Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 02/14/12


AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
943 AM PST SUN FEB 12 2012 .DISCUSSION...AS OF 9:00 AM PST SUNDAY...LOW CLOUDS WITH POCKETS OF DENSE FOG CONTINUE ACROSS NORTH BAY VALLEYS THIS MORNING WITH A FEW REPORTS OF VIS DOWN TO LESS THAN 1/8 OF A MILE. CURRENT ADVISORY GOES UNTIL 9 AM WHICH IS THE TYPICAL TIME FOR CONDITIONS TO RAPIDLY IMPROVE...HOWEVER OBS JUST IN BEFORE THE TOP OF THE HOUR STILL SHOW LESS THAN 1/4 MILE IN SPOTS SO WILL EXTEND IT UNTIL 11 AM. OVERALL PLENTY OF CLOUDS ARE EXPECTED TODAY AS A COLD FRONT MAKES ITS WAY INTO OUR CWA. TIMING OFF THE NEW NAM AND RUC HAS CHANGED ONLY A LITTLE SO WILL LET THE CURRENT TIMING RIDE. THINK THAT RAIN WILL ENTER NAPA/SONOMA BY LATE IN THE AFTERNOON AND ACROSS OUR ENTIRE AREA OVERNIGHT. RAINFALL TOTALS DO NOT LOOK IMPRESSIVE ALTHOUGH THE WIDESPREAD NATURE OF THIS SHOULD GIVE ALMOST ALL SPOTS AT LEAST A FEW HUNDREDTHS. EVEN AREAS THAT ARE PRONE TO HIGH RAINFALL AMOUNTS (BEN LOMAND AND VENADO FOR EXAMPLE) SHOULD GET LESS THAN 1/3" BY TONIGHT. BEHIND THE FRONT WINDS WILL PICK UP GENERALLY IN A NORTH TO NORTHWEST PATTERN. 925 MB SPEEDS SHOW THE BEST VALUES OVER THE WATER AND ALONG THE COAST AND LOOKS LIKE WE COULD SEE AREAS OF WINDS CLOSE TO 50 MPH. BIGGEST CONCERN WOULD BE FROM THE SAN MATEO COASTLINE INLAND TO HIGHER ELEVATION SPOTS. SECONDARY WOULD BE AROUND PT REYES. WILL TAKE A CLOSER LOOK AT THIS AND POSSIBLE ISSUE A WIND ADVISORY FOR THOSE TWO SPOTS. .PREVIOUS DISCUSSION...SATL IMAGERY AS WELL AS SFC OBS INDC PATCHY FOG...LOCALLY DENSE IN THE NORTH BAY VALLEYS. WILL CONSIDER ISSUING A DENSE FOG ADVISORY IF THE DENSE FOG PERSISTS...BUT NAPA HAS A VIS OF 1SM. LOW CLOUDS ARE COMMON ACROSS MOST OF THE DISTRICT WITH A WEAK ONSHORE FLOW. AS OF 11Z (3 AM PST) THE GRADIENT BETWEEN SFO-SAC IS ONSHORE AT 0.8 MB AND THE GRADIENT BETWEEN SFO-WMC IS ONSHORE AT 4.3 MB. SATL IMAGERY IS INDC A SHORTWAVE PASSING 145W. THIS SHORTWAVE WILL MOVE TO THE COAST TONIGHT WITH THE ASSOCIATED COLD FRONT MOVING ACROSS THE DISTRICT OVERNIGHT. THIS SHORTWAVE WILL CUTOFF AS IT MOVES ACROSS NORTHERN AND CENTRAL CALIFORNIA ON MONDAY. RAIN TONIGHT WILL TAPER OFF TO SHOWERS ON MONDAY IN THE MOIST NW FLOW AFTER THE FRONT PASSES. THERE COULD BE EVEN ENOUGH COLD AIR TO BRING A LITTLE SNOW TO THE HIGHER PEAKS IN MONTEREY AND SAN BENITO COUNTIES. SHOWERS COULD LINGER IN THE SOUTHERN PORTIONS OF THE DISTRICT MONDAY NIGHT. ADDITIONALLY...BRISK NORTHWEST WINDS WILL DEVELOP MONDAY INTO MONDAY NIGHT WITH THE STRONGEST WINDS IN THE HILLS AND ALONG THE COAST. AS OF NOW...THE WINDS DO NOT LOOK LIKE THEY WILL REACH ADVISORY CRITERIA. MODELS ARE NOT IN AGREEMENT FOR THE NEXT UPSTREAM SYSTEM. THE GFS CUTS OFF AN UPPER LOW AND DROPS IT ALONG THE COAST LATE TUESDAY AND TUESDAY NIGHT...WHICH WOULD BRING SHOWERS TO THE DISTRICT. THE ECMWF KEEPS THE SYSTEM IN WA TUESDAY...THEN BRINGS IT SOUTHEAST THROUGH THE INTER MOUNTAIN WEST...WHICH WOULD KEEP THE DISTRICT DRY. THE 00Z GFS ENSEMBLES ARE BASICALLY SPLIT BETWEEN THE TWO SOLUTIONS. THEREFORE...HAVE KEPT A SLIGHT CHANCE OF RAIN FOR LATE TUESDAY IN THE NORTH BAY AND ACROSS THE DISTRICT TUESDAY NIGHT. MODELS DO AGREE IN BUILDING A RIDGE INTO THE STATE WEDNESDAY THROUGH FRIDAY. THIS WILL RESULT IN DRY AND MILD WEATHER. THE ECMWF BRINGS ANOTHER SYSTEM INTO THE PACIFIC NW AND NORTHERN CA FRIDAY NIGHT AND SATURDAY. HAVE KEPT THE CHC/SLT CHC OF RAIN FOR THE NORTH BAY FRIDAY NIGHT AND SAT. THE 06Z GFS IS TRENDING TOWARDS THE ECMWF SOLUTION...IF THIS TREND CONTINUES THEN POPS MIGHT NEED TO BE INCREASED FOR THIS PERIOD. && .AVIATION......AS OF 9:43 AM PST SUNDAY...SCATTERED CLOUDS AROUND THE BAY AREA WILL BEGIN TO CLEAR OUT BY LATE MORNING. FOG IN THE NORTH BAY WILL CLEAR UP AS WELL. A COLD FRONT MOVING THROUGH TONIGHT WILL INCREASSE WINDS THIS EVENING AND SPREAD RAIN FROM NORTH TO SOUTH AFTER 03Z. VICINITY OF KSFO...VFR TODAY. CIGS WILL REDEVELOP AFTER 06Z TONIGHT WITH INCREASING PRECIP CHANCES. WINDS WILL RAMP UP OVERNIGHT AS WELL WITH GUSTS OVER 20 KT BY MONDAY MORNING. KSFO BRIDGE APPROACH....SIMILAR TO SFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH 20-22Z WITH SCT CIGS THERE AFTER. CIGS REDEVELOP OVERNIGHT WITH RAIN POSSIBLE BY MONDAY MORNING. && .MARINE...AS OF 3:40 AM PST SUNDAY...NORTHWEST WINDS WILL INCREASE OVER THE COASTAL WATERS TONIGHT AS A STORM SYSTEM APPROACHES. LATEST MODELS DEVELOP GALE FORCE WINDS OVER THE OUTER WATERS TONIGHT AND MONDAY. OCCASIONAL GALE FORCE GUSTS WILL ALSO BE POSSIBLE OVER THE INNER WATERS. THE STRONG AND GUSTY WINDS WILL BE CAPABLE OF PRODUCING STEEP FRESH SWELL. IN ADDITION...THE SEA STATE WILL INCREASE WITH WAVES GREATER THAN 10 FT DEVELOPING OVER THE BAR. MARINERS VENTURING ON THE WATERS ON MONDAY SHOULD CHECK THE LATEST OBSERVATIONS AND USE CAUTION. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...DENSE FOG ADVISORY...NORTH BAY VALLEYS UNTIL 11 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 10 AM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 10 AM SCA...ROUGH BAR ADVISORY FOR SF BAR && $$ PUBLIC FORECAST: BELL/STROBIN AVIATION/MARINE: SIMS
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
903 AM PST SUN FEB 12 2012 .DISCUSSION...AS OF 9:00 AM PST SUNDAY...LOW CLOUDS WITH POCKETS OF DENSE FOG CONTINUE ACROSS NORTH BAY VALLEYS THIS MORNING WITH A FEW REPORTS OF VIS DOWN TO LESS THAN 1/8 OF A MILE. CURRENT ADVISORY GOES UNTIL 9 AM WHICH IS THE TYPICAL TIME FOR CONDITIONS TO RAPIDLY IMPROVE...HOWEVER OBS JUST IN BEFORE THE TOP OF THE HOUR STILL SHOW LESS THAN 1/4 MILE IN SPOTS SO WILL EXTEND IT UNTIL 11 AM. OVERALL PLENTY OF CLOUDS ARE EXPECTED TODAY AS A COLD FRONT MAKES ITS WAY INTO OUR CWA. TIMING OFF THE NEW NAM AND RUC HAS CHANGED ONLY A LITTLE SO WILL LET THE CURRENT TIMING RIDE. THINK THAT RAIN WILL ENTER NAPA/SONOMA BY LATE IN THE AFTERNOON AND ACROSS OUR ENTIRE AREA OVERNIGHT. RAINFALL TOTALS DO NOT LOOK IMPRESSIVE ALTHOUGH THE WIDESPREAD NATURE OF THIS SHOULD GIVE ALMOST ALL SPOTS AT LEAST A FEW HUNDREDTHS. EVEN AREAS THAT ARE PRONE TO HIGH RAINFALL AMOUNTS (BEN LOMAND AND VENADO FOR EXAMPLE) SHOULD GET LESS THAN 1/3" BY TONIGHT. BEHIND THE FRONT WINDS WILL PICK UP GENERALLY IN A NORTH TO NORTHWEST PATTERN. 925 MB SPEEDS SHOW THE BEST VALUES OVER THE WATER AND ALONG THE COAST AND LOOKS LIKE WE COULD SEE AREAS OF WINDS CLOSE TO 50 MPH. BIGGEST CONCERN WOULD BE FROM THE SAN MATEO COASTLINE INLAND TO HIGHER ELEVATION SPOTS. SECONDARY WOULD BE AROUND PT REYES. WILL TAKE A CLOSER LOOK AT THIS AND POSSIBLE ISSUE A WIND ADVISORY FOR THOSE TWO SPOTS. .PREVIOUS DISCUSSION...SATL IMAGERY AS WELL AS SFC OBS INDC PATCHY FOG...LOCALLY DENSE IN THE NORTH BAY VALLEYS. WILL CONSIDER ISSUING A DENSE FOG ADVISORY IF THE DENSE FOG PERSISTS...BUT NAPA HAS A VIS OF 1SM. LOW CLOUDS ARE COMMON ACROSS MOST OF THE DISTRICT WITH A WEAK ONSHORE FLOW. AS OF 11Z (3 AM PST) THE GRADIENT BETWEEN SFO-SAC IS ONSHORE AT 0.8 MB AND THE GRADIENT BETWEEN SFO-WMC IS ONSHORE AT 4.3 MB. SATL IMAGERY IS INDC A SHORTWAVE PASSING 145W. THIS SHORTWAVE WILL MOVE TO THE COAST TONIGHT WITH THE ASSOCIATED COLD FRONT MOVING ACROSS THE DISTRICT OVERNIGHT. THIS SHORTWAVE WILL CUTOFF AS IT MOVES ACROSS NORTHERN AND CENTRAL CALIFORNIA ON MONDAY. RAIN TONIGHT WILL TAPER OFF TO SHOWERS ON MONDAY IN THE MOIST NW FLOW AFTER THE FRONT PASSES. THERE COULD BE EVEN ENOUGH COLD AIR TO BRING A LITTLE SNOW TO THE HIGHER PEAKS IN MONTEREY AND SAN BENITO COUNTIES. SHOWERS COULD LINGER IN THE SOUTHERN PORTIONS OF THE DISTRICT MONDAY NIGHT. ADDITIONALLY...BRISK NORTHWEST WINDS WILL DEVELOP MONDAY INTO MONDAY NIGHT WITH THE STRONGEST WINDS IN THE HILLS AND ALONG THE COAST. AS OF NOW...THE WINDS DO NOT LOOK LIKE THEY WILL REACH ADVISORY CRITERIA. MODELS ARE NOT IN AGREEMENT FOR THE NEXT UPSTREAM SYSTEM. THE GFS CUTS OFF AN UPPER LOW AND DROPS IT ALONG THE COAST LATE TUESDAY AND TUESDAY NIGHT...WHICH WOULD BRING SHOWERS TO THE DISTRICT. THE ECMWF KEEPS THE SYSTEM IN WA TUESDAY...THEN BRINGS IT SOUTHEAST THROUGH THE INTER MOUNTAIN WEST...WHICH WOULD KEEP THE DISTRICT DRY. THE 00Z GFS ENSEMBLES ARE BASICALLY SPLIT BETWEEN THE TWO SOLUTIONS. THEREFORE...HAVE KEPT A SLIGHT CHANCE OF RAIN FOR LATE TUESDAY IN THE NORTH BAY AND ACROSS THE DISTRICT TUESDAY NIGHT. MODELS DO AGREE IN BUILDING A RIDGE INTO THE STATE WEDNESDAY THROUGH FRIDAY. THIS WILL RESULT IN DRY AND MILD WEATHER. THE ECMWF BRINGS ANOTHER SYSTEM INTO THE PACIFIC NW AND NORTHERN CA FRIDAY NIGHT AND SATURDAY. HAVE KEPT THE CHC/SLT CHC OF RAIN FOR THE NORTH BAY FRIDAY NIGHT AND SAT. THE 06Z GFS IS TRENDING TOWARDS THE ECMWF SOLUTION...IF THIS TREND CONTINUES THEN POPS MIGHT NEED TO BE INCREASED FOR THIS PERIOD. && .AVIATION......AS OF 3:40 AM PST SUNDAY...AMPLE LOW LEVEL MOISTURE REMAINS FROM YESTERDAY WITH CIGS 1-2K FEET THIS MORNING. LATEST GUIDANCE AND TRENDS SUGGEST THAT CIGS WILL LAST WELL INTO THE MORNING RUSH. WILL KEEP CLEARING TIMES FOR THIS AFTERNOON. ANOTHER SYSTEM WILL MOVE IN TONIGHT WITH PRECIP SPREADING N-S AFTER 03Z. IN ADDITION TO PRECIP...WINDS WILL RAMP UP OVERNIGHT. CONF IS MEDIUM. VICINITY OF KSFO...CIGS IN THE MVFR RANGE WILL KEEP MUCH OF THE BAY COVERED THIS MORNING. WILL KEEP PREVIOUS FORECAST GOING WITH LIFTING CIGS AFTER 21Z THIS AFTERNOON. WILL REDEVELOP CIGS AFTER 06Z TONIGHT WITH INCREASING PRECIP CHANCES. WINDS WILL RAMP UP OVERNIGHT AS WELL WITH GUSTS OVER 20 KT ON MONDAY. KSFO BRIDGE APPROACH....SIMILAR TO SFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH 20-22Z WITH SCT CIGS THERE AFTER. CIGS REDEVELOP OVERNIGHT WITH RAIN POSSIBLE BY TOMORROW MORNING. && .MARINE...AS OF 3:40 AM PST SUNDAY...NORTHWEST WINDS WILL INCREASE OVER THE COASTAL WATERS TONIGHT AS A STORM SYSTEM APPROACHES. LATEST MODELS DEVELOP GALE FORCE WINDS OVER THE OUTER WATERS TONIGHT AND MONDAY. OCCASIONAL GALE FORCE GUSTS WILL ALSO BE POSSIBLE OVER THE INNER WATERS. THE STRONG AND GUSTY WINDS WILL BE CAPABLE OF PRODUCING STEEP FRESH SWELL. IN ADDITION...THE SEA STATE WILL INCREASE WITH WAVES GREATER THAN 10 FT DEVELOPING OVER THE BAR. MARINERS VENTURING ON THE WATERS ON MONDAY SHOULD CHECK THE LATEST OBSERVATIONS AND USE CAUTION. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...DENSE FOG ADVISORY...NORTH BAY VALLEYS UNTIL 11 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 10 AM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 10 AM SCA...ROUGH BAR ADVISORY FOR SF BAR FROM 9 AM && $$ PUBLIC FORECAST: BELL/STROBIN AVIATION/MARINE: MM
AREA FORECAST DISCUSSION
NWS ALBANY NY
113 AM EST SUN FEB 12 2012 .SYNOPSIS... ARCTIC AIR WILL CONTINUE TO MOVE INTO THE REGION THIS MORNING. ANOTHER DISTURBANCE WILL MOVE SOUTH OF THE THE REGION TODAY. AS IT MOVES ACROSS LAKE ONTARIO IT WILL TRIGGER LAKE EFFECT SNOW IN PARTS OF THE REGION. HIGH PRESSURE WILL BUILD OVER THE EASTERN HALF OF THE NATION MONDAY INTO TUESDAY. TEMPERATURES WILL MODERATE AS THIS HIGH SLIDES OFFSHORE MIDWEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1 AM EST...SOME MINOR UPDATES TO NEAR TERM FORECAST. OBSERVATIONS AND NEWEST NAM DATA WERE USED TO REFRESHEN HOURLY T/TDS/RH AND APPRARENT TEMPS. THE BEST CHANCE TO HIT MARGINAL WIND CHILL ADVISORY WILL BE IN THE SRN DACKS WITH VALUES AROUND -20F TO -24F. IN THE SOUTHERN GREENS...IT WILL BE CLOSE WITH WIND CHILLS IN THE HIGH PEAKS AROUND -20F. THE WINDS MAY KEEP THE TEMPS UP A BIT IN THE VALLEYS. WE RAISED MIN TEMPS A FEW DEGREES IN THE MID HUDSON REGION...AND CAPITAL REGION. ALSO...WE LOWERED THE POPS TO BELOW 20 PERCENT WITH SCATTERED FLURRIES THIS MORNING FROM ALBANY SOUTH AND WEST. SOME LAKE EFFECT SNOW SHOWERS MAY SNEAK IN TOWARDS SUNRISE WEST OF THE HUDSON RIVER VALLEY IN THE NW FLOW...WITH MULTIBANDS. THE BEST CHANCE OF A COATING TO AN INCH OR SO WILL BE IN THE WRN MOHAWK VALLEY...AND ERN CATSKILLS. SKY GRIDS WERE ALSO RETOOLED BASED ON THE 3.9-11 MICRON SATELLITE CURVE. IT WILL BE COLD WITH H850 TEMPS APPROACHING -20F OVER THE NRN TIER...AS BRIEF PERIOD OF ARCTIC AIR MOVES IN FOR THE FCST AREA. PREVIOUS NEAR TERM... AS OF 945 PM...TEMPERATURES CONTINUE TO DROP AND WINDS REMAIN ELEVATED. PER THE LATEST LAMP/LAV GUIDANCE AND MESONET OBS...SEEMS WE WILL HAVE WIND CHILL ISSUES FOR PORTIONS OF THE DACKS AND SOUTHERN GREENS. WE WILL HOIST WIND CHILL ADVISORIES AT THIS TIME. OTHERWISE...A COMBINATION OF SOME LOW STRATUS ACROSS THE HUDSON RIVER VALLEY AND DEPARTING MID AND HIGH LEVEL MOISTURE ARE MAKING FOR A CHALLENGING SKY FORECAST. STILL EXPECT SUBSIDENCE AND MIXING TO REDUCE CLOUD COVER FURTHER BEFORE RETURNING LATE TONIGHT DOWNWIND OF LAKE ONTARIO. HAVE LOWERED TEMPERATURES A COUPLE OF DEGREES AND INCREASED WINDS SLIGHTLY. AS OF 645 PM...A MESOSCALE FEATURE WAS ROTATING ACROSS THE SCHOHARIE VALLEY AND TRACKING ACROSS THE EASTERN CATSKILLS THIS EARLY EVENING. HRRR SEEMS TO HAVE A HINT OF THIS FEATURE AS IT SHOULD CONTINUE TO TRACK SOUTHWARD AND WEAKEN TOWARD 03Z. EXPECTATIONS ARE FOR A LULL IN THE PRECIP COVERAGE BETWEEN 03Z-09Z OVERNIGHT AS THE COMBINATION OF THE DRIER AIR ADVECTING INTO THE REGION AND A BRIEF WINDOW OF SUBSIDENCE. SO FOR THIS UPDATE...WE WILL CARRY POPS FOR THE SOUTHERN 1/3RD OF NY COUNTIES THEN GO DRY FOR THAT PERIOD OF 03-09Z. PER THE LATEST NAM12/HRRR/RUC13...SEEMS THE BEST TRAJECTORY FOR LAKE EFFECT SETS UP A LITTLE MORE NORTHWEST THAN PREVIOUS RUNS. THIS WOULD LIMIT THE SNOW MIGRATING THROUGH THE MOHAWK VALLEY. WE WILL AWAIT FOR THE 00Z GUIDANCE BEFORE MAKING ADDITIONAL ENHANCEMENTS TO THE GRIDS/FORECAST. && .SHORT TERM /6 AM SUNDAY THROUGH TUESDAY/... A FAIR AMOUNT OF AGREEMENT AMONG GFS/NAM/CMC DURING THIS PERIOD. AT 500HPA CUT OFF TROF IS LIFTING INTO N ATLC. RIDGE AXIS IS BUILDING FM SE USA TO N GRT PLAINS. MODELS ALL SHOW A WK LK RESPONSE SIGNAL AS WHAT WAS A CDFNT LIFTS BACK NE THROUGH RGN INTO QB MON. IT MAY FOCUS SOME -SHSN INTO W FCA OR IS BEING ENHANCED BY WK WAA. BUT WITH INVERSION HGT AT 5KFT NOT EXPECTING MUCH SUN NT IN WAY OF -SHSN. MONDAY WITH 500HPA RIDGE AXIS TO OUR W...SFC HIGH SHIFTING TO EAST COAST SHOULD BE A FAIR DAY WITH MODERATING TEMPS AFTER A COLD START. MONDAY NT SFC HIGH SLIDES OFFSHORE AND 500HPA FLOW RETURNS TO A ZONAL PATTERN WITH A FEW EMBEDDED WEAK SHORT WAVES. A SERIES OF WEAK 500HPA SHORT WVS APPROACH LATE MON AND TUES WITH INCRG CLOUDS TUES MORNING. MIDWEEK FINDS FCA IN ANOTHER MODIFIED MARITIME POLAR AIR MASS THAT HAS TRAVELED ZONALLY ACROSS MUCH OF THE USA. SFC HIGH OFFSHORE SETS UP SW FLOW W/FAIR AMOUNT OF CLOUDINESS...AND MAYBE SOME LT PCPN OF VARIOUS FORMS MAINLY DZ OR FZDZ IN THE EARLY MORNING HRS. NOT MUCH DYNAMICALLY GOING ON...JUST CLOUDS STUCK UNDER INVERSIONS. TEMPS WELL ABV NORMALS AFTER A CHILLY START MONDAY MORNING. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... STILL A CHALLENGING LONG TERM PORTION OF THE FORECAST AS SEVERAL KEY SHORT WAVES WERE SITUATED OVER THE NORTH PACIFIC THAT WILL HAVE IMPLICATIONS FOR THE END OF NEXT WEEK. WE BEGIN THIS LONG TERM FORECAST WITH A DEPARTING WAVE. MAINLY CLOUDS ARE EXPECTED WITH THIS SYSTEM WITH GRADUAL IMPROVEMENTS EXPECTED THROUGH THE DAY. EXCEPTION WOULD BE ACROSS THE HIGHER TERRAIN AS MOIST LOW-MID LEVELS AND UPSLOPING CONDITIONS SHOULD RESULT IN ENHANCED CLOUD COVER A BIT LONGER. BOUNDARY LAYER TEMPERATURES ARE EXPECTED TO MODERATE SO ANY SNOW IN THE VALLEYS SHOULD REDUCE. THEN A RIDGE OF HIGH PRESSURE IS EXPECTED FROM LATE WEDNESDAY INTO THURSDAY. THIS WILL KEEP OUR WEATHER TRANQUIL FOR THE MAJORITY OF THE REGION. THE MINOR EXCEPTION TO THIS WOULD BE DOWNWIND OF LAKE ONTARIO WHERE A WEAK THERMAL TROUGH MAY BE ENOUGH TO PRODUCE A MINOR LAKE RESPONSE AND WILL KEEP POPS LOW AT THIS TIME. TEMPERATURES DURING THIS TIME FRAME WILL AVERAGE A BIT ABOVE NORMAL FOR THIS TIME OF THE YEAR. THEN THE RATHER COMPLEX FORECAST FOR THURSDAY-FRIDAY TIME FRAME. OUR POTENTIAL WAVE...PER THE 1.5PVU TRACE AND H2O VAPOR LOOP ANALYSIS...WAS CURRENTLY TRACKING ALONG 45N AND JUST EAST OF 160W. SATELLITE REPRESENTATION DOES SUGGEST THIS WAVE IS STRONG AS IT RACES EAST TOWARD THE PACIFIC COASTLINE OF NOAM. NCEP MODEL SUITE AN INTERNATIONAL GUIDANCE ALL OFFER A UNIQUE APPROACH THAT WILL HAVE LARGE IMPLICATIONS ON OUR WEATHER. THE ECMWF WHICH HAS WAVERED A BIT THE PAST SEVERAL RUNS...RETURNS WITH A RATHER STRONG SYSTEM IMPACTING THE NORTHEAST. THE GFS REMAINS QUITE PROGRESSIVE AND FAVORS A STRONGER HUDSON BAY LOW /AND A MORE POSITIVE NAO/. THE CANADIAN TAKES THE STRONG BALANCE OF THESE AFOREMENTIONED FEATURES WHICH SLOWS DOWN THE FORWARD PROGRESS OF THE PENDING EVENT BY ABOUT 1 DAY /ALSO A WARMER SOLUTION/. PLUMES/ENSEMBLES FROM THE GFS REVEAL A CLUSTERING OF SOLUTIONS OF FURTHER SOUTHWARD TRACK AND MORE PROGRESSIVE. ALTHOUGH WE CAN NOT RULE OUT THE ECMWF WHICH A COUPLE OF THE GFS PERTURBATIONS DO AGREE WITH ITS OPERATIONAL SOLUTION. SO A LOW CONFIDENCE FORECAST AT THIS TIME AND WILL KEEP POPS AROUND THE 30% THRESHOLDS WHICH IS IN AGREEMENT WITH HPC AND NEIGHBORING FORECAST OFFICES. BOUNDARY LAYER TEMPS WILL ALSO BE TRICKY AS THE RAIN/SNOW ISSUE IS EXPECTED TO BECOME A FACTOR AS WELL. A CYCLONIC FLOW REGIME IS EXPECTED FOR THE START OF NEXT WEEKEND WITH SOME SHOWER ACTIVITY AND PERHAPS SOME LAKE ONTARIO CONTRIBUTION WHICH WILL BE HIGHLY DEPENDENT ON HOW MUCH COLD ADVECTION TAKES PLACES IN THE WAKE OF THE THURSDAY-FRIDAY EVENT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... WILL HAVE CYCLONIC FLOW ACROSS THE REGION THROUGH THE TAF PERIOD...06Z/MONDAY...WITH COLDER AIR BEING USHERED IN. CLOUD COVER WILL CONTINUE TO DECREASE EARLY MORNING...HOWEVER CLOUDS WILL INCREASE AFTER SUNRISE AS THE COLDER AIR PICKS UP MOISTURE OFF THE GREAT LAKES. VFR CONDITIONS ARE EXPECTED. MVFR CLOUDS WILL BE POSSIBLE AT KALB THIS EVENING AS THE FLOW COMES DOWN THE MOHAWK VALLEY AND LOWER LAKE EFFECT CLOUDS MOVE INTO THE AREA. WINDS WILL BE NORTHWESTERLY AND GUSTY TODAY ESPECIALLY AFTER SUNRISE AND THROUGH THE AFTERNOON HOURS. WINDS SPEED WILL DECREASE THIS EVENING WITH GUSTS HOLDING ON AT KALB. OUTLOOK... MON...VFR. BRISK WESTERLY WIND. TUE-WED...VFR. SLIGHT CHC -SHSN/-SHRA THU...VFR. CHC RAIN IN THE THE AFTN. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. SOME GAGES WILL CONTINUE TO BE IMPACTED BY ICE ACROSS NORTHERN PORTIONS OF THE HYDROLOGIC SERVICE AREA. COLDER AIR WILL BE USHERED IN THE REGION TONIGHT AND SHOULD LEAD TO SOME ADDITIONAL ICE FORMATION ESPECIALLY ACROSS THE SOUTHERN ADIRONDACKS...AND AREAS NORTH OF THE MOHAWK RIVER VALLEY. HOWEVER...TEMPERATURES WILL MODERATE TO ABOVE NORMAL NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR NYZ032-033. MA...NONE. VT...WIND CHILL ADVISORY UNTIL 9 AM EST THIS MORNING FOR VTZ013-014. && $$ SYNOPSIS...SNYDER/WASULA NEAR TERM...BGM/WASULA SHORT TERM...SNYDER LONG TERM...BGM AVIATION...IAA HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS WICHITA KS
1151 AM CST SUN FEB 12 2012 .UPDATE... MADE SOME TWEAKS EARLIER TO THE GRIDS TO INCREASE CLOUDS AND LOWER MAXES. RUC ONCE AGAIN HAS HAD BEST HANDLE ON CLOUDS...AND ITS TEMPERATURE FORECASTS FOR THIS AFTERNOON LOOK REASONABLE GIVEN THE EXTENSIVE CLOUDS AND WINDS. WITH SLIGHTLY SLOWER ONSET TO BEST LIFT/DEEPER MOISTURE...HAVE NIXED FLURRIES IN THE EXTREME WEST SECTIONS FOR LATE THIS AFTERNOON. -HOWERTON && .AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU MESSY AVIATION FORECAST WITH DETERIORATING CONDITIONS UNTIL LATE IN THE FORECAST. OVERCAST VFR CEILINGS SHOULD OVERSPREAD KCNU VERY EARLY IN THE FORECAST. MEANWHILE COMBO OF INCREASING LOW LEVEL MOISTURE/SYNOPTIC SCALE LIFT AHEAD OF RESPECTABLE UPPER TROUGH SHOULD GRADUALLY LOWER CEILINGS AND INCREASE CHANCES FOR PRECIPITATION THIS EVENING/OVERNIGHT. MODEL PRECIPITATION TYPE CONTINUE TO BE PROBLEMATIC WITH COLDEST SATURATION PERIODICALLY DROPPING TO THE -5 TO -10C RANGE WHICH COULD RESULT IN MIXED AND OR FREEZING PRECIPITATION. GIVEN DIFFICULTIES OF TIMING AND UNCERTAINTY IN MODEL SOLUTIONS...HAVE OPTED TO EITHER KEEP IT SNOW OR A RAIN AND SNOW MIX FOR NOW. PLAN IS TO AMEND IF/WHEN CHANCES FOR FREEZING PRECIPITATION BECOME MORE LIKELY/TIMING MORE CERTAIN. IFR CONDITIONS ARE EXPECTED TO DEVELOP AS PRECIPITATION SATURATES LOWEST LEVELS. SOME SLIGHT IMPROVEMENT IS ANTICIPATED LATE IN THE PERIOD. -HOWERTON && .PREV DISCUSSION... /ISSUED 535 AM CST SUN FEB 12 2012/ AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU VFR CONDITIONS EXPECTED TODAY...THEN DETERIORATING TO MVFR IN MOST LOCALES TONIGHT IN AREAS OF LIGHT SNOW. SURFACE HIGH PRESSURE WILL MOVE EAST AND AWAY FROM THE REGION TODAY...AS LOW PRESSURE ALOFT ACROSS SOUTHERN UTAH/NORTHERN ARIZONA MOVES EAST ACROSS THE ROCKIES AND OUT ACROSS THE HIGH PLAINS TONIGHT. MOISTURE AND LIFT IN ADVANCE OF THIS SYSTEM WILL RESULT IN AREAS OF LIGHT SNOW BY THIS EVENING ACROSS SOUTH CENTRAL KANSAS...WHICH WILL SPREAD NORTH AND EAST ACROSS MOST OF THE AREA LATER TONIGHT. SOUTH WINDS WILL ALSO BECOME BRISK AND GUSTY LATER TODAY AND CONTINUE THROUGH TONIGHT. THERE IS HIGH CONFIDENCE IN AT LEAST LOW END MVFR CAT CIGS AND VSBYS IN THE LIGHT SNOW...WITH POTENTIAL FOR PERIODS OF IFR CIGS AND VSBYS TOWARD THE END OF THE FORECAST VALID PERIOD. HOWEVER WILL OMIT THIS LOWER END POSSIBILITY IN THE TAFS FOR NOW. KED PREV DISCUSSION... /ISSUED 340 AM CST SUN FEB 12 2012/ DISCUSSION... FORECAST HIGHLIGHTS/CHALLENGES CONTINUE TO FOCUS AROUND SNOW & FREEZING DRIZZLE TONIGHT-MONDAY. TODAY: CHILLY ARCTIC HIGH PRESSURE WILL MOVE EAST TODAY AS LOW PRESSURE CONTINUES TO STRENGTHEN TO THE WEST...ALLOWING FOR STRENGTHENING SOUTHERLY WINDS ACROSS THE KANSAS REGION. WITH THE STRENGTHENING SOUTHERLY FLOW WILL COME SOMEWHAT WARMER TEMPERATURES...ALTHOUGH WARMING WILL BE TEMPERED BY INCREASING MID/UPPER CLOUDS AHEAD OF THE NEXT STORM SYSTEM. TONIGHT-MONDAY: MAIN FORECAST CONCERN WILL BE TONIGHT-MONDAY...AS A STORM SYSTEM CURRENTLY OVER THE DESERT SOUTHWEST LIFTS NORTHEAST AND SPREADS A VARIETY OF LIGHT WINTRY PRECIPITATION ACROSS MID-AMERICA. ANTICIPATING LIGHT/MODERATE SNOW TO GRADUALLY SPREAD NORTHEAST INTO SOUTH-CENTRAL KANSAS THIS EVENING...EVENTUALLY EXPANDING TO INCLUDE MOST AREAS WEST OF THE FLINT HILLS BY MIDNIGHT...AS 800-600MB ISENTROPIC ASCENT INCREASES AHEAD OF THE STORM SYSTEM. LIGHT/MODERATE SNOW WILL THEN MOVE INTO EASTERN KANSAS LATER TONIGHT...GENERALLY ALONG/EAST OF THE FLINT HILLS...GRADUALLY EXITING AREAS WEST OF THE FLINT HILLS AS A MID-LEVEL DRY SLOT MOVES IN. HOWEVER...EVEN THOUGH THE SNOW SHOULD MOVE OUT...AM FAIRLY CONFIDENT IN FREEZING DRIZZLE BEHIND THE SNOW...DUE TO PERSISTENT LOW-LEVEL ISENTROPIC ASCENT/MOISTENING UNDERNEATH THE DRY MID-LEVELS. THINKING BY MID TO LATE MORNING MONDAY...MOST OF THE ACCUMULATING SNOW WILL HAVE MOVED EAST INTO MISSOURI...BUT A HIGH LIKELIHOOD OF FREEZING DRIZZLE SHOULD CONTINUE ACROSS MUCH OF THE AREA. FROM LATE MONDAY MORNING THROUGH MONDAY AFTERNOON...THE FREEZING DRIZZLE THREAT WILL GRADUALLY WANE FROM WEST TO EAST...AS INCREASING WEST/NORTHWEST FLOW SHOULD DECREASE LOW-LEVEL LIFT/MOISTENING. ADDITIONALLY...TEMPERATURES SHOULD CLIMB TO NEAR THE MID 30S MONDAY AFTERNOON...WHICH COULD CHANGE THE LIGHT PRECIPITATION TO ALL LIQUID OVER ESPECIALLY SOUTHERN KANSAS. GIVEN PROGRESSIVE NATURE OF THIS WAVE AND ONLY MODEST FORCING...ANTICIPATING SNOW ACCUMULATIONS OF 1-2 INCHES ACROSS THE AREA...LIKELY HIGHEST OVER FAR EASTERN KANSAS...WITH AMOUNTS ONE INCH OR LESS OVER CENTRAL KANSAS. THE BIGGER CONCERN WILL LIKELY BE THE FREEZING DRIZZLE. WHILE MAJOR ICE ACCUMULATIONS ARE NOT ANTICIPATED...A LIGHT GLAZE APPEARS LIKELY ON TOP OF THE INCH OR TWO OF SNOW...WHICH WILL MAKE FOR HAZARDOUS TRAVEL. THEREFORE...A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR GENERALLY THE EASTERN HALF OF KANSAS THIS EVENING THROUGH LATE MONDAY AFTERNOON. TUESDAY-SATURDAY: DESPITE SOME MODEL DISAGREEMENT...THE GENERAL CONSENSUS SUGGESTS ANOTHER FAST MOVING STORM SYSTEM MAY BRING SOME LIGHT PRECIPITATION TO THE REGION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. HOWEVER...THIS GO AROUND PRECIPITATION SHOULD BE PREDOMINATELY LIQUID DUE TO WARMER TEMPERATURES...ALTHOUGH A MIX IS POSSIBLE ESPECIALLY OVER THE NORTHERN HALF OF KANSAS. TEMPERATURES TUESDAY AND BEYOND LOOK TO REBOUND TO NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS INTO THE 40S-50S...WITH NO MAJOR STORM SYSTEMS ON THE HORIZON BEYOND MID-WEEK. KLEINSASSER AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU SOLE CONCERN THRU EARLY SUN EVENING IS THAT OF WINDS BECOMING DUE SLY & GREATLY INCREASE...ESPECIALLY OVER CNTRL KS WHERE SUSTAINED 22-25KTS ARE LIKELY BY 17Z WITH 30-35KT GUSTS. SUCH VELOCITIES WOULD OCCUR OVER ALL EXCEPT KCNU WHERE SUSTAINED SPEEDS SHOULD NOT EXCEED 15KTS. CIGS TO MAINTAIN VFR STATUS WITH 6,000-8,000FT CIGS SPREADING OVER ALL TERMINALS 17Z/18Z. FOR THE 13/00Z-13/06Z RAPID DETERIORATION OF CIGS & VSBYS STILL ANTICIPATED OVER ALL 5 TERMINALS AS LOW PRESSURE SITUATED OVER THE WRN PLAINS CONTINUES TO STRENGTHEN. THIS WOULD PROMOTE INCREASING WARM/MOIST ADVECTION IN LOWEST ~8,000FT OF AIRMASS. CONFIDENCE REMAINS HIGH THAT A WINTRY MIX WILL SPREAD NE ACROSS KS 03Z-06Z TIMEFRAME. DID NOT PROVIDE DETAILS ON THESE LAST 3 HOURS OF FCST SO AS TO ALLOW SUCCESSORS CHANCE TO STUDY HOW THIS PATTERN WILL EVOLVE. EPS FIRE WEATHER... SOUTHERLY WINDS WILL INCREASE MARKEDLY TODAY AS LOW PRESSURE STRENGTHENS TO THE WEST...WHICH WILL LIKELY RESULT IN A PERIOD OF "VERY HIGH" GRASSLAND FIRE DANGER THIS AFTERNOON OVER CENTRAL KANSAS. OTHERWISE...WIDESPREAD PRECIPITATION AND CLOUDS WILL OVERSPREAD THE REGION TONIGHT...AND PERSIST INTO MONDAY...AS A STORM SYSTEM APPROACHES FROM THE SOUTHWEST. SNOW ACCUMULATIONS WILL LIKELY RANGE FROM ONE INCH OR LESS OVER CENTRAL KANSAS...TO 1-3 INCHES OVER EASTERN KANSAS. ADDITIONALLY...FREEZING DRIZZLE IS A HIGH LIKELIHOOD. OTHERWISE...TEMPERATURES WILL GRADUALLY REBOUND TO NEAR SEASONAL NORMALS TUESDAY AND BEYOND...WITH MAYBE ANOTHER ROUND OF LIGHT PRECIPITATION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. KLEINSASSER && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 33 27 36 25 / 10 80 50 0 HUTCHINSON 31 27 35 24 / 10 80 40 0 NEWTON 33 27 34 25 / 0 80 50 0 ELDORADO 34 27 35 24 / 0 80 50 10 WINFIELD-KWLD 33 28 37 24 / 10 80 50 0 RUSSELL 32 26 35 22 / 10 50 30 0 GREAT BEND 32 26 36 22 / 10 50 30 0 SALINA 35 27 36 23 / 10 70 40 0 MCPHERSON 33 27 35 24 / 10 70 40 0 COFFEYVILLE 37 28 36 27 / 0 90 90 10 CHANUTE 35 27 34 25 / 0 90 90 10 IOLA 35 26 34 25 / 0 90 90 10 PARSONS-KPPF 36 27 34 25 / 0 90 90 10 && .ICT WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY FOR KSZ053-070>072-094>096-098>100. WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 6 PM CST MONDAY FOR KSZ049>052-067>069-082-083-091>093. && $$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
721 PM CST MON FEB 13 2012 .UPDATE... LATEST RUC WARMS SURFACE TEMPERATURES ABOVE FREEZING OVER MUCH OF THE AREA BY 06Z. 01Z METARS INDICATE THAT MOST AREAS OVER SOUTHERN ILLINOIS...SOUTHEAST MISSOURI AND WEST KENTUCKY ARE ALREADY BACK UP TO THE FREEZING MARK...WHICH WOULD SUPPORT THE RUC SOLUTION. GROUND TRUTH REPORTS INDICATE THAT THE MODERATE TO HEAVY SNOW HAS ALREADY TRANSITIONED TO A MIX OF LIGHT SNOW...SNOW PELLETS AND RAIN/FREEZING RAIN AS OF 01Z...WHICH MEANS THAT THE SNOW AMOUNTS WILL NEED TO BE SLASHED SIGNIFICANTLY. CURRENTLY FEEL THAT A DUSTING OF SNOW WILL BE POSSIBLE IN THE EVANSVILLE AREA BEFORE THE MIXTURE ARRIVES THERE. ONCE THE LIGHT RAIN BEGINS SOME LIGHT ICING OF ELEVATED SURFACES WILL BE POSSIBLE IN AREAS WHERE TEMPERATURES ARE AT OR JUST BELOW FREEZING. OBSERVATIONS HERE AT THE OFFICE INDICATE THAT ROADS SHOULD REMAIN WET...SO TRAVEL IMPACTS ARE NOT LIKELY TO BE AS BAD AS ORIGINALLY EXPECTED. WILL HAVE TO WATCH SURFACE TEMPERATURES CLOSELY THROUGH THE EVENING...AND MAY BE ABLE TO CLEAR A PORTION OF THE ADVISORY BEFORE MIDNIGHT. EXPECT A SIGNIFICANT UPDATE BY 9 PM. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 303 PM CST MON FEB 13 2012 HAVE MADE SOME MINOR ADJUSTMENTS TO THE FORECAST FOR THIS PERIOD. UPPED SNOW AMOUNTS AS WE ALREADY HAVE REPORTS OF MORE THAN AN INCH IN SOUTHEAST MISSOURI. HAVE ALSO EXTENDED THE ADVISORY TIL 8AM CST FOR THE NORTHEAST AREA AS THE TEMPERATURES MAY NOT GET ABOVE FREEZING THERE UNTIL THAT TIME. USED A COMBINATION OF NAM AND GFS SOUNDINGS TO DETERMINE PRECIP TYPE. ESSENTIALLY DEEP MOISTURE MOVING ACROSS THE AREA LATE THIS AFTERNOON AND EVENING. THIS SHOULD RESULT IN ALL SNOW FOR ALL AREAS INITIALLY. STILL EXPECT THE HEAVIER SNOW TO REACH THE MISSISSIPPI RIVER BY 4-5 PM AND THE WABASH RIVER BETWEEN 8-9PM. THE BEST TIME FOR SIGNIFICANT PRECIP WILL BE DURING THE EVENING HOURS WHEN 500-300 MB DIV Q MOVES ACROSS THE AREA...SOME WEAK FRONTOGENESIS ON THE NAM (NOT THE GFS) DURING THE EARLY EVENING TOO. SOUNDINGS SUGGEST THAT FAVORABLE LAPSE RATES JUST BELOW THE DENDRITIC GROWTH ZONE FAVORING GOOD CRYSTAL GROWTH...ARE ALSO MOVING ACROSS THE AREA THIS EVENING. QPF AMOUNTS ARE EXPECTED TO BE LESS THAN .20 FOR THE EVENT AND IT MAY NOT ALL BE SNOW. FOLLOWED WWD PRETTY CLOSELY WITH SNOW AMOUNTS. THIS IS NOT A CLEAR CUT SNOW FORECAST AS THE MODELS DRY OUT THE MAIN CRYSTAL GROWTH AREA OVERNIGHT OVER ALMOST ALL OF THE CWA...BUT IT WILL BE A GRADUAL THING. SOUNDINGS KEEP MOST AREAS BELOW FREEZING BUT WITHOUT CRYSTALS...NO SNOW. SO HAVE ADVANCED LIGHT FREEZING RAIN/DRIZZLE ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST. ALSO HAVE THE ISSUE OF TEMPERATURES RISING TO ABOVE FREEZING OVER THE SOUTHEAST BEFORE MORNING. SO PRECIPITATION TYPES HAVE BEEN QUITE A CHALLENGE. WITH THE HEAVIER SNOW AMOUNTS EXPECTED IN THE NORTHEAST WITH A LONGER SNOWFALL TIME...THEN ADDING SOME FREEZING PRECIPITATION ON TOP...HAVE EXTENDED THE ADVISORY TIL 8AM. THINKING THAT THE MORNING COMMUTE IN THE NORTHEAST COULD BE MESSY. THE SYSTEM PULLS OUT DURING THE DAY TOMORROW...BUT MODELS KEEP SOME LOW LEVEL MOISTURE IN THE AREA AND THUS KEPT CLOUDS IN A BIT LONGER THAN PREVIOUSLY THOUGHT. THUS ALSO LOWERED TEMPERATURES FOR TOMORROW. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 303 PM CST MON FEB 13 2012 MODELS IN DECENT AGREEMENT THAT AFTER BRIEF BUBBLE AND PRECIP FREE CONDITIONS LATER TUE/TUE NIGHT...FAST PROGRESSIVE UPPER FLOW WILL BRING ANOTHER FAIRLY POTENT SYSTEM THROUGH THE REGION...ESP WED AFTN AND WED NIGHT. BIG DIFFERENCE THIS TIME IS THAT THE SFC LOW WILL BE STRONGER, AND TRACK MUCH FARTHER NORTH THROUGH CNTRL IL. IN FACT WILL INSERT SOME THUNDER CHC AS SHOWALTER INDICES FALL TO NEAR OR BELOW ZERO WED PM...ESP OVER SE MO AND WRN KY. WILL ALSO BE SOMEWHAT OF A GULF FETCH WITH THIS AND THE MID LVL SYSTEM WILL BE MORE DYNAMIC. THUS...THO IT IS A BIT TOO EARLY TOO GET SPECIFIC ABOUT EXACT RAIN AMOUNTS. BEST GUESS RIGHT NOW WOULD BE IN THE 1/2 INCH TO 3/4 INCH RANGE OVER MUCH OF THE REGION. THEREAFTER...THU THRU MON...LOOKS LIKE AN EXTENDED DRY PERIOD WITH LOWS NEAR 30 AND HIGHS UP AROUND 50 TO THE LOWER 50S AS HIGH PRESSURE SETTLES SLOWLY IN FROM THE WEST. THIS IS VERY CLOSE TO MEX/HPC MOS GUIDANCE. && .AVIATION... SNOW THIS EVENING WILL GRADUALLY CHANGE TO LIGHT FREEZING RAIN FOR A FEW HOURS...THEN ALL SITES SHOULD WARM ENOUGH TO BECOME JUST RAIN BETWEEN 08Z AND 14Z. MVFR TO IFR CONDITIONS EXPECTED OVERALL...BUT BUT BRIEF LIFR CONDITIONS ARE POSSIBLE WITH HEAVIER PRECIPITATION. WINDS WILL BE FROM THE SOUTH AT 5 TO 12 KTS. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR KYZ001>013- 016-017-021-022. WINTER WEATHER ADVISORY UNTIL 8 AM CST TUESDAY FOR KYZ014-015- 018>020. MO...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR MOZ076-086- 087-100-107>112-114. IL...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR ILZ075-076- 080>082-084>086-088>094. WINTER WEATHER ADVISORY UNTIL 8 AM CST TUESDAY FOR ILZ077-078- 083-087. IN...WINTER WEATHER ADVISORY UNTIL 8 AM CST TUESDAY FOR INZ081-082- 085>088. && $$ UPDATE.......DRS SHORT TERM...PS LONG TERM....GM AVIATION.....RST
