5KM...3 OUT OF 4 MESO-WRF MODELS DEPICTING CIG HEIGHT/VIS INDICATING A FAIRLY STRONG SIGNAL FOR LOW CLOUD/FOG POTENTIAL. HAVE INCREASED CLOUD COVER FOR AREAS MAINLY ALONG/NORTHEAST OF I-94 THIS EVENING AND INTO THE EARLY MORNING HOURS. ALSO ADDED AREAS OF FOG MENTION. NOT CONFIDENT HOW LOW VISIBILITIES WILL GET. THINKING THERE MAY BE ISOLATED POCKETS OF DENSER FOG WITH VISIBILITY BELOW A MILE...BUT THINKING 3-5SM SHOULD BE THE RULE. MODELS THEN SHOW THIS LOW-LEVEL MOISTURE/LOW CLOUD ADVECTING NORTHEAST OUT OF THE AREA AROUND DAWN WITH INCREASING PRESSURE GRADIENT/SOUTH WINDS ON THE BACKSIDE OF THE HIGH. FOCUS THEN SHIFTS TO MODERATING/MILDER TEMPERATURES PUSHING INTO THE AREA SATURDAY/SUNDAY WITH BREEZY SOUTHERLY FLOW. NAM/GFS SHOWING 925MB TEMPERATURES WARMING FROM 5-7C ON SATURDAY...INTO THE 6-9C RANGE ON SUNDAY. SOME ALTOCUMULUS WILL BE SEEN FROM TIME TO TIME SATURDAY THROUGH SUNDAY IN WARM AIR ADVECTION/ISENTROPIC LIFT...BUT NOT EXPECTED TO HINDER WARMING DURING THE DAY. GIVEN THIS AND WARMING 925MB TEMPERATURES...PLAN ON HIGHS SATURDAY IN THE LOWER TO MIDDLE 50S AND IN THE MID-UPPER 50S ON SUNDAY. ATTENTION THEN TURNS TO RAIN CHANCES SUNDAY NIGH THROUGH MONDAY NIGHT. MODELS SHOWING GOOD RUN-TO RUN CONSISTENCY WITH MID-LEVEL TROUGH/WEAK SURFACE COLD FRONT MOVING OUT OF THE PLAINS AND ACROSS THE AREA. FORCING IS NOT OVERLY STRONG WITH THE TROUGH/FRONT AND NOT A LOT OF MOISTURE TO WORK WITH. AS A RESULT...IT WILL COME DOWN TO HOW MUCH THE COLUMN GETS SATURATED GIVEN THE WEAKER FORCING. THE GFS...MORE THAN THE NAM...SHOWING FAIRLY LIGHT RAINFALL ACROSS THE AREA WITH AMOUNTS GENERALLY A FEW HUNDRETHS OF AN INCH AT MOST. GIVEN THIS SIGNAL AND LEVEL OF SATURATION IN QUESTION...WILL KEEP RAIN PROBABILITIES ON THE LOW SIDE AROUND 30 PERCENT...CENTERED ON MONDAY. .LONG TERM...TUESDAY THROUGH FRIDAY NIGHT 153 PM CST FRI NOV 16 2012 16.12Z GFS AND ECMWF CONTINUE THE MILD TREND FOR THE AREA THROUGH THE LONG TERM AS THE MAIN STORM TRACK STAYS UP IN CANADA. SOME DIFFERENCE ARISE ON WEAK/DRY COLD FRONTAL PASSAGE WEDNESDAY/THANKSGIVING DAY TIME FRAME. THE GFS IS A BIT FASTER WITH THIS PASSAGE TAKING PLACE WEDNESDAY NIGHT WHEREAS THE ECMWF SHOWS PASSAGE DURING THE DAY ON THANKSGIVING. EITHER WAY AS MENTIONED... THIS FRONT APPEARS O HAVE A DRY PASSAGE WITH TEMPERATURES CONTINUING TO TREND WELL ABOVE NORMAL. MODELS THEN HAVE DIFFERENCES RESOLVING A MID-LEVEL TROUGH MOVING OVER THE RIDGE ON FRIDAY. THE ECMWF SHOW A MUCH MORE PROGRESSIVE/WEAK TROUGH WORKING ACROSS THE AREA BY THURSDAY EVENING ALREADY WHEREAS THE GFS SHOW A MUCH MORE VIGOROUS MID-LEVEL TROUGH/SURFACE LOW MOVING OUT OF THE PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. MORE WEIGHT PUT INTO THE ECMWF AT THIS POINT WITH DRY FRIDAY. OTHERWISE AS STATED EARLIER...LOOK FOR TEMPERATURES TO REMAIN ABOVE NORMAL THROUGH AT LEAST THANKSGIVING WITH HIGHS IN THE UPPER 40S TO MIDDLE 50S. && .AVIATION...THROUGH 18Z SATURDAY 1125 AM CST FRI NOV 16 2012 SURFACE HIGH PRESSURE WILL DRIFT EASTWARD THIS AFTERNOON AND TONIGHT RESULTING IN A TIGHTENING PRESSURE GRADIENT AT THE TAF SITES. LOW LEVEL MOISTURE OFF LAKE MICHIGAN AS DEPICTED IN THE 0-1KM RELATIVE HUMIDITY PROGS FROM THE 16.12Z RAP REMAINS EAST OF KLSE. THUS HAVE KEPT THE ENTIRE TAF PERIOD WITH CLEAR SKIES. WITH THE GRADIENT INCREASING...SOUTHEAST WINDS 5 TO 10 KNOTS EXPECTED TONIGHT AND THEN INCREASING AFTER 15Z SATURDAY...ESPECIALLY AT KRST WHERE SOME GUSTS TO 22 KNOTS ARE LIKELY BEFORE 18Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 153 PM CST FRI NOV 16 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1125 AM CST FRI NOV 16 2012 .SHORT TERM...THROUGH SUNDAY NIGHT 200 AM CST FRI NOV 16 2012 MAIN FORECAST FOCUS IS ON CLOUD COVER AND TEMPERATURES WITH A QUIET WEATHER PATTERN IN PLACE. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING FROM NEW MEXICO INTO THE DAKOTAS...A SHORTWAVE OVER NEVADA...AND SHORTWAVE TROUGHS OVER FAR SOUTHERN ALBERTA INTO SASKATCHEWAN...AS WELL AS OVER INDIANA. THE FORECAST AREA LIES IN SUBSIDENCE AND DRYING BEHIND THE LATTER SHORTWAVE TROUGH. 00Z MPX AND ABR SOUNDINGS WERE QUITE DRY WITH PRECIPITABLE WATER VALUES AROUND 0.17 INCHES AND DEWPOINT DEPRESSIONS OF 10C OR MORE THROUGHOUT. THE SUBSIDENCE WAS NOTED AT THE SURFACE BY HIGH PRESSURE WHICH STRETCHES FROM KANSAS INTO NORTHERN ONTARIO. THE CLEAR SKIES...LIGHT WINDS AND DRY AIR ASSOCIATED THEN WITH THIS RIDGE HAS ALLOWED TEMPERATURES TO DROP INTO THE 20S AT MOST LOCATIONS. TO THE WEST...LITTLE IS GOING ON WITH THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE TROUGH EXCEPT FOR SOME CIRRUS. TODAY AND TONIGHT...THE UPPER RIDGING SEEN OVER THE DAKOTAS IS FORECAST TO MOVE OVER THE AREA TODAY...THEN TO LAKE ERIE TONIGHT... IN RESPONSE TO THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE PUSHING EAST. ALTHOUGH THIS SETUP PLACES THE FORECAST AREA UNDER SOUTHWEST FLOW ALOFT...TYPICALLY GOOD FOR PRECIPITATION...THE EXTENSIVE AMOUNT OF DRY AIR PRESENT WILL PREVENT ANY PRECIPITATION FROM OCCURRING. IN FACT...WE MAY NOT SEE MUCH CLOUD COVER BESIDES SOME SCATTERED HIGH CLOUDS MOVING ACROSS THIS AFTERNOON/EVENING... ASSOCIATED WITH THE ALBERTA/SASKATCHEWAN SHORTWAVE PASSING TO OUR NORTH. A WARM ADVECTION PATTERN WILL ENSUE THIS AFTERNOON AS THE CURRENT HIGH PRESSURE RIDGE MOVES EAST INTO THE GREAT LAKES REGION. 925MB TEMPS ARE PROGGED TO RANGE FROM -2C NORTH TO +2C SOUTH AT 18Z TODAY...ABOUT 3 TO 5C COOLER THAN YESTERDAY. THUS... HIGHS WILL BE A BIT COOLER DESPITE FULL SUNSHINE. THE WARM ADVECTION SHOULD INCREASE TONIGHT AS LOW PRESSURE BEGINS TO FORM NEAR RAPID CITY...ASSOCIATED WITH THE NEVADA SHORTWAVE LIFTING INTO WESTERN SOUTH DAKOTA. THE INCREASING SOUTHERLY FLOW WILL HELP KEEP TEMPERATURES UP...PARTICULARLY OVER THE HIGHER TERRAIN WEST OF THE MISSISSIPPI RIVER. NOTE THAT THE TYPICAL COLD SPOTS OF WISCONSIN COULD GET CHILLY...SINCE THE SOUTHERLY FLOW TAKES LONGER TO RAMP UP THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE WHICH HAS A GOOD HANDLE ON BOTH TEMPERATURE SITUATIONS. SATURDAY AND SATURDAY NIGHT...MODELS ARE IN GOOD AGREEMENT IN KEEPING THE AREA IN SOUTHWEST FLOW ALOFT...WITH THE CURRENT NEVADA SHORTWAVE FOLLOWING THE FLOW AND LIFTING INTO CENTRAL MINNESOTA BY 12Z SUNDAY. SURFACE PRESSURE GRADIENT IS PROGGED TO BE FAIRLY TIGHT THROUGHOUT THIS PERIOD...DUE TO THE DOWNSLOPING FLOW OFF THE ROCKIES KEEPING PRESSURES LOW ON THE LEE SIDE WHILE THE CURRENT HIGH PRESSURE AREA STRENGTHENS OVER THE EASTERN GREAT LAKES. THUS... BREEZY CONDITIONS ARE ON TAP. FORECAST 925MB WINDS ARE 25-30KT ON SATURDAY AND WITH WHAT LOOKS TO BE PLENTY OF SUN UNTIL SOME CIRRUS LATE IN THE DAY...SOME MIXING DOWN OF THOSE HIGHER WINDS CAN BE EXPECTED. GUSTS OF 20-25KT SEEMS LIKELY. REGARDING TEMPERATURES... 925MB READINGS ARE 4-6C AT 18Z...WHICH SHOULD PUT MOST LOCATIONS INTO THE 50S. FOR SATURDAY NIGHT...THERE ARE INDICATIONS OF MID AND HIGH CLOUDS INCREASING/THICKENING OVER THE FORECAST AREA AHEAD OF THE SHORTWAVE LIFTING INTO CENTRAL MINNESOTA. IN ADDITION... ISENTROPIC LIFT PLOTS ON THE 295-300K SURFACES SHOW WEAK LIFT FROM 650-780MB CENTERED MOSTLY WEST OF THE MISSISSIPPI RIVER AFTER 06Z. HOWEVER...PLENTIFUL DRY AIR EXISTS BELOW 800MB TO PREVENT PRECIPITATION...ESPECIALLY GIVEN ONLY WEAK LIFT EXPECTED. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE...STAYED ON THE WARM SIDE OF GUIDANCE FOR LOWS. SUNDAY AND SUNDAY NIGHT...THE SHORTWAVE IN CENTRAL MINNESOTA AT 12Z SUNDAY ALL MODELS HAVE LIFT TOWARDS THE THUNDER BAY ONTARIO AREA BY 00Z MONDAY...ALLOWING FOR A WEAK UPPER RIDGE TO BUILD INTO THE FORECAST AREA BEHIND IT IN THE GENERAL SOUTHWEST FLOW. THIS WEAK RIDGE MAY ALLOW FOR A LITTLE THINNING OF THE CLOUD COVER FROM SATURDAY NIGHT...RESULTING IN A PARTLY SUNNY DAY. 925MB TEMPS ARE PROGGED IN THE 4-7C RANGE...WHICH WOULD ALLOW LOCATIONS THAT HAVE MORE SUN TO APPROACH 60F. HAVE KEPT HIGH TEMPERATURES IN THE 50S FOR NOW DUE TO CLOUD COVER UNCERTAINTY. ANOTHER WEAK SHORTWAVE TROUGH IS PROGGED TO COME UP THROUGH THE SOUTHWEST FLOW AND REACH WESTERN PORTIONS OF IOWA AND MINNESOTA BY 12Z MONDAY. THIS TROUGH LOOKS TO HAVE A BETTER TAP INTO GULF OF MEXICO MOISTURE...THUS AT A MINIMUM AN EXTENSIVE STRATUS THROUGH MID AND HIGH CLOUD DECK IS LIKELY TO ACCOMPANY IT. HOWEVER...ISENTROPIC LIFT FORCING IS WEAK AT BEST... FOCUSED MAINLY AROUND 700MB ON THE 300K SURFACE AND BETWEEN 06-12Z MONDAY. AS SUCH...MODEL QPF FIELDS ARE QUITE LIGHT AND EVEN THE 16.00Z NAM KEEPS THE PRECIPITATION EVEN WEST OF THE FORECAST AREA. FOR NOW THERE REMAINS ENOUGH OF A SIGNAL TO MAINTAIN A 20 PERCENT CHANCE WEST OF THE MISSISSIPPI RIVER. WITH A SOUTHERLY BREEZE PERSISTING AND CLOUDS AROUND...ANOTHER MILD NIGHT FOR MID-NOVEMBER IS ON TAP...AND AGAIN FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...MONDAY THROUGH THANKSGIVING NIGHT 200 AM CST FRI NOV 16 2012 OVERALL...REALLY GOOD MODEL AGREEMENT EXISTS ON THE UPPER LEVEL AND SURFACE PATTERNS AMONGST 16.00Z GUIDANCE THROUGH ABOUT WEDNESDAY. THE PATTERN FEATURES THE PLAINS TROUGH SUNDAY NIGHT LIFTING UP INTO NORTHERN ONTARIO ON TUESDAY...FOLLOWED BY RIDGING BUILDING INTO THE FORECAST AREA FOR TUESDAY NIGHT INTO WEDNESDAY. 20-30 PERCENT CHANCES OF RAIN ARE MAINTAINED FOR MONDAY...ASSOCIATED WITH THE WEAK ISENTROPIC LIFT AND DPVA ASSOCIATED WITH THE PLAINS TROUGH. NOTE THAT ANY PRECIPITATION LOOKS MINIMAL AT THIS TIME...THUS THE LOW CHANCES. THERE MAY STILL BE SOME LINGERING PRECIPITATION IN THE FAR EASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT...THUS A 20 PERCENT CHANCE EXISTS THEN. DRY WEATHER FOLLOWS FOR TUESDAY INTO WEDNESDAY WITH THE UPPER RIDGE BUILDING IN AND SURFACE RIDGE IN PLACE. TEMPERATURES LOOK TO REMAIN ABOVE NORMAL...ESPECIALLY ON WEDNESDAY AS A SURGE OF DOWNSLOPED AIR OFF THE ROCKIES FLOWS INTO THE FORECAST AREA. THIS AIR IS CHARACTERIZED BY 850MB STANDARDIZED ANOMALIES OF 1.5 ABOVE NORMAL. THUS...HAVE LEANED TOWARDS THE WARMER ECMWF GUIDANCE FOR HIGHS...IN THE 55 TO 60 RANGE. THESE MAY NEED TO BE INCREASED IN FUTURE RUNS. FROM WEDNESDAY NIGHT THROUGH THANKSGIVING NIGHT...THERE IS A LITTLE MORE DISAGREEMENT WITH WHAT HAPPENS IN THE UPPER LEVELS. 15.12Z/16.00Z ECMWF ALLOWS A SHORTWAVE COMING OUT OF A NORTHEAST PACIFIC TROUGH AND TRACKS IT ALONG THE U.S./CANADIAN BORDER AND INTO LAKE SUPERIOR THANKSGIVING NIGHT. THIS SITUATION ALLOWS FOR A COLD FRONTAL PASSAGE ON THANKSGIVING...THOUGH THE TRUE COLDER AIR FILTERS IN DURING THE NIGHT TIME. ON THE OTHER HAND...THE 16.00Z GFS/GFS ENSEMBLES AND EXTRAPOLATION OF THE 16.00Z CANADIAN/UKMET PREFER TO HOLD UPPER RIDGING IN PLACE OVER THE FORECAST AREA. WITH THIS SCENARIO...THE WELL ABOVE NORMAL WARMTH SEEN ON WEDNESDAY WOULD PERSIST THROUGH THANKSGIVING NIGHT BEFORE A COLD FRONT PASSES ON FRIDAY. FOR NOW HAVE MAINTAINED A CONSENSUS SOLUTION GIVEN THE DIFFERENCES. EITHER SOLUTION HAS LITTLE MOISTURE TO WORK WITH SO A DRY FORECAST IS STILL ON TAP. && .AVIATION...THROUGH 18Z SATURDAY 1125 AM CST FRI NOV 16 2012 SURFACE HIGH PRESSURE WILL DRIFT EASTWARD THIS AFTERNOON AND TONIGHT RESULTING IN A TIGHTENING PRESSURE GRADIENT AT THE TAF SITES. LOW LEVEL MOISTURE OFF LAKE MICHIGAN AS DEPICTED IN THE 0-1KM RELATIVE HUMIDITY PROGS FROM THE 16.12Z RAP REMAINS EAST OF KLSE. THUS HAVE KEPT THE ENTIRE TAF PERIOD WITH CLEAR SKIES. WITH THE GRADIENT INCREASING...SOUTHEAST WINDS 5 TO 10 KNOTS EXPECTED TONIGHT AND THEN INCREASING AFTER 15Z SATURDAY...ESPECIALLY AT KRST WHERE SOME GUSTS TO 22 KNOTS ARE LIKELY BEFORE 18Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 200 AM CST FRI NOV 16 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
544 AM CST FRI NOV 16 2012 .SHORT TERM...THROUGH SUNDAY NIGHT 200 AM CST FRI NOV 16 2012 MAIN FORECAST FOCUS IS ON CLOUD COVER AND TEMPERATURES WITH A QUIET WEATHER PATTERN IN PLACE. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING FROM NEW MEXICO INTO THE DAKOTAS...A SHORTWAVE OVER NEVADA...AND SHORTWAVE TROUGHS OVER FAR SOUTHERN ALBERTA INTO SASKATCHEWAN...AS WELL AS OVER INDIANA. THE FORECAST AREA LIES IN SUBSIDENCE AND DRYING BEHIND THE LATTER SHORTWAVE TROUGH. 00Z MPX AND ABR SOUNDINGS WERE QUITE DRY WITH PRECIPITABLE WATER VALUES AROUND 0.17 INCHES AND DEWPOINT DEPRESSIONS OF 10C OR MORE THROUGHOUT. THE SUBSIDENCE WAS NOTED AT THE SURFACE BY HIGH PRESSURE WHICH STRETCHES FROM KANSAS INTO NORTHERN ONTARIO. THE CLEAR SKIES...LIGHT WINDS AND DRY AIR ASSOCIATED THEN WITH THIS RIDGE HAS ALLOWED TEMPERATURES TO DROP INTO THE 20S AT MOST LOCATIONS. TO THE WEST...LITTLE IS GOING ON WITH THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE TROUGH EXCEPT FOR SOME CIRRUS. TODAY AND TONIGHT...THE UPPER RIDGING SEEN OVER THE DAKOTAS IS FORECAST TO MOVE OVER THE AREA TODAY...THEN TO LAKE ERIE TONIGHT... IN RESPONSE TO THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE PUSHING EAST. ALTHOUGH THIS SETUP PLACES THE FORECAST AREA UNDER SOUTHWEST FLOW ALOFT...TYPICALLY GOOD FOR PRECIPITATION...THE EXTENSIVE AMOUNT OF DRY AIR PRESENT WILL PREVENT ANY PRECIPITATION FROM OCCURRING. IN FACT...WE MAY NOT SEE MUCH CLOUD COVER BESIDES SOME SCATTERED HIGH CLOUDS MOVING ACROSS THIS AFTERNOON/EVENING... ASSOCIATED WITH THE ALBERTA/SASKATCHEWAN SHORTWAVE PASSING TO OUR NORTH. A WARM ADVECTION PATTERN WILL ENSUE THIS AFTERNOON AS THE CURRENT HIGH PRESSURE RIDGE MOVES EAST INTO THE GREAT LAKES REGION. 925MB TEMPS ARE PROGGED TO RANGE FROM -2C NORTH TO +2C SOUTH AT 18Z TODAY...ABOUT 3 TO 5C COOLER THAN YESTERDAY. THUS... HIGHS WILL BE A BIT COOLER DESPITE FULL SUNSHINE. THE WARM ADVECTION SHOULD INCREASE TONIGHT AS LOW PRESSURE BEGINS TO FORM NEAR RAPID CITY...ASSOCIATED WITH THE NEVADA SHORTWAVE LIFTING INTO WESTERN SOUTH DAKOTA. THE INCREASING SOUTHERLY FLOW WILL HELP KEEP TEMPERATURES UP...PARTICULARLY OVER THE HIGHER TERRAIN WEST OF THE MISSISSIPPI RIVER. NOTE THAT THE TYPICAL COLD SPOTS OF WISCONSIN COULD GET CHILLY...SINCE THE SOUTHERLY FLOW TAKES LONGER TO RAMP UP THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE WHICH HAS A GOOD HANDLE ON BOTH TEMPERATURE SITUATIONS. SATURDAY AND SATURDAY NIGHT...MODELS ARE IN GOOD AGREEMENT IN KEEPING THE AREA IN SOUTHWEST FLOW ALOFT...WITH THE CURRENT NEVADA SHORTWAVE FOLLOWING THE FLOW AND LIFTING INTO CENTRAL MINNESOTA BY 12Z SUNDAY. SURFACE PRESSURE GRADIENT IS PROGGED TO BE FAIRLY TIGHT THROUGHOUT THIS PERIOD...DUE TO THE DOWNSLOPING FLOW OFF THE ROCKIES KEEPING PRESSURES LOW ON THE LEE SIDE WHILE THE CURRENT HIGH PRESSURE AREA STRENGTHENS OVER THE EASTERN GREAT LAKES. THUS... BREEZY CONDITIONS ARE ON TAP. FORECAST 925MB WINDS ARE 25-30KT ON SATURDAY AND WITH WHAT LOOKS TO BE PLENTY OF SUN UNTIL SOME CIRRUS LATE IN THE DAY...SOME MIXING DOWN OF THOSE HIGHER WINDS CAN BE EXPECTED. GUSTS OF 20-25KT SEEMS LIKELY. REGARDING TEMPERATURES... 925MB READINGS ARE 4-6C AT 18Z...WHICH SHOULD PUT MOST LOCATIONS INTO THE 50S. FOR SATURDAY NIGHT...THERE ARE INDICATIONS OF MID AND HIGH CLOUDS INCREASING/THICKENING OVER THE FORECAST AREA AHEAD OF THE SHORTWAVE LIFTING INTO CENTRAL MINNESOTA. IN ADDITION... ISENTROPIC LIFT PLOTS ON THE 295-300K SURFACES SHOW WEAK LIFT FROM 650-780MB CENTERED MOSTLY WEST OF THE MISSISSIPPI RIVER AFTER 06Z. HOWEVER...PLENTIFUL DRY AIR EXISTS BELOW 800MB TO PREVENT PRECIPITATION...ESPECIALLY GIVEN ONLY WEAK LIFT EXPECTED. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE...STAYED ON THE WARM SIDE OF GUIDANCE FOR LOWS. SUNDAY AND SUNDAY NIGHT...THE SHORTWAVE IN CENTRAL MINNESOTA AT 12Z SUNDAY ALL MODELS HAVE LIFT TOWARDS THE THUNDER BAY ONTARIO AREA BY 00Z MONDAY...ALLOWING FOR A WEAK UPPER RIDGE TO BUILD INTO THE FORECAST AREA BEHIND IT IN THE GENERAL SOUTHWEST FLOW. THIS WEAK RIDGE MAY ALLOW FOR A LITTLE THINNING OF THE CLOUD COVER FROM SATURDAY NIGHT...RESULTING IN A PARTLY SUNNY DAY. 925MB TEMPS ARE PROGGED IN THE 4-7C RANGE...WHICH WOULD ALLOW LOCATIONS THAT HAVE MORE SUN TO APPROACH 60F. HAVE KEPT HIGH TEMPERATURES IN THE 50S FOR NOW DUE TO CLOUD COVER UNCERTAINTY. ANOTHER WEAK SHORTWAVE TROUGH IS PROGGED TO COME UP THROUGH THE SOUTHWEST FLOW AND REACH WESTERN PORTIONS OF IOWA AND MINNESOTA BY 12Z MONDAY. THIS TROUGH LOOKS TO HAVE A BETTER TAP INTO GULF OF MEXICO MOISTURE...THUS AT A MINIMUM AN EXTENSIVE STRATUS THROUGH MID AND HIGH CLOUD DECK IS LIKELY TO ACCOMPANY IT. HOWEVER...ISENTROPIC LIFT FORCING IS WEAK AT BEST... FOCUSED MAINLY AROUND 700MB ON THE 300K SURFACE AND BETWEEN 06-12Z MONDAY. AS SUCH...MODEL QPF FIELDS ARE QUITE LIGHT AND EVEN THE 16.00Z NAM KEEPS THE PRECIPITATION EVEN WEST OF THE FORECAST AREA. FOR NOW THERE REMAINS ENOUGH OF A SIGNAL TO MAINTAIN A 20 PERCENT CHANCE WEST OF THE MISSISSIPPI RIVER. WITH A SOUTHERLY BREEZE PERSISTING AND CLOUDS AROUND...ANOTHER MILD NIGHT FOR MID-NOVEMBER IS ON TAP...AND AGAIN FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...MONDAY THROUGH THANKSGIVING NIGHT 200 AM CST FRI NOV 16 2012 OVERALL...REALLY GOOD MODEL AGREEMENT EXISTS ON THE UPPER LEVEL AND SURFACE PATTERNS AMONGST 16.00Z GUIDANCE THROUGH ABOUT WEDNESDAY. THE PATTERN FEATURES THE PLAINS TROUGH SUNDAY NIGHT LIFTING UP INTO NORTHERN ONTARIO ON TUESDAY...FOLLOWED BY RIDGING BUILDING INTO THE FORECAST AREA FOR TUESDAY NIGHT INTO WEDNESDAY. 20-30 PERCENT CHANCES OF RAIN ARE MAINTAINED FOR MONDAY...ASSOCIATED WITH THE WEAK ISENTROPIC LIFT AND DPVA ASSOCIATED WITH THE PLAINS TROUGH. NOTE THAT ANY PRECIPITATION LOOKS MINIMAL AT THIS TIME...THUS THE LOW CHANCES. THERE MAY STILL BE SOME LINGERING PRECIPITATION IN THE FAR EASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT...THUS A 20 PERCENT CHANCE EXISTS THEN. DRY WEATHER FOLLOWS FOR TUESDAY INTO WEDNESDAY WITH THE UPPER RIDGE BUILDING IN AND SURFACE RIDGE IN PLACE. TEMPERATURES LOOK TO REMAIN ABOVE NORMAL...ESPECIALLY ON WEDNESDAY AS A SURGE OF DOWNSLOPED AIR OFF THE ROCKIES FLOWS INTO THE FORECAST AREA. THIS AIR IS CHARACTERIZED BY 850MB STANDARDIZED ANOMALIES OF 1.5 ABOVE NORMAL. THUS...HAVE LEANED TOWARDS THE WARMER ECMWF GUIDANCE FOR HIGHS...IN THE 55 TO 60 RANGE. THESE MAY NEED TO BE INCREASED IN FUTURE RUNS. FROM WEDNESDAY NIGHT THROUGH THANKSGIVING NIGHT...THERE IS A LITTLE MORE DISAGREEMENT WITH WHAT HAPPENS IN THE UPPER LEVELS. 15.12Z/16.00Z ECMWF ALLOWS A SHORTWAVE COMING OUT OF A NORTHEAST PACIFIC TROUGH AND TRACKS IT ALONG THE U.S./CANADIAN BORDER AND INTO LAKE SUPERIOR THANKSGIVING NIGHT. THIS SITUATION ALLOWS FOR A COLD FRONTAL PASSAGE ON THANKSGIVING...THOUGH THE TRUE COLDER AIR FILTERS IN DURING THE NIGHT TIME. ON THE OTHER HAND...THE 16.00Z GFS/GFS ENSEMBLES AND EXTRAPOLATION OF THE 16.00Z CANADIAN/UKMET PREFER TO HOLD UPPER RIDGING IN PLACE OVER THE FORECAST AREA. WITH THIS SCENARIO...THE WELL ABOVE NORMAL WARMTH SEEN ON WEDNESDAY WOULD PERSIST THROUGH THANKSGIVING NIGHT BEFORE A COLD FRONT PASSES ON FRIDAY. FOR NOW HAVE MAINTAINED A CONSENSUS SOLUTION GIVEN THE DIFFERENCES. EITHER SOLUTION HAS LITTLE MOISTURE TO WORK WITH SO A DRY FORECAST IS STILL ON TAP. && .AVIATION...TODAY AND TONIGHT 528 AM CST FRI NOV 16 2012 HIGH PRESSURE CENTERED OVER EAST-CENTRAL MINNESOTA WILL MOVE EAST FROM NORTHERN WISCONSIN TO EASTERN QUEBEC TODAY. AS THIS OCCURS...THE WINDS WILL SHIFT FROM THE NORTH TO THE EAST BY MID MORNING AND SOUTH BY EARLY AFTERNOON. WIND SPEEDS WILL REMAIN LESS THAN 10 KNOTS. THE 16.00Z TRIES TO BRING SOME 925 MB MOISTURE INTO KLSE AROUND 16.12Z. THIS MOISTURE IS SUPPOSED TO BE ALREADY ACROSS SOUTHERN WISCONSIN AND BOTH THE SATELLITE AND OBSERVATIONS DO NOT SUPPORT THIS. AS A RESULT...TRENDED THE FORECAST TOWARD THE NAM/WRF WHICH KEEPS CLEAR SKIES AT BOTH TAF SITES THROUGH 17.12Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 200 AM CST FRI NOV 16 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
