Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/04/12


AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1245 AM EDT TUE OCT 2 2012 .SYNOPSIS... HIGH PRESSURE WILL EXTEND FROM THE WATERS OFF THE MIDDLE ATLANTIC COAST TO THE GREAT LAKES TONIGHT. ON TUESDAY THE HIGH WILL GIVE WAY TO LOW PRESSURE MOVING NORTH INTO THE OHIO VALLY WITH AN ASSOCIATED WARM FRONT MOVING NORTH INTO THE MID-ATLANTIC REGION ON TUESDAY AND TUESDAY NIGHT. THE WARM FRONT IS EXPECTED TO LIFT THROUGH OUR REGION ON WEDNESDAY FOLLOWED BY A FRONTAL BOUNDARY FROM THE WEST LATE ON WEDNESDAY NIGHT. HIGH PRESSURE IS FORECAST TO AFFECT OUR REGION ON THURSDAY. A COLD FRONT FROM THE NORTHWEST IS ANTICIPATED TO ARRIVE ON FRIDAY NIGHT WITH ANOTHER COLD FRONT EXPECTED FOR SUNDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... SPRINKLES OR LIGHT RAIN SHOWERS FALLING PREDOMINATELY FROM A MID DECK CROSSING PORTIONS OF EASTERN PENNSYLVANIA AND CENTRAL NEW JERSEY LATE THIS EVENING. THE PRECIPITATION IS NOT MAKING MUCH PROGRESS NORTHEAST YET...AS THE 0000 UTC OKX SOUNDING SHOWED A PRONOUNCED DRY LAYER ABOVE THE SURFACE. THE DRY LAYER WILL FILL IN AS THE LOW TO MID LEVEL WARM AIR ADVECTION WORKS ITS WAY NORTHEAST INTO THE NORTHERN ZONES. THE 0000 UTC IAD SOUNDING WAS MOISTURE THROUGH THE COLUMN ABOVE 5000 FEET...AND THE MOISTURE RIDING NORTH SHOULD CONTINUE TO PRODUCE LIGHT RAIN SHOWERS THROUGH THE NIGHT. SOUNDINGS IN THE AIR WERE STABLE IN THE DEVELOPING PRE WARM FRONTAL AIRMASS. IN FACT...SOUNDINGS UPSTREAM DOWN THROUGH WESTERN NORTH CAROLINA WERE STABLE (BUT MOIST)...SO DEEPER CONVECTIVE LIKE SHOWERS MAY NOT GET THIS FAR NORTH UNTIL LATER TONIGHT (AT THE EARLIEST). OTHERWISE...THE CLOUDS ARE IN PLACE AND WILL CONTINUE TO LOWER OVERNIGHT. THE LATEST HRRR DOES NOT SHOW THE NEXT LARGER BATCH OF SHOWERS REACHING SOUTHWEST AREAS UNTIL ALMOST DAYBREAK. BASED ON THE ABOVE...THE CHANCE OF SHOWERS WAS RAISED LATE THIS EVENING TO ACCOUNT FOR THE ONGOING SHOWERS...THEN HELD STEADY UNTIL LATE. TEMPERATURES PROBABLY DO NOT CHANGE MUCH OVERNIGHT. THE EXCEPTION COULD BE PORTIONS OF NORTHEAST MARYLAND AND CENTRAL AND SOUTHERN DELAWARE. AS THE LOW LEVEL DEW POINTS INCREASE...THE SURFACE TEMPERATURES MAY EDGE UP TOWARD SUNRISE. WINDS SHOULD BACK TO EAST TO NORTHEAST AHEAD OF THE WARM FRONT...BUT REMAIN LESS THAN 10 MPH. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TONIGHT/... THE WARM FRONT ATTACHED TO WEAKENING LOW PRESSURE (WELL TO THE WEST) WILL BE ACROSS THE AREA ON TUESDAY. THE MOISTURE ASSOCIATED WITH THE SYSTEM WILL INCREASE ACROSS THE AREA TUE MORNING AND REMAIN INTO THE AFTERNOON. CHC POPS ACROSS THE REGION WILL INCREASE TO THE LOW LIKELY RANGE BY AFTERNOON. QPF OF .10 TO .25 INCHES EXPECTED. HIGH TEMPERATURES ON TUE WITH THE ABUNDANT CLOUD COVER SHOULD HOLD IN THE UPPER 60S NORTH...LOW TO MID 70S IN MOST OTHER AREAS. THERE IS A POSSIBILITY FOR MORE BREAKS IN THE CLOUDS ACROSS THE DELMARVA...SO WE ARE INDICATING SOME UPPER 70S AND LOW 80S THERE. WINDS WILL BE LIGHT FROM THE E OR SE. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... ON TUESDAY NIGHT, THE MID LEVEL PATTERN IS FORECAST TO FEATURE A LOW OVER THE MIDDLE MISSISSIPPI RIVER VALLEY, A HIGH OVER THE WESTERN NORTH ATLANTIC AND A STRONG SOUTHERLY FLOW FROM THE GULF OF MEXICO UP TO THE EASTERN GREAT LAKES AND THE NORTHEAST. THE LOW IS FORECAST TO LIFT NORTHEASTWARD, MOVING ACROSS LOWER MICHIGAN AND INTO EASTERN ONTARIO ON WEDNESDAY NIGHT AS IT BECOMES AN OPEN WAVE. THE FEATURE IS ANTICIPATED TO CONTINUE UP OVER QUEBEC AND IT IS EXPECTED TO PULL A SHORT WAVE TROUGH ACROSS OUR REGION ON THURSDAY AFTERNOON. THE MAIN PLUME OF MOISTURE BEING DRAWN UP FROM THE SOUTH IS EXPECTED TO REMAIN ALONG AND JUST OFF THE COAST DURING TUESDAY NIGHT AND WEDNESDAY. PRECIPITABLE WATER VALUES IN EXCESS OF TWO INCHES SHOULD NUDGE INTO OUR REGION AT THAT TIME. MEANWHILE, THE BETTER DYNAMICS ASSOCIATED WITH THE PATTERN WILL LIKELY REMAIN WELL TO OUR WEST. AS A RESULT, IT SHOULD BE A HUMID AND UNSETTLED PERIOD FROM TUESDAY NIGHT INTO WEDNESDAY WITH NO PARTICULAR FOCUS TO TRIGGER WIDESPREAD MODERATE TO HEAVY RAINFALL. AT THE SURFACE, A WARM FRONT IS FORECAST TO REMAIN EITHER ACROSS OUR FAR SOUTHERN COUNTIES OR JUST TO OUR SOUTH FOR MUCH OF TUESDAY NIGHT. AS A RESULT, WE ARE ANTICIPATING SOME LIGHT RAIN AND DRIZZLE IN MUCH OF OUR REGION. WE HAVE INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS NEAR THE FRONTAL BOUNDARY. THE WARM FRONT IS EXPECTED TO LIFT GRADUALLY THROUGH OUR REGION ON WEDNESDAY. WE SHOULD TRANSITION FROM LOW CLOUDS AND LIGHT RAIN AND DRIZZLE TO SCATTERED SHOWERS AND THUNDERSTORMS FOR THE AFTERNOON WHEN MUCH OF OUR REGION IS EXPECTED TO BECOME AT LEAST MARGINALLY UNSTABLE. A WEAK SURFACE BOUNDARY FROM THE WEST SHOULD WORK ITS WAY THROUGH EASTERN PENNSYLVANIA, NORTHEASTERN MARYLAND, DELAWARE AND NEW JERSEY LATE ON WEDNESDAY NIGHT. IT WILL ACT TO PUSH THE PLUME OF DEEP MOISTURE FARTHER OFF THE COAST AND IT SHOULD BRING AN END TO THE PRECIPITATION IN OUR REGION. THE MID LEVEL SHORT WAVE PASSING OVERHEAD ON THURSDAY AFTERNOON IS EXPECTED TO BRING A REINFORCING SHOT OF DRY AIR. THE PERIOD FROM FRIDAY THROUGH MONDAY IS EXPECTED TO FEATURE THE DEVELOPMENT OF A LONG WAVE TROUGH OVER THE EASTERN HALF OF THE COUNTRY. WE ARE FORECASTING A COLD FRONTAL PASSAGE AROUND FRIDAY NIGHT AND ANOTHER ONE ABOUT SUNDAY. THE FIRST MAY HAVE LIMITED MOISTURE ASSOCIATED WITH IT AND THE SECOND COLD FRONT LOOKS TO BRING A BETTER CHANCE OF SHOWERS. DURING THEN PERIOD FROM TUESDAY NIGHT THROUGH MONDAY, TEMPERATURES ARE FORECAST TO BEGIN ABOVE NORMAL AND END A BIT BELOW NORMAL. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS CONTINUE EARLY THIS MORNING. A FEW RAIN SHOWERS WILL CROSS THE AREA THROUGH ABOUT 0800 UTC. BASED ON THE DRY AIRMASS IN PLACE AND VISIBILITY VALUES UPSTREAM...VISIBILITIES SHOULD REMAIN VFR. CEILINGS COULD DROP TO MVFR AT KMIV AND KACY AS EARLY AS 0900 UTC...BASED ON THE CEILINGS UPSTREAM ACROSS MARYLAND AND VIRGINA. ELSEWHERE...VFR CEILINGS ARE EXPECTED THROUGH 1200 UTC TUESDAY. CEILINGS SHOULD BECOME MVFR FROM SOUTH TO NORTH BETWEEN 1100 AND 1400 UTC. AFTER CEILINGS SHOULD VARY FROM 1200 TO 2000 FEET FOR MUCH OF THE DAY. ISOLATED THUNDERSTORMS ARE POSSIBLE SOUTH OF A KRDG-KPHL-KMJX LINE AFTER 1800 UTC...BUT THERE IS NOT ENOUGH CONFIDENCE IN THIS OCCURRENCE YET TO INCLUDE IN THE NEW FORECAST. WINDS SHOULD GENERALLY AVERAGE LESS THAN 10 KNOTS FROM THE NORTHEAST THIS MORNING TO SOUTHEAST THIS AFTERNOON. AS A WARM FRONT APPROACHES THIS EVENING...CEILINGS WILL DROP TO IFR FROM SOUTH TO NORTH BETWEEN 2300 UTC AND 0300 UTC WEDNESDAY. CEILINGS ARE THEN EXPECTED TO DROP TO LIFR BETWEEN 0400 UTC AND 0600 UTC WEDNESDAY...AND REMAIN THERE THROUGH 1200 UTC WEDNESDAY. AGAIN...THE COULD BE ISOLATED THUNDERSTORMS SOUTH OF A KRDG-KPHL-KMJX LINE...BUT IT IS TOO FAR AWAY TO CARRY IN THE FORECAST YET. WINDS SHOULD SLOW VEER TO THE SOUTHEAST...AND REMAIN 10 KNOTS OR LESS. OUTLOOK... WEDNESDAY MORNING...LOW CLOUDS WITH A CHANCE OF RAIN AND DRIZZLE. WIDESPREAD IFR AND MVFR CONDITIONS ARE EXPECTED. WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT...MAINLY VFR. HOWEVER, PERIODS OF MVFR AND IFR ARE POSSIBLE IN SHOWERS AND SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. THURSDAY THROUGH SATURDAY...MAINLY VFR. && .MARINE... THE WEAK RIDGE OF HIGH PRESSURE OVER THE WATERS TONIGHT WILL MOVE OFF TO THE EAST ON TUESDAY. THIS WILL ALLOW LOW PRESSURE TO THE WEST AND ITS ASSOCIATED WARM FRONT TO MOVE CLOSER DURING THE DAY. WINDS WILL BE SW THIS EVENING...THEN SHIFT TO MORE SRLY OR SERLY OVERNIGHT. WIND SPEEDS ARE EXPECTED TO REMAIN MOSTLY AROUND 10 KTS OR LESS TONIGHT AND THEN 10 TO 15 KTS ON TUESDAY. INCREASING CLOUDS TONIGHT...THEN SCATTERED SHOWERS ARE EXPECTED TO MOVE ACROSS THE WATERS TUESDAY. SEAS MOSTLY AROUND 2 FT ON THE OCEAN TONIGHT AND THEN 3 TO 4 FT ON TUESDAY. MOSTLY 1 TO 2 FT ON DEL BAY THRU TUESDAY. OUTLOOK... A WARM FRONT FROM THE SOUTH IS FORECAST TO LIFT ACROSS THE COASTAL WATERS OF DELAWARE AND NEW JERSEY ON WEDNESDAY. ANOTHER FRONTAL BOUNDARY FROM THE WEST IS EXPECTED LATE ON WEDNESDAY NIGHT. A COLD FRONT FROM THE NORTHWEST SHOULD ARRIVE ON FRIDAY NIGHT. WIND SPEEDS AND WAVE HEIGHTS ARE ANTICIPATED TO REMAIN BELOW THE SMALL CRAFT ADVISORY CRITERIA FROM TUESDAY NIGHT THROUGH SATURDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...IOVINO NEAR TERM...HAYES SHORT TERM...AMC LONG TERM...IOVINO AVIATION...IOVINO/HAYES MARINE...AMC/IOVINO
AREA FORECAST DISCUSSION
NWS MIAMI FL
952 PM EDT WED OCT 3 2012 .UPDATE... NO CHANGES EXPECTED TO CURRENT FORECAST PACKAGE. 00Z SOUNDING SHOWING A DRIER ATMOSPHERE (AS EXPECTED)...WITH PWATS NEAR 1.80 IN. EASTERLY FLOW IS PREVAILING ACROSS THE AREA...AS THE HIGH PRESSURE RIDGE OVER THE ATLANTIC CONTINUES MOVING TO THE WEST. CURRENT MODELS IN AGREEMENT THAT A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE THROUGH THIS EVENING...BUT THIS ACTIVITY IS NOT AS WIDESPREAD AS PREVIOUS DAYS. && .PREV DISCUSSION... /ISSUED 743 PM EDT WED OCT 3 2012/ AVIATION... MID LEVEL RIDGING CONTINUES TO SLOWLY PUSH INTO THE SOUTH FLORIDA AREA FROM THE WESTERN ATLANTIC KEEPING THE AREA MOSTLY DRY THIS EVENING. ONLY ORGANIZED CONVECTION IS ACROSS KRSW AND AREAS TO THE NORTH. LATEST HRRR KEEPS THIS ACTIVITY WELL NORTH OF THE TERMINALS THROUGH THE EVENING. ISOLATED SHRAS/TSRAS WRAPPING AROUND THE SOUTHERN EDGE OF THE RIDGE ARE SEEN ACROSS THE NEARSHORE ATLANTIC WATERS PUSHING TO THE WEST. CURRENTLY THIS ACTIVITY LOOKS TO MISS THE EAST COAST TERMINALS TO THE SOUTH. THEREFORE, KEPT VCSH/VCTS MENTION OUT OF TAFS FOR NOW...WILL AMEND AS NEEDED. PREV DISCUSSION... /ISSUED 247 PM EDT WED OCT 3 2012/ DISCUSSION... THE MAJOR SYNOPTIC FEATURES ACROSS THE REGION INCLUDE SURFACE HIGH PRESSURE ACROSS THE WESTERN ATLANTIC AND A STATIONARY FRONT EXTENDING FROM NEAR THE YUCATAN PENINSULA NORTHWARD THROUGH THE EASTERN GULF AND INTO THE SOUTHEAST U.S. THE ORIENTATION OF THE SURFACE AND LOW LEVEL RIDGE IS KEEPING CONSIDERABLE CLOUDINESS AND SHOWERS JUST TO THE WEST OF THE CWA BUT AS THE AFTERNOON PROGRESSES SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO FORM ACROSS THE CWA...WITH MOST OF THE COVERAGE EXPECTED TO BE ACROSS THE NORTHERN AND NORTHWESTERN INTERIOR PARTS OF THE CWA LATER THIS AFTERNOON AND EARLY EVENING. IT IS POSSIBLE THAT OUTFLOW BOUNDARIES FROM THE CONVECTION IN THE EASTERN GULF COULD ALSO INITIATE CONVECTION ACROSS THE OFF SHORE GULF WATERS OR NORTHWESTERN INTERIOR PORTIONS OF SOUTH FLORIDA LATE THIS AFTERNOON OR INTO THE EVENING. THE AFOREMENTIONED RIDGE IN THE WESTERN ATLANTIC IS FORECAST TO SLOWLY DRIFT WESTWARD TONIGHT INTO THURSDAY WHICH WILL CONTINUE TO KEEP THE DEEP LAYERED FRONTAL BOUNDARY MOISTURE WEST OF THE CWA AND ACROSS THE EASTERN GULF. HOWEVER...THE LATEST GUIDANCE AND RECENT SATELLITE IMAGERY INDICATE AN ADDITIONAL SOURCE OF LOW LEVEL MOISTURE CURRENTLY ACROSS THE CENTRAL BAHAMAS ENTERING THE REGION TONIGHT INTO THURSDAY...ALLOWING FOR DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS ON THURSDAY. SIMILAR CONDITIONS WILL LINGER INTO FRIDAY. MARINE... FOR THE REMAINDER OF THE WORK WEEK AND INTO THE WEEKEND THE GUIDANCE INDICATES MAINLY EASTERLY FLOW NEAR 15 KNOTS OR LESS WITH SEAS FORECAST TO BE NEAR 2 TO 3 FEET ACROSS THE REGIONAL ATLANTIC WATERS AND 1 TO 2 FEET ACROSS THE GULF WATERS. FIRE WEATHER... NO FIRE WEATHER CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 78 89 78 88 / 20 30 20 30 FORT LAUDERDALE 77 88 78 88 / 20 30 20 20 MIAMI 76 89 77 89 / 20 30 20 30 NAPLES 75 90 76 90 / 20 30 20 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...17/ERA AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
743 PM EDT WED OCT 3 2012 .AVIATION... MID LEVEL RIDGING CONTINUES TO SLOWLY PUSH INTO THE SOUTH FLORIDA AREA FROM THE WESTERN ATLANTIC KEEPING THE AREA MOSTLY DRY THIS EVENING. ONLY ORGANIZED CONVECTION IS ACROSS KRSW AND AREAS TO THE NORTH. LATEST HRRR KEEPS THIS ACTIVITY WELL NORTH OF THE TERMINALS THROUGH THE EVENING. ISOLATED SHRAS/TSRAS WRAPPING AROUND THE SOUTHERN EDGE OF THE RIDGE ARE SEEN ACROSS THE NEARSHORE ATLANTIC WATERS PUSHING TO THE WEST. CURRENTLY THIS ACTIVITY LOOKS TO MISS THE EAST COAST TERMINALS TO THE SOUTH. THEREFORE, KEPT VCSH/VCTS MENTION OUT OF TAFS FOR NOW...WILL AMEND AS NEEDED. && .PREV DISCUSSION... /ISSUED 247 PM EDT WED OCT 3 2012/ DISCUSSION... THE MAJOR SYNOPTIC FEATURES ACROSS THE REGION INCLUDE SURFACE HIGH PRESSURE ACROSS THE WESTERN ATLANTIC AND A STATIONARY FRONT EXTENDING FROM NEAR THE YUCATAN PENINSULA NORTHWARD THROUGH THE EASTERN GULF AND INTO THE SOUTHEAST U.S. THE ORIENTATION OF THE SURFACE AND LOW LEVEL RIDGE IS KEEPING CONSIDERABLE CLOUDINESS AND SHOWERS JUST TO THE WEST OF THE CWA BUT AS THE AFTERNOON PROGRESSES SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO FORM ACROSS THE CWA...WITH MOST OF THE COVERAGE EXPECTED TO BE ACROSS THE NORTHERN AND NORTHWESTERN INTERIOR PARTS OF THE CWA LATER THIS AFTERNOON AND EARLY EVENING. IT IS POSSIBLE THAT OUTFLOW BOUNDARIES FROM THE CONVECTION IN THE EASTERN GULF COULD ALSO INITIATE CONVECTION ACROSS THE OFF SHORE GULF WATERS OR NORTHWESTERN INTERIOR PORTIONS OF SOUTH FLORIDA LATE THIS AFTERNOON OR INTO THE EVENING. THE AFOREMENTIONED RIDGE IN THE WESTERN ATLANTIC IS FORECAST TO SLOWLY DRIFT WESTWARD TONIGHT INTO THURSDAY WHICH WILL CONTINUE TO KEEP THE DEEP LAYERED FRONTAL BOUNDARY MOISTURE WEST OF THE CWA AND ACROSS THE EASTERN GULF. HOWEVER...THE LATEST GUIDANCE AND RECENT SATELLITE IMAGERY INDICATE AN ADDITIONAL SOURCE OF LOW LEVEL MOISTURE CURRENTLY ACROSS THE CENTRAL BAHAMAS ENTERING THE REGION TONIGHT INTO THURSDAY...ALLOWING FOR DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS ON THURSDAY. SIMILAR CONDITIONS WILL LINGER INTO FRIDAY. MARINE... FOR THE REMAINDER OF THE WORK WEEK AND INTO THE WEEKEND THE GUIDANCE INDICATES MAINLY EASTERLY FLOW NEAR 15 KNOTS OR LESS WITH SEAS FORECAST TO BE NEAR 2 TO 3 FEET ACROSS THE REGIONAL ATLANTIC WATERS AND 1 TO 2 FEET ACROSS THE GULF WATERS. FIRE WEATHER... NO FIRE WEATHER CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 78 89 78 88 / 20 30 20 30 FORT LAUDERDALE 77 88 78 88 / 20 30 20 20 MIAMI 76 89 77 89 / 20 30 20 30 NAPLES 75 90 76 90 / 20 30 20 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...17/ERA AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1152 AM MDT TUE OCT 2 2012 .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 316 AM MDT TUE OCT 2 2012 LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW POSITIVELY TILTED TROUGH EXTENDING SOUTH ALONG THE MISSISSIPPI VALLEY ACROSS EASTERN TEXAS. LARGE SCALE RIDGE CONTINUE TO SIT IN PLACE ACROSS THE SOUTHWEST US JUST EAST OF A REX BLOCK OVER THE CENTRAL PACIFIC. A SHORTWAVE RIDGE IS CURRENTLY IN PLACE OVER THE HIGH PLAINS. AT THE SURFACE HIGH PRESSURE CURRENTLY EXTENDS ACROSS WESTERN KANSAS. TEMPERATURES EARLY THIS MORNING HAVE COOLED DOWN TO THE MID TO UPPER 30S ACROSS MUCH OF THE CWA...WITH A FEW ISOLATED LOCATIONS NEAR 32F. I KEPT PATCHY FROST MENTION THROUGH ABOUT 15Z THIS MORNING. TEMPERATURES SHOULD QUICKLY RECOVER AFTER SUNRISE WITH SW FLOW AND GOOD WAA. AFTERNOON TEMPERATURES SHOULD BE IN THE UPPER 70S/LOW 80S. WITH LARGE SCALE SUBSIDENCE IN PLACE THROUGH WEDNESDAY...DRY CONDITIONS AND WARMER TEMPERATURES ARE EXPECTED. A STRONG COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA WEDNESDAY/WEDNESDAY NIGHT AS A SHORTWAVE TROUGH DIGS SOUTH AND EAST ACROSS THE NORTHERN PLAINS. THERE IS STILL QUITE A BIT OF UNCERTAINTY REGARDING THE TIMING AND STRENGTH OF THIS FRONT...WITH MOST GUIDANCE NOW FAVORING FROPA WEDNESDAY EVENING. WITH GOOD WAA AHEAD OF THIS FRONT TEMPERATURES SHOULD BE WARMER WITH HIGHS IN AT LEAST THE MID 80S ACROSS MUCH OF THE CWA WED. THERE WILL ALSO BE POTENTIAL RED FLAG CONDITIONS DURING THE AFTERNOON WED DEPENDING ON FRONTAL TIMING AND AFTERNOON MIXING. WINDY CONDITIONS ARE EXPECTED WED NIGHT BEHIND THE FRONT...WITH LATEST NAM SUPPORTING POSSIBLE ADVISORY LEVEL WINDS. SINCE THE NAM SEEMS TO HAVE THE WORST RUN-RUN CONTINUITY I DO NOT HAVE A LOT OF CONFIDENCE IN IT SOLUTION AT THIS POINT. WITH LARGE SCALE ASCENT AND BETTER MOISTURE TO THE NORTH I DO NOT HAVE A LOT OF CONFIDENCE IN PRECIP POTENTIAL WED NIGHT...WITH MOST GUIDANCE TRENDING NORTH FROM PREVIOUS RUNS. I KEPT AN AREA OF CHANCE POPS IN OUR NORTHEAST LATE WED NIGHT WHERE CONFIDENCE IS HIGHEST. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 316 AM MDT TUE OCT 2 2012 THURSDAY AND THURSDAY NIGHT...BEHIND THE COLD FRONT MUCH COOLER TEMPERATURES WILL ARRIVE WITH HIGHS ON THU IN THE 50S/LOW 60S. IT DOES APPEAR THERE WILL BE SOME HIGH CLOUDS...SO I TEMPERED THE LOW TEMPERATURE FORECAST FOR NOW...THOUGH MOST LOCATIONS SHOULD STILL SEE MID 30S. DEPENDING ON CLOUD COVER WE COULD MUCH COOLER WITH OUR FIRST WIDESPREAD FROST OF THE SEASON POSSIBLE FOR MANY LOCATIONS...ESPECIALLY CONSIDERING HOW QUICKLY TEMPERATURES COOLED OFF THIS PAST NIGHT. A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH WILL SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND SATURDAY KEEPING TEMPERATURES BELOW NORMAL FRI-SUN AND INCREASING THE POTENTIAL FOR PRECIPITATION. THIS WILL MARK THE BEGINNING OF A PERIOD WHERE A MEAN LONG WAVE TROUGH WILL TEND TO SET UP OVER THE CENTRAL U.S. FOLLOWED BY A SERIES OF REINFORCING UPPER LEVEL SHORT WAVE TROUGHS. THE BEST POTENTIAL FOR RAIN WILL BE FRIDAY INTO SATURDAY CENTERED ON FRIDAY NIGHT WITH UPPER LEVEL /250 MB/ JET SUPPORT AIDING IN THE SYNOPTIC SCALE LIFT. GIVEN FORECAST 850 MB TEMPERATURES OF 0 TO -2C FRIDAY NIGHT THERE IS A POTENTIAL FOR A RAIN-SNOW MIX IF THAT PANS OUT. SATURDAY AFTERNOON TEMPERATURES WILL LIKELY HOLD IN THE 40S WHICH WILL BE 25 DEGREES BELOW NORMAL FOR EARLY OCTOBER. AS THE SURFACE HIGH SETTLES INTO THE AREA SATURDAY NIGHT...THE COMBINATION OF COLD 850 MB TEMPERATURES OF -2 TO +2C...AND GENERAL SUBSIDENCE WITH THE SURFACE HIGH AND BRIEF MID-LEVEL RIDGING...THERE IS A GOOD SHOT AT A WIDESPREAD FROST AND POSSIBLE HARD FREEZE. SOME MODERATION IN TEMPERATURES WILL OCCUR SUNDAY AND ESPECIALLY MONDAY WITH HIGHS CLIMBING BACK INTO THE 60S BEFORE ANOTHER COLD FRONT ARRIVES TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1134 AM MDT TUE OCT 2 2012 BREEZY WINDS AT BOTH TERMINALS THIS AFTERNOON AS LEE TROUGH DEEPENS OVER EASTERN COLORADO. AS THIS TROUGH SHIFTS EAST OVERNIGHT...WINDS WILL BECOME MORE SOUTH TO SOUTHEASTERLY AROUND 10 KTS THROUGH THE OVERNIGHT PERIOD. WINDS WILL BECOME LIGHT AND VARIABLE AFTER 12Z AS SURFACE TROUGH SETS UP ACROSS THE TERMINALS AHEAD OF AN APPROACHING COLD FRONT SET TO MOVE ACROSS THE TERMINALS BY TOMORROW EVENING. SKIES WILL REMAIN CLEAR WITH A FEW HIGH CIRRUS CLOUDS THROUGH THE PREVAILING PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...DR/DLF AVIATION...PMM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
507 AM MDT TUE OCT 2 2012 .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 316 AM MDT TUE OCT 2 2012 LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW POSITIVELY TILTED TROUGH EXTENDING SOUTH ALONG THE MISSISSIPPI VALLEY ACROSS EASTERN TEXAS. LARGE SCALE RIDGE CONTINUE TO SIT IN PLACE ACROSS THE SOUTHWEST US JUST EAST OF A REX BLOCK OVER THE CENTRAL PACIFIC. A SHORTWAVE RIDGE IS CURRENTLY IN PLACE OVER THE HIGH PLAINS. AT THE SURFACE HIGH PRESSURE CURRENTLY EXTENDS ACROSS WESTERN KANSAS. TEMPERATURES EARLY THIS MORNING HAVE COOLED DOWN TO THE MID TO UPPER 30S ACROSS MUCH OF THE CWA...WITH A FEW ISOLATED LOCATIONS NEAR 32F. I KEPT PATCHY FROST MENTION THROUGH ABOUT 15Z THIS MORNING. TEMPERATURES SHOULD QUICKLY RECOVER AFTER SUNRISE WITH SW FLOW AND GOOD WAA. AFTERNOON TEMPERATURES SHOULD BE IN THE UPPER 70S/LOW 80S. WITH LARGE SCALE SUBSIDENCE IN PLACE THROUGH WEDNESDAY...DRY CONDITIONS AND WARMER TEMPERATURES ARE EXPECTED. A STRONG COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA WEDNESDAY/WEDNESDAY NIGHT AS A SHORTWAVE TROUGH DIGS SOUTH AND EAST ACROSS THE NORTHERN PLAINS. THERE IS STILL QUITE A BIT OF UNCERTAINTY REGARDING THE TIMING AND STRENGTH OF THIS FRONT...WITH MOST GUIDANCE NOW FAVORING FROPA WEDNESDAY EVENING. WITH GOOD WAA AHEAD OF THIS FRONT TEMPERATURES SHOULD BE WARMER WITH HIGHS IN AT LEAST THE MID 80S ACROSS MUCH OF THE CWA WED. THERE WILL ALSO BE POTENTIAL RED FLAG CONDITIONS DURING THE AFTERNOON WED DEPENDING ON FRONTAL TIMING AND AFTERNOON MIXING. WINDY CONDITIONS ARE EXPECTED WED NIGHT BEHIND THE FRONT...WITH LATEST NAM SUPPORTING POSSIBLE ADVISORY LEVEL WINDS. SINCE THE NAM SEEMS TO HAVE THE WORST RUN-RUN CONTINUITY I DO NOT HAVE A LOT OF CONFIDENCE IN IT SOLUTION AT THIS POINT. WITH LARGE SCALE ASCENT AND BETTER MOISTURE TO THE NORTH I DO NOT HAVE A LOT OF CONFIDENCE IN PRECIP POTENTIAL WED NIGHT...WITH MOST GUIDANCE TRENDING NORTH FROM PREVIOUS RUNS. I KEPT AN AREA OF CHANCE POPS IN OUR NORTHEAST LATE WED NIGHT WHERE CONFIDENCE IS HIGHEST. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 316 AM MDT TUE OCT 2 2012 THURSDAY AND THURSDAY NIGHT...BEHIND THE COLD FRONT MUCH COOLER TEMPERATURES WILL ARRIVE WITH HIGHS ON THU IN THE 50S/LOW 60S. IT DOES APPEAR THERE WILL BE SOME HIGH CLOUDS...SO I TEMPERED THE LOW TEMPERATURE FORECAST FOR NOW...THOUGH MOST LOCATIONS SHOULD STILL SEE MID 30S. DEPENDING ON CLOUD COVER WE COULD MUCH COOLER WITH OUR FIRST WIDESPREAD FROST OF THE SEASON POSSIBLE FOR MANY LOCATIONS...ESPECIALLY CONSIDERING HOW QUICKLY TEMPERATURES COOLED OFF THIS PAST NIGHT. A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH WILL SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND SATURDAY KEEPING TEMPERATURES BELOW NORMAL FRI-SUN AND INCREASING THE POTENTIAL FOR PRECIPITATION. THIS WILL MARK THE BEGINNING OF A PERIOD WHERE A MEAN LONG WAVE TROUGH WILL TEND TO SET UP OVER THE CENTRAL U.S. FOLLOWED BY A SERIES OF REINFORCING UPPER LEVEL SHORT WAVE TROUGHS. THE BEST POTENTIAL FOR RAIN WILL BE FRIDAY INTO SATURDAY CENTERED ON FRIDAY NIGHT WITH UPPER LEVEL /250 MB/ JET SUPPORT AIDING IN THE SYNOPTIC SCALE LIFT. GIVEN FORECAST 850 MB TEMPERATURES OF 0 TO -2C FRIDAY NIGHT THERE IS A POTENTIAL FOR A RAIN-SNOW MIX IF THAT PANS OUT. SATURDAY AFTERNOON TEMPERATURES WILL LIKELY HOLD IN THE 40S WHICH WILL BE 25 DEGREES BELOW NORMAL FOR EARLY OCTOBER. AS THE SURFACE HIGH SETTLES INTO THE AREA SATURDAY NIGHT...THE COMBINATION OF COLD 850 MB TEMPERATURES OF -2 TO +2C...AND GENERAL SUBSIDENCE WITH THE SURFACE HIGH AND BRIEF MID-LEVEL RIDGING...THERE IS A GOOD SHOT AT A WIDESPREAD FROST AND POSSIBLE HARD FREEZE. SOME MODERATION IN TEMPERATURES WILL OCCUR SUNDAY AND ESPECIALLY MONDAY WITH HIGHS CLIMBING BACK INTO THE 60S BEFORE ANOTHER COLD FRONT ARRIVES TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 507 AM MDT TUE OCT 2 2012 VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK. LIGHT SOUTHWEST WINDS WILL INCREASE TO ABOUT 12 KT AFTER SUNRISE WITH GUSTS AROUND 20 KT AT KGLD AS THE LEE TROUGH DEEPENS OVER EASTERN COLORADO. WINDS WILL SHIFT TO THE SOUTH TO BE AROUND 10KT DURING THE AFTERNOON AS THE SURFACE TROUGH SHIFTS EAST. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...DR/DLF AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
317 AM MDT TUE OCT 2 2012 .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 316 AM MDT TUE OCT 2 2012 LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW POSITIVELY TILTED TROUGH EXTENDING SOUTH ALONG THE MISSISSIPPI VALLEY ACROSS EASTERN TEXAS. LARGE SCALE RIDGE CONTINUE TO SIT IN PLACE ACROSS THE SOUTHWEST US JUST EAST OF A REX BLOCK OVER THE CENTRAL PACIFIC. A SHORTWAVE RIDGE IS CURRENTLY IN PLACE OVER THE HIGH PLAINS. AT THE SURFACE HIGH PRESSURE CURRENTLY EXTENDS ACROSS WESTERN KANSAS. TEMPERATURES EARLY THIS MORNING HAVE COOLED DOWN TO THE MID TO UPPER 30S ACROSS MUCH OF THE CWA...WITH A FEW ISOLATED LOCATIONS NEAR 32F. I KEPT PATCHY FROST MENTION THROUGH ABOUT 15Z THIS MORNING. TEMPERATURES SHOULD QUICKLY RECOVER AFTER SUNRISE WITH SW FLOW AND GOOD WAA. AFTERNOON TEMPERATURES SHOULD BE IN THE UPPER 70S/LOW 80S. WITH LARGE SCALE SUBSIDENCE IN PLACE THROUGH WEDNESDAY...DRY CONDITIONS AND WARMER TEMPERATURES ARE EXPECTED. A STRONG COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA WEDNESDAY/WEDNESDAY NIGHT AS A SHORTWAVE TROUGH DIGS SOUTH AND EAST ACROSS THE NORTHERN PLAINS. THERE IS STILL QUITE A BIT OF UNCERTAINTY REGARDING THE TIMING AND STRENGTH OF THIS FRONT...WITH MOST GUIDANCE NOW FAVORING FROPA WEDNESDAY EVENING. WITH GOOD WAA AHEAD OF THIS FRONT TEMPERATURES SHOULD BE WARMER WITH HIGHS IN AT LEAST THE MID 80S ACROSS MUCH OF THE CWA WED. THERE WILL ALSO BE POTENTIAL RED FLAG CONDITIONS DURING THE AFTERNOON WED DEPENDING ON FRONTAL TIMING AND AFTERNOON MIXING. WINDY CONDITIONS ARE EXPECTED WED NIGHT BEHIND THE FRONT...WITH LATEST NAM SUPPORTING POSSIBLE ADVISORY LEVEL WINDS. SINCE THE NAM SEEMS TO HAVE THE WORST RUN-RUN CONTINUITY I DO NOT HAVE A LOT OF CONFIDENCE IN IT SOLUTION AT THIS POINT. WITH LARGE SCALE ASCENT AND BETTER MOISTURE TO THE NORTH I DO NOT HAVE A LOT OF CONFIDENCE IN PRECIP POTENTIAL WED NIGHT...WITH MOST GUIDANCE TRENDING NORTH FROM PREVIOUS RUNS. I KEPT AN AREA OF CHANCE POPS IN OUR NORTHEAST LATE WED NIGHT WHERE CONFIDENCE IS HIGHEST. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 316 AM MDT TUE OCT 2 2012 THURSDAY AND THURSDAY NIGHT...BEHIND THE COLD FRONT MUCH COOLER TEMPERATURES WILL ARRIVE WITH HIGHS ON THU IN THE 50S/LOW 60S. IT DOES APPEAR THERE WILL BE SOME HIGH CLOUDS...SO I TEMPERED THE LOW TEMPERATURE FORECAST FOR NOW...THOUGH MOST LOCATIONS SHOULD STILL SEE MID 30S. DEPENDING ON CLOUD COVER WE COULD MUCH COOLER WITH OUR FIRST WIDESPREAD FROST OF THE SEASON POSSIBLE FOR MANY LOCATIONS...ESPECIALLY CONSIDERING HOW QUICKLY TEMPERATURES COOLED OFF THIS PAST NIGHT. A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH WILL SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND SATURDAY KEEPING TEMPERATURES BELOW NORMAL FRI-SUN AND INCREASING THE POTENTIAL FOR PRECIPITATION. THIS WILL MARK THE BEGINNING OF A PERIOD WHERE A MEAN LONG WAVE TROUGH WILL TEND TO SET UP OVER THE CENTRAL U.S. FOLLOWED BY A SERIES OF REINFORCING UPPER LEVEL SHORT WAVE TROUGHS. THE BEST POTENTIAL FOR RAIN WILL BE FRIDAY INTO SATURDAY CENTERED ON FRIDAY NIGHT WITH UPPER LEVEL /250 MB/ JET SUPPORT AIDING IN THE SYNOPTIC SCALE LIFT. GIVEN FORECAST 850 MB TEMPERATURES OF 0 TO -2C FRIDAY NIGHT THERE IS A POTENTIAL FOR A RAIN-SNOW MIX IF THAT PANS OUT. SATURDAY AFTERNOON TEMPERATURES WILL LIKELY HOLD IN THE 40S WHICH WILL BE 25 DEGREES BELOW NORMAL FOR EARLY OCTOBER. AS THE SURFACE HIGH SETTLES INTO THE AREA SATURDAY NIGHT...THE COMBINATION OF COLD 850 MB TEMPERATURES OF -2 TO +2C...AND GENERAL SUBSIDENCE WITH THE SURFACE HIGH AND BRIEF MID-LEVEL RIDGING...THERE IS A GOOD SHOT AT A WIDESPREAD FROST AND POSSIBLE HARD FREEZE. SOME MODERATION IN TEMPERATURES WILL OCCUR SUNDAY AND ESPECIALLY MONDAY WITH HIGHS CLIMBING BACK INTO THE 60S BEFORE ANOTHER COLD FRONT ARRIVES TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1118 PM MDT MON OCT 1 2012 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. LIGHT WINDS EARLY ON WILL WAY TO STRONGER SOUTHERLY WINDS DURING THE DAYTIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...DR/DLF AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
149 PM EDT TUE OCT 2 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 545 AM EDT TUE OCT 2 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A NRN STREAM SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO TO NEAR JAMES BAY AND A MAINLY ZONAL PATTERN UPSTREAM ACROSS SRN CANADA. AT THE SFC...A RIDGE FROM NW ONTARIO TO MN AND THE CNTRL PLAINS WAS BUILDING INTO THE REGION BEHIND A COLD FRONT THAT HAS MOVED EAST OF UPPER MICHIGAN. MUCH DRIER AIR...PER 00Z KINL SOUNDING WAS MOVING INTO THE REGION BRINGING CLEARING SKIES OVER THE WRN CWA. HOWEVER...LOWER CLOUDS REMAINED OVER THE EAST WITH LINGERING CYCLONIC NRLY FLOW. MDLS LOW LEVEL RH PROGS SUGGEST THAT THE LOW CLOUDS SHOULD DISSIPATE BY LATE MORNING AS DRY ACYC FLOW CONTINUES TO SPREAD TO THE EAST AND DAYTIME HEATING INCREASES. ALTHOUGH TEMPS WILL BE A BIT COOLER THAN MONDAY...READINGS AT OR SLIGHTLY ABOVER SEASONAL AVERAGES...IN THE LOWER TO MID 60S...ARE EXPECTED GIVEN 850 MB TEMPS IN THE 4C TO 6C RANGE. AS THE RIDGE SETTLES TO THE SOUTHEAST...WEAK SRLY FLOW WILL DEVELOP TONIGHT. WITH LINGERING LOW LEVEL MOISTURE AND GOOD RADIATIONAL COOLING CONDITIONS...SOME PATCHY FOG MAY BE POSSIBLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 545 AM EDT TUE OCT 2 2012 WED LOOKS OVERALL PRETTY QUIET OVER THE CWA...WITH SOME RAIN POSSIBLY MOVING INTO THE ERN CWA LATE IN THE DAY AND WED NIGHT AS A WEAKENING UPPER TROUGH MOVES SE OF THE CWA. INTERESTING WEATHER STARTS LATE WED NIGHT INTO THU AS MODELS SHOW A LOW PRESSURE SYSTEM DEEPENING SOMEWHERE NEAR OR OVER THE CWA. THE SYSTEM WILL DEVELOP FROM AN UPPER TROUGH PUSHING INTO THE AREA FROM THE NRN PLAINS THU. FORECAST CONFIDENCE REMAINS VERY LOW AS MODEL CONTINUITY IS EVEN WORSE...AND MODEL AGREEMENT LOWER...THAN THIS TIME YESTERDAY. IF THERE IS A TREND TO PICK UP ON OVER THE LAST FEW DAYS IT IS A WEAKENING ONE. THE GFS SHOWS THIS MORE THAN OTHER MODELS...ONLY DEEPENING THE SFC LOW FROM 1012MB TO 1007MB AS IT MOVES ACROSS THE CENTER OF THE CWA. NOT ONLY IS INTENSITY OF THE SYSTEM IN QUESTION...THE TRACK OF THE SYSTEM IS CONSIDERABLY UNCERTAIN. MODELS VARY FROM MOVING THE LOW TO THE N OF LAKE SUPERIOR...TO MOVING IT ALONG THE SE PERIPHERY OF THE CWA. TRACK VARIABILITY WILL PLAY ONE OF THE LARGEST ROLES IN PRECIP AMOUNTS...SINCE THE MOST PRECIP WILL BE IN THE COMMA SECTION OF THE SYSTEM. REGARDLESS OF THE PATH OF THE SYSTEM...THERE SHOULD STILL BE SOME GALES ON THE BACK SIDE OF THE LOW GIVEN A GOOD PRESSURE GRADIENT AND COLD AIR MOVING IN. MODELS AGREE A LITTLE BETTER ON DETAILS RELATED TO THE COLD AIR MOVING IN. BY 12Z FRI...850MB TEMPS LOOK TO BE AROUND -3C TO -5C WITH W TO NW LOW LEVEL FLOW. THE GFS IS FASTER THAN THE ECMWF WITH BRINGING IN A SECONDARY UPPER TROUGH...SO THE GFS BRINGS THE EVEN COLDER AIR IN FASTER. BY 00Z SAT THE GFS HAS 850MB TEMPS OF -6C TO -8C OVER MUCH OF THE CWA...WHILE THE ECMWF WAITS UNTIL AROUND 12Z SUN FOR THE SAME TEMPS. THESE TEMPS COMBINED WITH NW LOW LEVEL WINDS WILL LEAD TO LAKE EFFECT RAIN/SNOW THAT WILL BEGIN TO DIMINISH AFTER THE UPPER TROUGH PASSES...850MB TEMPS WARM AND SFC RIDGING PUSHES INTO THE CWA...WHETHER THAT BE LATE SAT OR MID DAY SUN. BEST CHANCES FOR SNOW LOOK TO BE OVER THE HIGHER TERRAIN OF WRN UPPER MI...PARTICULARLY OVER THE KEWEENAW PENINSULA WHERE THE GFS SUGGESTS POTENTIAL FOR AROUND 1 INCH OF SNOW. OVERNIGHT LOWS SHOULD BE AROUND OR JUST ABOVE FREEZING FRI NIGHT AND SAT NIGHT...WITH DAYTIME HIGHS IN THE LOW TO MID 40S...SO SIGNIFICANT ACCUMULATIONS OF SNOW WOULD BE MORE LIMITED TO GRASSY SURFACES AND WOULD NOT STICK AROUND TOO LONG. FOR SUN AND MON...TEMPS SHOULD BE WARMER AS SW-W LOW LEVEL FLOW BRINGS WARMER AIR OVERHEAD. THERE IS A LOT OF UNCERTAINTY THIS FAR OUT SO JUST USED CONSENSUS OF MODELS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 149 PM EDT TUE OCT 2 2012 MVFR CIGS AT KSAW SHOWING SIGNS OF BREAKING UP ON VIS SATELLITE SO EXPECT VFR CONDITIONS AT ALL TAF SITES BY 19Z AS HIGH PRESSURE CONTINUES TO DOMINATE THE REGION. LIGHT WINDS AT SFC AND STRONG SUBSIDENCE/DRYING ALOFT COULD LEAD TO SOME FOG FORMATION AT KSAW LATE TONIGHT. INCLUDED A PERIOD OF IFR VSBYS AT KSAW BTWN 09-14Z. OTHERWISE...SRLY GRAD WIND SHOULD PROHIBIT FOG OVER WRN SITES...MAINTAINING VFR CONDITIONS THROUGH THE PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 545 AM EDT TUE OCT 2 2012 HIGH PRESSURE BUILDING INTO THE REGION TODAY WILL BRING DIMINISHING WINDS. WINDS WILL STAY AT OR BELOW 20 KNOTS INTO THURSDAY BEFORE THE PRESSURE GRADIENT TIGHTENS AS A STRONG LOW PRESSURE SYSTEM LIFTS INTO NORTHERN ONTARIO AND BRINGS WEST GALES THURSDAY NIGHT INTO FRIDAY. THERE IS SOME UNCERTAINTY WITH THE TRACK AND STRENGTH OF THE LOW BUT HIGHER END GALES TO 45 KNOTS MAY BE POSSIBLE OVER THE WEST AND NORTH CENTRAL PORTIONS OF THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...VOSS MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
744 AM EDT TUE OCT 2 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 545 AM EDT TUE OCT 2 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A NRN STREAM SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO TO NEAR JAMES BAY AND A MAINLY ZONAL PATTERN UPSTREAM ACROSS SRN CANADA. AT THE SFC...A RIDGE FROM NW ONTARIO TO MN AND THE CNTRL PLAINS WAS BUILDING INTO THE REGION BEHIND A COLD FRONT THAT HAS MOVED EAST OF UPPER MICHIGAN. MUCH DRIER AIR...PER 00Z KINL SOUNDING WAS MOVING INTO THE REGION BRINGING CLEARING SKIES OVER THE WRN CWA. HOWEVER...LOWER CLOUDS REMAINED OVER THE EAST WITH LINGERING CYCLONIC NRLY FLOW. MDLS LOW LEVEL RH PROGS SUGGEST THAT THE LOW CLOUDS SHOULD DISSIPATE BY LATE MORNING AS DRY ACYC FLOW CONTINUES TO SPREAD TO THE EAST AND DAYTIME HEATING INCREASES. ALTHOUGH TEMPS WILL BE A BIT COOLER THAN MONDAY...READINGS AT OR SLIGHTLY ABOVER SEASONAL AVERAGES...IN THE LOWER TO MID 60S...ARE EXPECTED GIVEN 850 MB TEMPS IN THE 4C TO 6C RANGE. AS THE RIDGE SETTLES TO THE SOUTHEAST...WEAK SRLY FLOW WILL DEVELOP TONIGHT. WITH LINGERING LOW LEVEL MOISTURE AND GOOD RADIATIONAL COOLING CONDITIONS...SOME PATCHY FOG MAY BE POSSIBLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 545 AM EDT TUE OCT 2 2012 WED LOOKS OVERALL PRETTY QUIET OVER THE CWA...WITH SOME RAIN POSSIBLY MOVING INTO THE ERN CWA LATE IN THE DAY AND WED NIGHT AS A WEAKENING UPPER TROUGH MOVES SE OF THE CWA. INTERESTING WEATHER STARTS LATE WED NIGHT INTO THU AS MODELS SHOW A LOW PRESSURE SYSTEM DEEPENING SOMEWHERE NEAR OR OVER THE CWA. THE SYSTEM WILL DEVELOP FROM AN UPPER TROUGH PUSHING INTO THE AREA FROM THE NRN PLAINS THU. FORECAST CONFIDENCE REMAINS VERY LOW AS MODEL CONTINUITY IS EVEN WORSE...AND MODEL AGREEMENT LOWER...THAN THIS TIME YESTERDAY. IF THERE IS A TREND TO PICK UP ON OVER THE LAST FEW DAYS IT IS A WEAKENING ONE. THE GFS SHOWS THIS MORE THAN OTHER MODELS...ONLY DEEPENING THE SFC LOW FROM 1012MB TO 1007MB AS IT MOVES ACROSS THE CENTER OF THE CWA. NOT ONLY IS INTENSITY OF THE SYSTEM IN QUESTION...THE TRACK OF THE SYSTEM IS CONSIDERABLY UNCERTAIN. MODELS VARY FROM MOVING THE LOW TO THE N OF LAKE SUPERIOR...TO MOVING IT ALONG THE SE PERIPHERY OF THE CWA. TRACK VARIABILITY WILL PLAY ONE OF THE LARGEST ROLES IN PRECIP AMOUNTS...SINCE THE MOST PRECIP WILL BE IN THE COMMA SECTION OF THE SYSTEM. REGARDLESS OF THE PATH OF THE SYSTEM...THERE SHOULD STILL BE SOME GALES ON THE BACK SIDE OF THE LOW GIVEN A GOOD PRESSURE GRADIENT AND COLD AIR MOVING IN. MODELS AGREE A LITTLE BETTER ON DETAILS RELATED TO THE COLD AIR MOVING IN. BY 12Z FRI...850MB TEMPS LOOK TO BE AROUND -3C TO -5C WITH W TO NW LOW LEVEL FLOW. THE GFS IS FASTER THAN THE ECMWF WITH BRINGING IN A SECONDARY UPPER TROUGH...SO THE GFS BRINGS THE EVEN COLDER AIR IN FASTER. BY 00Z SAT THE GFS HAS 850MB TEMPS OF -6C TO -8C OVER MUCH OF THE CWA...WHILE THE ECMWF WAITS UNTIL AROUND 12Z SUN FOR THE SAME TEMPS. THESE TEMPS COMBINED WITH NW LOW LEVEL WINDS WILL LEAD TO LAKE EFFECT RAIN/SNOW THAT WILL BEGIN TO DIMINISH AFTER THE UPPER TROUGH PASSES...850MB TEMPS WARM AND SFC RIDGING PUSHES INTO THE CWA...WHETHER THAT BE LATE SAT OR MID DAY SUN. BEST CHANCES FOR SNOW LOOK TO BE OVER THE HIGHER TERRAIN OF WRN UPPER MI...PARTICULARLY OVER THE KEWEENAW PENINSULA WHERE THE GFS SUGGESTS POTENTIAL FOR AROUND 1 INCH OF SNOW. OVERNIGHT LOWS SHOULD BE AROUND OR JUST ABOVE FREEZING FRI NIGHT AND SAT NIGHT...WITH DAYTIME HIGHS IN THE LOW TO MID 40S...SO SIGNIFICANT ACCUMULATIONS OF SNOW WOULD BE MORE LIMITED TO GRASSY SURFACES AND WOULD NOT STICK AROUND TOO LONG. FOR SUN AND MON...TEMPS SHOULD BE WARMER AS SW-W LOW LEVEL FLOW BRINGS WARMER AIR OVERHEAD. THERE IS A LOT OF UNCERTAINTY THIS FAR OUT SO JUST USED CONSENSUS OF MODELS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 740 AM EDT TUE OCT 2 2012 ALTHOUGH SOME SHALLOW GROUND FOG MIGHT IMPACT IWD EARLY THIS MORNING... EXPECT PREVAILING VFR CONDITIONS THERE AND AT CMX THIS FCST PERIOD AS HI PRES RDG/DRY AIRMASS TO THE W MOVES INTO THE UPR LKS. AT SAW... THE UPSLOPE N FLOW IN ADVANCE OF THE HI PRES RDG WL BRING MVFR CIGS THROUGH THE MORNING BEFORE THE ARRIVAL OF THE RIDGE BREAKS UP THE LOW CLOUDS AND BRINGS VFR CONDITIONS THE REST OF THE FCST PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 545 AM EDT TUE OCT 2 2012 HIGH PRESSURE BUILDING INTO THE REGION TODAY WILL BRING DIMINISHING WINDS. WINDS WILL STAY AT OR BELOW 20 KNOTS INTO THURSDAY BEFORE THE PRESSURE GRADIENT TIGHTENS AS A STRONG LOW PRESSURE SYSTEM LIFTS INTO NORTHERN ONTARIO AND BRINGS WEST GALES THURSDAY NIGHT INTO FRIDAY. THERE IS SOME UNCERTAINTY WITH THE TRACK AND STRENGTH OF THE LOW BUT HIGHER END GALES TO 45 KNOTS MAY BE POSSIBLE OVER THE WEST AND NORTH CENTRAL PORTIONS OF THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
547 AM EDT TUE OCT 2 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 545 AM EDT TUE OCT 2 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A NRN STREAM SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO TO NEAR JAMES BAY AND A MAINLY ZONAL PATTERN UPSTREAM ACROSS SRN CANADA. AT THE SFC...A RIDGE FROM NW ONTARIO TO MN AND THE CNTRL PLAINS WAS BUILDING INTO THE REGION BEHIND A COLD FRONT THAT HAS MOVED EAST OF UPPER MICHIGAN. MUCH DRIER AIR...PER 00Z KINL SOUNDING WAS MOVING INTO THE REGION BRINGING CLEARING SKIES OVER THE WRN CWA. HOWEVER...LOWER CLOUDS REMAINED OVER THE EAST WITH LINGERING CYCLONIC NRLY FLOW. MDLS LOW LEVEL RH PROGS SUGGEST THAT THE LOW CLOUDS SHOULD DISSIPATE BY LATE MORNING AS DRY ACYC FLOW CONTINUES TO SPREAD TO THE EAST AND DAYTIME HEATING INCREASES. ALTHOUGH TEMPS WILL BE A BIT COOLER THAN MONDAY...READINGS AT OR SLIGHTLY ABOVER SEASONAL AVERAGES...IN THE LOWER TO MID 60S...ARE EXPECTED GIVEN 850 MB TEMPS IN THE 4C TO 6C RANGE. AS THE RIDGE SETTLES TO THE SOUTHEAST...WEAK SRLY FLOW WILL DEVELOP TONIGHT. WITH LINGERING LOW LEVEL MOISTURE AND GOOD RADIATIONAL COOLING CONDITIONS...SOME PATCHY FOG MAY BE POSSIBLE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 545 AM EDT TUE OCT 2 2012 WED LOOKS OVERALL PRETTY QUIET OVER THE CWA...WITH SOME RAIN POSSIBLY MOVING INTO THE ERN CWA LATE IN THE DAY AND WED NIGHT AS A WEAKENING UPPER TROUGH MOVES SE OF THE CWA. INTERESTING WEATHER STARTS LATE WED NIGHT INTO THU AS MODELS SHOW A LOW PRESSURE SYSTEM DEEPENING SOMEWHERE NEAR OR OVER THE CWA. THE SYSTEM WILL DEVELOP FROM AN UPPER TROUGH PUSHING INTO THE AREA FROM THE NRN PLAINS THU. FORECAST CONFIDENCE REMAINS VERY LOW AS MODEL CONTINUITY IS EVEN WORSE...AND MODEL AGREEMENT LOWER...THAN THIS TIME YESTERDAY. IF THERE IS A TREND TO PICK UP ON OVER THE LAST FEW DAYS IT IS A WEAKENING ONE. THE GFS SHOWS THIS MORE THAN OTHER MODELS...ONLY DEEPENING THE SFC LOW FROM 1012MB TO 1007MB AS IT MOVES ACROSS THE CENTER OF THE CWA. NOT ONLY IS INTENSITY OF THE SYSTEM IN QUESTION...THE TRACK OF THE SYSTEM IS CONSIDERABLY UNCERTAIN. MODELS VARY FROM MOVING THE LOW TO THE N OF LAKE SUPERIOR...TO MOVING IT ALONG THE SE PERIPHERY OF THE CWA. TRACK VARIABILITY WILL PLAY ONE OF THE LARGEST ROLES IN PRECIP AMOUNTS...SINCE THE MOST PRECIP WILL BE IN THE COMMA SECTION OF THE SYSTEM. REGARDLESS OF THE PATH OF THE SYSTEM...THERE SHOULD STILL BE SOME GALES ON THE BACK SIDE OF THE LOW GIVEN A GOOD PRESSURE GRADIENT AND COLD AIR MOVING IN. MODELS AGREE A LITTLE BETTER ON DETAILS RELATED TO THE COLD AIR MOVING IN. BY 12Z FRI...850MB TEMPS LOOK TO BE AROUND -3C TO -5C WITH W TO NW LOW LEVEL FLOW. THE GFS IS FASTER THAN THE ECMWF WITH BRINGING IN A SECONDARY UPPER TROUGH...SO THE GFS BRINGS THE EVEN COLDER AIR IN FASTER. BY 00Z SAT THE GFS HAS 850MB TEMPS OF -6C TO -8C OVER MUCH OF THE CWA...WHILE THE ECMWF WAITS UNTIL AROUND 12Z SUN FOR THE SAME TEMPS. THESE TEMPS COMBINED WITH NW LOW LEVEL WINDS WILL LEAD TO LAKE EFFECT RAIN/SNOW THAT WILL BEGIN TO DIMINISH AFTER THE UPPER TROUGH PASSES...850MB TEMPS WARM AND SFC RIDGING PUSHES INTO THE CWA...WHETHER THAT BE LATE SAT OR MID DAY SUN. BEST CHANCES FOR SNOW LOOK TO BE OVER THE HIGHER TERRAIN OF WRN UPPER MI...PARTICULARLY OVER THE KEWEENAW PENINSULA WHERE THE GFS SUGGESTS POTENTIAL FOR AROUND 1 INCH OF SNOW. OVERNIGHT LOWS SHOULD BE AROUND OR JUST ABOVE FREEZING FRI NIGHT AND SAT NIGHT...WITH DAYTIME HIGHS IN THE LOW TO MID 40S...SO SIGNIFICANT ACCUMULATIONS OF SNOW WOULD BE MORE LIMITED TO GRASSY SURFACES AND WOULD NOT STICK AROUND TOO LONG. FOR SUN AND MON...TEMPS SHOULD BE WARMER AS SW-W LOW LEVEL FLOW BRINGS WARMER AIR OVERHEAD. THERE IS A LOT OF UNCERTAINTY THIS FAR OUT SO JUST USED CONSENSUS OF MODELS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 123 AM EDT TUE OCT 2 2012 ALTHOUGH SOME SHALLOW GROUND FOG MIGHT IMPACT IWD EARLY THIS MRNG... EXPECT PREVAILING VFR CONDITIONS THERE AND AT CMX THIS FCST PERIOD AS HI PRES RDG/DRY AIRMASS TO THE W MOVES INTO THE UPR LKS. AT SAW... THE UPSLOPE N FLOW IN ADVANCE OF THE HI PRES RDG WL BRING MVFR CIGS THRU SUNRISE BEFORE THE ARRIVAL OF THE RDG BREAKS UP THIS LO CLD AND BRINGS VFR CONDITIONS THE REST OF THE FCST PERIOD. NOT OUT OF THE QUESTION THERE COULD ALSO BE A PERIOD OF IFR CONDITIONS AT SAW THIS MRNG...BUT UPSTREAM OBS INDICATE THE INCOMING AIRMASS IS TOO DRY TO MAKE THESE CONDITIONS LIKELY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 545 AM EDT TUE OCT 2 2012 HIGH PRESSURE BUILDING INTO THE REGION TODAY WILL BRING DIMINISHING WINDS. WINDS WILL STAY AT OR BELOW 20 KNOTS INTO THURSDAY BEFORE THE PRESSURE GRADIENT TIGHTENS AS A STRONG LOW PRESSURE SYSTEM LIFTS INTO NORTHERN ONTARIO AND BRINGS WEST GALES THURSDAY NIGHT INTO FRIDAY. THERE IS SOME UNCERTAINTY WITH THE TRACK AND STRENGTH OF THE LOW BUT HIGHER END GALES TO 45 KNOTS MAY BE POSSIBLE OVER THE WEST AND NORTH CENTRAL PORTIONS OF THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...KC MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
329 PM MDT TUE OCT 2 2012 .SHORT TERM...VALID FOR WED AND THU... BIG CHANGES IN OUR WEATHER COMING TOMORROW. WILL MAKE NO CHANGES TO CURRENT RED FLAG WARNING IN EFFECT. WEST TO NORTHWEST WINDS HAVE INCREASED ESPECIALLY IN WEST AND CENTRAL PARTS...WITH WIDESPREAD GUSTS IN THE 20S TO MID 30S MPH. WITH ENHANCED PREFRONTAL MIXING TEMPS HAVE RISEN INTO THE 70S TO LOWER 80S...THUS HUMIDITY HAS FALLEN INTO THE MID TEENS TO LOW 20S MOST PLACES. WINDS WILL DIE DOWN AS HUMIDITY BEGINS TO CLIMB AFTER SUNSET. WATER VAPOR IMAGERY SHOWS APPROACHING SHORTWAVE OF INTEREST ALONG THE BC/ALBERTA BORDER AND PUSHING SOUTHWARD. THIS IS OUR WEATHER MAKER FOR TOMORROW. LATEST RUC ANALYSIS SHOWS A CLOSED 500MB CIRCULATION OVER THE CANADIAN ROCKIES...A BIT STRONGER THAN THE GFS OR NAM AT THIS POINT...SO THIS BEARS WATCHING. STRONG ASCENT SET TO ARRIVE EARLY TOMORROW MORNING. IN THE MEANTIME...COLD FRONT ITSELF IS NEARING THE CANADA/MT BORDER NOW...AND IT WILL PASS THROUGH OUR AREA LATE TONIGHT. COULD BE A FEW SHOWERS OR EVEN THUNDERSTORMS NEAR SFC TROF IN SOUTHEAST MONTANA WITH SOME ELEVATED INSTABILITY/WEAK LOW LEVEL JET...BUT OTHERWISE PCPN WILL BE POST FRONTAL BEGINNING EARLY TOMORROW. HAVE ADJUSTED TONIGHTS POPS TO SHOW LOWER CHANCES ESPECIALLY WEST AND CENTRAL PARTS. PASSAGE OF WAVE TOMORROW WILL GIVE US OUR GREATEST CHANCE OF PCPN IN QUITE SOME TIME...BUT THERE ARE ISSUES TO BE WORKED OUT. PER TRACK OF SHORTWAVE AND UPSLOPE FLOW...BEST CHANCES/HIGHEST PCPN AMOUNTS SHOULD BE ALONG OUR NORTH SLOPES AND ACROSS OUR EAST... WITH SOME DOWNSLOPING EXPECTED SOUTH OF THE SNOWIES/BELTS...BUT HIGH POPS WARRANTED EVERYWHERE. IF THE LOW TRACKS A BIT FURTHER WEST AND SOUTH...OUR PCPN CHANCES WOULD BE ENHANCED PER LONGER DURATION OF MOIST UPSLOPE FLOW/ASCENT...BUT ALL MODELS SHOW IT OPENING UP WEDNESDAY WITH STRONG RIDGE REMAINING OVER THE GREAT BASIN AND CENTRAL ROCKIES...SO WILL STAY THE COURSE HERE. OTHER ISSUE IS TEMPERATURE. LOOKING UPSTREAM...POST FRONTAL DEWPTS ACROSS ALBERTA ARE LARGELY IN THE 30S...SUGGESTING WET BULB TEMPS WILL REMAIN TOO HIGH FOR SNOW ACCUMULATION ACROSS OUR LOWER ELEVATIONS. THIS INCLUDES BILLINGS...WHICH WITH DEWPTS IN THE MID 30S EXPECTED MAY SEE ONLY RAIN. THAT BEING SAID...THE NORTH SLOPES OF THE BEARTOOTHS AND BIG HORNS...INCLUDING RED LODGE...AND THE HIGHER RIDGES SUCH AS THE WOLF MTNS AND LAME DEER DIVIDE...MAY SEE SOME WET SNOW ACCUMULATION BEGINNING WEDNESDAY MORNING AND LASTING INTO THE AFTERNOON. WILL HOLD OFF ON AN ADVISORY FOR RED LODGE AS SNOW ACCUMULATION MAY BE LIMITED IF THE WAVE PROVES TO BE MORE PROGRESSIVE... BUT THERE WILL BE AT LEAST A LITTLE ACCUMULATION HERE. OVERALL TEMPS WILL BE MUCH BELOW NORMAL WITH HIGHS ONLY IN THE 40S. SYSTEM WILL WIND DOWN TOMORROW NIGHT...AND A COUPLE HARD FREEZES IN STORE FOR MUCH OF THE REGION BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT. CANNOT RULE OUT SOME LIGHT RAIN/SNOW SHOWERS ON THURSDAY PER THE CYCLONIC FLOW AND ENOUGH LINGERING MOISTURE AND LOW LEVEL INSTABILITY...THOUGH NOT MUCH IN THE WAY OF DYNAMICS. NEXT SHORTWAVE...CURRENTLY IN THE GULF OF ALASKA...SHOULD ENHANCE OUR PCPN CHANCES BEGINNING THURSDAY NIGHT. WITH COLD AIR ALREADY IN PLACE...PCPN TYPE IS A MUCH EASIER QUESTION TO ANSWER AND SHOULD BE SNOW. GREATEST FRONTOGENESIS AND UPSLOPE FLOW ACROSS OUR SOUTH SHOULD FAVOR THIS AREA. THIS WOULD INCLUDE RED LODGE AND SHERIDAN. JKL .LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE... BROAD CYCLONIC FLOW CONTINUES TO DOMINATE THE WEATHER PATTERN THROUGH THE EXTENDED PERIOD. PREVAILING NORTHWESTERLY FLOW ALOFT WILL BRING DAYTIME TEMPS WELL BELOW NORMAL AND SOME OVERNIGHT LOWS THAT COULD APPROACH RECORD LOW TEMPS. A COUPLE OF GOOD SYSTEMS ROTATE THROUGH REGION TO START AND END THE PERIOD...WITH WEAKER WAVES IN BETWEEN. MADE A FEW CHANGES...MAINLY TO CONTINUES DOWNWARD TREND OF TEMPS AT THE BEGINNING OF THE PERIOD. THE MODELS CONTINUE TO COME TOGETHER...FAVORING A MORE WESTERLY TRACK...FOR THE PASSAGE OF A TROF ACROSS THE REGION FRIDAY. THE SYSTEM WILL BRING PRECIP POTENTIAL ACROSS THE MUCH OF THE REGION...BUT ESPECIALLY WEST AND SOUTH PORTIONS OF THE CWA. THIS SYSTEM WILL BE MUCH COLDER...WITH POTENTIAL RECORD LOWS AND ACCUMULATING SNOW. THE AIRMASS MODERATES SOME AFTER FRIDAY...WITH HIGHS TRENDING UP THROUGH THE REMAINDER OF THE PERIOD. CONDITIONS WILL DRY OUT AGAIN BEHIND THIS SYSTEM...SO HAVE KEPT POPS MAINLY CONFINED TO THE MOUNTAINS THROUGH MONDAY. THERE ARE A FEW WEAK SHORTWAVES INDICATED...BUT APPEARS THAT IT SHOULD DRY OUT TOO MUCH FOR ANYTHING OTHER THAN MOUNTAIN SHOWERS. ANOTHER SYSTEM IS TAKING SHAPE FOR THE END OF THE PERIOD...BUT THERE REMAINS A LOT OF UNCERTAINTY WITH MODELS DIFFERING SOMEWHAT ON TRACK AND TIMING OF THE SYSTEM. HAVE KEPT SLIGHT POPS IN PLACE BEGINNING MONDAY AS THE SYSTEM BEGINS PUSH INTO THE REGION. AAG && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. WEST TO SOUTHWEST WINDS CONTINUE TO INCREASE THIS MORNING IN THE LEE OF THE NORTHERN ROCKIES...WITH GUSTS TO 37 KNOTS IN KLVM. A COLD FRONT WILL PUSH THROUGH THE REGION YET THIS EVENING...SWITCHING WINDS TO A NORTH TO NORTHWESTERLY DIRECTION AT ALL TAF SITES AND ACROSS ALL ROUTES...WITH GUSTS OVER 30 KTS POSSIBLE. PRECIP...WITH RAIN/SNOW MIX OVER THE HIGHER TERRAIN...WILL MOVE INTO THE REGION OVERNIGHT...RESULTING IN LOCALIZED IFR CONDITIONS DUE TO REDUCED VISIBILITY. AAG && .PRELIMINARY POINT TEMP/POPS... WED THU FRI SAT SUN MON TUE ----------------------------------------------------------- BIL 038/045 028/044 028/041 024/049 031/055 033/057 035/055 18/O 32/W 33/W 01/B 00/U 02/W 22/W LVM 033/045 025/041 026/037 018/044 024/053 026/056 029/055 17/O 42/W 43/J 11/B 01/B 12/W 23/W HDN 040/046 028/047 028/044 025/050 033/056 033/060 035/059 28/R 42/W 33/W 01/B 00/U 02/W 22/W MLS 041/047 030/046 030/045 026/049 033/053 034/058 034/057 38/R 42/W 22/W 00/B 11/B 12/W 22/W 4BQ 041/044 030/046 029/043 025/047 033/052 033/058 035/058 29/R 52/W 23/W 10/B 10/U 02/W 22/W BHK 041/044 030/044 030/043 025/046 031/052 033/055 032/054 59/R 52/W 23/W 00/U 11/B 12/W 22/W SHR 039/043 028/042 028/039 022/045 029/053 030/055 031/054 28/O 42/W 53/W 21/B 00/U 01/B 22/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR ZONES 117-123>133. WY...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR ZONES 274-284. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
