AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 259 PM MDT WED OCT 18 2006 .SHORT TERM... (TONIGHT AND THURSDAY) MAIN SHORT TERM CONCERNS INCLUDE CLOUD COVER AND TEMPERATURES. CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSIS INDICATING WEAK WEST TO NORTHWEST FLOW ALOFT ACROSS THE STATE AS BROAD UPPER TROUGH CONTINUES TO SLOWLY LIFT OUT ACROSS THE REGION WITH ASSOCIATED COLD POOL (-22C AT H5) MOVING ACROSS THE SOUTHERN REACHES OF THE STATE ATTM. AT THE SFC...COOL 1023MB HIGH PRESSURE SYSTEM CONTINUES TO BUILD ACROSS EASTERN COLORADO WITH WEAK LOW LEVEL UPSLOPE KEEPING MVFR AND PATCHY IFR STRATUS IN PLACE ACROSS THE LOWER EASTERN SLOPES AND FOOTHILLS ATTM. FOR TONIGHT...UPPER TROUGH CONTINUES TO MOVE EAST WITH INCREASING NORTHWEST FLOW ALOFT ACROSS THE REGION AHEAD OF MINOR EMBEDDED SHORT WAVE MOVING ACROSS THE NORTHERN TIER OF STATES ATTM. WITH TROUGH AXIS AND COLD POOL STILL MOVING ACROSS THE REGION...HAVE KEPT ISOLATED TO SCATTERED POPS ACROSS MAINLY THE HIGH TERRAIN THIS EVENING WITH BEST POPS ACROSS THE SOUTHERN MTS AND THE RATON MESA REGION. WITH CONVECTIVE NATURE COULD SEE A QUICK INCH OF SNOW UNDER THE STRONGEST CELLS. ANY CONVECTIVE ACTIVITY SHOULD END QUICKLY WITH THE SUN...SAVE ISOLATED SHOWERS ACROSS THE CENTRAL MTS WITH INCREASING OROGRAPHIC FLOWS. AS FOR CLOUDS AND TEMPERATURES...SFC HIGH PRESSURE ACROSS THE PLAINS TO CONTINUE TO BUILD SOUTH AND EAST INTO THE SOUTHERN HIGH PLAINS. MOVEMENT OF SYSTEM WILL WEAKENING LOW LEVEL UPSLOPE WITH SOUTH TO SOUTHWEST RETURN FLOW DEVELOPING ACROSS THE PLAINS OVERNIGHT. WITH THAT IN MIND...HAVE KEPT THE EASTERN MTS AND I-25 CORRIDOR MOSTLY CLOUDY THROUGH THE EVENING...WITH DECREASING CLOUDS AFTER MIDNIGHT WITH DRIER AND SUBSIDENT AIR IN THE NORTHWESTERLY FLOW ALOFT AND DECREASING UPSLOPE HELP TO BREAK UP THE CLOUDS. FOR AVIATION...WILL LIKELY CONTINUE TO SEE IFR STRATUS PERSIST FOR COS THROUGH MIDNIGHT...WITH IMPROVING CONDITIONS BY DAYBREAK. WITH THE DECREASING CLOUDS AND COLD AIRMASS IN PLACE...WILL LIKELY SEE A HARD FREEZE ACROSS THE REST OF THE EASTERN PLAINS WHICH DID RECEIVE IT LAST NIGHT. WILL NOT ISSUE ANY FREEZE HIGHLIGHT FOR THE REST OF THE YEAR AS WE ARE PAST THE NORMAL GROWING SEASON WHICH IS OCTOBER 15TH FOR THE EASTERN PLAINS. THURSDAY...MODERATE NW FLOW REMAINS IN PLACE ACROSS THE REGION AS MINOR EMBEDDED SHORTWAVE IN THE FLOW MOVES ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN HIGH PLAINS. WAVE TO BY TO FAR NORTH AND EAST TO BRING MORE THAN HIGH CLOUDS TO THE AREA THROUGH THE AFTERNOON...SAVE THE CENTRAL MTS WHERE THERE WILL ENOUGH MOISTURE IN PLACE FOR ISOLATED SHOWERS. H7 TEMPS WARM TO BETWEEN 0C AND -4C ACROSS THE AREA...AND HAVE STAYED CLOSE TO GUIDANCE FOR HIGHS...SAVE SNOW COVERED AREAS ACROSS THE RAMPART RANGE AND PALMER DVD. -MW .LONG TERM... (THURSDAY NIGHT THROUGH WEDNESDAY) ...FCST CONCERNS THIS PD IS WX SYSTEM FOR FRI NITE/SAT... MAIN CONCERN THIS FCST PD IS EXTENT OF COLD WX AND PRECIP WITH INCOMING WX SYSTEM FOR THIS FRI NITE INTO SAT. MODEL TRENDS TODAY HAVE BEEN A BIT STRONGER AND FARTHER WEST W/500 MB FEATURES AS COMPARED TO THIS TIME YDAY. BOTH GFS AND NAM ARE NOW SHOWING SOME 700MB UPSLOPE ON SAT ON E FACING SLOPES OF S MTNS. GIVEN CURRENT TRENDS...HAVE INCREASED POPS A BIT FOR SAT ON E FACING SLOPES/I-25 CORRIDOR REGION. AS FOR THE REST OF THE FCST...MADE LITTLE CHANGES TO INHERITED GRIDDS. IT STILL APPEARS FRIDAY WILL BE A NICE DAY ALBEIT A BIT BREEZY ACROSS MOST OF THE CWA. IN THE MTNS...ESPECIALLY C MTNS AND PIKES PEAK REGION...IT WILL GET WINDY WITH GUSTS IN THE 40 MPH RANGE. FRONT WILL COME DOWN EARLY FRIDAY EVENING...WITH A LIKELY 2NDRY SURGE COMING DOWN ON SAT. NAM NOT PRINTING OUT ANY SIGNIF PRECIP BUT BELIEVE THIS MAY BE UNDERDONE GIVEN FRONTOGENESIS AND USPLOPE...ESPECIALLY ON E SLOPES OF S MTNS. BY SUNDAY...SHOULD BE A RATHER NICE AUTUMN DAY WITH HIGHS IN THE 50S MOST AREAS ON THE PLAINS. FLAT NW-FLOW RIDGE PATTER FOR NEXT WEEK WITH SEASONABLE TEMPS. ANY PRECIP SHOULD BE ON W FACING SLOPES OF C MTNS. \/HODANISH && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/34 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 542 AM MDT WED OCT 18 2006 ...UPDATED TO REMOVE EXPIRED WINTER WEATHER HEADLINES... SNOW SHOWERS IN THE MOUNTAINS WILL CONTINUE DECREASING THROUGH THIS AFTERNOON WITH ONLY LIGHT ADDITIONAL ACCUMULATIONS EXPECTED. .SHORT-TERM (TODAY THROUGH THURSDAY NIGHT)... IR SATELLITE SHOWS OROGRAPHIC CLOUDS AND PROBABLY SNOW CONTINUING OVER ERN UT AND WRN C0 MTS. WILL LEAVE THE WINTER WARNINGS AND ADVISORIES GOING TO THE EXPIRATION TIME AT ABOUT SUNRISE TODAY. SNOWFALL AND CLOUD COVER WILL SLOWLY DISSIPATE THROUGH THE REST OF TODAY AND TONIGHT. SFC DATA SHOWS WINDS GRADUALLY SHIFTING TO THE WEST...NW...AND NE ACROSS THE NORTHERN HALF OF THE FORECAST AREA...BUT REMAINING WEST TO SW OVER THE SOUTHERN HALF. SATELLITE SHOWS A CLOUD BAND ROUGHLY PARALLELING THIS WIND SHIFT ZONE AND BELIEVE THIS IS SHOWS THE SURFACE REFLECTION OF THE 700 MB TROUGH MOVING THROUGH. THIS LINES UP WELL WITH RUC AND NAM PROJECTIONS. DRIER NW FLOW WILL FILTER OVER THE AREA TONIGHT THROUGH THURSDAY... BUT CLEARING WILL BE SHORT-LIVED. PLENTY OF CLOUD IS STREAMING OVER THE TOP OF THE PACNW RIDGE AND SKIES WILL CLOUD UP THURSDAY AND THURSDY NIGHT AS A TROUGH RIDES DOWN THE EAST SIDE OF THAT RIDGE. MODELS ARE WEAKER WITH THIS TROUGH THAT EARLIER SOLUTIONS AND TAKE THE TROUGH A BIT FURTHER EAST. WITH CLEARING SKIES TODAY AND TONIGHT...OVERNIGHT LOW TEMPS WILL BE NEAR OR BELOW FREEZING AT MANY VALLEY LOCATIONS. .LONG-TERM (FRIDAY THROUGH WEDNESDAY)... NEXT SHORTWAVE ON TRACK FOR THE FRI-SAT TIME FRAME. ENERGY WILL DROP SOUTHWARD ON THE DOWNSTREAM SIDE OF THE WEST COAST RIDGE AND THE UPSTREAM SIDE OF A LARGE TROUGH ACROSS THE NATIONS MID-SECTION. MODELS CONTINUE TO BE FAIRLY CONSISTENT WITH THIS WAVE WHICH WILL PRODUCE THE BEST POPS FRI NIGHT. THIS DISTURBANCE WILL BRING A GOOD SHOT OF COLD AIR WITH -26C AT 500 MB OVER THE NORTH BY 12Z SAT. HOWEVER MOISTURE MUCH SHALLOWER THAN PRESENT SYSTEM...SO HAVE ONLY MADE MINOR ADJUSTMENTS TO THE CHANCE/SLIGHT CHANCE OF THE PREVIOUS PACKAGE. NORTHWEST FLOW WILL KEEP A FEW OROGRAPHIC SHOWERS GOING OVER THE NORTHERN DIVIDE THROUGH THE WEEKEND. HOWEVER THE 00Z GFS NO LONGER SHOWS ANOTHER SHORTWAVE FOR SUN NIGHT. INSTEAD THE WESTERN RIDGE SHIFTS INTO THE GREAT BASIN AND THEN OVER THE FORECAST AREA ON MON. THIS WILL BRING A DRYING AND WARMING TREND. THE FLOW FLATTENS BY TUE WITH THE NEXT SHORTWAVE DEVELOPING OVER THE NORTHWEST. THE 00Z GFS SHOWS THIS WAVE APPROACHING THE AREA LATE WED. WITH POOR MODEL CONSISTENCY DURING THIS TIME FRAME WILL NOT CARRY MORE THAT LOW POPS OVER THE NORTH. HIGH TEMPS WILL WARM TO NEAR NORMAL...OR EVEN A LITTLE ABOVE AFTER THE WEEKEND. LOWS WILL REMAIN BLOW NORMAL DUE TO THE DRIER AIR MASS. && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. $$ CJC/EH co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 427 AM MDT WED OCT 18 2006 ...WINTER WEATHER SLOWLY WINDING DOWN IN THE WESTERN COLORADO MOUNTAINS... .SHORT-TERM (TODAY THROUGH THURSDAY NIGHT)... IR SATELLITE SHOWS OROGRAPHIC CLOUDS AND PROBABLY SNOW CONTINUING OVER ERN UT AND WRN C0 MTS. WILL LEAVE THE WINTER WARNINGS AND ADVISORIES GOING TO THE EXPIRATION TIME AT ABOUT SUNRISE TODAY. SNOWFALL AND CLOUD COVER WILL SLOWLY DISSIPATE THROUGH THE REST OF TODAY AND TONIGHT. SFC DATA SHOWS WINDS GRADUALLY SHIFTING TO THE WEST...NW...AND NE ACROSS THE NORTHERN HALF OF THE FORECAST AREA...BUT REMAINING WEST TO SW OVER THE SOUTHERN HALF. SATELLITE SHOWS A CLOUD BAND ROUGHLY PARALLELING THIS WIND SHIFT ZONE AND BELIEVE THIS IS SHOWS THE SURFACE REFLECTION OF THE 700 MB TROUGH MOVING THROUGH. THIS LINES UP WELL WITH RUC AND NAM PROJECTIONS. DRIER NW FLOW WILL FILTER OVER THE AREA TONIGHT THROUGH THURSDAY... BUT CLEARING WILL BE SHORT-LIVED. PLENTY OF CLOUD IS STREAMING OVER THE TOP OF THE PACNW RIDGE AND SKIES WILL CLOUD UP THURSDAY AND THURSDY NIGHT AS A TROUGH RIDES DOWN THE EAST SIDE OF THAT RIDGE. MODELS ARE WEAKER WITH THIS TROUGH THAT EARLIER SOLUTIONS AND TAKE THE TROUGH A BIT FURTHER EAST. WITH CLEARING SKIES TODAY AND TONIGHT...OVERNIGHT LOW TEMPS WILL BE NEAR OR BELOW FREEZING AT MANY VALLEY LOCATIONS. .LONG-TERM (FRIDAY THROUGH WEDNESDAY)... NEXT SHORTWAVE ON TRACK FOR THE FRI-SAT TIME FRAME. ENERGY WILL DROP SOUTHWARD ON THE DOWNSTREAM SIDE OF THE WEST COAST RIDGE AND THE UPSTREAM SIDE OF A LARGE TROUGH ACROSS THE NATIONS MID-SECTION. MODELS CONTINUE TO BE FAIRLY CONSISTENT WITH THIS WAVE WHICH WILL PRODUCE THE BEST POPS FRI NIGHT. THIS DISTURBANCE WILL BRING A GOOD SHOT OF COLD AIR WITH -26C AT 500 MB OVER THE NORTH BY 12Z SAT. HOWEVER MOISTURE MUCH SHALLOWER THAN PRESENT SYSTEM...SO HAVE ONLY MADE MINOR ADJUSTMENTS TO THE CHANCE/SLIGHT CHANCE OF THE PREVIOUS PACKAGE. NORTHWEST FLOW WILL KEEP A FEW OROGRAPHIC SHOWERS GOING OVER THE NORTHERN DIVIDE THROUGH THE WEEKEND. HOWEVER THE 00Z GFS NO LONGER SHOWS ANOTHER SHORTWAVE FOR SUN NIGHT. INSTEAD THE WESTERN RIDGE SHIFTS INTO THE GREAT BASIN AND THEN OVER THE FORECAST AREA ON MON. THIS WILL BRING A DRYING AND WARMING TREND. THE FLOW FLATTENS BY TUE WITH THE NEXT SHORTWAVE DEVELOPING OVER THE NORTHWEST. THE 00Z GFS SHOWS THIS WAVE APPROACHING THE AREA LATE WED. WITH POOR MODEL CONSISTENCY DURING THIS TIME FRAME WILL NOT CARRY MORE THAT LOW POPS OVER THE NORTH. HIGH TEMPS WILL WARM TO NEAR NORMAL...OR EVEN A LITTLE ABOVE AFTER THE WEEKEND. LOWS WILL REMAIN BLOW NORMAL DUE TO THE DRIER AIR MASS. && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...HEAVY SNOW WARNING THROUGH 6 AM MDT TODAY FOR CO ZONES 04/09/10/13. SNOW ADVISORY THROUGH 6 AM MDT TODAY FOR ZONES 03/12/17. SNOW AND BLOWING SNOW ADVISORY THROUGH 6 AM MDT TODAY FOR CO ZONES 18 AND 19. .UT...SNOW ADVISORY THROUGH 6 AM MDT TODAY FOR ZONE 25. $$ CJC/EH co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 848 PM CDT WED OCT 18 2006 .DISCUSSION...COLD FRONT HAS JUST RECENTLY CLEARED FORECAST AREA TO THE SOUTH AND EAST. HOWEVER...ACTIVE SOUTHWEST FLOW ALOFT WILL CONTINUE TO SUPPORT SPOTTY POST FRONTAL SHOWERS OVERNIGHT...MAINLY OVER EASTERN ILLINOIS. FURTHER WEST THE PRECIPITATION SHOULD BE MINIMAL (PATCHY DRIZZLE). LOCAL AND UPSTREAM SOUNDINGS SHOW A STRONG SUBSIDENCE INVERSION THAT WILL KEEP LOW CLOUDS TRAPPED IN THROUGH THE NIGHT...BUT LOW LEVEL COLD ADVECTION BELOW THE INVERSION WILL STILL ALLOW TEMPERATURES TO FALL A BIT BELOW CURRENT FORECAST. GOING FORECAST IN PRETTY GOOD SHAPE. WILL MAKE SOME MINOR ADJUSTMENTS TO GRIDS/ZONES FOR LATEST (MAINLY TEMPERATURE AND PRECIPITATION) TRENDS. && .PREV DISCUSSION... FORECAST CHALLENGES WILL BE WITH THE CHANCES OF PRECIPITATION FOR TONIGHT AND TOMORROW...AND THEN AGAIN THIS WEEKEND. THE NAM/WRF AND THE GFS ARE FINALLY IN GOOD AGREEMENT WITH MOST OF THE FORECAST FIELDS FOR THE NEXT 36 HOURS...BUT THEY ARE SHOWING THEIR DIFFERENCES TOWARD THIS WEEKEND. THE GFS IS QUICKER WITH THE NEXT COLD FRONT...WHILE THE NAM/WRF IS STRONGER WITH THE SHORTWAVE AND ASSOCIATED SURFACE LOW. THE QUICKER AND SOMEWHAT WEAKER GFS IS PREFERRED IN THE FAST UPPER LEVEL FLOW PATTERN WHICH WILL DOMINATE THE WEATHER THE NEXT SEVERAL DAYS. SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT... AS MENTIONED ABOVE...THE GFS AND NAM/WRF ARE IN AGREEMENT. HOWEVER... THEY ARE OVERDOING THEIR DEPICTION OF THE DEEP MOISTURE AND PRECIPITATION OUTPUT FOR TONIGHT INTO EARLY THURSDAY MORNING. ALSO... VERY WEAK LIFT WILL BE AVAILABLE FOR THIS SYSTEM SO RAINFALL WILL BE LIGHT AND QUITE SCATTERED. AS A RESULT...WILL BE DROPPING THE POPS FROM LIKELY TO CHANCE OR SLIGHT CHANCE...WITH THE BEST PRECIP EXPECTED TO BE NORTH OF THE FORECAST AREA. THE 18Z RUC CONFIRMS THIS THINKING WITH ONLY MINOR AMOUNTS OF RAINFALL DEPICTED IN THE NORTHERN HALF OF THE FORECAST AREA. THERE WILL BE A BETTER CHANCE FOR PRECIPITATION TOMORROW ALONG AND EAST OF I-55 AS A SHORTWAVE MOVES ACROSS THE MID MS VALLEY ACROSS SOUTH CENTRAL IL. WILL MAINTAIN LIKELY OR HIGHER POPS ALONG AND EAST OF I-57... WITH ONLY CHANCE POPS ROUGHLY ALONG I-55. HIGH PRESSURE NOSING INTO CENTRAL IL THURSDAY NIGHT WILL RESULT IN PARTIAL CLEARING AND END THE PRECIP IN EASTERN IL. THE HIGH PRESSURE WILL QUICKLY MOVE ACROSS IL FRIDAY...RESULTING IN QUIET WEATHER WITH SEASONABLY COOL TEMPS. LONG TERM...SATURDAY THROUGH WEDNESDAY... THE NEXT CHANCE FOR PRECIPITATION WILL BE SATURDAY IN THE WESTERN HALF OF IL...AND ACROSS MUCH OF THE STATE SAT NIGHT. THE NEW GFS HAS TRENDED A BIT SLOWER WITH THIS SYSTEM...BIT STILL REMAINS AHEAD OF THE OTHER FORECAST MODELS. WILL NEED TO TRIM BACK POPS IN EASTERN IL FOR SATURDAY. WILL ALSO LINGER THE PRECIP A BIT INTO SUNDAY MAINLY NORTH OF A LINE FROM GBG-LINCOLN-TERRE HAUTE. COULD BE A BIT OF SNOW MIXED WITH THE RAIN IN NORTHERN PARTS OF THE FORECAST AREA AS THIS NEXT SYSTEM DRAGS COLDER AIR INTO THE REGION. QUIET WEATHER WILL RESUME THE FIRST PART OF NEXT WEEK...BUT WILL BE A BIT COOLER THAN NORMAL...BUT NOT AS COLD AS WHAT THE GFS LONG RANGE IS INDICATING WITH ITS DEEP POLAR VORTEX IN THE GREAT LAKES. PREFER THE EUROPEAN MODEL DEPICTION OF A BROADER TROF AND MORE OF A PACIFIC AIRMASS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ BAK/MILLER il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 245 PM CDT WED OCT 18 2006 .DISCUSSION... FORECAST CHALLENGES WILL BE WITH THE CHANCES OF PRECIPITATION FOR TONIGHT AND TOMORROW...AND THEN AGAIN THIS WEEKEND. THE NAM/WRF AND THE GFS ARE FINALLY IN GOOD AGREEMENT WITH MOST OF THE FORECAST FIELDS FOR THE NEXT 36 HOURS...BUT THEY ARE SHOWING THEIR DIFFERENCES TOWARD THIS WEEKEND. THE GFS IS QUICKER WITH THE NEXT COLD FRONT...WHILE THE NAM/WRF IS STRONGER WITH THE SHORTWAVE AND ASSOCIATED SURFACE LOW. THE QUICKER AND SOMEWHAT WEAKER GFS IS PREFERRED IN THE FAST UPPER LEVEL FLOW PATTERN WHICH WILL DOMINATE THE WEATHER THE NEXT SEVERAL DAYS. SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT... AS MENTIONED ABOVE...THE GFS AND NAM/WRF ARE IN AGREEMENT. HOWEVER... THEY ARE OVERDOING THEIR DEPICTION OF THE DEEP MOISTURE AND PRECIPITATION OUTPUT FOR TONIGHT INTO EARLY THURSDAY MORNING. ALSO... VERY WEAK LIFT WILL BE AVAILABLE FOR THIS SYSTEM SO RAINFALL WILL BE LIGHT AND QUITE SCATTERED. AS A RESULT...WILL BE DROPPING THE POPS FROM LIKELY TO CHANCE OR SLIGHT CHANCE...WITH THE BEST PRECIP EXPECTED TO BE NORTH OF THE FORECAST AREA. THE 18Z RUC CONFIRMS THIS THINKING WITH ONLY MINOR AMOUNTS OF RAINFALL DEPICTED IN THE NORTHERN HALF OF THE FORECAST AREA. THERE WILL BE A BETTER CHANCE FOR PRECIPITATION TOMORROW ALONG AND EAST OF I-55 AS A SHORTWAVE MOVES ACROSS THE MID MS VALLEY ACROSS SOUTH CENTRAL IL. WILL MAINTAIN LIKELY OR HIGHER POPS ALONG AND EAST OF I-57... WITH ONLY CHANCE POPS ROUGHLY ALONG I-55. HIGH PRESSURE NOSING INTO CENTRAL IL THURSDAY NIGHT WILL RESULT IN PARTIAL CLEARING AND END THE PRECIP IN EASTERN IL. THE HIGH PRESSURE WILL QUICKLY MOVE ACROSS IL FRIDAY...RESULTING IN QUIET WEATHER WITH SEASONABLY COOL TEMPS. LONG TERM...SATURDAY THROUGH WEDNESDAY... THE NEXT CHANCE FOR PRECIPITATION WILL BE SATURDAY IN THE WESTERN HALF OF IL...AND ACROSS MUCH OF THE STATE SAT NIGHT. THE NEW GFS HAS TRENDED A BIT SLOWER WITH THIS SYSTEM...BIT STILL REMAINS AHEAD OF THE OTHER FORECAST MODELS. WILL NEED TO TRIM BACK POPS IN EASTERN IL FOR SATURDAY. WILL ALSO LINGER THE PRECIP A BIT INTO SUNDAY MAINLY NORTH OF A LINE FROM GBG-LINCOLN-TERRE HAUTE. COULD BE A BIT OF SNOW MIXED WITH THE RAIN IN NORTHERN PARTS OF THE FORECAST AREA AS THIS NEXT SYSTEM DRAGS COLDER AIR INTO THE REGION. QUIET WEATHER WILL RESUME THE FIRST PART OF NEXT WEEK...BUT WILL BE A BIT COOLER THAN NORMAL...BUT NOT AS COLD AS WHAT THE GFS LONG RANGE IS INDICATING WITH ITS DEEP POLAR VORTEX IN THE GREAT LAKES. PREFER THE EUROPEAN MODEL DEPICTION OF A BROADER TROF AND MORE OF A PACIFIC AIRMASS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MILLER il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1054 AM CDT WED OCT 18 2006 .DISCUSSION... LOOKING AT A COUPLE OTHER THINGS...HAVE DECIDED TO CHANGE TEMPS FOR TODAY...BRINGING DOWN MAX TEMPS INVOF THE FRONT. PLENTY OF COLD AIR MOVING INTO AREAS NW OF ILLINOIS RIVER. PERSISTENT CLOUD COVER WILL HELP KEEP SE FROM WARMING TOO MUCH. ZONE UPDATE AROUND THE CORNER. && .PREV DISCUSSION... FORECAST CHALLENGE WILL BE SPEED OF COLD FRONT TODAY/TONIGHT AND ASSOCIATED CONVECTION CHANCES...AND IF THEY LINGER INTO THU. ALSO ADDRESSING SHARP TEMPERATURE GRADIENT FROM NW TO SE FOR HIGHS TODAY. THEN LOOKING AT NEXT WX SYSTEM THIS WEEKEND WITH NEXT CHANCE OF SHOWERS. 00Z SHORT RANGE MODELS APPEAR QUICKER WITH COLD FRONT THAN YESTERDAYS MODEL RUNS ESPECIALLY THE NAM/WRF MODEL. NAM/WRF IS SLOWER WITH FRONT THEN GFS AND NGM AND PREFERRED THE SLOWER NAM/WRF BEING A SURFACE WAVE IS MOVING UP ALONG THE FRONT. 07Z/2 AM SURFACE MAP HAS COLD FRONT SLICING ACROSS NW IL AND JUST PASSED GALESBURG WHERE SW WINDS SHIFTED NW. SHORT TERM...TODAY THROUGH FRIDAY NIGHT... 07Z/2 AM SURFACE ANALYSIS SHOWS 998 MB LOW PRESSURE JUST NORTH OF LAKE SUPERIOR WITH A COLD FRONT EXTENDING SOUTH ACROSS EASTER WI INTO NW IL...WEST OF THE IL RIVER...THROUGH NW MO TO 1004 MB LOW PRESSURE IN SW OK. RADAR MOSAIC SHOWS POST FRONTAL SCATTERED SHOWERS OVER NW IOWA. NEARLY OVERCAST LOW CLOUDS CONTINUE TO BLANKET IL WITH SOME BREAKS. LIKE AT FLORA WHERE DENSE FOG DEVELOPED WITH VSBY 1/2 MILE. TEMPS WERE IN THE MID TO UPPER 50S AND DEWPOINT NEAR OR A FEW DEGREES BELOW TEMPS...SO LOW LEVELS ARE PRETTY MOIST. RUC AND NAM/WRF BRING THE FRONT SLOWLY EAST TO ALONG THE IL RIVER BY NOON...THEN NAM/WRF BRING THE FRONT EAST OF I-57 BY SUNSET AND THROUGH LAWRENCEVILLE BY 09Z/4 AM TONIGHT. GFS AND NGM ARE ABOUT 6 HOURS QUICKER WITH THE FRONT LIKE THEY WERE YESTERDAYS RUNS. SHOWER CHANCES WILL BE BEHIND THE FRONT AND CHANCE THIS MORNING FROM THE IL RIVER NW AND SPREADING EAST TOWARD I-57 DURING THIS AFTERNOON WHILE LIKELY CHANCES THIS AFTERNOON FROM THE IL RIVER NW. HAVE LIKELY CHANCE OF SHOWERS TONIGHT THOUGH MAINLY NW HALF THIS EVENING AND SE HALF OVERNIGHT AND CONTINUED CHANCE OF THUNDER OVER SE IL TONIGHT. SPC HAS RISK OF THUNDER GENERALLY EAST OF I-55 LATER TODAY/TONIGHT AND JUST SE OF LAWRENCEVILLE THU. MODELS TENDING TO KEEP LOW CLOUDS AROUND INTO TODAY AND WENT MOSTLY CLOUDY OVERALL. HIGHS VARY FROM UPPER 50S FAR NW BY GALESBURG...UPPER 60S ALONG I-55...TO THE MID 70S OVER SE IL. MODELS SIMILAR IN SHOWING SURFACE LOW EJECTING NE FROM OK INTO KY THU AND KEEPING QPF OVER AREAS EAST OF I-55 THU SO INCREASED CLOUDS AND POPS HERE WITH LIKELY CHANCES OVER EASTERN IL AND ISOLATED THUNDER. LINGERED 30 PERCENT CHANCE OF SHOWERS FROM DANVILLE TO EFFINGHAM EAST THU EVENING...THEN DRY. COOLER THU WITH BELOW NORMAL HIGHS IN THE 50S. NORMAL HIGHS ARE IN THE MID TO UPPER 60S. WILL BE IN BETWEEN WX SYSTEMS FRI WITH PARTLY CLOUDY SKIES AND HIGHS 55 TO 60F. LONG TERM...SATURDAY THROUGH WEDNESDAY... NO BIG CHANGES TO EXTENDED FORECAST WITH NEXT WX SYSTEM EXPECTED TO INCREASE SHOWER CHANCES SAT ESPECIALLY IN THE WEST BY AFTERNOON AND INTO EASTERN IL LATER SAT AFTERNOON. HAVE GOOD CHANCE OF SHOWERS SAT NIGHT AND TEMP PROFILES COULD GET COOL ENOUGH FROM PEORIA NORTH TO SUPPORT A CHANCE OF LIGHT SNOW WITH THE RAIN LATER SAT NIGHT. REINFORCING COOLER AIR ARRIVES ON NW BREEZES SUNDAY WITH A LINGERING CHANCE OF SHOWERS. DRY WX RETURNS EARLY NEXT WORK WEEK AS BELOW NORMAL TEMPS PREVAIL WITH HIGHS IN THE 50S. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ HJS/HUETTL il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1021 AM CDT WED OCT 18 2006 .DISCUSSION... BROAD TROF OVER WRN CONUS THIS MORNING...WITH RATHER FAST SWRLY FLOW. COLD FRONT TRYING TO PUSH THROUGH THE AREA...AND SOME SPRINKLES OUT AHEAD OF IT...BUT FOR THE MOST PART...PRECIP IS POST-FRONTAL AND HANGING BACK IN ERN IA AND FAR NWRN IL. GOING FORECAST IS LOOKING GOOD. NO REASON TO UPDATE AT THIS TIME. MAY SEND OUT A ZONE UPDATE CLOSER TO NOON TO ELIMINATE MORNING WORDING. && .PREV DISCUSSION... FORECAST CHALLENGE WILL BE SPEED OF COLD FRONT TODAY/TONIGHT AND ASSOCIATED CONVECTION CHANCES...AND IF THEY LINGER INTO THU. ALSO ADDRESSING SHARP TEMPERATURE GRADIENT FROM NW TO SE FOR HIGHS TODAY. THEN LOOKING AT NEXT WX SYSTEM THIS WEEKEND WITH NEXT CHANCE OF SHOWERS. 00Z SHORT RANGE MODELS APPEAR QUICKER WITH COLD FRONT THAN YESTERDAYS MODEL RUNS ESPECIALLY THE NAM/WRF MODEL. NAM/WRF IS SLOWER WITH FRONT THEN GFS AND NGM AND PREFERRED THE SLOWER NAM/WRF BEING A SURFACE WAVE IS MOVING UP ALONG THE FRONT. 07Z/2 AM SURFACE MAP HAS COLD FRONT SLICING ACROSS NW IL AND JUST PASSED GALESBURG WHERE SW WINDS SHIFTED NW. SHORT TERM...TODAY THROUGH FRIDAY NIGHT... 07Z/2 AM SURFACE ANALYSIS SHOWS 998 MB LOW PRESSURE JUST NORTH OF LAKE SUPERIOR WITH A COLD FRONT EXTENDING SOUTH ACROSS EASTER WI INTO NW IL...WEST OF THE IL RIVER...THROUGH NW MO TO 1004 MB LOW PRESSURE IN SW OK. RADAR MOSAIC SHOWS POST FRONTAL SCATTERED SHOWERS OVER NW IOWA. NEARLY OVERCAST LOW CLOUDS CONTINUE TO BLANKET IL WITH SOME BREAKS. LIKE AT FLORA WHERE DENSE FOG DEVELOPED WITH VSBY 1/2 MILE. TEMPS WERE IN THE MID TO UPPER 50S AND DEWPOINT NEAR OR A FEW DEGREES BELOW TEMPS...SO LOW LEVELS ARE PRETTY MOIST. RUC AND NAM/WRF BRING THE FRONT SLOWLY EAST TO ALONG THE IL RIVER BY NOON...THEN NAM/WRF BRING THE FRONT EAST OF I-57 BY SUNSET AND THROUGH LAWRENCEVILLE BY 09Z/4 AM TONIGHT. GFS AND NGM ARE ABOUT 6 HOURS QUICKER WITH THE FRONT LIKE THEY WERE YESTERDAYS RUNS. SHOWER CHANCES WILL BE BEHIND THE FRONT AND CHANCE THIS MORNING FROM THE IL RIVER NW AND SPREADING EAST TOWARD I-57 DURING THIS AFTERNOON WHILE LIKELY CHANCES THIS AFTERNOON FROM THE IL RIVER NW. HAVE LIKELY CHANCE OF SHOWERS TONIGHT THOUGH MAINLY NW HALF THIS EVENING AND SE HALF OVERNIGHT AND CONTINUED CHANCE OF THUNDER OVER SE IL TONIGHT. SPC HAS RISK OF THUNDER GENERALLY EAST OF I-55 LATER TODAY/TONIGHT AND JUST SE OF LAWRENCEVILLE THU. MODELS TENDING TO KEEP LOW CLOUDS AROUND INTO TODAY AND WENT MOSTLY CLOUDY OVERALL. HIGHS VARY FROM UPPER 50S FAR NW BY GALESBURG...UPPER 60S ALONG I-55...TO THE MID 70S OVER SE IL. MODELS SIMILAR IN SHOWING SURFACE LOW EJECTING NE FROM OK INTO KY THU AND KEEPING QPF OVER AREAS EAST OF I-55 THU SO INCREASED CLOUDS AND POPS HERE WITH LIKELY CHANCES OVER EASTERN IL AND ISOLATED THUNDER. LINGERED 30 PERCENT CHANCE OF SHOWERS FROM DANVILLE TO EFFINGHAM EAST THU EVENING...THEN DRY. COOLER THU WITH BELOW NORMAL HIGHS IN THE 50S. NORMAL HIGHS ARE IN THE MID TO UPPER 60S. WILL BE IN BETWEEN WX SYSTEMS FRI WITH PARTLY CLOUDY SKIES AND HIGHS 55 TO 60F. LONG TERM...SATURDAY THROUGH WEDNESDAY... NO BIG CHANGES TO EXTENDED FORECAST WITH NEXT WX SYSTEM EXPECTED TO INCREASE SHOWER CHANCES SAT ESPECIALLY IN THE WEST BY AFTERNOON AND INTO EASTERN IL LATER SAT AFTERNOON. HAVE GOOD CHANCE OF SHOWERS SAT NIGHT AND TEMP PROFILES COULD GET COOL ENOUGH FROM PEORIA NORTH TO SUPPORT A CHANCE OF LIGHT SNOW WITH THE RAIN LATER SAT NIGHT. REINFORCING COOLER AIR ARRIVES ON NW BREEZES SUNDAY WITH A LINGERING CHANCE OF SHOWERS. DRY WX RETURNS EARLY NEXT WORK WEEK AS BELOW NORMAL TEMPS PREVAIL WITH HIGHS IN THE 50S. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ HJS/HUETTL il AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CARIBOU ME 935 PM EDT WED OCT 18 2006 .SYNOPSIS...WEAK HIGH PRESSURE WILL BRIEFLY BUILD SOUTH OF THE REGION OVERNIGHT INTO THURSDAY THEN A WEAK COLD FRONT WILL PUSH INTO THE AREA EARLY THURSDAY EVENING. LOW PRESSURE TRACKING ALONG THE FRONT WILL APPROACH LATE THURSDAY NIGHT AND MOVE TOWARD THE AREA ON FRIDAY. THE LOW IS EXPECTED TO MOVE INTO THE MARITIMES FRIDAY NIGHT. && .SHORT TERM /OVERNIGHT/... CLOUD COVER HAS BEEN PERSISTENT OVER THE AREA AND SHOULD CONTINUE TO HOLD ON OVERNIGHT SO HAVE KEPT MOSTLY CLOUDY WORDING FOR THE ENTIRE REGION WITH DOWNEAST AREAS BECOMING PARTLY CLOUDY LATE. HAVE ALSO DECREASED PRECIPITATION CHANCES BUT KEPT MENTION OF PATCHY LIGHT DRIZZLE ASSOCIATED WITH THE LOW STRATUS PREVALENT IN NORTHERN AND CENTRAL ZONES. ALSO INCLUDED LOCALLY DENSE FOG FOR THE ENTIRE REGION. && .MARINE... NO CHANGES. && .PREVIOUS DISCUSSION... SHORT TERM /TONIGHT THROUGH FRIDAY/... DECIDED ON THE RUC IN THE NEAR TERM THROUGH EARLY TONIGHT BASED ON HOW IT IS HANDLING THINGS ATTM PER RADAR/SATL IMAGERY & METARS. AFTER THAT...LEANED PRETTY CLOSE THE GFS. I SCALED BACK ITS QPF BY 1/10 OF AN INCH FOR FRI W/ITS FCST OF SFC LOW MIGRATING THROUGH THE STATE. THIS IS TO ALIGN CLOSET TO OUR NEIGHBORS TO THE S. HUNG ONTO SOME SHOWERS & DRIZZLE MAINLY ACROSS THE N THIS EVENING & THEN DRY THINGS OUT AFT 06Z. ADDED FOG EVERYWHERE TONIGHT W/THE MOST DENSE FOG ACROSS DOWNEAST & THE COAST DUE TO SOME CLEARING. SATL IMAGERY SHOWED DRY SLOT EDGING NEWD. THIS WILL NEED TO BE WATCHED THIS EVENING AS NRN AREAS COULD SEE MORE FOG IF CLOUDS THIN MORE. PREV FCST MINS WERE ACCEPTED W/SOME SLIGHT ADJUSTMENTS DOWNEAST TO SCALE TEMPS BACK DUE TO THAT CLEARING. WEAK RIDGING WILL TAKE PLACE THROUGH MIDDAY THURSDAY & THEN A COLD FRONT WILL MOVE ACROSS THE REGION LATE THURSDAY INTO THURSDAY EVENING & THEN STALLS FROM JUST SE OF CAR EXTENDING DOWN INTO THE BGR REGION FRIDAY MORNING. BROUGHT SHOWERS BACK INTO THE REGION THURSDAY AFTERNOON INTO THE EVENING. A MORE STEADIER RAIN IS EXPECTED ON FRIDAY AS THE GFS SHOWS A SIGNIFICANT SFC LOW DEVELOPING ON THE FRONT & LIFTING NE INTO THE REGION. THE NAM/WRF IS CLOSE TO THE GFS WHILE THE 72 HR GEM IS FURTHER E & MUCH WEAKER. SOME DECENT WAA W/A FAIRLY STG MID-LVL SPD MAX TO ADD SOME SUPPORT FOR SOME SIGNIFICANT RAFL. WE/LL SEE HOW LATER MDL RUNS HANDLE THIS EVENT. PREV FCST TEMPS THURSDAY INTO FRIDAY LOOKED GOOD. ONLY SLGT ADJUSTMENTS WERE MADE MAINLY ACROSS THE NRN AREAS. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LOADED HPC GRIDS FOR THE EXTENDED AND STAYED VERY CLOSE TO THEIR SOLUTION WHICH WAS CLOSE TO THE GFS/ECMWF LATEST RUNS. LOW PRESSURE WILL MOVE THROUGH THE SOUTHEAST CORNER OF THE STATE FRIDAY NIGHT WITH POSSIBLE HEAVY RAIN AS UPPER TROUGH NEGATIVELY TILTS OVER THE STATE. GFS INDICATING AS MUCH AS 2 INCHES OF RAIN WITH AROUND AN INCH FROM THE NAM SO USED A COMPROMISE BETWEEN THE TWO FOR NOW. UPPER TROUGH MOVES NORTHEAST OF THE STATE SATURDAY WITH BRISK NORTHWEST FLOW TO FOLLOW. SHOWERS MAY LINGER ACROSS THE NORTH WITH CLOUDS UNDER CYCLONIC FLOW AT ALL LEVELS INTO SATURDAY. SURFACE RIDGE BUILDS ACROSS THE STATE SUNDAY AS UPPER RIDGE CRESTS NEW ENGLAND. CLOUDS ON THE INCREASE LATE SUNDAY AS ANOTHER LOW PRESSURE APPROACHES FROM THE WEST. THIS LOW TRACKS THROUGH THE GULF OF MAINE ON MONDAY WITH ANOTHER ROUND OF SHOWERS CONTINUING INTO TUESDAY AVIATION... IFR ACROSS THE NRN SITES INTO THIS EVENING W/MVFR ACROSS KBGR & KBHB. WATCHING SATL & LATEST CIG PLOTS & WE COULD SEE ALL TAF SITE GO VFR FOR A WHILE TONIGHT (BY AROUND 02Z). TRIED TO SHOW THIS IN THE 18Z TAFS. THINKING HERE IS THAT FOG WILL COME BACK IN LATER TONIGHT W/THE MOST DENSE TOWARD KBGR & KBHB AS VBYS DOWN THERE GO DOWN TO MVFR TO PSBL IFR. EXPECTING NRN SITES (KCAR-KPQI-KHUL)TO GO BACK TO MVFR AFT 07Z. MARINE... SHORT TERM: DECIDED TO GO W/THE SCA FOR HAZARDOUS SEAS THROUGH LATE TONIGHT. LATEST MARINE OBS SHOWED SEAS AT 6-7 FT & WINDS DOWN TO 15-20 KTS. USED THE GFS W/DIRECTION VEERING AROUND TO THE SW & SHOULD GO WNW THIS EVENING. SPDS SHOULD CONTINUE TO COME DOWN TONIGHT ALONG W/THE SEAS. NO HEADLINES EXPECTED ON THU INTO EARLY FRI. WINDS BACK TO SW ON THU & THEN GO S BY FRI W/A GRADUAL INCREASE IN SPEEDS. THERE IS THE POSSIBILITY THAT AN SCA COULD BE NEEDED BY FRI AFTERNOON AS SEAS BEGIN TO BUILD. USED WAVEWATCH & A SLGT ADJUSTMENT TO START OUT TONIGHT. LONG TERM: SCA POSSIBLE FOR A COUPLE OF HOURS FRIDAY EVENING IN SOUTHERLY FLOW IN ADVANCE OF LOW PRESSURE MOVING ALONG THE MAINE COAST. AS LOW MOVES NE OF THE STATE SATURDAY...A STRONG SCA OR POSSIBLE GALE MAY BE NEEDED IN THE COLD AIR ADVECTION FOLLOWING THE LOW UNDER WESTERLY FLOW. CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FOR ANZ050 UNTIL 6 AM THURSDAY. && $$ UPDATE...WEITLICH SHORT TERM/MARINE...HEWITT LONG TERM/MARINE...FOSTER AVIATION...HEWITT/FOSTER me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 324 PM EDT WED OCT 18 2006 .SYNOPSIS...WEAK HIGH PRESSURE WILL BRIEFLY BUILD SOUTH OF THE REGION TONIGHT INTO THURSDAY THEN A WEAK COLD FRONT WILL PUSH INTO THE AREA EARLY THURSDAY EVENING. LOW PRESSURE TRACKING ALONG THE FRONT WILL APPROACH LATE THURSDAY NIGHT AND MOVE TOWARD THE AREA ON FRIDAY. THE LOW IS EXPECTED TO MOVE INTO THE MARITIMES FRIDAY NIGHT. && .SHORT TERM /TONIGHT THROUGH FRIDAY/... DECIDED ON THE RUC IN THE NEAR TERM THROUGH EARLY TONIGHT BASED ON HOW IT IS HANDLING THINGS ATTM PER RADAR/SATL IMAGERY & METARS. AFTER THAT...LEANED PRETTY CLOSE THE GFS. I SCALED BACK ITS QPF BY 1/10 OF AN INCH FOR FRI W/ITS FCST OF SFC LOW MIGRATING THROUGH THE STATE. THIS IS TO ALIGN CLOSET TO OUR NEIGHBORS TO THE S. HUNG ONTO SOME SHOWERS & DRIZZLE MAINLY ACROSS THE N THIS EVENING & THEN DRY THINGS OUT AFT 06Z. ADDED FOG EVERYWHERE TONIGHT W/THE MOST DENSE FOG ACROSS DOWNEAST & THE COAST DUE TO SOME CLEARING. SATL IMAGERY SHOWED DRY SLOT EDGING NEWD. THIS WILL NEED TO BE WATCHED THIS EVENING AS NRN AREAS COULD SEE MORE FOG IF CLOUDS THIN MORE. PREV FCST MINS WERE ACCEPTED W/SOME SLIGHT ADJUSTMENTS DOWNEAST TO SCALE TEMPS BACK DUE TO THAT CLEARING. WEAK RIDGING WILL TAKE PLACE THROUGH MIDDAY THURSDAY & THEN A COLD FRONT WILL MOVE ACROSS THE REGION LATE THURSDAY INTO THURSDAY EVENING & THEN STALLS FROM JUST SE OF CAR EXTENDING DOWN INTO THE BGR REGION FRIDAY MORNING. BROUGHT SHOWERS BACK INTO THE REGION THURSDAY AFTERNOON INTO THE EVENING. A MORE STEADIER RAIN IS EXPECTED ON FRIDAY AS THE GFS SHOWS A SIGNIFICANT SFC LOW DEVELOPING ON THE FRONT & LIFTING NE INTO THE REGION. THE NAM/WRF IS CLOSE TO THE GFS WHILE THE 72 HR GEM IS FURTHER E & MUCH WEAKER. SOME DECENT WAA W/A FAIRLY STG MID-LVL SPD MAX TO ADD SOME SUPPORT FOR SOME SIGNIFICANT RAFL. WE/LL SEE HOW LATER MDL RUNS HANDLE THIS EVENT. PREV FCST TEMPS THURSDAY INTO FRIDAY LOOKED GOOD. ONLY SLGT ADJUSTMENTS WERE MADE MAINLY ACROSS THE NRN AREAS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LOADED HPC GRIDS FOR THE EXTENDED AND STAYED VERY CLOSE TO THEIR SOLUTION WHICH WAS CLOSE TO THE GFS/ECMWF LATEST RUNS. LOW PRESSURE WILL MOVE THROUGH THE SOUTHEAST CORNER OF THE STATE FRIDAY NIGHT WITH POSSIBLE HEAVY RAIN AS UPPER TROUGH NEGATIVELY TILTS OVER THE STATE. GFS INDICATING AS MUCH AS 2 INCHES OF RAIN WITH AROUND AN INCH FROM THE NAM SO USED A COMPROMISE BETWEEN THE TWO FOR NOW. UPPER TROUGH MOVES NORTHEAST OF THE STATE SATURDAY WITH BRISK NORTHWEST FLOW TO FOLLOW. SHOWERS MAY LINGER ACROSS THE NORTH WITH CLOUDS UNDER CYCLONIC FLOW AT ALL LEVELS INTO SATURDAY. SURFACE RIDGE BUILDS ACROSS THE STATE SUNDAY AS UPPER RIDGE CRESTS NEW ENGLAND. CLOUDS ON THE INCREASE LATE SUNDAY AS ANOTHER LOW PRESSURE APPROACHES FROM THE WEST. THIS LOW TRACKS THROUGH THE GULF OF MAINE ON MONDAY WITH ANOTHER ROUND OF SHOWERS CONTINUING INTO TUESDAY && .AVIATION... IFR ACROSS THE NRN SITES INTO THIS EVENING W/MVFR ACROSS KBGR & KBHB. WATCHING SATL & LATEST CIG PLOTS & WE COULD SEE ALL TAF SITE GO VFR FOR A WHILE TONIGHT (BY AROUND 02Z). TRIED TO SHOW THIS IN THE 18Z TAFS. THINKING HERE IS THAT FOG WILL COME BACK IN LATER TONIGHT W/THE MOST DENSE TOWARD KBGR & KBHB AS VBYS DOWN THERE GO DOWN TO MVFR TO PSBL IFR. EXPECTING NRN SITES (KCAR-KPQI-KHUL)TO GO BACK TO MVFR AFT 07Z. && .MARINE... SHORT TERM: DECIDED TO GO W/THE SCA FOR HAZARDOUS SEAS THROUGH LATE TONIGHT. LATEST MARINE OBS SHOWED SEAS AT 6-7 FT & WINDS DOWN TO 15-20 KTS. USED THE GFS W/DIRECTION VEERING AROUND TO THE SW & SHOULD GO WNW THIS EVENING. SPDS SHOULD CONTINUE TO COME DOWN TONIGHT ALONG W/THE SEAS. NO HEADLINES EXPECTED ON THU INTO EARLY FRI. WINDS BACK TO SW ON THU & THEN GO S BY FRI W/A GRADUAL INCREASE IN SPEEDS. THERE IS THE POSSIBILITY THAT AN SCA COULD BE NEEDED BY FRI AFTERNOON AS SEAS BEGIN TO BUILD. USED WAVEWATCH & A SLGT ADJUSTMENT TO START OUT TONIGHT. LONG TERM: SCA POSSIBLE FOR A COUPLE OF HOURS FRIDAY EVENING IN SOUTHERLY FLOW IN ADVANCE OF LOW PRESSURE MOVING ALONG THE MAINE COAST. AS LOW MOVES NE OF THE STATE SATURDAY...A STRONG SCA OR POSSIBLE GALE MAY BE NEEDED IN THE COLD AIR ADVECTION FOLLOWING THE LOW UNDER WESTERLY FLOW. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FOR ANZ050 UNTIL 6 AM THURSDAY. && $$ SHORT TERM/MARINE...HEWITT LONG TERM/MARINE...FOSTER AVIATION...HEWITT/FOSTER me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 925 PM EDT WED OCT 18 2006 .UPDATE... 00Z RAOBS/WV IMAGERY AND RUC ANALYSIS SHOW SHRTWV LIFTING NEWD FM WI INTO THE UPR GRT LKS. AREA OF STEADY RA OVER THE SCNTRL ZNS MIXED WITH SN/PL ON ITS WRN FLANK...IN SHARP DPVA/H85-5 QVECTOR CNVGC/H7 FGEN/UPR DVGC IN LEFT EXIT OF SUPPORTING UPR JET...HAS MOVED INTO THE ERN ZNS. 00Z GRG SDNG SHOWS FAIRLY HI RH SFC-H5. LIGHTER MIXED -RASNPL OVER THE W TENDING TO DIMINISH AS DRYING ALF PER WV IMAGERY BEHIND THE FGEN/ QVECTOR CNVGC SWEEPING INTO THAT AREA. BUT LO CLD LINGERS EVEN WHERE PCPN HAS ENDED WITH 00Z INL/MPX SDNGS SHOWING HI LLVL MSTR. QUITE A BIT OF MSTR INDICATED BY WV/IR IMAGERY OVER MN COINCIDENT WITH ANOTHER SHRTWV NOW MOVING INTO THE WRN PART OF THE STATE...AND SOME STNS IN THE NRN HALF OF THE STATE HAVE RPRTD -SNRA THIS EVNG. HOWEVER...00Z INL/MPX SDNGS SHOW HIER RH CONFINED BLO INVRN ARND H825. LOWEST TEMP IN SUB INVRN LYR AT INL -8C. MAIN FCST CONCERNS TNGT ARE PCPN TRENDS. LATEST RUC/GFS SHOW VIGOROUS DYNAMICS IN ADVANCE OF WI SHRTWV PULLING E OF ERY ARND 05Z. SO ONGOING PCPN SHOULD DIMINISH BY MIDNGT IN GOOD AGREEMENT WITH RADAR TRENDS. GFS/RUC SHOW RELATIVELY WEAK H85-5 QVECTOR CNVGC (PVA COUNTERACTED BY CAD) ASSOCIATED WITH TRAILING SHRTWV NOW OVER MN RETURNING AFT 06Z...BUT MODEL SDNGS INDICATE DRYING ALF WITH LWRG INVRN HGT AT THE SAME TIME...IN FVRBL COMPARISON WITH 00Z INL SDNG. ALTHOUGH INCOMING AIRMASS (-8C INVRN BASE TEMP AT INL VS 9C WATER TEMP OVER THE WRN LK) IS SUFFICIENTLY COLD FOR LK EFFECT PCPN... RELATIVELY POOR SN GROWTH WITH MOIST LYR WARMER THAN -10C SHUD LIMIT PCPN INTENSITY IN THE CAD PATTERN IN THE WAKE OF SHRTWVS. BUT WL MAINTAIN MENTION OF SCT -SHSNRA TO ACCOUNT FOR HI LLVL RH UPSTREAM AND DECENT OVERWATER INSTABILITY IN UPSLOPE AREAS OF THE W AND OVER THE E FVRD BY EXPECTED NW FLOW IN THE WAKE OF THESE SHRTWVS. NO CHGS APPEAR NECESSARY IN FCST LO TEMPS. KC .PREVIOUS DISCUSSION (ISSUED AT 430 PM EDT)... .THROUGH 00Z SUNDAY... PRECIPITATION IS NOW ENTERING THE FA FROM THE SOUTH. PRECIP. TYPE HAS BEEN MAINLY RAIN...THOUGH HAVE HAD SOME REPORTS OF SLEET IN WI...SO DECIDED TO MENTION THE POTENTIAL FOR SLEET BEFORE MIDNIGHT IN THE GRIDS...MAINLY ACROSS THE CENTRAL. DEWPOINTS ARE FREEZING OR LOWER ACROSS THE WEST...SO NOT MUCH EVAPORATIONAL COOLING WILL BE NEEDED TO TAKE PLACE FOR SLEET AND/OR SNOW TO BEGIN. REFLECTIVITY ECHOES OVER CENTRAL WISCONSIN LOOK RATHER IMPRESSIVE WITH 40-50 DBZ VALUES SHOWING UP OVER MARSHFIELD AND WAUSAU AREAS. NO REPORTS YET OF HEAVY RAIN...ONLY MODERATE AT BEST...WITH MOST OF THE RAIN FALLING AS LIGHT PRECIPITATION...THINK SOME OF HIGHER REFLECTIVITY VALUES MAY BE DUE TO BRIGHT BANDING ISSUES...HOWEVER THIS ALSO INDICATES THAT MIXED PRECIP. MAY BE FALLING OVER AREAS OF CENTRAL WI...THOUGH HAVE ONLY HAD THE ONE REPORT SO FAR. HIGHEST QPF AMOUNTS WILL BE MAINLY CENTRAL AND EAST AS BEST MID LEVEL FRONTOGENESIS REMAINS ACROSS THE CENTRAL AND EASTERN PORTIONS OF FA...WITH THE HIGHEST QPF POTENTIAL REMAINING ACROSS EASTERN WI AND INTO LOWER MI. PRECIP. SHOULD BE OUT OF THE FA BY THURSDAY AFTN WITH SOME REMNANT RAIN OR SNOW SHOWERS REMAIN OUT EAST. THURSDAY NIGHT THROUGH FRIDAY MORNING LOOKS DRY WITH DRY AIR MOVING IN FROM THE NW. BY 18Z FRI EXPECT SOME RAIN SHOWERS TO MAKE THEIR WAY INTO THE WESTERN FA ASSOCIATED WITH STRONG 850-500MB Q VECTOR CONVERGENCE ALONG WITH DECENT WAA AT 850MB. THIS FEATURE WILL PASS THROUGH BY SATURDAY MORNING...BY WHICH TIME LAKE EFFECT WILL BEGIN OVER THE WESTERN ZONES. .00Z SUNDAY THROUGH WEDNESDAY...STILL SOME DISAGREEMENT WITH THE LOW THAT PASSES TO OUR SE ON SUNDAY. THE LAST FOUR RUNS OF THE GFS HAVE VARIED THE CENTER OF THE LOW AT 12Z ON SUN...WITH THE LATEST(12Z) BRINGING THE CENTER TO NORTHERN INDIANA AND THEN EAST OF LAKE HURON BY 00Z MON...WHILE THE PREVIOUS TWO RUNS KEPT THE LOW OVER CENTRAL OR NORTHERN LOWER MI AT 12Z SUN. PART OF THE VARIABILITY OF THIS SYSTEM SEEMS TO BE RELATED TO RIDGE BUILT UP OVER THE WESTERN CONUS...WITH LATEST TWO RUNS OF THE GFS SHIFTING THIS RIDGE TO WEST...THE SURFACE REFLECTION OF THIS WEEKENDS LOW HAS SHIFTED SOUTH...THIS IS MORE EVIDENT IN THE 06Z RUN THAT THE 12Z. THE LATEST ENSEMBLE MEAN LOOKS SIMILAR TO THE 12Z GFS IN THAT THE LOW BY 00Z MON IS EAST OF LAKE HURON...WHERE IT THEN DEEPENS AS IT MOVES INTO THE CANADIAN MARITIMES BY 00Z THU...THIS WILL KEEP THE FA IN NORTH TO NORTHWESTERLY FLOW THROUGH THE REST OF THE FORECAST PERIOD. THE 00Z(18TH) RUN OF THE ECMWF IS SIMILAR WITH ITS LOCATION OF THE SURFACE LOW AT 00Z MON...THOUGH A BIT FURTHER THE WEST IN ITS LOCATION. A LOW TRACK SOMEWHERE OVER SOUTHERN LAKE HURON SEEMS REASONABLE...ALLOWING LAKE EFFECT PRECIP TO REFORM AFTER A LULL ON SATURDAY. 