200 AM CST FRI NOV 16 2012 .SHORT TERM...THROUGH SUNDAY NIGHT 200 AM CST FRI NOV 16 2012 MAIN FORECAST FOCUS IS ON CLOUD COVER AND TEMPERATURES WITH A QUIET WEATHER PATTERN IN PLACE. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING FROM NEW MEXICO INTO THE DAKOTAS...A SHORTWAVE OVER NEVADA...AND SHORTWAVE TROUGHS OVER FAR SOUTHERN ALBERTA INTO SASKATCHEWAN...AS WELL AS OVER INDIANA. THE FORECAST AREA LIES IN SUBSIDENCE AND DRYING BEHIND THE LATTER SHORTWAVE TROUGH. 00Z MPX AND ABR SOUNDINGS WERE QUITE DRY WITH PRECIPITABLE WATER VALUES AROUND 0.17 INCHES AND DEWPOINT DEPRESSIONS OF 10C OR MORE THROUGHOUT. THE SUBSIDENCE WAS NOTED AT THE SURFACE BY HIGH PRESSURE WHICH STRETCHES FROM KANSAS INTO NORTHERN ONTARIO. THE CLEAR SKIES...LIGHT WINDS AND DRY AIR ASSOCIATED THEN WITH THIS RIDGE HAS ALLOWED TEMPERATURES TO DROP INTO THE 20S AT MOST LOCATIONS. TO THE WEST...LITTLE IS GOING ON WITH THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE TROUGH EXCEPT FOR SOME CIRRUS. TODAY AND TONIGHT...THE UPPER RIDGING SEEN OVER THE DAKOTAS IS FORECAST TO MOVE OVER THE AREA TODAY...THEN TO LAKE ERIE TONIGHT... IN RESPONSE TO THE SOUTHERN ALBERTA/SASKATCHEWAN SHORTWAVE PUSHING EAST. ALTHOUGH THIS SETUP PLACES THE FORECAST AREA UNDER SOUTHWEST FLOW ALOFT...TYPICALLY GOOD FOR PRECIPITATION...THE EXTENSIVE AMOUNT OF DRY AIR PRESENT WILL PREVENT ANY PRECIPITATION FROM OCCURRING. IN FACT...WE MAY NOT SEE MUCH CLOUD COVER BESIDES SOME SCATTERED HIGH CLOUDS MOVING ACROSS THIS AFTERNOON/EVENING... ASSOCIATED WITH THE ALBERTA/SASKATCHEWAN SHORTWAVE PASSING TO OUR NORTH. A WARM ADVECTION PATTERN WILL ENSUE THIS AFTERNOON AS THE CURRENT HIGH PRESSURE RIDGE MOVES EAST INTO THE GREAT LAKES REGION. 925MB TEMPS ARE PROGGED TO RANGE FROM -2C NORTH TO +2C SOUTH AT 18Z TODAY...ABOUT 3 TO 5C COOLER THAN YESTERDAY. THUS... HIGHS WILL BE A BIT COOLER DESPITE FULL SUNSHINE. THE WARM ADVECTION SHOULD INCREASE TONIGHT AS LOW PRESSURE BEGINS TO FORM NEAR RAPID CITY...ASSOCIATED WITH THE NEVADA SHORTWAVE LIFTING INTO WESTERN SOUTH DAKOTA. THE INCREASING SOUTHERLY FLOW WILL HELP KEEP TEMPERATURES UP...PARTICULARLY OVER THE HIGHER TERRAIN WEST OF THE MISSISSIPPI RIVER. NOTE THAT THE TYPICAL COLD SPOTS OF WISCONSIN COULD GET CHILLY...SINCE THE SOUTHERLY FLOW TAKES LONGER TO RAMP UP THERE. GENERALLY FOLLOWED A BLEND OF GUIDANCE WHICH HAS A GOOD HANDLE ON BOTH TEMPERATURE SITUATIONS. SATURDAY AND SATURDAY NIGHT...MODELS ARE IN GOOD AGREEMENT IN KEEPING THE AREA IN SOUTHWEST FLOW ALOFT...WITH THE CURRENT NEVADA SHORTWAVE FOLLOWING THE FLOW AND LIFTING INTO CENTRAL MINNESOTA BY 12Z SUNDAY. SURFACE PRESSURE GRADIENT IS PROGGED TO BE FAIRLY TIGHT THROUGHOUT THIS PERIOD...DUE TO THE DOWNSLOPING FLOW OFF THE ROCKIES KEEPING PRESSURES LOW ON THE LEE SIDE WHILE THE CURRENT HIGH PRESSURE AREA STRENGTHENS OVER THE EASTERN GREAT LAKES. THUS... BREEZY CONDITIONS ARE ON TAP. FORECAST 925MB WINDS ARE 25-30KT ON SATURDAY AND WITH WHAT LOOKS TO BE PLENTY OF SUN UNTIL SOME CIRRUS LATE IN THE DAY...SOME MIXING DOWN OF THOSE HIGHER WINDS CAN BE EXPECTED. GUSTS OF 20-25KT SEEMS LIKELY. REGARDING TEMPERATURES... 925MB READINGS ARE 4-6C AT 18Z...WHICH SHOULD PUT MOST LOCATIONS INTO THE 50S. FOR SATURDAY NIGHT...THERE ARE INDICATIONS OF MID AND HIGH CLOUDS INCREASING/THICKENING OVER THE FORECAST AREA AHEAD OF THE SHORTWAVE LIFTING INTO CENTRAL MINNESOTA. IN ADDITION... ISENTROPIC LIFT PLOTS ON THE 295-300K SURFACES SHOW WEAK LIFT FROM 650-780MB CENTERED MOSTLY WEST OF THE MISSISSIPPI RIVER AFTER 06Z. HOWEVER...PLENTIFUL DRY AIR EXISTS BELOW 800MB TO PREVENT PRECIPITATION...ESPECIALLY GIVEN ONLY WEAK LIFT EXPECTED. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE...STAYED ON THE WARM SIDE OF GUIDANCE FOR LOWS. SUNDAY AND SUNDAY NIGHT...THE SHORTWAVE IN CENTRAL MINNESOTA AT 12Z SUNDAY ALL MODELS HAVE LIFT TOWARDS THE THUNDER BAY ONTARIO AREA BY 00Z MONDAY...ALLOWING FOR A WEAK UPPER RIDGE TO BUILD INTO THE FORECAST AREA BEHIND IT IN THE GENERAL SOUTHWEST FLOW. THIS WEAK RIDGE MAY ALLOW FOR A LITTLE THINNING OF THE CLOUD COVER FROM SATURDAY NIGHT...RESULTING IN A PARTLY SUNNY DAY. 925MB TEMPS ARE PROGGED IN THE 4-7C RANGE...WHICH WOULD ALLOW LOCATIONS THAT HAVE MORE SUN TO APPROACH 60F. HAVE KEPT HIGH TEMPERATURES IN THE 50S FOR NOW DUE TO CLOUD COVER UNCERTAINTY. ANOTHER WEAK SHORTWAVE TROUGH IS PROGGED TO COME UP THROUGH THE SOUTHWEST FLOW AND REACH WESTERN PORTIONS OF IOWA AND MINNESOTA BY 12Z MONDAY. THIS TROUGH LOOKS TO HAVE A BETTER TAP INTO GULF OF MEXICO MOISTURE...THUS AT A MINIMUM AN EXTENSIVE STRATUS THROUGH MID AND HIGH CLOUD DECK IS LIKELY TO ACCOMPANY IT. HOWEVER...ISENTROPIC LIFT FORCING IS WEAK AT BEST... FOCUSED MAINLY AROUND 700MB ON THE 300K SURFACE AND BETWEEN 06-12Z MONDAY. AS SUCH...MODEL QPF FIELDS ARE QUITE LIGHT AND EVEN THE 16.00Z NAM KEEPS THE PRECIPITATION EVEN WEST OF THE FORECAST AREA. FOR NOW THERE REMAINS ENOUGH OF A SIGNAL TO MAINTAIN A 20 PERCENT CHANCE WEST OF THE MISSISSIPPI RIVER. WITH A SOUTHERLY BREEZE PERSISTING AND CLOUDS AROUND...ANOTHER MILD NIGHT FOR MID-NOVEMBER IS ON TAP...AND AGAIN FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...MONDAY THROUGH THANKSGIVING NIGHT 200 AM CST FRI NOV 16 2012 OVERALL...REALLY GOOD MODEL AGREEMENT EXISTS ON THE UPPER LEVEL AND SURFACE PATTERNS AMONGST 16.00Z GUIDANCE THROUGH ABOUT WEDNESDAY. THE PATTERN FEATURES THE PLAINS TROUGH SUNDAY NIGHT LIFTING UP INTO NORTHERN ONTARIO ON TUESDAY...FOLLOWED BY RIDGING BUILDING INTO THE FORECAST AREA FOR TUESDAY NIGHT INTO WEDNESDAY. 20-30 PERCENT CHANCES OF RAIN ARE MAINTAINED FOR MONDAY...ASSOCIATED WITH THE WEAK ISENTROPIC LIFT AND DPVA ASSOCIATED WITH THE PLAINS TROUGH. NOTE THAT ANY PRECIPITATION LOOKS MINIMAL AT THIS TIME...THUS THE LOW CHANCES. THERE MAY STILL BE SOME LINGERING PRECIPITATION IN THE FAR EASTERN PORTIONS OF THE FORECAST AREA MONDAY NIGHT...THUS A 20 PERCENT CHANCE EXISTS THEN. DRY WEATHER FOLLOWS FOR TUESDAY INTO WEDNESDAY WITH THE UPPER RIDGE BUILDING IN AND SURFACE RIDGE IN PLACE. TEMPERATURES LOOK TO REMAIN ABOVE NORMAL...ESPECIALLY ON WEDNESDAY AS A SURGE OF DOWNSLOPED AIR OFF THE ROCKIES FLOWS INTO THE FORECAST AREA. THIS AIR IS CHARACTERIZED BY 850MB STANDARDIZED ANOMALIES OF 1.5 ABOVE NORMAL. THUS...HAVE LEANED TOWARDS THE WARMER ECMWF GUIDANCE FOR HIGHS...IN THE 55 TO 60 RANGE. THESE MAY NEED TO BE INCREASED IN FUTURE RUNS. FROM WEDNESDAY NIGHT THROUGH THANKSGIVING NIGHT...THERE IS A LITTLE MORE DISAGREEMENT WITH WHAT HAPPENS IN THE UPPER LEVELS. 15.12Z/16.00Z ECMWF ALLOWS A SHORTWAVE COMING OUT OF A NORTHEAST PACIFIC TROUGH AND TRACKS IT ALONG THE U.S./CANADIAN BORDER AND INTO LAKE SUPERIOR THANKSGIVING NIGHT. THIS SITUATION ALLOWS FOR A COLD FRONTAL PASSAGE ON THANKSGIVING...THOUGH THE TRUE COLDER AIR FILTERS IN DURING THE NIGHT TIME. ON THE OTHER HAND...THE 16.00Z GFS/GFS ENSEMBLES AND EXTRAPOLATION OF THE 16.00Z CANADIAN/UKMET PREFER TO HOLD UPPER RIDGING IN PLACE OVER THE FORECAST AREA. WITH THIS SCENARIO...THE WELL ABOVE NORMAL WARMTH SEEN ON WEDNESDAY WOULD PERSIST THROUGH THANKSGIVING NIGHT BEFORE A COLD FRONT PASSES ON FRIDAY. FOR NOW HAVE MAINTAINED A CONSENSUS SOLUTION GIVEN THE DIFFERENCES. EITHER SOLUTION HAS LITTLE MOISTURE TO WORK WITH SO A DRY FORECAST IS STILL ON TAP. && .AVIATION...THROUGH 06Z SATURDAY 1059 PM CST THU NOV 15 2012 VFR CONDITIONS WITH CLEAR SKIES EXPECTED THROUGH THE TAF PERIOD. SURFACE HIGH PRESSURE WILL DRIFT ACROSS THE TAF SITES TONIGHT AND INTO EASTERN WISCONSIN/LAKE MICHIGAN BY LATE FRIDAY EVENING. LIGHT NORTHERLY WINDS WILL COME AROUND TO THE EAST AND THEN FINALLY THE SOUTHEAST BY FRIDAY AFTERNOON...BUT REMAIN BELOW 12 KNOTS. && .ARX WATCHES/WARNINGS/ADVISORIES... 200 AM CST FRI NOV 16 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...RABERDING
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1237 AM EST SUN NOV 18 2012 .AVIATION... THE ISOLATED SHOWERS WILL CONTINUE TO AFFECT THE KPBI TAF SITE THROUGH TODAY...DUE TO THE FRONTAL BOUNDARY REMAINING NEARLY STATIONARY OVER THIS AREA. REST OF THE TAF SITES ACROSS SOUTH FLORIDA SHOULD REMAIN DRY TODAY. SO WILL KEEP A VCSH IN THE TAF SITE FOR KPBI. THE WINDS WILL ALSO BE LIGHT AND VARIABLE ACROSS THE EAST COAST TAF SITES EARLY THIS MORNING...BEFORE SWINGING TO A 10 TO 30 DEGREE DIRECTION WITH SPEEDS AROUND 10 MPH THROUGH 00Z MONDAY. AT KAPF TAF SITE...THE WIND SPEEDS WILL BE AROUND 10 MPH TODAY FROM THE NORTH TO NORTHEAST DIRECTION. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS TODAY AT ALL OF THE TAF SITES. && .AVIATION...54/BNB .PREV DISCUSSION... /ISSUED 1015 PM EST SAT NOV 17 2012/ UPDATE... NO MAJOR UPDATES TO THE PREVIOUS FORECAST ARE EXPECTED THIS EVENING. THE EVENING SURFACE ANALYSIS SHOWED A LINGERING WEAK TROUGH OR WHAT IS LEFT OF AN OLD FRONTAL BOUNDARY JUST EAST OF THE FLORIDA PENINSULA WITH LIGHT TO MODERATE NORTHEAST FLOW CONTINUING. ENHANCED LOW-LEVEL CONVERGENCE NEAR AND AROUND THIS SURFACE FEATURE COMBINED WITH BELOW AVERAGE MID/UPPER-LEVEL TEMPERATURES WILL MAINTAIN THE CHANCE FOR MAINLY ISOLATED SHOWERS OVER THE ADJACENT ATLANTIC WATERS AND COASTAL AREAS THROUGH THE OVERNIGHT HOURS. SIMILAR TO THE PAST FEW NIGHTS...INLAND FOG WILL BE POSSIBLE THROUGH THE OVERNIGHT HOURS ACROSS THE INTERIOR AREAS. THE LATEST SREF MODEL PROBABILITIES SUPPORT THIS AND INDICATE A GOOD PORTION OF THIS INTERIOR AREA AROUND AND SOUTH OF THE LAKE DIPPING INTO THE 1-3 MILE VISIBILITY RANGE BY DAYBREAK SUNDAY. 85/AG && PREV DISCUSSION... /ISSUED 644 PM EST SAT NOV 17 2012/ AVIATION... AS A STALLED FRONTAL BOUNDARY LINGERS JUST OFFSHORE THE ATLANTIC COAST...ISOLATED SHOWERS WILL REMAIN ACROSS THE AREA THROUGH THE NIGHT AND IS DEPICTED BY THE LATEST HRRR GUIDANCE. SHOWERS COULD BRIEFLY AFFECT ONE OR MORE EAST COAST SITES THROUGH THE EVENING WITH MVFR CONDITIONS BUT WOULD BE VERY BRIEF AND DECIDED NOT TO PREVAIL ANY SHRA MENTION. MID LEVEL DRYING EXPECTED TO PUSH INTO THE SOUTH FLORIDA PENINSULA FROM THE NORTH THROUGH THE LATTER HALF OF THE PERIOD. && PREV DISCUSSION... /ISSUED 246 PM EST SAT NOV 17 2012/ DISCUSSION... SHORT TERM...THE BASIC SYNOPTIC SETUP OVER THE AREA IS A NORTHWESTERLY FLOW OVER THE CWA AS HIGH PRESSURE TO THE NORTH SLOWLY PUSHES A LOW PRESSURE SYSTEM WELL TO THE SOUTHEAST EASTWARD. THERE IS A STALLED BOUNDARY THAT CONTINUES TO LAY ACROSS THE OFFSHORE WATERS IN THE ATLANTIC. THE HIGH, CENTERED OVER NEW ENGLAND, IS VERY SLOWLY CAUSING THE BOUNDARY TO DRIFT TO THE EAST AND HAS PUSHED MOST OF THE SHOWERS AWAY FROM THE CWA. THIS BOUNDARY WILL NOT GO FAR, HOWEVER, AS THERE IS NO REAL PUSH NORMAL TO THE BOUNDARY. RATHER, THE FLOW IS ALMOST PARALLEL TO THE BOUNDARY. SO, WITH STILL PLENTY OF MOISTURE REMAINING OVER THE MAINLAND, DAYTIME HEATING WILL CAUSE SOME ISOLATED SHOWERS TO DEVELOP. MODELS ARE INDICATING MOST OF ANY CONVECTION WILL BE LOCATED MAINLY OFF SHORE. THIS PATTERN WILL BE IN PLACE FOR THE REMAINDER OF THE WEEKEND. OVER THE NEXT COUPLE OF DAYS, THE LOW WILL SLOWLY MOVE TO THE NORTH AS THE HIGH PRESSURE SLIDES WELL TO THE NORTHEAST. THE LOW WILL THEN DEEPEN AND INTERACT WITH THE STALLED BOUNDARY, TURNING IT INTO A COLD FRONT. THIS COULD ALLOW FOR SOME SHOWERS OVER THE ATLANTIC TO DEVELOP, BUT STILL LOOK ISOLATED AT BEST THROUGH 12Z TUESDAY. ALSO, WITH THE LOW DEVELOPING NEXT WEEK, SOMEWHAT COOLER, DRIER AIR WILL TRY TO MAKE ITS WAY DOWN THE FLORIDA PENINSULA. WHILE THE TEMPERATURES WILL ONLY COOL A COUPLE OF DEGREES, THE DEW POINTS SHOULD DROP AROUND 5 DEGREES, ALLOWING THE AIR TO FEEL SOMEWHAT DRIER FOR THE BEGINNING OF THE WEEK. LONG TERM...TUESDAY THROUGH FRIDAY...DRY AND STABLE AIR OVER S FLA TUESDAY PRECLUDES PRECIPITATION EXCEPT FOR THE E COAST. BY WEDNESDAY THE APPROACHING UPPER TROUGH SHOVES A COLD FRONT TOWARD S FLA THAT MOVES THROUGH THE AREA WEDNESDAY WITH SOME SHOWER ACTIVITY. THURSDAY AND FRIDAY WILL BE DRY BUT COOLER. LOWS THURSDAY WILL RANGE FROM NEAR 50 W OF LAKE OKEECHOBEE TO THE LOWER 60S SE WITH SLIGHTLY WARMER TEMPERATURES FRIDAY MORNING. HIGHS WILL BE IN THE 70S THURSDAY AND FRIDAY. MARINE... NNE TO NE WINDS AT 10 TO 15 KTS THROUGH MONDAY THEN SHIFTING MORE NORTHERLY AND SLIGHTLY DECREASING TUESDAY BEFORE INCREASING FROM THE NW WEDNESDAY BEHIND THE FRONT WITH MARINE CONDITIONS DETERIORATING. SOME RISK OF RIP CURRENTS POSSIBLE E COAST TODAY...SUNDAY AND MONDAY. WATERSPOUTS POSSIBLE ATLC WATERS TODAY AS OFFSHORE FLOW CONVERGING WITH THE EASTERLY ATLC FLOW OFFSHORE. FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE CURRENTLY ANTICIPATED. LOW PRESSURE TO THE SOUTH, WILL SLOWLY MOVE TO THE NORTH, WELL EAST OF THE BAHAMAS. THIS WILL ALLOW SLIGHTLY DRIER AIR TO MOVE IN NEXT WEEK, WITH SLIGHTLY COOLER TEMPERATURES AS WELL. WINDS, OVER THE NEXT FEW DAYS, WILL CONTINUE TO BE OUT OF THE NORTH NORTHEAST BETWEEN 5 AND 10 KTS. THEY WILL BECOME MORE NORTH TO NORTHWESTERLY BY MONDAY, STILL BETWEEN 5 AND 10KTS. AS FOR MINIMUM RH, EXPECT RH`S IN THE MID 50 PERCENT RANGE FOR THE WEEKEND, DROPPING INTO THE MID 40 TO LOW 50 PERCENT RANGE BEGINNING NEXT WEEK. RECOVERIES SHOULD CONTINUE TO BE GOOD EVERY NIGHT, REACHING INTO THE 90 PERCENT RANGE. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 63 79 64 79 / 10 - - 10 FORT LAUDERDALE 65 79 65 80 / 10 10 - 10 MIAMI 65 79 65 79 / 10 - - 10 NAPLES 61 75 62 78 / 10 - - - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...15/JR AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS LINCOLN IL
307 AM CST SUN NOV 18 2012 .DISCUSSION... ISSUED 250 AM CST SUN NOV 18 2012 CURRENT WEATHER PATTERN NOT MUCH DIFFERENT THAN 24 HRS AGO...WITH AN UPPER LOW OVER THE EXTREME SERN US...AND HIGH PRESSURE RIDGE FROM SERN CANADA TO THE CENTRAL GULF COAST. SFC WINDS IN THE OVERNIGHT LIGHTER...BUT PREDOMINANTLY OUT OF THE S/SE AS THE SUN COMES UP. FORECAST IS ESSENTIALLY ONE OF TEMPERATURES. TWO WAVES ARE PROGGED TO MOVE THROUGH THE QUASI ZONAL FLOW...MON/MON NIGHT...AND AGAIN LATER IN THE WEEK...BUT THE MODELS ARE SKETCHY WITH CONSISTENCY...AND THE ATMOSPHERE WILL BE STRUGGLING TO PRODUCE MOISTURE. AS A RESULT...THE ZONE FORECAST IS RUNNING DRY AT THE MOMENT. TEMPERATURES RUNNING ABOVE NORMAL THROUGH MIDWEEK. SHORT TERM...TODAY AND TOMORROW... RATHER QUIET WEATHER AND S/SERLY WINDS AT THE SFC WITH HIGH PRESSURE RIDGE OVER THE EASTERN HALF OF THE COUNTRY. MILD TEMPS CONTINUE...APPROACHING LOW 60S FOR MUCH OF THE AREA. MOSTLY SUNNY SKIES...AND CLEAR OVERNIGHT WILL COUNTER THE SOUTHERLY FLOW WITH RATHER EFFECTIVE RADIATIONAL COOLING AND TEMPS DROPPING INTO THE UPPER 30S AND NEAR 40. SOUTHERLY WINDS PICK UP A BIT ON MONDAY...AND A BROAD AREA OF WAA PUSHES UNSEASONABLE HEAT INTO THE SW AND CENTRAL PORTIONS OF THE COUNTRY. TEMPS MONDAY A BIT AHEAD OF GUIDANCE...AS THE SLOW WARMING TREND CONTINUES ACROSS THE MIDWEST. LONG TERM...TUESDAY THROUGH SATURDAY... HIGH PRESSURE RIDGE SLOWLY DRIFTS EASTWARD AND THE CLOSED UPPER LOW KICKS OUT OF THE SE. A SHORT WAVE RIPPLES THROUGH THE UPPER ATMOSPHERE...BRINGING A CHANCE FOR SHOWERS MON/MON NIGHT. AND THOUGH THE GFS AND THE NAM ARE BOTH PORTRAYING SOME QPF FOR THE REGION...KEEPING THE POPS RELATIVELY LOW...IN THE SLIGHT CHANCE CAT...AND LACK OF COVERAGE POTENTIAL IF NOTHING ELSE. MOISTURE IS SOMEWHAT LACKING THROUGH THE LAYER AHEAD OF THE SYSTEM. SOUTHERLY WINDS PRIOR TO MONDAY NOT PROVIDING MUCH MOISTURE TRANSPORT INTO THE AREA. WINDS START TO PICK UP A BIT ON MON WITH AN APPROACHING STORM SYSTEM...BUT STILL NOT MUCH IN EXCESS OF 10 KTS. MODELS HAVING A BIT OF AN ISSUE WITH THE WAVE ITSELF...WITH THE ECMWF HOLDING BACK A BIT AND PASSING A MORE VIGOROUS PIECE OF ENERGY LATER ON TUESDAY...ALBEIT A BIT OF AN OUTLIER. WILL WATCH CAREFULLY. ON THE OTHER SIDE OF THE CHANCES FOR SHOWERS MON...THE WARMING TREND CONTINUES THROUGH MID WEEK. 850MB TEMPS AT 6-7C WILL HAVE THE POTENTIAL TO TRANSLATE INTO UPPER 50S/LOWER 60S. GUIDANCE HAS NOT COMPLETELY LATCHED ONTO THE WARMING TREND...THOUGH THE MODEL FIELDS CLEARLY SHOW THE THERMAL RIDGE IN THE WESTERN CONUS DEEPENING AND SLOWLY CREEPING INTO THE MIDWEST. HAVE BUMPED MAX TEMPS A FEW DEGREES AHEAD OF ALLBLEND FOR MON- WED...AND A BIT ON THURSDAY. THURSDAY MAY BE COMPLICATED BY AN APPROACHING STORM SYSTEM AND ASSOCIATED CLOUD COVER...BUT SYSTEM STILL HAS A BIT OF UNCERTAINTY AND WOULD ALSO HAVE THE SAME PROBLEM AS MONDAYS WAVE WITH SCANT MOISTURE. KEEPING THE POPS LOW AND THE TEMPS A COUPLE OF DEGREES ABOVE GUIDANCE...BUT MODERATE FOR NOW. HJS && .AVIATION... ISSUED 1137 PM CST SAT NOV 17 2012...FOR THE 06Z TAFS FORECAST RAP SOUNDINGS ARE STILL INDICATING MVFR VIS OF 4-5SM BR WILL BE POSSIBLE LATER TONIGHT. BASED ON A SIMILAR AIRMASS TO LAST NIGHT...WE KEPT A MENTION OF MVFR FOG AT ALL BUT BMI FOR SEVERAL HOURS FROM 10/11Z TO 15/16Z. CIRRUS CLOUDS HAVE MAINLY CLEARED OUT TO THE EAST...SO RADIATIONAL COOLING CONDITIONS WILL SUPPORT OUR AIR TEMPS DIPPING TO NEAR THE WET BULB LATER TONIGHT. LIGHT SOUTHEAST OR CALM WINDS WILL PREVAIL DUE TO THE WEAK PRESSURE GRADIENT AND THE PROXIMITY OF THE SURFACE RIDGE AXIS ACROSS OUR SOUTHEASTERN COUNTIES. LITTLE CHANGE IS EXPECTED FOR SUNDAY...WITH SOUTHEAST WINDS LESS THAN 10KT AND PERIODIC CIRRUS CLOUDS. SHIMON && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1137 PM CST SAT NOV 17 2012 .DISCUSSION... ISSUED 900 PM CST SAT NOV 17 2012 THE LARGE SURFACE HIGH EXTENDING FROM MAINE TO EASTERN TEXAS WILL BE IN CONTROL OF OUR WEATHER OVERNIGHT. THE RIDGE AXIS EXTENDS ACROSS OUR FAR EASTERN COUNTIES...WHICH WILL HELP KEEP WINDS LIGHT SOUTHEAST OR CALM OVERNIGHT. CIRRUS CLOUDS MAY DRIFT ACROSS THE SKY OCCASIONALLY TONIGHT...BUT ENOUGH CLEARING SHOULD DEVELOP TO PROVIDE FAVORABLE RADIATIONAL COOLING CONDITIONS. THAT WILL ALLOW TEMPS TO DIP INTO THE LOWER 30S BY SUNRISE SUNDAY. SOME LIGHT FOG MAY DEVELOP LATE TONIGHT...BUT VISIBILITY SHOULD REMAIN 4SM OR BETTER...SO NO REAL NEED TO ADD TO THE GRIDS AS IMPACT WILL BE NEGLIGIBLE. AS THE RIDGE AXIS SHIFTS FARTHER EAST OF ILLINOIS SUNDAY MORNING...MID LEVEL TEMPS WILL BEGIN WARMING ON INCREASING SOUTHERLY WINDS. THAT WILL HELP PUSH HIGH TEMPS A FEW DEGREES WARMER THAN SATURDAY. OUR LOW TEMP FORECAST TONIGHT LOOKED ON TRACK WITH EXPECTED CONDITIONS. NO CHANGES APPEARED NECESSARY IN THE REMAINING GRIDS FOR TONIGHT OR EARLY TOMORROW. NO FORMAL UPDATE WILL BE NEEDED THIS EVENING. SHIMON && .AVIATION... ISSUED 1137 PM CST SAT NOV 17 2012...FOR THE 06Z TAFS FORECAST RAP SOUNDINGS ARE STILL INDICATING MVFR VIS OF 4-5SM BR WILL BE POSSIBLE LATER TONIGHT. BASED ON A SIMILAR AIRMASS TO LAST NIGHT...WE KEPT A MENTION OF MVFR FOG AT ALL BUT BMI FOR SEVERAL HOURS FROM 10/11Z TO 15/16Z. CIRRUS CLOUDS HAVE MAINLY CLEARED OUT TO THE EAST...SO RADIATIONAL COOLING CONDITIONS WILL SUPPORT OUR AIR TEMPS DIPPING TO NEAR THE WET BULB LATER TONIGHT. LIGHT SOUTHEAST OR CALM WINDS WILL PREVAIL DUE TO THE WEAK PRESSURE GRADIENT AND THE PROXIMITY OF THE SURFACE RIDGE AXIS ACROSS OUR SOUTHEASTERN COUNTIES. LITTLE CHANGE IS EXPECTED FOR SUNDAY...WITH SOUTHEAST WINDS LESS THAN 10KT AND PERIODIC CIRRUS CLOUDS. SHIMON && .PREV DISCUSSION... ISSUED 246 PM CST SAT NOV 17 2012 ANOTHER DAY OF NOT MUCH TO TALK ABOUT WITH ONLY CONCERN BEING PCPN CHANCES MON AND MON NIGHT...AND HOW WARM WILL IT GET THROUGH THE PERIOD. MODELS IN THE SHORT TERM REMAIN SIMILAR AND CONSISTENT FROM PREVIOUS RUNS...SO ONLY MAKING MINOR CHANGES TO GOING FORECAST THROUGH TUESDAY. MODELS IN THE LONG TERM CONTINUE TO SHOW DIFFERENCES IN TIMING WITH THE ONE SHORT WAVE/SYSTEM THAT MOVES ACROSS THE AREA ON THANKSGIVING DAY/NIGHT. SO CONFIDENCE HAS NOT CHANGED FROM PREVIOUS FORECASTS. SHORT TERM...TONIGHT THROUGH TUESDAY HIGH PRSS RIDGE OVER THE AREA WILL SLIDE SOUTHEAST TONIGHT AND TOMORROW. THIS SHOULD ALLOW WAA TO OCCUR BACK INTO THE AREA AND AN INCREASE OF LOW LEVEL MOISTURE. HOWEVER...SFC RIDGE WILL EXTEND INTO THE GULF AND CUTOFF ANY RETURN OF MOISTURE TO THE AREA EARLY NEXT WEEK. SO THE FRONTAL SYSTEM THAT IS MOVING TOWARD AND INTO THE AREA MON NIGHT THROUGH TUE WILL HAVE VERY LIMITED MOISTURE TO WORK WITH. SO WILL KEEP CURRENT FORECAST PRETTY CLOSE TO AS IS AND STILL HAVE SLIGHT CHC FOR SHOWERS IN THE WEST FOR MONDAY AND ACROSS THE WHOLE AREA FOR MONDAY NIGHT. ANY PCPN SHOULD BE WELL IN THE WARM SECTOR SO AS THE FRONT MOVES INTO THE AREA FOR TUESDAY...ANY PCPN WILL BE JUST EAST OF THE STATE. DAYTIME TEMPS WILL BE ABOVE NORMAL ACROSS THE AREA. FOLLOWED WARMER GUIDANCE...MET...FOR SUNDAY AND THEN BLEND FOR MONDAY AND TUESDAY. SHOULD BE PLENTY OF SUNSHINE TOMORROW...THEN WILL HAVE TO RELY ON WAA ON MONDAY AND TUESDAY...WHICH WILL HAVE LITTLE MORE CLOUD COVER. LONG TERM...TUESDAY NIGHT THROUGH SATURDAY STILL LOOKING AT A SOMEWHAT ZONAL PATTERN FOR REMAINDER OF THE WEEK. BOTH MODELS SHOW A TROUGH/FRONTAL SYSTEM MOVING THROUGH THE AREA THURSDAY-THURSDAY NIGHT...BUT TIMING DIFFERENCES HAVE GFS QUICKER THAN ECMWF. ECMWF IS ALSO DEEPER WITH MID LEVEL TROUGH THURSDAY NIGHT. SO WITH TIMING DIFFERENCES...WILL KEEP SLIGHT CHC POPS IN GRIDS FOR THURSDAY NIGHT IN SOUTHEAST CWA...WHICH IS CLOSE TO GOING FORECAST. REMAINDER OF THE TIME PERIOD WILL BE DRY AS MOISTURE WILL REMAIN CUTOFF BY THE SFC RIDGE SITTING OVER THE SOUTHEASTERN US AND INTO THE WESTERN GULF. TEMPS WILL REMAIN WARM/ABOVE NORMAL WED AND THURSDAY...BUT THEN COOL SOME FOR FRIDAY AND SAT...THOUGH STILL SLIGHTLY ABOVE NORMAL. AUTEN && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
145 AM MST SUN NOV 18 2012 .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 145 AM MST SUN NOV 18 2012 SUMMARY...DRY WEATHER WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE SHORT TERM PART OF FORECAST. TODAY...DEW POINT DEPRESSIONS CONTINUE TO LOWER EARLY THIS MORNING. LATEST FOG PRODUCT SATELLITE IMAGERY DOES NOT SHOW ANY EVIDENCE OF FOG FORMATION YET...BUT WITH LIGHT SURFACE WINDS...EXPECT SOME PATCHY FOG TO DEVELOP SHORTLY BEFORE SUNRISE MAINLY ALONG HIGHWAY 83. LATEST HRRR MODEL SUPPORTS THIS. OTHERWISE...A WEAK SHORTWAVE TROUGH WILL MOVE ACROSS THE FORECAST AREA DURING THE DAY...BUT RAOBS/MODELS CONTINUE TO SHOW THAT THE AIR MASS WILL BE DRY. ONLY MID AND HIGH LEVEL CLOUDS WILL ADVECT ACROSS THE AREA THIS AFTERNOON. LEE SIDE SURFACE TROUGH WILL MOVE EAST THIS AFTERNOON AND WILL SWITCH WINDS TO THE WEST ALONG THE COLORADO/KANSAS BORDER. WITH LACK OF AIR MASS CHANGE...EXPECT TEMPERATURES TO BE SIMILAR TO THOSE THAT OCCURRED SATURDAY. TONIGHT...500 MB FLOW BECOMES INCREASINGLY ZONAL BEGINNING TONIGHT. MODELS SHOW WEAK COLD AIR ADVECTION AT THE SURFACE STARTING AROUND 12Z. MONDAY...DRY ZONAL MID LEVEL FLOW WILL CONTINUE. SURFACE WINDS WILL BE NORTH BEHIND A PUSH OF SLIGHTLY COOLER AIR. ALTHOUGH 850 MB TEMPERATURES COOL...THE COOLING IS VERY SLIGHT...ONLY ABOUT 1 DEGREE CELSIUS. ONCE AGAIN...PERSISTENCE TEMPERATURE FORECASTS LOOK DECENT. MONDAY NIGHT THROUGH TUESDAY NIGHT...500 MB RIDGE AND ASSOCIATED SUBSIDENCE WILL DEVELOP OVER THE HIGH PLAINS. LEE SIDE TROUGH WILL REFORM BY TUESDAY AFTERNOON BRINGING A RETURN OF SOUTH WINDS AND WEAK WARM AIR ADVECTION. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 145 AM MST SUN NOV 18 2012 VERY LITTLE HAS CHANGED IN THE EXTENDED PERIODS WITH MODELS STILL ADVERTISING PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK ALONG US/CANADA BORDER. THERE ARE A FEW WEAK SHORTWAVE TROUGHS THAT COME CLOSE TO THE CWA...HOWEVER WITH A DEEP DRY LAYER IN PLACE THE MOST WE WOULD EXPECT TO SEE IS AN INCREASE IN MID-HIGH CLOUDS. RH VALUES STILL LOOK TO BE NEAR RFW CRITERIA WEDNESDAY AFTERNOON...HOWEVER SURFACE GRADIENT IS WEAK OVER THE CWA AND WINDS SHOULD BE WELL BELOW CRITERIA. OVERALL...STILL EXPECTING ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS TO CONTINUE. WED HIGHS WILL APPROACH 70F...WITH HIGHS IN THE UPPER 50S/NEAR 60F THROUGH THE REMAINING PERIODS AFTER A WEAK COLD FRONT MOVES THROUGH THE REGION WED NIGHT/THU. OVERNIGHT LOWS SHOULD BE IN THE LOW TO MID 30S EACH NIGHT...WHICH IS IS STILL ABOUT 10F ABOVE NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1000 PM MST SAT NOV 17 2012 RESTRICTED VISIBILITIES ARE POSSIBLE AT KGLD AND EXPECTED AT KMCK AFTER 10Z OR SO THROUGH 15Z AS LOW LEVEL MOISTURE INCREASES AHEAD OF A SFC TROUGH WHICH BY 12Z WILL BE ALONG THE CO/KS BORDER. THIS TROUGH WILL SLOWLY MOVE EAST THROUGH THE DAY SUNDAY WITH W/NW WINDS BEHIND IT AND SOUTHERLY WINDS AHEAD OF IT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...MENTZER LONG TERM...DR AVIATION...99