930 PM CDT WED OCT 3 2012 .UPDATE... UPDATED FORECAST TO CANCEL RED FLAG WARNING AND TO REFINE LOWS AND WINDS TONIGHT. STRONG PRESSURE RISES BEHIND THE FRONT THAT PASSED THROUGH THE AREA THIS EVENING...ON THE ORDER OF 6-8 MB PER 3 HRS. SECONDARY SURGE WITH SUBSIDENCE ASSOCIATED WITH BACK SIDE OF MID LEVEL FGEN CIRCULATION WAS CREATING BRIEF PERIOD OF INCREASED WIND GUSTS TO NEAR WIND ADVISORY CRITERIA BUT BELIEVE THIS IS A SHORT LIVED AND PROGRESSIVE FEATURE SO LONG TERM WIND ADVISORY CRITERIA IS NOT EXPECTED OVERNIGHT...BUT IT WILL REMAIN WINDY. WITH THE STRONG COLD AIR ADVECTION DID TRIM LOWS A FEW DEGREES IN THE FAR ERN ZONES BUT FOR THE MOST PART THE MINIMUM TEMP FCST LOOKED GOOD AS IT WAS. && .PREV DISCUSSION... /ISSUED 638 PM CDT WED OCT 3 2012/ AVIATION... 00Z TAFS FOR KLBF AND KVTN. SFC COLD FRONT HAS PASSED THROUGH CWA AND STRONG NORTH WINDS ARE THE RULE BEHIND THE FRONT. SFC PRESSURE RISE OF 5 TO 6 MB HAS ALLOWED FRONT TO MAKE QUICK PROGRESS THROUGH THE AREA. INITIAL SURGE IMMEDIATELY BEHIND THE FRONT PUSHED WINDS BRIEFLY TO GUSTS 40 TO 50 MPH AND FCST SOUNDINGS FROM THE RAP SUGGEST THAT WINDS GUSTS TO 35 TO 40 WILL CONTINUE FOR A COUPLE HOURS BEHIND THE FRONT BEFORE DROPPING SOMEWHAT OVERNIGHT...THOUGH GUSTS REMAINING ABOVE 25KTS. UPRIGHT FRONTAL CIRCULATION AND ASSOCIATED MID LEVEL ISENTROPIC LIFT CONTRIBUTING TO AN AREA OF GLACIATED MID CLOUDS MAINLY SOUTH OF KLBF THIS EVENING. STRONG DRY AIR ENTRAINMENT AND INCREASING SUBSIDENCE WILL ALLOW CLOUDS TO CONTINUE TO SAG SWD THROUGH THE EVENING. HOWEVER...LOW LEVEL CLOUDS WILL BE INCREASING FROM THE NORTHWEST AS THE STRONG COLD AIR ADVECTION CONTINUES TO PUSH SOUTH...SO MVFR CONDITIONS SHOULD ENCOMPASS MOST OF THE AREA BY 06Z. DEVELOPING SLOPING FRONTOGENETICAL CIRCULATION AS INDICATED IN NAM/RAP CROSS SECTIONS THIS EVENING AND OVERNIGHT WILL ALLOW AN ADDITIONAL AREA OF MID CLOUDS TO DEVELOP OVER THE MORE SHALLOW LOW LEVEL CLOUDS BUT SIGNIFICANT DRY AIR IN BETWEEN CLOUD LEVELS SHOULD PRECLUDE MUCH IN THE WAY OF PRECIP THIS EVENING AND OVERNIGHT. THIS GOOD MIXING WILL ALSO ALLOW WINDS TO STAY UP OVERNIGHT. SHORTLY AFTER SUNRISE...STRONG SUBSIDENCE WILL DISSIPATE THE MVFR CIGS MOST AREAS BY 17-19Z OR SO. HOWEVER...SC LAYER SHOULD REMAIN FOR THE AFTERNOON IN THE KVTN TAF. PREV DISCUSSION... /ISSUED 343 PM CDT WED OCT 3 2012/ SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT. STRONG COLD FRONT WILL MAKE IT/S WAY THROUGH ALL OF WESTERN AND NORTH CENTRAL NEBRASKA EARLY THIS EVENING. THERE MAY BE A LIGHT SHOWER OR TWO BEHIND THE FRONT...BUT CHANCES ARE SLIM AS BETTER JET DYNAMICS STAY TO THE NORTH. OTHERWISE A GUSTY NORTHWEST WIND...BRIEFLY NEAR WIND ADVISORY LEVELS...ARE EXPECTED RIGHT BEHIND THE FRONT THIS EVENING. A BREEZY AND CHILLY DAY IS EXPECTED THURSDAY. SKIES WILL CLEAR SOME...AND SUNSHINE SHOULD HELP BOOST TEMPS INTO THE 50S. EARLY EVENING CLEAR SKIES WILL ALLOW TEMPERATURES TO DROP INTO THE UPPER 20S THURSDAY EVENING. TEMPERATURES WILL STEADY OUT...OR ACTUALLY RISE A DEGREE OR TWO BY MORNING AS CLOUDS INCREASE WITH THE APPROACH OF THE NEXT DISTURBANCE. THIS DISTURBANCE WILL DROP SOUTHEAST THROUGH THE AREA FRIDAY...AND A NICE JET STREAK WILL DEVELOP ACROSS COLORADO AND THEN SPREAD EAST OVER NORTHERN KANSAS THROUGH FRIDAY NIGHT. OUR AREA WILL BE IN THE FAVORABLE DIVERGENT AREA MOST OF THE DAY FRIDAY...AND WHEN COMBINED WITH DECENT ISENTROPIC UPGLIDE...THE RESULT SHOULD BE A BAND OF PRECIPITATION. BEST INDICATIONS AT THIS TIME WOULD PLACE THE HEAVIEST PART OF THE BAND ACROSS SHERIDAN COUNTY...SOUTHEAST TOWARD THE MULLEN AREA FRIDAY MORNING. THIS BAND WILL THEN SHIFT SOUTH AND WEAKEN SLIGHTLY DURING THE AFTERNOON. WILL INTRODUCE LIKELY POPS ACROSS SHERIDAN COUNTY FRIDAY MORNING...AND DECREASE TO HIGH CHANCE DURING THE AFTERNOON. MAY SEE UP TO AN INCH OF SLUSHY WET SNOW ACROSS SHERIDAN COUNTY FRIDAY MORNING...WITH LITTLE ACCUMULATION ELSEWHERE. THE LIGHT PRECIPITATION WILL SETTLE INTO FAR SOUTHWEST NEBRASKA AND THE SOUTHERN NEBRASKA PANHANDLE FRIDAY NIGHT. KEPT TEMPS UP SLIGHTLY FRIDAY NIGHT WITH THE EXPECTED CLOUD COVER. LONG TERM...SATURDAY THROUGH WEDNESDAY. THE LAST IN A SERIES OF STRONG UPPER LEVEL DISTURBANCES WILL DROP SOUTHEAST ACROSS THE NORTHERN AND CENTRAL PLAINS SATURDAY. EXPECT QUITE A BIT OF CLOUD COVER ASSOCIATED WITH THIS DISTURBANCE...AS H7 TO H5 LAYER RELATIVE HUMIDITY IS PROGGED TO BE IN THE 80 TO 90 PERCENT RANGE DURING THE DAY. SOME WEAK ISENTROPIC UPGLIDE IS NOTED FROM SOUTHWEST NEBRASKA INTO THE SOUTHERN PANHANDLE...AND SLIGHT CHANCES FOR PRECIPITATION WILL BE CONTINUED IN THESE AREAS. SKIES SHOULD CLEAR SATURDAY NIGHT...AND AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA...COLD TEMPERATURES WILL RESULT. A KILLING FREEZE IS LIKELY FOR MOST IF NOT ALL OF WESTERN AND NORTH CENTRAL NEBRASKA. A BRIEF WARM UP WILL DEVELOP SUNDAY INTO MONDAY AHEAD OF ANOTHER COLD FRONT THAT WILL ARRIVE TUESDAY. FIRE WEATHER...ABNORMALLY WARM TEMPERATURES HAVE COMBINED WITH GUSTY WIND...A DRY ANTECEDENT AIRMASS AND FUELS THAT HAVE BEEN DECIMATED BY RECORD DROUGHT TO CREATE CONDITIONS FAVORABLE FOR EXTREME FIRE GROWTH. A COLD FRONT IS ON SCHEDULE FOR ARRIVAL LATE THIS AFTERNOON...BRINGING A DISTINCT WIND SHIFT...AND EVENTUALLY COOLER TEMPERATURES/HIGHER RELATIVE HUMIDITY. MODEL GUIDANCE HAS STRUGGLED WITH THE TIMING OF THIS FRONT...BUT BASED OFF OF LATEST RUNS...THE FRONT WILL BE SOUTH OF VALENTINE BY 20Z...AND THROUGH NORTH PLATTE AROUND 00Z. WIND SPEEDS WILL INCREASE SIGNIFICANTLY BEHIND THE FRONTAL PASSAGE...WITH GUSTS FROM THE NORTHWEST AT OR ABOVE 35 MPH THIS EVENING...FIRE SPREAD POTENTIAL WILL REMAIN HIGH THROUGH MID EVENING...THEN THE COOLER TEMPERATURES WILL ALLOW FOR HIGHER RH. LOOKING AHEAD...LIGHT PRECIPITATION...EITHER RAIN OR SNOW IS LOOKING PROBABLE FOR LATE THIS WEEK. UNFORTUNATELY...ACCUMULATIONS WILL BE LIGHT...BUT AT LEAST THE COOLER TEMPERATURES...AND HIGHER RH WILL HELP DIMINISH THE FIRE THREAT. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...JWS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
638 PM CDT WED OCT 3 2012 .AVIATION... 00Z TAFS FOR KLBF AND KVTN. SFC COLD FRONT HAS PASSED THROUGH CWA AND STRONG NORTH WINDS ARE THE RULE BEHIND THE FRONT. SFC PRESSURE RISE OF 5 TO 6 MB HAS ALLOWED FRONT TO MAKE QUICK PROGRESS THROUGH THE AREA. INITIAL SURGE IMMEDIATELY BEHIND THE FRONT PUSHED WINDS BRIEFLY TO GUSTS 40 TO 50 MPH AND FCST SOUNDINGS FROM THE RAP SUGGEST THAT WINDS GUSTS TO 35 TO 40 WILL CONTINUE FOR A COUPLE HOURS BEHIND THE FRONT BEFORE DROPPING SOMEWHAT OVERNIGHT...THOUGH GUSTS REMAINING ABOVE 25KTS. UPRIGHT FRONTAL CIRCULATION AND ASSOCIATED MID LEVEL ISENTROPIC LIFT CONTRIBUTING TO AN AREA OF GLACIATED MID CLOUDS MAINLY SOUTH OF KLBF THIS EVENING. STRONG DRY AIR ENTRAINMENT AND INCREASING SUBSIDENCE WILL ALLOW CLOUDS TO CONTINUE TO SAG SWD THROUGH THE EVENING. HOWEVER...LOW LEVEL CLOUDS WILL BE INCREASING FROM THE NORTHWEST AS THE STRONG COLD AIR ADVECTION CONTINUES TO PUSH SOUTH...SO MVFR CONDITIONS SHOULD ENCOMPASS MOST OF THE AREA BY 06Z. DEVELOPING SLOPING FRONTOGENETICAL CIRCULATION AS INDICATED IN NAM/RAP CROSS SECTIONS THIS EVENING AND OVERNIGHT WILL ALLOW AN ADDITIONAL AREA OF MID CLOUDS TO DEVELOP OVER THE MORE SHALLOW LOW LEVEL CLOUDS BUT SIGNIFICANT DRY AIR IN BETWEEN CLOUD LEVELS SHOULD PRECLUDE MUCH IN THE WAY OF PRECIP THIS EVENING AND OVERNIGHT. THIS GOOD MIXING WILL ALSO ALLOW WINDS TO STAY UP OVERNIGHT. SHORTLY AFTER SUNRISE...STRONG SUBSIDENCE WILL DISSIPATE THE MVFR CIGS MOST AREAS BY 17-19Z OR SO. HOWEVER...SC LAYER SHOULD REMAIN FOR THE AFTERNOON IN THE KVTN TAF. && .PREV DISCUSSION... /ISSUED 343 PM CDT WED OCT 3 2012/ SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT. STRONG COLD FRONT WILL MAKE IT/S WAY THROUGH ALL OF WESTERN AND NORTH CENTRAL NEBRASKA EARLY THIS EVENING. THERE MAY BE A LIGHT SHOWER OR TWO BEHIND THE FRONT...BUT CHANCES ARE SLIM AS BETTER JET DYNAMICS STAY TO THE NORTH. OTHERWISE A GUSTY NORTHWEST WIND...BRIEFLY NEAR WIND ADVISORY LEVELS...ARE EXPECTED RIGHT BEHIND THE FRONT THIS EVENING. A BREEZY AND CHILLY DAY IS EXPECTED THURSDAY. SKIES WILL CLEAR SOME...AND SUNSHINE SHOULD HELP BOOST TEMPS INTO THE 50S. EARLY EVENING CLEAR SKIES WILL ALLOW TEMPERATURES TO DROP INTO THE UPPER 20S THURSDAY EVENING. TEMPERATURES WILL STEADY OUT...OR ACTUALLY RISE A DEGREE OR TWO BY MORNING AS CLOUDS INCREASE WITH THE APPROACH OF THE NEXT DISTURBANCE. THIS DISTURBANCE WILL DROP SOUTHEAST THROUGH THE AREA FRIDAY...AND A NICE JET STREAK WILL DEVELOP ACROSS COLORADO AND THEN SPREAD EAST OVER NORTHERN KANSAS THROUGH FRIDAY NIGHT. OUR AREA WILL BE IN THE FAVORABLE DIVERGENT AREA MOST OF THE DAY FRIDAY...AND WHEN COMBINED WITH DECENT ISENTROPIC UPGLIDE...THE RESULT SHOULD BE A BAND OF PRECIPITATION. BEST INDICATIONS AT THIS TIME WOULD PLACE THE HEAVIEST PART OF THE BAND ACROSS SHERIDAN COUNTY...SOUTHEAST TOWARD THE MULLEN AREA FRIDAY MORNING. THIS BAND WILL THEN SHIFT SOUTH AND WEAKEN SLIGHTLY DURING THE AFTERNOON. WILL INTRODUCE LIKELY POPS ACROSS SHERIDAN COUNTY FRIDAY MORNING...AND DECREASE TO HIGH CHANCE DURING THE AFTERNOON. MAY SEE UP TO AN INCH OF SLUSHY WET SNOW ACROSS SHERIDAN COUNTY FRIDAY MORNING...WITH LITTLE ACCUMULATION ELSEWHERE. THE LIGHT PRECIPITATION WILL SETTLE INTO FAR SOUTHWEST NEBRASKA AND THE SOUTHERN NEBRASKA PANHANDLE FRIDAY NIGHT. KEPT TEMPS UP SLIGHTLY FRIDAY NIGHT WITH THE EXPECTED CLOUD COVER. LONG TERM...SATURDAY THROUGH WEDNESDAY. THE LAST IN A SERIES OF STRONG UPPER LEVEL DISTURBANCES WILL DROP SOUTHEAST ACROSS THE NORTHERN AND CENTRAL PLAINS SATURDAY. EXPECT QUITE A BIT OF CLOUD COVER ASSOCIATED WITH THIS DISTURBANCE...AS H7 TO H5 LAYER RELATIVE HUMIDITY IS PROGGED TO BE IN THE 80 TO 90 PERCENT RANGE DURING THE DAY. SOME WEAK ISENTROPIC UPGLIDE IS NOTED FROM SOUTHWEST NEBRASKA INTO THE SOUTHERN PANHANDLE...AND SLIGHT CHANCES FOR PRECIPITATION WILL BE CONTINUED IN THESE AREAS. SKIES SHOULD CLEAR SATURDAY NIGHT...AND AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA...COLD TEMPERATURES WILL RESULT. A KILLING FREEZE IS LIKELY FOR MOST IF NOT ALL OF WESTERN AND NORTH CENTRAL NEBRASKA. A BRIEF WARM UP WILL DEVELOP SUNDAY INTO MONDAY AHEAD OF ANOTHER COLD FRONT THAT WILL ARRIVE TUESDAY. FIRE WEATHER...ABNORMALLY WARM TEMPERATURES HAVE COMBINED WITH GUSTY WIND...A DRY ANTECEDENT AIRMASS AND FUELS THAT HAVE BEEN DECIMATED BY RECORD DROUGHT TO CREATE CONDITIONS FAVORABLE FOR EXTREME FIRE GROWTH. A COLD FRONT IS ON SCHEDULE FOR ARRIVAL LATE THIS AFTERNOON...BRINGING A DISTINCT WIND SHIFT...AND EVENTUALLY COOLER TEMPERATURES/HIGHER RELATIVE HUMIDITY. MODEL GUIDANCE HAS STRUGGLED WITH THE TIMING OF THIS FRONT...BUT BASED OFF OF LATEST RUNS...THE FRONT WILL BE SOUTH OF VALENTINE BY 20Z...AND THROUGH NORTH PLATTE AROUND 00Z. WIND SPEEDS WILL INCREASE SIGNIFICANTLY BEHIND THE FRONTAL PASSAGE...WITH GUSTS FROM THE NORTHWEST AT OR ABOVE 35 MPH THIS EVENING...FIRE SPREAD POTENTIAL WILL REMAIN HIGH THROUGH MID EVENING...THEN THE COOLER TEMPERATURES WILL ALLOW FOR HIGHER RH. LOOKING AHEAD...LIGHT PRECIPITATION...EITHER RAIN OR SNOW IS LOOKING PROBABLE FOR LATE THIS WEEK. UNFORTUNATELY...ACCUMULATIONS WILL BE LIGHT...BUT AT LEAST THE COOLER TEMPERATURES...AND HIGHER RH WILL HELP DIMINISH THE FIRE THREAT. && .LBF WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR NEZ204-206-208>210-219. && $$ AVIATION...JWS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1254 AM CDT TUE OCT 2 2012 .AVIATION...06Z KGRI TAF. SATELLITE IMAGERY SHOWS CLEAR SKIES ACROSS THE CENTRAL PLAINS AND THIS WILL CONTINUE TO BE THE CASE THROUGH THE TAF VALID PERIOD. THE WIND WILL REMAIN LIGHT AND GRADUALLY SHIFT FROM NORTHWEST EARLY THIS MORNING TO SOUTHWEST BY NOON AND THEN SOUTHERLY BY MID TO LATE AFTERNOON. && .PREV DISCUSSION... /ISSUED 948 PM CDT MON OCT 1 2012/ UPDATE...SURFACE ANALYSIS AS OF 02Z INDICATES A ~1020MB HIGH NEAR KTIF AND MOVING SOUTHEAST. THE LOW LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE NORTHWEST AS A RESULT...WITH WIND INTENSITY CONTINUING TO DECREASE THROUGH THE PAST FEW HOURS. SHORT TERM GUIDANCE FROM THE NAM AND RAP SUGGEST THIS SURFACE HIGH WILL CONTINUE MOVING SOUTHEAST TONIGHT...EVENTUALLY SETTING UP SHOP OVER WESTERN PORTIONS OF OUR AREA BY SUNRISE TUESDAY. THE PRESENCE OF THIS SURFACE HIGH WILL PRESENT A COOL AIRMASS TO THE AREA TONIGHT...AND WITH THE LOW LEVEL WIND FIELD BECOMING VERY LIGHT AND SKIES REMAINING CLEAR...THE LOW LEVEL AIRMASS WILL RADIATE OUT VERY EFFICIENTLY WHICH WILL LIKELY RESULT IN OVERNIGHT TEMPERATURE DROP-OFFS OF 35-40 DEGREES. WITH LATE AFTERNOON TEMPERATURES ON MONDAY TOPPING OUT IN THE UPPER 60S TO NEAR 70...OVERNIGHT LOWS GENERALLY IN THE LOW TO MID 30S SEEM REASONABLE FOR MOST LOCATIONS...WITH PERHAPS SOMEWHAT WARMER LOWS FOR LOCATIONS WELL AHEAD OF THE SURFACE HIGH ACROSS SOUTHEASTERN PORTIONS OF THE CWA. LOWS OF THIS MAGNITUDE ARE ALSO SUGGESTED MY MANY SETS OF GUIDANCE...WITH THE EXCEPTION OF THE USUALLY COOLER NAM/MET GUIDANCE...WHICH PLUMMETS OVERNIGHT LOWS CLOSER TO 30 ACROSS OUR NORTHWEST. SEEING AS THOUGH MOST GUIDANCE KEEPS OUR TEMPERATURES CLOSER TO THE MID 30S TONIGHT...WILL PLAY SLIGHTLY WARMER THAN NAM/MET GUIDANCE FOR THIS UPDATE...BUT STILL KEEP TEMPERATURES CLOSER TO 33 THROUGH RIVER VALLEYS ACROSS OUR WESTERN CWA...AS WELL AS NORTHERN PORTIONS OF THE CWA NEAR KODX WHICH ALWAYS SEEMS TO TANK IN SITUATIONS SUCH AS THIS. ALTHOUGH NOT CURRENTLY FORECAST...IT IS CONCEIVABLE A FEW LOCATIONS COULD NEAR 30 AS NAM/MET GUIDANCE SUGGESTS...BUT IT IS CURRENTLY BELIEVED THESE LOCATIONS WILL BE FEW AND FAR IN BETWEEN AND MOSTLY RELEGATED TO THE AFOREMENTIONED RIVER VALLEYS AND NORTHERN PORTIONS OF THE AREA. GIVEN THIS...OPTED TO STAY AWAY FROM ANY FREEZE HEADLINES FOR TONIGHT. DID CONTEMPLATE GOING WITH A FROST ADVISORY TONIGHT AND ALTHOUGH THE LATEST UPDATE CALLS FOR A FEW LOCATIONS TO FALL TO 33 OR 34 DEGREES...IT IS CURRENTLY BELIEVED MOST LOCATIONS WILL HOVER CLOSER TO 35 OR 36 DEGREES...THUS KEEPING FROST DEVELOPMENT ON THE PATCHY SIDE AND AGAIN...MOSTLY RELEGATED TO THE RIVER VALLEYS AND PERHAPS POINTS FARTHER NORTH ACROSS THE AREA. SO...NO HEADLINES FOR TONIGHT...BUT DID FRESHEN UP THE FROST WORDING IN THE HWO. ONLY REAL CHANGES TO THE FORECAST WERE TO TWEAK OVERNIGHT LOWS AND THE PLACEMENT OF PATCHY FROST IN THE GRIDS...MORE OR LESS COSMETIC CHANGES TO BETTER MATCH WHERE THE CURRENT OBS ARE HEADING. PREV DISCUSSION... /ISSUED 401 PM CDT MON OCT 1 2012/ SHORT TERM...THROUGH TUESDAY EVENING...QUIET WEATHER IS EXPECTED THROUGH THE SHORT TERM AS SKIES WILL CONTINUE TO CLEAR BEHIND THIS MORNINGS COLD FRONT. EXPECT THE STRONG NORTHERLY WINDS ACROSS THE AREA THIS AFTERNOON TO GRADUALLY RELAX AROUND SUNSET...AS THE PRESSURE GRADIENT BEGINS TO WEAKEN IN RESPONSE TO AN AREA OF SURFACE HIGH PRESSURE BUILDING ACROSS THE CENTRAL PLAINS FROM THE NORTH. WITH THE EXPECTED CLEAR SKIES AND LIGHT WINDS OVERNIGHT...EXPECT GOOD RADIATIONAL COOLING ACROSS THE REGION BY EARLY TUESDAY MORNING...AND COULD SEE SOME PATCHY AREA OF FROST FORM IN LOW LYING AREAS AND ACROSS THE WEST AND NORTHERN PORTIONS OF THE FORECAST AREA. HOWEVER WITH VERY MARGINAL TEMPERATURES FOR FROST IN THE FORECAST...AND A VERY WIDE RANGE OF TEMPERATURES IN MODEL GUIDANCE...DECIDED AGAINST ANY FROST HEADLINES FOR EARLY TUESDAY MORNING AS CONFIDENCE IS LOW THAT THIS WILL BE ANYTHING OTHER THAN A VERY PATCHY FROST EVENT. OTHERWISE...A VERY NICE DAY IS EXPECTED ACROSS THE REGION ON TUESDAY...WITH LIGHT WINDS IN THE MORNING BECOMING SOUTHWESTERLY BY EARLY AFTERNOON. WITH SHORT WAVE RIDGING ALOFT...AS THE AREA REMAINS IN BETWEEN AN UPPER LEVEL LOW ACROSS THE SOUTHERN PLAINS AND THE NEXT TROUGH MOVING ACROSS THE PACIFIC NORTHWEST...EXPECT A MAINLY CLOUD FREE AFTERNOON WITH TEMPERATURES RETURNING TO NEAR SEASONAL NORMS LATER IN THE DAY. LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN LIES WITH PRECIPITATION CHANCES. THE START OF THE LONG TERM PERIOD...TUESDAY NIGHT THROUGH WEDNESDAY...SHOWS MODELS IN GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN ACROSS THE CONUS. DRY CONDITIONS ARE EXPECTED ACROSS THE CWA THROUGH THIS TIMEFRAME...AS THE CENTRAL PLAINS SIT UNDER A SW- NE ORIENTATED SHORTWAVE RIDGE AXIS...WITH LOW PRESSURE GRADUALLY SHIFTING INTO THE MIDWEST REGION...AND ANOTHER TROUGH SWINGING SE OUT OF WRN CANADA AND INTO THE NRN ROCKIES/PLAINS. DURING THE AFTERNOON HOURS ON WEDNESDAY...AND SURFACE COLD FRONT WILL BEGIN TO MAKE ITS WAY INTO THE CWA...PUSHED BY THAT TROUGH TO THE NW. THERE CONTINUE TO BE SOME TIMING DIFFERENCES BETWEEN THE MODELS...WITH THE NAM REMAINING ON THE QUICKER SIDE OF THING...AND THE ECMWF/GFS NOTABLY SLOWER. AT 00Z THURSDAY...THE NAM IS BASICALLY CLEARING THE SE CORNER OF THE CWA...WHERE THE EC/GFS ARE JUST GETTING MORE ESTABLISHED ACROSS THE NW CORNER. THESE TIMING DIFFERENCES COULD REALLY MESS UP THE FORECAST HIGH TEMPERATURES FOR WEDNESDAY...AND DID BUMP THEM A TOUCH FOR THIS PACKAGE. THINKING THAT WITH THE EVEN WITH THE QUICKER NAM PASSAGE...MIXING AHEAD OF THE FRONT LOOKS TO ALLOW TEMPS ACROSS THE SE HALF OF THE CWA TO REACH NEAR/INTO THE 80S. IF THE SLOWER GFS/EC IS CLOSER TO REALITY...WARMER TEMPS WOULD NEED TO BE EXPANDED FURTHER BACK NW INTO THE ODX/LXN AREA. WEDNESDAY NIGHT AND INTO MAINLY THE FIRST HALF OF THE DAY ON THURSDAY...PRECIPITATION CHANCES RETURN TO THE CWA. MODELS REMAIN IN FAIRLY GOOD AGREEMENT WITH THE TIMING OF THE BETTER CHANCES...AS FORCING INCREASES AHEAD OF THE MAIN SHORTWAVE TROUGH AXIS AND AS A 80-90KT UPPER LEVEL JET STREAK STARTS TO NOSE IN FROM THE WEST. DID UP POPS A BIT DURING THE OVERNIGHT HOURS...ALSO KEEPING THE BETTER CHANCES CONFINED TO THE 06-12Z PERIOD AND ACROSS OUR SC NEB COUNTIES. COULD SEE A FEW LINGERING SHOWERING INTO THE MORNING HOURS ON THURSDAY...BUT EXPECTING THAT THE AFTERNOON WILL BE DRYING OUT. EXPECTING SOME GUSTIER NORTHWEST WINDS BEHIND THE FRONT...BUT WITH THE TIMING DIFFERENCES...AT WHAT POINT IT STARTS IS A LITTLE UP IN THE AIR /COULD BE WED EVENING FROM THE NAM OR CLOSER TO 06Z FROM THE EC AND GFS/. EITHER WAY...EXPECTING THOSE GUSTY WINDS TO CONTINUE INTO THE DAYTIME HOURS THURSDAY...AND TEMPS WILL BE COOLER. FORECAST CURRENTLY CALLING FOR MID 50S IN THE NORTH TO LOWER 60S IN THE SOUTH. DRY CONDITIONS FORECAST TO CONTINUE THURSDAY NIGHT AND THOUGH THE DAY ON FRIDAY IN THE WAKE OF THIS TROUGH PASSAGE...BUT IT IS A SHORT BREAK AS ANOTHER DISTURBANCE TAKES AIM ON THE REGION. CONFIDENCE IN THE FRIDAY NIGHT AND SATURDAY PERIOD IS LOWER...AS SOME NOTABLE DIFFERENCE EXIST BETWEEN MODELS...AND DIDNT GET BETTER WITH THE 12Z RUN. INHERITED FORECAST HAD THE MAIN POPS COMING FRIDAY NIGHT AND INTO SATURDAY...AND KEPT THAT IN PLACE. THE PROBLEMS LIE WITH THE 12Z GFS COMING IN WEAKER/FASTER WITH THE NEXT TROUGH SWINGING THROUGH THE NRN/CENTRAL PLAINS...AND ACTUALLY DRIES EVERYTHING OUT BY 12Z SATURDAY...VS THE ECMWF WHICH IS A LITTLE SLOWER AND MUCH MORE AGGRESSIVE WITH THE AREAL COVERAGE OF ITS QPF. WAS FINE WITH ALLBLEND WHICH KEPT THINGS IN THE 30-40 PERCENT RANGE. ANOTHER COMPLICATING PIECE OF THE FORECAST THAT WILL NEED TO BE KEPT AN EYE ON IS THE PRECIPITATION TYPE. THE ECMWF IS STAYING ON THE COOLER SIDE OF THINGS ALONG WITH ITS SLOWER SOLUTION...WHICH WOULD LEAD TO THE POTENTIAL FOR SOME WET SNOW MIXING IN EARLY SATURDAY MORNING. DECIDED TO CONTINUE KEEPING THE SNOW OUT FOR NOW...WOULD LIKE TO SEE THE MODELS AT LEAST START TRENDING TOWARD ONE SOLUTION BEFORE INSERTING THE FIRST SNOW MENTION OF THE FALL SEASON. TEMPERATURE-WISE...IT IS GOING TO BE A COOL START TO THE WEEKEND...THE FORECAST CALLS FOR LOWER 50S...BUT IF THINGS STAY WITH/TREND TOWARD THE WETTER/SLOWER EC SOLUTION...MANY LOCATIONS WOULD STRUGGLE TO GET OUT OF THE 40S. BROAD UPPER LEVEL TROUGHING AND GENERALLY NORTHWESTERLY FLOW BEHIND THIS LATEST SYSTEM IS EXPECTED TO KEEP SUNDAY AND MONDAY DRY. WITH THE COOLER AIR MASS SHIFTING EAST...SUNNIER SKIES...AND MORE OF A DOWNSLOPING COMPONENT DEVELOPING TO THE WINDS...WILL SEE THE POTENTIAL FOR HIGH TEMPERATURES TO REBOUND BACK INTO THE 60S BY MONDAY. STILL BELOW AVERAGE FOR THIS TIME OF YEAR...BUT BETTER THAN THE 40S/50S POSSIBLE FOR SATURDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
210 PM EDT TUE OCT 2 2012 .SYNOPSIS... LOW PRESSURE OVER THE TENNESSEE RIVER VALLEY WILL LIFT NORTH INTO THE OHIO RIVER VALLEY THROUGH TODAY. THIS SYSTEM WILL BRING WARM TEMPERATURES WITH INCREASING CLOUDS AND A FEW SHOWERS FROM THIS MORNING THROUGH WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AREA RADARS SHOWING SCATTERED RAIN SHOWERS LIFTING NORTHEAST ACROSS THE REGION THIS MORNING. THESE SHOWERS HAVE FORMED ALONG THE NOSE OF A 30-35KT 850MB LOW LEVEL JET AS DISPLAYED ON THE 10Z RAP MODEL AND MESOANALYSIS. BOTH 00Z AND 06Z MODELS RUNS ARE TOO SLOW WITH MOVING THIS FIRST SHOW OF RAIN ACROSS NEW YORK THIS MORNING. DESPITE THE SCATTERED NATURE OF PRECIP ALL PARTS OF WESTERN NY SHOULD PICK UP A FEW HUNDREDTHS UPWARDS TO A TENTH OF AN INCH THIS MORNING. EVEN LOCATIONS EAST OF LAKE ONTARIO COULD MEASURE BEFORE NOON. MILD TEMPERATURES AREAWIDE RUNNING IN THE MID 50S TO START TUESDAY AS WARM ADVECTION CONTINUES TO WORK NORTH AHEAD OF SURFACE LOW CENTERED OVER THE TENNESSEE VALLEY. THE STRENGTHENING WARM AIR ADVECTION PATTERN IN ADVANCE OF THIS LOW WILL SPREAD INCREASING AMOUNTS OF MOISTURE AND LIFT NORTHWARD TOWARD OUR REGION. LATER TODAY...THE SURFACE LOW WILL CONTINUE A SLOW NORTHWARD TREK INTO THE OHIO VALLEY. CLOUDS WILL CONTINUE TO LOWER WITH INCREASE IN MOISTURE AND CHANCES FOR SHOWERS SPREADING A BIT FURTHER NORTH AND EAST. THE BEST LIKELIHOOD OF PRECIP APPEARS TO BE ALONG A SURFACE TROUGH/WIND SHIFT/LOW LEVEL JET WHICH IS FORECAST TO SHIFT NORTHEAST ACROSS THE REGION THROUGH TODAY IN ADVANCE OF SURFACE WARM FRONT. THIS KEEPS HIGHEST CHANCES FOR SOUTHERN TIER INTO SOUTHERN FINGER LAKES INTO CENTRAL NY. OTHERWISE...EXPECT A CLOUDY DAY ALONG WITH WARMER TEMPS...WITH THE SOUTHERLY WARM AIR ADVECTION PATTERN HELPING TO BOOST TEMPS INTO THE UPPER 60S/LOWER 70S IN SPITE OF THE CLOUDY SKIES. TONIGHT THE SURFACE LOW WILL BE CENTERED OVER THE OHIO VALLEY WITH A WARM FRONT EXTENDING EASTWARD TO THE DELMARVA. STILL EXPECT SOME SHOWERS TO BE MOVING THROUGH THE EASTERN LAKE ONTARIO REGION WITH A BRIEF DRY BUT CLOUDY PERIOD ACROSS WESTERN NEW YORK. THROUGH THE NIGHT THE LOW WILL WEAKEN AND RETROGRADE TO THE WEST OVER INDIANA AS IT GETS CAUGHT BENEATH THE UPPER TROUGH. ACROSS NEW YORK THE SURFACE WARM FRONT WILL BE SHIFTING NORTH OVERNIGHT. THIS WILL BE AN ADDITIONAL FOCUS FOR A SECOND ROUND OF RAIN SHOWERS OVERNIGHT. KEPT CHANCE POPS WITH SOME UNCERTAINTY ON STRENGTH OF THE FRONT. ANOTHER NIGHT OF MILD TEMPS IS EXPECTED WITH LOWS WELL ABOVE NORMAL. MANY SPOTS WILL NOT SEE LOWS DROP BELOW 60 WITH OTHER SPOTS SEEING UPPER 50S FOR LOWS. SKIES WILL REMAIN CLOUDY AND WINDS LIGHT. QPF THROUGH THE NEAR TERM PERIOD WILL RANGE FROM AROUND A THIRD OF AN INCH ACROSS THE SOUTHERN TIER TAPERING TO AROUND A TENTH OF AN INCH FROM KIAG TO KART. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AT THE START OF THE PERIOD ON WEDNESDAY...A WEAK MID LEVEL CLOSED LOW WILL CONTINUE TO LIFT SLOWLY INTO THE LOWER OHIO VALLEY...WHILE A STRONG DOWNSTREAM RIDGE WILL TAKE UP RESIDENCE JUST OFF THE SOUTHEAST COAST IN A CLASSIC BERMUDA HIGH POSITION. THIS WILL RESULT IN CONTINUED DEEP SOUTHERLY FLOW INTO THE LOWER LAKES REGION WITH TEMPS AND HUMIDITY BECOMING MORE REMINISCENT OF SUMMER. THE MID LEVEL CIRCULATION AND ASSOCIATED VORTICITY MAXIMA WILL REMAIN WELL SOUTHWEST OF THE REGION...WITH LITTLE IN THE WAY OF SYNOPTIC SCALE ASCENT APPARENT BESIDES A WEAK WARM FRONT LIFTING ACROSS LAKE ONTARIO AND THE NORTH COUNTRY IN THE MORNING. WARM ADVECTION AND WEAK ISENTROPIC UPGLIDE MAY PRODUCE A FEW SCATTERED SHOWERS WEDNESDAY MORNING WITH THE BEST COVERAGE LIKELY TO BE NEAR LAKE ONTARIO AND THE NORTH COUNTRY IN CLOSER PROXIMITY TO THE RETREATING WARM FRONT. BY AFTERNOON EXPECT WESTERN NY TO DRY OUT AS THE WARM SECTOR BECOMES ESTABLISHED. THE NAM AND TO SOME EXTENT THE GFS DEVELOP SOME CONVECTION IN THE AFTERNOON FROM THE INTERIOR SOUTHERN TIER INTO THE FINGER LAKES ALONG A WEAK CONVERGENCE ZONE. MODEST SBCAPE OF 500-800 J/KG SHOULD BE ENOUGH TO SUPPORT WIDELY SCATTERED CONVECTION. WHAT DOES FORM WILL LIFT NORTHEAST INTO CENTRAL NY AND THE EASTERN LAKE ONTARIO REGION LATER IN THE DAY AND THROUGH WEDNESDAY EVENING BEFORE ENDING FROM WEST TO EAST. WEDNESDAY WILL BE QUITE WARM AS DEEP SOUTHERLY FLOW PUMPS 850MB TEMPS UP TO AROUND +14C. EVEN WITH SOME CLOUD COVER THIS WILL STILL SUPPORT UPPER 70S IN MOST AREAS...WITH A FEW LOWER 80S POSSIBLE IN THE WARMER SPOTS. SURFACE DEWPOINTS ARE ALSO FORECAST TO RISE INTO THE MID 60S GIVING A SUMMER-LIKE FEEL TO THE AIR. WEDNESDAY EVENING ANY CONVECTION ACROSS CENTRAL NY AND THE NORTH COUNTRY WILL END WITH THE LOSS OF DAYTIME HEATING. A NARROW SURFACE RIDGE WILL THEN BUILD INTO THE REGION OVERNIGHT WITH AT LEAST PARTLY CLEAR SKIES. THE VERY WARM AIRMASS WILL BRING A MILD NIGHT WITH LOWS RANGING FROM THE UPPER 50S TO LOWER 60S ON THE LAKE PLAINS AND EAST OF LAKE ONTARIO AND LOW TO MID 50S ACROSS THE INTERIOR SOUTHERN TIER. ON THURSDAY THE OHIO VALLEY CLOSED LOW WILL OPEN UP AND ACCELERATE NORTHEAST ACROSS THE GREAT LAKES IN RESPONSE TO AN UPSTREAM KICKER SHORTWAVE. THE MID LEVEL TROUGH WILL QUICKLY DEAMPLIFY WITH TIME AND THE SURFACE TROUGH WILL LOSE DEFINITION. THE WEAKENING FORCING FOR ASCENT AND VERY LIMITED MOISTURE SHOULD ALLOW THE MID LEVEL TROUGH TO PASS WITH LITTLE FANFARE...WITH JUST A PERIOD OF MID LEVEL CLOUD COVER. ANY SHOWERS SHOULD REMAIN WELL NORTH ACROSS ONTARIO PROVINCE WHERE STRONGER ASCENT AND DEEPER MOISTURE WILL BE FOUND. IT WILL BE ANOTHER WARM DAY AHEAD OF THE TROUGH PASSAGE WITH HIGHS WELL INTO THE 70S IN MOST AREAS...AND POSSIBLY PUSHING 80 AGAIN ACROSS CENTRAL NY. THURSDAY NIGHT ANOTHER NARROW RIDGE BUILDS INTO THE LOWER LAKES WITH CLEARING SKIES. AGAIN THE AIRMASS WILL REMAIN QUITE MILD FOR THIS TIME OF YEAR...AND WINDS WILL NOT DECOUPLE WHICH WILL KEEP LOWS IN THE MID TO UPPER 50S IN MOST AREAS. CLOUDS WILL INCREASE FROM WEST TO EAST LATE AHEAD OF THE NEXT SYSTEM...BUT ANY RAIN SHOULD HOLD OFF UNTIL AROUND DAYBREAK FRIDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... THE LONGWAVE PATTERN WILL BECOME STRONGLY AMPLIFIED THROUGH THE LONG TERM PERIOD WITH A DEEP FULL LATITUDE TROUGH BECOMING ESTABLISHED FROM CENTRAL CANADA AND THE CENTRAL US TO THE APPALACHIANS... EVENTUALLY SPREADING TO THE EAST COAST BY DAY 6-7. UPSTREAM A STRONG RIDGE WILL DEVELOP INITIALLY OVER THE GULF OF ALASKA THEN PUSH EAST TO THE BRITISH COLUMBIA COAST BY DAY 7. THIS PATTERN AMPLIFICATION WILL SUPPORT A TURN TOWARDS MUCH BELOW NORMAL TEMPERATURES FOR THE GREAT LAKES THIS WEEKEND INTO EARLY NEXT WEEK. LOOKING AT THE DETAILS...ON FRIDAY AN INITIAL MID LEVEL LOW WILL SWING ACROSS NORTHWEST ONTARIO PROVINCE AND REACH JAMES BAY BY LATE IN THE DAY. AN ASSOCIATED STRONG SURFACE COLD FRONT WILL CROSS THE LOWER LAKES WITH A BRIEF PERIOD OF SHOWERS. THE LATEST 00Z MODEL GUIDANCE IS A LITTLE FASTER WITH THE FROPA...SO SHOWERS MAY COME DURING THE FIRST HALF OF THE DAY WITH FALLING TEMPS IN THE AFTERNOON. LATER FRIDAY NIGHT INTO THE WEEKEND VERY CHILLY AIR WILL BECOME ESTABLISHED FROM THE NORTHERN PLAINS INTO THE GREAT LAKES AND NEW ENGLAND. MODEL GUIDANCE CONTINUES TO STRUGGLE WITH THE HANDLING OF A POTENTIAL FRONTAL WAVE. LATEST 00Z GFS SHOWS A RATHER ROBUST FRONTAL WAVE RUNNING THROUGH THE LOWER LAKES LATE FRIDAY NIGHT INTO SATURDAY...WHICH WOULD BRING A WIDESPREAD CHILLY RAIN. THE 00Z ECMWF ALSO HAS A FRONTAL WAVE...JUST A LITTLE WEAKER AND ABOUT 6 HOURS SLOWER. IT ALSO TRIES TO DEVELOP A SECOND FRONTAL WAVE ON SUNDAY AS IT PHASES WITH ADDITIONAL NORTHERN STREAM ENERGY DIGGING INTO THE UPPER GREAT LAKES. GIVEN THE COMPLEXITY OF THE SCENARIO...IT WILL LIKELY BE SEVERAL DAYS BEFORE THE MODEL GUIDANCE SETTLES DOWN AND CONVERGES ON A COMMON SOLUTION. FOR NOW WILL SIMPLY USE CHANCE POPS BOTH DAYS. WHAT IS MUCH HIGHER CONFIDENCE IS THE BELOW NORMAL TEMPERATURES BEGINNING THIS WEEKEND...WITH HIGHS ONLY IN THE LOWER 50S BOTH DAYS ACROSS LOWER ELEVATIONS AND MID TO UPPER 40S ACROSS HIGHER TERRAIN. EVEN THIS MAY BE TOO WARM IF WIDESPREAD CLOUD COVER AND RAIN IS REALIZED. THE CLOUD COVER WILL KEEP OVERNIGHT LOWS ABOVE FREEZING FRIDAY NIGHT AND PROBABLY SATURDAY NIGHT AS WELL. THE COLDEST NIGHT WILL LIKELY BE SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE OHIO VALLEY AND LOWER LAKES WITH CLEARING SKIES AND LIGHTER WINDS. IF THE HIGH DOES INDEED SETTLE OVERHEAD...WIDESPREAD FROST/FREEZE CONDITIONS MAY BE ON THE WAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... JET STREAK MOVING ACROSS THE WESTERN PORTION OF THE FORECAST AREA...INTO LAKE ONTARIO AND ONWARD TO THE SAINT LAWRENCE VALLEY WILL INDUCE A SOUTHWEST TO NORTHEAST ORIENTED BAND OF RAIN SHOWERS. EXPECT MVFR VSBY AND IFR CIGS IN THE HEAVIER SHOWERS ASSOCIATED WITH THIS STREAK...THEN THE LOWER CIGS MAY LIFT BACK TO A LOWER MVFR RANGE...EVEN TO VFR ACROSS THE NIAGARA FRONTIER AT KBUF/KIAG. THE SURFACE LOW OVER THE WESTCENTRAL APPALACHIANS WILL FILL AND CONTINUE TO THE NORTH...BRINGING A PERIOD OF LOWER IFR CIGS AND MVFR VSBYS IN DRIZZLE OVERNIGHT. DRYING FROM ALOFT IN THE WEST WITH LINGERING MOISTURE OVER CENTRAL AND NORTHERN NY...IT SHOULD TAKE MOST OF THE DAY WEDNESDAY TO BRING CONDITIONS BACK TO VFR AT KART. OUTLOOK... WEDNESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS MAINLY CENTRAL AND NORTH. THURSDAY...VFR. FRIDAY...VFR/MVFR WITH SOME SHOWERS LIKELY. SATURDAY AND SUNDAY...VFR/MVFR CHANCE SHOWERS. && .MARINE... LOW PRESSURE WILL LIFT NORTH TOWARD THE OHIO VALLEY TODAY. LIGHT SOUTHERLY WINDS WITH PERIODS OF RAINS SHOWERS ARE EXPECTED TODAY THROUGH WEDNESDAY ACROSS THE LAKES. WAVES AVERAGING LESS THAN 2 FT. DRY WEATHER IS EXPECTED THURSDAY BEFORE A STRONG COLD FRONT CROSSES THE LOWER LAKES ON FRIDAY AND USHERS IN THE NEXT PERIOD OF STRONGER WINDS AND A RETURN TO COLDER WEATHER WHICH MAY BRING BACK SCA CONDITIONS. && .CLIMATE... THE MONTHLY CLIMATE SUMMARIES FOR SEPTEMBER HAVE BEEN ISSUED WITH A NARRATIVE DISCUSSION AT THE BOTTOM FOR BUF AND ROC. YOU CAN FIND THE FULL WRITE-UPS AND CLIMATE INFO IN BUFCLMBUF AND BUFCLMROC...OR ON OUR WEBSITE UNDER THE CLIMATE SECTION. IN BRIEF SUMMARY...THE HEAT THAT WAS SO COMMON THIS SUMMER LASTED INTO THE FIRST WEEK OF SEPTEMBER WITH TEMPERATURES RUNNING 5 TO 10 DEGREES ABOVE AVERAGE ON MOST DAYS. THE PATTERN FINALLY BROKE DURING THE SECOND WEEK OF THE MONTH...WITH MANY BELOW AVERAGE DAYS THEREAFTER. PRECIPITATION WAS A LITTLE ABOVE AVERAGE FOR THE MONTH THANKS TO SEVERAL SIGNIFICANT RAIN EVENTS...AND THIS WAS WELCOME RAIN THAT BEGAN TO PUT A DENT IN THE DROUGHT WHICH HAS BEEN PERSISTENT FOR MOST OF THE SPRING AND SUMMER. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...SMITH NEAR TERM...SMITH SHORT TERM...HITCHCOCK LONG TERM...HITCHCOCK AVIATION...WCH MARINE...SMITH CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
709 AM EDT TUE OCT 2 2012 .SYNOPSIS... LOW PRESSURE OVER THE TENNESSEE RIVER VALLEY WILL LIFT NORTH INTO THE OHIO RIVER VALLEY THROUGH TODAY. THIS SYSTEM WILL BRING WARM TEMPERATURES WITH INCREASING CLOUDS AND A FEW SHOWERS FROM THIS MORNING THROUGH WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AREA RADARS SHOWING SCATTERED RAIN SHOWERS LIFTING NORTHEAST ACROSS THE REGION THIS MORNING. THESE SHOWERS HAVE FORMED ALONG THE NOSE OF A 30-35KT 850MB LOW LEVEL JET AS DISPLAYED ON THE 10Z RAP MODEL AND MESOANALYSIS. BOTH 00Z AND 06Z MODELS RUNS ARE TOO SLOW WITH MOVING THIS FIRST SHOW OF RAIN ACROSS NEW YORK THIS MORNING. DESPITE THE SCATTERED NATURE OF PRECIP ALL PARTS OF WESTERN NY SHOULD PICK UP A FEW HUNDREDTHS UPWARDS TO A TENTH OF AN INCH THIS MORNING. EVEN LOCATIONS EAST OF LAKE ONTARIO COULD MEASURE BEFORE NOON. MILD TEMPERATURES AREAWIDE RUNNING IN THE MID 50S TO START TUESDAY AS WARM ADVECTION CONTINUES TO WORK NORTH AHEAD OF SURFACE LOW CENTERED OVER THE TENNESSEE VALLEY. THE STRENGTHENING WARM AIR ADVECTION PATTERN IN ADVANCE OF THIS LOW WILL SPREAD INCREASING AMOUNTS OF MOISTURE AND LIFT NORTHWARD TOWARD OUR REGION. LATER TODAY...THE SURFACE LOW WILL CONTINUE A SLOW NORTHWARD TREK INTO THE OHIO VALLEY. CLOUDS WILL CONTINUE TO LOWER WITH INCREASE IN MOISTURE AND CHANCES FOR SHOWERS SPREADING A BIT FURTHER NORTH AND EAST. THE BEST LIKELIHOOD OF PRECIP APPEARS TO BE ALONG A SURFACE TROUGH/WIND SHIFT/LOW LEVEL JET WHICH IS FORECAST TO SHIFT NORTHEAST ACROSS THE REGION THROUGH TODAY IN ADVANCE OF SURFACE WARM FRONT. THIS KEEPS HIGHEST CHANCES FOR SOUTHERN TIER INTO SOUTHERN FINGER LAKES INTO CENTRAL NY. OTHERWISE...EXPECT A CLOUDY DAY ALONG WITH WARMER TEMPS...WITH THE SOUTHERLY WARM AIR ADVECTION PATTERN HELPING TO BOOST TEMPS INTO THE UPPER 60S/LOWER 70S IN SPITE OF THE CLOUDY SKIES. TONIGHT THE SURFACE LOW WILL BE CENTERED OVER THE OHIO VALLEY WITH A WARM FRONT EXTENDING EASTWARD TO THE DELMARVA. STILL EXPECT SOME SHOWERS TO BE MOVING THROUGH THE EASTERN LAKE ONTARIO REGION WITH A BRIEF DRY BUT CLOUDY PERIOD ACROSS WESTERN NEW YORK. THROUGH THE NIGHT THE LOW WILL WEAKEN AND RETROGRADE TO THE WEST OVER INDIANA AS IT GETS CAUGHT BENEATH THE UPPER TROUGH. ACROSS NEW YORK THE SURFACE WARM FRONT WILL BE SHIFTING NORTH OVERNIGHT. THIS WILL BE AN ADDITIONAL FOCUS FOR A SECOND ROUND OF RAIN SHOWERS OVERNIGHT. KEPT CHANCE POPS WITH SOME UNCERTAINTY ON STRENGTH OF THE FRONT. ANOTHER NIGHT OF MILD TEMPS IS EXPECTED WITH LOWS WELL ABOVE NORMAL. MANY SPOTS WILL NOT SEE LOWS DROP BELOW 60 WITH OTHER SPOTS SEEING UPPER 50S FOR LOWS. SKIES WILL REMAIN CLOUDY AND WINDS LIGHT. QPF THROUGH THE NEAR TERM PERIOD WILL RANGE FROM AROUND A THIRD OF AN INCH ACROSS THE SOUTHERN TIER TAPERING TO AROUND A TENTH OF AN INCH FROM KIAG TO KART. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AT THE START OF THE PERIOD ON WEDNESDAY...A WEAK MID LEVEL CLOSED LOW WILL CONTINUE TO LIFT SLOWLY INTO THE LOWER OHIO VALLEY...WHILE A STRONG DOWNSTREAM RIDGE WILL TAKE UP RESIDENCE JUST OFF THE SOUTHEAST COAST IN A CLASSIC BERMUDA HIGH POSITION. THIS WILL RESULT IN CONTINUED DEEP SOUTHERLY FLOW INTO THE LOWER LAKES REGION WITH TEMPS AND HUMIDITY BECOMING MORE REMINISCENT OF SUMMER. THE MID LEVEL CIRCULATION AND ASSOCIATED VORTICITY MAXIMA WILL REMAIN WELL SOUTHWEST OF THE REGION...WITH LITTLE IN THE WAY OF SYNOPTIC SCALE ASCENT APPARENT BESIDES A WEAK WARM FRONT LIFTING ACROSS LAKE ONTARIO AND THE NORTH COUNTRY IN THE MORNING. WARM ADVECTION AND WEAK ISENTROPIC UPGLIDE MAY PRODUCE A FEW SCATTERED SHOWERS WEDNESDAY MORNING WITH THE BEST COVERAGE LIKELY TO BE NEAR LAKE ONTARIO AND THE NORTH COUNTRY IN CLOSER PROXIMITY TO THE RETREATING WARM FRONT. BY AFTERNOON EXPECT WESTERN NY TO DRY OUT AS THE WARM SECTOR BECOMES ESTABLISHED. THE NAM AND TO SOME EXTENT THE GFS DEVELOP SOME CONVECTION IN THE AFTERNOON FROM THE INTERIOR SOUTHERN TIER INTO THE FINGER LAKES ALONG A WEAK CONVERGENCE ZONE. MODEST SBCAPE OF 500-800 J/KG SHOULD BE ENOUGH TO SUPPORT WIDELY SCATTERED CONVECTION. WHAT DOES FORM WILL LIFT NORTHEAST INTO CENTRAL NY AND THE EASTERN LAKE ONTARIO REGION LATER IN THE DAY AND THROUGH WEDNESDAY EVENING BEFORE ENDING FROM WEST TO EAST. WEDNESDAY WILL BE QUITE WARM AS DEEP SOUTHERLY FLOW PUMPS 850MB TEMPS UP TO AROUND +14C. EVEN WITH SOME CLOUD COVER THIS WILL STILL SUPPORT UPPER 70S IN MOST AREAS...WITH A FEW LOWER 80S POSSIBLE IN THE WARMER SPOTS. SURFACE DEWPOINTS ARE ALSO FORECAST TO RISE INTO THE MID 60S GIVING A SUMMER-LIKE FEEL TO THE AIR. WEDNESDAY EVENING ANY CONVECTION ACROSS CENTRAL NY AND THE NORTH COUNTRY WILL END WITH THE LOSS OF DAYTIME HEATING. A NARROW SURFACE RIDGE WILL THEN BUILD INTO THE REGION OVERNIGHT WITH AT LEAST PARTLY CLEAR SKIES. THE VERY WARM AIRMASS WILL BRING A MILD NIGHT WITH LOWS RANGING FROM THE UPPER 50S TO LOWER 60S ON THE LAKE PLAINS AND EAST OF LAKE ONTARIO AND LOW TO MID 50S ACROSS THE INTERIOR SOUTHERN TIER. ON THURSDAY THE OHIO VALLEY CLOSED LOW WILL OPEN UP AND ACCELERATE NORTHEAST ACROSS THE GREAT LAKES IN RESPONSE TO AN UPSTREAM KICKER SHORTWAVE. THE MID LEVEL TROUGH WILL QUICKLY DEAMPLIFY WITH TIME AND THE SURFACE TROUGH WILL LOSE DEFINITION. THE WEAKENING FORCING FOR ASCENT AND VERY LIMITED MOISTURE SHOULD ALLOW THE MID LEVEL TROUGH TO PASS WITH LITTLE FANFARE...WITH JUST A PERIOD OF MID LEVEL CLOUD COVER. ANY SHOWERS SHOULD REMAIN WELL NORTH ACROSS ONTARIO PROVINCE WHERE STRONGER ASCENT AND DEEPER MOISTURE WILL BE FOUND. IT WILL BE ANOTHER WARM DAY AHEAD OF THE TROUGH PASSAGE WITH HIGHS WELL INTO THE 70S IN MOST AREAS...AND POSSIBLY PUSHING 80 AGAIN ACROSS CENTRAL NY. THURSDAY NIGHT ANOTHER NARROW RIDGE BUILDS INTO THE LOWER LAKES WITH CLEARING SKIES. AGAIN THE AIRMASS WILL REMAIN QUITE MILD FOR THIS TIME OF YEAR...AND WINDS WILL NOT DECOUPLE WHICH WILL KEEP LOWS IN THE MID TO UPPER 50S IN MOST AREAS. CLOUDS WILL INCREASE FROM WEST TO EAST LATE AHEAD OF THE NEXT SYSTEM...BUT ANY RAIN SHOULD HOLD OFF UNTIL AROUND DAYBREAK FRIDAY. && .LONG TERM /FRIDAY THROUGH MONDAY/... THE LONGWAVE PATTERN WILL BECOME STRONGLY AMPLIFIED THROUGH THE LONG TERM PERIOD WITH A DEEP FULL LATITUDE TROUGH BECOMING ESTABLISHED FROM CENTRAL CANADA AND THE CENTRAL US TO THE APPALACHIANS... EVENTUALLY SPREADING TO THE EAST COAST BY DAY 6-7. UPSTREAM A STRONG RIDGE WILL DEVELOP INITIALLY OVER THE GULF OF ALASKA THEN PUSH EAST TO THE BRITISH COLUMBIA COAST BY DAY 7. THIS PATTERN AMPLIFICATION WILL SUPPORT A TURN TOWARDS MUCH BELOW NORMAL TEMPERATURES FOR THE GREAT LAKES THIS WEEKEND INTO EARLY NEXT WEEK. LOOKING AT THE DETAILS...ON FRIDAY AN INITIAL MID LEVEL LOW WILL SWING ACROSS NORTHWEST ONTARIO PROVINCE AND REACH JAMES BAY BY LATE IN THE DAY. AN ASSOCIATED STRONG SURFACE COLD FRONT WILL CROSS THE LOWER LAKES WITH A BRIEF PERIOD OF SHOWERS. THE LATEST 00Z MODEL GUIDANCE IS A LITTLE FASTER WITH THE FROPA...SO SHOWERS MAY COME DURING THE FIRST HALF OF THE DAY WITH FALLING TEMPS IN THE AFTERNOON. LATER FRIDAY NIGHT INTO THE WEEKEND VERY CHILLY AIR WILL BECOME ESTABLISHED FROM THE NORTHERN PLAINS INTO THE GREAT LAKES AND NEW ENGLAND. MODEL GUIDANCE CONTINUES TO STRUGGLE WITH THE HANDLING OF A POTENTIAL FRONTAL WAVE. LATEST 00Z GFS SHOWS A RATHER ROBUST FRONTAL WAVE RUNNING THROUGH THE LOWER LAKES LATE FRIDAY NIGHT INTO SATURDAY...WHICH WOULD BRING A WIDESPREAD CHILLY RAIN. THE 00Z ECMWF ALSO HAS A FRONTAL WAVE...JUST A LITTLE WEAKER AND ABOUT 6 HOURS SLOWER. IT ALSO TRIES TO DEVELOP A SECOND FRONTAL WAVE ON SUNDAY AS IT PHASES WITH ADDITIONAL NORTHERN STREAM ENERGY DIGGING INTO THE UPPER GREAT LAKES. GIVEN THE COMPLEXITY OF THE SCENARIO...IT WILL LIKELY BE SEVERAL DAYS BEFORE THE MODEL GUIDANCE SETTLES DOWN AND CONVERGES ON A COMMON SOLUTION. FOR NOW WILL SIMPLY USE CHANCE POPS BOTH DAYS. WHAT IS MUCH HIGHER CONFIDENCE IS THE BELOW NORMAL TEMPERATURES BEGINNING THIS WEEKEND...WITH HIGHS ONLY IN THE LOWER 50S BOTH DAYS ACROSS LOWER ELEVATIONS AND MID TO UPPER 40S ACROSS HIGHER TERRAIN. EVEN THIS MAY BE TOO WARM IF WIDESPREAD CLOUD COVER AND RAIN IS REALIZED. THE CLOUD COVER WILL KEEP OVERNIGHT LOWS ABOVE FREEZING FRIDAY NIGHT AND PROBABLY SATURDAY NIGHT AS WELL. THE COLDEST NIGHT WILL LIKELY BE SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE OHIO VALLEY AND LOWER LAKES WITH CLEARING SKIES AND LIGHTER WINDS. IF THE HIGH DOES INDEED SETTLE OVERHEAD...WIDESPREAD FROST/FREEZE CONDITIONS MAY BE ON THE WAY. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS THIS MORNING OUTSIDE OF RAIN SHOWERS. SOME LOWER CIGS OBSERVED IN SCATTERED SHOWER ACTIVITY. LOW PRESSURE OVER THE TENNESSEE VALLEY LIFTING NORTHWARD INTO THE OHIO VALLEY THROUGH TODAY. AHEAD OF THIS LOW SOME LIGHT SHOWERS WILL CONTINUE TO SHIFT NORTH AND EAST THOUGH THE MORNING. OTHERWISE...INCREASING AMOUNTS OF MOISTURE SPREADING NORTH IN ADVANCE OF THE LOW WILL RESULT IN LOWERING VFR CLOUDS THIS MORNING. OVERNIGHT TONIGHT...SOMEWHAT BETTER CHANCES FOR SHOWERS ARE POSSIBLE AS A WARM FRONT LIFTS ACROSS THE STATE. ALONG WITH THIS GUIDANCE IS SHOWING POTENTIALLY SOME IFR CIGS BY LATE THIS EVENING. HAVE GONE WITH LOW END MVFR FOR NOW AND WILL CONTINUE TO MONITOR AND ADJUST TAFS AS CONFIDENCE INCREASES. ALSO SOME LLWS POSSIBLE AT KJHW AS BUFKIT PROFILES SHOW 30-35KT LLJ SHIFTING OVERHEAD THIS MORNING. THIS JET IS RESPONSIBLE FOR TRIGGERING THE CURRENT SHOWERS. OUTLOOK... WEDNESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS. SOME ISOLATED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON. THURSDAY...MAINLY VFR. FRIDAY...VFR/MVFR WITH SOME SHOWERS LIKELY. SATURDAY...VFR/MVFR CHANCE SHOWERS. && .MARINE... LOW PRESSURE WILL LIFT NORTH TOWARD THE OHIO VALLEY TODAY. LIGHT SOUTHERLY WINDS WITH PERIODS OF RAINS SHOWERS ARE EXPECTED TODAY THROUGH WEDNESDAY ACROSS THE LAKES. WAVES AVERAGING LESS THAN 2 FT. DRY WEATHER IS EXPECTED THURSDAY BEFORE A STRONG COLD FRONT CROSSES THE LOWER LAKES ON FRIDAY AND USHERS IN THE NEXT PERIOD OF STRONGER WINDS AND A RETURN TO COLDER WEATHER WHICH MAY BRING BACK SCA CONDITIONS. && .CLIMATE... THE MONTHLY CLIMATE SUMMARIES FOR SEPTEMBER HAVE BEEN ISSUED WITH A NARRATIVE DISCUSSION AT THE BOTTOM FOR BUF AND ROC. YOU CAN FIND THE FULL WRITE-UPS AND CLIMATE INFO IN BUFCLMBUF AND BUFCLMROC...OR ON OUR WEBSITE UNDER THE CLIMATE SECTION. IN BRIEF SUMMARY...THE HEAT THAT WAS SO COMMON THIS SUMMER LASTED INTO THE FIRST WEEK OF SEPTEMBER WITH TEMPERATURES RUNNING 5 TO 10 DEGREES ABOVE AVERAGE ON MOST DAYS. THE PATTERN FINALLY BROKE DURING THE SECOND WEEK OF THE MONTH...WITH MANY BELOW AVERAGE DAYS THEREAFTER. PRECIPITATION WAS A LITTLE ABOVE AVERAGE FOR THE MONTH THANKS TO SEVERAL SIGNIFICANT RAIN EVENTS...AND THIS WAS WELCOME RAIN THAT BEGAN TO PUT A DENT IN THE DROUGHT WHICH HAS BEEN PERSISTENT FOR MOST OF THE SPRING AND SUMMER. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...SMITH NEAR TERM...SMITH SHORT TERM...HITCHCOCK LONG TERM...HITCHCOCK AVIATION...SMITH MARINE...SMITH CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