850 TEMPS OF -6C OR LESS ALONG WITH WINDS OFF LAKE SUPERIOR WILL RETURN SATURDAY AFTERNOON ALLOWING FOR LAKE EFFECT TO REFORM AND PERSIST THROUGH DAY 7...TUESDAY AFTERNOON WINDS WILL BACK TEMPORARILY THEN VEERING AGAIN LATER IN THE NIGHT AS A SHORTWAVE FROM THE NORTH PASSES THROUGH THE EASTERN PART OF THE FA. WHILE THE WEST AND KEWEENAW MAY CONTINUE TO SEE LAKE EFFECT PRECIP. FROM LATE SATURDAY EVENING ON...THE EAST MAY GET A BREAK AS THE WINDS BACK ON TUE. PEARSON && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 830 PM EDT WED OCT 18 2006 .UPDATE...ON THE CURRENT SURFACE WEATHER MAP...997 MB LOW PRESSURE WAS OVER NORTHEAST ONTARIO WITH A COLD FRONT EXTENDING SOUTHWARD ACROSS TO 1008 MB LOW PRESSURE ACROSS SOUTHWEST LOWER MICHIGAN. REGIONAL RADAR IMAGERY SHOWS AREA OF RAIN EXTENDING FROM EASTERN WISCONSIN INTO WESTERN MICHIGAN. GFS SEEMS TO HAVE THE BEST HANDLE OF THE CURRENT SITUATION WITH AREA OF DECENT Q-VECTOR CONVERGENCE MOVING ACROSS THE REGION FROM WEST TO EAST THIS EVENING THROUGH VERY EARLY THURSDAY. THEREFORE...PERIODS OF RAIN (HAVE UPPED POPS TO CATEGORICAL) EXPECTED FOR A FEW HOURS WITH QPF AMOUNTS OF ABOUT A TENTH OF AN INCH NORTH TO AROUND A QUARTER OF AN INCH SOUTHEAST. LATE TONIGHT....RAIN IS EXPECTED TO BECOME MORE SHOWERY AS MID/UPPER LEVEL MOISTURE IS STRIPPED OUT. IN ADDITION...PRECIPITATION WILL BE LAKE DRIVEN AS 850 MB TEMPERATURES DROP TO BETWEEN -4C NORTHWEST AND -1C SOUTHEAST LEADING TO DELTA TS OF AROUND 14 OR SO. LOWS WILL RANGE FROM THE UPPER 30S NORTHWEST TO LOWER 40S SOUTHEAST. UPDATED GRIDS/ZONES ALREADY OUT. SULLIVAN .PREV DISCUSSION...ISSUED 400 PM OCT 18 DISCUSSION...18Z RUC ANALYSIS...AND VIS/IR/WV/RADAR IMAGERY SHOW LOW PRESSURE OVER NORTHERN ONTARIO CONTINUING TO MARCH TOWARDS HUDSON BAY. ITS ASSOCIATED COLD FRONT HAS PROGRESSED SE AND IS NOW LOCATED FROM ABOUT ALPENA TO STANDISH...AND THEN ACROSS CENTRAL SOUTHERN LOWER AND SOUTHERN ILLINOIS. LOOKING AT THE LARGER PICTURE...BROAD RIDGING EXISTS OVER WESTERN NORTH AMERICA AND EASTERN CONUS WHILE A SHARP TROUGH IS LOCATED IN-BETWEEN FROM THE NORTHERN GREAT PLAINS TO THE SOUTHERN ROCKIES. ONE SHORTWAVE IS EXITING OVER NORTHERN ONTARIO...WHILE ANOTHER IS QUICK ON ITS HEALS MOVING NE ACROSS SOUTHERN MINNESOTA. THIS LATTER SHORTWAVE IS EMBEDDED WITHIN THIS TROUGH AND HAS BEEN TRIGGERING SCATTERED SHOWERS AND EVEN A FEW SNOWFLAKES ACROSS NORTHERN IOWA AND SOUTHERN MINNESOTA. ADDITIONAL SHORTWAVES WITHIN THIS TROUGH ANALYZED BY THE RUC HAVE BEEN STEADILY MOVING TO THE NE...AND IS CREATING FGEN FORCING AS IT ENCOUNTERS THE FRONTAL BOUNDARY FURTHER ENHANCING THE PRECIP ACROSS THE MIDWEST. AS THIS VORTICITY SHEAR ZONE AND FGEN FORCING TREK TOWARDS THE CWA...SHOWERS ARE EXPECTED TO DEVELOP THIS EVENING AND TONIGHT...AND WILL BE THE PRIMARY FORECAST CONCERN THROUGH THURSDAY. TONIGHT...THE COLD FRONT WILL CONTINUE TO MOVE SLOWLY SE ACROSS SE LOWER MICHIGAN WHILE EDDIES WITHIN THE VORTICITY SHEAR ZONE TRACK NE AND APPROACH THE CWA BY ABOUT 03Z. AS THIS SHEAR AXIS DRAWS CLOSER TO THE PRE-EXISTING FRONTAL BOUNDARY...IT WILL CREATE WEAK Q-VECTOR CONVERGENCE AND FGEN FORCING WITHIN THE 800-600MB LAYER THAT WILL SPREAD NE ALONG THE FRONT ACROSS NORTHERN LOWER MICHIGAN ACCORDING TO NAM CROSS-SECTIONS. THE BEST FORCING LOOKS TO BE LOCATED SE OF A PRESQUE ISLE TO LAKE CITY LINE AND HAVE THEREFORE INCREASED POPS TO CATEGORICAL IN THIS AREA AND LIKELY ACROSS THE REMAINDER OF NORTHERN LOWER AFTER 00Z. WITH THE BEST FORCING TO THE SOUTH OF EASTERN UPPER...PREFER TO LEAVE WORDING AS A CHANCE HERE. COLDER AIR WILL FILTER IN BEHIND THE FRONT AS IT MOVES TO THE SE...COLD ENOUGH TO THINK ABOUT LAKE EFFECT PROCESSES. 850MB TEMPS COOL TO THE -3C TO -5C RANGE OVER NORTHERN LAKE MICHIGAN AND SOUTHERN LAKE SUPERIOR...CREATING DELTA T'S ABOUT 13-14C OVER EACH LAKE. WITH INVERSION HEIGHTS ABOUT 850MB...MOISTURE WILL STRUGGLE TO REACH MUCH BELOW -5C...SO DO NOT SEE MUCH OF A CHANCE FOR SNOW CRYSTAL PRODUCTION UNLESS AN OVERSHOOTING TOP MANAGES TO BREAK THROUGH THE INVERSION A LITTLE. BUT WILL LEAVE THE SHOWER WORDING AFTER 06Z SINCE WARM RAIN PROCESSES WILL LIKELY OCCUR FROM LAKE EFFECT CONVECTION. MARINE...WEST WINDS WILL BE SHIFTING TO THE NORTHWEST AFTER MIDNIGHT. NAM/GFS SOUNDINGS SHOWING MAX WIND SPEEDS IN THE BOUNDARY LAYER REACHING 20-25 KTS OVER WHITEFISH BAY AND NORTHERN LAKE MICHIGAN. HAVE THOUGHT ABOUT ISSUING SMALL CRAFT ADVISORIES FOR WHITEFISH BAY WITH THE LONG FETCH COMING INTO PLAY. A SMALL WINDOW FOR BORDERLINE SMALL CRAFT ADVISORY CONDITIONS MAY BE POSSIBLE LATE TONIGHT...BUT WITH DECREASING WINDS TOMORROW...HAVE DECIDED AGAINST POSTING ANY HEADLINES AT THIS TIME AND WILL DEFER TO LATER SHIFTS. MPC LATER PERIODS...WILL HAVE SOME WEAK LAKE EFFECT ACTIVITY TO CONTEND WITH EARLY ON THURSDAY...THEN THE FOCUS SHIFTS TOWARDS THE END OF THE WEEKEND AND EARLY NEXT WEEK...WITH A STORM SYSTEM PASSING THROUGH THE GREAT LAKES REGION...DRAGGING ARCTIC AIR SOUTHWARD ACROSS THE REGION. THIS WILL SET THE STAGE FOR MORE ACCUMULATING SNOWFALL EARLY NEXT WEEK. MODELS ARE IN MUCH BETTER AGREEMENT THROUGH THE UPCOMING WEEKEND...SO WILL HEDGE TOWARDS MORE OF A BLEND. THURSDAY...MAIN SYNOPTIC SYSTEM PULLS OUT BEFORE 12Z THURSDAY... LEAVING CAA IN ITS WAKE. 850-700MB RH DECREASES TO AROUND 65% BY MIDDAY...THEN LESS THAN 40% BY EVENING. AT THE SAME TIME...850MB TEMPS WILL DROP TO AROUND -4C ACROSS THE ENTIRE AREA CREATING OVER LAKE INSTABILITY. HOWEVER...MOISTURE WILL NOT EXTEND BEYOND THE -5C ISOTHERM...WHICH WOULD NOT BE FAVORABLE FOR ICE CRYSTAL ACTIVATION. THIS MAY BE A SCENARIO FOR LAKE EFFECT DRIZZLE OR VERY LIGHT RAIN SHOWERS IN THE FAVORED NORTHWEST FLOW AREAS. WOULD GO PURELY WITH DRIZZLE...BUT WITH SUCH WARM LAKE TEMPERATURES...SOME CONVECTIVE ELEMENTS IN THE PRECIPITATION ARE CERTAINLY POSSIBLE. THIS ACTIVITY WILL DIMINISH BY AFTERNOON AS DRY AIR AND BACKING WINDS END THE THREAT. OTHERWISE...WITH CLOUDS HANGING AROUND FOR MOST OF THE DAY...TEMPERATURES WILL ONLY GET INTO THE MIDDLE TO UPPER 40S FOR HIGHS. THURSDAY NIGHT AND FRIDAY...WITH SURFACE RIDGING OVER THE AREA...EXPECT THE QUIETEST WEATHER FOR THE WEEK DURING THIS TIME PERIOD. STILL EXPECT SOME CLOUDINESS...WITH 850MB TEMPS REMAINING BELOW 0C...BUT WITH WEAK WINDS...THESE CLOUDS WILL REMAIN CONFINED TO THE COAST...WITH MORE BREAKS IN THE CLOUDS INLAND. WITH LIGHT WINDS AND LESS CLOUD COVER...TEMPERATURES WILL FALL INTO THE UPPER 20S TO LOWER 30S THURSDAY NIGHT...THEN RECOVER BACK INTO THE MID TO UPPER 40S ON FRIDAY. FRIDAY NIGHT...SURFACE RIDGING SLIDES EAST. MODELS ARE NOW IN BETTER AGREEMENT ON A SHORTWAVE PASSING THROUGH THE UPPER PENINSULA AND THE TIP OF THE MIT FRIDAY NIGHT. THE LATEST GFS RUN HAS ALSO PICKED UP ON THIS FEATURE. ALTHOUGH MOISTURE DOES INCREASE IN A RATHER DEEP COLUMN...IT NEVER FULLY MOISTENS UP FROM TOP TO BOTTOM. INITIALLY... DRY AIR FROM THE SFC TO AROUND 5KFT WILL HELP EVAPORATE PRECIP BEFORE REACHING THE GROUND. TOWARDS SATURDAY MORNING...THE LOWER LEVELS WILL BEGIN TO MOISTEN UP...BUT DRY AIR ALOFT BEGINS TO OVERSPREAD THE AREA...WHICH WOULD BE A GOOD SCENARIO FOR DRIZZLE EARLY SATURDAY MORNING. SPRINKLES WOULD PROBABLY BE THE BEST BEST EARLY FRIDAY NIGHT WITH A FEW RAINDROPS REACHING THE SURFACE. WITH AGREEMENT IN MODELS...WILL INTRODUCE A CHANCE OF LIGHT RAIN SHOWERS LATE FRIDAY NIGHT...INTO SATURDAY MORNING. WITH A RATHER SHALLOW WARM LAYER...WILL ALSO HAVE TO WATCH THE POTENTIAL OF SOME SNOWFLAKES EARLY FRIDAY NIGHT...BUT NOT ENOUGH CONFIDENCE TO GO THIS FAR AT THIS TIME. WITH CLOUDS FILLING IN OVERNIGHT...LOWS WILL REMAIN HIGHER GENERALLY IN THE MIDDLE TO UPPER 30S. SATURDAY THROUGH TUESDAY...ECMWF AND GFS ARE IN GREAT AGREEMENT WITH RESPECT TO SYSTEM DEVELOPING AND PASSING OUT OF THE CENTRAL PLAINS AND ACROSS CENTRAL LOWER MICHIGAN SATURDAY NIGHT AND SUNDAY. THE 84HR NAM PUTS THE SURFACE LOW MUCH FURTHER SOUTH THAN THE GFS/ECMWF SOLUTION AND CONSIDERING IT HAS BEEN THE OUTLIER OVER THE PAST SEVERAL DAYS...WILL CONTINUE TO SHY AWAY FROM THE NAM. BROAD UPPER LEVEL LOW PATTERN CURRENTLY IN PLACE WILL GIVE WAY TO A MORE AMPLIFIED TROUGH BY EARLY NEXT WEEK WITH THE INFLUENCE OF SHORTWAVE MOVING OUT OF THE PACIFIC NORTHWEST AND INTO THE EASTERN PART OF THE US. ARCTIC AIR WILL WRAP AROUND THE DEPARTING STORM SYSTEM EARLY NEXT WEEK...WITH 850MB TEMPERATURES DROPPING TO -6C BY 12Z ON MONDAY. WILL KEEP HIGH CHANCE POPS AS SYSTEM MOVES OUT OF NORTHERN ILLINOIS AND INTO CENTRAL LOWER MICHIGAN SATURDAY NIGHT AND SUNDAY. SYSTEM DEPARTS SUNDAY NIGHT...WITH A TRANSITION TO LAKE EFFECT PRECIPITATION. PRECIPITATION WILL START OFF AS MAINLY RAIN SATURDAY NIGHT AND SUNDAY...BUT WILL BEGIN TO CHANGE OVER TO SNOW IN EASTERN UPPER AND IN THE HIGHER TERRAIN OF NORTHERN LOWER BY LATE AFTERNOON. WILL BUMP POPS UP TO LIKELY SATURDAY NIGHT AND EARLY SUNDAY AS -DIVQ OVERSPREADS NORTHERN MICHIGAN WITH DEEP MOISTURE. SYSTEM EXITS BY SUNDAY AFTERNOON...BUT WILL KEEP CHANCE POPS AROUND FOR LINGERING PRECIPITATION. LAKE EFFECT KICKS IN SUNDAY NIGHT WITH A TRANSITION TO ALL SNOW...EXCEPT A MIX NEAR THE LAKES TAKING PLACE. LAKE EFFECT SNOW SHOWERS WILL THEN CONTINUE THROUGH TUESDAY. GFS EVEN HAS A SHORTWAVE PASSING THROUGH ON TUESDAY...PERHAPS LEADING TO SOME LAKE ENHANCED SNOWFALL. PATTERN IN GENERAL LOOKS MUCH MORE WINTRY EARLY NEXT WEEK. HIGHS SATURDAY WILL TOP OUT IN THE MIDDLE 40S WITH FALLING TEMPERATURES FOR SUNDAY. EVENTUALLY...BY MONDAY AND TUESDAY...SOME PLACES WILL BE LUCKY TO GET ABOVE THE MIDDLE 30S FOR DAYTIME HIGHS. MEX GUIDANCE SUGGEST MID 40S FOR NEXT WEEK...BUT ARE BEING INFLUENCED WAY TOO MUCH BY CLIMATOLOGY WITH NORMAL DAYTIME HIGHS IN THE LOWER TO MIDDLE 50S. KAS && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 400 PM EDT WED OCT 18 2006 .DISCUSSION...18Z RUC ANALYSIS...AND VIS/IR/WV/RADAR IMAGERY SHOW LOW PRESSURE OVER NORTHERN ONTARIO CONTINUING TO MARCH TOWARDS HUDSON BAY. ITS ASSOCIATED COLD FRONT HAS PROGRESSED SE AND IS NOW LOCATED FROM ABOUT ALPENA TO STANDISH...AND THEN ACROSS CENTRAL SOUTHERN LOWER AND SOUTHERN ILLINOIS. LOOKING AT THE LARGER PICTURE...BROAD RIDGING EXISTS OVER WESTERN NORTH AMERICA AND EASTERN CONUS WHILE A SHARP TROUGH IS LOCATED IN-BETWEEN FROM THE NORTHERN GREAT PLAINS TO THE SOUTHERN ROCKIES. ONE SHORTWAVE IS EXITING OVER NORTHERN ONTARIO...WHILE ANOTHER IS QUICK ON ITS HEALS MOVING NE ACROSS SOUTHERN MINNESOTA. THIS LATTER SHORTWAVE IS EMBEDDED WITHIN THIS TROUGH AND HAS BEEN TRIGGERING SCATTERED SHOWERS AND EVEN A FEW SNOWFLAKES ACROSS NORTHERN IOWA AND SOUTHERN MINNESOTA. ADDITIONAL SHORTWAVES WITHIN THIS TROUGH ANALYZED BY THE RUC HAVE BEEN STEADILY MOVING TO THE NE...AND IS CREATING FGEN FORCING AS IT ENCOUNTERS THE FRONTAL BOUNDARY FURTHER ENHANCING THE PRECIP ACROSS THE MIDWEST. AS THIS VORTICITY SHEAR ZONE AND FGEN FORCING TREK TOWARDS THE CWA...SHOWERS ARE EXPECTED TO DEVELOP THIS EVENING AND TONIGHT...AND WILL BE THE PRIMARY FORECAST CONCERN THROUGH THURSDAY. TONIGHT...THE COLD FRONT WILL CONTINUE TO MOVE SLOWLY SE ACROSS SE LOWER MICHIGAN WHILE EDDIES WITHIN THE VORTICITY SHEAR ZONE TRACK NE AND APPROACH THE CWA BY ABOUT 03Z. AS THIS SHEAR AXIS DRAWS CLOSER TO THE PRE-EXISTING FRONTAL BOUNDARY...IT WILL CREATE WEAK Q-VECTOR CONVERGENCE AND FGEN FORCING WITHIN THE 800-600MB LAYER THAT WILL SPREAD NE ALONG THE FRONT ACROSS NORTHERN LOWER MICHIGAN ACCORDING TO NAM CROSS-SECTIONS. THE BEST FORCING LOOKS TO BE LOCATED SE OF A PRESQUE ISLE TO LAKE CITY LINE AND HAVE THEREFORE INCREASED POPS TO CATEGORICAL IN THIS AREA AND LIKELY ACROSS THE REMAINDER OF NORTHERN LOWER AFTER 00Z. WITH THE BEST FORCING TO THE SOUTH OF EASTERN UPPER...PREFER TO LEAVE WORDING AS A CHANCE HERE. COLDER AIR WILL FILTER IN BEHIND THE FRONT AS IT MOVES TO THE SE...COLD ENOUGH TO THINK ABOUT LAKE EFFECT PROCESSES. 850MB TEMPS COOL TO THE -3C TO -5C RANGE OVER NORTHERN LAKE MICHIGAN AND SOUTHERN LAKE SUPERIOR...CREATING DELTA T'S ABOUT 13-14C OVER EACH LAKE. WITH INVERSION HEIGHTS ABOUT 850MB...MOISTURE WILL STRUGGLE TO REACH MUCH BELOW -5C...SO DO NOT SEE MUCH OF A CHANCE FOR SNOW CRYSTAL PRODUCTION UNLESS AN OVERSHOOTING TOP MANAGES TO BREAK THROUGH THE INVERSION A LITTLE. BUT WILL LEAVE THE SHOWER WORDING AFTER 06Z SINCE WARM RAIN PROCESSES WILL LIKELY OCCUR FROM LAKE EFFECT CONVECTION. MARINE...WEST WINDS WILL BE SHIFTING TO THE NORTHWEST AFTER MIDNIGHT. NAM/GFS SOUNDINGS SHOWING MAX WIND SPEEDS IN THE BOUNDARY LAYER REACHING 20-25 KTS OVER WHITEFISH BAY AND NORTHERN LAKE MICHIGAN. HAVE THOUGHT ABOUT ISSUING SMALL CRAFT ADVISORIES FOR WHITEFISH BAY WITH THE LONG FETCH COMING INTO PLAY. A SMALL WINDOW FOR BORDERLINE SMALL CRAFT ADVISORY CONDITIONS MAY BE POSSIBLE LATE TONIGHT...BUT WITH DECREASING WINDS TOMORROW...HAVE DECIDED AGAINST POSTING ANY HEADLINES AT THIS TIME AND WILL DEFER TO LATER SHIFTS. MPC LATER PERIODS...WILL HAVE SOME WEAK LAKE EFFECT ACTIVITY TO CONTEND WITH EARLY ON THURSDAY...THEN THE FOCUS SHIFTS TOWARDS THE END OF THE WEEKEND AND EARLY NEXT WEEK...WITH A STORM SYSTEM PASSING THROUGH THE GREAT LAKES REGION...DRAGGING ARCTIC AIR SOUTHWARD ACROSS THE REGION. THIS WILL SET THE STAGE FOR MORE ACCUMULATING SNOWFALL EARLY NEXT WEEK. MODELS ARE IN MUCH BETTER AGREEMENT THROUGH THE UPCOMING WEEKEND...SO WILL HEDGE TOWARDS MORE OF A BLEND. THURSDAY...MAIN SYNOPTIC SYSTEM PULLS OUT BEFORE 12Z THURSDAY... LEAVING CAA IN ITS WAKE. 850-700MB RH DECREASES TO AROUND 65% BY MIDDAY...THEN LESS THAN 40% BY EVENING. AT THE SAME TIME...850MB TEMPS WILL DROP TO AROUND -4C ACROSS THE ENTIRE AREA CREATING OVER LAKE INSTABILITY. HOWEVER...MOISTURE WILL NOT EXTEND BEYOND THE -5C ISOTHERM...WHICH WOULD NOT BE FAVORABLE FOR ICE CRYSTAL ACTIVATION. THIS MAY BE A SCENARIO FOR LAKE EFFECT DRIZZLE OR VERY LIGHT RAIN SHOWERS IN THE FAVORED NORTHWEST FLOW AREAS. WOULD GO PURELY WITH DRIZZLE...BUT WITH SUCH WARM LAKE TEMPERATURES...SOME CONVECTIVE ELEMENTS IN THE PRECIPITATION ARE CERTAINLY POSSIBLE. THIS ACTIVITY WILL DIMINISH BY AFTERNOON AS DRY AIR AND BACKING WINDS END THE THREAT. OTHERWISE...WITH CLOUDS HANGING AROUND FOR MOST OF THE DAY...TEMPERATURES WILL ONLY GET INTO THE MIDDLE TO UPPER 40S FOR HIGHS. THURSDAY NIGHT AND FRIDAY...WITH SURFACE RIDGING OVER THE AREA...EXPECT THE QUIETEST WEATHER FOR THE WEEK DURING THIS TIME PERIOD. STILL EXPECT SOME CLOUDINESS...WITH 850MB TEMPS REMAINING BELOW 0C...BUT WITH WEAK WINDS...THESE CLOUDS WILL REMAIN CONFINED TO THE COAST...WITH MORE BREAKS IN THE CLOUDS INLAND. WITH LIGHT WINDS AND LESS CLOUD COVER...TEMPERATURES WILL FALL INTO THE UPPER 20S TO LOWER 30S THURSDAY NIGHT...THEN RECOVER BACK INTO THE MID TO UPPER 40S ON FRIDAY. FRIDAY NIGHT...SURFACE RIDGING SLIDES EAST. MODELS ARE NOW IN BETTER AGREEMENT ON A SHORTWAVE PASSING THROUGH THE UPPER PENINSULA AND THE TIP OF THE MIT FRIDAY NIGHT. THE LATEST GFS RUN HAS ALSO PICKED UP ON THIS FEATURE. ALTHOUGH MOISTURE DOES INCREASE IN A RATHER DEEP COLUMN...IT NEVER FULLY MOISTENS UP FROM TOP TO BOTTOM. INITIALLY... DRY AIR FROM THE SFC TO AROUND 5KFT WILL HELP EVAPORATE PRECIP BEFORE REACHING THE GROUND. TOWARDS SATURDAY MORNING...THE LOWER LEVELS WILL BEGIN TO MOISTEN UP...BUT DRY AIR ALOFT BEGINS TO OVERSPREAD THE AREA...WHICH WOULD BE A GOOD SCENARIO FOR DRIZZLE EARLY SATURDAY MORNING. SPRINKLES WOULD PROBABLY BE THE BEST BEST EARLY FRIDAY NIGHT WITH A FEW RAINDROPS REACHING THE SURFACE. WITH AGREEMENT IN MODELS...WILL INTRODUCE A CHANCE OF LIGHT RAIN SHOWERS LATE FRIDAY NIGHT...INTO SATURDAY MORNING. WITH A RATHER SHALLOW WARM LAYER...WILL ALSO HAVE TO WATCH THE POTENTIAL OF SOME SNOWFLAKES EARLY FRIDAY NIGHT...BUT NOT ENOUGH CONFIDENCE TO GO THIS FAR AT THIS TIME. WITH CLOUDS FILLING IN OVERNIGHT...LOWS WILL REMAIN HIGHER GENERALLY IN THE MIDDLE TO UPPER 30S. SATURDAY THROUGH TUESDAY...ECMWF AND GFS ARE IN GREAT AGREEMENT WITH RESPECT TO SYSTEM DEVELOPING AND PASSING OUT OF THE CENTRAL PLAINS AND ACROSS CENTRAL LOWER MICHIGAN SATURDAY NIGHT AND SUNDAY. THE 84HR NAM PUTS THE SURFACE LOW MUCH FURTHER SOUTH THAN THE GFS/ECMWF SOLUTION AND CONSIDERING IT HAS BEEN THE OUTLIER OVER THE PAST SEVERAL DAYS...WILL CONTINUE TO SHY AWAY FROM THE NAM. BROAD UPPER LEVEL LOW PATTERN CURRENTLY IN PLACE WILL GIVE WAY TO A MORE AMPLIFIED TROUGH BY EARLY NEXT WEEK WITH THE INFLUENCE OF SHORTWAVE MOVING OUT OF THE PACIFIC NORTHWEST AND INTO THE EASTERN PART OF THE US. ARCTIC AIR WILL WRAP AROUND THE DEPARTING STORM SYSTEM EARLY NEXT WEEK...WITH 850MB TEMPERATURES DROPPING TO -6C BY 12Z ON MONDAY. WILL KEEP HIGH CHANCE POPS AS SYSTEM MOVES OUT OF NORTHERN ILLINOIS AND INTO CENTRAL LOWER MICHIGAN SATURDAY NIGHT AND SUNDAY. SYSTEM DEPARTS SUNDAY NIGHT...WITH A TRANSITION TO LAKE EFFECT PRECIPITATION. PRECIPITATION WILL START OFF AS MAINLY RAIN SATURDAY NIGHT AND SUNDAY...BUT WILL BEGIN TO CHANGE OVER TO SNOW IN EASTERN UPPER AND IN THE HIGHER TERRAIN OF NORTHERN LOWER BY LATE AFTERNOON. WILL BUMP POPS UP TO LIKELY SATURDAY NIGHT AND EARLY SUNDAY AS -DIVQ OVERSPREADS NORTHERN MICHIGAN WITH DEEP MOISTURE. SYSTEM EXITS BY SUNDAY AFTERNOON...BUT WILL KEEP CHANCE POPS AROUND FOR LINGERING PRECIPITATION. LAKE EFFECT KICKS IN SUNDAY NIGHT WITH A TRANSITION TO ALL SNOW...EXCEPT A MIX NEAR THE LAKES TAKING PLACE. LAKE EFFECT SNOW SHOWERS WILL THEN CONTINUE THROUGH TUESDAY. GFS EVEN HAS A SHORTWAVE PASSING THROUGH ON TUESDAY...PERHAPS LEADING TO SOME LAKE ENHANCED SNOWFALL. PATTERN IN GENERAL LOOKS MUCH MORE WINTRY EARLY NEXT WEEK. HIGHS SATURDAY WILL TOP OUT IN THE MIDDLE 40S WITH FALLING TEMPERATURES FOR