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1047 PM MST SAT NOV 17 2012 .AVIATION... 06Z TAF CYCLE MID/HIGH LEVEL MOISTURE BOWING NORTHWARD OVER SOUTHERN AND CENTRAL NEW MEXICO...WHILE TOP DOWN MOISTENING TO CONTINUE...MAINLY EMBEDDED SCATTERED LIGHT SHOWERS WILL RESULT...WHICH MAY OBSCURE HIGHER TERRAIN FAVORING AREAS SOUTH OF HIGHWAY 60 NEXT 12 HOURS. IN ADDITION...DISTURBANCE PASSING THROUGH GREAT BASIN AND CENTRAL ROCKIES MAY RESULT IN ISOLD -RASN OR EVEN A SHORT LIVED THUNDERSTORM NEAR THE FOUR CORNERS AND THE NORTHWEST MTS AND MAY RESULT IN BRIEF MT OBSCURATIONS THRU 12Z SUNDAY. 00Z NAM12 AND LATEST RUC INDICATE SOME LOW/MID LEVEL MOISTURE MAY MAKE A RUN UP THE RGV POSSIBLY REACHING KABQ BY 12Z SUNDAY...THEREFORE MORE WIDESPREAD MT OBSCURATION POSSIBLE BUT CIGS MAY REMAIN VFR. && .DISCUSSION...TWO OPPORTUNITIES FOR PRECIPITATION THROUGH NEXT WEEK...THE FIRST ONE THROUGH THE REMAINDER OF THIS WEEKEND AND THE SECOND ONE WED AND WED NIGHT. OTHERWISE DRY WEATHER TO CONTINUE WITH ONLY MINOR DAY TO DAY AND NIGHT TO NIGHT FLUCTUATIONS IN TEMPERATURES. HIGH TEMPERATURES GENERALLY ABOVE NORMAL. NO STRONG WINDS ARE EXPECTED WITH MODERATE BREEZES IN THE E SUN AND WED. SHORT WAVE APPROACHING BAJA CA AND ANOTHER ONE OVER THE W COAST WILL MOVE NE TON AND SUN. ENOUGH LOWER LEVEL MOISTURE SHOULD GET DRAWN N INTO NM TO PRODUCE ISOLATED TO SCATTERED RAIN AND HIGHER ELEVATION SNOW SHOWERS TON INTO SUN...EXCEPT IN THE NE. DEWPOINTS CLIMBING INTO THE 20S AND 30S OVER THE SW ZONES WITH 30S AND 40S DEWPOINTS ALREADY ACROSS THE EASTERN PLAINS. DRYING TREND FOR LATE SUN INTO MON WITH A CHILLY NIGHT SUN NIGHT BUT A NICE MON PM WITH ABOVE NORMAL TEMPS AND PLENTY OF SUNSHINE. A WEAK BACK DOOR FRONT WILL SLOWLY PRESS S ACROSS THE EASTERN PLAINS MON BUT HAVE LITTLE IMPACT ON THE SENSIBLE WEATHER. A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE STATE MON NIGHT THEN SHIFT E TUE. IT WILL BE ANOTHER MILD DAY TUE WITH ABOVE NORMAL TEMPERATURES. MODELS REMAIN CONSISTENT IN BRINGING A LOW FROM OFF BAJA CA TUE TO SOUTHERN NM WED. THEY VARY ON THE EXTENT OF QPF...WITH THE EUROPEAN THE WETTEST FOLLOWED BY THE GFS THEN A MOSTLY DRY CANADIAN MODEL. WILL CONTINUE WITH LOW CHANCES OF RAIN SHOWERS OVER THE SC AND SE ZONES WED AND WED NIGHT. THANKSGIVING DAY AND BLACK FRIDAY LOOKING MIGHTY FINE WITH DRY CONDITIONS...LIGHT WINDS AND ABOVE NORMAL DAYTIME TEMPERATURES. CHJ && .FIRE WEATHER... ABOVE NORMAL TEMPERATURES EXPECTED FOR THE NEXT 7 DAYS WITH HUMIDITIES GENERALLY ABOVE CRITICAL THRESHOLDS. AN UPPER TROUGH WILL BRING SMALL PRECIPITATION CHANCES LATE THIS AFTERNOON THROUGH SUNDAY...AS WELL AS BREEZY CONDITIONS ACROSS THE PLAINS SUNDAY AFTERNOON. A BEAUTIFUL BAROCLINIC LEAF CLOUD MASS IS EVIDENT ON SATELLITE IMAGERY THIS AFTERNOON ASSOCIATED WITH AN OTHERWISE WEAK UPPER LEVEL TROUGH THAT WILL CROSS NEW MEXICO LATE THIS AFTERNOON THROUGH SUNDAY. THE SYSTEM SHOULD PRODUCE MAINLY ISOLATED AND LIGHT RAIN AND SNOW SHOWERS OVER CENTRAL...WESTERN AND SOUTHERN AREAS AS IT CROSSES. A FEW POCKETS OF WETTING PRECIPITATION WILL BE POSSIBLE ON THE WEST SLOPES OF THE SAN JUANS AND ACROSS THE SOUTHERN TIER OF NEW MEXICOS MOUNTAINS. WINDS ALOFT WILL ALSO STRENGTHEN WITH THE PASSING WEATHER SYSTEM...AND A LEE TROUGH IN THE EAST WILL CAUSE WEST AND SOUTHWEST WINDS TO BECOME BREEZY THERE SUNDAY AFTERNOON. IN THE WAKE OF THE WEATHER SYSTEM...A WEAK COLD FRONT WILL SAG SOUTHWARD THROUGH THE STATE MONDAY. AFTER HIGH TEMPERATURES A FEW TO 14 DEGREES ABOVE NORMAL THIS WEEKEND...HIGHS WILL TREND DOWNWARD A FEW DEGREES MONDAY AND ESPECIALLY TUESDAY. NONETHELESS...READINGS WILL REMAIN 4 TO 11 DEGREES ABOVE NORMAL ON TUESDAY...BEFORE WARMING SLIGHTLY WEDNESDAY. THE GFS AND ECMWF CONTINUE TO AGREE ON A WEAK UPPER LEVEL TROUGH TO EJECT FROM THE BAJA ACROSS NORTHERN MEXICO AND SOUTHERN NEW MEXICO TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. AHEAD OF THE SYSTEM A MOIST LOW LEVEL RETURN FLOW OUT OF THE SOUTHEAST SHOULD ENHANCE MOISTURE ALONG AND EAST OF THE CENTRAL MOUNTAINS. THE SYSTEM MAY FIND ENOUGH MOISTURE FOR A SLIGHT CHANCE OF RAIN SHOWERS IN SOUTHERN AND EASTERN NM...AND SOME OF THESE SHOWERS MAY EXTEND AS FAR NORTH AS THE MANZANO AND GALLINAS MOUNTAINS AND SOUTHERN PARTS OF THE EAST CENTRAL PLAINS. THE LOW LEVEL MOISTURE TAP WITH THE SYSTEM WILL PROBABLY BE TOO SHALLOW FOR MORE THAN SPOTTY WETTING PRECIPITATION. ANOTHER WEAK COLD FRONT WILL SAG SOUTHWARD THROUGH THE FORECAST AREA ON THURSDAY IN THE WAKE OF THE PASSING WAVE... CAUSING TEMPERATURES TO TREND SLIGHTLY COOLER THURSDAY AND FRIDAY. AFTER GOOD TO EXCELLENT VENTILATION IN MOST LOCATIONS OVER THE WEEKEND...POOR VENTILATION WILL SPREAD ACROSS CENTRAL AND WESTERN PARTS OF THE FORECAST AREA FROM THE WEST DURING THE FIRST HALF OF THE COMING WORK WEEK. DURING THE LATTER HALF OF THE WEEK THE POOR VENTILATION MAY BE COME EVEN MORE WIDESPREAD...EXPANDING TO INCLUDE THE EASTERN PLAINS BY FRIDAY. 44 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
247 AM EST SUN NOV 18 2012 .SYNOPSIS... THROUGH EARLY NEXT WEEK...STRONG HIGH PRESSURE WILL EXTEND ACROSS MUCH OF THE EASTERN US...WHILE A WEAK LOW PRESSURE SYSTEM WILL MEANDER OFF THE SOUTHEAST COAST. && .NEAR TERM /THROUGH SUNDAY NIGHT/... AS OF 930 PM SATURDAY... REST OF TONIGHT: COMPLEX PATTERN ACROSS THE SOUTHEAST AND MIDATLANTIC THIS EVENING... AND THE MAIN FORECAST CONCERN REMAINS THE CHANCE FOR RAIN OVERNIGHT. SURFACE HIGH PRESSURE REMAINS QUITE STRONG (OVER 1038 MB) CENTERED OVER THE ST LAWRENCE VALLEY AND EXTENDING SOUTHWARD THROUGH NC... WHILE A STRENGTHENING LOW LEVEL FRONTAL ZONE AND DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST IS EXPECTED TO GENERATE A TIGHTENING MSLP GRADIENT OVERNIGHT... ESPECIALLY OVER THE SRN AND ERN CWA. CONVECTION WAS WIDESPREAD JUST OFF THE CAROLINA COAST THIS AFTERNOON... AND WHILE THE INTENSITY OF THIS RAIN HAS DECREASED... IT REMAINS IN PLACE JUST OFF THE SC AND SRN NC COAST. THE 12Z 4-KM WRF-ARW AND WRF-NMM DID A SUBPAR JOB IN DEPICTING THIS RAIN... ALTHOUGH THE 18Z LOCAL WRF-ARW DID BETTER AND IS SIMILAR TO THE LATEST HRRR OUTPUT... WHICH SHOWS THE BULK OF THE RAIN SHIELD HOLDING OVER AND JUST OFF THE SC COAST WITH JUST PATCHY RAIN SPREADING INTO OUR FAR SOUTHEAST COUNTIES OVERNIGHT. THIS ALSO APPEARS IN LINE WITH THE LATEST SREF PROBABILITIES OF MEASURABLE RAIN... WHICH KEEPS CHANCES UNDER 30 PERCENT IN THE SOUTHEAST TONIGHT. BASED ON THIS AND MODEL AGREEMENT ON ACCELERATING LOW LEVEL MOISTURE TRANSPORT TONIGHT AND THE PACE AT WHICH THE LOWER STRATUS AND SMALLER DEW POINT DEPRESSION AIR IS SPREADING WESTWARD INTO SOUTHEAST NC... WILL HOLD ONTO A SLIGHT CHANCE OF RAIN TONIGHT IN THIS AREA. FORECAST SOUNDINGS DEPICT A FAIRLY DEEP (3000-4000 FT THICK) SURFACE-BASED STABLE LAYER... BUT CLOSE EXAMINATION REVEALS A VERY SHALLOW (FEW HUNDRED FEET) SLIGHTLY MIXED LAYER RIGHT AT THE SURFACE... REASONABLE CONSIDERING HOW THE WINDS THROUGHOUT THE LOWEST FEW THOUSAND FEET WILL BE STRENGTHENING AT ONCE. WILL KEEP WINDS UP OVERNIGHT WITH PERIODIC GUSTS. THE LOW LEVEL STIRRING WILL HOLD TEMPS UP... AND EXPECT LOWS OF 38-48. -GIH SUNDAY AND SUNDAY NIGHT...THE MID LEVEL ANTI-CYCLONE OFF THE SOUTHERN NEW ENGLAND COAST AND THE NE FL/SRN GA COAST WILL MAINTAIN A DEEP ELY FLOW INTO CENTRAL NC WITH SPEED CONFLUENCE NOTED OVER THE REGION DURING THE AFTERNOON-EARLY EVENING HOURS. THE LIFT SUPPLIED BY THIS CONFLUENCE WILL GENERATE AREAS OF LIGHT RAIN...MAINLY ALONG THE I-95 CORRIDOR. FARTHER WEST...LIFT WEAKER TO NON-EXISTENT. THIS WILL LEAD TO PRECIP CHANCES RANGING FROM LIKELY IN THE EAST TO LOW END CHANCE-SLIGHT CHANCE IN THE FAR WEST LATE SUNDAY INTO SUNDAY NIGHT. EXPECT A NARROW DIURNAL TEMP RANGE SUNDAY SUNDAY NIGHT DUE TO CLOUDS AND PRECIP. MAX TEMPS LOW-MID 50S SUNDAY.MIN TEMPS SUNDAY NIGHT AROUND 40 NW TO UPPER 40S/NEAR 50 E-SE. -WSS && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... AS OF 245 AM SUNDAY... MONDAY NIGHT: SURFACE LOW OFF THE NC COAST CONTINUES TO MIGRATE SLOWLY TO THE NE WITH RIDGING OVER NC AND SURFACE HIGH OVER NEW ENGLAND. OFFSHORE LOW BECOMES MORE VERTICALLY STACKED WITH THE UPPER LEVEL LOW OFFSHORE AND RIDGING OVER NC. CENTRAL NC SHOULD REMAIN DRY OVERNIGHT...WITH THE BEST CHANCES FOR LINGERING PRECIP ALONG THE NC COAST. WINDS WILL BE STRONGEST FARTHER EAST...5 TO 10 KTS. LOWS EXPECTED IN THE MID 40S. TUESDAY THROUGH WEDNESDAY: SURFACE HIGH PRESSURE REMAINS IN PLACE AS AN UPPER LEVEL TROUGH MOVES IN FROM THE WEST...WITH A S/W AHEAD OF THE MAIN TROUGH AXIS. ALTHOUGH THERE IS STRONG VORTICITY AT THE UPPER LEVELS WITH THE TROUGH AXIS...SURFACE HIGH PRESSURE...WITH ITS ASSOCIATED STABILITY AND SUBSIDENCE IN THE LOWER LEVELS SHOULD KEEP THE CHANCES FOR PRECIP LOW. THERE IS STILL SOME DIFFERENCE BETWEEN THE MODELS WITH REGARD TO PRECIP GENERATION WITH THE INITIAL S/W...AS THE 12Z ECMWF GENERATES PRECIP WHILE THE 00Z GFS REMAINS DRY THROUGHOUT. AS SUCH...WILL KEEP SLIGHT CHANCE FOR RAIN TUESDAY AND TUESDAY NIGHT AND A DRY FORECAST FOR WEDNESDAY...WITH OVERCAST SKIES EXPECTED TUESDAY AND TUESDAY NIGHT. STRONGEST WINDS IN THE EAST WHERE THE PRESSURE GRADIENT BETWEEN THE SURFACE HIGH AND OFFSHORE LOW IS THE GREATEST. HIGHS NEAR NORMAL...IN THE UPPER 50S TO LOW 60S TUESDAY AND WEDNESDAY WITH LOWS TUESDAY NIGHT IN THE LOW TO MID 40S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... AS OF 245 AM SUNDAY... SKIES WILL START CLEARING WEDNESDAY AFTERNOON AS THE UPPER LEVEL TROUGH MOVES OFFSHORE. AS THE TROUGH MOVES OFFSHORE THE SURFACE LOW OFF THE NC COAST WILL STRENGTHEN. THE LOW SHOULD BE FAR ENOUGH OFFSHORE TO KEEP PRECIP OUT OF THE AREA. WITH THE RIDGE BUILDING INTO THE AREA AT THE SURFACE AND ALOFT THURSDAY MORNING AND REMAINING OVER CENTRAL NC THROUGH FRIDAY...WILL KEEP THE FORECAST DRY THROUGH THAT PERIOD. HIGH TEMPS WILL BE IN THE MID 60S THURSDAY AND FRIDAY WITH LOWS WEDNESDAY...THURSDAY...AND FRIDAY NIGHTS RANGING FROM THE MID 30S TO LOW 40S. THERE ARE LARGE DIFFERENCES BETWEEN THE 12Z ECMWF AND 00Z GFS FRIDAY AND SATURDAY WITH REGARD TO WHETHER AN UPPER LEVEL LOW AND ASSOCIATED TROUGH (ECMWF) WILL DEVELOP AND DIG INTO THE AREA FRIDAY NIGHT OR WHETHER THE PATTERN ALOFT WILL REMAIN MORE ZONAL FRIDAY NIGHT...WITH A WEAKER TROUGH DEVELOPING TO THE WEST LATE SATURDAY (GFS). PRECIP CHANCES WILL DEPEND UPON THE TIMING AND STRENGTH OF THIS SYSTEM. WITH THE GREAT DEAL OF UNCERTAINTY IN THE MODELS...CONFIDENCE IN THE PRECIP FORECAST FRIDAY AND SATURDAY IS LOW...BUT FOR NOW WILL KEEP IT DRY. HIGHS ON SATURDAY WILL ALSO BE IMPACTED IF PRECIP DOES DEVELOP...BUT STAYING CONSISTENT WITH THE DRY FORECAST...ANTICIPATE HIGHS IN THE UPPER 50S TO LOW 60S. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 125 AM SUNDAY... THE PRESSURE GRADIENT BETWEEN STRONG HIGH PRESSURE OVER THE NORTHEAST AND A FRONTAL ZONE AND DEVELOPING AREA OF LOW PRESSURE OFF THE SOUTHEAST US COAST WILL PRODUCE STRONG NORTHEASTERLY LOW LEVEL FLOW THAT WILL RESULT IN BOTH THE EXPANSION OF 1000-2000 FT (MVFR) CEILINGS THIS MORNING AND BREEZY AND GUSTY NE SURFACE WINDS THROUGH THE TAF PERIOD. THE CEILINGS MAY BRIEFLY LOWER TO IFR RANGE...JUST BELOW 1000 FT...FOR A FEW HOURS THIS MORNING AT KRWI/KRDU...BUT PREDOMINATELY MVFR CEILINGS ARE EXPECTED. THE OFFSHORE AREA OF LOW PRESSURE WILL ALSO RESULT IN PATCHY LIGHT RAIN TODAY AND TONIGHT MAINLY AT KFAY/KRWI/KRDU...AS IT MEANDERS OFF THE SOUTHEAST COAST. LOOKING AHEAD: WHILE THE WINDS WILL GRADUALLY LESSEN BY MON...OWING TO A STEADY WEAKENING OF THE SURFACE HIGH OVER THE NORTHEAST AND CONSEQUENT RELAXATION OF THE MSL PRESSURE GRADIENT...THE WEAKENED NORTHEASTERLY FLOW WILL REMAIN MOIST AND MAINTAIN A HIGH PROBABILITY OF MVFR RANGE CEILINGS THROUGH EARLY TUE. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MWS NEAR TERM...HARTFIELD/WSS SHORT TERM...KC LONG TERM...KC AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
130 AM EST SUN NOV 18 2012 .SYNOPSIS... THROUGH EARLY NEXT WEEK...STRONG HIGH PRESSURE WILL EXTEND ACROSS MUCH OF THE EASTERN US...WHILE A WEAK LOW PRESSURE SYSTEM WILL MEANDER OFF THE SOUTHEAST COAST. && .NEAR TERM /THROUGH SUNDAY NIGHT/... AS OF 930 PM SATURDAY... REST OF TONIGHT: COMPLEX PATTERN ACROSS THE SOUTHEAST AND MIDATLANTIC THIS EVENING... AND THE MAIN FORECAST CONCERN REMAINS THE CHANCE FOR RAIN OVERNIGHT. SURFACE HIGH PRESSURE REMAINS QUITE STRONG (OVER 1038 MB) CENTERED OVER THE ST LAWRENCE VALLEY AND EXTENDING SOUTHWARD THROUGH NC... WHILE A STRENGTHENING LOW LEVEL FRONTAL ZONE AND DEVELOPING LOW PRESSURE OFF THE SOUTHEAST COAST IS EXPECTED TO GENERATE A TIGHTENING MSLP GRADIENT OVERNIGHT... ESPECIALLY OVER THE SRN AND ERN CWA. CONVECTION WAS WIDESPREAD JUST OFF THE CAROLINA COAST THIS AFTERNOON... AND WHILE THE INTENSITY OF THIS RAIN HAS DECREASED... IT REMAINS IN PLACE JUST OFF THE SC AND SRN NC COAST. THE 12Z 4-KM WRF-ARW AND WRF-NMM DID A SUBPAR JOB IN DEPICTING THIS RAIN... ALTHOUGH THE 18Z LOCAL WRF-ARW DID BETTER AND IS SIMILAR TO THE LATEST HRRR OUTPUT... WHICH SHOWS THE BULK OF THE RAIN SHIELD HOLDING OVER AND JUST OFF THE SC COAST WITH JUST PATCHY RAIN SPREADING INTO OUR FAR SOUTHEAST COUNTIES OVERNIGHT. THIS ALSO APPEARS IN LINE WITH THE LATEST SREF PROBABILITIES OF MEASURABLE RAIN... WHICH KEEPS CHANCES UNDER 30 PERCENT IN THE SOUTHEAST TONIGHT. BASED ON THIS AND MODEL AGREEMENT ON ACCELERATING LOW LEVEL MOISTURE TRANSPORT TONIGHT AND THE PACE AT WHICH THE LOWER STRATUS AND SMALLER DEW POINT DEPRESSION AIR IS SPREADING WESTWARD INTO SOUTHEAST NC... WILL HOLD ONTO A SLIGHT CHANCE OF RAIN TONIGHT IN THIS AREA. FORECAST SOUNDINGS DEPICT A FAIRLY DEEP (3000-4000 FT THICK) SURFACE-BASED STABLE LAYER... BUT CLOSE EXAMINATION REVEALS A VERY SHALLOW (FEW HUNDRED FEET) SLIGHTLY MIXED LAYER RIGHT AT THE SURFACE... REASONABLE CONSIDERING HOW THE WINDS THROUGHOUT THE LOWEST FEW THOUSAND FEET WILL BE STRENGTHENING AT ONCE. WILL KEEP WINDS UP OVERNIGHT WITH PERIODIC GUSTS. THE LOW LEVEL STIRRING WILL HOLD TEMPS UP... AND EXPECT LOWS OF 38-48. -GIH SUNDAY AND SUNDAY NIGHT...THE MID LEVEL ANTI-CYCLONE OFF THE SOUTHERN NEW ENGLAND COAST AND THE NE FL/SRN GA COAST WILL MAINTAIN A DEEP ELY FLOW INTO CENTRAL NC WITH SPEED CONFLUENCE NOTED OVER THE REGION DURING THE AFTERNOON-EARLY EVENING HOURS. THE LIFT SUPPLIED BY THIS CONFLUENCE WILL GENERATE AREAS OF LIGHT RAIN...MAINLY ALONG THE I-95 CORRIDOR. FARTHER WEST...LIFT WEAKER TO NON-EXISTENT. THIS WILL LEAD TO PRECIP CHANCES RANGING FROM LIKELY IN THE EAST TO LOW END CHANCE-SLIGHT CHANCE IN THE FAR WEST LATE SUNDAY INTO SUNDAY NIGHT. EXPECT A NARROW DIURNAL TEMP RANGE SUNDAY SUNDAY NIGHT DUE TO CLOUDS AND PRECIP. MAX TEMPS LOW-MID 50S SUNDAY.MIN TEMPS SUNDAY NIGHT AROUND 40 NW TO UPPER 40S/NEAR 50 E-SE. -WSS && .SHORT TERM /MONDAY AND MONDAY NIGHT/... AS OF 310 PM SATURDAY... MONDAY AND MONDAY NIGHT...WHILE MID LEVEL ANTI-CYCLONE WILL REMAIN NEARLY STATIONARY OFF THE NORTHERN MID ATLANTIC COAST...THE AREA OF LOW PRESSURE OFF THE NE FL COAST WILL LIFT TO THE ENE. THIS MOVEMENT OF THE LOW WILL CAUSE THE MID LEVEL FLOW OVER CENTRAL NC TO WEAKEN AND BECOME MORE NELY. THUS...EXPECT RAIN CHANCES TO DWINDLE MONDAY WITH A SLIGHT CHANCE POP CONFINED TO THE EASTERN HALF BY AFTERNOON....AND LITTLE IF ANY RAIN EXPECTED MONDAY NIGHT. MODEL GUIDANCE DIFFERS AS TO THE AMOUNT OF DECREASING CLOUDINESS TO OCCUR WHICH LEADS TO DISCREPANCIES IN THE TEMP GUIDANCE MONDAY. LATEST NAM MORE EMPHATIC WITH ITS CLEARING TREND WHICH TRANSLATES TO WARMER AFTERNOON TEMPS. THE 12Z ECMWF WEAKEN OFFERS A SCENARIO SOMEWHAT BUT NOT AS EMPHATIC WITH THE AMOUNT OF DRYING. GFS MAINTAINS A SATURATED AIR MASS THROUGH THE PERIOD. PLACED A BIT MORE EMPHASIS TOT EH GFS AS POTENTIAL EXIST FOR MOISTURE TO BE TRAPPED BELOW MID LEVEL SUBSIDENCE INVERSION. THUS WILL FAVOR HIGH TEMPS MONDAY TOWARD THE COOLER GFS MOS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 310 PM SATURDAY... BRIEF S/W RIDING ALOFT AT THE START OF THE MEDIUM RANGE PERIOD IS EXPECTED TO QUICKLY SHIFT TO THE EAST OF THE AREA ON TUESDAY AS A PAIR OF MID/UPPER LEVEL DISTURBANCES USHER IN A RETURN TO POSSIBLE UNSETTLE WEATHER. HOWEVER... AT THE SURFACE/LOW LEVELS OF THE ATMOSPHERE EXPECT A GENERALLY NORTHERLY FLOW WILL CONTINUE... WITH THE AFOREMENTIONED SURFACE LOW PRESSURE EXPECTED TO REMAIN OFFSHORE OR SLOWLY LIFT NORTH OR NORTHEASTWARD. MODELS ARE CONTINUING TO STRUGGLE THOUGH WRT POSSIBLE LIGHT RAIN FOR TUESDAY INTO TUESDAY NIGHT. THE DIFFERENCES APPEAR TO BE TIED TO THE STRENGTH IN THE MID/UPPER LEVEL RIDGING AND APPROACHING NEXT SET OF IMPULSES ALOFT. FOR NOW WILL TREND THE FORECAST TO THE DRIER SIDE OF GUIDANCE (CLOSER TO THE ECMWF AND NAM). FOR NOW WILL LOWER POPS TO SLIGHT CHANCE AREAWIDE. HOWEVER... STILL EXPECT SKIES WILL BE AT LEAST MOSTLY CLOUDY WHICH WILL STILL HELP SUPPRESS HIGH TEMPS DESPITE LOW LEVEL THICKNESS VALUES AROUND NORMAL. WILL GO WITH HIGH TEMPS IN THE UPPER 50S TO AROUND 60... A BIT BELOW NORMAL. HOWEVER... IF THE RAIN DOES MATERIALIZE EXPECTED TEMPS WOULD BE A GOOD 5 TO 10 DEGREES COOLER AT LEAST THAN CURRENT FORECAST. LOW TUESDAY NIGHT/WEDNESDAY MORNING ARE EXPECTED TO BE IN THE LOWER TO MID 40S... WITH SKIES BEGINNING TO CLEAR AT BIT (MORE SO WEST) AS THE FIRST DISTURBANCE BEGINS TO PUSH TO THE EAST OF THE AREA. MID/UPPER LEVEL TROUGH AXIS IS EXPECTED TO AMPLIFY ACROSS THE AREA AGAIN ON WEDNESDAY AS A SECOND S/W TROUGH ROTATES THROUGH THE AREA ON WEDNESDAY/WEDNESDAY NIGHT. HOWEVER... DESPITE THE DEEPENING TROUGH... BEST LIFT AND MOISTURE SHOULD REMAIN TO THE SOUTH OF THE AREA. THUS... WITH AFTERNOON LOW LEVEL THICKNESS VALUES AROUND NORMAL AND SKIES BECOMING PARTLY SUNNY LATE IN THE DAY EXPECT HIGH TEMPS TO BE IN THE UPPER 50S TO LOWER 60S. LOWS WITH CLEARING SKIES ON THURSDAY MORNING ARE EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S. THURSDAY THROUGH SATURDAY: RIDGING ALOFT IS EXPECTED TO BUILD ACROSS THE AREA DURING THIS TIMEFRAME... WHILE A NORTHERN STREAM SYSTEM IS EXPECTED TO MOVE ACROSS THE NORTHERN PORTION OF THE COUNTRY. AT THE SURFACE EXPECT HIGH PRESSURE WILL REMAIN ACROSS THE AREA THROUGH AT LEAST FRIDAY MORNING/AFTERNOON... BEFORE A TRAILING DRY COLD FRONT ASSOCIATED WITH THE NORTHERN STREAM SYSTEM IS EXPECTED TO MOVE THROUGH THE AREA LATE FRIDAY INTO FRIDAY NIGHT. HIGH PRESSURE IS EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT ON SATURDAY. EXPECT ABOVE NORMAL TEMPS THURSDAY/FRIDAY... WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS ON SATURDAY. EXPECT HIGH TEMPS IN THE 60S THURSDAY/FRIDAY TO UPPER 50S TO AROUND 60 NEXT SATURDAY. LOWS IN THE UPPER 30S TO LOWER 40S... WITH POSSIBLE MID 30S IN THE USUAL RURAL COOL/COLDER AREAS. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 125 AM SUNDAY... THE PRESSURE GRADIENT BETWEEN STRONG HIGH PRESSURE OVER THE NORTHEAST AND A FRONTAL ZONE AND DEVELOPING AREA OF LOW PRESSURE OFF THE SOUTHEAST US COAST WILL PRODUCE STRONG NORTHEASTERLY LOW LEVEL FLOW THAT WILL RESULT IN BOTH THE EXPANSION OF 1000-2000 FT (MVFR) CEILINGS THIS MORNING AND BREEZY AND GUSTY NE SURFACE WINDS THROUGH THE TAF PERIOD. THE CEILINGS MAY BRIEFLY LOWER TO IFR RANGE...JUST BELOW 1000 FT...FOR A FEW HOURS THIS MORNING AT KRWI/KRDU...BUT PREDOMINATELY MVFR CEILINGS ARE EXPECTED. THE OFFSHORE AREA OF LOW PRESSURE WILL ALSO RESULT IN PATCHY LIGHT RAIN TODAY AND TONIGHT MAINLY AT KFAY/KRWI/KRDU...AS IT MEANDERS OFF THE SOUTHEAST COAST. LOOKING AHEAD: WHILE THE WINDS WILL GRADUALLY LESSEN BY MON...OWING TO A STEADY WEAKENING OF THE SURFACE HIGH OVER THE NORTHEAST AND CONSEQUENT RELAXATION OF THE MSL PRESSURE GRADIENT...THE WEAKENED NORTHEASTERLY FLOW WILL REMAIN MOIST AND MAINTAIN A HIGH PROBABILITY OF MVFR RANGE CEILINGS THROUGH EARLY TUE. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MWS NEAR TERM...HARTFIELD/WSS SHORT TERM...WSS LONG TERM...BSD AVIATION...MWS
AREA FORECAST DISCUSSION
NWS SPOKANE WA
956 PM PST Sat Nov 17 2012 .SYNOPSIS... Through next week expect a progressive and wet weather pattern to return with periods of mountain snow and valley rain this weekend and through next week. Higher snow levels Sunday Night through Tuesday morning will combine with the heaviest expected precipitation in this forecast cycle to produce rises on the areas small stream or creeks...especially for North Idaho. Windy conditions will develop over portions of the Inland Northwest on Monday. && .DISCUSSION... ...Areas of heavy rain...mountain snow...along with windy conditions early next week.... Update...Radar imagery as of 945 pm indicated a large area of rain associated with a cold front from Republic to Moses Lake eastward to near the Washington/Idaho Border. The GFS/NAM/HRRR shows this area of rain moving east through tonight with drier air and downslope flow off the Cascades bringing a drying trend from west to east. The HRRR which has a good handle on this area of rain shows the back edge of the rain passing through Moses Lake around 10 pm, Spokane 1 am, and Sandpoint 3 am. This matches the trends from the NAM well so opted to update the forecast tonight to show these trends in the NDFD grids. However some showers may linger over the mountains of NE Washington and N Idaho Sunday morning after the front passes due to the 850-700mb layer remaining nearly saturated along with upslope flow. No big changes noted on the 00z GFS run concerning the active period expected for early next week with heavy mountain snow along the East Slopes of the Cascades and Northern Mountains, windy weather across portions of the area, along with heavy rain for much of the Inland Northwest. See previous forecast discussion and latest Weather Stories on our home page for more information. JW && .AVIATION... 06Z TAFs: Rain will persist through 08-11z over Eastern Washington and North Idaho as a cold front tracks through the area. Expect lowering cigs and vis into MVFR category with rain this evening. Moist upslope flow over the Spokane/Coeur d`Alene taf sites behind the front is expected to lower cigs into the IFR category through at least the early morning hours on Sunday. We will see a break in the precipitation Sunday morning with another round of rain crossing the Cascades around 00z Monday as a warm front moves in. Good mixing potential on Sunday afternoon may result in gusts up to 20-25 kts for the KGEG, KSFF, KCOE, KPUW and KMWH taf sites. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 37 45 38 42 40 46 / 100 50 100 100 100 80 Coeur d`Alene 37 45 36 42 40 46 / 100 50 90 100 100 80 Pullman 37 47 38 44 42 49 / 100 30 80 70 100 80 Lewiston 40 53 42 50 45 53 / 90 20 60 70 90 70 Colville 37 43 38 41 38 47 / 100 50 100 100 100 80 Sandpoint 37 44 35 41 38 44 / 100 80 90 100 100 100 Kellogg 37 41 34 39 39 44 / 100 80 60 100 100 100 Moses Lake 36 47 39 47 40 49 / 70 10 60 50 70 60 Wenatchee 37 45 38 44 39 47 / 40 20 90 50 70 60 Omak 35 42 37 42 39 45 / 100 30 100 100 70 60 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...High Wind Watch from late Sunday night through Monday evening for Coeur d`Alene Area-Idaho Palouse. Winter Storm Watch from Sunday evening through late Monday night for Northern Panhandle. WA...Winter Storm Watch from Sunday afternoon through Monday evening for East Slopes Northern Cascades. High Wind Watch from late Sunday night through Monday evening for Lower Garfield and Asotin Counties-Moses Lake Area- Northeast Blue Mountains-Northeast Mountains-Okanogan Highlands-Spokane Area-Upper Columbia Basin-Washington Palouse. Winter Storm Watch from Sunday evening through late Monday night for Northeast Mountains-Okanogan Highlands. && $$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
