Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/02/13


AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
204 AM MST THU JAN 31 2013 .UPDATE... ISSUED AT 201 AM MST THU JAN 31 2013 AS OF 2 AM...RADAR AND WEBCAMS CONTINUE TO SHOW SNOW BANDS PERSISTING OVER GLENWOOD SPRINGS AND THROUGH GLENWOOD CANYON. LATEST HRRR AND RAP SHOW SNOW CONTINUING THROUGH 15Z WITH SNOW RAPIDLY DROPPING OFF AFTERWARDS. THIS CORRESPONDS WELL WITH TIME HEIGHTS OVER GLENWOOD CANYON SHOWING DEEP SATURATED LAYER IN THE DENDRITIC GROWTH ZONE WITH DECENT UPWARD MOTION PERSISTING THROUGH 15Z BEFORE THE PROFILE DRIES OUT. THEREFORE...EXTENDED THE WINTER WEATHER ADVISORY FOR COZ008 THROUGH 15Z THIS MORNING. UPDATE ISSUED AT 1130 PM MST WED JAN 30 2013 BASED ON RADAR AND SATELLITE OBSERVATIONS...THE PERSISTENT SNOW BANDS THAT BROUGHT SNOW TO THE I-70 CORRIDOR HAVE SHIFTED EASTWARD WITH CONDITIONS IMPROVING FROM RIFLE TO SILT BASED ON OBSERVATIONS AND WEBCAMS. THIS IS CONSISTENT WITH THE LATEST RAP DATA SHOWING LITTLE IF ANY ADDITIONAL ACCUMULATIONS HERE. THEREFORE CANCELLED THE WINTER WEATHER ADVISORY FOR COZ007. WEBCAMS AND RADAR STILL SHOW SNOW BANDS STREAMING ACROSS THE FLATTOPS...THE I-70 CORRIDOR FROM GLENWOOD SPRINGS TO VAIL PASS...AND STEAMBOAT. REMAINING HIGHLITES LOOK ON TRACK. UPDATE ISSUED AT 536 PM MST WED JAN 30 2013 PERSISTENT SNOW OVER THE I-70 CORRIDOR WEST OF EAGLE AND EAST OF PALISADE HAD ALREADY BROUGHT 1 TO 2 INCHES OF SNOW TO THESE AREAS EARLY THIS EVENING. LATEST NAM12 AND RAP13 DATA INDICATED THIS PERSISTENT BAND OF SNOW COULD LAST THROUGH THE EVENING BRINGING FROM 2 TO 5 INCHES OF BY EARLY MORNING. THEREFORE...A WINTER WEATHER ADVISORY HAS BEEN ISSUED ZONES 7 AND 8. AREAS IN ZONE 8 ARE NOT INCLUDED IN THIS ADVISORY. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 302 PM MST WED JAN 30 2013 SNOW AND WIND IMPACTING THE NERN PART OF THE FORECAST AREA TODAY. CLASSIC OROGRAPHIC SNOW IN NORTHWEST FLOW AS PACIFIC MOISTURE AND STRONG JET TARGETS THE PARK/GORE RANGES AND THE FLAT TOP MOUNTAINS. MT WERNER SENSORS SHOW WIND OF 25 MPH BUT GUSTS TO AROUND 40 MPH. GIVEN LOW SNOW TO LIQUID RATIO VALUES...WEB CAMS SHOWING POOR VISIBILITY OVER THE MOUNTAIN PASSES. SNOTEL SITES SHOWING 6 HOUR QPF GENERALLY RANGING FROM /0.20/ TO /0.50/ INCHES...BUT THIS MAY EQUATE TO 5 TO 13 INCHES OF SNOW IF LIQUID TO WATER RATIO IS AROUND 25:1 OR HIGHER. THE HEAVIEST SNOW APPEARS CONFINED ABOVE 8500 FEET...OBSERVATIONS FROM THE PUBLIC AND SPOTTER REPORTS SUGGEST ONLY LIGHT SNOW IN THE MOUNTAIN VALLEYS (FROM MARBLE AND ASPEN). MODEL DATA KEEPS MOISTURE STREAM AND OROGRAPHIC SNOW ONGOING THROUGH THE NIGHT...BUT GRADUALLY TAPERS OFF ON THURSDAY. GRADIENT FLOW DOES WEAKEN ON THURSDAY WITH MOISTURE STREAM SOMEWHAT WEAKER...THEREFORE EXPECT SNOWFALL RATES TO DIMINISH ON THURSDAY. NO CHANGES TO THE CURRENT WINTER STORM WARNINGS AS ACCUMULATING SNOWFALL COMBINED WITH WIND WILL PERSIST INTO THURSDAY. IN ADDITION...AN EMBEDDED DISTURBANCE IN NORTHWEST FLOW RACES ACROSS THE NRN DIVIDE MOUNTAINS LATE THURSDAY AFTERNOON. ONCE THIS SHORT WAVE CROSSES THE DIVIDE...EXPECT SNOW AND WIND TO TAPER OFF CONSIDERABLY. FOR THE REMAINDER OF THE FORECAST AREA...MUCH OF EASTERN UTAH AND EXTREME WRN COLORADO WILL BE DRY. EXTENSIVE CLOUD COVER THAT COVERS MUCH OF THE REGION TODAY WILL GRADUALLY ERODE AWAY. MORE SUN EXPECTED ON THURSDAY ACROSS THE SWRN HALF OF THE FORECAST AREA. WITH LESS CLOUD COVER... EXPECT OVERNIGHT TEMPS ON FRIDAY MORNING TO BE THE COLDEST OF THE WEEK FOR THE NRN AND CENTRAL VALLEYS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 302 PM MST WED JAN 30 2013 A WAVE IN NW FLOW WILL CLIP NW CO FRI AS IT MOVES INTO THE PLAINS. THE GFS/ECMWF/CANADIAN MODELS IN GENERAL AGREEMENT HERE AND HAVE BOOSTED POPS FOR THE ELKHEAD AND PARK RANGES BASED ON THIS. A PERIOD OF Q-FORCING ALOFT WITH WARM ADVECTIVE UPLIFT AT MTN TOP LEVEL AND WITH W-NW OROGRAPHICS SHOULD RESULT IN SOME AREAS OF SNOW FROM ABOUT MIDDAY FRI INTO FRI EVENING. THIS WEEKEND LOOKS DRY AS THE WEST COAST RIDGE SLIDES OVER THE FORECAST AREA. A SMALL CLOSED LOW CURRENTLY DEVELOPING OFF THE CA COAST IS FORECAST TO SHEAR INLAND AND WEAKEN WHILE A LARGER PACIFIC TROUGH SPLITS AS IT APPROACHES THE COAST. THIS MORNING/S MODELS WERE IN GENERAL AGREEMENT WITH TAKING THE SOUTHERN PORTION OF THE SPLIT AND FORMING A CUT-OFF LOW WELL OFF THE CA COAST...WHILE THE NORTHERN SPLIT BRUSHES OUR FORECAST ABOUT SUNDAY. NEITHER THE GFS NOR ECMWF SHOW MUCH CHANCE OF SIGNIFICANT PRECIPITATION THOUGH FROM THE NORTHERN WAVE THOUGH. GFS HAS BEEN INCONSISTENT HANDLING THE SOUTHERN SPLIT CUT-OFF LOW...ALTERNATING BETWEEN BRINGING TO ABOUT THE 4 CORNERS BY TUE AND KEEPING IT OFFSHORE INLINE WITH THE MORE CONSISTENT ECMWF. FOLLOWING MORE THE PREFERRED ECMWF WOULD RESULT IN GENERAL RIDGING OVER ERN UT/WRN CO EARLY NEXT WEEK AND A MINIMAL CHANCE OF PRECIP. BUT BOTH THE GFS AND ECMWF SHOW A DECENT TROUGH APPROACHING THE PACIFIC NW COASTLINE ON WEDNESDAY...FOR POTENTIALLY UNSETTLED WEATHER LATE NEXT WEEK. TEMPERATURES ARE EXPECTED TO GRADUALLY MODERATE THIS PERIOD ALTHOUGH TEMPS WILL STILL BE A BIT OF A CHALLENGE IN MANY VALLEYS. SNOW COVER WILL KEEP TEMPS IN THE EASTERN UINTA BASIN LAGGING THE MOST BEHIND...HOWEVER...WHERE AN INVERSION SHOULD BE SLOW TO ERODE. INVERSIONS WILL NOT BE A STRONG FOR THE GRAND VALLEY WHERE SNOW COVER IS DIMINISHING IN AREAL EXTENT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1015 PM MST WED JAN 30 2013 A PERSISTENT MOIST NORTHWEST FLOW WILL CONTINUE TO DELIVER SNOW TO THE NORTHERN AND CENTRAL MOUNTAINS AND ADJACENT VALLEYS DURING THE REMAINDER OF THE NIGHT. AS A RESULT...EXPECT KSBS AND KASE TO HAVE PERSISTENT MVFR CIGS AND VSBY WITH OCCASIONAL IFR CONDITIONS DURING MUCH OF THE REMAINDER OF THE NIGHT WITH SURROUNDING MOUNTAINS OBSCURED IN SNOW. KRIL...KGWS...AND KGUC WILL HAVE OCCASIONAL MVFR CIGS AND VSBY IN SNOW SHOWERS THROUGH 12Z THURSDAY. MODELS CONTINUE TO GENERATE MOUNTAIN SNOW OVER THE NORTHERN AND CENTRAL MOUNTAINS THURSDAY THROUGH MIDNIGHT...THOUGH LIGHTER IN INTENSITY AND LESS EXTENSIVE. ADJACENT TERMINALS ARE UNLIKELY TO DROP BELOW VFR CONDITIONS THURSDAY. AREAS WEST OF A KPSO TO KCAG LINE WILL HAVE VFR CONDITIONS THROUGH THE NEXT 24 HOURS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL 8 AM MST THIS MORNING FOR COZ008. WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-005- 010-013. UT...NONE. && $$ UPDATE...MDA SHORT TERM...PF LONG TERM...JAD AVIATION...NL
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1130 PM MST WED JAN 30 2013 .UPDATE... ISSUED AT 1130 PM MST WED JAN 30 2013 BASED ON RADAR AND SATELLITE OBSERVATIONS...THE PERSISTENT SNOW BANDS THAT BROUGHT SNOW TO THE I-70 CORRIDOR HAVE SHIFTED EASTWARD WITH CONDITIONS IMPROVING FROM RIFLE TO SILT BASED ON OBSERVATIONS AND WEBCAMS. THIS IS CONSISTENT WITH THE LATEST RAP DATA SHOWING LITTLE IF ANY ADDITIONAL ACCUMULATIONS HERE. THEREFORE CANCELLED THE WINTER WEATHER ADVISORY FOR COZ007. WEBCAMS AND RADAR STILL SHOW SNOW BANDS STREAMING ACROSS THE FLATTOPS...THE I-70 CORRIDOR FROM GLENWOOD SPRINGS TO VAIL PASS...AND STEAMBOAT. REMAINING HIGHLITES LOOK ON TRACK. UPDATE ISSUED AT 536 PM MST WED JAN 30 2013 PERSISTENT SNOW OVER THE I-70 CORRIDOR WEST OF EAGLE AND EAST OF PALISADE HAD ALREADY BROUGHT 1 TO 2 INCHES OF SNOW TO THESE AREAS EARLY THIS EVENING. LATEST NAM12 AND RAP13 DATA INDICATED THIS PERSISTENT BAND OF SNOW COULD LAST THROUGH THE EVENING BRINGING FROM 2 TO 5 INCHES OF BY EARLY MORNING. THEREFORE...A WINTER WEATHER ADVISORY HAS BEEN ISSUED ZONES 7 AND 8. AREAS IN ZONE 8 ARE NOT INCLUDED IN THIS ADVISORY. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 302 PM MST WED JAN 30 2013 SNOW AND WIND IMPACTING THE NERN PART OF THE FORECAST AREA TODAY. CLASSIC OROGRAPHIC SNOW IN NORTHWEST FLOW AS PACIFIC MOISTURE AND STRONG JET TARGETS THE PARK/GORE RANGES AND THE FLAT TOP MOUNTAINS. MT WERNER SENSORS SHOW WIND OF 25 MPH BUT GUSTS TO AROUND 40 MPH. GIVEN LOW SNOW TO LIQUID RATIO VALUES...WEB CAMS SHOWING POOR VISIBILITY OVER THE MOUNTAIN PASSES. SNOTEL SITES SHOWING 6 HOUR QPF GENERALLY RANGING FROM /0.20/ TO /0.50/ INCHES...BUT THIS MAY EQUATE TO 5 TO 13 INCHES OF SNOW IF LIQUID TO WATER RATIO IS AROUND 25:1 OR HIGHER. THE HEAVIEST SNOW APPEARS CONFINED ABOVE 8500 FEET...OBSERVATIONS FROM THE PUBLIC AND SPOTTER REPORTS SUGGEST ONLY LIGHT SNOW IN THE MOUNTAIN VALLEYS (FROM MARBLE AND ASPEN). MODEL DATA KEEPS MOISTURE STREAM AND OROGRAPHIC SNOW ONGOING THROUGH THE NIGHT...BUT GRADUALLY TAPERS OFF ON THURSDAY. GRADIENT FLOW DOES WEAKEN ON THURSDAY WITH MOISTURE STREAM SOMEWHAT WEAKER...THEREFORE EXPECT SNOWFALL RATES TO DIMINISH ON THURSDAY. NO CHANGES TO THE CURRENT WINTER STORM WARNINGS AS ACCUMULATING SNOWFALL COMBINED WITH WIND WILL PERSIST INTO THURSDAY. IN ADDITION...AN EMBEDDED DISTURBANCE IN NORTHWEST FLOW RACES ACROSS THE NRN DIVIDE MOUNTAINS LATE THURSDAY AFTERNOON. ONCE THIS SHORT WAVE CROSSES THE DIVIDE...EXPECT SNOW AND WIND TO TAPER OFF CONSIDERABLY. FOR THE REMAINDER OF THE FORECAST AREA...MUCH OF EASTERN UTAH AND EXTREME WRN COLORADO WILL BE DRY. EXTENSIVE CLOUD COVER THAT COVERS MUCH OF THE REGION TODAY WILL GRADUALLY ERODE AWAY. MORE SUN EXPECTED ON THURSDAY ACROSS THE SWRN HALF OF THE FORECAST AREA. WITH LESS CLOUD COVER... EXPECT OVERNIGHT TEMPS ON FRIDAY MORNING TO BE THE COLDEST OF THE WEEK FOR THE NRN AND CENTRAL VALLEYS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 302 PM MST WED JAN 30 2013 A WAVE IN NW FLOW WILL CLIP NW CO FRI AS IT MOVES INTO THE PLAINS. THE GFS/ECMWF/CANADIAN MODELS IN GENERAL AGREEMENT HERE AND HAVE BOOSTED POPS FOR THE ELKHEAD AND PARK RANGES BASED ON THIS. A PERIOD OF Q-FORCING ALOFT WITH WARM ADVECTIVE UPLIFT AT MTN TOP LEVEL AND WITH W-NW OROGRAPHICS SHOULD RESULT IN SOME AREAS OF SNOW FROM ABOUT MIDDAY FRI INTO FRI EVENING. THIS WEEKEND LOOKS DRY AS THE WEST COAST RIDGE SLIDES OVER THE FORECAST AREA. A SMALL CLOSED LOW CURRENTLY DEVELOPING OFF THE CA COAST IS FORECAST TO SHEAR INLAND AND WEAKEN WHILE A LARGER PACIFIC TROUGH SPLITS AS IT APPROACHES THE COAST. THIS MORNING/S MODELS WERE IN GENERAL AGREEMENT WITH TAKING THE SOUTHERN PORTION OF THE SPLIT AND FORMING A CUT-OFF LOW WELL OFF THE CA COAST...WHILE THE NORTHERN SPLIT BRUSHES OUR FORECAST ABOUT SUNDAY. NEITHER THE GFS NOR ECMWF SHOW MUCH CHANCE OF SIGNIFICANT PRECIPITATION THOUGH FROM THE NORTHERN WAVE THOUGH. GFS HAS BEEN INCONSISTENT HANDLING THE SOUTHERN SPLIT CUT-OFF LOW...ALTERNATING BETWEEN BRINGING TO ABOUT THE 4 CORNERS BY TUE AND KEEPING IT OFFSHORE INLINE WITH THE MORE CONSISTENT ECMWF. FOLLOWING MORE THE PREFERRED ECMWF WOULD RESULT IN GENERAL RIDGING OVER ERN UT/WRN CO EARLY NEXT WEEK AND A MINIMAL CHANCE OF PRECIP. BUT BOTH THE GFS AND ECMWF SHOW A DECENT TROUGH APPROACHING THE PACIFIC NW COASTLINE ON WEDNESDAY...FOR POTENTIALLY UNSETTLED WEATHER LATE NEXT WEEK. TEMPERATURES ARE EXPECTED TO GRADUALLY MODERATE THIS PERIOD ALTHOUGH TEMPS WILL STILL BE A BIT OF A CHALLENGE IN MANY VALLEYS. SNOW COVER WILL KEEP TEMPS IN THE EASTERN UINTA BASIN LAGGING THE MOST BEHIND...HOWEVER...WHERE AN INVERSION SHOULD BE SLOW TO ERODE. INVERSIONS WILL NOT BE A STRONG FOR THE GRAND VALLEY WHERE SNOW COVER IS DIMINISHING IN AREAL EXTENT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1015 PM MST WED JAN 30 2013 A PERSISTENT MOIST NORTHWEST FLOW WILL CONTINUE TO DELIVER SNOW TO THE NORTHERN AND CENTRAL MOUNTAINS AND ADJACENT VALLEYS DURING THE REMAINDER OF THE NIGHT. AS A RESULT...EXPECT KSBS AND KASE TO HAVE PERSISTENT MVFR CIGS AND VSBY WITH OCCASIONAL IFR CONDITIONS DURING MUCH OF THE REMAINDER OF THE NIGHT WITH SURROUNDING MOUNTAINS OBSCURED IN SNOW. KRIL...KGWS...AND KGUC WILL HAVE OCCASIONAL MVFR CIGS AND VSBY IN SNOW SHOWERS THROUGH 12Z THURSDAY. MODELS CONTINUE TO GENERATE MOUNTAIN SNOW OVER THE NORTHERN AND CENTRAL MOUNTAINS THURSDAY THROUGH MIDNIGHT...THOUGH LIGHTER IN INTENSITY AND LESS EXTENSIVE. ADJACENT TERMINALS ARE UNLIKELY TO DROP BELOW VFR CONDITIONS THURSDAY. AREAS WEST OF A KPSO TO KCAG LINE WILL HAVE VFR CONDITIONS THROUGH THE NEXT 24 HOURS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL 2 AM MST THURSDAY FOR COZ008. WINTER STORM WARNING UNTIL 6 PM MST THURSDAY FOR COZ004-005-010- 013. UT...NONE. && $$ UPDATE...MDA SHORT TERM...PF LONG TERM...JAD AVIATION...NL
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1000 PM MST WED JAN 30 2013 .UPDATE...NO CHANGES NEED TO THE CURRENT FORECAST. WINDS CONTINUE TO BLOW OVER THE MOUNTAINS AND FOOTHILLS WITH GUSTS IN THE 40 TO 60 MPH RANGE...WITH BERTHOUD PASS JUST GUSTING TO 65 MPH. SNOTEL OBSERVATIONS STILL SHOWING THE OROGRAPHIC SNOW PRODUCTION...WITH AREAS RECEIVING BETWEEN HALF AN INCH TO UP TO AN INCH AN HOUR WITH THE HIGHEST AMOUNTS NEAR RABBIT EARS PASS. WINTER STORM WARNING STILL IN EFFECT UNTIL THURSDAY EVENING. SOME OF THE LATEST MODELS ARE SHOWING LESS MOISTURE UPSTREAM...SO THE ENDING TIME OF THE WARNING MAY HAVE TO BE ADJUSTED. HOWEVER...THE WIND WILL CONTINUE TO BE QUITE STRONG TO CONTRIBUTE TO THE HAZARDOUS WEATHER. && .AVIATION...SOUTHWEST WILL PREVAIL TONIGHT AT DEN AND APA AS DRAINAGE FLOW DEVELOPS WITH SPEEDS AROUND 12 KTS. WINDS TO REMAIN WEST TO NORTHWEST AT BJC THROUGH THE EVENING AND OVERNIGHT...WITH SOME GUSTS TO 40 KTS POSSIBLE AFTER 06Z. ON THURSDAY...WINDS TO BECOME NORTHWEST AND WEAKEN ACROSS THE AREA AFTER 16Z. SOME GUSTS TO 25 KTS WILL BE POSSIBLE AT BJC. VFR TO PREVAIL. && .PREV DISCUSSION... /ISSUED 355 PM MST WED JAN 30 2013/ SHORT TERM...STRONG NORTHWEST FLOW ALOFT OVER AREA WITH OROGRAPHICS CONTINUING ACROSS MOUNTAINS. WEB CAMS INDICATE SNOW CONTINUING ACROSS MOUNTAINS...THOUGH HAS SHOWN SOME SIGNS OF DECREASING DURING THE PAST FEW HOURS. STABILITY HAS BEEN LIMITED...WHICH HAS HINDERED THE HEAVIER SNOW RATES. STILL..WINDS BEEN QUITE GUSTY ACROSS THE RIDGES...WITH A RECENT GUST TO 71 MPH ATOP BERTHOUD PASS WHILE OTHER GUSTS WERE MAINLY IN THE 50S. THE WINDS WERE CREATING AREAS OF BLOWING SNOW ACROSS THE MOUNTAIN PASSES. GUSTY WINDS ALSO OCCURRING IN AND NEAR FOOTHILLS WITH GUSTS MAINLY IN THE 40S. ACROSS PLAINS WEAK MESOCYCLONE SLIDING SOUTH ACROSS MORGAN COUNTY KEEPING GUSTY WINDS FROM SPREADING EAST ACROSS URBAN CORRIDOR. FLOW ALOFT REMAINS STRONG TONIGHT AND INCREASES SLIGHTLY AS SHOWN BY RAP CROSS SECTIONS. AIRMASS TO REMAIN QUITE MOIST ACROSS THE MOUNTAINS ALONG WITH CONTINUED OROGRAPHICS AND SNOWFALL. STABILITY SHOULD IMPROVE OVERNIGHT... HELPING WITH SNOWFALL RATES. ADDITIONAL 3 TO 6 INCHES STILL POSSIBLE ON FAVORED WEST FACING SLOPES WITH LESSER AMOUNTS ELSEWHERE. MODEL CROSS SECTIONS SHOW WEAK MOUNTAIN WAVE DEVELOPING OVERNIGHT WHICH WILL HELP TO INCREASE WINDS. GUSTS AROUND 70 MPH POSSIBLE ALONG THE HIGHER RIDGES...WITH GUSTS UP TO 60 MPH ALONG THE FOOTHILLS. THE GUSTY WINDS WILL CONTINUE TO CREATE CONSIDERABLE BLOWING SNOW OVER THE MOUNTAIN PASSES WITH POSSIBLE WHITE OUT CONDITIONS ABOVE TIMBERLINE. ACROSS PLAINS...WINDS TO BE A BIT GUSTY NEAR THE FOOTHILLS AND WYOMING BORDER WITH LESS WIND ELSEWHERE. MODELS CONTINUE TO SHOW AN AREA OF LIGHT SNOW DEVELOPING ALONG THE WYOMING BORDER TONIGHT IN VICINITY OF UPPER JET. OTHERWISE...DRY CONDITIONS TO PREVAIL. ON THURSDAY...STRONG NORTHWEST FLOW ALOFT TO CONTINUE THOUGH MODEL CROSS SECTIONS INDICATE MOISTURE ACROSS MOUNTAINS DECREASING BY THE AFTERNOON AS STABILITY INCREASES. STILL DECENT OROGRAPHICS IN PLACE FOR MUCH OF THE DAY ALONG WITH GUSTY WINDS. SHOULD SEE SNOW GRADUALLY DECREASE DURING THE DAY THOUGH THERE WILL STILL BE QUITE A BIT OF BLOWING SNOW. WILL MAINTAIN THE WARNING THROUGH THE DAY THOUGH ADDITIONAL SNOWFALL SHOULD BE LIGHT. WINDS TO BE A BIT GUSTY IN AND NEAR THE FOOTHILLS AS A WEAK SURFACE TROUGH IS EXPECTED TO DEVELOP. FURTHER EAST...MODELS CONTINUE TO SHOW A WEAK COLD FRONT MOVING INTO THE NORTHEAST CORNER. WITH UPPER JET IN VICINITY... THERE COULD BE A SLIGHT CHANCE OF LIGHT SNOW IN THE FAR NEAR THE WYOMING BORDER. OTHERWISE DRY CONDITIONS WILL PREVAIL. LONG TERM...A RATHER BENIGN WEEK OF WEATHER IS EXPECTED AFTER THE SNOW SHOWERS CLEAR OUT OF THE MOUNTAINS THURSDAY NIGHT. ON THURSDAY EVENING...A FEW SNOW SHOWERS MAY BE LINGERING...BUT THEY WILL BE ON THE DECREASE AS SUBSIDENCE OVER THE STATE INCREASES. DRY...NORTHWESTERLY FLOW ALOFT IS FORECAST TO CONTINUE THROUGH THE PERIOD AS AN UPPER RIDGE REMAINS ANCHORED OFF THE WEST COAST AND A DEEP TROUGH CONTINUES OVER THE EASTERN UNITED STATES. THE ECMWF AND GFS ARE IN GOOD AGREEMENT THROUGH THE WEEKEND...BUT AT THE END THE TWO MODELS HAVE DIFFERENT IDEAS ABOUT A TROUGH THAT DEVELOPS OFF THE CALIFORNIA COAST. IF A TROUGH DEVELOPS...IT IS NOT EXPECTED TO MOVE INTO THE CENTRAL ROCKIES UNTIL THE MIDDLE OF NEXT WEEK. TEMPERATURES SHOULD GRADUALLY MODERATE THROUGH THE UPCOMING FORECAST PERIOD AS THE NORTHWEST FLOW ALOFT CONTINUES. AVIATION... WINDS HAVE BECOME LIGHT NORTHEAST AT DEN DUE TO WEAK MESOCYCLONE OVER MORGAN COUNTY. GUSTY WEST TO NORTHWEST WINDS CONTINUE AT APA AND BJC. WINDS TO BECOME NORTHWEST AT DEN BY 00Z AS MESOCYCLONE SHIFTS EAST INTO WASHINGTON COUNTY. AFTER 03Z...WINDS SHOULD SHIFT TO THE SOUTHWEST AT DEN AND APA AS DRAINAGE FLOW DEVELOPS WITH SPEEDS AROUND 12 KTS. WINDS TO REMAIN WEST TO NORTHWEST AT BJC THROUGH THE EVENING AND OVERNIGHT...WITH SOME GUSTS TO 40 KTS POSSIBLE AFTER 06Z. ON THURSDAY...WINDS TO BECOME NORTHWEST AND WEAKEN ACROSS THE AREA AFTER 16Z. SOME GUSTS TO 25 KTS WILL BE POSSIBLE AT BJC. VFR TO PREVAIL. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 PM MST THURSDAY FOR COZ031-033-034. && $$ SHORT TERM...D-L LONG TERM....DANKERS UPDATE/AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS ALBANY NY
415 PM EST THU JAN 31 2013 .SYNOPSIS... S A CANADIAN AIR MASS MOVES INTO THE REGION... TEMPERATURES WILL BE MUCH COLDER TONIGHT WITH A DIMINISHING WIND. LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO AFFECT THE WESTERN ADIRONDACKS AND MOHAWK VALLEY OVERNIGHT. LAKE EFFECT SNOW WILL SHIFT SOUTH AND WEST OF THE REGION TOMORROW...WITH COLD TEMPERATURES AND BREEZY CONDITIONS. SEASONABLY CHILLY TEMPERATURES WILL CONTINUE TO BE IN PLACE OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 415 PM EST...WINDS ARE STARTING TO DIMINISH AS THE PRESSURE GRADIENT BEGINS TO RELAX. THE PRESSURE COUPLET ASSOCIATED WITH THE SFC FRONTAL BOUNDARY IS WELL NORTHEAST OF THE REGION ACROSS ATLANTIC CANADA. STILL...A FEW GUSTS OF 25-40 MPH ARE OCCURRING LATE THIS AFTN...SO WE WILL LET THE CURRENT HIGH WIND WARNING EXPIRE AT 6 PM. BY THAT POINT...WINDS WILL STILL BE BREEZY FOR THE OVERNIGHT HOURS...BUT NOT ENOUGH TO CAUSE DAMAGE. A BAND OF LAKE EFFECT SNOW IS CURRENTLY ONGOING ACROSS THE WESTERN ADIRONDACKS. THE LOCAL HIRES WRF MODEL...AS WELL AS THE NAM12 AND 3KM HRRR MODEL...SHOWS THIS BAND TO SHIFT SOUTHWARD DURING THE OVERNIGHT HOURS. WITH THIS BAND HAVING AN EXCELLENT MULTI-LAKE CONNECTION ALL THE WAY BACK TO THE WESTERN GREAT LAKES AND STRONG LOW LEVEL SPEED SHEAR...LOCAL CSTAR RESEARCH WOULD SUGGEST THAT THIS BAND REACHES WELL INTO OUR AREA. AS A RESULT...HAVE ALSO INCLUDED A LAKE EFFECT SNOW ADVISORY FOR HAMILTON COUNTY...IN ADDITION TO THE WSW ALREADY IN EFFECT FOR NRN HERKIMER. SNOW TOTALS LOOK TO REACH 4-8 INCHES IN NRN HERKIMER AND 3-6 INCHES ACROSS WESTERN HAMILTON COUNTY. AS THE BAND SHIFTS SOUTH FOR LATE TONIGHT...IT SHOULD MOVE QUICKLY. WHILE A QUICK FEW INCHES OF ACCUMULATION IS POSSIBLE ACROSS THE MOHAWK VALLEY...IT SHOULD MOVE QUICK ENOUGH SOUTHWARD TO PREVENT ANY MODERATE ACCUMULATION OF SNOW. AS A RESULT...WE WILL NOT ISSUE ANY LAKE EFFECT ADVISORIES FOR THE MOHAWK VALLEY AREA...BUT WILL CONTINUE TO MENTION IN OUR HWO STATEMENT. ELSEWHERE...SOME UPSLOPE SNOW SHOWERS ARE POSSIBLE FOR THE HIGH TERRAIN OF WESTERN NEW ENGLAND WITH SOME MINOR SNOW ACCUMULATION POSSIBLE. THE REMAINDER OF THE REGION LOOKS TO BE DRY...ALTHOUGH AS THE LAKE BAND SHIFTS SOUTHWARD...THE INLAND EXTENT MAY ALLOW FOR SOME FLAKES TO REACH THE CAPITAL REGION FOR 08Z-12Z. NOT EXPECTING MUCH ACCUMULATION...BUT IT/S POSSIBLE FOR A COATING OF SNOW IN THE ALBANY/SCHENECTADY/TROY AREA BY LATE IN THE NIGHT TOWARDS DAYBREAK. MIN TEMPS WILL BE MUCH COOLER THAN LAST NIGHT. MINS WILL RANGE FROM THE SINGLE DIGITS IN THE ADKS TO THE LOW TO MID 20S IN THE MID HUDSON VALLEY. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... MAINLY DRY AND SEASONABLY COOL WEATHER IS EXPECTED THROUGH THE SHORT TERM PERIOD. THE LAKE BAND WILL SHIFT SOUTH AND WEST OF THE CWA BY FRIDAY MORNING...MAINLY ENDING THE THREAT FOR LAKE EFFECT IN OUR AREA. THE EXCEPTION MAY BE A FEW HOURS OF SNOW FOR WESTERN SCHOHARIE COUNTY WITH SOME LIGHT SNOW ACCUMULATION EARLY FRIDAY MORNING BEFORE THE BAND SHIFTS AWAY FROM THE AREA. MAX TEMPS WILL BE NOTICEABLY COOLER...WITH TEENS AND 20S ACROSS THE AREA. IN ADDITION...DAYTIME MIXING WILL ALLOW FOR SOME GUSTY WINDS...SO IT WILL FEEL EVEN COLDER...WITH SOME GUSTS OF 15-30 MPH POSSIBLE. WE WILL CONTINUE TO MENTION LOW CHC OR SLIGHT CHC POPS FOR FAR WESTERN AREAS FOR FRIDAY AFTERNOON...IN CASE UPSLOPE FLOW DOES ALLOW FOR SOME LIGHT SNOW SHOWERS...BUT ANY ADDITIONAL SNOW ACCUMULATION LOOKS LIGHT. THE HUDSON VALLEY AREA SHOULD REMAIN MAINLY DRY. CHILLY...BUT SEASONABLE TEMPS...ARE EXPECTED FRIDAY NIGHT WITH TEMPS RANGING FROM A FEW DEGREES BELOW ZERO ACROSS THE ADIRONDACKS TO THE MID TEENS IN THE HUDSON VALLEY/NW CT. A WEAK SHORTWAVE WILL PASS TO THE NORTH OF THE REGION ON SATURDAY INTO SATURDAY NIGHT. THIS MAY ALLOW FOR SOME LIGHT SNOW SHOWERS ACROSS THE ADIRONDACKS...OTHERWISE IT LOOKS CONTINUED DRY AND COOL. MAX TEMPS ON SATURDAY WILL MAINLY BE IN THE TEENS AND 20S. MIN TEMPS SAT NIGHT WILL RANGE FROM THE SINGLE DIGITS UP NORTH TO NEAR 20 SOUTH. && .LONG TERM /SUNDAY THROUGH THURSDAY/... MEAN UPPER TROUGH OVER EASTERN NORTH AMERICA THROUGH THE PERIOD... WITH LITTLE NORTHERN STREAM IMPULSES TRACKING RAPIDLY THROUGH THE CYCLONIC FLOW. THE TIMING OF THESE SYSTEMS IN SUCH QUICK UPPER FLOW IS IN QUESTION BUT TIMED THE BETTER CHANCES FOR SNOW IN THE SUNDAY TIME FRAME AND AGAIN IN THE MONDAY NIGHT TO TUESDAY TIME FRAME. THESE SYSTEMS COULD TRACK FAR ENOUGH EAST AND SOUTH OF OUR REGION THAT THERE COLD BE LITTLE TO NO SNOW IN MUCH OF THE FORECAST AREA... SO INDICATING BEST CHANCES IN THE MID HUDSON VALLEY...NW CT AND THE BERKSHIRES. ANY PRECIPITATION WOULD BE RELATIVELY LIGHT IN BOTH EVENTS...AND SHOULD NOT REQUIRE SNOW HEADLINES SINCE THE STORMS SHOULD BE STARVED FOR MOISTURE UNTIL THEY RAPIDLY HEAD OFFSHORE AND WELL EAST OF OUR REGION. OUTSIDE OF THESE POTENTIAL 2 SMALL EVENTS...SOME PERSISTENT LAKE EFFECT SNOW BANDS COULD EXTEND INTO THE SOUTHERN ADIRONDACKS... WESTERN MOHAWK VALLEY...SCHOHARIE VALLEY AND EASTERN CATSKILLS. SO...PERIODS OF CLOUDS THROUGH THE PERIOD WITH TEMPERATURES AROUND NORMAL SUNDAY...A LITTLE BELOW NORMAL MONDAY THROUGH WEDNESDAY AND BACK TO AROUND NORMAL THURSDAY. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... THE MAIN PROBLEM THIS AFTERNOON WILL BE THE CONTINUATION STRONG WINDS OUT OF THE WEST TO NORTHWEST...WHICH WILL OCCASIONALLY GUST NEAR 40 KT (OR BETTER) ESPECIALLY THIS AFTERNOON AT KALB. A HIGH WIND WARNING REMAINS IN EFFECT. THE WIND WILL ABATE SOMEWHAT TONIGHT BUT STILL CONTINUE TO OCCASIONALLY GUST 20 TO 25 KT OUT OF THE WEST TO NORTHWEST...LESS GUSTY AFTER ABOUT 02Z. CONDITIONS SHOULD REMAIN MAINLY VFR BUT CIGS COULD OCCASIONALLY DROP INTO THE HIGH MVFR RANGE AT KPSF DURING THE NIGHT. WEST TO NORTHWEST WINDS SHOULD BECOME GUSTY AGAIN TOMORROW AFTER ABOUT 16Z. IF THE CEILING AT KPSF DROPS TO MVFR TONIGHT...IT SHOULD BE BACK TO VFR AFTER 12Z. OUTLOOK... FRI-MON...MAINLY VFR. CHC SUB-VFR -SHSN. && .HYDROLOGY... SNOWMELT FROM THE RECENT WARMER TEMPERATURES AND RAINFALL FROM EARLY THIS MORNING COMBINED FOR SOME RUNOFF ACROSS THE REGION THIS MORNING. HOWEVER...THIS WAS NOT ENOUGH TO CAUSE FLOODING ACROSS OUR AREA. WITH TEMPERATURES COOLING BELOW FREEZING ACROSS THE ENTIRE AREA THIS EVENING...ANY SNOWMELT SHOULD END...AND RIVERS WILL START TO RECEDE. BECAUSE OF THE WARM TEMPERATURES AND RAINFALL...SOME ICE BROKE UP IN AREA RIVERS AND STREAMS. THIS CAUSED SOME MINOR FLOODING ON THE EAST CANADA CREEK IN DOLGEVILLE AND ALONG THE HOOSIC RIVER NEAR BUSKIRK. THE THREAT FOR ICE JAMS SHOULD DECREASE THIS EVENING WITH THE COOLER TEMPERATURES...AND ALTHOUGH ANY ICE THAT BROKE UP MAY BEGIN TO REFREEZE IN PLACE...LOWERING FLOWS SHOULD PREVENT ANY FLOODING FROM OCCURRING. THE NEXT SEVERAL DAYS WILL BE FAIRLY DRY...AND ANY LIGHT PRECIPITATION WILL BE IN THE FORM OF SNOW. THIS SHOULD ALLOW RIVERS AND STREAMS TO SLOWLY RECEDE INTO EARLY NEXT WEEK. FOR SPECIFIC RIVER AND LAKE FORECASTS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR CTZ001-013. NY...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR NYZ032-033- 038>043-047>054-058>061-063>066-082>084. LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST FRIDAY FOR NYZ032-033. MA...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR MAZ001-025. VT...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...NAS AVIATION...NAS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1006 AM EST Thu Jan 31 2013 ...Possible short duration light freeze tonight... ...Another freeze possible Friday night... .NEAR TERM [Through Tonight]... Updated at 945 am EST- The 12 UTC regional surface analysis showed the cold front that moved through our forecast area last night was over South FL, while a 1024 mb high pressure ridge (centered over LA) was building east along the Gulf Coast. Vapor imagery and upper air data showed a broad trough over much of the eastern CONUS, with plenty of dry air throughout the atmospheric column. Based on our 12 UTC KTAE sounding and the latest NWP guidance, we expect high temperatures today will be in the mid to upper 50s. With the ridge building in quickly, surface winds will likely become calm shortly after sunset. This will allow for rapid cooling, and a light freeze is possible at our normally coldest sites (inland, relatively "open" areas away from cities). Even for those areas that don`t quite reach freezing, frost will be possible. The one limiting factor (which could prevent a deeper freeze) will be the potential for surface winds to increase slightly shortly before dawn, ahead of a dry cold front just to the north. && .SHORT TERM [Friday Through Saturday]... High Temps both Friday and Saturday will be slightly below climatology and generally range from the upper 50s NW to the mid 60s SE. On Friday night, however, we could see one of the coldest nights of the entire Winter Season thus far, as the Sfc Ridge behind the Dry Cold Front will be positioned right overhead of the CWA. This will allow for nearly ideal conditions for Radiational Cooling with clear skies and near calm winds. Low Temps could bottom out in the middle 20s over much of the interior, which will result in at least a long duration light freeze, and the possibility of the first Hard Freeze of the season. Therefore, all outdoor interests and those with sensitive vegetation should keep abreast of the latest information from the National Weather Service in Tallahassee. && .Long Term [Sunday night through Thursday]... Undated at 945 am EST- Mostly zonal flow will dominate on the southern periphery of broad eastern U.S. troughing through the period. A weak impulse will pass overhead late on Monday, however, dry air will limit the impacts to passing high clouds with no chance for rain. A slightly stronger mid/upper wave will approach towards the end of the period. At this time, little to no rain is expected with this disturbance either. Overall, the period will be dominated by dry conditions and near or slightly above average temperatures. && .AVIATION [through 18 UTC Friday]... Undated at 945 am EST- Unlimited visibility and ceilings will prevail through the period. Winds will be NW 5 to 10 KT this afternoon, light overnight, then NW 5 to 10 KT again Friday. The only possible visibility restriction could be caused by any large fire occurring near a terminal, but currently we don`t see any "hot spots" on satellite/radar imagery that would concern us. && .MARINE... Updated at 945 am EST- Winds & seas were still solidly at advisory levels, but the latest NWP guidance (including high resolution RAP and local 4km WRF) is unanimous in having the winds fall below advisory criteria by early afternoon. Thereafter, light to moderate offshore winds and seas will dominate through Friday, with a period of cautionary northeasterly winds expected on Friday night. Then, light winds and low seas are anticipated for the upcoming weekend and beginning of next week. && .FIRE WEATHER... Very dry conditions will overspread the region today and continue into the weekend. Red flag conditions look like a near certainty across much of North Florida today and possibly again on Friday. Though RH values will be below 25 percent in Alabama and Georgia today and on Friday, it appears as though the other required criteria (winds and/or fuel moisture) will not be met. More moist conditions will return by Sunday, putting an end to any red flag concerns. && .HYDROLOGY... Despite a fairly widespread rainfall across the region on Wednesday (with most areas receiving between 0.50" and 2" of rain, with the highest amounts well to the N and W), only minor rises have been observed on area rivers thus far. The only exception appears to be the Choctawhatchee River, where the river may rise to near action stage at Caryville during the next few days. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 58 32 63 25 63 / 0 0 0 0 0 Panama City 57 42 61 36 61 / 0 0 0 0 0 Dothan 56 36 57 28 60 / 0 0 0 0 0 Albany 56 32 57 26 60 / 0 0 0 0 0 Valdosta 57 32 61 25 62 / 0 0 0 0 0 Cross City 60 30 66 26 65 / 0 0 0 0 0 Apalachicola 57 40 62 35 59 / 0 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...FREEZE WATCH from late tonight through Friday morning for Calhoun-Central Walton-Coastal Dixie-Coastal Taylor- Gadsden-Holmes-Inland Bay-Inland Dixie-Inland Franklin- Inland Gulf-Inland Jefferson-Inland Taylor-Inland Wakulla- Inland Walton-Jackson-Lafayette-Leon-Liberty-Madison- Washington. RED FLAG WARNING until 7 PM EST /6 PM CST/ this evening for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-Holmes- Inland Bay-Inland Dixie-Inland Jefferson-Inland Taylor- Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon- Liberty-Madison-South Walton-Washington. FIRE WEATHER WATCH from Friday afternoon through Friday evening for Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson- Coastal Taylor-Coastal Wakulla-Gadsden-Holmes-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Inland Walton-Jackson- Lafayette-Leon-Liberty-Madison-South Walton-Washington. GA...FREEZE WATCH from late tonight through Friday morning for Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook- Decatur-Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes- Miller-Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas- Tift-Turner-Worth. AL...FREEZE WATCH from late tonight through Friday morning for Coffee-Dale-Geneva-Henry-Houston. GM...SMALL CRAFT ADVISORY until 1 PM EST this afternoon for Apalachee Bay or Coastal Waters From Keaton Beach to Ochlockonee River Fl out to 20 Nm-Coastal Waters From Ochlockonee River to Apalachicola Fl out to 20 Nm-Coastal waters from Suwannee River to Keaton Beach out 20 NM- Coastal waters from Apalachicola to Destin FL out 20 NM- Waters from Suwannee River to Apalachicola FL from 20 to 60 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. && $$ NEAR TERM...Fournier SHORT TERM...Gould LONG TERM...Harrigan AVIATION...Fournier MARINE...Fournier/Gould FIRE WEATHER...Fournier/Gould HYDROLOGY...Gould
AREA FORECAST DISCUSSION
NWS MIAMI FL
136 AM EST THU JAN 31 2013 .AVIATION... THE LATEST MODEL GUIDANCE SHOWS A NARROW LINE OF SHOWERS ALONG THE FRONTAL BOUNDARY APPROACHING THROUGH THE FIRST FEW HOURS OF THE TAF CYCLE...THROUGH APF BY/AROUND DAYBREAK...THEN THROUGH THE EAST COAST TERMINALS THROUGH THE EARLY/MID MORNING HOURS. WINDS WILL SHIFT FROM THE SOUTH TO NORTHWEST WITH THE FROPA. ALTHOUGH A FEW PERIODS WITH MVFR CIGS CAN`T BE RULED OUT IN AND AROUND ANY SHOWERS ALONG THE FRONT...MOSTLY VFR CONDITIONS ARE EXPECTED. IN THE WAKE OF THE FRONTAL BOUNDARY...A STABLE LOW-LEVEL STATUS DECK WILL LIKELY LINGER THROUGH A GOOD PORTION OF THE DAY BEFORE GRADUALLY CLEARING. && .PREV DISCUSSION... /ISSUED 855 PM EST WED JAN 30 2013/ UPDATE... COLD FRONT MOVING THROUGH THE PANHANDLE THIS EVENING WILL APPROACH SOUTH FLORIDA AFTER MIDNIGHT TONIGHT. LOCAL WRF AND HRRR SHOW A THIN LINE OF SHOWERS APPROACHING THE NORTHWEST PORTIONS OF THE CWA AROUND 09Z TONIGHT...AND THEN THE LINE SLOWLY MOVING THROUGH THE REST OF THE REGION THROUGH THE MORNING HOURS. THE CURRENT POP GRIDS HANDLE THIS WELL...SO NO UPDATES ARE NEEDED. TEMPERATURES TONIGHT WILL BE WARM...WITH LOWS NEAR 60 TO THE LOWER 70S. ALTHOUGH WINDS WILL LIKELY FALL BELOW SCA CRITERION OVER THE LOCAL GULF WATERS THIS EVENING...KEPT THE SCA GOING AS WINDS WILL INCREASE LATE TONIGHT BEHIND THE FRONT. FOR THE ATLANTIC WATERS...WILL CANCEL THE SCA SINCE THE WINDS HAVE FALLEN TO AROUND 10-15 KNOTS AND WINDS ARE NOT EXPECTED TO INCREASE TO SCA CONDITIONS AGAIN UNTIL AFTER 18Z ON THURSDAY. PREV DISCUSSION... /ISSUED 628 PM EST WED JAN 30 2013/ AVIATION...VFR WILL PREVAIL, BUT A FEW SHOWERS/BRIEF MVFR WILL BE POSSIBLE ALONG COLD FRONT EXPECTED TO MOVE ACROSS KAPF AT AROUND SUNRISE, THEN THE EAST COAST TERMINALS BY MID MORNING THU. CURRENT WIND OBS ARE SSE BUT ACARS DATA SHOWS SSW JUST ABOVE THE SFC. VEERED WINDS THROUGH THE NIGHT TO SSW AS FRONT APPROACHES, THEN TURNED WINDS NW BEHIND THE COLD FRONT THU. GUIDANCE SUGGEST CLOUDS LIKELY WILL HANG TOUGH BEHIND THE FRONT FOR THE EAST COAST TERMINALS THROUGHOUT THE DAY THU. BEST PROSPECTS FOR SHOWERS/BRIEF MVFR CIGS LOOK TO BE 10-15Z THU, EXCEPT 06-12Z AT KAPF. THX CWSU MIAMI FOR COORDINATION. /GREGORIA PREV DISCUSSION... /ISSUED 237 PM EST WED JAN 30 2013/ SYNOPSIS... A COLD FRONT WILL MOVE THROUGH SOUTH FLORIDA THURSDAY MORNING...ENDING THE ABOVE NORMAL TEMPERATURES AND BRINGING A SLIGHT CHANCE OF SHOWERS AS IT PASSES. HIGH PRESSURE BUILDS IN FRIDAY THROUGH THE WEEKEND...WITH SLIGHTLY BELOW NORMAL TEMPERATURES RISING TO NEAR SEASONAL AVERAGES BY EARLY NEXT WEEK. SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... BREEZY CONDITIONS IN PLACE THROUGH FLORIDA AS PRESSURE GRADIENT BETWEEN THE SUBTROPICAL RIDGE OVER WESTERN ATLANTIC AND SURFACE COLD FRONT MOVING EASTWARD THROUGH THE DEEP SOUTH INCREASES. SOUTH WINDS HAVE GUSTED TO NEAR 30 KTS...JUST BELOW WIND ADVISORY CRITERION. GUSTS MAY DIURNALLY DIMINISH SLIGHTLY...BUT REMAIN HIGH ENOUGH TO PRECLUDE ANY FOG FORMATION TONIGHT. TEMPERATURES AHEAD OF THE FRONT CONTINUE TO BE ABOVE NORMAL...WITH READINGS NEAR 80F ACROSS MOST OF SOUTH FLORIDA. MODELS HAVE TRENDED A BIT SLOWER FOR FROPA FOR SOUTH FLORIDA. THE SFC FRONT LOCATED NEAR KPNS NOW WILL TREK ACROSS THE PANHANDLE THIS EVENING...THEN APPROACH I-4 CORRIDOR OVERNIGHT. IT IS NOT EXPECTED TO INTRUDE ON NORTHWEST SECTIONS OF OUR CWA UNTIL AROUND SUNRISE. THUS...WARM AND FAIRLY BREEZY NIGHT IS IN STORE. MINIMA WILL RANGE FROM AROUND 60F NORTHWEST INTERIOR TO AROUND 70F ATLANTIC METROS. THE COLD FRONT WILL MOVE ACROSS SOUTH FLORIDA DURING THE MORNING...ACCOMPANIED BY A FEW SHOWERS. DYNAMICAL FORCING WILL BE NEGLIGIBLE AND ATMOSPHERE WILL REMAIN FAIRLY STABLE...BUT LOW-LEVEL CONVERGENCE AND DECENT MOISTURE CONTENT SHOULD BE SUFFICIENT FOR SCATTERED ACTIVITY ALONG AND IN VICINITY OF SURFACE BOUNDARY. CAA WILL LAG SEVERAL HOURS BEHIND THE FRONT...SO HIGH TEMPERATURES WILL STILL REACH M/U70S MOST LOCATIONS. SKIES CLEAR AND TEMPERATURES PLUMMET THURSDAY NIGHT...AND DESPITE LACK OF IDEAL RADIATIONAL COOLING CONDITIONS...ADVECTION SHOULD SUPPORT MINIMA REACHING BELOW 50F FOR MUCH OF THE INTERIOR...AND SOME 30S ARE POSSIBLE ACROSS COLLIER...GLADES...AND HENDRY COUNTY. IT APPEARS DRY LOW LEVELS AND NON-ZERO WIND SPEEDS WILL PREVENT ANY FROST...BUT THIS WILL BE MONITORED. AFOREMENTIONED WINDS HOWEVER WILL CREATE WIND CHILL VALUES SOME 5-10 DEGREES LOWER THAN AMBIENT READINGS...LOW ENOUGH TO POSSIBLY REACH ADVISORY THRESHOLDS ACROSS MAINLY GLADES AND HENDRY COUNTIES. TEMPERATURES FRIDAY AND FRIDAY NIGHT WILL BE SLIGHTLY BELOW NORMAL...WITH L70S FOR MAXIMA AND 40S INLAND/50S COASTAL FOR MINIMA. HIGH PRESSURE BUILDING SOUTH WILL KEEP SKIES CLEAR...AND NORTH WINDS WILL GRADUALLY BECOME NORTHEAST AND BECOME QUITE LIGHT OVERNIGHT FRIDAY. TEMPERATURES ATTM APPEAR JUST ABOVE VALUES THAT WOULD CAUSE FROST CONCERN AND LACK OF WIND SHOULD PRECLUDE ANY WIND CHILL CONCERNS. LONG TERM /SATURDAY THROUGH WEDNESDAY/... THE EXTENDED PERIOD FROM THIS WEEKEND INTO THE MIDDLE OF NEXT WEEK LOOKS UNEVENTFUL AND DRY AS SEVERAL MID LEVEL TROUGHS MOVE ACROSS THE NORTHERN STATES MAINTAINING A WEST TO NORTHWEST FLOW OF DRY AIR OVER THE FLORIDA PENINSULA AND KEEPING THE MID LEVEL RIDGE SUPPRESSED TO OUR SOUTHEAST. AS THE TROUGHS MOVE TO OUR NORTH, THIS WILL ALSO REINFORCE THE SURFACE RIDGING ACROSS THE SOUTHEAST STATES WHICH IN TURN WILL KEEP THE TEMPERATURES CLOSE TO OR SLIGHTLY BELOW CLIMATOLOGICAL AVERAGES FOR THE BEGINNING OF FEBRUARY. AVIATION... GUSTY SOUTHEASTERLY WINDS WILL CONTINUE THROUGH THE TAF PERIOD AT ALL SITES. FROPA IS STILL EXPECTED ACROSS THE EAST COAST TERMINALS BETWEEN 10Z-13Z ACCOMPANIED BY SCATTERED SHOWERS. BRIEF PERIODS OF MVFR CIGS WILL LIKELY ACCOMPANY ANY SHOWER ACTIVITY BUT SHOULD NOT BE LONG ENOUGH TO PREVAIL IN THE TAF. WINDS WILL TURN AROUND TO THE NORTHWEST BEHIND THE FRONT AND REMAIN AT AROUND 10 KNOTS. MARINE... WINDS NEAR 20 KTS WITH SOUTHERLY GUSTS TO NEAR 30 KTS WARRANTED ISSUANCE OF SMALL CRAFT ADVISORY EARLY TODAY...AND THIS WILL REMAIN IN EFFECT FOR ALL MARINE ZONES OVERNIGHT. STRONG WINDS BEING INDUCED BY TIGHT PRESSURE GRADIENT IN ADVANCE OF QUICK- MOVING COLD FRONT. THIS FRONT WILL PASS THROUGH EARLY FRIDAY...WITH NORTH WINDS LIKELY EXCEEDING ADVISORY THRESHOLD BEHIND IT. STRONG WINDS AND BUILDING SEAS WILL IMPACT THE WATERS THURSDAY NIGHT THROUGH AT LEAST FRIDAY...BEFORE SUBSIDING AS HIGH PRESSURE BUILDS OVERHEAD. FIRE WEATHER... NO FIRE WEATHER CONCERNS TODAY. A COLD FRONT WILL RACE THROUGH SOUTH FLORIDA THURSDAY MORNING...WITH MUCH DRIER AIR MOVING IN IN ITS WAKE. RELATIVE HUMIDITY VALUES MAY DROP TO NEAR 35 PERCENT THURSDAY AFTERNOON ACROSS GLADES AND HENDRY COUNTIES AND NORTH WINDS WILL BE 10 TO 15 MPH OR HIGHER. FORECAST CONDITIONS DONT SUPPORT ISSUANCE OF FIRE WEATHER WATCH...BUT A FIRE DANGER STATEMENT HAS BEEN ISSUED THURSDAY. RELATIVE HUMIDITY WILL BE VERY LOW FRIDAY...BUT WINDS WILL SUBSIDE A BIT. STILL...FIRE WEATHER HEADLINES ARE LIKELY ON FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 75 52 71 54 / 30 - 0 0 FORT LAUDERDALE 79 56 72 60 / 30 - 0 0 MIAMI 80 57 72 59 / 20 - 0 0 NAPLES 71 46 71 49 / 20 - 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM- COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT 20 NM-GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM 20 TO 60 NM. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS LINCOLN IL
848 PM CST FRI FEB 1 2013 .DISCUSSION... ISSUED 845 PM CST FRI FEB 1 2013 HAVE SENT SOME ZONE/GRID UPDATES MAINLY TO REFLECT THE LATEST SNOW TRENDS. SO FAR...THE MAIN AXIS OF THE SNOW HAS BEEN EXTENDING INTO NORTHWEST ILLINOIS...WHERE THE LIFT HAS BEEN HIGHEST. HAVE SEEN A FEW FLURRIES AS FAR SOUTH AS QUINCY...BUT MOST OBSERVATIONS UPSTREAM OF CENTRAL ILLINOIS HAVE SHOWN ALTOCUMULUS PREVAILING. WILL START SEEING SOME INCREASING ISENTROPIC LIFT OVER CENTRAL ILLINOIS TOWARD LATE EVENING...AND LATEST RAP/NAM MODELS HAVE BEEN DEVELOPING AN AREA OF LIGHT SNOW NEAR THE MIDDLE OF THE CWA AND SHIFTING IT SOUTHEAST. MOST AREAS NOW EXPECTED TO RECEIVE LESS THAN AN INCH OF SNOW...BUT SOME 1 INCH OR HIGHER TOTALS ARE POSSIBLE ACROSS THE NORTHEAST AND EASTERN CWA. GEELHART && .AVIATION... ISSUED 535 PM CST FRI FEB 1 2013 MAIN CONCERN WITH THIS TAF SET WILL BE WITH DEVELOPMENT OF MVFR CONDITIONS AS AN ALBERTA CLIPPER RACES TOWARD THE AREA. MAIN SYSTEM CURRENTLY BACK IN SOUTH DAKOTA AND SHOULD TRACK INTO NORTHERN ILLINOIS OVERNIGHT. LATEST HIGH-RESOLUTION MODELS SUGGEST THE HEAVIEST SNOW AXIS MAY TRACK MORE IN NORTHERN ILLINOIS... ALTHOUGH THE RAP AND HRRR MODELS SHOW A SEPARATE AREA OF SNOW DEVELOPING TOWARD 06Z IN CENTRAL ILLINOIS. HAVE DELAYED THE STARTING TIME OF THE SNOW A BIT AS UPSTREAM OBS HAVE MOST OF THE SNOW BACK IN SOUTHERN MINNESOTA AT 23Z. MOST OF THE SNOW SHOULD BE EXITING THE AREA BY 12Z...BUT MAY SEE SOME LINGERING IN EASTERN ILLINOIS INTO MID MORNING AS THE ACTUAL COLD FRONT PASSES. CEILINGS SHOULD BE AROUND 6000 FEET MOST OF THE EVENING...THEN START TO WORK THEIR WAY DOWN. HAVE KEPT MVFR CEILINGS PREVAILING BY AROUND 06Z. MAY SEE CEILINGS BACK UP INTO VFR RANGE BY EARLY TO MID AFTERNOON...BEFORE HEADING BACK DOWN AGAIN AHEAD OF THE NEXT CLIPPER. GEELHART && .PREV DISCUSSION... ISSUED 300 PM CST FRI FEB 1 2013 THE ARCTIC OUTBREAK WILL LOSE SOME OF ITS BITE OVER THE NEXT COUPLE OF DAYS...BUT REPEATED BRUSHES WITH CLIPPER SYSTEMS JUST TO OUR NORTH-NORTHEAST WILL KEEP CHILLY AIR IN PLACE INTO NEXT WEEK. THE MAIN SNOWFALL PERIOD WILL COME TONIGHT THROUGH SATURDAY NIGHT...AS THE MORE SOUTHERLY TRACKS OF THE FIRST TWO CLIPPERS WILL ALLOW THEM TO AFFECT MORE OF CENTRAL IL. THE NEXT SET OF CLIPPERS FOR MONDAY AND TUESDAY WILL BE FARTHER NORTH ACROSS NORTHERN ILLINOIS...WITH ONLY LIMITED INFLUENCE ON OUR COUNTIES...AND MAINLY JUST THE E AND NE COUNTIES. THE EXPECTED WARM UP WILL BE A BIT TEMPERED FROM PREVIOUS INDICATIONS...WITH HIGHS REACHING THE UPPER 30S TO AROUND 40 THUR AND FRIDAY. SHORT TERM...TONIGHT THROUGH SUNDAY. CLOUDS ARE STREAMING AHEAD OF OUR INITIAL WEATHER SYSTEM FOR TONIGHT INTO SATURDAY. THE PARENT LOW IS STILL BACK OVER SOUTH DAKOTA AND NEBRASKA BUT IS MAKING STEADY PROGRESS TO THE ESE. ISENTROPIC LIFT AND LOW CONDENSATION PRESSURE DEFICITS WILL PEAK AROUND MIDNIGHT TONIGHT...AS SNOWFALL BEGINS ACROSS OUR WESTERN COUNTIES BY 9 PM OR SO. SNOWFALL WILL CONTINUE TO EXPAND EASTWARD OVER NIGHT...PRODUCING THE HEAVIER SNOWFALL AMOUNTS NORTHEAST OF A LINE FROM CANTON TO PARIS...WHERE 1 TO 2 INCHES ARE POSSIBLE BY SATURDAY MORNING. SOUTHWEST OF THERE...SNOW TOTALS WILL DROP OFF TO TRACE TO HALF INCH AMOUNTS TOWARD JACKSONVILLE. THE NEXT WAVE OF MEASURABLE SNOW IS EXPECTED SATURDAY NIGHT...ALTHOUGH LIMITED MOISTURE AND SHORTER DURATION OF SNOW WILL LIMIT THE ADDITIONAL ACCUMULATION TO LESS THAN AN INCH ACROSS CENTRAL IL. THAT SYSTEM WILL BE MORE DISJOINTED AS THE LOWER COND PRES DEF WILL PRECEDE THE BETTER ISENTROPIC LIFT...WHICH WILL ARRIVE SAT EVENING. SO A BROAD DUSTING TO A HALF INCH OF SNOW SEEMS TO BE A REASONABLE EXPECTATION FOR THAT SAT AFTERNOON/SAT NIGHT SYSTEM. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. THE LATE WEEKEND CLIPPER ON SUNDAY NIGHT AND MONDAY WILL SEE THE BEST FORCING FOR PRECIP REMAIN NORTH OF OUR COUNTIES SUNDAY NIGHT...WITH SOME LIGHT RAIN OR SNOW POSSIBLE IN OUR EASTERN AREAS ON MONDAY. LITTLE TO NO RAIN OR SNOW ACCUMS ARE EXPECTED...SO WE KEPT ONLY SLIGHT CHANCE POPS IN THE GRIDS. THE SYSTEM FOR TUESDAY WILL HAVE A BETTER ORGANIZED COUPLING OF MOISTURE AND FORCING ACROSS NORTHERN ILLINOIS...WHICH MAY PRODUCE SOME LIGHT SNOW ACROSS THE NORTHEASTERN THIRD OF OUR COUNTIES. WE MAINLY KEPT POPS DOWN IN THE SLIGHT CHANCE CATEGORY...EXCEPT FOR A SLIVER OF CHANCE POPS FROM HENRY TO EL PASO. THAT SYSTEM LOOKS LIKE IT MAY EVOLVE INTO A MORE PROMINENT SYSTEM AS THE MODELS GET CLOSER TO THE EVENT. BEYOND THAT...A COLD FRONT PROJECTED FOR THURSDAY AND THURSDAY NIGHT IS TRENDING DRIER IN THE GFS AND EVEN THE ECMWF A LITTLE. WE KEPT POPS IN THE CHANCE CATEGORY FOR RAIN OR SNOW...BUT TRENDED LOWER DUE TO THE SHIFTING TRACK OF THE PARENT SURFACE LOW FARTHER FROM IL...AND A WEAKER FRONTAL SYSTEM PASSING OVER IL. SHIMON && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
537 PM CST FRI FEB 1 2013 .DISCUSSION... ISSUED 300 PM CST FRI FEB 1 2013 THE ARCTIC OUTBREAK WILL LOSE SOME OF ITS BITE OVER THE NEXT COUPLE OF DAYS...BUT REPEATED BRUSHES WITH CLIPPER SYSTEMS JUST TO OUR NORTH-NORTHEAST WILL KEEP CHILLY AIR IN PLACE INTO NEXT WEEK. THE MAIN SNOWFALL PERIOD WILL COME TONIGHT THROUGH SATURDAY NIGHT...AS THE MORE SOUTHERLY TRACKS OF THE FIRST TWO CLIPPERS WILL ALLOW THEM TO AFFECT MORE OF CENTRAL IL. THE NEXT SET OF CLIPPERS FOR MONDAY AND TUESDAY WILL BE FARTHER NORTH ACROSS NORTHERN ILLINOIS...WITH ONLY LIMITED INFLUENCE ON OUR COUNTIES...AND MAINLY JUST THE E AND NE COUNTIES. THE EXPECTED WARM UP WILL BE A BIT TEMPERED FROM PREVIOUS INDICATIONS...WITH HIGHS REACHING THE UPPER 30S TO AROUND 40 THUR AND FRIDAY. SHORT TERM...TONIGHT THROUGH SUNDAY. CLOUDS ARE STREAMING AHEAD OF OUR INITIAL WEATHER SYSTEM FOR TONIGHT INTO SATURDAY. THE PARENT LOW IS STILL BACK OVER SOUTH DAKOTA AND NEBRASKA BUT IS MAKING STEADY PROGRESS TO THE ESE. ISENTROPIC LIFT AND LOW CONDENSATION PRESSURE DEFICITS WILL PEAK AROUND MIDNIGHT TONIGHT...AS SNOWFALL BEGINS ACROSS OUR WESTERN COUNTIES BY 9 PM OR SO. SNOWFALL WILL CONTINUE TO EXPAND EASTWARD OVER NIGHT...PRODUCING THE HEAVIER SNOWFALL AMOUNTS NORTHEAST OF A LINE FROM CANTON TO PARIS...WHERE 1 TO 2 INCHES ARE POSSIBLE BY SATURDAY MORNING. SOUTHWEST OF THERE...SNOW TOTALS WILL DROP OFF TO TRACE TO HALF INCH AMOUNTS TOWARD JACKSONVILLE. THE NEXT WAVE OF MEASURABLE SNOW IS EXPECTED SATURDAY NIGHT...ALTHOUGH LIMITED MOISTURE AND SHORTER DURATION OF SNOW WILL LIMIT THE ADDITIONAL ACCUMULATION TO LESS THAN AN INCH ACROSS CENTRAL IL. THAT SYSTEM WILL BE MORE DISJOINTED AS THE LOWER COND PRES DEF WILL PRECEDE THE BETTER ISENTROPIC LIFT...WHICH WILL ARRIVE SAT EVENING. SO A BROAD DUSTING TO A HALF INCH OF SNOW SEEMS TO BE A REASONABLE EXPECTATION FOR THAT SAT AFTERNOON/SAT NIGHT SYSTEM. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. THE LATE WEEKEND CLIPPER ON SUNDAY NIGHT AND MONDAY WILL SEE THE BEST FORCING FOR PRECIP REMAIN NORTH OF OUR COUNTIES SUNDAY NIGHT...WITH SOME LIGHT RAIN OR SNOW POSSIBLE IN OUR EASTERN AREAS ON MONDAY. LITTLE TO NO RAIN OR SNOW ACCUMS ARE EXPECTED...SO WE KEPT ONLY SLIGHT CHANCE POPS IN THE GRIDS. THE SYSTEM FOR TUESDAY WILL HAVE A BETTER ORGANIZED COUPLING OF MOISTURE AND FORCING ACROSS NORTHERN ILLINOIS...WHICH MAY PRODUCE SOME LIGHT SNOW ACROSS THE NORTHEASTERN THIRD OF OUR COUNTIES. WE MAINLY KEPT POPS DOWN IN THE SLIGHT CHANCE CATEGORY...EXCEPT FOR A SLIVER OF CHANCE POPS FROM HENRY TO EL PASO. THAT SYSTEM LOOKS LIKE IT MAY EVOLVE INTO A MORE PROMINENT SYSTEM AS THE MODELS GET CLOSER TO THE EVENT. BEYOND THAT...A COLD FRONT PROJECTED FOR THURSDAY AND THURSDAY NIGHT IS TRENDING DRIER IN THE GFS AND EVEN THE ECMWF A LITTLE. WE KEPT POPS IN THE CHANCE CATEGORY FOR RAIN OR SNOW...BUT TRENDED LOWER DUE TO THE SHIFTING TRACK OF THE PARENT SURFACE LOW FARTHER FROM IL...AND A WEAKER FRONTAL SYSTEM PASSING OVER IL. SHIMON && .AVIATION... ISSUED 535 PM CST FRI FEB 1 2013 MAIN CONCERN WITH THIS TAF SET WILL BE WITH DEVELOPMENT OF MVFR CONDITIONS AS AN ALBERTA CLIPPER RACES TOWARD THE AREA. MAIN SYSTEM CURRENTLY BACK IN SOUTH DAKOTA AND SHOULD TRACK INTO NORTHERN ILLINOIS OVERNIGHT. LATEST HIGH-RESOLUTION MODELS SUGGEST THE HEAVIEST SNOW AXIS MAY TRACK MORE IN NORTHERN ILLINOIS... ALTHOUGH THE RAP AND HRRR MODELS SHOW A SEPARATE AREA OF SNOW DEVELOPING TOWARD 06Z IN CENTRAL ILLINOIS. HAVE DELAYED THE STARTING TIME OF THE SNOW A BIT AS UPSTREAM OBS HAVE MOST OF THE SNOW BACK IN SOUTHERN MINNESOTA AT 23Z. MOST OF THE SNOW SHOULD BE EXITING THE AREA BY 12Z...BUT MAY SEE SOME LINGERING IN EASTERN ILLINOIS INTO MID MORNING AS THE ACTUAL COLD FRONT PASSES. CEILINGS SHOULD BE AROUND 6000 FEET MOST OF THE EVENING...THEN START TO WORK THEIR WAY DOWN. HAVE KEPT MVFR CEILINGS PREVAILING BY AROUND 06Z. MAY SEE CEILINGS BACK UP INTO VFR RANGE BY EARLY TO MID AFTERNOON...BEFORE HEADING BACK DOWN AGAIN AHEAD OF THE NEXT CLIPPER. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
256 PM CST THU JAN 31 2013 .DISCUSSION... 1016 AM CST FOR MORNING UPDATE... HAVE MADE A FEW ADJUSTMENTS TO NEAR TERM FORECAST THIS MORNING... TO BUMP POPS A BIT FOR OCCASIONAL SNOW SHOWERS. HAVE SEEN SOME ISOLATED VISIBILITY REDUCTIONS LESS THAN A MILE AT TIMES THIS MORNING WITH A FEW PLACES PICKING UP A DUSTING TO A TENTH OF AN INCH OR SO. HAVE ALSO TOUCHED UP SKY COVER GRIDS...ACCOUNT SIGNIFICANT OPEN PATCHES THIS MORNING ACROSS WEST/SOUTH PARTS OF CWA AND CONVECTIVE NATURE OF EXPECTED CLOUD COVER THROUGH THE DAY. MORNING ANALYSIS INDICATES DEEPENING SURFACE LOW CONTINUES TO TRACK AWAY WELL TO OUR NORTHEAST ACROSS SOUTHERN QUEBEC...WITH COLD FRONT TRAILING THROUGH NORTHERN INDIANA/CENTRAL ILLINOIS. COLD ARCTIC AIR CONTINUES TO SPREAD SOUTHEAST ACROSS THE UPPER MIDWEST BEHIND THIS FRONT...WITH SINGLE DIGIT AND SUB-ZERO TEMPS WIDESPREAD TO OUR WEST/NORTHWEST. LOOKING ALOFT...RATHER STRONG MID-LEVEL SHORT WAVE WAS NOTED OVER THE EASTERN DAKOTAS/MINNESOTA...AND THIS WAVE IS PROGGED TO CONTINUE TO MOVE SOUTHEAST ACROSS OUR AREA THROUGH THIS EVENING. SCATTERED SNOW SHOWERS...SOME FAIRLY INTENSE WITH VISIBILITY REDUCTIONS AND BRIEF MINOR ACCUMULATIONS...HAVE BEEN PREVALENT ACROSS NORTHEAST IL THIS MORNING. THESE APPEAR TO BE HIGHLY DRIVEN BY STEEP LOW LEVEL LAPSE RATES AS EVIDENCED BY 12Z ILX RAOB AND RECENT AIRCRAFT AMDAR SOUNDINGS FROM ORD...WHICH DEPICT ADIABATIC LOW LEVEL PROFILES FROM THE SURFACE UP TO ABOUT 850-800 MB. THIS ALSO COINCIDES NICELY WITH THE -12 TO -18C FAVORED TEMPERATURE LAYER FOR GOOD DENDRITIC GROWTH OF ICE CRYSTALS...OF WHICH HAVE BEEN OBSERVED AT TIMES THIS MORNING. FORECAST SOUNDINGS FROM MORNING RUNS OF THE WRF-NAM AND RAP MAINTAIN THESE STEEP LOW LEVEL LAPSE RATES THROUGH THE DAY...COINCIDENT WITH BETTER MID/UPPER LEVEL FORCING ASSOCIATED WITH THE APPROACH AND PASSAGE OF AFOREMENTIONED UPPER MIDWEST SHORT WAVE. DEPSITE DRY ADVECTION OF ARCTIC AIR AND EVEN THOUGH VIS SATELLITE IMAGERY IS NOT TOO IMPRESSIVE WITH CLOUD COVER...SUSPECT THAT THIN STRATOCU WILL CONTINUE TO DEVELOP AND PERHAPS INCREASE IN COVERAGE IN UNSTABLE LOW LEVEL THERMODYNAMIC ENVIRONMENT...AND SHOULD BE ABLE TO SUSTAIN SNOW SHOWERS AND FLURRIES WITH SUFFICIENT INTENSITY AT TIMES TO PRODUCE SOME MINOR ACCUMS IN LOCALIZED AREAS. THEREFORE HAVE BUMPED POPS TO HIGHER CHANCE CATEGORY...AND WORDED OCCASIONAL SNOW SHOWERS/FLURRIES WITH A FEW TENTHS OF AN INCH POSSIBLE FOR MUCH OF NORTHERN 2/3 OR SO OF THE CWA THROUGH THE DAY...AND THIS EVENING. MID-LEVEL TROUGH AXIS MOVES ACROSS THE REGION LATE EVENING/MIDNIGHT TIME FRAME...AFTER WHICH FORECAST SOUNDINGS DEPICT STRENGTHENING/LOWERING SUBSIDENCE INVERSION WHICH SHOULD LIMIT FURTHER MEASURABLE PRECIP THREAT. OTHERWISE...GOING FORECAST LOOKS GOOD THROUGH THIS AFTERNOON WITH TEMPS NOT GOING ANYWHERE...AND COLD...BLUSTERY CONDITIONS. RATZER //PREV DISCUSSION... 340 AM CST PRIMARY FORECAST CHALLENGE THIS MORNING IS CLOUD COVER AND ITS IMPACT ON TEMPS THE NEXT SEVERAL DAYS AS WELL AS FLURRY/LIGHT SNOW CHANCES. PHASE ONE OF ARCTIC AIR HAS MOVED INTO THE AREA WITH PHASE 2 STILL UPSTREAM AND POISED TO ARRIVE THIS AFTERNOON INTO TONIGHT. AS ALLUDED TO LAST NIGHT GUIDANCE HAS BEEN FAR TOO COLD WITH TEMPS OVERNIGHT INTO THE EARLY MORNING HOURS THIS MORNING...RUNNING IN SOME CASES MORE THAN 5F TOO COLD AT 9Z THANKS TO THE CLOUD COVER AND WIND. NO APPRECIABLE CLEARING IS ANTICIPATED PRIOR TO SUNRISE SO A VERY SLOW (1-2F EVERY HOUR OR TWO) FALL SHOULD CONTINUE THROUGH SUNRISE. WITH THE RE-ENFORCING SHOT OF COLD AIR ARRIVING THIS AFTERNOON AND A GOOD DEAL OF CLOUD COVER/GUSTY NORTHWEST WINDS DONT ANTICIPATE TEMPS TO REBOUND MUCH FROM EARLY MORNING READINGS WITH TEMPS FAIRLY STEADY MOST OF THE DAY. ALONG WITH THE ARRIVAL OF THE COLD AIR...WATER VAPOR IMAGERY SHOWS A COUPLE OF VORTS UPSTREAM OVER THE NORTHERN PLAINS THAT WILL PIVOT SOUTHEAST INTO THE AREA THIS AFTERNOON/EVENING. ICE CRYSTALS ARE LIKELY ALREADY PRESENT IN THE STRATUS DECK GIVEN THE ARCTIC TEMPS SO IT WILL REMAIN REMARKABLY EASY FOR LIGHT SNOW OR FLURRIES TO FALL OUT OF THIS STRATUS DECK TODAY INTO TONIGHT...THOUGH ACCUMULATIONS SHOULD BE MINIMAL FLAKES WILL LIKELY BE FLYING AT TIMES TODAY INTO THIS EVENING. CERTAINLY THE AIR MASS ADVECTING INTO THE AREA WILL BE VERY COLD WITH EVENING SOUNDINGS UPSTREAM SAMPLING 850MB TEMPS NEAR -20C...HOWEVER ITS NOT CLEAR HOW MUCH IF ANY CLEARING WILL TAKE PLACE TONIGHT. IN THE ABSENCE OF CLEARING...THE WINDS AND CLOUDS WOULD LIKELY KEEP TEMPS SEVERAL DEGREES WARMER THAN MOS LOWS AND SUSPECT THAT CLOUDS WILL LINGER THROUGH THE NIGHT OVER EASTERN CWA WITH SOME CLEAR LATE WEST. HAVE GENERALLY ADJUSTED LOW TEMPS UPWARD SOME FROM PREVIOUS FORECAST AND GONE A BIT ABOVE THE WARMER MOS GUIDANCE NUMBERS AS MODELS SUGGEST THAT LOW LEVEL CYCLONIC FLOW WILL PERSIST MOST OF THE NIGHT RAISING SERIOUS DOUBTS ABOUT HOW MUCH CLEARING WILL TAKE PLACE. IN ADDITION...THE AIR MASS THIS GO AROUND WILL BE A COUPLE/FEW DEGREES MILDER AT 850MB THAN THE PREVIOUS ONE AND WITH LITTLE/NO SNOW COVER MOST AREAS WOULD EXPECT LOWS TO BOTTOM OUT NO COLDER THAN LAST GO AROUND AND IN ALL LIKELIHOOD A COUPLE DEGREES WARMER (WELL LESS COLD). BASED ON THE FORECAST LOWS AND EXPECTED WINDS LOOKS LIKE NC IL STANDS A REASONABLY GOOD CHANCE OF REACHING THE -20F WIND CHILL ADVISORY CRITERIA AND SO HAVE GONE AHEAD AND ISSUED THAT ALREADY THERE. FOR CHICAGO AREA AND POINTS SOUTH AND EAST IT WILL UNDOUBTEDLY BE VERY COLD TONIGHT BUT APPEARS UNLIKELY THAT THE -20F CRITERIA WILL BE MET FOR ANY LENGTH OF TIME SO KEPT ADVISORY NORTH/WEST OF THESE AREAS. COULD SEE SOME SUNSHINE THE FIRST HALF OF THE DAY ON FRIDAY BUT WILL REMAIN QUITE COLD WITH CLOUDS ROLLING BACK IN IN THE AFTERNOON AS FAST MOVING CLIPPER DIVES SE TOWARD THE AREA. VERY LITTLE CHANGE IN MODEL GUIDANCE IN HANDLING THIS WAVE WITH SWATH OF ACCUMULATING VERY FLUFFIFIED/HIGH RATION SNOW LIKELY ACROSS NORTHERN/CENTRAL ILLINOIS FRIDAY NIGHT INTO SATURDAY MORNING. DESPITE LIMITED MOISTURE...HIGH SNOW:LIQUID RATIOS COULD SUPPORT SOLID 2-3 INCH BAND OF SNOW...WITH BEST PROJECTIONS AT THIS POINT PLACING THE HEAVIEST SNOW ALONG OR SOUTH OF I-80. GIVEN HOW LOW AMPLITUDE THIS WAVE IS WOULD NOT BE A STRETCH TO ENVISION LATER RUNS REFINING THE TRACK A BIT...BUT EVEN WITH THAT IN MIND FELT FAIRLY COMFORTABLE CONTINUING THE TREND OF BUMPING POPS UP A BIT HIGHER AGAIN THIS MORNING. SEEMINGLY NEVER ENDING PARADE OF CLIPPERS ARE PROGGED TO CONTINUE TO PIVOT AROUND THE BASE OF THE TROUGH HEADING INTO NEXT WEEK. THE 00Z ECMWF HAS COME IN A BIT DEEPER AND FARTHER WEST WITH THE POLAR VORTEX OVER THE REGION WHICH WOULD PLACE OUR CWA CLOSER TO THE COLD SIDE OF THE PATH OF THESE CLIPPERS AND ALSO CLOSER TO POTENTIAL LIGHT ACCUMULATING SNOWS. THE GEM...GFS...AND PREVIOUS ECMWF WERE QUICKER TO WEAKEN THE POLAR VORTEX ALLOWING THE CLIPPERS TO PASS TO OUR NORTH KEEPING US DRY WITH ALTERNATING BOUTS OF ABOVE AVERAGE TEMPS AND SLIGHT COOL DOWNS WITH A TREND TOWARD SLIGHTLY WEAKER COOL DOWNS WITH EACH WAVE. CONFIDENCE IS NOT TERRIBLY HIGH IN ANY ONE SOLUTION AT THIS POINT BUT A TOWARD MODERATING TEMPS DEFINITELY LOOKS REASONABLE HEADING INTO NEXT WEEK WITH LESS CERTAINTY REGARDING PRECIP CHANCES. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * W WIND GUSTING 25-30 KT THROUGH THIS EVENING THEN GUSTS 15-20 KT OVERNIGHT. * PERIODS OF -SHSN THROUGH THE EARLY EVENING...HEAVIER BANDS COULD DROP VSBY DOWN TO LESS THAN A MILE. * HIGH END MVFR TO LOW END VFR CIGS EXPECTED THROUGH TONIGHT. JEE //DISCUSSION...UPDATED 18Z... AN UPPER LEVEL SHORT WAVE TROUGH MOVED THROUGH THE DAKOTAS AND PROVIDED FORCING FOR THE BANDS OF SNOW THE AREA SAW EARLIER THIS MORNING. THE SHORTWAVE IS MOVING INTO IA WITH SHSN FORMING OVER SOUTHERN WI. AS SUCH KEPT OCNL FLURRIES IN FOR THE TERMINALS THROUGH 20Z AND EXPECTING MORE SUBSTANTIAL -SHSN AFTER 20Z. THEY COULD DEVELOP A LITTLE LATER THAN INDICATED...WITH ARND A HALF INCH OF SNOW PSBL. THE HEAVIER BANDS IN WI ARE ASSOCIATED WITH VSBY OF LESS THAN 1 MILE...BUT WILL ADDRESS THOSE HEAVIER BANDS AS THEY SET UP. OVERALL THINKING VSBYS WILL BE 4SM OR BETTER. EXPECTING CIGS TO DROP A LITTLE WITH THE SNOW AS WELL TO ARND 020. A FEW UPSTREAM OBS INDICATE 015 CIGS ARE PSBL SO WILL KEEP AN EYE ON HOW THE LOWER CIGS PROGRESS. WINDS WILL REMAIN W GUSTING TO 25 KT THROUGH THE MID AFTN WITH GUSTS INCREASING TO 25-30KT THROUGH THE EVENING. WEST WINDS GUSTING 15-20 KT ARE THEN EXPECTED OVERNIGHT UNDER THE TIGHTENED PRESSURE GRADIENT. HIGH PRESSURE SINKS SOUTH TO THE EAST OF THE TERMINALS ALLOWING SKIES TO SCATTER OUT TOMORROW. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN PRECIP FCST...MEDIUM CONFIDENCE IN TIMING AND VSBY ASSOCIATED WITH -SN/-SHSN. * HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... 12Z... FRIDAY NIGHT...ACCUMULATING SNOW BECOMING LIKELY. MVFR BECOMING IFR. SATURDAY...MVFR WITH A CHANCE OF IFR SNOW SHOWERS...MAINLY IN THE MORNING. SUNDAY...MVFR. MONDAY...VFR. TUESDAY...VFR. WEDNESDAY...VFR. TRS && .MARINE... 255 PM CST GUSTY WEST-NORTHWEST WINDS...ARCTIC AIR AND FREEZING SPRAY ARE THE MAIN CONCERNS IN THE NEAR TERM...WITH MARGINAL GALE FORCE WINDS EXPECTED ON THE SOUTH END OF THE LAKE OVERNIGHT. WINDS WILL GRADUALLY DIMINISH FRIDAY...THOUGH AIR TEMPS IN THE SINGLE DIGITS TO LOW TEENS WILL LIKELY CONTINUE TO RESULT IN FREEZING SPRAY EARLY IN THE DAY. HAVE EXTENDED INDIANA NEARSHORE SMALL CRAFT ADVISORY THROUGH EARLY SATURDAY MORNING...WHERE WAVES WILL BE A LITTLE SLOWER TO SUBSIDE IN PERSISTENT WEST-NORTHWEST FLOW. COLD CANADIAN HIGH PRESSURE WILL CONTINUE TO PUSH SOUTHEAST FROM THE LOWER MISSOURI VALLEY INTO THE SOUTHEASTERN U.S. FRIDAY EVENING... WITH WEAKER HIGH PRESSURE RIDGING MOVING ACROSS THE WESTERN LAKES AND ALLOWING THE GRADIENT TO RELAX AND WIND SPEEDS TO DIMINISH MORE SIGNIFICANTLY. A WEAK LOW WILL MOVE THROUGH THE MIDWEST SATURDAY... JUST SOUTH OF THE LAKES...WHICH MAKES FOR A LITTLE LOWER CONFIDENCE IN WIND DIRECTION AS THE GRADIENT REMAINS WEAK/BAGGY NEAR THE TROUGH. SPEEDS SHOULD BE BELOW 20 KTS HOWEVER. ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE WESTERN/NORTHERN LAKES LATE SATURDAY NIGHT HOWEVER AND WILL BRING A RENEWED PUSH OF COLDER AIR...WHICH COMBINED WITH HIGH PRESSURE ONCE AGAIN MOVING SOUTH ACROSS THE PLAINS WILL PRODUCE A PERIOD OF GUSTY NORTHWEST WINDS OF 30-35 KTS LATE SATURDAY NIGHT THROUGH EARLY SUNDAY...HAVE MENTIONED GALES ON THE SOUTH HALF SUNDAY MORNING. FREEZING SPRAY LIKELY DURING THIS TIME AS WELL... THOUGH AIR TEMPS WILL BE A BIT WARMER THAN TONIGHT/FRIDAY MORNING. HIGH PRESSURE THEN SPREADS ACROSS THE REGION AGAIN BY SUNDAY NIGHT ALLOWING WINDS TO COME DOWN FAIRLY QUICKLY. LONGER RANGE MODEL GUIDANCE DEVELOPS ANOTHER FAIRLY WEAK LOW WHICH MOVES ACROSS THE LAKES TUESDAY...THOUGH NO DEEP STORMS THROUGH MID-WEEK. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011- ILZ012-ILZ019-ILZ020...MIDNIGHT FRIDAY TO 10 AM FRIDAY. IN...NONE. LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777- LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 6 AM FRIDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM FRIDAY. SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM SATURDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
159 PM CST THU JAN 31 2013 .DISCUSSION... 1016 AM CST FOR MORNING UPDATE... HAVE MADE A FEW ADJUSTMENTS TO NEAR TERM FORECAST THIS MORNING... TO BUMP POPS A BIT FOR OCCASIONAL SNOW SHOWERS. HAVE SEEN SOME ISOLATED VISIBILITY REDUCTIONS LESS THAN A MILE AT TIMES THIS MORNING WITH A FEW PLACES PICKING UP A DUSTING TO A TENTH OF AN INCH OR SO. HAVE ALSO TOUCHED UP SKY COVER GRIDS...ACCOUNT SIGNIFICANT OPEN PATCHES THIS MORNING ACROSS WEST/SOUTH PARTS OF CWA AND CONVECTIVE NATURE OF EXPECTED CLOUD COVER THROUGH THE DAY. MORNING ANALYSIS INDICATES DEEPENING SURFACE LOW CONTINUES TO TRACK AWAY WELL TO OUR NORTHEAST ACROSS SOUTHERN QUEBEC...WITH COLD FRONT TRAILING THROUGH NORTHERN INDIANA/CENTRAL ILLINOIS. COLD ARCTIC AIR CONTINUES TO SPREAD SOUTHEAST ACROSS THE UPPER MIDWEST BEHIND THIS FRONT...WITH SINGLE DIGIT AND SUB-ZERO TEMPS WIDESPREAD TO OUR WEST/NORTHWEST. LOOKING ALOFT...RATHER STRONG MID-LEVEL SHORT WAVE WAS NOTED OVER THE EASTERN DAKOTAS/MINNESOTA...AND THIS WAVE IS PROGGED TO CONTINUE TO MOVE SOUTHEAST ACROSS OUR AREA THROUGH THIS EVENING. SCATTERED SNOW SHOWERS...SOME FAIRLY INTENSE WITH VISIBILITY REDUCTIONS AND BRIEF MINOR ACCUMULATIONS...HAVE BEEN PREVALENT ACROSS NORTHEAST IL THIS MORNING. THESE APPEAR TO BE HIGHLY DRIVEN BY STEEP LOW LEVEL LAPSE RATES AS EVIDENCED BY 12Z ILX RAOB AND RECENT AIRCRAFT AMDAR SOUNDINGS FROM ORD...WHICH DEPICT ADIABATIC LOW LEVEL PROFILES FROM THE SURFACE UP TO ABOUT 850-800 MB. THIS ALSO COINCIDES NICELY WITH THE -12 TO -18C FAVORED TEMPERATURE LAYER FOR GOOD DENDRITIC GROWTH OF ICE CRYSTALS...OF WHICH HAVE BEEN OBSERVED AT TIMES THIS MORNING. FORECAST SOUNDINGS FROM MORNING RUNS OF THE WRF-NAM AND RAP MAINTAIN THESE STEEP LOW LEVEL LAPSE RATES THROUGH THE DAY...COINCIDENT WITH BETTER MID/UPPER LEVEL FORCING ASSOCIATED WITH THE APPROACH AND PASSAGE OF AFOREMENTIONED UPPER MIDWEST SHORT WAVE. DEPSITE DRY ADVECTION OF ARCTIC AIR AND EVEN THOUGH VIS SATELLITE IMAGERY IS NOT TOO IMPRESSIVE WITH CLOUD COVER...SUSPECT THAT THIN STRATOCU WILL CONTINUE TO DEVELOP AND PERHAPS INCREASE IN COVERAGE IN UNSTABLE LOW LEVEL THERMODYNAMIC ENVIRONMENT...AND SHOULD BE ABLE TO SUSTAIN SNOW SHOWERS AND FLURRIES WITH SUFFICIENT INTENSITY AT TIMES TO PRODUCE SOME MINOR ACCUMS IN LOCALIZED AREAS. THEREFORE HAVE BUMPED POPS TO HIGHER CHANCE CATEGORY...AND WORDED OCCASIONAL SNOW SHOWERS/FLURRIES WITH A FEW TENTHS OF AN INCH POSSIBLE FOR MUCH OF NORTHERN 2/3 OR SO OF THE CWA THROUGH THE DAY...AND THIS EVENING. MID-LEVEL TROUGH AXIS MOVES ACROSS THE REGION LATE EVENING/MIDNIGHT TIME FRAME...AFTER WHICH FORECAST SOUNDINGS DEPICT STRENGTHENING/LOWERING SUBSIDENCE INVERSION WHICH SHOULD LIMIT FURTHER MEASURABLE PRECIP THREAT. OTHERWISE...GOING FORECAST LOOKS GOOD THROUGH THIS AFTERNOON WITH TEMPS NOT GOING ANYWHERE...AND COLD...BLUSTERY CONDITIONS. RATZER //PREV DISCUSSION... 340 AM CST PRIMARY FORECAST CHALLENGE THIS MORNING IS CLOUD COVER AND ITS IMPACT ON TEMPS THE NEXT SEVERAL DAYS AS WELL AS FLURRY/LIGHT SNOW CHANCES. PHASE ONE OF ARCTIC AIR HAS MOVED INTO THE AREA WITH PHASE 2 STILL UPSTREAM AND POISED TO ARRIVE THIS AFTERNOON INTO TONIGHT. AS ALLUDED TO LAST NIGHT GUIDANCE HAS BEEN FAR TOO COLD WITH TEMPS OVERNIGHT INTO THE EARLY MORNING HOURS THIS MORNING...RUNNING IN SOME CASES MORE THAN 5F TOO COLD AT 9Z THANKS TO THE CLOUD COVER AND WIND. NO APPRECIABLE CLEARING IS ANTICIPATED PRIOR TO SUNRISE SO A VERY SLOW (1-2F EVERY HOUR OR TWO) FALL SHOULD CONTINUE THROUGH SUNRISE. WITH THE RE-ENFORCING SHOT OF COLD AIR ARRIVING THIS AFTERNOON AND A GOOD DEAL OF CLOUD COVER/GUSTY NORTHWEST WINDS DONT ANTICIPATE TEMPS TO REBOUND MUCH FROM EARLY MORNING READINGS WITH TEMPS FAIRLY STEADY MOST OF THE DAY. ALONG WITH THE ARRIVAL OF THE COLD AIR...WATER VAPOR IMAGERY SHOWS A COUPLE OF VORTS UPSTREAM OVER THE NORTHERN PLAINS THAT WILL PIVOT SOUTHEAST INTO THE AREA THIS AFTERNOON/EVENING. ICE CRYSTALS ARE LIKELY ALREADY PRESENT IN THE STRATUS DECK GIVEN THE ARCTIC TEMPS SO IT WILL REMAIN REMARKABLY EASY FOR LIGHT SNOW OR FLURRIES TO FALL OUT OF THIS STRATUS DECK TODAY INTO TONIGHT...THOUGH ACCUMULATIONS SHOULD BE MINIMAL FLAKES WILL LIKELY BE FLYING AT TIMES TODAY INTO THIS EVENING. CERTAINLY THE AIR MASS ADVECTING INTO THE AREA WILL BE VERY COLD WITH EVENING SOUNDINGS UPSTREAM SAMPLING 850MB TEMPS NEAR -20C...HOWEVER ITS NOT CLEAR HOW MUCH IF ANY CLEARING WILL TAKE PLACE TONIGHT. IN THE ABSENCE OF CLEARING...THE WINDS AND CLOUDS WOULD LIKELY KEEP TEMPS SEVERAL DEGREES WARMER THAN MOS LOWS AND SUSPECT THAT CLOUDS WILL LINGER THROUGH THE NIGHT OVER EASTERN CWA WITH SOME CLEAR LATE WEST. HAVE GENERALLY ADJUSTED LOW TEMPS UPWARD SOME FROM PREVIOUS FORECAST AND GONE A BIT ABOVE THE WARMER MOS GUIDANCE NUMBERS AS MODELS SUGGEST THAT LOW LEVEL CYCLONIC FLOW WILL PERSIST MOST OF THE NIGHT RAISING SERIOUS DOUBTS ABOUT HOW MUCH CLEARING WILL TAKE PLACE. IN ADDITION...THE AIR MASS THIS GO AROUND WILL BE A COUPLE/FEW DEGREES MILDER AT 850MB THAN THE PREVIOUS ONE AND WITH LITTLE/NO SNOW COVER MOST AREAS WOULD EXPECT LOWS TO BOTTOM OUT NO COLDER THAN LAST GO AROUND AND IN ALL LIKELIHOOD A COUPLE DEGREES WARMER (WELL LESS COLD). BASED ON THE FORECAST LOWS AND EXPECTED WINDS LOOKS LIKE NC IL STANDS A REASONABLY GOOD CHANCE OF REACHING THE -20F WIND CHILL ADVISORY CRITERIA AND SO HAVE GONE AHEAD AND ISSUED THAT ALREADY THERE. FOR CHICAGO AREA AND POINTS SOUTH AND EAST IT WILL UNDOUBTEDLY BE VERY COLD TONIGHT BUT APPEARS UNLIKELY THAT THE -20F CRITERIA WILL BE MET FOR ANY LENGTH OF TIME SO KEPT ADVISORY NORTH/WEST OF THESE AREAS. COULD SEE SOME SUNSHINE THE FIRST HALF OF THE DAY ON FRIDAY BUT WILL REMAIN QUITE COLD WITH CLOUDS ROLLING BACK IN IN THE AFTERNOON AS FAST MOVING CLIPPER DIVES SE TOWARD THE AREA. VERY LITTLE CHANGE IN MODEL GUIDANCE IN HANDLING THIS WAVE WITH SWATH OF ACCUMULATING VERY FLUFFIFIED/HIGH RATION SNOW LIKELY ACROSS NORTHERN/CENTRAL ILLINOIS FRIDAY NIGHT INTO SATURDAY MORNING. DESPITE LIMITED MOISTURE...HIGH SNOW:LIQUID RATIOS COULD SUPPORT SOLID 2-3 INCH BAND OF SNOW...WITH BEST PROJECTIONS AT THIS POINT PLACING THE HEAVIEST SNOW ALONG OR SOUTH OF I-80. GIVEN HOW LOW AMPLITUDE THIS WAVE IS WOULD NOT BE A STRETCH TO ENVISION LATER RUNS REFINING THE TRACK A BIT...BUT EVEN WITH THAT IN MIND FELT FAIRLY COMFORTABLE CONTINUING THE TREND OF BUMPING POPS UP A BIT HIGHER AGAIN THIS MORNING. SEEMINGLY NEVER ENDING PARADE OF CLIPPERS ARE PROGGED TO CONTINUE TO PIVOT AROUND THE BASE OF THE TROUGH HEADING INTO NEXT WEEK. THE 00Z ECMWF HAS COME IN A BIT DEEPER AND FARTHER WEST WITH THE POLAR VORTEX OVER THE REGION WHICH WOULD PLACE OUR CWA CLOSER TO THE COLD SIDE OF THE PATH OF THESE CLIPPERS AND ALSO CLOSER TO POTENTIAL LIGHT ACCUMULATING SNOWS. THE GEM...GFS...AND PREVIOUS ECMWF WERE QUICKER TO WEAKEN THE POLAR VORTEX ALLOWING THE CLIPPERS TO PASS TO OUR NORTH KEEPING US DRY WITH ALTERNATING BOUTS OF ABOVE AVERAGE TEMPS AND SLIGHT COOL DOWNS WITH A TREND TOWARD SLIGHTLY WEAKER COOL DOWNS WITH EACH WAVE. CONFIDENCE IS NOT TERRIBLY HIGH IN ANY ONE SOLUTION AT THIS POINT BUT A TOWARD MODERATING TEMPS DEFINITELY LOOKS REASONABLE HEADING INTO NEXT WEEK WITH LESS CERTAINTY REGARDING PRECIP CHANCES. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * W WIND GUSTING 25-30 KT THROUGH THIS EVENING THEN GUSTS 15-20 KT OVERNIGHT. * PERIODS OF -SHSN THROUGH THE EARLY EVENING...HEAVIER BANDS COULD DROP VSBY DOWN TO LESS THAN A MILE. * HIGH END MVFR TO LOW END VFR CIGS EXPECTED THROUGH TONIGHT. JEE //DISCUSSION...UPDATED 18Z... AN UPPER LEVEL SHORT WAVE TROUGH MOVED THROUGH THE DAKOTAS AND PROVIDED FORCING FOR THE BANDS OF SNOW THE AREA SAW EARLIER THIS MORNING. THE SHORTWAVE IS MOVING INTO IA WITH SHSN FORMING OVER SOUTHERN WI. AS SUCH KEPT OCNL FLURRIES IN FOR THE TERMINALS THROUGH 20Z AND EXPECTING MORE SUBSTANTIAL -SHSN AFTER 20Z. THEY COULD DEVELOP A LITTLE LATER THAN INDICATED...WITH ARND A HALF INCH OF SNOW PSBL. THE HEAVIER BANDS IN WI ARE ASSOCIATED WITH VSBY OF LESS THAN 1 MILE...BUT WILL ADDRESS THOSE HEAVIER BANDS AS THEY SET UP. OVERALL THINKING VSBYS WILL BE 4SM OR BETTER. EXPECTING CIGS TO DROP A LITTLE WITH THE SNOW AS WELL TO ARND 020. A FEW UPSTREAM OBS INDICATE 015 CIGS ARE PSBL SO WILL KEEP AN EYE ON HOW THE LOWER CIGS PROGRESS. WINDS WILL REMAIN W GUSTING TO 25 KT THROUGH THE MID AFTN WITH GUSTS INCREASING TO 25-30KT THROUGH THE EVENING. WEST WINDS GUSTING 15-20 KT ARE THEN EXPECTED OVERNIGHT UNDER THE TIGHTENED PRESSURE GRADIENT. HIGH PRESSURE SINKS SOUTH TO THE EAST OF THE TERMINALS ALLOWING SKIES TO SCATTER OUT TOMORROW. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN PRECIP FCST...MEDIUM CONFIDENCE IN TIMING AND VSBY ASSOCIATED WITH -SN/-SHSN. * HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... 12Z... FRIDAY NIGHT...ACCUMULATING SNOW BECOMING LIKELY. MVFR BECOMING IFR. SATURDAY...MVFR WITH A CHANCE OF IFR SNOW SHOWERS...MAINLY IN THE MORNING. SUNDAY...MVFR. MONDAY...VFR. TUESDAY...VFR. WEDNESDAY...VFR. TRS && .MARINE... 446 AM CST DEEP LOW PRESSURE HAS MOVED FROM GEORGIAN BAY INTO SW QUEBEC DURING LATE WED EVENING AND EARLY THIS MORNING AND WILL CONTINUE TO MOVE FURTHER OFF TO THE NE. W TO WNW WINDS HAVE SLACKENED A BIT AS A RESULT OR THE DECREASING PRESSURE GRADIENT OVER LAKE MI THOUGH A FEW COASTAL OBSERVATION SITES ALONG THE IN AND FAR SW LOWER MI SHORED CONTINUED TO MEASURE SOME 35-40KT GALE FORCE GUSTS. WINDS WILL CONTINUE TO GRADUALLY DIMINISH DURING THE PREDAWN AND EARLY MORNING HOURS BUT WILL REMAIN BRISK AS STRONG HIGH PRESSURE CONTINUES TO BUILD SE FROM SOUTHERN SASKATCHEWAN ACROSS THE NORTHERN AND CENTRAL PLAINS TODAY. WINDS WILL INCREASE AND REACH GALES ON THE SOUTH PORTION OF THE LAKE BY MID AFTERNOON AS A SURFACE TROUGH DROPS SE DOWN THE LAKE SPREADING AND ANOTHER SURGE OF COLD AIR OVER THE REGION. GALE FORCE WINDS AND VERY COLD AIR WILL RESULT IN FREEZING SPRAY ACROSS THE LAKE. GALES WILL CONTINUE INTO LATE TONIGHT. BY FRIDAY MORNING A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER IA AND MO. THE PRESSURE GRADIENT DECREASES AS THE CENTER OF THE HIGH MOVES NEARER TO THE AREA AND WINDS ON THE LAKE WILL DIMINISH TO BELOW GALE FORCE BY FRI MORNING. NW WINDS GRADUALLY BACK TO SW DURING FRI AS THE CENTER OF THE HIGH MOVES TO KY AND TN BY LATE IN THE AFTERNOON. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010- ILZ011...MIDNIGHT FRIDAY TO 10 AM FRIDAY. IN...NONE. LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777- LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 6 AM FRIDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM FRIDAY. SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM SATURDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1125 AM CST THU JAN 31 2013 .DISCUSSION... 1016 AM CST FOR MORNING UPDATE... HAVE MADE A FEW ADJUSTMENTS TO NEAR TERM FORECAST THIS MORNING... TO BUMP POPS A BIT FOR OCCASIONAL SNOW SHOWERS. HAVE SEEN SOME ISOLATED VISIBILITY REDUCTIONS LESS THAN A MILE AT TIMES THIS MORNING WITH A FEW PLACES PICKING UP A DUSTING TO A TENTH OF AN INCH OR SO. HAVE ALSO TOUCHED UP SKY COVER GRIDS...ACCOUNT SIGNIFICANT OPEN PATCHES THIS MORNING ACROSS WEST/SOUTH PARTS OF CWA AND CONVECTIVE NATURE OF EXPECTED CLOUD COVER THROUGH THE DAY. MORNING ANALYSIS INDICATES DEEPENING SURFACE LOW CONTINUES TO TRACK AWAY WELL TO OUR NORTHEAST ACROSS SOUTHERN QUEBEC...WITH COLD FRONT TRAILING THROUGH NORTHERN INDIANA/CENTRAL ILLINOIS. COLD ARCTIC AIR CONTINUES TO SPREAD SOUTHEAST ACROSS THE UPPER MIDWEST BEHIND THIS FRONT...WITH SINGLE DIGIT AND SUB-ZERO TEMPS WIDESPREAD TO OUR WEST/NORTHWEST. LOOKING ALOFT...RATHER STRONG MID-LEVEL SHORT WAVE WAS NOTED OVER THE EASTERN DAKOTAS/MINNESOTA...AND THIS WAVE IS PROGGED TO CONTINUE TO MOVE SOUTHEAST ACROSS OUR AREA THROUGH THIS EVENING. SCATTERED SNOW SHOWERS...SOME FAIRLY INTENSE WITH VISIBILITY REDUCTIONS AND BRIEF MINOR ACCUMULATIONS...HAVE BEEN PREVALENT ACROSS NORTHEAST IL THIS MORNING. THESE APPEAR TO BE HIGHLY DRIVEN BY STEEP LOW LEVEL LAPSE RATES AS EVIDENCED BY 12Z ILX RAOB AND RECENT AIRCRAFT AMDAR SOUNDINGS FROM ORD...WHICH DEPICT ADIABATIC LOW LEVEL PROFILES FROM THE SURFACE UP TO ABOUT 850-800 MB. THIS ALSO COINCIDES NICELY WITH THE -12 TO -18C FAVORED TEMPERATURE LAYER FOR GOOD DENDRITIC GROWTH OF ICE CRYSTALS...OF WHICH HAVE BEEN OBSERVED AT TIMES THIS MORNING. FORECAST SOUNDINGS FROM MORNING RUNS OF THE WRF-NAM AND RAP MAINTAIN THESE STEEP LOW LEVEL LAPSE RATES THROUGH THE DAY...COINCIDENT WITH BETTER MID/UPPER LEVEL FORCING ASSOCIATED WITH THE APPROACH AND PASSAGE OF AFOREMENTIONED UPPER MIDWEST SHORT WAVE. DEPSITE DRY ADVECTION OF ARCTIC AIR AND EVEN THOUGH VIS SATELLITE IMAGERY IS NOT TOO IMPRESSIVE WITH CLOUD COVER...SUSPECT THAT THIN STRATOCU WILL CONTINUE TO DEVELOP AND PERHAPS INCREASE IN COVERAGE IN UNSTABLE LOW LEVEL THERMODYNAMIC ENVIRONMENT...AND SHOULD BE ABLE TO SUSTAIN SNOW SHOWERS AND FLURRIES WITH SUFFICIENT INTENSITY AT TIMES TO PRODUCE SOME MINOR ACCUMS IN LOCALIZED AREAS. THEREFORE HAVE BUMPED POPS TO HIGHER CHANCE CATEGORY...AND WORDED OCCASIONAL SNOW SHOWERS/FLURRIES WITH A FEW TENTHS OF AN INCH POSSIBLE FOR MUCH OF NORTHERN 2/3 OR SO OF THE CWA THROUGH THE DAY...AND THIS EVENING. MID-LEVEL TROUGH AXIS MOVES ACROSS THE REGION LATE EVENING/MIDNIGHT TIME FRAME...AFTER WHICH FORECAST SOUNDINGS DEPICT STRENGTHENING/LOWERING SUBSIDENCE INVERSION WHICH SHOULD LIMIT FURTHER MEASURABLE PRECIP THREAT. OTHERWISE...GOING FORECAST LOOKS GOOD THROUGH THIS AFTERNOON WITH TEMPS NOT GOING ANYWHERE...AND COLD...BLUSTERY CONDITIONS. RATZER //PREV DISCUSSION... 340 AM CST PRIMARY FORECAST CHALLENGE THIS MORNING IS CLOUD COVER AND ITS IMPACT ON TEMPS THE NEXT SEVERAL DAYS AS WELL AS FLURRY/LIGHT SNOW CHANCES. PHASE ONE OF ARCTIC AIR HAS MOVED INTO THE AREA WITH PHASE 2 STILL UPSTREAM AND POISED TO ARRIVE THIS AFTERNOON INTO TONIGHT. AS ALLUDED TO LAST NIGHT GUIDANCE HAS BEEN FAR TOO COLD WITH TEMPS OVERNIGHT INTO THE EARLY MORNING HOURS THIS MORNING...RUNNING IN SOME CASES MORE THAN 5F TOO COLD AT 9Z THANKS TO THE CLOUD COVER AND WIND. NO APPRECIABLE CLEARING IS ANTICIPATED PRIOR TO SUNRISE SO A VERY SLOW (1-2F EVERY HOUR OR TWO) FALL SHOULD CONTINUE THROUGH SUNRISE. WITH THE RE-ENFORCING SHOT OF COLD AIR ARRIVING THIS AFTERNOON AND A GOOD DEAL OF CLOUD COVER/GUSTY NORTHWEST WINDS DONT ANTICIPATE TEMPS TO REBOUND MUCH FROM EARLY MORNING READINGS WITH TEMPS FAIRLY STEADY MOST OF THE DAY. ALONG WITH THE ARRIVAL OF THE COLD AIR...WATER VAPOR IMAGERY SHOWS A COUPLE OF VORTS UPSTREAM OVER THE NORTHERN PLAINS THAT WILL PIVOT SOUTHEAST INTO THE AREA THIS AFTERNOON/EVENING. ICE CRYSTALS ARE LIKELY ALREADY PRESENT IN THE STRATUS DECK GIVEN THE ARCTIC TEMPS SO IT WILL REMAIN REMARKABLY EASY FOR LIGHT SNOW OR FLURRIES TO FALL OUT OF THIS STRATUS DECK TODAY INTO TONIGHT...THOUGH ACCUMULATIONS SHOULD BE MINIMAL FLAKES WILL LIKELY BE FLYING AT TIMES TODAY INTO THIS EVENING. CERTAINLY THE AIR MASS ADVECTING INTO THE AREA WILL BE VERY COLD WITH EVENING SOUNDINGS UPSTREAM SAMPLING 850MB TEMPS NEAR -20C...HOWEVER ITS NOT CLEAR HOW MUCH IF ANY CLEARING WILL TAKE PLACE TONIGHT. IN THE ABSENCE OF CLEARING...THE WINDS AND CLOUDS WOULD LIKELY KEEP TEMPS SEVERAL DEGREES WARMER THAN MOS LOWS AND SUSPECT THAT CLOUDS WILL LINGER THROUGH THE NIGHT OVER EASTERN CWA WITH SOME CLEAR LATE WEST. HAVE GENERALLY ADJUSTED LOW TEMPS UPWARD SOME FROM PREVIOUS FORECAST AND GONE A BIT ABOVE THE WARMER MOS GUIDANCE NUMBERS AS MODELS SUGGEST THAT LOW LEVEL CYCLONIC FLOW WILL PERSIST MOST OF THE NIGHT RAISING SERIOUS DOUBTS ABOUT HOW MUCH CLEARING WILL TAKE PLACE. IN ADDITION...THE AIR MASS THIS GO AROUND WILL BE A COUPLE/FEW DEGREES MILDER AT 850MB THAN THE PREVIOUS ONE AND WITH LITTLE/NO SNOW COVER MOST AREAS WOULD EXPECT LOWS TO BOTTOM OUT NO COLDER THAN LAST GO AROUND AND IN ALL LIKELIHOOD A COUPLE DEGREES WARMER (WELL LESS COLD). BASED ON THE FORECAST LOWS AND EXPECTED WINDS LOOKS LIKE NC IL STANDS A REASONABLY GOOD CHANCE OF REACHING THE -20F WIND CHILL ADVISORY CRITERIA AND SO HAVE GONE AHEAD AND ISSUED THAT ALREADY THERE. FOR CHICAGO AREA AND POINTS SOUTH AND EAST IT WILL UNDOUBTEDLY BE VERY COLD TONIGHT BUT APPEARS UNLIKELY THAT THE -20F CRITERIA WILL BE MET FOR ANY LENGTH OF TIME SO KEPT ADVISORY NORTH/WEST OF THESE AREAS. COULD SEE SOME SUNSHINE THE FIRST HALF OF THE DAY ON FRIDAY BUT WILL REMAIN QUITE COLD WITH CLOUDS ROLLING BACK IN IN THE AFTERNOON AS FAST MOVING CLIPPER DIVES SE TOWARD THE AREA. VERY LITTLE CHANGE IN MODEL GUIDANCE IN HANDLING THIS WAVE WITH SWATH OF ACCUMULATING VERY FLUFFIFIED/HIGH RATION SNOW LIKELY ACROSS NORTHERN/CENTRAL ILLINOIS FRIDAY NIGHT INTO SATURDAY MORNING. DESPITE LIMITED MOISTURE...HIGH SNOW:LIQUID RATIOS COULD SUPPORT SOLID 2-3 INCH BAND OF SNOW...WITH BEST PROJECTIONS AT THIS POINT PLACING THE HEAVIEST SNOW ALONG OR SOUTH OF I-80. GIVEN HOW LOW AMPLITUDE THIS WAVE IS WOULD NOT BE A STRETCH TO ENVISION LATER RUNS REFINING THE TRACK A BIT...BUT EVEN WITH THAT IN MIND FELT FAIRLY COMFORTABLE CONTINUING THE TREND OF BUMPING POPS UP A BIT HIGHER AGAIN THIS MORNING. SEEMINGLY NEVER ENDING PARADE OF CLIPPERS ARE PROGGED TO CONTINUE TO PIVOT AROUND THE BASE OF THE TROUGH HEADING INTO NEXT WEEK. THE 00Z ECMWF HAS COME IN A BIT DEEPER AND FARTHER WEST WITH THE POLAR VORTEX OVER THE REGION WHICH WOULD PLACE OUR CWA CLOSER TO THE COLD SIDE OF THE PATH OF THESE CLIPPERS AND ALSO CLOSER TO POTENTIAL LIGHT ACCUMULATING SNOWS. THE GEM...GFS...AND PREVIOUS ECMWF WERE QUICKER TO WEAKEN THE POLAR VORTEX ALLOWING THE CLIPPERS TO PASS TO OUR NORTH KEEPING US DRY WITH ALTERNATING BOUTS OF ABOVE AVERAGE TEMPS AND SLIGHT COOL DOWNS WITH A TREND TOWARD SLIGHTLY WEAKER COOL DOWNS WITH EACH WAVE. CONFIDENCE IS NOT TERRIBLY HIGH IN ANY ONE SOLUTION AT THIS POINT BUT A TOWARD MODERATING TEMPS DEFINITELY LOOKS REASONABLE HEADING INTO NEXT WEEK WITH LESS CERTAINTY REGARDING PRECIP CHANCES. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * W WIND GUSTING 20-25KT THROUGH EARLY AFTERNOON...THEN GUSTING 25-30KT LATE AFTN AND THROUGH THE EVENING. * SCATTERED -SN/FLURRIES PASSING OVER THE TERMINALS THROUGH 20Z THEN A PERIOD OF -SHSN LATE THIS AFTN/EARLY EVENING. * HIGH END MVFR TO LOW END VFR CIGS EXPECTED THROUGH TONIGHT. JEE //DISCUSSION...UPDATED 18Z... AN UPPER LEVEL SHORT WAVE TROUGH MOVED THROUGH THE DAKOTAS AND PROVIDED FORCING FOR THE BANDS OF SNOW THE AREA SAW EARLIER THIS MORNING. THE SHORTWAVE IS MOVING INTO IA WITH SHSN FORMING OVER SOUTHERN WI. AS SUCH KEPT OCNL FLURRIES IN FOR THE TERMINALS THROUGH 20Z AND EXPECTING MORE SUBSTANTIAL -SHSN AFTER 20Z. THEY COULD DEVELOP A LITTLE LATER THAN INDICATED...WITH ARND A HALF INCH OF SNOW PSBL. THE HEAVIER BANDS IN WI ARE ASSOCIATED WITH VSBY OF LESS THAN 1 MILE...BUT WILL ADDRESS THOSE HEAVIER BANDS AS THEY SET UP. OVERALL THINKING VSBYS WILL BE 4SM OR BETTER. EXPECTING CIGS TO DROP A LITTLE WITH THE SNOW AS WELL TO ARND 020. A FEW UPSTREAM OBS INDICATE 015 CIGS ARE PSBL SO WILL KEEP AN EYE ON HOW THE LOWER CIGS PROGRESS. WINDS WILL REMAIN W GUSTING TO 25 KT THROUGH THE MID AFTN WITH GUSTS INCREASING TO 25-30KT THROUGH THE EVENING. WEST WINDS GUSTING 15-20 KT ARE THEN EXPECTED OVERNIGHT UNDER THE TIGHTENED PRESSURE GRADIENT. HIGH PRESSURE SINKS SOUTH TO THE EAST OF THE TERMINALS ALLOWING SKIES TO SCATTER OUT TOMORROW. JEE //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN PRECIP FCST...MEDIUM CONFIDENCE IN TIMING AND VSBY ASSOCIATED WITH -SN/-SHSN. * HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... 12Z... FRIDAY NIGHT...ACCUMULATING SNOW BECOMING LIKELY. MVFR BECOMING IFR. SATURDAY...MVFR WITH A CHANCE OF IFR SNOW SHOWERS...MAINLY IN THE MORNING. SUNDAY...MVFR. MONDAY...VFR. TUESDAY...VFR. WEDNESDAY...VFR. TRS && .MARINE... 446 AM CST DEEP LOW PRESSURE HAS MOVED FROM GEORGIAN BAY INTO SW QUEBEC DURING LATE WED EVENING AND EARLY THIS MORNING AND WILL CONTINUE TO MOVE FURTHER OFF TO THE NE. W TO WNW WINDS HAVE SLACKENED A BIT AS A RESULT OR THE DECREASING PRESSURE GRADIENT OVER LAKE MI THOUGH A FEW COASTAL OBSERVATION SITES ALONG THE IN AND FAR SW LOWER MI SHORED CONTINUED TO MEASURE SOME 35-40KT GALE FORCE GUSTS. WINDS WILL CONTINUE TO GRADUALLY DIMINISH DURING THE PREDAWN AND EARLY MORNING HOURS BUT WILL REMAIN BRISK AS STRONG HIGH PRESSURE CONTINUES TO BUILD SE FROM SOUTHERN SASKATCHEWAN ACROSS THE NORTHERN AND CENTRAL PLAINS TODAY. WINDS WILL INCREASE AND REACH GALES ON THE SOUTH PORTION OF THE LAKE BY MID AFTERNOON AS A SURFACE TROUGH DROPS SE DOWN THE LAKE SPREADING AND ANOTHER SURGE OF COLD AIR OVER THE REGION. GALE FORCE WINDS AND VERY COLD AIR WILL RESULT IN FREEZING SPRAY ACROSS THE LAKE. GALES WILL CONTINUE INTO LATE TONIGHT. BY FRIDAY MORNING A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER IA AND MO. THE PRESSURE GRADIENT DECREASES AS THE CENTER OF THE HIGH MOVES NEARER TO THE AREA AND WINDS ON THE LAKE WILL DIMINISH TO BELOW GALE FORCE BY FRI MORNING. NW WINDS GRADUALLY BACK TO SW DURING FRI AS THE CENTER OF THE HIGH MOVES TO KY AND TN BY LATE IN THE AFTERNOON. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010- ILZ011...MIDNIGHT FRIDAY TO 10 AM FRIDAY. IN...NONE. LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777- LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM THURSDAY TO 6 AM FRIDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM FRIDAY. SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 PM FRIDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1017 AM CST THU JAN 31 2013 .DISCUSSION... 1016 AM CST FOR MORNING UPDATE... HAVE MADE A FEW ADJUSTMENTS TO NEAR TERM FORECAST THIS MORNING... TO BUMP POPS A BIT FOR OCCASIONAL SNOW SHOWERS. HAVE SEEN SOME ISOLATED VISIBILITY REDUCTIONS LESS THAN A MILE AT TIMES THIS MORNING WITH A FEW PLACES PICKING UP A DUSTING TO A TENTH OF AN INCH OR SO. HAVE ALSO TOUCHED UP SKY COVER GRIDS...ACCOUNT SIGNIFICANT OPEN PATCHES THIS MORNING ACROSS WEST/SOUTH PARTS OF CWA AND CONVECTIVE NATURE OF EXPECTED CLOUD COVER THROUGH THE DAY. MORNING ANALYSIS INDICATES DEEPENING SURFACE LOW CONTINUES TO TRACK AWAY WELL TO OUR NORTHEAST ACROSS SOUTHERN QUEBEC...WITH COLD FRONT TRAILING THROUGH NORTHERN INDIANA/CENTRAL ILLINOIS. COLD ARCTIC AIR CONTINUES TO SPREAD SOUTHEAST ACROSS THE UPPER MIDWEST BEHIND THIS FRONT...WITH SINGLE DIGIT AND SUB-ZERO TEMPS WIDESPREAD TO OUR WEST/NORTHWEST. LOOKING ALOFT...RATHER STRONG MID-LEVEL SHORT WAVE WAS NOTED OVER THE EASTERN DAKOTAS/MINNESOTA...AND THIS WAVE IS PROGGED TO CONTINUE TO MOVE SOUTHEAST ACROSS OUR AREA THROUGH THIS EVENING. SCATTERED SNOW SHOWERS...SOME FAIRLY INTENSE WITH VISIBILITY REDUCTIONS AND BRIEF MINOR ACCUMULATIONS...HAVE BEEN PREVALENT ACROSS NORTHEAST IL THIS MORNING. THESE APPEAR TO BE HIGHLY DRIVEN BY STEEP LOW LEVEL LAPSE RATES AS EVIDENCED BY 12Z ILX RAOB AND RECENT AIRCRAFT AMDAR SOUNDINGS FROM ORD...WHICH DEPICT ADIABATIC LOW LEVEL PROFILES FROM THE SURFACE UP TO ABOUT 850-800 MB. THIS ALSO COINCIDES NICELY WITH THE -12 TO -18C FAVORED TEMPERATURE LAYER FOR GOOD DENDRITIC GROWTH OF ICE CRYSTALS...OF WHICH HAVE BEEN OBSERVED AT TIMES THIS MORNING. FORECAST SOUNDINGS FROM MORNING RUNS OF THE WRF-NAM AND RAP MAINTAIN THESE STEEP LOW LEVEL LAPSE RATES THROUGH THE DAY...COINCIDENT WITH BETTER MID/UPPER LEVEL FORCING ASSOCIATED WITH THE APPROACH AND PASSAGE OF AFOREMENTIONED UPPER MIDWEST SHORT WAVE. DEPSITE DRY ADVECTION OF ARCTIC AIR AND EVEN THOUGH VIS SATELLITE IMAGERY IS NOT TOO IMPRESSIVE WITH CLOUD COVER...SUSPECT THAT THIN STRATOCU WILL CONTINUE TO DEVELOP AND PERHAPS INCREASE IN COVERAGE IN UNSTABLE LOW LEVEL THERMODYNAMIC ENVIRONMENT...AND SHOULD BE ABLE TO SUSTAIN SNOW SHOWERS AND FLURRIES WITH SUFFICIENT INTENSITY AT TIMES TO PRODUCE SOME MINOR ACCUMS IN LOCALIZED AREAS. THEREFORE HAVE BUMPED POPS TO HIGHER CHANCE CATEGORY...AND WORDED OCCASIONAL SNOW SHOWERS/FLURRIES WITH A FEW TENTHS OF AN INCH POSSIBLE FOR MUCH OF NORTHERN 2/3 OR SO OF THE CWA THROUGH THE DAY...AND THIS EVENING. MID-LEVEL TROUGH AXIS MOVES ACROSS THE REGION LATE EVENING/MIDNIGHT TIME FRAME...AFTER WHICH FORECAST SOUNDINGS DEPICT STRENGTHENING/LOWERING SUBSIDENCE INVERSION WHICH SHOULD LIMIT FURTHER MEASURABLE PRECIP THREAT. OTHERWISE...GOING FORECAST LOOKS GOOD THROUGH THIS AFTERNOON WITH TEMPS NOT GOING ANYWHERE...AND COLD...BLUSTERY CONDITIONS. RATZER && .PREV DISCUSSION... 340 AM CST PRIMARY FORECAST CHALLENGE THIS MORNING IS CLOUD COVER AND ITS IMPACT ON TEMPS THE NEXT SEVERAL DAYS AS WELL AS FLURRY/LIGHT SNOW CHANCES. PHASE ONE OF ARCTIC AIR HAS MOVED INTO THE AREA WITH PHASE 2 STILL UPSTREAM AND POISED TO ARRIVE THIS AFTERNOON INTO TONIGHT. AS ALLUDED TO LAST NIGHT GUIDANCE HAS BEEN FAR TOO COLD WITH TEMPS OVERNIGHT INTO THE EARLY MORNING HOURS THIS MORNING...RUNNING IN SOME CASES MORE THAN 5F TOO COLD AT 9Z THANKS TO THE CLOUD COVER AND WIND. NO APPRECIABLE CLEARING IS ANTICIPATED PRIOR TO SUNRISE SO A VERY SLOW (1-2F EVERY HOUR OR TWO) FALL SHOULD CONTINUE THROUGH SUNRISE. WITH THE RE-ENFORCING SHOT OF COLD AIR ARRIVING THIS AFTERNOON AND A GOOD DEAL OF CLOUD COVER/GUSTY NORTHWEST WINDS DONT ANTICIPATE TEMPS TO REBOUND MUCH FROM EARLY MORNING READINGS WITH TEMPS FAIRLY STEADY MOST OF THE DAY. ALONG WITH THE ARRIVAL OF THE COLD AIR...WATER VAPOR IMAGERY SHOWS A COUPLE OF VORTS UPSTREAM OVER THE NORTHERN PLAINS THAT WILL PIVOT SOUTHEAST INTO THE AREA THIS AFTERNOON/EVENING. ICE CRYSTALS ARE LIKELY ALREADY PRESENT IN THE STRATUS DECK GIVEN THE ARCTIC TEMPS SO IT WILL REMAIN REMARKABLY EASY FOR LIGHT SNOW OR FLURRIES TO FALL OUT OF THIS STRATUS DECK TODAY INTO TONIGHT...THOUGH ACCUMULATIONS SHOULD BE MINIMAL FLAKES WILL LIKELY BE FLYING AT TIMES TODAY INTO THIS EVENING. CERTAINLY THE AIR MASS ADVECTING INTO THE AREA WILL BE VERY COLD WITH EVENING SOUNDINGS UPSTREAM SAMPLING 850MB TEMPS NEAR -20C...HOWEVER ITS NOT CLEAR HOW MUCH IF ANY CLEARING WILL TAKE PLACE TONIGHT. IN THE ABSENCE OF CLEARING...THE WINDS AND CLOUDS WOULD LIKELY KEEP TEMPS SEVERAL DEGREES WARMER THAN MOS LOWS AND SUSPECT THAT CLOUDS WILL LINGER THROUGH THE NIGHT OVER EASTERN CWA WITH SOME CLEAR LATE WEST. HAVE GENERALLY ADJUSTED LOW TEMPS UPWARD SOME FROM PREVIOUS FORECAST AND GONE A BIT ABOVE THE WARMER MOS GUIDANCE NUMBERS AS MODELS SUGGEST THAT LOW LEVEL CYCLONIC FLOW WILL PERSIST MOST OF THE NIGHT RAISING SERIOUS DOUBTS ABOUT HOW MUCH CLEARING WILL TAKE PLACE. IN ADDITION...THE AIR MASS THIS GO AROUND WILL BE A COUPLE/FEW DEGREES MILDER AT 850MB THAN THE PREVIOUS ONE AND WITH LITTLE/NO SNOW COVER MOST AREAS WOULD EXPECT LOWS TO BOTTOM OUT NO COLDER THAN LAST GO AROUND AND IN ALL LIKELIHOOD A COUPLE DEGREES WARMER (WELL LESS COLD). BASED ON THE FORECAST LOWS AND EXPECTED WINDS LOOKS LIKE NC IL STANDS A REASONABLY GOOD CHANCE OF REACHING THE -20F WIND CHILL ADVISORY CRITERIA AND SO HAVE GONE AHEAD AND ISSUED THAT ALREADY THERE. FOR CHICAGO AREA AND POINTS SOUTH AND EAST IT WILL UNDOUBTEDLY BE VERY COLD TONIGHT BUT APPEARS UNLIKELY THAT THE -20F CRITERIA WILL BE MET FOR ANY LENGTH OF TIME SO KEPT ADVISORY NORTH/WEST OF THESE AREAS. COULD SEE SOME SUNSHINE THE FIRST HALF OF THE DAY ON FRIDAY BUT WILL REMAIN QUITE COLD WITH CLOUDS ROLLING BACK IN IN THE AFTERNOON AS FAST MOVING CLIPPER DIVES SE TOWARD THE AREA. VERY LITTLE CHANGE IN MODEL GUIDANCE IN HANDLING THIS WAVE WITH SWATH OF ACCUMULATING VERY FLUFFIFIED/HIGH RATION SNOW LIKELY ACROSS NORTHERN/CENTRAL ILLINOIS FRIDAY NIGHT INTO SATURDAY MORNING. DESPITE LIMITED MOISTURE...HIGH SNOW:LIQUID RATIOS COULD SUPPORT SOLID 2-3 INCH BAND OF SNOW...WITH BEST PROJECTIONS AT THIS POINT PLACING THE HEAVIEST SNOW ALONG OR SOUTH OF I-80. GIVEN HOW LOW AMPLITUDE THIS WAVE IS WOULD NOT BE A STRETCH TO ENVISION LATER RUNS REFINING THE TRACK A BIT...BUT EVEN WITH THAT IN MIND FELT FAIRLY COMFORTABLE CONTINUING THE TREND OF BUMPING POPS UP A BIT HIGHER AGAIN THIS MORNING. SEEMINGLY NEVER ENDING PARADE OF CLIPPERS ARE PROGGED TO CONTINUE TO PIVOT AROUND THE BASE OF THE TROUGH HEADING INTO NEXT WEEK. THE 00Z ECMWF HAS COME IN A BIT DEEPER AND FARTHER WEST WITH THE POLAR VORTEX OVER THE REGION WHICH WOULD PLACE OUR CWA CLOSER TO THE COLD SIDE OF THE PATH OF THESE CLIPPERS AND ALSO CLOSER TO POTENTIAL LIGHT ACCUMULATING SNOWS. THE GEM...GFS...AND PREVIOUS ECMWF WERE QUICKER TO WEAKEN THE POLAR VORTEX ALLOWING THE CLIPPERS TO PASS TO OUR NORTH KEEPING US DRY WITH ALTERNATING BOUTS OF ABOVE AVERAGE TEMPS AND SLIGHT COOL DOWNS WITH A TREND TOWARD SLIGHTLY WEAKER COOL DOWNS WITH EACH WAVE. CONFIDENCE IS NOT TERRIBLY HIGH IN ANY ONE SOLUTION AT THIS POINT BUT A TOWARD MODERATING TEMPS DEFINITELY LOOKS REASONABLE HEADING INTO NEXT WEEK WITH LESS CERTAINTY REGARDING PRECIP CHANCES. IZZI && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * W WIND GUSTING 20-25KT THROUGH EARLY AFTERNOON...THEN GUSTING 25-30KT LATE AFTN AND THROUGH THE EVENING. * SCATTERED -SN/FLURRIES PASSING OVER THE TERMINALS THROUGH 20Z THEN A PERIOD OF -SHSN LATE THIS AFTN/EARLY EVENING. * HIGH END MVFR TO LOW END VFR CIGS EXPECTED. JEE //DISCUSSION...UPDATED 12Z... ANOTHER MID LEVEL SHORT WAVE TROUGH WAS MOVING OVER NORTHERN WI... CENTRAL MN AND SE ND EARLY THIS MORNING CONTINUING TO GENERATE LIGHT SNOW ACROSS THE AREA. BANDS OF SOMEWHAT HEAVER SNOW OCCASIONALLY PASS OVER ORD AND/OR MDW AND BRIEFLY DROP VISIBILITY DOWN TO 3-5SM. THIS SNOW WILL PERSIST UNTIL THE TROUGH AXIS PASSES BY...WHICH IS EXPECTED IN THE 13Z TO 15Z WINDOW. SOME FLURRIES MAY LINGER THE REST OF THE MORNING BUT WILL NOT BE A RESTRICTION TO VISIBILITY. ANOTHER SHORT WAVE TROUGH...CURRENTLY OVER NORTHERN ND AND MN...WILL CONTINUE TO DROP ESE THIS MORNING AND MOVE TO OVER SE WI...NORTHERN IL AND SOUTHERN IA BY 00Z. SNOWFALL OF ANY SIGNIFICANCE FROM THIS DISTURBANCE IS EXPECTED TO REMAIN MAINLY TO THE NW AND N OF THE CHI AREA WITH JUST MORE FLURRIES...AND POSSIBLY SOME VERY LIGHT SNOW SHOWERS...FOR THE LOCAL AREA DURING THE LATE AFTERNOON AND EARLY EVENING. WINDS SETTLED DOWN DURING THE OVERNIGHT THE TIGHTER PRESSURE GRADIENT SHIFTED E. THE GRADIENT TIGHTENS AGAIN THIS MORNING WITH W-WNW WINDS GUSTING BACK UP INTO 25-30KT RANGE BY LATE MORNING AS THE HIGH PRESSURE RIDGE THAT EXTENDS S ACROSS SW SASKATCHEWAN SE TO THE CENTRAL PLAINS GRADUALLY MOVES SE. WITH THE HIGH CONTINUING TO THE SE THIS EVENING AND OVERNIGHT WINDS WILL DROP OFF AGAIN AS THE GRADIENT ONCE AGAIN RELAXES. MODEL RH FIELDS OF THE LOWER LAYERS SUGGEST THE CURRENT MVFR CEILINGS WILL RISE TO VFR THIS MORNING THEN DROP BACK TO MVFR THIS AFTERNOON. TRS //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN PRECIP FCST...MEDIUM CONFIDENCE IN VSBY ASSOCIATED WITH -SN. * HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... 12Z... FRIDAY NIGHT...ACCUMULATING SNOW BECOMING LIKELY. MVFR BECOMING IFR. SATURDAY...MVFR WITH A CHANCE OF IFR SNOW SHOWERS...MAINLY IN THE MORNING. SUNDAY...MVFR. MONDAY...VFR. TUESDAY...VFR. WEDNESDAY...VFR. TRS && .MARINE... 446 AM CST DEEP LOW PRESSURE HAS MOVED FROM GEORGIAN BAY INTO SW QUEBEC DURING LATE WED EVENING AND EARLY THIS MORNING AND WILL CONTINUE TO MOVE FURTHER OFF TO THE NE. W TO WNW WINDS HAVE SLACKENED A BIT AS A RESULT OR THE DECREASING PRESSURE GRADIENT OVER LAKE MI THOUGH A FEW COASTAL OBSERVATION SITES ALONG THE IN AND FAR SW LOWER MI SHORED CONTINUED TO MEASURE SOME 35-40KT GALE FORCE GUSTS. WINDS WILL CONTINUE TO GRADUALLY DIMINISH DURING THE PREDAWN AND EARLY MORNING HOURS BUT WILL REMAIN BRISK AS STRONG HIGH PRESSURE CONTINUES TO BUILD SE FROM SOUTHERN SASKATCHEWAN ACROSS THE NORTHERN AND CENTRAL PLAINS TODAY. WINDS WILL INCREASE AND REACH GALES ON THE SOUTH PORTION OF THE LAKE BY MID AFTERNOON AS A SURFACE TROUGH DROPS SE DOWN THE LAKE SPREADING AND ANOTHER SURGE OF COLD AIR OVER THE REGION. GALE FORCE WINDS AND VERY COLD AIR WILL RESULT IN FREEZING SPRAY ACROSS THE LAKE. GALES WILL CONTINUE INTO LATE TONIGHT. BY FRIDAY MORNING A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER IA AND MO. THE PRESSURE GRADIENT DECREASES AS THE CENTER OF THE HIGH MOVES NEARER TO THE AREA AND WINDS ON THE LAKE WILL DIMINISH TO BELOW GALE FORCE BY FRI MORNING. NW WINDS GRADUALLY BACK TO SW DURING FRI AS THE CENTER OF THE HIGH MOVES TO KY AND TN BY LATE IN THE AFTERNOON. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010- ILZ011...MIDNIGHT FRIDAY TO 10 AM FRIDAY. IN...NONE. LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777- LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM THURSDAY TO 6 AM FRIDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 10 AM FRIDAY. SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 PM FRIDAY. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1119 AM MST THU JAN 31 2013 .UPDATE... ISSUED AT 1115 AM MST THU JAN 31 2013 UPDATED TEMPERATURES FOR TODAY. COLD AIR IS MAKING ITS IMPACT ESPECIALLY IN THE EASTERN FA WITH MCK TEMPERATURES STEADILY FALLING ABOUT A DEGREE PER HOUR. EXPECT THAT TREND TO WORK ITS WAY SLOWLY WEST ACROSS THE FA. ALSO LOWERED TONIGHT AND FRIDAY TEMPERATURES. && .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 412 AM MST THU JAN 31 2013 FORECAST PROBLEMS WILL PROBLEMATIC TEMPERATURE FORECAST INTO TONIGHT AND HOW MUCH TO WARM UP THE HIGH TEMPERATURES INTO SATURDAY. SATELLITE SHOWING A BROAD UPPER TROUGH OVER THE TROUGH OVER THE WESTERN AND CENTRAL PACIFIC WITH A RIDGE ALONG THE WEST COAST OF NORTH AMERICA. A COUPLE OF SYSTEMS COMING INTO THE RIDGE ARE BEATING IT DOWN. A STRONG AND COLD SYSTEM IS DIGGING INTO THE NORTH CENTRAL PORTION OF THE COUNTRY. VERY COLD AIR MASS HAS MOVED FURTHER SOUTH FROM YESTERDAY AND IS NOT TOO FAR NORTH AND EAST OF OUR AREA. MODELS INITIALIZED WELL AT JET LEVEL WITH THE CANADIAN...GFS...AND NAM DOING THE BEST. MODELS INITIALIZED WELL AT MID LEVELS WITH THE GFS...CANADIAN...AND NAM DOING SLIGHTLY BETTER. LARGER SCALE MODELS DO NOT HAVE THE BACKDOOR COLD FRONT FAR ENOUGH SOUTH AND WEST BY 06Z...OH SURPRISE. THE RUC HAS CONTINUED TO GET BETTER AS THE NIGHT HAS PROGRESSED. OUTSIDE OF THE RUC ON THE LOW LEVEL THERMAL FIELD...THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE UKMET AND NAM. TODAY/TONIGHT...VERY THICK CLOUD COVER HAS SPREAD OVER THE AREA THROUGH THE NIGHT. WHAT THIS HAS DONE HAS PREVENTED ANY FALL OF THE TEMPERATURES AND IN FACT HAS CAUSED THE TEMPERATURES TO RISE SOME. NWP OUTPUT MUST BE UNDERDOING THIS CLOUD COVER AND IS TOO COOL WITH TEMPERATURES. THIS CLOUD COVER IS BEING CAUSED BY STRONG MID TO UPPER LEVEL JET. SOUNDINGS AND PLAN VIEW RELATIVE HUMIDITY PLOTS SHOW THIS CLOUD COVER LASTING MOST OF THE DAY...ESPECIALLY IN THE NORTHEAST PORTION. BACKDOOR COLD FRONT WITH VERY COLD AIR BEHIND IT HAS BEEN MOVING STEADILY TOWARD THE AREA THROUGH THE NIGHT AND IS NOT THAT FAR AWAY. RUC IS CATCHING ONTO THIS AT THIS TIME. INITIALLY WAS GOING TO CUT HIGH TEMPERATURES FROM GOING FORECAST BUT CLOUD COVER HAS COMPLICATED THAT. SO WILL BE STARTING MUCH WARMER THAN WHAT MOST OF THE MODELS SAY. FRONT SAGS ACROSS THE AREA THROUGH THE DAY WITH SOME LOCATIONS IN THE NORTHEAST HALF TO TWO THIRDS REACHING THEIR MAX BY 18Z. SO COMBINING REALITY AND THE RUC ADJUSTED MAX TEMPERATURES UP BUT HAVE EXTREMELY LOW CONFIDENCE ABOUT THIS. DID NOT GOES AS WARM AS IT BECAUSE OF THE CLOUD COVER. HRRR WOULD INDICATE HIGH TEMPERATURES ABOUT 10 DEGREES WARMER IN THE SOUTHWEST PORTION OF THE AREA THAT WHAT I HAVE. LEFT FRONT QUADRANT OF INCOMING JET WILL CONTINUE TO AFFECT THE NORTHEAST HALF TO TWO THIRDS OF THE AREA INTO EARLY AFTERNOON. SEVERAL STATIONS HAVE REPORTED BRIEF PERIODS OF FLURRIES. ALL MODEL OUTPUT AGREES IN PLACING LIGHT QPF IN THE ABOVE MENTIONED AREA. SREF PROBABILITIES AGREE WITH THAT. IT MAKES SENSE WITH THE JET... MESOSCALE FORCING AND LAPSE RATES IN PLACE. HOWEVER...DRIER AIR IN THE LOWEST LAYERS. SO INTRODUCED SCATTERED FLURRIES THROUGH MIDDAY WHEN THE FORCING AND MOISTURE LEAVE. PROBLEMATIC MIN FORECAST AS WELL. WINDS SHIFT AROUND TO A SOUTH DIRECTION PRETTY QUICKLY. NAM IS THE MOST AGGRESSIVE BUT IS SUPPORTED BY OTHER MODEL OUTPUT IN BRINGING STRATUS AND FOG DURING THE LATE EVENING AND OVERNIGHT HOURS. THIS IS AS THE COLD FRONT RETREATS BACK AS A WARM FRONT AND ALL THE MODELS ARE VERY SIMILAR IN DOING IT. MINS WILL PROBABLY BE REACHED IN THE EVENING ESPECIALLY IN THE WEST AND POSSIBLY IN THE SOUTH AND A NON-DIURNAL CURVE WILL HAVE TO BE INTRODUCED. BELIEVE MODELS ARE TOO COOL AND WENT ABOVE THE GUIDANCE. 06Z NAM WAS MUCH MORE ROBUST IN BRINGING IN THE STRATUS AND FOG. NAM HAS BEEN SHOWING THIS FOR A FEW DAYS PLUS THOSE SOUTH WINDS WILL BE BLOWING ACROSS A SNOW FIELD. SO EXPANDED THE PATCHY FOG THAT WAS IN THERE. FRIDAY/FRIDAY NIGHT...STRATUS AND FOG GET PUSHED EAST PRETTY FAST BY THE STRENGTHENING DOWNSLOPE WINDS. THERE MAY BE SOME HIGHER LEVEL CLOUD COVER AROUND. INCOMING SHORTWAVE TROUGH IN NORTHWEST FLOW ALOFT WILL PUSH A WEAK FRONT OR SURFACE TROUGH THROUGH LATER IN THE DAY BUT IT LOOKS LIKE WINDS WILL BE FROM A DOWNSLOPE DIRECTION. SO ENDED UP RAISING THE MAXES A LITTLE. LEFT FRONT QUADRANT OF JET WILL AFFECT THE NORTHERN PORTION OF THE AREA DURING THE NIGHT AS WELL AS THE ABOVE MENTIONED SHORTWAVE TROUGH...WHICH HAPPENS TO BE THE ONE TOPPING THE RIDGE RIGHT NOW NEAR WESTERN CANADA. ALL MODELS AGREE THAT THIS SYSTEM WILL HAVE A VERY STRONG PV ANOMALY AS WELL. MODELS DO NOT SHOW A LOT OF MOISTURE IN THE COLUMN BUT STRENGTH OF SYSTEM SHOULD COMPENSATE FOR THAT. SO EXPANDED THE SPRINKLES AND FLURRIES OVER A LARGER AREA AND THROUGH THE EVENING HOURS. SATURDAY/SATURDAY NIGHT...RIDGING AND DRYING ALOFT PUSH INTO THE AREA FOR SATURDAY. SO WILL HAVE PLENTY OF SUN ALONG WITH STRONG DOWNSLOPE WINDS. SO RAISED MAXES MORE AND I MAY NOT BE WARM ENOUGH AS I BELIEVE MODELS ARE TOO COOL. .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 246 AM MST THU JAN 31 2013 MODEL AGREEMENT IS FAIRLY GOOD IN THE EXTENDED FORECAST. ALL SOLUTIONS ARE POINTING TO A TAME WEATHER PATTERN WITHOUT ANY BIG WEATHER CHANGES OR PRECIPITATION CHANCES. A SYSTEM WILL MOVE ACROSS THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY...BRINGING ONLY A WIND SHIFT AND TEMPERATURES A DEGREE OR TWO COOLER. AFTER THAT...A RIDGE OF HIGH PRESSURE BUILDS BACK IN FROM THE WEST. TEMPERATURES SHOULD BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR THROUGHOUT THE EXTENDED FORECAST. HIGHS SHOULD BE IN THE 50S FOR SUNDAY THROUGH TUESDAY...WITH HIGHS CLIMBING INTO THE 60S BY THE MIDDLE OF NEXT WEEK. GUIDANCE HAS PULLED BACK SOMEWHAT FOR HIGH TEMPERATURES ON SUNDAY BUT STILL THINK TEMPERATURES NEARING 60 FOR EASTERN COLORADO IS NOT OUT OF THE QUESTION. THE ONLY OTHER CONCERN FOR THE EXTENDED FORECAST WAS LOW TEMPERATURES. THE INITIALIZATION PROCEDURE INPUT LOW TEMPERATURES THAT WERE LIKELY TOO WARM. CONSIDERING THE ONGOING DROUGHT CONDITIONS AND MEX AND ECE GUIDANCE SUGGESTING TEMPERATURES MUCH LOWER THAN THE INITIALIZATION...HAVE LOWERED LOW TEMPERATURES A DEGREE OR TWO. GUIDANCE IS ALTERED BY CLIMATOLOGICAL DATA SO THIS COULD BE THE REASON MEX AND ECE GUIDANCE IS BEING HELD DOWN SOMEWHAT. HOWEVER...THE HIGHER LOW TEMPS SEEMED A LITTLE UNREASONABLE WITH CLEAR SKIES AND LIGHT WINDS THROUGHOUT THE EXTENDED PERIOD. THANKS TO ALL FOR THE COLLABORATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1040 AM MST THU JAN 31 2013 VFR TO MVFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT BOTH GLD AND MCK. FOR THE REST OF THE DAY...SOME BREEZY WINDS AND CLEARING SKIES AT GLD...WHILE CURRENT CLOUDS WILL STICK AROUND AT MCK. THIS EVENING A BACKDOOR COLD FRONT WILL PUSH FROM NORTHEAST TO SOUTHWEST...ARRIVING AT MCK AROUND 22Z. THIS WILL SHIFT WINDS...THOUGH WIND SPEEDS AT BOTH TERMINALS WILL BE LIGHT /LESS THAN 10KTS/ THROUGHOUT THE OVERNIGHT PERIOD. SOME PATCHY FOG AND LOW STRATUS CLOUDS ARE EXPECTED...WITH CONDITIONS MAINLY REMAINING MVFR. BEST CHANCE FOR FOG WILL BE AT GLD...THOUGH IF FOG REACHES MCK IT MAY STICK AROUND INTO THE MID-MORNING HOURS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...032 SHORT TERM...BULLER LONG TERM...RRH AVIATION...JJM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1040 AM MST THU JAN 31 2013 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 412 AM MST THU JAN 31 2013 FORECAST PROBLEMS WILL PROBLEMATIC TEMPERATURE FORECAST INTO TONIGHT AND HOW MUCH TO WARM UP THE HIGH TEMPERATURES INTO SATURDAY. SATELLITE SHOWING A BROAD UPPER TROUGH OVER THE TROUGH OVER THE WESTERN AND CENTRAL PACIFIC WITH A RIDGE ALONG THE WEST COAST OF NORTH AMERICA. A COUPLE OF SYSTEMS COMING INTO THE RIDGE ARE BEATING IT DOWN. A STRONG AND COLD SYSTEM IS DIGGING INTO THE NORTH CENTRAL PORTION OF THE COUNTRY. VERY COLD AIR MASS HAS MOVED FURTHER SOUTH FROM YESTERDAY AND IS NOT TOO FAR NORTH AND EAST OF OUR AREA. MODELS INITIALIZED WELL AT JET LEVEL WITH THE CANADIAN...GFS...AND NAM DOING THE BEST. MODELS INITIALIZED WELL AT MID LEVELS WITH THE GFS...CANADIAN...AND NAM DOING SLIGHTLY BETTER. LARGER SCALE MODELS DO NOT HAVE THE BACKDOOR COLD FRONT FAR ENOUGH SOUTH AND WEST BY 06Z...OH SURPRISE. THE RUC HAS CONTINUED TO GET BETTER AS THE NIGHT HAS PROGRESSED. OUTSIDE OF THE RUC ON THE LOW LEVEL THERMAL FIELD...THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE UKMET AND NAM. TODAY/TONIGHT...VERY THICK CLOUD COVER HAS SPREAD OVER THE AREA THROUGH THE NIGHT. WHAT THIS HAS DONE HAS PREVENTED ANY FALL OF THE TEMPERATURES AND IN FACT HAS CAUSED THE TEMPERATURES TO RISE SOME. NWP OUTPUT MUST BE UNDERDOING THIS CLOUD COVER AND IS TOO COOL WITH TEMPERATURES. THIS CLOUD COVER IS BEING CAUSED BY STRONG MID TO UPPER LEVEL JET. SOUNDINGS AND PLAN VIEW RELATIVE HUMIDITY PLOTS SHOW THIS CLOUD COVER LASTING MOST OF THE DAY...ESPECIALLY IN THE NORTHEAST PORTION. BACKDOOR COLD FRONT WITH VERY COLD AIR BEHIND IT HAS BEEN MOVING STEADILY TOWARD THE AREA THROUGH THE NIGHT AND IS NOT THAT FAR AWAY. RUC IS CATCHING ONTO THIS AT THIS TIME. INITIALLY WAS GOING TO CUT HIGH TEMPERATURES FROM GOING FORECAST BUT CLOUD COVER HAS COMPLICATED THAT. SO WILL BE STARTING MUCH WARMER THAN WHAT MOST OF THE MODELS SAY. FRONT SAGS ACROSS THE AREA THROUGH THE DAY WITH SOME LOCATIONS IN THE NORTHEAST HALF TO TWO THIRDS REACHING THEIR MAX BY 18Z. SO COMBINING REALITY AND THE RUC ADJUSTED MAX TEMPERATURES UP BUT HAVE EXTREMELY LOW CONFIDENCE ABOUT THIS. DID NOT GOES AS WARM AS IT BECAUSE OF THE CLOUD COVER. HRRR WOULD INDICATE HIGH TEMPERATURES ABOUT 10 DEGREES WARMER IN THE SOUTHWEST PORTION OF THE AREA THAT WHAT I HAVE. LEFT FRONT QUADRANT OF INCOMING JET WILL CONTINUE TO AFFECT THE NORTHEAST HALF TO TWO THIRDS OF THE AREA INTO EARLY AFTERNOON. SEVERAL STATIONS HAVE REPORTED BRIEF PERIODS OF FLURRIES. ALL MODEL OUTPUT AGREES IN PLACING LIGHT QPF IN THE ABOVE MENTIONED AREA. SREF PROBABILITIES AGREE WITH THAT. IT MAKES SENSE WITH THE JET... MESOSCALE FORCING AND LAPSE RATES IN PLACE. HOWEVER...DRIER AIR IN THE LOWEST LAYERS. SO INTRODUCED SCATTERED FLURRIES THROUGH MIDDAY WHEN THE FORCING AND MOISTURE LEAVE. PROBLEMATIC MIN FORECAST AS WELL. WINDS SHIFT AROUND TO A SOUTH DIRECTION PRETTY QUICKLY. NAM IS THE MOST AGGRESSIVE BUT IS SUPPORTED BY OTHER MODEL OUTPUT IN BRINGING STRATUS AND FOG DURING THE LATE EVENING AND OVERNIGHT HOURS. THIS IS AS THE COLD FRONT RETREATS BACK AS A WARM FRONT AND ALL THE MODELS ARE VERY SIMILAR IN DOING IT. MINS WILL PROBABLY BE REACHED IN THE EVENING ESPECIALLY IN THE WEST AND POSSIBLY IN THE SOUTH AND A NON-DIURNAL CURVE WILL HAVE TO BE INTRODUCED. BELIEVE MODELS ARE TOO COOL AND WENT ABOVE THE GUIDANCE. 06Z NAM WAS MUCH MORE ROBUST IN BRINGING IN THE STRATUS AND FOG. NAM HAS BEEN SHOWING THIS FOR A FEW DAYS PLUS THOSE SOUTH WINDS WILL BE BLOWING ACROSS A SNOW FIELD. SO EXPANDED THE PATCHY FOG THAT WAS IN THERE. FRIDAY/FRIDAY NIGHT...STRATUS AND FOG GET PUSHED EAST PRETTY FAST BY THE STRENGTHENING DOWNSLOPE WINDS. THERE MAY BE SOME HIGHER LEVEL CLOUD COVER AROUND. INCOMING SHORTWAVE TROUGH IN NORTHWEST FLOW ALOFT WILL PUSH A WEAK FRONT OR SURFACE TROUGH THROUGH LATER IN THE DAY BUT IT LOOKS LIKE WINDS WILL BE FROM A DOWNSLOPE DIRECTION. SO ENDED UP RAISING THE MAXES A LITTLE. LEFT FRONT QUADRANT OF JET WILL AFFECT THE NORTHERN PORTION OF THE AREA DURING THE NIGHT AS WELL AS THE ABOVE MENTIONED SHORTWAVE TROUGH...WHICH HAPPENS TO BE THE ONE TOPPING THE RIDGE RIGHT NOW NEAR WESTERN CANADA. ALL MODELS AGREE THAT THIS SYSTEM WILL HAVE A VERY STRONG PV ANOMALY AS WELL. MODELS DO NOT SHOW A LOT OF MOISTURE IN THE COLUMN BUT STRENGTH OF SYSTEM SHOULD COMPENSATE FOR THAT. SO EXPANDED THE SPRINKLES AND FLURRIES OVER A LARGER AREA AND THROUGH THE EVENING HOURS. SATURDAY/SATURDAY NIGHT...RIDGING AND DRYING ALOFT PUSH INTO THE AREA FOR SATURDAY. SO WILL HAVE PLENTY OF SUN ALONG WITH STRONG DOWNSLOPE WINDS. SO RAISED MAXES MORE AND I MAY NOT BE WARM ENOUGH AS I BELIEVE MODELS ARE TOO COOL. .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 246 AM MST THU JAN 31 2013 MODEL AGREEMENT IS FAIRLY GOOD IN THE EXTENDED FORECAST. ALL SOLUTIONS ARE POINTING TO A TAME WEATHER PATTERN WITHOUT ANY BIG WEATHER CHANGES OR PRECIPITATION CHANCES. A SYSTEM WILL MOVE ACROSS THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY...BRINGING ONLY A WIND SHIFT AND TEMPERATURES A DEGREE OR TWO COOLER. AFTER THAT...A RIDGE OF HIGH PRESSURE BUILDS BACK IN FROM THE WEST. TEMPERATURES SHOULD BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR THROUGHOUT THE EXTENDED FORECAST. HIGHS SHOULD BE IN THE 50S FOR SUNDAY THROUGH TUESDAY...WITH HIGHS CLIMBING INTO THE 60S BY THE MIDDLE OF NEXT WEEK. GUIDANCE HAS PULLED BACK SOMEWHAT FOR HIGH TEMPERATURES ON SUNDAY BUT STILL THINK TEMPERATURES NEARING 60 FOR EASTERN COLORADO IS NOT OUT OF THE QUESTION. THE ONLY OTHER CONCERN FOR THE EXTENDED FORECAST WAS LOW TEMPERATURES. THE INITIALIZATION PROCEDURE INPUT LOW TEMPERATURES THAT WERE LIKELY TOO WARM. CONSIDERING THE ONGOING DROUGHT CONDITIONS AND MEX AND ECE GUIDANCE SUGGESTING TEMPERATURES MUCH LOWER THAN THE INITIALIZATION...HAVE LOWERED LOW TEMPERATURES A DEGREE OR TWO. GUIDANCE IS ALTERED BY CLIMATOLOGICAL DATA SO THIS COULD BE THE REASON MEX AND ECE GUIDANCE IS BEING HELD DOWN SOMEWHAT. HOWEVER...THE HIGHER LOW TEMPS SEEMED A LITTLE UNREASONABLE WITH CLEAR SKIES AND LIGHT WINDS THROUGHOUT THE EXTENDED PERIOD. THANKS TO ALL FOR THE COLLABORATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1040 AM MST THU JAN 31 2013 VFR TO MVFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD AT BOTH GLD AND MCK. FOR THE REST OF THE DAY...SOME BREEZY WINDS AND CLEARING SKIES AT GLD...WHILE CURRENT CLOUDS WILL STICK AROUND AT MCK. THIS EVENING A BACKDOOR COLD FRONT WILL PUSH FROM NORTHEAST TO SOUTHWEST...ARRIVING AT MCK AROUND 22Z. THIS WILL SHIFT WINDS...THOUGH WIND SPEEDS AT BOTH TERMINALS WILL BE LIGHT /LESS THAN 10KTS/ THROUGHOUT THE OVERNIGHT PERIOD. SOME PATCHY FOG AND LOW STRATUS CLOUDS ARE EXPECTED...WITH CONDITIONS MAINLY REMAINING MVFR. BEST CHANCE FOR FOG WILL BE AT GLD...THOUGH IF FOG REACHES MCK IT MAY STICK AROUND INTO THE MID-MORNING HOURS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...RRH AVIATION...JJM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
448 AM MST THU JAN 31 2013 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 412 AM MST THU JAN 31 2013 FORECAST PROBLEMS WILL PROBLEMATIC TEMPERATURE FORECAST INTO TONIGHT AND HOW MUCH TO WARM UP THE HIGH TEMPERATURES INTO SATURDAY. SATELLITE SHOWING A BROAD UPPER TROUGH OVER THE TROUGH OVER THE WESTERN AND CENTRAL PACIFIC WITH A RIDGE ALONG THE WEST COAST OF NORTH AMERICA. A COUPLE OF SYSTEMS COMING INTO THE RIDGE ARE BEATING IT DOWN. A STRONG AND COLD SYSTEM IS DIGGING INTO THE NORTH CENTRAL PORTION OF THE COUNTRY. VERY COLD AIR MASS HAS MOVED FURTHER SOUTH FROM YESTERDAY AND IS NOT TOO FAR NORTH AND EAST OF OUR AREA. MODELS INITIALIZED WELL AT JET LEVEL WITH THE CANADIAN...GFS...AND NAM DOING THE BEST. MODELS INITIALIZED WELL AT MID LEVELS WITH THE GFS...CANADIAN...AND NAM DOING SLIGHTLY BETTER. LARGER SCALE MODELS DO NOT HAVE THE BACKDOOR COLD FRONT FAR ENOUGH SOUTH AND WEST BY 06Z...OH SURPRISE. THE RUC HAS CONTINUED TO GET BETTER AS THE NIGHT HAS PROGRESSED. OUTSIDE OF THE RUC ON THE LOW LEVEL THERMAL FIELD...THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE UKMET AND NAM. TODAY/TONIGHT...VERY THICK CLOUD COVER HAS SPREAD OVER THE AREA THROUGH THE NIGHT. WHAT THIS HAS DONE HAS PREVENTED ANY FALL OF THE TEMPERATURES AND IN FACT HAS CAUSED THE TEMPERATURES TO RISE SOME. NWP OUTPUT MUST BE UNDERDOING THIS CLOUD COVER AND IS TOO COOL WITH TEMPERATURES. THIS CLOUD COVER IS BEING CAUSED BY STRONG MID TO UPPER LEVEL JET. SOUNDINGS AND PLAN VIEW RELATIVE HUMIDITY PLOTS SHOW THIS CLOUD COVER LASTING MOST OF THE DAY...ESPECIALLY IN THE NORTHEAST PORTION. BACKDOOR COLD FRONT WITH VERY COLD AIR BEHIND IT HAS BEEN MOVING STEADILY TOWARD THE AREA THROUGH THE NIGHT AND IS NOT THAT FAR AWAY. RUC IS CATCHING ONTO THIS AT THIS TIME. INITIALLY WAS GOING TO CUT HIGH TEMPERATURES FROM GOING FORECAST BUT CLOUD COVER HAS COMPLICATED THAT. SO WILL BE STARTING MUCH WARMER THAN WHAT MOST OF THE MODELS SAY. FRONT SAGS ACROSS THE AREA THROUGH THE DAY WITH SOME LOCATIONS IN THE NORTHEAST HALF TO TWO THIRDS REACHING THEIR MAX BY 18Z. SO COMBINING REALITY AND THE RUC ADJUSTED MAX TEMPERATURES UP BUT HAVE EXTREMELY LOW CONFIDENCE ABOUT THIS. DID NOT GOES AS WARM AS IT BECAUSE OF THE CLOUD COVER. HRRR WOULD INDICATE HIGH TEMPERATURES ABOUT 10 DEGREES WARMER IN THE SOUTHWEST PORTION OF THE AREA THAT WHAT I HAVE. LEFT FRONT QUADRANT OF INCOMING JET WILL CONTINUE TO AFFECT THE NORTHEAST HALF TO TWO THIRDS OF THE AREA INTO EARLY AFTERNOON. SEVERAL STATIONS HAVE REPORTED BRIEF PERIODS OF FLURRIES. ALL MODEL OUTPUT AGREES IN PLACING LIGHT QPF IN THE ABOVE MENTIONED AREA. SREF PROBABILITIES AGREE WITH THAT. IT MAKES SENSE WITH THE JET... MESOSCALE FORCING AND LAPSE RATES IN PLACE. HOWEVER...DRIER AIR IN THE LOWEST LAYERS. SO INTRODUCED SCATTERED FLURRIES THROUGH MIDDAY WHEN THE FORCING AND MOISTURE LEAVE. PROBLEMATIC MIN FORECAST AS WELL. WINDS SHIFT AROUND TO A SOUTH DIRECTION PRETTY QUICKLY. NAM IS THE MOST AGGRESSIVE BUT IS SUPPORTED BY OTHER MODEL OUTPUT IN BRINGING STRATUS AND FOG DURING THE LATE EVENING AND OVERNIGHT HOURS. THIS IS AS THE COLD FRONT RETREATS BACK AS A WARM FRONT AND ALL THE MODELS ARE VERY SIMILAR IN DOING IT. MINS WILL PROBABLY BE REACHED IN THE EVENING ESPECIALLY IN THE WEST AND POSSIBLY IN THE SOUTH AND A NON-DIURNAL CURVE WILL HAVE TO BE INTRODUCED. BELIEVE MODELS ARE TOO COOL AND WENT ABOVE THE GUIDANCE. 06Z NAM WAS MUCH MORE ROBUST IN BRINGING IN THE STRATUS AND FOG. NAM HAS BEEN SHOWING THIS FOR A FEW DAYS PLUS THOSE SOUTH WINDS WILL BE BLOWING ACROSS A SNOW FIELD. SO EXPANDED THE PATCHY FOG THAT WAS IN THERE. FRIDAY/FRIDAY NIGHT...STRATUS AND FOG GET PUSHED EAST PRETTY FAST BY THE STRENGTHENING DOWNSLOPE WINDS. THERE MAY BE SOME HIGHER LEVEL CLOUD COVER AROUND. INCOMING SHORTWAVE TROUGH IN NORTHWEST FLOW ALOFT WILL PUSH A WEAK FRONT OR SURFACE TROUGH THROUGH LATER IN THE DAY BUT IT LOOKS LIKE WINDS WILL BE FROM A DOWNSLOPE DIRECTION. SO ENDED UP RAISING THE MAXES A LITTLE. LEFT FRONT QUADRANT OF JET WILL AFFECT THE NORTHERN PORTION OF THE AREA DURING THE NIGHT AS WELL AS THE ABOVE MENTIONED SHORTWAVE TROUGH...WHICH HAPPENS TO BE THE ONE TOPPING THE RIDGE RIGHT NOW NEAR WESTERN CANADA. ALL MODELS AGREE THAT THIS SYSTEM WILL HAVE A VERY STRONG PV ANOMALY AS WELL. MODELS DO NOT SHOW A LOT OF MOISTURE IN THE COLUMN BUT STRENGTH OF SYSTEM SHOULD COMPENSATE FOR THAT. SO EXPANDED THE SPRINKLES AND FLURRIES OVER A LARGER AREA AND THROUGH THE EVENING HOURS. SATURDAY/SATURDAY NIGHT...RIDGING AND DRYING ALOFT PUSH INTO THE AREA FOR SATURDAY. SO WILL HAVE PLENTY OF SUN ALONG WITH STRONG DOWNSLOPE WINDS. SO RAISED MAXES MORE AND I MAY NOT BE WARM ENOUGH AS I BELIEVE MODELS ARE TOO COOL. .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 246 AM MST THU JAN 31 2013 MODEL AGREEMENT IS FAIRLY GOOD IN THE EXTENDED FORECAST. ALL SOLUTIONS ARE POINTING TO A TAME WEATHER PATTERN WITHOUT ANY BIG WEATHER CHANGES OR PRECIPITATION CHANCES. A SYSTEM WILL MOVE ACROSS THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY...BRINGING ONLY A WIND SHIFT AND TEMPERATURES A DEGREE OR TWO COOLER. AFTER THAT...A RIDGE OF HIGH PRESSURE BUILDS BACK IN FROM THE WEST. TEMPERATURES SHOULD BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR THROUGHOUT THE EXTENDED FORECAST. HIGHS SHOULD BE IN THE 50S FOR SUNDAY THROUGH TUESDAY...WITH HIGHS CLIMBING INTO THE 60S BY THE MIDDLE OF NEXT WEEK. GUIDANCE HAS PULLED BACK SOMEWHAT FOR HIGH TEMPERATURES ON SUNDAY BUT STILL THINK TEMPERATURES NEARING 60 FOR EASTERN COLORADO IS NOT OUT OF THE QUESTION. THE ONLY OTHER CONCERN FOR THE EXTENDED FORECAST WAS LOW TEMPERATURES. THE INITIALIZATION PROCEDURE INPUT LOW TEMPERATURES THAT WERE LIKELY TOO WARM. CONSIDERING THE ONGOING DROUGHT CONDITIONS AND MEX AND ECE GUIDANCE SUGGESTING TEMPERATURES MUCH LOWER THAN THE INITIALIZATION...HAVE LOWERED LOW TEMPERATURES A DEGREE OR TWO. GUIDANCE IS ALTERED BY CLIMATOLOGICAL DATA SO THIS COULD BE THE REASON MEX AND ECE GUIDANCE IS BEING HELD DOWN SOMEWHAT. HOWEVER...THE HIGHER LOW TEMPS SEEMED A LITTLE UNREASONABLE WITH CLEAR SKIES AND LIGHT WINDS THROUGHOUT THE EXTENDED PERIOD. THANKS TO ALL FOR THE COLLABORATION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 444 AM MST THU JAN 31 2013 AT THE BEGINNING OF THE PERIOD...EVEN THOUGH VFR CONDITIONS WILL EXIST...THE LOW AND MID LEVEL CLOUD DECK WILL BE QUITE THICK. SOME FLURRIES WITH LITTLE TO NO VISIBILITY RESTRICTIONS WILL OCCUR...MAINLY AT KGLD. BY LATE MORNING SOME CLEARING WILL OCCUR NEAR KGLD. THE WIND WILL BECOME BRIEFY GUSTY BEFORE DECREASING AND SHIFTING TO AN EASTERLY DIRECTION AS A BACKDOOR COLD FRONT PUSHES ACROSS THE AREA. DURING THE NIGHT THE LOW LEVELS WILL BECOME MORE MOIST AS SOUTH TO SOUTHEAST WINDS ADVECT THE MOISTURE IN. MVFR TO NEAR IFR CONDITIONS WILL OCCUR WHEN THIS BEGINS. THESE CONDITIONS WILL LAST LONGER AT KMCK THAN AT KGLD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...RRH AVIATION...BULLER
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
533 AM CST THU JAN 31 2013 ...UPDATED FOR AVIATION... .SYNOPSIS... ISSUED AT 349 AM CST THU JAN 31 2013 THE 00Z UPPER AIR ANALYSES SHOWED ONE MAJOR SHORTWAVE TROUGH MOVING EASTWARD ACROSS ILLINOIS AND MISSOURI WHILE ANOTHER SHORTWAVE TROUGH WAS JUST UPSTREAM OVER NORTH DAKOTA PROGRESSING SOUTHEASTWARD. A LEAD ARCTIC FRONT WITH THE 1ST SHORTWAVE TROUGH HAD STALLED ACROSS WESTERN KANSAS AND SOUTHWESTERLY DOWNSLOPE WINDS WERE ACTUALLY PUSHING THE FRONT BACK TO THE NORTHEAST AS A WARM FRONT. IN FACT, TEMPERATURES AS OF 3 AM WERE IN THE LOWER 30S AT PLACES LIKE MCCOOK AND OGALLALA, NE AND GOODLAND, WHICH IS VERY BALMY FOR THIS TIME OF MORNING IN JANUARY. MID LEVEL CLOUD WAS PROGRESSING SOUTHWARD INTO NORTHWESTERN KANSAS. THE NEXT ARCTIC FRONT WAS SLOWLY EDGING SOUTHWARD INTO SOUTHERN SOUTH DAKOTA AND TEMPERATURES WERE WELL BELOW ZERO BEHIND THIS FRONT. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 349 AM CST THU JAN 31 2013 AS THE 2ND SHORTWAVE TROUGH MOVES SOUTHEAST TODAY, THE ASSOCIATED REINFORCING ARCTIC FRONT WILL PROGRESS SOUTHWARD INTO CENTRAL AND NORTHERN KANSAS LATE THIS MORNING, AND THEN SOUTHWESTWARD IN BACK DOOR FASHION INTO DODGE CITY AND PRATT BY THIS EVENING. THERE ARE SEVERAL COMPLICATING FACTORS FOR HIGH TEMPERATURES TODAY, INCLUDING PERSISTENCE OF SNOW COVER FROM GARDEN CITY TO DODGE CITY TO HAYS, DOWNSLOPE WARMING AHEAD OF THE FRONT, FRONTAL TIMING, AND THE AMOUNT OF MID LEVEL CLOUD COVER. TEMPERATURES WILL BE TRICKIEST AROUND HAYS AND STAFFORD WHERE IT IS NOT CLEAR IF THE ARCTIC AIR WILL ARRIVE BEFORE DAYTIME HEATING OCCURS. UPON COORDINATION, IT WAS DECIDED TO GO WITH MID 30S AT HAYS FOR AN EARLY HIGH AROUND 18-19Z, WITH FALLING TEMPERATURES THEREAFTER. WARMER 40S TO NEAR 50 DEGREES SEEMS REASONABLE FURTHER SOUTHWEST, WITH THE WARMEST READINGS IN PLACES WITH NO SNOW COVER INCLUDING SYRACUSE, LIBERAL AND MEDICINE LODGE. ALTHOUGH DODGE CITY, GARDEN CITY, JETMORE AND NESS CITY WILL BE IN THE WARM SECTOR ALL DAY, SNOW COVER WILL BE SLOW TO MELT, RESULTING IN HIGHS ONLY IN THE LOWER 40S BEFORE THE FRONT ARRIVES. HOWEVER, IF SNOW COVER IS MORE RAPID THAN EXPECTED, THEN HIGHS COULD REACH INTO THE MID 40S. BY TONIGHT, SURFACE LEE TROUGHING WILL DEVELOP AHEAD OF THE NEXT SHORTWAVE TROUGH APPROACHING THE NORTHERN ROCKIES AS THE MID LEVEL FLOW GAINS A SLIGHT DOWNSLOPE COMPONENT ACROSS THE CENTRAL ROCKIES. THIS WILL RESULT IN A RETURN TO SOUTH WINDS BY MIDNIGHT SO THAT TEMPERATURES MAY ACTUALLY REACH LOWS AROUND MIDNIGHT AND THEN HOLD STEADY OR SLOWLY RISE THEREAFTER. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 252 AM CST THU JAN 31 2013 LONG RANGE MODELS SHOW A TRANQUIL WEATHER PATTERN WITH DRY NORTHWEST UPPER LEVEL FLOW, A FEW MINOR UPPER LEVEL SHORTWAVE TROUGHS, AND WEAK CANADIAN COLD FRONTS. THE FIRST WAVE MOVES ACROSS THE CENTRAL PLAINS ON FRIDAY NIGHT WITH WINDS SHIFTING FROM SOUTH TO NORTH OVERNIGHT AND A WEAK COLD FRONT. THE NEXT UPPER LEVEL WAVE COMES ACROSS THE PLAINS FROM THE PACIFIC NORTHWEST ON SUNDAY NIGHT BUT THIS SYSTEM IS FAIRLY DRY. A STRONGER UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS ON TUESDAY MORNING WITH THE MAIN UPPER JET STAYING WELL NORTH OF THE CENTRAL PLAINS. THE COLD AIR ASSOCIATED WITH THIS WAVE STAYS INTO THE UPPER MIDWEST. AFTER THE WAVE MOVES EAST INTO TUESDAY AND WEDNESDAY A WARMER AIRMASS MOVES INTO THE WESTERN HIGH PLAINS. OVERNIGHT LOWS ARE EXPECTED TO WARM FROM THE MID 20S FRIDAY NIGHT AND SATURDAY NIGHT TO THE 30S INTO WEDNESDAY NIGHT. DAYTIME HIGHS WARM FROM AROUND 50 ON FRIDAY TO THE MID AND UPPER 50S INTO WEDNESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 523 AM CST THU JAN 31 2013 A BACKDOOR ARCTIC COLD FRONT IS FORECAST TO MOVE SOUTHWESTWARD AND INTO WESTERN KANSAS THIS AFTERNOON WITH SOME LOW STRATUS DEVELOPING. AHEAD OF THE FRONT EXPECT MID LEVEL CLOUDINESS. SOUTHWEST TO NORTHWEST WINDS BECOME NORTHEAST TO EASTERLY WITH THE ARCTIC BOUNDARY WITH IFR CONDITIONS DEVELOPING. THE ARCTIC FRONT MAY COME A BIT FASTER THAN HRRR AND THE RAP MODELS FORECAST. FOR NOW WILL HAVE THE ARCTIC FRONT MOVING THROUGH KHYS BY AROUND 19Z, KDDC BY 23Z, AND KGCK BY 02Z. STRATUS MAY THEN ERODE IN THE KHYS AREA AFTER 03Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 40 17 49 24 / 0 0 0 0 GCK 43 18 51 24 / 0 0 0 0 EHA 51 22 55 25 / 0 0 0 0 LBL 50 21 53 24 / 0 0 0 0 HYS 34 12 44 22 / 0 0 0 0 P28 47 15 46 26 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FINCH SHORT TERM...FINCH LONG TERM...KRUSE AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
412 AM MST THU JAN 31 2013 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 412 AM MST THU JAN 31 2013 FORECAST PROBLEMS WILL PROBLEMATIC TEMPERATURE FORECAST INTO TONIGHT AND HOW MUCH TO WARM UP THE HIGH TEMPERATURES INTO SATURDAY. SATELLITE SHOWING A BROAD UPPER TROUGH OVER THE TROUGH OVER THE WESTERN AND CENTRAL PACIFIC WITH A RIDGE ALONG THE WEST COAST OF NORTH AMERICA. A COUPLE OF SYSTEMS COMING INTO THE RIDGE ARE BEATING IT DOWN. A STRONG AND COLD SYSTEM IS DIGGING INTO THE NORTH CENTRAL PORTION OF THE COUNTRY. VERY COLD AIR MASS HAS MOVED FURTHER SOUTH FROM YESTERDAY AND IS NOT TOO FAR NORTH AND EAST OF OUR AREA. MODELS INITIALIZED WELL AT JET LEVEL WITH THE CANADIAN...GFS...AND NAM DOING THE BEST. MODELS INITIALIZED WELL AT MID LEVELS WITH THE GFS...CANADIAN...AND NAM DOING SLIGHTLY BETTER. LARGER SCALE MODELS DO NOT HAVE THE BACKDOOR COLD FRONT FAR ENOUGH SOUTH AND WEST BY 06Z...OH SURPRISE. THE RUC HAS CONTINUED TO GET BETTER AS THE NIGHT HAS PROGRESSED. OUTSIDE OF THE RUC ON THE LOW LEVEL THERMAL FIELD...THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE UKMET AND NAM. TODAY/TONIGHT...VERY THICK CLOUD COVER HAS SPREAD OVER THE AREA THROUGH THE NIGHT. WHAT THIS HAS DONE HAS PREVENTED ANY FALL OF THE TEMPERATURES AND IN FACT HAS CAUSED THE TEMPERATURES TO RISE SOME. NWP OUTPUT MUST BE UNDERDOING THIS CLOUD COVER AND IS TOO COOL WITH TEMPERATURES. THIS CLOUD COVER IS BEING CAUSED BY STRONG MID TO UPPER LEVEL JET. SOUNDINGS AND PLAN VIEW RELATIVE HUMIDITY PLOTS SHOW THIS CLOUD COVER LASTING MOST OF THE DAY...ESPECIALLY IN THE NORTHEAST PORTION. BACKDOOR COLD FRONT WITH VERY COLD AIR BEHIND IT HAS BEEN MOVING STEADILY TOWARD THE AREA THROUGH THE NIGHT AND IS NOT THAT FAR AWAY. RUC IS CATCHING ONTO THIS AT THIS TIME. INITIALLY WAS GOING TO CUT HIGH TEMPERATURES FROM GOING FORECAST BUT CLOUD COVER HAS COMPLICATED THAT. SO WILL BE STARTING MUCH WARMER THAN WHAT MOST OF THE MODELS SAY. FRONT SAGS ACROSS THE AREA THROUGH THE DAY WITH SOME LOCATIONS IN THE NORTHEAST HALF TO TWO THIRDS REACHING THEIR MAX BY 18Z. SO COMBINING REALITY AND THE RUC ADJUSTED MAX TEMPERATURES UP BUT HAVE EXTREMELY LOW CONFIDENCE ABOUT THIS. DID NOT GOES AS WARM AS IT BECAUSE OF THE CLOUD COVER. HRRR WOULD INDICATE HIGH TEMPERATURES ABOUT 10 DEGREES WARMER IN THE SOUTHWEST PORTION OF THE AREA THAT WHAT I HAVE. LEFT FRONT QUADRANT OF INCOMING JET WILL CONTINUE TO AFFECT THE NORTHEAST HALF TO TWO THIRDS OF THE AREA INTO EARLY AFTERNOON. SEVERAL STATIONS HAVE REPORTED BRIEF PERIODS OF FLURRIES. ALL MODEL OUTPUT AGREES IN PLACING LIGHT QPF IN THE ABOVE MENTIONED AREA. SREF PROBABILITIES AGREE WITH THAT. IT MAKES SENSE WITH THE JET... MESOSCALE FORCING AND LAPSE RATES IN PLACE. HOWEVER...DRIER AIR IN THE LOWEST LAYERS. SO INTRODUCED SCATTERED FLURRIES THROUGH MIDDAY WHEN THE FORCING AND MOISTURE LEAVE. PROBLEMATIC MIN FORECAST AS WELL. WINDS SHIFT AROUND TO A SOUTH DIRECTION PRETTY QUICKLY. NAM IS THE MOST AGGRESSIVE BUT IS SUPPORTED BY OTHER MODEL OUTPUT IN BRINGING STRATUS AND FOG DURING THE LATE EVENING AND OVERNIGHT HOURS. THIS IS AS THE COLD FRONT RETREATS BACK AS A WARM FRONT AND ALL THE MODELS ARE VERY SIMILAR IN DOING IT. MINS WILL PROBABLY BE REACHED IN THE EVENING ESPECIALLY IN THE WEST AND POSSIBLY IN THE SOUTH AND A NON-DIURNAL CURVE WILL HAVE TO BE INTRODUCED. BELIEVE MODELS ARE TOO COOL AND WENT ABOVE THE GUIDANCE. 06Z NAM WAS MUCH MORE ROBUST IN BRINGING IN THE STRATUS AND FOG. NAM HAS BEEN SHOWING THIS FOR A FEW DAYS PLUS THOSE SOUTH WINDS WILL BE BLOWING ACROSS A SNOW FIELD. SO EXPANDED THE PATCHY FOG THAT WAS IN THERE. FRIDAY/FRIDAY NIGHT...STRATUS AND FOG GET PUSHED EAST PRETTY FAST BY THE STRENGTHENING DOWNSLOPE WINDS. THERE MAY BE SOME HIGHER LEVEL CLOUD COVER AROUND. INCOMING SHORTWAVE TROUGH IN NORTHWEST FLOW ALOFT WILL PUSH A WEAK FRONT OR SURFACE TROUGH THROUGH LATER IN THE DAY BUT IT LOOKS LIKE WINDS WILL BE FROM A DOWNSLOPE DIRECTION. SO ENDED UP RAISING THE MAXES A LITTLE. LEFT FRONT QUADRANT OF JET WILL AFFECT THE NORTHERN PORTION OF THE AREA DURING THE NIGHT AS WELL AS THE ABOVE MENTIONED SHORTWAVE TROUGH...WHICH HAPPENS TO BE THE ONE TOPPING THE RIDGE RIGHT NOW NEAR WESTERN CANADA. ALL MODELS AGREE THAT THIS SYSTEM WILL HAVE A VERY STRONG PV ANOMALY AS WELL. MODELS DO NOT SHOW A LOT OF MOISTURE IN THE COLUMN BUT STRENGTH OF SYSTEM SHOULD COMPENSATE FOR THAT. SO EXPANDED THE SPRINKLES AND FLURRIES OVER A LARGER AREA AND THROUGH THE EVENING HOURS. SATURDAY/SATURDAY NIGHT...RIDGING AND DRYING ALOFT PUSH INTO THE AREA FOR SATURDAY. SO WILL HAVE PLENTY OF SUN ALONG WITH STRONG DOWNSLOPE WINDS. SO RAISED MAXES MORE AND I MAY NOT BE WARM ENOUGH AS I BELIEVE MODELS ARE TOO COOL. .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 246 AM MST THU JAN 31 2013 MODEL AGREEMENT IS FAIRLY GOOD IN THE EXTENDED FORECAST. ALL SOLUTIONS ARE POINTING TO A TAME WEATHER PATTERN WITHOUT ANY BIG WEATHER CHANGES OR PRECIPITATION CHANCES. A SYSTEM WILL MOVE ACROSS THE NORTHERN PLAINS AND GREAT LAKES ON MONDAY...BRINGING ONLY A WIND SHIFT AND TEMPERATURES A DEGREE OR TWO COOLER. AFTER THAT...A RIDGE OF HIGH PRESSURE BUILDS BACK IN FROM THE WEST. TEMPERATURES SHOULD BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR THROUGHOUT THE EXTENDED FORECAST. HIGHS SHOULD BE IN THE 50S FOR SUNDAY THROUGH TUESDAY...WITH HIGHS CLIMBING INTO THE 60S BY THE MIDDLE OF NEXT WEEK. GUIDANCE HAS PULLED BACK SOMEWHAT FOR HIGH TEMPERATURES ON SUNDAY BUT STILL THINK TEMPERATURES NEARING 60 FOR EASTERN COLORADO IS NOT OUT OF THE QUESTION. THE ONLY OTHER CONCERN FOR THE EXTENDED FORECAST WAS LOW TEMPERATURES. THE INITIALIZATION PROCEDURE INPUT LOW TEMPERATURES THAT WERE LIKELY TOO WARM. CONSIDERING THE ONGOING DROUGHT CONDITIONS AND MEX AND ECE GUIDANCE SUGGESTING TEMPERATURES MUCH LOWER THAN THE INITIALIZATION...HAVE LOWERED LOW TEMPERATURES A DEGREE OR TWO. GUIDANCE IS ALTERED BY CLIMATOLOGICAL DATA SO THIS COULD BE THE REASON MEX AND ECE GUIDANCE IS BEING HELD DOWN SOMEWHAT. HOWEVER...THE HIGHER LOW TEMPS SEEMED A LITTLE UNREASONABLE WITH CLEAR SKIES AND LIGHT WINDS THROUGHOUT THE EXTENDED PERIOD. THANKS TO ALL FOR THE COLLABORATION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1048 PM MST WED JAN 30 2013 VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. LIGHT WESTERLY WINDS WILL TURN NORTHWEST AND BECOME GUSTY AFTER 16Z...BECOMING LIGHT AGAIN FOLLOWING SUNSET AFTER 00Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...RRH AVIATION...JSL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
339 PM CST THU JAN 31 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 315 PM CST THU JAN 31 2013 A STRONG ARCTIC FRONT IS COMBINING WITH AN UPPER LEVEL IMPULSE SHOOTING QUICKLY EASTWARD TOWARDS THE REGION TO PRODUCE BANDS OF LOCALLY HEAVY SNOWS ACROSS MISSOURI THIS AFTERNOON. MESO MODELS...ESP THE RUC...AS WELL THE 12Z GFS TO A LESSER EXTENT ARE CATCHING ONTO THIS. THE RUC BRINGS THE BANDING PRECIP...WHICH MAY BEGIN BRIEFLY AS LIGHT RAIN...INTO SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS DURING THE MID TO LATE AFTERNOON HOURS IN THE POST FRONTAL ENVIRONMENT. THIS SNOW COULD QUICKLY BECOME HEAVY AT TIMES IN E TO W ORIENTED BANDS ACROSS THE REGION. THIS AREA OF PRECIPITATION WILL RAPIDLY MOVE EAST INTO ACROSS THE REMAINDER OF THE REGION EARLY TONIGHT. THE SNOW WILL LIKELY TAPER OFF JUST AS QUICKLY AS IT BEGAN OVER SOUTHEAST MISSOURI EARLY TONIGHT...THEN END OVER THE REST OF THE REGION BY AROUND MIDNIGHT AS THE IMPULSE TRAVELS OFF TO THE EAST ON THE NORTH SIDE OF THE COLD FRONT. THE MAIN IMPACT WILL COME WITH BURSTS OF LOCALLY HEAVY SNOW IN EAST TO WEST BANDING PRECIPITATION. WHERE...AND HOW NARROW OR THICK THESE BANDS OF SNOW BECOME WILL DETERMINE HOW MUCH SNOW A GIVEN LOCATION RECEIVES. AT THIS TIME...IT SEEMS LIKE MUCH OF THE ADVISORY AREA WILL SEE UP TO A QUICK INCH OR SO OF SNOW. HOWEVER...THERE WILL LIKELY BE LOCALLY HEAVIER BANDS THAT PRODUCE A QUICK 2 TO 3 INCHES OF SNOW. MOTORISTS SHOULD BE PREPARED FOR RAPIDLY FLUCTUATING VISIBILITIES TO UNDER A QUARTER MILE AT TIMES. OTHER IMPACTS INCLUDE THE FACT THAT MUCH OF THE SNOW WILL OCCUR DURING INCREASED TRAFFIC BETWEEN 4 PM AND 7 PM...ESPECIALLY IN SOUTHEAST MISSOURI...SOUTHERN ILLINOIS AND THE WESTERN TIP OF KENTUCKY AND SOUTHWEST INDIANA. TRUE ARCTIC BLAST...THOUGH FAIRLY BRIEF...WILL FOLLOW QUICKLY IN THE WAKE OF THIS SYSTEM. SHOULD SEE TEMPS STAY BELOW FREEZING ALL DAY FRIDAY...WELL BELOW FREEZING IF WE GET A FRESH LAYER OF SNOWFALL. SAME WITH FRI NIGHT. IF ANY SNOW IS ON THE GROUND...TEMPS WILL LIKELY CHALLENGE SINGLE DIGITS IN THOSE LOCATIONS. WEAK DISTURBANCE AND WARM FRONT WILL LIKE PASS NEAR THE REGION SAT. RIGHT NOW LOOKS LIKE A NON EVENT...UNLESS THE VERY LIGHT PRECIP BEGINS EARLY ENOUGH SAT AM. IF SO...THEN A LITTLE LIGHT SNOW...SLEET OF FREEZING RAIN WOULD BE POSSIBLE BEFORE SFC TEMPS WARM ABOVE FREEZING. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 315 PM CST THU JAN 31 2013 A FAIRLY ACTIVE PATTERN SETTING UP FOR NEXT WEEK...WITH SEVERAL WEATHER SYSTEMS TO KEEP AN EYE ON. HOWEVER...THEY ARE WEAK SYSTEMS...EXCEPT FOR THE ONE SLATED FOR WED NIGHT/THURSDAY...WHICH HAS THE BEST POTENTIAL RIGHT NOW OF BRINGING MORE WIDESPREAD PRECIPITATION. ON SUNDAY...WE SHOULD SEE SFC HIGH PRESSURE SLOWLY OOZE INTO THE REGION...WITH NORTHWEST FLOW ALOFT. MODELS DIVERGE AFTER THIS...AS THE 00Z ECMWF SHOVES THE SFC HIGH EAST SUNDAY NIGHT AS ANOTHER FRONTAL SYSTEM BARRELS DOWN FROM THE NORTHWEST. A WEAK WAVE ALOFT ACCOMPANIES THIS FEATURE BUT MOST OF THE ENERGY STAYS TO OUR SOUTHWEST. THE 06Z ECMWF SHOWED A GLANCING SHOT FOR PRECIP ACROSS SE MO/SW KY ON MONDAY...BUT THE 12Z RUN IS MUCH MORE AGGRESSIVE AND PAINTS QPF OVER THE ENTIRE AREA. THE GFS IS MUCH SLOWER WITH THE PROGRESSION OF THIS SYSTEM WITH ITS 06Z RUN...AND SHOWS THE SFC HIGH RETREATING MONDAY MORNING WITH THE FRONTAL SYSTEM APPROACHING LATER IN THE DAY...BUT WEAKENING SO MUCH THAT IT REALLY HAS LITTLE IMPACT ON OUR AREA. THE 12Z GFS RUN IS MORE IN LINE WITH THE TIMING OF THE 00Z ECMWF NOW...BUT STILL SPLITS OUR AREA WHEN IT COMES TO RAIN CHANCES...WITH THE MAIN PRECIP SKIRTING BY TO OUR NORTH AND SOUTH. WILL START OUT WITH A SLIGHT CHANCE ACROSS SOUTHERN MO AND SW KY. ANOTHER LOW PRESSURE SYSTEM COMES DOWN OUT OF THE NORTHERN PLAINS AND INTO THE MIDWEST LATE MONDAY NIGHT AND INTO TUESDAY. AGAIN...MODELS DO NOT AGREE ON THIS SYSTEM EITHER...WITH THE ECMWF MUCH DEEPER WITH THE UPPER TROUGH AND HENCE...IT INDICATES THAT SOME PRECIP CHANCES MAY FLIRT WITH THE WABASH VALLEY OF SE IL AND THE EVV TRI STATE REGION ON TUESDAY. SO EITHER WAY...IT DOES NOT LOOK LIKE TOO BIG A DEAL SINCE MOST OF THE MOISTURE STAYS FURTHER NORTH AND EAST OF THE AREA. MODEL SOUNDINGS INDICATE THAT THE LOWEST FEW THOUSAND FT WILL BE WARM ENOUGH THAT EVEN IF IT DID PRECIPITATE...IT SHOULD BE LIQUID. BUT THERE IS QUITE A DIFFERENCE IN LOW LEVEL TEMPS BTWN THE GFS AND ECWMF DUE TO THE DEGREE OF THE AMPLITUDE OF THE TROUGH COMING THROUGH. TUESDAY NIGHT AND WEDNESDAY...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...BUT WILL QUICKLY MOVE EAST WED NIGHT. OUR NEXT SYSTEM COULD IMPACT US AS EARLY AS LATE WED...OR HOLD OFF UNTIL THURSDAY. HOWEVER...THE SIGNAL IS FAIRLY STRONG THAT WE WILL SEE SOME PRECIPITATION ON THURSDAY...WITH SUPPORT OF THE GFS ENSEMBLES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1122 AM CST THU JAN 31 2013 BKN VFR DECK AT KEVV/KOWB ALONG WITH SOME MID CLOUDS AROUND. SCT TO MID CLOUDS POSSIBLE ELSEWHERE AS WELL. ARCTIC COLD FRONT OFF TO THE NORTHWEST WILL MOVE INTO THE AREA LATER THIS AFTERNOON. GUSTY WSW WINDS AHEAD OF IT. HAVE A -SN CHANCE FROM 21Z- 01Z WITH THE FRONTAL PASSAGE. CLEARING AFTER THAT...WITH GUSTY NW WINDS POST FRONTAL...WHICH WILL SLACKEN BY 12Z. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR ILZ081>094. MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MOZ076- 086-087-100-107>112-114. IN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR INZ081- 082-085>088. KY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR KYZ001>022. && $$ SHORT TERM...MEFFERT LONG TERM....CW AVIATION...CW
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1028 PM EST FRI FEB 1 2013 .SYNOPSIS... A COLD NIGHT CAN BE EXPECTED WITH WIND CHILLS BELOW ZERO. A SERIES OF WEATHER SYSTEMS WILL BRING PERIODS OF ACCUMULATING SNOW FOR THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... A LATE EVENING UPDATE HAS BEEN ISSUED TO ACCOUNT FOR THE LATEST TRENDS IN SKY COVERAGE WITH THE FORECAST AREA BISECTED BY AN AREA OF CLEARING. TEMPS AND WINDS WERE ALSO UPDATED TO ACCOUNT FOR THE LATEST TRENDS WITH VALUES NEAR WIND CHILL ADVISORY CRITERIA ACROSS THE HIGHER ELEVATIONS OF THE LAUREL HIGHLANDS/ALLEGHENY FRONT IN WV/MD/PA. THE REST OF THE PREVIOUS DISCUSSION REMAINS THE SAME. THE LATEST RAP MID-LEVEL ANALYSIS INDICATES AN INITIAL SHORT WAVE TROUGH PUSHING OFF THE MID-ATLANTIC COAST...WITH LINGERING VORT ENERGY ON THE LEE SIDE OF THIS FEATURE PROVIDING ENOUGH FORCING FOR A FEW FLURRIES IN WESTERN PA. AT 850MB...TEMPS RANGE FROM -10C TO -16C ACROSS THE AREA TONIGHT...WITH A WEST-NORTHWESTERLY FLOW CONTINUING OFF OF LAKE ERIE. AT THE SURFACE...A 1032MB HIGH IS CENTERED ACROSS THE TENNESSEE VALLEY AND IS EDGING EAST- NORTHEASTWARD TOWARD THE AREA. YET...THE PRESSURE GRADIENT BETWEEN THE HIGH AND A SURFACE LOW WELL NORTH OF THE REGION IS ALLOWING FOR 5-10KT SOUTHWESTERLY WINDS ACROSS THE LOWLANDS AND 10-15KTS ACROSS THE RIDGES. THE COMBINATION OF TEMPS HAVING ALREADY DROPPED INTO THE SINGLE DIGITS ACROSS THE HIGHER ELEVATIONS AND WINDS CONTINUING NOCTURNALLY...HAS LED TO WIND CHILLS AT -10 TO -20 IN THE RIDGES OF WV/MD/PA...THUS PROMPTING THE WIND CHILL ADVISORY. OVERNIGHT...THE SHORT WAVE WILL SHIFT EAST OF THE AREA AND THE SURFACE HIGH WILL PASS SOUTH OF THE AREA. NEGATIVE VORTICITY ADVECTION IN THE DEPARTURE OF THE SHT WV WILL ALLOW LINGERING FLURRIES TO DIMINISH WITH MANY LOCATIONS CLEARING FOR A PERIOD OVERNIGHT. LOCALIZED 30KT 850MB WINDS WILL CONTRIBUTE TO INCREASED WINDS ACROSS THE HIGHER ELEVATIONS AND ALLOW FOR WINDS CHILLS TO REMAIN AT -10 TO -20. ELSEWHERE...TEMPS DROPPING INTO THE SINGLE DIGITS...ESPECIALLY IN AREAS OF CLEARING...WILL ALLOW FOR 0 TO 10 BELOW WIND CHILLS. SATURDAY...THERE IS REASONABLE WRF-ARW/NMM/SREF AGREEMENT THAT A WEAK LOW/CLIPPER SYSTEM WILL DIVE SOUTHEASTWARD FROM THE UPPER MIDWEST INTO THE REGION DURING THE DAY. LIGHT SNOW WILL BE MORE WIDESPREAD WITH LOCALIZED AREAS OF MORE MODERATE SNOW AT TIMES LATER IN THE DAY AS THE SYSTEM CROSSES THE UPPER OHIO VALLEY. THE ONSET OF SNOW IS PROGGED TO BE BETWEEN 12Z AND 15Z IN EASTERN OHIO. THE SNOW WILL CONTINUE INTO THE EVENING...WITH 20:1 SNOW-TO- LIQUID RATIOS BRINGING A LIGHT AND FLUFFY-NATURED SNOW TO THE AREA. WITH AROUND A TENTH OF QPF ANTICIPATED WITH THE SYSTEM...1 TO 2 INCHES SEEMS REASONABLE ACROSS THE LOWLANDS DURING THE DAY WITH 2 TO 3 INCHES FOR THE HIGHER ELEVATIONS. FOR TEMPS...HIGHS ARE CLOSER TO THE COOLER MAV GUIDANCE...WITH CLOUD COVERAGE LIMITING TEMPS. HIGHS WILL RANGE FROM NEAR 20 ACROSS THE LAUREL HIGHLANDS/ALLEGHENY FRONT TO THE MID 20S ACROSS THE LOWLANDS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... SNOW SHOWERS WILL CONTINUE THROUGH SUNDAY WITH A PERIOD OF LIGHTER ACCUMULATION SATURDAY EVENING AS FIRST SHORTWAVE EXITS AND NEXT SHORTWAVE DIVES SOUTHEAST. SNOW SHOWERS WILL RE-INTENSIFY LATER SATURDAY NIGHT INTO MIDDAY SUNDAY. BEHIND 2ND SHORTWAVE SUNDAY FLOW WILL TURN NORTHWEST WITH -14 TO -16C 850MB TEMPS CROSSING LAKES AND DECENT INVERSION HEIGHTS. USING AN AVERAGE SNOW TO LIQUID RATIO OF 20 TO 1 WENT WITH A 36 HOUR SNOWFALL OF 4 TO 6 INCHES OUTSIDE OF RIDGES...WITH 6 TO 10 IN THE HIGHEST ELEVATIONS. HAVE ISSUED A LONG DURATION WINTER WEATHER ADVISORY TO DEAL WITH SNOWFALL. TEMPERATURES SATURDAY NIGHT WILL HOLD FAIRLY STEADY IN THE 20S, THEN HOLD STEADY IN THE 20S EARLY THEN FALL SUNDAY AFTERNOON. STILL SOME LEFTOVER LAKE/UPSLOPE SUNDAY NIGHT AS COLD ADVECTION CONTINUES. FOR MONDAY YET ANOTHER SHORTWAVE WILL BE DIVING SOUTHEAST WITH SNOW SHOWERS DEVELOPING DURING THE DAY. THIS SYSTEM MAY NOT HAVE AS MUCH MOISTURE TO WORK WITH SO HAVE KEPT POPS IN THE CHANCE CATEGORY FOR NOW...TEMPERATURES STILL BELOW NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UNSETTLED PATTERN WILL CONTINUE AT THE BEGINNING OF THE EXTENDED FORECAST. ALTHOUGH SNOW MAY BRIEFLY STOP MONDAY NIGHT INTO TUESDAY MORNING...12Z GFS/ECMWF SHOW THE NEXT CLIPPER PUSHING THROUGH TUESDAY NIGHT. SNOW MAY COME TO AN END WEDNESDAY WITH HIGH PRESSURE OVERHEAD NOT ALLOWING FLOW OFF THE GREAT LAKES. AS THE HIGH MOVES OFFSHORE THURSDAY...SOUTHWEST FLOW SHOULD ALLOW FOR MODERATION IN TEMPERATURES TOWARDS NORMAL LEVELS. 12Z GFS SHOWS A DRY FRONTAL PASSAGE ON FRIDAY...A SEEMINGLY UNLIKELY SCENARIO. WILL GO WITH POPS FOR THE FRONTAL PASSAGE FALLING IN LINE BETTER WITH THE 12Z ECMWF. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... LOW VFR STRATOCU WILL PERSIST INTO THE EVENING AND SLOWLY DIMINISH IN COVERAGE AS THE STRATOCU DECK SCATTERS OUT BY EARLY MORNING. A FEW SNOW SHOWERS WILL CONTINUE INTO THE EARLY EVENING BEFORE ENDING. GENL VFR IS FORECAST FOR TONIGHT AND EARLY SATURDAY..BUT CONDITIONS WILL DEGRADE IFR BY SATURDAY AFTERNOON AS LOW PRESSURE DEVELOPS WIDESPREAD SNOW OVER THE UPPER OHIO VALLEY. .OUTLOOK.../SATURDAY NIGHT THROUGH MONDAY/... PERIODIC RESTRICTIONS ARE EXPECTED THROUGH EARLY NXT WEEK AS A SERIES OF UPPER DISTURBANCES MOVE OFF THE GREAT LAKES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY FOR MDZ001. WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001. OH...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY FOR OHZ039>041-048>050-057>059-068-069. PA...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY FOR PAZ007>009-013>016-020>023-029-031-073>076. WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR PAZ074-076. WV...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY FOR WVZ001>004-012-021>023-041. WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ023-041. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
804 PM EST FRI FEB 1 2013 .SYNOPSIS... A COLD NIGHT CAN BE EXPECTED WITH WIND CHILLS BELOW ZERO. A SERIES OF WEATHER SYSTEMS WILL BRING PERIODS OF ACCUMULATING SNOW FOR THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AN UPDATE HAS BEEN SENT OUT THIS EVENING TO ISSUE A WIND CHILL ADVISORY FOR THE LAUREL HIGHLANDS/ALLEGHENY FRONT OF WV/MD/PA WITH AN SPS ISSUED FOR SUB-ZERO WIND CHILLS ELSEWHERE. IN ADDITION...SCATTERED FLURRIES HAVE BEEN ADDED FOR THIS EVENING ACROSS THE PIT METRO AND NORTHWARD. THE LATEST RAP MID-LEVEL ANALYSIS INDICATES AN INITIAL SHORT WAVE TROUGH PUSHING OFF THE MID-ATLANTIC COAST...WITH LINGERING VORT ENERGY ON THE LEESIDE OF THIS FEATURE PROVIDING ENOUGH FORCING FOR A FEW FLURRIES AND LIGHT SNOW SHOWERS IN WESTERN PA. AT 850MB...TEMPS RANGE FROM -10C TO -16C ACROSS THE AREA TONIGHT...WITH A WEST-NORTHWESTERLY FLOW CONTINUING OFF OF LAKE ERIE. AT THE SURFACE...A 1032MB HIGH IS CENTERED ACROSS THE TENNESSEE VALLEY AND IS EDGING EAST-NORTHEASTWARD TOWARD THE AREA. YET...THE PRESSURE GRADIENT BETWEEN THE HIGH AND A SURFACE LOW WELL NORTH OF THE REGION IS ALLOWING FOR 5-10KT SOUTHWESTERLY WINDS ACROSS THE LOWLANDS AND 10-15KTS ACROSS THE RIDGES. THE COMBINATION OF TEMPS HAVING ALREADY DROPPED INTO THE SINGLE DIGITS ACROSS THE HIGHER ELEVATIONS AND WINDS CONTINUING NOCTURNALLY...HAS LED TO WIND CHILLS AT -10 TO -20 IN THE RIDGES OF WV/MD/PA...THUS PROMPTING THE WIND CHILL ADVISORY. OVERNIGHT...THE SHORT WAVE WILL SHIFT EAST OF THE AREA AND THE SURFACE HIGH WILL PASS SOUTH OF THE AREA. NEGATIVE VORTICITY ADVECTION IN THE DEPARTURE OF THE SHT WV WILL ALLOW LINGERING FLURRIES/SNOW SHOWERS TO DIMINISH AND SOME BREAKS IN CLOUD COVERAGE. LOCALIZED 30KT 850MB WINDS WILL CONTRIBUTE TO INCREASED WINDS ACROSS THE HIGHER ELEVATIONS AND ALLOW FOR WINDS CHILLS TO REMAIN AT -10 TO -20. ELSEWHERE...TEMPS DROPPING INTO THE SINGLE DIGITS...ESPECIALLY IN AREAS OF CLEARING...WILL ALLOW FOR 0 TO 10 BELOW WIND CHILLS. SATURDAY...THERE IS REASONABLE WRF-ARW/NMM/SREF AGREEMENT THAT A WEAK LOW/CLIPPER SYSTEM WILL DIVE SOUTHEASTWARD FROM THE UPPER MIDWEST INTO THE REGION DURING THE DAY. LIGHT SNOW WILL BE MORE WIDESPREAD WITH LOCALIZED AREAS OF MORE MODERATE SNOW AT TIMES LATER IN THE DAY AS THE SYSTEM CROSS THE UPPER OHIO VALLEY. THE ONSET OF SNOW IS PROGGED TO BE BETWEEN 12Z AND 15Z IN EASTERN OHIO. THE SNOW WILL CONTINUE INTO THE EVENING...WITH 20:1 SNOW-TO- LIQUID RATIOS BRINGING A LIGHT AND FLUFFY-NATURED SNOW TO THE AREA. WITH AROUND A TENTH OF QPF ANTICIPATED WITH THE SYSTEM...1 TO 2 INCHES SEEMS REASONABLE ACROSS THE LOWLANDS DURING THE DAY WITH 2 TO 3 INCHES FOR THE HIGHER ELEVATIONS. FOR TEMPS...HIGHS ARE CLOSER TO THE COOLER MAV GUIDANCE...WITH CLOUD COVERAGE LIMITING TEMPS. HIGHS WILL RANGE FROM NEAR 20 ACROSS THE LAUREL HIGHLANDS/ALLEGHENY FRONT TO THE UPPER 20S IN LOCATIONS IN EASTERN OHIO. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... SNOW SHOWERS WILL CONTINUE THROUGH SUNDAY WITH A PERIOD OF LIGHTER ACCUMULATION SATURDAY EVENING AS FIRST SHORTWAVE EXITS AND NEXT SHORTWAVE DIVES SOUTHEAST. SNOW SHOWERS WILL RE-INTENSIFY LATER SATURDAY NIGHT INTO MIDDAY SUNDAY. BEHIND 2ND SHORTWAVE SUNDAY FLOW WILL TURN NORTHWEST WITH -14 TO -16C 850MB TEMPS CROSSING LAKES AND DECENT INVERSION HEIGHTS. USING AN AVERAGE SNOW TO LIQUID RATIO OF 20 TO 1 WENT WITH A 36 HOUR SNOWFALL OF 4 TO 6 INCHES OUTSIDE OF RIDGES...WITH 6 TO 10 IN THE HIGHEST ELEVATIONS. HAVE ISSUED A LONG DURATION WINTER WEATHER ADVISORY TO DEAL WITH SNOWFALL. TEMPERATURES SATURDAY NIGHT WILL HOLD FAIRLY STEADY IN THE 20S, THEN HOLD STEADY IN THE 20S EARLY THEN FALL SUNDAY AFTERNOON. STILL SOME LEFTOVER LAKE/UPSLOPE SUNDAY NIGHT AS COLD ADVECTION CONTINUES. FOR MONDAY YET ANOTHER SHORTWAVE WILL BE DIVING SOUTHEAST WITH SNOW SHOWERS DEVELOPING DURING THE DAY. THIS SYSTEM MAY NOT HAVE AS MUCH MOISTURE TO WORK WITH SO HAVE KEPT POPS IN THE CHANCE CATEGORY FOR NOW...TEMPERATURES STILL BELOW NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UNSETTLED PATTERN WILL CONTINUE AT THE BEGINNING OF THE EXTENDED FORECAST. ALTHOUGH SNOW MAY BRIEFLY STOP MONDAY NIGHT INTO TUESDAY MORNING...12Z GFS/ECMWF SHOW THE NEXT CLIPPER PUSHING THROUGH TUESDAY NIGHT. SNOW MAY COME TO AN END WEDNESDAY WITH HIGH PRESSURE OVERHEAD NOT ALLOWING FLOW OFF THE GREAT LAKES. AS THE HIGH MOVES OFFSHORE THURSDAY...SOUTHWEST FLOW SHOULD ALLOW FOR MODERATION IN TEMPERATURES TOWARDS NORMAL LEVELS. 12Z GFS SHOWS A DRY FRONTAL PASSAGE ON FRIDAY...A SEEMINGLY UNLIKELY SCENARIO. WILL GO WITH POPS FOR THE FRONTAL PASSAGE FALLING IN LINE BETTER WITH THE 12Z ECMWF. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... LOW VFR STRATOCU WILL PERSIST INTO THE EVENING AND SLOWLY DIMINISH IN COVERAGE AS THE STRATOCU DECK SCATTERS OUT BY EARLY MORNING. A FEW SNOW SHOWERS WILL CONTINUE INTO THE EARLY EVENING BEFORE ENDING. GENL VFR IS FORECAST FOR TONIGHT AND EARLY SATURDAY..BUT CONDITIONS WILL DEGRADE IFR BY SATURDAY AFTERNOON AS LOW PRESSURE DEVELOPS WIDESPREAD SNOW OVER THE UPPER OHIO VALLEY. .OUTLOOK.../SATURDAY NIGHT THROUGH MONDAY/... PERIODIC RESTRICTIONS ARE EXPECTED THROUGH EARLY NXT WEEK AS A SERIES OF UPPER DISTURBANCES MOVE OFF THE GREAT LAKES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY FOR MDZ001. WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR MDZ001. OH...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY FOR OHZ039>041-048>050-057>059-068-069. PA...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY FOR PAZ007>009-013>016-020>023-029-031-073>076. WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR PAZ074-076. WV...WINTER WEATHER ADVISORY FROM 10 AM SATURDAY TO 7 PM EST SUNDAY FOR WVZ001>004-012-021>023-041. WIND CHILL ADVISORY UNTIL 10 AM EST SATURDAY FOR WVZ023-041. && $$ SYNOPSIS...WOODRUM NEAR TERM...WOODRUM AVIATION...RSD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EST WED JAN 30 2013 .UPDATE... ISSUED AT 1012 PM EST WED JAN 30 2013 ALL HEADLINES THAT END THIS EVENING HAVE BEEN ALLOWED TO EXPIRE AS SCHEDULED. ATTENTION NOW TURNS TO LAKE ENHANCED/LAKE EFFECT SNOW AS COLDER AIR CONTINUES TO FLOW INTO THE AREA BEHIND DEPARTING STORM SYSTEM. KMQT RADAR HAS SHOWN A NICE EXPANSION OF HVY SNOW BANDS OFF LAKE SUPERIOR THIS EVENING UNDER LINGERING DEEP MOISTURE/CAA...AND VAD WIND PROFILE SHOWS NEARLY UNIDIRECTIONAL NORTHERLY WINDS TO 11KFT MSL. THERE ARE CONFLICTING SIGNALS ON HOW MUCH THE WIND MAY BACK OVERNIGHT AS LOCAL HIGH RES-WRF MAINTAINS A MORE NRLY WIND INTO NCNTRL UPPER MI WHILE NAM BACKS WIND MORE NW. GIVEN TRENDS IN HRLY RUC RAPID REFRESH RUNS TO SLOW THE BACKING...OPTED TO EXTEND WARNING FOR MARQUETTE COUNTY UNTIL 11Z. WITH RATHER PERSISTENT HVY SNOW OCCURRING AT THE OFFICE THIS EVENING AND RADAR IMAGERY SHOWING EXPANSION OF HVY SNOW BANDS...WOULD NOT BE SURPRISED TO SEE SOME LOCALIZED ACCUMULATIONS OVER 1 FOOT DURING THE NIGHT IN THE HIGHER TERRAIN BETWEEN BIG BAY...NEGAUNEE...GWINN AND SKANDIA. THIS HVY SNOW WILL ALSO TARGET WRN ALGER COUNTY WEST OF SHINGLETON. WHILE WARNING FOR ALGER/LUCE/NRN SCHOOLCRAFT ONLY GOES TO 12Z...WILL LET MID SHIFT TAKE A LOOK AT REPLACEMENT WITH A LONGER DURATION LAKE EFFECT SNOW ADVY OR WARNING FOR THAT AREA. TO THE W...NO CHANGES WERE MADE TO THE GOGEBIC/ONTONAGON ADVY. OVER THE KEWEENAW...COLD AIR WILL PUSH THE DGZ DOWN TO NEAR THE SFC... RESULTING IN SMALL SNOWFLAKES THAT ARE VERY EFFECTIVE AT REDUCING VIS. WHILE ACCUMULATIONS WILL PROBABLY ONLY BE IN THE 2-4 INCH RANGE/12HRS AT MOST LOCATIONS...VERY LOW VIS DURING -SHSN ALONG WITH OCNL BLSN SUGGEST AN ADVY HEADLINE IS WARRANTED FOR KEWEENAW/NRN HOUGHTON AS DRIVING WILL BE DIFFICULT AT TIMES. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 441 PM EST WED JAN 30 2013 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM HUDSON BAY AND NW ONTARIO THROUGH MN/IA INTO ERN OK. THE POTENT SHORTWAVE TROUGH OVER SW WI AND ASSOCIATED DEFORMATION ZONE CONTINUED TO SUPPORT A HEAVY SNOW BAND FROM ERN WI INTO THE E HALF OF UPPER MI. LIGHTER SNOW WAS OBSERVED OVER THE WEST HALF OF UPPER MI. SNOW TOTALS OF AROUND 6 INCHES WERE OBSERVED BY 21Z FROM THE NWS MQT OFFICE TO MNM...GLADSTONE AND MANISTIQUE. A TIGHT GRADIENT BTWN THE 987 MB LOW OVER SRN LOWER MI AND ARCTIC HIGH PRES BUILDING INTO THE PLAINS HAS RESULTED IN GALES ACROSS LAKE SUPERIOR AND GUSTY N WINDS TO 30 MPH OVER MOST OF THE CWA. TONIGHT AND THURSDAY...THE HEAVY SNOW BAND WHICH CORRELATED WELL WITH NAM/RUC 700-600 MB FGEN IS EXPECTED TO SHIF QUICKLY TO THE NORTHEAST THIS EVENING LEAVING MAINLY LIGHT SNOW THAT WILL DIMINISH BTWN 00Z-03Z. HOWEVER...COLDER AIR MOVING IN ON THE STRONG N WINDS COMBINED WITH 850 MB TEMPS TO AROUND -15C WILL CONTINUE TO SUPPORT LCLY HIGHER SNOWFALL RATES N CNTRL...ESPECIALLY VCTY MARQUETTE THIS EVENING WITH CYCLONIC LOW LEVEL 340-350 WIND DIRECTION NEAR THE SHORE. FAVORABLE UPSLOPE NRLY FLOW INTO THE FAR WEST SHOULD ALSO BRING INCREASING LES INTO IWD. RADAR TRENDS AND MODELS SUGGEST ADDITIONAL SYNOPTIC SNOW POTENTIAL IN THE 1 TO 3 INCH RANGE BTWN 21Z- 03Z. HOWEVER AREAS WITH LAKE CONTRIBUTION COULD SEE ANOTHER 3 TO 6 INCHES THROUGH 12Z/THU. AS THE STRONGER SYNOPTIC FORCING WITH THE SHRTWV MOVES OUT THIS EVENING...HEADLINES ARE SET TO EXPIRE BY AROUND 03Z OVER THE S CWA. A TRANSISTION TO LAKE EFFECT SNOW WILL CONTINUE OVERNIGHT WITH FAVORABLE CONDITION PERSISTING INTO THURSDAY. ANOTHER TRAILING SHRTWV SLIDING SE INTO THE UPPER LAKES WILL MAINTAIN 850-700 MB MOISTURE AND INVERSION HEIGHTS AOA 10K FT. WITH THE WINDS BACKING SLIGHTLY TO 340-330 THE HEAVIER LES WILL CONTINUE TO FOCUS INTO THE FAR WEST AND TO AREAS EAST OF MARQUETTE. 850 MB TEMPS FALLING TO AROUND -20C MAY SHRINK THE DGZ LAYER INTO THE 1K-3K RANGE BUT STILL SHOULD BE SUFFICIENT FOR LSR VALUES CLOSE TO 25/1. ADDITIONAL SNOWFALL AMOUNTS OF 3 TO 7 INCHES ARE POSSIBLE. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 441 PM EST WED JAN 30 2013 MODELS ARE IN GOOD GENERAL AGREEMENT THROUGH THE EXTENDED WITH DEEP UPPER TROUGH STARTING THE PERIOD FRI AND GRADUALLY BREAKING DOWN AND SHIFTING WEST THROUGH NEXT WED...AS AN UPPER RIDGE MOVES INTO THE WRN CONUS. GOOD NW WIND LES WILL BE ONGOING INTO THU NIGHT GIVEN NW LOW LEVEL FLOW...AMPLE MOISTURE AND 825MB INVERSION TOP TEMPS AROUND -25C. LATE THU NIGHT AND FRI...A SFC HIGH WILL MOVE S OF THE CWA WHILE A SHORTWAVE TROUGH DIVES IN FROM THE NW FORMING A MESO-LOW OVER ERN LAKE SUPERIOR LATE FRI. THIS TURNS THE NW WINDS WLY BY FRI AFTERNOON...FOCUSING LES OVER THE KEWEENAW AND FAR NE UPPER MI. PRIOR WIND SHIFT...THE BEST LES WILL BE FOCUSED OVER ONTONAGON AND GOGEBIC COUNTIES AND OVER ERN UPPER MI FROM MUNISING TO GRAND MARAIS. LES SHOULD INITIALLY WEAKEN SOME LATE THU NIGHT AS RIDGING MOVES INTO THE AREA...BUT WILL GET A BOOST FROM THE SHORTWAVE LATER ON FRIDAY. THERE IS ALREADY A LES ADVISORY FOR ONTONAGON/GOGEBIC COUNTIES THROUGH THU NIGHT...AND THAT STILL LOOKS FINE. BUT WILL LIKELY ALSO NEED HEADLINES FOR THE ERN U.P. THU NIGHT INTO FRI. THE KEWEENAW MAY ALSO NEED HEADLINES FRI INTO FRI NIGHT. WILL NOT ISSUE ANY NEW HEADLINES AT THIS POINT GIVEN HEADLINES ALREADY IN EFFECT OVER THE ERN U.P. AND SOME UNCERTAINTY AS TO THE RESIDENCE TIME AND INTENSITY OF ANY STRONGER BANDS THAT MOVE ACROSS THE KEWEENAW. THU NIGHT THROUGH FRI NIGHT LOOKS TO BE THE COLDEST PERIOD OF THE NEXT WEEK. LOWS THU NIGHT AND FRI NIGHT LOOKS TO FALL TO THE TEENS BELOW ZERO WITH WIND CHILLS TO -35F OVER PARTS OF THE INTERIOR. HIGHS ON FRI LOOK TO BE AROUND ZERO OVER THE INTERIOR W...AND IN THE LOW TEENS ABOVE ZERO E. WIND CHILL VALUES ARE CURRENTLY FORECAST TO BE IN TEENS BELOW ZERO AT THE WARMEST FRI AFTERNOON OVER THE INTERIOR W...AND IN THE SINGLE DIGITS BELOW ZERO E. WILL LIKELY NEED SOME WIND CHILL ADVISORY HEADLINES UP WHERE THERE ARE NO OTHER WINTER WX HEADLINES. MODELS IN RELATIVELY GOOD AGREEMENT WITH A CLIPPER SHORTWAVE MOVING THROUGH LATE SAT INTO EARLY SAT NIGHT...BUT ONLY MINOR SYNOPTIC SNOW ACCUMULATIONS AND INCREASED NW WIND LES ARE EXPECTED TO RESULT FROM THE SYSTEM. SFC RIDGING MOVES OVER ON SUN AHEAD OF THE NEXT...STRONGER...CLIPPER SYSTEM THAT MODEL DEPICT MOVING THROUGH. ALTHOUGH MODELS SEEM TO AGREE FAIRLY WELL ON THE OVERALL TRACK AND INTENSITY OF THE SYSTEM...THE 00Z/30 ECMWF IS 6-12 HOURS FASTER THAN THE 12Z/30 GFS. SEVERAL INCHES OF SNOW MAY RESULT AREA WIDE FROM THIS SYSTEM. MODELS THEN INDICATE...WITH GREATER UNCERTAINTY...ANOTHER CLIPPER SYSTEM MOVING THROUGH SOMETIME MIDWEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1155 PM EST WED JAN 30 2013 AT KIWD...LAKE EFFECT -SHSN WILL INCREASE OVERNIGHT AS COLDER AIR FLOWS INTO THE AREA AND LOW-LEVEL WINDS BECOME MORE CONVERGENT INTO WRN UPPER MI. AS A RESULT...IFR CONDITIONS SHOULD GENERALLY PREVAIL AT KIWD THRU TODAY. SOME IMPROVEMENT IS POSSIBLE THIS EVENING AS WINDS BEGIN TO BACK...POSSIBLY SHIFTING -SHSN N OF KIWD. AT KCMX...IFR CONDITIONS SHOULD PREVAIL OVERNIGHT AS LAKE EFFECT -SHSN CONTINUE UNDER INCREASINGLY COLDER AIR MASS. WITH THE COLDER AIR...SNOWFLAKE SIZE WILL BECOME SMALLER AND VERY EFFECTIVE AT KEEPING VIS LOW. COMBINATION OF SNOW AND SOME BLSN WILL LIKELY RESULT IN LIFR CONDITIONS FOR MUCH OF THE DAY INTO THE EVENING AT KCMX. AT KSAW... LAKE EFFECT SHSN UNDER NORTHERLY WINDS SHOULD LEAD TO IFR/LIFR CONDITIONS FOR THE NEXT SEVERAL HRS. AS WINDS BACK AND PUSH HEAVIER LAKE EFFECT SHSN TO THE E...EXPECT IMPROVEMENT TO MVFR EARLY IN THE MORNING. MVFR SHOULD THEN PREVAIL FOR THE REMAINDER OF THE FCST PERIOD. AS IS TYPICAL FOR LAKE EFFECT SNOW...EXPECT VIS AT ALL SITES TO BE HIGHLY VARIABLE AT TIMES AS SNOW BANDS MOVE ACROSS THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 441 PM EST WED JAN 30 2013 N TO NW GALES OF 35 TO 40 KNOTS WILL CONTINUE THROUGH MUCH OF TONIGHT...WITH A FEW GALE FORCE GUSTS TO 35 KNOTS LINGERING E THROUGH THURSDAY. LOW PRESSURE OVER LOWER MICHIGAN WILL LIFT NORTHEAST INTO ONTARIO AND QUEBEC TONIGHT. WITH PLENTY OF COLD AIR SINKING IN BEHIND THE LOW AND STRONG WINDS...HEAVY FREEZING SPRAY WILL PREVAIL THROUGH THURSDAY NIGHT...AND MAY LINGER OVER THE FAR EAST THROUGH FRIDAY NIGHT. A TROUGH WILL LINGER OVER LAKE SUPERIOR THROUGH THURSDAY...AS STRONG HIGH PRESSURE SINKS ACROSS THE PLAINS STATES. EXPECT THE HIGH PRESSURE SYSTEM TO WEAKEN SLIGHTLY OVER THE MISSISSIPPI VALLEY FRIDAY...WHILE PUSHING A RIDGE ACROSS WESTERN LAKE SUPERIOR. WEAK LOW PRESSURE WILL LINGER ACROSS EASTERN LAKE SUPERIOR THROUGH SATURDAY. ANOTHER LOW PRESSURE TROUGH WILL SINK SOUTHWARD FROM MANITOBA INTO THE UPPER GREAT LAKES SATURDAY EVENING...BEFORE MOVING INTO THE LOWER GREAT LAKES DURING THE DAY SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ FRIDAY FOR MIZ001>003-009. WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR MIZ005. WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR MIZ006-007-085. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST SATURDAY FOR LSZ265>267. GALE WARNING UNTIL 4 AM EST THURSDAY FOR LSZ264>267. HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/ SATURDAY FOR LSZ162-263-264. LAKE MICHIGAN... NONE. && $$ UPDATE...ROLFSON SHORT TERM...JLB LONG TERM...TITUS AVIATION...ROLFSON MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1152 PM EST WED JAN 30 2013 .AVIATION... //DISCUSSION... GUSTY WESTERLY WINDS WILL PERSIST THROUGH THE MORNING AS ARCTIC AIR CONTINUES TO POUR INTO THE FORECAST AREA. STEEPENING LOW LEVEL LAPSE RATES COURTESY OF THE COLD AIR ADVECTION WILL BRING SOME STRONG WIND GUSTS DOWN TO THE SURFACE...LIKELY TOPPING 30 KNOTS AT TIMES THIS MORNING. THE WINDS WILL DIMINISH SLIGHTLY THIS AFTERNOON AS THE GRADIENT RELAXES. WIDESPREAD MVFR CIGS WILL SLOWLY LIFT DURING THE COURSE OF THE TAF PERIOD AS THE COLD AIR ADVECTION LIFTS INVERSION HEIGHTS. WHILE SNOW SHOWERS WILL REMAIN RATHER LIGHT OVERNIGHT...SOME INCREASE IN INTENSITY IS EXPECTED AFTER 12Z...PRIMARILY FROM PTK SOUTH. WITH STILL SOME UNCERTAINTY AS TO HOW THE LAKE BANDS WILL SET UP...WILL CONTINUE WITH MVFR TYPE CIGS/VSBY IN THE SNOW SHOWERS THROUGH THE MORNING AT THIS TIME. FOR DTW...EXPECT WESTERLY WIND GUSTS AROUND OR ABOVE 30 KNOTS THROUGH THE MORNING AND INTO THE AFTERNOON. THERE IS A POTENTIAL FOR ENHANCED SNOW SHOWERS OFF LAKE MICHIGAN TO IMPACT THE AIRPORT AFTER 12Z. GIVEN THE LOW CONFIDENCE AT THIS STAGE IN THE FORECAST...WILL HOLD OFF ON INTRODUCING IFR TYPE CONDITIONS AT THIS TIME. //DTW THRESHOLD THREATS... * HIGH CONFIDENCE IN CEILING BELOW 5000 FT THROUGH THE TAF PERIOD. * HIGH CONFIDENCE WESTERLY WIND GUSTS WILL EXCEED 28 KNOTS BETWEEN 06Z AND 19Z THURS. && .PREV DISCUSSION...ISSUED 1007 PM EST WED JAN 30 2013 UPDATE... THE WIDESPREAD RAIN WHICH HAS BEEN ROLLING ACROSS THE FORECAST AREA THIS EVENING WILL QUICKLY LIFT OFF TO THE NORTHEAST OVER THE NEXT COUPLE OF HOURS. RECENT OBSERVATIONS INDICATE THE BULK OF THESE HEAVIER SHOWERS WILL BE OFF TO THE EAST PRIOR TO THE ARRIVAL OF THE ARCTIC AIR AND CHANGE OVER TO SNOW. NONETHELESS...THE ADVANCE OF DEEPER MOISTURE WITHIN THE MID LEVEL TROUGH AXIS WILL ROTATE THROUGH THE FORECAST AREA OVERNIGHT PROVIDING SOME LIGHT SNOW SHOWERS TO THE AREA. THE RESPONSE OFF LAKE MI FROM THE AGGRESSIVE PUSH OF COLD AIR TONIGHT WILL ALSO BE QUITE GOOD. LAKE ENHANCED SNOW SHOWERS SHOULD SUPPORT SOME HIGHER POPS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA OVERNIGHT. THE HIGHER INTENSITY SNOW SHOWERS SHOULD HOLD OFF UNTIL AFTER DAYBREAK...SO SNOW ACCUMS TONIGHT SHOULD BE MINOR. THE ARCTIC FRONT IS NOW ON THE DOORSTEP OF THE FORECAST AREA AND WILL TRACK EAST OF THE AREA SHORTLY AFTER MIDNIGHT. OVER THE NEXT TWO HOURS...TEMPS WILL RAPIDLY DROP BELOW FREEZING. WHILE THE WINDS WILL HELP DRY THE ROAD SURFACES A BIT...EXPECT THERE WILL SOME SLICK ROADS OVERNIGHT. THE SURFACE LOW NOW OVER LAKE HURON WILL CONTINUE TO DEEPEN AS IT PULLS NORTHEAST OF THE REGION OVERNIGHT. MEANWHILE...STRONG COLD AIR ADVECTION WILL STEEPEN THE LOW LEVEL LAPSE RATES. THE MOST RECENT RAP AND 18Z NAM CONTINUE TO SHOW A SOLID 40-45 KTS IN THE MIXED LAYER OVERNIGHT /ESPECIALLY ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA/. THUS THE CURRENT WIND ADVISORY HEADLINE FOR MUCH OF THE FORECAST AREA WILL REMAIN IN EFFECT. PREV DISCUSSION...ISSUED 345 PM EST WED JAN 30 2013 SHORT TERM... TONIGHT THERE ARE SEVERAL CONCERNS ASSOCIATED WITH THE FORECAST TONIGHT FOR CONDITIONS THAT WILL HAVE AT LEAST MODERATE IMPACT AROUND SE MICHIGAN. THE ADVISORY FOR HIGH WIND WILL BE MOST SIGNIFICANT FOLLOWED CLOSELY BY THE COMBINATION OF FALLING TEMPERATURES AND RAIN CHANGING TO SNOW ADDING A LAYER OF COMPLEXITY. ALL OF THIS WILL BE DRIVEN BY A WAVE OF LOW PRESSURE THAT WILL MOVE FROM SOUTHWEST LOWER MICHIGAN DURING THE AFTERNOON, THROUGH CENTRAL LAKE HURON AND INTO EASTERN ONTARIO TONIGHT, ALL THE WHILE DEEPENING AS IT GOES. THE DEEPENING TREND OF THE LOW AS IT PASSES TO OUR EAST WILL BE FOSTERED BY THE DYNAMICS OF THE NEGATIVE TILT SHORT WAVE THAT IS ALREADY TAKING SHAPE IN SATELLITE IMAGERY DURING THE AFTERNOON. INCREASING SURFACE WIND TRAILING THE LOW IS ALSO OBSERVED TO PRODUCE WIND GUSTS AROUND 30 KNOTS OVER THE MIDWEST AT PRESS TIME. WITH THE SYSTEM ALREADY OFF TO A GOOD START, CONFIDENCE IS INCREASED IN THE DEPICTIONS SHOWN IN THE ARRAY OF 12Z MODEL OUTPUT THAT BUILD A STRONG WESTERLY WIND FIELD OVER SE MICHIGAN BY MIDNIGHT. SOME GUSTINESS IS EXPECTED IN THE WARMER AIR AHEAD OF THE FRONT, ASSOCIATED WITH THE LOW LEVEL JET, AND WITH THE ISALLOBARIC COMPONENT OF FORCING IMMEDIATELY BEHIND THE FRONT, BUT THESE ELEMENTS ARE NOT EXPECTED TO EXCEED ADVISORY CRITERIA. THAT IS INSTEAD LIKELY TO OCCUR TOWARD MIDNIGHT THROUGH WEDNESDAY MORNING AS DYNAMICALLY DRIVEN MID LEVEL SUBSIDENCE AND STRONG COLD ADVECTION HELP DIRECT A 45-50 KNOT WIND FIELD TOWARD THE SURFACE FROM THE 850 TO 700 MB LAYER. MODEL CROSS SECTIONS INDICATE NEARLY 10 DEGREES(K) OF THETA SURFACES INTERSECTING THE GROUND DURING THE INTERVAL OF ISENTROPIC DECENT. MODEL SOUNDINGS THEN SHOW THE MIXED LAYER DEEPENING TO NEAR THE 800 MB LEVEL FOR THE LATE OVERNIGHT HOURS WITH 45 KNOTS OF WIND AVAILABLE FOR CONTRIBUTION TO SURFACE WIND GUSTS. AREAL COVERAGE WILL BE GREATEST ALONG AND SOUTH OF INTERSTATE 69 WITH THE THUMB VULNERABLE DUE TO WIND GUSTS MOVING OFF OF SAGINAW BAY. PLAN TO LEAVE THE TRI CITIES OUT OF THE HEADLINE FOR NOW. THE STRONG WINDS WILL PULL DRAMATICALLY COLDER AIR INTO SE MICHIGAN DURING THE NIGHT WITH READINGS DROPPING INTO THE UPPER TEENS IN THE TRI CITIES BY SUNRISE TO THE MID 20S METRO DETROIT. THE BULK OF PRECIPITATION WILL COME IN THE FORM OF RAIN SHOWERS THROUGH MID EVENING WITH THE CHANGE TO SNOW AT THE VERY TAIL END FOR JUST A DUSTING OF ACCUMULATION IN THE DETROIT AREA AND UP TO AN INCH IN THE NORTHERN THUMB. LONG TERM... LAKE MICHIGAN LAKE EFFECT MACHINE WILL BE CRANKING UP THURSDAY...ENHANCED BY A GOOD UPPER LEVEL WAVE/MID LEVEL COLD POOL SWINGING THROUGH THE MIDWEST/WESTERN OHIO VALLEY TOMORROW AFTERNOON. STRONG WESTERLY WINDS (35-45 MPH) IN WAKE OF THE QUICKLY DEEPENING LOW PRESSURE WILL USHER IN SUFFICIENTLY COLD AIRMASS...UPPER NEGATIVE TEENS AT 850 MB OVER LOWER MICHIGAN...BUT LOWER NEGATIVE 20S SWINGING THROUGH THE WESTERN OHIO VALLEY. 700 MB COLD POOL OF -28 TO -30 C OVER SOUTHERN LOWER MICHIGAN THURSDAY EVENING WITH MODEST 925-850 MB LIFT/CONVERGENCE EXTENDING INTO SOUTHEAST MICHIGAN...AND PLANNING ON CARRYING NUMEROUS POPS..ALTHOUGH FOCUS OF ACTIVITY WILL LIKELY SHIFT FROM NORTH TO SOUTH THROUGH THE NIGHT AS MODEST 850 THETA-E RIDGE SETTLES SOUTH. WITH A HIGH FLUFF FACTOR TO SNOW...20+:1 RATIOS...A QUICK INCH OR TWO IS LIKELY IN SPOTS AS 925-850 MB PROFILES REMAIN IN THE DENDRITIC ZONE GROWTH REGION. HEART OF THE COLD AIR/THERMAL TROUGH AXIS WILL BE IN PLACE FOR FRIDAY...WITH 850 MB TEMPS HOVERING AROUND -20 C ON FRIDAY...AND HAVE NO COMPLAINTS WITH INHERITED MAXES IN THE UPPER TEENS TO AROUND 20...IN LINE WITH LATEST GUIDANCE. A SURFACE RIDGE WILL ATTEMPT TO MOVE IN FRIDAY NIGHT. IF THIS IS SUFFICIENT IN CLEARING OUT THE LOW CLOUDS...LOOKING AT MINS AT OR BELOW ZERO FOR MUCH OF THE AREA WITH EXPECTED FRESH SNOW COVER. CONFIDENCE IS NOT HIGH...AND WILL HAVE TO PLAY IT CONSERVATIVE (LOW/MID SINGLE NUMBERS) AS THERE IS ALSO LURKING WARM ADVECTION CLOUDS STREAMING INTO THE WESTERN GREAT LAKES. POLAR VORTEX LOOKS TO BE ANCHORED OVER/NEAR FAR NORTHERN HUDSON BAY/SOUTHAMPTON ISLAND OVER THE NEXT SEVERAL DAYS...AND THIS WILL MAINTAIN THE UPPER LEVEL NORTHWEST FLOW WITH A COUPLE SHORTWAVES/CLIPPER SYSTEMS TO IMPACT OR TRACK NEAR SOUTHERN LOWER MICHIGAN. WITH MOISTURE AT A PREMIUM...USUALLY NEED TO BE ON THE NORTHEAST FLANK OF THE LOW (WARM ADVECTION/ISENTROPIC ASCENT/MOISTURE CONVERGENCE) TO GET ANY SUBSTANTIAL SNOWFALL. BEST GUESS AT TIMING OF SYSTEMS WOULD BE SATURDAY NIGHT AND THEN AGAIN ON MONDAY. 12Z TRENDS OF EURO/GFS SUGGEST SATURDAY NIGHTS SYSTEM WILL TRACK JUST A BIT TOO FAR SOUTH...WITH MONDAYS SYSTEM/TRACK MORE FAVORABLE. THE EARLY NEXT WEEK LOW WILL ALSO HAVE A BIT MORE OF A PACIFIC ORIGIN...AND THUS A BIT MORE MOISTURE. STILL TOO EARLY TO GET A GOOD HANDLE OF THE GULF OF ALASKA ENERGY AND EVENTUAL BREAKDOWN/SPILLING OVER INTO THE CONUS HOWEVER. MARINE... A POWERFUL COLD FRONT WILL SWEEP THROUGH LAKE HURON AND LOWER MICHIGAN TONIGHT. INCREASING NORTHWEST WINDS AND A SURGE OF COLDER AIR WILL BRING GALES TO ALL MARINE AREAS. CONSIDERABLE INSTABILITY ACROSS THE LONG FETCH IN NORTHWEST FLOW OF THE OPEN WATERS WILL MAINTAIN A LONGER PERIOD OF GALES FOR CENTRAL PORTIONS OF THE LAKE THROUGH THURSDAY. THE COMBINATION OF THE STRONG WINDS, ARCTIC AIR, AND COLDER WATER TEMPERATURE WILL LEAD TO HEAVY FREEZING SPRAY ACROSS NORTHERN SECTIONS OF LAKE HURON DURING THIS TIME. HIGH PRESSURE WILL SETTLE OVER THE OHIO VALLEY AND BRING IMPROVED CONDITIONS BY FRIDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY...MIZ049-MIZ054-MIZ055-MIZ061-MIZ062-MIZ063-MIZ068- MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-MIZ083...UNTIL NOON THURSDAY. LAKE HURON... GALE WARNING...LHZ361...UNTIL NOON THURSDAY. HEAVY FREEZING SPRAY WARNING...LHZ361-LHZ362...UNTIL 7 PM THURSDAY. GALE WARNING...LHZ362-LHZ363-LHZ462-LHZ463-LHZ464...UNTIL 7 PM THURSDAY. GALE WARNING...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY...UNTIL 4 PM THURSDAY. LAKE ST CLAIR... GALE WARNING...UNTIL 4 PM THURSDAY. MI WATERS OF LAKE ERIE... GALE WARNING...UNTIL 4 PM THURSDAY. && $$ AVIATION.....SC UPDATE.......SC SHORT TERM...BT LONG TERM....SF MARINE.......BT YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS HASTINGS NE
656 PM CST FRI FEB 1 2013 .UPDATE...EVENING UPPER AIR ANALYSIS INDICATES LONGWAVE TROUGHING OVER THE EASTERN TWO-THIRDS OF THE CONUS...WITH RIDGING BUILDING INTO THE WEST. MID AND UPPER LEVEL FLOW REMAINS FROM THE NORTHWEST ACROSS THE CENTRAL PLAINS...MAXING OUT AT AROUND 70KTS NEAR 200MB OVER OUR AREA. WATER VAPOR IMAGERY INDICATES A SUBTLE MID LEVEL SHORT WAVE EXTENDING FROM THE DAKOTAS...SOUTHWEST INTO WESTERN NEBRASKA AND SOUTHEASTERN WYOMING. AT THE SURFACE A WEAK AREA OF BAROMETRIC PRESSURE EXISTS OVER EASTERN SOUTH DAKOTA...WITH A TROUGH EXTENDING SOUTHWEST FROM THE LOW ACROSS PORTIONS OF NEBRASKA AND KANSAS. THIS TROUGH PRETTY MUCH BISECTS OUR CWA...WITH THE LOW LEVEL WIND FIELD ACROSS THE SOUTHEASTERN HALF OF OUR CWA REMAINING FROM THE SOUTHWEST...AND LOCATIONS FARTHER NORTHWEST NOW OBSERVING A SURFACE WIND FROM THE NORTHWEST. RADAR DATA FROM KUEX...KLNX...AND KGLD ALL INDICATE LIGHT ELEVATED PRECIPITATION EXTENDING FROM PORTIONS OF WESTERN NEBRASKA INTO NORTHWESTERN KANSAS AND NORTHEASTERN COLORADO. REPORTS OF PRECIPITATION ACTUALLY BEING REALIZED AT THE SURFACE HAVE BEEN FEW AND FAR IN BETWEEN HOWEVER...WITH PROXIMITY SOUNDINGS FROM LAPS AND RAP ANALYSIS INDICATING A VERY DRY LOWER TROPOSPHERE IS LIKELY PREVENTING MUCH OF ANY PRECIPITATION FROM MAKING IT TO THE SURFACE. GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...SREF-MEAN...AND RAP ALL SUGGEST THE MID LEVEL SHORT WAVE...CURRENTLY OVER THE NORTHERN AND CENTRAL PLAINS...WILL CONTINUE MOVING SOUTHEAST TONIGHT...WITH THE MID LEVEL TROUGH AXIS EXPECTED TO CLEAR OUR CWA SHORTLY AFTER 06Z. VERY WEAK MID LEVEL THERMAL ADVECTION AHEAD OF THE TROUGH AXIS IS CREATING JUST ENOUGH OMEGA FOR THE ELEVATED PRECIPITATION CURRENTLY BEING INDICATED BY AREA RADARS...WITH THIS AXIS OF WEAK OMEGA EXPECTED TO CONTINUE PUSHING ACROSS OUR AREA TONIGHT AS THE MID LEVEL TROUGH AXIS DOES THE SAME. THE BACK EDGE OF THIS OMEGA AXIS IS APPARENTLY ALREADY WORKING INTO NORTHERN AND WESTERN NEBRASKA...WITH KLNX INDICATING THE BACK EDGE ELEVATED PRECIPITATION EXTENDING FROM NEAR KANW TO NEAR KIBM. GIVEN THE CURRENT MOVEMENT OF THE MID LEVEL SHORT WAVE ON WATER VAPOR IMAGERY...AND RADAR TRENDS THROUGH THE PAST 2-3 HOURS...IT APPEARS THE BEST CHANCE FOR PRECIPITATION OVER OUR AREA WILL OCCUR BETWEEN NOW AND 06Z...WITH DRY CONDITIONS LIKELY THEREAFTER AS THE MID LEVEL TROUGH AXIS CLEARS THE AREA AND SUBSIDENCE SETTLES IN. DESPITE THE RETURNS AS INDICATED BY AREA RADARS...ITS HARD TO IGNORE THE VERY DRY LOWER TROPOSPHERE CURRENTLY IN PLACE AND THUS IS SEEMS UNLIKELY MEASURABLE PRECIPITATION WILL BE REALIZED ACROSS ANY OF OUR CWA TONIGHT. GIVEN THIS...WENT AHEAD AND PULLED POPS FROM THE FORECAST FOR TONIGHT. THAT BEING SAID...CANNOT COMPLETELY RULE OUT AN OCCASIONAL SPRINKLE MAKING IT TO THE SURFACE THROUGH THE NEXT FEW HOURS AS THERE HAVE BEEN A FEW OBSERVATIONS ACROSS WESTERN NEBRASKA WHICH INDICATED A BRIEF PERIOD OF PRECIPITATION HERE OR THERE. GIVEN THE AFOREMENTIONED RADAR RETURNS AND OBSERVATIONS...OPTED TO GO WITH A MENTION OF SPRINKLES ACROSS OR SOUTHWESTERN CWA THROUGH THIS EVENING AS THE MOST ENHANCED AREA OF RADAR RETURNS...AROUND 25DBZ...PUSH OVER THOSE AREAS. PROXIMITY SOUNDINGS FROM ACROSS OUR CWA PER LAPS AND RAP ANALYSIS INDICATE AN ELEVATED WARM LAYER DOES EXIST NEAR 850MB...WITH FORECAST PROXIMITY SOUNDINGS PER THE NAM...OPERATIONAL GFS...AND RAP SUGGESTING THIS ELEVATED WARM LAYER WILL REMAIN INTACT THROUGH MUCH OF THE NIGHT. IF MORE SIGNIFICANT PRECIPITATION WERE EXPECTED TO MAKE IT TO THE SURFACE...THIS WOULD CERTAINLY CREATE CONCERNS WITH RESPECT TO FREEZING RAIN. THAT BEING SAID...BECAUSE THE RADAR RETURNS THUS FAR THIS EVENING HAVE BEEN SO WEAK...AND BECAUSE THE MAJORITY GUIDANCE SUGGESTS NO PRECIPITATION WILL BE REALIZED OVER OUR AREA TONIGHT...AND BECAUSE THERE IS SUCH A DEEP LAYER OF LOWER TROPOSPHERIC DRY AIR IN PLACE...AM NOT OVERLY CONCERNED WITH AN ICING THREAT AT THIS TIME. SHOULD SPRINKLES BE REALIZED ACROSS PORTIONS OF THE CWA AFTER 02Z TONIGHT...THEN TECHNICALLY THESE WOULD BE FREEZING SPRINKLES AS SURFACE TEMPERATURES WILL HAVE DROPPED BELOW FREEZING BY THEN. BUT AT THIS TIME THE THREAT OF ICING FROM SUCH ACTIVITY IS LITTLE TO NONE AND GIVEN THIS...OPTED TO PULL ANY MENTION OF FREEING RAIN FROM THE HWO. REMAINDER OF THE FORECAST REMAINS IN GOOD SHAPE...WITH ONLY SOME MINOR TWEAKS MADE TO HOURLY TEMPERATURE...SKY...WIND...AND DEWPOINT GRIDS TO ACCOUNT FOR CURRENT OBSERVATIONS. && .PREV DISCUSSION... /ISSUED 516 PM CST FRI FEB 1 2013/ AVIATION...00Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS. MID LEVEL CLOUDS GENERALLY BETWEEN 5000 AND 10000FT AGL WILL BE POSSIBLE THROUGH MUCH OF THE TAF PERIOD. THE SURFACE WIND WILL TRANSITION FROM THE SOUTHWEST TO THE NORTHWEST TONIGHT. THE SURFACE WIND WILL ALSO INCREASE IN INTENSITY DURING THE DAY SATURDAY...SUSTAINED AROUND 18KTS AND GUSTING NEAR 26KTS. RESTRICTION IN VISIBILITY IS NOT EXPECTED THROUGH THE NEXT 24 HOURS. PREV DISCUSSION... /ISSUED 324 PM CST FRI FEB 1 2013/ .A TROF EMBEDDED IN NW FLOW MAY DELIVER A LIGHT WINTRY MIX IN SPOTS TNGT THEN WE DEAL WITH WINDY CONDITIONS N OF I-80 SAT... SHORT TERM...TONIGHT AND SATURDAY UPPER-LEVELS: A +PNA PATTERN WAS IN PLACE...WITH A WRN N AMERICA RIDGE AND AN ERN TROF. A PAIR OF PV ANOMALIES WERE DIVING DOWN THE BACK SIDE OF THE LGWV TROF. THE 1ST WAS OVER WY AT MID AFTN WITH THE 2ND OVER ALBERTA HEADING FOR MT. THE FIRST SHRTWV TROF WILL SLIDE INTO AND THRU KS TNGT. THE SECOND WILL FOLLOW IT INTO NEB AFTER MIDNGT. A SHRTWV RIDGE FOLLOWS SAT MRNG...WITH A THIRD PV ANOMALY MISSING AND HEADING INTO IA...AS THE LGWV PATTERN PROGRESSES A BIT AND HGTS RISE. STRONG MO HIGH PRES WILL DEPART TO THE MID-ATLC STATES TNGT. THE ARCTIC FRONT BISECTED NEB-KS. THIS FRONT AND ITS THERMAL RIBBON WERE BEING SHOVED E BY SW FLOW AHEAD OF A VERY WEAK SFC LOW. THIS LOW TRACKS JUST N OF THE FCST AREA...TO THE MS RIVER BY DAYBREAK SAT. HIGH PRES FOLLOWS HERE TOMORROW. TNGT: VARIABLE CLOUDS BUT OVERALL EXPECT SKIES TO AVERAGE M/CLOUDY. EXPANDED THREAT OF VERY LIGHT PCPN TO THE ENTIRE FCST AREA AND WE NOW HAVE CHANCE POPS FOR AREAS NE OF THE TRI-CITIES AND FROM HWY 136 DOWN INTO N-CNTRL KS. ODDS ARE MOST PLACES REMAIN DRY WITH LACK OF MSTR IN THE SUB-CLOUD LAYER...BUT WAS NOT COMFORTABLE WITH AN ENTIRELY DRY FCST. NEXT ISSUE IS PCPN TYPE. BOTH DDC/LBF HAD A WARM NOSE IN 12Z SOUNDINGS. NAM/GFS BUFKIT SOUNDINGS SUGGEST 850 MB HAS WARMED TO +3C OVERHEAD THIS AFTN. SO "IF" PCPN FALLS TNGT...PLAYED IT AS FLURRIES OR A BRIEF SNOW SHWR NE OF THE TRI-CITIES...FLURRIES OR SPRINKLES IN THE TRI-CITIES...AND SPRINKLES AND POSSIBLY A RAIN SHWR S OF HWY 6 INTO N-CNTRL KS. THAT SAID...BELOIT IS STILL SUB- FRZG AND THE REST OF N-CNTRL KS NOT MUCH ABOVE FRZG. IF TEMPS COOL BACK DOWN BELOW FRZG AND A FEW -SHRA OCCUR...THERE COULD BE A TOUCH OF GLAZE. THE LOW PROBABILITY THREAT IS NOW OUTLOOKED IN THE HWO. BEST CHANCE OF PCPN WILL OCCUR 9PM-3AM. USED BURST OF PW AND K-INDEX TO ASSIST IN TIMING/LOCATION OF POPS THRU THE FCST AREA. CHANCE POPS S OF HWY 136 WERE BASED ON HI-RES MODEL REFLECTIVITY WHICH IS SUPPORTED BY THE TRACK OF THE PV ANOMALY. TEMPS: VARIABLE CLOUD COVER LOWERS CONFIDENCE SOMEWHAT...BUT OVERALL THINK IT WILL BE A MILD NGT. TEMPS ARE BIAS CORRECTED BLEND OF 2M TEMPS AND THE PREVIOUS GID FCST /21-27F/. SAT: SKIES SHOULD BE P/CLOUDY S AND W OF THE TRI-CITIES AT DAWN... AND M/CLOUDY N AND E. CLEARING AS THE DAY PROGRESSES AND WINDY N OF I-80 IN THE "WARM" SECTOR OF THE NEXT PV ANOMALY AND CLIPPER FCST OVER IA. WIND: THERE IS A LOW PROBABILITY WE MAY NEED A WIND ADVISORY FOR SOME OF OUR COUNTIES N OF I-80. SUBJECTIVE PROBABILITY PUTS IT AROUND 40 PERCENT. WITH THE STRENGTH OF THE LOW-LEVEL WIND FIELDS...BUFKIT MIXING HGTS ARE UNNERVING FROM BOTH THE NAM/GFS. FOR NOW WE/VE INCLUDED G40 MPH IN THE FCST. THE MAIN CORE OF THE STRONGEST WIND MOVES IN AFTER 21Z. THE 15Z SREF MEAN INCREASES SPEEDS 40-45 KTS 21Z-00Z. THIS COINCIDES WITH PEAK HEATING AND WILL NEED TO BE CONSIDERED BY THE MID SHIFT. TEMPS ARE BIAS CORRECTED MOS GUIDE WITH SOME ADDITIONAL LOWERING OF TEMPS OVER THE SNOW COVER S AND E OF HASTINGS AND SOME RAISING FROM LXN DOWN TO THE KS BORDER...WHERE BIAS CORRECTION PROBABLY CUT TEMPS TOO MUCH. LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. BEGINNING SATURDAY NIGHT...A NORTHWEST FLOW PATTERN WILL BE IN PLACE ACROSS THE CENTRAL PLAINS AND SHORTWAVE ENERGY IS PROGGED TO TRANSLATE SOUTHEAST ALONG THE MISSOURI RIVER. COLD AIR BACKS IN BRIEFLY FOR THE OVERNIGHT TIME FRAME...THEN IN RETURN FLOW ON SUNDAY THE AIRMASS MODERATES BEHIND THE DEPARTING WAVE. THE NORTHWEST FLOW PATTERN REMAINS PROGRESSIVE THROUGH MID WEEK WEEK WITH A SERIES OF WAVES TRANSLATING THRU FLOW...MAINLY ALONG AND EAST OF THE MISSOURI RIVER...WHICH WILL BRING A FEW COLD FRONTS ACROSS THE PLAINS WITH THE BRUNT OF THE COOLER AIR REMAINING TO OUR EAST. IN THIS REGIME WE WILL SEE ALTERNATING PERIODS OF WAA/CAA BUT WITH CONDITIONS REMAINING DRY. AROUND MID WEEK...THE RIDGING OVER THE ROCKIES BREAKS DOWN AND SETTLES ONTO THE PLAINS ALLOWING FOR A PROGRESSIVE BUT MORE ZONAL FLOW PATTERN. EXTENDED MODELS ARE FAIRLY CONSISTENT WITH YET ANOTHER SHORTWAVE TROUGH TO CROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY NIGHT...AND MODELS ARE HINTING THAT FRONT MAY BECOME ACTIVE WEDNESDAY NIGHT NEAR OUR SOUTHEAST ZONES. CONFIDENCE IN PCPN THIS FAR OUT IS NOT HIGH AND WILL CONTINUE TO MONITOR. ONCE THIS WAVE DEPARTS...AN UPPER RIDGE SETTLES ACROSS THE INTERIOR CONUS WHILE AN UPSTREAM TROUGH MOVES INTO THE ROCKIES. THE WEATHER PATTERN LOOKS TO BECOME MORE ACTIVE NEXT WEEKEND WITH THE PROGRESSION OF THE WESTERN TROUGH AND THIS WILL BE SOMETHING TO KEEP AN EYE ON. UNTIL THAT TIME FRAME HOWEVER...LOOK FOR MAINLY DRY CONDITIONS WITH TEMPS ABOVE NORMAL FOR THE MOST PART...ESPECIALLY AFTER THE SNOW MELTS IN OUR EASTERN ZONES. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ 0656 PM UPDATE/AVIATION...BRYANT SHORT TERM...HALBLAUB LONG TERM...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1126 PM CST WED JAN 30 2013 .AVIATION...06Z KGRI TAF...AN APPROACHING UPPER LEVEL DISTURBANCE WILL SPREAD MVFR CIGS ACROSS THE TERMINAL BY THE EARLY MORNING HOURS THURSDAY...WITH A FEW SNOW FLAKES NOT OUT OF THE QUESTION. ALREADY SEEING MVFR CIGS TO THE NORTHWEST AT KVTN WITH SOME -SN...AND EXPECT THIS CLOUD COVER TO REACH KGRI AROUND 31/12Z...AND PERSIST THROUGH AROUND 31/18Z. WINDS WILL THE PRIMARY FOCUS THROUGH THE DAY THURSDAY AS AN AREA OF SURFACE HIGH PRESSURE OVER THE DAKOTAS SLIDES SOUTHWARD...RESULTING IN A TIGHTENING PRESSURE GRADIENT. EXPECT WINDS TO GUST AS HIGH AS 30KTS DURING THE AFTERNOON HOURS...BEFORE RAPIDLY DIMINISHING AROUND 01/00Z...AS THE CENTER OF THIS HIGH PRESSURE SYSTEM REACHES EASTERN NEBRASKA. && .PREV DISCUSSION... /ISSUED 956 PM CST WED JAN 30 2013/ UPDATE...EVENING UPPER AIR ANALYSIS PER RAP ANALYSIS DATA SUGGESTS A LARGE MID AND UPPER LEVEL LONGWAVE TROUGH PERSISTS OVER THE CENTRAL CONUS. MID AND UPPER LEVEL JET ENERGY EXTENDS SOUTH/SOUTHEAST ACROSS THE WESTERN CONUS...THEN EAST ACROSS THE SOUTHERN PLAINS...AND EVENTUALLY NORTHEAST ACROSS THE EASTERN ONE- THIRD OF THE CONUS. ALTHOUGH MID AND UPPER TROPOSPHERIC FLOW HAS BEEN FAIRLY WEAK OVER OUR AREA THROUGH THIS EVENING...THE MID LEVEL WIND FIELD IS INTENSIFYING WITH THE APPROACH OF A ~80KT MID LEVEL JET STREAK FROM THE NORTHWEST. WATER VAPOR IMAGERY INDICATES FAIRLY MEAGER MID LEVEL MOISTURE OVER OUR AREA...ALTHOUGH SOME MODEST INCREASE IN MID LEVEL MOISTURE IS NOTED ADVECTING INTO THE AREA FROM THE NORTHWEST VIA THE MID LEVEL JET AXIS. A MID LEVEL SHORT WAVE IS ALSO NOTED OVER PORTIONS OF SOUTHERN MANITOBA AND SOUTHERN ONTARIO...MOVING SOUTH/SOUTHEAST WITHIN THE MEAN FLOW. AT THE SURFACE LOW BAROMETRIC PRESSURE IS NOTED OVER PORTIONS OF CENTRAL NEBRASKA...WITH RAPIDLY INCREASING BAROMETRIC PRESSURE NOTED UPSTREAM ACROSS THE DAKOTAS AND PORTIONS OF MONTANA. THE LOW LEVEL WIND FIELD OVER OUR AREA REMAINS FAIRLY LIGHT BUT STILL FROM THE NORTHWEST FOR THE MOST PART. GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN ALL SUGGEST THE MID LEVEL SHORT WAVE...CURRENTLY ADVANCING SOUTH/SOUTHEAST FROM SOUTHERN CANADA...WILL CONTINUE MOVING SOUTHEAST ACROSS PORTIONS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY THROUGH THE NEXT 18-24 HOURS. IT APPEARS AS THOUGH THE PRIMARY AXIS OF OMEGA AHEAD OF THE MID LEVEL TROUGH AXIS WILL REMAIN NORTHEAST OF OUR AREA...ALTHOUGH THE SOUTHWESTERN PERIPHERY OF THE MID LEVEL TROUGH AXIS COULD EXTEND JUST FAR ENOUGH SOUTHWEST TO CLIP NORTHEASTERN PORTIONS OF OUR CWA AND GENERATE SOME VERY LIGHT PRECIPITATION TONIGHT. FORECAST PROXIMITY SOUNDINGS FROM ACROSS OUR CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST LOW TO MID TROPOSPHERIC MOISTURE WILL LIKELY REMAIN TOO MEAGER FOR SIGNIFICANT PRECIPITATION PRODUCTION...BUT STILL CANNOT RULE OUT A FEW SNOW FLURRIES ACROSS OUR NORTHEAST. OVERALL THE GOING FORECAST IS IN GREAT SHAPE...BUT DID GO AHEAD AND TRIM THE MENTION OF FLURRIES ACROSS OUR CWA...AND THIS MENTION IS NOW RELEGATED TO OUR FAR NORTHEASTERN CWA. FORECAST OVERNIGHT LOWS ALSO LOOK GOOD FOR THE TIME BEING...GENERALLY IN THE TEENS WITH THURSDAY MORNING APPARENT TEMPERATURE VALUES APPROACHING -10 ACROSS OUR NORTHEAST AROUND SUNRISE. ALL OTHER CHANGES WERE TO HOURLY TEMPERATURE...WIND...SKY...AND DEWPOINT GRIDS TO BETTER REFLECT CURRENT CONDITIONS. PREV DISCUSSION... /ISSUED 423 PM CST WED JAN 30 2013/ SHORT TERM...TONIGHT AND THURSDAY. WE WILL BE WITHIN NORTHWEST FLOW...BETWEEN THE MEAN TROUGH IN THE EAST AND RIDGE ON THE WEST COAST. ANOTHER SHORTWAVE TROUGH SWINGS TROUGH LATE TONIGHT/EARLY THURSDAY MORNING TO GIVE US A SHOT AT SOME FLURRIES...ESPECIALLY NORTH. SREF INDICATING SOME SPOTTY LOW CHANCES OF ACCUMULATING PRECIPITATION...BUT LEANING TOWARDS FLURRIES WITH THE DRY LOWER LEVELS. SOME VORTICITY HOLDS ON LONGER IN THE SOUTH...SO KEPT SOME SLIGHT CHANCES OF FLURRIES THERE THROUGH THE ENTIRE MORNING. STRONG COLD AIR ADVECTION IS ADVERTISED AS SURFACE HIGH PRESSURE BUILDS IN TOMORROW. WITH ANTICIPATED CONSIDERABLE SKY COVER FOR MOST OF THE DAY AND 18Z 850 MB TEMPS NEAR -20C NEAR ORD TO -10C IN THE SOUTHERN CWA...TEMPERATURES WILL NOT GO VERY FAR...SO HAVE LOWERED TEMPERATURES CONSIDERABLY FOR THURSDAY...ESPECIALLY NORTH. THE WIND WILL BECOME BRISK AGAIN FOR THURSDAY WITH THE STRONG COLD AIR ADVECTION....WITH PLACES NEAR 0RD APPROACHING -15F IN THE EARLY MORNING THURSDAY. SNOW PACK MAY HAVE SOME AFFECT ON TEMPERATURES...BUT MOST OF THE CHILL WILL BE FROM THE COLD AIR ADVECTION ANTICIPATED. LONG TERM...THURSDAY EVENING THROUGH NEXT WEDNESDAY. THE SHORT STORY THROUGH THIS 6-DAY PERIOD IS THAT THE FORECAST REMAINS PRECIPITATION FREE...ALTHOUGH WILL HAVE TO WATCH FOR THE POTENTIAL FOR SOME PESKY FLURRIES OR VERY LIGHT SNOW DEVELOPMENT FRIDAY/FRIDAY NIGHT MAINLY NORTHEAST. OTHERWISE...TEMPERATURES WILL BE A CONSIDERABLE CHALLENGE ESPECIALLY FRIDAY-SATURDAY AS WARMER AIR MOVING IN FROM THE WEST STARTS A FIERCE BATTLE WITH THE RESPECTABLE 1-5 INCH SNOW PACK NOW BLANKETING THE SOUTHEAST 1/2 OF OUR CWA. OVERALL THOUGH...LEGITIMATELY ABOVE NORMAL TEMPERATURES IN THE 40S/50S LOOK TO DOMINATE THE EARLY-MIDDLE PART OF NEXT WEEK. STARTING OFF THURSDAY NIGHT...MODELS SUCH AS THE 12Z NAM/GFS/ECMWF ARE IN GOOD AGREEMENT THAT THE VERY BEGINNING STAGES OF MODEST WARM AIR ADVECTION WILL START GETTING UNDERWAY IN THE LOW LEVELS...AS THE COLD MID/UPPER TROUGH EDGES FARTHER EAST AWAY FROM THE CENTRAL PLAINS. AT THE SURFACE...THE CWA WILL BE NEAR OR JUST WEST OF A FAIRLY STRONG SURFACE RIDGE AXIS CENTERED OVER THE MO VALLEY THROUGH THE FIRST PART OF THE NIGHT...WHILE SOUTHERLY BREEZES OF AROUND 10 MPH WILL KICK INTO GEAR LATER IN THE NIGHT IN THE RETURN FLOW AROUND THE DEPARTING HIGH. AS A RESULT...DEPENDING ON CLOUD COVER TEMPS COULD REALLY DIP IN THE EVENING BEFORE EXHIBITING A SLIGHT LATE-NIGHT RISE. CLOUD TRENDS WILL BE A BIT TRICKY...AS MODELS SHOW THE POTENTIAL FOR A TRANSIENT BAND OF MID LEVEL SATURATION WORKING ACROSS THE CWA FROM WEST-EAST THROUGH THE NIGHT. ALTHOUGH ITS NOT OUT OF THE QUESTION A FEW FLURRIES COULD TRY FORMING FROM THIS...CHANCES LOOK LOW ENOUGH TO LEAVE OUT AT THIS TIME. AS FOR ACTUAL LOW TEMPS...LOWERED EAST-NORTHEAST ZONES A BIT FROM PREVIOUS FORECAST. NOW HAVE LOWS DOWN IN THE SINGLE DIGITS ABOVE ZERO MOST AREAS...EXCEPT FOR A 10-15 RANGE FAR SOUTHWEST WHERE THE SOUTH WINDS KICK IN A BIT SOONER. FRIDAY/FRIDAY NIGHT...AS ALREADY MENTIONED WILL NEED TO MONITOR FOR SOME LOW-IMPACT FLURRY/VERY LIGHT SNOW ACTIVITY ESPECIALLY IN NORTHEAST COUNTIES AS A LOW AMPLITUDE SHORTWAVE TROUGHS DROPS OVERHEAD IN WEST-NORTHWEST FLOW ALOFT...BUT WITH THIS STILL BEING 4-5 PERIODS OUT AM CONTENT LEAVING IT OUT FOR NOW...AND LET LATER SHIFTS TAKE A CLOSER LOOK. NO MATTER WHAT...THE MUCH BETTER FOCUS FOR POTENTIALLY MEASURABLE SNOW WILL FOCUS WELL EAST INTO IA. HIGH TEMPS FRIDAY ARE REALLY GOING TO BE A CHALLENGE...ESPECIALLY ALONG THE INTERFACE BETWEEN THE NEARLY SNOW-FREE GROUND AND THE DEEPER SNOWPACK. BREEZY SOUTHWEST WINDS SHOULD HAVE NO PROBLEM BOOSTING ROUGHLY THE WESTERN HALF OF THE CWA WELL INTO THE 40S...WHILE EASTERN AREAS COULD STAY WELL DOWN IN THE LOW-MID 30S. CONFIDENCE IN THE MAGNITUDE OF THIS GRADIENT IS FAIRLY LOW AT THIS TIME. LOWS FRIDAY NIGHT ARE FORECAST QUITE A BIT WARMER THAN THURS NIGHT THANKS TO DEVELOPING WESTERLY FLOW BEHIND A PASSING TROUGH AXIS...AND HAVE ALL AREAS HOLDING UP IN THE LOW-MID 20S. SATURDAY/SATURDAY NIGHT...CONTINUED WEST-NORTHWEST DOWNSLOPE LOW LEVEL FLOW SHOULD AID THE CONTINUED WARM-UP...AND MADE LITTLE CHANGE TO HIGHS WITH MOST OF THE CWA REACHING THE MID-UPPER 40S...EXCEPT FOR LOW 40S IN THE FAR SOUTHEAST ESPECIALLY AROUND HEBRON WHERE THE DEEPER SNOW EXISTS. SUNDAY/SUNDAY NIGHT...CONFIDENCE REMAINS FAIRLY HIGH IN DRY CONDITIONS...DESPITE THE PASSAGE OF ANOTHER QUICK MOVING SHORTWAVE TROUGH IN THE PERSISTENT WEST/NORTHWEST FLOW ALOFT. THE ONLY REAL IMPACT FROM THIS WAVE AT THE SURFACE WILL BE THE PASSAGE OF ANOTHER MODEST SURFACE TROUGH MAINLY SUNDAY NIGHT. FOR HIGHS...ANTICIPATE THAT THE SNOWPACK-EFFECTS SHOULD BE TEMPERED A BIT VERSUS FRIDAY/SATURDAY...SO HAVE A BIT MORE UNIFORM TEMPERATURE FIELD...WITH UPPER 40S/LOW 50S MOST AREAS EXCEPT MID 40S IN THE SOUTHEAST. MONDAY/MONDAY NIGHT...CONTINUED NORTHWESTERLY FLOW ALOFT AS A BROAD RIDGE STARTS BUILDING EASTWARD OVER THE WESTERN CONUS A BIT. THE PREFERRED ECWMF SOLUTION KEEPS ANY PRECIP-PRODUCING SHORTWAVE ENERGY WELL EAST OF THE LOCAL AREA ALONG AN AXIS FROM THE DAKOTAS THROUGH IA. WITH LITTLE CHANGE IN THE LOW LEVEL TEMP FIELDS...HAVE HIGHS SIMILAR TO SUNDAY WITH MOST AREAS UPPER 40S TO LOW 50S. TUESDAY/TUESDAY NIGHT...CONTINUED DRY AS A BRIEF PERIOD OF MID/UPPER RIDGING TRANSLATES OVERHEAD...AND AGAIN VERY SIMILAR HIGH TEMPERATURES AS PREVIOUS FEW DAYS WITH UPPER 40S MOST NEB ZONES AND LOW-MID 50S KS. WEDNESDAY...STILL NO LEGITIMATE SIGN OF PRECIP...AS MODELS ADVERTISE FAIRLY UNEVENTFUL QUASI-ZONAL FLOW AT THIS TIME. ONCE AGAIN...HIGHS RANGING UPPER 40S NORTHEAST TO MID-50S SOUTHWEST. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
240 PM EST THU JAN 31 2013 .SYNOPSIS... COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND WEAK UPPER LEVEL DISTURBANCES. && .NEAR TERM /THROUGH TONIGHT/... 12 NOON UPDATE... WE`VE PUSHED BACK THE START TIME OF THE LES WRNG BY A FEW HRS IN NRN ONEIDA (NOW 21Z). BASED ON THE LATEST KBUF VWP (STILL A 260 FLOW OVER A DEEP LYR)...AND OVERALL RADAR PRESENTATION...WE THINK THE ONSET OF THE +SN IN NRN ONEIDA WILL BE SOMEWHAT DELAYED FROM OUR EARLIER FCST. THE AMTS STILL LOOK REPRESENTATIVE...AS PARAMETERS SEEM FAVORABLE FOR FAIRLY INTENSE RATES...ONCE THE SNOW DOES FINALLY MOVE IN. 10 AM UPDATE... OUR CURRENT FCST IS IN EXCELLENT SHAPE ATTM...SO ONLY COSMETIC CHGS WERE MADE. AS STG CAA CONTS TO FILTER ACRS THE FA LATE THIS MRNG...LES BANDS ARE TRYING TO ORGANIZE OFF BOTH LKS ERIE AND ONT. AS JUDGED FROM THE 12Z RAOBS AT BUF/DTX...THE MIXED LYR EXTENDS UP TO ABT 750 MB...WITH A FAIR MOISTURE SUPPLY UNDERNEATH THE BASE OF THE INVERSION. GIVEN CONTD CYCLONIC FLOW...FURTHER COOLING WITH TIME...AND IF ANYTHING...A DEEPENING OF THE SYNOPTIC MOISTURE THIS AFTN AND EVE...THERE`S NO REASON NOT TO EXPECT THE DVLPMT OF FAIRLY STG LAKE-EFFECT PLUMES OFF BOTH LKS. IN-HOUSE CAPE/SHEAR NOMOGRAM SHOWS ENUF OVER-LAND INSTAB THROUGH THIS EVE (00-03Z)...SO THAT THE BANDS MAY TAKE ON SOMEWHAT OF A CELLULAR APPEARANCE...AT TIMES. HOWEVER...ORGANIZATION IS NOT LIKELY TO BE SERIOUSLY COMPROMISED. ALSO...THE CSTAR-DERIVED INLAND EXTENT APPLICATION DEPICTS A FAIRLY DEEP INLAND PENETRATION THROUGHOUT THE EVE HRS...AT LEAST...WITH A GOOD UPSTREAM CONNECTION TO HURON/NRN LK MI/SUPERIOR...AND ALSO STG 0-1 KM SPEED SHEAR. THIS ALSO SEEMS WELL SUPPORTED BY SIM REFLECTIVITY PRESENTATIONS FROM THE NAM12...LOCAL ARW...AND HRRR MODELS. BOTTOM LN...THINGS APPEAR WELL ON TRACK FOR THE LES WRNG IN NRN ONEIDA...WITH A PD OF VERY HVY SNOW ANTICIPATED...FROM ROUGHLY 22-06Z. GIVEN DEEP MOISTURE...AND EXCELLENT CRYSTAL GROWTH PARAMETERS...2-3"/HR RATES ARE NOT OUT OF THE QUESTION. ELSEWHERE (ONONDAGA/MADISON/SRN ONEIDA)...DESPITE SOME ANTICIPATED WEAKENING LTR TNT...AS THE BAND DROPS SWD...THERE MAY BE ENUF RESIDUAL INTENSITY FOR ADVSY-LVL ACCUMS. WE`LL RE-VISIT THIS SITN EARLY THIS AFTN. ACRS THE TWIN TIERS...SOME CONVECTIVE SHSN ARE LIKELY TO FORM BY MID TO LATE AFTN...AIDED A BIT BY ADVECTION OF MOISTURE FROM LKS ERIE AND SRN MI IN STG WRLY FLOW. OVERALL...THOUGH...THE NATURE OF THEM WILL REMAIN SCTD. AS FOR THE WINDS...THEY`RE LIKELY TO BE AT THEIR PEAK THROUGH ABT 18Z...WITH A SLOW DIMINISHING TREND THEREAFTER...AS JUDGED FROM ISALLOBARIC AND MOMENTUM TRANSFER PROGS. A STEADY OR SLOWLY FALLING TEMP TREND IS WELL HANDLED IN THE GRIDS...SO ONLY VERY MINOR TWEAKS WERE NEEDED. PREV DISC... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO SIG CHGS TO FCST. PREV BLO... 450 AM...DROPPED FLOOD WATCH FOR THE CNTRL SRN TIER AND PORTIONS OF THE FINGER LAKES AS BACK EDGE OF STEADIER RAIN HAS EXITED THIS RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE 40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO... BACK EDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF 315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL CONTINUE TO MONITOR CAREFULLY. MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE WARNING. SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAINLY DUE TO LAKE INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW END ADVISORY IS NEEDED HERE. AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF THE BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE 09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL JUST MENTION THE POTNL IN THE HWO AND LET THE DAY SHIFT ISSUE HEADLINES FOR THIS EVENT IF NEEDED. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT. IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... 230 PM UPDATE... LK EFFECT SNOW WL START OFF THE LONG TERM AS SYSTEM EXITS OFF OF THE EAST COAST. NW FLOW WL BRING CLD AIR ACRS THE LKS ALONG WITH NEAR SEASONAL TEMPS. CLIPPER TYPE LOW WL MV THRU THE UPR MIDWEST AND MID-ATLANTIC SPREADING LIGHT SNOW INTO THE REGION ON TUESDAY. 12Z MED RANGE GUIDANCE SHOWS SLIGHT DISCREPANCIES IN HOW FAR NORTH CLIPPER TRACKS ON MON NGT INTO TUESDAY. WITH GFS BEING FURTHER NORTH AND EC SUPPRESSED FURTHER TO THE SOUTH, HV SIDED WITH HPC GUIDANCE WITH LOW-MID RANGE CHC POPS FOR THIS TIME PD. SYSTEM WL SKIRT TO THE SOUTH AS HIPRES WL BUILD IN FM THE NORTH. HV ASSIGNED LOCHC POPS TO THE ENTIRE AREA FOR TUE NGT THEN THINKING IT WL TRANSITION TO A LGT LES EVENT ACRS FINGER LKS REGION WITH JUST FLURRIES ELSEWHERE. SFC HIPRES WL BUILD IN WED NGT AND THURSDAY. L/WV TROF FCST TO DROP INTO THE PLAINS TWD THE END OF THE PD WITH LIGHT SNOW SPREADING INTO CWA BY 12Z FRIDAY. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... 18Z UPDATE... SNOW HAS MOVED INTO ALL TERMINALS BEHIND COLD FRONT. WITH SCATTERED SNOW SHOWERS, CONDS WILL RANGE FROM VFR TO MVFR THOUGH AN OCCASIONAL IFR CANNOT BE RULED OUT. AS LAKE EFFECT BAND GETS ORGANIZED IFR VSBYS WILL MOVE INTO KRME AFTER 03Z AND KSYR AFTER 09Z. AT KELM AND KITH EXPECT MVFR CONDS TONIGHT WITH FLOW OFF OF LAKE ERIE THOUGH KBGM AND KAVP SHOULD REMAIN LOW VFR. WINDS OUT OF THE SOUTHWEST THIS AFTERNOON AROUND 25KTS WILL GUST TO 30-40KTS. WINDS WILL REMAIN GUSTY NEXT 24 HOURS THOUGH GUSTS WILL LESSEN TO AROUND 25KTS AND GRADUALLY SWITCH AROUND TO A MORE WEST-NORTHWEST DIRECTION. .OUTLOOK... SAT/SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY. SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY. TUE...MVFR/IFR IN LIGHT SNOW AT ALL TERMINALS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044- 045-055-056-062. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009- 015>018-022-036-037-046-057. LAKE EFFECT SNOW WARNING UNTIL 7 AM EST FRIDAY FOR NYZ009. LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST FRIDAY FOR NYZ022. LAKE EFFECT SNOW ADVISORY FROM 4 AM TO 7 PM EST FRIDAY FOR NYZ018-036-037. && $$ SYNOPSIS... NEAR TERM...MLJ SHORT TERM... LONG TERM...PVN AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
123 PM EST THU JAN 31 2013 .SYNOPSIS... COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND WEAK UPPER LEVEL DISTURBANCES. && .NEAR TERM /THROUGH TONIGHT/... 12 NOON UPDATE... WE`VE PUSHED BACK THE START TIME OF THE LES WRNG BY A FEW HRS IN NRN ONEIDA (NOW 21Z). BASED ON THE LATEST KBUF VWP (STILL A 260 FLOW OVER A DEEP LYR)...AND OVERALL RADAR PRESENTATION...WE THINK THE ONSET OF THE +SN IN NRN ONEIDA WILL BE SOMEWHAT DELAYED FROM OUR EARLIER FCST. THE AMTS STILL LOOK REPRESENTATIVE...AS PARAMETERS SEEM FAVORABLE FOR FAIRLY INTENSE RATES...ONCE THE SNOW DOES FINALLY MOVE IN. 10 AM UPDATE... OUR CURRENT FCST IS IN EXCELLENT SHAPE ATTM...SO ONLY COSMETIC CHGS WERE MADE. AS STG CAA CONTS TO FILTER ACRS THE FA LATE THIS MRNG...LES BANDS ARE TRYING TO ORGANIZE OFF BOTH LKS ERIE AND ONT. AS JUDGED FROM THE 12Z RAOBS AT BUF/DTX...THE MIXED LYR EXTENDS UP TO ABT 750 MB...WITH A FAIR MOISTURE SUPPLY UNDERNEATH THE BASE OF THE INVERSION. GIVEN CONTD CYCLONIC FLOW...FURTHER COOLING WITH TIME...AND IF ANYTHING...A DEEPENING OF THE SYNOPTIC MOISTURE THIS AFTN AND EVE...THERE`S NO REASON NOT TO EXPECT THE DVLPMT OF FAIRLY STG LAKE-EFFECT PLUMES OFF BOTH LKS. IN-HOUSE CAPE/SHEAR NOMOGRAM SHOWS ENUF OVER-LAND INSTAB THROUGH THIS EVE (00-03Z)...SO THAT THE BANDS MAY TAKE ON SOMEWHAT OF A CELLULAR APPEARANCE...AT TIMES. HOWEVER...ORGANIZATION IS NOT LIKELY TO BE SERIOUSLY COMPROMISED. ALSO...THE CSTAR-DERIVED INLAND EXTENT APPLICATION DEPICTS A FAIRLY DEEP INLAND PENETRATION THROUGHOUT THE EVE HRS...AT LEAST...WITH A GOOD UPSTREAM CONNECTION TO HURON/NRN LK MI/SUPERIOR...AND ALSO STG 0-1 KM SPEED SHEAR. THIS ALSO SEEMS WELL SUPPORTED BY SIM REFLECTIVITY PRESENTATIONS FROM THE NAM12...LOCAL ARW...AND HRRR MODELS. BOTTOM LN...THINGS APPEAR WELL ON TRACK FOR THE LES WRNG IN NRN ONEIDA...WITH A PD OF VERY HVY SNOW ANTICIPATED...FROM ROUGHLY 22-06Z. GIVEN DEEP MOISTURE...AND EXCELLENT CRYSTAL GROWTH PARAMETERS...2-3"/HR RATES ARE NOT OUT OF THE QUESTION. ELSEWHERE (ONONDAGA/MADISON/SRN ONEIDA)...DESPITE SOME ANTICIPATED WEAKENING LTR TNT...AS THE BAND DROPS SWD...THERE MAY BE ENUF RESIDUAL INTENSITY FOR ADVSY-LVL ACCUMS. WE`LL RE-VISIT THIS SITN EARLY THIS AFTN. ACRS THE TWIN TIERS...SOME CONVECTIVE SHSN ARE LIKELY TO FORM BY MID TO LATE AFTN...AIDED A BIT BY ADVECTION OF MOISTURE FROM LKS ERIE AND SRN MI IN STG WRLY FLOW. OVERALL...THOUGH...THE NATURE OF THEM WILL REMAIN SCTD. AS FOR THE WINDS...THEY`RE LIKELY TO BE AT THEIR PEAK THROUGH ABT 18Z...WITH A SLOW DIMINISHING TREND THEREAFTER...AS JUDGED FROM ISALLOBARIC AND MOMENTUM TRANSFER PROGS. A STEADY OR SLOWLY FALLING TEMP TREND IS WELL HANDLED IN THE GRIDS...SO ONLY VERY MINOR TWEAKS WERE NEEDED. PREV DISC... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO SIG CHGS TO FCST. PREV BLO... 450 AM...DROPPED FLOOD WATCH FOR THE CNTRL SRN TIER AND PORTIONS OF THE FINGER LAKES AS BACK EDGE OF STEADIER RAIN HAS EXITED THIS RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE 40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO... BACK EDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF 315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL CONTINUE TO MONITOR CAREFULLY. MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE WARNING. SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAINLY DUE TO LAKE INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW END ADVISORY IS NEEDED HERE. AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF THE BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE 09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL JUST MENTION THE POTNL IN THE HWO AND LET THE DAY SHIFT ISSUE HEADLINES FOR THIS EVENT IF NEEDED. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT. IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE MONDAY NIGHT/TUESDAY. PREVIOUS DISCUSSION... FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS. REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH WEAK HIGH PRESSURE MON AFTN. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... 18Z UPDATE... SNOW HAS MOVED INTO ALL TERMINALS BEHIND COLD FRONT. WITH SCATTERED SNOW SHOWERS, CONDS WILL RANGE FROM VFR TO MVFR THOUGH AN OCCASIONAL IFR CANNOT BE RULED OUT. AS LAKE EFFECT BAND GETS ORGANIZED IFR VSBYS WILL MOVE INTO KRME AFTER 03Z AND KSYR AFTER 09Z. AT KELM AND KITH EXPECT MVFR CONDS TONIGHT WITH FLOW OFF OF LAKE ERIE THOUGH KBGM AND KAVP SHOULD REMAIN LOW VFR. WINDS OUT OF THE SOUTHWEST THIS AFTERNOON AROUND 25KTS WILL GUST TO 30-40KTS. WINDS WILL REMAIN GUSTY NEXT 24 HOURS THOUGH GUSTS WILL LESSEN TO AROUND 25KTS AND GRADUALLY SWITCH AROUND TO A MORE WEST-NORTHWEST DIRECTION. .OUTLOOK... SAT/SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY. SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY. TUE...MVFR/IFR IN LIGHT SNOW AT ALL TERMINALS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044- 045-055-056-062. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009- 015>018-022-036-037-046-057. LAKE EFFECT SNOW WARNING UNTIL 7 AM EST FRIDAY FOR NYZ009. && $$ SYNOPSIS... NEAR TERM...MLJ SHORT TERM... LONG TERM...MDP/TAC AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1150 AM EST THU JAN 31 2013 .SYNOPSIS... COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND WEAK UPPER LEVEL DISTURBANCES. && .NEAR TERM /THROUGH TONIGHT/... 12 NOON UPDATE... WE`VE PUSHED BACK THE START TIME OF THE LES WRNG BY A FEW HRS IN NRN ONEIDA (NOW 21Z). BASED ON THE LATEST KBUF VWP (STILL A 260 FLOW OVER A DEEP LYR)...AND OVERALL RADAR PRESENTATION...WE THINK THE ONSET OF THE +SN IN NRN ONEIDA WILL BE SOMEWHAT DELAYED FROM OUR EARLIER FCST. THE AMTS STILL LOOK REPRESENTATIVE...AS PARAMETERS SEEM FAVORABLE FOR FAIRLY INTENSE RATES...ONCE THE SNOW DOES FINALLY MOVE IN. 10 AM UPDATE... OUR CURRENT FCST IS IN EXCELLENT SHAPE ATTM...SO ONLY COSMETIC CHGS WERE MADE. AS STG CAA CONTS TO FILTER ACRS THE FA LATE THIS MRNG...LES BANDS ARE TRYING TO ORGANIZE OFF BOTH LKS ERIE AND ONT. AS JUDGED FROM THE 12Z RAOBS AT BUF/DTX...THE MIXED LYR EXTENDS UP TO ABT 750 MB...WITH A FAIR MOISTURE SUPPLY UNDERNEATH THE BASE OF THE INVERSION. GIVEN CONTD CYCLONIC FLOW...FURTHER COOLING WITH TIME...AND IF ANYTHING...A DEEPENING OF THE SYNOPTIC MOISTURE THIS AFTN AND EVE...THERE`S NO REASON NOT TO EXPECT THE DVLPMT OF FAIRLY STG LAKE-EFFECT PLUMES OFF BOTH LKS. IN-HOUSE CAPE/SHEAR NOMOGRAM SHOWS ENUF OVER-LAND INSTAB THROUGH THIS EVE (00-03Z)...SO THAT THE BANDS MAY TAKE ON SOMEWHAT OF A CELLULAR APPEARANCE...AT TIMES. HOWEVER...ORGANIZATION IS NOT LIKELY TO BE SERIOUSLY COMPROMISED. ALSO...THE CSTAR-DERIVED INLAND EXTENT APPLICATION DEPICTS A FAIRLY DEEP INLAND PENETRATION THROUGHOUT THE EVE HRS...AT LEAST...WITH A GOOD UPSTREAM CONNECTION TO HURON/NRN LK MI/SUPERIOR...AND ALSO STG 0-1 KM SPEED SHEAR. THIS ALSO SEEMS WELL SUPPORTED BY SIM REFLECTIVITY PRESENTATIONS FROM THE NAM12...LOCAL ARW...AND HRRR MODELS. BOTTOM LN...THINGS APPEAR WELL ON TRACK FOR THE LES WRNG IN NRN ONEIDA...WITH A PD OF VERY HVY SNOW ANTICIPATED...FROM ROUGHLY 22-06Z. GIVEN DEEP MOISTURE...AND EXCELLENT CRYSTAL GROWTH PARAMETERS...2-3"/HR RATES ARE NOT OUT OF THE QUESTION. ELSEWHERE (ONONDAGA/MADISON/SRN ONEIDA)...DESPITE SOME ANTICIPATED WEAKENING LTR TNT...AS THE BAND DROPS SWD...THERE MAY BE ENUF RESIDUAL INTENSITY FOR ADVSY-LVL ACCUMS. WE`LL RE-VISIT THIS SITN EARLY THIS AFTN. ACRS THE TWIN TIERS...SOME CONVECTIVE SHSN ARE LIKELY TO FORM BY MID TO LATE AFTN...AIDED A BIT BY ADVECTION OF MOISTURE FROM LKS ERIE AND SRN MI IN STG WRLY FLOW. OVERALL...THOUGH...THE NATURE OF THEM WILL REMAIN SCTD. AS FOR THE WINDS...THEY`RE LIKELY TO BE AT THEIR PEAK THROUGH ABT 18Z...WITH A SLOW DIMINISHING TREND THEREAFTER...AS JUDGED FROM ISALLOBARIC AND MOMENTUM TRANSFER PROGS. A STEADY OR SLOWLY FALLING TEMP TREND IS WELL HANDLED IN THE GRIDS...SO ONLY VERY MINOR TWEAKS WERE NEEDED. PREV DISC... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO SIG CHGS TO FCST. PREV BLO... 450 AM...DROPPED FLOOD WATCH FOR THE CNTRL SRN TIER AND PORTIONS OF THE FINGER LAKES AS BACK EDGE OF STEADIER RAIN HAS EXITED THIS RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE 40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO... BACK EDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF 315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL CONTINUE TO MONITOR CAREFULLY. MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE WARNING. SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAINLY DUE TO LAKE INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW END ADVISORY IS NEEDED HERE. AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF THE BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE 09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL JUST MENTION THE POTNL IN THE HWO AND LET THE DAY SHIFT ISSUE HEADLINES FOR THIS EVENT IF NEEDED. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT. IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE MONDAY NIGHT/TUESDAY. PREVIOUS DISCUSSION... FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS. REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH WEAK HIGH PRESSURE MON AFTN. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... 12Z UPDATE... STRONG COLD FRONT IS JUST FINISHING ITS BLAST THROUGH THE AREA...TAKING THE STEADIER RAIN SHOWERS WITH IT. WINDS WILL HAVE A MUCH EASIER TIME MIXING DOWN IN THE COLD AIR BEHIND THE FRONT...ALLOWING WESTERLY GUSTS FREQUENTLY IN THE 30-40 KT RANGE. GUSTS AT KSYR AND PERHAPS KRME WILL EVEN TOP OUT AROUND 35-45 KTS AT TIMES TODAY. EXPECTING SCT-BKN CLOUD DECK WITH SCT -SHSN AND MVFR CIG FOR SOME TERMINALS. THOUGH GENERALLY VFR TO MVFR IN TAFS TODAY WITH THE SNOW FLURRIES...SOME TERMINALS WILL HAVE TO WATCH FOR BRIEF SURPRISE IFR VIS FROM A HEAVIER LAKE EFFECT SNOW SHOWER. THE MAIN LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME IN OCCASIONAL IFR VIS AFTER 03Z...AND BY 09Z ONWARD FOR KSYR. .OUTLOOK... FRI THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY. SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044- 045-055-056-062. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009- 015>018-022-036-037-046-057. LAKE EFFECT SNOW WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST FRIDAY FOR NYZ009. && $$ SYNOPSIS... NEAR TERM...MLJ SHORT TERM... LONG TERM...MDP/TAC AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1023 AM EST THU JAN 31 2013 .SYNOPSIS... COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND WEAK UPPER LEVEL DISTURBANCES. && .NEAR TERM /THROUGH TONIGHT/... 10 AM UPDATE... OUR CURRENT FCST IS IN EXCELLENT SHAPE ATTM...SO ONLY COSMETIC CHGS WERE MADE. AS STG CAA CONTS TO FILTER ACRS THE FA LATE THIS MRNG...LES BANDS ARE TRYING TO ORGANIZE OFF BOTH LKS ERIE AND ONT. AS JUDGED FROM THE 12Z RAOBS AT BUF/DTX...THE MIXED LYR EXTENDS UP TO ABT 750 MB...WITH A FAIR MOISTURE SUPPLY UNDERNEATH THE BASE OF THE INVERSION. GIVEN CONTD CYCLONIC FLOW...FURTHER COOLING WITH TIME...AND IF ANYTHING...A DEEPENING OF THE SYNOPTIC MOISTURE THIS AFTN AND EVE...THERE`S NO REASON NOT TO EXPECT THE DVLPMT OF FAIRLY STG LAKE-EFFECT PLUMES OFF BOTH LKS. IN-HOUSE CAPE/SHEAR NOMOGRAM SHOWS ENUF OVER-LAND INSTAB THROUGH THIS EVE (00-03Z)...SO THAT THE BANDS MAY TAKE ON SOMEWHAT OF A CELLULAR APPEARANCE...AT TIMES. HOWEVER...ORGANIZATION IS NOT LIKELY TO BE SERIOUSLY COMPROMISED. ALSO...THE CSTAR-DERIVED INLAND EXTENT APPLICATION DEPICTS A FAIRLY DEEP INLAND PENETRATION THROUGHOUT THE EVE HRS...AT LEAST...WITH A GOOD UPSTREAM CONNECTION TO HURON/NRN LK MI/SUPERIOR...AND ALSO STG 0-1 KM SPEED SHEAR. THIS ALSO SEEMS WELL SUPPORTED BY SIM REFLECTIVITY PRESENTATIONS FROM THE NAM12...LOCAL ARW...AND HRRR MODELS. BOTTOM LN...THINGS APPEAR WELL ON TRACK FOR THE LES WRNG IN NRN ONEIDA...WITH A PD OF VERY HVY SNOW ANTICIPATED...FROM ROUGHLY 22-06Z. GIVEN DEEP MOISTURE...AND EXCELLENT CRYSTAL GROWTH PARAMETERS...2-3"/HR RATES ARE NOT OUT OF THE QUESTION. ELSEWHERE (ONONDAGA/MADISON/SRN ONEIDA)...DESPITE SOME ANTICIPATED WEAKENING LTR TNT...AS THE BAND DROPS SWD...THERE MAY BE ENUF RESIDUAL INTENSITY FOR ADVSY-LVL ACCUMS. WE`LL RE-VISIT THIS SITN EARLY THIS AFTN. ACRS THE TWIN TIERS...SOME CONVECTIVE SHSN ARE LIKELY TO FORM BY MID TO LATE AFTN...AIDED A BIT BY ADVECTION OF MOISTURE FROM LKS ERIE AND SRN MI IN STG WRLY FLOW. OVERALL...THOUGH...THE NATURE OF THEM WILL REMAIN SCTD. AS FOR THE WINDS...THEY`RE LIKELY TO BE AT THEIR PEAK THROUGH ABT 18Z...WITH A SLOW DIMINISHING TREND THEREAFTER...AS JUDGED FROM ISALLOBARIC AND MOMENTUM TRANSFER PROGS. A STEADY OR SLOWLY FALLING TEMP TREND IS WELL HANDLED IN THE GRIDS...SO ONLY VERY MINOR TWEAKS WERE NEEDED. PREV DISC... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO SIG CHGS TO FCST. PREV BLO... 450 AM...DROPPED FLOOD WATCH FOR THE CNTRL SRN TIER AND PORTIONS OF THE FINGER LAKES AS BACK EDGE OF STEADIER RAIN HAS EXITED THIS RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE 40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO... BACK EDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF 315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL CONTINUE TO MONITOR CAREFULLY. MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE WARNING. SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAINLY DUE TO LAKE INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW END ADVISORY IS NEEDED HERE. AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF THE BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE 09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL JUST MENTION THE POTNL IN THE HWO AND LET THE DAY SHIFT ISSUE HEADLINES FOR THIS EVENT IF NEEDED. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT. IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE MONDAY NIGHT/TUESDAY. PREVIOUS DISCUSSION... FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS. REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH WEAK HIGH PRESSURE MON AFTN. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... 12Z UPDATE... STRONG COLD FRONT IS JUST FINISHING ITS BLAST THROUGH THE AREA...TAKING THE STEADIER RAIN SHOWERS WITH IT. WINDS WILL HAVE A MUCH EASIER TIME MIXING DOWN IN THE COLD AIR BEHIND THE FRONT...ALLOWING WESTERLY GUSTS FREQUENTLY IN THE 30-40 KT RANGE. GUSTS AT KSYR AND PERHAPS KRME WILL EVEN TOP OUT AROUND 35-45 KTS AT TIMES TODAY. EXPECTING SCT-BKN CLOUD DECK WITH SCT -SHSN AND MVFR CIG FOR SOME TERMINALS. THOUGH GENERALLY VFR TO MVFR IN TAFS TODAY WITH THE SNOW FLURRIES...SOME TERMINALS WILL HAVE TO WATCH FOR BRIEF SURPRISE IFR VIS FROM A HEAVIER LAKE EFFECT SNOW SHOWER. THE MAIN LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME IN OCCASIONAL IFR VIS AFTER 03Z...AND BY 09Z ONWARD FOR KSYR. .OUTLOOK... FRI THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY. SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044- 045-055-056-062. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009- 015>018-022-036-037-046-057. LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST FRIDAY FOR NYZ009. && $$ SYNOPSIS... NEAR TERM...MLJ SHORT TERM... LONG TERM...MDP/TAC AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
651 AM EST THU JAN 31 2013 .SYNOPSIS... COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND WEAK UPPER LEVEL DISTURBANCES. && .NEAR TERM /THROUGH TONIGHT/... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO SIG CHGS TO FCST. PREV BLO... 450 AM...DROPPED FLOOD WATCH FOR THER CNTRL SRN TIER AND PORTIONS OF THE FINGER LAKES AS BACKEDGE OF STEADIER RAIN HAS EXITED THIS RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE 40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO... BACKEDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF 315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL CONTINUE TO MONITOR CAREFULLY. MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE WARNING. SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAILY DUE TO LAKE INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW END ADVISORY IS NEEDED HERE. AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF TEH BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE 09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL JUST MENTION THE POTNL IN THE HWO AND LET THE DAYSHIFT ISSUE HEADLINES FOR THIS EVENT IF NEEDED. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT. IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE MONDAY NIGHT/TUESDAY. PREVIOUS DISCUSSION... FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS. REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH WEAK HIGH PRESSURE MON AFTN. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... 12Z UPDATE... STRONG COLD FRONT IS JUST FINISHING ITS BLAST THROUGH THE AREA...TAKING THE STEADIER RAIN SHOWERS WITH IT. WINDS WILL HAVE A MUCH EASIER TIME MIXING DOWN IN THE COLD AIR BEHIND THE FRONT...ALLOWING WESTERLY GUSTS FREQUENTLY IN THE 30-40 KT RANGE. GUSTS AT KSYR AND PERHAPS KRME WILL EVEN TOP OUT AROUND 35-45 KTS AT TIMES TODAY. EXPECTING SCT-BKN CLOUD DECK WITH SCT -SHSN AND MVFR CIG FOR SOME TERMINALS. THOUGH GENERALLY VFR TO MVFR IN TAFS TODAY WITH THE SNOW FLURRIES...SOME TERMINALS WILL HAVE TO WATCH FOR BRIEF SURPRISE IFR VIS FROM A HEAVIER LAKE EFFECT SNOW SHOWER. THE MAIN LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME IN OCCASIONAL IFR VIS AFTER 03Z...AND BY 09Z ONWARD FOR KSYR. .OUTLOOK... FRI THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY. SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044- 045-055-056-062. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009- 015>018-022-036-037-046-057. LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST FRIDAY FOR NYZ009. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM...MDP/TAC AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
620 AM EST THU JAN 31 2013 .SYNOPSIS... COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND WEAK UPPER LEVEL DISTURBANCES. && .NEAR TERM /THROUGH TONIGHT/... 620 AM...WILL DROP THE FLOOD WATCH FOR ERN ZONES AS STEADY RAIN IS MOVG OUT. OTRW JUST MINOR NEAR TERM TWEEKS WITH NO SIG CHGS TO FCST. PREV BLO... 450 AM...DROPPED FLOOD WATCH FOR THER CNTRL SRN TIER AND PORTIONS OF THE FINGER LAKES AS BACKEDGE OF STEADIER RAIN HAS EXITED THIS RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE 40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO... BACKEDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF 315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL CONTINUE TO MONITOR CAREFULLY. MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE WARNING. SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAILY DUE TO LAKE INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW END ADVISORY IS NEEDED HERE. AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF TEH BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE 09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL JUST MENTION THE POTNL IN THE HWO AND LET THE DAYSHIFT ISSUE HEADLINES FOR THIS EVENT IF NEEDED. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT. IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE MONDAY NIGHT/TUESDAY. PREVIOUS DISCUSSION... FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS. REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH WEAK HIGH PRESSURE MON AFTN. && .AVIATION /11Z THURSDAY THROUGH MONDAY/... 06Z UPDATE... STRONG WET SYSTEM IS PROGRESSING THROUGH THE REGION. SSE WIND AHEAD OF THE FRONT...WITH STRONG SSW FLOW NOT FAR OFF THE SURFACE. FOR KRME AND KAVP...LIKELY MEETING LLWS THRESHOLD AND THUS INCLUDED INITIALLY IN TAFS. HOWEVER...SURFACE WIND WILL ABRUPTLY SHIFT TO SW WITH BRIEF HEAVY SHOWERS AS FRONT PASSES...WITH TIMING AS INDICATED IN TAFS. THOUGH IFR NOT OUT OF QUESTION WITH FRONT...MAINLY MVFR IS ANTICIPATED AND HAS OCCURRED UPSTREAM. BEHIND FRONT...WINDS WILL HAVE A MUCH EASIER TIME MIXING DOWN...MITIGATING ANY FURTHER LLWS BUT ALSO ALLOWING GUSTS FREQUENTLY IN THE 30-40 KT RANGE. KSYR-KRME COULD EVEN GET A BIT HIGHER THAN THAT THIS AFTERNOON. SCT-BKN CLOUD DECK DURING THE DAYTIME HOURS...EVENTUALLY WITH SCT -SHSN AND MVFR CIG FOR SOME TERMINALS. LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME IN OCCASIONAL IFR VIS 00Z-06Z FRIDAY...AND NOT LONG AFTER THAT FOR KSYR. .OUTLOOK... LATE THU NGT THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY. SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY. && .HYDROLOGY... CONSENSUS OF MODEL AND MAN MADE GUID PROGS PUTS 1 TO UP TO 2.5 INCHES WITH THE HEAVIEST RAIN AXIS FURTHER WEST ACROSS THE FINGER LAKES AND CHEMUNG BASINS OF NY. WILL HAVE TWO BATCHES WITH THE INITIAL BATCH ALREADY IN WRN PA AND WRN NY NOW. THIS FIRST BATCH MOVES QUICKLY THROUGH THIS AFTN. RAINFALL THIS AFTN UP TO HALF AN INCH. QUICK RESPONSE ON STREAMS BUT NO FLOODING INITIALLY. THE COLD FRONT WILL COME THROUGH LATE EVE AND EARLY MORNING WITH MORE HEAVY RAIN. ANOTHER QUICK INCH IN LESS THAN 6 HOURS WHICH WILL BE MOSTLY RUNOFF. STREAMS AND RIVERS WILL RESPOND QUICKLY. FLASH FLOODING POSSIBLE...FOLLOWED BY MINOR RIVER FLOODING. FLOOD WATCH CONTINUES FOR ENTIRE CWA STARTING AT 4 PM INTO THURSDAY MORNING. RIVER FLOOD WARNINGS JUST ISSUED FOR WEST BRANCH DELAWARE RIVER AT WALTON TIOUGHNIOGA RIVER AT CORTLAND CHENANGO RIVER AT SHERBURNE SUSQUEHANNA RIVER AT VESTAL SUSQUEHANNA RIVER AT WAVERLY/SAYRE SUSQUEHANNA RIVER AT TOWANDA SUSQUEHANNA RIVER AT MESHOPPEN SUSQUEHANNA RIVER NEAR WILKES-BARRE && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044- 045-055-056-062. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009- 015>018-022-036-037-046-057. LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST FRIDAY FOR NYZ009. && $$ LONG TERM...MDP/TAC AVIATION...MDP HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
454 AM EST THU JAN 31 2013 .SYNOPSIS... COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND WEAK UPPER LEVEL DISTURBANCES. && .NEAR TERM /THROUGH TONIGHT/... 450 AM...DROPPED FLOOD WATCH FOR THER CNTRL SRN TIER AND PORTIONS OF THE FINGER LAKES AS BACKEDGE OF STEADIER RAIN HAS EXITED THIS RGN. MAY STILL SEE SOME MINOR FLOODING DUE TO RUNOFF BUT FLS`S HANDLING THAT. CONVECTIVE FNTL LINE PRODUCED WIND GUSTS IN THE 40-50 MPH RECENTLY AT SYR/BGM. SYNOPTIC SCALE WINDS WILL BE INCRSNG RAPIDLY LATER THIS MRNG ALL AREAS. PREV BLO... BACKEDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF 315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL CONTINUE TO MONITOR CAREFULLY. MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE WARNING. SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAILY DUE TO LAKE INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW END ADVISORY IS NEEDED HERE. AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF TEH BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE 09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL JUST MENTION THE POTNL IN THE HWO AND LET THE DAYSHIFT ISSUE HEADLINES FOR THIS EVENT IF NEEDED. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT. IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE MONDAY NIGHT/TUESDAY. PREVIOUS DISCUSSION... FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS. REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH WEAK HIGH PRESSURE MON AFTN. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... 06Z UPDATE... STRONG WET SYSTEM IS PROGRESSING THROUGH THE REGION. SSE WIND AHEAD OF THE FRONT...WITH STRONG SSW FLOW NOT FAR OFF THE SURFACE. FOR KRME AND KAVP...LIKELY MEETING LLWS THRESHOLD AND THUS INCLUDED INITIALLY IN TAFS. HOWEVER...SURFACE WIND WILL ABRUPTLY SHIFT TO SW WITH BRIEF HEAVY SHOWERS AS FRONT PASSES...WITH TIMING AS INDICATED IN TAFS. THOUGH IFR NOT OUT OF QUESTION WITH FRONT...MAINLY MVFR IS ANTICIPATED AND HAS OCCURRED UPSTREAM. BEHIND FRONT...WINDS WILL HAVE A MUCH EASIER TIME MIXING DOWN...MITIGATING ANY FURTHER LLWS BUT ALSO ALLOWING GUSTS FREQUENTLY IN THE 30-40 KT RANGE. KSYR-KRME COULD EVEN GET A BIT HIGHER THAN THAT THIS AFTERNOON. SCT-BKN CLOUD DECK DURING THE DAYTIME HOURS...EVENTUALLY WITH SCT -SHSN AND MVFR CIG FOR SOME TERMINALS. LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME IN OCCASIONAL IFR VIS 00Z-06Z FRIDAY...AND NOT LONG AFTER THAT FOR KSYR. .OUTLOOK... LATE THU NGT THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY. SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY. && .HYDROLOGY... CONSENSUS OF MODEL AND MAN MADE GUID PROGS PUTS 1 TO UP TO 2.5 INCHES WITH THE HEAVIEST RAIN AXIS FURTHER WEST ACROSS THE FINGER LAKES AND CHEMUNG BASINS OF NY. WILL HAVE TWO BATCHES WITH THE INITIAL BATCH ALREADY IN WRN PA AND WRN NY NOW. THIS FIRST BATCH MOVES QUICKLY THROUGH THIS AFTN. RAINFALL THIS AFTN UP TO HALF AN INCH. QUICK RESPONSE ON STREAMS BUT NO FLOODING INITIALLY. THE COLD FRONT WILL COME THROUGH LATE EVE AND EARLY MORNING WITH MORE HEAVY RAIN. ANOTHER QUICK INCH IN LESS THAN 6 HOURS WHICH WILL BE MOSTLY RUNOFF. STREAMS AND RIVERS WILL RESPOND QUICKLY. FLASH FLOODING POSSIBLE...FOLLOWED BY MINOR RIVER FLOODING. FLOOD WATCH CONTINUES FOR ENTIRE CWA STARTING AT 4 PM INTO THURSDAY MORNING. RIVER FLOOD WARNINGS JUST ISSUED FOR WEST BRANCH DELAWARE RIVER AT WALTON TIOUGHNIOGA RIVER AT CORTLAND CHENANGO RIVER AT SHERBURNE SUSQUEHANNA RIVER AT VESTAL SUSQUEHANNA RIVER AT WAVERLY/SAYRE SUSQUEHANNA RIVER AT TOWANDA SUSQUEHANNA RIVER AT MESHOPPEN SUSQUEHANNA RIVER NEAR WILKES-BARRE && .BGM WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR PAZ039-040-043-044- 047-048-072. WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR NYZ009-018-036-037- 044>046-056-057-062. WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044- 045-055-056-062. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009- 015>018-022-036-037-046-057. LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST FRIDAY FOR NYZ009. && $$ LONG TERM...MDP/TAC AVIATION...MDP HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
332 AM EST THU JAN 31 2013 .SYNOPSIS... COLDER AIR WORKING INTO THE AREA BEHIND A STRONG COLD FRONT WILL PRODUCE STRONG GUSTY WINDS TODAY...IN ADDITION TO LAKE EFFECT SNOWS DOWNWIND OF LAKES ERIE AND ONTARIO. BELOW NORMAL TEMPERATURES AND SCATTERED SHOW SHOWERS WILL CONTINUE INTO THE WEEKEND...DUE TO A COMBINATION OF LAKE EFFECT SNOW SHOWERS AND WEAK UPPER LEVEL DISTURBANCES. && .NEAR TERM /THROUGH TONIGHT/... BACKEDGE OF AREA OF STEADY RAIN AREA MOVING INTO WRN ZONES AS OF 315 AM...CLOSE TO THE PSN OF THE SFC CDFNT...AND WILL CONTINUE IT`S EWD PROGRESS THROUGH THE EARLY MRNG HRS. SOME OF THE RAIN MAY MIX BRIEFLY WITH SNOW BEFORE TAPERING OFF THIS MRNG. FLOOD WATCH REMAINS ON EFFECT...WE HAVE ISSUED SOME FLS`S THUS FAR AND WILL CONTINUE TO MONITOR CAREFULLY. MAIN ISSUE TDA WILL BE THE STRONG WINDS DVLPNG THIS MRNG AND CONTINUING INTO THE AFTN HRS. BASED ON OUR SUSTAINED AND PEAK WIND GRIDS...WE ADDED STEUBEN...YATES AND SENECA COUNTIES INTO THE WARNING. SCATTERED SNOW SHOWERS ARE XPCTD TDA...MAILY DUE TO LAKE INFLUENCES. WE COULD SEE -SHSN OFF LAKE ERIE ACRS PORTIONS OF THE TWIN TIERS THIS AFTN/EVNG. POTNL FOR 2-4 INCHES ACRS PORTIONS OF WRN STEUBEN TNGT. AFTN SHIFT CAN RE-ASSESS AND DETERMINE IF A LOW END ADVISORY IS NEEDED HERE. AS FOR THE NRN ONEIDA LES EVENT...THIS EVENT APPEARS TO BE SIMILAR TO LAST WEEKS. THE ARW PERFORMED WELL IN THAT CASE...AND THIS MRNG`S RUC ALSO SHOWS GOOD AGREEMENT EARLY ON IN THE PD. IT APPEARS THAT THE BAND WILL NOT MAKE A MOVE INTO NRN ONEIDA UNTIL LATE THIS AFTN...PERSISTING OVER THAT AREA TIL ARND 06Z BEFORE DROPPING SWD AS FLOW BCMS MORE WNWLY. AS THIS OCCURS...MESO MDLS SHOW THE BAND OVER LAKE ONTARIO DROPPING TO A PSN NEAR/ALONG THE SRN SHORE OF LAKE ONTARIO LATE TNGT/TWDS DAYBREAK. THIS IS WHAT OCCURRED WITH THE LAST BAND...AND RESULTED IN RAPID WEAKENING OF TEH BAND OVER THE BGM CWA DUE (AT LEAST IN PART) TO THE LOSS OF OVER-LAKE TRAJECTORY. THIS IS ALSO HINTED AT IN THE MESO MDLS FRI MRNG. FOR NOW WE HAVE THE BAND DROPPING SWD INTO ONON/MAD IN THE 09-12Z TIME FRAME...WITH POTNL FOR LOW END ADVISORY ACCUMS MAINLY OVER NW ONON. GIVEN THE NUMEROUS HEADLINES ALREADY IN EFFECT AND THE FACT WE HAVE SOME TIME TO TAKE A CLOSER LOOK AT THIS...WE WILL JUST MENTION THE POTNL IN THE HWO AND LET THE DAYSHIFT ISSUE HEADLINES FOR THIS EVENT IF NEEDED. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... A COUPLE OF CLIPPER-TYPE SYSTEMS WILL AFFECT THIS WEEKEND...WITH SCATTERED SNOW SHOWERS. A MORE WDSPRD AREA OF LGT SNOW COULD DVLP IN THE WARM ADVECTION PTRN AHEAD OF THE CLIPPER APRCHNG SAT NGT. IN GNRL...CHC POPS FOR -SHSN AND BLO NORMAL TEMPS. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... GRIDS WERE ADJUSTED SOME TO ACCOUNT FOR LATEST HPC GUIDANCE AND GFS/ECMWF MODELS. NO BIG CHANGE TO GOING FORECAST OVERALL...BUT I DID UPGRADE POPS INTO LIKELY CATEGORY FOR CENTRAL NY AND AT LEAST HIGHER CHANCE FOR NORTHEAST PA SUNDAY WITH FAIR AGREEMENT ON BEING INVOLVED IN MERGER BETWEEN DEVELOPING COASTAL LOW AND INCOMING NORTHERN STREAM SYSTEM/CLIPPER. COULD EASILY RESULT IN LIGHT COATING OF SNOW. ANOTHER WEAK CLIPPER CONTINUES TO LOOK POSSIBLE MONDAY NIGHT/TUESDAY. PREVIOUS DISCUSSION... FOLLOWED HPC GUIDANCE. MODELS ARE SIMILAR WITH NO LARGE STORMS. REMAIN UNDER A NORTHEAST US UPPER LEVEL TROF. SEASONABLE WEATHER WITH WEAK LOW PRESSURE SYSTEMS FOLLOWED BY LAKE EFFECT. ALL PRECIP WILL BE SNOW WITH HIGHS AROUND 30 AND LOWS IN THE TEENS. THE WEAK SYSTEMS GO THROUGH SUNDAY AND MONDAY NIGHT...WITH LAKE EFFECT ON THE OTHER DAYS. COULD BE A 12 HOUR DRY BREAK BETWEEN SYSTEMS WITH WEAK HIGH PRESSURE MON AFTN. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... 06Z UPDATE... STRONG WET SYSTEM IS PROGRESSING THROUGH THE REGION. SSE WIND AHEAD OF THE FRONT...WITH STRONG SSW FLOW NOT FAR OFF THE SURFACE. FOR KRME AND KAVP...LIKELY MEETING LLWS THRESHOLD AND THUS INCLUDED INITIALLY IN TAFS. HOWEVER...SURFACE WIND WILL ABRUPTLY SHIFT TO SW WITH BRIEF HEAVY SHOWERS AS FRONT PASSES...WITH TIMING AS INDICATED IN TAFS. THOUGH IFR NOT OUT OF QUESTION WITH FRONT...MAINLY MVFR IS ANTICIPATED AND HAS OCCURRED UPSTREAM. BEHIND FRONT...WINDS WILL HAVE A MUCH EASIER TIME MIXING DOWN...MITIGATING ANY FURTHER LLWS BUT ALSO ALLOWING GUSTS FREQUENTLY IN THE 30-40 KT RANGE. KSYR-KRME COULD EVEN GET A BIT HIGHER THAN THAT THIS AFTERNOON. SCT-BKN CLOUD DECK DURING THE DAYTIME HOURS...EVENTUALLY WITH SCT -SHSN AND MVFR CIG FOR SOME TERMINALS. LAKE ONTARIO SNOW BAND WILL AT FIRST DEVELOP NORTH OF THE AREA THIS AFTERNOON...BUT SHOULD EDGE SOUTH ENOUGH TO INVOLVE KRME IN OCCASIONAL IFR VIS 00Z-06Z FRIDAY...AND NOT LONG AFTER THAT FOR KSYR. .OUTLOOK... LATE THU NGT THRU SAT NGT...MVFR-IFR FROM LAKE -SHSN IN CENTRAL NY. SUN...A COLD FRONT WITH POSSIBLE MVFR AND IFR SNOW SUN NGT-MON...MORE MVFR/IFR LAKE -SHSN MAINLY CENTRAL NY. && .HYDROLOGY... CONSENSUS OF MODEL AND MAN MADE GUID PROGS PUTS 1 TO UP TO 2.5 INCHES WITH THE HEAVIEST RAIN AXIS FURTHER WEST ACROSS THE FINGER LAKES AND CHEMUNG BASINS OF NY. WILL HAVE TWO BATCHES WITH THE INITIAL BATCH ALREADY IN WRN PA AND WRN NY NOW. THIS FIRST BATCH MOVES QUICKLY THROUGH THIS AFTN. RAINFALL THIS AFTN UP TO HALF AN INCH. QUICK RESPONSE ON STREAMS BUT NO FLOODING INITIALLY. THE COLD FRONT WILL COME THROUGH LATE EVE AND EARLY MORNING WITH MORE HEAVY RAIN. ANOTHER QUICK INCH IN LESS THAN 6 HOURS WHICH WILL BE MOSTLY RUNOFF. STREAMS AND RIVERS WILL RESPOND QUICKLY. FLASH FLOODING POSSIBLE...FOLLOWED BY MINOR RIVER FLOODING. FLOOD WATCH CONTINUES FOR ENTIRE CWA STARTING AT 4 PM INTO THURSDAY MORNING. RIVER FLOOD WARNINGS JUST ISSUED FOR WEST BRANCH DELAWARE RIVER AT WALTON TIOUGHNIOGA RIVER AT CORTLAND CHENANGO RIVER AT SHERBURNE SUSQUEHANNA RIVER AT VESTAL SUSQUEHANNA RIVER AT WAVERLY/SAYRE SUSQUEHANNA RIVER AT TOWANDA SUSQUEHANNA RIVER AT MESHOPPEN SUSQUEHANNA RIVER NEAR WILKES-BARRE && .BGM WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR PAZ038>040-043-044- 047-048-072. WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...FLOOD WATCH UNTIL 7 AM EST THIS MORNING FOR NYZ009-015>018- 022>025-036-037-044>046-055>057-062. WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ023>025-044- 045-055-056-062. HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009- 015>018-022-036-037-046-057. LAKE EFFECT SNOW WARNING FROM 1 PM THIS AFTERNOON TO 7 AM EST FRIDAY FOR NYZ009. && $$ LONG TERM...MDP/TAC AVIATION...MDP HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1157 PM EST WED JAN 30 2013 .SYNOPSIS... RAIN...HEAVY AT TIMES WILL FALL ACROSS THE REGION TONIGHT AHEAD OF A COLD FRONT THAT WILL SWEEP ACROSS THE REGION WHICH WILL SEND TEMPERATURES BACK TO SEASONAL NORMALS. AS THE COLD AIR DEEPENS ON THURSDAY...LAKE EFFECT SNOWS WILL SET UP IN THE TRADITIONAL SNOWBELTS EAST AND SOUTHEAST OF THE LAKES...THEN WILL CONTINUE THROUGH THE END OF THE WEEK. && .NEAR TERM /THROUGH THURSDAY/... LOW PRESSURE ACROSS LAKE HURON WILL LIFT NORTHEAST ACROSS SOUTHERN ONTARIO OVERNIGHT. THIS WILL BRING A COLD FRONT ACROSS THE REGION TONIGHT...FORECAST TO ENTER FAR WESTERN NEW YORK AROUND MIDNIGHT...THEN SWEEP RAPIDLY TO THE EAST THROUGH THE EARLY MORNING HOURS. THIS WILL CAUSE AN ABRUPT DROP IN TEMPERATURES...AND KEY THE ONSET IN GUSTY WINDS. EXPECT WIND GUSTS WILL PUSH 50 MPH IMMEDIATELY BEHIND THE FRONT...BEFORE THE STEADIER WINDS AHEAD OF A SECONDARY SHOT OF COLDER AIR. IN ADDITION....THIS SYSTEM WILL SET UP A DEEP SOUTHERLY FLOW OUT AHEAD OF IT...WHICH WILL TRANSPORT MOISTURE FROM PENNSYLVANIA AND INTO CENTRAL NEW YORK TONIGHT. A BLEND OF RADAR AND HRRR MODEL GUIDANCE THROUGH 1100 PM SUGGEST THE HEAVIEST RAINS WILL SLIDE A BIT FURTHER EAST...MAINLY IMPACTING LOCATIONS EAST OF LAKE ONTARIO. BECAUSE OF THIS...HAVE MODIFIED THE FLOOD WATCH. REFER TO THE HYDROLOGY SECTION FOR MORE ON THIS. THE SYSTEM WILL CAUSE MULTIPLE ISSUES FOR THE CWA...ORGANIZED BY IMPACT BELOW. 1. STRONG WINDS...THE AFOREMENTIONED STORM SYSTEM WILL DEEPEN FROM AROUND 985MB 00Z TONIGHT TO 970MB 12Z TOMORROW MORNING JUST NORTH OF VERMONT...AND THEN BELOW 960 MB BY 00Z FRIDAY ACROSS EASTERN QUEBEC. THIS RAPID DEEPENING...COMBINED WITH 6 TO 8 MB ISALLOBARIC PRESSURE RISES WITHIN COLD AIR ADVECTION FOLLOWING THE COLD FRONT SHOULD BE ABLE TO MIX A 50 KNOT JET AT 925 HPA DOWN TO THE SURFACE. GIVEN THE STRONG AND VERY DYNAMIC NATURE OF THIS SYSTEM...ITS ASSOCIATED WIND FIELDS WILL ALSO BE QUITE STRONG. WE WILL UPGRADE THE ADVISORY TO A WARNING FOR A GOOD PORTION OF THE CWA. WIND GUSTS UP TO 60 MPH ARE LIKELY IN FAVORED AREAS ALONG THE LAKE ERIE SHORELINE INLAND ACROSS SOUTHERN LAKE ONTARIO AND THROUGH THE EASTERN LAKE ONTARIO REGION. FOR OUR INLAND COUNTIES OF WYOMING...ALLEGANY...LIVINGSTON AND ONTARIO WE WILL LEAVE A HIGH END WIND ADVISORY AS THE DEEPENING LOW MAY BE TOO FAR NORTH TO ALLOW FOR WARNING CRITERIA WINDS HERE. 2. LAKE EFFECT SNOW...FOLLOWING THE PASSAGE OF THE COLD FRONT -14C TO -16C 850 HPA AIR TEMPERATURES WILL BE CROSSING THE LAKES. AT FIRST WINDS MAY BE TO STRONG FOR GOOD FORMATION OF LAKE EFFECT SNOW BANDS WITH THE WINDS SHEARING AWAY THE LAKE BAND FORMATION. ALSO WITH THE STRONG WINDS RESIDENT TIME OVER THE LAKE BODIES WILL BE LIMITED. AS WINDS DIMINISH THROUGH THE AFTERNOON AND COLD AIR DEEPENS...AND LAKE INDUCED EQUILIBRIUM LEVELS RISE TOWARDS 7 TO 9K FEET A BAND OF SNOW SHOULD BE FORMING OFF BOTH LAKE ERIE AND LAKE ONTARIO. THE NAM...AND TO A DEGREE THE GFS HAS DEEP SYNOPTIC MOISTURE REMAINING IN THE SNOW GROWTH ZONE...WHICH WILL BE FALLING WITH THE COLD AIR ADVECTION. OFF LAKE ONTARIO...WIND FIELD CONVERGENCE OVER LAKE ONTARIO IS LEADING TO IMPRESSIVE OMEGA FIELDS BY THURSDAY AFTERNOON WHERE A BAND OF LAKE EFFECT SNOW MAY BEGIN TO PRODUCE SNOWFALL RATES UP TO 2 INCHES PER HOUR. FOLLOWING THE SURFACE LOW AND UPPER LEVEL TROUGH WINDS WILL BEGIN TO VEER THROUGH THE DAY DROPPING THE LAKE EFFECT SNOW BAND SOUTH OF JEFFERSON COUNTY. FOR THIS REASON WILL LEAVE JEFFERSON COUNTY AS A HIGH END LAKE EFFECT SNOW ADVISORY...AND HAVE WARNINGS FOR LEWIS AND OSWEGO COUNTIES WHERE THE BAND WILL LIKELY FALL LONGER. OFF LAKE ERIE...A WESTERLY FLOW OVER THE STILL OPEN WATERS OF LAKE ERIE WILL BRING MULTI BANDED STRUCTURE SNOW BANDS ACROSS THE SOUTHERN TIER. CONFIDENCE IS GREATER ACROSS CHAUTAUQUA AND CATTARAUGUS COUNTIES THAN SOUTHERN ERIE AND WYOMING COUNTIES FOR WARNING CRITERIA SNOW. WILL UPGRADE THE WATCH TO A LAKE EFFECT WARNING ACROSS THE SOUTHERN TIER...WHILE LEAVING ADVISORIES FOR SOUTHERN TIER AND WYOMING COUNTIES. 3. REGARDING TEMPERATURES...RECORDED HIGHS WERE SHATTERED ACROSS MUCH OF THE REGION TODAY WITH MORNING AND EARLY AFTERNOON HIGHS REACHING NEAR 10 DEGREES ABOVE RECORD VALUES FOR THE DATE. THE NEW RECORDS FOR TODAY... BUFFALO.....66 (PREVIOUS WAS 56 IN 1916) ROCHESTER...64 (PREVIOUS WAS 55 IN 1974) WATERTOWN...63 (PREVIOUS WAS 52 IN 1995) THESE READINGS ARE STILL SEVERAL DEGREES SHY OF THE ALLTIME MONTHLY RECORD HIGH TEMPERATURE WHICH ARE AS FOLLOWS: BUFFALO.....72 IN 1950. ROCHESTER...74 IN 1950...CORRECTED WATERTOWN...66 IN 1995. THE COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT SENDING TEMPERATURES BACK TO SEASONAL NORMS...WITH MANY AREAS DOWN INTO THE UPPER 20S AND LOW 30S BY TOMORROW MORNING. WITH THE RAIN OVERNIGHT THE PROSPECTS FOR BLACK ICE WILL BE PRESENT AS WE QUICKLY COOL FURTHER INTO THE MID AND UPPER 20S BY MID MORNING. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... HEAVY LAKE EFFECT SNOWS SHOULD BE ONGOING ON A WESTERLY FLOW REGIME AT THE START OF THE PERIOD. BUFR PROFILES FROM THURSDAY NIGHT THROUGH AT LEAST THE DAYTIME HOURS OF FRIDAY CONTINUE TO LOOK RATHER IMPRESSIVE...AS A DEEP LAYERED CYCLONIC FLOW REGIME IS WELL ESTABLISHED. MOISTURE PROFILES LOOK QUITE ADEQUATE WITH SATURATION WELL UP THROUGH 10K FEET AND DEEPER AT TIMES AS A COUPLE OF REINFORCING WEAK SHORTWAVES WORK THROUGH THE MEAN WEST NORTHWEST FLOW. THE BIGGEST FACTOR THAT COULD LIMIT TOTALS WILL BE THE VEERING WINDS IN RESPONSE TO A SHORTWAVE CROSSING THE LOWER LAKES. THIS WILL TEND TO PUSH THE LAKE BANDS...ESPECIALLY ACROSS LAKE ONTARIO SOUTHWARD. THIS COULD BRING THE PRIME LAKE EFFECT FOCUS ALONG THE SOUTH SHORE OF LAKE ONTARIO...WHICH COULD BRING AT LEAST ADVISORY OR GREATER TOTALS TO THIS AREA INCLUDING THE ROCHESTER METRO AREA. FEEL A BIT MORE CONFIDENT WITH THE AREA FROM WAYNE OVER TO NORTHERN CAYUGA AT THIS POINT...THEREFORE WILL ISSUE A LAKE EFFECT SNOW WATCH FOR THAT AREA...BUT IT IS HIGHLY POSSIBLE THAT LAKE EFFECT HEADLINES MAY NEED TO BE ISSUED FARTHER TO THE WEST. ANOTHER SHORTWAVE APPROACHING THE REGION FRIDAY NIGHT AND SATURDAY MAY REORIENT THE LAKES SNOWS FOR A TIME NORTHWARD AS THE FLOW BACKS TO WEST SOUTHWEST...POTENTIALLY BRINGING SOME ACCUMULATING SNOWS INTO PORTIONS OF THE BUFFALO METRO AND WATERTOWN AREAS. THE PASSAGE OF THE SHORTWAVE SHOULD RE-ESTABLISH THE LAKE SNOWS BACK SOUTHWARD LATER SATURDAY AND SATURDAY NIGHT. MUCH COLDER AIR MASS ACROSS THE AREA FRIDAY AND SATURDAY WITH DAYTIME HIGHS IN THE TEENS AND 20S...WITH WIND CHILLS PERIODICALLY BELOW ZERO. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... THE VERY COLD AIR REMAINS IN PLACE SUNDAY...BEFORE A GRADUAL MODIFICATION OF THE AIR MASS OCCURS INTO EARLY NEXT WEEK AS THE UPPER TROUGH SHIFTS TO THE EAST. TWO CLIPPER TYPE WAVES LOOK TO IMPACT THE LOWER LAKES REGION DURING THIS TIME FRAME. ONE WAVE MOVES THROUGH ON SUNDAY WHICH MAY SERVE TO ENHANCE THE ONGOING LAKE EFFECT SNOWS IN A WESTERLY FLOW REGIME. THE SECOND WAVE LOOKS TO MOVE THROUGH LATE MONDAY OR EARLY TUESDAY AND APPEARS TO BE RATHER ROBUST AND GIVEN THE PROJECTED TRACK OF THE ASSOCIATED SURFACE LOW COULD BRING THE POTENTIAL FOR A GENERAL WIDESPREAD SEVERAL INCHES OF SNOW. BEHIND THIS WAKE A COLDER FLOW DEVELOPS WHICH MAY REDEVELOP SOME LAKE SNOWS BUT LACK OF SIGNIFICANT MOISTURE COULD LIMIT SNOWFALL POTENTIAL. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... A COLD FRONT ACROSS BUF/IAG/JHW AT 06Z WILL RACE TO THE EAST...REACHING ART AROUND 09Z. THIS FRONT WILL TRIGGER AN ABRUPT INCREASE IN WINDS...WHICH WILL LAST THROUGH MUCH OF THE DAY...BEFORE TAPERING OFF LATE THURSDAY AFTERNOON. MEANWHILE...RAIN SHOWER AHEAD OF THE FRONT WILL CONTINUE TO SLIDE EAST DURING THE EARLY MORNING HOURS. TEMPERATURES WILL COOL BEHIND THE FRONT...WHICH WILL SET UP LAKE SNOWS EAST OF THE LAKES. THESE SHOULD LARGELY MISS BUF/IAG/ROC FOR MOST OF TODAY AND THIS EVENING. LAKE SNOWS WILL PROBABLY IMPACT JHW/ART FOR A PERIOD...WITH IFR OR LOWER CONDITIONS POSSIBLE. OUTLOOK... THURSDAY NIGHT THROUGH SATURDAY...MVFR WITH LOCALIZED IFR IN LAKE EFFECT SNOW EAST OF THE LAKES. SUNDAY...MAINLY VFR WITH MVFR IN LOCALIZED LAKE EFFECT SNOW SHOWERS. MONDAY...VFR. && .MARINE... A COMPLEX AREA OF LOW PRESSURE FROM SOUTHERN CANADA AND THROUGH THE CENTRAL GREAT LAKES REGION THIS AFTERNOON WILL LIFT NORTHEASTWARD AND DEEPEN TONIGHT AND TOMORROW. A COLD FRONT SWINGING ACROSS THE LAKES...COUPLED WITH STRONG COLD AIR ADVECTION AND RAPID DEEPENING OF THE SURFACE LOW WILL INCREASE WINDS QUICKLY TO GALE FORCE FOLLOWING THE PASSAGE OF THE FRONT TONIGHT...WITH GALES THEN CONTINUING THROUGH MUCH OF THURSDAY. FOR THIS REASON...GALE WARNINGS WILL CONTINUE AS OUTLINED ON THE LAKES. WINDS AND WAVES WILL STILL REMAIN STRONG THURSDAY EVENING THROUGH SATURDAY...BEFORE DIMINISHING TO BELOW SMALL CRAFT CONDITIONS BY SATURDAY NIGHT. && .HYDROLOGY... FOLLOWING A BLEND OF RADAR AND NEAR TERM GUIDANCE...IT APPEARS THE STEADIEST RAINS WILL FALL EAST OF LAKE ONTARIO...WITH LESSER AMOUNTS WEST OF THE GENESEE RIVER. EAST OF LAKE ONTARIO...EXPECT AROUND AN INCH OF RAIN TO FALL...WITH LESS THAN THAT WEST OF THE GENESEE. LATEST RFC FORECASTS HAVE LOWERED CRESTS AT WELLSVILLE...WITH THE MAJORITY OF MMEFS GUIDANCE KEEPING THE BUFFALO CREEKS...GENESEE RIVER...AND ALLEGHENY RIVER BELOW FLOOD STAGE. THERE STILL MAY BE A FEW LINGERING ICE JAMS IN TYPICALLY FLOOD PRONE AREAS IN PARTS OF CHAUTAUQUA COUNTY. THERE STILL A THREAT FOR FLOODING IN EASTERN PORTIONS...WHERE AN INCH OF RAINFALL STILL APPEARS LIKELY. LOCALLY HIGHER AMOUNTS FROM CONVECTION AND/OR UPSLOPING MAY ALSO OCCUR. THIS COMBINED WITH SNOW MELT FROM LOCATIONS EAST OF LAKE ONTARIO WILL RESULT IN SIGNIFICANT RISES IN THE RIVERS AND CREEKS. AN INCH OF RAIN IS STILL MARGINAL TO CAUSE FLOODING...BUT WITH SNOW MELT QUITE DIFFICULT TO FORECAST...AND SOME ICE JAMS POSSIBLE...THERE IS A CONTINUED RISK OF FLOODING. THE SREF AND TO A LESSER EXTENT GFS/GGEM BASED MMEFS ENSEMBLES POINT TO THIS POTENTIAL. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...HIGH WIND WARNING UNTIL 4 PM EST THURSDAY FOR NYZ001>008-010- 011-019-020-085. LAKE EFFECT SNOW ADVISORY FROM 10 AM THURSDAY TO 6 PM EST FRIDAY FOR NYZ012-085. LAKE EFFECT SNOW ADVISORY FROM 10 AM THURSDAY TO 1 AM EST FRIDAY FOR NYZ007. FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR NYZ004>008-014. LAKE EFFECT SNOW WARNING FROM 10 AM THURSDAY TO 6 PM EST FRIDAY FOR NYZ006-008-019-020. LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH FRIDAY AFTERNOON FOR NYZ004-005. WIND ADVISORY UNTIL 4 PM EST THURSDAY FOR NYZ012>014-021. MARINE...GALE WARNING UNTIL 4 PM EST THURSDAY FOR LEZ040-041. GALE WARNING UNTIL 10 AM EST THURSDAY FOR LEZ020. SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR LOZ030. GALE WARNING UNTIL 4 PM EST THURSDAY FOR LOZ042>045- 062>065. && $$ SYNOPSIS...THOMAS NEAR TERM...APFFEL/THOMAS SHORT TERM...TMA LONG TERM...TMA AVIATION...APFFEL MARINE...APFFEL/THOMAS HYDROLOGY...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1112 PM EST WED JAN 30 2013 .SYNOPSIS... RAIN...HEAVY AT TIMES WILL FALL ACROSS THE REGION TONIGHT AHEAD OF A COLD FRONT THAT WILL SWEEP ACROSS THE REGION WHICH WILL SEND TEMPERATURES BACK TO SEASONAL NORMALS. AS THE COLD AIR DEEPENS ON THURSDAY...LAKE EFFECT SNOWS WILL SET UP IN THE TRADITIONAL SNOWBELTS EAST AND SOUTHEAST OF THE LAKES...THEN WILL CONTINUE THROUGH THE END OF THE WEEK. && .NEAR TERM /THROUGH THURSDAY/... LOW PRESSURE ACROSS LAKE HURON WILL LIFT NORTHEAST ACROSS SOUTHERN ONTARIO OVERNIGHT. THIS WILL BRING A COLD FRONT ACROSS THE REGION TONIGHT...FORECAST TO ENTER FAR WESTERN NEW YORK AROUND MIDNIGHT...THEN SWEEP RAPIDLY TO THE EAST THROUGH THE EARLY MORNING HOURS. THIS WILL CAUSE AN ABRUPT DROP IN TEMPERATURES...AND KEY THE ONSET IN GUSTY WINDS. EXPECT WIND GUSTS WILL PUSH 50 MPH IMMEDIATELY BEHIND THE FRONT...BEFORE THE STEADIER WINDS AHEAD OF A SECONDARY SHOT OF COLDER AIR. IN ADDITION....THIS SYSTEM WILL SET UP A DEEP SOUTHERLY FLOW OUT AHEAD OF IT...WHICH WILL TRANSPORT MOISTURE FROM PENNSYLVANIA AND INTO CENTRAL NEW YORK TONIGHT. A BLEND OF RADAR AND HRRR MODEL GUIDANCE THROUGH 1100 PM SUGGEST THE HEAVIEST RAINS WILL SLIDE A BIT FURTHER EAST...MAINLY IMPACTING LOCATIONS EAST OF LAKE ONTARIO. BECAUSE OF THIS...HAVE MODIFIED THE FLOOD WATCH. REFER TO THE HYDROLOGY SECTION FOR MORE ON THIS. THE SYSTEM WILL CAUSE MULTIPLE ISSUES FOR THE CWA...ORGANIZED BY IMPACT BELOW. 1. STRONG WINDS...THE AFOREMENTIONED STORM SYSTEM WILL DEEPEN FROM AROUND 985MB 00Z TONIGHT TO 970MB 12Z TOMORROW MORNING JUST NORTH OF VERMONT...AND THEN BELOW 960 MB BY 00Z FRIDAY ACROSS EASTERN QUEBEC. THIS RAPID DEEPENING...COMBINED WITH 6 TO 8 MB ISALLOBARIC PRESSURE RISES WITHIN COLD AIR ADVECTION FOLLOWING THE COLD FRONT SHOULD BE ABLE TO MIX A 50 KNOT JET AT 925 HPA DOWN TO THE SURFACE. GIVEN THE STRONG AND VERY DYNAMIC NATURE OF THIS SYSTEM...ITS ASSOCIATED WIND FIELDS WILL ALSO BE QUITE STRONG. WE WILL UPGRADE THE ADVISORY TO A WARNING FOR A GOOD PORTION OF THE CWA. WIND GUSTS UP TO 60 MPH ARE LIKELY IN FAVORED AREAS ALONG THE LAKE ERIE SHORELINE INLAND ACROSS SOUTHERN LAKE ONTARIO AND THROUGH THE EASTERN LAKE ONTARIO REGION. FOR OUR INLAND COUNTIES OF WYOMING...ALLEGANY...LIVINGSTON AND ONTARIO WE WILL LEAVE A HIGH END WIND ADVISORY AS THE DEEPENING LOW MAY BE TOO FAR NORTH TO ALLOW FOR WARNING CRITERIA WINDS HERE. 2. LAKE EFFECT SNOW...FOLLOWING THE PASSAGE OF THE COLD FRONT -14C TO -16C 850 HPA AIR TEMPERATURES WILL BE CROSSING THE LAKES. AT FIRST WINDS MAY BE TO STRONG FOR GOOD FORMATION OF LAKE EFFECT SNOW BANDS WITH THE WINDS SHEARING AWAY THE LAKE BAND FORMATION. ALSO WITH THE STRONG WINDS RESIDENT TIME OVER THE LAKE BODIES WILL BE LIMITED. AS WINDS DIMINISH THROUGH THE AFTERNOON AND COLD AIR DEEPENS...AND LAKE INDUCED EQUILIBRIUM LEVELS RISE TOWARDS 7 TO 9K FEET A BAND OF SNOW SHOULD BE FORMING OFF BOTH LAKE ERIE AND LAKE ONTARIO. THE NAM...AND TO A DEGREE THE GFS HAS DEEP SYNOPTIC MOISTURE REMAINING IN THE SNOW GROWTH ZONE...WHICH WILL BE FALLING WITH THE COLD AIR ADVECTION. OFF LAKE ONTARIO...WIND FIELD CONVERGENCE OVER LAKE ONTARIO IS LEADING TO IMPRESSIVE OMEGA FIELDS BY THURSDAY AFTERNOON WHERE A BAND OF LAKE EFFECT SNOW MAY BEGIN TO PRODUCE SNOWFALL RATES UP TO 2 INCHES PER HOUR. FOLLOWING THE SURFACE LOW AND UPPER LEVEL TROUGH WINDS WILL BEGIN TO VEER THROUGH THE DAY DROPPING THE LAKE EFFECT SNOW BAND SOUTH OF JEFFERSON COUNTY. FOR THIS REASON WILL LEAVE JEFFERSON COUNTY AS A HIGH END LAKE EFFECT SNOW ADVISORY...AND HAVE WARNINGS FOR LEWIS AND OSWEGO COUNTIES WHERE THE BAND WILL LIKELY FALL LONGER. OFF LAKE ERIE...A WESTERLY FLOW OVER THE STILL OPEN WATERS OF LAKE ERIE WILL BRING MULTI BANDED STRUCTURE SNOW BANDS ACROSS THE SOUTHERN TIER. CONFIDENCE IS GREATER ACROSS CHAUTAUQUA AND CATTARAUGUS COUNTIES THAN SOUTHERN ERIE AND WYOMING COUNTIES FOR WARNING CRITERIA SNOW. WILL UPGRADE THE WATCH TO A LAKE EFFECT WARNING ACROSS THE SOUTHERN TIER...WHILE LEAVING ADVISORIES FOR SOUTHERN TIER AND WYOMING COUNTIES. 3. REGARDING TEMPERATURES...RECORDED HIGHS WERE SHATTERED ACROSS MUCH OF THE REGION TODAY WITH MORNING AND EARLY AFTERNOON HIGHS REACHING NEAR 10 DEGREES ABOVE RECORD VALUES FOR THE DATE. THE NEW RECORDS FOR TODAY... BUFFALO.....66 (PREVIOUS WAS 56 IN 1916) ROCHESTER...64 (PREVIOUS WAS 55 IN 1974) WATERTOWN...63 (PREVIOUS WAS 52 IN 1995) THESE READINGS ARE STILL SEVERAL DEGREES SHY OF THE ALLTIME MONTHLY RECORD HIGH TEMPERATURE WHICH ARE AS FOLLOWS: BUFFALO.....72 IN 1950. ROCHESTER...74 IN 1950...CORRECTED WATERTOWN...66 IN 1995. THE COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT SENDING TEMPERATURES BACK TO SEASONAL NORMS...WITH MANY AREAS DOWN INTO THE UPPER 20S AND LOW 30S BY TOMORROW MORNING. WITH THE RAIN OVERNIGHT THE PROSPECTS FOR BLACK ICE WILL BE PRESENT AS WE QUICKLY COOL FURTHER INTO THE MID AND UPPER 20S BY MID MORNING. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... HEAVY LAKE EFFECT SNOWS SHOULD BE ONGOING ON A WESTERLY FLOW REGIME AT THE START OF THE PERIOD. BUFR PROFILES FROM THURSDAY NIGHT THROUGH AT LEAST THE DAYTIME HOURS OF FRIDAY CONTINUE TO LOOK RATHER IMPRESSIVE...AS A DEEP LAYERED CYCLONIC FLOW REGIME IS WELL ESTABLISHED. MOISTURE PROFILES LOOK QUITE ADEQUATE WITH SATURATION WELL UP THROUGH 10K FEET AND DEEPER AT TIMES AS A COUPLE OF REINFORCING WEAK SHORTWAVES WORK THROUGH THE MEAN WEST NORTHWEST FLOW. THE BIGGEST FACTOR THAT COULD LIMIT TOTALS WILL BE THE VEERING WINDS IN RESPONSE TO A SHORTWAVE CROSSING THE LOWER LAKES. THIS WILL TEND TO PUSH THE LAKE BANDS...ESPECIALLY ACROSS LAKE ONTARIO SOUTHWARD. THIS COULD BRING THE PRIME LAKE EFFECT FOCUS ALONG THE SOUTH SHORE OF LAKE ONTARIO...WHICH COULD BRING AT LEAST ADVISORY OR GREATER TOTALS TO THIS AREA INCLUDING THE ROCHESTER METRO AREA. FEEL A BIT MORE CONFIDENT WITH THE AREA FROM WAYNE OVER TO NORTHERN CAYUGA AT THIS POINT...THEREFORE WILL ISSUE A LAKE EFFECT SNOW WATCH FOR THAT AREA...BUT IT IS HIGHLY POSSIBLE THAT LAKE EFFECT HEADLINES MAY NEED TO BE ISSUED FARTHER TO THE WEST. ANOTHER SHORTWAVE APPROACHING THE REGION FRIDAY NIGHT AND SATURDAY MAY REORIENT THE LAKES SNOWS FOR A TIME NORTHWARD AS THE FLOW BACKS TO WEST SOUTHWEST...POTENTIALLY BRINGING SOME ACCUMULATING SNOWS INTO PORTIONS OF THE BUFFALO METRO AND WATERTOWN AREAS. THE PASSAGE OF THE SHORTWAVE SHOULD RE-ESTABLISH THE LAKE SNOWS BACK SOUTHWARD LATER SATURDAY AND SATURDAY NIGHT. MUCH COLDER AIR MASS ACROSS THE AREA FRIDAY AND SATURDAY WITH DAYTIME HIGHS IN THE TEENS AND 20S...WITH WIND CHILLS PERIODICALLY BELOW ZERO. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... THE VERY COLD AIR REMAINS IN PLACE SUNDAY...BEFORE A GRADUAL MODIFICATION OF THE AIR MASS OCCURS INTO EARLY NEXT WEEK AS THE UPPER TROUGH SHIFTS TO THE EAST. TWO CLIPPER TYPE WAVES LOOK TO IMPACT THE LOWER LAKES REGION DURING THIS TIME FRAME. ONE WAVE MOVES THROUGH ON SUNDAY WHICH MAY SERVE TO ENHANCE THE ONGOING LAKE EFFECT SNOWS IN A WESTERLY FLOW REGIME. THE SECOND WAVE LOOKS TO MOVE THROUGH LATE MONDAY OR EARLY TUESDAY AND APPEARS TO BE RATHER ROBUST AND GIVEN THE PROJECTED TRACK OF THE ASSOCIATED SURFACE LOW COULD BRING THE POTENTIAL FOR A GENERAL WIDESPREAD SEVERAL INCHES OF SNOW. BEHIND THIS WAKE A COLDER FLOW DEVELOPS WHICH MAY REDEVELOP SOME LAKE SNOWS BUT LACK OF SIGNIFICANT MOISTURE COULD LIMIT SNOWFALL POTENTIAL. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... A BROAD AREA OF SHOWERS WILL MOVE INTO THE REGION...BOTH STREAMING FROM THE SOUTH AND AHEAD OF A COLD FRONT. THIS WILL BRING A PERIOD OF RAIN TO ALL TAF SITES...BUT WITH THE SOUTHERLY DOWNSLOPE COMPONENT TO THE FLOW CIGS WILL BE INITIALLY SLOW TO DROP. AS THE COLD FRONT CROSS THE AREA BETWEEN 04Z AND 09Z...CIGS WILL DROP AND IFR CONDITIONS WILL BECOME MORE WIDESPREAD...ESPECIALLY DOWNWIND OF THE LAKES. RAIN WILL MIX WITH...THEN CHANGE TO SNOW BEFORE DAYBREAK THURSDAY. STRONG COLD AIR ADVECTION BEHIND THE DEPARTING FRONT WILL INCREASE MIXING AND RAPIDLY STRENGTHEN WESTERLY WINDS OVERNIGHT. LATE TONIGHT INTO THURSDAY MORNING...EXPECT WINDS TO GUST TO 40-50 KNOTS IN MOST LOCATIONS...BEFORE TAPERING OFF LATE THURSDAY AFTERNOON. LAKE SNOWS WILL DEVELOP EAST OF THE LAKES. THESE WILL LIKELY STAY OUT OF BUF/IAG/ROC...BUT SHOULD IMPACT ART/JHW FOR A PERIOD. CONDITIONS WILL VARY SIGNIFICANTLY IN AND OUT OF LAKE EFFECT BANDS. OUTLOOK... THURSDAY NIGHT THROUGH SATURDAY...MVFR WITH LOCALIZED IFR IN LAKE EFFECT SNOW EAST OF THE LAKES. SUNDAY...MAINLY VFR WITH MVFR IN LOCALIZED LAKE EFFECT SNOW SHOWERS. MONDAY...VFR. && .MARINE... A COMPLEX AREA OF LOW PRESSURE FROM SOUTHERN CANADA AND THROUGH THE CENTRAL GREAT LAKES REGION THIS AFTERNOON WILL LIFT NORTHEASTWARD AND DEEPEN TONIGHT AND TOMORROW. A COLD FRONT SWINGING ACROSS THE LAKES...COUPLED WITH STRONG COLD AIR ADVECTION AND RAPID DEEPENING OF THE SURFACE LOW WILL INCREASE WINDS QUICKLY TO GALE FORCE FOLLOWING THE PASSAGE OF THE FRONT TONIGHT...WITH GALES THEN CONTINUING THROUGH MUCH OF THURSDAY. FOR THIS REASON...GALE WARNINGS WILL CONTINUE AS OUTLINED ON THE LAKES. WINDS AND WAVES WILL STILL REMAIN STRONG THURSDAY EVENING THROUGH SATURDAY...BEFORE DIMINISHING TO BELOW SMALL CRAFT CONDITIONS BY SATURDAY NIGHT. && .HYDROLOGY... FOLLOWING A BLEND OF RADAR AND NEAR TERM GUIDANCE...IT APPEARS THE STEADIEST RAINS WILL FALL EAST OF LAKE ONTARIO...WITH LESSER AMOUNTS WEST OF THE GENESEE RIVER. EAST OF LAKE ONTARIO...EXPECT AROUND AN INCH OF RAIN TO FALL...WITH LESS THAN THAT WEST OF THE GENESEE. LATEST RFC FORECASTS HAVE LOWERED CRESTS AT WELLSVILLE...WITH THE MAJORITY OF MMEFS GUIDANCE KEEPING THE BUFFALO CREEKS...GENESEE RIVER...AND ALLEGHENY RIVER BELOW FLOOD STAGE. THERE STILL MAY BE A FEW LINGERING ICE JAMS IN TYPICALLY FLOOD PRONE AREAS IN PARTS OF CHAUTAUQUA COUNTY. THERE STILL A THREAT FOR FLOODING IN EASTERN PORTIONS...WHERE AN INCH OF RAINFALL STILL APPEARS LIKELY. LOCALLY HIGHER AMOUNTS FROM CONVECTION AND/OR UPSLOPING MAY ALSO OCCUR. THIS COMBINED WITH SNOW MELT FROM LOCATIONS EAST OF LAKE ONTARIO WILL RESULT IN SIGNIFICANT RISES IN THE RIVERS AND CREEKS. AN INCH OF RAIN IS STILL MARGINAL TO CAUSE FLOODING...BUT WITH SNOW MELT QUITE DIFFICULT TO FORECAST...AND SOME ICE JAMS POSSIBLE...THERE IS A CONTINUED RISK OF FLOODING. THE SREF AND TO A LESSER EXTENT GFS/GGEM BASED MMEFS ENSEMBLES POINT TO THIS POTENTIAL. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...HIGH WIND WARNING UNTIL 4 PM EST THURSDAY FOR NYZ001>008-010- 011-019-020-085. LAKE EFFECT SNOW ADVISORY FROM 10 AM THURSDAY TO 6 PM EST FRIDAY FOR NYZ012-085. LAKE EFFECT SNOW ADVISORY FROM 10 AM THURSDAY TO 1 AM EST FRIDAY FOR NYZ007. FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR NYZ004>008-014. LAKE EFFECT SNOW WARNING FROM 10 AM THURSDAY TO 6 PM EST FRIDAY FOR NYZ006-008-019-020. LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH FRIDAY AFTERNOON FOR NYZ004-005. WIND ADVISORY UNTIL 4 PM EST THURSDAY FOR NYZ012>014-021. MARINE...GALE WARNING UNTIL 4 PM EST THURSDAY FOR LEZ040-041. GALE WARNING UNTIL 10 AM EST THURSDAY FOR LEZ020. SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR LOZ030. GALE WARNING UNTIL 4 PM EST THURSDAY FOR LOZ042>045- 062>065. && $$ SYNOPSIS...THOMAS NEAR TERM...APFFEL/THOMAS SHORT TERM...TMA LONG TERM...TMA AVIATION...APFFEL MARINE...APFFEL/THOMAS HYDROLOGY...APFFEL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1208 PM EST THU JAN 31 2013 .SYNOPSIS... COOL HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...WITH BELOW NORMAL TEMPERATURES EXPECTED. IT WILL BE BREEZY TODAY... ALTHOUGH WINDS WILL NOT BE AS STRONG AS LAST NIGHT. A SERIES OF DRY COLD FRONTS WILL MOVE ACROSS THE AREA. THE FIRST FRONT WILL CROSS THE AREA FRIDAY FOLLOWED BY ANOTHER ON SUNDAY AND YET ANOTHER ON TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 AM THURSDAY...NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST. TEMPERATURES ARE SLOW TO RISE AS EXPECTED BUT ARE FOLLOWING THE HOURLY CURVE DERIVED FROM A NAM/RUC BLEND WITHIN +/-1 DEGREE. NO CHANGES ARE NEEDED. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS... THE SEASONS HAVE CHANGED YET AGAIN WITH YESTERDAY`S SPRING-LIKE WEATHER REPLACED BY A RETURN TO WINTER TODAY. COLD ADVECTION ON WESTERLY WINDS BEHIND LAST NIGHT`S STRONG COLD FRONT WILL ALMOST PERFECTLY BALANCE NEARLY FULL SUNSHINE TODAY AND TEMPERATURES WILL STRUGGLE JUST TO RISE A FEW DEGREES BY AFTERNOON...REACHING 53-56 DEGREES AREAWIDE. THE 12Z GSO SOUNDING WAS BEST SIMULATED BY THE 12Z NAM AND RUC MODELS...AND THESE ARE THE TWO MODELS I BLENDED FOR MY UPDATED FORECAST TODAY. DOWNWARD REVISIONS HAVE BEEN MADE TO DEWPOINT FORECASTS FOR THE AFTERNOON HOURS WITH LOWER 20S DEWPOINTS EXPECTED TO MIX DOWN FROM A RESERVOIR OF VERY DRY AIR ALOFT. PRECIPITABLE WATER VALUES TODAY SHOULD RANGE FROM 0.20 TO 0.25 INCHES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 AM THURSDAY...SHORTWAVE ROUNDING BASE OF MID LEVEL TROUGH EARLY FRI HELPS DRIVE A REINFORCING SHOT OF COLD AIR INTO THE REGION. DRY COLD FRONT PUSHES OFFSHORE BY MIDDAY WITH A PERIOD OF BRIEF BUT STRONG COLD ADVECTION ENDING LATE FRI NIGHT. TEMP DROP WILL BE SIGNIFICANT WITH GUIDANCE SHOWING 850 TEMPS DECREASING BY AS MUCH AS 10C IN SOME PLACES IN UNDER 12 HOURS. DEEP WEST TO NORTHWEST FLOW FRI INTO FRI NIGHT HELPS KEEP SKIES CLEAR. PATTERN BECOMES LESS AMPLIFIED AND MORE PROGRESSIVE LATE FRI NIGHT...SHUTTING OFF COLD ADVECTION. MORE PROGRESSIVE EVOLUTION OF MID LEVEL PATTERN HELPS MOVE CENTER OF SURFACE RIDGE AXIS OVER THE REGION FOR SAT MORNING...ALLOWING FOR SOME RADIATIONAL COOLING. DO NOT ANTICIPATE EFFECT TO BE VERY STRONG BUT TYPICAL COLD SPOTS WILL FLIRT WITH TEENS FOR LOWS. HIGHS FRI WILL STRUGGLE TO REACH CLIMO WHILE LOWS WILL DROP INTO THE LOW TO MID 20S IN MOST AREAS SAT MORNING. SURFACE RIDGE AXIS SHIFTS OFFSHORE SAT WITH WEAK RETURN FLOW SETTING UP FOR THE END OF THE PERIOD. ALOFT ANOTHER SHORTWAVE HELPS AMPLIFY THE MID LEVEL PATTERN...RESULTING IN A SHORT PERIOD OF DEEP WEST-SOUTHWEST FLOW AHEAD OF ANOTHER COLD FRONT MOVING INTO THE REGION AS THE PERIOD ENDS. ANTICIPATE AN INCREASE IN MID AND UPPER LEVEL CLOUD ASSOCIATED WITH THIS WAVE BUT DURATION OF RETURN FLOW IS NOT ENOUGH TO BRING SIGNIFICANT MOISTURE BACK INTO THE REGION BEFORE THE FRONT PASSES. ALTHOUGH SOME GUIDANCE IS POINTING TO SOME LIGHT ISOLATED PRECIP EARLY SUN MORNING DO NOT THINK THIS WILL BE THE CASE. WILL MAINTAIN A POP FORECAST AROUND 10 SAT NIGHT. TEMPERATURES REMAIN BELOW CLIMO SAT BUT END UP MUCH CLOSER TO CLIMO SAT NIGHT. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 3 AM THURSDAY...A RATHER REPETITIVE PATTERN FOR THE EXTENDED AS AREAS OF HIGH PRESSURE PUSH OFFSHORE AHEAD OF A SERIES OF WEAK COLD FRONTS. FIRST COLD FRONT WILL CROSS THE AREA VERY EARLY SUNDAY MORNING. LIMITED FORCING COMBINED WITH ONLY MARGINAL PWATS SUGGESTS FROPA WILL BE DRY...AND ONLY ACT TO REINFORCE THE COOL AIR. HOWEVER...ANY WEAK CAA REMAINS WELL DISPLACED BEHIND THE FRONT...SO SUNDAY WILL END UP BEING WARMER THAN SATURDAY...ALTHOUGH BOTH DAYS WILL BE AROUND TO SLIGHTLY BELOW CLIMO. ANOTHER LARGE BUT WEAK AREA OF HIGH PRESSURE BUILDS DOWN FROM THE NW LATE SUNDAY AND PERSISTS INTO TUESDAY WHILE SLOWLY DRIFTING ACROSS THE REGION. THIS CONTINUES THE COOL AND DRY WEATHER WITH NEAR TO SLIGHTLY-BELOW SEASONABLE TEMPS. THIS HIGH PRESSURE THEN DRIFTS OFFSHORE TUESDAY AHEAD OF ANOTHER COLD FRONT PROGGED TO CROSS THE AREA LATE IN THE DAY. GUIDANCE SHOWING CONSIDERABLE AMPLITUDE DIFFERENCES IN THE TROUGH DRIVING THIS FRONT WHICH WILL HAVE SIGNIFICANT IMPACT ON PRECIP POTENTIAL. FOR NOW WILL KEEP INHERITED SCHC/SILENT POP FOR D6 SINCE BENEFICIAL CHANGES CANNOT BE MADE AT THIS TIME. TUESDAY WILL LIKELY BE THE WARMEST DAY OF THE PERIOD THOUGH AHEAD OF THE COLD FRONT...WITH TEMPS RETURNING TO BELOW CLIMO FOR WEDNESDAY AS ANOTHER AREA OF HIGH PRESSURE RIDGES DOWN FROM THE NW. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 18Z...VFR WITH CLEAR SKIES THIS AFTERNOON. A TIGHT PRESSURE GRADIENT WILL PRODUCE WSW-W WINDS 15-25 KNOTS WITH SPEEDS GRADUALLY DIMINISHING. VFR THIS EVENING AND OVERNIGHT WITH WSW WINDS 6-12 KNOTS. ANOTHER COLD FRONT WILL TRAVERSE THE TERMINALS AFTER SUNRISE. MAINLY SCATTERED VFR LEVEL LOW CLOUDS EXPECTED AS WINDS SHIFT TO THE WNW GUSTING TO AROUND 25 KNOTS. EXTENDED OUTLOOK...VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM THURSDAY...NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST. WINDS OUT AT FRYING PAN SHOALS BUOY ARE GUSTING TO 33 KNOTS ON THE LATEST OBSERVATION...AND GUSTS AT THE VARIOUS PIERS AND BEACH OBSERVATIONS FINALLY ARE BELOW 30 KNOTS. SEAS CONTINUE TO DIMINISH AS WELL. THE SMALL CRAFT ADVISORY WILL REMAIN POSTED FOR THE ONGOING WINDS...AND FOR THE ANTICIPATION OF A RENEWED SURGE OF NORTHWEST WINDS FRIDAY MORNING BEHIND A SECOND COLD FRONT. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS... EARLIER BLOWOUT TIDE CONDITIONS HAVE ABATED. WATER LEVELS AS MEASURED AT THE OFFICIAL NOS (NATIONAL OCEAN SERVICE) TIDE GAUGES REACHED -1.92 FT MLLW AT WRIGHTSVILLE BEACH... AND -1.50 FT MLLW AT MYRTLE BEACH. FOR THE NEXT LOW TIDE JUST AFTER 4 PM...WESTERLY WINDS SHOULD BE DIMINISHING WITH LESS IMPACT ON COASTAL WATER LEVELS. OTHERWISE...WEST WINDS AROUND 30 KNOTS WITH FREQUENT GALE-FORCE GUSTS ARE STILL OCCURRING ACROSS THE AREA THIS MORNING. I WISH THE GALE WARNING WERE STILL UP AS GUSTS AT THE FRYING PAN SHOALS BUOY CONTINUE TO ECLIPSE 40 KNOTS...AND WITH 12 FOOT SEAS I AM FAIRLY CERTAIN SUSTAINED GALE-FORCE WINDS ARE OCCURRING BEYOND 15 MILES FROM SHORE. THESE VERY STRONG WINDS SHOULD BEGIN TO ABATE OVER THE NEXT 2 HOURS AS HIGH PRESSURE OVER SOUTHERN LOUISIANA NOSES TOWARD THE CAROLINAS AND OUR PRESSURE GRADIENT BEGINS TO WEAKEN. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 AM THURSDAY...SMALL CRAFT ADVISORY CONTINUES INTO FRI BEFORE PASSAGE OF COLD FRONT AND DEVELOPMENT OF OFFSHORE FLOW PUSHES 6 FT SEAS BEYOND 20 NM. STRONG BUT BRIEF COLD ADVECTION DURING THE SECOND HALF OF FRI INTO FRI NIGHT MAY REQUIRE A PERIOD OF SCEC HEADLINES. HIGH PRESSURE BUILDS IN FROM THE WEST LATE FRI NIGHT THEN SHIFTS OVER THE WATERS DURING SAT. WEAKENING GRADIENT ALLOWS WIND SPEEDS TO DROP FROM A SOLID 20 KT FRI TO UNDER 10 KT BY SAT MORNING. RETURN FLOW STARTS TO DEVELOPING SAT AFTERNOON AS HIGH PRESSURE SLIDES EAST OF THE WATERS. GRADIENT BECOMES PINCHED AHEAD OF NEXT COLD FRONT...WITH SOUTHWEST WINDS INCREASING TO 15 KT AS THE PERIOD ENDS. SEAS SUBSIDE DURING FRI...DROPPING FROM 4 TO 7 FT AT THE START OF THE PERIOD TO 3 TO 4 FT FRI EVENING. SEAS FALL FURTHER...CLOSE TO 2 FT...EARLY SAT BEFORE STARTING TO BUILD BACK CLOSER TO 3 TO 4 FT LATE IN THE PERIOD AS SOUTHWEST WINDS INCREASE. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 3 AM THURSDAY...A COLD FRONT WILL CROSS THE WATERS SUNDAY... TURNING WINDS TO THE W/NW AT 10-15 KTS ON SUNDAY BEFORE SLOWLY EASING TO LIGHT AND VARIABLE AGAIN MONDAY AS HIGH PRESSURE BUILDS BACK OVER THE WATERS. SEAS WILL BE PRIMARILY WIND-DRIVEN THROUGH THE PERIOD...INCREASING FOR A SHORT TIME SUNDAY UP TO 2-4 FT... THEN DECREASING TO 1 TO 2 FT MONDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...JDW AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
937 AM EST THU JAN 31 2013 .SYNOPSIS... COOL HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...WITH BELOW NORMAL TEMPERATURES EXPECTED. IT WILL BE BREEZY TODAY... ALTHOUGH WINDS WILL NOT BE AS STRONG AS LAST NIGHT. A SERIES OF DRY COLD FRONTS WILL MOVE ACROSS THE AREA. THE FIRST FRONT WILL CROSS THE AREA FRIDAY FOLLOWED BY ANOTHER ON SUNDAY AND YET ANOTHER ON TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM THURSDAY...THE SEASONS HAVE CHANGED YET AGAIN WITH YESTERDAY`S SPRING-LIKE WEATHER REPLACED BY A RETURN TO WINTER TODAY. COLD ADVECTION ON WESTERLY WINDS BEHIND LAST NIGHT`S STRONG COLD FRONT WILL ALMOST PERFECTLY BALANCE NEARLY FULL SUNSHINE TODAY AND TEMPERATURES WILL STRUGGLE JUST TO RISE A FEW DEGREES BY AFTERNOON...REACHING 53-56 DEGREES AREAWIDE. THE 12Z GSO SOUNDING WAS BEST SIMULATED BY THE 12Z NAM AND RUC MODELS...AND THESE ARE THE TWO MODELS I BLENDED FOR MY UPDATED FORECAST TODAY. DOWNWARD REVISIONS HAVE BEEN MADE TO DEWPOINT FORECASTS FOR THE AFTERNOON HOURS WITH LOWER 20S DEWPOINTS EXPECTED TO MIX DOWN FROM A RESERVOIR OF VERY DRY AIR ALOFT. PRECIPITABLE WATER VALUES TODAY SHOULD RANGE FROM 0.20 TO 0.25 INCHES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 AM THURSDAY...SHORTWAVE ROUNDING BASE OF MID LEVEL TROUGH EARLY FRI HELPS DRIVE A REINFORCING SHOT OF COLD AIR INTO THE REGION. DRY COLD FRONT PUSHES OFFSHORE BY MIDDAY WITH A PERIOD OF BRIEF BUT STRONG COLD ADVECTION ENDING LATE FRI NIGHT. TEMP DROP WILL BE SIGNIFICANT WITH GUIDANCE SHOWING 850 TEMPS DECREASING BY AS MUCH AS 10C IN SOME PLACES IN UNDER 12 HOURS. DEEP WEST TO NORTHWEST FLOW FRI INTO FRI NIGHT HELPS KEEP SKIES CLEAR. PATTERN BECOMES LESS AMPLIFIED AND MORE PROGRESSIVE LATE FRI NIGHT...SHUTTING OFF COLD ADVECTION. MORE PROGRESSIVE EVOLUTION OF MID LEVEL PATTERN HELPS MOVE CENTER OF SURFACE RIDGE AXIS OVER THE REGION FOR SAT MORNING...ALLOWING FOR SOME RADIATIONAL COOLING. DO NOT ANTICIPATE EFFECT TO BE VERY STRONG BUT TYPICAL COLD SPOTS WILL FLIRT WITH TEENS FOR LOWS. HIGHS FRI WILL STRUGGLE TO REACH CLIMO WHILE LOWS WILL DROP INTO THE LOW TO MID 20S IN MOST AREAS SAT MORNING. SURFACE RIDGE AXIS SHIFTS OFFSHORE SAT WITH WEAK RETURN FLOW SETTING UP FOR THE END OF THE PERIOD. ALOFT ANOTHER SHORTWAVE HELPS AMPLIFY THE MID LEVEL PATTERN...RESULTING IN A SHORT PERIOD OF DEEP WEST-SOUTHWEST FLOW AHEAD OF ANOTHER COLD FRONT MOVING INTO THE REGION AS THE PERIOD ENDS. ANTICIPATE AN INCREASE IN MID AND UPPER LEVEL CLOUD ASSOCIATED WITH THIS WAVE BUT DURATION OF RETURN FLOW IS NOT ENOUGH TO BRING SIGNIFICANT MOISTURE BACK INTO THE REGION BEFORE THE FRONT PASSES. ALTHOUGH SOME GUIDANCE IS POINTING TO SOME LIGHT ISOLATED PRECIP EARLY SUN MORNING DO NOT THINK THIS WILL BE THE CASE. WILL MAINTAIN A POP FORECAST AROUND 10 SAT NIGHT. TEMPERATURES REMAIN BELOW CLIMO SAT BUT END UP MUCH CLOSER TO CLIMO SAT NIGHT. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 3 AM THURSDAY...A RATHER REPETITIVE PATTERN FOR THE EXTENDED AS AREAS OF HIGH PRESSURE PUSH OFFSHORE AHEAD OF A SERIES OF WEAK COLD FRONTS. FIRST COLD FRONT WILL CROSS THE AREA VERY EARLY SUNDAY MORNING. LIMITED FORCING COMBINED WITH ONLY MARGINAL PWATS SUGGESTS FROPA WILL BE DRY...AND ONLY ACT TO REINFORCE THE COOL AIR. HOWEVER...ANY WEAK CAA REMAINS WELL DISPLACED BEHIND THE FRONT...SO SUNDAY WILL END UP BEING WARMER THAN SATURDAY...ALTHOUGH BOTH DAYS WILL BE AROUND TO SLIGHTLY BELOW CLIMO. ANOTHER LARGE BUT WEAK AREA OF HIGH PRESSURE BUILDS DOWN FROM THE NW LATE SUNDAY AND PERSISTS INTO TUESDAY WHILE SLOWLY DRIFTING ACROSS THE REGION. THIS CONTINUES THE COOL AND DRY WEATHER WITH NEAR TO SLIGHTLY-BELOW SEASONABLE TEMPS. THIS HIGH PRESSURE THEN DRIFTS OFFSHORE TUESDAY AHEAD OF ANOTHER COLD FRONT PROGGED TO CROSS THE AREA LATE IN THE DAY. GUIDANCE SHOWING CONSIDERABLE AMPLITUDE DIFFERENCES IN THE TROUGH DRIVING THIS FRONT WHICH WILL HAVE SIGNIFICANT IMPACT ON PRECIP POTENTIAL. FOR NOW WILL KEEP INHERITED SCHC/SILENT POP FOR D6 SINCE BENEFICIAL CHANGES CANNOT BE MADE AT THIS TIME. TUESDAY WILL LIKELY BE THE WARMEST DAY OF THE PERIOD THOUGH AHEAD OF THE COLD FRONT...WITH TEMPS RETURNING TO BELOW CLIMO FOR WEDNESDAY AS ANOTHER AREA OF HIGH PRESSURE RIDGES DOWN FROM THE NW. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 12Z...SCATTERED TO BROKEN MVFR LEVEL CLOUDS TRAVERSING MAINLY THE KILM TERMINAL WILL SHIFT QUICKLY OFFSHORE 13-14Z. SCATTERED TO BROKEN VFR LEVEL LOW CLOUDS WILL LIKELY PERSIST AT LEAST THROUGH THE EARLY MORNING HOURS FROM KLBT/KILM NORTH. SIGNIFICANT DRYING OF THE AIRMASS SHOULD LEAD TO GENERALLY CLEAR SKIES AT ALL TERMINALS BY LATE MORNING. A TIGHT PRESSURE GRADIENT WILL PRODUCE WSW-W WINDS 15-25 KNOTS WITH ISOLATED GUSTS 30-35 KNOTS EARLY THIS MORNING. WIND SPEEDS WILL GRADUALLY EASE THROUGH THE DAY. WILL NOT INCLUDE WIND SHEAR IN TAFS THIS MORNING AS KLTX WIND PROFILE DATA AND SURFACE REPORTS SUGGESTS WIND SPEEDS ARE GRADUALLY INCREASING SFC-2K. VFR THIS EVENING AND OVERNIGHT WITH WSW WINDS 6-12 KNOTS. EXTENDED OUTLOOK...VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM THURSDAY...EARLIER BLOWOUT TIDE CONDITIONS HAVE ABATED. WATER LEVELS AS MEASURED AT THE OFFICIAL NOS (NATIONAL OCEAN SERVICE) TIDE GAUGES REACHED -1.92 FT MLLW AT WRIGHTSVILLE BEACH... AND -1.50 FT MLLW AT MYRTLE BEACH. FOR THE NEXT LOW TIDE JUST AFTER 4 PM...WESTERLY WINDS SHOULD BE DIMINISHING WITH LESS IMPACT ON COASTAL WATER LEVELS. OTHERWISE...WEST WINDS AROUND 30 KNOTS WITH FREQUENT GALE-FORCE GUSTS ARE STILL OCCURRING ACROSS THE AREA THIS MORNING. I WISH THE GALE WARNING WERE STILL UP AS GUSTS AT THE FRYING PAN SHOALS BUOY CONTINUE TO ECLIPSE 40 KNOTS...AND WITH 12 FOOT SEAS I AM FAIRLY CERTAIN SUSTAINED GALE-FORCE WINDS ARE OCCURRING BEYOND 15 MILES FROM SHORE. THESE VERY STRONG WINDS SHOULD BEGIN TO ABATE OVER THE NEXT 2 HOURS AS HIGH PRESSURE OVER SOUTHERN LOUISIANA NOSES TOWARD THE CAROLINAS AND OUR PRESSURE GRADIENT BEGINS TO WEAKEN. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 AM THURSDAY...SMALL CRAFT ADVISORY CONTINUES INTO FRI BEFORE PASSAGE OF COLD FRONT AND DEVELOPMENT OF OFFSHORE FLOW PUSHES 6 FT SEAS BEYOND 20 NM. STRONG BUT BRIEF COLD ADVECTION DURING THE SECOND HALF OF FRI INTO FRI NIGHT MAY REQUIRE A PERIOD OF SCEC HEADLINES. HIGH PRESSURE BUILDS IN FROM THE WEST LATE FRI NIGHT THEN SHIFTS OVER THE WATERS DURING SAT. WEAKENING GRADIENT ALLOWS WIND SPEEDS TO DROP FROM A SOLID 20 KT FRI TO UNDER 10 KT BY SAT MORNING. RETURN FLOW STARTS TO DEVELOPING SAT AFTERNOON AS HIGH PRESSURE SLIDES EAST OF THE WATERS. GRADIENT BECOMES PINCHED AHEAD OF NEXT COLD FRONT...WITH SOUTHWEST WINDS INCREASING TO 15 KT AS THE PERIOD ENDS. SEAS SUBSIDE DURING FRI...DROPPING FROM 4 TO 7 FT AT THE START OF THE PERIOD TO 3 TO 4 FT FRI EVENING. SEAS FALL FURTHER...CLOSE TO 2 FT...EARLY SAT BEFORE STARTING TO BUILD BACK CLOSER TO 3 TO 4 FT LATE IN THE PERIOD AS SOUTHWEST WINDS INCREASE. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 3 AM THURSDAY...A COLD FRONT WILL CROSS THE WATERS SUNDAY... TURNING WINDS TO THE W/NW AT 10-15 KTS ON SUNDAY BEFORE SLOWLY EASING TO LIGHT AND VARIABLE AGAIN MONDAY AS HIGH PRESSURE BUILDS BACK OVER THE WATERS. SEAS WILL BE PRIMARILY WIND-DRIVEN THROUGH THE PERIOD...INCREASING FOR A SHORT TIME SUNDAY UP TO 2-4 FT... THEN DECREASING TO 1 TO 2 FT MONDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...JDW AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EST THU JAN 31 2013 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE STATE EARLY THIS MORNING.... FOLLOWED BY COLDER AND DRIER AIR TODAY. A WEAK AND MOSTLY DRY COLD FRONT SYSTEM WILL CROSS THE AREA EARLY FRIDAY WITH HIGH PRESSURE BUILDING BACK IN FOR THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM THURSDAY... SQUALL LINE HAS PUSHES EAST OF THE CWA AND TO TORNADO WATCH WAS ALLOWED TO EXPIRE AT 2AM. WINDS IMMEDIATELY BEHIND THE LINE CONTINUE TO GUST TO 30-35KT...BUT DIE OFF WITH WESTWARD EXTENT AWAY FROM THE LINE. THE IS AN AREA OF STRONGER GUSTS OVER NORTHERN GA AND WESTERN SC...BUT HRRR WIND GUST FIELDS SUGGEST THESE WINDS WILL SHIFT EAST ACROSS SC. THUS...WE WILL ALLOW THE WIND ADVISORY TO EXPIRE AT 4AM. THE COLD FRONT...CURRENTLY EMERGING EAST OF THE MOUNTAINS..WILL PUSH EAST ACROSS THE CWA THIS MORNING AND IN TO THE COASTAL PLAIN BY 12Z. EXPECT WINDS WILL GUST PERIODICALLY TO AROUND 20KT WITH THE FRONT...THEN BECOME MORE CONSISTENT IN THE 20-25KT RANGE OUT OF THE WEST BEHIND THE FRONT TODAY. A FEW SHOWERS ARE POSSIBLE ALONG THE FRONT...MAINLY NORTH...AND DRYING ALOFT SHOULD LIMIT COVERAGE IN THE SOUTH. DESPITE CLEARING BEHIND THE FRONT...MODEST COLD ADVECTION WILL DOMINATE THE FIRST HALF OF THE DAY... KEEPING TEMPS FROM RISING MORE THAN 4-6 DEGREES ON MOST PLACES...RANGING FROM THE MID 40S NORTHWEST TO LOWER 50S SOUTHEAST. ANOTHER SHORTWAVE TROUGH DIGGING SOUTHEAST OUT OF CANADA WILL SWING ACROSS THE MID ATLANTIC STATES LATE TONIGHT. STRENGTHENING DPVA AND A BRIEF SHOT OF 60-80M HEIGHT FALLS FOCUSED ALONG THE NC/VA BORDER AND NORTHWARD...COMBINED WITH A BAND OF MID LEVEL MOISTURE CROSSING THE MOUNTAINS MAY BE SUFFICIENT TO CAUSE FLURRIES...MAINLY IN THE 09-12Z TIME FRAME. THE GFS HAS THE MOST ABUNDANT MOISTURE IN GENERAL...WITH MOISTURE REACHING TO -10C IN A BAND THAT SPANS THE ENTIRE CWA. HOWEVER...MOISTURE WITHIN THE ICE NUCLEATION ZONE IS ONLY PRESENT NORTH OF I-40 AND MOST PRONOUNCED NEAR THE NC/VA BORDER. THE LIMITED DURATION OF LIFT AND MOISTURE..AS WELL AS A RELATIVELY DRY BOUNDARY LAYER AND POTENTIAL FOR SUBLIMATION...WILL KEEP THIS TO A NO IMPACT EVENT. LOWS IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 250 AM WEDNESDAY... FOR FRIDAY/FRIDAY NIGHT: THE RISK OF A QUICK FLURRY OR SPRINKLE IS LIKELY TO STRETCH PAST SUNRISE FRIDAY AS THE MID LEVEL SHORTWAVE TROUGH SHIFTS EASTWARD OFF THE MIDATLANTIC COAST AND THE REINFORCING CLIPPER COLD FRONT MOVES EAST OF CENTRAL NC. THE LOWEST 10 KFT LAYER DRIES OUT RAPIDLY BY MID MORNING WITH WINDS IN THIS LAYER VEERING TO NORTHWESTERLY AND STRONG DEEP SUBSIDENCE COMMENCING AS THE 160 KT UPPER JET CORE SHIFTS FURTHER EAST OFF THE VA/NC COAST. EXPECT GENERALLY CLEAR SKIES FROM LATE MORNING THROUGH THE DAY WITH A DRY AND HIGHLY STABLE COLUMN. THE LOW LEVEL THERMAL STRUCTURE MIXING UP TO ABOUT 800 MB SUPPORTS CHILLY HIGHS FROM 36 NORTH TO 46 NEAR THE SC BORDER. TEMPS SHOULD DROP OFF QUICKLY AFTER SUNSET FRIDAY EVENING THEN LEVEL OFF AS WE BEGIN TO SEE INCREASING HIGH AND MID CLOUDS OVERNIGHT... AS MID LEVEL DPVA AND HEIGHT FALLS ARRIVE AHEAD OF THE NEXT CLIPPER. BUT THESE CLOUDS SHOULD BE FAIRLY THIN AND GIVEN THE VERY COLD YUKON ORIGINS OF THIS INCOMING AIR MASS AND THE WINDS GOING NEARLY CALM AS THE SURFACE RIDGE AXIS SETTLES OVERHEAD... STILL ANTICIPATE ABNORMALLY COLD LOWS OF 18-24. FOR SATURDAY/SATURDAY NIGHT: THE NEXT CLIPPER FRONT WILL STRETCH FROM THE GREAT LAKES ACROSS MO SATURDAY MORNING... WITH AN ASSOCIATED WEAK WARM FRONT EXTENDING FROM IL TO SC. THE WARM FRONT WILL SWEEP NORTHEASTWARD THROUGH THE NC SATURDAY AFTERNOON AS THE SURFACE RIDGE PUSHES OFF THE COAST. CLOUD COVER WILL CONTINUE TO THICKEN AND LOWER WITH INCREASING MID LEVEL HEIGHT FALLS IN ADVANCE OF THE MID LEVEL SHORTWAVE TROUGH APPROACHING NC. DESPITE THE CLOUDS... THE ENSUING SOUTHWEST LOW LEVEL FLOW SHOULD ALLOW THICKNESSES AND TEMPS TO REBOUND TO JUST SLIGHTLY BELOW NORMAL... HIGHS OF 45-50. MODELS DEPICT A 35-40 KT LOW LEVEL SOUTHWESTERLY JET MOVING THROUGH THE REGION LATE SATURDAY AFTERNOON INTO THE EVENING... COINCIDENT WITH FORECAST SOUNDINGS SHOWING DEEPENING MOISTURE FROM 850 MB UP BEYOND 500 MB... AND AHEAD OF A MID LEVEL VORTICITY MAX AND SHORTWAVE TROUGH THAT WILL BE TAKING ON A NEGATIVE TILT AS IT PASSES THROUGH NC. THE SUBCLOUD LAYER SHOULD REMAIN FAIRLY DRY HOWEVER... SO MUCH OF WHAT FALLS IS LIKELY TO EVAPORATE/SUBLIMATE. GIVEN THAT THE WEB BULB PROFILE ON FORECAST SOUNDINGS SHOULD BE CLOSE TO FREEZING AT THE SURFACE DURING THIS TIME IN THE NORTHERN FORECAST AREA AND LIKELY JUST ABOVE FREEZING IN THE SOUTH... A COMBINATION OF LIGHT SPRINKLES OR FLURRIES STILL APPEARS REASONABLE. INTERESTING TO NOTE ARE THE GFS`S LAPSE RATES ALOFT WHICH REACH 7.0 C/KM 800-500 MB SATURDAY NIGHT... SUGGESTING THAT IF DYNAMIC FORCING FOR ASCENT IS STRONG ENOUGH TO AUGMENT INSTABILITY ALOFT... WE MAY SEE A LIGHTNING STRIKE OR TWO IF THE GFS`S STRONGER VORTICITY MAX IS CORRECT. AT ANY RATE... WILL LEAVE IN A LOW CHANCE POP AREAWIDE FOR LATE AFTERNOON WELL INTO THE NIGHT... BUT AGAIN EXPECT LITTLE MORE THAN TRACE TO A COUPLE OF HUNDREDTHS OF AN INCH OF LIQUID EQUIVALENT AS THE SURFACE AIR REMAINS DRY. SKIES SHOULD CLEAR OUT LATE SATURDAY NIGHT WITH NVA IN THE WAKE OF THE EXITING TROUGH. LOWS 30-35. -GIH && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 315 AM WEDNESDAY... FOR SUNDAY: ONE LAST SHOT OF POLAR STREAM ENERGY DIVES DOWN THE SW SIDE OF THE MEAN TROUGH... FROM THE GREAT LAKES THROUGH WV AND ACROSS DELMARVA WITH A SURFACE CLIPPER COLD FRONT NOT FAR BEHIND. IT APPEARS THAT THE MID LEVELS WILL HAVE DRIED OUT AND STABILIZED BY THIS TIME... AND MOISTURE IS UNIMPRESSIVE IN THE SURFACE-BASED MIXED LAYER AS WELL... SO WILL SHOWS SOME CLOUDS SWEEPING THROUGH THE AREA BUT WITH NO PRECIP CHANCES. THICKNESSES REMAIN SEASONABLE SO EXPECT HIGHS OF 49-55. FOR SUNDAY NIGHT THROUGH WEDNESDAY: THE COLD LONGWAVE TROUGH OVER EASTERN NOAM FINALLY RETREATS NORTHWARD AND WEAKENS WITH RISING HEIGHTS AND A FLATTENING FLOW OVER OUR REGION LASTING THROUGH MID WEEK... AS MODIFYING SURFACE HIGH PRESSURE BUILDS IN. THE HIGH IS INITIALLY CHILLY AND TEMPS MONDAY SHOULD RUN SEVERAL DEGREES BELOW NORMAL... PARTICULARLY WITH MILKY SUNSHINE TO LIMIT INSOLATION AS ONE LAST MINOR WAVE AND MID LEVEL SPEED MAX MOVE IN FROM THE WEST. TEMPS SHOULD THEN RECOVER TO ABOVE NORMAL TUESDAY INTO WEDNESDAY AS THE SURFACE HIGH QUICKLY MODIFIES AS IT EASES TO OUR SOUTH. THE GFS/ECMWF BOTH SHOWS THIS HIGH PUSHING SOUTHWARD AND WEAKENING AS A BACKDOOR FRONT APPROACHES FROM THE NORTH... ALTHOUGH THE ECMWF SWINGS A POTENT NORTHERN STREAM WAVE THROUGH THE MIDATLANTIC REGION... AND AS A RESULT HAS A MUCH STRONGER AND FASTER BACKDOOR FRONT AND A NOTABLE COOLDOWN BY WEDNESDAY. WILL STAY WITH THE LESS AMPLIFIED ROUTE OF THE GFS AT THIS TIME... AND KEEP TEMPS MILD ON WEDNESDAY WITH FAIR SKIES. -GIH && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 650 AM THURSDAY... COLD CURRENTLY PUSHING EAST THROUGH THE AREA WILL FORCE THE REMAINING SHOWERS AND 3-4K FT CEILINGS BETWEEN KRWI AND KFAY TO MOVE EAST OF THE AREA. THE STRONGEST WESTERLY WINDS ARE CURRENTLY OVER THE SOUTHERN PORTIONS OF THE AREA...WHERE 25-30KT GUSTS ARE STILL BEING REPORTED. THESE WINDS WILL WEAKEN THIS MORNING ONCE THE FRONT MOVES THROUGH THE AREA. HOWEVER...THE APPROACH OF ANOTHER DISTURBANCE FROM THE NORTHWEST AND STRENGTHENING LOW LEVEL WINDS WILL LEAD TO 15-20KT SUSTAINED WESTERLY WINDS WITH GUSTS APPROACHING 30KT POSSIBLE LATER THIS AFTERNOON. WHILE VFR CEILINGS AND VSBYS WILL PREVAIL...A CROSSWIND MAY CAUSE SOME ADVERSE AVIATION CONDITIONS FOR SMALLER AIRCRAFT. LOSS OF HEATING SHOULD ALLOW WINDS TO WEAKEN AFTER 00Z..THOUGH SPORADIC GUSTS TO AROUND 20KT MAY CONTINUE INTO THE OVERNIGHT HOURS. MID CLOUDS WILL INCREASE LATE TONIGHT AS THE AFOREMENTIONED DISTURBANCE NEARS THE AREA. OUTLOOK...VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL THROUGH EARLY NEXT WEEK. A DISTURBANCE FORECAST TO CROSS THE AREA SATURDAY/SATURDAY NIGHT WILL BRING ADDED CLOUD COVER AND THE POTENTIAL FOR A SHORT PERIOD OF RAIN OR SNOW. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE && $$ SYNOPSIS...SMITH NEAR TERM...SMITH SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 AM EST THU JAN 31 2013 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE STATE EARLY THIS MORNING.... FOLLOWED BY COLDER AND DRIER AIR TODAY. A WEAK AND MOSTLY DRY COLD FRONT SYSTEM WILL CROSS THE AREA EARLY FRIDAY WITH HIGH PRESSURE BUILDING BACK IN FOR THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 255 AM THURSDAY... A WIND ADVISORY REMAINS IN EFFECT ACROSS ALL OF CENTRAL NC THROUGH 4 AM LST. SQUALL LINE HAS PUSHES EAST OF THE CWA AND TO TORNADO WATCH WAS ALLOWED TO EXPIRE AT 2AM. WINDS IMMEDIATELY BEHIND THE LINE CONTINUE TO GUST TO 30-35KT...BUT DIE OFF WITH WESTWARD EXTENT AWAY FROM THE LINE. THE IS AN AREA OF STRONGER GUSTS OVER NORTHERN GA AND WESTERN SC...BUT HRRR WIND GUST FIELDS SUGGEST THESE WINDS WILL SHIFT EAST ACROSS SC. THUS...WE WILL ALLOW THE WIND ADVISORY TO EXPIRE AT 4AM. THE COLD FRONT...CURRENTLY EMERGING EAST OF THE MOUNTAINS..WILL PUSH EAST ACROSS THE CWA THIS MORNING AND IN TO THE COASTAL PLAIN BY 12Z. EXPECT WINDS WILL GUST PERIODICALLY TO AROUND 20KT WITH THE FRONT...THEN BECOME MORE CONSISTENT IN THE 20-25KT RANGE OUT OF THE WEST BEHIND THE FRONT TODAY. A FEW SHOWERS ARE POSSIBLE ALONG THE FRONT...MAINLY NORTH...AND DRYING ALOFT SHOULD LIMIT COVERAGE IN THE SOUTH. DESPITE CLEARING BEHIND THE FRONT...MODEST COLD ADVECTION WILL DOMINATE THE FIRST HALF OF THE DAY... KEEPING TEMPS FROM RISING MORE THAN 4-6 DEGREES ON MOST PLACES...RANGING FROM THE MID 40S NORTHWEST TO LOWER 50S SOUTHEAST. ANOTHER SHORTWAVE TROUGH DIGGING SOUTHEAST OUT OF CANADA WILL SWING ACROSS THE MID ATLANTIC STATES LATE TONIGHT. STRENGTHENING DPVA AND A BRIEF SHOT OF 60-80M HEIGHT FALLS FOCUSED ALONG THE NC/VA BORDER AND NORTHWARD...COMBINED WITH A BAND OF MID LEVEL MOISTURE CROSSING THE MOUNTAINS MAY BE SUFFICIENT TO CAUSE FLURRIES...MAINLY IN THE 09-12Z TIME FRAME. THE GFS HAS THE MOST ABUNDANT MOISTURE IN GENERAL...WITH MOISTURE REACHING TO -10C IN A BAND THAT SPANS THE ENTIRE CWA. HOWEVER...MOISTURE WITHIN THE ICE NUCLEATION ZONE IS ONLY PRESENT NORTH OF I-40 AND MOST PRONOUNCED NEAR THE NC/VA BORDER. THE LIMITED DURATION OF LIFT AND MOISTURE..AS WELL AS A RELATIVELY DRY BOUNDARY LAYER AND POTENTIAL FOR SUBLIMATION...WILL KEEP THIS TO A NO IMPACT EVENT. LOWS IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 250 AM WEDNESDAY... FOR FRIDAY/FRIDAY NIGHT: THE RISK OF A QUICK FLURRY OR SPRINKLE IS LIKELY TO STRETCH PAST SUNRISE FRIDAY AS THE MID LEVEL SHORTWAVE TROUGH SHIFTS EASTWARD OFF THE MIDATLANTIC COAST AND THE REINFORCING CLIPPER COLD FRONT MOVES EAST OF CENTRAL NC. THE LOWEST 10 KFT LAYER DRIES OUT RAPIDLY BY MID MORNING WITH WINDS IN THIS LAYER VEERING TO NORTHWESTERLY AND STRONG DEEP SUBSIDENCE COMMENCING AS THE 160 KT UPPER JET CORE SHIFTS FURTHER EAST OFF THE VA/NC COAST. EXPECT GENERALLY CLEAR SKIES FROM LATE MORNING THROUGH THE DAY WITH A DRY AND HIGHLY STABLE COLUMN. THE LOW LEVEL THERMAL STRUCTURE MIXING UP TO ABOUT 800 MB SUPPORTS CHILLY HIGHS FROM 36 NORTH TO 46 NEAR THE SC BORDER. TEMPS SHOULD DROP OFF QUICKLY AFTER SUNSET FRIDAY EVENING THEN LEVEL OFF AS WE BEGIN TO SEE INCREASING HIGH AND MID CLOUDS OVERNIGHT... AS MID LEVEL DPVA AND HEIGHT FALLS ARRIVE AHEAD OF THE NEXT CLIPPER. BUT THESE CLOUDS SHOULD BE FAIRLY THIN AND GIVEN THE VERY COLD YUKON ORIGINS OF THIS INCOMING AIR MASS AND THE WINDS GOING NEARLY CALM AS THE SURFACE RIDGE AXIS SETTLES OVERHEAD... STILL ANTICIPATE ABNORMALLY COLD LOWS OF 18-24. FOR SATURDAY/SATURDAY NIGHT: THE NEXT CLIPPER FRONT WILL STRETCH FROM THE GREAT LAKES ACROSS MO SATURDAY MORNING... WITH AN ASSOCIATED WEAK WARM FRONT EXTENDING FROM IL TO SC. THE WARM FRONT WILL SWEEP NORTHEASTWARD THROUGH THE NC SATURDAY AFTERNOON AS THE SURFACE RIDGE PUSHES OFF THE COAST. CLOUD COVER WILL CONTINUE TO THICKEN AND LOWER WITH INCREASING MID LEVEL HEIGHT FALLS IN ADVANCE OF THE MID LEVEL SHORTWAVE TROUGH APPROACHING NC. DESPITE THE CLOUDS... THE ENSUING SOUTHWEST LOW LEVEL FLOW SHOULD ALLOW THICKNESSES AND TEMPS TO REBOUND TO JUST SLIGHTLY BELOW NORMAL... HIGHS OF 45-50. MODELS DEPICT A 35-40 KT LOW LEVEL SOUTHWESTERLY JET MOVING THROUGH THE REGION LATE SATURDAY AFTERNOON INTO THE EVENING... COINCIDENT WITH FORECAST SOUNDINGS SHOWING DEEPENING MOISTURE FROM 850 MB UP BEYOND 500 MB... AND AHEAD OF A MID LEVEL VORTICITY MAX AND SHORTWAVE TROUGH THAT WILL BE TAKING ON A NEGATIVE TILT AS IT PASSES THROUGH NC. THE SUBCLOUD LAYER SHOULD REMAIN FAIRLY DRY HOWEVER... SO MUCH OF WHAT FALLS IS LIKELY TO EVAPORATE/SUBLIMATE. GIVEN THAT THE WEB BULB PROFILE ON FORECAST SOUNDINGS SHOULD BE CLOSE TO FREEZING AT THE SURFACE DURING THIS TIME IN THE NORTHERN FORECAST AREA AND LIKELY JUST ABOVE FREEZING IN THE SOUTH... A COMBINATION OF LIGHT SPRINKLES OR FLURRIES STILL APPEARS REASONABLE. INTERESTING TO NOTE ARE THE GFS`S LAPSE RATES ALOFT WHICH REACH 7.0 C/KM 800-500 MB SATURDAY NIGHT... SUGGESTING THAT IF DYNAMIC FORCING FOR ASCENT IS STRONG ENOUGH TO AUGMENT INSTABILITY ALOFT... WE MAY SEE A LIGHTNING STRIKE OR TWO IF THE GFS`S STRONGER VORTICITY MAX IS CORRECT. AT ANY RATE... WILL LEAVE IN A LOW CHANCE POP AREAWIDE FOR LATE AFTERNOON WELL INTO THE NIGHT... BUT AGAIN EXPECT LITTLE MORE THAN TRACE TO A COUPLE OF HUNDREDTHS OF AN INCH OF LIQUID EQUIVALENT AS THE SURFACE AIR REMAINS DRY. SKIES SHOULD CLEAR OUT LATE SATURDAY NIGHT WITH NVA IN THE WAKE OF THE EXITING TROUGH. LOWS 30-35. -GIH && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 315 AM WEDNESDAY... FOR SUNDAY: ONE LAST SHOT OF POLAR STREAM ENERGY DIVES DOWN THE SW SIDE OF THE MEAN TROUGH... FROM THE GREAT LAKES THROUGH WV AND ACROSS DELMARVA WITH A SURFACE CLIPPER COLD FRONT NOT FAR BEHIND. IT APPEARS THAT THE MID LEVELS WILL HAVE DRIED OUT AND STABILIZED BY THIS TIME... AND MOISTURE IS UNIMPRESSIVE IN THE SURFACE-BASED MIXED LAYER AS WELL... SO WILL SHOWS SOME CLOUDS SWEEPING THROUGH THE AREA BUT WITH NO PRECIP CHANCES. THICKNESSES REMAIN SEASONABLE SO EXPECT HIGHS OF 49-55. FOR SUNDAY NIGHT THROUGH WEDNESDAY: THE COLD LONGWAVE TROUGH OVER EASTERN NOAM FINALLY RETREATS NORTHWARD AND WEAKENS WITH RISING HEIGHTS AND A FLATTENING FLOW OVER OUR REGION LASTING THROUGH MID WEEK... AS MODIFYING SURFACE HIGH PRESSURE BUILDS IN. THE HIGH IS INITIALLY CHILLY AND TEMPS MONDAY SHOULD RUN SEVERAL DEGREES BELOW NORMAL... PARTICULARLY WITH MILKY SUNSHINE TO LIMIT INSOLATION AS ONE LAST MINOR WAVE AND MID LEVEL SPEED MAX MOVE IN FROM THE WEST. TEMPS SHOULD THEN RECOVER TO ABOVE NORMAL TUESDAY INTO WEDNESDAY AS THE SURFACE HIGH QUICKLY MODIFIES AS IT EASES TO OUR SOUTH. THE GFS/ECMWF BOTH SHOWS THIS HIGH PUSHING SOUTHWARD AND WEAKENING AS A BACKDOOR FRONT APPROACHES FROM THE NORTH... ALTHOUGH THE ECMWF SWINGS A POTENT NORTHERN STREAM WAVE THROUGH THE MIDATLANTIC REGION... AND AS A RESULT HAS A MUCH STRONGER AND FASTER BACKDOOR FRONT AND A NOTABLE COOLDOWN BY WEDNESDAY. WILL STAY WITH THE LESS AMPLIFIED ROUTE OF THE GFS AT THIS TIME... AND KEEP TEMPS MILD ON WEDNESDAY WITH FAIR SKIES. -GIH && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1250 AM THURSDAY... SQUALL LINE CURRENTLY EXTENDS FROM KAVC TO KJNX TO BETWEEN KFAY AND KCTZ...MOVING EAST AT AROUND 30 MPH. STRONGEST SOUTHERLY WINDS CONTINUE ALONG AND AHEAD OF THE LINE WHERE 35-40KT GUSTS ARE REPORTED. HEAVY RAIN AND A SHORT PERIOD OF IFR/LIFR VSBYS AND CEILINGS WILL OCCUR AT KRWI BETWEEN 06Z AND 07Z. BEHIND THE LINE...SOUTHWESTERLY WINDS WILL CONTINUE TO GUST TO 25-30KT IMMEDIATELY BEHIND THE LINE...WITH THE STRONGEST GUSTS LIKELY TO ACCOMPANY SCATTERED SHOWERS THROUGH 09Z. THE MAIN COLD FRONT IS CURRENTLY CROSSING THE MOUNTAINS AND WILL CROSS THE AREAS BY 12Z. WINDS WILL TURN TO MORE WESTERLY WITH THE FRONT AS CEILINGS AND VSBYS RETURN TO VFR. WHILE THERE MAY BE A WEAKENING TREND IN WINDS...EXPECT THERE WILL STILL BE SOME SPORADIC WIND GUSTS THROUGH THE MORNING HOURS...WITH WIDESPREAD WIND GUSTS TO 20-25KT OUT OF THE WEST DURING THE DAY. OUTLOOK...VFR CONDITIONS ARE THEN EXPECTED TO PREVAIL THROUGH EARLY NEXT WEEK. ALTHOUGH...A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE AREA...ONE FRIDAY MORNING AND ONE SATURDAY NIGHT AND COULD PRODUCE A PERIOD OF INCREASED CLOUDINESS...WITH EVEN A SMALL POSSIBILITY OF SOME SPRINKLES OR FLURRIES. && .RAH WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY THROUGH 4 AM EST THIS MORNING FOR NCZ007>011-021>028-038>043-073>078-083>086-088-089. && $$ SYNOPSIS...CBL/SMITH NEAR TERM...SMITH SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...KRR/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
308 AM EST THU JAN 31 2013 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE STATE EARLY THIS MORNING....FOLLOWED BY COLDER AND DRIER AIR TODAY. A WEAK AND MOSTLY DRY COLD FRONT SYSTEM WILL CROSS THE AREA EARLY FRIDAY WITH HIGH PRESSURE BUILDING BACK IN FOR THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 255 AM THURSDAY... ...A WIND ADVISORY ALSO REMAINS IN EFFECT ACROSS ALL OF CENTRAL NC THROUGH 4 AM LST... SQUALL LINE HAS PUSHES EAST OF THE CWA AND TO TORNADO WATCH WAS ALLOWED TO EXPIRE AT 2AM. WINDS IMMEDIATELY BEHIND THE LINE CONTINUE TO GUST TO 30-35KT...BUT DIE OFF WITH WESTWARD EXTENT AWAY FROM THE LINE. THE IS AN AREA OF STRONGER GUSTS OVER NORTHERN GA AND WESTERN SC...BUT HRRR WIND GUST FIELDS SUGGEST THESE WINDS WILL SHIFT EAST ACROSS SC. THUS...WE WILL ALLOW THE WIND ADVISORY TO EXPIRE AT 4AM. THE COLD FRONT...CURRENTLY EMERGING EAST OF THE MOUNTAINS..WILL PUSH EAST ACROSS THE CWA THIS MORNING AND IN TO THE COASTAL PLAIN BY 12Z. EXPECT WINDS WILL GUST PERIODICALLY TO AROUND 20KT WITH THE FRONT...THEN BECOME MORE CONSISTENT IN THE 20-25KT RANGE OUT OF THE WEST BEHIND THE FRONT TODAY. A FEW SHOWERS ARE POSSIBLE ALONG THE FRONT...MAINLY NORTH...AND DRYING ALOFT SHOULD LIMIT COVERAGE IN THE SOUTH. DESPITE CLEARING BEHIND THE FRONT...MODEST COLD ADVECTION WILL DOMINATE THE FIRST HALF OF THE DAY... KEEPING TEMPS FROM RISING MORE THAN 4-6 DEGREES ON MOST PLACES...RANGING FROM THE MID 40S NORTHWEST TO LOWER 50S SOUTHEAST. ANOTHER SHORTWAVE TROUGH DIGGING SOUTHEAST OUT OF CANADA WILL SWING ACROSS THE MID ATLANTIC STATES LATE TONIGHT. STRENGTHENING DPVA AND A BRIEF SHOT OF 60-80M HEIGHT FALLS FOCUSED ALONG THE NC/VA BORDER AND NORTHWARD...COMBINED WITH A BAND OF MID LEVEL MOISTURE CROSSING THE MOUNTAINS MAY BE SUFFICIENT TO CAUSE FLURRIES...MAINLY IN THE 09-12Z TIME FRAME. THE GFS HAS THE MOST ABUNDANT MOISTURE IN GENERAL...WITH MOISTURE REACHING TO -10C IN A BAND THAT SPANS THE ENTIRE CWA. HOWEVER...MOISTURE WITHIN THE ICE NUCLEATION ZONE IS ONLY PRESENT NORTH OF I-40 AND MOST PRONOUNCED NEAR THE NC/VA BORDER. THE LIMITED DURATION OF LIFT AND MOISTURE..AS WELL AS A RELATIVELY DRY BOUNDARY LAYER AND POTENTIAL FOR SUBLIMATION...WILL KEEP THIS TO A NO IMPACT EVENT. LOWS IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 250 AM WEDNESDAY... FOR FRIDAY/FRIDAY NIGHT: THE RISK OF A QUICK FLURRY OR SPRINKLE IS LIKELY TO STRETCH PAST SUNRISE FRIDAY AS THE MID LEVEL SHORTWAVE TROUGH SHIFTS EASTWARD OFF THE MIDATLANTIC COAST AND THE REINFORCING CLIPPER COLD FRONT MOVES EAST OF CENTRAL NC. THE LOWEST 10 KFT LAYER DRIES OUT RAPIDLY BY MID MORNING WITH WINDS IN THIS LAYER VEERING TO NORTHWESTERLY AND STRONG DEEP SUBSIDENCE COMMENCING AS THE 160 KT UPPER JET CORE SHIFTS FURTHER EAST OFF THE VA/NC COAST. EXPECT GENERALLY CLEAR SKIES FROM LATE MORNING THROUGH THE DAY WITH A DRY AND HIGHLY STABLE COLUMN. THE LOW LEVEL THERMAL STRUCTURE MIXING UP TO ABOUT 800 MB SUPPORTS CHILLY HIGHS FROM 36 NORTH TO 46 NEAR THE SC BORDER. TEMPS SHOULD DROP OFF QUICKLY AFTER SUNSET FRIDAY EVENING THEN LEVEL OFF AS WE BEGIN TO SEE INCREASING HIGH AND MID CLOUDS OVERNIGHT... AS MID LEVEL DPVA AND HEIGHT FALLS ARRIVE AHEAD OF THE NEXT CLIPPER. BUT THESE CLOUDS SHOULD BE FAIRLY THIN AND GIVEN THE VERY COLD YUKON ORIGINS OF THIS INCOMING AIR MASS AND THE WINDS GOING NEARLY CALM AS THE SURFACE RIDGE AXIS SETTLES OVERHEAD... STILL ANTICIPATE ABNORMALLY COLD LOWS OF 18-24. FOR SATURDAY/SATURDAY NIGHT: THE NEXT CLIPPER FRONT WILL STRETCH FROM THE GREAT LAKES ACROSS MO SATURDAY MORNING... WITH AN ASSOCIATED WEAK WARM FRONT EXTENDING FROM IL TO SC. THE WARM FRONT WILL SWEEP NORTHEASTWARD THROUGH THE NC SATURDAY AFTERNOON AS THE SURFACE RIDGE PUSHES OFF THE COAST. CLOUD COVER WILL CONTINUE TO THICKEN AND LOWER WITH INCREASING MID LEVEL HEIGHT FALLS IN ADVANCE OF THE MID LEVEL SHORTWAVE TROUGH APPROACHING NC. DESPITE THE CLOUDS... THE ENSUING SOUTHWEST LOW LEVEL FLOW SHOULD ALLOW THICKNESSES AND TEMPS TO REBOUND TO JUST SLIGHTLY BELOW NORMAL... HIGHS OF 45-50. MODELS DEPICT A 35-40 KT LOW LEVEL SOUTHWESTERLY JET MOVING THROUGH THE REGION LATE SATURDAY AFTERNOON INTO THE EVENING... COINCIDENT WITH FORECAST SOUNDINGS SHOWING DEEPENING MOISTURE FROM 850 MB UP BEYOND 500 MB... AND AHEAD OF A MID LEVEL VORTICITY MAX AND SHORTWAVE TROUGH THAT WILL BE TAKING ON A NEGATIVE TILT AS IT PASSES THROUGH NC. THE SUBCLOUD LAYER SHOULD REMAIN FAIRLY DRY HOWEVER... SO MUCH OF WHAT FALLS IS LIKELY TO EVAPORATE/SUBLIMATE. GIVEN THAT THE WEB BULB PROFILE ON FORECAST SOUNDINGS SHOULD BE CLOSE TO FREEZING AT THE SURFACE DURING THIS TIME IN THE NORTHERN FORECAST AREA AND LIKELY JUST ABOVE FREEZING IN THE SOUTH... A COMBINATION OF LIGHT SPRINKLES OR FLURRIES STILL APPEARS REASONABLE. INTERESTING TO NOTE ARE THE GFS`S LAPSE RATES ALOFT WHICH REACH 7.0 C/KM 800-500 MB SATURDAY NIGHT... SUGGESTING THAT IF DYNAMIC FORCING FOR ASCENT IS STRONG ENOUGH TO AUGMENT INSTABILITY ALOFT... WE MAY SEE A LIGHTNING STRIKE OR TWO IF THE GFS`S STRONGER VORTICITY MAX IS CORRECT. AT ANY RATE... WILL LEAVE IN A LOW CHANCE POP AREAWIDE FOR LATE AFTERNOON WELL INTO THE NIGHT... BUT AGAIN EXPECT LITTLE MORE THAN TRACE TO A COUPLE OF HUNDREDTHS OF AN INCH OF LIQUID EQUIVALENT AS THE SURFACE AIR REMAINS DRY. SKIES SHOULD CLEAR OUT LATE SATURDAY NIGHT WITH NVA IN THE WAKE OF THE EXITING TROUGH. LOWS 30-35. -GIH && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 150 PM WEDNESDAY... THE WARMER START AND INCREASING SUN EXPECTED ON SUNDAY WILL ALLOW HIGHS TO REBOUND FURTHER...INTO THE SEASONABLE LOWER 50S OVER MOST OF THE AREA. THE EAST COAST TROF AXIS SHIFTS OFFSHORE AND UPPER FLOW WILL NOT BE AS AMPLIFIED EARLY NEXT WEEK. ANOTHER REINFORCING BACKDOOR COLD FRONT WILL BE SLOWLY EDGING SOUTH AND POTENTIALLY STALLING ACROSS THE MID ATLANTIC ON TUESDAY INTO WEDNESDAY...BUT MOISTURE WILL BE LACKING AND FORCING WILL BE UNFOCUSED IN THE WEAKER UPPER FLOW. AT THIS POINT THE WEATHER MONDAY THROUGH WEDNESDAY LOOKS DRY AND SEASONABLY MILD WITH HIGHS MOSTLY IN THE LOW TO MID 50S EACH DAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1250 AM THURSDAY... SQUALL LINE CURRENTLY EXTENDS FROM KAVC TO KJNX TO BETWEEN KFAY AND KCTZ...MOVING EAST AT AROUND 30 MPH. STRONGEST SOUTHERLY WINDS CONTINUE ALONG AND AHEAD OF THE LINE WHERE 35-40KT GUSTS ARE REPORTED. HEAVY RAIN AND A SHORT PERIOD OF IFR/LIFR VSBYS AND CEILINGS WILL OCCUR AT KRWI BETWEEN 06Z AND 07Z. BEHIND THE LINE...SOUTHWESTERLY WINDS WILL CONTINUE TO GUST TO 25-30KT IMMEDIATELY BEHIND THE LINE...WITH THE STRONGEST GUSTS LIKELY TO ACCOMPANY SCATTERED SHOWERS THROUGH 09Z. THE MAIN COLD FRONT IS CURRENTLY CROSSING THE MOUNTAINS AND WILL CROSS THE AREAS BY 12Z. WINDS WILL TURN TO MORE WESTERLY WITH THE FRONT AS CEILINGS AND VSBYS RETURN TO VFR. WHILE THERE MAY BE A WEAKENING TREND IN WINDS...EXPECT THERE WILL STILL BE SOME SPORADIC WIND GUSTS THROUGH THE MORNING HOURS...WITH WIDESPREAD WIND GUSTS TO 20-25KT OUT OF THE WEST DURING THE DAY. OUTLOOK...VFR CONDITIONS ARE THEN EXPECTED TO PREVAIL THROUGH EARLY NEXT WEEK. ALTHOUGH...A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE AREA...ONE FRIDAY MORNING AND ONE SATURDAY NIGHT AND COULD PRODUCE A PERIOD OF INCREASED CLOUDINESS...WITH EVEN A SMALL POSSIBILITY OF SOME SPRINKLES OR FLURRIES. && .RAH WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY THROUGH 4 AM EST THIS MORNING FOR NCZ007>011-021>028-038>043-073>078-083>086-088-089. && $$ SYNOPSIS...CBL/SMITH NEAR TERM...SMITH SHORT TERM...HARTFIELD LONG TERM...MLM AVIATION...KRR/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EST THU JAN 31 2013 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE STATE EARLY THIS MORNING....FOLLOWED BY COLDER AND DRIER AIR TODAY. A WEAK AND MOSTLY DRY COLD FRONT SYSTEM WILL CROSS THE AREA EARLY FRIDAY WITH HIGH PRESSURE BUILDING BACK IN FOR THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 255 AM THURSDAY... ...A WIND ADVISORY ALSO REMAINS IN EFFECT ACROSS ALL OF CENTRAL NC THROUGH 4 AM LST... SQUALL LINE HAS PUSHES EAST OF THE CWA AND TO TORNADO WATCH WAS ALLOWED TO EXPIRE AT 2AM. WINDS IMMEDIATELY BEHIND THE LINE CONTINUE TO GUST TO 30-35KT...BUT DIE OFF WITH WESTWARD EXTENT AWAY FROM THE LINE. THE IS AN AREA OF STRONGER GUSTS OVER NORTHERN GA AND WESTERN SC...BUT HRRR WIND GUST FIELDS SUGGEST THESE WINDS WILL SHIFT EAST ACROSS SC. THUS...WE WILL ALLOW THE WIND ADVISORY TO EXPIRE AT 4AM. THE COLD FRONT...CURRENTLY EMERGING EAST OF THE MOUNTAINS..WILL PUSH EAST ACROSS THE CWA THIS MORNING AND IN TO THE COASTAL PLAIN BY 12Z. EXPECT WINDS WILL GUST PERIODICALLY TO AROUND 20KT WITH THE FRONT...THEN BECOME MORE CONSISTENT IN THE 20-25KT RANGE OUT OF THE WEST BEHIND THE FRONT TODAY. A FEW SHOWERS ARE POSSIBLE ALONG THE FRONT...MAINLY NORTH...AND DRYING ALOFT SHOULD LIMIT COVERAGE IN THE SOUTH. DESPITE CLEARING BEHIND THE FRONT...MODEST COLD ADVECTION WILL DOMINATE THE FIRST HALF OF THE DAY... KEEPING TEMPS FROM RISING MORE THAN 4-6 DEGREES ON MOST PLACES...RANGING FROM THE MID 40S NORTHWEST TO LOWER 50S SOUTHEAST. ANOTHER SHORTWAVE TROUGH DIGGING SOUTHEAST OUT OF CANADA WILL SWING ACROSS THE MID ATLANTIC STATES LATE TONIGHT. STRENGTHENING DPVA AND A BRIEF SHOT OF 60-80M HEIGHT FALLS FOCUSED ALONG THE NC/VA BORDER AND NORTHWARD...COMBINED WITH A BAND OF MID LEVEL MOISTURE CROSSING THE MOUNTAINS MAY BE SUFFICIENT TO CAUSE FLURRIES...MAINLY IN THE 09-12Z TIME FRAME. THE GFS HAS THE MOST ABUNDANT MOISTURE IN GENERAL...WITH MOISTURE REACHING TO -10C IN A BAND THAT SPANS THE ENTIRE CWA. HOWEVER...MOISTURE WITHIN THE ICE NUCLEATION ZONE IS ONLY PRESENT NORTH OF I-40 AND MOST PRONOUNCED NEAR THE NC/VA BORDER. THE LIMITED DURATION OF LIFT AND MOISTURE..AS WELL AS A RELATIVELY DRY BOUNDARY LAYER AND POTENTIAL FOR SUBLIMATION...WILL KEEP THIS TO A NO IMPACT EVENT. LOWS IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 150 PM WEDNESDAY... COLD FRONT WILL BE WELL OFFSHORE BY DAYBREAK WITH HIGH PRESSURE INITIALLY BUILDING ACROSS THE GULF STATES AND INTO THE REGION BEHIND THE FRONT. MILD ORIGIN OF THE HIGH AND ENSUING WESTERLY FLOW WILL ALLOW HIGHS ON THURSDAY TO REACH NEAR NORMAL...IN THE UPPER 40S TO LOWER 50S AND WINDS WILL BE DIMINISHING AS THE PRESSURE GRADIENT LOOSENS...LOOKING AT UP TO 15 MPH SUSTAINED WESTERLY WINDS WITH GUSTS TO PERHAPS 25 MPH. A REINFORCING SHORT WAVE WILL BE DIGGING INTO THE DOMINANT EAST COAST TROF LATE THURSDAY NIGHT...POSSIBLY SQUEEZING OUT SOME ISOLATED FLURRIES ALONG THE NORTHWEST TIER AS IT CROSSES THE MOUNTAINS. MINS THURSDAY NIGHT WILL BE AROUND 30...AND THE MAIN SENSIBLE IMPACT FROM THIS SHORT WAVE WILL BE TO SHARPEN THE NORTHWEST FLOW INTO THE TROF AND INITIATE STRONGER COLD AIR ADVECTION ON FRIDAY...WHEN HIGHS WILL STRUGGLE TO GET OUT OF THE 30S IN THE NORTHWEST...AND MAX OUT IN THE MID 40S IN THE SOUTHEAST. HIGH PRESSURE SETTLING OVERHEAD WILL LOCK THE COLD AIR IN OVERNIGHT...AND UNDER CLEAR SKIES...MINS FRIDAY NIGHT WILL BOTTOM OUT IN THE LOWER 20S. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 150 PM WEDNESDAY... MOSTLY CLEAR SKIES WITH HIGH PRESSURE OVERHEAD SATURDAY WILL ALLOW HIGH TEMPERATURES TO CLIMB BACK TOWARDS SEASONABLE READINGS...IN THE 45 TO 50 DEGREE RANGE. THIS HIGH WILL SHIFT QUICKLY OFFSHORE AND A FAST MOVING MID LEVEL CLIPPER SYSTEM WILL DIG INTO THE OHIO VALLEY ON SATURDAY NIGHT...POSSIBLY PRODUCING SOME LIGHT RAIN OR SNOW SHOWERS AS IT TRAVERSES THE AREA...WITH LITTLE TO NO ACCUMULATION. THE ASSOCIATED CLOUDINESS WILL PREVENT TEMPERATURES FROM CRASHING HARD SATURDAY NIGHT...HOWEVER...WITH SUNDAY MORNING LOWS AROUND 30. THE WARMER START AND INCREASING SUN EXPECTED ON SUNDAY WILL ALLOW HIGHS TO REBOUND FURTHER...INTO THE SEASONABLE LOWER 50S OVER MOST OF THE AREA. THE EAST COAST TROF AXIS SHIFTS OFFSHORE AND UPPER FLOW WILL NOT BE AS AMPLIFIED EARLY NEXT WEEK. ANOTHER REINFORCING BACKDOOR COLD FRONT WILL BE SLOWLY EDGING SOUTH AND POTENTIALLY STALLING ACROSS THE MID ATLANTIC ON TUESDAY INTO WEDNESDAY...BUT MOISTURE WILL BE LACKING AND FORCING WILL BE UNFOCUSED IN THE WEAKER UPPER FLOW. AT THIS POINT THE WEATHER MONDAY THROUGH WEDNESDAY LOOKS DRY AND SEASONABLY MILD WITH HIGHS MOSTLY IN THE LOW TO MID 50S EACH DAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1250 AM THURSDAY... SQUALL LINE CURRENTLY EXTENDS FROM KAVC TO KJNX TO BETWEEN KFAY AND KCTZ...MOVING EAST AT AROUND 30 MPH. STRONGEST SOUTHERLY WINDS CONTINUE ALONG AND AHEAD OF THE LINE WHERE 35-40KT GUSTS ARE REPORTED. HEAVY RAIN AND A SHORT PERIOD OF IFR/LIFR VSBYS AND CEILINGS WILL OCCUR AT KRWI BETWEEN 06Z AND 07Z. BEHIND THE LINE...SOUTHWESTERLY WINDS WILL CONTINUE TO GUST TO 25-30KT IMMEDIATELY BEHIND THE LINE...WITH THE STRONGEST GUSTS LIKELY TO ACCOMPANY SCATTERED SHOWERS THROUGH 09Z. THE MAIN COLD FRONT IS CURRENTLY CROSSING THE MOUNTAINS AND WILL CROSS THE AREAS BY 12Z. WINDS WILL TURN TO MORE WESTERLY WITH THE FRONT AS CEILINGS AND VSBYS RETURN TO VFR. WHILE THERE MAY BE A WEAKENING TREND IN WINDS...EXPECT THERE WILL STILL BE SOME SPORADIC WIND GUSTS THROUGH THE MORNING HOURS...WITH WIDESPREAD WIND GUSTS TO 20-25KT OUT OF THE WEST DURING THE DAY. OUTLOOK...VFR CONDITIONS ARE THEN EXPECTED TO PREVAIL THROUGH EARLY NEXT WEEK. ALTHOUGH...A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE AREA...ONE FRIDAY MORNING AND ONE SATURDAY NIGHT AND COULD PRODUCE A PERIOD OF INCREASED CLOUDINESS...WITH EVEN A SMALL POSSIBILITY OF SOME SPRINKLES OR FLURRIES. && .RAH WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY THROUGH 4 AM EST THIS MORNING FOR NCZ007>011-021>028-038>043-073>078-083>086-088-089. && $$ SYNOPSIS...CBL/SMITH NEAR TERM...SMITH SHORT TERM...MLM LONG TERM...MLM AVIATION...KRR/SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
115 AM EST THU JAN 31 2013 .SYNOPSIS... WINDY AND MILD CONDITIONS WILL CONTINUE AHEAD OF A STRONG COLD FRONT. FAST MOVING SHOWERS AND ISOLATED THUNDERSTORMS TONIGHT COULD PRODUCE LOCALIZED DAMAGING WIND GUSTS. DRY AND COOL CONDITIONS WILL FOLLOW THE FRONT THURSDAY THROUGH EARLY NEXT WEEK AS HIGH PRESSURE MOVES INTO THE REGION. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1045 PM WEDNESDAY...TORNADO WATCH REMAINS IN EFFECT FOR THE ENTIRE ILM CWA THRU 2 AM. MAIN ADJUSTMENT THIS UPDATE HAS BEEN APPLIED TO THE TIMING OF THE MAIN LINE OF CONVECTION CROSSING THE AREA. LATEST KLTX 88D TRENDS...RADAR MOSAIC OF THE SE U.S TRENDS...AND HRRR MODEL OUTPUT...INDICATE VERY LITTLE CONVECTION TO DEVELOP AHEAD OF THE APPROACHING LINE. THIS DUE TO A STABLE SFC BASED MARINE LAYER HAVING PROGRESSED WELL INLAND UNDER THE STRONG SSE-SSW LOW LEVEL WINDS. AT THIS POINT...DO NOT ANTICIPATE ANY ROGUE CONVECTIVE CELLS WELL AHEAD OF THIS LINE. HOWEVER...THE STRONG DYNAMICS ASSOCIATED WITH THE NEARLY SOLID LINE OF THE CONVECTION ITSELF CONTINUES TO WARRANT THE FORECAST OF STRONG TO SEVERE CONVECTION...WITH DAMAGING WIND GUSTS THE MAIN CONCERN. IN ADDITION...AN ISOLATED TORNADO REMAINS POSSIBLE DUE TO SUPPORTIVE DIRECTIONAL AND SPEED SHEAR ESPECIALLY AT THE LOWER LEVELS. THIS ILLUSTRATED NICELY BY 00Z UPPER AIR SOUNDING HODOGRAPHS. CONTINUED TWEAKING NEEDED FOR THE OVERNIGHT TEMP/DEWPT TRENDS...MAINLY DEALING WITH THE POST FRONTAL AIRMASS ADVECTING ACROSS THE FA LATE TONIGHT. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...STRONG WESTERLY WINDS WILL ADVECT MUCH COLDER AND DRIER AIR INTO REGION BEHIND EXITING COLD FRONT LOCATED WELL OFF THE COAST BY THURS MORNING. A VERY BROAD MID TO UPPER TROUGH WILL SHIFT EAST THROUGH THE PERIOD FINALLY LIFTING OFF TO THE NORTHEAST BY FRI NIGHT. AS THIS TROUGH MOVES EAST IT WILL DRIVE A SECONDARY BOUNDARY THROUGH THE AREA BY FRI MORNING. THIS WILL PROVIDE A REINFORCING SHOT OF COLD AND DRY AIR INTO THE AREA AS DEEP NW FLOW SETS UP ON FRIDAY. OVERALL A POTENT STORM SYSTEM WILL LIFT OFF TO THE NORTHEAST AS HIGH PRESSURE RIDGES UP FROM THE GULF COAST ON THURSDAY...BUT STRONG HIGH PRESSURE WILL BUILD DOWN FROM CANADA REACHING INTO THE CENTRAL CONUS BY THURS NIGHT AND SHIFTING EAST OVER THE LOCAL AREA BY LATE FRI INTO EARLY SAT. THIS WILL MAINTAIN A TIGHTENED GRADIENT FLOW THROUGH THURS AND THEN WINDS MAY BACK SLIGHTLY BEFORE NEXT DRY FRONTAL BOUNDARY MOVES THROUGH EARLY FRI WITH A SPIKE UP OF WINDS BEFORE FINALLY DIMINISHING AND VEERING MORE NORTH BY FRI NIGHT. THESE STRONG WEST TO NORTHWEST WINDS WILL MAINTAIN CAA THROUGH MUCH OF THE PERIOD. THERE WILL ONLY BE A BRIEF PERIOD OF MORE NEUTRAL ADVECTION AHEAD OF DRY COLD FRONT FRI MORNING. THEREFORE 850 TEMPS DROP FROM 13C JUST AHEAD OF INITIAL COLD FRONT EARLY THURS MORNING DOWN LESS THAN 0C BY THURS AFTN AND THEN WILL DROP AN ADDITIONAL SEVERAL DEGREES DOWN TO -8C BY FRI EVENING. TEMPS REACHING THE MID 50S...ALREADY 20 DEGREES COOLER THAN ON THURS...WILL HAVE TROUBLE REACHING INTO THE 50S ON FRI AS COLD ARCTIC HIGH PRESSURE BUILDS DOWN INTO THE AREA. OVERNIGHT LOWS WILL DROP DOWN TOWARD FREEZING THURS NIGHT IN CAA BUT FRI NIGHT TEMPS WILL PLUMMET ONCE WINDS DROP OFF IN THE EVENING. A MUCH MORE IDEAL RADIATIONAL COOLING NIGHT WILL OCCUR ON FRIDAY NIGHT AS HIGH SHIFTS OVERHEAD...MAKING FOR ONE OF THE COLDEST NIGHTS OF THE SEASON THUS FAR...WITH WIDESPREAD READINGS IN THE 20S. DRY AIR WILL RUN SIMILAR TO TEMPS WITH A MAJOR DROP OFF BEHIND FIRST FRONT AND THEN A PLATEAU AND MINOR INCREASE JUST AHEAD OF DRY POLAR COLD FRONT FRI MORNING AND THEN ANOTHER NOSE DIVE THROUGH FRI AFTN. THE PCP WATER DROP OFF FROM 1.6 INCHES VERY EARLY THURS MORNING DOWN TO A QUARTER OF AN INCH BY LATE THURS MORNING AND THEN DOWN CLOSE TO A TENTH OF AN INCH BY FRI AFTN. WITH SUCH A DRY AIR MASS IN PLACE...EXPECT SUNSHINE THROUGH MOST OF THE PERIOD. MAY SEE SOME CLOUDS WITH LINGERING MOISTURE THROUGH THURS MORNING AFTER RAINFALL FROM FRONT...AND A SLIGHT SPIKE AHEAD OF FRONT FRI MORNING. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY...A RATHER REPETITIVE PATTERN FOR THE EXTENDED AS AREAS OF HIGH PRESSURE PUSH OFFSHORE AHEAD OF A SERIES OF WEAK COLD FRONTS. FIRST OF THESE OCCURS SATURDAY AS DIFFUSE HIGH PRESSURE MOVES ACROSS THE AREA AND OFFSHORE...LEAVING A BRIEF PERIOD OF MOIST RETURN FLOW INTO THE CAROLINAS. THIS IS JUST IN ADVANCE OF A COLD FRONT WHICH WILL CROSS THE AREA VERY EARLY SUNDAY MORNING. LIMITED FORCING COMBINED WITH ONLY MARGINAL PWATS SUGGESTS FROPA WILL BE DRY...AND ONLY ACT TO REINFORCE THE COOL AIR. HOWEVER...ANY WEAK CAA REMAINS WELL DISPLACED BEHIND THE FRONT...SO SUNDAY WILL END UP BEING WARMER THAN SATURDAY...ALTHOUGH BOTH DAYS WILL BE AROUND TO SLIGHTLY BELOW CLIMO. ANOTHER LARGE BUT WEAK AREA OF HIGH PRESSURE BUILDS DOWN FROM THE NW LATE SUNDAY AND PERSISTS INTO TUESDAY WHILE SLOWLY DRIFTING ACROSS THE REGION. THIS CONTINUES THE COOL AND DRY WEATHER WITH NEAR TO SLIGHTLY-BELOW SEASONABLE TEMPS. THIS HIGH PRESSURE THEN DRIFTS OFFSHORE TUESDAY AHEAD OF ANOTHER COLD FRONT PROGGED TO CROSS THE AREA LATE IN THE DAY. GUIDANCE SHOWING CONSIDERABLE AMPLITUDE DIFFERENCES IN THE TROUGH DRIVING THIS FRONT WHICH WILL HAVE SIGNIFICANT IMPACT ON PRECIP POTENTIAL. FOR NOW WILL KEEP INHERITED SCHC/SILENT POP FOR D6 SINCE BENEFICIAL CHANGES CANNOT BE MADE AT THIS TIME. TUESDAY WILL LIKELY BE THE WARMEST DAY OF THE PERIOD THOUGH AHEAD OF THE COLD FRONT...WITH TEMPS RETURNING TO BELOW CLIMO FOR WEDNESDAY AS ANOTHER AREA OF HIGH PRESSURE RIDGES DOWN FROM THE NW. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 06Z...VFR WITH AREAS OF SHORT-LIVED MVFR/IFR AS SQUALL LINE WITH SHOWERS/ISOLATED THUNDERSTORMS CONTINUES TO PUSH ACROSS THE AREA OVER THE NEXT FEW HOURS. VFR EXPECTED THROUGH THE REMAINDER OF THE VALID TAF PERIOD AFTER 10Z. MAIN LINE OF SHOWERS IS NOW EAST OF KFLO/KLBT/KMYR...CURRENTLY AFFECTING KCRE...AND PROGRESSING EASTWARD. EXPECT THIS ACTIVITY TO REACH KILM WITHIN THE NEXT HOUR...BETWEEN 0645Z AND 0700Z. THIS SQUALL LINE HAS A HISTORY OF PRODUCING STRONG WINDS WITH SUSTAINED SPEEDS OF 20+ KTS AND GUSTS UP TO 40+ KTS...ALONG WITH SHORT-LIVED MVFR/IFR CONDITIONS DUE TO HEAVY RAIN. WITH CURRENT TREND AND GUIDANCE... EXPECT MAIN SQUALL LINE TO PUSH OFFSHORE BY 0715Z. AFTER THE PASSAGE OF THE COLD FRONT...THE AREA WILL SEE A SUDDEN WIND SHIFT...POST-FRONTAL RAIN POTENTIALLY CREATING MVFR/IFR CONDITIONS OVER THE NEXT FEW HOURS. HAVE INCLUDED LLWS IN CURRENT FCST...AND HAVE ISSUED AN AWW FOR KILM VALID UNTIL 0730Z FOR THE WINDSHIFT OF 60 DEGREES AND ASSOCIATED GUSTS UP TO 40+ KTS. CLEARING SKIES WILL LEAD TO VFR CONDITIONS ACROSS THE ENTIRE AREA BETWEEN 8-10Z. FOR THE REST OF THE PERIOD...EXPECT STRONG WESTERLY WINDS CONTINUING THROUGH THE AFTERNOON HOURS WITH GUSTS UP TO 25 KTS. GUSTS WILL SUBSIDE INTO THE EVENING HOURS. EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM WEDNESDAY...SFC PG WINDS CONTINUE TO OVERSPREAD THE COASTAL WATERS...WITH WINDS OF 15 TO 30 KT SPEEDS ACROSS THE NEAR SHORE WATERS DUE TO SSTS IN THE LOW 50S. ACROSS THE OUTER WATERS OF THE ILM CWA WHERE SSTS INCREASE TO AROUND 60 DEGREES...LOOK FOR HIGHER WIND SPEEDS OF 25 TO 40 KT. WITH THE INCREASING OF SSE- SSW WINDS THIS EVENING. ..BUILDING SHORT PERIOD SEAS HAVE FINALLY RESPONDED. IE. SEAS AT THE OCEAN CREST PIER HAVE NOW CLIMBED TO 7 FT...THE ONSLOW BAY AND FRYING PAN SHOALS BUOYS HAVE CLIMBED TO 12-13 FT RESPECTIVELY...WITH SSTS MEASURED AT BOTH THESE BUOYS OF 60 AND 68 DEGREES RESPECTIVELY. OVERALL...LOOK FOR THIS RANGE OF WINDS AND SEA CONDITIONS TO PERSIST ACROSS THE FA WATERS UNTIL THE PASSAGE OF THE COLD FRONT BETWEEN 1 AM AND 5 AM. OVERALL...BUILDING SIGNIFICANT SEAS HAVE LEVELED OFF FOR THE REMAINDER OF THE OVERNIGHT...WITH ADJUSTMENTS UPWARDS NEEDED FOR THURSDAY FOR THE ILM WATERS FROM CAPE FEAR SOUTH TO MURRELLS INLET DUE TO THE STRONG WSW-W WIND DIRECTIONS KEEPING THE SEAS AGITATED. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...ALTHOUGH SEAS WILL BE ON THE DECREASE THROUGH MUCH OF THE PERIOD IN STRONG OFF SHORE FLOW...TIGHTENED GRADIENT FLOW AND COLD SURGE BEHIND FRONT THURS AND AGAIN ON FRI WILL MAINTAIN SEAS ABOVE SCA THROUGH A GOOD PORTION OF THE SHORT TERM PERIOD IN THE OUTER WATERS. WESTERLY WINDS UP AROUND 25 KTS WILL DROP THROUGH THURS ALLOWING OFF SHORE SEAS TO SUBSIDE FROM 8 TO 10 FT FRI MORNING DOWN TO 5 FT BY THURS NIGHT. WINDS WILL BACK SLIGHTLY TO THE SW THURS NIGHT INTO EARLY FRI AHEAD OF APPROACHING DRY COLD FRONT BEFORE SPIKING UP IN SURGE BEHIND FRONT. THIS WILL PRODUCE SEAS AROUND 6 FT ONCE AGAIN FOR A FEW HOURS ON FRI. THE NEAR SHORE WATERS WILL DECREASE THROUGH THURS IN OFF SHORE FLOW DOWN TO 2 TO 4 FT AND MAY SPIKE UP A BIT FRI MORNING BUT OVERALL WILL DROP OFF SOME MORE LATE FRI AS HIGH PRESSURE SHIFTS OVERHEAD ALLOWING FOR LOCAL SEAS TO DROP TO 2 TO 3 FT IN ALL WATERS. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 300 PM WEDNESDAY...OTHER THAN A WEAK COLD FRONT SUNDAY...DIFFUSE HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE WATERS THROUGH THE EXTENDED. ONE AREA OF HIGH PRESSURE WILL MOVE ACROSS THE WATERS SATURDAY CREATING LIGHT AND VARIABLE WINDS...VEERING TO THE SW AND INCREASING TO AROUND 10 KTS LATE IN THE DAY. THIS AHEAD OF A COLD FRONT WHICH WILL CROSS DURING SUNDAY...TURNING WINDS TO THE W/NW AT 10-15 KTS ON SUNDAY BEFORE SLOWLY EASING TO LIGHT AND VARIABLE AGAIN MONDAY AS HIGH PRESSURE BUILDS BACK OVER THE WATERS. SEAS WILL BE PRIMARILY WIND-DRIVEN THROUGH THE PERIOD...1-2 FT SATURDAY AND MONDAY...INCREASING FOR A SHORT TIME SUNDAY UP TO 2-4 FT WITH A NW WIND WAVE DOMINANT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR SCZ017-023- 024-032-033-039-053>056. NC...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR NCZ087-096- 099-105>110. MARINE...GALE WARNING UNTIL 6 AM EST EARLY THIS MORNING FOR AMZ250-252- 254-256. && $$ SYNOPSIS...RGZ NEAR TERM...DCH SHORT TERM...RGZ LONG TERM...JDW AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1119 PM EST WED JAN 30 2013 .SYNOPSIS... WINDY AND MILD CONDITIONS WILL CONTINUE AHEAD OF A STRONG COLD FRONT. FAST MOVING SHOWERS AND ISOLATED THUNDERSTORMS TONIGHT COULD PRODUCE LOCALIZED DAMAGING WIND GUSTS. DRY AND COOL CONDITIONS WILL FOLLOW THE FRONT THURSDAY THROUGH EARLY NEXT WEEK AS HIGH PRESSURE MOVES INTO THE REGION. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 1045 PM WEDNESDAY...TORNADO WATCH REMAINS IN EFFECT FOR THE ENTIRE ILM CWA THRU 2 AM. MAIN ADJUSTMENT THIS UPDATE HAS BEEN APPLIED TO THE TIMING OF THE MAIN LINE OF CONVECTION CROSSING THE AREA. LATEST KLTX 88D TRENDS...RADAR MOSAIC OF THE SE U.S TRENDS...AND HRRR MODEL OUTPUT...INDICATE VERY LITTLE CONVECTION TO DEVELOP AHEAD OF THE APPROACHING LINE. THIS DUE TO A STABLE SFC BASED MARINE LAYER HAVING PROGRESSED WELL INLAND UNDER THE STRONG SSE-SSW LOW LEVEL WINDS. AT THIS POINT...DO NOT ANTICIPATE ANY ROGUE CONVECTIVE CELLS WELL AHEAD OF THIS LINE. HOWEVER...THE STRONG DYNAMICS ASSOCIATED WITH THE NEARLY SOLID LINE OF THE CONVECTION ITSELF CONTINUES TO WARRANT THE FORECAST OF STRONG TO SEVERE CONVECTION...WITH DAMAGING WIND GUSTS THE MAIN CONCERN. IN ADDITION...AN ISOLATED TORNADO REMAINS POSSIBLE DUE TO SUPPORTIVE DIRECTIONAL AND SPEED SHEAR ESPECIALLY AT THE LOWER LEVELS. THIS ILLUSTRATED NICELY BY 00Z UPPER AIR SOUNDING HODOGRAPHS. CONTINUED TWEAKING NEEDED FOR THE OVERNIGHT TEMP/DEWPT TRENDS...MAINLY DEALING WITH THE POST FRONTAL AIRMASS ADVECTING ACROSS THE FA LATE TONIGHT. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...STRONG WESTERLY WINDS WILL ADVECT MUCH COLDER AND DRIER AIR INTO REGION BEHIND EXITING COLD FRONT LOCATED WELL OFF THE COAST BY THURS MORNING. A VERY BROAD MID TO UPPER TROUGH WILL SHIFT EAST THROUGH THE PERIOD FINALLY LIFTING OFF TO THE NORTHEAST BY FRI NIGHT. AS THIS TROUGH MOVES EAST IT WILL DRIVE A SECONDARY BOUNDARY THROUGH THE AREA BY FRI MORNING. THIS WILL PROVIDE A REINFORCING SHOT OF COLD AND DRY AIR INTO THE AREA AS DEEP NW FLOW SETS UP ON FRIDAY. OVERALL A POTENT STORM SYSTEM WILL LIFT OFF TO THE NORTHEAST AS HIGH PRESSURE RIDGES UP FROM THE GULF COAST ON THURSDAY...BUT STRONG HIGH PRESSURE WILL BUILD DOWN FROM CANADA REACHING INTO THE CENTRAL CONUS BY THURS NIGHT AND SHIFTING EAST OVER THE LOCAL AREA BY LATE FRI INTO EARLY SAT. THIS WILL MAINTAIN A TIGHTENED GRADIENT FLOW THROUGH THURS AND THEN WINDS MAY BACK SLIGHTLY BEFORE NEXT DRY FRONTAL BOUNDARY MOVES THROUGH EARLY FRI WITH A SPIKE UP OF WINDS BEFORE FINALLY DIMINISHING AND VEERING MORE NORTH BY FRI NIGHT. THESE STRONG WEST TO NORTHWEST WINDS WILL MAINTAIN CAA THROUGH MUCH OF THE PERIOD. THERE WILL ONLY BE A BRIEF PERIOD OF MORE NEUTRAL ADVECTION AHEAD OF DRY COLD FRONT FRI MORNING. THEREFORE 850 TEMPS DROP FROM 13C JUST AHEAD OF INITIAL COLD FRONT EARLY THURS MORNING DOWN LESS THAN 0C BY THURS AFTN AND THEN WILL DROP AN ADDITIONAL SEVERAL DEGREES DOWN TO -8C BY FRI EVENING. TEMPS REACHING THE MID 50S...ALREADY 20 DEGREES COOLER THAN ON THURS...WILL HAVE TROUBLE REACHING INTO THE 50S ON FRI AS COLD ARCTIC HIGH PRESSURE BUILDS DOWN INTO THE AREA. OVERNIGHT LOWS WILL DROP DOWN TOWARD FREEZING THURS NIGHT IN CAA BUT FRI NIGHT TEMPS WILL PLUMMET ONCE WINDS DROP OFF IN THE EVENING. A MUCH MORE IDEAL RADIATIONAL COOLING NIGHT WILL OCCUR ON FRIDAY NIGHT AS HIGH SHIFTS OVERHEAD...MAKING FOR ONE OF THE COLDEST NIGHTS OF THE SEASON THUS FAR...WITH WIDESPREAD READINGS IN THE 20S. DRY AIR WILL RUN SIMILAR TO TEMPS WITH A MAJOR DROP OFF BEHIND FIRST FRONT AND THEN A PLATEAU AND MINOR INCREASE JUST AHEAD OF DRY POLAR COLD FRONT FRI MORNING AND THEN ANOTHER NOSE DIVE THROUGH FRI AFTN. THE PCP WATER DROP OFF FROM 1.6 INCHES VERY EARLY THURS MORNING DOWN TO A QUARTER OF AN INCH BY LATE THURS MORNING AND THEN DOWN CLOSE TO A TENTH OF AN INCH BY FRI AFTN. WITH SUCH A DRY AIR MASS IN PLACE...EXPECT SUNSHINE THROUGH MOST OF THE PERIOD. MAY SEE SOME CLOUDS WITH LINGERING MOISTURE THROUGH THURS MORNING AFTER RAINFALL FROM FRONT...AND A SLIGHT SPIKE AHEAD OF FRONT FRI MORNING. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY...A RATHER REPETITIVE PATTERN FOR THE EXTENDED AS AREAS OF HIGH PRESSURE PUSH OFFSHORE AHEAD OF A SERIES OF WEAK COLD FRONTS. FIRST OF THESE OCCURS SATURDAY AS DIFFUSE HIGH PRESSURE MOVES ACROSS THE AREA AND OFFSHORE...LEAVING A BRIEF PERIOD OF MOIST RETURN FLOW INTO THE CAROLINAS. THIS IS JUST IN ADVANCE OF A COLD FRONT WHICH WILL CROSS THE AREA VERY EARLY SUNDAY MORNING. LIMITED FORCING COMBINED WITH ONLY MARGINAL PWATS SUGGESTS FROPA WILL BE DRY...AND ONLY ACT TO REINFORCE THE COOL AIR. HOWEVER...ANY WEAK CAA REMAINS WELL DISPLACED BEHIND THE FRONT...SO SUNDAY WILL END UP BEING WARMER THAN SATURDAY...ALTHOUGH BOTH DAYS WILL BE AROUND TO SLIGHTLY BELOW CLIMO. ANOTHER LARGE BUT WEAK AREA OF HIGH PRESSURE BUILDS DOWN FROM THE NW LATE SUNDAY AND PERSISTS INTO TUESDAY WHILE SLOWLY DRIFTING ACROSS THE REGION. THIS CONTINUES THE COOL AND DRY WEATHER WITH NEAR TO SLIGHTLY-BELOW SEASONABLE TEMPS. THIS HIGH PRESSURE THEN DRIFTS OFFSHORE TUESDAY AHEAD OF ANOTHER COLD FRONT PROGGED TO CROSS THE AREA LATE IN THE DAY. GUIDANCE SHOWING CONSIDERABLE AMPLITUDE DIFFERENCES IN THE TROUGH DRIVING THIS FRONT WHICH WILL HAVE SIGNIFICANT IMPACT ON PRECIP POTENTIAL. FOR NOW WILL KEEP INHERITED SCHC/SILENT POP FOR D6 SINCE BENEFICIAL CHANGES CANNOT BE MADE AT THIS TIME. TUESDAY WILL LIKELY BE THE WARMEST DAY OF THE PERIOD THOUGH AHEAD OF THE COLD FRONT...WITH TEMPS RETURNING TO BELOW CLIMO FOR WEDNESDAY AS ANOTHER AREA OF HIGH PRESSURE RIDGES DOWN FROM THE NW. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... AS OF 00Z...STRONG COLD FRONT TO IMPACT THE TERMINALS TONIGHT WITH GUSTY WINDS AND A POTENTIAL SQUALL LINE WITH SHOWERS/ISOLATED THUNDERSTORMS. COLD FRONT CURRENTLY ACROSS WESTERN PORTIONS OF SC/NC WILL PUSH EAST TONIGHT AND BE ACCOMPANIED BY A LINE OF SHOWERS WITH ISOLATED THUNDERSTORMS. HRRR APPEARS TO BE INITIALIZING BETTER THAN ANY OF THE OTHER HIGH-RES GUIDANCE...SO HAVE RELIED HEAVILY ON THIS MODEL FOR TIMING CONVECTION AT THE TERMINALS...AND EXPECT THE SQUALL LINE TO IMPACT FLO/LBT AROUND 03Z...RACING EAST TO ILM AROUND 06Z. ATTM...NO IFR HAS BEEN INTRODUCED INTO THE CURRENT SET OF TAFS DUE TO UNCERTAINTY IN EXACT TIMING AND LIKELY SHORT-DURATION OF ANY PRECIP INDUCED IFR. PREFER TO HANDLE ANY IFR WITH AMD/TEMPO GROUPS AS THE CONVECTION UNFOLDS. HAVE SHOWN A 2-HR TEMPO GROUP AT ALL TERMINALS FOR THE HEAVIEST CONVECTION WITH MVFR AND INCREASED WIND GUSTS...BUT STRONGER GUSTS ARE POSSIBLE THAN WHAT IS CURRENTLY DEPICTED. OTHER CONCERN IS THE STRONG PRE-FRONTAL AND POST-FRONTAL WINDS. S/SW WINDS WILL CONTINUE TO INCREASE TONIGHT AS A STRENGTHENING LOW LEVEL JET MOVES OVERHEAD. FOR THIS REASON HAVE SHOWN INCREASING LLWS IN ALL TAFS WITH 30 KT GUSTS LIKELY THROUGH THE NIGHT...EVEN OUTSIDE OF CONVECTION. A SUDDEN WIND SHIFT WILL OCCUR WITH THE FROPA TONIGHT...AND AWWS MAY BE REQUIRED FOR ILM/MYR LATER TONIGHT AS THE FRONT CROSSES...AND WINDS SHIFT SUDDENLY TO THE WEST. RAPID DRYING OCCURS BEHIND THE FRONT AND SKC WILL BECOME THE SKY CONDITION ON THURSDAY. ALTHOUGH IT WILL BE CLEAR...STRONG WESTERLY WINDS WILL PERSIST THROUGH THE DAY...GUSTING TO 25 KTS THROUGH THE END OF THE VALID PERIOD. EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM WEDNESDAY...SFC PG WINDS CONTINUE TO OVERSPREAD THE COASTAL WATERS...WITH WINDS OF 15 TO 30 KT SPEEDS ACROSS THE NEAR SHORE WATERS DUE TO SSTS IN THE LOW 50S. ACROSS THE OUTER WATERS OF THE ILM CWA WHERE SSTS INCREASE TO AROUND 60 DEGREES...LOOK FOR HIGHER WIND SPEEDS OF 25 TO 40 KT. WITH THE INCREASING OF SSE- SSW WINDS THIS EVENING. ..BUILDING SHORT PERIOD SEAS HAVE FINALLY RESPONDED. IE. SEAS AT THE OCEAN CREST PIER HAVE NOW CLIMBED TO 7 FT...THE ONSLOW BAY AND FRYING PAN SHOALS BUOYS HAVE CLIMBED TO 12-13 FT RESPECTIVELY...WITH SSTS MEASURED AT BOTH THESE BUOYS OF 60 AND 68 DEGREES RESPECTIVELY. OVERALL...LOOK FOR THIS RANGE OF WINDS AND SEA CONDITIONS TO PERSIST ACROSS THE FA WATERS UNTIL THE PASSAGE OF THE COLD FRONT BETWEEN 1 AM AND 5 AM. OVERALL...BUILDING SIGNIFICANT SEAS HAVE LEVELED OFF FOR THE REMAINDER OF THE OVERNIGHT...WITH ADJUSTMENTS UPWARDS NEEDED FOR THURSDAY FOR THE ILM WATERS FROM CAPE FEAR SOUTH TO MURRELLS INLET DUE TO THE STRONG WSW-W WIND DIRECTIONS KEEPING THE SEAS AGITATED. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...ALTHOUGH SEAS WILL BE ON THE DECREASE THROUGH MUCH OF THE PERIOD IN STRONG OFF SHORE FLOW...TIGHTENED GRADIENT FLOW AND COLD SURGE BEHIND FRONT THURS AND AGAIN ON FRI WILL MAINTAIN SEAS ABOVE SCA THROUGH A GOOD PORTION OF THE SHORT TERM PERIOD IN THE OUTER WATERS. WESTERLY WINDS UP AROUND 25 KTS WILL DROP THROUGH THURS ALLOWING OFF SHORE SEAS TO SUBSIDE FROM 8 TO 10 FT FRI MORNING DOWN TO 5 FT BY THURS NIGHT. WINDS WILL BACK SLIGHTLY TO THE SW THURS NIGHT INTO EARLY FRI AHEAD OF APPROACHING DRY COLD FRONT BEFORE SPIKING UP IN SURGE BEHIND FRONT. THIS WILL PRODUCE SEAS AROUND 6 FT ONCE AGAIN FOR A FEW HOURS ON FRI. THE NEAR SHORE WATERS WILL DECREASE THROUGH THURS IN OFF SHORE FLOW DOWN TO 2 TO 4 FT AND MAY SPIKE UP A BIT FRI MORNING BUT OVERALL WILL DROP OFF SOME MORE LATE FRI AS HIGH PRESSURE SHIFTS OVERHEAD ALLOWING FOR LOCAL SEAS TO DROP TO 2 TO 3 FT IN ALL WATERS. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 300 PM WEDNESDAY...OTHER THAN A WEAK COLD FRONT SUNDAY...DIFFUSE HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE WATERS THROUGH THE EXTENDED. ONE AREA OF HIGH PRESSURE WILL MOVE ACROSS THE WATERS SATURDAY CREATING LIGHT AND VARIABLE WINDS...VEERING TO THE SW AND INCREASING TO AROUND 10 KTS LATE IN THE DAY. THIS AHEAD OF A COLD FRONT WHICH WILL CROSS DURING SUNDAY...TURNING WINDS TO THE W/NW AT 10-15 KTS ON SUNDAY BEFORE SLOWLY EASING TO LIGHT AND VARIABLE AGAIN MONDAY AS HIGH PRESSURE BUILDS BACK OVER THE WATERS. SEAS WILL BE PRIMARILY WIND-DRIVEN THROUGH THE PERIOD...1-2 FT SATURDAY AND MONDAY...INCREASING FOR A SHORT TIME SUNDAY UP TO 2-4 FT WITH A NW WIND WAVE DOMINANT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...WIND ADVISORY UNTIL 6 AM EST THURSDAY FOR SCZ017-023-024-032- 033-039-053>056. NC...WIND ADVISORY UNTIL 6 AM EST THURSDAY FOR NCZ087-096-099- 105>110. MARINE...GALE WARNING UNTIL 6 AM EST THURSDAY FOR AMZ250-252-254-256. && $$ SYNOPSIS...RGZ NEAR TERM...DCH SHORT TERM...RGZ LONG TERM...JDW AVIATION...JDW/SGL
AREA FORECAST DISCUSSION
NWS PORTLAND OR
843 AM PST THU JAN 31 2013 .SYNOPSIS...ONE LAST SYSTEM MOVING OVER THE TOP OF AN OFFSHORE HIGH PRESSURE WILL BRING SOME LIGHT RAIN TO THE NORTHERN TIER TODAY. STRENGTHENING HIGH PRESSURE WILL BRING DRY WEATHER FOR AT LEAST FRIDAY AND SATURDAY...THOUGH THERE WILL BE PLENTY OF LOW CLOUDS AND FOG ACROSS THE INTERIOR VALLEYS. EAST WINDS WILL INCREASE ACROSS THE WESTERN COLUMBIA RIVER GORGE LATE FRIDAY LIKELY CAUSING THE PORTLAND METRO AREA TO CLEAR THOUGH. SYSTEMS LATE THIS WEEKEND AND EARLY NEXT WEEK APPEAR WEAK...WITH BETTER CHANCES OF PRECIPITATION AROUND THE MIDDLE OF NEXT WEEK. && .SHORT TERM...DOPPLER RADAR MOSAIC SHOWS A BAND OF LIGHT RAIN MOVING INTO SOUTHWEST WASHINGTON AND EXTREME NORTHWESTERN OREGON. THIS RAIN IS ASSOCIATED WITH AN AREA OF ISENTROPIC LIFT ACCOMPANYING A WEAK FRONT PUSHING SOUTHEASTWARD. AS THIS FRONT DETACHES FROM ITS PARENT UPPER LEVEL TROUGH OVER BRITISH COLUMBIA...EXPECT IT TO STALL AND WEAKEN IN THE VICINITY OF THE COLUMBIA RIVER THIS AFTERNOON AND TONIGHT...AS IT BECOMES ORIENTED MORE LATITUDINALLY. THE CURRENT PRECIPITATION BAND IS A LITTLE MORE EXTENSIVE AND ARRIVING EARLIER THAN MOST MODELS WOULD SEEM TO SUGGEST...EVEN THE SHORT TERM MODELS. THE LATEST HRRR SUGGESTS A SHOWER OR TWO WILL BE POSSIBLE ACROSS THE PORTLAND METRO AREA LATER THIS AFTERNOON AND GIVEN THE SOUTHWARD EXTENT OF PRECIPITATION ON RADAR...THIS IDEA SEEMS PLAUSIBLE. AS A RESULT OF THE ABOVE...POPS WERE INCREASED FOR TODAY...AND GRIDS WERE SPLIT INTO THREE HOURS TO ATTEMPT TO REFLECT THE LATEST TIMING AND TRENDS IN RAIN CHANCES. THE OTHER PROBLEM CHILD THIS MORNING ARE AREAS OF FOG ACROSS THE PORTLAND METRO AREA. GIVEN PORTIONS OF THE METRO AREA...SUCH AS DOWNTOWN...REMAIN FOG FREE...WILL CONTINUE TO HANDLE THE FOG PROBLEM WITH NOWCASTS. GIVEN THE LOW SUN ANGLE AND LIGHT LOW LEVEL FLOW...I DID EXPAND THE FOG MENTION IN THE GRIDS UNTIL 1 PM AS IT WILL LIKELY BE SLOW TO LIFT AND MIX OUT. SKY COVER GRIDS WERE TWEAKED AS WELL FURTHER SOUTH AS AREA CAMS AND THE FIRST VISIBLE SATELLITE IMAGES OF THE DAY INDICATE MOSTLY SUNNY TO PARTLY CLOUDY SKIES EXIST ACROSS THE CENTRAL OREGON COAST AND THE CENTRAL OREGON CASCADES. /NEUMAN .LONG TERM...SATURDAY NIGHT THROUGH TUESDAY...THE UPPER LEVEL RIDGE IN PLACE TO START THE WEEKEND BEGINS TO BREAK DOWN SLOWLY TOWARD LATE SATURDAY AS A WEAK BOUNDARY APPROACHES THE AREA. THIS BOUNDARY WILL AT THE LEAST BRING INCREASING CLOUDS TO THE AREA BY SUNDAY...BUT IT WILL BE SHEARING AND SPLITTING...SO EXPECT RAIN CHANCES TO BE ON THE LOW END. A QUICK MOVING BUT STRONGER FRONTAL SYSTEM WILL THEN APPROACH THE COAST LATE SUNDAY INTO MONDAY. THIS SYSTEM SEEMS TO FURTHER BREAK DOWN THE RIDGE...BUT MODELS DISAGREE ON HOW MUCH MOISTURE IT PUSHES INLAND...BEFORE THE RIDGE REBOUNDS ON MONDAY AFTERNOON. ANOTHER FRONTAL SYSTEM IS SHOWN TO SWING THROUGH THE AREA LATER IN THE DAY TUESDAY OR TUESDAY EVENING. A COLD UPPER TROUGH WILL THEN MOVE THROUGH FOR THE LATTER HALF OF THE WEEK. KMD/BROWN && .AVIATION...FLIGHT CONDITIONS REMAIN VARIABLE THIS MORNING... RANGING ANYWHERE FROM LIFR TO VFR CATEGORY. MOIST LOW LEVELS IN A LIGHT ONSHORE FLOW ARE LIKELY TO KEEP A VARIETY OF CONDITIONS ACROSS THE AREA. OVERALL TREND IN THE AFTERNOON IS LIKELY TO BE FOR SLOW IMPROVEMENT TO PREDOMINANTLY MVFR IN THE NORTH AND AND VFR CATEGORY IN THE SOUTH. EXPECT A RETURN TO IFR CONDITIONS ACROSS MUCH OF THE INTERIOR TONIGHT WITH A MIX OF MVFR AND IFR CONDITIONS ALONG THE COAST. KPDX AND APPROACHES...IFR AND LIFR CONDITIONS WILL CONTINUE THIS MORNING. CONDITIONS WILL LIKELY IMPROVE TO MVFR AFTER 20Z TODAY. IFR CONDITIONS ARE LIKELY TO RE-DEVELOP AFTER 08Z TONIGHT AS THE AIRMASS STABILIZES. && .MARINE...FAIRLY QUIET NEXT COUPLE OF DAYS AS A HIGH PRES SYSTEM IS LIKELY TO KEEP WINDS BELOW SMALL CRAFT CRITERIA THROUGH THE WEEKEND. A LONG PERIOD SWELL OUT OF THE W IS EXPECTED TO BEGIN SHOWING UP FRI...AND ULTIMATELY RAISE SEAS ABOVE 10 FT ON SAT AND SUN. ALTHOUGH THE OFFSHORE WAVE HEIGHTS ARE EXPECTED TO PEAK IN THE 10 TO 12 FT RANGE SAT AND SUN...THE LONG PERIODS MAY PUSH BREAKERS AS HIGH AS THE 18 TO 20 FT RANGE. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 AM PST THIS MORNING. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 PM THIS AFTERNOON TO 9 PM PST THIS EVENING. && $$ MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
521 PM CST FRI FEB 1 2013 .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT 345 PM CDT FRI FEB 1 2013 AT 3 PM...THE WATER VAPOR IMAGERY SHOWED A SHORT WAVE TROUGH MOVING SOUTHEAST THROUGH LAKE WINNIPEG. AT THE THE SURFACE...A COLD FRONT...LOCATED JUST SOUTH OF LAKE WINNE PEG...WAS PRODUCING SNOW ACROSS THE EASTERN DAKOTAS...AND NORTHWEST AND WEST CENTRAL MINNESOTA. THIS SNOW WAS REDUCING VISIBILITIES TO 3/4 MILES AT FARGO NORTH DAKOTA. FOR TONIGHT...THE 01.12Z MESO AND DETERMINISTIC MODELS ARE IN GOOD AGREEMENT THAT SHORT WAVE TROUGH AND COLD FRONT TO OUR NORTHWEST WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA THIS EVENING AND EARLY OVERNIGHT. MODERATE 270 TO 280K ISENTROPIC LIFT /2 TO 4 MICROBARS/SEC/ DEVELOPS AHEAD OF THIS SYSTEM. THIS IS BRINGING THE WARMER AND MORE MOIST /DEW POINTS IN THE LOWER AND MID 20S/ AIR ALOFT. THIS WARMS THE ATMOSPHERIC COLUMN INTO THE DENDRITIC GROWTH ZONE AND THE MOISTURE SATURATES IT. 01.09Z SREF SHOWS THAT 50 TO 70 PERCENT OF THE ENSEMBLE FAMILY HAS OVER 200 MB OF DENDRITIC GROWTH THIS EVENING. THE ROCHESTER RAP BUFKIT SOUNDING SHOWS AT LEAST 10K FEET IN THE DENDRITIC GROWTH ZONE BETWEEN 02.00Z AND 02.06Z. MEANWHILE THE GFS AND NAM BUFKIT SOUNDINGS HAVE A MUCH SHORTER TIME. THIS WILL AFFECT THE SNOW RATIOS. THE RAP WOULD SUGGEST 25-30 TO 1 SNOW TO LIQUID RATIOS. MEANWHILE THE GFS AND NAM WOULD SUGGEST 17-23 TO 1 SNOW TO LIQUID RATIOS. SINCE THE SYSTEM IS MOVING SO FAST...TRENDED MORE TOWARD THE GFS AND NAM SOLUTIONS. THIS WOULD PRODUCE A 1 TO 2 INCH SNOW BAND ACROSS NORTHEAST IOWA AND AND SOUTHWEST WISCONSIN...AND AROUND AN INCH NORTHWARD TO WISCONSIN 10. ON SATURDAY AFTERNOON AND NIGHT...ANOTHER SHORT WAVE TROUGH WILL MOVE SOUTHEAST THROUGH THE REGION. UNLIKE YESTERDAY...HAS THE LEFT ENTRANCE REGION OF THE 250 MB JET A BIT FURTHER SOUTHEAST. AS A RESULT...THE OMEGA IS NOT AS STRONG OR DEEP AS IT WAS YESTERDAY. DESPITE THIS THERE IS MODERATE 270 TO 280K LIFT AHEAD OF THIS WAVE AND THIS WILL ONCE AGAIN BRING SOME MOISTURE AND WARMER AIR ALOFT FROM THE NORTHERN AND CENTRAL PLAINS. HOWEVER 01.09Z SREF SHOWS FEWER MEMBERS HAVING 200 MB OR GREATER OF DENDRITIC GROWTH. THE COBB DATA SUGGESTS 17-22 TO 1 SNOW TO LIQUID RATIOS. THIS WOULD RESULT IN AROUND AN INCH OF SNOW FOR MUCH OF THE AREA. FROM LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT...THE MODELS SHOW YET ANOTHER SHORT WAVE TROUGH WILL BE MOVING SOUTHEAST THROUGH THE REGION. BY THIS TIME...THE AIR MASS WILL BE A BIT WARMER. AS A RESULT...THE BEST ISENTROPIC LIFT IS TAKING PLACE BETWEEN 280 AND 300K. WITH THE AIR MASS WARMER...THERE IS LESS OF A LAYER IN DENDRITIC GROWTH ZONE. HOWEVER THERE IS A BIT MORE MOISTURE FOR THIS SYSTEM TO WORK WITH...SO IT LOOKS LIKE SNOW TOTALS WILL RANGE FROM 1 TO 2 INCHES. OVERALL...IT LOOKS LIKE SNOW TOTALS DURING THE NEXT 3 DAYS WILL RANGE FROM 2 TO 5 INCHES. .LONG TERM...MONDAY THROUGH FRIDAY 345 PM CDT FRI FEB 1 2013 ON MONDAY NIGHT AND TUESDAY MORNING...ANOTHER SHORT WAVE WILL BE MOVING SOUTHEAST THROUGH THE REGION. LIKE THE SYSTEM ON SUNDAY AND SUNDAY NIGHT...THERE IS NOT MUCH OF THE THE ATMOSPHERIC COLUMN IN THE DENDRITIC GROWTH ZONE...BUT THERE IS MORE MOISTURE FOR THIS SYSTEM TO WORK WITH. AS A RESULT...THE SNOW TO LIQUID RATIOS LOOK TO BE 15-20 TO 1. WITH A TENTH TO 2 TENTHS OF INCH OF QPF...THERE COULD BE THE POTENTIAL OF ANOTHER 1 TO 3 INCHES OF SNOW. IT STILL LOOKS LIKE ANOTHER SYSTEM WILL AFFECT THE AREA FROM WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THE MODELS HAVE BEEN MUCH LESS CONSISTENT WITH THEIR PRECIPITATION AMOUNTS AND THE LOCATION OF THIS SYSTEMS WARM FRONT. AS A RESULT...THERE IS MUCH LESS CERTAINTY THAN THE PREVIOUS 4 SYSTEMS. && .AVIATION...TONIGHT AND SATURDAY 521 PM CST FRI FEB 1 2013 A WEAK AREA OF LOW PRESSURE IS OVER NORTH CENTRAL NEBRASKA LATE THIS AFTERNOON WITH A WARM FRONT ACROSS NORTHERN IOWA. WATER VAPOR SATELLITE SHOWS A SHORT WAVE TROUGH ASSOCIATED WITH THE SURFACE LOW MOVING INTO WESTERN MINNESOTA. THE SHORT WAVE TROUGH IS NOT VERY STRONG AS EVIDENCE BY THE 4 TO 8 PVU/S OF VORTICITY ADVECTION IT IS EXPECTED TO GENERATE IN THE 500-300 MB LAYER BUT IT SHOULD STILL GENERATE A SHORT PERIOD OF WEAK TO MODERATE QG CONVERGENCE IN THE 850 TO 500 MB LAYER. NORTH OF THE WARM FRONT...WEAK FRONTOGENESIS IN THE 850-500 MB LAYER ALONG WITH 2 TO 4 UBAR/S OF UP GLIDE ON THE 275K ISENTROPIC SURFACE WILL COMBINE WITH THE FORCING FROM THE WAVE TO PRODUCE A PERIOD OF SNOW. CONDITIONS IN THE SNOW OVER CENTRAL MINNESOTA ARE PRIMARILY MVFR WITH SOME REDUCTION TO A MILE OR LESS WITH THE VISIBILITY. HAVE BROUGHT THESE CONDITIONS IN FOR THE EVENING AT BOTH TAF SITES. OBSERVATIONS BEHIND THE SNOW BAND INDICATE A RETURN TO PRIMARILY VFR CONDITIONS WITH NO RESTRICTIONS ON THE VISIBILITY AND CEILINGS OF 3 TO 4K FEET. THE NEXT SYSTEM WILL QUICKLY ADVANCE INTO THE REGION SATURDAY AFTERNOON ON THE NORTHWEST FLOW ALOFT. CURRENT INDICATIONS ARE THAT THE MAIN SNOW BAND FROM THIS WAVE MAY GO TO THE SOUTHWEST OF THE TAF SITES BUT STILL ENOUGH TO DROP KRST BACK TO MVFR LATE SATURDAY AFTERNOON. KLSE SHOULD SEE THIS NEXT BAND OF SNOW MOVE IN RIGHT AROUND 00Z AND THIS WILL BE ADDED WITH THE NEXT FORECAST. && .ARX WATCHES/WARNINGS/ADVISORIES... 344 PM CST FRI FEB 1 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
416 AM EST SAT FEB 2 2013 .SYNOPSIS... HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN QUEBEC THIS MORNING. A CLIPPER LOW WILL APPROACH FROM THE LOWER GREAT LAKES REGION WITH ISOLATED TO SCATTERED SNOW SHOWERS LATE THIS AFTERNOON INTO THIS EVENING. ANOTHER CLIPPER WILL IMPACT THE REGION LATE SUNDAY INTO SUNDAY NIGHT WITH SOME LIGHT SNOW AND CONTINUED BELOW NORMAL TEMPERATURES TO OPEN NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 345 AM EST...THE LAKE EFFECT SNOWS HAVE ENDED SOUTH AND WEST OF THE CAPITAL REGION...AS HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SRN QUEBEC THIS MORNING. A WEAK STATIONARY BOUNDARY OVER UPSTATE NY AND NEW ENGLAND WILL LIFT BACK NORTHWARD AHEAD OF A WEAK LOW PRESSURE SYSTEM OVER GEORGIAN BAY. THE LOW AND MID LEVEL FLOW WILL BACK TO THE W/SW...AND LAKE EFFECT SNOWFALL WILL BREAK OUT OVER EXTREME NRN NY OFF LAKE ONTARIO. A SW FLOW TRAJECTORY WILL NOT IMPACT THE ALY FCST AREA MUCH. THE 240 DEGREE TRAJECTORY IS EXPECTED TO IMPACT LOCATIONS JUST NORTH AND WEST OF THE WRN DACKS. THE LATEST ALY HIRES WRF COMPOSITE REFLECTIVITY...AND 3-KM HRRR SHOW LITTLE IMPACT IN OUR AREA TODAY. WE KEPT SOME HIGH CHC AND LIKELY POPS NORTH OF OLD FORGE IN HERKIMER COUNTY...AND NW HAMILTON COUNTIES. THERE IS SOME WEAK WARM ADVECTION WITH THE BOUNDARY TOO...SO SOME SLIGHT AND LOW CHC POPS WERE EXPANDED SOUTH TO THE W-CNTRL MOHAWK VALLEY. ANOTHER CLIPPER LOW MOVING ACROSS WI/IL THIS MORNING WILL APPROACH THE REGION FOR LATE THIS AFTERNOON...AND TONIGHT WITH SOME SCATTERED SNOW SHOWERS OR LIGHT SNOW. THE SHORT-WAVE TO THIS CLIPPER IS MOVING INTO THE MIDWEST THIS MORNING VIA THE WATER VAPOR LOOP. CHC POPS WERE EXPANDED OVER MOST OF THE FCST AREA LATE THIS AFTERNOON INTO EARLY THIS EVENING. DESPITE WEAK LOW TO MID LEVEL WARM ADVECTION...H850 TEMPS WILL STILL BE -12C TO -16C FROM SOUTH TO NORTH OVER THE CWA. EXPECT HIGHS TO BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS IN THE MID TO U20S IN THE CAPITAL DISTRICT...THE MID HUDSON VALLEY...AND CT VALLEY. EXPECT TEENS TO L20S OVER THE MTNS...LAKE GEORGE REGION...W-CNTRL MOHAWK VALLEY...SRN VT...AND THE LITCHFIELD HILLS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... TONIGHT...THE FIRST OF TWO CLIPPERS PASSES SOUTH OF THE REGION WITH SCT SNOW SHOWERS/LIGHT SNOW ENDING FROM NORTH TO SOUTH. EXPECT MAINLY COATINGS TO A HALF AN INCH AROUND THE REGION. PORTIONS OF THE ERN CATSKILLS...AND WRN ADIRONDACKS COULD SEE AROUND AN INCH OR SO. THE FLOW VEERS TO THE W/NW AGAIN WITH THE UPPER LEVEL TROUGH OVER CNTRL-ERN CANADA CONTINUING TO THE DRIVE THE WX OVER NY AND NEW ENGLAND. MIN TEMPS WERE BLENDED FROM THE MET/MAV GUIDANCE WITH SINGLE DIGITS NORTH OF THE CAPITAL REGION...AND THE MOHAWK VALLEY...AND TEENS FROM THE I-90 CORRIDOR SOUTH AND EAST. SUNDAY-SUNDAY NIGHT...ANOTHER LULL IS BRIEFLY EXPECTED IN THE PARADE OF SHORT-WAVES/CLIPPERS IN THE W/NW FLOW ALOFT SUNDAY MORNING. THE GUIDANCE HAS TRENDED A BIT SLOWER WITH THE NEXT CLIPPER. SOME SLIGHT CHC POPS WERE PUT IN DURING THE LATE MORNING WEST OF THE HUDSON RIVER VALLEY...AND THEN CHC POPS WERE PUT IN EVERYWHERE IN THE PM INTO THE EVENING. THIS CLIPPER AND ITS ASSOCIATED SHORT- WAVE MOVE ACROSS THE CNTRL-ERN GREAT LAKES INTO THE REGION. THEIR IS SOME PRONOUNCED CYCLONIC VORTICITY ADVECTION WITH IT. THE DISTURBANCE WILL PRODUCE A ROUND OF LIGHT SNOW FOR THE REGION WITH GENERALLY A DUSTING TO AN INCH OR SO IN MOST LOCATIONS. THE SHORT- WAVE ENERGY WITH THIS CLIPPER WILL LIKELY PHASE WITH A STORM EAST OF THE GULF OF MAINE SUNDAY NIGHT. THE STORM WILL INTENSIFY AND DEEPEN NEAR THE CANADIAN MARITIMES. SOME WESTERLY UPSLOPE OR LAKE EFFECT SNOWFALL MAY IMPACT THE SRN GREENS AND WRN DACKS. WE HAVE 1-4" OF SNOW SUNDAY TO SUNDAY NIGHT IN THESE AREAS. HIGHS WILL RANGE FROM THE 20S TO L30S ACROSS THE REGION...TO SINGLE DIGITS TO TEENS FOR LOWS. MONDAY-MONDAY NIGHT...THE WORK WEEK WILL OPEN WITH BLUSTERY AND COLD CONDITIONS...AS A DEEPENING AND INTENSIFYING LOW PRESSURE SYSTEM MOVES TOWARD LABRADOR...AND ARCTIC HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES REGION AND ONTARIO. W/NW WINDS OF 15 TO 25 MPH WILL BE COMMON WITH SOME GUSTS AROUND 30-40 MPH. WESTERLY UPSLOPE SNOW SHOWERS OVER THE SRN GREENS AND WRN DACKS WILL END DURING THE AFTERNOON WITH ADDITIONAL LIGHT ACCUMULATIONS. IN THE COLD ADVECTION REGIME...H850 TEMPS FALL TO -17C TO -22C. MAX TEMPS WILL CONTINUE TO RUN BELOW NORMAL WITH TEENS TO M20S OVER THE HILLS AND MTNS...AND L20S TO L30S IN THE VALLEY AREAS. TEMPS MAY FALL DURING THE AFTERNOON. DIMINISHING WINDS AND FRIGID CONDITIONS ARE ANTICIPATED MON NIGHT WITH HIGH PRESSURE BUILDING IN WITH LOWS BELOW ZERO OVER THE ADIRONDACK PARK...AND SRN GREENS...SINGLE DIGITS EVERYWHERE ELSE...EXCEPT 10-15F IN THE MID HUDSON VALLEY AND SRN LITCHFIELD COUNTY. && .LONG TERM /TUESDAY THROUGH FRIDAY/... MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT KEEPING THE REGION UNDER A LONGWAVE TROUGH. A SHORT WAVE IS FORECAST TO MOVE THROUGH THE BASE OF THE TROUGH TUESDAY NIGHT INTO WEDNESDAY BRINGING THE THREAT FOR SOME SNOW SHOWERS. THE FLOW ALOFT IS EXPECTED TO BECOME MORE ZONAL WITH RIDGING BUILDING IN AT THE SURFACE AND IN THE LOW LEVELS OF THE ATMOSPHERE FOR THURSDAY BETWEEN SHORT WAVES AS THE UPPER LOW OVER EASTERN CANADA/HUDSONS BAY SHIFTS A BIT NORTHWARD. THE SURFACE HIGH WILL WEAKEN AND SHIFT EASTWARD AS ANOTHER SHORT WAVE TROUGH APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT. THE UPPER TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SHOULD CROSS THE REGION FRIDAY BRINGING WIDESPREAD CHANCES FOR SNOW SHOWERS. QPF SHOULD BE LIGHT SINCE MOISTURE ASSOCIATED WITH THE FEATURES WILL BE FAIRLY LIMITED. AS FOR TEMPERATURES LOOKING AT AROUND SEASONABLE LEVELS FOR EARLY FEBRUARY. SHOULD WARM TO A BIT ABOVE NORMAL ON FRIDAY AHEAD OF THE APPROACHING LOW PRESSURE SYSTEM. NORMALS FEB 5TH-8TH: ALBANY: HIGHS LOWER 30S. LOWS MID TEENS. GLENS FALLS: HIGHS LOWER 30S. LOWS UPPER SINGLE DIGITS. POUGHKEEPSIE: HIGHS UPPER 30S. LOWS UPPER TEENS. BENNINGTON: HIGHS LOWER 30S. LOWS MID TEENS. PITTSFIELD: HIGHS AROUND 30. LOWS MID TEENS. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... HIGHER PRESSURE BRIEFLY BUILDS INTO THE REGION FROM THE SOUTHWEST THIS MORNING AND THE LAKE EFFECT SNOW WILL DISSIPATE. A CLIPPER LOW WILL APPROACH FROM THE GREAT LAKES REGION TODAY AND IS EXPECTED TO WEAKEN AS IT MOVES OVER THE REGION TONIGHT. EXPECTING VFR CONDITIONS...THE EXCEPTION WILL BE MVFR CONDITIONS AT KPSF FOR A COUPLE HOURS AT THE BEGINNING OF THE TAF TIME AND POSSIBLY AGAIN LATE IN THE EVENING. GUSTY WEST TO NORTHWEST WINDS AT KALB AND KPSF WILL WEAKEN EARLY THIS MORNING. THE FLOW WILL SHIFT TO SOUTHWEST TO SOUTH DURING THE DAY AHEAD OF THE APPROACHING CLIPPER LOW. OUTLOOK... SUN...MAINLY VFR. SUB-VFR WITH CHC LIGHT SNOW MID TO LATE AFTN. SUN NIGHT...MAINLY VFR. SUB-VFR WITH A LIGHT SNOW. AT KPSF SNOW LIKELY AFTER MIDNIGHT. MON-TUE...VFR. NO SIG WX. TUE NIGHT. MAINLY VFR. CHC -SHSN MAINLY AFTER MIDNIGHT. WED...MAINLY VFR. CHC -SHSN IN THE AM AND SLIGHT CHC IN THE AFTN. && .HYDROLOGY... THE NEXT 5 DAYS EXTENDING INTO THE MIDDLE OF NEXT WEEK WILL FEATURE NO HYDRO PROBLEMS. COLD TEMPS AND LIGHT PCPN SYSTEMS /SNOW AS THE PTYPE/ WILL ALLOW RIVERS AND STREAM TO CONTINUE TO RECEDE FROM LAST WEEKS STORM SYSTEM. THE BELOW NORMAL TEMPERATURES WILL ALLOW ICE TO REFORM AND THICKEN ON BODIES OF WATER IN THE ALBANY HYDRO SERVICE AREA. FOR SPECIFIC RIVER AND LAKE FORECASTS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...WASULA NEAR TERM...WASULA SHORT TERM...WASULA LONG TERM...IAA AVIATION...IAA HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
111 AM EST SAT FEB 2 2013 .SYNOPSIS... AS A COLD CANADIAN AIR MASS CONTINUES TO MOVE INTO THE REGION TODAY...IT WILL BE COLD AND WINDY. SOME LAKE EFFECT SNOW WILL AFFECT PORTIONS OF THE MOHAWK AND SCHOHARIE VALLEYS AND CAPITAL REGION THIS MORNING. THE WIND AND SNOW SHOWERS WILL DIMINISH TONIGHT. IT WILL REMAIN COLD THROUGH THE WEEKEND AND THERE IS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY ON SUNDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1245 AM EST...THE LATEST RUC40 SHOWS A H500 VORT MAX MOVING ACROSS THE REGION. THE LAKE EFFECT BAND AND SNOW SHOWERS HAVE DECREASED DRAMATICALLY OVER THE PAST FEW HOURS. A NARROW FILAMENT CONTINUES OVER THE NRN CATSKILLS IN SCHOHARIE COUNTY...AND THE HELDERBERGS IN WRN ALBANY COUNTY. A QUICK COATING TO UP TO AN INCH IS POSSIBLE BEFORE THE BAND FALLS APART WITH THE FLOW CONTINUING TO VEER TO THE NORTHWEST. THE LATEST HRRR SHOWS THE DISSIPATION OF THE BAND BTWN 06Z-08Z. THE FLOW WILL BEGIN TO BACK TO THE W/SW TOWARDS SUNRISE...AS THE NEXT CLIPPER APPROACHES. SOME ISOLD-SCT FLURRIES AND SNOW SHOWERS MAY IMPACT THE WRN DACKS/WRN MOHAWK VALLEY. THE TEMPS LOOK ON TRACK...WITH SLIGHT DEVIATIONS UPWARD BASED ON THE LINGERING CLOUDS. OVERNIGHT LOWS WILL BE 10-15 DEGREES ALBANY SOUTHWARD..BUT 0-10 TO THE NORTH AND WEST OF TOWN. SOME OF THE COLDEST SPOTS IN THE ADIRONDACKS WILL DIP A LITTLE BELOW ZERO. WINDS CHILLS WILL MAKE IT FEEL A BIT COLDER THAN AT TIMES...BUT NOT LOW ENOUGH TO ISSUE ADVISORIES. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... A WEAK SHORTWAVE WILL PASS TO THE NORTH OF THE REGION ON SATURDAY INTO SATURDAY NIGHT. THIS MAY ALLOW FOR SOME LIGHT SNOW SHOWERS ACROSS THE ADIRONDACKS. BY LATE IN THE DAY A WAVE MOVING FROM THE THE OHIO VALLEY TO THE MID ATLANTIC STATES MAY BRING A CHANCE FOR LIGHT SNOW TO THE SOUTHERN PART OF THE FORECAST AREA...GENERALLY SOUTH OF ALBANY. AS THE WAVE MOVES OFFSHORE SATURDAY NIGHT AND SUNDAY...IT WILL INDUCE SURFACE LOW DEVELOPMENT...SO THERE WILL BE A BETTER CHANCE FOR SOME LIGHT SNOW ACROSS THE REGION LATE SATURDAY NIGHT INTO SUNDAY...ESPECIALLY SOUTH OF ALBANY. IT WILL REMAIN COLD. HIGHS SATURDAY WILL BE IN THE MID TEENS TO THE 20S. LOWS SATURDAY NIGHT GENERALLY IN THE SINGLE NUMBERS AND TEENS...AND HIGHS SUNDAY IN THE 20S TO LOWER 30S. && .LONG TERM /MONDAY THROUGH FRIDAY/... THE MODELS ARE IN PRETTY GOOD AGREEMENT FOR THE EXTENDED PERIOD. A LARGE BROAD TROUGH WILL CONTINUE MUCH OF THE PERIOD. A SERIES OF CLIPPERS WILL CONTINUE TO PARADE THROUGH THE TROUGH BRINGING THE THREAT OF NUISANCE SNOW SHOWERS...AND PERHAPS MORE SIGNIFICANT LAKE EFFECT SNOWS. TEMPERATURES WILL CONTINUE TO TREND BELOW NORMAL. MONDAY ONE LOW PRESSURE WILL BE DEPARTING WELL TO OUR EAST...BRINGING ANOTHER SURGE OF MODIFIED ARCTIC AIR ALONG WITH THE USUAL THREAT OF SNOW SHOWERS OFF LAKE ONTARIO THAT WILL PROBABLY AT LEAST BRUSHING OUR NORTHWESTERN ZONES AND SOME UPSLOPE SNOW POSSIBLE ACROSS THE SOUTHERN GREENS. THE REMAINDER OF THE REGION WILL SEE MAINLY FLURRIES (SLIGHT CHANCE OF SNOW SHOWERS) OR REMAIN DRY WITH PARTIAL SUNSHINE. HOWEVER IT WILL BE A BRISK DAY ADDING TO THE CHILL. HIGH PRESSURE LOOKS TO BUILD IN BY TUESDAY...FOLLOWED BY ANOTHER CLIPPER ON TUESDAY NIGHT INTO WEDNESDAY. THIS STORM LOOKS TO TRACK SOUTH OF OUR REGION...MAYBE TOO FAR SOUTH TO GET INTO THE BEST SNOW SHIELD. FOR NOW...WENT WITH 30 POPS TUESDAY NIGHT LOWERING THEM TO SLIGHT CHANCES ON WEDNESDAY. ANOTHER HIGH PRESSURE WILL BUILD IN WEDNESDAY NIGHT THROUGH THURSDAY. THEN ANOTHER CLIPPER TYPE SYSTEM APPROACHES THURSDAY NIGHT INTO FRIDAY. THE EUROPEAN MODEL SUGGESTED THIS ONE COULD BE A BIT STRONGER...AND OFFER MORE IN THE WAY OF QPF. IT WOULD BE COLD FOR ALL SNOW FROM ALBANY NORTH. FURTHER SOUTH...IT MIGHT BE WARM UP RIGHT NEAR THE SURFACE TO MIX WITH SOME RAIN. THE 12Z GFS WAS NOT A ROBUST WITH THE STORM...FURTHER NORTH AND LIGHTER QPF. FOR NOW...WENT WITH A 40 POP BUT DECIDED TO CALL IT SNOW (AS OPPOSED TO SNOW SHOWERS). TEMPERATURES GENERALLY LOOK TO STARTED OUT QUITE COLD ON MONDAY AND TUESDAY...LOWER TO MID 20S FOR HIGHS CAPITAL DISTRICT AND POINTS SOUTH...TEENS NORTH...WEST AND EVEN EAST OF THE CAPITAL DISTRICT. HIGHS WILL MODERATE A LITTLE AFTER THAT. BY FRIDAY...HIGHS WILL REACH THE 30S ALBANY SOUTHWARD...25-30 REMAINDER OF THE REGION. OVERNIGHT LOWS WILL BE TEENS FROM SOUTH...SINGLE NUMBERS NORTH...WITH SELECT SPOTS ESPECIALLY IN THE ADIRONDACKS FROM ZERO TO 10 BELOW. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... HIGHER PRESSURE BRIEFLY BUILDS INTO THE REGION FROM THE SOUTHWEST THIS MORNING AND THE LAKE EFFECT SNOW WILL DISSIPATE. A CLIPPER LOW WILL APPROACH FROM THE GREAT LAKES REGION TODAY AND IS EXPECTED TO WEAKEN AS IT MOVES OVER THE REGION TONIGHT. EXPECTING VFR CONDITIONS...THE EXCEPTION WILL BE MVFR CONDITIONS AT KPSF FOR A COUPLE HOURS AT THE BEGINNING OF THE TAF TIME AND POSSIBLY AGAIN LATE IN THE EVENING. GUSTY WEST TO NORTHWEST WINDS AT KALB AND KPSF WILL WEAKEN EARLY THIS MORNING. THE FLOW WILL SHIFT TO SOUTHWEST TO SOUTH DURING THE DAY AHEAD OF THE APPROACHING CLIPPER LOW. OUTLOOK... SUN...MAINLY VFR. SUB-VFR WITH CHC SNOW DURING THE AFTN AND EVNG. MON...MAINLY VFR. SLIGHT CHC -SHSN. TUE...VFR. NO SIG WX. TUE NIGHT. MAINLY VFR. CHC -SHSN. WED...MAINLY VFR. SLIGHT CHC -SHSN. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED DURING THE NEXT FIVE DAYS. TEMPERATURES WILL BE WELL BELOW FREEZING MOST OF THE TIME DURING THE NEXT FIVE DAYS AND ONLY SNOWFALL IS EXPECTED IN TERMS OF ANY PRECIPITATION. WITH THE COLD TEMPERATURES RUNOFF HAS DECREASED SIGNIFICANTLY AND AREA STREAMS AND RIVERS ARE SLOWLY RECEDING. FOR SPECIFIC RIVER AND LAKE FORECASTS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...HWJIV/BGM/WASULA SHORT TERM...HWJIV/BGM LONG TERM...HWJIV AVIATION...IAA HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1253 AM EST SAT FEB 2 2013 .SYNOPSIS... AS A COLD CANADIAN AIR MASS CONTINUES TO MOVE INTO THE REGION TODAY...IT WILL BE COLD AND WINDY. SOME LAKE EFFECT SNOW WILL AFFECT PORTIONS OF THE MOHAWK AND SCHOHARIE VALLEYS AND CAPITAL REGION THIS MORNING. THE WIND AND SNOW SHOWERS WILL DIMINISH TONIGHT. IT WILL REMAIN COLD THROUGH THE WEEKEND AND THERE IS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY ON SUNDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1245 AM EST...THE LATEST RUC40 SHOWS A H500 VORT MAX MOVING ACROSS THE REGION. THE LAKE EFFECT BAND AND SNOW SHOWERS HAVE DECREASED DRAMATICALLY OVER THE PAST FEW HOURS. A NARROW FILAMENT CONTINUES OVER THE NRN CATSKILLS IN SCHOHARIE COUNTY...AND THE HELDERBERGS IN WRN ALBANY COUNTY. A QUICK COATING TO UP TO AN INCH IS POSSIBLE BEFORE THE BAND FALLS APART WITH THE FLOW CONTINUING TO VEER TO THE NORTHWEST. THE LATEST HRRR SHOWS THE DISSIPATION OF THE BAND BTWN 06Z-08Z. THE FLOW WILL BEGIN TO BACK TO THE W/SW TOWARDS SUNRISE...AS THE NEXT CLIPPER APPROACHES. SOME ISOLD-SCT FLURRIES AND SNOW SHOWERS MAY IMPACT THE WRN DACKS/WRN MOHAWK VALLEY. THE TEMPS LOOK ON TRACK...WITH SLIGHT DEVIATIONS UPWARD BASED ON THE LINGERING CLOUDS. OVERNIGHT LOWS WILL BE 10-15 DEGREES ALBANY SOUTHWARD..BUT 0-10 TO THE NORTH AND WEST OF TOWN. SOME OF THE COLDEST SPOTS IN THE ADIRONDACKS WILL DIP A LITTLE BELOW ZERO. WINDS CHILLS WILL MAKE IT FEEL A BIT COLDER THAN AT TIMES...BUT NOT LOW ENOUGH TO ISSUE ADVISORIES. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... A WEAK SHORTWAVE WILL PASS TO THE NORTH OF THE REGION ON SATURDAY INTO SATURDAY NIGHT. THIS MAY ALLOW FOR SOME LIGHT SNOW SHOWERS ACROSS THE ADIRONDACKS. BY LATE IN THE DAY A WAVE MOVING FROM THE THE OHIO VALLEY TO THE MID ATLANTIC STATES MAY BRING A CHANCE FOR LIGHT SNOW TO THE SOUTHERN PART OF THE FORECAST AREA...GENERALLY SOUTH OF ALBANY. AS THE WAVE MOVES OFFSHORE SATURDAY NIGHT AND SUNDAY...IT WILL INDUCE SURFACE LOW DEVELOPMENT...SO THERE WILL BE A BETTER CHANCE FOR SOME LIGHT SNOW ACROSS THE REGION LATE SATURDAY NIGHT INTO SUNDAY...ESPECIALLY SOUTH OF ALBANY. IT WILL REMAIN COLD. HIGHS SATURDAY WILL BE IN THE MID TEENS TO THE 20S. LOWS SATURDAY NIGHT GENERALLY IN THE SINGLE NUMBERS AND TEENS...AND HIGHS SUNDAY IN THE 20S TO LOWER 30S. && .LONG TERM /MONDAY THROUGH FRIDAY/... THE MODELS ARE IN PRETTY GOOD AGREEMENT FOR THE EXTENDED PERIOD. A LARGE BROAD TROUGH WILL CONTINUE MUCH OF THE PERIOD. A SERIES OF CLIPPERS WILL CONTINUE TO PARADE THROUGH THE TROUGH BRINGING THE THREAT OF NUISANCE SNOW SHOWERS...AND PERHAPS MORE SIGNIFICANT LAKE EFFECT SNOWS. TEMPERATURES WILL CONTINUE TO TREND BELOW NORMAL. MONDAY ONE LOW PRESSURE WILL BE DEPARTING WELL TO OUR EAST...BRINGING ANOTHER SURGE OF MODIFIED ARCTIC AIR ALONG WITH THE USUAL THREAT OF SNOW SHOWERS OFF LAKE ONTARIO THAT WILL PROBABLY AT LEAST BRUSHING OUR NORTHWESTERN ZONES AND SOME UPSLOPE SNOW POSSIBLE ACROSS THE SOUTHERN GREENS. THE REMAINDER OF THE REGION WILL SEE MAINLY FLURRIES (SLIGHT CHANCE OF SNOW SHOWERS) OR REMAIN DRY WITH PARTIAL SUNSHINE. HOWEVER IT WILL BE A BRISK DAY ADDING TO THE CHILL. HIGH PRESSURE LOOKS TO BUILD IN BY TUESDAY...FOLLOWED BY ANOTHER CLIPPER ON TUESDAY NIGHT INTO WEDNESDAY. THIS STORM LOOKS TO TRACK SOUTH OF OUR REGION...MAYBE TOO FAR SOUTH TO GET INTO THE BEST SNOW SHIELD. FOR NOW...WENT WITH 30 POPS TUESDAY NIGHT LOWERING THEM TO SLIGHT CHANCES ON WEDNESDAY. ANOTHER HIGH PRESSURE WILL BUILD IN WEDNESDAY NIGHT THROUGH THURSDAY. THEN ANOTHER CLIPPER TYPE SYSTEM APPROACHES THURSDAY NIGHT INTO FRIDAY. THE EUROPEAN MODEL SUGGESTED THIS ONE COULD BE A BIT STRONGER...AND OFFER MORE IN THE WAY OF QPF. IT WOULD BE COLD FOR ALL SNOW FROM ALBANY NORTH. FURTHER SOUTH...IT MIGHT BE WARM UP RIGHT NEAR THE SURFACE TO MIX WITH SOME RAIN. THE 12Z GFS WAS NOT A ROBUST WITH THE STORM...FURTHER NORTH AND LIGHTER QPF. FOR NOW...WENT WITH A 40 POP BUT DECIDED TO CALL IT SNOW (AS OPPOSED TO SNOW SHOWERS). TEMPERATURES GENERALLY LOOK TO STARTED OUT QUITE COLD ON MONDAY AND TUESDAY...LOWER TO MID 20S FOR HIGHS CAPITAL DISTRICT AND POINTS SOUTH...TEENS NORTH...WEST AND EVEN EAST OF THE CAPITAL DISTRICT. HIGHS WILL MODERATE A LITTLE AFTER THAT. BY FRIDAY...HIGHS WILL REACH THE 30S ALBANY SOUTHWARD...25-30 REMAINDER OF THE REGION. OVERNIGHT LOWS WILL BE TEENS FROM SOUTH...SINGLE NUMBERS NORTH...WITH SELECT SPOTS ESPECIALLY IN THE ADIRONDACKS FROM ZERO TO 10 BELOW. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... MAINLY VFR CONDITIONS WILL PREVAIL THROUGHOUT SATURDAY. SNOW SHOWERS HAVE FLARED UP ONCE MORE DOWN THE MOHAWK VALLEY. THREW IN A FOUR HOUR TEMPO TO INCLUDE AT LEAST A 50 PERCENT CERTAINTY THAT MVFR SNOW SHOWERS COULD TAKE PLACE UP TO HALF OF THE TIME IN THAT TIME FRAME. WILL CONTINUE TO MONITOR TRENDS. HAVE CONTINUED THE TEMPO FOR TEMPO SNOW SHOWERS AT KPSF AS WELL. OTHERWISE VFR CONDITIONS WILL PREVAIL. NO SNOW SHOWERS EXPECTED AT THE OTHER SITES. THE SKY WILL REMAIN PARTLY CLOUDY (PROBABLY FREE OF CIGS). EVEN IF ANY DO BRIEFLY OCCUR...THEY WOULD BE IN THE MVFR RANGE. THE GUSTY W TO NW WIND (ESPECIALLY AT KALB) WILL DIMINISH WITH TIME TO AROUND 5-10KTS. (KEPT TEMPS FOR GUSTY WINDS AROUND 20KTS AT ALL TAF SITES AWHILE THIS EVENING LONGEST AT KALB AND KPSF). SATURDAY LOOKS MAINLY DRY TO START...BUT THERE IS A SLIGHT INCREASING THREAT IN MORE SNOW SHOWER ACTIVITY LATER IN THE DAY AS A CLIPPER NEARS WITH ITS ASSOCIATED COLD FRONT. THE SOUTH WIND WILL PICK UP TO NEAR 10KTS MIDDAY (WITH A FEW HIGHER GUSTS POSSIBLE AT KALB). WE ASSIGNED A VCSH DURING THE AFTERNOON AT ALL TAF SITES TO INDICATE THE POSSIBILITY OF SNOW SHOWERS AROUND...A FEW WHICH COULD BRIEFLY DROP CONDITIONS TO MVFR BUT RIGHT CONFIDENCE WAS BELOW 30 PERCENT. OUTLOOK... SAT NIGHT..VFR. NO SIG WX. SUN-SUN NIGHT. MAINLY VFR. CHC SUB-VFR -SHSN. MON-TUE. VFR. NO SIG WX. TUE NIGHT-WED. MAINLY VFR. CHC SUB-VFR -SHSN. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED DURING THE NEXT FIVE DAYS. TEMPERATURES WILL BE WELL BELOW FREEZING MOST OF THE TIME DURING THE NEXT FIVE DAYS AND ONLY SNOWFALL IS EXPECTED IN TERMS OF ANY PRECIPITATION. WITH THE COLD TEMPERATURES RUNOFF HAS DECREASED SIGNIFICANTLY AND AREA STREAMS AND RIVERS ARE SLOWLY RECEDING. FOR SPECIFIC RIVER AND LAKE FORECASTS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...HWJIV/BGM/WASULA SHORT TERM...HWJIV/BGM LONG TERM...HWJIV AVIATION...HWJIV HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1120 PM CST FRI FEB 1 2013 .AVIATION...06Z TAF. SATELLITE AND OBSERVATIONS SHOW SOME LOWER CLOUDS THAT WILL AFFECT THE KGRI TERMINAL AREA. THESE SHOULD BE VFR AND SHOULD DIMINISH AFTER DAY BREAK. A SURFACE TROUGH THAT IS MOVING THROUGH THE AREA AT THIS TIME HAS TURNED WINDS TO THE NORTHWEST. THEY WILL INCREASE A BIT AROUND SUNRISE...THEN BECOME GUSTY AND INCREASE THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 656 PM CST FRI FEB 1 2013/ UPDATE...EVENING UPPER AIR ANALYSIS INDICATES LONGWAVE TROUGHING OVER THE EASTERN TWO-THIRDS OF THE CONUS...WITH RIDGING BUILDING INTO THE WEST. MID AND UPPER LEVEL FLOW REMAINS FROM THE NORTHWEST ACROSS THE CENTRAL PLAINS...MAXING OUT AT AROUND 70KTS NEAR 200MB OVER OUR AREA. WATER VAPOR IMAGERY INDICATES A SUBTLE MID LEVEL SHORT WAVE EXTENDING FROM THE DAKOTAS...SOUTHWEST INTO WESTERN NEBRASKA AND SOUTHEASTERN WYOMING. AT THE SURFACE A WEAK AREA OF BAROMETRIC PRESSURE EXISTS OVER EASTERN SOUTH DAKOTA...WITH A TROUGH EXTENDING SOUTHWEST FROM THE LOW ACROSS PORTIONS OF NEBRASKA AND KANSAS. THIS TROUGH PRETTY MUCH BISECTS OUR CWA...WITH THE LOW LEVEL WIND FIELD ACROSS THE SOUTHEASTERN HALF OF OUR CWA REMAINING FROM THE SOUTHWEST...AND LOCATIONS FARTHER NORTHWEST NOW OBSERVING A SURFACE WIND FROM THE NORTHWEST. RADAR DATA FROM KUEX...KLNX...AND KGLD ALL INDICATE LIGHT ELEVATED PRECIPITATION EXTENDING FROM PORTIONS OF WESTERN NEBRASKA INTO NORTHWESTERN KANSAS AND NORTHEASTERN COLORADO. REPORTS OF PRECIPITATION ACTUALLY BEING REALIZED AT THE SURFACE HAVE BEEN FEW AND FAR IN BETWEEN HOWEVER...WITH PROXIMITY SOUNDINGS FROM LAPS AND RAP ANALYSIS INDICATING A VERY DRY LOWER TROPOSPHERE IS LIKELY PREVENTING MUCH OF ANY PRECIPITATION FROM MAKING IT TO THE SURFACE. GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...SREF-MEAN...AND RAP ALL SUGGEST THE MID LEVEL SHORT WAVE...CURRENTLY OVER THE NORTHERN AND CENTRAL PLAINS...WILL CONTINUE MOVING SOUTHEAST TONIGHT...WITH THE MID LEVEL TROUGH AXIS EXPECTED TO CLEAR OUR CWA SHORTLY AFTER 06Z. VERY WEAK MID LEVEL THERMAL ADVECTION AHEAD OF THE TROUGH AXIS IS CREATING JUST ENOUGH OMEGA FOR THE ELEVATED PRECIPITATION CURRENTLY BEING INDICATED BY AREA RADARS...WITH THIS AXIS OF WEAK OMEGA EXPECTED TO CONTINUE PUSHING ACROSS OUR AREA TONIGHT AS THE MID LEVEL TROUGH AXIS DOES THE SAME. THE BACK EDGE OF THIS OMEGA AXIS IS APPARENTLY ALREADY WORKING INTO NORTHERN AND WESTERN NEBRASKA...WITH KLNX INDICATING THE BACK EDGE ELEVATED PRECIPITATION EXTENDING FROM NEAR KANW TO NEAR KIBM. GIVEN THE CURRENT MOVEMENT OF THE MID LEVEL SHORT WAVE ON WATER VAPOR IMAGERY...AND RADAR TRENDS THROUGH THE PAST 2-3 HOURS...IT APPEARS THE BEST CHANCE FOR PRECIPITATION OVER OUR AREA WILL OCCUR BETWEEN NOW AND 06Z...WITH DRY CONDITIONS LIKELY THEREAFTER AS THE MID LEVEL TROUGH AXIS CLEARS THE AREA AND SUBSIDENCE SETTLES IN. DESPITE THE RETURNS AS INDICATED BY AREA RADARS...ITS HARD TO IGNORE THE VERY DRY LOWER TROPOSPHERE CURRENTLY IN PLACE AND THUS IS SEEMS UNLIKELY MEASURABLE PRECIPITATION WILL BE REALIZED ACROSS ANY OF OUR CWA TONIGHT. GIVEN THIS...WENT AHEAD AND PULLED POPS FROM THE FORECAST FOR TONIGHT. THAT BEING SAID...CANNOT COMPLETELY RULE OUT AN OCCASIONAL SPRINKLE MAKING IT TO THE SURFACE THROUGH THE NEXT FEW HOURS AS THERE HAVE BEEN A FEW OBSERVATIONS ACROSS WESTERN NEBRASKA WHICH INDICATED A BRIEF PERIOD OF PRECIPITATION HERE OR THERE. GIVEN THE AFOREMENTIONED RADAR RETURNS AND OBSERVATIONS...OPTED TO GO WITH A MENTION OF SPRINKLES ACROSS OR SOUTHWESTERN CWA THROUGH THIS EVENING AS THE MOST ENHANCED AREA OF RADAR RETURNS...AROUND 25DBZ...PUSH OVER THOSE AREAS. PROXIMITY SOUNDINGS FROM ACROSS OUR CWA PER LAPS AND RAP ANALYSIS INDICATE AN ELEVATED WARM LAYER DOES EXIST NEAR 850MB...WITH FORECAST PROXIMITY SOUNDINGS PER THE NAM...OPERATIONAL GFS...AND RAP SUGGESTING THIS ELEVATED WARM LAYER WILL REMAIN INTACT THROUGH MUCH OF THE NIGHT. IF MORE SIGNIFICANT PRECIPITATION WERE EXPECTED TO MAKE IT TO THE SURFACE...THIS WOULD CERTAINLY CREATE CONCERNS WITH RESPECT TO FREEZING RAIN. THAT BEING SAID...BECAUSE THE RADAR RETURNS THUS FAR THIS EVENING HAVE BEEN SO WEAK...AND BECAUSE THE MAJORITY GUIDANCE SUGGESTS NO PRECIPITATION WILL BE REALIZED OVER OUR AREA TONIGHT...AND BECAUSE THERE IS SUCH A DEEP LAYER OF LOWER TROPOSPHERIC DRY AIR IN PLACE...AM NOT OVERLY CONCERNED WITH AN ICING THREAT AT THIS TIME. SHOULD SPRINKLES BE REALIZED ACROSS PORTIONS OF THE CWA AFTER 02Z TONIGHT...THEN TECHNICALLY THESE WOULD BE FREEZING SPRINKLES AS SURFACE TEMPERATURES WILL HAVE DROPPED BELOW FREEZING BY THEN. BUT AT THIS TIME THE THREAT OF ICING FROM SUCH ACTIVITY IS LITTLE TO NONE AND GIVEN THIS...OPTED TO PULL ANY MENTION OF FREEING RAIN FROM THE HWO. REMAINDER OF THE FORECAST REMAINS IN GOOD SHAPE...WITH ONLY SOME MINOR TWEAKS MADE TO HOURLY TEMPERATURE...SKY...WIND...AND DEWPOINT GRIDS TO ACCOUNT FOR CURRENT OBSERVATIONS. PREV DISCUSSION... /ISSUED 324 PM CST FRI FEB 1 2013/ A TROF EMBEDDED IN NW FLOW MAY DELIVER A LIGHT WINTRY MIX IN SPOTS TNGT THEN WE DEAL WITH WINDY CONDITIONS N OF I-80 SAT... SHORT TERM...TONIGHT AND SATURDAY UPPER-LEVELS: A +PNA PATTERN WAS IN PLACE...WITH A WRN N AMERICA RIDGE AND AN ERN TROF. A PAIR OF PV ANOMALIES WERE DIVING DOWN THE BACK SIDE OF THE LGWV TROF. THE 1ST WAS OVER WY AT MID AFTN WITH THE 2ND OVER ALBERTA HEADING FOR MT. THE FIRST SHRTWV TROF WILL SLIDE INTO AND THRU KS TNGT. THE SECOND WILL FOLLOW IT INTO NEB AFTER MIDNGT. A SHRTWV RIDGE FOLLOWS SAT MRNG...WITH A THIRD PV ANOMALY MISSING AND HEADING INTO IA...AS THE LGWV PATTERN PROGRESSES A BIT AND HGTS RISE. STRONG MO HIGH PRES WILL DEPART TO THE MID-ATLC STATES TNGT. THE ARCTIC FRONT BISECTED NEB-KS. THIS FRONT AND ITS THERMAL RIBBON WERE BEING SHOVED E BY SW FLOW AHEAD OF A VERY WEAK SFC LOW. THIS LOW TRACKS JUST N OF THE FCST AREA...TO THE MS RIVER BY DAYBREAK SAT. HIGH PRES FOLLOWS HERE TOMORROW. TNGT: VARIABLE CLOUDS BUT OVERALL EXPECT SKIES TO AVERAGE M/CLOUDY. EXPANDED THREAT OF VERY LIGHT PCPN TO THE ENTIRE FCST AREA AND WE NOW HAVE CHANCE POPS FOR AREAS NE OF THE TRI-CITIES AND FROM HWY 136 DOWN INTO N-CNTRL KS. ODDS ARE MOST PLACES REMAIN DRY WITH LACK OF MSTR IN THE SUB-CLOUD LAYER...BUT WAS NOT COMFORTABLE WITH AN ENTIRELY DRY FCST. NEXT ISSUE IS PCPN TYPE. BOTH DDC/LBF HAD A WARM NOSE IN 12Z SOUNDINGS. NAM/GFS BUFKIT SOUNDINGS SUGGEST 850 MB HAS WARMED TO +3C OVERHEAD THIS AFTN. SO "IF" PCPN FALLS TNGT...PLAYED IT AS FLURRIES OR A BRIEF SNOW SHWR NE OF THE TRI-CITIES...FLURRIES OR SPRINKLES IN THE TRI-CITIES...AND SPRINKLES AND POSSIBLY A RAIN SHWR S OF HWY 6 INTO N-CNTRL KS. THAT SAID...BELOIT IS STILL SUB- FRZG AND THE REST OF N-CNTRL KS NOT MUCH ABOVE FRZG. IF TEMPS COOL BACK DOWN BELOW FRZG AND A FEW -SHRA OCCUR...THERE COULD BE A TOUCH OF GLAZE. THE LOW PROBABILITY THREAT IS NOW OUTLOOKED IN THE HWO. BEST CHANCE OF PCPN WILL OCCUR 9PM-3AM. USED BURST OF PW AND K-INDEX TO ASSIST IN TIMING/LOCATION OF POPS THRU THE FCST AREA. CHANCE POPS S OF HWY 136 WERE BASED ON HI-RES MODEL REFLECTIVITY WHICH IS SUPPORTED BY THE TRACK OF THE PV ANOMALY. TEMPS: VARIABLE CLOUD COVER LOWERS CONFIDENCE SOMEWHAT...BUT OVERALL THINK IT WILL BE A MILD NGT. TEMPS ARE BIAS CORRECTED BLEND OF 2M TEMPS AND THE PREVIOUS GID FCST /21-27F/. SAT: SKIES SHOULD BE P/CLOUDY S AND W OF THE TRI-CITIES AT DAWN... AND M/CLOUDY N AND E. CLEARING AS THE DAY PROGRESSES AND WINDY N OF I-80 IN THE "WARM" SECTOR OF THE NEXT PV ANOMALY AND CLIPPER FCST OVER IA. WIND: THERE IS A LOW PROBABILITY WE MAY NEED A WIND ADVISORY FOR SOME OF OUR COUNTIES N OF I-80. SUBJECTIVE PROBABILITY PUTS IT AROUND 40 PERCENT. WITH THE STRENGTH OF THE LOW-LEVEL WIND FIELDS...BUFKIT MIXING HGTS ARE UNNERVING FROM BOTH THE NAM/GFS. FOR NOW WE/VE INCLUDED G40 MPH IN THE FCST. THE MAIN CORE OF THE STRONGEST WIND MOVES IN AFTER 21Z. THE 15Z SREF MEAN INCREASES SPEEDS 40-45 KTS 21Z-00Z. THIS COINCIDES WITH PEAK HEATING AND WILL NEED TO BE CONSIDERED BY THE MID SHIFT. TEMPS ARE BIAS CORRECTED MOS GUIDE WITH SOME ADDITIONAL LOWERING OF TEMPS OVER THE SNOW COVER S AND E OF HASTINGS AND SOME RAISING FROM LXN DOWN TO THE KS BORDER...WHERE BIAS CORRECTION PROBABLY CUT TEMPS TOO MUCH. LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. BEGINNING SATURDAY NIGHT...A NORTHWEST FLOW PATTERN WILL BE IN PLACE ACROSS THE CENTRAL PLAINS AND SHORTWAVE ENERGY IS PROGGED TO TRANSLATE SOUTHEAST ALONG THE MISSOURI RIVER. COLD AIR BACKS IN BRIEFLY FOR THE OVERNIGHT TIME FRAME...THEN IN RETURN FLOW ON SUNDAY THE AIRMASS MODERATES BEHIND THE DEPARTING WAVE. THE NORTHWEST FLOW PATTERN REMAINS PROGRESSIVE THROUGH MID WEEK WEEK WITH A SERIES OF WAVES TRANSLATING THRU FLOW...MAINLY ALONG AND EAST OF THE MISSOURI RIVER...WHICH WILL BRING A FEW COLD FRONTS ACROSS THE PLAINS WITH THE BRUNT OF THE COOLER AIR REMAINING TO OUR EAST. IN THIS REGIME WE WILL SEE ALTERNATING PERIODS OF WAA/CAA BUT WITH CONDITIONS REMAINING DRY. AROUND MID WEEK...THE RIDGING OVER THE ROCKIES BREAKS DOWN AND SETTLES ONTO THE PLAINS ALLOWING FOR A PROGRESSIVE BUT MORE ZONAL FLOW PATTERN. EXTENDED MODELS ARE FAIRLY CONSISTENT WITH YET ANOTHER SHORTWAVE TROUGH TO CROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY NIGHT...AND MODELS ARE HINTING THAT FRONT MAY BECOME ACTIVE WEDNESDAY NIGHT NEAR OUR SOUTHEAST ZONES. CONFIDENCE IN PCPN THIS FAR OUT IS NOT HIGH AND WILL CONTINUE TO MONITOR. ONCE THIS WAVE DEPARTS...AN UPPER RIDGE SETTLES ACROSS THE INTERIOR CONUS WHILE AN UPSTREAM TROUGH MOVES INTO THE ROCKIES. THE WEATHER PATTERN LOOKS TO BECOME MORE ACTIVE NEXT WEEKEND WITH THE PROGRESSION OF THE WESTERN TROUGH AND THIS WILL BE SOMETHING TO KEEP AN EYE ON. UNTIL THAT TIME FRAME HOWEVER...LOOK FOR MAINLY DRY CONDITIONS WITH TEMPS ABOVE NORMAL FOR THE MOST PART...ESPECIALLY AFTER THE SNOW MELTS IN OUR EASTERN ZONES. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
400 AM CST SAT FEB 2 2013 .SHORT TERM...TODAY THROUGH MONDAY NIGHT MAIN FORECAST CHALLENGES INCLUDE LIGHT SNOW CHANCES AND TEMPERATURES. GFS/NAM/ECMWF/GEM IN GOOD AGREEMENT AND WILL USE A BLENDED SOLUTION FOR THIS FORECAST PACKAGE. FOR TODAY...A CLIPPER SYSTEM IN NORTHWEST FLOW ALOFT WILL MOVE ACROSS THE NORTHERN PLAINS. MOST OF THE FORECAST AREA WILL REMAIN ON THE COOL SIDE OF THE SYSTEM AS THE SURFACE LOW TRACKS FROM CENTRAL SASKATCHEWAN TO NORTHEAST SD. AFTERNOON HIGHS WILL MAINLY BE IN THE SINGLE DIGITS TO LOW TEENS ABOVE ZERO...BUT AREAS WEST OF A LINE FROM DEVILS LAKE TO VALLEY CITY TO LISBON MAY CLIMB INTO THE LOW 20S. CANADIAN RADARS SHOW LIGHT SNOW SOUTH AND EAST OF THE SURFACE LOW AND THIS BAND IS EXPECTED TO MOVE SOUTHEASTWARD THROUGH THE DAY...MAINLY IMPACTING EASTERN ND INTO WEST CENTRAL MN. SLOWED THE TIMING OF THE HIGHEST POPS AS LATEST RAP OUTPUT KEEPS MAJORITY OF PRECIPITATION OUT OF THE FORECAST AREA UNTIL AFTER 15 UTC. TOTAL ACCUMULATIONS THROUGH TONIGHT WILL GENERALLY BE AN INCH OR LESS. REMAINING SNOW SHOWERS EXPECTED TO MOVE EAST OF THE FORECAST AREA BY MIDNIGHT WITH DECREASING CLOUD COVER FROM WEST TO EAST. SUNDAY MORNING LOWS EXPECTED IN THE 0 TO 10 BELOW RANGE...BUT WILL BE HIGHLY DEPENDENT ON CLOUD COVER. ANOTHER WEAK CLIPPER DROPS SOUTH ON SUNDAY...BRINGING A NARROW BAND OF LIGHT SNOW FROM CENTRAL ND INTO SOUTHWEST MN. STRONG SURFACE HIGH WILL MOVE INTO THE NORTHERN VALLEY BY 06 UTC MONDAY AND THIS WILL LIMIT NORTHWARD EXTENT OF PRECIPITATION. MODEL TRENDS PLACE SNOW FARTHER SOUTH...SO ADJUSTED HIGHEST POPS SOUTH OF A LINE FROM DEVILS LAKE TO HILLSBORO TO PARK RAPIDS. ACCUMULATIONS EXPECTED TO BE EVEN LESS THAN TODAY...GENERALLY A HALF INCH OF LESS. SKIES WILL BE MOSTLY CLOUDY AND TEMPERATURES WILL BE NEAR OR SLIGHTLY COOLER THAN TODAY IN THE WAKE OF TODAY/S SYSTEM. THE PARADE OF CLIPPERS CONTINUE INTO EARLY NEXT WEEK WITH A THIRD WAVE ON MONDAY. THE TRACK OF THE SURFACE LOW IS A BIT FARTHER NORTH...SO EXPECT GREATER SPATIAL COVERAGE OF ACCUMULATING SNOWFALL. STRONG MID-LEVEL WARM AIR ADVECTION WILL COMBINE UPPER JET DYNAMICS TO PRODUCE A COUPLE INCHES OF SNOW ACROSS THE NORTHERN VALLEY INTO NORTHWEST MN. WITH TRACK OF THE LOW AND ALIGNMENT OF THE BAROCLINIC AXIS...TEMPERATURES WILL BE A BIT WARMER WITH AFTERNOON HIGHS MAINLY IN THE TEENS ABOVE ZERO. MORNING LOWS WILL CONTINUE TO BE DEPENDENT ON CLOUD COVER...BUT NOT EXPECTING MUCH DAY TO DAY CHANGE WITH THE COOLEST READINGS ACROSS THE LAKE OF THE WOODS REGION. .LONG TERM...TUESDAY THROUGH FRIDAY NIGHT NW FLOW ALOFT WILL SLOWLY TRANSITION TO A MORE ZONAL/SW FLOW ALOFT BY NEXT WEEKEND. THIS WILL MEAN GRADUALLY WARMING TEMPS ABOVE NORMAL WITH MINIMAL CHANCES FOR PRECIP THROUGH SAT. THERE IS THE POTENTIAL FOR SOME LINGERING LIGHT SNOW EARLY TUE IN THE EAST...AND IN THE NORTH ON WED WITH SOME WAA. OTHERWISE...EXPECT A DRY EXTENDED WITH A WARMING TREND. THERE ARE SOME HINTS AT A POTENTIAL STORM BY LATE SAT INTO SUNDAY...WITH THE MAIN POTENTIAL IMPACTS AT THIS TIME POSSIBLE IN THE SOUTHERN FORECAST AREA. && .AVIATION... VFR/MVFR CEILINGS WILL INCREASE FROM WEST TO EAST THROUGH THE DAY AS A LOW PRESSURE SYSTEM MOVES ACROSS THE REGION. SOME LIGHT SNOW IS POSSIBLE FOR AIRFIELDS ALONG AND WEST OF THE VALLEY AFTER 15 UTC. SNOW SHOULD BE LIGHT...BUT SOME REDUCTIONS IN VISIBILITY LESS THAN ONE MILE ARE POSSIBLE. LIGHT SOUTH-SOUTHWEST WIND THROUGH THE DAY WILL INCREASE AND SHIFT TO THE NORTHWEST THIS EVENING AND OVERNIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ ROGERS/DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1249 AM CST SAT FEB 2 2013 .DISCUSSION... LIGHT SNOW CONTINUES TO SLOWLY SPREAD EAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY THIS MORNING...WITH A SHARP GRADIENT ALONG THE EASTERN PERIPHERY OF THE SURFACE HIGH PRESSURE OVER THE EAST. THE DRY AIR ASSOCIATED WITH THIS SURFACE HIGH WILL CONTINUE TO LIMIT THE EASTERN EXTENT OF THE AREA OF LIGHT SNOW. HAVE OPTED TO TRIM BACK POPS/QPF ACROSS THE CENTRAL...USING THE LATEST RADAR DATA AND RAP SOLUTION AS A GUIDE. OTHERWISE...MINOR ADJUSTMENTS TO ALL OTHER GRIDS TO REFLECT CURRENT OBS AND TRENDS. && .AVIATION... LOW PRESSURE WILL DROP SOUTHEAST ACROSS ALBERTA AND SASKATCHEWAN LATE TONIGHT THEN ACROSS CENTRAL AND INTO SOUTHEAST NORTH DAKOTA ON SATURDAY. LIGHT NORTH TO NORTHWEST WINDS WILL SHIFT SOUTH TO SOUTHWEST LATE TONIGHT THEN BACK NORTHWEST ON SATURDAY BEHIND THE SURFACE LOW. WINDS WILL BECOME GUSTY BY SATURDAY AFTERNOON THEN DIMINISH BY SATURDAY EVENING. WIDESPREAD MVFR-IFR CEILINGS AND VISIBILITIES WILL REMAIN OVER WESTERN AND CENTRAL NORTH DAKOTA AHEAD OF THE APPROACHING SURFACE LOW. LOWEST VISIBILITIES IN SNOW WILL REMAIN FROM MINOT TO JAMESTOWN ON SATURDAY...CLOSE TO THE TRACK OF THE LOW. EXPECT IMPROVING CEILINGS SATURDAY EVENING FROM WEST TO EAST. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 9 AM CST /8 AM MST/ THIS MORNING TO 6 PM CST /5 PM MST/ THIS EVENING FOR NDZ001>003-009>011-017>021-031>035- 040>046. WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR NDZ004-005-012-013-022-023-025-036-037-047-048-050-051. && $$ SHORT TERM...HUBER AVIATION...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1126 PM CST FRI FEB 1 2013 .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT 345 PM CDT FRI FEB 1 2013 AT 3 PM...THE WATER VAPOR IMAGERY SHOWED A SHORT WAVE TROUGH MOVING SOUTHEAST THROUGH LAKE WINNIPEG. AT THE THE SURFACE...A COLD FRONT...LOCATED JUST SOUTH OF LAKE WINNE PEG...WAS PRODUCING SNOW ACROSS THE EASTERN DAKOTAS...AND NORTHWEST AND WEST CENTRAL MINNESOTA. THIS SNOW WAS REDUCING VISIBILITIES TO 3/4 MILES AT FARGO NORTH DAKOTA. FOR TONIGHT...THE 01.12Z MESO AND DETERMINISTIC MODELS ARE IN GOOD AGREEMENT THAT SHORT WAVE TROUGH AND COLD FRONT TO OUR NORTHWEST WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA THIS EVENING AND EARLY OVERNIGHT. MODERATE 270 TO 280K ISENTROPIC LIFT /2 TO 4 MICROBARS/SEC/ DEVELOPS AHEAD OF THIS SYSTEM. THIS IS BRINGING THE WARMER AND MORE MOIST /DEW POINTS IN THE LOWER AND MID 20S/ AIR ALOFT. THIS WARMS THE ATMOSPHERIC COLUMN INTO THE DENDRITIC GROWTH ZONE AND THE MOISTURE SATURATES IT. 01.09Z SREF SHOWS THAT 50 TO 70 PERCENT OF THE ENSEMBLE FAMILY HAS OVER 200 MB OF DENDRITIC GROWTH THIS EVENING. THE ROCHESTER RAP BUFKIT SOUNDING SHOWS AT LEAST 10K FEET IN THE DENDRITIC GROWTH ZONE BETWEEN 02.00Z AND 02.06Z. MEANWHILE THE GFS AND NAM BUFKIT SOUNDINGS HAVE A MUCH SHORTER TIME. THIS WILL AFFECT THE SNOW RATIOS. THE RAP WOULD SUGGEST 25-30 TO 1 SNOW TO LIQUID RATIOS. MEANWHILE THE GFS AND NAM WOULD SUGGEST 17-23 TO 1 SNOW TO LIQUID RATIOS. SINCE THE SYSTEM IS MOVING SO FAST...TRENDED MORE TOWARD THE GFS AND NAM SOLUTIONS. THIS WOULD PRODUCE A 1 TO 2 INCH SNOW BAND ACROSS NORTHEAST IOWA AND AND SOUTHWEST WISCONSIN...AND AROUND AN INCH NORTHWARD TO WISCONSIN 10. ON SATURDAY AFTERNOON AND NIGHT...ANOTHER SHORT WAVE TROUGH WILL MOVE SOUTHEAST THROUGH THE REGION. UNLIKE YESTERDAY...HAS THE LEFT ENTRANCE REGION OF THE 250 MB JET A BIT FURTHER SOUTHEAST. AS A RESULT...THE OMEGA IS NOT AS STRONG OR DEEP AS IT WAS YESTERDAY. DESPITE THIS THERE IS MODERATE 270 TO 280K LIFT AHEAD OF THIS WAVE AND THIS WILL ONCE AGAIN BRING SOME MOISTURE AND WARMER AIR ALOFT FROM THE NORTHERN AND CENTRAL PLAINS. HOWEVER 01.09Z SREF SHOWS FEWER MEMBERS HAVING 200 MB OR GREATER OF DENDRITIC GROWTH. THE COBB DATA SUGGESTS 17-22 TO 1 SNOW TO LIQUID RATIOS. THIS WOULD RESULT IN AROUND AN INCH OF SNOW FOR MUCH OF THE AREA. FROM LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT...THE MODELS SHOW YET ANOTHER SHORT WAVE TROUGH WILL BE MOVING SOUTHEAST THROUGH THE REGION. BY THIS TIME...THE AIR MASS WILL BE A BIT WARMER. AS A RESULT...THE BEST ISENTROPIC LIFT IS TAKING PLACE BETWEEN 280 AND 300K. WITH THE AIR MASS WARMER...THERE IS LESS OF A LAYER IN DENDRITIC GROWTH ZONE. HOWEVER THERE IS A BIT MORE MOISTURE FOR THIS SYSTEM TO WORK WITH...SO IT LOOKS LIKE SNOW TOTALS WILL RANGE FROM 1 TO 2 INCHES. OVERALL...IT LOOKS LIKE SNOW TOTALS DURING THE NEXT 3 DAYS WILL RANGE FROM 2 TO 5 INCHES. .LONG TERM...MONDAY THROUGH FRIDAY 345 PM CDT FRI FEB 1 2013 ON MONDAY NIGHT AND TUESDAY MORNING...ANOTHER SHORT WAVE WILL BE MOVING SOUTHEAST THROUGH THE REGION. LIKE THE SYSTEM ON SUNDAY AND SUNDAY NIGHT...THERE IS NOT MUCH OF THE THE ATMOSPHERIC COLUMN IN THE DENDRITIC GROWTH ZONE...BUT THERE IS MORE MOISTURE FOR THIS SYSTEM TO WORK WITH. AS A RESULT...THE SNOW TO LIQUID RATIOS LOOK TO BE 15-20 TO 1. WITH A TENTH TO 2 TENTHS OF INCH OF QPF...THERE COULD BE THE POTENTIAL OF ANOTHER 1 TO 3 INCHES OF SNOW. IT STILL LOOKS LIKE ANOTHER SYSTEM WILL AFFECT THE AREA FROM WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THE MODELS HAVE BEEN MUCH LESS CONSISTENT WITH THEIR PRECIPITATION AMOUNTS AND THE LOCATION OF THIS SYSTEMS WARM FRONT. AS A RESULT...THERE IS MUCH LESS CERTAINTY THAN THE PREVIOUS 4 SYSTEMS. && .AVIATION...THROUGH 06Z SUNDAY 1126 PM CST FRI FEB 1 2013 THE SNOW CONTINUES TO MOVE SOUTHEAST ACROSS THE REGION WITH THE LOCAL RADAR SHOWING THAT THE BULK OF IT SHOULD BE PAST BOTH TAF SITES BY 06Z. STILL SOME RETURNS SHOWING UP ON THE KMPX RADAR WITH SURFACE OBSERVATIONS SHOWING VISIBILITIES DOWN TO 3 OR 4 MILES AT TIMES. WILL SHOW THIS IN THE TAFS UNTIL THE WINDS SWING AROUND TO THE NORTH/NORTHWEST ONCE THE SURFACE LOW MOVES ACROSS NORTHERN IOWA INTO ILLINOIS. HIGH PRESSURE OVER MANITOBA WILL QUICKLY MOVE OVER THE REGION SATURDAY ALLOWING THE CLOUDS TO SCATTER OUT FOR A SHORT PERIOD BEFORE THE NEXT SYSTEM STARTS TO COME IN. THE 02.00Z NAM SUGGEST THE PV ADVECTION IN THE 500-300 MB LAYER WILL BE STRONGER WITH THIS NEXT SHORT WAVE TROUGH THAN WITH THE ONE THIS EVENING WITH UP TO 12 PVU/S POSSIBLE. THE WAVE SHOULD ALSO PRODUCE WEAK TO MODERATE QG CONVERGENCE ON THE 850-500 MB LAYER. HOWEVER...THERE SHOULD BE VERY LITTLE FRONTOGENESIS WITH JUST A WEAK SIGNAL IN THE 1000-850 MB LAYER. THE BEST ISENTROPIC UP GLIDE WILL SLIDE WEST OF THE REGION WITH ONLY 1 UBAR/S POSSIBLE ON THE 275K SURFACE. EXPECT THAT THE FORCING WITH THIS WAVE WILL BE ENOUGH TO GENERATE ANOTHER ROUND OF SNOW WITH MVFR CONDITIONS AND WILL BRING THE SNOW INTO BOTH TAF SITES AROUND 03.03Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 344 PM CST FRI FEB 1 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
929 AM EST SAT FEB 2 2013 .SYNOPSIS... A CLIPPER LOW WILL APPROACH FROM THE LOWER GREAT LAKES REGION WITH ISOLATED TO SCATTERED SNOW SHOWERS LATE THIS AFTERNOON INTO THIS EVENING. ANOTHER CLIPPER WILL IMPACT THE REGION LATE SUNDAY INTO SUNDAY NIGHT WITH SOME LIGHT SNOW AND CONTINUED BELOW NORMAL TEMPERATURES TO OPEN NEXT WEEK. MUCH OF THE UPCOMING WEEK WILL BE DRY WITH SEASONABLY CHILLY TEMPERATURES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 929 AM EST...A BAND OF LAKE EFFECT SNOW HAS DEVELOPED OFF LAKE ONTARIO...BUT IS REMAINING NORTHWEST OF OUR FORECAST AREA ACROSS THE TUG HILL PLATEAU AND INTO THE ST. LAWRENCE VALLEY. WITH A SW FLOW TRAJECTORY IN PLACE...THIS BAND SHOULD REMAIN JUST NORTHWEST OF OUR FORECAST AREA TODAY. THE 240 DEGREE TRAJECTORY IS EXPECTED TO IMPACT LOCATIONS JUST NORTH AND WEST OF THE WRN DACKS. THE LATEST 12Z ALY HIRES WRF COMPOSITE REFLECTIVITY...AND 3-KM HRRR SHOW LITTLE IMPACT IN OUR AREA TODAY. WE KEPT SOME HIGH CHC AND LIKELY POPS NORTH OF OLD FORGE IN HERKIMER COUNTY...AND FAR NW HAMILTON COUNTY...BUT THE CORE OF THE BAND SHOULD REMAIN TO THE NW. A WEAK CLIPPER LOW IS MOVING ACROSS THE OHIO VALLEY THIS MORNING AS SEEN VIA THE WATER VAPOR LOOP. THIS SYSTEM WILL APPROACH FOR THE LATE AFTN AND EARLY EVENING HOURS. THERE IS LITTLE MOISTURE FOR THIS SYSTEM TO WORK WITH...AND WITH THE SYSTEM BEING RATHER WEAK...FORCING WILL BE LIMITED. VERY DRY LOW LEVELS WILL ALLOW FOR SOME OF THE LITTLE MOISTURE THIS SYSTEM HAS TO BE LOST AS VIRGA. WE WILL GO WITH SLIGHT CHC TO CHC POPS FOR MOST OF THE AREA DURING THE AFTN/EARLY EVENING TO ACCOUNT FOR SOME LIGHT SNOW SHOWERS ACTIVITY...WITH THE BEST CHC OF SEEING ACTIVITY ACROSS WESTERN AREAS AND THE HIGH TERRAIN. DESPITE WEAK LOW TO MID LEVEL WARM ADVECTION...H850 TEMPS WILL STILL BE -12C TO -16C FROM SOUTH TO NORTH OVER THE CWA. EXPECT HIGHS TO BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS IN THE MID TO U20S IN THE CAPITAL DISTRICT...THE MID HUDSON VALLEY...AND CT VALLEY. EXPECT TEENS TO L20S OVER THE MTNS...LAKE GEORGE REGION...W-CNTRL MOHAWK VALLEY...SRN VT...AND THE LITCHFIELD HILLS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... TONIGHT...THE FIRST OF TWO CLIPPERS PASSES SOUTH OF THE REGION WITH SCT SNOW SHOWERS/LIGHT SNOW ENDING FROM NORTH TO SOUTH. EXPECT MAINLY COATINGS TO A HALF AN INCH AROUND THE REGION. PORTIONS OF THE ERN CATSKILLS...AND WRN ADIRONDACKS COULD SEE AROUND AN INCH OR SO. THE FLOW VEERS TO THE W/NW AGAIN WITH THE UPPER LEVEL TROUGH OVER CNTRL-ERN CANADA CONTINUING TO THE DRIVE THE WX OVER NY AND NEW ENGLAND. MIN TEMPS WERE BLENDED FROM THE MET/MAV GUIDANCE WITH SINGLE DIGITS NORTH OF THE CAPITAL REGION...AND THE MOHAWK VALLEY...AND TEENS FROM THE I-90 CORRIDOR SOUTH AND EAST. SUNDAY-SUNDAY NIGHT...ANOTHER LULL IS BRIEFLY EXPECTED IN THE PARADE OF SHORT-WAVES/CLIPPERS IN THE W/NW FLOW ALOFT SUNDAY MORNING. THE GUIDANCE HAS TRENDED A BIT SLOWER WITH THE NEXT CLIPPER. SOME SLIGHT CHC POPS WERE PUT IN DURING THE LATE MORNING WEST OF THE HUDSON RIVER VALLEY...AND THEN CHC POPS WERE PUT IN EVERYWHERE IN THE PM INTO THE EVENING. THIS CLIPPER AND ITS ASSOCIATED SHORT- WAVE MOVE ACROSS THE CNTRL-ERN GREAT LAKES INTO THE REGION. THEIR IS SOME PRONOUNCED CYCLONIC VORTICITY ADVECTION WITH IT. THE DISTURBANCE WILL PRODUCE A ROUND OF LIGHT SNOW FOR THE REGION WITH GENERALLY A DUSTING TO AN INCH OR SO IN MOST LOCATIONS. THE SHORT- WAVE ENERGY WITH THIS CLIPPER WILL LIKELY PHASE WITH A STORM EAST OF THE GULF OF MAINE SUNDAY NIGHT. THE STORM WILL INTENSIFY AND DEEPEN NEAR THE CANADIAN MARITIMES. SOME WESTERLY UPSLOPE OR LAKE EFFECT SNOWFALL MAY IMPACT THE SRN GREENS AND WRN DACKS. WE HAVE 1-4" OF SNOW SUNDAY TO SUNDAY NIGHT IN THESE AREAS. HIGHS WILL RANGE FROM THE 20S TO L30S ACROSS THE REGION...TO SINGLE DIGITS TO TEENS FOR LOWS. MONDAY-MONDAY NIGHT...THE WORK WEEK WILL OPEN WITH BLUSTERY AND COLD CONDITIONS...AS A DEEPENING AND INTENSIFYING LOW PRESSURE SYSTEM MOVES TOWARD LABRADOR...AND ARCTIC HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES REGION AND ONTARIO. W/NW WINDS OF 15 TO 25 MPH WILL BE COMMON WITH SOME GUSTS AROUND 30-40 MPH. WESTERLY UPSLOPE SNOW SHOWERS OVER THE SRN GREENS AND WRN DACKS WILL END DURING THE AFTERNOON WITH ADDITIONAL LIGHT ACCUMULATIONS. IN THE COLD ADVECTION REGIME...H850 TEMPS FALL TO -17C TO -22C. MAX TEMPS WILL CONTINUE TO RUN BELOW NORMAL WITH TEENS TO M20S OVER THE HILLS AND MTNS...AND L20S TO L30S IN THE VALLEY AREAS. TEMPS MAY FALL DURING THE AFTERNOON. DIMINISHING WINDS AND FRIGID CONDITIONS ARE ANTICIPATED MON NIGHT WITH HIGH PRESSURE BUILDING IN WITH LOWS BELOW ZERO OVER THE ADIRONDACK PARK...AND SRN GREENS...SINGLE DIGITS EVERYWHERE ELSE...EXCEPT 10-15F IN THE MID HUDSON VALLEY AND SRN LITCHFIELD COUNTY. && .LONG TERM /TUESDAY THROUGH FRIDAY/... MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT KEEPING THE REGION UNDER A LONGWAVE TROUGH. A SHORT WAVE IS FORECAST TO MOVE THROUGH THE BASE OF THE TROUGH TUESDAY NIGHT INTO WEDNESDAY BRINGING THE THREAT FOR SOME SNOW SHOWERS. THE FLOW ALOFT IS EXPECTED TO BECOME MORE ZONAL WITH RIDGING BUILDING IN AT THE SURFACE AND IN THE LOW LEVELS OF THE ATMOSPHERE FOR THURSDAY BETWEEN SHORT WAVES AS THE UPPER LOW OVER EASTERN CANADA/HUDSONS BAY SHIFTS A BIT NORTHWARD. THE SURFACE HIGH WILL WEAKEN AND SHIFT EASTWARD AS ANOTHER SHORT WAVE TROUGH APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT. THE UPPER TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SHOULD CROSS THE REGION FRIDAY BRINGING WIDESPREAD CHANCES FOR SNOW SHOWERS. QPF SHOULD BE LIGHT SINCE MOISTURE ASSOCIATED WITH THE FEATURES WILL BE FAIRLY LIMITED. AS FOR TEMPERATURES LOOKING AT AROUND SEASONABLE LEVELS FOR EARLY FEBRUARY. SHOULD WARM TO A BIT ABOVE NORMAL ON FRIDAY AHEAD OF THE APPROACHING LOW PRESSURE SYSTEM. NORMALS FEB 5TH-8TH: ALBANY: HIGHS LOWER 30S. LOWS MID TEENS. GLENS FALLS: HIGHS LOWER 30S. LOWS UPPER SINGLE DIGITS. POUGHKEEPSIE: HIGHS UPPER 30S. LOWS UPPER TEENS. BENNINGTON: HIGHS LOWER 30S. LOWS MID TEENS. PITTSFIELD: HIGHS AROUND 30. LOWS MID TEENS. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... HIGHER PRESSURE OVER THE REGION THIS MORNING WILL WEAKEN AS A CLIPPER LOW APPROACHES FROM THE GREAT LAKES. THE CLIPPER LOW IS EXPECTED TO WEAKEN AS IT MOVES OVER THE REGION TONIGHT. THERE IS A CHANCE OF SNOW SHOWERS FROM MID/LATE AFTERNOON THROUGH THE EVENING. MAINLY VFR CONDITIONS ARE EXPECTED WITH MVFR POSSIBLE WITH ANY SNOW SHOWERS. MVFR SHOULD DEVELOP AFTER MIDNIGHT. SOUTH TO SOUTHWEST WINDS TODAY AHEAD OF THE APPROACHING CLIPPER LOW BECOMING LIGHT AND VARIABLE TONIGHT. OUTLOOK... SUN...MAINLY VFR. SUB-VFR WITH CHC LIGHT SNOW MID TO LATE AFTN. SUN NIGHT...MAINLY VFR. SUB-VFR WITH A LIGHT SNOW. AT KPSF SNOW LIKELY AFTER MIDNIGHT. MON-TUE...VFR. NO SIG WX. TUE NIGHT. MAINLY VFR. CHC -SHSN MAINLY AFTER MIDNIGHT. WED...MAINLY VFR. CHC -SHSN IN THE AM AND SLIGHT CHC IN THE AFTN. && .HYDROLOGY... THE NEXT 5 DAYS EXTENDING INTO THE MIDDLE OF NEXT WEEK WILL FEATURE NO HYDRO PROBLEMS. COLD TEMPS AND LIGHT PCPN SYSTEMS /SNOW AS THE PTYPE/ WILL ALLOW RIVERS AND STREAM TO CONTINUE TO RECEDE FROM LAST WEEKS STORM SYSTEM. THE BELOW NORMAL TEMPERATURES WILL ALLOW ICE TO REFORM AND THICKEN ON BODIES OF WATER IN THE ALBANY HYDRO SERVICE AREA. FOR SPECIFIC RIVER AND LAKE FORECASTS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS/WASULA NEAR TERM...FRUGIS/WASULA SHORT TERM...WASULA LONG TERM...IAA AVIATION...IAA HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
641 AM EST SAT FEB 2 2013 .SYNOPSIS... HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SOUTHERN QUEBEC THIS MORNING. A CLIPPER LOW WILL APPROACH FROM THE LOWER GREAT LAKES REGION WITH ISOLATED TO SCATTERED SNOW SHOWERS LATE THIS AFTERNOON INTO THIS EVENING. ANOTHER CLIPPER WILL IMPACT THE REGION LATE SUNDAY INTO SUNDAY NIGHT WITH SOME LIGHT SNOW AND CONTINUED BELOW NORMAL TEMPERATURES TO OPEN NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 640 AM EST...THE LAKE EFFECT SNOWS HAVE ENDED SOUTH AND WEST OF THE CAPITAL REGION WITH JUST SOME ISOLD SNOW SHOWERS AND FLURRIES AROUND...AS HIGH PRESSURE WILL BRIEFLY BUILD IN FROM SRN QUEBEC THIS MORNING. A WEAK STATIONARY BOUNDARY OVER UPSTATE NY AND NEW ENGLAND WILL LIFT BACK NORTHWARD AHEAD OF A WEAK LOW PRESSURE SYSTEM OVER GEORGIAN BAY. SOME NEW LAKE EFFECT SNOW SHOWERS HAVE REKINDLED OFF OF LAKE ONTARIO...AND ARE IMPACTING THE TUG HILL PLATEAU AT 1130 UTC. THE LOW AND MID LEVEL FLOW WILL CONTINUE TO BACK TO THE W/SW...AND LAKE EFFECT SNOWFALL WILL BREAK OUT FURTHER OVER EXTREME NRN NY OFF LAKE ONTARIO. A SW FLOW TRAJECTORY WILL NOT IMPACT THE ALY FCST AREA MUCH. THE 240 DEGREE TRAJECTORY IS EXPECTED TO IMPACT LOCATIONS JUST NORTH AND WEST OF THE WRN DACKS. THE LATEST ALY HIRES WRF COMPOSITE REFLECTIVITY...AND 3-KM HRRR SHOW LITTLE IMPACT IN OUR AREA TODAY. WE KEPT SOME HIGH CHC AND LIKELY POPS NORTH OF OLD FORGE IN HERKIMER COUNTY...AND NW HAMILTON COUNTIES. THERE IS SOME WEAK WARM ADVECTION WITH THE BOUNDARY TOO...SO SOME SLIGHT AND LOW CHC POPS WERE EXPANDED SOUTH TO THE W-CNTRL MOHAWK VALLEY. ANOTHER CLIPPER LOW MOVING ACROSS WI/IL THIS MORNING WILL APPROACH THE REGION FOR LATE THIS AFTERNOON...AND TONIGHT WITH SOME SCATTERED SNOW SHOWERS OR LIGHT SNOW. THE SHORT-WAVE TO THIS CLIPPER IS MOVING INTO THE MIDWEST THIS MORNING VIA THE WATER VAPOR LOOP. CHC POPS WERE EXPANDED OVER MOST OF THE FCST AREA LATE THIS AFTERNOON INTO EARLY THIS EVENING. DESPITE WEAK LOW TO MID LEVEL WARM ADVECTION...H850 TEMPS WILL STILL BE -12C TO -16C FROM SOUTH TO NORTH OVER THE CWA. EXPECT HIGHS TO BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS IN THE MID TO U20S IN THE CAPITAL DISTRICT...THE MID HUDSON VALLEY...AND CT VALLEY. EXPECT TEENS TO L20S OVER THE MTNS...LAKE GEORGE REGION...W-CNTRL MOHAWK VALLEY...SRN VT...AND THE LITCHFIELD HILLS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... TONIGHT...THE FIRST OF TWO CLIPPERS PASSES SOUTH OF THE REGION WITH SCT SNOW SHOWERS/LIGHT SNOW ENDING FROM NORTH TO SOUTH. EXPECT MAINLY COATINGS TO A HALF AN INCH AROUND THE REGION. PORTIONS OF THE ERN CATSKILLS...AND WRN ADIRONDACKS COULD SEE AROUND AN INCH OR SO. THE FLOW VEERS TO THE W/NW AGAIN WITH THE UPPER LEVEL TROUGH OVER CNTRL-ERN CANADA CONTINUING TO THE DRIVE THE WX OVER NY AND NEW ENGLAND. MIN TEMPS WERE BLENDED FROM THE MET/MAV GUIDANCE WITH SINGLE DIGITS NORTH OF THE CAPITAL REGION...AND THE MOHAWK VALLEY...AND TEENS FROM THE I-90 CORRIDOR SOUTH AND EAST. SUNDAY-SUNDAY NIGHT...ANOTHER LULL IS BRIEFLY EXPECTED IN THE PARADE OF SHORT-WAVES/CLIPPERS IN THE W/NW FLOW ALOFT SUNDAY MORNING. THE GUIDANCE HAS TRENDED A BIT SLOWER WITH THE NEXT CLIPPER. SOME SLIGHT CHC POPS WERE PUT IN DURING THE LATE MORNING WEST OF THE HUDSON RIVER VALLEY...AND THEN CHC POPS WERE PUT IN EVERYWHERE IN THE PM INTO THE EVENING. THIS CLIPPER AND ITS ASSOCIATED SHORT- WAVE MOVE ACROSS THE CNTRL-ERN GREAT LAKES INTO THE REGION. THEIR IS SOME PRONOUNCED CYCLONIC VORTICITY ADVECTION WITH IT. THE DISTURBANCE WILL PRODUCE A ROUND OF LIGHT SNOW FOR THE REGION WITH GENERALLY A DUSTING TO AN INCH OR SO IN MOST LOCATIONS. THE SHORT- WAVE ENERGY WITH THIS CLIPPER WILL LIKELY PHASE WITH A STORM EAST OF THE GULF OF MAINE SUNDAY NIGHT. THE STORM WILL INTENSIFY AND DEEPEN NEAR THE CANADIAN MARITIMES. SOME WESTERLY UPSLOPE OR LAKE EFFECT SNOWFALL MAY IMPACT THE SRN GREENS AND WRN DACKS. WE HAVE 1-4" OF SNOW SUNDAY TO SUNDAY NIGHT IN THESE AREAS. HIGHS WILL RANGE FROM THE 20S TO L30S ACROSS THE REGION...TO SINGLE DIGITS TO TEENS FOR LOWS. MONDAY-MONDAY NIGHT...THE WORK WEEK WILL OPEN WITH BLUSTERY AND COLD CONDITIONS...AS A DEEPENING AND INTENSIFYING LOW PRESSURE SYSTEM MOVES TOWARD LABRADOR...AND ARCTIC HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES REGION AND ONTARIO. W/NW WINDS OF 15 TO 25 MPH WILL BE COMMON WITH SOME GUSTS AROUND 30-40 MPH. WESTERLY UPSLOPE SNOW SHOWERS OVER THE SRN GREENS AND WRN DACKS WILL END DURING THE AFTERNOON WITH ADDITIONAL LIGHT ACCUMULATIONS. IN THE COLD ADVECTION REGIME...H850 TEMPS FALL TO -17C TO -22C. MAX TEMPS WILL CONTINUE TO RUN BELOW NORMAL WITH TEENS TO M20S OVER THE HILLS AND MTNS...AND L20S TO L30S IN THE VALLEY AREAS. TEMPS MAY FALL DURING THE AFTERNOON. DIMINISHING WINDS AND FRIGID CONDITIONS ARE ANTICIPATED MON NIGHT WITH HIGH PRESSURE BUILDING IN WITH LOWS BELOW ZERO OVER THE ADIRONDACK PARK...AND SRN GREENS...SINGLE DIGITS EVERYWHERE ELSE...EXCEPT 10-15F IN THE MID HUDSON VALLEY AND SRN LITCHFIELD COUNTY. && .LONG TERM /TUESDAY THROUGH FRIDAY/... MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT KEEPING THE REGION UNDER A LONGWAVE TROUGH. A SHORT WAVE IS FORECAST TO MOVE THROUGH THE BASE OF THE TROUGH TUESDAY NIGHT INTO WEDNESDAY BRINGING THE THREAT FOR SOME SNOW SHOWERS. THE FLOW ALOFT IS EXPECTED TO BECOME MORE ZONAL WITH RIDGING BUILDING IN AT THE SURFACE AND IN THE LOW LEVELS OF THE ATMOSPHERE FOR THURSDAY BETWEEN SHORT WAVES AS THE UPPER LOW OVER EASTERN CANADA/HUDSONS BAY SHIFTS A BIT NORTHWARD. THE SURFACE HIGH WILL WEAKEN AND SHIFT EASTWARD AS ANOTHER SHORT WAVE TROUGH APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT. THE UPPER TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SHOULD CROSS THE REGION FRIDAY BRINGING WIDESPREAD CHANCES FOR SNOW SHOWERS. QPF SHOULD BE LIGHT SINCE MOISTURE ASSOCIATED WITH THE FEATURES WILL BE FAIRLY LIMITED. AS FOR TEMPERATURES LOOKING AT AROUND SEASONABLE LEVELS FOR EARLY FEBRUARY. SHOULD WARM TO A BIT ABOVE NORMAL ON FRIDAY AHEAD OF THE APPROACHING LOW PRESSURE SYSTEM. NORMALS FEB 5TH-8TH: ALBANY: HIGHS LOWER 30S. LOWS MID TEENS. GLENS FALLS: HIGHS LOWER 30S. LOWS UPPER SINGLE DIGITS. POUGHKEEPSIE: HIGHS UPPER 30S. LOWS UPPER TEENS. BENNINGTON: HIGHS LOWER 30S. LOWS MID TEENS. PITTSFIELD: HIGHS AROUND 30. LOWS MID TEENS. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... HIGHER PRESSURE OVER THE REGION THIS MORNING WILL WEAKEN AS A CLIPPER LOW APPROACHES FROM THE GREAT LAKES. THE CLIPPER LOW IS EXPECTED TO WEAKEN AS IT MOVES OVER THE REGION TONIGHT. THERE IS A CHANCE OF SNOW SHOWERS FROM MID/LATE AFTERNOON THROUGH THE EVENING. MAINLY VFR CONDITIONS ARE EXPECTED WITH MVFR POSSIBLE WITH ANY SNOW SHOWERS. MVFR SHOULD DEVELOP AFTER MIDNIGHT. SOUTH TO SOUTHWEST WINDS TODAY AHEAD OF THE APPROACHING CLIPPER LOW BECOMING LIGHT AND VARIABLE TONIGHT. OUTLOOK... SUN...MAINLY VFR. SUB-VFR WITH CHC LIGHT SNOW MID TO LATE AFTN. SUN NIGHT...MAINLY VFR. SUB-VFR WITH A LIGHT SNOW. AT KPSF SNOW LIKELY AFTER MIDNIGHT. MON-TUE...VFR. NO SIG WX. TUE NIGHT. MAINLY VFR. CHC -SHSN MAINLY AFTER MIDNIGHT. WED...MAINLY VFR. CHC -SHSN IN THE AM AND SLIGHT CHC IN THE AFTN. && .HYDROLOGY... THE NEXT 5 DAYS EXTENDING INTO THE MIDDLE OF NEXT WEEK WILL FEATURE NO HYDRO PROBLEMS. COLD TEMPS AND LIGHT PCPN SYSTEMS /SNOW AS THE PTYPE/ WILL ALLOW RIVERS AND STREAM TO CONTINUE TO RECEDE FROM LAST WEEKS STORM SYSTEM. THE BELOW NORMAL TEMPERATURES WILL ALLOW ICE TO REFORM AND THICKEN ON BODIES OF WATER IN THE ALBANY HYDRO SERVICE AREA. FOR SPECIFIC RIVER AND LAKE FORECASTS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...WASULA NEAR TERM...WASULA SHORT TERM...WASULA LONG TERM...IAA AVIATION...IAA HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
556 AM EST SAT FEB 2 2013 .UPDATE... NOTEABLE 3HR PRES FALL MAX OVR NE IL/NW IN THIS MORNING W/COOLING IR CLD TOPS NOTED WITHIN BURGEONING RADAR RTNS FM NE IL ACRS SRN LK MI AND INTO SW MI. WHILE SNOW SHIELD HAS BEEN FAIRLY RAGGED SO FAR XPC MORE ERSTWHILE DVLPMNT NR TERM IN LINE W/LATEST RUC DATA AND SEEN IN UPSTREAM RADAR TRENDS. IN FACT NOTED BANDING TAKING PLACE OVR NE IL/SRN LK MI ATTM W/WIDESPREAD 30DBZ+ RTNS NOTED AND INDICATIVE OF SNOWFALL RATES NR 1 INCH PER HOUR. WILL BUMP 12-18Z QPF/SNOW GRIDS SLIGHTLY ESP OVR BERRIEN COUNTY AS SOME LK ENHANCMENT IS OCCURRING. OTRWS GIST OF PRIOR FCST HOLDS THIS AFTN. && .SHORT TERM... TODAY THROUGH SUNDAY NIGHT...THE CHALLENGES THIS PERIOD INCLUDE A NUMBER OF OPPORTUNITIES FOR SNOW INCLUDING A FAST MOVING CLIPPER TYPE OF SYSTEM TODAY...LAKE EFFECT SNOW TONIGHT AND SUNDAY...AND A SECOND FAST MOVING SYSTEM ARRIVING SUNDAY NIGHT OR MONDAY. FOR THIS PACKAGE...FAVORED THE SRF. THE FIRST SYSTEM...THE LEFT EXIT REGION OF UPPER JET WAS HELPING TO GENERATE SNOW OVER MUCH OF THE FORECAST AREA EARLY THIS MORNING IN A VERY COLD AIRMASS LINGERING OVER THE REGION. MOISTURE WAS LIMITED...BUT ISENTROPIC LIFT AND SOME UPPER LEVEL JET SUPPORT WAS HELPING TO SUSTAIN THE SNOW. THE ISENTROPIC LIFT SHOULD BE MOST FAVORABLE BETWEEN 09Z AND 15Z. THEREFORE...WILL KEEP WIDESPREAD LIGHT SNOW ACCUMULATIONS TODAY...WITH SNOW TAPERING THIS AFTERNOON. CURRENT THINKING IS SNOW ACCUMULATIONS SHOULD BE AROUND AN INCH. FOR TONIGHT AND SUNDAY... POOR LAKE EFFECT SNOW SET UP IN A HIGHLY SHEARED LOW LEVEL ENVIRONMENT...ALTHOUGH DELTA T VALUES DO SUPPORT LAKE EFFECT SNOW. LOW LEVEL SUBSIDENCE REALLY INCREASES LATER TODAY AND SHOULD LIMIT SNOWFALL AND INTENSITY. REDUCED SNOW CHANCES CONSIDERABLY ALL AREAS TONIGHT GIVEN LACK OF FORCING AND UPPER LEVEL SUPPORT FOR WIDESPREAD SNOW. FOR THE SECOND CLIPPER SYSTEM...KEPT A CHANCE FOR SNOW LATE SUNDAY NIGHT...WITH A MUCH BETTER CHANCE FOR SNOW MONDAY AS ISENTROPIC LIFT INCREASES. && .LONG TERM... COLD PNA PATTN OF LATE ANCHORED BY DEEP POLAR TROUGH OVR HUDSON BAY AND LW RIDGE ALG THE W COAST OF NOAM WILL RELAX THIS PD AS POLAR TROUGH MIGRATES INTO BAFFIN BAY. RESULTING FLW PATTN WILL FLATTEN OUT TO WRLY ACRS THE CONUS W/SIG WARMUP XPCD LT PD. UNTIL THEN HWVR HAVE TO CONTEND W/CONTD PARADE OF SW RIPPLES EMBEDDED WITHIN STILL FAIRLY STEEP NWRLY FLW ALOFT. 3RD SW OF NOTE WILL DIVE DOWN ACRS THE SRN LAKES ON MON AND CONT TO FVR SRN CONSENSUS OF SOLUTIONS W/TRACK OF THIS SW CNTRD OVR CNTRL IN. WHILE MSTR RTN AGAIN LIMITED...ROBUST ISENTROPIC RESPONSE XPCD WITHIN ENTRANCE REGION OF UPR JET COLLOCATED W/TIGHT BAROCLINIC ZONE. GIVEN PWS ARE A BIT BTR THAN NR TERM SYS...XPCD SIMILAR EVOLUTION W/GENERAL 1-3 IN SNOWFALL ACRS THE AREA...HEAVIEST CNTRL/SW. WILL BUMP POP SIGLY GIVEN GOOD INTERMODEL AGREEMENT. 4TH SYS FOLLOWS QUICKLY LT TUE. HWVR PLACEMENT OF UPR JET AND SOMEWHAT WEAKER RESPONSE ALOFT W/MORE LIMITED MSTR SUGGESTS MUCH LIGHTER SNOW. BEYOND THAT...FLW PATTN BREAKS DOWN W/WRN TROUGHING DVLPG TWD LT PD. LEAD SYS BREAKING EWD OUT OF EPAC IN THIS TRANSITION WILL CROSS THE AREA ON THU. EC/GFS SIMILAR IN SCOPE W/NARROW BUT IMPORTANT THETA-E RIDGING DVLPG INADV AND IMPLY A POTENTIAL MIX FAR S/SW LT THU. REGARDLESS SOME ENTRAINMENT OF FLEDGELING ERN GOMEX MSTR PLUME PSBL AND WILL BRIDGE GOING POPS HIGHER. && .AVIATION... LEFT EXIT REGION OF UPPER JET AXIS HELPING TO GENERATE SNOW UPSTREAM INTO NRN INDIANA IN VERY COLD AIRMASS LINGERING OVER THE REGION. MOISTURE SOMEWHAT LIMITED...BUT VERY EFFICIENT SETUP TO PRODUCE SNOW WITH VISIBILITIES DOWN TO 1 MILE. MADE SOME MAINLY MINOR UPDATES TO THE ONGOING TAFS WITH THIS NEW ISSUANCE. VSBYS SHOULD IMPROVE AFTER CLIPPER TYPE SYSTEM MOVES THROUGH...ALTHOUGH EXPECT CIGS TO REMAIN MVFR. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR LMZ043-046. && $$ SHORT TERM...SKIPPER LONG TERM...T AVIATION...SKIPPER UPDATE...T
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1013 AM EST SAT FEB 2 2013 .SYNOPSIS... NORTHWEST FLOW WILL KEEP COLD AIR FUNNELING DOWN OVER THE MID ATLANTIC STATES THROUGH WEDNESDAY. A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL QUICKLY PASS THROUGH THE REGION THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... NEXT CLIPPER SYSTEM ON TRACK TO IMPACT THE REGION WITH LIGHT SNOW STARTING THIS AFTERNOON AND CONTINUING THROUGH THE EVENING HOURS. NOT MUCH IN THE WAY OF UPPER LEVEL DYNAMICS WITH THIS SYSTEM...SO AM NOT EXPECTING ANYTHING OTHER A PERIOD OF LIGHT SNOW STARTING DURING THE AFTERNOON AND ENDING LATE THIS EVENING. AT THE SURFACE... HIGH PRESSURE OVERHEAD WILL MOVE EAST OF THE AREA THIS AFTERNOON AHEAD OF THE CLIPPER LOW SYSTEM. THE LATEST 12Z NAM SHOWS A FAIRLY DRY SYSTEM WITH ONLY LIGHT QPF AMOUNTS OF LESS THAN 0.1 LIQUID...WTIH SNOW- LIQUID RATIOS OF 10 TO 12 TO ONE AS SHOWN BY THE 09Z/SREF. OTHER HI-RES MODELS ALL AGREE ON TIMING THE SYSTEM ACROSS THE REGION THIS AFTERNOON AND EVENING BUT DIFFER IN DETAILS OF SNOW AND ANY ATTENDANT SNOW BANDING. THE 11Z 3KM HRRR IS TRENDING TO A WEAKER SYSTEM MOVING THROUGH WITH LESS SNOWFALL POTENTIAL...WHEREAS THE 00Z 4KM NCEP WRF NMM SHOWS A SLIGHTLY STRONG SYSTEM...ON A PAR WITH YESTERDAYS CLIPPER. CURRENT FORECAST HAD THE TIMING COVERED PRETTY WELL...AND I ONLY MADE SOME MINOR ADJUSTMENTS TO THAT TIMING. FOR SNOWFALL AMOUNTS... GIVING CURRENT SPEED OF THE CLIPPER...EXPECTING A 4 TO 6 HR PERIOD WHERE OCCASSIONAL LIGHT SNOW WILL FALL. AIRMASS IS VERY DRY... DULLES RAOB ONLY 0.18 INCHES...WITH FORECAST SOUNDINGS SHOWING AT MOST 0.4 INCHES OF PRECIPITABLE WATER THIS AFTENROON AND EARLY EVENING. DID NOT MAKE ANY CHANGES FOR CURRENT SNOW TOTAL GRAPHIC FOR THE 930 AM UPDATE. TEMPERATURES WILL BE UNSEASONABLY COLD TODAY MAINLY AT OR BELOW FREEZING IN MOST LOCATIONS...AND AFTER LAST NIGHTS COLD READINGS ANY SNOW THAT FALLS WILL STICK ON UNTREATED SURFACES. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SUNDAY/... THE UPPER LEVEL WAVE/CLIPPER SYSTEM WILL BE SCOOTING OFF QUICKLY TO THE EAST DURING THE EVENING HOURS...ENDING THE SNOW THREAT FOR ALL AREAS...EXCEPT IN THE WESTERN UPSLOPE AREAS OF WESTERN MD/VA/WV. FOR SUN...ANOTHER UPPER LEVEL DISTURBANCE CLIPPER LIKE SYSTEM APPROACHES THE REGION DURING THE MORNING AND CROSSES DURING THE AFTERNOON HOURS. THIS SYSTEM HAS A LITTLE MORE IN THE WAY OF UPPER DYNAMICS ASSOCIATED WITH IT...AND WOULD EXPECT TO SEE A BAND OR TWO OF SNOW SHOWERS PASS ACROSS THE REGION DURING THE AFTERNOON HOURS. TEMPS ON SUN EXPECTED TO BE 4 TO 6 DEGREES WARMER ON SUN. ANY SNOW BANDS THAT COME THROUGH COULD PRODUCE A QUICK COATING OF SNOW...BUT TEMPS SHOULD BE ABOVE FREEZING IN MOST AREAS. WILL CONTINUE TO MONITOR. PREVIOUS DISCUSSIONS FOLLOW. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... SUNDAY A SHEARED BUT POTENT SHORT WAVE WILL SLIDE EAST ACROSS THE REGION...AND WE COULD SEE SOME SNOW SHOWERS WITH THAT. THE MAIN THREAT WINDOW IS IN THE LATE MORNING THRU LATE AFTERNOON. ANY ACCUM IS EXPECTED TO BE LESS THAN AN INCH...EXCEPT AROUND AN INCH IN THE MOUNTAINS. NEXT UP IS A CLIPPER MOVING EAST ACROSS THE MID ATLANTIC MONDAY NIGHT WITH ANOTHER CHANCE AT A LIGHT ACCUMULATION. AND THIRD IS ANOTHER CLIPPER PUSHING SOUTHEAST INTO NC WHICH BRINGS ANOTHER CHANCE OF LIGHT ACCUMULATION ON TUESDAY NIGHT. THE GFS AND EURO ARE IN GOOD AGREEMENT WITH THE TIMING OF BOTH OF THESE FEATURES AND THEIR INTENSITIES. AFTER THAT A SFC LOW IS SLATED TO CROSS TO OUR NORTH AND BRING A COLD FRONT THROUGH US ON FRIDAY. BUT IT WILL NOT BE MUCH OF A COLD FRONT AS RIDGING BUILDS IN QUICKLY BEHIND WITH MILDER TEMPS...AND BASED ON THE LATEST WEEK TWO FORECASTS FROM THE NWS CLIMATE PREDICTION CENTER...THOSE MILD TEMPS ARE EXPECTED TO DOMINATE THE FOLLOWING WEEK. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... EXPECT A FEW PERIODS OF LIGHT SNOW TO DEVELOP THIS AFTERNOON AS THE NEXT CLIPPER SYSTEM MOVES EAST. CIGS SHOULD DROP TO AROUND 3KFT AND VSBYS COULD LOWER BRIEFLY TO 1 TO 2 MILES. HAVE ADJST TAFS TO REFLECT THIS. THE SNOW SHOULD BE SHORT-LIVED AND WILL BE MOVING AWAY FROM THE AREA DURING THE 01-03Z TIMEFRAME THIS EVENING. IFR CONDITIONS ARE POSSIBLE IN ANY SNOW SHOWERS ON SUNDAY...AND AGAIN WITH SNOW SHOWERS WITH MON NIGHT AND TUE NIGHT SHORT WAVES. && .MARINE... HIGH PRES TODAY WILL MOVE EAST IN ADVANCE OF THE CLIPPER SYSTEM. WINDS COME AROUND TO S TO SW THIS AFTERNOON WITH A FEW 15 KT GUSTS POSSIBLE. PERIODS OF LIGHT SNOW OVERSPREADING THE WATERS DURING THE AFTERNOON BUT ENDING DURING THE MID EVENING HOURS. ON SUN...ANOTHER UPPER LEVEL DISTURBANCE MOVES ACROSS THE WATER DURING THE AFTERNOON. WINDS MAY INCREASE AFTER PASSAGE OF THIS SYSTEM SUN AFTERNOON AND SMALL CRAFT ADV WINDS ARE EXPECTED SUNDAY AFTERNOON INTO MONDAY AFTERNOON. THAT IS EXPECTED TO AGAIN BE THE CASE ON WEDNESDAY AFTER THE CLIPPER. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 PM SUNDAY TO 3 PM EST MONDAY FOR ANZ530>543. && $$ SYNOPSIS...SMZ NEAR TERM...SMZ SHORT TERM...SMZ LONG TERM...CAS AVIATION...SMZ MARINE...SMZ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
422 AM CST SAT FEB 2 2013 .SHORT TERM...TODAY THROUGH SUNDAY... THE MAIN HIGHLIGHTS OF THE SHORT TERM ARE STRONG WINDS AND LIGHT ACCUMULATING SNOW THROUGH TONIGHT. LIGHT SNOW CONTINUES ACROSS CENTRAL NORTH DAKOTA THIS MORNING AS ANOTHER IMPULSE MOVES OVER THE AREA...WITH A SHARP GRADIENT ALONG THE EASTERN PERIPHERY OF THE SURFACE ARCTIC HIGH PRESSURE TO THE EAST. GUIDANCE FROM THE RAP AND 06Z NAM HAVE CAPTURED THIS SCENARIO WELL THIS MORNING AND THUS HAVE DECIDED TO USE THEM AS A GUIDE FOR THE CLIPPER SYSTEM THAT IS FORECAST TO MOVE OVER THE AREA LATER THIS MORNING THROUGH THIS EVENING. THIS CLIPPER SYSTEM WILL MOVE ALONG AND INTERACT WITH THE BAROCLINIC ZONE...GENERATING ANOTHER ROUND OF LIGHT SNOW FOR CENTRAL AND EASTERN NORTH DAKOTA. LIGHT SNOWFALL ACCUMULATIONS ARE EXPECTED AND GENERALLY AROUND AN INCH NORTH AND EAST OF THE MISSOURI RIVER...WITH UP TO TWO INCHES POSSIBLE FOR THE JAMES RIVER VALLEY. LATER THIS MORNING...00Z GFS/NAM BUFR SOUNDINGS DEPICT LAPSE RATES BECOMING NEARLY ADIABATIC ALLOWING FOR 45 KT H850 WINDS TO BE MIXED DOWN TO THE SURFACE. COINCIDENT WITH STEEPENING LAPSE RATES OVER THE AREA...MODEST ISALLOBARIC FORCING OF 6 MB SIX HOUR PRESSURE RISES WILL MOVE OVER THE AREA. IF DOWNWARD MOMENTUM CAN BE ACHIEVED...H850 WINDS WILL BE TRANSLATED DOWN TO THE SURFACE...GENERATING WIDESPREAD GUSTS OF 45 KTS. MODELS ARE IN GOOD AGREEMENT REGARDING THE OVERALL SEVERITY...BUT THERE IS SOME DISAGREEMENT REGARDING TIMING. THE ECMWF SEEMS TO BE QUICK TO CUT OFF THE STRONGEST WINDS BY 00Z...WITH OTHER MODELS HOLDING THE STRONGEST WINDS THROUGH 03Z OVER THE SOUTHEAST. IN ADDITION TO STRONG WINDS...AREAS OF BLOWING SNOW ARE POSSIBLE. THE STRONGEST WINDS WILL NOT COINCIDE WITH THE HEAVIEST SNOWFALL...AND WILL BE FURTHER HAMPERED BY ABOVE FREEZING TEMPERATURES ACROSS MUCH OF THE AREA. HOWEVER...AREAS OF BLOWING SNOW AND REDUCED VISIBILITIES WILL BE POSSIBLE FOR AREAS NORTH AND EAST OF THE MISSOURI RIVER...WHERE THE HEAVIEST SNOWFALL TOTALS AND SUBFREEZING TEMPERATURES WILL BE SEEN. AS A RESULT...HAVE DECIDED NOT TO ISSUE ANY ADVISORY HEADLINES FOR BLOWING SNOW AND KEEP THE WIND ADVISORY AS IS EXCEPT FOR THE SOUTHEAST WHERE IT HAS BEEN EXTENDED IN TIME. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY... THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD WILL BE A COUPLE OF LIGHT SNOW EVENTS OVER THE NORTHEAST HALF OF THE FORECAST AREA. NORTHWEST FLOW WILL BE IN PLACE ACROSS THE REGION AT THE BEGINNING OF THE LONG TERM PERIOD. MODEL CONSENSUS CONTINUES TO SUPPORT A FEW PERIODS OF SHORT WAVE ENERGY DIVING SOUTHEAST INTO THE STATE. HAVE INCREASED POPS ACROSS THE NORTH AND EAST FOR SUNDAY NIGHT...MONDAY...AND MONDAY NIGHT. THESE AREAS ARE FAVORED FOR MINOR ACCUMULATIONS RANGING FROM A DUSTING TO AROUND TWO INCHES. COMPLICATING FACTORS SUCH AS STRONG WIND AND BLOWING SNOW ARE NOT EXPECTED. FORECAST BUFR SOUNDINGS CONTINUE TO INDICATE A MODEST WARM LAYER ALOFT AND THE POTENTIAL FOR SOME SLEET AT TIMES ON THE BACK EDGE OF THE PRECIP. UPPER FLOW WILL TRANSITION FROM ZONAL TO SOUTHWEST...TUESDAY THROUGH FRIDAY. SOME ADDITIONAL LIGHT SNOW COULD CLIP THE FAR NORTH WEDNESDAY...OTHERWISE EXPECT MAINLY DRY WEATHER WITH RELATIVELY MILD AFTERNOON HIGHS IN THE 20S AND 30S. && .AVIATION... LOW PRESSURE WILL DROP SOUTHEAST ACROSS CENTRAL AND INTO SOUTHEAST NORTH DAKOTA ON SATURDAY. LIGHT NORTH TO NORTHWEST WINDS WILL SHIFT SOUTH TO SOUTHWEST LATE TONIGHT THEN BACK NORTHWEST ON SATURDAY BEHIND THE SURFACE LOW. WINDS WILL BECOME GUSTY BY SATURDAY AFTERNOON THEN DIMINISH BY SATURDAY EVENING. WIDESPREAD MVFR-IFR CEILINGS AND VISIBILITIES WILL REMAIN OVER WESTERN AND CENTRAL NORTH DAKOTA AHEAD OF THE APPROACHING SURFACE LOW. LOWEST VISIBILITIES IN SNOW WILL REMAIN FROM MINOT TO JAMESTOWN ON SATURDAY...CLOSE TO THE TRACK OF THE LOW. EXPECT IMPROVING CEILINGS SATURDAY EVENING FROM WEST TO EAST. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 9 AM CST /8 AM MST/ THIS MORNING TO 6 PM CST /5 PM MST/ THIS EVENING FOR NDZ001>003-009>011-017>021-031>035- 040>046. WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR NDZ004-005-012-013-022-023-025-036-037-047-048-050-051. && $$ SHORT TERM...HUBER LONG TERM...KINNEY AVIATION...HAMILTON
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
934 AM EST SAT FEB 2 2013 .SYNOPSIS... A CLIPPER SYSTEM WILL TRACK EAST ACROSS THE GREAT LAKES AND OHIO VALLEY THROUGH TONIGHT. A WEAK UPPER LEVEL WEATHER DISTURBANCE WILL AFFECT THE REGION ON SUNDAY. HIGH PRESSURE WILL BUILD BRIEFLY INTO THE OHIO VALLEY SUNDAY NIGHT. THE HIGH WILL MOVE EAST ON MONDAY AS ANOTHER CLIPPER SYSTEM QUICKLY MOVES TOWARD THE OHIO VALLEY FROM THE NORTHWEST. && .NEAR TERM /THROUGH TONIGHT/... SNOW HAS OVERSPREAD THE FORECAST AREA. NAM AND RAP MODELS HAVE GOOD REPRESENTATIONS OF THE AREA OF SNOW. ACCUMULATIONS HAVE BEEN UP TO AN INCH IN SOUTHWEST COUNTIES. THE BEST ISENTROPIC LIFT WILL OCCUR AHEAD OF THE WEAK SFC LOW AND FRONT. THUS...MUCH OF THE SNOW ACCUMULATION WILL OCCUR DURING THE DAYLIGHT HOURS. THE SNOW WILL TAPER OFF FROM WEST TO EAST THIS EVENING AS THE CLIPPER MOVES OFF TO THE EAST. USING A BLEND OF MODEL QPF AND SNOW TO LIQUID RATIOS BASED ON TEMPERATURE...IT STILL LOOKS LIKE A GOOD 2 TO 3 INCH SNOW EVENT AREA WIDE WITH ISOLATED AMOUNTS NEAR 4 INCHES. A WINTER WEATHER ADVISORY WILL REMAIN IN EFFECT THROUGH TONIGHT. WITH LOW LEVEL WAA...HIGHS TODAY SHOULD RANGE FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. IN CAA BEHIND THE DEPARTING CLIPPER...OVERNIGHT LOWS SHOULD RANGE FROM THE MID TEENS NORTHWEST TO THE LOWER 20S SOUTHEAST. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... OUR REGION WILL REMAIN UNDER A NORTHWEST FLOW PATTERN ALOFT THROUGH THE SHORT TERM PERIOD. THIS PATTERN WILL ALLOW SEVERAL WEATHER SYSTEMS TO AFFECT THE AREA. ON SUNDAY...A SHEARED OUT WEAK UPR LVL WX DISTURBANCE WILL PASS ACRS THE REGION. THIS FEATURE WILL KEEP SKIES MAINLY CLOUDY ALONG WITH A CHANCE OF SNOW SHOWERS. THE WEAK DISTURBANCE WILL EXIT THE AREA BY SUNDAY EVENING. DESPITE SURFACE HIGH PRESSURE BRIEFLY BUILDING INTO THE OHIO VALLEY...CLOUDS WILL CONTINUE TO SPILL SOUTHEAST FROM THE NEXT CLIPPER SYSTEM WHICH WILL LIMIT ANY OPPORTUNITY TO CLEAR OUT. FOR MONDAY INTO MONDAY NIGHT...MODELS ALL INDICATE THAT A CLIPPER SYSTEM WILL TRACK SOUTHEAST THROUGH THE OHIO VALLEY. AM CONFIDENT ENOUGH AT THIS POINT TO RAISE POPS TO LIKELY FOR MONDAY AFTERNOON INTO MONDAY NIGHT. THERE CONTINUES TO BE STRENGTH ISSUES WITH THE LOW AND ITS ASSOCIATED WAA/LOW LEVEL JET WHICH WILL ULTIMATELY DICTATE PCPN TYPE AND SNOW ACCUMULATIONS. AT THIS POINT IT LOOKS LIKE MUCH OF THE AREA NORTH OF THE OHIO RIVER WILL SEE SNOW WHILE RAIN MAY MIX WITH SNOW ALONG AND SOUTH OF THE RIVER MONDAY AFTERNOON INTO MONDAY EVENING UNTIL CAA CHANGES THE PCPN TO ALL SNOW BEFORE TAPERING OFF LATE. AGAIN...WE SHOULD SEE SOME ACCUMULATIONS BUT AMOUNTS ARE STILL UNCERTAIN AT THIS POINT DUE TO REASONS JUST MENTIONED. WILL SPELL THIS OUT IN THE HWO PRODUCT. LITTLE RESPITE IS EXPECTED TUESDAY INTO TUESDAY NIGHT AS ANOTHER CLIPPER SYSTEM WILL BE ON THE HEELS OF THE MONDAY/MONDAY NIGHT SYSTEM. THERE CONTINUES TO BE PLACEMENT ISSUES WITH THIS FEATURE IN HOW FAR SOUTH IT WILL DIG. HAVE KEPT POPS IN THE CHANCE CATEGORY UNTIL MODELS RESOLVE THIS DILEMMA. PCPN WILL BE IN THE FORM OF SNOW NORTH WITH RAIN/SNOW POSSIBLE SOUTH. AS FOR TEMPERATURES...THEY WILL BE HARD TO PINPOINT GIVEN SNOW COVER AND SURFACE LOW PLACEMENT WITH THE UPCOMING CLIPPER SYSTEMS WHICH WILL RESULT IN SFC WAA AHEAD OF THE LOW CENTER. MAINLY USED A BLEND OF THE GFS/ECMWF SURFACE TEMPERATURES ALONG WITH CLIMATOLOGICAL THICKNESS SCHEMES. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... HIGH PRESSURE WILL BE IN PLACE ACROSS THE AREA FOR WEDNESDAY AND WILL MOVE EAST OF THE FA ON THURSDAY. WITH SOUTHERLY FLOW ON THURSDAY TEMPERATURES WILL RANGE FROM THE MIDDLE 30S TO THE MIDDLE 40S ACROSS THE REGION. PRECIPITATION WILL BEGIN TO MOVE INTO THE FA THURSDAY EVENING AND BECOME MORE WIDESPREAD ACROSS THE AREA THURSDAY NIGHT AS A COLD FRONT APPROACHES AND MOVES THROUGH THE REGION. PRECIPITATION WILL TAPER OFF ACROSS THE FA DURING THE MORNING HOURS ON FRIDAY AND HIGH PRESSURE WILL WORK BACK INTO THE REGION FRIDAY AFTERNOON. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... SNOW IS NOW MOVING INTO THE TAF SITES...WITH VISIBILITIES QUICKLY DROPPING INTO THE IFR CATEGORY JUST AFTER PRECIPITATION ONSET. CEILINGS IN THE SNOW ARE ANYWHERE FROM VFR TO IFR...THOUGH IFR CEILINGS HAVE BEEN FAIRLY UNCOMMON FOR THE PAST FEW HOURS. THE TAFS WILL HANDLE THE BRUNT OF THE SNOW (OVER THE COURSE OF THE NEXT 4-8 HOURS) WITH PREVAILING IFR VISIBILITIES AND LOW-END MVFR CEILINGS IN A TEMPO. MVFR CEILINGS ARE EXPECTED TO BE THE RULE LATER IN THE DAY...WITH LOW LEVEL MOISTURE FORECAST TO INCREASE...EVEN AS THE STEADY PRECIPITATION COMES TO AN END. SNOW SHOWERS LATER IN THE DAY MAY STILL BE CAPABLE OF BRIEF IFR VISIBILITIES...BUT IN GENERAL MVFR CONDITIONS ARE EXPECTED. AS SNOW TAPERS OFF DURING THE EVENING AND INTO THE OVERNIGHT HOURS...VISIBILITIES SHOULD GO VFR...WITH SOME LOW CEILINGS (GENERALLY MVFR) STILL REMAINING IN PLACE. HOWEVER...SOME SCATTERING OF THE CLOUD DECK WILL BE EXPECTED. OUTLOOK...MVFR CONDITIONS WILL CONTINUE TO BE POSSIBLE ON SUNDAY. MVFR TO IFR CONDITIONS ARE EXPECTED AGAIN ON MONDAY AND MONDAY NIGHT. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR OHZ026-034- 035-042>046-051>056-060>065-070>074-077>082-088. KY...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR KYZ089>100. IN...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR INZ050-058- 059-066-073>075-080. && $$ SYNOPSIS...HICKMAN NEAR TERM...CONIGLIO/HICKMAN SHORT TERM...HICKMAN LONG TERM...NOVAK AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
429 PM EST SAT FEB 2 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 423 PM EST SAT FEB 2 2013 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT DEEP UPR TROF OVER E-CENTRL NAMERICA DOWNSTREAM OF HI AMPLITUDE UPR RDG ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW ALF PASSED OVER THE UPR LKS THIS MRNG...BUT SHRTWV RDG/DNVA/DEEP LYR QVECTOR CNVGC IN ITS WAKE IS DOMINATING THE CWA THIS AFTN. ALTHOUGH LES CONTINUES IN THE NW WIND SN BELTS WITH H85 TEMPS NOT FAR FM -20C...THESE NEGATIVE DYNAMICS THAT ARE DROPPING INVRN BASE TOWARD H9 PER RUC ANALYSIS AND ARRIVAL OF LLVL ACYC FLOW AS WELL AS VERY DRY AIRMASS UPWIND OF LK SUP /12Z PWAT AT INL AND YPL WAS ABOUT 0.06 INCH/ ARE LIMITING THE INTENSITY/COVERAGE OF THE BANDS. FARTHER UPSTREAM... THERE ARE TWO SHRTWVS DIGGING SEWD THRU THE NW FLOW ALF. THE FIRST IS DIVING INTO THE NRN PLAINS. THE SECOND DISTURBANCE WHICH WL HAVE A MORE DIRECT IMPACT IS HEADING SSEWD THRU NRN MANITOBA. LATE TODAY/TNGT...AS SFC RDG AXIS IN THE WAKE OF DEPARTING SHRTWV PASSES SEWD THRU THE FA THIS EVNG...WINDS WL BACK STEADILY TO THE SW THRU THIS EVNG. LINGERING LES BANDS WL BE SHIFTING STEADILY WITH THE FLOW...AND IN CONCERT WITH MORE ACYC FLOW/LOWERING INVRN BASE LIMIT ANY ADDITIONAL SN ACCUMS. MEANWHILE...FIRST UPSTREAM SHRTWV IS PROGGED TO HEAD SEWD THRU THE UPR MS RIVER VALLEY. SINCE THE SHARPER DPVA/DEEP LYR QVECTOR CNVGC/DEEPER MSTR WL PASS TO THE SW OF THE WI BORDER...EXPECT THE BULK OF ANY ACCOMPANYING PCPN TO REMAIN IN WI EVEN THOUGH SOME CLDS WL ARRIVE. AREA OF SHARPER DPVA/QVECTOR CNVGC/ MSTR ASSOCIATED WITH 2ND SHRTWV WL ARRIVE AFT MIDNGT. DRYNESS OF AIRMASS WL LIMIT ANY LARGER SCALE PCPN...BUT ARRIVAL OF ACCOMPANYING LO PRES TROF OVER THE NW ZNS LATE/WSHFT TO THE W-NW THAT WL BRING ABOUT SOME LK ENHANCEMENT IN THE PRESENCE OF H85 TEMPS ARND -18C/ DEEP MSTR JUSTIFIES GOING CATEGORICAL POPS IN THAT AREA. SINCE 12Z NAM FCST PROFILE FOR CMX SHOWS UVV MAX WITHIN DENDRITIC SN GROWTH LYR...THERE MAY BE A PERIOD OF HEAVY SHSN JUST BEFORE 12Z THAT COINCIDES WITH THE ARRIVAL OF THE TROF/SHARPER LLVL CNVGC. AS FOR TEMPS...EXPECT READINGS TO FALL OFF RATHER QUICKLY THIS EVNG TOWARD THE LOWER END OF GUIDANCE BUT THEN FALL ONLY SLOWLY OR PERHAPS RISE WITH ARRIVAL OF MORE CLDS. SUN...2ND SHRTWV IS FCST TO TRACK THRU LK SUP/ADJOINING ONTARIO ON SUN MRNG...WITH ATTENDANT SFC TROF/WSHFT TO THE NW SWINGING ACRS THE ERN CWA IN THE 15Z-18Z TIME. IN ITS WAKE...DNVA/LARGER SCALE QVECTOR DVGC WL DOMINATE...DROPPING INVRN BASE OVER THE W TO 4-5K FT BY 18Z BUT NOT OVER THE E UNTIL NEAR 00Z. SINCE THE INCOMING AIRMASS WL BE QUITE CHILLY WITH H85 TEMPS PROGGED TO FALL AS LO AS -23C OVER THE W LATE IN THE DAY...RATHER SHORT FETCH LENGTH OVER THE W HALF OF LK SUP...SHORTENED EVEN FURTHER BY RECENT ICE BUILDUP ALONG THE W SHORE OF THE CWA...WL LIMIT LK MODERATION. WITH THE DGZ CONFINED TO ONLY A SHALLOW NEAR SFC LYR...EXPECT SMALL SN FLAKE SIZE AND RATHER LIMITED SN ACCUMS AFT THE PASSAGE OF THE TROF/HEAVIER SN BAND EARLY. EVEN THOUGH H925 NW WINDS IN THE WAKE OF THE TROF ARE FCST TO BE NO HIER THAN ABOUT 25KT WHICH WOULD TEND TO LIMIT THE MAGNITUDE OF ANY BLSN...PRESENCE OF SN COVERED ICE OFFSHORE WL LIKELY ENHANCE THE VSBY RESTRICTION. FOR THE W...OPTED TO GO WITH AN LES ADVY FOR ONTONAGON/HOUGHTON/KEWEENAW COUNTIES BEGINNING AT 09Z AND EXTENDING THRU THE DAY. FOR AREAS E OF MQT...EXPECT A PERIOD OF HEAVIER SHSN TO DVLP IN THE MRNG WITH PASSAGE OF TROF AND THEN MORE SUSTAINED HEAVIER SHSN IN PREVAILING NW FLOW THRU THE AFTN. FCST PROFILE SHOW DEEPER DGZ MAINTAINED BY MORE LK MOISTENING WL CAUSE BIGGER SN FLAKES/HIER SN ACCUMS THAN OVER THE W. FOR ALGER/NRN SCHOOLCRAFT/ LUCE COUNTIES...OPTED TO BEGIN LONG DURATION LES WRNG AT 15Z. OVER THE CENTRAL ZNS WITH DOWNSLOPE FLOW/LIMITED ABSOLUTE MSTR...THERE WL BE NOTHING MORE THAN ISOLD-SCT -SHSN ASSOCIATED WITH THE TROF PASSAGE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 423 PM EST SAT FEB 2 2013 UPPER TROUGH AXIS CENTERED OVER NORTHER HUDSON BAY FORECAST TO OPEN UP AND LIFT FARTHER NORTH INTO NUNAVUT CANADA. RESULT IS TROUGH AND COLD AIR OVER GREAT LAKES TO BEGIN THE PERIOD EASES MID-LATE WEEK. BY NEXT WEEKEND...HEIGHTS AND TEMPS ARE ON THE RISE OVER MUCH OF EASTERN CONUS OUT AHEAD OF DEEPENING TROUGH OVER SOUTHWEST CONUS. MEDIUM RANGE MODELS /GFS/ECMWF/GEM-NH/UKMET/ IN GREAT AGREEMENT WITH LARGER SCALE PATTERN THROUGH NEXT WEEK...LEADING TO HIGHER THAN NORMAL CONFIDENCE FOR MUCH OF THE FORECAST. NORTHWEST FLOW ALOFT KEEPS COLD AIR IN OVER THE AREA THROUGH AT LEAST MIDWEEK. INITIAL CONCERN WILL BE NEXT ROUND OF MODERATE TO HEAVY LK EFFECT SNOWS THAT KICK OFF ON SUNDAY. NW FLOW AREAS IN LINE TO SEE THE MOST SNOW. IN THE WEST...SHORTER OVER-WATER FETCH RESULTS IN LOWER INVERSION HEIGHTS AROUND 5KFT AND LESS LAKE INDUCED CAPE. TEMPS MAINLY BLO -20C IN THE LK EFFECT CONVECTIVE LAYER POINT TO NOT AS MUCH FOR SNOW ACCUMULATION BUT GIVEN SMALL SNOWFLAKE SIZE THE VSBY WILL BE POOR IN ANY SNOW SHOWERS. AS MENTIONED IN SHORT TERM DISCUSSION...BLSN/DRSN MAY NOW BE MORE OF ISSUE ALONG SHORE DUE TO THE ICE BUILDUP IN LAST FEW DAYS. BTWN THE VSBY ISSUES AND MODERATE SNOW...WILL CARRY LK EFFECT SNOW ADVY THROUGH DAYBREAK ON MONDAY. HEAVIER SNOW EXPECTED OVER THE EAST...ESPECIALLY FROM MUNISING EAST ACROSS THE FAVORED SNOWBELTS NORTH OF M-28 TO THE NORTH OF NEWBERRY. UNLIKE THE WEST...MUCH LONGER OVER-WATER FETCH RESULTS IN INVERSION HEIGHTS TO 8KFT AND LAKE INDUCED CAPES NEAR 700J/KG. ALSO UNLIKE THE WEST...MORE OF THE DGZ IS WITHIN THE LAKE EFFECT LAYER...LEADING TO HIGHER SLR/S OVER 25:1. KEY FOR THE HEAVY SNOW WILL BE WHERE STRONGEST CONVERGENCE SETS UP SUNDAY NIGHT THROUGH MONDAY MORNING. UNFORTUNATELY STILL SOME DESCREPANCY HERE...WITH REGIONAL-GEM AND GFS OVER LUCE COUNTY WHILE NAM AND NCEP WRF-ARW ALONG WITH LOCAL WRF ARE FARTHER WEST MORE INTO ALGER COUNTY. NOTICED THAT NAM SFC CONVERGENCE IS FARTHER WEST COMPARED TO H95 CONVERGENCE. SFC CONVERGENCE PEGGED WESTERN EDGE OF LK EFFECT TODAY FAIRLY WELL...SO FOLLOWED THAT IDEA FOR POPS. KEPT HIGHER SNOW IN THE SNOWBELTS OF EASTERN ALGER COUNTY THROUGH NORTHERN LUCE COUNTY. FOR THOSE AREAS SNOW AMOUNTS OF 5-7 INCHES ARE EXPECTED SUNDAY NIGHT WITH ADDITIONAL 3-6 INCHES ON MONDAY. CERTAINLY POSSIBLE THAT MODERATE SNOW AMOUNTS MAY FALL AS FAR WEST AS AU TRAIN/MUNISING AS WELL...ESPECIALLY IF THE FARTHER WEST CONVERGENCE CAMP OF MODELS IS CORRECT. LK EFFECT SNOW WARNING STARTS UP ON SUNDAY AND WILL JUST RUN IT ALL THE WAY THROUGH MONDAY AS BLYR WINDS DO NOT REALLY BACK MORE WNW UNTIL LATER MONDAY AFTN. LINGERED HIGHER POPS FOR SNOW SHOWERS EAST OF MUNISING ON MONDAY NIGHT...BUT INVERSIONS LOWERING BLO 5KFT SHOULD BEGIN TO TAKE TOLL ON INTENSITY OF LK EFFECT. AWAY FROM THE LK EFFECT COLD WILL BE MAIN STORY. LGT WINDS AND DRY AIRMASS LEADS TO POTENTIAL FOR MIN TEMPS WELL BLO ZERO SUNDAY NIGHT. MAX TEMPS MONDAY LIKELY ONLY STRUGGLE INTO LOWER TEENS ABOVE ZERO. ONCE THE LK EFFECT SUBSIDES LATER MONDAY NIGHT...ATTN IS ON APPROACHING CLIPPER SHORTWAVE/PV ANAMOLY DIVING IN FROM NORTHERN PLAINS. NAM APPEARS FARTHER NORTH WITH TRACK OF WAVE...RESULTING IN STRONGER MOISTURE TRANSPORT/WARM AIR ADVECTION INTO NORTHERN WI/UPR MICHIGAN. GFS/GEM-NH/ECMWF FARTHER SOUTH WITH ALL THE FORCING AND ONLY GLANCE UPR MICHIGAN WITH SYSTEM SNOW. SEEMS THAT SHORTWAVE WOULD TEND TO DIG FARTHER SOUTH GIVEN DOWNSTREAM TROUGHING OVER THE EASTERN CONUS. MODELS HAVE BASICALLY BEEN CONSISTENT IN KEEPING SYSTEM TO THE SOUTH AND THOUGH 12Z GFS DID JOG NORTH SOME...THE 12Z ECMWF IS KEEPING TRACK TO THE SOUTH. EVEN WITH A DIRECT HIT FROM SYSTEM...LACK OF AVAILABLE MOISTURE WITH PWATS JUST SHY OF NORMAL AND H7 MIXING RATIOS NOT EVEN 2G/KG...WOULD KEEP SNOW AMOUNTS TO AN INCH OR TWO. BIGGER IMPACT IS DOWNSTREAM OF LK MICHIGAN IN EASTERN CWA...WHERE OVER-WATER INSTABILITY WOULD BE PRESENT WITH H85 TEMPS BLO -10C COMBINING WITH THE LARGER SCALE LIFT FROM SYSTEM MAYBE COULD HELP GENERATE ADVY LEVEL SNOWS. NEXT CLIPPER MOVING THROUGH WEDNESDAY NIGHT INTO THURSDAY SEEMS TO HAVE BETTER SHOT AT IMPACTING MUCH OF UPR MICHIGAN WITH SNOW. THOUGH SFC LOW TRACKS WELL TO SOUTH ACROSS IA AND SOUTHERN WI...H85 TROUGH IS FARTHER NORTH AND ALLOWS TEMP/MOISTURE ADVECTION INTO UPR MICHIGAN. TEND TO THINK HEAVIER QPF WILL END UP SOUTH OF CWA THOUGH AS RIGHT ENTRANCE REGION OF JET PLACES BETTER UPR DIVERGENCE SOUTH OF UPR MICHIGAN. EVEN SO...WIDESPREAD SNOW OF 1-3"/2-4" COULD OCCUR ACROSS CWA INTO THURSDAY. MAYBE SOME LK EFFECT ON THE BACKSIDE OF THE TROUGH BUT TEMPS ARE MODERATING BY THIS TIME AS H85 TEMPS ARE ONLY DOWN TO AROUND -13C. CONTINUING MODERATION ON FRIDAY AND SATURDAY RESULTING IN LK EFFECT TO SHUT DOWN AND HIGH TEMPS BOTH FRIDAY AND SATURDAY POSSIBLY EXCEEDING 30 DEGREES. NEXT TROUGH AND SNOW CHANCES ARRIVES LATER IN THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1221 PM EST SAT FEB 2 2013 CMX...EXPECT IFR/MVFR CONDITIONS IN -SHSN THRU THIS AFTN TO GIVE WAY TO VFR CONDITIONS WITH WSHFT TO THE SW THIS EVNG. AS ANOTHER UPR DISTURBANCE/SFC TROF APRCH OVERNGT...MORE -SN/MVFR CONDITIONS WL PREDOMINATE AFT 06Z. AS THE TROF PASSES TOWARD 12Z...EXPECT A PERIOD OF HEAVIER SHSN WITH LIFR CONDITIONS FOR AT LEAST A COUPLE OF HRS. FOLLOWING THE PASSAGE OF THE TROF/HEAVIER SHSN...IFR CONDITIONS WL THEN LINGER THE REST OF THE TAF PERIOD WITH LES/SMALL SN FLAKES/SOME BLSN EFFECTIVELY REDUCING VSBY. IWD...VFR CONDITIONS THRU THIS EVNG WL GIVE WAY TO SOME -SN/MVFR CONDITIONS LATE TNGT WITH APRCH OF DISTURBANCE/LO PRES TROF. IFR CONDITIONS WL THEN ACCOMPANY THE PASSAGE OF THE TROF AND THEN PERSIST AS LES SETS UP IN THE WAKE OF THE PASSAGE WITH WSHFT TO NW. SAW...EXPECT VFR CONDITIONS TO PREDOMINATE THRU TNGT WITH DOWNSLOPE NW FLOW BACKING TO THE WSW AHEAD OF APRCHG LO PRES TROF. SOME MVFR CIGS MAY IMPACT THIS SITE FOLLOWING THE PASSAGE OF THE TROF ON SUN MRNG AS VERY COLD AIR SURGES BACK INTO THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 423 PM EST SAT FEB 2 2013 WSW WINDS UP TO 25 KTS WILL VEER NW LATE TONIGHT/SUN MORNING IN THE WAKE OF A LO PRES TROF PASSAGE. AS ANOTHER VERY COLD AIRMASS POURS OVER THE LAKE AND NW WINDS INCREASE UP TO 30 KTS...EXPECT HEAVY FREEZING SPRAY TO DEVELOP OVER THE W AND CENTRAL ON SUN AND TO CONTINUE OVER MUCH OF THE LAKE THROUGH MONDAY. WINDS DIMINISH BLO 25 KTS BY TUESDAY. EXPECT A COUPLE OF CLIPPER SYSTEMS TO MOVE ACROSS THE UPPER GREAT LAKES THE REST OF THE WEEK...BUT WINDS SHOULD STAY MAINLY BLO 30 KTS. GRADUALLY WARMING TEMPERATURES WILL END THE POTENTIAL FOR FREEZING SPRAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY FROM 4 AM SUNDAY TO 7 AM EST MONDAY FOR MIZ001>003-084. LAKE EFFECT SNOW WARNING FROM 10 AM SUNDAY TO 7 PM EST MONDAY FOR MIZ006-007-085. LAKE SUPERIOR... HEAVY FREEZING SPRAY WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR LSZ249>251-266-267. HEAVY FREEZING SPRAY WARNING FROM 1 PM SUNDAY TO 7 AM EST MONDAY FOR LSZ248-265. HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 7 AM EST MONDAY FOR LSZ244-245-264. HEAVY FREEZING SPRAY WARNING FROM 1 AM EST /MIDNIGHT CST/ SUNDAY TO 1 AM EST /MIDNIGHT CST/ MONDAY FOR LSZ241>243-263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
317 PM CST SAT FEB 2 2013 .SHORT TERM... MAIN ISSUE WILL BE SNOW AND BLOWING SNOW LATE THIS AFTERNOON AND EVENING. SAT LOOP AND 500MB ANALYSIS SHOW THE CLIPPER SHORTWAVE MOVING THROUGH CENTRAL ND...WITH A FAIR AMOUNT OF SNOW ACROSS MUCH OF THE VALLEY. BEST RADAR RETURNS HAVE BEEN FROM VALLEY CITY TOWARDS FARGO...AND WEBCAMS SHOW SOME LIGHT ACCUMULATIONS. A FEW OBS SITES THIS MORNING WENT DOWN TO 1/4SM VIS BRIEFLY AS HEAVIER SNOW BANDS MOVED OVER THEM...BUT QUICKLY IMPROVED WHEN SNOW BECAME LESS INTENSE. OF GREATER IMPACT TO THE PUBLIC WILL BE THE WINDS ON THE BACKSIDE OF THE SFC LOW CURRENTLY NEAR THE JAMESTOWN AREA. WINDS HAVE SHIFTED TO THE NORTHWEST BEHIND THE LOW AND MANY HAVE INCREASED INTO THE 25 TO 35 KT RANGE. THERE HAS BEEN QUITE A BIT OF BLOWING SNOW AND NEAR ZERO VISIBILITIES IN THE WESTERN PART OF THE STATE. TRAJECTORY OF THE SFC LOW AND THE HIGH MSLP FALL/RISE COUPLET WOULD HAVE THE HIGHEST WINDS MAINLY IMPACTING OUR WESTERN AND SOUTHERN COUNTIES. RAP HAS HAD A DECENT HANDLE ON THE SFC WINDS IN THE WEST SO HAVE FOLLOWED IT FAIRLY CLOSELY. MODEL SOUNDINGS SHOW THE BEST CHANCES FOR GOOD MIXING TO THE SFC WILL BE MAINLY OVER THE FAR SOUTHWEST COUNTIES. WINDS HAVE ALREADY SHIFTED TO THE WEST IN WESTERN BENSON COUNTY AND SHOULD START BLOWING IN THE NEXT HOUR OR TWO. RADAR ESTIMATES SHOW A COUPLE OF INCHES OF FRESH ACCUMULATION FROM KDVL DOWN TOWARDS THE SOUTHERN VALLEY. WITH FRESH SNOW...BLOWING SNOW AND REDUCED VIS WILL BE A PROBLEM. WITH THE WORST OF THE SFC WINDS JUST MOVING BY TO OUR SOUTH AND WEST...FOR NOW JUST INCLUDED THE HIGHER TERRAIN OF THE DEVILS LAKE DOWN TO RANSOM/SARGENT COUNTIES...ALONG WITH RICHLAND AND WILKEN COUNTIES. WILL HAVE TO WATCH FAR WESTERN CASS COUNTY FOR BLOWING SNOW BUT FOR NOW WILL LEAVE FARGO OUT OF IT AS IT SEEMS THAT THE WORST WINDS WILL MISS THEM. WINDS SHOULD START TO COME DOWN BY MID EVENING IN THE DEVILS LAKE BASIN AND AROUND 06Z FURTHER SOUTH. THE SHORTWAVE WILL MOVE QUICKLY OFF TO THE EAST TONIGHT...WITH WINDS TAPERING OFF AND A WEAK SFC HIGH MOVING IN BY MORNING. DEPENDING ON THE AMOUNT OF CLEARING BY MORNING...THERE COULD AGAIN BE TEMPERATURES IN THE TEENS BELOW ZERO AND WIND CHILL VALUES APPROACHING ADVISORY CRITERIA IN THE NORTH BY THE EARLY MORNING HOURS. HOWEVER...WITH THE ONGOING WSW FOR BLOWING SNOW AND THE UNCERTAINTY OF CLOUDS WILL LEAVE OUT FOR NOW. ANOTHER WEAK SHORTWAVE WILL BEGIN TO DIG INTO THE WESTERN DAKOTAS SUNDAY...WITH ANOTHER WEAK SFC LOW DEVELOPING TO THE SOUTHWEST OF THE CWA. MODELS HAVE BEEN TRENDING FURTHER SOUTH AND WEST SO KEPT HIGHEST POPS FROM THE DEVILS LAKE BASIN TOWARDS THE LAKES COUNTRY FOR SUNDAY INTO SUNDAY NIGHT. TIGHT TEMP GRADIENT REMAINS OVER THE NORTHERN PLAINS BUT THINK THAT ARCTIC AIR WILL REMAIN IN PLACE OVER MOST OF THE REGION SO KEPT HIGHS MAINLY IN THE SINGLE DIGITS WITH SOME TEENS IN THE WEST. THERE SHOULD BE A REINFORCING SURGE OF COLD AIR SUNDAY NIGHT WHICH WILL HELP KEEP LOWS MOSTLY BELOW ZERO. ANOTHER WEAK CLIPPER SYSTEM WILL BEGIN TO MOVE INTO SOUTHERN CANADA BY MONDAY...BRINGING ANOTHER ROUND OF PRECIP INTO OUR NORTHWESTERN CWA BY MONDAY AFTERNOON. TEMPS SHOULD REMAIN BELOW AVERAGE. THE PARADE OF WEAK SHORTWAVES WILL CONTINUE INTO MONDAY NIGHT AND TUESDAY. THERE ARE SOME DIFFERENCES IN THE TRACK OF THE MONDAY NIGHT/TUESDAY LOW...BUT OVERALL THIS SYSTEM SEEMS A BIT FURTHER NORTH AND EAST THAN THE PREVIOUS FEW SYSTEMS. STILL PRETTY UNCERTAIN SO INCLUDED JUST HIGH CHANCE POPS FOR NOW BUT WILL PROBABLY NEED TO BUMP UP. THERE SHOULD BE A DECENT AMOUNT OF WARM AIR ADVECTION AND SOME WARMER AIR GETTING INTO AT LEAST THE SOUTHWESTERN CWA. STARTED BRINGING LOWS IN THE TEENS INTO THE WEST MONDAY NIGHT AND HIGHS UP INTO THE TEENS TO 20S FOR TUESDAY. .LONG TERM (TUE NIGHT-SAT)... NORTHWEST FLOW ALOFT WILL GRADUALLY TRANSITION MORE TO A ZONAL FLOW AND THEN BY LATE IN THE PERIOD...BRIEF RIDGING FOLLOWED BY SOUTHWEST FLOW. MODELS SEEM PRETTY CONSISTENT IN DEPICTING ANOTHER SHOT OF LIGHT SNOW MAINLY ACROSS THE NORTHERN FA ON WED/WED NIGHT. THURSDAY AND FRIDAY SHOULD BE QUIET WITH MILDER AIR MOVING BACK INTO THE AREA. STILL LOOKING TO TURN A LITTLE MORE ACTIVE AGAIN BY SATURDAY IN THE SOUTHWEST FLOW WITH A COLORADO LOW TAKING SHAPE. AT THIS POINT THIS SYSTEM WOULD AFFECT THE SOUTHERN FA MORE THAN THE NORTH BUT IT IS A LONG WAYS OFF YET. WILL HAVE TO SEE WHAT FUTURE MODEL RUNS HAVE IN STORE FOR THIS SYSTEM. && .AVIATION... THE BAND OF LIGHT SNOW LOOKS LIKE IT WILL MOVE THROUGH THE AREA QUICKLY THIS AFTERNOON ONLY BRINGING AN HOUR OR SO OF LOWER VSBYS BEFORE SHIFTING OFF TO THE SOUTHEAST. THE MAIN QUESTION FOR THE TAFS IS WHETHER THE GUSTY WINDS WHICH ARE CURRENTLY WEST OF THE FA MAKE IT INTO THE RED RIVER VALLEY TONIGHT AND CAUSE ANY REDUCTION TO VBSY DUE TO BLOWING SNOW. BROUGHT WINDS UP AND INSERTED SOME BLOWING SNOW WITH THE WORST CONDITIONS AT KFAR. WINDS SHOULD DIE DOWN LATER IN THE EVENING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR NDZ006- 007-014-015-024-026-028-054. WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ038- 049-052-053. MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ029. && $$ JR/GODON
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1006 AM CST SAT FEB 2 2013 .DISCUSSION... MADE SOME MINOR TWEAKS TO POPS/WX FOR SNOW AS THE CLIPPER SYSTEM MOVES THROUGH THE AREA. OBS SHOW SOME -SN HAS STARTED IN THE SOUTHWESTERN CWA...ALTHOUGH NOTHING ACCUMULATING SO FAR. NAM AND RAP SHOW THE BEST PRECIP CHANCES WILL BE WITH THE MAIN SHORTWAVE COMING THROUGH THIS AFTERNOON...WITH THE BEST CHANCES FOR 1 TO 2 INCHES OF SNOW STRETCHING SOUTHEASTWARD FROM NORTH CENTRAL ND TOWARDS LAKES COUNTRY. MOST OF THE HIGHER WINDS THIS AFTERNOON WILL BE TO OUR WEST...BUT THE FAR WESTERN TIER OF COUNTIES COULD GET FAIRLY BREEZY LATE THIS AFTERNOON AND EVENING BEHIND THE SFC LOW. INCLUDED A PATCHY BLOWING SNOW MENTION FOR A FEW HOURS...NO HEADLINES BUT WILL KEEP AN EYE ON THINGS. ADJUSTED TEMPS A BIT AS READINGS HAVE BEEN A BIT SLOW TO WARM IN THE BITTERLY COLD NORTHEASTERN COUNTIES...BUT KEPT HIGHS IN THE SINGLE DIGITS TO NEAR 20 IN THE FAR SOUTHWEST. && .AVIATION... VFR/MVFR CEILINGS WILL INCREASE FROM WEST TO EAST THROUGH THE DAY AS A LOW PRESSURE SYSTEM MOVES ACROSS THE REGION. SOME LIGHT SNOW IS POSSIBLE FOR AIRFIELDS ALONG AND WEST OF THE VALLEY AFTER 15 UTC. SNOW SHOULD BE LIGHT...BUT SOME REDUCTIONS IN VISIBILITY LESS THAN ONE MILE ARE POSSIBLE. LIGHT SOUTH-SOUTHWEST WIND THROUGH THE DAY WILL INCREASE AND SHIFT TO THE NORTHWEST THIS EVENING AND OVERNIGHT. && .PREV DISCUSSION... /ISSUED 400 AM CST SAT FEB 2 2013/ SHORT TERM...TODAY THROUGH MONDAY NIGHT MAIN FORECAST CHALLENGES INCLUDE LIGHT SNOW CHANCES AND TEMPERATURES. GFS/NAM/ECMWF/GEM IN GOOD AGREEMENT AND WILL USE A BLENDED SOLUTION FOR THIS FORECAST PACKAGE. FOR TODAY...A CLIPPER SYSTEM IN NORTHWEST FLOW ALOFT WILL MOVE ACROSS THE NORTHERN PLAINS. MOST OF THE FORECAST AREA WILL REMAIN ON THE COOL SIDE OF THE SYSTEM AS THE SURFACE LOW TRACKS FROM CENTRAL SASKATCHEWAN TO NORTHEAST SD. AFTERNOON HIGHS WILL MAINLY BE IN THE SINGLE DIGITS TO LOW TEENS ABOVE ZERO...BUT AREAS WEST OF A LINE FROM DEVILS LAKE TO VALLEY CITY TO LISBON MAY CLIMB INTO THE LOW 20S. CANADIAN RADARS SHOW LIGHT SNOW SOUTH AND EAST OF THE SURFACE LOW AND THIS BAND IS EXPECTED TO MOVE SOUTHEASTWARD THROUGH THE DAY...MAINLY IMPACTING EASTERN ND INTO WEST CENTRAL MN. SLOWED THE TIMING OF THE HIGHEST POPS AS LATEST RAP OUTPUT KEEPS MAJORITY OF PRECIPITATION OUT OF THE FORECAST AREA UNTIL AFTER 15 UTC. TOTAL ACCUMULATIONS THROUGH TONIGHT WILL GENERALLY BE AN INCH OR LESS. REMAINING SNOW SHOWERS EXPECTED TO MOVE EAST OF THE FORECAST AREA BY MIDNIGHT WITH DECREASING CLOUD COVER FROM WEST TO EAST. SUNDAY MORNING LOWS EXPECTED IN THE 0 TO 10 BELOW RANGE...BUT WILL BE HIGHLY DEPENDENT ON CLOUD COVER. ANOTHER WEAK CLIPPER DROPS SOUTH ON SUNDAY...BRINGING A NARROW BAND OF LIGHT SNOW FROM CENTRAL ND INTO SOUTHWEST MN. STRONG SURFACE HIGH WILL MOVE INTO THE NORTHERN VALLEY BY 06 UTC MONDAY AND THIS WILL LIMIT NORTHWARD EXTENT OF PRECIPITATION. MODEL TRENDS PLACE SNOW FARTHER SOUTH...SO ADJUSTED HIGHEST POPS SOUTH OF A LINE FROM DEVILS LAKE TO HILLSBORO TO PARK RAPIDS. ACCUMULATIONS EXPECTED TO BE EVEN LESS THAN TODAY...GENERALLY A HALF INCH OF LESS. SKIES WILL BE MOSTLY CLOUDY AND TEMPERATURES WILL BE NEAR OR SLIGHTLY COOLER THAN TODAY IN THE WAKE OF TODAY/S SYSTEM. THE PARADE OF CLIPPERS CONTINUE INTO EARLY NEXT WEEK WITH A THIRD WAVE ON MONDAY. THE TRACK OF THE SURFACE LOW IS A BIT FARTHER NORTH...SO EXPECT GREATER SPATIAL COVERAGE OF ACCUMULATING SNOWFALL. STRONG MID-LEVEL WARM AIR ADVECTION WILL COMBINE UPPER JET DYNAMICS TO PRODUCE A COUPLE INCHES OF SNOW ACROSS THE NORTHERN VALLEY INTO NORTHWEST MN. WITH TRACK OF THE LOW AND ALIGNMENT OF THE BAROCLINIC AXIS...TEMPERATURES WILL BE A BIT WARMER WITH AFTERNOON HIGHS MAINLY IN THE TEENS ABOVE ZERO. MORNING LOWS WILL CONTINUE TO BE DEPENDENT ON CLOUD COVER...BUT NOT EXPECTING MUCH DAY TO DAY CHANGE WITH THE COOLEST READINGS ACROSS THE LAKE OF THE WOODS REGION. LONG TERM...TUESDAY THROUGH FRIDAY NIGHT NW FLOW ALOFT WILL SLOWLY TRANSITION TO A MORE ZONAL/SW FLOW ALOFT BY NEXT WEEKEND. THIS WILL MEAN GRADUALLY WARMING TEMPS ABOVE NORMAL WITH MINIMAL CHANCES FOR PRECIP THROUGH SAT. THERE IS THE POTENTIAL FOR SOME LINGERING LIGHT SNOW EARLY TUE IN THE EAST...AND IN THE NORTH ON WED WITH SOME WAA. OTHERWISE...EXPECT A DRY EXTENDED WITH A WARMING TREND. THERE ARE SOME HINTS AT A POTENTIAL STORM BY LATE SAT INTO SUNDAY...WITH THE MAIN POTENTIAL IMPACTS AT THIS TIME POSSIBLE IN THE SOUTHERN FORECAST AREA. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ JR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1235 PM EST SAT FEB 2 2013 .SYNOPSIS... A CLIPPER SYSTEM WILL TRACK EAST ACROSS THE GREAT LAKES AND OHIO VALLEY THROUGH TONIGHT. A WEAK UPPER LEVEL WEATHER DISTURBANCE WILL AFFECT THE REGION ON SUNDAY. HIGH PRESSURE WILL BUILD BRIEFLY INTO THE OHIO VALLEY SUNDAY NIGHT. THE HIGH WILL MOVE EAST ON MONDAY AS ANOTHER CLIPPER SYSTEM QUICKLY MOVES TOWARD THE OHIO VALLEY FROM THE NORTHWEST. && .NEAR TERM /THROUGH TONIGHT/... SNOW HAS OVERSPREAD THE FORECAST AREA. NAM AND RAP MODELS HAVE GOOD REPRESENTATIONS OF THE AREA OF SNOW. ACCUMULATIONS HAVE BEEN UP TO AN INCH IN SOUTHWEST COUNTIES. THE BEST ISENTROPIC LIFT WILL OCCUR AHEAD OF THE WEAK SFC LOW AND FRONT. THUS...MUCH OF THE SNOW ACCUMULATION WILL OCCUR DURING THE DAYLIGHT HOURS. THE SNOW WILL TAPER OFF FROM WEST TO EAST THIS EVENING AS THE CLIPPER MOVES OFF TO THE EAST. USING A BLEND OF MODEL QPF AND SNOW TO LIQUID RATIOS BASED ON TEMPERATURE...IT STILL LOOKS LIKE A GOOD 2 TO 3 INCH SNOW EVENT AREA WIDE WITH ISOLATED AMOUNTS NEAR 4 INCHES. A WINTER WEATHER ADVISORY WILL REMAIN IN EFFECT THROUGH TONIGHT. WITH LOW LEVEL WAA...HIGHS TODAY SHOULD RANGE FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. IN CAA BEHIND THE DEPARTING CLIPPER...OVERNIGHT LOWS SHOULD RANGE FROM THE MID TEENS NORTHWEST TO THE LOWER 20S SOUTHEAST. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... OUR REGION WILL REMAIN UNDER A NORTHWEST FLOW PATTERN ALOFT THROUGH THE SHORT TERM PERIOD. THIS PATTERN WILL ALLOW SEVERAL WEATHER SYSTEMS TO AFFECT THE AREA. ON SUNDAY...A SHEARED OUT WEAK UPR LVL WX DISTURBANCE WILL PASS ACRS THE REGION. THIS FEATURE WILL KEEP SKIES MAINLY CLOUDY ALONG WITH A CHANCE OF SNOW SHOWERS. THE WEAK DISTURBANCE WILL EXIT THE AREA BY SUNDAY EVENING. DESPITE SURFACE HIGH PRESSURE BRIEFLY BUILDING INTO THE OHIO VALLEY...CLOUDS WILL CONTINUE TO SPILL SOUTHEAST FROM THE NEXT CLIPPER SYSTEM WHICH WILL LIMIT ANY OPPORTUNITY TO CLEAR OUT. FOR MONDAY INTO MONDAY NIGHT...MODELS ALL INDICATE THAT A CLIPPER SYSTEM WILL TRACK SOUTHEAST THROUGH THE OHIO VALLEY. AM CONFIDENT ENOUGH AT THIS POINT TO RAISE POPS TO LIKELY FOR MONDAY AFTERNOON INTO MONDAY NIGHT. THERE CONTINUES TO BE STRENGTH ISSUES WITH THE LOW AND ITS ASSOCIATED WAA/LOW LEVEL JET WHICH WILL ULTIMATELY DICTATE PCPN TYPE AND SNOW ACCUMULATIONS. AT THIS POINT IT LOOKS LIKE MUCH OF THE AREA NORTH OF THE OHIO RIVER WILL SEE SNOW WHILE RAIN MAY MIX WITH SNOW ALONG AND SOUTH OF THE RIVER MONDAY AFTERNOON INTO MONDAY EVENING UNTIL CAA CHANGES THE PCPN TO ALL SNOW BEFORE TAPERING OFF LATE. AGAIN...WE SHOULD SEE SOME ACCUMULATIONS BUT AMOUNTS ARE STILL UNCERTAIN AT THIS POINT DUE TO REASONS JUST MENTIONED. WILL SPELL THIS OUT IN THE HWO PRODUCT. LITTLE RESPITE IS EXPECTED TUESDAY INTO TUESDAY NIGHT AS ANOTHER CLIPPER SYSTEM WILL BE ON THE HEELS OF THE MONDAY/MONDAY NIGHT SYSTEM. THERE CONTINUES TO BE PLACEMENT ISSUES WITH THIS FEATURE IN HOW FAR SOUTH IT WILL DIG. HAVE KEPT POPS IN THE CHANCE CATEGORY UNTIL MODELS RESOLVE THIS DILEMMA. PCPN WILL BE IN THE FORM OF SNOW NORTH WITH RAIN/SNOW POSSIBLE SOUTH. AS FOR TEMPERATURES...THEY WILL BE HARD TO PINPOINT GIVEN SNOW COVER AND SURFACE LOW PLACEMENT WITH THE UPCOMING CLIPPER SYSTEMS WHICH WILL RESULT IN SFC WAA AHEAD OF THE LOW CENTER. MAINLY USED A BLEND OF THE GFS/ECMWF SURFACE TEMPERATURES ALONG WITH CLIMATOLOGICAL THICKNESS SCHEMES. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... HIGH PRESSURE WILL BE IN PLACE ACROSS THE AREA FOR WEDNESDAY AND WILL MOVE EAST OF THE FA ON THURSDAY. WITH SOUTHERLY FLOW ON THURSDAY TEMPERATURES WILL RANGE FROM THE MIDDLE 30S TO THE MIDDLE 40S ACROSS THE REGION. PRECIPITATION WILL BEGIN TO MOVE INTO THE FA THURSDAY EVENING AND BECOME MORE WIDESPREAD ACROSS THE AREA THURSDAY NIGHT AS A COLD FRONT APPROACHES AND MOVES THROUGH THE REGION. PRECIPITATION WILL TAPER OFF ACROSS THE FA DURING THE MORNING HOURS ON FRIDAY AND HIGH PRESSURE WILL WORK BACK INTO THE REGION FRIDAY AFTERNOON. && .AVIATION /18Z SATURDAY THROUGH WEDNESDAY/... SNOW WILL CONTINUE TO IMPACT AVIATION. VISIBILITIES AS LOW AS IFR WILL PERSIST THIS AFTERNOON UNTIL WEAK LOW PRESSURE AND BANDS OF SNOW MOVE EAST. SINCE MODELS HAVE LOW LEVEL MOISTURE REMAINING IN PLACE...MVFR CEILINGS SHOULD LINGER THROUGH THE END OF THE TAF PERIOD. WINDS WILL GUST CLOSE TO 20 KNOTS OUT OF THE SOUTH TO SOUTHWEST THIS AFTERNOON. LOOK FOR A SHIFT IN DIRECTION TO WEST TONIGHT BEHIND THE WEAK LOW. MORE SNOW SHOWERS ARE EXPECTED ON SUNDAY DUE TO A WEAK DISTURBANCE IN THE JET STREAM. OUTLOOK...MVFR TO IFR CONDITIONS ARE EXPECTED AGAIN ON MONDAY AND MONDAY NIGHT. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR OHZ026-034- 035-042>046-051>056-060>065-070>074-077>082-088. KY...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR KYZ089>100. IN...WINTER WEATHER ADVISORY UNTIL 7 AM EST SUNDAY FOR INZ050-058- 059-066-073>075-080. && $$ SYNOPSIS...HICKMAN NEAR TERM...CONIGLIO/HICKMAN SHORT TERM...HICKMAN LONG TERM...NOVAK AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
336 PM CST SAT FEB 2 2013 .DISCUSSION... VERY WEAK FRONTAL BOUNDARY SHOULD MAKE ITS WAY TO THE I-10 CORRIDOR AROUND MIDNIGHT THEN OFFSHORE BEFORE SUNRISE. MAY SEE SOME AREAS OF FOG CLOSER TO THE COAST BEFORE FROPA. OFFSHORE WINDS WILL BE SHORT LIVED AS SE FLOW WILL RESUME BY EVENING WHEN SFC HIGH PUSHES OFF TO THE EAST. THESE ONSHORE WINDS WILL TRANSPORT SOME 1.3"-1.5" PW`S BACK INTO THE AREA ON MONDAY COINCIDING WITH SOME WEAK IMPULSES MOVING OVERHEAD. ANTICIPATE SOME SCT SHRA TO DEVELOP ACROSS THE REGION WITH THE HIGHEST CHANCES PROBABLY E OF I-45. APPEARS ANOTHER REALLY WEAK FRONT WILL APPROACH THE COAST ON TUES. LOOKS LIKE IT`LL STALL JUST INLAND. GFS/ECMWF IN FAIR AGREEMENT SHOWING UPPER TROF (CURRENTLY SEEN ON W/V IMAGERY OFF THE NRN CALIFORNIA COAST) DROPPING SOUTH THEN EAST ACROSS S TX TUES NIGHT & WED. THIS SHOULD PROVIDE OUR NEXT SHOT OF RAINFALL...ESPECIALLY THE SRN HALF OF SE TX AND OFFSHORE. NUDGED POPS UPWARD DURING THIS TIME PERIOD - AND WILL PROBABLY NEED TO CONTINUE DOING SO IF FUTURE MODEL RUNS ARE CONSISTENT. THE NEXT WRN TROF MAKES ITS WAY EWD NEXT WEEKEND. STILL SOME TIMING/PATTERN DIFFERENCES BUT MEDIUM RANGE GUESSES BRING THE NEXT COLD FRONT AND ASSOCIATED PRECIP INTO THE REGION NEXT SUNDAY...BUT MAY SEE SOME SCT ACTIVITY IN ADVANCE ON SAT. 47 && .MARINE... THE WEAK COLD FRONT SHOULD WORK ITS WAY OFF THE COAST BY AROUND 6 AM SUNDAY. DO NOT THINK SEA FOG WILL FORM AS THE SURFACE DEWPOINTS SHOULD STAY BELOW THE WATER TEMPERATURES. OTHERWISE...ONSHORE WINDS WILL QUICKLY RETURN AHEAD OF THE NEXT FRONT TO MOVE OFF THE COAST EARLY TUESDAY. MODERATE ONSHORE FLOW MAY DEVELOP BY AROUND MID WEEK AS THE MODELS ARE SHOWING AN INCREASED PRESSURE GRADIENT. 40 && .147 PM AVIATION... VFR CONDITIONS WILL PERSIST THROUGH THIS EVENING. A WEAK FRONT IS FORECAST TO PUSH THROUGH TO THE COAST BY AROUND SUNRISE SUNDAY. THERE IS A CHANCE THAT FOG WILL DEVELOP AHEAD OF THE FRONT... ESPECIALLY FROM KCXO TO THE COAST. THE LATEST MODELS ARE A BIT FASTER WITH THE FRONT PUSHING OUT THE FOG THAN THE 18Z FORECAST INDICATES. WILL COMPARE THE LATEST RAP MODEL FORECASTS AND MAKE ADJUSTMENTS ON THE 21Z UPDATE IF NEEDED. 40 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 44 70 50 72 53 / 0 0 10 30 20 HOUSTON (IAH) 49 72 52 74 56 / 0 0 0 30 30 GALVESTON (GLS) 56 68 60 70 60 / 0 0 0 20 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
147 PM CST SAT FEB 2 2013 .DISCUSSION... SEE THE 18Z/21Z AVIATION DISCUSSION BELOW. 40 && .AVIATION... VFR CONDITIONS WILL PERSIST THROUGH THIS EVENING. A WEAK FRONT IS FORECAST TO PUSH THROUGH TO THE COAST BY AROUND SUNRISE SUNDAY. THERE IS A CHANCE THAT FOG WILL DEVELOP AHEAD OF THE FRONT... ESPECIALLY FROM KCXO TO THE COAST. THE LATEST MODELS ARE A BIT FASTER WITH THE FRONT PUSHING OUT THE FOG THAN THE 18Z FORECAST INDICATES. WILL COMPARE THE LATEST RAP MODEL FORECASTS AND MAKE ADJUSTMENTS ON THE 21Z UPDATE IF NEEDED. 40 && .PREV DISCUSSION... /ISSUED 952 AM CST SAT FEB 2 2013/ DISCUSSION... SHOULD SEE A NICE WARM UP THIS AFTN WITH HIGHS TOPPING OUT IN THE 70S. CURRENT FCST IS IN GOOD SHAPE. JUST SOME INSIGNIFICANT TWEAKS TO THE GRIDS BASED ON LATEST TRENDS FOR THE MORNING UPDATE. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 74 43 69 50 72 / 0 10 0 20 30 HOUSTON (IAH) 75 48 71 51 74 / 0 10 0 10 30 GALVESTON (GLS) 71 55 68 57 68 / 0 10 0 10 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...47 AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
230 PM CST SAT FEB 2 2013 .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT 230 PM CST SAT FEB 2 2013 THE TRAIN OF NORTHWEST FLOW SHORTWAVES CONTINUES. TONIGHT...AN UPPER LEVEL SHORTWAVE CURRENTLY MIGRATING ACROSS THE NORTHERN PLAINS WILL SLIDE ACROSS THE REGION. SOME WEAK 2-D FRONTOGENETIC RESPONSE AT 900 MB WITH THE FEATURE...ALONG WITH WEAK QG CONVERGENCE THROUGH THE 850-300 MB LAYER. SOME ISENTROPIC UPGLIDE ON THE 280-290 K SFCS THIS EVENING...MOST OF WHICH EXITS EAST AFTER 06Z. GOOD DENDRITIC ZONE GROWTH //DGZ// REGION THOUGH...FROM 700 MB TO THE SFC FOR MUCH OF TONIGHT...WHEN THE SNOW WILL BE FALLING. RATIOS OF 30:1 ARE REASONABLE GIVEN THIS SCENARIO. THIS SHORTWAVE DOESN/T LOOK TO BE AS PERKY AS THE ONE LAST NIGHT...AND WILL HAVE EVEN LESS QPF. SO...EXPECT LESS SNOWFALL AMOUNTS. SOME CONCERN THAT IT MIGHT MISS A BULK OF THE FORECAST AREA...WITH LATEST HRRR AND ARW MESO MODELS SUGGESTING THAT MOST OF THE ACCUMULATING SNOWS WILL MOVE INTO CENTRAL IA. THE NAM12/GFS40 SHOW SOMETHING SIMILAR...BUT STILL PAINT SOME LIGHT SNOW INTO NORTHERN WI. WILL TREND THE HIGHER POPS TO THE SOUTH. SHORTWAVE NUMBER 4 SPINS ACROSS IA SUNDAY NIGHT...EXITING OVER THE OH RIVER VALLEY ON MONDAY. FRONTOGENETIC RESPONSE IS MUCH STRONGER WITH THIS FEATURE...AS IS THE QG CONVERGENCE AND ISENTROPIC UPGLIDE. THE DGZ ISN/T AS DEEP AS EXPECTED FOR TONIGHT...AND WITH PREVIOUS SHORTWAVES. THIS WILL HELP KEEP RATIOS CLOSER TO 15/20:1. NAM/GFS/ECMWF ALL COMPARABLE WITH PRODUCING A RELATIVELY NARROW BAND OF QPF...FOCUSED ON THE FRONTOGENETIC REGION...AND CENTER IT ROUGHLY AROUND A ROCHESTER TO RICHLAND CENTER LINE. SEE THE POTENTIAL FOR SOME ADVISORY AMOUNTS IN THE BAND...3 TO 4 INCHES POSSIBLE. NOT ENOUGH CONFIDENCE TO ISSUE AT THIS TIME...BUT SCENARIO WILL CONTINUE TO EVALUATED. COME TUE...SURPRISE...SHORTWAVE NUMBER 5 DROPS FROM CANADA TO ACROSS NORTHERN PARTS OF MN/WI. GFS AND NAM BOTH AGREE ON A SLIGHTLY MORE NORTHERLY TRACK TO THIS WEATHER FEATURE...BRINGING THE BETTER SNOW CHANCES TO NORTHERN PARTS OF THE FORECAST AREA. ANOTHER INCH...PERHAPS TWO...LOOKS LIKELY. .LONG TERM...WEDNESDAY THROUGH SATURDAY 230 PM CST SAT FEB 2 2013 VERY ACTIVE NORTHWEST FLOW CONTINUES THROUGH THE END OF THE WORK WEEK. HOWEVER...WE MIGHT SEE THE CABOOSE WED NIGHT/THU MORNING...WITH THE EC AND GFS SPINNING A PIECE OF UPPER LEVEL ENERGY ACROSS THE REGION WED NIGHT...REINFORCED BY A STRONGER SHORTWAVE THU MORNING. SOME QUESTION ON PTYPES WITH THIS EVENT AS WARMER AIR WILL BE RETURNING...AND A POSSIBLE LOSS OF ICE IN THE CLOUD AS THE SYSTEM STARTS TO EXIT EAST. WON/T GET OVERLY DETAILED WITH GRIDS AT THE MOMENT...BUT THE POTENTIAL FOR MIXED WINTER PCPN WILL HAVE TO BE MONITORED. THE GFS AND EC FAVOR BRINGING A LOW PRESSURE SYSTEM OUT OF THE SOUTH FOR THE WEEKEND...DRIVING IT ACROSS THE REGION SAT/SUN. DIFFERENCING IN STRENGTH AND POSITION...AND SOME VARIANCE IN TIMING. BOTH WOULD LAY DOWN A DEFORMATION BAND OF SNOW...BUT ALSO LIKELY HAVE SOME RAIN/WINTER MIX ON ITS SOUTHEAST SIDE. THIS SYSTEM ALSO LOOKS TO PACK MUCH MORE OF A PUNCH THAN THE PARADE OF SHORTWAVES MOVING DOWN FROM THE NORTHWEST. && .AVIATION... 1146 AM CST SAT FEB 2 2013 THIS AFTERNOON...MID CLOUDS /8 TO 10K/ WILL BE ON THE INCREASE AND THE LIGHT SURFACE WINDS WILL GRADUALLY SHIFT FROM THE NORTHWEST TO THE SOUTH AS YET ANOTHER SHORTWAVE MOVES THROUGH THE REGION. TONIGHT...THE SHORTWAVE TROUGH WILL MOVE THROUGH THE REGION. AT THIS TIME IS LOOKS LIKE THE BEST LIFT WILL OCCUR BETWEEN 03.02Z AND 03.07Z AT KRST AND BETWEEN 03.04Z AND 03.08Z AT KLSE. IN ADDITION...THIS LIFT IS CO-LOCATED WITH A 8K FOOT DENDRITIC GROWTH ZONE. THIS WILL RESULT IN ANOTHER ROUND OF SNOW FOR THE AREA. VISIBILITIES WILL QUICKLY DROP TO 1 1/2 MILES DURING THIS TIME PERIOD AND THE CEILINGS WILL BECOME MVFR. SNOW AMOUNTS WILL BE AROUND AN INCH. SUNDAY...SUBSIDENCE WILL CAUSE THE SKIES TO GRADUALLY CLEAR BETWEEN 03.12Z AND 03.16Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 230 PM CST SAT FEB 2 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RIECK LONG TERM....RIECK AVIATION.....BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1153 AM CST SAT FEB 2 2013 .UPDATE...VIS SAT SHOWS SKIES CLEARING ACROSS NORTHERN PORTIONS OF THE FORECAST AREA...WITH THE BACK EDGE OF THE LOW LEVEL CLOUDS WORKING ITS WAY SOUTH. UPDATED SKY GRIDS TO REFLECT LATEST TRENDS. BOTH RAP AND NAM BUFKIT MODEL SOUNDINGS REFLECT SUCH A TREND...AND HAVE THE LOW LEVELS OF THE MODEL SOUNDINGS DRYING OUT. FURTHER...THE MODEL RH FIELDS...ESPECIALLY AT 850 HPA...SHOW A DECREASING RH TREND. FOR LATER IN THE DAY...NAM12 AND RAP BOTH SHOW AN INCREASE IN MID- AND UPPER-LEVEL RH...THAT COINCIDES WITH CLOUDS SEEN ACROSS EASTERN MN INTO SOUTHWESTERN WISCONSIN. THESE CLOUDS ARE EXPECTED TO CONTINUE TO WORK THEIR WAY INTO SOUTH CENTRAL AND SOUTHEAST WI THIS AFTERNOON. TEMPERATURES WERE UPDATED TO REFLECT LATEST TRENDS. GIVEN THE BREAK IN THE CLOUDS THAT WASNT EXACTLY ANTICIPATED IN THE FCST...NOW CONCERNED WITH THE IMPACT LESS SKY COVER WILL HAVE ON HIGH TEMPS. HOWEVER...THERE IS LIGHT COLD AIR ADVECTION ONGOING ON THE LOW LEVELS. TEMPERATURE FCST IS TRENDING OK SO FAR...SO WILL WAIT A BIT AND WILL EVALUATE MORE OF SHORT TERM GUIDANCE AND ADJUST IF NEEDED. ET && .AVIATION/18Z TAFS/...VFR CONDITIONS EXPECTED ACROSS TAF SITES THIS AFTERNOON AND EVENING. WINDS WILL BACK FROM NORTH THIS AFTERNOON TO SOUTHWEST BY 06Z SUNDAY...REMAINING LIGHT. LOW CLOUDS WILL MOVE SOUTH OF THE AREA EARLY THIS AFTERNOON...WITH MID TO HIGH CLOUDS GRADUALLY FILLING INTO THE AREA THROUGH THE AFTERNOON AND EVENING. MVFR CEILINGS WITH VERY LIGHT SNOW IS EXPECTED BETWEEN 06Z AND 12Z SUNDAY AT MADISON...AND 09Z AND 15Z SUNDAY AT THE EASTERN TAF SITES. THE VERY LIGHT SNOW MAY BE ON AND OFF...AND ANY ACCUMULATIONS WOULD BE 0.1 TO 0.2 INCHES AT BEST. FLUFFY AND POWDERY SNOW IS EXPECTED...BUT STILL WOULD BE AN IMPACT ON RUNWAYS. WINDS VEER NORTHWEST BETWEEN 12Z AND 15Z SUNDAY AND BECOME GUSTY THROUGH THE DAY. GUSTS TO 23 KNOTS ARE EXPECTED. WOOD && .PREV DISCUSSION... /ISSUED 344 AM CST SAT FEB 2 2013/ SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE - MEDIUM. ENHANCED FORCING FROM WARM AIR ADVECTION SLIDING OFF TO THE SOUTHEAST EARLY THIS MORNING RESULTING IN DIMINISHING ACCUMULATING SNOW. HOWEVER...AREAS OF VERY LIGHT SNOW LAGGING BEHIND ASSOCIATED WITH WEAK 85H TROUGH WHICH PASSES THRU SRN WI MAY RESULT IN AN ADDITIONAL DUSTING BTWN 12Z AND 15Z. CLOUDS SHOULD THIN LATER TODAY ALLOWING SOME SUNSHINE TO RETURN FOR A TIME. HOWEVER CLEARING WL BE SHORT-LIVED AS ANOTHER WEAKER PUSH OF WARM AIR ADVECTION WL SWEEP THROUGH WI TNGT. WATER VAPOR IMAGERY CLEARLY SHOWS UPSTREAM SHORT WAVE TROUGH OVER SRN SASKATCHEWAN MOVING SOUTHEAST. APPEARS SHORT TERM GUIDANCE HAVING DIFFICULTY WITH THIS WAVE BUT IF IT MAINTAINS ITS CURRENT SOUTHEAST COURSE...WOULD AFFECT PORTIONS OF SOUTHEAST WI OVERNIGHT. POSSIBLE HINTS FROM Q-VECTOR CONVERGENCE WHERE AXIS OF -5 TO -10 UNITS MOVES ACROSS SRN WI FROM LATE EVE THRU THE OVERNIGHT. LITTLE FRONTOGENETICAL FORCING...BUT SOME ISENTROPIC OMEGA SHOWING UP ON 280 THETA SFC OVERNIGHT. CONDENSATION PRESSURE DEFICITS DECREASE TO LESS THAN 10 MB FOR A 3-6 HOUR PD. FOR NOW BUMPED UP TO LIKELY WORDING ACROSS MORE OF THE NORTH AND WEST...WITH HIGHER CHC ELSEWHERE. DEEP DENTRITIC GROWTH ZONE WOULD BE TAPPED BY WEAK FORCING SO SNOW LIQUID RATIOS COULD AGAIN BE HIGHER THAN EXPECTED 25 TO 1. FOR NOW WL KEEP LIGHT ACCUMULATIONS LESS THAN AN INCH IN THE NORTH AND WEST. SUNDAY...FORECAST CONFIDENCE HIGH. STRONG SUBSIDENCE BEHIND THE EXITING 500MB SHORTWAVE EXPECTED TO BRING SOME SUNSHINE TO SOUTHERN WI DURING THE DAY ON SUNDAY. ONLY EXPECTING LOWER TO MID TEENS FOR HIGH TEMPS...ALONG WITH COLD WIND CHILLS WITH WEAK COLD AIR ADVECTION ON BRISK NORTHWEST WINDS. SUNDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM TO HIGH. THE NEXT SHORTWAVE WILL BRING ANOTHER ROUND OF SNOW TO SOUTHERN WI SUNDAY NIGHT. INCREASED POPS TO THE DEFINITE CATEGORY AS IMPRESSIVE 700 TO 850MB FRONTOGENESIS AND 700MB OMEGA MOVE ACROSS SOUTHERN WISCONSIN. THIS WILL PROBABLY BE AN EVENT WHERE A NARROW LINE GETS A SWATH OF 3 INCHES OF SNOW AND AREAS AROUND IT GET AN INCH. MANY MODELS FOCUS THE HIGHEST QPF SWATH ACROSS FAR SOUTHERN WI AND NORTHERN IL. THE CANADIAN HAS THIS SHIFTED SLIGHTLY NORTHWARD. USED A CONSENSUS FOR SNOW RATIOS IN THE 17 TO 19:1 RANGE. THE 06Z NAM CAME IN WITH A LATER ARRIVAL/END TIME OF THIS EVENT BY ALMOST 6 HOURS. FAVORED ECMWF TIMING FOR NOW. SNOW WILL TAPER OFF MONDAY MORNING...ALTHOUGH FLURRIES MAY LINGER INTO THE AFTERNOON WITH CYCLONIC FLOW ALOFT STICKING AROUND. WEAK COLD ADVECTION WITH THE SURFACE HIGH MOVING OVERHEAD WILL KEEP TEMPS COOL ONCE AGAIN...SO HIGHS IN THE UPPER TEENS TO AROUND 20 EXPECTED. LONG TERM... TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH. A STRONGER SHORTWAVE TROUGH/VORT MAX ON THE RIGHT ENTRANCE REGION OF A 110 KNOT UPPER JET WILL ROLL THROUGH THE UPPER MIDWEST ON TUESDAY. THE ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL TRACK ACROSS MN AND WI AS IT WEAKENS AS THE 500MB VORT MAX SHEARS OUT. IT IS BECOMING MORE LIKELY THAT LIGHT SNOW WILL SPREAD ACROSS SOUTHERN AND CENTRAL WI EARLY TUE MORNING THROUGH TUE AFTERNOON. SNOW AMOUNTS SHOULD BE ABOUT 1 TO 2 INCHES. TUESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM. THE FLOW ALOFT WILL TRANSITION TO MORE ZONAL WED AND THU. QUIET WEATHER EXPECTED ON WEDNESDAY. THEN TEMPS PROGGED TO WARM INTO THE LOWER 30S ON THU JUST AHEAD OF THE NEXT SHORTWAVE BY THU AFTERNOON. THE 850MB 0 DEGREE LINE IS FORECAST TO REACH THE WI/IL BORDER...BUT THE TEMP PROFILE IN FORECAST SOUNDINGS REMAINS BELOW ZERO EXCEPT AT THE SURFACE. THIS WOULD IMPLY A CHANCE FOR SOME SNOW TO CHANGE OVER TO RAIN ACROSS SOUTHERN WI LATER THU AFTERNOON IF THE SURFACE WARMS JUST ENOUGH. KEPT A RAIN/SNOW MIX THERE AND SNOW IN THE NORTHERN FORECAST AREA. HIGH PRESSURE AND QUIET WEATHER WITH HIGHS IN THE LOWER 30S WILL BE IN PLACE FOR FRIDAY. MODELS ARE ADVERTISING A WET SYSTEM APPROACHING WI OVER THE WEEKEND. AVIATION/12Z TAFS/...VARYING VSBYS THIS MRNG BTWN MVFR AND VFR AND -SN DIMINISHES ACROSS SRN WI. MOSTLY VFR CONDITIONS EXPCD THIS AFTN BEFORE ANOTHER BATCH OF -SN AFFECTS SRN WI TNGT. PERIOD OF -SN WILL BE BRIEFER THAN THIS MRNG WITH LESS ACCUMULATION. MARINE...TIGHTENING PRESSURE GRADIENT BEHIND PASSING WEAK LOW PRESSURE TROUGH MAY RESULT IN WIND GUSTS TO SMALL CRAFT ADVY LEVELS ON SUNDAY...IN ICE FREE AREAS. THE GUSTY NORTHWEST WINDS WOULD LINGER INTO SUNDAY EVENING BEFORE DIMINISHING. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...ET/WOOD TODAY/TONIGHT AND AVIATION/MARINE...MBK SUNDAY THROUGH FRIDAY...MRC