SUNDAY. EVENTUALLY...BY MONDAY AND TUESDAY...SOME PLACES WILL BE LUCKY TO GET ABOVE THE MIDDLE 30S FOR DAYTIME HIGHS. MEX GUIDANCE SUGGEST MID 40S FOR NEXT WEEK...BUT ARE BEING INFLUENCED WAY TOO MUCH BY CLIMATOLOGY WITH NORMAL DAYTIME HIGHS IN THE LOWER TO MIDDLE 50S. KAS && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 239 PM CDT WED OCT 18 2006 .DISCUSSION... NEAR TERM...TONIGHT THROUGH THURSDAY MIX OF RAIN AND SNOW CONTINUES ACROSS MUCH OF THE FORECAST AREA...IN AN AREA OF WEAK ISENTROPIC LIFT AND LOW CONDENSATION PRESSURE DEFICITS /285K SURFACE/ AHEAD OF A POTENT SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND INTO WESTERN WISCONSIN THIS AFTERNOON. INTENSITY OF THE ECHOES HAS GENERALLY DECREASED OVER THE PAST FEW HOURS AS EVIDENCED BY DECREASING REFLECTIVITIES AND RISING VISIBILITIES ON THE SURFACE OBSERVATIONS...AND THIS IS WELL DEPICTED IN THE WEAKENING LIFT AND INCREASING CONDENSATION PRESSURE DEFICITS ON THE RUC 285K ANALYSIS. THE EXPECTATION IS THAT THE REMAINING PRECIPITATION WILL BE WELL EAST OF THE FORECAST AREA BY 00Z TONIGHT SO HAVE CONTINUED THE PREVIOUS FORECAST OF DRY WEATHER PAST THE TODAY PERIOD. THE NEXT QUESTION TURNS TO HOW QUICKLY THE CLOUD COVER WILL DISSIPATE AND ITS RESULTANT EFFECT ON OVERNIGHT TEMPERATURES. HAVE ALREADY SLOWED THE INHERITED DEPARTURE OF THE CLOUD COVER BY SEVERAL HOURS IN PREVIOUS FORECAST UPDATES...AND CURRENT AVIATION FORECASTS EXHIBIT THE SAME SLOWER TREND. AS A RESULT...HAVE INCREASED MIN TEMPERATURES TONIGHT ACROSS THE SOUTHEASTERN THIRD TO HALF OF THE FORECAST AREA...WITH SKIES EXPECTED TO REMAIN /AT THE VERY LEAST/ MOSTLY CLOUDY UNTIL MORNING. WESTERN MINNESOTA SHOULD BREAK OUT OF THE CLOUDS NEAR MIDNIGHT SO KEPT THE MID 20S IN THIS AREA...ESPECIALLY WITH THE SURFACE HIGH SLIDING IN. THE NEXT SYSTEM APPROACHES WESTERN MINNESOTA LATE THURSDAY AFTERNOON...WITH 12Z NAM AND GFS ISENTROPIC ANALYSES SHOWING A WEAK AREA OF LIFT AND REDUCED CONDENSATION PRESSURE DEFICITS MOVING INTO WESTERN MINNESOTA DURING THE MID TO LATE AFTERNOON TOMORROW...IN A REGION OF WARM ADVECTION. ALSO RAISED MAX TEMPERATURES SOMEWHAT IN THE SOUTHWEST FORECAST AREA WITH REDUCED CLOUDS AND A NOSE OF 2 TO 4C 850 MB AIR PUSHING INTO THIS REGION. LONGER TERM...FRIDAY THROUGH WEDNESDAY PATTERN OF TROF OVER THE GREAT LAKES AND ERN U.S. WILL BE IN PLACE AT THE START OF THE PERIOD. CURRENTLY...UPPER RIDGE CONTINUES TO BE IN PLACE OVER THE EASTERN PACIFIC WITH LONG WAVE TROF EXTENDING FROM POLAR VORTEX OVER THE CANADIAN ARCTIC INTO THE DESERT SOUTHWEST. NEXT SYSTEM TO AFFECT THE AREA IS NOW SPINNING OVER SOUTHERN ALASKA AND IS THE REMNANTS OF TYPHOON/TROPICAL STORM SOULIK. IN THE NEAR TERM...WEAK SFC LOW AND AND UPPER TROF MOVE EASTWARD ACROSS NORTH DAKOTA AND NORTHERN MINNESOTA. UPPER FORCING WILL BE CLOSE ENOUGH TO THE AREA TO WARRANT SLIGHT POPS ACROSS THE FAR NORTHERN CWA THURSDAY NIGHT AND EARLY FRIDAY MORNING. HAVE RAIN OR SNOW GOING DURING THE OVERNIGHT AND WITH GOOD COLD AIR ALOFT...LOW LEVELS WILL LIKELY BE TOO WARM DURING DAYLIGHT HOURS TO SUPPORT ANY FROZEN PRECIP. HAVE THUS TRANSITIONED TO RAIN SHOWERS FRIDAY MORNING. NEXT EVENT FOR THE CWA WILL COME LATE FRIDAY EVENING INTO SATURDAY MORNING AS STRONG UPPER SHORTWAVE AND ASSOCIATED SFC LOW DROP ACROSS THE HIGH PLAINS AND SFC LOW INTENSIFIES OVER THE TEXAS AND OKLAHOMA PANHANDLES...WITH INVERTED TROF EXTENDING NORTHEAST INTO THE MID MISSISSIPPI RIVER VALLEY. THERE ARE SOME DISCREPANCIES AMONG THE MODELS WITH THE EVOLUTION OF THIS SYSTEM. BEST FORCING EXPECTED TO STAY SOUTH OF THE AREA WITH BAROCLINIC ZONE TIGHTENING OVER IA/IL/ERN WI. UPPER LEVEL QG FORCING AND MOISTURE WILL BE PRESENT LOCALLY...ESPECIALLY ACROSS THE SOUTHERN CWA...WITH PASSAGE OF BASE OF UPPER LOW. HAVE GONE PRIMARILY RAIN/SNOW MIX AFTER INITIAL ALL RAIN ONSET. WILL HAVE TO KEEP AN EYE ON THIS AS THE SYSTEM DRAWS CLOSER...BUT IT LOOKS AS THOUGH LOW LEVELS WILL REMAIN TOO WARM TO SUPPORT ALL FROZEN PRECIP. COLDEST LOW LEVEL AIR DOESN/T APPEAR TO BUILD IN UNTIL MOISTURE IS OFF TO THE EAST. ECMWF AND CANADIAN GEM ARE IN GOOD AGREEMENT THROUGH THE OUTER PERIODS. PATTERN EVOLVES FROM A TROF OVER THE GREAT LAKES TO WEST TO EAST ZONAL FLOW BY EARLY NEXT WEEK. THIS IS SUPPORTED BY THE TELECONNECTION RELATING TYPHOON RE-CURVATURE TO UPPER FLOW PATTERN OVER THE ERN U.S. SOULIK WAS CAUGHT UP IN THE MID LATITUDE WESTERLIES THIS PAST SATURDAY AND ACCORDING TO THE TELECONNECTION A TROF OVER THE ERN U.S. CAN BE EXPECTED 7 TO 10 DAYS AFTER THIS OCCURS. THIS SUPPORTS SHIFT OF TROFFING FROM THE CENTRAL AND WESTERN U.S. TO THE EAST. 06Z GFS WAS KEEPING THE TROF ACROSS THE CENTRAL U.S. 12Z VERSION IS MORE CONSISTENT WITH CANADIAN AND ECMWF INITIALLY...BUT DEPARTURE OF TROF IS MUCH SLOWER WHILE UPSTREAM PATTERN OF RIDGE OVER THE CANADIAN ROCKIES AND DEEP CUTOFF TROF OVER THE ERN PACIFIC IS MORE AMPLIFIED THAN OTHER MODELS. DO EXPECT MODERATING TEMPERATURES EARLY NEXT WEEK AS TROF MOVES OUT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ KAT/MDB mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 854 PM CDT WED OCT 18 2006 .UPDATE... CHALLENGE TONIGHT WAS CLOUD COVER AND CORRESPONDING TEMPERATURE CHANGES. LOWER CLOUDS MOVING OUT AND HIGHER CLOUDS MOVING IN FROM THE WEST WILL KEEP US CLOUDY MOST OF THE NIGHT ... EXCEPT FOR A SHORT CLEARING BETWEEN SYSTEMS AS THE INCOMING CLOUDS ARE MOVING FASTER THAN THE OUTGOING. KEPT INHERITED MIN TEMPERATURES LOW IN CASE WE CLEAR OUT LONGER THAN EXPECTED. MODELS HANDLED THE TIMING OF THE MOVEMENT DIFFERENTLY. CONSULTED UPPER AIR RELATIVE HUMIDITY VALUES AND CHOSE GFS FOR THE INCOMING CLOUDS AND RUC FOR THE OUTGOING. && .PREV DISCUSSION... (ISSUED 232 PM CDT WED OCT 18 2006) SHORT TERM... SFC RIDGE CONTINUES TO MOVE EAST INTO THE REGION...ALONG WITH CLEARING LINE MOVING INTO CENTRAL ND. MODELS ARE IN VERY GOOD AGREEMENT WITH OVERALL FEATURES AND EVEN MOST FORECAST DETAILS THROUGH SATURDAY. THE GFS HAS CONTINUED TO PERFORM WELL LATELY...AND THE NAM/WRF HAS TRENDED FURTHER SOUTH WITH FRI/SAT SYSTEM AND NOW MATCHES THE GFS. THEREFORE...WILL SIDE WITH THE GFS FOR THIS PACKAGE. FOR TONIGHT...CLEARING ASSOCIATED WITH RIDGE AND SUBSIDENCE WILL MOVE FROM WEST TO EAST. EXPECT TEMPS TO DROP FAIRLY QUICKLY THIS EVENING WITH LIGHT WINDS. THROUGHOUT THE NIGHT THOUGH...WARM ADVECTION ALOFT ALONG WITH INCREASING HIGH CLOUDS AFTER MIDNIGHT SHOULD MEAN TEMPS STEADY LATER TONIGHT. OVERNIGHT LOWS WILL STILL FALL INTO THE MID 20S...AND MAYBE EVEN A BIT COOLER IN EASTERN AREAS WHERE WINDS WILL STAY LIGHT MOST OF THE NIGHT. FOG SHOULDN/T BE A PROBLEM WITH SOME MIXING IN RETURN FLOW LATE AND CLOUDS MOVING IN...BUT EVENING SHIFT WILL NEED TO MONITOR MAINLY EASTERN AREAS CLOSER TO RIDGE AXIS LATER TONIGHT. FOR THU/THU NIGHT...PROGRESSIVE FLOW WILL CONTINUE AND NEXT SHORTWAVE WILL MOVE INTO THE AREA BY AFTERNOON. SOUNDINGS INDICATE ENOUGH SATURATION SHOULD OCCUR BY LATE AFTERNOON FOR AT LEAST A CHANCE FOR SOME SHOWERS. IN ADDITION...LARGE SCALE LIFT PER 500-300MB Q VECTOR CONVERGENCE FIELDS AND FAIRLY DEEP OMEGA SHOULD HELP GENERATE AT LEAST A FEW SHOWERS. SOUNDINGS SUPPORT MAINLY RAIN INTO THE EVENING...BUT A MIX WITH SNOW AFTER 00Z FRI IS POSSIBLE AND WILL MENTION. ON FRI/SAT...COLD HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE AREA FROM THE NORTH AT THE SFC. THIS WILL RESULT IN TEMPERATURES WELL BELOW NORMAL AND STORM TRACK SUPPRESSED WELL TO THE SOUTH IN SOUTHERN STREAM. SYSTEM THAT WAS SUPPOSED TO BRUSH US NOW LOOKS TO MOVE SOUTH OF THE FORECAST AREA...AND HAVE REMOVED CHANCES FOR PRECIP. THERE COULD BE A FEW FLURRIES BOTH FRI AND SAT...BUT FOR NOW WON/T MENTION WITH VERY LIMITED MOISTURE THROUGH COLUMN. LONG TERM (SUN-WED)...500 MB SHORT WAVE PROGGED TO DIVE INTO THE CENTRAL PLAINS OVER THE WEEKEND WILL SET UP A LARGE UPPER LOW OVER THE GREAT LAKES AND ONTARIO MON-WED TIME FRAME. AREA WILL BE IN NORTHWEST FLOW ON BACKSIDE OF LOW WITH RESULTANT CLOUDS MONDAY SLOWLY GIVING WAY TO A BIT MORE SUN AS LOW MOVES EAST TUE-WED. COOLEST DAY ON MONDAY...THEN SLOW MODERATION TUE-WED...BUT STILL BELOW NORMAL. NO SIGNIFICANT CHANCES OF PCPN. AVIATION... PROBLEM IS TIMING OF CLEARING OF THE WIDESPREAD VFR-MVFR CEILINGS. CLEARING IS WORKING THRU WRN ND AT 18Z...AND EXTRAPOLATION EAST AT NR 20 KTS WOULD BRING CLEARING INTO THE GFK-FAR AREAS 01-03Z AND BEMIDJI MORE TOWARD 06Z. THESE AREA APPROX TIMES. LIGHT FLOW AT THE SFC DEVELOPING TONIGHT COULD POSSIBLY RESULT IN INVERSION AND CLOUDS HOLDING ON THOUGH. HIGH CLOUDS WILL MOVE IN BY 12Z THU AHEAD OF NEXT SYSTEM. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ STEINBRUCKNER/GODON nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1006 AM CDT WED OCT 18 2006 STRONG LOW LEVEL FRONTOGENESIS...THE ASSOCIATED INVERSION...AND AMPLE LOWER LEVEL MOISTURE HAVE RESULTED IN A LARGE REGION OF THICK STRATUS NORTH OF THE COLD FRONT...WITH THE LEADING EDGE OF CLOUDS NEARLY COLOCATED WITH THE FRONT. THE FRONT CONTINUES TO MOVE QUICKLY THROUGH SOUTHEAST OKLAHOMA THIS MORNING WITH DEEPER MOISTURE OVER TEXAS ADVECTING AHEAD OF IT. CLOUDS MAY BE IN FOR THE DURATION DUE TO THESE CONDITIONS WITH TEMPERATURES FALLING SLOWLY OR LEVELING OFF DURING THE DAY. RELATIVE POSITION AND SPEED OF THE ASSOCIATED LONGWAVE TROUGH SUGGEST INCREASING AND DEEPENING ASCENT ACROSS MUCH OF THE REGION TONIGHT/EARLY THURSDAY WITH BEST CHANCES OF IT RESULTING IN SHOWERS/STORMS ACROSS SOUTHEAST OKLAHOMA WHERE MOISTURE WILL BE MOST ABUNDANT. LOW CHANCES OF THUNDERSTORMS CONTINUE ACROSS SOUTHEAST OKLAHOMA THIS AFTERNOON BUT CHANCES APPEAR QUITE SLIM BEFORE EVENING. AWAY FROM SOUTHEAST OKLAHOMA...PATCHES OF LIGHT RAIN/DRIZZLE MAY DEVELOP TONIGHT/EARLY THURSDAY. JAMES ------------------------- 321 AM CDT WED OCT 18 2006 .DISCUSSION... CLOUDS AND COLD FRONT MAKING GOOD PROGRESS SOUTH EARLY THIS MORNING...ESPECIALLY OVER THE HIGHER TERRAIN. APPEARS LATEST RUC HAS DECENT HANDLE ON FRONTAL POSITION AND CLOUDS SO WILL FOLLOWING OUTPUT CLOSELY THROUGH 18Z. HAVE RAISED POPS FOR THIS EVENING ACROSS FAR SOUTHEAST COUNTIES AS GFS/NAM SIMILAR IN DEVELOPING RAIN/TSRA NORTHWEST OF SURFACE FRONT AS UPPER TROUGH APPROACHES. AS FRONTAL ZONE DEEPENS WILL LIKELY SEE CLOUD COVER TRANSITION FROM LOWER CLOUDS TO MID LEVEL ACROSS NORTHERN AND CENTRAL PARTS OF FA. STILL EXPECT FORCING ASSOCIATED WITH UPPER TROUGH TO SQUEEZE OUT SOME PRECIP ACROSS WESTERN AND CENTRAL OKLAHOMA LATE TONIGHT INTO FIRST PART OF THURSDAY. WILL SEE CLOUDS ERODE FROM WEST TO EAST THURSDAY WITH SOME REBOUND IN TEMPS...ESPECIALLY WEST AND SOUTHWEST. WARMER TEMPS STILL LOOK GOOD FOR FRIDAY BEFORE NEXT FRONTAL PASSAGE EARLY SATURDAY. SLIGHT POPS STILL LOOK OK FOR SATURDAY...WITH BELOW NORMAL TEMPS EXPECTED OVER THE WEEKEND INTO EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 62 40 62 42 / 10 30 20 0 HOBART OK 61 39 64 42 / 10 30 20 0 WICHITA FALLS TX 69 44 65 42 / 10 40 20 0 GAGE OK 53 35 63 40 / 20 30 20 0 PONCA CITY OK 58 38 61 39 / 20 30 20 0 DURANT OK 81 46 63 42 / 20 70 20 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 24-SHORT 06-LONG ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 1115 PM CDT WED OCT 18 2006 .AVIATION... WIDESPREAD MVFR CIGS OF OVC010-020 ACROSS MUCH OF WEST CENTRAL TEXAS LATE THIS EVENING. HOWEVER SOME BREAKS OUR OCCURRING ACROSS THE BIG COUNTRY. THE LOW LEVEL CLOUDS WILL CONTINUE TO SLOWLY DISSIPATE ACROSS THE NORTHERN 2/3 OF WEST CENTRAL TEXAS THROUGH 19/12Z...THEN BREAK UP ALONG THE I-10 CORRIDOR BY 19/15Z. SFC HIGH PRESSURE WILL BUILD INTO WEST CENTRAL TEXAS ON THURSDAY...BRINGING MAINLY VFR CONDITIONS AND LIGHT SURFACE WINDS AFTER 19/18Z. 21 && .PREV DISCUSSION... (ISSUED 857 PM CDT WED OCT 18 2006) UPDATE... SEVERE STORM THREAT CONTINUES TO DIMINISH AND HAVE DROPPED THE LAST FEW COUNTIES FROM THE WATCH. HAVE ALSO TWEAKED POPS DOWN ACROSS THE SOUTHEAST COUNTIES...ALTHOUGH WITH UPPER SYSTEM APPROACHING FROM THE WEST...WILL LEAVE SMALL POPS IN FOR LATER TONIGHT AND INTO THURSDAY MORNING. PREV DISCUSSION... (ISSUED 744 PM CDT WED OCT 18 2006) UPDATE... HAVE CLEARED A FEW COUNTIES FROM THE SEVERE THUNDERSTORM WATCH. COLD FRONT HAVE PUSHED SOUTH OF THE AREA THIS EVENING...AND CONTINUES TO PUSH SOUTH AT A DECENT PACE. CAN NOT RULE OUT A STRAY ELEVATED STORM WITH SOME HAIL BACK INTO THE EXTREME SOUTH AND SOUTHEAST PORTIONS OF THE AREA...BUT AREAS LIKE BROWNWOOD AND BRADY NOW LOOK LIKE THEY ARE WELL BACK INTO THE COOLER AIR. HAVE ALSO MADE A FEW ADJUSTMENTS FOR CURRENT CONDITIONS...BUT HAVE LEFT MOST OF THE FORECAST GRIDS ALONE FOR NOW. WILL START TWEAKING THESE AS WELL...BUT MORE ON THAT LATER. PREV DISCUSSION... (ISSUED 200 PM CDT WED OCT 18 2006) SHORT TERM... THERE IS A POTENT UPPER LEVEL LOW NEAR THE SOUTHWEST EXTENT OF A TROUGH THAT EXTENDS FROM THE NORTHERN U.S. PLAINS TO THE NORTHERN BAJA PENINSULA CURRENTLY OVER NORTH CENTRAL AZ TODAY...WHICH IS BEGINNING TO MAKE ITS TURN TO THE EAST TOWARD WEST CENTRAL TEXAS. DRY SOUTHWEST FLOW IS CURRENTLY OVER THE AREA TODAY WITH A COLD FRONT HURTLING THROUGH THE CWA TODAY AT THE SURFACE BRINGING LOW CLOUDS AND COLDER TEMPERATURES INTO THE AREA. ALTHOUGH THE 250MB WINDS ALONG THE EAST SIDE OF THE UPPER LEVEL TROUGH ARE STRONG...700MB WINDS ARE 20-30 KT. THIS IS ALLOWING THE FRONT TO MAKE ITS ADVANCE TO THE SOUTH DURING THE DAY TODAY...ALTHOUGH CAN SEE THAT THE LOW CLOUDS HAVE SLOWED THEIR ADVANCE. CAN SEE CUMULUS BEGINNING TO BUILD OVER OUR SOUTHERN AND EASTERN COUNTIES. SOUTH OF THE FRONT...MOIST AND UNSTABLE AIR REMAINS IN PLACE. THE FRONT MAY INTERACT WITH THIS UNSTABLE AIR AND RESULT IN A FOCUS FOR THUNDERSTORMS TO DEVELOP OVER THE NORTHWEST HILL COUNTRY AND SOUTHERN HEARTLAND AREAS LATER THIS AFTERNOON. HOWEVER...WITH THE CURRENT SPEED OF THE FRONT...THE SOUTHERN HEARTLAND AREA MAY BE NORTH OF THE FRONT BY LATE THIS AFTERNOON. THIS WOULD KEEP SFC BASED INITIATION OF CONVECTION TO THE SOUTH OF THIS AREA FOR TONIGHT. THE SOUTHERN HEARTLAND COULD STILL BE AFFECTED AS THE STORMS MOVE NORTHEAST. WITH THE APPROACHING UPPER LEVEL SHORTWAVE BRINGING IN MORE LIFT COMBINING WITH THE FRONT...WILL KEEP THE GOOD TO LIKELY CHANCE FOR THUNDERSTORMS OVER THE SOUTHEASTERN COUNTIES...AND AT LEAST A SLIGHT CHANCE FOR MOST OTHER AREAS. HAVE ONLY ISOLATED SHRA FOR SOUTHWESTERN AREAS AS THEY SHOULD BE FARTHEST FROM BOTH THE LOW LEVEL MOISTURE AND UPPER LEVEL FORCING. AS FAR AS THE SEVERE THREAT...AIR IS QUITE UNSTABLE OVER THE NORTHWEST HILL COUNTRY WITH LI/S DOWN TO -7 ON 18Z ANALYSIS. KDRT DID SHOW AN INVERSION NEAR 700MB...AND WV SHOWS FAIRLY DRY AIR ALOFT. BUT RUC80 0-6KMB BULK SHEAR VALUES OF 40-50KTS...AND THIS COMBINED WITH INSTABILITY AND THE APPROACHING FRONT DEFINITELY ARGUE FOR LEAVING THE MENTION OF SEVERE IN THE FORECAST TONIGHT. HAVE KEPT LOW TEMPERATURES SIMILAR TO WHAT WAS INHERITED WITH FAIRLY COOL READINGS EXPECTED OVERNIGHT IN THE UPPER 40S TO LOWER 50S ACROSS THE AREA. LONG TERM... ON THURSDAY...THERE MAY BE SOME LINGERING SHRA/TSRA FOR THE EXTREME EASTERN AND SOUTHEASTERN AREAS DURING THE MORNING HOURS...BUT THE UPPER LEVEL WAVE WILL BE QUICKLY MOVING OUT OF THE FORECAST AREA BRINGING IN DRY...SINKING AIR. HAVE KEPT SOME CLOUDS AROUND DURING THE MORNING AS WELL FOR MOST OF THE AREA...BUT EXPECT CLOUDCOVER TO SHARPLY DECREASE FROM WEST TO EAST AS THE SYSTEM MOVES OUT OF THE REGION. HAVE WARMED TOMORROW/S HIGHS A COUPLE DEGREES SINCE WE ARE EXPECTING SOME SUNSHINE TOMORROW AND THAT SHOULD ALLOW TEMPERATURES TO CLIMB BACK INTO THE MID 60S AT LEAST OVER MOST OF THE AREA. NORTHWEST FLOW TOMORROW TRANSITIONS INTO ZONAL FLOW FOR FRIDAY INTO SATURDAY MORNING AHEAD OF THE NEXT TROUGH. THIS WILL ALLOW FOR TEMPERATURES TO WARM NICELY BACK INTO THE 70S TO NEAR 80 BEFORE THE NEXT FRONT MOVES THROUGH SATURDAY/SATURDAY NIGHT. TIMING FOR THIS FRONT REMAINS UNCERTAIN...BUT COULD BE SIMILAR TO TODAY WITH THE FRONT MOVING THROUGH DURING THE DAY. AT THIS TIME...IT APPEARS LATER...MOVING INTO THE BIG COUNTRY BY EVENING...AND THROUGH THE REST OF THE CWA SATURDAY NIGHT. BUT THE FRONT COULD SPEED UP BETWEEN NOW AND SATURDAY...AND ACTUALLY ARRIVE A BIT EARLIER. WILL KEEP WATCHING THIS AS WE MOVE CLOSER TO SATURDAY. REGARDLESS...RIGHT NOW IT LOOKS LIKE SUNDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN THE 60S...WITH TEMPERATURES REBOUNDING DURING THE FIRST HALF OF NEXT WEEK. HAVE OPTED TO KEEP POPS OUT OF THE FORECAST FOR THE NEXT FRONT. WITH THE STRENGTH OF THIS FRONT...RICH LOW LEVEL MOISTURE WILL BE PUSHED WELL SOUTH OF THE REGION...LIMITING THE RETURN AND CHANCE FOR PRECIP WITH SATURDAY/S FRONT. .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 857 PM CDT WED OCT 18 2006 .UPDATE... SEVERE STORM THREAT CONTINUES TO DIMINISH AND HAVE DROPPED THE LAST FEW COUNTIES FROM THE WATCH. HAVE ALSO TWEAKED POPS DOWN ACROSS THE SOUTHEAST COUNTIES...ALTHOUGH WITH UPPER SYSTEM APPROACHING FROM THE WEST...WILL LEAVE SMALL POPS IN FOR LATER TONIGHT AND INTO THURSDAY MORNING. && .PREV DISCUSSION... (ISSUED 744 PM CDT WED OCT 18 2006) UPDATE... HAVE CLEARED A FEW COUNTIES FROM THE SEVERE THUNDERSTORM WATCH. COLD FRONT HAVE PUSHED SOUTH OF THE AREA THIS EVENING...AND CONTINUES TO PUSH SOUTH AT A DECENT PACE. CAN NOT RULE OUT A STRAY ELEVATED STORM WITH SOME HAIL BACK INTO THE EXTREME SOUTH AND SOUTHEAST PORTIONS OF THE AREA...BUT AREAS LIKE BROWNWOOD AND BRADY NOW LOOK LIKE THEY ARE WELL BACK INTO THE COOLER AIR. HAVE ALSO MADE A FEW ADJUSTMENTS FOR CURRENT CONDITIONS...BUT HAVE LEFT MOST OF THE FORECAST GRIDS ALONE FOR NOW. WILL START TWEAKING THESE AS WELL...BUT MORE ON THAT LATER. PREV DISCUSSION... (ISSUED 636 PM CDT WED OCT 18 2006) AVIATION... LOW CLOUDS THAT HAVE BEEN DRAPED ACROSS KABI MOST OF THE DAY FINALLY STARTING TO MAKE IT TO KSJT EARLY THIS EVENING. LOWEST CLOUDS ARE IN A BANK WHICH WILL PERSIST FOR A FEW HOURS...AND THEN BEGIN TO RISE. AT KABI...CEILINGS HAVE RISEN JUST A TAD OVER THE LAST FEW HOURS...AND SHOULD CONTINUE TO SLOWLY CLIMB. STILL TALKING ABOUT MVFR CEILINGS THROUGH MUCH OF THE NIGHT HOWEVER. AT KSJT...EXPECT CEILINGS TO DROP THROUGH 01Z OR 02...PERHAPS REACHING BELOW 1K FEET...WITH CEILINGS AGAIN CLIMBING BY 06Z. IN EITHER CASE...APPEARS THAT CLOUDS WILL BEGIN TO SCATTER OUT THURSDAY MORNING. PREV DISCUSSION... (ISSUED 200 PM CDT WED OCT 18 2006) SHORT TERM... THERE IS A POTENT UPPER LEVEL LOW NEAR THE SOUTHWEST EXTENT OF A TROUGH THAT EXTENDS FROM THE NORTHERN U.S. PLAINS TO THE NORTHERN BAJA PENINSULA CURRENTLY OVER NORTH CENTRAL AZ TODAY...WHICH IS BEGINNING TO MAKE ITS TURN TO THE EAST TOWARD WEST CENTRAL TEXAS. DRY SOUTHWEST FLOW IS CURRENTLY OVER THE AREA TODAY WITH A COLD FRONT HURTLING THROUGH THE CWA TODAY AT THE SURFACE BRINGING LOW CLOUDS AND COLDER TEMPERATURES INTO THE AREA. ALTHOUGH THE 250MB WINDS ALONG THE EAST SIDE OF THE UPPER LEVEL TROUGH ARE STRONG...700MB WINDS ARE 20-30 KT. THIS IS ALLOWING THE FRONT TO MAKE ITS ADVANCE TO THE SOUTH DURING THE DAY TODAY...ALTHOUGH CAN SEE THAT THE LOW CLUODS HAVE SLOWED THEIR ADVANCE. CAN SEE CUMULUS BEGINNING TO BUILD OVER OUR SOUTHERN AND EASTERN COUNTIES. SOUTH OF THE FRONT...MOIST AND UNSTABLE AIR REMAINS IN PLACE. THE FRONT MAY INTERACT WITH THIS UNSTABLE AIR AND RESULT IN A FOCUS FOR THUNDERSTORMS TO DEVELOP OVER THE NORTHWEST HILL COUNTRY AND SOUTHERN HEARTLAND AREAS LATER THIS AFTERNOON. HOWEVER...WITH THE CURRENT SPEED OF THE FRONT...THE SOUTHERN HEARTLAND AREA MAY BE NORTH OF THE FRONT BY LATE THIS AFTERNOON. THIS WOULD KEEP SFC BASED INITIATION OF CONVECTION TO THE SOUTH OF THIS AREA FOR TONIGHT. THE SOUTHERN HEARTLAND COULD STILL BE AFFECTED AS THE STORMS MOVE NORTHEAST. WITH THE APPROACHING UPPER LEVEL SHORTWAVE BRINGING IN MORE LIFT COMBINING WITH THE FRONT...WILL KEEP THE GOOD TO LIKELY CHANCE FOR THUNDERSTORMS OVER THE SOUTHEASTERN COUNTIES...AND AT LEAST A SLIGHT CHANCE FOR MOST OTHER AREAS. HAVE ONLY ISOLATED SHRA FOR SOUTHWESTERN AREAS AS THEY SHOULD BE FARTHEST FROM BOTH THE LOW LEVEL MOISTURE AND UPPER LEVEL FORCING. AS FAR AS THE SEVERE THREAT...AIR IS QUITE UNSTABLE OVER THE NORTHWEST HILL COUNTRY WITH LI/S DOWN TO -7 ON 18Z ANALYSIS. KDRT DID SHOW AN INVERSION NEAR 700MB...AND WV SHOWS FAIRLY DRY AIR ALOFT. BUT RUC80 0-6KMB BULK SHEAR VALUES OF 40-50KTS...AND THIS COMBINED WITH INSTABILITY AND THE APPROACHING FRONT DEFINITELY ARGUE FOR LEAVING THE MENTION OF SEVERE IN THE FORECAST TONIGHT. HAVE KEPT LOW TEMPERATURES SIMILAR TO WHAT WAS INHERITED WITH FAIRLY COOL READINGS EXPECTED OVERNIGHT IN THE UPPER 40S TO LOWER 50S ACROSS THE AREA. LONG TERM... ON THURSDAY...THERE MAY BE SOME LINGERING SHRA/TSRA FOR THE EXTREME EASTERN AND SOUTHEASTERN AREAS DURING THE MORNING HOURS...BUT THE UPPER LEVEL WAVE WILL BE QUICKLY MOVING OUT OF THE FORECAST AREA BRINGING IN DRY...SINKING AIR. HAVE KEPT SOME CLOUDS AROUND DURING THE MORNING AS WELL FOR MOST OF THE AREA...BUT EXPECT CLOUDCOVER TO SHARPLY DECREASE FROM WEST TO EAST AS THE SYSTEM MOVES OUT OF THE REGION. HAVE WARMED TOMORROW/S HIGHS A COUPLE DEGREES SINCE WE ARE EXPECTING SOME SUNSHINE TOMORROW AND THAT SHOULD ALLOW TEMPERATURES TO CLIMB BACK INTO THE MID 60S AT LEAST OVER MOST OF THE AREA. NORTHWEST FLOW TOMORROW TRANSITIONS INTO ZONAL FLOW FOR FRIDAY INTO SATURDAY MORNING AHEAD OF THE NEXT TROUGH. THIS WILL ALLOW FOR TEMPERATURES TO WARM NICELY BACK INTO THE 70S TO NEAR 80 BEFORE THE NEXT FRONT MOVES THROUGH SATURDAY/SATURDAY NIGHT. TIMING FOR THIS FRONT REMAINS UNCERTAIN...BUT COULD BE SIMILAR TO TODAY WITH THE FRONT MOVING THROUGH DURING THE DAY. AT THIS TIME...IT APPEARS LATER...MOVING INTO THE BIG COUNTRY BY EVENING...AND THROUGH THE REST OF THE CWA SATURDAY NIGHT. BUT THE FRONT COULD SPEED UP BETWEEN NOW AND SATURDAY...AND ACTUALLY ARRIVE A BIT EARLIER. WILL KEEP WATCHING THIS AS WE MOVE CLOSER TO SATURDAY. REGARDLESS...RIGHT NOW IT LOOKS LIKE SUNDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN THE 60S...WITH TEMPERATURES REBOUNDING DURING THE FIRST HALF OF NEXT WEEK. HAVE OPTED TO KEEP POPS OUT OF THE FORECAST FOR THE NEXT FRONT. WITH THE STRENGTH OF THIS FRONT...RICH LOW LEVEL MOISTURE WILL BE PUSHED WELL SOUTH OF THE REGION...LIMITING THE RETURN AND CHANCE FOR PRECIP WITH SATURDAY/S FRONT. SJT WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 10 PM WEDNESDAY FOR THE FOLLOWING ZONES: BROWN...KIMBLE...MASON...MCCULLOCH...MENARD... SAN SABA...AND SUTTON. $$ SJT WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 10 PM WEDNESDAY FOR THE FOLLOWING ZONES: KIMBLE...MASON...SAN SABA...AND SUTTON. $$ && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 744 PM CDT WED OCT 18 2006 .UPDATE... HAVE CLEARED A FEW COUNTIES FROM THE SEVERE THUNDERSTORM WATCH. COLD FRONT HAVE PUSHED SOUTH OF THE AREA THIS EVENING...AND CONTINUES TO PUSH SOUTH AT A DECENT PACE. CAN NOT RULE OUT A STRAY ELEVATED STORM WITH SOME HAIL BACK INTO THE EXTREME SOUTH AND SOUTHEAST PORTIONS OF THE AREA...BUT AREAS LIKE BROWNWOOD AND BRADY NOW LOOK LIKE THEY ARE WELL BACK INTO THE COOLER AIR. HAVE ALSO MADE A FEW ADJUSTMENTS FOR CURRENT CONDITIONS...BUT HAVE LEFT MOST OF THE FORECAST GRIDS ALONE FOR NOW. WILL START TWEAKING THESE AS WELL...BUT MORE ON THAT LATER. && .PREV DISCUSSION... (ISSUED 636 PM CDT WED OCT 18 2006) AVIATION... LOW CLOUDS THAT HAVE BEEN DRAPED ACROSS KABI MOST OF THE DAY FINALLY STARTING TO MAKE IT TO KSJT EARLY THIS EVENING. LOWEST CLOUDS ARE IN A BANK WHICH WILL PERSIST FOR A FEW HOURS...AND THEN BEGIN TO RISE. AT KABI...CEILINGS HAVE RISEN JUST A TAD OVER THE LAST FEW HOURS...AND SHOULD CONTINUE TO SLOWLY CLIMB. STILL TALKING ABOUT MVFR CEILINGS THROUGH MUCH OF THE NIGHT HOWEVER. AT KSJT...EXPECT CEILINGS TO DROP THROUGH 01Z OR 02...PERHAPS REACHING BELOW 1K FEET...WITH CEILINGS AGAIN CLIMBING BY 06Z. IN EITHER CASE...APPEARS THAT CLOUDS WILL BEGIN TO SCATTER OUT THURSDAY MORNING. PREV DISCUSSION... (ISSUED 200 PM CDT WED OCT 18 2006) SHORT TERM... THERE IS A POTENT UPPER LEVEL LOW NEAR THE SOUTHWEST EXTENT OF A TROUGH THAT EXTENDS FROM THE NORTHERN U.S. PLAINS TO THE NORTHERN BAJA PENINSULA CURRENTLY OVER NORTH CENTRAL AZ TODAY...WHICH IS BEGINNING TO MAKE ITS TURN TO THE EAST TOWARD WEST CENTRAL TEXAS. DRY SOUTHWEST FLOW IS CURRENTLY OVER THE AREA TODAY WITH A COLD FRONT HURTLING THROUGH THE CWA TODAY AT THE SURFACE BRINGING LOW CLOUDS AND COLDER TEMPERATURES INTO THE AREA. ALTHOUGH THE 250MB WINDS ALONG THE EAST SIDE OF THE UPPER LEVEL TROUGH ARE STRONG...700MB WINDS ARE 20-30 KT. THIS IS ALLOWING THE FRONT TO MAKE ITS ADVANCE TO THE SOUTH DURING THE DAY TODAY...ALTHOUGH CAN SEE THAT THE LOW CLUODS HAVE SLOWED THEIR ADVANCE. CAN SEE CUMULUS BEGINNING TO BUILD OVER OUR SOUTHERN AND EASTERN COUNTIES. SOUTH OF THE FRONT...MOIST AND UNSTABLE AIR REMAINS IN PLACE. THE FRONT MAY INTERACT WITH THIS UNSTABLE AIR AND RESULT IN A FOCUS FOR THUNDERSTORMS TO DEVELOP OVER THE NORTHWEST HILL COUNTRY AND SOUTHERN HEARTLAND AREAS LATER THIS AFTERNOON. HOWEVER...WITH THE CURRENT SPEED OF THE FRONT...THE SOUTHERN HEARTLAND AREA MAY BE NORTH OF THE FRONT BY LATE THIS AFTERNOON. THIS WOULD KEEP SFC BASED INITIATION OF CONVECTION TO THE SOUTH OF THIS AREA FOR TONIGHT. THE SOUTHERN HEARTLAND COULD STILL BE AFFECTED AS THE STORMS MOVE NORTHEAST. WITH THE APPROACHING UPPER LEVEL SHORTWAVE BRINGING IN MORE LIFT COMBINING WITH THE FRONT...WILL KEEP THE GOOD TO LIKELY CHANCE FOR THUNDERSTORMS OVER THE SOUTHEASTERN COUNTIES...AND AT LEAST A SLIGHT CHANCE FOR MOST OTHER AREAS. HAVE ONLY ISOLATED SHRA FOR SOUTHWESTERN AREAS AS THEY SHOULD BE FARTHEST FROM BOTH THE LOW LEVEL MOISTURE AND UPPER LEVEL FORCING. AS FAR AS THE SEVERE THREAT...AIR IS QUITE UNSTABLE OVER THE NORTHWEST HILL COUNTRY WITH LI/S DOWN TO -7 ON 18Z ANALYSIS. KDRT DID SHOW AN INVERSION NEAR 700MB...AND WV SHOWS FAIRLY DRY AIR ALOFT. BUT RUC80 0-6KMB BULK SHEAR VALUES OF 40-50KTS...AND THIS COMBINED WITH INSTABILITY AND THE APPROACHING FRONT DEFINITELY ARGUE FOR LEAVING THE MENTION OF SEVERE IN THE FORECAST TONIGHT. HAVE KEPT LOW TEMPERATURES SIMILAR TO WHAT WAS INHERITED WITH FAIRLY COOL READINGS EXPECTED OVERNIGHT IN THE UPPER 40S TO LOWER 50S ACROSS THE AREA. LONG TERM... ON THURSDAY...THERE MAY BE SOME LINGERING SHRA/TSRA FOR THE EXTREME EASTERN AND SOUTHEASTERN AREAS DURING THE MORNING HOURS...BUT THE UPPER LEVEL WAVE WILL BE QUICKLY MOVING OUT OF THE FORECAST AREA BRINGING IN DRY...SINKING AIR. HAVE KEPT SOME CLOUDS AROUND DURING THE MORNING AS WELL FOR MOST OF THE AREA...BUT EXPECT CLOUDCOVER TO SHARPLY DECREASE FROM WEST TO EAST AS THE SYSTEM MOVES OUT OF THE REGION. HAVE WARMED TOMORROW/S HIGHS A COUPLE DEGREES SINCE WE ARE EXPECTING SOME SUNSHINE TOMORROW AND THAT SHOULD ALLOW TEMPERATURES TO CLIMB BACK INTO THE MID 60S AT LEAST OVER MOST OF THE AREA. NORTHWEST FLOW TOMORROW TRANSITIONS INTO ZONAL FLOW FOR FRIDAY INTO SATURDAY MORNING AHEAD OF THE NEXT TROUGH. THIS WILL ALLOW FOR TEMPERATURES TO WARM NICELY BACK INTO THE 70S TO NEAR 80 BEFORE THE NEXT FRONT MOVES THROUGH SATURDAY/SATURDAY NIGHT. TIMING FOR THIS FRONT REMAINS UNCERTAIN...BUT COULD BE SIMILAR TO TODAY WITH THE FRONT MOVING THROUGH DURING THE DAY. AT THIS TIME...IT APPEARS LATER...MOVING INTO THE BIG COUNTRY BY EVENING...AND THROUGH THE REST OF THE CWA SATURDAY NIGHT. BUT THE FRONT COULD SPEED UP BETWEEN NOW AND SATURDAY...AND ACTUALLY ARRIVE A BIT EARLIER. WILL KEEP WATCHING THIS AS WE MOVE CLOSER TO SATURDAY. REGARDLESS...RIGHT NOW IT LOOKS LIKE SUNDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN THE 60S...WITH TEMPERATURES REBOUNDING DURING THE FIRST HALF OF NEXT WEEK. HAVE OPTED TO KEEP POPS OUT OF THE FORECAST FOR THE NEXT FRONT. WITH THE STRENGTH OF THIS FRONT...RICH LOW LEVEL MOISTURE WILL BE PUSHED WELL SOUTH OF THE REGION...LIMITING THE RETURN AND CHANCE FOR PRECIP WITH SATURDAY/S FRONT. SJT WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 10 PM WEDNESDAY FOR THE FOLLOWING ZONES: BROWN...KIMBLE...MASON...MCCULLOCH...MENARD... SAN SABA...AND SUTTON. $$ && .SJT WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 10 PM WEDNESDAY FOR THE FOLLOWING ZONES: KIMBLE...MASON...SAN SABA...AND SUTTON. && $$ 07 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 636 PM CDT WED OCT 18 2006 .AVIATION... LOW CLOUDS THAT HAVE BEEN DRAPED ACROSS KABI MOST OF THE DAY FINALLY STARTING TO MAKE IT TO KSJT EARLY THIS EVENING. LOWEST CLOUDS ARE IN A BANK WHICH WILL PERSIST FOR A FEW HOURS...AND THEN BEGIN TO RISE. AT KABI...CEILINGS HAVE RISEN JUST A TAD OVER THE LAST FEW HOURS...AND SHOULD CONTINUE TO SLOWLY CLIMB. STILL TALKING ABOUT MVFR CEILINGS THROUGH MUCH OF THE NIGHT HOWEVER. AT KSJT...EXPECT CEILINGS TO DROP THROUGH 01Z OR 02...PERHAPS REACHING BELOW 1K FEET...WITH CEILINGS AGAIN CLIMBING BY 06Z. IN EITHER CASE...APPEARS THAT CLOUDS WILL BEGIN TO SCATTER OUT THURSDAY MORNING. && .PREV DISCUSSION... (ISSUED 200 PM CDT WED OCT 18 2006) SHORT TERM... THERE IS A POTENT UPPER LEVEL LOW NEAR THE SOUTHWEST EXTENT OF A TROUGH THAT EXTENDS FROM THE NORTHERN U.S. PLAINS TO THE NORTHERN BAJA PENINSULA CURRENTLY OVER NORTH CENTRAL AZ TODAY...WHICH IS BEGINNING TO MAKE ITS TURN TO THE EAST TOWARD WEST CENTRAL TEXAS. DRY SOUTHWEST FLOW IS CURRENTLY OVER THE AREA TODAY WITH A COLD FRONT HURTLING THROUGH THE CWA TODAY AT THE SURFACE BRINGING LOW CLOUDS AND COLDER TEMPERATURES INTO THE AREA. ALTHOUGH THE 250MB WINDS ALONG THE EAST SIDE OF THE UPPER LEVEL TROUGH ARE STRONG...700MB WINDS ARE 20-30 KT. THIS IS ALLOWING THE FRONT TO MAKE ITS ADVANCE TO THE SOUTH DURING THE DAY TODAY...ALTHOUGH CAN SEE THAT THE LOW CLUODS HAVE SLOWED THEIR ADVANCE. CAN SEE CUMULUS BEGINNING TO BUILD OVER OUR SOUTHERN AND EASTERN COUNTIES. SOUTH OF THE FRONT...MOIST AND UNSTABLE AIR REMAINS IN PLACE. THE FRONT MAY INTERACT WITH THIS UNSTABLE AIR AND RESULT IN A FOCUS FOR THUNDERSTORMS TO DEVELOP OVER THE NORTHWEST HILL COUNTRY AND SOUTHERN HEARTLAND AREAS LATER THIS AFTERNOON. HOWEVER...WITH THE CURRENT SPEED OF THE FRONT...THE SOUTHERN HEARTLAND AREA MAY BE NORTH OF THE FRONT BY LATE THIS AFTERNOON. THIS WOULD KEEP SFC BASED INITIATION OF CONVECTION TO THE SOUTH OF THIS AREA FOR TONIGHT. THE SOUTHERN HEARTLAND COULD STILL BE AFFECTED AS THE STORMS MOVE NORTHEAST. WITH THE APPROACHING UPPER LEVEL SHORTWAVE BRINGING IN MORE LIFT COMBINING WITH THE FRONT...WILL KEEP THE GOOD TO LIKELY CHANCE FOR THUNDERSTORMS OVER THE SOUTHEASTERN COUNTIES...AND AT LEAST A SLIGHT CHANCE FOR MOST OTHER AREAS. HAVE ONLY ISOLATED SHRA FOR SOUTHWESTERN AREAS AS THEY SHOULD BE FARTHEST FROM BOTH THE LOW LEVEL MOISTURE AND UPPER LEVEL FORCING. AS FAR AS THE SEVERE THREAT...AIR IS QUITE UNSTABLE OVER THE NORTHWEST HILL COUNTRY WITH LI/S DOWN TO -7 ON 18Z ANALYSIS. KDRT DID SHOW AN INVERSION NEAR 700MB...AND WV SHOWS FAIRLY DRY AIR ALOFT. BUT RUC80 0-6KMB BULK SHEAR VALUES OF 40-50KTS...AND THIS COMBINED WITH INSTABILITY AND THE APPROACHING FRONT DEFINITELY ARGUE FOR LEAVING THE MENTION OF SEVERE IN THE FORECAST TONIGHT. HAVE KEPT LOW TEMPERATURES SIMILAR TO WHAT WAS INHERITED WITH FAIRLY COOL READINGS EXPECTED OVERNIGHT IN THE UPPER 40S TO LOWER 50S ACROSS THE AREA. LONG TERM... ON THURSDAY...THERE MAY BE SOME LINGERING SHRA/TSRA FOR THE EXTREME EASTERN AND SOUTHEASTERN AREAS DURING THE MORNING HOURS...BUT THE UPPER LEVEL WAVE WILL BE QUICKLY MOVING OUT OF THE FORECAST AREA BRINGING IN DRY...SINKING AIR. HAVE KEPT SOME CLOUDS AROUND DURING THE MORNING AS WELL FOR MOST OF THE AREA...BUT EXPECT CLOUDCOVER TO SHARPLY DECREASE FROM WEST TO EAST AS THE SYSTEM MOVES OUT OF THE REGION. HAVE WARMED TOMORROW/S HIGHS A COUPLE DEGREES SINCE WE ARE EXPECTING SOME SUNSHINE TOMORROW AND THAT SHOULD ALLOW TEMPERATURES TO CLIMB BACK INTO THE MID 60S AT LEAST OVER MOST OF THE AREA. NORTHWEST FLOW TOMORROW TRANSITIONS INTO ZONAL FLOW FOR FRIDAY INTO SATURDAY MORNING AHEAD OF THE NEXT TROUGH. THIS WILL ALLOW FOR TEMPERATURES TO WARM NICELY BACK INTO THE 70S TO NEAR 80 BEFORE THE NEXT FRONT MOVES THROUGH SATURDAY/SATURDAY NIGHT. TIMING FOR THIS FRONT REMAINS UNCERTAIN...BUT COULD BE SIMILAR TO TODAY WITH THE FRONT MOVING THROUGH DURING THE DAY. AT THIS TIME...IT APPEARS LATER...MOVING INTO THE BIG COUNTRY BY EVENING...AND THROUGH THE REST OF THE CWA SATURDAY NIGHT. BUT THE FRONT COULD SPEED UP BETWEEN NOW AND SATURDAY...AND ACTUALLY ARRIVE A BIT EARLIER. WILL KEEP WATCHING THIS AS WE MOVE CLOSER TO SATURDAY. REGARDLESS...RIGHT NOW IT LOOKS LIKE SUNDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN THE 60S...WITH TEMPERATURES REBOUNDING DURING THE FIRST HALF OF NEXT WEEK. HAVE OPTED TO KEEP POPS OUT OF THE FORECAST FOR THE NEXT FRONT. WITH THE STRENGTH OF THIS FRONT...RICH LOW LEVEL MOISTURE WILL BE PUSHED WELL SOUTH OF THE REGION...LIMITING THE RETURN AND CHANCE FOR PRECIP WITH SATURDAY/S FRONT. && .SJT WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 10 PM WEDNESDAY FOR THE FOLLOWING ZONES: BROWN...KIMBLE...MASON...MCCULLOCH...MENARD... SAN SABA...AND SUTTON. && $$ 07 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 303 PM CDT WED OCT 18 2006 .SHORT TERM... UPPER LOW OVER ARIZONA CONTINUES TO MOVE SEWD WITH MDCARS DATA SHOWING POSSIBLY ONE MORE JET STREAK TO ROUND THE BASE OF THE TROUGH BEFORE IT EJECTS QUICKLY EWD. SOME MINOR TIMING ISSUES WITH THE TROUGH PASSAGE AND THUS PRECIP CHANCES WITH THE RUC AND WRF SLOWER THAN THE GFS. HARD TO PREFER ONE OVER THE OTHER ATTM AND WILL HOLD CLOSE TO PREVIOUS TIMING. MID AND UPPER LEVEL LIFT HAS ALREADY BECOME EVIDENT WITH EXPANDING CLOUD SHIELD OVER SRN AND CNTL NEW MEXICO AND MID LEVEL REFLECTIVITY RETURNS OVER ERN NEW MEXICO PER 88-D. BEST LIFT STILL APPEARS TO CROSS THE FCST AREA OVERNIGHT WITH SOME MOISTENING OF THE SUB-CLOUD LAYER NEEDED BEFORE PRECIP REACHES THE GROUND. HOWEVER IT DOES LOOKS LIKE A DECENT AREA OF LIGHT RAIN WILL DEVELOP AS IT CROSSES THE AREA BEFORE UNDERGOING SOME WEAKENING LATER TONIGHT. WILL BUMP POPS UP TO THE LIKELY CATEGORY FOR AREAS ON THE CAPROCK AND TO HIGH CHANCE CATEGORY FOR THE ROLLING PLAINS. AGAIN SOME MODEL RELATED TIMING ISSUES TO CLEARING SKIES BEHIND THE TROUGH...BUT SHOULD BE CLEAR BY EARLY AFTERNOON. WINDS WILL COME AROUND TO A WLY COMPONENT MOST LOCATIONS BY AFTERNOON BUT ADDED DOWNSLOPING WILL BE MINIMAL WITH MOST EFFECT NEAR THE NEW MEXICO LINE. GUIDANCE VALUES ARE VERY CLOSE FOR TONIGHT AND ARE GENERALLY ACCEPTED. FOR HIGHS THURSDAY A LITTLE MORE SPREAD. GIVEN COOL AIR MASS AND CONTINUED MOIST GROUND WILL CONTINUE TOWARD THE COOLER SIDE ATTM. .LONG TERM... DEVELOPING LEE-TROUGH ON FRI WILL RESULT IN WINDS COMING AROUND BACK TO THE S-SW AND BRING A WARMUP BACK INTO THE 70S WITH MOSTLY CLEAR SKIES. NEXT UPPER-LEVEL TROUGH WILL SE THROUGH THE ROCKIES AND INTO THE PLAINS SAT. LATEST MODEL RUNS INDICATE THE FRONT PASSING THROUGH THE CWA DURING THE DAY SAT. THE EXACT TIMING WILL AFFECT SAT MAX TEMPS...CURRENT INDICATIONS ARE THAT SRN COUNTIES WILL BE ABLE TO WARM WELL INTO THE 70S IN THE PRE-FRONTAL SFC TROUGH...WHILE NORTHERN COUNTIES MAY SEE WIND SHIFT AND CAA BEFORE PEAK HEATING....THUS LEADING TO A DECENT TEMP GRADIENT ACROSS THE CWA. THIS LIKELY TO BE ADJUSTED AS FUTURE SOLUTIONS CONVERGE. IT APPEARS THAT THE BEST MOISTURE AND LIFT WILL REMAIN NORTH OF THE CWA...LIMITING PRECIP CHCS...HOWEVER WILL HAVE TO WATCH FOR LOW CLOUDS TO MOVE IN SAT EVE THROUGH SUN MORN. HAVE WENT WITH SOME CLOUD COVER SUN MORN IN THE GRIDS AND AS SUCH MIN TEMPS WILL NOT BOTTOM OUT...WITH CLOUD COVER BREAKING UP DURING THE DAY SUN. TEMPS ON SUN MAY NOT MAKE IT OUT OF THE 50S AND MONDAY MAY BE THE COLDEST MORNING IF CLEAR SKIES AND LIGHT WINDS VERIFY. TEMPS MAY APPROACH FREEZING IN THE SW PANHANDLE. NORTHWEST FLOW THEN ENSUES EARLY NEXT WEEK WITH A GRADUAL WARMUP COINCIDING WITH THE RE-ESTABLISHMENT OF LEE-TROUGHING. RIDGE AMPLIFIES OVER THE ROCKIES...PROXIMITY OF RIDGE AXIS SHOULD SUPPORT DRY CONDITIONS AND WARMING TREND FOR WTX THROUGH THE MIDDLE OF NEXT WEEK...ALTHOUGH WEAK COLD FRONT PUSHED SOUTH BY SHTWV MOVING FROM THE NRN PLAINS INTO THE MIDWEST COULD APPROACH THE SPLNS IN THE TUE-WED TIME FRAME. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 36 65 41 74 / 70 10 0 0 TULIA 38 64 42 72 / 70 10 0 0 PLAINVIEW 39 64 43 73 / 70 10 0 0 LEVELLAND 42 65 43 75 / 60 10 0 0 LUBBOCK 41 64 44 75 / 60 10 0 0 BROWNFIELD 42 65 45 76 / 50 10 0 0 CHILDRESS 42 63 43 74 / 40 20 0 0 SPUR 45 64 43 74 / 50 20 0 0 ASPERMONT 45 63 45 75 / 40 20 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07/33 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 200 PM CDT WED OCT 18 2006 .SHORT TERM... THERE IS A POTENT UPPER LEVEL LOW NEAR THE SOUTHWEST EXTENT OF A TROUGH THAT EXTENDS FROM THE NORTHERN U.S. PLAINS TO THE NORTHERN BAJA PENINSULA CURRENTLY OVER NORTH CENTRAL AZ TODAY...WHICH IS BEGINNING TO MAKE ITS TURN TO THE EAST TOWARD WEST CENTRAL TEXAS. DRY SOUTHWEST FLOW IS CURRENTLY OVER THE AREA TODAY WITH A COLD FRONT HURTLING THROUGH THE CWA TODAY AT THE SURFACE BRINGING LOW CLOUDS AND COLDER TEMPERATURES INTO THE AREA. ALTHOUGH THE 250MB WINDS ALONG THE EAST SIDE OF THE UPPER LEVEL TROUGH ARE STRONG...700MB WINDS ARE 20-30 KT. THIS IS ALLOWING THE FRONT TO MAKE ITS ADVANCE TO THE SOUTH DURING THE DAY TODAY...ALTHOUGH CAN SEE THAT THE LOW CLUODS HAVE SLOWED THEIR ADVANCE. CAN SEE CUMULUS BEGINNING TO BUILD OVER OUR SOUTHERN AND EASTERN COUNTIES. SOUTH OF THE FRONT...MOIST AND UNSTABLE AIR REMAINS IN PLACE. THE FRONT MAY INTERACT WITH THIS UNSTABLE AIR AND RESULT IN A FOCUS FOR THUNDERSTORMS TO DEVELOP OVER THE NORTHWEST HILL COUNTRY AND SOUTHERN HEARTLAND AREAS LATER THIS AFTERNOON. HOWEVER...WITH THE CURRENT SPEED OF THE FRONT...THE SOUTHERN HEARTLAND AREA MAY BE NORTH OF THE FRONT BY LATE THIS AFTERNOON. THIS WOULD KEEP SFC BASED INITIATION OF CONVECTION TO THE SOUTH OF THIS AREA FOR TONIGHT. THE SOUTHERN HEARTLAND COULD STILL BE AFFECTED AS THE STORMS MOVE NORTHEAST. WITH THE APPROACHING UPPER LEVEL SHORTWAVE BRINGING IN MORE LIFT COMBINING WITH THE FRONT...WILL KEEP THE GOOD TO LIKELY CHANCE FOR THUNDERSTORMS OVER THE SOUTHEASTERN COUNTIES...AND AT LEAST A SLIGHT CHANCE FOR MOST OTHER AREAS. HAVE ONLY ISOLATED SHRA FOR SOUTHWESTERN AREAS AS THEY SHOULD BE FARTHEST FROM BOTH THE LOW LEVEL MOISTURE AND UPPER LEVEL FORCING. AS FAR AS THE SEVERE THREAT...AIR IS QUITE UNSTABLE OVER THE NORTHWEST HILL COUNTRY WITH LI/S DOWN TO -7 ON 18Z ANALYSIS. KDRT DID SHOW AN INVERSION NEAR 700MB...AND WV SHOWS FAIRLY DRY AIR ALOFT. BUT RUC80 0-6KMB BULK SHEAR VALUES OF 40-50KTS...AND THIS COMBINED WITH INSTABILITY AND THE APPROACHING FRONT DEFINITELY ARGUE FOR LEAVING THE MENTION OF SEVERE IN THE FORECAST TONIGHT. HAVE KEPT LOW TEMPERATURES SIMILAR TO WHAT WAS INHERITED WITH FAIRLY COOL READINGS EXPECTED OVERNIGHT IN THE UPPER 40S TO LOWER 50S ACROSS THE AREA. .LONG TERM... ON THURSDAY...THERE MAY BE SOME LINGERING SHRA/TSRA FOR THE EXTREME EASTERN AND SOUTHEASTERN AREAS DURING THE MORNING HOURS...BUT THE UPPER LEVEL WAVE WILL BE QUICKLY MOVING OUT OF THE FORECAST AREA BRINGING IN DRY...SINKING AIR. HAVE KEPT SOME CLOUDS AROUND DURING THE MORNING AS WELL FOR MOST OF THE AREA...BUT EXPECT CLOUDCOVER TO SHARPLY DECREASE FROM WEST TO EAST AS THE SYSTEM MOVES OUT OF THE REGION. HAVE WARMED TOMORROW/S HIGHS A COUPLE DEGREES SINCE WE ARE EXPECTING SOME SUNSHINE TOMORROW AND THAT SHOULD ALLOW TEMPERATURES TO CLIMB BACK INTO THE MID 60S AT LEAST OVER MOST OF THE AREA. NORTHWEST FLOW TOMORROW TRANSITIONS INTO ZONAL FLOW FOR FRIDAY INTO SATURDAY MORNING AHEAD OF THE NEXT TROUGH. THIS WILL ALLOW FOR TEMPERATURES TO WARM NICELY BACK INTO THE 70S TO NEAR 80 BEFORE THE NEXT FRONT MOVES THROUGH SATURDAY/SATURDAY NIGHT. TIMING FOR THIS FRONT REMAINS UNCERTAIN...BUT COULD BE SIMILAR TO TODAY WITH THE FRONT MOVING THROUGH DURING THE DAY. AT THIS TIME...IT APPEARS LATER...MOVING INTO THE BIG COUNTRY BY EVENING...AND THROUGH THE REST OF THE CWA SATURDAY NIGHT. BUT THE FRONT COULD SPEED UP BETWEEN NOW AND SATURDAY...AND ACTUALLY ARRIVE A BIT EARLIER. WILL KEEP WATCHING THIS AS WE MOVE CLOSER TO SATURDAY. REGARDLESS...RIGHT NOW IT LOOKS LIKE SUNDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN THE 60S...WITH TEMPERATURES REBOUNDING DURING THE FIRST HALF OF NEXT WEEK. HAVE OPTED TO KEEP POPS OUT OF THE FORECAST FOR THE NEXT FRONT. WITH THE STRENGTH OF THIS FRONT...RICH LOW LEVEL MOISTURE WILL BE PUSHED WELL SOUTH OF THE REGION...LIMITING THE RETURN AND CHANCE FOR PRECIP WITH SATURDAY/S FRONT. && .PRELIMINARY POINT TEMPS/POPS... ABILENE 45 63 44 76 / 20 10 0 0 SAN ANGELO 50 67 43 77 / 20 20 0 0 JUNCTION 54 67 42 77 / 40 20 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 20 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1005 AM CDT WED OCT 18 2006 .UPDATE...ABUNDANT MOISTURE HAS RAPIDLY RETURNED WITH PRECIPITABLE WATERS NEAR 2.3 INCHES. HOWEVER...THE 12Z CRP SOUNDING SHOWS A STRONG CAP CURRENTLY IN PLACE. BOTH THE NAM AND GFS SHOW THE LOW/MID LEVELS CONTNUING TO MOISTEN WITH THE CAP WEAKENING THROUGH THE AFTERNOON. A JET STREAK NOSING IN FROM THE SW WILL HELP WITH UPPER LEVEL SUPPORT BUT AT THE SFC...A FOCUS IS LACKING. THE SEA BREEZE WILL PROVIDE SOME SFC FORCING THIS AFTERNOON...BUT THE QUESTION IS WILL IT BE STRONG ENOUGH TO BREAK THE CAP. TEMP WOULD ALSO HAVE TO REACH 96 DEGREES AND WITH THE MOISTURE RETURN...AM NOT EXPECTING TO REACH THAT VALUE. THE VCT AREA STILL HAS THE BEST CHC THIS AFTERNOON GIVEN A WEAKER CAP AND PROXIMITY TO STRONGER DYNAMICS. WILL LOWER THE 50 AND 60 POPS FOR TODAY DOWN TO 40 AND 50 PERCENT. THE BEST CHC FOR CONVECTION WILL BE LATE TONIGHT/THURSDAY MORNING WITH THE COLD FRONT. && .PREV DISCUSSION... (ISSUED 445 AM CDT WED OCT 18 2006) SHORT TERM (TODAY THROUGH THURSDAY)...GFS APPEARS TO HAVE A BETTER HANDLE ON MOISTURE FIELDS ACROSS SOUTH TEXAS THROUGH THE PERIOD. GOES SOUNDER SHOWS VERY HIGH MOISTURE CONTENT OVER THE WESTERN GULF OF MEXICO/NORTHEAST MEXICO THAT IS STREAMING NORTHWARD INTO THE LOWER TEXAS COAST. 00Z BROWNSVILLE SOUNDING SHOWED 2.2 INCHES PRECIPITABLE WATER AND GOES SOUNDER INDICATES PWATS AS HIGH AS 2.5 INCHES ATTM. THE GFS SHOWS THIS DEEP MOISTURE MOVING NORTHWARD INTO THE COASTAL BEND BY THIS AFTERNOON. WITH DEWPOINTS REMAINING IN THE UPPER 70S TO POSSIBLY 80 DEGREES...VERY UNSTABLE AIRMASS WILL BE IN PLACE. THE GFS/RUC SHOW CAPE VALUES AS HIGH AS 5000 J/KG WHICH MAY BE A BIT HIGH BUT 3000-4000 J/KG APPEARS REASONABLE. WATER VAPOR IMAGERY SHOWS A WEAK SHORT WAVE TROUGH OVER NORTHEAST MEXICO WITH AN ASSOCIATED UPPER LEVEL JET STREAK THAT IS EXPECTED TO MOVE NORTHEAST THROUGH SOUTH TEXAS TODAY. 0-6 KM SHEAR IS EXPECTED TO INCREASE TO 40-50 KNOTS BY THIS AFTERNOON. CONVECTIVE TEMPS SHOULD BE REACHABLE BY EARLY AFTERNOON AND EXPECT SCATTERED THUNDERSTORMS TO OCCUR OVER THE COASTAL PLAINS. ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE WITH DAMAGING WINDS THE MAIN THREAT. BUT WITH AMOUNT OF CAPE AVAILABLE AND INCREASING SHEAR IN THE MID LEVELS...STORMS EXHIBITING ROTATION COULD LEAD TO INCREASED ISOLATED TORNADO THREAT AS EXPECT LOW LFC (LEVEL OF FREE CONVECTION) LEVELS TO OCCUR WITH SUCH HIGH DEWPOINTS. DEEP WARM AND MOIST LAYER SHOULD LEAD TO LOCALLY HEAVY RAIN THREAT AS WELL. WILL MENTION HEAVY RAIN POSSIBLE IN THE VCT AREA FOR THIS AFTERNOON AND THE REST OF THE COASTAL BEND FOR LATER TONIGHT INTO THURSDAY AS COLD FRONT ADVANCES SOUTH INTO THE FCST AREA. WENT CLOSE TO GFS GUIDANCE OVERNIGHT TONIGHT/THURSDAY MORNING WITH LIKELY POPS MOST AREAS EXCEPT HIGH END CHANCE POPS FAR WEST. A FLOOD WATCH MAY BE NEEDED FOR NORTHEAST COUNTIES FOR TONIGHT IF RAIN GETS EXCESSIVE OVER THE AREA THIS AFTERNOON. WENT CLOSER TO THE GFS FOR TIMING ON THE FRONT. WILL COVER HIGH HEAT INDEX VALUES FOR THIS AFTERNOON IN THE HWO AS WELL AS POSSIBLE SEVERE THUNDERSTORMS. AVIATION...IFR/LIFR CONDITIONS OCCURING WITHIN LOW STRATUS DECK OVER MUCH OF SOUTH TEXAS THIS MORNING. BUT STRATUS IS INHIBITING FOG FROM BECOMING DENSE WITH ONLY A FEW PLACES BELOW 3 MILES...VCT AREA. STRATUS/FOG WILL MAINTAIN IFR/LIFR CONDS OVER THE REGION UNTIL AROUND 15Z...WITH SLOW IMPROVEMENT TO MVFR BETWEEN 15Z-18Z. EXPECT SCATTERED STRONG STORMS TO DEVELOP BY THE AFTERNOON WITHIN VERY UNSTABLE AIRMASS. VERY HEAVY RAIN/LOW CEILINGS WITH STORMS WILL LEAD TO IFR CONDS. OTHERWISE...VFR CONDITIONS ARE EXPECT OUTSIDE OF CONVECTIVE AREAS. A COLD FRONT WILL MOVE INTO THE SOUTH TEXAS AREA BY EARLY THURSDAY MORNING. THE FRONT WILL REACH A VCT-COT LINE BY 11Z THURSDAY AND BE SOUTH OF A NQI-LRD LINE BY 15Z. SCATTERED TO NUMEROUS STORMS ALONG THE FRONT WILL PROVIDE IFR CONDS ALONG AND AHEAD OF THE FRONTAL PASSAGE. MVFR CEILINGS EXPECTED BEHIND THE FRONT THURSDAY AFTERNOON WITH SLOW IMPROVEMENT TO VFR BY LATE IN THE AFTERNOON. MARINE...QUIET CONDITIONS FOR THE MARINE ZONES EARLY THIS MORNING. BUT WITH MOISTURE INFLUX CONTINUING...EXPECT SCATTERED SHOWERS/STORMS TO DEVELOP OVER THE COASTAL WATERS LATER THIS MORNING. MORE ACTIVE WEATHER WILL MOVE INTO THE COASTAL WATERS BY EARLY THURSDAY MORNING IN ADVANCE OF A STRONG COLD FRONT. A MODERATE TO STRONG OFFSHORE FLOW WILL OCCUR IN THE WAKE OF THE FRONT THURSDAY. WILL ISSUE A MARINE WEATHER STATEMENT TO ALERT MARINERS OF CHANGING CONDITIONS EXPECTED BY THURSDAY. LONG-TERM (THURSDAY NIGHT THROUGH TUESDAY)...THE NAM/GFS/ECMWF ARE BASICALLY IN AGREEMENT WITH A DRIER TROPOSPHERIC COLUMN SETTLING IN OVER S TX THURSDAY NIGHT. THE ENVIRONMENT WILL BE CONDUCIVE TO RADIATIVE COOLING SO EXPECT TEMPS TO DROP A COUPLE DEGREES BELOW NORMAL. FRIDAY WILL BE A PLEASANT DAY WITH PARTLY CLOUDY SKIES AND TEMPS A COUPLE DEGREES BELOW NORMAL. AS RETURN FLOW SETS UP LATE FRIDAY NIGHT IN RESPONSE TO HIGH PRESSURE SHIFTING EAST...FRI NIGHT THRU SATURDAY TEMPS WILL BE ABOVE NORMAL. COULD SEE SOME SHOWERS DEVELOP OVER THE COASTAL WATERS AND ALONG THE IMMEDIATE COAST SATURDAY MORNING AS AN AREA OF SFC MOISTURE CONVERGENCE DEVELOPS IN RESPONSE TO A WEAK COASTAL TROUGH. ANOTHER COLD FRONT IS EXPECTED TO PUSH THROUGH THE REGION LATE SATURDAY NIGHT INTO SUNDAY. MOISTURE FIELDS ARE NOT REALLY THAT IMPRESSIVE WITH THE FRONT WITH PWATS BETWEEN 1.5-1.7 INCHES. WILL INDICATE LOW-END CHANCE POPS OVER THE COASTAL PLAINS AND VICTORIA CROSSROADS WHERE THE DEEPEST MOISTURE IS PROGGED TO RESIDE. BELOW NORMAL TEMPS ARE EXPECTED BEHIND THE FRONT ON SUNDAY AS HIGH PRESSURE SETTLES INTO THE REGION. STAYED A COUPLE DEGREES ABOVE MEX GUIDANCE FOR TEMPS BEHIND THE FRONT AS THE RELATIVELY COOLER AIR MASS WILL PROBABLY MODIFY BY THE TIME IT REACHES THE AREA. A GRADUAL WARMING TREND CAN BE EXPECTED MON-TUE AS THE AIR MASS FURTHER MODIFIES IN RESPONSE TO SUBSIDENT NWLY FLOW ALOFT DEVELOPING MONDAY AS A TROUGH DEEPENS OVER THE GREAT LAKES REGION. && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ TE/81...SHORT-TERM WC/87...LONG-TERM tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BLACKSBURG VA 914 AM EDT WED OCT 18 2006 .SHORT TERM /REST OF TODAY/... DENSE FOG ADVISORY EXPIRED AT 13Z...UPDATING TO REMOVE THE HEADLINES...AND MAINLY ADJUSTING WX GRIDS WITH FOG BECOMING PATCHIER. MAIN CONCERN THIS AFTERNOON IS CLOUD COVER HANGING ON IN SE WV-FAR SW VA. FEEL UPSLOPE AND 10Z RUC DEPICTIONS OF CLOUD COVER SUFFICIENT TO RAISE SKY COVERAGE HERE THROUGH THE AFTERNOON. WILL AWAIT 12Z GUIDANCE FOR ANY ADJUSTMENTS INTO TONIGHT. && .PREV DISCUSSION... (ISSUED 644 AM EDT WED OCT 18 2006) AVIATION... DENSE FOG IS WIDESPREAD THIS MORNING BUT BUFKIT HAS DRIER AIR WORKING DOWN TO THE SURFACE BETWEEN 14-16UTC. VISIBILITIES AND CEILINGS WILL IMPROVE FROM VLIFR/LIFR TO VFR BY 16Z. HIGH PRESSURE WILL BE CROSSING THE AREA TODAY AND TONIGHT SO WINDS WILL BE LIGHT AGAIN TONIGHT. MVFR FOG IS EXPECTED AT ALL TAF SITES. CLOUDS FROM THE NEXT SYSTEM APPROACHING OUT OF THE CENTRAL UNITED STATES WILL NOT REACH THE FORECAST AREA UNTIL AFTER 12UTC ON THURSDAY. PREV DISCUSSION... (ISSUED 413 AM EDT WED OCT 18 2006) SHORT TERM /TODAY THROUGH FRIDAY NIGHT/... STILL A LOT OF LOW LEVEL MOISTURE AND OBSERVATIONS SHOW VERY LITTLE SPREAD IN TEMPERATURE AND DEW POINT AS WELL AS VISIBILITIES OF ONE HALF TO ONE QUARTER MILE INTO THE VIRGINIA FOOTHILLS...ALLEGHANY HIGHLAND AND SOUTHERN SHENENDOAH VALLEY. SO HAVE EXPANDED THE DENSE FOG ADVISORY FOR THE CENTRAL PART OF THE COUNTY WARNING AREA. HAVE ALSO SLOWED DOWN THE DISSIPATION OF THE CLOUDS AND FOG. BUFKIT HAS DRIER AIR WORKING DOWN TO THE SURFACE AT 14-15UTC TO LYH AND 15-16UTC AND DAN. BROAD UPPER RIDGE OVER THE SOUTHEAST UNITES STATES WILL COVER THE COUNTY WARNING AREA THROUGH TONIGHT. TIMING OF NEXT SYSTEM ON 00UTC WRF HAS SYNOPTIC LIFT REACHING THE FORECAST AREA ON THURSDAY AFTERNOON...AND MAIN UPPER SHORT WAVE CROSSING THROUGH THE AREA ON FRIDAY MORNING. TRACK AND POSITION OF SURFACE LOW AND COLD FRONT BY FRIDAY MORNING ON THE GFS IS FAVORED AT THIS TIME. THE DEEP MOISTURE AND BEST Q-VECTOR FORCING MOVE THROUGH BY 12UTC FRIDAY. WITH VERY STRONG LOW LEVEL JET...850 MB WINDS 40-50 KNOTS .THERE MAY BE PRE-FRONTAL CONVECTION...ESPECIALLY IN THE SOUTHWEST COUNTY WARNING AREA ON THURSDAY AFTERNOON. FOR NOW WILL ADD THUNDER IN FOR THURSDAY NIGHT...MAINLY BASED ON NEW SPC DAY 2 OUTLOOK. THE SURFACE AND 850 MB FRONT WITH THIS SYSTEM WILL CROSS THROUGH THE COUNTY WARNING AREA EARLY FRIDAY MORNING...WITH STRONG COLD AIR ADVECTION BEHIND THE FRONT. 850 MB WINDS ARE 40 KNOTS BEHIND THE FRONT ON FRIDAY MORNING AND PRESSURE RISES AREA FORECAST AT 3-6MB IN 6 HOURS SO WILL BE INCREASING THE WINDS ON FRIDAY IN THE MOUNTAINS AND FOOTHILLS. COLDER AND MUCH DRIER AIRMASS COMING IN FRIDAY NIGHT AND SATURDAY. WITH PRECIPITABLE WATER DROPPING DOWN BELOW 0.5 INCHES ON FRIDAY NIGHT...WILL BE CUTTING BACK ON THE CLOUD COVER. WENT CLOSE TO MAV GUIDANCE THROUGH FRIDAY NIGHT. BUT TRENDED WARMER THAN GUIDANCE FOR BLF AND LWB WITH THE SOUTHWEST WINDS ON THURSDAY NIGHT AND SLIGHTLY COLDER THEN GUIDANCE BEHIND THE FRONT FRIDAY NIGHT. LONG TERM /SATURDAY THROUGH TUESDAY/... NO CHANGES AT THIS TIME. AVIATION... LIGHT WINDS WITH PLENTY OF MOISTURE WILL RESULT IN AREAS OF LIFR/IFR IN FOG/LOW CEILINGS THIS MORNING. AS WESTERLY DOWNSLOPE FLOW BEGINS AROUND 15Z...ANTICIPATE QUICK IMPROVEMENT ESPECIALLY EAST OF THE MOUNTAINS LATE THIS MORNING. SCATTERED TO BROKEN CU ARE POSSIBLE THIS AFTERNOON WITH SOME LOW LEVEL MOISTURE LINGERING. PATCHY RIVER VALLEY FOG WILL DEVELOP WEDNESDAY NIGHT INTO THURSDAY MORNING. MOUNTAINS OBSCURATIONS ARE POSSIBLE ESPECIALLY THIS MORNING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ WP va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 245 AM MDT THU OCT 19 2006 .DISCUSSION...A FREEZE WARNING CONTINUES THROUGH THIS MORNING. FORECAST CONCERNS INCLUDE THE AMOUNT OF WARMUP TODAY AND FRIDAY ALONG WITH TEMPERATURES AND THE RESULTING PRECIPITATION PHASE WITH THE NEXT SYSTEM DUE THROUGH THE AREA FRIDAY NIGHT AND EARLY SATURDAY. SKIES REMAIN CLEAR WITH DEWPOINTS IN THE MID TO UPPER 20S EARLY THIS MORNING WITH LIGHT SOUTHWEST WINDS RAISING TEMPERATURES SLIGHTLY ACROSS PORTIONS OF THE TRI-STATE REGION. HOWEVER...TEMPERATURES ACROSS THE FORECAST AREA HAVE ALREADY...OR ARE EXPECTED TO RETURN TO THE UPPER 20S AS WINDS SLACKEN AROUND SUNRISE. MODELS HAVE BEEN REASONABLY AGREEABLE AND CONSISTENT OVER THE PAST COUPLE OF RUNS. NORTHWEST FLOW PERSISTS THROUGH THE WEEKEND WITH SHORT WAVE RIDGING MOVING FROM THE ROCKIES TO THE HIGH PLAINS DURING THE FIRST HALF OF NEXT WEEK. HAVE USED MORE OF A GFS SOLUTION WITH A BLEND OF THE RUC WIND FIELDS AND DEWPOINTS IN THE SHORT TERM. THE GOING FORECAST WAS IN PRETTY GOOD SHAPE AND ONLY MADE MINOR CHANGES OVERALL. THE BIGGEST CHANGE WAS TO MODIFY TIMING AND COVERAGE AREAS OF THE DIFFERENT PRECIPITATION TYPES FRIDAY NIGHT AND EARLY SATURDAY AS NEAR SURFACE TEMPERATURES APPROACH AND JUST MANAGE TO REACH FREEZING IN THE NORTHWEST SECTIONS. UP TO A TENTH OF AN INCH OF MOISTURE IS EXPECTED ACROSS THE ENTIRE FORECAST AREA WITH ONLY A COUPLE TENTHS OF AN INCH OR LESS OF SNOWFALL EXPECTED OVER THE WESTERN PORTIONS OF THE COLORADO COUNTIES. HAVE KEPT THE REMAINDER OF THE FORECAST DRY WITH A GRADUAL WARMING TREND FROM THE LATTER PART OF THE WEEKEND THROUGH THE MIDDLE OF NEXT WEEK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FREEZE WARNING UNTIL 9 AM MDT /10 AM CDT/ THIS MORNING FOR KSZ001-KSZ002-KSZ003-KSZ004-KSZ013-KSZ014-KSZ015-KSZ016- KSZ027-KSZ028-KSZ029-KSZ041-KSZ042. NE...FREEZE WARNING UNTIL 9 AM MDT /10 AM CDT/ THIS MORNING FOR NEZ079-NEZ080. CO...NONE. && $$ LOCKHART ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 330 AM CDT THU OCT 19 2006 .DISCUSSION... BAND OF POST FRONTAL SHOWERS AND THUNDERSTORMS CONTINUES TO EXPAND ACROSS SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS AS OF 08Z. THIS ELEVATED CONVECTION IS LOCATED ALONG THE 850 MB TROUGH...WHICH LAGS WELL BEHIND THE SURFACE FRONT. THE SHALLOW SURFACE BOUNDARY EXTENDED FROM ABOUT OWENSBORO TO MAYFIELD KENTUCKY AT 08Z. 06Z RUC MODEL TAKES THE SURFACE FRONT QUICKLY SOUTHEAST OF THE FORECAST AREA BY 12Z...FOLLOWED BY A SURGE OF MUCH COOLER AIR. SURFACE TEMPS WERE ALREADY IN THE UPPER 40S ACROSS KMVN/KMDH AREAS AS OF 08Z...AND THE LOWER 40S WERE JUST NORTH AND WEST OF KSTL. RUC 2 METER TEMPS AND GFS MOS TEMPS SUGGEST READINGS WILL FALL INTO THE 40S ACROSS THE REMAINDER OF THE FORECAST AREA THIS MORNING. LITTLE IF ANY RISE IN TEMPS WILL OCCUR THIS AFTERNOON IN THE FACE OF BRISK NORTHERLY LOW LEVEL FLOW AND WIDESPREAD SHOWERS. ISOLATED THUNDER WILL STILL BE POSSIBLE AHEAD OF THE 850 MB TROUGH THIS AFTERNOON OVER WESTERN KY. BACK EDGE OF THE RAIN SHOULD BE WELL DEFINED THIS EVENING IN ASSOCIATION WITH THE PASSAGE OF A STRONG 500 MB VORT CENTER/SHORTWAVE TROUGH. THIS SHORTWAVE...WHICH WILL BE OVER THE TEXAS PANHANDLE AT 12Z...SHOULD DAMPEN SOMEWHAT BEFORE REACHING SE MISSOURI THIS EVENING. MODEL TIME HEIGHT CROSS SECTIONS OF RH AND VERTICAL VELOCITY INDICATE A RAPID TRANSITION TO SUBSIDENCE AND DRYING WITH THE PASSAGE OF THE SHORTWAVE. PARTIAL CLEARING SHOULD OCCUR OVER MUCH OF THE REGION LATE TONIGHT. COMBINED WITH DIMINISHING LOW LEVEL WINDS AND DRIER AIR...LOWS WILL BE IN THE 30S. SOME PATCHY FROST IS LIKELY IN NORTHERN AND WESTERN COUNTIES...WHERE SKIES CLEAR THE SOONEST. SURFACE HIGH PRESSURE RIDGE WILL MOVE EAST ACROSS THE FORECAST AREA FRIDAY MORNING...FOLLOWED BY SOUTHWEST FLOW FROM LATE AFTERNOON INTO THE NIGHT. PLENTY OF SUNSHINE WILL HELP RAISE TEMPS TO AROUND 60 DURING THE DAY. ANOTHER COLD FRONT WILL MOVE EAST/SOUTHEAST ACROSS THE LOWER OHIO VALLEY ON SATURDAY NIGHT. THIS FRONT WILL HAVE LITTLE MOISTURE TO WORK WITH...AND THE MODELS INDICATE LITTLE IF ANY INSTABILITY NEAR THE FRONT. A CHANCE OF SHOWERS EXISTS WITH THIS FRONTAL PASSAGE. SOME POST FRONTAL SHOWERS COULD LINGER INTO SUNDAY IN ASSOCIATION WITH MUCH COLDER MID LEVEL TEMPS AND LOWERING 500 MB HEIGHTS. THE MAIN STORY EARLY NEXT WEEK WILL BE A LARGE COLD 500 MB VORTEX OVER THE GREAT LAKES REGION. GFS INDICATES UNSEASONABLY COOL NORTHWEST FLOW WITH 850 MB TEMPS AROUND MINUS 6 MONDAY/TUESDAY. EVEN IF 850 MB TEMPS VERIFY TOO COLD...LOWS SHOULD BE MAINLY IN THE 30S WITH HIGHS IN THE MID TO UPPER 50S. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ MY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 423 AM EDT THU OCT 19 2006 .DISCUSSION... MAIN FCST ISSUE FOR THE NEXT FEW DAYS IS PCPN POTENTIAL WHICH WILL FREQUENTLY REVOLVE AROUND LAKE EFFECT PCPN. WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF DOMINATING CNTRL CANADA INTO THE CNTRL/WRN CONUS WITH INDICATIONS OF A VORTEX REDEVELOPING OVER NRN MANITOBA/NW ONTARIO. SHORTWAVE LIFTING NE WITHIN THE POSITIVELY TILTED TROF OVER THE CNTRL CONUS INTO THE GREAT LAKES BROUGHT SOME -RA TO MAINLY THE SE 2/3RDS OF THE FCST AREA LAST EVENING. TO THE W...A SHORTWAVE IS DIVING SE ACROSS ALBERTA/SASKATCHEWAN/MT. THIS WILL BE A FEATURE OF INTEREST FRI. FARTHER TO THE NW...AN IMPRESSIVE LOOKING SHORTWAVE OVER THE NE GULF OF ALASKA WAS APPROACHING NRN BRITISH COLUMBIA. EVOLUTION OF THIS SYSTEM WILL BE A FCST ISSUE LATE IN THE WEEKEND AS IT MOVES THRU THE LONGWAVE TROF POSITION FROM HUDSON BAY S ACROSS THE CNTRL CONUS. LAKE EFFECT PCPN HAS BEEN TAKING SHAPE OVERNIGHT...MAINLY OVER ERN LAKE SUPERIOR...AS AIRMASS CONTINUES TO COOL WITH CAA FROM THE NW. 00Z KINL/CWPL SOUNDINGS SHOWED 850MB TEMPS OF -7C...SUFFICIENT FOR LAKE EFFECT PCPN WITH LAKE SUPERIOR SFC WATER TEMPS GENERALLY 8-9C. KINL SOUNDING INDICATED INVERSION BASE AT 5.4KFT WHILE IT WAS BASED AT 4.6KFT AT CWPL. AIRMASS BLO INVERSION WAS MOIST...FURTHER SUPPORTING LAKE EFFECT PCPN DEVELOPMENT. EXPECT LAKE EFFECT -SHRA/-SHSN/SPRINKLES/FLURRIES TO CONTINUE THIS MORNING FOR NW FLOW AFFECTED AREAS DUE TO FAVORABLE INSTABILITY. PCPN WILL BE FURTHER SUPPORTED BY MOIST SUB INVERSION PROFILE ALREADY PRESENT IN THE AIRMASS BEFORE PASSING OVER THE LAKE. HOWEVER...PCPN WILL REMAIN QUITE LIGHT DUE TO POOR SNOW GROWTH MICROPHYSICS AS TEMPS WITHIN MOIST LAYER ARE GENERALLY ABOVE -10C. DID NOT MENTION ANY SNOW OVER THE ERN PART OF THE FCST AREA AS FCST SOUNDINGS SHOW SFC-BASED ABOVE FREEZING LAYER WELL OVER 1KFT DEEP. THIS AFTN...FLOW BECOMES INCREASINGLY ANTICYCLONIC WITH SFC RIDGE BUILDING INTO THE UPPER GREAT LAKES REGION. INCREASINGLY ANTICYCLONIC FLOW COMBINED WITH DAYTIME HEATING DISRUPTING HEAT/MOISTURE FLUXES OFF THE LAKE AND ADVECTION OF DRIER AIR FROM THE W PER FCST SOUNDINGS WILL SPELL THE DEMISE OF LAKE EFFECT PCPN FROM W TO E LATE MORNING THRU MID AFTN. AWAY FROM LAKE EFFECT PCPN...MIGHT BE A FEW SPRINKLES/FLURRIES EARLY THIS MORNING...BUT OTHERWISE ANTICIPATE SOLID CLOUD DECK WILL BREAK UP THROUGH THE DAY WITH ANTICYCLONIC FLOW AND ADVECTION OF DRIER AIR. ANY LINGERING STRATOCU SHOULD DEPART EARLY THIS EVENING IN CONJUNCTION WITH LOW-LEVEL RIDGE AXIS...BUT AT THE SAME TIME THERE WILL PROBABLY BE SOME INCREASE IN HIGH CLOUDS ASSOCIATED WITH SHORTWAVE NOW OVER THE NRN ROCKIES WHICH WILL BE HEADING TO THE MID MISSISSIPPI VALLEY. STILL...THERE WILL BE A WINDOW OF OPPORTUNITY FOR GOOD RADIATIONAL COOLING TONIGHT WITH LIGHT/CALM WINDS. WILL THUS FAVOR LOW END OF MOS GUIDANCE TONIGHT. ALTHOUGH FORCING WITH SHORTWAVE REACHING THE MISSISSIPPI VALLEY TONIGHT WILL PASS WELL S AND SE OF HERE FRI...MODELS STILL INDICATE A WEAKER SHORTWAVE TRACKING INTO THE UPPER LAKES WITH A WEAK SFC LOW REFLECTION. IN THIS REGARD...THE GFS HAS COME AROUND TOWARD THE NAM SOLUTION. LOW-LEVEL CONVERGENCE NEAR LOW AND WEAK MOIST ISENTROPIC ASCENT VIEWED ON 290K SFC (AROUND 700MB) SHOULD BE SUFFICIENT TO WARRANT LOW END CHC POPS FOR -SHRA SPREADING W TO E FRI AFTN/EVENING. AS SFC LOW TRACKS E FRI NIGHT...CAA GETS UNDERWAY WITH 850MB TEMPS DROPPING TO AROUND -8C PER PREFERRED COOLER GFS SOLUTION. SO...EXPECT LIGHT LAKE EFFECT -SHRA/-SHSN TO DEVELOP OVER THE W DURING THE NIGHT. LAKE EFFECT PCPN SHOULD THEN DEVELOP INTO THE ERN FCST AREA SAT AS CAA CONTINUES AROUND SOUTHERN SIDE OF VORTEX WHICH WILL BE WELL ESTABLISHED AGAIN OVER ONTARIO BY THAT TIME (850MB TEMPS SHOULD BE AROUND -8C ACROSS MOST OF LAKE SUPERIOR BY SAT AFTN). AWAY FROM LAKE EFFECT PCPN...HAVE KEPT GOING CHC POPS AS DEEPER MOISTURE ROTATES INTO THE UPPER LAKES. SHORTWAVE CURRENTLY APPROACHING NRN BRITISH COLUMBIA WILL REACH THE SRN PLAINS SAT AND WILL MOVE NE INTO THE GREAT LAKES SUN. MODEL CONSENSUS CONTINUES TO INDICATE THIS SYSTEM WILL PASS SE OF THE FCST AREA AND HAVE LITTLE IMPACT ON SENSIBLE WEATHER HERE. EVEN SO...IT WILL REMAIN UNSETTLED ACROSS THE UPPER LAKES WITH MID/UPPER TROF/DEEP CYCLONIC FLOW DOMINATING THE AREA. LAKE EFFECT PCPN SHOULD BECOME FAIRLY WIDESPREAD NEAR LAKE SUPERIOR EVEN THOUGH INSTABILITY WILL NOT BE SIGNIFICANT (850MB TEMPS -7/-8C). && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 344 AM CDT THU OCT 19 2006 .DISCUSSION... SHORT TERM FORECAST PROBLEM IS THE LOW CLOUD DECK OVER THE CWA. WESTERN EDGE HAD BEEN MOVING ALONG AT A FAIRLY GOOD PACE BUT HAS SLOWED SOME IN THE PAST HOUR OR SO. THERE ARE SOME HOLES SHOWING UP IN A FEW SPOTS EAST OF THE WESTERN EDGE. 06Z RUC 850 MB RH FIELD HAS BEST FIT TO THE PATTERN AND THIS EDGE DOES NOT REACH WI BORDER UNTIL ABOUT NOON. IT MAY CLEAR FASTER THAN THAT ONCE UPPER TROUGH AS SEEN IN WV IMAGERY MOVES EAST AND STRONGER SUBSDNC MOVES IN FOR A TIME. OTHERWISE NEXT SHORT WAVE IN NW FLOW WILL AFFECT AREA TONIGHT. NOT MUCH SATURATION SEEN ON EITHER NAM OR GFS UNTIL EVENING SO WILL BACK OFF ON POPS DURING DAYLIGHT HOURS. WILL SPREAD SOME LOW POPS FARTHER SOUTH INITIALLY THIS EVENING WITH STEEPER LAPSE RATES SUGGESTED...THEN KEEP MOSTLY IN N AND E CWA LATER TONIGHT CLOSER TO MORE SIG QG CONV. STRONGER WAVE IN WNW FLOW HANDLED IN SIMILAR MANNER BY VARIOUS MODELS AND TREND IS MAINLY AFFECTING AREAS JUST TO OUR SOUTH. GUID POPS SEEM A LITTLE LOW GIVEN THE CLOSE PROXIMITY OF FORCING. WILL BACK OFF SOME ON POPS BUT KEEP A MID RANGE VALUE GOING ALONG SOUTHER TIER OF COUNTIES. GFS MIN TEMPS SEEM A LITTLE LOW FRIDAY NIGHT AND A LITTLE HIGH ON FRIDAY. LONGER TERM...SUNDAY THROUGH THURSDAY 00Z GFS AND ECMWF ARE IN FAIR AGREEMENT WITH HIGHLY AMPLIFIED FLOW PATTER WITH POLAR VORTEX ROTATING THROUGH GREAT LAKES REGION EARLY IN PERIOD. 85H TEMPERATURE ANOMALIES STILL INDICATING COLDEST PERIOD TO BE SUN AND MON...WITH MODERATION THEREAFTER AS LOW MOVES EAST. MOVEMENT OF POLAR VORTEX ALWAYS IN QUESTION...BUT SOME MODERATION EXPECTED MID/LATE NEXT WEEK. PRECIPITATION PROBABILITIES APPEAR LOW AT THIS TIME...AFFECTING MAINLY EASTERN CWA SUNDAY AND POSSIBLY INTO MONDAY AS UPPER TROUGH PROGGED TO MOVE ACROSS WESTERN GREAT LAKES THEN. DRY TREND SHOULD ENSUE THROUGH MIDWEEK AS LARGE SURFACE HIGH MOVES THROUGH UPPER MIDWEST REGION. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPR/DWE mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 1230 AM CDT THU OCT 19 2006 .AVIATION... POST FRONTAL STRATUS DECK CONTINUES TO BREAK UP SOME ACROSS THE BIG COUNTRY TONIGHT. EXPECT OVC CONDITIONS TO CONTINUE FARTHER SOUTH BUT COULD SEE WIDESPREAD OVC CONDITIONS TO FILL BACK IN LATER TONIGHT AS A STRONG SHORTWAVE TROUGH PUSHES ACROSS W TX. WILL HAVE TO KEEP AN EYE ON AN RA FOR THE KABI AREA WITH THIS SYSTEM. RIGHT NOW LOOKS LIKE OVC SKIES WILL BE ABOVE MVFR RULES IF THEY FILL BACK IN. FARTHER SOUTH TOWARDS KSJT AND KJCT LOOK FOR CEILINGS TO SLOWLY RISE THROUGH THE MORNING. SKIES SHOULD SCATTER OUT AT BOTH TAF SITES LATER THIS AFTERNOON AFTER 18Z. NORTHERLY WINDS SHOULD CONTINUE THROUGH MUCH THE NEXT 24 HRS ALTHOUGH WINDS SHOULD DIMINISH THIS EVENING AS HIGH PRESSURE BUILDS INTO N TX. 10 && PREV DISCUSSION... (ISSUED 857 PM CDT WED OCT 18 2006) UPDATE... SEVERE STORM THREAT CONTINUES TO DIMINISH AND HAVE DROPPED THE LAST FEW COUNTIES FROM THE WATCH. HAVE ALSO TWEAKED POPS DOWN ACROSS THE SOUTHEAST COUNTIES...ALTHOUGH WITH UPPER SYSTEM APPROACHING FROM THE WEST...WILL LEAVE SMALL POPS IN FOR LATER TONIGHT AND INTO THURSDAY MORNING. PREV DISCUSSION... (ISSUED 744 PM CDT WED OCT 18 2006) UPDATE... HAVE CLEARED A FEW COUNTIES FROM THE SEVERE THUNDERSTORM WATCH. COLD FRONT HAVE PUSHED SOUTH OF THE AREA THIS EVENING...AND CONTINUES TO PUSH SOUTH AT A DECENT PACE. CAN NOT RULE OUT A STRAY ELEVATED STORM WITH SOME HAIL BACK INTO THE EXTREME SOUTH AND SOUTHEAST PORTIONS OF THE AREA...BUT AREAS LIKE BROWNWOOD AND BRADY NOW LOOK LIKE THEY ARE WELL BACK INTO THE COOLER AIR. HAVE ALSO MADE A FEW ADJUSTMENTS FOR CURRENT CONDITIONS...BUT HAVE LEFT MOST OF THE FORECAST GRIDS ALONE FOR NOW. WILL START TWEAKING THESE AS WELL...BUT MORE ON THAT LATER. PREV DISCUSSION... (ISSUED 200 PM CDT WED OCT 18 2006) SHORT TERM... THERE IS A POTENT UPPER LEVEL LOW NEAR THE SOUTHWEST EXTENT OF A TROUGH THAT EXTENDS FROM THE NORTHERN U.S. PLAINS TO THE NORTHERN BAJA PENINSULA CURRENTLY OVER NORTH CENTRAL AZ TODAY...WHICH IS BEGINNING TO MAKE ITS TURN TO THE EAST TOWARD WEST CENTRAL TEXAS. DRY SOUTHWEST FLOW IS CURRENTLY OVER THE AREA TODAY WITH A COLD FRONT HURTLING THROUGH THE CWA TODAY AT THE SURFACE BRINGING LOW CLOUDS AND COLDER TEMPERATURES INTO THE AREA. ALTHOUGH THE 250MB WINDS ALONG THE EAST SIDE OF THE UPPER LEVEL TROUGH ARE STRONG...700MB WINDS ARE 20-30 KT. THIS IS ALLOWING THE FRONT TO MAKE ITS ADVANCE TO THE SOUTH DURING THE DAY TODAY...ALTHOUGH CAN SEE THAT THE LOW CLOUDS HAVE SLOWED THEIR ADVANCE. CAN SEE CUMULUS BEGINNING TO BUILD OVER OUR SOUTHERN AND EASTERN COUNTIES. SOUTH OF THE FRONT...MOIST AND UNSTABLE AIR REMAINS IN PLACE. THE FRONT MAY INTERACT WITH THIS UNSTABLE AIR AND RESULT IN A FOCUS FOR THUNDERSTORMS TO DEVELOP OVER THE NORTHWEST HILL COUNTRY AND SOUTHERN HEARTLAND AREAS LATER THIS AFTERNOON. HOWEVER...WITH THE CURRENT SPEED OF THE FRONT...THE SOUTHERN HEARTLAND AREA MAY BE NORTH OF THE FRONT BY LATE THIS AFTERNOON. THIS WOULD KEEP SFC BASED INITIATION OF CONVECTION TO THE SOUTH OF THIS AREA FOR TONIGHT. THE SOUTHERN HEARTLAND COULD STILL BE AFFECTED AS THE STORMS MOVE NORTHEAST. WITH THE APPROACHING UPPER LEVEL SHORTWAVE BRINGING IN MORE LIFT COMBINING WITH THE FRONT...WILL KEEP THE GOOD TO LIKELY CHANCE FOR THUNDERSTORMS OVER THE SOUTHEASTERN COUNTIES...AND AT LEAST A SLIGHT CHANCE FOR MOST OTHER AREAS. HAVE ONLY ISOLATED SHRA FOR SOUTHWESTERN AREAS AS THEY SHOULD BE FARTHEST FROM BOTH THE LOW LEVEL MOISTURE AND UPPER LEVEL FORCING. AS FAR AS THE SEVERE THREAT...AIR IS QUITE UNSTABLE OVER THE NORTHWEST HILL COUNTRY WITH LI/S DOWN TO -7 ON 18Z ANALYSIS. KDRT DID SHOW AN INVERSION NEAR 700MB...AND WV SHOWS FAIRLY DRY AIR ALOFT. BUT RUC80 0-6KMB BULK SHEAR VALUES OF 40-50KTS...AND THIS COMBINED WITH INSTABILITY AND THE APPROACHING FRONT DEFINITELY ARGUE FOR LEAVING THE MENTION OF SEVERE IN THE FORECAST TONIGHT. HAVE KEPT LOW TEMPERATURES SIMILAR TO WHAT WAS INHERITED WITH FAIRLY COOL READINGS EXPECTED OVERNIGHT IN THE UPPER 40S TO LOWER 50S ACROSS THE AREA. LONG TERM... ON THURSDAY...THERE MAY BE SOME LINGERING SHRA/TSRA FOR THE EXTREME EASTERN AND SOUTHEASTERN AREAS DURING THE MORNING HOURS...BUT THE UPPER LEVEL WAVE WILL BE QUICKLY MOVING OUT OF THE FORECAST AREA BRINGING IN DRY...SINKING AIR. HAVE KEPT SOME CLOUDS AROUND DURING THE MORNING AS WELL FOR MOST OF THE AREA...BUT EXPECT CLOUDCOVER TO SHARPLY DECREASE FROM WEST TO EAST AS THE SYSTEM MOVES OUT OF THE REGION. HAVE WARMED TOMORROW/S HIGHS A COUPLE DEGREES SINCE WE ARE EXPECTING SOME SUNSHINE TOMORROW AND THAT SHOULD ALLOW TEMPERATURES TO CLIMB BACK INTO THE MID 60S AT LEAST OVER MOST OF THE AREA. NORTHWEST FLOW TOMORROW TRANSITIONS INTO ZONAL FLOW FOR FRIDAY INTO SATURDAY MORNING AHEAD OF THE NEXT TROUGH. THIS WILL ALLOW FOR TEMPERATURES TO WARM NICELY BACK INTO THE 70S TO NEAR 80 BEFORE THE NEXT FRONT MOVES THROUGH SATURDAY/SATURDAY NIGHT. TIMING FOR THIS FRONT REMAINS UNCERTAIN...BUT COULD BE SIMILAR TO TODAY WITH THE FRONT MOVING THROUGH DURING THE DAY. AT THIS TIME...IT APPEARS LATER...MOVING INTO THE BIG COUNTRY BY EVENING...AND THROUGH THE REST OF THE CWA SATURDAY NIGHT. BUT THE FRONT COULD SPEED UP BETWEEN NOW AND SATURDAY...AND ACTUALLY ARRIVE A BIT EARLIER. WILL KEEP WATCHING THIS AS WE MOVE CLOSER TO SATURDAY. REGARDLESS...RIGHT NOW IT LOOKS LIKE SUNDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN THE 60S...WITH TEMPERATURES REBOUNDING DURING THE FIRST HALF OF NEXT WEEK. HAVE OPTED TO KEEP POPS OUT OF THE FORECAST FOR THE NEXT FRONT. WITH THE STRENGTH OF THIS FRONT...RICH LOW LEVEL MOISTURE WILL BE PUSHED WELL SOUTH OF THE REGION...LIMITING THE RETURN AND CHANCE FOR PRECIP WITH SATURDAY/S FRONT. SJT WATCHES/WARNINGS/ADVISORIES... NONE. && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 10 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 848 AM MDT THU OCT 19 2006 .UPDATE...AN UPDATE WILL BE ISSUED SHORTLY TO REMOVE THE FREEZE WARNING HEADLINE AS WELL AS INCREASE CLOUD COVER BASED ON LATEST SATELLITE TRENDS AS THE EXIT REGION OF H3 90KT JET DIVES SOUTHEAST ACROSS THE AREA. THE CLOUDS MAY LIMIT HEATING EVEN WITH LOW LEVEL DOWNSLOPE FLOW. INCREASING SUBSIDENCE LATE IN THE PERIOD SUPPORTS SOME BREAKS IN THE CLOUDS SO ONLY ADJUSTED MAXIMUM TEMPERATURES DOWN SLIGHTLY WHERE HIGHEST CONFIDENCE WAS. EXPECT HIGHS TO RANGE FROM THE MID 50S WEST/NORTHWEST TO AROUND 60/LOWER 60S SOUTHEAST. MCGUIRE && .PREV DISCUSSION... (ISSUED 245 AM MDT THU OCT 19 2006) DISCUSSION...A FREEZE WARNING CONTINUES THROUGH THIS MORNING. FORECAST CONCERNS INCLUDE THE AMOUNT OF WARMUP TODAY AND FRIDAY ALONG WITH TEMPERATURES AND THE RESULTING PRECIPITATION PHASE WITH THE NEXT SYSTEM DUE THROUGH THE AREA FRIDAY NIGHT AND EARLY SATURDAY. SKIES REMAIN CLEAR WITH DEWPOINTS IN THE MID TO UPPER 20S EARLY THIS MORNING WITH LIGHT SOUTHWEST WINDS RAISING TEMPERATURES SLIGHTLY ACROSS PORTIONS OF THE TRI-STATE REGION. HOWEVER...TEMPERATURES ACROSS THE FORECAST AREA HAVE ALREADY...OR ARE EXPECTED TO RETURN TO THE UPPER 20S AS WINDS SLACKEN AROUND SUNRISE. MODELS HAVE BEEN REASONABLY AGREEABLE AND CONSISTENT OVER THE PAST COUPLE OF RUNS. NORTHWEST FLOW PERSISTS THROUGH THE WEEKEND WITH SHORT WAVE RIDGING MOVING FROM THE ROCKIES TO THE HIGH PLAINS DURING THE FIRST HALF OF NEXT WEEK. HAVE USED MORE OF A GFS SOLUTION WITH A BLEND OF THE RUC WIND FIELDS AND DEWPOINTS IN THE SHORT TERM. THE GOING FORECAST WAS IN PRETTY GOOD SHAPE AND ONLY MADE MINOR CHANGES OVERALL. THE BIGGEST CHANGE WAS TO MODIFY TIMING AND COVERAGE AREAS OF THE DIFFERENT PRECIPITATION TYPES FRIDAY NIGHT AND EARLY SATURDAY AS NEAR SURFACE TEMPERATURES APPROACH AND JUST MANAGE TO REACH FREEZING IN THE NORTHWEST SECTIONS. UP TO A TENTH OF AN INCH OF MOISTURE IS EXPECTED ACROSS THE ENTIRE FORECAST AREA WITH ONLY A COUPLE TENTHS OF AN INCH OR LESS OF SNOWFALL EXPECTED OVER THE WESTERN PORTIONS OF THE COLORADO COUNTIES. HAVE KEPT THE REMAINDER OF THE FORECAST DRY WITH A GRADUAL WARMING TREND FROM THE LATTER PART OF THE WEEKEND THROUGH THE MIDDLE OF NEXT WEEK. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1020 AM EDT THU OCT 19 2006 .UPDATE... OVERALL...GOING FCST IN GOOD SHAPE. ADDED SCT SNOW SHOWERS INTO GRIDS IN FAR W CWA VCNTY OF KIWD. VSBY ON AWOS SINCE 1235Z SHOWING AROUND 3SM WITH REPORT OF SNOW ATTM FM THAT AREA. WIND AT KIWD IS MORE SW WHILE WINDS OVR W LK SUPERIOR SHOW MORE NW DIRECTION. CONVERGENCE MAY BE ENHANCING THE SNOW SOMEWHAT. OTHERWISE... SHORTWAVE TROF IS IN PROCESS OF CROSSING UPR MI. BEST CHANCE FOR MEASURABLE PCPN WILL CONTINUE OVR E SECTIONS AS NW WINDS FLOW OVER LK SUPERIOR. MORNING KSAW TAMDAR AND RAOB FM GRB SHOWED MOIST LAYER TO AROUND 800MB WITH H85 TEMPS NEAR -5C. PCPN SHOULD PERSIST AS H85 TEMPS SLIGHTLY FALL THIS AFTN AND MOISTURE IS SLOW TO DEPART. DID KEEP IDEA OF ENDING PCPN OVR W HALF THIS AFTN ONCE SHORTWAVE TROF PASSES BY AND THERE IS HINT OF SOME SHORTWAVE RIDGING UPSTREAM OVR MN. PUBLISHED GRIDS OUT AND TEXT ZFPMQT UPDATE WILL BE OUT SHORTLY. && .DISCUSSION... MAIN FCST ISSUE FOR THE NEXT FEW DAYS IS PCPN POTENTIAL WHICH WILL FREQUENTLY REVOLVE AROUND LAKE EFFECT PCPN. WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF DOMINATING CNTRL CANADA INTO THE CNTRL/WRN CONUS WITH INDICATIONS OF A VORTEX REDEVELOPING OVER NRN MANITOBA/NW ONTARIO. SHORTWAVE LIFTING NE WITHIN THE POSITIVELY TILTED TROF OVER THE CNTRL CONUS INTO THE GREAT LAKES BROUGHT SOME -RA TO MAINLY THE SE 2/3RDS OF THE FCST AREA LAST EVENING. TO THE W...A SHORTWAVE IS DIVING SE ACROSS ALBERTA/SASKATCHEWAN/MT. THIS WILL BE A FEATURE OF INTEREST FRI. FARTHER TO THE NW...AN IMPRESSIVE LOOKING SHORTWAVE OVER THE NE GULF OF ALASKA WAS APPROACHING NRN BRITISH COLUMBIA. EVOLUTION OF THIS SYSTEM WILL BE A FCST ISSUE LATE IN THE WEEKEND AS IT MOVES THRU THE LONGWAVE TROF POSITION FROM HUDSON BAY S ACROSS THE CNTRL CONUS. LAKE EFFECT PCPN HAS BEEN TAKING SHAPE OVERNIGHT...MAINLY OVER ERN LAKE SUPERIOR...AS AIRMASS CONTINUES TO COOL WITH CAA FROM THE NW. 00Z KINL/CWPL SOUNDINGS SHOWED 850MB TEMPS OF -7C...SUFFICIENT FOR LAKE EFFECT PCPN WITH LAKE SUPERIOR SFC WATER TEMPS GENERALLY 8-9C. KINL SOUNDING INDICATED INVERSION BASE AT 5.4KFT WHILE IT WAS BASED AT 4.6KFT AT CWPL. AIRMASS BLO INVERSION WAS MOIST...FURTHER SUPPORTING LAKE EFFECT PCPN DEVELOPMENT. EXPECT LAKE EFFECT -SHRA/-SHSN/SPRINKLES/FLURRIES TO CONTINUE THIS MORNING FOR NW FLOW AFFECTED AREAS DUE TO FAVORABLE INSTABILITY. PCPN WILL BE FURTHER SUPPORTED BY MOIST SUB INVERSION PROFILE ALREADY PRESENT IN THE AIRMASS BEFORE PASSING OVER THE LAKE. HOWEVER...PCPN WILL REMAIN QUITE LIGHT DUE TO POOR SNOW GROWTH MICROPHYSICS AS TEMPS WITHIN MOIST LAYER ARE GENERALLY ABOVE -10C. DID NOT MENTION ANY SNOW OVER THE ERN PART OF THE FCST AREA AS FCST SOUNDINGS SHOW SFC-BASED ABOVE FREEZING LAYER WELL OVER 1KFT DEEP. THIS AFTN...FLOW BECOMES INCREASINGLY ANTICYCLONIC WITH SFC RIDGE BUILDING INTO THE UPPER GREAT LAKES REGION. INCREASINGLY ANTICYCLONIC FLOW COMBINED WITH DAYTIME HEATING DISRUPTING HEAT/MOISTURE FLUXES OFF THE LAKE AND ADVECTION OF DRIER AIR FROM THE W PER FCST SOUNDINGS WILL SPELL THE DEMISE OF LAKE EFFECT PCPN FROM W TO E LATE MORNING THRU MID AFTN. AWAY FROM LAKE EFFECT PCPN...MIGHT BE A FEW SPRINKLES/FLURRIES EARLY THIS MORNING...BUT OTHERWISE ANTICIPATE SOLID CLOUD DECK WILL BREAK UP THROUGH THE DAY WITH ANTICYCLONIC FLOW AND ADVECTION OF DRIER AIR. ANY LINGERING STRATOCU SHOULD DEPART EARLY THIS EVENING IN CONJUNCTION WITH LOW-LEVEL RIDGE AXIS...BUT AT THE SAME TIME THERE WILL PROBABLY BE SOME INCREASE IN HIGH CLOUDS ASSOCIATED WITH SHORTWAVE NOW OVER THE NRN ROCKIES WHICH WILL BE HEADING TO THE MID MISSISSIPPI VALLEY. STILL...THERE WILL BE A WINDOW OF OPPORTUNITY FOR GOOD RADIATIONAL COOLING TONIGHT WITH LIGHT/CALM WINDS. WILL THUS FAVOR LOW END OF MOS GUIDANCE TONIGHT. ALTHOUGH FORCING WITH SHORTWAVE REACHING THE MISSISSIPPI VALLEY TONIGHT WILL PASS WELL S AND SE OF HERE FRI...MODELS STILL INDICATE A WEAKER SHORTWAVE TRACKING INTO THE UPPER LAKES WITH A WEAK SFC LOW REFLECTION. IN THIS REGARD...THE GFS HAS COME AROUND TOWARD THE NAM SOLUTION. LOW-LEVEL CONVERGENCE NEAR LOW AND WEAK MOIST ISENTROPIC ASCENT VIEWED ON 290K SFC (AROUND 700MB) SHOULD BE SUFFICIENT TO WARRANT LOW END CHC POPS FOR -SHRA SPREADING W TO E FRI AFTN/EVENING. AS SFC LOW TRACKS E FRI NIGHT...CAA GETS UNDERWAY WITH 850MB TEMPS DROPPING TO AROUND -8C PER PREFERRED COOLER GFS SOLUTION. SO...EXPECT LIGHT LAKE EFFECT -SHRA/-SHSN TO DEVELOP OVER THE W DURING THE NIGHT. LAKE EFFECT PCPN SHOULD THEN DEVELOP INTO THE ERN FCST AREA SAT AS CAA CONTINUES AROUND SOUTHERN SIDE OF VORTEX WHICH WILL BE WELL ESTABLISHED AGAIN OVER ONTARIO BY THAT TIME (850MB TEMPS SHOULD BE AROUND -8C ACROSS MOST OF LAKE SUPERIOR BY SAT AFTN). AWAY FROM LAKE EFFECT PCPN...HAVE KEPT GOING CHC POPS AS DEEPER MOISTURE ROTATES INTO THE UPPER LAKES. SHORTWAVE CURRENTLY APPROACHING NRN BRITISH COLUMBIA WILL REACH THE SRN PLAINS SAT AND WILL MOVE NE INTO THE GREAT LAKES SUN. MODEL CONSENSUS CONTINUES TO INDICATE THIS SYSTEM WILL PASS SE OF THE FCST AREA AND HAVE LITTLE IMPACT ON SENSIBLE WEATHER HERE. EVEN SO...IT WILL REMAIN UNSETTLED ACROSS THE UPPER LAKES WITH MID/UPPER TROF/DEEP CYCLONIC FLOW DOMINATING THE AREA. LAKE EFFECT PCPN SHOULD BECOME FAIRLY WIDESPREAD NEAR LAKE SUPERIOR EVEN THOUGH INSTABILITY WILL NOT BE SIGNIFICANT (850MB TEMPS -7/-8C). && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...JLA DISCUSSION...ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 1134 AM EDT THU OCT 19 2006 .SHORT TERM /REST OF TODAY/... WILL ISSUE UPDATE...MAINLY TO ACCOUNT FOR ISSUANCE OF FLOOD WATCH ACROSS NORTHERN COUNTIES...AND TO ADD HEAVY RAIN MENTION IN DATABASE/DATABASE PRODUCTS FOR TONIGHT/FRI. BASED ON ANTECEDENT CONDITIONS...WHICH INCLUDE HIGH RIVER LEVELS FROM TUESDAY NIGHT/S 1 TO 3 INCHES OF RAIN...IN ADDITION TO THE PROSPECTS OF AN ADDITIONAL 2 TO 3 INCHES OF RAINFALL ACROSS NORTHERN AREAS...WE HAVE ISSUED THE FLOOD WATCH FOR NORTHERN COUNTIES EFFECTIVE FROM 6 AM EDT/FRI TO 6 AM EDT/SAT. OTHERWISE...IN THE NEAR-TERM...HAVE BACKED OFF A BIT ON PRECIP ONSET FROM THE CAPITAL DISTRICT SOUTHWARD...WHICH MAY NOT OCCUR UNTIL LATER THIS EVE. ACROSS THE SOUTHERN ADIRONDACKS...SOME SHOWERS ARE ALREADY GRAZING EXTREME NORTHERN HERKIMER COUNTY...WITH ADDITIONAL SHOWERS DEVELOPING UPSTREAM. THUS...DO EXPECT AT LEAST SOME SHOWERS ACROSS THE ADIRONDACKS BY MID-LATE AFTERNOON...AS SHALLOW FRONTAL BOUNDARY GRADUALLY SAGS SE. AS FOR SKY CONDITIONS...SOME BREAKS IN THE LOW LEVEL CLOUDS WERE DEVELOPING JUST S OF THE CAPITAL DISTRICT...WITH LATEST RUC INDICATING POTENTIAL FOR ADDITIONAL BREAKS TO DEVELOP ACROSS THE LOWER MID HUDSON VALLEY. THUS...KEPT EXPECTED MAX TEMPS SIMILAR TO PREVIOUS FORECAST ISSUANCE...WHICH GENERALLY RANGE FROM THE LOWER/MID 60S ACROSS THE CAPITAL DISTRICT...TO UPPER 60S TO THE S. && .PREV DISCUSSION... /ISSUED 315 AM EDT THU OCT 19 2006/ SYNOPSIS...A COLD FRONT, OVER EXTREME WESTERN NEW YORK, WILL SLOWLY HEAD EAST, AND STALL OVER THE LISTENING AREA BY LATE TODAY. AN AREA OF LOW PRESSURE WILL FORM ALONG THIS BOUNDARY TO OUR SOUTH, THEN TRACK UP ALONG THE FRONT, JUST TO OUR EAST, ON FRIDAY. THIS SCENARIO WILL BRING ANOTHER ROUND OF RAIN TONIGHT, LASTING INTO FRIDAY EVENING. ENOUGH COLD AIR AT THE END MIGHT ALLOW THE RAIN TO SWITCH BRIEFLY TO SNOW WELL TO THE NORTH AND WEST OF ALBANY BEFORE ENDING. SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...CLOUDS HAVE HUNG IN TOUGH ACROSS OUR REGION OVERNIGHT...KEEPING TEMPERATURES FROM FALLING OUT OF THE 50S. THESE CLOUDS LOOK TO LINGER INTO TODAY...AND BY THE TIME THEY WERE TO BURN OFF, MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH THE FRONT, WILL LIKELY BE OVERHEAD. WITH PERSISTENT CLOUDS, WILL CONTINUE THE IDEA OF GOING LOWER THAN MAV NOS, BUT NOT BY MUCH, AS IT HAS APPARENTLY CAUGHT ON TO THE TREND. WILL KEEP A LOT OF CONTINUITY FROM THE PREVIOUS PACKAGE. THE FRONT STILL LOOKS TO BECOME ANA AS IT COMES INTO OUR AREA (AS WINDS ALOFT ALIGN WITH IT). WE DO NOT EXPECT MUCH SHOWER ACTIVITY UNTIL LATER IN THE DAY, AND PROBABLY NOT UNTIL NEAR DARK FROM THE HUDSON VALLEY AND POINTS EASTWARD. TONIGHT, THE SHORT WAVE, NOW FOUND JUST NORTH OF TEXAS, WILL INITIATE CYCLOGENESIS AS IT INTERACTS WITH THE INCREASINGLY BAROCLINIC ZONE. A PRETTY POTENT LOW PRESSURE WILL TRACK ALONG THE FRONT, NEAR THE I-95 CORRIDOR. THE BEST FRONTOGENTIC FORCING LOOKS TO BE ACROSS OUR NORTHEASTERN AREAS. NEVERTHELESS PW VALUES OF 1.5 INCHES OR MORE, WILL ISENTROPICALLY LIFT ACROSS THE ENTIRE REGION BRINGING THE POTENTIAL FOR AN INCH OR BETTER OF RAINFALL. THE AIR MIGHT BE STILL BE COLD ENOUGH FOR A BRIEF SWITCH OVER TO SNOW ACROSS MAINLY OUR ADIRONDACKS LATER FRIDAY, BUT ANY ACCUMULATIONS FROM THIS VANTAGE POINT LOOK FAIRLY LIGHT. MORE ABOUT THE RAINFALL CAN BE FOUND IN OUR HYDROLOGY SECTION. BOTH MODELS WIND THE STORM UP QUITE A BIT AS IT REACHES THE GULF OF MAINE LATE FRIDAY (THE NAM IS A BIT DEEPER). EXPECT GUSTY NW WINDS TO PERK UP AND BUFFET THE REGION BY FRIDAY NIGHT, WHICH WILL HELP PLUCK THE INCREASINGLY COLORFUL LEAFS RIGHT OFF THE TREES. AT THIS POINT, THE WIND LOOKS TO REMAIN BELOW ADVISORY/WARNING CRITERIA, BUT THE DAY CREW NEEDS TO REEXAMINE THE WINDS. ONE CHANGE WAS TO ADD A CHANCE OF THUNDER TO ALL OUR ZONES FRIDAY MORNING. WHILE SBCAPES ARE MARGINAL AT BEST...STRONG DYNAMICS AND LOW LEVEL SHEAR COULD PRODUCE LOW TOP STORMS, ESPECIALLY S AND E OF ALBANY. THERE IS EVEN AN OUTSIDE CHANCE THAT ONE OR TWO OF THESE STORMS COULD BECOME BRIEFLY SEVERE, BUT NOT ENOUGH OF A THREAT TO HIGHLIGHT AT THIS TIME. HOWEVER, WILL MENTION IN OUR HAZARDOUS WEATHER OUTLOOK (HWO). BY AFTERNOON, THE WARM AIR SECTOR SHOULD HAVE PUSH FURTHER EAST WITH ANY THREAT OF THUNDER ENDING AS COLDER AIR BEGINS WORKING IN. TEMPERATURES MIGHT ACTUALLY FALL IN SOME PLACES DURING THE DAY ON FRIDAY. ATTEMPTED TO BLEND THIS TREND WITH BRIEFLY HOLDING TEMPS S AND E OF ALBANY, BEFORE THEY TOO LIKELY FALL LATER ON. LOWER POPS A BIT FRIDAY NIGHT, GOING ONLY SLIGHT CHANCE IN VALLEY LOCATIONS AND CHANCES ACROSS THE HIGHER TERRAIN DUE TO POSSIBLE WRAP AROUND. HAVE ENDED ALL PCPN BY 06Z. NICE WEATHER LOOKS TO FOLLOW SATURDAY AS HIGH PRESSURE BRIEFLY BUILD IN. WITH H8 TEMPS PROGGED TO BE AROUND 0C (SLIGHT COLDER ON THE GFS AND SLIGHTLY WARMER ON THE NAM) HAVE LOWERED TEMPS A CATEGORY PER BOTH MAV/MET OUTPUT. STILL...IT WILL BE THE NICER OF THE TWO WEEKEND DAYS. LONG TERM /SUNDAY THROUGH WEDNESDAY/...BY SUNDAY, THE NEXT WEATHER MAKER, LOOKING MORE LIKE CLIPPER, ARRIVES FROM THE GREAT LAKES. EARLIER RUNS HAD THIS FEATURE SLOWING DOWN, WHILE ENERGY FROM THE SOUTHERN BRANCH BECOME INJECTED INTO IT. BOTH THE EUROPEAN AND LATEST GFS NOW INDICATE THE TWAIN SHALL NEVER MEET, UNTIL WELL OFFSHORE. THIS WOULD MEAN ONLY A CLIPPER TYPE STORM WOULD AFFECT US LATE SUNDAY INTO EARLY MONDAY AS ANY SECONDARY COASTAL DEVELOPMENT WOULD SLIDE WELL TO OUR SOUTH AND EAST. CONSEQUENTLY THE ANTICIPATED RAINFALL WOULD LIGHTER. ON THE OTHER HAND, THE POLAR VORTEX, INITIALLY FORECAST TO EAST OF HUDSON BAY, IS NOW FORECAST TO MOVE OVER OUR HEAD! THIS CHANGE LOOKS A TAD UNREALISTIC AND THEREFORE WE WILL NOT TINKER WITH THE EXTENDED, BUT WAIT TO SEE IF THE NEXT SET OF RUNS CONTINUES TO INDICATE THESE CHANGES. AVIATION...CLOUD DECK PERSISTS OVER THE AREA UNDER STRONG INVERSION. LOOKING AT VFR CONDITIONS WITH CIGS OF 3500 FEET. MAY GET SOME MVFR FOG AROUND SUNRISE THIS MORNING. SHOULD HAVE SOME IMPROVEMENT TODAY WITH OVC DECK GOING TO BKN BUT HIGH CLOUDS WILL BE STREAMING IN AHEAD OF NEXT SYSTEM. EXPECT CONDITIONS TO LOWER TO MVFR LATE THIS AFTERNOON/EARLY THIS EVENING AS RAIN MOVES AND EVENTUALLY LOWERING TO IFR OVERNIGHT. FIRE WEATHER...FUELS REMAIN EXCESSIVELY MOIST ACROSS THE REGION WITH LITTLE OPPORTUNITY FOR THEM TO DRY FURTHER. RH VALUES WILL ONLY DROP TO AROUND 50 PERCENT THIS AFTERNOON...HIGHER ACROSS THE MOUNTAINS...THEN RISE BACK TO BETWEEN 90-100 PERCENT TONIGHT. TOMORROW...WITH MORE RAIN EXPECTED...RH VALUES WILL BE HIGHER THAN TODAY. A S WIND AROUND 10 KTS BY THIS AFTERNOON...WILL GRADUALLY BACK TO THE NW AND INCREASE TO AROUND 15 KNOTS WITH GUSTS TO 25 KNOTS BY LATE FRIDAY. DRY WEATHER IS EXPECTED SATURDAY WITH A GRADUAL SUBSIDING OF A GUSTY NW WIND. HYDROLOGY...THE SOUTHERN ADIRONDACKS AND CENTRAL MOHAWK VALLEY ARE THE AREAS OF CONCERN AFTER RECEIVING THE HEAVIEST RAINS TUESDAY AND TUESDAY NIGHT WITH 1 TO 3 INCHES. LOOKING AT ANOTHER WIDESPREAD SOAKING RAINFALL TONIGHT THROUGH MUCH OF FRIDAY AS A COLD FRONT GRADUALLY MOVES ACROSS THE REGION AS A WAVE OF LOW PRESSURE MOVES NORTHWARD ALONG THE BOUNDARY. BY FRIDAY EVENING...THE GFS HAS THE HEAVIEST AMOUNTS ACROSS THE ADIRONDACKS 1 1/2 TO 2 INCHES...WITH AROUND AN INCH ACROSS THE REST OF THE FORECAST. THE WRF HAS 1 1/2 TO 2 1/2 INCHES ACROSS MUCH OF THE FORECAST...GENERALLY THE CATSKILLS AND CAPITAL REGION NORTH AND WESTWARD. FLASH FLOOD GUIDANCE FOR SOUTHERN HERKIMER AND FULTON COUNTIES ARE THE LOWEST FOR 24-HOUR PERIOD WITH ONLY 2 1/2 INCHES...SO EXPECTED QPF APPROACHING THAT VALUE. LOOKING AT MORE RUNOFF WITH THIS SYSTEM AS GROUND WET FROM LAST ONE. WILL CONTINUE WITH FLOOD POTENTIAL OUTLOOK STATEMENT (ESF) AT THIS TIME. ANOTHER SYSTEM IS EXPECTED TO BRING MORE RAINFALL LATE IN THE WEEKEND INTO EARLY NEXT WEEK. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NY...FLOOD WATCH FOR NYZ032-033-038>043-048>050-082>084 FROM 6 AM FRIDAY TO 6 AM SATURDAY. VT...NONE. && $$ SHORT TERM...KL ny AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE LUBBOCK TX 1031 AM CDT THU OCT 19 2006 .UPDATE... UPDATE TO GRIDS/TEXT TO REMOVE MORNING PRECIP WORDING. ALSO HAD TO ADJUST SKY COVER FOR PERSISTENT AREA OF STRATUS ACROSS THE WRN AND CNTL ZONES. RUC AND WRF SUGGEST THIS AREA COULD HANG AROUND AS LATE AS 18Z/19Z. DECREASING CLOUDS OR CLEARING WORDING DROPPED INTO THE ZONE TEXT FOR THOSE AREAS. STRATUS MAY END UP HAVING A SMALL EFFECT ON TEMPS FOR TODAY...BUT FOR NOW TRENDS SEEMED GOOD ENOUGH TO LEAVE ALONE. && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 251 PM MDT THU OCT 19 2006 .SHORT TERM... (TONIGHT AND FRIDAY) CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSIS INDICATING MODERATE NORTHWEST FLOW ALOFT ACROSS THE REGION WITH A BROAD UPPER TROUGH PERSISTING ACROSS THE INTERMOUNTAIN WEST. WATER VAPOR IMAGERY IMAGERY ALSO INDICATING AN EMBEDDED SHORT WAVE MOVING ACROSS THE NORTHERN HIGH PLAINS WITH ANOTHER EMBEDDED WAVE MOVING ONSHORE ACROSS THE PAC NW COAST ATTM. AT THE SFC...1-2MB 3HRLY PRESSURE FALLS BEING NOTED ACROSS THE I-25 CORRIDOR IN RESPONSE TO THE NORTHWEST FLOW ALOFT. FOR TONIGHT...MODERATE NORTHWEST FLOW CONTINUES ACROSS THE REGION TONIGHT AND SLOWLY INCREASES OVERNIGHT AS PAC NW SHORT WAVE CONTINUES TO MOVE INTO THE NORTHERN GREAT BASIN. WITH THE INCREASING FLOW ALOFT...WINDY CONDITIONS EXPECTED ACROSS THE HIGHER TERRAIN OVERNIGHT...AND WITH LEE TROUGHING PERSISTING ACROSS THE I-25 CORRIDOR...A DECENT GRADIENT SETS UP FOR GAP FLOWS ACROSS THE LOWER EASTERN SLOPES. WITH THAT IN MIND...HAVE WARMED UP LOWS ACROSS THE EASTERN SLOPES AND IMMEDIATE EASTERN PLAINS...THOUGH HAVE GONE AOB COLDEST GUIDANCE ACROSS THE EASTERN PLAINS TONIGHT...THINKING THAT WINDS WILL DECOUPLE ENOUGH THIS EVENING TO ALLOW TEMPS TO TANK THROUGH THE LATE NIGHT HOURS...ESPECIALLY ACROSS THE LOWER ARKANSAS RIVER VALLEY. MODEL CROSS SECTIONS CONTINUE TO INDICATE THIN LAYER OF MOISTURE PERSISTING OVER THE CENTRAL MTS WITH THE NORTHWEST FLOW...THOUGH WITH POOR LAPSE RATES...NOT EXPECTING MUCH IN THE WAY OF ACCUMULATIONS OVERNIGHT. FRIDAY...WESTERLY FLOW INCREASES ALOFT AS EMBEDDED SHORT WAVE CONTINUES TO MOVE ACROSS THE GREAT BASIN AND INTO NORTHWESTERN COLORADO BY THE LATE AFTERNOON. CROSS SECTIONS INDICATING MOISTURE AND LAPSE RATES INCREASING AHEAD OF THE SYSTEM...WITH SNOW MODEL YIELDING 1 TO 3 INCHES ACROSS THE CENTRAL MTS...THOUGH WITH SOME QG IMPLIED ASCENT HAVE GONE WITH UP TO 4 INCHES ACROSS ZONES 58 AND 60 WITH LATER SHIFTS MAY BE NEEDING TO HOIST AN ADVISORY FOR LATE FRIDAY AFTERNOON AND NIGHT. PREFRONTAL TROUGH SETS UP ACROSS THE FAR EASTERN PLAINS THROUGH THE AFTERNOON...ALLOWING FOR BREEZY WESTERLY WINDS TO MIX DOWN ACROSS SOUTHEAST COLORADO...WITH DOWNSLOPE HELPING TEMPS TO CLIMB INTO THE 60S ACROSS THE PLAINS. -MW .LONG TERM... (FRIDAY NIGHT THROUGH THURSDAY) ...FCST CONCERNS THIS PD CONTINUE TO BE SAT WX SYSTEM AND A NEW SYSTEM FOR LATER IN THE WEEK... MAIN CONCERN CONTINUES TO BE WX SYSTEM FOR FRI NITE INTO SATURDAY. CURRENT WAT VAP IMGY CURRENTLY SHOWING THIS SYSTEM UP ACROSS S ALASKA AND INTO NW CANADA. SYSTEM LOOKS QUITE IMPRESSIVE IN THE IMGY. RAW MODEL DATA DOES NOT APPEARS ALL THAT IMPRESSIVE AS SYSTEM CROSSES OUR AREA BUT BELIEVE MODEL MAY BE A BIT UNDERDONE GIVEN CURRENT SAT PIX REPRESENTATION AND MODEL OUTPUT STATISTICS DATA. LATEST FCST BRINGS FRONT INTO AREA LATE THU AFTERNOON OR EARLY FRIDAY EVENING. GUSTY N WINDS SHOULD COME ALONG WITH THE FROPA. RAW GRIDDED DATA SHOWS SYSTEM RATHER DRY BUT BELIEVE THIS IS UNDERDONE AND HAVE CONTINUED CURRENT TREND IN BRING CLOUDS INTO REGION FRI EVENING. AS FOR POPS...GIVEN LAPSE RATES AND FORCING...BELIEVE THERE WILL BE SOME POTENTIAL FOR SOME STEADY WIND DRIVEN SNOW ACROSS THE C MTNS FRI EVE INTO SAT. AS MENTIONED ABOVE IS SHORT TERM DISCUSSION...HILITES WILL LIKELY BE NECESSARY FOR THIS REGION. ON PLAINS...BEST CHANCE OF PRECIP WILL BE ALONG S FACING SLOPES OF S MTNS AND ALONG THE I-25 CORRIDOR FRI EVE...AND THEN DOWN TOWARDS THE S SANGRES/RATON MESA REGION ON SATURDAY. I AM QUITE CONFIDENT THAT WE WILL ONCE AGAIN SEE COLDER TEMPS COME IN FRIDAY NITE AND INTO SAT. TEMPS SAT WILL LIKELY BE 20F COOLER THAN FRIDAY. BY SUNDAY...SHOULD SEE A BIT MORE SUN ON THIS DAY...BUT TEMPS WILL STILL BE ON THE COOL SIDE. FOR NEXT WEEK...NICE WX WITH TEMPS WARMING INTO THE 60S TO LOWER 70S WITH DRY WX. BY LATE IN THE WEEK...COUPLE RUNS OF THE GFS AND EURO MODELS ARE NOW SHOWING A RATHER IMPRESSIVE TROUGH DEVELOPING OVER THE INTERMOUNTAIN WEST. IF THE MODELS ARE A PERFECT PROG...THEN THIS WILL BE A PRETTY GOOD STORM...HOWEVER...FOR NOW...THE ONLY CHANGES I MADE TO THE LONG RANGE PERIOD WAS TO INTRODUCE A SLIGHT CHANCE OF PRECIP ACROSS THE REGION WED NITE INTO THU. \/HODANISH && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/34 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 624 PM EDT THU OCT 19 2006 .SHORT TERM /REST OF TONIGHT/... UPDATED ZONES/GRIDS TO REMOVE AFTERNOON WORDING AND INCLUDE CHC OF EVENING TSRA ACROSS MUCH OF CWA THIS EVENING. RUC MODEL SOUNDINGS INDICATE STEEP MID LEVEL LAPSE RATES WILL CONTINUE UNTIL LATE EVENING. RRM && .PREV DISCUSSION... /ISSUED 413 PM EDT THU OCT 19 2006/ SHORT TERM /TONIGHT - SUNDAY/... ACTIVE WEATHER CONTINUES IN THE SHORT TERM. A STRONG COLD FRONT IN FAR WRN NY AND PA WILL SLOWLY MOVE EAST TONIGHT. AHEAD OF THE FRONT IS A LINE OF SHOWERS AND THUNDERSTORMS IN THE UNSTABLE AIR. SKIES PARTIALLY CLEARED WITH TEMPS RISING TO NEAR 70. LIS HAVE GONE NEGATIVE. LARGER AREA OF RAIN IN OHIO VALLEY WILL MOVE NE AHEAD OF A DEVELOPING AND INTENSIFYING LOW IN THE SE US. RAIN TO GET HERE THIS EVENING AND CONTIUE INTO FRIDAY MORNING. THIS LONG PERIOD OF RAIN WILL DROP OVER AN INCH EVERYWHERE WITH A STRIP CLOSE TO 2 INCHES FROM SW TO NE ELM TO UCA. THIS STRIP COULD SHIFT SOME DEPENDING ON WHERE THE SFC LOW TRACKS. FOR NOW THE TRACK OF THE LOW WILL BE OUR SE CWA FRI MORNING. MOST MODELS HAVE SIMILAR TRACKS. FOR ENDING TIME GFS FASTEST MIDDAY WITH NAM IN THE AFTN. THIS AMOUNT OF RAIN ONLY EXPECTED TO RAISE THE MOHAWK AT UTICA TO OVER FLOOD STAGE. THE RIVER ALREADY RUNNING HIGH WITH DELATA DAM FULL. OTHER STREAMS AND RIVERS WILL EXPERIENCE RISES BUT ARE NOT EXPECTED TO FLOOD. WITH THE LOW DEEPENING OVER NEW ENGLAND FRI PM...WINDS WILL PICK UP ESPECIALLY IN THE E. STILL BELOW ADVISORY CRITERIA BUT THIS WILL BRING IN THE COLD AIR FASTER. FRI NGT SOME SHOWERS POSSIBLE WHICH COULD CHANGE TO SNOW. POPS ARE AT 20 PERCENT WITH MARGINAL LAKE INSTABILITY. THIS WILL BE SHORT SHOT OF COLD AIR WITH WAA ON SATURDAY AHEAD OF THE NEXT SYSTEM. SFC HIGH BUILDS WITH WEAK UL RIDGING. FOR SUNDAY DIFFERENCES BETWEEN THE MODELS ON TIMING OF PRECIP. FOR NOW WENT WITH CHC POPS EVERYWHERE. THE NEXT STRONG COLD FRONT WILL CROSS THE CWA SUNDAY NIGHT. GFS BRINGS IN RAIN EARLY SUNDAY WITH THE NAM HOLDING OFF UNTIL AFTN. TAC AVIATION /191800Z - 201800Z/... CIGS ARE VARYING FROM 030-035 OVER THE VALLEYS TO 015-020 OVER THE MOUNTAINS. AREA OF MVFR CIGS AND SHOWERS WITH ISOLD TSTMS WILL MOVE ACROSS THE AREA BETWEEN 18Z AND 00Z. THIS IS ASSOCIATED WITH A COLD FRONT OVER LAKE ONTARIO AND LAKE ERIE AT 18Z MOVING INTO CENTRAL NY. FRONT WILL STALL AND RAIN WILL BECOME STEADIER AND MORE WIDESPREAD OVER THE REGION AND CIGS WILL LOWER TO IFR. AN AREA OF LOW PRESSURE WILL MOVE UP THE FRONT BRINGING WIDESPREAD LIGHT TO MODERATE RAIN AND LOW IFR CIGS. CONDITIONS WILL BEGIN TO IMPROVE FROM THE S AND W TOWARD 18Z AS THE LOW CENTER MOVES OFF TO THE NE. -BMW LONG TERM /SUNDAY NIGHT - THURSDAY/... FOLLOWED HPC GUIDENCE. PERIOD LOOKS UNSETTLED. SUNDAY NIGHT COLD FRONT MOVES OFF THE E COAST WITH COLD ADVECTION CROSSING THE LAKES DEVELOPING LAKE ENHANCED CLOUDS AND SHOWERS MONDAY AND TUESDAY AS UPPER LOW MOVES ACROSS AREA. TEMPERATURES WILL COOL ENOUGH BY TUE FOR SNOW TO MIX INTO SHOWERS DURING THE DAY TUESDAY AND WEDNESDAY WITH JUST CHANCE SNOW SHOWERS OVERNIGHT. UPPER LOW MOVES OFF COAST WED WITH LAKE ENHANCED CLOUDS AND SHOWERS CONTINUING AND DIMINISHING INTO THURSDAY. TEMPERATURES WARMING BY THURSDAY BUT STILL BELOW SEASONAL NORMALS. -BMW && .BGM WATCHES/WARNINGS/ADVISORIES... NY...FLOOD WATCH FOR NYZ009-037 FROM 6 AM FRIDAY TO 6 AM SATURDAY. PA...NONE. && $$ ny