828 PM PST Sat Nov 17 2012 .SYNOPSIS... Through next week expect a progressive and wet weather pattern to return with periods of mountain snow and valley rain this weekend and through next week. Higher snow levels Sunday Night through Tuesday morning will combine with the heaviest expected precipitation in this forecast cycle to produce rises on the areas small stream or creeks...especially for North Idaho. Windy conditions will develop over portions of the Inland Northwest on Monday. && .DISCUSSION... ...Areas of heavy rain...mountain snow...along with windy conditions early next week.... Update...Radar imagery as of 8 pm indicated a large area of rain associated with a cold front from Omak to Moses Lake eastward to near the Washington/Idaho Border. The GFS/NAM/HRRR shows this area of rain moving east through tonight with drier air and downslope flow off the Cascades bringing a drying trend from west to east. The HRRR which has a good handle on this area of rain shows the back edge of the rain passing through Moses Lake around 10 pm, Spokane 1 am, and Sandpoint 3 am. This matches the trends from the NAM well so opted to update the forecast tonight to show these trends in the NDFD grids. However some showers may linger over the mountains of NE Washington and N Idaho Sunday morning after the front passes due to the 850-700mb layer remaining nearly saturated along with upslope flow. No big changes noted on the 00z GFS run concerning the active period expected for early next week with heavy mountain snow along the East Slopes of the Cascades and Northern Mountains, windy weather across portions of the area, along with heavy rain for much of the Inland Northwest. See previous forecast discussion and latest Weather Stories on our home page for more information. JW && .AVIATION... 00Z TAFs: A cold front is pushing into coastal Washington this evening. Moist isentropic accent ahead of the front will result in light rain at all taf sites this evening. Rainfall will diminish from west to east late this evening into tonight as the front pushes east of the region. Expect lowering cigs and vis into MVFR category with rain this evening. Moist upslope flow over the Spokane/Coeur d`Alene taf sites behind the front is expected to lower cigs into the IFR category through at least the early morning hours on Sunday. We will see a break in the precipitation Sunday morning with rain returning Sunday afternoon as a warm front pushes in. Good mixing potential on Sunday afternoon may result in a gusts up to 20-25 kts for the KGEG, KSFF, KCOE, KPUW and KMWH taf sites. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 37 45 38 42 40 46 / 100 50 100 100 100 80 Coeur d`Alene 37 45 36 42 40 46 / 100 50 90 100 100 80 Pullman 37 47 38 44 42 49 / 100 30 80 70 100 80 Lewiston 40 53 42 50 45 53 / 90 20 60 70 90 70 Colville 37 43 38 41 38 47 / 100 50 100 100 100 80 Sandpoint 37 44 35 41 38 44 / 100 80 90 100 100 100 Kellogg 37 41 34 39 39 44 / 100 80 60 100 100 100 Moses Lake 36 47 39 47 40 49 / 70 10 60 50 70 60 Wenatchee 37 45 38 44 39 47 / 40 20 90 50 70 60 Omak 35 42 37 42 39 45 / 100 30 100 100 70 60 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...High Wind Watch from late Sunday night through Monday evening for Coeur d`Alene Area-Idaho Palouse. Winter Storm Watch from Sunday evening through late Monday night for Northern Panhandle. WA...Winter Storm Watch from Sunday afternoon through Monday evening for East Slopes Northern Cascades. High Wind Watch from late Sunday night through Monday evening for Lower Garfield and Asotin Counties-Moses Lake Area- Northeast Blue Mountains-Northeast Mountains-Okanogan Highlands-Spokane Area-Upper Columbia Basin-Washington Palouse. Winter Storm Watch from Sunday evening through late Monday night for Northeast Mountains-Okanogan Highlands. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
212 AM CST SUN NOV 18 2012 .SHORT TERM...THROUGH TUESDAY NIGHT 212 AM CST SUN NOV 18 2012 MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TONIGHT INTO MONDAY AS WELL AS TEMPERATURES THROUGHOUT. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP TROUGH FROM JUST OFF THE COAST OF BRITISH COLUMBIA INTO THE PACIFIC NORTHWEST...AND SOUTHWEST FLOW FROM THE DESERT SOUTHWEST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION. WITHIN THIS SOUTHWEST FLOW...SHORTWAVES OF NOTE ARE ALONG THE UTAH/COLORADO BORDER AND IN NORTHWEST MINNESOTA. DPVA AHEAD OF THIS LATTER SHORTWAVE COMBINED WITH 295-300K ISENTROPIC LIFT PRODUCED SHOWERS ACROSS NORTHEAST MINNESOTA. THE 295K ISENTROPIC LIFT ALSO EXTENDED SOUTHWEST FROM NORTHEAST MINNESOTA INTO CENTRAL IOWA...AND ALONG THIS ZONE IS A BAND OF STRATUS WITH CEILINGS BETWEEN 6000-9000 FT. THE BAND OF STRATUS ALSO SEPARATES MOIST AIR FROM VERY DRY AIR AT 850MB. FOR EXAMPLE...FROM 00Z SOUNDINGS...THE 850MB DEWPOINT AT DVN WAS -20C WHILE IT WAS -2C AT MPX AND 1C AT OAX. THE BROAD SOUTHWEST FLOW ALOFT HAS RESULTED IN A WARM ADVECTION PATTERN ACROSS THE UPPER MIDWEST. 850MB TEMPS WERE +6C AT MPX AND OAX AT 00Z. THE LOW LEVEL SOUTHERLY FLOW WAS FAIRLY STRONG WITH 925MB PROFILER AND VWP DATA SHOWING SPEEDS OF 35-45KT AROUND THE FORECAST AREA. THESE WINDS ARE HOLDING TEMPERATURES UP FROM THE MID 30S TO MID 40S...WARMEST IN SOUTHEAST MINNESOTA. TODAY AND TONIGHT...FOCUS IS ON THAT SHORTWAVE ALONG THE UTAH/COLORADO BORDER. GOOD MODEL AGREEMENT REMAINS ON THIS SHORTWAVE LIFTING UP THROUGH THE SOUTHWEST FLOW AND MOVING INTO WESTERN PORTIONS OF THE FORECAST AREA BY 12Z MONDAY. BRIEF RIDGING DEVELOPS OVER THE FORECAST AREA TODAY DOWNSTREAM OF THIS SHORTWAVE...WHICH SHOULD ACT TO CLEAR THE CLOUDS UP SOMEWHAT. WITH THE RELATIVELY SPEAKING WARM START...SUNSHINE AND 925MB TEMPS AROUND 6C WHICH ARE SIMILAR TO YESTERDAY...ANTICIPATING HIGHS TO BE FAIRLY SIMILAR TO A FEW DEGREES WARMER THAN YESTERDAY. FOR TONIGHT...THE 850MB MOISTURE STREAM CURRENTLY OVER WESTERN MINNESOTA AND IOWA WILL GET PUSHED EAST INTO THE FORECAST AREA BY THE SHORTWAVE. THE MAIN QUESTION IS IF DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE WILL BE STRONG ENOUGH TO ACT ON THIS MOISTURE AND PRODUCE PRECIPITATION. MID CLOUD DEVELOPMENT IS A CERTAINTY...GIVEN WHAT HAPPENED LAST EVENING ON THE LEADING EDGE OF THE 850MB MOISTURE STREAM. THE 18.00Z NAM/REGIONAL CANADIAN PAINT A DRY PICTURE AND EVEN THE GFS WHICH LOOKS TO HAVE A BIT TOO MUCH MOISTURE COMPARED TO ALL OTHER MODELS PRODUCES LITTLE IF ANY PRECIPITATION BEFORE 12Z. THE 17.12Z ECMWF MEANWHILE REMAINS MOST ROBUST WITH 0.1-0.2 OF AN INCH OVER NORTHEAST IOWA BETWEEN 06-12Z MONDAY. NEW 18.00Z ECMWF IS SLIGHTLY DRIER. SREF TRENDS HAVE SHOWN LESS MEMBERS PRODUCING 0.01 OF AN INCH OVER THE LAST 5 RUNS...DOWN FROM 40-50 PERCENT TO 10-30 PERCENT. AT THIS POINT...CANNOT SEE GOING WITH THE MORE ROBUST ECMWF SOLUTION AND HAVE KEPT CHANCES LOW IN THE 20-30 PERCENT RANGE...CENTERED IN THE 09-12Z PERIOD. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE BEING MAINTAINED...A SLIGHTLY WARMER NIGHT THAN TONIGHT IS ANTICIPATED. MONDAY AND MONDAY NIGHT...THE SHORTWAVE OVER WESTERN PORTIONS OF THE FORECAST AREA AT 12Z LOOKS TO MOVE THROUGH THE REST OF THE FORECAST AREA BY EARLY AFTERNOON...WHILE THE TAIL END OF THE DEEP TROUGHING IN THE PACIFIC NORTHWEST IS PROGGED TO DROP DOWN INTO THE FORECAST AREA AFTER MIDNIGHT MONDAY NIGHT. THIS LATTER SHORTWAVE WILL COME THROUGH DRY SINCE THE SHORTWAVE COMING THROUGH MONDAY MORNING ENDS UP SCOURING OUT A LOT OF THE MOISTURE. THUS ALL FOCUS IS ON THE MONDAY MORNING PERIOD. AGAIN HERE...MODELS ARE AT ODDS WITH FORCING AND MOISTURE AVAILABILITY. THE 18.00Z NAM/REGIONAL CANADIAN SAYS THERE IS TOO MUCH DRY AIR BELOW 800MB AND THE FORCING IS TOO WEAK ABOVE IT TO ALLOW FOR PRECIPITATION TO MAKE IT TO THE SURFACE. ON THE OTHER HAND...THE 18.00Z GFS AND 17.12Z/18.00Z ECMWF ARE MORE ROBUST IN BOTH ARENAS AND END UP PRODUCING LIGHT QPF ACROSS MUCH OF THE AREA. SREF TRENDS FOR THE FULL DAY MONDAY ARE ALSO SIMILAR TO 06-12Z MONDAY...SHOWING A DECLINE OF MEMBERS PRODUCING AT LEAST 0.01 OF AN INCH. IT USED TO BE UP AT 70-80 PERCENT BUT NOW IS DOWN TO 30-60 PERCENT. THUS...CONFIDENCE REMAINS TOO LOW TO ADJUST THE PREVIOUS FORECAST PRECIPITATION CHANCES OF 20-40 PERCENT. CERTAINLY IF ANY PRECIPITATION OCCURS...ANY RAIN LOOKS REALLY LIGHT. REGARDING CLOUD COVER...IT NOW APPEARS THAT THE SHORTWAVE ON MONDAY MORNING SHOULD HELP TO CLEAR THE CLOUDS OUT AS IT MOVES AWAY DURING THE AFTERNOON. THERE MAY BE AN INCREASE OF CIRRUS WITH THE SHORTWAVE COMING IN MONDAY NIGHT...BUT THATS ABOUT IT. NOTE THAT THERE IS CONCERN FOR A LOW CLOUD DECK BASED ON THE GFS/ECMWF 925MB RH PROGS...BUT THEY MAY BE TOO MOIST. FOR NOW TAKING A COMPROMISE APPROACH BY SPEEDING UP THE CLEARING SOME FROM THE PREVIOUS FORECAST. HAVING MORE CLOUDS MONDAY WILL HOLD THE TEMPERATURES DOWN A FEW DEGREES FROM HIGHS OVER THE WEEKEND. A COOLER NIGHT SEEMS LIKELY TOO FOR MONDAY NIGHT...ESPECIALLY IF THE CLEARING OCCURS. TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THAT SHORTWAVE DROPPING INTO THE FORECAST AREA TUESDAY MORNING...SOME FAIRLY STRONG RIDGING IS PROGGED TO BUILD INTO THE FORECAST AREA BY TUESDAY EVENING. ABOUT ALL THAT SHORTWAVE IS GOING TO DO IS PREVENT THE 850MB TEMP CLIMB...NOTED BY 850MB TEMPS AT 18Z TUESDAY OF 5-7C. ONCE THE RIDGING STARTS BUILDING IN...THESE TEMPS CLIMB...TOPPING OUT AT 8C EAST TO 11C WEST BY 12Z WEDNESDAY. WITH WHAT SHOULD BE PLENTY OF SUN...HIGHS SHOULD BE ABLE TO TOP OUT IN THE 50S AGAIN ON TUESDAY GIVEN THE AFOREMENTIONED 850MB TEMPS. INCREASING SOUTHERLY FLOW TUESDAY NIGHT IN THE WAKE OF HIGH PRESSURE THAT CROSSES THE AREA ON TUESDAY WILL HELP TO KEEP TEMPERATURES UP IN SOUTHEAST MINNESOTA. FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT 212 AM CST SUN NOV 18 2012 MAIN FOCUS CONTINUES TO BE ON A POTENT SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST WEDNESDAY MORNING. MODEL AGREEMENT HANDLING THIS POTENT TROUGH BEGINS TO DECLINE AS EARLY AS 12Z THURSDAY...WITH THE 18.00Z ECMWF/CANADIAN SHOWING A DIGGING NATURE TO IT INTO THE NORTHERN PLAINS. MEANWHILE...THE 18.00Z GFS TAKES A MORE PROGRESSIVE APPROACH AND SENDS IT UP INTO NORTHERN ONTARIO ON THURSDAY. BOTH THE GFS AND ECMWF HAVE COMPLETELY FLIPPED FROM PREVIOUS RUNS WITH THE HANDLING OF THIS POTENT TROUGH. THE 18.00Z ECMWF LOOKS MORE LIKE THE 17.00Z GFS WHILE THE 18.00Z GFS LOOKS MORE LIKE THE 16.12Z ECMWF. THIS HAS SIGNIFICANT IMPLICATIONS ON THE TEMPERATURE AND WIND FORECASTS...PRIMARILY FRIDAY AND BEYOND. WITH THE MORE DIGGING NATURE OF THE ECMWF/CANADIAN...THEY END UP CARVING OUT A DEEP TROUGH ACROSS THE WESTERN GREAT LAKES REGION FOR FRIDAY...THOUGH WITHIN THIS GROUP THE CANADIAN IS MORE PROGRESSIVE. WHICHEVER MODEL SCENARIO PLAYS OUT...IT APPEARS DRY WEATHER WOULD BE THE RULE WITH THE BEST JUXTAPOSITION OF FORCING AND MOISTURE EITHER NORTH OR SOUTHEAST OF THE AREA. GIVEN THE DIFFERENCES EARLY IN THE LONG TERM PERIOD...HARD TO SAY HOW THE WEEKEND WILL PLAY ITSELF OUT. NOTE THAT THE 18.00Z GFS ENSEMBLES HAVE A PRETTY GOOD SPREAD TOO WITH REGARDS TO THE POTENT TROUGH. THUS FOR NOW HAVE STAYED WITH A CONSENSUS APPROACH WHEN IT COMES TO THE WEEKEND...YIELDING COOLER AND A CONTINUATION OF DRY CONDITIONS. REGARDING TEMPERATURES...WEDNESDAY AND THANKSGIVING DAY STILL LOOK WELL ABOVE NORMAL...ESPECIALLY WEDNESDAY AS 925MB TEMPS CLIMB TO 10-12C FOR 18Z. MIXING TO 925MB YIELDS HIGHS FROM THE UPPER 50S TO MIDDLE 60S...THUS HAVE BOOSTED HIGHS A FEW DEGREES. RECORD HIGHS FOR WEDNESDAY ARE 72 AT LA CROSSE AND 69 AT ROCHESTER...STILL 5-10 DEGREES ABOVE THE GOING FORECAST. NOTE THAT 850MB TEMP STANDARDIZED ANOMALIES HAVE NOW JUMPED TO NEAR 2...SUPPORTING THE INCREASING IN HIGH TEMPERATURES. SOME COOLING IN 925MB TEMPS TAKES PLACE ON THANKSGIVING DAY AS A COLD FRONT MOVES INTO THE REGION. STILL...MOST LOCATIONS SHOULD TOP OUT AT LEAST IN THE MID TO UPPER 50S...MAYBE EVEN 60 AT SOME SOUTH OF I-90. RECORD HIGH FOR THURSDAY IS 59 AT LA CROSSE AND 65 AT ROCHESTER...THUS LA CROSSE MAY BE DOABLE TO BREAK. TEMPERATURES SHOULD RETURN CLOSER TO NORMAL FOR FRIDAY INTO THE WEEKEND IN THE WAKE OF THE COLD FRONT. IF THE 18.00Z ECMWF IS CORRECT...WE COULD EVEN BE BELOW NORMAL FOR THE WEEKEND. && .AVIATION... 1115 PM CST SAT NOV 17 2012 AN UPPER LEVEL DISTURBANCE WAS SPINNING ACROSS NORTHERN PARTS OF THE REGION TONIGHT...RESULTING IN SOME MID/HIGH LEVEL CLOUDINESS. CIGS WERE MOSTLY 6-10 10 KFT...AND EXPECT THEM TO CLEAR AROUND 15Z OR SO SUN WITH THE EXIT OF THE SHORTWAVE. MORE MID/HIGH LEVEL CIGS WILL RETURN SUNDAY NIGHT AS ANOTHER SHORTWAVE APPROACHES FROM THE SOUTHERN PLAINS. THIS SYSTEM COULD PRODUCE SOME LIGHT PCPN CHANCES...WITH THE BETTER CHANCES COMING AFTER 06Z MONDAY. WINDS WILL STAY UP TONIGHT AS THE TIGHT PRESSURE GRADIENT REMAINS...AND SUN AFTERNOON SHOULD BE FAIRLY SIMILAR TO SAT AFTERNOON. EXPECT MIXING TO RESULT IN AFTERNOON GUSTINESS...CLOSE TO 25 KTS AT KRST. && .ARX WATCHES/WARNINGS/ADVISORIES... 212 AM CST SUN NOV 18 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
824 AM CST SUN NOV 18 2012 .DISCUSSION... 321 AM CST SYNOPSIS...SOME THINGS BECOME CLEARER WHILE OTHER PARTS OF THE FORECAST BECOME MORE MUDDLED. OVERALL A GRADUAL WARMING PATTERN IS STILL EXPECTED THROUGH MONDAY...WITH TEMPERATURES WELL ABOVE NORMAL WEDNESDAY AND THANKSGIVING. NO SIGNIFICANT PRECIP IS EXPECTED. TODAY THROUGH MONDAY... HIGH PRESSURE CURRENTLY CENTERED OVER SOUTHEASTERN QUEBEC/UPPER NEW ENGLAND STRETCHES THROUGH THE MISSISSIPPI RIVER VALLEY. THE HIGH WILL REMAINED CENTERED THERE THROUGH EARLY NEXT WEEK WITH RELATIVELY QUIET WEATHER EXPECTED LOCALLY. TEMPS WILL BE AROUND 60 TODAY WITH CLEAR SKIES AND SOUTHERLY FLOW. CLOUDS INCREASE TOMORROW AS A THROUGH OF LOW PRESSURE/WEAK COLD FRONT APPROACH FROM THE WEST. AS SUCH WENT WITH TEMPS A DEGREE OR TWO COOLER ON MONDAY...BUT STILL WELL ABOVE AVERAGE. MONDAY NIGHT AND TUESDAY... LOW PRESSURE CURRENTLY OVER WESTERN BRITISH COLUMBIA WILL PUSH EASTWARD THROUGH CANADA...AND MODELS CONTINUE TO PUSH THE LOW FURTHER NORTH. THE LOWS COLD FRONT/LOW PRESSURE TROUGH WILL PASS THROUGH THE AREA. FORCING REMAINS WEAK ALONG THE COLD FRONT THEREFORE EXPECTING A FEW HUNDREDTHS AT BEST MONDAY EVENING THROUGH MONDAY NIGHT. GUIDANCE INDICATES THE TROUGH/COLD FRONT WEAKENS AS IT APPROACHES THE CWA SO THE BEST CHANCE OF PRECIP LOOKS TO BE OVER THE WESTERN AND NORTHERN PORTIONS OF THE CWA MONDAY NIGHT. AND BY BEST CHANCE I MEAN BEST VERY VERY SLIGHT CHANCE. PRECIP MOVES OUT BY TUESDAY MORNING AND HIGH PRESSURE QUICKLY MOVES OVER THE CWA. THINKING TEMPS WILL ONCE AGAIN BE A DEGREE OR TWO HIGHER THAN MONDAY DUE TO WEAK UPPER LEVEL WAA AND CLEARING SKIES. WEDNESDAY AND THANKSGIVING... SOUTHERLY FLOW RETURNS IN FORCE WEDNESDAY AS THE HIGH PRESSURE SLIDES TOWARD THE SOUTHEAST US. 850 HPA TEMPS SOAR TO AROUND 10C WEDNESDAY AND THANKSGIVING...THEREFORE WENT A FEW DEGREES ABOVE ALL-BLEND GUIDANCE ONCE AGAIN. ITS LOOKING LIKE THURSDAY MAY BE THE WARMER OF THE TWO DAYS WITH TEMPS BOTH DAYS AT OR ABOVE 60 DEGREES. MOST PEOPLE WOULD AGREE THAT IS SOMETHING TO BE THANKFUL ABOUT. EXTENDED...THANKSGIVING NIGHT THROUGH SATURDAY... WHAT HAPPENS THANKSGIVING EVENING/NIGHT IS THE BIG FORECAST QUESTION. THE GEM AND ECMWF INDICATE LOW PRESSURE WILL MOVE FROM THE CENTRAL PLAINS THROUGH WISCONSIN WITH ITS COLD FRONT MOVING THROUGH THE CWA THANKSGIVING NIGHT. THE GFS ON THE OTHER HAND HAS THE LOW MOVING MUCH FARTHER NORTH OVER CENTRAL ONTARIO AND QUEBEC. THE GFS SOLUTION IS ALSO MUCH FASTER THAN THE OTHER TWO SOLUTIONS. SINCE THE GEM AND ECMWF ARE MERGING TOWARD EACH OTHER...LEANING TOWARD THAT SOLUTION. THERE ARE ENOUGH DIFFERENCES IN THE SOLUTIONS THAT DECIDED TO NOT MAKE ANY ADJUSTMENTS TO THE ALL-BLEND TEMPS OR SLIGHT CHANCE POP FORECAST. THAT BEING SAID...IF THE ECMWF SOLUTION IS TO BE BELIEVED...A SIGNIFICANT TEMPERATURE DROP WILL BE EXPECTED BETWEEN THANKSGIVING AND FRIDAY. BY FRIDAY AFTERNOON 850 HPA TEMPS ARE WELL BELOW ZERO. THE GFS FEATURES A MUCH WEAKER COLD AIR PUSH SINCE ITS UPPER LEVEL PATTERN IS VERY ZONAL. NONETHELESS IT DOES FEATURE 850 HPA TEMPS BELOW ZERO MOVING OVERHEAD SATURDAY. JEE && .CLIMATE... 321 AM CST A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY 1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER. NORMALS... CHICAGO ROCKFORD MAX MIN MAX MIN NOV 01 56 38 56 36 NOV 17 47 32 47 30 NOV 30 40 27 39 24 THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT: CHICAGO ROCKFORD NOV 21 72 1913 73 1913 NOV 22 69 1913 69 2010 TRS/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * LAKE BREEZE MOVING INLAND TO MDW AND ORD VC 21-22Z TIME-FRAME. TRS //DISCUSSION...UPDATED 14Z... LATEST RUC AND HRR MODEL OUTPUT SUGGESTING A WEAK LAKE BREEZE... SUCH AS OCCURRED FRI AND SAT...DEVELOPING AND MOVING INLAND TO MDW AND ORD VC 21-22Z TIME-FRAME. WINDS EXPECTED TO BECOME A BIT MORE SOUTHERLY LATE MORNING AND EARLY AFTERNOON AND THE BACKING TO SE-ESE THERE TERMINALS FOR LATE AFTERNOON INTO EARLY EVE. TRS PREVIOUS...UPDATED 12Z... HIGH PRESSURE PARKED OVER THE EASTERN UNITED STATES WILL MAINTAIN HIGH CLOUDS AND RELATIVELY LIGHT SOUTH TO SOUTHEASTERLY WINDS OVER THE LOCAL TERMINALS. ALTHOUGH LATEST ASOS OBS AT ISSUANCE TIME WERE SHOWING CALM WINDS...OPTED TO KEEP A SSE DIRECTION AND 5 KTS IN THE TAFS TO HELP CRAFT A PLAN TO START OF THE DAY. THIS ALSO MATCHES THE WINDS REPORTED ELSEWHERE AROUND ORD AS RELAYED BY THE CWSU. DID NOT ATTEMPT TO PIN DOWN GUSTS OR MINOR VARIATIONS IN DIRECTION THAT COULD OCCUR THROUGHOUT THE DAY...THOUGH THERE IS A CHANCE THAT WINDS COULD TURN FARTHER TO THE EAST IN RESPONSE TO A LAKE BREEZE INFLUENCE. LENNING //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE IN VSBYS STAYING WELL ABOVE IFR...BUT BRIEF REDUCTIONS DUE TO HAZE ARE POSSIBLE THROUGH SUNRISE. * MEDIUM TO HIGH CONFIDENCE ON WIND TRENDS TODAY AND THIS EVENING. LENNING //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN. TUESDAY AND WEDNESDAY...VFR. THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE. FRIDAY AND SATURDAY...VFR. LENNING && .MARINE... 249 AM CST A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK. THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER AWAY TOWARD THE ATLANTIC COAST. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
428 AM MST SUN NOV 18 2012 .UPDATE... ISSUED AT 428 AM MST SUN NOV 18 2012 THOUGH MID LEVEL CLOUDS HAVE OCCASIONALLY MOVED ACROSS THE AREA EARLY THIS MORNING...LOW TEMPERATURES AT KITR/KMCK DROPPED INTO THE MID 20S. ADJUSTED THE SHORT TERM GRIDS TO REFLECT THE COOLER TEMPERATURES. TRIBUNE REPORTED SOME LIGHT FOG EARLIER THIS MORNING...AND THE LATEST HRRR CONTINUES TO DEVELOP FOG ACROSS SHERMAN AND THOMAS COUNTIES AFTER SUNRISE. WILL KEEP FOG MENTIONED IN THE FORECASTS FOR A FEW MORE HOURS. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 145 AM MST SUN NOV 18 2012 SUMMARY...DRY WEATHER WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE SHORT TERM PART OF FORECAST. TODAY...DEW POINT DEPRESSIONS CONTINUE TO LOWER EARLY THIS MORNING. LATEST FOG PRODUCT SATELLITE IMAGERY DOES NOT SHOW ANY EVIDENCE OF FOG FORMATION YET...BUT WITH LIGHT SURFACE WINDS...EXPECT SOME PATCHY FOG TO DEVELOP SHORTLY BEFORE SUNRISE MAINLY ALONG HIGHWAY 83. LATEST HRRR MODEL SUPPORTS THIS. OTHERWISE...A WEAK SHORTWAVE TROUGH WILL MOVE ACROSS THE FORECAST AREA DURING THE DAY...BUT RAOBS/MODELS CONTINUE TO SHOW THAT THE AIR MASS WILL BE DRY. ONLY MID AND HIGH LEVEL CLOUDS WILL ADVECT ACROSS THE AREA THIS AFTERNOON. LEE SIDE SURFACE TROUGH WILL MOVE EAST THIS AFTERNOON AND WILL SWITCH WINDS TO THE WEST ALONG THE COLORADO/KANSAS BORDER. WITH LACK OF AIR MASS CHANGE...EXPECT TEMPERATURES TO BE SIMILAR TO THOSE THAT OCCURRED SATURDAY. TONIGHT...500 MB FLOW BECOMES INCREASINGLY ZONAL BEGINNING TONIGHT. MODELS SHOW WEAK COLD AIR ADVECTION AT THE SURFACE STARTING AROUND 12Z. MONDAY...DRY ZONAL MID LEVEL FLOW WILL CONTINUE. SURFACE WINDS WILL BE NORTH BEHIND A PUSH OF SLIGHTLY COOLER AIR. ALTHOUGH 850 MB TEMPERATURES COOL...THE COOLING IS VERY SLIGHT...ONLY ABOUT 1 DEGREE CELSIUS. ONCE AGAIN...PERSISTENCE TEMPERATURE FORECASTS LOOK DECENT. MONDAY NIGHT THROUGH TUESDAY NIGHT...500 MB RIDGE AND ASSOCIATED SUBSIDENCE WILL DEVELOP OVER THE HIGH PLAINS. LEE SIDE TROUGH WILL REFORM BY TUESDAY AFTERNOON BRINGING A RETURN OF SOUTH WINDS AND WEAK WARM AIR ADVECTION. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 145 AM MST SUN NOV 18 2012 VERY LITTLE HAS CHANGED IN THE EXTENDED PERIODS WITH MODELS STILL ADVERTISING PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK ALONG US/CANADA BORDER. THERE ARE A FEW WEAK SHORTWAVE TROUGHS THAT COME CLOSE TO THE CWA...HOWEVER WITH A DEEP DRY LAYER IN PLACE THE MOST WE WOULD EXPECT TO SEE IS AN INCREASE IN MID-HIGH CLOUDS. RH VALUES STILL LOOK TO BE NEAR RFW CRITERIA WEDNESDAY AFTERNOON...HOWEVER SURFACE GRADIENT IS WEAK OVER THE CWA AND WINDS SHOULD BE WELL BELOW CRITERIA. OVERALL...STILL EXPECTING ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS TO CONTINUE. WED HIGHS WILL APPROACH 70F...WITH HIGHS IN THE UPPER 50S/NEAR 60F THROUGH THE REMAINING PERIODS AFTER A WEAK COLD FRONT MOVES THROUGH THE REGION WED NIGHT/THU. OVERNIGHT LOWS SHOULD BE IN THE LOW TO MID 30S EACH NIGHT...WHICH IS IS STILL ABOUT 10F ABOVE NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 428 AM MST SUN NOV 18 2012 THE MAIN ISSUE WITH THIS FORECAST IS WHETHER FOG WILL FORM FROM 12-15Z. THE LATEST HRRR BRINGS LOWER VISIBILITIES TO KGLD...BUT NOT TO KMCK. SATELLITE IMAGERGY CONTINUES TO SHOW NO EVIDENCE OF FOG. GIVEN DEW POINT DEPRESSIONS OF 2-3 DEGREES AND LITTLE WIND...WILL KEEP MENTION OF FOG WITH VISIBILITIES AROUND THREE MILES AT KGLD. WILL KEEP KMCK FREE OF ANY FOG. REGARDLESS...BOTH SITES WILL BE VFR AFTER 16Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...MENTZER SHORT TERM...MENTZER LONG TERM...DR AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
823 AM EST SUN NOV 18 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINTAIN DRY WEATHER AND SEASONAL TEMPERATURES ACROSS THE REGION THROUGH THANKSGIVING. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ANOTHER COOL START TO THE MORNING...BUT TEMPERATURES WILL REBOUND NICELY THIS AFTERNOON DUE TO WAA AND KATABATIC WINDS. RIDGES ARE ALREADY MIXED EVIDENT BY LBE IN THE LOWER 40S AS OF 13Z. LOWER ELEVATIONS WILL CATCH UP BY LATE MORNING AS A MCLR SKY IS AGAIN PREDICTED. BUMPED MAXT TEMPS UP A CATEGORY...DUE TO A POSITIVE H8 24HR DELTA OF 2-3 AND MODEST SE WIND TRAJECTORY. HRRR DID AN EXCELLENT JOB ON MAXT YDY...SO FOLLOWED IT TODAY...BUT SHAVED A DEGREE OR TWO OFF THE LOWLANDS IMMEDIATELY ADJACENT TO THE MTNS. THAT SAID...LOOK FOR UPPER 50S TO LOWER 60S TO BE COMMON THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... VERY LITTLE CHANGE IN THE PATTERN UNTIL LATE TUESDAY/WEDNESDAY... WHEN A SHORTWAVE TROUGH WILL SWING THROUGH THE OHIO VALLEY. WILL CONTINUE WITH A DRY FORECAST, AS UPPER LEVEL SUPPORT IS WEAK AND DEEP MOISTURE IS LACKING. THE MAIN EFFECT FROM THE FEATURE WILL BE AN INCREASE IN CLOUDS TUE NIGHT/WED MORNING. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... HIGHLIGHTS... - MEDIUM TO HIGH CONFIDENCE - NO BIG STORMS OVER THE LONG HOLIDAY WEEKEND - NEAR NORMAL TEMPERATURES - FOLLOWED ECMWF EXTENDED FORECAST REMAINS RATHER UNEVENTFUL WHICH IS GOOD GIVEN THE TIME OF YEAR AND THE LARGE NUMBER OF PEOPLE OUT TRAVELING FOR THE UPCOMING HOLIDAY WEEKEND. A TRANSITORY H5 ANTI-CYCLONE ALLOWS A SUNNY AND MILD TURKEY DAY. THE NEXT SYNOPTIC FEATURE WILL BE A WEAK BAROCLINIC ZONE THE SECOND HALF OF FRIDAY. AGAIN...NOT MUCH IN THE WAY OF MOISTURE WITH THIS SYSTEM SO EXPECT MINIMAL QPF AT BEST. NW FLOW RESULTING FROM FAIRLY SIGNIFICANT HEIGHT FALLS OVER NEW ENGLAND ALLOW FOR LAKE EFFECT RW/SW TO DEVELOP SAT. H8 TEMPS AT THIS TIME ARE PROGGED IN THE -8 TO -10C RANGE...BUT DUE TO LESS THAN OPTIMAL INVERSION HEIGHTS...LITTLE ACCUMULATION IS PROJECTED SATURDAY. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... HIGH PRES WL MAINTAIN VFR WEATHER WITH A CLEAR SKY AND LGT WND THROUGH TODAY. .OUTLOOK.../TONIGHT THROUGH THURSDAY/... NO WIDESPREAD RESTRICTION AREAS ARE EXPECTED THIS WEEK ALTHOUGH A CROSSING DISTURBANCE MAY SPAWN SOME LGT SHOWERS AND MID LVL CLDS ON TUESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ NEAR TERM...98