555 AM EDT TUE OCT 2 2012 .SYNOPSIS... LOW PRESSURE OVER THE TENNESSEE RIVER VALLEY WILL LIFT NORTH INTO THE OHIO RIVER VALLEY THROUGH TODAY. THIS SYSTEM WILL BRING WARM TEMPERATURES WITH INCREASING CLOUDS AND A FEW SHOWERS FROM THIS MORNING THROUGH WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... KBUF RADAR SHOWING SCATTERED RAIN SHOWERS LIFTING NORTHEAST ACROSS NORTHWESTERN PA AND FAR WESTERN NY AS OF 4AM. THESE SHOWERS HAVE FORMED ALONG THE NOSE OF A 40-45KT 850MB LOW LEVEL JET AS DISPLAYED ON THE LATEST RAP MODEL AND MESOANALYSIS. ALL 00Z MODELS ARE AT LEAST 3 HOURS TOO SLOW WITH PROGRESSION OF CURRENT RADAR TRENDS. CURRENT FORECAST GRIDS ARE A HAND EDIT TRENDING TOWARD GUIDANCE LATER THIS MORNING. FEEL THAT DESPITE THE SCATTERED NATURE OF PRECIP THAT ALL AREAS SHOULD PICK UP A FEW HUNDREDTHS UPWARDS TO A TENTH OF AN INCH. LOWEST CONFIDENCE IN FORECAST IS ACROSS NIAGARA COUNTY AND SOUTHERN SHORE OF LAKE ONTARIO WHERE MOST GUIDANCE KEEPS THOSE AREAS DRY BUT RADAR EXTRAPOLATION WOULD PROVE OTHERWISE. MILD TEMPERATURES AREA WIDE RUNNING IN THE 50S AS WARM ADVECTION CONTINUES TO WORK NORTH AHEAD OF SURFACE LOW CENTERED OVER THE TENNESSEE VALLEY. THE STRENGTHENING WARM AIR ADVECTION PATTERN IN ADVANCE OF THIS LOW WILL SPREAD INCREASING AMOUNTS OF MOISTURE AND LIFT NORTHWARD TOWARD OUR REGION. LATER TODAY...THE SURFACE LOW WILL CONTINUE A SLOW NORTHWARD TREK INTO THE OHIO VALLEY. CLOUDS WILL CONTINUE TO LOWER WITH INCREASE IN MOISTURE AND CHANCES FOR SHOWERS SPREADING A BIT FURTHER NORTH AND EAST. THE BEST LIKELIHOOD OF PRECIP APPEARS TO BE ALONG A SURFACE TROUGH/WIND SHIFT/LOW LEVEL JET WHICH IS FORECAST TO SHIFT NORTHEAST ACROSS THE REGION THROUGH TODAY IN ADVANCE OF SURFACE WARM FRONT. THIS KEEPS HIGHEST CHANCES FOR SOUTHERN TIER INTO SOUTHERN FINGER LAKES INTO CENTRAL NY. OTHERWISE...EXPECT A CLOUDY DAY ALONG WITH WARMER TEMPS...WITH THE SOUTHERLY WARM AIR ADVECTION PATTERN HELPING TO BOOST TEMPS INTO THE UPPER 60S/LOWER 70S IN SPITE OF THE CLOUDY SKIES. TONIGHT THE SURFACE LOW WILL BE CENTERED OVER THE OHIO VALLEY WITH A WARM FRONT EXTENDING EASTWARD TO THE DELMARVA. STILL EXPECT SOME SHOWERS TO BE MOVING THROUGH THE EASTERN LAKE ONTARIO REGION WITH A BRIEF DRY BUT CLOUDY PERIOD ACROSS WESTERN NEW YORK. THROUGH THE NIGHT THE LOW WILL WEAKEN AND RETROGRADE TO THE WEST OVER INDIANA AS IT GETS CAUGHT BENEATH THE UPPER TROUGH. ACROSS NEW YORK THE SURFACE WARM FRONT WILL BE SHIFTING NORTH OVERNIGHT. THIS WILL BE AN ADDITIONAL FOCUS FOR ANOTHER ROUND OF RAIN SHOWERS OVERNIGHT. KEPT CHANCE POPS WITH SOME UNCERTAINTY ON STRENGTH OF THE FRONT. ANOTHER NIGHT OF MILD TEMPS IS EXPECTED WITH LOWS WELL ABOVE NORMAL. MANY SPOTS WILL NOT SEE LOWS DROP BELOW 60 WITH OTHER SPOTS SEEING UPPER 50S FOR LOWS. SKIES WILL REMAIN CLOUDY AND WINDS LIGHT. QPF THROUGH THE NEAR TERM PERIOD WILL RANGE FROM AROUND A THIRD OF AN INCH ACROSS THE SOUTHERN TIER TAPERING TO AROUND A TENTH OF AN INCH FROM KIAG TO KART. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AT THE START OF THE PERIOD ON WEDNESDAY...A WEAK MID LEVEL CLOSED LOW WILL CONTINUE TO LIFT SLOWLY INTO THE LOWER OHIO VALLEY...WHILE A STRONG DOWNSTREAM RIDGE WILL TAKE UP RESIDENCE JUST OFF THE SOUTHEAST COAST IN A CLASSIC BERMUDA HIGH POSITION. THIS WILL RESULT IN CONTINUED DEEP SOUTHERLY FLOW INTO THE LOWER LAKES REGION WITH TEMPS AND HUMIDITY BECOMING MORE REMINISCENT OF SUMMER. THE MID LEVEL CIRCULATION AND ASSOCIATED VORTICITY MAXIMA WILL REMAIN WELL SOUTHWEST OF THE REGION...WITH LITTLE IN THE WAY OF SYNOPTIC SCALE ASCENT APPARENT BESIDES A WEAK WARM FRONT LIFTING ACROSS LAKE ONTARIO AND THE NORTH COUNTRY IN THE MORNING. WARM ADVECTION AND WEAK ISENTROPIC UPGLIDE MAY PRODUCE A FEW SCATTERED SHOWERS WEDNESDAY MORNING WITH THE BEST COVERAGE LIKELY TO BE NEAR LAKE ONTARIO AND THE NORTH COUNTRY IN CLOSER PROXIMITY TO THE RETREATING WARM FRONT. BY AFTERNOON EXPECT WESTERN NY TO DRY OUT AS THE WARM SECTOR BECOMES ESTABLISHED. THE NAM AND TO SOME EXTENT THE GFS DEVELOP SOME CONVECTION IN THE AFTERNOON FROM THE INTERIOR SOUTHERN TIER INTO THE FINGER LAKES ALONG A WEAK CONVERGENCE ZONE. MODEST SBCAPE OF 500-800 J/KG SHOULD BE ENOUGH TO SUPPORT WIDELY SCATTERED CONVECTION. WHAT DOES FORM WILL LIFT NORTHEAST INTO CENTRAL NY AND THE EASTERN LAKE ONTARIO REGION LATER IN THE DAY AND THROUGH WEDNESDAY EVENING BEFORE ENDING FROM WEST TO EAST. WEDNESDAY WILL BE QUITE WARM AS DEEP SOUTHERLY FLOW PUMPS 850MB TEMPS UP TO AROUND +14C. EVEN WITH SOME CLOUD COVER THIS WILL STILL SUPPORT UPPER 70S IN MOST AREAS...WITH A FEW LOWER 80S POSSIBLE IN THE WARMER SPOTS. SURFACE DEWPOINTS ARE ALSO FORECAST TO RISE INTO THE MID 60S GIVING A SUMMER-LIKE FEEL TO THE AIR. WEDNESDAY EVENING ANY CONVECTION ACROSS CENTRAL NY AND THE NORTH COUNTRY WILL END WITH THE LOSS OF DAYTIME HEATING. A NARROW SURFACE RIDGE WILL THEN BUILD INTO THE REGION OVERNIGHT WITH AT LEAST PARTLY CLEAR SKIES. THE VERY WARM AIRMASS WILL BRING A MILD NIGHT WITH LOWS RANGING FROM THE UPPER 50S TO LOWER 60S ON THE LAKE PLAINS AND EAST OF LAKE ONTARIO AND LOW TO MID 50S ACROSS THE INTERIOR SOUTHERN TIER. ON THURSDAY THE OHIO VALLEY CLOSED LOW WILL OPEN UP AND ACCELERATE NORTHEAST ACROSS THE GREAT LAKES IN RESPONSE TO AN UPSTREAM KICKER SHORTWAVE. THE MID LEVEL TROUGH WILL QUICKLY DEAMPLIFY WITH TIME AND THE SURFACE TROUGH WILL LOSE DEFINITION. THE WEAKENING FORCING FOR ASCENT AND VERY LIMITED MOISTURE SHOULD ALLOW THE MID LEVEL TROUGH TO PASS WITH LITTLE FANFARE...WITH JUST A PERIOD OF MID LEVEL CLOUD COVER. ANY SHOWERS SHOULD REMAIN WELL NORTH ACROSS ONTARIO PROVINCE WHERE STRONGER ASCENT AND DEEPER MOISTURE WILL BE FOUND. IT WILL BE ANOTHER WARM DAY AHEAD OF THE TROUGH PASSAGE WITH HIGHS WELL INTO THE 70S IN MOST AREAS...AND POSSIBLY PUSHING 80 AGAIN ACROSS CENTRAL NY. THURSDAY NIGHT ANOTHER NARROW RIDGE BUILDS INTO THE LOWER LAKES WITH CLEARING SKIES. AGAIN THE AIRMASS WILL REMAIN QUITE MILD FOR THIS TIME OF YEAR...AND WINDS WILL NOT DECOUPLE WHICH WILL KEEP LOWS IN THE MID TO UPPER 50S IN MOST AREAS. CLOUDS WILL INCREASE FROM WEST TO EAST LATE AHEAD OF THE NEXT SYSTEM...BUT ANY RAIN SHOULD HOLD OFF UNTIL AROUND DAYBREAK FRIDAY. && .LONG TERM /FRIDAY THROUGH MONDAY/... THE LONGWAVE PATTERN WILL BECOME STRONGLY AMPLIFIED THROUGH THE LONG TERM PERIOD WITH A DEEP FULL LATITUDE TROUGH BECOMING ESTABLISHED FROM CENTRAL CANADA AND THE CENTRAL US TO THE APPALACHIANS... EVENTUALLY SPREADING TO THE EAST COAST BY DAY 6-7. UPSTREAM A STRONG RIDGE WILL DEVELOP INITIALLY OVER THE GULF OF ALASKA THEN PUSH EAST TO THE BRITISH COLUMBIA COAST BY DAY 7. THIS PATTERN AMPLIFICATION WILL SUPPORT A TURN TOWARDS MUCH BELOW NORMAL TEMPERATURES FOR THE GREAT LAKES THIS WEEKEND INTO EARLY NEXT WEEK. LOOKING AT THE DETAILS...ON FRIDAY AN INITIAL MID LEVEL LOW WILL SWING ACROSS NORTHWEST ONTARIO PROVINCE AND REACH JAMES BAY BY LATE IN THE DAY. AN ASSOCIATED STRONG SURFACE COLD FRONT WILL CROSS THE LOWER LAKES WITH A BRIEF PERIOD OF SHOWERS. THE LATEST 00Z MODEL GUIDANCE IS A LITTLE FASTER WITH THE FROPA...SO SHOWERS MAY COME DURING THE FIRST HALF OF THE DAY WITH FALLING TEMPS IN THE AFTERNOON. LATER FRIDAY NIGHT INTO THE WEEKEND VERY CHILLY AIR WILL BECOME ESTABLISHED FROM THE NORTHERN PLAINS INTO THE GREAT LAKES AND NEW ENGLAND. MODEL GUIDANCE CONTINUES TO STRUGGLE WITH THE HANDLING OF A POTENTIAL FRONTAL WAVE. LATEST 00Z GFS SHOWS A RATHER ROBUST FRONTAL WAVE RUNNING THROUGH THE LOWER LAKES LATE FRIDAY NIGHT INTO SATURDAY...WHICH WOULD BRING A WIDESPREAD CHILLY RAIN. THE 00Z ECMWF ALSO HAS A FRONTAL WAVE...JUST A LITTLE WEAKER AND ABOUT 6 HOURS SLOWER. IT ALSO TRIES TO DEVELOP A SECOND FRONTAL WAVE ON SUNDAY AS IT PHASES WITH ADDITIONAL NORTHERN STREAM ENERGY DIGGING INTO THE UPPER GREAT LAKES. GIVEN THE COMPLEXITY OF THE SCENARIO...IT WILL LIKELY BE SEVERAL DAYS BEFORE THE MODEL GUIDANCE SETTLES DOWN AND CONVERGES ON A COMMON SOLUTION. FOR NOW WILL SIMPLY USE CHANCE POPS BOTH DAYS. WHAT IS MUCH HIGHER CONFIDENCE IS THE BELOW NORMAL TEMPERATURES BEGINNING THIS WEEKEND...WITH HIGHS ONLY IN THE LOWER 50S BOTH DAYS ACROSS LOWER ELEVATIONS AND MID TO UPPER 40S ACROSS HIGHER TERRAIN. EVEN THIS MAY BE TOO WARM IF WIDESPREAD CLOUD COVER AND RAIN IS REALIZED. THE CLOUD COVER WILL KEEP OVERNIGHT LOWS ABOVE FREEZING FRIDAY NIGHT AND PROBABLY SATURDAY NIGHT AS WELL. THE COLDEST NIGHT WILL LIKELY BE SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE OHIO VALLEY AND LOWER LAKES WITH CLEARING SKIES AND LIGHTER WINDS. IF THE HIGH DOES INDEED SETTLE OVERHEAD...WIDESPREAD FROST/FREEZE CONDITIONS MAY BE ON THE WAY. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... LOW PRESSURE OVER THE TENNESSEE VALLEY WILL LIFT NORTHWARD INTO THE OHIO VALLEY THROUGH TODAY. AHEAD OF THIS LOW SOME LIGHT SHOWERS ARE SHIFTING ACROSS WESTERN NY AND WILL CONTINUE TO SHIFT NORTH AND EAST THOUGH THE MORNING. LIGHT RA IS BEING REPORTED AT KBUF AND KIAG AT 08Z AND WILL LIKELY REACH KROC BY 09/10Z. OTHERWISE...INCREASING AMOUNTS OF MOISTURE SPREADING NORTH IN ADVANCE OF THE LOW WILL RESULT IN LOWERING VFR CLOUDS THIS MORNING. OVERNIGHT TONIGHT...SOMEWHAT BETTER CHANCES FOR SHOWERS ARE POSSIBLE AS A WARM FRONT LIFTS ACROSS THE STATE. ALONG WITH THIS GUIDANCE IS SHOWING POTENTIALLY SOME IFR CIGS BY LATE THIS EVENING. WILL CONTINUE TO MONITOR AND ADD TO TAFS AS CONFIDENCE INCREASES. OUTLOOK... WEDNESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS. SOME ISOLATED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON. THURSDAY...MAINLY VFR. FRIDAY...VFR/MVFR WITH SOME SHOWERS LIKELY. SATURDAY...VFR/MVFR CHANCE SHOWERS. && .MARINE... LOW PRESSURE WILL LIFT NORTH TOWARD THE OHIO VALLEY TODAY. LIGHT SOUTHERLY WINDS WITH PERIODS OF RAINS SHOWERS ARE EXPECTED TODAY THROUGH WEDNESDAY ACROSS THE LAKES. DRY WEATHER IS EXPECTED THURSDAY BEFORE A STRONG COLD FRONT CROSSES THE LOWER LAKES ON FRIDAY AND USHERS IN THE NEXT PERIOD OF STRONGER WINDS AND A RETURN TO COLDER WEATHER WHICH MAY BRING BACK SCA CONDITIONS. && .CLIMATE... THE MONTHLY CLIMATE SUMMARIES FOR SEPTEMBER HAVE BEEN ISSUED WITH A NARRATIVE DISCUSSION AT THE BOTTOM FOR BUF AND ROC. YOU CAN FIND THE FULL WRITE-UPS AND CLIMATE INFO IN BUFCLMBUF AND BUFCLMROC...OR ON OUR WEBSITE UNDER THE CLIMATE SECTION. IN BRIEF SUMMARY...THE HEAT THAT WAS SO COMMON THIS SUMMER LASTED INTO THE FIRST WEEK OF SEPTEMBER WITH TEMPERATURES RUNNING 5 TO 10 DEGREES ABOVE AVERAGE ON MOST DAYS. THE PATTERN FINALLY BROKE DURING THE SECOND WEEK OF THE MONTH...WITH MANY BELOW AVERAGE DAYS THEREAFTER. PRECIPITATION WAS A LITTLE ABOVE AVERAGE FOR THE MONTH THANKS TO SEVERAL SIGNIFICANT RAIN EVENTS...AND THIS WAS WELCOME RAIN THAT BEGAN TO PUT A DENT IN THE DROUGHT WHICH HAS BEEN PERSISTENT FOR MOST OF THE SPRING AND SUMMER. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...SMITH NEAR TERM...SMITH SHORT TERM...HITCHCOCK LONG TERM...HITCHCOCK AVIATION...SMITH MARINE...SMITH CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
415 AM EDT TUE OCT 2 2012 .SYNOPSIS... LOW PRESSURE OVER THE TENNESSEE RIVER VALLEY WILL LIFT NORTH INTO THE OHIO RIVER VALLEY THROUGH TODAY. THIS SYSTEM WILL BRING WARM TEMPERATURES WITH INCREASING CLOUDS AND A FEW SHOWERS FROM THIS MORNING THROUGH WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... KBUF RADAR SHOWING SCATTERED RAIN SHOWERS LIFTING NORTHEAST ACROSS NORTHWESTERN PA AND FAR WESTERN NY AS OF 4AM. THESE SHOWERS HAVE FORMED ALONG THE NOSE OF A 40-45KT 850MB LOW LEVEL JET AS DISPLAYED ON THE LATEST RAP MODEL AND MESOANALYSIS. ALL 00Z MODELS ARE AT LEAST 3 HOURS TOO SLOW WITH PROGRESSION OF CURRENT RADAR TRENDS. CURRENT FORECAST GRIDS ARE A HAND EDIT TRENDING TOWARD GUIDANCE LATER THIS MORNING. FEEL THAT DESPITE THE SCATTERED NATURE OF PRECIP THAT ALL AREAS SHOULD PICK UP A FEW HUNDREDTHS UPWARDS TO A TENTH OF AN INCH. LOWEST CONFIDENCE IN FORECAST IS ACROSS NIAGARA COUNTY AND SOUTHERN SHORE OF LAKE ONTARIO WHERE MOST GUIDANCE KEEPS THOSE AREAS DRY BUT RADAR EXTRAPOLATION WOULD PROVE OTHERWISE. MILD TEMPERATURES AREA WIDE RUNNING IN THE 50S AS WARM ADVECTION CONTINUES TO WORK NORTH AHEAD OF SURFACE LOW CENTERED OVER THE TENNESSEE VALLEY. THE STRENGTHENING WARM AIR ADVECTION PATTERN IN ADVANCE OF THIS LOW WILL SPREAD INCREASING AMOUNTS OF MOISTURE AND LIFT NORTHWARD TOWARD OUR REGION. LATER TODAY...THE SURFACE LOW WILL CONTINUE A SLOW NORTHWARD TREK INTO THE OHIO VALLEY. CLOUDS WILL CONTINUE TO LOWER WITH INCREASE IN MOISTURE AND CHANCES FOR SHOWERS SPREADING A BIT FURTHER NORTH AND EAST. THE BEST LIKELIHOOD OF PRECIP APPEARS TO BE ALONG A SURFACE TROUGH/WIND SHIFT/LOW LEVEL JET WHICH IS FORECAST TO SHIFT NORTHEAST ACROSS THE REGION THROUGH TODAY IN ADVANCE OF SURFACE WARM FRONT. THIS KEEPS HIGHEST CHANCES FOR SOUTHERN TIER INTO SOUTHERN FINGER LAKES INTO CENTRAL NY. OTHERWISE...EXPECT A CLOUDY DAY ALONG WITH WARMER TEMPS...WITH THE SOUTHERLY WARM AIR ADVECTION PATTERN HELPING TO BOOST TEMPS INTO THE UPPER 60S/LOWER 70S IN SPITE OF THE CLOUDY SKIES. TONIGHT THE SURFACE LOW WILL BE CENTERED OVER THE OHIO VALLEY WITH A WARM FRONT EXTENDING EASTWARD TO THE DELMARVA. STILL EXPECT SOME SHOWERS TO BE MOVING THROUGH THE EASTERN LAKE ONTARIO REGION WITH A BRIEF DRY BUT CLOUDY PERIOD ACROSS WESTERN NEW YORK. THROUGH THE NIGHT THE LOW WILL WEAKEN AND RETROGRADE TO THE WEST OVER INDIANA AS IT GETS CAUGHT BENEATH THE UPPER TROUGH. ACROSS NEW YORK THE SURFACE WARM FRONT WILL BE SHIFTING NORTH OVERNIGHT. THIS WILL BE AN ADDITIONAL FOCUS FOR ANOTHER ROUND OF RAIN SHOWERS OVERNIGHT. KEPT CHANCE POPS WITH SOME UNCERTAINTY ON STRENGTH OF THE FRONT. ANOTHER NIGHT OF MILD TEMPS IS EXPECTED WITH LOWS WELL ABOVE NORMAL. MANY SPOTS WILL NOT SEE LOWS DROP BELOW 60 WITH OTHER SPOTS SEEING UPPER 50S FOR LOWS. SKIES WILL REMAIN CLOUDY AND WINDS LIGHT. QPF THROUGH THE NEAR TERM PERIOD WILL RANGE FROM AROUND A THIRD OF AN INCH ACROSS THE SOUTHERN TIER TAPERING TO AROUND A TENTH OF AN INCH FROM KIAG TO KART. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AT THE START OF THE PERIOD ON WEDNESDAY...A WEAK MID LEVEL CLOSED LOW WILL CONTINUE TO LIFT SLOWLY INTO THE LOWER OHIO VALLEY...WHILE A STRONG DOWNSTREAM RIDGE WILL TAKE UP RESIDENCE JUST OFF THE SOUTHEAST COAST IN A CLASSIC BERMUDA HIGH POSITION. THIS WILL RESULT IN CONTINUED DEEP SOUTHERLY FLOW INTO THE LOWER LAKES REGION WITH TEMPS AND HUMIDITY BECOMING MORE REMINISCENT OF SUMMER. THE MID LEVEL CIRCULATION AND ASSOCIATED VORTICITY MAXIMA WILL REMAIN WELL SOUTHWEST OF THE REGION...WITH LITTLE IN THE WAY OF SYNOPTIC SCALE ASCENT APPARENT BESIDES A WEAK WARM FRONT LIFTING ACROSS LAKE ONTARIO AND THE NORTH COUNTRY IN THE MORNING. WARM ADVECTION AND WEAK ISENTROPIC UPGLIDE MAY PRODUCE A FEW SCATTERED SHOWERS WEDNESDAY MORNING WITH THE BEST COVERAGE LIKELY TO BE NEAR LAKE ONTARIO AND THE NORTH COUNTRY IN CLOSER PROXIMITY TO THE RETREATING WARM FRONT. BY AFTERNOON EXPECT WESTERN NY TO DRY OUT AS THE WARM SECTOR BECOMES ESTABLISHED. THE NAM AND TO SOME EXTENT THE GFS DEVELOP SOME CONVECTION IN THE AFTERNOON FROM THE INTERIOR SOUTHERN TIER INTO THE FINGER LAKES ALONG A WEAK CONVERGENCE ZONE. MODEST SBCAPE OF 500-800 J/KG SHOULD BE ENOUGH TO SUPPORT WIDELY SCATTERED CONVECTION. WHAT DOES FORM WILL LIFT NORTHEAST INTO CENTRAL NY AND THE EASTERN LAKE ONTARIO REGION LATER IN THE DAY AND THROUGH WEDNESDAY EVENING BEFORE ENDING FROM WEST TO EAST. WEDNESDAY WILL BE QUITE WARM AS DEEP SOUTHERLY FLOW PUMPS 850MB TEMPS UP TO AROUND +14C. EVEN WITH SOME CLOUD COVER THIS WILL STILL SUPPORT UPPER 70S IN MOST AREAS...WITH A FEW LOWER 80S POSSIBLE IN THE WARMER SPOTS. SURFACE DEWPOINTS ARE ALSO FORECAST TO RISE INTO THE MID 60S GIVING A SUMMER-LIKE FEEL TO THE AIR. WEDNESDAY EVENING ANY CONVECTION ACROSS CENTRAL NY AND THE NORTH COUNTRY WILL END WITH THE LOSS OF DAYTIME HEATING. A NARROW SURFACE RIDGE WILL THEN BUILD INTO THE REGION OVERNIGHT WITH AT LEAST PARTLY CLEAR SKIES. THE VERY WARM AIRMASS WILL BRING A MILD NIGHT WITH LOWS RANGING FROM THE UPPER 50S TO LOWER 60S ON THE LAKE PLAINS AND EAST OF LAKE ONTARIO AND LOW TO MID 50S ACROSS THE INTERIOR SOUTHERN TIER. ON THURSDAY THE OHIO VALLEY CLOSED LOW WILL OPEN UP AND ACCELERATE NORTHEAST ACROSS THE GREAT LAKES IN RESPONSE TO AN UPSTREAM KICKER SHORTWAVE. THE MID LEVEL TROUGH WILL QUICKLY DEAMPLIFY WITH TIME AND THE SURFACE TROUGH WILL LOSE DEFINITION. THE WEAKENING FORCING FOR ASCENT AND VERY LIMITED MOISTURE SHOULD ALLOW THE MID LEVEL TROUGH TO PASS WITH LITTLE FANFARE...WITH JUST A PERIOD OF MID LEVEL CLOUD COVER. ANY SHOWERS SHOULD REMAIN WELL NORTH ACROSS ONTARIO PROVINCE WHERE STRONGER ASCENT AND DEEPER MOISTURE WILL BE FOUND. IT WILL BE ANOTHER WARM DAY AHEAD OF THE TROUGH PASSAGE WITH HIGHS WELL INTO THE 70S IN MOST AREAS...AND POSSIBLY PUSHING 80 AGAIN ACROSS CENTRAL NY. THURSDAY NIGHT ANOTHER NARROW RIDGE BUILDS INTO THE LOWER LAKES WITH CLEARING SKIES. AGAIN THE AIRMASS WILL REMAIN QUITE MILD FOR THIS TIME OF YEAR...AND WINDS WILL NOT DECOUPLE WHICH WILL KEEP LOWS IN THE MID TO UPPER 50S IN MOST AREAS. CLOUDS WILL INCREASE FROM WEST TO EAST LATE AHEAD OF THE NEXT SYSTEM...BUT ANY RAIN SHOULD HOLD OFF UNTIL AROUND DAYBREAK FRIDAY. && .LONG TERM /FRIDAY THROUGH MONDAY/... THE LONGWAVE PATTERN WILL BECOME STRONGLY AMPLIFIED THROUGH THE LONG TERM PERIOD WITH A DEEP FULL LATITUDE TROUGH BECOMING ESTABLISHED FROM CENTRAL CANADA AND THE CENTRAL US TO THE APPALACHIANS... EVENTUALLY SPREADING TO THE EAST COAST BY DAY 6-7. UPSTREAM A STRONG RIDGE WILL DEVELOP INITIALLY OVER THE GULF OF ALASKA THEN PUSH EAST TO THE BRITISH COLUMBIA COAST BY DAY 7. THIS PATTERN AMPLIFICATION WILL SUPPORT A TURN TOWARDS MUCH BELOW NORMAL TEMPERATURES FOR THE GREAT LAKES THIS WEEKEND INTO EARLY NEXT WEEK. LOOKING AT THE DETAILS...ON FRIDAY AN INITIAL MID LEVEL LOW WILL SWING ACROSS NORTHWEST ONTARIO PROVINCE AND REACH JAMES BAY BY LATE IN THE DAY. AN ASSOCIATED STRONG SURFACE COLD FRONT WILL CROSS THE LOWER LAKES WITH A BRIEF PERIOD OF SHOWERS. THE LATEST 00Z MODEL GUIDANCE IS A LITTLE FASTER WITH THE FROPA...SO SHOWERS MAY COME DURING THE FIRST HALF OF THE DAY WITH FALLING TEMPS IN THE AFTERNOON. LATER FRIDAY NIGHT INTO THE WEEKEND VERY CHILLY AIR WILL BECOME ESTABLISHED FROM THE NORTHERN PLAINS INTO THE GREAT LAKES AND NEW ENGLAND. MODEL GUIDANCE CONTINUES TO STRUGGLE WITH THE HANDLING OF A POTENTIAL FRONTAL WAVE. LATEST 00Z GFS SHOWS A RATHER ROBUST FRONTAL WAVE RUNNING THROUGH THE LOWER LAKES LATE FRIDAY NIGHT INTO SATURDAY...WHICH WOULD BRING A WIDESPREAD CHILLY RAIN. THE 00Z ECMWF ALSO HAS A FRONTAL WAVE...JUST A LITTLE WEAKER AND ABOUT 6 HOURS SLOWER. IT ALSO TRIES TO DEVELOP A SECOND FRONTAL WAVE ON SUNDAY AS IT PHASES WITH ADDITIONAL NORTHERN STREAM ENERGY DIGGING INTO THE UPPER GREAT LAKES. GIVEN THE COMPLEXITY OF THE SCENARIO...IT WILL LIKELY BE SEVERAL DAYS BEFORE THE MODEL GUIDANCE SETTLES DOWN AND CONVERGES ON A COMMON SOLUTION. FOR NOW WILL SIMPLY USE CHANCE POPS BOTH DAYS. WHAT IS MUCH HIGHER CONFIDENCE IS THE BELOW NORMAL TEMPERATURES BEGINNING THIS WEEKEND...WITH HIGHS ONLY IN THE LOWER 50S BOTH DAYS ACROSS LOWER ELEVATIONS AND MID TO UPPER 40S ACROSS HIGHER TERRAIN. EVEN THIS MAY BE TOO WARM IF WIDESPREAD CLOUD COVER AND RAIN IS REALIZED. THE CLOUD COVER WILL KEEP OVERNIGHT LOWS ABOVE FREEZING FRIDAY NIGHT AND PROBABLY SATURDAY NIGHT AS WELL. THE COLDEST NIGHT WILL LIKELY BE SUNDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE OHIO VALLEY AND LOWER LAKES WITH CLEARING SKIES AND LIGHTER WINDS. IF THE HIGH DOES INDEED SETTLE OVERHEAD...WIDESPREAD FROST/FREEZE CONDITIONS MAY BE ON THE WAY. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... LOW PRESSURE OVER THE TENNESSEE VALLEY WILL LIFT NORTHWARD INTO THE OHIO VALLEY THROUGH TODAY. AHEAD OF THIS LOW SOME LIGHT SHOWERS ARE SHIFTING ACROSS WESTERN NY AND WILL CONTINUE TO SHIFT NORTH AND EAST THOUGH THE MORNING. LIGHT RA IS BEING REPORTED AT KBUF AND KIAG AT 08Z AND WILL LIKELY REACH KROC BY 09/10Z. OTHERWISE...INCREASING AMOUNTS OF MOISTURE SPREADING NORTH IN ADVANCE OF THE LOW WILL RESULT IN LOWERING VFR CLOUDS THIS MORNING. OVERNIGHT TONIGHT...SOMEWHAT BETTER CHANCES FOR SHOWERS ARE POSSIBLE AS A WARM FRONT LIFTS ACROSS THE STATE. ALONG WITH THIS GUIDANCE IS SHOWING POTENTIALLY SOME IFR CIGS BY LATE THIS EVENING. WILL CONTINUE TO MONITOR AND ADD TO TAFS AS CONFIDENCE INCREASES. OUTLOOK... WEDNESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS. SOME ISOLATED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON. THURSDAY...MAINLY VFR. FRIDAY...VFR/MVFR WITH SOME SHOWERS LIKELY. SATURDAY...VFR/MVFR CHANCE SHOWERS. && .MARINE... LOW PRESSURE WILL LIFT NORTH TOWARD THE OHIO VALLEY TODAY. LIGHT SOUTHERLY WINDS WITH PERIODS OF RAINS SHOWERS ARE EXPECTED TODAY THROUGH WEDNESDAY ACROSS THE LAKES. DRY WEATHER IS EXPECTED THURSDAY BEFORE A STRONG COLD FRONT CROSSES THE LOWER LAKES ON FRIDAY AND USHERS IN THE NEXT PERIOD OF STRONGER WINDS AND A RETURN TO COLDER WEATHER WHICH MAY BRING BACK SCA CONDITIONS. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...SMITH NEAR TERM...SMITH SHORT TERM...HITCHCOCK LONG TERM...HITCHCOCK AVIATION...SMITH MARINE...SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1101 PM EDT WED OCT 3 2012 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL SLOWLY SHIFT OFF THE COAST THURSDAY. SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST UNTIL DRIER AIR ARRIVES DURING THURSDAY. A STRONGER COLD FRONT WILL BRING COOLER AND DRIER AIR SUNDAY...AS CANADIAN HIGH PRESSURE BUILDS INTO THE REGION. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 1045 PM WEDNESDAY...LATEST NAM/RUC RUNS INDICATE SMALL BUT WEAK MID LEVEL VORTICIES EJECTING OUT OF THE GULF OF MEXICO OVERNIGHT...AND MOVING NNE WITHIN THE TROPICAL MOISTURE PLUME. THE DYNAMICS ASSOCIATED WITH THESE VORTICIES WILL ENHANCE CONVECTION BOTH AREAL COVERAGE AND STRENGTH. LOOK FOR THE LEADING S/W TROF MOVING NNE TO REMAIN JUST WEST OF THE FA LATE THIS EVENING. THE FOLLOWING IDENTIFIABLE MID-LEVEL S/W TROF TO AFFECT THE FA DURING THE OVERNIGHT...AND INTO THE DAYLIGHT HOURS OF THU MORNING. THE LATEST HRRR REFLECTIVITY OUTPUT INDICATES A SLIGHTLY SLOWER EASTWARD PROGRESSION OF THE PCPN...BUT OVERALL LOOKS LIKE A WET MORNING FOR THE THU COMMUTE FOR THE MAJORITY OF THE ILM CWA. THE FORECAST AREA WILL REMAIN IN THE SOUPY AIRMASS OVERNIGHT... WITH ONLY VERY MINOR TWEAKS NEEDED FOR OVERNIGHT LOWS DUE TO LATEST DEWPOINTS RUNNING HIGHER BY 1-2 DEGREES. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 2 PM WEDNESDAY...THE OVERALL MID/UPPER PATTERN WILL DE- AMPLIFY BEGINNING THURSDAY AS THE TROUGH TO THE WEST LIFTS QUICKLY NORTHEASTWARD. ZONAL FLOW WILL PREVAIL BY FRIDAY...GRADUALLY SHUNTING THE DEEPER MOISTURE PLUME TO THE EAST. TIME HEIGHT CROSS SECTIONS INDICATE MUCH DRIER AIR TAKING ROOT IN THE H85-H4 LAYER FROM LATE THURSDAY THROUGH FRIDAY. THE OLD FRONT WILL ALSO DRIFT OFF THE COAST THURSDAY. AS A RESULT...THE CHANCES OF RAIN WILL BE DECREASING DURING THURSDAY...WITH NO POPS THURSDAY NIGHT THROUGH FRIDAY NIGHT. ALTHOUGH DEWPOINTS WILL DECREASE THROUGH THE SHORT TERM PERIOD...THE MUCH DRIER AIR WILL REMAIN UPSTREAM BEHIND ANOTHER COLD FRONT APPROACHING THE AREA. MAX/MIN TEMPERATURES WILL RANGE ABOVE NORMAL EACH DAY AND NIGHT. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 2 PM WEDNESDAY...A MODERATELY STRONG BUT LARGELY MOISTURE DEPRIVED COLD FRONT WILL APPROACH FROM THE NORTHWEST WHILE DECELERATING. WAA AHEAD OF THIS BOUNDARY IN THE SW FLOW WILL PUSH HIGHS INTO THE MID 80S SAVE FOR ALONG THE IMMEDIATE COAST. THE FRONT PUSHES THROUGH ON SUNDAY. THE BEST CHANCE FOR SOME RAINFALL HOWEVER SETS UP FOLLOWING FROPA AS THE UPPER LEVEL FRONT REMAINS ACROSS THE CAROLINAS AND SERVES AS A SOURCE OF LIFT ATOP THE UNDERCUTTING SURFACE COOL AIRMASS. MOST OF THIS WILL TRANSPIRE SUNDAY NIGHT. WHILE THE UNDERCUTTING CONTINUES INTO MONDAY THE COLUMN SHOULD START TO DRY ABOVE AND RAIN CHANCES SHOULD DECLINE PERHAPS CONSIDERABLY. HIGH PRESSURE WILL BUILD IN FROM POINTS NORTH AND WEST FOR THE REMAINDER OF THE LONG TERM. THE COOL ADVECTION WILL SHUT DOWN BUT SHALLOW MIXING COULD KEEP THE RETURN OF CLIMO TEMPS A RATHER GRADUAL PROCESS. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... AS OF 00Z...SOME ISOLATED TO SCATTERED SHOWERS ARE POSSIBLE IN THE OVERNIGHT/EARLY MORNING HOURS AS A WEAK FRONTAL BOUNDARY MOVES THROUGH THE CWA. BRIEF PERIODS OF REDUCED VISIBILITIES AND/OR LOWERED CEILINGS COULD BE ASSOCIATED WITH HEAVIER SHOWER ACTIVITY. OTHERWISE VFR CONDITIONS EXPECTED ALONG THE COAST...WITH TEMPO PERIODS OF MVFR CONDITIONS AT THE INLAND TERMINALS. LOW CONFIDENCE IN MVFR/IFR CEILINGS DEVELOPING AT INLAND TERMS WITH FRONTAL PASSAGE. LINGERING SHOWER ACTIVITY IS POSSIBLE DURING THE DAY THURSDAY...BUT CONDITIONS SHOULD IMPROVE TOWARDS THE END OF THE TAF PERIOD. LIGHT SW WINDS OVERNIGHT AND WEST WINDS AROUND 10 KNOTS EXPECTED ON THURSDAY. EXTENDED OUTLOOK...MAINLY VFR CONDITIONS EXPECTED FRIDAY AND INTO THE WEEKEND AS DRIER AIR AND WEAK HIGH PRESSURE MOVE IN OVER THE CAROLINAS. SLIGHT CHANCE OF RAIN LATE SUNDAY AS A STRONGER COLD FRONT MOVES THROUGH THE AREA. OTHERWISE VFR CONDITIONS SHOULD PREVAIL THROUGH THE FORECAST PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM WEDNESDAY...THE SFC PRESSURE PATTERN AND A CONTINUING RELAXING TREND TO THE SFC PG...WILL RESULT IN A S TO SW WIND AROUND 10 KT OVERNIGHT. THE PASSING OF S/W TROFS ALOFT DURING THE OVERNIGHT HRS WILL LIKELY TEMPORARILY INCREASE SFC SPEEDS TO THE 10 TO 15 KT RANGE. SIGNIFICANT SEAS WILL BE IN A CONTINUING SUBSIDING TREND...WITH 2 TO 4 FT COVERING IT...VIA LATEST SWAN RUNS. INITIALLY...WIND DRIVEN WAVES AT 5 TO 7 SECOND PERIODS WILL DOMINATE THE SPECTRUM. HOWEVER...THE 1 TO 2 FOOT 10 TO 12 SECOND PERIOD EASTERLY GROUND SWELL WILL BECOME MORE NOTICEABLE. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 2 PM WEDNESDAY...LIGHT OFFSHORE FLOW THURSDAY WILL VEER TO A NORTHERLY DIRECTION EARLY FRIDAY MORNING AS A WEAK FRONT DRIFTS OFFSHORE. LIGHT AND VARIABLE WIND WILL PREVAIL DURING FRIDAY WITH A VERY WEAK PRESSURE GRADIENT IN PLACE. LIGHT AND VARIABLE CONDITIONS WILL PERSIST THROUGH FRIDAY NIGHT. SEAS WILL HIGHEST THURSDAY MORNING AROUND 3 FT AWAY FROM THE COAST...THEN SUBSIDE TO 1-2 FT THURSDAY NIGHT THROUGH FRIDAY NIGHT. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 2 PM WEDNESDAY...ALTHOUGH A FAIRLY STRONG COLD FRONT WILL BE BEARING DOWN ON THE REGION ON FRIDAY THE PRE FRONTAL FLOW REGIME WILL REMAIN QUITE LAZY THROUGH MOST OF THE DAY. THE BOUNDARY WILL BE DECELERATING AND WEAK HIGH PRESSURE WILL TRY TO HANG ON UNTIL THE LAST MINUTE. A SOUTHERLY WIND DIRECTION WILL BECOME PREDOMINANT AS THE DAY WEARS ON FROM THE FAIRLY VARIABLE WIND OFFERED BY THE EARLIER PARTS OF THE DAY. THE PRE FRONTAL SOUTHWESTERLY FLOW BY SUNDAY WILL INCREASE A FEW KNOTS AS THE BOUNDARY DRAWS EVEN CLOSER AND THEN A FAIRLY SHARP VEER WILL SPREAD GRADUALLY SOUTH ACROSS THE FORECAST ZONES SUNDAY AFTERNOON WITH A TURN TO THE NORTH. WIND REMAINS NORTH TO NORTHEASTERLY ON MONDAY AS THE HIGH BUILDS IN FROM THE NORTH. SUNDAY NIGHT INTO MONDAY SHOULD FEATURE THE ONLY MENTIONABLE BUILDING OF WAVE HEIGHTS AS THE GRADIENT TIGHTENS SLIGHTLY. AT THIS TIME IT APPEARS TO BE A 1 TO 2 FT INCREASE FROM THE RELATIVELY QUIET EARLY PART OF THE LONG TERM FORECAST PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DCH NEAR TERM...DCH SHORT TERM...SRP LONG TERM...MBB AVIATION...MRR/BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
757 PM EDT WED OCT 3 2012 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL SLOWLY SHIFT OFF THE COAST THURSDAY. SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST UNTIL DRIER AIR ARRIVES DURING THURSDAY. A STRONGER COLD FRONT WILL BRING COOLER AND DRIER AIR SUNDAY...AS CANADIAN HIGH PRESSURE BUILDS INTO THE REGION. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 720 PM WEDNESDAY...LATEST NAM RUN INDICATES 1 OR 2 SMALL BUT WEAK MID LEVEL VORTICIES EJECTING OUT OF THE GULF OF MEXICO OVERNIGHT AND MOVING NNE WITHIN THE TROPICAL MOISTURE PLUME. THESE DYNAMICS ASSOCIATED WITH THESE VORTICIES WILL ENHANCE CONVECTION BOTH AREAL COVERAGE AND STRENGTH. LOOK FOR THE LEADING S/W TROF MOVING NNE TO REMAIN JUST WEST OF THE FA THIS EVENING. THE FOLLOWING S/W TROF TO AFFECT THE FA DURING THE OVERNIGHT...AND INTO THE DAYLIGHT HOURS OF THU MORNING. HAVE ADJUSTED POPS ACROSS THE FA TO ACCOMODATE THE MOISTURE PLUME AND UPPER DYNAMICS TIMING...AND ALSO INPUTTING THE LATEST HRRR REFLECTIVITY OUTPUT. FORECAST AREA REMAINS IN THE SOUPY AIRMASS OVERNIGHT...WITH ONLY VERY MINOR TWEAKS NEEDED TO THE OVERNIGHT LOWS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 2 PM WEDNESDAY...THE OVERALL MID/UPPER PATTERN WILL DE- AMPLIFY BEGINNING THURSDAY AS THE TROUGH TO THE WEST LIFTS QUICKLY NORTHEASTWARD. ZONAL FLOW WILL PREVAIL BY FRIDAY...GRADUALLY SHUNTING THE DEEPER MOISTURE PLUME TO THE EAST. TIME HEIGHT CROSS SECTIONS INDICATE MUCH DRIER AIR TAKING ROOT IN THE H85-H4 LAYER FROM LATE THURSDAY THROUGH FRIDAY. THE OLD FRONT WILL ALSO DRIFT OFF THE COAST THURSDAY. AS A RESULT...THE CHANCES OF RAIN WILL BE DECREASING DURING THURSDAY...WITH NO POPS THURSDAY NIGHT THROUGH FRIDAY NIGHT. ALTHOUGH DEWPOINTS WILL DECREASE THROUGH THE SHORT TERM PERIOD...THE MUCH DRIER AIR WILL REMAIN UPSTREAM BEHIND ANOTHER COLD FRONT APPROACHING THE AREA. MAX/MIN TEMPERATURES WILL RANGE ABOVE NORMAL EACH DAY AND NIGHT. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 2 PM WEDNESDAY...A MODERATELY STRONG BUT LARGELY MOISTURE DEPRIVED COLD FRONT WILL APPROACH FROM THE NORTHWEST WHILE DECELERATING. WAA AHEAD OF THIS BOUNDARY IN THE SW FLOW WILL PUSH HIGHS INTO THE MID 80S SAVE FOR ALONG THE IMMEDIATE COAST. THE FRONT PUSHES THROUGH ON SUNDAY. THE BEST CHANCE FOR SOME RAINFALL HOWEVER SETS UP FOLLOWING FROPA AS THE UPPER LEVEL FRONT REMAINS ACROSS THE CAROLINAS AND SERVES AS A SOURCE OF LIFT ATOP THE UNDERCUTTING SURFACE COOL AIRMASS. MOST OF THIS WILL TRANSPIRE SUNDAY NIGHT. WHILE THE UNDERCUTTING CONTINUES INTO MONDAY THE COLUMN SHOULD START TO DRY ABOVE AND RAIN CHANCES SHOULD DECLINE PERHAPS CONSIDERABLY. HIGH PRESSURE WILL BUILD IN FROM POINTS NORTH AND WEST FOR THE REMAINDER OF THE LONG TERM. THE COOL ADVECTION WILL SHUT DOWN BUT SHALLOW MIXING COULD KEEP THE RETURN OF CLIMO TEMPS A RATHER GRADUAL PROCESS. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AS OF 00Z...SOME ISOLATED TO SCATTERED SHOWERS ARE POSSIBLE IN THE OVERNIGHT/EARLY MORNING HOURS AS A WEAK FRONTAL BOUNDARY MOVES THROUGH THE CWA. BRIEF PERIODS OF REDUCED VISIBILITIES AND/OR LOWERED CEILINGS COULD BE ASSOCIATED WITH HEAVIER SHOWER ACTIVITY. OTHERWISE VFR CONDITIONS EXPECTED ALONG THE COAST...WITH TEMPO PERIODS OF MVFR CONDITIONS AT THE INLAND TERMINALS. LOW CONFIDENCE IN MVFR/IFR CEILINGS DEVELOPING AT INLAND TERMS WITH FRONTAL PASSAGE. LINGERING SHOWER ACTIVITY IS POSSIBLE DURING THE DAY THURSDAY...BUT CONDITIONS SHOULD IMPROVE TOWARDS THE END OF THE TAF PERIOD. LIGHT SW WINDS OVERNIGHT AND WEST WINDS AROUND 10 KNOTS EXPECTED ON THURSDAY. EXTENDED OUTLOOK...MAINLY VFR CONDITIONS EXPECTED FRIDAY AND INTO THE WEEKEND AS DRIER AIR AND WEAK HIGH PRESSURE MOVE IN OVER THE CAROLINAS. SLIGHT CHANCE OF RAIN LATE SUNDAY AS A STRONGER COLD FRONT MOVES THROUGH THE AREA. OTHERWISE VFR CONDITIONS SHOULD PREVAIL THROUGH THE FORECAST PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 730 PM WEDNESDAY...THE SFC PRESSURE PATTERN AND A CONTINUING RELAXING TREND TO THE SFC PG...WILL RESULT IN A S TO SW WIND AROUND 10 KT. THE PASSING OF THE S/W TROF ALOFT DURING THE OVERNIGHT HRS WILL LIKELY TEMPORARILY INCREASE SFC SPEEDS IN THE 10 TO 15 KT RANGE. SIGNIFICANT SEAS WILL BE IN A SUBSIDING TREND...WITH 2 TO 4 FT COVERING IT...VIA LATEST SWAN RUNS. INITIALLY...WIND DRIVEN WAVES AT 5 TO 7 SECOND PERIODS WILL DOMINATE THE SPECTRUM. HOWEVER...THE 1 TO 2 FOOT 10 TO 12 SECOND PERIOD EASTERLY GROUND SWELL WILL BECOME MORE NOTICEABLE. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 2 PM WEDNESDAY...LIGHT OFFSHORE FLOW THURSDAY WILL VEER TO A NORTHERLY DIRECTION EARLY FRIDAY MORNING AS A WEAK FRONT DRIFTS OFFSHORE. LIGHT AND VARIABLE WIND WILL PREVAIL DURING FRIDAY WITH A VERY WEAK PRESSURE GRADIENT IN PLACE. LIGHT AND VARIABLE CONDITIONS WILL PERSIST THROUGH FRIDAY NIGHT. SEAS WILL HIGHEST THURSDAY MORNING AROUND 3 FT AWAY FROM THE COAST...THEN SUBSIDE TO 1-2 FT THURSDAY NIGHT THROUGH FRIDAY NIGHT. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 2 PM WEDNESDAY...ALTHOUGH A FAIRLY STRONG COLD FRONT WILL BE BEARING DOWN ON THE REGION ON FRIDAY THE PRE FRONTAL FLOW REGIME WILL REMAIN QUITE LAZY THROUGH MOST OF THE DAY. THE BOUNDARY WILL BE DECELERATING AND WEAK HIGH PRESSURE WILL TRY TO HANG ON UNTIL THE LAST MINUTE. A SOUTHERLY WIND DIRECTION WILL BECOME PREDOMINANT AS THE DAY WEARS ON FROM THE FAIRLY VARIABLE WIND OFFERED BY THE EARLIER PARTS OF THE DAY. THE PRE FRONTAL SOUTHWESTERLY FLOW BY SUNDAY WILL INCREASE A FEW KNOTS AS THE BOUNDARY DRAWS EVEN CLOSER AND THEN A FAIRLY SHARP VEER WILL SPREAD GRADUALLY SOUTH ACROSS THE FORECAST ZONES SUNDAY AFTERNOON WITH A TURN TO THE NORTH. WIND REMAINS NORTH TO NORTHEASTERLY ON MONDAY AS THE HIGH BUILDS IN FROM THE NORTH. SUNDAY NIGHT INTO MONDAY SHOULD FEATURE THE ONLY MENTIONABLE BUILDING OF WAVE HEIGHTS AS THE GRADIENT TIGHTENS SLIGHTLY. AT THIS TIME IT APPEARS TO BE A 1 TO 2 FT INCREASE FROM THE RELATIVELY QUIET EARLY PART OF THE LONG TERM FORECAST PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DCH NEAR TERM...DCH SHORT TERM...SRP LONG TERM...MBB AVIATION...MRR/BJR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
755 PM EDT WED OCT 3 2012 .SYNOPSIS... WEAK HIGH PRESSURE TONIGHT...EVEN AS AN UPPER LEVEL DISTURBANCE PASSES BRINGING SHOWERS TO EAST. A COLD FRONT PASSES LATE FRIDAY AFTERNOON AND FRIDAY NIGHT. LOW PRESSURE WAVE FOR THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... 730 PM UPDATE...QUITE A BIT OF PRECIP DEPICTED ON LOCAL AND SURROUNDING RADARS WITH LITTLE SHOWING UP IN SFC OBS. ROA AND HSP HAVE REPORTED LIGHT RAIN IN THE PAST HOUR. VAD WIND AND RADAR IMAGERY SHOW THAT MUCH OF WHAT/S SHOWING UP IS INDEED VIRGA AND HAVING A TOUGH TIME FALLING BELOW 15KFT AGL. LATEST RUC SEEMS TO BE PICKING UP THIS OFF-SFC DRY LAYER WELL...CENTERED ROUGHLY AROUND 700MB. THIS LAYER WILL CONTINUE TO FILL WITH NEAR SATURATION AFTER 06Z AND ESPECIALLY BY 09Z. ONGOING FORECAST LOOKS GOOD WITH REGARD TO POPS MAINLY ACROSS THE EASTERN HIGH TERRAIN. DID INCREASE SKY COVER PER RECENT SATELLITE TRENDS. PREVIOUS DISCUSSION... OVERALL...QUIETER WEATHER TODAY AS COMPARED TO YESTERDAY AS WEAK SURFACE HIGH PRESSURE IS IN CONTROL. PLENTY OF CLOUD COVER STILL ACROSS THE FORECAST AREA AS THE REGION REMAINS SANDWICHED BETWEEN AN UPPER TROUGH OVER THE MISSISSIPPI VALLEY...AND UPPER RIDGE IN WESTERN ATLANTIC...WITH A SOUTHWESTERLY FLOW OVER THE CWA. SOME OF THE CLOUD COVER IS ERODING OVER WESTERN ZONES...BUT CLOUD COVER WILL INCREASE AGAIN TONIGHT. WILL FINALLY START TO SEE A PATTERN CHANGE BEGIN LATE TONIGHT/TOMORROW AS UPPER LOW ACROSS MISSISSIPPI VALLEY OPENS INTO A WAVE...AND MOVES NORTHEAST INTO THE OHIO VALLEY AS A SHORTWAVE CURRENTLY NEAR MONTANA DEEPENS AND PUSHES EAST...EVENTUALLY AFFECTING US LATER THIS WEEK/WEEKEND. THIS...IN COMBINATION WITH UPPER WAVES...INCREASING MOISTURE AND OROGRAPHIC ENHANCEMENT WILL CREATE A CHANCE FOR SHOWERS OVERNIGHT AND THURSDAY MORNING...PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES...BUT COULD SPREAD FARTHER WEST INTO THE LOWLAND COUNTIES OF WV. UPPER TROUGH WILL PUSH TO THE EAST BY LATE THURSDAY AFTERNOON...WITH ANY PRECIPITATION PUSHING EAST WITH IT. PRECIPITATION MAY EVEN TAPER OFF TO DRIZZLE LATER IN THE DAY THURSDAY ACROSS THE NORTHERN MOUNTAIN ZONES AS DRIER AIR AT MID AND UPPER LEVELS WORKS ITS WAY INTO THE AREA. NOT EXPECTING MUCH IN TERMS OF FOG DEVELOPMENT TONIGHT...EXCEPT MAYBE WESTERN/NORTHERN ZONES WHERE BETTER CLEARING WILL TAKE PLACE...PARTICULARLY TOWARDS/AFTER DAYBREAK. DID ELECT TO RAISE OVERNIGHT LOW TEMPERATURES ACROSS THE SOUTH/EAST SLIGHTLY FROM PREVIOUS FORECAST DUE TO AN INCREASE IN THE FORECAST AMOUNT OF CLOUD COVER. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... NO EARTH SHAKING CHANGES FOR THIS TIME FRAME. DID TRY TO SLOW DOWN THE SLOW ADVANCEMENT OF THE CHANCE POPS E AND SE LATE FRIDAY AFTERNOON AND FRIDAY EVENING. SO FRIDAY SHOULD BE A WARM OCTOBER DAY. WILL BASE THIS FORECAST ON THE SURFACE COLD FRONT TO BE NEAR THE OHIO RIVER IN THE VCNTY OF PKB AND HTS AT 00Z SATURDAY. SO WILL LIMIT THE EASTWARD EXTENT OF THE CHANCE POP TO THOSE OHIO RIVER COUNTIES BY 00Z SATURDAY. MODEL SOUNDINGS STILL DO NOT SUPPORT A MENTION OF THUNDER WITH FRONT. THE SURFACE FRONT SHOULD CONTINUE TO CONTINUE TO DROP SOUTHEAST OVERNIGHT FRIDAY NIGHT...HAVE FRONT NEAR BKW BY 12Z SATURDAY...THEN REACHING INTO SOUTHWEST VIRGINIA DURING THE DAY ON SATURDAY. AS A RESULT...THE SHALLOW COLDER AIR BELOW THE FRONTAL INVERSION WILL BE FELT IN THE WAKE OF THE FRONT. SO BOTH THE LOW TEMPERATURES FRIDAY NIGHT AND THE HIGH TEMPERATURES ON SATURDAY ARE TOUGH TO FIGURE. YET...READING WILL NOT BE GOING UP MUCH ON SATURDAY. TEMPERATURES AOA 3500 FEET COULD EVEN BE FALLING 12Z SATURDAY TO 18Z SATURDAY...BUT DID NOT INCLUDE THAT AT THIS DISTANCE IN TIME. ALSO PICTURING LOWER CLOUDS AND SPOTTY LIGHT RAIN...MAYBE EVEN SOME DRIZZLE...IN THE WAKE OF THE FRONT ON SATURDAY. HAVE POPS LOWERING A BIT OVER PORTIONS OF SOUTHEAST OHIO DURING THE DAY ON SATURDAY... BEFORE WAVE APPROACHES SATURDAY NIGHT. DO NOT SEE A LOT OF MID LEVEL SUPPORT DURING THE DAY ON SATURDAY...SO RAIN AMOUNTS SHOULD BE LIGHT...BEFORE INCREASING SATURDAY NIGHT. FOR THE CHARACTER OF THE PCPN...WILL MENTION RAIN SHOWERS FRIDAY NIGHT...THEN STRATIFORM PCPN SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... BY SATURDAY NIGHT...THE GFS/ECMWF BRING A SHALLOW SFC COLD FRONT... OVER THE EASTERN MOUNTAINS...WITH PCPN LAGGING BEHIND. DRY AND COLD AIR AT H85 WILL PUSH ALL PCPN EAST UNDER NORTHWEST FLOW AND A SECONDARY COLD FRONT...AS SEEN ON THE THETA-E GRADIENT BY SUNDAY AFTERNOON. THERE COULD BE SOME UPSLOPE COMPONENT ON PCPN INTENSITY AND DURATION UNDER THIS FLOW...BUT EXPECT ALL PCPN BEEN LIQUID ATTM. THEREFORE...KEPT HIGH LIKELY POPS IN STRATIFORM RAIN WESTERN SLOPES AND EAST...WHILE HIGH CHANCE POPS FURTHER WEST IN RESPONSE OF A STRONG H5 SHORT WAVE AFFECTING THE AREA SUNDAY...DESPITE OF LIMITED MOISTURE AVAILABLE. PERHAPS SNOWSHOE COULD SEE THEIR FIRST FLURRIES...BUT WITH WARM SOILS...SO ACCUMULATIONS ARE EXPECTED. LATEST GFS/NAM H85 FREEZING LINE ARE COMPARABLE OVER CENTRAL OH BY 00Z SUNDAY...AND THE GFS LOOKS FASTER THAN THE ECMWF WITH 0C DEGREE LINE ALONG THE APPALACHIANS BY 18Z SUNDAY...WHILE THE OLD ECMWF LAGS ABOUT 12 HOURS. THEREFORE...WENT CLOSER TO THE GFS WITH PCPN TIMING AND LOCATION AS COMPARED WITH THE MOST MAJORITY OF THE ENSEMBLE MEMBERS AND THE SREF. TEMPERATURES THIS SUNDAY AND MONDAY WILL BE IN THE LOW TO MID 30S UNDER CLEAR SKIES AND CALM FLOW. THIS CONDITIONS COULD PRODUCE AREAS OF WIDESPREAD FROST SUNDAY NIGHT INTO MONDAY MORNING....AND AGAIN MONDAY NIGHT INTO TUESDAY MORNING...BUT MAINLY HIGHER ELEVATIONS AND PORTIONS OF SOUTHEAST OH. HIGH PRESSURE WILL BRING DRY AND CHILLY NIGHTS FOR THE REST OF THE WEEK. ROLLED MAINLY WITH HPC TEMPS GUIDANCE THROUGH THE PERIOD...TWEAKING SOME TOWARDS THE MICRO CLIMATES AT HIGHER ELEVATIONS UNDER SUB FREEZING TEMPS ALOFT...SUN AND MON. TEMPS WILL GRADUALLY WARM UP THROUGH THE END OF THE WEEK. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... 18Z WEDNESDAY THROUGH 18Z THURSDAY... CLOUDS WILL CONTINUE TO INCREASE AND LOWER THIS EVENING AND OVERNIGHT WITH SHOWERS POSSIBLE...MAINLY ALONG AND EAST OF A LINE FROM CRW TO CKB...AS AN UPPER LEVEL DISTURBANCE MOVES OVER THE AREA. BRIEF MVFR CONDITIONS ARE POSSIBLE IN VICINITY OF SHOWERS. NO THUNDER IS EXPECTED HOWEVER. NOT EXPECTING WIDESPREAD FOG ACTIVITY OVERNIGHT DUE TO THE INCREASE IN CLOUD COVER FROM UPPER DISTURBANCE...ALTHOUGH BRIEF FOG CONDITIONS MAY BE POSSIBLE AFTER 09Z WEST OF A LINE FROM CRW TO CKB WHERE SOME CLEARING MAY TAKE PLACE TOWARDS THE NEAR-DAWN HOURS. CONDITIONS WILL IMPROVE TO VFR AREA WIDE AFTER 15Z AS THE DISTURBANCE MOVES EAST OF THE AREA. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING AND EXTENT OF MVFR CONDITIONS OVERNIGHT MAY VARY FROM CURRENT FORECAST. LOW CIGS OVER HIGHER TERRAIN SITES SUCH AS AT KEKN AND KBKW MAY TAKE LONGER TO LIFT TO VFR THAN CURRENTLY FORECAST. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE THU 10/04/12 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H L BKW CONSISTENCY H H H M M M M M M H M M EKN CONSISTENCY M M M M M M H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H M H H H H H H H H AFTER 00Z FRIDAY... IFR FOG POSSIBLE FRIDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/ARJ/SL NEAR TERM...50/SL SHORT TERM...KTB LONG TERM...ARJ AVIATION...50
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
743 AM EDT TUE OCT 2 2012 .SYNOPSIS... LOW PRESSURE MOVING NORTHWARD THROUGH THE OHIO VALLEY TODAY AND TONIGHT WILL PUSH A COMPLICATED FRONTAL SYSTEM THROUGH THE STATE. HIGH PRESSURE BUILDS IN FROM THE SOUTH AND WARMER THAN NORMAL TEMPERATURES ARE IN STORE FOR WEDNESDAY INTO FRIDAY. SHOWERS AND COOLER TEMPERATURES WILL LIKELY RETURN FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGHER MOISTURE CONTINUES TO FLOW UP INTO THE REGION AS THE RIDGE PUMPS UP ALONG/OFF THE EAST COAST. SLUG OF RAIN ON THE RADAR MOSAIC IS WELL-HANDLED BY THE RUC AND TO A LESSER EXTENT BUT STILL FAIRLY WELL BY THE NEWEST/06Z NAM. NO LIGHTNING IN THIS AREA OF RAIN...BUT ELEVATED INSTABILITY WILL LIKELY DEVELOP THROUGH THE DAY ON 40-45KT 8H-7H WINDS. CLOUDS WILL WORK AGAINST SFC-BASED INSTABILITY...BUT WILL CONTINUE TO MENTION T IN THE FCST FOR THE DAY. THE WIND PROFILE FOR THE DAY FEATURES A SLOWLY TURNING HODOGRAPH AND 70+KT SW STORM TOP WINDS. AS THE WARM/OCCLUDED FRONT IS SPIRALED INTO THE WRN MTS LATER TODAY...A STRONGER STORM IS POSSIBLE. WILL NOT MENTION ANY THREATS IN THE HWO FOR NOW...AS CLOUD COVER IS GOING TO BE THICK FOR MOST OF THE DAY. WILL KEEP MAXES NEAR OR EVEN JUST SLIGHTLY ABOVE NORMAL IN THE M60S-L70S. THE HEAVIEST OF THE RAIN/SHOWERS WILL BE DURING THE DAYLIGHT HRS. QPF OF AROUND A HALF OF AN INCH IS STILL THE BEST CALL...AS VERY FEW 03Z SREF MEMBERS PLACE AN INCH OR MORE INTO OUR CWA. BUT THE PWATS ARE NEAR AN INCH AND A HALF UPSTREAM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... DYNAMICS DISAPPEAR THIS EVENING...AND THE RAIN SHOULD BECOME MORE-SHOWERY AND COVERAGE BECOME SPARSE. CLOUDS AND LIGHT SERLY FLOW TUES NIGHT WILL KEEP TEMPS MILD THRU THE NIGHT. TEMPS WILL THEN HAVE THE POSSIBILITY OF RISING ABOUT 10 DEGS ABOVE NORMALS ON WED AFTN AS THE SUBTROPICAL HIGH NOSES IN FROM THE SOUTH. 8H TEMPS IN THE MID TEENS ON WED COULD ALLOW THE TEMPS TO GET 10-15F ABOVE NORMAL ON WED -- IF THE CLOUDS AND LEFT OVER SHOWERS GET OUT OF THE WAY. THE SFC WINDS VEER FROM SE TO SW DURING THE DAY...WHICH IS USUALLY A GOOD DIRECTION FOR DOWNSLOPE AND THEREFORE A BETTER CHANCE AT CLEARING UP AT LEAST THE SERN COS. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... GENERAL FLOW PATTERN/MODEL PREFERENCES ====================================== THE OCT 01/12Z OPERATIONAL AND ENSEMBLE GUIDANCE IS IN GENERAL AGREEMENT CONCERNING THE LARGE SCALE FLOW PATTERN...WHICH LEADS TO AVERAGE CONFIDENCE DURING THE PERIOD. MS VLY TROUGH WILL DEAMPLIFY AS IT ACCELERATES NEWD THROUGH THE OH VLY/ERN GREAT LAKES THUR. AT THE SURFACE...A WEAK OCCLUDED LOW AND ATTENDANT FRONT WILL SHIFT NEWD ACRS THE NRN MID-ATLC STATES WED BEFORE A RIDGE OF HIGH PRES SETS UP ALONG THE APPALACHIAN SPINE ON THURS. ERN PAC REX BLOCK WILL MIGRATE EWD TWD THE WEST COAST DURING THE SECOND HALF OF THE PERIOD...WITH ABOVE NORMAL HEIGHTS PERSISTING OVR SERN ALASKA/NW BRITISH COLUMBIA. THIS WILL LEAD TO INCREASED TROUGHING INITIALLY OVER THE CANADIAN PRAIRIES AND N-CENTRAL STATES BEFORE EXPANDING DOWNSTREAM INTO THE ERN CONUS. IN TERMS OF INDIVIDUAL MODEL SOLUTIONS...THE LATEST GFS/GEFS SHOW SLIGHTLY GREATER AMPLITUDE/DIGGING WITH THE MID-UPPER LEVEL TROUGH THAN THE EC/ECENS AND CMC/CMCE. HPC WEIGHTED THE GFS HIGHER IN THEIR FINAL BLEND FOR SFC PRESSURES...WHICH SEEMS REASONABLE CONSIDERING THE MAGNITUDE OF UPSTREAM RIDGE...WHICH MAY BE ENHANCED BY APPROACH OF SEVERAL PAC SYSTEMS FORMERLY OF TROPICAL ORIGIN AS TYPHOONS. THIS SOLUTION RESULTS IN A MORE SUPPRESSED TRACK OF FRONTAL WAVE THIS WEEKEND...WHICH IS A NOTABLE DIFFERENCE BETWEEN THE DETERMINISTIC GFS AND EC/CMC. SENSIBLE WEATHER HIGHLIGHTS =========================== MODEL DATA SHOWS SHOWERS COMING TO AN END BY WED NGT...AS SFC OCCLD FNT SHIFTS NEWD AND UPPER LEVEL DRY SLOT ARRIVES FROM THE SW. MUCH ABV NORMAL TEMPS ARE ANTICIPATED ON THURS WITH HIGHS IN THE 70S OVR THE MTNS AND NR 80F IN THE LWR SUSQ VLY. SFC RIDGE SHOULD PROVIDE DRY WEATHER ON THURS. COMPACT SHORTWAVE DIGGING ACRS THE UPPER GRT LKS WILL SEND A MSTR-STARVED COLD FRONT SEWD THROUGH THE REGION ON FRIDAY...ACCOMPANIED BY SCT LGT SHOWERS. MODELS DIVERGE INTO THE WEEKEND CONCERNING A FRONTAL WAVE EJECTING EWD FM THE SRN ROCKIES...WHICH MAY LEAD TO SIGNIFICANT CHANGES TO THE FORECAST AT SHORTER RANGES. CONSENSUS MODEL DATA DOES SUPPORT COOLING TREND INTO EARLY NEXT WEEK WITH BELOW NORMAL STANDARDIZED ANOMALIES WITHIN THE 500MB HEIGHT AND 850MB TEMPERATURE FIELDS. THIS MIGHT LEAD TO THE FIRST SNOW SHOWERS OF THE SEASON OVR THE NW MTNS...WHICH IS NOT UNUSUAL FOR EARLY OCTOBER. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... LARGE AREA OF SHOWERS OVER THE AREA. STILL A WIDE RANGE OF CONDITIONS...BUT OVERALL IFR AND LIFR CONDITIONS WILL PREVAIL FOR MUCH OF TODAY INTO WED MORNING. A WARM FRONT APPROACHING FROM THE SOUTH WILL CONTINUE TO SPREAD LOWERING CLOUDS AND SHRA OVER THE AREA THIS MORNING. LITTLE IMPROVEMENT IS EXPECTED THIS AFTERNOON...AS CENTRAL PA WILL REMAIN IN MOIST...SERLY FLOW NORTH OF WARM FRONT. OCNL -RA/DZ MAY TAPER OFF BY LATE AFTN. HOWEVER...MDL DATA CONTINUES TO INDICATE A LIKELIHOOD OF IFR CIGS PERSISTING INTO AT LEAST THIS AFTERNOON. OUTLOOK... WED...AM LOW CIGS/FOG POSSIBLE...MAINLY EARLY. THU...AM LOW CIGS/FOG POSSIBLE EAST. FRI...NO SIG WX EXPECTED EARLY...THEN A CHC OF SHOWERS LATE... MAINLY NW. SAT...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/RXR NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...STEINBUGL AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