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1007 AM EST SUN FEB 12 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD ACROSS THE REGION THIS AFTERNOON THROUGH MONDAY. AN UPPER LEVEL DISTURBANCE COULD BRING PRECIPITATION TO THE REGION LATE MONDAY NIGHT AND ON TUE. ANOTHER DISTURBANCE COULD BRING PRECIPITATION TO THE REGION ON THURDAY...THEN A COLD FRONT WILL FOLLOW BY THE END OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... DEPP UPPER LEVEL TROUGH HAS MOVED OFF THE EASTERN SEABOARD THIS MORNING. TIGHT PRESSURE GRADIENT FROM DEEP SURFACE LOW IN THE CANADIAN MARITIMES COUPLED WITH HIGH PRESSURE OVER THE SRN PLAINS AND LOWER MS VALLEY WILL KEEP GUSTING NW WINDS ACROSS THE REGION TODAY. FORECAST TEMPERATURES ARE WELL BELOW NORMAL FOR THE FIRST TIME IN A LONG TIME...MORE IN LINE WITH A TYPICAL FEB WINTER DAY. UPSLOPE SNOW CONDITIONS CONTINUE IN THE FAR WESTERN ZNS...ALTHOUGH SURFACE WINDS BECOMING MORE SW ARE NOT CONDUCIVE TO DECENT UPSLOPE. DOT CAMERAS AND OTHER WEB IMAGES SHOW LOW VSBYS NEAR UPSLOPE REGION. WILL KEEP WINTER STORM WARNING GOING FOR NOW. HI RES 3/4 KM MODELS KEEP UPSLOPE SNOW GOING THROUGH THIS AFTERNOON. LATEST SOUNDINGS SHOW LOWERING OF THE INVERSION HEIGHT AT PIE/EKN SITES DURING THE MID- LATE AFTERNOON HOURS...INDICATIVE OF SNOW TAPERING OFF. TEMPS SLOWLY RISING ACROSS THE REGION. 12Z/IAD SOUNDING SHOWED 850 HPA TEMPERATURE OF -18.1C. LOCAL STUDY SHOWS WHEN THE 12Z/IAD SOUNDING IS -18...OBS SFC TEMPS NEVER MAKE IT OUT OF THE MID 30S. MADE SOME TWEEKS TO THE TEMPS FOR THIS AFTERNOON BASED ON RAOB. CANCELLED THE WIND CHILL ADVISORY FOR THE FAR WESTERN ZNS AS WINDS HAVE ABATED SOMEWHAT AS TEMPS SLOWLY RISE OUT THERE. ADJUSTED SKY COVER GRIDS BASED ON COMBINATION OF LATEST SAT AND 12KM RUC FORECASTS. PREVIOUS DISCUSSIONS FOLLOWS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... MONDAY...A HIGH PRESSURE CENTER CROSSES THE SERN CONUS AS THE UPPER TROUGH OVER THE ERN CONUS LIFTS NORTH. WARMING TREND BEGINS AS THE NORTHERN STREAM LOSES INFLUENCE OVER THE MID ATLANTIC. MAX TEMPS LOW TO MID 40S IN DOWNSLOPING WLY FLOW /STILL GUSTY TO AROUND 25 MPH IN THE MORNING/. MOSTLY SUNNY IN THE MORNING...WITH HIGH CLOUDS THICKENING THROUGH THE AFTERNOON FROM THE WEST. MONDAY NIGHT...WITH INCREASING CLOUDS AHEAD OF A SHORTWAVE AND SWLY FLOW...WENT ABOVE MEX GUIDANCE FOR MINS...UPR 20S TO AROUND 30F INLAND...LOW 30S I-95 AND EAST. TUESDAY...UPPER SHORTWAVE TROUGH PASSES FROM THE WEST WITH PASSING SHOWERS. SNOW POSSIBLE UP ON THE RIDGES...OTHERWISE PROFILES ARE WARM ENOUGH FOR RAIN. MAX TEMPS MID TO UPR 40S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE AND CONTINUED WARMING THROUGH THE MIDDLE PART OF THE WEEK. MAX TEMPS INTO THE 50S FOR WEDNESDAY AND THURSDAY. 00Z GFS/ECMWF CONSENSUS ON THE SFC LOW OF A SYSTEM PASSING LATE THURSDAY TO BE NORTH OF LWX. THEREFORE...CURRENT EXPECTATION IS FOR RAIN. WILL NEED TO MONITOR THIS LOW AS IT PASSES. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS EXPECTED TODAY. WINDS GUSTING TO 30 KT AT TIMES FROM 290-320. WINDS GRADUALLY BECOME MORE WESTERLY BY EARLY EVENING BUT CONTINUED GUSTY. THERE IS A POTENTIAL FOR DECOUPLING OF THE WINDS THIS EVENING. VFR MONDAY/MONDAY NIGHT AS GUSTY NWLY FLOW SLOWLY SLACKENS AND BECOME WLY AS HIGH PRESSURE PASSES TO THE SOUTH. PASSING RAIN SHOWERS TUESDAY/TUESDAY NIGHT FROM A WEAK UPPER TROUGH...BEFORE MORE HIGH PRESSURE THROUGH MIDWEEK. A STRONGER STORM SYSTEM LOOKS TO CROSS THE MID ATLANTIC LATE THURSDAY. && .MARINE... WILL KEEP WNWLY GALES ACROSS THE WATERS TODAY. MODEL GUIDANCE CONSENSUS OVERNIGHT WAS FOR A LULL IN GALES UNTIL THE LATE AFTERNOON/EVENING BEFORE ANOTHER ROUND OF GALES THIS EVENING. WILL CONTINUE TO EVALUATE THIS THINKING BUT WILL LEAVE IT UP FOR NOW UNTIL NEW GUIDANCE SAYS OTHERWISE. THEN SMALL CRAFT ADVISORIES ARE IN EFFECT THROUGH MONDAY MORNING AS HIGH PRESSURE BUILDS TO THE SOUTH. A WEAK UPPER TROUGH MOVES THROUGH TUESDAY...BRINGING RAIN SHOWERS TO THE CHESAPEAKE BAY REGION AND SLY FLOW AROUND 15 KT /MAY SEE SOME GUSTS AROUND 18 KT/. MORE HIGH PRESSURE AROUND MID WEEK. THE NEXT STORM SYSTEM THEN CROSSES THE WATERS LATE THURSDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ501. VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR VAZ503. WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR WVZ501- 503-505. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST MONDAY FOR ANZ530>543. GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR ANZ530>543. && $$ SYNOPSIS...SMZ NEAR TERM...SMZ SHORT TERM...BAJ LONG TERM...BAJ/NWL AVIATION...SMZ MARINE...SMZ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
911 AM EST SUN FEB 12 2012 .SYNOPSIS... COLD BLUSTERY WESTERLY WINDS WILL MAINTAIN SNOW SHOWERS AND BLOWING SNOW ACROSS THE UPPER OHIO VALLEY TODAY. MIDWEST HIGH PRESSURE WILL PROVIDE MODERATING TEMPERATURES AND DRY WEATHER MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PER BLEND OF RECENT SURFACE AND RADAR DATA, COUPLED WITH RECENT HRRR MODEL OUTPUT, EXPECT A PASSING TROUGH ALOFT TO MAINTAIN NUMEROUS SNOW SHOWERS AND AREAS OF BLOWING SNOW EAST OF I-77 CORRIDOR INTO EARLY AFTERNOON. NAM MODEL PROFILES SHOW A LOWERING SUBSIDENCE INVERSION THIS AFTERNOON, WHICH SHOULD CAP THE LAKE-MOISTURE- ENHANCED INSTABILITY, AND WEAKEN THE SNOW SHOWERS DURING THE AFTERNOON. HRRR AND WRF-NMM SIMULATED RADAR OUTPUT LIKEWISE SHOWS A MARKED DECREASE IN SNOW SHOWER COVERAGE BY LATE AFTERNOON. ITS HARD TO JUDGE HOW MUCH ADDITIONAL SNOW ACCUMULATION DUE TO THE WIND AND BLOWING SNOW, BUT GENERALLY EXPECT 1 INCH ADDITIONAL SNOWFALL TODAY, WITH UP TO 3 INCHES ACROSS THE HIGHER MOUNTAINS. HENCE WILL MAINTAIN THE CURRENT WINTER WEATHER HEADLINES THROUGH MIDDAY. SPECIFIC TEMPERATURES, WINDS, AND GUSTS WERE BASED ON BLEND OF RECENT GFS LAMP, HRRR, AND NAM MODEL OUTPUT. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... PER NAM MODEL OUTPUT, EXPECT THE CAPPING SUBSIDENCE INVERSION TO FURTHER LOWER AND STRENGTHEN TONIGHT, ENDING THE SNOW SHOWERS AND DECREASING CLOUD COVER. RADIATIONAL COOLING OVER THE FRESH SNOW PACK WILL PROVIDE LOW TEMPERATURES TONIGHT SIMILAR TO SATURDAY NIGHT. AS HIGH PRESSURE BUILDS EAST FROM THE MIDWEST, EXPECT WARMER TEMPERATURES ALOFT TO HELP BOOST AFTERNOON SURFACE TEMPERATURES TO YIELD HIGHS CLOSE TO THE FREEZING MARK MONDAY AFTERNOON. MODELS THEN SHOW A WEAK LOW PRESSURE SYSTEM, COMING EAST FROM THE PLAINS TO PROVIDE SNOW SHOWERS TUESDAY, WITH TEMPERATURES TUESDAY AFTERNOON MILDER THEN PREVIOUS DAYS BUT STILL ABOUT 5 DEGREES COLDER THAN NORMAL. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... GENERALLY FOLLOWED EC AND HPC GUIDANCE. HIGH PRESSURE ACROSS REGION WEDNESDAY WITH FAIR WEATHER. MODELS CONTINUE TO STRUGGLE WITH STRENGTH OF LOW PRESSURE MOVING THROUGH OHIO RIVER VALLEY ON THURSDAY...BUT EXPECT MOSTLY RAIN ON THURSDAY WITH SOME SNOW POSSIBLE ACROSS FAR NORTH. BY FRIDAY SYSTEM IS WELL EAST OF AREA WITH CHANCE OF SNOW SHOWERS IN NORTHWEST FLOW. HIGH PRESSURE REMAINS WEST OF REGION WITH NORTHWEST FLOW. THIS SHOULD KEEP SOME CLOUDINESS OF REGION...BUT LACK OF COLD AIR PRECLUDES SNOW SHOWER ACTIVITY SATURDAY. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... NW FLOW ACROSS THE GREAT LAKES WILL CONTINUE TO GENERATE MVFR STRATOCUMULUS AND SNOW SHOWERS OVER THE REGION TODAY. A SHORT WAVE TROUGH WILL CROSS THE REGION LATE THIS MORNING...PROVIDING EXTRA LIFT AND MOISTURE TO ENHANCE LAKE EFFECT SNOW SHOWERS. IFR RESTRICTIONS CAN BE EXPECTED IN HEAVIER SNOW SHOWERS MAINLY AT WESTERN PA TERMINALS THROUGH MIDDAY. SURFACE WINDS WILL GUST TO 25 KT AT TIMES CAUSING BLOWING SNOW. DURING THE AFTERNOON...LOWERING SUBSIDENCE INVERSION WILL LIMIT THE MIXING LAYER...BUT CONVECTION SHOULD STILL GENERATE SOME MVFR CEILINGS FOR MOST TERMINALS. OVERALL IMPROVEMENT TO VFR CONDITIONS AND REDUCED WIND GUSTS CAN BE EXPECTED BY LATE AFTERNOON. OUTLOOK...MONDAY THROUGH THURSDAY... BUILDING HIGH PRESSURE WILL RETURN VFR CONDITIONS FOR MONDAY. A SHORTWAVE IN ZONAL FLOW IS PROGGED TO GENERATE MORE LIGHT SNOW BY EARLY TUESDAY. MVFR RESTRICTIONS CAN BE EXPECTED WITH THAT SYSTEM. REBUILDING HIGH PRESSURE WILL BRING A BRIEF RETURN TO VFR FOR MIDWEEK. A STRONGER LOW IS PROGGED TO MOVE TOWARD THE REGION ON THURSDAY AND WILL GENERATE THE POTENTIAL FOR RESTRICTIONS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR MDZ001. WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR MDZ001. OH...NONE. PA...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR PAZ007>009-013>016-020>023-073-075. WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR PAZ074- 076. WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR PAZ074-076. WV...WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR WVZ023- 041. WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR WVZ023-041. && $$
AREA FORECAST DISCUSSION...UPDATE
NWS JACKSON MS
915 AM CST SUN FEB 12 2012 .UPDATE...CHILLY HIGH PRESSURE CENTERED RIGHT ACROSS THE MIDDLE AND LOWER MISSISSIPPI VALLEYS TODAY WILL WORK TO HOLD BACK MOST OF THE ENCROACHING CLOUDS AHEAD OF THE NEXT SYSTEM UNTIL TONIGHT. GENERALLY LIGHT NORTH TO NORTHEAST WINDS WILL PREVAIL TODAY...WHICH IS GOOD CONSIDERING THE VERY DRY AIR MASS MIGHT OTHERWISE PROMOTE AN ELEVATED FIRE DANGER IF THE WINDS WERE ON PAR WITH YESTERDAY. TEMPERATURES AT 9 AM WERE STILL AT OR A LITTLE BELOW FREEZING IN MOST AREAS...BUT WILL SOLIDLY GET ABOVE FREEZING IN THE NEXT HOUR OR TWO. PREVIOUSLY FORECASTED HIGHS RANGING LOWER 40S IN THE NORTH TO THE UPPER 40S IN THE SOUTH LOOK GOOD AT THIS POINT AND THE ONLY ADJUSTMENTS FOR THIS UPDATE WERE TO HOURLY TRENDS. /BB/ && .PREV DISCUSSION... /ISSUED 401 AM CST SUN FEB 12 2012/ SHORT TERM...TODAY THROUGH MONDAY NIGHT...IT IS A CHILLY MORNING ACROSS THE ARKLAMISS WITH TEMPERATURES IN THE 20S AREAWIDE. SOME LOCATIONS HAVE BEEN ABLE TO DIP INTO THE LOWER 20S AND TEENS. A BRISK NORTH WIND CONTINUES WHICH IS ALLOWING WIND CHILLS TO BE IN THE TEENS AND LOWER 20S. COMPARED TO THIS TIME 24 HOURS AGO...WE ARE ABOUT 15 TO 20 DEGREES COLDER. BASED ON RUC ANALYSIS...THE CENTER OF THE SFC HIGH IS LOCATED JUST SOUTH OF TULSA BUT THE NORTH-SOUTH AXIS OF THE SFC HIGH IS QUITE EXPANSIVE...RANGING FROM SOUTHERN CANADA TO THE GULF OF MEXICO. THE SFC HIGH WILL SHIFT ACROSS THE MID TO LOWER MISSISSIPPI VALLEY REGION THROUGH THE DAY TODAY AND SHORTWAVE RIDGING WILL MOVE OVERHEAD. THIS...COUPLED WITH THE PLENTY OF INSOLATION AND LESS BRISK WINDS AS YESTERDAY...WE SHOULD WARM UP BETTER THAN YESTERDAY. WHILE LOCATIONS GENERALLY ALONG AND SOUTH OF I-20 WERE ABLE TO REACH INTO THE LOWER 40S YESTERDAY AFTERNOON...ALL LOCATIONS SHOULD BE ABLE TO GET INTO THE 40S TODAY. AFTERNOON HIGHS EXPECTED TO RANGE FROM THE LOWER 40S NORTH TO THE UPPER 40S/AROUND 50 SOUTH. SOUTHERLY FLOW WILL RESUME BY THIS EVENING INTO TONIGHT...ALLOWING FOR MOISTURE TO SLOWLY INCREASE BACK INTO THE REGION AND BEGIN SOME WAA BACK INTO THE REGION. CLOUDS WILL SLOWLY MOVE BACK INTO THE REGION AND OVERNIGHT LOWS WILL BE WARMING BUT WILL STILL BE ON THE CHILLY SIDE AS THE COLDEST AIRMASS THIS YEAR DEPARTS. READINGS WILL RANGE FROM THE UPPER 20S/LOWER 30S WEST TO A CHILLIER LOWER TO MID 20S IN THE EAST...CLOSEST TO THE SFC HIGH. BY SUNRISE MONDAY...WE SHOULD BE FAIRLY WELL SHROUDED IN CLOUDS. IT WILL BE SLOW TO WARM DUE TO THE EXTENSIVE CLOUD COVER BUT ALSO PRECIP WILL BE DEVELOPING JUST TO THE WEST OF THE REGION. MODELS ARE A LITTLE DIFFERENT IN THE TIMING OF THE ONSET OF PRECIP BUT OVERALL...WE SHOULD BE SEEING SOME ONSET OF PRECIP BY MID MORNING. THERE REMAINS SOME POTENTIAL FOR A WINTRY MIX OF PRECIP AT THE ONSET. MODEL SOUNDINGS SHOW A MOIST LAYER IN THE MID LEVELS WITH DRIER LOWER LEVELS. AS THE RAIN FALLS THROUGH THIS AND EVAPORATES...THERE SHOULD BE SOME COOLING WHICH WILL ALLOW THE PRECIP THAT REACHES THE GROUND TO BE A MIX OF LIGHT SNOW AND OR LIGHT SLEET. AS THE MORNING WEARS ON INTO THE AFTERNOON...THIS SHOULD BE MORE OF RAIN/SLEET MIX BEFORE THE ATMOSPHERE MOISTENS THROUGHOUT THE COLUMN AND WARMS...THUS ENDING WITH ALL RAIN BY THE AFTERNOON AND EVENING HOURS. THE MOST LIKELY LOCATIONS FOR WINTRY MIX TO OCCUR WILL BE NORTH OF I-20. GIVEN THE WARMER GROUND TEMPS AND LIGHT NATURE OF THIS PRECIP...NOT EXPECTING THIS TO ACCUMULATE OR CAUSE TRAVEL OR ROAD ISSUES. RAIN WILL CONTINUE MONDAY NIGHT AS THE UPPER TROUGH TRAVERSES NORTH OF THE REGION. LIFT APPEARS TO BE JUST ENOUGH LATE MONDAY AFTERNOON INTO THE EVENING FOR THERE TO BE PERHAPS TO BE SOME MODERATE RAIN BUT OVERALL THE RAIN SHOULD TURN LIGHTER AS THE NIGHT PROGRESSES. TEMPERATURES MONDAY NIGHT WILL REMAIN WARM ENOUGH TO DISMISS ANY WINTRY PRECIP ISSUES WITH READINGS IN THE UPPER 30S TO LOWER/MID 40S. MAIN ADJUSTMENTS TO THE GUI WERE TO CUT HIGH TEMPS MONDAY AS MAV GUI CONTINUES TO COME IN ON THE HIGHER SIDE. GIVEN TOP DOWN MOISTENING OF THE ATMOSPHERE...CLOUDS AND RAINFALL...CANT SEE TEMPS GETTING TOO WARM. ALSO RAISED POPS IN THE DELTA FOR MONDAY AS THIS AREA LOOKS TO BE MOST FAVORABLE FOR RAINFALL. /28/ LONG TERM...TUESDAY THROUGH SUNDAY...THE FOCUS OF THIS PERIOD WILL BE ON THE SYSTEM FOR MID WEEK WHICH WILL BRING RAIN/STORMS TO THE REGION. OUTSIDE THAT...NO MAJOR TEMP SWINGS ARE EXPECTED WITH GENERALLY CLIMO TYPE (OR SLGT ABV) CONDITIONS EXPECTED. FOR TUE...LOOK FOR SOME LGT PRECIP LINGERING ACROSS THE E HALF TO START THE PERIOD...BUT THIS WILL SHIFT EAST EARLY AND I EXPECT THE PRECIP TO BE OUT OF THE AREA BY 9 AM. WHAT WILL LINGER MOST OF THE DAY WILL BE LOW CLOUDS. LATEST GUID DATA INDICATES THIS AND THERE WILL BE AN IMPACT ON TEMPS. THE GFS IS THE OUTLIER AND THE WARMEST OF THE GUID. FOR THIS FORECAST...THE EURO/NAM TEMPS WERE USED. FOR I-20 AND NORTH...52-60 DEGREES WILL BE THE RANGE. FURTHER SOUTH...LESS CLOUD POTENTIAL WILL OFFER A BETTER OPPORTUNITY TO WARM...HIGHS MAY PUSH 70 NEAR HBG. FOR WED...THE ATMOSPHERE LOOKS TO TRANSITION QUICKLY TO A WAA REGIME AND MOISTENING WILL OCCUR WITH RAIN/STORM DEVELOPING BY AFTERNOON INTO WED NGT. THE EURO HAS BEEN VERY CONSISTENT WITH THIS SYSTEM BOTH IN TIMING/INTENSITY. AT THIS TIME...NOT EXPECTING ANY SVR WEATHER...BUT A FEW STRONG STORMS APPEAR POSSIBLE IF THE EURO VERIFIES. THE GFS BRINGS PRECIP IN SLOWER...BUT MOVES THINGS OUT QUICKER EARLY THU. THE GFS HAS LESS POTENTIAL FOR STRONG ACTIVITY AND OFFERS MORE OF A RAIN/FEW TSRA SCENARIO. AS MENTIONED...FOLLOWING THE EURO ON THIS ONE BUT WILL NOT MENTION ANY STRONG STORM RISK AT THIS TIME DUE TO UNCERTAINTY BUT WE WILL KEEP AN EYE ON ANY CHANGES AND ADD A RISK IF CONFIDENCE INCREASES. TEMPS FOR WED WERE LOWERED MORE IN LINE WITH THE EURO/GFS ENSEMBLE AS THE OPS GFS WAS THE HIGH MEMBER...MAINLY BECAUSE IT IS THE SLOWER SOLUTION. ADDITIONALLY...LOW TEMPS WERE RAISED WED NGT AS HIGHER LOW LEVEL MOISTURE WILL BE IN PLACE. I WAS CONSERVATIVE WITH LOWS THIS PERIOD AND STAYED IN THE 50S. HOWEVER...IT COULD BE SEVERAL DEGREES WARMER IF THE LOWER/MID 60 DEWPTS ARRIVE LIKE THE EURO SUGGESTS. THE REST OF THE EXTENDED LOOKS TO GENERALLY BE QUIET...THERE ARE DIFFERENCES IN THE GFS/EURO FOR SUNDAY. THE GFS IS WET WHILE THE EURO DRY. FOR NOW...WILL JUST FOLLOW THE GFS...BUT I EXPECT THE EURO TO BE MORE CORRECT. GUID TEMPS WERE FOLLOWED FOR THIS PERIOD AS WELL. THE EXCEPTION WAS SAT MORNING. READINGS WERE WARMED TO MORE OF A BLEND OF THE EURO/GFS ENSEMBLE. THE OPS GFS WAS ODDLY VERY COLD AND LOWS WERE WARMED A DECENT AMOUNT. /CME/ && .AVIATION...VFR CONDITIONS WILL CONTINUE ACROSS THE REGION TODAY. DECKS OF HIGH CLOUDS WILL MOVE ACROSS THE AREA WITH N/NE WINDS FROM 5-10KTS. CLOUD COVER WILL INCREASE AND LOWER FOR TONIGHT AS MOISTURE INCREASES OVER THE AREA BUT CEILINGS ARE EXPECTED TO REMAIN ABOVE 8KFT. WINDS WILL SHIFT TONIGHT OUT OF THE SOUTHEAST AROUND 3-5KTS. /28/03/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 46 25 51 41 / 0 6 56 86 MERIDIAN 47 22 52 41 / 0 3 36 86 VICKSBURG 45 27 50 42 / 0 11 76 82 HATTIESBURG 51 22 55 48 / 0 5 30 82 NATCHEZ 45 29 55 45 / 0 11 68 81 GREENVILLE 41 26 42 39 / 0 11 86 79 GREENWOOD 42 26 42 38 / 0 6 81 88 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ BB/03/28/CME
AREA FORECAST DISCUSSION
NWS JACKSON MS
401 AM CST SUN FEB 12 2012 .SHORT TERM...TODAY THROUGH MONDAY NIGHT...IT IS A CHILLY MORNING ACROSS THE ARKLAMISS WITH TEMPERATURES IN THE 20S AREAWIDE. SOME LOCATIONS HAVE BEEN ABLE TO DIP INTO THE LOWER 20S AND TEENS. A BRISK NORTH WIND CONTINUES WHICH IS ALLOWING WIND CHILLS TO BE IN THE TEENS AND LOWER 20S. COMPARED TO THIS TIME 24 HOURS AGO...WE ARE ABOUT 15 TO 20 DEGREES COLDER. BASED ON RUC ANALYSIS...THE CENTER OF THE SFC HIGH IS LOCATED JUST SOUTH OF TULSA BUT THE NORTH-SOUTH AXIS OF THE SFC HIGH IS QUITE EXPANSIVE...RANGING FROM SOUTHERN CANADA TO THE GULF OF MEXICO. THE SFC HIGH WILL SHIFT ACROSS THE MID TO LOWER MISSISSIPPI VALLEY REGION THROUGH THE DAY TODAY AND SHORTWAVE RIDGING WILL MOVE OVERHEAD. THIS...COUPLED WITH THE PLENTY OF INSOLATION AND LESS BRISK WINDS AS YESTERDAY...WE SHOULD WARM UP BETTER THAN YESTERDAY. WHILE LOCATIONS GENERALLY ALONG AND SOUTH OF I-20 WERE ABLE TO REACH INTO THE LOWER 40S YESTERDAY AFTERNOON...ALL LOCATIONS SHOULD BE ABLE TO GET INTO THE 40S TODAY. AFTERNOON HIGHS EXPECTED TO RANGE FROM THE LOWER 40S NORTH TO THE UPPER 40S/AROUND 50 SOUTH. SOUTHERLY FLOW WILL RESUME BY THIS EVENING INTO TONIGHT...ALLOWING FOR MOISTURE TO SLOWLY INCREASE BACK INTO THE REGION AND BEGIN SOME WAA BACK INTO THE REGION. CLOUDS WILL SLOWLY MOVE BACK INTO THE REGION AND OVERNIGHT LOWS WILL BE WARMING BUT WILL STILL BE ON THE CHILLY SIDE AS THE COLDEST AIRMASS THIS YEAR DEPARTS. READINGS WILL RANGE FROM THE UPPER 20S/LOWER 30S WEST TO A CHILLIER LOWER TO MID 20S IN THE EAST...CLOSEST TO THE SFC HIGH. BY SUNRISE MONDAY...WE SHOULD BE FAIRLY WELL SHROUDED IN CLOUDS. IT WILL BE SLOW TO WARM DUE TO THE EXTENSIVE CLOUD COVER BUT ALSO PRECIP WILL BE DEVELOPING JUST TO THE WEST OF THE REGION. MODELS ARE A LITTLE DIFFERENT IN THE TIMING OF THE ONSET OF PRECIP BUT OVERALL...WE SHOULD BE SEEING SOME ONSET OF PRECIP BY MID MORNING. THERE REMAINS SOME POTENTIAL FOR A WINTRY MIX OF PRECIP AT THE ONSET. MODEL SOUNDINGS SHOW A MOIST LAYER IN THE MID LEVELS WITH DRIER LOWER LEVELS. AS THE RAIN FALLS THROUGH THIS AND EVAPORATES...THERE SHOULD BE SOME COOLING WHICH WILL ALLOW THE PRECIP THAT REACHES THE GROUND TO BE A MIX OF LIGHT SNOW AND OR LIGHT SLEET. AS THE MORNING WEARS ON INTO THE AFTERNOON...THIS SHOULD BE MORE OF RAIN/SLEET MIX BEFORE THE ATMOSPHERE MOISTENS THROUGHOUT THE COLUMN AND WARMS...THUS ENDING WITH ALL RAIN BY THE AFTERNOON AND EVENING HOURS. THE MOST LIKELY LOCATIONS FOR WINTRY MIX TO OCCUR WILL BE NORTH OF I-20. GIVEN THE WARMER GROUND TEMPS AND LIGHT NATURE OF THIS PRECIP...NOT EXPECTING THIS TO ACCUMULATE OR CAUSE TRAVEL OR ROAD ISSUES. RAIN WILL CONTINUE MONDAY NIGHT AS THE UPPER TROUGH TRAVERSES NORTH OF THE REGION. LIFT APPEARS TO BE JUST ENOUGH LATE MONDAY AFTERNOON INTO THE EVENING FOR THERE TO BE PERHAPS TO BE SOME MODERATE RAIN BUT OVERALL THE RAIN SHOULD TURN LIGHTER AS THE NIGHT PROGRESSES. TEMPERATURES MONDAY NIGHT WILL REMAIN WARM ENOUGH TO DISMISS ANY WINTRY PRECIP ISSUES WITH READINGS IN THE UPPER 30S TO LOWER/MID 40S. MAIN ADJUSTMENTS TO THE GUI WERE TO CUT HIGH TEMPS MONDAY AS MAV GUI CONTINUES TO COME IN ON THE HIGHER SIDE. GIVEN TOP DOWN MOISTENING OF THE ATMOSPHERE...CLOUDS AND RAINFALL...CANT SEE TEMPS GETTING TOO WARM. ALSO RAISED POPS IN THE DELTA FOR MONDAY AS THIS AREA LOOKS TO BE MOST FAVORABLE FOR RAINFALL. /28/ .LONG TERM...TUESDAY THROUGH SUNDAY...THE FOCUS OF THIS PERIOD WILL BE ON THE SYSTEM FOR MID WEEK WHICH WILL BRING RAIN/STORMS TO THE REGION. OUTSIDE THAT...NO MAJOR TEMP SWINGS ARE EXPECTED WITH GENERALLY CLIMO TYPE (OR SLGT ABV) CONDITIONS EXPECTED. FOR TUE...LOOK FOR SOME LGT PRECIP LINGERING ACROSS THE E HALF TO START THE PERIOD...BUT THIS WILL SHIFT EAST EARLY AND I EXPECT THE PRECIP TO BE OUT OF THE AREA BY 9 AM. WHAT WILL LINGER MOST OF THE DAY WILL BE LOW CLOUDS. LATEST GUID DATA INDICATES THIS AND THERE WILL BE AN IMPACT ON TEMPS. THE GFS IS THE OUTLIER AND THE WARMEST OF THE GUID. FOR THIS FORECAST...THE EURO/NAM TEMPS WERE USED. FOR I-20 AND NORTH...52-60 DEGREES WILL BE THE RANGE. FURTHER SOUTH...LESS CLOUD POTENTIAL WILL OFFER A BETTER OPPORTUNITY TO WARM...HIGHS MAY PUSH 70 NEAR HBG. FOR WED...THE ATMOSPHERE LOOKS TO TRANSITION QUICKLY TO A WAA REGIME AND MOISTENING WILL OCCUR WITH RAIN/STORM DEVELOPING BY AFTERNOON INTO WED NGT. THE EURO HAS BEEN VERY CONSISTENT WITH THIS SYSTEM BOTH IN TIMING/INTENSITY. AT THIS TIME...NOT EXPECTING ANY SVR WEATHER...BUT A FEW STRONG STORMS APPEAR POSSIBLE IF THE EURO VERIFIES. THE GFS BRINGS PRECIP IN SLOWER...BUT MOVES THINGS OUT QUICKER EARLY THU. THE GFS HAS LESS POTENTIAL FOR STRONG ACTIVITY AND OFFERS MORE OF A RAIN/FEW TSRA SCENARIO. AS MENTIONED...FOLLOWING THE EURO ON THIS ONE BUT WILL NOT MENTION ANY STRONG STORM RISK AT THIS TIME DUE TO UNCERTAINTY BUT WE WILL KEEP AN EYE ON ANY CHANGES AND ADD A RISK IF CONFIDENCE INCREASES. TEMPS FOR WED WERE LOWERED MORE IN LINE WITH THE EURO/GFS ENSEMBLE AS THE OPS GFS WAS THE HIGH MEMBER...MAINLY BECAUSE IT IS THE SLOWER SOLUTION. ADDITIONALLY...LOW TEMPS WERE RAISED WED NGT AS HIGHER LOW LEVEL MOISTURE WILL BE IN PLACE. I WAS CONSERVATIVE WITH LOWS THIS PERIOD AND STAYED IN THE 50S. HOWEVER...IT COULD BE SEVERAL DEGREES WARMER IF THE LOWER/MID 60 DEWPTS ARRIVE LIKE THE EURO SUGGESTS. THE REST OF THE EXTENDED LOOKS TO GENERALLY BE QUIET...THERE ARE DIFFERENCES IN THE GFS/EURO FOR SUNDAY. THE GFS IS WET WHILE THE EURO DRY. FOR NOW...WILL JUST FOLLOW THE GFS...BUT I EXPECT THE EURO TO BE MORE CORRECT. GUID TEMPS WERE FOLLOWED FOR THIS PERIOD AS WELL. THE EXCEPTION WAS SAT MORNING. READINGS WERE WARMED TO MORE OF A BLEND OF THE EURO/GFS ENSEMBLE. THE OPS GFS WAS ODDLY VERY COLD AND LOWS WERE WARMED A DECENT AMOUNT. /CME/ && .AVIATION...HIGH CLOUDS STARTING TO STREAM INTO THE REGION AND THIS WILL CONTINUE THROUGH THE DAY. VFR CONDITIONS EXPECTED TO CONTINUE THROUGH TONIGHT. NORTH WINDS WILL CONTINUE BUT SPEEDS WILL BE AROUND 5-10KTS. CLOUD COVER WILL INCREASE AND LOWER FOR TONIGHT AS MOISTURE INCREASES OVER THE AREA BUT CEILINGS EXPECTED TO REMAIN ABOVE 8KFT. WINDS WILL SHIFT TONIGHT OUT OF THE SOUTHEAST AROUND 3-5KTS. /28/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 46 25 51 41 / 0 6 56 86 MERIDIAN 47 22 52 41 / 0 3 36 86 VICKSBURG 45 27 50 42 / 0 11 76 82 HATTIESBURG 51 22 55 48 / 0 5 30 82 NATCHEZ 45 29 55 45 / 0 11 68 81 GREENVILLE 41 26 42 39 / 0 11 86 79 GREENWOOD 42 26 42 38 / 0 6 81 88 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 28/CME
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
911 PM CST MON FEB 13 2012 .UPDATE... ISSUED AT 910 PM CST MON FEB 13 2012 REVIEW OF 00Z NAM AND RUC DATA AS WELL AS OBSERVED DATA SHOWS DRIZZLE THREAT TO BE WITH US FOR A WHILE WITH MUCH OF THE MID AND HI LEVEL CLOUDS NOW STRIPPED AWAY LEAVING BEHIND EXPANSIVE LO CLOUD DECK. STILL NEED WEAK LIFT...WHICH WILL BE PROVIDED BY EITHER WEAK CYCLONIC FLOW OR TROF THAT WILL MOVE THRU LATE TONIGHT AND EARLY TUESDAY MORNING. TEMPS CURRENTLY AT OR BELOW FREEZING AT ALL LOCATIONS...AND DESPITE S SFC WNDS...ADVECTION THAT RESULTS IS NEUTRAL...SO WE SHOULD SEE NEAR STEADY TEMPS OVERNIGHT...TO KEEP THE DRIZZLE FREEZING ON EXPOSED AND/OR UNTREATED SURFACES. EXTENDED THE WSW WHICH WAS ALREADY IN EFFECT UNTIL MIDNIGHT... UNTIL 6AM. MAY NEED TO BE EXTENDED FURTHER BEYOND 12Z TUESDAY FOR PARTS OF THE ERN FA IF TROF IS SLOWER THAN ANTICIPATED. TES && .SHORT TERM... ISSUED AT 300 PM CST MON FEB 13 2012 (TONIGHT) FOCUS TONIGHT WILL BE THE ONGOING PRECIP ACROSS THE REGION. UPPER TROF CURRENTLY OVER NEB/KS REGION WILL MOVE THRU THE CWA TONIGHT BRINGING THE SN TO AN END. AS OF 19Z...FIRST BAND OF HEAVY PRECIP IS MOVING OUT OF CNTL MO AND INTO THE ERN PORTIONS OF MO AND IL. THIS IS EXPECTED TO BE THE BULK OF THE SN FOR THE NWRN THIRD OF THE CWA. MDLS STILL INDICATE ANOTHER S/W LIFTING NEWD LATE THIS AFTERNOON AND EARLY EVE RESULTING IN ANOTHER BAND OF HEAVIER SN FOR AREAS ROUGHLY ALONG AND E OF A LINE FROM VIH/STL/3LF. ONCE THE SN COMES TO AN END...STILL EXPECT PATCHY FZDZ TO LINGER FOR A COUPLE OF HRS AS THE DEEP CLOUD LAYER IS LOST. A LOT OF UNCERTAINTY REGARDING HOW LONG THE FZDZ WILL CONTINUE OVERNIGHT. HAVE KEPT MENTION OF FZDZ OVERNIGHT FOR NOW WITH UPDATES AS NEEDED. AS FOR TEMPS OVERNIGHT...HAVE A QUICK DROP IN TEMPS SHORTLY AFTER SUNSET. HOWEVER...EXPECT TEMPS TO REMAIN NEARLY STEADY OVERNIGHT GIVEN SLY FLOW AND AMPLE CLOUD COVER. TILLY && .LONG TERM... ISSUED AT 300 PM CST MON FEB 13 2012 (TUESDAY THROUGH MONDAY) IN THE WAKE OF TONIGHTS STORM SYSTEM...HEIGHTS WILL RISE ALOFT ON TUESDAY AND LOW LEVEL WAA WILL GET UNDERWAY IN ERNEST AS THE LOW LEVEL RIDGE PASSES TO THE EAST. NORMALLY THIS WOULD ALLOW FOR A SIGNIFICANT WARM-UP AS H85 TEMPS RISE ON THE ORDER OF +6 TO +8 DEGC. HOWEVER SIGNIFICANT LOW CLOUDS ARE EXPECTED TO BLANKET THE AREA AT THE START OF THE DAY AND THESE WILL GRADUALLY CLEAR WEST TO EAST. THIS TREND COMBINED WITH LIGHT SNOW COVER SHOULD KEEP TEMPS IN CHECK AND HAVE FAVORED HIGHS CLOSER TO THE COOLER MET GUIDANCE. THE NEXT BIG SYSTEM TO IMPACT THE AREA IS ON TRACK FOR WED/WED NIGHT AND IS CURRENTLY CENTERED IN CALIFORNIA. THE GUIDANCE IS IN GOOD AGREEMENT THAT THE UPPER TROF MOVING THROUGH THE GULF OF AK WILL BE THE KICKER AS IT DIGS SSEWD ALONG THE WEST COAST OVER THE NEXT 48H...EJECTING THE CALIFORNIA TROF THROUGH THE SOUTHERN ROCKIES AND INTO THE PLAINS ON WEDNESDAY AND THROUGH THE MID MS VALLEY ON WED NIGHT. THIS UPPER SYSTEM SHOULD WEAKEN AS IT MOVES THROUGH OUR AREA AS IT ENCOUNTERS INCREASINGLY CONFLUENT FLOW ALOFT. AFTER LOSING THE LOW CLOUDS ON TUESDAY...MID/HI CLOUDS WILL BEGIN TO SPREAD BACK INTO THE AREA ON TUESDAY NIGHT IN ADVANCE OF THE MIGRATING UPPER TROF. PRECIPITATION SHOULD BEGIN TO EVOLVE LATE TUESDAY NIGHT ACROSS THE PLAINS IN RESPONSE TO STRENGTHENING LOW LEVEL WAA AND MOISTURE TRANSPORT. AT THIS TIME I AM THINKING IT WILL HOLD OFF IN OUR CWA UNTIL AFTER 14-15Z...AT LEAST HOPING SO. IF IT STARTS EARLIER THERE COULD BE SOME AREAS WITH SUB-FREEZING SURFACE TEMPERATURES TO CONTEND WITH. BY AFTERNOON ON WEDNESDAY...THE COVERAGE OF RAIN SHOULD INCREASE DRAMATICALLY IN RESPONSE TO STRONG LOW LEVEL WAA AND CONTINUE MOISTURE TRANSPORT INTO THE AREA VIA A SSWLY LLJ...AND INCREASING LARGE SCALE ASCENT ASSOCIATED WITH THE UPPER TROF. SOUNDINGS AND MODEL DELTA THETAE PROGS SHOW THE DEVELOPMENT OF ELEVATED INSTABILITY AS MID LEVEL LAPSE RATES AOA 7 DEGC/KM SPREAD INTO THE AREA IN ADVANCE OF THE TROF AND OVERSPREAD THE WARMING/MOISTENING LOW LEVELS. THEREFORE I HAVE ADDED A CHANCE OF THUNDER FROM THE AFTERNOON INTO THE EVENING HOURS. THE RAIN SHOULD TAPER AFTER MIDNIGHT AS THE WARM CONVEYOR BELT MOVES EASTWARD IN ASSOCIATION WITH THE ADVANCING UPPER TROF. THE SPEED OF THIS SYSTEM VARIES IN SOME IN THE GUIDANCE...BUT ALL SUGGEST THE PRECIPITATION WILL BE OVER BY THE TIME ANY DEEPER COLD AIR ARRIVES IN ITS WAKE THAT WOULD SUPPORT SNOWFALL. THE WHOLE UPPER PATTERN IS SOMEWHAT PROGRESSIVE THURSDAY AND BEYOND. THE MODELS SHOW A SPLIT REGIME ON FRIDAY WITH A SOUTHERN STREAM UPPER LOW IN WEST TX AND DEEPER NORTHERN STREAM TROF FROM HUDSON BAY INTO THE GREAT LAKES. AFTER FRIDAY THE DETERMINISTIC MODELS AND ENSEMBLES/MEMBERS QUICKLY DIVERGE AND SHOW MUCH SPREAD SATURDAY THROUGH MONDAY. THIS LEADS LOW CONFIDENCE IN DETAILS...HOWEVER THE GENERAL TRENDS SHOW NO SIGNFICANT WEATHER SYSTEMS IN THIS TIME FRAME AND TEMPERATURES AT OR ABOVE AVERAGE. GLASS && .AVIATION... ISSUED AT 537 PM CST MON FEB 13 2012 LAST GASP OF THE SNOW STORM IS MOVING THROUGH THE BI-STATE AREA AT THIS TIME. IFR FLIGHT CONDITIONS IN LIGHT TO MODERATE SNOW WILL BE WIDE SPREAD...WITH A FEW AREAS OF INTERMITTENT 1/2-1/4SM IN HEAVY SNOW. SNOW SHOULD MOVE EAST OF THE REGION BY 04-06Z. UNFORTUNATELY...FREEZING DRIZZLE WITH CIGS AOB OVC005 WILL PREVAIL FOR MUCH OF THE REST OF THE NIGHT. SHOULD SEE CONDITIONS IMPROVE BY MID-LATE MORNING. SPECIFICS FOR KSTL... IFR FLIGHT CONDITIONS IN LIGHT TO MODERATE SNOW WILL PREVAIL FOR A FEW MORE HOURS THIS EVENING. UNFORTUNATELY...ONCE THE SNOW ENDS THERE WILL BE AREAS OF FREEZING DRIZZLE TO DEAL WITH FOR MUCH OF THE NIGHT. CIGS WILL LIKELY DRIFT DOWN TO NEAR ALTERNATE MINIMUMS...AND MAY GO BELOW THOUGH AM UNSURE OF THAT AT THIS TIME. SHOULD SEE FREEZING DRIZZLE END BEFORE SUNRISE AND FLIGHT CONDITIONS IMPROVE DURING THE MID-LATE MORNING. CARNEY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR AUDRAIN MO- BOONE MO-CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO- GASCONADE MO-IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO- OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. IL...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR ADAMS IL-BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL- JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL- MONTGOMERY IL-PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
522 PM CST MON FEB 13 2012 .AVIATION... 00Z TAFS FOR KOFK...KLNK AND KOMA. LINGERING CIGS BETWEEN FL015 AND FL025 WITH OCCASIONAL 2-4SM SNOWS WILL HOLD THROUGH ABOUT 06Z IN THE KOMA AREA...CLEARING THE KLNK AND KOFK AREAS BEFORE 04Z. A GRADUAL CLEARING TREND IS EXPECTED FROM WEST TO EAST OVERNIGHT...WITH THE CLEARING LINE FINALLY REACHING KOMA BY ABOUT 10Z. WITH CLEAR SKIES...LIGHT WINDS AND FRESH SNOW COVER...SOME MVFR FOG IS LIKELY AT ALL TAF SITES. BUT PATCHY IFR OR LIFR VSBYS ARE POSSIBLE BETWEEN 10Z AND 15Z. DERGAN && .PREV DISCUSSION... /ISSUED 302 PM CST MON FEB 13 2012/ SHORT TERM...TONIGHT THROUGH THURSDAY. REGIONAL MOSAIC 88D AND SATL PIX SHOWING NARROW LIGHT BAND SNOW THROUGH NORTHWEST IOWA/CENTRAL NEB/NORTH CENTRAL KS ASSOCIATED WITH UPPER DEFORMATION ZONE AND SUBTLE POCKET OF UPGLIDE. HIGH RES HRRR AND RUC SHOWING THAT SNOW ACTIVITY SHOW BE OUT OF THE CWA BY LATE THIS AFTERNOON. MODELS IN VERY GOOD AGREEMENT THAT LARGE SCALE FLOW WILL CONSIST OF A BROAD TROF PREVAILING ACROSS THE CONUS WITH SEVERAL EMBEDDED SHORTWAVE MIGRATING THROUGH. FOR OUR AREA...SHORTWAVE OF PARTICULAR INTEREST WAS CURRENTLY DIGGING DOWN THE WEST COAST AND SHOULD BOTTOM OUT OVER THE FOUR CORNERS REGION TUESDAY...THEN LIFT INTO THE CENTRAL PLAINS ON WEDNESDAY WITH DPVA INDUCING SURFACE CYCLOGENESIS IN TX PANHANDLE. MODELS ALSO ADVERTISE STOUT MOISTURE ADVECTION WRAPPING INTO THE SYSTEM. EXPECT AREAL COVERAGE OF PCPN WILL INCREASE AS IT EXPANDS NORTHWARD THROUGH THE DAY. GIVEN TRACK OF BEST DYNAMIC FORCING...HAVE HIGHEST POPS TO THE SOUTH. PCPN TYPE WILL BE HARD TO PIN DOWN. BUFKIT SHOWING LOW LEVEL THERMAL STRUCTURE IN FLUX WITH POSSIBLE MIX OF FREEZING RAIN/SNOW AT ONSET OF MORNING PCPN. SYSTEM IS PROGGED TO SWEEP THROUGH QUICKLY AND PCPN SHOULD BE COMING TO AN END WEDNESDAY EVENING. NO SIGNIFICANT SNOW ACCUMULATIONS EXPECTED. DEE LONG TERM...THURSDAY NIGHT THROUGH MONDAY. QUIET AND DRY CONDITIONS EXPECTED THROUGH THE WEEKEND DESPITE FAST/ACTIVE NWRLY FLOW THANKS TO LIMITED AVAILABLE MOISTURE. UPPER RIDGING BUILDS OVER THE AREA LATE IN THE WEEKEND WHICH SHOULD HELP TEMPS RISE INTO THE LOWER 40S. A POTENT MID LEVEL WAVE MOVING OUT OF THE SOUTHWEST IS FORECAST TO MOVE INTO THE REGION MONDAY INTO TUESDAY. STRENGTH AND TIMING ARE STILL UNRESOLVED BUT TEMPS EARLY IN THE SYSTEM LOOK WARM ENOUGH TO SUPPORT RAIN. KERN && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