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
301 AM MST SUN NOV 18 2012 .DISCUSSION... CURRENTLY...JET FLOW MOVING FROM SOUTHWEST TO NORTHEAST ACROSS THE HEART OF NEW MEXICO...WITH CLINIC IN INERTIAL INSTABILITY ON IR IMAGERY SHOWING COLDEST CLOUD TOPS ON THE NORTH EDGE OF THE FLOW...WITH WARMER TOPS TO THE SOUTH AND EAST. DESPITE IMPRESSIVE SATELLITE DISPLAY...PRECIPITATION HAS BEEN MODEST UPSTREAM...AS DRY AIR MASS AT THE SURFACE IS EVAPORATING MUCH OF WHAT WOULD BE FALLING BEFORE IT HITS THE GROUND. DOME OF HIGH PRESSURE SITTING OVER WESTERN COLORADO WORKING WITH SURFACE TROUGH EXTENDING FROM SOUTHEAST COLORADO ACROSS EASTERN NEW MEXICO TO THE TEXAS BIG BEND COUNTRY...AND THIS MIGHT PERMIT SOME LOW LEVEL STRATUS PENETRATION DRIFTING OUT OF TEXAS AND INTO EASTERN NEW MEXICO HEADING TOWARD SUNRISE. MODELS...IN REASONABLE AGREEMENT THROUGH THE THANKSGIVING HOLIDAY WEEKEND...WITH SOME SIGNIFICANT DIFFERENCES IN PATTERN EVOLUTION AS THE FOLLOWING WORK WEEK GETS STARTED. GOOD CONSENSUS HAS SOUTHWEST FLOW IN CIRCULATION ABOUT NEW GULF OF ALASKA CLOSED LOW CIRCULATING SHORT WAVES AGAINST THE CALIFORNIA COAST THROUGH THE DAY TODAY AND INTO TONIGHT...WITH THESE WAVES PROPAGATING QUICKLY EASTWARD ACROSS NEW MEXICO. WAVE INTENSITY DIMINISHING SHARPLY BY MONDAY MORNING...AS FLOW ALOFT RESETS TO ZONAL...AND BAGGY TROUGH BUILDS FROM SOUTHERN CALIFORNIA SOUTHWARD ACROSS THE TROPICAL EAST PACIFIC ALONG THE BAJA PENINSULA. AS GULF OF ALASKA CLOSED LOW SHIFTS TO THE QUEEN CHARLOTTE ISLANDS OFF THE BRITISH COLUMBIA COAST TUESDAY...RIDGE WILL BUILD OUT OF CENTRAL MEXICO NORTHWARD ACROSS NEW MEXICO AND INTO THE NORTHERN PLAINS...AS EAST PACIFIC TROUGH BEGINS SHEAR TO THE EAST ACROSS ARIZONA...AND THROUGH NEW MEXICO ON WEDNESDAY. WITH TROUGH EXITING TO THE CENTRAL PLAINS ON THANKSGIVING...WINDS ALOFT WILL DECREASE OVER NEW MEXICO...AND RIDGING BUILDS NORTHWARD OUT OF CHIHUAHUA ACROSS NEW MEXICO TO THE SNAKE RIVER VALLEY OF IDAHO AND THE BITTERROOT RANGE OF WESTERN MONTANA. RIDGE WILL START EASTWARD DRIFT ON SATURDAY WITH NEXT TROUGH DEEPENING ON THE WEST COAST AND STARTING SLOW TREK EAST THROUGH SUNDAY. MODELS PART WAYS ON MONDAY...AS DOMESTIC GFS BUILDS AMPLIFYING RIDGE NORTHWARD OVER THE EAST PACIFIC TO PLACE NEW MEXICO IN NORTHWEST FLOW FOR THE FIRST HALF OF THE WORK WEEK. EUROPEAN COLLEAGUES AT ECMWF DIG AMPLIFYING AND MUSCULAR TROUGH OVER THE WESTERN U.S...PLACING NEW MEXICO IN INTENSIFYING SOUTHWEST FLOW IN CIRCULATION ABOUT CLOSED LOW OVER SOUTHWEST CANADA. WILL CONCUR WITH HPC COLLEAGUES WHO POINT OUT GFS TENDENCY TO BE A LITTLE TOO QUICK WITH THIS KIND OF PATTERN...AND WILL LEAN THE FIRST OF THE WORK WEEK TOWARD ECMWF FOR NOW. FOR TODAY...BROAD CLOUDINESS ACROSS NEW MEXICO AS PACIFIC MOISTURE IS SHOVED NORTHWARD AND EASTWARD FROM THE CALIFORNIA COAST IN SOUTHWEST FLOW ALOFT AND AT THE SURFACE. BROAD SHOWER COVERAGE ACROSS WESTERN AND SOUTHERN NEW MEXICO...WITH INCREASED SHOWER COVERAGE AND INTENSITY MAINLY SOUTH OF A LINE FORM ROSWELL TO CLOVIS NEAR THE LEA AND EDDY COUNTY LINES. UP NORTH...A FEW SPOTTY SHOWERS MAY DUST THE SAN JUAN MOUNTAIN PEAKS WITH SNOW NEAR THE COLORADO LINE...WITH LIGHT RAIN MOSTLY OVER SLOPES AND VALLEYS. DEEPENING SURFACE TROUGH FROM EASTERN COLORADO TO THE TEXAS BIG BEND COUNTRY WILL HELP PRODUCE SOME SOUTHWEST BREEZES IN SPOTS OVER THE EASTERN PLAINS THIS AFTERNOON. SOME COOLER AIR FILTERING IN FROM THE NORTH WILL TAKE THE EDGE OFF AFTERNOON TEMPERATURES OVER THE NORTHERN TIER...WITH WARMING TREND CONTINUING ELSEWHERE. EASTERN PLAINS TEMPERATURES WILL RUN 5 TO 10 DEGREES ABOVE NORMAL...WITH NEAR NORMAL TEMPERATURES IN THE EAST. FOR MONDAY...ZONAL FLOW BECOMING ESTABLISHED OVER THE STATE AS NEXT WEST COAST SYSTEM WITH IMPRESSIVE CIRCULATION DRIFTS OUT OF THE GULF OF ALASKA ALONG THE WEST COAST OF CANADA. SOMEWHAT COOLER AIR MASS IN PLACE OVER NEW MEXICO WILL WORK AGAINST CLEARING SKIES AND INCREASES IN SUNSHINE TO KEEP DAYTIME MAXIMUM TEMPERATURES STEADY. SURFACE LOW WILL SHIFT OUT OF EASTERN COLORADO TO THE TEXAS PANHANDLE...ALLOWING LOW LEVEL WINDS TO SHIFT NORTHWEST AND TAP AIR A FEW DEGREES COOLER THROUGH THE DAY. SOME NORTHWEST TO WESTERLY BREEZES POSSIBLE MONDAY AFTERNOON OVER THE EASTERN SLOPES AND ADJACENT PLAINS OF THE CENTRAL MOUNTAIN CHAIN. FOR TUESDAY...RIDGING OVER NEW MEXICO AS BIG BAGGY TROUGH OVER THE BAJA PENINSULA ATTEMPTS TO SHOVE SOME CLOUD AND MOISTURE OUT OF CHIHUAHUA AND THE TEXAS BIG BEND COUNTRY INTO SOUTHEAST NEW MEXICO. MOISTURE WILL BE SLOW IN COMING...AND MOST SHOULD STAY SOUTH OF OUR FORECAST AREA THROUGH TUESDAY NIGHT. STRONG SOUTHERLY COMPONENT TO SURFACE WINDS IN RETURN FLOW. TEMPERATURE TRENDS REMAINING FAIRLY STEADY TUESDAY AFTERNOON...WITH A LITTLE WARMING IN THE WEST OFFSET BY A DEGREE OR TWO OF COOLING IN THE EAST. FOR WEDNESDAY...SHOWERS OVER SOUTHERN NEW MEXICO EXPANDING NORTHWARD TO INTERSTATE 40 WEDNESDAY AFTERNOON...AND THEN SHIFTING FOCUS TO THE SOUTHEAST PLAINS BY WEDNESDAY NIGHT. SOME SOUTHWEST BREEZES OVER THE NORTHEAST PLAINS WEDNESDAY AFTERNOON...HELPED BY DEEPENING SURFACE TROUGH FROM EASTERN COLORADO INTO NORTHEAST NEW MEXICO. STEADY TEMPERATURE TRENDS CONTINUING. OUTLOOK...THANKSGIVING DAY THROUGH SATURDAY...ZONAL FLOW BACK IN PLAY FOR THANKSGIVING DAY UNDER SUNNY SKIES...AND THE LAST OF THE ISOLATED SHOWERS MOVING OUT OF THE SOUTHEAST PLAINS INTO THE HEART OF TEXAS...AND TEMPERATURES STEADY AND ABOVE NORMAL. SAME BASIC STORY FOR FRIDAY. BAGGY TROUGH REDEVELOPING OVER NORTHWEST MEXICO AND THE ADJACENT TROPICAL EAST PACIFIC ON SATURDAY...AS COLD FRONT SAGS SOUTHWARD ACROSS THE EASTERN PLAINS AND TO THE MEXICO BORDER ON SATURDAY. THIS WILL TAKE A FEW DEGREES OFF THE SATURDAY HIGH TEMPERATURE...BUT TEMPERATURES WILL REMAIN 3 TO 8 DEGREES ABOVE LATE NOVEMBER NORMALS. SHY && .FIRE WEATHER... CLOUDS WILL CONTINUE TO STREAM FROM SOUTHWEST TO NORTHEAST ACROSS THE DISTRICT TODAY. THE BEST CHANCES FOR SHOWERS WILL BE OVER THE SOUTHERN THIRD OR SO OF NEW MEXICO WHERE THE DEEPEST MOISTURE AND STRONGEST ATMOSPHERIC LIFT ARE CO-LOCATED. AS THE WEAK UPPER LEVEL PACIFIC TROUGH RESPONSIBLE FOR THE CLOUDS AND SHOWERS OVER SOUTHERN AND CENTRAL NM EJECTS EAST-NORTHEAST THIS AFTERNOON...VERY DRY AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL MOVE IN FROM THE WEST-SOUTHWEST AND BRING A GRADUAL END TO THE SHOWERS. SLIGHTLY COOLER AIR WILL FILTER INTO THE NORTHWEST HALF OF NM THIS AFTERNOON. AS THE COOLER AIR FILTERS IN FROM THE NORTHWEST AND HIGHER DEW POINT LEVELS REMAIN IN PLACE.... VERY GOOD TO EXCELLENT HUMIDITY RECOVERIES ARE EXPECTED OVERNIGHT. THE ONE EXCEPTION WILL BE OVER NORTHEAST NM WHERE BREEZY DOWN SLOPE WEST WINDS WIND WILL KEEP RH RECOVERIES IN THE FAIR TO GOOD RANGE. THE NAM...GFS...AND EUROPEAN WEATHER PREDICTION MODELS ARE IN VERY GOOD AGREEMENT WITH REGARD TO A WEAK UPPER LEVEL TROUGH EJECTING NORTHEASTWARD FROM THE BAJA ACROSS FAR NORTHWEST MEXICO AND SOUTHERN AND CENTRAL NEW MEXICO TUESDAY NIGHT AND WEDNESDAY. AHEAD OF THE SYSTEM...A MOIST SOUTHERLY FLOW WILL TAP UNSEASONABLY DEEP SUBTROPICAL MOISTURE FROM OLD MEXICO. THE GFS IS QUITE A BIT MORE VIGOROUS THAN THE EUROPEAN MODEL WITH THE MOISTURE TRANSPORT AND THE ATMOSPHERIC LIFT ASSOCIATED WITH THE UPPER TROUGH PASSAGE. IN ANY EVENT...THE OVERALL MODEL TREND IS WETTER...WITH THE POTENTIAL FOR SCATTERED WETTING PRECIPITATION OVER THE SOUTH...AND POSSIBLY AS FAR NORTH AS INTERSTATE 40 FOR WEDNESDAY. AFTER GOOD TO EXCELLENT VENTILATION IN MOST LOCATIONS OVER THE WEEKEND...POOR VENTILATION WILL SPREAD ACROSS CENTRAL AND WESTERN PARTS OF THE FORECAST AREA FROM THE WEST DURING THE FIRST HALF OF THE COMING WORK WEEK. VENTILATION IS EXPECTED TO IMPROVE OVER SOUTHERN AND CENTRAL NEW MEXICO...ASSOCIATED WITH THE PASSING THE WEAK UPPER LEVEL TROUGH AND THE ASSOCIATED PRECIPITATION. ECMWF AND CANADIAN MODEL ARE IN VERY GOOD AGREEMENT WITH ONE ANOTHER FOR NEXT WEEKEND INTO EARLY NEXT WEEK...HINTING AT A MAJOR WEATHER PATTERN CHANGE TOWARD COLDER AND WETTER CONDITIONS. STAY TUNED. 33 && .AVIATION... 06Z TAF CYCLE MID/HIGH LEVEL MOISTURE BOWING NORTHWARD OVER SOUTHERN AND CENTRAL NEW MEXICO...WHILE TOP DOWN MOISTENING TO CONTINUE...MAINLY EMBEDDED SCATTERED LIGHT SHOWERS WILL RESULT...WHICH MAY OBSCURE HIGHER TERRAIN FAVORING AREAS SOUTH OF HIGHWAY 60 NEXT 12 HOURS. IN ADDITION...DISTURBANCE PASSING THROUGH GREAT BASIN AND CENTRAL ROCKIES MAY RESULT IN ISOLD -RASN OR EVEN A SHORT LIVED THUNDERSTORM NEAR THE FOUR CORNERS AND THE NORTHWEST MTS AND MAY RESULT IN BRIEF MT OBSCURATION THRU 12Z SUNDAY. 00Z NAM12 AND LATEST RUC INDICATE SOME LOW/MID LEVEL MOISTURE MAY MAKE A RUN UP THE RGV POSSIBLY REACHING KABQ BY 12Z SUNDAY...THEREFORE MORE WIDESPREAD MT OBSCURATION POSSIBLE BUT CIGS MAY REMAIN VFR. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 57 27 58 27 / 10 5 5 0 DULCE........................... 53 19 54 17 / 20 5 5 0 CUBA............................ 57 24 56 22 / 10 0 5 0 GALLUP.......................... 56 22 55 19 / 10 5 5 0 EL MORRO........................ 52 20 52 18 / 10 5 0 0 GRANTS.......................... 59 24 59 21 / 10 0 0 0 QUEMADO......................... 58 29 57 25 / 5 5 0 0 GLENWOOD........................ 65 29 65 27 / 10 5 0 0 CHAMA........................... 49 22 49 17 / 20 5 5 0 LOS ALAMOS...................... 54 32 53 30 / 10 5 0 0 PECOS........................... 54 32 55 29 / 5 0 0 0 CERRO/QUESTA.................... 53 21 53 19 / 5 5 0 0 RED RIVER....................... 46 19 47 15 / 5 5 5 0 ANGEL FIRE...................... 50 21 51 15 / 5 5 5 0 TAOS............................ 55 20 55 15 / 5 5 0 0 MORA............................ 56 28 56 25 / 5 5 0 0 ESPANOLA........................ 61 26 60 25 / 5 0 0 0 SANTA FE........................ 55 32 55 28 / 5 5 0 0 SANTA FE AIRPORT................ 58 28 57 27 / 5 0 0 0 ALBUQUERQUE FOOTHILLS........... 60 35 59 33 / 5 0 0 0 ALBUQUERQUE HEIGHTS............. 60 37 60 35 / 5 0 0 0 ALBUQUERQUE VALLEY.............. 63 34 62 31 / 5 0 0 0 ALBUQUERQUE WEST MESA........... 62 34 61 32 / 5 0 0 0 LOS LUNAS....................... 63 29 62 26 / 5 0 0 0 RIO RANCHO...................... 61 34 60 32 / 5 0 0 0 SOCORRO......................... 68 34 67 31 / 10 0 0 0 SANDIA PARK/CEDAR CREST......... 59 33 58 31 / 10 0 0 0 TIJERAS......................... 61 33 59 31 / 10 0 0 0 MORIARTY/ESTANCIA............... 61 24 60 21 / 5 0 0 0 CLINES CORNERS.................. 58 31 58 30 / 5 0 0 0 GRAN QUIVIRA.................... 60 34 60 31 / 10 5 0 0 CARRIZOZO....................... 64 35 65 30 / 20 5 0 0 RUIDOSO......................... 58 37 60 35 / 20 5 5 0 CAPULIN......................... 60 31 59 29 / 5 5 5 0 RATON........................... 62 25 62 23 / 0 5 5 0 SPRINGER........................ 63 26 63 24 / 0 5 5 0 LAS VEGAS....................... 60 31 60 27 / 0 5 5 0 CLAYTON......................... 69 37 68 34 / 5 5 5 0 ROY............................. 64 33 63 31 / 0 5 5 0 CONCHAS......................... 69 34 69 30 / 5 5 0 0 SANTA ROSA...................... 69 37 69 32 / 5 5 0 0 TUCUMCARI....................... 71 37 70 30 / 5 5 5 0 CLOVIS.......................... 68 39 69 34 / 20 5 5 0 PORTALES........................ 68 39 70 33 / 20 5 5 5 FORT SUMNER..................... 69 38 70 33 / 10 5 0 0 ROSWELL......................... 74 41 76 35 / 20 5 0 0 PICACHO......................... 70 39 70 34 / 20 5 5 0 ELK............................. 66 41 66 36 / 30 5 5 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHY
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
559 AM CST SUN NOV 18 2012 .SHORT TERM...THROUGH TUESDAY NIGHT 212 AM CST SUN NOV 18 2012 MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TONIGHT INTO MONDAY AS WELL AS TEMPERATURES THROUGHOUT. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP TROUGH FROM JUST OFF THE COAST OF BRITISH COLUMBIA INTO THE PACIFIC NORTHWEST...AND SOUTHWEST FLOW FROM THE DESERT SOUTHWEST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION. WITHIN THIS SOUTHWEST FLOW...SHORTWAVES OF NOTE ARE ALONG THE UTAH/COLORADO BORDER AND IN NORTHWEST MINNESOTA. DPVA AHEAD OF THIS LATTER SHORTWAVE COMBINED WITH 295-300K ISENTROPIC LIFT PRODUCED SHOWERS ACROSS NORTHEAST MINNESOTA. THE 295K ISENTROPIC LIFT ALSO EXTENDED SOUTHWEST FROM NORTHEAST MINNESOTA INTO CENTRAL IOWA...AND ALONG THIS ZONE IS A BAND OF STRATUS WITH CEILINGS BETWEEN 6000-9000 FT. THE BAND OF STRATUS ALSO SEPARATES MOIST AIR FROM VERY DRY AIR AT 850MB. FOR EXAMPLE...FROM 00Z SOUNDINGS...THE 850MB DEWPOINT AT DVN WAS -20C WHILE IT WAS -2C AT MPX AND 1C AT OAX. THE BROAD SOUTHWEST FLOW ALOFT HAS RESULTED IN A WARM ADVECTION PATTERN ACROSS THE UPPER MIDWEST. 850MB TEMPS WERE +6C AT MPX AND OAX AT 00Z. THE LOW LEVEL SOUTHERLY FLOW WAS FAIRLY STRONG WITH 925MB PROFILER AND VWP DATA SHOWING SPEEDS OF 35-45KT AROUND THE FORECAST AREA. THESE WINDS ARE HOLDING TEMPERATURES UP FROM THE MID 30S TO MID 40S...WARMEST IN SOUTHEAST MINNESOTA. TODAY AND TONIGHT...FOCUS IS ON THAT SHORTWAVE ALONG THE UTAH/COLORADO BORDER. GOOD MODEL AGREEMENT REMAINS ON THIS SHORTWAVE LIFTING UP THROUGH THE SOUTHWEST FLOW AND MOVING INTO WESTERN PORTIONS OF THE FORECAST AREA BY 12Z MONDAY. BRIEF RIDGING DEVELOPS OVER THE FORECAST AREA TODAY DOWNSTREAM OF THIS SHORTWAVE...WHICH SHOULD ACT TO CLEAR THE CLOUDS UP SOMEWHAT. WITH THE RELATIVELY SPEAKING WARM START...SUNSHINE AND 925MB TEMPS AROUND 6C WHICH ARE SIMILAR TO YESTERDAY...ANTICIPATING HIGHS TO BE FAIRLY SIMILAR TO A FEW DEGREES WARMER THAN YESTERDAY. FOR TONIGHT...THE 850MB MOISTURE STREAM CURRENTLY OVER WESTERN MINNESOTA AND IOWA WILL GET PUSHED EAST INTO THE FORECAST AREA BY THE SHORTWAVE. THE MAIN QUESTION IS IF DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE WILL BE STRONG ENOUGH TO ACT ON THIS MOISTURE AND PRODUCE PRECIPITATION. MID CLOUD DEVELOPMENT IS A CERTAINTY...GIVEN WHAT HAPPENED LAST EVENING ON THE LEADING EDGE OF THE 850MB MOISTURE STREAM. THE 18.00Z NAM/REGIONAL CANADIAN PAINT A DRY PICTURE AND EVEN THE GFS WHICH LOOKS TO HAVE A BIT TOO MUCH MOISTURE COMPARED TO ALL OTHER MODELS PRODUCES LITTLE IF ANY PRECIPITATION BEFORE 12Z. THE 17.12Z ECMWF MEANWHILE REMAINS MOST ROBUST WITH 0.1-0.2 OF AN INCH OVER NORTHEAST IOWA BETWEEN 06-12Z MONDAY. NEW 18.00Z ECMWF IS SLIGHTLY DRIER. SREF TRENDS HAVE SHOWN LESS MEMBERS PRODUCING 0.01 OF AN INCH OVER THE LAST 5 RUNS...DOWN FROM 40-50 PERCENT TO 10-30 PERCENT. AT THIS POINT...CANNOT SEE GOING WITH THE MORE ROBUST ECMWF SOLUTION AND HAVE KEPT CHANCES LOW IN THE 20-30 PERCENT RANGE...CENTERED IN THE 09-12Z PERIOD. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE BEING MAINTAINED...A SLIGHTLY WARMER NIGHT THAN TONIGHT IS ANTICIPATED. MONDAY AND MONDAY NIGHT...THE SHORTWAVE OVER WESTERN PORTIONS OF THE FORECAST AREA AT 12Z LOOKS TO MOVE THROUGH THE REST OF THE FORECAST AREA BY EARLY AFTERNOON...WHILE THE TAIL END OF THE DEEP TROUGHING IN THE PACIFIC NORTHWEST IS PROGGED TO DROP DOWN INTO THE FORECAST AREA AFTER MIDNIGHT MONDAY NIGHT. THIS LATTER SHORTWAVE WILL COME THROUGH DRY SINCE THE SHORTWAVE COMING THROUGH MONDAY MORNING ENDS UP SCOURING OUT A LOT OF THE MOISTURE. THUS ALL FOCUS IS ON THE MONDAY MORNING PERIOD. AGAIN HERE...MODELS ARE AT ODDS WITH FORCING AND MOISTURE AVAILABILITY. THE 18.00Z NAM/REGIONAL CANADIAN SAYS THERE IS TOO MUCH DRY AIR BELOW 800MB AND THE FORCING IS TOO WEAK ABOVE IT TO ALLOW FOR PRECIPITATION TO MAKE IT TO THE SURFACE. ON THE OTHER HAND...THE 18.00Z GFS AND 17.12Z/18.00Z ECMWF ARE MORE ROBUST IN BOTH ARENAS AND END UP PRODUCING LIGHT QPF ACROSS MUCH OF THE AREA. SREF TRENDS FOR THE FULL DAY MONDAY ARE ALSO SIMILAR TO 06-12Z MONDAY...SHOWING A DECLINE OF MEMBERS PRODUCING AT LEAST 0.01 OF AN INCH. IT USED TO BE UP AT 70-80 PERCENT BUT NOW IS DOWN TO 30-60 PERCENT. THUS...CONFIDENCE REMAINS TOO LOW TO ADJUST THE PREVIOUS FORECAST PRECIPITATION CHANCES OF 20-40 PERCENT. CERTAINLY IF ANY PRECIPITATION OCCURS...ANY RAIN LOOKS REALLY LIGHT. REGARDING CLOUD COVER...IT NOW APPEARS THAT THE SHORTWAVE ON MONDAY MORNING SHOULD HELP TO CLEAR THE CLOUDS OUT AS IT MOVES AWAY DURING THE AFTERNOON. THERE MAY BE AN INCREASE OF CIRRUS WITH THE SHORTWAVE COMING IN MONDAY NIGHT...BUT THATS ABOUT IT. NOTE THAT THERE IS CONCERN FOR A LOW CLOUD DECK BASED ON THE GFS/ECMWF 925MB RH PROGS...BUT THEY MAY BE TOO MOIST. FOR NOW TAKING A COMPROMISE APPROACH BY SPEEDING UP THE CLEARING SOME FROM THE PREVIOUS FORECAST. HAVING MORE CLOUDS MONDAY WILL HOLD THE TEMPERATURES DOWN A FEW DEGREES FROM HIGHS OVER THE WEEKEND. A COOLER NIGHT SEEMS LIKELY TOO FOR MONDAY NIGHT...ESPECIALLY IF THE CLEARING OCCURS. TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THAT SHORTWAVE DROPPING INTO THE FORECAST AREA TUESDAY MORNING...SOME FAIRLY STRONG RIDGING IS PROGGED TO BUILD INTO THE FORECAST AREA BY TUESDAY EVENING. ABOUT ALL THAT SHORTWAVE IS GOING TO DO IS PREVENT THE 850MB TEMP CLIMB...NOTED BY 850MB TEMPS AT 18Z TUESDAY OF 5-7C. ONCE THE RIDGING STARTS BUILDING IN...THESE TEMPS CLIMB...TOPPING OUT AT 8C EAST TO 11C WEST BY 12Z WEDNESDAY. WITH WHAT SHOULD BE PLENTY OF SUN...HIGHS SHOULD BE ABLE TO TOP OUT IN THE 50S AGAIN ON TUESDAY GIVEN THE AFOREMENTIONED 850MB TEMPS. INCREASING SOUTHERLY FLOW TUESDAY NIGHT IN THE WAKE OF HIGH PRESSURE THAT CROSSES THE AREA ON TUESDAY WILL HELP TO KEEP TEMPERATURES UP IN SOUTHEAST MINNESOTA. FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT 212 AM CST SUN NOV 18 2012 MAIN FOCUS CONTINUES TO BE ON A POTENT SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST WEDNESDAY MORNING. MODEL AGREEMENT HANDLING THIS POTENT TROUGH BEGINS TO DECLINE AS EARLY AS 12Z THURSDAY...WITH THE 18.00Z ECMWF/CANADIAN SHOWING A DIGGING NATURE TO IT INTO THE NORTHERN PLAINS. MEANWHILE...THE 18.00Z GFS TAKES A MORE PROGRESSIVE APPROACH AND SENDS IT UP INTO NORTHERN ONTARIO ON THURSDAY. BOTH THE GFS AND ECMWF HAVE COMPLETELY FLIPPED FROM PREVIOUS RUNS WITH THE HANDLING OF THIS POTENT TROUGH. THE 18.00Z ECMWF LOOKS MORE LIKE THE 17.00Z GFS WHILE THE 18.00Z GFS LOOKS MORE LIKE THE 16.12Z ECMWF. THIS HAS SIGNIFICANT IMPLICATIONS ON THE TEMPERATURE AND WIND FORECASTS...PRIMARILY FRIDAY AND BEYOND. WITH THE MORE DIGGING NATURE OF THE ECMWF/CANADIAN...THEY END UP CARVING OUT A DEEP TROUGH ACROSS THE WESTERN GREAT LAKES REGION FOR FRIDAY...THOUGH WITHIN THIS GROUP THE CANADIAN IS MORE PROGRESSIVE. WHICHEVER MODEL SCENARIO PLAYS OUT...IT APPEARS DRY WEATHER WOULD BE THE RULE WITH THE BEST JUXTAPOSITION OF FORCING AND MOISTURE EITHER NORTH OR SOUTHEAST OF THE AREA. GIVEN THE DIFFERENCES EARLY IN THE LONG TERM PERIOD...HARD TO SAY HOW THE WEEKEND WILL PLAY ITSELF OUT. NOTE THAT THE 18.00Z GFS ENSEMBLES HAVE A PRETTY GOOD SPREAD TOO WITH REGARDS TO THE POTENT TROUGH. THUS FOR NOW HAVE STAYED WITH A CONSENSUS APPROACH WHEN IT COMES TO THE WEEKEND...YIELDING COOLER AND A CONTINUATION OF DRY CONDITIONS. REGARDING TEMPERATURES...WEDNESDAY AND THANKSGIVING DAY STILL LOOK WELL ABOVE NORMAL...ESPECIALLY WEDNESDAY AS 925MB TEMPS CLIMB TO 10-12C FOR 18Z. MIXING TO 925MB YIELDS HIGHS FROM THE UPPER 50S TO MIDDLE 60S...THUS HAVE BOOSTED HIGHS A FEW DEGREES. RECORD HIGHS FOR WEDNESDAY ARE 72 AT LA CROSSE AND 69 AT ROCHESTER...STILL 5-10 DEGREES ABOVE THE GOING FORECAST. NOTE THAT 850MB TEMP STANDARDIZED ANOMALIES HAVE NOW JUMPED TO NEAR 2...SUPPORTING THE INCREASING IN HIGH TEMPERATURES. SOME COOLING IN 925MB TEMPS TAKES PLACE ON THANKSGIVING DAY AS A COLD FRONT MOVES INTO THE REGION. STILL...MOST LOCATIONS SHOULD TOP OUT AT LEAST IN THE MID TO UPPER 50S...MAYBE EVEN 60 AT SOME SOUTH OF I-90. RECORD HIGH FOR THURSDAY IS 59 AT LA CROSSE AND 65 AT ROCHESTER...THUS LA CROSSE MAY BE DOABLE TO BREAK. TEMPERATURES SHOULD RETURN CLOSER TO NORMAL FOR FRIDAY INTO THE WEEKEND IN THE WAKE OF THE COLD FRONT. IF THE 18.00Z ECMWF IS CORRECT...WE COULD EVEN BE BELOW NORMAL FOR THE WEEKEND. && .AVIATION...TODAY AND TONIGHT 557 AM CST SUN NOV 18 2012 A SCATTERED TO BROKEN DECK OF ALTOCUMULUS CLOUDS WILL GRADUALLY DISSIPATE ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON. A COLD FRONT WILL BRING ANOTHER ROUND OF MID AND HIGH CLOUDS TO THE AREA TONIGHT. THERE WILL ALSO BE SOME ISOLATED TO SCATTERED SHOWERS ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA AFTER 19.06Z TONIGHT. SINCE THEIR COVERAGE IS VERY SMALL...DID NOT INCLUDE THEM AT KRST. && .ARX WATCHES/WARNINGS/ADVISORIES... 212 AM CST SUN NOV 18 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