546 AM EDT TUE OCT 2 2012 .SYNOPSIS... LOW PRESSURE MOVING NORTHWARD THROUGH THE OHIO VALLEY TODAY AND TONIGHT WILL PUSH A COMPLICATED FRONTAL SYSTEM THROUGH THE STATE. HIGH PRESSURE BUILDS IN FROM THE SOUTH AND WARMER THAN NORMAL TEMPERATURES ARE IN STORE FOR WEDNESDAY INTO FRIDAY. SHOWERS AND COOLER TEMPERATURES WILL LIKELY RETURN FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGHER MOISTURE CONTINUES TO FLOW UP INTO THE REGION AS THE RIDGE PUMPS UP ALONG/OFF THE EAST COAST. SLUG OF RAIN ON THE RADAR MOSAIC IS WELL-HANDLED BY THE RUC AND TO A LESSER EXTENT BUT STILL FAIRLY WELL BY THE NEWEST/06Z NAM. NO LIGHTNING IN THIS AREA OF RAIN...BUT ELEVATED INSTABILITY WILL LIKELY DEVELOP THROUGH THE DAY ON 40-45KT 8H-7H WINDS. CLOUDS WILL WORK AGAINST SFC-BASED INSTABILITY...BUT WILL CONTINUE TO MENTION T IN THE FCST FOR THE DAY. THE WIND PROFILE FOR THE DAY FEATURES A SLOWLY TURNING HODOGRAPH AND 70+KT SW STORM TOP WINDS. AS THE WARM/OCCLUDED FRONT IS SPIRALED INTO THE WRN MTS LATER TODAY...A STRONGER STORM IS POSSIBLE. WILL NOT MENTION ANY THREATS IN THE HWO FOR NOW...AS CLOUD COVER IS GOING TO BE THICK FOR MOST OF THE DAY. WILL KEEP MAXES NEAR OR EVEN JUST SLIGHTLY ABOVE NORMAL IN THE M60S-L70S. THE HEAVIEST OF THE RAIN/SHOWERS WILL BE DURING THE DAYLIGHT HRS. QPF OF AROUND A HALF OF AN INCH IS STILL THE BEST CALL...AS VERY FEW 03Z SREF MEMBERS PLACE AN INCH OR MORE INTO OUR CWA. BUT THE PWATS ARE NEAR AN INCH AND A HALF UPSTREAM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... DYNAMICS DISAPPEAR THIS EVENING...AND THE RAIN SHOULD BECOME MORE-SHOWERY AND COVERAGE BECOME SPARSE. CLOUDS AND LIGHT SERLY FLOW TUES NIGHT WILL KEEP TEMPS MILD THRU THE NIGHT. TEMPS WILL THEN HAVE THE POSSIBILITY OF RISING ABOUT 10 DEGS ABOVE NORMALS ON WED AFTN AS THE SUBTROPICAL HIGH NOSES IN FROM THE SOUTH. 8H TEMPS IN THE MID TEENS ON WED COULD ALLOW THE TEMPS TO GET 10-15F ABOVE NORMAL ON WED -- IF THE CLOUDS AND LEFT OVER SHOWERS GET OUT OF THE WAY. THE SFC WINDS VEER FROM SE TO SW DURING THE DAY...WHICH IS USUALLY A GOOD DIRECTION FOR DOWNSLOPE AND THEREFORE A BETTER CHANCE AT CLEARING UP AT LEAST THE SERN COS. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... GENERAL FLOW PATTERN/MODEL PREFERENCES ====================================== THE OCT 01/12Z OPERATIONAL AND ENSEMBLE GUIDANCE IS IN GENERAL AGREEMENT CONCERNING THE LARGE SCALE FLOW PATTERN...WHICH LEADS TO AVERAGE CONFIDENCE DURING THE PERIOD. MS VLY TROUGH WILL DEAMPLIFY AS IT ACCELERATES NEWD THROUGH THE OH VLY/ERN GREAT LAKES THUR. AT THE SURFACE...A WEAK OCCLUDED LOW AND ATTENDANT FRONT WILL SHIFT NEWD ACRS THE NRN MID-ATLC STATES WED BEFORE A RIDGE OF HIGH PRES SETS UP ALONG THE APPALACHIAN SPINE ON THURS. ERN PAC REX BLOCK WILL MIGRATE EWD TWD THE WEST COAST DURING THE SECOND HALF OF THE PERIOD...WITH ABOVE NORMAL HEIGHTS PERSISTING OVR SERN ALASKA/NW BRITISH COLUMBIA. THIS WILL LEAD TO INCREASED TROUGHING INITIALLY OVER THE CANADIAN PRAIRIES AND N-CENTRAL STATES BEFORE EXPANDING DOWNSTREAM INTO THE ERN CONUS. IN TERMS OF INDIVIDUAL MODEL SOLUTIONS...THE LATEST GFS/GEFS SHOW SLIGHTLY GREATER AMPLITUDE/DIGGING WITH THE MID-UPPER LEVEL TROUGH THAN THE EC/ECENS AND CMC/CMCE. HPC WEIGHTED THE GFS HIGHER IN THEIR FINAL BLEND FOR SFC PRESSURES...WHICH SEEMS REASONABLE CONSIDERING THE MAGNITUDE OF UPSTREAM RIDGE...WHICH MAY BE ENHANCED BY APPROACH OF SEVERAL PAC SYSTEMS FORMERLY OF TROPICAL ORIGIN AS TYPHOONS. THIS SOLUTION RESULTS IN A MORE SUPPRESSED TRACK OF FRONTAL WAVE THIS WEEKEND...WHICH IS A NOTABLE DIFFERENCE BETWEEN THE DETERMINISTIC GFS AND EC/CMC. SENSIBLE WEATHER HIGHLIGHTS =========================== MODEL DATA SHOWS SHOWERS COMING TO AN END BY WED NGT...AS SFC OCCLD FNT SHIFTS NEWD AND UPPER LEVEL DRY SLOT ARRIVES FROM THE SW. MUCH ABV NORMAL TEMPS ARE ANTICIPATED ON THURS WITH HIGHS IN THE 70S OVR THE MTNS AND NR 80F IN THE LWR SUSQ VLY. SFC RIDGE SHOULD PROVIDE DRY WEATHER ON THURS. COMPACT SHORTWAVE DIGGING ACRS THE UPPER GRT LKS WILL SEND A MSTR-STARVED COLD FRONT SEWD THROUGH THE REGION ON FRIDAY...ACCOMPANIED BY SCT LGT SHOWERS. MODELS DIVERGE INTO THE WEEKEND CONCERNING A FRONTAL WAVE EJECTING EWD FM THE SRN ROCKIES...WHICH MAY LEAD TO SIGNIFICANT CHANGES TO THE FORECAST AT SHORTER RANGES. CONSENSUS MODEL DATA DOES SUPPORT COOLING TREND INTO EARLY NEXT WEEK WITH BELOW NORMAL STANDARDIZED ANOMALIES WITHIN THE 500MB HEIGHT AND 850MB TEMPERATURE FIELDS. THIS MIGHT LEAD TO THE FIRST SNOW SHOWERS OF THE SEASON OVR THE NW MTNS...WHICH IS NOT UNUSUAL FOR EARLY OCTOBER. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... CONDITIONS WENT DOWNHILL FAST. NOW A LARGE AREA OF STEADY RAIN MOVING IN. 09Z TAFS ADJUSTED FOR THIS. A WARM FRONT APPROACHING FROM THE SOUTH WILL CONTINUE TO SPREAD LOWERING CLOUDS AND SHRA OVER THE AREA THIS MORNING. LITTLE IMPROVEMENT IS EXPECTED THIS AFTERNOON...AS CENTRAL PA WILL REMAIN IN MOIST...SERLY FLOW NORTH OF WARM FRONT. OCNL -RA/DZ MAY TAPER OFF BY AFTN. HOWEVER...MDL DATA CONTINUES TO INDICATE A LIKELIHOOD OF IFR CIGS PERSISTING ALONG THE EAST SLOPES OF THE APPALACHIANS... INCLUDING BFD/UNV/AOO/JST. OUTLOOK... WED...AM LOW CIGS/FOG POSSIBLE. THU...AM LOW CIGS/FOG POSSIBLE EAST. FRI...NO SIG WX EXPECTED EARLY...THEN A CHC OF SHOWERS LATE...MAINLY NW. SAT...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/RXR NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...STEINBUGL AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
510 AM EDT TUE OCT 2 2012 .SYNOPSIS... LOW PRESSURE MOVING NORTHWARD THROUGH THE OHIO VALLEY TODAY AND TONIGHT WILL PUSH A COMPLICATED FRONTAL SYSTEM THROUGH THE STATE. HIGH PRESSURE BUILDS IN FROM THE SOUTH AND WARMER THAN NORMAL TEMPERATURES ARE IN STORE FOR WEDNESDAY INTO FRIDAY. SHOWERS AND COOLER TEMPERATURES WILL LIKELY RETURN FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGHER MOISTURE CONTINUES TO FLOW UP INTO THE REGION AS THE RIDGE PUMPS UP ALONG/OFF THE EAST COAST. SLUG OF RAIN ON THE RADAR MOSAIC IS WELL-HANDLED BY THE RUC AND TO A LESSER EXTENT BUT STILL FAIRLY WELL BY THE NEWEST/06Z NAM. NO LIGHTNING IN THIS AREA OF RAIN...BUT ELEVATED INSTABILITY WILL LIKELY DEVELOP THROUGH THE DAY ON 40-45KT 8H-7H WINDS. CLOUDS WILL WORK AGAINST SFC-BASED INSTABILITY...BUT WILL CONTINUE TO MENTION T IN THE FCST FOR THE DAY. THE WIND PROFILE FOR THE DAY FEATURES A SLOWLY TURNING HODOGRAPH AND 70+KT SW STORM TOP WINDS. AS THE WARM/OCCLUDED FRONT IS SPIRALED INTO THE WRN MTS LATER TODAY...A STRONGER STORM IS POSSIBLE. WILL NOT MENTION ANY THREATS IN THE HWO FOR NOW...AS CLOUD COVER IS GOING TO BE THICK FOR MOST OF THE DAY. WILL KEEP MAXES NEAR OR EVEN JUST SLIGHTLY ABOVE NORMAL IN THE M60S-L70S. THE HEAVIEST OF THE RAIN/SHOWERS WILL BE DURING THE DAYLIGHT HRS. QPF OF AROUND A HALF OF AN INCH IS STILL THE BEST CALL...AS VERY FEW 03Z SREF MEMBERS PLACE AN INCH OR MORE INTO OUR CWA. BUT THE PWATS ARE NEAR AN INCH AND A HALF UPSTREAM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... DYNAMICS DISAPPEAR THIS EVENING...AND THE RAIN SHOULD BECOME MORE-SHOWERY AND COVERAGE BECOME SPARSE. CLOUDS AND LIGHT SERLY FLOW TUES NIGHT WILL KEEP TEMPS MILD THRU THE NIGHT. TEMPS WILL THEN HAVE THE POSSIBILITY OF RISING ABOUT 10 DEGS ABOVE NORMALS ON WED AFTN AS THE SUBTROPICAL HIGH NOSES IN FROM THE SOUTH. 8H TEMPS IN THE MID TEENS ON WED COULD ALLOW THE TEMPS TO GET 10-15F ABOVE NORMAL ON WED -- IF THE CLOUDS AND LEFT OVER SHOWERS GET OUT OF THE WAY. THE SFC WINDS VEER FROM SE TO SW DURING THE DAY...WHICH IS USUALLY A GOOD DIRECTION FOR DOWNSLOPE AND THEREFORE A BETTER CHANCE AT CLEARING UP AT LEAST THE SERN COS. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... GENERAL FLOW PATTERN/MODEL PREFERENCES ====================================== THE OCT 01/12Z OPERATIONAL AND ENSEMBLE GUIDANCE IS IN GENERAL AGREEMENT CONCERNING THE LARGE SCALE FLOW PATTERN...WHICH LEADS TO AVERAGE CONFIDENCE DURING THE PERIOD. MS VLY TROUGH WILL DEAMPLIFY AS IT ACCELERATES NEWD THROUGH THE OH VLY/ERN GREAT LAKES THUR. AT THE SURFACE...A WEAK OCCLUDED LOW AND ATTENDANT FRONT WILL SHIFT NEWD ACRS THE NRN MID-ATLC STATES WED BEFORE A RIDGE OF HIGH PRES SETS UP ALONG THE APPALACHIAN SPINE ON THURS. ERN PAC REX BLOCK WILL MIGRATE EWD TWD THE WEST COAST DURING THE SECOND HALF OF THE PERIOD...WITH ABOVE NORMAL HEIGHTS PERSISTING OVR SERN ALASKA/NW BRITISH COLUMBIA. THIS WILL LEAD TO INCREASED TROUGHING INITIALLY OVER THE CANADIAN PRAIRIES AND N-CENTRAL STATES BEFORE EXPANDING DOWNSTREAM INTO THE ERN CONUS. IN TERMS OF INDIVIDUAL MODEL SOLUTIONS...THE LATEST GFS/GEFS SHOW SLIGHTLY GREATER AMPLITUDE/DIGGING WITH THE MID-UPPER LEVEL TROUGH THAN THE EC/ECENS AND CMC/CMCE. HPC WEIGHTED THE GFS HIGHER IN THEIR FINAL BLEND FOR SFC PRESSURES...WHICH SEEMS REASONABLE CONSIDERING THE MAGNITUDE OF UPSTREAM RIDGE...WHICH MAY BE ENHANCED BY APPROACH OF SEVERAL PAC SYSTEMS FORMERLY OF TROPICAL ORIGIN AS TYPHOONS. THIS SOLUTION RESULTS IN A MORE SUPPRESSED TRACK OF FRONTAL WAVE THIS WEEKEND...WHICH IS A NOTABLE DIFFERENCE BETWEEN THE DETERMINISTIC GFS AND EC/CMC. SENSIBLE WEATHER HIGHLIGHTS =========================== MODEL DATA SHOWS SHOWERS COMING TO AN END BY WED NGT...AS SFC OCCLD FNT SHIFTS NEWD AND UPPER LEVEL DRY SLOT ARRIVES FROM THE SW. MUCH ABV NORMAL TEMPS ARE ANTICIPATED ON THURS WITH HIGHS IN THE 70S OVR THE MTNS AND NR 80F IN THE LWR SUSQ VLY. SFC RIDGE SHOULD PROVIDE DRY WEATHER ON THURS. COMPACT SHORTWAVE DIGGING ACRS THE UPPER GRT LKS WILL SEND A MSTR-STARVED COLD FRONT SEWD THROUGH THE REGION ON FRIDAY...ACCOMPANIED BY SCT LGT SHOWERS. MODELS DIVERGE INTO THE WEEKEND CONCERNING A FRONTAL WAVE EJECTING EWD FM THE SRN ROCKIES...WHICH MAY LEAD TO SIGNIFICANT CHANGES TO THE FORECAST AT SHORTER RANGES. CONSENSUS MODEL DATA DOES SUPPORT COOLING TREND INTO EARLY NEXT WEEK WITH BELOW NORMAL STANDARDIZED ANOMALIES WITHIN THE 500MB HEIGHT AND 850MB TEMPERATURE FIELDS. THIS MIGHT LEAD TO THE FIRST SNOW SHOWERS OF THE SEASON OVR THE NW MTNS...WHICH IS NOT UNUSUAL FOR EARLY OCTOBER. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... SOME SHOWERS ACROSS THE NW...PATCHY LIGHT RAIN TO THE SE AND SW. MOST SITES STILL VFR. OVERALL...LESS ON RADAR THAN WHAT I EXPECTED FOR THIS TIME PERIOD. EARLIER DISCUSSION BELOW. A WARM FRONT APPROACHING FROM THE SOUTH WILL SPREAD LOWERING CLOUDS AND SHRA OVER THE AREA TONIGHT. LATE EVENING REGIONAL RADAR LOOP SHOWING SOME -SHRA ALREADY BEGINNING TO OVERSPREAD CENTRAL PA. HOWEVER...DRY AIR AT LOW LVLS SHOULD INITIALLY KEEP CLOUD BASES/VSBYS IN THE VFR CATEGORY THROUGH AT LEAST MIDNIGHT IN MOST SPOTS. UPSTREAM OBS AND MDL DATA SUGGEST A RAPID DETERIORATION IN FLYING CONDS AFTER MIDNIGHT ALONG THE SPINE OF THE APPALACHIANS...WHERE MOISTENING SERLY FLOW ASCENDS THE HIGHER TERRAIN. CIGS IN THIS AREA...INCLUDING JST...AOO...UNV AND BFD...WILL LIKELY DROP TO IFR BTWN 07Z-10Z. THE LOWER ELEVATION AIRFIELDS FURTHER EAST... INCLUDING IPT/MDT/LNS...MAY ONLY FALL TO MVFR LATE TONIGHT. LITTLE IMPROVEMENT EXPECTED TUE...AS THE AREA WILL REMAIN IN MOIST...SERLY FLOW NORTH OF WARM FRONT. OCNL -RA/DZ MAY TAPER OFF BY AFTN. HOWEVER...MDL DATA CONTINUES TO INDICATE A LIKELIHOOD OF IFR CIGS PERSISTING ALONG THE EAST SLOPES OF THE APPALACHIANS... INCLUDING BFD/UNV/AOO/JST. OUTLOOK... WED...AM LOW CIGS/FOG POSSIBLE. THU...AM LOW CIGS/FOG POSSIBLE EAST. FRI-SAT...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...DANGELO/STEINBUGL AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
241 AM MDT THU OCT 4 2012 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 240 AM MDT THU OCT 4 2012 LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS PROGRESSIVE PATTERN IN PLACE ACROSS THE CONUS...WITH REX BLOCK STILL IN PLACE OVER THE PACIFIC. THE NEAREST FEATURE IS A NEGATIVELY TILTED SHORTWAVE TROUGH OVER THE DAKOTAS...WITH W/NW FLOW IN PLACE OVER THE CWA. AT THE SURFACE THE STRONG COLD FRONT PASSED THROUGH THE CWA BEFORE MIDNIGHT AND IS NOW EXTENDING FROM THE OKLAHOMA PANHANDLE ACROSS CENTRAL KANSAS TOWARDS CENTRAL MINNESOTA. TEMPERATURES ALREADY DROPPING INTO THE MID 30S ACROSS THE WEST DESPITE WINDS AROUND 15-25KT AND MID-HIGH CLOUD DECK. THE MAJOR FORECAST FOCUS THROUGH THIS WEEKEND IS ON THE COLD TEMPERATURES SETTLING IN OVER THE PLAINS AND PRECIP CHANCES FRIDAY THROUGH SATURDAY. GUIDANCE IS IN REASONABLY GOOD AGREEMENT FOR TONIGHT THAT TEMPERATURES TONIGHT SHOULD DROP DOWN INTO THE LOW TO MID 30S ACROSS THE AREA. I HAVE QUESTIONS TO HOW COLD IT WILL REALLY GET CONSIDERING THE INCREASING CLOUD COVER AND WINDS AROUND 10KT ACROSS THE WEST. WHILE I CANT RULE OUT FREEZE WARNING CRITERIA BEING MET AT TRADITIONAL COLD SPOTS MY CONFIDENCE IS NOT THERE. I AM HOLDING OFF ON ISSUANCE OF ANY PRODUCTS DUE TO UNCERTAINTIES. MUCH COLDER TEMPERATURES ARE EXPECTED FRIDAY THROUGH SATURDAY NIGHT...WITH DAYTIME HIGHS IN THE 40S. ON SATURDAY LOCATIONS IN THE WEST MAY NOT BE MUCH WARMER THAN THE UPPER 30S FOR HIGHS WITH PRECIPITATION AND LOW CLOUDS POSSIBLY LINGERING INTO THE AFTERNOON. A HARD FREEZE WILL BE POSSIBLE FRIDAY NIGHT...WITH MOST LOCATIONS IN THE LOW 30S. WITH CLEARING SKIES AND LIGHTER WINDS SATURDAY NIGHT A KILLING FREEZE APPEARS LIKELY WITH LOW TEMPERATURES IN THE MID TO UPPER 20S ACROSS THE AREA. A SERIES OF SHORTWAVE TROUGHS WILL ROTATE ALONG THE BASE OF THE LARGE SCALE TROUGH OVER THE CWA FRIDAY THROUGH SATURDAY EVENING. THE BEST CHANCE FOR MEASURABLE PRECIP SHOULD BE LATE FRIDAY NIGHT THROUGH SATURDAY MORNING...COINCIDING WITH A COUPLED 300MB JET STRUCTURE AND UPSLOPE FLOW ACROSS THE WEST. NAM/SREF WOULD ACTUALLY SUPPORT SOME MESOSCALE BANDING ASSOCIATED WITH A H7 TROUGH OVER NE COLORADO...AND ARE PRODUCING HIGHER QPF VALUES AS A RESULT. IM NOT SURE ABOUT THIS SOLUTION...HOWEVER IT IS CERTAINLY POSSIBLE. OVERALL MOST PRECIP SHOULD BE ON THE LIGHT SIDE. PHASE CHANGE WILL BE COMPLICATED...WITH A RAIN/SNOW CHANGE OVER POSSIBLE IN THE MORNING AND OVERNIGHT PERIODS. THE BEST CHANCE FOR ACCUMULATING SNOW REMAINS IN THE WEST...WITH AROUND HALF AN INCH POSSIBLE ON GRASSY SURFACES BY SATURDAY MORNING ALONG AND WEST OF THE CO/KS STATE LINE. THIS COULD BE A LITTLE HIGHER IF THE NAM/SREF SOLUTION WERE TO VERIFY. DUE TO WARM GROUND TEMPERATURES IT STILL LOOKS LIKE SNOW ACCUMULATION SHOULD BE LIMITED TO GRASSY AREAS AND ELEVATED SURFACES. .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 240 AM MDT THU OCT 4 2012 COOL AND DRY WEATHER IS EXPECTED THROUGH THE EXTENDED PERIOD WITH THE CENTRAL PLAINS PRIMARILY DOMINATED BY NORTHWEST FLOW ALOFT. SEVERAL UPPER LEVEL SHORT WAVE TROUGHS ARE FORECAST TO DROP SOUTHEAST ACROSS THE NORTHERN ROCKIES AND NORTHERN PLAINS THROUGH THE PERIOD...BRUSHING THE CENTRAL HIGH PLAINS. THIS WILL KEEP TEMPERATURES ON THE COOL SIDE FOR DAYTIME HIGHS AS SURFACE CANADIAN AIR IS PERIODICALLY REFRESHED AFTER EACH UPPER TROUGH PASSAGE. LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED...AS THE MAIN DYNAMICS/LIFT DURING PERIOD WILL STAY TO THE NORTH. SUNDAY WILL LIKELY BE THE COOLEST DAY IN THIS EXTENDED PERIOD WITH HIGHS IN THE 50S AFTER A POTENTIAL HARD FREEZE THAT MORNING. 850 MB TEMPERATURES STARTING AROUND 0C SUNDAY MORNING ARE FORECAST TO WARM TO AROUND 10C BY MONDAY AND CONTINUE HOVERING IN THE 8-14C RANGE THROUGH MID-WEEK WHICH SHOULD TRANSLATE TO HIGHS GENERALLY IN THE 60S AND LOWS IN THE 30S MONDAY AND 40S FOR TUE/WED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1118 PM MDT WED OCT 3 2012 VFR EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND KMCK. ISOLATED THUNDERSTORM NEAR KMCK WILL MOVE AWAY FROM THE TERMINAL BY 06Z AND WITH COLDER AND MORE STABLE AIR MOVING IN BEHIND THE FRONT NO FURTHER THUNDERSTORM DEVELOPMENT IS ANTICIPATED. NORTH WINDS WILL CONTINUE TO GUST TO 20-30KTS OVERNIGHT THEN GRADUALLY DIMINISH ON THURSDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...DLF AVIATION...024
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
157 AM EDT THU OCT 4 2012 .SYNOPSIS... EXPECT ONE MORE DAY OF SUN AND WARM TEMPERATURES BEFORE A COLD FRONT BRINGS RAIN FRIDAY THROUGH SUNDAY AND SHARPLY COLDER TEMPERATURES. && .NEAR TERM /THROUGH TODAY/... UPPER LOW WILL CONTINUE ITS SLOW PROGRESS EASTWARD OVERNIGHT. WHILE THE ACTUAL COLD FRONT REMAINS EAST OF THE AREA OVER CENTRAL PA...MOISTURE BEING PULLED NORTH WITH THE HELP OF THE LIFTING LOW COULD HELP TO SPAWN A FEW SHOWERS IN THE EASTERN RIDGES TONIGHT. A MORE WESTERLY COMPONENT TO THE WINDS AT LOWER LEVELS SHOULD HELP PROVIDE SOME UPSLOPE IN ADDITION TO THE LIFTING VORT MAX. NO FURTHER EXPANSION OF SHOWERS IS EXPECTED AS THE DRY SLOT FINALLY REACHES OHIO. THIS SHOULD GRADUALLY ERODE THE CLOUD DECK AND PROVIDE FOR SOME RADIATIONAL COOLING. STILL KEPT TEMPERATURES A BIT ELEVATED...ESPECIALLY WESTERN PA/NORTHERN WV...WHERE RESIDENCE TIME UNDER CLOUD DECK SHOULD KEEP THOSE LOCATIONS WARMER. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... MODEL TIMING OF THE APPROACH OF THE COLD FRONT CONTINUES TO REMAIN FAIRLY CONSISTENT BUT TIMING ISSUES IN HOW QUICKLY IT CROSSES THE REGION AND THE DEPTH/STRENGTH OF THE SECONDARY SHORTWAVE HAVE CAUSED SOME INCONSISTENCIES FROM RUN TO RUN. HAVE DECIDED TO PUSH BACK POPS JUST SLIGHTLY WITH THE NEW RUNS OF THE NAM/GFS AND THE 12Z ECMWF AND HAVE ALSO CUT BACK POPS QUICKER FOR THE LATTER HALF OF THE PERIOD THOUGH WILL BRING THEM BACK IN THE WITH CHANCE OF PRECIPITATION WITH THE SECOND WAVE. STILL...WITH THE LATER FRONTAL PASSAGE TIMING...INSTABILITY IS STILL VERY WEAK SO KEPT THUNDER OUT FOR NOW. TEMPERATURES SHOULD CONTINUE TO RUN ABOVE NORMAL THROUGH FRIDAY. STRONG COLD ADVECTION WITH THE PASSAGE OF THE FRONT SHOULD BRING TEMPERATURES TO BELOW NORMAL VALUES SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... CONSENSUS OF RECENT ECENS AND NAEFS MODEL OUTPUT SHOW LINGERING POSTFRONTAL SHOWERS THROUGH DAYTIME SUNDAY...AND PERHAPS INTO SUNDAY NIGHT...DEPENDING ON HOW WELL DEVELOPED A LOW PRESSURE WAVE BECOMES ACROSS VIRGINIA. IF PRECIPITATION LINGERS TOO LONG SUNDAY NIGHT... THE SURFACE LAYER ACROSS THE MOUNTAINS MAY COOL SUFFICIENTLY TO ALLOW A MIX WITH SNOW SHOWERS LATE. EASTBOUND HIGH PRESSURE FROM THE PLAINS WILL THEN PROMOTE DRY CONDITIONS MONDAY INTO WEDNESDAY. CONCUR WITH HPC GUIDANCE REGARDING COOLER THAN NORMAL TEMPERATURES INTO TUESDAY. MONDAY WILL HAVE VALUES NEARLY 10 DEGREES COLDER THAN NORMAL. TEMPERATURES WEDNESDAY MAY REBOUND TO NEAR NORMAL. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... OBS...SATELLITE IMAGES...AND THE LATEST DETERMINISTIC MDL TRENDS INDICATE THE MID LVL CLD BLANKET OVR THE UPR OH VALLEY SHOULD CONT TO FADE AS THE NGT PROGRESSES...LEAVING A THINNING CS CANOPY TO ACCOMPANY THE APPRCH OF A WEAKENING SHRTWV MOVG ACRS THE MIDWEST. THIS TREND WOULD FAVOR AN INCRS IN RADIATIONAL FOG POTENTIAL AS IS EVIDENT IN SOME OF THE MIDNGT OBS ARND THE REGION. HOWEVER...THE EVE UPR AIR PLOT...IN CONJUNCTION WITH NAM AND RAP MDL SNDINGS INDICATE A NEGATIVE HYDROLAPSE AND HIGH CONDENDSATION PRES DEFICITS IN THE BNDRY LYR. HENCE...IFR FOG WL NOT BE FORECAST...ALTHOUGH MVFR WL BE MENTIONED AT PORTS NEAREST THE WATER SOURCES AS PER AFOREMENTIONED OB-TRENDS...CROSSOVER TEMPS...AND THE NAM SFC COND PRES PROGNOSIS. AT ANY RATE...GENL VFR WL QUICKLY DOMINATE AFTR DAYBREAK...BUT THE MIDWRN SHRTWV WL TIGHTEN THE PRES GRADIENT AND INCRS WIND SPEED OVR THE UPR OHIO VALLEY WITH ITS DRY PASSAGE. LOOK FOR GUSTS IN THE 15 TO 20 KT RANGE DURING THE AFTN. .OUTLOOK.../TONIGHT THROUGH MONDAY/... THE NXT CHC FOR WIDESPREAD RESTRICITION IS EXPECTED WITH A FRIDAY NGT/EARLY SATURDAY CDFNT. WIDESPREAD RESTRICTIONS IS STRATOCU AND SHRA ARE ANTICIPATED FOR THE WEEKEND AS MUCH COLDER AIR ADVECTS ACRS TH GREAT LAKES AND OVR THE UPR OH VALLEY REGION. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
400 AM CDT THU OCT 4 2012 .DISCUSSION... Short Term (Today through Saturday Night)... 08Z surface analysis shows well defined cold front has pushed into far NW MO. Earlier surface based convection has long since dissipated, with pockets of post frontal elevated convection having a better go at it between Omaha to north central KS. RAP soundings show that modest elevated instability (100-300 J/Kg CAPE) will overspread NE KS and NW MO toward daybreak, supporting scattered showers and perhaps a few thunderstorms. Today: Precipitation won`t be the only issue to contend with as the temperature forecast will be equally, if not more challenging. High resolution models show that the frontal speed and cold advection will slow with time due to a combination of daytime mixing and a shift of post frontal precipitation toward the northeast. Southerly winds and weak moisture advection were providing a mild start across the warm sector, and so it seems likely that temperatures will quickly rebound to near yesterday`s maxes, with mid to upper 70s likely over mid Missouri under abundant sunshine. Across the front in far northwest Missouri, strong cold advection and cloud cover suggest that effective highs may be reached at 12Z with only a modest afternoon recovery in the wake of morning convection. It`s possible that my 60F highs here may be perhaps generous. In between these extrema, the forecast is even more nebulous as highs could be reached mid-late morning with temps steady or slowly falling in the afternoon depending on the offset between cold advection and daytime heating. With respect to POPs, the orientation of the frontal axis and elevated instability axis is reflected in keeping scattered shra/-tsra mainly north of a Kansas City to Kirksville axis for today. Converage will be limited by weakening ascent and ambient dry mid level air, so 30-40 POPs look kosher. Tonight: The surface front should eventually fizzle just southeast of the CWA this evening as large scale height falls finally arrive from the northwest. The arrival of stronger mid level flow will help sharpen a deep layer thermal gradient, with model cross sections showing a classic strengthening of layered/tilted frontogenesis beneath the mid-upper jet cores. Condensation pressure deficits indicate a fairly rapid top-down saturation this evening along and south of a Kansas City-Kirksville line, with some convective instability present as well. Thus, expect a blossoming of an axis of showers embedded thunder between 00 and 06Z over the srn half of the CWA, or perhaps a resurgence of whatever lingers from the daytime hours. Have increased POPs to around 60 percent for areas south of the MO river and brought POPs back toward the northwest overnight. Temperatures will steadily fall via strong cold advection and evaporative cooling, leading to some very raw conditions where precipitation is ongoing. Friday: This process should continue through the daytime Friday with bands of mainly light rain persisting ahead of the large upper trough axis still to the north and west. Surface pressure rises will continue under moderate cold advection, leading to some pretty miserable conditions as temperatures struggle to break the 50 degree mark. Friday Night-Saturday: Layered frontogenesis should slowly shift south and east, allowing precipitation to gradually end from the northwest. Extensive cloudiness and perhaps even some drizzle will linger as the deepening longwave trough still remains well northwest of the area. Mid-high level RH values confirm this idea, and again temperatures will run some 20+ degrees below normal. Saturday Night: With the passage of the upper trough, skies should clear, coincident with the arrival of the surface ridge axis. Temperatures will likely plummet after midnight, with near certainty that the coldest night of the early autumn season is upon us. Widespread frost looks almost a given and some sheltered areas across NW Missouri could dip below freezing for an hour or two. Bookbinder Medium Range (Sunday through Wednesday)... Cool temperatures will still be prevailing as the end of the weekend arrives, though some moderation is in store for the work week. A pronounced trough will still be in control of the weather across the Plains, pushing a cold Canadian surface high through the Lower Missouri River Valley. The consensus amongst the medium range models is for the trough pushing this cold air to continue dominating the weather across the eastern half of the nation through the work week. However, with a series of shortwaves expected to drop into, and then move through this broader longwave feature, it wont be all cold air advection for next week. For Sunday, the center of the cold Canadian surface high will be sliding off to our east, allowing the first hints at a return flow to develop by late in the day. The return flow that will be in place by Monday should allow afternoon readings to jump back into the 60s, with that temperature range expected to persist through at least the middle of the work week. This temperature regime will also support overnight lows in the 40s, so any weekend frost issues are not expected to persist into the work week at this time. Otherwise, have continued to carry some silent slight chance POPs from Tuesday into Tuesday night. Several models advertise a shortwave rotating through the broader trough in that time period. Warm air advection on the back side of the exiting surface high, ahead of another weak frontal boundary, could squeeze some drops from the air. But, given the many questions on timing and moisture availability have opted to leave the POPs in the silent slight chance range. Otherwise, consensus model output inserted more POPs for Wednesday. These did not look reasonable given the surface high expected to be shifting through the Plains States during that period, so have yanked them out. Cutter && .AVIATION... For the 06Z TAFs, Nebraska cold front continues southeast push and will pass through the terminals Thursday morning with increasing NW winds. Expect gusty winds within 1-2 hours of frontal passage. 00z NAM model guidance is slower in saturating the mid levels via isentropic ascent and layered frontogenesis and thus slower in developing post frontal rain, so have pushed back start of rain threat by 3-6 hours. Rain chances also appear to be increasing by very late afternoon and especially into Thursday evening due to top-down saturation. So, have introduced a TEMPO group into the KMCI/KMKC terminals. MJ && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
451 AM CDT THU OCT 4 2012 .SHORT TERM...THROUGH SATURDAY NIGHT. ALTHOUGH CHANCES OF LEGITIMATE...WIDESPREAD MEASURABLE PRECIPITATION WITHIN THE CWA DURING THE NEXT 72 HOURS ARE GENERALLY QUITE LOW...THE FORECAST PRESENTS PLENTY OF CHALLENGES PRIMARILY IN THE OVERNIGHT LOW TEMPERATURE DEPARTMENT...WITH THE ULTIMATE QUESTION EACH OF THE NEXT 3 NIGHTS BEING JUST HOW COLD WILL IT ACTUALLY GET...AS IT COULD BE A DICEY BATTLE BETWEEN A VERY COOL AIRMASS AND CLOUD COVER TRYING TO HOLD SOME AREAS UP A BIT. FOR NOW HAVE HELD OFF ON ANY FROST/FREEZE HEADLINES...BUT WILL CONTINUE TO HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK. STARTING OFF RIGHT AWAY THIS MORNING...AS I TYPE A SOMEWHAT SURPRISINGLY STRONG THUNDERSTORM WITH CONFIRMED PENNY/NICKLE HAIL IS QUICKLY SLIDING EAST ACROSS JEWELL COUNTY KS...AND SHOULD BE EXITING THE CWA WITHIN THE NEXT HOUR. EARLIER IN THE NIGHT...A FEW OTHER STRONG STORMS LIKELY WITH SMALL HAIL ALSO AFFECTED NEB ZONES INCLUDING BOTH THE FRANKLIN/MERRICK COUNTY AREAS. OTHERWISE...THE VAST MAJORITY OF THE CWA IS DRY AT THIS HOUR...WITH STEADY NORTHWEST WINDS OF 15-20 MPH AND HIGHER GUSTS SERVING AS THE MAIN PRE-DAWN ISSUE...ALTHOUGH THE SPORADIC ADVISORY LEVEL SUSTAINED SPEEDS OF 30+ MPH THAT WERE BEING REPORTED A FEW HOURS AGO HAVE LARGELY TAMED DOWN A BIT. 08Z OBJECTIVE SURFACE ANALYSIS PUTS THE LEADING EDGE OF THIS FIRST TRULY STRONG COLD FRONT OF THE FALL SEASON ALONG A LINE FROM SOUTH CENTRAL KS TO WESTERN IA...HAVING PASSED THROUGH THE ENTIRE CWA. THIS FRONT IS TRAILING FROM A 1005MB LOW OVER CENTRAL MN...WITH GUSTY NORTHWEST WINDS BEING POWERED BY CONTINUED MODEST PRESSURE RISES WELL TO THE SOUTHEAST OF AN EXPANSIVE 1036MB HIGH CENTERED OVER THE MT AREA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRMS STRENGTHENING ZONAL FLOW ACROSS THE CENTRAL PLAINS...ALONG THE SOUTHERN PERIPHERY OF A STRONG MID LEVEL VORT MAX SWINGING EAST ACROSS THE DAKOTAS INTO MN. FOR THE FIRST FEW HOURS THROUGH SUNRISE THIS MORNING...HAVE LINGERED A SCATTERED THUNDERSTORM MENTION ACROSS SEVERAL FAR EASTERN/SOUTHEAST COUNTIES TO ACCOUNT FOR ONGOING ACTIVITY. THESE SHOWERS/STORMS ARE GENERALLY TIED TO A STRONG ZONE OF FRONTOGENESIS IN THE 850-700MB LAYER...AND ACCORDING TO 08Z MESOSCALE ANALYSIS ARE TAKING FULL ADVANTAGE OF ONLY AROUND 500 J/KG OF ELEVATED CAPE...BUT WITH INCREASING DEEP-LAYER 0-6KM SHEAR NOW UP INTO THE 30-40KT RANGE. WOULD EXPECT A CONTINUED THREAT OF HAIL UP TO THE PENNY-ISH SIZE RANGE AS LONG AS THIS CONVECTION CONTINUES TO LINGER IN SOUTHEAST ZONES EARLY THIS MORNING. GETTING INTO THE OFFICIAL DAYTIME 12Z-00Z PERIOD...AT LEAST FOR NOW CONTINUED TO LINGER A SCATTERED SHOWER/STORM MENTION IN A HANDFUL OF FAR SOUTHEAST COUNTIES THROUGH 15Z...BUT ACCORDING TO REFLECTIVITY TRENDS FROM THE 06Z HRRR THIS IS PROBABLY BEING PLENTY GENEROUS...AS MOST CONVECTION SHOULD FINALLY BE OUT OF THE CWA BY SUNRISE OR SO. ONCE THIS ONGOING PESKY STRONG CONVECTION GETS OUT OF HERE...THE MAJORITY OF THE DAY SHOULD BE FAIRLY UNEVENTFUL AND DRY WITHIN THE CWA...WITH SKIES FOR MOST OF THE DAY AVERAGING NO WORSE THAN PARTLY CLOUDY IF NOT MOSTLY SUNNY. IT GOES WITHOUT SAYING THAT THOSE NOT PAYING ATTENTION THE LAST FEW DAYS WILL BE CAUGHT OFF GUARD BY THE 25-30 DEGREE DROP IN TEMPS FROM YESTERDAY. KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...BUT BASED ON EXPECTATION OF SOME SUN AND DECENT MIXING...ACTUALLY NUDGED UP MOST AREAS 1-2 DEGREES...BUT STILL KEEPING NEARLY ALL AREAS A FEW DEGREES EITHER SIDE OF 60. ALTHOUGH WINDS WILL REMAIN QUITE BREEZY THIS MORNING WITH GUSTS OF AT LEAST 25-30 MPH STILL COMMON...A STEADY DECREASING TREND WILL CONTINUE THROUGH THE DAY WITH SUSTAINED SPEEDS THIS AFTERNOON AVERAGING AROUND 15 MPH OR LOWER. TONIGHT...NORTH-NORTHEAST BREEZES OF NO MORE THAN 5-10 MPH WILL PREVAIL CWA-WIDE AS SURFACE HIGH PRESSURE SETTLES DEEPER INTO THE REGION. HOWEVER...CLOUD TRENDS WILL PROVE TRICKY...AS THE REGION COMES UNDER INCREASING UPPER LEVEL JET ENTRANCE REGION DYNAMICS AS A BROAD TROUGH CONTINUES SETTLING INTO THE CENTRAL/NORTHERN PLAINS. ALTHOUGH THE FORECAST FOR TONIGHT WAS LEFT VOID OF PRECIP MENTION...ISENTROPIC LIFT EVIDENT AROUND THE 700MB LEVEL SHOULD PROMOTE A STEADILY EXTENDING BAND OF MID LEVEL CLOUDS ACROSS MOST OF THE CWA ESPECIALLY AFTER MIDNIGHT...WITH THE BEST POTENTIAL FOR PRECIP REMAINING WEST OF THE CWA. HOWEVER...CERTAINLY CANNOT RULE OUT A FEW SPRINKLES LATE TONIGHT ESPECIALLY IN SOUTHERN ZONES BUT WILL KEEP EVEN THIS MENTION OUT FOR NOW. ALTHOUGH MET/MAV GUIDANCE CAME IN QUITE CHILLY FOR TONIGHTS LOWS...OPTED TO KEEP THE OFFICIAL FORECAST AT LEAST 3 DEGREES ABOVE THIS GUIDANCE CONSENSUS IN MOST AREAS TO ACCOUNT FOR EXPECTATION OF INCREASING CLOUDS THROUGH THE NIGHT. THIS YIELDED A SLIGHTLY WARMER LOW TEMP FORECAST THAN PREVIOUS...BUT STILL BRINGS MOST NEB ZONES INTO THE LOW-MID 30S...BUT RANGING FROM UPPER 20S FAR NORTH TO UPPER 30S IN MOST KS ZONES. ALTHOUGH A MARGINAL FREEZE AND/OR PATCHY FROST IS VERY POSSIBLE TONIGHT ACROSS MOST NEB ZONES...THE UNCERTAINTY IN HOW MUCH CLOUD COVER COULD HOLD THINGS UP...ALONG WITH THE FACT THAT THE NEXT FEW NIGHTS SHOULD BE EVEN COLDER...HAS KEPT ME FROM ISSUING A FORMAL FROST/FREEZE HEADLINE FOR TONIGHT AT THIS TIME. FRIDAY DAYTIME...SUBTLE SHORTWAVE ENERGY CONTINUES TO TRACK WEST- EAST ACROSS THE CWA UNDERNEATH ONE OF THE STRONGER...MOST PERSISTENT UPPER LEVEL JETS SEEN IN AWHILE. PERSISTENT MID LEVEL LIFT UNDERNEATH THIS JET CORE SHOULD KEEP PLENTY OF MID-HIGH CLOUDS AROUND DURING THE DAY. AS FOR RAIN CHANCES...CONVERTED ZONE FORECAST WORDING TO SLIGHT CHANCE OF LIGHT RAIN ACROSS MOST OF THE CWA...WITH THE OVERALL BEST RISK FOR POSSIBLY A FEW HUNDREDTHS TARGETING THE SOUTHWEST 1/2 OF THE AREA. IF THE LOW LEVEL THERMAL PROFILE SETS UP JUST RIGHT...SUPPOSE A FEW SNOWFLAKES ARE POSSIBLE DURING THE MORNING IN THE WEST AROUND THE DAWSON COUNTY AREA...BUT WITH LIGHT RAIN MORE LIKELY TO DOMINATE HAVE LEFT THIS AS THE ONLY PRECIP TYPE MENTION FOR NOW. FOR HIGH TEMPS NUDGED UP EASTERN ZONES VERY SLIGHTLY BUT OTHERWISE LITTLE CHANGE WITH HIGHS IN MOST AREAS ONLY LOW-MID 50S BUT MAYBE ONLY UPPER 40S IN PARTS OF THE WEST. FRIDAY NIGHT...A MID LEVEL SHORTWAVE OVER THE DAKOTAS WILL SINK SOUTH TOWARD THE REGION...AS FAST ZONAL FLOW CONTINUES IN THE UPPER LEVELS. LINGERED A SLIGHT CHANCE OF LIGHT RAIN IN FAR SOUTHERN/SOUTHWEST ZONES THROUGH THE NIGHT...BUT THE LATEST TRENDS HAVE BEEN FOR THE VAST MAJORITY OF THE CWA TO STAY DRY THROUGH THE NIGHT WITH THE MAIN FOCUS FOR RAIN OR A RAIN-SNOW MIX HOLDING JUST WEST OF THE CWA. AGAIN...CLOUD TRENDS WILL PROVE VERY TRICKY REGARDING HOW COLD IT GETS...AS EXPECT A GRADIENT RANGING FROM MORE CLEAR IN THE NORTHEAST TO MORE CLOUDY IN THE SOUTHWEST. SOME OF MET/MAV GUIDANCE CAME IN QUITE COLD...AND ALTHOUGH DID NOT GO QUITE AS LOW AS THIS GUIDANCE...DID LOWER LOWS A SOLID 2-5 DEGREE FROM PREVIOUS FORECAST...NOW PUTTING MOST AREAS NORTH OF HIGHWAY 6 DOWN IN THE 20S AND AREAS SOUTH INTO KS MAINLY LOW-MID 30S. AS A RESULT...UNLESS CLOUD WREAK HAVOC...MUCH OF THE NORTHERN 1/2 OF THE CWA SHOULD REALIZE ITS FIRST HARD FREEZE OF THE SEASON...WITH FREEZE HEADLINES A DECENT BET DURING THE NEXT FEW FORECAST CYCLES. SATURDAY DAYTIME...THE AFOREMENTIONED SHORTWAVE TO THE NORTH DROPS SOUTH OVER NEB...BUT WITH ANY APPRECIABLE FORCING FOR LIGHT PRECIP STILL ONLY SKIRTING THE FAR SOUTHWESTERN CWA...WHERE A SLIGHT CHANCE OF LIGHT RAIN WAS MAINTAINED. OTHERWISE...NUDGED UP HIGHS VERY SLIGHTLY MOST AREAS BASED ON LATEST GUIDANCE CONSENSUS...BUT WITH MOST AREAS ONLY LOW-MID 50S AND UPPER 40S SOUTHWEST. FINALLY FOR SATURDAY NIGHT...CONFIDENCE IS FAIRLY HIGH THAT IT WILL BE DRY CWA-WIDE...AND GENERALLY CLEARER THAN BOTH TONIGHT/FRIDAY NIGHT AS THE MAIN MID LEVEL WAVE DEPARTS SOUTHEAST TOWARD MO. FOR THOSE AREAS THAT DO NOT HARD-FREEZE FRIDAY NIGHT...SATURDAY NIGHT IS STILL EXPECTED TO PRETTY MUCH PUT THE NAIL IN THE COFFIN ON THE GROWING SEASON...WITH MOST IF NOT OF THE CWA SETTLING AT LEAST INTO THE MID-UPPER 20S. IF THINGS GO AS CURRENTLY ENVISIONED...FRIDAY NIGHT COULD FEATURE THE LAST FREEZE WARNING OF THE SEASON IN ROUGHLY THE NORTHERN 1/2 OF THE CWA...WITH THE SOUTHERN 1/2 LIKELY BEING FINISHED OFF SATURDAY NIGHT. AS ALREADY STATED SEVERAL TIMES THOUGH...MID LEVEL CLOUD TRENDS COULD POTENTIALLY THROW IN A WRENCH IN THESE PLANS HOWEVER...ESPECIALLY IF THEY HOLD UP LOWS HIGHER THAN EXPECTED FRIDAY NIGHT. .LONG TERM...STARTING 12Z SUNDAY. LONG TERM GUIDANCE SUGGESTS NORTHWESTERLY TO QUASI-ZONAL MID AND UPPER LEVEL FLOW WILL PERSIST OVER THE CENTRAL PLAINS DURING THE LONG TERM FORECAST PERIOD. A PAIR OF MID LEVEL SHORTWAVES ARE ALSO EXPECTED TO PUSH ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY DURING THE LONG TERM FORECAST PERIOD...ONE DURING THE DAY MONDAY AND THE OTHER ON TUESDAY. BEFORE THE PASSAGE OF THESE MID LEVEL SHORTWAVES HOWEVER...SOUTHERLY LOW LEVEL FLOW AND RESULTANT WARM AIR ADVECTION SHOULD PRESENT A WARMING TREND BOTH SUNDAY AND MONDAY. THE INITIAL MID LEVEL SHORTWAVE ON MONDAY IS THEN EXPECTED TO PROMOTE SURFACE CYCLOGENESIS OVER SOUTHERN ONTARIO...WITH AN ASSOCIATED COLD FRONT EXPECTED TO SWEEP SOUTH/SOUTHEAST ACROSS THE CENTRAL PLAINS EARLY TUESDAY. THE SECOND MID LEVEL SHORTWAVE ON TUESDAY IS THEN EXPECTED TO PROVIDE A REINFORCING SHOT OF LOW LEVEL COLD AIR ADVECTION TO THE AREA TUESDAY NIGHT INTO WEDNESDAY MORNING WITH THE OPERATIONAL GFS...EC AND GEFS-MEAN ALL SUGGESTING A ~1025MB SURFACE HIGH WILL SET UP SHOP NEAR OR OVER OUR AREA BY 12Z WEDNESDAY. GIVEN ALL THIS...WENT AHEAD WITH A COOLING TREND IN TEMPERATURES TUESDAY AND WEDNESDAY. DESPITE THE PASSAGE OF THESE LOW LEVEL BAROCLINIC ZONES...OVERALL KINEMATIC FORCING APPEARS WEAK THROUGHOUT THE LONG TERM FORECAST. IN ADDITION...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE CWA PER THE OPERATIONAL GFS AND EC SUGGEST TROPOSPHERIC MOISTURE WILL BE FAIRLY LACKING DURING THIS SAME TIME PERIOD. GIVEN ALL THIS...THE LONG TERM FORECAST PERIOD REMAINS DRY. && .PREV DISCUSSION... /ISSUED 1225 AM CDT THU OCT 4 2012/ AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS. MID AND HIGH LEVEL CLOUDS WILL PERSIST AT THE TERMINAL THROUGH MUCH OF THE TAF PERIOD...BUT NOTHING BELOW 7000FT AGL ARE CURRENTLY EXPECTED. ALTHOUGH WEAK CONVECTIVE ACTIVITY WILL REMAIN POSSIBLE THROUGH 12Z...MUCH OF THE TAF PERIOD WILL REMAIN DRY. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24 HORUS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM/AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
141 AM EDT THU OCT 4 2012 .SYNOPSIS... SHOWERS AND A FEW THUNDERSTORMS CAN BE EXPECTED TODAY AS A SLOW MOVING COLD FRONT PUSHES ACROSS THE AREA. DRIER AIR WILL SPREAD ACROSS THE REGION FRIDAY INTO SATURDAY. A STRONGER COLD FRONT WILL MOVE ACROSS THE EASTERN CAROLINAS SUNDAY...FOLLOWED BY COOL AND DRY CANADIAN HIGH PRESSURE THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 1045 PM WEDNESDAY...LATEST NAM/RUC RUNS INDICATE SMALL BUT WEAK MID LEVEL VORTICIES EJECTING OUT OF THE GULF OF MEXICO OVERNIGHT...AND MOVING NNE WITHIN THE TROPICAL MOISTURE PLUME. THE DYNAMICS ASSOCIATED WITH THESE VORTICIES WILL ENHANCE CONVECTION BOTH AREAL COVERAGE AND STRENGTH. LOOK FOR THE LEADING S/W TROF MOVING NNE TO REMAIN JUST WEST OF THE FA LATE THIS EVENING. THE FOLLOWING IDENTIFIABLE MID-LEVEL S/W TROF TO AFFECT THE FA DURING THE OVERNIGHT...AND INTO THE DAYLIGHT HOURS OF THU MORNING. THE LATEST HRRR REFLECTIVITY OUTPUT INDICATES A SLIGHTLY SLOWER EASTWARD PROGRESSION OF THE PCPN...BUT OVERALL LOOKS LIKE A WET MORNING FOR THE THU COMMUTE FOR THE MAJORITY OF THE ILM CWA. THE FORECAST AREA WILL REMAIN IN THE SOUPY AIRMASS OVERNIGHT... WITH ONLY VERY MINOR TWEAKS NEEDED FOR OVERNIGHT LOWS DUE TO LATEST DEWPOINTS RUNNING HIGHER BY 1-2 DEGREES. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 2 PM WEDNESDAY...THE OVERALL MID/UPPER PATTERN WILL DE- AMPLIFY BEGINNING THURSDAY AS THE TROUGH TO THE WEST LIFTS QUICKLY NORTHEASTWARD. ZONAL FLOW WILL PREVAIL BY FRIDAY...GRADUALLY SHUNTING THE DEEPER MOISTURE PLUME TO THE EAST. TIME HEIGHT CROSS SECTIONS INDICATE MUCH DRIER AIR TAKING ROOT IN THE H85-H4 LAYER FROM LATE THURSDAY THROUGH FRIDAY. THE OLD FRONT WILL ALSO DRIFT OFF THE COAST THURSDAY. AS A RESULT...THE CHANCES OF RAIN WILL BE DECREASING DURING THURSDAY...WITH NO POPS THURSDAY NIGHT THROUGH FRIDAY NIGHT. ALTHOUGH DEWPOINTS WILL DECREASE THROUGH THE SHORT TERM PERIOD...THE MUCH DRIER AIR WILL REMAIN UPSTREAM BEHIND ANOTHER COLD FRONT APPROACHING THE AREA. MAX/MIN TEMPERATURES WILL RANGE ABOVE NORMAL EACH DAY AND NIGHT. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 2 PM WEDNESDAY...A MODERATELY STRONG BUT LARGELY MOISTURE DEPRIVED COLD FRONT WILL APPROACH FROM THE NORTHWEST WHILE DECELERATING. WAA AHEAD OF THIS BOUNDARY IN THE SW FLOW WILL PUSH HIGHS INTO THE MID 80S SAVE FOR ALONG THE IMMEDIATE COAST. THE FRONT PUSHES THROUGH ON SUNDAY. THE BEST CHANCE FOR SOME RAINFALL HOWEVER SETS UP FOLLOWING FROPA AS THE UPPER LEVEL FRONT REMAINS ACROSS THE CAROLINAS AND SERVES AS A SOURCE OF LIFT ATOP THE UNDERCUTTING SURFACE COOL AIRMASS. MOST OF THIS WILL TRANSPIRE SUNDAY NIGHT. WHILE THE UNDERCUTTING CONTINUES INTO MONDAY THE COLUMN SHOULD START TO DRY ABOVE AND RAIN CHANCES SHOULD DECLINE PERHAPS CONSIDERABLY. HIGH PRESSURE WILL BUILD IN FROM POINTS NORTH AND WEST FOR THE REMAINDER OF THE LONG TERM. THE COOL ADVECTION WILL SHUT DOWN BUT SHALLOW MIXING COULD KEEP THE RETURN OF CLIMO TEMPS A RATHER GRADUAL PROCESS. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 06Z...RADAR IMAGERY INDICATES AN AREA OF SHOWERS MOVING NORTHEAST TOWARDS THE INLAND CWA. PERIODS OF SHOWERS ARE POSSIBLE AT THESE TERMINALS THROUGH THE EARLY MORNING HOURS...WITH HEAVIER RAIN POTENTIALLY PRODUCING TEMPO SUB-VFR CONDITIONS. LINGERING SHOWER ACTIVITY IS POSSIBLE DURING THE DAY THURSDAY...BUT CLEARING SHOULD OCCUR INTO THE EARLY EVENING HOURS. WEST WINDS AROUND 10 KNOTS EXPECTED ACROSS THE AREA ON TODAY. EXTENDED OUTLOOK...MAINLY VFR CONDITIONS EXPECTED FRIDAY AND INTO THE WEEKEND AS DRIER AIR AND WEAK HIGH PRESSURE MOVE IN OVER THE CAROLINAS. SLIGHT CHANCE OF RAIN LATE SUNDAY AS A STRONGER COLD FRONT MOVES THROUGH THE AREA. OTHERWISE VFR CONDITIONS SHOULD PREVAIL THROUGH THE FORECAST PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM WEDNESDAY...THE SFC PRESSURE PATTERN AND A CONTINUING RELAXING TREND TO THE SFC PG...WILL RESULT IN A S TO SW WIND AROUND 10 KT OVERNIGHT. THE PASSING OF S/W TROFS ALOFT DURING THE OVERNIGHT HRS WILL LIKELY TEMPORARILY INCREASE SFC SPEEDS TO THE 10 TO 15 KT RANGE. SIGNIFICANT SEAS WILL BE IN A CONTINUING SUBSIDING TREND...WITH 2 TO 4 FT COVERING IT...VIA LATEST SWAN RUNS. INITIALLY...WIND DRIVEN WAVES AT 5 TO 7 SECOND PERIODS WILL DOMINATE THE SPECTRUM. HOWEVER...THE 1 TO 2 FOOT 10 TO 12 SECOND PERIOD EASTERLY GROUND SWELL WILL BECOME MORE NOTICEABLE. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 2 PM WEDNESDAY...LIGHT OFFSHORE FLOW THURSDAY WILL VEER TO A NORTHERLY DIRECTION EARLY FRIDAY MORNING AS A WEAK FRONT DRIFTS OFFSHORE. LIGHT AND VARIABLE WIND WILL PREVAIL DURING FRIDAY WITH A VERY WEAK PRESSURE GRADIENT IN PLACE. LIGHT AND VARIABLE CONDITIONS WILL PERSIST THROUGH FRIDAY NIGHT. SEAS WILL HIGHEST THURSDAY MORNING AROUND 3 FT AWAY FROM THE COAST...THEN SUBSIDE TO 1-2 FT THURSDAY NIGHT THROUGH FRIDAY NIGHT. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 2 PM WEDNESDAY...ALTHOUGH A FAIRLY STRONG COLD FRONT WILL BE BEARING DOWN ON THE REGION ON FRIDAY THE PRE FRONTAL FLOW REGIME WILL REMAIN QUITE LAZY THROUGH MOST OF THE DAY. THE BOUNDARY WILL BE DECELERATING AND WEAK HIGH PRESSURE WILL TRY TO HANG ON UNTIL THE LAST MINUTE. A SOUTHERLY WIND DIRECTION WILL BECOME PREDOMINANT AS THE DAY WEARS ON FROM THE FAIRLY VARIABLE WIND OFFERED BY THE EARLIER PARTS OF THE DAY. THE PRE FRONTAL SOUTHWESTERLY FLOW BY SUNDAY WILL INCREASE A FEW KNOTS AS THE BOUNDARY DRAWS EVEN CLOSER AND THEN A FAIRLY SHARP VEER WILL SPREAD GRADUALLY SOUTH ACROSS THE FORECAST ZONES SUNDAY AFTERNOON WITH A TURN TO THE NORTH. WIND REMAINS NORTH TO NORTHEASTERLY ON MONDAY AS THE HIGH BUILDS IN FROM THE NORTH. SUNDAY NIGHT INTO MONDAY SHOULD FEATURE THE ONLY MENTIONABLE BUILDING OF WAVE HEIGHTS AS THE GRADIENT TIGHTENS SLIGHTLY. AT THIS TIME IT APPEARS TO BE A 1 TO 2 FT INCREASE FROM THE RELATIVELY QUIET EARLY PART OF THE LONG TERM FORECAST PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH/8 SHORT TERM...SRP LONG TERM...MBB AVIATION...MRR/BJR/8
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
411 AM CDT THU OCT 4 2012 .DISCUSSION... A COLD FRONT CURRENTLY IN THE TEXAS PANHANDLE WILL QUICKLY MOVE SOUTH THIS MORNING PUSHING THROUGH SOUTHEASTERN NEW MEXICO AND THE PERMIAN BASIN AROUND SUNRISE. OBSERVATIONS SHOWS NORTHERLY WINDS GUSTING IN EXCESS OF 40KTS JUST BEHIND THE FRONT IN THE NORTHWESTERN TEXAS PANHANDLE WHERE SURFACE PRESSURE RISES ARE GREATEST. THE RUC SHOWS THIS AREA OF STRONGER WINDS MOVING SOUTHEAST INTO THE NORTHEASTERN PERMIAN BASIN LATER THIS MORNING AS MAX PRESSURE RISES MOVE ALONG THE SUBSIDENT REGION OF A MID LEVEL SHORTWAVE ASSOCIATED WITH THE FRONT. WINDS MAY BRIEFLY REACH ADVISORY CRITERIA IN OUR CWA THIS MORNING...BUT IT APPEARS TOO BRIEF AND MARGINAL TO ISSUE AN ADVISORY AT THIS TIME THOUGH WINDS WILL BE CLOSELY MONITORED. THE FRONT WILL BRING COOLER TEMPERATURES TODAY WITH ANOTHER REBOUND EXPECTED TOMORROW. THERE IS SOME MODEL DISAGREEMENT ON HOW WARM TEMPERATURES WILL GET TOMORROW WITH THE MET IN GENERAL SEVERAL DEGREES WARMER. WENT CLOSER TO THE COOLER MAV GIVEN THE STRONG PUSH BEHIND THE FRONT AND WEAK SOUTHWEST WINDS TOMORROW NOT PROVIDING MUCH DOWNSLOPING EFFECT. A SECOND STRONG COLD FRONT IS STILL EXPECTED EARLY SATURDAY THOUGH MODELS HAVE INCREASED ITS SPEED WITH AN ARRIVAL POSSIBLY AS EARLY AS MIDNIGHT. THE 24 HOUR HIGH TEMPERATURE FOR MANY LOCATIONS... ESPECIALLY IN THE NORTHERN CWA...WILL BE NEAR MIDNIGHT WITH A COOLING TREND DURING THE DAY. THUS DAYTIME HIGHS ARE HARDLY ANY WARMER THAN MORNING LOWS ON SATURDAY AT FORECAST POINTS EAST OF THE PECOS RIVER. LOCATIONS SOUTH AND WEST SHOULD GET A BETTER CHANCE TO WARM UP WITH THE LATER ONSET OF COLD AIR ADVECTION AND CLOUD COVER. UPPER DYNAMICS ARE NOT GREAT FOR PRECIPITATION THOUGH LIFT ALONG THE ELEVATED FRONTAL ZONE AND A COOL AND MOIST BOUNDARY LAYER COULD PROVIDE FOR POST FRONTAL LIGHT RAIN OR DRIZZLE. ANY ACCUMULATIONS WOULD BE SLIGHT AND THUS POPS ARE LOW. CLOUDS WILL HANG AROUND SUNDAY PROVIDING ANOTHER COOL DAY BEFORE WEAK RIDGING FINALLY ALLOWS FOR A WARMING TREND EARLY NEXT WEEK. THERE CONTINUES TO BE GOOD CONSENSUS WITH AN UPPER LOW SLOWLY MOVING INTO CALIFORNIA AND THE DESERT SOUTHWEST FROM THE EASTERN PACIFIC BY LATE NEXT WEEK. UPPER LEVEL FLOW WILL BACK FROM THE SOUTHWEST AND SURFACE PRESSURE FALLS WILL INCREASE LOW LEVEL SOUTHEASTERLY FLOW. THIS WILL INCREASE MOISTURE AND INSTABILITY POSSIBLY BRINGING OUR NEXT CHANCE FOR DECENT RAINFALL. DESPITE GOOD MODEL CONSENSUS ON THE TIMING AND LOCATION OF THE LOW... MODELS HAVE HAD DIFFICULTY IN THE PAST TIMING SUCH FEATURES AND CONFIDENCE REMAINS TOO LOW TO INTRODUCE POPS AT THIS TIME. SHOULD THE LOW WEAKEN AND EJECT NORTHEAST ACROSS THE FOUR CORNERS AND INTO THE CENTRAL PLAINS...OUR CWA WOULD BE LEFT ON THE DRY SIDE. HENNIG && .PRELIMINARY POINT TEMPS/POPS... ANDREWS TX 76 49 85 49 / 0 0 0 10 BIG SPRING TX 78 50 84 50 / 0 0 0 20 CARLSBAD NM 80 52 92 56 / 0 0 0 10 DRYDEN TX 92 57 93 62 / 0 0 0 0 FORT STOCKTON TX 83 54 93 57 / 0 0 0 10 GUADALUPE PASS TX 77 51 80 51 / 0 0 0 0 HOBBS NM 75 48 85 49 / 0 0 0 10 MARFA TX 84 50 85 55 / 0 0 0 0 MIDLAND INTL AIRPORT TX 78 51 86 51 / 0 0 0 10 ODESSA TX 78 52 87 51 / 0 0 0 10 WINK TX 81 53 92 56 / 0 0 0 10 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 80/10
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
300 AM CDT THU OCT 4 2012 .SHORT TERM...TODAY THROUGH SATURDAY 300 AM CDT THU OCT 4 2012 MAIN FORECAST CHALLENGE WILL BE A STRONG COLD FRONTAL PASSAGE TODAY ALONG WITH SHOWER/ISOLATED THUNDER CHANCES...THEN GUSTY POST FRONTAL WINDS. CONCERNS BEYOND THIS INCLUDE WELL BELOW NORMAL TEMPERATURES INTO THE WEEKEND WITH A HARD FREEZE EXPECTED SATURDAY NIGHT/SUNDAY MORNING. LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS A POTENT/DEEPENING TROUGH MOVING EAST ACROSS THE DAKOTAS WITH A 90-95KT 300MB JET ENTERING THE BASE OF THE TROUGH OVER SD. AT THE SURFACE...DEEP OCCLUDING LOW WAS LOCATED OVER WEST CENTRAL MN WITH A COLD FRONT EXTENDING SOUTHWARD INTO WESTERN IA. RADAR MOSAIC/SURFACE OBSERVATIONS SHOWING ELEVATED SHOWER/ISOLATED THUNDER ACTIVITY ACROSS EASTERN NEB WITH EXPANSIVE DEFORMATION RAIN/SNOW ACROSS THE EASTERN DAKOTAS/NORTHWEST MN. OTHERWISE...ACROSS THE LOCAL FORECAST AREA...IR IMAGERY SHOWING A FEW MID/HIGH CLOUDS. 04.00Z MODELS SHOWING GOOD AGREEMENT THROUGH THE SHORT TERM. FOR TODAY...AS THE LOW CONTINUES TO DEEPEN AND MOVE NORTH TO ALONG THE MN/CANADIAN BORDER THIS MORNING...EXPECTING THE COLD FRONTAL PASSAGE ALONG THE MISSISSIPPI RIVER BY 15Z AND THEN EXITING EAST OF THE AREA AROUND NOON. NAM AND HRRR WRF SHOWING SCATTERED PRECIPITATION ALONG A POST FRONTAL TROUGH MOVING INTO THE AREA THIS MORNING...MAINLY ACROSS NORTHEAST IOWA INTO SOUTHERN WI. NAM DEPICTING 200-400J/KG 1-7KM MUCAPE...SO KEPT MENTION OF ISOLATED THUNDER IN AS WELL. APPEARS RAIN CHANCES MAINLY CONFINED TO THIS MORNING THEN PUSHING EAST AFTER NOON. OTHERWISE...BIGGER STORY WILL BE GUSTY WEST WINDS OVERTAKING THE AREA BEHIND THE COLD FRONT AS DRY SLOT/COLD AIR ADVECTION NOSES IN. SUSTAINED WINDS EXPECTED TO BE IN THE 15-20 MPH RANGE WITH GUSTS HITTING AROUND 30-35 MPH. LOOK FOR HIGHS IN THE 50S TO MIDDLE 60S...SOME 15-20 DEGREES COOLER THAN HIGHS ON WEDNESDAY. FOR TONIGHT...THE DRY SLOT WILL KEEP SKIES MOSTLY CLEAR OVERNIGHT AS THE LOW BEGINS TO FILL AS IT MOVES NORTHEAST INTO ONTARIO CANADA. A FAIRLY TIGHT PRESSURE GRADIENT IS EXPECTED TO KEEP WINDS UP OVERNIGHT IN THE 15 TO 25 MPH RANGE. COLD AIR ADVECTION WILL CONTINUE AS 925MB TEMPERATURES FALL INTO NEGATIVE TERRITORY //ZERO TO MINUS 2C. THIS SHOULD PRODUCE OVERNIGHT RIGHT AROUND THE FREEZING MARK WITH WINDS CHILL IN THE 20-25 DEGREE RANGE THROUGH THE EARLY MORNING HOURS OF FRIDAY. FOR THE REST OF FRIDAY...ANOTHER BLUSTERY COLD DAY WILL BE ON TAP. DESPITE PARTLY TO MOSTLY SUNNY SKIES HIGHS WILL ONLY MAKE IT INTO THE MIDDLE 40S TO LOWER 50S ALONG WITH WEST/NORTHWEST WINDS OF 15-30 MPH. FOR FRIDAY NIGHT INTO SATURDAY...A SECONDARY MID-LEVEL TROUGH WILL DROP SOUTHEAST ACROSS THE AREA FOR A CHANCE OF MIXED RAIN AND SNOW SHOWERS. APPEARS MOST OF THIS ACTIVITY WILL REMAIN NORTHEAST OF I-94 IN BETTER PV-ADVECTION/COLDER AIR ALOFT. TEMPERATURES EXPECTED TO DIP TO AROUND THE 30 DEGREE MARK FRIDAY NIGHT AND ONLY MAKING IT INTO THE 40S ON SATURDAY...WHICH IS MORE TYPICAL FOR MID-NOVEMBER. SATURDAY NIGHT EXPECTED TO SEE A HARD FREEZE AS LOWS TUMBLE INTO THE LOWER AND MIDDLE 20S UNDER MOSTLY CLEAR SKIES AS A SURFACE RIDGE AXIS MOVES OVERHEAD. COULD SEE SOME RECORD LOWS BEING TIED OR BROKEN. FOR EXAMPLE...CURRENT FORECAST LOW FOR LA CROSSE IS 26 AND THIS WOULD TIE THE RECORD SET IN 2001. THIS WILL ALSO LIKELY MARK A FINAL END TO THE GROWING SEASON FOR AREAS THAT HAVE NOT YET SEEN A HARD FREEZE...THIS BEING AREAS ALONG THE MISSISSIPPI/WISCONSIN RIVER VALLEYS. FREEZE HEADLINES MAY EVENTUALLY BE NEEDED TO HIGHLIGHT THIS. .LONG TERM...SUNDAY THROUGH WEDNESDAY 300 AM CDT THU OCT 4 2012 04.00Z GFS/ECMWF IN OVERALL GOOD AGREEMENT WITH SYNOPTIC PATTERN THROUGH THE EXTENDED PERIOD. SUNDAY WILL SEE SOME SLIGHT MODERATION IN TEMPERATURES AS THE RIDGE AXIS SLIPS SOUTH...SETTING UP SOUTHWEST WINDS BACK INTO THE REGION. UNDER MOSTLY SUNNY SKIES...LOOK FOR HIGHS IN THE 40S TO LOWER 50S. MODELS CONSISTENT WITH BRING A LOW FROM ALBERTA CANADA INTO ONTARIO ON MONDAY. INCREASING SOUTHWEST FLOW IN THE WARM SECTOR OF THE LOW EXPECTED TO YIELD HIGHS IN THE MIDDLE 50S TO LOWER 60S. COLD FRONT FROM THIS LOW WILL THEN SWING SOUTHEAST ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY BRINGING WITH IT A CHANCE OF RAIN SHOWERS. WEDNESDAY LOOKS DRY WITH HIGHS IN THE 50S AS HIGH PRESSURE BUILDS OVERHEAD. && .AVIATION...THROUGH 06Z FRIDAY 1152 PM CDT WED OCT 3 2012 A POTENT AREA OF LOW PRESSURE WAS LOCATED OVER SOUTHWEST MINNESOTA THIS EVENING ALONG A COLD FRONT. VFR CONDITIONS PREVAILED AHEAD OF THIS SYSTEM. AS THE LOW PULLS NORTHEAST TONIGHT/THURSDAY THE COLD FRONT WILL SWEEP THROUGH THE TAF SITES. TIMING STILL EXPECTED BETWEEN 12Z-14Z AT KRST AND 15Z-16Z AT KLSE. LOW LEVEL MOISTURE LOOKS TO BE LIMITED AND MODELS HAVE BACKED OFF ON PRECIPITATION COVERAGE AND THUS ONLY INCLUDED VCSH AT BOTH SITES. ALSO...WITH THE LIMITED LOW LEVEL MOISTURE DID BACK OFF ON ANY MVFR CEILINGS OPTING INSTEAD TO JUST WITH A SCATTERED DECK. STRONG COLD ADVECTION BEHIND THE FRONT ALONG WITH STEEP LOW LEVEL LAPSE RATES WILL MIX HIGHER WINDS TO THE SURFACE BY MID MORNING. EXPECT GUSTS TO BETWEEN 25 AND 30 KNOTS AT BOTH SITES BETWEEN 17Z-02Z...WITH THE WINDS DIMINISHING SOMEWHAT AFTER 02Z...ALTHOUGH REMAINING AT OR ABOVE 12 KNOTS. && .ARX WATCHES/WARNINGS/ADVISORIES... 300 AM CDT THU OCT 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
905 AM MDT THU OCT 4 2012 .UPDATE... && .SHORT TERM...TEMPERATURES ACROSS PLAINS CURRENTLY IN THE MIDDLE 30S MOST AREAS. HAVE ENDED FREEZE WARNING. SATELLITE AND OBSERVATIONS STILL SHOWING STRATUS HANGING TOUGH ACROSS ALONG URBAN CORRIDOR AND ADJACENT PLAINS...THOUGH SOME ERRODING ALONG PALMER DIVIDE. MAY NEED TO MAKE SOME ADJUSTMENTS TO CLOUD COVER GRIDS THIS AM. OVERALL...CURRENT FORECAST TRENDS ON TRACK WITH ONLY MINOR ADJUSTMENTS AT THIS TIME. .AVIATION...STRATUS HANGING ON A BIT LONGER THAT PREVIOUSLY THOUGHT...SO WILL CONTINUE THE BKN-OVC AT KDEN AND KAPA THROUGH 17Z. BOTH HRRR AND RUC INDICATING STRATUS SHOULD BE DISSIPATING AT THAT TIME. REST OF TAF TRENDS LOOK ON TRACK. && .PREV DISCUSSION... /ISSUED 416 AM MDT THU OCT 4 2012/ SHORT TERM...COLD FRONT BLASTED THROUGH NORTHEAST COLORADO YESTERDAY AFTERNOON AND EARLY EVENING. MUCH COLDER AIR HAS MOVED OVER NORTHEAST COLORADO WITH TEMPERATURES RUNNING 40 TO 50 DEGREES COOLER THAN 12 HOURS AGO. THE COLD AIR WILL REMAIN OVER NORTHEAST COLORADO TODAY AS A LARGE SURFACE HIGH MOVES OVER THE NORTHERN AND CENTRAL ROCKIES. THIS WILL KEEP TEMPERATURES COOL TODAY WITH EXPECTED HIGHS IN THE LOWER 50S. THE COLD AIRMASS DID NOT MAKE IT OVER THE CONTINENTAL DIVIDE...SO AREAS WEST OF THE DIVIDE WILL SEE A MILD DAY TODAY. THE LOW CLOUDS ALONG THE FRONT RANGE WILL SLOWLY DISSIPATE THIS MORNING. WILL SEE MID AND HIGH CLOUDS TODAY AHEAD OF THE NEXT UPPER LEVEL TROUGH WHICH WILL DROP SOUTH OVER THEN NORTHERN ROCKIES. CLOUDS WILL INCREASE TONIGHT AS THIS TROUGH NEARS THE CENTRAL ROCKIES. LOW WILL BE CHILLY TONIGHT...BUT ARE EXPECTED TO REMAIN JUST ABOVE FREEZING DUE TO THE CLOUDS OVERHEAD. ONLY A SLIGHT CHANCE FOR A FEW WEAK RAIN OR SNOW SHOWERS THIS AFTERNOON AND EVENING OVER THE HIGHER TERRAIN SOUTH OF INTERSTATE 70. LONG TERM...UPSLOPE FLOW PERSISTS ON THE PLAINS FRIDAY EVEN AS THE FLOW ALOFT BECOMES ZONAL ON THE UNDER SIDE OF A SOUTHWARD DIGGING UPPER TROUGH. THIS EASTERLY LOW-LEVEL FLOW SHOULD KEEP TEMPERATURES UNSEASONABLY COOL THROUGHOUT THE DAY WITH 850 MB TEMPERATURES RANGING FROM AROUND 6C ALONG THE BASE OF THE FOOTHILLS TO NEAR 0C IN THE DEEPER COLD AIR OUT NEAR THE NORTHEAST CORNER OF THE STATE. MODELS SHOW THE LEFT EXIT QUAD OF A 110KT JET PASSING OVER NERN COLORADO LATE IN THE DAY WHICH PROVIDED ADDITIONAL LIFT FOR THE PRODUCTION OF SHOWERY PRECIP ACROSS THE NORTHEAST CORNER OF THE STATE. THIS GENERALLY LIGHT PRECIP WOULD EITHER BE SNOW OR A MIX OF RAIN AND SNOW WITH SUB-CLOUD TEMPERATURES JUST ABOVE FREEZING. CLOSER TO THE FRONT RANGE... PRECIP ON FRIDAY WILL MOST LIKELY BE VERY LIGHT AND SPOTTY IN COVERAGE WITH WEAK SUBSIDENCE ALOFT. FRIDAY NIGHT..PRECIP CHANCES ARE EXPECTED TO INCREASE EAST OF THE MTNS AND ESPECIALLY OUT ACRS THE NORTHEAST CORNER OF THE STATE WITH INCREASING QG ASCENT IN ON THE BACK SIDE OF THE PASSING JET. HAVE INTRODUCED A WIDE SWATH OF 50 PCT POPS ACROSS WELD...MORGAN...LOGAN...PHILLIPS AND LINCOLN COUNTIES WHERE WE HAVE A POTENTIAL FOR LIGHT SNOW ACCUMULATION BY MORNING. WE/RE TALKING ABOUT AN INCH OR TWO OF SNOW ON GRASSY SURFACES. COULD JUST AS EASILY GONE WITH LIKELY POPS OUT THAT WAY...BUT THE TIMING OF THIS PRECIP STILL REMAINS IN DOUBT. ON SATURDAY...SFC TEMPERATURES REMAIN QUITE COOL WITH A REINFORCING SURGE OF COLD AIR OVERNIGHT. 850MB TEMPERATURES PROGGED FOR THE PLAINS ARE BARELY ABOVE 0C DURING THE DAY. WENT AHEAD AND LOWERED HIGH TEMPS BY A FEW DEGS IN AREAS EAST OF THE MTNS. MEANWHILE... AREAS WEST OF THE CONTINENTAL DIVIDE SHOULD FEEL LITTLE IMPACT FROM THIS GREAT PLAINS COLD AIR MASS. POPS ON THE WEST SLOPE NEAR ZERO FOR THE MOST PART. THROUGH THE DAY SHOULD SEE PRECIP SHIFTING SOUTH AND EAST AS THE JET AND ITS ACCOMPANYING LIFT ALSO SHIFTS SOUTHEASTWARD. THE NAM IS INDICATING LIGHT SNOW ACCUMULATION ACROSS WASHINGTON AND LINCOLN COUNTIES SATURDAY MORNING...POSSIBLY AS MUCH AS A COUPLE INCHES BY MIDDAY. ELSEWHERE THE CHANCE FOR ACCUMULATING SNOWFALL SHOULD QUICKLY DIMINISH AS SOMEWHAT DRIER AIR BEGINS ADVECTING IN FROM WYOMING. SUNDAY AND BEYOND...THE COLD AIR FLUSHES OUT STARTING SUNDAY... WITH TEMPERATURES RETURNING TO NEAR AVERAGE BY MID-WEEK AS A SHORTWAVE UPPER RIDGE BUILDS OVER THE REGION. AVIATION...LOW CLOUDS WITH CEILING HEIGHTS OF 3000 TO 5000 FEET WILL DISSIPATE THIS MORNING. A SURFACE HIGH CENTERED NORTH OF COLORADO WILL KEEP EASTERLY UPSLOPE WINDS OVER THE AREA TODAY. THIS MAY HELP LOW CLOUDS PERSIST ALONG THE FOOTHILLS THROUGH LATE MORNING. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....BAKER AVIATION...D-L
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1015 AM CDT THU OCT 4 2012 .DISCUSSION... ISSUED 1014 AM CDT THU OCT 4 2012 COLD FRONT HAS MADE IT TO ROUGHLY THE ILLINOIS/IOWA BORDER BY 10 AM...WITH TEMPERATURES QUICKLY DROPPING OFF BEHIND IT. LATEST HRRR GUIDANCE PLACES IT NEAR THE ILLINOIS RIVER BY NOON AND APPROACHING THE I-57 CORRIDOR BY LATE AFTERNOON...ALTHOUGH THE NAM AND RAP MODELS ARE A BIT SLOWER WITH IT NEAR I-55 INSTEAD. ALL THE SHOWERS HAVE BEEN POST-FRONTAL SO FAR...AND EXTENDED FROM EASTERN IOWA TO NORTHERN MISSOURI. EARLIER FORECAST FOR INCREASING POPS ALONG AND NORTHWEST OF THE ILLINOIS RIVER THIS AFTERNOON STILL LOOKS GOOD. COLD AIR ADVECTION BEHIND THE FRONT WILL RESULT IN FALLING TEMPERATURES THIS AFTERNOON WEST OF THE I-55 CORRIDOR... WHILE GUSTY SOUTHWEST WINDS AND MORE SUNSHINE HELP BOOST TEMPERATURES TO AROUND 80 DEGREES OR SO IN THE SOUTHEAST HALF OF THE FORECAST AREA. UPDATED FORECASTS HAVE BEEN SENT...MAINLY TO ADJUST THE HOURLY TEMPERATURE AND DEW POINT GRIDS. GEELHART && .AVIATION... ISSUED 650 AM CDT THU OCT 4 2012 VFR CONDITIONS ARE FORECAST TO CONTINUE ACROSS THE CENTRAL IL TERMINAL AIRPORTS THE NEXT 24 HOURS THROUGH 12Z/7 AM FRIDAY. A STRONG COLD FRONT EXTENDING FROM DEEPENING 1004 MB LOW PRESSURE OVER NORTH CENTRAL MN INTO EASTERN IA AND NW MO WILL TRACK SE TO THE IL RIVER NEAR PIA BY 21Z/4 PM THIS AFTERNOON AND TO DEC AND CMI AROUND SUNSET BETWEEN 00Z-01Z. BROKEN TO OVERCAST MID/HIGH CLOUDS ABOVE 7K FT TO SPREAD EAST ACROSS IL LATER THIS MORNING AND AFTERNOON AHEAD OF COLD FRONT. SSW WINDS NEAR 10 KTS EARLY THIS MORNING TO BECOME BREEZY SW AFTER 15Z/10 AM TODAY AND INCREASE TO AROUND 15 KTS WITH GUSTS 22-27 KTS BY AFTERNOON. A FEW SHOWERS AND ISOLATED THUNDERSTORMS BEHIND THE FRONT WILL MOVE INTO PIA LATE THIS AFTERNOON...NEAR I-55 FOR BMI/SPI BY SUNSET AND TO DEC AND CMI EARLY THIS EVENING. CARRIED VCTS AT PIA WHERE BEST INSTABILITY IS LATE TODAY AND VCSH REMAINDER OF CENTRAL IL AIRPORTS. SW WINDS TURN NW BEHIND THE COLD FRONT AND DIMINISH TO 8-14 KTS THIS EVENING AND NNW 5-10 KTS OVERNIGHT. WEAK SURFACE LOW PRESSURE MOVING INTO THE LOWER OHIO VALLEY OVERNIGHT TO HAVE INCREASING ISENTROPIC LIFT AND DEVELOP LIGHT RAIN INTO PARTS OF CENTRAL IL DURING OVERNIGHT BUT STILL THINK VFR VSBYS AND CEILINGS OVERNIGHT ABOVE 5 MILES/3K FT. KH && .PREV DISCUSSION... ISSUED 234 AM CDT THU OCT 4 2012 SHORT TERM...TODAY THROUGH SATURDAY UPPER TROUGH THAT HAS PLAGUED CENTRAL ILLINOIS FOR THE PAST FEW DAYS IS FINALLY BEING EJECTED NORTHEASTWARD EARLY THIS MORNING. 06Z/1AM RADAR IMAGERY SHOWS SCATTERED LIGHT SHOWERS LINGERING EAST OF I-55...HOWEVER THESE WILL PUSH FURTHER EASTWARD INTO INDIANA BY 12Z/7AM. AS A RESULT...AM EXPECTING THE DAY TO START OFF MOSTLY SUNNY ACROSS THE BOARD...BEFORE HIGH CLOUDS BEGIN TO INCREASE FROM THE NORTHWEST BY LATE MORNING. VIGOROUS SHORT-WAVE TROUGH EVIDENT ON LATEST WATER VAPOR IMAGERY OVER SOUTH DAKOTA WILL TRACK E/NE TODAY...DRAGGING A STRONG COLD FRONT INTO ILLINOIS THIS AFTERNOON. BOTH THE NAM AND GFS ARE IN GOOD AGREEMENT WITH THE TIMING OF THE FRONT...PLACING IT ALONG A LINE FROM JUST SOUTH OF CHICAGO TO NEAR SAINT LOUIS BY EARLY EVENING. AHEAD OF THE FRONT...GUSTY SOUTHWESTERLY WINDS WILL TRANSPORT MUCH WARMER AIR INTO THE REGION...WITH AFTERNOON HIGH TEMPERATURES TOPPING OUT IN THE UPPER 70S AND LOWER 80S. PRECIP ASSOCIATED WITH THIS FEATURE WILL BE POST-FRONTAL...SO HAVE CONFINED POPS TO LOCATIONS ALONG AND NORTHWEST OF THE ILLINOIS RIVER BY MID TO LATE AFTERNOON. RAIN CHANCES WILL SPREAD AS FAR EAST AS A DANVILLE TO TAYLORVILLE LINE DURING THE EVENING...AS THE FRONT SINKS SOUTHWARD TOWARD THE OHIO RIVER. GIVEN STRONG UPPER DYNAMICS ASSOCIATED WITH APPROACHING WAVE...WILL INCLUDE ISOLATED THUNDER MENTION THIS AFTERNOON AND EVENING. 850-700MB FRONTOGENESIS INCREASES GREATLY OVERNIGHT AS MID-LEVEL FRONT STALLS ACROSS CENTRAL ILLINOIS. WITH ANOTHER SHORT-WAVE TROUGH RIPPLING ALONG THE BOUNDARY AND THE ATMOSPHERE MOISTENING FURTHER...EXPECT SHOWERS TO INCREASE IN AREAL COVERAGE AFTER MIDNIGHT. BOTH THE NAM AND GFS HAVE SHIFTED THIS POST-FRONTAL RAINFALL FURTHER NORTHWARD...WITH THE GFS SHOWING THE GREATEST NORTHWARD TREND. WILL FOLLOW THE SLIGHTLY MORE CONSISTENT NAM IN THE SHORT-TERM...WHICH DEVELOPS RAIN ACROSS ALL LOCATIONS ALONG/NORTH OF I-70 OVERNIGHT INTO FRIDAY MORNING. HAVE BUMPED POPS UP TO LIKELY ACCORDINGLY. SHOWERS WILL CONTINUE ACROSS MUCH OF CENTRAL AND SOUTHEAST ILLINOIS ON FRIDAY...AS FRONT MAKES ONLY GRADUAL PROGRESS SOUTHWARD. FORECAST SOUNDINGS SHOW RATHER STEEP LAPSE RATES ABOVE 700MB...SUGGESTING THE POTENTIAL FOR A FEW THUNDERSTORMS AS WELL. SPC DAY 2 CONVECTIVE OUTLOOK PLACES A GOOD PORTION OF THE AREA IN THE GENERAL THUNDER CATEGORY...SO HAVE INCLUDED ISOLATED THUNDER MENTION ALONG AND SOUTH OF A BLOOMINGTON TO RUSHVILLE LINE. WITH RAIN AND COOL N/NE FLOW BEHIND THE FRONT...TEMPERATURES ON FRIDAY WILL BE MUCH COOLER THAN TODAY...WITH MOST LOCATIONS REMAINING IN THE LOWER TO MIDDLE 50S. AS UPPER WAVE SHIFTS OFF TO THE EAST...FRONT WILL GET PUSHED FURTHER SOUTH FRIDAY NIGHT. WILL CARRY POPS ALONG/SOUTH OF I-72 DURING THE EVENING...THEN JUST SOUTH OF I-70 AFTER MIDNIGHT. TOTAL RAINFALL FROM THIS SYSTEM WILL BE HEAVIEST ACROSS THE HEART OF CENTRAL ILLINOIS FROM THE CHAMPAIGN AREA WESTWARD TO JACKSONVILLE...WHERE AMOUNTS OF AROUND ONE HALF INCH WILL BE COMMON. THE LIGHTEST RAINFALL OF ONE QUARTER OF AN INCH OR LESS WILL OCCUR FURTHER NORTH FROM THE PEORIA AREA NORTHWARD. DRY WEATHER WILL RETURN ON SATURDAY...HOWEVER THERE IS STILL SOME QUESTION CONCERNING ANOTHER UPPER-LEVEL WAVE DROPPING OUT OF THE NORTHERN PLAINS. THIS FEATURE HAS THE POTENTIAL TO LIFT PRECIP BACK NORTHWARD TOWARD THE SE KILX CWA SATURDAY NIGHT...HOWEVER BOTH THE NAM AND GFS NOW KEEP THE RAIN SOUTH OF THE AREA ACROSS THE OHIO RIVER VALLEY. MEANWHILE...THE 00Z 4 OCT ECMWF BRINGS THE PRECIP MUCH FURTHER NORTH INTO EAST-CENTRAL AND SOUTHEAST ILLINOIS. AT THIS POINT...WILL MAINTAIN CLOUD COVER ACROSS THE E/SE SATURDAY NIGHT...BUT WILL KEEP RAIN OUT OF THE FORECAST. MAIN STORY SATURDAY NIGHT WILL BE THE MUCH COLDER CONDITIONS...AS TEMPERATURES POTENTIALLY DIP INTO THE LOWER 30S ALONG/NORTHWEST OF I-55. LONG TERM...SUNDAY THROUGH WEDNESDAY CHILLY CONDITIONS WILL PREVAIL ON SUNDAY...WITH HIGHS ONLY IN THE 50S AND OVERNIGHT LOWS ONCE AGAIN DIPPING INTO THE LOWER TO MIDDLE 30S. AFTER THAT...RETURN FLOW ON THE BACK SIDE OF DEPARTING HIGH PRESSURE WILL BRING MODERATING TEMPS EARLY NEXT WEEK. WITH 850MB TEMPS REACHING THE 6 TO 8C RANGE...HIGH TEMPS WILL CLIMB BACK INTO THE MIDDLE 60S BY TUESDAY. NEXT WEAK COLD FRONT IS SLATED TO PASS THROUGH THE REGION BY THE MIDDLE OF NEXT WEEK...WITH MODEL CONSENSUS BRINGING THE FRONT THROUGH CENTRAL ILLINOIS TUESDAY NIGHT. WILL CARRY LOW CHANCE POPS WITH FROPA...FOLLOWED BY COOL/DRY WEATHER FOR WEDNESDAY. BARNES && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
502 AM MDT THU OCT 4 2012 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 240 AM MDT THU OCT 4 2012 LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS PROGRESSIVE PATTERN IN PLACE ACROSS THE CONUS...WITH REX BLOCK STILL IN PLACE OVER THE PACIFIC. THE NEAREST FEATURE IS A NEGATIVELY TILTED SHORTWAVE TROUGH OVER THE DAKOTAS...WITH W/NW FLOW IN PLACE OVER THE CWA. AT THE SURFACE THE STRONG COLD FRONT PASSED THROUGH THE CWA BEFORE MIDNIGHT AND IS NOW EXTENDING FROM THE OKLAHOMA PANHANDLE ACROSS CENTRAL KANSAS TOWARDS CENTRAL MINNESOTA. TEMPERATURES ALREADY DROPPING INTO THE MID 30S ACROSS THE WEST DESPITE WINDS AROUND 15-25KT AND MID-HIGH CLOUD DECK. THE MAJOR FORECAST FOCUS THROUGH THIS WEEKEND IS ON THE COLD TEMPERATURES SETTLING IN OVER THE PLAINS AND PRECIP CHANCES FRIDAY THROUGH SATURDAY. GUIDANCE IS IN REASONABLY GOOD AGREEMENT FOR TONIGHT THAT TEMPERATURES TONIGHT SHOULD DROP DOWN INTO THE LOW TO MID 30S ACROSS THE AREA. I HAVE QUESTIONS TO HOW COLD IT WILL REALLY GET CONSIDERING THE INCREASING CLOUD COVER AND WINDS AROUND 10KT ACROSS THE WEST. WHILE I CANT RULE OUT FREEZE WARNING CRITERIA BEING MET AT TRADITIONAL COLD SPOTS MY CONFIDENCE IS NOT THERE. I AM HOLDING OFF ON ISSUANCE OF ANY PRODUCTS DUE TO UNCERTAINTIES. MUCH COLDER TEMPERATURES ARE EXPECTED FRIDAY THROUGH SATURDAY NIGHT...WITH DAYTIME HIGHS IN THE 40S. ON SATURDAY LOCATIONS IN THE WEST MAY NOT BE MUCH WARMER THAN THE UPPER 30S FOR HIGHS WITH PRECIPITATION AND LOW CLOUDS POSSIBLY LINGERING INTO THE AFTERNOON. A HARD FREEZE WILL BE POSSIBLE FRIDAY NIGHT...WITH MOST LOCATIONS IN THE LOW 30S. WITH CLEARING SKIES AND LIGHTER WINDS SATURDAY NIGHT A KILLING FREEZE APPEARS LIKELY WITH LOW TEMPERATURES IN THE MID TO UPPER 20S ACROSS THE AREA. A SERIES OF SHORTWAVE TROUGHS WILL ROTATE ALONG THE BASE OF THE LARGE SCALE TROUGH OVER THE CWA FRIDAY THROUGH SATURDAY EVENING. THE BEST CHANCE FOR MEASURABLE PRECIP SHOULD BE LATE FRIDAY NIGHT THROUGH SATURDAY MORNING...COINCIDING WITH A COUPLED 300MB JET STRUCTURE AND UPSLOPE FLOW ACROSS THE WEST. NAM/SREF WOULD ACTUALLY SUPPORT SOME MESOSCALE BANDING ASSOCIATED WITH A H7 TROUGH OVER NE COLORADO...AND ARE PRODUCING HIGHER QPF VALUES AS A RESULT. IM NOT SURE ABOUT THIS SOLUTION...HOWEVER IT IS CERTAINLY POSSIBLE. OVERALL MOST PRECIP SHOULD BE ON THE LIGHT SIDE. PHASE CHANGE WILL BE COMPLICATED...WITH A RAIN/SNOW CHANGE OVER POSSIBLE IN THE MORNING AND OVERNIGHT PERIODS. THE BEST CHANCE FOR ACCUMULATING SNOW REMAINS IN THE WEST...WITH AROUND HALF AN INCH POSSIBLE ON GRASSY SURFACES BY SATURDAY MORNING ALONG AND WEST OF THE CO/KS STATE LINE. THIS COULD BE A LITTLE HIGHER IF THE NAM/SREF SOLUTION WERE TO VERIFY. DUE TO WARM GROUND TEMPERATURES IT STILL LOOKS LIKE SNOW ACCUMULATION SHOULD BE LIMITED TO GRASSY AREAS AND ELEVATED SURFACES. .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 240 AM MDT THU OCT 4 2012 COOL AND DRY WEATHER IS EXPECTED THROUGH THE EXTENDED PERIOD WITH THE CENTRAL PLAINS PRIMARILY DOMINATED BY NORTHWEST FLOW ALOFT. SEVERAL UPPER LEVEL SHORT WAVE TROUGHS ARE FORECAST TO DROP SOUTHEAST ACROSS THE NORTHERN ROCKIES AND NORTHERN PLAINS THROUGH THE PERIOD...BRUSHING THE CENTRAL HIGH PLAINS. THIS WILL KEEP TEMPERATURES ON THE COOL SIDE FOR DAYTIME HIGHS AS SURFACE CANADIAN AIR IS PERIODICALLY REFRESHED AFTER EACH UPPER TROUGH PASSAGE. LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED...AS THE MAIN DYNAMICS/LIFT DURING PERIOD WILL STAY TO THE NORTH. SUNDAY WILL LIKELY BE THE COOLEST DAY IN THIS EXTENDED PERIOD WITH HIGHS IN THE 50S AFTER A POTENTIAL HARD FREEZE THAT MORNING. 850 MB TEMPERATURES STARTING AROUND 0C SUNDAY MORNING ARE FORECAST TO WARM TO AROUND 10C BY MONDAY AND CONTINUE HOVERING IN THE 8-14C RANGE THROUGH MID-WEEK WHICH SHOULD TRANSLATE TO HIGHS GENERALLY IN THE 60S AND LOWS IN THE 30S MONDAY AND 40S FOR TUE/WED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 500 AM MDT THU OCT 4 2012 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD AT BOTH KGLD AND KMCK. LATEST SATELLITE AND OBS INDICATE STRATUS DECK AROUND 5000KFT BEGINNING TO DEVELOP TO THE SOUTHEAST OF BOTH TERMINALS NEAR HILL CITY AND TRIBUNE KANSAS. AT THE MOMENT CONFIDENCE IS HIGH THAT THIS WILL REMAIN AWAY FROM KGLD AND KMCK TERMINALS...AND SHOULD REMAIN WITHIN VFR RANGE EVEN IF IT WERE TO DEVELOP FURTHER WEST. NORTHERLY WINDS GUSTING TO 20KT AT BOTH TERMINALS WILL DIMINISH THROUGH MIDDAY...WITH LIGHT EAST/NORTHEAST WINDS AROUND 10KT EXPECTED THROUGH THE REMAINING TAF PERIOD AS SURFACE GRADIENT CONTINUES TO WEAKEN. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...DLF AVIATION...DR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
903 AM EDT THU OCT 4 2012 .SYNOPSIS... ISSUED AT 356 AM EDT THU OCT 4 2012 WE/LL HAVE ONE MORE MILD DAY TODAY BEFORE A STRONG COLD FRONT ARRIVES TOWARD EVENING AND SENDS THE TEMPERATURE FALLING. SHOWERS EARLY THIS MORNING WILL GIVE WAY TO PARTLY SUNNY SKIES BY MID DAY. SOUTHWEST WINDS WILL BOOST TEMPERATURES INTO THE MID 70S. THUNDERSTORMS ARE POSSIBLE NEAR THE COLD FRONT TOWARD EVENING. TEMPERATURES WILL ONLY CLIMB INTO THE 50S THROUGH EARLY NEXT WEEK WITH UPPER 40S EXPECTED SUNDAY. && .UPDATE... ISSUED AT 904 AM EDT THU OCT 4 2012 I UPDATED THE GRIDS AND ZONE FORECAST TO TIME OUT THE RAIN MORE QUICKLY. I USED THE HRRR RUC TO HELP MY CAUSE (10Z VERSION). IT SHOULD BECOME MOSTLY CLEAR BY MID DAY BASED ON SAT LOOPS AND MODEL RH DATA. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 356 AM EDT THU OCT 4 2012 FORECAST CONCERNS DEAL WITH PCPN TRENDS THROUGH THE PERIOD. OVERALL... THE FORECAST HAS NOT CHANGED MUCH. RADAR SHOWS SHOWERS MOVING ACROSS THE CWA. MOST OF THE PCPN WAS NORTH OF I-96 BUT ANOTHER AREA WAS MOVING TOWARD LWR MI AND WAS OVER ERN IL. THESE AREAS OF PCPN ARE ASSOCIATED WITH UPPER WAVES MOVING THROUGH THE GREAT LAKES AND WILL DIMINISH THIS MORNING. WEAK SHORT WAVE RIDGING AHEAD OF THE APPROACHING COLD FRONT WILL RESULT IN SOME SUNSHINE THIS AFTERNOON AND SW WINDS WILL BOOST TEMPS WELL INTO THE 70S. BY LATE IN THE DAY SHOWERS AND SCATTERED STORMS WILL DEVELOP. NCEP AND NSSL WRF MODELS SHOW A LINE OF SHOWERS/STORMS DEVELOPING AROUND 23Z OVER ERN LAKE MICHIGAN AND SWEEPING ACROSS THE CWA DURING THE EVENING. 00Z MODELS SHOW A LITTLE STRONGER INSTABILITY THAN PREVIOUS RUNS. IN FACT SHEAR VALUES NEAR 40 KTS SUGGEST THAT A FEW OF THE STORMS COULD PRODUCE STRONG WINDS. MID LEVEL WINDS NEAR 50 KTS WILL PUSH THE LINE EWD QUICKLY AND SHOULD BE MOSTLY EAST OF THE CWA BY 06Z. FRIDAY LOOKS GENERALLY DRY EXCEPT FOR THE FAR SE CWA CLOSER TO THE FRONTAL BOUNDARY. CERTAINLY COOLER THOUGH WITH HIGHS IN THE 50S. UPPER TROUGH WILL BE SWINGING THROUGH SATURDAY WITH STRONG DPVA. SCT SHOWERS EXPECTED ACROSS THE CWA. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 356 AM EDT THU OCT 4 2012 LONG TERM BEGINS WITH AN UPPER TROUGH OVERHEAD AND LAKE EFFECT RAIN SHOWERS ONGOING OFF OF LAKE MICHIGAN IN NORTHWEST FLOW. SATURDAY NIGHT SHOULD FEATURE PLENTY OF SHOWER ACTIVITY OFF THE LAKE WITH DELTA T/S AROUND 20 DEG C. NOT OUT OF THE REALM OF POSSIBILITIES OF SEEING A LITTLE LIGHT SNOW MIX IN AWAY FROM LAKE MICHIGAN ACROSS CENTRAL LOWER MICHIGAN SATURDAY NIGHT INTO SUNDAY MORNING. DO NOT HAVE SNOW IN THE FORECAST AT THIS POINT. FEEL SUNDAY WILL TRY TO DRY OUT...AS THE MOISTURE WANES. STILL HAVE A CHANCE FOR SHOWERS IN THE FORECAST THOUGH WITH DELTA T/S HOLDING AROUND 20 DEGREES. SUNDAY NIGHT THROUGH MONDAY NIGHT HAVE A DRY FORECAST IN PLACE AS A SURFACE RIDGE FLOATS THROUGH THE REGION. RAIN CHANCES INCREASE TUESDAY NIGHT INTO WEDNESDAY AS A SHORTWAVE TROUGH ROTATES THROUGH THE FLOW. BELOW NORMAL TEMPS SUNDAY AND MONDAY RETURNING BACK TO NORMAL ON TUESDAY. COLD AIR PUSHES BACK INTO THE GREAT LAKES FOR WEDNESDAY. AS IS TYPICAL IN THE FALL...TEMPS WILL BE UP AND DOWN IN THE LONG TERM. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 756 AM EDT THU OCT 4 2012 RAIN IS LIFTING OUT TO THE EAST AT 12Z...AND THE RAIN/FOG SHOULD BE OVER BY 14Z AT THE TAF SITES. LOW CEILINGS ARE IN THE PROCESS OF LIFTING OUT...WITH GRR THE ONLY SITE WITH SOME MVFR CEILINGS. THESE LOWER CEILINGS SHOULD ALSO BE GONE BY MID MORNING. THE REASON THE LOWER CLOUD AND RAIN/FOG ARE COMING TO A QUICK END IS THAT THE TROUGH THAT DEVELOPED IT IS QUICKLY MOVING EAST AS WELL. THE BULK OF THE DAY WILL BE VFR AS SOUTHWESTERLY WARM WINDS DEVELOP QUICKLY THIS MORNING AHEAD OF OUR NEXT FRONT. MAINLY SCATTERED CLOUDS ARE EXPECTED FROM LATE MORNING THROUGH THE AFTERNOON WITH NO RESTRICTIONS TO VISIBILITY. A COLD FRONT WILL SWEEP IN FROM THE WEST THIS EVENING AND BRING A BAND OF SHOWERS AND POSSIBLY A FEW THUNDERSTORMS TO THE TAF SITES BETWEEN 22Z AND 05Z. THE STORMS HAVE THE BEST CHANCE OF OCCURRING AT KMKG...KGRR AND KAZO AS LAKE MOISTURE HELPS THE DEVELOPMENT. VFR AFTER 05Z TONIGHT. IT WILL BE BREEZY THIS AFTERNOON. && .MARINE... ISSUED AT 356 AM EDT THU OCT 4 2012 EXPANDED THE SCA TO INCLUDE THE ENTIRE NEARSHORE AREA. GUSTY SOUTHWEST WINDS AHEAD OF THE COLD FRONT EXPECTED THIS AFTERNOON WILL BOOST WAVES TO 5-7 FT NORTH OF GRAND HAVEN. WINDS WILL SHIFT TO THE NORTHWEST BY EARLY EVENING. && .HYDROLOGY... ISSUED AT 356 AM EDT THU OCT 4 2012 QPF LESS THAN A QUARTER INCH WILL NOT SIGNIFICANTLY IMPACT AREA RIVERS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY FROM NOON TODAY TO 8 PM EDT FRIDAY FOR LMZ844>849. && $$ UPDATE...WDM SYNOPSIS...93 SHORT TERM...93 LONG TERM...DUKE AVIATION...DUKE HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
627 AM CDT Thu Oct 4 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Short Term (Today through Saturday Night)... 08Z surface analysis shows well defined cold front has pushed into far NW MO. Earlier surface based convection has long since dissipated, with pockets of post frontal elevated convection having a better go at it between Omaha to north central KS. RAP soundings show that modest elevated instability (100-300 J/Kg CAPE) will overspread NE KS and NW MO toward daybreak, supporting scattered showers and perhaps a few thunderstorms. Today: Precipitation won`t be the only issue to contend with as the temperature forecast will be equally, if not more challenging. High resolution models show that the frontal speed and cold advection will slow with time due to a combination of daytime mixing and a shift of post frontal precipitation toward the northeast. Southerly winds and weak moisture advection were providing a mild start across the warm sector, and so it seems likely that temperatures will quickly rebound to near yesterday`s maxes, with mid to upper 70s likely over mid Missouri under abundant sunshine. Across the front in far northwest Missouri, strong cold advection and cloud cover suggest that effective highs may be reached at 12Z with only a modest afternoon recovery in the wake of morning convection. It`s possible that my 60F highs here may be perhaps generous. In between these extrema, the forecast is even more nebulous as highs could be reached mid-late morning with temps steady or slowly falling in the afternoon depending on the offset between cold advection and daytime heating. With respect to POPs, the orientation of the frontal axis and elevated instability axis is reflected in keeping scattered shra/-tsra mainly north of a Kansas City to Kirksville axis for today. Coverage will be limited by weakening ascent and ambient dry mid level air, so 30-40 POPs look kosher. Tonight: The surface front should eventually fizzle just southeast of the CWA this evening as large scale height falls finally arrive from the northwest. The arrival of stronger mid level flow will help sharpen a deep layer thermal gradient, with model cross sections showing a classic strengthening of layered/tilted frontogenesis beneath the mid-upper jet cores. Condensation pressure deficits indicate a fairly rapid top-down saturation this evening along and south of a Kansas City-Kirksville line, with some convective instability present as well. Thus, expect a blossoming of an axis of showers embedded thunder between 00 and 06Z over the srn half of the CWA, or perhaps a resurgence of whatever lingers from the daytime hours. Have increased POPs to around 60 percent for areas south of the MO river and brought POPs back toward the northwest overnight. Temperatures will steadily fall via strong cold advection and evaporative cooling, leading to some very raw conditions where precipitation is ongoing. Friday: This process should continue through the daytime Friday with bands of mainly light rain persisting ahead of the large upper trough axis still to the north and west. Surface pressure rises will continue under moderate cold advection, leading to some pretty miserable conditions as temperatures struggle to break the 50 degree mark. Friday Night-Saturday: Layered frontogenesis should slowly shift south and east, allowing precipitation to gradually end from the northwest. Extensive cloudiness and perhaps even some drizzle will linger as the deepening longwave trough still remains well northwest of the area. Mid-high level RH values confirm this idea, and again temperatures will run some 20+ degrees below normal. Saturday Night: With the passage of the upper trough, skies should clear, coincident with the arrival of the surface ridge axis. Temperatures will likely plummet after midnight, with near certainty that the coldest night of the early autumn season is upon us. Widespread frost looks almost a given and some sheltered areas across NW Missouri could dip below freezing for an hour or two. Bookbinder Medium Range (Sunday through Wednesday)... Cool temperatures will still be prevailing as the end of the weekend arrives, though some moderation is in store for the work week. A pronounced trough will still be in control of the weather across the Plains, pushing a cold Canadian surface high through the Lower Missouri River Valley. The consensus amongst the medium range models is for the trough pushing this cold air to continue dominating the weather across the eastern half of the nation through the work week. However, with a series of shortwaves expected to drop into, and then move through this broader longwave feature, it wont be all cold air advection for next week. For Sunday, the center of the cold Canadian surface high will be sliding off to our east, allowing the first hints at a return flow to develop by late in the day. The return flow that will be in place by Monday should allow afternoon readings to jump back into the 60s, with that temperature range expected to persist through at least the middle of the work week. This temperature regime will also support overnight lows in the 40s, so any weekend frost issues are not expected to persist into the work week at this time. Otherwise, have continued to carry some silent slight chance POPs from Tuesday into Tuesday night. Several models advertise a shortwave rotating through the broader trough in that time period. Warm air advection on the back side of the exiting surface high, ahead of another weak frontal boundary, could squeeze some drops from the air. But, given the many questions on timing and moisture availability have opted to leave the POPs in the silent slight chance range. Otherwise, consensus model output inserted more POPs for Wednesday. These did not look reasonable given the surface high expected to be shifting through the Plains States during that period, so have yanked them out. Cutter && .AVIATION... For the 12Z TAFs...cold front advancing across the Kansas-Missouri border line will likely be through all the terminals by the time this TAF cycle starts. This will leave, at times, a gusty north to northwest wind prevailing through the day. Gusty winds are expected to be worst in the morning hours just behind the front. Otherwise, cloud cover behind the advancing front is not generally expected to lower too much today owing to the dry boundary layer, but some showers are expected to develop from these high based clouds this afternoon and this evening, though little impairment to flying conditions is currently expected. Otherwise, late tonight winds will calm some as they veer to the northeast. Cutter && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
800 AM CDT THU OCT 4 2012 .UPDATE...SENT AN UPDATE TO THE FORECAST TO REMOVE THE CHANCE OF THUNDER ACROSS SOUTHEASTERN PORTIONS OF THE FORECAST AREA OVER THE NEXT FEW HOURS...AS INSTABILITY AXIS IS PUSHING FURTHER EAST AND ONLY A LIGHT SHOWER OR SPRINKLE CAN BE EXPECTED OVER THE NEXT COUPLE OF HOURS. OTHERWISE...NO ADDITIONAL CHANGES MADE TO PREVIOUS FORECAST AT THIS TIME. && .PREV DISCUSSION... /ISSUED 558 AM CDT THU OCT 4 2012/ AVIATION...12Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL PERSIST AT THE TERMINAL...BUT NOTHING BELOW 8000FT AGL ARE CURRENTLY EXPECTED. THE SURFACE WIND WILL START THE DAY FROM THE NORTH...SUSTAINED AT AROUND 17KTS AND GUSTING TO AROUND 25KTS...BUT WILL DECREASE IN INTENSITY THROUGH THE DAY. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS. PREV DISCUSSION... /ISSUED 451 AM CDT THU OCT 4 2012/ SHORT TERM...THROUGH SATURDAY NIGHT. ALTHOUGH CHANCES OF LEGITIMATE...WIDESPREAD MEASURABLE PRECIPITATION WITHIN THE CWA DURING THE NEXT 72 HOURS ARE GENERALLY QUITE LOW...THE FORECAST PRESENTS PLENTY OF CHALLENGES PRIMARILY IN THE OVERNIGHT LOW TEMPERATURE DEPARTMENT...WITH THE ULTIMATE QUESTION EACH OF THE NEXT 3 NIGHTS BEING JUST HOW COLD WILL IT ACTUALLY GET...AS IT COULD BE A DICEY BATTLE BETWEEN A VERY COOL AIRMASS AND CLOUD COVER TRYING TO HOLD SOME AREAS UP A BIT. FOR NOW HAVE HELD OFF ON ANY FROST/FREEZE HEADLINES...BUT WILL CONTINUE TO HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK. STARTING OFF RIGHT AWAY THIS MORNING...AS I TYPE A SOMEWHAT SURPRISINGLY STRONG THUNDERSTORM WITH CONFIRMED PENNY/NICKLE HAIL IS QUICKLY SLIDING EAST ACROSS JEWELL COUNTY KS...AND SHOULD BE EXITING THE CWA WITHIN THE NEXT HOUR. EARLIER IN THE NIGHT...A FEW OTHER STRONG STORMS LIKELY WITH SMALL HAIL ALSO AFFECTED NEB ZONES INCLUDING BOTH THE FRANKLIN/MERRICK COUNTY AREAS. OTHERWISE...THE VAST MAJORITY OF THE CWA IS DRY AT THIS HOUR...WITH STEADY NORTHWEST WINDS OF 15-20 MPH AND HIGHER GUSTS SERVING AS THE MAIN PRE-DAWN ISSUE...ALTHOUGH THE SPORADIC ADVISORY LEVEL SUSTAINED SPEEDS OF 30+ MPH THAT WERE BEING REPORTED A FEW HOURS AGO HAVE LARGELY TAMED DOWN A BIT. 08Z OBJECTIVE SURFACE ANALYSIS PUTS THE LEADING EDGE OF THIS FIRST TRULY STRONG COLD FRONT OF THE FALL SEASON ALONG A LINE FROM SOUTH CENTRAL KS TO WESTERN IA...HAVING PASSED THROUGH THE ENTIRE CWA. THIS FRONT IS TRAILING FROM A 1005MB LOW OVER CENTRAL MN...WITH GUSTY NORTHWEST WINDS BEING POWERED BY CONTINUED MODEST PRESSURE RISES WELL TO THE SOUTHEAST OF AN EXPANSIVE 1036MB HIGH CENTERED OVER THE MT AREA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRMS STRENGTHENING ZONAL FLOW ACROSS THE CENTRAL PLAINS...ALONG THE SOUTHERN PERIPHERY OF A STRONG MID LEVEL VORT MAX SWINGING EAST ACROSS THE DAKOTAS INTO MN. FOR THE FIRST FEW HOURS THROUGH SUNRISE THIS MORNING...HAVE LINGERED A SCATTERED THUNDERSTORM MENTION ACROSS SEVERAL FAR EASTERN/SOUTHEAST COUNTIES TO ACCOUNT FOR ONGOING ACTIVITY. THESE SHOWERS/STORMS ARE GENERALLY TIED TO A STRONG ZONE OF FRONTOGENESIS IN THE 850-700MB LAYER...AND ACCORDING TO 08Z MESOSCALE ANALYSIS ARE TAKING FULL ADVANTAGE OF ONLY AROUND 500 J/KG OF ELEVATED CAPE...BUT WITH INCREASING DEEP-LAYER 0-6KM SHEAR NOW UP INTO THE 30-40KT RANGE. WOULD EXPECT A CONTINUED THREAT OF HAIL UP TO THE PENNY-ISH SIZE RANGE AS LONG AS THIS CONVECTION CONTINUES TO LINGER IN SOUTHEAST ZONES EARLY THIS MORNING. GETTING INTO THE OFFICIAL DAYTIME 12Z-00Z PERIOD...AT LEAST FOR NOW CONTINUED TO LINGER A SCATTERED SHOWER/STORM MENTION IN A HANDFUL OF FAR SOUTHEAST COUNTIES THROUGH 15Z...BUT ACCORDING TO REFLECTIVITY TRENDS FROM THE 06Z HRRR THIS IS PROBABLY BEING PLENTY GENEROUS...AS MOST CONVECTION SHOULD FINALLY BE OUT OF THE CWA BY SUNRISE OR SO. ONCE THIS ONGOING PESKY STRONG CONVECTION GETS OUT OF HERE...THE MAJORITY OF THE DAY SHOULD BE FAIRLY UNEVENTFUL AND DRY WITHIN THE CWA...WITH SKIES FOR MOST OF THE DAY AVERAGING NO WORSE THAN PARTLY CLOUDY IF NOT MOSTLY SUNNY. IT GOES WITHOUT SAYING THAT THOSE NOT PAYING ATTENTION THE LAST FEW DAYS WILL BE CAUGHT OFF GUARD BY THE 25-30 DEGREE DROP IN TEMPS FROM YESTERDAY. KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...BUT BASED ON EXPECTATION OF SOME SUN AND DECENT MIXING...ACTUALLY NUDGED UP MOST AREAS 1-2 DEGREES...BUT STILL KEEPING NEARLY ALL AREAS A FEW DEGREES EITHER SIDE OF 60. ALTHOUGH WINDS WILL REMAIN QUITE BREEZY THIS MORNING WITH GUSTS OF AT LEAST 25-30 MPH STILL COMMON...A STEADY DECREASING TREND WILL CONTINUE THROUGH THE DAY WITH SUSTAINED SPEEDS THIS AFTERNOON AVERAGING AROUND 15 MPH OR LOWER. TONIGHT...NORTH-NORTHEAST BREEZES OF NO MORE THAN 5-10 MPH WILL PREVAIL CWA-WIDE AS SURFACE HIGH PRESSURE SETTLES DEEPER INTO THE REGION. HOWEVER...CLOUD TRENDS WILL PROVE TRICKY...AS THE REGION COMES UNDER INCREASING UPPER LEVEL JET ENTRANCE REGION DYNAMICS AS A BROAD TROUGH CONTINUES SETTLING INTO THE CENTRAL/NORTHERN PLAINS. ALTHOUGH THE FORECAST FOR TONIGHT WAS LEFT VOID OF PRECIP MENTION...ISENTROPIC LIFT EVIDENT AROUND THE 700MB LEVEL SHOULD PROMOTE A STEADILY EXTENDING BAND OF MID LEVEL CLOUDS ACROSS MOST OF THE CWA ESPECIALLY AFTER MIDNIGHT...WITH THE BEST POTENTIAL FOR PRECIP REMAINING WEST OF THE CWA. HOWEVER...CERTAINLY CANNOT RULE OUT A FEW SPRINKLES LATE TONIGHT ESPECIALLY IN SOUTHERN ZONES BUT WILL KEEP EVEN THIS MENTION OUT FOR NOW. ALTHOUGH MET/MAV GUIDANCE CAME IN QUITE CHILLY FOR TONIGHTS LOWS...OPTED TO KEEP THE OFFICIAL FORECAST AT LEAST 3 DEGREES ABOVE THIS GUIDANCE CONSENSUS IN MOST AREAS TO ACCOUNT FOR EXPECTATION OF INCREASING CLOUDS THROUGH THE NIGHT. THIS YIELDED A SLIGHTLY WARMER LOW TEMP FORECAST THAN PREVIOUS...BUT STILL BRINGS MOST NEB ZONES INTO THE LOW-MID 30S...BUT RANGING FROM UPPER 20S FAR NORTH TO UPPER 30S IN MOST KS ZONES. ALTHOUGH A MARGINAL FREEZE AND/OR PATCHY FROST IS VERY POSSIBLE TONIGHT ACROSS MOST NEB ZONES...THE UNCERTAINTY IN HOW MUCH CLOUD COVER COULD HOLD THINGS UP...ALONG WITH THE FACT THAT THE NEXT FEW NIGHTS SHOULD BE EVEN COLDER...HAS KEPT ME FROM ISSUING A FORMAL FROST/FREEZE HEADLINE FOR TONIGHT AT THIS TIME. FRIDAY DAYTIME...SUBTLE SHORTWAVE ENERGY CONTINUES TO TRACK WEST- EAST ACROSS THE CWA UNDERNEATH ONE OF THE STRONGER...MOST PERSISTENT UPPER LEVEL JETS SEEN IN AWHILE. PERSISTENT MID LEVEL LIFT UNDERNEATH THIS JET CORE SHOULD KEEP PLENTY OF MID-HIGH CLOUDS AROUND DURING THE DAY. AS FOR RAIN CHANCES...CONVERTED ZONE FORECAST WORDING TO SLIGHT CHANCE OF LIGHT RAIN ACROSS MOST OF THE CWA...WITH THE OVERALL BEST RISK FOR POSSIBLY A FEW HUNDREDTHS TARGETING THE SOUTHWEST 1/2 OF THE AREA. IF THE LOW LEVEL THERMAL PROFILE SETS UP JUST RIGHT...SUPPOSE A FEW SNOWFLAKES ARE POSSIBLE DURING THE MORNING IN THE WEST AROUND THE DAWSON COUNTY AREA...BUT WITH LIGHT RAIN MORE LIKELY TO DOMINATE HAVE LEFT THIS AS THE ONLY PRECIP TYPE MENTION FOR NOW. FOR HIGH TEMPS NUDGED UP EASTERN ZONES VERY SLIGHTLY BUT OTHERWISE LITTLE CHANGE WITH HIGHS IN MOST AREAS ONLY LOW-MID 50S BUT MAYBE ONLY UPPER 40S IN PARTS OF THE WEST. FRIDAY NIGHT...A MID LEVEL SHORTWAVE OVER THE DAKOTAS WILL SINK SOUTH TOWARD THE REGION...AS FAST ZONAL FLOW CONTINUES IN THE UPPER LEVELS. LINGERED A SLIGHT CHANCE OF LIGHT RAIN IN FAR SOUTHERN/SOUTHWEST ZONES THROUGH THE NIGHT...BUT THE LATEST TRENDS HAVE BEEN FOR THE VAST MAJORITY OF THE CWA TO STAY DRY THROUGH THE NIGHT WITH THE MAIN FOCUS FOR RAIN OR A RAIN-SNOW MIX HOLDING JUST WEST OF THE CWA. AGAIN...CLOUD TRENDS WILL PROVE VERY TRICKY REGARDING HOW COLD IT GETS...AS EXPECT A GRADIENT RANGING FROM MORE CLEAR IN THE NORTHEAST TO MORE CLOUDY IN THE SOUTHWEST. SOME OF MET/MAV GUIDANCE CAME IN QUITE COLD...AND ALTHOUGH DID NOT GO QUITE AS LOW AS THIS GUIDANCE...DID LOWER LOWS A SOLID 2-5 DEGREE FROM PREVIOUS FORECAST...NOW PUTTING MOST AREAS NORTH OF HIGHWAY 6 DOWN IN THE 20S AND AREAS SOUTH INTO KS MAINLY LOW-MID 30S. AS A RESULT...UNLESS CLOUD WREAK HAVOC...MUCH OF THE NORTHERN 1/2 OF THE CWA SHOULD REALIZE ITS FIRST HARD FREEZE OF THE SEASON...WITH FREEZE HEADLINES A DECENT BET DURING THE NEXT FEW FORECAST CYCLES. SATURDAY DAYTIME...THE AFOREMENTIONED SHORTWAVE TO THE NORTH DROPS SOUTH OVER NEB...BUT WITH ANY APPRECIABLE FORCING FOR LIGHT PRECIP STILL ONLY SKIRTING THE FAR SOUTHWESTERN CWA...WHERE A SLIGHT CHANCE OF LIGHT RAIN WAS MAINTAINED. OTHERWISE...NUDGED UP HIGHS VERY SLIGHTLY MOST AREAS BASED ON LATEST GUIDANCE CONSENSUS...BUT WITH MOST AREAS ONLY LOW-MID 50S AND UPPER 40S SOUTHWEST. FINALLY FOR SATURDAY NIGHT...CONFIDENCE IS FAIRLY HIGH THAT IT WILL BE DRY CWA-WIDE...AND GENERALLY CLEARER THAN BOTH TONIGHT/FRIDAY NIGHT AS THE MAIN MID LEVEL WAVE DEPARTS SOUTHEAST TOWARD MO. FOR THOSE AREAS THAT DO NOT HARD-FREEZE FRIDAY NIGHT...SATURDAY NIGHT IS STILL EXPECTED TO PRETTY MUCH PUT THE NAIL IN THE COFFIN ON THE GROWING SEASON...WITH MOST IF NOT OF THE CWA SETTLING AT LEAST INTO THE MID-UPPER 20S. IF THINGS GO AS CURRENTLY ENVISIONED...FRIDAY NIGHT COULD FEATURE THE LAST FREEZE WARNING OF THE SEASON IN ROUGHLY THE NORTHERN 1/2 OF THE CWA...WITH THE SOUTHERN 1/2 LIKELY BEING FINISHED OFF SATURDAY NIGHT. AS ALREADY STATED SEVERAL TIMES THOUGH...MID LEVEL CLOUD TRENDS COULD POTENTIALLY THROW IN A WRENCH IN THESE PLANS HOWEVER...ESPECIALLY IF THEY HOLD UP LOWS HIGHER THAN EXPECTED FRIDAY NIGHT. LONG TERM...STARTING 12Z SUNDAY. LONG TERM GUIDANCE SUGGESTS NORTHWESTERLY TO QUASI-ZONAL MID AND UPPER LEVEL FLOW WILL PERSIST OVER THE CENTRAL PLAINS DURING THE LONG TERM FORECAST PERIOD. A PAIR OF MID LEVEL SHORTWAVES ARE ALSO EXPECTED TO PUSH ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY DURING THE LONG TERM FORECAST PERIOD...ONE DURING THE DAY MONDAY AND THE OTHER ON TUESDAY. BEFORE THE PASSAGE OF THESE MID LEVEL SHORTWAVES HOWEVER...SOUTHERLY LOW LEVEL FLOW AND RESULTANT WARM AIR ADVECTION SHOULD PRESENT A WARMING TREND BOTH SUNDAY AND MONDAY. THE INITIAL MID LEVEL SHORTWAVE ON MONDAY IS THEN EXPECTED TO PROMOTE SURFACE CYCLOGENESIS OVER SOUTHERN ONTARIO...WITH AN ASSOCIATED COLD FRONT EXPECTED TO SWEEP SOUTH/SOUTHEAST ACROSS THE CENTRAL PLAINS EARLY TUESDAY. THE SECOND MID LEVEL SHORTWAVE ON TUESDAY IS THEN EXPECTED TO PROVIDE A REINFORCING SHOT OF LOW LEVEL COLD AIR ADVECTION TO THE AREA TUESDAY NIGHT INTO WEDNESDAY MORNING WITH THE OPERATIONAL GFS...EC AND GEFS-MEAN ALL SUGGESTING A ~1025MB SURFACE HIGH WILL SET UP SHOP NEAR OR OVER OUR AREA BY 12Z WEDNESDAY. GIVEN ALL THIS...WENT AHEAD WITH A COOLING TREND IN TEMPERATURES TUESDAY AND WEDNESDAY. DESPITE THE PASSAGE OF THESE LOW LEVEL BAROCLINIC ZONES...OVERALL KINEMATIC FORCING APPEARS WEAK THROUGHOUT THE LONG TERM FORECAST. IN ADDITION...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE CWA PER THE OPERATIONAL GFS AND EC SUGGEST TROPOSPHERIC MOISTURE WILL BE FAIRLY LACKING DURING THIS SAME TIME PERIOD. GIVEN ALL THIS...THE LONG TERM FORECAST PERIOD REMAINS DRY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...ROSSI SHORT TERM...PFANNKUCH LONG TERM/AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