151 PM EST SUN FEB 12 2012 .SYNOPSIS... ARCTIC AIR WILL CONTINUE TO SPILL SOUTHEAST INTO THE REGION TODAY. THE COLD AIR HAS CAUSED LAKE EFFECT SNOW SHOWERS AND FLURRIES, THAT WILL CONTINUE INTO MONDAY. A WEAK STORM WILL MOVE THROUGH LATE TUESDAY AND TUESDAY NIGHT WITH A WIDESPREAD LIGHT SNOW. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM... MAIN BAND OF LE SNOW OVER CAYUGA COUNTY ACROSS WRN CORTLAND AND ERN TOMPKINS TO BROOME AND TIOGA. HRRR SEEMS TO HAVE A GOOD HANDLE ON THE BAND AND BEGINS TO LFT IT NEWRD IN RESPONSE TO THE APRCHG ARCTIC FNT. THIS ALIGNS WITH CRNT RADAR TRENDS AND DVLPG WLY FLOW SHOW ON SFC OBS. HRRR ALSO SHOWS THE BAND ALONG THE LAKE SHORE DROPPING SWRD WITH THE FNT AND GIVING MUCH OF THE FCST AREA...ESP ALONG AND WEST OF I81...ANOTHER GOOD BURST OF SNOW IN THE NEXT FEW HRS. HAVE ADJUSTED THE CVRG AND INTENSITY OF THE LE FOR THIS UPDATE...ALONG WITH A FEW OTR MINOR TWEEKS. 4 AM UPDATE... COLD AIR MOVING INTO THE REGION HAS CONTINUED A GENERAL AREA OF LAKE EFFECT FLURRIES ACROSS THE CWA. A BAND OF LIGHT TO MODERATE SNOW IS COMING SOUTHEAST OFF OF LAKE CAYUGA. THIS NNW FLOW WILL SHIFT TO NW TODAY SO NOT EXPECTING THIS TO LAST BEYOND NOON. ANOTHER BAND IS CONTINUED TO GEORGIAN BAY INTO ROCHESTER. THIS SHOULD EXTEND FURTHER INLAND INTO THE FINGER LAKES THIS MORNING AND CONTINUE THIS AFTERNOON. LAKE EFFECT WILL BECOME HEAVIER ACROSS CENTRAL NEW YORK AS A SECONDARY COLD FRONT IN SE ONTARIO MOVES SOUTHEAST TODAY. EXPANDED THE LES ADVISORY TO INCLUDE YATES AND CHENANGO AS WELL AS TOMPKINS AND TIOGA FOR THE CAYUGA BAND. IN ADDITION A WIND CHILL ADVISORY CONTINUES FOR NORTHERN ONEIDA COUNTY THIS MORNING. WIND CHILLS RIGHT AROUND MINUS FIFTEEN F THERE. THIS AREA WILL WARM SLOWLY AS SEEN HERE. TEMPERATURES AND DEW POINTS ON THE RISE WITH THE ADDED MOISTURE AND CLOUDS. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... 4 AM UPDATE... LAKE EFFECT SNOW WILL CONTINUING TONIGHT INTO MONDAY. WAA STARTS SLOWLY WHILE THE NW FLOW SLOWLY SHIFT TO W. THIS EVENING SNOW SHOWERS WILL BE ACROSS MOST OF THE CWA WITH THE HEAVIEST ACROSS THE NORTHERN COUNTIES IN THE ADVISORY. CONNECTION TO GEORGIAN BAY SHOULD CONTINUE MOST OF THE NIGHT. BY MONDAY MORNING THE LAKE SNOW WILL BE OUT NE PA. THE FLOW WILL BE 290 INTO ONEIDA COUNTY. A LES ADVISORY MAY BE NEEDED FOR ONEIDA FOR TONIGHT INTO MONDAY. MONDAY UPPER LEVEL RIDGING AND WAA WILL QUICKEN. THE LOW LEVEL SLOW GOES TO THE SW ACROSS THE ENTIRE REGION BY TUESDAY MORNING. 850 WINDS ARE STILL WEST BUT TEMPERATURES NOT ENOUGH TO CREATE LAKE EFFECT SNOW MONDAY OVERNIGHT. TUESDAY TEMPERATURES BACK TO NORMAL. INCREASING CLOUDS WITH MAYBE A FLURRY LATE IN THE DAY. A WEAK COLD FRONT WILL MOVE THROUGH TUESDAY NIGHT. SOME LIGHT SNOW SHOWERS ARE EXPECTED WITH IT. MOISTURE AND FORCING ARE LACKING. THE JET STREAM AND SFC LOW REMAIN WELL SOUTH OF THE REGION. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 4AM UPDATE... ON THE LARGE-SCALE...MEDIUM RANGE MODELS (EC/GFS/CMC) CONTINUE TO AGREE FAIRLY WELL THIS CYCLE (00Z SUN)...THAT PACIFIC ORIGIN DISTURBANCES WILL ZIP ACROSS THE CONUS THIS PD IN A FAST ZONAL FLOW PATN...AND IMPACT NY/PA ABT EVERY 48 HRS...TRACKING UNDERNEATH A FLAT ERN CANADIAN TROUGH AND OVER THE TOP OF UPR RIDGING OFF THE SERN U.S. COAST. ALTHOUGH SOME HIGHER LAT BLOCKING DOES PRESENT ITSELF ACROSS THE N ATLANTIC FROM TIME TO TIME THIS PD...ITS OVERALL LACK OF PERSISTENCE SHOULD PRECLUDE ANY MAJOR STORMS FROM TAKING SHAPE FOR THE NERN U.S. IT APPEARS THAT ANY TRUE ARCTIC AIR MASSES WILL REMAIN N OF THE U.S./CANADIAN BORDER...ALLOWING TEMPS TO AVERAGE CLOSE TO SEASONAL NORMS FOR MID TO LATE FEB (HIGHS IN THE 30S AND 40S). OVERALL...VERY LTL CHANGE WAS MADE TO THE CURRENT SET OF GRIDS. IT STILL LOOKS LIKE FAST MOVING STORM SYSTEMS WILL BRING SHOTS OF -RA/-SN INTO WED...AGN TWDS THE END OF THE WEEK (LATE THU AND FRI)...AND POSSIBLY JUST BEYOND THE PD (SUN INTO MON). A GENERAL LACK OF VERY COLD AIR WILL LIMIT LAKE RESPONSES FOLLOWING ANY OF THESE SYSTEMS. 420 PM UPDATE...HPC GRIDS FORMED BASIS OF LONG TERM FORECAST...WHICH IS INITIALLY DOMINATED BY A SOUTHWEST FLOW THAT HAS BEEN QUITE FAMILIAR THIS WINTER...AND SO GENERALLY ABOVE NORMAL TEMPERATURES. HOWEVER...TOWARDS END OF THE PERIOD...THERE IS UNCERTAINTY AS TO HOW MUCH OF A TROUGH PATTERN COULD SET UP OVER THE NORTHEAST. SURFACE HIGH PRESSURE GRADUALLY TAKES CHARGE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THOUGH WARM AIR ADVECTION WAVE ALOFT PASSES THROUGH WITH A FAIR AMOUNT OF MOISTURE. I KEPT ONLY LOW CHANCE POPS IN TUESDAY NIGHT...BECAUSE OF UNCERTAINTY AS TO IF ANY PRECIPITATION CAN ACTUALLY REACH THE GROUND. IT MAY INDEED ONLY TURN OUT TO BE ONLY AN OVERCAST SKY. NEXT WAVE COMES LATE THURSDAY-FRIDAY...AS EITHER A NEGATIVELY TILTED COLD FRONT OR AN OCCLUDED FRONT. ECWMF PREFERS MORE OF AN INSTANT OCCLUSION SCENARIO AS OHIO VALLEY LOW APPROACHES WESTERN NY THURSDAY EVENING...BUT NEW LOW ALSO DEVELOPS AND STRENGTHENS OFFSHORE. THAT COULD POTENTIALLY YIELD A FAIR SYNOPTIC SNOW FOR THE AREA...YET WE COULD ALSO QUICKLY GET INTO DRY SLOT WHICH WOULD LIMIT AMOUNTS. GFS WAITS UNTIL WELL AFTER FRONT PASSES...BEFORE ANY COASTAL SURFACE REFLECTION OF NEW LOW BECOMES APPARENT. IN THIS CASE...PRECIPITATION WOULD BE MORE OF A QUICK SHOT...WITH MORE TIME FOR WARM AIR TO BE INVOLVED AHEAD OF THE FRONT...SO PRECIPITATION TYPE IS IN QUESTION. GIVEN ALL OF THESE UNCERTAINTIES...FIGURED MID CHANCE RANGE POPS OFFERED BY HPC SUFFICED WELL...AS IT LOOKS UNSETTLED AND WE JUST HAVE TO SORT OUT THE DETAILS IN COMING DAYS. GFS DOES BRING A BRIEF PIECE OF COLDER AIR IN BY NEXT SATURDAY...WITH DEEPER YET ALSO TEMPORARY UPPER TROUGH. I PLACED SOME CHANCE POPS IN CENTRAL NEW YORK FOR POSSIBLE LAKE EFFECT AT THAT TIME. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... 130 PM UPDATE...A BAND OF HEAVIER SNOW SQUALLS IS IN THE PROCESS OF CLEARING THE SOUTHERN TIER OF NY TERMINALS. SOME IFR VSBYS ARE STILL POSSIBLE FOR ANOTHER HOUR OR SO AT KELM AND KBGM. FARTHER SOUTH AT KAVP IF THE BAND HOLDS TOGETHER A BRIEF PERIOD OF IFR VSBYS ARE POSSIBLE BETWEEN 20Z AND 22Z. ELSEWHERE MAINLY VFR VSBYS IN LIGHT FLURRIES...WITH PERIODS OF MVFR CIGS. TOWARD EVENING AS THE FLOW BECOMES MORE ESTABLISHED...ANOTHER BAND OF LAKE EFFECT SNOW WILL SET UP ON A 300 DEGREE FLOW. INITIALLY THIS MAY PRODUCE SOME IFR VSBYS AT KITH AND KBGM...ALONG WITH KSYR...BUT ALL THREE TERMINALS MAY JUST BE ON THE EDGE OF THE ACTUAL BAND ITSELF. AFTER MIDNIGHT AS THE FLOWS BACKS JUST A BIT TOWARD THE WEST-NORTHWEST...KSYR AND KRME WILL BE THE TWO TERMINALS THAT WILL BE UNDER THE GUN FOR IFR AND LIFR VSBYS IN HEAVY LAKE EFFECT SNOW. IMPROVEMENT IS NOT EXPECTED HERE UNTIL NEAR DAYBREAK AT KSYR AND MID MONDAY MORNING AT KRME. ELSEWHERE...THE NORTHWEST FLOW ITSELF WILL PRODUCE PERIODS OF MVFR CIGS OVERNIGHT WITH KITH AND KBGM BEING THE MOST LIKELY TERMINALS FOR THIS TO OCCUR AND KELM BEING THE LEAST LIKELY. SLOW IMPROVEMENT TO VFR IS POSSIBLE BY MID-MONDAY MORNING. NORTHWEST WINDS AROUND 12 TO 15 KTS WITH GUSTS TO 25 KTS THROUGH THIS EVENING. OVERNIGHT NORTHWEST WINDS AROUND 12KTS...DIMINISHING TO UNDER 10 KTS MONDAY AFTERNOON. .OUTLOOK... TUE/WED...MVFR/IFR PSBL AT ALL TAF SITES IN LGT SNOW. THUR...VFR. FRI...MVFR POSSIBLE IN RAIN/SNOW. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST MONDAY FOR NYZ015>018- 025-036-044-045-055. && $$ SYNOPSIS...TAC NEAR TERM...DGM/TAC SHORT TERM...TAC LONG TERM...MLJ/MDP AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1245 PM EST SUN FEB 12 2012 .SYNOPSIS... MUCH COLDER AIR WILL CONTINUE TO POUR IN THE REGION THROUGH THE REMAINDER OF THE WEEKEND. SNOW AND LOCALIZED LAKE EFFECT SNOWS SOUTHEAST OF THE LAKES WILL CONTINUE THROUGH TONIGHT. ANY LINGERING SNOW SHOWERS SOUTHEAST OF THE LAKES MONDAY MORNING WILL END AS HIGH PRESSURE BUILDS INTO THE REGION. ANOTHER WEAK SYSTEM MAY BRING SOME LIGHT SNOW ON TUESDAY AS TEMPERATURES MODERATE TO A LITTLE ABOVE AVERAGE AGAIN. && .NEAR TERM /THROUGH TONIGHT/... BAND OF INTENSE LAKE SNOWS DROPPING SOUTH IMPACTING THE NIAGARA FALLS/BUFFALO AREAS OVER TO ROCHESTER LATE THIS MORNING. THIS BAND DROPPING SNOWFALL RATES UP TO TWO INCHES PER HOUR. THIS BAND WILL CONTINUE TO SINK SOUTHWARD BUT LIKELY WEAKEN SOMEWHAT AS IT MOVES AWAY FROM LAKE INFLUENCES...WHICH IS SUPPORTED BY LATEST HRRR. LATEST HRRR AND WRF SUGGESTING WEAKER MULTIPLE BANDS WILL CONTINUE TO IMPACT BOTH LAKES THROUGH THE AFTERNOON. LAKE SNOW HEADLINES WILL REMAIN INTACT WITH ADDITIONAL AMOUNTS THROUGH THIS AFTERNOON IN THE 2-4/3-5 INCH RANGE IN FAVORED NORTHWEST FLOW AREAS. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AT THE START OF THE PERIOD MONDAY MORNING A LAKE EFFECT BAND WILL STILL BE ONGOING SOUTHEAST OF LAKE ONTARIO. INSTABILITY WILL BE ON THE WANE...WITH LAKE INDUCED EQUILIBRIUM LEVELS AROUND 6K FEET. DESPITE THE WEAKENING INSTABILITY...STILL FAVORABLE SNOW GROWTH AND LONG FETCH SHOULD KEEP A DECENT BAND GOING MONDAY MORNING AS IT LIFTS ACROSS OSWEGO COUNTY TOWARD THE TUG HILL WITH A FEW INCHES POSSIBLE. BY MIDDAY LAKE INDUCED INSTABILITY BEGINS TO WEAKEN FURTHER...AND THAT COMBINED WITH DIMINISHING SYNOPTIC SCALE MOISTURE AND INCREASING SHEAR WILL BREAK THE BAND APART INTO SCATTERED SNOW SHOWERS ACROSS THE TUG HILL REGION...THEN END ALTOGETHER BY EARLY MONDAY EVENING. OFF LAKE ERIE EXPECT LAKE EFFECT TO BE OVER BY 12Z MONDAY. OTHERWISE MOST AREAS SHOULD SEE A DECENT AMOUNT OF SUNSHINE ON MONDAY OUTSIDE OF THE LAKE ONTARIO LAKE EFFECT. MODERATING AIRMASS SHOULD BRING HIGHS BACK VERY CLOSE TO AVERAGE...LOW 30S ON THE LAKE PLAINS AND UPPER 20S HIGHER TERRAIN. LATE MONDAY NIGHT THROUGH TUESDAY OUR ATTENTION TURNS TO THE NEXT SYNOPTIC SCALE SYSTEM. A MID LEVEL TROUGH EJECTING OUT OF THE PLAINS WILL GRADUALLY WEAKEN AS IT MOVES EAST THROUGH THE OHIO VALLEY AND MID ATLANTIC...BUT STILL MAINTAIN ENOUGH FORCING AND DEEP LAYER WARM ADVECTION/MOISTURE TO SUPPORT A BROAD AREA OF LIGHT SNOW ENTERING WESTERN NY LATE MONDAY NIGHT OR TUESDAY MORNING...THEN OVERSPREADING THE REST OF THE AREA ON TUESDAY. AMOUNTS SHOULD BE VERY LIGHT WITH THIS...PERHAPS AN INCH OR TWO IN SOME SPOTS. TEMPERATURES WARM ABOVE FREEZING DURING THE AFTERNOON IN MOST LOCATIONS WHICH WILL INHIBIT ANY FURTHER ACCUMULATION. THE LIGHT SNOW GRADUALLY TAPERS OF TUESDAY NIGHT AS THE WEAKENING SYSTEM PULLS OUT TO SEA...BUT WILL LEAVE BEHIND PLENTY OF CLOUD COVER AS LOW LEVEL MOISTURE BECOMES TRAPPED BENEATH A STEEPENING INVERSION ALOFT. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY BROAD HIGH PRESSURE WILL EXTEND FROM THE OHIO VALLEY NORTH AND EASTWARD ACROSS THE EASTERN GREAT LAKES REGION. LOW LEVEL MOISTURE REMAINS PLENTIFUL IN THE LOWER LAYER OF THE ATMOSPHERE...WHILE ALOFT BOTH THE GFS AND ECMWF HAVE A WEAK SHORT WAVE CROSSING THE REGION. WILL HAVE LOW CHC POPS WEDNESDAY FOR LIGHT SNOW...AND AS TEMPERATURE PROFILES WARM...THIS COULD MIX WITH LIGHT DRIZZLE OR RAIN. AS MOISTURE WANES SOME BEHIND THE WEAK UPPER LEVEL SHORT WAVE EXPECT THE SCATTERED LIGHT PRECIPITATION TO COME TO AN END WEDNESDAY NIGHT...THOUGH MOISTURE WILL STILL REMAIN HIGH ENOUGH TO SUPPORT PLENTY OF CLOUDS THROUGH THE NIGHT. THURSDAY AND FRIDAY PRECIPITATION WILL RETURN TO THE REGION AS BOTH THE 00Z GFS AND ECMWF WITH FAIRLY GOOD SUPPORT FROM THE GEFS HAVE A PACIFIC SHORTWAVE EJECTING OUT OF THE CENTRAL PLAINS AND TOWARD THE LOWER LAKES. INITIALLY RAIN MAY MIX IN THURSDAY ACROSS THE REGION...BUT WITH CAA BEHIND THE SHORT WAVE A TRANSITION TO ALL SNOW THURSDAY NIGHT AND FRIDAY IS LIKELY. WHETHER THESE SHORTWAVES PHASE OR NOT WILL LIKELY IMPACT THE TRACK OF THE STORM...WITH A PHASED SOLUTION TAKING A STORM PATH TO OUR WEST AND NORTH WITH MILD CONDITIONS THURSDAY. IF THESE SHORTWAVE DO NOT PHASE...A LESS AMPLIFIED FLOW IS EXPECTED HOLDING WARMER AIR TO THE SOUTH AND PRECIPITATION FAVORING MORE SNOW THAN RAIN. TEMPERATURES ALOFT AT 850 HPA DROP TO -8 TO -10C ON THE GLOBAL MODELS...AND LAKE ENHANCED SNOW POSSIBLE FRIDAY AND FRIDAY NIGHT AS THIS SYSTEM PULLS AWAY. BEING DAYS 5 AND 6 WILL STAY WITH CHC POPS FOR THE WORDING...AND FINE TUNE AS WE DRAW CLOSER TO THE EVENT TIME. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... COLD NORTHWEST FLOW CONTINUING TO GENERATE MULTIPLE BANDS OF LAKE EFFECT SNOW OFF BOTH LAKE ERIE AND LAKE ONTARIO. OUTSIDE THE LAKE BANDS VFR CONDITIONS EXIST. WITHIN THE LAKE BANDS...IFR VSBYS/CIGS ARE COMMON. WINDS HAVE GRADUALLY DROPPED OFF THIS AFTERNOON ALLOWING BLOWING SNOW TO BECOME LESS OF AN IMPACT. HIGH PRESSURE BUILDING INTO THE REGION TONIGHT AND MONDAY WILL GRADUALLY LESSEN THE LAKE BANDS. HOWEVER...A SIGNIFICANT LAKE BAND PRODUCING IFR CONDITIONS IS EXPECTED TO DEVELOP AROUND THE KFZY/KSYR AREA AND LIFT NORTHWARD TOWARD KART THROUGH MONDAY MORNING OUTLOOK... MONDAY NIGHT...MAINLY VFR. TUESDAY...MVFR WITH SNOW LIKELY. WEDNESDAY...MAINLY VFR. THURSDAY...MVFR WITH RAIN/SNOW LIKELY. FRIDAY...MVFR WITH CHC SNOW. && .MARINE... STRONG HIGH PRESSURE HAS SETTLED ACROSS THE CENTRAL PLAINS AND WILL BUILD NORTHWARD ACROSS THE LAKES THROUGH THE REMINDER OF THE WEEKEND. THE PRESSURE GRADIENT ACROSS THE LAKES WILL REMAIN TIGHT ENOUGH TODAY TO MAINTAIN SMALL CRAFT CONDITIONS ON THE LAKES THROUGH TONIGHT AND INTO MONDAY. HEAVY FREEZING SPRAY IS STILL POSSIBLE ACROSS LAKE ERIE THROUGH 10AM THIS MORNING THEN TEMPERATURES RISE HIGH ENOUGH TO NOT ALLOW CONCERN FOR THESE CONDITIONS. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...LAKE EFFECT SNOW ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST MONDAY FOR NYZ005-006. LAKE EFFECT SNOW WARNING UNTIL 6 AM EST MONDAY FOR NYZ004. LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR NYZ003. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NYZ002. LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ012-019-020-085. LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST MONDAY FOR NYZ014. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LEZ040-041. SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LOZ042>045. && $$ SYNOPSIS...SMITH NEAR TERM...TMA SHORT TERM...HITCHCOCK LONG TERM...HITCHCOCK/THOMAS AVIATION...TMA MARINE...HITCHCOCK/SMITH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1042 AM EST SUN FEB 12 2012 .SYNOPSIS... MUCH COLDER AIR WILL CONTINUE TO POUR IN THE REGION THROUGH THE REMAINDER OF THE WEEKEND. SNOW AND LOCALIZED LAKE EFFECT SNOWS SOUTHEAST OF THE LAKES WILL CONTINUE THROUGH TONIGHT. ANY LINGERING SNOW SHOWERS SOUTHEAST OF THE LAKES MONDAY MORNING WILL END AS HIGH PRESSURE BUILDS INTO THE REGION. ANOTHER WEAK SYSTEM MAY BRING SOME LIGHT SNOW ON TUESDAY AS TEMPERATURES MODERATE TO A LITTLE ABOVE AVERAGE AGAIN. && .NEAR TERM /THROUGH TONIGHT/... BAND OF INTENSE LAKE SNOWS DROPPING SOUTH IMPACTING THE NIAGARA FALLS/BUFFALO AREAS OVER TO ROCHESTER LATE THIS MORNING. THIS BAND DROPPING SNOWFALL RATES UP TO TWO INCHES PER HOUR. THIS BAND WILL CONTINUE TO SINK SOUTHWARD BUT LIKELY WEAKEN SOMEWHAT AS IT MOVES AWAY FROM LAKE INFLUENCES...WHICH IS SUPPORTED BY LATEST HRRR. LATEST HRRR AND WRF SUGGESTING WEAKER MULTIPLE BANDS WILL CONTINUE TO IMPACT BOTH LAKES THROUGH THE AFTERNOON. LAKE SNOW HEADLINES WILL REMAIN INTACT WITH ADDITIONAL AMOUNTS THROUGH THIS AFTERNOON IN THE 2-4/3-5 INCH RANGE IN FAVORED NORTHWEST FLOW AREAS. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AT THE START OF THE PERIOD MONDAY MORNING A LAKE EFFECT BAND WILL STILL BE ONGOING SOUTHEAST OF LAKE ONTARIO. INSTABILITY WILL BE ON THE WANE...WITH LAKE INDUCED EQUILIBRIUM LEVELS AROUND 6K FEET. DESPITE THE WEAKENING INSTABILITY...STILL FAVORABLE SNOW GROWTH AND LONG FETCH SHOULD KEEP A DECENT BAND GOING MONDAY MORNING AS IT LIFTS ACROSS OSWEGO COUNTY TOWARD THE TUG HILL WITH A FEW INCHES POSSIBLE. BY MIDDAY LAKE INDUCED INSTABILITY BEGINS TO WEAKEN FURTHER...AND THAT COMBINED WITH DIMINISHING SYNOPTIC SCALE MOISTURE AND INCREASING SHEAR WILL BREAK THE BAND APART INTO SCATTERED SNOW SHOWERS ACROSS THE TUG HILL REGION...THEN END ALTOGETHER BY EARLY MONDAY EVENING. OFF LAKE ERIE EXPECT LAKE EFFECT TO BE OVER BY 12Z MONDAY. OTHERWISE MOST AREAS SHOULD SEE A DECENT AMOUNT OF SUNSHINE ON MONDAY OUTSIDE OF THE LAKE ONTARIO LAKE EFFECT. MODERATING AIRMASS SHOULD BRING HIGHS BACK VERY CLOSE TO AVERAGE...LOW 30S ON THE LAKE PLAINS AND UPPER 20S HIGHER TERRAIN. LATE MONDAY NIGHT THROUGH TUESDAY OUR ATTENTION TURNS TO THE NEXT SYNOPTIC SCALE SYSTEM. A MID LEVEL TROUGH EJECTING OUT OF THE PLAINS WILL GRADUALLY WEAKEN AS IT MOVES EAST THROUGH THE OHIO VALLEY AND MID ATLANTIC...BUT STILL MAINTAIN ENOUGH FORCING AND DEEP LAYER WARM ADVECTION/MOISTURE TO SUPPORT A BROAD AREA OF LIGHT SNOW ENTERING WESTERN NY LATE MONDAY NIGHT OR TUESDAY MORNING...THEN OVERSPREADING THE REST OF THE AREA ON TUESDAY. AMOUNTS SHOULD BE VERY LIGHT WITH THIS...PERHAPS AN INCH OR TWO IN SOME SPOTS. TEMPERATURES WARM ABOVE FREEZING DURING THE AFTERNOON IN MOST LOCATIONS WHICH WILL INHIBIT ANY FURTHER ACCUMULATION. THE LIGHT SNOW GRADUALLY TAPERS OF TUESDAY NIGHT AS THE WEAKENING SYSTEM PULLS OUT TO SEA...BUT WILL LEAVE BEHIND PLENTY OF CLOUD COVER AS LOW LEVEL MOISTURE BECOMES TRAPPED BENEATH A STEEPENING INVERSION ALOFT. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY BROAD HIGH PRESSURE WILL EXTEND FROM THE OHIO VALLEY NORTH AND EASTWARD ACROSS THE EASTERN GREAT LAKES REGION. LOW LEVEL MOISTURE REMAINS PLENTIFUL IN THE LOWER LAYER OF THE ATMOSPHERE...WHILE ALOFT BOTH THE GFS AND ECMWF HAVE A WEAK SHORT WAVE CROSSING THE REGION. WILL HAVE LOW CHC POPS WEDNESDAY FOR LIGHT SNOW...AND AS TEMPERATURE PROFILES WARM...THIS COULD MIX WITH LIGHT DRIZZLE OR RAIN. AS MOISTURE WANES SOME BEHIND THE WEAK UPPER LEVEL SHORT WAVE EXPECT THE SCATTERED LIGHT PRECIPITATION TO COME TO AN END WEDNESDAY NIGHT...THOUGH MOISTURE WILL STILL REMAIN HIGH ENOUGH TO SUPPORT PLENTY OF CLOUDS THROUGH THE NIGHT. THURSDAY AND FRIDAY PRECIPITATION WILL RETURN TO THE REGION AS BOTH THE 00Z GFS AND ECMWF WITH FAIRLY GOOD SUPPORT FROM THE GEFS HAVE A PACIFIC SHORTWAVE EJECTING OUT OF THE CENTRAL PLAINS AND TOWARD THE LOWER LAKES. INITIALLY RAIN MAY MIX IN THURSDAY ACROSS THE REGION...BUT WITH CAA BEHIND THE SHORT WAVE A TRANSITION TO ALL SNOW THURSDAY NIGHT AND FRIDAY IS LIKELY. WHETHER THESE SHORTWAVES PHASE OR NOT WILL LIKELY IMPACT THE TRACK OF THE STORM...WITH A PHASED SOLUTION TAKING A STORM PATH TO OUR WEST AND NORTH WITH MILD CONDITIONS THURSDAY. IF THESE SHORTWAVE DO NOT PHASE...A LESS AMPLIFIED FLOW IS EXPECTED HOLDING WARMER AIR TO THE SOUTH AND PRECIPITATION FAVORING MORE SNOW THAN RAIN. TEMPERATURES ALOFT AT 850 HPA DROP TO -8 TO -10C ON THE GLOBAL MODELS...AND LAKE ENHANCED SNOW POSSIBLE FRIDAY AND FRIDAY NIGHT AS THIS SYSTEM PULLS AWAY. BEING DAYS 5 AND 6 WILL STAY WITH CHC POPS FOR THE WORDING...AND FINE TUNE AS WE DRAW CLOSER TO THE EVENT TIME. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... NORTHWEST FLOW ACROSS THE FORECAST AREA WITHIN AN ARCTIC AIRMASS HAS TRIGGERED LAKE EFFECT SNOW BANDS SOUTHEAST OF THE LAKE THIS MORNING. THIS IS ONLY AFFECTING THE KROC AND KJHW SITES WITH MVFR AND OCCASIONAL IFR VIS/CIGS WITHIN THE AREA OF THE SNOW BAND. ALL OTHER SITES OUTSIDE OF LAKE EFFECT ARE VFR. REGIONAL IR SATELLITE IS SHOWING A DISTURBANCE DRIFTING SOUTH FROM EASTERN ONTARIO THAT MAY BRING SOME VERY LIGHT SNOW TO THE FORECAST AREA THIS MORNING BUT SHOULD NOT IMPACT AVIATION. WINDS ARE ALSO GUSTY THIS MORNING AS A TIGHT PRESSURE GRADIENT EXISTS BETWEEN A STRONG HIGH CENTERED OVER THE CENTRAL U.S. AND A SURFACE LOW OFF THE CANADIAN MARITIMES. HIGH IS FORECAST TO EXPAND NORTH AND EAST TONIGHT CUTTING OFF MOST LAKE BANDS WITH WINDS SUBSIDING. ALL SITES SHOULD BE VFR BY LATE TONIGHT AS SURFACE HIGH TAKES CONTROL OF WEATHER. OUTLOOK... MONDAY...MAINLY VFR LOCALLY MVFR/IFR SOUTHEAST OF LAKE ONTARIO. TUESDAY...VFR/MVFR IN CHC OF SNOW. WEDNESDAY...MAINLY VFR. THURSDAY...MVFR WITH A CHANCE OF RAIN/SNOW. && .MARINE... STRONG HIGH PRESSURE HAS SETTLED ACROSS THE CENTRAL PLAINS AND WILL BUILD NORTHWARD ACROSS THE LAKES THROUGH THE REMINDER OF THE WEEKEND. THE PRESSURE GRADIENT ACROSS THE LAKES WILL REMAIN TIGHT ENOUGH TODAY TO MAINTAIN SMALL CRAFT CONDITIONS ON THE LAKES THROUGH TONIGHT AND INTO MONDAY. HEAVY FREEZING SPRAY IS STILL POSSIBLE ACROSS LAKE ERIE THROUGH 10AM THIS MORNING THEN TEMPERATURES RISE HIGH ENOUGH TO NOT ALLOW CONCERN FOR THESE CONDITIONS. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...LAKE EFFECT SNOW ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST MONDAY FOR NYZ005-006. LAKE EFFECT SNOW WARNING UNTIL 6 AM EST MONDAY FOR NYZ004. LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR NYZ003. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NYZ002. LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ012-019-020-085. LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST MONDAY FOR NYZ014. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LEZ040-041. SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LOZ042>045. && $$ SYNOPSIS...SMITH NEAR TERM...TMA SHORT TERM...HITCHCOCK LONG TERM...HITCHCOCK/THOMAS AVIATION...SMITH MARINE...HITCHCOCK/SMITH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1017 AM EST SUN FEB 12 2012 .SYNOPSIS... ARCTIC AIR WILL CONTINUE TO SPILL SOUTHEAST INTO THE REGION TODAY. THE COLD AIR HAS CAUSED LAKE EFFECT SNOW SHOWERS AND FLURRIES, THAT WILL CONTINUE INTO MONDAY. A WEAK STORM WILL MOVE THROUGH LATE TUESDAY AND TUESDAY NIGHT WITH A WIDESPREAD LIGHT SNOW. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM... MAIN BAND OF LE SNOW OVER CAYUGA COUNTY ACROSS WRN CORTLAND AND ERN TOMPKINS TO BROOME AND TIOGA. HRRR SEEMS TO HAVE A GOOD HANDLE ON THE BAND AND BEGINS TO LFT IT NEWRD IN RESPONSE TO THE APRCHG ARCTIC FNT. THIS ALIGNS WITH CRNT RADAR TRENDS AND DVLPG WLY FLOW SHOW ON SFC OBS. HRRR ALSO SHOWS THE BAND ALONG THE LAKE SHORE DROPPING SWRD WITH THE FNT AND GIVING MUCH OF THE FCST AREA...ESP ALONG AND WEST OF I81...ANOTHER GOOD BURST OF SNOW IN THE NEXT FEW HRS. HAVE ADJUSTED THE CVRG AND INTENSITY OF THE LE FOR THIS UPDATE...ALONG WITH A FEW OTR MINOR TWEEKS. 4 AM UPDATE... COLD AIR MOVING INTO THE REGION HAS CONTINUED A GENERAL AREA OF LAKE EFFECT FLURRIES ACROSS THE CWA. A BAND OF LIGHT TO MODERATE SNOW IS COMING SOUTHEAST OFF OF LAKE CAYUGA. THIS NNW FLOW WILL SHIFT TO NW TODAY SO NOT EXPECTING THIS TO LAST BEYOND NOON. ANOTHER BAND IS CONTINUED TO GEORGIAN BAY INTO ROCHESTER. THIS SHOULD EXTEND FURTHER INLAND INTO THE FINGER LAKES THIS MORNING AND CONTINUE THIS AFTERNOON. LAKE EFFECT WILL BECOME HEAVIER ACROSS CENTRAL NEW YORK AS A SECONDARY COLD FRONT IN SE ONTARIO MOVES SOUTHEAST TODAY. EXPANDED THE LES ADVISORY TO INCLUDE YATES AND CHENANGO AS WELL AS TOMPKINS AND TIOGA FOR THE CAYUGA BAND. IN ADDITION A WIND CHILL ADVISORY CONTINUES FOR NORTHERN ONEIDA COUNTY THIS MORNING. WIND CHILLS RIGHT AROUND MINUS FIFTEEN F THERE. THIS AREA WILL WARM SLOWLY AS SEEN HERE. TEMPERATURES AND DEW POINTS ON THE RISE WITH THE ADDED MOISTURE AND CLOUDS. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... 4 AM UPDATE... LAKE EFFECT SNOW WILL CONTINUING TONIGHT INTO MONDAY. WAA STARTS SLOWLY WHILE THE NW FLOW SLOWLY SHIFT TO W. THIS EVENING SNOW SHOWERS WILL BE ACROSS MOST OF THE CWA WITH THE HEAVIEST ACROSS THE NORTHERN COUNTIES IN THE ADVISORY. CONNECTION TO GEORGIAN BAY SHOULD CONTINUE MOST OF THE NIGHT. BY MONDAY MORNING THE LAKE SNOW WILL BE OUT NE PA. THE FLOW WILL BE 290 INTO ONEIDA COUNTY. A LES ADVISORY MAY BE NEEDED FOR ONEIDA FOR TONIGHT INTO MONDAY. MONDAY UPPER LEVEL RIDGING AND WAA WILL QUICKEN. THE LOW LEVEL SLOW GOES TO THE SW ACROSS THE ENTIRE REGION BY TUESDAY MORNING. 850 WINDS ARE STILL WEST BUT TEMPERATURES NOT ENOUGH TO CREATE LAKE EFFECT SNOW MONDAY OVERNIGHT. TUESDAY TEMPERATURES BACK TO NORMAL. INCREASING CLOUDS WITH MAYBE A FLURRY LATE IN THE DAY. A WEAK COLD FRONT WILL MOVE THROUGH TUESDAY NIGHT. SOME LIGHT SNOW SHOWERS ARE EXPECTED WITH IT. MOISTURE AND FORCING ARE LACKING. THE JET STREAM AND SFC LOW REMAIN WELL SOUTH OF THE REGION. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 4AM UPDATE... ON THE LARGE-SCALE...MEDIUM RANGE MODELS (EC/GFS/CMC) CONTINUE TO AGREE FAIRLY WELL THIS CYCLE (00Z SUN)...THAT PACIFIC ORIGIN DISTURBANCES WILL ZIP ACROSS THE CONUS THIS PD IN A FAST ZONAL FLOW PATN...AND IMPACT NY/PA ABT EVERY 48 HRS...TRACKING UNDERNEATH A FLAT ERN CANADIAN TROUGH AND OVER THE TOP OF UPR RIDGING OFF THE SERN U.S. COAST. ALTHOUGH SOME HIGHER LAT BLOCKING DOES PRESENT ITSELF ACROSS THE N ATLANTIC FROM TIME TO TIME THIS PD...ITS OVERALL LACK OF PERSISTENCE SHOULD PRECLUDE ANY MAJOR STORMS FROM TAKING SHAPE FOR THE NERN U.S. IT APPEARS THAT ANY TRUE ARCTIC AIR MASSES WILL REMAIN N OF THE U.S./CANADIAN BORDER...ALLOWING TEMPS TO AVERAGE CLOSE TO SEASONAL NORMS FOR MID TO LATE FEB (HIGHS IN THE 30S AND 40S). OVERALL...VERY LTL CHANGE WAS MADE TO THE CURRENT SET OF GRIDS. IT STILL LOOKS LIKE FAST MOVING STORM SYSTEMS WILL BRING SHOTS OF -RA/-SN INTO WED...AGN TWDS THE END OF THE WEEK (LATE THU AND FRI)...AND POSSIBLY JUST BEYOND THE PD (SUN INTO MON). A GENERAL LACK OF VERY COLD AIR WILL LIMIT LAKE RESPONSES FOLLOWING ANY OF THESE SYSTEMS. 420 PM UPDATE...HPC GRIDS FORMED BASIS OF LONG TERM FORECAST...WHICH IS INITIALLY DOMINATED BY A SOUTHWEST FLOW THAT HAS BEEN QUITE FAMILIAR THIS WINTER...AND SO GENERALLY ABOVE NORMAL TEMPERATURES. HOWEVER...TOWARDS END OF THE PERIOD...THERE IS UNCERTAINTY AS TO HOW MUCH OF A TROUGH PATTERN COULD SET UP OVER THE NORTHEAST. SURFACE HIGH PRESSURE GRADUALLY TAKES CHARGE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THOUGH WARM AIR ADVECTION WAVE ALOFT PASSES THROUGH WITH A FAIR AMOUNT OF MOISTURE. I KEPT ONLY LOW CHANCE POPS IN TUESDAY NIGHT...BECAUSE OF UNCERTAINTY AS TO IF ANY PRECIPITATION CAN ACTUALLY REACH THE GROUND. IT MAY INDEED ONLY TURN OUT TO BE ONLY AN OVERCAST SKY. NEXT WAVE COMES LATE THURSDAY-FRIDAY...AS EITHER A NEGATIVELY TILTED COLD FRONT OR AN OCCLUDED FRONT. ECWMF PREFERS MORE OF AN INSTANT OCCLUSION SCENARIO AS OHIO VALLEY LOW APPROACHES WESTERN NY THURSDAY EVENING...BUT NEW LOW ALSO DEVELOPS AND STRENGTHENS OFFSHORE. THAT COULD POTENTIALLY YIELD A FAIR SYNOPTIC SNOW FOR THE AREA...YET WE COULD ALSO QUICKLY GET INTO DRY SLOT WHICH WOULD LIMIT AMOUNTS. GFS WAITS UNTIL WELL AFTER FRONT PASSES...BEFORE ANY COASTAL SURFACE REFLECTION OF NEW LOW BECOMES APPARENT. IN THIS CASE...PRECIPITATION WOULD BE MORE OF A QUICK SHOT...WITH MORE TIME FOR WARM AIR TO BE INVOLVED AHEAD OF THE FRONT...SO PRECIPITATION TYPE IS IN QUESTION. GIVEN ALL OF THESE UNCERTAINTIES...FIGURED MID CHANCE RANGE POPS OFFERED BY HPC SUFFICED WELL...AS IT LOOKS UNSETTLED AND WE JUST HAVE TO SORT OUT THE DETAILS IN COMING DAYS. GFS DOES BRING A BRIEF PIECE OF COLDER AIR IN BY NEXT SATURDAY...WITH DEEPER YET ALSO TEMPORARY UPPER TROUGH. I PLACED SOME CHANCE POPS IN CENTRAL NEW YORK FOR POSSIBLE LAKE EFFECT AT THAT TIME. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... UPDATED AS OF 7 AM SUN... BANDS OF LES CONTINUE TO IMPACT WRN AND CNTRL NY ATTM. KITH/KBGM/KSYR WILL BE THE MOST LIKELY SITES TO EXPERIENCE IFR OVER THE NEAR-TERM...WITH LIGHTER -SHSN/FLRYS PROVIDING OCNL MVFR RESTRICTIONS AT KRME/KELM/KAVP. IN GENERAL...LES BANDS SHOULD BREAK UP A BIT THIS AFTN...WITH CONDS IMPROVING TO VFR...AND OCNL MVFR IN PASSING -SHSN. THIS EVE...ANOTHER LES BAND IS EXPECTED TO ORGANIZE ACRS UPSTATE NY...AND BRING AN EXTENDED PD OF IFR TO KSYR...EVENTUALLY REACHING KRME AFTER 06Z. WINDS WILL BECOME GUSTY AGAIN TODAY OUT OF THE NW (UP TO 25 KT)...SPCLY AFTER 15Z. GUSTY WINDS SHOULD PERSIST RIGHT THROUGH THE EVE HRS. .OUTLOOK... MON...MVFR/IFR POSSIBLE IN KSYR/KRME WITH ONGOING LAKE EFFECT ACTIVITY. TUE/WED...MVFR/IFR PSBL AT ALL TAF SITES IN LGT SNOW. THUR...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST MONDAY FOR NYZ015>018- 025-036-044-045-055. && $$ SYNOPSIS...TAC NEAR TERM...DGM/TAC SHORT TERM...TAC LONG TERM...MLJ/MDP AVIATION...CMG/MLJ
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
946 PM CST MON FEB 13 2012 .UPDATE... WITH LIGHT AND VARIABLE WINDS... MOSTLY CLEAR SKIES THIS EVENING... AND MOIST AIR AT THE SURFACE... FOG IS EXPECTED TO CONTINUE TO DEVELOP OVERNIGHT ACROSS PORTIONS OF THE FA... WITH THE LEAST LIKELY AREA BEING NORTHWEST OK. DEWPOINT DEPRESSIONS ARE ALREADY ZERO OR ONE IN MANY LOCATIONS. WITH THE LOW DEWPOINT DEPRESSIONS AND VISIBILITIES ALREADY LESS THAN A MILE IN SOME LOCATIONS WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR PARTS OF THE FA THROUGH 10 AM TUESDAY. THE ADVISORY MAY NEED TO BE EXTENDED FURTHER WEST AND/OR NORTH LATER TONIGHT BUT FOR NOW OUTLINED THE MOST LIKELY AREA. SOME LOCATIONS MAY ALSO DROP BELOW FREEZING WHICH COULD CAUSE SOME FREEZING FOG LEAVING A GLAZE OF ICE ON OBJECTS. OTHERWISE...MADE SOME ADJUSTMENTS TO HOURLY GRIDS AND LOW TEMPERATURES. THE FREEZING TEMPS MAY ALSO CAUSE SOME OF THE WET ROADS TO ICE OVER AGAIN TONIGHT LEADING TO SLIPPERY ROADWAYS. WILL SEND UPDATED PRODUCTS SHORTLY. MAXWELL && .PREV DISCUSSION... /ISSUED 549 PM CST MON FEB 13 2012/ AVIATION... UPPER LEVEL SYSTEM THAT BROUGHT WINTRY WEATHER TO ALL TERMINALS YESTERDAY HAS EXITED TO THE EAST. OVERNIGHT FORECAST IS SOMEWHAT COMPLEX DUE TO ONGOING LOW CIGS OVER EASTERN OKLAHOMA AND RESIDUAL SNOW PACK ACROSS MUCH OF CENTRAL AND SOUTHWEST OKLAHOMA. AS WINDS DECREASE THROUGH 03Z...EXPECT COMBINATION OF SURFACE MOISTURE AND COOLING TO ALLOW FOR WIDESPREAD FOG DEVELOPMENT. VEERING SURFACE WINDS ACROSS WESTERN OKLAHOMA MAY INITIALLY LIMIT LOW STRATUS FORMATION...BUT EXPECT LOW CIGS TO BUILD BACK IN LATE TONIGHT. MOST TAF SITES WILL SEE MVFR/IFR AND POSSIBLY LIFR VSBYS/CIGS THROUGH TUESDAY MORNING...EXCEPT KGAG AND KWWR...WHERE SOME LOW LEVEL DRYING HAS OCCURRED. PREV DISCUSSION... /ISSUED 307 PM CST MON FEB 13 2012/ DISCUSSION... ALTHOUGH STILL SOMEWHAT GUSTY THIS AFTERNOON... WINDS WILL BECOME LIGHT OVERNIGHT. BUT WITH THESE LIGHTER WINDS... THE REDEVELOPMENT OF A MOIST BOUNDARY LAYER /AND FRESH SNOW IN SOME LOCATIONS/ WILL LIKELY LEAD TO FOG DEVELOPMENT OVERNIGHT. THE RUC... HRRR AND NAM ARE VERY AGGRESSIVE WITH FOG DEVELOPMENT OVERNIGHT AND A FOG ADVISORY OR EVEN A FREEZING FOG ADVISORY MAY BE NEEDED TONIGHT/TUESDAY MORNING BUT WILL NOT ISSUE WITH THIS PACKAGE YET. WARMING TEMPERATURES ARE EXPECTED OVER THE NEXT COUPLE OF DAYS. NEXT STORM SYSTEM WILL MOVE THROUGH THE PLAINS ON WEDNESDAY WITH PRECIP MOVING EAST FOLLOWED BY GUSTY SOUTHWEST WINDS BEHIND A DRYLINE. LATER IN THE FORECAST... HAVE ADDED LOW POPS FRIDAY NIGHT WITH SOME QPF SIGNAL FROM BOTH GFS AND ECMWF... BUT OTHERWISE NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE EXTENDED PERIODS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 29 58 41 60 / 0 0 20 50 HOBART OK 28 54 39 61 / 0 0 10 20 WICHITA FALLS TX 34 65 46 69 / 0 0 30 40 GAGE OK 19 57 34 57 / 0 0 10 10 PONCA CITY OK 22 50 40 58 / 0 0 20 60 DURANT OK 35 57 50 70 / 0 0 30 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR OKZ018>020- 023>032-037>048-050>052. TX...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR TXZ086-089-090. && $$ 25/84
AREA FORECAST DISCUSSION
NWS NORMAN OK
549 PM CST MON FEB 13 2012 .AVIATION... UPPER LEVEL SYSTEM THAT BROUGHT WINTRY WEATHER TO ALL TERMINALS YESTERDAY HAS EXITED TO THE EAST. OVERNIGHT FORECAST IS SOMEWHAT COMPLEX DUE TO ONGOING LOW CIGS OVER EASTERN OKLAHOMA AND RESIDUAL SNOW PACK ACROSS MUCH OF CENTRAL AND SOUTHWEST OKLAHOMA. AS WINDS DECREASE THROUGH 03Z...EXPECT COMBINATION OF SURFACE MOISTURE AND COOLING TO ALLOW FOR WIDESPREAD FOG DEVELOPMENT. VEERING SURFACE WINDS ACROSS WESTERN OKLAHOMA MAY INITIALLY LIMIT LOW STRATUS FORMATION...BUT EXPECT LOW CIGS TO BUILD BACK IN LATE TONIGHT. MOST TAF SITES WILL SEE MVFR/IFR AND POSSIBLY LIFR VSBYS/CIGS THROUGH TUESDAY MORNING...EXCEPT KGAG AND KWWR...WHERE SOME LOW LEVEL DRYING HAS OCCURRED. && .PREV DISCUSSION... /ISSUED 307 PM CST MON FEB 13 2012/ DISCUSSION... ALTHOUGH STILL SOMEWHAT GUSTY THIS AFTERNOON... WINDS WILL BECOME LIGHT OVERNIGHT. BUT WITH THESE LIGHTER WINDS... THE REDEVELOPMENT OF A MOIST BOUNDARY LAYER /AND FRESH SNOW IN SOME LOCATIONS/ WILL LIKELY LEAD TO FOG DEVELOPMENT OVERNIGHT. THE RUC... HRRR AND NAM ARE VERY AGGRESSIVE WITH FOG DEVELOPMENT OVERNIGHT AND A FOG ADVISORY OR EVEN A FREEZING FOG ADVISORY MAY BE NEEDED TONIGHT/TUESDAY MORNING BUT WILL NOT ISSUE WITH THIS PACKAGE YET. WARMING TEMPERATURES ARE EXPECTED OVER THE NEXT COUPLE OF DAYS. NEXT STORM SYSTEM WILL MOVE THROUGH THE PLAINS ON WEDNESDAY WITH PRECIP MOVING EAST FOLLOWED BY GUSTY SOUTHWEST WINDS BEHIND A DRYLINE. LATER IN THE FORECAST... HAVE ADDED LOW POPS FRIDAY NIGHT WITH SOME QPF SIGNAL FROM BOTH GFS AND ECMWF... BUT OTHERWISE NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE EXTENDED PERIODS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 28 58 41 60 / 0 0 20 50 HOBART OK 26 54 39 61 / 0 0 10 20 WICHITA FALLS TX 33 65 46 69 / 0 0 30 40 GAGE OK 19 57 34 57 / 0 0 10 10 PONCA CITY OK 21 50 40 58 / 0 0 20 60 DURANT OK 35 57 50 70 / 0 0 30 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 25/84
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
546 PM EST SUN FEB 12 2012 .SYNOPSIS... THE COLD AIR WILL SLIDE OFF THE EAST COAST TONIGHT AND MONDAY. THE FLOW WILL BECOME NEARLY ZONAL AND TEMPERATURES WILL RETURN TO NEAR NORMAL. ANOTHER TROUGH IS FORECAST TO DEVELOP OVER THE EASTERN UNITED STATES LATER IN THE WEEK WITH SOME ADDITIONAL COLD AIR. && .NEAR TERM /THROUGH MONDAY/... WEAK SFC TROUGH DROPPING SOUTH THROUGH THE NERN HALF OF THE AREA THIS EVENING WILL CREATE A BRIEF PD OF ENHANCED SNOW SHOWERS...BUT SHOULD NOT AMOUNT TO MORE THAN A DUSTING TO AN INCH IN MOST PLACES. CURR HRRR RUN EXTENDS THE FORCING AND SOME VERY LIGHT ACCUMS INTO SCHUYLKILL CO IN ANOTHER HOUR OR TWO. DOWNSLOPING SHOULD REDUCE THE INTENSITY OF ANY NOW TO LITTLE MORE THAN FLURRIES AS IT COMES OFF OF BLUE MTN INTO THE LOWER SUSQ. WINDS ARE GUSTY ALONG THE LEADING EDGE OF THE TROUGH AS THE SHOWERS MOVE IN. SO...WILL BUMP WINDS UP ALONG WITH POPS THERE IN THE NE FOR THE FIRST FEW HRS OF THE FCST. BUT...THE TROUGH WASHES OUT AND SUNSET WILL ALSO DIMINISH THE LLVL INSTABILITY. EVENING WILL BRING LESS MIXING ON THE WHOLE AND THE GRADIENT SLACKENS AS WELL...SPELLING A CERTAIN END TO THE WORST OF THE GUSTY WINDS. THE WINT WX ADVY FOR THE SNOW BELT IS WEAK BUT WILL KEEP IT RUNNING FOR NOW...AS THE SNOW IS STILL GOING. THERE SHOULD NOT BE ENOUGH SNOW /3+ INCHES/ OVERNIGHT TO WARRANT KEEPING THE ADVY GOING. WINDS OVER OH AND A PEEK AT KCLE RADAR ALREADY HINT AT THE GRADUAL REDUCTION IN MOISTURE COMING OFF THE LAKES INTO PA THAT SHOULD OCCUR DURING THE NIGHT. EXPECT THE WRN AND NRN MTS TO STAY MOSTLY CLOUDY AND STILL HAVE SOME FLURRIES ALL NIGHT...WITH MOST GUIDANCE POINTING TO SOME LIGHT QPF THROUGH 12Z. TEMPS TONIGHT WILL NOT BE AS COLD AS LAST NIGHT AS 8H TEMPS RISE SLIGHTLY IN THE EAST AND SIGNIFICANTLY IN THE WEST. WILL ONLY MENTION A FLURRY IN THE WEST FOR A FEW HRS MON AM...AND KEEP IT DRY AND SUNNY ELSEWHERE. ANY SIG HIGH CLOUDS FROM THE NEXT SYSTEM HEADING TO US ON THE RELATIVELY MILD WESTERLY FLOW SHOULD HOLD OFF UNTIL AFTER SUNSET MONDAY. WINDS DON/T GO LIGHT IN MOST PLACES ON MONDAY SINCE THE CENTER OF THE SFC HIGH WILL BE TOO FAR TO THE SOUTH. MAXES WILL RUN IN THE NEAR NORMALS MONDAY WITH 8H TEMPS AROUND -4C IN THE AFTN WITH PLENTY OF SUNSHINE OVER MOST OF THE AREA. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... U.S./EURO OPERATIONAL MODELS AND ENSEMBLES SHOW A RELATIVELY WEAK SFC...AND FLAT UPPER WAVE HEADING EAST FROM THE OHIO VALLEY MONDAY NIGHT...HELPING TO THICKEN UP CLOUDS AND SPREAD SOME LIGHT SNOW SHOWERS ACROSS THE WRN MTNS AFTER MIDNIGHT. A FEW PERIODS OF LIGHT SNOW /OR MIXED PRECIP AT ELEVATIONS AOB 1000 FT MSL/ ARE LIKELY ON TUESDAY THROUGH EARLY TUESDAY NIGHT. 12Z SHORT RANGE OPERATIONAL MODELS AND 09Z SREF MEAN APPEARS TO INDICATE AROUND 0.25 INCH OF LEQ PRECIP...AND THE POTENTIAL FOR 1-2 INCHES OF SNOW ACCUM ACROSS THE CENTRAL AND NRN ZONES...WITH LESS THAN ONE INCH OF SLUSHY SNOW THROUGHOUT MUCH OF THE SUSQ VALLEY. DAYTIME TEMPS TUESDAY WILL BE WARM ENOUGH UNDER THE LATE FEBRUARY SUN TO MELT MUCH OF WAT FALLS THROUGHOUT THE VALLEYS OF THE CENTRAL AND SOUTH. MAX TEMPS WILL VARY FROM THE LOWER TO MID 30S ACROSS THE MTNS...TO THE LOWER 40S IN THE SE VALLEYS. MINS TUESDAY NIGHT /UNDER NW FLOW AFTER THE WAVE EXITS THE MID ATLANTIC COAST/ WILL RANGE THROUGH THE 20S. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... A BRIEF PERIOD OF LIGHTER WIND...AND AT LEAST PARTIAL CLEARING WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS EAST ACROSS THE STATE. AFTERNOON TEMPS WED WILL CLIMB TO THE UPPER 30S AND LOWER 40S IN THE MTNS...AND MID TO PERHAPS UPPER 40S IN THE SE PIEDMONT...WHICH WILL BE 5-7F ABOVE NORMAL. THE SECOND...AND LIKELY MORE SIGNIFICANT PRECIP EVENT OF THE WEEK AHEAD ARRIVES ON THURSDAY...AS A MODERATELY AMPLIFIED WAVE /THAT WILL BRING SOME SIGNIF SNOWS TO THE ROCKIES/ HEADS NE ACROSS THE PLAINS STATES AND MIDWEST...AND PHASES WITH SOME NRN STREAM ENERGY. THE SFC LOW SHOULD TAKE A TRACK ACROSS THE CENTRAL OR ERN GLAKES LATE THURSDAY AND THU NIGHT. MODEL SOUNDINGS AND LLVL WET BULB STRUCTURE FAVORS AN INITIAL PERIOD OF SNOW OR MIXED PRECIP...CHANGING TO MIXED PRECIP OR RAIN IN THE AFTERNOON AND EVENING AS WARMER AIR ALOFT SURGES NE INTO THE REGION. THE TRICKIER PART OF THE FCST FOR THURSDAY INTO THURSDAY NIGHT IS THE DEGREES OF SHALLOW...COLD AIR DAMMING TO THE EAST OF THE ALLEGHENY PLATEAU. WILL STILL FAVOR TEMPS CLIMBING TO ABOUT 5 DEG F ABOVE NORMAL LATER IN THE DAY THURSDAY AS THE MAIN WARM FRONTAL PRECIP SHIELD LIFTS NORTH OF THE REGION...WITH THE SFC CFRONT STILL LOCATED TO OUR WEST ACROSS OHIO. DRIER AND COOLER WEATHER PATTERN SETS IN FOR FRIDAY THROUGH MONDAY WITH ISOLATED TO SCATTERED...MAINLY MTN SNOW SHOWERS. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... COLD NW FLOW PRODUCING OROGRAPHICALLY ENHANCED LAKE EFFECT SNOW OVR THE ALLEGHENY MTNS EARLY THIS EVENING WITH IFR VSBYS AT BFD AND JST. DOWNWIND OF THE MTNS...GENERALLY VFR CONDS NOTED. IMPROVING VSBYS EXPECTED OVERNIGHT...AS APPROACHING HIGH PRES/LOWERING INVERSION HGTS CAUSES SHSN TO TAPER OFF. HOWEVER...MVFR CIGS ARE LIKELY TO LINGER AT BFD/JST THRU MON MORNING. OTHER AVIATION CONCERN IS THE STRONG/GUSTY NW WINDS BUFFETING THE AREA. SUSTAINED WINDS WILL ONLY SLOWLY DIMINISH OVERNIGHT DUE TO STRONG PRES GRADIENT REMAINING BTWN STORM OVR THE CANADIAN MARITIMES AND APPROACHING HIGH PRES. HOWEVER...THE 25-30KT GUSTS SHOULD ONLY LAST THRU EARLY THIS EVENING. OTHER THAN AM MVFR CIGS/FLURRIES OVR THE W MTNS...EXPECT MAINLY SUNNY SKIES MONDAY AS SFC HIGH PASSES SOUTH OF PA. WEST WINDS WILL REMAIN ACTIVE MONDAY...WITH MDL SOUNDINGS INDICATING FREQUENT GUSTS IN THE 20-25KT RANGE. OUTLOOK... TUE...MVFR IN -SN POSSIBLE. WED...MAINLY VFR...WRN MTS MAY DIP TO MVFR IN SHSN. THU...MVFR TO IFR IN SHRA/SN. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ004- 005. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...LAMBERT LONG TERM...LAMBERT AVIATION...DANGELO/FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
358 PM EST SUN FEB 12 2012 .SYNOPSIS... THE COLD AIR WILL SLIDE OFF THE EAST COAST TONIGHT AND MONDAY. THE FLOW WILL BECOME NEARLY ZONAL AND TEMPERATURES WILL RETURN TO NEAR NORMAL. ANOTHER TROUGH IS FORECAST TO DEVELOP OVER THE EASTERN UNITED STATES LATER IN THE WEEK WITH SOME ADDITIONAL COLD AIR. && .NEAR TERM /THROUGH MONDAY/... WEAK SFC TROUGH DROPPING SOUTH THROUGH THE NERN HALF OF THE AREA THIS EVENING WILL CREATE A BRIEF PD OF ENHANCED SNOW SHOWERS...BUT SHOULD NOT AMOUNT TO MORE THAN A DUSTING TO AN INCH IN MOST PLACES. CURR HRRR RUN EXTENDS THE FORCING AND SOME VERY LIGHT ACCUMS INTO SCHUYLKILL CO IN ANOTHER HOUR OR TWO. DOWNSLOPING SHOULD REDUCE THE INTENSITY OF ANY NOW TO LITTLE MORE THAN FLURRIES AS IT COMES OFF OF BLUE MTN INTO THE LOWER SUSQ. WINDS ARE GUSTY ALONG THE LEADING EDGE OF THE TROUGH AS THE SHOWERS MOVE IN. SO...WILL BUMP WINDS UP ALONG WITH POPS THERE IN THE NE FOR THE FIRST FEW HRS OF THE FCST. BUT...THE TROUGH WASHES OUT AND SUNSET WILL ALSO DIMINISH THE LLVL INSTABILITY. EVENING WILL BRING LESS MIXING ON THE WHOLE AND THE GRADIENT SLACKENS AS WELL...SPELLING A CERTAIN END TO THE WORST OF THE GUSTY WINDS. THE WINT WX ADVY FOR THE SNOW BELT IS WEAK BUT WILL KEEP IT RUNNING FOR NOW...AS THE SNOW IS STILL GOING. THERE SHOULD NOT BE ENOUGH SNOW /3+ INCHES/ OVERNIGHT TO WARRANT KEEPING THE ADVY GOING. WINDS OVER OH AND A PEEK AT KCLE RADAR ALREADY HINT AT THE GRADUAL REDUCTION IN MOISTURE COMING OFF THE LAKES INTO PA THAT SHOULD OCCUR DURING THE NIGHT. EXPECT THE WRN AND NRN MTS TO STAY MOSTLY CLOUDY AND STILL HAVE SOME FLURRIES ALL NIGHT...WITH MOST GUIDANCE POINTING TO SOME LIGHT QPF THROUGH 12Z. TEMPS TONIGHT WILL NOT BE AS COLD AS LAST NIGHT AS 8H TEMPS RISE SLIGHTLY IN THE EAST AND SIGNIFICANTLY IN THE WEST. WILL ONLY MENTION A FLURRY IN THE WEST FOR A FEW HRS MON AM...AND KEEP IT DRY AND SUNNY ELSEWHERE. ANY SIG HIGH CLOUDS FROM THE NEXT SYSTEM HEADING TO US ON THE RELATIVELY MILD WESTERLY FLOW SHOULD HOLD OFF UNTIL AFTER SUNSET MONDAY. WINDS DON/T GO LIGHT IN MOST PLACES ON MONDAY SINCE THE CENTER OF THE SFC HIGH WILL BE TOO FAR TO THE SOUTH. MAXES WILL RUN IN THE NEAR NORMALS MONDAY WITH 8H TEMPS AROUND -4C IN THE AFTN WITH PLENTY OF SUNSHINE OVER MOST OF THE AREA. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... U.S./EURO OPERATIONAL MODELS AND ENSEMBLES SHOW A RELATIVELY WEAK SFC...AND FLAT UPPER WAVE HEADING EAST FROM THE OHIO VALLEY MONDAY NIGHT...HELPING TO THICKEN UP CLOUDS AND SPREAD SOME LIGHT SNOW SHOWERS ACROSS THE WRN MTNS AFTER MIDNIGHT. A FEW PERIODS OF LIGHT SNOW /OR MIXED PRECIP AT ELEVATIONS AOB 1000 FT MSL/ ARE LIKELY ON TUESDAY THROUGH EARLY TUESDAY NIGHT. 12Z SHORT RANGE OPERATIONAL MODELS AND 09Z SREF MEAN APPEARS TO INDICATE AROUND 0.25 INCH OF LEQ PRECIP...AND THE POTENTIAL FOR 1-2 INCHES OF SNOW ACCUM ACROSS THE CENTRAL AND NRN ZONES...WITH LESS THAN ONE INCH OF SLUSHY SNOW THROUGHOUT MUCH OF THE SUSQ VALLEY. DAYTIME TEMPS TUESDAY WILL BE WARM ENOUGH UNDER THE LATE FEBRUARY SUN TO MELT MUCH OF WAT FALLS THROUGHOUT THE VALLEYS OF THE CENTRAL AND SOUTH. MAX TEMPS WILL VARY FROM THE LOWER TO MID 30S ACROSS THE MTNS...TO THE LOWER 40S IN THE SE VALLEYS. MINS TUESDAY NIGHT /UNDER NW FLOW AFTER THE WAVE EXITS THE MID ATLANTIC COAST/ WILL RANGE THROUGH THE 20S. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... A BRIEF PERIOD OF LIGHTER WIND...AND AT LEAST PARTIAL CLEARING WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS EAST ACROSS THE STATE. AFTERNOON TEMPS WED WILL CLIMB TO THE UPPER 30S AND LOWER 40S IN THE MTNS...AND MID TO PERHAPS UPPER 40S IN THE SE PIEDMONT...WHICH WILL BE 5-7F ABOVE NORMAL. THE SECOND...AND LIKELY MORE SIGNIFICANT PRECIP EVENT OF THE WEEK AHEAD ARRIVES ON THURSDAY...AS A MODERATELY AMPLIFIED WAVE /THAT WILL BRING SOME SIGNIF SNOWS TO THE ROCKIES/ HEADS NE ACROSS THE PLAINS STATES AND MIDWEST...AND PHASES WITH SOME NRN STREAM ENERGY. THE SFC LOW SHOULD TAKE A TRACK ACROSS THE CENTRAL OR ERN GLAKES LATE THURSDAY AND THU NIGHT. MODEL SOUNDINGS AND LLVL WET BULB STRUCTURE FAVORS AN INITIAL PERIOD OF SNOW OR MIXED PRECIP...CHANGING TO MIXED PRECIP OR RAIN IN THE AFTERNOON AND EVENING AS WARMER AIR ALOFT SURGES NE INTO THE REGION. THE TRICKIER PART OF THE FCST FOR THURSDAY INTO THURSDAY NIGHT IS THE DEGREES OF SHALLOW...COLD AIR DAMMING TO THE EAST OF THE ALLEGHENY PLATEAU. WILL STILL FAVOR TEMPS CLIMBING TO ABOUT 5 DEG F ABOVE NORMAL LATER IN THE DAY THURSDAY AS THE MAIN WARM FRONTAL PRECIP SHIELD LIFTS NORTH OF THE REGION...WITH THE SFC CFRONT STILL LOCATED TO OUR WEST ACROSS OHIO. DRIER AND COOLER WEATHER PATTERN SETS IN FOR FRIDAY THROUGH MONDAY WITH ISOLATED TO SCATTERED...MAINLY MTN SNOW SHOWERS. && .AVIATION /21Z SUNDAY THROUGH FRIDAY/... TYPICAL NW FLOW MEANS IFR/OCNL MVFR OVER THE WRN SITES OF BFD AND JST. EXPECT VFR CIGS AT AOO. A BRIEF PD OF MVFR CIGS AND MVFR OR EVEN IFR VSBY IS POSSIBLE BEFORE 00Z AT UNV AND IPT AS A WEAK SFC TROUGH PUSHES ACROSS. THIS TROUGH COULD ALSO ENHANCE THE WINDS TO 20G30KT. VFR IN THE SERN SITES. THE GUSTY WINDS ELSEWHERE WILL CONTINUE FOR THE EARLY EVENING WITH 40+ KT FLOW JUST 2-3KFT ALOFT. THE GUSTS WILL DIMINISH SLIGHTLY THIS EVENING WITH SHALLOW- ER MIXING AND THE HIGH BUILD TO OUR SOUTH. EXPECT THE WRN TERMINALS TO STAY LOW IN VSBY AND CIGS THROUGH MOST OF THE NIGHT AND FLURRIES COULD LAST INTO 12-15Z MONDAY. BIG SFC HIGH TO THE S WILL MAKE FOR SUNNY SKIES OVER MOST OF THE AREA. OUTLOOK... TUE...MVFR IN -SN POSSIBLE. WED...MAINLY VFR...WRN MTS MAY DIP TO MVFR IN SHSN. THU...MVFR TO IFR IN SHRA/SN. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ004- 005. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...LAMBERT LONG TERM...LAMBERT AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
259 PM EST SUN FEB 12 2012 .SYNOPSIS... THE COLD AIR WILL SLIDE OFF THE EAST COAST TONIGHT AND MONDAY. THE FLOW WILL BECOME NEARLY ZONAL AND TEMPERATURES WILL RETURN TO NEAR NORMAL. ANOTHER TROUGH IS FORECAST TO DEVELOP OVER THE EASTERN UNITED STATES LATER IN THE WEEK WITH SOME ADDITIONAL COLD AIR. && .NEAR TERM /THROUGH MONDAY/... WEAK SFC TROUGH DROPPING SOUTH THROUGH THE NERN HALF OF THE AREA THIS EVENING WILL CREATE A BRIEF PD OF ENHANCED SNOW SHOWERS...BUT SHOULD NOT AMOUNT TO MORE THAN A DUSTING TO AN INCH IN MOST PLACES. CURR HRRR RUN EXTENDS THE FORCING AND SOME VERY LIGHT ACCUMS INTO SCHUYLKILL CO IN ANOTHER HOUR OR TWO. DOWNSLOPING SHOULD REDUCE THE INTENSITY OF ANY NOW TO LITTLE MORE THAN FLURRIES AS IT COMES OFF OF BLUE MTN INTO THE LOWER SUSQ. WINDS ARE GUSTY ALONG THE LEADING EDGE OF THE TROUGH AS THE SHOWERS MOVE IN. SO...WILL BUMP WINDS UP ALONG WITH POPS THERE IN THE NE FOR THE FIRST FEW HRS OF THE FCST. BUT...THE TROUGH WASHES OUT AND SUNSET WILL ALSO DIMINISH THE LLVL INSTABILITY. EVENING WILL BRING LESS MIXING ON THE WHOLE AND THE GRADIENT SLACKENS AS WELL...SPELLING A CERTAIN END TO THE WORST OF THE GUSTY WINDS. THE WINT WX ADVY FOR THE SNOW BELT IS WEAK BUT WILL KEEP IT RUNNING FOR NOW...AS THE SNOW IS STILL GOING. THERE SHOULD NOT BE ENOUGH SNOW /3+ INCHES/ OVERNIGHT TO WARRANT KEEPING THE ADVY GOING. WINDS OVER OH AND A PEEK AT KCLE RADAR ALREADY HINT AT THE GRADUAL REDUCTION IN MOISTURE COMING OFF THE LAKES INTO PA THAT SHOULD OCCUR DURING THE NIGHT. EXPECT THE WRN AND NRN MTS TO STAY MOSTLY CLOUDY AND STILL HAVE SOME FLURRIES ALL NIGHT...WITH MOST GUIDANCE POINTING TO SOME LIGHT QPF THROUGH 12Z. TEMPS TONIGHT WILL NOT BE AS COLD AS LAST NIGHT AS 8H TEMPS RISE SLIGHTLY IN THE EAST AND SIGNIFICANTLY IN THE WEST. WILL ONLY MENTION A FLURRY IN THE WEST FOR A FEW HRS MON AM...AND KEEP IT DRY AND SUNNY ELSEWHERE. ANY SIG HIGH CLOUDS FROM THE NEXT SYSTEM HEADING TO US ON THE RELATIVELY MILD WESTERLY FLOW SHOULD HOLD OFF UNTIL AFTER SUNSET MONDAY. WINDS DON/T GO LIGHT IN MOST PLACES ON MONDAY SINCE THE CENTER OF THE SFC HIGH WILL BE TOO FAR TO THE SOUTH. MAXES WILL RUN IN THE NEAR NORMALS MONDAY WITH 8H TEMPS AROUND -4C IN THE AFTN WITH PLENTY OF SUNSHINE OVER MOST OF THE AREA. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/... THE THREAT OF LIGHT PCPN WILL RETURN TO THE FORECAST EARLY TUES. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... PERHAPS A MORE SIGNIFICANT STORM SYSTEM WILL AFFECT THE REGION SOMETIME LATE NEXT WEEK. SIMILAR TO YESTERDAY...OPERATIONAL MODEL AND ENSEMBLE GUIDANCE STILL SHOW UNCERTAINTY WITH SHORTWAVE TIMING AND POTENTIAL PHASING OF STREAMS. AFTER A TASTE OF WINTER THIS WEEKEND...EXPECT TEMPERATURES TO SLOWLY MODERATE IN TIME EVENTUALLY CLIMBING BACK NEAR TO SLIGHTLY ABOVE NORMAL BY THE END OF THE MEDIUM RANGE PD. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... TYPICAL NW FLOW MEANS IFR/OCNL MVFR OVER THE WRN SITES OF BFD AND JST. EXPECT VFR CIGS AT AOO. A BRIEF PD OF MVFR CIGS AND MVFR OR EVEN IFR VSBY IS POSSIBLE BEFORE 00Z AT UNV AND IPT AS A WEAK SFC TROUGH PUSHES ACROSS. THIS TROUGH COULD ALSO ENHANCE THE WINDS TO 20G30KT. VFR IN THE SERN SITES. THE GUSTY WINDS ELSEWHERE WILL CONTINUE FOR THE EARLY EVENING WITH 40+ KT FLOW JUST 2-3KFT ALOFT. THE GUSTS WILL DIMINISH SLIGHTLY THIS EVENING WITH SHALLOW- ER MIXING AND THE HIGH BUILD TO OUR SOUTH. EXPECT THE WRN TERMINALS TO STAY LOW IN VSBY AND CIGS THROUGH MOST OF THE NIGHT AND FLURRIES COULD LAST INTO 12-15Z MONDAY. BIG SFC HIGH TO THE S WILL MAKE FOR SUNNY SKIES OVER MOST OF THE AREA. OUTLOOK... TUE...MVFR IN -SN POSSIBLE. WED...MAINLY VFR...WRN MTS MAY DIP TO MVFR IN SHSN. THU...MVFR TO IFR IN SHRA/SN. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ004- 005. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DEVOIR/CERU LONG TERM...GRUMM/DEVOIR AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
943 PM CST MON FEB 13 2012 .UPDATE... AS EXPECTED FOG IS SETTLING IN OVER MUCH OF THE CWA AND VISIBILITIES ARE FALLING. STRATUS DECK IS BUILDING DOWNWARD TO THE SURFACE IN THE CLOUDY AREAS...AND RADIATION FOG IS DEVELOPING IN THE CLEAR AREAS. SURFACE ANALYSIS INDICATES A SURFACE TROUGH ROUGHLY ALONG A LINE FROM GRAHAM TO STEPHENVILLE TO LAMPASAS. TO THE WEST OF THIS TROUGH...WESTERLY WINDS AND MUCH DRIER AIR WILL LIMIT FOG POTENTIAL. TO THE EAST OF THE TROUGH...EAST WINDS WILL ALLOW FOR WARM/MOIST ADVECTION DURING THE OVERNIGHT HOURS...SO FOG/STRATUS BANK WILL TEND TO BUILD WESTWARD. WESTWARD MOVING FOG BANK MAY OVERPOWER THE DRYING EFFECTS FROM THE SURFACE TROUGH WITH FOG ENCOMPASSING THE ENTIRE CWA BY MORNING. HI-RES SHORT TERM GUIDANCE IS SUGGESTING THE COLUMN OF COUNTIES FROM STEPHENS TO LAMPASAS WILL STAY CLEAR AND THUS WILL KEEP THEM OUT OF THE FOG ADVISORY FOR NOW DUE TO LOWER CONFIDENCE. WILL SET EXPIRATION OF DENSE FOG ADVISORY AT 11 AM...AS INVERSION WILL BE STRONG AND TOUGH TO BREAK. TR.92 && .AVIATION... WEAK SFC TROF/WARM FRONT CONTINUES TO SLOWLY MOVE NORTHEASTWARD ACROSS THE FORECAST AREA LATE THIS AFTERNOON. IFR CIGS CONTINUE TO ERODE FROM WEST TO EAST WITH THE CLEARING LINE ALONG THE I-35 CORRIDOR. WITH THE SUN SETTING IN THE NEXT HOUR...WINDS WILL BECOME LIGHT OUT OF THE SOUTHWEST AS GOOD RADIATIVE COOLING BEGINS. AREAS THAT ARE STILL CLOUDY OR JUST NOW CLEARING ALREADY HAVE SMALL TEMP/DEWPOINT SPREADS. CONSEQUENTLY...THE LIKELIHOOD FOR FOG DEVELOPMENT IS LOOKING PRETTY STRONG RIGHT NOW FOR THE MAIN TERMINALS AS WE HEAD INTO THE EVENING. HRRR DATA AND BOTH RUC AND NAM AVIATION PLUME DIAGRAMS ALL AGREE ON VISIBILITIES DROPPING ACROSS THE BOARD AT OR PERHAPS JUST BEFORE MIDNIGHT. FOG MAY TAKE LONGER TO MATERIALIZE ACROSS AREAS TO THE SOUTH AND THE SOUTHWEST INCLUDING KACT...WHERE TEMPERATURES WERE ABLE TO CLIMB INTO THE 50S AND 60S UNDER A FEW GOOD HOURS OF SUNSHINE. EITHER WAY IT LOOKS LIKE LIFR MAY BE AN ISSUE AT ALL THE MAJOR AIRPORTS DURING THE BUSY MORNING RUSHES. THE SUN ANGLE IS STILL FAIRLY LOW AND SIGNIFICANT IMPROVEMENT MAY HOLD OFF UNTIL LATE TUESDAY MORNING. ONE LIMITING FACTOR COULD BE IF THE LOW MVFR/IFR CLOUD DECK HANGS ON THROUGH THE NIGHT...SURFACE VISIBILITIES MAY REMAIN IN CHECK TOMORROW MORNING. WILL KEEP THIS POSSIBILITY IN MIND AS WE HEAD INTO THE EVENING AND OVERNIGHT HOURS AND MONITOR TRENDS AS CONDITIONS DEVELOP. 30 && .PREV DISCUSSION... /ISSUED 252 PM CST MON FEB 13 2012/ THE DRY LINE HAS PUSHED INTO WESTERN COUNTIES...BUT IT WILL RETREAT WEST AFTER SUNSET. LIGHT SOUTHEAST FLOW IS EXPECTED ACROSS ALL OF NORTH TEXAS TONIGHT. NOW THAT THE RAIN HAS MOVED EAST...THE MOISTURE LEFT BEHIND WILL LIKELY FORM FOG. GUIDANCE RELATIVE HUMIDITIES ALL APPROACH 100 PERCENT IN THE EASTERN TWO THIRDS OF NORTH TX...AND I HAVE ADDED WIDESPREAD FOG TO THE ZONES IN THOSE AREAS. THERE MAY BE SOME AREAS OF DENSE FOG...SO WILL LET THE EVENING SHIFT EXAMINE THE HIGH RESOLUTION MODELS AS THEY ARRIVE AND THEY CAN DETERMINE IF A DENSE FOG ADVISORY WILL BE NEEDED. A RAPID WARM UP IS EXPECTED TOMORROW WITH HIGH TEMPERATURES REACHING THE 70S IN THE SOUTHERN HALF ON TUESDAY. 70S WILL BE WIDESPREAD ON WEDNESDAY AS THE DRY LINE PUSHES INTO WESTERN ZONES. WEDNESDAY ALSO BRINGS SHOWERS AND THUNDERSTORMS TO THE EASTERN TWO THIRDS OF NORTH TEXAS AHEAD OF THE COLD FRONT. OUT WEST...GIVEN THE WEDNESDAY AFTERNOON WARM TEMPERATURES...WEST WINDS IN THE TEENS...AND LOW RELATIVE HUMIDITIES WEST OF THE DRY LINE...IT APPEARS THAT ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE. THE NEXT COLD FRONT MOVES THROUGH WEDNESDAY NIGHT...AND THURSDAY HIGHS WILL BE COOLER...WITH FRIDAY A BIT WARMER. PROGRESSIVE PATTERN WILL BRING A SYSTEM EVERY FEW DAYS...AND RAIN CHANCES CLIMB ON FRIDAY NIGHT INTO SATURDAY...AND THEN ONCE AGAIN ON TUESDAY. 84 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 41 68 56 75 44 / 5 5 30 30 10 WACO, TX 37 73 59 76 45 / 5 5 30 40 10 PARIS, TX 36 60 49 71 43 / 5 5 30 40 10 DENTON, TX 39 66 53 74 42 / 5 5 30 30 10 MCKINNEY, TX 40 65 54 73 44 / 5 5 30 40 10 DALLAS, TX 41 68 56 75 44 / 5 5 30 40 10 TERRELL, TX 42 68 55 74 45 / 5 5 30 40 10 CORSICANA, TX 43 72 57 76 46 / 5 5 30 50 10 TEMPLE, TX 38 75 61 77 46 / 5 5 30 40 10 MINERAL WELLS, TX 35 70 53 72 42 / 5 5 40 30 10 && .FWD WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 11 AM CST TUESDAY FOR TXZ091>095- 100>107-116>123-130>135-143>148-157>162-174-175. && $$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
543 PM CST MON FEB 13 2012 .AVIATION... WEAK SFC TROF/WARM FRONT CONTINUES TO SLOWLY MOVE NORTHEASTWARD ACROSS THE FORECAST AREA LATE THIS AFTERNOON. IFR CIGS CONTINUE TO ERODE FROM WEST TO EAST WITH THE CLEARING LINE ALONG THE I-35 CORRIDOR. WITH THE SUN SETTING IN THE NEXT HOUR...WINDS WILL BECOME LIGHT OUT OF THE SOUTHWEST AS GOOD RADIATIVE COOLING BEGINS. AREAS THAT ARE STILL CLOUDY OR JUST NOW CLEARING ALREADY HAVE SMALL TEMP/DEWPOINT SPREADS. CONSEQUENTLY...THE LIKELIHOOD FOR FOG DEVELOPMENT IS LOOKING PRETTY STRONG RIGHT NOW FOR THE MAIN TERMINALS AS WE HEAD INTO THE EVENING. HRRR DATA AND BOTH RUC AND NAM AVIATION PLUME DIAGRAMS ALL AGREE ON VISIBILITIES DROPPING ACROSS THE BOARD AT OR PERHAPS JUST BEFORE MIDNIGHT. FOG MAY TAKE LONGER TO MATERIALIZE ACROSS AREAS TO THE SOUTH AND THE SOUTHWEST INCLUDING KACT...WHERE TEMPERATURES WERE ABLE TO CLIMB INTO THE 50S AND 60S UNDER A FEW GOOD HOURS OF SUNSHINE. EITHER WAY IT LOOKS LIKE LIFR MAY BE AN ISSUE AT ALL THE MAJOR AIRPORTS DURING THE BUSY MORNING RUSHES. THE SUN ANGLE IS STILL FAIRLY LOW AND SIGNIFICANT IMPROVEMENT MAY HOLD OFF UNTIL LATE TUESDAY MORNING. ONE LIMITING FACTOR COULD BE IF THE LOW MVFR/IFR CLOUD DECK HANGS ON THROUGH THE NIGHT...SURFACE VISIBILITIES MAY REMAIN IN CHECK TOMORROW MORNING. WILL KEEP THIS POSSIBILITY IN MIND AS WE HEAD INTO THE EVENING AND OVERNIGHT HOURS AND MONITOR TRENDS AS CONDITIONS DEVELOP. 30 && .PREV DISCUSSION... /ISSUED 252 PM CST MON FEB 13 2012/ THE DRY LINE HAS PUSHED INTO WESTERN COUNTIES...BUT IT WILL RETREAT WEST AFTER SUNSET. LIGHT SOUTHEAST FLOW IS EXPECTED ACROSS ALL OF NORTH TEXAS TONIGHT. NOW THAT THE RAIN HAS MOVED EAST...THE MOISTURE LEFT BEHIND WILL LIKELY FORM FOG. GUIDANCE RELATIVE HUMIDITIES ALL APPROACH 100 PERCENT IN THE EASTERN TWO THIRDS OF NORTH TX...AND I HAVE ADDED WIDESPREAD FOG TO THE ZONES IN THOSE AREAS. THERE MAY BE SOME AREAS OF DENSE FOG...SO WILL LET THE EVENING SHIFT EXAMINE THE HIGH RESOLUTION MODELS AS THEY ARRIVE AND THEY CAN DETERMINE IF A DENSE FOG ADVISORY WILL BE NEEDED. A RAPID WARM UP IS EXPECTED TOMORROW WITH HIGH TEMPERATURES REACHING THE 70S IN THE SOUTHERN HALF ON TUESDAY. 70S WILL BE WIDESPREAD ON WEDNESDAY AS THE DRY LINE PUSHES INTO WESTERN ZONES. WEDNESDAY ALSO BRINGS SHOWERS AND THUNDERSTORMS TO THE EASTERN TWO THIRDS OF NORTH TEXAS AHEAD OF THE COLD FRONT. OUT WEST...GIVEN THE WEDNESDAY AFTERNOON WARM TEMPERATURES...WEST WINDS IN THE TEENS...AND LOW RELATIVE HUMIDITIES WEST OF THE DRY LINE...IT APPEARS THAT ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE. THE NEXT COLD FRONT MOVES THROUGH WEDNESDAY NIGHT...AND THURSDAY HIGHS WILL BE COOLER...WITH FRIDAY A BIT WARMER. PROGRESSIVE PATTERN WILL BRING A SYSTEM EVERY FEW DAYS...AND RAIN CHANCES CLIMB ON FRIDAY NIGHT INTO SATURDAY...AND THEN ONCE AGAIN ON TUESDAY. 84 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 41 68 56 75 44 / 5 5 30 30 10 WACO, TX 37 73 59 76 45 / 5 5 30 40 10 PARIS, TX 36 60 49 71 43 / 10 10 30 40 10 DENTON, TX 39 66 53 74 42 / 5 5 30 30 10 MCKINNEY, TX 40 65 54 73 44 / 10 5 30 40 10 DALLAS, TX 41 68 56 75 44 / 5 5 30 40 10 TERRELL, TX 42 68 55 74 45 / 10 5 30 40 10 CORSICANA, TX 43 72 57 76 46 / 10 5 30 50 10 TEMPLE, TX 38 75 61 77 46 / 5 5 30 40 10 MINERAL WELLS, TX 35 70 53 72 42 / 5 5 40 30 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 30/92
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1006 AM CST SUN FEB 12 2012 .DISCUSSION...MADE A FEW CHANGES TO THE TEMPERATURE FORECAST BASED ON CURRENT TRENDS AND LATEST MODEL DATA. OVERALL...NO SIGNIFICANT CHANGES TO THE FORECAST. TEMPERATURES WILL NOT WARM MUCH THIS AFTERNOON WITH OUR OVERNIGHT LOW TEMPERATURES BEFORE MIDNIGHT WITH THE RETURN OF EAST TO SOUTHEAST WIND EXPECTED TO WARM TEMPERATURES AFTER MIDNIGHT. PATCHY LIGHT RAIN ACROSS THE REGION THIS MORNING SHOULD EXPAND IN COVERAGE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS THE MAIN/STRONGER UPPER LEVEL DISTURBANCE APPROACHES SOUTH TEXAS. HAVE REMOVED THUNDER FOR THIS EVENING...YET KEPT IN AFTER MIDNIGHT ACROSS THE EAST AS SOUNDING INDICATE THE HIGHER LAPS RATES THAT WOULD SUPPORT EMBEDDED ELEVATED CONVECTION. NO OTHER CHANGES AT THIS TIME. && .PREV DISCUSSION... /ISSUED 534 AM CST SUN FEB 12 2012/ DISCUSSION...UPDATED FOR 12Z AVIATION. AVIATION...PASSING UPPER LEVEL DISTURBANCE WILL LEAD TO GRADUALLY LOWERING CIGS THROUGH TODAY AND INTO TONIGHT. AS OF 12Z ALL AREAS REMAIN VFR AS LOWER LAYERS OF THE ATMOSPHERE REMAIN DRY. THE MOISTURE IN THIS LAYER WILL GRADUALLY INCREASE THROUGH THE MORNING WITH CIGS LOWERING TO MVFR CONDITIONS. LATER IN THE AFTERNOON AND EVENING PERIODS OF IFR CONDITIONS WILL BE POSSIBLE. WHILE RAIN IS EXPECTED THROUGH THE DAY...A SLIGHT CHANCE OF THUNDERSTORMS WILL DEVELOP THIS EVENING AND OVERNIGHT. EXPECT LITTLE TO NO IMPROVEMENT IN CONDITIONS BY THE END OF THIS TAF PERIOD...BUT CONDITIONS SHOULD IMPROVE QUICKLY MONDAY AFTERNOON. PREV DISCUSSION... /ISSUED 437 AM CST SUN FEB 12 2012/ SHORT TERM (TODAY THROUGH MONDAY)...SEEING PATCHY LIGHT RAIN OR DRIZZLE DEVELOP ACROSS SOUTHWEST CWA THIS MORNING ASSOCIATED WITH THE FIRST PIECE OF ENERGY THAT WILL AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. DPT DEPRESSIONS ARE STILL QUITE HIGH THIS MORNING...10 TO 15 DEGREES FOR MOST LOCATIONS...SO WILL TAKE SOME TIME TO REALLY GET ANY SUBSTANTIAL RAIN TODAY. RUC SOUNDINGS SHOW LOW LEVELS BECOMING SATURATED BY MID TO LATE MORNING ACROSS THE AREA. 300K SURFACE COND PRES DEFICITS LAG A BIT BEHIND THIS TIMING...BUT 295K SURFACE IS A BIT QUICKER. WITH 25 TO 35KT ISENTROPIC UPGLIDE THINK BY MID MORNING SOUTHWEST PORTION OF THE CWA WILL BE SEEING LIGHT RAIN. WHILE TEMPERATURE PROFILE WILL BE ABOVE ZERO IN THE LOWEST 200 MB...EVAPORATIVE COOLING WILL LIKELY BRING THE PROFILE A LITTLE CLOSER TO ZERO FOR A TIME THIS MORNING. HOWEVER THINK PRECIP SHOULD REMAIN IN THE LIQUID PHASE AT THE SURFACE FOR ALL AREAS. RAIN CHANCES INCREASE THROUGHOUT THE DAY AS UPGLIDE CONTINUES. PWAT VALUES REMAIN RELATIVELY LOW THROUGH THE DAY...JUST ABOVE 1 INCH...WHICH SHOULD KEEP THE RAIN MAINLY LIGHT. AN UPPER LEVEL JET STREAK MOVING INTO GOOD POSITION OVER THE FORECAST AREA TONIGHT...AND SOME DECENT LOW TO MID LEVEL OMEGA WILL BRING A SLIGHT CHANCE FOR THUNDER TONIGHT INTO MONDAY. ISENTROPIC UPGLIDE CUTS OFF QUICKLY LATE MORNING AND EARLY AFTERNOON ON MONDAY WITH MOISTURE ALSO QUICKLY DECREASING AS LAYER WINDS SHIFT TO THE WEST. EXPECT MOST AREAS TO BE DONE WITH RAIN BY AROUND NOON ON MONDAY. SOME RAIN COULD BE LINGERING FAR EAST. SKIES SHOULD BEGIN TO CLEAR PRETTY QUICKLY IN THE AFTERNOON. AS FOR TEMPERATURES...WILL SEE LITTLE INCREASE IN TEMPS THIS AFTERNOON. WITH RUC MODEL ACTUALLY SHOWING HIGHS IN THE LOW TO MID 40S...BUT THINK THIS IS A BIT TOO LOW. MOST MODELS INDICATING HIGHS IN THE LOWER TO MID 50S. FORECAST WILL REFLECT NEAR OR SLIGHTLY UNDER A CONSENSUS OF GUIDANCE. WINDS SHIFT SOUTH AND SOUTHWEST FOR MONDAY AND EXPECT TEMPS 15 TO 20 DEGREES HIGHER AREA WIDE. LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...THE GFS/CANADIAN/ECMWF PROG AN UPPER DISTURBANCE TO MOVE ACROSS THE SRN PLAINS/NRN TX WEDNESDAY. RTN FLOW/INCREASING MSTR EXPECTED TUESDAY IN ADVANCE OF THIS SYSTEM. THE GFS/ECWMF PROG A COLD FRONT...CORRESPONDING TO THE UPPER DISTURBANCE...TO MOVE ACRS THE CWA WEDNESDAY AFTN/EVENING. THE COMBINATION OF SFC AND UPPER FORCING WILL CONTRIBUTE TO CONVECTION WEDNESDAY (GREATEST CHANCE OVER THE ERN CWA BASED ON MSTR CONSIDERATIONS) WITH ACTIVITY ENDING AFTER FROPA. ANTICIPATE SCA CONDITIONS OVER AT LEAST THE OFFSHORE COASTAL WATERS THURSDAY IN RESPONSE TO THE FRONT. THE MODELS DIFFER WITH RESPECT TO THE UPPER PATTERN THURSDAY-SATURDAY. REGARDLESS...ALL SOLNS APPEAR TO PROG AN UPPER PATTERN CONSISTENT WITH ISENTROPIC LIFT. YET...THE GFS PROGS ISENTROPIC LIFT SAT AND THE ECMWF SUNDAY. WILL ACCOUNT FOR UNCERTAINTY BY FCSTG LOW POP PCPN FOR SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 55 55 73 54 74 / 60 90 50 0 10 VICTORIA 49 47 68 49 73 / 40 80 70 10 0 LAREDO 48 48 69 54 79 / 80 50 20 0 0 ALICE 52 52 71 52 76 / 60 90 40 0 0 ROCKPORT 54 54 70 57 68 / 50 90 60 10 10 COTULLA 45 45 67 49 77 / 50 60 20 0 0 KINGSVILLE 55 55 73 53 76 / 70 90 40 0 0 NAVY CORPUS 57 56 72 59 69 / 60 90 50 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ RG/82...UPDATE
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
534 AM CST SUN FEB 12 2012 .DISCUSSION...UPDATED FOR 12Z AVIATION. && .AVIATION...PASSING UPPER LEVEL DISTURBANCE WILL LEAD TO GRADUALLY LOWERING CIGS THROUGH TODAY AND INTO TONIGHT. AS OF 12Z ALL AREAS REMAIN VFR AS LOWER LAYERS OF THE ATMOSPHERE REMAIN DRY. THE MOISTURE IN THIS LAYER WILL GRADUALLY INCREASE THROUGH THE MORNING WITH CIGS LOWERING TO MVFR CONDITIONS. LATER IN THE AFTERNOON AND EVENING PERIODS OF IFR CONDITIONS WILL BE POSSIBLE. WHILE RAIN IS EXPECTED THROUGH THE DAY...A SLIGHT CHANCE OF THUNDERSTORMS WILL DEVELOP THIS EVENING AND OVERNIGHT. EXPECT LITTLE TO NO IMPROVEMENT IN CONDITIONS BY THE END OF THIS TAF PERIOD...BUT CONDITIONS SHOULD IMPROVE QUICKLY MONDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 437 AM CST SUN FEB 12 2012/ SHORT TERM (TODAY THROUGH MONDAY)...SEEING PATCHY LIGHT RAIN OR DRIZZLE DEVELOP ACROSS SOUTHWEST CWA THIS MORNING ASSOCIATED WITH THE FIRST PIECE OF ENERGY THAT WILL AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. DPT DEPRESSIONS ARE STILL QUITE HIGH THIS MORNING...10 TO 15 DEGREES FOR MOST LOCATIONS...SO WILL TAKE SOME TIME TO REALLY GET ANY SUBSTANTIAL RAIN TODAY. RUC SOUNDINGS SHOW LOW LEVELS BECOMING SATURATED BY MID TO LATE MORNING ACROSS THE AREA. 300K SURFACE COND PRES DEFICITS LAG A BIT BEHIND THIS TIMING...BUT 295K SURFACE IS A BIT QUICKER. WITH 25 TO 35KT ISENTROPIC UPGLIDE THINK BY MID MORNING SOUTHWEST PORTION OF THE CWA WILL BE SEEING LIGHT RAIN. WHILE TEMPERATURE PROFILE WILL BE ABOVE ZERO IN THE LOWEST 200 MB...EVAPORATIVE COOLING WILL LIKELY BRING THE PROFILE A LITTLE CLOSER TO ZERO FOR A TIME THIS MORNING. HOWEVER THINK PRECIP SHOULD REMAIN IN THE LIQUID PHASE AT THE SURFACE FOR ALL AREAS. RAIN CHANCES INCREASE THROUGHOUT THE DAY AS UPGLIDE CONTINUES. PWAT VALUES REMAIN RELATIVELY LOW THROUGH THE DAY...JUST ABOVE 1 INCH...WHICH SHOULD KEEP THE RAIN MAINLY LIGHT. AN UPPER LEVEL JET STREAK MOVING INTO GOOD POSITION OVER THE FORECAST AREA TONIGHT...AND SOME DECENT LOW TO MID LEVEL OMEGA WILL BRING A SLIGHT CHANCE FOR THUNDER TONIGHT INTO MONDAY. ISENTROPIC UPGLIDE CUTS OFF QUICKLY LATE MORNING AND EARLY AFTERNOON ON MONDAY WITH MOISTURE ALSO QUICKLY DECREASING AS LAYER WINDS SHIFT TO THE WEST. EXPECT MOST AREAS TO BE DONE WITH RAIN BY AROUND NOON ON MONDAY. SOME RAIN COULD BE LINGERING FAR EAST. SKIES SHOULD BEGIN TO CLEAR PRETTY QUICKLY IN THE AFTERNOON. AS FOR TEMPERATURES...WILL SEE LITTLE INCREASE IN TEMPS THIS AFTERNOON. WITH RUC MODEL ACTUALLY SHOWING HIGHS IN THE LOW TO MID 40S...BUT THINK THIS IS A BIT TOO LOW. MOST MODELS INDICATING HIGHS IN THE LOWER TO MID 50S. FORECAST WILL REFLECT NEAR OR SLIGHTLY UNDER A CONSENSUS OF GUIDANCE. WINDS SHIFT SOUTH AND SOUTHWEST FOR MONDAY AND EXPECT TEMPS 15 TO 20 DEGREES HIGHER AREA WIDE. LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...THE GFS/CANADIAN/ECMWF PROG AN UPPER DISTURBANCE TO MOVE ACROSS THE SRN PLAINS/NRN TX WEDNESDAY. RTN FLOW/INCREASING MSTR EXPECTED TUESDAY IN ADVANCE OF THIS SYSTEM. THE GFS/ECWMF PROG A COLD FRONT...CORRESPONDING TO THE UPPER DISTURBANCE...TO MOVE ACRS THE CWA WEDNESDAY AFTN/EVENING. THE COMBINATION OF SFC AND UPPER FORCING WILL CONTRIBUTE TO CONVECTION WEDNESDAY (GREATEST CHANCE OVER THE ERN CWA BASED ON MSTR CONSIDERATIONS) WITH ACTIVITY ENDING AFTER FROPA. ANTICIPATE SCA CONDITIONS OVER AT LEAST THE OFFSHORE COASTAL WATERS THURSDAY IN RESPONSE TO THE FRONT. THE MODELS DIFFER WITH RESPECT TO THE UPPER PATTERN THURSDAY-SATURDAY. REGARDLESS...ALL SOLNS APPEAR TO PROG AN UPPER PATTERN CONSISTENT WITH ISENTROPIC LIFT. YET...THE GFS PROGS ISENTROPIC LIFT SAT AND THE ECMWF SUNDAY. WILL ACCOUNT FOR UNCERTAINTY BY FCSTG LOW POP PCPN FOR SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 53 53 73 54 74 / 60 90 50 0 10 VICTORIA 49 49 68 49 73 / 30 80 70 10 0 LAREDO 48 47 69 54 79 / 80 50 20 0 0 ALICE 51 51 71 52 76 / 60 90 40 0 0 ROCKPORT 54 54 70 57 68 / 40 90 60 10 10 COTULLA 46 44 67 49 77 / 50 60 20 0 0 KINGSVILLE 54 54 73 53 76 / 70 90 40 0 0 NAVY CORPUS 55 55 72 59 69 / 60 90 50 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ PZ/83...SHORT TERM WC/87...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
437 AM CST SUN FEB 12 2012 .SHORT TERM (TODAY THROUGH MONDAY)...SEEING PATCHY LIGHT RAIN OR DRIZZLE DEVELOP ACROSS SOUTHWEST CWA THIS MORNING ASSOCIATED WITH THE FIRST PIECE OF ENERGY THAT WILL AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. DPT DEPRESSIONS ARE STILL QUITE HIGH THIS MORNING...10 TO 15 DEGREES FOR MOST LOCATIONS...SO WILL TAKE SOME TIME TO REALLY GET ANY SUBSTANTIAL RAIN TODAY. RUC SOUNDINGS SHOW LOW LEVELS BECOMING SATURATED BY MID TO LATE MORNING ACROSS THE AREA. 300K SURFACE COND PRES DEFICITS LAG A BIT BEHIND THIS TIMING...BUT 295K SURFACE IS A BIT QUICKER. WITH 25 TO 35KT ISENTROPIC UPGLIDE THINK BY MID MORNING SOUTHWEST PORTION OF THE CWA WILL BE SEEING LIGHT RAIN. WHILE TEMPERATURE PROFILE WILL BE ABOVE ZERO IN THE LOWEST 200 MB...EVAPORATIVE COOLING WILL LIKELY BRING THE PROFILE A LITTLE CLOSER TO ZERO FOR A TIME THIS MORNING. HOWEVER THINK PRECIP SHOULD REMAIN IN THE LIQUID PHASE AT THE SURFACE FOR ALL AREAS. RAIN CHANCES INCREASE THROUGHOUT THE DAY AS UPGLIDE CONTINUES. PWAT VALUES REMAIN RELATIVELY LOW THROUGH THE DAY...JUST ABOVE 1 INCH...WHICH SHOULD KEEP THE RAIN MAINLY LIGHT. AN UPPER LEVEL JET STREAK MOVING INTO GOOD POSITION OVER THE FORECAST AREA TONIGHT...AND SOME DECENT LOW TO MID LEVEL OMEGA WILL BRING A SLIGHT CHANCE FOR THUNDER TONIGHT INTO MONDAY. ISENTROPIC UPGLIDE CUTS OFF QUICKLY LATE MORNING AND EARLY AFTERNOON ON MONDAY WITH MOISTURE ALSO QUICKLY DECREASING AS LAYER WINDS SHIFT TO THE WEST. EXPECT MOST AREAS TO BE DONE WITH RAIN BY AROUND NOON ON MONDAY. SOME RAIN COULD BE LINGERING FAR EAST. SKIES SHOULD BEGIN TO CLEAR PRETTY QUICKLY IN THE AFTERNOON. AS FOR TEMPERATURES...WILL SEE LITTLE INCREASE IN TEMPS THIS AFTERNOON. WITH RUC MODEL ACTUALLY SHOWING HIGHS IN THE LOW TO MID 40S...BUT THINK THIS IS A BIT TOO LOW. MOST MODELS INDICATING HIGHS IN THE LOWER TO MID 50S. FORECAST WILL REFLECT NEAR OR SLIGHTLY UNDER A CONSENSUS OF GUIDANCE. WINDS SHIFT SOUTH AND SOUTHWEST FOR MONDAY AND EXPECT TEMPS 15 TO 20 DEGREES HIGHER AREA WIDE. && .LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...THE GFS/CANADIAN/ECMWF PROG AN UPPER DISTURBANCE TO MOVE ACROSS THE SRN PLAINS/NRN TX WEDNESDAY. RTN FLOW/INCREASING MSTR EXPECTED TUESDAY IN ADVANCE OF THIS SYSTEM. THE GFS/ECWMF PROG A COLD FRONT...CORRESPONDING TO THE UPPER DISTURBANCE...TO MOVE ACRS THE CWA WEDNESDAY AFTN/EVENING. THE COMBINATION OF SFC AND UPPER FORCING WILL CONTRIBUTE TO CONVECTION WEDNESDAY (GREATEST CHANCE OVER THE ERN CWA BASED ON MSTR CONSIDERATIONS) WITH ACTIVITY ENDING AFTER FROPA. ANTICIPATE SCA CONDITIONS OVER AT LEAST THE OFFSHORE COASTAL WATERS THURSDAY IN RESPONSE TO THE FRONT. THE MODELS DIFFER WITH RESPECT TO THE UPPER PATTERN THURSDAY-SATURDAY. REGARDLESS...ALL SOLNS APPEAR TO PROG AN UPPER PATTERN CONSISTENT WITH ISENTROPIC LIFT. YET...THE GFS PROGS ISENTROPIC LIFT SAT AND THE ECMWF SUNDAY. WILL ACCOUNT FOR UNCERTAINTY BY FCSTG LOW POP PCPN FOR SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 53 53 73 54 74 / 60 90 50 0 10 VICTORIA 49 49 68 49 73 / 30 80 70 10 0 LAREDO 48 47 69 54 79 / 80 50 20 0 0 ALICE 51 51 71 52 76 / 60 90 40 0 0 ROCKPORT 54 54 70 57 68 / 40 90 60 10 10 COTULLA 46 44 67 49 77 / 50 60 20 0 0 KINGSVILLE 54 54 73 53 76 / 70 90 40 0 0 NAVY CORPUS 55 55 72 59 69 / 60 90 50 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 AM CST MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. && $$ PZ/83...SHORT TERM WC/87...LONG TERM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1121 AM CST SUN FEB 12 2012 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT 206 AM CST SUN FEB 12 2012 MAIN FORECAST CONCERN IS ON LIGHT SNOW FOR MONDAY INTO MONDAY NIGHT CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER SOUTHWEST INTO SOUTH CENTRAL CANADA...AS WELL AS OVER TEXAS INTO COLORADO...A SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST...A DEEPER SHORTWAVE TROUGH OVER THE DESERT SOUTHWEST... AND A LONG-WAVE TROUGH ALONG THE EASTERN SEABOARD. WITH 500MB HEIGHTS RISING OVER THE FORECAST AREA BEHIND THE LONG-WAVE TROUGH...WARMER AIR ALOFT IS BEGINNING TO FLOW IN FROM CENTRAL CANADA. INTERESTING THAT BETWEEN 00Z ON THE 10TH AND 00Z ON THE 12TH...850MB TEMPS HAVE WARMED ABOUT 16C ACROSS MUCH OF CENTRAL CANADA PER 00Z RAOBS. IN FACT...850MB TEMPS AT 00Z WERE -3C AT CHURCHILL MANITOBA...WARMER THAN THE AVERAGE -13C OVER THE FORECAST AREA. AIRMASS REMAINS DRY ACROSS THE ENTIRE UPPER MIDWEST...CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY REGIONS...NOTED BY PRECIPITABLE WATER VALUES BETWEEN 0.05-0.1 INCHES ON 00Z SOUNDINGS. THIS DRY AIR IS ASSOCIATED WITH AN AREA OF HIGH PRESSURE AT THE SURFACE THAT ENCOMPASSES ALL OF THE U.S. PLAINS. A SUSTAINED 5 TO 15 MPH NORTHWEST WIND OVER THE FORECAST AREA...ON THE EAST SIDE OF HIGH... HAS ONLY ALLOWED TEMPERATURES TO FALL INTO THE 8 TO 15F RANGE. TODAY AND TONIGHT...THE UPPER RIDGING SEEN FROM TEXAS INTO COLORADO IS PROGGED TO LIFT NORTHEAST TOWARDS THE AREA DURING THIS PERIOD...IN RESPONSE TO THE TWO SHORTWAVE TROUGHS OUT WEST MOVING OUT INTO THE WESTERN PLAINS. MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO AND DPVA AHEAD OF THESE TROUGHS SHOULD CAUSE PRECIPITATION TO BREAK OUT ACROSS MUCH OF THE PLAINS TONIGHT...PERHAPS REACHING INTO WESTERN IOWA LATE IN THE NIGHT. FOR OUR AREA...WE WILL REMAIN INFLUENCED BY THE DRY AIR ASSOCIATED WITH THE SURFACE HIGH...AND ITS RIDGE AXIS LOOKS TO CROSS TONIGHT. FULL SUN ANTICIPATED TODAY AND WITH 850MB TEMPS PROGGED AROUND -6C AT 18Z...TEMPERATURES SHOULD CLIMB INTO THE MID 20S TO NEAR 30. WILL STILL BE DEALING WITH A NORTHWEST TO WESTERLY BREEZE...BUT IT DOES NOT LOOK AS BREEZY AS YESTERDAY WITH A WEAKER PRESSURE GRADIENT PROGGED. THE WINDS MAY HAVE A SHOT OF DECOUPLING TONIGHT...ESPECIALLY OVER WESTERN WISCONSIN...SETTING UP BETTER RADIATIONAL COOLING. ON THE FLIP SIDE...A WARMER DAY TODAY WILL PROBABLY END UP RESULTING IN LOWS SIMILAR TO THOSE EXPERIENCED THIS MORNING. INCREASING MID/HIGH CLOUDS LATER IN THE NIGHT WEST OF THE MISSISSIPPI RIVER SHOULD KEEP TEMPERATURES A LITTLE WARMER THERE. MONDAY AND MONDAY NIGHT...MODELS ARE IN GOOD AGREEMENT TAKING THE TROUGHING OVER THE WESTERN PLAINS AT 12Z MONDAY MOSTLY INTO THE OHIO VALLEY REGION MONDAY NIGHT. THERE IS A NORTHERN EXTENSION THAT CROSSES THE FORECAST AREA LATE MONDAY INTO THE EARLY OVERNIGHT HOURS MONDAY NIGHT. WITH THE BULK OF THE TROUGH HEADING MORE TO THE SOUTH...THERE IS CONCERN ON HOW MUCH MOISTURE CAN MAKE IT NORTH INTO THE FORECAST AREA. CERTAINLY MODELS SUGGEST IT HAPPENS ENOUGH TO PRODUCE SOME LIGHT QPF ACROSS MUCH OF THE FORECAST AREA...THOUGH THE BEST MOISTURE TRANSPORT AND ISENTROPIC LIFT STAYS TO THE SOUTH AND EAST. SO BASICALLY THE HEIGHT FALLS AND DPVA FROM THE NORTHERN EXTENSION OF THE TROUGH WILL BE THE MAIN FORCING FUNCTION FOR THE PRECIPITATION. LOOKS LIKE PRECIPITATION SHOULD SLOWLY WORK SOUTHWEST TO NORTHEAST ACROSS THE AREA ON MONDAY...WITH THE LINGERING DRY AIR THE MAIN REASON FOR THE SLOW ADVANCEMENT. PRECIPITATION THEN DIMINISHES WEST TO EAST AFTER MIDNIGHT MONDAY NIGHT AS THE TROUGH PUSHES EAST. GOOD MODEL AGREEMENT REMAINS ON THIS LIGHT PRECIPITATION EVENT...SO HAVING THE HIGH PRECIPITATION CHANCES AS INDICATED BY THE PREVIOUS FORECAST SEEM REASONABLE. ONLY SLIGHT UPWARD MODIFICATIONS WERE MADE. WITH RESPECT TO AMOUNTS...THINK THE 12.00Z NAM IS A LITTLE TOO HIGH ON QPF GIVEN WEAK FORCING OVERALL. SHOULD MAINLY BE A 0.5 TO 1.5 INCH SNOW EVENT...WITH PERHAPS A FEW TOTALS SLIGHTLY HIGHER THAN THAT. WITH A FLOW OF WARMER AIR COMING IN WITH THE TROUGH...SLIGHTLY HIGHER HIGHS ARE ANTICIPATED FOR MONDAY COMPARED TO TODAY. IN FACT...AREAS ACROSS WISCONSIN COULD EVEN SEE SOME SUN IN THE MORNING. CLOUDY SKIES ARE EXPECTED ACROSS THE AREA MONDAY NIGHT...AND WITH LITTLE OR NO COLD ADVECTION...TEMPERATURES SHOULD ONLY DROP MAYBE 5 DEGREES FOR LOWS. TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THE MONDAY/MONDAY TROUGH...MODELS SHOW ONE MORE SHORTWAVE MOVING WEST TO EAST ACROSS THE FORECAST AREA LATE TUESDAY. APPEARS THIS SHORTWAVE WILL NOT HAVE MUCH MOISTURE OR EVEN PRODUCE MUCH FORCING...THEREFORE HAVE DRY CONDITIONS FOR TUESDAY. ON TUESDAY NIGHT...TROUGHING IS FORECAST TO DROP DOWN INTO MANITOBA WHILE TROUGHING IS SHOWN AGAIN OVER THE SOUTHWESTERN U.S.. HOWEVER...NEITHER FEATURE IS CLOSE ENOUGH TO BRING ANY PRECIPITATION TO THE AREA. IN FACT...THERE SHOULD BE SOME SLIGHT 500MB HEIGHT RISES TAKING PLACE. THEREFORE...DRY CONDITIONS CONTINUE. 850MB TEMPS PROGGED AROUND -6C ON TUESDAY COMBINED WITH SOME SLOW CLEARING AND A WARMER START WILL ALLOW FOR HIGHS A FEW DEGREES WARMER THAN MONDAY. A LITTLE BETTER NIGHT INDICATED FOR RADIATIONAL COOLING TUESDAY NIGHT WITH LIGHT WINDS...THOUGH THE AIRMASS OVERALL IS RELATIVELY SPEAKING WARM WITH 850MB TEMPS HOLDING NEARLY STEADY. IN ADDITION...THERE ARE HINTS OF SOME STRATUS TO MOVE IN LATER IN THE NIGHT. FOR NOW...FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT 206 AM CST SUN FEB 12 2012 12.00Z MODELS (ECMWF/CANADIAN/UKMET/GFS/GFS ENSEMBLES) DEPICT A MESSY UPPER LEVEL FLOW PATTERN THROUGHOUT THE LONG TERM...RESULTING IN QUITE A FEW DIFFERENCES BETWEEN ALL THE MODELS. IT APPEARS THIS IS A RESULT OF A FAST...ZONAL FLOW ACROSS THE PACIFIC RUNNING INTO SPLIT FLOW OVER THE U.S. AND SOUTHERN CANADA. DESPITE THE DIFFERENCES OF HANDLING SHORTWAVES...IN GENERAL THE LONG TERM PERIOD LOOKS PRETTY QUIET WITH ALL OF THE COLD...ARCTIC AIR BEING LOCKED UP OVER VERY FAR NORTHERN CANADA. THERE ARE A FEW FEATURES THAT MODELS AGREE UPON AND WILL DISCUSS THEM HERE. THE FIRST IS THE TROUGHING THAT DEVELOPS OVER THE SOUTHWESTERN U.S. TUESDAY NIGHT. 12.00Z ECMWF/GFS/UKMET ARE ALL IN AGREEMENT ON SHEARING THIS TROUGH OUT AND TRACKING IT THROUGH THE OHIO VALLEY ON THURSDAY. THIS TRACK AND GIVEN THE FACT THAT IS SHEARING WOULD KEEP THE BULK OF THE PRECIPITATION SOUTH OF THE FORECAST AREA...OR PERHAPS CLIP NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE 12.00Z CANADIAN IS THE ONLY MODEL NOW STILL SUGGESTING A FARTHER NORTH...MORE PHASED LOOK... WHICH RESULTS IN A DEEPER SYSTEM SPREADING PRECIPITATION OVER MUCH OF THE AREA WEDNESDAY NIGHT INTO THURSDAY. HAVE LOWERED PRECIPITATION CHANCES SOME DURING THIS PERIOD GIVEN THE TREND TO THE UN-PHASED LOOK...AND STILL WOULD NOT BE SURPRISED IF IT ENDS UP DRY LIKE THE 12.00Z GFS SHOWS. UPPER LEVEL TROUGHING DOES DEVELOP OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION EASTWARD INTO NEW ENGLAND FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT. 850MB TEMPS ARE ONLY AROUND -4C IN THE TROUGH SO AGAIN...NOTHING THAT COLD. FLOW THEN TURNS MORE ZONAL FOR SATURDAY OVER THE AREA WITH NO PRECIPITATION SEEN. SO OUTSIDE OF THE WEDNESDAY NIGHT/THURSDAY TIME PERIOD...A DRY LONG TERM FORECAST IS EXPECTED. NO BIG WARM-UPS PLANNED EITHER. HOWEVER...GIVEN 850MB TEMPS STAYING MOSTLY BETWEEN -4C AND 1C... SURFACE TEMPERATURES SHOULD AT LEAST END UP 5-10 DEGREES NORMAL FOR BOTH HIGHS AND LOWS. LOOKING FARTHER OUT INTO EARLY NEXT WEEK...STILL NO SUGGESTIONS OF ANY MAJOR COOL DOWNS AS THE FAST PACIFIC FLOW CONTINUES...ALLOWING PACIFIC AIR TO CONTINUE TO FLOW ACROSS THE U.S. && .AVIATION...THROUGH 18Z MONDAY 1121 AM CST SUN FEB 12 2012 A RIDGE OF HIGH PRESSURE WILL DRIFT ACROSS THE AREA TONIGHT WITH CLEAR SKIES EXPECTED THROUGH ABOUT 3 AM. WINDS WILL ALSO BE LIGHT UNDER THE RIDGE...SLOWLY BACKING TO THE SOUTH THIS EVENING AND REMAINING IN THE 5 TO 10KT RANGE AS THE RIDGE AXIS PUSHES EAST OF THE AREA. HIGH/MID CLOUDS ARE THEN EXPECTED TO SPREAD WEST TO EAST INTO THE AREA AFTER 3 AM AS A TROUGH OF LOW PRESSURE PUSHES INTO THE PLAINS. LOOK FOR THE CLOUDS TO CONTINUE LOWERING...BUT REMAINING IN VFR RANGE THROUGH MONDAY MORNING AS THE TROUGH PUSHES OUT OF THE PLAINS TOWARD THE AREA. KRST COULD BE RIGHT ON THE CUSP OF DETERIORATING INTO MVFR RANGE BY 17Z MONDAY...AND WILL LIKELY BECOME MVFR/POSSIBLY IFR AT BOTH KRST/KLSE DURING THE AFTERNOON AS -SN WORKS INTO THE AREA WITH THE APPROACHING TROUGH. && .ARX WATCHES/WARNINGS/ADVISORIES... 206 AM CST SUN FEB 12 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
540 AM CST SUN FEB 12 2012 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT 206 AM CST SUN FEB 12 2012 MAIN FORECAST CONCERN IS ON LIGHT SNOW FOR MONDAY INTO MONDAY NIGHT CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER SOUTHWEST INTO SOUTH CENTRAL CANADA...AS WELL AS OVER TEXAS INTO COLORADO...A SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST...A DEEPER SHORTWAVE TROUGH OVER THE DESERT SOUTHWEST... AND A LONG-WAVE TROUGH ALONG THE EASTERN SEABOARD. WITH 500MB HEIGHTS RISING OVER THE FORECAST AREA BEHIND THE LONG-WAVE TROUGH...WARMER AIR ALOFT IS BEGINNING TO FLOW IN FROM CENTRAL CANADA. INTERESTING THAT BETWEEN 00Z ON THE 10TH AND 00Z ON THE 12TH...850MB TEMPS HAVE WARMED ABOUT 16C ACROSS MUCH OF CENTRAL CANADA PER 00Z RAOBS. IN FACT...850MB TEMPS AT 00Z WERE -3C AT CHURCHILL MANITOBA...WARMER THAN THE AVERAGE -13C OVER THE FORECAST AREA. AIRMASS REMAINS DRY ACROSS THE ENTIRE UPPER MIDWEST...CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY REGIONS...NOTED BY PRECIPITABLE WATER VALUES BETWEEN 0.05-0.1 INCHES ON 00Z SOUNDINGS. THIS DRY AIR IS ASSOCIATED WITH AN AREA OF HIGH PRESSURE AT THE SURFACE THAT ENCOMPASSES ALL OF THE U.S. PLAINS. A SUSTAINED 5 TO 15 MPH NORTHWEST WIND OVER THE FORECAST AREA...ON THE EAST SIDE OF HIGH... HAS ONLY ALLOWED TEMPERATURES TO FALL INTO THE 8 TO 15F RANGE. TODAY AND TONIGHT...THE UPPER RIDGING SEEN FROM TEXAS INTO COLORADO IS PROGGED TO LIFT NORTHEAST TOWARDS THE AREA DURING THIS PERIOD...IN RESPONSE TO THE TWO SHORTWAVE TROUGHS OUT WEST MOVING OUT INTO THE WESTERN PLAINS. MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO AND DPVA AHEAD OF THESE TROUGHS SHOULD CAUSE PRECIPITATION TO BREAK OUT ACROSS MUCH OF THE PLAINS TONIGHT...PERHAPS REACHING INTO WESTERN IOWA LATE IN THE NIGHT. FOR OUR AREA...WE WILL REMAIN INFLUENCED BY THE DRY AIR ASSOCIATED WITH THE SURFACE HIGH...AND ITS RIDGE AXIS LOOKS TO CROSS TONIGHT. FULL SUN ANTICIPATED TODAY AND WITH 850MB TEMPS PROGGED AROUND -6C AT 18Z...TEMPERATURES SHOULD CLIMB INTO THE MID 20S TO NEAR 30. WILL STILL BE DEALING WITH A NORTHWEST TO WESTERLY BREEZE...BUT IT DOES NOT LOOK AS BREEZY AS YESTERDAY WITH A WEAKER PRESSURE GRADIENT PROGGED. THE WINDS MAY HAVE A SHOT OF DECOUPLING TONIGHT...ESPECIALLY OVER WESTERN WISCONSIN...SETTING UP BETTER RADIATIONAL COOLING. ON THE FLIP SIDE...A WARMER DAY TODAY WILL PROBABLY END UP RESULTING IN LOWS SIMILAR TO THOSE EXPERIENCED THIS MORNING. INCREASING MID/HIGH CLOUDS LATER IN THE NIGHT WEST OF THE MISSISSIPPI RIVER SHOULD KEEP TEMPERATURES A LITTLE WARMER THERE. MONDAY AND MONDAY NIGHT...MODELS ARE IN GOOD AGREEMENT TAKING THE TROUGHING OVER THE WESTERN PLAINS AT 12Z MONDAY MOSTLY INTO THE OHIO VALLEY REGION MONDAY NIGHT. THERE IS A NORTHERN EXTENSION THAT CROSSES THE FORECAST AREA LATE MONDAY INTO THE EARLY OVERNIGHT HOURS MONDAY NIGHT. WITH THE BULK OF THE TROUGH HEADING MORE TO THE SOUTH...THERE IS CONCERN ON HOW MUCH MOISTURE CAN MAKE IT NORTH INTO THE FORECAST AREA. CERTAINLY MODELS SUGGEST IT HAPPENS ENOUGH TO PRODUCE SOME LIGHT QPF ACROSS MUCH OF THE FORECAST AREA...THOUGH THE BEST MOISTURE TRANSPORT AND ISENTROPIC LIFT STAYS TO THE SOUTH AND EAST. SO BASICALLY THE HEIGHT FALLS AND DPVA FROM THE NORTHERN EXTENSION OF THE TROUGH WILL BE THE MAIN FORCING FUNCTION FOR THE PRECIPITATION. LOOKS LIKE PRECIPITATION SHOULD SLOWLY WORK SOUTHWEST TO NORTHEAST ACROSS THE AREA ON MONDAY...WITH THE LINGERING DRY AIR THE MAIN REASON FOR THE SLOW ADVANCEMENT. PRECIPITATION THEN DIMINISHES WEST TO EAST AFTER MIDNIGHT MONDAY NIGHT AS THE TROUGH PUSHES EAST. GOOD MODEL AGREEMENT REMAINS ON THIS LIGHT PRECIPITATION EVENT...SO HAVING THE HIGH PRECIPITATION CHANCES AS INDICATED BY THE PREVIOUS FORECAST SEEM REASONABLE. ONLY SLIGHT UPWARD MODIFICATIONS WERE MADE. WITH RESPECT TO AMOUNTS...THINK THE 12.00Z NAM IS A LITTLE TOO HIGH ON QPF GIVEN WEAK FORCING OVERALL. SHOULD MAINLY BE A 0.5 TO 1.5 INCH SNOW EVENT...WITH PERHAPS A FEW TOTALS SLIGHTLY HIGHER THAN THAT. WITH A FLOW OF WARMER AIR COMING IN WITH THE TROUGH...SLIGHTLY HIGHER HIGHS ARE ANTICIPATED FOR MONDAY COMPARED TO TODAY. IN FACT...AREAS ACROSS WISCONSIN COULD EVEN SEE SOME SUN IN THE MORNING. CLOUDY SKIES ARE EXPECTED ACROSS THE AREA MONDAY NIGHT...AND WITH LITTLE OR NO COLD ADVECTION...TEMPERATURES SHOULD ONLY DROP MAYBE 5 DEGREES FOR LOWS. TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THE MONDAY/MONDAY TROUGH...MODELS SHOW ONE MORE SHORTWAVE MOVING WEST TO EAST ACROSS THE FORECAST AREA LATE TUESDAY. APPEARS THIS SHORTWAVE WILL NOT HAVE MUCH MOISTURE OR EVEN PRODUCE MUCH FORCING...THEREFORE HAVE DRY CONDITIONS FOR TUESDAY. ON TUESDAY NIGHT...TROUGHING IS FORECAST TO DROP DOWN INTO MANITOBA WHILE TROUGHING IS SHOWN AGAIN OVER THE SOUTHWESTERN U.S.. HOWEVER...NEITHER FEATURE IS CLOSE ENOUGH TO BRING ANY PRECIPITATION TO THE AREA. IN FACT...THERE SHOULD BE SOME SLIGHT 500MB HEIGHT RISES TAKING PLACE. THEREFORE...DRY CONDITIONS CONTINUE. 850MB TEMPS PROGGED AROUND -6C ON TUESDAY COMBINED WITH SOME SLOW CLEARING AND A WARMER START WILL ALLOW FOR HIGHS A FEW DEGREES WARMER THAN MONDAY. A LITTLE BETTER NIGHT INDICATED FOR RADIATIONAL COOLING TUESDAY NIGHT WITH LIGHT WINDS...THOUGH THE AIRMASS OVERALL IS RELATIVELY SPEAKING WARM WITH 850MB TEMPS HOLDING NEARLY STEADY. IN ADDITION...THERE ARE HINTS OF SOME STRATUS TO MOVE IN LATER IN THE NIGHT. FOR NOW...FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT 206 AM CST SUN FEB 12 2012 12.00Z MODELS (ECMWF/CANADIAN/UKMET/GFS/GFS ENSEMBLES) DEPICT A MESSY UPPER LEVEL FLOW PATTERN THROUGHOUT THE LONG TERM...RESULTING IN QUITE A FEW DIFFERENCES BETWEEN ALL THE MODELS. IT APPEARS THIS IS A RESULT OF A FAST...ZONAL FLOW ACROSS THE PACIFIC RUNNING INTO SPLIT FLOW OVER THE U.S. AND SOUTHERN CANADA. DESPITE THE DIFFERENCES OF HANDLING SHORTWAVES...IN GENERAL THE LONG TERM PERIOD LOOKS PRETTY QUIET WITH ALL OF THE COLD...ARCTIC AIR BEING LOCKED UP OVER VERY FAR NORTHERN CANADA. THERE ARE A FEW FEATURES THAT MODELS AGREE UPON AND WILL DISCUSS THEM HERE. THE FIRST IS THE TROUGHING THAT DEVELOPS OVER THE SOUTHWESTERN U.S. TUESDAY NIGHT. 12.00Z ECMWF/GFS/UKMET ARE ALL IN AGREEMENT ON SHEARING THIS TROUGH OUT AND TRACKING IT THROUGH THE OHIO VALLEY ON THURSDAY. THIS TRACK AND GIVEN THE FACT THAT IS SHEARING WOULD KEEP THE BULK OF THE PRECIPITATION SOUTH OF THE FORECAST AREA...OR PERHAPS CLIP NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE 12.00Z CANADIAN IS THE ONLY MODEL NOW STILL SUGGESTING A FARTHER NORTH...MORE PHASED LOOK... WHICH RESULTS IN A DEEPER SYSTEM SPREADING PRECIPITATION OVER MUCH OF THE AREA WEDNESDAY NIGHT INTO THURSDAY. HAVE LOWERED PRECIPITATION CHANCES SOME DURING THIS PERIOD GIVEN THE TREND TO THE UN-PHASED LOOK...AND STILL WOULD NOT BE SURPRISED IF IT ENDS UP DRY LIKE THE 12.00Z GFS SHOWS. UPPER LEVEL TROUGHING DOES DEVELOP OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION EASTWARD INTO NEW ENGLAND FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT. 850MB TEMPS ARE ONLY AROUND -4C IN THE TROUGH SO AGAIN...NOTHING THAT COLD. FLOW THEN TURNS MORE ZONAL FOR SATURDAY OVER THE AREA WITH NO PRECIPITATION SEEN. SO OUTSIDE OF THE WEDNESDAY NIGHT/THURSDAY TIME PERIOD...A DRY LONG TERM FORECAST IS EXPECTED. NO BIG WARM-UPS PLANNED EITHER. HOWEVER...GIVEN 850MB TEMPS STAYING MOSTLY BETWEEN -4C AND 1C... SURFACE TEMPERATURES SHOULD AT LEAST END UP 5-10 DEGREES NORMAL FOR BOTH HIGHS AND LOWS. LOOKING FARTHER OUT INTO EARLY NEXT WEEK...STILL NO SUGGESTIONS OF ANY MAJOR COOL DOWNS AS THE FAST PACIFIC FLOW CONTINUES...ALLOWING PACIFIC AIR TO CONTINUE TO FLOW ACROSS THE U.S. && .AVIATION...TODAY AND TONIGHT 545 AM CST SUN FEB 12 2012 HIGH PRESSURE WILL CONTINUE TO PROVIDE CLEAR SKIES THROUGH THIS EVENING...AND THEN A SCATTERED TO BROKEN CIRROSTRATUS DECK WILL MOVE INTO THE AREA AFTER 13.09Z. THE WIND DIRECTION WILL BE PRIMARILY WEST TODAY AND THEN GRADUALLY SHIFT TO SOUTH TONIGHT. WIND SPEEDS THROUGH THE PERIOD WILL BE 10 KNOTS OR LESS. && .ARX WATCHES/WARNINGS/ADVISORIES... 206 AM CST SUN FEB 12 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
206 AM CST SUN FEB 12 2012 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT 206 AM CST SUN FEB 12 2012 MAIN FORECAST CONCERN IS ON LIGHT SNOW FOR MONDAY INTO MONDAY NIGHT CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER SOUTHWEST INTO SOUTH CENTRAL CANADA...AS WELL AS OVER TEXAS INTO COLORADO...A SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST...A DEEPER SHORTWAVE TROUGH OVER THE DESERT SOUTHWEST... AND A LONG-WAVE TROUGH ALONG THE EASTERN SEABOARD. WITH 500MB HEIGHTS RISING OVER THE FORECAST AREA BEHIND THE LONG-WAVE TROUGH...WARMER AIR ALOFT IS BEGINNING TO FLOW IN FROM CENTRAL CANADA. INTERESTING THAT BETWEEN 00Z ON THE 10TH AND 00Z ON THE 12TH...850MB TEMPS HAVE WARMED ABOUT 16C ACROSS MUCH OF CENTRAL CANADA PER 00Z RAOBS. IN FACT...850MB TEMPS AT 00Z WERE -3C AT CHURCHILL MANITOBA...WARMER THAN THE AVERAGE -13C OVER THE FORECAST AREA. AIRMASS REMAINS DRY ACROSS THE ENTIRE UPPER MIDWEST...CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY REGIONS...NOTED BY PRECIPITABLE WATER VALUES BETWEEN 0.05-0.1 INCHES ON 00Z SOUNDINGS. THIS DRY AIR IS ASSOCIATED WITH AN AREA OF HIGH PRESSURE AT THE SURFACE THAT ENCOMPASSES ALL OF THE U.S. PLAINS. A SUSTAINED 5 TO 15 MPH NORTHWEST WIND OVER THE FORECAST AREA...ON THE EAST SIDE OF HIGH... HAS ONLY ALLOWED TEMPERATURES TO FALL INTO THE 8 TO 15F RANGE. TODAY AND TONIGHT...THE UPPER RIDGING SEEN FROM TEXAS INTO COLORADO IS PROGGED TO LIFT NORTHEAST TOWARDS THE AREA DURING THIS PERIOD...IN RESPONSE TO THE TWO SHORTWAVE TROUGHS OUT WEST MOVING OUT INTO THE WESTERN PLAINS. MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO AND DPVA AHEAD OF THESE TROUGHS SHOULD CAUSE PRECIPITATION TO BREAK OUT ACROSS MUCH OF THE PLAINS TONIGHT...PERHAPS REACHING INTO WESTERN IOWA LATE IN THE NIGHT. FOR OUR AREA...WE WILL REMAIN INFLUENCED BY THE DRY AIR ASSOCIATED WITH THE SURFACE HIGH...AND ITS RIDGE AXIS LOOKS TO CROSS TONIGHT. FULL SUN ANTICIPATED TODAY AND WITH 850MB TEMPS PROGGED AROUND -6C AT 18Z...TEMPERATURES SHOULD CLIMB INTO THE MID 20S TO NEAR 30. WILL STILL BE DEALING WITH A NORTHWEST TO WESTERLY BREEZE...BUT IT DOES NOT LOOK AS BREEZY AS YESTERDAY WITH A WEAKER PRESSURE GRADIENT PROGGED. THE WINDS MAY HAVE A SHOT OF DECOUPLING TONIGHT...ESPECIALLY OVER WESTERN WISCONSIN...SETTING UP BETTER RADIATIONAL COOLING. ON THE FLIP SIDE...A WARMER DAY TODAY WILL PROBABLY END UP RESULTING IN LOWS SIMILAR TO THOSE EXPERIENCED THIS MORNING. INCREASING MID/HIGH CLOUDS LATER IN THE NIGHT WEST OF THE MISSISSIPPI RIVER SHOULD KEEP TEMPERATURES A LITTLE WARMER THERE. MONDAY AND MONDAY NIGHT...MODELS ARE IN GOOD AGREEMENT TAKING THE TROUGHING OVER THE WESTERN PLAINS AT 12Z MONDAY MOSTLY INTO THE OHIO VALLEY REGION MONDAY NIGHT. THERE IS A NORTHERN EXTENSION THAT CROSSES THE FORECAST AREA LATE MONDAY INTO THE EARLY OVERNIGHT HOURS MONDAY NIGHT. WITH THE BULK OF THE TROUGH HEADING MORE TO THE SOUTH...THERE IS CONCERN ON HOW MUCH MOISTURE CAN MAKE IT NORTH INTO THE FORECAST AREA. CERTAINLY MODELS SUGGEST IT HAPPENS ENOUGH TO PRODUCE SOME LIGHT QPF ACROSS MUCH OF THE FORECAST AREA...THOUGH THE BEST MOISTURE TRANSPORT AND ISENTROPIC LIFT STAYS TO THE SOUTH AND EAST. SO BASICALLY THE HEIGHT FALLS AND DPVA FROM THE NORTHERN EXTENSION OF THE TROUGH WILL BE THE MAIN FORCING FUNCTION FOR THE PRECIPITATION. LOOKS LIKE PRECIPITATION SHOULD SLOWLY WORK SOUTHWEST TO NORTHEAST ACROSS THE AREA ON MONDAY...WITH THE LINGERING DRY AIR THE MAIN REASON FOR THE SLOW ADVANCEMENT. PRECIPITATION THEN DIMINISHES WEST TO EAST AFTER MIDNIGHT MONDAY NIGHT AS THE TROUGH PUSHES EAST. GOOD MODEL AGREEMENT REMAINS ON THIS LIGHT PRECIPITATION EVENT...SO HAVING THE HIGH PRECIPITATION CHANCES AS INDICATED BY THE PREVIOUS FORECAST SEEM REASONABLE. ONLY SLIGHT UPWARD MODIFICATIONS WERE MADE. WITH RESPECT TO AMOUNTS...THINK THE 12.00Z NAM IS A LITTLE TOO HIGH ON QPF GIVEN WEAK FORCING OVERALL. SHOULD MAINLY BE A 0.5 TO 1.5 INCH SNOW EVENT...WITH PERHAPS A FEW TOTALS SLIGHTLY HIGHER THAN THAT. WITH A FLOW OF WARMER AIR COMING IN WITH THE TROUGH...SLIGHTLY HIGHER HIGHS ARE ANTICIPATED FOR MONDAY COMPARED TO TODAY. IN FACT...AREAS ACROSS WISCONSIN COULD EVEN SEE SOME SUN IN THE MORNING. CLOUDY SKIES ARE EXPECTED ACROSS THE AREA MONDAY NIGHT...AND WITH LITTLE OR NO COLD ADVECTION...TEMPERATURES SHOULD ONLY DROP MAYBE 5 DEGREES FOR LOWS. TUESDAY AND TUESDAY NIGHT...IN THE WAKE OF THE MONDAY/MONDAY TROUGH...MODELS SHOW ONE MORE SHORTWAVE MOVING WEST TO EAST ACROSS THE FORECAST AREA LATE TUESDAY. APPEARS THIS SHORTWAVE WILL NOT HAVE MUCH MOISTURE OR EVEN PRODUCE MUCH FORCING...THEREFORE HAVE DRY CONDITIONS FOR TUESDAY. ON TUESDAY NIGHT...TROUGHING IS FORECAST TO DROP DOWN INTO MANITOBA WHILE TROUGHING IS SHOWN AGAIN OVER THE SOUTHWESTERN U.S.. HOWEVER...NEITHER FEATURE IS CLOSE ENOUGH TO BRING ANY PRECIPITATION TO THE AREA. IN FACT...THERE SHOULD BE SOME SLIGHT 500MB HEIGHT RISES TAKING PLACE. THEREFORE...DRY CONDITIONS CONTINUE. 850MB TEMPS PROGGED AROUND -6C ON TUESDAY COMBINED WITH SOME SLOW CLEARING AND A WARMER START WILL ALLOW FOR HIGHS A FEW DEGREES WARMER THAN MONDAY. A LITTLE BETTER NIGHT INDICATED FOR RADIATIONAL COOLING TUESDAY NIGHT WITH LIGHT WINDS...THOUGH THE AIRMASS OVERALL IS RELATIVELY SPEAKING WARM WITH 850MB TEMPS HOLDING NEARLY STEADY. IN ADDITION...THERE ARE HINTS OF SOME STRATUS TO MOVE IN LATER IN THE NIGHT. FOR NOW...FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT 206 AM CST SUN FEB 12 2012 12.00Z MODELS (ECMWF/CANADIAN/UKMET/GFS/GFS ENSEMBLES) DEPICT A MESSY UPPER LEVEL FLOW PATTERN THROUGHOUT THE LONG TERM...RESULTING IN QUITE A FEW DIFFERENCES BETWEEN ALL THE MODELS. IT APPEARS THIS IS A RESULT OF A FAST...ZONAL FLOW ACROSS THE PACIFIC RUNNING INTO SPLIT FLOW OVER THE U.S. AND SOUTHERN CANADA. DESPITE THE DIFFERENCES OF HANDLING SHORTWAVES...IN GENERAL THE LONG TERM PERIOD LOOKS PRETTY QUIET WITH ALL OF THE COLD...ARCTIC AIR BEING LOCKED UP OVER VERY FAR NORTHERN CANADA. THERE ARE A FEW FEATURES THAT MODELS AGREE UPON AND WILL DISCUSS THEM HERE. THE FIRST IS THE TROUGHING THAT DEVELOPS OVER THE SOUTHWESTERN U.S. TUESDAY NIGHT. 12.00Z ECMWF/GFS/UKMET ARE ALL IN AGREEMENT ON SHEARING THIS TROUGH OUT AND TRACKING IT THROUGH THE OHIO VALLEY ON THURSDAY. THIS TRACK AND GIVEN THE FACT THAT IS SHEARING WOULD KEEP THE BULK OF THE PRECIPITATION SOUTH OF THE FORECAST AREA...OR PERHAPS CLIP NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE 12.00Z CANADIAN IS THE ONLY MODEL NOW STILL SUGGESTING A FARTHER NORTH...MORE PHASED LOOK... WHICH RESULTS IN A DEEPER SYSTEM SPREADING PRECIPITATION OVER MUCH OF THE AREA WEDNESDAY NIGHT INTO THURSDAY. HAVE LOWERED PRECIPITATION CHANCES SOME DURING THIS PERIOD GIVEN THE TREND TO THE UN-PHASED LOOK...AND STILL WOULD NOT BE SURPRISED IF IT ENDS UP DRY LIKE THE 12.00Z GFS SHOWS. UPPER LEVEL TROUGHING DOES DEVELOP OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION EASTWARD INTO NEW ENGLAND FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT. 850MB TEMPS ARE ONLY AROUND -4C IN THE TROUGH SO AGAIN...NOTHING THAT COLD. FLOW THEN TURNS MORE ZONAL FOR SATURDAY OVER THE AREA WITH NO PRECIPITATION SEEN. SO OUTSIDE OF THE WEDNESDAY NIGHT/THURSDAY TIME PERIOD...A DRY LONG TERM FORECAST IS EXPECTED. NO BIG WARM-UPS PLANNED EITHER. HOWEVER...GIVEN 850MB TEMPS STAYING MOSTLY BETWEEN -4C AND 1C... SURFACE TEMPERATURES SHOULD AT LEAST END UP 5-10 DEGREES NORMAL FOR BOTH HIGHS AND LOWS. LOOKING FARTHER OUT INTO EARLY NEXT WEEK...STILL NO SUGGESTIONS OF ANY MAJOR COOL DOWNS AS THE FAST PACIFIC FLOW CONTINUES...ALLOWING PACIFIC AIR TO CONTINUE TO FLOW ACROSS THE U.S. && .AVIATION...THROUGH 06Z MONDAY 1055 PM CST SAT FEB 11 2012 HIGH PRESSURE WILL REMAIN THE MAIN WEATHER FEATURE THROUGH SUNDAY...SHIFTING SOUTHEAST TO THE GULF STATES BY 06Z MON. WITH THE CENTER OF THE HIGH STAYING JUST WEST AND SOUTH...THERE WILL BE A PRESSURE GRADIENT KEEPING THE WINDS UP. EXPECT NORTHWEST-WEST WINDS AROUND 10 KTS...BECOMING MORE SOUTHWEST-SOUTH SUNDAY NIGHT. OTHERWISE...LOOK FOR MOSTLY CLEAR/VFR CONDITIONS. SOME CLOUDS WILL BE ON THE RETURN OVERNIGHT SUNDAY AS AN UPPER LEVEL TROUGH APPROACHES FROM THE PLAINS. CIGS WILL LOWER MONDAY...LIKELY MVFR...WITH -SN ALSO MOVING IN. LOOK FOR VSBY RESTRICTIONS WITH THE -SN WITH ACCUMULATIONS UP TO AN INCH POSSIBLE. && .ARX WATCHES/WARNINGS/ADVISORIES... 206 AM CST SUN FEB 12 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1250 AM EST TUE FEB 14 2012 .UPDATE... ISSUED AT 1117 PM EST MON FEB 13 2012 JUST A QUICK UPDATE TO PUSH POPS A BIT FURTHER NORTH AS PCPN HAS GOTTEN FURTHER NORTH THAN PREVIOUS THINKING. IT HAS GOTTEN UP TO LNL...IMT...ESC AND ISQ NOW. SHOULD NOT GET TOO MUCH FURTHER NORTH AS IT IS BATTLING SOME DRIER AIR. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 400 PM EST MON FEB 13 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL SHORTWAVE TROUGH MOVING FROM THE CNTRL PLAINS TOWARD THE MID MS VALLEY AND CONFLUENT FLOW FROM NRN ONTARIO INTO THE NRN LAKES ON THE PERIPHERY OF THE DEEP TROUGH OVER ERN CANADA. LIGHT SNOW ASSOCIATED WITH THE SHRTWV HAD ADVANCED INTO SRN WI. AT THE SFC...SRLY FLOW PREVAILED FROM MO/IA INTO WI UPPER MI AHEAD OF A TROUGH OVER THE PLAINS. VIS LOOP SHOWED MID CLOUDS HAD SPREAD FROM NRN WI THROUGH THE SW HALF OF UPPER MI WITH LOW/MID LEVEL MOISTURE ADVECTION AHEAD OF THE LOW. TONIGHT INTO TUESDAY...EXPECT CLOUDS TO SPREAD ACROSS THE REST OF THE CWA LATE THIS AFTERNOON AND PERSIST THROUGH TUESDAY...PER SATELLITE TRENDS AND NAM/GFS SFC-850 RH FCST. ALTHOUGH THE PCPN OVER SRN WI CONTINUED TO SPREAD TO THE NORTH...WITH ONLY VERY WEAK FORCING QVECTOR CONV...FGEN OR ISENTROPIC LIFT...ANY LIGHT SNOW MOVING INTO THE AREA SHOULD BE VERY LIGHT AND BE CONFINED TO THE FAR SOUTH CWA (SOUTH OF US-2)...PER GFS/ECMWF AND REGIONAL GEM. CLOUDS WILL HOLD TEMPS UP TONIGHT WITH MIN READINGS MAINLY IN THE 20S. WITH THE RELATIVELY MILD AIRMASS LINGERING OVER THE AREA TUESDAY...MAX READINGS SHOULD STILL CLIMB INTO THE LOWER TO MID 30S...DESPITE THE LINGERING CLOUDS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 400 PM EST MON FEB 13 2012 WED THRU MON...UNDER SPLIT FLOW REGIME...ARCTIC AIR WILL BE BOTTLED UP WELL TO THE N INTO NEXT WEEKEND...RESULTING IN TEMPS CONTINUING TO AVERAGE ABOVE NORMAL. MODELS HINT AT A WEAK SHORTWAVE TO PASS OVER THE UPPER GREAT LAKES WEDNESDAY. HOWEVER...MID AND UPPER LEVEL DRY AIR ALONG WITH VERY LITTLE LIFT WILL KEEP MUCH OF UPPER MI PREDOMINATELY DRY DURING THIS TIME FRAME. CENTRALIZED SHORTWAVE TRAVERSING CALIFORNIA DURING THE DAY TODAY WILL SLOWLY MOVE E TO THE CENTRAL PLAINS THROUGH WEDNESDAY...THEN SHIFT TO A MORE NW DIRECTION...REACHING LAKE MI BY 12Z THURSDAY. SOME MEDIUM RANGE MODELS ARE ALSO POINTING AT THE POTENTIAL FOR NRN STREAM ENERGY TO PHASE WITH AND POSSIBLY STRENGTHEN THIS SRN STREAM SYSTEM AS IT NEARS THE GREAT LAKES REGION. MODEL CONSENSUS KEEPS MOST OF THE PRECIP CENTERED ALONG EASTERN EDGE OF THE PRESSURE SYSTEM WHERE THE DEEPEST QVECTOR CONV/LIFT WILL BE LOCATED...AS WELL AS ALONG THE ADJOINING COLD FRONT TO THE SOUTH. SOME OF THIS DEEP MOISTURE AND QVECTOR CONV COULD REACH SC AND E UPPER MI DURING THE DAY THURSDAY...ESPECIALLY AS SYSTEM BECOMES MORE WRAPPED UP. MODELS HINT AT A TROWEL DEVELOPING...PULLING THE COLD FRONT ACROSS SOUTHERN MENOMINEE COUNTY AND CENTRAL WI ALONG WITH 0.25 TO 0.5 INCH QPF VALUES. THIS HAS BEEN CONSISTENT IN THE PREVIOUS TWO RUNS OF THE GFS/ECMWF/AND NAM...THOUGH LATEST 13/12Z GFS AND GEM SEEMED TO PUSH PRECIP FARTHER SOUTH. AS A RESULT...HAVE CONTINUED WITH EARLIER CONSENSUS RUNS AND INCREASED POPS AND QPF ACROSS THE CWA. LATEST MODEL RUNS ALSO SHOW COLDER 850 TEMPERATURE TRENDS...WHILE SURFACE TEMPS WILL REMAIN RIGHT AT FREEZING...SO EXPECT SNOW TO BE THE MAIN PRECIP TYPE. WILL CONTINUE TO MONITOR LATEST MODEL RUNS FOR ANY CHANGE IN PLACEMENTS/WIND DIRECTIONS AND RESULTING PRECIP TYPES/LOCATIONS. MIDLEVEL DRY AIR AHEAD OF APPROACHING RIDGE WILL THEN CUT IN BY THURSDAY NIGHT AS SHORTWAVE MOVES OFF TO THE NORTHEAST...REDUCING PRECIP CHANCES FROM WEST TO EAST OVERNIGHT. THE RESULT OF THIS UPPER LEVEL RIDGING WILL BE TO TURN WINDS MORE NORTHWESTERLY BY FRIDAY INTO SATURDAY...ALLOWING ARCTIC AIR TO PENETRATE SOUTHWARD ACROSS THE GREAT LAKES. 13/12Z GFS HAS H850 TEMPS DROPPING TO -17C SATURDAY. THIS...ALONG WITH LINGERING LOW LEVEL MOISTURE...WILL CREATE THE CONVERGENCE NEEDED FOR LAKE EFFECT SNOW FRIDAY THROUGH SATURDAY IN AREAS ALONG LAKE SUPERIOR FAVORED BY NW WINDS. 13/12Z ECMWF ALSO KEEPS WITH THIS TREND...THOUGH FALLING TEMPERATURES AND AMOUNT OF CONVERGENCE ARE SLIGHTLY LESS MAGNIFIED. AS A RESULT...HAVE INCREASED SLIGHT CHANCE TO CHANCE POPS ALONG LAKE SUPERIOR IN AREAS FAVORED BY A NW WIND DIRECTION...KEEPING WITH PREVIOUS FORECASTS. ANY LINGERING LES EAST WILL COME TO AN END LATE SATURDAY...AS WINDS BECOME MORE SOUTHWESTERLY...AHEAD OF THE NEXT SFC LOW/500MB TROUGH APPROACHING FROM CENTRAL CANADA AND MN. THERE ARE SIGNIFICANT ENOUGH TIMING DIFFERENCE TO RESULT IN MODERATE CONFIDENCE IN THE FCST BEYOND THIS PERIOD. WHILE THE GFS AND ECMWF ARE IN FAIRLY GOOD SHAPE UP UNTIL THIS POINT...THE 13/06Z RUN OF THE GFS BECOMES ROUGHLY 12 HRS SLOWER THAN THE MORE CONSISTENT ECMWF WITH THE HANDLING OF THIS WAVE /CENTERED ACROSS THE UPPER GREAT LAKES AT 00Z MONDAY...WHILE THE ECMWF HAS IT OVER THE LOWER GREAT LAKES/. WHILE THE ECMWF INDICATES A DRY FRONTAL PASSAGE WITH THE SFC LOW CENTERED OVER NORTHERN ONTARIO. GIVEN THE SLOWER AND MORE SOUTHERN GFS...A BROAD SFC LOW WILL LIKELY DEVELOP OVER THE GREAT LAKES...WITH LIGHT PRECIP AND PLENTY OF CLOUD COVER BEFORE THE SYSTEM EJECTS EASTWARD MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1249 AM EST TUE FEB 14 2012 A DISTURBANCE MOVING FROM THE CNTRAL PLAINS TO THE LOWER GREAT LAKES WILL CONTINUE TO HAVE THE LOWER CLOUDS LOWER THROUGH THE NIGHT AND LIKELY BE IN THE MVFR CAT AFTER 09Z AT ALL SITES. ONCE THESE CLOUDS ARE IN THE MVFR CIG RANGE...THEY WILL STAY THROUGH THE FORECAST PERIOD AT ALL SITES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 400 PM EST MON FEB 13 2012 A HIGH PRESSURE RIDGE BUILDING OVER THE AREA WILL KEEP WINDS BELOW 20KTS TONIGHT THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS ON WED NIGHT WILL MOVE THROUGH THE GREAT LAKES REGION FROM THURSDAY INTO FRIDAY. THIS WILL LEAD TO NW WINDS UP TO 25KTS OVER ERN LK SUPERIOR. HIGH PRESSURE WILL THEN MOVE OVER THE AREA FOR THE FIRST PART OF THE WEEKEND AND KEEP WINDS BELOW 20KTS. WITH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...LITTLE TO NO FREEZING SPRAY IS EXPECTED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...07 SHORT TERM...JLB LONG TERM...JMW AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1117 PM EST MON FEB 13 2012 .UPDATE... ISSUED AT 1117 PM EST MON FEB 13 2012 JUST A QUICK UPDATE TO PUSH POPS A BIT FURTHER NORTH AS PCPN HAS GOTTEN FURTHER NORTH THAN PREVIOUS THINKING. IT HAS GOTTEN UP TO LNL...IMT...ESC AND ISQ NOW. SHOULD NOT GET TOO MUCH FURTHER NORTH AS IT IS BATTLING SOME DRIER AIR. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 400 PM EST MON FEB 13 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL SHORTWAVE TROUGH MOVING FROM THE CNTRL PLAINS TOWARD THE MID MS VALLEY AND CONFLUENT FLOW FROM NRN ONTARIO INTO THE NRN LAKES ON THE PERIPHERY OF THE DEEP TROUGH OVER ERN CANADA. LIGHT SNOW ASSOCIATED WITH THE SHRTWV HAD ADVANCED INTO SRN WI. AT THE SFC...SRLY FLOW PREVAILED FROM MO/IA INTO WI UPPER MI AHEAD OF A TROUGH OVER THE PLAINS. VIS LOOP SHOWED MID CLOUDS HAD SPREAD FROM NRN WI THROUGH THE SW HALF OF UPPER MI WITH LOW/MID LEVEL MOISTURE ADVECTION AHEAD OF THE LOW. TONIGHT INTO TUESDAY...EXPECT CLOUDS TO SPREAD ACROSS THE REST OF THE CWA LATE THIS AFTERNOON AND PERSIST THROUGH TUESDAY...PER SATELLITE TRENDS AND NAM/GFS SFC-850 RH FCST. ALTHOUGH THE PCPN OVER SRN WI CONTINUED TO SPREAD TO THE NORTH...WITH ONLY VERY WEAK FORCING QVECTOR CONV...FGEN OR ISENTROPIC LIFT...ANY LIGHT SNOW MOVING INTO THE AREA SHOULD BE VERY LIGHT AND BE CONFINED TO THE FAR SOUTH CWA (SOUTH OF US-2)...PER GFS/ECMWF AND REGIONAL GEM. CLOUDS WILL HOLD TEMPS UP TONIGHT WITH MIN READINGS MAINLY IN THE 20S. WITH THE RELATIVELY MILD AIRMASS LINGERING OVER THE AREA TUESDAY...MAX READINGS SHOULD STILL CLIMB INTO THE LOWER TO MID 30S...DESPITE THE LINGERING CLOUDS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 400 PM EST MON FEB 13 2012 WED THRU MON...UNDER SPLIT FLOW REGIME...ARCTIC AIR WILL BE BOTTLED UP WELL TO THE N INTO NEXT WEEKEND...RESULTING IN TEMPS CONTINUING TO AVERAGE ABOVE NORMAL. MODELS HINT AT A WEAK SHORTWAVE TO PASS OVER THE UPPER GREAT LAKES WEDNESDAY. HOWEVER...MID AND UPPER LEVEL DRY AIR ALONG WITH VERY LITTLE LIFT WILL KEEP MUCH OF UPPER MI PREDOMINATELY DRY DURING THIS TIME FRAME. CENTRALIZED SHORTWAVE TRAVERSING CALIFORNIA DURING THE DAY TODAY WILL SLOWLY MOVE E TO THE CENTRAL PLAINS THROUGH WEDNESDAY...THEN SHIFT TO A MORE NW DIRECTION...REACHING LAKE MI BY 12Z THURSDAY. SOME MEDIUM RANGE MODELS ARE ALSO POINTING AT THE POTENTIAL FOR NRN STREAM ENERGY TO PHASE WITH AND POSSIBLY STRENGTHEN THIS SRN STREAM SYSTEM AS IT NEARS THE GREAT LAKES REGION. MODEL CONSENSUS KEEPS MOST OF THE PRECIP CENTERED ALONG EASTERN EDGE OF THE PRESSURE SYSTEM WHERE THE DEEPEST QVECTOR CONV/LIFT WILL BE LOCATED...AS WELL AS ALONG THE ADJOINING COLD FRONT TO THE SOUTH. SOME OF THIS DEEP MOISTURE AND QVECTOR CONV COULD REACH SC AND E UPPER MI DURING THE DAY THURSDAY...ESPECIALLY AS SYSTEM BECOMES MORE WRAPPED UP. MODELS HINT AT A TROWEL DEVELOPING...PULLING THE COLD FRONT ACROSS SOUTHERN MENOMINEE COUNTY AND CENTRAL WI ALONG WITH 0.25 TO 0.5 INCH QPF VALUES. THIS HAS BEEN CONSISTENT IN THE PREVIOUS TWO RUNS OF THE GFS/ECMWF/AND NAM...THOUGH LATEST 13/12Z GFS AND GEM SEEMED TO PUSH PRECIP FARTHER SOUTH. AS A RESULT...HAVE CONTINUED WITH EARLIER CONSENSUS RUNS AND INCREASED POPS AND QPF ACROSS THE CWA. LATEST MODEL RUNS ALSO SHOW COLDER 850 TEMPERATURE TRENDS...WHILE SURFACE TEMPS WILL REMAIN RIGHT AT FREEZING...SO EXPECT SNOW TO BE THE MAIN PRECIP TYPE. WILL CONTINUE TO MONITOR LATEST MODEL RUNS FOR ANY CHANGE IN PLACEMENTS/WIND DIRECTIONS AND RESULTING PRECIP TYPES/LOCATIONS. MIDLEVEL DRY AIR AHEAD OF APPROACHING RIDGE WILL THEN CUT IN BY THURSDAY NIGHT AS SHORTWAVE MOVES OFF TO THE NORTHEAST...REDUCING PRECIP CHANCES FROM WEST TO EAST OVERNIGHT. THE RESULT OF THIS UPPER LEVEL RIDGING WILL BE TO TURN WINDS MORE NORTHWESTERLY BY FRIDAY INTO SATURDAY...ALLOWING ARCTIC AIR TO PENETRATE SOUTHWARD ACROSS THE GREAT LAKES. 13/12Z GFS HAS H850 TEMPS DROPPING TO -17C SATURDAY. THIS...ALONG WITH LINGERING LOW LEVEL MOISTURE...WILL CREATE THE CONVERGENCE NEEDED FOR LAKE EFFECT SNOW FRIDAY THROUGH SATURDAY IN AREAS ALONG LAKE SUPERIOR FAVORED BY NW WINDS. 13/12Z ECMWF ALSO KEEPS WITH THIS TREND...THOUGH FALLING TEMPERATURES AND AMOUNT OF CONVERGENCE ARE SLIGHTLY LESS MAGNIFIED. AS A RESULT...HAVE INCREASED SLIGHT CHANCE TO CHANCE POPS ALONG LAKE SUPERIOR IN AREAS FAVORED BY A NW WIND DIRECTION...KEEPING WITH PREVIOUS FORECASTS. ANY LINGERING LES EAST WILL COME TO AN END LATE SATURDAY...AS WINDS BECOME MORE SOUTHWESTERLY...AHEAD OF THE NEXT SFC LOW/500MB TROUGH APPROACHING FROM CENTRAL CANADA AND MN. THERE ARE SIGNIFICANT ENOUGH TIMING DIFFERENCE TO RESULT IN MODERATE CONFIDENCE IN THE FCST BEYOND THIS PERIOD. WHILE THE GFS AND ECMWF ARE IN FAIRLY GOOD SHAPE UP UNTIL THIS POINT...THE 13/06Z RUN OF THE GFS BECOMES ROUGHLY 12 HRS SLOWER THAN THE MORE CONSISTENT ECMWF WITH THE HANDLING OF THIS WAVE /CENTERED ACROSS THE UPPER GREAT LAKES AT 00Z MONDAY...WHILE THE ECMWF HAS IT OVER THE LOWER GREAT LAKES/. WHILE THE ECMWF INDICATES A DRY FRONTAL PASSAGE WITH THE SFC LOW CENTERED OVER NORTHERN ONTARIO. GIVEN THE SLOWER AND MORE SOUTHERN GFS...A BROAD SFC LOW WILL LIKELY DEVELOP OVER THE GREAT LAKES...WITH LIGHT PRECIP AND PLENTY OF CLOUD COVER BEFORE THE SYSTEM EJECTS EASTWARD MONDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 546 PM EST MON FEB 13 2012 A DISTURBANCE MOVING FROM THE CNTRL PLAINS TO THE LOWER GREAT LKS WILL HAVE THE LOWER TO MID CLOUDS TO LOWER THROUGH THE NIGHT AND LIKELY BE IN THE MVFR CAT AFTER 06Z. MODELS WERE HINTING AT PLENTY OF LLVL MOISTENING...WHICH COULD LEAD TO SOME REDUCED VSBYS FROM BR. WITH LIMITED LLVL LIFT AND SINCE WINDS WILL BE OUT OF AN UNFAVORABLE SWRLY DIRECTION...WILL KEEP VSBY REDUCTION OUT AT THIS TIME. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 400 PM EST MON FEB 13 2012 A HIGH PRESSURE RIDGE BUILDING OVER THE AREA WILL KEEP WINDS BELOW 20KTS TONIGHT THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS ON WED NIGHT WILL MOVE THROUGH THE GREAT LAKES REGION FROM THURSDAY INTO FRIDAY. THIS WILL LEAD TO NW WINDS UP TO 25KTS OVER ERN LK SUPERIOR. HIGH PRESSURE WILL THEN MOVE OVER THE AREA FOR THE FIRST PART OF THE WEEKEND AND KEEP WINDS BELOW 20KTS. WITH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...LITTLE TO NO FREEZING SPRAY IS EXPECTED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...07 SHORT TERM...JLB LONG TERM...JMW AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1123 PM CST MON FEB 13 2012 .UPDATE... ISSUED AT 910 PM CST MON FEB 13 2012 REVIEW OF 00Z NAM AND RUC DATA AS WELL AS OBSERVED DATA SHOWS DRIZZLE THREAT TO BE WITH US FOR A WHILE WITH MUCH OF THE MID AND HI LEVEL CLOUDS NOW STRIPPED AWAY LEAVING BEHIND EXPANSIVE LO CLOUD DECK. STILL NEED WEAK LIFT...WHICH WILL BE PROVIDED BY EITHER WEAK CYCLONIC FLOW OR TROF THAT WILL MOVE THRU LATE TONIGHT AND EARLY TUESDAY MORNING. TEMPS CURRENTLY AT OR BELOW FREEZING AT ALL LOCATIONS...AND DESPITE S SFC WNDS...ADVECTION THAT RESULTS IS NEUTRAL...SO WE SHOULD SEE NEAR STEADY TEMPS OVERNIGHT...TO KEEP THE DRIZZLE FREEZING ON EXPOSED AND/OR UNTREATED SURFACES. EXTENDED THE WSW WHICH WAS ALREADY IN EFFECT UNTIL MIDNIGHT... UNTIL 6AM. MAY NEED TO BE EXTENDED FURTHER BEYOND 12Z TUESDAY FOR PARTS OF THE ERN FA IF TROF IS SLOWER THAN ANTICIPATED. TES && .SHORT TERM... ISSUED AT 300 PM CST MON FEB 13 2012 (TONIGHT) FOCUS TONIGHT WILL BE THE ONGOING PRECIP ACROSS THE REGION. UPPER TROF CURRENTLY OVER NEB/KS REGION WILL MOVE THRU THE CWA TONIGHT BRINGING THE SN TO AN END. AS OF 19Z...FIRST BAND OF HEAVY PRECIP IS MOVING OUT OF CNTL MO AND INTO THE ERN PORTIONS OF MO AND IL. THIS IS EXPECTED TO BE THE BULK OF THE SN FOR THE NWRN THIRD OF THE CWA. MDLS STILL INDICATE ANOTHER S/W LIFTING NEWD LATE THIS AFTERNOON AND EARLY EVE RESULTING IN ANOTHER BAND OF HEAVIER SN FOR AREAS ROUGHLY ALONG AND E OF A LINE FROM VIH/STL/3LF. ONCE THE SN COMES TO AN END...STILL EXPECT PATCHY FZDZ TO LINGER FOR A COUPLE OF HRS AS THE DEEP CLOUD LAYER IS LOST. A LOT OF UNCERTAINTY REGARDING HOW LONG THE FZDZ WILL CONTINUE OVERNIGHT. HAVE KEPT MENTION OF FZDZ OVERNIGHT FOR NOW WITH UPDATES AS NEEDED. AS FOR TEMPS OVERNIGHT...HAVE A QUICK DROP IN TEMPS SHORTLY AFTER SUNSET. HOWEVER...EXPECT TEMPS TO REMAIN NEARLY STEADY OVERNIGHT GIVEN SLY FLOW AND AMPLE CLOUD COVER. TILLY && .LONG TERM... ISSUED AT 300 PM CST MON FEB 13 2012 (TUESDAY THROUGH MONDAY) IN THE WAKE OF TONIGHTS STORM SYSTEM...HEIGHTS WILL RISE ALOFT ON TUESDAY AND LOW LEVEL WAA WILL GET UNDERWAY IN ERNEST AS THE LOW LEVEL RIDGE PASSES TO THE EAST. NORMALLY THIS WOULD ALLOW FOR A SIGNIFICANT WARM-UP AS H85 TEMPS RISE ON THE ORDER OF +6 TO +8 DEGC. HOWEVER SIGNIFICANT LOW CLOUDS ARE EXPECTED TO BLANKET THE AREA AT THE START OF THE DAY AND THESE WILL GRADUALLY CLEAR WEST TO EAST. THIS TREND COMBINED WITH LIGHT SNOW COVER SHOULD KEEP TEMPS IN CHECK AND HAVE FAVORED HIGHS CLOSER TO THE COOLER MET GUIDANCE. THE NEXT BIG SYSTEM TO IMPACT THE AREA IS ON TRACK FOR WED/WED NIGHT AND IS CURRENTLY CENTERED IN CALIFORNIA. THE GUIDANCE IS IN GOOD AGREEMENT THAT THE UPPER TROF MOVING THROUGH THE GULF OF AK WILL BE THE KICKER AS IT DIGS SSEWD ALONG THE WEST COAST OVER THE NEXT 48H...EJECTING THE CALIFORNIA TROF THROUGH THE SOUTHERN ROCKIES AND INTO THE PLAINS ON WEDNESDAY AND THROUGH THE MID MS VALLEY ON WED NIGHT. THIS UPPER SYSTEM SHOULD WEAKEN AS IT MOVES THROUGH OUR AREA AS IT ENCOUNTERS INCREASINGLY CONFLUENT FLOW ALOFT. AFTER LOSING THE LOW CLOUDS ON TUESDAY...MID/HI CLOUDS WILL BEGIN TO SPREAD BACK INTO THE AREA ON TUESDAY NIGHT IN ADVANCE OF THE MIGRATING UPPER TROF. PRECIPITATION SHOULD BEGIN TO EVOLVE LATE TUESDAY NIGHT ACROSS THE PLAINS IN RESPONSE TO STRENGTHENING LOW LEVEL WAA AND MOISTURE TRANSPORT. AT THIS TIME I AM THINKING IT WILL HOLD OFF IN OUR CWA UNTIL AFTER 14-15Z...AT LEAST HOPING SO. IF IT STARTS EARLIER THERE COULD BE SOME AREAS WITH SUB-FREEZING SURFACE TEMPERATURES TO CONTEND WITH. BY AFTERNOON ON WEDNESDAY...THE COVERAGE OF RAIN SHOULD INCREASE DRAMATICALLY IN RESPONSE TO STRONG LOW LEVEL WAA AND CONTINUE MOISTURE TRANSPORT INTO THE AREA VIA A SSWLY LLJ...AND INCREASING LARGE SCALE ASCENT ASSOCIATED WITH THE UPPER TROF. SOUNDINGS AND MODEL DELTA THETAE PROGS SHOW THE DEVELOPMENT OF ELEVATED INSTABILITY AS MID LEVEL LAPSE RATES AOA 7 DEGC/KM SPREAD INTO THE AREA IN ADVANCE OF THE TROF AND OVERSPREAD THE WARMING/MOISTENING LOW LEVELS. THEREFORE I HAVE ADDED A CHANCE OF THUNDER FROM THE AFTERNOON INTO THE EVENING HOURS. THE RAIN SHOULD TAPER AFTER MIDNIGHT AS THE WARM CONVEYOR BELT MOVES EASTWARD IN ASSOCIATION WITH THE ADVANCING UPPER TROF. THE SPEED OF THIS SYSTEM VARIES IN SOME IN THE GUIDANCE...BUT ALL SUGGEST THE PRECIPITATION WILL BE OVER BY THE TIME ANY DEEPER COLD AIR ARRIVES IN ITS WAKE THAT WOULD SUPPORT SNOWFALL. THE WHOLE UPPER PATTERN IS SOMEWHAT PROGRESSIVE THURSDAY AND BEYOND. THE MODELS SHOW A SPLIT REGIME ON FRIDAY WITH A SOUTHERN STREAM UPPER LOW IN WEST TX AND DEEPER NORTHERN STREAM TROF FROM HUDSON BAY INTO THE GREAT LAKES. AFTER FRIDAY THE DETERMINISTIC MODELS AND ENSEMBLES/MEMBERS QUICKLY DIVERGE AND SHOW MUCH SPREAD SATURDAY THROUGH MONDAY. THIS LEADS LOW CONFIDENCE IN DETAILS...HOWEVER THE GENERAL TRENDS SHOW NO SIGNFICANT WEATHER SYSTEMS IN THIS TIME FRAME AND TEMPERATURES AT OR ABOVE AVERAGE. GLASS && .AVIATION... ISSUED AT 1113 PM CST MON FEB 13 2012 IFR FLIGHT CONDITIONS IN OCCASIONAL LIGHT FREEZING DRIZZLE...FOG...AND LOW STRATUS WILL PREVAIL FOR THE REST OF THE NIGHT. ADDITIONALLY...THE UPPER LEVEL ENERGY ASSOCIATED WITH THIS STORM SYSTEM WILL RIPPLE ACROSS THE AREA THROUGH 12Z PRODUCING A BRIEF BURST OF SNOW WHICH WILL REDUCE THE VISIBILITY TO AROUND 1SM AS IT PASSES. CONDITIONS WILL IMPROVE GRADUALLY AFTER SUNRISE...THOUGH IT WILL TAKE MOST OF THE MORNING BEFORE CIGS RISE ABOVE 900FT AGL. SLOW IMPROVEMENT WILL CONTINUE IN THE AFTERNOON...AND EVENTUALLY CLOUDS SHOULD CLEAR OUT BEFORE SUNSET. SPECIFICS FOR KSTL... IFR FLIGHT CONDITIONS WILL CONTINUE TO PREVAIL AT LAMBERT AT LEAST THROUGH MID MORNING. WILL CONTINUE TO SEE OCCASIONAL LIGHT FREEZING DRIZZLE AT THE TERMINAL UNTIL AROUND 12Z...AND THERE WILL BE A BRIEF BURST OF SNOW BETWEEN 07Z-09Z WHICH WILL BRING THE VISIBILITY DOWN TO AROUND 1SM AS THE UPPER LEVEL ENERGY ASSOCIATED WITH THIS STORM RIPPLES BY. SHOULD SEE SLOW IMPROVEMENT AFTER SUNRISE WITH CIGS RISING ABOVE 900FT AGL BY NOON AND SCATTERING BEFORE 00Z. CARNEY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR AUDRAIN MO- BOONE MO-CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO- GASCONADE MO-IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO- OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. IL...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR ADAMS IL-BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL- JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL- MONTGOMERY IL-PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORMAN OK
1140 PM CST MON FEB 13 2012 .AVIATION... DEVELOPMENT OF FOG AND LOW STRATUS IS WELL UNDERWAY ACROSS MUCH OF OKLAHOMA AND PARTS OF WESTERN NORTH TEXAS. WHILE CIGS CONTINUED TO ERODE ACROSS THE NORTHERN HALF OF OKLAHOMA...LIGHT SOUTHEAST WINDS CAUSED LOW CIGS TO BUILD BACK INTO SOME AREAS. IFR/LIFR CONDITIONS CAN BE EXPECTED AT MOST TERMINALS...WITH SOME VSBYS AS LOW AS 1/4 MILE ALREADY BEING REPORTED ACROSS CENTRAL/SOUTHERN OKLAHOMA. EXPECT TREND TO CONTINUE WITH DENSE FOG BUILDING INTO MUCH OF OKLAHOMA AND WESTERN NORTH TEXAS. WITH SLIGHTLY DRIER AIR AND WEST TO NORTHWEST WINDS ACROSS NORTHWEST OKLAHOMA...KWWR AND KGAG WILL LIKELY REMAIN VFR OVERNIGHT...THOUGH SOME PATCHY FOG CANNOT BE COMPLETELY RULED OUT TOWARD SUNRISE. CONDITIONS WILL IMPROVE LATE TUESDAY MORNING AS TEMPERATURES WARM AND WINDS SHIFT TO SOUTHERLY AHEAD OF AN APPROACHING STORM SYSTEM. && .PREV DISCUSSION... /ISSUED 946 PM CST MON FEB 13 2012/ UPDATE... WITH LIGHT AND VARIABLE WINDS... MOSTLY CLEAR SKIES THIS EVENING... AND MOIST AIR AT THE SURFACE... FOG IS EXPECTED TO CONTINUE TO DEVELOP OVERNIGHT ACROSS PORTIONS OF THE FA... WITH THE LEAST LIKELY AREA BEING NORTHWEST OK. DEWPOINT DEPRESSIONS ARE ALREADY ZERO OR ONE IN MANY LOCATIONS. WITH THE LOW DEWPOINT DEPRESSIONS AND VISIBILITIES ALREADY LESS THAN A MILE IN SOME LOCATIONS WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR PARTS OF THE FA THROUGH 10 AM TUESDAY. THE ADVISORY MAY NEED TO BE EXTENDED FURTHER WEST AND/OR NORTH LATER TONIGHT BUT FOR NOW OUTLINED THE MOST LIKELY AREA. SOME LOCATIONS MAY ALSO DROP BELOW FREEZING WHICH COULD CAUSE SOME FREEZING FOG LEAVING A GLAZE OF ICE ON OBJECTS. OTHERWISE...MADE SOME ADJUSTMENTS TO HOURLY GRIDS AND LOW TEMPERATURES. THE FREEZING TEMPS MAY ALSO CAUSE SOME OF THE WET ROADS TO ICE OVER AGAIN TONIGHT LEADING TO SLIPPERY ROADWAYS. WILL SEND UPDATED PRODUCTS SHORTLY. MAXWELL PREV DISCUSSION... /ISSUED 549 PM CST MON FEB 13 2012/ AVIATION... UPPER LEVEL SYSTEM THAT BROUGHT WINTRY WEATHER TO ALL TERMINALS YESTERDAY HAS EXITED TO THE EAST. OVERNIGHT FORECAST IS SOMEWHAT COMPLEX DUE TO ONGOING LOW CIGS OVER EASTERN OKLAHOMA AND RESIDUAL SNOW PACK ACROSS MUCH OF CENTRAL AND SOUTHWEST OKLAHOMA. AS WINDS DECREASE THROUGH 03Z...EXPECT COMBINATION OF SURFACE MOISTURE AND COOLING TO ALLOW FOR WIDESPREAD FOG DEVELOPMENT. VEERING SURFACE WINDS ACROSS WESTERN OKLAHOMA MAY INITIALLY LIMIT LOW STRATUS FORMATION...BUT EXPECT LOW CIGS TO BUILD BACK IN LATE TONIGHT. MOST TAF SITES WILL SEE MVFR/IFR AND POSSIBLY LIFR VSBYS/CIGS THROUGH TUESDAY MORNING...EXCEPT KGAG AND KWWR...WHERE SOME LOW LEVEL DRYING HAS OCCURRED. PREV DISCUSSION... /ISSUED 307 PM CST MON FEB 13 2012/ DISCUSSION... ALTHOUGH STILL SOMEWHAT GUSTY THIS AFTERNOON... WINDS WILL BECOME LIGHT OVERNIGHT. BUT WITH THESE LIGHTER WINDS... THE REDEVELOPMENT OF A MOIST BOUNDARY LAYER /AND FRESH SNOW IN SOME LOCATIONS/ WILL LIKELY LEAD TO FOG DEVELOPMENT OVERNIGHT. THE RUC... HRRR AND NAM ARE VERY AGGRESSIVE WITH FOG DEVELOPMENT OVERNIGHT AND A FOG ADVISORY OR EVEN A FREEZING FOG ADVISORY MAY BE NEEDED TONIGHT/TUESDAY MORNING BUT WILL NOT ISSUE WITH THIS PACKAGE YET. WARMING TEMPERATURES ARE EXPECTED OVER THE NEXT COUPLE OF DAYS. NEXT STORM SYSTEM WILL MOVE THROUGH THE PLAINS ON WEDNESDAY WITH PRECIP MOVING EAST FOLLOWED BY GUSTY SOUTHWEST WINDS BEHIND A DRYLINE. LATER IN THE FORECAST... HAVE ADDED LOW POPS FRIDAY NIGHT WITH SOME QPF SIGNAL FROM BOTH GFS AND ECMWF... BUT OTHERWISE NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE EXTENDED PERIODS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 29 58 41 60 / 0 0 20 50 HOBART OK 28 54 39 61 / 0 0 10 20 WICHITA FALLS TX 34 65 46 69 / 0 0 30 40 GAGE OK 19 57 34 57 / 0 0 10 10 PONCA CITY OK 22 50 40 58 / 0 0 20 60 DURANT OK 35 57 50 70 / 0 0 30 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR OKZ018>020- 023>032-037>048-050>052. TX...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR TXZ086-089-090. && $$ 25/84
AREA FORECAST DISCUSSION...CORRECTED WED AFTERNOON THROUGH THURSDAY
NWS LA CROSSE WI
353 AM CST TUE FEB 14 2012 .SHORT TERM...TODAY THROUGH THURSDAY 353 AM CST TUE FEB 14 2012 AT 3 AM...KARX RADAR SHOWED A DEFORMATION BAND OF LIGHT SNOW MOVING EAST ACROSS THE FORECAST AREA. THE WESTERN EDGE WAS LOCATED FROM MONDOVI WISCONSIN TO CHARLES CITY IOWA. THE LATEST RUC SHOWS THAT THE 800-700 MB FRONTOGENESIS ASSOCIATED WITH THIS BAND WILL CONTINUE TO MOVE EAST THIS MORNING AND GRADUALLY WEAKEN. AT THE SAME TIME...THE SOUNDINGS SHOW THAT THE MOISTURE BELOW 850 MB WILL GRADUALLY DRY. EVEN THOUGH IT IS DRYING OUT...THERE CONTINUES TO BE SOME ICE CRYSTALS SEEDING FROM ALOFT TO KEEP THE PRECIPITATION IN THE FORM OF SNOW. DUE TO THIS JUST WENT WITH SOME FLURRIES THIS MORNING. FOR TONIGHT...THE 14.00Z MODELS SUGGEST THAT A PV ANOMALY WILL MOVE EAST THROUGH CENTRAL MINNESOTA AND NORTHERN WISCONSIN. MODEL SOUNDINGS SHOW SOME MOISTURE BETWEEN 925 AND 700 MB. IN THIS SAME LAYER...THERE IS ENOUGH LIFT FOR A BRIEF PERIOD OF LIGHT SNOW ACROSS NORTH CENTRAL WISCONSIN. THE NAM/WRF...GFS...AND GEM GENERATE SOME LIGHT PRECIPITATION ACROSS THIS AREA. DUE TO THIS...ADDED A SLIGHT CHANCE TO THE FORECAST FOR TONIGHT. FROM WEDNESDAY AFTERNOON THROUGH THURSDAY...THE 14.00Z GFS...ECMWF... AND NAM/WRF ARE IN GOOD AGREEMENT THAT A SURFACE LOW WILL TRACK FROM SOUTHWEST MISSOURI NORTHEAST TO SOUTHERN ONTARIO. THIS TRACK IS VERY SIMILAR TO THE 13.12Z MODELS. THE ONE EXCEPTION TO THIS WAS THE GEM WHICH SHOWS THE LOW MOVING FROM KANSAS CITY NORTHEAST TO CHICAGO ILLINOIS. LOOKING AT ITS ENSEMBLE FAMILY...ONLY 3 OF ITS 16 MEMBERS SUPPORT THIS MORE NORTHERN TRACK...AND IN MANY CASES THERE IS NO PRECIPITATION AT ALL IN OUR FORECAST AREA. THE REASON FOR THE MORE SOUTHERN TRACK THAN THE 13.00Z IS HOW THE NORTHERN STREAM SYSTEM MOVING THROUGH SOUTHERN CANADA INTERACTS WITH THE SOUTHERN STREAM SYSTEM MOVING THROUGH THE CENTRAL PLAINS AND MID MISSISSIPPI RIVER VALLEY. THE NORTHERN STREAM IS SYSTEM LESS AMPLIFIED IN ITS LATEST RUNS /WITH THE EXCEPTION OF THE GEM/...AND THIS RESULT IN THE SOUTHERN LOW NOT BEING DRAWN NORTHWARD INTO OUR AREA. DUE TO THIS...TRENDED BOTH WEDNESDAY AFTERNOON AND THURSDAY DRIER. IF THIS TREND CONTINUES...WILL LIKELY HAVE TO GO DRY FOR BOTH OF THESE PERIOD. FOR WEDNESDAY NIGHT...THE PRECIPITATION CHANCES WERE TRENDED FURTHER SOUTHEAST. AT THIS TIME...IT LOOKS LIKE THE ONLY MEASURABLE SNOW WILL BE ACROSS SOUTHWEST WISCONSIN. .LONG TERM...THURSDAY NIGHT THROUGH WASHINGTONS BIRTHDAY 342 AM CST TUE FEB 14 2012 ON WASHINGTONS BIRTHDAY...THE 14.00Z CONTINUES TO SHOW THAT CYCLOGENESIS WILL DEVELOP ACROSS THE DAKOTAS AND THEN MOVE EAST THROUGH THE FORECAST AREA. LIKE THE PAST COUPLE OF DAYS...THE PRECIPITATION TYPE FORECAST IS GREATLY COMPLICATED BY DIFFERENCES IN THE BOUNDARY LAYER TEMPERATURES. FOR THE TIME BEING...JUST WENT WITH A MENTION OF RAIN AND SNOW WITH THIS SYSTEM. && .AVIATION... 1105 PM CST MON FEB 13 2012 IFR/MVFR CIGS WILL CONTINUE THROUGH THE EARLY MORNING...LOOKING FOR IMPROVEMENT FROM WEST TO EAST IN THE AFTERNOON. HOW QUICKLY THE CIGS RISE IS IN QUESTION THOUGH...WITH DIFFERING OPINIONS IN THE MODELS. CONFIDENCE NOT HIGH...BUT FAIRLY SURE THEY SHOULD HANG THROUGH 18Z...AND WILL TREND CIGS THIS WAY. -SN LOOKS LIKE THE MAIN THREAT OVERNIGHT...AND WILL REDUCE VSBYS TO 2-3 SM AT TIMES. DON/T EXPECT MUCH MORE ACCUMULATION...PERHAPS A COUPLE TENTHS OF AN INCH. ONE POTENTIAL TROUBLE SPOT IS THE POSSIBILITY OF SUB 1SM FG VSBYS AT KRST AFTER 12Z OR SO. SFC OBS AND SATELLITE TRENDS POINT TO LOW CIGS AND QUITE A FEW 1/4SM LOCATIONS ON THE FAR WESTERN EDGE OF THE CLOUDS SHIELD. THIS COULD TRACK ACROSS KRST...BUT SHOULD MODERATE ENOUGH THAT ANY IMPACT ON KLSE WOULD BE MINIMAL. AGAIN...UNCERTAIN WITH JUST HOW LOW CIGS/VSBYS WILL BE BY THE TIME THIS REGION GETS TO KRST. WILL OPT TO KEEP A PERIOD OF 1SM BR FOR KRST FOR NOW. && .ARX WATCHES/WARNINGS/ADVISORIES... 342 AM CST TUE FEB 14 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
342 AM CST TUE FEB 14 2012 .SHORT TERM...TODAY THROUGH THURSDAY 342 AM CST TUE FEB 14 2012 AT 3 AM...KARX RADAR SHOWED A DEFORMATION BAND OF LIGHT SNOW MOVING EAST ACROSS THE FORECAST AREA. THE WESTERN EDGE WAS LOCATED FROM MONDOVI WISCONSIN TO CHARLES CITY IOWA. THE LATEST RUC SHOWS THAT THE 800-700 MB FRONTOGENESIS ASSOCIATED WITH THIS BAND WILL CONTINUE TO MOVE EAST THIS MORNING AND GRADUALLY WEAKEN. AT THE SAME TIME...THE SOUNDINGS SHOW THAT THE MOISTURE BELOW 850 MB WILL GRADUALLY DRY. EVEN THOUGH IT IS DRYING OUT...THERE CONTINUES TO BE SOME ICE CRYSTALS SEEDING FROM ALOFT TO KEEP THE PRECIPITATION IN THE FORM OF SNOW. DUE TO THIS JUST WENT WITH SOME FLURRIES THIS MORNING. FOR TONIGHT...THE 14.00Z MODELS SUGGEST THAT A PV ANOMALY WILL MOVE EAST THROUGH CENTRAL MINNESOTA AND NORTHERN WISCONSIN. MODEL SOUNDINGS SHOW SOME MOISTURE BETWEEN 925 AND 700 MB. IN THIS SAME LAYER...THERE IS ENOUGH LIFT FOR A BRIEF PERIOD OF LIGHT SNOW ACROSS NORTH CENTRAL WISCONSIN. THE NAM/WRF...GFS...AND GEM GENERATE SOME LIGHT PRECIPITATION ACROSS THIS AREA. DUE TO THIS...ADDED A SLIGHT CHANCE TO THE FORECAST FOR TONIGHT. FROM WEDNESDAY AFTERNOON THROUGH THURSDAY...THE 14.00Z GFS...ECMWF... AND NAM/WRF ARE IN GOOD AGREEMENT THAT A SURFACE LOW WILL TRACK FROM SOUTHWEST MISSOURI NORTHEAST TO SOUTHERN ONTARIO. THIS TRACK IS VERY SIMILAR TO THE 13.12Z MODELS. THE ONE EXCEPTION TO THIS WAS THE GEM WHICH SHOWS THE LOW MOVING FROM KANSAS CITY NORTHEAST TO CHICAGO ILLINOIS. LOOKING AT ITS ENSEMBLE FAMILY...ONLY 3 OF ITS 16 MEMBERS SUPPORT THIS MORE NORTHERN TRACK...AND IN MANY CASES THERE IS NO PRECIPITATION AT ALL IN OUR FORECAST AREA. THE REASON FOR THE MORE SOUTHERN TRACK THAN THE 13.00Z IS HOW THE NORTHERN STREAM SYSTEM MOVING THROUGH SOUTHERN CANADA INTERACTS WITH THE SOUTHERN STREAM MOVING THROUGH THE CENTRAL PLAINS AND MID MISSISSIPPI RIVER VALLEY. THE NORTHERN STREAM SYSTEM IS MOVING A BIT FASTER EAST THAT ITS SOUTHERN COUNTERPART. AS A RESULT...IT IS NOT DRAWN NORTHWARD INTO OUR AREA. DUE TO THIS...TRENDED BOTH WEDNESDAY AFTERNOON AND THURSDAY DRIER. IF THIS TREND CONTINUES...WILL LIKELY HAVE TO GO DRY FOR BOTH OF THESE PERIOD. FOR WEDNESDAY NIGHT...THE PRECIPITATION CHANCES WERE TRENDED FURTHER SOUTHEAST. AT THIS TIME...IT LOOKS LIKE THE ONLY MEASURABLE SNOW WILL BE ACROSS SOUTHWEST WISCONSIN. .LONG TERM...THURSDAY NIGHT THROUGH WASHINGTONS BIRTHDAY 342 AM CST TUE FEB 14 2012 ON WASHINGTONS BIRTHDAY...THE 14.00Z CONTINUES TO SHOW THAT CYCLOGENESIS WILL DEVELOP ACROSS THE DAKOTAS AND THEN MOVE EAST THROUGH THE FORECAST AREA. LIKE THE PAST COUPLE OF DAYS...THE PRECIPITATION TYPE FORECAST IS GREATLY COMPLICATED BY DIFFERENCES IN THE BOUNDARY LAYER TEMPERATURES. FOR THE TIME BEING...JUST WENT WITH A MENTION OF RAIN AND SNOW WITH THIS SYSTEM. && .AVIATION... 1105 PM CST MON FEB 13 2012 IFR/MVFR CIGS WILL CONTINUE THROUGH THE EARLY MORNING...LOOKING FOR IMPROVEMENT FROM WEST TO EAST IN THE AFTERNOON. HOW QUICKLY THE CIGS RISE IS IN QUESTION THOUGH...WITH DIFFERING OPINIONS IN THE MODELS. CONFIDENCE NOT HIGH...BUT FAIRLY SURE THEY SHOULD HANG THROUGH 18Z...AND WILL TREND CIGS THIS WAY. -SN LOOKS LIKE THE MAIN THREAT OVERNIGHT...AND WILL REDUCE VSBYS TO 2-3 SM AT TIMES. DON/T EXPECT MUCH MORE ACCUMULATION...PERHAPS A COUPLE TENTHS OF AN INCH. ONE POTENTIAL TROUBLE SPOT IS THE POSSIBILITY OF SUB 1SM FG VSBYS AT KRST AFTER 12Z OR SO. SFC OBS AND SATELLITE TRENDS POINT TO LOW CIGS AND QUITE A FEW 1/4SM LOCATIONS ON THE FAR WESTERN EDGE OF THE CLOUDS SHIELD. THIS COULD TRACK ACROSS KRST...BUT SHOULD MODERATE ENOUGH THAT ANY IMPACT ON KLSE WOULD BE MINIMAL. AGAIN...UNCERTAIN WITH JUST HOW LOW CIGS/VSBYS WILL BE BY THE TIME THIS REGION GETS TO KRST. WILL OPT TO KEEP A PERIOD OF 1SM BR FOR KRST FOR NOW. && .ARX WATCHES/WARNINGS/ADVISORIES... 342 AM CST TUE FEB 14 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
637 AM EST TUE FEB 14 2012 ...PATCHES OF LIGHT SLEET FALLING INLAND THIS MORNING... .SYNOPSIS... A WEAK WAVE OF LOW PRESSURE WILL MOVE ACROSS THE GULF COAST TODAY. A COLD FRONT WILL PUSH OFFSHORE TONIGHT. ANOTHER COLD FRONT WILL MOVE ACROSS THE EAST COAST THURSDAY AND LINGER TO THE SOUTH THROUGH THE WEEKEND. A LOW PRESSURE SYSTEM COULD DEVELOP ACROSS THE GULF OF MEXICO AND IMPACT THE FORECAST AREA EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... STARTING TO RECEIVE SOME REPORTS OF LIGHT SLEET ACROSS INTERIOR SOUTHEAST GEORGIA AND THE CSRA. RUC SOUNDINGS STILL SUPPORT OCCASIONAL PHASE CHANGES TO SLEET WHERE POCKETS OF HEAVIER SHOWERS ARE ABLE TO MAXIMIZE DIABATIC EFFECTS. REFLECTIVITY RETURNS OF 40+ DBZ APPEARS TO BE THE THRESHOLD FOR SLEET ON THE KCLX RADAR. THE GREATEST RISK FOR SLEET WILL CONTINUE TO BE CENTERED ACROSS INTERIOR SOUTHEAST GEORGIA...BUT WOULD NOT BE SURPRISED TO SEE A FEW SLEET PELLETS MIX IN AS FAR EAST AS WALTERBORO...BEAUFORT AND SAVANNAH. NO IMPACTS ARE EXPECTED. OTHERWISE...ITS LOOKING LESS AND LESS LIKELY THAT MEASURABLE RAINS WILL FALL IN THE CHARLESTON TRI-COUNTY AREA. OPTED NOT TO MODIFY POPS JUST YET...BUT CURRENT TRENDS ARE CONCERNING. REGIONAL RADARS CERTAINLY LOOK WORSE THAN WHAT IS OCCURRING AT THE SURFACE. A BROAD WARM AIR ADVECTION REGIME IS TAKING SHAPE ACROSS THE SOUTHEAST U.S. THIS MORNING AS WEAK LOW PRESSURE MEANDERS EAST ALONG THE NORTHERN GULF COAST. INFRARED SATELLITE IMAGERY SHOWS CLOUD TOPS SLOWLY COOLING ACROSS CENTRAL GEORGIA AS SHORTWAVE ENERGY APPROACHES THE SOUTHERN APPALACHIANS. RAIN CHANCES WILL STEADILY INCREASE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA AFTER SUNRISE AS THE CORE OF THE STRONGEST WARM AIR ADVECTION TRAVERSES FROM WEST-EAST THIS MORNING. MODELS ARE IN FAIR AGREEMENT IN THE PLACEMENT OF THE HIGHEST POPS TODAY WITH MOST MEMBERS CLUSTERING THE HIGHEST PROBABILITIES ROUGHLY ALONG THE SAVANNAH RIVER FROM MID-LATE MORNING INTO THE EARLY AFTERNOON HOURS. RAINFALL WILL GENERALLY BE LIGHT TODAY WITH FORECAST SOUNDINGS DEPICTING A RATHER PARCHED SUB-CLOUD LAYER HOLDING FOR MUCH OF THE DAY. THIS WILL LIMIT POTENTIAL RAINFALL AMOUNTS TO ROUGHLY 1/10TH INCH OR LESS FOR MANY LOCATIONS AND THERE ARE EVEN SOME INDICATIONS IN THE HIGHER RESOLUTION DATA SETS THAT MUCH OF THE CHARLESTON TRI-COUNTY COULD RECEIVE LITTLE IF ANY RAINFALL FROM THIS EVENT. THIS IS UNFORTUNATE GIVEN THE EXPANDING EXCEPTIONAL DROUGHT CONDITIONS. PLAN TO LIMIT POPS TO 40-60 PERCENT TODAY WITH THE HIGHEST GRIDDED POPS CONFINED IN A RATHER BROAD CORRIDOR FROM MILLEN AND METTER EAST TO BEAUFORT...SAVANNAH AND HINESVILLE. THE LOWEST POPS /40-50 PERCENT/ WILL BE PLACED ACROSS THE CHARLESTON TRI-COUNTY AREA. SOME ADJUSTMENTS WILL MOST CERTAINLY BE NEEDED AS THE DAY PROGRESSES. TEMPERATURES ACROSS THE REGION EARLY THIS MORNING HAVE DROPPED INTO THE MID-UPPER 30S WITH A FEW LOWER NOTED IN A FEW OF THE NORMALLY COLDER LOCATIONS. TEMPERATURES WILL LIKELY FLUCTUATE SOME OVER THE NEXT SEVERAL HOURS AS CLOUD LAYERS THICKEN/LOWER AND LIGHT PRECIPITATION BEGINS TO INITIATE DIABATIC COOLING. FORECAST SOUNDINGS ACROSS THE FAR WESTERN ZONES STILL SUGGEST THERE WILL BE ABOUT A 3-4 HOUR WINDOW FOR SOME LIGHT SLEET TO MIX IN WITH THE RAIN AT TIMES. HAVE ALREADY SEEN SEVERAL REPORTS OF LIGHT SLEET ACROSS CENTRAL GEORGIA OVER THE PAST FEW HOURS WITH THE MOST RECENT REPORT COMING OUT OF THE WARNER ROBBINS AREA. DUAL-POL DATA FROM THE RECENTLY UPGRADED KFFC RADAR HAS BEEN MOST USEFUL IN HELPING TO VERIFY P-TYPE TRENDS EARLY THIS MORNING WITH SLEET REPORTS LINING UP NICELY WITH THE HYBRID HYDROMETER CLASSIFICATION PRODUCT. WILL CONTINUE TO HIGHLIGHT A CHANCE OF SLEET ROUGHLY ALONG AND WEST OF A HAMPTON-SPRINGFIELD-CLAXTON-REIDSVILLE LINE THROUGH MID-MORNING. VERY LITTLE OR NO ACCUMULATION OF SLEET IS EXPECTED GIVEN THE EXPECTED VERY LIGHT PRECIPITATION RATES...HOWEVER WE MAY CONSIDER ISSUING A SPECIAL WEATHER STATEMENT SINCE THE SLEET WILL LIKELY BE FALLING DURING THE MORNING COMMUTE. ITS IMPORTANT TO STRESS THAT THIS WILL BE A NON- EVENT. EXTENSIVE CLOUD COVER COUPLED WITH ONGOING VERY LIGHT RAIN WILL LIMIT HIGHS TO THE 50S FOR MOST PLACED WITH THE POTENTIAL FOR A FEW LOWER 60S NEAR THE DARIEN AND LUDOWICI AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... RAIN CHANCES WILL GRADUALLY DIMINISH THIS EVENING AS A COLD FRONT APPROACHES FROM THE WEST AND THE CORRIDOR OF STRONGEST WARM AIR ADVECTION SHIFTS WELL OFFSHORE. SHOWERS MAY LINGER NEAR THE ALTAMAHA RIVER THROUGH ABOUT MIDNIGHT...BUT SHOULD STEADILY DIMINISH THEREAFTER. GUIDANCE AND SOME SREF MEMBERS SUGGEST LOW CLOUDS WILL FILL IN FROM THE WEST OVERNIGHT WITH MARGINALLY WET GROUNDS AND LIGHT WINDS IN PLACE. LOW CONFIDENCE ON EXACTLY HOW THIS SCENARIO WILL PLAY OUT...ESPECIALLY AS LOW-LEVEL WINDS BECOME MORE DOWNSLOPE DOMINATE IN THE WAKE OF THE FRONT AFTER MIDNIGHT. WILL SHOW MOSTLY CLOUDY SKIES WITH SOME CLEARING ACROSS THE WESTERN ZONES LATE...BUT FURTHER ADJUSTMENTS WILL BE NEEDED LATER TODAY. LOWS WILL RANGE FROM THE UPPER 30 WELL INLAND TO THE UPPER 40S/LOWER 50S AT THE BEACHES. TRANSIENT SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING WILL SUPPORT WARMER TEMPERATURES AND DRY CONDITIONS FOR THE DAYTIME AND EVENING HOURS WEDNESDAY. HIGH TEMPERATURES WILL REACH THE UPPER 60S TO THE LOWER 70S UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES. SHORTWAVE ENERGY WILL RAPIDLY APPROACH WEDNESDAY NIGHT AND BREAK DOWN THE WESTERN PERIPHERY OF THE UPPER RIDGE. A WARM FRONTAL FEATURE WILL BE LIFTING NORTH ACROSS THE FORECAST AREA AFTER MIDNIGHT...AHEAD OF THE COLD FRONT SHIFTING INTO THE SOUTHEAST STATES BY THURSDAY. THICKENING CLOUD COVER WEDNESDAY NIGHT WILL SUPPORT MILDER LOW TEMPERATURES IN THE UPPER 40S TO LOW 50S. ENHANCED MOISTURE CONVERGENCE AND ASCENT WITHIN THE WARM FRONT...AS WELL AS INCREASING UPPER LEVEL SUPPORT...SUGGESTS THAT ISOLATED SHOWERS COULD OCCUR AFTER MIDNIGHT EARLY THURSDAY MORNING FOR MAINLY THE WESTERN HALF OF THE FORECAST AREA. GIVEN DECENT MODEL CONSENSUS THAT THE APPROACHING COLD FRONT WILL HAVE A SUFFICIENT TAP INTO GULF MOISTURE...WILL MAINTAIN SOLID RAIN CHANCES IN THE 30 TO 40 PERCENT RANGE DURING THE DAYTIME HOURS ON THURSDAY. SOUTHERLY FLOW WITHIN THE WARM SECTOR OF THE SYSTEM WILL ALLOW TEMPERATURES TO RISE WELL ABOVE NORMAL...PEAKING IN THE THE UPPER 60S INLAND SOUTH CAROLINA TO THE LOWER 70S NEAR THE ALTAMAHA IN SOUTHEAST GEORGIA. THE COLD FRONT WILL STEADILY SHIFT THROUGH THE FORECAST AREA THURSDAY EVENING...FOLLOWING THE SHORTWAVE ENERGY INTO THE ATLANTIC. HAVE THUS INDICATED DECREASING RAIN CHANCES FROM WEST TO EAST OVERNIGHT. SINCE THE FRONT WILL LIKELY CROSS THE COASTLINE AS LATE AS DAYBREAK FRIDAY...LOW TEMPERATURES WILL BE QUITE MILD DUE TO THE INSULATING EFFECTS OF LINGERING CLOUDS AND MORE PERSISTENT SOUTHERLY FLOW FOR THE MAJORITY OF THURSDAY NIGHT. THE COLD FRONT WILL DESCEND SOUTHEAST AND OFFSHORE ON FRIDAY...BECOMING NEARLY PARALLEL TO ZONAL FLOW ALOFT. SURFACE HIGH PRESSURE WILL SHIFT ACROSS THE MID ATLANTIC AND SOUTHEAST STATES...SUPPRESSING MOST OF THE DEEP MOISTURE TO THE SOUTH OF THE FORECAST AREA WITH THE LINGERING FRONT. WILL THUS KEEP RAIN CHANCES BELOW 15 PERCENT ON FRIDAY. LITTLE TO NO COLD ADVECTION BEHIND THE FRONT SUGGESTS ONLY A SLIGHT DECREASE IN TEMPERATURES FOR FRIDAY...GENERALLY RANGING FROM 68 TO 72 DEGREES DURING THE AFTERNOON. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... THERE REMAINS QUITE A BIT OF UNCERTAINTY IN THE EXTENDED PERIOD...AS MUCH OF THE FORECAST DETAILS WILL BE HIGHLY DEPENDENT ON THE EVOLUTION OF THE LINGERING COLD FRONT TO THE SOUTH AND A POTENTIALLY STRONG GULF LOW SYSTEM DEVELOPING LATE IN THE WEEKEND. LATEST MODEL SOLUTIONS SHOW GENERAL AGREEMENT THAT THE LINGERING BOUNDARY COULD LIFT NORTHWARD AS A WARM FRONT ON SATURDAY...WHILE A STRONG SHORTWAVE ASSISTS IN THE DEVELOPMENT OF A LOW SYSTEM IN THE GULF OF MEXICO. THIS SYSTEM COULD TRACK EAST/NORTHEAST ACROSS THE GULF COAST STATES AND TOWARD THE FORECAST AREA LATE SATURDAY INTO SUNDAY...LIFTING INTO THE ATLANTIC BY MONDAY. SIGNIFICANT MODEL SOLUTION DIFFERENCES IN THE TRACK AND STRENGTH OF THIS LOW SYSTEM LENDS LITTLE CONFIDENCE...AND PREFER TO REMAIN RATHER GENERIC WITH POPS AND TEMPERATURES FOR THE WEEKEND AND INTO EARLY NEXT WEEK. WILL REINTRODUCE PRECIPITATION FROM THE SOUTH WITH THE LIFTING WARM FRONT ON SATURDAY...WITH BEST RAIN CHANCES LATER SATURDAY INTO EARLY SUNDAY WHEN THE SYSTEM COULD BE IMPACTING THE SOUTHEAST STATES. HAVE THEN INDICATED POPS FALLING BELOW 15 PERCENT LATE SUNDAY INTO EARLY NEXT WEEK...AS HIGH PRESSURE FOLLOWS IN THE WAKE OF THE SYSTEM. TEMPERATURES WILL BE DICTATED BY THE TIMING AND EFFECTS OF THE LOW PRESSURE SYSTEM AND ASSOCIATED FRONTS THROUGH THE WEEKEND. WILL MENTION HIGH TEMPERATURES GENERALLY IN THE 60S SUNDAY THROUGH TUESDAY...HOWEVER THIS FORECAST WILL LIKELY BE MODIFIED QUITE A BIT DEPENDING ON THE TRACK OF THE SURFACE LOW. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... KCHS...MAINLY VFR THROUGH SUNSET WITH A POTENTIAL FOR IFR OR MVFR CIGS OVERNIGHT IN THE WAKE OF A COLD FRONT. LIGHT PCPN EXPECTED TO REMAIN SOUTH OF KCHS CLOSER TO THE KNBC-KSAV-KLHW CORRIDOR. CONFIDENCE FOR LOW CIGS TONIGHT IS LOW AS FORECAST SOUNDING SHOW ONLY A THIN RIBBON OF MOISTURE LINGERING AFTER SUNSET. TABULAR GUIDANCE HINTING AT A WINDOW OF 09-12Z FOR TIME FOR IFR CONDITIONS. SINCE THIS IS AT THE END OF THE 12Z TAF PERIOD OPTED TO CAP CIGS AT MVFR FOR NOW. KSAV...LIGHT RAIN IS EXPECTED TO SPREAD INTO THE TERMINAL SHORTLY. THE RAIN WILL BE RATHER LIGHT IN INTENSITY BUT MAY PRODUCE A FEW HOURS OF HIGH-END MVFR CIGS/VSBYS ROUGHLY 16-19Z. A FEW SLEET PELLETS MAY ALSO MIX IN AT TIMES AT THE ONSET. SHOWER ACTIVITY EXPECTED TO PUSH SOUTH AND SOUTHEAST OF THE TERMINAL DURING THE AFTERNOON. THERE IS A POTENTIAL FOR MVFR OR IFR CIGS DEVELOPING TONIGHT IN THE WAKE OF A COLD FRONT. CONFIDENCE FOR LOW CIGS TONIGHT IS LOW AS FORECAST SOUNDING SHOW ONLY A THIN RIBBON OF MOISTURE LINGERING AFTER SUNSET. TABULAR GUIDANCE HINTING AT A WINDOW OF 06-12Z FOR TIME OF MVFR-IFR CONDITIONS. WILL CAP CIGS AT MVFR FOR NOW UNTIL CONFIDENCE INCREASES. EXTENDED AVIATION OUTLOOK...REDUCED CEILINGS/VISIBILITIES ARE POSSIBLE LATE THURSDAY AS A COLD FRONT MOVES THROUGH THE AREA. && .MARINE... A VERY LIGHT WIND REGIME WILL DOMINATE ACROSS THE WATERS THROUGH TONIGHT. SEAS WILL REMAIN GENERALLY 2 FT OR LESS. WEDNESDAY THROUGH SATURDAY...MARINE CONDITIONS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS THROUGH MID WEEK AS HIGH PRESSURE MOVES ACROSS THE AREA. A SURGE IN SOUTHERLY FLOW WILL OCCUR AHEAD OF THE NEXT COLD FRONT CROSSING THE COASTLINE ON THURSDAY. HOWEVER...THE WARM ADVECTION REGIME ON THURSDAY AND LACK OF STRONG COLD ADVECTION BEHIND THE SYSTEM SUGGEST THAT CONDITIONS WILL STILL REMAIN BELOW ADVISORY CRITERIA. THERE IS A LOT OF FORECAST UNCERTAINTY OVER THE WEEKEND...AS THE FRONT LINGERS TO THE SOUTH AND A GULF OF MEXICO LOW SYSTEM DEVELOPS. WILL INDICATE INCREASING NORTH/NORTHEAST FLOW BEHIND THE COLD FRONT BY SATURDAY...WHILE KEEPING CONDITIONS JUST BELOW ADVISORY THRESHOLDS AT THIS TIME. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