413 PM CST SUN NOV 18 2012 .DISCUSSION... 213 PM CST TONIGHT... ANTI-CYCLONIC FEATURE HAS BECOME STRETCHED OUT WITH A CENTER OVER SOUTHEAST QUEBEC AND CONTINUES TO PROVIDE A MAIN INFLUENCE ACROSS THE OHIO VALLEY/MID-MISSISSIPPI VALLEY. TO THE WEST OF THIS INFLUENCE ACROSS PORTIONS OF THE UPPER MIDWEST/CENTRAL PLAINS...THE PRESSURE GRADIENT IS TIGHTER AND RESULTING IN OCCASIONALLY GUSTY SOUTH WINDS IN THOSE AREAS. VISIBLE IMAGERY EARLY THIS AFTERNOON DEPICTS A CHANNEL OF CIRRUS CLOUDS FROM NORTHERN IL STRETCHING WEST THROUGH IOWA...THEN A MORE EXPANSIVE AREA OF CIRRUS CLOUDS ACROSS THE SOUTHERN PLAINS INTO THE SOUTHERN ROCKIES. THE SOUTHERN ROCKIES IS THE AREA THAT GUIDANCE HAS BEEN FOCUSED ON FOR THE DEVELOPMENT OF A WEAK WAVE THAT WILL SLIDE ALONG THE FRONTAL BOUNDARY AND OVERSPREAD CLOUDS AND LGT PRECIP TO PORTIONS OF THE GREAT LAKES MON NGT. CLOUD COVER WILL STEADILY SLIDE OVERHEAD THIS EVENING/OVERNIGHT...WITH A FEW POCKETS OF CLEARING. DEEPER MOISTURE WILL REMAIN WEST OF THE CWFA THROUGH THE OVERNIGHT...MAINLY OVER IA/MO/KS/OK. WITH POTENTIALLY HIGH CLOUDS OVERHEAD SFC TEMPS SHOULD BE ABLE TO RADIATE INTO THE MID/UPR 30S ACROSS THE REGION. SFC WINDS SHOULD CONTINUE OVERNIGHT AROUND 10 MPH OR LESS...HOWEVER SHOULD BE JUST ENOUGH TO PREVENT LARGE SCALE FOG DEVELOPMENT. A FEW PROTECTED AREAS AND LOCATIONS CLOSEST TO STREAMS...MAY SEE PATCHY FOG DEVELOP. THE OTHER AREAS THAT COULD SEE PATCHY FOG MAY BE THE FAR NORTHEAST CORNER OF NORTHEAST IL...WITH A WEAK ONSHORE FLOW AND MARINE MOISTURE BLEEDING INLAND A FEW MILES. CONFIDENCE...HIGH. MONDAY THROUGH TUESDAY... ANTI-CYCLONIC FLOW IS PROGGED TO BE THE MAIN FEATURE FOR EARLY WEEK...HOWEVER A WEAK FRONTAL BOUNDARY IS PROGGED TO PUSH EAST ACROSS THE MISSISSIPPI VALLEY INTO THE GREAT LAKES MONDAY NIGHT/EARLY TUESDAY. GUIDANCE HAS CONTINUED TO HINT THAT SOME MOISTURE WILL ACCOMPANY THIS BOUNDARY...ALTHOUGH LOOKING UPSTREAM AT CURRENT CONDITIONS IT APPEARS THE SCENARIO OF LIGHT PRECIP IS LOW FOR MONDAY NIGHT/EARLY TUE. ANOTHER POTENTIAL LIMITING FACTOR IS THAT THE EXPECTED DOWNSTREAM RIDGE MAY CONTINUE TO HOLD WITH DIFFLUENT FLOW IN THE MID-LVLS...WHICH WOULD AID IN DRYING THE MOISTURE AT THE MID-LVLS. LLVL FLOW MAY BACK SLIGHTLY TO THE SOUTHEAST...WHICH COULD ALSO AID IN MOISTURE AVAILABILITY. FORCING DOES NOT APPEAR TO BE VERY POTENT EITHER. MANY PLUMES SUGGEST A DRY MON NGT/EARLY TUE AS WELL ACROSS THE CWFA. BASED ON THESE AFOREMENTIONED ELEMENTS...HAVE OPTED TO REMOVE MENTION OF PRECIP ACROSS THE CWFA FOR MON NGT/EARLY TUE...AND ADJUSTED ANY PRECIP TO LOCATIONS FURTHER NORTH ACROSS WISC/LAKE MICHIGAN/LOWER MICHIGAN. IF PRECIP DOES DEVELOP...IT APPEARS IT MAY END UP BEING SPRINKLES. OVERALL EXPECT JUST CLOUDS TO BE ON THE INCREASE FROM THIS SYSTEM. TEMPS BOTH DAYS WILL CONTINUE TO BE MILD WITH A THERMAL RIDGE OF 5 TO 7 DEG C MONDAY...AND 6 TO 8 DEG C TUESDAY. WITH OPTIMAL CONDS EXPECTED BOTH DAYS...TEMPS SHOULD EASILY WARM INTO THE MID/UPR 50S. FOR LOCATIONS ALONG AND SOUTH OF I-80 TEMPS COULD TOUCH 60 DEGREES TUESDAY AFTERNOON. SEVERAL 2M TEMP PLUMES FOR THIS PERIOD ALSO SUPPORT THIS MAX TEMP FORECAST. OVERNIGHT LOWS WILL ALSO BE MILD...UPR 30S/LOW 40S. CONFIDENCE...HIGH. PRECIP CONFIDENCE...MEDIUM/HIGH. WEDNESDAY... ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR...AND IT APPEARS MOTHER NATURE WILL COOPERATE AND PRODUCE OPTIMAL TRAVEL CONDITIONS FOR NORTHERN IL/NORTHWEST IN. ANTI-CYCLONIC FLOW WILL PUSH BACK INTO THE REGION AND ERODE THE CLOUDS TUE NGT/EARLY WED...WITH COULD ALLOW TEMPS EARLY WED BEFORE SUNRISE TO DIP INTO THE LOW 30S. THEN A LARGE DIURNAL CURVE IS EXPECTED FOR WED AFTERNOON. 850MB THERMAL RIDGE OF 7 TO 9 DEG C IS PROGGED TO SLIDE OVERHEAD FROM THE WEST/SOUTHWEST...WITH LLVL FLOW TURNING SOUTH/SOUTHWEST. THE BEST PRESSURE GRADIENT AND ADVECTION APPEARS TO BE DISPLACED TO THE NORTHWEST/WEST OF THE CWFA...HOWEVER IT APPEARS TEMPS COULD EASILY WARM TO 60 DEG ACROSS THE AREA. FOR AREAS ALONG AND WEST OF A ROCKFORD/KANKAKEE LINE...TEMPS MAY PUSH TO 61 TO 63 DEG. CONFIDENCE...HIGH. THANKSGIVING THROUGH SATURDAY... THE ANOMALOUS WARM/DRY PATTERN THAT HAS DOMINATED MUCH OF THE REGION FOR THE PAST SEVERAL DAYS...MAY BE TRANSITIONING INTO A MORE ACTIVE PATTERN. ABOVE NORMAL 500MB HEIGHTS WILL PERSIST THROUGH THUR...THEN STEADILY WEAKEN INTO A SEMI-ZONAL FLOW AND POSSIBLY A TROUGH DIGGING INTO THE UPPER MIDWEST/CENTRAL ROCKIES DEVELOPS. GUIDANCE BECOMES RATHER NOISY IN THE EXTENDED PERIODS FROM FRI-SAT...WHICH IS INDICATED BY THE ENVELOPE OF SOLUTIONS THAT THE ENSEMBLES PROG AS WELL AS OPERATIONAL GFS/ECMWF. THE FIRST FEW PERIODS WILL CONTINUE TO BE MILD WITH TEMPS NEAR 60 TO POSSIBLY THE LOW 60S IN THE AFTERNOON FOR THANKSGIVING...HOWEVER THIS WILL CHANGE FOR FRI/SAT. 500MB TROUGH CONTINUES TO BE PROGGED BY OPERATIONAL SOLUTIONS AND ANTI-CYCLONIC FLOW WILL DEPART TO THE SOUTHEAST. THIS WILL AID IN A STRENGTHENING SOUTHWEST FLOW THUR NGT/FRI AS A FRONTAL BOUNDARY BEGINS TO APPROACH THE REGION. 850MB THERMAL TROUGH OF -2 TO -5 DEG C SHOULD ARRIVE ACROSS THE REGION MIDDAY FRI...THUS TEMPS FRI MAY STRUGGLE TO WARM WITH POSSIBLY THE WARMEST TEMPS FOR THE DAY OCCURRING IN THE MORNING. 500MB SPEED MAX PIVOTS EAST ACROSS THE UPPER MIDWEST/NORTHERN GREAT LAKES...HOWEVER APPEARS TO BE MAINLY MOISTURE STARVED. AT THIS POINT HAVE CONTINUED TO MENTION CHC POPS...AND TEMPS SHOULD BE COOL ENOUGH TO PRODUCE A POSSIBLE RA/SN MIX HOWEVER MOISTURE RAPIDLY PIVOTS NORTHEAST BY FRI AFTN/EVE THAT THIS WOULD BE RESTRICTED TO THE LAKE ENVIRONMENT AND LOWER MICHIGAN. THEN ANTI-CYCLONIC FLOW IS PROGGED TO BUILD BACK INTO THE MIDWEST/GREAT LAKES REGION FOR THE REMAINDER OF THE WEEKEND AND PROVIDE DRY WEATHER. IN ADDITION THE LONGER TERM MODELS CONTINUE TO HINT THAT TEMPS MAY YET AGAIN PUSH BACK ABOVE NORMAL FOR THE SECOND HALF OF THE WEEKEND AND POSSIBLY CONTINUE INTO EARLY THE FOLLOWING WEEK. CONFIDENCE...HIGH. BEACHLER && .CLIMATE... 321 AM CST A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY 1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER. NORMALS... CHICAGO ROCKFORD MAX MIN MAX MIN NOV 01 56 38 56 36 NOV 17 47 32 47 30 NOV 30 40 27 39 24 THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE RECORD HIGH TEMPERATURES. WHILE FORECAST HIGH TEMPERATURES ARE CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT: CHICAGO ROCKFORD NOV 21 72 1913 73 1913 NOV 22 69 1913 69 2010 TRS/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * VARIABLE SE-SSE WINDS THROUGH EARLY EVENING BECOMING STEADIER SOUTHEAST. MDB //DISCUSSION...UPDATED 22Z... LAKE INFLUENCE SEEMS TO BE WEAKENING FOR AREAS EAST AND NORTH OF ORD...POTENTIALLY DUE TO INCREASING HIGH LEVEL CLOUD SHIELD. AREAS FROM UGN TO PWK THAT HAD SEEN A LARGER EAST COMPONENT TO THE SOUTHERLY WIND HAVE TURNED MORE SOUTHEASTERLY FOR THE MOST PART...WITH AREAS RIGHT ALONG THE ILLINOIS SHORE DOING SIMILAR. SO IT APPEARS THAT A LARGER SOUTH WIND COMPONENT WILL PREVAIL ACROSS THE CHI AREA TERMINALS WITH SOME VARIABILITY BETWEEN SE AND SSE AT ORD/MDW FOR THE NEXT FEW HOURS. MDB FROM 18Z... LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME. RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE. WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH POSSIBLE OCCASIONAL GUSTS OF 14-17KT. EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY SCT-BKN MID AND HIGH LEVEL CLOUDS. TRS //ORD AND MDW CONFIDENCE...UPDATED 22Z... * HIGH CONFIDENCE IN VARIABLE WIND DIRECTION THROUGH EARLY EVENING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN. TUESDAY AND WEDNESDAY...VFR. THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE. FRIDAY AND SATURDAY...VFR. LENNING && .MARINE... 225 PM CST A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM NOVA SCOTIA TO THE LOWER MISSISSIPPI VALLEY.. THE RIDGE IS EXPECTED TO ONLY DRIFT VERY SLOWLY EAST OVER THE NEXT SEVERAL DAYS WHILE GRADUALLY WEAKENING. A TROUGH OF LOW PRESSURE WILL MOVE INTO THE DAKOTAS TODAY...THEN INTO THE WESTERN GREAT LAKES MONDAY NIGHT AS IT WEAKENS SLIGHTLY. THIS WILL KEEP GENERALLY SOUTHERLY WINDS OVER THE LAKE UNTIL EARLY NEXT WEEK. AS THE TROUGH FURTHER WEAKENS TUESDAY NIGHT AND AN ASSOCIATED WEAK COLD FRONT CROSSES LAKE MICHIGAN... WINDS WILL SHIFT TO NORTHWESTERLY. HOWEVER...NO INCREASE IN WINDS IS LIKELY AS A WEAK RIDGE OF HIGH PRESSURE WILL IMMEDIATELY FILL IN BEHIND THE FRONT AND THERE IS NO SIGNIFICANTLY COLD AIR BEHIND THE FRONT. ANOTHER LOW IS FORECAST TO DEVELOP OVER MONTANA ON WEDNESDAY AND QUICKLY TRACK EASTWARD TO NEAR LAKE SUPERIOR BY THURSDAY EVENING. THE LOW WILL THEN TURN NORTHEAST TOWARD SOUTHERN JAMES BAY...DRAGGING A COLD FRONT ACROSS LAKE MICHIGAN LATE THURSDAY NIGHT OR FRIDAY MORNING. THIS FRONT IS EXPECTED TO BE MUCH STRONGER THAN THE PREVIOUS FRONT...BRINGING IN A MUCH COLDER INFLUX OF COLDER AIR...AND WILL BRING STRENGTHENING NORTHWESTERLY WINDS TO THE LAKE, KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
225 PM CST SUN NOV 18 2012 .DISCUSSION... 213 PM CST TONIGHT... ANTI-CYCLONIC FEATURE HAS BECOME STRETCHED OUT WITH A CENTER OVER SOUTHEAST QUEBEC AND CONTINUES TO PROVIDE A MAIN INFLUENCE ACROSS THE OHIO VALLEY/MID-MISSISSIPPI VALLEY. TO THE WEST OF THIS INFLUENCE ACROSS PORTIONS OF THE UPPER MIDWEST/CENTRAL PLAINS...THE PRESSURE GRADIENT IS TIGHTER AND RESULTING IN OCCASIONALLY GUSTY SOUTH WINDS IN THOSE AREAS. VISIBLE IMAGERY EARLY THIS AFTERNOON DEPICTS A CHANNEL OF CIRRUS CLOUDS FROM NORTHERN IL STRETCHING WEST THROUGH IOWA...THEN A MORE EXPANSIVE AREA OF CIRRUS CLOUDS ACROSS THE SOUTHERN PLAINS INTO THE SOUTHERN ROCKIES. THE SOUTHERN ROCKIES IS THE AREA THAT GUIDANCE HAS BEEN FOCUSED ON FOR THE DEVELOPMENT OF A WEAK WAVE THAT WILL SLIDE ALONG THE FRONTAL BOUNDARY AND OVERSPREAD CLOUDS AND LGT PRECIP TO PORTIONS OF THE GREAT LAKES MON NGT. CLOUD COVER WILL STEADILY SLIDE OVERHEAD THIS EVENING/OVERNIGHT...WITH A FEW POCKETS OF CLEARING. DEEPER MOISTURE WILL REMAIN WEST OF THE CWFA THROUGH THE OVERNIGHT...MAINLY OVER IA/MO/KS/OK. WITH POTENTIALLY HIGH CLOUDS OVERHEAD SFC TEMPS SHOULD BE ABLE TO RADIATE INTO THE MID/UPR 30S ACROSS THE REGION. SFC WINDS SHOULD CONTINUE OVERNIGHT AROUND 10 MPH OR LESS...HOWEVER SHOULD BE JUST ENOUGH TO PREVENT LARGE SCALE FOG DEVELOPMENT. A FEW PROTECTED AREAS AND LOCATIONS CLOSEST TO STREAMS...MAY SEE PATCHY FOG DEVELOP. THE OTHER AREAS THAT COULD SEE PATCHY FOG MAY BE THE FAR NORTHEAST CORNER OF NORTHEAST IL...WITH A WEAK ONSHORE FLOW AND MARINE MOISTURE BLEEDING INLAND A FEW MILES. CONFIDENCE...HIGH. MONDAY THROUGH TUESDAY... ANTI-CYCLONIC FLOW IS PROGGED TO BE THE MAIN FEATURE FOR EARLY WEEK...HOWEVER A WEAK FRONTAL BOUNDARY IS PROGGED TO PUSH EAST ACROSS THE MISSISSIPPI VALLEY INTO THE GREAT LAKES MONDAY NIGHT/EARLY TUESDAY. GUIDANCE HAS CONTINUED TO HINT THAT SOME MOISTURE WILL ACCOMPANY THIS BOUNDARY...ALTHOUGH LOOKING UPSTREAM AT CURRENT CONDITIONS IT APPEARS THE SCENARIO OF LIGHT PRECIP IS LOW FOR MONDAY NIGHT/EARLY TUE. ANOTHER POTENTIAL LIMITING FACTOR IS THAT THE EXPECTED DOWNSTREAM RIDGE MAY CONTINUE TO HOLD WITH DIFFLUENT FLOW IN THE MID-LVLS...WHICH WOULD AID IN DRYING THE MOISTURE AT THE MID-LVLS. LLVL FLOW MAY BACK SLIGHTLY TO THE SOUTHEAST...WHICH COULD ALSO AID IN MOISTURE AVAILABILITY. FORCING DOES NOT APPEAR TO BE VERY POTENT EITHER. MANY PLUMES SUGGEST A DRY MON NGT/EARLY TUE AS WELL ACROSS THE CWFA. BASED ON THESE AFOREMENTIONED ELEMENTS...HAVE OPTED TO REMOVE MENTION OF PRECIP ACROSS THE CWFA FOR MON NGT/EARLY TUE...AND ADJUSTED ANY PRECIP TO LOCATIONS FURTHER NORTH ACROSS WISC/LAKE MICHIGAN/LOWER MICHIGAN. IF PRECIP DOES DEVELOP...IT APPEARS IT MAY END UP BEING SPRINKLES. OVERALL EXPECT JUST CLOUDS TO BE ON THE INCREASE FROM THIS SYSTEM. TEMPS BOTH DAYS WILL CONTINUE TO BE MILD WITH A THERMAL RIDGE OF 5 TO 7 DEG C MONDAY...AND 6 TO 8 DEG C TUESDAY. WITH OPTIMAL CONDS EXPECTED BOTH DAYS...TEMPS SHOULD EASILY WARM INTO THE MID/UPR 50S. FOR LOCATIONS ALONG AND SOUTH OF I-80 TEMPS COULD TOUCH 60 DEGREES TUESDAY AFTERNOON. SEVERAL 2M TEMP PLUMES FOR THIS PERIOD ALSO SUPPORT THIS MAX TEMP FORECAST. OVERNIGHT LOWS WILL ALSO BE MILD...UPR 30S/LOW 40S. CONFIDENCE...HIGH. PRECIP CONFIDENCE...MEDIUM/HIGH. WEDNESDAY... ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR...AND IT APPEARS MOTHER NATURE WILL COOPERATE AND PRODUCE OPTIMAL TRAVEL CONDITIONS FOR NORTHERN IL/NORTHWEST IN. ANTI-CYCLONIC FLOW WILL PUSH BACK INTO THE REGION AND ERODE THE CLOUDS TUE NGT/EARLY WED...WITH COULD ALLOW TEMPS EARLY WED BEFORE SUNRISE TO DIP INTO THE LOW 30S. THEN A LARGE DIURNAL CURVE IS EXPECTED FOR WED AFTERNOON. 850MB THERMAL RIDGE OF 7 TO 9 DEG C IS PROGGED TO SLIDE OVERHEAD FROM THE WEST/SOUTHWEST...WITH LLVL FLOW TURNING SOUTH/SOUTHWEST. THE BEST PRESSURE GRADIENT AND ADVECTION APPEARS TO BE DISPLACED TO THE NORTHWEST/WEST OF THE CWFA...HOWEVER IT APPEARS TEMPS COULD EASILY WARM TO 60 DEG ACROSS THE AREA. FOR AREAS ALONG AND WEST OF A ROCKFORD/KANKAKEE LINE...TEMPS MAY PUSH TO 61 TO 63 DEG. CONFIDENCE...HIGH. THANKSGIVING THROUGH SATURDAY... THE ANOMALOUS WARM/DRY PATTERN THAT HAS DOMINATED MUCH OF THE REGION FOR THE PAST SEVERAL DAYS...MAY BE TRANSITIONING INTO A MORE ACTIVE PATTERN. ABOVE NORMAL 500MB HEIGHTS WILL PERSIST THROUGH THUR...THEN STEADILY WEAKEN INTO A SEMI-ZONAL FLOW AND POSSIBLY A TROUGH DIGGING INTO THE UPPER MIDWEST/CENTRAL ROCKIES DEVELOPS. GUIDANCE BECOMES RATHER NOISY IN THE EXTENDED PERIODS FROM FRI-SAT...WHICH IS INDICATED BY THE ENVELOPE OF SOLUTIONS THAT THE ENSEMBLES PROG AS WELL AS OPERATIONAL GFS/ECMWF. THE FIRST FEW PERIODS WILL CONTINUE TO BE MILD WITH TEMPS NEAR 60 TO POSSIBLY THE LOW 60S IN THE AFTERNOON FOR THANKSGIVING...HOWEVER THIS WILL CHANGE FOR FRI/SAT. 500MB TROUGH CONTINUES TO BE PROGGED BY OPERATIONAL SOLUTIONS AND ANTI-CYCLONIC FLOW WILL DEPART TO THE SOUTHEAST. THIS WILL AID IN A STRENGTHENING SOUTHWEST FLOW THUR NGT/FRI AS A FRONTAL BOUNDARY BEGINS TO APPROACH THE REGION. 850MB THERMAL TROUGH OF -2 TO -5 DEG C SHOULD ARRIVE ACROSS THE REGION MIDDAY FRI...THUS TEMPS FRI MAY STRUGGLE TO WARM WITH POSSIBLY THE WARMEST TEMPS FOR THE DAY OCCURRING IN THE MORNING. 500MB SPEED MAX PIVOTS EAST ACROSS THE UPPER MIDWEST/NORTHERN GREAT LAKES...HOWEVER APPEARS TO BE MAINLY MOISTURE STARVED. AT THIS POINT HAVE CONTINUED TO MENTION CHC POPS...AND TEMPS SHOULD BE COOL ENOUGH TO PRODUCE A POSSIBLE RA/SN MIX HOWEVER MOISTURE RAPIDLY PIVOTS NORTHEAST BY FRI AFTN/EVE THAT THIS WOULD BE RESTRICTED TO THE LAKE ENVIRONMENT AND LOWER MICHIGAN. THEN ANTI-CYCLONIC FLOW IS PROGGED TO BUILD BACK INTO THE MIDWEST/GREAT LAKES REGION FOR THE REMAINDER OF THE WEEKEND AND PROVIDE DRY WEATHER. IN ADDITION THE LONGER TERM MODELS CONTINUE TO HINT THAT TEMPS MAY YET AGAIN PUSH BACK ABOVE NORMAL FOR THE SECOND HALF OF THE WEEKEND AND POSSIBLY CONTINUE INTO EARLY THE FOLLOWING WEEK. CONFIDENCE...HIGH. BEACHLER && .CLIMATE... 321 AM CST A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY 1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER. NORMALS... CHICAGO ROCKFORD MAX MIN MAX MIN NOV 01 56 38 56 36 NOV 17 47 32 47 30 NOV 30 40 27 39 24 THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT: CHICAGO ROCKFORD NOV 21 72 1913 73 1913 NOV 22 69 1913 69 2010 TRS/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * WEAK LAKE BREEZE MOVING INLAND TO ORD VC 22-23Z TIME-FRAME BACKING WINDS SOMEWHAT FROM SSE TO SE FOR A PERIOD LATE AFTERNOON-EARLY EVENING. TRS //DISCUSSION...UPDATED 18Z... LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME. RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE. WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH POSSIBLE OCCASIONAL GUSTS OF 14-17KT. EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY SCT-BKN MID AND HIGH LEVEL CLOUDS. TRS //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN ORD WIND VEERING FM SSE TO SE DURING MID- LATE AFTERNOON DUE TO WEAK LAKE BREEZE MOVING INLAND ACROSS EXTREME NORTHEAST IL. * HIGH CONFIDENCE REMAINDER OF FCST. TRS //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z... MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN. TUESDAY AND WEDNESDAY...VFR. THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE. FRIDAY AND SATURDAY...VFR. LENNING && .MARINE... 225 PM CST A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM NOVA SCOTIA TO THE LOWER MISSISSIPPI VALLEY.. THE RIDGE IS EXPECTED TO ONLY DRIFT VERY SLOWLY EAST OVER THE NEXT SEVERAL DAYS WHILE GRADUALLY WEAKENING. A TROUGH OF LOW PRESSURE WILL MOVE INTO THE DAKOTAS TODAY...THEN INTO THE WESTERN GREAT LAKES MONDAY NIGHT AS IT WEAKENS SLIGHTLY. THIS WILL KEEP GENERALLY SOUTHERLY WINDS OVER THE LAKE UNTIL EARLY NEXT WEEK. AS THE TROUGH FURTHER WEAKENS TUESDAY NIGHT AND AN ASSOCIATED WEAK COLD FRONT CROSSES LAKE MICHIGAN... WINDS WILL SHIFT TO NORTHWESTERLY. HOWEVER...NO INCREASE IN WINDS IS LIKELY AS A WEAK RIDGE OF HIGH PRESSURE WILL IMMEDIATELY FILL IN BEHIND THE FRONT AND THERE IS NO SIGNIFICANTLY COLD AIR BEHIND THE FRONT. ANOTHER LOW IS FORECAST TO DEVELOP OVER MONTANA ON WEDNESDAY AND QUICKLY TRACK EASTWARD TO NEAR LAKE SUPERIOR BY THURSDAY EVENING. THE LOW WILL THEN TURN NORTHEAST TOWARD SOUTHERN JAMES BAY...DRAGGING A COLD FRONT ACROSS LAKE MICHIGAN LATE THURSDAY NIGHT OR FRIDAY MORNING. THIS FRONT IS EXPECTED TO BE MUCH STRONGER THAN THE PREVIOUS FRONT...BRINGING IN A MUCH COLDER INFLUX OF COLDER AIR...AND WILL BRING STRENGTHENING NORTHWESTERLY WINDS TO THE LAKE, KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
214 PM CST SUN NOV 18 2012 .DISCUSSION... 213 PM CST TONIGHT... ANTI-CYCLONIC FEATURE HAS BECOME STRETCHED OUT WITH A CENTER OVER SOUTHEAST QUEBEC AND CONTINUES TO PROVIDE A MAIN INFLUENCE ACROSS THE OHIO VALLEY/MID-MISSISSIPPI VALLEY. TO THE WEST OF THIS INFLUENCE ACROSS PORTIONS OF THE UPPER MIDWEST/CENTRAL PLAINS...THE PRESSURE GRADIENT IS TIGHTER AND RESULTING IN OCCASIONALLY GUSTY SOUTH WINDS IN THOSE AREAS. VISIBLE IMAGERY EARLY THIS AFTERNOON DEPICTS A CHANNEL OF CIRRUS CLOUDS FROM NORTHERN IL STRETCHING WEST THROUGH IOWA...THEN A MORE EXPANSIVE AREA OF CIRRUS CLOUDS ACROSS THE SOUTHERN PLAINS INTO THE SOUTHERN ROCKIES. THE SOUTHERN ROCKIES IS THE AREA THAT GUIDANCE HAS BEEN FOCUSED ON FOR THE DEVELOPMENT OF A WEAK WAVE THAT WILL SLIDE ALONG THE FRONTAL BOUNDARY AND OVERSPREAD CLOUDS AND LGT PRECIP TO PORTIONS OF THE GREAT LAKES MON NGT. CLOUD COVER WILL STEADILY SLIDE OVERHEAD THIS EVENING/OVERNIGHT...WITH A FEW POCKETS OF CLEARING. DEEPER MOISTURE WILL REMAIN WEST OF THE CWFA THROUGH THE OVERNIGHT...MAINLY OVER IA/MO/KS/OK. WITH POTENTIALLY HIGH CLOUDS OVERHEAD SFC TEMPS SHOULD BE ABLE TO RADIATE INTO THE MID/UPR 30S ACROSS THE REGION. SFC WINDS SHOULD CONTINUE OVERNIGHT AROUND 10 MPH OR LESS...HOWEVER SHOULD BE JUST ENOUGH TO PREVENT LARGE SCALE FOG DEVELOPMENT. A FEW PROTECTED AREAS AND LOCATIONS CLOSEST TO STREAMS...MAY SEE PATCHY FOG DEVELOP. THE OTHER AREAS THAT COULD SEE PATCHY FOG MAY BE THE FAR NORTHEAST CORNER OF NORTHEAST IL...WITH A WEAK ONSHORE FLOW AND MARINE MOISTURE BLEEDING INLAND A FEW MILES. CONFIDENCE...HIGH. MONDAY THROUGH TUESDAY... ANTI-CYCLONIC FLOW IS PROGGED TO BE THE MAIN FEATURE FOR EARLY WEEK...HOWEVER A WEAK FRONTAL BOUNDARY IS PROGGED TO PUSH EAST ACROSS THE MISSISSIPPI VALLEY INTO THE GREAT LAKES MONDAY NIGHT/EARLY TUESDAY. GUIDANCE HAS CONTINUED TO HINT THAT SOME MOISTURE WILL ACCOMPANY THIS BOUNDARY...ALTHOUGH LOOKING UPSTREAM AT CURRENT CONDITIONS IT APPEARS THE SCENARIO OF LIGHT PRECIP IS LOW FOR MONDAY NIGHT/EARLY TUE. ANOTHER POTENTIAL LIMITING FACTOR IS THAT THE EXPECTED DOWNSTREAM RIDGE MAY CONTINUE TO HOLD WITH DIFFLUENT FLOW IN THE MID-LVLS...WHICH WOULD AID IN DRYING THE MOISTURE AT THE MID-LVLS. LLVL FLOW MAY BACK SLIGHTLY TO THE SOUTHEAST...WHICH COULD ALSO AID IN MOISTURE AVAILABILITY. FORCING DOES NOT APPEAR TO BE VERY POTENT EITHER. MANY PLUMES SUGGEST A DRY MON NGT/EARLY TUE AS WELL ACROSS THE CWFA. BASED ON THESE AFOREMENTIONED ELEMENTS...HAVE OPTED TO REMOVE MENTION OF PRECIP ACROSS THE CWFA FOR MON NGT/EARLY TUE...AND ADJUSTED ANY PRECIP TO LOCATIONS FURTHER NORTH ACROSS WISC/LAKE MICHIGAN/LOWER MICHIGAN. IF PRECIP DOES DEVELOP...IT APPEARS IT MAY END UP BEING SPRINKLES. OVERALL EXPECT JUST CLOUDS TO BE ON THE INCREASE FROM THIS SYSTEM. TEMPS BOTH DAYS WILL CONTINUE TO BE MILD WITH A THERMAL RIDGE OF 5 TO 7 DEG C MONDAY...AND 6 TO 8 DEG C TUESDAY. WITH OPTIMAL CONDS EXPECTED BOTH DAYS...TEMPS SHOULD EASILY WARM INTO THE MID/UPR 50S. FOR LOCATIONS ALONG AND SOUTH OF I-80 TEMPS COULD TOUCH 60 DEGREES TUESDAY AFTERNOON. SEVERAL 2M TEMP PLUMES FOR THIS PERIOD ALSO SUPPORT THIS MAX TEMP FORECAST. OVERNIGHT LOWS WILL ALSO BE MILD...UPR 30S/LOW 40S. CONFIDENCE...HIGH. PRECIP CONFIDENCE...MEDIUM/HIGH. WEDNESDAY... ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR...AND IT APPEARS MOTHER NATURE WILL COOPERATE AND PRODUCE OPTIMAL TRAVEL CONDITIONS FOR NORTHERN IL/NORTHWEST IN. ANTI-CYCLONIC FLOW WILL PUSH BACK INTO THE REGION AND ERODE THE CLOUDS TUE NGT/EARLY WED...WITH COULD ALLOW TEMPS EARLY WED BEFORE SUNRISE TO DIP INTO THE LOW 30S. THEN A LARGE DIURNAL CURVE IS EXPECTED FOR WED AFTERNOON. 850MB THERMAL RIDGE OF 7 TO 9 DEG C IS PROGGED TO SLIDE OVERHEAD FROM THE WEST/SOUTHWEST...WITH LLVL FLOW TURNING SOUTH/SOUTHWEST. THE BEST PRESSURE GRADIENT AND ADVECTION APPEARS TO BE DISPLACED TO THE NORTHWEST/WEST OF THE CWFA...HOWEVER IT APPEARS TEMPS COULD EASILY WARM TO 60 DEG ACROSS THE AREA. FOR AREAS ALONG AND WEST OF A ROCKFORD/KANKAKEE LINE...TEMPS MAY PUSH TO 61 TO 63 DEG. CONFIDENCE...HIGH. THANKSGIVING THROUGH SATURDAY... THE ANOMALOUS WARM/DRY PATTERN THAT HAS DOMINATED MUCH OF THE REGION FOR THE PAST SEVERAL DAYS...MAY BE TRANSITIONING INTO A MORE ACTIVE PATTERN. ABOVE NORMAL 500MB HEIGHTS WILL PERSIST THROUGH THUR...THEN STEADILY WEAKEN INTO A SEMI-ZONAL FLOW AND POSSIBLY A TROUGH DIGGING INTO THE UPPER MIDWEST/CENTRAL ROCKIES DEVELOPS. GUIDANCE BECOMES RATHER NOISY IN THE EXTENDED PERIODS FROM FRI-SAT...WHICH IS INDICATED BY THE ENVELOPE OF SOLUTIONS THAT THE ENSEMBLES PROG AS WELL AS OPERATIONAL GFS/ECMWF. THE FIRST FEW PERIODS WILL CONTINUE TO BE MILD WITH TEMPS NEAR 60 TO POSSIBLY THE LOW 60S IN THE AFTERNOON FOR THANKSGIVING...HOWEVER THIS WILL CHANGE FOR FRI/SAT. 500MB TROUGH CONTINUES TO BE PROGGED BY OPERATIONAL SOLUTIONS AND ANTI-CYCLONIC FLOW WILL DEPART TO THE SOUTHEAST. THIS WILL AID IN A STRENGTHENING SOUTHWEST FLOW THUR NGT/FRI AS A FRONTAL BOUNDARY BEGINS TO APPROACH THE REGION. 850MB THERMAL TROUGH OF -2 TO -5 DEG C SHOULD ARRIVE ACROSS THE REGION MIDDAY FRI...THUS TEMPS FRI MAY STRUGGLE TO WARM WITH POSSIBLY THE WARMEST TEMPS FOR THE DAY OCCURRING IN THE MORNING. 500MB SPEED MAX PIVOTS EAST ACROSS THE UPPER MIDWEST/NORTHERN GREAT LAKES...HOWEVER APPEARS TO BE MAINLY MOISTURE STARVED. AT THIS POINT HAVE CONTINUED TO MENTION CHC POPS...AND TEMPS SHOULD BE COOL ENOUGH TO PRODUCE A POSSIBLE RA/SN MIX HOWEVER MOISTURE RAPIDLY PIVOTS NORTHEAST BY FRI AFTN/EVE THAT THIS WOULD BE RESTRICTED TO THE LAKE ENVIRONMENT AND LOWER MICHIGAN. THEN ANTI-CYCLONIC FLOW IS PROGGED TO BUILD BACK INTO THE MIDWEST/GREAT LAKES REGION FOR THE REMAINDER OF THE WEEKEND AND PROVIDE DRY WEATHER. IN ADDITION THE LONGER TERM MODELS CONTINUE TO HINT THAT TEMPS MAY YET AGAIN PUSH BACK ABOVE NORMAL FOR THE SECOND HALF OF THE WEEKEND AND POSSIBLY CONTINUE INTO EARLY THE FOLLOWING WEEK. CONFIDENCE...HIGH. BEACHLER && .CLIMATE... 321 AM CST A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY 1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER. NORMALS... CHICAGO ROCKFORD MAX MIN MAX MIN NOV 01 56 38 56 36 NOV 17 47 32 47 30 NOV 30 40 27 39 24 THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT: CHICAGO ROCKFORD NOV 21 72 1913 73 1913 NOV 22 69 1913 69 2010 TRS/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * WEAK LAKE BREEZE MOVING INLAND TO ORD VC 22-23Z TIME-FRAME BACKING WINDS SOMEWHAT FROM SSE TO SE FOR A PERIOD LATE AFTERNOON-EARLY EVENING. TRS //DISCUSSION...UPDATED 18Z... LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME. RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE. WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH POSSIBLE OCCASIONAL GUSTS OF 14-17KT. EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY SCT-BKN MID AND HIGH LEVEL CLOUDS. TRS //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN ORD WIND VEERING FM SSE TO SE DURING MID- LATE AFTERNOON DUE TO WEAK LAKE BREEZE MOVING INLAND ACROSS EXTREME NORTHEAST IL. * HIGH CONFIDENCE REMAINDER OF FCST. TRS //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z... MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN. TUESDAY AND WEDNESDAY...VFR. THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE. FRIDAY AND SATURDAY...VFR. LENNING && .MARINE... 249 AM CST A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK. THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER AWAY TOWARD THE ATLANTIC COAST. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