558 AM CDT THU OCT 4 2012 .AVIATION...12Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL PERSIST AT THE TERMINAL...BUT NOTHING BELOW 8000FT AGL ARE CURRENTLY EXPECTED. THE SURFACE WIND WILL START THE DAY FROM THE NORTH...SUSTAINED AT AROUND 17KTS AND GUSTING TO AROUND 25KTS...BUT WILL DECREASE IN INTENSITY THROUGH THE DAY. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS. && .PREV DISCUSSION... /ISSUED 451 AM CDT THU OCT 4 2012/ SHORT TERM...THROUGH SATURDAY NIGHT. ALTHOUGH CHANCES OF LEGITIMATE...WIDESPREAD MEASURABLE PRECIPITATION WITHIN THE CWA DURING THE NEXT 72 HOURS ARE GENERALLY QUITE LOW...THE FORECAST PRESENTS PLENTY OF CHALLENGES PRIMARILY IN THE OVERNIGHT LOW TEMPERATURE DEPARTMENT...WITH THE ULTIMATE QUESTION EACH OF THE NEXT 3 NIGHTS BEING JUST HOW COLD WILL IT ACTUALLY GET...AS IT COULD BE A DICEY BATTLE BETWEEN A VERY COOL AIRMASS AND CLOUD COVER TRYING TO HOLD SOME AREAS UP A BIT. FOR NOW HAVE HELD OFF ON ANY FROST/FREEZE HEADLINES...BUT WILL CONTINUE TO HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK. STARTING OFF RIGHT AWAY THIS MORNING...AS I TYPE A SOMEWHAT SURPRISINGLY STRONG THUNDERSTORM WITH CONFIRMED PENNY/NICKLE HAIL IS QUICKLY SLIDING EAST ACROSS JEWELL COUNTY KS...AND SHOULD BE EXITING THE CWA WITHIN THE NEXT HOUR. EARLIER IN THE NIGHT...A FEW OTHER STRONG STORMS LIKELY WITH SMALL HAIL ALSO AFFECTED NEB ZONES INCLUDING BOTH THE FRANKLIN/MERRICK COUNTY AREAS. OTHERWISE...THE VAST MAJORITY OF THE CWA IS DRY AT THIS HOUR...WITH STEADY NORTHWEST WINDS OF 15-20 MPH AND HIGHER GUSTS SERVING AS THE MAIN PRE-DAWN ISSUE...ALTHOUGH THE SPORADIC ADVISORY LEVEL SUSTAINED SPEEDS OF 30+ MPH THAT WERE BEING REPORTED A FEW HOURS AGO HAVE LARGELY TAMED DOWN A BIT. 08Z OBJECTIVE SURFACE ANALYSIS PUTS THE LEADING EDGE OF THIS FIRST TRULY STRONG COLD FRONT OF THE FALL SEASON ALONG A LINE FROM SOUTH CENTRAL KS TO WESTERN IA...HAVING PASSED THROUGH THE ENTIRE CWA. THIS FRONT IS TRAILING FROM A 1005MB LOW OVER CENTRAL MN...WITH GUSTY NORTHWEST WINDS BEING POWERED BY CONTINUED MODEST PRESSURE RISES WELL TO THE SOUTHEAST OF AN EXPANSIVE 1036MB HIGH CENTERED OVER THE MT AREA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRMS STRENGTHENING ZONAL FLOW ACROSS THE CENTRAL PLAINS...ALONG THE SOUTHERN PERIPHERY OF A STRONG MID LEVEL VORT MAX SWINGING EAST ACROSS THE DAKOTAS INTO MN. FOR THE FIRST FEW HOURS THROUGH SUNRISE THIS MORNING...HAVE LINGERED A SCATTERED THUNDERSTORM MENTION ACROSS SEVERAL FAR EASTERN/SOUTHEAST COUNTIES TO ACCOUNT FOR ONGOING ACTIVITY. THESE SHOWERS/STORMS ARE GENERALLY TIED TO A STRONG ZONE OF FRONTOGENESIS IN THE 850-700MB LAYER...AND ACCORDING TO 08Z MESOSCALE ANALYSIS ARE TAKING FULL ADVANTAGE OF ONLY AROUND 500 J/KG OF ELEVATED CAPE...BUT WITH INCREASING DEEP-LAYER 0-6KM SHEAR NOW UP INTO THE 30-40KT RANGE. WOULD EXPECT A CONTINUED THREAT OF HAIL UP TO THE PENNY-ISH SIZE RANGE AS LONG AS THIS CONVECTION CONTINUES TO LINGER IN SOUTHEAST ZONES EARLY THIS MORNING. GETTING INTO THE OFFICIAL DAYTIME 12Z-00Z PERIOD...AT LEAST FOR NOW CONTINUED TO LINGER A SCATTERED SHOWER/STORM MENTION IN A HANDFUL OF FAR SOUTHEAST COUNTIES THROUGH 15Z...BUT ACCORDING TO REFLECTIVITY TRENDS FROM THE 06Z HRRR THIS IS PROBABLY BEING PLENTY GENEROUS...AS MOST CONVECTION SHOULD FINALLY BE OUT OF THE CWA BY SUNRISE OR SO. ONCE THIS ONGOING PESKY STRONG CONVECTION GETS OUT OF HERE...THE MAJORITY OF THE DAY SHOULD BE FAIRLY UNEVENTFUL AND DRY WITHIN THE CWA...WITH SKIES FOR MOST OF THE DAY AVERAGING NO WORSE THAN PARTLY CLOUDY IF NOT MOSTLY SUNNY. IT GOES WITHOUT SAYING THAT THOSE NOT PAYING ATTENTION THE LAST FEW DAYS WILL BE CAUGHT OFF GUARD BY THE 25-30 DEGREE DROP IN TEMPS FROM YESTERDAY. KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...BUT BASED ON EXPECTATION OF SOME SUN AND DECENT MIXING...ACTUALLY NUDGED UP MOST AREAS 1-2 DEGREES...BUT STILL KEEPING NEARLY ALL AREAS A FEW DEGREES EITHER SIDE OF 60. ALTHOUGH WINDS WILL REMAIN QUITE BREEZY THIS MORNING WITH GUSTS OF AT LEAST 25-30 MPH STILL COMMON...A STEADY DECREASING TREND WILL CONTINUE THROUGH THE DAY WITH SUSTAINED SPEEDS THIS AFTERNOON AVERAGING AROUND 15 MPH OR LOWER. TONIGHT...NORTH-NORTHEAST BREEZES OF NO MORE THAN 5-10 MPH WILL PREVAIL CWA-WIDE AS SURFACE HIGH PRESSURE SETTLES DEEPER INTO THE REGION. HOWEVER...CLOUD TRENDS WILL PROVE TRICKY...AS THE REGION COMES UNDER INCREASING UPPER LEVEL JET ENTRANCE REGION DYNAMICS AS A BROAD TROUGH CONTINUES SETTLING INTO THE CENTRAL/NORTHERN PLAINS. ALTHOUGH THE FORECAST FOR TONIGHT WAS LEFT VOID OF PRECIP MENTION...ISENTROPIC LIFT EVIDENT AROUND THE 700MB LEVEL SHOULD PROMOTE A STEADILY EXTENDING BAND OF MID LEVEL CLOUDS ACROSS MOST OF THE CWA ESPECIALLY AFTER MIDNIGHT...WITH THE BEST POTENTIAL FOR PRECIP REMAINING WEST OF THE CWA. HOWEVER...CERTAINLY CANNOT RULE OUT A FEW SPRINKLES LATE TONIGHT ESPECIALLY IN SOUTHERN ZONES BUT WILL KEEP EVEN THIS MENTION OUT FOR NOW. ALTHOUGH MET/MAV GUIDANCE CAME IN QUITE CHILLY FOR TONIGHTS LOWS...OPTED TO KEEP THE OFFICIAL FORECAST AT LEAST 3 DEGREES ABOVE THIS GUIDANCE CONSENSUS IN MOST AREAS TO ACCOUNT FOR EXPECTATION OF INCREASING CLOUDS THROUGH THE NIGHT. THIS YIELDED A SLIGHTLY WARMER LOW TEMP FORECAST THAN PREVIOUS...BUT STILL BRINGS MOST NEB ZONES INTO THE LOW-MID 30S...BUT RANGING FROM UPPER 20S FAR NORTH TO UPPER 30S IN MOST KS ZONES. ALTHOUGH A MARGINAL FREEZE AND/OR PATCHY FROST IS VERY POSSIBLE TONIGHT ACROSS MOST NEB ZONES...THE UNCERTAINTY IN HOW MUCH CLOUD COVER COULD HOLD THINGS UP...ALONG WITH THE FACT THAT THE NEXT FEW NIGHTS SHOULD BE EVEN COLDER...HAS KEPT ME FROM ISSUING A FORMAL FROST/FREEZE HEADLINE FOR TONIGHT AT THIS TIME. FRIDAY DAYTIME...SUBTLE SHORTWAVE ENERGY CONTINUES TO TRACK WEST- EAST ACROSS THE CWA UNDERNEATH ONE OF THE STRONGER...MOST PERSISTENT UPPER LEVEL JETS SEEN IN AWHILE. PERSISTENT MID LEVEL LIFT UNDERNEATH THIS JET CORE SHOULD KEEP PLENTY OF MID-HIGH CLOUDS AROUND DURING THE DAY. AS FOR RAIN CHANCES...CONVERTED ZONE FORECAST WORDING TO SLIGHT CHANCE OF LIGHT RAIN ACROSS MOST OF THE CWA...WITH THE OVERALL BEST RISK FOR POSSIBLY A FEW HUNDREDTHS TARGETING THE SOUTHWEST 1/2 OF THE AREA. IF THE LOW LEVEL THERMAL PROFILE SETS UP JUST RIGHT...SUPPOSE A FEW SNOWFLAKES ARE POSSIBLE DURING THE MORNING IN THE WEST AROUND THE DAWSON COUNTY AREA...BUT WITH LIGHT RAIN MORE LIKELY TO DOMINATE HAVE LEFT THIS AS THE ONLY PRECIP TYPE MENTION FOR NOW. FOR HIGH TEMPS NUDGED UP EASTERN ZONES VERY SLIGHTLY BUT OTHERWISE LITTLE CHANGE WITH HIGHS IN MOST AREAS ONLY LOW-MID 50S BUT MAYBE ONLY UPPER 40S IN PARTS OF THE WEST. FRIDAY NIGHT...A MID LEVEL SHORTWAVE OVER THE DAKOTAS WILL SINK SOUTH TOWARD THE REGION...AS FAST ZONAL FLOW CONTINUES IN THE UPPER LEVELS. LINGERED A SLIGHT CHANCE OF LIGHT RAIN IN FAR SOUTHERN/SOUTHWEST ZONES THROUGH THE NIGHT...BUT THE LATEST TRENDS HAVE BEEN FOR THE VAST MAJORITY OF THE CWA TO STAY DRY THROUGH THE NIGHT WITH THE MAIN FOCUS FOR RAIN OR A RAIN-SNOW MIX HOLDING JUST WEST OF THE CWA. AGAIN...CLOUD TRENDS WILL PROVE VERY TRICKY REGARDING HOW COLD IT GETS...AS EXPECT A GRADIENT RANGING FROM MORE CLEAR IN THE NORTHEAST TO MORE CLOUDY IN THE SOUTHWEST. SOME OF MET/MAV GUIDANCE CAME IN QUITE COLD...AND ALTHOUGH DID NOT GO QUITE AS LOW AS THIS GUIDANCE...DID LOWER LOWS A SOLID 2-5 DEGREE FROM PREVIOUS FORECAST...NOW PUTTING MOST AREAS NORTH OF HIGHWAY 6 DOWN IN THE 20S AND AREAS SOUTH INTO KS MAINLY LOW-MID 30S. AS A RESULT...UNLESS CLOUD WREAK HAVOC...MUCH OF THE NORTHERN 1/2 OF THE CWA SHOULD REALIZE ITS FIRST HARD FREEZE OF THE SEASON...WITH FREEZE HEADLINES A DECENT BET DURING THE NEXT FEW FORECAST CYCLES. SATURDAY DAYTIME...THE AFOREMENTIONED SHORTWAVE TO THE NORTH DROPS SOUTH OVER NEB...BUT WITH ANY APPRECIABLE FORCING FOR LIGHT PRECIP STILL ONLY SKIRTING THE FAR SOUTHWESTERN CWA...WHERE A SLIGHT CHANCE OF LIGHT RAIN WAS MAINTAINED. OTHERWISE...NUDGED UP HIGHS VERY SLIGHTLY MOST AREAS BASED ON LATEST GUIDANCE CONSENSUS...BUT WITH MOST AREAS ONLY LOW-MID 50S AND UPPER 40S SOUTHWEST. FINALLY FOR SATURDAY NIGHT...CONFIDENCE IS FAIRLY HIGH THAT IT WILL BE DRY CWA-WIDE...AND GENERALLY CLEARER THAN BOTH TONIGHT/FRIDAY NIGHT AS THE MAIN MID LEVEL WAVE DEPARTS SOUTHEAST TOWARD MO. FOR THOSE AREAS THAT DO NOT HARD-FREEZE FRIDAY NIGHT...SATURDAY NIGHT IS STILL EXPECTED TO PRETTY MUCH PUT THE NAIL IN THE COFFIN ON THE GROWING SEASON...WITH MOST IF NOT OF THE CWA SETTLING AT LEAST INTO THE MID-UPPER 20S. IF THINGS GO AS CURRENTLY ENVISIONED...FRIDAY NIGHT COULD FEATURE THE LAST FREEZE WARNING OF THE SEASON IN ROUGHLY THE NORTHERN 1/2 OF THE CWA...WITH THE SOUTHERN 1/2 LIKELY BEING FINISHED OFF SATURDAY NIGHT. AS ALREADY STATED SEVERAL TIMES THOUGH...MID LEVEL CLOUD TRENDS COULD POTENTIALLY THROW IN A WRENCH IN THESE PLANS HOWEVER...ESPECIALLY IF THEY HOLD UP LOWS HIGHER THAN EXPECTED FRIDAY NIGHT. LONG TERM...STARTING 12Z SUNDAY. LONG TERM GUIDANCE SUGGESTS NORTHWESTERLY TO QUASI-ZONAL MID AND UPPER LEVEL FLOW WILL PERSIST OVER THE CENTRAL PLAINS DURING THE LONG TERM FORECAST PERIOD. A PAIR OF MID LEVEL SHORTWAVES ARE ALSO EXPECTED TO PUSH ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY DURING THE LONG TERM FORECAST PERIOD...ONE DURING THE DAY MONDAY AND THE OTHER ON TUESDAY. BEFORE THE PASSAGE OF THESE MID LEVEL SHORTWAVES HOWEVER...SOUTHERLY LOW LEVEL FLOW AND RESULTANT WARM AIR ADVECTION SHOULD PRESENT A WARMING TREND BOTH SUNDAY AND MONDAY. THE INITIAL MID LEVEL SHORTWAVE ON MONDAY IS THEN EXPECTED TO PROMOTE SURFACE CYCLOGENESIS OVER SOUTHERN ONTARIO...WITH AN ASSOCIATED COLD FRONT EXPECTED TO SWEEP SOUTH/SOUTHEAST ACROSS THE CENTRAL PLAINS EARLY TUESDAY. THE SECOND MID LEVEL SHORTWAVE ON TUESDAY IS THEN EXPECTED TO PROVIDE A REINFORCING SHOT OF LOW LEVEL COLD AIR ADVECTION TO THE AREA TUESDAY NIGHT INTO WEDNESDAY MORNING WITH THE OPERATIONAL GFS...EC AND GEFS-MEAN ALL SUGGESTING A ~1025MB SURFACE HIGH WILL SET UP SHOP NEAR OR OVER OUR AREA BY 12Z WEDNESDAY. GIVEN ALL THIS...WENT AHEAD WITH A COOLING TREND IN TEMPERATURES TUESDAY AND WEDNESDAY. DESPITE THE PASSAGE OF THESE LOW LEVEL BAROCLINIC ZONES...OVERALL KINEMATIC FORCING APPEARS WEAK THROUGHOUT THE LONG TERM FORECAST. IN ADDITION...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE CWA PER THE OPERATIONAL GFS AND EC SUGGEST TROPOSPHERIC MOISTURE WILL BE FAIRLY LACKING DURING THIS SAME TIME PERIOD. GIVEN ALL THIS...THE LONG TERM FORECAST PERIOD REMAINS DRY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH AVIATION/LONG TERM...BRYANT
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
944 AM MDT THU OCT 4 2012 .UPDATE... LATEST OBS AND RUC13 GUIDANCE SHOW SURFACE PRESSURE RISES DECREASING OVER THE E PLAINS THEREFORE HAVE ALLOWED WIND ADV TO EXPIRE ON TIME FOR CURRY AND ROOSEVELT COUNTIES. NORTH TO NORTHEAST WINDS 20 TO 30 MPH WILL GRADUALLY DIMINISH AND VEER TO THE SOUTH AND SOUTHEAST AS THE DAY PROGRESSES. GUYER && .PREV DISCUSSION...554 AM MDT THU OCT 4 2012... .AVIATION... 12Z TAF CYCLE VFR CONDITIONS WILL PREVAIL DURING THE NEXT 24 HOURS. NWLY FLOW ALOFT WILL TRANSITION TO WLY EARLY THIS MORNING WITH CIRRUS SPREADING OVER THE REGION. STRONG COLD FRONT WILL CONTINUE TO PUSH SOUTH THROUGH SE NM THIS MORNING. AS ASSOCIATED SFC HIGH PRESSURE SLIDES E LATE THIS MORNING...N TO NELY SURFACE WINDS OVER THE E PLAINS WILL TRANSITION TO ELY...THEN SELY BY EARLY AFTERNOON. W OF THE CENTRAL MTNS...WEST WINDS WILL DEVELOP WITH GUST TO 25KTS POSSIBLE AROUND MID AFTERNOON...RAPIDLY DIMINISHING IN 23Z-01Z TIME-FRAME. 33 .PREV DISCUSSION...341 AM MDT THU OCT 4 2012... AT 00Z...A DRY ATMOSPHERE CONTINUED ACROSS THE AREA WITH THE KABQ UPPER AIR SOUNDING SHOWING A PWAT OF 0.37 INCH...OR ROUGHLY 80% OF NORMAL. AT 09Z...LATEST SURFACE OBS AND SATELLITE IMAGERY SHOWING EVIDENCE OF MOUNTAIN WAVE ACTION ACROSS CENTRAL AND WESTERN AREAS...WITH A COLD FRONT BARRELING DOWN THE EASTERN PLAINS. THE FRONT WAS LOCATED ALONG A CLOVIS TO SANTA ROSA TO NEAR LAS VEGAS LINE. BEHIND THE FRONT...NORTHERLY WINDS WERE GUSTING TO BETWEEN 40 AND 50 MPH. MUCH COOLER CONDITIONS ARE FORECAST TODAY ACROSS THE EASTERN PLAINS BEHIND THE FRONT...WITH HIGHS 15 TO 25 DEGREES BELOW WEDNESDAY`S AND GENERALLY 5 TO 10 DEGREES BELOW NORMAL. CONTRAST THIS WITH CENTRAL AND WESTERN PORTIONS OF THE AREA WHERE HIGHS WILL BE AN AVERAGE 10 DEGREES ABOVE NORMAL...ALTHOUGH NOT QUITE AS WARM AS YESTERDAY. THIS FRONT IS NOT FORECAST TO PUSH THROUGH THE CENTRAL MOUNTAIN CHAIN...INSTEAD BREEZY WESTERLY WINDS ARE EXPECTED TO MIX DOWN TO THE SURFACE CENTRAL AND WEST TODAY WITH THE FRONT RETREATING EASTWARD OVERNIGHT. ANOTHER DRY...BREEZY AND WARM DAY IS FORECAST FRIDAY WITH HIGHS ABOVE NORMAL EXCEPT FOR ACROSS THE NORTHEAST PLAINS WHERE THE FIRST FRONT WILL BE REINFORCED BY A SECOND...MORE SIGNIFICANT FRONT. THIS SECOND FRONT IS FORECAST TO PUSH DOWN THE EASTERN PLAINS FRIDAY NIGHT AND THEN WEST THROUGH THE CENTRAL MOUNTAIN CHAIN EARLY SATURDAY MORNING. THIS SECOND FRONT PRESENTS A COUPLE FORECAST CHALLENGES. THE FIRST CHALLENGE IS PRECIPITATION TYPE GIVEN STRONG COLD AIR ADVECTION AND UPSLOPE FLOW. 00Z MODEL FORECAST SOUNDINGS SUGGEST AREAS OF DRIZZLE OR VERY LIGHT RAIN ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN TO THE TEXAS BORDER...EXCEPT FOR PATCHY FREEZING DRIZZLE ACROSS THE NORTHEAST HIGHLANDS...JOHNSON MESA AND NORTHEAST PLAINS. MODEL QPF IS A FEW HUNDREDTHS OF AN INCH OR LESS. THERE DOES NOT APPEAR TO BE SUFFICIENT MOISTURE IN THE ICE GENERATION REGION OF THE ATMOSPHERE FOR SNOW OR SLEET TO BE MUCH OF A CONCERN. GIVEN VERY WARM TEMPERATURES OF THE PAST FEW DAYS...ANY FREEZING DRIZZLE THAT DEVELOPS LATE FRIDAY NIGHT INTO SATURDAY MORNING WILL LIKELY HAVE LITTLE IMPACT. THE SECOND FORECAST CHALLENGE IS WITH EAST CANYON/GAP WINDS ALONG THE RIO GRANDE VALLEY EARLY SATURDAY MORNING THROUGH SUNDAY. THE MODEL SOLUTIONS ALL SHOW AN IMPRESSIVE EAST TO WEST PRESSURE GRADIENT WITH GOOD RUN-TO-RUN CONSISTENCY. CONFIDENCE IS HIGH ON AN EAST WIND EVENT...BUT THE TIMING OF THE STRONGEST WINDS IS STILL UNCERTAIN. AT THIS TIME...THE STRONGEST WINDS APPEAR TO DEVELOP SATURDAY EVENING AND PERSIST THROUGH EARLY SUNDAY MORNING. A WIND ADVISORY MAY BECOME NECESSARY. TEMPERATURE WISE...A SIGNIFICANT COOL-DOWN IS FORECAST WITH THIS FRONT...WITH HIGH TEMPERATURES IN THE 40S AND 50S ACROSS THE EASTERN PLAINS SATURDAY. COOLER TEMPERATURES WILL SPREAD WEST BEHIND THE FRONT SATURDAY INTO SUNDAY WITH BELOW NORMAL TEMPERATURES FORECAST ACROSS MOST OF OUR AREA SUNDAY. TEMPERATURES WILL MODERATE EARLY NEXT WEEK WITH WARM AIR ADVECTION IN ADVANCE OF AN EASTWARD PROGRESSING UPPER LOW. THE 00Z ECMWF AND GFS SOLUTIONS ARE IN GOOD AGREEMENT WITH THIS FEATURE... POSITIONING IT NEAR SOCAL BY 12Z NEXT THURSDAY. PRECIP CHANCES WILL CREEP IN THE FORECAST AROUND MID WEEK...BUT THE BETTER CHANCES WILL LIKELY BE DELAYED UNTIL LATE WEEK WITH THE UPPER LOW ON SLOW APPROACH. 11 .FIRE WEATHER... SHALLOW BUT QUITE VIGOROUS BACK DOOR FRONT RACING SOUTH THROUGH THE FAR EASTERN PLAINS EARLY THIS MORNING. THIS FRONT IS NOT EXPECTED TO MAKE MUCH PROGRESS WEST OF THE CENTRAL HIGHLANDS. DRAMATIC COOLING HAS FOLLOWED THE FRONT PASSAGE FROM THE NORTHEAST PLAINS SOUTHWARD TO THE EAST-CENTRAL PLAINS WHERE TEMPERATURES HAVE ALREADY FALLEN 15 TO 20 DEGREES. THE SURFACE HIGH PRESSURE ASSOCIATED WITH THE FRONT IS EXPECTED TO SHIFT EAST FAIRLY QUICK AND SO WINDS WILL GRADUALLY BECOME SELY BY AFTERNOON. WEST OF THE CENTRAL HIGHLANDS...BREEZY TO LOCALLY WINDY CONDITIONS WILL DEVELOP ONCE AGAIN THIS AFTERNOON. THE WINDS WILL BE MORE WEST/SOUTHWEST. A STRONGER BACK DOOR COLD FRONT WILL PLOW THROUGH NORTHEAST NM FRIDAY NIGHT. MODELS CONTINUE IDEA OF A MODERATE WESTERLY WIND FLOW NEAR MOUNTAIN TOP LEVEL AGAIN FRIDAY....MAINLY OVER THE NORTHWEST THIRD. NOT MUCH CHANGE IS EXPECTED IN RELATIVE HUMIDITY VALUES OR VENTILATION...EXCEPT OVER THE FAR NORTHEAST WHERE THE FRONT WILL START TO BRING OM HIGHER RELATIVE HUMIDITY VALUES AND POOR VENTILATION IN THERE BY LATE AFTERNOON. THIS VIGOROUS FRONT IS EXPECTED TO BRING WIDESPREAD LOW CLOUDS...COLDER CONDITIONS...AND SOME DRIZZLE OR LIGHT RAIN TO THE EASTERN PLAINS AND EASTERN SLOPES OF THE CENTRAL MOUNTAINS SATURDAY MORNING AND AGAIN SATURDAY NIGHT/SUNDAY MORNING. HIGH TEMPERATURES WILL BE 20 TO 30 DEGREES BELOW AVERAGE EAST AND 5 TO 10 DEGREES BELOW AVERAGE FOR EARLY OCTOBER CENTRAL AND WEST. POOR VENTILATION RATES EAST AND FAIR WEST ARE ANTICIPATED FOR SATURDAY. TEMPERATURES SLOWLY MODIFY AND THE LOW CLOUDS EAST GRADUALLY DISSIPATE DURING THE DAY SUNDAY AS SURFACE HIGH PRESSURE OVER THE SOUTHERN PLAINS BEGINS TO SHIFT EAST AND SURFACE WINDS BECOME SOUTHERLY TO SOUTHEASTERLY. MEDIUM RANGE WEATHER PREDICTION MODELS CONTINUE WITH IDEA OF A CLOSED UPPER LOW DRIFTING SOUTH THROUGH CALIFORNIA EARLY NEXT WEEK...EVENTUALLY SETTLING THE UPPER LOW OVER THE LOWER COLORADO RIVER AROUND MIDWEEK. THE DEVIL IS ALWAYS IN THE DETAILS...HOWEVER...THE MODELS ARE AND HAVE BEEN REMARKABLY CONSISTENT FROM RUN TO RUN...TRENDING TOWARD AT LEAST AN UNSETTLED PATTER FOR THE LATTER HALF OF NEXT WEEK. 33 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1045 AM CDT THU OCT 4 2012 .UPDATE... WE HAVE UPDATED THE FORECAST TO INCREASE CLOUD COVER ALONG THE RIO GRANDE PLAINS AND EDWARDS PLATEAU THROUGH THE REMAINDER OF THIS MORNING. && .DISCUSSION... STRATUS CLOUDS CONTINUE TO HANG TOUGH ACROSS THE RIO GRANDE PLAINS AND EDWARDS PLATEAU THIS MORNING. THE LATEST RUC SUGGESTS CLOUDS WILL REMAIN INTACT THROUGH ROUGHLY NOON AND WE HAVE INCREASED CLOUD COVER OUT WEST. OTHERWISE...ONLY MINOR CHANGES HAVE BEEN MADE TO THE DEW POINTS AND WINDS BASED ON THE LATEST OBSERVATIONAL TRENDS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 92 69 91 66 73 / 0 - - - 10 AUSTIN BERGSTROM INTL AIRPORT 91 65 89 62 75 / 0 - - - 10 NEW BRAUNFELS MUNI AIRPORT 91 67 90 64 78 / 0 - - - - BURNET MUNI AIRPORT 88 68 88 61 67 / 0 - - 10 10 DEL RIO INTL AIRPORT 92 69 94 68 85 / 0 - 0 0 - GEORGETOWN MUNI AIRPORT 89 66 89 64 68 / 0 - - 10 10 HONDO MUNI AIRPORT 92 67 91 62 82 / 0 - - - - SAN MARCOS MUNI AIRPORT 91 66 90 63 76 / 0 - - - - LA GRANGE - FAYETTE REGIONAL 90 65 90 65 80 / 0 - - - 10 SAN ANTONIO INTL AIRPORT 91 69 89 65 79 / 0 - - - - STINSON MUNI AIRPORT 92 69 90 66 81 / 0 - - - - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...24 PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1049 AM CDT THU OCT 4 2012 .UPDATE...INTERESTING SITUATION LAID FORTH WITH A STRONG COLD FRONT CURRENTLY MOVING THROUGH SOUTH CENTRAL AND SOUTHEAST WISCONSIN...AND FASTER THAN ANTICIPATED. AT 10Z...FRONT IS NEAR A LINE FROM SOUTH WAYNE...TO MARXVILLE... TO GLEN OAK. FRONT IS EXPECTED TO REACH MADISON AROUND 11 AM AND MILWAUKEE BETWEEN 2 AND 3 PM. RADAR SHOWS A LINE OF SHOWERS JUST A BIT BEHIND THE FRONT...CURRENTLY JUST ALONG THE WESTERN BORDER OF THE CWAS SW CORNER. SCATTERED SHOWERS ARE BEHIND THIS LINE IN EASTERN IOWA AS WELL. AS SUCH...IN THIS UPDATE SKIES...WX...TEMP...AND WIND GRIDS WERE ADJUSTED GIVEN THE FRONTS SPEED. HRRR HAS BEEN SHOWING GOOD AGREEMENT IN REGARD TO WIND FIELDS AND REFLECTIVITY EARLY ON. AS SUCH...HAVE BEEN LEANING TOWARDS THE HRRR FOR WX AND POPS FOR TIMING PURPOSES ALONG WITH CURRENT RADAR TRENDS. STILL ANTICIPATE SCATTERED RAIN SHOWERS LATE MORNING INTO THE AFTERNOON. TEMPS WILL STILL BE TRICKY GIVEN HOW FAST THEY ARE INCREASING IN THE SOUTHEAST. AT 1045 AM IN THE WFO SULLIVAN OFFICE...THEY ARE ALREADY UP TO 70 F...WITH THE REST OF FAR SOUTHEAST WI MAINLY IN THE MID 60S. HIGH TEMPERATURES WILL HAVE A STRONG GRADIENT WITH THE FRONT ALREADY TRACKING EAST INTO THE CWA. THUS...FCST TRENDS WERE ADJUSTED GIVEN THIS AND THEY WILL BE MONITORED CLOSELY. && .AVIATION/18Z TAFS/...COLD FRONT NOW WORKING INTO THE WESTERN FORECAST AREA. TIMING OF FRONT AND POSSIBLE SHOWERS IN TAFS STILL SEEMS REASONABLE. WILL KEEP AN EYE ON WIND AND PRECIP TRENDS AND UPDATE OR ADD MORE DETAIL TO TAFS AS NEEDED. CIGS SHOULD STAY MAINLY VFR...THOUGH MVFR VSBYS POSSIBLE WITHIN ANY MODERATE SHOWERS THAT DEVELOP. STILL A POSSIBILITY FOR SOME THUNDER THIS AFTERNOON...PARTICULARLY IN THE EAST WHERE MORE HEATING WILL OCCUR. SHOULD SEE SKIES CLEAR OUT THIS EVENING BEHIND THE FRONT...WITH BREEZY BUT OTHERWISE QUIET WEATHER EXPECTED OVERNIGHT AND FRIDAY. && .PREV DISCUSSION... /ISSUED 341 AM CDT THU OCT 4 2012/ SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE - MEDIUM. CLEARING MID CLOUDS AND RECENT -SHRA WL RESULT IN PATCHY DENSE FOG IN SOME EASTERN AREAS NEXT FEW HOURS. HOWEVER INCREASING BOUNDARY LAYER MIXING SHOULD PREVENT DENSE FOG FROM BECOMING WIDESPREAD. SHORT TERM GUIDANCE IN GOOD AGREEMENT ON DEEPENING LOW PRESSURE OVER CENTRAL MN MOVING NORTHEAST AND DRAGGING STRONG CDFNT ACROSS SRN WI LATER THIS MRNG THRU MID-AFTN. INCREASING SOUTHWEST WINDS AHEAD OF THE FRONT WL CARRY INCREASING MID-LEVEL MOISTURE FROM CENTRAL PLAINS INTO SRN WI LATE THIS MRNG AND AFTN AS COLUMN PRECIPITABLE WATER VALUES BRIEFLY REACHES 1.0 AHEAD OF CDFNT. SFC DEWPTS IN THE UPPER 40S TO LWR 50S WL RESULT IN WEAK INSTABILITY AHEAD OF THE FRONT...WITH MUCAPES POSSIBLY REACHING 100 J/KG. STRONG DYNAMICS ASSOCD WITH THIS SYSTEM AND LOW LEVEL FRONTOGENETICAL FORCING ALONG FRONT SHOULD RESULT IN SCT SHRA LATER THIS MRNG IN THE WEST...SPREADING INTO THE EAST THIS AFTN...WITH ISOLD T. RAPID MOVEMENT OF FRONT WL RESULT IN BRIEF 1-2 HOUR PERIOD OF POSSIBLE PRECIPITATION BEFORE DRIER...COLD AIR SWEEPS IN BEHIND FRONT. LOW LEVEL MIXING MAY ALLOW WIND GUSTS OF 30 TO 35 KTS FOR SEVERAL HOURS IN ERN AREAS BEFORE CLOUDS INCREASE. EXPECT LARGE GRADIENT IN MAX TEMP ACROSS CWA TODAY...CLOSING IN ON 80 IN SOME FAR SOUTHEAST LOCATIONS AND STAYING IN THE 60S IN THE WEST. COLD AIR SWEEPS IN TNGT...DROPPING ALL AREAS INTO THE 30S. NORTHWEST BREEZES SHOULD PREVENT FROST FORMATION. WL NEED TO KEEP EYE ON EXPANDING COLD AIR STRATUS OVER SW MN/NW IA. SHORT TERM MODELS NOT HANDLING THIS WELL. FOR NOW WL CONTINUE WITH MORE OPTIMISTIC CLEARING FOR LATER THIS AFTN AND TNGT. FRIDAY...FORECAST CONFIDENCE HIGH. THE CLOSED UPPER LOW JUST NORTH OF LAKE SUPERIOR ON FRIDAY WILL WEAKEN AND SHIFT EASTWARD FRIDAY NIGHT. DESPITE THE MODELS SLOWING THE SOUTHERLY PROGRESSION OF THE BAROCLINIC ZONE...EXPECT ANY ASSOCIATED PRECIP TO REMAIN SOUTH OF THE WI BORDER ON FRIDAY. RAIN AND SNOW SHOWERS IN THE WRAPAROUND REGION OF THE DEPARTING LOW WILL BE CONFINED WELL TO OUR NORTH...SO DRY FORECAST ON FRIDAY. VERY DRY AIR SHOULD INHIBIT LOW LEVEL DIURNAL CU...BUT THERE COULD BE A FEW MID CLOUDS STREAMING OVERHEAD. 925MB TEMPS SHOULD REMAIN FAIRLY STEADY AT 4 TO 5C ON FRIDAY...SO MAX TEMPS IN LOWER 50S. STEEP LAPSE RATES AND TIGHT SURFACE PRESSURE GRADIENT WILL LEAD TO DEEP MIXING AND GUSTY WEST WINDS UP TO 25 KNOTS. FRIDAY NIGHT THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE...MEDIUM. THE SURFACE HIGH WILL MOVE INTO THE CENTRAL PLAINS SAT AND SAT NIGHT. LINGERING TIGHT PRESSURE GRADIENT OVER WI FRIDAY NIGHT SHOULD KEEP SFC A LITTLE MIXED...THUS LIMITING FROST POTENTIAL. MIN TEMPS EXPECTED AROUND 30...SO FREEZE HEADLINES MAY BE NECESSARY. ANOTHER UPPER TROUGH WILL SWING DOWN ACROSS WI FRIDAY NIGHT...LEADING TO EVEN COOLER TEMPS ON SATURDAY. SATURDAY HIGHS WILL STRUGGLE TO REACH 50 WITH PLENTY OF CLOUDS AROUND. SATURDAY NIGHT STILL LOOKS COLDEST WITH MIN TEMPS IN THE UPPER 20S INLAND FROM THE LAKESHORE. WIDESPREAD FROST EXPECTED. FREEZE HEADLINES LIKELY. LONG TERM... SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...MEDIUM. ONE MORE SHORTWAVE IS EXPECTED TO MOVE ACROSS THE BASE OF THE LARGE SCALE UPPER TROUGH SUNDAY AFTERNOON AND NIGHT BEFORE IT FINALLY PUSHES EAST. THE LARGE SURFACE HIGH WILL MOVE ACROSS THE OHIO VALLEY ON MONDAY WITH AN AREA WITH WARM AIR ADVECTION SPREADING INTO SOUTHERN WI ONCE AGAIN. TEMPS SHOULD BE IN THE UPPER 50S TO LOWER 60S FOR MON AND TUE...AND THEN DROP BACK INTO THE LOWER 50S FOR WED BEHIND ANOTHER SURFACE TROUGH/COLD FRONT. PRECIP CHANCES LOOK VERY SMALL. AVIATION/12Z TAFS/...CLEARING MID-LEVEL CLOUDS AND AREAS OF -RA EARLIER SHOULD RESULT IN PATCHY DENSE FOG FOR A TIME IN PARTS OF THE FAR EASTERN CWA EARLY THIS MRNG. OTRW...INCREASING BOUNDARY LAYER MIXING WL PREVENT SIGNIFICANT FOG. EXPECT STRONG COLD FRONT TO SWEEP ACROSS SRN WI 15Z-22Z WITH SCT SHRA AND ISOLD TSTRMS IN ITS VICINITY. WIND GUSTS MAY BRIEFLY REACH 30-35 KTS EARLY THIS AFTN IN STRONG LOW LEVEL MIXING JUST AHEAD OF SFC FRONT AT ERN TAF SITES. AT THIS TIME...EXPC VFR CONDITIONS FOR MOST OF THE TAF PERIOD AS STRATUS ASSOCD WITH COLD AIR ADVECTION LIKELY TO REMAIN NORTHWEST OF AREA...BUT WL NEED TO KEEP EYE ON ST SHIELD ADVANCING INTO NORTHWEST IA AND SRN MN FOR LATER TODAY AND TNGT. MARINE...STRONG LOW PRESSURE SYSTEM OVER CENTRAL MN WILL TRACK NORTHEAST AND DRAG A STRONG COLD FRONT ACROSS LAKE MI THIS AFTN. TIGHTENING PRESSURE GRADIENT AHEAD OF APPROACHING FRONT WILL CAUSE WIND GUSTS TO SMALL CRAFT ADVISORY LEVELS THIS AFTN. TSTORMS EXPECTED AS THE FRONT PASSES BY AS WELL. STRONGEST WIND GUSTS EXPECTED IN WAKE OF FRONT TONIGHT INTO FRIDAY AS STRONG LOW LEVEL COLD AIR SWEEPS ACROSS RELATIVELY MILDER LAKE MI WATERS. THIS WILL CREATE STEEP LOW LEVEL LAPSE RATES WHICH WILL ALLOW GUSTY WEST TO NORTHWEST WINDS TO MIX DOWN TO THE LAKE SURFACE. STRONGEST WINDS WILL BE FARTHER AWAY FROM SHORE WHERE GUSTS MAY REACH 30-33 KNOTS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT FRIDAY FOR LMZ643>646. && $$ UPDATE...ET/DDV TODAY/TONIGHT AND AVIATION/MARINE...MBK FRIDAY THROUGH WEDNESDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
611 AM CDT THU OCT 4 2012 .SHORT TERM...TODAY THROUGH SATURDAY 300 AM CDT THU OCT 4 2012 MAIN FORECAST CHALLENGE WILL BE A STRONG COLD FRONTAL PASSAGE TODAY ALONG WITH SHOWER/ISOLATED THUNDER CHANCES...THEN GUSTY POST FRONTAL WINDS. CONCERNS BEYOND THIS INCLUDE WELL BELOW NORMAL TEMPERATURES INTO THE WEEKEND WITH A HARD FREEZE EXPECTED SATURDAY NIGHT/SUNDAY MORNING. LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS A POTENT/DEEPENING TROUGH MOVING EAST ACROSS THE DAKOTAS WITH A 90-95KT 300MB JET ENTERING THE BASE OF THE TROUGH OVER SD. AT THE SURFACE...DEEP OCCLUDING LOW WAS LOCATED OVER WEST CENTRAL MN WITH A COLD FRONT EXTENDING SOUTHWARD INTO WESTERN IA. RADAR MOSAIC/SURFACE OBSERVATIONS SHOWING ELEVATED SHOWER/ISOLATED THUNDER ACTIVITY ACROSS EASTERN NEB WITH EXPANSIVE DEFORMATION RAIN/SNOW ACROSS THE EASTERN DAKOTAS/NORTHWEST MN. OTHERWISE...ACROSS THE LOCAL FORECAST AREA...IR IMAGERY SHOWING A FEW MID/HIGH CLOUDS. 04.00Z MODELS SHOWING GOOD AGREEMENT THROUGH THE SHORT TERM. FOR TODAY...AS THE LOW CONTINUES TO DEEPEN AND MOVE NORTH TO ALONG THE MN/CANADIAN BORDER THIS MORNING...EXPECTING THE COLD FRONTAL PASSAGE ALONG THE MISSISSIPPI RIVER BY 15Z AND THEN EXITING EAST OF THE AREA AROUND NOON. NAM AND HRRR WRF SHOWING SCATTERED PRECIPITATION ALONG A POST FRONTAL TROUGH MOVING INTO THE AREA THIS MORNING...MAINLY ACROSS NORTHEAST IOWA INTO SOUTHERN WI. NAM DEPICTING 200-400J/KG 1-7KM MUCAPE...SO KEPT MENTION OF ISOLATED THUNDER IN AS WELL. APPEARS RAIN CHANCES MAINLY CONFINED TO THIS MORNING THEN PUSHING EAST AFTER NOON. OTHERWISE...BIGGER STORY WILL BE GUSTY WEST WINDS OVERTAKING THE AREA BEHIND THE COLD FRONT AS DRY SLOT/COLD AIR ADVECTION NOSES IN. SUSTAINED WINDS EXPECTED TO BE IN THE 15-20 MPH RANGE WITH GUSTS HITTING AROUND 30-35 MPH. LOOK FOR HIGHS IN THE 50S TO MIDDLE 60S...SOME 15-20 DEGREES COOLER THAN HIGHS ON WEDNESDAY. FOR TONIGHT...THE DRY SLOT WILL KEEP SKIES MOSTLY CLEAR OVERNIGHT AS THE LOW BEGINS TO FILL AS IT MOVES NORTHEAST INTO ONTARIO CANADA. A FAIRLY TIGHT PRESSURE GRADIENT IS EXPECTED TO KEEP WINDS UP OVERNIGHT IN THE 15 TO 25 MPH RANGE. COLD AIR ADVECTION WILL CONTINUE AS 925MB TEMPERATURES FALL INTO NEGATIVE TERRITORY //ZERO TO MINUS 2C. THIS SHOULD PRODUCE OVERNIGHT RIGHT AROUND THE FREEZING MARK WITH WINDS CHILL IN THE 20-25 DEGREE RANGE THROUGH THE EARLY MORNING HOURS OF FRIDAY. FOR THE REST OF FRIDAY...ANOTHER BLUSTERY COLD DAY WILL BE ON TAP. DESPITE PARTLY TO MOSTLY SUNNY SKIES HIGHS WILL ONLY MAKE IT INTO THE MIDDLE 40S TO LOWER 50S ALONG WITH WEST/NORTHWEST WINDS OF 15-30 MPH. FOR FRIDAY NIGHT INTO SATURDAY...A SECONDARY MID-LEVEL TROUGH WILL DROP SOUTHEAST ACROSS THE AREA FOR A CHANCE OF MIXED RAIN AND SNOW SHOWERS. APPEARS MOST OF THIS ACTIVITY WILL REMAIN NORTHEAST OF I-94 IN BETTER PV-ADVECTION/COLDER AIR ALOFT. TEMPERATURES EXPECTED TO DIP TO AROUND THE 30 DEGREE MARK FRIDAY NIGHT AND ONLY MAKING IT INTO THE 40S ON SATURDAY...WHICH IS MORE TYPICAL FOR MID-NOVEMBER. SATURDAY NIGHT EXPECTED TO SEE A HARD FREEZE AS LOWS TUMBLE INTO THE LOWER AND MIDDLE 20S UNDER MOSTLY CLEAR SKIES AS A SURFACE RIDGE AXIS MOVES OVERHEAD. COULD SEE SOME RECORD LOWS BEING TIED OR BROKEN. FOR EXAMPLE...CURRENT FORECAST LOW FOR LA CROSSE IS 26 AND THIS WOULD TIE THE RECORD SET IN 2001. THIS WILL ALSO LIKELY MARK A FINAL END TO THE GROWING SEASON FOR AREAS THAT HAVE NOT YET SEEN A HARD FREEZE...THIS BEING AREAS ALONG THE MISSISSIPPI/WISCONSIN RIVER VALLEYS. FREEZE HEADLINES MAY EVENTUALLY BE NEEDED TO HIGHLIGHT THIS. .LONG TERM...SUNDAY THROUGH WEDNESDAY 300 AM CDT THU OCT 4 2012 04.00Z GFS/ECMWF IN OVERALL GOOD AGREEMENT WITH SYNOPTIC PATTERN THROUGH THE EXTENDED PERIOD. SUNDAY WILL SEE SOME SLIGHT MODERATION IN TEMPERATURES AS THE RIDGE AXIS SLIPS SOUTH...SETTING UP SOUTHWEST WINDS BACK INTO THE REGION. UNDER MOSTLY SUNNY SKIES...LOOK FOR HIGHS IN THE 40S TO LOWER 50S. MODELS CONSISTENT WITH BRING A LOW FROM ALBERTA CANADA INTO ONTARIO ON MONDAY. INCREASING SOUTHWEST FLOW IN THE WARM SECTOR OF THE LOW EXPECTED TO YIELD HIGHS IN THE MIDDLE 50S TO LOWER 60S. COLD FRONT FROM THIS LOW WILL THEN SWING SOUTHEAST ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY BRINGING WITH IT A CHANCE OF RAIN SHOWERS. WEDNESDAY LOOKS DRY WITH HIGHS IN THE 50S AS HIGH PRESSURE BUILDS OVERHEAD. && .AVIATION...TODAY AND TONIGHT 611 AM CDT THU OCT 4 2012 THE COLD FRONT IS MAKING STEADY EASTWARD PROGRESS AND SHOULD BE THROUGH KRST BY 12Z AND EXPECTED THROUGH KLSE BY 14Z. ONCE THE FRONT GOES THROUGH...THE WINDS WILL SWING AROUND TO THE WEST AND INCREASE TO SUSTAINED SPEEDS OF 10 TO 15 KNOTS WITH GUSTS AROUND 20 KNOTS. THESE SPEEDS WILL INCREASE AT BOTH SITES FOR THE LATE MORNING AND AFTERNOON AS THE GRADIENT TIGHTENS AND COLD AIR ADVECTION BEHIND THE FRONT PRODUCES STRONG SUBSIDENCE. LOOK FOR THE SUSTAINED SPEEDS TO BE AROUND 20 KNOTS WITH GUSTS OF 25 TO 30 KNOTS. THE SPEEDS WILL DIMINISH AROUND SUNSET BUT EXPECT SOME GUSTS TO CONTINUE AT KRST THROUGH A GOOD SHARE OF THE NIGHT. UPSTREAM OBSERVATIONS SHOW A MVFR DECK FOLLOWS AN HOUR OR TWO BEHIND THE FRONT AND THIS IS EXPECTED TO AFFECT BOTH TAF SITES ALONG WITH THE POSSIBILITY OF A SHOWER. THIS DECK SHOULD THEN BREAK UP DURING THE EARLY TO MID AFTERNOON WITH THE INCREASE IN SUBSIDENCE WITH VFR CONDITIONS THEN EXPECTED FOR THE REMAINDER OF THE PERIOD. && .ARX WATCHES/WARNINGS/ADVISORIES... 300 AM CDT THU OCT 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...04
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1242 PM MDT THU OCT 4 2012 .UPDATE... && .SHORT TERM...STRATUS STILL SLOW TO ERODE ALONG URBAN CORRIDOR AND MAY TAKE A FEW MORE HOURS TO DISSIPATE. AS A RESULT...TEMPERATURES HAVE BEEN SLOW TO WARM AND CURRENT HIGHS ACROSS MUCH OF PLAINS LOOK A BIT TOO WARM AND LOWERED TEMPS MOST AREAS A FEW DEGREES. NO OTHER CHANGES NEEDED AT THIS TIME. .PREV DISCUSSION... /ISSUED 905 AM MDT THU OCT 4 2012/ UPDATE... SHORT TERM...TEMPERATURES ACROSS PLAINS CURRENTLY IN THE MIDDLE 30S MOST AREAS. HAVE ENDED FREEZE WARNING. SATELLITE AND OBSERVATIONS STILL SHOWING STRATUS HANGING TOUGH ACROSS ALONG URBAN CORRIDOR AND ADJACENT PLAINS...THOUGH SOME ERRODING ALONG PALMER DIVIDE. MAY NEED TO MAKE SOME ADJUSTMENTS TO CLOUD COVER GRIDS THIS AM. OVERALL...CURRENT FORECAST TRENDS ON TRACK WITH ONLY MINOR ADJUSTMENTS AT THIS TIME. && .AVIATION...STRATUS HANGING ON A BIT LONGER THAT PREVIOUSLY THOUGHT...SO WILL CONTINUE THE BKN-OVC AT KDEN AND KAPA THROUGH 17Z. BOTH HRRR AND RUC INDICATING STRATUS SHOULD BE DISSIPATING AT THAT TIME. REST OF TAF TRENDS LOOK ON TRACK. .PREV DISCUSSION... /ISSUED 416 AM MDT THU OCT 4 2012/ SHORT TERM...COLD FRONT BLASTED THROUGH NORTHEAST COLORADO YESTERDAY AFTERNOON AND EARLY EVENING. MUCH COLDER AIR HAS MOVED OVER NORTHEAST COLORADO WITH TEMPERATURES RUNNING 40 TO 50 DEGREES COOLER THAN 12 HOURS AGO. THE COLD AIR WILL REMAIN OVER NORTHEAST COLORADO TODAY AS A LARGE SURFACE HIGH MOVES OVER THE NORTHERN AND CENTRAL ROCKIES. THIS WILL KEEP TEMPERATURES COOL TODAY WITH EXPECTED HIGHS IN THE LOWER 50S. THE COLD AIRMASS DID NOT MAKE IT OVER THE CONTINENTAL DIVIDE...SO AREAS WEST OF THE DIVIDE WILL SEE A MILD DAY TODAY. THE LOW CLOUDS ALONG THE FRONT RANGE WILL SLOWLY DISSIPATE THIS MORNING. WILL SEE MID AND HIGH CLOUDS TODAY AHEAD OF THE NEXT UPPER LEVEL TROUGH WHICH WILL DROP SOUTH OVER THEN NORTHERN ROCKIES. CLOUDS WILL INCREASE TONIGHT AS THIS TROUGH NEARS THE CENTRAL ROCKIES. LOW WILL BE CHILLY TONIGHT...BUT ARE EXPECTED TO REMAIN JUST ABOVE FREEZING DUE TO THE CLOUDS OVERHEAD. ONLY A SLIGHT CHANCE FOR A FEW WEAK RAIN OR SNOW SHOWERS THIS AFTERNOON AND EVENING OVER THE HIGHER TERRAIN SOUTH OF INTERSTATE 70. LONG TERM...UPSLOPE FLOW PERSISTS ON THE PLAINS FRIDAY EVEN AS THE FLOW ALOFT BECOMES ZONAL ON THE UNDER SIDE OF A SOUTHWARD DIGGING UPPER TROUGH. THIS EASTERLY LOW-LEVEL FLOW SHOULD KEEP TEMPERATURES UNSEASONABLY COOL THROUGHOUT THE DAY WITH 850 MB TEMPERATURES RANGING FROM AROUND 6C ALONG THE BASE OF THE FOOTHILLS TO NEAR 0C IN THE DEEPER COLD AIR OUT NEAR THE NORTHEAST CORNER OF THE STATE. MODELS SHOW THE LEFT EXIT QUAD OF A 110KT JET PASSING OVER NERN COLORADO LATE IN THE DAY WHICH PROVIDED ADDITIONAL LIFT FOR THE PRODUCTION OF SHOWERY PRECIP ACROSS THE NORTHEAST CORNER OF THE STATE. THIS GENERALLY LIGHT PRECIP WOULD EITHER BE SNOW OR A MIX OF RAIN AND SNOW WITH SUB-CLOUD TEMPERATURES JUST ABOVE FREEZING. CLOSER TO THE FRONT RANGE... PRECIP ON FRIDAY WILL MOST LIKELY BE VERY LIGHT AND SPOTTY IN COVERAGE WITH WEAK SUBSIDENCE ALOFT. FRIDAY NIGHT..PRECIP CHANCES ARE EXPECTED TO INCREASE EAST OF THE MTNS AND ESPECIALLY OUT ACRS THE NORTHEAST CORNER OF THE STATE WITH INCREASING QG ASCENT IN ON THE BACK SIDE OF THE PASSING JET. HAVE INTRODUCED A WIDE SWATH OF 50 PCT POPS ACROSS WELD...MORGAN...LOGAN...PHILLIPS AND LINCOLN COUNTIES WHERE WE HAVE A POTENTIAL FOR LIGHT SNOW ACCUMULATION BY MORNING. WE/RE TALKING ABOUT AN INCH OR TWO OF SNOW ON GRASSY SURFACES. COULD JUST AS EASILY GONE WITH LIKELY POPS OUT THAT WAY...BUT THE TIMING OF THIS PRECIP STILL REMAINS IN DOUBT. ON SATURDAY...SFC TEMPERATURES REMAIN QUITE COOL WITH A REINFORCING SURGE OF COLD AIR OVERNIGHT. 850MB TEMPERATURES PROGGED FOR THE PLAINS ARE BARELY ABOVE 0C DURING THE DAY. WENT AHEAD AND LOWERED HIGH TEMPS BY A FEW DEGS IN AREAS EAST OF THE MTNS. MEANWHILE... AREAS WEST OF THE CONTINENTAL DIVIDE SHOULD FEEL LITTLE IMPACT FROM THIS GREAT PLAINS COLD AIR MASS. POPS ON THE WEST SLOPE NEAR ZERO FOR THE MOST PART. THROUGH THE DAY SHOULD SEE PRECIP SHIFTING SOUTH AND EAST AS THE JET AND ITS ACCOMPANYING LIFT ALSO SHIFTS SOUTHEASTWARD. THE NAM IS INDICATING LIGHT SNOW ACCUMULATION ACROSS WASHINGTON AND LINCOLN COUNTIES SATURDAY MORNING...POSSIBLY AS MUCH AS A COUPLE INCHES BY MIDDAY. ELSEWHERE THE CHANCE FOR ACCUMULATING SNOWFALL SHOULD QUICKLY DIMINISH AS SOMEWHAT DRIER AIR BEGINS ADVECTING IN FROM WYOMING. SUNDAY AND BEYOND...THE COLD AIR FLUSHES OUT STARTING SUNDAY... WITH TEMPERATURES RETURNING TO NEAR AVERAGE BY MID-WEEK AS A SHORTWAVE UPPER RIDGE BUILDS OVER THE REGION. AVIATION...LOW CLOUDS WITH CEILING HEIGHTS OF 3000 TO 5000 FEET WILL DISSIPATE THIS MORNING. A SURFACE HIGH CENTERED NORTH OF COLORADO WILL KEEP EASTERLY UPSLOPE WINDS OVER THE AREA TODAY. THIS MAY HELP LOW CLOUDS PERSIST ALONG THE FOOTHILLS THROUGH LATE MORNING. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....BAKER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
445 PM EDT THU OCT 4 2012 .SYNOPSIS... RAIN WILL SWEEP ACROSS THE REGION TONIGHT. IN ITS WAKE FOG IS EXPECTED TO DEVELOP WITH VISIBILITIES DOWN TO A QUARTER MILE OR LESS. WARM AND DRY WEATHER FOLLOWS FOR FRIDAY INTO FRIDAY NIGHT. ANOTHER COLD FRONT WILL BRING A CHANCE OF SHOWERS SATURDAY...THEN A PERIOD OF CHILLY RAIN IS EXPECTED SUNDAY AFTERNOON INTO SUN NIGHT AS LOW PRESSURE MOVES UP THE COAST. DRIER WEATHER IS EXPECTED EARLY NEXT WEEK BUT WILL BE ACCOMPANIED BY COOLER THAN NORMAL TEMPERATURES. DRY AND COOL WEATHER IS EXPECTED MUCH OF NEXT WEEK FOLLOWED BY THE CHANCE OF SHOWERS MID WEEK AS AN EARLY SEASON CLIPPER LOW MOVES ACROSS THE REGION. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS IT LIFTS OUT OF THE RGN...THE BAROCLINIC TROF WITH ATTENDANT SHRTWV ENERGY DEAMPLIFIES IN RESPONSE TO RIDGING AHEAD OF A DEEPER CYCLONIC SYSTEM EJECTING INTO THE NRN TIER OF THE CONUS. THE APPROACHING SFC COLD FRNT SHOULD BECOME DIFFUSE AS SHOWERS COME TO AN END. EXPECTING THE BETTER RGN OF SHOWERS TO PREVAIL NEWD THRU CENTRAL AND NRN NEW ENGLAND PARENT WITH THE BETTER DYNAMICS TRANSLATING INTO THE ST LAWRENCE RVR VLY. SOME UNCERTAINTY AS TO THE LINE OVER THE HUDSON VLY RGN...WRF MDL SOLNS SUGGEST A GRADUAL TURNING TO DUE EAST. WHILE NOT TOTALLY ON BOARD WITH THIS SOLN AS IT/LL BE INTERESTING THE OUTCOME OF THE LINE AS IT MOVES E OF THE BERKSHIRES INTO A LESS FAVORABLE AIRMASS PER 12Z CHATHAM SOUNDING. WILL USHER LIKELY POPS...BUT ANTICIPATE THE STRENGTH OF THE LINE TO DIMINISH WITH EWD PROGRESSION /FOLLOWING THE 16Z HRRR CLOSELY/. SUBSIDENCE TO THE REAR COUPLED WITH HIGH PRES SHOULD ALLOW CONDITIONS TO GRADUALLY CLEAR AND IMPROVE...YET ABUNDANT REMNANT MOISTURE SHOULD REMAIN. THOUGH SKIES ARE EXPECTED TO CLEAR...WITH WEAK FLOW TOWARDS FRIDAY MORNING...WIDESPREAD FOG SHOULD DEVELOP ACROSS THE RGN AS SFC TEMPS FALL CLOSE TO OR AT THE DWPT /MINS AROUND THE MID 50S/. ANTICIPATING VSBYS DOWN TO ONE QUARTER OF A MILE OR LESS IN AREAS. DENSE FOG ADVISORIES APPEARING LIKELY. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FRIDAY... FOG WILL GRADUALLY BURN OFF INTO THE LATE MORNING PD. AREAS OF DENSE FOG ARE LIKELY TO IMPACT THE MORNING COMMUTE. ANTICIPATING MOSTLY CLEAR CONDITIONS WITH INCREASING CLOUDS LATE. DEEP MIXING OF THE BOUNDARY LYR SHOULD PREVAIL UP TO H85 INTO THE AFTN PD WHERE TEMPS RANGE FROM 10-12C. MAX TEMPS INTO THE LOW 80S IS CERTAINLY PLAUSIBLE UNDER LIGHT W/SWLY FLOW. FCST GUIDANCE IN CONSENSUS OF KEEPING THE PD DRY. FRIDAY NIGHT... WILL KEEP THE PD DRY AS THE BETTER FORCING LIES ACROSS THE ERN GRT LKS RGN AND SRN NEW ENGLAND REMAINS UNDER THE INFLUENCE OF STRONG HIGH PRES. W/SWLY FLOW PREVAILS USHERING A REBOUND OF SFC MOISTURE FROM DRIER CONDITIONS ON FRIDAY...DWPTS INCREASING INTO AND AROUND THE LOW 60S. THERE IS THE POTENTIAL FOR A RETURN OF LOW CLOUDS OR FOG INTO THE SAT MORNING PD /THE BETTER CHCS FOR FOG ALONG THE SRN SHORELINE OF NEW ENGLAND/. A MILD NGT WITH LOWS DOWN INTO THE MID- UPR 50S /LOW 60S PSBL ALONG THE S COASTLINE/. && .LONG TERM /SATURDAY THROUGH THURSDAY/... * CHANCE OF SHOWERS SATURDAY BUT STILL WARM AND BREEZY COASTAL PLAIN * CHILLY RAIN SUNDAY AFTERNOON INTO SUN NIGHT * DRY AND COOL WEATHER RETURNS EARLY NEXT WEEK OVERVIEW... MODELS ARE IN GOOD AGREEMENT ON GENERAL PATTERN THROUGH EARLY NEXT WEEK. STRONG RIDGING EXTENDING NORTH FROM OFF THE WEST COAST OF CANADA WILL PROMOTE BROAD DOWNSTREAM LONGWAVE TROF OVER THE GT LAKES. THIS PATTERN WILL PERSIST FOR MUCH OF THE EXTENDED PERIOD RESULTING IN A CHILLY PERIOD WITH BELOW NORMAL TEMPS. ONE SHORTWAVE LIFTING NE FROM THE BASE OF THE TROF WILL INDUCE CYCLOGENESIS LATE IN THE WEEKEND. THERE ARE MODEL DIFFERENCES REGARDING THE TRACK OF THIS BAROCLINIC WAVE LIFTING NE OFF THE COAST WHICH WILL IMPACT THE TIMING AND INTENSITY OF RAINFALL SUNDAY INTO SUN NIGHT. GFS DEVELOPS THE STORM FURTHER OFFSHORE WHILE NAM/ECMWF ARE MUCH CLOSER TO THE COAST. WE FOLLOWED THE ECMWF SOLUTION WHICH BRINGS A PERIOD OF WIDESPREAD RAINFALL SUN AFTERNOON INTO SUN NIGHT...FOLLOWED BY MAINLY DRY BUT COOL WEATHER EARLY NEXT WEEK. SATURDAY INTO SAT NIGHT... GT LAKES SHORTWAVE WILL BE LIFTING NORTH OF THE INTERNATIONAL BORDER WITH A COLD FRONT MOVING ACROSS SNE DURING THE DAY SATURDAY. DEEP MOISTURE AXIS AND LOW LEVEL FRONTOGENESIS WILL BE LOCATED MOSTLY BEHIND THE FRONT WITH MOST OF THE SHOWERS FALLING IN POST FRONTAL AIRMASS. EXPECT A BAND OF SHOWERS WILL BE MOVING INTO W ZONES BY EARLY AFTERNOON BUT EXPECT THE SHOWERS TO WEAKEN AS THEY MOVE EAST INTO THE COASTAL PLAIN INTO SAT EVENING AS DEEP MOISTURE DECREASES AND OUTRUNS THE BEST LOW LEVEL FORCING. PARTIAL CLEARING MOVES IN OVERNIGHT SAT NIGHT AS SUBSIDENCE DEVELOPS AHEAD OF THE NEXT SHORTWAVE. A WARM AND BREEZY DAY EXPECTED SATURDAY AHEAD OF THE FRONT WITH TEMPS GETTING INTO THE 70S IN THE COASTAL PLAIN WHERE MOST SUNSHINE IS EXPECTED...BUT COOLER 60S NW ZONES. SUNDAY INTO SUN NIGHT... FOLLOWED ECMWF SOLUTION WITH TRACK OF SFC LOW MOVING UP THE COAST. PRONOUNCED BAROCLINIC ZONE WILL SUPPORT STRONG FRONTOGENESIS WHICH COMBINED WITH DEEP MOISTURE WILL BRING WIDESPREAD RAINFALL TO THE REGION. IT APPEARS MOST OF THE MORNING MAY BE DRY WITH RAIN BEGINNING SUN AFTERNOON AND CONTINUING INTO SUN NIGHT...WITH PARTIAL CLEARING DEVELOPING FROM WEST TO EAST LATE SUN NIGHT. A CHILLY DAY ON SUNDAY WITH TEMPS MOSTLY IN THE 50S...BUT MAY BRIEFLY REACH LOWER 60S IN THE COASTAL PLAIN BEFORE FALLING AFTER ONSET OF RAIN. MONDAY... DRY AND COOL AS STORM PULLS AWAY WITH HIGH PRES BUILDING IN FROM THE WEST. 850 MB TEMPS NEAR ZERO SUPPORTS MAXES MOSTLY IN THE 50S. MON NIGHT THROUGH THU... VERY GOOD MODEL AGREEMENT ON A FULL LATITUDE RIDGE BUILDING ACROSS THE EASTERN PACIFIC INTO WESTERN CANADA AND SOUTHEAST AK. DOWNSTREAM THIS RESULTS IN A HIGH AMPLITUDE BROAD LONG WAVE TROUGH OVER CENTRAL CANADA INTO THE GREAT LAKES AND THE NORTHEAST. THIS WILL SUPPORT COOLER THAN NORMAL TEMPERATURES MUCH OF THIS PERIOD WITH AN EARLY SEASON CLIPPER LOWS PROVIDING REINFORCING INTRUSIONS OF COOLER THAN NORMAL AIRMASSES INTO NEW ENGLAND. VERY GOOD MODEL AGREEMENT AMONG THE GFS/ECMWF/GEFS AND ECENS REGARDING THE LARGE SCALE FLOW ACROSS NORTH AMERICA ALONG WITH AMPLITUDE OF THE FLOW AND SURPRISINGLY THE TIMING OF INDIVIDUAL SHORT WAVE TROUGHS. THUS ABOVE AVERAGE FORECAST CONFIDENCE ON TEMPS AND POPS THIS PERIOD. THE DAILY SENSIBLE WEATHER DETAILS... AFTER A CHILLY START MON NGT/TUE AM SOME AIRMASS MODIFICATION BEGINS TUE AND ESPECIALLY WED AHEAD OF NEXT SHORT WAVE TROUGH/CLIPPER LOW. DRY WEATHER THROUGH AT LEAST TUE NIGHT...THEN NEXT CLIPPER SYSTEM APPROACHES MID WEEK. FAIRLY ROBUST NORTHERN STREAM SHORT WAVE/AN EARLY SEASON CLIPPER LOW WITH GOOD MODEL AGREEMENT ON MEASURABLE PRECIP AND ITS TIMING WITH THIS SYSTEM. BOTH ECMWF AND GFS FOCUS PRECIP CHANCES IN THE WED/WED NIGHT TIME PERIOD. FOR THU AND FRI BEHIND STRONG CLIPPER LOW...ALL MODEL GUIDANCE IN A GOOD AGREEMENT THAT POST FRONTAL AIRMASS APPEARS COLDER THAN MON/S AIRMASS...WITH 12Z GFS/ECMWF/GEFS AND 00Z ECENS ADVERTISING 850 TEMPS FROM 0C TO TO -4C LATE LATE NEXT WEEK! && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW...MODERATE TO HIGH CONFIDENCE. IFR/LIFR CIGS TO LINGER INTO FRI MORN...GRADUALLY CLEARING W TO E THRU THE LATE OVRNGT. WILL SEE THE BULK OF THE -RA LIFT THRU THE RGN AS LATE AS MIDNIGHT FOR CENTRAL NEW ENGLAND AND TOWARDS FRI MORN FOR ERN NEW ENGLAND. LOW CONFIDENCE OF TSRA...BUT WATCHING CLOSELY THE EVOLUTION OF STORMS OVER ERN PA. IN REGARDS TO VSBYS ANTICIPATING INTERMITTENT MVFR-IFR VSBYS...ESPECIALLY WITH RA/+RA. DIFFICULT TO TIME THRU THE DAY...BUT HAVE GREATER CONFIDENCE OF VSBYS DROPPING OFF CONSIDERABLY DURING THE EVNG PD WITH THE DEVELOPMENT OF DENSE FOG /CHCS LESSER AS WINDS INCREASE OUT OF THE W/. AFTER FRI MORN...GRADUAL IMPROVEMENT TO VFR WITH CIGS LINGERING ALONG THE E SHORES. MORE TOWARDS FRI EVNG...MID-LVL CIGS WILL BE ON THE INCREASE OUT OF THE W/NW...REMAINING VFR. KBOS TAF...MODERATE CONFIDENCE. BIGGEST CHALLENGE IS SPECIFICS REGARDING TO VSBYS. LIKELY TO SEE A MIX OF LIFR TO MVFR THRU THE PD. KBDL TAF...MODERATE CONFIDENCE. MUCH LIKE KBOS...CHALLENGES PERTAIN TO VSBYS. WILL BE WATCHING TSRA CLOSELY ACROSS ERN PA AND IF THIS WILL ADVECT TOWARDS EVNG INTO THE TERMINAL. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...MODERATE CONFIDENCE. A BRIEF PERIOD OF MVFR CONDITIONS POSSIBLE...ESPECIALLY INTERIOR AS A BAND OF SHOWERS MOVES THROUGH. SUNDAY...MODERATE CONFIDENCE. LOWERING TO MVFR/IFR SUN AFTERNOON INTO SUN NIGHT IN RAIN AND FOG. MONDAY...MODERATE CONFIDENCE. VFR TUESDAY...HIGH CONFIDENCE. VFR. && .MARINE... HIGH CONFIDENCE THAT WINDS/SEAS WILL REMAIN BELOW SCA THRESHOLDS INTO FRIDAY NIGHT. THE MAIN CONCERN FOR MARINERS WILL BE AREAS OF DENSE FOG RESULTING IN POOR VISIBILITIES FOR TONIGHT...WITH THE POSSIBILITY OF VISIBILITIES DOWN TO A QUARTER MILE OR LESS AT TIMES. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...MODERATE CONFIDENCE IN PREFRONTAL SW WIND GUSTS REACHING 25 KT OVER THE NEARSHORE WATERS AND SMALL CRAFT ADVISORIES MAY BE NEEDED. DIMINISHING WINDS SAT NIGHT SHIFTING TO NW. SUNDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH TRACK AND INTENSITY OF COASTAL LOW. CURRENTLY FORECASTING SUB SCA CONDITIONS BUT COULD END UP WITH NE GUSTS REACHING SCA THRESHOLDS DEPENDING ON TRACK/INTENSITY OF LOW. MONDAY...MODERATE CONFIDENCE. NW WIND GUSTS TO 20 KT. TUESDAY... HIGH PRES LIKELY BEGINS ALONG THE EASTERN SEABOARD AND THEN SLIDES OFFSHORE WITH DEVELOPING SSW WINDS. DRY WEATHER AND GOOD VSBY EXPECTED. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/NOCERA/SIPPRELL NEAR TERM...SIPPRELL SHORT TERM...SIPPRELL LONG TERM...KJC/NOCERA AVIATION...KJC/NOCERA/SIPPRELL MARINE...KJC/NOCERA/SIPPRELL
AREA FORECAST DISCUSSION
NWS ALBANY NY
443 PM EDT THU OCT 4 2012 .SYNOPSIS... A FRONTAL BOUNDARY AND UPPER LEVEL DISTURBANCE WILL PASS THROUGH THE REGION THIS EVENING...BRINGING AN END TO THE SHOWERS. WEAK HIGH PRESSURE WILL BUILD INTO OUR AREA OVERNIGHT...BEFORE SHIFTING SOUTH AND EAST FRIDAY MORNING. A SERIES OF COLD FRONTS WILL MOVE INTO THE REGION FROM LATE FRIDAY THROUGH THE WEEKEND...RESULTING IN PERIODIC UNSETTLED WEATHER AND COOLING TEMPERATURES. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 443 PM...QUICK UPDATE TO ADD MENTION OF ISOLATED THUNDER TO SOUTHERN PORTIONS OF THE MID HUDSON VALLEY AND SOUTHERN BERKSHIRE/LITCHFIELD COUNTIES...AS A FEW CLOUD TO GROUND LIGHTNING STRIKES HAVE BEEN DETECTED ASSOCIATED WITH SOME LOW TOPPED CONVECTIVE CELLS. SBCAPE FROM SPC RUC ANALYSIS SHOWING AROUND 250-500 J/KG IN THIS LIMITED AREA...WHICH IS SUPPORTING SOME ISOLATED THUNDER. DEEP MOISTURE PLUME ALONG THE EASTERN SEABOARD WITH CONNECTION TO THE GULF OF MEXICO STILL EVIDENT ON WATER VAPOR IMAGERY LATE THIS AFTERNOON. A WEAKENING UPPER LEVEL TROUGH IS NOW MOVING THROUGH WESTERN PA/NY AND WILL CONTINUE TO PRESS EASTWARD AND ALSO SHIFT THE DEEP MOISTURE PLUME OFF TO OUR EAST THIS EVENING. AT THE SURFACE...A WEAKLY DEFINED FRONTAL BOUNDARY IS MOVING THROUGH CENTRAL NY AT THIS TIME...AND IS MORE OF A DEWPOINT BOUNDARY THAN THERMAL BOUNDARY. SO UNTIL THESE FEATURES MOVE THROUGH DURING THE EVENING...FAIRLY WIDESPREAD SHOWERS WILL CONTINUE MAINLY ALONG A LINE FROM THE UPPER HUDSON VALLEY/CAPITAL DISTRICT/EASTERN CATSKILLS EASTWARD...WITH ONLY A FEW SHOWERS TO THE NORTH AND WEST OF THIS LINE. WITH THE DEEP MOISTURE AND HUMID CONDITIONS...THERE COULD BE SOME BRIEF DOWNPOURS UNTIL THE SHOWERS END. SKIES WILL LIKELY CLEAR FROM WEST TO EAST THIS EVENING...HOWEVER DUE TO SIGNIFICANT RESIDUAL LOW LEVEL MOISTURE IN PLACE FOG WILL FORM AND WILL BE DENSE IN SPOTS. TEMPS WILL BE COOLER THAN RECENT NIGHTS...WITH DEWPOINTS DROPPING INTO THE 50S AS OPPOSED TO 60S. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... FRIDAY SHOULD END UP BEING THE WARMEST DAY OF THE WEEK ONCE FOG/LOW STRATUS CLOUDS BURN OFF DURING THE MORNING. BETTER MIXING AND A DRIER AIR MASS IN PLACE SHOULD RESULT IN SOME SUNSHINE. WITH WARM AIR ALOFT AROUND +12C AT 850MB IN PLACE ACROSS THE REGION...TEMPS SHOULD RESPOND TO SUNSHINE AND MIXING AND A SOUTHWEST FLOW BY WARMING INTO THE MID 70S IN MOST VALLEY LOCATIONS...WITH UPPER 70S SOUTH OF THE CAPITAL REGION. IT WILL BE COOLER TOWARDS THE WESTERN ADIRONDACKS...AS A WEAKENING FRONTAL BOUNDARY AND INCREASING CLOUDS APPROACH DURING THE AFTERNOON. THIS INITIAL DECAYING FRONT SHOULD ONLY RESULT IN ISOLATED TO SCATTERED SHOWERS MAINLY NORTH AND WEST OF THE CAPITAL REGION FRIDAY AFTERNOON INTO FRIDAY EVENING. HOWEVER...A SECONDARY COLD FRONT WILL BE FAST ON ITS HEELS AND MOVE INTO THE AREA LATE FRIDAY NIGHT. WITH A WEAK RIPPLE OF LOW PRESSURE EXPECTED TO DEVELOP ALONG THE FRONT...ITS PROGRESS WILL SLOW AND MOST OF THE RAIN ASSOCIATED WITH THIS SYSTEM WILL FALL ALONG OR BEHIND THE FRONT. AGAIN...IT APPEARS THAT THIS BOUNDARY WILL SET UP OVER OR JUST NORTHWEST OF THE CAPITAL REGION...SO THIS IS WHERE THE HIGHEST POPS HAVE BEEN FORECAST LATE FRIDAY NIGHT THROUGH SATURDAY MORNING. TO THE SOUTH AND EAST...WILL MENTION ONLY SLIGHT CHANCE TO CHANCE POPS. TEMPERATURES ON SATURDAY WILL BE TRICKY AND COULD VARY QUITE A BIT ACROSS THE AREA DUE TO THE SLOW MOVING COLD FRONT NOT REACHING AREAS SOUTHEAST OF ALBANY UNTIL LATE IN THE DAY. FROM ALBANY NORTH AND WEST TEMPS WILL BE MUCH COOLER THAN FRIDAY...ONLY REACHING THE MID 50S TO LOWER 60S. HOWEVER...SOUTH AND EAST OF THE FRONT...MID TO UPPER 60S ARE POSSIBLE. IN GENERAL...MOST SOURCES OF MODEL GUIDANCE HAVE BEEN TRENDING SLOWER WITH THE FRONTAL PASSAGE SINCE YESTERDAY. WILL MENTION SCATTERED SHOWERS SPREADING SOUTHEASTWARD ASSOCIATED WITH COLD FRONT SATURDAY AFTERNOON. ANOTHER BRIEF DRY PERIOD IS EXPECTED SATURDAY NIGHT AS A SMALL AND WEAK AREA OF HIGH PRESSURE BUILDS IN. HOWEVER...CLOUDS WILL LIKELY INCREASE LATE SATURDAY NIGHT...WHICH SHOULD PRECLUDE ANY FROST FORMATION DESPITE MUCH COLDER TEMPERATURES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A RATHER ACTIVE PERIOD OF WEATHER FOR THE REGION AS RATHER LARGE THERMAL PATTERN CHANGES WILL OCCUR...WITH PERHAPS A LITTLE SNOW FOR THE HIGHEST TERRAIN. A LARGE RIDGE AXIS WILL DEVELOP OVER THE NORTHERN PACIFIC OCEAN WHICH WILL RUN ALONG THE BRITISH COLUMBIA COASTLINE. MEANWHILE...DOWNSTREAM TROF IS EXPECTED TO AMPLIFY AS THE HUDSON BAY LOW EVOLVES. ONE PIECE OF POTENT ENERGY IS EXPECTED TO DIVE SOUTHWARD ALONG THE ROCKIES AND ENTER INTO THE CONFLUENCE OVER THE CENTER OF THE NATION AND BEGIN TO INTERACT WITH AN INCREASING BAROCLINIC ZONE OVER THE MID WEST. THIS WILL SET THE STAGE FOR AN UNFOLDING PRECIP EVENT FOR THE REGION ON SUNDAY. GLOBAL MODELS AND ASSOCIATED ENSEMBLES REFLECT THAT A WEAK SURFACE WAVE WILL DEVELOP WITHIN THE REGION OF MID-UPPER LEVEL DIVERGENT Q-VECTORS OVER THE EASTERN OHIO VALLEY. WE WILL INCREASE POPS BUT KEEP THOSE VALUES BELOW LIKELY THRESHOLDS AS SOME TIMING DIFFERENCES DO REMAIN. 850MB TEMPS IN THE WAKE OF THIS SYSTEM DROP BACK AT OR BELOW 0C WHERE SOME OF THE HIGHER TERRAIN COULD SEE A LITTLE BIT OF THE WHITE BUT NO ACCUMULATIONS EXPECTED. THEREAFTER...A LARGE AND ELONGATED REGION OF HIGH PRESSURE WILL MOVE IN FROM THE MID-LOWER MISSISSIPPI RIVER VALLEY AND INTO NEW ENGLAND FOR THE START OF THE WEEK. THIS WILL MODIFY THE THERMAL PROFILES WITH A WARMING TREND AS THOSE 850MB TEMPS CLIMB BACK INTO THE MID SINGLE DIGITS. HOWEVER...AS THE HUDSON BAY LOW REMAINS IN PLACE...ANOTHER SHORT WAVE IS FORECAST TO DIVE FROM CENTRAL CANADA AND INTO THE NORTHERN TIER OF THE COUNTRY FOR THE MID WEEK PERIOD. THIS WILL SET THE STAGE FOR ANOTHER OVERRUNNING EVENT WITH MANY ENSEMBLES IN AGREEMENT. SO WILL INCREASE POPS ONCE AGAIN ALONG WITH MODERATING TEMPERATURES. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... MVFR/IFR CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON HOURS AS LOW CEILINGS AND VISIBILITIES CONTINUE AS A RESULT OF LINGERING SHOWERS. THIS AFTERNOON...ABUNDANT LOW LEVEL MOISTURE AND A RIPPLE OF LOW PRESSURE WILL CONTINUE TO FUEL SCATTERED TO NUMEROUS SHOWERS ACROSS THE REGION THROUGH MOST OF THE AFTERNOON. MVFR/IFR CEILINGS AND VISIBILITIES WILL PREVAIL AS WELL WITH THESE SHOWERS. LATEST RADAR TRENDS INDICATE A SWATH OF HEAVIER RAIN SHOWERS THAT WILL MOVE ACROSS THE REGION BETWEEN 18Z AND 21Z IN ASSOCIATION WITH A PASSING UPPER LEVEL SHORTWAVE TROUGH. WENT WITH A TEMPO GROUP FROM 18-20Z TO ACCOUNT FOR THE POTENTIAL IFR CONDITIONS ASSOCIATED WITH THE PASSAGE OF THESE HEAVIER SHOWERS. WINDS WILL REMAIN LIGHT AND VARIABLE THROUGHOUT THE PERIOD. TONIGHT...THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL SLIDE OFF TO THE EAST TONIGHT ALLOWING FOR CLEARING SKIES AND A BRIEF RETURN TO VFR CONDITIONS. HOWEVER...THE CLEARING SKIES COUPLED WITH RECENT PRECIPITATION AND CALM SURFACE WINDS WILL FAVOR RAPID DEVELOPMENT OF LOW STRATUS/FOG TONIGHT AT ALL TAF LOCATIONS...WITH KGFL AND KPSF SEEING FOG ONSET AS EARLY AS 05Z...WITH KALB AND KPOU A FEW HOURS LATER. IFR CONDITIONS WILL LIKELY PERSIST INTO THE EARLY MORNING HOURS BEFORE MORNING MIXING QUICKLY ERODES ANY REMAINING LOW STRATUS/FOG BY 13Z. VFR CONDITIONS WILL RETURN FOR THE AFTERNOON FRIDAY WITH LIGHT WEST-SOUTHWESTERLY WINDS AT AROUND 4-8 KTS. OUTLOOK... SAT-MON...VFR...MVFR/IFR POSS WITH CHC -SHRA. TUE...VFR. NO SIG WX. && .FIRE WEATHER... NO FIRE WEATHER RELATED ISSUES ARE EXPECTED WITH WET/SOGGY GROUND CONDITIONS PERSISTING. A FRONTAL BOUNDARY AND UPPER LEVEL DISTURBANCE WILL PASS THROUGH THE REGION THIS EVENING...BRINGING AN END TO THE SHOWERS. WEAK HIGH PRESSURE WILL BUILD INTO OUR AREA OVERNIGHT...BEFORE SHIFTING SOUTH AND EAST FRIDAY MORNING. A SERIES OF COLD FRONTS WILL MOVE INTO THE REGION FROM LATE FRIDAY THROUGH THE WEEKEND...RESULTING IN PERIODIC UNSETTLED WEATHER AND COOLING TEMPERATURES. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS...ALTHOUGH UNSETTLED AND WET WEATHER WILL CONTINUE. ADDITIONAL RAINFALL AMOUNTS THIS EVENING WILL RUN FROM AROUND ONE TENTH TO ONE QUARTER INCH MAINLY FROM THE CAPITAL REGION SOUTH AND EAST...WITH SOME ISOLATED AMOUNTS OF UP TO ONE HALF INCH WHERE A FEW PERSISTENT DOWNPOURS OCCUR. RUNOFF FROM THE RAINFALL TODAY AND THIS EVENING WILL GENERALLY RESULT IN RISES OF UP TO TWO FEET ON MAIN STEM RIVERS. A BREAK IN THE RAINFALL WILL OCCUR TONIGHT THROUGH FRIDAY MORNING...BEFORE ADDITIONAL SHOWERS MOVE BACK ASSOCIATED WITH ANOTHER FRONTAL BOUNDARY LATE FRIDAY THROUGH SATURDAY. RAINFALL AMOUNTS SHOULD BE GENERALLY LIGHT DURING THIS TIME...AROUND ONE TENTH TO ONE THIRD OF AN INCH...WITH THE HIGHER AMOUNTS NORTH AND WEST OF ALBANY. ANOTHER BREAK IS EXPECTED SATURDAY NIGHT INTO SUNDAY MORNING...BEFORE MORE RAINFALL MOVES BACK IN SUNDAY AFTERNOON AND NIGHT ASSOCIATED WITH A DEVELOPING LOW PRESSURE SYSTEM. THIS SYSTEM MAY BRING GREATER RAINFALL AMOUNTS...BUT SHOULD GENERALLY BE LESS THAN AN INCH. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...BGM AVIATION...IAA/IRL FIRE WEATHER...JPV HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS TAUNTON MA
432 PM EDT THU OCT 4 2012 .SYNOPSIS... RAIN WILL SWEEP ACROSS THE REGION TONIGHT. IN ITS WAKE FOG IS EXPECTED TO DEVELOP WITH VISIBILITIES DOWN TO A QUARTER MILE OR LESS. WARM AND DRY WEATHER FOLLOWS FOR FRIDAY INTO FRIDAY NIGHT. ANOTHER COLD FRONT WILL BRING A CHANCE OF SHOWERS SATURDAY...THEN A PERIOD OF CHILLY RAIN IS EXPECTED SUNDAY AFTERNOON INTO SUN NIGHT AS LOW PRESSURE MOVES UP THE COAST. DRIER WEATHER IS EXPECTED EARLY NEXT WEEK BUT WILL BE ACCOMPANIED BY COOLER THAN NORMAL TEMPERATURES. DRY AND COOL WEATHER IS EXPECTED MUCH OF NEXT WEEK FOLLOWED BY THE CHANCE OF SHOWERS MID WEEK AS AN EARLY SEASON CLIPPER LOW MOVES ACROSS THE REGION. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS IT LIFTS OUT OF THE RGN...THE BAROCLINIC TROF WITH ATTENDANT SHRTWV ENERGY DEAMPLIFIES IN RESPONSE TO RIDGING AHEAD OF A DEEPER CYCLONIC SYSTEM EJECTING INTO THE NRN TIER OF THE CONUS. THE APPROACHING SFC COLD FRNT SHOULD BECOME DIFFUSE AS SHOWERS COME TO AN END. EXPECTING THE BETTER RGN OF SHOWERS TO PREVAIL NEWD THRU CENTRAL AND NRN NEW ENGLAND PARENT WITH THE BETTER DYNAMICS TRANSLATING INTO THE ST LAWRENCE RVR VLY. SOME UNCERTAINTY AS TO THE LINE OVER THE HUDSON VLY RGN...WRF MDL SOLNS SUGGEST A GRADUAL TURNING TO DUE EAST. WHILE NOT TOTALLY ON BOARD WITH THIS SOLN AS IT/LL BE INTERESTING THE OUTCOME OF THE LINE AS IT MOVES E OF THE BERKSHIRES INTO A LESS FAVORABLE AIRMASS PER 12Z CHATHAM SOUNDING. WILL USHER LIKELY POPS...BUT ANTICIPATE THE STRENGTH OF THE LINE TO DIMINISH WITH EWD PROGRESSION /FOLLOWING THE 16Z HRRR CLOSELY/. SUBSIDENCE TO THE REAR COUPLED WITH HIGH PRES SHOULD ALLOW CONDITIONS TO GRADUALLY CLEAR AND IMPROVE...YET ABUNDANT REMNANT MOISTURE SHOULD REMAIN. THOUGH SKIES ARE EXPECTED TO CLEAR...WITH WEAK FLOW TOWARDS FRIDAY MORNING...WIDESPREAD FOG SHOULD DEVELOP ACROSS THE RGN AS SFC TEMPS FALL CLOSE TO OR AT THE DWPT /MINS AROUND THE MID 50S/. ANTICIPATING VSBYS DOWN TO ONE QUARTER OF A MILE OR LESS IN AREAS. DENSE FOG ADVISORIES APPEARING LIKELY. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FRIDAY... FOG WILL GRADUALLY BURN OFF INTO THE LATE MORNING PD. AREAS OF DENSE FOG ARE LIKELY TO IMPACT THE MORNING COMMUTE. ANTICIPATING MOSTLY CLEAR CONDITIONS WITH INCREASING CLOUDS LATE. DEEP MIXING OF THE BOUNDARY LYR SHOULD PREVAIL UP TO H85 INTO THE AFTN PD WHERE TEMPS RANGE FROM 10-12C. MAX TEMPS INTO THE LOW 80S IS CERTAINLY PLAUSIBLE UNDER LIGHT W/SWLY FLOW. FCST GUIDANCE IN CONSENSUS OF KEEPING THE PD DRY. FRIDAY NIGHT... WILL KEEP THE PD DRY AS THE BETTER FORCING LIES ACROSS THE ERN GRT LKS RGN AND SRN NEW ENGLAND REMAINS UNDER THE INFLUENCE OF STRONG HIGH PRES. W/SWLY FLOW PREVAILS USHERING A REBOUND OF SFC MOISTURE FROM DRIER CONDITIONS ON FRIDAY...DWPTS INCREASING INTO AND AROUND THE LOW 60S. THERE IS THE POTENTIAL FOR A RETURN OF LOW CLOUDS OR FOG INTO THE SAT MORNING PD /THE BETTER CHCS FOR FOG ALONG THE SRN SHORELINE OF NEW ENGLAND/. A MILD NGT WITH LOWS DOWN INTO THE MID- UPR 50S /LOW 60S PSBL ALONG THE S COASTLINE/. && .LONG TERM /SATURDAY THROUGH THURSDAY/... * CHANCE OF SHOWERS SATURDAY BUT STILL WARM AND BREEZY COASTAL PLAIN * CHILLY RAIN SUNDAY AFTERNOON INTO SUN NIGHT * DRY AND COOL WEATHER RETURNS EARLY NEXT WEEK OVERVIEW... MODELS ARE IN GOOD AGREEMENT ON GENERAL PATTERN THROUGH EARLY NEXT WEEK. STRONG RIDGING EXTENDING NORTH FROM OFF THE WEST COAST OF CANADA WILL PROMOTE BROAD DOWNSTREAM LONGWAVE TROF OVER THE GT LAKES. THIS PATTERN WILL PERSIST FOR MUCH OF THE EXTENDED PERIOD RESULTING IN A CHILLY PERIOD WITH BELOW NORMAL TEMPS. ONE SHORTWAVE LIFTING NE FROM THE BASE OF THE TROF WILL INDUCE CYCLOGENESIS LATE IN THE WEEKEND. THERE ARE MODEL DIFFERENCES REGARDING THE TRACK OF THIS BAROCLINIC WAVE LIFTING NE OFF THE COAST WHICH WILL IMPACT THE TIMING AND INTENSITY OF RAINFALL SUNDAY INTO SUN NIGHT. GFS DEVELOPS THE STORM FURTHER OFFSHORE WHILE NAM/ECMWF ARE MUCH CLOSER TO THE COAST. WE FOLLOWED THE ECMWF SOLUTION WHICH BRINGS A PERIOD OF WIDESPREAD RAINFALL SUN AFTERNOON INTO SUN NIGHT...FOLLOWED BY MAINLY DRY BUT COOL WEATHER EARLY NEXT WEEK. SATURDAY INTO SAT NIGHT... GT LAKES SHORTWAVE WILL BE LIFTING NORTH OF THE INTERNATIONAL BORDER WITH A COLD FRONT MOVING ACROSS SNE DURING THE DAY SATURDAY. DEEP MOISTURE AXIS AND LOW LEVEL FRONTOGENESIS WILL BE LOCATED MOSTLY BEHIND THE FRONT WITH MOST OF THE SHOWERS FALLING IN POST FRONTAL AIRMASS. EXPECT A BAND OF SHOWERS WILL BE MOVING INTO W ZONES BY EARLY AFTERNOON BUT EXPECT THE SHOWERS TO WEAKEN AS THEY MOVE EAST INTO THE COASTAL PLAIN INTO SAT EVENING AS DEEP MOISTURE DECREASES AND OUTRUNS THE BEST LOW LEVEL FORCING. PARTIAL CLEARING MOVES IN OVERNIGHT SAT NIGHT AS SUBSIDENCE DEVELOPS AHEAD OF THE NEXT SHORTWAVE. A WARM AND BREEZY DAY EXPECTED SATURDAY AHEAD OF THE FRONT WITH TEMPS GETTING INTO THE 70S IN THE COASTAL PLAIN WHERE MOST SUNSHINE IS EXPECTED...BUT COOLER 60S NW ZONES. SUNDAY INTO SUN NIGHT... FOLLOWED ECMWF SOLUTION WITH TRACK OF SFC LOW MOVING UP THE COAST. PRONOUNCED BAROCLINIC ZONE WILL SUPPORT STRONG FRONTOGENESIS WHICH COMBINED WITH DEEP MOISTURE WILL BRING WIDESPREAD RAINFALL TO THE REGION. IT APPEARS MOST OF THE MORNING MAY BE DRY WITH RAIN BEGINNING SUN AFTERNOON AND CONTINUING INTO SUN NIGHT...WITH PARTIAL CLEARING DEVELOPING FROM WEST TO EAST LATE SUN NIGHT. A CHILLY DAY ON SUNDAY WITH TEMPS MOSTLY IN THE 50S...BUT MAY BRIEFLY REACH LOWER 60S IN THE COASTAL PLAIN BEFORE FALLING AFTER ONSET OF RAIN. MONDAY... DRY AND COOL AS STORM PULLS AWAY WITH HIGH PRES BUILDING IN FROM THE WEST. 850 MB TEMPS NEAR ZERO SUPPORTS MAXES MOSTLY IN THE 50S. MON NIGHT THROUGH THU... VERY GOOD MODEL AGREEMENT ON A FULL LATITUDE RIDGE BUILDING ACROSS THE EASTERN PACIFIC INTO WESTERN CANADA AND SOUTHEAST AK. DOWNSTREAM THIS RESULTS IN A HIGH AMPLITUDE BROAD LONG WAVE TROUGH OVER CENTRAL CANADA INTO THE GREAT LAKES AND THE NORTHEAST. THIS WILL SUPPORT COOLER THAN NORMAL TEMPERATURES MUCH OF THIS PERIOD WITH AN EARLY SEASON CLIPPER LOWS PROVIDING REINFORCING INTRUSIONS OF COOLER THAN NORMAL AIRMASSES INTO NEW ENGLAND. VERY GOOD MODEL AGREEMENT AMONG THE GFS/ECMWF/GEFS AND ECENS REGARDING THE LARGE SCALE FLOW ACROSS NORTH AMERICA ALONG WITH AMPLITUDE OF THE FLOW AND SURPRISINGLY THE TIMING OF INDIVIDUAL SHORT WAVE TROUGHS. THUS ABOVE AVERAGE FORECAST CONFIDENCE ON TEMPS AND POPS THIS PERIOD. THE DAILY SENSIBLE WEATHER DETAILS... AFTER A CHILLY START MON NGT/TUE AM SOME AIRMASS MODIFICATION BEGINS TUE AND ESPECIALLY WED AHEAD OF NEXT SHORT WAVE TROUGH/CLIPPER LOW. DRY WEATHER THROUGH AT LEAST TUE NIGHT...THEN NEXT CLIPPER SYSTEM APPROACHES MID WEEK. FAIRLY ROBUST NORTHERN STREAM SHORT WAVE/AN EARLY SEASON CLIPPER LOW WITH GOOD MODEL AGREEMENT ON MEASURABLE PRECIP AND ITS TIMING WITH THIS SYSTEM. BOTH ECMWF AND GFS FOCUS PRECIP CHANCES IN THE WED/WED NIGHT TIME PERIOD. FOR THU AND FRI BEHIND STRONG CLIPPER LOW...ALL MODEL GUIDANCE IN A GOOD AGREEMENT THAT POST FRONTAL AIRMASS APPEARS COLDER THAN MON/S AIRMASS...WITH 12Z GFS/ECMWF/GEFS AND 00Z ECENS ADVERTISING 850 TEMPS FROM 0C TO TO -4C LATE LATE NEXT WEEK! && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW...MODERATE TO HIGH CONFIDENCE. IFR/LIFR CIGS TO LINGER INTO FRI MORN...GRADUALLY CLEARING W TO E THRU THE LATE OVRNGT. WILL SEE THE BULK OF THE -RA LIFT THRU THE RGN AS LATE AS MIDNIGHT FOR CENTRAL NEW ENGLAND AND TOWARDS FRI MORN FOR ERN NEW ENGLAND. LOW CONFIDENCE OF TSRA...BUT WATCHING CLOSELY THE EVOLUTION OF STORMS OVER ERN PA. IN REGARDS TO VSBYS ANTICIPATING INTERMITTENT MVFR-IFR VSBYS...ESPECIALLY WITH RA/+RA. DIFFICULT TO TIME THRU THE DAY...BUT HAVE GREATER CONFIDENCE OF VSBYS DROPPING OFF CONSIDERABLY DURING THE EVNG PD WITH THE DEVELOPMENT OF DENSE FOG /CHCS LESSER AS WINDS INCREASE OUT OF THE W/. AFTER FRI MORN...GRADUAL IMPROVEMENT TO VFR WITH CIGS LINGERING ALONG THE E SHORES. MORE TOWARDS FRI EVNG...MID-LVL CIGS WILL BE ON THE INCREASE OUT OF THE W/NW...REMAINING VFR. KBOS TAF...MODERATE CONFIDENCE. BIGGEST CHALLENGE IS SPECIFICS REGARDING TO VSBYS. LIKELY TO SEE A MIX OF LIFR TO MVFR THRU THE PD. KBDL TAF...MODERATE CONFIDENCE. MUCH LIKE KBOS...CHALLENGES PERTAIN TO VSBYS. WILL BE WATCHING TSRA CLOSELY ACROSS ERN PA AND IF THIS WILL ADVECT TOWARDS EVNG INTO THE TERMINAL. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...MODERATE CONFIDENCE. A BRIEF PERIOD OF MVFR CONDITIONS POSSIBLE...ESPECIALLY INTERIOR AS A BAND OF SHOWERS MOVES THROUGH. SUNDAY...MODERATE CONFIDENCE. LOWERING TO MVFR/IFR SUN AFTERNOON INTO SUN NIGHT IN RAIN AND FOG. MONDAY...MODERATE CONFIDENCE. VFR TUESDAY...HIGH CONFIDENCE. VFR. && .MARINE... HIGH CONFIDENCE THAT WINDS/SEAS WILL REMAIN BELOW SCA THRESHOLDS INTO FRIDAY NIGHT. THE MAIN CONCERN FOR MARINERS WILL BE AREAS OF DENSE FOG RESULTING IN POOR VISIBILITIES FOR TONIGHT...WITH THE POSSIBILITY OF VISIBILITIES DOWN TO A QUARTER MILE OR LESS AT TIMES. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...MODERATE CONFIDENCE IN PREFRONTAL SW WIND GUSTS REACHING 25 KT OVER THE NEARSHORE WATERS AND SMALL CRAFT ADVISORIES MAY BE NEEDED. DIMINISHING WINDS SAT NIGHT SHIFTING TO NW. SUNDAY...LOW CONFIDENCE DUE TO UNCERTAINTY WITH TRACK AND INTENSITY OF COASTAL LOW. CURRENTLY FORECASTING SUB SCA CONDITIONS BUT COULD END UP WITH NE GUSTS REACHING SCA THRESHOLDS DEPENDING ON TRACK/INTENSITY OF LOW. TUESDAY... HIGH PRES LIKELY BEGINS ALONG THE EASTERN SEABOARD AND THEN SLIDES OFFSHORE WITH DEVELOPING SSW WINDS. DRY WEATHER AND GOOD VSBY EXPECTED. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/NOCERA/SIPPRELL NEAR TERM...SIPPRELL SHORT TERM...FRANK/SIPPRELL LONG TERM...FRANK/NOCERA AVIATION...FRANK/NOCERA/SIPPRELL MARINE...FRANK/NOCERA/SIPPRELL
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
614 PM EDT THU OCT 4 2012 .SYNOPSIS... WEAK HIGH PRESSURE FROM THE SOUTHERN STATES WILL BUILD ACROSS THE AREA TONIGHT AND REMAIN THROUGH FRIDAY. LOW PRESSURE WILL MOVE ACROSS ONTARIO AND QUEBEC THIS WEEKEND. AN ASSOCIATED COLD FRONT WILL CROSS THE MIDDLE ATLANTIC REGION LATE SATURDAY AFTERNOON AND EVENING. A WAVE OF LOW PRESSURE WILL MOVE ALONG THE FRONT ON SUNDAY. HIGH PRESSURE WILL BUILD BACK ACROSS THE AREA EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... A MID LEVEL TROUGH EXTENDED FROM EASTERN ONTARIO TO THE CAROLINAS THIS AFTERNOON. THE AXIS OF THE TROUGH IS FORECAST TO PASS OVERHEAD THIS EVENING. SOME SHOWERS AND POSSIBLE THUNDERSTORMS HAVE DEVELOPED RIGHT ALONG THE FRONTAL BOUNDARY. THE LATEST HRRR HAS A GOOD TIMING DEPICTION (EVEN IF THE EXTENT IS OVERDONE). GRIDS AND FCST HAVE BEEN UPDATED TO REFLECT THIS THINKING. HOPEFULLY THIS WILL BE THE LAST TIME IN 2012 WE WILL HAVE TO TYPE THE FRONTAL BOUNDARY WILL REMOVE THE 70 PLUS DEW POINTS AS THE EVENING PROGRESSES. OTHERWISE REST OF FCST KEPT PRETTY MUCH THE SAME AS CLOUDS ARE DECREASING RAPIDLY OVER EASTERN PA. HIGH PRESSURE IS FORECAST TO NOSE UP INTO OUR REGION FROM THE SOUTHWEST FOR TONIGHT. AS A RESULT, A MOSTLY CLEAR SKY IS EXPECTED ALONG WITH A LIGHT WIND, MAINLY FROM THE WEST. TEMPERATURES SHOULD DROP INTO THE 50S AND LOWER 60S IN OUR REGION. WITH THE LIGHT WIND AND THE RECENT RAIN AND HUMIDITY, SOME PATCHY FOG IS ANTICIPATED FOR LATE TONIGHT, MAINLY OUTSIDE OF URBAN AREAS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... THE AREA OF HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR REGION ON FRIDAY. A MOSTLY SUNNY SKY IS EXPECTED ALONG WITH A WEST TO SOUTHWEST WIND AROUND 5 TO 10 MPH. WITH A WEST SOUTHWEST FLOW ALOFT, TEMPERATURES ARE EXPECTED TO BE AROUND +12C AT 850 HPA RESULTING IN ANOTHER MILD DAY. AFTERNOON TEMPERATURES AT THE SURFACE SHOULD BE ABOUT 10 DEGREES ABOVE NORMAL. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... THE WEAK UPPER AND SFC RIDGING ACROSS THE AREA FRI NIGHT WILL MOVE QUICKLY TO THE EAST DURING SATURDAY. AN ONGOING PATTERN CHANGE ALOFT WILL BRING LOWER H5 HEIGHTS ACROSS THE GREAT LAKES AS DEEP LOW PRESSURE MOVES ACROSS ONTARIO AND QUEBEC THIS WEEKEND. THIS PATTERN CHANGE WILL ARRIVE ACROSS OUR AREA IN THE FORM OF A COLD FRONT DURING SATURDAY. ORGANIZED PCPN AHEAD OF THE FRONT...TO OUR WEST...EARLY SATURDAY FALLS APART AS THE FRONT SEEMS TO OUTRUN THE DEEPER MOISTURE. POPS WERE HELD IN THE CHC RANGE FOR SAT AT THIS POINT. THE BETTER CHC WILL BE ACROSS THE WRN AREAS DURING THE FIRST PART OF THE DAY. FURTHER EAST AND SOUTH...WE WILL KEEP ONLY SLGT CHC POPS FOR SAT THEN CHC POPS FOR SAT NIGHT. SAT WILL BE THE LAST ABOVE NORMAL TEMPERATURE DAY FOR AWHILE WITH SOME MID 70S ACROSS SRN NJ AND THE DELMARVA. FURTHER NORTH AND WEST HIGHS MAY ONLY REACH THE MID 60S WITH MORE CLOUDS EXPECTED. COLDER AIR WILL SWEEP ACROSS THE AREA SAT NIGHT AND REMAIN INTO EARLY NEXT WEEK. HIGHS ON SUNDAY WILL BE NOTICEABLY COLDER WITH HIGHS IN THE 50S IN MOST AREAS WITH PERHAPS A FEW LOW 60S OVER THE DELMARVA AREA. THESE READINGS WILL BE 5 TO 10 DEGREES BELOW NORMAL FOR EARLY OCTOBER. A BATCH OF RAIN WILL ACCOMPANY A WAVE OF LOW PRESSURE WHICH WILL RIDE ALONG THE FRONT SUN. LOW LIKELY POPS WILL BE KEPT IN THE FCST FOR SUNDAY WITH THIS FEATURE. QPF COULD BE 1/4 TO 1/2 INCH. DRIER AIR AND HIGH PRESSURE WILL RETURNS EARLY NEXT WEEK. TEMPERATURES WILL BE MUCH BELOW NORMAL AT THE BEGINNING OF THE WEEK WITH READINGS MODERATING BY WEDNESDAY. LOW TEMPERATURES ACROSS THE SOUTHERN POCONOS AND NORTHERN NEW JERSEY MAY BE COLD ENOUGH FOR SOME FROST MONDAY AND TUESDAY MORNINGS. ITS TOO EARLY TO TELL WHETHER IT WILL BE WIDESPREAD OF JUST PATCHY...SOMETHING TO WATCH OVER THE NEXT FEW DAYS. FURTHER SOUTH...LOWS MONDAY MORNING WILL BE CLOSE TO 40 DEGREES. THE HIGH WILL REMAIN ACROSS THE AREA MON AND TUE THEN ANOTHER LOW AND ASSOCIATED FRONT WILL CROSS THE AREA WEDNESDAY. CHC POPS WERE INSERTED ACROSS THE NORTHERN AND WESTERN AREAS FOR NOW. && .AVIATION /22Z THURSDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONDITIONS ARE EXPECTED TO BE VFR AT OUR EIGHT TAF SITES FOR THE LATE AFTERNOON AND EVENING HOURS AS THE SKY CONTINUES TO CLEAR. THE WIND SHOULD BECOME WESTERLY AROUND 6 TO 8 KNOTS. FOR TONIGHT, A MAINLY CLEAR SKY IS ANTICIPATED ALONG WITH A LIGHT WIND AT 5 KNOTS OR LESS. IF THE WIND FAVORS ANY DIRECTION, IT WILL BE THE WEST. SOME PATCHY FOG MAY DEVELOP LATE TONIGHT. WE HAVE INDICATED SOME VISIBILITY RESTRICTIONS AT KRDG, KABE, KTTN, KILG AND KMIV. FOR KPNE, KPHL AND KACY WHICH TEND TO BE LESS AFFECTED BY RADIATION FOG, WE HAVE INCLUDED NO VISIBILITY RESTRICTIONS. FRIDAY WILL BE A MOSTLY SUNNY DAY WITH A WEST TO SOUTHWEST WIND AROUND 6 TO 8 KNOTS. OUTLOOK... FRI NIGHT THRU SAT NIGHT...MOSTLY VFR WITH A FEW SCATTERED SHOWERS LATER SATURDAY. SUN-SUN NIGHT...POOR CONDITIONS EXPECTED WITH MVFR AND POSSIBLY SOME IFR AT TIMES. MON-TUE...MOSTLY VFR. && .MARINE... A FRONTAL BOUNDARY FROM THE WEST IS FORECAST TO REACH THE COASTAL WATERS OF NEW JERSEY AND DELAWARE DURING THE LATE AFTERNOON AND EVENING HOURS. HIGH PRESSURE WILL FOLLOW FOR TONIGHT AND FRIDAY. WIND SPEEDS AND WAVE HEIGHTS WILL REMAIN BELOW THE SMALL CRAFT ADVISORY CRITERIA DURING THE PERIOD OUTLOOK... SUB-SCA CONDITIONS FOR THE MOST PART. A COLD FRONT WILL BRING SOME GUSTY WINDS AND HIGHER SEAS SAT NIGHT INTO SUNDAY. MARGINAL SCA CONDITIONS POSSIBLE THEN. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...O`HARA NEAR TERM...O`GIGI/IOVINO SHORT TERM...IOVINO LONG TERM...O`HARA AVIATION...IOVINO MARINE...IOVINO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1230 PM CDT THU OCT 4 2012 .DISCUSSION... ISSUED 1014 AM CDT THU OCT 4 2012 COLD FRONT HAS MADE IT TO ROUGHLY THE ILLINOIS/IOWA BORDER BY 10 AM...WITH TEMPERATURES QUICKLY DROPPING OFF BEHIND IT. LATEST HRRR GUIDANCE PLACES IT NEAR THE ILLINOIS RIVER BY NOON AND APPROACHING THE I-57 CORRIDOR BY LATE AFTERNOON...ALTHOUGH THE NAM AND RAP MODELS ARE A BIT SLOWER WITH IT NEAR I-55 INSTEAD. ALL THE SHOWERS HAVE BEEN POST-FRONTAL SO FAR...AND EXTENDED FROM EASTERN IOWA TO NORTHERN MISSOURI. EARLIER FORECAST FOR INCREASING POPS ALONG AND NORTHWEST OF THE ILLINOIS RIVER THIS AFTERNOON STILL LOOKS GOOD. COLD AIR ADVECTION BEHIND THE FRONT WILL RESULT IN FALLING TEMPERATURES THIS AFTERNOON WEST OF THE I-55 CORRIDOR... WHILE GUSTY SOUTHWEST WINDS AND MORE SUNSHINE HELP BOOST TEMPERATURES TO AROUND 80 DEGREES OR SO IN THE SOUTHEAST HALF OF THE FORECAST AREA. UPDATED FORECASTS HAVE BEEN SENT...MAINLY TO ADJUST THE HOURLY TEMPERATURE AND DEW POINT GRIDS. GEELHART && .AVIATION... ISSUED 1230 PM CDT THU OCT 4 2012 COLD FRONT WILL PUSH ACROSS THE TAF SITES THROUGH ABOUT 00Z... SHIFTING WINDS TO THE WEST AND THEN NORTHWEST. A NARROW BAND OF CONVECTION IS CURRENTLY JUST BEHIND THE FRONT...AND AWIPS TIME-OF- ARRIVAL TOOL BRINGS IT INTO KPIA AROUND 1845Z AND KBMI AROUND 20Z. WILL CARRY VCTS MENTION AT THESE SITES FOR AN HOUR OR TWO EARLY IN THE FORECAST PERIOD...AS THE LINE IS SOMEWHAT BROKEN. ADDITIONAL RAIN CURRENTLY OVER NORTHERN MISSOURI MAY BEGIN TO AFFECT THE WESTERN TAF SITES LATE THIS AFTERNOON. MAIN CONCERN LATER IN THE FORECAST PERIOD IS WITH A BAND OF RAIN THAT IS FORECAST TO DEVELOP OVER CENTRAL ILLINOIS LATE IN THE NIGHT. CURRENT MODEL PROJECTIONS FAVOR THE KSPI-KCMI CORRIDOR AS MOST LIKELY TO BE AFFECTED BY IT...DEVELOPING BETWEEN 06-12Z AND PERSISTING INTO MIDDAY. FORECAST SOUNDINGS SHOW MVFR CEILINGS DEVELOPING IN ASSOCIATION WITH THIS BAND...AND HAVE ADDED CEILINGS AROUND 2500 FEET LATE IN THE TAF PERIOD. HOWEVER...NAM SOUNDINGS DO SHOW SOME POTENTIAL FOR CEILINGS AS LOW AS 1200 FEET...SO WILL NEED TO KEEP AN EYE ON THIS FOR FRIDAY MORNING. GEELHART && .PREV DISCUSSION... ISSUED 234 AM CDT THU OCT 4 2012 SHORT TERM...TODAY THROUGH SATURDAY UPPER TROUGH THAT HAS PLAGUED CENTRAL ILLINOIS FOR THE PAST FEW DAYS IS FINALLY BEING EJECTED NORTHEASTWARD EARLY THIS MORNING. 06Z/1AM RADAR IMAGERY SHOWS SCATTERED LIGHT SHOWERS LINGERING EAST OF I-55...HOWEVER THESE WILL PUSH FURTHER EASTWARD INTO INDIANA BY 12Z/7AM. AS A RESULT...AM EXPECTING THE DAY TO START OFF MOSTLY SUNNY ACROSS THE BOARD...BEFORE HIGH CLOUDS BEGIN TO INCREASE FROM THE NORTHWEST BY LATE MORNING. VIGOROUS SHORT-WAVE TROUGH EVIDENT ON LATEST WATER VAPOR IMAGERY OVER SOUTH DAKOTA WILL TRACK E/NE TODAY...DRAGGING A STRONG COLD FRONT INTO ILLINOIS THIS AFTERNOON. BOTH THE NAM AND GFS ARE IN GOOD AGREEMENT WITH THE TIMING OF THE FRONT...PLACING IT ALONG A LINE FROM JUST SOUTH OF CHICAGO TO NEAR SAINT LOUIS BY EARLY EVENING. AHEAD OF THE FRONT...GUSTY SOUTHWESTERLY WINDS WILL TRANSPORT MUCH WARMER AIR INTO THE REGION...WITH AFTERNOON HIGH TEMPERATURES TOPPING OUT IN THE UPPER 70S AND LOWER 80S. PRECIP ASSOCIATED WITH THIS FEATURE WILL BE POST-FRONTAL...SO HAVE CONFINED POPS TO LOCATIONS ALONG AND NORTHWEST OF THE ILLINOIS RIVER BY MID TO LATE AFTERNOON. RAIN CHANCES WILL SPREAD AS FAR EAST AS A DANVILLE TO TAYLORVILLE LINE DURING THE EVENING...AS THE FRONT SINKS SOUTHWARD TOWARD THE OHIO RIVER. GIVEN STRONG UPPER DYNAMICS ASSOCIATED WITH APPROACHING WAVE...WILL INCLUDE ISOLATED THUNDER MENTION THIS AFTERNOON AND EVENING. 850-700MB FRONTOGENESIS INCREASES GREATLY OVERNIGHT AS MID-LEVEL FRONT STALLS ACROSS CENTRAL ILLINOIS. WITH ANOTHER SHORT-WAVE TROUGH RIPPLING ALONG THE BOUNDARY AND THE ATMOSPHERE MOISTENING FURTHER...EXPECT SHOWERS TO INCREASE IN AREAL COVERAGE AFTER MIDNIGHT. BOTH THE NAM AND GFS HAVE SHIFTED THIS POST-FRONTAL RAINFALL FURTHER NORTHWARD...WITH THE GFS SHOWING THE GREATEST NORTHWARD TREND. WILL FOLLOW THE SLIGHTLY MORE CONSISTENT NAM IN THE SHORT-TERM...WHICH DEVELOPS RAIN ACROSS ALL LOCATIONS ALONG/NORTH OF I-70 OVERNIGHT INTO FRIDAY MORNING. HAVE BUMPED POPS UP TO LIKELY ACCORDINGLY. SHOWERS WILL CONTINUE ACROSS MUCH OF CENTRAL AND SOUTHEAST ILLINOIS ON FRIDAY...AS FRONT MAKES ONLY GRADUAL PROGRESS SOUTHWARD. FORECAST SOUNDINGS SHOW RATHER STEEP LAPSE RATES ABOVE 700MB...SUGGESTING THE POTENTIAL FOR A FEW THUNDERSTORMS AS WELL. SPC DAY 2 CONVECTIVE OUTLOOK PLACES A GOOD PORTION OF THE AREA IN THE GENERAL THUNDER CATEGORY...SO HAVE INCLUDED ISOLATED THUNDER MENTION ALONG AND SOUTH OF A BLOOMINGTON TO RUSHVILLE LINE. WITH RAIN AND COOL N/NE FLOW BEHIND THE FRONT...TEMPERATURES ON FRIDAY WILL BE MUCH COOLER THAN TODAY...WITH MOST LOCATIONS REMAINING IN THE LOWER TO MIDDLE 50S. AS UPPER WAVE SHIFTS OFF TO THE EAST...FRONT WILL GET PUSHED FURTHER SOUTH FRIDAY NIGHT. WILL CARRY POPS ALONG/SOUTH OF I-72 DURING THE EVENING...THEN JUST SOUTH OF I-70 AFTER MIDNIGHT. TOTAL RAINFALL FROM THIS SYSTEM WILL BE HEAVIEST ACROSS THE HEART OF CENTRAL ILLINOIS FROM THE CHAMPAIGN AREA WESTWARD TO JACKSONVILLE...WHERE AMOUNTS OF AROUND ONE HALF INCH WILL BE COMMON. THE LIGHTEST RAINFALL OF ONE QUARTER OF AN INCH OR LESS WILL OCCUR FURTHER NORTH FROM THE PEORIA AREA NORTHWARD. DRY WEATHER WILL RETURN ON SATURDAY...HOWEVER THERE IS STILL SOME QUESTION CONCERNING ANOTHER UPPER-LEVEL WAVE DROPPING OUT OF THE NORTHERN PLAINS. THIS FEATURE HAS THE POTENTIAL TO LIFT PRECIP BACK NORTHWARD TOWARD THE SE KILX CWA SATURDAY NIGHT...HOWEVER BOTH THE NAM AND GFS NOW KEEP THE RAIN SOUTH OF THE AREA ACROSS THE OHIO RIVER VALLEY. MEANWHILE...THE 00Z 4 OCT ECMWF BRINGS THE PRECIP MUCH FURTHER NORTH INTO EAST-CENTRAL AND SOUTHEAST ILLINOIS. AT THIS POINT...WILL MAINTAIN CLOUD COVER ACROSS THE E/SE SATURDAY NIGHT...BUT WILL KEEP RAIN OUT OF THE FORECAST. MAIN STORY SATURDAY NIGHT WILL BE THE MUCH COLDER CONDITIONS...AS TEMPERATURES POTENTIALLY DIP INTO THE LOWER 30S ALONG/NORTHWEST OF I-55. LONG TERM...SUNDAY THROUGH WEDNESDAY CHILLY CONDITIONS WILL PREVAIL ON SUNDAY...WITH HIGHS ONLY IN THE 50S AND OVERNIGHT LOWS ONCE AGAIN DIPPING INTO THE LOWER TO MIDDLE 30S. AFTER THAT...RETURN FLOW ON THE BACK SIDE OF DEPARTING HIGH PRESSURE WILL BRING MODERATING TEMPS EARLY NEXT WEEK. WITH 850MB TEMPS REACHING THE 6 TO 8C RANGE...HIGH TEMPS WILL CLIMB BACK INTO THE MIDDLE 60S BY TUESDAY. NEXT WEAK COLD FRONT IS SLATED TO PASS THROUGH THE REGION BY THE MIDDLE OF NEXT WEEK...WITH MODEL CONSENSUS BRINGING THE FRONT THROUGH CENTRAL ILLINOIS TUESDAY NIGHT. WILL CARRY LOW CHANCE POPS WITH FROPA...FOLLOWED BY COOL/DRY WEATHER FOR WEDNESDAY. BARNES && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 PM EDT THU OCT 4 2012 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 423 PM EDT THU OCT 4 2012 WV LOOP AND RUC ANALYSIS SHOW NEGATIVE TILTED SHORTWAVE TROUGH OVER NORTHERN MINNESOTA THIS AFTN WITH ASSOCIATED SFC LOW IN THE VCNTY OF KINL. COLD FRONT IS IN PROCESS OF MAKING ITS WAY ACROSS UPR MICHIGAN...BUT MUCH COLDER AIR IS LAGGING BEHIND OVER NORTHERN MINNESOTA. HAVE SEEN ISOLD SHRA FORM THIS AFTN WITH EVEN TSRA. MAIN AREA WAS ON KEWEENAW BUT JUST WITHIN LAST 1 HR ANOTHER LINE OF SHRA HAS FORMED OVER EASTERN LK SUPERIOR/FAR NORTHEAST CWA. DEEP DRYING WRAPPING IN ON SOUTHERN EDGE OF SHORTWAVE TROUGH IS STEEPENING MID LEVEL LAPSE RATES. MOST OF SHRA/TSRA KICKED ON WITHIN THE BETTER LR/S AND ALSO ON LEADING EDGE OF H85 FRONTOGENESIS. OTHERWISE ONCE PESKY FOG HELPED OUT BY MOISTURE OFF LK MICHIGAN BURNED OFF...IT HAS BECOME NICE DAY WITH HIGHS TOPPING OUT IN THE 60S AND EVEN SOME LOWER 70S. THAT WILL BE LAST 70 DEGREES FOR POSSIBLY THIS FALL THOUGH AS BIG CHANGES ARE COMING IN ONCE THE LOW OVER MINNESOTA MOVES TO NORTHERN LK SUPERIOR AND COLDER AIR PLOWS INTO THE REGION. THROUGH FRIDAY...DO NOT EXPECT ANY BIG SNOW ACCUMS. WIDESPREAD SNOW ON CYCLONIC SIDE OF SHORTWAVE TROUGH AND IN MOIST/CYCLONIC FLOW BEHIND SFC LOW NEVER REALLY MAKES IT INTO CWA...INSTEAD LIFTING MORE NORTHEAST INTO ONTARIO. INSTEAD...NORTHWEST CWA GRADUALLY GETS INTO A REGIME WITH PLENTIFUL LOW-LEVEL MOISTURE BLO 10KFT AND WSW BLYR WINDS TURNING MORE WESTERLY WITH TIME. SOUNDINGS INDICATE TEMPS IN MOIST LAYER ARE WARMER THAN -8C UNTIL THE DAYTIME ON FRIDAY. UPSHOT IS THAT INITIAL PRECIP TONIGHT INTO FRIDAY MORNING FOR NW CWA WILL BE MAINLY LIGHT RAIN WITH PERHAPS REALLY SMALL SNOW FLAKES MIXING IN AT TIMES LATER TONIGHT. AFTER EARLY EVENING POPS EAST...RESTRICTED POPS FOR LAKE EFFECT/CYCLONIC FLOW MOISTURE TO KEWEENAW OVERNIGHT TONIGHT AS REST OF AREA STAYS IN UNFAVORABLE WSW WINDS IN LOW-LEVELS. WINDS IN BLYR LATE TONIGHT PUSH TOWARD 30 MPH SO EXPECT WINDS NW CWA TO INCREASE LATE. SHOULD BE FAIRLY QUIET OVER REST OF CWA. SKIES MAY EVEN CLEAR OUT SOME IN THE CNTRL AND EAST OVERNIGHT FOR A TIME. A RATHER MISERABLE DAY IS IN STORE FOR KEWEENAW ON FRIDAY. SOUNDINGS SHOW INCREASING DEPTH TO MOISTURE WITH MOISTURE PUSHING COLDER THAN -10C BY AFTN SO SHOULD SEE MORE AND MORE SNOW MIX WITH RAIN THROUGH THE DAY. BLYR TEMPS REMAIN WARM IN THE UPR 30S AND LOWER 40S...SO EVEN IF PRECIP CHANGES TO MOSTLY SNOW DURING THE DAY /WOULD OCCUR BASED ON WBZERO HEIGHTS FALLING WELL BLO 1000 FT AGL/ LITTLE OR NO SNOW ACCUM SHOULD OCCUR DURING THE DAY. BEST CHANCE FOR SEEING SNOW AS ONLY PTYPE WILL BE ON THE HIGHEST TERRAIN OF THE NW CWA. SIMILAR TO TONIGHT...SHOULD BE PRETTY QUIET MOST OTHER AREAS ON FRIDAY MORNING THOUGH A BIT BREEZY. BY FAR...STRONGEST WINDS WILL BE FOUND ON THE KEWEENAW WITH FAVORED WESTERLY WINDS. MIXED LAYER WINDS EASILY TOP OUT OVER 35 KTS AND TOP OF MIXED LAYER WINDS FROM SOUNDINGS SUPPORT GUSTS PUSHING WELL OVER 40 KTS. WINDS ARE ALSO STRONG ALONG LAKE SUPERIOR FROM IWD TO ONTONAGON. FAVORED WEST WIND DIRECTION AND SUCH STRONG WINDS IN MIXED LAYER IN FACE OF STRONG COLD AIR ADVECTION SUPPORTS FREQUENT GUSTS ON FRIDAY OVER HIGHER TERRAIN OF KEWEENAW PENINSULA REACHING WIND ADVY LEVEL /39 KT OR 45 MPH/. WIND ADVY WAS ISSUED FOR KEWEENAW. FOR THOSE OTHER AREAS NEAR LK SUPERIOR ADVY LEVEL WIND GUSTS SHOULD BE NOT AS FREQUENT...SO DID NOT INCLUDE THOSE AREAS IN ADVY AT THIS TIME. BY MID-LATE AFTN ON FRIDAY...925MB-850MB WINDS VEER MORE WNW WHICH SHOULD BRING MORE OF CWA INTO CYCLONIC LOW-LEVEL MOIST FLOW. EXPECT WX REGIME OVER KEWEENAW TO BEGIN TO SHIFT TOWARD HIGHER TERRAIN OF ALL WESTERN AND POSSIBLE NCNTRL CWA BY 21Z. TEMPS MAY ALSO TRY TO FALL OFF FOR THESE AREAS AS WELL. AGAIN...LIKE THE KEWEENAW EVEN WITH MAINLY SNOW VERSUS RAIN...WARMER BLYR TEMPS AND MINIMAL STRONGER LAKE EFFECT CONVECTION SHOULD PROHIBIT MUCH IN WAY OF SNOW ACCUM. BETTER CHANCE FOR SNOW ACCUMS FOR THE CWA WILL OCCUR MORE ON FRIDAY NIGHT WHICH IS NOW ADDRESSED IN THE LONGER TERM DISCUSSION. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 423 PM EDT THU OCT 4 2012 NAM SHOWS A BROAD 500 MB TROUGH ACROSS THE CENTRAL U.S. WITH A RIDGE OFF THE PACIFIC NW AND A CLOSED LOW OFF THE CA COAST IN A REX BLOCK PATTERN WITH A RIDGE OFF THE EAST COAST 00Z SAT. PATTERN DOES NOT CHANGE MUCH WITH A SHORTWAVE OVER THE NORTHERN PLAINS ROTATING AROUND THE TROUGH AND INTO THE LOWER GREAT LAKES ON SUNDAY. BASICALLY...WILL NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. SINCE THIS IS AN EARLY SEASON SNOW...LOT OF THE TOOLS WILL NOT WORK USING THICKNESSES FOR DETERMINING SNOW AND PRETTY MUCH KEPT WHAT WAS ALREADY IN THERE WHICH IS SNOW IN THE HIGHER TERRAIN AND RAIN IN THE LOWER TERRAIN AND EASTERN CWA. DID LOWER SNOW RATIOS THOUGH AS FEELING IS THAT THE SNOW FLAKE SIZE WILL BE SMALL AND LOWER THAN A 10 TO 1 RATIO WILL WORK. THIS STILL GIVES ME 1-3 INCHES IN THE HIGHER TERRAIN FOR FRI NIGHT THROUGH SAT EVENING. IT WILL BE COLD ENOUGH FOR LAKE EFFECT PCPN AND LOWERED THE LAKE TEMPERATURES TO 10C TO 12C FOR FRI NIGHT AND SAT AS THINKING IS THE LAKE WILL START TO GET TURNED OVER AND WATER TEMPERATURES WILL COOL OFF FROM 12C TO 15C THAT IT IS NOW. 850 MB TEMPERATURES COOL TO AROUND -6C BY 12Z SAT AND THAT IS ENOUGH LAKE EFFECT DELTA-T FOR LAKE EFFECT. BY SUNDAY...WINDS SWITCH TO THE SW AND WITH WARM AIR ADVECTION COMING IN...THIS WILL PUSH THE LAKE EFFECT PCPN OFFSHORE OF THE U.P. IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH ACROSS THE CENTRAL AND EASTERN U.S. WITH A RIDGE OFF THE PACIFIC NW AND A CLOSED LOW OFF THE CA COAST IN A REX BLOCK PATTERN 12Z MONDAY. THERE IS A SHORTWAVE ACROSS SOUTH CENTRAL CANADA THAT IS POISED TO DROP INTO THE UPPER GREAT LAKES WITH AN ALBERTA CLIPPER SYSTEM THAT MOVES THROUGH MON NIGHT INTO TUE. THE TROUGH OVER THE CENTRAL AND EASTERN U.S. STAYS ANCHORED OVER THE UPPER GREAT LAKES INTO WED. ANOTHER CLIPPER TYPE SYSTEM LOOKS TO AFFECT THE AREA ON THU. IT LOOKS TO STAY COLDER THAN NORMAL THROUGH THE EXTENDED PERIOD WITH ACTIVE WEATHER. KEPT MIXTURE OF RAIN AND SNOW IN FOR LATE TUE NIGHT INTO WED MORNING WITH NEXT COLD AIR WAVE THAT COMES THROUGH. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 152 PM EDT THU OCT 4 2012 AS A LOW PRESSURE SYSTEM OVER FAR NORTHERN MINNESOTA DRIFTS TO THE N OF LAKE SUPERIOR TONIGHT A COLD FRONT WILL MOVE THROUGH THE AREA. SMALL CHANCE OF TSRA EARLY AT CMX BUT OTHERWISE...EXPECT CONDITIONS TO STAY VFR THROUGH MOST OF TONIGHT. ARRIVAL OF COLDER AIR AND LOW LEVEL MOISTURE WILL LEAD TO LAKE ENHANCED RAIN AND SNOW /IFR CONDITIONS/ DEVELOPING AT CMX LATE TONIGHT INTO FRIDAY. MAINLY MVFR FLYING AT IWD AND SAW WITH MINIMAL LAKE EFFECT PRECIP AS LOW-LEVEL WINDS ARE NOT AS FAVORABLE FOR LK EFFECT PRECIP FOR THOSE LOCATIONS. OTHER MAIN ISSUE NEXT 24 HRS WILL BE VERY STRONG WESTERLY WIND GUSTS 20-30 KTS. ALONG WITH THE WINTRY PRECIP AT CMX ON FRIDAY...WINDS SHOULD EXCEED 40 KTS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 423 PM EDT THU OCT 4 2012 AN INTENSIFYING LOW PRESSURE SYSTEM WILL MOVE NORTH-NORTHEAST FROM CENTRAL MINNESOTA TO THE U.S./CANADIAN BORDER BY THIS AFTERNOON...BEFORE BEING LOCATED JUST NORTH NORTHWEST OF LAKE SUPERIOR BY LATE TONIGHT. THIS WILL LEAD TO INCREASING SOUTHWESTERLY WINDS ACROSS THE LAKE THIS AFTERNOON WITH GALE FORCE GUSTS OF 35-45KTS EXPECTED OVER MAINLY WRN LAKE SUPERIOR THIS AFTERNOON/EVENING...INCREASING TO 45KTS TONIGHT INTO EARLY FRIDAY. THE LOW WILL SHIFT NORTHEAST ON FRIDAY...BUT WILL KEEP A SFC TROUGH OVER LAKE SUPERIOR THROUGH FRIDAY NIGHT. AS THIS SFC TROUGH SLOWLY SLIDES SE ACROSS LAKE SUPERIOR...EXPECT WINDS TO SHIFT TO THE NORTHWEST AND GUSTS UP TO 35KTS AT TIMES. A HIGH PRESSURE RIDGE WILL BUILD OVER THE UPPER GREAT LAKES REGION ON SATURDAY AND SUNDAY...LOWERING WINDS BELOW 25KTS. WINDS COME UP TO 30 KNOTS FOR MON NIGHT AND TUE WITH NEXT CLIPPER TYPE SYSTEM BRINGING IN SOME COLDER AIR. GETS REAL CLOSE TO A GALE THEN WITH A TIGHTER PRESSURE GRADIENT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WIND ADVISORY FROM 7 AM TO 6 PM EDT FRIDAY FOR MIZ001-003. LAKE SUPERIOR... GALE WARNING FROM 6 AM FRIDAY TO 10 AM EDT SATURDAY FOR LSZ267. GALE WARNING FROM 11 PM THIS EVENING TO 10 AM EDT SATURDAY FOR LSZ265-266. GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ FRIDAY FOR LSZ162-240>242. GALE WARNING UNTIL 10 AM EDT SATURDAY FOR LSZ264. GALE WARNING UNTIL 6 AM EDT SATURDAY FOR LSZ263. GALE WARNING FROM 6 AM TO 8 PM EDT FRIDAY FOR LSZ248. GALE WARNING UNTIL 8 PM EDT FRIDAY FOR LSZ243>245. GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT FRIDAY FOR LSZ246-247. LAKE MICHIGAN... GALE WARNING FROM MIDNIGHT TONIGHT TO 2 PM EDT FRIDAY FOR LMZ221- 248-250. && $$ SHORT TERM...JLA LONG TERM...07 AVIATION...JLA MARINE...07
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
355 PM EDT THU OCT 4 2012 .SYNOPSIS... ISSUED AT 354 PM EDT THU OCT 4 2012 A STRONG COLD FRONT WILL CROSS THE AREA THIS EVENING WITH SHOWERS AND SCATTERED THUNDERSTORMS. SKIES WILL CLEAR LATE TONIGHT AND IT WILL TURN COLDER. EXPECT MOSTLY SUNNY SKIES FRIDAY WITH HIGHS ONLY IN THE 50S. LAKE EFFECT RAIN SHOWERS ARE EXPECTED SATURDAY INTO SUNDAY WITH HIGHS MOSTLY IN THE 4OS. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 354 PM EDT THU OCT 4 2012 THE MAIN ISSUE IS THE CONVECTIVE LINE OVER WISCONSIN HEADING TOWARD SOUTHWEST LOWER MICHIGAN AS I WRITE THIS. BEYOND THAT THERE IS THE ISSUE OF LAKE EFFECT RAIN SHOWERS OVER THE WEEKEND. THE COMBINATION OF JET ASSISTED LIFT AND A DEVELOPING LOW LEVEL JET WILL AID THE DEVELOPMENT OF A LINE OF SHOWERS THAT AT 3 PM WAS OVER EASTERN WISCONSIN. AS THIS LINE CROSSES LAKE MICHIGAN I EXPECT THUNDERSTORMS TO DEVELOP WITHIN THAT LINE. AIDING THAT IS A SURGE OF HIGHER SURFACE DEW POINTS JUST AHEAD OF THE COLD FRONT. THE 1000 TO 850 MB MOISTURE TRANSPORT VECTORS INCREASE SIGNIFICANTLY AS THE FRONT CROSSES LAKE MICHIGAN. THE HRRR RUC IS DOING REASONABLY WELL WITH THE CONVECTION ON THE COLD FRONT SO FAR THIS AFTERNOON. SO...BASED ON OUR TIMING TOOL...THE TIMING IN THE HRRR RUC AND RELATED TOOLS I EXPECT A NEARLY SOLID LINE OF SHOWERS AND ISOLATED STORMS TO CROSS THE CWA BETWEEN 6 PM AND 11 PM THIS EVENING. I DO NOT EXPECT SEVERE STORMS AS THE CAPES ARE NOT IMPRESSIVE BUT THERE IS 30 - 40 KNOTS OF DEEP LAYER SHEAR TO WORK WITH. THERE IS ALSO 40 TO 50 KNOTS AS CLOSE TO THE GROUND AS 5000 FT AGL AS THIS LINE MOVES CROSS THE CWA. SO EXPECT GUSTY WINDS WITH THE SHOWERS. ONCE THIS FEATURE MOVES EAST THE STRONG COLD ADVECTION BEHIND THE FRONT WILL RESULT IN CONSIDERABLE SUBSIDENCE SO EXPECT CLEARING SKIES LATER TONIGHT. ANOTHER JET SEGMENT ROTATING THROUGH THE UPPER TROUGH WILL INDUCE A WAVE ON THE FRONT FRIDAY INTO SATURDAY. AT THIS POINT IT SEEMS THE RAIN FROM THAT WILL MOSTLY STAY SOUTH OF THE CWA. IT COULD IMPACT AREAS SOUTH OF I-69 FRIDAY INTO FRIDAY EVENING EVEN SO. I HAVE LOW CHANCE POPS FOR THAT. THE SHORTWAVE TROUGH WITH THE DEEP COLD AIR ROTATES THROUGH THE CWA SATURDAY. THAT WILL RESULT IN LAKE EFFECT RAIN SHOWERS. THANKS TO A NORTH NORTHWEST WIND IN THE BOUNDARY LAYER I EXPECT MOST OF THE SIGNIFICANT SHOWERS TO BE CLOSE TO LAKE SHORE. EVEN SO THE AIR IS UNSTABLE ENOUGH THAT ALL AREAS SHOULD SEE SOME SHOWERS IN THE AFTERNOON. SATURDAY NIGHT THOSE SHOWERS WILL CONTINUE NEAR THE LAKE SHORE BUT SOME CLEARING IS POSSIBLE INLAND. COLD BE A FREEZE EARLY SUNDAY MORNING NORTH AND EAST OF GRR. WE WILL HAVE TO WATCH THAT FOR A POSSIBLE FREEZE WARNING. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 354 PM EDT THU OCT 4 2012 STILL EXPECTING SOME WEAK LAKE EFFECT RAIN SHOWERS INTO SUNDAY... HOWEVER SURFACE RIDGING SHOULD BE BREAKING MUCH OF IT UP THROUGH THE DAY. FROST POTENTIAL LOOKS RATHER GOOD INTO SUNDAY NIGHT AS SKIES CLEAR. WE WILL HAVE TO SEE HOW MUCH MIXING REMAINS OVER THE REGION...WHICH COULD LESSEN THE IMPACTS. THE NEXT RAIN MAKER WILL COME IN THE FORM OF ANOTHER COLD FRONT EXPECTED LATE TUESDAY INTO WEDNESDAY. COULD BE POCKETS OF STEADIER RAINS AS THIS FRONT LOOKS MUCH LIKE THIS EVENING/S FRONT. HAVE LEFT THUNDER OUT HOWEVER AS THE TIMING OF THE FROPA SHOULD BE LATE TUESDAY NIGHT. THE CHILLY AIR WILL SLOWLY LOSE IT/S GRIP ON THE REGION INTO EARLY NEXT WEEK. H8 TEMPS BELOW 0C MOVE EAST OF THE AREA BY MONDAY AFTERNOON SO A SLIGHTLY WARMING TREND IS EXPECTED WITH UPPER 50S AND LOWER 60S FOR MONDAY AND TUESDAY. ANOTHER SHOT OF COOLER AIR IS EXPECTED BEHIND THE TUESDAY NIGHT FRONT...HOWEVER THIS LOOKS TO BE A QUICKER SHOT...WITH H8 TEMPS ALREADY WARMING BY THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 135 PM EDT THU OCT 4 2012 A COLD FRONT WAS CROSSING EASTERN WISCONSIN THIS AFTERNOON AND WILL REACH WESTERN MI THIS EVENING. THERE WILL BE A BRIEF WINDOW FOR THUNDERSTORMS TO OCCUR AS THE FRONT PASSES EACH TAF SITE. ANY STORMS SHOULD BE SCATTERED...SO HAVE ADDED THE MENTION OF VCTS TO ALL SITES. OTHERWISE CONDITIONS ARE EXPECTED TO REMAIN MOSTLY VFR. THERE COULD BE VERY BRIEF MVFR NEAR AND JUST BEHIND THE FRONT. EXPECT THIS TO BE MAINLY ISOLATED POCKETS OF MVFR...SO HAVE NOT ADDED IT TO THE TAFS AT THIS TIME. VFR CONDITIONS WILL CONTINUE INTO FRIDAY AS THE LOW CLOUDS CLEAR LATE TONIGHT. WESTERLY WINDS WILL INCREASE BY MID TO LATE MORNING. && .MARINE... ISSUED AT 354 PM EDT THU OCT 4 2012 I EXTENDED THE SMALL CRAFT ADVISORY INTO SATURDAY NIGHT SINCE WAVE HEIGHTS ARE NOT EXPECTED TO SUBSIDE BELOW 4 FEET UNTIL EARLY SUNDAY MORNING. THE EXPERIMENTAL GREAT LAKES WATER SPOUT FORECAST SHOWS THE BEST SHOT OF WATER SPOUTS AS BEING SATURDAY AS THE DEEPER COLD AIR MOVES IN. I PUT WATER SPOUTS IN THE NEAR SHORE DURING THAT TIME. THE HRRR SUGGEST POSSIBLE NEAR GALE WINDS WITH THE FRONT THIS EVENING THAT WILL HAVE TO BE WATCHED TOO. && .HYDROLOGY... ISSUED AT 354 PM EDT THU OCT 4 2012 RAINFALL WILL BE LIMITED AT BEST OVER THE NEXT WEEK SO EVEN WITH THE RAINS LAST NIGHT I DO NOT SEE ANY SIGNIFICANT FLOODING ISSUES. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ845>849. SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 2 AM EDT SUNDAY FOR LMZ844. && $$ SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...JK AVIATION...JK HYDROLOGY...WDM MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
135 PM EDT THU OCT 4 2012 .SYNOPSIS... ISSUED AT 356 AM EDT THU OCT 4 2012 WE/LL HAVE ONE MORE MILD DAY TODAY BEFORE A STRONG COLD FRONT ARRIVES TOWARD EVENING AND SENDS THE TEMPERATURE FALLING. SHOWERS EARLY THIS MORNING WILL GIVE WAY TO PARTLY SUNNY SKIES BY MID DAY. SOUTHWEST WINDS WILL BOOST TEMPERATURES INTO THE MID 70S. THUNDERSTORMS ARE POSSIBLE NEAR THE COLD FRONT TOWARD EVENING. TEMPERATURES WILL ONLY CLIMB INTO THE 50S THROUGH EARLY NEXT WEEK WITH UPPER 40S EXPECTED SUNDAY. && .UPDATE... ISSUED AT 904 AM EDT THU OCT 4 2012 I UPDATED THE GRIDS AND ZONE FORECAST TO TIME OUT THE RAIN MORE QUICKLY. I USED THE HRRR RUC TO HELP MY CAUSE (10Z VERSION). IT SHOULD BECOME MOSTLY CLEAR BY MID DAY BASED ON SAT LOOPS AND MODEL RH DATA. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 356 AM EDT THU OCT 4 2012 FORECAST CONCERNS DEAL WITH PCPN TRENDS THROUGH THE PERIOD. OVERALL... THE FORECAST HAS NOT CHANGED MUCH. RADAR SHOWS SHOWERS MOVING ACROSS THE CWA. MOST OF THE PCPN WAS NORTH OF I-96 BUT ANOTHER AREA WAS MOVING TOWARD LWR MI AND WAS OVER ERN IL. THESE AREAS OF PCPN ARE ASSOCIATED WITH UPPER WAVES MOVING THROUGH THE GREAT LAKES AND WILL DIMINISH THIS MORNING. WEAK SHORT WAVE RIDGING AHEAD OF THE APPROACHING COLD FRONT WILL RESULT IN SOME SUNSHINE THIS AFTERNOON AND SW WINDS WILL BOOST TEMPS WELL INTO THE 70S. BY LATE IN THE DAY SHOWERS AND SCATTERED STORMS WILL DEVELOP. NCEP AND NSSL WRF MODELS SHOW A LINE OF SHOWERS/STORMS DEVELOPING AROUND 23Z OVER ERN LAKE MICHIGAN AND SWEEPING ACROSS THE CWA DURING THE EVENING. 00Z MODELS SHOW A LITTLE STRONGER INSTABILITY THAN PREVIOUS RUNS. IN FACT SHEAR VALUES NEAR 40 KTS SUGGEST THAT A FEW OF THE STORMS COULD PRODUCE STRONG WINDS. MID LEVEL WINDS NEAR 50 KTS WILL PUSH THE LINE EWD QUICKLY AND SHOULD BE MOSTLY EAST OF THE CWA BY 06Z. FRIDAY LOOKS GENERALLY DRY EXCEPT FOR THE FAR SE CWA CLOSER TO THE FRONTAL BOUNDARY. CERTAINLY COOLER THOUGH WITH HIGHS IN THE 50S. UPPER TROUGH WILL BE SWINGING THROUGH SATURDAY WITH STRONG DPVA. SCT SHOWERS EXPECTED ACROSS THE CWA. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 356 AM EDT THU OCT 4 2012 LONG TERM BEGINS WITH AN UPPER TROUGH OVERHEAD AND LAKE EFFECT RAIN SHOWERS ONGOING OFF OF LAKE MICHIGAN IN NORTHWEST FLOW. SATURDAY NIGHT SHOULD FEATURE PLENTY OF SHOWER ACTIVITY OFF THE LAKE WITH DELTA T/S AROUND 20 DEG C. NOT OUT OF THE REALM OF POSSIBILITIES OF SEEING A LITTLE LIGHT SNOW MIX IN AWAY FROM LAKE MICHIGAN ACROSS CENTRAL LOWER MICHIGAN SATURDAY NIGHT INTO SUNDAY MORNING. DO NOT HAVE SNOW IN THE FORECAST AT THIS POINT. FEEL SUNDAY WILL TRY TO DRY OUT...AS THE MOISTURE WANES. STILL HAVE A CHANCE FOR SHOWERS IN THE FORECAST THOUGH WITH DELTA T/S HOLDING AROUND 20 DEGREES. SUNDAY NIGHT THROUGH MONDAY NIGHT HAVE A DRY FORECAST IN PLACE AS A SURFACE RIDGE FLOATS THROUGH THE REGION. RAIN CHANCES INCREASE TUESDAY NIGHT INTO WEDNESDAY AS A SHORTWAVE TROUGH ROTATES THROUGH THE FLOW. BELOW NORMAL TEMPS SUNDAY AND MONDAY RETURNING BACK TO NORMAL ON TUESDAY. COLD AIR PUSHES BACK INTO THE GREAT LAKES FOR WEDNESDAY. AS IS TYPICAL IN THE FALL...TEMPS WILL BE UP AND DOWN IN THE LONG TERM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 135 PM EDT THU OCT 4 2012 A COLD FRONT WAS CROSSING EASTERN WISCONSIN THIS AFTERNOON AND WILL REACH WESTERN MI THIS EVENING. THERE WILL BE A BRIEF WINDOW FOR THUNDERSTORMS TO OCCUR AS THE FRONT PASSES EACH TAF SITE. ANY STORMS SHOULD BE SCATTERED...SO HAVE ADDED THE MENTION OF VCTS TO ALL SITES. OTHERWISE CONDITIONS ARE EXPECTED TO REMAIN MOSTLY VFR. THERE COULD BE VERY BRIEF MVFR NEAR AND JUST BEHIND THE FRONT. EXPECT THIS TO BE MAINLY ISOLATED POCKETS OF MVFR...SO HAVE NOT ADDED IT TO THE TAFS AT THIS TIME. VFR CONDITIONS WILL CONTINUE INTO FRIDAY AS THE LOW CLOUDS CLEAR LATE TONIGHT. WESTERLY WINDS WILL INCREASE BY MID TO LATE MORNING. && .MARINE... ISSUED AT 356 AM EDT THU OCT 4 2012 EXPANDED THE SCA TO INCLUDE THE ENTIRE NEARSHORE AREA. GUSTY SOUTHWEST WINDS AHEAD OF THE COLD FRONT EXPECTED THIS AFTERNOON WILL BOOST WAVES TO 5-7 FT NORTH OF GRAND HAVEN. WINDS WILL SHIFT TO THE NORTHWEST BY EARLY EVENING. && .HYDROLOGY... ISSUED AT 356 AM EDT THU OCT 4 2012 QPF LESS THAN A QUARTER INCH WILL NOT SIGNIFICANTLY IMPACT AREA RIVERS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT FRIDAY FOR LMZ845>849. SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT FRIDAY FOR LMZ844. && $$ UPDATE...WDM SYNOPSIS...93 SHORT TERM...93 LONG TERM...DUKE AVIATION...JK HYDROLOGY...93 MARINE...93