716 AM EST TUE FEB 14 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 458 AM EST TUE FEB 14 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A WELL-DEFINED MID/UPPER LEVEL SHORTWAVE TROUGH MOVING ACROSS THE MID-MISSISSIPPI VALLEY EARLY THIS MORNING WITH CONFLUENT FLOW FROM NRN ONTARIO INTO THE NRN LAKES ON THE PERIPHERY OF THE DEEP TROUGH OVER ERN CANADA. LATEST RADAR IMAGERY SHOWED THAT THE NRN EDGE OF THE PCPN SHIELD WITH THIS SYSTEM HAD ADVANCED INTO SCNTRL AND ERN UPR MI WITH SFC OBS INDICATING LIGHT SNOW OR FLURRIES. AT THE SFC...A MOIST SRLY FLOW PREVAILED FROM MO/IA INTO WI AND UPPER MI AHEAD OF A TROUGH OVER THE PLAINS. IR SATELLITE REVEALED EXTENSIVE LOW TO MID CLOUD COVER ACROSS THE MIDWEST AND GREAT LAKES REGION ASSOC WITH THE SHORTWAVE. TODAY...EXPECT LIGHT SNOW OVER SCNTRL AND ERN COUNTIES TO DIMINISH OR END THROUGH THE MORNING HOURS AS SUPPORTING 700-600 MB FGEN FORCING WEAKENS AND SHIFTS EAST WITH DEPARTING SHORTWAVE. NAM/GFS BUFR SNDGS SUGGEST LOW-LVL MOISTURE AND CLOUDS WILL REMAIN THROUGH THE DAY EVEN AFTER THE SNOW ENDS. HOWEVER...MAX READINGS SHOULD STILL CLIMB INTO THE LOWER TO MID 30S...DESPITE THE LINGERING CLOUDS. TONIGHT...ANOTHER SHORTWAVE NOW OVER THE DAKOTAS IS EXPECTED MOVE EAST REACHING THE UPPER GREAT LAKES LATE TONIGHT. MODEST 285K ISENTROPIC ASCENT AND LOWERING OF CONDENSATION PRES DEFICITS ASSOC WITH THIS FEATURE COULD RESULT IN A LITTLE LIGHT SNOW OR FLURRIES LATE TONIGHT INTO WED. SINCE RADAR IS ONLY SHOWING ISOLD TO SCT COVERAGE UPSTREAM WILL ONLY INCLUDE SLIGHT CHC POPS FOR LATE TONIGHT OVER MAINLY WRN AND CENTRAL PORTIONS OF THE CWA. LOOK FOR MINS TONIGHT TO RANGE MAINLY IN THE LOWER 20S OVER THE WRN INTERIOR TO THE MID 20S NEAR THE GREAT LAKES AND EAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 458 AM EST TUE FEB 14 2012 WEAK SHORTWAVE WILL BE MOVING THROUGH THE CWA WED MORNING. WITH THE SHORTWAVE...DECENT H925-700 MOISTURE...AND H850-700 Q-VECTOR CONV THINK THERE IS A POTENTIAL FOR A FEW LIGHT SNOW SHOWERS MOVING FROM W TO E ACROSS THE CWA IN THE MORNING AND EARLY AFTN. THUS...ADDED SLIGHT CHANCES INTO THE FORECAST BUT DON/T REALLY EXPECT MUCH IF ANY ACCUM. AS THE SHORTWAVE MOVES E THROUGH THE DAY...STRONGER NRN STREAM SHORTWAVE WILL BE MOVING OUT OF THE DAKOTAS AND INTO MN. BRIEF PERIOD OF DRYING BEHIND THE DISTURBANCE COULD LEAD TO SOME BREAKS IN THE CLOUDS. THESE BREAKS WILL LARGELY DEPEND ON IF MOISTURE REMAINS TRAPPED BELOW THE 1.5-3KFT INVERSION FROM THE WAA AND DRYING ALOFT. THINK IT SHOULD STICK AROUND AND WILL KEEP SKIES MOSTLY CLOUDY. LAND AREA WILL LIKELY BE BETWEEN SYSTEMS ON WED EVENING. NRN STREAM ENERGY SHORTWAVE AND APPROACHING SFC TROUGH FROM LOW IN CNTRL CANADA WILL LEAD TO A GLANCING BLOW OVER THE NW HALF OF LK SUPERIOR. MEANWHILE...SRN STREAM ENERGY AND LOW WILL BE PUSHING OUT OF THE CNTRL PLAINS. DID START TO INCREASE POPS THROUGH THE OVERNIGHT HOURS...AS SFC TROUGH BEGINS TO SLIDE INTO THE AREA AND H850-500 Q-VECTOR CONV AND MOISTURE INCREASES. BEST CHANCES WILL BE OVER NRN LK SUPERIOR CLOSER TO THE NRN STREAM SHORTWAVE AND OVER SCNTRL UPPER MI CLOSER TO THE SFC LOW MOVING INTO THE LOWER GREAT LKS. MODEL DIFFERENCES REALLY BECOME APPARENT HEADING INTO THURSDAY...WITH NAM/GFS IN ONE CAMP AND THE ECMWF/UKMET/GEM IN THE OTHER. THIS IS NORMALLY THE CASE IN PHASING OF NRN/SRN STREAM SYSTEMS AND LEAVES LOW CONF IN THE FCST. THE NAM/GFS HAVE A MUCH STRONGER/SHARPER NRN STREAM WAVE AND THUS ENDS UP DOMINATING THE PHASING AND KEEPS THE LOW ASSOCIATED WITH THE SRN STREAM SUPPRESSED AND JUST SWEEPS THE SFC TROUGH ACROSS THE AREA. THE 00Z NAM ACTUALLY DOESN/T BRING ANY PCPN TO THE AREA...WHILE THE 00Z GFS ONLY BRINGS A FEW HUNDREDTHS. THE OTHER GROUPING HAS A WEAKER NRN STREAM AND ALLOWS SRN STREAM TO TRACK A MID 1000S SFC LOW FROM THE CNTRL PLAINS ON WED INTO THE LOWER GREAT LKS BY THURS AFTN. OVERALL CONSENSUS WITH THESE MODELS IS TO HAVE THE LOW TRACK NEAR DETROIT...ALTHOUGH THE 00Z GEM HAS SLID THE LOW FARTHER TO THE NW AND IN CNTRL LOWER MI. 21Z SREF EVEN SHOWING THESE DIFFERENCES WITH THE ENS MEAN SFC TRACKING THROUGH CNTRL LOWER MI. LOOKING AT THE INDIVIDUAL MEMBERS...THERE IS A LARGE CLUSTER OF WRF ARW/NMM MEMBERS HAVING THE LOW IN CNTRL LOWER MI...WHILE THE ETA/RSM MEMBERS KEEP IT IN THE OHIO RIVER VALLEY. HPC PREFERS THE WEAKER NRN STREAM SOLN...SO HAVE FOLLOWED THAT FOR THURS. WITH THE PREFERENCE TOWARDS THE ECMWF SOLN...EXPECT AREA OF SNOW TO QUICKLY SLIDE ACROSS THE SE HALF OF THE CWA THURS MORN AND INTO EARLY AFTN. DECENT H850-700 Q-VECTOR CONV AND MOISTURE OVER THE AREA...BUT THE BETTER WAA STAYS SE OF THE AREA AND CLOSER TO THE LOW. DEPENDING ON THE EXACT TRACK OF THE LOW...SNOW AMNTS WILL FLUCTUATE TO THE NW OR SE BUT CURRENTLY HAVE 1-3IN ALONG THE LK MI SHORELINE. ALSO ADJUSTED THE EXISTING LIKELYS OVER PORTIONS OF THE ERN CWA TO LINE UP ALONG THE LK MI SHORELINE AND JUST HAVE CHANCES ELSEWHERE. WITH THE LOW CONF ON OCCURRENCE AND SUB ADVY VALUES...WILL LEAVE MENTION OUT OF THE HWO. AS THE ENERGY SLIDES ENE DURING THE AFTN...SHOULD SEE A DIMINISHING TREND FROM W TO E IN THE PCPN. COLDER AIR WILL START TO FILTER IN BEHIND THE LOW/TROUGH AND COULD LEAD TO SOME LK EFFECT PCPN AS H850 TEMPS FALL TOWARDS -10C BY 00Z FRI. LINGERED SOME CHANCES OVER THE FAR WRN CWA TO ACCOUNT FOR THIS. H850 TEMPS WILL GRADUALLY FALL TOWARDS -12C THURS NIGHT. WITH WNW WINDS...HAVE CHANCE LES POPS IN AREAS FAVORED BY THAT WIND DIRECTION. BUFKIT SOUNDINGS SHOWING WELL MIXED LLVLS WHICH SHOULD LIMIT INTENSITY OF THE BANDS. DAYS 4 THROUGH 7 /FRIDAY THROUGH MONDAY/... NEXT SHORTWAVE MOVING AROUND THE UPPER LOW STATIONED OVER ERN CANADA WILL IMPACT THE AREA ON FRI. STILL DECENT DIFFERENCES IN THE INTENSITY/LOCATION OF THE WAVE...BUT IT SHOULD PULL ADDITIONAL MOISTURE INTO THE AREA AND PROVIDE AN UPTICK IN THE ONGOING LES. NOT A WHOLE LOT OF AGREEMENT HEADING THE REST OF THE WAY THROUGH THE EXTENDED FORECAST PERIOD...AS EXTENDED MODELS CONTINUE TO STRUGGLE WITH THE NRN/SRN STREAMS COMING TOGETHER OVER THE NEW ENGLAND STATES. LIKELY WILL SEE NW FLOW ALOFT AND THE POTENTIAL FOR SHORTWAVES TO MOVE ACROSS THE AREA. CONTINUED LES CHANCES FOR NW WINDS FAVORED LOCATIONS FRI NIGHT INTO SAT NIGHT. H850 TEMPS PEAK AROUND -15C ON FRI NIGHT INTO SAT MORNING AND THEN GRADUALLY WARM THROUGH THE REST OF THE WEEKEND. WITH DECENT LLVL MOISTURE AT THAT TIME AND INVERSION HEIGHTS AROUND 5KFT...EXPECT LIGHT TO MODERATE LES TO CONTINUE FOR NW WIND FAVORED LOCATIONS. MUCH OF THE LES CLOUD SHOULD BE WITHIN THE DGZ...SO THE POTENTIAL EXISTS FOR NEAR ADVY CRITERIA SNOW AMNTS FRI NIGHT INTO SAT. BEST CHANCE WOULD BE E OF MUNISING WHERE THE LONGER FETCH WILL AID INTENSITY. HAVE BUMPED POPS UP SIGNIFICANTLY IN THAT AREA TO HIGH END CHANCES. AS H850 TEMPS SLOWLY WARM AND DRIER AIR STARTS TO ARRIVE...TAPERED POPS DOWN SAT NIGHT INTO SUN. H850 RIDGE WILL LIKELY MOVE OVER THE CWA HEADING INTO MON...BRINGING WARMER H850 TEMPS AND DRIER AIR. OVERALL TEMPS LOOK TO REMAIN NORMAL TO ABOVE NORMAL THROUGH THE FIRST PART OF NEXT WEEK WITH NO MAJOR SNOW EVENTS ON THE HORIZON. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 716 AM EST TUE FEB 14 2012 EXTENSIVE LOW CLOUD COVER ASSOC WITH THE LOW PRES SYSTEM MOVING THROUGH THE OHIO VALLEY WILL KEEP MOST OF THE TAF SITES UNDER MVFR CIGS TODAY. ANOTHER LOW PRES SYSTEM APPROACHING FROM THE NRN PLAINS LATE TONIGHT SHOULD CONTINUE TO KEEP MVFR CIGS ACROSS THE REGION. THERE COULD BE A CHANCE OF SOME LIGHT SNOW BTWN 09-12Z AT KCMX AND KIWD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 458 AM EST TUE FEB 14 2012 A SERIES OF WEAK LOW PRESSURE TROUGHS MOVING THROUGH THE AREA WILL KEEP WINDS BELOW 20KTS TODAY THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS ON WED NIGHT WILL MOVE THROUGH THE GREAT LAKES REGION FROM THURSDAY INTO FRIDAY. THIS WILL LEAD TO NW WINDS UP TO 25KTS OVER ERN LK SUPERIOR. HIGH PRESSURE WILL THEN MOVE OVER THE AREA FOR THE FIRST PART OF THE WEEKEND AND KEEP WINDS BELOW 20KTS. WITH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...LITTLE TO NO FREEZING SPRAY IS EXPECTED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION...CORRECTED
NWS MARQUETTE MI
508 AM EST TUE FEB 14 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 458 AM EST TUE FEB 14 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A WELL-DEFINED MID/UPPER LEVEL SHORTWAVE TROUGH MOVING ACROSS THE MID-MISSISSIPPI VALLEY EARLY THIS MORNING WITH CONFLUENT FLOW FROM NRN ONTARIO INTO THE NRN LAKES ON THE PERIPHERY OF THE DEEP TROUGH OVER ERN CANADA. LATEST RADAR IMAGERY SHOWED THAT THE NRN EDGE OF THE PCPN SHIELD WITH THIS SYSTEM HAD ADVANCED INTO SCNTRL AND ERN UPR MI WITH SFC OBS INDICATING LIGHT SNOW OR FLURRIES. AT THE SFC...A MOIST SRLY FLOW PREVAILED FROM MO/IA INTO WI AND UPPER MI AHEAD OF A TROUGH OVER THE PLAINS. IR SATELLITE REVEALED EXTENSIVE LOW TO MID CLOUD COVER ACROSS THE MIDWEST AND GREAT LAKES REGION ASSOC WITH THE SHORTWAVE. TODAY...EXPECT LIGHT SNOW OVER SCNTRL AND ERN COUNTIES TO DIMINISH OR END THROUGH THE MORNING HOURS AS SUPPORTING 700-600 MB FGEN FORCING WEAKENS AND SHIFTS EAST WITH DEPARTING SHORTWAVE. NAM/GFS BUFR SNDGS SUGGEST LOW-LVL MOISTURE AND CLOUDS WILL REMAIN THROUGH THE DAY EVEN AFTER THE SNOW ENDS. HOWEVER...MAX READINGS SHOULD STILL CLIMB INTO THE LOWER TO MID 30S...DESPITE THE LINGERING CLOUDS. TONIGHT...ANOTHER SHORTWAVE NOW OVER THE DAKOTAS IS EXPECTED MOVE EAST REACHING THE UPPER GREAT LAKES LATE TONIGHT. MODEST 285K ISENTROPIC ASCENT AND LOWERING OF CONDENSATION PRES DEFICITS ASSOC WITH THIS FEATURE COULD RESULT IN A LITTLE LIGHT SNOW OR FLURRIES LATE TONIGHT INTO WED. SINCE RADAR IS ONLY SHOWING ISOLD TO SCT COVERAGE UPSTREAM WILL ONLY INCLUDE SLIGHT CHC POPS FOR LATE TONIGHT OVER MAINLY WRN AND CENTRAL PORTIONS OF THE CWA. LOOK FOR MINS TONIGHT TO RANGE MAINLY IN THE LOWER 20S OVER THE WRN INTERIOR TO THE MID 20S NEAR THE GREAT LAKES AND EAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 458 AM EST TUE FEB 14 2012 WEAK SHORTWAVE WILL BE MOVING THROUGH THE CWA WED MORNING. WITH THE SHORTWAVE...DECENT H925-700 MOISTURE...AND H850-700 Q-VECTOR CONV THINK THERE IS A POTENTIAL FOR A FEW LIGHT SNOW SHOWERS MOVING FROM W TO E ACROSS THE CWA IN THE MORNING AND EARLY AFTN. THUS...ADDED SLIGHT CHANCES INTO THE FORECAST BUT DON/T REALLY EXPECT MUCH IF ANY ACCUM. AS THE SHORTWAVE MOVES E THROUGH THE DAY...STRONGER NRN STREAM SHORTWAVE WILL BE MOVING OUT OF THE DAKOTAS AND INTO MN. BRIEF PERIOD OF DRYING BEHIND THE DISTURBANCE COULD LEAD TO SOME BREAKS IN THE CLOUDS. THESE BREAKS WILL LARGELY DEPEND ON IF MOISTURE REMAINS TRAPPED BELOW THE 1.5-3KFT INVERSION FROM THE WAA AND DRYING ALOFT. THINK IT SHOULD STICK AROUND AND WILL KEEP SKIES MOSTLY CLOUDY. LAND AREA WILL LIKELY BE BETWEEN SYSTEMS ON WED EVENING. NRN STREAM ENERGY SHORTWAVE AND APPROACHING SFC TROUGH FROM LOW IN CNTRL CANADA WILL LEAD TO A GLANCING BLOW OVER THE NW HALF OF LK SUPERIOR. MEANWHILE...SRN STREAM ENERGY AND LOW WILL BE PUSHING OUT OF THE CNTRL PLAINS. DID START TO INCREASE POPS THROUGH THE OVERNIGHT HOURS...AS SFC TROUGH BEGINS TO SLIDE INTO THE AREA AND H850-500 Q-VECTOR CONV AND MOISTURE INCREASES. BEST CHANCES WILL BE OVER NRN LK SUPERIOR CLOSER TO THE NRN STREAM SHORTWAVE AND OVER SCNTRL UPPER MI CLOSER TO THE SFC LOW MOVING INTO THE LOWER GREAT LKS. MODEL DIFFERENCES REALLY BECOME APPARENT HEADING INTO THURSDAY...WITH NAM/GFS IN ONE CAMP AND THE ECMWF/UKMET/GEM IN THE OTHER. THIS IS NORMALLY THE CASE IN PHASING OF NRN/SRN STREAM SYSTEMS AND LEAVES LOW CONF IN THE FCST. THE NAM/GFS HAVE A MUCH STRONGER/SHARPER NRN STREAM WAVE AND THUS ENDS UP DOMINATING THE PHASING AND KEEPS THE LOW ASSOCIATED WITH THE SRN STREAM SUPPRESSED AND JUST SWEEPS THE SFC TROUGH ACROSS THE AREA. THE 00Z NAM ACTUALLY DOESN/T BRING ANY PCPN TO THE AREA...WHILE THE 00Z GFS ONLY BRINGS A FEW HUNDREDTHS. THE OTHER GROUPING HAS A WEAKER NRN STREAM AND ALLOWS SRN STREAM TO TRACK A MID 1000S SFC LOW FROM THE CNTRL PLAINS ON WED INTO THE LOWER GREAT LKS BY THURS AFTN. OVERALL CONSENSUS WITH THESE MODELS IS TO HAVE THE LOW TRACK NEAR DETROIT...ALTHOUGH THE 00Z GEM HAS SLID THE LOW FARTHER TO THE NW AND IN CNTRL LOWER MI. 21Z SREF EVEN SHOWING THESE DIFFERENCES WITH THE ENS MEAN SFC TRACKING THROUGH CNTRL LOWER MI. LOOKING AT THE INDIVIDUAL MEMBERS...THERE IS A LARGE CLUSTER OF WRF ARW/NMM MEMBERS HAVING THE LOW IN CNTRL LOWER MI...WHILE THE ETA/RSM MEMBERS KEEP IT IN THE OHIO RIVER VALLEY. HPC PREFERS THE WEAKER NRN STREAM SOLN...SO HAVE FOLLOWED THAT FOR THURS. WITH THE PREFERENCE TOWARDS THE ECMWF SOLN...EXPECT AREA OF SNOW TO QUICKLY SLIDE ACROSS THE SE HALF OF THE CWA THURS MORN AND INTO EARLY AFTN. DECENT H850-700 Q-VECTOR CONV AND MOISTURE OVER THE AREA...BUT THE BETTER WAA STAYS SE OF THE AREA AND CLOSER TO THE LOW. DEPENDING ON THE EXACT TRACK OF THE LOW...SNOW AMNTS WILL FLUCTUATE TO THE NW OR SE BUT CURRENTLY HAVE 1-3IN ALONG THE LK MI SHORELINE. ALSO ADJUSTED THE EXISTING LIKELYS OVER PORTIONS OF THE ERN CWA TO LINE UP ALONG THE LK MI SHORELINE AND JUST HAVE CHANCES ELSEWHERE. WITH THE LOW CONF ON OCCURRENCE AND SUB ADVY VALUES...WILL LEAVE MENTION OUT OF THE HWO. AS THE ENERGY SLIDES ENE DURING THE AFTN...SHOULD SEE A DIMINISHING TREND FROM W TO E IN THE PCPN. COLDER AIR WILL START TO FILTER IN BEHIND THE LOW/TROUGH AND COULD LEAD TO SOME LK EFFECT PCPN AS H850 TEMPS FALL TOWARDS -10C BY 00Z FRI. LINGERED SOME CHANCES OVER THE FAR WRN CWA TO ACCOUNT FOR THIS. H850 TEMPS WILL GRADUALLY FALL TOWARDS -12C THURS NIGHT. WITH WNW WINDS...HAVE CHANCE LES POPS IN AREAS FAVORED BY THAT WIND DIRECTION. BUFKIT SOUNDINGS SHOWING WELL MIXED LLVLS WHICH SHOULD LIMIT INTENSITY OF THE BANDS. DAYS 4 THROUGH 7 /FRIDAY THROUGH MONDAY/... NEXT SHORTWAVE MOVING AROUND THE UPPER LOW STATIONED OVER ERN CANADA WILL IMPACT THE AREA ON FRI. STILL DECENT DIFFERENCES IN THE INTENSITY/LOCATION OF THE WAVE...BUT IT SHOULD PULL ADDITIONAL MOISTURE INTO THE AREA AND PROVIDE AN UPTICK IN THE ONGOING LES. NOT A WHOLE LOT OF AGREEMENT HEADING THE REST OF THE WAY THROUGH THE EXTENDED FORECAST PERIOD...AS EXTENDED MODELS CONTINUE TO STRUGGLE WITH THE NRN/SRN STREAMS COMING TOGETHER OVER THE NEW ENGLAND STATES. LIKELY WILL SEE NW FLOW ALOFT AND THE POTENTIAL FOR SHORTWAVES TO MOVE ACROSS THE AREA. CONTINUED LES CHANCES FOR NW WINDS FAVORED LOCATIONS FRI NIGHT INTO SAT NIGHT. H850 TEMPS PEAK AROUND -15C ON FRI NIGHT INTO SAT MORNING AND THEN GRADUALLY WARM THROUGH THE REST OF THE WEEKEND. WITH DECENT LLVL MOISTURE AT THAT TIME AND INVERSION HEIGHTS AROUND 5KFT...EXPECT LIGHT TO MODERATE LES TO CONTINUE FOR NW WIND FAVORED LOCATIONS. MUCH OF THE LES CLOUD SHOULD BE WITHIN THE DGZ...SO THE POTENTIAL EXISTS FOR NEAR ADVY CRITERIA SNOW AMNTS FRI NIGHT INTO SAT. BEST CHANCE WOULD BE E OF MUNISING WHERE THE LONGER FETCH WILL AID INTENSITY. HAVE BUMPED POPS UP SIGNIFICANTLY IN THAT AREA TO HIGH END CHANCES. AS H850 TEMPS SLOWLY WARM AND DRIER AIR STARTS TO ARRIVE...TAPERED POPS DOWN SAT NIGHT INTO SUN. H850 RIDGE WILL LIKELY MOVE OVER THE CWA HEADING INTO MON...BRINGING WARMER H850 TEMPS AND DRIER AIR. OVERALL TEMPS LOOK TO REMAIN NORMAL TO ABOVE NORMAL THROUGH THE FIRST PART OF NEXT WEEK WITH NO MAJOR SNOW EVENTS ON THE HORIZON. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1249 AM EST TUE FEB 14 2012 A DISTURBANCE MOVING FROM THE CNTRAL PLAINS TO THE LOWER GREAT LAKES WILL CONTINUE TO HAVE THE LOWER CLOUDS LOWER THROUGH THE NIGHT AND LIKELY BE IN THE MVFR CAT AFTER 09Z AT ALL SITES. ONCE THESE CLOUDS ARE IN THE MVFR CIG RANGE...THEY WILL STAY THROUGH THE FORECAST PERIOD AT ALL SITES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 458 AM EST TUE FEB 14 2012 A SERIES OF WEAK LOW PRESSURE TROUGHS MOVING THROUGH THE AREA WILL KEEP WINDS BELOW 20KTS TODAY THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS ON WED NIGHT WILL MOVE THROUGH THE GREAT LAKES REGION FROM THURSDAY INTO FRIDAY. THIS WILL LEAD TO NW WINDS UP TO 25KTS OVER ERN LK SUPERIOR. HIGH PRESSURE WILL THEN MOVE OVER THE AREA FOR THE FIRST PART OF THE WEEKEND AND KEEP WINDS BELOW 20KTS. WITH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...LITTLE TO NO FREEZING SPRAY IS EXPECTED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
500 AM EST TUE FEB 14 2012 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 458 AM EST TUE FEB 14 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A WELL-DEFINED MID/UPPER LEVEL SHORTWAVE TROUGH MOVING ACROSS THE MID-MISSISSIPPI VALLEY EARLY THIS MORNING WITH CONFLUENT FLOW FROM NRN ONTARIO INTO THE NRN LAKES ON THE PERIPHERY OF THE DEEP TROUGH OVER ERN CANADA. LATEST RADAR IMAGERY SHOWED THAT THE NRN EDGE OF THE PCPN SHIELD WITH THIS SYSTEM HAD ADVANCED INTO SCNTRL AND ERN UPR MI WITH SFC OBS INDICATING LIGHT SNOW OR FLURRIES. AT THE SFC...A MOIST SRLY FLOW PREVAILED FROM MO/IA INTO WI AND UPPER MI AHEAD OF A TROUGH OVER THE PLAINS. IR SATELLITE REVEALED EXTENSIVE LOW TO MID CLOUD COVER ACROSS THE MIDWEST AND GREAT LAKES REGION ASSOC WITH THE SHORTWAVE. TODAY...EXPECT LIGHT SNOW OVER SCNTRL AND ERN COUNTIES TO DIMINISH OR END THROUGH THE MORNING HOURS AS SUPPORTING 700-600 MB FGEN FORCING WEAKENS AND SHIFTS EAST WITH DEPARTING SHORTWAVE. NAM/GFS BUFR SNDGS SUGGEST LOW-LVL MOISTURE AND CLOUDS WILL REMAIN THROUGH THE DAY EVEN AFTER THE SNOW ENDS. HOWEVER...MAX READINGS SHOULD STILL CLIMB INTO THE LOWER TO MID 30S...DESPITE THE LINGERING CLOUDS. TONIGHT...ANOTHER SHORTWAVE NOW OVER THE DAKOTAS IS EXPECTED MOVE EAST REACHING THE UPPER GREAT LAKES LATE TONIGHT. MODEST 285K ISENTROPIC ASCENT AND LOWERING OF CONDENSATION PRES DEFICITS ASSOC WITH THIS FEATURE COULD RESULT IN A LITTLE LIGHT SNOW OR FLURRIES LATE TONIGHT INTO WED. SINCE RADAR IS ONLY SHOWING ISOLD TO SCT COVERAGE UPSTREAM WILL ONLY INCLUDE SLIGHT CHC POPS FOR LATE TONIGHT OVER MAINLY WRN AND CENTRAL PORTIONS OF THE CWA. LOOK FOR MINS TONIGHT TO RANGE MAINLY IN THE LOWER 20S OVER THE WRN INTERIOR TO THE MID 20S NEAR THE GREAT LAKES AND EAST. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 458 AM EST TUE FEB 14 2012 WEAK SHORTWAVE WILL BE MOVING THROUGH THE CWA WED MORNING. WITH THE SHORTWAVE...DECENT H925-700 MOISTURE...AND H850-700 Q-VECTOR CONV THINK THERE IS A POTENTIAL FOR A FEW LIGHT SNOW SHOWERS MOVING FROM W TO E ACROSS THE CWA IN THE MORNING AND EARLY AFTN. THUS...ADDED SLIGHT CHANCES INTO THE FORECAST BUT DON/T REALLY EXPECT MUCH IF ANY ACCUM. AS THE SHORTWAVE MOVES E THROUGH THE DAY...STRONGER NRN STREAM SHORTWAVE WILL BE MOVING OUT OF THE DAKOTAS AND INTO MN. BRIEF PERIOD OF DRYING BEHIND THE DISTURBANCE COULD LEAD TO SOME BREAKS IN THE CLOUDS. THESE BREAKS WILL LARGELY DEPEND ON IF MOISTURE REMAINS TRAPPED BELOW THE 1.5-3KFT INVERSION FROM THE WAA AND DRYING ALOFT. THINK IT SHOULD STICK AROUND AND WILL KEEP SKIES MOSTLY CLOUDY. LAND AREA WILL LIKELY BE BETWEEN SYSTEMS ON WED EVENING. NRN STREAM ENERGY SHORTWAVE AND APPROACHING SFC TROUGH FROM LOW IN CNTRL CANADA WILL LEAD TO A GLANCING BLOW OVER THE NW HALF OF LK SUPERIOR. MEANWHILE...SRN STREAM ENERGY AND LOW WILL BE PUSHING OUT OF THE CNTRL PLAINS. DID START TO INCREASE POPS THROUGH THE OVERNIGHT HOURS...AS SFC TROUGH BEGINS TO SLIDE INTO THE AREA AND H850-500 Q-VECTOR CONV AND MOISTURE INCREASES. BEST CHANCES WILL BE OVER NRN LK SUPERIOR CLOSER TO THE NRN STREAM SHORTWAVE AND OVER SCNTRL UPPER MI CLOSER TO THE SFC LOW MOVING INTO THE LOWER GREAT LKS. MODEL DIFFERENCES REALLY BECOME APPARENT HEADING INTO THURSDAY...WITH NAM/GFS IN ONE CAMP AND THE ECMWF/UKMET/GEM IN THE OTHER. THIS IS NORMALLY THE CASE IN PHASING OF NRN/SRN STREAM SYSTEMS AND LEAVES LOW CONF IN THE FCST. THE NAM/GFS HAVE A MUCH STRONGER/SHARPER NRN STREAM WAVE AND THUS ENDS UP DOMINATING THE PHASING AND KEEPS THE LOW ASSOCIATED WITH THE SRN STREAM SUPPRESSED AND JUST SWEEPS THE SFC TROUGH ACROSS THE AREA. THE 00Z NAM ACTUALLY DOESN/T BRING ANY PCPN TO THE AREA...WHILE THE 00Z GFS ONLY BRINGS A FEW HUNDREDTHS. THE OTHER GROUPING HAS A WEAKER NRN STREAM AND ALLOWS SRN STREAM TO TRACK A MID 1000S SFC LOW FROM THE CNTRL PLAINS ON WED INTO THE LOWER GREAT LKS BY THURS AFTN. OVERALL CONSENSUS WITH THESE MODELS IS TO HAVE THE LOW TRACK NEAR DETROIT...ALTHOUGH THE 00Z GEM HAS SLID THE LOW FARTHER TO THE NW AND IN CNTRL LOWER MI. 21Z SREF EVEN SHOWING THESE DIFFERENCES WITH THE ENS MEAN SFC TRACKING THROUGH CNTRL LOWER MI. LOOKING AT THE INDIVIDUAL MEMBERS...THERE IS A LARGE CLUSTER OF WRF ARW/NMM MEMBERS HAVING THE LOW IN CNTRL LOWER MI...WHILE THE ETA/RSM MEMBERS KEEP IT IN THE OHIO RIVER VALLEY. HPC PREFERS THE WEAKER NRN STREAM SOLN...SO HAVE FOLLOWED THAT FOR THURS. WITH THE PREFERENCE TOWARDS THE ECMWF SOLN...EXPECT AREA OF SNOW TO QUICKLY SLIDE ACROSS THE SE HALF OF THE CWA THURS MORN AND INTO EARLY AFTN. DECENT H850-700 Q-VECTOR CONV AND MOISTURE OVER THE AREA...BUT THE BETTER WAA STAYS SE OF THE AREA AND CLOSER TO THE LOW. DEPENDING ON THE EXACT TRACK OF THE LOW...SNOW AMNTS WILL FLUCTUATE TO THE NW OR SE BUT CURRENTLY HAVE 1-3IN ALONG THE LK MI SHORELINE. ALSO ADJUSTED THE EXISTING LIKELYS OVER PORTIONS OF THE ERN CWA TO LINE UP ALONG THE LK MI SHORELINE AND JUST HAVE CHANCES ELSEWHERE. WITH THE LOW CONF ON OCCURRENCE AND SUB ADVY VALUES...WILL LEAVE MENTION OUT OF THE HWO. AS THE ENERGY SLIDES ENE DURING THE AFTN...SHOULD SEE A DIMINISHING TREND FROM W TO E IN THE PCPN. COLDER AIR WILL START TO FILTER IN BEHIND THE LOW/TROUGH AND COULD LEAD TO SOME LK EFFECT PCPN AS H850 TEMPS FALL TOWARDS -10C BY 00Z FRI. LINGERED SOME CHANCES OVER THE FAR WRN CWA TO ACCOUNT FOR THIS. H850 TEMPS WILL GRADUALLY FALL TOWARDS -12C THURS NIGHT. WITH WNW WINDS...HAVE CHANCE LES POPS IN AREAS FAVORED BY THAT WIND DIRECTION. BUFKIT SOUNDINGS SHOWING WELL MIXED LLVLS WHICH SHOULD LIMIT INTENSITY OF THE BANDS. DAYS 4 THROUGH 7 /FRIDAY THROUGH MONDAY/... NEXT SHORTWAVE MOVING AROUND THE UPPER LOW STATIONED OVER ERN CANADA WILL IMPACT THE AREA ON FRI. STILL DECENT DIFFERENCES IN THE INTENSITY/LOCATION OF THE WAVE...BUT IT SHOULD PULL ADDITIONAL MOISTURE INTO THE AREA AND PROVIDE AN UPTICK IN THE ONGOING LES. NOT A WHOLE LOT OF AGREEMENT HEADING THE REST OF THE WAY THROUGH THE EXTENDED FORECAST PERIOD...AS EXTENDED MODELS CONTINUE TO STRUGGLE WITH THE NRN/SRN STREAMS COMING TOGETHER OVER THE NEW ENGLAND STATES. LIKELY WILL SEE NW FLOW ALOFT AND THE POTENTIAL FOR SHORTWAVES TO MOVE ACROSS THE AREA. CONTINUED LES CHANCES FOR NW WINDS FAVORED LOCATIONS FRI NIGHT INTO SAT NIGHT. H850 TEMPS PEAK AROUND -15C ON FRI NIGHT INTO SAT MORNING AND THEN GRADUALLY WARM THROUGH THE REST OF THE WEEKEND. WITH DECENT LLVL MOISTURE AT THAT TIME AND INVERSION HEIGHTS AROUND 5KFT...EXPECT LIGHT TO MODERATE LES TO CONTINUE FOR NW WIND FAVORED LOCATIONS. MUCH OF THE LES CLOUD SHOULD BE WITHIN THE DGZ...SO THE POTENTIAL EXISTS FOR NEAR ADVY CRITERIA SNOW AMNTS FRI NIGHT INTO SAT. BEST CHANCE WOULD BE E OF MUNISING WHERE THE LONGER FETCH WILL AID INTENSITY. HAVE BUMPED POPS UP SIGNIFICANTLY IN THAT AREA TO HIGH END CHANCES. AS H850 TEMPS SLOWLY WARM AND DRIER AIR STARTS TO ARRIVE...TAPERED POPS DOWN SAT NIGHT INTO SUN. H850 RIDGE WILL LIKELY MOVE OVER THE CWA HEADING INTO MON...BRINGING WARMER H850 TEMPS AND DRIER AIR. OVERALL TEMPS LOOK TO REMAIN NORMAL TO ABOVE NORMAL THROUGH THE FIRST PART OF NEXT WEEK WITH NO MAJOR SNOW EVENTS ON THE HORIZON. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1249 AM EST TUE FEB 14 2012 A DISTURBANCE MOVING FROM THE CNTRAL PLAINS TO THE LOWER GREAT LAKES WILL CONTINUE TO HAVE THE LOWER CLOUDS LOWER THROUGH THE NIGHT AND LIKELY BE IN THE MVFR CAT AFTER 09Z AT ALL SITES. ONCE THESE CLOUDS ARE IN THE MVFR CIG RANGE...THEY WILL STAY THROUGH THE FORECAST PERIOD AT ALL SITES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 458 AM EST TUE FEB 14 2012 A SERIES OF WEAK LOW PRESSURE TROUGHS MOVING THROUGH THE AREA WILL KEEP WINDS BELOW 20KTS TODAY THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS ON WED NIGHT WILL MOVE THROUGH THE GREAT LAKES REGION FROM THURSDAY INTO FRIDAY. THIS WILL LEAD TO NW WINDS UP TO 25KTS OVER ERN LK SUPERIOR. HIGH PRESSURE WILL THEN MOVE OVER THE AREA FOR THE FIRST PART OF THE WEEKEND AND KEEP WINDS BELOW 20KTS. WITH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...LITTLE TO NO FREEZING SPRAY IS EXPECTED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
536 AM CST TUE FEB 14 2012 .SHORT TERM...TODAY THROUGH THURSDAY 353 AM CST TUE FEB 14 2012 AT 3 AM...KARX RADAR SHOWED A DEFORMATION BAND OF LIGHT SNOW MOVING EAST ACROSS THE FORECAST AREA. THE WESTERN EDGE WAS LOCATED FROM MONDOVI WISCONSIN TO CHARLES CITY IOWA. THE LATEST RUC SHOWS THAT THE 800-700 MB FRONTOGENESIS ASSOCIATED WITH THIS BAND WILL CONTINUE TO MOVE EAST THIS MORNING AND GRADUALLY WEAKEN. AT THE SAME TIME...THE SOUNDINGS SHOW THAT THE MOISTURE BELOW 850 MB WILL GRADUALLY DRY. EVEN THOUGH IT IS DRYING OUT...THERE CONTINUES TO BE SOME ICE CRYSTALS SEEDING FROM ALOFT TO KEEP THE PRECIPITATION IN THE FORM OF SNOW. DUE TO THIS JUST WENT WITH SOME FLURRIES THIS MORNING. FOR TONIGHT...THE 14.00Z MODELS SUGGEST THAT A PV ANOMALY WILL MOVE EAST THROUGH CENTRAL MINNESOTA AND NORTHERN WISCONSIN. MODEL SOUNDINGS SHOW SOME MOISTURE BETWEEN 925 AND 700 MB. IN THIS SAME LAYER...THERE IS ENOUGH LIFT FOR A BRIEF PERIOD OF LIGHT SNOW ACROSS NORTH CENTRAL WISCONSIN. THE NAM/WRF...GFS...AND GEM GENERATE SOME LIGHT PRECIPITATION ACROSS THIS AREA. DUE TO THIS...ADDED A SLIGHT CHANCE TO THE FORECAST FOR TONIGHT. FROM WEDNESDAY AFTERNOON THROUGH THURSDAY...THE 14.00Z GFS...ECMWF... AND NAM/WRF ARE IN GOOD AGREEMENT THAT A SURFACE LOW WILL TRACK FROM SOUTHWEST MISSOURI NORTHEAST TO SOUTHERN ONTARIO. THIS TRACK IS VERY SIMILAR TO THE 13.12Z MODELS. THE ONE EXCEPTION TO THIS WAS THE GEM WHICH SHOWS THE LOW MOVING FROM KANSAS CITY NORTHEAST TO CHICAGO ILLINOIS. LOOKING AT ITS ENSEMBLE FAMILY...ONLY 3 OF ITS 16 MEMBERS SUPPORT THIS MORE NORTHERN TRACK...AND IN MANY CASES THERE IS NO PRECIPITATION AT ALL IN OUR FORECAST AREA. THE REASON FOR THE MORE SOUTHERN TRACK THAN THE 13.00Z IS HOW THE NORTHERN STREAM SYSTEM MOVING THROUGH SOUTHERN CANADA INTERACTS WITH THE SOUTHERN STREAM SYSTEM MOVING THROUGH THE CENTRAL PLAINS AND MID MISSISSIPPI RIVER VALLEY. THE NORTHERN STREAM IS SYSTEM LESS AMPLIFIED IN ITS LATEST RUNS /WITH THE EXCEPTION OF THE GEM/...AND THIS RESULT IN THE SOUTHERN LOW NOT BEING DRAWN NORTHWARD INTO OUR AREA. DUE TO THIS...TRENDED BOTH WEDNESDAY AFTERNOON AND THURSDAY DRIER. IF THIS TREND CONTINUES...WILL LIKELY HAVE TO GO DRY FOR BOTH OF THESE PERIOD. FOR WEDNESDAY NIGHT...THE PRECIPITATION CHANCES WERE TRENDED FURTHER SOUTHEAST. AT THIS TIME...IT LOOKS LIKE THE ONLY MEASURABLE SNOW WILL BE ACROSS SOUTHWEST WISCONSIN. .LONG TERM...THURSDAY NIGHT THROUGH WASHINGTONS BIRTHDAY 342 AM CST TUE FEB 14 2012 ON WASHINGTONS BIRTHDAY...THE 14.00Z CONTINUES TO SHOW THAT CYCLOGENESIS WILL DEVELOP ACROSS THE DAKOTAS AND THEN MOVE EAST THROUGH THE FORECAST AREA. LIKE THE PAST COUPLE OF DAYS...THE PRECIPITATION TYPE FORECAST IS GREATLY COMPLICATED BY DIFFERENCES IN THE BOUNDARY LAYER TEMPERATURES. FOR THE TIME BEING...JUST WENT WITH A MENTION OF RAIN AND SNOW WITH THIS SYSTEM. && .AVIATION...TODAY AND TONIGHT 536 AM CST TUE FEB 14 2012 IFR TO MVFR STRATUS OVER THE TAF SITES HAS THE POTENTIAL TO LOWER SLIGHTLY DURING THE NEXT FEW HOURS...TO LIFR AT KRST AND IFR AT KLSE. THIS LOWERING IS IN RESPONSE TO MID LEVEL CLOUDS ASSOCIATED WITH -SN MOVING EAST AWAY FROM THE TAF SITES. SOME SITES ACROSS SOUTH CENTRAL MINNESOTA ARE ALREADY LIFR. THE STRATUS SHOULD THEN BEGIN TO BREAK UP EARLY IN THE AFTERNOON...DUE TO A COMBINATION OF DAYTIME HEATING AND AN AREA OF VFR STRATUS OVER DAKOTAS SPREADING EAST INTO THE TAF SITES. MVFR VISIBILITIES ARE ALSO ANTICIPATED TO CLIMB TO VFR BY NOON THANKS TO DAYTIME HEATING. BIG CONCERN TONIGHT IS MONITORING THE CURRENT LIFR/VLIFR STRATUS AND FOG IN SOUTHERN IOWA AND NORTHERN MISSOURI. IF THIS DOES NOT DISSIPATE TODAY...THE SOUTHERLY WINDS TONIGHT COULD ADVECT IT BACK NORTH INTO THE TAF SITES UNDERNEATH THE HIGHER STRATUS ALOFT. IN ADDITION...VISIBILITIES COULD DROP TO MVFR OR LOWER. BECAUSE CONFIDENCE IN THIS SCENARIO IS LOW...FOR NOW HAVE CONTINUED WITH THE PREVIOUS FORECAST IDEA OF MAINTAINING VFR CEILINGS TONIGHT. HOWEVER...DID INCLUDE AN MVFR VISIBILITY AT KRST TO ACCOUNT FOR LINGERING LOW LEVEL MOISTURE. && .ARX WATCHES/WARNINGS/ADVISORIES... 342 AM CST TUE FEB 14 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...AJ
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
941 AM MST TUE FEB 14 2012 .UPDATE...12Z GJT SOUNDING AND CURRENT RADAR/SATELLITE IMAGERY SHOW A RATHER MOIST AND UNSTABLE AIRMASS OVER WESTERN COLORADO. THERE IS ENOUGH MID LEVEL INSTABILITY TO WARRANT A SLIGHT CHANCE OF SNOW SHOWERS SNEAKING ONTO THE NEARBY PLAINS LATE THIS AFTERNOON SO ADDED A LOW COVERAGE OF SNOW SHOWERS IN/NEAR THE FOOTHILLS. LATEST HRRR COMPOSITE REFLECTIVITY SHOWS THIS AS WELL. OTHER THAN THAT...SNOW SHOWERS WILL BECOME MORE WIDESPREAD IN THE HIGH COUNTRY THROUGH THE AFTERNOON AS ALREADY FORECAST. && .AVIATION...ONLY CHANGE WOULD BE TO ADD A LITTLE MORE MID LEVEL CLOUDINESS AND PERHAPS A VCSH WITH ISOLATED SNOW SHOWER POSSIBLY DRIFTING OFF THE FRONT RANGE AFTER 21Z. && .PREV DISCUSSION... /ISSUED 403 AM MST TUE FEB 14 2012/ SHORT TERM...UPPER LEVEL LOW IS CURRENTLY SPINNING OVER SOUTHEAST NEVADA AND SOUTHWEST UTAH. THIS LOW WILL DROP INTO NORTHERN ARIZONA TODAY AND THEN MOVE ACROSS NORTHERN NEW MEXICO TONIGHT. MOISTURE AHEAD OF THIS SYSTEM IS STREAMING OVER WESTERN COLORADO. RADAR SHOWING SCATTERED SHOWERS OVER WESTERN COLORADO. EXPECT THE SHOWERS TO CONTINUE THROUGH THE DAY TODAY AND THIS EVENING. MODELS SHOWING THE BEST PLUME OF MOISTURE STAY NORTH OF I-70. THIS MOISTURE COMBINED WITH WEAK QG LIFT...OROGRAPHIC LIFT AND MID LEVEL INSTABILITY...WILL PRODUCE SNOW...MAINLY OVER THE MOUNTAINS. BEST CHANCE FOR SNOW AND THE HEAVIEST SNOW...WILL BE OVER THE MOUNTAINS OF JACKSON COUNTY AND NORTHERN GRAND COUNTY. EXPECT SNOW AMOUNTS TO BE 1-5 INCHES WITH LOCALLY HIGHER AMOUNTS OVER THE HIGHEST PEAKS OF WESTERN JACKSON COUNTY. TO THE SOUTH OF THIS AREA...INCLUDING SUMMIT COUNTY AND THE I-70 CORRIDOR...ONLY EXPECT 0-2 INCHES OF SNOW THROUGH TONIGHT. FOR NORTHEAST COLORADO...CLOUDS WILL INCREASE THIS AFTERNOON AS THIS SYSTEM NEARS THE REGION. HIGHS TODAY WILL CLIMB ABOVE FREEZING AGAIN. OVER SOUTHERN FOOTHILLS AND PALMER DIVIDE...WARM AIR ADVECTION IN ADVANCE OF THE STORM SYSTEM WILL PUSH HIGHS INTO THE 40S. IN THE FORT COLLINS AND GREELEY AREAS...MORE CLOUD COVER AND NORTHERLY WINDS USHERING COOLER AIR WILL KEEP TEMPERATURES SLIGHTLY BELOW YESTERDAY`S READINGS (LOWER TO MID 40S). MODELS NOT SHOWING ANY PRECIPITATION FOR TONIGHT. CAN NOT RULE OUT A FEW WEAK SNOW SHOWERS...MAINLY THIS EVENING DUE TO WEAK QG ASCENT...MID LEVEL INSTABILITY AND MID LEVEL MOISTURE. LONG TERM...MODELS CONTINUE TO SHOW THE MAIN STORM TRACK REMAINING WELL TO THE SOUTH OF COLORADO DURING THE UPCOMING WEEK. THE NEXT IN THE SERIES OF UPPER AIR PERTABATIONS IS FORECAST TO DIVE ALMOST DUE SOUTH OUT OF THE PACIFIC NORTHWEST AND DOWN THE WEST SIDE OF A BROAD UPPER LEVEL TROUGH OVER THE WESTERN CONUS. BEFORE THIS HAPPENS...THE SHORTWAVE TROUGH PASSING TO THE SOUTH OF COLORADO TODAY/TONIGHT WILL MOVE AWAY FROM COLORADO ON WEDNESDAY RESULTING IN A DECREASE IN SNOW SHOWER COVERAGE IN THE HIGH COUNTRY AND CLEARING SKIES AT LOWER ELEVATIONS DURING THE AFTERNOON. THIS BREAK IN PRECIPITATION WILL BE SHORT-LIVED WITH THE NEXT UPPER AIR SYSTEM MOVING OVER THE LOWER DESERT SOUTHWEST. 00Z AND 06Z MODEL RUNS SHOW THIS LOW DIVING EVEN FARTHER SOUTH AWAY FROM COLORADO...CONSEQUENTLY HAVING LESS OF AN IMPACT ON NORTH CENTRAL AND NORTHEAST COLORADO. FOR NOW LEFT IN SCATTERED POPS IN THE MTN ZONES FOR WEDNESDAY NIGHT AND THURSDAY MORNING TO ACCOUNT FOR A WEAK SHORTWAVE SWINGING DOWN FROM WYOMING. HOWEVER DO NOT SEE THIS DISTURBANCE PRODUCING ANY PCPN ON THE PLAINS SINCE THE LOW LEVEL FLOW IS FORECAST TO REMAIN WEST-NORTHWESTERLY. CONDITIONS DRY WITH SLIGHT WARMING ON FRIDAY WITH NORTHWEST FLOW OVER THE AREA. WARMING CONTINUES ON SATURDAY WITH PASSAGE OF A WEAK SHORTWAVE RIDGE ACCORDING TO THE GFS AND ECMWF. BEYOND SATURDAY...MODELS BEGIN TO DIFFER. GFS SHOWS A DEEP TROUGH CARVING OUT OVER THE WESTERN CONUS SUNDAY INTO MONDAY...WHILE THE ECMWF HANGS ONTO NORTHWEST FLOW AT LEAST THROUGH SUNDAY NIGHT...THEN IT FORMS AN OPEN WAVE TROUGH OVER THE CENTRAL ROCKY MTN REGION AREA ON MONDAY. DUE TO THE UNCERTAINTY IN THE MODELS...WILL MAKE ONLY MINOR CHANGES TO THE FORECAST GRIDS BEYOND SATURDAY. THIS INCLUDES ADDING A BIT MORE CLOUD COVER AND RAISING POPS SLIGHTLY IN THE HIGH COUNTRY. LASTLY...SEE LITTLE DAY-TO-DAY CHANGE IN TEMPERATURE THROUGH THE EXTENDED PERIOD. AVIATION...LIGHT WINDS...LESS THAN 12 KNOTS...WILL PREVAIL THIS MORNING AND THIS AFTERNOON. EXPECT WINDS TO BECOME NORTHERLY...AROUND 21Z...BUT WIND SPEEDS WILL REMAIN LIGHT. MID AND HIGH CLOUDS WILL INCREASE AFTER 18Z AS NEXT WEATHER SYSTEM PASSES SOUTH OF COLORADO. A SLIGHT CHANCE WE COULD SEE A SHORT- LIVED SNOW SHOWER 00-09Z...ANY SNOW ACCUMULATION WILL BE VERY LIGHT. MODELS SHOWING LOW CLOUDS OVER THE EASTERN PLAINS WEDNESDAY MORNING AND THERE IS A CHANCE THEY COULD MAKE IT AS FAR WEST AS KDEN. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARJENBRUCH LONG TERM....BAKER AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1128 AM EST TUE FEB 14 2012 .SYNOPSIS... WEAK LOW PRESSURE WILL BRING A MIX OF SNOW AND RAIN SHOWERS THIS AFTERNOON INTO TONIGHT. HIGH PRESSURE WILL FOLLOW WITH A DRY WEDNESDAY. A BETTER DEVELOPED LOW PRESSURE SYSTEM, COMING NORTHEAST FROM NEW MEXICO, WILL BRING ANOTHER ROUND OF RAIN SHOWERS AND SNOW SHOWERS WEDNESDAY NIGHT AND THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... HAVE MADE SMALL ADJUSTMENTS TO WEATHER TYPE AND TEMPERATURES FOR THIS AFTERNOON AND TONIGHT, BASED ON RECENT RADAR AND SURFACE DATA, PLUS HRRR AND NAM MODEL OUTPUT. HAVE OPTED TO CHARACTERIZE THE SPOTTY INCOMING PRECIPITATION AS SHOWERY. DUE TO THE ADIABATIC STEEPNESS OF THE SURFACE LAYER TEMPERATURE LAPSE RATE, SURFACE TEMPERATURES MAY HAVE TO GET TO 35 BEFORE A CHANGE FROM SNOW TO RAIN OCCURS. HOWEVER, DUE TO THE EXPECTED LIGHTNESS OF THE PRECIPITATION AMOUNTS, ONCE GROUND TEMPERATURES REACH 33, EXPECT LITTLE IF ANY SNOW ACCUMULATION, PARTICULARLY ON PREVIOUSLY TREATED PAVEMENTS. POST SYSTEM SHOWERS WILL ALSO BE LIGHT DUE TO WEAKNESS OF SYSTEM, ALTHOUGH SNOW AMOUNTS NORTH AND MOUNTAINS MAY TOP OUT NEAR 2 INCHES FROM THE ENTIRE EVENT. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... SREF MODEL OUTPUT CONTINUES TO SHOW ENSUING HIGH PRESSURE PROVIDING A DRY BREAK WEDNESDAY INTO WEDNESDAY EVENING. THEN A SECOND LOW PRESSURE SYSTEM, MORE DEVELOPED THAN TUESDAY`S SYSTEM, WILL COME NORTHEASTWARD FROM NEW MEXICO, AND PROVIDE ANOTHER BOUT OF SHOWERS OF SNOW AND RAIN LATE WEDNESDAY NIGHT AND THURSDAY. THE ONSET OF THE PRECIP WITH THIS SYSTEM WILL BE DIFFICULT AS WELL. ALL INDICATIONS ARE THAT THERE WILL BE STRONG WAA AHEAD OF THE SFC LOW, WHICH WILL ALLOW FOR RISING TEMPS WED NIGHT. THE AREAS THAT WILL NEED TO BE CLOSELY WATCHED, WILL BE ACROSS THE FAR NORTHEAST AND GARRETT COUNTY. THIS WILL COME MORE INTO FOCUS IN LATER MODEL RUNS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AN UPPER TROUGH AND ASSOCIATED SURFACE LOW WILL MOVE NORTHEAST INTO EASTERN CANADA BY FRIDAY. SCATTERED RAIN AND SNOW SHOWERS SHOULD BEGIN TO TAPER OFF BY FRIDAY MORNING. LINGERING MOISTURE AND NORTHWEST FLOW SHOULD MAINTAIN A FEW SHOWERS OVER THE FORECAST AREA ESPECIALLY NORTH OF I-80 FRIDAY AFTERNOON. WEAK SYSTEMS PASSING TO OUR NORTH COUPLED WITH MOIST NORTHWEST FLOW WILL MAINTAIN CLOUDS AND ISOLATED SHOWERS OVER THE REGION DURING THE WEEKEND. SURFACE HIGH PRESSURE WITH DRIER AIR SHOULD PROVIDE MORE SUNSHINE ON MONDAY. TEMPERATURES ARE FORECAST TO BE A FEW DEGREES ABOVE NORMAL DURING THE EXTENDED PERIOD. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... A WEAK UPPER LEVEL DISTURBANCE WILL INITIALLY PUSH LIGHT SNOW INTO THE TERMINALS THIS MORNING. VISIBILITY RESTRICTIONS WITH SNOW WILL MOSTLY BE MVFR WITH BRIEF PERIODS OF IFR. LIGHT PRECIPITATION WILL CONTINUE INTO THE AFTERNOON, REMAINING MOSTLY SNOW NORTH OF A LINE FROM ZZV-PIT-LBE, WITH A RAIN-SNOW MIX FROM THOSE LOCATIONS SOUTH. PRECIP MAY BE MOSTLY RAIN AT LEAST DURING THE DAYTIME TUESDAY AT MGW. CEILINGS WILL LOWER TO MVFR TODAY. WINDS WILL GENERALLY REMAIN OUT OF THE SOUTH FROM 5-10KTS. A MIX OF SNOW AND RAIN SHOWERS WITH MAINLY MVFR RESTRICTIONS WILL LIKELY DIMINISH TONIGHT AS THE DISTURBANCE PUSHES EAST OF THE AREA. OUTLOOK...WEDNESDAY THROUGH SATURDAY... HIGH PRESSURE WILL RETURN VFR CONDITIONS FOR WEDNESDAY. RESTRICTIONS ARE LIKELY AGAIN THURSDAY INTO FRIDAY DUE TO A MIX OF RAIN AND SNOW SHOWERS ASSOCIATED WITH THE PASSAGE OF A STRONGER LOW PRESSURE SYSTEM TRACKING NORTHEAST FROM THE PLAINS. A MOIST NORTHWEST FLOW BEHIND THE DEPARTING LOW PRESSURE SYSTEM MAY MAINTAIN AREAS OF MVFR CEILINGS OVER THE TERMINALS SATURDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EST TUE FEB 14 2012 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 418 PM EST TUE FEB 14 2012 WV IMAGERY AND RUC ANALYSIS INDICATED AN UPSTREAM MID/UPPER LEVEL SHORTWAVE TROUGH FROM THE ERN DAKOTAS INTO SRN MN. AT THE SFC...LOW PRES WAS LOCATED OVER SE NORTH DAKOTA. SO FAR..ONLY LIGHT SNOW OR FLURRIES WERE OBSERVED WITH THE SHRTWV OVER THE DAKOTAS. AHEAD OF THE LOW WEAK SW FLOW PREVAILED WITH ABUNDANT LOW LEVEL MOISTURE FROM WI INTO UPPER MI KEEPING LOW CLOUDS OVER THE REGION. WITH THE MILD AIRMASS OVER THE AREA...TEMPS HAD CLIMBED INTO THE LOWER TO MID 30S DESPITE THE PERSISTENT CLOUD COVER. TONIGHT INTO WEDNESDAY...MODELS SUGGEST MID LEVEL FGEN ASSOCIATED WITH THE DAKOTAS SHRTWV WILL SUPPORT AREAS OF LIGHT SNOW INTO NRN WI AND UPPER MI LATE TONIGHT INTO WED MORNING. THE FCST LEANS TOWARD THE 12Z/18Z NAM WITH THE GREATER FORCING/POPS INTO THE SW HALF OF THE CWA. THERE MAY BE SOME POTENTIAL FOR A PERIOD OF BRIEF HEAVIER SNOW...GIVEN THE STRENGTH OF THE FORCING. HOWEVER...SINCE THERE STILL SOME UNCERTAINTY IN WHERE ANY STRONGER PCPN BAND MAY OCCUR...ONLY CHANCE POPS WERE INCLUDED WITH OVERALL SNOWFALL AMOUNTS OF LESS THAN AN INCH. LOOK FOR MINS TONIGHT TO RANGE MAINLY IN THE LOWER 20S OVER THE WRN INTERIOR TO THE MID 20S NEAR THE GREAT LAKES AND EAST. HIGH TEMPS WILL AGAIN CLIMB ABOVE NORMAL...INTO THE MID AND UPPER 30S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 418 PM EST TUE FEB 14 2012 STRONG NORTHERN STREAM SHORTWAVE WILL NEAR THE GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY MORNING...PHASING WITH A SOUTHERN STREAM SHORTWAVE MOVING NORTHWEST FROM THE PLAINS. PREVIOUS MODEL RUNS WERE SHOWING SOME UNCERTAINTY IN THE INTENSITY AND LOCATION OF THIS PHASING...CAUSING DISCREPANCIES IN QPF AMOUNTS AND LOCATION OF THE SURFACE LOW ASSOCIATED WITH THE SOUTHERN STREAM. MOST RECENT RUNS OF GFS/NAM/ECMWF/GEM HAVE SEEM TO COME INTO BETTER AGREEMENT...WITH GENERAL CONSENSUS HAVING THE SURFACE LOW PRESSURE PASSING OVER LOWER MI BY EARLY AFTERNOON THURSDAY. DEEPEST MOISTURE WILL BE CONFINED NEAR THE CENTER OF THE LOW...BUT GOOD CONVERGENCE AND DECENT LAPSE RATES WILL MOVE INTO UPPER MI...ESPECIALLY EAST AS THE SOUTHERN SHORTWAVE MOVES FROM SOUTHWEST TO NORTHEAST...BRINGING CHANCES FOR PRECIP BEGINNING WEDNESDAY NIGHT SOUTH CENTRAL AND REMAINING DURING THE DAY THURSDAY ACROSS THE SOUTHEAST. NORTHERN WAVE ENERGY WILL KEEP THE LOW SUPPRESSED FAR ENOUGH SOUTH THAT MOST OF THE MOISTURE AND LIFT WILL BE CONFINED TO SOUTHEAST WI AND LOWER MI WHERE THE BEST WAA IS LOCATED...THOUGH 0Z GEM BRINGS SOME OF THE ASSOCIATED HIGHER QPF VALUES FARTHER NORTH ALONG LAKE MI IN UPPER MI AS WELL. WILL KEEP WITH HIGHEST QPF AND SNOWFALL TOTALS NEAR THE LAKE MI SHORELINE...BUT GOING WITH CONSENSUS...ONLY EXPECT SNOWFALL AMOUNTS TO REACH THE 3 TO 5 INCH RANGE IN THIS AREA. SURFACE LOW PRESSURE WILL QUICKLY MOVE OFF TO THE NORTHEAST BY THURSDAY EVENING...FOLLOWED SHORTLY THEREAFTER BY THE ASSOCIATED PHASED SHORTWAVE. DRY AIR WILL THEN INFILTRATE FROM WEST TO EAST...BRINGING AN END TO PRECIP CHANCES ACROSS THE INLAND AREAS. AS THIS TAKES PLACE...WINDS WILL SHIFT TO A PREDOMINATE NW DIRECTION AND STRENGTHEN BEHIND THE SHORTWAVE. COLDER H850 TEMPERATURES WILL THEN BEGIN FILTERING IN BY THE DAY FRIDAY...ALLOWING INSTABILITY AND LES CHANCES TO DEVELOP. DAYS 4 THROUGH 7 /FRIDAY NIGHT THROUGH TUESDAY/... AS THE GENERAL TROUGH PATTERN CONTINUES OVER THE NORTHEASTERN CONUS THROUGH THE WEEKEND...EXPECT A SERIES OF SHORTWAVES TO IMPACT THE UPPER GREAT LAKES DURING THIS TIME PERIOD. MODELS WILL CONTINUE HAVING VARYING SOLUTIONS ON TIMING AND LOCATION...WITH THE ECMWF CONTINUING TO BE THE MOST PROGRESSIVE. LES CHANCES WILL CONTINUE FRIDAY NIGHT AND THEN DURING THE DAY SATURDAY WITH 0Z ECMWF H850 TEMPS -15C ACROSS LAKE SUPERIOR AND PREDOMINATE NW WINDS DURING THE DAY. LINGERING LOW LEVEL MOISTURE WILL HELP KEEP LES EAST OF MUNISING WHERE NW WINDS WILL BE MAXIMIZED WITH THE FETCH OVER THE LAKE. INVERSION HEIGHTS WILL BE AROUND 6KFT...WITH THE BEST SNOW GROWTH JUST BELOW THIS LAYER. CAPE VALUES WILL MAX OUT AROUND 18Z SATURDAY...AS WILL THE LES PARAMETER. WITH LIGHT TO MODERATE WINDS...COULD EXPECT HIGHER END SNOW RATIOS IN THE UPPER TEENS TO LOW 20S. WILL CONTINUE WITH MIDNIGHT SHIFTS DECISION TO BUMP UP POPS IN NW WIND FAVORED AREAS DURING THIS TIME PERIOD. AS NEXT SHORTWAVE PASSES OVER SATURDAY NIGHT...EXPECT WINDS TO THEN SHIFT TO A MORE WESTERLY DIRECTION AND H850 TEMPS TO BEGIN INCREASING BY SUNDAY EVENING...THEREBY BRINGING AN END TO ANY LINGERING LES CHANCES. 0Z ECMWF/GFS THEN HAVE A SHORT LIVED RIDGE BUILDING IN ON MONDAY KEEPING CONDITIONS DRY DURING THE DAY. DECREASING CLOUDS DURING THIS TIME PERIOD SHOULD ALLOW HIGH TEMPERATURES TO RISE BACK INTO THE MID 30S. AS RIDGE LIES OVER THE UPPER GREAT LAKES ON MONDAY...A SHORTWAVE WILL BEGIN DEVELOPING OVER THE PLAINS. THIS WILL AMPLIFY THE RIDGE...WHILE ALSO CAUSING ITS QUICK EXIT TO THE NORTHEAST. SHORTWAVE WILL THEN REPLACE THE RIDGE AND BRING PRECIP CHANCES BY MONDAY NIGHT...WITH THE 0Z ECMWF KEEPING THE TRACK OF THIS SHORTWAVE ACROSS WI AND LOWER MI. WITH INCREASED CLOUD COVER AHEAD OF THIS SYSTEM...DON/T EXPECT LOW TEMPERATURES TO DROP MUCH...REMAINING IN THE 20S. ASSOCIATED LOW PRESSURE WILL REACH CROSS UPPER MI BY TUESDAY AFTERNOON...WITH PRECIP CHANCES CONTINUING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1241 PM EST TUE FEB 14 2012 EXTENSIVE LOW LEVEL MOISTURE OVER UPPER MICHIGAN IS EXPECTED TO PERSIST THIS AFTERNOON INTO THIS EVENING...PER UPSTREAM OBS AND NAM/RUC 925-850 MB MOISTURE FCST. SO...MAINLY MVFR CIGS SHOULD PREVAIL. VFR CIGS EARLY THIS AFTERNOON AT KSAW ARE EXPECTED TO GIVE WAY TO MVFR CIGS FROM THE WEST BY MID AFTERNOON. ANOTHER LOW PRES SYSTEM APPROACHING FROM THE NRN PLAINS LATE TONIGHT SHOULD CONTINUE TO KEEP MVFR CIGS ACROSS THE REGION. THERE COULD BE A CHANCE OF SOME LIGHT SNOW LATE TONIGHT INTO EARLY WED. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 PM EST TUE FEB 14 2012 A SERIES OF WEAK LOW PRESSURE TROUGHS MOVING THROUGH THE AREA WILL KEEP WINDS BELOW 20KTS TONIGHT THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS ON WED NIGHT WILL MOVE THROUGH THE GREAT LAKES REGION FROM THURSDAY INTO FRIDAY. THIS WILL LEAD TO NW WINDS UP TO 25KTS OVER ERN LK SUPERIOR. HIGH PRESSURE WILL THEN MOVE OVER THE AREA FOR THE FIRST PART OF THE WEEKEND AND KEEP WINDS BELOW 20KTS. WITH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...LITTLE TO NO FREEZING SPRAY IS EXPECTED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JMW AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1243 PM EST TUE FEB 14 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 458 AM EST TUE FEB 14 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A WELL-DEFINED MID/UPPER LEVEL SHORTWAVE TROUGH MOVING ACROSS THE MID-MISSISSIPPI VALLEY EARLY THIS MORNING WITH CONFLUENT FLOW FROM NRN ONTARIO INTO THE NRN LAKES ON THE PERIPHERY OF THE DEEP TROUGH OVER ERN CANADA. LATEST RADAR IMAGERY SHOWED THAT THE NRN EDGE OF THE PCPN SHIELD WITH THIS SYSTEM HAD ADVANCED INTO SCNTRL AND ERN UPR MI WITH SFC OBS INDICATING LIGHT SNOW OR FLURRIES. AT THE SFC...A MOIST SRLY FLOW PREVAILED FROM MO/IA INTO WI AND UPPER MI AHEAD OF A TROUGH OVER THE PLAINS. IR SATELLITE REVEALED EXTENSIVE LOW TO MID CLOUD COVER ACROSS THE MIDWEST AND GREAT LAKES REGION ASSOC WITH THE SHORTWAVE. TODAY...EXPECT LIGHT SNOW OVER SCNTRL AND ERN COUNTIES TO DIMINISH OR END THROUGH THE MORNING HOURS AS SUPPORTING 700-600 MB FGEN FORCING WEAKENS AND SHIFTS EAST WITH DEPARTING SHORTWAVE. NAM/GFS BUFR SNDGS SUGGEST LOW-LVL MOISTURE AND CLOUDS WILL REMAIN THROUGH THE DAY EVEN AFTER THE SNOW ENDS. HOWEVER...MAX READINGS SHOULD STILL CLIMB INTO THE LOWER TO MID 30S...DESPITE THE LINGERING CLOUDS. TONIGHT...ANOTHER SHORTWAVE NOW OVER THE DAKOTAS IS EXPECTED MOVE EAST REACHING THE UPPER GREAT LAKES LATE TONIGHT. MODEST 285K ISENTROPIC ASCENT AND LOWERING OF CONDENSATION PRES DEFICITS ASSOC WITH THIS FEATURE COULD RESULT IN A LITTLE LIGHT SNOW OR FLURRIES LATE TONIGHT INTO WED. SINCE RADAR IS ONLY SHOWING ISOLD TO SCT COVERAGE UPSTREAM WILL ONLY INCLUDE SLIGHT CHC POPS FOR LATE TONIGHT OVER MAINLY WRN AND CENTRAL PORTIONS OF THE CWA. LOOK FOR MINS TONIGHT TO RANGE MAINLY IN THE LOWER 20S OVER THE WRN INTERIOR TO THE MID 20S NEAR THE GREAT LAKES AND EAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 458 AM EST TUE FEB 14 2012 WEAK SHORTWAVE WILL BE MOVING THROUGH THE CWA WED MORNING. WITH THE SHORTWAVE...DECENT H925-700 MOISTURE...AND H850-700 Q-VECTOR CONV THINK THERE IS A POTENTIAL FOR A FEW LIGHT SNOW SHOWERS MOVING FROM W TO E ACROSS THE CWA IN THE MORNING AND EARLY AFTN. THUS...ADDED SLIGHT CHANCES INTO THE FORECAST BUT DON/T REALLY EXPECT MUCH IF ANY ACCUM. AS THE SHORTWAVE MOVES E THROUGH THE DAY...STRONGER NRN STREAM SHORTWAVE WILL BE MOVING OUT OF THE DAKOTAS AND INTO MN. BRIEF PERIOD OF DRYING BEHIND THE DISTURBANCE COULD LEAD TO SOME BREAKS IN THE CLOUDS. THESE BREAKS WILL LARGELY DEPEND ON IF MOISTURE REMAINS TRAPPED BELOW THE 1.5-3KFT INVERSION FROM THE WAA AND DRYING ALOFT. THINK IT SHOULD STICK AROUND AND WILL KEEP SKIES MOSTLY CLOUDY. LAND AREA WILL LIKELY BE BETWEEN SYSTEMS ON WED EVENING. NRN STREAM ENERGY SHORTWAVE AND APPROACHING SFC TROUGH FROM LOW IN CNTRL CANADA WILL LEAD TO A GLANCING BLOW OVER THE NW HALF OF LK SUPERIOR. MEANWHILE...SRN STREAM ENERGY AND LOW WILL BE PUSHING OUT OF THE CNTRL PLAINS. DID START TO INCREASE POPS THROUGH THE OVERNIGHT HOURS...AS SFC TROUGH BEGINS TO SLIDE INTO THE AREA AND H850-500 Q-VECTOR CONV AND MOISTURE INCREASES. BEST CHANCES WILL BE OVER NRN LK SUPERIOR CLOSER TO THE NRN STREAM SHORTWAVE AND OVER SCNTRL UPPER MI CLOSER TO THE SFC LOW MOVING INTO THE LOWER GREAT LKS. MODEL DIFFERENCES REALLY BECOME APPARENT HEADING INTO THURSDAY...WITH NAM/GFS IN ONE CAMP AND THE ECMWF/UKMET/GEM IN THE OTHER. THIS IS NORMALLY THE CASE IN PHASING OF NRN/SRN STREAM SYSTEMS AND LEAVES LOW CONF IN THE FCST. THE NAM/GFS HAVE A MUCH STRONGER/SHARPER NRN STREAM WAVE AND THUS ENDS UP DOMINATING THE PHASING AND KEEPS THE LOW ASSOCIATED WITH THE SRN STREAM SUPPRESSED AND JUST SWEEPS THE SFC TROUGH ACROSS THE AREA. THE 00Z NAM ACTUALLY DOESN/T BRING ANY PCPN TO THE AREA...WHILE THE 00Z GFS ONLY BRINGS A FEW HUNDREDTHS. THE OTHER GROUPING HAS A WEAKER NRN STREAM AND ALLOWS SRN STREAM TO TRACK A MID 1000S SFC LOW FROM THE CNTRL PLAINS ON WED INTO THE LOWER GREAT LKS BY THURS AFTN. OVERALL CONSENSUS WITH THESE MODELS IS TO HAVE THE LOW TRACK NEAR DETROIT...ALTHOUGH THE 00Z GEM HAS SLID THE LOW FARTHER TO THE NW AND IN CNTRL LOWER MI. 21Z SREF EVEN SHOWING THESE DIFFERENCES WITH THE ENS MEAN SFC TRACKING THROUGH CNTRL LOWER MI. LOOKING AT THE INDIVIDUAL MEMBERS...THERE IS A LARGE CLUSTER OF WRF ARW/NMM MEMBERS HAVING THE LOW IN CNTRL LOWER MI...WHILE THE ETA/RSM MEMBERS KEEP IT IN THE OHIO RIVER VALLEY. HPC PREFERS THE WEAKER NRN STREAM SOLN...SO HAVE FOLLOWED THAT FOR THURS. WITH THE PREFERENCE TOWARDS THE ECMWF SOLN...EXPECT AREA OF SNOW TO QUICKLY SLIDE ACROSS THE SE HALF OF THE CWA THURS MORN AND INTO EARLY AFTN. DECENT H850-700 Q-VECTOR CONV AND MOISTURE OVER THE AREA...BUT THE BETTER WAA STAYS SE OF THE AREA AND CLOSER TO THE LOW. DEPENDING ON THE EXACT TRACK OF THE LOW...SNOW AMNTS WILL FLUCTUATE TO THE NW OR SE BUT CURRENTLY HAVE 1-3IN ALONG THE LK MI SHORELINE. ALSO ADJUSTED THE EXISTING LIKELYS OVER PORTIONS OF THE ERN CWA TO LINE UP ALONG THE LK MI SHORELINE AND JUST HAVE CHANCES ELSEWHERE. WITH THE LOW CONF ON OCCURRENCE AND SUB ADVY VALUES...WILL LEAVE MENTION OUT OF THE HWO. AS THE ENERGY SLIDES ENE DURING THE AFTN...SHOULD SEE A DIMINISHING TREND FROM W TO E IN THE PCPN. COLDER AIR WILL START TO FILTER IN BEHIND THE LOW/TROUGH AND COULD LEAD TO SOME LK EFFECT PCPN AS H850 TEMPS FALL TOWARDS -10C BY 00Z FRI. LINGERED SOME CHANCES OVER THE FAR WRN CWA TO ACCOUNT FOR THIS. H850 TEMPS WILL GRADUALLY FALL TOWARDS -12C THURS NIGHT. WITH WNW WINDS...HAVE CHANCE LES POPS IN AREAS FAVORED BY THAT WIND DIRECTION. BUFKIT SOUNDINGS SHOWING WELL MIXED LLVLS WHICH SHOULD LIMIT INTENSITY OF THE BANDS. DAYS 4 THROUGH 7 /FRIDAY THROUGH MONDAY/... NEXT SHORTWAVE MOVING AROUND THE UPPER LOW STATIONED OVER ERN CANADA WILL IMPACT THE AREA ON FRI. STILL DECENT DIFFERENCES IN THE INTENSITY/LOCATION OF THE WAVE...BUT IT SHOULD PULL ADDITIONAL MOISTURE INTO THE AREA AND PROVIDE AN UPTICK IN THE ONGOING LES. NOT A WHOLE LOT OF AGREEMENT HEADING THE REST OF THE WAY THROUGH THE EXTENDED FORECAST PERIOD...AS EXTENDED MODELS CONTINUE TO STRUGGLE WITH THE NRN/SRN STREAMS COMING TOGETHER OVER THE NEW ENGLAND STATES. LIKELY WILL SEE NW FLOW ALOFT AND THE POTENTIAL FOR SHORTWAVES TO MOVE ACROSS THE AREA. CONTINUED LES CHANCES FOR NW WINDS FAVORED LOCATIONS FRI NIGHT INTO SAT NIGHT. H850 TEMPS PEAK AROUND -15C ON FRI NIGHT INTO SAT MORNING AND THEN GRADUALLY WARM THROUGH THE REST OF THE WEEKEND. WITH DECENT LLVL MOISTURE AT THAT TIME AND INVERSION HEIGHTS AROUND 5KFT...EXPECT LIGHT TO MODERATE LES TO CONTINUE FOR NW WIND FAVORED LOCATIONS. MUCH OF THE LES CLOUD SHOULD BE WITHIN THE DGZ...SO THE POTENTIAL EXISTS FOR NEAR ADVY CRITERIA SNOW AMNTS FRI NIGHT INTO SAT. BEST CHANCE WOULD BE E OF MUNISING WHERE THE LONGER FETCH WILL AID INTENSITY. HAVE BUMPED POPS UP SIGNIFICANTLY IN THAT AREA TO HIGH END CHANCES. AS H850 TEMPS SLOWLY WARM AND DRIER AIR STARTS TO ARRIVE...TAPERED POPS DOWN SAT NIGHT INTO SUN. H850 RIDGE WILL LIKELY MOVE OVER THE CWA HEADING INTO MON...BRINGING WARMER H850 TEMPS AND DRIER AIR. OVERALL TEMPS LOOK TO REMAIN NORMAL TO ABOVE NORMAL THROUGH THE FIRST PART OF NEXT WEEK WITH NO MAJOR SNOW EVENTS ON THE HORIZON. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1241 PM EST TUE FEB 14 2012 EXTENSIVE LOW LEVEL MOISTURE OVER UPPER MICHIGAN IS EXPECTED TO PERSIST THIS AFTERNOON INTO THIS EVENING...PER UPSTREAM OBS AND NAM/RUC 925-850 MB MOISTURE FCST. SO...MAINLY MVFR CIGS SHOULD PREVAIL. VFR CIGS EARLY THIS AFTERNOON AT KSAW ARE EXPECTED TO GIVE WAY TO MVFR CIGS FROM THE WEST BY MID AFTERNOON. ANOTHER LOW PRES SYSTEM APPROACHING FROM THE NRN PLAINS LATE TONIGHT SHOULD CONTINUE TO KEEP MVFR CIGS ACROSS THE REGION. THERE COULD BE A CHANCE OF SOME LIGHT SNOW LATE TONIGHT INTO EARLY WED. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 458 AM EST TUE FEB 14 2012 A SERIES OF WEAK LOW PRESSURE TROUGHS MOVING THROUGH THE AREA WILL KEEP WINDS BELOW 20KTS TODAY THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS ON WED NIGHT WILL MOVE THROUGH THE GREAT LAKES REGION FROM THURSDAY INTO FRIDAY. THIS WILL LEAD TO NW WINDS UP TO 25KTS OVER ERN LK SUPERIOR. HIGH PRESSURE WILL THEN MOVE OVER THE AREA FOR THE FIRST PART OF THE WEEKEND AND KEEP WINDS BELOW 20KTS. WITH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...LITTLE TO NO FREEZING SPRAY IS EXPECTED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...JLB MARINE...VOSS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
341 PM MST TUE FEB 14 2012 .SHORT TERM...VALID FOR WED AND THU... A SHORT WAVE TROUGH CONTINUES MOVING EAST-SOUTHEAST ACROSS MT THIS AFTERNOON...AND RUC OBJECTIVE ANALYSES SUGGEST THE 1.5 PVU SURFACE ASSOCIATED WITH THIS FEATURE HAS LOWERED TO 500 HPA. PRECIPITATION ASSOCIATED WITH THIS WAVE WILL BE THE MAIN FORECAST ISSUE OVER THE NEXT 6 TO 12 HOURS...BUT THEN OUR CHALLENGE WILL MAINLY TRANSITION TO ONE OF TEMPERATURES. WE SET THE 12 UTC NAM SOLUTION ASIDE WHILE DEVELOPING THE SHORT TERM FORECAST SINCE IT IS AN OUTLIER COMPARED TO THE REST OF THE GUIDANCE IN HOW IT HANDLES SOME KEY FEATURES IN SPLIT FLOW OVER THE CONUS AND A NORTHWEST 500-HPA PATTERN OVER MT. WE WILL MAINTAIN SOME 40 TO 60 PERCENT POPS ACROSS SOUTHEASTERN MT AND SHERIDAN COUNTY WY THROUGH THE EVENING GIVEN FAIRLY WIDESPREAD SNOW SHOWER ACTIVITY AHEAD OF THE 500-HPA SHORT WAVE. RADAR IMAGES SUGGEST THIS PRECIPITATION IS LIKELY BEING ENHANCED A BIT IN AREAS LIKE SOUTHERN BIG HORN COUNTY WHERE LOW-LEVEL UPSLOPE FLOW EXISTS. IN GENERAL THOUGH...WE WILL SIMPLY TIME THE FORCING CONCOMITANT TO THE WAVE EAST...WITH ONLY A LOW CHANCE OF SNOW SHOWERS IN ITS WAKE FOR THE EVENING WHERE LOW-LEVEL INSTABILITY LINGERS IN PLACES LIKE BILLINGS. THE MULTI-MODEL CONSENSUS SUGGESTS WE WILL MAINLY HAVE A DRY FORECAST IN PLACE AFTER 06 UTC...WITH ONLY SOME LOW POPS STILL NEEDED OVER FAR SOUTHEASTERN MT AND IN THE MOUNTAINS. WE WILL ALSO HAVE LOW POPS OVER THE MOUNTAINS ON WED AND THU WITH THE NORTHWEST FLOW ALOFT. ON WED...FORECAST SOUNDINGS SUGGEST MIXING UP TO 800 HPA OVER MOST OF THE PLAINS...WHICH YIELDS HIGHS CLOSE TO 40 F. WE USED THE MIX- DOWN NUMBERS BASED ON GFS THERMAL PROFILES TO DERIVE OUR HIGHS. IN THIS PATTERN WITH LOW-LEVEL WEST-NORTHWEST DOWNSLOPE FLOW AND LACK OF SNOW COVER ON THE PLAINS...MOS-BASED NUMBERS WILL LIKELY END UP BEING TOO COLD. CYCLONIC FLOW LINGERS ALOFT AND FORECAST SOUNDINGS SHOW SOME MID-LEVEL SATURATION AS CONVECTIVE THERMALS GET GOING IN THE 18 TO 00 UTC TIME FRAME...SO SOME DIURNALLY-DRIVEN SHOWERS MAY OCCUR...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE THE CHANCE IN THE FORECAST AT THIS POINT. FOR THU...WARMER MID-LEVEL TEMPERATURES LOOK TO BE IN PLACE...WITH DOWNSLOPE LOW-LEVEL FLOW PERHAPS ACCENTUATED THANKS TO THE PASSAGE OF A WEAK WAVE TO OUR NORTH. WE CAUTIOUSLY MIXED DOWN TEMPERATURES FROM 850 OR 800 HPA USING 12 UTC GFS AND ECMWF GUIDANCE /WHICH ARE SHOWING 850-HPA TEMPERATURES OF +1 TO +3 C/ TO CALL FOR HIGHS WELL INTO THE 40S F. THIS DOES PUT OUR FORECAST ON THE WARM SIDE OF THE GUIDANCE ENVELOPE...BUT THIS IS WHERE WE WANT TO BE IN A SITUATION LIKE THIS...WHICH REALISTICALLY COULD HAVE SOME 50 F READINGS WITH EFFICIENT MIXING. SCHULTZ .LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE... DIRTY NORTHWEST FLOW ON FRIDAY WILL TRANSITION TO WESTERLY FLOW SATURDAY AHEAD OF WHAT IS BECOMING A STRONGER SYSTEM FOR SATURDAY NIGHT INTO SUNDAY. KEPT MENTION OF SLIGHT CHANCE POPS ON FRIDAY WITH NORTHWEST FLOW OVER THE AREA. SATURDAY LOOKS MAINLY DRY WITH DOWNSLOPE WINDS BOOSTING TEMPERATURES POSSIBLY INTO THE LOWER 50S SATURDAY AFTERNOON. COLD FRONT AND PRECIPITATION SHOULD MOVE INTO THE AREA FROM THE WEST SATURDAY EVENING...WITH TROF OVERHEAD INTO MONDAY. BEST CHANCES FOR PRECIPITATION WILL BE SATURDAY NIGHT INTO SUNDAY...WITH LOW POPS LINGERING INTO MONDAY UNDERNEATH THE TROF. TEMPERATURES SUNDAY AND MONDAY LOOK TO REMAIN MAINLY IN THE 30S. HEIGHT RISES ADVECT IN FROM THE WEST ON TUESDAY FOR WARMER DOWNSLOPE PATTERN. MODELS ARE IN PRETTY GOOD AGREEMENT WITH MOST PARAMETERS THROUGH SATURDAY NIGHT...HOWEVER THE LATEST ECMWF MOVES THE SYSTEM OUT OF THE AREA FASTER RESULTING IN DRIER CONDITIONS SUNDAY NIGHT AND MONDAY. CURRENTLY TRENDING A BIT TOWARD THE GFS FOR CONTINUITY. CHAMBERS && .AVIATION... RAIN AND SNOW SHOWERS WILL CONTINUE THIS EVENING MAINLY EAST OF BILLINGS. PERIODS OF HEAVIER SNOW SHOWERS IN THE KSHR AND KMLS AREAS MAY TEMPORARILY LIMIT FLIGHT CONDITIONS TO IFR/LIFR/VLIFR...WITH IFR CONDITIONS PREVAILING. GUSTY WINDS ARE EXPECTED ACROSS MUCH OF THE AREA THROUGH EARLY THIS EVENING...MAINLY FROM KBIL WEST. MOUNTAIN OBSCURATIONS ARE EXPECTED THROUGH THIS EVENING...MAINLY IN THE BIG HORN AND BEARTOOTH MOUNTAINS. OTHERWISE...CONDITIONS WILL CONTINUE TO IMPROVE FROM WEST TO EAST OVERNIGHT. CHURCH && .PRELIMINARY POINT TEMP/POPS... WED THU FRI SAT SUN MON TUE ----------------------------------------------------------- BIL 017/041 022/046 030/043 024/047 025/036 020/036 020/042 21/B 00/B 12/W 11/B 53/J 12/J 21/B LVM 013/035 018/042 023/042 021/046 022/030 015/031 017/039 11/B 00/N 12/J 12/W 53/J 22/J 21/B HDN 021/041 020/048 029/044 022/048 022/037 017/037 017/042 31/B 00/B 12/W 11/B 43/J 12/J 21/B MLS 018/040 021/046 026/041 022/046 024/038 020/037 018/041 41/B 00/B 11/B 11/B 23/J 12/J 21/B 4BQ 019/038 020/044 026/040 022/045 024/035 017/035 016/039 50/B 00/B 12/J 11/U 24/J 32/J 22/J BHK 017/037 019/043 023/038 020/042 024/036 017/035 015/037 51/B 00/B 01/B 11/U 13/J 22/J 21/B SHR 013/037 017/043 024/040 019/044 020/031 013/034 013/038 61/B 11/B 12/J 21/U 34/J 22/J 21/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
933 AM MST TUE FEB 14 2012 .SHORT TERM...VALID FOR TDY AND WED... A VIGOROUS SHORT WAVE TROUGH WITH ITS AXIS FROM GREAT FALLS TOWARD BOZEMAN AS OF 16 UTC WILL SWEEP EAST-SOUTHEAST ACROSS MT TODAY. IT LOOKS LIKE QUITE A BIT IN THE WAY OF DYNAMICS WILL BE ACCOMPANYING THIS FEATURE...WITH THE 1.5 PVU SURFACE LOWERING TO AROUND 520 HPA BY 00 UTC. HOWEVER...Q-VECTOR CONVERGENCE IS NOT VERY POTENT...AND THE FAST MOVEMENT OF THE WAVE IS NOT ESPECIALLY FAVORABLE FOR LOTS OF MOISTURE. NONETHELESS...GIVEN STEEP MID-LEVEL LAPSE RATES ALONG WITH UPSTREAM TRENDS...WE DID INCREASE POPS INTO THE 40-50 PERCENT RANGE FROM ROUNDUP SOUTHEAST TO MILES CITY AND BAKER DURING THE 18 TO 00 UTC TIME FRAME...AND LINGERING PAST 00 UTC AROUND BAKER. THE GFS ENSEMBLE MEMBERS FROM 00 UTC STILL MAKE A GOOD CASE FOR QPF IN SOUTHEASTERN MT THIS AFTERNOON AND EVENING TOO. SNOW IS ALSO GOING AS OF 16 UTC IN THE FOOTHILLS AND AROUND JUDITH GAP...SO POPS OVER THOSE AREAS WILL REMAIN IN THE 70 TO 90 PERCENT RANGE TODAY. THERE IS STILL LITTLE SUGGESTION IN GUIDANCE OR TRENDS FOR ANYTHING MORE THAN ABOUT AN INCH OR TWO OF SNOW IN THE LOWER ELEVATIONS WITH THE WAVE...BUT WE WILL CONTINUE TO MONITOR FOR THAT POSSIBILITY. ONLY MINOR CHANGES WERE MADE TO THE REST OF THE FORECAST WITH THIS UPDATE...MAINLY TO INCREASE HIGHS EVER-SO-SLIGHTLY IN PLACES GIVEN THE WARM START...AND TO SOMEWHAT AMBITIOUSLY ADVERTISE A PERIOD OF 20 TO 30 MPH WINDS DURING THE AFTERNOON OVER SOUTH CENTRAL MT. THE WINDS ARE PREDICATED ON THE POSSIBILITY OF SUBSIDENCE HELPING PUSH WINDS TO THE SURFACE IN THE WAKE OF THE STOUT 1.5 PVU LOWERING. WE ALSO NOTED THAT RUC SOUNDINGS AT BILLINGS HAVE 35 KT WINDS AT THE TOP OF THE MIXED LAYER FROM 21 TO 00 UTC. SCHULTZ .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... MADE BROADER CHANGES TO THE LATER PERIODS OF THE EXTENDED FORECAST AS MODELS ARE HINTING AT BETTER CHANCES FOR TROUGHINESS TO INFLUENCE THE WEATHER FOR SUNDAY AND BEYOND. THURSDAY LOOKS A BIT DOWNSLOPISH WHICH SHOULD KEEP THE PLAINS DRY AS MOISTURE CONTINUES TO TRIGGER OROGRAPHIC SHOWERS IN THE MOUNTAINS. NOT A REAL STRONG DOWNSLOPE SO NOT EXPECTING MUCH OF A WARMUP. FRIDAY AN UPPER LEVEL RIDGE BUILDS INTO THE PACIFIC NORTHWEST BRINGING A BIT OF WARM AIR ADVECTION ALOFT. THIS WILL BE LINING UP WITH A SHOT OF COOLER AIR WHICH SLIDES INTO THE EASTERN END OF THE STATE. IF THE COLD AIR PUSHES FAR ENOUGH WEST AN OVERRUNNING PATTERN COULD BE SETUP ESPECIALLY IF SOME UPSLOPE CAN BE ESTABLISHED ALONG THE FOOTHILLS. PATTERN DOES LOOK WEAK BUT WILL HAVE TO WATCH FOR THIS LINING UP A BIT BETTER IF THE UPPER FLOW PATTERN CAN BE MORE AMPLIFIED THAN CURRENTLY PROGGED. RIDGE CROSSES THE AREA ON SATURDAY WHICH SHOULD BRING A DRY AND STABLE PERIOD. THIS SHOULD BRING THE BEST CHANCE OF HAVING TEMPERATURES REACH THE MID 40S. NEXT SYSTEM MOVES INTO THE REGION BEHIND THE RIDGE AND TAKES ITS TIME MOVING THROUGH MONTANA AND WYOMING. EXACT DETAILS MAKE IT DIFFICULT TO SEE WHEN THE BEST CHANCE FOR PRECIPITATION WILL BE DURING THE SUNDAY THROUGH TUESDAY TIME FRAME BUT IT DOES LOOK LIKE UNSETTLED AND COOLER SHOULD REIGN. HAVE GONE WITH BETTER CHANCES FOR PRECIPITATION IN THE LOWER ELEVATIONS DURING THIS PERIOD AND COOLED TEMPERATURES A BIT. ECMWF DOES TAKE THE UPPER LOW NORTH OF THE AREA WHICH WOULD BE A DRIER PATTERN SO NOTHING MORE THAN ISOLATED POPS HAVE BEEN ADDED. BORSUM && .AVIATION... DISTURBANCE MOVING ACROSS THE AREA TODAY WILL BRING RAIN AND SNOW SHOWERS. THIS WILL BRING A CHANCE OF MVFR CONDITIONS WITH THE STRONGER SHOWERS THIS AFTERNOON FOR KBIL...KMLS AND KSHR. GUSTY WINDS ARE EXPECTED TO DEVELOP ACROSS THE PLAINS FROM KLVM TO KBIL THIS AFTERNOON...BEFORE DIMINISHING THIS EVENING. EXPECT DECREASING CLOUDS FROM WEST TO EAST TONIGHT. CHURCH && .PRELIMINARY POINT TEMP/POPS... TDY WED THU FRI SAT SUN MON ------------------------------------------------------- BIL 040 017/038 022/040 025/041 024/045 022/038 021/038 3/J 21/B 00/B 12/W 11/B 02/J 22/J LVM 036 014/035 018/039 021/038 022/042 022/035 019/035 5/J 21/B 00/B 12/W 11/B 12/J 12/J HDN 040 021/039 020/040 020/041 021/045 020/040 018/040 4/W 21/B 00/B 12/W 11/B 01/B 22/J MLS 037 017/037 021/039 021/039 021/043 021/038 020/038 5/J 31/B 01/B 11/B 11/B 11/B 22/J 4BQ 039 019/035 020/037 020/040 020/044 020/039 019/039 4/J 32/J 00/B 12/W 11/U 01/B 22/J BHK 035 016/036 019/037 017/038 018/040 018/037 016/035 4/J 41/B 00/B 01/B 11/U 01/B 12/J SHR 039 016/036 017/038 018/040 018/043 019/038 016/038 5/J 61/B 11/B 12/W 21/U 12/J 22/J && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
416 PM CST TUE FEB 14 2012 .DISCUSSION...18Z GUIDANCE AND LATEST HRRR INDICATE LIGHT PRECIP WILL BE POSSIBLE THIS EVENING AND WITH AREA OBS AND KCRP RADAR INDICATING PRECIP ALREADY OCCURRING...HAVE ADDED MENTION OF PATCHY DRIZZLE AND ISOLATED SHOWERS FOR THE EVENING HOURS. ALSO ADJUSTED HOURLY TEMPERATURE AND HUMIDITY FORECAST FOR THIS EVENING DUE TO TODAY/S MAX TEMPS BEING SIGNIFICANTLY LOWER THAN PREVIOUSLY EXPECTED. UPDATED PRODUCTS TO BE SENT SHORTLY. NO CHANGES TO FORECAST MADE BEYOND MIDNIGHT TONIGHT WITH THIS UPDATE. && .PREV DISCUSSION... /ISSUED 304 PM CST TUE FEB 14 2012/ SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...LOW LEVEL JET WILL INCREASE TO 30-35KTS TONIGHT WHICH WILL USHER DEEPER LOW LEVEL MOISTURE INTO S TX. MOS GUIDANCE AND FCST SOUNDINGS ALL SHOW FOG...POSSIBLY DENSE...TONIGHT/WED MORNING. HOWEVER...GIVEN THE STRENGTHENING LOW LEVEL JET AND ELEVATED SFC WINDS...THERE IS SOME UNCERTAINTY AS TO HOW LOW VISIBILITIES WILL DROP. HAVE INTRODUCED A MENTION OF AREAS OF FOG BUT NO MENTION OF DENSE. PRECIP CHCS WILL BE ON THE INCREASE BY WED MORNING AS AN UPPER LOW TRACKS TOWARD THE TX PANHANDLE WITH EMBEDDED ENERGY/STRONG UPPER JET MOVING ACROSS TX. A COLD FRONT IS PROGD TO MOVE INTO THE W CWA LATE MORNING OR EARLY AFTERNOON...TRACKING E TO SE AND REACHING THE COAST LATE AFTERNOON/EARLY EVENING. THE FRONTAL BDRY WILL PROVIDE LOW LEVEL MOISTURE CONVERGENCE...ESPECIALLY ACROSS THE NE CWA. BEST CHC OF SHRA`S/TSRA`S WILL BE ACROSS THE NE CWA DUE TO THE PROXIMITY OF THE UPPER JET...HIGHEST CAPE...LOWEST CIN...DEEPEST MOISTURE. ALTHOUGH THE UPPER JET WILL PROVIDE UPPER LEVEL SUPPORT FOR TSRA`S...THE JET CORE/BEST ENERGY WILL BE MUCH FARTHER N...THEREFORE AM NOT EXPECTING SEVERE TSRA`S AT THIS TIME. A FEW MAY BECOME STRONG ACROSS THE NE CWA DUE TO A BRIEF WINDOW WHERE CAPE...HELICITY AND LIFT WILL BE IN PLACE. HAVE SHOWN A TREND WITH THE POPS DECREASING ACROSS THE W AND INCREASING ACROSS THE COASTAL WATERS AS THE UPPER SYSTEM MOVES E AND THE FRONTAL BDRY MOVES OFFSHORE. DRIER AND COOLER CONDITIONS WILL FILTER INTO S TX WED NIGHT BEHIND THE FRONT. MARINE...PATCHY SEA FOG CAN BE EXPECTED TONIGHT AS DEWPOINTS INCREASE ACROSS RELATIVELY COOLER WATER. THIS IS DUE TO INCREASING SLY WINDS DVLPG TONIGHT TO MOD LEVELS...MAINLY ACROSS THE OFFSHORE WATERS. WINDS WILL RELAX THROUGH WED AFTERNOON AS A COLD FRONT MOVES INTO S TX. THE CHANCE FOR SHRA`S AND TSRA`S WILL INCREASE WED AFTERNOON INTO EARLY WED EVENING AHD OF THE COLD FRONT WITH RAIN CHCS DECREASING WED NIGHT AS THE COLD FRONT PUSHES S AND E OF THE AREA. A WEAK TO MODERATE OFFSHORE FLOW CAN BE EXPECTED LATE WED NIGHT/EARLY THU MORNING. LONG TERM (THURSDAY THROUGH TUESDAY)...MAIN FORECAST CHALLENGE IS DETERMINE RAIN CHANCES...IF AND WHEN. COLD FRONT IS COMING DOWN ON THURSDAY...AND MODELS ARE DRYING OUT THE LOWER AND MID LEVELS. THUS...THINK ANY QPF THAT MODELS ARE GENERATING ARE OVER-DONE. HOWEVER...BETTER MID LEVEL MOISTURE DOES RETURN LATE THURSDAY NIGHT SO WILL INCLUDE A SLIGHT CHANCE FOR LIGHT RAIN AFTER MIDNIGHT ON THURSDAY NIGHT. ISENTROPIC UPGLIDE FRIDAY PROVIDES A CHANCE FOR SOME LIGHT RAIN...THEN APPROACH OF UPPER TROUGH FRIDAY NIGHT PROVIDES A GOOD CHANCE FOR RAIN AND POSSIBLE ELEVATED THUNDERSTORMS INTO SATURDAY MORNING. GFS IS NOW A BIT FASTER THAN ECMWF.. UKMET...AND CANADIAN. THE GFS TIMING/MOVEMENT WOULD MEAN LOWER POPS WEST SATURDAY MORNING. DUE TO SLIGHT MODEL CHANGES FROM RUN TO RUN...GENERALLY HAVE KEPT SIMILAR POPS IN FOR SATURDAY MORNING OUT EAST AS HAVE ON FRIDAY LATE NIGHT...BUT DECREASED THEM A BIT TO THE WEST FROM FRIDAY NIGHTS POPS. FRONT COMES DOWN ON SATURDAY AS SURFACE LOW/COASTAL TROUGH MOVES EAST...WITH DRY CONDITIONS EXPECTED FOR THE REMAINDER OF THE FORECAST. SINCE RETURN FLOW RESUMES BY MONDAY...COULD NOT RULE OUT SOME CONVECTION LATE MONDAY NIGHT/TUESDAY AS NEXT SYSTEM APPROACHES FROM WEST. HOWEVER...THE IMPACTS FROM THIS SYSTEM IMPACTS MAY BE A BIT TOO FAR NORTH FOR ANY NOTABLE RAIN CHANCES SO LEFT OFF (MODELS HAVE BEEN FLIP-FLOPPING ON THAT TOO). SUMMARY FOR TEMPERATURES...GENERALLY ON THE COOL SIDE THURSDAY AND ESPECIALLY FRIDAY (ISENTROPIC LIFT/RAIN-COOLED AIR)...CONTINUES ON SATURDAY BEHIND FRONT. GRADUAL WARM UP BY EARLY NEXT WEEK WITH THE RETURN FLOW. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 65 80 57 69 53 / 20 30 10 10 20 VICTORIA 64 77 53 66 48 / 20 50 20 10 10 LAREDO 62 85 57 71 53 / 10 10 10 10 20 ALICE 65 81 55 69 51 / 20 30 10 10 20 ROCKPORT 65 77 57 66 50 / 20 40 20 10 20 COTULLA 60 80 52 68 48 / 10 20 10 10 10 KINGSVILLE 65 81 57 69 50 / 20 20 10 10 20 NAVY CORPUS 66 76 58 68 55 / 20 30 10 10 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ UPDATE...HART/79
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1133 AM CST TUE FEB 14 2012 .SHORT TERM...TODAY THROUGH THURSDAY 353 AM CST TUE FEB 14 2012 AT 3 AM...KARX RADAR SHOWED A DEFORMATION BAND OF LIGHT SNOW MOVING EAST ACROSS THE FORECAST AREA. THE WESTERN EDGE WAS LOCATED FROM MONDOVI WISCONSIN TO CHARLES CITY IOWA. THE LATEST RUC SHOWS THAT THE 800-700 MB FRONTOGENESIS ASSOCIATED WITH THIS BAND WILL CONTINUE TO MOVE EAST THIS MORNING AND GRADUALLY WEAKEN. AT THE SAME TIME...THE SOUNDINGS SHOW THAT THE MOISTURE BELOW 850 MB WILL GRADUALLY DRY. EVEN THOUGH IT IS DRYING OUT...THERE CONTINUES TO BE SOME ICE CRYSTALS SEEDING FROM ALOFT TO KEEP THE PRECIPITATION IN THE FORM OF SNOW. DUE TO THIS JUST WENT WITH SOME FLURRIES THIS MORNING. FOR TONIGHT...THE 14.00Z MODELS SUGGEST THAT A PV ANOMALY WILL MOVE EAST THROUGH CENTRAL MINNESOTA AND NORTHERN WISCONSIN. MODEL SOUNDINGS SHOW SOME MOISTURE BETWEEN 925 AND 700 MB. IN THIS SAME LAYER...THERE IS ENOUGH LIFT FOR A BRIEF PERIOD OF LIGHT SNOW ACROSS NORTH CENTRAL WISCONSIN. THE NAM/WRF...GFS...AND GEM GENERATE SOME LIGHT PRECIPITATION ACROSS THIS AREA. DUE TO THIS...ADDED A SLIGHT CHANCE TO THE FORECAST FOR TONIGHT. FROM WEDNESDAY AFTERNOON THROUGH THURSDAY...THE 14.00Z GFS...ECMWF... AND NAM/WRF ARE IN GOOD AGREEMENT THAT A SURFACE LOW WILL TRACK FROM SOUTHWEST MISSOURI NORTHEAST TO SOUTHERN ONTARIO. THIS TRACK IS VERY SIMILAR TO THE 13.12Z MODELS. THE ONE EXCEPTION TO THIS WAS THE GEM WHICH SHOWS THE LOW MOVING FROM KANSAS CITY NORTHEAST TO CHICAGO ILLINOIS. LOOKING AT ITS ENSEMBLE FAMILY...ONLY 3 OF ITS 16 MEMBERS SUPPORT THIS MORE NORTHERN TRACK...AND IN MANY CASES THERE IS NO PRECIPITATION AT ALL IN OUR FORECAST AREA. THE REASON FOR THE MORE SOUTHERN TRACK THAN THE 13.00Z IS HOW THE NORTHERN STREAM SYSTEM MOVING THROUGH SOUTHERN CANADA INTERACTS WITH THE SOUTHERN STREAM SYSTEM MOVING THROUGH THE CENTRAL PLAINS AND MID MISSISSIPPI RIVER VALLEY. THE NORTHERN STREAM IS SYSTEM LESS AMPLIFIED IN ITS LATEST RUNS /WITH THE EXCEPTION OF THE GEM/...AND THIS RESULT IN THE SOUTHERN LOW NOT BEING DRAWN NORTHWARD INTO OUR AREA. DUE TO THIS...TRENDED BOTH WEDNESDAY AFTERNOON AND THURSDAY DRIER. IF THIS TREND CONTINUES...WILL LIKELY HAVE TO GO DRY FOR BOTH OF THESE PERIOD. FOR WEDNESDAY NIGHT...THE PRECIPITATION CHANCES WERE TRENDED FURTHER SOUTHEAST. AT THIS TIME...IT LOOKS LIKE THE ONLY MEASURABLE SNOW WILL BE ACROSS SOUTHWEST WISCONSIN. .LONG TERM...THURSDAY NIGHT THROUGH WASHINGTONS BIRTHDAY 342 AM CST TUE FEB 14 2012 ON WASHINGTONS BIRTHDAY...THE 14.00Z CONTINUES TO SHOW THAT CYCLOGENESIS WILL DEVELOP ACROSS THE DAKOTAS AND THEN MOVE EAST THROUGH THE FORECAST AREA. LIKE THE PAST COUPLE OF DAYS...THE PRECIPITATION TYPE FORECAST IS GREATLY COMPLICATED BY DIFFERENCES IN THE BOUNDARY LAYER TEMPERATURES. FOR THE TIME BEING...JUST WENT WITH A MENTION OF RAIN AND SNOW WITH THIS SYSTEM. && .AVIATION...THIS AFTERNOON THROUGH WEDNESDAY 1133 AM CST TUE FEB 14 2012 CONFIDENCE ON THE LOW SIDE...AS DETAILS OF MOISTURE/STRATUS TRAPPED UNDER A SHALLOW BUT STRONG INVERSION THIS TIME OF YEAR INHERENTLY DIFFICULT. IFR TO MVFR STRATUS OVER THE TAF SITES PROBLEMATIC THRU THIS AFTERNOON/INTO THIS EVENING AS PLENTIFUL MOISTURE REMAINS TRAPPED UNDER AN INVERSION NEAR 900MB. SFC OBS/SATELLITE IMAGERY INDICATE SLOW CLEARING FROM THE WEST THRU THIS MORNING AND DID TREND KRST TOWARD A BREAKUP OF THE STRATUS DECK DURING THE MID AFTERNOON. BREAKUP OF THE MVFR STRATUS NOT LIKELY TO REACH KLSE UNTIL AT LEAST THIS EVENING. NEXT SHORTWAVE WILL SPREAD SOME BKN080-100 CLOUDS ACROSS THE TAF SITES THRU THIS EVENING...WITH THESE CLOUDS BECOMING SCT FOR THE LATE EVENING/OVERNIGHT ONCE THE WAVE PASSES. YET ANOTHER SHORTWAVE WILL SPREAD ANOTHER ROUND OF MAINLY BKN070-100 CLOUDS ACROSS THE TAF SITES FOR WED. FOR VSBYS...THE STRONG INVERSION NEAR 900MB WILL REMAIN IN PLACE THRU TONIGHT/WED AND LOWER A BIT TOWARD 925- 950MB. THIS WILL CONTINUE TO TRAP ABUNDANT BOUNDARY LAYER MOISTURE OVER THE AREA. VSBYS WILL CONTINUE TO IMPROVE THIS AFTERNOON...BUT WITH LIGHT SOUTHWEST/SOUTH WINDS TONIGHT/EARLY WED AND A DECREASE OF CLOUDS TONIGHT...MVFR VSBYS WITH LCL IFR VSBYS IN BR EXPECTED TO PREVAIL LATER THIS EVENING THRU AT LEAST MID MORNING WED. && .ARX WATCHES/WARNINGS/ADVISORIES... 342 AM CST TUE FEB 14 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM....BOYNE AVIATION.....RRS