205 PM CST SUN NOV 18 2012 .DISCUSSION... 321 AM CST SYNOPSIS...SOME THINGS BECOME CLEARER WHILE OTHER PARTS OF THE FORECAST BECOME MORE MUDDLED. OVERALL A GRADUAL WARMING PATTERN IS STILL EXPECTED THROUGH MONDAY...WITH TEMPERATURES WELL ABOVE NORMAL WEDNESDAY AND THANKSGIVING. NO SIGNIFICANT PRECIP IS EXPECTED. TODAY THROUGH MONDAY... HIGH PRESSURE CURRENTLY CENTERED OVER SOUTHEASTERN QUEBEC/UPPER NEW ENGLAND STRETCHES THROUGH THE MISSISSIPPI RIVER VALLEY. THE HIGH WILL REMAINED CENTERED THERE THROUGH EARLY NEXT WEEK WITH RELATIVELY QUIET WEATHER EXPECTED LOCALLY. TEMPS WILL BE AROUND 60 TODAY WITH CLEAR SKIES AND SOUTHERLY FLOW. CLOUDS INCREASE TOMORROW AS A THROUGH OF LOW PRESSURE/WEAK COLD FRONT APPROACH FROM THE WEST. AS SUCH WENT WITH TEMPS A DEGREE OR TWO COOLER ON MONDAY...BUT STILL WELL ABOVE AVERAGE. MONDAY NIGHT AND TUESDAY... LOW PRESSURE CURRENTLY OVER WESTERN BRITISH COLUMBIA WILL PUSH EASTWARD THROUGH CANADA...AND MODELS CONTINUE TO PUSH THE LOW FURTHER NORTH. THE LOWS COLD FRONT/LOW PRESSURE TROUGH WILL PASS THROUGH THE AREA. FORCING REMAINS WEAK ALONG THE COLD FRONT THEREFORE EXPECTING A FEW HUNDREDTHS AT BEST MONDAY EVENING THROUGH MONDAY NIGHT. GUIDANCE INDICATES THE TROUGH/COLD FRONT WEAKENS AS IT APPROACHES THE CWA SO THE BEST CHANCE OF PRECIP LOOKS TO BE OVER THE WESTERN AND NORTHERN PORTIONS OF THE CWA MONDAY NIGHT. AND BY BEST CHANCE I MEAN BEST VERY VERY SLIGHT CHANCE. PRECIP MOVES OUT BY TUESDAY MORNING AND HIGH PRESSURE QUICKLY MOVES OVER THE CWA. THINKING TEMPS WILL ONCE AGAIN BE A DEGREE OR TWO HIGHER THAN MONDAY DUE TO WEAK UPPER LEVEL WAA AND CLEARING SKIES. WEDNESDAY AND THANKSGIVING... SOUTHERLY FLOW RETURNS IN FORCE WEDNESDAY AS THE HIGH PRESSURE SLIDES TOWARD THE SOUTHEAST US. 850 HPA TEMPS SOAR TO AROUND 10C WEDNESDAY AND THANKSGIVING...THEREFORE WENT A FEW DEGREES ABOVE ALL-BLEND GUIDANCE ONCE AGAIN. ITS LOOKING LIKE THURSDAY MAY BE THE WARMER OF THE TWO DAYS WITH TEMPS BOTH DAYS AT OR ABOVE 60 DEGREES. MOST PEOPLE WOULD AGREE THAT IS SOMETHING TO BE THANKFUL ABOUT. EXTENDED...THANKSGIVING NIGHT THROUGH SATURDAY... WHAT HAPPENS THANKSGIVING EVENING/NIGHT IS THE BIG FORECAST QUESTION. THE GEM AND ECMWF INDICATE LOW PRESSURE WILL MOVE FROM THE CENTRAL PLAINS THROUGH WISCONSIN WITH ITS COLD FRONT MOVING THROUGH THE CWA THANKSGIVING NIGHT. THE GFS ON THE OTHER HAND HAS THE LOW MOVING MUCH FARTHER NORTH OVER CENTRAL ONTARIO AND QUEBEC. THE GFS SOLUTION IS ALSO MUCH FASTER THAN THE OTHER TWO SOLUTIONS. SINCE THE GEM AND ECMWF ARE MERGING TOWARD EACH OTHER...LEANING TOWARD THAT SOLUTION. THERE ARE ENOUGH DIFFERENCES IN THE SOLUTIONS THAT DECIDED TO NOT MAKE ANY ADJUSTMENTS TO THE ALL-BLEND TEMPS OR SLIGHT CHANCE POP FORECAST. THAT BEING SAID...IF THE ECMWF SOLUTION IS TO BE BELIEVED...A SIGNIFICANT TEMPERATURE DROP WILL BE EXPECTED BETWEEN THANKSGIVING AND FRIDAY. BY FRIDAY AFTERNOON 850 HPA TEMPS ARE WELL BELOW ZERO. THE GFS FEATURES A MUCH WEAKER COLD AIR PUSH SINCE ITS UPPER LEVEL PATTERN IS VERY ZONAL. NONETHELESS IT DOES FEATURE 850 HPA TEMPS BELOW ZERO MOVING OVERHEAD SATURDAY. JEE && .CLIMATE... 321 AM CST A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY 1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER. NORMALS... CHICAGO ROCKFORD MAX MIN MAX MIN NOV 01 56 38 56 36 NOV 17 47 32 47 30 NOV 30 40 27 39 24 THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT: CHICAGO ROCKFORD NOV 21 72 1913 73 1913 NOV 22 69 1913 69 2010 TRS/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * WEAK LAKE BREEZE MOVING INLAND TO ORD VC 22-23Z TIME-FRAME BACKING WINDS SOMEWHAT FROM SSE TO SE FOR A PERIOD LATE AFTERNOON-EARLY EVENING. TRS //DISCUSSION...UPDATED 18Z... LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME. RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE. WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH POSSIBLE OCCASIONAL GUSTS OF 14-17KT. EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY SCT-BKN MID AND HIGH LEVEL CLOUDS. TRS //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN ORD WIND VEERING FM SSE TO SE DURING MID- LATE AFTERNOON DUE TO WEAK LAKE BREEZE MOVING INLAND ACROSS EXTREME NORTHEAST IL. * HIGH CONFIDENCE REMAINDER OF FCST. TRS //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z... MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN. TUESDAY AND WEDNESDAY...VFR. THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE. FRIDAY AND SATURDAY...VFR. LENNING && .MARINE... 249 AM CST A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK. THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER AWAY TOWARD THE ATLANTIC COAST. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1201 PM CST SUN NOV 18 2012 .DISCUSSION... 321 AM CST SYNOPSIS...SOME THINGS BECOME CLEARER WHILE OTHER PARTS OF THE FORECAST BECOME MORE MUDDLED. OVERALL A GRADUAL WARMING PATTERN IS STILL EXPECTED THROUGH MONDAY...WITH TEMPERATURES WELL ABOVE NORMAL WEDNESDAY AND THANKSGIVING. NO SIGNIFICANT PRECIP IS EXPECTED. TODAY THROUGH MONDAY... HIGH PRESSURE CURRENTLY CENTERED OVER SOUTHEASTERN QUEBEC/UPPER NEW ENGLAND STRETCHES THROUGH THE MISSISSIPPI RIVER VALLEY. THE HIGH WILL REMAINED CENTERED THERE THROUGH EARLY NEXT WEEK WITH RELATIVELY QUIET WEATHER EXPECTED LOCALLY. TEMPS WILL BE AROUND 60 TODAY WITH CLEAR SKIES AND SOUTHERLY FLOW. CLOUDS INCREASE TOMORROW AS A THROUGH OF LOW PRESSURE/WEAK COLD FRONT APPROACH FROM THE WEST. AS SUCH WENT WITH TEMPS A DEGREE OR TWO COOLER ON MONDAY...BUT STILL WELL ABOVE AVERAGE. MONDAY NIGHT AND TUESDAY... LOW PRESSURE CURRENTLY OVER WESTERN BRITISH COLUMBIA WILL PUSH EASTWARD THROUGH CANADA...AND MODELS CONTINUE TO PUSH THE LOW FURTHER NORTH. THE LOWS COLD FRONT/LOW PRESSURE TROUGH WILL PASS THROUGH THE AREA. FORCING REMAINS WEAK ALONG THE COLD FRONT THEREFORE EXPECTING A FEW HUNDREDTHS AT BEST MONDAY EVENING THROUGH MONDAY NIGHT. GUIDANCE INDICATES THE TROUGH/COLD FRONT WEAKENS AS IT APPROACHES THE CWA SO THE BEST CHANCE OF PRECIP LOOKS TO BE OVER THE WESTERN AND NORTHERN PORTIONS OF THE CWA MONDAY NIGHT. AND BY BEST CHANCE I MEAN BEST VERY VERY SLIGHT CHANCE. PRECIP MOVES OUT BY TUESDAY MORNING AND HIGH PRESSURE QUICKLY MOVES OVER THE CWA. THINKING TEMPS WILL ONCE AGAIN BE A DEGREE OR TWO HIGHER THAN MONDAY DUE TO WEAK UPPER LEVEL WAA AND CLEARING SKIES. WEDNESDAY AND THANKSGIVING... SOUTHERLY FLOW RETURNS IN FORCE WEDNESDAY AS THE HIGH PRESSURE SLIDES TOWARD THE SOUTHEAST US. 850 HPA TEMPS SOAR TO AROUND 10C WEDNESDAY AND THANKSGIVING...THEREFORE WENT A FEW DEGREES ABOVE ALL-BLEND GUIDANCE ONCE AGAIN. ITS LOOKING LIKE THURSDAY MAY BE THE WARMER OF THE TWO DAYS WITH TEMPS BOTH DAYS AT OR ABOVE 60 DEGREES. MOST PEOPLE WOULD AGREE THAT IS SOMETHING TO BE THANKFUL ABOUT. EXTENDED...THANKSGIVING NIGHT THROUGH SATURDAY... WHAT HAPPENS THANKSGIVING EVENING/NIGHT IS THE BIG FORECAST QUESTION. THE GEM AND ECMWF INDICATE LOW PRESSURE WILL MOVE FROM THE CENTRAL PLAINS THROUGH WISCONSIN WITH ITS COLD FRONT MOVING THROUGH THE CWA THANKSGIVING NIGHT. THE GFS ON THE OTHER HAND HAS THE LOW MOVING MUCH FARTHER NORTH OVER CENTRAL ONTARIO AND QUEBEC. THE GFS SOLUTION IS ALSO MUCH FASTER THAN THE OTHER TWO SOLUTIONS. SINCE THE GEM AND ECMWF ARE MERGING TOWARD EACH OTHER...LEANING TOWARD THAT SOLUTION. THERE ARE ENOUGH DIFFERENCES IN THE SOLUTIONS THAT DECIDED TO NOT MAKE ANY ADJUSTMENTS TO THE ALL-BLEND TEMPS OR SLIGHT CHANCE POP FORECAST. THAT BEING SAID...IF THE ECMWF SOLUTION IS TO BE BELIEVED...A SIGNIFICANT TEMPERATURE DROP WILL BE EXPECTED BETWEEN THANKSGIVING AND FRIDAY. BY FRIDAY AFTERNOON 850 HPA TEMPS ARE WELL BELOW ZERO. THE GFS FEATURES A MUCH WEAKER COLD AIR PUSH SINCE ITS UPPER LEVEL PATTERN IS VERY ZONAL. NONETHELESS IT DOES FEATURE 850 HPA TEMPS BELOW ZERO MOVING OVERHEAD SATURDAY. JEE && .CLIMATE... 321 AM CST A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY 1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER. NORMALS... CHICAGO ROCKFORD MAX MIN MAX MIN NOV 01 56 38 56 36 NOV 17 47 32 47 30 NOV 30 40 27 39 24 THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT: CHICAGO ROCKFORD NOV 21 72 1913 73 1913 NOV 22 69 1913 69 2010 TRS/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * WEAK LAKE BREEZE MOVING INLAND TO MDW AND ORD VC 21-22Z TIME-FRAME BACKING WINDS SOMEWHAT FROM SSE TO SE. TRS //DISCUSSION...UPDATED 18Z... LATEST HI RES RUC AND HRR MODEL OUTPUT CONTINUE TO SUGGEST A WEAK LAKE BREEZE...SUCH AS OCCURRED FRI AND SAT...IS TO DEVELOP AND EVENTUALLY MOVE INLAND TO MDW AND ORD VICINITY 21-22Z TIME-FRAME. RESULT IS THAT 5-10 KT SSE WINDS BACK A BIT TO SE-ESE FOR THE LATE AFTERNOON. MARINE OBS SITES CURRENTLY SHOW A SE WIND DIRECTION AT WAUKEGAN AND BURNHAM HARBORS WITH MESONET OBS INDICATING LIGHT VARIABLE WINDS FROM JUST ASHORE TO A COUPLE MILES INLAND SUGGESTING THE WEAK BOUNDARY IS ALONG THE SHORE AND LITTLE RESISTANCE TO MOVING GRADUALLY INLAND AS CURRENT SMALL TEMPERATURE DIFFERENTIAL BETWEEN LAND AND WATER CONTINUES TO INCREASE. WITH LOSS OF HEATING TOWARDS DUSK AND DISSIPATION OF LAKE BREEZE EARLY IN THE EVENING WINDS TO RETURN TO SSE-S. SPEEDS TO BE LESS THAN 10 KT AS STRONGER SSW FLOW AHEAD OF AN APPROACHING COLD FRONT/SURFACE TROUGH MOVING EAST ACROSS THE NORTHERN AND CENTRAL PLAINS WILL BE DECOUPLED FROM THE SURFACE DURING THE NIGHT. AFTER SUNRISE MONDAY MORNING STRONG...SHALLOW INVERSION WILL BEGIN TO BE ERODED THOUGH WINDS AT TOP OF BOUNDARY LAYER DURING LATER MORNING AND AFTERNOON ARE ONLY 14-17KT. EXPECT SOUTHERLY SURFACE WINDS TO AVERAGE 8-10 KT AFTER SOME SURFACE HEATING AND MIXING WITH POSSIBLE OCCASIONAL GUSTS OF 14-17KT. EXPECT VFR CONDITIONS THROUGHOUT THE VALID TAFOR PERIOD WITH ONLY SCT-BKN MID AND HIGH LEVEL CLOUDS. TRS //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM CONFIDENCE ON WIND VEERING FM SSE TO SE AND ESE DURING MID AFTERNOON DUE TO WEAK LAKE BREEZE MOVING INLAND. * HIGH CONFIDENCE REMAINDER OF FCST. TRS //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z... MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN. TUESDAY AND WEDNESDAY...VFR. THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE. FRIDAY AND SATURDAY...VFR. LENNING && .MARINE... 249 AM CST A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK. THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER AWAY TOWARD THE ATLANTIC COAST. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CST SUN NOV 18 2012 .DISCUSSION... ISSUED 1045 AM CST SUN NOV 18 2012 FORECAST LOOKS ON TRACK AGAIN TODAY WITH YET ANOTHER NICE FALL DAY UNFOLDING. MAIN UPDATE IS FOR QUICKER RISE IN THE HOURLY TEMPS THIS MORNING INTO MIDDAY. AMPLE SUNSHINE TODAY AS THIN CIRRUS CLOUDS SPREAD EAST INTO CENTRAL IL. HIGHS IN THE UPPER 50S AND LOWER 60S WITH SSE WINDS 5 TO 10 MPH. LATE MORNING SURFACE MAP SHOWS STRONG 1041 MB HIGH PRESSURE OVER NEW ENGLAND AND RIDGING SW INTO THE MID MS VALLEY. ALOFT AN UPPER LEVEL TROF WAS ALONG THE WEST COAST WTIH UPPER LEVEL RIDGE OVER THE OH/TN VALLEYS WHICH PLACES IL IN A SW FLOW ALOFT. LIGHT FOG/HAZE DISSIPATE BY MID MORNING LEAVING SUNNY SKIES THIS MORNING. TEMPS WERE IN THE UPPER 40S AND LOWER 50S AT 1030 AM WITH SSE WINDS NEAR 8 MPH OR LESS. DEWPOINTS WERE IN THE MIDDLE 30S. MODELS SLOWLY WEAKEN HIGH PRESSURE RIDGE INTO MON AS IT STAYS OVER NEW ENGLAND AND RIDGES SW INTO THE MID MS VALLEY...KEEPING FAIR WEATHER OVER CENTRAL/SE IL. CIRRUS CLOUDS OVER IA AND MORE SCATTERED OVER MO/IL TO GRADUALLY INCREASE OVER CENTRAL IL THROUGH TONIGHT AND LEAD TO BROKEN CIRRUS CLOUDS LATER THIS EVENING. RUC... NAM AND HRRR HAS HIGHS IN THE MID TO UPPER 50S BY MID AFTERNOON ...BUT WENT A FEW DEGREES ABOVE THAT IN THE UPPER 50S AND LOWER 60S SINCE CURRENT TEMPS ARE RUNNING A FEW DEGREES AHEAD OF GUIDANCE. 07 && .AVIATION... ISSUED 532 AM CST SUN NOV 18 2012 QUIET/PREDOMINANTLY VFR AVIATION WEATHER CONDITIONS EXPECTED ACROSS THE CENTRAL ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME. THIS MORNING WILL BE ANOTHER MORNING WITH PATCHY MVFR FOG FOR A COUPLE HOURS...ALTHOUGH THE AREAL COVERAGE OF THE FOG SHOULD BE LESS THAN THE PAST COUPLE OF DAYS. AN APPROACHING UPPER LEVEL DISTURBANCE WILL SPREAD CIRRUS CIGS ACROSS THE TERMINALS BY LATE TONIGHT...BUT CIGS WILL BE WELL INTO THE VFR CATEGORY. THESE CIGS AND SOUTHERLY WINDS STAYING A BIT STRONGER AT NIGHT SHOULD PRECLUDE FOG REDEVELOPMENT LATER TONIGHT. BAK && .PREV DISCUSSION... ISSUED 250 AM CST SUN NOV 18 2012 CURRENT WEATHER PATTERN NOT MUCH DIFFERENT THAN 24 HRS AGO...WITH AN UPPER LOW OVER THE EXTREME SERN US...AND HIGH PRESSURE RIDGE FROM SERN CANADA TO THE CENTRAL GULF COAST. SFC WINDS IN THE OVERNIGHT LIGHTER...BUT PREDOMINANTLY OUT OF THE S/SE AS THE SUN COMES UP. FORECAST IS ESSENTIALLY ONE OF TEMPERATURES. TWO WAVES ARE PROGGED TO MOVE THROUGH THE QUASI ZONAL FLOW...MON/MON NIGHT...AND AGAIN LATER IN THE WEEK...BUT THE MODELS ARE SKETCHY WITH CONSISTENCY...AND THE ATMOSPHERE WILL BE STRUGGLING TO PRODUCE MOISTURE. AS A RESULT...THE ZONE FORECAST IS RUNNING DRY AT THE MOMENT. TEMPERATURES RUNNING ABOVE NORMAL THROUGH MIDWEEK. SHORT TERM...TODAY AND TOMORROW... RATHER QUIET WEATHER AND S/SERLY WINDS AT THE SFC WITH HIGH PRESSURE RIDGE OVER THE EASTERN HALF OF THE COUNTRY. MILD TEMPS CONTINUE...APPROACHING LOW 60S FOR MUCH OF THE AREA. MOSTLY SUNNY SKIES...AND CLEAR OVERNIGHT WILL COUNTER THE SOUTHERLY FLOW WITH RATHER EFFECTIVE RADIATIONAL COOLING AND TEMPS DROPPING INTO THE UPPER 30S AND NEAR 40. SOUTHERLY WINDS PICK UP A BIT ON MONDAY...AND A BROAD AREA OF WAA PUSHES UNSEASONABLE HEAT INTO THE SW AND CENTRAL PORTIONS OF THE COUNTRY. TEMPS MONDAY A BIT AHEAD OF GUIDANCE...AS THE SLOW WARMING TREND CONTINUES ACROSS THE MIDWEST. LONG TERM...TUESDAY THROUGH SATURDAY... HIGH PRESSURE RIDGE SLOWLY DRIFTS EASTWARD AND THE CLOSED UPPER LOW KICKS OUT OF THE SE. A SHORT WAVE RIPPLES THROUGH THE UPPER ATMOSPHERE...BRINGING A CHANCE FOR SHOWERS MON/MON NIGHT. AND THOUGH THE GFS AND THE NAM ARE BOTH PORTRAYING SOME QPF FOR THE REGION...KEEPING THE POPS RELATIVELY LOW...IN THE SLIGHT CHANCE CAT...AND LACK OF COVERAGE POTENTIAL IF NOTHING ELSE. MOISTURE IS SOMEWHAT LACKING THROUGH THE LAYER AHEAD OF THE SYSTEM. SOUTHERLY WINDS PRIOR TO MONDAY NOT PROVIDING MUCH MOISTURE TRANSPORT INTO THE AREA. WINDS START TO PICK UP A BIT ON MON WITH AN APPROACHING STORM SYSTEM...BUT STILL NOT MUCH IN EXCESS OF 10 KTS. MODELS HAVING A BIT OF AN ISSUE WITH THE WAVE ITSELF...WITH THE ECMWF HOLDING BACK A BIT AND PASSING A MORE VIGOROUS PIECE OF ENERGY LATER ON TUESDAY...ALBEIT A BIT OF AN OUTLIER. WILL WATCH CAREFULLY. ON THE OTHER SIDE OF THE CHANCES FOR SHOWERS MON...THE WARMING TREND CONTINUES THROUGH MID WEEK. 850MB TEMPS AT 6-7C WILL HAVE THE POTENTIAL TO TRANSLATE INTO UPPER 50S/LOWER 60S. GUIDANCE HAS NOT COMPLETELY LATCHED ONTO THE WARMING TREND...THOUGH THE MODEL FIELDS CLEARLY SHOW THE THERMAL RIDGE IN THE WESTERN CONUS DEEPENING AND SLOWLY CREEPING INTO THE MIDWEST. HAVE BUMPED MAX TEMPS A FEW DEGREES AHEAD OF ALLBLEND FOR MON- WED...AND A BIT ON THURSDAY. THURSDAY MAY BE COMPLICATED BY AN APPROACHING STORM SYSTEM AND ASSOCIATED CLOUD COVER...BUT SYSTEM STILL HAS A BIT OF UNCERTAINTY AND WOULD ALSO HAVE THE SAME PROBLEM AS MONDAYS WAVE WITH SCANT MOISTURE. KEEPING THE POPS LOW AND THE TEMPS A COUPLE OF DEGREES ABOVE GUIDANCE...BUT MODERATE FOR NOW. HJS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1003 AM CST SUN NOV 18 2012 .DISCUSSION... 321 AM CST SYNOPSIS...SOME THINGS BECOME CLEARER WHILE OTHER PARTS OF THE FORECAST BECOME MORE MUDDLED. OVERALL A GRADUAL WARMING PATTERN IS STILL EXPECTED THROUGH MONDAY...WITH TEMPERATURES WELL ABOVE NORMAL WEDNESDAY AND THANKSGIVING. NO SIGNIFICANT PRECIP IS EXPECTED. TODAY THROUGH MONDAY... HIGH PRESSURE CURRENTLY CENTERED OVER SOUTHEASTERN QUEBEC/UPPER NEW ENGLAND STRETCHES THROUGH THE MISSISSIPPI RIVER VALLEY. THE HIGH WILL REMAINED CENTERED THERE THROUGH EARLY NEXT WEEK WITH RELATIVELY QUIET WEATHER EXPECTED LOCALLY. TEMPS WILL BE AROUND 60 TODAY WITH CLEAR SKIES AND SOUTHERLY FLOW. CLOUDS INCREASE TOMORROW AS A THROUGH OF LOW PRESSURE/WEAK COLD FRONT APPROACH FROM THE WEST. AS SUCH WENT WITH TEMPS A DEGREE OR TWO COOLER ON MONDAY...BUT STILL WELL ABOVE AVERAGE. MONDAY NIGHT AND TUESDAY... LOW PRESSURE CURRENTLY OVER WESTERN BRITISH COLUMBIA WILL PUSH EASTWARD THROUGH CANADA...AND MODELS CONTINUE TO PUSH THE LOW FURTHER NORTH. THE LOWS COLD FRONT/LOW PRESSURE TROUGH WILL PASS THROUGH THE AREA. FORCING REMAINS WEAK ALONG THE COLD FRONT THEREFORE EXPECTING A FEW HUNDREDTHS AT BEST MONDAY EVENING THROUGH MONDAY NIGHT. GUIDANCE INDICATES THE TROUGH/COLD FRONT WEAKENS AS IT APPROACHES THE CWA SO THE BEST CHANCE OF PRECIP LOOKS TO BE OVER THE WESTERN AND NORTHERN PORTIONS OF THE CWA MONDAY NIGHT. AND BY BEST CHANCE I MEAN BEST VERY VERY SLIGHT CHANCE. PRECIP MOVES OUT BY TUESDAY MORNING AND HIGH PRESSURE QUICKLY MOVES OVER THE CWA. THINKING TEMPS WILL ONCE AGAIN BE A DEGREE OR TWO HIGHER THAN MONDAY DUE TO WEAK UPPER LEVEL WAA AND CLEARING SKIES. WEDNESDAY AND THANKSGIVING... SOUTHERLY FLOW RETURNS IN FORCE WEDNESDAY AS THE HIGH PRESSURE SLIDES TOWARD THE SOUTHEAST US. 850 HPA TEMPS SOAR TO AROUND 10C WEDNESDAY AND THANKSGIVING...THEREFORE WENT A FEW DEGREES ABOVE ALL-BLEND GUIDANCE ONCE AGAIN. ITS LOOKING LIKE THURSDAY MAY BE THE WARMER OF THE TWO DAYS WITH TEMPS BOTH DAYS AT OR ABOVE 60 DEGREES. MOST PEOPLE WOULD AGREE THAT IS SOMETHING TO BE THANKFUL ABOUT. EXTENDED...THANKSGIVING NIGHT THROUGH SATURDAY... WHAT HAPPENS THANKSGIVING EVENING/NIGHT IS THE BIG FORECAST QUESTION. THE GEM AND ECMWF INDICATE LOW PRESSURE WILL MOVE FROM THE CENTRAL PLAINS THROUGH WISCONSIN WITH ITS COLD FRONT MOVING THROUGH THE CWA THANKSGIVING NIGHT. THE GFS ON THE OTHER HAND HAS THE LOW MOVING MUCH FARTHER NORTH OVER CENTRAL ONTARIO AND QUEBEC. THE GFS SOLUTION IS ALSO MUCH FASTER THAN THE OTHER TWO SOLUTIONS. SINCE THE GEM AND ECMWF ARE MERGING TOWARD EACH OTHER...LEANING TOWARD THAT SOLUTION. THERE ARE ENOUGH DIFFERENCES IN THE SOLUTIONS THAT DECIDED TO NOT MAKE ANY ADJUSTMENTS TO THE ALL-BLEND TEMPS OR SLIGHT CHANCE POP FORECAST. THAT BEING SAID...IF THE ECMWF SOLUTION IS TO BE BELIEVED...A SIGNIFICANT TEMPERATURE DROP WILL BE EXPECTED BETWEEN THANKSGIVING AND FRIDAY. BY FRIDAY AFTERNOON 850 HPA TEMPS ARE WELL BELOW ZERO. THE GFS FEATURES A MUCH WEAKER COLD AIR PUSH SINCE ITS UPPER LEVEL PATTERN IS VERY ZONAL. NONETHELESS IT DOES FEATURE 850 HPA TEMPS BELOW ZERO MOVING OVERHEAD SATURDAY. JEE && .CLIMATE... 321 AM CST A SHIFT IN THE UPPER PATTERN WILL ALLOW SOME MODERATION OF TEMPERATURES GOING INTO THE WEEKEND AND PREVAILING FOR SEVERAL DAYS THEREAFTER. WHILE THE MODERATION WILL HELP OBSERVED TEMPERATURES TO EXCEED DAILY NORMALS THE FACT THAT INCREASINGLY SHORTER DAYS AND LOWERING SUN ANGLES RESULT IN THE NORMAL HIGH TEMPERATURE FALLING BY 1 DEGREE F ABOUT EVERY 2 DAYS. SO...IT IS THE COMBINATION OF THE LOWERING NORMAL MAXIMUM TEMPERATURES ALONG WITH THE WARMING THAT WILL RESULT IN DAYTIME TEMPERATURES TO CLIMB TO ABOVE NORMAL...WHICH ARE NOW ONLY IN THE UPPER 40S AT MID NOVEMBER. NORMALS... CHICAGO ROCKFORD MAX MIN MAX MIN NOV 01 56 38 56 36 NOV 17 47 32 47 30 NOV 30 40 27 39 24 THIS UNUSUAL PATTERN WILL ALSO ALLOW HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY...THANSKGIVING...TO COME CLOSE TO THE RECORD HIGH TEMPERATURES. WHILE FORECASTED HIGH TEMPERATURES ARE CURRENTLY A FEW DEGREES COOLER THAN THE RECORDS...HERE ARE THE THE MAX TEMPERATURE RECORDS FOR FOOD FOR THOUGHT: CHICAGO ROCKFORD NOV 21 72 1913 73 1913 NOV 22 69 1913 69 2010 TRS/JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * LAKE BREEZE MOVING INLAND TO MDW AND ORD VC 21-22Z TIME-FRAME. TRS //DISCUSSION...UPDATED 14Z... LATEST RUC AND HRR MODEL OUTPUT SUGGESTING A WEAK LAKE BREEZE... SUCH AS OCCURRED FRI AND SAT...DEVELOPING AND MOVING INLAND TO MDW AND ORD VC 21-22Z TIME-FRAME. WINDS EXPECTED TO BECOME A BIT MORE SOUTHERLY LATE MORNING AND EARLY AFTERNOON AND THE BACKING TO SE-ESE THERE TERMINALS FOR LATE AFTERNOON INTO EARLY EVE. TRS PREVIOUS...UPDATED 12Z... HIGH PRESSURE PARKED OVER THE EASTERN UNITED STATES WILL MAINTAIN HIGH CLOUDS AND RELATIVELY LIGHT SOUTH TO SOUTHEASTERLY WINDS OVER THE LOCAL TERMINALS. ALTHOUGH LATEST ASOS OBS AT ISSUANCE TIME WERE SHOWING CALM WINDS...OPTED TO KEEP A SSE DIRECTION AND 5 KTS IN THE TAFS TO HELP CRAFT A PLAN TO START OF THE DAY. THIS ALSO MATCHES THE WINDS REPORTED ELSEWHERE AROUND ORD AS RELAYED BY THE CWSU. DID NOT ATTEMPT TO PIN DOWN GUSTS OR MINOR VARIATIONS IN DIRECTION THAT COULD OCCUR THROUGHOUT THE DAY...THOUGH THERE IS A CHANCE THAT WINDS COULD TURN FARTHER TO THE EAST IN RESPONSE TO A LAKE BREEZE INFLUENCE. LENNING //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM CONFIDENCE ON WIND VEERING FM SSE TO SE AND ESE DURING MID AFTERNOON WITH WEAK LAKE BREEZE MOVING INLAND. * HIGH CONFIDENCE REMAINDER OF FCST. TRS //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED12Z... MONDAY NIGHT...VFR WITH SLIGHT CHANCE OF LIGHT RAIN. TUESDAY AND WEDNESDAY...VFR. THANKSGIVING...VFR WITH A CHANCE OF SHOWERS LATE. FRIDAY AND SATURDAY...VFR. LENNING && .MARINE... 249 AM CST A BROAD RIDGE ACROSS THE NORTHEASTERN UNITED STATES WILL WEAKEN SOMEWHAT BUT MOVE VERY LITTLE THROUGH THE FIRST HALF OF THE WEEK. THE LOCATION OF THIS FEATURE WILL SUPPORT CONTINUED SOUTHERLY FLOW ACROSS THE LAKE. THE LACK OF A STRONG PRESSURE GRADIENT WILL GENERALLY KEEP WINDS AND WAVES BELOW LEVELS THAT WOULD POSE HAZARDS. THE EXCEPTION WOULD BE ALONG THE FAR NORTHERN SHORE AT THE END OF THE LONG FETCH WHERE SMALL CRAFT HEADLINES ARE IN EFFECT. EVEN THE APPROACH OF A TROUGH FROM THE WEST TOWARD MIDWEEK WILL NOT BE ENOUGH TO BOOST WINDS...SINCE BY THAT TIME THE RIDGE TO THE EAST WILL HAVE WEAKENED SOMEWHAT AND MOVED A BIT FARTHER AWAY TOWARD THE ATLANTIC COAST. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1008 AM MST SUN NOV 18 2012 .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 145 AM MST SUN NOV 18 2012 SUMMARY...DRY WEATHER WITH ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE SHORT TERM PART OF FORECAST. TODAY...DEW POINT DEPRESSIONS CONTINUE TO LOWER EARLY THIS MORNING. LATEST FOG PRODUCT SATELLITE IMAGERY DOES NOT SHOW ANY EVIDENCE OF FOG FORMATION YET...BUT WITH LIGHT SURFACE WINDS...EXPECT SOME PATCHY FOG TO DEVELOP SHORTLY BEFORE SUNRISE MAINLY ALONG HIGHWAY 83. LATEST HRRR MODEL SUPPORTS THIS. OTHERWISE...A WEAK SHORTWAVE TROUGH WILL MOVE ACROSS THE FORECAST AREA DURING THE DAY...BUT RAOBS/MODELS CONTINUE TO SHOW THAT THE AIR MASS WILL BE DRY. ONLY MID AND HIGH LEVEL CLOUDS WILL ADVECT ACROSS THE AREA THIS AFTERNOON. LEE SIDE SURFACE TROUGH WILL MOVE EAST THIS AFTERNOON AND WILL SWITCH WINDS TO THE WEST ALONG THE COLORADO/KANSAS BORDER. WITH LACK OF AIR MASS CHANGE...EXPECT TEMPERATURES TO BE SIMILAR TO THOSE THAT OCCURRED SATURDAY. TONIGHT...500 MB FLOW BECOMES INCREASINGLY ZONAL BEGINNING TONIGHT. MODELS SHOW WEAK COLD AIR ADVECTION AT THE SURFACE STARTING AROUND 12Z. MONDAY...DRY ZONAL MID LEVEL FLOW WILL CONTINUE. SURFACE WINDS WILL BE NORTH BEHIND A PUSH OF SLIGHTLY COOLER AIR. ALTHOUGH 850 MB TEMPERATURES COOL...THE COOLING IS VERY SLIGHT...ONLY ABOUT 1 DEGREE CELSIUS. ONCE AGAIN...PERSISTENCE TEMPERATURE FORECASTS LOOK DECENT. MONDAY NIGHT THROUGH TUESDAY NIGHT...500 MB RIDGE AND ASSOCIATED SUBSIDENCE WILL DEVELOP OVER THE HIGH PLAINS. LEE SIDE TROUGH WILL REFORM BY TUESDAY AFTERNOON BRINGING A RETURN OF SOUTH WINDS AND WEAK WARM AIR ADVECTION. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 145 AM MST SUN NOV 18 2012 VERY LITTLE HAS CHANGED IN THE EXTENDED PERIODS WITH MODELS STILL ADVERTISING PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK ALONG US/CANADA BORDER. THERE ARE A FEW WEAK SHORTWAVE TROUGHS THAT COME CLOSE TO THE CWA...HOWEVER WITH A DEEP DRY LAYER IN PLACE THE MOST WE WOULD EXPECT TO SEE IS AN INCREASE IN MID-HIGH CLOUDS. RH VALUES STILL LOOK TO BE NEAR RFW CRITERIA WEDNESDAY AFTERNOON...HOWEVER SURFACE GRADIENT IS WEAK OVER THE CWA AND WINDS SHOULD BE WELL BELOW CRITERIA. OVERALL...STILL EXPECTING ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS TO CONTINUE. WED HIGHS WILL APPROACH 70F...WITH HIGHS IN THE UPPER 50S/NEAR 60F THROUGH THE REMAINING PERIODS AFTER A WEAK COLD FRONT MOVES THROUGH THE REGION WED NIGHT/THU. OVERNIGHT LOWS SHOULD BE IN THE LOW TO MID 30S EACH NIGHT...WHICH IS IS STILL ABOUT 10F ABOVE NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1006 AM MST SUN NOV 18 2012 VFR CONDITIONS ANTICIPATED AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. HIGH CLOUDS WILL GRADUALLY MOVE EAST THROUGH THE REST OF TODAY. LIGHT WESTERLY SURFACE WINDS TONIGHT WILL PREVENT FOG FORMATION...THOUGH WILL NEED TO MONITOR KMCK FOR PATCHY FOG IN THE REPUBLICAN RIVER VALLEY AROUND SUNRISE MONDAY MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...MENTZER SHORT TERM...MENTZER LONG TERM...DR AVIATION...024