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1236 PM CDT THU OCT 4 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Short Term (Today through Saturday Night)... 08Z surface analysis shows well defined cold front has pushed into far NW MO. Earlier surface based convection has long since dissipated, with pockets of post frontal elevated convection having a better go at it between Omaha to north central KS. RAP soundings show that modest elevated instability (100-300 J/Kg CAPE) will overspread NE KS and NW MO toward daybreak, supporting scattered showers and perhaps a few thunderstorms. Today: Precipitation won`t be the only issue to contend with as the temperature forecast will be equally, if not more challenging. High resolution models show that the frontal speed and cold advection will slow with time due to a combination of daytime mixing and a shift of post frontal precipitation toward the northeast. Southerly winds and weak moisture advection were providing a mild start across the warm sector, and so it seems likely that temperatures will quickly rebound to near yesterday`s maxes, with mid to upper 70s likely over mid Missouri under abundant sunshine. Across the front in far northwest Missouri, strong cold advection and cloud cover suggest that effective highs may be reached at 12Z with only a modest afternoon recovery in the wake of morning convection. It`s possible that my 60F highs here may be perhaps generous. In between these extrema, the forecast is even more nebulous as highs could be reached mid-late morning with temps steady or slowly falling in the afternoon depending on the offset between cold advection and daytime heating. With respect to POPs, the orientation of the frontal axis and elevated instability axis is reflected in keeping scattered shra/-tsra mainly north of a Kansas City to Kirksville axis for today. Coverage will be limited by weakening ascent and ambient dry mid level air, so 30-40 POPs look kosher. Tonight: The surface front should eventually fizzle just southeast of the CWA this evening as large scale height falls finally arrive from the northwest. The arrival of stronger mid level flow will help sharpen a deep layer thermal gradient, with model cross sections showing a classic strengthening of layered/tilted frontogenesis beneath the mid-upper jet cores. Condensation pressure deficits indicate a fairly rapid top-down saturation this evening along and south of a Kansas City-Kirksville line, with some convective instability present as well. Thus, expect a blossoming of an axis of showers embedded thunder between 00 and 06Z over the srn half of the CWA, or perhaps a resurgence of whatever lingers from the daytime hours. Have increased POPs to around 60 percent for areas south of the MO river and brought POPs back toward the northwest overnight. Temperatures will steadily fall via strong cold advection and evaporative cooling, leading to some very raw conditions where precipitation is ongoing. Friday: This process should continue through the daytime Friday with bands of mainly light rain persisting ahead of the large upper trough axis still to the north and west. Surface pressure rises will continue under moderate cold advection, leading to some pretty miserable conditions as temperatures struggle to break the 50 degree mark. Friday Night-Saturday: Layered frontogenesis should slowly shift south and east, allowing precipitation to gradually end from the northwest. Extensive cloudiness and perhaps even some drizzle will linger as the deepening longwave trough still remains well northwest of the area. Mid-high level RH values confirm this idea, and again temperatures will run some 20+ degrees below normal. Saturday Night: With the passage of the upper trough, skies should clear, coincident with the arrival of the surface ridge axis. Temperatures will likely plummet after midnight, with near certainty that the coldest night of the early autumn season is upon us. Widespread frost looks almost a given and some sheltered areas across NW Missouri could dip below freezing for an hour or two. Bookbinder Medium Range (Sunday through Wednesday)... Cool temperatures will still be prevailing as the end of the weekend arrives, though some moderation is in store for the work week. A pronounced trough will still be in control of the weather across the Plains, pushing a cold Canadian surface high through the Lower Missouri River Valley. The consensus amongst the medium range models is for the trough pushing this cold air to continue dominating the weather across the eastern half of the nation through the work week. However, with a series of shortwaves expected to drop into, and then move through this broader longwave feature, it wont be all cold air advection for next week. For Sunday, the center of the cold Canadian surface high will be sliding off to our east, allowing the first hints at a return flow to develop by late in the day. The return flow that will be in place by Monday should allow afternoon readings to jump back into the 60s, with that temperature range expected to persist through at least the middle of the work week. This temperature regime will also support overnight lows in the 40s, so any weekend frost issues are not expected to persist into the work week at this time. Otherwise, have continued to carry some silent slight chance POPs from Tuesday into Tuesday night. Several models advertise a shortwave rotating through the broader trough in that time period. Warm air advection on the back side of the exiting surface high, ahead of another weak frontal boundary, could squeeze some drops from the air. But, given the many questions on timing and moisture availability have opted to leave the POPs in the silent slight chance range. Otherwise, consensus model output inserted more POPs for Wednesday. These did not look reasonable given the surface high expected to be shifting through the Plains States during that period, so have yanked them out. Cutter && .AVIATION... For the 18Z TAFs...a cold front has moved through the terminals this morning veering winds to the north this afternoon. Gusty winds behind the front will subside over the next few hours. Showers and scattered thunderstorms have also developed behind the front this morning but have begun to diminish however...a few light showers will still be possible in the VC of the terminals over the next few hours as well. For this afternoon expect continued north winds around 7-10kts with bkn mid level clouds around 7-8kft. Tonight showers will develop southwest of the terminals and move northeastward into the MKC and MCI by 02Z-03Z and continue through 09Z...however no cig/vis restrictions are expected. Showers will shift south of the terminals by tomorrow morning with continued bkn mid level clouds. 73 && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
121 PM CDT THU OCT 4 2012 .AVIATION...18Z KGRI TAF...PREVAILING VFR CONDITIONS ARE EXPECTED AT KGRI FOR THE NEXT 24 HOURS. WHILE VFR CIGS AND VISIBILITIES WILL PREVAIL...EXPECT CLOUDS TO THICKEN AND LOWER SOME OVERNIGHT IN RESPONSE TO AN APPROACHING DISTURBANCE...WITH CIGS REACHING ABOUT 5KFT BY DAYBREAK FRIDAY. WHILE THERE MAY BE A STRAY LIGHT SHOWER ASSOCIATED WITH THIS DISTURBANCE...CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN TAF AT THIS TIME. OTHERWISE...GUSTY NORTHERLY WINDS WILL CONTINUE AT THE TERMINAL FOR THE NEXT FEW HOURS...WITH WINDS SUBSIDING TO AROUND OR BELOW 10KTS OVERNIGHT...AS AN AREA OF SURFACE HIGH PRESSURE NUDGES DOWN FROM THE NORTH. && .PREV DISCUSSION... /ISSUED 800 AM CDT THU OCT 4 2012/ UPDATE...SENT AN UPDATE TO THE FORECAST TO REMOVE THE CHANCE OF THUNDER ACROSS SOUTHEASTERN PORTIONS OF THE FORECAST AREA OVER THE NEXT FEW HOURS...AS INSTABILITY AXIS IS PUSHING FURTHER EAST AND ONLY A LIGHT SHOWER OR SPRINKLE CAN BE EXPECTED OVER THE NEXT COUPLE OF HOURS. OTHERWISE...NO ADDITIONAL CHANGES MADE TO PREVIOUS FORECAST AT THIS TIME. PREV DISCUSSION... /ISSUED 451 AM CDT THU OCT 4 2012/ SHORT TERM...THROUGH SATURDAY NIGHT. ALTHOUGH CHANCES OF LEGITIMATE...WIDESPREAD MEASURABLE PRECIPITATION WITHIN THE CWA DURING THE NEXT 72 HOURS ARE GENERALLY QUITE LOW...THE FORECAST PRESENTS PLENTY OF CHALLENGES PRIMARILY IN THE OVERNIGHT LOW TEMPERATURE DEPARTMENT...WITH THE ULTIMATE QUESTION EACH OF THE NEXT 3 NIGHTS BEING JUST HOW COLD WILL IT ACTUALLY GET...AS IT COULD BE A DICEY BATTLE BETWEEN A VERY COOL AIRMASS AND CLOUD COVER TRYING TO HOLD SOME AREAS UP A BIT. FOR NOW HAVE HELD OFF ON ANY FROST/FREEZE HEADLINES...BUT WILL CONTINUE TO HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK. STARTING OFF RIGHT AWAY THIS MORNING...AS I TYPE A SOMEWHAT SURPRISINGLY STRONG THUNDERSTORM WITH CONFIRMED PENNY/NICKLE HAIL IS QUICKLY SLIDING EAST ACROSS JEWELL COUNTY KS...AND SHOULD BE EXITING THE CWA WITHIN THE NEXT HOUR. EARLIER IN THE NIGHT...A FEW OTHER STRONG STORMS LIKELY WITH SMALL HAIL ALSO AFFECTED NEB ZONES INCLUDING BOTH THE FRANKLIN/MERRICK COUNTY AREAS. OTHERWISE...THE VAST MAJORITY OF THE CWA IS DRY AT THIS HOUR...WITH STEADY NORTHWEST WINDS OF 15-20 MPH AND HIGHER GUSTS SERVING AS THE MAIN PRE-DAWN ISSUE...ALTHOUGH THE SPORADIC ADVISORY LEVEL SUSTAINED SPEEDS OF 30+ MPH THAT WERE BEING REPORTED A FEW HOURS AGO HAVE LARGELY TAMED DOWN A BIT. 08Z OBJECTIVE SURFACE ANALYSIS PUTS THE LEADING EDGE OF THIS FIRST TRULY STRONG COLD FRONT OF THE FALL SEASON ALONG A LINE FROM SOUTH CENTRAL KS TO WESTERN IA...HAVING PASSED THROUGH THE ENTIRE CWA. THIS FRONT IS TRAILING FROM A 1005MB LOW OVER CENTRAL MN...WITH GUSTY NORTHWEST WINDS BEING POWERED BY CONTINUED MODEST PRESSURE RISES WELL TO THE SOUTHEAST OF AN EXPANSIVE 1036MB HIGH CENTERED OVER THE MT AREA. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRMS STRENGTHENING ZONAL FLOW ACROSS THE CENTRAL PLAINS...ALONG THE SOUTHERN PERIPHERY OF A STRONG MID LEVEL VORT MAX SWINGING EAST ACROSS THE DAKOTAS INTO MN. FOR THE FIRST FEW HOURS THROUGH SUNRISE THIS MORNING...HAVE LINGERED A SCATTERED THUNDERSTORM MENTION ACROSS SEVERAL FAR EASTERN/SOUTHEAST COUNTIES TO ACCOUNT FOR ONGOING ACTIVITY. THESE SHOWERS/STORMS ARE GENERALLY TIED TO A STRONG ZONE OF FRONTOGENESIS IN THE 850-700MB LAYER...AND ACCORDING TO 08Z MESOSCALE ANALYSIS ARE TAKING FULL ADVANTAGE OF ONLY AROUND 500 J/KG OF ELEVATED CAPE...BUT WITH INCREASING DEEP-LAYER 0-6KM SHEAR NOW UP INTO THE 30-40KT RANGE. WOULD EXPECT A CONTINUED THREAT OF HAIL UP TO THE PENNY-ISH SIZE RANGE AS LONG AS THIS CONVECTION CONTINUES TO LINGER IN SOUTHEAST ZONES EARLY THIS MORNING. GETTING INTO THE OFFICIAL DAYTIME 12Z-00Z PERIOD...AT LEAST FOR NOW CONTINUED TO LINGER A SCATTERED SHOWER/STORM MENTION IN A HANDFUL OF FAR SOUTHEAST COUNTIES THROUGH 15Z...BUT ACCORDING TO REFLECTIVITY TRENDS FROM THE 06Z HRRR THIS IS PROBABLY BEING PLENTY GENEROUS...AS MOST CONVECTION SHOULD FINALLY BE OUT OF THE CWA BY SUNRISE OR SO. ONCE THIS ONGOING PESKY STRONG CONVECTION GETS OUT OF HERE...THE MAJORITY OF THE DAY SHOULD BE FAIRLY UNEVENTFUL AND DRY WITHIN THE CWA...WITH SKIES FOR MOST OF THE DAY AVERAGING NO WORSE THAN PARTLY CLOUDY IF NOT MOSTLY SUNNY. IT GOES WITHOUT SAYING THAT THOSE NOT PAYING ATTENTION THE LAST FEW DAYS WILL BE CAUGHT OFF GUARD BY THE 25-30 DEGREE DROP IN TEMPS FROM YESTERDAY. KEPT HIGHS SIMILAR TO PREVIOUS FORECAST...BUT BASED ON EXPECTATION OF SOME SUN AND DECENT MIXING...ACTUALLY NUDGED UP MOST AREAS 1-2 DEGREES...BUT STILL KEEPING NEARLY ALL AREAS A FEW DEGREES EITHER SIDE OF 60. ALTHOUGH WINDS WILL REMAIN QUITE BREEZY THIS MORNING WITH GUSTS OF AT LEAST 25-30 MPH STILL COMMON...A STEADY DECREASING TREND WILL CONTINUE THROUGH THE DAY WITH SUSTAINED SPEEDS THIS AFTERNOON AVERAGING AROUND 15 MPH OR LOWER. TONIGHT...NORTH-NORTHEAST BREEZES OF NO MORE THAN 5-10 MPH WILL PREVAIL CWA-WIDE AS SURFACE HIGH PRESSURE SETTLES DEEPER INTO THE REGION. HOWEVER...CLOUD TRENDS WILL PROVE TRICKY...AS THE REGION COMES UNDER INCREASING UPPER LEVEL JET ENTRANCE REGION DYNAMICS AS A BROAD TROUGH CONTINUES SETTLING INTO THE CENTRAL/NORTHERN PLAINS. ALTHOUGH THE FORECAST FOR TONIGHT WAS LEFT VOID OF PRECIP MENTION...ISENTROPIC LIFT EVIDENT AROUND THE 700MB LEVEL SHOULD PROMOTE A STEADILY EXTENDING BAND OF MID LEVEL CLOUDS ACROSS MOST OF THE CWA ESPECIALLY AFTER MIDNIGHT...WITH THE BEST POTENTIAL FOR PRECIP REMAINING WEST OF THE CWA. HOWEVER...CERTAINLY CANNOT RULE OUT A FEW SPRINKLES LATE TONIGHT ESPECIALLY IN SOUTHERN ZONES BUT WILL KEEP EVEN THIS MENTION OUT FOR NOW. ALTHOUGH MET/MAV GUIDANCE CAME IN QUITE CHILLY FOR TONIGHTS LOWS...OPTED TO KEEP THE OFFICIAL FORECAST AT LEAST 3 DEGREES ABOVE THIS GUIDANCE CONSENSUS IN MOST AREAS TO ACCOUNT FOR EXPECTATION OF INCREASING CLOUDS THROUGH THE NIGHT. THIS YIELDED A SLIGHTLY WARMER LOW TEMP FORECAST THAN PREVIOUS...BUT STILL BRINGS MOST NEB ZONES INTO THE LOW-MID 30S...BUT RANGING FROM UPPER 20S FAR NORTH TO UPPER 30S IN MOST KS ZONES. ALTHOUGH A MARGINAL FREEZE AND/OR PATCHY FROST IS VERY POSSIBLE TONIGHT ACROSS MOST NEB ZONES...THE UNCERTAINTY IN HOW MUCH CLOUD COVER COULD HOLD THINGS UP...ALONG WITH THE FACT THAT THE NEXT FEW NIGHTS SHOULD BE EVEN COLDER...HAS KEPT ME FROM ISSUING A FORMAL FROST/FREEZE HEADLINE FOR TONIGHT AT THIS TIME. FRIDAY DAYTIME...SUBTLE SHORTWAVE ENERGY CONTINUES TO TRACK WEST- EAST ACROSS THE CWA UNDERNEATH ONE OF THE STRONGER...MOST PERSISTENT UPPER LEVEL JETS SEEN IN AWHILE. PERSISTENT MID LEVEL LIFT UNDERNEATH THIS JET CORE SHOULD KEEP PLENTY OF MID-HIGH CLOUDS AROUND DURING THE DAY. AS FOR RAIN CHANCES...CONVERTED ZONE FORECAST WORDING TO SLIGHT CHANCE OF LIGHT RAIN ACROSS MOST OF THE CWA...WITH THE OVERALL BEST RISK FOR POSSIBLY A FEW HUNDREDTHS TARGETING THE SOUTHWEST 1/2 OF THE AREA. IF THE LOW LEVEL THERMAL PROFILE SETS UP JUST RIGHT...SUPPOSE A FEW SNOWFLAKES ARE POSSIBLE DURING THE MORNING IN THE WEST AROUND THE DAWSON COUNTY AREA...BUT WITH LIGHT RAIN MORE LIKELY TO DOMINATE HAVE LEFT THIS AS THE ONLY PRECIP TYPE MENTION FOR NOW. FOR HIGH TEMPS NUDGED UP EASTERN ZONES VERY SLIGHTLY BUT OTHERWISE LITTLE CHANGE WITH HIGHS IN MOST AREAS ONLY LOW-MID 50S BUT MAYBE ONLY UPPER 40S IN PARTS OF THE WEST. FRIDAY NIGHT...A MID LEVEL SHORTWAVE OVER THE DAKOTAS WILL SINK SOUTH TOWARD THE REGION...AS FAST ZONAL FLOW CONTINUES IN THE UPPER LEVELS. LINGERED A SLIGHT CHANCE OF LIGHT RAIN IN FAR SOUTHERN/SOUTHWEST ZONES THROUGH THE NIGHT...BUT THE LATEST TRENDS HAVE BEEN FOR THE VAST MAJORITY OF THE CWA TO STAY DRY THROUGH THE NIGHT WITH THE MAIN FOCUS FOR RAIN OR A RAIN-SNOW MIX HOLDING JUST WEST OF THE CWA. AGAIN...CLOUD TRENDS WILL PROVE VERY TRICKY REGARDING HOW COLD IT GETS...AS EXPECT A GRADIENT RANGING FROM MORE CLEAR IN THE NORTHEAST TO MORE CLOUDY IN THE SOUTHWEST. SOME OF MET/MAV GUIDANCE CAME IN QUITE COLD...AND ALTHOUGH DID NOT GO QUITE AS LOW AS THIS GUIDANCE...DID LOWER LOWS A SOLID 2-5 DEGREE FROM PREVIOUS FORECAST...NOW PUTTING MOST AREAS NORTH OF HIGHWAY 6 DOWN IN THE 20S AND AREAS SOUTH INTO KS MAINLY LOW-MID 30S. AS A RESULT...UNLESS CLOUD WREAK HAVOC...MUCH OF THE NORTHERN 1/2 OF THE CWA SHOULD REALIZE ITS FIRST HARD FREEZE OF THE SEASON...WITH FREEZE HEADLINES A DECENT BET DURING THE NEXT FEW FORECAST CYCLES. SATURDAY DAYTIME...THE AFOREMENTIONED SHORTWAVE TO THE NORTH DROPS SOUTH OVER NEB...BUT WITH ANY APPRECIABLE FORCING FOR LIGHT PRECIP STILL ONLY SKIRTING THE FAR SOUTHWESTERN CWA...WHERE A SLIGHT CHANCE OF LIGHT RAIN WAS MAINTAINED. OTHERWISE...NUDGED UP HIGHS VERY SLIGHTLY MOST AREAS BASED ON LATEST GUIDANCE CONSENSUS...BUT WITH MOST AREAS ONLY LOW-MID 50S AND UPPER 40S SOUTHWEST. FINALLY FOR SATURDAY NIGHT...CONFIDENCE IS FAIRLY HIGH THAT IT WILL BE DRY CWA-WIDE...AND GENERALLY CLEARER THAN BOTH TONIGHT/FRIDAY NIGHT AS THE MAIN MID LEVEL WAVE DEPARTS SOUTHEAST TOWARD MO. FOR THOSE AREAS THAT DO NOT HARD-FREEZE FRIDAY NIGHT...SATURDAY NIGHT IS STILL EXPECTED TO PRETTY MUCH PUT THE NAIL IN THE COFFIN ON THE GROWING SEASON...WITH MOST IF NOT OF THE CWA SETTLING AT LEAST INTO THE MID-UPPER 20S. IF THINGS GO AS CURRENTLY ENVISIONED...FRIDAY NIGHT COULD FEATURE THE LAST FREEZE WARNING OF THE SEASON IN ROUGHLY THE NORTHERN 1/2 OF THE CWA...WITH THE SOUTHERN 1/2 LIKELY BEING FINISHED OFF SATURDAY NIGHT. AS ALREADY STATED SEVERAL TIMES THOUGH...MID LEVEL CLOUD TRENDS COULD POTENTIALLY THROW IN A WRENCH IN THESE PLANS HOWEVER...ESPECIALLY IF THEY HOLD UP LOWS HIGHER THAN EXPECTED FRIDAY NIGHT. LONG TERM...STARTING 12Z SUNDAY. LONG TERM GUIDANCE SUGGESTS NORTHWESTERLY TO QUASI-ZONAL MID AND UPPER LEVEL FLOW WILL PERSIST OVER THE CENTRAL PLAINS DURING THE LONG TERM FORECAST PERIOD. A PAIR OF MID LEVEL SHORTWAVES ARE ALSO EXPECTED TO PUSH ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY DURING THE LONG TERM FORECAST PERIOD...ONE DURING THE DAY MONDAY AND THE OTHER ON TUESDAY. BEFORE THE PASSAGE OF THESE MID LEVEL SHORTWAVES HOWEVER...SOUTHERLY LOW LEVEL FLOW AND RESULTANT WARM AIR ADVECTION SHOULD PRESENT A WARMING TREND BOTH SUNDAY AND MONDAY. THE INITIAL MID LEVEL SHORTWAVE ON MONDAY IS THEN EXPECTED TO PROMOTE SURFACE CYCLOGENESIS OVER SOUTHERN ONTARIO...WITH AN ASSOCIATED COLD FRONT EXPECTED TO SWEEP SOUTH/SOUTHEAST ACROSS THE CENTRAL PLAINS EARLY TUESDAY. THE SECOND MID LEVEL SHORTWAVE ON TUESDAY IS THEN EXPECTED TO PROVIDE A REINFORCING SHOT OF LOW LEVEL COLD AIR ADVECTION TO THE AREA TUESDAY NIGHT INTO WEDNESDAY MORNING WITH THE OPERATIONAL GFS...EC AND GEFS-MEAN ALL SUGGESTING A ~1025MB SURFACE HIGH WILL SET UP SHOP NEAR OR OVER OUR AREA BY 12Z WEDNESDAY. GIVEN ALL THIS...WENT AHEAD WITH A COOLING TREND IN TEMPERATURES TUESDAY AND WEDNESDAY. DESPITE THE PASSAGE OF THESE LOW LEVEL BAROCLINIC ZONES...OVERALL KINEMATIC FORCING APPEARS WEAK THROUGHOUT THE LONG TERM FORECAST. IN ADDITION...FORECAST PROXIMITY SOUNDINGS FROM ACROSS THE CWA PER THE OPERATIONAL GFS AND EC SUGGEST TROPOSPHERIC MOISTURE WILL BE FAIRLY LACKING DURING THIS SAME TIME PERIOD. GIVEN ALL THIS...THE LONG TERM FORECAST PERIOD REMAINS DRY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE/AVIATION...ROSSI SHORT TERM...PFANNKUCH LONG TERM...BRYANT
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1145 AM MDT THU OCT 4 2012 .AVIATION... 18Z TAF CYCLE STRONGEST WINDS HAVE ALREADY OCCURRED ACROSS THE EASTERN PLAINS SUCH AS AT TCC SO LOOK FOR A CONTINUED LOWERING THIS AFTERNOON. LOW CLOUDS ACROSS THE EAST CENTRAL PLAINS WITH DECKS AROUND 3000 FEET WILL QUICKLY ERODE AWAY DURING THE NEXT 30 TO 60 MINUTES BASED ON SATELLITE TRENDS. THIS WILL GIVE WAY TO VFR CONDITIONS PRETTY MUCH AREAWIDE THROUGH THE NEXT 24 HOURS. IT SHOULD BE POINTED OUT THAT THE WEATHER MODELS ARE PAINTING A POSSIBLE LOWER CLOUD INTRUSION NEAR TO THE TEXAS STATE LINE BY 12Z FRIDAY MORNING AND THAT TREND WILL HAVE TO BE WATCHED AS FAR AS IMPACT TO TCC. WILL NOT PUT ANY LOW CLOUD WORDING IN THE TERMINAL FORECAST AT THIS TIME. 50 && .PREV DISCUSSION...944 AM MDT THU OCT 4 2012... LATEST OBS AND RUC13 GUIDANCE SHOW SURFACE PRESSURE RISES DECREASING OVER THE E PLAINS THEREFORE HAVE ALLOWED WIND ADV TO EXPIRE ON TIME FOR CURRY AND ROOSEVELT COUNTIES. NORTH TO NORTHEAST WINDS 20 TO 30 MPH WILL GRADUALLY DIMINISH AND VEER TO THE SOUTH AND SOUTHEAST AS THE DAY PROGRESSES. GUYER .PREV DISCUSSION...341 AM MDT THU OCT 4 2012... AT 00Z...A DRY ATMOSPHERE CONTINUED ACROSS THE AREA WITH THE KABQ UPPER AIR SOUNDING SHOWING A PWAT OF 0.37 INCH...OR ROUGHLY 80% OF NORMAL. AT 09Z...LATEST SURFACE OBS AND SATELLITE IMAGERY SHOWING EVIDENCE OF MOUNTAIN WAVE ACTION ACROSS CENTRAL AND WESTERN AREAS...WITH A COLD FRONT BARRELING DOWN THE EASTERN PLAINS. THE FRONT WAS LOCATED ALONG A CLOVIS TO SANTA ROSA TO NEAR LAS VEGAS LINE. BEHIND THE FRONT...NORTHERLY WINDS WERE GUSTING TO BETWEEN 40 AND 50 MPH. MUCH COOLER CONDITIONS ARE FORECAST TODAY ACROSS THE EASTERN PLAINS BEHIND THE FRONT...WITH HIGHS 15 TO 25 DEGREES BELOW WEDNESDAY`S AND GENERALLY 5 TO 10 DEGREES BELOW NORMAL. CONTRAST THIS WITH CENTRAL AND WESTERN PORTIONS OF THE AREA WHERE HIGHS WILL BE AN AVERAGE 10 DEGREES ABOVE NORMAL...ALTHOUGH NOT QUITE AS WARM AS YESTERDAY. THIS FRONT IS NOT FORECAST TO PUSH THROUGH THE CENTRAL MOUNTAIN CHAIN...INSTEAD BREEZY WESTERLY WINDS ARE EXPECTED TO MIX DOWN TO THE SURFACE CENTRAL AND WEST TODAY WITH THE FRONT RETREATING EASTWARD OVERNIGHT. ANOTHER DRY...BREEZY AND WARM DAY IS FORECAST FRIDAY WITH HIGHS ABOVE NORMAL EXCEPT FOR ACROSS THE NORTHEAST PLAINS WHERE THE FIRST FRONT WILL BE REINFORCED BY A SECOND...MORE SIGNIFICANT FRONT. THIS SECOND FRONT IS FORECAST TO PUSH DOWN THE EASTERN PLAINS FRIDAY NIGHT AND THEN WEST THROUGH THE CENTRAL MOUNTAIN CHAIN EARLY SATURDAY MORNING. THIS SECOND FRONT PRESENTS A COUPLE FORECAST CHALLENGES. THE FIRST CHALLENGE IS PRECIPITATION TYPE GIVEN STRONG COLD AIR ADVECTION AND UPSLOPE FLOW. 00Z MODEL FORECAST SOUNDINGS SUGGEST AREAS OF DRIZZLE OR VERY LIGHT RAIN ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN TO THE TEXAS BORDER...EXCEPT FOR PATCHY FREEZING DRIZZLE ACROSS THE NORTHEAST HIGHLANDS...JOHNSON MESA AND NORTHEAST PLAINS. MODEL QPF IS A FEW HUNDREDTHS OF AN INCH OR LESS. THERE DOES NOT APPEAR TO BE SUFFICIENT MOISTURE IN THE ICE GENERATION REGION OF THE ATMOSPHERE FOR SNOW OR SLEET TO BE MUCH OF A CONCERN. GIVEN VERY WARM TEMPERATURES OF THE PAST FEW DAYS...ANY FREEZING DRIZZLE THAT DEVELOPS LATE FRIDAY NIGHT INTO SATURDAY MORNING WILL LIKELY HAVE LITTLE IMPACT. THE SECOND FORECAST CHALLENGE IS WITH EAST CANYON/GAP WINDS ALONG THE RIO GRANDE VALLEY EARLY SATURDAY MORNING THROUGH SUNDAY. THE MODEL SOLUTIONS ALL SHOW AN IMPRESSIVE EAST TO WEST PRESSURE GRADIENT WITH GOOD RUN-TO-RUN CONSISTENCY. CONFIDENCE IS HIGH ON AN EAST WIND EVENT...BUT THE TIMING OF THE STRONGEST WINDS IS STILL UNCERTAIN. AT THIS TIME...THE STRONGEST WINDS APPEAR TO DEVELOP SATURDAY EVENING AND PERSIST THROUGH EARLY SUNDAY MORNING. A WIND ADVISORY MAY BECOME NECESSARY. TEMPERATURE WISE...A SIGNIFICANT COOL-DOWN IS FORECAST WITH THIS FRONT...WITH HIGH TEMPERATURES IN THE 40S AND 50S ACROSS THE EASTERN PLAINS SATURDAY. COOLER TEMPERATURES WILL SPREAD WEST BEHIND THE FRONT SATURDAY INTO SUNDAY WITH BELOW NORMAL TEMPERATURES FORECAST ACROSS MOST OF OUR AREA SUNDAY. TEMPERATURES WILL MODERATE EARLY NEXT WEEK WITH WARM AIR ADVECTION IN ADVANCE OF AN EASTWARD PROGRESSING UPPER LOW. THE 00Z ECMWF AND GFS SOLUTIONS ARE IN GOOD AGREEMENT WITH THIS FEATURE... POSITIONING IT NEAR SOCAL BY 12Z NEXT THURSDAY. PRECIP CHANCES WILL CREEP IN THE FORECAST AROUND MID WEEK...BUT THE BETTER CHANCES WILL LIKELY BE DELAYED UNTIL LATE WEEK WITH THE UPPER LOW ON SLOW APPROACH. 11 .FIRE WEATHER... SHALLOW BUT QUITE VIGOROUS BACK DOOR FRONT RACING SOUTH THROUGH THE FAR EASTERN PLAINS EARLY THIS MORNING. THIS FRONT IS NOT EXPECTED TO MAKE MUCH PROGRESS WEST OF THE CENTRAL HIGHLANDS. DRAMATIC COOLING HAS FOLLOWED THE FRONT PASSAGE FROM THE NORTHEAST PLAINS SOUTHWARD TO THE EAST-CENTRAL PLAINS WHERE TEMPERATURES HAVE ALREADY FALLEN 15 TO 20 DEGREES. THE SURFACE HIGH PRESSURE ASSOCIATED WITH THE FRONT IS EXPECTED TO SHIFT EAST FAIRLY QUICK AND SO WINDS WILL GRADUALLY BECOME SELY BY AFTERNOON. WEST OF THE CENTRAL HIGHLANDS...BREEZY TO LOCALLY WINDY CONDITIONS WILL DEVELOP ONCE AGAIN THIS AFTERNOON. THE WINDS WILL BE MORE WEST/SOUTHWEST. A STRONGER BACK DOOR COLD FRONT WILL PLOW THROUGH NORTHEAST NM FRIDAY NIGHT. MODELS CONTINUE IDEA OF A MODERATE WESTERLY WIND FLOW NEAR MOUNTAIN TOP LEVEL AGAIN FRIDAY....MAINLY OVER THE NORTHWEST THIRD. NOT MUCH CHANGE IS EXPECTED IN RELATIVE HUMIDITY VALUES OR VENTILATION...EXCEPT OVER THE FAR NORTHEAST WHERE THE FRONT WILL START TO BRING OM HIGHER RELATIVE HUMIDITY VALUES AND POOR VENTILATION IN THERE BY LATE AFTERNOON. THIS VIGOROUS FRONT IS EXPECTED TO BRING WIDESPREAD LOW CLOUDS...COLDER CONDITIONS...AND SOME DRIZZLE OR LIGHT RAIN TO THE EASTERN PLAINS AND EASTERN SLOPES OF THE CENTRAL MOUNTAINS SATURDAY MORNING AND AGAIN SATURDAY NIGHT/SUNDAY MORNING. HIGH TEMPERATURES WILL BE 20 TO 30 DEGREES BELOW AVERAGE EAST AND 5 TO 10 DEGREES BELOW AVERAGE FOR EARLY OCTOBER CENTRAL AND WEST. POOR VENTILATION RATES EAST AND FAIR WEST ARE ANTICIPATED FOR SATURDAY. TEMPERATURES SLOWLY MODIFY AND THE LOW CLOUDS EAST GRADUALLY DISSIPATE DURING THE DAY SUNDAY AS SURFACE HIGH PRESSURE OVER THE SOUTHERN PLAINS BEGINS TO SHIFT EAST AND SURFACE WINDS BECOME SOUTHERLY TO SOUTHEASTERLY. MEDIUM RANGE WEATHER PREDICTION MODELS CONTINUE WITH IDEA OF A CLOSED UPPER LOW DRIFTING SOUTH THROUGH CALIFORNIA EARLY NEXT WEEK...EVENTUALLY SETTLING THE UPPER LOW OVER THE LOWER COLORADO RIVER AROUND MIDWEEK. THE DEVIL IS ALWAYS IN THE DETAILS...HOWEVER...THE MODELS ARE AND HAVE BEEN REMARKABLY CONSISTENT FROM RUN TO RUN...TRENDING TOWARD AT LEAST AN UNSETTLED PATTER FOR THE LATTER HALF OF NEXT WEEK. 33 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
531 PM CDT THU OCT 4 2012 .UPDATE... THE COLD FRONT HAS NOW SURGED TO A LINE FROM JUST WEST OF BOWIE... TO NEAR JACKSBORO...TO POSSUM KINGDOM LAKE...TO CISCO AS OF 5 PM. THE AIRMASS IS SHALLOW WITH A DEPTH BETWEEN 1-2 KFT...THUS THE MODELS ARE STRUGGLING WITH THE FRONTAL POSITION. THE RUC IS THE ONLY MODEL EVEN CLOSE TO REALITY. THERE IS ALSO PLENTY OF STRATO- CU BOTH AHEAD AND BEHIND THE FRONT DUE TO ISENTROPIC ASCENT UP THROUGH 850 MB. WE HAVE SPED UP THE FRONT AND BRING IT SOUTH-SOUTHEAST WITH THE BEST PUSH OCCURRING ACROSS THE FAR WESTERN COUNTIES WHERE BEST PRESSURE RISES WILL OCCUR ACROSS THE HIGHER TERRAIN. THE COLD FRONT IS PROJECTED TO BE NEAR A SHERMAN...TO FORT WORTH...TO HAMILTON BY MIDNIGHT. GUSTY NORTH WINDS OF 10 TO 20 MPH ARE EXPECTED BEHIND THE FRONT...BUT SHOULD SETTLE DOWN OVERNIGHT. WE HAVE LOWERED LOW TEMPERATURES OVERNIGHT INTO THE MID-UPPER 50S ACROSS THE NORTHWEST COUNTIES BEHIND THE FRONT DUE TO THE SHALLOW COLD ADVECTION AND EXPECTED CLOUD COVER...WHILE 60S TO LOWER 70S ARE ELSEWHERE. CONFIDENCE ON EXACTLY WHERE THE FRONT MAY STALL THROUGH FRIDAY MORNING REMAINS UNCERTAIN...BUT THIS IS OUR BEST GUESS AT THIS POINT. WE HAVE LEFT LOW RAIN CHANCES NORTH OF I-20. FEEL MOST THE ACTIVITY WILL BE IN THE FORM OF LIGHT SHOWERS...THOUGH STEEP MID LEVEL LAPSE RATES ABOVE THE FRONTAL INVERSION MAY RESULT IN A FEW ELEVATED THUNDERSTORMS ACROSS THE RED RIVER VALLEY CLOSER TO A SHORTWAVE RIPPLING ACROSS OK/KS. 05/ && .PREV DISCUSSION... /ISSUED 225 PM CDT THU OCT 4 2012/ WATER VAPOR IMAGERY SHOWS A NICE LOOKING LOW PRESSURE SYSTEM SPIRALING EAST FROM THE NORTHERN PLAINS INTO THE GREAT LAKES REGION. A RESULTING COLD FRONT CONTINUES ITS PUNCH SOUTH THROUGH THE SOUTHERN PLAINS AND WAS LOCATED JUST TO THE NORTHWEST OF THE FORECAST AREA THIS AFTERNOON. PRESSURE RISES BEHIND THE FRONT AND CURRENT MOMENTUM WOULD CARRY THE LEADING EDGE OF THIS BOUNDARY TO NEAR THE DALLAS-FORT WORTH METROPLEX JUST AFTER SUNSET THIS EVENING. THE FRONT SHOULD THEN BECOME STATIONARY AS THE INITIAL NORTHERN BRANCH SHORTWAVE SWINGS EASTWARD INTO THE NORTHEASTERN CONUS...BRINGING LIGHT AND VARIABLE WINDS IN THE VICINITY OF THE FRONT NEAR THE METROPLEX TONIGHT. FOR TOMORROW...A LONG WAVE TROUGH CENTERED OVER THE CENTRAL U.S. WILL BEGIN DEEPENING AS THE NEXT SHORTWAVE DIVES SOUTHWARD OUT OF CANADA INTO THE NORTHERN AND CENTRAL PLAINS. THE RESULT WILL BE A FORCEFUL SECONDARY PUSH BEHIND THE FRONT...DRIVING THE BOUNDARY SOUTH THROUGH NORTH AND CENTRAL TEXAS FRIDAY NIGHT THROUGH SATURDAY. THIS WILL BRING GUSTY NORTH WINDS TO THE ENTIRE AREA AS THE BOUNDARY CLEARS THE SOUTHERN COUNTIES SATURDAY AFTERNOON. RAIN CHANCES WILL INITIALLY OCCUR TONIGHT OVER THE NORTHERN AND NORTHWEST COUNTIES AS THE FRONT MOVES INTO THE AREA. SB CAPE IS NOT IMPRESSIVE... BUT POCKETS OF MEAGER ELEVATED INSTABILITY COULD LEAD TO A FEW ISOLATED STORMS LATE TONIGHT AND TOMORROW NEAR OR JUST NORTH OF THE BOUNDARY. BY SATURDAY...THE PRIMARY MECHANISM FOR RAIN PRODUCTION SHOULD BE ISENTROPIC UPGLIDE ABOVE THE RELATIVELY SHALLOW FRONTAL LAYER...WHICH SHOULD BE MAINLY IN THE FORM OF LIGHT RAIN OR DRIZZLE. CLOUDY SKIES WILL ALSO BE THE RULE ON SATURDAY...WHICH IN COMBINATION WITH PERSISTENT COLD AIR ADVECTION WILL NOT ALLOW TEMPS TO CLIMB MUCH ABOVE 60 IF AT ALL. CONDITIONS SHOULD DRY OUT BY SUNDAY...GIVING WAY TO COOLER...DRIER CONDITIONS FOR THE FIRST HALF OF NEXT WEEK. NEAR-NORMAL TEMPERATURES WILL THEN RETURN AROUND THE MIDDLE PART OF NEXT WEEK AS HIGH PRESSURE REDEVELOPS OVER THE CENTRAL U.S. 30 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 71 84 53 58 47 / 10 10 30 30 20 WACO, TX 67 88 59 65 49 / 5 5 20 20 20 PARIS, TX 67 81 51 57 44 / 20 20 40 40 20 DENTON, TX 63 80 51 57 46 / 20 20 30 30 20 MCKINNEY, TX 69 82 50 57 46 / 20 20 30 30 20 DALLAS, TX 70 84 56 58 46 / 10 10 30 30 20 TERRELL, TX 69 84 53 60 46 / 10 10 30 30 20 CORSICANA, TX 67 87 57 64 48 / 10 10 20 30 20 TEMPLE, TX 67 88 60 68 49 / 5 5 10 20 20 MINERAL WELLS, TX 60 80 47 56 45 / 10 10 20 30 20 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 79/05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1238 PM CDT THU OCT 4 2012 .AVIATION... SKIES ARE CLEARING VERY QUICKLY AND WILL BE VFR AT ALL TERMINALS WITHIN THE NEXT 30 MINUTES. THE AFTERNOON AND EVENING WILL BE VFR. WINDS WILL BE 10 TO 15 KTS DURING THE AFTERNOON. DEEP SOUTHEASTERLY FLOW WILL BRING MVFR/IFR CIGS BACK INTO THE AUS AND SAN ANTONIO AREAS OVERNIGHT. GRADUAL LIFTING OF CIGS LATE FRI MORNING WILL BRING VFR BACK. && .PREV DISCUSSION... /ISSUED 1045 AM CDT THU OCT 4 2012/ UPDATE... WE HAVE UPDATED THE FORECAST TO INCREASE CLOUD COVER ALONG THE RIO GRANDE PLAINS AND EDWARDS PLATEAU THROUGH THE REMAINDER OF THIS MORNING. DISCUSSION... STRATUS CLOUDS CONTINUE TO HANG TOUGH ACROSS THE RIO GRANDE PLAINS AND EDWARDS PLATEAU THIS MORNING. THE LATEST RUC SUGGESTS CLOUDS WILL REMAIN INTACT THROUGH ROUGHLY NOON AND WE HAVE INCREASED CLOUD COVER OUT WEST. OTHERWISE...ONLY MINOR CHANGES HAVE BEEN MADE TO THE DEW POINTS AND WINDS BASED ON THE LATEST OBSERVATIONAL TRENDS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 69 91 66 73 51 / - - - 10 20 AUSTIN BERGSTROM INTL AIRPORT 65 89 62 75 50 / - - - 10 20 NEW BRAUNFELS MUNI AIRPORT 67 90 64 78 50 / - - - - 20 BURNET MUNI AIRPORT 68 88 61 67 48 / - - 10 10 20 DEL RIO INTL AIRPORT 69 94 68 85 55 / - 0 0 - 20 GEORGETOWN MUNI AIRPORT 66 89 64 68 49 / - - 10 10 20 HONDO MUNI AIRPORT 67 91 62 82 51 / - - - - 20 SAN MARCOS MUNI AIRPORT 66 90 63 76 50 / - - - - 20 LA GRANGE - FAYETTE REGIONAL 65 90 65 80 54 / - - - 10 20 SAN ANTONIO INTL AIRPORT 69 89 65 79 52 / - - - - 20 STINSON MUNI AIRPORT 69 90 66 81 53 / - - - - 20 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...24 PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
257 PM CDT THU OCT 4 2012 .SHORT TERM...TONIGHT THROUGH SUNDAY 257 PM CDT THU OCT 4 2012 MAIN FORECAST CONCERNS ON BREEZY NORTHWEST WINDS THIS EVENING AND AGAIN ON FRIDAY. FOCUS THEN TURNS TO LOW PRECIPITATION CHANCES ON SATURDAY AND TEMPERATURES THROUGH THE WEEKEND. LATEST WATER VAPOR IMAGERY SHOWED A POTENT LOW PRESSURE SYSTEM OVER NORTHERN MINNESOTA RESPONSIBLE FOR PRODUCING HEAVY...WET SNOW OVER PORTIONS OF NORTHWEST MINNESOTA. SURFACE OBSERVATIONS INDICATED A TIGHT PRESSURE GRADIENT OVER THE FORECAST AREA IN THE WAKE OF A COLD FRONT THAT MOVED THROUGH THIS MORNING. THE TIGHT GRADIENT AND COLD AIR ADVECTION BEHIND THE FRONT WAS KEEPING BREEZY WEST/NORTHWEST ACROSS THE FORECAST AREA. THE LOW IS EXPECTED TO LIFT NORTHEAST TONIGHT INTO SOUTHWEST ONTARIO AND MEANDER EAST...JUST NORTH OF LAKE SUPERIOR. A TIGHT PRESSURE GRADIENT WILL REMAIN IN PLACE OVER THE AREA AS THE REGION IS IN BETWEEN THE LOW PASSING TO THE NORTH AND HIGH PRESSURE ATTEMPTING TO BUILD INTO THE DAKOTAS. THIS WILL KEEP BREEZY CONDITIONS THROUGH THIS EVENING. WINDS WILL TAPER OFF LATE IN THE EVENING FOR LOCATIONS ALONG AND SOUTH OF INTERSTATE 90. NAM AND RUC LOW LEVEL RELATIVE HUMIDITY FIELDS SHOWS A SCATTERED TO BROKEN STRATUS DECK MOVING IN FROM THE NORTHWEST THIS EVENING AND MAKING IT TO ABOUT THE INTERSTATE 90 CORRIDOR. HAVE INCREASED CLOUD COVER THIS EVENING INTO THE OVERNIGHT HOURS ACROSS THESES AREAS. LOOK FOR LOW TEMPERATURES TO FALL INTO THE 30S TONIGHT. AN UPPER TROUGH WILL DIVE SOUTH INTO THE DAKOTAS AND NORTHERN MINNESOTA ON FRIDAY OUT OF SOUTHERN MANITOBA...SASKATCHEWAN AND ALBERTA AS THE LOW FILLS AND LIFTS NORTHEAST OVER JAMES BAY. PLAN ON CONTINUED BREEZY NORTHWEST WINDS ACROSS THE AREA ON FRIDAY AS THE PRESSURE GRADIENT REMAINS TIGHT. WIND SPEEDS ARE EXPECTED TO RANGE FROM 14 TO 24 MPH. SOME GUSTS IN THE 25 TO 30 MPH RANGE ARE POSSIBLE IN OPEN AREAS. THE GRADIENT WILL REMAIN TIGHTER THOUGH THE DAY ACROSS CENTRAL INTO NORTH CENTRAL WISCONSIN SO HAVE INCREASED WINDS GUSTS SLIGHTLY ACROSS THESE AREAS. HIGH TEMPERATURES WILL RANGE FROM THE LOWER 40S ACROSS NORTHERN WISCONSIN TO THE LOWER 50S OVER NORTHEAST IOWA. THE TROUGH IS EXPECTED TO PUSH SOUTH INTO CENTRAL MINNESOTA AND NORTHERN WISCONSIN LATE FRIDAY NIGHT INTO SATURDAY MORNING. CLOUDS WILL BE ON THE INCREASE FROM NORTH TO SOUTH AS THE TROUGH MOVES IN. CANNOT RULE OUT A LIGHT SPRINKLE OR SNOW SHOWER FRIDAY NIGHT INTO SATURDAY MORNING ALONG AND NORTH OF THE INTERSTATE 94 CORRIDOR. FORECAST SOUNDING ARE NOT SHOWING ENOUGH SATURATION FOR ICE ALOFT SO THE PRECIPITATION COULD FALL AS SPRINKLES OR POSSIBLY FREEZING SPRINKLES DEPENDING ON SURFACE TEMPERATURES. THERE APPEARS TO BE ENOUGH SATURATION FOR PRECIPITATION BUT THERE REALLY IS NOT APPRECIABLE LIFT SO CONCERNED THAT THE MAIN IMPACT FROM THE TROUGH WILL BE JUST INCREASING STRATUS AND NO PRECIPITATION. WILL MAINTAIN SLIGHT CHANCES FOR RAIN/SNOW SHOWERS OVER NORTH CENTRAL WISCONSIN. PLAN ON LOW TEMPERATURES RANGING FROM THE UPPER 20S TO LOWER 30S OVER NORTH CENTRAL WISCONSIN TO THE LOWER 30S OVER NORTHEAST IOWA. GUIDANCE HAS BEEN TRENDING COOLER FRIDAY NIGHT BUT CONCERNED THAT THE INCREASING CLOUD COVER AND PERSISTENT NORTHWEST WINDS WILL LEAD TO SLIGHTLY WARMER TEMPERATURES. WILL HAVE TO KEEP A CLOSE WATCH ON THE PROGRESSION OF THE STRATUS DECK FRIDAY NIGHT AND WINDS. LOCATIONS THAT REMAIN CLEAR AND DECOUPLE COULD SEE TEMPERATURES PLUMMET INTO THE MID 20S. SATURDAY WILL BE A RATHER CHILLY FALL DAY ACROSS THE REGION. THE TROUGH WILL CONTINUE ITS SOUTHWARD PUSH...LEADING TO AN EXPANSIVE STRATUS DECK ACROSS MUCH OF THE FORECAST AREA. DECIDED TO MAINTAIN A SLIGHT CHANCE FOR RAIN/SNOW SHOWERS OVER NORTH CENTRAL WISCONSIN AS THE TROUGH MOVES THROUGH DURING THE MORNING HOURS. HAVE INCLUDED A CHANCE OF FLURRIES ACROSS WEST CENTRAL WISCONSIN INTO SOUTHEAST MINNESOTA AND NORTHEAST IOWA EARLY SATURDAY MORNING...THEN SWITCHED OVER TO SPRINKLES LATE IN THE MORNING AS TEMPERATURES WARM. SEEING THE SATURATION FOR SOME PRECIPITATION IN THE FORECAST SOUNDINGS BUT VERY MINIMAL LIFT. THINKING THE TROUGH SHOULD BE ABLE TO PRODUCE SOME VERY LIGHT PRECIP AS IT MOVES THROUGH. OTHERWISE...PLAN ON A MOSTLY CLOUDY AND COOL DAY WITH HIGHS RANGING FROM THE LOWER 40S OVER NORTHERN WISCONSIN TO THE UPPER 40S ACROSS NORTHEAST IOWA. SATURDAY INTO SATURDAY NIGHT...850 MB TEMPERATURE STANDARDIZED ANOMALIES WILL FALL TO AROUND -1.5 C BASED ON THE ECMWF....WHILE THE NAM IS SUGGESTING -2.0 C. ANOMALIES THIS LOW SUGGEST THE POTENTIAL FOR NEAR RECORD LOW TEMPERATURES ACROSS THE REGION. THE COLD AIRMASS OVER THE REGION AND CLEARING SKIES LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING WILL LEAD TO NEAR RECORD LOW TEMPERATURES AND A HARD...GROWING SEASON ENDING FREEZE...WITH LOWS FALLING INTO THE 20S. A FREEZE WARNING WILL BE NEEDED LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING. SURFACE HIGH PRESSURE WILL EDGE INTO THE REGION ON SUNDAY WITH MOSTLY SUNNY SKIES EXPECTED. AFTER A COLD START TO THE DAY...LOOK FOR HIGH TEMPERATURES TO REBOUND INTO THE UPPER 40S OVER NORTHERN WISCONSIN TO THE LOWER 50S ACROSS NORTHEAST IOWA. .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY 257 PM CDT THU OCT 4 2012 04.12 MEDIUM RANGE MODELS IN REASONABLE AGREEMENT THROUGH THE EXTENDED PERIOD. NORTHWEST FLOW ALOFT WILL CONTINUE INTO SUNDAY NIGHT WITH SURFACE HIGH PRESSURE IN CONTROL. THE HIGH IS EXPECTED TO SLIDE EAST OF THE AREA MONDAY AS A COLD FRONT DRIFTS SOUTH ACROSS NORTHERN MINNESOTA INTO SOUTHERN NORTH DAKOTA. MEANWHILE...AN UPPER TROUGH WILL MOVE THROUGH MONTANA AND INTO WESTERN NORTH DAKOTA. SOUTHWEST FLOW AHEAD OF THE APPROACHING FRONT WILL HELP TEMPERATURES CLIMB INTO THE UPPER 50S TO LOWER 60S ACROSS THE FORECAST AREA MONDAY AFTERNOON. THE FRONT IS EXPECTED TO PUSH SOUTH INTO NORTHERN WISCONSIN LATE MONDAY NIGHT BRINGING A SLIGHT CHANCE OF RAIN SHOWERS TO NORTH CENTRAL WISCONSIN. THE FRONT WILL CONTINUE TO MOVE SOUTH DURING THE DAY ON TUESDAY BRINGING A SLIGHT CHANCE OF RAIN SHOWERS TO MUCH OF THE FORECAST AREA. HIGH PRESSURE IS EXPECTED TO BUILD BACK INTO THE UPPER MISSISSIPPI RIVER VALLEY WEDNESDAY INTO THURSDAY PROVIDING DRY AND QUIET WEATHER. LOOK FOR HIGH TEMPERATURES IN THE 50S ON WEDNESDAY...CLIMBING INTO THE MID 50S TO LOWER 60S THURSDAY AFTERNOON. && .AVIATION...THROUGH 18Z FRIDAY 1146 AM CDT THU OCT 4 2012 CONCERNS ARE ON WINDS AND POTENTIAL FOR MVFR STRATUS. THE COMBINATION OF A TIGHT PRESSURE GRADIENT AND COLDER AIR SURGING EAST BEHIND A COLD FRONT THAT PASSED THROUGH THE TAF SITES HAS LED TO WEST WINDS GUSTING TO 20-25 KT. THIS SHOULD CONTINUE THROUGH THE AFTERNOON...PERHAPS GETTING 5 KT STRONGER AS WE APPROACH THE MAXIMUM OF DAYTIME MIXING. LOOK FOR THE GUSTS AND SPEEDS TO DIMINISH THIS EVENING TO 15-20 KT BY 01-02Z. IN FACT...GUSTS LOOK TO END ENTIRELY AT KLSE WITH THE VALLEY AIDING IN THE DECREASE. WITH THE PRESSURE GRADIENT STAYING TIGHT AHEAD OF A COLD FRONT DROPPING SOUTH THROUGH MINNESOTA ON FRIDAY...EXPECT WINDS TO JUMP BACK UP TO 15-20 KT WITH GUSTS OF 20-25 KT BY 15Z. ALSO IN THE WAKE OF THE COLD FRONT IS A MASS OF MVFR STRATUS ACROSS THE DAKOTAS INTO WESTERN MINNESOTA. SOME OF THIS WILL LIKELY DISSIPATE DURING THE AFTERNOON. HOWEVER...WINDS AROUND 3000 FT BECOME NORTHWEST THIS EVENING. THESE WINDS COMBINED WITH NIGHTTIME COOLING COULD ALLOW THE STRATUS TO FILTER INTO THE TAF SITES. THE STRATUS IF IT DOES MOVE IN WOULD LIKELY PERSIST INTO FRIDAY MORNING. SINCE THERE IS UNCERTAINTY ON THE STRATUS...HAVE FOR NOW INCLUDED A SCT 3000 AT KRST AND 3500 AT KLSE...THINKING THE VALLEY SHOULD PRODUCE A SLIGHTLY HIGHER CEILING. MONITORING OF THE STRATUS WILL BE REQUIRED THIS EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... 257 PM CDT THU OCT 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 AM CDT THU OCT 4 2012 .SHORT TERM...TODAY THROUGH SATURDAY 300 AM CDT THU OCT 4 2012 MAIN FORECAST CHALLENGE WILL BE A STRONG COLD FRONTAL PASSAGE TODAY ALONG WITH SHOWER/ISOLATED THUNDER CHANCES...THEN GUSTY POST FRONTAL WINDS. CONCERNS BEYOND THIS INCLUDE WELL BELOW NORMAL TEMPERATURES INTO THE WEEKEND WITH A HARD FREEZE EXPECTED SATURDAY NIGHT/SUNDAY MORNING. LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS A POTENT/DEEPENING TROUGH MOVING EAST ACROSS THE DAKOTAS WITH A 90-95KT 300MB JET ENTERING THE BASE OF THE TROUGH OVER SD. AT THE SURFACE...DEEP OCCLUDING LOW WAS LOCATED OVER WEST CENTRAL MN WITH A COLD FRONT EXTENDING SOUTHWARD INTO WESTERN IA. RADAR MOSAIC/SURFACE OBSERVATIONS SHOWING ELEVATED SHOWER/ISOLATED THUNDER ACTIVITY ACROSS EASTERN NEB WITH EXPANSIVE DEFORMATION RAIN/SNOW ACROSS THE EASTERN DAKOTAS/NORTHWEST MN. OTHERWISE...ACROSS THE LOCAL FORECAST AREA...IR IMAGERY SHOWING A FEW MID/HIGH CLOUDS. 04.00Z MODELS SHOWING GOOD AGREEMENT THROUGH THE SHORT TERM. FOR TODAY...AS THE LOW CONTINUES TO DEEPEN AND MOVE NORTH TO ALONG THE MN/CANADIAN BORDER THIS MORNING...EXPECTING THE COLD FRONTAL PASSAGE ALONG THE MISSISSIPPI RIVER BY 15Z AND THEN EXITING EAST OF THE AREA AROUND NOON. NAM AND HRRR WRF SHOWING SCATTERED PRECIPITATION ALONG A POST FRONTAL TROUGH MOVING INTO THE AREA THIS MORNING...MAINLY ACROSS NORTHEAST IOWA INTO SOUTHERN WI. NAM DEPICTING 200-400J/KG 1-7KM MUCAPE...SO KEPT MENTION OF ISOLATED THUNDER IN AS WELL. APPEARS RAIN CHANCES MAINLY CONFINED TO THIS MORNING THEN PUSHING EAST AFTER NOON. OTHERWISE...BIGGER STORY WILL BE GUSTY WEST WINDS OVERTAKING THE AREA BEHIND THE COLD FRONT AS DRY SLOT/COLD AIR ADVECTION NOSES IN. SUSTAINED WINDS EXPECTED TO BE IN THE 15-20 MPH RANGE WITH GUSTS HITTING AROUND 30-35 MPH. LOOK FOR HIGHS IN THE 50S TO MIDDLE 60S...SOME 15-20 DEGREES COOLER THAN HIGHS ON WEDNESDAY. FOR TONIGHT...THE DRY SLOT WILL KEEP SKIES MOSTLY CLEAR OVERNIGHT AS THE LOW BEGINS TO FILL AS IT MOVES NORTHEAST INTO ONTARIO CANADA. A FAIRLY TIGHT PRESSURE GRADIENT IS EXPECTED TO KEEP WINDS UP OVERNIGHT IN THE 15 TO 25 MPH RANGE. COLD AIR ADVECTION WILL CONTINUE AS 925MB TEMPERATURES FALL INTO NEGATIVE TERRITORY //ZERO TO MINUS 2C. THIS SHOULD PRODUCE OVERNIGHT RIGHT AROUND THE FREEZING MARK WITH WINDS CHILL IN THE 20-25 DEGREE RANGE THROUGH THE EARLY MORNING HOURS OF FRIDAY. FOR THE REST OF FRIDAY...ANOTHER BLUSTERY COLD DAY WILL BE ON TAP. DESPITE PARTLY TO MOSTLY SUNNY SKIES HIGHS WILL ONLY MAKE IT INTO THE MIDDLE 40S TO LOWER 50S ALONG WITH WEST/NORTHWEST WINDS OF 15-30 MPH. FOR FRIDAY NIGHT INTO SATURDAY...A SECONDARY MID-LEVEL TROUGH WILL DROP SOUTHEAST ACROSS THE AREA FOR A CHANCE OF MIXED RAIN AND SNOW SHOWERS. APPEARS MOST OF THIS ACTIVITY WILL REMAIN NORTHEAST OF I-94 IN BETTER PV-ADVECTION/COLDER AIR ALOFT. TEMPERATURES EXPECTED TO DIP TO AROUND THE 30 DEGREE MARK FRIDAY NIGHT AND ONLY MAKING IT INTO THE 40S ON SATURDAY...WHICH IS MORE TYPICAL FOR MID-NOVEMBER. SATURDAY NIGHT EXPECTED TO SEE A HARD FREEZE AS LOWS TUMBLE INTO THE LOWER AND MIDDLE 20S UNDER MOSTLY CLEAR SKIES AS A SURFACE RIDGE AXIS MOVES OVERHEAD. COULD SEE SOME RECORD LOWS BEING TIED OR BROKEN. FOR EXAMPLE...CURRENT FORECAST LOW FOR LA CROSSE IS 26 AND THIS WOULD TIE THE RECORD SET IN 2001. THIS WILL ALSO LIKELY MARK A FINAL END TO THE GROWING SEASON FOR AREAS THAT HAVE NOT YET SEEN A HARD FREEZE...THIS BEING AREAS ALONG THE MISSISSIPPI/WISCONSIN RIVER VALLEYS. FREEZE HEADLINES MAY EVENTUALLY BE NEEDED TO HIGHLIGHT THIS. .LONG TERM...SUNDAY THROUGH WEDNESDAY 300 AM CDT THU OCT 4 2012 04.00Z GFS/ECMWF IN OVERALL GOOD AGREEMENT WITH SYNOPTIC PATTERN THROUGH THE EXTENDED PERIOD. SUNDAY WILL SEE SOME SLIGHT MODERATION IN TEMPERATURES AS THE RIDGE AXIS SLIPS SOUTH...SETTING UP SOUTHWEST WINDS BACK INTO THE REGION. UNDER MOSTLY SUNNY SKIES...LOOK FOR HIGHS IN THE 40S TO LOWER 50S. MODELS CONSISTENT WITH BRING A LOW FROM ALBERTA CANADA INTO ONTARIO ON MONDAY. INCREASING SOUTHWEST FLOW IN THE WARM SECTOR OF THE LOW EXPECTED TO YIELD HIGHS IN THE MIDDLE 50S TO LOWER 60S. COLD FRONT FROM THIS LOW WILL THEN SWING SOUTHEAST ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY BRINGING WITH IT A CHANCE OF RAIN SHOWERS. WEDNESDAY LOOKS DRY WITH HIGHS IN THE 50S AS HIGH PRESSURE BUILDS OVERHEAD. && .AVIATION...THROUGH 18Z FRIDAY 1146 AM CDT THU OCT 4 2012 CONCERNS ARE ON WINDS AND POTENTIAL FOR MVFR STRATUS. THE COMBINATION OF A TIGHT PRESSURE GRADIENT AND COLDER AIR SURGING EAST BEHIND A COLD FRONT THAT PASSED THROUGH THE TAF SITES HAS LED TO WEST WINDS GUSTING TO 20-25 KT. THIS SHOULD CONTINUE THROUGH THE AFTERNOON...PERHAPS GETTING 5 KT STRONGER AS WE APPROACH THE MAXIMUM OF DAYTIME MIXING. LOOK FOR THE GUSTS AND SPEEDS TO DIMINISH THIS EVENING TO 15-20 KT BY 01-02Z. IN FACT...GUSTS LOOK TO END ENTIRELY AT KLSE WITH THE VALLEY AIDING IN THE DECREASE. WITH THE PRESSURE GRADIENT STAYING TIGHT AHEAD OF A COLD FRONT DROPPING SOUTH THROUGH MINNESOTA ON FRIDAY...EXPECT WINDS TO JUMP BACK UP TO 15-20 KT WITH GUSTS OF 20-25 KT BY 15Z. ALSO IN THE WAKE OF THE COLD FRONT IS A MASS OF MVFR STRATUS ACROSS THE DAKOTAS INTO WESTERN MINNESOTA. SOME OF THIS WILL LIKELY DISSIPATE DURING THE AFTERNOON. HOWEVER...WINDS AROUND 3000 FT BECOME NORTHWEST THIS EVENING. THESE WINDS COMBINED WITH NIGHTTIME COOLING COULD ALLOW THE STRATUS TO FILTER INTO THE TAF SITES. THE STRATUS IF IT DOES MOVE IN WOULD LIKELY PERSIST INTO FRIDAY MORNING. SINCE THERE IS UNCERTAINTY ON THE STRATUS...HAVE FOR NOW INCLUDED A SCT 3000 AT KRST AND 3500 AT KLSE...THINKING THE VALLEY SHOULD PRODUCE A SLIGHTLY HIGHER CEILING. MONITORING OF THE STRATUS WILL BE REQUIRED THIS EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... 300 AM CDT THU OCT 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...AJ