Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/03/13


AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
729 PM MST WED JAN 2 2013 .UPDATE...MID LEVEL CLOUDS WERE SPILLING SOUTHWARD FROM WYOMING AND THE NEBRASKA PANHANDLE THIS EVENING. CLOUDS SHOULD CONTINUE TO INCREASE ACROSS THE PLAINS GIVEN UPSTREAM OBSERVATIONS AND DEEP NORTHERLY FLOW. LATEST RAP AND NAM CROSS SECTIONS ALSO SUPPORTED THIS IDEA. CANT RULE OUT A FEW FLURRIES OVER THE NORTHEAST CORNER GIVEN THE LATEST OBS AT KIBM AND KAIA IN THE NEBRASKA PANHANDLE. WILL UPDATE FOR MORE CLOUDS OVER MOST OF THE PLAINS AND FLURRIES OVER THE NORTHEAST CORNER. && .AVIATION...EXPECT A MID LEVEL CLOUD DECK TO DEVELOP OVER THE FRONT RANGE AIRPORTS FROM 03Z-07Z AND THEN DISSIPATE AGAIN BY 11Z-13Z AS DRIER AIR MOVES IN AT THAT TIME. CLOUD DECK SHOULD AVERAGE NEAR 7000 FT AGL BUT CANT RULE OUT A COUPLE PERIODS OF BELOW 6000 FT AGL FOR ILS LANDINGS. THESE SLIGHTLY LOWER CONDITIONS WOULD MOST LIKELY OCCUR IN THE 06Z-12Z TIME FRAME. LIGHT WINDS. && .PREV DISCUSSION... /ISSUED 256 PM MST WED JAN 2 2013/ SHORT TERM...WEB CAMS ACROSS MOUNTAINS STILL SHOWING AREAS OF LIGHT SNOW CONFINED MAINLY TO THE CONTINENTAL DIVIDE OF SUMMIT AND GRAND COUNTIES AS WELL AS PORTIONS OF THE GORE RANGE IN WESTERN JACKSON COUNTY. THERE HAS BEEN A GRADUAL DECREASE IN THE LAST FEW HOURS AS DRIER AND SLIGHTLY WARMER AIR SPREADS INTO THE REGION. ACROSS PLAINS....ENOUGH MIXING ALLOWED NORTHWESTERLIES TO MIX TO SURFACE...MAINLY NEAR THE WYOMING BORDER AND FAR EASTERN ZONES. IN ADDITION...SURFACE ANTICYCLONE DEVELOPED NORTH OF DENVER WHICH KEPT WINDS MORE NORTHERLY. LATEST RUC SHOWS ELONGATED UPPER TROUGH CURRENTLY OVER COLORADO MOVING SOUTH DURING THE EVENING WITH FLOW ALOFT BECOMING MORE NORTHERLY. DRIER SUBSIDENT AIR TO CONTINUE TO MOVE ACROSS REGION...SHOULD SEE ANY LINGERING SNOW COME TO AN END WITH CLEARING SKIES. THERE MAY BE A BATCH OF MID LEVEL CLOUD MOVE ACROSS THE EASTERN PLAINS DURING THE EVENING. OTHERWISE...SKIES TO GRADUALLY CLEAR BY MIDNIGHT. AS AIRMASS STABILIZES...SHOULD SEE WINDS DECREASE ACROSS PLAINS BUT REMAIN A BIT GUSTY OVER THE RIDGES. MODELS STILL HINTING A WEAK MOUNTAIN WAVE OVERNIGHT. BUT FLOW ALOFT NOT THAT STRONG AND MORE NORTHERLY. COULD SEE SOME GUSTS APPROACH 50 MPH IN FAVORED AREAS OF GRAND...JACKSON AND PARK COUNTIES AFTER MIDNIGHT. WITH THE CLEARING SKIES AND THE PERSISTANT INVERSIONS ALONG WITH LIGHTER WINDS...SHOULD SEE TEMPS DROP WELL BELOW ZERO IN THE MOUNTAIN VALLEYS AS WELL AS LOW LYING AREAS ACROSS THE PLAINS. DID LOWER MINS NEAR KREMMLING A FEW MORE DEGREES TO ACCOUNT FOR THE CLEARING SKIES. ENOUGH DRAINAGE IN AND NEAR FOOTHILLS TO KEEP TEMPS A BIT WARMER. ON THURSDAY...UPPER TROUGH TO CONTINUE TO MOVE SOUTHEAST AS UPPER RIDGE BUILDS ACROSS COLORADO FROM THE NORTHWEST. THIS WILL RESULT IN A NORTHEAST FLOW ALOFT OVER THE REGION. CROSS SECTIONS INDICATE THE AIRMASS WILL BE FAIRLY DRY WITH MAINLY HIGH LEVEL MOISTURE. TEMPERATURES TO BEGIN TO MODERATE A BIT...THOUGH INVERSIONS WILL LIMIT WARMUP... ESPECIALLY IN LOW LYING AREAS. HIGHS MAY STRUGGLE TO GET ABOVE ZERO NEAR KREMMELING. TEMPERATURES ACROSS THE PLAINS SHOULD BE MAINLY IN THE LOWER 30S...WITH MID TO UPPER 20S NEAR GREELEY. LONG TERM...THE CURRENT AMPLIFIED RIDGE/TROUGH PATTERN OVER THE EASTERN PACIFIC AND WESTERN UNITED STATES WILL GRADUALLY WEAKEN LATE THURSDAY INTO FRIDAY AS A FAST NORTHEASTWARD MOVING PACIFIC THROUGH OF LOW PRESSURE ENTERS THE PAC NW COAST. THIS WILL WEAKEN THE RIDGE OVER THE ROCKIES AND PROVIDE A FAIRLY DISORGANIZED FLOW PATTERN OVER THE WESTERN HALF OF THE US INCLUDING NE COLO. AS THE WEAKENING RIDGE MOVES EASTWARD AND FLATTENS...THE WARMEST MID LEVEL TEMPS FOLD OVER ONTO THE CENTRAL ROCKIES AND WILL GIVE WAY TO THE START OF WARMER TEMPERATURES EXPECTED IN THE EXTENDED WITH TEMPS REBOUNDING TO NEAR TO ABOVE SEASONAL NORMALS. BY LATE FRIDAY INTO SATURDAY...THE DISORGANIZED FLOW ALOFT OVER THE ROCKIES GIVES WAY TO A VERY WEAK AND DRY UPPER LOW OVER THE OK PANHANDLE. QG VERTICAL VELOCITY FIELDS INDICATE VERY LIGHT LIFT ASSOC WITH THIS OVER NE CO AND WILL KEEP THE PERIOD DRY. THIS UPPER LOW IS EVENTAULLY DRAWN INTO A ALBERTA CLIPPER-TYPE FEATURE DROPPING OUT OF CANADA AND QUICKLY EVACUTES THE REGION TO THE NE US. WILL NEED TO WATCH IN LATER RUNS IF THIS FAST DROPPING CANADIAN TROUGH PUSHES A WEAK BUT DRY COLD FRONT/SURGE INTO EASTERN COLORADO FOR LATE SATURDAY INTO SUNDAY. IF SO...ONLY TEMPS LOOK TO BE COOLED SLIGHTLY FOR SUNDAY. BY SUNDAY...UPPER RIDGE BECOMES FIRMLY REESTABLISHED OVER THE ROCKIES AND CENTRAL US AS THE NEXT UPPER TROUGH APPROACHES THE CALI COAST. TEMP GUIDANCE WOULD SUGGEST TEMPS WARMING TO ABOVE SEASONAL NORMALS...MAINLY FOR THE LOWER ELEVATIONS AND AREAS WITHOUT A SOLID SNOWPACK. STILL EXPECT MTN VALLEYS TO REMAIN COLD DURING THE NIGHT PERIODS. LOOKING TOWARD MONDAY AND INTO THE MIDDLE OF NEXT WEEK...GFS SWINGS ANOTHER FAST MOVING TROUGH OVER THE US/CAN BORDER WHILE A SECOND COLD FRONT LOOKS TO CLIP THE NORTHERN AND EASTERN PORTION OF COLO. AT THIS TIME FRONT LOOKS DRY. BEYOND MONDAY GFS INDICATES VERY BENIGN DRY FLOW OVER THE STATE AS THE TROUGH OFF OF THE CALI COAST DROPS AND WEAKENS INTO THE BAJA REGION. THIS PERIOD ALSO REMAINS DRY WITH NO DISCERNABLE TEMP ADVECTION THROUGHOUT ENTIRE ATMOS. AVIATION...ANTICYCLONE NORTH OF THE DENVER AREA HAS KEPT NORTHERLY WINDS AT DEN WITH NORTHEAST WINDS AT BJC AND APA. WINDS HAVE BEEN A BIT GUSTY AT DEN...BUT ARE SHOWING SIGNS OF DECREASING. WINDS TO CONTINUE TO WEAKEN ACROSS THE AREA AIRPORTS AND BECOME MORE SOUTHEAST THROUGH 02Z...THEN SOUTHWEST BY 04Z AS DRAINAGE PATTERN DEVELOPS. VFR TO PREVAIL WITH UNLIMITED CEILINGS. A BATCH OF MID LEVEL CLOUD MAY MOVE ACROSS THE REGION DURING THE EVENING WITH CEILINGS AROUND 10000 FEET FOR A SHORT TIME. ON THURSDAY...SOUTHERLY WINDS TO PREVAIL WITH SPEEDS LESS THAN 10 KTS. WINDS COULD TREND TOWARD THE SOUTHEAST AT DEN AND APA DURING THE AFTERNOON. VFR TO CONTINUE. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARJENBRUCH LONG TERM....FREDIN AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
916 PM MST MON DEC 31 2012 .UPDATE... ISSUED AT 904 PM MST MON DEC 31 2012 SNOWFALL HAS DECREASED OVER THE SAN JUAN MOUNTAINS AND PORTIONS OF SOUTHWEST COLORADO...AND WILL CONTINUE TO DO SO. THE WINTER WEATHER ADVISORY WAS ALLOWED TO EXPIRE. ONLY LOCALLY LIGHT ADDITIONAL ACCUMULATIONS ARE EXPECTED OVERNIGHT...MAINLY ON NORTH AND NORTHWEST FACING SLOPES OF THE SAN JUAN MOUNTAINS. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 300 PM MST MON DEC 31 2012 IMPROVING CONDITIONS AS THE ACTIVE SHORT WAVE MOVES DOWNSTREAM...EXCEPT FOR SOME ENHANCED CONVECTIVE SNOW SHOWERS OVER THE SAN JUANS. SOME OF THIS ACTIVITY STILL IMPACTING PAGOSA SPRINGS...AND THE HIGHER RESOLUTION RAP MODEL KEEPS SNOW ONGOING INTO THE EVENING HOURS BUT ENDING BY MID EVENING. REFINED THE WINTER WEATHER ADVISORY FOR THIS AREA AS CONFIDENCE IS HIGH THAT SNOW WILL HAVE ENDED BY LATE EVENING. WITH PARTIAL CLEARING OVERNIGHT...TEMPERATURES WILL PLUNGE AFTER SUNSET AND THEN LEVEL OUT AROUND MIDNIGHT. UPSTREAM DISTURBANCE OVER MONTANA AND NORTH DAKOTA KEEPS A TROUGH CARVED OUT OVER WESTERN COLORADO ON NEW YEARS DAY. MOISTURE SOURCE FOR THIS SHORT WAVE IS CONTINENTAL AND THEREFORE PRECIPITABLE WATER IS LOW...BUT DOES KEEP THE AIR MASS UNSETTLED DURING THE LATE MORNING AND EARLY AFTERNOON HOURS. EXPECT SHALLOW CONVECTIVE SNOW SHOWERS OR FLURRIES TO FORM ACROSS THE HIGH COUNTRY. AREAL COVERAGE WILL NOT BE WIDESPREAD AND FAVOR NORTH FACING SLOPES. ESSENTIALLY THIS SHORT WAVE KEEPS THE COLD AIR MASS LOCKED IN. 2013 STARTS THE WAY THAT 2012 ENDED...COLD WITH LITTLE CHANGE. THE FOLLOWING UPSTREAM WAVE BRUSHES THE PARK/GORE RANGE LATE ON TUESDAY NIGHT. LIMITED MOISTURE ONCE AGAIN BUT SOME OROGRAPHIC FLURRIES ARE EXPECTED...OTHERWISE MOSTLY CLEAR WITH STRONG RADIATIONAL COOLING AS SURFACE HIGH PRESSURE COVERS THE REGION. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 300 PM MST MON DEC 31 2012 IN GENERAL...LOOKS LIKE A MOSTLY DRY LAST HALF OF THE WEEK AS A BLOCKING RIDGE DEVELOPS OVER THE INTERMOUNTAIN WEST WED AND THU. AS THIS OCCURS...A SHORTWAVE IN NORTHERLY FLOW CLIPS OUR AREA WED AS IT DROPS FROM CENTRAL CANADA THROUGH THE PLAINS. LITTLE MOISTURE ASSOCIATED WITH IT OVER CO...SO WILL CONTINUE WITH JUST A SLIGHT CHANCE OF SNOW MAINLY NEAR THE CONTINENTAL DIVIDE. LATE IN THE WEEK...A PACIFIC SHORTWAVE FIGHTS THROUGH/OVER THE RIDGE CROSSING THE NORTHERN ROCKIES EARLY ON FRIDAY AND BRUSHING BY OUR AREA ON SATURDAY. AGAIN...LITTLE MOISTURE ASSOCIATED WITH IT IN THE MODELS. RIDGE REBOUNDS OVER UT/CO BY SUNDAY. ECMWF THEN BRINGS A PROGRESSIVE PACIFIC TROUGH ACROSS OUR AREA ON MONDAY...WHILE THE GFS INSTEAD CLOSES OFF A LOW ALONG THE WEST. THE MAIN CHALLENGE FOR THIS FORECAST PERIOD MAY BE THE VALLEY TEMPERATURES...WHICH WILL BE SLOW TO WARM. SNOW COVER AND TRAPPED COLD AIR WITH HIGH PRESSURE AT THE SURFACE WILL PROMOTE SURFACE INVERSIONS WED-FRI THAT WILL BE DIFFICULT TO DISLODGE. THE WEAK DISTURBANCES WED AND SAT DON/T LOOK STRONG ENOUGH TO SCOUR OUT MANY VALLEYS...AND AREAS LIKE THE GRAND VALLEY AND I-70 CORRIDOR WILL SEE AIR QUALITY SLOWLY DECLINE. HAVE UNDERCUT MOS AND CONSENSUS GUIDANCE FOR THE VALLEYS AS A RESULT. HIGHER ELEVATIONS... HOWEVER...SHOULD SEE A SLOW MODERATION IN TEMPS BY THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 904 PM MST MON DEC 31 2012 LOCAL MOUNTAIN OBSCURATIONS WILL CONTINUE OVERNIGHT ACROSS THE COLORADO MOUNTAINS...MAINLY NEAR THE CONTINENTAL DIVIDE. KASE... KEGE AND KMTJ WILL CONTINUE TO EXPERIENCE INTERMITTENT LIGHT SNOW AND THIN FOG WITH MVFR CIGS AND VSBYS. AFTER 09Z...AREAS OF IFR CIGS AND VSBYS WILL DEVELOP IN VALLEY BOTTOMS...ESPECIALLY NEAR RIVERS...AS LOW STRATUS AND FOG DEVELOPS. THESE CONDITIONS WILL DIMINISH AFTER ABOUT 16Z TUESDAY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...CC SHORT TERM...PF LONG TERM...JAD AVIATION...CC
MY LAST FORECAST DISCUSSION. ALTHOUGH THESE WORDS WILL PASS WITH THE
WIND...THE CAMARADERIE SHARED WITH YOU MY FELLOW WEATHER WATCHERS
WILL ALWAYS BE CHERISHED. MAY THE SUN SOFTLY WARM YOU, THE RAIN GENTLY SATISFY YOU, AND GOD BE WITH YOU...ALWAYS. LOU GIORDANO && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... MODELS GENERALLY CONTINUE TO ADVERTISE A WEAK SYSTEM PASSING MAINLY TO OUR NORTH CENTERED AROUND THURSDAY NIGHT. THIS SYSTEM LOOKS VERY POSITIVELY TILTED ON THE MODELS AND FAILS TO FEED MUCH WARM/MOIST AIR UP AHEAD OF IT...LIKELY DUE TO THE DRY AIR MASS IN PLACE OVER THE EASTERN PORTIONS OF THE CONUS BY THAT TIME. AS SUCH...EVEN WITH SOME LIFT...PRECIPITATION WILL BE DIFFICULT TO GENERATE. AT THE MOMENT IT SEEMS MOST DECENT SNOW SHOWERS THAT DEVELOP WILL BE RELEGATED TO THE NORTHERN PORTIONS OF THE FORECAST AREA AND THE RIDGES...WHERE WESTERLY/NORTHWESTERLY UPSLOPE FLOW MAY HELP TO ACCENTUATE LIFT. REGARDLESS OF THE SOLUTION...QPF IS PRETTY MEAGER WITH THIS SYSTEM. ADDITIONALLY...ITS FORWARD PHASE SPEED IS PRETTY QUICK. AS A RESULT...ANY ACCUMULATIONS FROM SNOW SHOWERS WILL BE QUITE SMALL. COLD AIR LOOKS TO PERSIST OVER THE AREA INTO THE WEEKEND...WITH A STRONG CONSENSUS ON NORTHWESTERLY FLOW BEING THE MAIN PLAYER IN THE FORECAST. AS SUCH...THINGS SHOULD REMAIN DRY WITH CONTINENTAL AIR IN CONTROL. HOWEVER...TEMPERATURES WILL CONTINUE WELL BELOW NORMAL. FRIES && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... RELATIVELY QUIET WEATHER EXPD FOR THE LONG TERM PD. A WK COLD FRONT IS EXPD TO MOVE THROUGH THE RGN SUNDAY. WL KEEP CHC POPS FOR SHSN...WITH SLIGHTLY HIGHER POPS IN THE NORTH WHERE SOMEWHAT DEEPER MOISTURE IS FCST. COULD SEE A FEW SHSN IN NW FLOW BEHIND THE FRONT BUT H8 FLOW QUICKLY TURNS ANTICYCLONIC CUTTING OFF ANY REMAINING SHSN. HIGH PRES BLDS IN SUN NT THROUGH WED...WITH SEVERAL LOW PRES SYSTEMS PASSING BY WELL TO OUR NORTH. SHOULD SEE A SLOW WARMING TREND AS WELL BY NEXT WEEK...ALTHOUGH PREFERRED TO STAY ON THE COOL SIDE OF GUIDANCE...OR SLIGHTLY BELOW. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... MVFR STRATOCU CEILINGS PERSIST ACROSS KFKL AND KDUJ. ELSEWHERE GENERAL VFR CONDITIONS UNDER SOME HIGH BROKEN CIRRUS. RIDGE BUILDING INTO THE DISTRICT IN THE EARLY MORNING WILL BACK WINDS TO A MORE WESTERLY DIRECTION...SCATTERING OUT CEILINGS IN THE NORTH IN THE EARLY MORNING. THE HIGH WILL SHIFT EAST THURSDAY AS A SURFACE TROUGH APPROACHES FROM THE WEST. THE TROUGH COULD BRING MVFR CIGS AGAIN BY THURSDAY EVENING. .OUTLOOK.../THURSDAY NIGHT THROUGH MONDAY/... CEILING RESTRICTIONS THURSDAY NIGHT SHOULD END FRIDAY AS HIGH PRESSURE BUILDS IN. RESTRICTIONS ARE POSSIBLE AGAIN SATURDAY NIGHT AND SUNDAY AS A WEAK COLD FRONT MOVES ACROSS THE GREAT LAKES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
826 PM EST WED JAN 2 2013 .SYNOPSIS... EASTBOUND HIGH PRESSURE WILL PROVIDE DRY COLD CONDITIONS ACROSS THE UPPER OHIO VALLEY OVERNIGHT AND THURSDAY. A COLD FRONT MOVING EASTWARD THROUGH THE GREAT LAKES MAY SPAWN SCATTERED LIGHT SNOW SHOWERS THURSDAY NIGHT. && .NEAR TERM /THROUGH THURSDAY/... BASED ON BLEND OF RECENT SURFACE AND SATELLITE DATA ALONG WITH RECENT RAP AND SREF MODEL OUTPUT...EXPECT BANDS OF JETSTREAK- RELATED CIRROSTRATUS TO MOVE EASTWARD ACROSS THE UPPER OHIO VALLEY OVERNIGHT. WITH SURFACE LAYER REMAINING RATHER DRY WITH SNOWPACK UNDERNEATH...NOCTURNAL RADIATIONAL COOLING WILL BE ONLY SLIGHTLY MITIGATED. HENCE MADE ONLY MINOR UPWARD ADJUSTMENTS TO OVERNIGHT TEMPERATURES. THIS YIELDED LOWS IN THE SINGLE DIGITS FOR MOST LOCALES...WHICH WAS GENERALLY 5 DEGREES WARMER THAN WHAT THE STATISTICAL GUIDANCE SUCH AS GFS AND NAM MOS SHOWED. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... MODELS GENERALLY CONTINUE TO ADVERTISE A WEAK SYSTEM PASSING MAINLY TO OUR NORTH CENTERED AROUND THURSDAY NIGHT. THIS SYSTEM LOOKS VERY POSITIVELY TILTED ON THE MODELS AND FAILS TO FEED MUCH WARM/MOIST AIR UP AHEAD OF IT...LIKELY DUE TO THE DRY AIR MASS IN PLACE OVER THE EASTERN PORTIONS OF THE CONUS BY THAT TIME. AS SUCH...EVEN WITH SOME LIFT...PRECIPITATION WILL BE DIFFICULT TO GENERATE. AT THE MOMENT IT SEEMS MOST DECENT SNOW SHOWERS THAT DEVELOP WILL BE RELEGATED TO THE NORTHERN PORTIONS OF THE FORECAST AREA AND THE RIDGES...WHERE WESTERLY/NORTHWESTERLY UPSLOPE FLOW MAY HELP TO ACCENTUATE LIFT. REGARDLESS OF THE SOLUTION...QPF IS PRETTY MEAGER WITH THIS SYSTEM. ADDITIONALLY...ITS FORWARD PHASE SPEED IS PRETTY QUICK. AS A RESULT...ANY ACCUMULATIONS FROM SNOW SHOWERS WILL BE QUITE SMALL. COLD AIR LOOKS TO PERSIST OVER THE AREA INTO THE WEEKEND...WITH A STRONG CONSENSUS ON NORTHWESTERLY FLOW BEING THE MAIN PLAYER IN THE FORECAST. AS SUCH...THINGS SHOULD REMAIN DRY WITH CONTINENTAL AIR IN CONTROL. HOWEVER...TEMPERATURES WILL CONTINUE WELL BELOW NORMAL. FRIES && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... RELATIVELY QUIET WEATHER EXPD FOR THE LONG TERM PD. A WK COLD FRONT IS EXPD TO MOVE THROUGH THE RGN SUNDAY. WL KEEP CHC POPS FOR SHSN...WITH SLIGHTLY HIGHER POPS IN THE NORTH WHERE SOMEWHAT DEEPER MOISTURE IS FCST. COULD SEE A FEW SHSN IN NW FLOW BEHIND THE FRONT BUT H8 FLOW QUICKLY TURNS ANTICYCLONIC CUTTING OFF ANY REMAINING SHSN. HIGH PRES BLDS IN SUN NT THROUGH WED...WITH SEVERAL LOW PRES SYSTEMS PASSING BY WELL TO OUR NORTH. SHOULD SEE A SLOW WARMING TREND AS WELL BY NEXT WEEK...ALTHOUGH PREFERRED TO STAY ON THE COOL SIDE OF GUIDANCE...OR SLIGHTLY BELOW. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... MVFR STRATOCU CEILINGS PERSIST ACROSS KFKL AND KDUJ. ELSEWHERE GENERAL VFR CONDITIONS UNDER SOME HIGH BROKEN CIRRUS. RIDGE BUILDING INTO THE DISTRICT IN THE EARLY MORNING WILL BACK WINDS TO A MORE WESTERLY DIRECTION...SCATTERING OUT CEILINGS IN THE NORTH IN THE EARLY MORNING. THE HIGH WILL SHIFT EAST THURSDAY AS A SURFACE TROUGH APPROACHES FROM THE WEST. THE TROUGH COULD BRING MVFR CIGS AGAIN BY THURSDAY EVENING. .OUTLOOK.../THURSDAY NIGHT THROUGH MONDAY/... CEILING RESTRICTIONS THURSDAY NIGHT SHOULD END FRIDAY AS HIGH PRESSURE BUILDS IN. RESTRICTIONS ARE POSSIBLE AGAIN SATURDAY NIGHT AND SUNDAY AS A WEAK COLD FRONT MOVES ACROSS THE GREAT LAKES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1041 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL PROVIDE THE RISK FOR SNOW SHOWERS THROUGH THE MORNING HOURS. MUCH COLDER AIR WILL SETTLE IN BEHIND THE FRONT BEGINNING THIS AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE STILL VERY UNIMPRESSIVE PRECIPITATION REGIME OVER THE AREA IS BEING DRIVEN BY WHAT WOULD SEEMINGLY BE VERY IMPRESSIVE DYNAMICS THIS MORNING. THE 12Z KPBZ RAOB INDICATED A NEARLY 190 KT JET OVERHEAD...WHICH IS VERY IMPRESSIVE FOR ANY TIME OF THE YEAR...WHILE A VERY STRONG LOW LEVEL THERMAL GRADIENT WAS EVIDENT OVER THE LOWER GREAT LAKES AS WELL. TEMPERATURES FROM THE MID- MISSISSIPPI VALLEY TO THE UPPER OHIO VALLEY GENERALLY WERE IN THE UPPER 20S TO LOWER 30S...WHILE JUST TO THE NORTH IN THE GREAT LAKES REGION...TEMPERATURES WERE GENERALLY 0 TO -15F AS OF THE LAST FEW HOURS. THE LEADING EDGE OF THE COLDER AIR AS PROGRESSED SLOWLY SOUTHWARD INTO OHIO AND NORTHWESTERN PENNSYLVANIA THIS MORNING...HOWEVER IT REALLY WILL NEED AN ADDITIONAL KICK TO MOVE FARTHER. THE KICK TO THE FRONT LOOKS TO COME THROUGH THIS AFTERNOON AS A FAIRLY POTENT MID-LEVEL WAVE TRACKS DOWN THE FRONTAL ZONE THROUGH THE VERY HIGH SPEED UPPER FLOW. COLD AIR ADVECTION LOOKS TO KICK IN BEHIND IT...WHICH WOULD MAKE OUR DIURNALS TODAY JUST ABOUT ZILCH. AS SUCH...POPS WERE FOCUSED AHEAD OF THIS WAVE AND SOUTH OF THE FRONTAL ZONE THROUGH THE DAY. WHILE POPS ARE FAIRLY HIGH...QPF AND SNOW AMOUNTS ARE NOT. AS A CONTINUATION FROM LAST EVENING AND LAST NIGHT`S ACTIVITY...ICE MICROPHYSICS ARE QUITE POOR. AS SUCH...IT SEEMS UNLIKELY THAT ANYONE WILL SEE ANYTHING MORE THAN AN INCH TODAY...WHILE MOST AREAS SEE MUCH LESS. FRIES && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... FLOW ALOFT BEGINS TO WANE TONIGHT...BUT THE COLD AIR WILL CONTINUE TO PLUNGE INTO THE AREA. STRONG HIGH PRESSURE WILL MOVE ACROSS THE MIDWEST. WILL LEAVE IN CLOUDS OVERNIGHT...BUT WITH INVERSIONS SO LOW...ONLY EXPECT SNOW SHOWERS IN THE RIDGES. TEMPS OVERNIGHT WILL BE WELL BELOW NORMAL. SFC HIGH PRESSURE WILL MOVE FROM THE MIDWEST INTO THE OHIO VALLEY ON WED. THE CORE OF THE COLD POOL WILL BEGIN TO MOVE NORTHEASTWARD AS 85H RIDGES MOVE EASTWARD. STILL EXPECT LOTS OF CLOUDS WED...BUT THERE WILL BE SOME IMPROVEMENT IN THE AFTERNOON. TEMPS AGAIN...WELL BELOW NORMAL. ANOTHER SHORTWAVE TROUGH WILL SWING THROUGH LATE THURSDAY. WITH WINDS VEERING TO THE WEST-SOUTHWEST...TEMPS WILL MODERATE A BIT ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... GENERAL AGREEMENT IN THE MODELS ON THE OVERALL PATTERN THROUGH THE LONG TERM PD...ALTHOUGH PREFER GEFS/NAEFS FOR TIMING OF INDIVIDUAL FEATURES. A WK COLD FRONT WL MOVE ACRS THE RGN THU NT...HOWEVER DEEP MOISTURE IS CONFINED WELL TO THE NORTH. COULD SEE A FEW SHSN IN NW FLOW BEHIND THE FRONT BUT INVERSION SHOULD LIMIT DEPTH OF CLOUDS TO KEEP ACTIVITY MINIMAL...SO KEPT ONLY LOW CHC POPS N OF PIT. HIGH PRES BLDS IN SAT BEFORE ANOTHER WK FRONT PASSES THROUGH SAT NT...AGAIN WITH MOST OF THE MOISTURE STAYING NORTH. THIS SHOULD BRING MAINLY JUST AN INCREASE IN CLOUDS. HIGH PRES RIDGES BACK IN MON. TEMPS WL AVG BLW NORMAL MOST OF THE PD. OPERATIONAL MODELS WARM THINGS UP MON...BUT ENSEMBLES ARE NOT AS AGGRESSIVE. STAYED CLOSER TO COOLER ENSEMBLE MEANS. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... RECENT SURFACE RADAR AND SATELLITE DATA COUPLED WITH RECENT RAP NAM AND SREF MODEL OUTPUT SHOW JETSTREAK-RELATED COLD FRONTAL BAND OF LIGHT IFR SNOW WILL CONTINUE TO PASS EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH ABOUT 17Z. POSTFRONTAL COLD POOL COUPLED WITH LAKE-MOISTENED WEST TO NORTHWEST SURFACE LAYER WINDS WILL MAINTAIN MVFR CONDITIONS INTO TONIGHT. ANY REMAINING PRECIPITATION...BE IT SNOW OR FREEZING DRIZZLE...WILL BE VERY LIGHT AS SURFACE MIXED LAYER WILL BE CAPPED AT 5 KFT AGL. SURFACE WINDS WILL GO FROM SOUTHWEST TO WEST AT 8 KTS THIS MORNING...TO NORTHWEST AT 10 KTS THIS AFTERNOON...THEN BECOME WESTERLY AT NO MORE THAN 6 KTS TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... COLD POOL MVFR STRATOCUMULUS WILL REMAIN THROUGH AT LEAST WEDNESDAY. HIGH PRESSURE SUBSIDENCE MAY PROMOTE A VFR BREAK THURSDAY BEFORE A COLD FRONT PROVIDES THE NEXT ROUND OF RESTRICTIONS FRIDAY AND SATURDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
800 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL PROVIDE THE RISK FOR SNOW SHOWERS THROUGH THE MORNING HOURS. MUCH COLDER AIR WILL SETTLE IN BEHIND THE FRONT BEGINNING THIS AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... QUICK MRNG UPDATE TO INCRS POPS ACRS THE SRN CWA BASED ON RADAR/SFC OBS. NO OTHER CHGS ATTM. PREVIOUS... FRONT IS SLOWLY MOVING INTO NW PA AND WILL CONTINUE IT ARDUOUS TREK SOUTHWARD. LIGHT SNOW SHOWERS HAVE REDEVELOPED ON THE SOUTHERN FLANK OF THE BOUNDARY AS A STRONG UPPER LEVEL WAVE IS RUNNING ALONG THE NORTHERN SIDE OF THE FRONT AND PROVIDING LIFT. THIS WAVE WILL ALSO HELP TO GET THE FRONT MOVING SOUTHWARD...WHICH WILL EVENTUALLY PUSH THE LIGHT SNOW SHOWER ACTIVITY TO THE SOUTH. BY THIS AFTERNOON...THE FRONT WILL HAVE MADE IT INTO THE MID- ATLANTIC REGION. STRONG CAA AND NORTHWEST FLOW IN THE WAKE OF THE FRONT WILL KEEP THE AREA BLANKETED WITH CLOUDS. THERE LIKELY BE SOME LAKE EFFECT/ENHANCED SNOW SHOWERS DEVELOPING LATER TODAY. HOWEVER DO NOT THINK ACTIVITY WILL BE WIDESPREAD AS INVERSIONS DROP QUICKLY THIS AFTERNOON. WILL KEEP HIGHEST POPS OVER THE RIDGES AS THERE IS AN OROGRAPHIC COMPONENT THIS AFTERNOON. WITH THE STRONG CAA EXPECT STEADY TO SLOWLY FALLING TEMPS TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... FLOW ALOFT BEGINS TO WANE TONIGHT...BUT THE COLD AIR WILL CONTINUE TO PLUNGE INTO THE AREA. STRONG HIGH PRESSURE WILL MOVE ACROSS THE MIDWEST. WILL LEAVE IN CLOUDS OVERNIGHT...BUT WITH INVERSIONS SO LOW...ONLY EXPECT SNOW SHOWERS IN THE RIDGES. TEMPS OVERNIGHT WILL BE WELL BELOW NORMAL. SFC HIGH PRESSURE WILL MOVE FROM THE MIDWEST INTO THE OHIO VALLEY ON WED. THE CORE OF THE COLD POOL WILL BEGIN TO MOVE NORTHEASTWARD AS 85H RIDGES MOVE EASTWARD. STILL EXPECT LOTS OF CLOUDS WED...BUT THERE WILL BE SOME IMPROVEMENT IN THE AFTERNOON. TEMPS AGAIN...WELL BELOW NORMAL. ANOTHER SHORTWAVE TROUGH WILL SWING THROUGH LATE THURSDAY. WITH WINDS VEERING TO THE WEST-SOUTHWEST...TEMPS WILL MODERATE A BIT ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... GENERAL AGREEMENT IN THE MODELS ON THE OVERALL PATTERN THROUGH THE LONG TERM PD...ALTHOUGH PREFER GEFS/NAEFS FOR TIMING OF INDIVIDUAL FEATURES. A WK COLD FRONT WL MOVE ACRS THE RGN THU NT...HOWEVER DEEP MOISTURE IS CONFINED WELL TO THE NORTH. COULD SEE A FEW SHSN IN NW FLOW BEHIND THE FRONT BUT INVERSION SHOULD LIMIT DEPTH OF CLOUDS TO KEEP ACTIVITY MINIMAL...SO KEPT ONLY LOW CHC POPS N OF PIT. HIGH PRES BLDS IN SAT BEFORE ANOTHER WK FRONT PASSES THROUGH SAT NT...AGAIN WITH MOST OF THE MOISTURE STAYING NORTH. THIS SHOULD BRING MAINLY JUST AN INCREASE IN CLOUDS. HIGH PRES RIDGES BACK IN MON. TEMPS WL AVG BLW NORMAL MOST OF THE PD. OPERATIONAL MODELS WARM THINGS UP MON...BUT ENSEMBLES ARE NOT AS AGGRESSIVE. STAYED CLOSER TO COOLER ENSEMBLE MEANS. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/... RECENT SURFACE RADAR AND SATELLITE DATA COUPLED WITH RECENT RAP NAM AND SREF MODEL OUTPUT SHOW JETSTREAK-RELATED COLD FRONTAL BAND OF LIGHT IFR SNOW WILL CONTINUE TO PASS EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH ABOUT 17Z. POSTFRONTAL COLD POOL COUPLED WITH LAKE-MOISTENED WEST TO NORTHWEST SURFACE LAYER WINDS WILL MAINTAIN MVFR CONDITIONS INTO TONIGHT. ANY REMAINING PRECIPITATION...BE IT SNOW OR FREEZING DRIZZLE...WILL BE VERY LIGHT AS SURFACE MIXED LAYER WILL BE CAPPED AT 5 KFT AGL. SURFACE WINDS WILL GO FROM SOUTHWEST TO WEST AT 8 KTS THIS MORNING...TO NORTHWEST AT 10 KTS THIS AFTERNOON...THEN BECOME WESTERLY AT NO MORE THAN 6 KTS TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... COLD POOL MVFR STRATOCUMULUS WILL REMAIN THROUGH AT LEAST WEDNESDAY. HIGH PRESSURE SUBSIDENCE MAY PROMOTE A VFR BREAK THURSDAY BEFORE A COLD FRONT PROVIDES THE NEXT ROUND OF RESTRICTIONS FRIDAY AND SATURDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
646 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL PROVIDE THE RISK FOR SNOW SHOWERS THROUGH THE MORNING HOURS. MUCH COLDER AIR WILL SETTLE IN BEHIND THE FRONT BEGINNING THIS AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FRONT IS SLOWLY MOVING INTO NW PA AND WILL CONTINUE IT ARDUOUS TREK SOUTHWARD. LIGHT SNOW SHOWERS HAVE REDEVELOPED ON THE SOUTHERN FLANK OF THE BOUNDARY AS A STRONG UPPER LEVEL WAVE IS RUNNING ALONG THE NORTHERN SIDE OF THE FRONT AND PROVIDING LIFT. THIS WAVE WILL ALSO HELP TO GET THE FRONT MOVING SOUTHWARD...WHICH WILL EVENTUALLY PUSH THE LIGHT SNOW SHOWER ACTIVITY TO THE SOUTH. BY THIS AFTERNOON...THE FRONT WILL HAVE MADE IT INTO THE MID- ATLANTIC REGION. STRONG CAA AND NORTHWEST FLOW IN THE WAKE OF THE FRONT WILL KEEP THE AREA BLANKETED WITH CLOUDS. THERE LIKELY BE SOME LAKE EFFECT/ENHANCED SNOW SHOWERS DEVELOPING LATER TODAY. HOWEVER DO NOT THINK ACTIVITY WILL BE WIDESPREAD AS INVERSIONS DROP QUICKLY THIS AFTERNOON. WILL KEEP HIGHEST POPS OVER THE RIDGES AS THERE IS AN OROGRAPHIC COMPONENT THIS AFTERNOON. WITH THE STRONG CAA EXPECT STEADY TO SLOWLY FALLING TEMPS TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... FLOW ALOFT BEGINS TO WANE TONIGHT...BUT THE COLD AIR WILL CONTINUE TO PLUNGE INTO THE AREA. STRONG HIGH PRESSURE WILL MOVE ACROSS THE MIDWEST. WILL LEAVE IN CLOUDS OVERNIGHT...BUT WITH INVERSIONS SO LOW...ONLY EXPECT SNOW SHOWERS IN THE RIDGES. TEMPS OVERNIGHT WILL BE WELL BELOW NORMAL. SFC HIGH PRESSURE WILL MOVE FROM THE MIDWEST INTO THE OHIO VALLEY ON WED. THE CORE OF THE COLD POOL WILL BEGIN TO MOVE NORTHEASTWARD AS 85H RIDGES MOVE EASTWARD. STILL EXPECT LOTS OF CLOUDS WED...BUT THERE WILL BE SOME IMPROVEMENT IN THE AFTERNOON. TEMPS AGAIN...WELL BELOW NORMAL. ANOTHER SHORTWAVE TROUGH WILL SWING THROUGH LATE THURSDAY. WITH WINDS VEERING TO THE WEST-SOUTHWEST...TEMPS WILL MODERATE A BIT ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... GENERAL AGREEMENT IN THE MODELS ON THE OVERALL PATTERN THROUGH THE LONG TERM PD...ALTHOUGH PREFER GEFS/NAEFS FOR TIMING OF INDIVIDUAL FEATURES. A WK COLD FRONT WL MOVE ACRS THE RGN THU NT...HOWEVER DEEP MOISTURE IS CONFINED WELL TO THE NORTH. COULD SEE A FEW SHSN IN NW FLOW BEHIND THE FRONT BUT INVERSION SHOULD LIMIT DEPTH OF CLOUDS TO KEEP ACTIVITY MINIMAL...SO KEPT ONLY LOW CHC POPS N OF PIT. HIGH PRES BLDS IN SAT BEFORE ANOTHER WK FRONT PASSES THROUGH SAT NT...AGAIN WITH MOST OF THE MOISTURE STAYING NORTH. THIS SHOULD BRING MAINLY JUST AN INCREASE IN CLOUDS. HIGH PRES RIDGES BACK IN MON. TEMPS WL AVG BLW NORMAL MOST OF THE PD. OPERATIONAL MODELS WARM THINGS UP MON...BUT ENSEMBLES ARE NOT AS AGGRESSIVE. STAYED CLOSER TO COOLER ENSEMBLE MEANS. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... RECENT SURFACE RADAR AND SATELLITE DATA COUPLED WITH RECENT RAP NAM AND SREF MODEL OUTPUT SHOW JETSTREAK-RELATED COLD FRONTAL BAND OF LIGHT IFR SNOW WILL CONTINUE TO PASS EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH ABOUT 17Z. POSTFRONTAL COLD POOL COUPLED WITH LAKE-MOISTENED WEST TO NORTHWEST SURFACE LAYER WINDS WILL MAINTAIN MVFR CONDITIONS INTO TONIGHT. ANY REMAINING PRECIPITATION...BE IT SNOW OR FREEZING DRIZZLE...WILL BE VERY LIGHT AS SURFACE MIXED LAYER WILL BE CAPPED AT 5 KFT AGL. SURFACE WINDS WILL GO FROM SOUTHWEST TO WEST AT 8 KTS THIS MORNING...TO NORTHWEST AT 10 KTS THIS AFTERNOON...THEN BECOME WESTERLY AT NO MORE THAN 6 KTS TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... COLD POOL MVFR STRATOCUMULUS WILL REMAIN THROUGH AT LEAST WEDNESDAY. HIGH PRESSURE SUBSIDENCE MAY PROMOTE A VFR BREAK THURSDAY BEFORE A COLD FRONT PROVIDES THE NEXT ROUND OF RESTRICTIONS FRIDAY AND SATURDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
421 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL PROVIDE THE RISK FOR SNOW SHOWERS THROUGH THE MORNING HOURS. MUCH COLDER AIR WILL SETTLE IN BEHIND THE FRONT BEGINNING THIS AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FRONT IS SLOWLY MOVING INTO NW PA AND WILL CONTINUE IT ARDUOUS TREK SOUTHWARD. LIGHT SNOW SHOWERS HAVE REDEVELOPED ON THE SOUTHERN FLANK OF THE BOUNDARY AS A STRONG UPPER LEVEL WAVE IS RUNNING ALONG THE NORTHERN SIDE OF THE FRONT AND PROVIDING LIFT. THIS WAVE WILL ALSO HELP TO GET THE FRONT MOVING SOUTHWARD...WHICH WILL EVENTUALLY PUSH THE LIGHT SNOW SHOWER ACTIVITY TO THE SOUTH. BY THIS AFTERNOON...THE FRONT WILL HAVE MADE IT INTO THE MID- ATLANTIC REGION. STRONG CAA AND NORTHWEST FLOW IN THE WAKE OF THE FRONT WILL KEEP THE AREA BLANKETED WITH CLOUDS. THERE LIKELY BE SOME LAKE EFFECT/ENHANCED SNOW SHOWERS DEVELOPING LATER TODAY. HOWEVER DO NOT THINK ACTIVITY WILL BE WIDESPREAD AS INVERSIONS DROP QUICKLY THIS AFTERNOON. WILL KEEP HIGHEST POPS OVER THE RIDGES AS THERE IS AN OROGRAPHIC COMPONENT THIS AFTERNOON. WITH THE STRONG CAA EXPECT STEADY TO SLOWLY FALLING TEMPS TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... FLOW ALOFT BEGINS TO WANE TONIGHT...BUT THE COLD AIR WILL CONTINUE TO PLUNGE INTO THE AREA. STRONG HIGH PRESSURE WILL MOVE ACROSS THE MIDWEST. WILL LEAVE IN CLOUDS OVERNIGHT...BUT WITH INVERSIONS SO LOW...ONLY EXPECT SNOW SHOWERS IN THE RIDGES. TEMPS OVERNIGHT WILL BE WELL BELOW NORMAL. SFC HIGH PRESSURE WILL MOVE FROM THE MIDWEST INTO THE OHIO VALLEY ON WED. THE CORE OF THE COLD POOL WILL BEGIN TO MOVE NORTHEASTWARD AS 85H RIDGES MOVE EASTWARD. STILL EXPECT LOTS OF CLOUDS WED...BUT THERE WILL BE SOME IMPROVEMENT IN THE AFTERNOON. TEMPS AGAIN...WELL BELOW NORMAL. ANOTHER SHORTWAVE TROUGH WILL SWING THROUGH LATE THURSDAY. WITH WINDS VEERING TO THE WEST-SOUTHWEST...TEMPS WILL MODERATE A BIT ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... GENERAL AGREEMENT IN THE MODELS ON THE OVERALL PATTERN THROUGH THE LONG TERM PD...ALTHOUGH PREFER GEFS/NAEFS FOR TIMING OF INDIVIDUAL FEATURES. A WK COLD FRONT WL MOVE ACRS THE RGN THU NT...HOWEVER DEEP MOISTURE IS CONFINED WELL TO THE NORTH. COULD SEE A FEW SHSN IN NW FLOW BEHIND THE FRONT BUT INVERSION SHOULD LIMIT DEPTH OF CLOUDS TO KEEP ACTIVITY MINIMAL...SO KEPT ONLY LOW CHC POPS N OF PIT. HIGH PRES BLDS IN SAT BEFORE ANOTHER WK FRONT PASSES THROUGH SAT NT...AGAIN WITH MOST OF THE MOISTURE STAYING NORTH. THIS SHOULD BRING MAINLY JUST AN INCREASE IN CLOUDS. HIGH PRES RIDGES BACK IN MON. TEMPS WL AVG BLW NORMAL MOST OF THE PD. OPERATIONAL MODELS WARM THINGS UP MON...BUT ENSEMBLES ARE NOT AS AGGRESSIVE. STAYED CLOSER TO COOLER ENSEMBLE MEANS. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... RECENT SURFACE RADAR AND SATELLITE DATA COUPLED WITH RECENT RAP NAM AND SREF MODEL OUTPUT SHOW JETSTREAK-RELATED COLD FRONTAL BAND OF LIGHT IFR SNOW WILL CONTINUE TO PASS EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH 13Z. POSTFRONTAL COLD POOL COUPLED WITH LAKE-MOISTENED WEST TO NORTHWEST SURFACE LAYER WINDS WILL MAINTAIN MVFR CONDITIONS INTO TONIGHT. ANY REMAINING PRECIPITATION...BE IT SNOW OR FREEZING DRIZZLE...WILL BE VERY LIGHT AS SURFACE MIXED LAYER WILL BE CAPPED AT 5 KFT AGL. SURFACE WINDS WILL BE SOUTHWEST TO WEST AT 12 KTS THROUGH 14Z...THEN BE MORE WEST TO NORTHWEST AT 10 KTS THE REST OF TODAY AND TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... COLD POOL MVFR STRATOCUMULUS WILL REMAIN THROUGH AT LEAST WEDNESDAY. HIGH PRESSURE SUBSIDENCE MAY PROMOTE A VFR BREAK THURSDAY BEFORE A COLD FRONT PROVIDES THE NEXT ROUND OF RESTRICTIONS FRIDAY AND SATURDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
112 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL PROVIDE THE RISK FOR SNOW SHOWERS THROUGH THE MORNING HOURS. MUCH COLDER AIR WILL SETTLE IN BEHIND THE FRONT BEGINNING THIS AFTERNOON. && .NEAR TERM /THROUGH TODAY/... FRONT IS SLOWLY CROSSING LAKE ERIE AND WILL CONTINUE IT ARDUOUS TREK SOUTHWARD. MUCH OF THE LIGHT SNOW ACTIVITY HAS DISSIPATED AS THE UPPER LEVEL WAVE IS NOW OVER EASTERN PA. LATEST HI-RES MODELS ARE INDICATING THAT ANOTHER AREA OF SNOW SHOWERS WILL DEVELOP ALONG THE FRONT LATER TONIGHT. IT APPEARS THAT MOST OF THIS NEW DEVELOPMENT WILL BE OVER THE SOUTHERN HALF OF THE FORECAST AREA. SNOW SHOWERS ACTIVITY WILL CONTINUE TO BE PUSHED SOUTHWARD THIS MORNING AS THE FRONT MOVES INTO NORTHERN WV. BY THIS AFTERNOON...THE FRONT WILL HAVE MADE IT INTO THE MID- ATLANTIC REGION. STRONG CAA AND NORTHWEST FLOW IN THE WAKE OF THE FRONT WILL KEEP THE AREA BLANKETED WITH CLOUDS. THERE LIKELY BE SOME LAKE EFFECT/ENHANCED SNOW SHOWERS DEVELOPING LATER TODAY. HOWEVER DO NOT THINK ACTIVITY WILL BE WIDESPREAD AS INVERSIONS DROP QUICKLY THIS AFTERNOON. WILL KEEP HIGHEST POPS OVER THE RIDGES AS THERE IS AN OROGRAPHIC COMPONENT THIS AFTERNOON. WITH THE STRONG CAA EXPECT STEADY TO SLOWLY FALLING TEMPS TODAY. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... FLOW ALOFT BEGINS TO WANE TONIGHT...BUT THE COLD AIR WILL CONTINUE TO PLUNGE INTO THE AREA. STRONG HIGH PRESSURE WILL MOVE ACROSS THE MIDWEST. WILL LEAVE IN CLOUDS OVERNIGHT...BUT WITH INVERSIONS SO LOW...ONLY EXPECT SNOW SHOWERS IN THE RIDGES. TEMPS OVERNIGHT WILL BE WELL BELOW NORMAL. SFC HIGH PRESSURE WILL MOVE FROM THE MIDWEST INTO THE OHIO VALLEY ON WED. THE CORE OF THE COLD POOL WILL BEGIN TO MOVE NORTHEASTWARD AS 85H RIDGES MOVE EASTWARD. STILL EXPECT LOTS OF CLOUDS WED...BUT THERE WILL BE SOME IMPROVEMENT IN THE AFTERNOON. TEMPS AGAIN...WELL BELOW NORMAL. ANOTHER SHORTWAVE TROUGH WILL SWING THROUGH LATE THURSDAY. WITH WINDS VEERING TO THE WEST-SOUTHWEST...TEMPS WILL MODERATE A BIT ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... GENERAL AGREEMENT IN THE MODELS ON THE OVERALL PATTERN THROUGH THE LONG TERM PD...ALTHOUGH PREFER GEFS/NAEFS FOR TIMING OF INDIVIDUAL FEATURES. A WK COLD FRONT WL MOVE ACRS THE RGN THU NT...HOWEVER DEEP MOISTURE IS CONFINED WELL TO THE NORTH. COULD SEE A FEW SHSN IN NW FLOW BEHIND THE FRONT BUT INVERSION SHOULD LIMIT DEPTH OF CLOUDS TO KEEP ACTIVITY MINIMAL...SO KEPT ONLY LOW CHC POPS N OF PIT. HIGH PRES BLDS IN SAT BEFORE ANOTHER WK FRONT PASSES THROUGH SAT NT...AGAIN WITH MOST OF THE MOISTURE STAYING NORTH. THIS SHOULD BRING MAINLY JUST AN INCREASE IN CLOUDS. HIGH PRES RIDGES BACK IN MON. TEMPS WL AVG BLW NORMAL MOST OF THE PD. OPERATIONAL MODELS WARM THINGS UP MON...BUT ENSEMBLES ARE NOT AS AGGRESSIVE. STAYED CLOSER TO COOLER ENSEMBLE MEANS. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... RECENT SURFACE RADAR AND SATELLITE DATA COUPLED WITH RECENT RAP NAM AND SREF MODEL OUTPUT SHOW JETSTREAK-RELATED COLD FRONTAL BAND OF LIGHT IFR SNOW WILL PASS EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH 13Z. POSTFRONTAL COLD POOL COUPLED WITH LAKE-MOISTENED WEST TO NORTHWEST SURFACE LAYER WINDS WILL MAINTAIN MVFR CONDITIONS INTO TONIGHT. NAM MODEL PROFILES SHOW THE SURFACE MIXED LAYER WILL BE CAPPED AT 5 KFT AGL WITH CLOUD TOP TEMPERATURES POSSIBLY WARMER THAN -10C. SO ANY REMAINING PRECIPITATION WILL BE VERY LIGHT...BE IT VERY LIGHT SNOW OR VERY LIGHT FREEZING DRIZZLE. SURFACE WINDS WILL BE SOUTHWEST TO WEST AT 12 KTS THROUGH 14Z...THEN BE MORE WEST TO NORTHWEST AT 10 KTS THE REST OF TODAY AND TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... COLD POOL MVFR STRATOCUMULUS WILL REMAIN THROUGH AT LEAST WEDNESDAY. HIGH PRESSURE SUBSIDENCE MAY PROMOTE A VFR BREAK THURSDAY BEFORE A COLD FRONT PROVIDES THE NEXT ROUND OF RESTRICTIONS FRIDAY AND SATURDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
513 AM CST TUE JAN 1 2013 .DISCUSSION... OVERVIEW...NEAR TO BELOW NORMAL TEMPS THIS WEEK. LIGHT SNOW EVENT STILL ON TAP FOR WEDNESDAY WHERE WE HAVE LIKELY TO CATEGORICAL POPS FOR LIGHT SNOW. STRATUS OVER WESTERN MN CONTINUES TO THE EAST AT 10 KTS SO TRIED TO TREND TEMPERATURES...DEWPOINTS...AND SKY COVER ACCORDINGLY. WIND HAS WEAKENED QUITE A BIT OVERNIGHT WITH THE HIGH BUILDING IN AND WIND CHILLS WILL LIKELY NOT REACH 25 BELOW. BY SUNRISE A RETURN FLOW COULD PRODUCE A 3-5 KT WIND AGAIN... SO WILL MAINTAIN THE WIND CHILL ADVISORY IN MOST AREAS AND SIMPLY TRIM THE ADVISORY WHERE CLOUDS HAVE ARRIVED. MOISTURE WITH THE NEXT SFC-MID LEVEL TROUGH SPREADS SOUTHEAST ACROSS THE FORECAST AREA ON WEDNESDAY. WHAT LOWER LEVEL THERMO-DYNAMIC FORCING THERE IS MOSTLY MOVES ACROSS THE AREA BEFORE THE DEEPER MOISTURE ARRIVES. MODELS SHOW THE COLUMN SATURATES TO AT LEAST 700MB THRU THU AFTERNOON/EVENING WITH AND AHEAD OF THE PASSING SFC-MID LEVEL TROUGH AXIS. MODEL CONSENSUS DOES HAVE SOME 500-300MB PV ADVECTION MOVING ACROSS THE AREA CENTERED ON 00Z THU ALONG WITH SOME WEAK 700-500MB QG CONVERGENCE. GIVEN THE MOISTURE SIGNAL...THE WEAK QG CONVERGENCE...RATHER DEEP CYCLONIC FLOW FOR CONVERGENCE AND SOME PV ADVECTION/DIVERGENCE ALOFT...MAINTAINED TREND OF VERY LIGHT SNOW LIKELY. SNOW AMOUNTS FROM THIS SYSTEM STILL LOOK LIKE A DUSTING UP TO ONE INCH. WITH SOME SFC-700MB MOISTURE AND CYCLONIC FLOW/CONVERGENCE LINGERING LATER WED NIGHT...ADDED MENTION OF SCT FLURRIES TO 06Z-12Z THU FCST GRIDS. Q-VECTOR DIVERGENCE SPREADS ACROSS THE AREA THURSDAY. LOWER LEVEL COLD ADVECTION WED NIGHT/MUCH OF THU SENDS 925MB TEMPS BACK INTO THE -11C TO -14C RANGE FOR THU AFTERNOON. TEMPS LOOKING TO END UP NEARLY STEADY ON THU. WITH THE MORE PROGRESSIVE TROUGH AND MID LEVEL RIDGING BUILDING EAST INTO THE UPPER MIDWEST...STRONG 925-850MB WARM ADVECTION SPREADS ACROSS MN/IA/WI THU NIGHT. IN THE EXTENDED...THE CONUS REMAINS IN A SPLIT-FLOW PATTERN ALOFT. THE PRIMARY SHORTWAVE ENERGY EMBEDDED WITHIN THE MILDER NORTHERN STREAM MIGRATES ACROSS SOUTHERN CANADA...EXITING THE NORTH AMERICAN CONTINENT BETWEEN 45-50N LATITUDE AND OCCASIONALLY MIXING WITH AN ARCTIC BOUNDARY IN PLACE. THE OPERATIONAL GFS/ECMWF GENERALLY HANDLE THE INDIVIDUAL WAVES ALONG THE US/CANADIAN BORDER WITH LITTLE EXCITEMENT. AT LEAST THROUGH THE WEEKEND...A BLEND OF THE THE GFS/EC OFFER GUIDANCE FOR A GRADUAL WARMUP WORKING WEST- TO-EAST ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI. && .AVIATION.../06Z TAF ISSUANCE/ CANADIAN HIGH PRESSURE CENTERED OVER SOUTHERN MINNESOTA HAS LED TO CLEAR SKIES AND NEARLY CALM WINDS ACROSS ALL THE TAF SITES LATE THIS EVENING. WIDESPREAD MVFR STRATUS ON THE BACK SIDE OF THE RIDGE OVER THE DAKOTAS HAS BEEN INCHING EASTWARD INTO SWRN MN DURING THE PAST COUPLE OF HOURS. MODELS REMAIN AT ODDS WITH THE EVOLUTION OF THIS STRATUS WITH SOME SHOWING IT REMAINING TO THE WEST AND OTHERS SHOWING IT BUILDING EASTWARD OVERNIGHT AND TUESDAY BEHIND THE RIDGE. WILL SIDE WITH THE PREVIOUS FORECAST AND BUILD IT EASTWARD THROUGH THE PERIOD GIVEN THE GOOD REPRESENTATION OF CURRENT CLOUD COVER THOSE MODELS HAVE AT THE PRESENT TIME. KMSP...BIGGEST CONCERNS WILL BE WHETHER THE STRATUS TO THE WEST CAN MAKE IT AS FAR EAST AS MSP AND WHEN IT WOULD ARRIVE. SIMPLE EXTRAPOLATION OF CURRENT TRENDS WOULDN/T BRING THE CLOUDS IN UNTIL TUESDAY EVENING. HOWEVER...THINK EASTWARD EXPANSION WILL ACCELERATE AS THE RIDGE PUSHES TO THE SOUTH SO FAVORED TIMING OF THE PREVIOUS FORECAST AND OF THE RAP MODEL. FORECAST SOUNDINGS SHOW GOOD SATURATION BETWEEN 020-030...SO INTRODUCED MVFR CIGS FOR TUESDAY AFTERNOON INTO EVENING. /OUTLOOK FOR KMSP/ WED...MVFR CONDITIONS/-SN POSSIBLE. WSW WINDS 4 TO 8 KTS. THU...MVFR CEILINGS/FLURRIES POSSIBLE. NW WINDS 8 TO 12 KTS. FRI...VFR. WINDS SW 5 TO 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON-BLUE EARTH-BROWN-CHIPPEWA-DOUGLAS-FARIBAULT-FREEBORN-GOODHUE- ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN- MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-REDWOOD- RENVILLE-RICE-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT- TODD-WASECA-WATONWAN-WRIGHT-YELLOW MEDICINE. WI...NONE. && $$ CLF/BB
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1201 AM CST TUE JAN 1 2013 .UPDATE... UPDATED FOR AVIATION DISCUSSION BELOW. && .PREV DISCUSSION.../ISSUED 836 PM CST MON DEC 31 2012/ UPDATE... TEMPERATURES AT 8 PM HAVE ALREADY FALLEN TO BETWEEN 5 AND 10 BELOW ZERO ACROSS WRN MN...WITH SINGLE DIGITS ABOVE ZERO FURTHER EAST ACROSS THE TWIN CITIES METRO AND WRN WI. THE RIDGE IS CENTERED OVER WRN MN ATTM AND IS EXPECTED TO CONTINUE BUILDING SEWD TO SCTRL MN BY DAWN. A BANK OF STRATUS OVER SD HAS INCHED ITS WAY EWD TO THE MN STATE LINE. TEMPERATURES WARMED SEVERAL DEGREES OVER ERN SD AS THIS STRATUS MOVED OVERHEAD. THUS...COULD SEE TEMPS MODERATE OVERNIGHT ACROSS FAR WRN MN AS THIS STRATUS MOVES IN. JUST A BIT FURTHER EAST...IDEAL RADIATIONAL CONDITIONS WILL PERSIST DIRECTLY UNDER THE RIDGE AND TEMPERATURES ARE EXPECTED TO PLUMMET TO 15 TO 20 BELOW IN MANY PLACES. WINDS MAY REMAIN JUST ELEVATED ENOUGH OVER WRN WI TO PREVENT FROM REACHING 10 BELOW. THE URBAN HEAT ISLAND OF THE METRO WILL ALSO KEEP TEMPERATURES IN THE SINGLE DIGITS BELOW THERE. WIND HAS WEAKENED QUITE A BIT IN THE PAST COUPLE HOURS AND THERE ARE DOUBTS THAT WIDESPREAD WIND CHILLS WILL REACH 25 BELOW. HOWEVER...BY DAWN A RETURN FLOW WILL BEGIN WITH WINDS REACHING 5 KTS AGAIN. WITH SUCH COLD CONDITIONS IN PLACE...IT WON/T TAKE MUCH WIND TO OCCASIONALLY REACH WIND CHILLS OF 25 BELOW SO WILL MAINTAIN THE WIND CHILL ADVISORY. BORGHOFF && .PREV DISCUSSION.../ISSUED 257 PM CST MON DEC 31 2012/ ANOTHER COLD NIGHT TONIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. A WEAK CLIPPER SYSTEM WILL BRING SOME LIGHT SNOW ON WEDNESDAY...BUT ACCUMULATIONS WILL BE LIGHT. THE REST OF THE FORECAST WILL BE DRY...WITH A WARM UP EXPECTED THIS WEEKEND WITH HIGH TEMPERATURES APPROACHING THE THAWING MARK FOR SUNDAY AND MONDAY. TODAY THROUGH WEDNESDAY...THE TWO MAIN CHALLENGES WERE LOW TEMPERATURES TONIGHT...AND HOW TO BEST CONVEY THE LIGHT PRECIP ON WEDNESDAY. FIRST OF ALL...TONIGHTS LARGE SCALE SET UP IS IDEAL FOR NOCTURNAL COOLING AS THE SURFACE HIGH SLIDES SOUTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION. LIGHT WINDS...CLEAR SKIES...AND AMPLE SNOW COVER WILL ALLOW TEMPERATURES TO COOL OFF RATHER QUICKLY AFTER SUNSET. HAVE EXPANDED THE WIND CHILL ADVISORY ACROSS THE NORTH WHERE COULD SEE VALUES AROUND -25F OVERNIGHT. THE ONE CAVEAT...ASIDE FROM THE LIGHT WINDS...IS A SUBTLE SHORTWAVE ACROSS THE WESTERN DAKOTAS AND THE DOWNSTREAM CLOUDS ACROSS THE CENTRAL DAKOTAS...WHICH WILL HOLD UP TEMPERATURES IF THEY MOVE OVERHEAD TONIGHT. THESE WILL MOST LIKELY AFFECT SOUTHWEST MINNESOTA...BUT DID NOT CANCEL ANY OF THE WIND CHILL ADVISORY SINCE THERE IS STILL POTENTIAL FOR SUBSTANTIAL COOLING OVERNIGHT...AND IT IS NEW YEARS EVE. AFTER A CHILLY DRY TUESDAY...A WEAKENING SHORTWAVE WILL SPREAD A BROAD AREA OF UPWARD FORCING ACROSS THE REGION...AND FORECAST SOUNDINGS SHOW SATURATION WITH WEAK LIFT...WHICH SHOULD BE ENOUGH TO PRODUCE LIGHT SNOW ON WEDNESDAY. LIQUID AMOUNTS WILL BE ON THE ORDER OF A COUPLE OF HUNDREDTHS OR SO...BUT RATIOS SHOULD BE NEAR 20:1. THEREFORE HAVE SNOWFALL TOTALS OF AROUND A HALF INCH TO A INCH FOR WEDNESDAY...WITH LIKELY POPS. THE UPSTREAM WAVE BREAKING TO THE NORTH...AND STRONG ZONAL JET ACROSS THE OHIO RIVER VALLEY WILL SHEAR OUT THIS SYSTEM...SO IT WILL BECOME LESS ORGANIZED AS IT TRAVERSES THE REGION. HOWEVER...DECIDED TO GO WITH LIKELY POPS...SINCE IT WILL SNOW ON WEDNESDAY...BUT HAVE LIGHT QPF AMOUNTS SINCE MEASURABLE PRECIP IS STILL SOMEWHAT QUESTIONABLE. THURSDAY THROUGH MONDAY...TOWARDS THE END OF THE WEEK THE UPPER LEVEL FLOW WILL TRANSITION FROM NORTHWESTERLY TO MORE WESTERLY ACROSS THE MONTANA/CANADA BORDER. THIS WILL LEAD TO SIGNIFICANT LEE SIDE WARMING OVER THE HIGH PLAINS...WHICH WILL BE ADVECTED ACROSS THE REGION FOR THE WEEKEND. H900 TEMPERATURES OF +3 TO +5C WILL SET THE STAGE FOR A WARM UP ON SUNDAY AND MONDAY. FOR NOW IT APPEARS THE LOW LEVEL INVERSION WILL MITIGATE ANY SIGNIFICANT SNOW MELT...BUT SHOULD SEE TEMPERATURES APPROACH THE 32F MARK. A FEW WEAK WAVES TRACK ACROSS THE NORTH...BUT FOR NOW HAVE LEFT THE EXTENDED FORECAST DRY. && .AVIATION.../06Z TAF ISSUANCE/ CANADIAN HIGH PRESSURE CENTERED OVER SOUTHERN MINNESOTA HAS LED TO CLEAR SKIES AND NEARLY CALM WINDS ACROSS ALL THE TAF SITES LATE THIS EVENING. WIDESPREAD MVFR STRATUS ON THE BACK SIDE OF THE RIDGE OVER THE DAKOTAS HAS BEEN INCHING EASTWARD INTO SWRN MN DURING THE PAST COUPLE OF HOURS. MODELS REMAIN AT ODDS WITH THE EVOLUTION OF THIS STRATUS WITH SOME SHOWING IT REMAINING TO THE WEST AND OTHERS SHOWING IT BUILDING EASTWARD OVERNIGHT AND TUESDAY BEHIND THE RIDGE. WILL SIDE WITH THE PREVIOUS FORECAST AND BUILD IT EASTWARD THROUGH THE PERIOD GIVEN THE GOOD REPRESENTATION OF CURRENT CLOUD COVER THOSE MODELS HAVE AT THE PRESENT TIME. KMSP...BIGGEST CONCERNS WILL BE WHETHER THE STRATUS TO THE WEST CAN MAKE IT AS FAR EAST AS MSP AND WHEN IT WOULD ARRIVE. SIMPLE EXTRAPOLATION OF CURRENT TRENDS WOULDN/T BRING THE CLOUDS IN UNTIL TUESDAY EVENING. HOWEVER...THINK EASTWARD EXPANSION WILL ACCELERATE AS THE RIDGE PUSHES TO THE SOUTH SO FAVORED TIMING OF THE PREVIOUS FORECAST AND OF THE RAP MODEL. FORECAST SOUNDINGS SHOW GOOD SATURATION BETWEEN 020-030...SO INTRODUCED MVFR CIGS FOR TUESDAY AFTERNOON INTO EVENING. /OUTLOOK FOR KMSP/ WED...MVFR CONDITIONS/-SN POSSIBLE. WSW WINDS 4 TO 8 KTS. THU...MVFR CEILINGS/FLURRIES POSSIBLE. NW WINDS 8 TO 12 KTS. FRI...VFR. WINDS SW 5 TO 10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND CHILL ADVISORY UNTIL 9 AM CST TUESDAY FOR BENTON-BLUE EARTH- BROWN-CHIPPEWA-DOUGLAS-FARIBAULT-FREEBORN-GOODHUE-ISANTI- KANABEC-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD- MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-REDWOOD-RENVILLE- RICE-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD- WASECA-WATONWAN-WRIGHT-YELLOW MEDICINE. WI...NONE. && $$ JRB/BORGHOFF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
126 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT BRINGING SCATTERED SNOW SHOWERS AND FLURRIES. LITTLE SNOW IS EXPECTED BUT OVER ONEIDA, ONONDAGA AND MADISON COUNTIES, 1 TO 3 INCHES IS POSSIBLE. LAKE EFFECT SNOW SHOWERS WILL DROP SOUTH ACROSS CENTRAL NEW YORK ON WEDNESDAY WHILE WEAKENING. ANOTHER FRONT WILL PUSH THROUGH THE REGION LATE TUESDAY NIGHT INTO WEDNESDAY MORNING BRINGING ANOTHER ROUND OF SCATTERED SNOW SHOWERS AND LAKE EFFECT SNOWS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1245 AM UPDATE... ORGANIZED LK BAND HAS DROPPED INTO NRN ONEIDA CNTY ATTM, JUST AHD OF THE SFC FRONT. KTYX VWP INDICATES FLOW IS ALIGNED FM 3KFT-9KFT OUT OF THE WEST AND THIS ACCNTS FOR THE MORE ORGANIZED NATURE OF THE BAND. THINKING IS THAT AS CDFNT DROPS THRU THE REGION, BAND WL BCM MORE DISORGANIZED WITH MINIMAL ACCUMS EXPECTED. HV UPDATED HRLY POPS AND WX GRIDS TO ACCNT FOR THE CURRENT RADAR TRENDS. ALSO ADJUSTED HRLY T/TD VALUES. PREV DISCOS BLO... 940 PM UPDATE... QUICK UPDATE TO ACCOUNT FOR LATEST TRENDS. LATEST RADAR DATA SHOWING A BAND OF SNOW EXTENDING EAST ACROSS THE SOUTHERN TIER THIS EVENING WITH SNOW JUST BEGINNING HERE AT THE AIRFIELD. IN ALL ACTUALITY...FAIRLY DECENT FORCING FOR ONGOING SNOWFALL AS REGION RESIDES UNDER THE LEFT EXIT REGION OF A 200+ KT UPPER JETSTREAK TO OUR SOUTH. THE 00Z KPIT SOUNDING MEASURED 180 KTS AT ROUGHLY 230-MB WHICH MAY BE ONE OF THE STRONGER JETS OF THE SEASON SO FAR. FURTHER TO OUR NORTH...A MID-LEVEL 500-MB JET ROUNDING THE BASE OF AN UPPER TROUGH ACROSS EASTERN ONTARIO IS ALSO PROVIDING A GLANCING BLOW WITH THE FCST AREA BECOMING MORE IN LINE WITH THE RIGHT ENTRANCE REGION OF THIS MID-LEVEL FEATURE. AND IF THAT WERE NOT ENOUGH...SFC FIELDS FROM THE RUC AND MSAS INDICATE A WEAK PRE- FRONTAL TROUGH AND MID-LEVEL VORT MAX APPROACHING FROM EASTERN OH. SO WHAT DOES THIS MEAN...WELL WE CAN EXPECT SNOW TO CONTINUE DEVELOPING OVERNIGHT AS MAIN COLD FRONT CONTINUES TO APPROACH. LATEST LOOK STILL SHOWS THE FRONT RESIDING TO THE WEST OF BUFFALO THIS EVENING WITH A NOTABLE TEMP INCREASE DETECTED DOWNSTREAM ACROSS OUR AREA. IN FACT...SEVERAL SITES HAVE SEEN A SLIGHT INCREASE IN TEMPS AS PRE-FRONTAL THERMAL RIDGING MOVES OVERHEAD. WILL HOLD OFF ON MAKING ANY WHOLESALE CHANGES TO OVERNIGHT LOWS AS COLD AIR ADVECTION FOLLOWING FROPA WILL ALLOW TEMPS TO COOL APPROPRIATELY. FOLLOWING FROPA...WINDS WILL BECOME ALIGNED ON A NORTHWESTERLY CONFIGURATION WHICH COMBINED WITH 850-MB TEMPS DROPPING TO NEAR -14C BY 12Z TUE...WILL RESULT IN DEVELOPING LAKE EFFECT SNOWS SOUTHEAST OF LAKE ONTARIO. WITH FLOW EXPECTED TO BE FAIRLY CHAOTIC IN NATURE...DEVELOPING BANDS WILL BE ON THE MOVE FOR A GOOD PORTION OF THE EARLY MORNING HRS WHICH SHOULD KEEP ACCUMULATIONS IN CHECK. NO ADDITIONAL CHANGES NEEDED FOR THE TIME BEING. 7 PM UPDATE... ONLY REAL CHANGE REQUIRED WAS TO DELAY SNOW INITIATION TIME AS MAIN COLD FRONT IS STILL POSITIONED ACROSS SOUTH-CENTRAL ONTARIO THIS HR. UPSTREAM RADAR TRENDS FROM KBUF BEGINNING TO SHOW SNOW SHOWER DEVELOPMENT ACROSS THE WESTERN SOUTHERN TIER WITH OLEAN NOW REPORTING LGT SNOW. THIS ACTIVITY APPEARS TO BE FROM A PRE-FRONTAL TROUGH MOVING EAST AHEAD OF THE PRIMARY FRONT. ALOFT...LATEST WATER VAPOR IMAGERY SHOWING VERY LITTLE SUPPORT ALOFT AS MAIN SHORTWAVE ENERGY LAGGING WELL TO THE WEST ACROSS EASTERN LAKE HURON. AS WE PROGRESS THROUGH THE OVERNIGHT...EXPECT SNOW SHWR ACTIVITY TO INCREASE IN COVERAGE AS AFOREMENTIONED FRONT AND PRE- FRONTAL TROUGH SHIFT EAST WITH TIME. FOLLOWING THEIR PASSAGE... LOW-LEVEL FLOW WILL BECOME ALIGNED TO SUPPORT DEVELOPING LAKE EFFECT ACROSS THE NORTHERN CWA WHERE A FEW INCHES OF NEW SNOW WILL BE POSSIBLE BY MORNING. ASIDE FROM THAT...NO SIGNIFICANT CHANGES REQUIRED AT THIS TIME. AT 4 PM...MID/HIGH LEVEL CLOUDS CONTINUE STREAMING ACROSS THE AREA UNDER SOUTHWEST FLOW. AFTERNOON TEMPS ARE CURRENTLY IN THE UPPER 20S TO MID 30S. SKIES WILL BECOME CLOUDY THIS EVENING AS A SFC TROF OVER SOUTHERN ONTARIO APPROACHES THE AREA WHILE MOISTURE ALSO INCREASES FROM THE SOUTH DUE TO A SYSTEM IN THE SOUTHERN PLAINS. AS THE SFC TROF STARTS DROPPING SOUTH THROUGH THE AREA LATER THIS EVENING LOW LEVEL FLOW WILL ALSO BECOME FAVORABLE FOR LAKE ENHANCEMENT. SHORTLY AFTER MIDNIGHT WENT WITH LIKELY POPS ACROSS THE FAR NRN CWA AND WITH LOW LEVEL FLOW CONTINUING TO VEER BAND OF HEAVIER ACTIVITY WILL CONTINUE DROPPING SOUTH THROUGH DAYBREAK. DUE TO BAND SHIFTING SOUTH WITH TIME, SNOW ACCUMS WILL REMAIN FAIRLY MINOR WITH 1 TO 3 INCHES POSSIBLE ACROSS ONONDAGA, MADISON AND ONEIDA COUNTIES. FOR THE REST OF THE REGION JUST SCATTERED SNOW SHOWERS AND FLURRIES ARE EXPECTED WITH ACCUMS WELL LESS THAN AN INCH. OVERNIGHT LOWS WILL RANGE IN THE 20S. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... TUESDAY...FOLLOWING THE FRONT, NORTHWEST FLOW WILL PERSIST OVER THE REGION WITH SCATTERED SNOW SHOWERS CONTINUING OVER CENTRAL NY UNDER 300/310 LOW LEVEL FLOW. ABUNDANT LOW LEVEL MOISTURE AND COLD AIR ADVECTION WILL BRING PLENTY OF CLOUDS AND TEMPS WILL STRUGGLE TO RISE JUST A FEW DEGREES FROM THE OVERNIGHT LOWS. TUESDAY NIGHT...LOW LEVEL FLOW WILL BACK IN RESPONSE TO NEXT SFC TROF DROPPING SOUTH FROM CANADA. ANY LINGERING SNOW SHOWERS WILL LIFT NORTH AND WEAKEN DURING THE EVENING HOURS. TOWARD DAYBREAK SFC TROF WILL EXTEND ACROSS LAKE ONTARIO BRINGING A FAVORABLE FLOW FOR THE EASTERN SHORE INTO NORTHERN ONEIDA COUNTY. WILL INCREASE POPS HERE TO LIKELY TOWARD DAYBREAK. WEDNESDAY...SFC TROF WILL SWING THROUGH AREA DURING THE MORNING HOURS WITH SFC HIGH PRES NOSING DOWN FROM EASTERN CANADA BY AFTERNOON. LOW LEVEL FLOW LOOKS FAVORABLE FOR LES ACROSS NRN CWA THROUGH MID MORNING WITH POSSIBLE GEORGIAN BAY CONNECTION BUT WITH FLOW CONTINUING TO VEER THIS SHOULD LIMIT SNOW ACCUM. BY AFTERNOON, 310 LOW LEVEL FLOW WILL KEEP THE MOST PERSISTENT SNOW SHOWERS ACROSS THE FINGER LAKES AND NORTHERN SUSQUEHANNA REGION. WED NIGHT/THURSDAY...ANOTHER SYSTEM MOVING THROUGH SOUTHERN CANADA WILL BACK LOW LEVEL FLOW PUSHING ANY LINGERING SNOW SHOWERS ACROSS CNTRL NY NORTH WHILE WEAKENING. ON THURSDAY, SFC TROF WILL CROSS NEARBY SOUTHERN ONTARIO BY LATE DAY BRINGING THE CHC FOR SNOW SHOWERS PRIMARILY IN THE NRN/WRN FA. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... 130 PM UPDATE... FAIRLY QUIET EXTENDED PERIOD WITH A FEW SHOTS AT LIGHT SNOWS BUT NO MAJOR STORMS IN THE OFFERING. FIRST SHOT AT SNOW COMES THURSDAY NIGHT INTO FRIDAY WITH A COLD FRONT AND REINFORCING SHOT OF COLD AIR. A FEW DAYS AGO THIS COLD PUSH WAS MUCH MORE IMPRESSIVE BUT IT NOW LOOKS LIKE THE CORE WILL STAY TO OUR NORTH INTO QUEBEC. STILL 850 TEMPS ON BOTH THE GFS AND EURO ARE IN THE MID TEENS BELOW ZERO WHICH WILL KEEP HIGHS IN THE 20S/NIGHTTIME LOWS IN THE TEENS WITH SOME SINGLE DIGITS POSSIBLE OVER OUR COLDER SECTIONS TO THE EAST. DESPITE NORTHWEST WINDS A SHOT OF LAKE EFFECT DOES NOT LOOK OVERLY IMPRESSIVE WITH DRY AIR BEING THE MAIN NEGATING FACTOR. BOTH THE GFS AND EURO SUGGEST TEMPS WARM UP A BIT SATURDAY...BEFORE ANOTHER SYSTEM BRINGS US LIGHT SNOW SATURDAY NIGHT INTO SUNDAY...WITH MORE SEASONABLE AIR. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... MVFR CIGS ARE EXPECTED TO BE THE GENERAL RESTRICTION CATEGORY EARLY THIS MORNING ACROSS THE UPSTATE NY TERMINALS WITH VFR OVER NORTHEAST PENNSYLVANIA. A BAND OF LAKE EFFECT SNOW WILL PASS QUICKLY THROUGH KRME AND INTO THE KSYR AREA PRIOR TO 09Z WITH OCCASIONAL IFR VSBY RESTRICTIONS. ELSEWHERE...AREAS OF LIGHT FLURRIES MAY BRING ADDITIONAL MVFR VSBY RESTRICTIONS TO KBGM AND KITH. THE SNOW BAND BECOMES A BROAD PLUME OF LIGHT SNOW SPREADING DOWNWIND THROUGH KSYR-KITH-KBGM THROUGH THE AFTERNOON...ALTHOUGH DRYING AND CONVECTIVE MIXING SHOULD HELP TO LIFT CIGS TO VFR WITH OCCASIONAL MINOR MVFR VSBY RESTRICTIONS WITHIN SNOW SHOWERS. FURTHER DRYING TONIGHT WILL ALLOW SNOW BAND TO RETRACT TOWARD THE LAKE AND BECOME MORE OF A WEST-EAST INFLUENCE AGAIN THROUGH KSYR-KRME AFT 00Z WITH RESTRICTIONS MAINLY EXPECTED TO BE MVFR. A RETURN TO VFR IS EXPECTED ELSEWHERE. WINDS SW 5-15 KTS BECOME NW 10G15 KTS BY 15Z...CONTINUING UNTIL THIS EVENING WHEN SPEEDS DIMINISH TO 5-10 KTS FROM THE NW. OUTLOOK... WED/WED NGT...OCCASIONAL MVFR/IFR FOR NY TERMINALS IN SNOW SHOWERS. THU THROUGH SAT...MAINLY VFR. RESTRICTIONS ARE POSSIBLE AT KRME/KSYR IN SNOW SHOWERS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...RRM NEAR TERM...CMG/PVN/RRM SHORT TERM...RRM LONG TERM...HEDEN AVIATION...JAB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1249 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT BRINGING SCATTERED SNOW SHOWERS AND FLURRIES. LITTLE SNOW IS EXPECTED BUT OVER ONEIDA, ONONDAGA AND MADISON COUNTIES, 1 TO 3 INCHES IS POSSIBLE. LAKE EFFECT SNOW SHOWERS WILL DROP SOUTH ACROSS CENTRAL NEW YORK ON WEDNESDAY WHILE WEAKENING. ANOTHER FRONT WILL PUSH THROUGH THE REGION LATE TUESDAY NIGHT INTO WEDNESDAY MORNING BRINGING ANOTHER ROUND OF SCATTERED SNOW SHOWERS AND LAKE EFFECT SNOWS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1245 AM UPDATE... ORGANIZED LK BAND HAS DROPPED INTO NRN ONEIDA CNTY ATTM, JUST AHD OF THE SFC FRONT. KTYX VWP INDICATES FLOW IS ALIGNED FM 3KFT-9KFT OUT OF THE WEST AND THIS ACCNTS FOR THE MORE ORGANIZED NATURE OF THE BAND. THINKING IS THAT AS CDFNT DROPS THRU THE REGION, BAND WL BCM MORE DISORGANIZED WITH MINIMAL ACCUMS EXPECTED. HV UPDATED HRLY POPS AND WX GRIDS TO ACCNT FOR THE CURRENT RADAR TRENDS. ALSO ADJUSTED HRLY T/TD VALUES. PREV DISCOS BLO... 940 PM UPDATE... QUICK UPDATE TO ACCOUNT FOR LATEST TRENDS. LATEST RADAR DATA SHOWING A BAND OF SNOW EXTENDING EAST ACROSS THE SOUTHERN TIER THIS EVENING WITH SNOW JUST BEGINNING HERE AT THE AIRFIELD. IN ALL ACTUALITY...FAIRLY DECENT FORCING FOR ONGOING SNOWFALL AS REGION RESIDES UNDER THE LEFT EXIT REGION OF A 200+ KT UPPER JETSTREAK TO OUR SOUTH. THE 00Z KPIT SOUNDING MEASURED 180 KTS AT ROUGHLY 230-MB WHICH MAY BE ONE OF THE STRONGER JETS OF THE SEASON SO FAR. FURTHER TO OUR NORTH...A MID-LEVEL 500-MB JET ROUNDING THE BASE OF AN UPPER TROUGH ACROSS EASTERN ONTARIO IS ALSO PROVIDING A GLANCING BLOW WITH THE FCST AREA BECOMING MORE IN LINE WITH THE RIGHT ENTRANCE REGION OF THIS MID-LEVEL FEATURE. AND IF THAT WERE NOT ENOUGH...SFC FIELDS FROM THE RUC AND MSAS INDICATE A WEAK PRE- FRONTAL TROUGH AND MID-LEVEL VORT MAX APPROACHING FROM EASTERN OH. SO WHAT DOES THIS MEAN...WELL WE CAN EXPECT SNOW TO CONTINUE DEVELOPING OVERNIGHT AS MAIN COLD FRONT CONTINUES TO APPROACH. LATEST LOOK STILL SHOWS THE FRONT RESIDING TO THE WEST OF BUFFALO THIS EVENING WITH A NOTABLE TEMP INCREASE DETECTED DOWNSTREAM ACROSS OUR AREA. IN FACT...SEVERAL SITES HAVE SEEN A SLIGHT INCREASE IN TEMPS AS PRE-FRONTAL THERMAL RIDGING MOVES OVERHEAD. WILL HOLD OFF ON MAKING ANY WHOLESALE CHANGES TO OVERNIGHT LOWS AS COLD AIR ADVECTION FOLLOWING FROPA WILL ALLOW TEMPS TO COOL APPROPRIATELY. FOLLOWING FROPA...WINDS WILL BECOME ALIGNED ON A NORTHWESTERLY CONFIGURATION WHICH COMBINED WITH 850-MB TEMPS DROPPING TO NEAR -14C BY 12Z TUE...WILL RESULT IN DEVELOPING LAKE EFFECT SNOWS SOUTHEAST OF LAKE ONTARIO. WITH FLOW EXPECTED TO BE FAIRLY CHAOTIC IN NATURE...DEVELOPING BANDS WILL BE ON THE MOVE FOR A GOOD PORTION OF THE EARLY MORNING HRS WHICH SHOULD KEEP ACCUMULATIONS IN CHECK. NO ADDITIONAL CHANGES NEEDED FOR THE TIME BEING. 7 PM UPDATE... ONLY REAL CHANGE REQUIRED WAS TO DELAY SNOW INITIATION TIME AS MAIN COLD FRONT IS STILL POSITIONED ACROSS SOUTH-CENTRAL ONTARIO THIS HR. UPSTREAM RADAR TRENDS FROM KBUF BEGINNING TO SHOW SNOW SHOWER DEVELOPMENT ACROSS THE WESTERN SOUTHERN TIER WITH OLEAN NOW REPORTING LGT SNOW. THIS ACTIVITY APPEARS TO BE FROM A PRE-FRONTAL TROUGH MOVING EAST AHEAD OF THE PRIMARY FRONT. ALOFT...LATEST WATER VAPOR IMAGERY SHOWING VERY LITTLE SUPPORT ALOFT AS MAIN SHORTWAVE ENERGY LAGGING WELL TO THE WEST ACROSS EASTERN LAKE HURON. AS WE PROGRESS THROUGH THE OVERNIGHT...EXPECT SNOW SHWR ACTIVITY TO INCREASE IN COVERAGE AS AFOREMENTIONED FRONT AND PRE- FRONTAL TROUGH SHIFT EAST WITH TIME. FOLLOWING THEIR PASSAGE... LOW-LEVEL FLOW WILL BECOME ALIGNED TO SUPPORT DEVELOPING LAKE EFFECT ACROSS THE NORTHERN CWA WHERE A FEW INCHES OF NEW SNOW WILL BE POSSIBLE BY MORNING. ASIDE FROM THAT...NO SIGNIFICANT CHANGES REQUIRED AT THIS TIME. AT 4 PM...MID/HIGH LEVEL CLOUDS CONTINUE STREAMING ACROSS THE AREA UNDER SOUTHWEST FLOW. AFTERNOON TEMPS ARE CURRENTLY IN THE UPPER 20S TO MID 30S. SKIES WILL BECOME CLOUDY THIS EVENING AS A SFC TROF OVER SOUTHERN ONTARIO APPROACHES THE AREA WHILE MOISTURE ALSO INCREASES FROM THE SOUTH DUE TO A SYSTEM IN THE SOUTHERN PLAINS. AS THE SFC TROF STARTS DROPPING SOUTH THROUGH THE AREA LATER THIS EVENING LOW LEVEL FLOW WILL ALSO BECOME FAVORABLE FOR LAKE ENHANCEMENT. SHORTLY AFTER MIDNIGHT WENT WITH LIKELY POPS ACROSS THE FAR NRN CWA AND WITH LOW LEVEL FLOW CONTINUING TO VEER BAND OF HEAVIER ACTIVITY WILL CONTINUE DROPPING SOUTH THROUGH DAYBREAK. DUE TO BAND SHIFTING SOUTH WITH TIME, SNOW ACCUMS WILL REMAIN FAIRLY MINOR WITH 1 TO 3 INCHES POSSIBLE ACROSS ONONDAGA, MADISON AND ONEIDA COUNTIES. FOR THE REST OF THE REGION JUST SCATTERED SNOW SHOWERS AND FLURRIES ARE EXPECTED WITH ACCUMS WELL LESS THAN AN INCH. OVERNIGHT LOWS WILL RANGE IN THE 20S. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... TUESDAY...FOLLOWING THE FRONT, NORTHWEST FLOW WILL PERSIST OVER THE REGION WITH SCATTERED SNOW SHOWERS CONTINUING OVER CENTRAL NY UNDER 300/310 LOW LEVEL FLOW. ABUNDANT LOW LEVEL MOISTURE AND COLD AIR ADVECTION WILL BRING PLENTY OF CLOUDS AND TEMPS WILL STRUGGLE TO RISE JUST A FEW DEGREES FROM THE OVERNIGHT LOWS. TUESDAY NIGHT...LOW LEVEL FLOW WILL BACK IN RESPONSE TO NEXT SFC TROF DROPPING SOUTH FROM CANADA. ANY LINGERING SNOW SHOWERS WILL LIFT NORTH AND WEAKEN DURING THE EVENING HOURS. TOWARD DAYBREAK SFC TROF WILL EXTEND ACROSS LAKE ONTARIO BRINGING A FAVORABLE FLOW FOR THE EASTERN SHORE INTO NORTHERN ONEIDA COUNTY. WILL INCREASE POPS HERE TO LIKELY TOWARD DAYBREAK. WEDNESDAY...SFC TROF WILL SWING THROUGH AREA DURING THE MORNING HOURS WITH SFC HIGH PRES NOSING DOWN FROM EASTERN CANADA BY AFTERNOON. LOW LEVEL FLOW LOOKS FAVORABLE FOR LES ACROSS NRN CWA THROUGH MID MORNING WITH POSSIBLE GEORGIAN BAY CONNECTION BUT WITH FLOW CONTINUING TO VEER THIS SHOULD LIMIT SNOW ACCUM. BY AFTERNOON, 310 LOW LEVEL FLOW WILL KEEP THE MOST PERSISTENT SNOW SHOWERS ACROSS THE FINGER LAKES AND NORTHERN SUSQUEHANNA REGION. WED NIGHT/THURSDAY...ANOTHER SYSTEM MOVING THROUGH SOUTHERN CANADA WILL BACK LOW LEVEL FLOW PUSHING ANY LINGERING SNOW SHOWERS ACROSS CNTRL NY NORTH WHILE WEAKENING. ON THURSDAY, SFC TROF WILL CROSS NEARBY SOUTHERN ONTARIO BY LATE DAY BRINGING THE CHC FOR SNOW SHOWERS PRIMARILY IN THE NRN/WRN FA. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... 130 PM UPDATE... FAIRLY QUIET EXTENDED PERIOD WITH A FEW SHOTS AT LIGHT SNOWS BUT NO MAJOR STORMS IN THE OFFERING. FIRST SHOT AT SNOW COMES THURSDAY NIGHT INTO FRIDAY WITH A COLD FRONT AND REINFORCING SHOT OF COLD AIR. A FEW DAYS AGO THIS COLD PUSH WAS MUCH MORE IMPRESSIVE BUT IT NOW LOOKS LIKE THE CORE WILL STAY TO OUR NORTH INTO QUEBEC. STILL 850 TEMPS ON BOTH THE GFS AND EURO ARE IN THE MID TEENS BELOW ZERO WHICH WILL KEEP HIGHS IN THE 20S/NIGHTTIME LOWS IN THE TEENS WITH SOME SINGLE DIGITS POSSIBLE OVER OUR COLDER SECTIONS TO THE EAST. DESPITE NORTHWEST WINDS A SHOT OF LAKE EFFECT DOES NOT LOOK OVERLY IMPRESSIVE WITH DRY AIR BEING THE MAIN NEGATING FACTOR. BOTH THE GFS AND EURO SUGGEST TEMPS WARM UP A BIT SATURDAY...BEFORE ANOTHER SYSTEM BRINGS US LIGHT SNOW SATURDAY NIGHT INTO SUNDAY...WITH MORE SEASONABLE AIR. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... 630 PM UPDATE... VFR CONTINUES BUT IT WONT LAST WITH MOISTURE COMING IN FROM THE WSW AND A COLD FRONT DROPPING SE FROM ONTARIO THIS EVENING. MVFR CIGS AS CLOSE AS THE LAKE PLAIN AT FULTON AND ROCHESTER. BY 5Z MVFR CIGS AND VSBYS IN LIGHT SNOW WILL BE ACROSS THE NY SITES. KAVP WILL REMAIN VFR THROUGH TUESDAY. SNOW SHOWER COVERAGE WILL PEAK 6 TO 9Z WITH THE FRONT. IFR VSBY POSSIBLE DURING THIS TIME AT RME AND SYR. AFTER THAT LAKE EFFECT WILL KICK IN KEEPING THE MVFR GOING INTO TUE MORNING. AROUND 15Z SOME IMPROVEMENT BUT WITH NW FLOW SYR MAY BE IN MVFR ALL DAY. REST OF NY SITES MAY BE IN AND OUT OF MVFR DURING THE AFTN. INVERSION LEVEL...MOISTURE AND DENDRITE LAYERS LOWER DURING THE AFTN SO THE SNOW SHOWERS WILL DIMINISH IN INTENSITY AND COVERAGE. SW FLOW AT 5 TO 10 KTS SHIFTING TO W AROUND 5Z...THEN NW AT 10 KTS LATE TONIGHT THROUGH TUESDAY. OUTLOOK... TUE NGT TO WED NGT...OCCASIONAL MVFR/IFR FOR NY TERMINALS IN SNOW SHOWERS. THU THROUGH SAT...MAINLY VFR. RESTRICTIONS ARE POSSIBLE AT KRME/KSYR IN SNOW SHOWERS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...RRM NEAR TERM...CMG/PVN/RRM SHORT TERM...RRM LONG TERM...HEDEN AVIATION...TAC
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
524 PM CST WED JAN 2 2013 .AVIATION... VFR CONDITIONS EXPECTED AT ALL SITES ALONG AND WEST OF THE VALLEY. THE EXCEPTION WILL BE KBJI...CURRENTLY (23Z) OVC006. 925MB WINDS REMAIN DUE NORTH THROUGH MUCH OF THE NIGHT...AND 21Z RAP INDICATES THESE CIGS WILL CONTINUE UNTIL 925MB WINDS BECOME MORE WESTERLY (AFTER 12Z). 00Z TAF ISSUANCE WILL FORECAST KBJI MORE PESSIMISTIC THAN 18Z TAF ISSUANCE. && .PREV DISCUSSION... /ISSUED 229 PM CST WED JAN 2 2013/ SHORT TERM... AFTER THE LIGHT SNOW WITH THE CURRENT SYSTEM MOVES OFF TO THE EAST CLOUDS AND TEMPS WILL BE THE MAIN FORECAST ISSUE. WILL STICK PRETTY CLOSE TO CONTINUITY FOR THIS PORTION OF THE FORECAST. TONIGHT...WINDS HAVE SWITCHED OVER TO THE NORTHWEST JUST ABOUT EVERYWHERE NOW WITH THE EXCEPTION OF A FEW SITES IN THE FAR EASTERN FA. AS THE SFC LOW CONTINUES TO MOVE OFF TO THE EAST TONIGHT AND RIDGING STARTS TO REPLACE IT WINDS SHOULD STAY NW AND THEN SHIFT TO THE WEST IN SOME PLACES LATE. THERE IS A CLEAR WEDGE WORKING DOWN THRU EASTERN ND NOW SO IT SHOULD START OFF FAIRLY CLEAR IN THE WEST WITH MORE CLOUDS IN THE EAST. EXPECT TO SEE WARM ADVECTION KICK IN TONIGHT WITH MORE HIGH LEVEL CLOUDS ALREADY MOVING INTO SOUTHERN CANADA. THEREFORE DOUBT IT WILL BE COMPLETELY CLEAR ANYWHERE TONIGHT BUT WILL HAVE SOME THIN CIRRUS AROUND. WILL KEEP THE MENTION OF FLURRIES IN THE EAST IN THE EVENING. THU-SAT...THE RIDGING BUILDING IN WILL FLATTEN A BIT ON THU LEAVING THE FA IN WEST-NORTHWEST FLOW FOR THU/FRI. SHOULD HAVE SOUTHWEST SFC WINDS ON THU AND FRI AS MILD AIR MOVES BACK IN WHICH ARE GOOD FOR WARMING. ALSO SHOULD HAVE QUITE A BIT OF SUN WHICH IS A RARE COMBINATION FOR EARLY JAN. BY SAT ANOTHER WEAK 500MB WAVE MOVES BACK IN. WILL KEEP A DRY FORECAST FOR THIS WEAK EVENT WHICH MAY JUST SPREAD A LITTLE MORE CLOUD COVER ACROSS THE AREA. TEMPS CONTINUE TO LOOK MILD SAT AS WELL. LONG TERM (SAT NIGHT-TUE)... SHORT WAVE RIDGE TO BUILD OVER FA OVER SECOND HALF OF WEEKEND KEEPING TEMPERATURES FAIRLY MILD WITH LITTLE IN THE WAY OF ANY PCPN. MODELS DIFFER SOMEWHAT ON STRENGTH/TIMING OF SHORT WAVE EARLY NEXT WEEK HOWEVER ON THE SURFACE BOTH GFS/ECMWF KEEP LOW TRACK NORTH/EAST OF FA KEEPING REGION IN WARM SECTOR AND NO REAL PUSH OF COLD AIR IN THE WAKE OF THE SYSTEM. THIS SHOULD KEEP TEMPERATURES AT OR ABOVE AVERAGE THROUGH REMAINDER OF LONG TERM AND MINIMAL SNOW CHANCES. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ TG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
640 PM EST WED JAN 2 2013 .SYNOPSIS... HIGH PRESSURE CROSSES TONIGHT. CLIPPER LIKE SYSTEM PASSES THURSDAY NIGHT. TWO UPPER SHORT WAVES PASS THIS WEEKEND...FOLLOWED BY HIGH PRESSURE. && .NEAR TERM /THROUGH THURSDAY/... 630PM UPDATE... OVERNIGHT LOWS CONTINUE TO BE THE TRICKY PART OF THE FORECAST. SHOULD LOSE THE HIGH LEVEL CIRRUS TOWARDS THE END OF THE OVERNIGHT FOR LOCATIONS UP TO THE MOUNTAINS...SO WILL DROP IN GOOD RADIATION CONDITIONS. SREF PICKING UP ON STRATUS CLIPPING OUR EXTREME NORTHWEST COUNTIES IN SOUTHEAST OHIO OVERNIGHT...AND LOW LEVEL CLOUDS ON THE FAR EASTERN SLOPES IN POCAHONTAS COUNTY. PREVIOUS DISCUSSION... HEATING HAS ALLOWED STRATOCU TO FORM THIS AFTN...MOST PREVALENT ACROSS SE OH AND N WV. LINGERING LLVL MOISTURE UNDER INVERSION PROVIDING FOR A DREARY DAY ACROSS SW VA WITH LOW CIGS AND SOME FOG. WILL ALLOW STRATOCU TO DISSIPATE WITH LOSS OF SUN AS CIRRUS BLOW-OFF RIDING JET FROM SW INVADES TONIGHT. SOME CONCERN WITH LOW STRATUS HANGING TOUGH ACROSS SE OH AND N WV PER RUC SOUNDINGS BUT OTHER MDLS NOT REALLY SHOWING THIS. FOR TEMPS WILL HEDGE THAT CIRRUS IS OPAQUE ENOUGH TO NOT HINDER FALL TOO MUCH. LOOKING AT TEENS AND LWR 20S FOR MOST PART FOR OVERNIGHT LOWS. DRY CONDITIONS PREVAIL TOMORROW WITH A MAINLY SUNNY SKY...SAVE FOR PERHAPS PORTIONS OF SW VA TOWARD DICKENSON CO WHERE LOW CLOUDS MAY LINGER THROUGH THE MORNING. HIGHS REBOUND SOME WITH EVERYONE OUTSIDE OF HIGHER ELEVATIONS IN THE 30S. SOME CLDS MAY SNEAK INTO SE OH TOWARD EVENING FROM AN APPROACHING CLIPPER TYPE FRONT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... VERY PROGRESSIVE AND DRY PATTERN THIS PERIOD. MODELS HAVE A MOISTURE STARVED SHORT WAVE AND COLD FRONT IN THE NORTHERN STREAM DROPPING RAPIDLY SOUTHEAST ACROSS THE OHIO VALLEY THURSDAY NIGHT AND EARLY FRIDAY. A THERMAL TROUGH IN NORTHWEST FLOW BEHIND THE FRONT PROMPTS SMALL POPS FOR SNOW SHOWERS MAINLY THURSDAY NIGHT...AND MOSTLY IN THE MOUNTAINS...WITH LITTLE IF ANY ACCUMULATIONS. THEN...A QUIET PERIOD WITH MODERATING TEMPERATURES LATER FRIDAY AND SATURDAY AS A LOW AMPLITUDE UPPER RIDGE BUILDS OVER THE AREA. IT WILL BE JUST AFTER THIS PERIOD BEFORE THE NEXT SYSTEM CAN AFFECT US. LOOK FOR BELOW NORMAL TEMPS THURSDAY NIGHT AND FRIDAY BEHIND THE FRONT...MODERATING CLOSE TO NORMAL ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... STRONG SHORT WAVE WILL MOVE ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY. BUFKIT SOUNDING CONTINUE TO INDICATE SATURATED SFC TO BARELY BELOW MINUS 10C LEVEL...SUGGESTING GOOD CHANCES FOR LIGHT SNOW FOLLOWED BY FREEZING DRIZZLE AS THE SYSTEM PULLS NORTHEAST. NORTHWEST BACKWARDS TRAJECTORIES FROM SUNDAY RETURNS FROM IL AND WI...BRINGING MUCH COLD AIR...CAPABLE TO SQUEEZE LOW LEVEL MOISTURE INTO THE MOUNTAINS...TO PRODUCE LIGHT UPSLOPE SNOW OR FREEZING DRIZZLE PER SHALLOWER MOISTURE IN THE COLUMN WITH NO LAKE CONNECTION BELOW MINUS 10C. THEREFORE...KEPT POPS TO CHANCE FOR NOW ACROSS THE NORTHERN HALF OF OUR CWA THROUGH SATURDAY NIGHT DIMINISHING BY EARLY MONDAY. TWEAKED HPC GUIDANCE FOR TEMPS THROUGH THE PERIOD...ACCOUNTING FOR CLOUD COVER AND GFS H850 COLDER TEMPERATURES. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... GENERAL CLEARING TONIGHT OF THE HIGH CLOUDS FROM NORTHWEST TO SOUTHEAST...BUT VFR WILL PREVAIL. PERRY/MORGAN COUNTIES COULD SEE LOW LEVEL STRATUS FOR A FEW HOURS OVERNIGHT GIVING MVFR...BUT NOT FAR ENOUGH SOUTHEAST TO AFFECT PKB/HTS TERMINALS. EAST SLOPE OF THE NORTHEAST MOUNTAINS COULD ALSO SEE IFR OVERNIGHT...BUT NOT AFFECTING EKN. LIGHT SURFACE FLOW EXPECTED THROUGH THE FORECAST PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: STRATOCUMULUS/MVFR MAY REACH THE OHIO RIVER TONIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE THU UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06 CRW CONSISTENCY M M M M H H H H H H H H HTS CONSISTENCY M M M M H H H H H H H H BKW CONSISTENCY M M M M H H H H H H H H EKN CONSISTENCY M M M M H H H H H H H H PKB CONSISTENCY M M M M H H H H H H H H CKB CONSISTENCY M M M M H H H H H H H H AFTER 00Z FRIDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/JMV/30 NEAR TERM...30/26 SHORT TERM...JMV LONG TERM...ARJ AVIATION...26
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
608 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION ON TUESDAY...BRINGING AN END TO PRECIPITATION. HIGH PRESSURE WILL MOVE IN FOR WEDNESDAY...WITH A WEAK DISTURBANCE PASSING NORTH OF THE REGION THURSDAY AND THURSDAY NIGHT. ANOTHER AREA OF HIGH PRESSURE WILL MOVE OVER THE OHIO VALLEY ON FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE PRIMARY FORECAST CONCERN FOR TODAY WILL BE THE CHANCES OF DRIZZLE / FREEZING DRIZZLE THIS MORNING. MEASURABLE PRECIPITATION HAS ALL BUT ENDED FOR THE CWA...WITH THE MAJORITY OF THE FORCING AND DEEP MOISTURE PUSHING OFF TO THE EAST. HOWEVER...THE RADAR SCREENS HAVE FILLED IN WITH VERY LIGHT ECHOES (NOT JUST ON KILN...BUT ALSO ON KIND AND THE NEARBY TDWR SITES). RECENT HRRR RUNS HAVE ALSO DEPICTED PATCHY-LOOKING LIGHT ECHOES IN SIMULATED REFLECTIVITY. BASED ON SURFACE OBSERVATIONS...THESE ECHOES ARE AN INDICATION OF A MIXTURE OF FLURRIES AND DRIZZLE. THE GRIDS WILL THUS TRANSITION QUICKLY THIS MORNING FROM SNOW TO A FLURRY/DZ OR FLURRY/FZDZ MIX. ONE OF THE BIGGEST CHALLENGES IN FORECASTING DZ/FZDZ IS CERTAINLY PRESENTING ITSELF THIS MORNING...AS THERE IS QUITE A BIT OF UNCERTAINTY IN WHETHER OR NOT THERE IS ENOUGH MOISTURE AT TEMPS COLDER THAN -10C TO SUPPORT THE PRODUCTION OF ICE CRYSTALS. MODEL SOUNDINGS SHOW A RAPID DRYING ABOVE 700MB. RAP/NAM RH PLOTS AT -10C SHOW A RATHER EXTREME DRY PUNCH MOVING ENE OUT OF SOUTHERN INDIANA...WITH RH VALUES BELOW 5 PERCENT. DESPITE THIS...MANY OF THE OBSERVATIONS ARE KEEPING -SN AS THE PREVAILING WEATHER TYPE. BASED ON EYEWITNESS OBSERVATIONS AT NWS ILN...CURRENT PRECIPITATION IS IN THE FORM OF VERY SMALL CRYSTALS (STILL ICE...BUT NOT A TYPICAL SNOWFLAKE). GIVEN THE EXTREMELY WEAK ASCENT...TEMPERATURES VERY CLOSE TO FREEZING...AND APPARENT MIXING WITH SNOW...NO SIGNIFICANT IMPACTS FROM FZDZ ARE EXPECTED THIS MORNING. DESPITE THE DRYING ALOFT...THE LOW LEVEL MOISTURE IS FORECAST TO REMAIN THICK THROUGH THE DAY...WITH NOWHERE TO GO UNDER AN INVERSION. ANY EROSION TO THE CLOUD BASE WILL COME LATE IN THE DAY OR TONIGHT. WITH COLD ADVECTION KICKING IN BEHIND THE SURFACE FRONT...AND LITTLE TO NOTHING IN THE WAY OF INSOLATION...TEMPERATURES WILL GO ALMOST NOWHERE TODAY FROM THE CURRENT VALUES. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... MID-LEVEL FLOW WILL REMAIN QUASI-ZONAL OVER THE OHIO VALLEY THROUGH THE END OF THE WEEK. AT THE SURFACE...HIGH PRESSURE WILL BEGIN NUDGING INTO THE OHIO VALLEY FROM THE SOUTHWEST TONIGHT. THIS NARROW RIDGE WILL BE SHUNTED A BIT TO THE SOUTHEAST AS A STACKED TROUGH (AND EVENTUAL SURFACE LOW) PASSES THROUGH THE GREAT LAKES ON THURSDAY. AFTER THE TROUGH AXIS CLEARS THE OHIO VALLEY THURSDAY NIGHT...A MUCH STRONGER AND LARGER HIGH WILL BEGIN TO ESTABLISH ITSELF ON FRIDAY. WITH THE CHILLY STARTING POINT AND GRADUALLY CLEARING SKIES...NOT TO MENTION THE SNOW PACK OVER THE REGION...SINGLE DIGIT TEMPS ARE BEING FORECAST FOR THE NORTHWESTERN CWA TONIGHT. ON WEDNESDAY...VERY LITTLE MIXING WILL OCCUR UNDER AN INVERSION...AND THE AXIS OF COLDEST 925MB TEMPS WILL ALSO BE PASSING THROUGH THE CWA. THROUGH BOTH OF THESE PERIODS...THE FORECAST IS GENERALLY LOWER THAN MODEL GUIDANCE. THE EXCEPTION TO THIS IS THE ECMWF FOR LOWS TONIGHT...WHICH IS GOING AS LOW AS 1 DEGREE IN DARKE COUNTY. THE COLD PATTERN WILL CONTINUE THROUGH THE WEEK...WITH ANOTHER SHOT OF COLD ADVECTION KICKING IN WITH THE SHORTWAVE ON THURSDAY. A SLIGHT CHANCE OF LIGHT SNOW HAS BEEN KEPT IN THE FORECAST FOR THURSDAY EVENING...GENERALLY FOR AREAS NORTH OF I-70. AN ARGUMENT COULD BE MADE THAT ONLY FLURRIES WILL BE EXPERIENCED THIS FAR SOUTH...SO THIS IS FAR FROM A CERTAINTY OR ANYTHING THAT WILL CAUSE MUCH OF AN IMPACT. LITTLE CHANGE IS EXPECTED FOR FRIDAY...WITH THE CWA AT THE NORTHEAST PERIPHERY OF THE SURFACE HIGH...AND STILL FAR AWAY FROM ANY LEGITIMATE WARM ADVECTION. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... THE 12Z ECMWF...GFS AND CMC ARE ALL IN DECENT AGREEMENT WITH SHORT WAVE ENERGY DROPPING DOWN ACROSS THE LOWER GREAT LAKES THURSDAY AFTERNOON INTO FRIDAY MORNING. THE BEST FORCING ASSOCIATED WITH THIS WILL REMAIN OFF TO OUR NORTH AND EAST...BUT THINK A FEW FLURRIES OR LIGHT SNOW SHOWERS WILL BE POSSIBLE AT LEAST ACROSS OUR NORTHEASTERN AREAS...PRIMARILY THURSDAY NIGHT. TEMPERATURES WILL REMAIN SEASONABLY COLD TO START THE LONG TERM PERIOD. WITH A LITTLE BIT OF REINFORCING COLD AIR BEHIND THE SHORT WAVE...WILL GO A COUPLE OF DEGREES COOLER FOR HIGHS FRIDAY COMPARED TO THURSDAY. WE WILL TRANSITION INTO MORE OF A WESTERLY FLOW PATTERN THROUGH THE WEEKEND...ALLOWING FOR A MODERATION IN TEMPERATURES SATURDAY THROUGH MONDAY. BY THE END OF THE PERIOD...EXPECT HIGHS TO BE NEAR OR EVEN A LITTLE ABOVE NORMAL FOR THIS TIME OF YEAR. THE GFS AND ECMWF ARE BOTH SHOWING A FAIRLY PROGRESSIVE SHORT WAVE WORKING ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY. WE MAY EVENTUALLY NEED SOME LOW POPS WITH THIS FEATURE...BUT MOISTURE APPEARS LIMITED SO WILL MAINTAIN A DRY FORECAST AT THIS POINT. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... A COLD FRONT WILL MOVE SLOWLY SOUTHEAST ACROSS THE TAF SITES THIS MORNING. FORECAST DILEMMA THIS MORNING HAS BEEN WHETHER TO INCLUDE DRIZZLE/FREEZING DRIZZLE IN THE TAFS. THE MODELS HAVE NOT HANDLED THE CURRENT PCPN DEVELOPMENT ACRS THE TAF SITES EALRY THIS MORNING. THEY HAD BEEN ADVERTISING THE POTENTIAL FOR DRIZZLE/FREEZING DRIZZLE BASED ON SURFACE TEMPERATURES...BUT SINCE STRONGER ECHOES ARE SHOWING UP ON THE RADAR...AND OBSERVATIONS ARE REPORTING SNOW...THE DRIZZLE/FREEZING DRIZZLE HAS BEEN HARD TO COME BY (SANS KCVG). CURRENT PCPN LOOKS TO MOVE OUT FAIRLY SOON SO WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO KEEP PCPN AT ANY GIVEN TAF SITE. OTHERWISE...FOR THIS AFTERNOON...DRIER AIR WILL BRING VSBYS BACK TO VFR...BUT LOW LEVEL MOISTURE WILL REMAIN WITH CIGS MVFR. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION TONIGHT AND ESTABLISH ITSELF OVER THE REGION ON TUESDAY. THIS WILL ALLOW LOW LEVEL MOISTURE TO EVENTUALLY SCOUR OUT/ERODE OVER THE AREA. OUTLOOK...MVFR CEILINGS POSSIBLE THURSDAY INTO FRIDAY MORNING. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM...JGL AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
416 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION ON TUESDAY...BRINGING AN END TO PRECIPITATION. HIGH PRESSURE WILL MOVE IN FOR WEDNESDAY...WITH A WEAK DISTURBANCE PASSING NORTH OF THE REGION THURSDAY AND THURSDAY NIGHT. ANOTHER AREA OF HIGH PRESSURE WILL MOVE OVER THE OHIO VALLEY ON FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE PRIMARY FORECAST CONCERN FOR TODAY WILL BE THE CHANCES OF DRIZZLE / FREEZING DRIZZLE THIS MORNING. MEASURABLE PRECIPITATION HAS ALL BUT ENDED FOR THE CWA...WITH THE MAJORITY OF THE FORCING AND DEEP MOISTURE PUSHING OFF TO THE EAST. HOWEVER...THE RADAR SCREENS HAVE FILLED IN WITH VERY LIGHT ECHOES (NOT JUST ON KILN...BUT ALSO ON KIND AND THE NEARBY TDWR SITES). RECENT HRRR RUNS HAVE ALSO DEPICTED PATCHY-LOOKING LIGHT ECHOES IN SIMULATED REFLECTIVITY. BASED ON SURFACE OBSERVATIONS...THESE ECHOES ARE AN INDICATION OF A MIXTURE OF FLURRIES AND DRIZZLE. THE GRIDS WILL THUS TRANSITION QUICKLY THIS MORNING FROM SNOW TO A FLURRY/DZ OR FLURRY/FZDZ MIX. ONE OF THE BIGGEST CHALLENGES IN FORECASTING DZ/FZDZ IS CERTAINLY PRESENTING ITSELF THIS MORNING...AS THERE IS QUITE A BIT OF UNCERTAINTY IN WHETHER OR NOT THERE IS ENOUGH MOISTURE AT TEMPS COLDER THAN -10C TO SUPPORT THE PRODUCTION OF ICE CRYSTALS. MODEL SOUNDINGS SHOW A RAPID DRYING ABOVE 700MB. RAP/NAM RH PLOTS AT -10C SHOW A RATHER EXTREME DRY PUNCH MOVING ENE OUT OF SOUTHERN INDIANA...WITH RH VALUES BELOW 5 PERCENT. DESPITE THIS...MANY OF THE OBSERVATIONS ARE KEEPING -SN AS THE PREVAILING WEATHER TYPE. BASED ON EYEWITNESS OBSERVATIONS AT NWS ILN...CURRENT PRECIPITATION IS IN THE FORM OF VERY SMALL CRYSTALS (STILL ICE...BUT NOT A TYPICAL SNOWFLAKE). GIVEN THE EXTREMELY WEAK ASCENT...TEMPERATURES VERY CLOSE TO FREEZING...AND APPARENT MIXING WITH SNOW...NO SIGNIFICANT IMPACTS FROM FZDZ ARE EXPECTED THIS MORNING. DESPITE THE DRYING ALOFT...THE LOW LEVEL MOISTURE IS FORECAST TO REMAIN THICK THROUGH THE DAY...WITH NOWHERE TO GO UNDER AN INVERSION. ANY EROSION TO THE CLOUD BASE WILL COME LATE IN THE DAY OR TONIGHT. WITH COLD ADVECTION KICKING IN BEHIND THE SURFACE FRONT...AND LITTLE TO NOTHING IN THE WAY OF INSOLATION...TEMPERATURES WILL GO ALMOST NOWHERE TODAY FROM THE CURRENT VALUES. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... MID-LEVEL FLOW WILL REMAIN QUASI-ZONAL OVER THE OHIO VALLEY THROUGH THE END OF THE WEEK. AT THE SURFACE...HIGH PRESSURE WILL BEGIN NUDGING INTO THE OHIO VALLEY FROM THE SOUTHWEST TONIGHT. THIS NARROW RIDGE WILL BE SHUNTED A BIT TO THE SOUTHEAST AS A STACKED TROUGH (AND EVENTUAL SURFACE LOW) PASSES THROUGH THE GREAT LAKES ON THURSDAY. AFTER THE TROUGH AXIS CLEARS THE OHIO VALLEY THURSDAY NIGHT...A MUCH STRONGER AND LARGER HIGH WILL BEGIN TO ESTABLISH ITSELF ON FRIDAY. WITH THE CHILLY STARTING POINT AND GRADUALLY CLEARING SKIES...NOT TO MENTION THE SNOW PACK OVER THE REGION...SINGLE DIGIT TEMPS ARE BEING FORECAST FOR THE NORTHWESTERN CWA TONIGHT. ON WEDNESDAY...VERY LITTLE MIXING WILL OCCUR UNDER AN INVERSION...AND THE AXIS OF COLDEST 925MB TEMPS WILL ALSO BE PASSING THROUGH THE CWA. THROUGH BOTH OF THESE PERIODS...THE FORECAST IS GENERALLY LOWER THAN MODEL GUIDANCE. THE EXCEPTION TO THIS IS THE ECMWF FOR LOWS TONIGHT...WHICH IS GOING AS LOW AS 1 DEGREE IN DARKE COUNTY. THE COLD PATTERN WILL CONTINUE THROUGH THE WEEK...WITH ANOTHER SHOT OF COLD ADVECTION KICKING IN WITH THE SHORTWAVE ON THURSDAY. A SLIGHT CHANCE OF LIGHT SNOW HAS BEEN KEPT IN THE FORECAST FOR THURSDAY EVENING...GENERALLY FOR AREAS NORTH OF I-70. AN ARGUMENT COULD BE MADE THAT ONLY FLURRIES WILL BE EXPERIENCED THIS FAR SOUTH...SO THIS IS FAR FROM A CERTAINTY OR ANYTHING THAT WILL CAUSE MUCH OF AN IMPACT. LITTLE CHANGE IS EXPECTED FOR FRIDAY...WITH THE CWA AT THE NORTHEAST PERIPHERY OF THE SURFACE HIGH...AND STILL FAR AWAY FROM ANY LEGITIMATE WARM ADVECTION. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... THE 12Z ECMWF...GFS AND CMC ARE ALL IN DECENT AGREEMENT WITH SHORT WAVE ENERGY DROPPING DOWN ACROSS THE LOWER GREAT LAKES THURSDAY AFTERNOON INTO FRIDAY MORNING. THE BEST FORCING ASSOCIATED WITH THIS WILL REMAIN OFF TO OUR NORTH AND EAST...BUT THINK A FEW FLURRIES OR LIGHT SNOW SHOWERS WILL BE POSSIBLE AT LEAST ACROSS OUR NORTHEASTERN AREAS...PRIMARILY THURSDAY NIGHT. TEMPERATURES WILL REMAIN SEASONABLY COLD TO START THE LONG TERM PERIOD. WITH A LITTLE BIT OF REINFORCING COLD AIR BEHIND THE SHORT WAVE...WILL GO A COUPLE OF DEGREES COOLER FOR HIGHS FRIDAY COMPARED TO THURSDAY. WE WILL TRANSITION INTO MORE OF A WESTERLY FLOW PATTERN THROUGH THE WEEKEND...ALLOWING FOR A MODERATION IN TEMPERATURES SATURDAY THROUGH MONDAY. BY THE END OF THE PERIOD...EXPECT HIGHS TO BE NEAR OR EVEN A LITTLE ABOVE NORMAL FOR THIS TIME OF YEAR. THE GFS AND ECMWF ARE BOTH SHOWING A FAIRLY PROGRESSIVE SHORT WAVE WORKING ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY. WE MAY EVENTUALLY NEED SOME LOW POPS WITH THIS FEATURE...BUT MOISTURE APPEARS LIMITED SO WILL MAINTAIN A DRY FORECAST AT THIS POINT. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... A COLD FRONT WILL MOVE SLOWLY SOUTHEAST ACROSS THE TAF SITES THIS MORNING. A QUICK INJECTION OF WAA ALONG AND AHEAD OF THE FRONT WILL BRING A BRIEF PERIOD OF SNOW EARLY THIS MORNING...ENDING BETWEEN 08Z AND 10Z. THE SNOW WILL BRING IFR CIGS AND VSBYS. THEREAFTER...VSBYS WILL LIFT TO MVFR AND CIGS WILL REMAIN IFR THROUGH MUCH OF THE MORNING. THERE IS A SMALL CHANCE THAT AS THE MAIN PCPN COMES TO AN END THAT THERE COULD BE A LITTLE FREEZING DRIZZLE. LATEST MODEL GUIDANCE...HOWEVER...DOES NOT SHOW MUCH LIFT IN THE LOW LEVELS...SO WILL NOT PLACE IN THE TAFS. FOR THIS AFTERNOON...DRIER AIR WILL BRING VSBYS BACK TO VFR...BUT LOW LEVEL MOISTURE WILL REMAIN WITH CIGS MVFR...BUT LIKELY REMAINING BELOW 2000 FEET. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION TONIGHT AND ESTABLISH ITSELF OVER THE REGION ON TUESDAY. THIS WILL ALLOW LOW LEVEL MOISTURE TO EVENTUALLY SCOUR OUT/ERODE OVER THE AREA. OUTLOOK...MVFR CEILINGS POSSIBLE THURSDAY INTO FRIDAY MORNING. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM...JGL AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
1111 PM CST MON DEC 31 2012 .AVIATION... 06Z TAFS... CEILINGS WILL BE VARIABLE TONIGHT ACROSS THE AREA. SOME VISIBILITIES WILL ALSO BE REDUCED BUT MAYBE NOT AS LOW AS EARLIER THIS EVENING. FZDZ WILL STILL BE POSSIBLE INTO TUESDAY MORNING... WHILE SOME SNOW FLURRIES MAY ALSO OCCUR IN A FEW LOCATIONS. CONDITIONS WILL IMPROVE TUESDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 1012 PM CST MON DEC 31 2012/ DISCUSSION... NO BIG CHANGES TO FORECAST THIS EVENING. COLDER AIR CONTINUES TO STEADILY FILTER INTO THE REGION WITH SURFACE FREEZING LINE NOW FROM ABOUT MIDFORD TO ALTUS TO CROWELL TX. SOME WEAK ECHOES PERSIST NEAR THE KANSAS BORDER WITH LIGHT SNOW OR DRIZZLE/FRSG DRIZZLE. THUS WILL LEAVE WINTER WEATHER ADVY IN PLACE AS IS. ALTHOUGH DEEPER MOISTURE HAS BEEN SHUNTED EWD WITH LEAD WAVE EARLIER TODAY...MODELS SHOW INCREASING LIFT AND MID LEVEL MOISTENING WITH IMPULSE LIFTING NEWD THROUGH W TX. HRRR THE MOST BULLISH WITH PRECIP POTENTIAL ALTHOUGH ANYTHING THAT MAKES IT TO THE GROUND WOULD BE VERY LIGHT. THUS WILL CONTINUE WITH MENTION OF DRIZZLE/FREEZING DRIZZLE OVERNIGHT. NO CHANGES BEYOND THE FIRST PD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 30 33 23 40 / 20 10 10 10 HOBART OK 24 32 20 40 / 10 0 0 0 WICHITA FALLS TX 31 39 23 40 / 10 10 10 10 GAGE OK 19 29 16 38 / 10 10 0 0 PONCA CITY OK 26 32 18 42 / 20 10 10 10 DURANT OK 36 43 27 42 / 10 10 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR OKZ006>008- 012-013. WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR OKZ004-005- 009-010. TX...NONE. && $$ 02/25/25
AREA FORECAST DISCUSSION
NWS NORMAN OK
1012 PM CST MON DEC 31 2012 .DISCUSSION... NO BIG CHANGES TO FORECAST THIS EVENING. COLDER AIR CONTINUES TO STEADILY FILTER INTO THE REGION WITH SURFACE FREEZING LINE NOW FROM ABOUT MIDFORD TO ALTUS TO CROWELL TX. SOME WEAK ECHOES PERSIST NEAR THE KANSAS BORDER WITH LIGHT SNOW OR DRIZZLE/FRSG DRIZZLE. THUS WILL LEAVE WINTER WEATHER ADVY IN PLACE AS IS. ALTHOUGH DEEPER MOISTURE HAS BEEN SHUNTED EWD WITH LEAD WAVE EARLIER TODAY...MODELS SHOW INCREASING LIFT AND MID LEVEL MOISTENING WITH IMPULSE LIFTING NEWD THROUGH W TX. HRRR THE MOST BULLISH WITH PRECIP POTENTIAL ALTHOUGH ANYTHING THAT MAKES IT TO THE GROUND WOULD BE VERY LIGHT. THUS WILL CONTINUE WITH MENTION OF DRIZZLE/FREEZING DRIZZLE OVERNIGHT. NO CHANGES BEYOND THE FIRST PD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 40 30 33 23 / 30 20 10 10 HOBART OK 42 24 32 20 / 20 10 0 0 WICHITA FALLS TX 48 31 39 23 / 20 10 10 10 GAGE OK 36 19 29 16 / 40 10 10 0 PONCA CITY OK 36 26 32 18 / 70 20 10 10 DURANT OK 42 36 43 27 / 50 10 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR OKZ006>008- 012-013. WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR OKZ004-005- 009-010. TX...NONE. && $$ 02/25
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1051 PM CST MON DEC 31 2012 .DISCUSSION.../ISSUED AT 1014 PM CST/ CURRENTLY SEEING AN AREA OF STRATUS MOVING EAST ACROSS THE CWA. HAVE MADE UPDATES TO SKY COVER AND TEMPERATURES THROUGH TONIGHT. LOOKS LIKE THIS STRATUS WILL CONTINUE TO MOVE EAST...COVERING THE ENTIRE CWA BY 09Z. WHERE STRATUS IS CURRENTLY...LOWS HAVE LIKELY ALREADY BEEN REACHED. PORTIONS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA HAVE A COUPLE MORE HOURS TO DROP...BEFORE STRATUS MOVES IN AND TEMPERATURES GO UP. RAP HAS A DECENT HANDLE ON STRATUS EVOLUTION. THUS HAVE FOLLOWED CLOSER TO IT AND INCREASED CLOUDS THROUGH TOMORROW. DONT SEE MUCH REASON WHY THE STRATUS WILL DISSIPATE...SEEMS MORE LIKELY IT WILL CONTINUE TO MOVE EAST AS THE BOUNDARY LAYER FLOW TURNS WESTERLY AND CLEAR FROM WEST TO EAST TOMORROW. CLEARING AROUND 12Z IN OUR WEST...AFTER 18Z IN THE INTERSTATE 29 CORRIDOR...AND NOT EXITING OUR EAST UNTIL AFTER 0Z. WOULD NOT BE SURPRISED IF HIGHS TOMORROW END UP A FEW DEGREES BELOW FORECAST GIVEN THE CLOUDS....BUT WILL LEAVE THEM AS IS FOR NOW...AS WITH THE WARMER START WE STILL MIGHT BE ABLE TO GET CLOSE TO THE FORECAST HIGHS. /CHENARD && .AVIATION.../FOR THE 06Z TAF ISSUANCE/ SKY CONDITIONS HAVE BECOME LESS MUDDLED SINCE THE PREVIOUS TAF FORECAST. AT THIS TIME...A LOT OF MVFR STRATUS IS MOVING EASTWARD ACROSS OUR FORECAST AREA...AND WILL EVENTUALLY MOVE THROUGH ALL OF SOUTHWEST MINNESOTA AND MUCH OF NORTHWEST IOWA BY LATE TONIGHT. SO THE MAIN QUESTION NOW IS WHEN WILL THE MVFR CONDITIONS ABATE ON TUESDAY. LOW LEVEL WINDS FROM THE SURFACE TO THE BOUNDARY LAYER WILL BECOME SOUTHERLY AS THE REST OF THE NIGHT PROGRESSES. HOWEVER THERE CERTAINLY IS A SUBTLE TROUGH AXIS CURRENTLY MOVING THROUGH WESTERN AND CENTRAL SD. THEREFORE BOUNDARY LAYER WINDS WILL BECOME WESTERLY AT CHAMBERLAIN SD BY ABOUT 11Z...AND THEN MOVE EASTWARD FROM THERE ALBEIT WEAKENING AND THUS KEEPING THE LOW LEVEL WIND DIRECTION FROM THE SOUTHWEST FROM THE JAMES VALLEY AND POINTS EASTWARD. WITH LOW LEVEL WINDS FROM THE SOUTHWEST INSTEAD OF DUE WEST...THIS MAY SLOW THE PROGRESSION OF THE EASTWARD MOVING CLEARING LINE ON TUESDAY. HOWEVER THERE SHOULD BE ENOUGH PUSH...EVEN WITH LIGHT WINDS...TO ADVANCE THE CLEARING LINE TO THE I 29 CORRIDOR BY MIDDAY TUESDAY... AND INTO SOUTHWEST MN AND NORTHWEST IA THROUGH TUESDAY AFTERNOON. SO CURRENT THINKING IS FOR THE KHON TAF SITE TO GO VFR IN THE MID TO LATE MORNING...AND THE KFSD AND KSUX TAF SITES TO GO VFR BY MIDDAY. && .PREVIOUS DISCUSSION.../ISSUED AT 255 PM CST/ FOCUS TONIGHT WILL BE ON STRATUS IN THE WESTERN CWA AND WEATHER OR NOT THAT WILL TRANSLATE EAST. THE REASON THIS IS SO IMPORTANT IS IT WILL LIKELY HAVE A 10 TO 15 DEGREE AFFECT ON TEMPERATURES...WITH AREAS STAYING OUT OF THE STRATUS FALLING TO AROUND 10 BELOW WHILE THOSE AREAS UNDER THE STRATUS SHOULD DROP TO ABOUT 5 ABOVE OR SO. DRY ARCTIC AIR INTRUDING FROM THE NORTHEAST SHOULD HOLD THE STRATUS AT BAY THROUGH MID EVENING BUT HAVE THE FEELING THAT IT WILL WORK EASTWARD ACROSS INTERSTATE 29 INTO NORTHWEST IOWA. THE AREA WITH THE BEST CHANCE TO REMAIN IN THE CLEAR WILL BE ALONG AND EAST OF THE BUFFALO RIDGE...SO WILL KEEP LOWS AROUND 10 BELOW IN THESE LOCATIONS. WILL THEN TRANSITION TO LOWS OF ABOUT 5 TO 10 ABOVE ZERO IN CENTRAL SOUTH DAKOTA WHERE CLOUDS ARE IN PLACE AND A LIGHT SOUTH TO SOUTHWEST WIND SHOULD DEVELOP LATE TONIGHT. THE INTERSTATE 29 CORRIDOR THE TOUGHEST CALL BECAUSE IF STRATUS COMES IN AROUND SUNSET LOWS WILL LIKELY BE 10 DEGREES HIGHER THAN FORECAST. ALSO NEED TO WATCH THE SNOW TO THE SOUTH AS A FEW FLURRIES COULD WORK NORTH TOWARDS SIOUX CITY AND STORM LAKE THIS EVENING BUT FOR NOW BELIEVE THAT THE DRY ARCTIC AIR IN THE LOWER LEVELS WILL KEEP THE FLAKES TO THE SOUTH. EXPECT THE STRATUS TO LIFT AND PARTLY TO MOSTLY SUNNY SKIES TO DEVELOP ON TUESDAY AS A WEST TO SOUTHWEST WIND BRINGS IN MILDER READINGS. RAISED HIGHS A BIT AND KEPT TEMPERATURES WARMER THAN GUIDANCE BY LATE IN THE DAY AS CONDITIONS SHOULD REMAIN MIXED INTO THE EVENING. EXPECT HIGHS NEAR 20 IN THE EAST AND NEAR 30 IN THE WEST. /08 A WEAK AND DISORGANIZED WAVE WILL MOVE ACROSS THE AREA ON WEDNESDAY WHICH WILL BE FOLLOWED BY ANOTHER BRIEF SHOT OF COLD AIR. THE UPPER WAVE WAVE WILL BEGIN TO APPROACH ON TUESDAY NIGHT WITH AN INCREASE IN BOTH CLOUDS AND WESTERLY WINDS. WITH WEST WINDS INCREASING THROUGH THE NIGHT...EXPECT THAT MOST PLACES WILL REACH LOWS IN THE EVENING WITH RISING TEMPERATURES OVERNIGHT. SOME LIGHT SNOW MAY MOVE IN LATE IN THE NIGHT WEST OF THE JAMES RIVER. THE UPPER WAVE MOVES ACROSS ON WEDNESDAY. THERE IS LITTLE TO NO FRONTOGENESIS OR EVEN WARM ADVECTION WITH THIS SYSTEM...IT RELIES ENTIRELY ON THE UPPER LEVEL WAVE. ALL MODELS SHOW THAT THE DYNAMICS REALLY BEGIN TO WEAKEN AND SPLIT WITH SOME ENERGY DIVING INTO NEBRASKA AND THE REST STAYING CLOSER TO I94. AS A RESULT...WHILE WE EXPECT TO SEE FLURRIES WITH THIS SYSTEM BETWEEN WEDNESDAY AND WEDNESDAY NIGHT...THE PROBABILITY OF MEASURABLE SNOW REMAINS LOW...50 PERCENT OR LESS. AND FOR LOCATIONS THAT SEE MEASURABLE SNOWFALL...IT SHOULD BE LESS THAN AN INCH AND LIKELY LESS THAN A HALF INCH. THE BEST CHANCE FOR MEASURABLE SNOW WILL BE WEDNESDAY AFTERNOON...ALTHOUGH FLURRIES ARE LIKELY TO CONTINUE INTO WEDNESDAY NIGHT. HIGHS WEDNESDAY WILL BE IN THE 20S. WITH THE COLD AIR MOVING IN ON NW WINDS...LOW WEDNESDAY NIGHT WILL BE IN THE SINGLE DIGITS ABOVE ZERO. THURSDAY LOOKS TO BE BELOW NORMAL AS COLD AIR MOVES IN EAST OF THE JAMES RIVER. THIS COLD AIR WILL NOT LAST LONG AND WARMING WILL ALREADY MOVE INTO AREAS WEST OF THE JAMES BY THURSDAY AFTERNOON. EVEN WITH WEAK EARLY JANUARY SUN...HIGHS WILL STRUGGLE TO GET ABOVE 10 DEGREES EAST OF THE JAMES...BUT SHOULD APPROACH 20 IN SOUTH CENTRAL SD. THURSDAY NIGHT COULD BE A REPEAT OF TUESDAY NIGHT WITH A QUICK DROP FOR 5 TO 10 DEGREES AND THEN RISING TEMPERATURES AS WESTERLY WINDS PICK UP. FOR FRIDAY THROUGH MONDAY...IT IS LOOKING LIKE A FAIRLY SIGNIFICANT WARMING TREND WITH NO PRECIPITATION. THERE IS VERY LITTLE DIFFERENCE BETWEEN THE ECMWF...GFS AND THE GFS ENSEMBLE. ALL AGREE THAT A LONG WAVE RIDGE WILL SET UP OVER THE CWA. WHILE A WAVE WILL DROP SOUTHEAST IN THE NW FLOW ON FRIDAY NIGHT AND SATURDAY...IT WILL BRING ONLY A BRIEF PERIOD OF COOLER AIR FOLLOWED BY VERY MILD AIR BY SUNDAY. THE ONLY QUESTION REALLY IS HOW MUCH SNOW COVER INHIBITS MIXING AND WARMING DURING THE DAY. THE SNOWPACK...WHILE FROM 4 TO 10 INCHES...IS FAIRLY DRY AND WITH A LONG ENOUGH WARM PERIOD COULD BE SIGNIFICANTLY REDUCED BY MONDAY. FOR NOW STAYED CONSERVATIVE WITH HIGHS FRIDAY AND SATURDAY IN THE 20S AND 30S. HAVE THE WARMEST DAY ON SUNDAY WITH HIGHS IN THE 30S AND 40S AND SIMILAR TEMPERATURES FORECAST FOR MONDAY. IF SNOWCOVER DISAPPEARS FASTER THAN EXPECTED...HIGHS BY SUNDAY AND MONDAY COULD BE ANOTHER 5 TO 10 DEGREES WARMER./SCHUMACHER && .FSD WATCHES/WARNINGS/ADVISORIES... IA...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST TUESDAY FOR IAZ002-003-014-022. MN...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST TUESDAY FOR MNZ071-072-080-081-089-090. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1014 PM CST MON DEC 31 2012 .DISCUSSION.../ISSUED AT 1014 PM CST/ CURRENTLY SEEING AN AREA OF STRATUS MOVING EAST ACROSS THE CWA. HAVE MADE UPDATES TO SKY COVER AND TEMPERATURES THROUGH TONIGHT. LOOKS LIKE THIS STRATUS WILL CONTINUE TO MOVE EAST...COVERING THE ENTIRE CWA BY 09Z. WHERE STRATUS IS CURRENTLY...LOWS HAVE LIKELY ALREADY BEEN REACHED. PORTIONS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA HAVE A COUPLE MORE HOURS TO DROP...BEFORE STRATUS MOVES IN AND TEMPERATURES GO UP. RAP HAS A DECENT HANDLE ON STRATUS EVOLUTION. THUS HAVE FOLLOWED CLOSER TO IT AND INCREASED CLOUDS THROUGH TOMORROW. DONT SEE MUCH REASON WHY THE STRATUS WILL DISSIPATE...SEEMS MORE LIKELY IT WILL CONTINUE TO MOVE EAST AS THE BOUNDARY LAYER FLOW TURNS WESTERLY AND CLEAR FROM WEST TO EAST TOMORROW. CLEARING AROUND 12Z IN OUR WEST...AFTER 18Z IN THE INTERSTATE 29 CORRIDOR...AND NOT EXITING OUR EAST UNTIL AFTER 0Z. WOULD NOT BE SURPRISED IF HIGHS TOMORROW END UP A FEW DEGREES BELOW FORECAST GIVEN THE CLOUDS....BUT WILL LEAVE THEM AS IS FOR NOW...AS WITH THE WARMER START WE STILL MIGHT BE ABLE TO GET CLOSE TO THE FORECAST HIGHS. /CHENARD .PREVIOUS DISCUSSION.../ISSUED AT 255 PM CST/ FOCUS TONIGHT WILL BE ON STRATUS IN THE WESTERN CWA AND WEATHER OR NOT THAT WILL TRANSLATE EAST. THE REASON THIS IS SO IMPORTANT IS IT WILL LIKELY HAVE A 10 TO 15 DEGREE AFFECT ON TEMPERATURES...WITH AREAS STAYING OUT OF THE STRATUS FALLING TO AROUND 10 BELOW WHILE THOSE AREAS UNDER THE STRATUS SHOULD DROP TO ABOUT 5 ABOVE OR SO. DRY ARCTIC AIR INTRUDING FROM THE NORTHEAST SHOULD HOLD THE STRATUS AT BAY THROUGH MID EVENING BUT HAVE THE FEELING THAT IT WILL WORK EASTWARD ACROSS INTERSTATE 29 INTO NORTHWEST IOWA. THE AREA WITH THE BEST CHANCE TO REMAIN IN THE CLEAR WILL BE ALONG AND EAST OF THE BUFFALO RIDGE...SO WILL KEEP LOWS AROUND 10 BELOW IN THESE LOCATIONS. WILL THEN TRANSITION TO LOWS OF ABOUT 5 TO 10 ABOVE ZERO IN CENTRAL SOUTH DAKOTA WHERE CLOUDS ARE IN PLACE AND A LIGHT SOUTH TO SOUTHWEST WIND SHOULD DEVELOP LATE TONIGHT. THE INTERSTATE 29 CORRIDOR THE TOUGHEST CALL BECAUSE IF STRATUS COMES IN AROUND SUNSET LOWS WILL LIKELY BE 10 DEGREES HIGHER THAN FORECAST. ALSO NEED TO WATCH THE SNOW TO THE SOUTH AS A FEW FLURRIES COULD WORK NORTH TOWARDS SIOUX CITY AND STORM LAKE THIS EVENING BUT FOR NOW BELIEVE THAT THE DRY ARCTIC AIR IN THE LOWER LEVELS WILL KEEP THE FLAKES TO THE SOUTH. EXPECT THE STRATUS TO LIFT AND PARTLY TO MOSTLY SUNNY SKIES TO DEVELOP ON TUESDAY AS A WEST TO SOUTHWEST WIND BRINGS IN MILDER READINGS. RAISED HIGHS A BIT AND KEPT TEMPERATURES WARMER THAN GUIDANCE BY LATE IN THE DAY AS CONDITIONS SHOULD REMAIN MIXED INTO THE EVENING. EXPECT HIGHS NEAR 20 IN THE EAST AND NEAR 30 IN THE WEST. /08 A WEAK AND DISORGANIZED WAVE WILL MOVE ACROSS THE AREA ON WEDNESDAY WHICH WILL BE FOLLOWED BY ANOTHER BRIEF SHOT OF COLD AIR. THE UPPER WAVE WAVE WILL BEGIN TO APPROACH ON TUESDAY NIGHT WITH AN INCREASE IN BOTH CLOUDS AND WESTERLY WINDS. WITH WEST WINDS INCREASING THROUGH THE NIGHT...EXPECT THAT MOST PLACES WILL REACH LOWS IN THE EVENING WITH RISING TEMPERATURES OVERNIGHT. SOME LIGHT SNOW MAY MOVE IN LATE IN THE NIGHT WEST OF THE JAMES RIVER. THE UPPER WAVE MOVES ACROSS ON WEDNESDAY. THERE IS LITTLE TO NO FRONTOGENESIS OR EVEN WARM ADVECTION WITH THIS SYSTEM...IT RELIES ENTIRELY ON THE UPPER LEVEL WAVE. ALL MODELS SHOW THAT THE DYNAMICS REALLY BEGIN TO WEAKEN AND SPLIT WITH SOME ENERGY DIVING INTO NEBRASKA AND THE REST STAYING CLOSER TO I94. AS A RESULT...WHILE WE EXPECT TO SEE FLURRIES WITH THIS SYSTEM BETWEEN WEDNESDAY AND WEDNESDAY NIGHT...THE PROBABILITY OF MEASURABLE SNOW REMAINS LOW...50 PERCENT OR LESS. AND FOR LOCATIONS THAT SEE MEASURABLE SNOWFALL...IT SHOULD BE LESS THAN AN INCH AND LIKELY LESS THAN A HALF INCH. THE BEST CHANCE FOR MEASURABLE SNOW WILL BE WEDNESDAY AFTERNOON...ALTHOUGH FLURRIES ARE LIKELY TO CONTINUE INTO WEDNESDAY NIGHT. HIGHS WEDNESDAY WILL BE IN THE 20S. WITH THE COLD AIR MOVING IN ON NW WINDS...LOW WEDNESDAY NIGHT WILL BE IN THE SINGLE DIGITS ABOVE ZERO. THURSDAY LOOKS TO BE BELOW NORMAL AS COLD AIR MOVES IN EAST OF THE JAMES RIVER. THIS COLD AIR WILL NOT LAST LONG AND WARMING WILL ALREADY MOVE INTO AREAS WEST OF THE JAMES BY THURSDAY AFTERNOON. EVEN WITH WEAK EARLY JANUARY SUN...HIGHS WILL STRUGGLE TO GET ABOVE 10 DEGREES EAST OF THE JAMES...BUT SHOULD APPROACH 20 IN SOUTH CENTRAL SD. THURSDAY NIGHT COULD BE A REPEAT OF TUESDAY NIGHT WITH A QUICK DROP FOR 5 TO 10 DEGREES AND THEN RISING TEMPERATURES AS WESTERLY WINDS PICK UP. FOR FRIDAY THROUGH MONDAY...IT IS LOOKING LIKE A FAIRLY SIGNIFICANT WARMING TREND WITH NO PRECIPITATION. THERE IS VERY LITTLE DIFFERENCE BETWEEN THE ECMWF...GFS AND THE GFS ENSEMBLE. ALL AGREE THAT A LONG WAVE RIDGE WILL SET UP OVER THE CWA. WHILE A WAVE WILL DROP SOUTHEAST IN THE NW FLOW ON FRIDAY NIGHT AND SATURDAY...IT WILL BRING ONLY A BRIEF PERIOD OF COOLER AIR FOLLOWED BY VERY MILD AIR BY SUNDAY. THE ONLY QUESTION REALLY IS HOW MUCH SNOW COVER INHIBITS MIXING AND WARMING DURING THE DAY. THE SNOWPACK...WHILE FROM 4 TO 10 INCHES...IS FAIRLY DRY AND WITH A LONG ENOUGH WARM PERIOD COULD BE SIGNIFICANTLY REDUCED BY MONDAY. FOR NOW STAYED CONSERVATIVE WITH HIGHS FRIDAY AND SATURDAY IN THE 20S AND 30S. HAVE THE WARMEST DAY ON SUNDAY WITH HIGHS IN THE 30S AND 40S AND SIMILAR TEMPERATURES FORECAST FOR MONDAY. IF SNOWCOVER DISAPPEARS FASTER THAN EXPECTED...HIGHS BY SUNDAY AND MONDAY COULD BE ANOTHER 5 TO 10 DEGREES WARMER./SCHUMACHER && .AVIATION.../FOR THE 00Z TAF ISSUANCE/ CONDITIONS SHOULD REMAIN VFR FOR MANY AREAS EAST OF THE I 29 CORRIDOR FOR TONIGHT AND EARLY TUESDAY. HOWEVER ALONG AND WEST OF I 29...CONDITIONS BECOME MORE PROBLEMATIC. THERE ARE GENERALLY FOUR LAYERS OF CLOUDS. ONE IS AROUND 8000 FEET AGL EXTENDING THROUGH MUCH OF EAST CENTRAL AND SOUTHEAST SD. ANOTHER IS NEAR 3000 FEET AGL IN EAST CENTRAL SD...ARCHING SOUTHWARD TO JUST NORTH OF KFSD. A THIRD DECK IS CURRENTLY NEAR 2200 FEET AGL IN THE MIDDLE PORTIONS OF THE JAMES RIVER VALLEY...WHILE THE LAST DECK OF AROUND 1500 FEET IS EVIDENT IN SOUTH CENTRAL SD. FURTHERMORE...THE IR VIS/FOG CURVE SHOW THAT KHON AND KMHE ARE ACTUALLY ON THE VERY EDGE OF THE 2200 FOOT DECK WITH MID LEVEL CLOUDS IN BETWEEN THE TWO SITES. WINDS OFF THE SURFACE ARE THE KEY...AND MAINLY FOLLOWED THE RUC13 FOR GUIDANCE. THEREFORE THE KFSD AND KHON TAF SITES SHOULD SEE MVFR CONDITIONS FOR MUCH OF THE NIGHT AND TUESDAY MORNING...BUT AT TIMES WILL PROBABLY BE VFR NEAR 8000 FEET DEPENDING ON EXACT MOVEMENT OF THE MVFR DECK. KSUX MAY BE IN A SWEET SPOT...TOO FAR SOUTH TO BE IMPACTED BY THE SOUTH DAKOTA STRATUS...AND TOO FAR NORTH TO BE IMPACTED BY THE UPPER LOW TO THE SOUTH. THAT SAID...WINDS OFF THE SURFACE IN THE BOUNDARY LAYER SWITCH TO THE SOUTHWEST TUESDAY MORNING...SO AM CONCERNED THAT SOME STRATUS IN THE CENTRAL PLAINS WILL MOVE INTO KSUX AS TUESDAY MORNING PROGRESSES. FURTHERMORE...WITH THE AFOREMENTIONED WINDS OFF THE SURFACE ALSO OF A SOUTHWEST DIRECTION FOR THE KFSD AND KHON TAF SITES...AM NOT OVERLY CONFIDENT THAT THEY WILL SCATTER OUT IN THE AFTERNOON ON TUESDAY...AGAIN DUE TO THE ABUNDANT STRATUS IN THE CENTRAL PLAINS. /MJF && .FSD WATCHES/WARNINGS/ADVISORIES... IA...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST TUESDAY FOR IAZ002-003-014-022. MN...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 9 AM CST TUESDAY FOR MNZ071-072-080-081-089-090. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1229 PM CST TUE JAN 1 2013 .DISCUSSION... PLEASE SEE 18Z AVN DISCUSSION... && .AVIATION... CIGS IN THE HOUSTON METRO AREA HAVE IMPROVED TO VFR THIS AFTERNOON...HOWEVER THIS IMPROVEMENT IS NOT LIKELY TO EXTEND FURTHER INLAND TO UTS OR CXO. MVFR CONDITIONS ARE LIKELY TO PERSIST AT THE COASTAL COASTAL TERMINALS AS THEY REMAIN ON THE BACK EDGE OF A LARGE RAIN SHIELD EXTENDING OFF SHORE. ALL TERMINALS WILL LIKELY BE MVFR AFTER 01Z THIS EVENING. VFR CONDITIONS ARE POSSIBLE IN THE HOUSTON TERMINALS BY MID-MORNING WEDNESDAY. MVFR CONDITIONS SHOULD PERSIST AT OTHER TERMINALS. && .PREV DISCUSSION... /ISSUED 1012 AM CST TUE JAN 1 2013/ DISCUSSION... HEAVIER PRECIP HAS SHIFTED OFFSHORE AND IS ALONG THE COLD FRONT OVER THE COASTAL WATERS OUT BEYOND 20NM. THE FRONT SHOULD CONTINUE TO MOVE SOUTHEAST THOUGH SLOWLY. PATCHY LIGHT RAIN WILL CONTINUE THIS MORNING MAINLY OVER THE SOUTHERN HALF OF THE AREA INTO THE EARLY AFTERNOON. AS LIFT WITH APPROACHING SHORTWAVE OVER THE HILL COUNTRY NEARS EXPECT THE PRECIP TO SHIFT EAST AND LIGHTEN. OVERCAST SKIES WILL PREVAIL THROUGH THE AFTERNOON HOURS BUT MAY BECOME BROKEN THIS EVENING IN THE NORTHWESTERN AREAS WITH MAINLY HIGH CLOUDS. THE LIGHT PRECIP AND COLD AIR ADVECTION SHOULD KEEP TEMPERATURES IN THE MID 40S TO MID 50S WITH NEAR STEADY TEMPERATURES. WILL LIKELY DO AN UPDATE AROUND 1130 OR NOON TO CLEAR OUT PRECIP IN THE WEST AND NORTHWEST. AS OF 1005 AM THIS MORNING GALVESTON HAS HAD A RECORD SETTING 3.99" OF RAIN AND IS STILL FALLING THOUGH LIGHTER NOW. 45 PREV DISCUSSION... /ISSUED 529 AM CST TUE JAN 1 2013/ UPDATE... SEE 12Z AVIATION DISCUSSION. AVIATION... MODELS DID NOT INITIALIZE PARTICULARLY WELL THIS MORNING SO CONFIDENCE IS RATHER LOW. WENT WITH A GFS/RAP BLEND. AREA OF HEAVY RAIN/TSRA ALONG THE COAST WILL MOVE OFFSHORE IN THE NEXT HOUR OR SO. THIS WILL LEAVE JUST SOME PATCHY LIGHT RAIN FOR THE NEXT COUPLE OF HOURS OVER THE REST OF SE TX. THE RAP MASS FIELDS KEEPS MOST OF THE RAIN AWAY FROM AREA TAF SITES. A PRE-FRONTAL TROUGH IS APPROACHING THE COAST WITH THE ACTUAL FRONT STILL LAGGING A FEW HOURS BEHIND. AM EXPECTING WINDS TO SHIFT TO THE NORTH AND INCREASE THIS MORNING. CIGS ARE THE OTHER ISSUE AND FCST SOUNDINGS ARE PESSIMISTIC WITH CIGS TODAY. WILL MAINTAIN LIFR CIGS THROUGH 18Z AND THEN SHOW IMPROVEMENT TO VFR CONDS BY MID AFTN. 43 PREV DISCUSSION... /ISSUED 451 AM CST TUE JAN 1 2013/ DISCUSSION... IT IS GOOD TO SEE RAIN ON THE RADAR ACROSS SE TX AS WE HEAD INTO THE NEW YEAR. IT LOOKS LIKE COLLEGE STATION MAY BE THE ONLY CLIMATE SITE WITH ABOVE NORMAL PRECIPITATION FOR THE YEAR WITH HOUSTON IAH...HOUSTON HOU AND GALVESTON ALL SHOWING RAINFALL DEFICITS TO END THE YEAR. THE OTHER CLIMATE NOTE IS THAT 2012 SHOULD GO DOWN AS THE WARMEST YEAR ON RECORD FOR HOUSTON. SEE MORE DETAILS IN THE CLIMATE SECTION. CURRENTLY HAVE A LINE OF SHOWERS AND THUNDERSTORMS FROM SW LA INTO SE TX AND ALONG THE UPPER TX COAST. MOST OF THE HEAVY RAINFALL SHOULD BE CONCENTRATED RIGHT ALONG THE IMMEDIATE COAST INCLUDING GALVESTON IS AND BOLIVAR. THIS ACTIVITY SHOULD SLOWLY MOVE EAST. A COLD FRONT IS SLOWLY PUSHING INTO THE AREA WITH A PRE-FRONTAL TROUGH STALLED ACROSS THE HOUSTON AREA. BROAD UPPER LEVEL TROUGH REMAINS OVER THE DESERT SW WITH SW JET FLOW FROM BIG BEND OF TX TO THE OHIO RIVER VALLEY. RIGHT REAR QUAD OF UPPER JET OR RIGHT ENTRANCE REGION SHOULD MOVE OVER TX TODAY AND WED BASED ON SHORT RANGE MODELS. OVERALL THE SET UP IS FAVORABLE FOR RAIN OR ELEVATED SHOWERS. DRIER AIR SHOULD MOVE INTO THE AREA LATER TODAY AND TONIGHT WHICH SHOULD KEEP PRECIP CHANCES CONFINED TO THE SOUTHERN HALF OF THE FORECAST AREA AND THE COASTAL WATERS. BASED ON 00Z MODEL SUITE THINK MAJORITY OF RAINFALL WILL REMAIN OFF THE COAST SO TAILORED POPS CLOSER TO THAT THINKING. THIS MEANS KEEPING 20/30 POPS IN THE FORECAST ALONG THE COAST THROUGH MID WEEK. WITH JET FLOW REMAINING SW THROUGH THE END OF THE WEEK...LIKELY HAVE MOSTLY CLOUDY CONDITIONS WHICH WITH COOLER AIRMASS WILL KEEP TEMPS A GOOD 5 DEGREES BELOW NORMAL. DECIDED TO SHIFT SOME 20 POPS INTO FRI NIGHT AND SAT MORNING. GFS SHOWS ANOTHER SHORTWAVE TROUGH PUSHING PAST THE AREA DURING THIS TIME WITH THE ECMWF SLOWER. SPLIT THE DIFFERENCES A BIT WITH THE TIMING OF THE DISTURBANCEBUT WHILE THERE MAY BE LARGE SCALE ASCENT FOR PRECIP...NOT SURE HOW MUCH MOISTURE WILL BE AVAILABLE. HIGH PRESSURE SHOULD BUILD INTO THE AREA AGAIN OVER THE WEEKEND. OVERALL EXPECT TEMPS TO CREEP UP TO NORMAL LEVELS FOR THE WEEKEND AND EARLY NEXT WEEK. SOUTHERLY RETURN FLOW AND INCREASED GULF MOISTURE IS NOT EXPECTED TO OCCUR UNTIL NEXT TUE. 39 MARINE... A PRE-FRONTAL TROUGH AND ASSOCIATED WIND SHIFT WAS APPROACHING THE COAST. A COLD FRONT LAGGED BEHIND...AND AT 2 AM THE FRONT EXTENDED FROM LUFKIN TO COLLEGE STATION. THE FRONT WILL CONTINUE TO SAG SOUTH AND THIS FEATURE SHOULD CROSS THE COAST BETWEEN 11-13Z. WINDS WILL QUICKLY SHIFT TO THE NORTH AND INCREASE TO GREATER THAN 20 KNOTS OVER THE GULF. AN SCA WILL REMAIN IN EFFECT FOR THE GULF WATERS THROUGH 21Z AND WILL LIKELY BE EXTENDED LONGER WITH THE AFTN UPDATE. AN SCEC WILL BE REQUIRED FOR THE BAYS TODAY. STRONG WINDS ARE EXPECTED FOR MOST OF THE WEEK AND SCA/SCEC FLAGS WILL BE NEEDED FOR MUCH OF THE WEEK AHEAD. TIDES ARE ABOVE NORMAL BUT OFFSHORE WINDS WILL LOWER TIDE LEVELS BY AFTERNOON AND TIDE LEVELS WILL REMAIN BELOW NORMAL ON THURSDAY. 43 CLIMATE... NO BIG SURPRISE WITH REGARD TO TEMPERATURES. DECEMBER 2012 WAS VERY WARM...AVERAGING 3 TO 5 DEGREES WARMER THAN THE 30 YEAR NORMALS. 2012 WILL ALSO HAVE THE DISTINCTION OF BEING THE WARMEST YEAR ON RECORD FOR THE CITY OF HOUSTON. THE UNOFFICIAL 2012 AVERAGE TEMPERATURE FOR THE CITY OF HOUSTON WAS 72.1 DEGREES. THE PREVIOUS WARMEST YEAR ON RECORD WAS 71.9 DEGREES IN 1962. FWIW...THE AVERAGE TEMPERATURE IN 2011 WAS 71.8 DEGREES WHICH WAS THE THIRD WARMEST YEAR ON RECORD. COLLEGE STATION HAD AN AVERAGE TEMPERATURE IN 2012 OF 71.6 DEGREES WHICH TIES LAST YEAR FOR THE WARMEST YEAR ON RECORD. THE CITY OF GALVESTON ALSO RECORDED IT`S WARMEST YEAR ON RECORD WITH AN AVERAGE TEMP OF 73.9 DEGREES. THE PREVIOUS WARMEST YEAR WAS 72.6 DEGREES BACK IN 2006. THE SIX WARMEST YEARS ON RECORD FOR GALVESTON HAVE OCCURRED SINCE 1994. HOBBY AIRPORT ALSO RECORDED IT`S WARMEST YEAR ON RECORD. THE AVERAGE ANNUAL TEMP WAS 72.6 DEGREES BESTING LAST YEARS RECORD VALUE OF 72.4 DEGREES. THE EIGHT WARMEST YEARS ON RECORD HAVE OCCURRED SINCE 1998. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 36 49 34 52 34 / 0 10 10 10 10 HOUSTON (IAH) 41 50 37 54 36 / 10 10 10 10 10 GALVESTON (GLS) 46 51 43 53 42 / 30 20 20 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...45 AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1201 PM CST TUE JAN 1 2013 .AVIATION... MVFR CEILINGS SHOULD CONTINUE THROUGH THE AFTERNOON AS LOW LEVEL MOISTURE LINGERS BELOW A STRONG INVERSION. THE LOW CLOUDS MAY SCATTER OUT BRIEFLY LATE THIS AFTERNOON DUE TO MIXING...BUT SHOULD FILL BACK IN SHORTLY AFTER SUNSET AND LINGER FOR MOST OF THE NIGHT. DRIER AIR ON THE BACK SIDE OF A DEPARTING SHORT WAVE SHOULD BRING DECREASING CLOUDS WEDNESDAY MORNING WITH VFR CONDITIONS EXPECTED AT ALL TAF SITES. A NORTH TO NORTHWEST WIND WILL PREVAIL THROUGH WEDNESDAY AFTERNOON AT SPEEDS BETWEEN 8 AND 14 KNOTS. && .UPDATE... AN UPPER LEVEL TROUGH CURRENTLY OVER THE TEXAS PANHANDLE IS INDUCING ENOUGH LIFT FOR SPRINKLES AND LIGHT RAIN TO DEVELOP ACROSS PARTS OF THE REGION. WITH DRIER AIR CONTINUING TO WORK IN FROM THE NORTH AND NORTHWEST...THE REMAINING PRECIP HAS NOW SHIFTED EAST OF A LINE FROM SHERMAN TO DALLAS TO TEMPLE. EXPECT THE SCATTERED LIGHT PRECIPITATION TO CONTINUE THIS MORNING WITH A SLIGHT CHANCE FOR LIGHT RAIN OVER THE EASTERN AND SOUTHEASTERN COUNTIES THIS AFTERNOON. EARLIER THIS MORNING...WE RECEIVED A FEW REPORTS OF VERY BRIEF AND LIGHT SLEET PELLETS FALLING WITH THE RAIN. THIS WILL ALSO BE POSSIBLE THROUGH THE MORNING HOURS. THE MAIN CHALLENGE FOR TODAY IS THE CLOUD COVER AND ITS EFFECTS ON TEMPERATURES. SHORT TERM MODELS SUCH AS THE RAP AND TEXAS TECH WRF SUGGEST PARTS /IF NOT ALL/ OF THE REGION WILL REMAIN SOCKED IN LOW CLOUDS FOR MUCH OF THE DAY...BUT THE MAIN DIAGNOSTIC MODELS WANT TO SCATTER MUCH OF THE REGION OUT THIS AFTERNOON...EXCEPT FOR MAYBE THE NORTHEASTERN COUNTIES. WITH THE UPPER LEVEL TROUGH SWINGING ACROSS OKLAHOMA TODAY AND NORTH TO NORTHWEST FLOW THROUGH THE MID LEVELS OF THE ATMOSPHERE...THIS IS OFTEN A SITUATION WHERE CLOUDS DO REMAIN AROUND FOR MUCH OF THE DAY AND TEMPERATURES STAY MUCH COOLER. HIGH CLOUDS STREAMING OVER THE AREA SHOULD ALSO WORK AGAINST EROSION OF THE LOWER LEVEL CLOUDS...BUT THE HIGH CLOUDS MAY SHIFT EAST THIS AFTERNOON AS THE UPPER LEVEL TROUGH CONTINUES MOVING EAST. EVEN THOUGH CONFIDENCE IN THIS SCENARIO IS NOT VERY HIGH DUE TO UNCERTAINTY ON IF AND WHERE THE CLOUDS WILL BREAK...HAVE DECIDED TO ADJUST THE SKIES TO MOSTLY CLOUDY AND CLOUDY FOR THE REMAINDER OF THE DAY. ALSO...ADJUSTED HIGH TEMPERATURES NORTH OF I-20 DOWN A FEW DEGREES BUT DID NOT ADJUST TEMPERATURES ELSEWHERE. OVERALL..THE FORECAST CALLS FOR A WARM-UP OF ABOUT 5 DEGREES FROM CURRENT TEMPERATURES...EXCEPT IN THE WEST WHERE THINNING CLOUDS THIS AFTERNOON MAY ALLOW TEMPS TO WARM ANOTHER 5-10 DEGREES. 82/JLD && .PREV DISCUSSION... /ISSUED 329 AM CST TUE JAN 1 2013/ POSITIVE-TILTED LONGWAVE TROUGH CONTINUES FROM ROCKIES INTO THE MISSISSIPPI VALLEY ALOFT. ONE SHORTWAVE WAS ROTATING NORTHEAST OUT OF NEW MEXICO WITH ANOTHER DROPPING SOUTH THROUGH WYOMING AND INTO COLORADO AND KANSAS. AT THE SURFACE...A WEAK FRONTAL WAVE WAS DRAPED NEAR THE I-10 CORRIDOR WITH A WEAK SURFACE LOW ACROSS SOUTH TEXAS. DRIER AIR WAS SLOWLY FILTERING ACROSS THE RED RIVER VALLEY INTO AREAS NORTH OF I-20. SHORT TERM FORECAST IS A BIT TRICKY THIS MORNING WITH COLD AIRMASS ONLY 1000-2000 FT DEEP ACROSS NORTH TEXAS...MORE SHALLOW THE FURTHER SOUTH OF I-20 YOU GO. PATCHY DENSE FOG AND DRIZZLE WAS OCCURRING WITHIN THE MORE SHALLOW COOL AIRMASS SOUTH OF THE I-20/30 CORRIDORS. ALSO...WEAK ISENTROPIC ASCENT WAS RESULTING IN SCATTERED AREAS OF VERY LIGHT RAIN ACROSS OUR CENTRAL TEXAS COUNTIES. WE EXPECT THE PATCHY DENSE FOG/RAIN/ DRIZZLE TO CONTINUE MAINLY SOUTH OF A GREENVILLE/SULPHUR SPRINGS-GRANBURY-COMANCHE LINE THROUGH MID-LATE MORNING. THIS WILL NOT INCLUDE THE DFW METRO AND POINTS NORTH...PER AFOREMENTIONED DRIER AIR FILTERING SOUTH OUT OF OKLAHOMA WITH DEEPER MIXING TO OCCUR. MID-HIGH LEVEL RETURNS HAVE BEEN INCREASING ON REGIONAL RADAR AND WITHIN THE STRONG SOUTHWEST FLOW ALOFT ACROSS THE NORTHWEST COUNTIES... BUT ANY LIGHT PRECIPITATION THAT WOULD FALL FROM THESE HIGH DECKS WILL LIKELY EVAPORATE WELL BEFORE REACHING THE SHALLOW AND SATURATED FRONTAL INVERSION BELOW WITH VERY DRY AIR NOTED ON 00Z FWD SOUNDING JUST ABOVE THE FRONTAL INVERSION. WILL NOT INSERT POPS AT THIS TIME...BUT WILL MONITOR OBSERVATIONS CAREFULLY AS TEMPERATURES FALL INTO THE MID- UPPER 30S ACROSS THESE AREAS BY SUNRISE. EXPECT RAIN CHANCES TO END ACROSS THE CENTRAL TEXAS AND FAR SOUTHEAST COUNTIES BY AFTERNOON...AS THE SHORTWAVE OVER NEW MEXICO TRACKS EAST ACROSS OKLAHOMA AND THE SURFACE WAVE TO OUR SOUTH HEADS INTO THE NORTHERN GULF OF MEXICO. WITH THE ENSUING SUBSIDENCE...EXPECT AT LEAST PARTIAL SUNSHINE ACROSS THE WESTERN HALF OF THE AREA THIS AFTERNOON AND EVENING...WITH CLEARING OVERNIGHT. A SPLIT FLOW PATTERN DEVELOPS RIGHT ACROSS THE RED RIVER VALLEY AND NORTH TEXAS BY WEDNESDAY WITH SUBSEQUENT AND SHALLOW SURGES OF POLAR AIR BEING REINFORCED ACROSS THE CWA. HIGHS WILL BE IN THE 40S WITH 50S IN THE SOUTH THROUGH THE WEEK WITH THE AREA REMAINING DRY AND LITTLE PRECIPITATION EXPECTED. TWO PIECES OF SHORTWAVE ENERGY WITHIN BOTH THE SUBTROPICAL AND POLAR STREAMS MERGE ACROSS NEW MEXICO AND WEST TEXAS ON LATER THURSDAY INTO FRIDAY NIGHT...BUT IT APPEARS BEST MOISTURE WILL BE CONFINED WELL SOUTH OF OUR AREA AS THIS DISTURBANCE LIFTS ACROSS THE AREA. NO RAIN IS EXPECTED WITH ONLY INCREASING CLOUDINESS DURING THIS PERIOD. MEDIUM RANGE MODELS KEEP IT DRY AND SEASONABLE BY THE WEEKEND...THEN LOSE TOUCH WITH EACH OTHER ON SOLUTION HEADING INTO EARLY NEXT WEEK. WE HAVE MAINTAINED A DRY FORECAST FOR THE NEXT WEEK AND BEYOND. 05/ && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 45 28 45 29 48 / 10 5 5 5 5 WACO, TX 51 30 46 30 49 / 40 5 5 5 10 PARIS, TX 43 27 43 27 46 / 20 5 5 5 5 DENTON, TX 44 25 45 26 47 / 10 5 5 5 5 MCKINNEY, TX 43 24 44 27 46 / 10 5 5 5 5 DALLAS, TX 46 29 46 29 49 / 10 5 5 5 5 TERRELL, TX 47 29 44 28 49 / 20 5 5 5 5 CORSICANA, TX 49 30 46 30 50 / 40 5 5 5 10 TEMPLE, TX 53 31 47 31 50 / 50 5 5 5 10 MINERAL WELLS, TX 42 23 45 26 47 / 10 5 5 5 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 79/82
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1012 AM CST TUE JAN 1 2013 .DISCUSSION... HEAVIER PRECIP HAS SHIFTED OFFSHORE AND IS ALONG THE COLD FRONT OVER THE COASTAL WATERS OUT BEYOND 20NM. THE FRONT SHOULD CONTINUE TO MOVE SOUTHEAST THOUGH SLOWLY. PATCHY LIGHT RAIN WILL CONTINUE THIS MORNING MAINLY OVER THE SOUTHERN HALF OF THE AREA INTO THE EARLY AFTERNOON. AS LIFT WITH APPROACHING SHORTWAVE OVER THE HILL COUNTRY NEARS EXPECT THE PRECIP TO SHIFT EAST AND LIGHTEN. OVERCAST SKIES WILL PREVAIL THROUGH THE AFTERNOON HOURS BUT MAY BECOME BROKEN THIS EVENING IN THE NORTHWESTERN AREAS WITH MAINLY HIGH CLOUDS. THE LIGHT PRECIP AND COLD AIR ADVECTION SHOULD KEEP TEMPERATURES IN THE MID 40S TO MID 50S WITH NEAR STEADY TEMPERATURES. WILL LIKELY DO AN UPDATE AROUND 1130 OR NOON TO CLEAR OUT PRECIP IN THE WEST AND NORTHWEST. AS OF 1005 AM THIS MORNING GALVESTON HAS HAD A RECORD SETTING 3.99" OF RAIN AND IS STILL FALLING THOUGH LIGHTER NOW. 45 && .PREV DISCUSSION... /ISSUED 529 AM CST TUE JAN 1 2013/ UPDATE... SEE 12Z AVIATION DISCUSSION. AVIATION... MODELS DID NOT INITIALIZE PARTICULARLY WELL THIS MORNING SO CONFIDENCE IS RATHER LOW. WENT WITH A GFS/RAP BLEND. AREA OF HEAVY RAIN/TSRA ALONG THE COAST WILL MOVE OFFSHORE IN THE NEXT HOUR OR SO. THIS WILL LEAVE JUST SOME PATCHY LIGHT RAIN FOR THE NEXT COUPLE OF HOURS OVER THE REST OF SE TX. THE RAP MASS FIELDS KEEPS MOST OF THE RAIN AWAY FROM AREA TAF SITES. A PRE-FRONTAL TROUGH IS APPROACHING THE COAST WITH THE ACTUAL FRONT STILL LAGGING A FEW HOURS BEHIND. AM EXPECTING WINDS TO SHIFT TO THE NORTH AND INCREASE THIS MORNING. CIGS ARE THE OTHER ISSUE AND FCST SOUNDINGS ARE PESSIMISTIC WITH CIGS TODAY. WILL MAINTAIN LIFR CIGS THROUGH 18Z AND THEN SHOW IMPROVEMENT TO VFR CONDS BY MID AFTN. 43 PREV DISCUSSION... /ISSUED 451 AM CST TUE JAN 1 2013/ DISCUSSION... IT IS GOOD TO SEE RAIN ON THE RADAR ACROSS SE TX AS WE HEAD INTO THE NEW YEAR. IT LOOKS LIKE COLLEGE STATION MAY BE THE ONLY CLIMATE SITE WITH ABOVE NORMAL PRECIPITATION FOR THE YEAR WITH HOUSTON IAH...HOUSTON HOU AND GALVESTON ALL SHOWING RAINFALL DEFICITS TO END THE YEAR. THE OTHER CLIMATE NOTE IS THAT 2012 SHOULD GO DOWN AS THE WARMEST YEAR ON RECORD FOR HOUSTON. SEE MORE DETAILS IN THE CLIMATE SECTION. CURRENTLY HAVE A LINE OF SHOWERS AND THUNDERSTORMS FROM SW LA INTO SE TX AND ALONG THE UPPER TX COAST. MOST OF THE HEAVY RAINFALL SHOULD BE CONCENTRATED RIGHT ALONG THE IMMEDIATE COAST INCLUDING GALVESTON IS AND BOLIVAR. THIS ACTIVITY SHOULD SLOWLY MOVE EAST. A COLD FRONT IS SLOWLY PUSHING INTO THE AREA WITH A PRE-FRONTAL TROUGH STALLED ACROSS THE HOUSTON AREA. BROAD UPPER LEVEL TROUGH REMAINS OVER THE DESERT SW WITH SW JET FLOW FROM BIG BEND OF TX TO THE OHIO RIVER VALLEY. RIGHT REAR QUAD OF UPPER JET OR RIGHT ENTRANCE REGION SHOULD MOVE OVER TX TODAY AND WED BASED ON SHORT RANGE MODELS. OVERALL THE SET UP IS FAVORABLE FOR RAIN OR ELEVATED SHOWERS. DRIER AIR SHOULD MOVE INTO THE AREA LATER TODAY AND TONIGHT WHICH SHOULD KEEP PRECIP CHANCES CONFINED TO THE SOUTHERN HALF OF THE FORECAST AREA AND THE COASTAL WATERS. BASED ON 00Z MODEL SUITE THINK MAJORITY OF RAINFALL WILL REMAIN OFF THE COAST SO TAILORED POPS CLOSER TO THAT THINKING. THIS MEANS KEEPING 20/30 POPS IN THE FORECAST ALONG THE COAST THROUGH MID WEEK. WITH JET FLOW REMAINING SW THROUGH THE END OF THE WEEK...LIKELY HAVE MOSTLY CLOUDY CONDITIONS WHICH WITH COOLER AIRMASS WILL KEEP TEMPS A GOOD 5 DEGREES BELOW NORMAL. DECIDED TO SHIFT SOME 20 POPS INTO FRI NIGHT AND SAT MORNING. GFS SHOWS ANOTHER SHORTWAVE TROUGH PUSHING PAST THE AREA DURING THIS TIME WITH THE ECMWF SLOWER. SPLIT THE DIFFERENCES A BIT WITH THE TIMING OF THE DISTURBANCEBUT WHILE THERE MAY BE LARGE SCALE ASCENT FOR PRECIP...NOT SURE HOW MUCH MOISTURE WILL BE AVAILABLE. HIGH PRESSURE SHOULD BUILD INTO THE AREA AGAIN OVER THE WEEKEND. OVERALL EXPECT TEMPS TO CREEP UP TO NORMAL LEVELS FOR THE WEEKEND AND EARLY NEXT WEEK. SOUTHERLY RETURN FLOW AND INCREASED GULF MOISTURE IS NOT EXPECTED TO OCCUR UNTIL NEXT TUE. 39 MARINE... A PRE-FRONTAL TROUGH AND ASSOCIATED WIND SHIFT WAS APPROACHING THE COAST. A COLD FRONT LAGGED BEHIND...AND AT 2 AM THE FRONT EXTENDED FROM LUFKIN TO COLLEGE STATION. THE FRONT WILL CONTINUE TO SAG SOUTH AND THIS FEATURE SHOULD CROSS THE COAST BETWEEN 11-13Z. WINDS WILL QUICKLY SHIFT TO THE NORTH AND INCREASE TO GREATER THAN 20 KNOTS OVER THE GULF. AN SCA WILL REMAIN IN EFFECT FOR THE GULF WATERS THROUGH 21Z AND WILL LIKELY BE EXTENDED LONGER WITH THE AFTN UPDATE. AN SCEC WILL BE REQUIRED FOR THE BAYS TODAY. STRONG WINDS ARE EXPECTED FOR MOST OF THE WEEK AND SCA/SCEC FLAGS WILL BE NEEDED FOR MUCH OF THE WEEK AHEAD. TIDES ARE ABOVE NORMAL BUT OFFSHORE WINDS WILL LOWER TIDE LEVELS BY AFTERNOON AND TIDE LEVELS WILL REMAIN BELOW NORMAL ON THURSDAY. 43 CLIMATE... NO BIG SURPRISE WITH REGARD TO TEMPERATURES. DECEMBER 2012 WAS VERY WARM...AVERAGING 3 TO 5 DEGREES WARMER THAN THE 30 YEAR NORMALS. 2012 WILL ALSO HAVE THE DISTINCTION OF BEING THE WARMEST YEAR ON RECORD FOR THE CITY OF HOUSTON. THE UNOFFICIAL 2012 AVERAGE TEMPERATURE FOR THE CITY OF HOUSTON WAS 72.1 DEGREES. THE PREVIOUS WARMEST YEAR ON RECORD WAS 71.9 DEGREES IN 1962. FWIW...THE AVERAGE TEMPERATURE IN 2011 WAS 71.8 DEGREES WHICH WAS THE THIRD WARMEST YEAR ON RECORD. COLLEGE STATION HAD AN AVERAGE TEMPERATURE IN 2012 OF 71.6 DEGREES WHICH TIES LAST YEAR FOR THE WARMEST YEAR ON RECORD. THE CITY OF GALVESTON ALSO RECORDED IT`S WARMEST YEAR ON RECORD WITH AN AVERAGE TEMP OF 73.9 DEGREES. THE PREVIOUS WARMEST YEAR WAS 72.6 DEGREES BACK IN 2006. THE SIX WARMEST YEARS ON RECORD FOR GALVESTON HAVE OCCURRED SINCE 1994. HOBBY AIRPORT ALSO RECORDED IT`S WARMEST YEAR ON RECORD. THE AVERAGE ANNUAL TEMP WAS 72.6 DEGREES BESTING LAST YEARS RECORD VALUE OF 72.4 DEGREES. THE EIGHT WARMEST YEARS ON RECORD HAVE OCCURRED SINCE 1998. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 55 36 49 34 52 / 50 10 10 10 10 HOUSTON (IAH) 59 41 50 37 54 / 80 20 10 10 10 GALVESTON (GLS) 64 46 51 43 53 / 90 30 20 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH THIS EVENING FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...45
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
949 AM CST TUE JAN 1 2013 .UPDATE... AN UPPER LEVEL TROUGH CURRENTLY OVER THE TEXAS PANHANDLE IS INDUCING ENOUGH LIFT FOR SPRINKLES AND LIGHT RAIN TO DEVELOP ACROSS PARTS OF THE REGION. WITH DRIER AIR CONTINUING TO WORK IN FROM THE NORTH AND NORTHWEST...THE REMAINING PRECIP HAS NOW SHIFTED EAST OF A LINE FROM SHERMAN TO DALLAS TO TEMPLE. EXPECT THE SCATTERED LIGHT PRECIPITATION TO CONTINUE THIS MORNING WITH A SLIGHT CHANCE FOR LIGHT RAIN OVER THE EASTERN AND SOUTHEASTERN COUNTIES THIS AFTERNOON. EARLIER THIS MORNING...WE RECEIVED A FEW REPORTS OF VERY BRIEF AND LIGHT SLEET PELLETS FALLING WITH THE RAIN. THIS WILL ALSO BE POSSIBLE THROUGH THE MORNING HOURS. THE MAIN CHALLENGE FOR TODAY IS THE CLOUD COVER AND ITS EFFECTS ON TEMPERATURES. SHORT TERM MODELS SUCH AS THE RAP AND TEXAS TECH WRF SUGGEST PARTS /IF NOT ALL/ OF THE REGION WILL REMAIN SOCKED IN LOW CLOUDS FOR MUCH OF THE DAY...BUT THE MAIN DIAGNOSTIC MODELS WANT TO SCATTER MUCH OF THE REGION OUT THIS AFTERNOON...EXCEPT FOR MAYBE THE NORTHEASTERN COUNTIES. WITH THE UPPER LEVEL TROUGH SWINGING ACROSS OKLAHOMA TODAY AND NORTH TO NORTHWEST FLOW THROUGH THE MID LEVELS OF THE ATMOSPHERE...THIS IS OFTEN A SITUATION WHERE CLOUDS DO REMAIN AROUND FOR MUCH OF THE DAY AND TEMPERATURES STAY MUCH COOLER. HIGH CLOUDS STREAMING OVER THE AREA SHOULD ALSO WORK AGAINST EROSION OF THE LOWER LEVEL CLOUDS...BUT THE HIGH CLOUDS MAY SHIFT EAST THIS AFTERNOON AS THE UPPER LEVEL TROUGH CONTINUES MOVING EAST. EVEN THOUGH CONFIDENCE IN THIS SCENARIO IS NOT VERY HIGH DUE TO UNCERTAINTY ON IF AND WHERE THE CLOUDS WILL BREAK...HAVE DECIDED TO ADJUST THE SKIES TO MOSTLY CLOUDY AND CLOUDY FOR THE REMAINDER OF THE DAY. ALSO...ADJUSTED HIGH TEMPERATURES NORTH OF I-20 DOWN A FEW DEGREES BUT DID NOT ADJUST TEMPERATURES ELSEWHERE. OVERALL..THE FORECAST CALLS FOR A WARM-UP OF ABOUT 5 DEGREES FROM CURRENT TEMPERATURES...EXCEPT IN THE WEST WHERE THINNING CLOUDS THIS AFTERNOON MAY ALLOW TEMPS TO WARM ANOTHER 5-10 DEGREES. 82/JLD && .AVIATION... UPPER TROUGHING CONTINUES ACROSS THE CENTRAL AND SOUTHWESTERN CONUS TODAY PROVIDING SOUTHWEST FLOW ALOFT ACROSS NORTH TEXAS. MEANWHILE A BROAD AREA OF MID LEVEL CLOUDS WITH OCCASIONAL SPRINKLES WAS BEING GENERATED BY A SHORTWAVE LIFTING NORTHEAST ACROSS WEST TEXAS...AND PRECIPITATION MAY OCCASIONALLY REDUCE VISIBILITIES TO 5-6SM BEFORE MOVING EAST OF THE REGION LATER THIS MORNING. WILL LIKELY STICK WITH AT LEAST A TEMPO FOR LIGHT RAIN AND BR AT ALL LOCATIONS UNTIL 15Z. HEAVIER PRECIPITATION SHOULD REMAIN SOUTH OF TAF LOCATIONS WHERE DEEPER MOISTURE RESIDES. WINDS HAVE BECOME NORTH TO NORTHWEST AND SHOULD REMAIN AS SUCH...WITH SPEEDS GENERALLY 10-15 KT. CEILINGS ARE MORE OF A CHALLENGE TODAY AS CLOUD DECKS HAVE BEEN ALL OVER THE PLACE DURING THE PAST 12 HOURS. CONDITIONS HAVE SHOWN A GENERAL IMPROVING TREND THIS MORNING DUE TO COOLER DRIER AIR PUSHING IN FROM THE NORTH BEHIND A COLD FRONT. HOWEVER...WITH LIGHT PRECIP AND VARYING CIGS...TAF SITES WILL MOST LIKELY EXPERIENCE PERIODS OF MVFR DECKS THROUGH THE LATE MORNING HOURS. WILL NEED TO KEEP AN EYE ON THE AREA OF IFR CIGS OVER NORTHWESTERN COUNTIES...BUT AT THIS TIME FEEL IT WILL REMAIN FAIRLY ISOLATED TO THAT REGION. OTHERWISE WILL PLAN ON STICKING SOMEWHAT CLOSE TO GUIDANCE WITH RESPECT TO CONDITIONS IMPROVING TO VFR THIS AFTERNOON AS THE SHORTWAVE SHIFTS EAST OF THE REGION. 30 && .PREV UPDATE... .UPDATE... AREA OBS INDICATING THAT A FEW SPRINKLES MAY BE REACHING THE SURFACE THIS PAST HOUR...SO HAVE ADDED THAT WEATHER ELEMENT TO THE FORECAST FOR NORTHERN COUNTIES THROUGH MID MORNING...OR UNTIL THE RICHER SW FEED OF MID LEVEL MOISTURE SHIFTS FURTHER TO THE EAST. 05/ && .PREV DISCUSSION... /ISSUED 329 AM CST TUE JAN 1 2013/ POSITIVE-TILTED LONGWAVE TROUGH CONTINUES FROM ROCKIES INTO THE MISSISSIPPI VALLEY ALOFT. ONE SHORTWAVE WAS ROTATING NORTHEAST OUT OF NEW MEXICO WITH ANOTHER DROPPING SOUTH THROUGH WYOMING AND INTO COLORADO AND KANSAS. AT THE SURFACE...A WEAK FRONTAL WAVE WAS DRAPED NEAR THE I-10 CORRIDOR WITH A WEAK SURFACE LOW ACROSS SOUTH TEXAS. DRIER AIR WAS SLOWLY FILTERING ACROSS THE RED RIVER VALLEY INTO AREAS NORTH OF I-20. SHORT TERM FORECAST IS A BIT TRICKY THIS MORNING WITH COLD AIRMASS ONLY 1000-2000 FT DEEP ACROSS NORTH TEXAS...MORE SHALLOW THE FURTHER SOUTH OF I-20 YOU GO. PATCHY DENSE FOG AND DRIZZLE WAS OCCURRING WITHIN THE MORE SHALLOW COOL AIRMASS SOUTH OF THE I-20/30 CORRIDORS. ALSO...WEAK ISENTROPIC ASCENT WAS RESULTING IN SCATTERED AREAS OF VERY LIGHT RAIN ACROSS OUR CENTRAL TEXAS COUNTIES. WE EXPECT THE PATCHY DENSE FOG/RAIN/ DRIZZLE TO CONTINUE MAINLY SOUTH OF A GREENVILLE/SULPHUR SPRINGS-GRANBURY-COMANCHE LINE THROUGH MID-LATE MORNING. THIS WILL NOT INCLUDE THE DFW METRO AND POINTS NORTH...PER AFOREMENTIONED DRIER AIR FILTERING SOUTH OUT OF OKLAHOMA WITH DEEPER MIXING TO OCCUR. MID-HIGH LEVEL RETURNS HAVE BEEN INCREASING ON REGIONAL RADAR AND WITHIN THE STRONG SOUTHWEST FLOW ALOFT ACROSS THE NORTHWEST COUNTIES... BUT ANY LIGHT PRECIPITATION THAT WOULD FALL FROM THESE HIGH DECKS WILL LIKELY EVAPORATE WELL BEFORE REACHING THE SHALLOW AND SATURATED FRONTAL INVERSION BELOW WITH VERY DRY AIR NOTED ON 00Z FWD SOUNDING JUST ABOVE THE FRONTAL INVERSION. WILL NOT INSERT POPS AT THIS TIME...BUT WILL MONITOR OBSERVATIONS CAREFULLY AS TEMPERATURES FALL INTO THE MID- UPPER 30S ACROSS THESE AREAS BY SUNRISE. EXPECT RAIN CHANCES TO END ACROSS THE CENTRAL TEXAS AND FAR SOUTHEAST COUNTIES BY AFTERNOON...AS THE SHORTWAVE OVER NEW MEXICO TRACKS EAST ACROSS OKLAHOMA AND THE SURFACE WAVE TO OUR SOUTH HEADS INTO THE NORTHERN GULF OF MEXICO. WITH THE ENSUING SUBSIDENCE...EXPECT AT LEAST PARTIAL SUNSHINE ACROSS THE WESTERN HALF OF THE AREA THIS AFTERNOON AND EVENING...WITH CLEARING OVERNIGHT. A SPLIT FLOW PATTERN DEVELOPS RIGHT ACROSS THE RED RIVER VALLEY AND NORTH TEXAS BY WEDNESDAY WITH SUBSEQUENT AND SHALLOW SURGES OF POLAR AIR BEING REINFORCED ACROSS THE CWA. HIGHS WILL BE IN THE 40S WITH 50S IN THE SOUTH THROUGH THE WEEK WITH THE AREA REMAINING DRY AND LITTLE PRECIPITATION EXPECTED. TWO PIECES OF SHORTWAVE ENERGY WITHIN BOTH THE SUBTROPICAL AND POLAR STREAMS MERGE ACROSS NEW MEXICO AND WEST TEXAS ON LATER THURSDAY INTO FRIDAY NIGHT...BUT IT APPEARS BEST MOISTURE WILL BE CONFINED WELL SOUTH OF OUR AREA AS THIS DISTURBANCE LIFTS ACROSS THE AREA. NO RAIN IS EXPECTED WITH ONLY INCREASING CLOUDINESS DURING THIS PERIOD. MEDIUM RANGE MODELS KEEP IT DRY AND SEASONABLE BY THE WEEKEND...THEN LOSE TOUCH WITH EACH OTHER ON SOLUTION HEADING INTO EARLY NEXT WEEK. WE HAVE MAINTAINED A DRY FORECAST FOR THE NEXT WEEK AND BEYOND. 05/ && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 45 28 45 29 48 / 10 5 5 5 5 WACO, TX 51 30 46 30 49 / 40 5 5 5 10 PARIS, TX 43 27 43 27 46 / 20 5 5 5 5 DENTON, TX 44 25 45 26 47 / 10 5 5 5 5 MCKINNEY, TX 43 24 44 27 46 / 10 5 5 5 5 DALLAS, TX 46 29 46 29 49 / 10 5 5 5 5 TERRELL, TX 47 29 44 28 49 / 20 5 5 5 5 CORSICANA, TX 49 30 46 30 50 / 40 5 5 5 10 TEMPLE, TX 53 31 47 31 50 / 50 5 5 5 10 MINERAL WELLS, TX 42 23 45 26 47 / 10 5 5 5 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 75/82
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
529 AM CST TUE JAN 1 2013 .UPDATE... SEE 12Z AVIATION DISCUSSION. && .AVIATION... MODELS DID NOT INITIALIZE PARTICULARLY WELL THIS MORNING SO CONFIDENCE IS RATHER LOW. WENT WITH A GFS/RAP BLEND. AREA OF HEAVY RAIN/TSRA ALONG THE COAST WILL MOVE OFFSHORE IN THE NEXT HOUR OR SO. THIS WILL LEAVE JUST SOME PATCHY LIGHT RAIN FOR THE NEXT COUPLE OF HOURS OVER THE REST OF SE TX. THE RAP MASS FIELDS KEEPS MOST OF THE RAIN AWAY FROM AREA TAF SITES. A PRE-FRONTAL TROUGH IS APPROACHING THE COAST WITH THE ACTUAL FRONT STILL LAGGING A FEW HOURS BEHIND. AM EXPECTING WINDS TO SHIFT TO THE NORTH AND INCREASE THIS MORNING. CIGS ARE THE OTHER ISSUE AND FCST SOUNDINGS ARE PESSIMISTIC WITH CIGS TODAY. WILL MAINTAIN LIFR CIGS THROUGH 18Z AND THEN SHOW IMPROVEMNT TO VFR CONDS BY MID AFTN. 43 && .PREV DISCUSSION... /ISSUED 451 AM CST TUE JAN 1 2013/ DISCUSSION... IT IS GOOD TO SEE RAIN ON THE RADAR ACROSS SE TX AS WE HEAD INTO THE NEW YEAR. IT LOOKS LIKE COLLEGE STATION MAY BE THE ONLY CLIMATE SITE WITH ABOVE NORMAL PRECIPITATION FOR THE YEAR WITH HOUSTON IAH...HOUSTON HOU AND GALVESTON ALL SHOWING RAINFALL DEFICITS TO END THE YEAR. THE OTHER CLIMATE NOTE IS THAT 2012 SHOULD GO DOWN AS THE WARMEST YEAR ON RECORD FOR HOUSTON. SEE MORE DETAILS IN THE CLIMATE SECTION. CURRENTLY HAVE A LINE OF SHOWERS AND THUNDERSTORMS FROM SW LA INTO SE TX AND ALONG THE UPPER TX COAST. MOST OF THE HEAVY RAINFALL SHOULD BE CONCENTRATED RIGHT ALONG THE IMMEDIATE COAST INCLUDING GALVESTON IS AND BOLIVAR. THIS ACTIVITY SHOULD SLOWLY MOVE EAST. A COLD FRONT IS SLOWLY PUSHING INTO THE AREA WITH A PRE-FRONTAL TROUGH STALLED ACROSS THE HOUSTON AREA. BROAD UPPER LEVEL TROUGH REMAINS OVER THE DESERT SW WITH SW JET FLOW FROM BIG BEND OF TX TO THE OHIO RIVER VALLEY. RIGHT REAR QUAD OF UPPER JET OR RIGHT ENTRANCE REGION SHOULD MOVE OVER TX TODAY AND WED BASED ON SHORT RANGE MODELS. OVERALL THE SET UP IS FAVORABLE FOR RAIN OR ELEVATED SHOWERS. DRIER AIR SHOULD MVOE INTO THE AREA LATER TODAY AND TONIGHT WHICH SHOULD KEEP PRECIP CHANCES CONFINED TO THE SOUTHERN HALF OF THE FORECAT AND THE COASTAL WATERS. BASED ON 00Z MODEL SUITE THINK MAJORITY OF RAINFALL WILL REMAIN OFF THE COAST SO TAILORED POPS CLOSER TO THAT THINKING. THIS MEANS KEEPING 20/30 POPS IN THE FORECAST ALONG THE COAST THROUGH MID WEEK. WITH JET FLOW REMAINING SW THROUGH THE END OF THE WEEK...LIKELY HAVE MOSTLY CLOUDY CONDITIONS WHICH WITH COOLER AIRMASS WILL KEEP TEMPS A GOOD 5 DEGREES BELOW NORMAL. DECIDED TO SHIFT SOME 20 POPS INTO FRI NIGHT AND SAT MORNING. GFS SHOWS ANOTHER SHORTWAVE TROUGH PUSHING PAST THE AREA DURING THIS TIME WITH THE ECMWF SLOWER. SPLIT THE DIFFERENCES A BIT WITH THE TIMING OF THE DISTRURBANCE BUT WHILE THERE MAY BE LARGE SCALE ASCENT FOR PRECIP...NOT SURE HOW MUCH MOISTURE WILL BE AVAILABLE. HIGH PRESSURE SHOULD BUILD INTO THE AREA AGAIN OVER THE WEEKEND. OVERALL EXPECT TEMPS TO CREEP UP TO NORMAL LEVELS FOR THE WEEKEND AND EARLY NEXT WEEK. SOUTHERLY RETURN FLOW AND INCREASED GULF MOISTURE IS NOT EXPECTED TO OCCUR UNTIL NEXT TUE. 39 MARINE... A PRE-FRONTAL TROUGH AND ASSOCIATED WIND SHIFT WAS APPROACHING THE COAST. A COLD FRONT LAGGED BEHIND...AND AT 2 AM THE FRONT EXTENDED FROM LUFKIN TO COLLEGE STATION. THE FRONT WILL CONTINUE TO SAG SOUTH AND THIS FEATURE SHOULD CROSS THE COAST BETWEEN 11-13Z. WINDS WILL QUICKLY SHIFT TO THE NORTH AND INCREASE TO GREATER THAN 20 KNOTS OVER THE GULF. AN SCA WILL REMAIN IN EFFECT FOR THE GULF WATERS THROUGH 21Z AND WILL LIKELY BE EXTENDED LONGER WITH THE AFTN UPDATE. AN SCEC WILL BE REQUIRED FOR THE BAYS TODAY. STRONG WINDS ARE EXPECTED FOR MOST OF THE WEEK AND SCA/SCEC FLAGS WILL BE NEEDED FOR MUCH OF THE WEEK AHEAD. TIDES ARE ABOVE NORMAL BUT OFFSHORE WINDS WILL LOWER TIDE LEVELS BY AFTERNOON AND TIDE LEVELS WILL REMAIN BELOW NORMAL ON THURSDAY. 43 CLIMATE... NO BIG SURPRISE WITH REGARD TO TEMPERATURES. DECEMBER 2012 WAS VERY WARM...AVERAGING 3 TO 5 DEGREES WARMER THAN THE 30 YEAR NORMALS. 2012 WILL ALSO HAVE THE DISTINCTION OF BEING THE WARMEST YEAR ON RECORD FOR THE CITY OF HOUSTON. THE UNOFFICIAL 2012 AVERAGE TEMPERATURE FOR THE CITY OF HOUSTON WAS 72.1 DEGREES. THE PREVIOUS WARMEST YEAR ON RECORD WAS 71.9 DEGREES IN 1962. FWIW...THE AVERAGE TEMPERATURE IN 2011 WAS 71.8 DEGREES WHICH WAS THE THIRD WARMEST YEAR ON RECORD. COLLEGE STATION HAD AN AVERAGE TEMPERATURE IN 2012 OF 71.6 DEGREES WHICH TIES LAST YEAR FOR THE WARMEST YEAR ON RECORD. THE CITY OF GALVESTON ALSO RECORDED IT`S WARMEST YEAR ON RECORD WITH AN AVERAGE TEMP OF 73.9 DEGREES. THE PREVIOUS WARMEST YEAR WAS 72.6 DEGREES BACK IN 2006. THE SIX WAMREST YEARS ON RECORD FOR GALVESTON HAVE OCCURRED SINCE 1994. HOBBY AIRPORT ALSO RECORDED IT`S WARMEST YEAR ON RECORD. THE AVERAGE ANNUAL TEMP WAS 72.6 DEGREES BESTING LAST YEARS RECORD VALU OF 72.4 DEGREES. THE EIGHT WARMEST YEARS ON RECORD HAVE OCCURRED SINCE 1998. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 55 36 49 34 52 / 50 10 10 10 10 HOUSTON (IAH) 59 41 50 37 54 / 80 20 10 10 10 GALVESTON (GLS) 64 46 51 43 53 / 90 30 20 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 3 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY... MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
458 AM EST TUE JAN 1 2013 .SYNOPSIS... A COLD FRONT EXTENDED FROM NEW YORK TO MISSOURI EARLY THIS MORNING. THIS FRONT WILL MOVE SOUTHEAST THROUGH THE REGION THIS AFTERNOON AND TONIGHT. LOW PRESSURE WILL CROSS THROUGH THE GULF COAST REGION TODAY AND TONIGHT AND OFF THE SOUTHEAST COAST BY WEDNESDAY MORNING. A LARGE HIGH PRESSURE SYSTEM WILL COVER MUCH OF THE EASTERN UNITED STATES ON THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 435 AM EST TUESDAY... AREA RADARS WERE SHOWING EASTERN EDGE OF LARGE BAND OF PRECIPITATION OVER THE WESTERN COUNTY WARNING AREA...ALTHOUGH AT THE SURFACE NOT ALL OF THIS WAS REACHING THE GROUND. SURFACE DEW POINTS REMAINED WELL BE LOW CURRENT TEMPERATURES BUT WERE RISING SLOWLY THROUGH THE 20S. HAVE SLOWED DOWN ARRIVAL OF MORE WIDESPREAD PRECIPITATION. MODELS KEEP BEST PROBABILITY OF PRECIPITATION IN THE WESTERN AND SOUTHERN COUNTY WARNING AREA. ANY WINTER PRECIPITATION LOOKS TO BE CONFINED FROM SOUTHEAST WEST VIRGINIA INTO BATH AND ROCKBRIDGE COUNTIES. LARGE OF BAND OF RAIN EXTENDED FROM SOUTHERN WEST VIRGINIA TO NORTHERN LOUISIANA ALONG A BAROCLINIC ZONE AND ELONGATED AXIS OF VORTICITY. BEST LIFT SHIFTS SOUTH OF THE FORECAST AREA LATE TONIGHT. AS WINDS COME AROUND TO THE NORTHWEST AT THE SURFACE AND LOW LEVEL WITH THE PASSAGE OF A COLD FRONT TONIGHT...COLDER AIR MOVES INTO THE REGION AND WILL CHANGE MUCH OF WHAT IS LEFT OF THE PRECIPITATION TO SNOW. BUFKIT WAS SHOWING ENOUGH HIGH CLOUDS FOR ADEQUATE SEEDER- FEEDER PROCESS TO MAINTAIN SNOW IN THE MOUNTAINS AS THE PRECIPITATION ENDS. STAYED WITH COOLER GRIDDED LAMP GUIDANCE FOR TODAY WITH ALL THE CLOUDS AND PRECIPITATION. USED A BLEND OF GUIDANCE FOR LOWS TONIGHT. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 330 AM EST TUESDAY... EARLY WEDNESDAY MORNING...LINGERING LIGHT PRECIPITATION IS EXPECTED ON THE TAIL END OF THE EXITING SYSTEM. GUIDANCE IS SUGGESTING LIMITED...IF ANY SATURATED LAYERS IN THE PREFERRED DENDRITIC ZONE...SO FREEZING DRIZZLE IS POSSIBLE. WILL ONLY HAVE LIMITED COVERAGE ACROSS THE NORTHERN MOUNTAINS OF NORTH CAROLINA FOR A FEW HOURS AFTER SUNRISE. HIGH PRESSURE BUILDS OVER THE UPPER OHIO VALLEY BY WEDNESDAY EVENING AND SETTLES OF THE MID-ATLANTIC STATES BY THURSDAY MORNING. THIS WILL BRING DRY WEATHER TO MOST OF THE REGION. MODEL GUIDANCE HAS BEEN HINTING AT THE NORTHERN EXTENT OF A PRECIPITATION ASSOCIATED WITH A LOW MOVING ALONG THE GULF COAST TO REACH THE FAR SOUTHERN PORTION OF THE FORECAST AREA LATE WEDNESDAY NIGHT INTO THURSDAY. COMPARED TO 24 HOURS AGO...THERE HAS BEEN A NOTABLE SHIFT SOUTH IN MULTIPLES MODELS IN THE EXTENT OF THIS PRECIPITATION SO THAT NO OR VERY LITTLE ASSOCIATED PRECIPITATION REACHES THE AREA. GIVEN THE GOOD CONSENSUS OF THE MODELS...HAVE ADJUSTED OUR FORECAST ACCORDINGLY. WILL NOW ONLY HAVE A SLIGHT CHANCE OF LIGHT RAIN OR LIGHT SNOW IN THE NORTHERN MOUNTAIN AND FOOTHILLS OF NORTH CAROLINA DURING THIS TIME FRAME. THURSDAY NIGHT INTO FRIDAY OUR ATTENTION TURNS TOWARD THE GREAT LAKES AS A CLIPPER SYSTEM ENTERS INTO THE OHIO VALLEY. LIMITED MOISTURE WILL BE ASSOCIATED WITH IT...BUT WE EXPECT ENOUGH INSTABILITY FOR THE DEVELOPMENT OF SOME UPSLOPE SNOW SHOWERS IN THE PREFERRED UPSLOPE AREAS OF SOUTHEAST WEST VIRGINIA AND NEIGHBORING SECTIONS OF SOUTHWEST VIRGINIA. OUR PREVIOUS FORECAST INCLUDED THESE...AND WE WILL CONTINUE TO ADVERTISE THEM IN THIS ISSUANCE. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 230 PM EST MONDAY... HIGH PRESSURE WILL BUILD EAST OUT OF THE CENTRAL U.S. ON FRIDAY. THE 1030 MB SURFACE HIGH WILL REMAIN ACROSS THE REGION DURING THE WEEKEND. WITH THE HIGH CENTER SETTLING SOUTH AND A SOUTHWEST FLOW WILL CONTINUE TO MODERATE TEMPERATURES EARLY NEXT WEEK. ANOTHER STORM MAY SPREAD MOISTURE INTO OUR REGION OUT OF THE CENTRAL PLAINS AROUND THE MIDDLE OF NEXT WEEK. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... AS OF 1035 PM EST MONDAY... OVERALL MID DECK CANOPY CONTINUES ACROSS THE REGION TONIGHT WITH DRY AIR LIMITING BASES TO 8 KFT AND ABOVE. RADAR IS ALSO INDICATING LIGHT RETURNS MAKING THEIR WAY ACROSS THE FAR SW MOUNTAINS INTO THE AREA...BUT WITH THE LOW LEVELS STILL VERY DRY...DO NOT SEE MORE THAN LIGHT SPRINKLES OR A FEW SLEET PELLETS MAKING IT TO THE SURFACE UNTIL THE EARLY MORNING HOURS OF TUESDAY AS THE NEXT WAVE APPROACHES. MODELS CONTINUE TO SLOW DOWN ANY EASTWARD PROGRESSION OF PRECIP OVERNIGHT...LIKELY DUE TO SO MUCH DRY AIR AND ONLY LIGHT PRECIP GIVEN A LACK OF A WELL DEFINED SURFACE SYSTEM. GUIDANCE ALSO REMAINS A BIT WARMER PER LESS EVAPORATIVE COOLING PROVIDED BY ONLY VERY LIGHT PRECIP WITH EVEN THE LATEST RAP AND LOCAL WRF SOLUTIONS QUITE DRY UNTIL SHORTLY BEFORE DAYBREAK. HOWEVER...EARLIER MODEL INIT REMAINS ALL OVER THE PLACE UNDER SUCH A STRUNG OUT AREA OF DEEP MOISTURE ALONG THE SRN JET AND LIKELY HAVING A HARD TIME IN WHERE TO FOCUS PRECIP ATTM. THUS HAVE KEPT IN LIGHT MIXED PRECIP FOR MANY OF THE WESTERN SITES WITH PERHAPS A PERIOD OF VERY LIGHT FREEZING RAIN POSSIBLE IN THE VALLEYS AT KLWB/KBCB TOWARD DAWN BUT CONFIDENCE LOW. OTRW INCLUDING A BIT MORE IN THE WAY OF PL MENTION AT LEAST AT THE ONSET OVERNIGHT ACROSS THE WEST WHILE LEAVING THINGS MAINLY VFR UNTIL VERY LATE TONIGHT WITH ONLY SPOTTY -RA OUT EAST. PRECIPITATION WILL BECOME WIDESPREAD TUESDAY MORNING WITH A MUCH BETTER PROBABILITY OF MVFR OR EVEN IFR CONDITIONS...AND LOW TO MEDIUM CONFIDENCE THAT SITES FROM KBCB WESTWARD WILL SEE MIXED PRECIPITATION CHANGE TO RAIN BY LATE MORNING AS TEMPERATURES WARM. HOWEVER KLWB MAY GET STUCK AROUND FREEZING INTO THE AFTERNOON SO MAY BE TOUGH TO DISLODGE THE MIXED BAG THERE UNTIL PRECIP TAPERS OFF IN THE AFTERNOON. AS A SURFACE LOW PRESSURE SYSTEM PASSES THROUGH THE CAROLINAS TUESDAY AND TUESDAY NIGHT...COLDER AIR WILL MOVE INTO THE AREA. ON TUESDAY EVENING PRECIPITATION WILL CHANGE TO SNOW SHOWERS...WHICH WILL CONTINUE IN SOUTHEAST WEST VIRGINIA...INCLUDING KLWB AND KBLF INTO EARLY WEDNESDAY MORNING. COULD EVEN BE SOME SPOTTY LIGHT FREEZING RAIN OR PERHAPS SOME LIGHT SNOW FROM KBCB/KROA TO KLYH TUE NIGHT AS THE PRECIP ENDS. OTRW APPEARS IFR TO OCNL MVFR CIGS WILL PERSIST ACROSS MOST OF THE AREA TUESDAY NIGHT OR EARLY WEDNESDAY UNDER SLOWLY IMPROVING VSBYS AS PRECIPS ENDS OVERNIGHT. VFR WEATHER IS EXPECTED WEDNESDAY AFTERNOON INTO SATURDAY FOR MOST OF THE REGION. A LOW PRESSURE SYSTEM PASSING WELL TO THE SOUTH MAY BRING SUB-VFR CONDITIONS TO DAN ON THURSDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...DS LONG TERM...KK AVIATION...AMS/JH/NF
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
925 PM CST WED JAN 2 2013 .SHORT TERM...TONIGHT 925 PM CST WED JAN 2 2013 THE MAIN CONCERNS IN THE NEAR TERM ARE WITH THE PRECIPITATION TRENDS THROUGH THE EVENING AND OVERNIGHT HOURS. THE MAIN BAND OF SNOW ASSOCIATED WITH SOME LOW LEVEL WARM AIR ADVECTION AHEAD OF AN UPPER LEVEL TROUGH CONTINUES TO MOVE EAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION WITH SNOWFALL TOTALS REMAINING ON THE LIGHT SIDE. THIS 1-2 HOUR BAND OF SNOW HAS PRODUCED JUST A DUSTING OF SNOW WITH A FEW TENTHS OF AN INCH REPORTED IN SOUTHEAST MINNESOTA. RADAR TRENDS INDICATE THAT THIS BAND OF SNOW HAS BEEN DISSIPATING AS THE OVERALL LIFT WEAKENS TO THE EAST. CURRENT TRENDS SHOW THAT THE BACK EDGE OF THE SNOW SHOULD BE INTO CENTRAL WISCONSIN SOMETIME SHORTLY AFTER MIDNIGHT. WHAT HAPPENS AS THE SNOW ENDS IS A TOUGHER QUESTION. IN THE REGION WEST OF THE SNOW AND EAST OF THE COLD FRONT...THERE IS AN AREA WHERE LOW LEVEL SATURATION IS OCCURRING UNDER A SHARP INVERSION. THIS HAS LED TO THE FORMATION OF A LOW CLOUD DECK AND SOME PATCHY FOG THAT HAS MAINLY BEEN IN THE 1-4SM RANGE. THERE IS CONCERN THAT SOME PATCHY FREEZING DRIZZLE MAY OCCUR AS WELL AS THIS SATURATED LAYER APPEARS TO BE JUST WARM ENOUGH THAT ICE PRODUCTION MAY NOT BE OCCURRING. THERE DOES NOT APPEAR TO BE MUCH LOW LEVEL LIFT THOUGH TO PRODUCE ANY KIND OF PRECIPITATION. MPX RECEIVED A FEW REPORTS OF FREEZING DRIZZLE EARLIER IN THE EVENING...BUT THE THREAT OF IT APPEARS TO BE DIMINISHING GOING THROUGH THE REST OF THE NIGHT. MADE SOME CALLS TO COUNTY SHERIFF DEPARTMENTS IN SOUTHEAST MINNESOTA WHERE VISIBILITY HAS BEEN THE LOWEST AND THEY HAVE NOT HAD ANY ISSUES WITH ICING OUT THERE. SO...WILL CONTINUE TO KEEP AN EYE ON THIS BUT WILL KEEP THE MENTION OUT OF THE FORECAST FOR TONIGHT AND JUST LEAVE SOME FLURRIES IN THERE WITH THE LOWER CLOUDS. WINDS WILL SHIFT AROUND TO THE NORTHWEST QUICKLY TONIGHT AND APPEAR TO BE DOING SO FASTER THAN WHAT THE 02.22Z-03.01Z RAP HAD BEEN ADVERTISING. CEILINGS WILL PICK UP ONCE THE WIND SHIFT COMES THROUGH...SO ANY DRIZZLE THREAT WILL END AS THIS FEATURE COMES IN. SKIES WILL REMAIN GENERALLY CLOUDY INTO TOMORROW WITH COLD AIR ADVECTION KICKING IN FROM THE NORTHWEST BEHIND THE FRONT. .LONG TERM... 252 PM CST WED JAN 2 2013 THE OVERALL WARMING TREND LOOKS TO CONTINUE INTO THE LONG TERM FORECAST PERIOD. THE FLOW REGIME LOOKS TO BECOME A BIT MORE ZONAL ALONG THE INTERNATIONAL BORDER BY THE START OF NEXT WEEK...WITH A SHIFT TO SOUTHWEST FLOW IN THE OFFING FOR THE END OF THE WEEK. IN ADDITION...A CLOSED CIRCULATION OFF THE WEST COAST WILL MOVE ONSHORE SOMEWHERE NEAR CA OR THE BAJA BY TUESDAY MORNING. THIS SYSTEM WILL EVENTUALLY MOVE INTO OUR AREA...BUT MODELS DIFFER ON THE EVOLUTION AND TIMING OF THAT SYSTEM. EITHER WAY...IT IS LOOKING LIKE MUCH WARMER TEMPERATURES WILL OCCUR AHEAD OF THAT SYSTEM. IN FACT...THERE ARE SOME INDICATIONS THAT THE PRECIPITATION AHEAD OF IT WILL FALL AS RAIN. SO THIS SYSTEM DEFINITELY BEARS WATCHING. && .AVIATION...TONIGHT AND THURSDAY 536 PM CST WED JAN 2 2013 THE FOCUS AT THE TAF SITES IS WITH THE LIGHT SNOW AND IFR TO MVFR CONDITIONS THAT ARE EXPECTED TO LAST INTO TOMORROW. THE CURRENT EXPECTATION IS THAT THE MAIN BAND OF LIGHT SNOW...WHICH HAS ALREADY MOVED INTO RST...WILL QUICKLY MOVE THROUGH THIS EVENING WITH ABOUT A 2-4 HOUR PERIOD OF LIGHT SNOW OR FLURRIES. CEILINGS ARE BETWEEN 1-2KFT IN THIS SNOW BAND WITH VISIBILITY ONLY BRIEFLY DROPPING DOWN TO 3SM. AS THE SNOW COMES TO AN END...THERE WILL BE A PERIOD OF IFR CEILINGS THAT MOVES IN AHEAD OF THE COLD FRONT AND IT WILL COINCIDE WITH MOVE WESTERLY WINDS. CAN NOT RULE OUT THAT THERE WILL BE SOME FREEZING DRIZZLE THAT ACCOMPANIES THIS PERIOD AS WELL...BUT CONFIDENCE IS NOT HIGH THAT IT WILL OCCUR OR EVEN REGISTER POST-SNOWFALL. MORE CONFIDENT THAT THE IFR CONDITIONS WILL OCCUR AT RST THAN LSE WHERE IT WILL LIKELY BE IN THE 900FT TO 1200FT RANGE AND MORE BORDERLINE. AS NOTED IN THE OBSERVATIONS ACROSS WESTERN MINNESOTA...ONCE THE COLD FRONT COMES THROUGH THE WINDS WILL SHIFT AROUND TO THE NORTHWEST AT 10-15KT AND CEILINGS WILL IMPROVE UP TOWARD 1.5-2.5KFT. THESE MVFR CEILINGS APPEAR TO BECOME FAIRLY SPORADIC AS WELL AS THERE ARE AS MANY REPORTS OF 3.5KFT CEILINGS ACROSS WESTERN MINNESOTA AS THERE ARE MVFR REPORTS. PLAYED IT PESSIMISTIC AT THIS POINT GIVEN THAT THE IMPROVEMENTS TO VFR ARE LIKELY SHORT LIVED. THERE MAY BE SOME OFF AND ON FLURRIES THROUGH THE NIGHT AS WELL...BUT IT SHOULD NOT CAUSE ANY VISIBILITY LOWERINGS ON TOP OF WHERE THEY ALREADY ARE DUE TO THE FOG/LIGHT DRIZZLE. CONDITIONS ARE EXPECTED TO GRADUALLY IMPROVE TO VFR TOMORROW AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... 252 PM CST WED JAN 2 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM...MW AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
339 AM CST TUE JAN 1 2013 .SHORT TERM...TODAY THROUGH THURSDAY NIGHT 339 AM CST TUE JAN 1 2013 FORECAST CONCERNS THIS PACKAGE...WIND CHILLS THIS MORNING...LIGHT SNOW CHANCES WED/WED NIGHT...TEMPERATURES THRU THE PERIOD. 06Z DATA ANALYSIS HAD HIGH PRESSURE CENTERED OVER SOUTHWEST MN AND WESTERN IA...DRIFTING SLOWLY SOUTHEAST. SKIES WERE CLEAR OVER MN/IA/WI EAST OF THE SFC-850MB RIDGE AXIS. WITH CLEAR SKIES...LIGHT WINDS AND SNOW COVER...TEMPS WERE FALLING BELOW ZERO ACROSS MUCH OF MN/WESTERN WI/NORTHERN IA FOR SOME OF THE COLDEST TEMPS SO FAR THIS WINTER SEASON. WINDS ACROSS MUCH OF MN/IA/WI LIGHTER THAN EARLIER EXPECTED...WITH MOST WIND CHILLS EARLY THIS MORNING IN THE 0 TO -20 RANGE. WEST OF THE RIDGE AXIS...A STRATUS DECK WAS SPREADING EAST INTO SOUTHWEST MN/NORTHWEST IA. MODELS AGAIN LOOK TO HAVE INITIALIZED WELL FOR THEIR 01.00Z RUNS. SOLUTIONS AND SENSIBLE WEATHER OUTCOMES VERY SIMILAR THRU THE SHORT- TERM PERIOD THIS CYCLE. DPROG/DT OF 500MB HGTS AT 01.00Z SHOWED THE MODEL RUNS OF 30.00Z AND 31.00Z VERIFIED WELL WITH THE LARGE SCALE FLOW ACROSS NOAM/EASTERN PAC...BUT WERE A BIT SLOW/STRONG WITH THE SHORTWAVE FEATURE SHEARING NORTHEAST ACROSS THE CENTRAL PLAINS AND TOO WEAK/FAST WITH THE FEATURE ON THE OR COAST. SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY BY GFS THIS CYCLE. TRENDS OF THE FEATURES MENTIONED ABOVE HAVE LITTLE IF ANY IMPACT ON THE AREAS SHORT-TERM WEATHER. BETTER CONSISTENCY SEEN WITH THE SHORTWAVE TO DROP INTO THE NORTHERN PLAINS/UPPER MIDWEST TODAY/TONIGHT THEN SLIDE ACROSS THE REGION WED/WED NIGHT. TREND FAVORS FASTER OF EARLIER RUNS...WITH A MORE OPEN WAVE PASSING WED/WED NIGHT. MORE PROGRESSIVE PATTERN HAS MORE RIDGING ALOFT BUILDING INTO THE REGION BY THU NIGHT/FRI. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL REASONABLE WITH THE SFC MASS FIELDS OVER THE CENTRAL CONUS. MODELS ACTUALLY DOING ABOUT AS WELL AS CAN BE EXPECTED WITH THE STRATUS CLOUDS SPREADING INTO SOUTHWEST MN/NORTHWEST IA EARLY THIS MORNING. PER WV IMAGERY ALL LOOKED GOOD WITH THE SHORTWAVE DETAILS OVER NOAM/EASTERN PAC. HIGHER-RES MODELS DOING BETTER WITH THE CHILLY TEMPS ACROSS MN/IA/WI EARLY THIS MORNING WHILE COARSER RESOLUTION MODELS ON THE WARM SIDE. OVERALL NO ONE FAVORITE MODEL AND WITH ALL SHOWING SIMILAR TREND TOWARD A COMMON CONSENSUS OUT TO WED NIGHT/THU...FAVORED THE MODEL/ENSEMBLE CONSENSUS. SHORT-TERM FCST CONFIDENCE REMAINS GOOD THIS CYCLE. FOR THE SHORT TERM...WHAT TO DO WITH THE WIND CHILL ADVISORY IS AN ISSUE EARLY THIS MORNING. WITH LIGHTER WINDS THAN EARLIER EXPECTED...WIND CHILLS ARE STAYING MOSTLY ABOVE THE -20 MARK. WITH THE LIGHTER WINDS...TEMPS TRENDING COLDER MANY LOCATIONS. WITH THE COLDER TEMPS...ANY WIND AT ALL THRU ABOUT 15Z WOULD SEND WIND CHILLS BELOW -20. THUS WILL HANG ONTO ADVISORY FOR NOW. NEXT ISSUE IS THE MOISTURE/CLOUDS MOVING TOWARD THE AREA FROM EASTERN SD. MODELS BRING THIS MOISTURE INTO THE WEST SIDE OF THE FCST AREA LATE THIS MORNING...ACROSS MAINLY THE NORTHWEST 2/3 OF THE FCST AREA THIS AFTERNOON THEN MOVE IT EAST OF THE FCST AREA TONIGHT. TRENDED SKY GRIDS TO ACCOUNT FOR THESE CLOUDS TODAY/TONIGHT. LOW LEVEL WARM ADVECTION SPREADS ACROSS THE AREA TONIGHT WITH 925MB TEMPS IN THE -5 TO -9C RANGE BY 12Z WED. THIS ALONG WITH SOME SOUTHWEST GRADIENT WINDS AHEAD OF THE NEXT LOW/TROUGH MOVING ACROSS THE DAKOTAS INTO MN WILL KEEP TEMPS WARMER TONIGHT...EVEN AS SKIES BECOME MOSTLY CLEAR AFTER MIDNIGHT. MOISTURE WITH THE NEXT SFC-MID LEVEL TROUGH SPREADS SOUTHEAST ACROSS THE FCST AREA ON WED. WHAT LOWER LEVEL THERMO-DYNAMIC FORCING THERE IS MOSTLY MOVES ACROSS THE FCST AREA BEFORE THE DEEPER MOISTURE ARRIVES. MODELS SHOW THE COLUMN SATURATES TO AT LEAST 700MB THRU THU AFTERNOON/EVENING WITH AND AHEAD OF THE PASSING SFC-MID LEVEL TROUGH AXIS. MODEL CONSENSUS DOES HAVE SOME 500-300MB PV ADVECTION MOVING ACROSS THE AREA CENTERED ON 00Z THU ALONG WITH SOME WEAK 700-500MB QG CONVERGENCE. GIVEN THE MOISTURE SIGNAL...THE WEAK QG CONVERGENCE...RATHER DEEP CYCLONIC FLOW FOR CONVERGENCE AND SOME PV ADVECTION/DIVERGENCE ALOFT...MAINTAINED TREND OF VERY LIGHT SNOW LIKELY OVER THE NORTHWEST HALF OF THE FCST AREA WED AFTERNOON AND THE NORTHEAST 3/4 WED EVENING AS THE TROUGH APPROACHES/PASSES. ANY SNOW AMOUNTS FROM THIS SYSTEM STILL LOOK LIKE A DUSTING UP TO A HALF INCH. WITH SOME SFC-700MB MOISTURE AND CYCLONIC FLOW/CONVERGENCE LINGERING LATER WED NIGHT...ADDED MENTION OF SCT FLURRIES TO 06Z- 12Z THU FCST GRIDS. SUBSIDENCE/DRYING SPREAD ACROSS THE AREA THU. LOWER LEVEL COLD ADVECTION WED NIGHT/MUCH OF THU SENDS 925MB TEMPS BACK INTO THE -11C TO -14C RANGE FOR THU AFTERNOON. TEMPS LOOKING TO END UP NEARLY STEADY ON THU. WITH THE MORE PROGRESSIVE TROUGH AND MID LEVEL RIDGING BUILDING EAST INTO THE UPPER MIDWEST...MDT/STRONG 925-850MB WARM ADVECTION SPREADS ACROSS MN/IA/WI THU NIGHT. DEPENDING ON PRESSURE GRADIENT/BOUNDARY LAYER WINDS FOR MIXING AND STRENGTH OF LOW LEVEL INVERSION...LOWS THU NIGHT MAY BE IN THE EVENING WITH RISING TEMPS AFTER MIDNIGHT. THIS TREND CAN BE ADDED TO FCST GRIDS LATER AS DETAILS BECOME CLEARER. USING A MODEL/ENSEMBLE CONSENSUS...GENERALLY FAVORED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR HIGHS/LOWS TODAY THRU THU NIGHT. WITH CLOUDS AND SOME GRADIENT WINDS FOR MIXING...DID LEAN TOWARD WARMER OF GUIDANCE LOWS WED NIGHT. .LONG TERM...FRIDAY THROUGH MONDAY 339 AM CST TUE JAN 1 2013 01.00Z MEDIUM RANGE MODELS IN BETTER AGREEMENT WITH EACH OTHER FRI/SAT AS RIDGING BUILDS ACROSS THE REGION FRI THEN A DEEPENING TROUGH MOVES ACROSS ON SAT. SOME CONSENSUS FOR WEAK AND TRANSIENT SHORTWAVE RIDGING OVER THE UPPER MIDWEST SUN BEFORE ANOTHER NORTHERN STREAM...WEST/ NORTHWEST FLOW SHORTWAVE TROUGH MOVES INTO THE REGION MONDAY. LONG-TERM FCST CONFIDENCE IS AVERAGE. BULK OF THE ENERGY WITH THE SAT TROUGH LOOKS TO PASS WEST/SOUTH OF THE FCST AREA...WITH MOISTURE ALSO TRENDING TO BE ON THE LIMITED SIDE. PER MODEL CONSENSUS...LEFT SAT DRY. THE MONDAY SYSTEM ALSO LOOKS MOISTURE STARVED AT THIS TIME WITH BULK OF THE ENERGY PASSING WELL NORTH OF THE FCST AREA AND SOURCE REGION FOR THE LOWER LEVEL AIRMASS THE CENTRAL/NORTHERN PLAINS. LEFT MON DRY AS WELL. WITH THE POLAR JET SHIFTING NORTH OF THE AREA...KEEPING THE ARCTIC AIR BOTTLED UP IN NORTHERN/EASTERN CAN...TEMPS FOR FRI THRU MONDAY LOOKING TO MODERATE WITH REPEATED ROUNDS OF LOW LEVEL WARM ADVECTION AND PREVAILING FLOW MAINLY WESTERLY. PERHAPS A BRIEF COOL-DOWN WITH THE PASSING TROUGH SAT/SAT NIGHT BUT MDT/STRONG LOW LEVEL WARM ADVECTION QUICKLY RETURNS FOR SUN. GIVEN PLENTY OF DETAIL DIFFERENCES...MODEL/ENSEMBLE CONSENSUS HIGHS/LOWS FOR FRI-MON LOOK GOOD AT THIS TIME. && .AVIATION...THROUGH 06Z WEDNESDAY 1117 PM CST MON DEC 31 2012 CLOUD DECK OVER SOUTH DAKOTA ON THE BACK SIDE OF THE RIDGE AXIS CONTINUES TO HOLD TOGETHER THIS EVENING. IT HAS BEEN SLOWLY MOVING EAST AND THE 01.00Z NAM NOW SUGGESTS THIS MOISTURE FIELD WILL MOVE OVER THE AREA TUESDAY AFTERNOON. THE 01.03Z RAP ALSO SHOWS THIS TREND SO WILL INCLUDE A MVFR CEILING DEVELOPING AT KRST AROUND 18Z AND KLSE AROUND 21Z. ONCE IT IS IN PLACE...WOULD EXPECT IT TO PERSIST THROUGH THE EVENING. VFR CONDITIONS WILL PREVAIL UNTIL THE CLOUDS ARRIVE WITH THE WINDS SLOWLY COMING AROUND TO THE SOUTHWEST ON THE BACK SIDE OF THE RIDGE AXIS. && .ARX WATCHES/WARNINGS/ADVISORIES... 339 AM CST TUE JAN 1 2013 WI...NONE. MN...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ079- 086>088-094>096. IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ008> 010-018-019-029. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1117 PM CST MON DEC 31 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT 210 PM CST MON DEC 31 2012 FORECAST FOCUS IS ON THE DANGEROUS WIND CHILLS TONIGHT...THEN THE LIGHT SNOW CHANCES FOR WED/WED NIGHT. COLD AIR IS MOVING IN...WITH 850 MB TEMPS EXPECTED TO TUMBLE FROM -10 C THIS AFTERNOON TO -14 C BY TUE MORNING. WITH MOSTLY CLEAR SKIES AIDED BY HIGH PRESSURE BUILDING IN FROM THE PLAINS...RADIATIONAL COOLING WILL HELP TEMPS FALL OFF A FEW MORE DEGREES. MORNING LOWS WILL BE IN THE SINGLE DIGITS/LOW TEENS BELOW ZERO. WINDS WILL LIGHTEN UP...BUT STIR ENOUGH IN OPEN AND UNSHELTERED AREAS THAT WIND CHILLS WILL BE A WEATHER CONCERN. SOUTHEAST MN/NORTHEAST IA CAN EXPECT 20 TO 25 BELOW WIND CHILLS FROM MIDNIGHT THROUGH ABOUT MID MORNING ON NEW YEARS. DANGEROUS ON A NORMAL NIGHT...MORE SO WITH NEW YEAR/S EVE DRAWING MANY MANY PEOPLE OUT FOR THE EVENING. WIND CHILL ADVISORIES WILL CONTINUE FOR THE AFOREMENTIONED AREAS. NAM/GFS/ECMWF HAVE BEEN CONSISTENT IN SLIDING A TROUGH ACROSS THE UPPER MISSISSIPPI RIVER VALLEY FOR WED/WED NIGHT...WITH A PIECE OF ENERGY SPINNING ACROSS IOWA AND ANOTHER STAYING NORTH...ACROSS SOUTHERN CANADA. DECENT QG CONVERGENT RESPONSE IN THE 300-500 MB LAYER BETWEEN 18Z WED-06Z THU TIME FRAME VIA THE GFS/NAM...BUT NOT MUCH THERMODYNAMIC FORCING. NORTHWEST-SOUTHEAST RUNNING X-SECTIONS SATURATE THROUGH AT LEAST 600 MB AS THE TROUGH MOVES IN...A BIT DEEPER IN THE GFS. DENDRITIC ZONE GROWTH REGION IS SMALL...BUT COLD ENOUGH FOR ICE AND THUS SNOW FOR PCPN TYPE. AN ASSOCIATED SFC BOUNDARY WITH THE UPPER LEVEL FORCING WILL MOVE ACROSS THE FORECAST AREA IN THE LATE AFTERNOON/EARLY EVENING HOURS...WHICH COULD AID IN LIFT ALTHOUGH LITTLE 2-D FRONTOGENETIC RESPONSE IS INDICATED AT THIS TIME. OVERALL...DYNAMICS ARE RATHER WEAK AS THE TROUGH MOVES ACROSS THE FORECAST AREA. THAT SAID...THERE LOOKS TO BE ENOUGH SATURATION FOR THE SHORTWAVE TO TAP INTO AND PRODUCE SOME LIGHT SNOW. THIS IS SHAPING UP TO BE A WIDESPREAD VERY LIGHT SNOW/FLURRY EVENT WITH MINIMAL IF ANY ACCUMULATION. .LONG TERM...FRIDAY THROUGH MONDAY 210 PM CST MON DEC 31 2012 SIZABLE DIFFERENCES FOR THE UPCOMING WEEKEND WITH THE GFS AND GEM BRINGING A SHORTWAVE INTO THE PAC NW...DRIVING IT EASTWARD TO ACROSS THE REGION ON SAT. BOTH MODELS DROP MORE ENERGY FROM NORTHERN CANADA INTO THE WAVE...HELPING DEEPENING THE TROUGH AS IT APPROACHES. MEANWHILE THE ECMWF IS MUCH SLOWER WITH THIS PAC NW SHORTWAVE...NOT BRINGING IT ACROSS THE AREA UNTIL SUNDAY NIGHT. IT ALSO NEVER DEVELOPS A CONNECTION TO ANY ENERGY FARTHER NORTH. NOT MUCH QPF PRODUCED VIA THE GFS/GEM...WITH NONE VIA THE EC. WITHOUT A LOT OF CONFIDENCE IN EITHER OF THE SOLUTIONS...WILL STICK WITH THE CONSENSUS SOLUTION FOR NOW. && .AVIATION...THROUGH 06Z WEDNESDAY 1117 PM CST MON DEC 31 2012 CLOUD DECK OVER SOUTH DAKOTA ON THE BACK SIDE OF THE RIDGE AXIS CONTINUES TO HOLD TOGETHER THIS EVENING. IT HAS BEEN SLOWLY MOVING EAST AND THE 01.00Z NAM NOW SUGGESTS THIS MOISTURE FIELD WILL MOVE OVER THE AREA TUESDAY AFTERNOON. THE 01.03Z RAP ALSO SHOWS THIS TREND SO WILL INCLUDE A MVFR CEILING DEVELOPING AT KRST AROUND 18Z AND KLSE AROUND 21Z. ONCE IT IS IN PLACE...WOULD EXPECT IT TO PERSIST THROUGH THE EVENING. VFR CONDITIONS WILL PREVAIL UNTIL THE CLOUDS ARRIVE WITH THE WINDS SLOWLY COMING AROUND TO THE SOUTHWEST ON THE BACK SIDE OF THE RIDGE AXIS. && .ARX WATCHES/WARNINGS/ADVISORIES... 210 PM CST MON DEC 31 2012 WI...NONE. MN...WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST TUESDAY FOR MNZ079-086>088-094>096. IA...WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 9 AM CST TUESDAY FOR IAZ008>010-018-019-029. && $$ SHORT TERM...RIECK LONG TERM....RIECK AVIATION...04
AREA FORECAST DISCUSSION
NWS WICHITA KS
300 AM CST THU JAN 3 2013 .DISCUSSION... MAIN FORECAST CHALLENGES WILL BE PRECIP CHANCES FRI NIGHT AND TEMPS IN THE NEAR TERM. SYNOPSIS: POSITIVELY TILTED UPPER TROUGH EXTENDS FROM THE WESTERN GREAT LAKES INTO THE SOUTHERN ROCKIES. A CLOSED UPPER LOW IS SLOWING TRACKING THROUGH NORTHERN BAJA. LAST BUT NOT LEAST ANOTHER CLOSED LOW IS NOW APPROACHING THE NORTHERN CA COAST. AT THE SURFACE HIGH PRESSURE IS CENTERED OVER THE ROCKIES AND EXTENDS INTO THE HIGH PLAINS WITH A SURFACE LOW OVER THE WESTERN GREAT LAKES. TODAY-TONIGHT: THE UPPER TROUGH IS EXPECTED TO SLOWLY SLIDE EAST THROUGH THESE PERIODS. AT THE SAME TIME THE CLOSED LOW OVER BAJA IS EXPECTED TO SLOWLY SLIDE EAST AND WILL BE OVER THE DESERT SOUTHWEST BY FRI MORNING. THIS SETUP WILL KEEP THE BELOW NORMAL TEMPS IN PLACE WITH HIGHS TODAY FAIRLY CLOSE TO WHERE THEY WERE ON WED. FRI-SAT: THE UPPER LOW OVER THE DESERT SOUTHWEST IS EXPECTED TO LIFT NORTHEAST ON FRI WITH GOOD MODEL AGREEMENT THAT IT WILL BE LOCATED OVER EASTERN KS/EASTERN OK BY 12Z SAT. WENT AHEAD AND INSERTED SOME FLURRIES FOR AREAS ALONG AND SOUTHEAST OF THE TURNPIKE FOR FRI NIGHT AS THIS FEATURE SLIDES OVER THE AREA. THE MAIN REASON THIS WAVE IS NOT EXPECTED TO BRING MORE THAN THIS IS BECAUSE OF LACK OF MOISTURE. ON SAT THIS UPPER IMPULSE WILL MOVE OFF INTO THE OHIO VALLEY AS A MUCH WEAKER PIECE OF ENERGY DIVES SOUTHEAST OUT OF THE NORTHERN ROCKIES. TEMPS ARE EXPECTED TO MODERATE SOME INTO THE WEEKEND AS THEY CREEP CLOSER TO SEASONAL AVERAGES. SUN-WED: THERE IS GOOD MODEL AGREEMENT THAT THE SPLIT FLOW PATTERN WILL CONTINUE THROUGH THESE EXTENDED PERIODS. BY MON MORNING ONE SHORTWAVE WILL BE MOVING OUT OF THE PACIFIC NW WHILE A CLOSED LOW TRACKS OVER SOUTHERN CA. THE SOUTHERN STREAM SYSTEM IS THE ONE WE ARE GOING TO HAVE TO WATCH AS IT MOVES INTO THE SOUTHERN HIGH PLAINS BY TUE NIGHT. THERE IS SOME DISCREPANCIES BETWEEN THE GFS AND ECMWF WITH REGARDS TO THIS CLOSED LOW...WITH THE ECMWF FURTHER NORTH WITH ITS POSITION AND ALSO A BIT SLOWER. FOR NOW WILL LEAVE IN PRECIP CHANCES FOR WED WITH THE THINKING THESE WILL BE ADJUSTED SEVERAL TIMES WITH LATER FORECAST SHIFTS. A GRADUAL WARMING TREND IS STILL ANTICIPATED AS WE START NEXT WEEK WITH 50S POSSIBLE BY TUE. LAWSON && .AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU THE MAIN CONCERN FOR THIS TAF PERIOD WILL BE THE POTENTIAL AND EXTENT FOR A MVFR CLOUD DECK. A CURRENT MVFR DECK CAN BE FOUND UPSTREAM IN WESTERN NEBRASKA...WITH THE CLOUDS SHIFTING SOUTHWARD. HOWEVER...THERE IS NO CERTAINTY IF THIS DECK WILL EVEN REACH KRSL AND KSLN OR ANY OTHER SITES GIVEN NAM AND RUC MODELS BREAKING IT UP BEFORE REACHING THEM. SINCE A SOUTHWARD SHIFTING CLOUD DECK IS AT LEAST PRESENT...OPTED TO INSERT AN OVC DECK THAT STRADDLES VFR AND MVFR BY 12Z. ADDITIONALLY THERE MAY BE PATCHY AREAS OF FOG TO IMPACT KRSL AND KSLN GIVEN THE RADIATION OVER THE SNOW PACK...BUT LEFT THIS OUT OF THE TAFS SINCE THERE IS VERY MINIMAL CERTAINTY IN ITS OCCURRENCE AT THE TAF SITE. A SECOND VFR CLOUD DECK HAS BEGUN TO SLIDE THROUGH THE REST OF THE TAF SITES. OPTED TO INPUT A MVFR DECK IN FOR KCNU GIVEN GUIDANCE AND THE IMPACT OF THE CURRENT CLOUD COVER STARTING AT 12Z THEN BKN A FEW HOURS LATER. ALL SITES SHOULD SCATTER OR EVEN CLEAR OUT IN THE EARLY TO MID AFTERNOON. IT IS VERY POSSIBLE THAT THERE WILL NEED TO BE MODIFICATIONS MADE TO THE FORECAST TO BETTER TIME THESE CLOUDS DECKS AS WELL AS ALTER CIGS ACCORDINGLY. VP && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 33 12 37 26 / 0 0 0 10 HUTCHINSON 31 11 35 25 / 0 0 0 10 NEWTON 31 12 36 26 / 0 0 0 10 ELDORADO 32 12 37 25 / 0 0 0 10 WINFIELD-KWLD 35 14 40 27 / 0 0 10 10 RUSSELL 29 3 34 13 / 0 0 0 10 GREAT BEND 30 6 34 18 / 0 0 0 10 SALINA 29 8 34 21 / 0 0 0 10 MCPHERSON 30 10 35 24 / 0 0 0 10 COFFEYVILLE 37 15 40 26 / 0 0 0 10 CHANUTE 34 14 37 25 / 0 0 0 10 IOLA 33 14 37 26 / 0 0 0 10 PARSONS-KPPF 36 14 39 25 / 0 0 0 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1154 PM CST WED JAN 2 2013 .UPDATE... ADDED PATCHY FOG FOR CENTRAL KANSAS GIVEN THE RADIATION OVER THE SNOW COVER WHICH HAS CREATED REDUCED VISIBILITIES IN ELLSWORTH ALREADY. DO NOT ANTICIPATE A WIDESPREAD EVENT. ADK && .AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU THE MAIN CONCERN FOR THIS TAF PERIOD WILL BE THE POTENTIAL AND EXTENT FOR A MVFR CLOUD DECK. A CURRENT MVFR DECK CAN BE FOUND UPSTREAM IN WESTERN NEBRASKA...WITH THE CLOUDS SHIFTING SOUTHWARD. HOWEVER...THERE IS NO CERTAINTY IF THIS DECK WILL EVEN REACH KRSL AND KSLN OR ANY OTHER SITES GIVEN NAM AND RUC MODELS BREAKING IT UP BEFORE REACHING THEM. SINCE A SOUTHWARD SHIFTING CLOUD DECK IS AT LEAST PRESENT...OPTED TO INSERT AN OVC DECK THAT STRADDLES VFR AND MVFR BY 12Z. ADDITIONALLY THERE MAY BE PATCHY AREAS OF FOG TO IMPACT KRSL AND KSLN GIVEN THE RADIATION OVER THE SNOW PACK...BUT LEFT THIS OUT OF THE TAFS SINCE THERE IS VERY MINIMAL CERTAINTY IN ITS OCCURRENCE AT THE TAF SITE. A SECOND VFR CLOUD DECK HAS BEGUN TO SLIDE THROUGH THE REST OF THE TAF SITES. OPTED TO INPUT A MVFR DECK IN FOR KCNU GIVEN GUIDANCE AND THE IMPACT OF THE CURRENT CLOUD COVER STARTING AT 12Z THEN BKN A FEW HOURS LATER. ALL SITES SHOULD SCATTER OR EVEN CLEAR OUT IN THE EARLY TO MID AFTERNOON. IT IS VERY POSSIBLE THAT THERE WILL NEED TO BE MODIFICATIONS MADE TO THE FORECAST TO BETTER TIME THESE CLOUDS DECKS AS WELL AS ALTER CIGS ACCORDINGLY. VP && .PREV DISCUSSION... /ISSUED 515 PM CST WED JAN 2 2013/ AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU MVFR CLOUDS WILL BE THE MAIN ISSUE FOR THIS TAF FORECAST PERIOD. A MVFR DECK IS STILL HANGING AROUND UPSTREAM AND MAY SLIDE SOUTHWARD TOWARDS KRSL AND KSLN...SO OPTED TO LEAVE IN SCATTERED DECKS JUST IN CASE. THERE HAS BEEN SOME MVFR CIGS FOR KICT AS WELL WHICH ARE SLOWLY ERODING. KEPT IN A TEMPO JUST IN CASE FOR THE NEXT COUPLE OF HOURS DUE TO TWO AREAS OF NEAR MVRF CIGS IN THE NORTHEASTERN PART OF THE COUNTY AND NEAR KINGMAN. A COUPLE OF MODELS ARE STILL HINTING AT MVFR CIGS BETWEEN 10-13Z ON THURSDAY FOR ALL BUT KCNU...HOWEVER THERE IS STILL A LACK OF CONFIDENCE DUE TO INCONSISTENCIES. THUS KEPT THE SCATTERED MVFR MENTION FOR NOW AND WILL UPDATE IN THE NEXT FORECAST ISSUANCE IF NEEDED. WINDS WILL STAY NORTHWEST AT SPEEDS OF 5 TO 10KTS. VP PREV DISCUSSION... /ISSUED 313 PM CST WED JAN 2 2013/ DISCUSSION... THE MAIN FORECAST CONCERN IS THE TEMPERATURE FORECAST THROUGH THE NEXT FEW DAYS. SYNOPSIS: A DEEP POSITIVELY TILTED TROUGH IS SITUATED OVER THE CENTRAL CONUS. THIS TROUGH IS THE COMBINATION OF A COUPLE OF DIFFERENT PV ANOMALIES. YET ANOTHER DISTURBANCE IS CUT OFF FROM THE MAIN FLOW ALONG THE AXIS OF THE POSITIVELY TILTED TROUGH...OVER THE BAJA PENINSULA. TONIGHT - FRIDAY: THE UPPER LEVEL PATTERN REMAINS QUITE ACTIVE...BUT NOT IMPACTING OUR PRECIPITATION FORECAST MUCH. THE MAIN THING IS THAT IT WILL KEEP COLD AIR IN THE REGION THROUGH THE END OF THE WEEK. THE MAIN TROUGH BECOMES EVEN MORE POSITIVELY TILTED AS THE NORTHERN PORTION OF THE WAVE MOVES EAST WHILE THE REMAINDER STAYS CONNECTED TO CUT OFF LOW OVER THE SOUTHWEST. SURFACE HIGH PRESSURE WILL MOVE IN BEHIND THIS UPPER WAVE AND TRAVERSE THE AREA LATE THURSDAY AFTERNOON/THURSDAY NIGHT. TEMPERATURES TONIGHT AND TOMORROW NIGHT WILL BE COOL WITH THE SNOW COVER AND LIGHT WINDS. THINK TONIGHT LOWS WILL BE IN THE SINGLE DIGITS/LOW TEENS. DO NOT THINK FRIDAY MORNING WILL BE QUITE AS COLD AS EXPECTED DURING YESTERDAYS FORECAST AS THE SURFACE HIGH WILL MOVE ACROSS EARLIER...BUT STILL LOW SINGLE DIGITS EXPECTED OVER CENTRAL KANSAS. WINDS WILL STILL BE LIGHT UNDER CLEAR SKIES...BUT DO NOT EXPECT THEM TO BE CALM TO ALLOW FOR MAXIMUM RADIATIONAL COOLING. AFTER A WARMER THAN EXPECTED MAXIMUM FORECAST TODAY...THE REINFORCING SHOT OF AIR TOMORROW WILL KEEP TEMPERATURES COOLER. BY FRIDAY THE UPPER WAVE WILL PULL COMPLETELY EAST...LEAVING SOME ENERGY CUT-OFF OVER NEW MEXICO. SATURDAY - WEDNESDAY: BY THE WEEKEND THE CUT-OFF LOW PREVIOUSLY MENTIONED WILL MOVE EAST/NORTHEAST ACROSS TEXAS AND OKLAHOMA WHILE ANOTHER DISTURBANCE DIVES SOUTHEAST INTO THE CENTRAL PLAINS. THE WAVE DIVING SOUTHEAST WILL KICK THE CUT-OFF LOW EASTWARD AND OUT OF THE AREA. THE NAM IS A BIT QUICKER WITH THE FRONT ASSOCIATED WITH THIS SYSTEM THAN THE ECMWF AND GFS...HAVE CONTINUED TO USE A BLEND OF THE GUIDANCE DUE TO THESE DISCREPANCIES. TEMPERATURES WILL WARM AHEAD OF THE WAVE AND REACH NEAR NORMAL FOR THE WEEKEND. THE LATEST 12Z/ECMWF DOES HINT AT SOME PRECIPITATION DEVELOPMENT AHEAD OF THE FRONT OVER SOUTHEAST KANSAS...BUT CONFIDENCE ON THIS FEATURE IS LOW AND HAVE LEFT THE FORECAST DRY FOR SATURDAY AFTERNOON. BEHIND THESE DISTURBANCES UPPER LEVEL RIDGING WILL BUILD IN AND HELP TEMPERATURES CONTINUE TO INCREASE THROUGH THE EARLY PART OF THE WEEK. THE NEXT BIG SYSTEM TO IMPACT THE AREA WILL BE MID-WEEK NEXT WEEK. THE GUIDANCE OVER THE PAST COUPLE DAYS HAVE INDICATED ANOTHER CUT-OFF LOW TO BEGIN TO EJECT EASTWARD TOWARD THE AREA...BUT THE TIMING HAS BEEN AWRY AMONG THE DIFFERENT MODELS. NOW THINGS HAVE CHANGED WITH THE LATEST RUNS...THE GFS HAS GRADUALLY SLOWED DOWN...WHILE THE ECMWF HAVE SPED UP. THIS PUTS THE TIMING OF THE WAVE IN THE MODELS MUCH NEARER TO EACH OTHER...GIVING SLIGHTLY HIGHER CONFIDENCE TO THE TIMING. HOWEVER...WITH THAT BEING SAID...THE DISCREPANCIES WITH THE SYSTEM AS OF LATE AND THESE JUST BEING THE LATEST RUNS...DID TAPER THE POPS SOME FOR DAY 7. STILL HAVE CHANCE POPS...BUT LOW CHANCE POPS. THIS SYSTEM WILL BE ONE TO WATCH OVER THE NEXT WEEK...COULD BE THE NEXT BIG PRECIPITATION PRODUCER...IF THINGS PAN OUT AS THEY ARE INDICATING NOW. BILLINGS && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 16 30 12 39 / 10 0 0 10 HUTCHINSON 14 29 10 38 / 10 0 0 10 NEWTON 15 29 12 36 / 10 0 0 10 ELDORADO 15 31 12 38 / 10 0 0 10 WINFIELD-KWLD 17 32 14 39 / 0 0 0 10 RUSSELL 9 25 2 31 / 10 0 0 0 GREAT BEND 10 26 7 32 / 10 0 0 0 SALINA 11 27 7 35 / 10 0 0 0 MCPHERSON 13 28 10 37 / 10 0 0 0 COFFEYVILLE 18 35 16 40 / 0 0 0 10 CHANUTE 17 33 14 37 / 10 10 0 10 IOLA 18 33 14 36 / 10 10 0 10 PARSONS-KPPF 18 34 14 38 / 10 0 0 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
104 AM EST THU JAN 3 2013 .SYNOPSIS...A DISTURBANCE MOVING OFF THE GREAT LAKES MAY SPAWN SCATTERED LIGHT SNOW SHOWERS LATER TODAY AND TONIGHT. OTHERWISE...SEASONABLY COLD WEATHER WILL CONTINUE INTO THE WEEKEND. && .NEAR TERM /THROUGH TODAY/... NO CHANGES NEEDED TO THE NEAR TERM PD FOR THE POST MIDNGT UPDATE. PREVIOUS... BASED ON BLEND OF RECENT SURFACE AND SATELLITE DATA ALONG WITH RECENT RAP AND SREF MODEL OUTPUT...EXPECT BANDS OF JETSTREAK- RELATED CIRROSTRATUS TO CONTINUE TO MOVE EASTWARD ACROSS THE UPPER OHIO VALLEY OVERNIGHT. WITH SURFACE LAYER REMAINING RATHER DRY WITH SNOWPACK UNDERNEATH...NOCTURNAL RADIATIONAL COOLING SHOULD BE ONLY SLIGHTLY REDUCED. DID MAKE ADDITIONAL MINOR UPWARD ADJUSTMENTS TO OVERNIGHT TEMPERATURES...AS EVENING TEMPERATURE FALL HAS BEEN SLOWER THAN EARLIER THOUGHT. THIS STILL YIELDED LOWS IN THE 5 TO 15 RANGE FOR MOST LOCALES...WHICH WAS GENERALLY 5 DEGREES WARMER THAN WHAT THE STATISTICAL GUIDANCE SUCH AS GFS AND NAM MOS SHOWED. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... MODELS CONTINUE TO EXHIBIT PASSAGE OF A WEAK...MSTR LTD...POSITIVELY TILTED SHRTWV TROF LATER TODAY. AS SUCH...EVEN WITH SOME LIFT...PRECIPITATION WILL BE DIFFICULT TO GENERATE AND POPS WERE MAINTAINED AT SLGT...TO CHC NMBRS OVR NRN AND RIDGE ZONES. COLD AIR IS PROGGED TO RMN ENTRENCHED OVR THE AREA INTO THE WEEKEND...WITH A STRONG CONSENSUS ON NORTHWESTERLY FLOW BEING THE MAIN PLAYER IN THE FORECAST. AS SUCH...THINGS SHOULD REMAIN DRY WITH CONTINENTAL AIR IN CONTROL. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... RELATIVELY QUIET WEATHER EXPD FOR THE LONG TERM PD. A WK COLD FRONT IS EXPD TO MOVE THROUGH THE RGN SUNDAY. WL KEEP CHC POPS FOR SHSN...WITH SLIGHTLY HIGHER POPS IN THE NORTH WHERE SOMEWHAT DEEPER MOISTURE IS FCST. COULD SEE A FEW SHSN IN NW FLOW BEHIND THE FRONT BUT H8 FLOW QUICKLY TURNS ANTICYCLONIC CUTTING OFF ANY REMAINING SHSN. HIGH PRES BLDS IN SUN NT THROUGH WED...WITH SEVERAL LOW PRES SYSTEMS PASSING BY WELL TO OUR NORTH. SHOULD SEE A SLOW WARMING TREND AS WELL BY NEXT WEEK...ALTHOUGH PREFERRED TO STAY ON THE COOL SIDE OF GUIDANCE...OR SLIGHTLY BELOW. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... MOST TERMINALS WILL BE UNDER HIGH OVERCAST SKIES...ALTHOUGH SOME SLIGHT CLEARING IS POSSIBLE FROM NORTHWEST TO SOUTHEAST. HIGH CLOUDS WILL PERSIST INTO THE DAYTIME HOURS. ALTHOUGH WINDS WILL BE NEARLY CALM TONIGHT...EXPECT SW GUSTS TO PICK UP TO AT LEAST 20 KTS THIS AFTERNOON. A COLD FRONT APPROACHING TONIGHT WILL BE WEAKENING...BUT SHOULD STILL BRING LOW VFR/HIGH MVFR CIGS OVERNIGHT. BEST CHANCE FOR ANY LIGHT SNOW SHOWERS WITH THE SYSTEM WILL BE AT FKL/DUJ. .OUTLOOK.../FRIDAY THROUGH MONDAY/... CEILING RESTRICTIONS SHOULD END FRIDAY AS HIGH PRESSURE BUILDS IN. RESTRICTIONS ARE POSSIBLE AGAIN SATURDAY NIGHT AND SUNDAY AS A WEAK COLD FRONT MOVES ACROSS THE GREAT LAKES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 15/33
AREA FORECAST DISCUSSION
NWS BISMARCK ND
101 AM CST THU JAN 3 2013 .DISCUSSION... SURFACE HIGH PRESSURE RIDGE EXTENDS NORTH FROM ITS PARENT SURFACE HIGH PRESSURE CENTER OVER NORTHERN COLORADO TO ACROSS WESTERN NORTH DAKOTA. STRONG UPPER LEVEL RIDGE ANCHORED OVER THE WESTERN CONUS. WAA OVER MY NORTHWEST WHERE RETURN FLOW WEST OF THE SFC RIDGE HAS DEVELOPED. EXTENSIVE AREA OF LOW CLOUDS REMAINS ACROSS MUCH OF WEST AND CENTRAL NORTH DAKOTA ALONG WITH ISOLATED FLURRIES BEING REPORTED AT TIMES OVER VARIOUS OBSERVING SITES ACROSS THE CWA. CLOUDS HAVE KEPT OUR TEMPERATURES UP THIS MORNING...AND HAVE SIGNIFICANTLY INCREASED MORNING TEMPERATURES VERY NEAR THE 05Z RAP MODEL WHICH CAPTURES THE CURRENT SITUATION THE BEST. WHILE CLOUDS SHOULD CLEAR/TREND SCATTERED OVER MY WEST AND NORTH NOW THROUGH 12Z...WAA WILL CONTINUE TO SPREAD SOUTH AND EAST ALONG WITH SUFFICIENT MIXING TO KEEP TEMPERATURES FROM BOTTOMING OUT AS SKIES CLEAR. MAIN UPDATES WITH THIS FORECAST PACKAGE WAS INCREASING MORNING TEMPERATURES...MAINTAINING/EXPANDING ISOLATED FLURRIES ALL AREAS THROUGH 12Z...AND ADJUSTING SKY COVER BASED ON LATEST SATELLITE IMAGERY. && .AVIATION...AT 11 PM CST...AN AREA OF HIGH PRESSURE OVER EASTERN MONTANA INTO SASKATCHEWAN WAS MOVING EAST. A LARGE AREA OF MVFR CEILINGS EXTENDED ACROSS ALL OF WEST AND CENTRAL NORTH DAKOTA. MVFR CONDITIONS ARE FORECAST AT ALL TAF SITES TONIGHT. CONDITIONS GRADUALLY BECOMING VFR FROM NORTHWEST TO SOUTHEAST BETWEEN 08-14Z. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1249 AM EST THU JAN 3 2013 .SYNOPSIS... HIGH PRESSURE CROSSES OVERNIGHT. CLIPPER LIKE SYSTEM PASSES THURSDAY NIGHT. TWO UPPER SHORT WAVES PASS THIS WEEKEND...FOLLOWED BY HIGH PRESSURE. && .NEAR TERM /THROUGH TODAY/... 1230 AM UPDATE... FCST ON TRACK. 630PM UPDATE... OVERNIGHT LOWS CONTINUE TO BE THE TRICKY PART OF THE FORECAST. SHOULD LOSE THE HIGH LEVEL CIRRUS TOWARDS THE END OF THE OVERNIGHT FOR LOCATIONS UP TO THE MOUNTAINS...SO WILL DROP IN GOOD RADIATION CONDITIONS. SREF PICKING UP ON STRATUS CLIPPING OUR EXTREME NORTHWEST COUNTIES IN SOUTHEAST OHIO OVERNIGHT...AND LOW LEVEL CLOUDS ON THE FAR EASTERN SLOPES IN POCAHONTAS COUNTY. PREVIOUS DISCUSSION... HEATING HAS ALLOWED STRATOCU TO FORM THIS AFTN...MOST PREVALENT ACROSS SE OH AND N WV. LINGERING LLVL MOISTURE UNDER INVERSION PROVIDING FOR A DREARY DAY ACROSS SW VA WITH LOW CIGS AND SOME FOG. WILL ALLOW STRATOCU TO DISSIPATE WITH LOSS OF SUN AS CIRRUS BLOW-OFF RIDING JET FROM SW INVADES TONIGHT. SOME CONCERN WITH LOW STRATUS HANGING TOUGH ACROSS SE OH AND N WV PER RUC SOUNDINGS BUT OTHER MDLS NOT REALLY SHOWING THIS. FOR TEMPS WILL HEDGE THAT CIRRUS IS NOT OPAQUE ENOUGH TO HINDER FALL TOO MUCH. LOOKING AT TEENS AND LWR 20S FOR MOST PART FOR OVERNIGHT LOWS. DRY CONDITIONS PREVAIL TOMORROW WITH A MAINLY SUNNY SKY...SAVE FOR PERHAPS PORTIONS OF SW VA TOWARD DICKENSON CO WHERE LOW CLOUDS MAY LINGER THROUGH THE MORNING. HIGHS REBOUND SOME WITH EVERYONE OUTSIDE OF HIGHER ELEVATIONS IN THE 30S. SOME CLDS MAY SNEAK INTO SE OH TOWARD EVENING FROM AN APPROACHING CLIPPER TYPE FRONT. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... VERY PROGRESSIVE AND DRY PATTERN THIS PERIOD. MODELS HAVE A MOISTURE STARVED SHORT WAVE AND COLD FRONT IN THE NORTHERN STREAM DROPPING RAPIDLY SOUTHEAST ACROSS THE OHIO VALLEY THURSDAY NIGHT AND EARLY FRIDAY. A THERMAL TROUGH IN NORTHWEST FLOW BEHIND THE FRONT PROMPTS SMALL POPS FOR SNOW SHOWERS MAINLY THURSDAY NIGHT...AND MOSTLY IN THE MOUNTAINS...WITH LITTLE IF ANY ACCUMULATIONS. THEN...A QUIET PERIOD WITH MODERATING TEMPERATURES LATER FRIDAY AND SATURDAY AS A LOW AMPLITUDE UPPER RIDGE BUILDS OVER THE AREA. IT WILL BE JUST AFTER THIS PERIOD BEFORE THE NEXT SYSTEM CAN AFFECT US. LOOK FOR BELOW NORMAL TEMPS THURSDAY NIGHT AND FRIDAY BEHIND THE FRONT...MODERATING CLOSE TO NORMAL ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... STRONG SHORT WAVE WILL MOVE ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY. BUFKIT SOUNDING CONTINUE TO INDICATE SATURATED SFC TO BARELY BELOW MINUS 10C LEVEL...SUGGESTING GOOD CHANCES FOR LIGHT SNOW FOLLOWED BY FREEZING DRIZZLE AS THE SYSTEM PULLS NORTHEAST. NORTHWEST BACKWARDS TRAJECTORIES FROM SUNDAY RETURNS FROM IL AND WI...BRINGING MUCH COLD AIR...CAPABLE TO SQUEEZE LOW LEVEL MOISTURE INTO THE MOUNTAINS...TO PRODUCE LIGHT UPSLOPE SNOW OR FREEZING DRIZZLE PER SHALLOWER MOISTURE IN THE COLUMN WITH NO LAKE CONNECTION BELOW MINUS 10C. THEREFORE...KEPT POPS TO CHANCE FOR NOW ACROSS THE NORTHERN HALF OF OUR CWA THROUGH SATURDAY NIGHT DIMINISHING BY EARLY MONDAY. TWEAKED HPC GUIDANCE FOR TEMPS THROUGH THE PERIOD...ACCOUNTING FOR CLOUD COVER AND GFS H850 COLDER TEMPERATURES. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... OTHER THAN SOME MVFR RIVER VALLEY MIST OVERNIGHT...VFR FCST AS HIGH PRESSURE REIGNS. WEAK CLIPPER SYSTEM WILL INCREASE W FLOW SFC AND ALOFT A BIT...AND BRING PATCHY STRATOCU LATE THU AND THU NT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY... FORECAST CONFIDENCE: HIGH. ALTERNATE SCENARIOS: MVFR RIVER VALLEY MIST MAY BE MORE OR LESS PREVALENT THAN FCST OVERNIGHT. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE THU 01/03/13 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z FRIDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/TRM/JMV/30 NEAR TERM...TRM/30/26 SHORT TERM...JMV LONG TERM...ARJ AVIATION...TRM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1129 PM CST WED JAN 2 2013 .SHORT TERM...TONIGHT 925 PM CST WED JAN 2 2013 THE MAIN CONCERNS IN THE NEAR TERM ARE WITH THE PRECIPITATION TRENDS THROUGH THE EVENING AND OVERNIGHT HOURS. THE MAIN BAND OF SNOW ASSOCIATED WITH SOME LOW LEVEL WARM AIR ADVECTION AHEAD OF AN UPPER LEVEL TROUGH CONTINUES TO MOVE EAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION WITH SNOWFALL TOTALS REMAINING ON THE LIGHT SIDE. THIS 1-2 HOUR BAND OF SNOW HAS PRODUCED JUST A DUSTING OF SNOW WITH A FEW TENTHS OF AN INCH REPORTED IN SOUTHEAST MINNESOTA. RADAR TRENDS INDICATE THAT THIS BAND OF SNOW HAS BEEN DISSIPATING AS THE OVERALL LIFT WEAKENS TO THE EAST. CURRENT TRENDS SHOW THAT THE BACK EDGE OF THE SNOW SHOULD BE INTO CENTRAL WISCONSIN SOMETIME SHORTLY AFTER MIDNIGHT. WHAT HAPPENS AS THE SNOW ENDS IS A TOUGHER QUESTION. IN THE REGION WEST OF THE SNOW AND EAST OF THE COLD FRONT...THERE IS AN AREA WHERE LOW LEVEL SATURATION IS OCCURRING UNDER A SHARP INVERSION. THIS HAS LED TO THE FORMATION OF A LOW CLOUD DECK AND SOME PATCHY FOG THAT HAS MAINLY BEEN IN THE 1-4SM RANGE. THERE IS CONCERN THAT SOME PATCHY FREEZING DRIZZLE MAY OCCUR AS WELL AS THIS SATURATED LAYER APPEARS TO BE JUST WARM ENOUGH THAT ICE PRODUCTION MAY NOT BE OCCURRING. THERE DOES NOT APPEAR TO BE MUCH LOW LEVEL LIFT THOUGH TO PRODUCE ANY KIND OF PRECIPITATION. MPX RECEIVED A FEW REPORTS OF FREEZING DRIZZLE EARLIER IN THE EVENING...BUT THE THREAT OF IT APPEARS TO BE DIMINISHING GOING THROUGH THE REST OF THE NIGHT. MADE SOME CALLS TO COUNTY SHERIFF DEPARTMENTS IN SOUTHEAST MINNESOTA WHERE VISIBILITY HAS BEEN THE LOWEST AND THEY HAVE NOT HAD ANY ISSUES WITH ICING OUT THERE. SO...WILL CONTINUE TO KEEP AN EYE ON THIS BUT WILL KEEP THE MENTION OUT OF THE FORECAST FOR TONIGHT AND JUST LEAVE SOME FLURRIES IN THERE WITH THE LOWER CLOUDS. WINDS WILL SHIFT AROUND TO THE NORTHWEST QUICKLY TONIGHT AND APPEAR TO BE DOING SO FASTER THAN WHAT THE 02.22Z-03.01Z RAP HAD BEEN ADVERTISING. CEILINGS WILL PICK UP ONCE THE WIND SHIFT COMES THROUGH...SO ANY DRIZZLE THREAT WILL END AS THIS FEATURE COMES IN. SKIES WILL REMAIN GENERALLY CLOUDY INTO TOMORROW WITH COLD AIR ADVECTION KICKING IN FROM THE NORTHWEST BEHIND THE FRONT. .LONG TERM... 252 PM CST WED JAN 2 2013 THE OVERALL WARMING TREND LOOKS TO CONTINUE INTO THE LONG TERM FORECAST PERIOD. THE FLOW REGIME LOOKS TO BECOME A BIT MORE ZONAL ALONG THE INTERNATIONAL BORDER BY THE START OF NEXT WEEK...WITH A SHIFT TO SOUTHWEST FLOW IN THE OFFING FOR THE END OF THE WEEK. IN ADDITION...A CLOSED CIRCULATION OFF THE WEST COAST WILL MOVE ONSHORE SOMEWHERE NEAR CA OR THE BAJA BY TUESDAY MORNING. THIS SYSTEM WILL EVENTUALLY MOVE INTO OUR AREA...BUT MODELS DIFFER ON THE EVOLUTION AND TIMING OF THAT SYSTEM. EITHER WAY...IT IS LOOKING LIKE MUCH WARMER TEMPERATURES WILL OCCUR AHEAD OF THAT SYSTEM. IN FACT...THERE ARE SOME INDICATIONS THAT THE PRECIPITATION AHEAD OF IT WILL FALL AS RAIN. SO THIS SYSTEM DEFINITELY BEARS WATCHING. && .AVIATION...THROUGH 06Z FRIDAY 1129 PM CST WED JAN 2 2013 THE MAIN SNOW HAS ENDED AT THE TAF SITES...BUT SCATTERED FLURRIES WILL PERSIST INTO THE MORNING AND EARLY AFTERNOON HOURS ON THURSDAY. IFR CEILINGS AT RST ARE EXPECTED TO IMPROVE TO MVFR QUICKLY OVERNIGHT AS WINDS SHIFT TO THE NORTHWEST WITH DRIER NEAR SURFACE AIR MOVING IN. THESE 1-2.5KFT CEILINGS EXTEND WELL ACROSS MINNESOTA AND SHOULD LINGER INTO THURSDAY AFTERNOON AS WELL THOUGH A FEW BREAKS TO VFR WILL LIKELY OCCUR. WINDS WILL BECOME GUSTY OUT OF THE NORTHWEST OVERNIGHT AS A COLD FRONT MOVES THROUGH THE REGION WITH TOP GUSTS IN THE 18 TO 24KT RANGE. CONDITIONS ARE EXPECTED TO GRADUALLY IMPROVE THROUGH THE AFTERNOON THURSDAY AS THE SYSTEM THAT BROUGHT THE SNOW AND CLOUD COVER MOVES OFF TO THE EAST INTO THE GREAT LAKES. && .ARX WATCHES/WARNINGS/ADVISORIES... 252 PM CST WED JAN 2 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM...MW AVIATION...HALBACH
UPDATED FOR 12Z AVIATION FORECAST DISCUSSION.

&& .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 226 AM CST THU JAN 3 2013 DRY AND COLD CONDITIONS WILL CONTINUE THROUGH THE NEAR TERM. A STRUNG OUT POSITIVELY TILTED TROUGH STRETCHING FROM THE CENTRAL PLAINS TO THE UPPER MIDWEST...WILL EVENTUALLY SPLIT INTO TWO SEPARATE SYSTEMS. THE NORTHERN PIECE OF ENERGY WILL SCOOT EAST ACROSS THE GREAT LAKES...WHILE THE SOUTHERN CHUNK MOVES ACROSS OUR REGION. A WEAK SURFACE COLD FRONT WILL ACCOMPANY THIS FEATURE AND MOVE EAST ACROSS THE FORECAST AREA THIS MORNING. LOOKING UPSTREAM ACROSS NORTHERN PLAINS AND UPPER MIDWEST...PLENTY OF LOW CLOUDS TO DEAL WITH. MODELS SWING THIS MOISTURE SOUTHEAST TOWARD THE AREA THROUGHOUT THE DAY...BUT OTHER THAN THESE PASSING CLOUDS...NO PRECIPITATION IS EXPECTED. TEMPERATURES TODAY WILL AGAIN BE AFFECTED BY SNOW AND CLOUD COVER TODAY...WITH THE COLDEST READINGS PERSISTING OVER SOUTHERN ILLINOIS AND SW INDIANA. THE GFS IS A LITTLE MORE AGGRESSIVE WITH THE AMT OF MOISTURE HEADING INTO THE AREA FOR TODAY AND TONIGHT...AND THIS WILL HAVE AN AFFECT ON TEMPS AS WELL. ON FRIDAY AND FRIDAY NIGHT...AN UPPER LEVEL RIDGE WILL BUILD INTO THE REGION AHEAD OF THE NEXT UPPER LEVEL CLOSED LOW SYSTEM...WHICH DEVELOPS OVER NM/TX. THIS WILL ALLOW LOW LEVEL WINDS TO BECOME MORE WESTERLY/SOUTHWESTERLY WITH TIME...AND BY 00Z SATURDAY...TEMPS IN THE 1000-850MB LAYER RISE ABOVE ZERO IN PARTS OF SEMO. THEREFORE...WE SHOULD SEE HIGH TEMPS SEVERAL DEGREES HIGHER ON FRIDAY. CLOUDS WILL BE ON THE INCREASE...MAINLY FRIDAY NIGHT...WHICH WILL LIKELY KEEP LOWS FROM GETTING TOO COLD ESPECIALLY IN OUR WESTERN SECTIONS. THE AFOREMENTIONED CLOSED LOW IS FORECAST TO BE OVER THE CENTRAL PLAINS BY 12Z SATURDAY. IT THEN EJECTS NE ACROSS MO/IL THROUGH THE DAY. THE GFS IS MOST AGGRESSIVE WITH LIGHT QPF ACROSS THE ENTIRE AREA WITH THIS EVENT. THE NAM INDICATES SOME QPF OVER MAINLY WEST KY...AND ECMWF SPLIT BEST MOISTURE TO OUR NW AND SE. THERE AREA ALSO TIMING DIFFERENCES RIGHT NOW...WITH THE GFS INDICATING THE QPF ON SATURDAY MORNING...WHILE THE NAM INDICATES LATER IN THE DAY. EITHER WAY...IT APPEARS AS THOUGH THICKNESSES AND SOUNDING PROFILES SUGGESTS EITHER SPRINKLES OR SOME FLURRIES DEPENDING ON THE LOCATION. HIGH TEMPERATURES WILL BE TRICKY DUE TO ALL THE POTENTIAL CLOUD COVER AND POSSIBLE PRECIP. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 226 AM CST THU JAN 3 2013 THE EXTENDED PART OF THE FORECAST CONTINUES TO LOOK RELATIVELY QUIET. SATURDAY NIGHT WITH DECENT 1000-700MB MOISTURE...THE PASSAGE OF AN H5 SHORT WAVE...AND 1000-850MB CRITICAL THICKNESSES AOB 1300M... DECIDED TO THROW IN FLURRIES OVER THE NORTHEAST SECTIONS OF THE CWA. THE FLURRIES MAY LINGER OVER THE SAME AREA SUNDAY MORNING BUT WILL LEAVE OUT FOR NOW. IN THE WAKE OF THE SHORT WAVE PASSAGE SATURDAY NIGHT INTO SUNDAY... DEPENDING ON WHICH MODEL YOU PREFER...EITHER ZONAL FLOW OR WEAK RIDGING ALOFT EVENTUALLY EVOLVE INTO SOUTHWEST FLOW WHICH SHOULD KEEP THE REGION DRY WITH SLOWLY MODERATING TEMPERATURES. HOW THIS SCENARIO PLAYS OUT STILL NOT CLEAR BUT THE END RESULT SHOULD BASICALLY BE THE SAME. THE GFS PUSHES THE LOW AMPLITUDE RIDGE OFF TO THE EAST ON MONDAY...THEN KEEPS THE REGION IN SOUTHWEST FLOW ALOFT THROUGH THE END OF THE PERIOD WHEREAS THE ECMWF GENERALLY KEEPS THE AREA IN ZONAL FLOW ALOFT THROUGH TUESDAY...THEN BRINGS THE RIDGE OVERHEAD. IRONICALLY ENOUGH...EVEN WITH THE DISPARITY BETWEEN THESE TWO LONG RANGE MODELS...THEY BOTH SHOW THE NEXT CHANCE OF MEASURABLE PRECIPITATION IN THE FORM OF RAIN NEXT WEDNESDAY NIGHT...BUT THAT IS BEYOND THE SCOPE OF THIS FORECAST CYCLE...SO WILL NOT ELABORATE ANY FURTHER AT THIS TIME. TEMPERATURES WILL CONTINUE AOB NORMAL THROUGH MONDAY NIGHT...THEN WARM TO ABOVE NORMAL READINGS FROM TUESDAY THROUGH THE END OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 520 AM CST THU JAN 3 2013 SKIES ARE MAINLY CLEAR AND WINDS AS OF THIS WRITING. VSBYS VFR ATTM BUT WILL WATCH FOR ANY DIP NEAR SUNRISE. CONTINUE TO SEE SIGNS FOR A SCATTERED DECK 3-5KFT SLOWLY MOVING IN OVER MUCH OF THE AREA THROUGHOUT THE DAY...BUT THE MVFR SIGNAL IS NOT AS STRONG...EXCEPT OVER THE KEVV TERMINAL...OTHERWISE KEPT IT VFR. LATEST RAP MODEL SHOWS THIS DECK WILL TAKE A WHILE TO GET THERE (18Z OR SO) DUE TO THE DRY AIR IN PLACE. WEST WINDS WELL UNDER 10KTS WILL BE THE RULE TODAY. APPEARS AS THOUGH LOW LEVEL MOISTURE WILL LINGER INTO THE EVENING WITH THE PASSAGE OF AN UPPER TROUGH. NOT CERTAIN AT THIS POINT HOW EXTENSIVE THE CLOUD DECK MAY BECOME OR WHETHER OR NOT IT WILL BE VFR OR MVFR. KEPT THINGS OPTIMISTIC FOR NOW. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
525 AM CST THU JAN 3 2013 .DISCUSSION.../ISSUED AT 300 AM CST/ TEMPERATURE AND CLOUD FORECAST A BIT TRICKY FOR TODAY. CURRENTLY SEEING AN AREA OF CLEARING ACROSS THE EASTERN PORTION OF OUR CWA...WITH A LARGE AREA OF STRATUS LOCATED OVER THE CENTRAL AND WESTERN DAKOTAS. AS LOW LEVEL WINDS TURN MORE WESTERLY THINKING IS THAT THIS STRATUS TO THE WEST WILL MOVE ACROSS OUR CWA...ONLY SLOWLY DISSIPATING AS IT MOVES EAST. RAP SEEMS TO BE HANDLING THIS THE BEST AND THUS FOLLOWED CLOSER TO IT FOR CLOUD COVER TODAY. SLOWED DOWN THE EXIT OF THE CLOUDS...WITH CLEARING OUT WEST EXPECTED BY LATE MORNING...THE INTERSTATE 29 CORRIDOR EARLY TO MID AFTERNOON...AND NOT EXITING OUR EAST UNTIL LATE AFTERNOON OR EVENING. ALSO RAISED HIGH TEMPERATURES TODAY BY A FEW DEGREES. TEMPERATURES UNDER THE CURRENT STRATUS IN THE UPPER TEENS...AND AS IT MOVES BACK IN...THINKING MOST LOCATIONS GET AT LEAST TO THESE TEMPERATURES. WARMEST READINGS WILL BE WEST OF THE JAMES RIVER...WHERE AFTERNOON SUN SHOULD ALLOW HIGHS IN THE MID 20S. SHOULD SEE CLEAR SKIES BY TONIGHT. LOWS WILL BE TRICKY...AS A DECENT LOW LEVEL JET MOVES ACROSS OUR EASTERN AREAS. OVERALL THINKING SINGLE DIGITS AND TEENS FOR LOWS. THE WARMEST READINGS WILL BE NEAR AND DOWNWIND OF THE BUFFALO RIDGE...WHERE SUSTAINED SOUTHWESTERLY WINDS NEAR 20 KTS WILL KEEP THINGS MIXED. POTENTIAL EXISTS FOR LOWS NEAR ZERO IN THE INTERSTATE 29 CORRIDOR IF WE CAN DECOUPLE. DID TREND TOWARDS THE COOLER SIDE OF GUIDANCE HERE GIVEN SNOWCOVER AND CLEAR SKIES...BUT IF THE WINDS STAY UP JUST ENOUGH THEN CURRENT LOWS WILL LIKELY BE TOO COLD. WILL SEE A BIT OF RIDGING AND WARMING TEMPERATURES ALOFT ON FRIDAY. LOWERED HIGHS A BIT...GIVEN SNOW COVER AND EXPECTED WEAK MIXING PREVENTING US FROM REALIZING MUCH OF THE WARM AIR ALOFT. ALTHOUGH THE NAM SEEMS TOO COLD...AND THINKING WE STILL SEE UPPER 20S TO LOW 30S MOST SPOTS...WITH LOW 40S POSSIBLE IN OUR FAR SOUTHWEST. UPPER LEVEL TROUGH AND ANOTHER COLD SHOT MOVES IN ON SATURDAY. LOOKS LIKE WE SHOULD SEE SOME MORE STRATUS ON SATURDAY WITH THIS FEATURE. COULD SEE SOME FLURRIES AS WELL...BUT NOT EXPECTING ANYTHING MORE THAN THAT. MODELS DISAGREE SOME ON TIMING AND MAGNITUDE OF THE COLD SHOT...BUT HIGHS WILL LIKELY BE IN THE 20S MOST SPOTS. WE THEN SEE A WARMING TREND SUNDAY INTO THE MIDDLE OF NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS IN. SUNDAY WILL STILL BE COOL ON THE BACKSIDE OF THE TROUGH...WITH 20S EAST AND 30S SOUTHWEST. HOWEVER BY MONDAY INTO WEDNESDAY...EXPECT WARMING TEMPERATURES ALOFT AND FLOW FAVORABLE FOR DECENT MIXING. SO DESPITE SNOWCOVER...EXPECTING HIGHS TO RISE ABOVE FREEZING IN MOST LOCATIONS EACH DAY UNDER PARTLY TO MOSTLY SUNNY SKIES. MODELS IN GOOD AGREEMENT THAT A CUTOFF LOW OVER SOUTHERN CALIFORNIA ON MONDAY WILL PUSH EAST INTO THE SOUTHERN PLAINS BY MIDWEEK. AS IT IS PICKED UP BY THE UPPER FLOW AND TURNS NORTHEAST DISAGREEMENT ENTERS ON HOW FAR NORTHWEST IT GETS. THERE IS THUS THE POTENTIAL FOR SOME PRECIPITATION...PROBABLY WEDNESDAY NIGHT OR THURSDAY WITH THIS SYSTEM...SO WILL HAVE TO MONITOR TRENDS. AS IT LOOKS NOW...TEMPERATURE PROFILE MAY VERY WELL BE TOO WARM FOR SNOW...FAVORING A RAIN OR MIXED PRECIP THREAT IF ANYTHING. FLOW THEN TURNS FAVORABLE FOR MORE COLD AIR TO END NEXT WEEK. /CHENARD && .AVIATION.../FOR THE 12Z TAF ISSUANCE/ VFR CONDITIONS ALONG AND EAST OF I29 WILL BECOME MVFR CEILINGS DURING THE MORNING...AND THEN PERSIST THROUGH THE AFTERNOON...AND THEN BECOME VFR AGAIN AFTER 00Z TONIGHT. MVFR CEILINGS WEST OF I29 WILL GRADUALLY BECOME VFR FROM THE WEST DURING THE AFTERNOON HOURS. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
240 PM EST THU JAN 3 2013 .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... A SWATH OF PRECIP ASSOCIATED WITH A POST-FRONTAL WAVE IS BEGINNING A DECREASING TREND THIS AFTN. THE BAND OF PRECIP WILL SINK TO THE SOUTH TNGT/FRIDAY. MODELS DIFFER ON HOW MUCH FORCING AND SUBSEQUENT PRECIP WILL REMAIN AS THE WAVE NUDGES SOUTH. LATEST TRENDS POINT TO THE NAM BEING TOO DRY...WITH THE GFS A BIT WET. THE RUC13 LOOKS THE CLOSEST THROUGH TNGT...THUS WILL USE SCATTERED POPS FOR MOST AREAS...DECREASING ACROSS SE GA THIS EVENING...AND DIMINISHING ACROSS EXTREME NE FL OVERNIGHT. THE WAVE WILL SLOW DOWN AS IT APPROACHES CENTRAL FLORIDA THUS WILL KEEP CHANCE POPS INTO FRIDAY FOR SOUTHERN SECTIONS OF NE FL...WITH PRECIP ENDING THERE BY FRIDAY NIGHT. SKIES WILL BEGIN TO CLEAR ACROSS SE GA BY THE OVERNIGHT...WITH CLOUDS REMAINING ACROSS MOST OF NE FL THROUGH AT LEAST FRIDAY. SEASONABLY COOL TEMPERATURES WILL PREVAIL. .LONG TERM /SATURDAY THROUGH THURSDAY/...INDICATIONS ARE FRONTAL BOUNDARY OVER S CENTRAL FL AREA WILL WORK BACK NWD AS A WARM FRONT DURING LATTER HALF OF TH WEEKEND WITH A SUBSTANTIAL INCREASE IN DEEP LAYER MOISTURE OVER NE FL AND PORTIONS OF SE GA. CONSENSUS RH VALUES THROUGH 500 MB SHOW AT OR ABOVE 75% IN THE CWA. HAVE INCREASED OUR POPS TO CHANCE AND A SLIVER OF LIKELY ACROSS THE AREA DUE TO STRONG UPGLIDE ABOVE THE FRONTAL BOUNDARY. DEEPER MOISTURE AND FRONTAL BOUNDARY FINALLY PUSH E OF THE AREA SUNDAY NIGHT WITH CLEARING FROM NW TO SE BY MONDAY MORNING. THE HIGH PRESSURE WILL REMAIN OVER THE EASTERN US THROUGH MID WEEK WITH ONSHORE FLOW PROVIDING FOR COASTAL CLOUDS AND A FEW SHOWERS OVER THE COASTAL WATERS. A LOW IS FORECAST TO DEVELOP AND MOVE NORTHEAST THROUGH THE MIDWEST INTO THURSDAY... WITH TRAILING COLD FRONT AFFECTING FORECAST AREA...WITH PRECIPITATION CHANCES. MODEL DISCREPANCIES IN SOLUTION TUE-THU SUGGESTS NOT CHANGING THE FCST UNTIL BETTER CONSENSUS. && .AVIATION...MVFR TO VFR CIGS EXPECTED REST OF THE AFTN WITH OCNL IFR CIGS AND VSBY DUE TO LIGHT RAIN AND MIST. MVFR CIGS SEEM LIKELY IN THE EVENING WITH CONDS IMPROVING BY 12Z FRI TO VFR CIGS EXCEPT POSSIBLY MVFR CIGS AT GNV AROUND SUNRISE ON FRIDAY. && .MARINE...NLY WINDS HAVE KICKED UP TO 15-20 KT OVER THE MARINE ZONES WITH SCEC HEADLINE IN PLACE. MAY NEED TO KEEP HEADLINES GOING TONIGHT AND PERHAPS BRIEFLY INTO FRI MORNING BEFORE WINDS AND SEAS SUBSIDE. CONFIDENCE IN WINDS AND SEAS FCST GOES DOWN A BIT DURING THE WEEKEND DUE TO POSSIBLE LOW DEVELOPMENT OFFSHORE. IF NAM VERIFIES...HEADLINES MAY BE NECESSARY ESPECIALLY SAT NIGHT INTO SUN. MODELS ARE IN BETTER AGREEMENT OF INCREASED WINDS BY SUN NIGHT INTO MONDAY AS SFC HIGH PRES BUILDS N OF THE AREA AND FRONTAL BOUNDARY SAGS SWD OVER THE WRN ATLC INCREASING LOCAL PRESSURE GRADIENT. SCA HEADLINES MAY BE NECESSARY ON MONDAY THROUGH TUESDAY. RIP CURRENTS: RIP CURRENTS: LOW RISK OF RIP CURRENTS TODAY AND FRIDAY. && .FIRE WEATHER... MINIMUM RELATIVE HUMIDITIES WILL FALL TO 35-40 PERCENT ACROSS FAR INLAND AREAS FRIDAY...AND TO 30-35 PERCENT ACROSS INTERIOR SE GA SATURDAY. HOWEVER...WINDS WILL REMAIN LIGHT...SO STATEMENTS ARE NOT EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... AMG 35 60 36 60 / 30 0 0 30 SSI 43 59 45 61 / 30 10 10 40 JAX 41 62 41 63 / 30 10 10 50 SGJ 49 63 48 64 / 40 30 20 60 GNV 43 64 41 65 / 40 20 20 60 OCF 48 65 44 68 / 50 30 30 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ ALLEN/SHASHY/MCALLISTER
AFTER 42 YEARS...MY FINAL FORECAST DISCUSSION.
ALTHOUGH THESE WORDS WILL PASS WITH THE WIND...THE CAMARADERIE
SHARED WITH YOU...MY FELLOW WEATHER WATCHERS...WILL FOREVER BE CHERISHED. MAY THE SUN SOFTLY WARM YOU, THE RAIN REFRESH YOU, AND GOD BE WITH YOU...ALWAYS. LOU GIORDANO .OUTLOOK.../SATURDAY THROUGH MONDAY/... VFR UNTIL POSSIBLE RESTRICTIONS SATURDAY NIGHT AND SUNDAY AS A WEAK COLD FRONT MOVES ACROSS THE GREAT LAKES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
333 PM CST THU JAN 3 2013 .SHORT TERM...THROUGH 00Z SATURDAY. MORNING UPPER AIR ANALYSIS INDICATES A POSITIVELY TILTED LONGWAVE TOUGH EXTENDING FROM THE GREAT LAKES REGION INTO THE SOUTHWESTERN CONUS...WITH RIDGING OVER MUCH OF THE WESTERN CONUS AND QUASI-ZONAL FLOW ACROSS THE EAST. MID AND UPPER LEVEL JET ENERGY EXTENDS FROM THE SOUTHERN PLAINS...EAST/NORTHEAST INTO THE MID-ATLANTIC. TROPOSPHERIC FLOW OVER OUR AREA IS NOT OVERLY IMPRESSIVE AS A RESULT...MAXING OUT AT AROUND 50KTS NEAR 350MB PER 12Z RAP ANALYSIS SOUNDING DATA FOR KGRI. WATER VAPOR IMAGERY INDICATES INCREASED VALUES OF MID LEVEL MOISTURE OVER PORTIONS OF THE SOUTHEASTERN CONUS AHEAD OF THE MID LEVEL TROUGH AXIS...HOWEVER MID LEVEL MOISTURE FARTHER NORTHWEST...OVER THE CENTRAL PLAINS...REMAINS FAIRLY MEAGER. AT THE SURFACE A RIDGE OF HIGH PRESSURE IS NOTED EXTENDING FROM NORTH TEXAS...NORTHEAST INTO EASTERN KANSAS. AS A RESULT...THE LOW LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE WEST/SOUTHWEST BUT IS VERY LIGHT. GUIDANCE FROM THE NAM...OPERATIONAL GFS AND EC SUGGEST THE MID LEVEL TROUGH...CURRENTLY MOVING OVER CENTRAL PORTIONS OF THE CONUS...WILL DEEPEN INTO A CLOSED LOW OVER THE SOUTHERN PLAINS TONIGHT INTO TOMORROW. DESPITE THIS DEEPENING MID LEVEL LOW...ANY OMEGA IN ASSOCIATION WITH THIS SYSTEM IS EXPECTED TO REMAIN OVER THE SOUTHERN PLAINS...WITH DRY CONDITIONS EXPECTED OVER OUR AREA TONIGHT AND TOMORROW. CLEAR SKIES AND 2-6 INCHES OF SNOWPACK ACROSS OUR AREA SHOULD PROMOTE STRONG RADIATIONAL COOLING TONIGHT...WITH 25-30 DEGREE DROP OFFS NOT OUT OF THE QUESTION FOR MANY LOCATIONS ACROSS THE CWA. OVERNIGHT LOWS IN THE SINGLE DIGITS ABOVE ZERO ARE FORECAST FOR MOST LOCATIONS AS ACROSS THE AREA AS A RESULT. AN INCREASING SOUTHWESTERLY LOW LEVEL WIND FIELD SHOULD PROMOTE SUBTLE LOW LEVEL WARM AIR ADVECTION DURING THE DAY FRIDAY...WITH 30-35 DEGREE RISES CURRENTLY FORECAST. THIS PRESENTS FRIDAY AFTERNOON HIGHS GENERALLY IN THE 30S. FINALLY...WITH STRONG RADIATIONAL COOLING EXPECTED TONIGHT AND LOW LEVEL DEWPOINTS LINGERING IN THE SINGLE DIGITS ABOVE ZERO...NEAR- SURFACE DEWPOINT DEPRESSIONS NEAR ZERO WILL LIKELY BE REALIZED. ALTHOUGH DRIER LOW LEVEL AIR WILL BE ADVECTING IN FROM EASTERN COLORADO AND WESTERN KANSAS...IT APPEARS THE STRONG RADIATIONAL COOLING...WORKING IN CONCERT WITH A LIGHT LOW LEVEL WIND FIELD...COULD BE CONDUCIVE FOR PATCHY FOG DEVELOPMENT. WENT AHEAD WITH SUCH WORDING IN THE FORECAST...PRIMARILY ACROSS OUR SOUTHEASTERN CWA WHICH IS WHERE LOW LEVEL MOISTURE IS EXPECTED TO BE THE HIGHEST AND THE LOW LEVEL WIND FIELD IS EXPECTED TO BE THE WEAKEST. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. MAIN FORECAST CONCERNS WILL BE CHANCE FOR PRECIPITATION WEDNESDAY AND WEDNESDAY NIGHT AND TEMPERATURES THROUGH THE PERIOD. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA FRIDAY NIGHT. DESPITE THE COLD FRONT THE TEMPERATURES FRIDAY NIGHT WILL BE A FEW DEGREES WARMER THAN THURSDAY NIGHT. THERE IS WARMER AIR ACROSS THE REGION AND THE COLDER AIR DOES NOT MOVE INTO THE REGION UNTIL ON SATURDAY. EVEN THIS IS NOT MUCH COLDER AND TEMPERATURES WILL BE ABOUT THE SAME AS ON FRIDAY. IN ADDITION THERE IS A WEAK UPPER LEVEL WAVE THAT MOVES INTO THE AREA ON SATURDAY AND BRINGS A FEW CLOUDS TO THE REGION. SATURDAY NIGHT INTO SUNDAY AN UPPER LEVEL RIDGE MOVES INTO THE AREA AND WARM ADVECTION STARTS UP ACROSS THE AREA. WINDS TURN TO THE SOUTH/SOUTHWEST AND INCREASE. ALL OF THIS SHOULD SHOW UP IN TEMPERATURES WARMING A BIT ON SUNDAY. MODELS START TO DIVERGE GREATLY NEXT WEEK. THE GFS AND CANADIAN BOTH OPEN THE WAVE SOME AND MOVE IT THROUGH MONDAY AND TUESDAY. THE ECMWF CONTINUES TO KEEP A STRONG UPPER LEVEL LOW THAT MOVES FROM THE FOUR CORNERS REGION TO THE SOUTHERN PLAINS. THE ECMWF HAS MAINTAINED SOME RUN TO RUN CONSISTENCY WHILE THE OTHERS HAVE MADE SOME CHANGES IN THE LAST RUN. FOR NOW WILL CONTINUE TO HAVE THE PRECIPITATION ON WEDNESDAY AND WEDNESDAY NIGHT WHICH IS MORE SIMILAR TO THE ECMWF. THE NEXT QUESTION WILL BE PRECIPITATION TYPE. IN ADDITION TO THE TIMING CHANGE THAT THE GFS HAS...TEMPERATURES ARE MUCH COLDER...WHICH IS DIFFERENT THAN PREVIOUS RUNS. HAVE CONTINUED THE WARMER TEMPERATURES AND THEREFORE WILL KEEP RAIN IN THE FORECAST FOR WEDNESDAY. AS THE TEMPERATURES COOL OFF WEDNESDAY NIGHT THERE WILL BE SOME SNOW MIXED INTO THE RAIN. BY THURSDAY...THE UPPER LEVEL LOW HAS MOVED OFF TO THE EAST AND THEREFORE EXPECT DRY CONDITIONS. && .PREV DISCUSSION... /ISSUED 1115 AM CST THU JAN 3 2013/ AVIATION...18Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS. STRATUS WILL REMAIN TO THE SOUTH AND EAST OF THE TERMINAL THUS PROVIDING LITTLE IN THE WAY OF CLOUD COVER AT KGRI. THE SURFACE WIND WILL REMAIN FROM THE NORTHWEST AT AROUND 10KTS FOR A FEW MORE HOURS BEFORE BECOMING LIGHT AND VARIABLE THROUGH THE REMAINDER OF THE TAF PERIOD. VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS BUFFALO NY
420 PM EST THU JAN 3 2013 .SYNOPSIS... LOW PRESSURE MOVING ACROSS SOUTHERN QUEBEC WILL BRING SNOW SHOWERS TO THE AREA THIS EVENING...BEFORE STEADIER LAKE EFFECT SNOW SETS UP EAST OF LAKE ONTARIO TONIGHT AND FRIDAY. AS THE LOW MOVES TO THE EAST ON FRIDAY...RATHER WINDY CONDITIONS WILL DEVELOP ACROSS THE ENTIRE AREA. && .NEAR TERM /THROUGH FRIDAY/... MAINLY LIGHT SNOW IS SPREADING EAST ACROSS THE AREA THIS AFTERNOON AS WARM AIR ADVECTION CONTINUES AHEAD OF THE SURFACE LOW THAT IS CURRENTLY TRACKING JUST SOUTH OF JAMES BAY. THE STEADIER SNOW IS FALLING ALONG THE RETREATING ARCTIC FRONT WHICH IS PUSHING THROUGH THE NORTHERN FINGER LAKES AND NORTH COUNTRY. WE ARE KEEPING AN EYE ON THE AREA OF SNOW THAT IS FORMING WEST OF LAKE ONTARIO. THIS MARKS THE LEADING EDGE OF THE COLD FRONT/CONVERGENT BOUNDARY THAT TRAILS THE SURFACE LOW. AS THIS FRONT REACHES LAKE ERIE AROUND 21Z...EXPECT THE NARROW BAND OF SNOW TO INTENSIFY A BIT AS IT PICKS UP MORE MOISTURE FROM THE LAKE. ADDITIONAL LIFT WILL BE GENERATED BY THE SHORT WAVE THAT IS APPROACHING THE LAKE. THE HRRR PICKS UP ON THIS TREND AND SUGGESTS THAT A BURST OF SNOW MAY IMPACT THE AREA STRETCHING FROM METRO BUFFALO TO BATAVIA BETWEEN 21Z AND 23Z. THIS AREA COULD PICK UP A QUICK 1 TO 2 INCHES OF SNOW...WHICH COMBINED WITH GUSTY SOUTHWEST WINDS COULD MAKE FOR A CHALLENGING RUSH HOUR COMMUTE. THE SNOW IS EXPECTED TO DROP SOUTHEAST ACROSS THE SOUTHERN TIER AND UPPER GENESEE VALLEY LATER IN THE EVENING. EXPECT A SIMILAR TREND TO DEVELOP EAST OF LAKE ONTARIO FROM ABOUT 23Z THROUGH 02Z. AFTER THE COLD FRONT CLEARS THE AREA EARLY TONIGHT...THE BOUNDARY LAYER WINDS WILL SHIFT TO THE WEST AND ALLOW THE REMAINING SNOWBANDS TO SETTLE TO THE SOUTH. ACROSS THE SOUTHERN...1 TO 3 INCHES OF SNOW MAY ACCUMULATE BEFORE THE INVERSION LOWER SHARPLY AFTER 06Z. MODERATING TEMPERATURES ALOFT WILL ALSO REDUCE THE LAKE INSTABILITY. HOWEVER...THE BUFKIT PROFILES STILL SHOW PLENTY OF MOISTURE TRAPPED BELOW THE LOWERING SUBSIDENCE INVERSION. THIS COMBINED WITH THE WESTERLY UPSLOPE FLOW COULD RESULT INCH OF SNOW. OFF LAKE ONTARIO...STILL EXPECT A MORE SIGNIFICANT EVENT...WITH A LONGER FETCH AND UPSLOPE ENHANCEMENT ON THE TUG HILL. THE LAKE INDUCED INSTABILITY WILL ALSO BE GREATER DUE TO THE PRESENCE OF COLDER AIR ALOFT. THIS ALL POINTS TO SOME DECENT LAKE EFFECT SNOW EAST OF LAKE ONTARIO TONIGHT...WITH THE BEST FOCUS ON THE TUG HILL. AS A RESULT A LAKE EFFECT SNOW ADVISORY REMAINS IN EFFECT FOR TONIGHT THROUGH FRIDAY FOR OUR THREE EASTERN LAKE ONTARIO COUNTIES. OUTSIDE OF THE NORMAL LAKE EFFECT AREAS...EXPECT A FEW SNOW SHOWERS WITH LITTLE OR NO ACCUMULATION. AS THE SURFACE LOW PUSHES EAST ACROSS QUEBEC ON LATE TONIGHT AND FRIDAY...A STRONG WESTERLY FLOW WILL SET UP ACROSS THE AREA. IN TERMS OF THE POTENTIAL FOR SNOW...THE BEST CHANCE WILL BE EAST OF LAKE ONTARIO WHERE TEMPERATURES ALOFT...MOISTURE AND SNOW GROWTH WILL BE STILL BE FAVORABLE FOR LAKE EFFECT SNOW. THE MODELS SUGGEST THAT THE SNOW MAY SHIFT A LITTLE TO THE NORTH AS THE BOUNDARY LAYER WINDS BACK A LITTLE MORE TO THE WEST SOUTHWEST. EAST OF LAKE ERIE...THE LAKE EFFECT PARAMETERS WILL NOT NEARLY BE AS FAVORABLE. THERE WILL STILL BE PLENTY OF MOISTURE TRAPPED BELOW THE SUBSIDENCE INVERSION...BUT THERE WILL BE NO ICE CRYSTALS WITHIN THE SHALLOW MOIST LAYER. AS A RESULT...IT LOOKS LIKE PCPN WILL BE A MIX OF LIGHT SNOW AND FREEZING DRIZZLE. THIS LIGHT MIX OF PCPN MAY LIFT SHIFT NORTH TOWARD BUFFALO AS THE BOUNDARY LAYER WINDS SHIFT TO THE SOUTHWEST. RIGHT NOW...IT LOOKS LIKE THERE WILL LITTLE ACCUMULATION OF SNOW. STRONG WINDS WILL BE THE MAIN ISSUE FOR MOST OF THE CWA ON FRIDAY. THE NAM AND GFS SHOW A 40 TO 50 KNOT LOW LEVEL JET TRACKING ACROSS NEW YORK STATE. MOMENTUM TRANSFER SCHMOES SUGGESTS THAT THE STRONGER WINDS WILL MIX DOWN TO THE SURFACE. AS A RESULT...MOST AREAS CLOSE TO THE LAKE SHORES WILL LIKELY SEE ADVISORY WIND GUSTS. THEREFORE A WIND ADVISORY HAS BEEN ISSUED FOR THE COUNTIES OUTLINED BELOW. THE STRONG WINDS COMBINED WITH ANY FALLING SNOW WILL RESULT IN CONSIDERABLE BLOWING AND DRIFTING OF SNOW...ESPECIALLY EAST OF LAKE ONTARIO WHERE TRAVEL WILL BECOME VERY DIFFICULT. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... SNOW SHOWERS WILL BE LINGERING ACROSS THE NORTH COUNTRY FRIDAY NIGHT AS WELL ALIGNED WEST NORTHWESTERLY FLOW WILL CONTINUE ACROSS LAKE ONTARIO. INVERSION LEVELS WILL BE LOWERING OVERNIGHT ACROSS THE REGION HOWEVER AS A PASSING SHORTWAVE TROUGH CLEARS THE AREA AND UPPER LEVEL RIDGING ALONG WITH DRIER AIR NOSES NORTHWARDS INTO THE LOWER GREAT LAKES. ACROSS FAR WESTERN NEW YORK...INVERSION HEIGHTS WILL BE EVEN LOWER WITH DRY AIR IN THE DENDRITIC GROWTH ZONE ALOFT. HOWEVER...MODEL SOUNDINGS INDICATE THAT THERE MAY STILL BE A FAIR AMOUNT OF MOISTURE TRAPPED UNDERNEATH THE INVERSION IN THE LOWEST LEVELS OF THE ATMOSPHERE AND THIS COMBINED WITH CONTINUED UPSLOPE WESTERLY FLOW OFF THE LAKE MAY CREATE A POTENTIAL FOR AREAS OF FREEZING DRIZZLE ACROSS WESTERN NEW YORK FRIDAY NIGHT. SATURDAY SHOULD BE A QUIET DAY ACROSS THE REGION AS UPPER LEVEL RIDGING MOVES OVER THE REGION WITH JUST A SLIGHT CHANCE OF FLURRIES OR PATCHY FREEZING DRIZZLE LINGERING ACROSS THE NIAGARA FRONTIER AND SOUTH OF LAKE ONTARIO DUE TO WEAK SURFACE CONVERGENCE. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY BELOW NORMAL WITH HIGHS IN THE UPPER 20S. SATURDAY NIGHT AND SUNDAY...LOOK FOR SNOW TO DEVELOP ACROSS THE FORECAST AREA AS YET ANOTHER HIGH AMPLITUDE UPPER LEVEL TROUGH WITH A WEAK SURFACE LOW AT THE SURFACE CROSSES THE GREAT LAKES. WHILE SYNOPTIC MOISTURE WILL NOT BE PARTICULARLY DEEP...A WIDESPREAD 2 TO 4 INCHES MAY BE POSSIBLE ACROSS THE REGION. BROAD UPPER LEVEL RIDGING WILL BUILD ACROSS THE REGION IN THE WAKE OF THIS LOW SUNDAY NIGHT...BRINGING AN END TO THE SNOWFALL AND USHERING IN A WARM-UP SET TO TAKE PLACE DURING THE EARLY PART OF NEXT WEEK... && .LONG TERM /MONDAY THROUGH THURSDAY/... THE FORECAST FOR THE COMING WEEK ACROSS OUR REGION HINGES ON THE FATE OF AN STRONG UPPER LEVEL TROUGH THAT WILL BE DIGGING INTO THE WESTERN U.S. OVER THE WEEKEND. SUBSTANTIAL DIFFERENCES EXIST BETWEEN THE GLOBAL MODELS WITH THE GFS DIGGING THE TROUGH ACROSS THE SOUTHWEST AT THE BEGINNING OF THE WEEK AND THEN LIFTING THE TROUGH ACROSS THE MISSISSIPPI VALLEY DURING THE MIDDLE OF THE WEEK...TRACKING A LARGE STORM SYSTEM ACROSS THE GREAT LAKES. ON THE OTHER HAND...THE ECMWF CUTS OFF THE BASE OF THE TROUGH ACROSS THE DESERT SOUTHWEST LEADING TO A CUTOFF LOW THAT LINGERS THERE THROUGH THE FIRST HALF OF THE WEEK AND THEN GRADUALLY LIFTING ACROSS THE PLAINS DURING THE MIDDLE OF THE WEEK. THIS PROGNOSIS KEEPS ZONAL FLOW AND/OR UPPER LEVEL RIDGING IN PLACE OVER OUR REGION AT LEAST INTO THE MIDDLE OF THE WEEK RESULTING IN WHAT SHOULD BE A DRY AND INCREASINGLY MILD FORECAST. HISTORICALLY...THE FORMATION OF THE CUTOFF LOW OVER THE SOUTHWEST IS QUITE COMMON FOR THIS TIME OF YEAR AND MODELS TYPICALLY ARE TOO FAST IN PUSHING THIS FEATURE OUT OF THE SOUTHWEST. THEREFORE THIS FORECAST STRONGLY FAVORS THE ECMWF SOLUTION. AS SUCH...EXPECT THE FIRST HALF OF THE UPCOMING WEEK TO BE DRY WITH TEMPERATURES MODERATING FROM THE LOW 30S MONDAY TO AROUND 40 BY WEDNESDAY. && .AVIATION /22Z THURSDAY THROUGH TUESDAY/... A COLD FRONT WILL PUSH THROUGH THE AREA EARLY TONIGHT. A NARROW BAND OF SNOW WILL PRECEDE THE FRONT AS IT CROSSES EACH LAKE. THIS COULD RESULT IN A BRIEF OF IFR CONDITIONS WITH PASSING FRONT. BEHIND THE FRONT...A WESTERLY FLOW OF COLD AIR WILL GENERATE STEADIER LAKE EFFECT SNOW EAST OF LAKE ONTARIO WHERE MORE WIDESPREAD IFR CONDITIONS WILL PREVAIL...ESPECIALLY LATER TONIGHT AS THE WINDS PICK UP. OTHERWISE...EXPECT MVFR CONDITIONS TO BE THE RULE FOR MOST OF THE NIGHT THROUGH FRIDAY...ALTHOUGH CONDITIONS WILL LIKELY DIP TO IFR AT TIMES DUE TO THE WESTERLY UPSLOPE FLOW. WE MAY ALSO SEE FREEZING DRIZZLE MIXING IN WITH LIGHT SNOW AT TIMES OUTSIDE OF THE MAIN LAKE EFFECT AREAS. STRONG WEST TO SOUTHWEST WINDS WILL ALSO IMPACT ALL TAF SITES LATE TONIGHT AND FRIDAY AS A POTENT LOW LEVEL JET TRACKS EAST ACROSS NEW YORK STATE. THE LATEST GUIDANCE SUGGESTS THAT SOME OF THE STRONGER WINDS WILL MIX DOWN TO THE SURFACE...ESPECIALLY JUST DOWNWIND OF THE LAKES WHERE GUSTS UP TO 40 KNOTS ARE POSSIBLE. OUTLOOK... SATURDAY...MAINLY VFR. SUNDAY...MVFR/IFR WITH CHANCE OF SNOW SHOWERS. MONDAY AND TUESDAY...VFR. && .MARINE... THE MAIN CONCERN FOR LATE TONIGHT AND FRIDAY WILL BE THE LIKELIHOOD OF GALE FORCE WINDS AS A DEEPENING AREA OF LOW PRESSURE MOVES EAST ACROSS SOUTHERN QUEBEC. A POTENT LOW LEVEL JET THAT WILL BE TRACKING EAST ACROSS NEW YORK STATE WILL ALLOW WINDS TO GUST UP TO 45 KNOTS AT TIMES. WINDS AND WAVES WILL SUBSIDE GRADUALLY FRIDAY NIGHT AND SATURDAY AS HIGH PRESSURE BUILDS EAST ACROSS NEW YORK STATE. && .CLIMATE... OUR THREE CLIMATE SITES HAVE EITHER SET...OR TIED THEIR WARMEST YEAR ON RECORD. BOTH BUFFALO AND WATERTOWN HAVE FINISHED A FULL DEGREE OR MORE WARMER THAN THEIR PREVIOUS YEARS ON RECORD. ONE NOTE FOR BUFFALO IS TEMPERATURE RECORDS WERE RECORDED DOWNTOWN AND CLOSER TO LAKE ERIE UNTIL THE SUMMER OF 1943. ROCHESTER TIED FOR THEIR WARMEST YEAR ON RECORD WITH THE YEAR 1931...WHICH WAS A PARTICULARLY WARM YEAR FOR THE EASTERN GREAT LAKES REGION. TEMPERATURE RECORDS FOR BOTH BUFFALO AND ROCHESTER GO BACK TO 1871. WHILE WATERTOWN HAS A SHORTER PERIOD OF RECORD WITH ANNUAL TEMPERATURES GOING BACK TO ONLY 1950. BUFFALO 1 2012 52.1 2 1998 50.9 3 2006 50.6 1991 50.6 1921 50.6 ROCHESTER 1 2012 51.8 (TIE) 1931 51.8 3 2006 51.5 4 1921 51.4 5 1998 50.7 WATERTOWN 1 2012 49.2 2 1953 48.1 3 1998 48.0 4 2006 47.4 5 1952 47.2 && .BUF WATCHES/WARNINGS/ADVISORIES... NY...WIND ADVISORY FROM 6 AM TO 6 PM EST FRIDAY FOR NYZ001>003- 010>012-019-020-085. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST FRIDAY FOR NYZ006>008. WIND ADVISORY FROM 10 AM TO 6 PM EST FRIDAY FOR NYZ004>008. MARINE...GALE WARNING FROM 7 AM TO 7 PM EST FRIDAY FOR LEZ020-040-041. SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR LEZ040-041. GALE WARNING FROM 7 AM TO 7 PM EST FRIDAY FOR LOZ030- 043>045-063>065. SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR LOZ042. SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR LOZ043>045. GALE WARNING FROM 7 AM TO 4 PM EST FRIDAY FOR LOZ042-062. && $$ SYNOPSIS...TJP NEAR TERM...TJP SHORT TERM...WOOD LONG TERM...WOOD AVIATION...TJP MARINE...TJP CLIMATE...THOMAS
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1011 AM CST THU JAN 3 2013 .DISCUSSION.../ISSUED AT 1011 AM CST/ JUST ENOUGH ISENTROPIC LIFT IN THE 925-875 HPA LAYER THIS MORNING TO COUPLE WITH VERY DENDRITIC TEMPERATURE RANGE TO KICK START SHALLOW PRECIPITATION PROCESSES...AND BRING A LIGHT DUSTING TO SNOW TO THE I29 CORRIDOR AND JUST EAST THROUGH MID MORNING. BAND IS ABOUT 40 NM WIDE NEAR THE LEADING EDGE OF THE ADVANCING LOW CLOUDS /WITH DEPTH NO MORE THAN 3000 FT PER MORNING ABR RAOB. FOR NOW...PROBABLY WILL END UP WITH A TENTH OR TWO OF SNOWFALL AS BAND MOVES EAST...BUT LIKELY TO NOT GET MEASURABLE LIQUID WITH THE VERY DENDRITIC SNOWFALL. RAP IS REALLY THE ONLY RELIABLE SHORT RANGE GUIDANCE ON LOWER CEILINGS...ALTHOUGH 12Z NAM LOOKS AS IF IT IS TRYING TO CATCH ON... AND BOTH ARE FAIRLY PESSIMISTIC TO GET MUCH CLEARING TOWARD I29 BY 00Z. DID INCREASE CLOUDS AND ADD MENTION OF FLURRIES A COUPLE HOURS AGO...BUT MAY END UP NEEDING TO DELAY CLEARING SOMEWHAT MORE. CLOUDS WILL IMPACT POTENTIAL WARMING WEST...AND WILL LIKELY HELP THINGS ALONG ACROSS THE COLDER EAST. /CHAPMAN && .AVIATION.../FOR THE 18Z TAF ISSUANCE/ MASS OF MVFR CEILINGS WILL CONTINUE TO WORK EASTWARD THROUGH THE DAY. LEADING 30-40NM FEATURING LIGHT SNOW AND FLURRIES...WITH SOME VISIBILITIES BRIEFLY INTO THE IFR RANGE...BUT MOSTLY MVFR. SHOULD BECOME VFR AGAIN AFTER 00Z TONIGHT FOR ALL TAF SITES. MVFR CEILINGS WEST OF I29 WILL GRADUALLY BECOME VFR FROM THE WEST DURING THE AFTERNOON HOURS. /CHAPMAN && .PREV DISCUSSION.../ISSUED AT 300 AM CST/ TEMPERATURE AND CLOUD FORECAST A BIT TRICKY FOR TODAY. CURRENTLY SEEING AN AREA OF CLEARING ACROSS THE EASTERN PORTION OF OUR CWA...WITH A LARGE AREA OF STRATUS LOCATED OVER THE CENTRAL AND WESTERN DAKOTAS. AS LOW LEVEL WINDS TURN MORE WESTERLY THINKING IS THAT THIS STRATUS TO THE WEST WILL MOVE ACROSS OUR CWA...ONLY SLOWLY DISSIPATING AS IT MOVES EAST. RAP SEEMS TO BE HANDLING THIS THE BEST AND THUS FOLLOWED CLOSER TO IT FOR CLOUD COVER TODAY. SLOWED DOWN THE EXIT OF THE CLOUDS...WITH CLEARING OUT WEST EXPECTED BY LATE MORNING...THE INTERSTATE 29 CORRIDOR EARLY TO MID AFTERNOON...AND NOT EXITING OUR EAST UNTIL LATE AFTERNOON OR EVENING. ALSO RAISED HIGH TEMPERATURES TODAY BY A FEW DEGREES. TEMPERATURES UNDER THE CURRENT STRATUS IN THE UPPER TEENS...AND AS IT MOVES BACK IN...THINKING MOST LOCATIONS GET AT LEAST TO THESE TEMPERATURES. WARMEST READINGS WILL BE WEST OF THE JAMES RIVER...WHERE AFTERNOON SUN SHOULD ALLOW HIGHS IN THE MID 20S. SHOULD SEE CLEAR SKIES BY TONIGHT. LOWS WILL BE TRICKY...AS A DECENT LOW LEVEL JET MOVES ACROSS OUR EASTERN AREAS. OVERALL THINKING SINGLE DIGITS AND TEENS FOR LOWS. THE WARMEST READINGS WILL BE NEAR AND DOWNWIND OF THE BUFFALO RIDGE...WHERE SUSTAINED SOUTHWESTERLY WINDS NEAR 20 KTS WILL KEEP THINGS MIXED. POTENTIAL EXISTS FOR LOWS NEAR ZERO IN THE INTERSTATE 29 CORRIDOR IF WE CAN DECOUPLE. DID TREND TOWARDS THE COOLER SIDE OF GUIDANCE HERE GIVEN SNOWCOVER AND CLEAR SKIES...BUT IF THE WINDS STAY UP JUST ENOUGH THEN CURRENT LOWS WILL LIKELY BE TOO COLD. WILL SEE A BIT OF RIDGING AND WARMING TEMPERATURES ALOFT ON FRIDAY. LOWERED HIGHS A BIT...GIVEN SNOW COVER AND EXPECTED WEAK MIXING PREVENTING US FROM REALIZING MUCH OF THE WARM AIR ALOFT. ALTHOUGH THE NAM SEEMS TOO COLD...AND THINKING WE STILL SEE UPPER 20S TO LOW 30S MOST SPOTS...WITH LOW 40S POSSIBLE IN OUR FAR SOUTHWEST. UPPER LEVEL TROUGH AND ANOTHER COLD SHOT MOVES IN ON SATURDAY. LOOKS LIKE WE SHOULD SEE SOME MORE STRATUS ON SATURDAY WITH THIS FEATURE. COULD SEE SOME FLURRIES AS WELL...BUT NOT EXPECTING ANYTHING MORE THAN THAT. MODELS DISAGREE SOME ON TIMING AND MAGNITUDE OF THE COLD SHOT...BUT HIGHS WILL LIKELY BE IN THE 20S MOST SPOTS. WE THEN SEE A WARMING TREND SUNDAY INTO THE MIDDLE OF NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS IN. SUNDAY WILL STILL BE COOL ON THE BACKSIDE OF THE TROUGH...WITH 20S EAST AND 30S SOUTHWEST. HOWEVER BY MONDAY INTO WEDNESDAY...EXPECT WARMING TEMPERATURES ALOFT AND FLOW FAVORABLE FOR DECENT MIXING. SO DESPITE SNOWCOVER...EXPECTING HIGHS TO RISE ABOVE FREEZING IN MOST LOCATIONS EACH DAY UNDER PARTLY TO MOSTLY SUNNY SKIES. MODELS IN GOOD AGREEMENT THAT A CUTOFF LOW OVER SOUTHERN CALIFORNIA ON MONDAY WILL PUSH EAST INTO THE SOUTHERN PLAINS BY MIDWEEK. AS IT IS PICKED UP BY THE UPPER FLOW AND TURNS NORTHEAST DISAGREEMENT ENTERS ON HOW FAR NORTHWEST IT GETS. THERE IS THUS THE POTENTIAL FOR SOME PRECIPITATION...PROBABLY WEDNESDAY NIGHT OR THURSDAY WITH THIS SYSTEM...SO WILL HAVE TO MONITOR TRENDS. AS IT LOOKS NOW...TEMPERATURE PROFILE MAY VERY WELL BE TOO WARM FOR SNOW...FAVORING A RAIN OR MIXED PRECIP THREAT IF ANYTHING. FLOW THEN TURNS FAVORABLE FOR MORE COLD AIR TO END NEXT WEEK. /CHENARD && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
233 PM CST THU JAN 3 2013 .SHORT TERM... 233 PM CST THU JAN 3 2013 MAIN CONCERN IN THE SHORT TERM IS THE CLOUD TRENDS TONIGHT...AND THEN ATTENTION SHIFTS TO CLOUDS AND FLURRIES/DRIZZLE ON SATURDAY. 19Z SURFACE ANALYSIS SHOWS RIDGE OF HIGH PRESSURE RUNNING FROM KS UP INTO MN...AS LOW PRESSURE EXITS ACROSS THE GREAT LAKES REGION. SATELLITE IMAGERY SHOWS EXTENSIVE LOW CLOUDS ACROSS MUCH OF THE AREA...BUT CLOUD IS DISSIPATING ON THE WESTERN EDGE. BACK EDGE OF THE CLOUD BAND HAD REACHED THE MISSISSIPPI RIVER...WITH ANOTHER DIMINISHING PATCH OF CLOUDS ALONG THE MN/DAKOTAS BORDER. WHERE THERE WERE CLOUDS...THERE WERE ALSO FLURRIES. FIRST ISSUE IS THE CLOUD TRENDS TONIGHT. WITH RIDGING MOVING IN...ANTICIPATE THE CLOUDS WILL CONTINUE TO DISSIPATE TONIGHT... WHICH IS IN LINE WITH PREVIOUS FORECAST THINKING. WITH LITTLE CLOUD AND DIMINISHING WINDS UNDER THE RIDGE...THINK IT IS PRUDENT TO CONTINUE WITH TEMPERATURES AT OR BELOW GUIDANCE. WINDS WILL COME AROUND TO THE SOUTH LATE IN THE NIGHT...BUT NOT SURE IT WILL OCCUR FAST ENOUGH TO LIMIT A TEMP PLUNGE...ESPECIALLY OVER THE FAVORED COOL SPOTS IN WESTERN WI. GOOD LOW LEVEL WARM ADVECTION CONTINUES ACROSS THE AREA FOR FRIDAY. WITH DRY AIR IN PLACE AND AMPLE SUNSHINE...ALONG WITH A WARM SOUTHWEST BREEZE...HIGHS SHOULD WARM WELL INTO THE 20S AND LOWER 30S. BUT THE DRY AIR WILL ALSO AID RADIATIONAL COOLING FRIDAY NIGHT...SO EXPECT ANOTHER CHILLY NIGHT. NEXT TAG-TEAM OF DISTURBANCES LOOKS TO PROVIDE A CHANCE FOR SOME LIGHT PRECIPITATION STARTING LATE SATURDAY. ONE TROUGH WILL MOVE THROUGH THE SOUTHERN PLAINS AND WILL TAKE A TURN UP TOWARD CHICAGO BY MID-DAY ON SATURDAY. MEANWHILE...A SECOND SHORT WAVE TROUGH IN THE NORTHERN STREAM WILL DROP FROM THE DAKOTAS INTO MN. EACH WILL PROVIDE SOME LIFT AND SUPPORT FOR PRECIPITATION...HOWEVER DEEPER MOISTURE WILL BE LACKING. PERUSAL OF VARIOUS MODEL SOUNDINGS VIA BUFKIT SHOWS THE MOISTURE TO BE VERY SHALLOW...AND THE TEMPERATURE PROFILE SUGGESTS MUCH OF THE LOWER COLUMN WHERE SATURATION OCCURS WILL BE RELATIVELY WARM...NEAR OR ABOVE -10C. THERE IS SOME INDICATION ON A FEW MODELS THAT SOME SEEING OF THIS LAYER COULD OCCUR FROM ABOVE. EITHER WAY...LIFT IS LIMITED AND AMOUNTS WILL BE VERY LIGHT. DISCUSSION WITH SURROUNDING OFFICES LED TO REINTRODUCING FLURRIES TO THE FORECAST...BUT OPTED NOT TO ADD THE DRIZZLE WORDING AT THIS TIME. .LONG TERM... 233 PM CST THU JAN 3 2013 MEDIUM RANGE PERIOD CONTINUES TO BE MUDDLED AS MODEL SOLUTIONS ARE IN TWO DISTINCT CAMPS REGARDING THE ENERGY DIGGING INTO THE WEST COAST IN BOTH THE SOUTHERN AND NORTHERN STREAMS. IF ANYTHING...THE 12Z MODEL SOLUTIONS HAVE ADDED MORE UNCERTAINTY. ONE CLUSTER OF MODELS...INCLUDING THE GFS/GEM/UKMET SUPPORT A STRONG BUT PROGRESSIVE LONG WAVE TROUGH MOVING ACROSS THE CONUS EARLY NEXT WEEK...WHILE THE NAM AND VARIOUS ENSEMBLES SUPPORT THE ECMWF WITH A CLOSED CIRCULATION DEVELOPING OVER NORTHWEST MEXICO AND MOVING SLOWLY INTO THE CENTRAL PLAINS BY THURSDAY. ECMWF HAS A BETTER LONG-RANGE TRACK RECORD SO IT IS HARD TO DISCOUNT ITS SOLUTION. HOWEVER... WITH THE AMOUNT OF ENERGY SEEN MOVING INTO THE TROUGH OVER THE WEEKEND...IT MAY BE HARD FOR THE SYSTEM TO ACTUALLY SEPARATE ITSELF FROM THE FLOW AS DEPICTED. FOR NOW HAVE CONTINUED ALONG THE LINE OF THE PREVIOUS FORECAST...WHICH LINES UP CLOSER TO THE ECMWF. THIS SYSTEM WILL HAVE TO BE MONITORED...BECAUSE DEPENDING ON THE TRACK AND TEMPERATURE PROFILES...SOMEBODY IN OUR REGION WILL SEE SIGNIFICANT PRECIPITATION...AND IT COULD BE SNOW OR EVEN RAIN. CONFIDENCE IN THIS PERIOD OF THE FORECAST IS BELOW AVERAGE. EITHER WAY...IT APPEARS THE OVERALL FLOW REGIME WILL BECOME MORE WESTERLY AND THEN SOUTHWESTERLY...WHICH SHOULD PROVIDE A WARM UP. TEMPERATURES LOOK TO BE ABOVE NORMAL NEXT WEEK. && .AVIATION...THROUGH 18Z FRIDAY 1113 AM CST THU JAN 3 2013 WEAK SURFACE RIDGE CENTERED OVER NEBRASKA WITH THE RIDGE AXIS NORTH INTO MINNESOTA. MVFR CLOUDS EAST OF THE RIDGE AXIS ARE MOVING SLOWLY TO THE SOUTHEAST AND ARE EXPECTED TO CLEAR BOTH TAF SITES LATE THIS AFTERNOON. WILL SEE THE FLURRIES CONTINUE UNTIL THE CLOUDS CLEAR THE AREA AS THE 03.15Z RAP SOUNDINGS SHOW SOME WEAK OMEGA THROUGH THE SATURATED LAYER. ONCE THE CLOUDS CLEAR OUT...VFR CONDITIONS WITH CLEAR SKIES EXPECTED FOR THE REMAINDER OF THE PERIOD. THE CENTER OF THE SURFACE RIDGE WILL MOVE INTO KANSAS AND OKLAHOMA TONIGHT AND ONCE THE RIDGE AXIS MOVES THROUGH...THE AREA WILL BE IN THE PRESSURE GRADIENT FROM A SYSTEM PASSING ACROSS SOUTHERN CANADA. THIS WILL BE ENOUGH TO KEEP THE WINDS UP AROUND 10 KNOTS OUT OF THE SOUTHWEST. && .ARX WATCHES/WARNINGS/ADVISORIES... 233 PM CST THU JAN 3 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...MW LONG TERM...MW AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1113 AM CST THU JAN 3 2013 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT 341 AM CST THU JAN 3 2013 MAIN FORECAST CONCERNS THIS PACKAGE...SMALL PRECIP/FLURRY/FZDZ CHANCES THIS MORNING AND AGAIN SAT NIGHT...TEMPERATURES THRU THE PERIOD. 06Z DATA ANALYSIS HAD A BROAD AREA OF LOW PRESSURE ACROSS THE REGION...CENTERED OVER LK SUPERIOR. LEAD TROUGH/WIND SHIFT AROUND THIS LOW WAS OVER EASTERN WI TO EASTERN IA. SECOND TROUGH/FRONT WAS OVER NORTHWEST WI TO NEAR OMAHA. LEAD BAND OF VERY LIGHT SNOW WITH THE FIRST TROUGH WAS EXITING THE FCST AREA. MORE -SN WITH THE SECOND TROUGH/FRONT AND A SHORTWAVE DROPPING SOUTH ACROSS MN WAS ROTATING THRU EAST CENTRAL AND NORTHEAST MN TOWARD THE FCST AREA. PATCHY -FZDZ HAD BEEN REPORTED MIXED WITH THE -SN IN THE FCST AREA...BUT IR CLOUD TOP TEMPS INDICATE ICE SEEDING SHOULD BE OCCURRING IN THE CLOUD TOPS. UPSTREAM...-SN REPORTED WITH THE PRECIP MOVING THRU THE KMSP/KSTP AREA. TEMPS ON THE MILD SIDE FOR EARLY JAN AND NEAR/AT 24HR HIGHS ACROSS MUCH OF THE FCST AREA EARLY THIS MORNING. 03.00Z MODELS INITIALIZED WELL AND AGAIN OFFER VERY SIMILAR SOLUTIONS THRU THE SHORT-TERM PERIOD. THIS WITH A MODERATELY ACTIVE NORTHWEST FLOW AND SHORTWAVE TROUGHS EITHER EXITING OR MOVING INTO THE REGION THRU SAT NIGHT. DPROG/DT OF 500MB HGTS AT 03.00Z INDICATED THE MODEL RUNS OF OF 01.00Z AND 02.00Z VERIFIED VERY WELL ACROSS NOAM BUT ALL WERE BIT FAST WITH THE NEXT SHORTWAVE TROUGH/LOW HEADED FOR THE OR/WA COAST. MODELS OFFER A TIGHT CONSENSUS TODAY/ TONIGHT AS ONE TROUGH EXITS AND HGTS QUICKLY RISE IN ITS WAKE. TIGHTER CONSENSUS CONTINUE FRI/FRI NIGHT AS THE NEXT SHORTWAVE TROUGH DROPS INTO THE NORTHERN PLAINS BUT TREND FAVORS SLOWER OF THE EARLIER RUNS WITH THIS FEATURE AT 12Z SAT. CONSENSUS LOOSENS SAT/SAT NIGHT AS THIS TROUGH MOVES ACROSS THE UPPER MIDWEST...BUT TRENDING TOWARD A COMPROMISE OF THE EARLIER RUNS. NO ONE MODEL WITH BETTER SHORT-TERM RUN-TO-RUN CONSISTENCY THIS CYCLE. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL TO BE REASONABLE WITH THE LK SUPERIOR LOW AND TROUGHS ACROSS THE REGION. MODELS AGAIN HAVING SOME DIFFICULTY WITH THE SFC DEW POINTS ACROSS THE MID/UPPER MS VALLEY. PER WV IMAGERY ALL LOOKED QUITE GOOD WITH THE SHORTWAVE DETAILS OVER NOAM/EASTERN PAC. BLEND OF MODELS REASONABLE WITH THE LIGHT PRECIP IN THE 00-06Z PERIOD ACROSS THE NORTH-CENTRAL CONUS. WITH NO ONE MODEL FAVORITE AND THE TREND TOWARD A TIGHTER CONSENSUS...AGAIN FAVORED A MODEL/ENSEMBLE BLEND. SHORT-TERM FCST CONFIDENCE REMAINS GOOD THIS CYCLE. FOR THE SHORT TERM...PER AREA WSR-88D/S...BACK EDGE OF THE -SN ACROSS MN WAS NEAR A KDLH-JUST NORTHWEST OF KMSP/KSTP LINE AT 08Z... MAKING STEADY PROGRESS SOUTHEAST. THIS BACK EDGE LINES UP WITH THE SHORTWAVE/SECONDARY MID LEVEL TROUGH AXIS OVER MN. THIS SHORTWAVE/ TROUGH AXIS DROPS SOUTHEAST THRU THE FCST AREA IN THE 09-15Z TIME- FRAME THIS MORNING...WITH A RATHER RAPID DECREASE OF MOISTURE DEPTH ONCE IT PASSES. MODELS CONTINUE TO INDICATE MOISTURE DEPTH TO ABOUT 800MB AHEAD OF THIS FEATURE...WITH 850-800MB TEMPS IN THE -10C TO -12C RANGE. WILL CONTINUE FLURRY MENTION THIS MORNING...MAINLY IN THE 12-15Z PERIOD UNTIL THE MID LEVEL TROUGH AXIS PASSES. COLD ADVECTION/DRYING SPREAD ACROSS THE AREA FOR THE LATE MORNING WITH CLOUDS EXPECTED TO DECREASE DURING THE AFTERNOON. HIGHS LOOKING TO BE IN THE 12-15Z PERIOD. TEMPS FALL DURING THE LATE MORNING WITH NORTHWEST FLOW/COLD ADVECTION BEHIND THE TROUGH THEN NEARLY STEADY DURING THE AFTERNOON. MDT/STRONG 925-850MB WARM ADVECTION QUICKLY SPREADS ACROSS THE REGION TONIGHT AS STRONG HGT RISES MOVE IN BEHIND THE DEPARTING TROUGH. LOWS TONIGHT LOOKING TO BE DURING THE EVENING THEN STEADY/SLOWLY RISE AFTER MIDNIGHT. WILL ADD THIS TREND TO THE FCST GRIDS WITH SOME SOUTHWEST WINDS 5-12KTS LATER TONIGHT. WARM ADVECTION CONTINUES FRI WITH 925MB TEMPS RISING INTO THE -2C TO +2C RANGE BY 00Z SAT. WITH A DEEP DRY AIRMASS OVER THE AREA...PLENTY OF SUNSHINE AND SOME SOUTHWEST WINDS OF 6-14KTS FOR MIXING...HIGHS FRI LOOKING TO WARM MOSTLY INTO THE 25-30F RANGE. WEAKER GRADIENT WINDS OVER THE AREA FRI NIGHT AS BROAD/WEAK LOW PRESSURE MOVES INTO MN. WITH THE DEEP...DRY AIRMASS OVER THE AREA...RADIATIONAL COOLING OVER THE SNOW COVER SHOULD ALLOW LOWS FRI NIGHT TO FALL TO NEAR NORMAL VALUES. 925-500MB AIRMASS/COLUMN COOLS WITH APPROACH OF THE NEXT MID LEVEL TROUGH. LATEST MODEL TREND IS DRIER ON THE LOW LEVEL MOISTURE INCREASE ACROSS THE AREA WITH THIS TROUGH. DUE TO THE SLOWING TREND WITH THE TROUGH...WHAT MOISTURE INCREASE THAT DOES OCCUR IS MOSTLY SAT NIGHT. EVEN THEN...THE MOISTURE IS SHALLOW...AT OR BELOW ABOUT 900MB. WITH THE SLOWER TROUGH APPROACH AND SMALLER MOISTURE INCREASE...REMOVED FLURRY MENTION FROM SAT. BASED ON THERMAL PROFILES AND LACK OF ICE IN THE LOW CLOUD/MOISTURE LAYER...IF ANY PRECIP WERE TO OCCUR SAT NIGHT IT WOULD BE -FZDZ. LEFT SAT NIGHT DRY WITH THE LIMITED MOISTURE...THE AREA BEHIND THE SFC-850MB TROUGH AXIS...AND LITTLE IF ANY LIFT IN/UNDER THE SFC-850MB INVERSION. GENERALLY FAVORED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR HIGHS/ LOWS TODAY THRU SAT NIGHT. DID AS SOME NON-DIURNAL TEMPERATURE TRENDS GRIDS FOR TODAY/TONIGHT. .LONG TERM...SUNDAY THROUGH WEDNESDAY 341 AM CST THU JAN 3 2013 03.00Z MEDIUM RANGE MODELS IN GENERAL AGREEMENT FOR TRANSITION TO ZONAL FLOW ACROSS THE NORTHERN CONUS BY TUE/WED AND A RATHER MILD JANUARY PERIOD OF WEATHER FOR THE AREA MUCH OF NEXT WEEK. LONG TERM FCST CONFIDENCE AVERAGE. GOOD MODEL CONSENSUS FOR SHORTWAVE RIDGING TO BUILD ACROSS THE REGION SUNDAY/SUN NIGHT. ANOTHER ROUND OF LOW LEVEL WARM ADVECTION SPREADS A WARM/DRY AIRMASS FROM THE CENTRAL/WESTERN PLAINS INTO THE AREA BUT A SFC RIDGE OF HIGHS PRESSURE IS OVER THE REGION FOR LIGHT WINDS AND LIMITED BOUNDARY LAYER MIXING. TEMPS TREND NEAR NORMAL FOR SUNDAY...WITH WARMING SUN NIGHT INTO MON AS GRADIENT TIGHTENS/ SFC WINDS INCREASE WITH THE NEXT TROUGH/LOW PASSING WELL NORTH OF THE FCST AREA. WITH THE FLOW TRANSITIONING TO ZONAL FOR TUE/WED... WEST/ SOUTHWEST LOW LEVEL FLOW AND WARM ADVECTION CONTINUE ACROSS THE UPPER MIDWEST. MDT PRESSURE GRADIENT LOOKS TO REMAIN OVER THE REGION TUE/WED FOR SOME SOUTHWEST WINDS AND CONTINUED BOUNDARY LAYER MIXING. MODEL CONSENSUS HIGHS IN THE MON-WED FCST GRIDS TRENDED ABOVE NORMAL AND MAY STILL BE ON THE COLD SIDE DEPENDING ON CLOUD COVER AND STRENGTH OF WINDS/LOW LEVEL MIXING. GIVEN THE PROGGED 925MB TEMPERATURES BY TUE/WED...STRONGER MIXING WOULD PUSH HIGHS THESE DAYS WELL INTO THE 40S. STAYED WITH THE MODEL/ENSEMBLE CONSENSUS HIGHS/LOWS AT THIS TIME WHICH LEAVES GRIDS WELL COLLABORATED WITH THE NEIGHBORS. && .AVIATION...THROUGH 18Z FRIDAY 1113 AM CST THU JAN 3 2013 WEAK SURFACE RIDGE CENTERED OVER NEBRASKA WITH THE RIDGE AXIS NORTH INTO MINNESOTA. MVFR CLOUDS EAST OF THE RIDGE AXIS ARE MOVING SLOWLY TO THE SOUTHEAST AND ARE EXPECTED TO CLEAR BOTH TAF SITES LATE THIS AFTERNOON. WILL SEE THE FLURRIES CONTINUE UNTIL THE CLOUDS CLEAR THE AREA AS THE 03.15Z RAP SOUNDINGS SHOW SOME WEAK OMEGA THROUGH THE SATURATED LAYER. ONCE THE CLOUDS CLEAR OUT...VFR CONDITIONS WITH CLEAR SKIES EXPECTED FOR THE REMAINDER OF THE PERIOD. THE CENTER OF THE SURFACE RIDGE WILL MOVE INTO KANSAS AND OKLAHOMA TONIGHT AND ONCE THE RIDGE AXIS MOVES THROUGH...THE AREA WILL BE IN THE PRESSURE GRADIENT FROM A SYSTEM PASSING ACROSS SOUTHERN CANADA. THIS WILL BE ENOUGH TO KEEP THE WINDS UP AROUND 10 KNOTS OUT OF THE SOUTHWEST. && .ARX WATCHES/WARNINGS/ADVISORIES... 341 AM CST THU JAN 3 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION...04