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
332 PM CST Sun Nov 18 2012 .DISCUSSION... Tonight - Monday: The main challenges through this period are the timing/onset of precipitation and the duration into the Monday period. Water vapor imagery was showing the weak upper level disturbance moving out of the Southern Rockies and into the Plains. Radar and visible/IR imagery show what also may be a weak baroclinic zone across south central to eastern Nebraska with a few light returns showing up on radar. The GFS does indicate a slightly tighter theta-e gradient aloft through this area. The radar returns are consistent with the latest HRRR run, albeit a few hours delayed, which develops precipitation in this area this afternoon. Precipitation should increase in coverage across the eastern half of Kansas this evening as the support from the upper wave moves into the region. Think that the timing of precipitation in our western zones will be in the 2-3Z window and persist for 4-6 hours as the whole area moves into our eastern zones. It still looks like coverage will be in the 50% range and precipitation totals will be less than a quarter inch for those that do pick up rain. Precipitation still looks to be coming to end by mid day Monday. There could potentially be a few sprinkles Monday afternoon as another weak wave will be tracking into the area. But models are in good agreement moving any QPF away from the area during the afternoon so the chances of precipitation look too small to mention at this time. High temperatures on Monday will be restrained a bit in our eastern zones as cloud cover will be exiting the area preventing a warm up like our western zones are expected to see. Overall, highs will range from the low to mid 60s in our west to the middle 50s in our east. Tuesday - Tuesday Night: Quiet weather with above normal temperatures are expected this period. High temperatures should climb into the 60s across the area but may be inhibited by weak flow and limited mixing. Overnight lows should be mild for this time of year with lows generally in the low to mid 40s. With light winds overnight, some of our typical low lying/ drainage areas may fall into the 30s. CDB Wednesday - Sunday: Model consensus is a continuation of near to above average temperatures during this period with little in the way of precipitation. Travel day on Wednesday looks outstanding with temperatures nearing the 70 degree mark possible in the far western CWA. Most of the focus is on Thursday/Thanksgiving. An upper level ridge will exit the region on Wednesday as another impulse within the southern stream lifts northeast from the Southern Rockies on Thanksgiving. Despite a lack of low level moisture there is increasing support from the GFS and ECMWF that sufficient mid level Pacific moisture will be available for scattered light showers as a weak cold front drops southeast through MO Thursday night. Have nudged Thursday night pops up to chance category for the far southern counties. A large vortex over the Gulf of Alaska is expected to eject a significant piece of energy eastward at the start of the period. The resulting shortwave trough will dig/deepen southeast through the Upper MS Valley and Great Lakes Thursday night/Friday. Any weather with this feature will track to the north but a secondary cold front will pass through on Friday and reinforce an intrusion of colder air. Have gone along with model consensus on temperatures but the trend is towards more cooling and can envision later forecasts tweaking Friday`s temperatures downward some more. Zonal flow through the mid levels and warm air advection in the boundary layer will return for the dry weekend. MJ && .AVIATION... For the 18Z TAFs, VFR conditions are likely to occur throughout the valid period. The one exception will be for a few hours tonight as an upper level disturbance tracks across the region. As it does, widely scattered to scattered rain showers are possible at the terminals. This system will not have a lot of moisture to work with and the system itself is rather weak. So the result is a higher probability for VFR conditions as the wave is tracking through than sub-VFR conditions. During any showers, ceilings may fall to around 4 to 5 thousand feet and the shower intensity should not be strong enough to restrict visibilities. Outside of the rain chances tonight, winds will be rather strong and gusty from the south this afternoon before diminishing some tonight. Winds will also increase again from the south to southwest by late tomorrow morning or by noon but do not look to be as strong as this afternoon. CDB && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
305 PM CST SUN NOV 18 2012 .SHORT TERM...THROUGH MONDAY AFTERNOON. OVERALL THE BENIGN WEATHER PATTERN OF LATE CONTINUES THROUGH THE NEXT 24 HOURS...WITH THE MAIN FAIRLY MINOR ISSUE CONSISTING OF THE POSSIBILITY OF SPRINKLES ACROSS SOUTHEAST ZONES LATE THIS AFTERNOON INTO THIS EVENING. 20Z OBJECTIVE SURFACE ANALYSIS PLACES A GENERALLY NORTH-SOUTH TROUGH AXIS RUNNING FROM WESTERN SD THROUGH THE NEB PANHANDLE AND DOWN ALONG THE KS/CO BORDER...TRAILING SOUTH FROM A 1005MB LOW AT THE WY/MT/SD INTERSECTION. MEANWHILE...AN EXPANSIVE RIDGE AXIS CONTINUES TO DOMINATE MUCH OF THE EASTERN CONUS. THE CWA LIES ALONG THE INTERFACE BETWEEN THESE TWO FEATURES...WITH A MODEST PRESSURE GRADIENT AND DIURNAL MIXING GENERALLY INTO THE 900-875MB RANGE DRIVING SOUTHERLY SUSTAINED BREEZES TYPICALLY 13-23 MPH WITH GUSTS MAINLY 20-25 MPH. VISIBLE SATELLITE CONFIRMS A RATHER HEALTHY COVERAGE OF MID-HIGH CLOUDS STREAMING OVERHEAD...ESPECIALLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. RADAR EVEN SUGGESTS A FEW SPRINKLES MAY HAVE ALREADY FALLEN THIS AFTERNOON ACROSS PARTS OF NUCKOLLS/THAYER/FILLMORE COUNTIES. THESE CLOUDS SEEM TO BE HAVING A VARYING EFFECT ON TEMPS THIS AFTERNOON...WITH BOTH KS ZONES AND NORTHERN ZONES IN NEB VERY MUCH ON TRACK TO NEAR FORECAST HIGHS IN THE LOW-MID 60S...WHILE CENTRAL AREAS INCLUDING THE TRI-CITIES MAY FALL A BIT SHORT AND STRUGGLE TO REACH 60. THE CLOUDS HAVE LIKELY ALSO REDUCED MIXING SOMEWHAT AND HELD DOWN WIND SPEEDS SLIGHTLY. WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA DEPICTS BROAD QUASI-ZONAL/SLIGHTLY SOUTHWESTERLY FLOW ACROSS THE CENTRAL/WESTERN CONUS...WITH A PAIR OF FAIRLY VIGOROUS SHORTWAVE TROUGHS TRANSLATING THROUGH THE NORTHERN ROCKIES AND OFF THE PACIFIC NORTHWEST COAST. CLOSER TO HOME...A MORE SUBTLE LOW AMPLITUDE MID LEVEL WAVE IS CURRENTLY LIFTING OUT OF CO/WY...INTO NEB/KS...WITH THE MID-HIGH CLOUDS STREAMING OUT AHEAD OF THIS WAVE LARGELY ASSOCIATED WITH A MODEST 70+KT 300MB JET STREAK. LATE THIS AFTERNOON INTO THIS EVENING...THIS LOW AMPLITUDE MID LEVEL WAVE WILL CONTINUE TRACKING ACROSS THE HEART OF THE CENTRAL PLAINS...WITH THE ONGOING BATCH OF MID-HIGH CLOUDS GRADUALLY CLEARING THE CWA FROM WEST-EAST AND PAVING THE WAY FOR A CLEAR OVERNIGHT. PRIOR TO THIS HOWEVER...THE MOISTURE-STARVED DISTURBANCE WILL CONTINUE TO PROMOTE MODEST THETA-E ADVECTION EVIDENT IN THE 850-700MB LAYER MAINLY OVER THE EASTERN HALVES OF NEB/KS. DESPITE PLENTIFUL DRY AIR ESPECIALLY BELOW 700MB...WILL MAINTAIN A CHANCE OF SPRINKLES THROUGH 10 PM FOR LOCATIONS GENERALLY EAST OF A LINE FROM YORK-NELSON-OSBORNE...WITH ESSENTIALLY ZERO RISK OF PRECIP ACROSS THE REMAINDER OF THE CWA. DESPITE VARIOUS MODELS SUCH AS THE NAM/ECMWF/GFS KEEPING ALL QPF EAST OF THE CWA INTO THIS EVENING...THE WEAK RADAR RETURNS ALREADY OBSERVED WITHIN THE FAR SOUTHEAST CWA THIS AFTERNOON ALONG WITH THE 1KM REFLECTIVITY PROGS FROM THE LATEST HRRR MAKE ME UNWILLING TO COMPLETELY IGNORE SPRINKLE POTENTIAL...ALTHOUGH AGREE WITH PREVIOUS FORECASTER THAT ANYTHING MEASURABLE SHOULD FOCUS WELL EAST/SOUTHEAST OF THE LOCAL AREA. AS MENTIONED...THE OVERNIGHT WILL FEATURE CLEAR SKIES...WHILE AT THE SURFACE...A WEAK TROUGH WILL MOVE EASTWARD ACROSS MAINLY THE WESTERN 1/2 OF THE CWA...TURNING LIGHT BREEZES NORTHWESTERLY IN ITS WAKE. TEMPS OVERNIGHT COULD BE A BIT TRICKY...AS THE NORTHWEST COMPONENT BEHIND THE SURFACE TROUGH COULD ACT TO HOLD THINGS UP...WHILE JUST AHEAD OF THE TROUGH THE COMBINATION OF NEAR-CALM TO LIGHT SOUTHERLY BREEZES AND CLEAR SKIES SHOULD PROMOTE AN EFFICIENT DROP. FEEL THAT A BLEND OF 12Z MET/MAV GUIDANCE IS PROBABLY THE BEST COMPROMISE...AND THUS WILL LOWER MOST OF THE CWA 2-3 DEGREES FROM PREVIOUS FORECAST...BUT STILL KEEPING ALL BUT A FEW NORTHWEST COUNTIES ABOVE FREEZING AND IN THE 33-37 RANGE. ALTHOUGH SUPPOSE SOME HAZE OR LIGHT FOG IS NOT OUT OF THE QUESTION AROUND SUNRISE ESPECIALLY ALONG THE TROUGH AXIS...AM NOT EXPECTING FOG TO BE WORTHY OF A FORMAL MENTION IN THE FORECAST. FOR THE MONDAY DAYTIME PERIOD...TRANQUIL...MOISTURE-STARVED QUASI- ZONAL FLOW WILL CONTINUE ALOFT OVER THE CENTRAL PLAINS...AS THE SHORTWAVE CURRENTLY AFFECTING THE AREA MOVES WELL OFF EAST TOWARD THE GREAT LAKES...WHILE THE SOUTHERN FRINGES OF ANOTHER MID LEVEL WAVE CENTERED OVER THE CANADIAN BORDER BRUSHES INTO WESTERN NEB DURING THE AFTERNOON. WHILE THE MAJORITY OF THE DAY SHOULD REMAIN QUITE SUNNY WITH ONLY A FEW PASSING SPLOTCHES OF HIGH CIRRUS...THE MID-LATE AFTERNOON HOURS COULD FEATURE A BIT GREATER INCOMING CIRRUS COVERAGE MAINLY OVER NORTHWEST ZONES ASSOCIATED WITH THE APPROACHING SHORTWAVE TROUGH. AT THE SURFACE...THE TROUGH AXIS ESSENTIALLY BISECTING THE AREA AT SUNRISE WILL CONTINUE PUSHING SOUTHEAST THROUGH THE DAY. IN ITS WAKE...FAIRLY LIGHT BREEZES OF ONLY AROUND 10 MPH FROM THE NORTH-NORTHWEST WILL PREVAIL. THESE LIGHT WINDS WILL MAKE FOR PLEASANT CONDITIONS THANKS TO THE NEXT IN A LONG STRETCH OF SEASONABLY WARM DAYS. MADE VERY LITTLE CHANGE TO HIGH TEMPS...AND IF ANYTHING NUDGED SOME PLACES UP ANOTHER DEGREE...AIMING FOR LOW 60S NORTHEAST...MID 60S CENTRAL INCLUDING TRI-CITIES...AND UPPER 60S KS ZONES. THE OVERALL BIGGEST CHANGE TO THE MONDAY GRIDS WAS TO DEWPOINTS...WHICH WERE LOWERED 4-7 DEGREES...WITH VALUES ONLY EXPECTED TO AVERAGE IN THE LOW-MID 30S IN MOST AREAS. EVEN SO...RELATIVE HUMIDITY VALUES SHOULD STILL DROP NO LOWER THAN THE UPPER 20S...KEEPING FIRE DANGER QUITE LOW THANKS TO THE LIGHT WINDS. .LONG TERM...STARTING 00Z TUESDAY. GUIDANCE FROM THE OPERATIONAL GFS...GEFS-MEAN AND EC ALL CONTINUE TO SUGGEST MID AND UPPER LEVEL JET ENERGY WILL REMAIN TO THE NORTH OF THE CENTRAL PLAINS THROUGH THE LONG TERM FORECAST PERIOD. A MID LEVEL SHORT WAVE IS EXPECTED TO PUSH ACROSS SOUTHERN CANADA AND THE NORTHERN PLAINS DURING THE DAY THURSDAY...ALONG WITH A WEAK MID LEVEL PERTURBATION WHICH IS EXPECTED PUSH ACROSS THE SOUTHERN PLAINS ALSO ON THURSDAY. ALTHOUGH THESE MID LEVEL DISTURBANCES WILL REMAIN NORTH AND SOUTH OF OUR REGION...AN ASSOCIATED LOW LEVEL BAROCLINIC ZONE IS EXPECTED TO PUSH ACROSS OUR AREA DURING THE DAY THURSDAY. THE OPERATIONAL GFS AND EC BOTH CONTINUE TO SUGGEST LOW LEVEL CONVERGENCE AND RESULTANT FORCING WILL REMAIN WEAK ALONG THIS BAROCLINIC ZONE. ALTHOUGH THERE COULD BE AN INCREASE IN MID TO HIGH LEVEL CLOUDS AS THE MID LEVEL PERTURBATION PUSHES ACROSS THE SOUTHERN PLAINS...AN OVERALL LACK IN KINEMATIC FORCING SHOULD KEEP OUR AREA DRY THROUGHOUT THE LONG TERM FORECAST PERIOD. LITTLE CHANGE IN THE LOW LEVEL AIRMASS TUESDAY THROUGH THURSDAY WILL PRESENT SIMILAR TEMPERATURES EACH DAY...WITH HIGHS GENERALLY IN THE 60S AND LOWS IN THE 30S AND 40S...WHICH IS WELL ABOVE NORMAL FOR THIS TIME OF YEAR. WEAK LOW LEVEL COLD AIR ADVECTION POST FROPA BEGINNING THURSDAY NIGHT WILL THEN PRESENT SOMEWHAT COOLER WEATHER TO FINISH OUT THE WEEK...WITH HIGHS GENERALLY IN THE 50S AND LOWS IN THE 30S...STILL ABOVE NORMAL FOR THIS TIME OF YEAR. && .PREV DISCUSSION... /ISSUED 1116 AM CST SUN NOV 18 2012/ AVIATION...18Z KGRI TAF. VFR CONDITIONS ARE EXPECTED. SURFACE LOW PRESSURE ALONG THE FRONT RANGE OF THE ROCKIES THIS AFTERNOON WILL GRADUALLY SHIFT EASTWARD THROUGHOUT THE TAF PERIOD. AHEAD OF THIS SYSTEM...STRONG SOUTH WINDS WILL CONTINUE WITH WIND SPEEDS NEAR 15 TO 20 MILES PER HOUR. HIGH CIRRUS CAN ALSO BE EXPECTED THROUGHOUT MUCH OF THE DAY...WITH DECREASING CLOUDS AND WIND SPEEDS TOWARDS THE OVERNIGHT HOURS. THE MAIN TROUGH AXIS WILL BEGIN TO SHIFT ACROSS THE REGION AROUND 6Z TO 8Z...WITH WINDS EXPECTED TO SHIFT TO THE WEST NORTHWEST BEHIND THE TROUGH. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...BRYANT AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1121 AM CST SUN NOV 18 2012 .SHORT TERM...THROUGH TUESDAY NIGHT 212 AM CST SUN NOV 18 2012 MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TONIGHT INTO MONDAY AS WELL AS TEMPERATURES THROUGHOUT. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP TROUGH FROM JUST OFF THE COAST OF BRITISH COLUMBIA INTO THE PACIFIC NORTHWEST...AND SOUTHWEST FLOW FROM THE DESERT SOUTHWEST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION. WITHIN THIS SOUTHWEST FLOW...SHORTWAVES OF NOTE ARE ALONG THE UTAH/COLORADO BORDER AND IN NORTHWEST MINNESOTA. DPVA AHEAD OF THIS LATTER SHORTWAVE COMBINED WITH 295-300K ISENTROPIC LIFT PRODUCED SHOWERS ACROSS NORTHEAST MINNESOTA. THE 295K ISENTROPIC LIFT ALSO EXTENDED SOUTHWEST FROM NORTHEAST MINNESOTA INTO CENTRAL IOWA...AND ALONG THIS ZONE IS A BAND OF STRATUS WITH CEILINGS BETWEEN 6000-9000 FT. THE BAND OF STRATUS ALSO SEPARATES MOIST AIR FROM VERY DRY AIR AT 850MB. FOR EXAMPLE...FROM 00Z SOUNDINGS...THE 850MB DEWPOINT AT DVN WAS -20C WHILE IT WAS -2C AT MPX AND 1C AT OAX. THE BROAD SOUTHWEST FLOW ALOFT HAS RESULTED IN A WARM ADVECTION PATTERN ACROSS THE UPPER MIDWEST. 850MB TEMPS WERE +6C AT MPX AND OAX AT 00Z. THE LOW LEVEL SOUTHERLY FLOW WAS FAIRLY STRONG WITH 925MB PROFILER AND VWP DATA SHOWING SPEEDS OF 35-45KT AROUND THE FORECAST AREA. THESE WINDS ARE HOLDING TEMPERATURES UP FROM THE MID 30S TO MID 40S...WARMEST IN SOUTHEAST MINNESOTA. TODAY AND TONIGHT...FOCUS IS ON THAT SHORTWAVE ALONG THE UTAH/COLORADO BORDER. GOOD MODEL AGREEMENT REMAINS ON THIS SHORTWAVE LIFTING UP THROUGH THE SOUTHWEST FLOW AND MOVING INTO WESTERN PORTIONS OF THE FORECAST AREA BY 12Z MONDAY. BRIEF RIDGING DEVELOPS OVER THE FORECAST AREA TODAY DOWNSTREAM OF THIS SHORTWAVE...WHICH SHOULD ACT TO CLEAR THE CLOUDS UP SOMEWHAT. WITH THE RELATIVELY SPEAKING WARM START...SUNSHINE AND 925MB TEMPS AROUND 6C WHICH ARE SIMILAR TO YESTERDAY...ANTICIPATING HIGHS TO BE FAIRLY SIMILAR TO A FEW DEGREES WARMER THAN YESTERDAY. FOR TONIGHT...THE 850MB MOISTURE STREAM CURRENTLY OVER WESTERN MINNESOTA AND IOWA WILL GET PUSHED EAST INTO THE FORECAST AREA BY THE SHORTWAVE. THE MAIN QUESTION IS IF DPVA AND ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE WILL BE STRONG ENOUGH TO ACT ON THIS MOISTURE AND PRODUCE PRECIPITATION. MID CLOUD DEVELOPMENT IS A CERTAINTY...GIVEN WHAT HAPPENED LAST EVENING ON THE LEADING EDGE OF THE 850MB MOISTURE STREAM. THE 18.00Z NAM/REGIONAL CANADIAN PAINT A DRY PICTURE AND EVEN THE GFS WHICH LOOKS TO HAVE A BIT TOO MUCH MOISTURE COMPARED TO ALL OTHER MODELS PRODUCES LITTLE IF ANY PRECIPITATION BEFORE 12Z. THE 17.12Z ECMWF MEANWHILE REMAINS MOST ROBUST WITH 0.1-0.2 OF AN INCH OVER NORTHEAST IOWA BETWEEN 06-12Z MONDAY. NEW 18.00Z ECMWF IS SLIGHTLY DRIER. SREF TRENDS HAVE SHOWN LESS MEMBERS PRODUCING 0.01 OF AN INCH OVER THE LAST 5 RUNS...DOWN FROM 40-50 PERCENT TO 10-30 PERCENT. AT THIS POINT...CANNOT SEE GOING WITH THE MORE ROBUST ECMWF SOLUTION AND HAVE KEPT CHANCES LOW IN THE 20-30 PERCENT RANGE...CENTERED IN THE 09-12Z PERIOD. WITH THE INCREASING CLOUDS AND A SOUTHERLY BREEZE BEING MAINTAINED...A SLIGHTLY WARMER NIGHT THAN TONIGHT IS ANTICIPATED. MONDAY AND MONDAY NIGHT...THE SHORTWAVE OVER WESTERN PORTIONS OF THE FORECAST AREA AT 12Z LOOKS TO MOVE THROUGH THE REST OF THE FORECAST AREA BY EARLY AFTERNOON...WHILE THE TAIL END OF THE DEEP TROUGHING IN THE PACIFIC NORTHWEST IS PROGGED TO DROP DOWN INTO THE FORECAST AREA AFTER MIDNIGHT MONDAY NIGHT. THIS LATTER SHORTWAVE WILL COME THROUGH DRY SINCE THE SHORTWAVE COMING THROUGH MONDAY MORNING ENDS UP SCOURING OUT A LOT OF THE MOISTURE. THUS ALL FOCUS IS ON THE MONDAY MORNING PERIOD. AGAIN HERE...MODELS ARE AT ODDS WITH FORCING AND MOISTURE AVAILABILITY. THE 18.00Z NAM/REGIONAL CANADIAN SAYS THERE IS TOO MUCH DRY AIR BELOW 800MB AND THE FORCING IS TOO WEAK ABOVE IT TO ALLOW FOR PRECIPITATION TO MAKE IT TO THE SURFACE. ON THE OTHER HAND...THE 18.00Z GFS AND 17.12Z/18.00Z ECMWF ARE MORE ROBUST IN BOTH ARENAS AND END UP PRODUCING LIGHT QPF ACROSS MUCH OF THE AREA. SREF TRENDS FOR THE FULL DAY MONDAY ARE ALSO SIMILAR TO 06-12Z MONDAY...SHOWING A DECLINE OF MEMBERS PRODUCING AT LEAST 0.01 OF AN INCH. IT USED TO BE UP AT 70-80 PERCENT BUT NOW IS DOWN TO 30-60 PERCENT. THUS...CONFIDENCE REMAINS TOO LOW TO ADJUST THE PREVIOUS FORECAST PRECIPITATION CHANCES OF 20-40 PERCENT. CERTAINLY IF ANY PRECIPITATION OCCURS...ANY RAIN LOOKS REALLY LIGHT. REGARDING CLOUD COVER...IT NOW APPEARS THAT THE SHORTWAVE ON MONDAY MORNING SHOULD HELP TO CLEAR THE CLOUDS OUT AS IT MOVES AWAY DURING THE AFTERNOON. THERE MAY BE AN INCREASE OF CIRRUS WITH THE SHORTWAVE COMING IN MONDAY NIGHT...BUT THATS ABOUT IT. NOTE THAT THERE IS CONCERN FOR A LOW CLOUD DECK BASED ON THE GFS/ECMWF 925MB RH PROGS...BUT THEY MAY BE TOO MOIST. FOR NOW TAKING A COMPROMISE APPROACH BY SPEEDING UP THE CLEARING SOME FROM THE PREVIOUS FORECAST. HAVING MORE CLOUDS MONDAY WILL HOLD THE TEMPERATURES DOWN A FEW DEGREES FROM HIGHS OVER THE WEEKEND. A COOLER NIGHT SEEMS LIKELY TOO FOR MONDAY NIGHT...ESPECIALLY IF THE CLEARING OCCURS. TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THAT SHORTWAVE DROPPING INTO THE FORECAST AREA TUESDAY MORNING...SOME FAIRLY STRONG RIDGING IS PROGGED TO BUILD INTO THE FORECAST AREA BY TUESDAY EVENING. ABOUT ALL THAT SHORTWAVE IS GOING TO DO IS PREVENT THE 850MB TEMP CLIMB...NOTED BY 850MB TEMPS AT 18Z TUESDAY OF 5-7C. ONCE THE RIDGING STARTS BUILDING IN...THESE TEMPS CLIMB...TOPPING OUT AT 8C EAST TO 11C WEST BY 12Z WEDNESDAY. WITH WHAT SHOULD BE PLENTY OF SUN...HIGHS SHOULD BE ABLE TO TOP OUT IN THE 50S AGAIN ON TUESDAY GIVEN THE AFOREMENTIONED 850MB TEMPS. INCREASING SOUTHERLY FLOW TUESDAY NIGHT IN THE WAKE OF HIGH PRESSURE THAT CROSSES THE AREA ON TUESDAY WILL HELP TO KEEP TEMPERATURES UP IN SOUTHEAST MINNESOTA. FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT 212 AM CST SUN NOV 18 2012 MAIN FOCUS CONTINUES TO BE ON A POTENT SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST WEDNESDAY MORNING. MODEL AGREEMENT HANDLING THIS POTENT TROUGH BEGINS TO DECLINE AS EARLY AS 12Z THURSDAY...WITH THE 18.00Z ECMWF/CANADIAN SHOWING A DIGGING NATURE TO IT INTO THE NORTHERN PLAINS. MEANWHILE...THE 18.00Z GFS TAKES A MORE PROGRESSIVE APPROACH AND SENDS IT UP INTO NORTHERN ONTARIO ON THURSDAY. BOTH THE GFS AND ECMWF HAVE COMPLETELY FLIPPED FROM PREVIOUS RUNS WITH THE HANDLING OF THIS POTENT TROUGH. THE 18.00Z ECMWF LOOKS MORE LIKE THE 17.00Z GFS WHILE THE 18.00Z GFS LOOKS MORE LIKE THE 16.12Z ECMWF. THIS HAS SIGNIFICANT IMPLICATIONS ON THE TEMPERATURE AND WIND FORECASTS...PRIMARILY FRIDAY AND BEYOND. WITH THE MORE DIGGING NATURE OF THE ECMWF/CANADIAN...THEY END UP CARVING OUT A DEEP TROUGH ACROSS THE WESTERN GREAT LAKES REGION FOR FRIDAY...THOUGH WITHIN THIS GROUP THE CANADIAN IS MORE PROGRESSIVE. WHICHEVER MODEL SCENARIO PLAYS OUT...IT APPEARS DRY WEATHER WOULD BE THE RULE WITH THE BEST JUXTAPOSITION OF FORCING AND MOISTURE EITHER NORTH OR SOUTHEAST OF THE AREA. GIVEN THE DIFFERENCES EARLY IN THE LONG TERM PERIOD...HARD TO SAY HOW THE WEEKEND WILL PLAY ITSELF OUT. NOTE THAT THE 18.00Z GFS ENSEMBLES HAVE A PRETTY GOOD SPREAD TOO WITH REGARDS TO THE POTENT TROUGH. THUS FOR NOW HAVE STAYED WITH A CONSENSUS APPROACH WHEN IT COMES TO THE WEEKEND...YIELDING COOLER AND A CONTINUATION OF DRY CONDITIONS. REGARDING TEMPERATURES...WEDNESDAY AND THANKSGIVING DAY STILL LOOK WELL ABOVE NORMAL...ESPECIALLY WEDNESDAY AS 925MB TEMPS CLIMB TO 10-12C FOR 18Z. MIXING TO 925MB YIELDS HIGHS FROM THE UPPER 50S TO MIDDLE 60S...THUS HAVE BOOSTED HIGHS A FEW DEGREES. RECORD HIGHS FOR WEDNESDAY ARE 72 AT LA CROSSE AND 69 AT ROCHESTER...STILL 5-10 DEGREES ABOVE THE GOING FORECAST. NOTE THAT 850MB TEMP STANDARDIZED ANOMALIES HAVE NOW JUMPED TO NEAR 2...SUPPORTING THE INCREASING IN HIGH TEMPERATURES. SOME COOLING IN 925MB TEMPS TAKES PLACE ON THANKSGIVING DAY AS A COLD FRONT MOVES INTO THE REGION. STILL...MOST LOCATIONS SHOULD TOP OUT AT LEAST IN THE MID TO UPPER 50S...MAYBE EVEN 60 AT SOME SOUTH OF I-90. RECORD HIGH FOR THURSDAY IS 59 AT LA CROSSE AND 65 AT ROCHESTER...THUS LA CROSSE MAY BE DOABLE TO BREAK. TEMPERATURES SHOULD RETURN CLOSER TO NORMAL FOR FRIDAY INTO THE WEEKEND IN THE WAKE OF THE COLD FRONT. IF THE 18.00Z ECMWF IS CORRECT...WE COULD EVEN BE BELOW NORMAL FOR THE WEEKEND. && .AVIATION...THROUGH 18Z MONDAY 1121 AM CST SUN NOV 18 2012 WILL BE WATCHING A MID-LEVEL TROUGH OF LOW PRESSURE AND SURFACE COLD FRONT APPROACH THE AREA FROM THE PLAINS LATE TONIGHT...AND THEN ACROSS THE AREA ON MONDAY. THIS WILL SPREAD CLOUDS INTO THE UPPER MISSISSIPPI RIVER REGION TONIGHT AND THEN PRODUCE SCATTERED -SHRA ACROSS PORTIONS OF SOUTHEAST MN/NORTHEAST IA INTO SOUTHWEST WISCONSIN TOWARD MORNING. EXPECTING SCATTERED -SHRA TO REMAIN EAST OF KRST BUT DID INCLUDE A VCSH MENTION AT KLSE AFTER 11Z SINCE THIS IS WHERE BETTER SURGE OF MOISTURE TRANSPORT WILL EXIST. PLAN ON VFR CONDITIONS THROUGH THE PERIOD WITH CIGS EXPECTED TO REMAIN AOA 4500 FT AGL. && .ARX WATCHES/WARNINGS/ADVISORIES... 212 AM CST SUN NOV 18 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS