Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/23/14


SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
937 AM PST FRI FEB 21 2014 ...UPDATED AVIATION SECTION... .SYNOPSIS... HIGH PRESSURE WILL BRING MOSTLY CLEAR SKIES AND ABOVE NORMAL MAXIMUM TEMPERATURES THROUGH SATURDAY. THE MARINE LAYER WILL RETURN SUNDAY AND BRING COOLER TEMPERATURES INTO EARLY NEXT WEEK. IT IS GROWING MORE AND MORE LIKELY THAT IT WILL BE WET FROM MID WEEK ON. && .SHORT TERM (TODAY-MON)...A DENSE FOG FIELD DEVELOPED OVER THE SAN PEDRO CHANNEL THIS MORNING AND WAS EXPANDING OVER THE CHANNEL WHILE SURGING NORTH OVER THE SANTA MONICA BASIN AT THIS TIME. THE LOW LEVEL PROFILER IS INOP AT LAX THIS MORNING AND ESTIMATE THE TOPS USING THE ABC LONG BEACH WEB CAM AT 500 FEET OR LESS. HRRR INDICATED LIGHT SOUTH WINDS OVER THE SANTA MONICA BASIN THROUGH EARLY AFTERNOON AND THE DENSE FOG MAY CONTINUE NORTH AND SURGE ONTO THE MALIBU COAST LATE THIS MORNING. HAVE ISSUED AN UPDATE FOR THE LOS ANGELES COUNTY COAST AND SANTA CATALINA ISLAND OTHERWISE NO CHANGES. THE FOLLOWING DISCUSSION IS FROM THE PREVIOUS SHIFT... A COUPLE OF NICE DAYS ON TAP TODAY AND SATURDAY AS THE AREA SITS UNDER MOSTLY CLEAR SKIES. DRY SW FLOW WILL BE OVERHEAD AS A RIDGE WILL SIT TO THE WEST OF THE STATE. GOOD OFFSHORE FLOW THIS MORNING (WITH SOME RESULTANT SUB ADVISORY 15 TO 25 MPH WINDS THROUGH AND BELOW THE CANYONS) WILL MAKE TODAY THE WARMEST WITH MANY VLY MAX TEMPS IN THE LOW TO MID 80S. ON SATURDAY ONSHORE TRENDS COULD BRING SOME LOW CLOUDS TO THE LONG BEACH AREA IN THE MORNING AND WILL COOL THE COASTS BUT THE INTERIOR TEMPS WILL BE PRETTY UNCHANGED. STRONGER ONSHORE FLOW ON SUNDAY AND A WEAK EDDY WILL BRING LOW CLOUDS TO LA/VTA/SRN SBA COASTS AND LOCALLY INTO THE COASTAL VLYS. THIS WILL CAUSE A GOOD COOL DOWN FOR THE COASTS AND VLY. THE MTNS AND INTERIOR SECTIONS WILL NOT SEE MUCH CHANGE IN TEMPS. MONDAY WILL BE A NEAR CARBON COPY (NOTHING LIKE AN OUT OF DATE REFERENCE) OF SUNDAY. MORNING LOW CLOUDS FOR THE COASTS AND VLYS SOUTH OF POINT CONCEPTION...OTHERWISE MOSTLY CLEAR SKIES WITH NEAR NORMAL MAX TEMPS. .LONG TERM (TUE-THU)... THE XTND FCST IS WHERE ALL THE ACTION IS. ON TUESDAY THE RIDGE MOVES EASTWARD. ONSHORE FLOW INCREASES. MID AND HIGH LEVEL CLOUDS WILL STREAM IN AND BLANKET THE AREAS. A DEEP MARINE LAYER SHOULD BE LIFT UP ACROSS THE CSTS AND INTO THE VLYS AS WELL. SO LOOK FOR A CLOUDIER COOLER DAY. CONTINUED CLOUDY ON WEDNESDAY WITH A BIG MIX OF LOW MID AND HIGH CLOUDS. BY THE AFTERNOON A FRONT WILL APPROACH THE AREA. TIMING IS NOT A SURE THING AS THE FRONT AND TROF WILL HAVE TO FIGHT THE DEPARTING RIDGE AND MAY WELL BE SLOWED DOWN. THE CANADIAN MDL IS THE FASTEST THE EC JUST A TOUCH SLOWER AND THE GFS IS NOTICEABLY SLOWER. ALL THREE MDLS BRING RAIN TO THE CENTRAL COAST WED EVENING SO LIKELY POPS SEEM JUSTIFIED EVEN THOUGH ITS STILL ALONG WAYS AWAY. A CHANCE OF RAIN ELSE WHERE AS THE FRONT MOVES THROUGH THE AREA OVERNIGHT AND INTO THURSDAY MORNING. HGTS ARE PRETTY HIGH AND SNOW LEVELS SHOULD STAY ABOVE 6500 FEET. CURRENT MDLS RUNS SHOW A SMALL POP UP RIDGE FOR THURSDAY AND A MUCH LESS CHANCE OF RAIN. THE RIDGE SHOULD BE VERY DIRTY FROM THE VANGUARD OF CLOUDS STREAMING AHEAD OF THE NEXT BIGGER SYSTEM SO SKIES WILL LIKELY BE MOSTLY CLOUDY. STILL KEEP SLGT CHC/CHC POPS GOING FOR THE DAY BECAUSE THE MDLS CAN EASILY MISS THE FCST BY 12 HOURS AND THERE COULD BE LINGERING SHOWERS OR EARLY ARRIVING SHOWERS. THE BIG NEWS CONTINUES TO BE NEXT FRIDAY AND SATURDAY WITH ALL MDLS CONTINUING TO FCST A SUBSTANTIAL STORM. YOU WILL WANT TO STAY TUNED FOR THE LATEST UPDATES FOR THIS STORM AS IT DEVELOPS. && .AVIATION...21/1730Z HIGH CONFIDENCE IN VFR CONDITIONS AT MOST SITES FOR THE NEXT 24 HOURS DUE TO WEAK OFFSHORE FLOW. SOME DENSE FOG AND STRATUS HAS FORMED ALONG THE LA COAST THIS MORNING...BUT NOT EXPECTING IT TO REACH LAX OR LGB TODAY. THERE IS A 40 PERCENT CHANCE THAT LGB WILL HAVE IFR CIGS OR LOWER SATURDAY MORNING. KLAX...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH ABOUT 11Z SATURDAY MORNING. 20 PERCENT CHANCE OF IFR OR LOWER CIGS AFTER 12Z. KBUR...HIGH CONFIDENCE IN VFR CONDITIONS FOR THE NEXT 24 HOURS. && .LOX WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY (SEE LAXMWWLOX). && $$ PUBLIC...30/RORKE AVIATION...SUKUP SYNOPSIS...SETO WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
855 AM PST FRI FEB 21 2014 .SYNOPSIS... HIGH PRESSURE WILL BRING MOSTLY CLEAR SKIES AND ABOVE NORMAL MAXIMUM TEMPERATURES THROUGH SATURDAY. THE MARINE LAYER WILL RETURN SUNDAY AND BRING COOLER TEMPERATURES INTO EARLY NEXT WEEK. IT IS GROWING MORE AND MORE LIKELY THAT IT WILL BE WET FROM MID WEEK ON. && .SHORT TERM (TODAY-MON)...A DENSE FOG FIELD DEVELOPED OVER THE SAN PEDRO CHANNEL THIS MORNING AND WAS EXPANDING OVER THE CHANNEL WHILE SURGING NORTH OVER THE SANTA MONICA BASIN AT THIS TIME. THE LOW LEVEL PROFILER IS INOP AT LAX THIS MORNING AND ESTIMATE THE TOPS USING THE ABC LONG BEACH WEB CAM AT 500 FEET OR LESS. HRRR INDICATED LIGHT SOUTH WINDS OVER THE SANTA MONICA BASIN THROUGH EARLY AFTERNOON AND THE DENSE FOG MAY CONTINUE NORTH AND SURGE ONTO THE MALIBU COAST LATE THIS MORNING. HAVE ISSUED AN UPDATE FOR THE LOS ANGELES COUNTY COAST AND SANTA CATALINA ISLAND OTHERWISE NO CHANGES. THE FOLLOWING DISCUSSION IS FROM THE PREVIOUS SHIFT... A COUPLE OF NICE DAYS ON TAP TODAY AND SATURDAY AS THE AREA SITS UNDER MOSTLY CLEAR SKIES. DRY SW FLOW WILL BE OVERHEAD AS A RIDGE WILL SIT TO THE WEST OF THE STATE. GOOD OFFSHORE FLOW THIS MORNING (WITH SOME RESULTANT SUB ADVISORY 15 TO 25 MPH WINDS THROUGH AND BELOW THE CANYONS) WILL MAKE TODAY THE WARMEST WITH MANY VLY MAX TEMPS IN THE LOW TO MID 80S. ON SATURDAY ONSHORE TRENDS COULD BRING SOME LOW CLOUDS TO THE LONG BEACH AREA IN THE MORNING AND WILL COOL THE COASTS BUT THE INTERIOR TEMPS WILL BE PRETTY UNCHANGED. STRONGER ONSHORE FLOW ON SUNDAY AND A WEAK EDDY WILL BRING LOW CLOUDS TO LA/VTA/SRN SBA COASTS AND LOCALLY INTO THE COASTAL VLYS. THIS WILL CAUSE A GOOD COOL DOWN FOR THE COASTS AND VLY. THE MTNS AND INTERIOR SECTIONS WILL NOT SEE MUCH CHANGE IN TEMPS. MONDAY WILL BE A NEAR CARBON COPY (NOTHING LIKE AN OUT OF DATE REFERENCE) OF SUNDAY. MORNING LOW CLOUDS FOR THE COASTS AND VLYS SOUTH OF POINT CONCEPTION...OTHERWISE MOSTLY CLEAR SKIES WITH NEAR NORMAL MAX TEMPS. .LONG TERM (TUE-THU)... THE XTND FCST IS WHERE ALL THE ACTION IS. ON TUESDAY THE RIDGE MOVES EASTWARD. ONSHORE FLOW INCREASES. MID AND HIGH LEVEL CLOUDS WILL STREAM IN AND BLANKET THE AREAS. A DEEP MARINE LAYER SHOULD BE LIFT UP ACROSS THE CSTS AND INTO THE VLYS AS WELL. SO LOOK FOR A CLOUDIER COOLER DAY. CONTINUED CLOUDY ON WEDNESDAY WITH A BIG MIX OF LOW MID AND HIGH CLOUDS. BY THE AFTERNOON A FRONT WILL APPROACH THE AREA. TIMING IS NOT A SURE THING AS THE FRONT AND TROF WILL HAVE TO FIGHT THE DEPARTING RIDGE AND MAY WELL BE SLOWED DOWN. THE CANADIAN MDL IS THE FASTEST THE EC JUST A TOUCH SLOWER AND THE GFS IS NOTICEABLY SLOWER. ALL THREE MDLS BRING RAIN TO THE CENTRAL COAST WED EVENING SO LIKELY POPS SEEM JUSTIFIED EVEN THOUGH ITS STILL ALONG WAYS AWAY. A CHANCE OF RAIN ELSE WHERE AS THE FRONT MOVES THROUGH THE AREA OVERNIGHT AND INTO THURSDAY MORNING. HGTS ARE PRETTY HIGH AND SNOW LEVELS SHOULD STAY ABOVE 6500 FEET. CURRENT MDLS RUNS SHOW A SMALL POP UP RIDGE FOR THURSDAY AND A MUCH LESS CHANCE OF RAIN. THE RIDGE SHOULD BE VERY DIRTY FROM THE VANGUARD OF CLOUDS STREAMING AHEAD OF THE NEXT BIGGER SYSTEM SO SKIES WILL LIKELY BE MOSTLY CLOUDY. STILL KEEP SLGT CHC/CHC POPS GOING FOR THE DAY BECAUSE THE MDLS CAN EASILY MISS THE FCST BY 12 HOURS AND THERE COULD BE LINGERING SHOWERS OR EARLY ARRIVING SHOWERS. THE BIG NEWS CONTINUES TO BE NEXT FRIDAY AND SATURDAY WITH ALL MDLS CONTINUING TO FCST A SUBSTANTIAL STORM. YOU WILL WANT TO STAY TUNED FOR THE LATEST UPDATES FOR THIS STORM AS IT DEVELOPS. && .AVIATION... 21/1200Z HI CONFIDENCE IN THE 12Z TAFS WITH VFR CONDITIONS EXPECTED AT ALL THE AIRFIELDS FOR AT LEAST THE NEXT 18 HOURS. MARINE STRATUS COULD DEVELOP OVER THE L.A. COAST AFTER 08Z SATURDAY. KLAX...HI CONFIDENCE IN CAVU TAF THROUGH 08Z. THERE IS A 40 PERCENT CHANCE OF LIFR CIGS AFTER 08Z. KBUR...HI CONFIDENCE IN CAVU TAF. && .LOX WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY (SEE LAXMWWLOX). && $$ PUBLIC...30/RORKE AVIATION...KAPLAN SYNOPSIS...SETO WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1005 AM MST FRI FEB 21 2014 .UPDATE...WINDS HAVE PICKED UP SOONER THAN EXPECTED AND HAVE ALREADY UPDATED FOR THIS. ALSO LOWERED POPS AND SNOW AMOUNTS FOR THE MOUNTAINS TODAY. WEB CAMERAS SHOWING THE SNOW IS CONFINED TO THE HIGHER MOUNTAINS AND EXPECT THAT TREND TO CONTINUE THROUGH TODAY. HIGHS LOOK ON TRACK...MAY NEED TO EVENTUALLY LOWER TEMPERATURES A COUPLE OF DEGREES IF ANY ADJUSTMENTS ARE NEEDED. && .AVIATION...STRONG WEST WINDS HAVE DEVELOPED AND WILL CONTINUE UNTIL AROUND 00-01Z. GUSTS TO 40 TO 45 KNOTS WILL BE POSSIBLE AT KDEN AND KAPA WITH GUSTS TO AROUND 50 KNOTS AT KBJC. WEST WINDS WILL TURN SOUTHWEST DURING THE EVENING HOURS. && .PREV DISCUSSION... /ISSUED 535 AM MST FRI FEB 21 2014/ UPDATE... SHORT TERM...WINDS HAVE DROPPED OFF TO BLO WARNING LEVELS EVEN AT THE NORMAL WINDY SPOTS SO WILL CANCEL THE HI WIND WARNING EARLY. PREV DISCUSSION... /ISSUED 344 AM MST FRI FEB 21 2014/ SHORT TERM...NW FLOW ALOFT WILL REMAIN OVER THE AREA TODAY THRU TONIGHT. DECENT WIND EVENT OCCURRED LATE LAST EVENING INTO THE EARLY MORNING HOURS IN AND NEAR THE FOOTHILLS OF BOULDER AND JEFFERSON COUNTIES AS GUSTS RANGED FROM 70-90 MPH. THE LAST FEW HOURS WINDS HAVE DECREASED WITH GUSTS MAINLY IN THE 50-60 MPH RANGE WITH A FEW GUSTS TO 70 MPH AT TIMES. OVERALL MTN WAVE SHOULD BREAKDOWN BY 12Z WITH THREAT OF HIGH WINDS GRADUALLY BY 9 AM IF NOT SOONER. HOWEVER IT STILL WILL BE VERY WINDY AT TIMES THROUGH MIDDAY. IN THE MTNS MOISTURE WAS INCREASING EARLY THIS MORNING AND COMBINED WITH FAVORABLE OROGRAPHICS WAS PRODUCING SNOW IN THE MTNS WITH AREAS OF BLOWING SNOW OVER THE HIGHER PASSES. MOISTURE IS FCST TO DECREASE BY MIDDAY THRU THE EARLY EVENING HOURS SO SNOW COVERAGE WILL LIKELY DECREASE BY 18Z ALTHOUGH AREAS OF BLOWING SNOW WILL STILL BE POSSIBLE. ACROSS NERN CO WITH RATHER STG NWLY FLOW IN THE LOWER LEVELS AS MIXING OCCURS LATER THIS MORNING THRU THE AFTN HOURS WILL SEE GUSTY NORTHWEST WINDS WITH SOME GUSTS IN THE 40-50 MPH RANGE AT TIMES. AS FOR HIGHS WILL KEEP READINGS IN THE 45 TO 50 DEGREE RANGE OVER THE PLAINS. FOR TONIGHT MOISTURE MAY INCREASE IN THE MTNS AFTER MIDNIGHT WITH BETTER COVERAGE OF SNOW ESPECIALLY NORTH OF I-70. WINDS WILL REMAIN GUSTY IN THE MTNS AND FOOTHILLS HOWEVER CROSS MTN FLOW IS ONLY IN THE 45-50 KT RANGE OVERNIGHT WITH A WEAKER MTN WAVE AS COMPARED TO LAST NIGHT. THUS POTENTIAL FOR HIGH WINDS LOOKS ON THE LOW SIDE AT THIS POINT HOWEVER STILL MAY SEE A FEW GUSTS TO 60-70 MPH AT TIMES IN A FEW LOCATIONS. LONG TERM...STRONG WESTERLY JET LEVEL FLOW IS PROGGED TO CONTINUE OVER THE CWA SATURDAY INTO SUNDAY MORNING. FOR THE REST TO SUNDAY AND SUNDAY NIGHT...THE FLOW ALOFT DECREASES A BIT AND IS WEST-NORTHWESTERLY. THERE IS QG ASCENT PROGGED FOR THE CWA SATURDAY INTO THE EARLY EVENING...THEN DOWNWARD MOTION IS PROGGED WELL INTO SUNDAY. THERE IS WEAK UPWARD TO NEUTRAL SYNOPTIC SCALE ENERGY FOR SUNDAY NIGHT. THE LOW LEVEL PRESSURE AND WIND FIELDS POINT TO NORMAL DIURNAL PATTERNS FOR WINDS SATURDAY. MODELS DO NOT BRING THE COLD FRONT INTO THE CWA UNTIL LATE AFTERNOON/EARLY EVENING. UPSLOPE IS PROGGED ALL OF SATURDAY NIGHT...WITH SOUTHEASTERLIES ON SUNDAY. TROUGHING IS PROGGED TO DEVELOP EAST OF THE MOUNTAINS SUNDAY NIGHT...AND ENHANCED DRAINAGE WIND PATTERNS CAN BE EXPECTED FOR THE PLAINS AND FOOTHILLS. FOR MOISTURE... THERE IS SOME OVER THE MOUNTAINS ON SATURDAY...AND LITTLE OVER THE PLAINS. IT IS A BIT DEEPER OVER THE MOUNTAINS SATURDAY NIGHT... WITH A BIT AT THE LOWER LEVELS FOR THE PLAINS. THERE IS SOME MOISTURE HANGING AROUND OVER THE MOUNTAINS SUNDAY AND SUNDAY NIGHT...WITH A BIT OVER THE PLAINS IN THE MORNING ONLY. OVERALL .MOISTURE IS LESS ON THESE 00Z MODEL RUNS COMPARED TO YESTERDAY`S. THE QPF FIELDS HAVE SMALL AMOUNTS OF MEASURABLE SNOWFALL OVER THE MOUNTAINS SATURDAY THROUGH ABOUT MID DAY SUNDAY. THERE IS A TAD OVER THE PLAINS...MOSTLY THE NORTHERN HALF... SATURDAY AFTERNOON LATE INTO SUNDAY MORNING. FOR POPS WILL GO WITH 40-70%S IN THE MOUNTAINS SATURDAY AND SATURDAY NIGHT. WILL GO WITH "CHANCE"S OVER THE NORTHERN HALF OF THE PLAINS SATURDAY NIGHT. WINDS SHOULD BE BE PARTICULARLY STRONG. THERE WILL BE SOME DECREASING POPS OVER THE MOUNTAINS AND NORTHEAST CORNER ON SUNDAY. SUNDAY NIGHT SHOULD BE DRY. FOR TEMPERATURES...SATURDAY`S HIGHS SHOULD ONLY BE A TAD COLDER THAN TODAY`S...ESPECIALLY SINCE THE COLD FRONT IS PROGGED IN LATE DAY. SUNDAY`S HIGHS ARE 1-3 C COLDER THAN SATURDAY`S. FOR THE LATER DAYS...MONDAY THROUGH THURSDAY... WEAKER WEST-NORTHWESTERLY FLOW IS PROGGED MONDAY INTO TUESDAY. A WEAK UPPER TROUGH SLIDES IN FROM THE NORTHWEST LATER TUESDAY AND TUESDAY NIGHT WITH AN ASSOCIATED COLD FRONT. TUESDAY LOOKS TO HAVE BETTER POPS FOR ALL THE CWA THAN PREVIOUS MODELS INDICATED. THE WEST-NORTHWESTERLY FLOW ALOFT CONTINUES ON WEDNESDAY AND THURSDAY. THERE IS AN UPPER RIDGE AXIS JUST WEST OF THE CWA ON THURSDAY. AVIATION...WNW WINDS WERE ALREADY OCCURRING AT DIA WITH GUSTS TO 25 MPH AT TIMES EARLY THIS MORNING. BOTH THE HRRR AND RAP SHOW GUSTY WNW WINDS THRU 00Z WITH SOME GUSTS TO 40 MPH AT TIMES. AFTER 00Z WINDS MAY BECOME MORE WLY WITH SPEEDS IN THE 10-20 MPH RANGE WHICH WILL GRADUALLY BECOME MORE SSW AFTER 03Z. OTHERWISE EXPECT VFR CONDITIONS TODAY THRU TONIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RPK LONG TERM....RJK UPDATE/AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
535 AM MST FRI FEB 21 2014 .UPDATE... && .SHORT TERM...WINDS HAVE DROPPED OFF TO BLO WARNING LEVELS EVEN AT THE NORMAL WINDY SPOTS SO WILL CANCEL THE HI WIND WARNING EARLY. .PREV DISCUSSION... /ISSUED 344 AM MST FRI FEB 21 2014/ SHORT TERM...NW FLOW ALOFT WILL REMAIN OVER THE AREA TODAY THRU TONIGHT. DECENT WIND EVENT OCCURRED LATE LAST EVENING INTO THE EARLY MORNING HOURS IN AND NEAR THE FOOTHILLS OF BOULDER AND JEFFERSON COUNTIES AS GUSTS RANGED FROM 70-90 MPH. THE LAST FEW HOURS WINDS HAVE DECREASED WITH GUSTS MAINLY IN THE 50-60 MPH RANGE WITH A FEW GUSTS TO 70 MPH AT TIMES. OVERALL MTN WAVE SHOULD BREAKDOWN BY 12Z WITH THREAT OF HIGH WINDS GRADUALLY BY 9 AM IF NOT SOONER. HOWEVER IT STILL WILL BE VERY WINDY AT TIMES THROUGH MIDDAY. IN THE MTNS MOISTURE WAS INCREASING EARLY THIS MORNING AND COMBINED WITH FAVORABLE OROGRAPHICS WAS PRODUCING SNOW IN THE MTNS WITH AREAS OF BLOWING SNOW OVER THE HIGHER PASSES. MOISTURE IS FCST TO DECREASE BY MIDDAY THRU THE EARLY EVENING HOURS SO SNOW COVERAGE WILL LIKELY DECREASE BY 18Z ALTHOUGH AREAS OF BLOWING SNOW WILL STILL BE POSSIBLE. ACROSS NERN CO WITH RATHER STG NWLY FLOW IN THE LOWER LEVELS AS MIXING OCCURS LATER THIS MORNING THRU THE AFTN HOURS WILL SEE GUSTY NORTHWEST WINDS WITH SOME GUSTS IN THE 40-50 MPH RANGE AT TIMES. AS FOR HIGHS WILL KEEP READINGS IN THE 45 TO 50 DEGREE RANGE OVER THE PLAINS. FOR TONIGHT MOISTURE MAY INCREASE IN THE MTNS AFTER MIDNIGHT WITH BETTER COVERAGE OF SNOW ESPECIALLY NORTH OF I-70. WINDS WILL REMAIN GUSTY IN THE MTNS AND FOOTHILLS HOWEVER CROSS MTN FLOW IS ONLY IN THE 45-50 KT RANGE OVERNIGHT WITH A WEAKER MTN WAVE AS COMPARED TO LAST NIGHT. THUS POTENTIAL FOR HIGH WINDS LOOKS ON THE LOW SIDE AT THIS POINT HOWEVER STILL MAY SEE A FEW GUSTS TO 60-70 MPH AT TIMES IN A FEW LOCATIONS. LONG TERM...STRONG WESTERLY JET LEVEL FLOW IS PROGGED TO CONTINUE OVER THE CWA SATURDAY INTO SUNDAY MORNING. FOR THE REST TO SUNDAY AND SUNDAY NIGHT...THE FLOW ALOFT DECREASES A BIT AND IS WEST-NORTHWESTERLY. THERE IS QG ASCENT PROGGED FOR THE CWA SATURDAY INTO THE EARLY EVENING...THEN DOWNWARD MOTION IS PROGGED WELL INTO SUNDAY. THERE IS WEAK UPWARD TO NEUTRAL SYNOPTIC SCALE ENERGY FOR SUNDAY NIGHT. THE LOW LEVEL PRESSURE AND WIND FIELDS POINT TO NORMAL DIURNAL PATTERNS FOR WINDS SATURDAY. MODELS DO NOT BRING THE COLD FRONT INTO THE CWA UNTIL LATE AFTERNOON/EARLY EVENING. UPSLOPE IS PROGGED ALL OF SATURDAY NIGHT...WITH SOUTHEASTERLIES ON SUNDAY. TROUGHING IS PROGGED TO DEVELOP EAST OF THE MOUNTAINS SUNDAY NIGHT...AND ENHANCED DRAINAGE WIND PATTERNS CAN BE EXPECTED FOR THE PLAINS AND FOOTHILLS. FOR MOISTURE... THERE IS SOME OVER THE MOUNTAINS ON SATURDAY...AND LITTLE OVER THE PLAINS. IT IS A BIT DEEPER OVER THE MOUNTAINS SATURDAY NIGHT... WITH A BIT AT THE LOWER LEVELS FOR THE PLAINS. THERE IS SOME MOISTURE HANGING AROUND OVER THE MOUNTAINS SUNDAY AND SUNDAY NIGHT...WITH A BIT OVER THE PLAINS IN THE MORNING ONLY. OVERALL ..MOISTURE IS LESS ON THESE 00Z MODEL RUNS COMPARED TO YESTERDAY`S. THE QPF FIELDS HAVE SMALL AMOUNTS OF MEASURABLE SNOWFALL OVER THE MOUNTAINS SATURDAY THROUGH ABOUT MID DAY SUNDAY. THERE IS A TAD OVER THE PLAINS...MOSTLY THE NORTHERN HALF... SATURDAY AFTERNOON LATE INTO SUNDAY MORNING. FOR POPS WILL GO WITH 40-70%S IN THE MOUNTAINS SATURDAY AND SATURDAY NIGHT. WILL GO WITH "CHANCE"S OVER THE NORTHERN HALF OF THE PLAINS SATURDAY NIGHT. WINDS SHOULD BE BE PARTICULARLY STRONG. THERE WILL BE SOME DECREASING POPS OVER THE MOUNTAINS AND NORTHEAST CORNER ON SUNDAY. SUNDAY NIGHT SHOULD BE DRY. FOR TEMPERATURES...SATURDAY`S HIGHS SHOULD ONLY BE A TAD COLDER THAN TODAY`S...ESPECIALLY SINCE THE COLD FRONT IS PROGGED IN LATE DAY. SUNDAY`S HIGHS ARE 1-3 C COLDER THAN SATURDAY`S. FOR THE LATER DAYS...MONDAY THROUGH THURSDAY... WEAKER WEST-NORTHWESTERLY FLOW IS PROGGED MONDAY INTO TUESDAY. A WEAK UPPER TROUGH SLIDES IN FROM THE NORTHWEST LATER TUESDAY AND TUESDAY NIGHT WITH AN ASSOCIATED COLD FRONT. TUESDAY LOOKS TO HAVE BETTER POPS FOR ALL THE CWA THAN PREVIOUS MODELS INDICATED. THE WEST-NORTHWESTERLY FLOW ALOFT CONTINUES ON WEDNESDAY AND THURSDAY. THERE IS AN UPPER RIDGE AXIS JUST WEST OF THE CWA ON THURSDAY. && .AVIATION...WNW WINDS WERE ALREADY OCCURRING AT DIA WITH GUSTS TO 25 MPH AT TIMES EARLY THIS MORNING. BOTH THE HRRR AND RAP SHOW GUSTY WNW WINDS THRU 00Z WITH SOME GUSTS TO 40 MPH AT TIMES. AFTER 00Z WINDS MAY BECOME MORE WLY WITH SPEEDS IN THE 10-20 MPH RANGE WHICH WILL GRADUALLY BECOME MORE SSW AFTER 03Z. OTHERWISE EXPECT VFR CONDITIONS TODAY THRU TONIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...RPK LONG TERM....RJK AVIATION...RPK
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
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`S. THE QPF FIELDS HAVE SMALL AMOUNTS OF MEASURABLE SNOWFALL OVER THE MOUNTAINS SATURDAY THROUGH ABOUT MID DAY SUNDAY. THERE IS A TAD OVER THE PLAINS...MOSTLY THE NORTHERN HALF... SATURDAY AFTERNOON LATE INTO SUNDAY MORNING. FOR POPS WILL GO WITH 40-70%S IN THE MOUNTAINS SATURDAY AND SATURDAY NIGHT. WILL GO WITH "CHANCE"S OVER THE NORTHERN HALF OF THE PLAINS SATURDAY NIGHT. WINDS SHOULD BE BE PARTICULARLY STRONG. THERE WILL BE SOME DECREASING POPS OVER THE MOUNTAINS AND NORTHEAST CORNER ON SUNDAY. SUNDAY NIGHT SHOULD BE DRY. FOR TEMPERATURES...SATURDAY`S HIGHS SHOULD ONLY BE A TAD COLDER THAN TODAY`S...ESPECIALLY SINCE THE COLD FRONT IS PROGGED IN LATE DAY. SUNDAY`S HIGHS ARE 1-3 C COLDER THAN SATURDAY`S. FOR THE LATER DAYS...MONDAY THROUGH THURSDAY... WEAKER WEST-NORTHWESTERLY FLOW IS PROGGED MONDAY INTO TUESDAY. A WEAK UPPER TROUGH SLIDES IN FROM THE NORTHWEST LATER TUESDAY AND TUESDAY NIGHT WITH AN ASSOCIATED COLD FRONT. TUESDAY LOOKS TO HAVE BETTER POPS FOR ALL THE CWA THAN PREVIOUS MODELS INDICATED. THE WEST-NORTHWESTERLY FLOW ALOFT CONTINUES ON WEDNESDAY AND THURSDAY. THERE IS AN UPPER RIDGE AXIS JUST WEST OF THE CWA ON THURSDAY. && .AVIATION...WNW WINDS WERE ALREADY OCCURRING AT DIA WITH GUSTS TO 25 MPH AT TIMES EARLY THIS MORNING. BOTH THE HRRR AND RAP SHOW GUSTY WNW WINDS THRU 00Z WITH SOME GUSTS TO 40 MPH AT TIMES. AFTER 00Z WINDS MAY BECOME MORE WLY WITH SPEEDS IN THE 10-20 MPH RANGE WHICH WILL GRADUALLY BECOME MORE SSW AFTER 03Z. OTHERWISE EXPECT VFR CONDITIONS TODAY THRU TONIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 9 AM MST THIS MORNING FOR COZ033>036-038- 039. && $$ SHORT TERM...RPK LONG TERM....RJK AVIATION...RPK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1117 PM MST THU FEB 20 2014 .UPDATE... ISSUED AT 1115 PM MST THU FEB 20 2014 AFTER A LOOK AT THE 00Z GFS MODEL AND WHAT IS NOT HAPPENING ON SATELLITE...WE HAVE CANCELLED THE WINTER WEATHER ADVISORIES OVER THE NORTHERN COLORADO MTNS. THANKS TO PUB FOR COORDINATION. UPDATE ISSUED AT 945 PM MST THU FEB 20 2014 SURFACE HIGH PRESSURE IS CENTERED OVER THE FOUR CORNERS AREA TONIGHT BRINGING STRONGER INVERSIONS TO THE SOUTH AND THUS MUCH COLDER TEMPERATURES THAN 24 HRS AGO. THE GRADIENT REMAINS TIGHT ACROSS THE NORTH ESPECIALLY ALONG THE PARK/GORE RANGES. CLOUDS ARE STRETCHED ALONG THE WYOMING BORDER AND ALONG THE CONTINENTAL DIVIDE. CONCERNING THE ADVISORIES IN THE NW COLORADO MTNS...THE 00Z NAM PRODUCES ONLY VERY LIGHT SNOW ACROSS THE EASTERN MTNS TONIGHT AND EVEN INTO FRIDAY. NAM AND RAP FORECAST SOUNDINGS SHOW THE PROFILE BECOMING MUCH MORE STABLE IN MILD 700MB WARM ADVECTION BUT ALSO THE PROFILE IS NOT FULLY SATURATING. THE PROFILE BECOMES MILDLY UNSTABLE THROUGH A SHALLOW LAYER TO ABOUT 11KFT ON FRIDAY. ITS NOT UNTIL AROUND SUNSET FRIDAY THAT A 100KT JET NOSES IN FROM THE NW AND PRODUCES SOME ADDITIONAL FORCING THAT SNOW REALLY STARTS TO ACCUMULATE. WILL LOOK CLOSELY AT THE NEW GFS AND THE CURRENT HIGHLIGHTS TONIGHT. ELSEWHERE AFTER A COLD START TO THE DAY EXPECT PERIODS OF CLOUDS AND DAYTIME TEMPERATURES RECOVERING TO JUST BELOW NORMAL. && .SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT) ISSUED AT 344 PM MST THU FEB 20 2014 THE LAST STORM SYSTEM HAS MOVED ONTO THE PLAINS WHERE IT IS PRODUCING SEVERE WEATHER THIS AFTERNOON. IN IT/S WAKE...COLDER TEMPERATURES AND ISOLATED TO SCATTERED SHOWERS PERSIST ACROSS THE DIVIDE MOUNTAINS. WINDS ALSO CONTINUE TO GUST OVER 35 MPH ALONG THE SPINE OF THE ROCKIES AND THIS IS LIKELY TO CONTINUE OVER THE NEXT FEW DAYS AS FAST NORTHWEST FLOW WAVERS OVER SOUTHERN WYOMING AND NORTHERN COLORADO. THE INFUSION OF PACIFIC MOISTURE AND EMBEDDED ENERGY WILL BRING WAVES OF SNOW TO THE REGION WITH THE NEXT BATCH EXPECTED OVERNIGHT. 290-300K MOISTURE TRANSPORT VECTORS SHOW THIS MOISTURE ARRIVING THROUGH THE EVENING ALONG WITH AN INCREASE IN JET LEVEL WINDS. WAA INCREASES WITH THE APPROACH OF MID LEVEL ENERGY AND THIS DEEPENS THE DENDRITIC LAYER UP NORTH AS THE LOWER PORTION OF THE SOUNDING APPROACHES ISOTHERMAL. NEGATIVE EPV VALUES JUST ABOVE THIS LAYER ALSO SUGGEST SOME POTENTIAL FOR BETTER SNOWFALL PRODUCTION ACROSS THE NORTHERN MOUNTAINS THROUGH SUNRISE. THOUGH MID LEVEL TEMPERATURES ARE WARMING...AFTERNOON SOUNDING ALSO SUGGEST STEEP LAPSE RATES REMAINING IN PLACE THROUGH THE DENDRITIC LAYER. THIS SHOULD HELP PRODUCE SOME HEAVIER AREAS OF SNOWFALL AS THE PRECIPITATION BECOMES MORE CONVECTIVE THROUGH THE AFTERNOON. SNOW AMOUNTS IN THE 4-8 INCH RANGE EXPECTED OVER 9000 FEET IN PORTIONS OF THE CENTRAL AND NORTHERN MOUNTAINS WITH LOCALLY HIGHER ON FAVORED SLOPES. AGAIN FEEL THAT THE GUSTY WINDS AND NEAR WHITEOUT CONDITIONS WILL KEEP A THREAT OF HAZARDOUS TRAVEL CONDITIONS IN PLACE AND HAVE HOISTED AN ADVISORY THROUGH FRIDAY EVENING. THERE LOOKS TO BE A SHORT BREAK MOVE THROUGH THE EARLY MORNING HOURS ON SATURDAY BEFORE ANOTHER SURGE OF MID LEVEL ENERGY AND JET LEVEL WINDS INCREASE SNOW INTENSITY ON SATURDAY. THE ONE CAVEAT IS SNOW MAY NOT ENTIRELY END ACROSS THE PORTIONS OF THE PARK AND GORE RANGE WHERE THE OROGRAPHIC WINDS REMAIN FAVORABLE. TEMPERATURES THROUGH THIS TIME WILL GRADUALLY WARM...ESPECIALLY IN THE LOWER VALLEYS OF THE SOUTHWEST WHERE HIGHS SHOULD REACH BACK TOWARD NORMAL. THE MOUNTAINS WILL WARM AS WELL BUT STILL REMAIN FAVORABLE FOR SNOW REACHING INTO THE HIGH VALLEYS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 344 PM MST THU FEB 20 2014 SNOW IS EXPECTED TO PICK UP AGAIN ACROSS THE NORTHERN CO MTNS SAT AND SAT NIGHT AS ANOTHER WAVE EMBEDDED IN THE NORTHWEST FLOW PASSES. 30-40 KT WESTERLY WINDS AT MTN TOP LEVEL WILL CONTINUE THE WINDY CONDITIONS UP HIGH WITH AREAS OF BLOWING SNOW. SNOW LIKELY TO EXTEND AS FAR SOUTH AS PERHAPS CRESTED BUTTE BUT ACCUMULATIONS SHOULD TAPER RATHER QUICKLY SOUTH OF I-70. A DECREASING CHANCE OF SNOW WILL LINGER ACROSS THE NORTHERN CO MTNS SUNDAY. A HIGH AMPLITUDE RIDGE IS EXPECTED ALONG THE WEST COAST OF NORTH AMERICA THE FIRST HALF OF NEXT WEEK WHILE A LARGE AREA OF LOW PRESSURE RESIDES OVER ERN CANADA. THIS WILL GENERALLY KEEP DRIER NORTHWEST FLOW ACROSS OUR FORECAST AREA BUT SHIFT JET STREAM TO OUR NORTHEAST AS THE RIDGE BUILDS INTO THE GREAT BASIN. MODELS SHOW A SMALL DISTURBANCE MOVING EAST ACROSS THE 4 CORNERS MONDAY FOR SOME CLOUDS BUT NO PRECIP. MODELS ALSO SHOW A DISTURBANCE ROTATING AROUND THE CANADIAN LOW BRUSHING OUR NORTHERN MTNS TUE-WED FOR A SLIGHT CHANCE/CHANCE OF SNOW THERE. TEMPS WILL BE SEASONABLE. A STRONG WESTERLY PACIFIC JET IS SHOWN UNDERCUTTING THE WESTERN RIDGE AFTER WEDNESDAY AND QUICKLY PUNCHES MOISTURE INLAND ACROSS THE GREAT BASIN. MODELS ARE IN GOOD AGREEMENT HERE...SO PRECIP CHANCES SHOULD BE INCREASING THE LAST HALF OF NEXT WEEK. BUT WITH THE AIR ORIGINATING OVER THE PACIFIC...WILL PROBABLY BE SEEING SNOW LEVELS ON THE RISE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY EVENING) ISSUED AT 945 PM MST THU FEB 20 2014 VFR CONDITIONS DOMINATE WITH CIGS 060-070 ONLY AT KCAG KHDN KSBS. VFR CIGS WILL INCREASE ACROSS MUCH OF THE REGION TONIGHT. LOWERING CLOUDS AND INCREASING PRECIPITATION OVER THE NORTHERN AND CENTRAL COLORADO MOUNTAINS WILL BEGIN TO IMPACT THE KEGE AND KASE FLIGHT TERMINALS TOWARD 12Z. LOWERED FLIGHT CRITERIA AT THESE TERMINALS MAY PERSIST INTO THE AFTERNOON HOURS ON FRIDAY AS SNOW SHOWERS PASS BY...BUT THEY SHOULD SHOW A GENERAL UPWARD TREND TOWARD VFR. THE REMAINING FLIGHT TERMINALS SHOULD REMAIN AT VFR LEVELS. GUSTY MOUNTAIN TOP WINDS WILL LEAD TO MECHANICAL TURBULENCE THROUGH THE NEXT 24 HOURS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATES...JOE SHORT TERM...15 LONG TERM...JAD AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
947 PM MST THU FEB 20 2014 .UPDATE... ISSUED AT 945 PM MST THU FEB 20 2014 SURFACE HIGH PRESSURE IS CENTERED OVER THE FOUR CORNERS AREA TONIGHT BRINGING STRONGER INVERSIONS TO THE SOUTH AND THUS MUCH COLDER TEMPERATURES THAN 24 HRS AGO. THE GRADIENT REMAINS TIGHT ACROSS THE NORTH ESPECIALLY ALONG THE PARK/GORE RANGES. CLOUDS ARE STRETCHED ALONG THE WYOMING BORDER AND ALONG THE CONTINENTAL DIVIDE. CONCERNING THE ADVISORIES IN THE NW COLORADO MTNS...THE 00Z NAM PRODUCES ONLY VERY LIGHT SNOW ACROSS THE EASTERN MTNS TONIGHT AND EVEN INTO FRIDAY. NAM AND RAP FORECAST SOUNDINGS SHOW THE PROFILE BECOMING MUCH MORE STABLE IN MILD 700MB WARM ADVECTION BUT ALSO THE PROFILE IS NOT FULLY SATURATING. THE PROFILE BECOMES MILDLY UNSTABLE THROUGH A SHALLOW LAYER TO ABOUT 11KFT ON FRIDAY. ITS NOT UNTIL AROUND SUNSET FRIDAY THAT A 100KT JET NOSES IN FROM THE NW AND PRODUCES SOME ADDITIONAL FORCING THAT SNOW REALLY STARTS TO ACCUMULATE. WILL LOOK CLOSELY AT THE NEW GFS AND THE CURRENT HIGHLIGHTS TONIGHT. ELSEWHERE AFTER A COLD START TO THE DAY EXPECT PERIODS OF CLOUDS AND DAYTIME TEMPERATURES RECOVERING TO JUST BELOW NORMAL. && .SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT) ISSUED AT 344 PM MST THU FEB 20 2014 THE LAST STORM SYSTEM HAS MOVED ONTO THE PLAINS WHERE IT IS PRODUCING SEVERE WEATHER THIS AFTERNOON. IN IT/S WAKE...COLDER TEMPERATURES AND ISOLATED TO SCATTERED SHOWERS PERSIST ACROSS THE DIVIDE MOUNTAINS. WINDS ALSO CONTINUE TO GUST OVER 35 MPH ALONG THE SPINE OF THE ROCKIES AND THIS IS LIKELY TO CONTINUE OVER THE NEXT FEW DAYS AS FAST NORTHWEST FLOW WAVERS OVER SOUTHERN WYOMING AND NORTHERN COLORADO. THE INFUSION OF PACIFIC MOISTURE AND EMBEDDED ENERGY WILL BRING WAVES OF SNOW TO THE REGION WITH THE NEXT BATCH EXPECTED OVERNIGHT. 290-300K MOISTURE TRANSPORT VECTORS SHOW THIS MOISTURE ARRIVING THROUGH THE EVENING ALONG WITH AN INCREASE IN JET LEVEL WINDS. WAA INCREASES WITH THE APPROACH OF MID LEVEL ENERGY AND THIS DEEPENS THE DENDRITIC LAYER UP NORTH AS THE LOWER PORTION OF THE SOUNDING APPROACHES ISOTHERMAL. NEGATIVE EPV VALUES JUST ABOVE THIS LAYER ALSO SUGGEST SOME POTENTIAL FOR BETTER SNOWFALL PRODUCTION ACROSS THE NORTHERN MOUNTAINS THROUGH SUNRISE. THOUGH MID LEVEL TEMPERATURES ARE WARMING...AFTERNOON SOUNDING ALSO SUGGEST STEEP LAPSE RATES REMAINING IN PLACE THROUGH THE DENDRITIC LAYER. THIS SHOULD HELP PRODUCE SOME HEAVIER AREAS OF SNOWFALL AS THE PRECIPITATION BECOMES MORE CONVECTIVE THROUGH THE AFTERNOON. SNOW AMOUNTS IN THE 4-8 INCH RANGE EXPECTED OVER 9000 FEET IN PORTIONS OF THE CENTRAL AND NORTHERN MOUNTAINS WITH LOCALLY HIGHER ON FAVORED SLOPES. AGAIN FEEL THAT THE GUSTY WINDS AND NEAR WHITEOUT CONDITIONS WILL KEEP A THREAT OF HAZARDOUS TRAVEL CONDITIONS IN PLACE AND HAVE HOISTED AN ADVISORY THROUGH FRIDAY EVENING. THERE LOOKS TO BE A SHORT BREAK MOVE THROUGH THE EARLY MORNING HOURS ON SATURDAY BEFORE ANOTHER SURGE OF MID LEVEL ENERGY AND JET LEVEL WINDS INCREASE SNOW INTENSITY ON SATURDAY. THE ONE CAVEAT IS SNOW MAY NOT ENTIRELY END ACROSS THE PORTIONS OF THE PARK AND GORE RANGE WHERE THE OROGRAPHIC WINDS REMAIN FAVORABLE. TEMPERATURES THROUGH THIS TIME WILL GRADUALLY WARM...ESPECIALLY IN THE LOWER VALLEYS OF THE SOUTHWEST WHERE HIGHS SHOULD REACH BACK TOWARD NORMAL. THE MOUNTAINS WILL WARM AS WELL BUT STILL REMAIN FAVORABLE FOR SNOW REACHING INTO THE HIGH VALLEYS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 344 PM MST THU FEB 20 2014 SNOW IS EXPECTED TO PICK UP AGAIN ACROSS THE NORTHERN CO MTNS SAT AND SAT NIGHT AS ANOTHER WAVE EMBEDDED IN THE NORTHWEST FLOW PASSES. 30-40 KT WESTERLY WINDS AT MTN TOP LEVEL WILL CONTINUE THE WINDY CONDITIONS UP HIGH WITH AREAS OF BLOWING SNOW. SNOW LIKELY TO EXTEND AS FAR SOUTH AS PERHAPS CRESTED BUTTE BUT ACCUMULATIONS SHOULD TAPER RATHER QUICKLY SOUTH OF I-70. A DECREASING CHANCE OF SNOW WILL LINGER ACROSS THE NORTHERN CO MTNS SUNDAY. A HIGH AMPLITUDE RIDGE IS EXPECTED ALONG THE WEST COAST OF NORTH AMERICA THE FIRST HALF OF NEXT WEEK WHILE A LARGE AREA OF LOW PRESSURE RESIDES OVER ERN CANADA. THIS WILL GENERALLY KEEP DRIER NORTHWEST FLOW ACROSS OUR FORECAST AREA BUT SHIFT JET STREAM TO OUR NORTHEAST AS THE RIDGE BUILDS INTO THE GREAT BASIN. MODELS SHOW A SMALL DISTURBANCE MOVING EAST ACROSS THE 4 CORNERS MONDAY FOR SOME CLOUDS BUT NO PRECIP. MODELS ALSO SHOW A DISTURBANCE ROTATING AROUND THE CANADIAN LOW BRUSHING OUR NORTHERN MTNS TUE-WED FOR A SLIGHT CHANCE/CHANCE OF SNOW THERE. TEMPS WILL BE SEASONABLE. A STRONG WESTERLY PACIFIC JET IS SHOWN UNDERCUTTING THE WESTERN RIDGE AFTER WEDNESDAY AND QUICKLY PUNCHES MOISTURE INLAND ACROSS THE GREAT BASIN. MODELS ARE IN GOOD AGREEMENT HERE...SO PRECIP CHANCES SHOULD BE INCREASING THE LAST HALF OF NEXT WEEK. BUT WITH THE AIR ORIGINATING OVER THE PACIFIC...WILL PROBABLY BE SEEING SNOW LEVELS ON THE RISE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY EVENING) ISSUED AT 945 PM MST THU FEB 20 2014 VFR CONDITIONS DOMINATE WITH CIGS 060-070 ONLY AT KCAG KHDN KSBS. VFR CIGS WILL INCREASE ACROSS MUCH OF THE REGION TONIGHT. LOWERING CLOUDS AND INCREASING PRECIPITATION OVER THE NORTHERN AND CENTRAL COLORADO MOUNTAINS WILL BEGIN TO IMPACT THE KEGE AND KASE FLIGHT TERMINALS TOWARD 12Z. LOWERED FLIGHT CRITERIA AT THESE TERMINALS MAY PERSIST INTO THE AFTERNOON HOURS ON FRIDAY AS SNOW SHOWERS PASS BY...BUT THEY SHOULD SHOW A GENERAL UPWARD TREND TOWARD VFR. THE REMAINING FLIGHT TERMINALS SHOULD REMAIN AT VFR LEVELS. GUSTY MOUNTAIN TOP WINDS WILL LEAD TO MECHANICAL TURBULENCE THROUGH THE NEXT 24 HOURS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL 11 PM MST FRIDAY ABOVE 9000 FEET FOR COZ004-010-013. UT...NONE. && $$ UPDATE...JOE SHORT TERM...15 LONG TERM...JAD AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS ALBANY NY
105 PM EST FRI FEB 21 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...ACCOMPANIED BY A PERIOD OF RAIN SHOWERS WITH SOME DOWNPOURS AND ISOLATED THUNDER. BEHIND THE FRONT...DRIER AIR WILL FILTER INTO THE REGION TONIGHT. THE AIR MASS BEHIND THE COLD FRONT WILL STILL BE RELATIVELY MILD...SO ABOVE NORMAL TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH MUCH OF THE WEEKEND. MUCH COLDER AIR WILL MOVE INTO THE REGION NEXT WEEK. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1245 PM...TEMPERATURES CONTINUE TO ONLY SLOWLY RISE IN MOST AREAS EARLY THIS AFTERNOON DUE TO DEEP SNOWPACK AND NORTHERLY AGEOSTROPHIC WIND COMPONENT. MANY LOCATIONS STILL HAVE TEMPERATURES IN THE MID TO UPPER 30S...ALTHOUGH HIGHER TERRAIN AREAS TO THE WEST AND EAST OF ALBANY HAVE WARMED INTO THE 40S WITH EVEN A POCKET OF LOWER 50S IN PARTS OF SCHOHARIE COUNTY. WE ARE EXPECTING A BRIEF SPIKE IN TEMPS IN THE UPPER 30S TO MID 40S IMMEDIATELY PRECEDING THE COLD FRONT...WHICH AS OF NOON WAS PROGRESSING EASTWARD THROUGH CENTRAL NY/PA. THE FRONT SHOULD CONTINUE TO MAKE STEADY PROGRESS EASTWARD AS THERE ARE GOOD PRESSURE RISES BEHIND THE FRONT. THE COLD FRONT IS STILL EXPECTED TO MOVE FROM WEST TO EAST ACROSS THE AREA DURING THE MID TO LATE AFTERNOON HOURS. A STRONGLY FORCED LINE OF SHOWERS WITH DOWNPOURS...AND POSSIBLY ISOLATED THUNDERSTORMS...WILL MOVE ACROSS THE AREA. THIS SCENARIO IS STILL BEING WELL-DEPICTED BY THE HRRR AND LOCAL HIRES WRF AS WELL. TIMING LOOKS TO BE BASICALLY FROM 1 PM THROUGH 6 PM. SHOWALTER VALUES LOOK TO BE JUST BELOW ZERO...SO SOME ELEVATED INSTABILITY IS POSSIBLE FOR A RUMBLE OR TWO OF THUNDER...BUT NO STRONG/SEVERE STORMS ARE ANTICIPATED DUE TO MEAGER SURFACE BASED INSTABILITY. ONCE THE FRONT GOES THROUGH...THE THREAT FOR SHOWERS WILL DIMINISH GREATLY...AND TEMPS WILL START TO FALL ONCE AGAIN. WITH THE PASSAGE OF THE BOUNDARY...THERE MAY BE A FEW STRONGER GUSTS OF WIND...ESP OVER THE HIGHER TERRAIN. THE BETTER CHANCE FOR STRONG WINDS MAY BE BEHIND THE FRONT...AS COOLER AIR ALOFT ALLOWS FOR BETTER MIXING. && .SHORT TERM /7 PM THIS EVENING THROUGH SUNDAY NIGHT/... BEHIND THE COLD FRONT...COOLER AIR ALOFT WILL MOVE INTO THE REGION AS THE STORM STORM LIFTS UP TOWARDS HUDSON BAY CANADA WITH 850 HPA TEMPS DROPPING BACK BELOW FREEZING. GUSTY W-SW WINDS WILL BE IN PLACE FOR TONIGHT. WHILE MOST AREAS WILL STAY DRY...SOME LINGERING CYCLONIC FLOW RAIN/SNOW SHOWERS CANNOT BE TOTALLY RULED OUT FOR UPSLOPE FAVORED AREAS OF THE WESTERN ADIRONDACKS FOR TONIGHT INTO SATURDAY. OTHERWISE...IT WILL REMAIN DRY. MIN TEMPS WILL BE IN THE 20S TONIGHT. GOOD MIXING TOMORROW WILL PROMOTE A MILD DAY...DESPITE BEING BEHIND THE COLD FRONT...WITH HIGHS RANGING FROM THE MID TO UPPER 30S IN THE HIGH TERRAIN TO THE MID TO UPPER 40S FOR VALLEY AREAS. TEMPS LOOK TO DROP BACK DOWN IN THE TEENS AND 20S FOR SAT NIGHT WITH MAINLY DRY WEATHER. THE MODELS SHOW A QUICK MOVING STORM SYSTEM AFFECTING THE REGION AT SOME POINT BETWEEN SUNDAY AND SUNDAY NIGHT. THE TRACK AND TIMING OF THIS SYSTEM REMAINS IN QUESTION...BUT ALL MODELS AGREE THAT ANY QPF WOULD BE VERY LIGHT...AND IT LOOKS TO MOVE THROUGH RATHER QUICKLY. WITH PRECIP ON THE NORTHERN SIDE OF THE SYSTEM...AND WITH EXPECTED COLDER TEMPS ALOFT...MOST OF THE PRECIP SHOULD BE SNOW...PERHAPS MIXING WITH A LITTLE BIT OF RAIN AT TIMES FOR VALLEY AREAS. JUST AN INCH OR TWO OF SNOW LOOKS TO OCCUR. FOR NOW...WILL JUST GO WITH CHC POPS FOR SUN/SUN NIGHT DUE TO UNCERTAINTY REGARDING ITS EXACT TRACK/TIMING. MAX TEMPS WILL BE IN THE 30S...AND MINS SUNDAY NIGHT LOOK TO BE IN THE TEENS/20S. && .LONG TERM /MONDAY THROUGH THURSDAY/... MAINLY DRY AND VERY COLD CONDITIONS ARE EXPECTED FOR MUCH OF THE LONG TERM PERIOD. ANY CHANCES FOR PCPN WILL BE MAINLY TIED TO LAKE EFFECT DOWNWIND OF LAKE ONTARIO ALTHOUGH A WEAK COASTAL LOW PASSES SOUTHEAST OF OUR REGION ON TUESDAY WITH A STRONGER COASTAL LOW FOLLOWING A SIMILAR TRACK ON WEDNESDAY. SINCE THIS SYSTEM LOOKS TO BE STRONGER AND TRACK A LITTLE CLOSER TO OUR REGION WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR NOW. IN ADDITION TO THE VERY COLD AIR IN PLACE ACRS OUR REGION WIND CHILLS MAY REACH ADVISORY CRITERIA WEDNESDAY NIGHT AND THURSDAY ACRS THE HIGHER TERRAIN. THIS WILL BE MENTIONED IN THE HWO. AS FOR TEMPS EXPECT HIGHS ON MONDAY TO RANGE FROM THE UPPER TEENS NORTHWEST TO MID 30S SOUTHEAST WITH HIGHS TUESDAY...WEDNESDAY AND THURSDAY RANGING FROM THE MID TEENS NORTHWEST TO UPPER 20S SOUTHEAST. LOWS MONDAY NIGHT WILL BE IN THE SINGLE DIGITS TO LOWER TEENS WITH LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT MAINLY IN THE 5 BELOW TO 10 ABOVE ZERO RANGE. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... THE 2 TO 3 HOUR BAND OF RAIN ASSOCIATED WITH COLD FRONT THAT WILL MOVE THROUGH THE REGION THIS AFTERNOON...WILL BEGIN TO AFFECT THE TAF SITES BETWEEN 19Z AND 20Z...AND THEN DEPART BETWEEN 22Z AND 23Z. WITH IFR/MVFR CONDITONS ALREADY OCCURRING AHEAD OF THIS RAINFALL...HAVE FORECAST IFR/MVFR CONDITIONS AT THE TAF SITES THROUGH 22Z-23Z. AFTER 23Z DRIER AIR WILL MOVE IN AND CIGS MAY REMAIN MVFR FOR SEVERAL MORE HOURS...THEN EXPECT SKIES TO BECOME MAINLY CLEAR AFTER MIDNIGHT AT ALL THE TAF SITES. WINDS WILL BE LIGHT AND VARIABLE AT THE TAF SITES EXPECT FOR KALB WHERE WINDS WILL BE SOUTH AT AROUND 10 KTS WITH GUSTS OF AROUND 15 KTS. BEHIND THE FRON THE WINDS WILL BECOME WEST OR SOUTHWEST AT 5 TO 10 KTS...BUT GUST UP TO 15 TO 18 KTS AT KALB AND KPSF. THE WINDS WILL DECREASE OVERNIGHT...BUT THEN PICK UP AGAIN FROM THE SOUTHWEST AT 08 TO 14 KTS BY MID MORNING SATURDAY...WITH GUSTS ABOVE 20 KTS... ESPECIALLY AT KALB. OUTLOOK... SATURDAT AFTERNOON AND NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY-SUNDAY NIGHT: LOW OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. MONDAY-MONDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... THE SNOW DEPTH ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW ENGLAND CONTINUES TO GENERALLY RANGE FROM 10 TO 30 INCHES...WITH SOME HIGHER AMOUNTS IN THE MOUNTAINS. NOT MUCH SNOW MELT OCCURRED OVERNIGHT INTO THIS MORNING DUE TO TEMPERATURES REMAINING IN THE 30S. TEMPERATURES HAVE BEEN SLOW TO WARM TODAY...WITH HIGHS EXPECTED TO BE IN THE UPPER 30S TO MID 40S THIS AFTERNOON. MORE RAIN WILL OCCUR THIS AFTERNOON AHEAD OF AND ALONG A COLD FRONT PASSING THROUGH FROM WEST TO EAST. THERE WILL LIKELY BE SOME DOWNPOURS...WHICH COMBINED WITH SNOWPACK...COULD CAUSE PONDING AND/OR MINOR FLOODING OF URBAN AREAS AND POOR DRAINAGE LOCATIONS DUE TO CLOGGED STORM DRAINS. STORM TOTAL QPF STILL EXPECTED TO BE A HALF INCH TO NEARLY ONE AND A HALF INCHES...WITH THE HIGHEST AMOUNTS ACROSS THE ADIRONDACKS. HOWEVER...THIS QPF AND EXPECTED SNOW MELT WILL HAVE A LIMITED RESPONSE ON AREA RIVERS AND STREAMS...AS MUCH OF IT WILL BE ABSORBED BY THE DEEP SNOWPACK. THE LATEST MMEFS...AS WELL AS FORECASTS FROM THE NERFC...DO NOT FORECAST ANY FLOODING OVER THE NEXT DAY OR SO...ALTHOUGH THERE WILL BE SOME RISES ON AREA RIVERS AND STREAMS. DRIER AIR WILL QUICKLY RETURN BEHIND THE COLD FRONT TONIGHT...WITH TEMPERATURES DROPPING BACK BELOW FREEZING ACROSS THE ENTIRE REGION BY EARLY SATURDAY MORNING. DAYTIME TEMPERATURES OVER THE WEEKEND WILL CONTINUE TO BE ABOVE FREEZING...AND OVERNIGHT LOWS WILL DROP BELOW FREEZING THIS WEEKEND. THIS SHOULD ALLOW FOR A STEADY CONTROLLED SNOW MELT...WHICH WILL LIMIT ANY FLOODING CONCERNS. MUCH COLDER WEATHER...WITH TEMPERATURES COMPLETELY BELOW FREEZING...WILL RETURN FOR MUCH OF NEXT WEEK. WE WILL CONTINUE TO MENTION POTENTIAL FOR ISOLATED ICE JAMS ON SMALLER STREAMS AND CREEK IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY INTO TONIGHT DUE TO RAIN MELT AND WARMER TEMPERATURES...BUT WIDESPREAD FLOOD ISSUES ARE NOT ANTICIPATED AT THIS TIME. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...FRUGIS/GJM/JPV SHORT TERM...FRUGIS LONG TERM...11 AVIATION...GJM HYDROLOGY...FRUGIS/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
1246 PM EST FRI FEB 21 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...ACCOMPANIED BY A PERIOD OF RAIN SHOWERS WITH SOME DOWNPOURS AND ISOLATED THUNDER. BEHIND THE FRONT...DRIER AIR WILL FILTER INTO THE REGION TONIGHT. THE AIR MASS BEHIND THE COLD FRONT WILL STILL BE RELATIVELY MILD...SO ABOVE NORMAL TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH MUCH OF THE WEEKEND. MUCH COLDER AIR WILL MOVE INTO THE REGION NEXT WEEK. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1245 PM...TEMPERATURES CONTINUE TO ONLY SLOWLY RISE IN MOST AREAS EARLY THIS AFTERNOON DUE TO DEEP SNOWPACK AND NORTHERLY AGEOSTROPHIC WIND COMPONENT. MANY LOCATIONS STILL HAVE TEMPERATURES IN THE MID TO UPPER 30S...ALTHOUGH HIGHER TERRAIN AREAS TO THE WEST AND EAST OF ALBANY HAVE WARMED INTO THE 40S WITH EVEN A POCKET OF LOWER 50S IN PARTS OF SCHOHARIE COUNTY. WE ARE EXPECTING A BRIEF SPIKE IN TEMPS IN THE UPPER 30S TO MID 40S IMMEDIATELY PRECEDING THE COLD FRONT...WHICH AS OF NOON WAS PROGRESSING EASTWARD THROUGH CENTRAL NY/PA. THE FRONT SHOULD CONTINUE TO MAKE STEADY PROGRESS EASTWARD AS THERE ARE GOOD PRESSURE RISES BEHIND THE FRONT. THE COLD FRONT IS STILL EXPECTED TO MOVE FROM WEST TO EAST ACROSS THE AREA DURING THE MID TO LATE AFTERNOON HOURS. A STRONGLY FORCED LINE OF SHOWERS WITH DOWNPOURS...AND POSSIBLY ISOLATED THUNDERSTORMS...WILL MOVE ACROSS THE AREA. THIS SCENARIO IS STILL BEING WELL-DEPICTED BY THE HRRR AND LOCAL HIRES WRF AS WELL. TIMING LOOKS TO BE BASICALLY FROM 1 PM THROUGH 6 PM. SHOWALTER VALUES LOOK TO BE JUST BELOW ZERO...SO SOME ELEVATED INSTABILITY IS POSSIBLE FOR A RUMBLE OR TWO OF THUNDER...BUT NO STRONG/SEVERE STORMS ARE ANTICIPATED DUE TO MEAGER SURFACE BASED INSTABILITY. ONCE THE FRONT GOES THROUGH...THE THREAT FOR SHOWERS WILL DIMINISH GREATLY...AND TEMPS WILL START TO FALL ONCE AGAIN. WITH THE PASSAGE OF THE BOUNDARY...THERE MAY BE A FEW STRONGER GUSTS OF WIND...ESP OVER THE HIGHER TERRAIN. THE BETTER CHANCE FOR STRONG WINDS MAY BE BEHIND THE FRONT...AS COOLER AIR ALOFT ALLOWS FOR BETTER MIXING. && .SHORT TERM /7 PM THIS EVENING THROUGH SUNDAY NIGHT/... BEHIND THE COLD FRONT...COOLER AIR ALOFT WILL MOVE INTO THE REGION AS THE STORM STORM LIFTS UP TOWARDS HUDSON BAY CANADA WITH 850 HPA TEMPS DROPPING BACK BELOW FREEZING. GUSTY W-SW WINDS WILL BE IN PLACE FOR TONIGHT. WHILE MOST AREAS WILL STAY DRY...SOME LINGERING CYCLONIC FLOW RAIN/SNOW SHOWERS CANNOT BE TOTALLY RULED OUT FOR UPSLOPE FAVORED AREAS OF THE WESTERN ADIRONDACKS FOR TONIGHT INTO SATURDAY. OTHERWISE...IT WILL REMAIN DRY. MIN TEMPS WILL BE IN THE 20S TONIGHT. GOOD MIXING TOMORROW WILL PROMOTE A MILD DAY...DESPITE BEING BEHIND THE COLD FRONT...WITH HIGHS RANGING FROM THE MID TO UPPER 30S IN THE HIGH TERRAIN TO THE MID TO UPPER 40S FOR VALLEY AREAS. TEMPS LOOK TO DROP BACK DOWN IN THE TEENS AND 20S FOR SAT NIGHT WITH MAINLY DRY WEATHER. THE MODELS SHOW A QUICK MOVING STORM SYSTEM AFFECTING THE REGION AT SOME POINT BETWEEN SUNDAY AND SUNDAY NIGHT. THE TRACK AND TIMING OF THIS SYSTEM REMAINS IN QUESTION...BUT ALL MODELS AGREE THAT ANY QPF WOULD BE VERY LIGHT...AND IT LOOKS TO MOVE THROUGH RATHER QUICKLY. WITH PRECIP ON THE NORTHERN SIDE OF THE SYSTEM...AND WITH EXPECTED COLDER TEMPS ALOFT...MOST OF THE PRECIP SHOULD BE SNOW...PERHAPS MIXING WITH A LITTLE BIT OF RAIN AT TIMES FOR VALLEY AREAS. JUST AN INCH OR TWO OF SNOW LOOKS TO OCCUR. FOR NOW...WILL JUST GO WITH CHC POPS FOR SUN/SUN NIGHT DUE TO UNCERTAINTY REGARDING ITS EXACT TRACK/TIMING. MAX TEMPS WILL BE IN THE 30S...AND MINS SUNDAY NIGHT LOOK TO BE IN THE TEENS/20S. && .LONG TERM /MONDAY THROUGH THURSDAY/... MAINLY DRY AND VERY COLD CONDITIONS ARE EXPECTED FOR MUCH OF THE LONG TERM PERIOD. ANY CHANCES FOR PCPN WILL BE MAINLY TIED TO LAKE EFFECT DOWNWIND OF LAKE ONTARIO ALTHOUGH A WEAK COASTAL LOW PASSES SOUTHEAST OF OUR REGION ON TUESDAY WITH A STRONGER COASTAL LOW FOLLOWING A SIMILAR TRACK ON WEDNESDAY. SINCE THIS SYSTEM LOOKS TO BE STRONGER AND TRACK A LITTLE CLOSER TO OUR REGION WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR NOW. IN ADDITION TO THE VERY COLD AIR IN PLACE ACRS OUR REGION WIND CHILLS MAY REACH ADVISORY CRITERIA WEDNESDAY NIGHT AND THURSDAY ACRS THE HIGHER TERRAIN. THIS WILL BE MENTIONED IN THE HWO. AS FOR TEMPS EXPECT HIGHS ON MONDAY TO RANGE FROM THE UPPER TEENS NORTHWEST TO MID 30S SOUTHEAST WITH HIGHS TUESDAY...WEDNESDAY AND THURSDAY RANGING FROM THE MID TEENS NORTHWEST TO UPPER 20S SOUTHEAST. LOWS MONDAY NIGHT WILL BE IN THE SINGLE DIGITS TO LOWER TEENS WITH LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT MAINLY IN THE 5 BELOW TO 10 ABOVE ZERO RANGE. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... MUCH OF THE RAIN HAS ENDED AT LEAST FOR NOW AT THE TAF SITES WITH THE NEXT BATCH OF RAIN AHEAD OF THE COLD FRONT NOT EXPECTED TO ARRIVE UNTIL EARLY AFTERNOON. THE TAF SITES UP UNTIL THIS TIME ARE EXPECTED TO BE MVFR AT KGFL AND KALB WITH IFR/LIFR CONDITIONS EXPECTED AT KPSF AND KPOU WHERE FOG AND LOW STRATUS WL BE PRESENT. IFR CONDITIONS ARE EXPECTED AT ALL OF THE TAF SITES STARTING ARND 18Z AS THE NEXT BATCH OF RAIN MOVES IN. A COLD FRONT WL SWEEP THROUGH THE RGN LATE THIS AFTERNOON WITH SKIES BECOMING SKC THIS EVENING IN THE WAKE OF THE COLD FRONT. WINDS WILL BE LIGHT AND VARIABLE UNTIL EARLY AFTERNOON AND THEN NE-SE ARND 5 KTS AHD OF THE FRONT AND WEST TO SOUTHWEST AT 6 TO 10 KTS IN THE WAKE OF THE COLD FRONT. OUTLOOK... SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY-SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. MONDAY-MONDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... THE SNOW DEPTH ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW ENGLAND CONTINUES TO GENERALLY RANGE FROM 10 TO 30 INCHES...WITH SOME HIGHER AMOUNTS IN THE MOUNTAINS. NOT MUCH SNOW MELT OCCURRED OVERNIGHT INTO THIS MORNING DUE TO TEMPERATURES REMAINING IN THE 30S. TEMPERATURES HAVE BEEN SLOW TO WARM TODAY...WITH HIGHS EXPECTED TO BE IN THE UPPER 30S TO MID 40S THIS AFTERNOON. MORE RAIN WILL OCCUR THIS AFTERNOON AHEAD OF AND ALONG A COLD FRONT PASSING THROUGH FROM WEST TO EAST. THERE WILL LIKELY BE SOME DOWNPOURS...WHICH COMBINED WITH SNOWPACK...COULD CAUSE PONDING AND/OR MINOR FLOODING OF URBAN AREAS AND POOR DRAINAGE LOCATIONS DUE TO CLOGGED STORM DRAINS. STORM TOTAL QPF STILL EXPECTED TO BE A HALF INCH TO NEARLY ONE AND A HALF INCHES...WITH THE HIGHEST AMOUNTS ACROSS THE ADIRONDACKS. HOWEVER...THIS QPF AND EXPECTED SNOW MELT WILL HAVE A LIMITED RESPONSE ON AREA RIVERS AND STREAMS...AS MUCH OF IT WILL BE ABSORBED BY THE DEEP SNOWPACK. THE LATEST MMEFS...AS WELL AS FORECASTS FROM THE NERFC...DO NOT FORECAST ANY FLOODING OVER THE NEXT DAY OR SO...ALTHOUGH THERE WILL BE SOME RISES ON AREA RIVERS AND STREAMS. DRIER AIR WILL QUICKLY RETURN BEHIND THE COLD FRONT TONIGHT...WITH TEMPERATURES DROPPING BACK BELOW FREEZING ACROSS THE ENTIRE REGION BY EARLY SATURDAY MORNING. DAYTIME TEMPERATURES OVER THE WEEKEND WILL CONTINUE TO BE ABOVE FREEZING...AND OVERNIGHT LOWS WILL DROP BELOW FREEZING THIS WEEKEND. THIS SHOULD ALLOW FOR A STEADY CONTROLLED SNOW MELT...WHICH WILL LIMIT ANY FLOODING CONCERNS. MUCH COLDER WEATHER...WITH TEMPERATURES COMPLETELY BELOW FREEZING...WILL RETURN FOR MUCH OF NEXT WEEK. WE WILL CONTINUE TO MENTION POTENTIAL FOR ISOLATED ICE JAMS ON SMALLER STREAMS AND CREEK IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY INTO TONIGHT DUE TO RAIN MELT AND WARMER TEMPERATURES...BUT WIDESPREAD FLOOD ISSUES ARE NOT ANTICIPATED AT THIS TIME. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...FRUGIS/GJM/JPV SHORT TERM...FRUGIS LONG TERM...11 AVIATION...GJM HYDROLOGY...FRUGIS/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
1032 AM EST FRI FEB 21 2014 .SYNOPSIS... AHEAD OF A COLD FRONT...MILDER AIR WILL MOVE INTO THE REGION FOR TODAY...ALONG WITH RAIN SHOWERS...GUSTY WINDS OVER THE HIGH TERRAIN...AND A SLIGHT CHANCE FOR A THUNDERSTORM. AFTER THE FRONT PASSES THROUGH THE REGION LATE TODAY...THE THREAT FOR RAIN SHOWERS WILL END. DAYTIME TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL INTO THE WEEKEND...BUT MUCH COLDER AIR WILL RETURN TO THE REGION FOR MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1015 AM...TEMPS IN NY WERE ALL ABOVE FREEZING...WITH JUST A FEW POCKETS OF BELOW FREEZING TEMPS IN SOUTHERN VERMONT AND BERKSHIRE COUNTY. HOWEVER...RADAR INDICATES TO ADDITIONAL PCPN WILL OCCUR IN SOUTHERN VERMONT AND BERKSHIRE COUNTY UNTIL THIS AFTERNOON...AT WHICH TIME TEMPS WILL BE ABOVE FREEZING IN ALL AREAS THERE AS WELL. AS A RESULT...HAVE CANCELLED ANY REMAINING WINTER WEATHER ADVISORIES. HAVE ALSO MADE ADJUSTMETNS TO THE HOURLY TEMP AND POP GRIDS TO REFLECT CURRENT CONDITIONS AND TRENDS. .PREVIOUS DISCUSSION... AS OF 621 AM EST...A STRONG STORM SYSTEM AND POTENT UPPER LEVEL SHORTWAVE IS MOVING ACROSS THE UPPER GREAT LAKES. A WARM FRONT ASSOCIATED WITH THIS STORM IS HAVING A TOUGH TIME MOVING ACROSS OUR REGION...DUE TO PLENTY OF LOW LEVEL COLD AIR IN PLACE THANKS TO A DEEP SNOW PACK. TEMPERATURES CONTINUE TO BE IN THE 30S ACROSS OUR ENTIRE REGION. STEADY PRECIPITATION HAS MOVED NORTH AND EAST OF THE REGION...AS THE BEST ISENTROPIC LIFT/WARM AIR ADVECTION IS NOW FOCUSED ACROSS NORTHERN NEW ENGLAND. WITH TEMPERATURES WARMING THROUGH THE 30S AND MOST OF THE PRECIPITATION DONE...WE/VE CANCELLED THE WINTER WEATHER ADVISORY FOR MOST OF THE AREA. WE WILL CONTINUE IT FOR A LITTLE LONGER FOR THE EASTERN ADIRONDACKS...LAKE GEORGE AREA...AND SRN VT...AS SOME LIGHT PRECIPITATION REMAINS THERE...AND SOME POCKETS OF 30-32 DEGREES ARE STILL OCCURRING ACCORDING TO MESO OBS AT THIS TIME. ONCE TEMPS WARM UP AND PRECIP ENDS...WE SHOULD BE ABLE TO CANCEL THE ADVISORY. AS SHOWN IN THE MODELS...THIS BREAK IN THE PRECIP LOOKS TO CONTINUE THROUGH MUCH OF THE MORNING HOURS. WE HAVE LOWERED POPS TO CHC THROUGH THE MID MORNING HOURS FOR CENTRAL/SOUTHERN PARTS OF THE AREA. HOWEVER...THE MOIST SOUTHERLY FLOW...COMBINED WITH SOME UPSLOPE...MAY ALLOW FOR SOME SPOTTY AREAS OF LIGHT RAIN SHOWERS BY LATER THIS MORNING...SO WE WILL RAISE POPS BACK UP TO LIKELY FOR THE LATE MORNING HOURS. MAX TEMPS SHOULD WARM UP INTO THE LOWER TO MID 40S FOR VALLEY AREAS...WITH UPPER 30S IN THE HIGH TERRAIN WITH THESE HIGHS IN THE LATE MORNING TO EARLY AFTERNOON. THE STORM/S COLD FRONT LOOKS TO MOVE FROM WEST TO EAST DURING THE AFTERNOON HOURS. A STRONGLY FORCED LINE OF SHOWERS...AND POSSIBLY SOME ISOLATED THUNDERSTORMS...WILL MOVE ACROSS THE AREA. THIS IS SEEN IN THE 09Z 3KM HRRR AS WELL...WITH THE TIMING ACROSS OUR AREA BASICALLY FROM 1 PM THROUGH 5 PM. SHOWALTER VALUES LOOK TO BE JUST BELOW ZERO...SO SOME ELEVATED INSTABILITY IS POSSIBLE FOR A RUMBLE OR TWO OF THUNDER...BUT NO STRONG/SEVERE STORMS ARE ANTICIPATED DUE TO MEAGER SURFACE BASED INSTABILITY. ONCE THE FRONT GOES THROUGH...THE THREAT FOR SHOWERS WILL DIMINISH GREATLY...AND TEMPS WILL START TO FALL ONCE AGAIN. WITH THE PASSAGE OF THE BOUNDARY...THERE MAY BE A FEW STRONGER GUSTS OF WIND...ESP OVER THE HIGHER TERRAIN. THE BETTER CHANCE FOR STRONG WINDS MAY BE BEHIND THE FRONT...AS COOLER AIR ALOFT ALLOWS FOR BETTER MIXING. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... BEHIND THE COLD FRONT...COOLER AIR ALOFT WILL MOVE INTO THE REGION AS THE STORM STORM LIFTS UP TOWARDS HUDSON BAY CANADA WITH 850 HPA TEMPS DROPPING BACK BELOW FREEZING. GUSTY W-SW WINDS WILL BE IN PLACE FOR TONIGHT. WHILE MOST AREAS WILL STAY DRY...SOME LINGERING CYCLONIC FLOW RAIN/SNOW SHOWERS CANNOT BE TOTALLY RULED OUT FOR UPSLOPE FAVORED AREAS OF THE WESTERN ADIRONDACKS FOR TONIGHT INTO SATURDAY. OTHERWISE...IT WILL REMAIN DRY. MIN TEMPS WILL BE IN THE 20S TONIGHT. GOOD MIXING TOMORROW WILL PROMOTE A MILD DAY...DESPITE BEING BEHIND THE COLD FRONT...WITH HIGHS RANGING FROM THE MID TO UPPER 30S IN THE HIGH TERRAIN TO THE MID TO UPPER 40S FOR VALLEY AREAS. TEMPS LOOK TO DROP BACK DOWN IN THE TEENS AND 20S FOR SAT NIGHT WITH MAINLY DRY WEATHER. THE MODELS SHOW A QUICK MOVING STORM SYSTEM AFFECTING THE REGION AT SOME POINT BETWEEN SUNDAY AND SUNDAY NIGHT. THE TRACK AND TIMING OF THIS SYSTEM REMAINS IN QUESTION...BUT ALL MODELS AGREE THAT ANY QPF WOULD BE VERY LIGHT...AND IT LOOKS TO MOVE THROUGH RATHER QUICKLY. WITH PRECIP ON THE NORTHERN SIDE OF THE SYSTEM...AND WITH EXPECTED COLDER TEMPS ALOFT...MOST OF THE PRECIP SHOULD BE SNOW...PERHAPS MIXING WITH A LITTLE BIT OF RAIN AT TIMES FOR VALLEY AREAS. JUST AN INCH OR TWO OF SNOW LOOKS TO OCCUR. FOR NOW...WILL JUST GO WITH CHC POPS FOR SUN/SUN NIGHT DUE TO UNCERTAINTY REGARDING ITS EXACT TRACK/TIMING. MAX TEMPS WILL BE IN THE 30S...AND MINS SUNDAY NIGHT LOOK TO BE IN THE TEENS/20S. && .LONG TERM /MONDAY THROUGH THURSDAY/... MAINLY DRY AND VERY COLD CONDITIONS ARE EXPECTED FOR MUCH OF THE LONG TERM PERIOD. ANY CHANCES FOR PCPN WILL BE MAINLY TIED TO LAKE EFFECT DOWNWIND OF LAKE ONTARIO ALTHOUGH A WEAK COASTAL LOW PASSES SOUTHEAST OF OUR REGION ON TUESDAY WITH A STRONGER COASTAL LOW FOLLOWING A SIMILAR TRACK ON WEDNESDAY. SINCE THIS SYSTEM LOOKS TO BE STRONGER AND TRACK A LITTLE CLOSER TO OUR REGION WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR NOW. IN ADDITION TO THE VERY COLD AIR IN PLACE ACRS OUR REGION WIND CHILLS MAY REACH ADVISORY CRITERIA WEDNESDAY NIGHT AND THURSDAY ACRS THE HIGHER TERRAIN. THIS WILL BE MENTIONED IN THE HWO. AS FOR TEMPS EXPECT HIGHS ON MONDAY TO RANGE FROM THE UPPER TEENS NORTHWEST TO MID 30S SOUTHEAST WITH HIGHS TUESDAY...WEDNESDAY AND THURSDAY RANGING FROM THE MID TEENS NORTHWEST TO UPPER 20S SOUTHEAST. LOWS MONDAY NIGHT WILL BE IN THE SINGLE DIGITS TO LOWER TEENS WITH LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT MAINLY IN THE 5 BELOW TO 10 ABOVE ZERO RANGE. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... MUCH OF THE RAIN HAS ENDED AT LEAST FOR NOW AT THE TAF SITES WITH THE NEXT BATCH OF RAIN AHEAD OF THE COLD FRONT NOT EXPECTED TO ARRIVE UNTIL EARLY AFTERNOON. THE TAF SITES UP UNTIL THIS TIME ARE EXPECTED TO BE MVFR AT KGFL AND KALB WITH IFR/LIFR CONDITIONS EXPECTED AT KPSF AND KPOU WHERE FOG AND LOW STRATUS WL BE PRESENT. IFR CONDITIONS ARE EXPECTED AT ALL OF THE TAF SITES STARTING ARND 18Z AS THE NEXT BATCH OF RAIN MOVES IN. A COLD FRONT WL SWEEP THROUGH THE RGN LATE THIS AFTERNOON WITH SKIES BECOMING SKC THIS EVENING IN THE WAKE OF THE COLD FRONT. WINDS WILL BE LIGHT AND VARIABLE UNTIL EARLY AFTERNOON AND THEN NE-SE ARND 5 KTS AHD OF THE FRONT AND WEST TO SOUTHWEST AT 6 TO 10 KTS IN THE WAKE OF THE COLD FRONT. OUTLOOK... SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY-SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. MONDAY-MONDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... THE SNOW DEPTH ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW ENGLAND ARE GENERALLY FROM 1 TO 3+ FEET. TEMPERATURES ARE CURRENTLY IN THE LOWER TO MIDDLE 30S...WITH STEADY RAIN AND FREEZING RAIN OCCURRING ACROSS THE NORTHERN HALF OF THE REGION AS A WARM FRONT MOVES ACROSS THE REGION. WITH A SOUTHERLY FLOW DEVELOPING...TEMPERATURES WILL BRIEFLY BE ABOVE NORMAL TODAY...WITH HIGHS IN THE UPPER 30S TO MID 40S...ALONG WITH SOME ADDITIONAL RAIN SHOWERS. HOWEVER...COLDER AIR WILL QUICKLY RETURN BEHIND THIS AFTERNOON/S COLD FRONT...WITH TEMPERATURES DROPPING BACK BELOW FREEZING ACROSS THE ENTIRE REGION BY TONIGHT. STORM TOTAL QPF WILL BE A HALF INCH TO NEARLY ONE AND A HALF INCHES...WITH THE HIGHEST AMOUNTS ACROSS THE ADIRONDACKS. HOWEVER...THIS QPF AND EXPECTED SNOW MELT WILL HAVE A LIMITED RESPONSE ON AREA RIVERS AND STREAMS...AS MUCH OF IT WILL BE ABSORBED BY THE DEEP SNOWPACK. THE LATEST MMEFS...AS WELL AS FORECASTS FROM THE NERFC...DO NOT FORECAST ANY FLOODING OVER THE NEXT DAY OR SO...ALTHOUGH THERE WILL BE SOME RISES ON AREA RIVERS AND STREAMS. DAYTIME TEMPERATURES OVER THE WEEKEND WILL CONTINUE TO BE ABOVE FREEZING...AND OVERNIGHT LOWS WILL DROP BELOW FREEZING. THIS SHOULD ALLOW FOR A STEADY CONTROLLED SNOW MELT...WHICH WILL LIMIT ANY FLOODING CONCERNS. MUCH COLDER WEATHER...WITH TEMPERATURES COMPLETELY BELOW FREEZING...WILL RETURN FOR MUCH OF NEXT WEEK. WE WILL CONTINUE TO MENTION A SLIGHT CHC FOR AN ISOLATED ICE JAM ON SMALLER STREAMS AND CREEK IN THE HWO STATEMENT FOR TODAY INTO TONIGHT DUE TO RAIN MELT AND WARMER TEMPERATURES...BUT WIDESPREAD FLOOD ISSUES ARE NOT ANTICIPATED AT THIS TIME. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ033-041>043-082>084. MA...NONE. VT...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS NEAR TERM...GJM/FRUGIS SHORT TERM...FRUGIS LONG TERM...11 AVIATION...11 HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
729 AM EST FRI FEB 21 2014 .SYNOPSIS... AN APPROACHING WARM FRONT BRINGS PERIODS OF RAIN AND DRIZZLE TO THE AREA THIS MORNING...WITH POCKETS OF FREEZING RAIN TO THE HIGHER TERRAIN. WARMER AIR THEN INVADES CONNECTICUT...RHODE ISLAND AND EASTERN MASSACHUSETTS THIS AFTERNOON ALONG WITH GUSTY SHOWERS...AN ISOLATED THUNDERSTORM AND LOCALLY HEAVY RAINFALL. MILD WEATHER THIS WEEKEND FOLLOWED BY MUCH COLDER WEATHER NEXT WEEK. A PERIOD OF SNOW IS POSSIBLE SUNDAY NIGHT AND AGAIN THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 7 AM UPDATE... LITTLE BREAK IN THE ACTION WITH MAJORITY OF THE WARM ADVECTION PRECIP ACROSS NORTHERN NEW ENGLAND...WITH JUST ONE BAND LEFT ACROSS EASTERN MA. OTHERWISE PRECIP FOR THE REMAINDER OF THIS MORNING INTO EARLY THIS AFTERNOON SHOULD BE MAINLY LIGHT/NUISANCE TYPE DRIZZLE AND/OR SPOTTY LIGHT RAIN. EXPECT COOL CONDITIONS MUCH OF THE DAY WITH WARM SECTOR POSSIBLY PUNCHING INTO RI AND SOUTHEAST MA LATER THIS AFTERNOON. ONLY CHANGE TO THE FORECAST WAS TO HIT A BIT HARDER THE POTENTIAL FOR ELEVATED CONVECTION ALONG AND AHEAD OF APPROACHING COLD FRONT. SPC MESOANALYSIS INDICATES STEEP MID LEVEL LAPSE RATES ADVECTING NORTHWARD FROM THE MID ATLC STATES. THIS COUPLED WITH FRONTAL CONVERGENCE THIS AFTERNOON AND QG FORCING FROM STRONG UPPER LEVEL JET SHOULD BE SUFFICIENT TO INITIATE ELEVATED CONVECTION. PAST FEW RUNS OF HRRR SUPPORT THIS THINKING WITH THIS MODEL SIMULATING AN ORGANIZED FINE LINE OF LOW TOP CONVECTION MOVING ACROSS THE AREA 3 PM TO 7 PM FROM WEST TO EAST. MAIN CONCERN IS IF CONVECTION FIRES SUBTROPICAL MOISTURE PLUME WITH PWATS +3 STD FROM CLIMO YIELDS A RISK OF HEAVY RAINFALL. THIS COMBINED WITH ALREADY SNOW CLOGGED STORM DRAINS MAY RESULT IN WIDESPREAD STREET AND HIGHWAY FLOODING DURING THE LATE DAY COMMUTE. THUS HAVE ISSUED A SPECIAL WEATHER STATEMENT TO HEIGHTEN PUBLIC AWARENESS. FLY IN THE OINTMENT WILL BE IF CONVECTION UPSTREAM ACROSS THE SOUTHEAST STATES ROBS MOISTURE AND INSTABILITY FROM BEING TRANSPORTED NORTHWARD. DAY SHIFT WILL HAVE TO MONITOR THIS. EARLIER DISCUSSION BELOW. ================================================================ 4 AM UPDATE...THE FIRST OF TWO ROUNDS OF PRECIP IS OVER SOUTHERN NEW ENGLAND CURRENTLY...WITH THE HEAVIEST PRECIP IN SOUTHERN NEW HAMPSHIRE. THESE NEXT FEW HOURS WILL BE THE MOST COMPLICATED PART OF THE FORECAST WITH THE SURFACE TEMPERATURES PLAYING SUCH AN IMPORTANT ROLE. TEMPERATURES ACROSS THE AREA ARE HOVERING RIGHT AROUND FREEZING WITH A FEW LOCATIONS BELOW FREEZING AND THE MAJORITY JUST ABOVE. DEWPOINTS ARE ALSO JUST BELOW FREEZING SO ANY HEAVY PRECIPITATION THAT MOVES OVER THOSE AREAS WILL LIKELY BE ENOUGH TO COOL THE TEMPERATURES TO FREEZING OR JUST BELOW. ALOFT THE ATMOSPHERE IS WARM ENOUGH NOW FOR PRECIPITATION TO BE FALLING AS RAIN ACROSS SOUTHERN NEW ENGLAND. THE ONLY QUESTION IS WHETHER THE TEMPERATURES AT THE SURFACE WILL BE ABOVE OR BELOW FREEZING. IN THE AREAS WHERE THE TEMPERATURES ARE BELOW FREEZING OR FALL BELOW FREEZING...ICING WILL BE A CONCERN. NOT EXPECTING MUCH IN THE WAY OF ICING...LESS THAN A TENTH OF AN INCH...BUT EVEN THE LIGHTEST AMOUNTS OF ICING CAN WREAK HAVOC ON TRAVEL. SO WILL LEAVE THE WINTER WEATHER ADVISORY IN PLACE FOR PORTIONS OF MASSACHUSETTS AND SOUTHERN NEW HAMPSHIRE. BY MID-MORNING...TEMPERATURES SHOULD RISE ABOVE FREEZING EVERYWHERE...ALLOWING ANY REMAINING PRECIPITATION TO FALL AS RAIN. AT THIS POINT...THE CONCERN WILL TURN TO HEAVY RAIN AND THUNDER POTENTIAL FOR THE AFTERNOON. A COLD FRONT APPROACHING THE AREA...A STRENGTHENING LOW LEVEL JET...AND STEEPENING MID LEVEL LAPSE RATES SHOULD PROVIDE ENOUGH LIFT AND INSTABILITY FOR A CONVECTIVE LINE OF SHOWERS JUST AHEAD OF THE COLD FRONT. IN ADDITION...PRECIPITABLE WATER VALUES ARE 3 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. SO ANY SHOWERS ARE LIKELY TO PRODUCE BRIEF HEAVY DOWNPOURS AND WITH SNOW CLOGGED DRAINS...EXPECT SOME PONDING OF WATER ON ROADS THIS AFTERNOON. DEPENDING ON THE TIMING OF THE FRONT AND THUS THE SHOWERS AHEAD OF THE FRONT...THERE IS A POSSIBILITY OF SOME THUNDER WITH THE LINE. HAVE KEPT A SLIGHT CHANCE OF THUNDER IN THE GRIDS FOR THIS AFTERNOON. EXPECT THE FRONT TO MOVE THROUGH IN THE LATE AFTERNOON INTO EARLY EVENING. IF IT COMES THROUGH DURING DAYLIGHT...THERE WILL BE THAT INSTABILITY POTENTIAL...IF IT COMES THROUGH LATER AFTER SOME OF THE HEATING FROM THE DAY IS LOST...THUNDER IS LESS LIKELY. DESPITE A RATHER HEFTY LOW LEVEL JET THE WARM AIR ALOFT WILL PREVENT MOST OF THAT ENERGY FROM MIXING TO THE SURFACE. THE EXCEPTION TO THIS WOULD BE IN ANY OF THOSE CONVECTIVE SHOWERS THAT OCCUR. HEAVY RAIN IN THOSE SHOWERS COULD DRAG SOME OF THOSE STRONGER WINDS DOWN TO THE SURFACE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... TONIGHT...AS THE COLD FRONT PUSHES OFFSHORE IT WILL TAKE THE PRECIP WITH IT AND WE WILL BEGIN TO DRY OUT FOR A BIT. EXPECT SKIES TO CLEAR FAIRLY QUICKLY BEHIND THE FRONT WITH MOSTLY CLEAR SKIES FOR MUCH OF THE NIGHT. THE LOW LEVEL JET WILL KEEP WINDS FROM DECOUPLING OVERNIGHT SO WILL NOT HAVE OPTIMAL RADIATIONAL COOLING CONDITIONS. SO TEMPERATURES WILL REMAIN IN THE 20S TO MID 30S. && .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGHLIGHTS... * MILD THIS WEEKEND * ARCTIC AIR RETURNS NEXT WEEK * HIGH AMPLITUDE PATTERN OFFERS A CHANCE OF SNOW SUN NIGHT & AGAIN MIDDLE OF NEXT WEEK THIS WEEKEND... SATURDAY...DRY POST FRONTAL AIRMASS OVERSPREADS THE REGION. HOWEVER AIRMASS IS RELATIVELY MILD WITH 850 TEMPS AROUND -2C AND 925 MB AROUND +4C. BUFKIT SOUNDINGS SUGGEST MIXING TO AROUND 925 MB WILL PROMOTE MAX TEMPS 45-50. HOWEVER A GUSTY SW WIND OF 20-30 MPH WILL PROVIDE A BIT OF A WIND CHILL. NEVERTHELESS PLEASANT BY LATE FEB STANDARDS...ALONG WITH DRY WEATHER PREVAILING. SUNDAY...THE 00Z NAM WAS A STRONG OUTLIER WITH ITS MID LEVEL SHORTWAVE TROUGH. THUS FOLLOWED A BLEND OF THE 00Z ECMWF/GFS AND GEFS SOLUTIONS WHICH SUGGEST A PERIOD OF SNOW POSSIBLE LATE SUN/SUN NIGHT INTO EARLY MON AS A FRONTAL WAVE TRACKS SOUTH OF NEW ENGLAND. ECMWF OFFERS ONLY UP TO A TENTH OF AN INCH OF QPF WHILE THE GFS GENERATES SEVERAL TENTHS. GEFS SIDES WITH THE OPERATIONAL GFS. UPPER AIR PATTERN FAVORS MINOR SNOW ACCUMULATIONS GIVEN THE LACK OF SHORT WAVE AMPLITUDE AND PROGRESSIVE NATURE. NEVERTHELESS A FEW INCHES OF SNOW ARE POSSIBLE LATE SUN INTO EARLY MON. OTHERWISE SUNDAY WILL START OUT DRY AND RELATIVELY MILD...BUT COOLING LATER IN THE DAY AS FRONTAL BOUNDARY SLIPS SOUTHWARD WITH COLD AIR ADVECTION COMMENCING. NEXT WEEK... TEMPERATURES...LOOKS LIKE A COLD STRETCH OF WEATHER WITH THE POLAR FRONT SLIDING SOUTH OF NEW ENGLAND ALL OF NEXT WEEK AS ALL MODEL GUIDANCE /INCLUDING GFS-ECMWF-ECENS-GEFS/ PROJECTING 850 TEMPS OF AROUND -15C /-1 STD FROM CLIMO/ ACROSS THE AREA MON THROUGH WED. COLDER CONDITIONS ARE POSSIBLE LATE NEXT WEEK AS ENSEMBLES AND DETERMINISTIC GUIDANCE HINT AT ANOTHER ARCTIC SURGE ADVECTING INTO THE NORTHEAST WITH 850 TEMPS LOWERING TO -20C TO -25C /-2 STD FROM CLIMO/! PRECIPITATION...DIFFICULT AT THIS RANGE TO TIME WAVES ALONG LEADING AND SECONDARY FRONTAL SURGES NEXT WEEK. HOWEVER ALL MODEL GUIDANCE /AT VARYING DEGREES/ FOCUSES PRECIP CHANCES AROUND MID WEEK WITH CYCLOGENESIS OFF THE MID ATLC COAST. THEN QUESTION BECOMES HOW CLOSE DOES SYSTEM TRACK TO THE COAST. JET ENERGY ASSOCIATED WITH THIS SYSTEM IS CURRENTLY OVER THE ARCTIC...A VERY DATA SPARSE AREA. THUS MODELS WILL NOT CAPTURE THE TRUE AMPLITUDE OF THIS FEATURE UNTIL MON OR TUE WHEN IT TRACKS INTO A MORE DATA RICH AREA OVER SOUTHERN CANADA/NORTHERN ROCKIES. THE UPPER AIR PATTERN DOES FAVOR SOME DEGREE OF EAST COAST STORMINESS WITH A SPLIT FLOW REGIME ACROSS THE WEST COAST WHICH INCLUDES AN ANOMALOUS WESTERN US/CANADA RIDGE EXTENDING INTO AK. OTHERWISE...MUCH OF NEXT WEEK LOOKS COLD AND DRY. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. 7 AM UPDATE... NOT MUCH CHANGE FROM 06Z TAFS. MAIN CONCERN IS HEAVY SHOWERS WITH EMBEDDED TSTMS 3 PM TO 7 PM FROM WEST TO EAST. EARLIER DISCUSSION BELOW. ================================================================= THROUGH 12Z...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN TIMING. SEEING A MIX OF CONDITIONS...MAINLY MVFR/VFR...WITH A FEW PATCHES OF IFR CONDITIONS. GENERALLY GOING TO SEE CONDITIONS DECLINE TOWARDS MORNING WITH DENSE FOG DEVELOPING AS WARM AIR MOVES OVER THE COLD SNOWPACK. IN ADDITION...-SN/FZRA IS POSSIBLE ACROSS S NH AND PARTS OF N MA. TODAY...MVFR/IFR CONDITIONS CONTINUE THROUGH THE DAY WITH FOG SPREADING FARTHER NORTH INTO THE REGION. WINTRY PRECIP COMES TO AN END SHORTLY AFTER 12Z AS TEMPERATURES WARM. HEAVY RAIN AND EVEN SOME THUNDER IS POSSIBLE THIS AFTERNOON AHEAD OF A COLD FRONT. LLWS IS ALSO LIKELY PARTICULARLY ACROSS RI AND SE MA AS LOW LEVEL JET STRENGTHENS OVER THE AREA. TONIGHT...CONDITIONS IMPROVE TO VFR AFTER MIDNIGHT. KBOS TERMINAL...HIGH CONFIDENCE IN TAF TRENDS. KBDL TERMINAL...HIGH CONFIDENCE IN TAF TRENDS. OUTLOOK...SATURDAY THROUGH TUESDAY... VFR LIKELY MUCH OF THIS TIME FRAME. BRIEF MVFR POSSIBLE SUNDAY NIGHT IN A PERIOD OF LIGHT SNOW. MODEST WSW WIND SAT SHIFTS TO WNW SUN/MON AND TUE. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SMALL CRAFT ADVISORIES CONTINUE FOR ALL OF THE COASTAL WATERS EXCEPT BOSTON HARBOR. THESE ARE LARGELY FOR SEAS BUT THERE WILL BE A PERIOD OF TIME THIS AFTERNOON AND EVENING WHEN A COLD FRONT MOVES OVER THE WATERS AND SOUTHERLY WINDS WILL SWITCH TO WESTERLY WINDS AND GUSTS UP TO 25-30 KTS ARE POSSIBLE. VISIBILITIES WILL BE REDUCED AT TIMES IN RAIN AND THERE IS A LOW PROBABILITY OF THUNDER ACCOMPANYING SOME OF THIS RAIN LATER THIS AFTERNOON AND EVENING. OUTLOOK...SATURDAY THROUGH TUESDAY... SAT/SUN...MODEST SW WIND SAT SHIFTS TO WNW SUNDAY. VSBY GOOD BUT MAY LOWER IN SNOW SUNDAY NIGHT. MON/TUE...MODEST WNW WIND ALONG WITH GOOD VSBY. FREEZING SPRAY POSSIBLE AS ARCTIC AIR OVERSPREADS THE WATERS ON A GUSTY WNW WIND. && .HYDROLOGY... SNOW DEPTHS ACROSS MOST OF SOUTHERN NEW ENGLAND RANGE FROM 1 TO 2 FEET...EXCEPT FOR SOMEWHAT LOWER AMOUNTS ALONG SOUTH COASTAL RI AND MA. TEMPERATURES ARE FORECAST TO CLIMB GENERALLY INTO THE 40S TO LOW 50S FRIDAY AND SATURDAY...AND OVERNIGHT LOWS WILL BE CLOSE TO OR BELOW FREEZING. AS A RESULT SOME SNOWMELT WILL OCCUR DURING THE DAYTIME...WITH THE MOST SNOWMELT EXPECTED ACROSS SOUTHEAST MA AND SOUTHERN RI WHERE THE SNOWPACK IS THE MOST DENSE AND THE WARMEST. RAINFALL...0.25 TO 0.35 INCHES OF RAINFALL ARE EXPECTED TODAY. LOCALLY HIGHER AMOUNTS ARE POSSIBLE IF THUNDERSTORMS DEVELOP. THIS WILL LIKELY CAUSE PONDING OF WATER IN LOCATIONS WHERE THERE ARE SNOW CLOGGED DRAINS. THE HEAVIEST SHOWERS WILL LIKELY OCCUR BETWEEN 4 PM AND 8 PM. THIS TIMING MAY IMPACT THE LATE DAY COMMUTE WITH STREET AND HIGHWAY FLOODING. THE COMBINATION RAIN AND SNOWMELT TODAY WILL GIVE SOME AREAS SMALL STREAMS AND RIVERS A BOOST...AND THIS MAY PROMPT ICE MOVEMENT. THERE IS A CHANCE OF ISOLATED ICE JAM DEVELOPMENT TODAY FOR SMALL STREAMS ACROSS CENTRAL INTO WESTERN MA AND NORTHERN CT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR MAZ002>005-008>012-026. NH...FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR NHZ011- 012-015. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR ANZ231>234- 251. SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST SATURDAY FOR ANZ236. SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ250- 254>256. && $$ SYNOPSIS...NOCERA/RLG NEAR TERM...NOCERA/RLG SHORT TERM...RLG LONG TERM...NOCERA AVIATION...NOCERA/RLG MARINE...NOCERA/RLG HYDROLOGY...
AREA FORECAST DISCUSSION
NWS ALBANY NY
621 AM EST FRI FEB 21 2014 .SYNOPSIS... AHEAD OF A COLD FRONT...MILDER AIR WILL MOVE INTO THE REGION FOR TODAY...ALONG WITH RAIN SHOWERS...GUSTY WINDS OVER THE HIGH TERRAIN...AND A SLIGHT CHANCE FOR A THUNDERSTORM. AFTER THE FRONT PASSES THROUGH THE REGION LATE TODAY...THE THREAT FOR RAIN SHOWERS WILL END. DAYTIME TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL INTO THE WEEKEND...BUT MUCH COLDER AIR WILL RETURN TO THE REGION FOR MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 621 AM EST...A STRONG STORM SYSTEM AND POTENT UPPER LEVEL SHORTWAVE IS MOVING ACROSS THE UPPER GREAT LAKES. A WARM FRONT ASSOCIATED WITH THIS STORM IS HAVING A TOUGH TIME MOVING ACROSS OUR REGION...DUE TO PLENTY OF LOW LEVEL COLD AIR IN PLACE THANKS TO A DEEP SNOW PACK. TEMPERATURES CONTINUE TO BE IN THE 30S ACROSS OUR ENTIRE REGION. STEADY PRECIPITATION HAS MOVED NORTH AND EAST OF THE REGION...AS THE BEST ISENTROPIC LIFT/WARM AIR ADVECTION IS NOW FOCUSED ACROSS NORTHERN NEW ENGLAND. WITH TEMPERATURES WARMING THROUGH THE 30S AND MOST OF THE PRECIPITATION DONE...WE/VE CANCELLED THE WINTER WEATHER ADVISORY FOR MOST OF THE AREA. WE WILL CONTINUE IT FOR A LITTLE LONGER FOR THE EASTERN ADIRONDACKS...LAKE GEORGE AREA...AND SRN VT...AS SOME LIGHT PRECIPITATION REMAINS THERE...AND SOME POCKETS OF 30-32 DEGREES ARE STILL OCCURRING ACCORDING TO MESO OBS AT THIS TIME. ONCE TEMPS WARM UP AND PRECIP ENDS...WE SHOULD BE ABLE TO CANCEL THE ADVISORY. AS SHOWN IN THE MODELS...THIS BREAK IN THE PRECIP LOOKS TO CONTINUE THROUGH MUCH OF THE MORNING HOURS. WE HAVE LOWERED POPS TO CHC THROUGH THE MID MORNING HOURS FOR CENTRAL/SOUTHERN PARTS OF THE AREA. HOWEVER...THE MOIST SOUTHERLY FLOW...COMBINED WITH SOME UPSLOPE...MAY ALLOW FOR SOME SPOTTY AREAS OF LIGHT RAIN SHOWERS BY LATER THIS MORNING...SO WE WILL RAISE POPS BACK UP TO LIKELY FOR THE LATE MORNING HOURS. MAX TEMPS SHOULD WARM UP INTO THE LOWER TO MID 40S FOR VALLEY AREAS...WITH UPPER 30S IN THE HIGH TERRAIN WITH THESE HIGHS IN THE LATE MORNING TO EARLY AFTERNOON. THE STORM/S COLD FRONT LOOKS TO MOVE FROM WEST TO EAST DURING THE AFTERNOON HOURS. A STRONGLY FORCED LINE OF SHOWERS...AND POSSIBLY SOME ISOLATED THUNDERSTORMS...WILL MOVE ACROSS THE AREA. THIS IS SEEN IN THE 09Z 3KM HRRR AS WELL...WITH THE TIMING ACROSS OUR AREA BASICALLY FROM 1 PM THROUGH 5 PM. SHOWALTER VALUES LOOK TO BE JUST BELOW ZERO...SO SOME ELEVATED INSTABILITY IS POSSIBLE FOR A RUMBLE OR TWO OF THUNDER...BUT NO STRONG/SEVERE STORMS ARE ANTICIPATED DUE TO MEAGER SURFACE BASED INSTABILITY. ONCE THE FRONT GOES THROUGH...THE THREAT FOR SHOWERS WILL DIMINISH GREATLY...AND TEMPS WILL START TO FALL ONCE AGAIN. WITH THE PASSAGE OF THE BOUNDARY...THERE MAY BE A FEW STRONGER GUSTS OF WIND...ESP OVER THE HIGHER TERRAIN. THE BETTER CHANCE FOR STRONG WINDS MAY BE BEHIND THE FRONT...AS COOLER AIR ALOFT ALLOWS FOR BETTER MIXING. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... BEHIND THE COLD FRONT...COOLER AIR ALOFT WILL MOVE INTO THE REGION AS THE STORM STORM LIFTS UP TOWARDS HUDSON BAY CANADA WITH 850 HPA TEMPS DROPPING BACK BELOW FREEZING. GUSTY W-SW WINDS WILL BE IN PLACE FOR TONIGHT. WHILE MOST AREAS WILL STAY DRY...SOME LINGERING CYCLONIC FLOW RAIN/SNOW SHOWERS CANNOT BE TOTALLY RULED OUT FOR UPSLOPE FAVORED AREAS OF THE WESTERN ADIRONDACKS FOR TONIGHT INTO SATURDAY. OTHERWISE...IT WILL REMAIN DRY. MIN TEMPS WILL BE IN THE 20S TONIGHT. GOOD MIXING TOMORROW WILL PROMOTE A MILD DAY...DESPITE BEING BEHIND THE COLD FRONT...WITH HIGHS RANGING FROM THE MID TO UPPER 30S IN THE HIGH TERRAIN TO THE MID TO UPPER 40S FOR VALLEY AREAS. TEMPS LOOK TO DROP BACK DOWN IN THE TEENS AND 20S FOR SAT NIGHT WITH MAINLY DRY WEATHER. THE MODELS SHOW A QUICK MOVING STORM SYSTEM AFFECTING THE REGION AT SOME POINT BETWEEN SUNDAY AND SUNDAY NIGHT. THE TRACK AND TIMING OF THIS SYSTEM REMAINS IN QUESTION...BUT ALL MODELS AGREE THAT ANY QPF WOULD BE VERY LIGHT...AND IT LOOKS TO MOVE THROUGH RATHER QUICKLY. WITH PRECIP ON THE NORTHERN SIDE OF THE SYSTEM...AND WITH EXPECTED COLDER TEMPS ALOFT...MOST OF THE PRECIP SHOULD BE SNOW...PERHAPS MIXING WITH A LITTLE BIT OF RAIN AT TIMES FOR VALLEY AREAS. JUST AN INCH OR TWO OF SNOW LOOKS TO OCCUR. FOR NOW...WILL JUST GO WITH CHC POPS FOR SUN/SUN NIGHT DUE TO UNCERTAINTY REGARDING ITS EXACT TRACK/TIMING. MAX TEMPS WILL BE IN THE 30S...AND MINS SUNDAY NIGHT LOOK TO BE IN THE TEENS/20S. && .LONG TERM /MONDAY THROUGH THURSDAY/... MAINLY DRY AND VERY COLD CONDITIONS ARE EXPECTED FOR MUCH OF THE LONG TERM PERIOD. ANY CHANCES FOR PCPN WILL BE MAINLY TIED TO LAKE EFFECT DOWNWIND OF LAKE ONTARIO ALTHOUGH A WEAK COASTAL LOW PASSES SOUTHEAST OF OUR REGION ON TUESDAY WITH A STRONGER COASTAL LOW FOLLOWING A SIMILAR TRACK ON WEDNESDAY. SINCE THIS SYSTEM LOOKS TO BE STRONGER AND TRACK A LITTLE CLOSER TO OUR REGION WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR NOW. IN ADDITION TO THE VERY COLD AIR IN PLACE ACRS OUR REGION WIND CHILLS MAY REACH ADVISORY CRITERIA WEDNESDAY NIGHT AND THURSDAY ACRS THE HIGHER TERRAIN. THIS WILL BE MENTIONED IN THE HWO. AS FOR TEMPS EXPECT HIGHS ON MONDAY TO RANGE FROM THE UPPER TEENS NORTHWEST TO MID 30S SOUTHEAST WITH HIGHS TUESDAY...WEDNESDAY AND THURSDAY RANGING FROM THE MID TEENS NORTHWEST TO UPPER 20S SOUTHEAST. LOWS MONDAY NIGHT WILL BE IN THE SINGLE DIGITS TO LOWER TEENS WITH LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT MAINLY IN THE 5 BELOW TO 10 ABOVE ZERO RANGE. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... MUCH OF THE RAIN HAS ENDED AT LEAST FOR NOW AT THE TAF SITES WITH THE NEXT BATCH OF RAIN AHEAD OF THE COLD FRONT NOT EXPECTED TO ARRIVE UNTIL EARLY AFTERNOON. THE TAF SITES UP UNTIL THIS TIME ARE EXPECTED TO BE MVFR AT KGFL AND KALB WITH IFR/LIFR CONDITIONS EXPECTED AT KPSF AND KPOU WHERE FOG AND LOW STRATUS WL BE PRESENT. IFR CONDITIONS ARE EXPECTED AT ALL OF THE TAF SITES STARTING ARND 18Z AS THE NEXT BATCH OF RAIN MOVES IN. A COLD FRONT WL SWEEP THROUGH THE RGN LATE THIS AFTERNOON WITH SKIES BECOMING SKC THIS EVENING IN THE WAKE OF THE COLD FRONT. WINDS WILL BE LIGHT AND VARIABLE UNTIL EARLY AFTERNOON AND THEN NE-SE ARND 5 KTS AHD OF THE FRONT AND WEST TO SOUTHWEST AT 6 TO 10 KTS IN THE WAKE OF THE COLD FRONT. OUTLOOK... SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY-SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. MONDAY-MONDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... THE SNOW DEPTH ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW ENGLAND ARE GENERALLY FROM 1 TO 3+ FEET. TEMPERATURES ARE CURRENTLY IN THE LOWER TO MIDDLE 30S...WITH STEADY RAIN AND FREEZING RAIN OCCURRING ACROSS THE NORTHERN HALF OF THE REGION AS A WARM FRONT MOVES ACROSS THE REGION. WITH A SOUTHERLY FLOW DEVELOPING...TEMPERATURES WILL BRIEFLY BE ABOVE NORMAL TODAY...WITH HIGHS IN THE UPPER 30S TO MID 40S...ALONG WITH SOME ADDITIONAL RAIN SHOWERS. HOWEVER...COLDER AIR WILL QUICKLY RETURN BEHIND THIS AFTERNOON/S COLD FRONT...WITH TEMPERATURES DROPPING BACK BELOW FREEZING ACROSS THE ENTIRE REGION BY TONIGHT. STORM TOTAL QPF WILL BE A HALF INCH TO NEARLY ONE AND A HALF INCHES...WITH THE HIGHEST AMOUNTS ACROSS THE ADIRONDACKS. HOWEVER...THIS QPF AND EXPECTED SNOW MELT WILL HAVE A LIMITED RESPONSE ON AREA RIVERS AND STREAMS...AS MUCH OF IT WILL BE ABSORBED BY THE DEEP SNOWPACK. THE LATEST MMEFS...AS WELL AS FORECASTS FROM THE NERFC...DO NOT FORECAST ANY FLOODING OVER THE NEXT DAY OR SO...ALTHOUGH THERE WILL BE SOME RISES ON AREA RIVERS AND STREAMS. DAYTIME TEMPERATURES OVER THE WEEKEND WILL CONTINUE TO BE ABOVE FREEZING...AND OVERNIGHT LOWS WILL DROP BELOW FREEZING. THIS SHOULD ALLOW FOR A STEADY CONTROLLED SNOW MELT...WHICH WILL LIMIT ANY FLOODING CONCERNS. MUCH COLDER WEATHER...WITH TEMPERATURES COMPLETELY BELOW FREEZING...WILL RETURN FOR MUCH OF NEXT WEEK. WE WILL CONTINUE TO MENTION A SLIGHT CHC FOR AN ISOLATED ICE JAM ON SMALLER STREAMS AND CREEK IN THE HWO STATEMENT FOR TODAY INTO TONIGHT DUE TO RAIN MELT AND WARMER TEMPERATURES...BUT WIDESPREAD FLOOD ISSUES ARE NOT ANTICIPATED AT THIS TIME. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ033-041>043-082>084. MA...NONE. VT...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...11 AVIATION...11 HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
327 AM EST FRI FEB 21 2014 .SYNOPSIS... AHEAD OF A COLD FRONT...MILDER AIR WILL MOVE INTO THE REGION FOR TODAY...ALONG WITH RAIN SHOWERS...GUSTY WINDS OVER THE HIGH TERRAIN...AND A SLIGHT CHANCE FOR A THUNDERSTORM. AFTER THE FRONT PASSES THROUGH THE REGION LATE TODAY...THE THREAT FOR RAIN SHOWERS WILL END. DAYTIME TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL INTO THE WEEKEND...BUT MUCH COLDER AIR WILL RETURN TO THE REGION FOR MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 327 AM EST...A STRONG STORM SYSTEM AND POTENT UPPER LEVEL SHORTWAVE IS MOVING ACROSS THE UPPER GREAT LAKES. A WARM FRONT ASSOCIATED WITH THIS STORM IS HAVING A TOUGH TIME MOVING ACROSS OUR REGION...DUE TO PLENTY OF LOW LEVEL COLD AIR IN PLACE THANKS TO A DEEP SNOW PACK. TEMPERATURES CONTINUE TO BE IN THE LOWER TO MIDDLE 30S ACROSS THE REGION. WITH TEMPS ALOFT WELL ABOVE FREEZING...A BAND OF STEADY RAIN AND /IN AREAS WHERE SURFACE TEMPERATURES REMAIN BELOW FREEZING/ FREEZING RAIN IS MOVING ACROSS THE NORTHERN HALF OF THE AREA DUE TO STRONG ISENTROPIC LIFT/WARM AIR ADVECTION. ALTHOUGH SOME FREEZING RAIN IS STILL OCCURRING IN SHELTERED VALLEYS OF THE ADIRONDACKS AND SRN GREEN MOUNTAINS...SFC TEMPS WILL GRADUALLY WARM UP ABOVE FREEZING ACROSS THE ENTIRE REGION BY THE MID MORNING HOURS. THIS WILL END THE THREAT FOR FREEZING RAIN. UNTIL THEN...AN ADDITIONAL TRACE TO TWO TENTHS OF AN INCH OF ICE WILL BE POSSIBLE FOR THESE ISOLATED AREAS. MOST OTHER LOCATIONS WILL JUST SEE A PLAIN RAIN...BUT WITH TEMPS BARELY ABOVE FREEZING...PLENTY OF SLUSH WILL REMAIN AROUND...AND SOME SURFACES MAY STILL BE ICY OR SLIPPERY DUE TO RECENT SNOW/SLEET FROM LAST EVENING. WINTER WEATHER ADVISORIES REMAIN IN EFFECT FOR NORTHERN PORTIONS OF THE AREA TO ACCOUNT FOR THIS ISOLATED FREEZING RAIN POTENTIAL...BUT SHOULD BE ABLE TO BE CANCELLED/ALLOWED TO EXPIRE LATER THIS MORNING. THERE LOOKS TO BE A BREAK IN THE STEADY PRECIP DURING BETWEEN ABOUT SUNRISE AND EARLY AFTERNOON...AS SEEN IN THE 05Z 3KM HRRR AND 00Z NAM12...AS THE BEST ISENTROPIC LIFT SHIFTS NORTHWARD AND THE STORM/S COLD FRONT CONTINUES TO REMAIN UPSTREAM ACROSS WESTERN NY. HOWEVER...WE WILL STILL KEEP POPS RATHER HIGH FOR THE MORNING...AS SOME LIGHT RAIN SHOWERS OR DRIZZLE MAY BE PASSING THROUGH THE REMAINDER DUE TO THE MOIST SOUTHERLY FLOW...ESP IN UPSLOPE FAVORED AREAS. MAX TEMPS SHOULD WARM UP INTO THE LOWER TO MID 40S FOR VALLEY AREAS...WITH UPPER 30S IN THE HIGH TERRAIN WITH THESE HIGHS IN THE LATE MORNING TO EARLY AFTERNOON. THE STORM/S COLD FRONT LOOKS TO MOVE FROM WEST TO EAST DURING THE AFTERNOON HOURS. A STRONGLY FORCED LINE OF SHOWERS...AND POSSIBLY SOME ISOLATED THUNDERSTORMS...WILL MOVE ACROSS THE AREA. THIS IS SEEN IN THE 3KM HRRR AS WELL...WITH THE TIMING ACROSS OUR AREA BASICALLY FROM 1 PM THROUGH 4 PM. SHOWALTER VALUES LOOK TO BE JUST BELOW ZERO...SO SOME ELEVATED INSTABILITY IS POSSIBLE FOR A RUMBLE OR TWO OF THUNDER...BUT NO STRONG/SEVERE STORMS ARE ANTICIPATED DUE TO MEAGER SURFACE BASED INSTABILITY. ONCE THE FRONT GOES THROUGH...THE THREAT FOR SHOWERS WILL DIMINISH GREATLY...AND TEMPS WILL START TO FALL ONCE AGAIN. WITH THE PASSAGE OF THE BOUNDARY...THERE MAY BE A FEW STRONGER GUSTS OF WIND...ESP OVER THE HIGHER TERRAIN. THE BETTER CHANCE FOR STRONG WINDS MAY BE BEHIND THE FRONT...AS COOLER AIR ALOFT ALLOWS FOR BETTER MIXING. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... BEHIND THE COLD FRONT...COOLER AIR ALOFT WILL MOVE INTO THE REGION AS THE STORM STORM LIFTS UP TOWARDS HUDSON BAY CANADA WITH 850 HPA TEMPS DROPPING BACK BELOW FREEZING. GUSTY W-SW WINDS WILL BE IN PLACE FOR TONIGHT. WHILE MOST AREAS WILL STAY DRY...SOME LINGERING CYCLONIC FLOW RAIN/SNOW SHOWERS CANNOT BE TOTALLY RULED OUT FOR UPSLOPE FAVORED AREAS OF THE WESTERN ADIRONDACKS FOR TONIGHT INTO SATURDAY. OTHERWISE...IT WILL REMAIN DRY. MIN TEMPS WILL BE IN THE 20S TONIGHT. GOOD MIXING TOMORROW WILL PROMOTE A MILD DAY...DESPITE BEING BEHIND THE COLD FRONT...WITH HIGHS RANGING FROM THE MID TO UPPER 30S IN THE HIGH TERRAIN TO THE MID TO UPPER 40S FOR VALLEY AREAS. TEMPS LOOK TO DROP BACK DOWN IN THE TEENS AND 20S FOR SAT NIGHT WITH MAINLY DRY WEATHER. THE MODELS SHOW A QUICK MOVING STORM SYSTEM AFFECTING THE REGION AT SOME POINT BETWEEN SUNDAY AND SUNDAY NIGHT. THE TRACK AND TIMING OF THIS SYSTEM REMAINS IN QUESTION...BUT ALL MODELS AGREE THAT ANY QPF WOULD BE VERY LIGHT...AND IT LOOKS TO MOVE THROUGH RATHER QUICKLY. WITH PRECIP ON THE NORTHERN SIDE OF THE SYSTEM...AND WITH EXPECTED COLDER TEMPS ALOFT...MOST OF THE PRECIP SHOULD BE SNOW...PERHAPS MIXING WITH A LITTLE BIT OF RAIN AT TIMES FOR VALLEY AREAS. JUST AN INCH OR TWO OF SNOW LOOKS TO OCCUR. FOR NOW...WILL JUST GO WITH CHC POPS FOR SUN/SUN NIGHT DUE TO UNCERTAINTY REGARDING ITS EXACT TRACK/TIMING. MAX TEMPS WILL BE IN THE 30S...AND MINS SUNDAY NIGHT LOOK TO BE IN THE TEENS/20S. && .LONG TERM /MONDAY THROUGH THURSDAY/... MAINLY DRY AND VERY COLD CONDITIONS ARE EXPECTED FOR MUCH OF THE LONG TERM PERIOD. ANY CHANCES FOR PCPN WILL BE MAINLY TIED TO LAKE EFFECT DOWNWIND OF LAKE ONTARIO ALTHOUGH A WEAK COASTAL LOW PASSES SOUTHEAST OF OUR REGION ON TUESDAY WITH A STRONGER COASTAL LOW FOLLOWING A SIMILAR TRACK ON WEDNESDAY. SINCE THIS SYSTEM LOOKS TO BE STRONGER AND TRACK A LITTLE CLOSER TO OUR REGION WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR NOW. IN ADDITION TO THE VERY COLD AIR IN PLACE ACRS OUR REGION WIND CHILLS MAY REACH ADVISORY CRITERIA WEDNESDAY NIGHT AND THURSDAY ACRS THE HIGHER TERRAIN. THIS WILL BE MENTIONED IN THE HWO. AS FOR TEMPS EXPECT HIGHS ON MONDAY TO RANGE FROM THE UPPER TEENS NORTHWEST TO MID 30S SOUTHEAST WITH HIGHS TUESDAY...WEDNESDAY AND THURSDAY RANGING FROM THE MID TEENS NORTHWEST TO UPPER 20S SOUTHEAST. LOWS MONDAY NIGHT WILL BE IN THE SINGLE DIGITS TO LOWER TEENS WITH LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT MAINLY IN THE 5 BELOW TO 10 ABOVE ZERO RANGE. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... THE NEXT BATCH OF PCPN IS MOVING QUICKLY EAST INTO THE HUDSON VALLEY AT THIS HOUR. MOST OF THE PCPN WILL BE IN THE FORM OF RAIN WITH POCKETS OF SLEET. THIS WILL RESULT IN MVFR/IFR CONDITIONS FOR MUCH OF THE TAF PERIOD. FRIDAY DURING THE DAY THE PCPN TYPE SHOULD BE ALL RAIN. SOLID IFR/LIFR EXPECTED THROUGH MUCH OF THE DAY ON FRIDAY MORNING DUE TO RELATIVELY WARM/MOIST AIR MOVING OVER A DEEP SNOWPACK. RAIN WILL CONTINUE THROUGH MUCH OF FRIDAY BEFORE A COLD FRONT PASSES THROUGH DURING THE AFTERNOON. WINDS WILL BE SOUTH-SOUTHEAST AROUND 4-8 KT...BECOMING LIGHT AND VARIABLE OVERNIGHT INTO FRIDAY MORNING. WINDS WILL SHIFT TO SOUTHWEST AND WEST LATER FRIDAY AFTERNOON AT 10 KT OR LESS. OUTLOOK... SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY-SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. MONDAY-MONDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... THE SNOW DEPTH ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW ENGLAND ARE GENERALLY FROM 1 TO 3+ FEET. TEMPERATURES ARE CURRENTLY IN THE LOWER TO MIDDLE 30S...WITH STEADY RAIN AND FREEZING RAIN OCCURRING ACROSS THE NORTHERN HALF OF THE REGION AS A WARM FRONT MOVES ACROSS THE REGION. WITH A SOUTHERLY FLOW DEVELOPING...TEMPERATURES WILL BRIEFLY BE ABOVE NORMAL TODAY...WITH HIGHS IN THE UPPER 30S TO MID 40S...ALONG WITH SOME ADDITIONAL RAIN SHOWERS. HOWEVER...COLDER AIR WILL QUICKLY RETURN BEHIND THIS AFTERNOON/S COLD FRONT...WITH TEMPERATURES DROPPING BACK BELOW FREEZING ACROSS THE ENTIRE REGION BY TONIGHT. STORM TOTAL QPF WILL BE A HALF INCH TO NEARLY ONE AND A HALF INCHES...WITH THE HIGHEST AMOUNTS ACROSS THE ADIRONDACKS. HOWEVER...THIS QPF AND EXPECTED SNOW MELT WILL HAVE A LIMITED RESPONSE ON AREA RIVERS AND STREAMS...AS MUCH OF IT WILL BE ABSORBED BY THE DEEP SNOWPACK. THE LATEST MMEFS...AS WELL AS FORECASTS FROM THE NERFC...DO NOT FORECAST ANY FLOODING OVER THE NEXT DAY OR SO...ALTHOUGH THERE WILL BE SOME RISES ON AREA RIVERS AND STREAMS. DAYTIME TEMPERATURES OVER THE WEEKEND WILL CONTINUE TO BE ABOVE FREEZING...AND OVERNIGHT LOWS WILL DROP BELOW FREEZING. THIS SHOULD ALLOW FOR A STEADY CONTROLLED SNOW MELT...WHICH WILL LIMIT ANY FLOODING CONCERNS. MUCH COLDER WEATHER...WITH TEMPERATURES COMPLETELY BELOW FREEZING...WILL RETURN FOR MUCH OF NEXT WEEK. WE WILL CONTINUE TO MENTION A SLIGHT CHC FOR AN ISOLATED ICE JAM ON SMALLER STREAMS AND CREEK IN THE HWO STATEMENT FOR TODAY INTO TONIGHT DUE TO RAIN MELT AND WARMER TEMPERATURES...BUT WIDESPREAD FLOOD ISSUES ARE NOT ANTICIPATED AT THIS TIME. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ033-039>043-048>050-082>084. WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR NYZ032-038-047-051>054. MA...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR MAZ001-025. VT...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR VTZ013>015. && $$ SYNOPSIS...FRUGIS NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...11 AVIATION...11 HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
110 PM EST FRI FEB 21 2014 UPDATE... A LINE OF SHOWERS AND TSTMS FROM SWAINSBORO TO LUMBER CITY CONTINUES MOVING EAST THROUGH THE REMAINDER OF THE FFC FORECAST AREA. MOST OF THE FFC GA COUNTIES HAVE BEEN REMOVED FROM THE SVR TSTM WATCH 22. THE REMAINING THREE COUNTIES WILL BE REMOVED BY 1100 PM EST. THE COLD FRONT EXTENDING FROM WARRENTON TO CORDELE WILL EXIT THE FORECAST AREA BY EARLY AFTERNOON. RAPID CLEARING WILL CONTINUE ACROSS NORTH AND CENTRAL GEORGIA THROUGH THE DAY. 16 PREV DISCUSSION... /ISSUED 650 AM EST FRI FEB 21 2014/ PREV DISCUSSION... /ISSUED 504 AM EST FRI FEB 21 2014/ UPDATE... AFD UPDATE TO REFRESH FFC WATCH/WARNING/ADVISORY SECTION BELOW. PREV DISCUSSION... /ISSUED 322 AM EST FRI FEB 21 2014/ SHORT TERM /TODAY THROUGH SATURDAY/... MAIN FORECAST CONCERN THROUGH THE SHORT TERM CONTINUES TO BE THE COLD FRONT PUSHING INTO NORTHWEST GEORGIA THIS MORNING. OVERALL MODELS STILL CONSISTENT WITH THE TIMING OF THE SYSTEM THROUGH THE AREA...AND FORECAST IS SKEWED TOWARDS HRRR AND LOCAL WRF FOR TIMING OF THE FRONT PUSHING OUT OF THE CWA. ANTICIPATE THE BULK OF THE ACTIVITY TO BE THROUGH THE ATL AREA 08-11Z...AND THROUGH THE MCN AREA BY 11-13Z. SEVERE POTENTIAL ENOUGH TO ISSUE SVR TSTM WATCH THROUGH SUNRISE. NAM CONTINUES TO ADVERTISE THE HIGHER MUCAPE VALUES...WITH THE GFS STILL AROUND 300-400J/KG AND MODELED LOW LEVEL SHEAR STILL IN THE 45-50KT RANGE. OVERALL THE TORNADO THREAT IS MARGINAL AND IS EXPECTED GRADUALLY LESSON THROUGH THE EARLY MORNING HOURS. THAT BEING SAID...AN ISOLATED TORNADO CAN NOT BE RULED OUT ENTIRELY. A TORNADO WATCH CONTINUES THROUGH 10Z FOR NORTHERN PORTIONS OF THE CWA. THE MAIN CONCERN CONTINUES TO BE THE DAMAGING WINDS ASSOCIATED WITH THE LINE GIVEN THE SUFFICIENT WIND SHEAR AND INSTABILITY. SOME ROTATION HAS BEEN NOTED /ALBEIT BROAD/ IN THESE STORMS AS THEY HAVE MOVED INTO THE STATE. AS THE STORMS MOVE THROUGH...THE THREAT OF SEVERE ACTIVITY DROPS OFF QUICKLY. LIGHT RAIN SHOWERS WILL PERSIST BEHIND THE MAIN LINE FOR A FEW HOURS BEFORE CLEARING BEGINS. WINDS ASSOCIATED WITH THE LINE WILL ALSO DIMINISH INTO THE DAYLIGHT HOURS. GUSTY WINDS AHEAD OF THE FRONT AND THE DAMAGING WINDS EMBEDDED WITHIN THE CONVECTION COULD BRING DOWN ALREADY WEAKENED TREES ESPECIALLY VULNERABLE FROM THE RECENT ICE STORM. QPF OF 1-1.25 INCHES WITH LOCALLY HIGHER AMOUNTS ACROSS NORTHWEST GEORGIA COULD RESULT IN QUICKLY RISING CREEKS AND RIVERS. BEHIND THE FRONT...HIGH PRESSURE BUILDING INTO THE REGION WILL KEEP THE REMAINDER OF THE SHORT TERM DRY. LOOKING FOR HIGHS IN THE 60S FRIDAY AND SATURDAY...WITH LOWS IN THE 30S SATURDAY MORNING. 31 LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE OVERALL ACTIVE PATTERN CONTINUES INTO THE EXTENDED PERIOD. MODELS CONTINUE TO SHOW NEARLY ZONAL FLOW ACROSS THE AREA INTO THE LONG TERM. A WEAK UPPER LEVEL DISTURBANCE WITHIN THIS ZONAL FLOW INTERACTS WITH AN OLD FRONTAL BOUNDARY ACROSS THE SOUTHERN PORTION OF THE STATE. AS A RESULT...HAVE CONTINUED WITH THE SLIGHT CHANCE TO CHANCE POPS SUNDAY...WITH THE BEST CHANCES FARTHER SOUTH. A REINFORCING COLD FRONT PUSHES ACROSS THE AREA SUNDAY NIGHT INTO MONDAY...WITH A DRY AND COOLER AIR MASS RETURNING TO THE STATE MONDAY. BY MID WEEK...WEAK FRONTAL BOUNDARY MEANDERING ACROSS THE STATE INTERACTS WITH THE FLOW ALOFT...BUT MODEL UNCERTAINTY STILL HIGH ENOUGH TO JUST CONTINUE WITH SLIGHT CHANCES OF SHOWERS. WITH LIMITED INSTABILITY AND WIND SHEAR...HAVE CONTINUED TO LEAVE OUT MENTION OF THUNDERSTORMS AT THIS TIME. 39 && AVIATION... 18Z UPDATE... SMALL AREA OF IFR/MVFR CEILINGS IN THE SOUTHEAST CORNER OF THE FORECAST AREA AT THIS TIME...WELL SOUTHEAST OF THE TAF SITES...WILL IMPROVE TO VFR BY 20Z WITH VFR CONDITIONS EXPECTED AREAWIDE THROUGH THE REMAINDER OF THIS FORECAST PERIOD. COLD FRONT HAS CLEARED THE FORECAST AREA WITH NORTHWEST WINDS EXPECTED TO CONTINUE AREAWIDE THROUGH 12-15Z SATURDAY...BECOMING NORTHEASTERLY AND EVENTUALLY SOUTHEASTERLY 15-00Z. WIND SPEEDS REMAIN 8-14KTS CURRENTLY WITH FREQUENT GUSTS 15-23KT BUT WILL CONTINUE TO DIMINISH...DROPPING TO 6-8KT BY 00Z AND 2-5KT BY 00Z. WIND SPEEDS WILL INCREASE AFTER 12Z SATURDAY...REACHING 4-8KT BY 18Z. ATL CONFIDENCE...18Z UPDATE... HIGH. 20 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 62 36 68 40 / 50 5 5 10 ATLANTA 61 39 66 43 / 10 5 5 10 BLAIRSVILLE 57 32 63 36 / 10 5 5 10 CARTERSVILLE 59 32 66 38 / 5 5 5 10 COLUMBUS 63 39 67 41 / 10 5 5 20 GAINESVILLE 61 38 65 40 / 10 5 5 10 MACON 65 34 68 40 / 60 5 5 10 ROME 59 31 65 36 / 5 5 5 10 PEACHTREE CITY 61 30 66 36 / 10 5 5 10 VIDALIA 70 45 70 46 / 100 10 5 10 && .FFC WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 2 PM EST THIS AFTERNOON FOR THE FOLLOWING ZONES: EMANUEL...MONTGOMERY...TOOMBS. && $$ SHORT TERM...20 LONG TERM....16 AVIATION...20
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1026 AM EST FRI FEB 21 2014 UPDATE... A LINE OF SHOWERS AND TSTMS FROM SWAINSBORO TO LUMBER CITY CONTINUES MOVING EAST THROUGH THE REMAINDER OF THE FFC FORECAST AREA. MOST OF THE FFC GA COUNTIES HAVE BEEN REMOVED FROM THE SVR TSTM WATCH 22. THE REMAINING THREE COUNTIES WILL BE REMOVED BY 1100 PM EST. THE COLD FRONT EXTENDING FROM WARRENTON TO CORDELE WILL EXIT THE FORECAST AREA BY EARLY AFTERNOON. RAPID CLEARING WILL CONTINUE ACROSS NORTH AND CENTRAL GEORGIA THROUGH THE DAY. 16 PREV DISCUSSION... /ISSUED 650 AM EST FRI FEB 21 2014/ PREV DISCUSSION... /ISSUED 504 AM EST FRI FEB 21 2014/ UPDATE... AFD UPDATE TO REFRESH FFC WATCH/WARNING/ADVISORY SECTION BELOW. PREV DISCUSSION... /ISSUED 322 AM EST FRI FEB 21 2014/ SHORT TERM /TODAY THROUGH SATURDAY/... MAIN FORECAST CONCERN THROUGH THE SHORT TERM CONTINUES TO BE THE COLD FRONT PUSHING INTO NORTHWEST GEORGIA THIS MORNING. OVERALL MODELS STILL CONSISTENT WITH THE TIMING OF THE SYSTEM THROUGH THE AREA...AND FORECAST IS SKEWED TOWARDS HRRR AND LOCAL WRF FOR TIMING OF THE FRONT PUSHING OUT OF THE CWA. ANTICIPATE THE BULK OF THE ACTIVITY TO BE THROUGH THE ATL AREA 08-11Z...AND THROUGH THE MCN AREA BY 11-13Z. SEVERE POTENTIAL ENOUGH TO ISSUE SVR TSTM WATCH THROUGH SUNRISE. NAM CONTINUES TO ADVERTISE THE HIGHER MUCAPE VALUES...WITH THE GFS STILL AROUND 300-400J/KG AND MODELED LOW LEVEL SHEAR STILL IN THE 45-50KT RANGE. OVERALL THE TORNADO THREAT IS MARGINAL AND IS EXPECTED GRADUALLY LESSON THROUGH THE EARLY MORNING HOURS. THAT BEING SAID...AN ISOLATED TORNADO CAN NOT BE RULED OUT ENTIRELY. A TORNADO WATCH CONTINUES THROUGH 10Z FOR NORTHERN PORTIONS OF THE CWA. THE MAIN CONCERN CONTINUES TO BE THE DAMAGING WINDS ASSOCIATED WITH THE LINE GIVEN THE SUFFICIENT WIND SHEAR AND INSTABILITY. SOME ROTATION HAS BEEN NOTED /ALBEIT BROAD/ IN THESE STORMS AS THEY HAVE MOVED INTO THE STATE. AS THE STORMS MOVE THROUGH...THE THREAT OF SEVERE ACTIVITY DROPS OFF QUICKLY. LIGHT RAIN SHOWERS WILL PERSIST BEHIND THE MAIN LINE FOR A FEW HOURS BEFORE CLEARING BEGINS. WINDS ASSOCIATED WITH THE LINE WILL ALSO DIMINISH INTO THE DAYLIGHT HOURS. GUSTY WINDS AHEAD OF THE FRONT AND THE DAMAGING WINDS EMBEDDED WITHIN THE CONVECTION COULD BRING DOWN ALREADY WEAKENED TREES ESPECIALLY VULNERABLE FROM THE RECENT ICE STORM. QPF OF 1-1.25 INCHES WITH LOCALLY HIGHER AMOUNTS ACROSS NORTHWEST GEORGIA COULD RESULT IN QUICKLY RISING CREEKS AND RIVERS. BEHIND THE FRONT...HIGH PRESSURE BUILDING INTO THE REGION WILL KEEP THE REMAINDER OF THE SHORT TERM DRY. LOOKING FOR HIGHS IN THE 60S FRIDAY AND SATURDAY...WITH LOWS IN THE 30S SATURDAY MORNING. 31 LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE OVERALL ACTIVE PATTERN CONTINUES INTO THE EXTENDED PERIOD. MODELS CONTINUE TO SHOW NEARLY ZONAL FLOW ACROSS THE AREA INTO THE LONG TERM. A WEAK UPPER LEVEL DISTURBANCE WITHIN THIS ZONAL FLOW INTERACTS WITH AN OLD FRONTAL BOUNDARY ACROSS THE SOUTHERN PORTION OF THE STATE. AS A RESULT...HAVE CONTINUED WITH THE SLIGHT CHANCE TO CHANCE POPS SUNDAY...WITH THE BEST CHANCES FARTHER SOUTH. A REINFORCING COLD FRONT PUSHES ACROSS THE AREA SUNDAY NIGHT INTO MONDAY...WITH A DRY AND COOLER AIR MASS RETURNING TO THE STATE MONDAY. BY MID WEEK...WEAK FRONTAL BOUNDARY MEANDERING ACROSS THE STATE INTERACTS WITH THE FLOW ALOFT...BUT MODEL UNCERTAINTY STILL HIGH ENOUGH TO JUST CONTINUE WITH SLIGHT CHANCES OF SHOWERS. WITH LIMITED INSTABILITY AND WIND SHEAR...HAVE CONTINUED TO LEAVE OUT MENTION OF THUNDERSTORMS AT THIS TIME. 39 AVIATION... 12Z UPDATE... AREA OF SHOWERS AND THUNDERSTORMS HAS ALMOST PUSHED EAST OF THE ATL METRO TAF SITES. EXPECT IT TO CLEAR THE AHN...CSG...AND MCN AREAS BY 14Z. GUSTY NW WINDS WILL CONTINUE THROUGH MID MORNING...THEN EXPECT SUSTAINED 8-12KT. WINDS DIMINISH OVERNIGHT. VFR CONDITIONS BY THE AFTERNOON. ATL CONFIDENCE...12Z UPDATE... LOW CONFIDENCE ON CIGS THROUGH 14Z...OTHERWISE HIGH CONFIDENCE. 31 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 62 36 68 40 / 50 5 5 10 ATLANTA 61 39 66 43 / 10 5 5 10 BLAIRSVILLE 57 32 63 36 / 10 5 5 10 CARTERSVILLE 59 32 66 38 / 5 5 5 10 COLUMBUS 63 39 67 41 / 10 5 5 20 GAINESVILLE 61 38 65 40 / 10 5 5 10 MACON 65 34 68 40 / 60 5 5 10 ROME 59 31 65 36 / 5 5 5 10 PEACHTREE CITY 61 30 66 36 / 10 5 5 10 VIDALIA 70 45 70 46 / 100 10 5 10 && .FFC WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 2 PM EST THIS AFTERNOON FOR THE FOLLOWING ZONES: EMANUEL...MONTGOMERY...TOOMBS. && $$ SHORT TERM...20 LONG TERM....16 AVIATION...20
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1006 AM EST FRI FEB 21 2014 .SYNOPSIS... HIGH PRESSURE WILL RETREAT EASTWARD TONIGHT IN ADVANCE OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL SWEEP THROUGH THE AREA ON FRIDAY...STALLING JUST OFFSHORE UNTIL STRONGER HIGH PRESSURE BUILDS INTO THE AREA ON MONDAY. A LOW PRESSURE SYSTEM COULD DEVELOP OFF THE SOUTHEAST COAST LATE TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... MORNING UPDATE...THE LINE OF THUNDERSTORMS HAS MOVED INTO THE FAR INLAND COUNTIES. WARNINGS WILL BE ISSUED WITH MORE CAUTION SINCE A LOT OF AREAS ARE MORE SUSCEPTIBLE TO WIND DAMAGE FROM THE RECENT ICE STORM. RECENT TRENDS HAVE SHOWN A DECREASE IN LIGHTNING AS PRECIPITABLE ECHOES ARE HOVERING NEAR OR BELOW 20K FT. SPC RUC MESOANALYSIS INDICATES THAT CAPE VALUES ARE RANGING FROM 100 TO 500 J/KG...SO INSTABILITY IS STILL SOMEWHAT LACKING RIGHT NOW. EXPECT THAT TO CHANGE AS THE DAY GOES ON AS SURFACE HEATING AND FORCING INCREASES. UNTIL THEN...THE MAIN THREAT WILL BE STRONG TO SEVERE WINDS AND ISOLATED TORNADOES. DAMAGE WAS CONFIRMED NEAR DUBLIN IN LAURENS COUNTY WEST OF US. 6KM SHEAR WILL HOLD STEADY AT NEARLY 45KTS...SO WE COULD SEE SOME BOWING SEGMENTS. IN TERMS OF TIMING...ROUGH ESTIMATES ARE THAT THE LINE WILL BE NEAR SAV AT 16Z AND CHS BY 17Z. MOST AREAS COULD SEE CLOSE TO 1.5 INCHES OF RAIN ACCUMULATION WITH THE MORE INTENSE CELLS. TEMPERATURES WILL HOLD STEADY IN THE LOW 70S TODAY FOR AREAS AHEAD OF THE COLD FRONT. WITH FROPA...TEMPS COULD DROP 10 DEGREES. PREVIOUS DISCUSSION...A STRONG MID LEVEL SHORT WAVE RIDING BELOW THE LARGE/DEEP CLOSED UPPER LOW OVER THE GREAT LAKES WAS IMPRESSIVE EARLY THIS MORNING ON WATER VAPOR SATELLITE IMAGERY. THIS FEATURE WILL DIG THE MEAN UPPER TROUGH THROUGH THE TENNESSEE/OHIO VALLEYS THIS MORNING THEN LIFT TOWARD NEW ENGLAND LATE TODAY. SUBTLE NEGATIVE TILTING APPEARS TO BE STRONGER OFF TO THE NORTH OF OUR FORECAST AREA THROUGH MID AFTERNOON. ONGOING TRENDS THIS MORNING HAVE INCREASED OUR CONCERNS FOR SEVERE WEATHER POTENTIAL IN THE PRE-FRONTAL ENVIRONMENT THROUGH MID AFTERNOON. THE FIRST...OBVIOUSLY THE MUCH WARMER THAN GUIDANCE READINGS THAT HAVE BECOME ROOTED ACROSS SE GEORGIA AND EASTERN SOUTH CAROLINA EARLY THIS MORNING BEFORE DAYBREAK. ALTHOUGH TIMING OF THE CONVECTIVE LINE THROUGH THE FORECAST AREA REMAINS FAIRLY CONSISTENT FROM PREVIOUS MODEL RUNS TODAY...IT IS NOT GOING TO TAKE MUCH TO ALLOW TEMPS TO RISE WARMER INTO THE LOWER TO MID 70S THIS MORNING. UPSTREAM CONVECTION OVERNIGHT HAS BEEN QUITE ROBUST WITH THE LATEST RAP SHOWING SURFACE BASED INSTABILITY INTO SW GEORGIA WITH SBCAPES OVER 750 J/KG AT 08Z. SOME OF FORECAST AREAS COULD SEE SOME THINNER CLOUDS THROUGH MID MORNING AS DENSE CLOUD COVER WILL BE COMING IN LATER IN THE MORNING. SPC HAS OUR REGION IN A SLIGHT RISK OF SEVERE CONVECTION AND THERE APPEARS TO BE NO REASON TO DOUBT IT PER LATEST MESOSCALE TRENDS. 00Z HIGH RESOLUTION GUIDANCE INDICATING POTENTIAL FOR HIGHER DBZ CORES AND LINEAR ORGANIZATION. GIVEN THE STRONG WIND FIELDS...SMALL BOWS WOULD BE A CONCERN ALONG WITH POSSIBLE FORMATION OF A DECENT REAR INFLOW JET. CONCERN FALLS OVER OUR NW TIER OF ZONES THAT SUFFERED GREAT TIMBER DAMAGE FROM THE RECENT ICE STORM. TSTM GUST IMPACTS COULD CERTAINLY BE MUCH GREATER IN THOSE ZONES WHERE WEAK AND BROKEN LIMBS ALREADY LACE THAT REGION. EVEN A MARGINALLY GUSTY SQUALL LINE COULD MAKE FOR SOME BAD TIMES IN SOME AREAS AND WE WILL REMAIN COGNIZANT OF THIS SITUATION. WE WILL RAMP UP SEVERE WORDING A BIT IN OUR HAZARDOUS WEATHER OUTLOOK THIS MORNING ALTHOUGH IT IS STILL MORE LIKELY THAT WE ONLY SEE ONLY SEE ISOLATED OCCURRENCES OF 50 KT CONVECTIVE WIND GUSTS IN THE CONVECTIVE SEGMENTS/LINES AS TIMING AND STRENGTH OF DYNAMICS DO NOT APPEAR TO COMPLETELY COME IN SYNC FOR A MORE WIDESPREAD EVENT. THE COLD FRONT WILL RACE THROUGH THE FORECAST AREA THIS AFTERNOON AND OFFSHORE BY EARLY EVENING. MUCH COOLER TEMPS EXPECTED TONIGHT WITH LOWS IN THE 40S AND GRADUALLY CLEARING SKIES. && .SHORT TERM /SATURDAY THROUGH MONDAY/... DRY HIGH PRESSURE WILL SETTLE OVER THE REGION ON SATURDAY. AMPLE MOISTURE WITHIN A 105 KT JET OVER THE DEEP SOUTH WILL PRODUCE EXTENSIVE CIRRUS WHICH WILL SLIGHTLY LIMIT INSOLATION. HOWEVER HIGH TEMPS WILL STILL REACH 70F IN MANY SPOTS. ON SUNDAY WE START TO SEE SOME CHANNELED VORTICITY ENERGY MOVE INTO THE EASTERN UNITED STATES. MEANWHILE THE LOW-LEVEL RIDGE OVER THE WESTERN ATLANTIC STARTS TO SHIFT EAST AS THE FLOW BACKS TO SOUTHWESTERLY. AS LOW-LEVEL MOISTURE INCREASES...WEAK ISENTROPIC ASCENT WILL DEVELOP ACROSS SOUTHEAST GA WITH SOME RAIN SHOWERS POSSIBLE BY SUNDAY AFTERNOON. WE ADDED A SLIGHT CHANCE OF TSTMS ACROSS FAR SOUTHERN AREAS BECAUSE A POCKET OF ELEVATED INSTABILITY SHIFTS THROUGH DURING THIS TIME. LOW-LEVEL WARM ADVECTION WILL PUSH HIGH TEMPS INTO THE LOWER TO MIDDLE 70S. A BACKDOOR COLD FRONT WILL DROP INTO THE AREA SUNDAY NIGHT AND PUSH OFFSHORE ON MONDAY. UPPER DYNAMICS ARE NOT VERY IMPRESSIVE ACCOMPANYING THE FROPA SO WE ONLY HAVE 20-40 POPS SUNDAY NIGHT. ON MONDAY...SLIGHTLY COOLER HIGH PRESSURE WILL BUILD IN FROM THE NORTH WHILE THE BACKDOOR FRONT SITS JUST SOUTH OF THE AREA. EXTENSIVE CLOUD COVER WILL ALSO PERSIST THOUGH THE BEST RAIN CHANCES WILL BE FAR SOUTH CLOSER TO THE FRONT. WE SHOW HIGH TEMPS IN THE MID/UPPER 60S. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... THE LONG TERM PATTERN WILL MAINLY BE DOMINATED BY A LOBE OF THE POLAR VORTEX MOVING INTO THE GREAT LAKES REGION LATE WEEK. MONDAY NIGHT THROUGH WEDNESDAY THE UPPER PATTERN WILL BE TRENDING TOWARD A BROAD TROUGH REGIME WITH A SERIES OF WEAK FRONTS AND LOW PRESSURE WAVES AFFECTING THE FORECAST AREA. DUE TO LARGE UNCERTAINTIES IN TIMING INDIVIDUAL FEATURES WE MAINTAINED A CONSERVATIVE FORECAST WITH MAINLY SLIGHT CHANCES FOR SHOWERS AND HIGH TEMPS IN THE 60S. A STRONG COLD FRONT WILL SWEEP THROUGH WEDNESDAY NIGHT... FOLLOWED BY COOL CANADIAN HIGH PRESSURE THURSDAY AND FRIDAY. THIS WILL BRING DRY CONDITIONS AND BELOW-NORMAL TEMPERATURES. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... PRIOR TO THE RAINS TODAY...GUSTY SW SURFACE WINDS AHEAD OF THE SQUALL LINE ALONG WITH FAIRLY WIDESPREAD MVFR CIGS. THERE COULD BE A BRIEF BOUT OF IFR CIGS BUT THE WINDOW LOOKS FAIRLY BRIEF. ADDED THUNDER TO THE TAFS WITH THE LINE EXPECTED TO BE OVER KSAV AROUND 16Z AND KCHS AT 17Z. THERE IS NOT A LOT OF LIGHTNING WITH THIS LINE...BUT THAT COULD CHANGE AS INSTABILITY INCREASES. SKIES WILL BEGIN TO CLEAR OUT THIS EVENING WITH VFR CONDITIONS EXPECTED TONIGHT IN THE WAKE OF A COLD FRONT. EXTENDED AVIATION OUTLOOK...MVFR CEILINGS POSSIBLE AT KSAV SATURDAY NIGHT AND AT BOTH TERMINALS SUNDAY NIGHT INTO MONDAY MORNING. OTHERWISE VFR. && .MARINE... A SEVERE TSTM WATCH IS IN EFFECT FOR NEAR SHORE WATERS AND THE CHARLESTON HARBOR. OTHERWISE...NOT MUCH MIXING GOING ON OVER CHILLY SHELF WATERS AND IT IS INTERESTING TO SEE WINDS GUSTS TO 20 KT AT TIMES AT CHARLESTON AND SAVANNAH WHERE TEMPS HAVE WARMED TO THE UPPER 60S. TEMPS AT GRAYS REEF NEAR 60 AND WINDS BELOW 10 KT ALL NIGHT WITH 2-3 FT SEAS...QUITE THE STRONG MARINE INVERSION. SEAS WILL CONTINUE TO BUILD OFFSHORE AND MAINTAINED A MARGINAL SCA FOR CHARLESTON COUNTY WATERS MAINLY WELL EAST OF BULLS BAY. MOST NEAR SHORE WATERS TODAY WILL SEE SW WINDS 15 KT OR SO AND SEAS 3-4 FT TOPS. THERE IS ALSO A SCA FOR OUR OUTER GEORGIA WATERS WITH OCCASIONALLY GUSTY SW FLOW AND SEAS 4-7 FT...HIGHEST NEAR THE WEST WALL OF THE GULF STREAM. THE FRONT MOVES THROUGH THIS EVENING WITH WINDS SHIFTING W OR WNW TONIGHT WITH COLD AIR ADVECTION MORE GRADUAL THAN SHARP...CONDITIONS BELOW SCA CRITERIA. MARINE WINDS/SEAS WILL BE RATHER LIGHT SATURDAY THROUGH SUNDAY BEFORE A COLD FRONT DROPS INTO THE WATER SUNDAY NIGHT. WINDS WILL INCREASE ALONG THE FRONT BUT THE STRONGER SURGE COMES MONDAY AS THE FLOW BECOMES NE. CONDITIONS COULD FLIRT WITH ADVISORY LEVELS... ESPECIALLY MONDAY NIGHT WHEN SEAS COME UP SOME. THE NEXT SURGE COMES WEDNESDAY AND WEDNESDAY NIGHT BEHIND A STRONG COLD FRONT. MODERATE CHANCES FOR SMALL CRAFT ADVISORIES WITH THE MID-WEEK SYSTEM. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ350- 374. && $$ SYNOPSIS...JRL NEAR TERM...BDC SHORT TERM...JRL LONG TERM...JRL AVIATION...BDC MARINE...BDC/JRL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
759 AM EST FRI FEB 21 2014 .UPDATE... LINE OF CONVECTION/PRECIPITATION PROGRESSING QUICKLY ACROSS THE FORECAST AREA. HAVE BEEN ABLE TO CLEAR SV.A 21. SV.A 22 REMAINS IN EFFECT UNTIL 2 PM...HOWEVER THE PORTION IN OUR FORECAST AREA WILL LIKELY BE CLEAR OF CONVECTION BY LATE MORNING AT THE CURRENT PACE. POP AND SKY GRIDS LOOK GOOD WITH RESPECT TO CURRENT RADAR/SATELLITE TRENDS SO NO MAJOR CHANGES PLANNED TO THE CURRENT GRIDS AT THIS TIME. 20 && .PREV DISCUSSION... /ISSUED 650 AM EST FRI FEB 21 2014/ PREV DISCUSSION... /ISSUED 504 AM EST FRI FEB 21 2014/ UPDATE... AFD UPDATE TO REFRESH FFC WATCH/WARNING/ADVISORY SECTION BELOW. PREV DISCUSSION... /ISSUED 322 AM EST FRI FEB 21 2014/ SHORT TERM /TODAY THROUGH SATURDAY/... MAIN FORECAST CONCERN THROUGH THE SHORT TERM CONTINUES TO BE THE COLD FRONT PUSHING INTO NORTHWEST GEORGIA THIS MORNING. OVERALL MODELS STILL CONSISTENT WITH THE TIMING OF THE SYSTEM THROUGH THE AREA...AND FORECAST IS SKEWED TOWARDS HRRR AND LOCAL WRF FOR TIMING OF THE FRONT PUSHING OUT OF THE CWA. ANTICIPATE THE BULK OF THE ACTIVITY TO BE THROUGH THE ATL AREA 08-11Z...AND THROUGH THE MCN AREA BY 11-13Z. SEVERE POTENTIAL ENOUGH TO ISSUE SVR TSTM WATCH THROUGH SUNRISE. NAM CONTINUES TO ADVERTISE THE HIGHER MUCAPE VALUES...WITH THE GFS STILL AROUND 300-400J/KG AND MODELED LOW LEVEL SHEAR STILL IN THE 45-50KT RANGE. OVERALL THE TORNADO THREAT IS MARGINAL AND IS EXPECTED GRADUALLY LESSON THROUGH THE EARLY MORNING HOURS. THAT BEING SAID...AN ISOLATED TORNADO CAN NOT BE RULED OUT ENTIRELY. A TORNADO WATCH CONTINUES THROUGH 10Z FOR NORTHERN PORTIONS OF THE CWA. THE MAIN CONCERN CONTINUES TO BE THE DAMAGING WINDS ASSOCIATED WITH THE LINE GIVEN THE SUFFICIENT WIND SHEAR AND INSTABILITY. SOME ROTATION HAS BEEN NOTED /ALBEIT BROAD/ IN THESE STORMS AS THEY HAVE MOVED INTO THE STATE. AS THE STORMS MOVE THROUGH...THE THREAT OF SEVERE ACTIVITY DROPS OFF QUICKLY. LIGHT RAIN SHOWERS WILL PERSIST BEHIND THE MAIN LINE FOR A FEW HOURS BEFORE CLEARING BEGINS. WINDS ASSOCIATED WITH THE LINE WILL ALSO DIMINISH INTO THE DAYLIGHT HOURS. GUSTY WINDS AHEAD OF THE FRONT AND THE DAMAGING WINDS EMBEDDED WITHIN THE CONVECTION COULD BRING DOWN ALREADY WEAKENED TREES ESPECIALLY VULNERABLE FROM THE RECENT ICE STORM. QPF OF 1-1.25 INCHES WITH LOCALLY HIGHER AMOUNTS ACROSS NORTHWEST GEORGIA COULD RESULT IN QUICKLY RISING CREEKS AND RIVERS. BEHIND THE FRONT...HIGH PRESSURE BUILDING INTO THE REGION WILL KEEP THE REMAINDER OF THE SHORT TERM DRY. LOOKING FOR HIGHS IN THE 60S FRIDAY AND SATURDAY...WITH LOWS IN THE 30S SATURDAY MORNING. 31 LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE OVERALL ACTIVE PATTERN CONTINUES INTO THE EXTENDED PERIOD. MODELS CONTINUE TO SHOW NEARLY ZONAL FLOW ACROSS THE AREA INTO THE LONG TERM. A WEAK UPPER LEVEL DISTURBANCE WITHIN THIS ZONAL FLOW INTERACTS WITH AN OLD FRONTAL BOUNDARY ACROSS THE SOUTHERN PORTION OF THE STATE. AS A RESULT...HAVE CONTINUED WITH THE SLIGHT CHANCE TO CHANCE POPS SUNDAY...WITH THE BEST CHANCES FARTHER SOUTH. A REINFORCING COLD FRONT PUSHES ACROSS THE AREA SUNDAY NIGHT INTO MONDAY...WITH A DRY AND COOLER AIR MASS RETURNING TO THE STATE MONDAY. BY MID WEEK...WEAK FRONTAL BOUNDARY MEANDERING ACROSS THE STATE INTERACTS WITH THE FLOW ALOFT...BUT MODEL UNCERTAINTY STILL HIGH ENOUGH TO JUST CONTINUE WITH SLIGHT CHANCES OF SHOWERS. WITH LIMITED INSTABILITY AND WIND SHEAR...HAVE CONTINUED TO LEAVE OUT MENTION OF THUNDERSTORMS AT THIS TIME. 39 && AVIATION... 12Z UPDATE... AREA OF SHOWERS AND THUNDERSTORMS HAS ALMOST PUSHED EAST OF THE ATL METRO TAF SITES. EXPECT IT TO CLEAR THE AHN...CSG...AND MCN AREAS BY 14Z. GUSTY NW WINDS WILL CONTINUE THROUGH MID MORNING...THEN EXPECT SUSTAINED 8-12KT. WINDS DIMINISH OVERNIGHT. VFR CONDITIONS BY THE AFTERNOON. ATL CONFIDENCE...12Z UPDATE... LOW CONFIDENCE ON CIGS THROUGH 14Z...OTHERWISE HIGH CONFIDENCE. 31 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 63 36 68 40 / 100 5 5 10 ATLANTA 61 39 66 43 / 70 5 5 10 BLAIRSVILLE 57 32 63 36 / 60 5 5 10 CARTERSVILLE 61 32 66 38 / 40 5 5 10 COLUMBUS 63 39 67 41 / 80 5 5 20 GAINESVILLE 62 38 65 40 / 70 5 5 10 MACON 64 34 68 40 / 100 5 5 10 ROME 60 31 65 36 / 20 5 5 10 PEACHTREE CITY 61 30 66 36 / 70 5 5 10 VIDALIA 68 45 70 46 / 100 10 5 10 && .FFC WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 2 PM EST THIS AFTERNOON FOR THE FOLLOWING ZONES: BALDWIN...BLECKLEY...DODGE...EMANUEL... GLASCOCK...HANCOCK...JEFFERSON...JOHNSON...LAURENS... MONTGOMERY...PULASKI...TALIAFERRO...TELFAIR...TOOMBS... TREUTLEN...TWIGGS...WARREN...WASHINGTON...WHEELER...WILCOX... WILKES...WILKINSON. && $$ SHORT TERM...20 LONG TERM....BDL AVIATION...20
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
716 AM EST FRI FEB 21 2014 .SYNOPSIS... HIGH PRESSURE WILL RETREAT EASTWARD TONIGHT IN ADVANCE OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL SWEEP THROUGH THE AREA ON FRIDAY...STALLING JUST OFFSHORE UNTIL STRONGER HIGH PRESSURE BUILDS INTO THE AREA ON MONDAY. A LOW PRESSURE SYSTEM COULD DEVELOP OFF THE SOUTHEAST COAST LATE TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... NEAR DAWN...FAIRLY ORGANIZED LINE OF CONVECTION MOVING IN FROM THE WEST OVER EAST CENTRAL GEORGIA. A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR OUR ENTIRE FORECAST AREA AS TSTMS EXPECTED TO MOVE THROUGH AT A DECENT CLIP. LATEST SPC RUC MESOANALYSIS INDICATES MODERATE INSTABILITY BETWEEN 500 MB AND 700 MB WITH LAPSE RATES OF -6.5C. THE LINE WILL BE MOVING INTO A SLIGHTLY LESS FAVORABLE ENVIRONMENT OVER OUR INLAND GEORGIA ZONES IN THE NEXT COUPLE OF HOURS...HOWEVER MUCH BETTER INSTABILITY IN PLACE OVER SE SOUTH CAROLINA WITH SB LIFTED INDICES OF -3. LATEST HRRR FORECAST CONVECTION PROGS SUGGEST SHOWERS AND STORMS COVERAGE AND INTENSITY COULD INCREASE AFTER 15Z...THEN NEAR THE COAST AROUND MIDDAY. A STRONG MID LEVEL SHORT WAVE RIDING BELOW THE LARGE/DEEP CLOSED UPPER LOW OVER THE GREAT LAKES WAS IMPRESSIVE EARLY THIS MORNING ON WATER VAPOR SATELLITE IMAGERY. THIS FEATURE WILL DIG THE MEAN UPPER TROUGH THROUGH THE TENNESSEE/OHIO VALLEYS THIS MORNING THEN LIFT TOWARD NEW ENGLAND LATE TODAY. SUBTLE NEGATIVE TILTING APPEARS TO BE STRONGER OFF TO THE NORTH OF OUR FORECAST AREA THROUGH MID AFTERNOON. ONGOING TRENDS THIS MORNING HAVE INCREASED OUR CONCERNS FOR SEVERE WEATHER POTENTIAL IN THE PRE-FRONTAL ENVIRONMENT THROUGH MID AFTERNOON. THE FIRST...OBVIOUSLY THE MUCH WARMER THAN GUIDANCE READINGS THAT HAVE BECOME ROOTED ACROSS SE GEORGIA AND EASTERN SOUTH CAROLINA EARLY THIS MORNING BEFORE DAYBREAK. ALTHOUGH TIMING OF THE CONVECTIVE LINE THROUGH THE FORECAST AREA REMAINS FAIRLY CONSISTENT FROM PREVIOUS MODEL RUNS TODAY...IT IS NOT GOING TO TAKE MUCH TO ALLOW TEMPS TO RISE WARMER INTO THE LOWER TO MID 70S THIS MORNING. UPSTREAM CONVECTION OVERNIGHT HAS BEEN QUITE ROBUST WITH THE LATEST RAP SHOWING SURFACE BASED INSTABILITY INTO SW GEORGIA WITH SBCAPES OVER 750 J/KG AT 08Z. SOME OF FORECAST AREAS COULD SEE SOME THINNER CLOUDS THROUGH MID MORNING AS DENSE CLOUD COVER WILL BE COMING IN LATER IN THE MORNING. SPC HAS OUR REGION IN A SLIGHT RISK OF SEVERE CONVECTION AND THERE APPEARS TO BE NO REASON TO DOUBT IT PER LATEST MESOSCALE TRENDS. 00Z HIGH RESOLUTION GUIDANCE INDICATING POTENTIAL FOR HIGHER DBZ CORES AND LINEAR ORGANIZATION. GIVEN THE STRONG WIND FIELDS...SMALL BOWS WOULD BE A CONCERN ALONG WITH POSSIBLE FORMATION OF A DECENT REAR INFLOW JET. CONCERN FALLS OVER OUR NW TIER OF ZONES THAT SUFFERED GREAT TIMBER DAMAGE FROM THE RECENT ICE STORM. TSTM GUST IMPACTS COULD CERTAINLY BE MUCH GREATER IN THOSE ZONES WHERE WEAK AND BROKEN LIMBS ALREADY LACE THAT REGION. EVEN A MARGINALLY GUSTY SQUALL LINE COULD MAKE FOR SOME BAD TIMES IN SOME AREAS AND WE WILL REMAIN COGNIZANT OF THIS SITUATION. WE WILL RAMP UP SEVERE WORDING A BIT IN OUR HAZARDOUS WEATHER OUTLOOK THIS MORNING ALTHOUGH IT IS STILL MORE LIKELY THAT WE ONLY SEE ONLY SEE ISOLATED OCCURRENCES OF 50 KT CONVECTIVE WIND GUSTS IN THE CONVECTIVE SEGMENTS/LINES AS TIMING AND STRENGTH OF DYNAMICS DO NOT APPEAR TO COMPLETELY COME IN SYNC FOR A MORE WIDESPREAD EVENT. THE COLD FRONT WILL RACE THROUGH THE FORECAST AREA THIS AFTERNOON AND OFFSHORE BY EARLY EVENING. MUCH COOLER TEMPS EXPECTED TONIGHT WITH LOWS IN THE 40S AND GRADUALLY CLEARING SKIES. && .SHORT TERM /SATURDAY THROUGH MONDAY/... DRY HIGH PRESSURE WILL SETTLE OVER THE REGION ON SATURDAY. AMPLE MOISTURE WITHIN A 105 KT JET OVER THE DEEP SOUTH WILL PRODUCE EXTENSIVE CIRRUS WHICH WILL SLIGHTLY LIMIT INSOLATION. HOWEVER HIGH TEMPS WILL STILL REACH 70F IN MANY SPOTS. ON SUNDAY WE START TO SEE SOME CHANNELED VORTICITY ENERGY MOVE INTO THE EASTERN UNITED STATES. MEANWHILE THE LOW-LEVEL RIDGE OVER THE WESTERN ATLANTIC STARTS TO SHIFT EAST AS THE FLOW BACKS TO SOUTHWESTERLY. AS LOW-LEVEL MOISTURE INCREASES...WEAK ISENTROPIC ASCENT WILL DEVELOP ACROSS SOUTHEAST GA WITH SOME RAIN SHOWERS POSSIBLE BY SUNDAY AFTERNOON. WE ADDED A SLIGHT CHANCE OF TSTMS ACROSS FAR SOUTHERN AREAS BECAUSE A POCKET OF ELEVATED INSTABILITY SHIFTS THROUGH DURING THIS TIME. LOW-LEVEL WARM ADVECTION WILL PUSH HIGH TEMPS INTO THE LOWER TO MIDDLE 70S. A BACKDOOR COLD FRONT WILL DROP INTO THE AREA SUNDAY NIGHT AND PUSH OFFSHORE ON MONDAY. UPPER DYNAMICS ARE NOT VERY IMPRESSIVE ACCOMPANYING THE FROPA SO WE ONLY HAVE 20-40 POPS SUNDAY NIGHT. ON MONDAY...SLIGHTLY COOLER HIGH PRESSURE WILL BUILD IN FROM THE NORTH WHILE THE BACKDOOR FRONT SITS JUST SOUTH OF THE AREA. EXTENSIVE CLOUD COVER WILL ALSO PERSIST THOUGH THE BEST RAIN CHANCES WILL BE FAR SOUTH CLOSER TO THE FRONT. WE SHOW HIGH TEMPS IN THE MID/UPPER 60S. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... THE LONG TERM PATTERN WILL MAINLY BE DOMINATED BY A LOBE OF THE POLAR VORTEX MOVING INTO THE GREAT LAKES REGION LATE WEEK. MONDAY NIGHT THROUGH WEDNESDAY THE UPPER PATTERN WILL BE TRENDING TOWARD A BROAD TROUGH REGIME WITH A SERIES OF WEAK FRONTS AND LOW PRESSURE WAVES AFFECTING THE FORECAST AREA. DUE TO LARGE UNCERTAINTIES IN TIMING INDIVIDUAL FEATURES WE MAINTAINED A CONSERVATIVE FORECAST WITH MAINLY SLIGHT CHANCES FOR SHOWERS AND HIGH TEMPS IN THE 60S. A STRONG COLD FRONT WILL SWEEP THROUGH WEDNESDAY NIGHT... FOLLOWED BY COOL CANADIAN HIGH PRESSURE THURSDAY AND FRIDAY. THIS WILL BRING DRY CONDITIONS AND BELOW-NORMAL TEMPERATURES. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... EARLIER CONCERNS WITH FOG HAS TURNED TO CONCERN FOR STRONG CONVECTION MOVING INTO THE COASTAL CORRIDOR AFTER MID MORNING AND THEN EXITING PRIOR TO MID AFTERNOON. PRIOR TO THE RAINS TODAY...GUSTY SW SURFACE WINDS WERE DEVELOPING AHEAD OF THE SQUALL LINE ALONG WITH FAIRLY WIDESPREAD MVFR CIGS. THERE COULD BE A BRIEF BOUT OF IFR CIGS BUT THE WINDOW LOOKS FAIRLY BRIEF. STILL A BIT EARLY TO COMMIT TSRA AS THE LINE COULD BE PREDOMINATELY MORE SHALLOW...HOWEVER WE BELIEVE THUNDER WILL HAVE TO BE ADDED AT SOME POINT BY MID MORNING GIVEN RADAR TRENDS. SKIES WILL BEGIN TO CLEAR OUT THIS EVENING WITH VFR CONDITIONS EXPECTED TONIGHT IN THE WAKE OF A COLD FRONT. EXTENDED AVIATION OUTLOOK...MVFR CEILINGS POSSIBLE AT KSAV SATURDAY NIGHT AND AT BOTH TERMINALS SUNDAY NIGHT INTO MONDAY MORNING. OTHERWISE VFR. && .MARINE... LITTLE TO NO REPORTS OF DENSE SEA FOG OVERNIGHT ALONG THE COAST WITH SATELLITE IMAGERY ALSO NOT SUPPORTING OF FOG BASED LOW STRATUS OFF THE COAST. THERE STILL IS A CHANCE FOR SEA FOG BUT GIVEN LATEST TRENDS WE OPTED TO CANCEL MARINE FOG ADVISORIES AND JUST FORECAST PATCHY DENSE FOG OVER THE WATERS THROUGH EARLY AFTERNOON WHEN RAIN CHANCES INCREASE AND THE COLD FRONT NEARS. A SEVERE TSTM WATCH IS IN EFFECT FOR NEAR SHORE WATERS AND THE CHARLESTON HARBOR. OTHERWISE...NOT MUCH MIXING GOING ON OVER CHILLY SHELF WATERS AND IT IS INTERESTING TO SEE WINDS GUSTS TO 20 KT AT TIMES AT CHARLESTON AND SAVANNAH WHERE TEMPS HAVE WARMED TO THE UPPER 60S. TEMPS AT GRAYS REEF NEAR 60 AND WINDS BELOW 10 KT ALL NIGHT WITH 2-3 FT SEAS...QUITE THE STRONG MARINE INVERSION. SEAS WILL CONTINUE TO BUILD OFFSHORE AND MAINTAINED A MARGINAL SCA FOR CHARLESTON COUNTY WATERS MAINLY WELL EAST OF BULLS BAY. MOST NEAR SHORE WATERS TODAY WILL SEE SW WINDS 15 KT OR SO AND SEAS 3-4 FT TOPS. THERE IS ALSO A SCA FOR OUR OUTER GEORGIA WATERS WITH OCCASIONALLY GUSTY SW FLOW AND SEAS 4-7 FT...HIGHEST NEAR THE WEST WALL OF THE GULF STREAM. THE FRONT MOVES THROUGH THIS EVENING WITH WINDS SHIFTING W OR WNW TONIGHT WITH COLD AIR ADVECTION MORE GRADUAL THAN SHARP...CONDITIONS BELOW SCA CRITERIA. MARINE WINDS/SEAS WILL BE RATHER LIGHT SATURDAY THROUGH SUNDAY BEFORE A COLD FRONT DROPS INTO THE WATER SUNDAY NIGHT. WINDS WILL INCREASE ALONG THE FRONT BUT THE STRONGER SURGE COMES MONDAY AS THE FLOW BECOMES NE. CONDITIONS COULD FLIRT WITH ADVISORY LEVELS... ESPECIALLY MONDAY NIGHT WHEN SEAS COME UP SOME. THE NEXT SURGE COMES WEDNESDAY AND WEDNESDAY NIGHT BEHIND A STRONG COLD FRONT. MODERATE CHANCES FOR SMALL CRAFT ADVISORIES WITH THE MID-WEEK SYSTEM. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ350- 374. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE...JRL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
650 AM EST FRI FEB 21 2014 .PREV DISCUSSION... /ISSUED 504 AM EST FRI FEB 21 2014/ UPDATE... AFD UPDATE TO REFRESH FFC WATCH/WARNING/ADVISORY SECTION BELOW. PREV DISCUSSION... /ISSUED 322 AM EST FRI FEB 21 2014/ SHORT TERM /TODAY THROUGH SATURDAY/... MAIN FORECAST CONCERN THROUGH THE SHORT TERM CONTINUES TO BE THE COLD FRONT PUSHING INTO NORTHWEST GEORGIA THIS MORNING. OVERALL MODELS STILL CONSISTENT WITH THE TIMING OF THE SYSTEM THROUGH THE AREA...AND FORECAST IS SKEWED TOWARDS HRRR AND LOCAL WRF FOR TIMING OF THE FRONT PUSHING OUT OF THE CWA. ANTICIPATE THE BULK OF THE ACTIVITY TO BE THROUGH THE ATL AREA 08-11Z...AND THROUGH THE MCN AREA BY 11-13Z. SEVERE POTENTIAL ENOUGH TO ISSUE SVR TSTM WATCH THROUGH SUNRISE. NAM CONTINUES TO ADVERTISE THE HIGHER MUCAPE VALUES...WITH THE GFS STILL AROUND 300-400J/KG AND MODELED LOW LEVEL SHEAR STILL IN THE 45-50KT RANGE. OVERALL THE TORNADO THREAT IS MARGINAL AND IS EXPECTED GRADUALLY LESSON THROUGH THE EARLY MORNING HOURS. THAT BEING SAID...AN ISOLATED TORNADO CAN NOT BE RULED OUT ENTIRELY. A TORNADO WATCH CONTINUES THROUGH 10Z FOR NORTHERN PORTIONS OF THE CWA. THE MAIN CONCERN CONTINUES TO BE THE DAMAGING WINDS ASSOCIATED WITH THE LINE GIVEN THE SUFFICIENT WIND SHEAR AND INSTABILITY. SOME ROTATION HAS BEEN NOTED /ALBEIT BROAD/ IN THESE STORMS AS THEY HAVE MOVED INTO THE STATE. AS THE STORMS MOVE THROUGH...THE THREAT OF SEVERE ACTIVITY DROPS OFF QUICKLY. LIGHT RAIN SHOWERS WILL PERSIST BEHIND THE MAIN LINE FOR A FEW HOURS BEFORE CLEARING BEGINS. WINDS ASSOCIATED WITH THE LINE WILL ALSO DIMINISH INTO THE DAYLIGHT HOURS. GUSTY WINDS AHEAD OF THE FRONT AND THE DAMAGING WINDS EMBEDDED WITHIN THE CONVECTION COULD BRING DOWN ALREADY WEAKENED TREES ESPECIALLY VULNERABLE FROM THE RECENT ICE STORM. QPF OF 1-1.25 INCHES WITH LOCALLY HIGHER AMOUNTS ACROSS NORTHWEST GEORGIA COULD RESULT IN QUICKLY RISING CREEKS AND RIVERS. BEHIND THE FRONT...HIGH PRESSURE BUILDING INTO THE REGION WILL KEEP THE REMAINDER OF THE SHORT TERM DRY. LOOKING FOR HIGHS IN THE 60S FRIDAY AND SATURDAY...WITH LOWS IN THE 30S SATURDAY MORNING. 31 LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE OVERALL ACTIVE PATTERN CONTINUES INTO THE EXTENDED PERIOD. MODELS CONTINUE TO SHOW NEARLY ZONAL FLOW ACROSS THE AREA INTO THE LONG TERM. A WEAK UPPER LEVEL DISTURBANCE WITHIN THIS ZONAL FLOW INTERACTS WITH AN OLD FRONTAL BOUNDARY ACROSS THE SOUTHERN PORTION OF THE STATE. AS A RESULT...HAVE CONTINUED WITH THE SLIGHT CHANCE TO CHANCE POPS SUNDAY...WITH THE BEST CHANCES FARTHER SOUTH. A REINFORCING COLD FRONT PUSHES ACROSS THE AREA SUNDAY NIGHT INTO MONDAY...WITH A DRY AND COOLER AIR MASS RETURNING TO THE STATE MONDAY. BY MID WEEK...WEAK FRONTAL BOUNDARY MEANDERING ACROSS THE STATE INTERACTS WITH THE FLOW ALOFT...BUT MODEL UNCERTAINTY STILL HIGH ENOUGH TO JUST CONTINUE WITH SLIGHT CHANCES OF SHOWERS. WITH LIMITED INSTABILITY AND WIND SHEAR...HAVE CONTINUED TO LEAVE OUT MENTION OF THUNDERSTORMS AT THIS TIME. 39 && .AVIATION... 12Z UPDATE... AREA OF SHOWERS AND THUNDERSTORMS HAS ALMOST PUSHED EAST OF THE ATL METRO TAF SITES. EXPECT IT TO CLEAR THE AHN...CSG...AND MCN AREAS BY 14Z. GUSTY NW WINDS WILL CONTINUE THROUGH MID MORNING...THEN EXPECT SUSTAINED 8-12KT. WINDS DIMINISH OVERNIGHT. VFR CONDITIONS BY THE AFTERNOON. //ATL CONFIDENCE...12Z UPDATE... LOW CONFIDENCE ON CIGS THROUGH 14Z...OTHERWISE HIGH CONFIDENCE. 31 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 63 36 68 40 / 90 5 5 10 ATLANTA 61 39 66 43 / 70 5 5 10 BLAIRSVILLE 57 32 63 36 / 60 5 5 10 CARTERSVILLE 61 32 66 38 / 40 5 5 10 COLUMBUS 63 39 67 41 / 80 5 5 20 GAINESVILLE 62 38 65 40 / 70 5 5 10 MACON 64 34 68 40 / 100 5 5 10 ROME 60 31 65 36 / 20 5 5 10 PEACHTREE CITY 61 30 66 36 / 70 5 5 10 VIDALIA 68 45 70 46 / 90 10 5 10 && .FFC WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 2 PM EST THIS AFTERNOON FOR THE FOLLOWING ZONES: BALDWIN...BLECKLEY...DODGE...EMANUEL... GLASCOCK...HANCOCK...JEFFERSON...JOHNSON...LAURENS... MONTGOMERY...PULASKI...TALIAFERRO...TELFAIR...TOOMBS... TREUTLEN...TWIGGS...WARREN...WASHINGTON...WHEELER...WILCOX... WILKES...WILKINSON. SEVERE THUNDERSTORM WATCH UNTIL 9 AM EST THIS MORNING FOR THE FOLLOWING ZONES: BIBB...CRAWFORD...CRISP...DOOLY...GREENE... HOUSTON...JASPER...JONES...MACON...MARION...MONROE...MORGAN... OGLETHORPE...PEACH...PUTNAM...SCHLEY...STEWART...SUMTER... TAYLOR...WEBSTER. && $$ SHORT TERM...31 LONG TERM....39 AVIATION...31
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
504 AM EST FRI FEB 21 2014 .UPDATE... AFD UPDATE TO REFRESH FFC WATCH/WARNING/ADVISORY SECTION BELOW. && .PREV DISCUSSION... /ISSUED 322 AM EST FRI FEB 21 2014/ SHORT TERM /TODAY THROUGH SATURDAY/... MAIN FORECAST CONCERN THROUGH THE SHORT TERM CONTINUES TO BE THE COLD FRONT PUSHING INTO NORTHWEST GEORGIA THIS MORNING. OVERALL MODELS STILL CONSISTENT WITH THE TIMING OF THE SYSTEM THROUGH THE AREA...AND FORECAST IS SKEWED TOWARDS HRRR AND LOCAL WRF FOR TIMING OF THE FRONT PUSHING OUT OF THE CWA. ANTICIPATE THE BULK OF THE ACTIVITY TO BE THROUGH THE ATL AREA 08-11Z...AND THROUGH THE MCN AREA BY 11-13Z. SEVERE POTENTIAL ENOUGH TO ISSUE SVR TSTM WATCH THROUGH SUNRISE. NAM CONTINUES TO ADVERTISE THE HIGHER MUCAPE VALUES...WITH THE GFS STILL AROUND 300-400J/KG AND MODELED LOW LEVEL SHEAR STILL IN THE 45-50KT RANGE. OVERALL THE TORNADO THREAT IS MARGINAL AND IS EXPECTED GRADUALLY LESSON THROUGH THE EARLY MORNING HOURS. THAT BEING SAID...AN ISOLATED TORNADO CAN NOT BE RULED OUT ENTIRELY. A TORNADO WATCH CONTINUES THROUGH 10Z FOR NORTHERN PORTIONS OF THE CWA. THE MAIN CONCERN CONTINUES TO BE THE DAMAGING WINDS ASSOCIATED WITH THE LINE GIVEN THE SUFFICIENT WIND SHEAR AND INSTABILITY. SOME ROTATION HAS BEEN NOTED /ALBEIT BROAD/ IN THESE STORMS AS THEY HAVE MOVED INTO THE STATE. AS THE STORMS MOVE THROUGH...THE THREAT OF SEVERE ACTIVITY DROPS OFF QUICKLY. LIGHT RAIN SHOWERS WILL PERSIST BEHIND THE MAIN LINE FOR A FEW HOURS BEFORE CLEARING BEGINS. WINDS ASSOCIATED WITH THE LINE WILL ALSO DIMINISH INTO THE DAYLIGHT HOURS. GUSTY WINDS AHEAD OF THE FRONT AND THE DAMAGING WINDS EMBEDDED WITHIN THE CONVECTION COULD BRING DOWN ALREADY WEAKENED TREES ESPECIALLY VULNERABLE FROM THE RECENT ICE STORM. QPF OF 1-1.25 INCHES WITH LOCALLY HIGHER AMOUNTS ACROSS NORTHWEST GEORGIA COULD RESULT IN QUICKLY RISING CREEKS AND RIVERS. BEHIND THE FRONT...HIGH PRESSURE BUILDING INTO THE REGION WILL KEEP THE REMAINDER OF THE SHORT TERM DRY. LOOKING FOR HIGHS IN THE 60S FRIDAY AND SATURDAY...WITH LOWS IN THE 30S SATURDAY MORNING. 31 LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE OVERALL ACTIVE PATTERN CONTINUES INTO THE EXTENDED PERIOD. MODELS CONTINUE TO SHOW NEARLY ZONAL FLOW ACROSS THE AREA INTO THE LONG TERM. A WEAK UPPER LEVEL DISTURBANCE WITHIN THIS ZONAL FLOW INTERACTS WITH AN OLD FRONTAL BOUNDARY ACROSS THE SOUTHERN PORTION OF THE STATE. AS A RESULT...HAVE CONTINUED WITH THE SLIGHT CHANCE TO CHANCE POPS SUNDAY...WITH THE BEST CHANCES FARTHER SOUTH. A REINFORCING COLD FRONT PUSHES ACROSS THE AREA SUNDAY NIGHT INTO MONDAY...WITH A DRY AND COOLER AIR MASS RETURNING TO THE STATE MONDAY. BY MID WEEK...WEAK FRONTAL BOUNDARY MEANDERING ACROSS THE STATE INTERACTS WITH THE FLOW ALOFT...BUT MODEL UNCERTAINTY STILL HIGH ENOUGH TO JUST CONTINUE WITH SLIGHT CHANCES OF SHOWERS. WITH LIMITED INSTABILITY AND WIND SHEAR...HAVE CONTINUED TO LEAVE OUT MENTION OF THUNDERSTORMS AT THIS TIME. 39 AVIATION... 06Z UPDATE... LINE OF SHOWERS AND THUNDERSTORMS EXPECTED TO MOVE THROUGH THE AREA OVERNIGHT...WITH DEGRADING CIGS AND VSBYS ACCOMPANYING THE TSRA. HAVE TIMED THE SQUALL LINE THROUGH THE ATL AREA BY 10Z...AND THE MCN AND AHN AREAS BY AROUND 12Z. S-SW GUSTY WINDS /15G25KT OR SO/ WILL BECOME NW AT 13-15KT GUSTS TO 22-25KT BEHIND THE LINE. EXPECT HIGH IFR OR LOW MVFR CIGS WITH THE POST-TSRA LIGHT RAIN...WITH SLOW IMPROVEMENT THROUGH FRIDAY MORNING...AND VFR BY AFTERNOON. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE ON ALL ELEMENTS. 31 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 63 36 68 40 / 90 5 5 10 ATLANTA 61 39 66 43 / 70 5 5 10 BLAIRSVILLE 57 32 63 36 / 60 5 5 10 CARTERSVILLE 61 32 66 38 / 40 5 5 10 COLUMBUS 63 39 67 41 / 80 5 5 20 GAINESVILLE 62 38 65 40 / 70 5 5 10 MACON 64 34 68 40 / 100 5 5 10 ROME 60 31 65 36 / 20 5 5 10 PEACHTREE CITY 61 30 66 36 / 70 5 5 10 VIDALIA 68 45 70 46 / 90 10 5 10 && .FFC WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 9 AM EST THIS MORNING FOR THE FOLLOWING ZONES: BARROW...BIBB...BUTTS...CARROLL... CHATTAHOOCHEE...CLARKE...CLAYTON...COBB...COWETA...CRAWFORD... CRISP...DEKALB...DOOLY...DOUGLAS...FAYETTE...GREENE...GWINNETT... HARALSON...HARRIS...HEARD...HENRY...HOUSTON...JASPER...JONES... LAMAR...MACON...MARION...MERIWETHER...MONROE...MORGAN... MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE... PAULDING...PEACH...PIKE...POLK...PUTNAM...ROCKDALE...SCHLEY... SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...TAYLOR... TROUP...UPSON...WALTON...WEBSTER. && $$ SHORT TERM...31 LONG TERM....39 AVIATION...31
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
421 AM EST FRI FEB 21 2014 .SYNOPSIS... HIGH PRESSURE WILL RETREAT EASTWARD TONIGHT IN ADVANCE OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL SWEEP THROUGH THE AREA ON FRIDAY...STALLING JUST OFFSHORE UNTIL STRONGER HIGH PRESSURE BUILDS INTO THE AREA ON MONDAY. A LOW PRESSURE SYSTEM COULD DEVELOP OFF THE SOUTHEAST COAST LATE TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... PRE-DAWN...IMPRESSIVE COOL SEASON NOCTURNAL WARM AIR ADVECTION PATTERN IN FULL TILT WITH TEMPS WARMING INTO THE MID TO UPPER 60S OVERNIGHT AS MIXING FROM THE LOW LEVEL JET RESULTING IN AN INCREASING SSW BREEZE MANY LOCATIONS...ESPECIALLY ALONG AND E OF I-95. THIS HAS REDUCED POTENTIAL FOR FOG AND MOST RECENT WEB CAMS ALONG THE BEACHES HAVE BEEN FOG FREE FOR MUCH OF THE OVERNIGHT. THERE STILL IS POTENTIAL FOR SOME DENSE SEA FOG TO BRUSH THE COAST BUT LATEST THINKING IS FOR MORE OF A TRANSIENT/PATCHY SCENARIO AND HAVE ALLOWED LAND-BASED FOG ADVISORIES TO COME DOWN. MOST AREAS WILL REMAIN DRY AT DAWN BUT CONVECTIVE RAINS WILL BE NEARING OUR FAR INLAND ZONES AT THAT TIME. WE CANCELLED A DENSE FOG ADVISORY FOR COASTAL ZONES THIS MORNING GIVEN ONGOING OBSERVATION/SATELLITE TRENDS. A STRONG MID LEVEL SHORT WAVE RIDING BELOW THE LARGE/DEEP CLOSED UPPER LOW OVER THE GREAT LAKES WAS IMPRESSIVE EARLY THIS MORNING ON WATER VAPOR SATELLITE IMAGERY. THIS FEATURE WILL DIG THE MEAN UPPER TROUGH THROUGH THE TENNESSEE/OHIO VALLEYS THIS MORNING THEN LIFT TOWARD NEW ENGLAND LATE TODAY. SUBTLE NEGATIVE TILTING APPEARS TO BE STRONGER OFF TO THE NORTH OF OUR FORECAST AREA THROUGH MID AFTERNOON. ONGOING TRENDS THIS MORNING HAVE INCREASED OUR CONCERNS FOR SEVERE WEATHER POTENTIAL IN THE PRE-FRONTAL ENVIRONMENT THROUGH MID AFTERNOON. THE FIRST...OBVIOUSLY THE MUCH WARMER THAN GUIDANCE READINGS THAT HAVE BECOME ROOTED ACROSS SE GEORGIA AND EASTERN SOUTH CAROLINA EARLY THIS MORNING BEFORE DAYBREAK. ALTHOUGH TIMING OF THE CONVECTIVE LINE THROUGH THE FORECAST AREA REMAINS FAIRLY CONSISTENT FROM PREVIOUS MODEL RUNS TODAY...IT IS NOT GOING TO TAKE MUCH TO ALLOW TEMPS TO RISE WARMER INTO THE LOWER TO MID 70S THIS MORNING. UPSTREAM CONVECTION OVERNIGHT HAS BEEN QUITE ROBUST WITH THE LATEST RAP SHOWING SURFACE BASED INSTABILITY INTO SW GEORGIA WITH SBCAPES OVER 750 J/KG AT 08Z. SOME OF FORECAST AREAS COULD SEE SOME THINNER CLOUDS THROUGH MID MORNING AS DENSE CLOUD COVER WILL BE COMING IN LATER IN THE MORNING. SPC HAS OUR REGION IN A SLIGHT RISK OF SEVERE CONVECTION AND THERE APPEARS TO BE NO REASON TO DOUBT IT PER LATEST MESOSCALE TRENDS. 00Z HIGH RESOLUTION GUIDANCE INDICATING POTENTIAL FOR HIGHER DBZ CORES AND LINEAR ORGANIZATION. GIVEN THE STRONG WIND FIELDS...SMALL BOWS WOULD BE A CONCERN ALONG WITH POSSIBLE FORMATION OF A DECENT REAR INFLOW JET. CONCERN FALLS OVER OUR NW TIER OF ZONES THAT SUFFERED GREAT TIMBER DAMAGE FROM THE RECENT ICE STORM. TSTM GUST IMPACTS COULD CERTAINLY BE MUCH GREATER IN THOSE ZONES WHERE WEAK AND BROKEN LIMBS ALREADY LACE THAT REGION. EVEN A MARGINALLY GUSTY SQUALL LINE COULD MAKE FOR SOME BAD TIMES IN SOME AREAS AND WE WILL REMAIN COGNIZANT OF THIS SITUATION. WE WILL RAMP UP SEVERE WORDING A BIT IN OUR HAZARDOUS WEATHER OUTLOOK THIS MORNING ALTHOUGH IT IS STILL MORE LIKELY THAT WE ONLY SEE ONLY SEE ISOLATED OCCURRENCES OF 50 KT CONVECTIVE WIND GUSTS IN THE CONVECTIVE SEGMENTS/LINES AS TIMING AND STRENGTH OF DYNAMICS DO NOT APPEAR TO COMPLETELY COME IN SYNC FOR A MORE WIDESPREAD EVENT. THE COLD FRONT WILL RACE THROUGH THE FORECAST AREA THIS AFTERNOON AND OFFSHORE BY EARLY EVENING. MUCH COOLER TEMPS EXPECTED TONIGHT WITH LOWS IN THE 40S AND GRADUALLY CLEARING SKIES. && .SHORT TERM /SATURDAY THROUGH MONDAY/... DRY HIGH PRESSURE WILL SETTLE OVER THE REGION ON SATURDAY. AMPLE MOISTURE WITHIN A 105 KT JET OVER THE DEEP SOUTH WILL PRODUCE EXTENSIVE CIRRUS WHICH WILL SLIGHTLY LIMIT INSOLATION. HOWEVER HIGH TEMPS WILL STILL REACH 70F IN MANY SPOTS. ON SUNDAY WE START TO SEE SOME CHANNELED VORTICITY ENERGY MOVE INTO THE EASTERN UNITED STATES. MEANWHILE THE LOW-LEVEL RIDGE OVER THE WESTERN ATLANTIC STARTS TO SHIFT EAST AS THE FLOW BACKS TO SOUTHWESTERLY. AS LOW-LEVEL MOISTURE INCREASES...WEAK ISENTROPIC ASCENT WILL DEVELOP ACROSS SOUTHEAST GA WITH SOME RAIN SHOWERS POSSIBLE BY SUNDAY AFTERNOON. WE ADDED A SLIGHT CHANCE OF TSTMS ACROSS FAR SOUTHERN AREAS BECAUSE A POCKET OF ELEVATED INSTABILITY SHIFTS THROUGH DURING THIS TIME. LOW-LEVEL WARM ADVECTION WILL PUSH HIGH TEMPS INTO THE LOWER TO MIDDLE 70S. A BACKDOOR COLD FRONT WILL DROP INTO THE AREA SUNDAY NIGHT AND PUSH OFFSHORE ON MONDAY. UPPER DYNAMICS ARE NOT VERY IMPRESSIVE ACCOMPANYING THE FROPA SO WE ONLY HAVE 20-40 POPS SUNDAY NIGHT. ON MONDAY...SLIGHTLY COOLER HIGH PRESSURE WILL BUILD IN FROM THE NORTH WHILE THE BACKDOOR FRONT SITS JUST SOUTH OF THE AREA. EXTENSIVE CLOUD COVER WILL ALSO PERSIST THOUGH THE BEST RAIN CHANCES WILL BE FAR SOUTH CLOSER TO THE FRONT. WE SHOW HIGH TEMPS IN THE MID/UPPER 60S. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... THE LONG TERM PATTERN WILL MAINLY BE DOMINATED BY A LOBE OF THE POLAR VORTEX MOVING INTO THE GREAT LAKES REGION LATE WEEK. MONDAY NIGHT THROUGH WEDNESDAY THE UPPER PATTERN WILL BE TRENDING TOWARD A BROAD TROUGH REGIME WITH A SERIES OF WEAK FRONTS AND LOW PRESSURE WAVES AFFECTING THE FORECAST AREA. DUE TO LARGE UNCERTAINTIES IN TIMING INDIVIDUAL FEATURES WE MAINTAINED A CONSERVATIVE FORECAST WITH MAINLY SLIGHT CHANCES FOR SHOWERS AND HIGH TEMPS IN THE 60S. A STRONG COLD FRONT WILL SWEEP THROUGH WEDNESDAY NIGHT... FOLLOWED BY COOL CANADIAN HIGH PRESSURE THURSDAY AND FRIDAY. THIS WILL BRING DRY CONDITIONS AND BELOW-NORMAL TEMPERATURES. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... AT KCHS...LOW CONFIDENCE FORECAST OVERNIGHT AS POTENTIAL FOR LOW CLOUDS IS HIGH BUT TIMING AND AREAL EXTENT/TRANSLATION NEARLY IMPOSSIBLE TO PIN DOWN THANKS TO AN INCREASING LOW LEVEL JET SCENARIO. WE CARRIED ON SIMILAR TRENDS FROM THE 00Z TAF CYCLE WITH MVFR CONDITIONS BECOMING LIKELY CLOSER TO DAYBREAK WITH LESSER CHANCES THE NEXT COUPLE OF HOURS. CONVECTIVE RAINS INCLUDING CHANCES FOR TSTMS EXPECTED TO SWEEP THROUGH THE COASTAL CORRIDOR BETWEEN LATE MORNING AND EARLY AFTERNOON WITH CHANCES FOR A FEW TSTMS WITH GUSTY WINDS. CONDITIONS IMPROVING LATE AFTERNOON WITH VFR CONDITIONS RETURNING. AT KSAV...THE LAST TAF AMENDMENT INDICATES POSSIBLE MVFR CONDITIONS DEVELOPING DUE TO REDUCED CEILINGS FROM SUNRISE TO MID MORNING. MVFR CONDITIONS ARE THEN MAINTAINED IN SHOWERS THROUGH ABOUT 19Z. GUSTY SW SURFACE WINDS ARE EXPECTED TO DEVELOP AFTER MID MORNING AS BETTER MIXING COMMENCES AHEAD OF THE APPROACHING COLD FRONT. SHOWERS AND A FEW TSTMS WILL PASS THROUGH THE MID TO LATE MORNING THROUGH EARLY AFTERNOON IMPROVING CONDITIONS TO VFR LATE AFTERNOON ONWARD. EXTENDED AVIATION OUTLOOK...MVFR CEILINGS POSSIBLE AT KSAV SATURDAY NIGHT AND AT BOTH TERMINALS SUNDAY NIGHT INTO MONDAY MORNING. OTHERWISE VFR. && .MARINE... LITTLE TO NO REPORTS OF DENSE SEA FOG OVERNIGHT ALONG THE COAST WITH SATELLITE IMAGERY ALSO NOT SUPPORTING OF FOG BASED LOW STRATUS OFF THE COAST. THERE STILL IS A CHANCE FOR SEA FOG BUT GIVEN LATEST TRENDS WE OPTED TO CANCEL MARINE FOG ADVISORIES AND JUST FORECAST PATCHY DENSE FOG OVER THE WATERS THROUGH EARLY AFTERNOON WHEN RAIN CHANCES INCREASE AND THE COLD FRONT NEARS. OTHERWISE...NOT MUCH MIXING GOING ON OVER CHILLY SHELF WATERS AND IT IS INTERESTING TO SEE WINDS GUSTS TO 20 KT AT TIMES AT CHARLESTON AND SAVANNAH WHERE TEMPS HAVE WARMED TO THE UPPER 60S. TEMPS AT GRAYS REEF NEAR 60 AND WINDS BELOW 10 KT ALL NIGHT WITH 2-3 FT SEAS...QUITE THE STRONG MARINE INVERSION. SEAS WILL CONTINUE TO BUILD OFFSHORE AND MAINTAINED A MARGINAL SCA FOR CHARLESTON COUNTY WATERS MAINLY WELL EAST OF BULLS BAY. MOST NEAR SHORE WATERS TODAY WILL SEE SW WINDS 15 KT OR SO AND SEAS 3-4 FT TOPS. THERE IS ALSO A SCA FOR OUR OUTER GEORGIA WATERS WITH OCCASIONALLY GUSTY SW FLOW AND SEAS 4-7 FT...HIGHEST NEAR THE WEST WALL OF THE GULF STREAM. THE FRONT MOVES THROUGH THIS EVENING WITH WINDS SHIFTING W OR WNW TONIGHT WITH COLD AIR ADVECTION MORE GRADUAL THAN SHARP...CONDITIONS BELOW SCA CRITERIA. MARINE WINDS/SEAS WILL BE RATHER LIGHT SATURDAY THROUGH SUNDAY BEFORE A COLD FRONT DROPS INTO THE WATER SUNDAY NIGHT. WINDS WILL INCREASE ALONG THE FRONT BUT THE STRONGER SURGE COMES MONDAY AS THE FLOW BECOMES NE. CONDITIONS COULD FLIRT WITH ADVISORY LEVELS... ESPECIALLY MONDAY NIGHT WHEN SEAS COME UP SOME. THE NEXT SURGE COMES WEDNESDAY AND WEDNESDAY NIGHT BEHIND A STRONG COLD FRONT. MODERATE CHANCES FOR SMALL CRAFT ADVISORIES WITH THE MID-WEEK SYSTEM. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ350- 374. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE...JRL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
322 AM EST FRI FEB 21 2014 .SHORT TERM /TODAY THROUGH SATURDAY/... MAIN FORECAST CONCERN THROUGH THE SHORT TERM CONTINUES TO BE THE COLD FRONT PUSHING INTO NORTHWEST GEORGIA THIS MORNING. OVERALL MODELS STILL CONSISTENT WITH THE TIMING OF THE SYSTEM THROUGH THE AREA...AND FORECAST IS SKEWED TOWARDS HRRR AND LOCAL WRF FOR TIMING OF THE FRONT PUSHING OUT OF THE CWA. ANTICIPATE THE BULK OF THE ACTIVITY TO BE THROUGH THE ATL AREA 08-11Z...AND THROUGH THE MCN AREA BY 11-13Z. SEVERE POTENTIAL ENOUGH TO ISSUE SVR TSTM WATCH THROUGH SUNRISE. NAM CONTINUES TO ADVERTISE THE HIGHER MUCAPE VALUES...WITH THE GFS STILL AROUND 300-400J/KG AND MODELED LOW LEVEL SHEAR STILL IN THE 45-50KT RANGE. OVERALL THE TORNADO THREAT IS MARGINAL AND IS EXPECTED GRADUALLY LESSON THROUGH THE EARLY MORNING HOURS. THAT BEING SAID...AN ISOLATED TORNADO CAN NOT BE RULED OUT ENTIRELY. A TORNADO WATCH CONTINUES THROUGH 10Z FOR NORTHERN PORTIONS OF THE CWA. THE MAIN CONCERN CONTINUES TO BE THE DAMAGING WINDS ASSOCIATED WITH THE LINE GIVEN THE SUFFICIENT WIND SHEAR AND INSTABILITY. SOME ROTATION HAS BEEN NOTED /ALBEIT BROAD/ IN THESE STORMS AS THEY HAVE MOVED INTO THE STATE. AS THE STORMS MOVE THROUGH...THE THREAT OF SEVERE ACTIVITY DROPS OFF QUICKLY. LIGHT RAIN SHOWERS WILL PERSIST BEHIND THE MAIN LINE FOR A FEW HOURS BEFORE CLEARING BEGINS. WINDS ASSOCIATED WITH THE LINE WILL ALSO DIMINISH INTO THE DAYLIGHT HOURS. GUSTY WINDS AHEAD OF THE FRONT AND THE DAMAGING WINDS EMBEDDED WITHIN THE CONVECTION COULD BRING DOWN ALREADY WEAKENED TREES ESPECIALLY VULNERABLE FROM THE RECENT ICE STORM. QPF OF 1-1.25 INCHES WITH LOCALLY HIGHER AMOUNTS ACROSS NORTHWEST GEORGIA COULD RESULT IN QUICKLY RISING CREEKS AND RIVERS. BEHIND THE FRONT...HIGH PRESSURE BUILDING INTO THE REGION WILL KEEP THE REMAINDER OF THE SHORT TERM DRY. LOOKING FOR HIGHS IN THE 60S FRIDAY AND SATURDAY...WITH LOWS IN THE 30S SATURDAY MORNING. 31 .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE OVERALL ACTIVE PATTERN CONTINUES INTO THE EXTENDED PERIOD. MODELS CONTINUE TO SHOW NEARLY ZONAL FLOW ACROSS THE AREA INTO THE LONG TERM. A WEAK UPPER LEVEL DISTURBANCE WITHIN THIS ZONAL FLOW INTERACTS WITH AN OLD FRONTAL BOUNDARY ACROSS THE SOUTHERN PORTION OF THE STATE. AS A RESULT...HAVE CONTINUED WITH THE SLIGHT CHANCE TO CHANCE POPS SUNDAY...WITH THE BEST CHANCES FARTHER SOUTH. A REINFORCING COLD FRONT PUSHES ACROSS THE AREA SUNDAY NIGHT INTO MONDAY...WITH A DRY AND COOLER AIR MASS RETURNING TO THE STATE MONDAY. BY MID WEEK...WEAK FRONTAL BOUNDARY MEANDERING ACROSS THE STATE INTERACTS WITH THE FLOW ALOFT...BUT MODEL UNCERTAINTY STILL HIGH ENOUGH TO JUST CONTINUE WITH SLIGHT CHANCES OF SHOWERS. WITH LIMITED INSTABILITY AND WIND SHEAR...HAVE CONTINUED TO LEAVE OUT MENTION OF THUNDERSTORMS AT THIS TIME. 39 && AVIATION... 06Z UPDATE... LINE OF SHOWERS AND THUNDERSTORMS EXPECTED TO MOVE THROUGH THE AREA OVERNIGHT...WITH DEGRADING CIGS AND VSBYS ACCOMPANYING THE TSRA. HAVE TIMED THE SQUALL LINE THROUGH THE ATL AREA BY 10Z...AND THE MCN AND AHN AREAS BY AROUND 12Z. S-SW GUSTY WINDS /15G25KT OR SO/ WILL BECOME NW AT 13-15KT GUSTS TO 22-25KT BEHIND THE LINE. EXPECT HIGH IFR OR LOW MVFR CIGS WITH THE POST-TSRA LIGHT RAIN...WITH SLOW IMPROVEMENT THROUGH FRIDAY MORNING...AND VFR BY AFTERNOON. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE ON ALL ELEMENTS. 31 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 63 36 68 40 / 100 5 5 10 ATLANTA 61 39 66 43 / 80 5 5 10 BLAIRSVILLE 57 32 63 36 / 70 5 5 10 CARTERSVILLE 61 32 66 38 / 60 5 5 10 COLUMBUS 63 39 67 41 / 100 5 5 20 GAINESVILLE 62 38 65 40 / 100 5 5 10 MACON 64 34 68 40 / 100 5 5 10 ROME 60 31 65 36 / 40 5 5 10 PEACHTREE CITY 61 30 66 36 / 90 5 5 10 VIDALIA 68 45 70 46 / 100 10 5 10 && .FFC WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 9 AM EST THIS MORNING FOR THE FOLLOWING ZONES: CARROLL...CHATTAHOOCHEE...CLAYTON...COBB... COWETA...DEKALB...DOUGLAS...FAYETTE...GWINNETT...HARALSON... HARRIS...HEARD...HENRY...MARION...MERIWETHER...MUSCOGEE...NORTH FULTON...PAULDING...PIKE...POLK...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...TAYLOR...TROUP... UPSON...WEBSTER. TORNADO WATCH UNTIL 5 AM EST EARLY THIS MORNING FOR THE FOLLOWING ZONES: BARTOW...CATOOSA...CHATTOOGA...CHEROKEE... DADE...DAWSON...FANNIN...FLOYD...FORSYTH...GILMER...GORDON... HALL...LUMPKIN...MURRAY...PICKENS...TOWNS...UNION...WALKER... WHITE...WHITFIELD. && $$ SHORT TERM...31 LONG TERM....39 AVIATION...31
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
849 PM CST SAT FEB 22 2014 .DISCUSSION... 300 PM...FORECAST CONCERNS INCLUDE A FEW INCHES OF SNOW ACROSS THE FAR SOUTHEAST CWA THIS EVENING...A FEW INCHES OF SNOW ACROSS THE ENTIRE AREA MONDAY NIGHT...AND THE RETURN OF ARCTIC AIR NEXT WEEK. BAND OF PRECIP HAS DEVELOPED OVER THE FAR SOUTHEAST CWA THIS AFTERNOON AND THIS HAS BEEN SHOWN FAIRLY WELL AND CONSISTENTLY ON THE SHORT TERM/HI RES GUIDANCE. THE CONTINUED TREND IS TO HAVE THIS BAND PUSH SOUTHEAST OF THE CWA DURING THE MID EVENING HOURS. ONLY CHANGE FROM THE UPDATE EARLIER TODAY IS TO TIGHTEN THE POP GRADIENT A BIT WITH THE A SLIGHT CHANCE OF SNOW ABOUT TO THE KANKAKEE RIVER...DRY NORTH OF THERE. TIMING-WISE...ITS POSSIBLE THAT THIS BAND COULD DRIFT SOUTHEAST OF THE CWA SOONER RATHER THAN LATER AND SHOULD THAT HAPPEN...AMOUNTS COULD BE A BIT LOWER WITH 1 TO 3 INCHES CURRENTLY EXPECTED GENERALLY SOUTH OF A PIPER CITY TO A RENSSELAER LINE. A RIDGE OF HIGH PRESSURE WILL BUILD FROM THE NORTHERN PLAINS TONIGHT TO THE SOUTHERN LAKES AND OHIO VALLEY SUNDAY INTO SUNDAY NIGHT. THIS WILL MARK THE BEGINNING OF A DOWNWARD TREND IN TEMPS AS HIGHS ON SUNDAY ONLY REACH THE MID/UPPER 20S WITH HIGHS A FEW DEGREES LOWER AGAIN ON MONDAY. HOWEVER...DRY CONDITIONS ARE EXPECTED THROUGH MONDAY AFTERNOON. THE NEXT CHANCE OF SNOW HAS BEEN DELAYED SLIGHTLY TO MONDAY NIGHT AND HAVE GENERALLY FOLLOWED THE ECMWF WHICH HAS BEEN THE MOST CONSISTENT AND SHOWS A SWATH OF QPF OF A TENTH OF AN INCH OR SO. GIVEN THE COLD TEMPS DURING THIS TIME PERIOD...THE SNOW WILL BE QUITE DRY/FLUFFY AND A FEW INCHES OF ACCUMULATION STILL APPEAR ON TRACK AND HAVE INCREASED POPS BACK TO LIKELY FOR THIS TIME PERIOD. WITH THE SLOWER ARRIVAL...LIGHT SNOW MAY PERSIST INTO TUESDAY MORNING AND HAVE INTRODUCED LOW CHANCE POPS. FIRST PUNCH OF COLD AIR THEN ARRIVES TUESDAY/TUESDAY NIGHT AS LOWS DROP INTO THE LOW SINGLE DIGITS...LIKELY BELOW ZERO ACROSS THE NORTHWEST CWA. LOW PRESSURE THEN PASSES ACROSS THE NORTHERN LAKES WEDNESDAY AFTERNOON/EVENING WITH A COLD FRONT PUSHING ACROSS THE REGION WEDNESDAY EVENING. THIS WILL BRING THE SECOND PUNCH OF COLDER AIR WITH 850MB TEMPS STILL PROGGED INTO THE -22C TO -26C RANGE. CONTINUED LOW SINGLE DIGITS TO BELOW ZERO TEMPS ARE EXPECTED BOTH THURSDAY MORNING AND AGAIN FRIDAY MORNING. HIGHS DURING THIS TIME ARE SOMEWHAT MORE UNCERTAIN DUE TO STRONGER LATE FEBRUARY SUNSHINE...BUT WILL BE 15-25 DEGREES BELOW NORMAL. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * NONE. RC //DISCUSSION...UPDATED 00Z... NO SIGNIFICANT AVIATION CONCERNS AT THE TAF SITES FOR THE NEXT 24-30 HOURS...WITH VFR CONDITIONS AND GENERALLY WESTERLY WINDS. GUSTS COULD APPROACH 20 KT SUNDAY AFTERNOON INTO SUNDAY EVENING. RC //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH FOR ALL ELEMENTS. RC //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...VFR LIKELY DURING DAYTIME THEN LIGHT SNOW BECOMING LIKELY MONDAY NIGHT WITH MVFR LIKELY...IFR POSSIBLE. TUESDAY...CHANCE OF LIGHT SNOW EARLY AM. THEN VFR LIKELY. WEDNESDAY THROUGH FRIDAY...VFR LIKELY. RC && .MARINE... 148 PM CST LOW PRESSURE CENTERED NEAR JAMES BAY THIS AFTERNOON CONTINUES TO PRODUCE WINDS OF 25 TO 30 KT ACROSS THE LAKE THIS AFTERNOON. THIS LOW WILL GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE WEEKEND. HOWEVER...WESTERLY WINDS WILL CONTINUE IN THE 20 TO 30 KT RANGE SUNDAY INTO MONDAY AS THE SURFACE GRADIENT REMAINS ELEVATED IN ADVANCE OF A BROAD RIDGE OF SURFACE HIGH PRESSURE EXTENDING FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. THE NEXT POTENTIAL HEADLINE WORTHY WIND EVENT WILL BE AROUND THE MIDDLE OF NEXT WEEK. A FEW CLIPPER TYPE SYSTEMS ARE EXPECTED TO DROP SOUTHEASTWARD ACROSS THE LAKES REGION DURING THIS PERIOD. OF THESE NUMEROUS CLIPPER SYSTEMS...IT APPEARS THAT A POTENT ONE WILL DROP ACROSS THE REGION WEDNESDAY NIGHT. THIS SYSTEM COULD PRODUCE A PERIOD OF SOUTHWESTERLY GALES ON WEDNESDAY...FOLLOWED BY A PERIOD OF POTENTIALLY HIGH END NORTHWESTERLY GALES IN ITS WAKE WEDNESDAY NIGHT INTO THURSDAY. WITH ANOTHER DEEP ARCTIC SURGE OF COLD AIR EXPECTED IN THE WAKE OF THIS SECOND CLIPPER...THERE WILL ALSO LIKELY BE SIGNIFICANT FREEZING SPRAY IN CONJUNCTION WITH THE STRONG NORTHWESTERLY GALES WEDNESDAY NIGHT INTO THURSDAY. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion National Weather Service Lincoln IL 636 PM CST Sat Feb 22 2014 .DISCUSSION... ISSUED 636 PM CST Sat Feb 22 2014 Made a few quick updates to the forecast to better reflect current trends, mainly to tighten the POP gradient across central Illinois. Radar continues to indicate the narrow band of precipitation remaining focused along a Jacksonville to Danville line. Latest run of the HRRR shows very little movement of the band until 04z when it slowly sinks southeastward. As a result, have increased POPs to categorical within the band itself and have removed all mention of POPs further north in the Peoria area and further south from Effingham southward. With surface temps in the middle to upper 30s initially, precip has started as rain at most sites, but is quickly transitioning to wet snow as evaporative cooling takes place within the surface-based layer. Based on gradual eastward shift of precip area and current temps above freezing, think snow accumulations will remain light. 1 to 2 inches still look reasonable across the E/NE KILX CWA, mainly from Decatur northeastward through Champaign to Danville, with little or no accumulation elsewhere around the area. Zone update has already been issued. Barnes && .AVIATION... ISSUED 551 PM CST Sat Feb 22 2014 Narrow band of precipitation has developed just north of a nearly stationary frontal boundary late this afternoon. High-res models such as the HRRR suggest that this band will remain focused along a KSPI to KDEC to KCMI line for the next 3 to 4 hours before gradually diminishing/shifting eastward into Indiana. Radar trends seem to be following this forecast quite nicely thus far. As a result, have kept both KPIA and KBMI dry. Further south at the remaining terminals, light precip will start as rain then slowly mix with and change to snow before ending. Lowest ceilings/visbys associated with snow will likely be noted across the E/NE CWA, so have gone with IFR conditions at KCMI. After 05z, precip will push into Indiana, leaving behind mostly cloudy and dry conditions through the remainder of the 00z TAF period. Barnes && .PREV DISCUSSION... ISSUED 300 PM CST Sat Feb 22 2014 Light snow or flurries will return this afternoon and this evening across most of the area. Measurable snow will be mainly confined to areas east of I-55, with an inch or two possible closer to Indiana east of Champaign to Mattoon. The next chance of snow beyond that appears to be late Monday and Monday night north of Lincoln to Champaign as the next shortwave moves across N IL. Dry conditions are expected the remainder of the forecast, with a dry cold frontal passage Wed night ushering in reinforcing cold air. Below normal temperatures will prevail for much of this 7-day forecast. SHORT TERM...Tonight through Monday. A band of mid-level frontogenesis north of the stationary front along I-70 will create some lift that will be enhanced by steep mid-level lapse rates. That should give the virga a boost in saturating the lower levels. Flurries already started at PIA around 2 pm after several hours of virga. Satellite pics show a baroclinic leaf developing ahead of the weak low pressure over western Missouri. That low is projected to slide east along the boundary, which should further enhance the thermo-dynamic forcing. Meso-scale bands of precip are being advertised by the HRRR and NMM-east. Light snow will be north of Mattoon to Paris with some rain or rain-snow mix south of there. We could see an inch or two of snow where the band of snow rotates and lingers across our east-central counties...bounded by a line from Decatur to Hoopeston in the north and Taylorville to Mattoon to Paris in the south. Even in this late hour, many differences exist with the placement and intensity of any meso-scale bands of precip late this afternoon and evening. The GFS and Canadian GEM are more aggressive with snow, while the NAM is the weakest and the ECMWF is in the middle. We increased PoPs to categorical and likely in areas with an inch or more snow possible, with high chance bordering that. Accums are a tough call with this much dry air to overcome, but forcing looks strong enough for a short duration to get some light accumulation. Precip should progress eastward after midnight, and come to an end for our counties by 3 am. Colder air will begin to advance into C IL with the surface high, which should help lows across the north drop into the teens. Clouds will temper the cool-down, as southern areas remain in the low 30s. The 12z Canadian has increased potential for snow or rn/sn as a shortwave advances east, just north of the stationary front. The ECMWF is also showing some forcing across our southern counties, but lower RH and no precip. After coord with offices to the south, we decided to just add sprinkles and flurries for now on Sunday. Mostly clear skies for much of Sunday night will provide better radiational cooling conditions, and lows will respond by dropping into the single digits north of Peoria. Monday afternoon and evening will see a 125kt jet at 250mb help push a shortwave across northern IL. Light snow will develop mainly north of a line from Rushville to Champaign...with a dusting along the line to as much as an inch from Galesburg to El Paso. The NAM is the main outlier with this period of snow, with much less forcing and farther south than the GFS/ECMWF/Canadian. We went with consensus and increased PoPs to likely across Knox to Woodford counties Monday eve. LONG TERM...Tuesday through Saturday. We are not expected any measurable precip through the extended forecast as colder air prevails. A dry cold frontal passage on Wed night will aid in keeping temps well below normal. Lows will dip below zero across our northern area on Tuesday night, and get very close to zero in the north Wed night and Thurs night. Highs will struggle to climb out of the teens north of I-72 on Wed. Gradual warming will develop from Thurs to Saturday, but even Saturday`s highs will range from mid 20s north to mid 30s south, or about 10 to 15 deg below normal. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
535 AM CST FRI FEB 21 2014 .DISCUSSION... 305 AM CST TODAY... POWERFUL STORM SYSTEM CONTINUES TO INFLUENCE THE WEATHER FOR THE REGION TODAY...DESPITE THE SFC LOW BECOMING CENTERED WELL NORTH OF THE FORECAST AREA THIS MORNING OVER NORTHERN WISCONSIN. A VERY TIGHT GRADIENT REMAINS OVER NORTHERN IL/NORTHWEST IN...AS EARLY THIS MORNING ISALLOBARIC PRES RISES HOVER ARND 5MB/3HR. THIS HAS BEEN PRODUCING SUSTAINED WINDS BETWEEN 20-30MPH AND GUSTS AT TIMES TO 45 MPH. WILL MAINTAIN THE CURRENT WIND ADVISORY...HOWEVER BASED ON LATEST GUIDANCE IT APPEARS GUSTS MAY BEGIN TO DIMINISH CLOSER TO MIDDAY. IR IMAGERY INDICATES THE DRY WEDGE HAS DEPARTED TO THE NORTHEAST...WITH THE WRAP-AROUND MOISTURE BEGINNING TO SLIDE BACK INTO NORTHERN IL/NORTHWEST IN. SFC OBS UPSTREAM EARLY THIS MORNING HAVE INDICATED SOME LIGHT SNOW...AND A FEW POINTS IN CENTRAL IOWA HAD VSBYS DOWN TO 1/4 MILE WITH MODERATE SNOW...HOWEVER FEEL THIS MAY HAVE ACTUALLY BEEN A FUNCTION OF THE VERY GUSTY WINDS AND AMPLIFYING THE EFFECTS SLIGHTLY. OVERALL THOUGH EXPECT THIS WRAP-AROUND WEDGE TO SLOWLY SLIDE NORTHEAST...CLIPPING NORTHERN IL THIS MORNING. THIS MAY PRODUCE A DUSTING OF SNOW...OTHERWISE BY LATE MORNING FLURRIES SHOULD BE ALL THAT REMAINS BEFORE ENDING EARLY THIS MORNING. TEMPS TODAY WILL BE CHAOTIC...WITH MORNING TEMPS MAINLY IN THE 30S ACROSS THE REGION THEN FALLING INTO THE 20S. WITH CLOUD COVER ERODING BY EARLY AFTN FROM SOUTHWEST TO NORTHEAST...THIS MAY ALLOW TEMPS TO REBOUND A FEW DEGREES THIS AFTN. SO AS A RESULT HAVE HELD ONTO HIGHS IN THE LOW/MID 30S WITH NEAR 40 ALONG THE FAR SOUTHERN CWFA. CONFIDENCE...HIGH. TONIGHT THROUGH SUNDAY... 500MB TROUGH AXIS RETURNS TO THE REGION...WHICH PLACES A HOLD ON THE PAST FEW DAYS OF ABNORMALLY WARM TEMPS AND BRINGS A REALITY CHECK THAT WINTER IS STILL THE PREFERRED SEASON OF CHOICE BY MOTHER NATURE. WITH THE POWERFUL SHORTWAVE STEADILY LIFTING NORTHEAST TOWARDS JAMES BAY TONIGHT...THE TRAILING GRADIENT WILL WEAKEN. BROAD SFC RIDGING IS POISED TO SLIDE EAST ACROSS THE TENN VALLEY STRETCHING SOUTH TO THE GULF OF MEXICO. THIS WILL ALLOW THE FLOW OVER OUR REGION TO MAINLY BE WESTERLY THROUGH TONIGHT AND INTO SATURDAY. GUIDANCE DIFFERS ON HOW TO RESOLVE A WEAK MID-LVL LOBE OF VORTICITY THAT WILL MOVE EAST ACROSS THE CENTRAL PLAINS TOWARDS THE OHIO VALLEY. THE FORCING LOOKS RATHER LOW WITH THIS FEATURE...HOWEVER A SECONDARY SFC RIDGE OVER THE NORTHERN PLAINS WILL STRETCH SOUTHEAST TOWARDS THE FORECAST AREA SAT NGT. AT THIS TIME HAVE HELD ONTO A DRY FORECAST...HOWEVER COULD SEE FLURRIES BEING NEEDED AND PERHAPS A SMALL WINDOW OF LIGHT SNOW SHOWERS INTO EARLY SUN MORNING. THE 500MB TROUGH DOES NOT INDICATE ANY AMPLIFICATION THROUGH THE WEEKEND...WHICH WILL LIKELY MAINTAIN A SEMI-ZONAL FLOW. THIS WILL EXPEDITE PACIFIC WAVES REACHING THE FORECAST AREA/OHIO VALLEY IN AN EFFICIENT MANNER. AS A RESULT GUIDANCE CONTINUES TO SUGGEST YET ANOTHER WEAK MID-LVL LOBE OF VORTICITY ARRIVING SUN AFTN. TEMPS TONIGHT WILL FALL INTO THE TEENS TO MID 20S...THEN WITH P-CLOUDY SKIES SAT AND 850MB TEMPS HOVERING ARND -4 TO -6 DEG C...HIGHS SAT SHOULD GENERALLY BE IN THE LOW 30S...POSSIBLY NEAR 40 FOR THE FAR SOUTHERN CWFA. WEAK FRONTAL BOUNDARY SLIDES OVER THE AREA SUN...WITH WINDS TURNING NORTHWESTERLY AND BRINGING SLIGHTLY COOLER AIR AS HIGHS ARE GENERALLY IN THE 20S. CONFIDENCE IN TEMPS...MEDIUM/HIGH. CONFIDENCE IN FLURRIES/LGT SNOW...MEDIUM. MONDAY THROUGH FRIDAY... ENSEMBLES HAVE CONTINUED TO POINT TOWARDS YET ANOTHER PATTERN CHANGE BREWING IN THE EXTENDED PERIODS...WITH A HIGH-AMPLITUDE RIDGE DEVELOPING OVER WESTERN CANADA OR THE YUKON. THE DOWNSTREAM RESULT IS YET ANOTHER DEEP TROUGH DIGGING SOUTH THROUGH THE GREAT LAKES REGION. A WEAK MID-LVL WAVE WILL TRAVERSE THE REGION MON...WITH A PERIOD OF LIGHT SNOW PROGGED TO BLANKET THE CWFA. THEN MOVING INTO TUE/WED...A STRONGER FRONTAL BOUNDARY IS POISED TO SLIDE SOUTHEAST FROM CANADA AND BRING 850MB THERMAL TROUGH OF -14 TO -20 DEG C TO THE REGION BY WED...HOWEVER THIS MAY BE MILD COMPARED TO THE LATER PERIODS WHEN GUIDANCE IS CURRENTLY SUGGESTING 850MB TEMPS BY LATE NEXT WEEK IN THE -23 TO -28 DEG C RANGE. THIS WILL LIKELY ALLOW SFC TEMPS FOR THE MIDDLE OF NEXT WEEK TO REMAIN IN THE TEENS...THEN POSSIBLY STRUGGLE TO WARM BEYOND THE SINGLE DIGITS ABOVE ZERO BY THUR OF NEXT WEEK. CONFIDENCE...HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * VERY GUSTY WESTERLY WINDS. * MVFR CIGS IMPROVING TO VFR LATE MORNING/EARLY AFTERNOON. * LIGHT SNOW EARLY TO MID MORNING...WITH BLOWING SNOW. BMD //DISCUSSION...UPDATED 12Z... A DEEP AREA OF LOW PRESSURE CURRENTLY OVER FAR NORTHERN WISCONSIN CONTINUES TO LIFT AWAY FROM THE AREA...BUT STRONG WESTERLY WINDS ARE FORECAST TO PERSIST MUCH OF THE DAY WITH GUSTS IN THE MID TO UPPER 30 KT RANGE THROUGH THE AFTERNOON...TAPERING INTO THE HIGH 20 TO LOW 30 KT RANGE THIS EVENING. MEANWHILE...AN UPPER LEVEL DISTURBANCE IS DROPPING SOUTHEAST ACROSS THE MID/UPPER MISSISSIPPI VALLEY EARLY THIS MORNING WITH SNOW SPREADING ACROSS NORTHERN ILLINOIS. VSBY IS FALLING INTO THE 1-2SM RANGE AT TIMES WITH THE SNOW AND BLOWING SNOW. THE WAVE SHOULD PASS WITH PRECIP ENDING MID TO LATE THIS MORNING...AND WE MAY SEE LIGHT ACCUMULATIONS OF A FEW TENTHS. MVFR CIGS WILL PERSIST THIS MORNING...BUT DRIER AIR MOVING IN SHOULD SCOUR OUT SOME OF THE LOWER CLOUDS BY EARLY AFTERNOON WITH CONDITIONS BECOMING VFR. WINDS WILL EASE THIS EVENING AND TONIGHT...AND SHOULD REMAIN SW TO W. BMD //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM-HIGH CONFIDENCE IN SPEED. * MEDIUM-HIGH CONFIDENCE IN CIG TRENDS...MEDIUM IN TIMING IMPROVEMENT TO VFR. * LOW CONFIDENCE IN HOW AREAS OF SNOW WILL EVOLVE OVERNIGHT. BMD //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT THROUGH SUNDAY...VFR. MONDAY...CHC SNOW...ESPECIALLY LATE. TUESDAY THROUGH THURSDAY...VFR. BMD && .MARINE... 302 AM CST STRONG LOW PRESSURE LIES OVER WISCONSIN EARLY THIS MORNING AND WILL LIFT NORTH ACROSS ONTARIO TO JAMES BAY BY LATE TONIGHT. MEANWHILE...A TIGHT PRESSURE GRADIENT WILL RESULT IN STRONG GALES AND STORM FORCE WINDS AT TIMES ACROSS LAKE MICHIGAN THROUGH THIS AFTERNOON. WILL LEAVE THE CURRENT TIMING IN PLACE FOR THE STORM WARNING...THOUGH LATEST PROJECTIONS INDICATE THAT IT MAY BE CANCELED EARLY. EITHER WAY...A GALE WARNING WILL BE NEEDED TO REPLACE THE STORM WARNING FOR A PERIOD LATE THIS AFTERNOON INTO THE EARLY OVERNIGHT HOURS. WINDS SHOULD FINALLY DIMINISH BELOW GALES LATE TONIGHT BUT WILL REMAIN AROUND 30 KT THROUGH THE REMAINDER OF THE WEEKEND. A BROAD RIDGE OF HIGH PRESSURE WILL BUILD FROM THE NORTHERN PLAINS INTO THE OHIO VALLEY AND REMAIN ANCHORED FOR MUCH OF THE UPCOMING WEEK...LEAVING LAKE MICHIGAN WITH PERSISTENT MODERATE WEST TO NORTHWEST WINDS NEXT WEEK. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023- ILZ032-ILZ033-ILZ039 UNTIL 3 PM FRIDAY. IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 3 PM FRIDAY. LM...STORM WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM FRIDAY. GALE WARNING...NEARSHORE WATERS UNTIL 6 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 350 AM CST Fri Feb 21 2014 .DISCUSSION... ISSUED 323 AM CST Fri Feb 21 2014 Dynamic storm system moved through the region yesterday and overnight with the main cold front well out to the east and the occluded low center over nrn Wisconsin this morning. A small wave rippling around this morning in the wake of the cold front bringing some light snow and may continue through the morning hours. Other than that, forecast is mainly a slow chill beyond today and tomorrow as another push of cold air comes to the Midwest. As far as precipitation, several shortwaves are hinted in the models, but timing is not very consistent. Best consistency is for Monday/Monday night, with the chance for accumulating snow. Beyond Monday, temperatures fall below normals in the extended for next week. At this point the forecast in the extended is dry, but as it is also increasingly NWrly flow, expect to eventually see a couple of short waves creep into the forecast. SHORT TERM...Today and tomorrow... A short break in the frigid temperatures as the max temps will climb above freezing heading into the weekend. Clearing this morning should result in a sunny afternoon, but clouds redevelop for tomorrow so partly cloudy skies will keep temps from increasing too much over todays max. Tonight and tomorrow night, a quick shot for snow across the northern tier of the CWA as shortwaves ripple through in the wake of the exiting low. Both shots at precip should result in less than a half of an inch of accumulation. LONG TERM...Sunday through Thursday... Relatively dry but beyond the weekend the operational models are shearing out some energy across the center of the country and setting up a weak boundary in parallel flow. Agreement btwn GFS and ECMWF for the existence of a Monday/Monday night system, with major issues with the timing. At the end of the NAM run, but the NAM is leaning into the same solution. Just another quick shot of snow with a clipper-like system from the WNW. Colder air moving in as well, as flow amplifies and Midwest sees northwesterly flow reestablish Tuesday night/Wednesday. Temperatures from midweek on drop below seasonal normals again. HJS && .AVIATION... ISSUED 1139 PM CST Thu Feb 20 2014 Strong W/SW winds will continue through the overnight hours, although they will not be quite as strong as earlier this evening. Based on latest obs and 00z numeric guidance, have lowered winds into the 15 to 20kt range with gusts to between 25 and 30kt. The strong/gusty winds will continue through Friday as well, before subsiding to around 10kt by evening. Main aviation challenge will be an area of MVFR clouds currently pushing eastward across Iowa/northern Missouri. Satellite timing tools bring these clouds into KSPI by 08z, then further east to KCMI between 09z and 10z. HRRR does not have a good handle on the clouds, but at least hints at ceilings overnight into early Friday morning. Have therefore cleared skies from west to east between 12z and 14z. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 AM CST FRI FEB 21 2014 .DISCUSSION... 311 PM CST THIS EVENING WILL SEE A QUICK TRANSITION FROM DENSE FOG TO BRIEFLY HEAVY RAIN WITH THUNDERSTORMS...TO RAPIDLY FALLING TEMPERATURES AND VERY STRONG WIND GUSTS. NOT SURE ABOUT EXACT TIMING OF BETTER VISIBILITIES THIS EVENING...SO WILL MAINTAIN THE DENSE FOG ADVISORY THROUGH 01Z BUT EXPECT SOUTHERN AREAS MAY CLEAR EARLIER THAN THAT. VERY DENSE FOG WITH VISIBILITIES OF 1/4 MILE OR LESS IS BEING REPORTED AT SEVERAL OBSERVATION SITES...AND LOWER VALUES ARE LIKELY OUT THERE SOMEWHERE. LATER THIS EVENING MODEL GUIDANCE AND UPSTREAM OBSERVATIONS BOTH CONTINUE TO SUPPORT THE POTENTIAL FOR NON CONVECTIVE GUSTS IN EXCESS OF 50 MPH FOR AT LEAST A WHILE AS THE COLD FRONT PUSHES THROUGH. LASTLY...THE FLOOD WATCH WAS ALLOWED TO EXPIRE AT 3 PM CST AFTER THE BREAK IN THE AFTERNOON SHOWERS. SNOWMELT DOES CONTINUE AND UPSTREAM STORMS MAY YET PRODUCE HEAVY RAIN...BUT THE STORMS SHOULD BE VERY LOCALIZED AND RELATIVELY BRIEF. TEMPERATURES FALLING BELOW FREEZING LATER THIS EVENING WOULD HELP TO FURTHER MITIGATE THE DEGREE OF SNOWMELT. LENNING OVERNIGHT THROUGH THURSDAY... AS COLDER AIR SPREADS ACROSS THE REGION BEHIND THE COLD FRONT...A PERIOD OF LIGHT SNOW WILL BE POSSIBLE ESPECIALLY ACROSS THE NORTHERN THIRD/HALF OF THE CWA. WITH ONLY A FEW HUNDREDTHS OF QPF...SNOWFALL AMOUNTS WILL BE LIGHT A DUSTING TO PERHAPS A HALF INCH. BUT WITH THE STRONG/GUSTY WINDS...ANY AMOUNT OF SNOWFALL COULD CAUSE BLOWING AND DRIFTING SNOW. HAVE INCREASED POPS TO LIKELY ACROSS THE NORTH OVERNIGHT BUT THESE MAY NEED TO GO HIGHER AND PERHAPS BE EXTENDED INTO FRIDAY MORNING...ESPECIALLY FOR FAR NORTHEAST IL. TEMPS WILL FALL THROUGH THE 20S AND COMBINED WITH THE STRONG WINDS...WIND CHILLS IN THE SINGLE DIGITS ARE EXPECTED BY FRIDAY MORNING. A BRIEF PERIOD OF WEAK WARM AIR ADVECTION WILL OCCUR FRIDAY AFTERNOON INTO FRIDAY EVENING AND THIS COMBINED WITH AT LEAST PARTLY CLOUDY SKIES SHOULD HELP TEMPERATURES REBOUND INTO THE LOWER/MID 30S NORTH TO UPPER 30S/NEAR 40 SOUTH. A COLD FRONT WILL THEN MOVE ACROSS THE AREA FRIDAY NIGHT AND THERE REMAINS SOME POTENTIAL FOR LIGHT SNOW OR SNOW SHOWERS AND HAVE INTRODUCED LOW CHANCE POPS BACK INTO THE FORECAST FOR THIS TIME PERIOD. FLOW REMAINS SOMEWHAT ZONAL SATURDAY WITH NO SIGNIFICANT COOLING BEHIND THE FRONT...SO HIGHS SATURDAY COULD BE SIMILAR TO HIGHS ON FRIDAY. BY SUNDAY MORNING...ANOTHER WEAK WAVE WILL QUICKLY MOVE ACROSS THE REGION WITH A PERIOD OF LIGHT SNOW ASSOCIATED WITH IT. WHERE IT MOVES/DEVELOPS REMAINS SOMEWHAT UNCERTAIN BUT THE NORTHERN EXTENT OF IT MAY SPREAD ACROSS THE SOUTHERN CWA AND HAVE INCLUDED LOW CHANCE POPS FOR THIS PERIOD. FROM SUNDAY THROUGH THURSDAY...THE TREND WILL BE COLDER WITH HIGHS ONLY IN THE 20S AND LOWS IN THE SINGLE DIGITS...AND THAT IS BEFORE THE NEXT PUSH OF ARCTIC AIR ARRIVES WEDNESDAY/WEDNESDAY NIGHT. BY THIS TIME...OVERNIGHT LOWS WILL LIKELY DROP INTO SINGLE DIGITS BELOW ZERO WITH DAYTIME HIGHS BY THURSDAY MAYBE ONLY LOWER TEENS/SINGLE DIGITS. ONE OTHER CONCERN IN THE EXTENDED WOULD BE A CLIPPER SYSTEM TO AFFECT THE REGION MONDAY AFTERNOON INTO MONDAY NIGHT. THIS HAS BEEN A FAIRLY CONSISTENT FEATURE ON THE GFS/ECMWF FOR SEVERAL RUNS AND SEEMS TO MOVE RIGHT ACROSS THE CWA BUT NOW IN A WEAKENING FORM. THIS STILL APPEARS TO HAVE THE POTENTIAL TO PRODUCE A FEW INCHES OF FLUFFY SNOW BUT HAVE ONLY BUMPED POPS INTO MID CHANCE RANGE FOR NOW. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * VERY GUSTY WESTERLY WINDS. * MVFR CIGS IMPROVING TO VFR LATE FRIDAY MORNING/EARLY AFTERNOON. * CHANCE FOR SOME ADDITIONAL LIGHT SNOW SHOWERS EARLY TO MID FRIDAY MORNING...WITH BLOWING SNOW. BMD //DISCUSSION...UPDATED 06Z... DEEP AREA OF LOW PRESSURE WILL CONTINUE TO LIFT ACROSS WISCONSIN OVERNIGHT WITH A TIGHT PRESSURE GRADIENT AND STRONG PRESSURE RISES ACROSS NORTHERN ILLINOIS RESULTING IN STRONG WESTERLY WINDS. WIND ARE EXPECTED TO CONTINUE TO GUST IN THE MID TO UPPER 30 KT RANGE OVERNIGHT THROUGH FRIDAY AFTERNOON...THEN SHOULD BEGIN TO TAPER LATE AFTERNOON INTO THE EVENING AS THE GRADIENT SLACKENS. CIGS ACROSS THE REGION ARE GENERALLY 015-025 TONIGHT AND EXPECT THESE LEVELS TO PERSIST OVERNIGHT. ANOTHER WAVE CURRENTLY OVER IOWA WILL MOVE ACROSS THE TERMINALS EARLY TO MID MORNING BRING ADDITIONAL LIGHT SNOW SHOWERS. MOISTURE IS FAIRLY SHALLOW THOUGH AND SOME MODELS MAINTAIN DRY CONDITIONS IN THE MORNING. WILL HAVE TO MONITOR UPSTREAM TRENDS AND MAY BE ABLE TO PULL MENTION OF SNOW/BLOWING SNOW IF THIS OCCURS. OTHERWISE...GIVEN THE STRONG WINDS...EXPECT EVEN LIGHT SNOW TO BLOW AROUND RESULTING IN MORE SIGNIFICANT REDUCTIONS IN VISIBILITY THAN OTHERWISE WOULD BE EXPECTED. BMD //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM-HIGH CONFIDENCE IN SPEED. * MEDIUM-HIGH CONFIDENCE IN CIG TRENDS...MEDIUM IN TIMING IMPROVEMENT TO VFR. * LOW CONFIDENCE IN HOW AREAS OF SNOW WILL EVOLVE OVERNIGHT. BMD //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... SATURDAY...VFR. SUNDAY...VFR. MONDAY...SLIGHT CHANCE OF LIGHT SNOW DURING THE AFTERNOON AND NIGHT OTHERWISE VFR. TUESDAY...VFR. WEDNESDAY...VFR. ED F && .MARINE... 302 AM CST STRONG LOW PRESSURE LIES OVER WISCONSIN EARLY THIS MORNING AND WILL LIFT NORTH ACROSS ONTARIO TO JAMES BAY BY LATE TONIGHT. MEANWHILE...A TIGHT PRESSURE GRADIENT WILL RESULT IN STRONG GALES AND STORM FORCE WINDS AT TIMES ACROSS LAKE MICHIGAN THROUGH THIS AFTERNOON. WILL LEAVE THE CURRENT TIMING IN PLACE FOR THE STORM WARNING...THOUGH LATEST PROJECTIONS INDICATE THAT IT MAY BE CANCELED EARLY. EITHER WAY...A GALE WARNING WILL BE NEEDED TO REPLACE THE STORM WARNING FOR A PERIOD LATE THIS AFTERNOON INTO THE EARLY OVERNIGHT HOURS. WINDS SHOULD FINALLY DIMINISH BELOW GALES LATE TONIGHT BUT WILL REMAIN AROUND 30 KT THROUGH THE REMAINDER OF THE WEEKEND. A BROAD RIDGE OF HIGH PRESSURE WILL BUILD FROM THE NORTHERN PLAINS INTO THE OHIO VALLEY AND REMAIN ANCHORED FOR MUCH OF THE UPCOMING WEEK...LEAVING LAKE MICHIGAN WITH PERSISTENT MODERATE WEST TO NORTHWEST WINDS NEXT WEEK. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023- ILZ032-ILZ033-ILZ039 UNTIL 3 PM FRIDAY. IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 3 PM FRIDAY. LM...STORM WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM FRIDAY. STORM WARNING...NEARSHORE WATERS UNTIL 4 AM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1139 PM CST Thu Feb 20 2014 .DISCUSSION... ISSUED 847 PM CST Thu Feb 20 2014 Cold front and associated convection has now pushed well to the east into Indiana, leaving behind windy and cooler conditions across central Illinois. Latest obs generally show winds in the 25 to 35 mph range, with gusts occasionally over 40 mph. Will continue with the High Wind Warning at this time, but this may need to be canceled early as upstream winds across Missouri have weakened even further. Made some minor adjustments to hourly temp grids to account for the colder air spilling into the region, but changes do not effect the going forecast. Therefore no zone update is needed at this time. Barnes && .AVIATION... ISSUED 1139 PM CST Thu Feb 20 2014 Strong W/SW winds will continue through the overnight hours, although they will not be quite as strong as earlier this evening. Based on latest obs and 00z numeric guidance, have lowered winds into the 15 to 20kt range with gusts to between 25 and 30kt. The strong/gusty winds will continue through Friday as well, before subsiding to around 10kt by evening. Main aviation challenge will be an area of MVFR clouds currently pushing eastward across Iowa/northern Missouri. Satellite timing tools bring these clouds into KSPI by 08z, then further east to KCMI between 09z and 10z. HRRR does not have a good handle on the clouds, but at least hints at ceilings overnight into early Friday morning. Have therefore cleared skies from west to east between 12z and 14z. Barnes && .PREV DISCUSSION... ISSUED 320 PM CST Thu Feb 20 2014 Short term issues revolve around a rapidly deepening low pressure system passing across far NW IL this afternoon, with a cold front racing across IL and into Indiana by 7 pm. Severe weather potential will progress east along and south of the warm front. Areas of very dense fog should dissipate behind the cold front as well. Very strong winds will develop as pressure rises reach 12mb per 3 hours. Wind speeds of 30-40 mph and gusts over 55 mph will develop shortly after the cold front passes. Flooding is already occurring across Knox and Stark counties where 2-2.5" of rain already fell earlier today. More rain from the line of thunderstorms could aggravate the flooding. Beyond the very busy short term, we have various short waves expected to move across IL between Friday night and Monday night. With the colder air also arriving this weekend, most of any precipitation that does develop should fall as snow. The models are producing widely varying solutions as to amount and coverage of any precip during that time, but we wanted to at least acknowledge the potential for precip due to at least 2 models showing some precipitation produced by each wave. SHORT TERM...Tonight through Sunday. A line of storms will race across IL just ahead of the cold front. Forward motion of the storms is being measured at 60 mph, with a low level jet of 70 kts just above the LCL. Storms are moving from to the N-NE towards areas with snow cover and more stable air near the ground. We expect to see localized damaging winds from the storm gust fronts in areas along and south of the warm front, which generally extends from Galesburg to Bloomington at this point. Isolated tornadoes could develop as wind shear rapidly increases just ahead of the cold front. As storms move farther north over snow covered areas, storms should begin to lose the ability to blast damaging winds through the stable low level airmass to the ground. The severe thunderstorm watch goes until 6 pm for out SW counties, but an additional watch will likely be needed farther east and south of the warm front as the cold front moves across IL. Dense fog has caused travel hazards for areas north of Rushville to Lincoln to Bloomington, and a dense fog advisory will go through 6 pm. Shortly behind the cold front, very strong pressure rises will produce very strong winds for several hours, with the strongest gusts possibly as high as 60 mph in the first 3-4 hours behind the front. Pressure rises diminish somewhat later this evening, but sustained winds will likely remain around 30 mph gusting to 40 mph at times until midnight. We may be able to remove some of the wind warning headline a little before 3 am as conditions warrant. A band of light rain or snow may move into our west-northwestern counties this evening through just after midnight, but little to no snow accumulation is expected. The axis of coldest air behind the cold front will pass across our forecast area around 12z/6am Friday morning. Clouds will begin to clear out of our SW areas around that time, but lows should still remain in the mid 20s north and upper 20 south. Warming occurs through the day on Friday, as 850mb temps climb from -8C or -9C at 6 am to zero to -2C at 6 pm. West-southwest winds will remain brisk and help to push high temps into the 40s across the board. The first shortwave that could produce some light snow is forecast to arrive Friday night. The GFS and Canadian have been consistently showing that feature and a dusting to a half inch of snow across the northern counties. The 12z Canadian did back off a little on the QPF, but the 12z ECMWF has started pointing towards forcing for precip during that time over that area as well. The airmass cools down for Saturday, as high pressure builds into IL from the NW. The GFS and Canadian once again team up on a shortwave for Sunday, producing 0.5" to 1" of snow across our W and N counties. The NAM indicates some snow for our southeastern counties Sunday afternoon, while the ECMWF is not resolving that feature as well. More noticeably cooler highs are forecast for Sunday as readings top out about 10-12F degrees colder than Saturday. LONG TERM...Monday through Thursday. The third shortwave is projected to arrive later Monday morning or Monday afternoon. There is some agreement on this by the GFS, Canadian, and ECMWF. With 3 models in general agreement, we increased PoPs into the chance category across the north, for another 0.5 to 1" of snow through early Monday evening. A stronger push of cold air will arrive behind that wave, as 850mb temps drop to -16C to -18C by Tuesday evening. Lows should reach into the single digits above zero north of Peoria to Bloomington Tues night, with single digits N of I-70 Wed night. The coldest highs this week look to be on Thursday as readings remain in the teens north of a line from Rushville to Champaign. Light snow may return late next Thursday afternoon and Thursday night as yet another shortwave pushes into the area. && .ILX WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY until 3 AM CST Friday FOR ILZ027>031-036>038- 040>057-061>063-066>068-071>073. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
705 PM EST SAT FEB 22 2014 .SYNOPSIS... ISSUED AT 608 PM EST SAT FEB 22 2014 SNOW WILL BE POSSIBLE OVERNIGHT MAINLY NEAR AND SOUTH OF HIGHWAY 24. ANY MIXED PRECIPITATION WILL QUICKLY CHANGE OVER TO ALL SNOW THIS EVENING AS COOLER AIR FILTERS IN. IT WILL LIKELY REMAIN DRY TONIGHT OVER EXTREME NORTHERN INDIANA AND SOUTHWEST LOWER MICHIGAN. CANADIAN HIGH PRESSURE WILL BRING COOL AND DRY CONDITIONS ON SUNDAY. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 421 PM EST SAT FEB 22 2014 MODELS CONTINUE TO SHOW STRONG SIGNAL FOR NARROW...SHORT DURATION MESOSCALE SNOW THIS EVENING INTO THE OVERNIGHT HOURS. RELIED HEAVILY ON HIRES GUIDANCE GIVEN SMALL SCALE NATURE TO THIS EVENT. PREVIOUS SHIFT LOCKED ONTO EVENT AND ADJUSTMENTS MADE BASED ON LATEST HRRR...RAP13 AND 12Z ARW EAST AND ARW NMM. RESULT IS A LITTLE NORTHWARD ADJUST TO POPS AND SNOW BUT NOT BY MUCH. THE HIGHWAY 24 CORRIDOR AND SOUTH STILL APPEAR IN LINE FOR A GENERAL 1 TO 3 WITH SMALL EMBEDDED AREA OF 2 TO 5 WITH ANY MESOBANDING THAT SETS UP. STRONG MID LEVEL FORCING DEPICTED WITH OMEGA FIELDS IN THE 15 TO 20 UBAR/S RANGE. FGEN FORCING STILL IMPRESSIVE IN THIS SAME AREA WITH MESOBANDING POTENTIAL SEEN ON VERTICAL CROSS SECTIONS. HIRES GUIDANCE HAS BEEN PICKING UP ON THIS WITH SOME IMPRESSIVE LIFT AND QPF AMOUNTS THIS EVENING BETWEEN ONE QUARTER AND ONE HALF INCH NEAR AND SOUTH OF HIGHWAY 24. INITIAL CONCERNS WITH DRIER LOW LEVEL AIR AND MOISTURE GOING INTO SATURATION CONTINUE. LITTLE PCPN HAS BEEN NOTED THROUGH 19Z UPSTREAM WHERE SOME OF THE HIRES GUIDANCE HAS BEEN SHOWING UP TO A TENTH OF AN INCH LIQUID ALREADY. RADAR MOSAIC HAS SHOWN MID LEVEL RETURNS BUT FEW IF ANY SURFACE REPORTS. SATELLITE SHOWS COOLING CLOUD TOPS AND A SHORT WAVE APPROACHING. COUPLED JET STREAKS EXPECTED OVER AREA BY 00Z AND AS THESE FEATURES COME TOGETHER EXPECT PCPN TO BEGIN SATURATING AND REACHING GROUND. HAVE LEANED AWAY FROM THE HIGHER END QPF GIVEN POOR EARLY PERFORMANCE UPSTREAM AND FOCUSED MORE ON A BLEND OF THE MID RANGE VALUES. 16Z HRRR DEPICTION OF SNOW DEVELOPING FROM NEAR KLAF TO KFWA BY 23Z REASONABLE AND SIMILAR TO LATEST RAP13. BRIEF PERIOD OF RAIN AT ONSET POSSIBLE WITH LOW LEVEL THERMAL FIELDS ABOVE FREEZING. HOWEVER...EVAPORATIVE COOLING EXPECTED TO QUICKLY COOL VERY SHALLOW WARM LAYER AND QUICKLY TRANSITION TO ALL SNOW. DISCUSSION WITH WPC AGREED WITH A GENERAL 1 TO 2 INCHES AND SMALLER AREA OF 2 TO 4 POSSIBLE WITH EXACT LOCATION REMAINING A BIT UNCERTAIN GIVEN SMALL SCALE BUT INTENSE FORCING. WOULD NOT RULE OUT A FEW 5 INCH REPORTS BUT WOULD EXPECT THIS TO BE VERY ISOLATED IN A NARROW BAND. TIMING SUGGEST HEAVIEST SNOW BETWEEN ABOUT 00Z AND 05Z WITH QUICK ENDING FROM WEST TO EAST. EXPECT A RATHER SHARP GRADIENT ON NORTHERN PERIPHERY OF SNOW AND THIS WILL LIKELY NEED SOME ADJUSTMENT THIS EVENING ONCE SNOW DEVELOPS AND TRENDS ASSESSED. DRIER AND COOLER AIR MOVES IN LATE TONIGHT AND FOR SUNDAY. && .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 421 PM EST SAT FEB 22 2014 A DOMINANT UPSTREAM RIDGE WILL NOT START TO BREAK DOWN UNTIL LATE THIS WEEK ALLOWING FOR A VERY COLD UPCOMING PERIOD WITH FLOW COMING FROM THE CANADIAN INTERIOR. OVERALL...THE GFS AND ECMWF WERE STRUGGLING WITH RUN TO RUN CONSISTENCY IN HANDLING THE TIMING AND EXTEND OF SUCCESSIVE SURGES OF ARCTIC AIR...ESPECIALLY LATE THIS UPCOMING WEEK. HOWEVER...THE CANADIAN GEM AND ITS ENSEMBLES HAVE KEPT A VERY CONSISTENT SIGNAL FOR THE PAST SEVERAL RUNS HANDLING THE COLD AIR WITH THE ENSEMBLE MEDIAN STAYING 20 TO 25 DEGREES BELOW NORMAL FROM TUESDAY THROUGH SUNDAY. FOR THIS PACKAGE...GIVEN THIS VARIABILITY AMONG THE ECMWF AND GFS...BUT STRONG SIGNAL FROM THE CANADIAN GEM AND ANALOGS...KEPT TEMPERATURES COLD WITH VIRTUALLY NO CHANGES FROM THE PREVIOUS FORECAST FOR WEDNESDAY THROUGH THE END OF THE WEEK. THE ECMWF WAS COLDER AGAIN WITH THE 12Z RUN...WITH 850 MB TEMPS NEAR -27C SATURDAY. GIVEN THE CLIMATOLOGICAL EXTREMES OF THESE TEMPERATURES...KEPT HIGHS MAINLY IN THE TEENS WEDNESDAY THROUGH SATURDAY WITH LOWS IN THE SINGLE DIGITS ABOVE ZERO...TO A LITTLE BELOW ZERO THURSDAY NIGHT. THESE HIGHS AND LOWS ARE WELL IN LINE WITH THE LATEST CANADIAN GEM/EPS GRAMS. OTHERWISE...KEPT THE FORECAST DRY EXCEPT FOR A CHANCE FOR SNOW MONDAY NIGHT WITH THE ARRIVAL OF A WEAK UPPER LEVEL TROF. THE ECMWF...ALTHOUGH STRUGGLING LATE IN THE FORECAST PERIOD...HAS A GOOD HANDLE ON A WEAK UPSTREAM SHORTWAVE THAT SHOULD ARRIVE MONDAY NIGHT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 702 PM EST SAT FEB 22 2014 CONCERN LIES WITH FINE LINE MESOSCALE BANDED PRECIPITATION ALONG AND NORTH OF RESPONSE TO INTENSE 850-800MB FRONTOGENETIC AXIS EMENATING FM WCNTL IL INTO NWRN OH. KFWA SHOULD REMAIN ON NRN MOST EDGE OF ENHANCED PRECIP ASSOCD WITH THIS FEATURE OVR THE NEXT FEW HOURS...BEFORE A MORE VEERED PROFILE BECOMES ESTABLISHED. PTYPE MAY MIX BRIEFLY RA/FZRA/PL...THOUGH PRIMARILY SN ANTICIPATED WITH TEMPO IFR VSBYS/FUELING RQRMNTS/PRECLUDING AS ALT TIL 02 UTC. THEREAFTER...WL CONT IMPROVING TREND AS SUCCINCT/STRONG 130 KT 4-3.5H JETLET PRESENTLY ACRS SRN LWR MI...AND FOCUS OF INTENSE/DEEP DIVERGENT SIGNAL...SLIDES EWD INTO LWR GRTLKS LATER THIS EVENING. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...KG SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...MURPHY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
608 PM EST SAT FEB 22 2014 .SYNOPSIS... ISSUED AT 608 PM EST SAT FEB 22 2014 SNOW WILL BE POSSIBLE TONIGHT MAINLY NEAR AND SOUTH OF HIGHWAY 24. ANY LIQUID PRECIPITATION WILL QUICKLY CHANGE OVER TO ALL SNOW THIS EVENING AS COOLER AIR FILTERS IN. IT WILL LIKELY REMAIN DRY TONIGHT OVER EXTREME NORTHERN INDIANA AND SOUTHWEST LOWER MICHIGAN. CANADIAN HIGH PRESSURE WILL BRING COOL AND DRY CONDITIONS ON SUNDAY. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 421 PM EST SAT FEB 22 2014 MODELS CONTINUE TO SHOW STRONG SIGNAL FOR NARROW...SHORT DURATION MESOSCALE SNOW THIS EVENING INTO THE OVERNIGHT HOURS. RELIED HEAVILY ON HIRES GUIDANCE GIVEN SMALL SCALE NATURE TO THIS EVENT. PREVIOUS SHIFT LOCKED ONTO EVENT AND ADJUSTMENTS MADE BASED ON LATEST HRRR...RAP13 AND 12Z ARW EAST AND ARW NMM. RESULT IS A LITTLE NORTHWARD ADJUST TO POPS AND SNOW BUT NOT BY MUCH. THE HIGHWAY 24 CORRIDOR AND SOUTH STILL APPEAR IN LINE FOR A GENERAL 1 TO 3 WITH SMALL EMBEDDED AREA OF 2 TO 5 WITH ANY MESOBANDING THAT SETS UP. STRONG MID LEVEL FORCING DEPICTED WITH OMEGA FIELDS IN THE 15 TO 20 UBAR/S RANGE. FGEN FORCING STILL IMPRESSIVE IN THIS SAME AREA WITH MESOBANDING POTENTIAL SEEN ON VERTICAL CROSS SECTIONS. HIRES GUIDANCE HAS BEEN PICKING UP ON THIS WITH SOME IMPRESSIVE LIFT AND QPF AMOUNTS THIS EVENING BETWEEN ONE QUARTER AND ONE HALF INCH NEAR AND SOUTH OF HIGHWAY 24. INITIAL CONCERNS WITH DRIER LOW LEVEL AIR AND MOISTURE GOING INTO SATURATION CONTINUE. LITTLE PCPN HAS BEEN NOTED THROUGH 19Z UPSTREAM WHERE SOME OF THE HIRES GUIDANCE HAS BEEN SHOWING UP TO A TENTH OF AN INCH LIQUID ALREADY. RADAR MOSAIC HAS SHOWN MID LEVEL RETURNS BUT FEW IF ANY SURFACE REPORTS. SATELLITE SHOWS COOLING CLOUD TOPS AND A SHORT WAVE APPROACHING. COUPLED JET STREAKS EXPECTED OVER AREA BY 00Z AND AS THESE FEATURES COME TOGETHER EXPECT PCPN TO BEGIN SATURATING AND REACHING GROUND. HAVE LEANED AWAY FROM THE HIGHER END QPF GIVEN POOR EARLY PERFORMANCE UPSTREAM AND FOCUSED MORE ON A BLEND OF THE MID RANGE VALUES. 16Z HRRR DEPICTION OF SNOW DEVELOPING FROM NEAR KLAF TO KFWA BY 23Z REASONABLE AND SIMILAR TO LATEST RAP13. BRIEF PERIOD OF RAIN AT ONSET POSSIBLE WITH LOW LEVEL THERMAL FIELDS ABOVE FREEZING. HOWEVER...EVAPORATIVE COOLING EXPECTED TO QUICKLY COOL VERY SHALLOW WARM LAYER AND QUICKLY TRANSITION TO ALL SNOW. DISCUSSION WITH WPC AGREED WITH A GENERAL 1 TO 2 INCHES AND SMALLER AREA OF 2 TO 4 POSSIBLE WITH EXACT LOCATION REMAINING A BIT UNCERTAIN GIVEN SMALL SCALE BUT INTENSE FORCING. WOULD NOT RULE OUT A FEW 5 INCH REPORTS BUT WOULD EXPECT THIS TO BE VERY ISOLATED IN A NARROW BAND. TIMING SUGGEST HEAVIEST SNOW BETWEEN ABOUT 00Z AND 05Z WITH QUICK ENDING FROM WEST TO EAST. EXPECT A RATHER SHARP GRADIENT ON NORTHERN PERIPHERY OF SNOW AND THIS WILL LIKELY NEED SOME ADJUSTMENT THIS EVENING ONCE SNOW DEVELOPS AND TRENDS ASSESSED. DRIER AND COOLER AIR MOVES IN LATE TONIGHT AND FOR SUNDAY. && .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 421 PM EST SAT FEB 22 2014 A DOMINANT UPSTREAM RIDGE WILL NOT START TO BREAK DOWN UNTIL LATE THIS WEEK ALLOWING FOR A VERY COLD UPCOMING PERIOD WITH FLOW COMING FROM THE CANADIAN INTERIOR. OVERALL...THE GFS AND ECMWF WERE STRUGGLING WITH RUN TO RUN CONSISTENCY IN HANDLING THE TIMING AND EXTEND OF SUCCESSIVE SURGES OF ARCTIC AIR...ESPECIALLY LATE THIS UPCOMING WEEK. HOWEVER...THE CANADIAN GEM AND ITS ENSEMBLES HAVE KEPT A VERY CONSISTENT SIGNAL FOR THE PAST SEVERAL RUNS HANDLING THE COLD AIR WITH THE ENSEMBLE MEDIAN STAYING 20 TO 25 DEGREES BELOW NORMAL FROM TUESDAY THROUGH SUNDAY. FOR THIS PACKAGE...GIVEN THIS VARIABILITY AMONG THE ECMWF AND GFS...BUT STRONG SIGNAL FROM THE CANADIAN GEM AND ANALOGS...KEPT TEMPERATURES COLD WITH VIRTUALLY NO CHANGES FROM THE PREVIOUS FORECAST FOR WEDNESDAY THROUGH THE END OF THE WEEK. THE ECMWF WAS COLDER AGAIN WITH THE 12Z RUN...WITH 850 MB TEMPS NEAR -27C SATURDAY. GIVEN THE CLIMATOLOGICAL EXTREMES OF THESE TEMPERATURES...KEPT HIGHS MAINLY IN THE TEENS WEDNESDAY THROUGH SATURDAY WITH LOWS IN THE SINGLE DIGITS ABOVE ZERO...TO A LITTLE BELOW ZERO THURSDAY NIGHT. THESE HIGHS AND LOWS ARE WELL IN LINE WITH THE LATEST CANADIAN GEM/EPS GRAMS. OTHERWISE...KEPT THE FORECAST DRY EXCEPT FOR A CHANCE FOR SNOW MONDAY NIGHT WITH THE ARRIVAL OF A WEAK UPPER LEVEL TROF. THE ECMWF...ALTHOUGH STRUGGLING LATE IN THE FORECAST PERIOD...HAS A GOOD HANDLE ON A WEAK UPSTREAM SHORTWAVE THAT SHOULD ARRIVE MONDAY NIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1227 PM EST SAT FEB 22 2014 A NARROW BUT INTENSE BAND OF SNOW IS EXPECTED TO DEVELOP THIS EVENING WITH KFWA SITTING NEAR THE NORTHERN FRINGE OF HEAVIEST SNOW BAND. KSBN EXPECTED TO REMAIN VFR WITH MID CLOUDS AT TIMES AND DRY CONDITIONS. SUBTLE WIND SHIFT TO WNW EXPECTED EARLY THIS EVENING. FURTHER SOUTH...AN INTENSE MESOSCALE BAND OF SNOW IS BEING DEPICTED TO DEVELOP BY MOST MODELS WITH SOME INTENSE RATES POSSIBLE FOR A BRIEF PERIOD. THIS BAND ONLY EXPECTED TO BE BETWEEN 50 AND 80 MILES WIDE AND MODELS SHOWING KFWA ANYWHERE FROM CENTER OF BAND TO JUST ON THE NORTHERN FRINGE. SATELLITE CURRENTLY SHOWS COOLING CLOUD TOPS UPSTREAM ACROSS NORTHERN MO AND SOUTHERN IL WHILE RADAR MOSAIC SHOWING MID LEVEL RETURNS DEVELOPING AS FAR EAST AS WESTERN INDIANA. CONTINUED WITH MVFR VIS AND CIGS IN LIGHT SNOW AT 23Z AT KFWA BUT ADDED AN IFR COMPONENT GIVEN DECENT MODEL AGREEMENT ON A PERIOD OF STRONG LIFT ACROSS SOUTHERN ALLEN COUNTY. LOWER VIS CERTAINLY POSSIBLE FOR A FEW HOURS BUT 00Z TAFS CAN SHOW THAT BASED ON DEVELOPING RADAR TRENDS AT THAT TIME. PCPN QUICKLY SHIFTS SOUTH AFTER 05Z WITH DRYING TOWARD DAYBREAK AND VFR CONDITIONS SUNDAY. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...AGD/KG SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
510 PM CST Sat Feb 22 2014 ...Updated aviation discussion... .SHORT TERM...(This evening through Sunday) ISSUED AT 128 PM CST SAT FEB 22 2014 Tonight: Northeasterly to easterly low level upslope flow is expected through the overnight hours. This will result in the formation of stratus across the region after midnight. Any precipitation is expected to remain north of the region in association with a 700 hPa baroclinic zone. Will stick with silent pop probabilities for now. Do have very high cloud cover in the grids in anticipation of the stratus. The saturated layer does not look thick enough for freezing drizzle attm. Overnight lows are forecast to be in the 20s. Tomorrow: More of the same continues with the upslope flow. Some partial clearing is expected as drier air works in. Still, should be cloudy for a good portion of the day, particularly across the north. Tomorrow will cooler with upper 30s by Hays to lower 40s near the Oklahoma border. .LONG TERM...(Sunday night through Saturday) ISSUED AT 331 PM CST SAT FEB 22 2014 A deep upper level trough will remain across eastern Canada and the Great Lakes into early March, delivering occasional shots of cold air from Canada into Kansas. Upper ridging will remain across western Canada for several days. Meanwhile, mid to high level flow will undercut the upper level ridge and progress into the southwestern United States and southern plains. Given the progressiveness of this southern stream, large amounts of precipitation are not expected. In the meantime, lee troughing and south winds will develop Monday in advance of a shortwave trough, with highs in the 50s and 60s across most of southwest Kansas. Some light snow may occur Tuesday as this shortwave trough rotates around the larger, eastern Canadian long wave trough in the wake of an arctic front. Highs on Tuesday will probably be in the 20s to lower 30s given the amount of cold air currently poised across southern Canada and the northern plains. The gfs and especially the NAM were disregarded for Tuesday`s forecast and the GEM/ECMWF were favored. The NAM is usually not worth considering that far out since since it`s a limited domain model. So we believe that the warmer solution for Tuesday is in error. Aside from Tuesday, temperatures will be fairly seasonal through the week. However, another shot of colder air may arrive by Saturday and remain for several days. A snow event can`t be ruled out around March 3rd as a shortwave trough in the southern stream approaches and interacts with cold air in place. But the models have been inconsistent with this scenario and lots of uncertainty still exists. Early March looks cold, especially relative to climatology. Eventually, if we keep the cold pattern, a shortwave trough in the southern stream could bring winter weather into western Kansas. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 507 PM CST SAT FEB 22 2014 An easterly upslope flow will continue overnight across western Kansas as an area of high pressure moves across the northern plains towards the mid Mississippi valley overnight. In addition the 18z BUFR soundings indicated that the lower levels of the atmosphere will moisten overnight as this upslope flow near the surface increases in depth. Based on the model soundings and the 20z HRRR will introduce increasing low clouds after midnight. At this time the ceilings are expected to be mainly between 1000 and 1500ft AGL. A brief period of IFR conditions at DDC and GCK not completely out of the question between 11z and 14z. Reduced visibilities due to fog at this time does not appear to be an issue tonight given the mixing potential near the surface from the 18z NAM BUFR sounding. && .PRELIMINARY POINT TEMPS/POPS... DDC 25 40 22 53 / 10 10 0 0 GCK 25 40 22 56 / 10 10 0 0 EHA 26 43 24 66 / 0 0 0 10 LBL 27 44 24 58 / 0 0 0 0 HYS 26 37 21 48 / 10 10 10 0 P28 28 42 25 52 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Sugden LONG TERM...Finch AVIATION...Burgert
AREA FORECAST DISCUSSION...CORRECTED
NWS BALTIMORE MD/WASHINGTON DC
456 AM EST FRI FEB 21 2014 .SYNOPSIS... A WARM FRONT IS POSITIONED ACROSS SOUTHERN VIRGINIA WHILE A COLD FRONT STRETCHES FROM OHIO TO ALABAMA. THE COLD FRONT WILL MOVE THROUGH THE MID ATLANTIC BY EARLY AFTERNOON. HIGH PRESSURE WILL RETURN OVER THE WEEKEND. UNSETTLED WEATHER IS POSSIBLE TUESDAY. && .NEAR TERM /TODAY/... QUITE A CHANGEABLE PD IN THE MID ATLC - CLOSE TO 1.5 FT OF SNOW ACROSS MUCH OF THE AREA A WK AGO HAS BEEN LARGELY MELTED AWAY. A CHECK OF SNOW ON THE GRND RECORDS (SOLELY IAD) SHOW IT IS INDEED HARD TO KEEP SNOWPACK ON GRND VERY LONG - IN 42 YRS OF RECORDS MORE THAN 1" OF SNOW ON GRND HAS ONLY RMND ON GRND LONGER THAN ONE WK 25 TIMES. RECORD LENGTH OF TIME WAS AT THE END OF 1969 - 23 DAYS. PRSNT SFC ANLYS/OBS SHOW A WARM FNT ALONG THE NC/VA BRDR CURVING UP INTO SERN VA. IN SOME LOCATIONS THERE`S A 15-20 TEMP DIFFERENCE OVR THE COURSE OF 20 MILES. AND TO OUR W IS A FAST MOVG CD FNT - THRU 3 AM CRW WAS ISSUING WRNGS ON IT: THEIR OFFICE RCVD A GUST TO 60 MPH AT 220 AM. THE CD FNT WL BE PUSHING INTO THE APLCHNS ARND 14Z...QUICKLY REACHING THE BAY ABT 5 HRS LATER. QUSTN THEN BECOMES HOW MUCH OF THE CD WEDGE ON THE N SIDE OF THE WARM FNT WL BE ERODED AWAY B4 THE CD FNT MOVES IN. THIS IN TURN MAKES FOR AN XTRMLY CHALLENGING TEMP FCST. USED HRRR 2M TEMP FIELD AS A GUIDE..AS WELL AS PAST HISTORY ON SYNTOPIC SITUATIONS SUCH AS THIS: SUSPECT THAT THE COLDER WEDGE WL NOT BE PUSHED OUT W/ THE XCPTN OF LWR SRN MD...WHERE IT MAY HAPPEN FOR AN HOUR OR TWO B4 THE CD FNT MOVES THRU. NEXT CONCERN IS SVR/WIND THREATS. THE TIME OF DAY THE FNT IS PASSING THRU IS NOT OPTIMAL FOR CNVCTV DVLPMNT...AND LTNG ACTVTY HAS BEEN DIMINISHING AND TRACKING FURTHER S AS THE NGT PROGRESSES. BUT AT THIS TIME OF YR LTNG IS NOT THE ONLY CONCERN...AS IS WITNESSED BY THE WRNGS/OBS BEING XPRNCD IN W.V. LOW TOPPED FAST MOVG STORMS CAN BRING STRONG WINDS TO THE SFC...AND IAD VWP IS SHOWING WINDS INXS OF 70 KT AT FL 040. WE HV ISSUED A WIND ADVSRY FOR THE HIGHER ELEVS BECAUSE OF THIS. TEMP FCST - CONFIDENCE IS NOT AT ITS HIGHEST...BUT MUCH OF THE AREA SHOULD SEE THE L50S FOR HIGHS...LWR SRN MD MAY END UP ABT TEN DEGS WRMR B4 THE CD FNT PUSHES THRU. && .SHORT TERM /TONIGHT/... TNGT IS A LESS CHALLENGING FCST AS HIGH PRES MOVES IN BEHIND THE FNT. LOWS IN THE 20S W OF THE BLUE RDG...30S ELSEWHERE. && .LONG TERM /SATURDAY THROUGH THURSDAY/... ZONAL FLOW ALOFT MOVES IN THIS WEEKEND BEHIND TODAY/S COLD FRONTAL PASSAGE. SATURDAY LOOKS TO BE A MILD DAY WITH ZONAL FLOW ALOFT...PLENTY OF SUNSHINE AND A SOUTHWEST WIND IN THE LOW LEVELS. THIS WILL BOOST TEMPERATURES WELL INTO THE 50S AND PERHAPS ABOVE 60 IN SOME AREAS SATURDAY AFTERNOON. SAT NGT THRU THU/... WE EXPECT INCREASING CLOUDS SATURDAY NIGHT INTO SUNDAY AS A SHORTWAVE APPROACHES. AT THE SURFACE...A COLD FRONTAL PASSAGE WILL OCCUR DURING THE DAY SUNDAY. ANOTHER SHORTWAVE ON THE HEELS OF THE FRONT MAY BRING A CHANCE OF SNOW SHOWERS SUNDAY NIGHT NEAR THE MASON DIXON LINE AND OVER THE POTOMAC HIGHLANDS. CANADIAN HIGH PRESSURE THEN BUILDS IN FOR MONDAY WITH A COLDER AIR MASS TAKING HOLD OVER THE MID ATLANTIC. THIS COLDER AIR MASS WILL NOT ONLY STICK AROUND THROUGH MID-WEEK BUT WILL LIKELY BE REINFORCED THROUGH THIS TIME. THERE IS STILL THE POTENTIAL FOR SOME WINTRY PRECIPITATION IN THE TUESDAY TO WEDNESDAY TIME FRAME...BUT UNCERTAINTY REMAINS REGARDING THE DETAILS INCLUDING TIMING AND STRENGTH. KEPT LOW CHANCE POPS IN THE FORECAST. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... CONDS WL BE DIMINISHING RAPIDLY THIS MRNG AS A FAST MOVG CD FNT ROLLS THRU THE MID ATLC AREA. IAD VWP IS SHOWING 70 KT AT FL 040...LLWX WL BE XPRNCD BY AIRCRAFT THIS MRNG. HVY RW DURG THE 11-18Z TIME WL CAUSE DIMINISHED CIGS AND VSBYS. VFR CONDS TNGT. SATURDAY INTO EARLY NEXT WEEK...NO SIGNIFICANT WX EXPECTED WITH A WEAK COLD FRONT SUNDAY AND THEN HIGH PRESSURE MONDAY. NEXT STORM APPROACHES WITH A CHANCE OF RAIN OR SNOW TUESDAY. && .MARINE... AN SCA IS IN EFFECT FOR ALL WATERS TDA. SMW`S MAY BE NEEDED... ESPECIALLY IN LWR TIDAL PTMC AND CHES BAY S OF DRUM PT DURG LATE MRNG/ERLY AFTN. HIGH PRESSURE BUILDS IN SATURDAY...THEN A COLD FRONT MOVES THROUGH SUNDAY. SCA IS LIKELY ON MONDAY IN NORTHWEST WINDS BEHIND THE FRONT. && .HYDROLOGY... WE`VE LOST UP TO ONE INCH OF SNOW WATER IN THE PAST TWO DAYS AREA WIDE. SNOW WATER EQUIVALENT VALUES ARE STILL QUITE HIGH IN THE FAR POTOMAC HIGHLANDS...BUT THE HIGHEST VALUES ARE MAINLY UPSTREAM OF JENNINGS RANDOLPH AND SAVAGE RIVER LAKES...AND THE OVERALL VALUES ARE MUCH LESS THAN OBSERVED IN PREVIOUS SNOWMELT FLOOD EVENTS. THERE WILL BE MORE MELT TODAY. THAT WILL BE ENOUGH TO CAUSE RIVER RISES AND THESE ARE REFLECTED IN THE CURRENT RIVER FORECASTS. RIGHT NOW NONE OF THE FORECASTS RISE TO FLOOD STAGE...BUT IF SNOWMELT OR RAIN AMOUNTS ON TODAY EXCEED THE CURRENT PROJECTIONS... SOME MINOR FLOODING WILL BE POSSIBLE... PARTICULARLY ON SMALLER CREEKS AND STREAMS AND OUR USUAL FIRST-TO-FLOOD SPOTS AMONG THE RIVER FORECAST POINTS. THE GRADUAL MELT RESUMES OVER THE WEEKEND...WITH FREEZES EACH NIGHT AND NO PRECIPITATION EXPECTED. COLDER WEATHER ARRIVES EARLY NEXT WEEK...SIGNIFICANTLY DECREASING OR STOPPING THE MELT FOR AWHILE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR MDZ501. VA...WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR VAZ025>027-029- 036>039-503-504. WV...WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR WVZ050-055- 501>506. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ532>534-537-540>543. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ530- 531-535-536-538-539. && $$ PRODUCTS,,,WOODY!/BPP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
348 AM EST FRI FEB 21 2014 .SYNOPSIS... A WARM FRONT IS POSITIONED ACROSS SOUTHERN VIRGINIA WHILE A COLD FRONT STRETCHES FROM OHIO TO ALABAMA. THE COLD FRONT WILL MOVE THROUGH THE MID ATLANTIC BY EARLY AFTERNOON. HIGH PRESSURE WILL RETURN OVER THE WEEKEND. UNSETTLED WEATHER IS POSSIBLE TUESDAY. && .NEAR TERM /TODAY/... QUITE A CHANGEABLE PD IN THE MID ATLC - CLOSE TO 1.5 FT OF SNOW ACROSS MUCH OF THE AREA A WK AGO HAS BEEN LARGELY MELTED AWAY. A CHECK OF SNOW ON THE GRND RECORDS (SOLELY IAD) SHOW IT IS INDEED HARD TO KEEP SNOWPACK ON GRND VERY LONG - IN 42 YRS OF RECORDS MORE THAN 1" OF SNOW ON GRND HAS ONLY RMND ON GRND LONGER THAN ONE WK 25 TIMES. RECORD LENGTH OF TIME WAS AT THE END OF 1969 - 23 DAYS. PRSNT SFC ANLYS/OBS SHOW A WARM FNT ALONG THE NC/VA BRDR. THE FNT HAS ACTUALLY PUSHED INTO SERN VA - IN SOME LOCATIONS THERE`S A 15-20 TEMP DIFFERENCE OVR THE COURSE OF 20 MILES. AND TO OUR W IS A FAST MOVG CD FNT - CRW HAS BEEN ISSUING WRNGS ON IT SINCE MDNGT: THEIR OFFICE RCVD A GUST TO 60 MPH AT 220 AM. THE CD FNT WL BE PUSHING INTO THE APLCHNS ARND 14Z...QUICKLY REACHING THE BAY ABT 5 HRS LATER. QUSTN THEN BECOMES HOW MUCH OF THE CD WEDGE ON THE N SIDE OF THE WARM FNT WL BE ERODED AWAY B4 THE CD FNT MOVES IN. THIS IN TURN MAKES FOR AN XTRMLY CHALLENGING TEMP FCST. USED HRRR 2M TEMP FIELD AS A GUIDE..AS WELL AS PAST HISTORY ON SYNTOPIC SITUATIONS SUCH AS THIS: SUSPECT THAT THE COLDER WEDGE WL NOT BE PUSHED OUT W/ THE XCPTN OF LWR SRN MD...WHERE IT MAY HAPPEN FOR AN HOUR OR TWO B4 THE CD FNT MOVES THRU. NEXT CONCERN IS SVR/WIND THREATS. THE TIME OF DAY THE FNT IS PASSING THRU IS NOT OPTIMAL FOR CNVCTV DVLPMNT...AND LTNG RMNS OVR NC AND PTS S. BUT AT THIS TIME OF YR LTNG IS NOT THE ONLY CONCERN...AS IS WITNESSED BY THE WRNGS/OBS BEING XPRNCD IN W.V. LOW TOPPED FAST MOVG STORMS CAN BRING STRONG WINDS TO THE SFC...AND IAD VWP IS SHOWING WINDS INXS OF 70 KT AT FL 040. WE HV ISSUED A WIND ADSRVY FOR THE HIGHER ELEVS BECAUSE OF THIS. TEMP FCST - CONFIDENCE IS NOT AT ITS HIGHEST...BUT MUCH OF THE AREA SHOULD SEE THE L50S FOR HIGHS...LWR SRN MD MAY END UP ABT TEN DEGS WRMR B4 THE CD FNT PUSHES THRU. && .SHORT TERM /TONIGHT/... TNGT IS A LESS CHALLENGING FCST AS HIGH PRES MOVES IN BEHIND THE FNT. LOWS IN THE 20S W OF THE BLUE RDG...30S ELSEWHERE. && .LONG TERM /SATURDAY THROUGH THURSDAY/... ZONAL FLOW ALOFT MOVES IN THIS WEEKEND BEHIND TODAY/S COLD FRONTAL PASSAGE. SATURDAY LOOKS TO BE A MILD DAY WITH ZONAL FLOW ALOFT...PLENTY OF SUNSHINE AND A SOUTHWEST WIND IN THE LOW LEVELS. THIS WILL BOOST TEMPERATURES WELL INTO THE 50S AND PERHAPS ABOVE 60 IN SOME AREAS SATURDAY AFTERNOON. SAT NGT THRU THU/... WE EXPECT INCREASING CLOUDS SATURDAY NIGHT INTO SUNDAY AS A SHORTWAVE APPROACHES. AT THE SURFACE...A COLD FRONTAL PASSAGE WILL OCCUR DURING THE DAY SUNDAY. ANOTHER SHORTWAVE ON THE HEELS OF THE FRONT MAY BRING A CHANCE OF SNOW SHOWERS SUNDAY NIGHT NEAR THE MASON DIXON LINE AND OVER THE POTOMAC HIGHLANDS. CANADIAN HIGH PRESSURE THEN BUILDS IN FOR MONDAY WITH A COLDER AIR MASS TAKING HOLD OVER THE MID ATLANTIC. THIS COLDER AIR MASS WILL NOT ONLY STICK AROUND THROUGH MID-WEEK BUT WILL LIKELY BE REINFORCED THROUGH THIS TIME. THERE IS STILL THE POTENTIAL FOR SOME WINTRY PRECIPITATION IN THE TUESDAY TO WEDNESDAY TIME FRAME...BUT UNCERTAINTY REMAINS REGARDING THE DETAILS INCLUDING TIMING AND STRENGTH. KEPT LOW CHANCE POPS IN THE FORECAST. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... CONDS WL BE DIMINISHING RAPIDLY THIS MRNG AS A FAST MOVG CD FNT ROLLS THRU THE MID ATLC AREA. IAD VWP IS SHOWING 70 KT AT FL 040...LLWX WL BE XPRNCD BY AIRCRAFT THIS MRNG. HVY RW DURG THE 11-18Z TIME WL CAUSE DIMINISHED CIGS AND VSBYS. VFR CONDS TNGT. SATURDAY INTO EARLY NEXT WEEK...NO SIGNIFICANT WX EXPECTED WITH A WEAK COLD FRONT SUNDAY AND THEN HIGH PRESSURE MONDAY. NEXT STORM APPROACHES WITH A CHANCE OF RAIN OR SNOW TUESDAY. && .MARINE... AN SCA IS IN EFFECT FOR ALL WATERS TDA. SMW`S MAY BE NEEDED... ESPECIALLY IN LWR TIDAL PTMC AND CHES BAY S OF DRUM PT DURG LATE MRNG/ERLY AFTN. HIGH PRESSURE BUILDS IN SATURDAY...THEN A COLD FRONT MOVES THROUGH SUNDAY. SCA IS LIKELY ON MONDAY IN NORTHWEST WINDS BEHIND THE FRONT. && .HYDROLOGY... WE`VE LOST UP TO ONE INCH OF SNOW WATER IN THE PAST TWO DAYS AREA WIDE. SNOW WATER EQUIVALENT VALUES ARE STILL QUITE HIGH IN THE FAR POTOMAC HIGHLANDS...BUT THE HIGHEST VALUES ARE MAINLY UPSTREAM OF JENNINGS RANDOLPH AND SAVAGE RIVER LAKES...AND THE OVERALL VALUES ARE MUCH LESS THAN OBSERVED IN PREVIOUS SNOWMELT FLOOD EVENTS. THERE WILL BE MORE MELT TODAY. THAT WILL BE ENOUGH TO CAUSE RIVER RISES AND THESE ARE REFLECTED IN THE CURRENT RIVER FORECASTS. RIGHT NOW NONE OF THE FORECASTS RISE TO FLOOD STAGE...BUT IF SNOWMELT OR RAIN AMOUNTS ON TODAY EXCEED THE CURRENT PROJECTIONS... SOME MINOR FLOODING WILL BE POSSIBLE... PARTICULARLY ON SMALLER CREEKS AND STREAMS AND OUR USUAL FIRST-TO-FLOOD SPOTS AMONG THE RIVER FORECAST POINTS. THE GRADUAL MELT RESUMES OVER THE WEEKEND...WITH FREEZES EACH NIGHT AND NO PRECIPITATION EXPECTED. COLDER WEATHER ARRIVES EARLY NEXT WEEK...SIGNIFICANTLY DECREASING OR STOPPING THE MELT FOR AWHILE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR MDZ501. VA...WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR VAZ025>027-029- 036>039-503-504. WV...WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR WVZ050-055- 501>506. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ532>534-537-540>543. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ530- 531-535-536-538-539. && $$ PRODUCTS,,,WOODY!/BPP
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1204 AM EST FRI FEB 21 2014 .SYNOPSIS... A WARM FRONT LIFTS NORTH OF THE REGION THIS MORNING. A COLD FRONT CROSSES THE AREA LATER TODAY. HIGH PRESSURE AND DRIER CONDITIONS RETURN FOR THE WEEKEND. && .NEAR TERM /OVERNIGHT/... LATEST MSAS SHOWING WARM FRONT LIFTG NORTH ACROSS THE AREA ATTM. QUITE A TEMP CONTRAST ACROSS THE AREA AT MIDNIGHT. CRNTLY 41 AT LKU RANGING TO 66 AT NTU. WILL DO A QUICK UPDATE TO ACCOUNT FOR THE 10+ DEGREE TEMP / DP TEMP RISE BEHIND WARM FRONT PAST FEW HOURS. WILL CALL THE MIDNIGHT OBS THE MIN TEMP ACROSS THE NORTH WITH RISING TMPS OVERNIGHT...OTW STDY 60-65. NAM12 SEEMS TO BEST DEPICT THE TMP CHANGES. PVS DSCN: VRB CLDS TO MCLDY ACRS THE FA. WARM FRONT RMNS SLO TO MOVE N THROUGH THE RGN THIS EVE...WILL DO SO...W/ LAST PLACES TO LOSE THE LO LVL WEDGE WNW OF RIC. MDLS DIFFER AS TO LO CIGS OR DEVELOPMENT. WILL INCLUDE AREAS OF FG OVR PORTIONS OF THE WTRS OVRNGT AS THE WARM AIR PUSHES NWD OVR THE COLDER BAY/OCN WTRS...OTRW CONTG W/ MNLY MCLDY SKY COVER. LO TEMPS ABT REACHED IN MOST PLACES...ESP SRN VA/NE NC. A RISE IN TEMPS XPCD IN ALL AREAS AS WARM FRONT CONTS N. HAVE CUTBACK POPS TO 20% AFTR 09Z WEST OF I95 FOR SLOWER ARRIVAL TO PCPN. DRY ELSEWHERE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... THE APPROACHING COLD FRONT WILL MOVE INTO THE WRN HALF OF THE CWA BY MID-LATE MORNING AND THEN CROSS THE ERN HALF DURING THE AFTN... PUSHING OFFSHORE DURING THE EVENING. THE BULK OF RAINFALL WILL OCCUR RIGHT ALONG AND BEHIND THE FRONT WHICH WILL THEN CONTINUE INTO FRIDAY EVENING BEFORE TAPERING OFF FROM WEST TO EAST. THERE ARE SEVERAL PARAMETERS THAT WILL SUPPORT THUNDERSTORM DEVELOPMENT ON FRIDAY DESPITE THE BEST DYNAMICS LYING WELL TO THE NORTH. THE AREA WILL BE LOCATED ALONG THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET PLUS THERE IS DECENT MID LEVEL INSTABILITY (850-500 MB) PRESENT...BOTH OF WHICH SUPPORT ENHANCED LIFT. 0-1 KM WIND SHEAR PROFILES VEER FROM SOUTH TO SOUTHWEST AND THEN BECOME UNIDIRECTIONAL FROM THE SOUTHWEST ABOVE 1 KM. THIS TYPE OF SHEAR PROFILE SUPPORTS THUNDERSTORM LINE SEGMENTS AND ULTIMATELY A THREAT FOR GUSTY THUNDERSTORM WINDS. AT THE SFC...SOUTH WINDS OF 15-20 MPH WILL INCREASE IN STRENGTH AND BECOME GUSTY JUST AHEAD OF THE COLD FRONTAL PASSAGE DURING THE LATE MORNING/EARLY AFTERNOON HOURS. NON-THUNDERSTORM WIND GUSTS SHOULD AVERAGE AROUND 30-35 MPH. MEANWHILE...THUNDERSTORM WIND GUSTS SHOULD RANGE FROM 30-50 MPH WITH LOCALLY HIGHER GUSTS POSSIBLE. PWATS INCREASE TO 1.00-1.50 INCHES DURING THE DAY. THIS WILL CONTRIBUTE TO THE POTENTIAL FOR MODERATE TO HEAVY RAINFALL AT TIMES...ESPECIALLY UNDER STRONGER STORM CORES. STORM TOTAL QPF SHOULD AVERAGE 0.50 INCHES WITH LOCALLY HIGHER AMOUNTS POSSIBLE DUE TO CONVECTION. TEMPERATURES WILL BE TRICKY AND HIGHLY DEPENDENT ON THE FROPA TIMING. TRENDING TWD A LATER ARRIVAL OF THE FRONT MEANS THAT TEMPS SHOULD TAKE ON MORE OF A NORMAL DIURNAL TREND...BUT MAY PEAK BY LATE MORNING FAR WRN AREAS AND BY EARLY AFTN FOR THE ERN HALF OF THE FA. HIGH TEMPS RANGE FROM THE LOWER 60S NW/N TO UPPER 60S SE (AROUND 70 COASTAL NE NC). PRECIP COMES TO AN END FRIDAY EVENING AS THE FRONT PUSHES WELL OFFSHORE. DECENT CLEARING AND WINDS BECOMING LIGHT WILL ALLOW TEMPS TO DROP INTO THE LOW-MID 30S NW TO UPPER 30S SE BY SATURDAY MORNING. HIGH PRESSURE AND DRIER CONDITIONS WILL PREVAIL SATURDAY INTO SUNDAY. HIGHS WILL GENERALLY BE IN THE 60S SAT/SUN WITH LOWS SUNDAY MORNING IN THE MID-UPPER 30S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... HIGH LATITUDES CONTINUE TO BE DOMINATED BY A DYNAMIC/HIGHLY AMPLIFIED PATTERN THROUGH THE EXTENDED. QUASI-ZONAL FLOW OVER THE CONUS TO BEGIN THE EXTENDED WILL AMPLIFY EARLY NEXT WEEK... CHARACTERIZED BY A MEAN RIDGE IN THE WEST AND DEEPENING TROUGH IN THE EAST. SHORTWAVE ENERGY IN THE NRN STREAM...ROUNDING THE BASE OF A STRONG -2 TO -3 STD DEV UPPER LOW...WILL IMPACT THE NE INTO THE MID- ATLANTIC THROUGH THE EXTENDED. HOWEVER...THESE WAVES ARE TYPICALLY DIFFICULT TO TIME AND THERE REMAINS LARGE SPREADS IN ENSEMBLE GUIDANCE AND DETERMINISTIC RUNS. THE FIRST WAVE WILL PUSH A CLIPPER FRONT THROUGH THE REGION SUN NIGHT-MON MORNING. FRONTAL PASSAGE ANTICIPATED TO BE DRY AS PROFILES SHOW LIMITED NRN STREAM MOISTURE AND WLY FLOW. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING FRONT MON. SPATIAL AND TIMING DIFFERENCES WITH THE SFC HIGH RESULT IN A TRICKY TEMP FORECAST MON AS LOW LEVEL THICKNESSES BTWN GFS/GEFS AND ECMWF ARE NEARLY 30 M. THE RESULT WOULD BE HIGHS IN THE MID 40S OR MID 50S. PREFERRED AN ENSEMBLE/WPC APPROACH TO SMOOTH OUT THE DIFFERENCES FOR THE TIME BEING WITH TEMPS SLIGHTLY BELOW SEASONAL NORMS (HIGHS MID 40S NORTH TO LOW 50S SOUTH). THE NEXT SHORTWAVE WILL TRAVERSE THE NE STATES TUES AS A WEAK SRN STREAM WAVE DEVELOPS A LOW ALONG THE STALLED COLD FRONT OVER THE GULF STATES. MODELS KEEP ANY MEASURABLE PRECIP SOUTH OF THE REGION...WHICH MATCHES WELL WITH THE DEEPENING TROUGH OVER THE ERN CONUS. WHILE CONDITIONS WILL REMAIN DRY TUES...DO ANTICIPATE INCREASING CLOUDS THROUGH THE DAY. MORE POTENT SHORTWAVE DIGGING OVER THE GREAT LAKES LATE TUES-TUES NIGHT AND INCREASING WINDS ALOFT WILL DEVELOP A STRONGER WAVE ALONG THE FRONT OFF THE SE COAST TUES NIGHT. LOW WILL LIFT OFF THE MID-ATLANTIC COAST WEDS MORNING. HAVE OPTED TO MAINTAIN SLIGHT CHANCE POPS INLAND DUE TO UNCERTAINTY (WHILE THE TREND MAY BE TO TAKE THEM OUT) BUT HAVE INCREASED THE COAST TO LOW END CHANCE POPS TUES NIGHT-WEDS MORNING. TEMPS MAY BE COLD ENOUGH FOR FROZEN PRECIP BUT CAA LOOKS MARGINAL DUE TO NO STRONG HIGH PRESSURE TO THE NORTHWEST...SO HAVE OPTED FOR RAIN OR SNOW WORDING AS FAR SOUTH AS CENTRAL VA. HIGH PRESSURE BUILDS IN FROM THE WEST WED AFTERNOON THROUGH THE END OF THE EXTENDED PERIOD...RESULTING IN MOSTLY CLEAR SKIES AND DRY/COOL CONDITIONS. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SOUTHERLY WINDS INCREASE OVERNIGHT AS A WARM FRONT MOVES NORTH THROUGH THE MID ATLANTIC STATES. MOST OF THE MODELS HAVE MOISTURE INCREASE IN THE LOWER PORTION OF THE BOUNDARY LAYER WITH IFR DEVELOPING NORTHWARD FROM THE GULF STREAM AND THROUGH EASTERN NORTH CAROLINA WITH A SIGNIFICANT INCREASE OF SURFACE DEW POINTS. WITH THE WIND...IFR SHOULD BE MAINLY DUE TO CIG RATHER THAN VSBY. FOLLOWED CLOSE TO THE NAM AND RUC FOR TIMING...GENERALLY AROUND 07Z. SBY ALREADY HAS MVFR CIGS AND RUC HAS A GOOD HANDLE ON THE SITUATION...WITH IFR PSBL DURING THE FIRST PART OF THE TAF PERIOD. ONCE THE AREA BECOMES WARM SECTORED EARLY FRIDAY MORNING... CONDITIONS MAY IMPROVE BUT FOR NOW KEPT IFR GOING UNTIL AROUND 15Z AS INDICATED BY MOS FCSTS AND MODEL SOUNDINGS...EXCEPT LIFTING EARLIER SE PORTIONS. GUSTY WINDS CONTINUE FRIDAY...STARTING FROM THE S/SW AND BACKING TO W/SW AS THE COLD FRONT MOVES THROUGH DURING THE AFTN. HAVE A FEW HOURS OF SHOWERS IN THE TAFS BEGINNING BETWEEN 15 AND 18Z. BRIEF IFR IS PSBL DURING HEAVIER SHOWERS. OUTLOOK...MAINLY DRY AND VFR CONDS ARE EXPECTED SATURDAY THROUGH TUESDAY. && .MARINE... AS OF 0430Z...WINDS INCREASING OVER THE SOUTHERN END OF THE BAY AS THE WARM FRONT MOVES THROUGH. SCA CONDITIONS WILL DEVELOP ACROSS THE WATERS DURING THE EARLY MORNING HOURS. WINDS OF SCA STRENGTH MAY BE INTERMITTENT DURING THE OVERNIGHT DUE TO THE COLD WATER TEMPERATURE BUT WILL INCREASE TO A MORE SOLID SCA DURING THE DAY FRIDAY. THE WINDS SHOULD EASILY TO SCA THRESHOLDS DURING THE DAY FRIDAY. FROM PREVIOUS DISCUSSION... GRADIENT WILL STRENGTHEN OVER THE WATERS IN ADVANCE OF A STRONG COLD FRONT WITH SLY WINDS REACHING SCA SPEEDS AROUND MIDNIGHT TONIGHT. WHILE A STRONG LOW LEVEL INVERSION WILL PREVENT THE STRONGEST WINDS ALOFT FROM REACHING THE WATER...PRESSURE FALLS AND THE TIGHT GRADIENT WILL PRODUCE WINDS OF 15-25 KT OVER THE BAY AND 20-30 KT OVER THE COASTAL WATERS. STRONG WINDS WILL CONTINUE INTO FRI BEFORE THE COLD FRONT CROSSES THE WATERS FRIDAY AFTERNOON. SHOWERS AND THUNDERSTORMS WILL ALSO ACCOMPANY THE FRONT...WHICH MAY PRODUCE STRONGER WIND GUSTS WITH CONVECTION. AS THE FRONT CROSSES THE WATERS AND WINDS BACK TO THE NW...ANTICIPATE A QUICK SURGE POST FRONTAL BEFORE WINDS DIMINISH FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE SOUTHWEST. WAVES MAY BRIEFLY INCREASE TO 4 FT AROUND MIDDAY FRIDAY ON THE BAY. MEANWHILE...SEAS WILL BUILD TO 5-6 FT ON THE SOUTHERN COASTAL WATERS...AND 6-8 FT ON THE NORTHERN COASTAL WATERS. HEADLINES ARE IN EFFECT FOR ALL WATERS FROM AFTER MIDNIGHT TONIGHT THROUGH 4PM FRIDAY. RIVERS DROP OFF FIRST BEFORE THE BAY AT 6PM AND THE NRN COASTAL WATERS AT MIDNIGHT FRI NIGHT. HIGH PRESSURE REMAINS OVER THE WATERS THROUGH THE WEEKEND BEFORE A CLIPPER FRONT CROSSES THE WATERS SUNDAY NIGHT- MONDAY MORNING. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR ANZ635>638. SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ630>634. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST FRIDAY NIGHT FOR ANZ650-652-654. SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR ANZ656-658. && $$ SYNOPSIS...MPR NEAR TERM...ALB/MPR SHORT TERM...BMD LONG TERM...SAM AVIATION...LSA MARINE...SAM/LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1154 PM EST THU FEB 20 2014 .SYNOPSIS... A WARM FRONT WILL NORTH OF THE REGION OVERNIGHT. A COLD FRONT CROSSES THE MID ATLANTIC REGION ON FRIDAY. HIGH PRESSURE AND DRIER CONDITIONS RETURN TO THE REGION DURING THE WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... VRB CLDS TO MCLDY ACRS THE FA. WARM FRONT RMNS SLO TO MOVE N THROUGH THE RGN THIS EVE...WILL DO SO...W/ LAST PLACES TO LOSE THE LO LVL WEDGE WNW OF RIC. MDLS DIFFER AS TO LO CIGS OR DEVELOPMENT. WILL INCLUDE AREAS OF FG OVR PORTIONS OF THE WTRS OVRNGT AS THE WARM AIR PUSHES NWD OVR THE COLDER BAY/OCN WTRS...OTRW CONTG W/ MNLY MCLDY SKY COVER. LO TEMPS ABT REACHED IN MOST PLACES...ESP SRN VA/NE NC. A RISE IN TEMPS XPCD IN ALL AREAS AS WARM FRONT CONTS N. HAVE CUTBACK POPS TO 20-30% (LATE TNGT) ALG/W OF I 95 FOR SLOWER ARRIVAL TO PCPN. ELSW...POPS AOB 10%. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... THE APPROACHING COLD FRONT WILL MOVE INTO THE WRN HALF OF THE CWA BY MID-LATE MORNING AND THEN CROSS THE ERN HALF DURING THE AFTN... PUSHING OFFSHORE DURING THE EVENING. THE BULK OF RAINFALL WILL OCCUR RIGHT ALONG AND BEHIND THE FRONT WHICH WILL THEN CONTINUE INTO FRIDAY EVENING BEFORE TAPERING OFF FROM WEST TO EAST. THERE ARE SEVERAL PARAMETERS THAT WILL SUPPORT THUNDERSTORM DEVELOPMENT ON FRIDAY DESPITE THE BEST DYNAMICS LYING WELL TO THE NORTH. THE AREA WILL BE LOCATED ALONG THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET PLUS THERE IS DECENT MID LEVEL INSTABILITY (850-500 MB) PRESENT...BOTH OF WHICH SUPPORT ENHANCED LIFT. 0-1 KM WIND SHEAR PROFILES VEER FROM SOUTH TO SOUTHWEST AND THEN BECOME UNIDIRECTIONAL FROM THE SOUTHWEST ABOVE 1 KM. THIS TYPE OF SHEAR PROFILE SUPPORTS THUNDERSTORM LINE SEGMENTS AND ULTIMATELY A THREAT FOR GUSTY THUNDERSTORM WINDS. AT THE SFC...SOUTH WINDS OF 15-20 MPH WILL INCREASE IN STRENGTH AND BECOME GUSTY JUST AHEAD OF THE COLD FRONTAL PASSAGE DURING THE LATE MORNING/EARLY AFTERNOON HOURS. NON-THUNDERSTORM WIND GUSTS SHOULD AVERAGE AROUND 30-35 MPH. MEANWHILE...THUNDERSTORM WIND GUSTS SHOULD RANGE FROM 30-50 MPH WITH LOCALLY HIGHER GUSTS POSSIBLE. PWATS INCREASE TO 1.00-1.50 INCHES DURING THE DAY. THIS WILL CONTRIBUTE TO THE POTENTIAL FOR MODERATE TO HEAVY RAINFALL AT TIMES...ESPECIALLY UNDER STRONGER STORM CORES. STORM TOTAL QPF SHOULD AVERAGE 0.50 INCHES WITH LOCALLY HIGHER AMOUNTS POSSIBLE DUE TO CONVECTION. TEMPERATURES WILL BE TRICKY AND HIGHLY DEPENDENT ON THE FROPA TIMING. TRENDING TWD A LATER ARRIVAL OF THE FRONT MEANS THAT TEMPS SHOULD TAKE ON MORE OF A NORMAL DIURNAL TREND...BUT MAY PEAK BY LATE MORNING FAR WRN AREAS AND BY EARLY AFTN FOR THE ERN HALF OF THE FA. HIGH TEMPS RANGE FROM THE LOWER 60S NW/N TO UPPER 60S SE (AROUND 70 COASTAL NE NC). PRECIP COMES TO AN END FRIDAY EVENING AS THE FRONT PUSHES WELL OFFSHORE. DECENT CLEARING AND WINDS BECOMING LIGHT WILL ALLOW TEMPS TO DROP INTO THE LOW-MID 30S NW TO UPPER 30S SE BY SATURDAY MORNING. HIGH PRESSURE AND DRIER CONDITIONS WILL PREVAIL SATURDAY INTO SUNDAY. HIGHS WILL GENERALLY BE IN THE 60S SAT/SUN WITH LOWS SUNDAY MORNING IN THE MID-UPPER 30S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... HIGH LATITUDES CONTINUE TO BE DOMINATED BY A DYNAMIC/HIGHLY AMPLIFIED PATTERN THROUGH THE EXTENDED. QUASI-ZONAL FLOW OVER THE CONUS TO BEGIN THE EXTENDED WILL AMPLIFY EARLY NEXT WEEK... CHARACTERIZED BY A MEAN RIDGE IN THE WEST AND DEEPENING TROUGH IN THE EAST. SHORTWAVE ENERGY IN THE NRN STREAM...ROUNDING THE BASE OF A STRONG -2 TO -3 STD DEV UPPER LOW...WILL IMPACT THE NE INTO THE MID- ATLANTIC THROUGH THE EXTENDED. HOWEVER...THESE WAVES ARE TYPICALLY DIFFICULT TO TIME AND THERE REMAINS LARGE SPREADS IN ENSEMBLE GUIDANCE AND DETERMINISTIC RUNS. THE FIRST WAVE WILL PUSH A CLIPPER FRONT THROUGH THE REGION SUN NIGHT-MON MORNING. FRONTAL PASSAGE ANTICIPATED TO BE DRY AS PROFILES SHOW LIMITED NRN STREAM MOISTURE AND WLY FLOW. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING FRONT MON. SPATIAL AND TIMING DIFFERENCES WITH THE SFC HIGH RESULT IN A TRICKY TEMP FORECAST MON AS LOW LEVEL THICKNESSES BTWN GFS/GEFS AND ECMWF ARE NEARLY 30 M. THE RESULT WOULD BE HIGHS IN THE MID 40S OR MID 50S. PREFERRED AN ENSEMBLE/WPC APPROACH TO SMOOTH OUT THE DIFFERENCES FOR THE TIME BEING WITH TEMPS SLIGHTLY BELOW SEASONAL NORMS (HIGHS MID 40S NORTH TO LOW 50S SOUTH). THE NEXT SHORTWAVE WILL TRAVERSE THE NE STATES TUES AS A WEAK SRN STREAM WAVE DEVELOPS A LOW ALONG THE STALLED COLD FRONT OVER THE GULF STATES. MODELS KEEP ANY MEASURABLE PRECIP SOUTH OF THE REGION...WHICH MATCHES WELL WITH THE DEEPENING TROUGH OVER THE ERN CONUS. WHILE CONDITIONS WILL REMAIN DRY TUES...DO ANTICIPATE INCREASING CLOUDS THROUGH THE DAY. MORE POTENT SHORTWAVE DIGGING OVER THE GREAT LAKES LATE TUES-TUES NIGHT AND INCREASING WINDS ALOFT WILL DEVELOP A STRONGER WAVE ALONG THE FRONT OFF THE SE COAST TUES NIGHT. LOW WILL LIFT OFF THE MID-ATLANTIC COAST WEDS MORNING. HAVE OPTED TO MAINTAIN SLIGHT CHANCE POPS INLAND DUE TO UNCERTAINTY (WHILE THE TREND MAY BE TO TAKE THEM OUT) BUT HAVE INCREASED THE COAST TO LOW END CHANCE POPS TUES NIGHT-WEDS MORNING. TEMPS MAY BE COLD ENOUGH FOR FROZEN PRECIP BUT CAA LOOKS MARGINAL DUE TO NO STRONG HIGH PRESSURE TO THE NORTHWEST...SO HAVE OPTED FOR RAIN OR SNOW WORDING AS FAR SOUTH AS CENTRAL VA. HIGH PRESSURE BUILDS IN FROM THE WEST WED AFTERNOON THROUGH THE END OF THE EXTENDED PERIOD...RESULTING IN MOSTLY CLEAR SKIES AND DRY/COOL CONDITIONS. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SOUTHERLY WINDS INCREASE OVERNIGHT AS A WARM FRONT MOVES NORTH THROUGH THE MID ATLANTIC STATES. MOST OF THE MODELS HAVE MOISTURE INCREASE IN THE LOWER PORTION OF THE BOUNDARY LAYER WITH IFR DEVELOPING NORTHWARD FROM THE GULF STREAM AND THROUGH EASTERN NORTH CAROLINA WITH A SIGNIFICANT INCREASE OF SURFACE DEW POINTS. WITH THE WIND...IFR SHOULD BE MAINLY DUE TO CIG RATHER THAN VSBY. FOLLOWED CLOSE TO THE NAM AND RUC FOR TIMING...GENERALLY AROUND 07Z. SBY ALREADY HAS MVFR CIGS AND RUC HAS A GOOD HANDLE ON THE SITUATION...WITH IFR PSBL DURING THE FIRST PART OF THE TAF PERIOD. ONCE THE AREA BECOMES WARM SECTORED EARLY FRIDAY MORNING... CONDITIONS MAY IMPROVE BUT FOR NOW KEPT IFR GOING UNTIL AROUND 15Z AS INDICATED BY MOS FCSTS AND MODEL SOUNDINGS...EXCEPT LIFTING EARLIER SE PORTIONS. GUSTY WINDS CONTINUE FRIDAY...STARTING FROM THE S/SW AND BACKING TO W/SW AS THE COLD FRONT MOVES THROUGH DURING THE AFTN. HAVE A FEW HOURS OF SHOWERS IN THE TAFS BEGINNING BETWEEN 15 AND 18Z. BRIEF IFR IS PSBL DURING HEAVIER SHOWERS. OUTLOOK...MAINLY DRY AND VFR CONDS ARE EXPECTED SATURDAY THROUGH TUESDAY. && .MARINE... AS OF 0430Z...WINDS INCREASING OVER THE SOUTHERN END OF THE BAY AS THE WARM FRONT MOVES THROUGH. SCA CONDITIONS WILL DEVELOP ACROSS THE WATERS DURING THE EARLY MORNING HOURS. WINDS OF SCA STRENGTH MAY BE INTERMITTENT DURING THE OVERNIGHT DUE TO THE COLD WATER TEMPERATURE BUT WILL INCREASE TO A MORE SOLID SCA DURING THE DAY FRIDAY. THE WINDS SHOULD EASILY TO SCA THRESHOLDS DURING THE DAY FRIDAY. FROM PREVIOUS DISCUSSION... GRADIENT WILL STRENGTHEN OVER THE WATERS IN ADVANCE OF A STRONG COLD FRONT WITH SLY WINDS REACHING SCA SPEEDS AROUND MIDNIGHT TONIGHT. WHILE A STRONG LOW LEVEL INVERSION WILL PREVENT THE STRONGEST WINDS ALOFT FROM REACHING THE WATER...PRESSURE FALLS AND THE TIGHT GRADIENT WILL PRODUCE WINDS OF 15-25 KT OVER THE BAY AND 20-30 KT OVER THE COASTAL WATERS. STRONG WINDS WILL CONTINUE INTO FRI BEFORE THE COLD FRONT CROSSES THE WATERS FRIDAY AFTERNOON. SHOWERS AND THUNDERSTORMS WILL ALSO ACCOMPANY THE FRONT...WHICH MAY PRODUCE STRONGER WIND GUSTS WITH CONVECTION. AS THE FRONT CROSSES THE WATERS AND WINDS BACK TO THE NW...ANTICIPATE A QUICK SURGE POST FRONTAL BEFORE WINDS DIMINISH FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM THE SOUTHWEST. WAVES MAY BRIEFLY INCREASE TO 4 FT AROUND MIDDAY FRIDAY ON THE BAY. MEANWHILE...SEAS WILL BUILD TO 5-6 FT ON THE SOUTHERN COASTAL WATERS...AND 6-8 FT ON THE NORTHERN COASTAL WATERS. HEADLINES ARE IN EFFECT FOR ALL WATERS FROM AFTER MIDNIGHT TONIGHT THROUGH 4PM FRIDAY. RIVERS DROP OFF FIRST BEFORE THE BAY AT 6PM AND THE NRN COASTAL WATERS AT MIDNIGHT FRI NIGHT. HIGH PRESSURE REMAINS OVER THE WATERS THROUGH THE WEEKEND BEFORE A CLIPPER FRONT CROSSES THE WATERS SUNDAY NIGHT- MONDAY MORNING. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR ANZ635>638. SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ630>634. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST FRIDAY NIGHT FOR ANZ650-652-654. SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR ANZ656-658. && $$ SYNOPSIS...ALB/BMD NEAR TERM...ALB/BMD SHORT TERM...BMD LONG TERM...SAM AVIATION...LSA MARINE...SAM/LSA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
627 PM EST SAT FEB 22 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 410 PM EST SAT FEB 22 2014 THE LOW THAT BROUGHT THE SNOW AND MIXED PRECIPITATION TO THE AREA THURSDAY EVENING INTO FRIDAY HAS BECOME STATIONARY NEAR CAPE HENRIETTA MARIA BETWEEN HUDSON BAY AND JAMES BAY. THIS NEARLY STATIONARY LOW WILL COMBINE WITH A 1028MB HIGH PRESSURE RIDGE SLIDING SOUTHEAST FROM A HIGH IN THE CANADIAN ROCKIES AND INTO THE NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO CREATE A TIGHT PRESSURE GRADIENT OVER THE UPPER GREAT LAKES THROUGH TONIGHT AND PART OF SUNDAY. THUS...THE WINDS AND RESULTING BLOWING SNOW (MAINLY OVER THE KEWEENAW) WILL BE THE PRIMARY CONCERN FOR TONIGHT INTO SUNDAY. WITH THIS TIGHT PRESSURE GRADIENT REMAINING IN PLACE FOR MUCH OF THE NIGHT AND COLDER AIR ALOFT SPILLING INTO THE REGION...WOULD EXPECT THE GUSTY CONDITIONS TO REMAIN THROUGH AT LEAST THE FIRST HALF OF THE NIGHT. EVEN OVER THE LAST COUPLE OF HOURS...WINDS AT KCMX HAVE FALLEN TO ONLY 35-40MPH. UPSTREAM AT ISLE ROYALE...WINDS ARE STILL GUSTING TO SIMILAR VALUES AND WITH MODELS SHOWING GUSTS TO 35KTS THROUGH BETWEEN 06-12Z...WILL FOLLOW THAT IDEA FOR THE KEWEENAW TONIGHT. SINCE MUCH OF THE SNOW HAS DIMINISHED AT KCMX...SEEING MORE OF A SPOTTY NATURE TO THE WORST VISIBILITIES ON WEBCAMS AND THE KCMX OBS. THUS...THINKING THAT THE GOING ENDING TIME FOR THE BLIZZARD WARNING IS REASONABLE AND THE EVENING SHIFT WILL BE ABLE TO LET IT EXPIRE. THE QUESTION IS WHETHER A ADVISORY WILL BE NEEDED TO COVER THE LINGERING BLOWING/DRIFTING SNOW OR IF IT COULD BE COVERED BY AN SPS. ALMOST LEANING TOWARDS AN SPS...BUT WILL ALLOW EVENING SHIFT TO SEE HOW VISIBILITIES ARE DOING OVER THE NEXT FEW HOURS AND THEN DECIDE. WITH THE CLEARING SKIES AND LITTLE VSBY RESTRICTIONS ON WEBCAMS IN GOGEBIC/ONTONAGON COUNTIES...HAVE CANCELLED THE EXISTING WINTER WX ADVISORY FOR THERE. OVER THE REST OF THE AREA...A SHORTWAVE THAT WAS OVER WESTERN ONTARIO THIS MORNING HAS SHIFTED EAST-SOUTHEAST AND IS MOVING ACROSS FAR NORTHERN LAKE SUPERIOR. WITH THIS TRACK...IT LOOKS LIKE THE DEEPER MOISTURE WILL HOLD OFF MOVING SOUTH OVER THE CWA UNTIL LATE TONIGHT AND ESPECIALLY INTO SUNDAY AFTERNOON. THUS...THINK MUCH OF THE CLOUDS AND SNOW CHANCES FOR MUCH OF THE SHORT TERM PERIOD WILL DEPEND ON LAKE EFFECT. WITH RAP ANALYZED 850MB TEMPS AROUND -17C AND MODELS SHOWING THAT FALLING TO -23C BY 00Z MONDAY...THERE IS PLENTY OF OVER LAKE INSTABILITY IF WATER IS PRESENT ON LAKE SUPERIOR. TODAY/S MODIS IMAGE SHOWS SOME OPEN WATER THAT HAS DEVELOPED OFF THE ARROWHEAD OF MINNESOTA AND ALSO TO THE EAST OF THE KEWEENAW. THEREFORE...WITH THE WESTERLY 925MB WINDS EXPECTED TONIGHT...HAVE FOCUSED CLOUD COVER AND SLIGHT TO LOW CHANCE POPS IN THE AREAS DOWNWIND OF THOSE PATCHES OF OPEN WATER. THIS MAINLY AFFECTS THE KEWEENAW PENINSULA. WITH WINDS SHIFTING A LITTLE MORE TO THE NORTHWEST ON SUNDAY AFTERNOON...HAVE SLOWLY TRANSITIONED POPS TOWARDS THAT DIRECTION. DIDN/T PUT MUCH FOR SNOWFALL AMOUNTS (ONLY AROUND AN INCH OR SO) INTO THE FORECAST DUE TO THE STRENGTH OF THE WINDS LIKELY LIMITING FETCH ACROSS THE OPEN WATER. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 410 PM EST SAT FEB 22 2014 NO MAJOR CHANGES EXPECTED TO THE LONG TERM FORECAST WITH MUCH BELOW NORMAL TEMPERATURES AND OCCASIONAL LIGHT SNOW CLOSE TO LAKE SUPERIOR. WITH THE ARCTIC AIRMASS ONCE AGAIN BUILDING ACROSS HUDSON BAY...THE COLDEST TEMPERATURES STILL LOOK TO BE WED-FRI WITH TEMPS STRUGGLING TO RISE ABOVE ZERO ONCE AGAIN. AS FOR THE DETAILS...THE DEEP LOW PRESSURE OVER JAMES BAY WILL CONTINUE TO FILL SUNDAY NIGHT THEN FINALLY MOVE EAST BY MONDAY IN RESPONSE TO A UPPER SHORT WAVE ROTATING AROUND THE UPPER LOW AND THROUGH THE REGION. THIS WILL ALLOW PBL WINDS TO VEER TO THE NW SUNDAY NIGHT. THIS VEERING OF WIND COMBINED WITH WEAK UPWARD MOTION ASSOCIATED WITH THE UPPER SHORT WAVE AND DEEPER MOISTURE SHOULD ALLOW FOR SOME LAKE EFFECT SNOW TO SPREAD A LITTLE FURTHER WEST PERHAPS TO THE ALGER/MARQUETTE COUNTY BORDER. IN ADDITION...LES SHOULD INCREASE ACROSS THE ENTIRE AREA NEAR LAKE SUPERIOR BUT THIS IS HIGHLY DEPENDENT ON THE FLUXES OVER THE SEMI-OPEN AREAS OF LAKE SUPERIOR. ONE WOULD THINK THAT WITH THE WIND OVER THE PAST FEW DAYS THAT THE ICE ON THE LAKE HAS BROKEN UP SOME. IN FACT...TODAY/S MODIS IMAGERY INDICATES THAT SEVERAL LARGER BREAKS HAVE OPENED ACROSS THE WESTERN LAKE AS WELL AS EAST OF THE KEWEENAW. IN FACT...WOULD NOT BE SHOCKED TO SEE A LITTLE MINI BAND OF ENHANCED LES JUST EAST OF THE KEWEENAW ORIENTED INTO FAR WESTERN ALGER COUNTY...ESPECIALLY IF WE CAN SEE ENHANCED LAKE BREEZE CONVERGENCE AS THE WINDS VEER TO NW. FOR NOW...WILL RAISE POPS TO 50 PCT ACROSS ALL OF ALGER INTO LUCE COUNTIES AND RAISE POPS TO CHC CATEGORY IN ERN MQT COUNTY. BEHIND THIS SHORT WAVE...LIGHT LES WILL CONTINUE IN THE KEWEENAW AND INTO ALGER/LUCE COUNTIES WITH NORTHWESTERLY CYCLONIC FLOW. ONCE AGAIN...IT IS STILL UNCLEAR IF FLUXES WILL INCREASE ENOUGH TO GENERATE LES OFF THE LAKE. AS SUCH...WILL CONTINUE WITH JUST CHANCE POPS. WINDS BACK TO WNW TUE AHEAD OF A WEAK SFC TROUGH...WHICH SHOULD ALLOW ANY LES TO SHIFT OFFSHORE EXCEPT FOR THE KEWEENAW. THE EXTENDED PERIOD...WED-SAT...CONTINUES TO LOOK EXTREMELY COLD. THE 12Z NWP CONTINUES TO BE IN VERY GOOD AGREEMENT IN SHOWING THE ARCTIC FRONT MOVING THROUGH THE UPPER GREAT LAKES WED NIGHT INTO THU MORNING...OPENING THE DOOR FOR ARCTIC AIR TO MOVE ACROSS THE REGION. MODELS STILL SHOW 850MB TEMPS DROPPING TO -30 TO -34C BY THU EVENING WHICH WILL CAUSE TEMPS TO STRUGGLE TO RISE ABOVE ZERO DURING THE DAY. SFC HIGH PRESSURE IS FCST TO QUICKLY BUILD ACROSS THE AREA THU NIGHT WHICH SHOULD ALLOW FOR EXCELLENT RADIATIVE COOLING...THUS DROPPING SFC TEMPS TO -20F OR LOWER. IF THE SKIES CLEAR AND WINDS GO LIGHT...THIS COULD BE ONE OF THOSE SITUATIONS SIMILAR TO EARLY MARCH 2003 WHERE NWS MQT SAW A MIN TEMP OF -31F. FOR NOW...WILL GO WITH LOWS FRIDAY MORNING -20 TO -25 BELOW. PERHAPS SOME MODERATION IN TEMPS BY SATURDAY WITH SLIGHT 850MB WARMING...BUT THE WINDS WILL ALSO BE INCREASING AS THE ARCTIC HIGH STRENGTHENS LEADING TO A TIGHTENING PRES GRADIENT ACROSS THE AREA. AS SUCH...APPARENT TEMPS WILL NOT FEEL MUCH DIFFERENT INTO THE WEEKEND. JUST TO NOTE...THE LATEST CFS /CLIMATE FORECAST SYSTEM/ GUIDANCE SHOWS MUCH OF MARCH WITH BELOW NORMAL TEMPERATURES... && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 627 PM EST SAT FEB 22 2014 WITH WEAKENING LOW PRES REMAINING IN THE VCNTY OF FAR NRN ONTARIO/JAMES BAY AND HIGH PRES CONTINUING TO RIDGE SE FROM THE SRN CANADIAN ROCKIES TO THE MID MISSISSIPPI VALLEY...BLUSTERY WESTERLY WINDS WILL CONTINUE THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW...BUT ESPECIALLY AT THE MORE EXPOSED KCMX SITE. WITH WINDS GUSTING OVER 30KT AT KCMX THRU THIS FCST PERIOD...BLSN WILL LIKELY KEEP PREVAILING VIS IN THE LIFR CATEGORY. EXPECT SOME FLUCTUATION WITH VIS IMPROVING TO IFR FOR BRIEF PERIODS. WITH THE WESTERLY WINDS AND SOME GAPS IN THE ICE OVER WESTERN LAKE SUPERIOR...THERE WILL BE OCNL -SHSN AT KCMX...WHICH WILL ASSIST THE LOWER VISIBILITIES. DISTURBANCE MAY INCREASE -SHSN COVERAGE SUN AFTN...AND THIS MAY RESULT IN VIS PERHAPS FALLING BLO 1/2SM AT TIMES. FOR KIWD/KSAW...VFR CONDITIONS SHOULD PREVAIL TONIGHT INTO SUN MORNING AS WESTERLY WINDS WON`T BE FAVORABLE FOR LAKE EFFECT CLOUDS/-SHSN. DEEPER MOISTURE/DISTURBANCE ROTATING INTO THE AREA DURING THE DAY SUNDAY COULD PRODUCE A MORE SOLID MVFR CLOUD DECK AS WELL AS SOME -SHSN/FLURRIES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 410 PM EST SAT FEB 22 2014 A TIGHT PRESSURE GRADIENT BETWEEN A LOW NEAR HUDSON BAY AND A HIGH PRESSURE RIDGE MOVING INTO THE MID MISSISSIPPI VALLEY WILL CONTINUE TO PRODUCE WESTERLY GALE FORCE GUSTS TO 35-40KTS TONIGHT. AS THE LOW WEAKENS ON SUNDAY...THE GRADIENT WILL WEAKEN AND LEAD TO WINDS DROPPING TO 30KTS. NORTHWESTERLY WINDS WILL CONTINUE SUNDAY NIGHT INTO THE FIRST HALF OF THE UPCOMING WORK WEEK...WITH GUSTS UP TO 25KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... BLIZZARD WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ001-003. LAKE SUPERIOR... GALE WARNING UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR LSZ240>246- 263>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...MRD AVIATION...ROLFSON MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
910 AM MST FRI FEB 21 2014 .UPDATE... CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE BUT HAVE MADE A FEW ADJUSTMENTS WITH THIS MORNINGS UPDATE. RADAR CURRENTLY SHOWING NUMEROUS SNOW SHOWERS DEVELOPING ALONG THE BEARTOOTH FOOTHILLS AND PRYOR MOUNTAINS WITH SOME NARROW NORTHWEST TO SOUTHEAST SNOW BANDS FROM AROUND BILLINGS WESTWARD TO THE FOOTHILLS. HAVE RAISED POPS TO LIKELY FOR THE ENTIRE DAY AS HRRR MODELS SHOWING AREAS OF SNOWBANDS THROUGHOUT THE DAY ACROSS OUR CENTRAL AND WESTERN LOCATIONS. EXPECT SCATTERED SNOW SHOWERS EAST OF BILLINGS WITH MORE NUMEROUS SNOW SHOWERS FROM BILLINGS WESTWARD. ACCUMULATIONS ARE EXPECTED TO BE GENERALLY LESS THAN AN INCH BUT AREAS THAT ARE UNDER ANY TRAINING SNOW BANDS MAY PICK UP A QUICK INCH OR TWO. WILL BE MONITORING THESE SNOW BANDS THROUGHOUT THE DAY AS LATER UPDATES MAY BE NECESSARY ALONG WITH POSSIBLE ADVISORIES. HOOLEY && .SHORT TERM...VALID FOR TDY AND SAT... NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH SATURDAY...WITH A SERIES OF SHORTWAVES MOVING SOUTHEASTWARD THROUGH THE REGION. SATELLITE SHOWS ONE SHORTWAVE THAT IS GENERATING SOME SNOW SHOWERS...MOVING THROUGH EASTERN MONTANA...WHILE A MORE POTENT SHORTWAVE IS ABOUT TO ENTER NORTHWEST MONTANA. AS THAT SHORTWAVE MOVES THROUGH THE CWA TODAY INTO TONIGHT...IT WILL WORK WITH STRONG LOW TO MID LEVEL INSTABILITY AND ATTENDANT PACIFIC MOISTURE TO GENERATE MORE SNOW SHOWERS. THE SYSTEM IS NOT TREMENDOUSLY ORGANIZED...SO A WIDESPREAD SNOW EVENT DOES NOT APPEAR LIKELY. WITH THE INSTABILITY AND OROGRAPHIC ENHANCEMENT...THOUGH...WE WILL SEE SOME PRECIP BANDS FORM...SO IT WOULD NOT SURPRISE ME TO SEE SOME LOCALIZED REPORTS OF A COUPLE OF INCHES OF SNOW WHERE THESE BANDS DO SET UP...PARTICULARLY OVER AND DOWNSTREAM OF THE CRAZIES...LITTLE BELTS...BIG SNOWIES AND BEARTOOTH MOUNTAINS. SOME UPSLOPE FLOW MAY ALSO ENHANCE THE SNOWFALL POTENTIAL IN THE BEARTOOTH FOOTHILLS NEAR RED LODGE AND NYE. HIGH TEMPERATURES TODAY ARE EXPECTED TO REACH THE UPPER 20S TO UPPER 30S. THE LOWER ATMOSPHERE SHOULD BE WELL MIXED TODAY...ESPECIALLY NEAR SHOWER ACTIVITY...SO IT WILL BE FAIRLY WINDY. A MODIFIED ARCTIC AIRMASS WILL MOVE INTO THE REGION TONIGHT INTO SATURDAY BEHIND THE SHORTWAVE. THIS WILL INCREASE FRONTOGENESIS AND UPSLOPE FLOW ACROSS THE WESTERN HALF OF THE REGION AT THE SAME TIME MORE SHORTWAVE ENERGY AND JET ENERGY INFLUENCE THE REGION. IT WILL NOT BE QUITE AS UNSTABLE IN THE LOW TO MID LEVELS...BUT THE AFOREMENTIONED FORCING MECHANISMS WILL WORK WITH OROGRAPHIC ENHANCEMENT IN NW FLOW ALOFT TO CONTINUE TO PRODUCE SNOW IN THE HIGHER TERRAIN AS WELL AS SOME SNOWBANDS. AGAIN...SOME ACCUMULATING SNOW IS LIKELY ACROSS THE WESTERN HALF OF THE REGION...WITH LOCAL ENHANCEMENT IN THE MOUNTAINS AND WITHIN ANY BAND THAT SETS UP. TEMPERATURES WILL BE QUITE A BIT COLDER SATURDAY AS HIGHS ARE ONLY EXPECTED TO REACH THE TEENS TO LOW 20S. STC .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... GREAT AGREEMENT ON ALL MODELS FOR AN UNSEASONABLY COLD STRETCH OF WEATHER WITH A GREAT CHANCE AT A PROLONGED PERIOD OF ACCUMULATING SNOW SUNDAY THROUGH MONDAY. STRONG SHORTWAVE TROUGH DROPS OUT OF CANADA AND SLIDES INTO THE NORTHERN PLAINS SUNDAY WHILE A FLAT UPPER RIDGE MOVES TOWARD THE GREAT BASIN. THIS PROCESS WILL ALLOW COLD AIR TO DROP INTO THE FORECAST AREA WITH -20C ADVERTISED AT 850MB. THE FLAT RIDGE TO THE WEST WILL ALLOW PACIFIC MOISTURE TO STREAM OVER THE COLD AIR AND PRODUCE OVER RUNNING SNOWFALL. THE 285K SURFACE ADVERTISES THE STRONGEST INSENTROPIC ASCENT ON SUNDAY NIGHT INTO EARLY MONDAY FOR MOST OF THE AREA. THE ISENTROPIC LIFT WILL GET GOING SATURDAY NIGHT OVER THE WEST AND THEN KICK INTO SOUTH CENTRAL MONTANA SUNDAY MORNING AND THEN CRANK UP LATE SUNDAY AFTERNOON AND SUNDAY NIGHT. HAVE RAISED POPS MOST LOCATIONS AND STARTED SNOW A LITTLE EARLIER. SNOW WILL CONTINUE THROUGH THE DAY MONDAY AND VERY SLOWLY TAPER OFF OVER WESTERN AND CENTRAL ZONES MONDAY NIGHT. RAISED POPS MONDAY NIGHT AS MODEL RUNS CONTINUE TO DELAY DRYING FROM THE NORTH. WILL EASILY SEE 4 TO 8 INCHES OF SNOW OVER THE TWO DAY PERIOD. TEMPERATURES WILL BE COLD FOR THIS TIME OF YEAR WITH HIGHS IN THE SINGLE DIGITS TO LOWER TEENS SUNDAY AND MONDAY. THE COLDEST NIGHT WILL LIKELY BE MONDAY NIGHT WITH READINGS FALLING BELOW ZERO. A REINFORCING SHOT OF COLD AIR WILL PLOW THROUGH THE AREA ON TUESDAY BUT WILL BE LIMITED WITH MOISTURE. THIS WILL SERVE TO KEEP THINGS UNSEASONABLY COLD AROUND HERE. SUBTLE WARMING SHOULD TAKE PLACE WEDNESDAY AND THURSDAY IN LOW LEVEL DOWNSLOPE. MODELS WERE POINTING TO ANOTHER SHOT OF COLD AIR TO PUSH IN FRIDAY AND SATURDAY. TWH && .AVIATION... SCATTERED SNOW SHOWERS CAN BE EXPECTED TODAY...ALONG WITH 20-35KT NORTHWEST WIND GUSTS. THE HEAVIER SNOW SHOWERS WILL DROP CONDITIONS TO IFR LOCALLY. MOUNTAINS WILL BE FREQUENTLY OBSCURED. VFR WILL PREVAIL OUTSIDE OF THE SHOWER ACTIVITY. TWH && .PRELIMINARY POINT TEMP/POPS... TDY SAT SUN MON TUE WED THU ------------------------------------------------------- BIL 037 014/022 006/015 001/010 902/017 009/023 008/022 6/J 55/S 48/S 97/S 41/B 00/U 12/S LVM 032 007/020 901/016 002/016 000/023 012/032 011/026 6/J 64/S 48/S 97/S 52/S 01/B 13/S HDN 037 015/024 009/018 003/011 904/018 004/025 004/023 6/J 54/S 38/S 97/S 31/B 00/U 12/S MLS 034 011/020 001/013 901/006 000/013 001/018 904/013 4/J 32/S 13/S 74/S 10/U 00/U 12/S 4BQ 035 014/023 008/018 003/010 902/017 002/023 002/020 4/J 33/S 14/S 87/S 31/B 00/U 12/S BHK 029 006/017 001/010 907/003 905/011 904/017 910/012 6/J 32/S 12/S 63/S 10/U 00/U 01/B SHR 034 013/019 003/020 004/014 902/020 005/028 005/024 5/J 45/S 46/S 87/S 51/B 01/U 12/S && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
940 PM CST SAT FEB 22 2014 .UPDATE... ISSUED AT 939 PM CST SAT FEB 22 2014 PER COORDINATION AND WHERE CURRENT SNOW BAND IS SETTING UP...HAVE EXPANDED WINTER WEATHER ADVISORY TO INCLUDE FURNAS AND HARLAN COUNTIES. UPDATE ISSUED AT 859 PM CST SAT FEB 22 2014 COMPLICATED FORECAST AS WE HEAD INTO TONIGHT AS TO WHERE SNOW BANDS WILL SET UP. HAVE BEEN MONITORING SNOW BAND ACROSS WESTERN NEB WHICH HAS MIGRATED EASTWARD EARLY THIS EVENING. DRIER AIR TO THE EAST HAS BEEN SLOW TO OVERCOME BUT A SNOW BAND HAS MANAGED TO MOVE IN AND IS ORIENTED W/E GENERALLY FM KLBF TO KLXN TO KHDE AND POINTS JUST TO THE SOUTH. THE SNOW IS ALIGNED FAIRLY WELL WITH THE MID LEVEL FRONTOGENESIS WHICH IS PRIMARILY PROGGED ALONG OUR WESTERN CWA THROUGH THE FIRST PART OF THE NIGHT. HAVE EXPANDED OUR CURRENT WINTER WX ADVISORY TO INCLUDE PHELPS AND KEARNEY COUNTIES WHERE SNOW HAS COMMENCED AND A LONGER DURATION OF SNOW IS EXPECTED. AS WE HEAD INTO TONIGHT WE SEE AN INCREASE IN ISENTROPIC LIFT AS INDICATED ON THE 290K SURFACE AND THE LIFT PERSISTS FOR SEVERAL HOURS...INTO SUNDAY MORNING. THE UPPER JET STREAK NOSES ACROSS WESTERN NEB SUNDAY MORNING WITH LIFT CONTINUING SUNDAY MORNING IN LFQ OF JET. ONE OF THE MORE NOTABLE CHANGES IN THE LATEST MODEL RUNS THAT SNOW IS EXPECTED TO PERSIST LONGER SUNDAY MORNING WITH ADDITIONAL LIGHT ACCUMULATIONS POSSIBLE. SNOW AMOUNTS WILL BE DEPENDENT UPON SNOW BANDS WITH SEVERAL INCHES...AND LOCALLY HEAVY SNOWFALL POSSIBLE WITHIN THE BANDS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 407 PM CST SAT FEB 22 2014 ...ABOVE NORMAL UNCERTAINTY TONIGHT IN A SWATH OF SNOW THAT COULD END UP DUMPING 6-8 INCHES "IF" THE WORST CASE UNFOLDS... ALOFT: VERY LOW AMPLITUDE WNW CYCLONIC FLOW WILL REMAIN OVER THE CNTRL PLAINS THRU SUN. WV IMAGERY SHOWS A SUBTLE SHORTWAVE TROF OVER BRITISH COLUMBIA. PART OF THIS TROF WILL RACE THRU TONIGHT. SURFACE: A COLD FRONT MOVED THRU LAST NIGHT AND CURRENTLY EXTENDED FROM ST. LOUIS-OKLAHOMA CITY-LUBBOCK TX. THIS FRONT WILL SLOWLY SAG DEEPER INTO TX/AR BY SUNSET SUNDAY. MEANWHILE...CANADIAN HIGH PRES WILL GRADUALLY BUILD S THRU THE PLAINS. REST OF THIS AFTERNOON: INCREASING CLOUDS OVER S-CNTRL NEB WILL OBSCURE THE SUN WHILE N-CNTRL KS SHOULD SEE A NICE END TO THE DAY. HIGH TEMPS WILL OCCUR 4-5 PM. TONIGHT: BECOMING CLOUDY WITH A BAND OF SNOW DEVELOPING ACROSS THE FCST AREA AND IT COULD BECOME HEAVY IN A VERY NARROW SWATH OVER S-CNTRL NEB. PROBABILITIES OF NO SNOW AT ALL ARE HIGHEST OVER N-CNTRL KS. THIS WILL BE A JET STREAK DRIVEN EVENT AS WIND/MASS ADJUSTMENTS RESULT IN WARM AIR ADVECTION AND FRONTOGENESIS /FGEN/ ON THE FRONT THAT MOVED THRU LAST NIGHT. CROSS SECTIONS INDICATE MID- LEVEL UPRIGHT INSTABILITY AND LIFT WILL BE STRONG IN THE DENDRITIC GROWTH ZONE /DGZ/. SEVERAL SCENARIOS ARE POSSIBLE TONIGHT AND WE WILL REALLY NOT KNOW WHICH ONE IS RIGHT UNTIL WE SEE THIS UNFOLD. THIS FCST IS FRAUGHT WITH UNCERTAINTY AND WE ARE ADMITTEDLY CONSERVATIVE ON SNOW AMOUNTS AND THE AERIAL EXTENT OF THE ADVISORY. BE PREPARED FOR ADJUSTMENTS LATER THIS EVENING AND TONIGHT THAT COULD RESULT IN DRAMATICALLY INCREASING OR DECREASING AMOUNTS FOR YOUR AREA. 09Z AND 15Z SREF PROBABILITIES FOR .25" ARE HIGHEST IN THE ADVISORY AREA. THE 15Z PROBS FOR .25" ARE HIGHER THAN 09Z AND THE 70% CHANCE OF .25" NOW EXTENDS E TO GRI. THE 19Z RAP SUPPORTS THIS. A CHECK OF THE 18Z NAM HAS .25" TO HASTINGS. SNOW TOTALS: GENERALLY 1-3" OVER S-CNTRL NEB. 2-3" FROM THE TRI-CITIES WESTWARD...AND 3-4" PRIMARILY OVER DAWSON COUNTY. THIS IS OUR BEST STAB USING A BLEND THE 00Z/06Z/12Z MULTI-MODEL QPF. THAT PRESENTS A PROBLEM. TOO MUCH AVERAGING SHOULD HIT THE SWATH OF SNOW CORRECTLY...BUT IT MAY BE TOO BROAD COMPARED TO REALITY AND FCST AMOUNTS MAY NOT BE HIGH ENOUGH. SNOW-LIQUID RATIOS: USED PRIMARILY 15:1 THRU THE EVENING AND CLOSE TO 20:1 AFTER MIDNIGHT. GIVEN THE STRENGTH OF THE LIFT IN THE DGZ... THESE RATIOS COULD ALSO BE CONSERVATIVE. POSSIBLE WEAKNESSES IN TONIGHT/S FCST: 1) WE MAY BE TOO BROAD WITH THE EDGES OF THE SNOW BAND...I.E. IT MAY BE MORE NARROW THAN DEPICTED. 2) DO WE HAVE THE HIGHEST POPS IN THE RIGHT LOCATION? THE HI-RES GEM HAS THE BAND BETWEEN I-80 AND THE KS BORDER. WE ARE IN THE I-80 CORRIDOR. 3) DEWPOINTS MAY BE TOO HIGH N OF I-80. DEWPOINTS IN THE SINGLE DIGITS ARE AS CLOSE AS O`NEILL. ADVECTION OF THIS VERY DRY AIR WILL PLAY A ROLE IN LIMITING THE NRN EXTENT OF THE BAND. 4) ARE AMOUNTS HIGH ENOUGH? WOULD NOT BE SURPRISED TO SEE A NARROW STRIP OF WARNING LEVEL SNOW /6-8"/ SOMEWHERE GIVEN THE RATIOS WE ARE LIKELY TO SEE. UNCERTAINTY: PLEASE KEEP IN MIND THAT THERE ARE SOME AREAS THAT HAVE SNOW IN THE FCST...BUT WILL SEE NO SNOW AT ALL. THIS ESPECIALLY APPLIES IF THE FCST PROBABILITY OF SNOW AT YOUR LOCATION IS 40% OR BELOW. THERE WILL BE A SHARP CUT-OFF ON THE NRN AND SRN FRINGES OF THIS BAND. THE SMALL SCALE NATURE OF THIS BAND IS PROBLEMATIC FOR PINNING DOWN DETAILS...BUT THIS COULD END UP A WARNING LEVEL EVENT FOR SOME COUNTIES. LOW TEMPS WERE FROM CONSENSUS OF 2M TEMPS WHICH RAISED TEMPS SEVERAL DEGREES. SUN: FGEN LIFTS N AND MID-LEVELS DRY OUT WITH STABILITY RETURNING. PATCHES OF LIGHT SNOW WILL LINGER THRU MID-MORNING...BUT THE ACCUMULATING SNOW WILL ESSENTIALLY BE OVER. PLENTY OF CLOUDS WILL REMAIN AND A FEW FLURRIES COULD REDEVELOP N AND W OF THE TRI- CITIES IN THE AFTERNOON. HIGH TEMPS HAVE A LOT OF CONTINUITY WITH THE 4 AM GID FCST. THE ONLY CHANGE WAS TO NUDGE TEMPS DOWN E OF HWY 281. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 407 PM CST SAT FEB 22 2014 THE BIG STORY WILL BE THE WELL BELOW NORMAL TEMPERATURES ALONG WITH SEVERAL CHANCES OF WINTRY PRECIPITATION. HIGH TEMPERATURES THROUGH THE PERIOD WILL GENERALLY AVERAGE 10 TO 15 DEGREES BELOW NORMAL. SUNDAY NIGHT AND MONDAY...MID LEVEL ISENTROPIC LIFT WILL RESULT IN SOME LOW END LIGHT SNOW CHANCES PRIMARILY ACROSS OUR NORTHERN ZONES WITH THE BETTER SNOW CHANCES WELL NORTH OF OUR FORECAST AREA ACROSS SOUTH DAKOTA. ALTHOUGH NOT IN THE OFFICIAL FORECAST AS OF RIGHT NOW...WILL ALSO NEED TO WATCH OUT FOR THE POSSIBILITY OF LIGHT FREEZING DRIZZLE ACROSS OUR NORTHERN AND WESTERN ZONES LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. ANY FREEZING DRIZZLE WOULD PRIMARILY BE CONFINED TO OUR WESTERN AND NORTHERN ZONES. THE 12Z GFS AND ECMWF DO NOT REALLY SHOW MUCH IN THE WAY OF FREEZING DRIZZLE POTENTIAL...BUT THE 12Z AND 18Z NAM DO INDICATE SOME POTENTIAL WITH LOW LEVEL SATURATION BENEATH A DRY MID LEVEL. THE NAM IS STILL A BIT OF AN OUTLIER AND THE POTENTIAL EVEN IN THE NAM IS SO MARGINAL THAT WE WILL CONTINUE TO LEAVE FREEZING DRIZZLE OUT OF THE FORECAST FOR NOW. ANY SNOW AMOUNTS WOULD LIKELY BE VERY LIGHT AND LESS THAN ONE HALF INCH. MONDAY NIGHT THROUGH TUESDAY...A SHORTWAVE TROUGH WILL TRACK SOUTHEAST OUT OF CANADA. ASSOCIATED UPPER JET DYNAMICS AND A PROGRESSIVE BAND OF MID LEVEL FRONTOGENESIS WILL LEAD TO ADDITIONAL CHANCES FOR LIGHT SNOW. NOT EXPECTING MUCH SNOW AT THIS TIME WITH MOST PLACES SEEING FLURRIES UP TO 1 INCH. COLDER AIR WILL FILTER IN ON TUESDAY WITH HIGHS STUCK IN THE 20S FOR MOST AREAS. WEDNESDAY THROUGH SATURDAY...WILL TRANSITION FROM A NORTHWESTERLY FLOW PATTERN TO A MORE ZONAL PATTERN...WITH PERHAPS EVEN THE DEVELOPMENT OF A TROUGH OVER THE WESTERN CONUS LATE IN THE PERIOD. OVERALL...THIS IS MORE LIKELY BE A DRY AND COOL PERIOD FOR OUR FORECAST AREA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 521 PM CST SAT FEB 22 2014 THE MAIN FORECAST ISSUE DURING THE TAF PERIOD IS THE DEVELOPMENT OF A FRONTOGENETIC BAND OF SNOWFALL OVERNIGHT AND INTO SUNDAY MORNING. SNOW HAS ALREADY DEVELOPED ACROSS WESTERN NEBRASKA AND THE SNOW SHOULD REACH KGRI AROUND 06Z WITH SNOW CONTINUING THROUGH THE NIGHT. SNOW ACCUMULATION FOR KGRI IS EXPECTED TO RANGE FROM 1 TO 3 INCHES. AS THE SNOW DEVELOPS/FALLS...CONDITIONS WILL DROP TO IFR OR POTENTIALLY LIFR. AS THE SNOW ENDS ON SUNDAY...VSBYS AND CIGS WILL IMPROVE BUT KEPT AFTN CIGS AT MVFR. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR NEZ060-061- 072>074-082-083. KS...NONE. && $$ UPDATE...FAY SHORT TERM...HALBLAUB LONG TERM...WESELY AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
920 PM CST SAT FEB 22 2014 .UPDATE... ISSUED AT 859 PM CST SAT FEB 22 2014 COMPLICATED FORECAST AS WE HEAD INTO TONIGHT AS TO WHERE SNOW BANDS WILL SET UP. HAVE BEEN MONITORING SNOW BAND ACROSS WESTERN NEB WHICH HAS MIGRATED EASTWARD EARLY THIS EVENING. DRIER AIR TO THE EAST HAS BEEN SLOW TO OVERCOME BUT A SNOW BAND HAS MANAGED TO MOVE IN AND IS ORIENTED W/E GENERALLY FM KLBF TO KLXN TO KHDE AND POINTS JUST TO THE SOUTH. THE SNOW IS ALIGNED FAIRLY WELL WITH THE MID LEVEL FRONTOGENESIS WHICH IS PRIMARILY PROGGED ALONG OUR WESTERN CWA THROUGH THE FIRST PART OF THE NIGHT. HAVE EXPANDED OUR CURRENT WINTER WX ADVISORY TO INCLUDE PHELPS AND KEARNEY COUNTIES WHERE SNOW HAS COMMENCED AND A LONGER DURATION OF SNOW IS EXPECTED. AS WE HEAD INTO TONIGHT WE SEE AN INCREASE IN ISENTROPIC LIFT AS INDICATED ON THE 290K SURFACE AND THE LIFT PERSISTS FOR SEVERAL HOURS...INTO SUNDAY MORNING. THE UPPER JET STREAK NOSES ACROSS WESTERN NEB SUNDAY MORNING WITH LIFT CONTINUING SUNDAY MORNING IN LFQ OF JET. ONE OF THE MORE NOTABLE CHANGES IN THE LATEST MODEL RUNS THAT SNOW IS EXPECTED TO PERSIST LONGER SUNDAY MORNING WITH ADDITIONAL LIGHT ACCUMULATIONS POSSIBLE. SNOW AMOUNTS WILL BE DEPENDENT UPON SNOW BANDS WITH SEVERAL INCHES...AND LOCALLY HEAVY SNOWFALL POSSIBLE WITHIN THE BANDS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 407 PM CST SAT FEB 22 2014 ...ABOVE NORMAL UNCERTAINTY TONIGHT IN A SWATH OF SNOW THAT COULD END UP DUMPING 6-8 INCHES "IF" THE WORST CASE UNFOLDS... ALOFT: VERY LOW AMPLITUDE WNW CYCLONIC FLOW WILL REMAIN OVER THE CNTRL PLAINS THRU SUN. WV IMAGERY SHOWS A SUBTLE SHORTWAVE TROF OVER BRITISH COLUMBIA. PART OF THIS TROF WILL RACE THRU TONIGHT. SURFACE: A COLD FRONT MOVED THRU LAST NIGHT AND CURRENTLY EXTENDED FROM ST. LOUIS-OKLAHOMA CITY-LUBBOCK TX. THIS FRONT WILL SLOWLY SAG DEEPER INTO TX/AR BY SUNSET SUNDAY. MEANWHILE...CANADIAN HIGH PRES WILL GRADUALLY BUILD S THRU THE PLAINS. REST OF THIS AFTERNOON: INCREASING CLOUDS OVER S-CNTRL NEB WILL OBSCURE THE SUN WHILE N-CNTRL KS SHOULD SEE A NICE END TO THE DAY. HIGH TEMPS WILL OCCUR 4-5 PM. TONIGHT: BECOMING CLOUDY WITH A BAND OF SNOW DEVELOPING ACROSS THE FCST AREA AND IT COULD BECOME HEAVY IN A VERY NARROW SWATH OVER S-CNTRL NEB. PROBABILITIES OF NO SNOW AT ALL ARE HIGHEST OVER N-CNTRL KS. THIS WILL BE A JET STREAK DRIVEN EVENT AS WIND/MASS ADJUSTMENTS RESULT IN WARM AIR ADVECTION AND FRONTOGENESIS /FGEN/ ON THE FRONT THAT MOVED THRU LAST NIGHT. CROSS SECTIONS INDICATE MID- LEVEL UPRIGHT INSTABILITY AND LIFT WILL BE STRONG IN THE DENDRITIC GROWTH ZONE /DGZ/. SEVERAL SCENARIOS ARE POSSIBLE TONIGHT AND WE WILL REALLY NOT KNOW WHICH ONE IS RIGHT UNTIL WE SEE THIS UNFOLD. THIS FCST IS FRAUGHT WITH UNCERTAINTY AND WE ARE ADMITTEDLY CONSERVATIVE ON SNOW AMOUNTS AND THE AERIAL EXTENT OF THE ADVISORY. BE PREPARED FOR ADJUSTMENTS LATER THIS EVENING AND TONIGHT THAT COULD RESULT IN DRAMATICALLY INCREASING OR DECREASING AMOUNTS FOR YOUR AREA. 09Z AND 15Z SREF PROBABILITIES FOR .25" ARE HIGHEST IN THE ADVISORY AREA. THE 15Z PROBS FOR .25" ARE HIGHER THAN 09Z AND THE 70% CHANCE OF .25" NOW EXTENDS E TO GRI. THE 19Z RAP SUPPORTS THIS. A CHECK OF THE 18Z NAM HAS .25" TO HASTINGS. SNOW TOTALS: GENERALLY 1-3" OVER S-CNTRL NEB. 2-3" FROM THE TRI-CITIES WESTWARD...AND 3-4" PRIMARILY OVER DAWSON COUNTY. THIS IS OUR BEST STAB USING A BLEND THE 00Z/06Z/12Z MULTI-MODEL QPF. THAT PRESENTS A PROBLEM. TOO MUCH AVERAGING SHOULD HIT THE SWATH OF SNOW CORRECTLY...BUT IT MAY BE TOO BROAD COMPARED TO REALITY AND FCST AMOUNTS MAY NOT BE HIGH ENOUGH. SNOW-LIQUID RATIOS: USED PRIMARILY 15:1 THRU THE EVENING AND CLOSE TO 20:1 AFTER MIDNIGHT. GIVEN THE STRENGTH OF THE LIFT IN THE DGZ... THESE RATIOS COULD ALSO BE CONSERVATIVE. POSSIBLE WEAKNESSES IN TONIGHT/S FCST: 1) WE MAY BE TOO BROAD WITH THE EDGES OF THE SNOW BAND...I.E. IT MAY BE MORE NARROW THAN DEPICTED. 2) DO WE HAVE THE HIGHEST POPS IN THE RIGHT LOCATION? THE HI-RES GEM HAS THE BAND BETWEEN I-80 AND THE KS BORDER. WE ARE IN THE I-80 CORRIDOR. 3) DEWPOINTS MAY BE TOO HIGH N OF I-80. DEWPOINTS IN THE SINGLE DIGITS ARE AS CLOSE AS O`NEILL. ADVECTION OF THIS VERY DRY AIR WILL PLAY A ROLE IN LIMITING THE NRN EXTENT OF THE BAND. 4) ARE AMOUNTS HIGH ENOUGH? WOULD NOT BE SURPRISED TO SEE A NARROW STRIP OF WARNING LEVEL SNOW /6-8"/ SOMEWHERE GIVEN THE RATIOS WE ARE LIKELY TO SEE. UNCERTAINTY: PLEASE KEEP IN MIND THAT THERE ARE SOME AREAS THAT HAVE SNOW IN THE FCST...BUT WILL SEE NO SNOW AT ALL. THIS ESPECIALLY APPLIES IF THE FCST PROBABILITY OF SNOW AT YOUR LOCATION IS 40% OR BELOW. THERE WILL BE A SHARP CUT-OFF ON THE NRN AND SRN FRINGES OF THIS BAND. THE SMALL SCALE NATURE OF THIS BAND IS PROBLEMATIC FOR PINNING DOWN DETAILS...BUT THIS COULD END UP A WARNING LEVEL EVENT FOR SOME COUNTIES. LOW TEMPS WERE FROM CONSENSUS OF 2M TEMPS WHICH RAISED TEMPS SEVERAL DEGREES. SUN: FGEN LIFTS N AND MID-LEVELS DRY OUT WITH STABILITY RETURNING. PATCHES OF LIGHT SNOW WILL LINGER THRU MID-MORNING...BUT THE ACCUMULATING SNOW WILL ESSENTIALLY BE OVER. PLENTY OF CLOUDS WILL REMAIN AND A FEW FLURRIES COULD REDEVELOP N AND W OF THE TRI- CITIES IN THE AFTERNOON. HIGH TEMPS HAVE A LOT OF CONTINUITY WITH THE 4 AM GID FCST. THE ONLY CHANGE WAS TO NUDGE TEMPS DOWN E OF HWY 281. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 407 PM CST SAT FEB 22 2014 THE BIG STORY WILL BE THE WELL BELOW NORMAL TEMPERATURES ALONG WITH SEVERAL CHANCES OF WINTRY PRECIPITATION. HIGH TEMPERATURES THROUGH THE PERIOD WILL GENERALLY AVERAGE 10 TO 15 DEGREES BELOW NORMAL. SUNDAY NIGHT AND MONDAY...MID LEVEL ISENTROPIC LIFT WILL RESULT IN SOME LOW END LIGHT SNOW CHANCES PRIMARILY ACROSS OUR NORTHERN ZONES WITH THE BETTER SNOW CHANCES WELL NORTH OF OUR FORECAST AREA ACROSS SOUTH DAKOTA. ALTHOUGH NOT IN THE OFFICIAL FORECAST AS OF RIGHT NOW...WILL ALSO NEED TO WATCH OUT FOR THE POSSIBILITY OF LIGHT FREEZING DRIZZLE ACROSS OUR NORTHERN AND WESTERN ZONES LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. ANY FREEZING DRIZZLE WOULD PRIMARILY BE CONFINED TO OUR WESTERN AND NORTHERN ZONES. THE 12Z GFS AND ECMWF DO NOT REALLY SHOW MUCH IN THE WAY OF FREEZING DRIZZLE POTENTIAL...BUT THE 12Z AND 18Z NAM DO INDICATE SOME POTENTIAL WITH LOW LEVEL SATURATION BENEATH A DRY MID LEVEL. THE NAM IS STILL A BIT OF AN OUTLIER AND THE POTENTIAL EVEN IN THE NAM IS SO MARGINAL THAT WE WILL CONTINUE TO LEAVE FREEZING DRIZZLE OUT OF THE FORECAST FOR NOW. ANY SNOW AMOUNTS WOULD LIKELY BE VERY LIGHT AND LESS THAN ONE HALF INCH. MONDAY NIGHT THROUGH TUESDAY...A SHORTWAVE TROUGH WILL TRACK SOUTHEAST OUT OF CANADA. ASSOCIATED UPPER JET DYNAMICS AND A PROGRESSIVE BAND OF MID LEVEL FRONTOGENESIS WILL LEAD TO ADDITIONAL CHANCES FOR LIGHT SNOW. NOT EXPECTING MUCH SNOW AT THIS TIME WITH MOST PLACES SEEING FLURRIES UP TO 1 INCH. COLDER AIR WILL FILTER IN ON TUESDAY WITH HIGHS STUCK IN THE 20S FOR MOST AREAS. WEDNESDAY THROUGH SATURDAY...WILL TRANSITION FROM A NORTHWESTERLY FLOW PATTERN TO A MORE ZONAL PATTERN...WITH PERHAPS EVEN THE DEVELOPMENT OF A TROUGH OVER THE WESTERN CONUS LATE IN THE PERIOD. OVERALL...THIS IS MORE LIKELY BE A DRY AND COOL PERIOD FOR OUR FORECAST AREA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 521 PM CST SAT FEB 22 2014 THE MAIN FORECAST ISSUE DURING THE TAF PERIOD IS THE DEVELOPMENT OF A FRONTOGENETIC BAND OF SNOWFALL OVERNIGHT AND INTO SUNDAY MORNING. SNOW HAS ALREADY DEVELOPED ACROSS WESTERN NEBRASKA AND THE SNOW SHOULD REACH KGRI AROUND 06Z WITH SNOW CONTINUING THROUGH THE NIGHT. SNOW ACCUMULATION FOR KGRI IS EXPECTED TO RANGE FROM 1 TO 3 INCHES. AS THE SNOW DEVELOPS/FALLS...CONDITIONS WILL DROP TO IFR OR POTENTIALLY LIFR. AS THE SNOW ENDS ON SUNDAY...VSBYS AND CIGS WILL IMPROVE BUT KEPT AFTN CIGS AT MVFR. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR NEZ060-061- 072>074. KS...NONE. && $$ UPDATE...FAY SHORT TERM...HALBLAUB LONG TERM...WESELY AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
533 PM CST SAT FEB 22 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 407 PM CST SAT FEB 22 2014 ...ABOVE NORMAL UNCERTAINTY TONIGHT IN A SWATH OF SNOW THAT COULD END UP DUMPING 6-8 INCHES "IF" THE WORST CASE UNFOLDS... ALOFT: VERY LOW AMPLITUDE WNW CYCLONIC FLOW WILL REMAIN OVER THE CNTRL PLAINS THRU SUN. WV IMAGERY SHOWS A SUBTLE SHORTWAVE TROF OVER BRITISH COLUMBIA. PART OF THIS TROF WILL RACE THRU TONIGHT. SURFACE: A COLD FRONT MOVED THRU LAST NIGHT AND CURRENTLY EXTENDED FROM ST. LOUIS-OKLAHOMA CITY-LUBBOCK TX. THIS FRONT WILL SLOWLY SAG DEEPER INTO TX/AR BY SUNSET SUNDAY. MEANWHILE...CANADIAN HIGH PRES WILL GRADUALLY BUILD S THRU THE PLAINS. REST OF THIS AFTERNOON: INCREASING CLOUDS OVER S-CNTRL NEB WILL OBSCURE THE SUN WHILE N-CNTRL KS SHOULD SEE A NICE END TO THE DAY. HIGH TEMPS WILL OCCUR 4-5 PM. TONIGHT: BECOMING CLOUDY WITH A BAND OF SNOW DEVELOPING ACROSS THE FCST AREA AND IT COULD BECOME HEAVY IN A VERY NARROW SWATH OVER S-CNTRL NEB. PROBABILITIES OF NO SNOW AT ALL ARE HIGHEST OVER N-CNTRL KS. THIS WILL BE A JET STREAK DRIVEN EVENT AS WIND/MASS ADJUSTMENTS RESULT IN WARM AIR ADVECTION AND FRONTOGENESIS /FGEN/ ON THE FRONT THAT MOVED THRU LAST NIGHT. CROSS SECTIONS INDICATE MID- LEVEL UPRIGHT INSTABILITY AND LIFT WILL BE STRONG IN THE DENDRITIC GROWTH ZONE /DGZ/. SEVERAL SCENARIOS ARE POSSIBLE TONIGHT AND WE WILL REALLY NOT KNOW WHICH ONE IS RIGHT UNTIL WE SEE THIS UNFOLD. THIS FCST IS FRAUGHT WITH UNCERTAINTY AND WE ARE ADMITTEDLY CONSERVATIVE ON SNOW AMOUNTS AND THE AERIAL EXTENT OF THE ADVISORY. BE PREPARED FOR ADJUSTMENTS LATER THIS EVENING AND TONIGHT THAT COULD RESULT IN DRAMATICALLY INCREASING OR DECREASING AMOUNTS FOR YOUR AREA. 09Z AND 15Z SREF PROBABILITIES FOR .25" ARE HIGHEST IN THE ADVISORY AREA. THE 15Z PROBS FOR .25" ARE HIGHER THAN 09Z AND THE 70% CHANCE OF .25" NOW EXTENDS E TO GRI. THE 19Z RAP SUPPORTS THIS. A CHECK OF THE 18Z NAM HAS .25" TO HASTINGS. SNOW TOTALS: GENERALLY 1-3" OVER S-CNTRL NEB. 2-3" FROM THE TRI-CITIES WESTWARD...AND 3-4" PRIMARILY OVER DAWSON COUNTY. THIS IS OUR BEST STAB USING A BLEND THE 00Z/06Z/12Z MULTI-MODEL QPF. THAT PRESENTS A PROBLEM. TOO MUCH AVERAGING SHOULD HIT THE SWATH OF SNOW CORRECTLY...BUT IT MAY BE TOO BROAD COMPARED TO REALITY AND FCST AMOUNTS MAY NOT BE HIGH ENOUGH. SNOW-LIQUID RATIOS: USED PRIMARILY 15:1 THRU THE EVENING AND CLOSE TO 20:1 AFTER MIDNIGHT. GIVEN THE STRENGTH OF THE LIFT IN THE DGZ... THESE RATIOS COULD ALSO BE CONSERVATIVE. POSSIBLE WEAKNESSES IN TONIGHT/S FCST: 1) WE MAY BE TOO BROAD WITH THE EDGES OF THE SNOW BAND...I.E. IT MAY BE MORE NARROW THAN DEPICTED. 2) DO WE HAVE THE HIGHEST POPS IN THE RIGHT LOCATION? THE HI-RES GEM HAS THE BAND BETWEEN I-80 AND THE KS BORDER. WE ARE IN THE I-80 CORRIDOR. 3) DEWPOINTS MAY BE TOO HIGH N OF I-80. DEWPOINTS IN THE SINGLE DIGITS ARE AS CLOSE AS O`NEILL. ADVECTION OF THIS VERY DRY AIR WILL PLAY A ROLE IN LIMITING THE NRN EXTENT OF THE BAND. 4) ARE AMOUNTS HIGH ENOUGH? WOULD NOT BE SURPRISED TO SEE A NARROW STRIP OF WARNING LEVEL SNOW /6-8"/ SOMEWHERE GIVEN THE RATIOS WE ARE LIKELY TO SEE. UNCERTAINTY: PLEASE KEEP IN MIND THAT THERE ARE SOME AREAS THAT HAVE SNOW IN THE FCST...BUT WILL SEE NO SNOW AT ALL. THIS ESPECIALLY APPLIES IF THE FCST PROBABILITY OF SNOW AT YOUR LOCATION IS 40% OR BELOW. THERE WILL BE A SHARP CUT-OFF ON THE NRN AND SRN FRINGES OF THIS BAND. THE SMALL SCALE NATURE OF THIS BAND IS PROBLEMATIC FOR PINNING DOWN DETAILS...BUT THIS COULD END UP A WARNING LEVEL EVENT FOR SOME COUNTIES. LOW TEMPS WERE FROM CONSENSUS OF 2M TEMPS WHICH RAISED TEMPS SEVERAL DEGREES. SUN: FGEN LIFTS N AND MID-LEVELS DRY OUT WITH STABILITY RETURNING. PATCHES OF LIGHT SNOW WILL LINGER THRU MID-MORNING...BUT THE ACCUMULATING SNOW WILL ESSENTIALLY BE OVER. PLENTY OF CLOUDS WILL REMAIN AND A FEW FLURRIES COULD REDEVELOP N AND W OF THE TRI- CITIES IN THE AFTERNOON. HIGH TEMPS HAVE A LOT OF CONTINUITY WITH THE 4 AM GID FCST. THE ONLY CHANGE WAS TO NUDGE TEMPS DOWN E OF HWY 281. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 407 PM CST SAT FEB 22 2014 THE BIG STORY WILL BE THE WELL BELOW NORMAL TEMPERATURES ALONG WITH SEVERAL CHANCES OF WINTRY PRECIPITATION. HIGH TEMPERATURES THROUGH THE PERIOD WILL GENERALLY AVERAGE 10 TO 15 DEGREES BELOW NORMAL. SUNDAY NIGHT AND MONDAY...MID LEVEL ISENTROPIC LIFT WILL RESULT IN SOME LOW END LIGHT SNOW CHANCES PRIMARILY ACROSS OUR NORTHERN ZONES WITH THE BETTER SNOW CHANCES WELL NORTH OF OUR FORECAST AREA ACROSS SOUTH DAKOTA. ALTHOUGH NOT IN THE OFFICIAL FORECAST AS OF RIGHT NOW...WILL ALSO NEED TO WATCH OUT FOR THE POSSIBILITY OF LIGHT FREEZING DRIZZLE ACROSS OUR NORTHERN AND WESTERN ZONES LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. ANY FREEZING DRIZZLE WOULD PRIMARILY BE CONFINED TO OUR WESTERN AND NORTHERN ZONES. THE 12Z GFS AND ECMWF DO NOT REALLY SHOW MUCH IN THE WAY OF FREEZING DRIZZLE POTENTIAL...BUT THE 12Z AND 18Z NAM DO INDICATE SOME POTENTIAL WITH LOW LEVEL SATURATION BENEATH A DRY MID LEVEL. THE NAM IS STILL A BIT OF AN OUTLIER AND THE POTENTIAL EVEN IN THE NAM IS SO MARGINAL THAT WE WILL CONTINUE TO LEAVE FREEZING DRIZZLE OUT OF THE FORECAST FOR NOW. ANY SNOW AMOUNTS WOULD LIKELY BE VERY LIGHT AND LESS THAN ONE HALF INCH. MONDAY NIGHT THROUGH TUESDAY...A SHORTWAVE TROUGH WILL TRACK SOUTHEAST OUT OF CANADA. ASSOCIATED UPPER JET DYNAMICS AND A PROGRESSIVE BAND OF MID LEVEL FRONTOGENESIS WILL LEAD TO ADDITIONAL CHANCES FOR LIGHT SNOW. NOT EXPECTING MUCH SNOW AT THIS TIME WITH MOST PLACES SEEING FLURRIES UP TO 1 INCH. COLDER AIR WILL FILTER IN ON TUESDAY WITH HIGHS STUCK IN THE 20S FOR MOST AREAS. WEDNESDAY THROUGH SATURDAY...WILL TRANSITION FROM A NORTHWESTERLY FLOW PATTERN TO A MORE ZONAL PATTERN...WITH PERHAPS EVEN THE DEVELOPMENT OF A TROUGH OVER THE WESTERN CONUS LATE IN THE PERIOD. OVERALL...THIS IS MORE LIKELY BE A DRY AND COOL PERIOD FOR OUR FORECAST AREA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 521 PM CST SAT FEB 22 2014 THE MAIN FORECAST ISSUE DURING THE TAF PERIOD IS THE DEVELOPMENT OF A FRONTOGENETIC BAND OF SNOWFALL OVERNIGHT AND INTO SUNDAY MORNING. SNOW HAS ALREADY DEVELOPED ACROSS WESTERN NEBRASKA AND THE SNOW SHOULD REACH KGRI AROUND 06Z WITH SNOW CONTINUING THROUGH THE NIGHT. SNOW ACCUMULATION FOR KGRI IS EXPECTED TO RANGE FROM 1 TO 3 INCHES. AS THE SNOW DEVELOPS/FALLS...CONDITIONS WILL DROP TO IFR OR POTENTIALLY LIFR. AS THE SNOW ENDS ON SUNDAY...VSBYS AND CIGS WILL IMPROVE BUT KEPT AFTN CIGS AT MVFR. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR NEZ060-061-072. KS...NONE. && $$ SHORT TERM...HALBLAUB LONG TERM...WESELY AVIATION...FAY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
300 PM CST FRI FEB 21 2014 .SHORT TERM...(THIS AFTERNOON THROUGH MONDAY) ISSUED AT 159 PM CST FRI FEB 21 2014 A BROAD CYCLONIC CIRCULATION IS INDICATED BY 12Z MODEL RUNS TO REMAIN IN PLACE ACROSS MUCH OF THE NORTHERN HALF OF THE NATION DURING THE PERIOD. THIS WILL RESULT IN TEMPERATURES TRENDING COLDER THROUGH THE PERIOD WITH A CHANCE OF SNOW COMING INTO THE AREA SUNDAY NIGHT INTO MONDAY. A RATHER SHARP THERMAL GRADIENT WAS IN PLACE ACROSS THE REGION AT 20Z WITH THE BOUNDARY STRETCHING FROM CENTRAL SOUTH DAKOTA THROUGH NORTHEAST IOWA AND NORTHERN ILLINOIS. A WEAK SURFACE WAVE IS FORECAST TO TRACK SOUTHEAST ALONG THIS GRADIENT TONIGHT AND BE OVER CENTRAL ILLINOIS BY SATURDAY MORNING. SHORT RANGE MODELS INDICATE SOME POTENTIAL FOR LIGHT SNOW NORTH OF THE WAVE LATE TONIGHT. QPF LOOKS A BIT OVERDONE BY THE RAP COMPARED TO THE LONG RANGE MODELS BUT HAVE INCLUDED A MENTION OF SCATTERED FLURRIES FOR NORTHEAST NEBRASKA INTO SOUTHWEST IOWA AS THIS FEATURE MOVES THROUGH TONIGHT. THE COLD FRONT ASSOCIATED WITH THE WEAK LOW SINKS SOUTH INTO THE SOUTHERN PLAINS AND LOWER OHIO VALLEY ON SATURDAY WITH COLD AIR SLOWLY MOVING SOUTH BEHIND THE FRONT. SOME LIGHT SNOW BREAKS OUT OVER THE WESTERN HIGH PLAINS SATURDAY AFTERNOON AS UPSLOPE FLOW DEVELOPS AND CONTINUES SATURDAY NIGHT WITH SOME SPREAD TO THE EAST INTO SOUTH CENTRAL NEBRASKA ASSOCIATED WITH WEAK ISENTROPIC FORCING. HAVE BACKED OFF A BIT ON POPS FOR SOUTHWEST PORTION OF THE FA FOR LATE SATURDAY NIGHT WITH SOME SLIGHT POPS INTO SUNDAY MORNING AS BETTER FORCING IS EXPECTED TO REMAIN FURTHER WEST. WEAK CYCLOGENESIS OCCURS OVER SOUTHEAST WYOMING ON SUNDAY AS AN UPPER WAVE BEGINS TO DROP INTO THE NORTHERN ROCKIES. SOUTHERLY LOW LEVEL FLOW DEVELOPS OVER THE CENTRAL PLAINS SUNDAY NIGHT IN RESPONSE TO THIS DEVELOPMENT WITH A STRONG BAROCLINIC ZONE OVER NORTHERN NEBRASKA BY MONDAY MORNING. A WIDESPREAD AREA OF SNOW IS LIKELY ALONG AND NORTH OF THIS BOUNDARY SUNDAY NIGHT INTO MONDAY MORNING. SNOW THEN SPREADS EAST ON MONDAY INTO NORTHERN IOWA AS THE UPPER WAVE TRACKS TOWARD THE UPPER MIDWEST WITH THE BETTER CHANCE OF SNOW EXPECTED NORTH OF INTERSTATE 80. MUCH COLDER AIR WILL ALSO SURGE INTO THE FA BEHIND THIS WAVE ON MONDAY. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 159 PM CST FRI FEB 21 2014 A COLD WINTER PATTERN WILL CONTINUE THROUGH THE PERIOD. ONE WEAK WAVE WILL CONTINUE TO DRIFT SOUTHWARD AT THE BEGINNING OF THE PERIOD...AND WITH H85 TEMPS WELL WITHIN THE DENDRITIC LAYER...COULD SEE LINGERING FLURRIES MONDAY NIGHT...BUT LITTLE OR NO ACCUMULATION. OTHERWISE...NORTHERLY FLOW WILL PERSIST TUESDAY AHEAD OF THE FIRST SURGE OF EVEN COLDER AIR THAT ARRIVES TUESDAY NIGHT AND LINGERS THROUGH WEDNESDAY...ALTHOUGH WESTERLY FLOW REDEVELOPS WEDNESDAY WHICH SHOULD KEEP TEMPS IN THE 20S INSTEAD OF THE TEENS. A SECONDARY SURGE OF COLDER TEMPS ARRIVES BY DAYBREAK THURSDAY AS SURFACE FLOW AGAIN RETURNS TO THE NORTH/NORTHEAST. THIS SHOULD KEEP TEMPS IN THE TEENS ON THURSDAY...BUT VERY LITTLE MOISTURE AVAILABLE SO NO CHANCE OF PRECIP. A WEAK RETURN FLOW TRIES TO DEVELOP ON FRIDAY...BUT TEMPS SHOULD REMAIN WELL BELOW NORMAL. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1230 PM CST FRI FEB 21 2014 VFR CONDITIONS THROUGH THE PERIOD. THERE WILL BE AN INCREASE IN MID CLOUDS THIS AFTERNOON WITH SOME BKN CIGS FL050-060 AND FL100-120 AND COULD BE SOME FLURRIES OR SPRINKLES. DUE TO ISOLATED NATURE OF PRECIPITATION WILL NOT MENTION IN TAFS.SURFACE WINDS WILL BECOME NORTHWEST AND VARY FROM 10 TO 18KTS SUSTAINED WITH SOME HIGHER GUSTS. AFTER 00Z...THE WINDS WILL SETTLE DOWN TO LESS THAN 10KTS. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT LONG TERM...DEWALD AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
835 PM EST SAT FEB 22 2014 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL BRING THE CHANCE FOR SNOW SHOWERS LATE TONIGHT...AND RAIN OR SNOW SHOWERS ON SUNDAY. COLDER AIR WILL RETURN FOR THE BEGINNING OF THE WORK WEEK WITH LAKE EFFECT SNOWS OVER CENTRAL NEW YORK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 8 PM UPDATE... THE CURRENT FCST IS IN FAIRLY GOOD SHAPE...SO ONLY RELATIVELY SMALL CHGS WERE MADE ATTM. RGNL RADAR IMAGERY SHOWS A NARROW BAND OF LGT PCPN (MAINLY -SN) EXTENDING FROM CNTRL IL-NRN IN-NRN OH-NW PA THIS EVE. THE LATEST RUC-13 AND HRRR OUTPUT APPEAR TO BE DOING A REASONABLY GOOD JOB HANDLING THE EVOLUTION OF THIS PCPN SO FAR. BOTH MODELS SUGGEST IT WILL STREAK INTO THE TWIN TIERS BY 06-09Z...THEN EXIT BY ARND 15Z SUN MRNG...UNDERNEATH DECENT 850-700 MB FGEN FORCING. THE MAIN FACTORS GOING AGAINST PCPN DVLPMT LOCALLY ARE DRY LOW-LVL AIR TO OVERCOME INITIALLY...AND ALSO NON-DESCRIPT JET DYNAMICS. OVERALL...WE FELT THE COURSE OF LEAST REGRET WAS TO BUMP POPS UP TO LIKELY VALUES WHERE WE HAVE SOME LGT SNOW ACCUMS MENTIONED LTR TNT INTO EARLY SUN (MOSTLY ACRS NY`S SRN TIER...WITH MAX AMTS GENERALLY 1" OR LESS). SHSN SHOULD DIMINISH QUICKLY TO FLRYS LTR SUN MRNG...THEN END ALTOGETHER BY MIDDAY. OTHWS...OUR TEMP/DEW PT GRIDS WERE MASSAGED SLIGHTLY THIS EVE...TO BEST REFLECT THE LATEST OBSERVATIONAL TRENDS. PREV DISC... 330 PM UPDATE... WEAK DISTURBANCE OVER THE OHIO VALLEY CREATING LIGHT PRECIPITATION OVER IL/IN WILL MOVE OUR WAY TONIGHT. I FOUND ONE OB TO THE WEST SHOWING 2 1/2SM IN SNOW. BASED ON THIS AND MODEL QPF...NOT EXPECTING MUCH MORE THAN A LIGHT DUSTING OF SNOW TONIGHT ESPECIALLY NEAR OR JUST NORTH OF THE NY/PA LINE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... 330 PM UPDATE... DISTURBANCE ABOVE MAY CONTINUE A FEW SNOW SHOWERS INTO MIDDAY SUNDAY BEFORE ENDING AS A SPRINKLE OR FLURRY. NOT EXPECTING MUCH. BIGGER STORY WILL BE MUCH COLDER AIR BUILDING IN SUNDAY NIGHT AND LASTING THROUGH TUESDAY. LAKE SNOWS LOOK LIKELY WITH A FLOW SETTLING IN BETWEEN 290 AND 270. ONE LIMITING FACTOR AT LEAST DURING THE DAY MAY DIURNAL EFFECTS. TAKE MONDAY AFTERNOON FOR EXAMPLE WITH NAM BUFKIT PROFILES SHOWING SURFACE BASED CAPE OF ABOVE 40 J/KG. BASED ON LOCAL RESEARCH, THESE VALUES COUPLED WITH LOW TO MODERATE SHEAR WOULD PROMOTE MORE OF A DIFFUSE BAND OR OPEN CELLULAR SNOW SHOWERS DURING THE AFTERNOON THAN A WELL DEFINED BAND. WITH THAT IN MIND TRIED TO SHOW THE BEST ACCUMS OF AT LEAST A FEW INCHES DURING THE NIGHTTIME AND EARLY PART OF THE DAY. COULD SEE NEEDING AN ADVISORY AT SOME POINT DOWN THE ROAD BUT A WARNING DOES NOT SEEM LIKELY...THUS AFTER COORDINATION WITH BUFFALO NO LAKE EFFECT WATCH AT THIS POINT. HIGHS GENERALLY IN THE 20S THROUGH TUESDAY. I DIDN`T TOUCH TUESDAYS HIGHS OF IN THE 20S. I DID NOTICE MODEL GUIDANCE, ALMOST ALL OF IT, IS IN THE TEENS. WILL BE INTERESTING TO SEE WHAT HAPPENS AS 925S SUPPORT OUR HIGHS OF 20S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MEDIUM RANGE MODELS CONTINUE TO SHOW EXCELLENT AGREEMENT THROUGH THE EXTENDED PERIOD BOTH ALOFT AND AT THE SFC. IN GENERAL THE PERIOD WILL BE VERY COLD WITH TEMPS RUNNING 15 TO 25 DEGREES BELOW SEASONAL NORMALS. TUESDAY NIGHT INTO WED, MODELS INDICATE SFC LOW PRES WELL OFF THE MID ATLANTIC COAST WITH THE GFS FURTHER OUT TO SEA THAN THE ECMWF. CURRENT MODEL TREND IS FOR AN EVEN MORE EASTERLY TRACK SO WILL CONTINUE WITH JUST CHC POPS THROUGH THIS PERIOD. REST OF FORECAST LOOKS PRIMARILY DRY WITH SCATTERED LAKE EFFECT SNOW SHOWERS AND FLURRIES EAST/SOUTHEAST OF LAKE ONTARIO. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... 630 PM UPDATE... SCT/BKN MID LEVEL CLOUDS WILL CONTINUE THIS EVENING. A WEAK DISTURBANCE WILL MOVE THROUGH PA OVERNIGHT WITH THE MODELS CONTINUING TO SUGGEST THE POTENTIAL FOR A NARROW BAND OF LIGHT SNOW OVER THE SOUTHERN TIER LATE TONIGHT AND EARLY SUNDAY MORNING. OVERALL CONFIDENCE WITH EXACT PLACEMENT AND TIMING OF SENSIBLE WEATHER IS LOW. POTENTIAL FOR MVFR CONDITIONS IN LIGHT SNOW AT KELM/KBGM/KITH LATE TONIGHT. ON SUNDAY LOW END VFR CONDITIONS ARE EXPECTED. GUSTY WEST WINDS WILL SUBSIDE QUICKLY. STILL GUSTING TO AROUND 25 KTS NOW AT SYR/RME WILL LAST UNTIL 02Z. TONIGHT SW TO W WINDS AT 5 TO 10 KTS. SUNDAY WEST WINDS AT 10 KTS. OUTLOOK... SUN NGT THROUGH TUE ATN...MVFR/IFR RESTRICTIONS IN LAKE EFFECT -SHSN CNTRL NY TERMINALS. TUE NGT THROUGH THU...RESTRICTIONS POSSIBLE IN SCATTERED SNOW SHWRS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...HEDEN NEAR TERM...HEDEN/MLJ SHORT TERM...HEDEN LONG TERM...RRM AVIATION...TAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 PM EST FRI FEB 21 2014 .SYNOPSIS...A STRONG COLD FRONT WILL PUSH SOUTH AND EAST OF THE AREA THIS EVENING. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST TONIGHT AND SATURDAY...THEN DRIFT EAST AND OFFSHORE ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM FRIDAY... QLCS CURRENTLY EXITING THE CWA AND WILL PLAN TO CANCEL TORNADO WATCH 23 FOR OUR COUNTIES WITH THE AFTERNOON PACKAGE. THE SYNOPTIC COLD FRONT WILL MAKING ITS WAY THROUGH THE WESTERN PIEDMONT RIGHT NOW AND WILL PUSH EAST THROUGH THE CWA BY AROUND 00Z. RH CROSS-SECTIONS SUGGEST THERE MAY BE JUST ENOUGH SHALLOW MOISTURE CONVERGENCE ALONE THE FRONT FOR A FEW ISOLATED SHOWERS. RECENT HRRR RUNS HAVEN`T BEEN EXTREMELY CONSISTENT WITH THE COVERAGE OF ANY ADDITIONAL SHOWERS...BUT WE WILL MAINTAIN JUST A SLIGHT CHANCE POP UNTIL HE FRONT CLEARS THE AREA. OTHERWISE...MUCH DRIER AIR WILL FILTER INTO THE AREA BEHIND THE FRONT ...WITH DEWPOINTS DROPPING INTO THE 20S. HIGH PRESSURE RIDGING IN FROM THE WEST WILL ALLOW WESTERN AREAS TO RADIATE THE BEST UNDER CLEAR SKIES...WITH LOWS DIPPING INTO THE MID 30S TO NEAR 40. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 PM FRIDAY... WELL SOUTH OF THE DEEP POLAR VORTEX OVER SOUTHEAST CANADA... THE CAROLINAS WILL LIE UNDER THE INFLUENCE OF BROAD WESTERLY CYCLONIC FLOW ALOFT. AT THE SURFACE...HIGH PRESSURE OF PACIFIC ORIGINS WILL BRIEFLY BUILD OVER THE SOUTHEAST US ON SATURDAY... SHIFTING OFFSHORE SATURDAY NIGHT WITH SOUTHERLY RETURN FLOW SUNDAY BEFORE A DRY SURFACE COLD FRONT MOVES SOUTHEASTWARD THROUGH THE AREA SUNDAY EVENING. THIS WILL TRANSLATE INTO TO DRY CONDITIONS WITH CONTINUED SPRING- LIKE TEMPERATURES INTO THE 60S ON SATURDAY...WITH SOME UPPER 60S TO LOWER 70S ON SUNDAY. LOWS SATURDAY NIGHT IN THE 40S...COOLING OFF INTO THE 30S BEHIND THE FRONT SUNDAY NIGHT. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 300 PM FRIDAY... DRY CONDITIONS WILL CONTINUE INTO MONDAY...ALBEIT WITH COOLER-MORE SEASONABLE TEMPERATURES AS A PROGRESSIVE NORTHERN STREAM HIGH OVER THE CENTRAL US BUILDS EASTWARD INTO THE AREA. TUESDAY THROUGH WEDNESDAY...AN EVEN STRONGER POLAR VORTEX DROPPING SOUTHEASTWARD INTO SOUTHERN CANADA WILL RESULT IN A SIGNIFICANT PATTERN CHANGE WITH A DEEP UPPER TROUGH FORECAST TO DEVELOP EAST OF THE ROCKIES. WHILE THE OVERALL PATTERN IS HIGHLY AGREED UPON...THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY THATS LARGELY OWED TO THE TIMING OF THE MID-LEVEL ENERGY EJECTING EASTWARD FROM THE CENTRAL ROCKIES...AND TO A LESSER EXTENT...WEAK S/W IMPULSES OUT AHEAD OF THE LEAD TROUGH THAT WILL EVENTUALLY RESULT IN SURFACE CYCLOGENESIS ALONG A BAROCLINIC FRONTAL ZONE EXTENDING FROM THE GULF OF MEXICO TO THE SE COAST. INCREASING RAIN CHANCES TUESDAY THROUGH WEDNESDAY...WITH POPS/QPF DEPENDING ON TRACK/LOCATION OF COASTAL LOW AND ALL LIQUID AT THIS TIME AS SIGNIFICANTLY COLDER AIR ARRIVES THURSDAY THROUGH FRIDAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 1250 PM FRIDAY... LINE OF CONVECTION MOVING THROUGH CENTRAL NC CURRENTLY EXTENDS FROM KIXA TO EAST OF KRDU TO KFAY. WITHIN THE LINE..CEILINGS ARE LIFR/IFR...WITH HEAVY RAIN AND LIFR VSBYS ARE TIMES. WINDS JUST AHEAD WITHIN STRONGER STORMS WILL GUST TO 30-40KT..MOSTLY FROM THE WEST-SOUTHWEST. THE LINE IS EXPECTED TO MOVE EAST OF I-95 WITHIN THE NEXT HOUR OR TWO AND BE CLEAR OF THE AREA BY 21Z. WEST OF THE LINE...SOME LIGHT RAIN IS STILL FALLING AND CEILINGS ARE MOSTLY MVFR OR VFR. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM HAS MOVED THROUGH KGSO AND KINT...WHERE WINDS FROM THE NORTHWEST GUSTED TO 30KT. THIS WILL BE POSSIBLE AT KRDU...KFAY AND KINT BY 20-22Z AS THE FRONT PUSHES EAST. SKIES WILL THEN CLEAR BEHIND THE FRONT AND VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE TAF PERIOD. OUTLOOK... A DRY COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY NIGHT...WITH ONLY A SMALL CHANCE OF SUB-VFR CONDITIONS. OTHERWISE... VFR CONDITIONS ARE EXPECTED THROUGH EARLY TUESDAY WHEN ANOTHER WEATHER SYSTEM IS EXPECTED TO IMPACT THE REGION. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...SMITH SHORT TERM..CBL LONG TERM...CBL AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
303 PM EST FRI FEB 21 2014 .SYNOPSIS...A STRONG COLD FRONT WILL PUSH SOUTH AND EAST OF THE AREA THIS EVENING. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST TONIGHT AND SATURDAY...THEN DRIFT EAST AND OFFSHORE ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM FRIDAY... QLCS CURRENTLY EXITING THE CWA AND WILL PLAN TO CANCEL TORNADO WATCH 23 FOR OUR COUNTIES WITH THE AFTERNOON PACKAGE. THE SYNOPTIC COLD FRONT WILL MAKING ITS WAY THROUGH THE WESTERN PIEDMONT RIGHT NOW AND WILL PUSH EAST THROUGH THE CWA BY AROUND 00Z. RH CROSS-SECTIONS SUGGEST THERE MAY BE JUST ENOUGH SHALLOW MOISTURE CONVERGENCE ALONE THE FRONT FOR A FEW ISOLATED SHOWERS. RECENT HRRR RUNS HAVEN`T BEEN EXTREMELY CONSISTENT WITH THE COVERAGE OF ANY ADDITIONAL SHOWERS...BUT WE WILL MAINTAIN JUST A SLIGHT CHANCE POP UNTIL HE FRONT CLEARS THE AREA. OTHERWISE...MUCH DRIER AIR WILL FILTER INTO THE AREA BEHIND THE FRONT ...WITH DEWPOINTS DROPPING INTO THE 20S. HIGH PRESSURE RIDGING IN FROM THE WEST WILL ALLOW WESTERN AREAS TO RADIATE THE BEST UNDER CLEAR SKIES...WITH LOWS DIPPING INTO THE MID 30S TO NEAR 40. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 304 AM FRIDAY... HIGH PRESSURE WILL BUILD ACROSS THE AREA IN THE WAKE OF THE FRONT... AND A MUCH DRIER AIRMASS WILL BE IN PLACE ACROSS THE AREA BRINGING MOSTLY SUNNY SKIES. INITIAL COLD ADVECTION EARLY SATURDAY WILL BECOME NEUTRAL... AS UPPER LEVEL FLOW REMAINS PRIMARILY SOUTHWESTERLY DURING THE DAY SATURDAY... AND TEMPERATURES WILL REMAIN A FEW DEGREES ABOVE NORMAL. HIGH PRESSURE WILL MOVE OFFSHORE SUNDAY... WARMER SOUTHERLY FLOW... AND INCREASING LOW LEVEL THICKNESSES WILL RESULT IN TEMPERATURES SLIGHTLY WARMER THAN SATURDAY. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 305 AM FRIDAY... A DRY COLD FRONT WILL MOVE THROUGH THE AREA MONDAY MORNING... BRINGING TEMPERATURES MUCH CLOSER TO NORMAL FOR THE BEGINNING OF THE WEEK. STRONG SIGNAL FOR RIDGING ACROSS THE WESTERN US... WITH BROAD TROUGHING DEVELOPING OVER THE EAST COAST THROUGH THE WEEK. THIS WILL BRING TEMPS BACK BELOW NORMAL. WAVES MOVING THROUGH THE NORTHWEST FLOW GENERALLY STAY NORTH OF OUR AREA THROUGH THIS PERIOD... WITH THE EXCEPTION OF WEDNESDAY WHEN A AN IMPULSE AND ASSOCIATED COLD FRONT ARE PROGGED TO MOVE THROUGH THE AREA... AND THE POTENTIAL FOR A LOW PRESSURE SYSTEM TO DEVELOP OFF THE CAROLINA COAST... BRINGING THE BEST CHANCE FOR PRECIPITATION DURING THIS PERIOD. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 1250 PM FRIDAY... LINE OF CONVECTION MOVING THROUGH CENTRAL NC CURRENTLY EXTENDS FROM KIXA TO EAST OF KRDU TO KFAY. WITHIN THE LINE..CEILINGS ARE LIFR/IFR...WITH HEAVY RAIN AND LIFR VSBYS ARE TIMES. WINDS JUST AHEAD WITHIN STRONGER STORMS WILL GUST TO 30-40KT..MOSTLY FROM THE WEST-SOUTHWEST. THE LINE IS EXPECTED TO MOVE EAST OF I-95 WITHIN THE NEXT HOUR OR TWO AND BE CLEAR OF THE AREA BY 21Z. WEST OF THE LINE...SOME LIGHT RAIN IS STILL FALLING AND CEILINGS ARE MOSTLY MVFR OR VFR. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM HAS MOVED THROUGH KGSO AND KINT...WHERE WINDS FROM THE NORTHWEST GUSTED TO 30KT. THIS WILL BE POSSIBLE AT KRDU...KFAY AND KINT BY 20-22Z AS THE FRONT PUSHES EAST. SKIES WILL THEN CLEAR BEHIND THE FRONT AND VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE TAF PERIOD. OUTLOOK... A DRY COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY NIGHT...WITH ONLY A SMALL CHANCE OF SUB-VFR CONDITIONS. OTHERWISE... VFR CONDITIONS ARE EXPECTED THROUGH EARLY TUESDAY WHEN ANOTHER WEATHER SYSTEM IS EXPECTED TO IMPACT THE REGION. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...SMITH SHORT TERM..SEC LONG TERM...SEC AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NORMAN OK
1100 AM CST FRI FEB 21 2014 .AVIATION... GUSTY SOUTH WINDS WILL CONTINUE THIS AFTERNOON BEFORE DYING DOWN AFTER SUNSET. OTHERWISE...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 1033 AM CST FRI FEB 21 2014/ DISCUSSION... WINDS AND TEMPERATURES ARE INCREASING RAPIDLY THIS MORNING AS THE SHALLOW SURFACE INVERSION MIXES OUT. IT APPEARS THAT WE WILL START SEEING RED FLAG WARNING CRITERIA BEING MET AROUND NOON...AS PLANNED. ALL FEATURES OF THE FORECAST APPEAR TO BE IN GOOD SHAPE AT THIS TIME...AND NO CHANGES ARE PLANNED FOR THIS MORNING. PREV DISCUSSION... /ISSUED 527 AM CST FRI FEB 21 2014/ DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. SOUTH TO SOUTHWEST WINDS WILL INCREASE AND BECOME GUSTY AT ALL SITES BY 17Z. THESE WINDS WILL SUBSIDE AROUND 00Z. MBS PREV DISCUSSION... /ISSUED 404 AM CST FRI FEB 21 2014/ DISCUSSION... THE MAIN CONCERN IS CRITICAL FIRE WEATHER CONDITIONS TODAY. MOSTLY TO PARTLY SUNNY SKIES AND MILDER WEATHER WILL OCCUR TODAY. WINDS WILL BE WEAKER THAN YESTERDAY...THOUGH BREEZY. PREFERRED THE WARMER SIDE OF GUIDANCE HIGHS TODAY WITH A GOOD AMOUNT OF SUN AND DRY GROUND...GENERALLY FROM THE LOWER 60S NEAR THE KANSAS OKLAHOMA STATE LINE TO THE MID 70S IN FAR WESTERN NORTH TEXAS. WENT ABOVE MODEL GUIDANCE WIND SPEEDS AND BELOW MOST MODEL GUIDANCE DEWPOINTS. A FEW GUSTS MAY APPROACH 40 MPH IN WESTERN OKLAHOMA AROUND MIDDAY TODAY. THE LOWER SURFACE DEWPOINTS DEPICTED BY LATEST HRRR RUNS WERE USED TODAY AS OTHER MODELS SEEM TO BE OVERESTIMATING THE AMOUNT OF LOW LEVEL MOISTURE. DRY AND MILD WEATHER WILL CONTINUE INTO SATURDAY UNDER MOSTLY TO PARTLY SUNNY. LESS WIND IS FORECAST COMPARED TO TODAY. SATURDAY NIGHT INTO SUNDAY...LOW LEVEL MOISTURE WILL INCREASE ACROSS THE AREA. ADDED PATCHY FOG MENTION NEAR AND SOUTHEAST OF A DEVELOPING SURFACE TROUGH/COLD FRONT...ROUGHLY NEAR AND SOUTHEAST OF I-44. THINK MOISTURE WILL BE TOO SHALLOW FOR ANY MEASURABLE RAINFALL OF 0.01 INCH OR MORE. COOLER TEMPERATURES WILL RESULT ON SUNDAY AS THE COLD FRONT SURGES SOUTH. MONDAY THROUGH TUESDAY...KEPT LOW SHOWER/STORM CHANCES OVER SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS AS ISENTROPIC LIFT COMBINED WITH SOME ELEVATED INSTABILITY MAY ALLOW FOR DEVELOPMENT OF CONVECTIVE LIQUID PRECIPITATION JUST NORTH OF A WARM FRONT. CONFIDENCE WITH THIS SYSTEM REMAINS LOW. HIGHS WILL BE BELOW AVERAGE. WEDNESDAY AND THURSDAY...BELOW AVERAGE TEMPERATURES AND DRY WEATHER ARE FORECAST. DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE PREVIOUS FORECAST. MBS FIRE WEATHER... UPGRADED THE ENTIRE FIRE WEATHER WATCH TO A RED FLAG WARNING AND INCLUDED MANY COUNTIES IN NORTHERN OKLAHOMA AS THESE LOCATIONS WILL BE NEAR 65 DEGREES TODAY. STARTED THE RED FLAG WARNING AT 10 AM TODAY AS POOR HUMIDITY RECOVERY EARLY THIS MORNING WILL ALLOW FOR RED FLAG CONDITIONS TO DEVELOP FASTER THAN PREVIOUSLY FORECAST. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 39 66 42 52 / 0 0 0 10 HOBART OK 38 70 41 52 / 0 0 0 0 WICHITA FALLS TX 43 76 47 61 / 0 0 0 0 GAGE OK 21 63 34 46 / 0 0 0 0 PONCA CITY OK 35 60 36 47 / 0 0 10 10 DURANT OK 44 70 52 61 / 0 0 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR OKZ005>030- 033>040-044-045. TX...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR TXZ083>090. && $$ 23/84/14
AREA FORECAST DISCUSSION
NWS NORMAN OK
1033 AM CST FRI FEB 21 2014 .DISCUSSION... WINDS AND TEMPERATURES ARE INCREASING RAPIDLY THIS MORNING AS THE SHALLOW SURFACE INVERSION MIXES OUT. IT APPEARS THAT WE WILL START SEEING RED FLAG WARNING CRITERIA BEING MET AROUND NOON...AS PLANNED. ALL FEATURES OF THE FORECAST APPEAR TO BE IN GOOD SHAPE AT THIS TIME...AND NO CHANGES ARE PLANNED FOR THIS MORNING. && .PREV DISCUSSION... /ISSUED 527 AM CST FRI FEB 21 2014/ DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. SOUTH TO SOUTHWEST WINDS WILL INCREASE AND BECOME GUSTY AT ALL SITES BY 17Z. THESE WINDS WILL SUBSIDE AROUND 00Z. MBS PREV DISCUSSION... /ISSUED 404 AM CST FRI FEB 21 2014/ DISCUSSION... THE MAIN CONCERN IS CRITICAL FIRE WEATHER CONDITIONS TODAY. MOSTLY TO PARTLY SUNNY SKIES AND MILDER WEATHER WILL OCCUR TODAY. WINDS WILL BE WEAKER THAN YESTERDAY...THOUGH BREEZY. PREFERRED THE WARMER SIDE OF GUIDANCE HIGHS TODAY WITH A GOOD AMOUNT OF SUN AND DRY GROUND...GENERALLY FROM THE LOWER 60S NEAR THE KANSAS OKLAHOMA STATE LINE TO THE MID 70S IN FAR WESTERN NORTH TEXAS. WENT ABOVE MODEL GUIDANCE WIND SPEEDS AND BELOW MOST MODEL GUIDANCE DEWPOINTS. A FEW GUSTS MAY APPROACH 40 MPH IN WESTERN OKLAHOMA AROUND MIDDAY TODAY. THE LOWER SURFACE DEWPOINTS DEPICTED BY LATEST HRRR RUNS WERE USED TODAY AS OTHER MODELS SEEM TO BE OVERESTIMATING THE AMOUNT OF LOW LEVEL MOISTURE. DRY AND MILD WEATHER WILL CONTINUE INTO SATURDAY UNDER MOSTLY TO PARTLY SUNNY. LESS WIND IS FORECAST COMPARED TO TODAY. SATURDAY NIGHT INTO SUNDAY...LOW LEVEL MOISTURE WILL INCREASE ACROSS THE AREA. ADDED PATCHY FOG MENTION NEAR AND SOUTHEAST OF A DEVELOPING SURFACE TROUGH/COLD FRONT...ROUGHLY NEAR AND SOUTHEAST OF I-44. THINK MOISTURE WILL BE TOO SHALLOW FOR ANY MEASURABLE RAINFALL OF 0.01 INCH OR MORE. COOLER TEMPERATURES WILL RESULT ON SUNDAY AS THE COLD FRONT SURGES SOUTH. MONDAY THROUGH TUESDAY...KEPT LOW SHOWER/STORM CHANCES OVER SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS AS ISENTROPIC LIFT COMBINED WITH SOME ELEVATED INSTABILITY MAY ALLOW FOR DEVELOPMENT OF CONVECTIVE LIQUID PRECIPITATION JUST NORTH OF A WARM FRONT. CONFIDENCE WITH THIS SYSTEM REMAINS LOW. HIGHS WILL BE BELOW AVERAGE. WEDNESDAY AND THURSDAY...BELOW AVERAGE TEMPERATURES AND DRY WEATHER ARE FORECAST. DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE PREVIOUS FORECAST. MBS FIRE WEATHER... UPGRADED THE ENTIRE FIRE WEATHER WATCH TO A RED FLAG WARNING AND INCLUDED MANY COUNTIES IN NORTHERN OKLAHOMA AS THESE LOCATIONS WILL BE NEAR 65 DEGREES TODAY. STARTED THE RED FLAG WARNING AT 10 AM TODAY AS POOR HUMIDITY RECOVERY EARLY THIS MORNING WILL ALLOW FOR RED FLAG CONDITIONS TO DEVELOP FASTER THAN PREVIOUSLY FORECAST. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 66 39 66 42 / 0 0 0 0 HOBART OK 68 38 70 41 / 0 0 0 0 WICHITA FALLS TX 71 43 76 47 / 0 0 0 0 GAGE OK 64 21 63 34 / 0 0 0 0 PONCA CITY OK 63 35 60 36 / 0 0 0 10 DURANT OK 65 44 70 52 / 0 0 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR OKZ005>030- 033>040-044-045. TX...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR TXZ083>090. && $$ 23/84
AREA FORECAST DISCUSSION
NWS NORMAN OK
527 AM CST FRI FEB 21 2014 .DISCUSSION... AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW. && .AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. SOUTH TO SOUTHWEST WINDS WILL INCREASE AND BECOME GUSTY AT ALL SITES BY 17Z. THESE WINDS WILL SUBSIDE AROUND 00Z. MBS && .PREV DISCUSSION... /ISSUED 404 AM CST FRI FEB 21 2014/ DISCUSSION... THE MAIN CONCERN IS CRITICAL FIRE WEATHER CONDITIONS TODAY. MOSTLY TO PARTLY SUNNY SKIES AND MILDER WEATHER WILL OCCUR TODAY. WINDS WILL BE WEAKER THAN YESTERDAY...THOUGH BREEZY. PREFERRED THE WARMER SIDE OF GUIDANCE HIGHS TODAY WITH A GOOD AMOUNT OF SUN AND DRY GROUND...GENERALLY FROM THE LOWER 60S NEAR THE KANSAS OKLAHOMA STATE LINE TO THE MID 70S IN FAR WESTERN NORTH TEXAS. WENT ABOVE MODEL GUIDANCE WIND SPEEDS AND BELOW MOST MODEL GUIDANCE DEWPOINTS. A FEW GUSTS MAY APPROACH 40 MPH IN WESTERN OKLAHOMA AROUND MIDDAY TODAY. THE LOWER SURFACE DEWPOINTS DEPICTED BY LATEST HRRR RUNS WERE USED TODAY AS OTHER MODELS SEEM TO BE OVERESTIMATING THE AMOUNT OF LOW LEVEL MOISTURE. DRY AND MILD WEATHER WILL CONTINUE INTO SATURDAY UNDER MOSTLY TO PARTLY SUNNY. LESS WIND IS FORECAST COMPARED TO TODAY. SATURDAY NIGHT INTO SUNDAY...LOW LEVEL MOISTURE WILL INCREASE ACROSS THE AREA. ADDED PATCHY FOG MENTION NEAR AND SOUTHEAST OF A DEVELOPING SURFACE TROUGH/COLD FRONT...ROUGHLY NEAR AND SOUTHEAST OF I-44. THINK MOISTURE WILL BE TOO SHALLOW FOR ANY MEASURABLE RAINFALL OF 0.01 INCH OR MORE. COOLER TEMPERATURES WILL RESULT ON SUNDAY AS THE COLD FRONT SURGES SOUTH. MONDAY THROUGH TUESDAY...KEPT LOW SHOWER/STORM CHANCES OVER SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS AS ISENTROPIC LIFT COMBINED WITH SOME ELEVATED INSTABILITY MAY ALLOW FOR DEVELOPMENT OF CONVECTIVE LIQUID PRECIPITATION JUST NORTH OF A WARM FRONT. CONFIDENCE WITH THIS SYSTEM REMAINS LOW. HIGHS WILL BE BELOW AVERAGE. WEDNESDAY AND THURSDAY...BELOW AVERAGE TEMPERATURES AND DRY WEATHER ARE FORECAST. DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE PREVIOUS FORECAST. MBS FIRE WEATHER... UPGRADED THE ENTIRE FIRE WEATHER WATCH TO A RED FLAG WARNING AND INCLUDED MANY COUNTIES IN NORTHERN OKLAHOMA AS THESE LOCATIONS WILL BE NEAR 65 DEGREES TODAY. STARTED THE RED FLAG WARNING AT 10 AM TODAY AS POOR HUMIDITY RECOVERY EARLY THIS MORNING WILL ALLOW FOR RED FLAG CONDITIONS TO DEVELOP FASTER THAN PREVIOUSLY FORECAST. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 66 39 66 42 / 0 0 0 0 HOBART OK 68 38 70 41 / 0 0 0 0 WICHITA FALLS TX 71 43 76 47 / 0 0 0 0 GAGE OK 64 21 63 34 / 0 0 0 0 PONCA CITY OK 63 35 60 36 / 0 0 0 10 DURANT OK 65 44 70 52 / 0 0 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING FOR OKZ005>030-033>040-044-045. TX...RED FLAG WARNING FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING FOR TXZ083>090. && $$ 03/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
404 AM CST FRI FEB 21 2014 .DISCUSSION... THE MAIN CONCERN IS CRITICAL FIRE WEATHER CONDITIONS TODAY. MOSTLY TO PARTLY SUNNY SKIES AND MILDER WEATHER WILL OCCUR TODAY. WINDS WILL BE WEAKER THAN YESTERDAY...THOUGH BREEZY. PREFERRED THE WARMER SIDE OF GUIDANCE HIGHS TODAY WITH A GOOD AMOUNT OF SUN AND DRY GROUND...GENERALLY FROM THE LOWER 60S NEAR THE KANSAS OKLAHOMA STATE LINE TO THE MID 70S IN FAR WESTERN NORTH TEXAS. WENT ABOVE MODEL GUIDANCE WIND SPEEDS AND BELOW MOST MODEL GUIDANCE DEWPOINTS. A FEW GUSTS MAY APPROACH 40 MPH IN WESTERN OKLAHOMA AROUND MIDDAY TODAY. THE LOWER SURFACE DEWPOINTS DEPICTED BY LATEST HRRR RUNS WERE USED TODAY AS OTHER MODELS SEEM TO BE OVERESTIMATING THE AMOUNT OF LOW LEVEL MOISTURE. DRY AND MILD WEATHER WILL CONTINUE INTO SATURDAY UNDER MOSTLY TO PARTLY SUNNY. LESS WIND IS FORECAST COMPARED TO TODAY. SATURDAY NIGHT INTO SUNDAY...LOW LEVEL MOISTURE WILL INCREASE ACROSS THE AREA. ADDED PATCHY FOG MENTION NEAR AND SOUTHEAST OF A DEVELOPING SURFACE TROUGH/COLD FRONT...ROUGHLY NEAR AND SOUTHEAST OF I-44. THINK MOISTURE WILL BE TOO SHALLOW FOR ANY MEASURABLE RAINFALL OF 0.01 INCH OR MORE. COOLER TEMPERATURES WILL RESULT ON SUNDAY AS THE COLD FRONT SURGES SOUTH. MONDAY THROUGH TUESDAY...KEPT LOW SHOWER/STORM CHANCES OVER SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS AS ISENTROPIC LIFT COMBINED WITH SOME ELEVATED INSTABILITY MAY ALLOW FOR DEVELOPMENT OF CONVECTIVE LIQUID PRECIPITATION JUST NORTH OF A WARM FRONT. CONFIDENCE WITH THIS SYSTEM REMAINS LOW. HIGHS WILL BE BELOW AVERAGE. WEDNESDAY AND THURSDAY...BELOW AVERAGE TEMPERATURES AND DRY WEATHER ARE FORECAST. DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE PREVIOUS FORECAST. MBS && .FIRE WEATHER... UPGRADED THE ENTIRE FIRE WEATHER WATCH TO A RED FLAG WARNING AND INCLUDED MANY COUNTIES IN NORTHERN OKLAHOMA AS THESE LOCATIONS WILL BE NEAR 65 DEGREES TODAY. STARTED THE RED FLAG WARNING AT 10 AM TODAY AS POOR HUMIDITY RECOVERY EARLY THIS MORNING WILL ALLOW FOR RED FLAG CONDITIONS TO DEVELOP FASTER THAN PREVIOUSLY FORECAST. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 66 39 66 42 / 0 0 0 0 HOBART OK 68 38 70 41 / 0 0 0 0 WICHITA FALLS TX 71 43 76 47 / 0 0 0 0 GAGE OK 64 21 63 34 / 0 0 0 0 PONCA CITY OK 63 35 60 36 / 0 0 0 10 DURANT OK 65 44 70 52 / 0 0 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING FOR OKZ005>030-033>040-044-045. TX...RED FLAG WARNING FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING FOR TXZ083>090. && $$ 03/17
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
244 PM CST FRI FEB 21 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 244 PM CST FRI FEB 21 2014 MAIN FORECASTS CONCERNS ARE ON SNOW CHANCES MONDAY NIGHT. FOCUS THEN TURNS TO BITTERLY COLD TEMPERATURES LATE NEXT WEEK. LATEST SURFACE OBSERVATIONS AND REPORTS ACROSS THE AREA INDICATED AREAS OF BLOWING AND DRIFTING SNOW...LEADING TO HAZARDOUS TRAVEL CONDITIONS. THE WORST OF THE BLOWING AND DRIFTING SNOW WAS OCCURRING WEST OF THE MISSISSIPPI RIVER. CONDITIONS ARE EXPECTED TO IMPROVE LATE THIS AFTERNOON INTO EARLY THIS EVENING. THE POTENT LOW PRESSURE SYSTEM RESPONSIBLE FOR THE STRONG WEST/NORTHWEST WINDS WAS CENTERED OVER NORTH CENTRAL LAKE SUPERIOR. THE LOW WILL LIFT NORTHEAST OF THE REGION TONIGHT AS HIGH PRESSURE EDGES IN FROM THE NORTHERN PLAINS. A PERSISTENT PRESSURE GRADIENT WILL REMAIN IN PLACE OVER THE UPPER MISSISSIPPI RIVER VALLEY TONIGHT THROUGH SATURDAY CREATING WEST WINDS OF 10 TO 17 MPH. THESE WINDS WILL MAKE IT FEEL CHILLY ON SATURDAY WITH WIND CHILLS IN THE SINGLE DIGITS TO SINGLE DIGITS BELOW ZERO. PLAN ON HIGH TEMPERATURES RANGING FROM THE MID TEENS TO LOWER 20S. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 244 PM CST FRI FEB 21 2014 A CHILLY NIGHT IN STORE FOR THE AREA SATURDAY NIGHT WITH LOWS RANGING ROM THE SINGLE DIGITS BELOW ZERO OVER SOUTHEAST MINNESOTA THROUGH NORTH CENTRAL WISCONSIN TO THE SINGLE DIGITS ABOVE ZERO OVER FAR SOUTHWEST WISCONSIN INTO NORTHEAST IOWA. WIND CHILL VALUES ARE EXPECTED TO DIP INTO THE 20 TO 27 BELOW RANGE LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING OVER NORTH CENTRAL WISCONSIN. ELSEWHERE...PLAN ON WIND CHILLS FALLING INTO THE TEENS BELOW ZERO. DRY...QUIET...AND CHILLY CONDITIONS WILL CONTINUE THROUGH SUNDAY WITH HIGHS MAINLY IN THE TEENS AND LOWS IN THE SINGLE DIGITS BELOW ZERO. A SHORTWAVE TROUGH IS EXPECTED TO DROP INTO THE REGION FROM THE NORTHERN PLAINS LATE MONDAY AFTERNOON INTO MONDAY NIGHT PRODUCING LIGHT SNOW ACROSS AREA. AT THIS TIME...THE HIGHEST CHANCES FOR SNOW LOOK TO BE SOUTH AND WEST OF THE INTERSTATE 94 CORRIDOR. LATEST THINKING IS THAT SNOW ACCUMULATIONS SHOULD RANGE FROM 1 TO 3 INCHES...WITH THE HIGHER ACCUMULATIONS OCCURRING OVER NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN...BUT THIS DEPENDS ON THE EXACT STORM TRACK. GIVEN THE CONSISTENT SIGNAL FOR SNOW OVER THESE AREAS HAVE DECIDED TO INCREASE PRECIPITATION CHANCES. A BITTERLY COLD ARCTIC AIRMASS MOVES BACK INTO THE REGION LATE TUESDAY INTO WEDNESDAY WITH 850 MB TEMPERATURES PLUMMETING INTO THE -22 TO -25 C RANGE. WIND CHILL VALUES OF 20 TO 25 BELOW ZERO LOOK LIKELY TUESDAY NIGHT INTO WEDNESDAY MORNING AND A WIND CHILL ADVISORY WILL LIKELY BE NEEDED. THE COLDEST TEMPERATURES ARE EXPECTED TO SETTLE IN WEDNESDAY INTO THURSDAY WHEN LOWS LOOK TO FALL INTO THE TEENS TO AROUND 20 BELOW ZERO. WIND CHILL HEADLINES APPEAR LIKELY WEDNESDAY NIGHT AND AGAIN THURSDAY NIGHT...WHEN WIND CHILL VALUES OF 20 TO 30 BELOW ZERO ARE EXPECTED. THURSDAY NIGHT LOOKS TO HAVE THE COLDEST AIR TEMPERATURES WHEN LOWS WILL FALL INTO THE TEENS TO AROUND 20 BELOW ZERO. 850 MB TEMPERATURE STANDARDIZED ANOMALIES OF -2.0 TO -2.5 MOVE INTO THE REGION LATE THURSDAY NIGHT INTO FRIDAY PUTTING US IN NEAR RECORD TERRITORY FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1150 AM CST FRI FEB 21 2014 STRONG WEST WINDS AT 20 TO 30 WITH GUSTS TO 35 WILL PERSIST THROUGH MUCH OF THE AFTERNOON HOURS...PER LATEST RAP SOUNDINGS. KRST/KLSE ON CLEARING EDGE OF THE CLOUDS...VIA SFC OBS AND SATELLITE IMAGERY. OBS MAY POINT TO SOME CIGS FROM BLOWING SNOW. GOING TO KEEP VSBY RESTRICTIONS AT KRST THROUGH THE AFTERNOON. VFR CONDITIONS SHOULD BE THE RULE TONIGHT INTO SATURDAY WITH SKC SKIES AND WINDS TAPERING OFF INTO THE 10 TO 15 KT RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ017- 029-032>034-041>044-053>055-061. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ079- 086>088-094>096. IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ008>011-018-019-029-030. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 AM CST FRI FEB 21 2014 .UPDATED... 1150 AM CST FRI FEB 21 2014 MANY ROAD CLOSURES CONTINUE ACROSS SOUTHEAST MN AND NORTHEAST IA...WITH A TOW BAN IN EFFECT FOR SOME LOCATIONS. WINDS ARE GOING TO STAY STRONG AND GUSTY THROUGH THE AFTERNOON...WITH ANY SUNSHINE ONLY HELPING MIX DOWN THE STRONG NEAR SFC WINDS. WILL LET THE WARNINGS EXPIRE...BUT REPLACE WITH A WINTER WEATHER ADV FOR BLOWING/DRIFTING SNOW FOR THE ENTIRE FORECAST AREA THROUGH 00Z. CONDITIONS STILL WARRANT IT. .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 214 AM CST FRI FEB 21 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED NORTHWEST FLOW FROM ALASKA DOWN INTO THE MID-MISSISSIPPI RIVER VALLEY AND A DEEP UPPER LOW OVER NORTHERN WI. UNDERNEATH THE UPPER LOW WAS A 978 MB SURFACE LOW NEAR RHINELANDER. A VERY TIGHT PRESSURE GRADIENT SOUTHWEST OF THE LOW WAS SUPPORTING SURFACE WINDS OF 25 TO 35 MPH WITH GUSTS UP TO 55 MPH. THE COLD CONVEYOR BELT WRAPPING AROUND THE NEARLY VERTICALLY STACKED LOW WAS STILL BRINGING SNOW TO THE FORECAST AREA...HEAVIEST OVER NORTH CENTRAL WI. EARLIER LAST EVENING THE STRONG WINDS WERE NOT REDUCING VISIBILITIES THAT MUCH IN SOUTHEAST MN/NORTHEAST IA PER ASOS/AWOS OBSERVATIONS...DUE TO THE WET NATURE OF THE SNOW. HOWEVER...CALLS TO COUNTY SHERIFFS IN THE SAME AREA WERE REPORTING WHITEOUTS WITH SOME ROADS CLOSED...SUGGESTING ASOS/AWOS OBSERVATIONS WERE NOT FULLY REPRESENTATIVE. IN ADDITION...POWER OUTAGES WERE A MAJOR ISSUE WITH THE WEIGHT OF THE WET SNOW ON TREES/POWER LINES AND WINDS. NOW THE WINDS HAVE ADVECTED COLDER AIR INTO THE FORECAST AREA AS NOTED BY TEMPERATURES IN THE TEENS TO LOW 20S. THE COLDER AIR HAS ALLOWED THE SNOW TO BECOME DRIER...MORE ABLE TO BLOW. THE NEARLY VERTICALLY STACKED LOW WILL CONTINUE LIFTING NORTHEASTWARD OVER THE NEXT 24 HOURS...REACHING NORTHERN ONTARIO THIS EVENING. AS THE LOW PULLS AWAY...THE WINDS WILL GRADUALLY RELAX...DROPPING FROM 20 TO 35 MPH WITH HIGHER GUSTS DURING THE MORNING TO 10 TO 25 MPH BY 00Z. FURTHER DIMINISHING OF THE WINDS ARE EXPECTED TONIGHT. IN TERMS OF THE COLD CONVEYOR BELT OF SNOW...GOOD AGREEMENT EXISTS THAT THE SNOW SHOULD EXIT MOST LOCATIONS WEST OF THE MISSISSIPPI RIVER BY 12Z...LOCATIONS SOUTHWEST OF I-94 BY 18Z...AND THE CHIMNEY AREA BY 00Z. MUCH OF THE SNOW SHOULD BE LIGHT WITH THE SYSTEM OCCLUDED AND MOVING AWAY. JUXTAPOSITION OF THE WINDS AND SNOW SUGGESTS CONTINUATION OF HAZARDS OVER THE NORTHWEST HALF OF THE FORECAST AREA. CONTEMPLATED RIGHT NOW CANCELING SOME OF THE WINTER WEATHER ADVISORY...BUT HAVE KEPT IT GOING FOR NOW DUE TO LIGHT SNOW GOING THROUGH AND STRONG WINDS ALLOWING THAT TO BLOW AROUND...WINDS AT ADVISORY LEVEL...AND COLD AIR ALLOWING RECENT WATER TO FREEZE. WE SHOULD ALSO SEE SOME CLEARING TODAY SOUTHWEST TO NORTHEAST AS DRIER/SUBSIDENT AIR OVER THE PLAINS ADVECTS IN BEHIND THE SYSTEM. THIS CLEARING IS WELL EVIDENT OVER WESTERN IOWA AND FAR SOUTHWEST MN CURRENTLY. THE DRIER AIR HOLDS INTO TONIGHT...SO ALTHOUGH SOME SHORTWAVES ROTATING AROUND THE UPPER LOW ARE PROGGED TO COME ACROSS THE FORECAST AREA...NO PRECIPITATION OR EVEN CLOUD IMPACTS ARE EXPECTED FROM THEM. 925MB TEMPERATURES OF -8 TO -12C TODAY WILL RESULT IN MUCH COOLER HIGHS TODAY COMPARED TO YESTERDAY...AS MUCH AS 15 TO 20 DEGREES COLDER. 925MB TEMPS COOL EVEN MORE TONIGHT...TO -10 TO -16C BY 12Z SATURDAY...COLDEST NORTH. HAVING MOSTLY CLEAR SKIES...COOLING TEMPS AND FRESH SNOW IS CONCERNING FOR TEMPERATURES TO TANK...BUT MIXING OF THE WINDS SHOULD HELP KEEP MOST LOCATIONS ABOVE 0F. THE LONE EXCEPTION TO GO BELOW ZERO COULD BE UP IN TAYLOR COUNTY WHERE THE COLDEST AIR IS FLOWING IN. COMBINATION OF THE WINDS AND FALLING TEMPS BRINGS WIND CHILLS CLOSE BUT NOT TO -20F...WHEN WE WOULD ISSUE WIND CHILL ADVISORIES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 214 AM CST FRI FEB 21 2014 MUCH OF THE LONG TERM PERIOD IS DOMINATED BY A STUCK UPPER LEVEL PATTERN...RESULTING FROM AN OMEGA BLOCK THAT DEVELOPS AND STRENGTHENS FROM ALONG THE U.S. WEST COAST INTO FAR WESTERN CANADA. THE STRENGTHENING OMEGA BLOCK CORRELATES WELL WITH A STRATOSPHERIC WARMING EVENT TAKING PLACE OVER THE ALEUTIANS THE NEXT FEW DAYS. THIS OMEGA BLOCK WILL ALLOW A SERIES OF SHORTWAVE TROUGHS DROPPING OUT OF THE ARCTIC TO COME THROUGH THE FORECAST AREA. IN THE WAKE OF EACH TROUGH...A SURGE OF COLDER AIR WITH ARCTIC HIGH PRESSURE WILL FOLLOW. GIVEN THE ARCTIC NATURE OF THE SHORTWAVES...MOISTURE AND PRECIPITATION IS GOING TO BE HARD TO COME BY. THE ONLY REAL CHANCE IT LOOKS LIKE FOR SNOW WILL COME MONDAY INTO MONDAY NIGHT WITH A SHORTWAVE TROUGH DROPPING THROUGH THEN. STILL...AT THIS POINT...IT DOES NOT APPEAR TO BE A BIG SNOW PRODUCER. HIGHEST CHANCES ARE SITUATED OVER THE SOUTHWEST HALF OF THE FORECAST AREA. NOW THE MAIN IMPACT ISSUE...THE COLD...WHICH HAS BEEN CONSISTENTLY FORECASTED FROM THE ECMWF/GFS AND CFS. HAVING ARCTIC COLD FLOW INTO THE FORECAST AREA ALSO CORRELATES WELL WITH THE AFOREMENTIONED STRATOSPHERIC WARMING OVER THE ALEUTIANS. THE WEEKEND...925MB TEMPS ARE NOT FORECAST TO CHANGE MUCH THROUGH THE WEEKEND FROM THE -10 TO -16C PROGGED AT 12Z SATURDAY. THIS SHOULD RESULT IN HIGHS SIMILAR FOR BOTH DAYS...RANGING FROM THE LOW TEENS TO LOW 20S. TEMPERATURES SATURDAY NIGHT COULD FALL QUITE A BIT WITH A WEAKER PRESSURE GRADIENT. TYPICAL COLD SPOTS WILL LIKELY DECOUPLE...ALLOWING THEM TO APPROACH 10 BELOW. WIND CHILLS MAY FLIRT WITH ADVISORY CRITERIA AS WELL SUNDAY MORNING. NEXT WEEK...BEHIND THE MONDAY SHORTWAVE TROUGH...925MB TEMPS FALL TO -18 TO -22C BY 12Z TUESDAY PER 21.00Z ECMWF/GFS. A COLDER SURGE COMES IN TUESDAY NIGHT BEHIND ANOTHER SHORTWAVE TROUGH...WITH THOSE 925MB TEMPS DOWN TO -22 TO -26C AT 12Z WEDNESDAY. MORE IMPORTANTLY WITH THIS COLD SURGE IS STRONGER 925MB WINDS OF 25-35 KTS...WHICH RESULTS IN WIND CHILL ADVISORY NEED. THE FINAL AND COLDEST OF THE COLD COMES WEDNESDAY NIGHT INTO THURSDAY. 925MB TEMPS ARE SIMILAR TO THE TUESDAY NIGHT SURGE...BUT 850MB TEMPS APPROACH -30C IN TAYLOR COUNTY...SUGGESTING A DEEPER COLDER AIRMASS. AND LIKE TUESDAY NIGHT...PLENTY OF WIND IS FORECAST...SO WIND CHILL ADVISORY HAZARDS LOOK LIKELY. IN FACT...LOWS THEMSELVES SHOULD BE IN THE SINGLE DIGITS TO TEENS BELOW ZERO TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1150 AM CST FRI FEB 21 2014 STRONG WEST WINDS AT 20 TO 30 WITH GUSTS TO 35 WILL PERSIST THROUGH MUCH OF THE AFTERNOON HOURS...PER LATEST RAP SOUNDINGS. KRST/KLSE ON CLEARING EDGE OF THE CLOUDS...VIA SFC OBS AND SATELLITE IMAGERY. OBS MAY POINT TO SOME CIGS FROM BLOWING SNOW. GOING TO KEEP VSBY RESTRICTIONS AT KRST THROUGH THE AFTERNOON. VFR CONDITIONS SHOULD BE THE RULE TONIGHT INTO SATURDAY WITH SKC SKIES AND WINDS TAPERING OFF INTO THE 10 TO 15 KT RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ017- 029-032>034. WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ041>044-053>055-061. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ079- 086>088-094-095. WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ096. IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ008>010-018-019-029. WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ011- 030. && $$ UPDATED......RIECK SHORT TERM...AJ LONG TERM....AJ AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
540 AM CST FRI FEB 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 214 AM CST FRI FEB 21 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED NORTHWEST FLOW FROM ALASKA DOWN INTO THE MID-MISSISSIPPI RIVER VALLEY AND A DEEP UPPER LOW OVER NORTHERN WI. UNDERNEATH THE UPPER LOW WAS A 978 MB SURFACE LOW NEAR RHINELANDER. A VERY TIGHT PRESSURE GRADIENT SOUTHWEST OF THE LOW WAS SUPPORTING SURFACE WINDS OF 25 TO 35 MPH WITH GUSTS UP TO 55 MPH. THE COLD CONVEYOR BELT WRAPPING AROUND THE NEARLY VERTICALLY STACKED LOW WAS STILL BRINGING SNOW TO THE FORECAST AREA...HEAVIEST OVER NORTH CENTRAL WI. EARLIER LAST EVENING THE STRONG WINDS WERE NOT REDUCING VISIBILITIES THAT MUCH IN SOUTHEAST MN/NORTHEAST IA PER ASOS/AWOS OBSERVATIONS...DUE TO THE WET NATURE OF THE SNOW. HOWEVER...CALLS TO COUNTY SHERIFFS IN THE SAME AREA WERE REPORTING WHITEOUTS WITH SOME ROADS CLOSED...SUGGESTING ASOS/AWOS OBSERVATIONS WERE NOT FULLY REPRESENTATIVE. IN ADDITION...POWER OUTAGES WERE A MAJOR ISSUE WITH THE WEIGHT OF THE WET SNOW ON TREES/POWER LINES AND WINDS. NOW THE WINDS HAVE ADVECTED COLDER AIR INTO THE FORECAST AREA AS NOTED BY TEMPERATURES IN THE TEENS TO LOW 20S. THE COLDER AIR HAS ALLOWED THE SNOW TO BECOME DRIER...MORE ABLE TO BLOW. THE NEARLY VERTICALLY STACKED LOW WILL CONTINUE LIFTING NORTHEASTWARD OVER THE NEXT 24 HOURS...REACHING NORTHERN ONTARIO THIS EVENING. AS THE LOW PULLS AWAY...THE WINDS WILL GRADUALLY RELAX...DROPPING FROM 20 TO 35 MPH WITH HIGHER GUSTS DURING THE MORNING TO 10 TO 25 MPH BY 00Z. FURTHER DIMINISHING OF THE WINDS ARE EXPECTED TONIGHT. IN TERMS OF THE COLD CONVEYOR BELT OF SNOW...GOOD AGREEMENT EXISTS THAT THE SNOW SHOULD EXIT MOST LOCATIONS WEST OF THE MISSISSIPPI RIVER BY 12Z...LOCATIONS SOUTHWEST OF I-94 BY 18Z...AND THE CHIMNEY AREA BY 00Z. MUCH OF THE SNOW SHOULD BE LIGHT WITH THE SYSTEM OCCLUDED AND MOVING AWAY. JUXTAPOSITION OF THE WINDS AND SNOW SUGGESTS CONTINUATION OF HAZARDS OVER THE NORTHWEST HALF OF THE FORECAST AREA. CONTEMPLATED RIGHT NOW CANCELING SOME OF THE WINTER WEATHER ADVISORY...BUT HAVE KEPT IT GOING FOR NOW DUE TO LIGHT SNOW GOING THROUGH AND STRONG WINDS ALLOWING THAT TO BLOW AROUND...WINDS AT ADVISORY LEVEL...AND COLD AIR ALLOWING RECENT WATER TO FREEZE. WE SHOULD ALSO SEE SOME CLEARING TODAY SOUTHWEST TO NORTHEAST AS DRIER/SUBSIDENT AIR OVER THE PLAINS ADVECTS IN BEHIND THE SYSTEM. THIS CLEARING IS WELL EVIDENT OVER WESTERN IOWA AND FAR SOUTHWEST MN CURRENTLY. THE DRIER AIR HOLDS INTO TONIGHT...SO ALTHOUGH SOME SHORTWAVES ROTATING AROUND THE UPPER LOW ARE PROGGED TO COME ACROSS THE FORECAST AREA...NO PRECIPITATION OR EVEN CLOUD IMPACTS ARE EXPECTED FROM THEM. 925MB TEMPERATURES OF -8 TO -12C TODAY WILL RESULT IN MUCH COOLER HIGHS TODAY COMPARED TO YESTERDAY...AS MUCH AS 15 TO 20 DEGREES COLDER. 925MB TEMPS COOL EVEN MORE TONIGHT...TO -10 TO -16C BY 12Z SATURDAY...COLDEST NORTH. HAVING MOSTLY CLEAR SKIES...COOLING TEMPS AND FRESH SNOW IS CONCERNING FOR TEMPERATURES TO TANK...BUT MIXING OF THE WINDS SHOULD HELP KEEP MOST LOCATIONS ABOVE 0F. THE LONE EXCEPTION TO GO BELOW ZERO COULD BE UP IN TAYLOR COUNTY WHERE THE COLDEST AIR IS FLOWING IN. COMBINATION OF THE WINDS AND FALLING TEMPS BRINGS WIND CHILLS CLOSE BUT NOT TO -20F...WHEN WE WOULD ISSUE WIND CHILL ADVISORIES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 214 AM CST FRI FEB 21 2014 MUCH OF THE LONG TERM PERIOD IS DOMINATED BY A STUCK UPPER LEVEL PATTERN...RESULTING FROM AN OMEGA BLOCK THAT DEVELOPS AND STRENGTHENS FROM ALONG THE U.S. WEST COAST INTO FAR WESTERN CANADA. THE STRENGTHENING OMEGA BLOCK CORRELATES WELL WITH A STRATOSPHERIC WARMING EVENT TAKING PLACE OVER THE ALEUTIANS THE NEXT FEW DAYS. THIS OMEGA BLOCK WILL ALLOW A SERIES OF SHORTWAVE TROUGHS DROPPING OUT OF THE ARCTIC TO COME THROUGH THE FORECAST AREA. IN THE WAKE OF EACH TROUGH...A SURGE OF COLDER AIR WITH ARCTIC HIGH PRESSURE WILL FOLLOW. GIVEN THE ARCTIC NATURE OF THE SHORTWAVES...MOISTURE AND PRECIPITATION IS GOING TO BE HARD TO COME BY. THE ONLY REAL CHANCE IT LOOKS LIKE FOR SNOW WILL COME MONDAY INTO MONDAY NIGHT WITH A SHORTWAVE TROUGH DROPPING THROUGH THEN. STILL...AT THIS POINT...IT DOES NOT APPEAR TO BE A BIG SNOW PRODUCER. HIGHEST CHANCES ARE SITUATED OVER THE SOUTHWEST HALF OF THE FORECAST AREA. NOW THE MAIN IMPACT ISSUE...THE COLD...WHICH HAS BEEN CONSISTENTLY FORECASTED FROM THE ECMWF/GFS AND CFS. HAVING ARCTIC COLD FLOW INTO THE FORECAST AREA ALSO CORRELATES WELL WITH THE AFOREMENTIONED STRATOSPHERIC WARMING OVER THE ALEUTIANS. THE WEEKEND...925MB TEMPS ARE NOT FORECAST TO CHANGE MUCH THROUGH THE WEEKEND FROM THE -10 TO -16C PROGGED AT 12Z SATURDAY. THIS SHOULD RESULT IN HIGHS SIMILAR FOR BOTH DAYS...RANGING FROM THE LOW TEENS TO LOW 20S. TEMPERATURES SATURDAY NIGHT COULD FALL QUITE A BIT WITH A WEAKER PRESSURE GRADIENT. TYPICAL COLD SPOTS WILL LIKELY DECOUPLE...ALLOWING THEM TO APPROACH 10 BELOW. WIND CHILLS MAY FLIRT WITH ADVISORY CRITERIA AS WELL SUNDAY MORNING. NEXT WEEK...BEHIND THE MONDAY SHORTWAVE TROUGH...925MB TEMPS FALL TO -18 TO -22C BY 12Z TUESDAY PER 21.00Z ECMWF/GFS. A COLDER SURGE COMES IN TUESDAY NIGHT BEHIND ANOTHER SHORTWAVE TROUGH...WITH THOSE 925MB TEMPS DOWN TO -22 TO -26C AT 12Z WEDNESDAY. MORE IMPORTANTLY WITH THIS COLD SURGE IS STRONGER 925MB WINDS OF 25-35 KTS...WHICH RESULTS IN WIND CHILL ADVISORY NEED. THE FINAL AND COLDEST OF THE COLD COMES WEDNESDAY NIGHT INTO THURSDAY. 925MB TEMPS ARE SIMILAR TO THE TUESDAY NIGHT SURGE...BUT 850MB TEMPS APPROACH -30C IN TAYLOR COUNTY...SUGGESTING A DEEPER COLDER AIRMASS. AND LIKE TUESDAY NIGHT...PLENTY OF WIND IS FORECAST...SO WIND CHILL ADVISORY HAZARDS LOOK LIKELY. IN FACT...LOWS THEMSELVES SHOULD BE IN THE SINGLE DIGITS TO TEENS BELOW ZERO TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 540 AM CST FRI FEB 21 2014 THE STRONG LOW WAS ALREADY IN THE U.P. OF MI EARLY THIS MORNING... CONTINUING TO MOVE AWAY FROM THE AREA. TAF SITES WERE ALREADY ON THE EDGE OF THE TRAILING -SN...WHICH LOOKS TO BE OUT OF BOTH TAF SITES BY 14Z. CIGS HAD GENERALLY COME UP TO THE 1500-2500FT RANGE...WITH THE DECREASE OF CLOUDS/CLEARING LINE NEAR MANKATO MN TO JUST WEST OF WATERLOO IA. BROUGHT THIS INTO/THRU THE TAF SITES AROUND 18Z...BUT IT MAY OCCUR SOONER AT KRST. BIGGEST REMAINING PROBLEM AT THE TAF SITES IS THE STRONG GRADIENT WINDS BEHIND THE LOW WHICH WILL PERSIST ACROSS THE AREA TODAY. THESE WINDS TO PRODUCE IFR/MVFR VSBYS IN BLSN AT SITES LIKE KRST THRU MUCH OF THE MORNING. VSBYS AT KRST SHOULD GRADUALLY IMPROVE TO MVFR BY LATE MORNING BUT WITH WINDS EXPECTED TO GUST 30-35KTS MVFR VSBYS LOOK TO LINGER AT KRST MUCH OF THE AFTERNOON. WINDS DIMINISH TO 15-20KTS THIS EVENING...WITH VFR CONDITIONS TONIGHT INTO SAT MORNING AS COLDER/DRIER ARCTIC HIGH PRESSURE GRADUALLY BUILDS IN. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ041>044- 053>055-061. WINTER STORM WARNING UNTIL NOON CST TODAY FOR WIZ017-029-032>034. MN...BLIZZARD WARNING UNTIL NOON CST TODAY FOR MNZ079-086-087-094-095. WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ096. WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ088. IA...BLIZZARD WARNING UNTIL NOON CST TODAY FOR IAZ008>010-018-019-029. WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ011-030. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
214 AM CST FRI FEB 21 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 214 AM CST FRI FEB 21 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED NORTHWEST FLOW FROM ALASKA DOWN INTO THE MID-MISSISSIPPI RIVER VALLEY AND A DEEP UPPER LOW OVER NORTHERN WI. UNDERNEATH THE UPPER LOW WAS A 978 MB SURFACE LOW NEAR RHINELANDER. A VERY TIGHT PRESSURE GRADIENT SOUTHWEST OF THE LOW WAS SUPPORTING SURFACE WINDS OF 25 TO 35 MPH WITH GUSTS UP TO 55 MPH. THE COLD CONVEYOR BELT WRAPPING AROUND THE NEARLY VERTICALLY STACKED LOW WAS STILL BRINGING SNOW TO THE FORECAST AREA...HEAVIEST OVER NORTH CENTRAL WI. EARLIER LAST EVENING THE STRONG WINDS WERE NOT REDUCING VISIBILITIES THAT MUCH IN SOUTHEAST MN/NORTHEAST IA PER ASOS/AWOS OBSERVATIONS...DUE TO THE WET NATURE OF THE SNOW. HOWEVER...CALLS TO COUNTY SHERIFFS IN THE SAME AREA WERE REPORTING WHITEOUTS WITH SOME ROADS CLOSED...SUGGESTING ASOS/AWOS OBSERVATIONS WERE NOT FULLY REPRESENTATIVE. IN ADDITION...POWER OUTAGES WERE A MAJOR ISSUE WITH THE WEIGHT OF THE WET SNOW ON TREES/POWER LINES AND WINDS. NOW THE WINDS HAVE ADVECTED COLDER AIR INTO THE FORECAST AREA AS NOTED BY TEMPERATURES IN THE TEENS TO LOW 20S. THE COLDER AIR HAS ALLOWED THE SNOW TO BECOME DRIER...MORE ABLE TO BLOW. THE NEARLY VERTICALLY STACKED LOW WILL CONTINUE LIFTING NORTHEASTWARD OVER THE NEXT 24 HOURS...REACHING NORTHERN ONTARIO THIS EVENING. AS THE LOW PULLS AWAY...THE WINDS WILL GRADUALLY RELAX...DROPPING FROM 20 TO 35 MPH WITH HIGHER GUSTS DURING THE MORNING TO 10 TO 25 MPH BY 00Z. FURTHER DIMINISHING OF THE WINDS ARE EXPECTED TONIGHT. IN TERMS OF THE COLD CONVEYOR BELT OF SNOW...GOOD AGREEMENT EXISTS THAT THE SNOW SHOULD EXIT MOST LOCATIONS WEST OF THE MISSISSIPPI RIVER BY 12Z...LOCATIONS SOUTHWEST OF I-94 BY 18Z...AND THE CHIMNEY AREA BY 00Z. MUCH OF THE SNOW SHOULD BE LIGHT WITH THE SYSTEM OCCLUDED AND MOVING AWAY. JUXTAPOSITION OF THE WINDS AND SNOW SUGGESTS CONTINUATION OF HAZARDS OVER THE NORTHWEST HALF OF THE FORECAST AREA. CONTEMPLATED RIGHT NOW CANCELING SOME OF THE WINTER WEATHER ADVISORY...BUT HAVE KEPT IT GOING FOR NOW DUE TO LIGHT SNOW GOING THROUGH AND STRONG WINDS ALLOWING THAT TO BLOW AROUND...WINDS AT ADVISORY LEVEL...AND COLD AIR ALLOWING RECENT WATER TO FREEZE. WE SHOULD ALSO SEE SOME CLEARING TODAY SOUTHWEST TO NORTHEAST AS DRIER/SUBSIDENT AIR OVER THE PLAINS ADVECTS IN BEHIND THE SYSTEM. THIS CLEARING IS WELL EVIDENT OVER WESTERN IOWA AND FAR SOUTHWEST MN CURRENTLY. THE DRIER AIR HOLDS INTO TONIGHT...SO ALTHOUGH SOME SHORTWAVES ROTATING AROUND THE UPPER LOW ARE PROGGED TO COME ACROSS THE FORECAST AREA...NO PRECIPITATION OR EVEN CLOUD IMPACTS ARE EXPECTED FROM THEM. 925MB TEMPERATURES OF -8 TO -12C TODAY WILL RESULT IN MUCH COOLER HIGHS TODAY COMPARED TO YESTERDAY...AS MUCH AS 15 TO 20 DEGREES COLDER. 925MB TEMPS COOL EVEN MORE TONIGHT...TO -10 TO -16C BY 12Z SATURDAY...COLDEST NORTH. HAVING MOSTLY CLEAR SKIES...COOLING TEMPS AND FRESH SNOW IS CONCERNING FOR TEMPERATURES TO TANK...BUT MIXING OF THE WINDS SHOULD HELP KEEP MOST LOCATIONS ABOVE 0F. THE LONE EXCEPTION TO GO BELOW ZERO COULD BE UP IN TAYLOR COUNTY WHERE THE COLDEST AIR IS FLOWING IN. COMBINATION OF THE WINDS AND FALLING TEMPS BRINGS WIND CHILLS CLOSE BUT NOT TO -20F...WHEN WE WOULD ISSUE WIND CHILL ADVISORIES. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 214 AM CST FRI FEB 21 2014 MUCH OF THE LONG TERM PERIOD IS DOMINATED BY A STUCK UPPER LEVEL PATTERN...RESULTING FROM AN OMEGA BLOCK THAT DEVELOPS AND STRENGTHENS FROM ALONG THE U.S. WEST COAST INTO FAR WESTERN CANADA. THE STRENGTHENING OMEGA BLOCK CORRELATES WELL WITH A STRATOSPHERIC WARMING EVENT TAKING PLACE OVER THE ALEUTIANS THE NEXT FEW DAYS. THIS OMEGA BLOCK WILL ALLOW A SERIES OF SHORTWAVE TROUGHS DROPPING OUT OF THE ARCTIC TO COME THROUGH THE FORECAST AREA. IN THE WAKE OF EACH TROUGH...A SURGE OF COLDER AIR WITH ARCTIC HIGH PRESSURE WILL FOLLOW. GIVEN THE ARCTIC NATURE OF THE SHORTWAVES...MOISTURE AND PRECIPITATION IS GOING TO BE HARD TO COME BY. THE ONLY REAL CHANCE IT LOOKS LIKE FOR SNOW WILL COME MONDAY INTO MONDAY NIGHT WITH A SHORTWAVE TROUGH DROPPING THROUGH THEN. STILL...AT THIS POINT...IT DOES NOT APPEAR TO BE A BIG SNOW PRODUCER. HIGHEST CHANCES ARE SITUATED OVER THE SOUTHWEST HALF OF THE FORECAST AREA. NOW THE MAIN IMPACT ISSUE...THE COLD...WHICH HAS BEEN CONSISTENTLY FORECASTED FROM THE ECMWF/GFS AND CFS. HAVING ARCTIC COLD FLOW INTO THE FORECAST AREA ALSO CORRELATES WELL WITH THE AFOREMENTIONED STRATOSPHERIC WARMING OVER THE ALEUTIANS. THE WEEKEND...925MB TEMPS ARE NOT FORECAST TO CHANGE MUCH THROUGH THE WEEKEND FROM THE -10 TO -16C PROGGED AT 12Z SATURDAY. THIS SHOULD RESULT IN HIGHS SIMILAR FOR BOTH DAYS...RANGING FROM THE LOW TEENS TO LOW 20S. TEMPERATURES SATURDAY NIGHT COULD FALL QUITE A BIT WITH A WEAKER PRESSURE GRADIENT. TYPICAL COLD SPOTS WILL LIKELY DECOUPLE...ALLOWING THEM TO APPROACH 10 BELOW. WIND CHILLS MAY FLIRT WITH ADVISORY CRITERIA AS WELL SUNDAY MORNING. NEXT WEEK...BEHIND THE MONDAY SHORTWAVE TROUGH...925MB TEMPS FALL TO -18 TO -22C BY 12Z TUESDAY PER 21.00Z ECMWF/GFS. A COLDER SURGE COMES IN TUESDAY NIGHT BEHIND ANOTHER SHORTWAVE TROUGH...WITH THOSE 925MB TEMPS DOWN TO -22 TO -26C AT 12Z WEDNESDAY. MORE IMPORTANTLY WITH THIS COLD SURGE IS STRONGER 925MB WINDS OF 25-35 KTS...WHICH RESULTS IN WIND CHILL ADVISORY NEED. THE FINAL AND COLDEST OF THE COLD COMES WEDNESDAY NIGHT INTO THURSDAY. 925MB TEMPS ARE SIMILAR TO THE TUESDAY NIGHT SURGE...BUT 850MB TEMPS APPROACH -30C IN TAYLOR COUNTY...SUGGESTING A DEEPER COLDER AIRMASS. AND LIKE TUESDAY NIGHT...PLENTY OF WIND IS FORECAST...SO WIND CHILL ADVISORY HAZARDS LOOK LIKELY. IN FACT...LOWS THEMSELVES SHOULD BE IN THE SINGLE DIGITS TO TEENS BELOW ZERO TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1118 PM CST THU FEB 20 2014 THE SNOW WITH THE STORM SYSTEM CONTINUES TO LIFT SLOWLY NORTHEAST WITH THE RADAR SHOWING THE HEAVIEST SNOW NOW NORTH OF BOTH TAF SITES. EXPECT THIS TREND TO CONTINUE THROUGH THE NIGHT AS THE LOW CONTINUES TO PULL OFF TO THE NORTH/NORTHEAST WITH THE SNOW ENDING BEFORE 12Z AT BOTH SITES. THE STRONGEST WINDS ARE JUST MOVING INTO THE AREA AND EXPECT THE GUSTS OF 35 TO 40 KNOTS TO CONTINUE FOR MUCH OF THE NIGHT WITH SOME DECREASE EXPECTED TO OCCUR BY MID MORNING FRIDAY WITH THE GUSTS COMING DOWN TO 30 TO 35 KNOTS. THESE WINDS WILL PRODUCE BLOWING SNOW AT KRST WITH IFR VISIBILITIES EXPECTED UNTIL THE WINDS SETTLE DOWN A LITTLE BIT TO ALLOW THE VISIBILITY TO COME UP TO MVFR. THE WINDS SHOULD THEN STAY STRONG ENOUGH TO CONTINUE TO PRODUCE SOME BLOWING SNOW THROUGH MUCH OF THE DAY. CEILINGS PRIMARILY EXPECTED TO BE MVFR UNTIL THE CLOUDS SCATTER OUT EARLY FRIDAY AFTERNOON. THE WINDS SHOULD SETTLE DOWN EVEN MORE LATE FRIDAY AFTERNOON OR EARLY EVENING AS THE GRADIENT RELAXES SOME MORE AND THE LOW LEVEL INVERSION BEGINS TO DEVELOP. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ041>044- 053>055-061. WINTER STORM WARNING UNTIL NOON CST TODAY FOR WIZ017-029-032>034. MN...BLIZZARD WARNING UNTIL NOON CST TODAY FOR MNZ079-086-087-094-095. WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ096. WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ088. IA...BLIZZARD WARNING UNTIL NOON CST TODAY FOR IAZ008>010-018-019-029. WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR IAZ011-030. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...04
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
355 AM EST Sun Feb 23 2014 ...Heavy Rain Possible Across the Florida Panhandle Today... .Near Term [Through Today]... The large scale pattern is highlighted by a persistent broad trough over much of Conus. This leaves nearly zonal flow over NE Gulf region. However a series of shortwaves will continue to move Ewd providing increasing clouds and just enough lift that when combined with surface features will maintain an unsettled weather pattern today. Mid-High clouds streaming Ewd overnight assocd with lead shortwave moving Ewd across mid-South will cross NE Gulf region later today with the forecast area in the right entrance region of the upper jet. At surface...in response to Ewd moving shortwave... W-E warm front located across the Nrn Gulf waters Ewd across N/Cntrl FL overnight will lift Nwd to coast by sunrise then to vcnty of I-10 during the day with light Sly flow in its wake. Upstream cold front across mid-South around sunrise moves SEWD to Ern TN/N-Cntrl AL/Srn MS by sundown with WAA and isentropic upglide spreading over our area. Early radar showing leading edge of moisture approaching wrn most Panhandle waters. Patchy to areas of fog initially south of I-10 will accompany rain and spread E/N thru the day. The combination of upper and lower features will yield an expansive area of showers with isolated to sct thunderstorms (highest Panhandle waters) moving SW-NE to reach our Wrn CWA around sunrise and then progress EWD. Afternoon dew point will rise from mid 60s coast to upper 50s Nrn tier AL/GA counties. This depicted well in HRRR and other High Res guidance. Limited mid-level lapse rates and a relatively cool boundary layer should limit the potential for any strong storms. Best chance per CAM would be Panhandle waters. However, with the upper flow parallel to the warm boundary, main concern is training of cells is possible with locally heavy rainfall possible especially during the aftn QPF south of FL border exceeding 1 inch. Will go with 70-30% W-E POP gradient in morning then 80-40% in the afternoon. Temperatures will be tricky, depending on the eventual position of the warm front and the coverage of the rainfall. However, expect warmest temperatures along and south of I-10 (lower 70s), with lower to mid 60s for much of SE AL and SW GA. .Short Term [Tonight Through Tuesday]... By the time the evening rolls around, the polar jet max will be racing east and the northern stream trough will dip a bit deeper into the Southeast. This will act to better stack the frontal system as surface high pressure presses a cold front into our region. The surface cold front will merge with Sunday`s warm front and settle in over north Florida before deep layer zonal flow sets in and stalls the frontal system once again. As the two fronts merge, and the system stacks, we`ll likely see a brief uptick in shower activity along the surface front. Expect rainfall to be much lighter than Sunday afternoon as the surge of more tropical- like moisture will have moved east. On Monday, a southern stream impulse will be lifting north through the northern Gulf, eventually aligning with the surface front and pressing the northern stream trough back to the north out of our area. Exactly where the surface front will be is a bit uncertain, though the most likely scenario would place the front along or south of I-10 in north Florida, possibly as far south as the extreme northern Gulf. Should the surface front be positioned across north Florida, things could become interesting with respect to the potential for an isolated strong storm. Due to the limited tropospheric penetration of the southern stream impulse, the mid- level cooler/drier air will not be forced as aggressively to the north. This will effectively steepen mid-level lapse rates across the Tri-State region with deep layer shear around 60 knots more than sufficient to support organized updrafts. In the other corner, slightly warmer mid/upper level temps where the northern stream trough has retreated a bit, will essentially cap the potential for deep moist convection, though as the southern stream impulse moves away, cooler mid/upper temps may slide back south late in the day, eroding the cap. Bottom line is that there is a very low potential for strong storms on Monday, though should convection get going, and should the mid/upper level cap erode the potential exists for a storm or two to produce gusty winds and possibly some small hail. Tuesday, is really the more interesting day as a more potent southern stream impulse races east out of Texas, through the lower MS Valley and into the southeast by the late afternoon. Should we be able to mix out the mid-level cap early enough that the shortwave is overhead, we`d be able to tap into some rather steep lapse rates and strong deep layer shear. This could support the development of more severe level storms with the threat for damaging winds and hail. So, through Tuesday expect showers and isolated storms to be around. Most likely across north Florida Monday, spreading further inland and increasing in coverage on Tuesday. The potential for a strong storm or two exists on Monday, with a chance for severe storms on Tuesday. Uncertainty remains very high regarding strong to severe storms, as my lengthy discussion above lays out all of the variables that must align just right. Expect above average temperatures, in the middle to even upper 70s in some spots, both Monday and Tuesday. .Long Term [Tuesday Night Through Sunday]... A cold front will move through Wednesday with a chance of showers and thunderstorms. Behind the front high pressure will build in bringing cooler temperatures and drier air. The models differ with a series of low pressure systems at the end of the period. The GFS has precipitation moving across central Florida Friday and a low developing off the East coast near Georgia and South Carolina followed by another low forming over Texas. The Euro has a Gulf low forming near the Texas/Louisiana border Friday night then moving across north Florida Saturday. && .Aviation... [Through 06Z Monday] MVFR CIGS should develop during the predawn hours or shortly after sunrise at ECP, TLH and VLD, lowering to IFR CIGS during the morning hours. There will be a chance of MVFR CIGS at DHN and ABY during the day tomorrow as well. With a prolonged rain event any improvement in evening VSBYS/CIGS will begin to again lower after 02z and winds die off. Rain and isold thunderstorms will move in from the west during the morning. Heaviest rain and thunderstorm activity will likely be focused in Florida Panhandle particularly at ECP, but also possibly affecting TLH. Main impact would be through reduced visibility due to very heavy rain. Thunderstorms may also linger at ECP or TLH south of warm front for several hours in the afternoon. && .Marine... Generally low winds and seas will prevail through mid-week until a cold front passes through the northern Gulf increasing winds to advisory levels temporarily on Wednesday. Low winds and seas will return to finish out the week. && .Fire Weather... With increased rain chances thru tonight, no red flag conditions are expected and none is forecast through mid-next week. && .Hydrology... There is a potential for heavy rainfall this afternoon with the heaviest rain likely confined to north Florida, especially along and west of the Apalachicola River. Widespread average totals will be around 1-2 inches with isolated spots possibly receiving up to 3 to 5 inches. Flash flooding will likely not be a concern as these basins should be able to accommodate the expected rainfall amounts. In areas where heavy rainfall is expected, rivers may reach minor flood stage Monday or Tuesday. The Apalachicola at Blountstown is forecast to reach minor flood stage Sunday morning. For the latest hydrology information, please monitor: www.water.weather.gov/ahps2/index.php?wfo=tae && .Preliminary Point Temps/PoPs... Tallahassee 69 59 75 54 74 / 70 70 40 10 50 Panama City 67 60 70 57 69 / 80 70 40 20 50 Dothan 64 56 73 51 71 / 70 50 10 10 50 Albany 65 55 73 49 72 / 70 50 10 10 40 Valdosta 70 58 75 53 73 / 70 70 40 10 40 Cross City 73 60 75 57 75 / 50 70 40 10 50 Apalachicola 67 61 69 58 67 / 60 70 40 10 50 && .TAE Watches/Warnings/Advisories... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...BLOCK SHORT TERM...HARRIGAN LONG TERM...WESTON AVIATION...BLOCK MARINE...HARRIGAN FIRE WEATHER...BLOCK HYDROLOGY...HARRIGAN/WESTON Area Forecast Discussion National Weather Service Lincoln IL 330 AM CST Sun Feb 23 2014 .DISCUSSION... ISSUED 330 AM CST Sun Feb 23 2014 SHORT TERM...Today through Wednesday night Surface cold front has pressed south of the Ohio River into nw AR while 1042 mb arctic high pressure over Alberta was nosing into the central and northern plains. Colder air easing south into central IL early this morning with temps slipping through the 20s over central IL and low to mid 30s in southeast IL. Temps as cold as 19F at Galesburg and Lacon. Frontogenetic forecasing close to 850 mb boundary near I-70 had band of light snow that diminished east into central IN past few hours with dusting to as much as 1 inch between I-72 and I-70. Will carry just slight chance of light snow this morning over southeast IL per HRRR model run. Radar mosaic shows light pcpn returns and mainly virga over northern MO into nw counties. RUC & HRRR keeps most of this very light snow west of central IL this morning but could be a few flurries this morning into central IL. Clouds to decrease from the north during the afternoon and linger longest in southeast IL. Much colder highs today range from mid 20s from Peoria and Bloomington north to 35-40F over southeast IL with Lawrenceville near 40F. Arctic high pressure noses into the mid MS river valley tonight and brings fair skies and cold lows of 5-10F from Lincoln north and mid to upper teens in southeast IL. Clouds increase Monday morning ahead of northern stream clipper system which digs into the Midwest Monday night. Slowed down chances of light snow Monday afternoon as central IL appear dry through sunset Monday with best chances of light snow arriving Monday night northern half of CWA. Generally less than 1 inch of snow with northern IL having as much as 1-2 inches of snow possible. Highs Monday again in mid 20s north and mid to upper 30s in southeast IL. Lows Monday night in the teens central IL and lower 20s southeast IL. Chances of light snow ne of central IL by Tuesday morning. Highs Tue range from lower 20s northern areas to mid 30s in southeast IL. Core of arctic high pressure settles into MO by 18Z/noon Wed and brings even colder air into the region during middle of the week. Lows overnight Tue night into early Wed morning could reach zero to 5 below nw of IL river with single digit lows over much of central IL and far southeast IL around 10F. Highs Wed in the mid teens ne to lower 20s sw and se areas. Lows Wed night again in the single digits over northern half of CWA and lower teens south. LONG TERM...Thursday through Saturday night Temps modify slightly during end of week but still average below normal through next weekend. The 8-14 day outlook for Mar 2-8 has 60-70% chance of below normal temperatures and 40% chance of above normal precipitation, which has been the normal for this winter. Generally dry and cold conditions expected late this week into next weekend. Though ECMWF and GEM models show some light qpf Friday while heavier qpf passes south of IL Friday. GFS model is dry over IL on Friday. Stayed close to ALLblend pops late this week and into the weekend which is dry. 07 && .AVIATION... ISSUED 1140 PM CST Sat Feb 22 2014 Persistent band of snow has now shifted southeast of the KILX terminals, so VFR conditions are expected through the entire 06z TAF period. Winds will remain northerly at less than 10kt tonight through Sunday afternoon before backing to northwesterly by evening. Only mid/upper-level clouds are expected as weak disturbances embedded within broad northwesterly flow aloft pass through the area over the next 24 hours. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
214 AM CST SUN FEB 23 2014 .DISCUSSION... 213 AM CST TODAY... BROAD SFC RIDGE STRETCHES FROM THE NORTHERN PLAINS SOUTHEAST THROUGH THE WESTERN OHIO VALLEY. THIS HAS RESULTED IN A LIGHT NORTHWEST FLOW ACROSS NORTHERN IL/NORTHWEST IN EARLY THIS MORNING. BAROCLINIC ZONE REMAINS ORIENTED FROM CENTRAL MO STRETCHING NORTHEAST THROUGH CENTRAL IL/IN AND DRIFTING SOUTHEAST. IR IMAGERY SHOWS THE AREA OF CLOUDS WELL...ASSOCIATED WITH THIS BAND OF PRECIP. THEN JUST WEST OF THIS FEATURE WAS YET ANOTHER WEAK MID- LVL WAVE THAT HAD ANOTHER AREA OF MID/UPR LVL MOISTURE ASSOCIATED WITH IT AND WAS SLIDING EAST...BEING STEERED BY THE SEMI-ZONAL FLOW IN THE MID-LVLS. TEMPS THIS MORNING WILL HOVER AROUND THE TEENS FOR THE BULK OF THE FORECAST AREA...PERHAPS HOLDING IN UPR TEENS/LOW 20S FOR THE SOUTHERN CWFA. OTHERWISE FOR TODAY HIGH PRESSURE WILL PUSH THIS AREA OF CLOUDS THIS MORNING TO THE SOUTH...AND ALLOW FOR A DRY DAY. SKIES WILL EVENTUALLY BECOME P-CLOUDY BY MIDDAY...WITH HIGHS WARMING MAINLY INTO THE 20S. CLOSER TO 30 FOR THE FAR SOUTHERN CWFA. THEN FOR TONIGHT...HIGH PRESSURE WILL CONTINUE TO HOLD ACROSS THE FORECAST AREA AND LIMIT CLOUD COVER. JUST NORTH OF THE AREA THOUGH...AND CLOSER TO A STRONGER MID-LVL VORT WILL BE THICKER CLOUD COVER. WINDS WILL GENERALLY REMAIN LIGHT FROM THE NORTHWEST...WHICH COUPLED WITH 850MB TEMPS HOVERING ARND -10 TO -12 DEG C SHOULD LIMIT HOW COOL TEMPS RADIATE OVERNIGHT. SO HAVE ONLY NUDGED TEMPS DOWN A LITTLE...GENERALLY IN THE SINGLE DIGITS ABOVE ZERO. COULD SEE SOME OF THE TRADITIONALLY COOLER LOCATIONS DIP TO ARND ZERO BY DAYBREAK MON. CONFIDENCE...HIGH. MONDAY THROUGH TUESDAY... 500MB TROUGH AXIS OVER THE GREAT LAKES REGION PUSHES EAST...WITH AN AREA OF WEAK RIDGING ARRIVING MIDDAY MON OVER THE FORECAST AREA. HOWEVER GIVEN THE SEMI-ZONAL FLOW...WHICH IS GENERALLY A MORE PROGRESSIVE SETUP...THE NEXT WAVE CONTINUES TO BE PROGGED FOR ARRIVAL MON LATE AFTN/EVE. LATEST FORECAST GUIDANCE HAS CONTINUED TO SUGGEST THE MID-LVL HEIGHT RISES MAY BE A LITTLE SLOWER TO DEPART THE REGION...WHICH WOULD LIKELY HAVE AN INFLUENCE ON THE WEAK WAVE ARRIVING POSSIBLY LATER. THE MAIN TIMING DOES APPEAR TO BE CONSISTENT WITH JUST AFT 00Z TUE...AND GIVEN THE PREV-DISCUSSED PROGRESSIVE FLOW...SKIES WILL THICKEN RATHER QUICKLY AND CIGS WILL LOWER WITH EASE. LOCAL MODEL INDICATES A SLIGHTLY LATER ARRIVAL AND CLOSER TO 6Z TUE...BUT ALSO IS INDICATING THE WAVE WILL BE WEAKENING UPON ARRIVAL. CONFIDENCE ON THIS WAVE WEAKENING AS IT ARRIVES IS VERY LOW...GIVEN THE DECENT MID-LVL FORCING ASSOCIATED. TEMPS CONTINUE TO BE COOL ENOUGH TO SUPPORT LGT SNOW FOR THE AREA...AND EXPECT SLR ARND 15:1 TO 18:1. THIS WILL LIKELY PRODUCE A QUICK 1 TO 2 INCHES OF SNOWFALL ACROSS MOST OF THE CWFA. BY 12-15Z TUE...THE BULK OF THE WAVE/SNOW WILL BE PUSHING EAST AND COMING TO AN END. THEN FOR TUE...500MB TROUGH AXIS ARRIVES AS AN ARCTIC AIRMASS CONTINUES TO PUSH SOUTH FROM CANADA TOWARDS THE UPPER MIDWEST TUE AFTN. CURRENTLY EXPECT HIGHS TUE TO HOLD IN THE TEENS/LOW 20S...HOWEVER BY TUE NGT THE BOUNDARY WILL BE PUSHING ACROSS THE FORECAST AREA AND TEMPS WILL BE DROPPING TO A FEW DEGREES BELOW ZERO. CONFIDENCE...HIGH. CONFIDENCE IN SNOW ACCUMS MON EVE/OVERNIGHT...HIGH. WEDNESDAY THROUGH SUNDAY... ENSEMBLES AND OPERATIONAL SOLUTIONS HAVE CONTINUED TO BE IN GOOD AGREEMENT WITH THE ARRIVAL OF YET ANOTHER ARCTIC AIRMASS. BY WED THE 500MB TROUGH AXIS WILL BE OVERHEAD. CURRENT PROGS INDICATE TEMPS IN MID-LVLS WILL HOVER ARND -20 TO -25 DEG C. WHEN APPLYING THIS TOWARDS LOCAL CLIMATE WHICH LIKELY YIELD HIGH TEMPS WED IN THE SINGLE DIGITS ABOVE ZERO TO POSSIBLY THE LOW TEENS. SFC RIDGE WILL BE SLIDING OVER THE AREA AS WELL...WHICH SHOULD LIMIT HOW MUCH LOWER WIND CHILL VALUES WILL BE WED. THEN FOR WED NGT...FLOW GRADUALLY TURNS WESTERLY IN THE LLVLS. A WEAK SHORTWAVE IS PROGGED TO CLIP THE NORTHERN GREAT LAKES REGION...HOWEVER EXPECT GENERALLY DRY WEATHER FOR THE FORECAST AREA WED/WED NGT. FOR THE REMAINDER OF THE EXTENDED PERIODS...ENSEMBLES REMAIN IN DECENT AGREEMENT WITH YET ANOTHER SFC RIDGE SLIDING SOUTHEAST FROM CENTRAL CANADA TOWARDS THE PLAINS AND STRETCHING EAST TO THE WESTERN GREAT LAKES THUR. THIS SHOULD HELP TO MAINTAIN UNSEASONABLY COLD CONDS FOR THE FORECAST AREA...WITH TEMPS STRUGGLING TO WARM BEYOND THE LOW/MID TEENS THUR AFTN. STRONG VORTEX BEGINS TO LIFT NORTHEAST THUR NGT/FRI...WITH SOME MODERATION TO TEMPS POISED FOR THE END OF THE WEEK INTO THE FIRST HALF OF NEXT WEEKEND. ALTHOUGH THIS IS RELATIVE...AS TEMPS WILL CONTINUE TO BE UNSEASONABLY COOL IN THE TEENS/LOW 20S. GUIDANCE IS SUGGESTING THE SOUTHERN STREAM WILL BECOME ACTIVE YET AGAIN IN THE LATER PERIODS...AND INDICATES THE PRECIP WILL REMAIN SOUTH OF THE CWFA. ALTHOUGH COULD SEE SOME ADJUSTMENTS TO THE PLACEMENT OF EACH SOUTHERN STREAM WAVE. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NONE //DISCUSSION...UPDATED 06Z... QUIET WEATHER DAY ON TAP THIS TAF PERIOD WITH VFR CONDITIONS AND WNW WINDS THROUGHOUT THE PERIOD. A FEW GUSTS INTO THE HIGH TEENS TO AROUND 20 KT ARE POSSIBLE DURING THE AFTERNOON AND EVENING SUNDAY...THEN SHOULD TAPER MID TO LATE IN THE EVENING. THE NEXT CHANCE FOR WEATHER IMPACTS APPEARS TO BE MONDAY NIGHT INTO TUESDAY WHEN SNOW WILL MOVE ACROSS THE AREA. //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH BMD //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...VFR LIKELY DURING DAYTIME THEN LIGHT SNOW BECOMING LIKELY MONDAY NIGHT WITH MVFR LIKELY...IFR POSSIBLE. TUESDAY...CHANCE OF LIGHT SNOW EARLY AM. THEN VFR LIKELY. WEDNESDAY THROUGH FRIDAY...VFR LIKELY. RC && .MARINE... 148 PM CST LOW PRESSURE CENTERED NEAR JAMES BAY THIS AFTERNOON CONTINUES TO PRODUCE WINDS OF 25 TO 30 KT ACROSS THE LAKE THIS AFTERNOON. THIS LOW WILL GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE WEEKEND. HOWEVER...WESTERLY WINDS WILL CONTINUE IN THE 20 TO 30 KT RANGE SUNDAY INTO MONDAY AS THE SURFACE GRADIENT REMAINS ELEVATED IN ADVANCE OF A BROAD RIDGE OF SURFACE HIGH PRESSURE EXTENDING FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. THE NEXT POTENTIAL HEADLINE WORTHY WIND EVENT WILL BE AROUND THE MIDDLE OF NEXT WEEK. A FEW CLIPPER TYPE SYSTEMS ARE EXPECTED TO DROP SOUTHEASTWARD ACROSS THE LAKES REGION DURING THIS PERIOD. OF THESE NUMEROUS CLIPPER SYSTEMS...IT APPEARS THAT A POTENT ONE WILL DROP ACROSS THE REGION WEDNESDAY NIGHT. THIS SYSTEM COULD PRODUCE A PERIOD OF SOUTHWESTERLY GALES ON WEDNESDAY...FOLLOWED BY A PERIOD OF POTENTIALLY HIGH END NORTHWESTERLY GALES IN ITS WAKE WEDNESDAY NIGHT INTO THURSDAY. WITH ANOTHER DEEP ARCTIC SURGE OF COLD AIR EXPECTED IN THE WAKE OF THIS SECOND CLIPPER...THERE WILL ALSO LIKELY BE SIGNIFICANT FREEZING SPRAY IN CONJUNCTION WITH THE STRONG NORTHWESTERLY GALES WEDNESDAY NIGHT INTO THURSDAY. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1140 PM CST Sat Feb 22 2014 .DISCUSSION... ISSUED 636 PM CST Sat Feb 22 2014 Made a few quick updates to the forecast to better reflect current trends, mainly to tighten the POP gradient across central Illinois. Radar continues to indicate the narrow band of precipitation remaining focused along a Jacksonville to Danville line. Latest run of the HRRR shows very little movement of the band until 04z when it slowly sinks southeastward. As a result, have increased POPs to categorical within the band itself and have removed all mention of POPs further north in the Peoria area and further south from Effingham southward. With surface temps in the middle to upper 30s initially, precip has started as rain at most sites, but is quickly transitioning to wet snow as evaporative cooling takes place within the surface-based layer. Based on gradual eastward shift of precip area and current temps above freezing, think snow accumulations will remain light. 1 to 2 inches still look reasonable across the E/NE KILX CWA, mainly from Decatur northeastward through Champaign to Danville, with little or no accumulation elsewhere around the area. Zone update has already been issued. Barnes && .AVIATION... ISSUED 1140 PM CST Sat Feb 22 2014 Persistent band of snow has now shifted southeast of the KILX terminals, so VFR conditions are expected through the entire 06z TAF period. Winds will remain northerly at less than 10kt tonight through Sunday afternoon before backing to northwesterly by evening. Only mid/upper-level clouds are expected as weak disturbances embedded within broad northwesterly flow aloft pass through the area over the next 24 hours. Barnes && .PREV DISCUSSION... ISSUED 300 PM CST Sat Feb 22 2014 Light snow or flurries will return this afternoon and this evening across most of the area. Measurable snow will be mainly confined to areas east of I-55, with an inch or two possible closer to Indiana east of Champaign to Mattoon. The next chance of snow beyond that appears to be late Monday and Monday night north of Lincoln to Champaign as the next shortwave moves across N IL. Dry conditions are expected the remainder of the forecast, with a dry cold frontal passage Wed night ushering in reinforcing cold air. Below normal temperatures will prevail for much of this 7-day forecast. SHORT TERM...Tonight through Monday. A band of mid-level frontogenesis north of the stationary front along I-70 will create some lift that will be enhanced by steep mid-level lapse rates. That should give the virga a boost in saturating the lower levels. Flurries already started at PIA around 2 pm after several hours of virga. Satellite pics show a baroclinic leaf developing ahead of the weak low pressure over western Missouri. That low is projected to slide east along the boundary, which should further enhance the thermo-dynamic forcing. Meso-scale bands of precip are being advertised by the HRRR and NMM-east. Light snow will be north of Mattoon to Paris with some rain or rain-snow mix south of there. We could see an inch or two of snow where the band of snow rotates and lingers across our east-central counties...bounded by a line from Decatur to Hoopeston in the north and Taylorville to Mattoon to Paris in the south. Even in this late hour, many differences exist with the placement and intensity of any meso-scale bands of precip late this afternoon and evening. The GFS and Canadian GEM are more aggressive with snow, while the NAM is the weakest and the ECMWF is in the middle. We increased PoPs to categorical and likely in areas with an inch or more snow possible, with high chance bordering that. Accums are a tough call with this much dry air to overcome, but forcing looks strong enough for a short duration to get some light accumulation. Precip should progress eastward after midnight, and come to an end for our counties by 3 am. Colder air will begin to advance into C IL with the surface high, which should help lows across the north drop into the teens. Clouds will temper the cool-down, as southern areas remain in the low 30s. The 12z Canadian has increased potential for snow or rn/sn as a shortwave advances east, just north of the stationary front. The ECMWF is also showing some forcing across our southern counties, but lower RH and no precip. After coord with offices to the south, we decided to just add sprinkles and flurries for now on Sunday. Mostly clear skies for much of Sunday night will provide better radiational cooling conditions, and lows will respond by dropping into the single digits north of Peoria. Monday afternoon and evening will see a 125kt jet at 250mb help push a shortwave across northern IL. Light snow will develop mainly north of a line from Rushville to Champaign...with a dusting along the line to as much as an inch from Galesburg to El Paso. The NAM is the main outlier with this period of snow, with much less forcing and farther south than the GFS/ECMWF/Canadian. We went with consensus and increased PoPs to likely across Knox to Woodford counties Monday eve. LONG TERM...Tuesday through Saturday. We are not expected any measurable precip through the extended forecast as colder air prevails. A dry cold frontal passage on Wed night will aid in keeping temps well below normal. Lows will dip below zero across our northern area on Tuesday night, and get very close to zero in the north Wed night and Thurs night. Highs will struggle to climb out of the teens north of I-72 on Wed. Gradual warming will develop from Thurs to Saturday, but even Saturday`s highs will range from mid 20s north to mid 30s south, or about 10 to 15 deg below normal. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1230 AM EST SUN FEB 23 2014 .SYNOPSIS... ISSUED AT 608 PM EST SAT FEB 22 2014 SNOW WILL BE POSSIBLE OVERNIGHT MAINLY NEAR AND SOUTH OF HIGHWAY 24. ANY MIXED PRECIPITATION WILL QUICKLY CHANGE OVER TO ALL SNOW THIS EVENING AS COOLER AIR FILTERS IN. IT WILL LIKELY REMAIN DRY TONIGHT OVER EXTREME NORTHERN INDIANA AND SOUTHWEST LOWER MICHIGAN. CANADIAN HIGH PRESSURE WILL BRING COOL AND DRY CONDITIONS ON SUNDAY. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 421 PM EST SAT FEB 22 2014 MODELS CONTINUE TO SHOW STRONG SIGNAL FOR NARROW...SHORT DURATION MESOSCALE SNOW THIS EVENING INTO THE OVERNIGHT HOURS. RELIED HEAVILY ON HIRES GUIDANCE GIVEN SMALL SCALE NATURE TO THIS EVENT. PREVIOUS SHIFT LOCKED ONTO EVENT AND ADJUSTMENTS MADE BASED ON LATEST HRRR...RAP13 AND 12Z ARW EAST AND ARW NMM. RESULT IS A LITTLE NORTHWARD ADJUST TO POPS AND SNOW BUT NOT BY MUCH. THE HIGHWAY 24 CORRIDOR AND SOUTH STILL APPEAR IN LINE FOR A GENERAL 1 TO 3 WITH SMALL EMBEDDED AREA OF 2 TO 5 WITH ANY MESOBANDING THAT SETS UP. STRONG MID LEVEL FORCING DEPICTED WITH OMEGA FIELDS IN THE 15 TO 20 UBAR/S RANGE. FGEN FORCING STILL IMPRESSIVE IN THIS SAME AREA WITH MESOBANDING POTENTIAL SEEN ON VERTICAL CROSS SECTIONS. HIRES GUIDANCE HAS BEEN PICKING UP ON THIS WITH SOME IMPRESSIVE LIFT AND QPF AMOUNTS THIS EVENING BETWEEN ONE QUARTER AND ONE HALF INCH NEAR AND SOUTH OF HIGHWAY 24. INITIAL CONCERNS WITH DRIER LOW LEVEL AIR AND MOISTURE GOING INTO SATURATION CONTINUE. LITTLE PCPN HAS BEEN NOTED THROUGH 19Z UPSTREAM WHERE SOME OF THE HIRES GUIDANCE HAS BEEN SHOWING UP TO A TENTH OF AN INCH LIQUID ALREADY. RADAR MOSAIC HAS SHOWN MID LEVEL RETURNS BUT FEW IF ANY SURFACE REPORTS. SATELLITE SHOWS COOLING CLOUD TOPS AND A SHORT WAVE APPROACHING. COUPLED JET STREAKS EXPECTED OVER AREA BY 00Z AND AS THESE FEATURES COME TOGETHER EXPECT PCPN TO BEGIN SATURATING AND REACHING GROUND. HAVE LEANED AWAY FROM THE HIGHER END QPF GIVEN POOR EARLY PERFORMANCE UPSTREAM AND FOCUSED MORE ON A BLEND OF THE MID RANGE VALUES. 16Z HRRR DEPICTION OF SNOW DEVELOPING FROM NEAR KLAF TO KFWA BY 23Z REASONABLE AND SIMILAR TO LATEST RAP13. BRIEF PERIOD OF RAIN AT ONSET POSSIBLE WITH LOW LEVEL THERMAL FIELDS ABOVE FREEZING. HOWEVER...EVAPORATIVE COOLING EXPECTED TO QUICKLY COOL VERY SHALLOW WARM LAYER AND QUICKLY TRANSITION TO ALL SNOW. DISCUSSION WITH WPC AGREED WITH A GENERAL 1 TO 2 INCHES AND SMALLER AREA OF 2 TO 4 POSSIBLE WITH EXACT LOCATION REMAINING A BIT UNCERTAIN GIVEN SMALL SCALE BUT INTENSE FORCING. WOULD NOT RULE OUT A FEW 5 INCH REPORTS BUT WOULD EXPECT THIS TO BE VERY ISOLATED IN A NARROW BAND. TIMING SUGGEST HEAVIEST SNOW BETWEEN ABOUT 00Z AND 05Z WITH QUICK ENDING FROM WEST TO EAST. EXPECT A RATHER SHARP GRADIENT ON NORTHERN PERIPHERY OF SNOW AND THIS WILL LIKELY NEED SOME ADJUSTMENT THIS EVENING ONCE SNOW DEVELOPS AND TRENDS ASSESSED. DRIER AND COOLER AIR MOVES IN LATE TONIGHT AND FOR SUNDAY. && .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 421 PM EST SAT FEB 22 2014 A DOMINANT UPSTREAM RIDGE WILL NOT START TO BREAK DOWN UNTIL LATE THIS WEEK ALLOWING FOR A VERY COLD UPCOMING PERIOD WITH FLOW COMING FROM THE CANADIAN INTERIOR. OVERALL...THE GFS AND ECMWF WERE STRUGGLING WITH RUN TO RUN CONSISTENCY IN HANDLING THE TIMING AND EXTEND OF SUCCESSIVE SURGES OF ARCTIC AIR...ESPECIALLY LATE THIS UPCOMING WEEK. HOWEVER...THE CANADIAN GEM AND ITS ENSEMBLES HAVE KEPT A VERY CONSISTENT SIGNAL FOR THE PAST SEVERAL RUNS HANDLING THE COLD AIR WITH THE ENSEMBLE MEDIAN STAYING 20 TO 25 DEGREES BELOW NORMAL FROM TUESDAY THROUGH SUNDAY. FOR THIS PACKAGE...GIVEN THIS VARIABILITY AMONG THE ECMWF AND GFS...BUT STRONG SIGNAL FROM THE CANADIAN GEM AND ANALOGS...KEPT TEMPERATURES COLD WITH VIRTUALLY NO CHANGES FROM THE PREVIOUS FORECAST FOR WEDNESDAY THROUGH THE END OF THE WEEK. THE ECMWF WAS COLDER AGAIN WITH THE 12Z RUN...WITH 850 MB TEMPS NEAR -27C SATURDAY. GIVEN THE CLIMATOLOGICAL EXTREMES OF THESE TEMPERATURES...KEPT HIGHS MAINLY IN THE TEENS WEDNESDAY THROUGH SATURDAY WITH LOWS IN THE SINGLE DIGITS ABOVE ZERO...TO A LITTLE BELOW ZERO THURSDAY NIGHT. THESE HIGHS AND LOWS ARE WELL IN LINE WITH THE LATEST CANADIAN GEM/EPS GRAMS. OTHERWISE...KEPT THE FORECAST DRY EXCEPT FOR A CHANCE FOR SNOW MONDAY NIGHT WITH THE ARRIVAL OF A WEAK UPPER LEVEL TROF. THE ECMWF...ALTHOUGH STRUGGLING LATE IN THE FORECAST PERIOD...HAS A GOOD HANDLE ON A WEAK UPSTREAM SHORTWAVE THAT SHOULD ARRIVE MONDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1230 AM EST SUN FEB 23 2014 ACTIVE FRONTAL BOUNDARY REMAINS JUST SOUTH OF KFWA AND LITTLE NORTHWARD MOVEMENT IS EXPECTED THROUGH THE REST OF THE NIGHT. IN FACT...RECENT RADAR RETURNS ARE BEGINNING TO WEAKEN AND EXPECT SNOWFALL TO CONTINUE WINDING DOWN OVER THE NEXT FEW HOURS AS PARENT JET FORCING LIFTS NORTHEAST. THEREFORE EXPECT VFR CONDITIONS TO CONTINUE THROUGH MUCH OF THE PERIOD AS CANADIAN RIDGE AXIS BUILDS INTO THE OHIO VALLEY. OUTSIDE CHANCE OF A FEW STRATOCU DURING THE DAY BUT DRY LOW LEVELS WILL BE DIFFICULT TO OVERCOME AND MAY BE ABLE TO REMOVE MENTION ALTOGETHER WITH THE 12Z ISSUANCE. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...KG SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
338 AM EST SUN FEB 23 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 410 PM EST SAT FEB 22 2014 THE LOW THAT BROUGHT THE SNOW AND MIXED PRECIPITATION TO THE AREA THURSDAY EVENING INTO FRIDAY HAS BECOME STATIONARY NEAR CAPE HENRIETTA MARIA BETWEEN HUDSON BAY AND JAMES BAY. THIS NEARLY STATIONARY LOW WILL COMBINE WITH A 1028MB HIGH PRESSURE RIDGE SLIDING SOUTHEAST FROM A HIGH IN THE CANADIAN ROCKIES AND INTO THE NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO CREATE A TIGHT PRESSURE GRADIENT OVER THE UPPER GREAT LAKES THROUGH TONIGHT AND PART OF SUNDAY. THUS...THE WINDS AND RESULTING BLOWING SNOW (MAINLY OVER THE KEWEENAW) WILL BE THE PRIMARY CONCERN FOR TONIGHT INTO SUNDAY. WITH THIS TIGHT PRESSURE GRADIENT REMAINING IN PLACE FOR MUCH OF THE NIGHT AND COLDER AIR ALOFT SPILLING INTO THE REGION...WOULD EXPECT THE GUSTY CONDITIONS TO REMAIN THROUGH AT LEAST THE FIRST HALF OF THE NIGHT. EVEN OVER THE LAST COUPLE OF HOURS...WINDS AT KCMX HAVE FALLEN TO ONLY 35-40MPH. UPSTREAM AT ISLE ROYALE...WINDS ARE STILL GUSTING TO SIMILAR VALUES AND WITH MODELS SHOWING GUSTS TO 35KTS THROUGH BETWEEN 06-12Z...WILL FOLLOW THAT IDEA FOR THE KEWEENAW TONIGHT. SINCE MUCH OF THE SNOW HAS DIMINISHED AT KCMX...SEEING MORE OF A SPOTTY NATURE TO THE WORST VISIBILITIES ON WEBCAMS AND THE KCMX OBS. THUS...THINKING THAT THE GOING ENDING TIME FOR THE BLIZZARD WARNING IS REASONABLE AND THE EVENING SHIFT WILL BE ABLE TO LET IT EXPIRE. THE QUESTION IS WHETHER A ADVISORY WILL BE NEEDED TO COVER THE LINGERING BLOWING/DRIFTING SNOW OR IF IT COULD BE COVERED BY AN SPS. ALMOST LEANING TOWARDS AN SPS...BUT WILL ALLOW EVENING SHIFT TO SEE HOW VISIBILITIES ARE DOING OVER THE NEXT FEW HOURS AND THEN DECIDE. WITH THE CLEARING SKIES AND LITTLE VSBY RESTRICTIONS ON WEBCAMS IN GOGEBIC/ONTONAGON COUNTIES...HAVE CANCELLED THE EXISTING WINTER WX ADVISORY FOR THERE. OVER THE REST OF THE AREA...A SHORTWAVE THAT WAS OVER WESTERN ONTARIO THIS MORNING HAS SHIFTED EAST-SOUTHEAST AND IS MOVING ACROSS FAR NORTHERN LAKE SUPERIOR. WITH THIS TRACK...IT LOOKS LIKE THE DEEPER MOISTURE WILL HOLD OFF MOVING SOUTH OVER THE CWA UNTIL LATE TONIGHT AND ESPECIALLY INTO SUNDAY AFTERNOON. THUS...THINK MUCH OF THE CLOUDS AND SNOW CHANCES FOR MUCH OF THE SHORT TERM PERIOD WILL DEPEND ON LAKE EFFECT. WITH RAP ANALYZED 850MB TEMPS AROUND -17C AND MODELS SHOWING THAT FALLING TO -23C BY 00Z MONDAY...THERE IS PLENTY OF OVER LAKE INSTABILITY IF WATER IS PRESENT ON LAKE SUPERIOR. TODAY/S MODIS IMAGE SHOWS SOME OPEN WATER THAT HAS DEVELOPED OFF THE ARROWHEAD OF MINNESOTA AND ALSO TO THE EAST OF THE KEWEENAW. THEREFORE...WITH THE WESTERLY 925MB WINDS EXPECTED TONIGHT...HAVE FOCUSED CLOUD COVER AND SLIGHT TO LOW CHANCE POPS IN THE AREAS DOWNWIND OF THOSE PATCHES OF OPEN WATER. THIS MAINLY AFFECTS THE KEWEENAW PENINSULA. WITH WINDS SHIFTING A LITTLE MORE TO THE NORTHWEST ON SUNDAY AFTERNOON...HAVE SLOWLY TRANSITIONED POPS TOWARDS THAT DIRECTION. DIDN/T PUT MUCH FOR SNOWFALL AMOUNTS (ONLY AROUND AN INCH OR SO) INTO THE FORECAST DUE TO THE STRENGTH OF THE WINDS LIKELY LIMITING FETCH ACROSS THE OPEN WATER. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 338 AM EST SUN FEB 23 2014 BIGGEST ISSUES IN THE LONG TERM ARE WITH THE RETURN OF EXTREMELY COLD AIR AND LIGHT-MODERATE LES. FOR LES CONSIDERATIONS...SOME BREAK UP OF LAKE SUPERIOR ICE HAS OCCURRED OVER THE LAST COUPLE OF DAYS WITH THE STRONG WLY WINDS. THIS WILL ALLOW FOR INCREASED LES ACTIVITY OVER THE NEXT WEEK. MON WILL SEE DIMINISHING NW FLOW LES POPS AS A RIDGE PASSES OVERHEAD AND 850MB TEMPS DECREASE FROM THE MID 20S TO MID TEENS BELOW ZERO. WILL SEE SEVERAL PIECES OF ENERGY MOVING THROUGH THE REGION OVER THE NEXT WEEK...EACH ONE PULLING DOWN MORE COLD AIR UNTIL A POLAR LOW MOVES TO NEAR JAMES BAY BY 12Z THU. 850MB TEMPS AOB -30C MOVE INTO THE AREA THU NIGHT INTO THE WEEKEND. THIS WILL LEAD TO VERY COLD TEMPERATURES YET AGAIN. THU LOOKS TO SEE THE COLDEST HIGH TEMPS IN THE SINGLE DIGITS AND TUE NIGHT SHOULD BE COLDEST. WILL LIKELY BREAK RECORD LOW HIGH TEMPERATURES THIS WEEK...AND POSSIBLY SOME DAILY RECORD LOWS. SOME LIGHT TO MODERATE SNOWFALL IS POSSIBLE AT TIMES THROUGH THE NEXT WEEK...BUT GREATER OF THE CONFIDENCE VERY UNCERTAIN SO DID NOT MAKE SIGNIFICANT CHANGES TO THE PREVIOUS FORECAST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1152 PM EST SAT FEB 22 2014 WITH WEAKENING LOW PRES REMAINING IN THE VCNTY OF FAR NRN ONTARIO/JAMES BAY AND HIGH PRES CONTINUING TO RIDGE SE FROM THE SRN CANADIAN ROCKIES TO THE MID MISSISSIPPI VALLEY...BLUSTERY WESTERLY WINDS WILL CONTINUE FOR MUCH OF THIS FCST PERIOD AT KIWD/KCMX/KSAW...BUT ESPECIALLY AT THE MORE EXPOSED KCMX SITE. WITH WINDS GUSTING OVER 30KT AT KCMX OVERNIGHT THRU THE AFTN...BLSN WILL LIKELY KEEP PREVAILING VIS IN THE LIFR CATEGORY. EXPECT SOME FLUCTUATION WITH VIS IMPROVING TO IFR FOR BRIEF PERIODS AS WELL AS FALLING TO VLIFR. WITH THE WESTERLY WINDS AND SOME GAPS IN THE ICE OVER WESTERN LAKE SUPERIOR...THERE WILL BE OCNL -SHSN AT KCMX...WHICH WILL ASSIST THE LOWER VISIBILITIES. DISTURBANCE SHOULD INCREASE -SHSN FREQUENCY TODAY...AND THIS MAY RESULT IN VIS FALLING MORE FREQUENTLY TO BLO 1/2SM. THERE SHOULD BE SOME IMPROVEMENT TO IFR THIS EVENING AS WINDS VEER MORE TO THE NW AND DIMINISH SOME... RESULTING IN LESS BLSN. AT KIWD/KSAW...SRN EDGE OF STRATOCU/MVFR CIGS WILL BE NEAR KIWD OVERNIGHT WHILE DOWNSLOPE WESTERLY WINDS WILL HELP TO MAINTAIN VFR CONDITIONS AT KSAW. DEEPER MOISTURE/DISTURBANCE ROTATING INTO THE AREA DURING THE DAY TODAY SHOULD PRODUCE A MORE SOLID MVFR CLOUD DECK AS WELL AS SOME -SHSN/FLURRIES. AFTER THE STRONG WINDS OF RECENT DAYS...THERE MAY BE SUFFICIENT OPEN WATER OVER WRN LAKE SUPERIOR TO SUPPORT IFR CONDITIONS IN -SHSN AT KIWD THIS EVENING AS WINDS VEER MORE TO THE NW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 334 AM EST SUN FEB 23 2014 LOW PRESSURE OVER JAMES BAY TODAY WILL EXIT INTO QUEBEC TONIGHT. EXPECT HIGH PRESSURE ACROSS SASKATCHEWAN TODAY TO SINK ACROSS THE PLAINS STATES TUESDAY NIGHT INTO WEDNESDAY...ALLOWING A RIDGE TO PASS OVER LAKE SUPERIOR TUESDAY AND TUESDAY NIGHT. W GALES 35-40KTS WILL CONTINUE TODAY OVER PORTIONS OF MAINLY CENTRAL AND E LAKE SUPERIOR IN BETWEEN THE EXITING LOW...AND NEARING HIGH PRESSURE FROM THE NW. LOW PRESSURE OVER NW MANITOBA WEDNESDAY MORNING WILL SWING ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON AND EVENING BEFORE EXITING TO THE NEW ENGLAND STATES. HIGH PRESSURE OVER CENTRAL CANADA AND ND THURSDAY MORNING WILL BROADEN ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ001- 003. LAKE SUPERIOR... GALE WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR LSZ240>246-263>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...TITUS AVIATION...ROLFSON MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
335 AM EST SUN FEB 23 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 410 PM EST SAT FEB 22 2014 THE LOW THAT BROUGHT THE SNOW AND MIXED PRECIPITATION TO THE AREA THURSDAY EVENING INTO FRIDAY HAS BECOME STATIONARY NEAR CAPE HENRIETTA MARIA BETWEEN HUDSON BAY AND JAMES BAY. THIS NEARLY STATIONARY LOW WILL COMBINE WITH A 1028MB HIGH PRESSURE RIDGE SLIDING SOUTHEAST FROM A HIGH IN THE CANADIAN ROCKIES AND INTO THE NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO CREATE A TIGHT PRESSURE GRADIENT OVER THE UPPER GREAT LAKES THROUGH TONIGHT AND PART OF SUNDAY. THUS...THE WINDS AND RESULTING BLOWING SNOW (MAINLY OVER THE KEWEENAW) WILL BE THE PRIMARY CONCERN FOR TONIGHT INTO SUNDAY. WITH THIS TIGHT PRESSURE GRADIENT REMAINING IN PLACE FOR MUCH OF THE NIGHT AND COLDER AIR ALOFT SPILLING INTO THE REGION...WOULD EXPECT THE GUSTY CONDITIONS TO REMAIN THROUGH AT LEAST THE FIRST HALF OF THE NIGHT. EVEN OVER THE LAST COUPLE OF HOURS...WINDS AT KCMX HAVE FALLEN TO ONLY 35-40MPH. UPSTREAM AT ISLE ROYALE...WINDS ARE STILL GUSTING TO SIMILAR VALUES AND WITH MODELS SHOWING GUSTS TO 35KTS THROUGH BETWEEN 06-12Z...WILL FOLLOW THAT IDEA FOR THE KEWEENAW TONIGHT. SINCE MUCH OF THE SNOW HAS DIMINISHED AT KCMX...SEEING MORE OF A SPOTTY NATURE TO THE WORST VISIBILITIES ON WEBCAMS AND THE KCMX OBS. THUS...THINKING THAT THE GOING ENDING TIME FOR THE BLIZZARD WARNING IS REASONABLE AND THE EVENING SHIFT WILL BE ABLE TO LET IT EXPIRE. THE QUESTION IS WHETHER A ADVISORY WILL BE NEEDED TO COVER THE LINGERING BLOWING/DRIFTING SNOW OR IF IT COULD BE COVERED BY AN SPS. ALMOST LEANING TOWARDS AN SPS...BUT WILL ALLOW EVENING SHIFT TO SEE HOW VISIBILITIES ARE DOING OVER THE NEXT FEW HOURS AND THEN DECIDE. WITH THE CLEARING SKIES AND LITTLE VSBY RESTRICTIONS ON WEBCAMS IN GOGEBIC/ONTONAGON COUNTIES...HAVE CANCELLED THE EXISTING WINTER WX ADVISORY FOR THERE. OVER THE REST OF THE AREA...A SHORTWAVE THAT WAS OVER WESTERN ONTARIO THIS MORNING HAS SHIFTED EAST-SOUTHEAST AND IS MOVING ACROSS FAR NORTHERN LAKE SUPERIOR. WITH THIS TRACK...IT LOOKS LIKE THE DEEPER MOISTURE WILL HOLD OFF MOVING SOUTH OVER THE CWA UNTIL LATE TONIGHT AND ESPECIALLY INTO SUNDAY AFTERNOON. THUS...THINK MUCH OF THE CLOUDS AND SNOW CHANCES FOR MUCH OF THE SHORT TERM PERIOD WILL DEPEND ON LAKE EFFECT. WITH RAP ANALYZED 850MB TEMPS AROUND -17C AND MODELS SHOWING THAT FALLING TO -23C BY 00Z MONDAY...THERE IS PLENTY OF OVER LAKE INSTABILITY IF WATER IS PRESENT ON LAKE SUPERIOR. TODAY/S MODIS IMAGE SHOWS SOME OPEN WATER THAT HAS DEVELOPED OFF THE ARROWHEAD OF MINNESOTA AND ALSO TO THE EAST OF THE KEWEENAW. THEREFORE...WITH THE WESTERLY 925MB WINDS EXPECTED TONIGHT...HAVE FOCUSED CLOUD COVER AND SLIGHT TO LOW CHANCE POPS IN THE AREAS DOWNWIND OF THOSE PATCHES OF OPEN WATER. THIS MAINLY AFFECTS THE KEWEENAW PENINSULA. WITH WINDS SHIFTING A LITTLE MORE TO THE NORTHWEST ON SUNDAY AFTERNOON...HAVE SLOWLY TRANSITIONED POPS TOWARDS THAT DIRECTION. DIDN/T PUT MUCH FOR SNOWFALL AMOUNTS (ONLY AROUND AN INCH OR SO) INTO THE FORECAST DUE TO THE STRENGTH OF THE WINDS LIKELY LIMITING FETCH ACROSS THE OPEN WATER. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 410 PM EST SAT FEB 22 2014 NO MAJOR CHANGES EXPECTED TO THE LONG TERM FORECAST WITH MUCH BELOW NORMAL TEMPERATURES AND OCCASIONAL LIGHT SNOW CLOSE TO LAKE SUPERIOR. WITH THE ARCTIC AIRMASS ONCE AGAIN BUILDING ACROSS HUDSON BAY...THE COLDEST TEMPERATURES STILL LOOK TO BE WED-FRI WITH TEMPS STRUGGLING TO RISE ABOVE ZERO ONCE AGAIN. AS FOR THE DETAILS...THE DEEP LOW PRESSURE OVER JAMES BAY WILL CONTINUE TO FILL SUNDAY NIGHT THEN FINALLY MOVE EAST BY MONDAY IN RESPONSE TO A UPPER SHORT WAVE ROTATING AROUND THE UPPER LOW AND THROUGH THE REGION. THIS WILL ALLOW PBL WINDS TO VEER TO THE NW SUNDAY NIGHT. THIS VEERING OF WIND COMBINED WITH WEAK UPWARD MOTION ASSOCIATED WITH THE UPPER SHORT WAVE AND DEEPER MOISTURE SHOULD ALLOW FOR SOME LAKE EFFECT SNOW TO SPREAD A LITTLE FURTHER WEST PERHAPS TO THE ALGER/MARQUETTE COUNTY BORDER. IN ADDITION...LES SHOULD INCREASE ACROSS THE ENTIRE AREA NEAR LAKE SUPERIOR BUT THIS IS HIGHLY DEPENDENT ON THE FLUXES OVER THE SEMI-OPEN AREAS OF LAKE SUPERIOR. ONE WOULD THINK THAT WITH THE WIND OVER THE PAST FEW DAYS THAT THE ICE ON THE LAKE HAS BROKEN UP SOME. IN FACT...TODAY/S MODIS IMAGERY INDICATES THAT SEVERAL LARGER BREAKS HAVE OPENED ACROSS THE WESTERN LAKE AS WELL AS EAST OF THE KEWEENAW. IN FACT...WOULD NOT BE SHOCKED TO SEE A LITTLE MINI BAND OF ENHANCED LES JUST EAST OF THE KEWEENAW ORIENTED INTO FAR WESTERN ALGER COUNTY...ESPECIALLY IF WE CAN SEE ENHANCED LAKE BREEZE CONVERGENCE AS THE WINDS VEER TO NW. FOR NOW...WILL RAISE POPS TO 50 PCT ACROSS ALL OF ALGER INTO LUCE COUNTIES AND RAISE POPS TO CHC CATEGORY IN ERN MQT COUNTY. BEHIND THIS SHORT WAVE...LIGHT LES WILL CONTINUE IN THE KEWEENAW AND INTO ALGER/LUCE COUNTIES WITH NORTHWESTERLY CYCLONIC FLOW. ONCE AGAIN...IT IS STILL UNCLEAR IF FLUXES WILL INCREASE ENOUGH TO GENERATE LES OFF THE LAKE. AS SUCH...WILL CONTINUE WITH JUST CHANCE POPS. WINDS BACK TO WNW TUE AHEAD OF A WEAK SFC TROUGH...WHICH SHOULD ALLOW ANY LES TO SHIFT OFFSHORE EXCEPT FOR THE KEWEENAW. THE EXTENDED PERIOD...WED-SAT...CONTINUES TO LOOK EXTREMELY COLD. THE 12Z NWP CONTINUES TO BE IN VERY GOOD AGREEMENT IN SHOWING THE ARCTIC FRONT MOVING THROUGH THE UPPER GREAT LAKES WED NIGHT INTO THU MORNING...OPENING THE DOOR FOR ARCTIC AIR TO MOVE ACROSS THE REGION. MODELS STILL SHOW 850MB TEMPS DROPPING TO -30 TO -34C BY THU EVENING WHICH WILL CAUSE TEMPS TO STRUGGLE TO RISE ABOVE ZERO DURING THE DAY. SFC HIGH PRESSURE IS FCST TO QUICKLY BUILD ACROSS THE AREA THU NIGHT WHICH SHOULD ALLOW FOR EXCELLENT RADIATIVE COOLING...THUS DROPPING SFC TEMPS TO -20F OR LOWER. IF THE SKIES CLEAR AND WINDS GO LIGHT...THIS COULD BE ONE OF THOSE SITUATIONS SIMILAR TO EARLY MARCH 2003 WHERE NWS MQT SAW A MIN TEMP OF -31F. FOR NOW...WILL GO WITH LOWS FRIDAY MORNING -20 TO -25 BELOW. PERHAPS SOME MODERATION IN TEMPS BY SATURDAY WITH SLIGHT 850MB WARMING...BUT THE WINDS WILL ALSO BE INCREASING AS THE ARCTIC HIGH STRENGTHENS LEADING TO A TIGHTENING PRES GRADIENT ACROSS THE AREA. AS SUCH...APPARENT TEMPS WILL NOT FEEL MUCH DIFFERENT INTO THE WEEKEND. JUST TO NOTE...THE LATEST CFS /CLIMATE FORECAST SYSTEM/ GUIDANCE SHOWS MUCH OF MARCH WITH BELOW NORMAL TEMPERATURES... && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1152 PM EST SAT FEB 22 2014 WITH WEAKENING LOW PRES REMAINING IN THE VCNTY OF FAR NRN ONTARIO/JAMES BAY AND HIGH PRES CONTINUING TO RIDGE SE FROM THE SRN CANADIAN ROCKIES TO THE MID MISSISSIPPI VALLEY...BLUSTERY WESTERLY WINDS WILL CONTINUE FOR MUCH OF THIS FCST PERIOD AT KIWD/KCMX/KSAW...BUT ESPECIALLY AT THE MORE EXPOSED KCMX SITE. WITH WINDS GUSTING OVER 30KT AT KCMX OVERNIGHT THRU THE AFTN...BLSN WILL LIKELY KEEP PREVAILING VIS IN THE LIFR CATEGORY. EXPECT SOME FLUCTUATION WITH VIS IMPROVING TO IFR FOR BRIEF PERIODS AS WELL AS FALLING TO VLIFR. WITH THE WESTERLY WINDS AND SOME GAPS IN THE ICE OVER WESTERN LAKE SUPERIOR...THERE WILL BE OCNL -SHSN AT KCMX...WHICH WILL ASSIST THE LOWER VISIBILITIES. DISTURBANCE SHOULD INCREASE -SHSN FREQUENCY TODAY...AND THIS MAY RESULT IN VIS FALLING MORE FREQUENTLY TO BLO 1/2SM. THERE SHOULD BE SOME IMPROVEMENT TO IFR THIS EVENING AS WINDS VEER MORE TO THE NW AND DIMINISH SOME... RESULTING IN LESS BLSN. AT KIWD/KSAW...SRN EDGE OF STRATOCU/MVFR CIGS WILL BE NEAR KIWD OVERNIGHT WHILE DOWNSLOPE WESTERLY WINDS WILL HELP TO MAINTAIN VFR CONDITIONS AT KSAW. DEEPER MOISTURE/DISTURBANCE ROTATING INTO THE AREA DURING THE DAY TODAY SHOULD PRODUCE A MORE SOLID MVFR CLOUD DECK AS WELL AS SOME -SHSN/FLURRIES. AFTER THE STRONG WINDS OF RECENT DAYS...THERE MAY BE SUFFICIENT OPEN WATER OVER WRN LAKE SUPERIOR TO SUPPORT IFR CONDITIONS IN -SHSN AT KIWD THIS EVENING AS WINDS VEER MORE TO THE NW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 334 AM EST SUN FEB 23 2014 LOW PRESSURE OVER JAMES BAY TODAY WILL EXIT INTO QUEBEC TONIGHT. EXPECT HIGH PRESSURE ACROSS SASKATCHEWAN TODAY TO SINK ACROSS THE PLAINS STATES TUESDAY NIGHT INTO WEDNESDAY...ALLOWING A RIDGE TO PASS OVER LAKE SUPERIOR TUESDAY AND TUESDAY NIGHT. W GALES 35-40KTS WILL CONTINUE TODAY OVER PORTIONS OF MAINLY CENTRAL AND E LAKE SUPERIOR IN BETWEEN THE EXITING LOW...AND NEARING HIGH PRESSURE FROM THE NW. LOW PRESSURE OVER NW MANITOBA WEDNESDAY MORNING WILL SWING ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON AND EVENING BEFORE EXITING TO THE NEW ENGLAND STATES. HIGH PRESSURE OVER CENTRAL CANADA AND ND THURSDAY MORNING WILL BROADEN ACROSS THE UPPER GREAT LAKES THURSDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ001- 003. LAKE SUPERIOR... GALE WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR LSZ240>246-263>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...MRD AVIATION...ROLFSON MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1153 PM EST SAT FEB 22 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 410 PM EST SAT FEB 22 2014 THE LOW THAT BROUGHT THE SNOW AND MIXED PRECIPITATION TO THE AREA THURSDAY EVENING INTO FRIDAY HAS BECOME STATIONARY NEAR CAPE HENRIETTA MARIA BETWEEN HUDSON BAY AND JAMES BAY. THIS NEARLY STATIONARY LOW WILL COMBINE WITH A 1028MB HIGH PRESSURE RIDGE SLIDING SOUTHEAST FROM A HIGH IN THE CANADIAN ROCKIES AND INTO THE NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO CREATE A TIGHT PRESSURE GRADIENT OVER THE UPPER GREAT LAKES THROUGH TONIGHT AND PART OF SUNDAY. THUS...THE WINDS AND RESULTING BLOWING SNOW (MAINLY OVER THE KEWEENAW) WILL BE THE PRIMARY CONCERN FOR TONIGHT INTO SUNDAY. WITH THIS TIGHT PRESSURE GRADIENT REMAINING IN PLACE FOR MUCH OF THE NIGHT AND COLDER AIR ALOFT SPILLING INTO THE REGION...WOULD EXPECT THE GUSTY CONDITIONS TO REMAIN THROUGH AT LEAST THE FIRST HALF OF THE NIGHT. EVEN OVER THE LAST COUPLE OF HOURS...WINDS AT KCMX HAVE FALLEN TO ONLY 35-40MPH. UPSTREAM AT ISLE ROYALE...WINDS ARE STILL GUSTING TO SIMILAR VALUES AND WITH MODELS SHOWING GUSTS TO 35KTS THROUGH BETWEEN 06-12Z...WILL FOLLOW THAT IDEA FOR THE KEWEENAW TONIGHT. SINCE MUCH OF THE SNOW HAS DIMINISHED AT KCMX...SEEING MORE OF A SPOTTY NATURE TO THE WORST VISIBILITIES ON WEBCAMS AND THE KCMX OBS. THUS...THINKING THAT THE GOING ENDING TIME FOR THE BLIZZARD WARNING IS REASONABLE AND THE EVENING SHIFT WILL BE ABLE TO LET IT EXPIRE. THE QUESTION IS WHETHER A ADVISORY WILL BE NEEDED TO COVER THE LINGERING BLOWING/DRIFTING SNOW OR IF IT COULD BE COVERED BY AN SPS. ALMOST LEANING TOWARDS AN SPS...BUT WILL ALLOW EVENING SHIFT TO SEE HOW VISIBILITIES ARE DOING OVER THE NEXT FEW HOURS AND THEN DECIDE. WITH THE CLEARING SKIES AND LITTLE VSBY RESTRICTIONS ON WEBCAMS IN GOGEBIC/ONTONAGON COUNTIES...HAVE CANCELLED THE EXISTING WINTER WX ADVISORY FOR THERE. OVER THE REST OF THE AREA...A SHORTWAVE THAT WAS OVER WESTERN ONTARIO THIS MORNING HAS SHIFTED EAST-SOUTHEAST AND IS MOVING ACROSS FAR NORTHERN LAKE SUPERIOR. WITH THIS TRACK...IT LOOKS LIKE THE DEEPER MOISTURE WILL HOLD OFF MOVING SOUTH OVER THE CWA UNTIL LATE TONIGHT AND ESPECIALLY INTO SUNDAY AFTERNOON. THUS...THINK MUCH OF THE CLOUDS AND SNOW CHANCES FOR MUCH OF THE SHORT TERM PERIOD WILL DEPEND ON LAKE EFFECT. WITH RAP ANALYZED 850MB TEMPS AROUND -17C AND MODELS SHOWING THAT FALLING TO -23C BY 00Z MONDAY...THERE IS PLENTY OF OVER LAKE INSTABILITY IF WATER IS PRESENT ON LAKE SUPERIOR. TODAY/S MODIS IMAGE SHOWS SOME OPEN WATER THAT HAS DEVELOPED OFF THE ARROWHEAD OF MINNESOTA AND ALSO TO THE EAST OF THE KEWEENAW. THEREFORE...WITH THE WESTERLY 925MB WINDS EXPECTED TONIGHT...HAVE FOCUSED CLOUD COVER AND SLIGHT TO LOW CHANCE POPS IN THE AREAS DOWNWIND OF THOSE PATCHES OF OPEN WATER. THIS MAINLY AFFECTS THE KEWEENAW PENINSULA. WITH WINDS SHIFTING A LITTLE MORE TO THE NORTHWEST ON SUNDAY AFTERNOON...HAVE SLOWLY TRANSITIONED POPS TOWARDS THAT DIRECTION. DIDN/T PUT MUCH FOR SNOWFALL AMOUNTS (ONLY AROUND AN INCH OR SO) INTO THE FORECAST DUE TO THE STRENGTH OF THE WINDS LIKELY LIMITING FETCH ACROSS THE OPEN WATER. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 410 PM EST SAT FEB 22 2014 NO MAJOR CHANGES EXPECTED TO THE LONG TERM FORECAST WITH MUCH BELOW NORMAL TEMPERATURES AND OCCASIONAL LIGHT SNOW CLOSE TO LAKE SUPERIOR. WITH THE ARCTIC AIRMASS ONCE AGAIN BUILDING ACROSS HUDSON BAY...THE COLDEST TEMPERATURES STILL LOOK TO BE WED-FRI WITH TEMPS STRUGGLING TO RISE ABOVE ZERO ONCE AGAIN. AS FOR THE DETAILS...THE DEEP LOW PRESSURE OVER JAMES BAY WILL CONTINUE TO FILL SUNDAY NIGHT THEN FINALLY MOVE EAST BY MONDAY IN RESPONSE TO A UPPER SHORT WAVE ROTATING AROUND THE UPPER LOW AND THROUGH THE REGION. THIS WILL ALLOW PBL WINDS TO VEER TO THE NW SUNDAY NIGHT. THIS VEERING OF WIND COMBINED WITH WEAK UPWARD MOTION ASSOCIATED WITH THE UPPER SHORT WAVE AND DEEPER MOISTURE SHOULD ALLOW FOR SOME LAKE EFFECT SNOW TO SPREAD A LITTLE FURTHER WEST PERHAPS TO THE ALGER/MARQUETTE COUNTY BORDER. IN ADDITION...LES SHOULD INCREASE ACROSS THE ENTIRE AREA NEAR LAKE SUPERIOR BUT THIS IS HIGHLY DEPENDENT ON THE FLUXES OVER THE SEMI-OPEN AREAS OF LAKE SUPERIOR. ONE WOULD THINK THAT WITH THE WIND OVER THE PAST FEW DAYS THAT THE ICE ON THE LAKE HAS BROKEN UP SOME. IN FACT...TODAY/S MODIS IMAGERY INDICATES THAT SEVERAL LARGER BREAKS HAVE OPENED ACROSS THE WESTERN LAKE AS WELL AS EAST OF THE KEWEENAW. IN FACT...WOULD NOT BE SHOCKED TO SEE A LITTLE MINI BAND OF ENHANCED LES JUST EAST OF THE KEWEENAW ORIENTED INTO FAR WESTERN ALGER COUNTY...ESPECIALLY IF WE CAN SEE ENHANCED LAKE BREEZE CONVERGENCE AS THE WINDS VEER TO NW. FOR NOW...WILL RAISE POPS TO 50 PCT ACROSS ALL OF ALGER INTO LUCE COUNTIES AND RAISE POPS TO CHC CATEGORY IN ERN MQT COUNTY. BEHIND THIS SHORT WAVE...LIGHT LES WILL CONTINUE IN THE KEWEENAW AND INTO ALGER/LUCE COUNTIES WITH NORTHWESTERLY CYCLONIC FLOW. ONCE AGAIN...IT IS STILL UNCLEAR IF FLUXES WILL INCREASE ENOUGH TO GENERATE LES OFF THE LAKE. AS SUCH...WILL CONTINUE WITH JUST CHANCE POPS. WINDS BACK TO WNW TUE AHEAD OF A WEAK SFC TROUGH...WHICH SHOULD ALLOW ANY LES TO SHIFT OFFSHORE EXCEPT FOR THE KEWEENAW. THE EXTENDED PERIOD...WED-SAT...CONTINUES TO LOOK EXTREMELY COLD. THE 12Z NWP CONTINUES TO BE IN VERY GOOD AGREEMENT IN SHOWING THE ARCTIC FRONT MOVING THROUGH THE UPPER GREAT LAKES WED NIGHT INTO THU MORNING...OPENING THE DOOR FOR ARCTIC AIR TO MOVE ACROSS THE REGION. MODELS STILL SHOW 850MB TEMPS DROPPING TO -30 TO -34C BY THU EVENING WHICH WILL CAUSE TEMPS TO STRUGGLE TO RISE ABOVE ZERO DURING THE DAY. SFC HIGH PRESSURE IS FCST TO QUICKLY BUILD ACROSS THE AREA THU NIGHT WHICH SHOULD ALLOW FOR EXCELLENT RADIATIVE COOLING...THUS DROPPING SFC TEMPS TO -20F OR LOWER. IF THE SKIES CLEAR AND WINDS GO LIGHT...THIS COULD BE ONE OF THOSE SITUATIONS SIMILAR TO EARLY MARCH 2003 WHERE NWS MQT SAW A MIN TEMP OF -31F. FOR NOW...WILL GO WITH LOWS FRIDAY MORNING -20 TO -25 BELOW. PERHAPS SOME MODERATION IN TEMPS BY SATURDAY WITH SLIGHT 850MB WARMING...BUT THE WINDS WILL ALSO BE INCREASING AS THE ARCTIC HIGH STRENGTHENS LEADING TO A TIGHTENING PRES GRADIENT ACROSS THE AREA. AS SUCH...APPARENT TEMPS WILL NOT FEEL MUCH DIFFERENT INTO THE WEEKEND. JUST TO NOTE...THE LATEST CFS /CLIMATE FORECAST SYSTEM/ GUIDANCE SHOWS MUCH OF MARCH WITH BELOW NORMAL TEMPERATURES... && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1152 PM EST SAT FEB 22 2014 WITH WEAKENING LOW PRES REMAINING IN THE VCNTY OF FAR NRN ONTARIO/JAMES BAY AND HIGH PRES CONTINUING TO RIDGE SE FROM THE SRN CANADIAN ROCKIES TO THE MID MISSISSIPPI VALLEY...BLUSTERY WESTERLY WINDS WILL CONTINUE FOR MUCH OF THIS FCST PERIOD AT KIWD/KCMX/KSAW...BUT ESPECIALLY AT THE MORE EXPOSED KCMX SITE. WITH WINDS GUSTING OVER 30KT AT KCMX OVERNIGHT THRU THE AFTN...BLSN WILL LIKELY KEEP PREVAILING VIS IN THE LIFR CATEGORY. EXPECT SOME FLUCTUATION WITH VIS IMPROVING TO IFR FOR BRIEF PERIODS AS WELL AS FALLING TO VLIFR. WITH THE WESTERLY WINDS AND SOME GAPS IN THE ICE OVER WESTERN LAKE SUPERIOR...THERE WILL BE OCNL -SHSN AT KCMX...WHICH WILL ASSIST THE LOWER VISIBILITIES. DISTURBANCE SHOULD INCREASE -SHSN FREQUENCY TODAY...AND THIS MAY RESULT IN VIS FALLING MORE FREQUENTLY TO BLO 1/2SM. THERE SHOULD BE SOME IMPROVEMENT TO IFR THIS EVENING AS WINDS VEER MORE TO THE NW AND DIMINISH SOME... RESULTING IN LESS BLSN. AT KIWD/KSAW...SRN EDGE OF STRATOCU/MVFR CIGS WILL BE NEAR KIWD OVERNIGHT WHILE DOWNSLOPE WESTERLY WINDS WILL HELP TO MAINTAIN VFR CONDITIONS AT KSAW. DEEPER MOISTURE/DISTURBANCE ROTATING INTO THE AREA DURING THE DAY TODAY SHOULD PRODUCE A MORE SOLID MVFR CLOUD DECK AS WELL AS SOME -SHSN/FLURRIES. AFTER THE STRONG WINDS OF RECENT DAYS...THERE MAY BE SUFFICIENT OPEN WATER OVER WRN LAKE SUPERIOR TO SUPPORT IFR CONDITIONS IN -SHSN AT KIWD THIS EVENING AS WINDS VEER MORE TO THE NW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 410 PM EST SAT FEB 22 2014 A TIGHT PRESSURE GRADIENT BETWEEN A LOW NEAR HUDSON BAY AND A HIGH PRESSURE RIDGE MOVING INTO THE MID MISSISSIPPI VALLEY WILL CONTINUE TO PRODUCE WESTERLY GALE FORCE GUSTS TO 35-40KTS TONIGHT. AS THE LOW WEAKENS ON SUNDAY...THE GRADIENT WILL WEAKEN AND LEAD TO WINDS DROPPING TO 30KTS. NORTHWESTERLY WINDS WILL CONTINUE SUNDAY NIGHT INTO THE FIRST HALF OF THE UPCOMING WORK WEEK...WITH GUSTS UP TO 25KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 5 PM EST SUNDAY FOR MIZ001-003. LAKE SUPERIOR... GALE WARNING UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR LSZ240>246- 263>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...MRD AVIATION...ROLFSON MARINE...SRF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
356 AM CST SUN FEB 23 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CST SUN FEB 23 2014 ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE WINTER WEATHER ADVISORY CONTINUES THIS MORNING. AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY BAND OF SNOW IS WEAKENING. THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1 RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT. THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2 INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS. THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF 17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13 TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO 1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE. THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE FOR THE NORTH TONIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN FEB 23 2014 MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST. HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES WOULD BE WARRANTED. THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT. WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST HOLD STEADY FOR THE EARLY MORNING HOURS. SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE 30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE. REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST. THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1128 PM CST SAT FEB 22 2014 VISIBILITY WILL CONTINUE TO BE LESS THAN 3SM THROUGH THE NIGHT FOR THE AREA ALONG AND SOUTHWEST OF A BBW-TIF-IEN LINE WITH LOCALIZED VISIBILITY AT OR BELOW 1SM IN THE SOUTHWEST ALONG AND SOUTH OF AN OGA-LBF LINE. CEILING WILL CONTINUE TO BE 1000-2000 FEET AGL IN THE SOUTHWEST THROUGH AT LEAST SUNDAY EVENING 03Z. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ022>025-035>038-056>059-071. WINTER STORM WARNING UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ069- 070. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1147 PM CST SAT FEB 22 2014 .UPDATE... ISSUED AT 939 PM CST SAT FEB 22 2014 PER COORDINATION AND WHERE CURRENT SNOW BAND IS SETTING UP...HAVE EXPANDED WINTER WEATHER ADVISORY TO INCLUDE FURNAS AND HARLAN COUNTIES. UPDATE ISSUED AT 859 PM CST SAT FEB 22 2014 COMPLICATED FORECAST AS WE HEAD INTO TONIGHT AS TO WHERE SNOW BANDS WILL SET UP. HAVE BEEN MONITORING SNOW BAND ACROSS WESTERN NEB WHICH HAS MIGRATED EASTWARD EARLY THIS EVENING. DRIER AIR TO THE EAST HAS BEEN SLOW TO OVERCOME BUT A SNOW BAND HAS MANAGED TO MOVE IN AND IS ORIENTED W/E GENERALLY FM KLBF TO KLXN TO KHDE AND POINTS JUST TO THE SOUTH. THE SNOW IS ALIGNED FAIRLY WELL WITH THE MID LEVEL FRONTOGENESIS WHICH IS PRIMARILY PROGGED ALONG OUR WESTERN CWA THROUGH THE FIRST PART OF THE NIGHT. HAVE EXPANDED OUR CURRENT WINTER WX ADVISORY TO INCLUDE PHELPS AND KEARNEY COUNTIES WHERE SNOW HAS COMMENCED AND A LONGER DURATION OF SNOW IS EXPECTED. AS WE HEAD INTO TONIGHT WE SEE AN INCREASE IN ISENTROPIC LIFT AS INDICATED ON THE 290K SURFACE AND THE LIFT PERSISTS FOR SEVERAL HOURS...INTO SUNDAY MORNING. THE UPPER JET STREAK NOSES ACROSS WESTERN NEB SUNDAY MORNING WITH LIFT CONTINUING SUNDAY MORNING IN LFQ OF JET. ONE OF THE MORE NOTABLE CHANGES IN THE LATEST MODEL RUNS THAT SNOW IS EXPECTED TO PERSIST LONGER SUNDAY MORNING WITH ADDITIONAL LIGHT ACCUMULATIONS POSSIBLE. SNOW AMOUNTS WILL BE DEPENDENT UPON SNOW BANDS WITH SEVERAL INCHES...AND LOCALLY HEAVY SNOWFALL POSSIBLE WITHIN THE BANDS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 407 PM CST SAT FEB 22 2014 ...ABOVE NORMAL UNCERTAINTY TONIGHT IN A SWATH OF SNOW THAT COULD END UP DUMPING 6-8 INCHES "IF" THE WORST CASE UNFOLDS... ALOFT: VERY LOW AMPLITUDE WNW CYCLONIC FLOW WILL REMAIN OVER THE CNTRL PLAINS THRU SUN. WV IMAGERY SHOWS A SUBTLE SHORTWAVE TROF OVER BRITISH COLUMBIA. PART OF THIS TROF WILL RACE THRU TONIGHT. SURFACE: A COLD FRONT MOVED THRU LAST NIGHT AND CURRENTLY EXTENDED FROM ST. LOUIS-OKLAHOMA CITY-LUBBOCK TX. THIS FRONT WILL SLOWLY SAG DEEPER INTO TX/AR BY SUNSET SUNDAY. MEANWHILE...CANADIAN HIGH PRES WILL GRADUALLY BUILD S THRU THE PLAINS. REST OF THIS AFTERNOON: INCREASING CLOUDS OVER S-CNTRL NEB WILL OBSCURE THE SUN WHILE N-CNTRL KS SHOULD SEE A NICE END TO THE DAY. HIGH TEMPS WILL OCCUR 4-5 PM. TONIGHT: BECOMING CLOUDY WITH A BAND OF SNOW DEVELOPING ACROSS THE FCST AREA AND IT COULD BECOME HEAVY IN A VERY NARROW SWATH OVER S-CNTRL NEB. PROBABILITIES OF NO SNOW AT ALL ARE HIGHEST OVER N-CNTRL KS. THIS WILL BE A JET STREAK DRIVEN EVENT AS WIND/MASS ADJUSTMENTS RESULT IN WARM AIR ADVECTION AND FRONTOGENESIS /FGEN/ ON THE FRONT THAT MOVED THRU LAST NIGHT. CROSS SECTIONS INDICATE MID- LEVEL UPRIGHT INSTABILITY AND LIFT WILL BE STRONG IN THE DENDRITIC GROWTH ZONE /DGZ/. SEVERAL SCENARIOS ARE POSSIBLE TONIGHT AND WE WILL REALLY NOT KNOW WHICH ONE IS RIGHT UNTIL WE SEE THIS UNFOLD. THIS FCST IS FRAUGHT WITH UNCERTAINTY AND WE ARE ADMITTEDLY CONSERVATIVE ON SNOW AMOUNTS AND THE AERIAL EXTENT OF THE ADVISORY. BE PREPARED FOR ADJUSTMENTS LATER THIS EVENING AND TONIGHT THAT COULD RESULT IN DRAMATICALLY INCREASING OR DECREASING AMOUNTS FOR YOUR AREA. 09Z AND 15Z SREF PROBABILITIES FOR .25" ARE HIGHEST IN THE ADVISORY AREA. THE 15Z PROBS FOR .25" ARE HIGHER THAN 09Z AND THE 70% CHANCE OF .25" NOW EXTENDS E TO GRI. THE 19Z RAP SUPPORTS THIS. A CHECK OF THE 18Z NAM HAS .25" TO HASTINGS. SNOW TOTALS: GENERALLY 1-3" OVER S-CNTRL NEB. 2-3" FROM THE TRI-CITIES WESTWARD...AND 3-4" PRIMARILY OVER DAWSON COUNTY. THIS IS OUR BEST STAB USING A BLEND THE 00Z/06Z/12Z MULTI-MODEL QPF. THAT PRESENTS A PROBLEM. TOO MUCH AVERAGING SHOULD HIT THE SWATH OF SNOW CORRECTLY...BUT IT MAY BE TOO BROAD COMPARED TO REALITY AND FCST AMOUNTS MAY NOT BE HIGH ENOUGH. SNOW-LIQUID RATIOS: USED PRIMARILY 15:1 THRU THE EVENING AND CLOSE TO 20:1 AFTER MIDNIGHT. GIVEN THE STRENGTH OF THE LIFT IN THE DGZ... THESE RATIOS COULD ALSO BE CONSERVATIVE. POSSIBLE WEAKNESSES IN TONIGHT/S FCST: 1) WE MAY BE TOO BROAD WITH THE EDGES OF THE SNOW BAND...I.E. IT MAY BE MORE NARROW THAN DEPICTED. 2) DO WE HAVE THE HIGHEST POPS IN THE RIGHT LOCATION? THE HI-RES GEM HAS THE BAND BETWEEN I-80 AND THE KS BORDER. WE ARE IN THE I-80 CORRIDOR. 3) DEWPOINTS MAY BE TOO HIGH N OF I-80. DEWPOINTS IN THE SINGLE DIGITS ARE AS CLOSE AS O`NEILL. ADVECTION OF THIS VERY DRY AIR WILL PLAY A ROLE IN LIMITING THE NRN EXTENT OF THE BAND. 4) ARE AMOUNTS HIGH ENOUGH? WOULD NOT BE SURPRISED TO SEE A NARROW STRIP OF WARNING LEVEL SNOW /6-8"/ SOMEWHERE GIVEN THE RATIOS WE ARE LIKELY TO SEE. UNCERTAINTY: PLEASE KEEP IN MIND THAT THERE ARE SOME AREAS THAT HAVE SNOW IN THE FCST...BUT WILL SEE NO SNOW AT ALL. THIS ESPECIALLY APPLIES IF THE FCST PROBABILITY OF SNOW AT YOUR LOCATION IS 40% OR BELOW. THERE WILL BE A SHARP CUT-OFF ON THE NRN AND SRN FRINGES OF THIS BAND. THE SMALL SCALE NATURE OF THIS BAND IS PROBLEMATIC FOR PINNING DOWN DETAILS...BUT THIS COULD END UP A WARNING LEVEL EVENT FOR SOME COUNTIES. LOW TEMPS WERE FROM CONSENSUS OF 2M TEMPS WHICH RAISED TEMPS SEVERAL DEGREES. SUN: FGEN LIFTS N AND MID-LEVELS DRY OUT WITH STABILITY RETURNING. PATCHES OF LIGHT SNOW WILL LINGER THRU MID-MORNING...BUT THE ACCUMULATING SNOW WILL ESSENTIALLY BE OVER. PLENTY OF CLOUDS WILL REMAIN AND A FEW FLURRIES COULD REDEVELOP N AND W OF THE TRI- CITIES IN THE AFTERNOON. HIGH TEMPS HAVE A LOT OF CONTINUITY WITH THE 4 AM GID FCST. THE ONLY CHANGE WAS TO NUDGE TEMPS DOWN E OF HWY 281. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 407 PM CST SAT FEB 22 2014 THE BIG STORY WILL BE THE WELL BELOW NORMAL TEMPERATURES ALONG WITH SEVERAL CHANCES OF WINTRY PRECIPITATION. HIGH TEMPERATURES THROUGH THE PERIOD WILL GENERALLY AVERAGE 10 TO 15 DEGREES BELOW NORMAL. SUNDAY NIGHT AND MONDAY...MID LEVEL ISENTROPIC LIFT WILL RESULT IN SOME LOW END LIGHT SNOW CHANCES PRIMARILY ACROSS OUR NORTHERN ZONES WITH THE BETTER SNOW CHANCES WELL NORTH OF OUR FORECAST AREA ACROSS SOUTH DAKOTA. ALTHOUGH NOT IN THE OFFICIAL FORECAST AS OF RIGHT NOW...WILL ALSO NEED TO WATCH OUT FOR THE POSSIBILITY OF LIGHT FREEZING DRIZZLE ACROSS OUR NORTHERN AND WESTERN ZONES LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING. ANY FREEZING DRIZZLE WOULD PRIMARILY BE CONFINED TO OUR WESTERN AND NORTHERN ZONES. THE 12Z GFS AND ECMWF DO NOT REALLY SHOW MUCH IN THE WAY OF FREEZING DRIZZLE POTENTIAL...BUT THE 12Z AND 18Z NAM DO INDICATE SOME POTENTIAL WITH LOW LEVEL SATURATION BENEATH A DRY MID LEVEL. THE NAM IS STILL A BIT OF AN OUTLIER AND THE POTENTIAL EVEN IN THE NAM IS SO MARGINAL THAT WE WILL CONTINUE TO LEAVE FREEZING DRIZZLE OUT OF THE FORECAST FOR NOW. ANY SNOW AMOUNTS WOULD LIKELY BE VERY LIGHT AND LESS THAN ONE HALF INCH. MONDAY NIGHT THROUGH TUESDAY...A SHORTWAVE TROUGH WILL TRACK SOUTHEAST OUT OF CANADA. ASSOCIATED UPPER JET DYNAMICS AND A PROGRESSIVE BAND OF MID LEVEL FRONTOGENESIS WILL LEAD TO ADDITIONAL CHANCES FOR LIGHT SNOW. NOT EXPECTING MUCH SNOW AT THIS TIME WITH MOST PLACES SEEING FLURRIES UP TO 1 INCH. COLDER AIR WILL FILTER IN ON TUESDAY WITH HIGHS STUCK IN THE 20S FOR MOST AREAS. WEDNESDAY THROUGH SATURDAY...WILL TRANSITION FROM A NORTHWESTERLY FLOW PATTERN TO A MORE ZONAL PATTERN...WITH PERHAPS EVEN THE DEVELOPMENT OF A TROUGH OVER THE WESTERN CONUS LATE IN THE PERIOD. OVERALL...THIS IS MORE LIKELY BE A DRY AND COOL PERIOD FOR OUR FORECAST AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1139 PM CST SAT FEB 22 2014 DETERIORATING CONDITIONS ARE ANTICIPATED AT KGRI OVER THE NEXT FEW HOURS AS LIGHT SNOW OVERTAKES THE TERMINAL. WHILE WINDS WILL NOT BE PARTICULARLY STRONG...COULD SEE VSBYS DROP DOWN TO NEAR 2SM IN HEAVIER BANDS OF SNOW AS THEY DEVELOP AND CEILINGS LOWER TO NEAR 1500FT. OTHERWISE...SNOWFALL SHOULD BEGIN TO TAPER OFF DURING THE LATER MORNING HOURS...WITH MVFR CEILINGS ANTICIPATED TO PERSIST FOR MUCH OF THE DAY BEHIND THIS DEPARTING DISTURBANCE. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR NEZ060-061- 072>074-082-083. KS...NONE. && $$ UPDATE...FAY SHORT TERM...HALBLAUB LONG TERM...WESELY AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1242 AM EST SUN FEB 23 2014 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL BRING THE CHANCE FOR SNOW SHOWERS LATE TONIGHT...AND RAIN OR SNOW SHOWERS ON SUNDAY. COLDER AIR WILL RETURN FOR THE BEGINNING OF THE WORK WEEK WITH LAKE EFFECT SNOWS OVER CENTRAL NEW YORK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 8 PM UPDATE... THE CURRENT FCST IS IN FAIRLY GOOD SHAPE...SO ONLY RELATIVELY SMALL CHGS WERE MADE ATTM. RGNL RADAR IMAGERY SHOWS A NARROW BAND OF LGT PCPN (MAINLY -SN) EXTENDING FROM CNTRL IL-NRN IN-NRN OH-NW PA THIS EVE. THE LATEST RUC-13 AND HRRR OUTPUT APPEAR TO BE DOING A REASONABLY GOOD JOB HANDLING THE EVOLUTION OF THIS PCPN SO FAR. BOTH MODELS SUGGEST IT WILL STREAK INTO THE TWIN TIERS BY 06-09Z...THEN EXIT BY ARND 15Z SUN MRNG...UNDERNEATH DECENT 850-700 MB FGEN FORCING. THE MAIN FACTORS GOING AGAINST PCPN DVLPMT LOCALLY ARE DRY LOW-LVL AIR TO OVERCOME INITIALLY...AND ALSO NON-DESCRIPT JET DYNAMICS. OVERALL...WE FELT THE COURSE OF LEAST REGRET WAS TO BUMP POPS UP TO LIKELY VALUES WHERE WE HAVE SOME LGT SNOW ACCUMS MENTIONED LTR TNT INTO EARLY SUN (MOSTLY ACRS NY`S SRN TIER...WITH MAX AMTS GENERALLY 1" OR LESS). SHSN SHOULD DIMINISH QUICKLY TO FLRYS LTR SUN MRNG...THEN END ALTOGETHER BY MIDDAY. OTHWS...OUR TEMP/DEW PT GRIDS WERE MASSAGED SLIGHTLY THIS EVE...TO BEST REFLECT THE LATEST OBSERVATIONAL TRENDS. PREV DISC... 330 PM UPDATE... WEAK DISTURBANCE OVER THE OHIO VALLEY CREATING LIGHT PRECIPITATION OVER IL/IN WILL MOVE OUR WAY TONIGHT. I FOUND ONE OB TO THE WEST SHOWING 2 1/2SM IN SNOW. BASED ON THIS AND MODEL QPF...NOT EXPECTING MUCH MORE THAN A LIGHT DUSTING OF SNOW TONIGHT ESPECIALLY NEAR OR JUST NORTH OF THE NY/PA LINE. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... 330 PM UPDATE... DISTURBANCE ABOVE MAY CONTINUE A FEW SNOW SHOWERS INTO MIDDAY SUNDAY BEFORE ENDING AS A SPRINKLE OR FLURRY. NOT EXPECTING MUCH. BIGGER STORY WILL BE MUCH COLDER AIR BUILDING IN SUNDAY NIGHT AND LASTING THROUGH TUESDAY. LAKE SNOWS LOOK LIKELY WITH A FLOW SETTLING IN BETWEEN 290 AND 270. ONE LIMITING FACTOR AT LEAST DURING THE DAY MAY DIURNAL EFFECTS. TAKE MONDAY AFTERNOON FOR EXAMPLE WITH NAM BUFKIT PROFILES SHOWING SURFACE BASED CAPE OF ABOVE 40 J/KG. BASED ON LOCAL RESEARCH, THESE VALUES COUPLED WITH LOW TO MODERATE SHEAR WOULD PROMOTE MORE OF A DIFFUSE BAND OR OPEN CELLULAR SNOW SHOWERS DURING THE AFTERNOON THAN A WELL DEFINED BAND. WITH THAT IN MIND TRIED TO SHOW THE BEST ACCUMS OF AT LEAST A FEW INCHES DURING THE NIGHTTIME AND EARLY PART OF THE DAY. COULD SEE NEEDING AN ADVISORY AT SOME POINT DOWN THE ROAD BUT A WARNING DOES NOT SEEM LIKELY...THUS AFTER COORDINATION WITH BUFFALO NO LAKE EFFECT WATCH AT THIS POINT. HIGHS GENERALLY IN THE 20S THROUGH TUESDAY. I DIDN`T TOUCH TUESDAYS HIGHS OF IN THE 20S. I DID NOTICE MODEL GUIDANCE, ALMOST ALL OF IT, IS IN THE TEENS. WILL BE INTERESTING TO SEE WHAT HAPPENS AS 925S SUPPORT OUR HIGHS OF 20S. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MEDIUM RANGE MODELS CONTINUE TO SHOW EXCELLENT AGREEMENT THROUGH THE EXTENDED PERIOD BOTH ALOFT AND AT THE SFC. IN GENERAL THE PERIOD WILL BE VERY COLD WITH TEMPS RUNNING 15 TO 25 DEGREES BELOW SEASONAL NORMALS. TUESDAY NIGHT INTO WED, MODELS INDICATE SFC LOW PRES WELL OFF THE MID ATLANTIC COAST WITH THE GFS FURTHER OUT TO SEA THAN THE ECMWF. CURRENT MODEL TREND IS FOR AN EVEN MORE EASTERLY TRACK SO WILL CONTINUE WITH JUST CHC POPS THROUGH THIS PERIOD. REST OF FORECAST LOOKS PRIMARILY DRY WITH SCATTERED LAKE EFFECT SNOW SHOWERS AND FLURRIES EAST/SOUTHEAST OF LAKE ONTARIO. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... 06Z UPDATE... VFR AT ALL SITES WITH NARROW BAND OF MID-LVL CLOUDS ACRS NY TERMINALS. THIS NARROW BAND IS ASSOCIATED WITH LIGHT SNOW BUT IS EXPECTED TO WEAKEN AS IT MOVES OFF TO THE EAST. THUS HAVE KEPT MVFR TEMPO/D INTO KITH/KELM AND KBGM FROM 08Z-12Z AT TERMINALS BUT HAVE BROUGHT VSBYS UP TO 5SM. IF TREND OF WEAKENING CONTINUES, WILL REMOVE COMPLETELY BUT NOT CONFIDENT ENOUGH AS IT CONTINUES TO BE ON TERMINALS` DOORSTEP. FURTHER NORTH AT KSYR AND KRME EXPECT VFR THROUGH THE NEXT 24 HOURS, THOUGH APPEARS THAT LAKE EFFECT WILL TRY TO DEVELOP AFTER MIDNIGHT. HOWEVER WHERE THIS SETS UP REMAINS IN QUESTION AND WILL EVALUATE MORE FOR 12Z ISSUANCE. ANOTHER WAVE WILL ZIP ACROSS PENNSYLVANIA LATE TONIGHT AND MAY BRING LIGHT SNOW TO AVP, THUS HAVE INCLUDED PROB30 MENTION BETWEEN 03Z AND 06Z. NORTHWEST FLOW BEHIND WAVE WILL KICK IN ACROSS NY TERMINALS AFTER 00Z AND THIS MAY LEAD TO MVFR CIGS DEVELOPING AT KITH TOWARD 06Z MON. WSW WINDS AROUND 10KTS TONIGHT WILL CONTINUE THROUGH THE DAY. OUTLOOK... LATE SUN NGT THROUGH TUE ATN...MVFR/IFR RESTRICTIONS IN LAKE EFFECT -SHSN CNTRL NY TERMINALS. TUE NGT THROUGH THU...RESTRICTIONS POSSIBLE IN SCATTERED SNOW SHWRS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...HEDEN NEAR TERM...HEDEN/MLJ SHORT TERM...HEDEN LONG TERM...RRM AVIATION...PVN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
301 AM CST SUN FEB 23 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 301 AM CST SUN FEB 23 2014 CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING FROM THE EASTERN PACIFIC INTO ALASKA...A BROAD UPPER LOW OVER THE CANADIAN ARCHIPELAGO...AND BROAD TROUGHING ACROSS ALL OF SOUTHERN CANADA INTO THE UPPER MIDWEST. SHORTWAVES OF NOTE FOR THIS FORECAST INCLUDE ONE OVER WEST CENTRAL BRITISH COLUMBIA...ONE OVER CENTRAL ALBERTA...AND THE LAST AS PART OF THE UPPER LOW ON THE WESTERN SIDE OF THE CANADIAN ARCHIPELAGO. A NORTHWEST 925MB FLOW CONTINUES TO GRADUALLY DRAW COLDER IN OUT OF CANADA TOWARDS THE FORECAST AREA...NOTED BY THE 00Z MPX SOUNDING AT -15C. THAT SAME SOUNDING ALSO CONTINUES TO DEPICT PLENTY OF DRY AIR...RESULTING IN CLEAR SKIES EARLY THIS MORNING. COMBINATION OF THE CLEAR SKIES AND COOLING 925MB TEMPS HAS ALLOWED TEMPERATURES TO DROP INTO THE SINGLE DIGITS ABOVE ZERO. IF THE 5 TO 15 MPH BREEZE WAS NOT PRESENT TO KEEP THE AIR MIXED...TEMPERATURES WOULD PROBABLY BE A LOT COLDER. OVERALL LITTLE CHANGE IS PROGGED BY MODELS TO OCCUR IN THE NEXT 24 HOURS IN TERMS OF THE UPPER LEVEL PATTERN OVER THE UPPER MIDWEST AND THE FORECAST AREA. WE STILL REMAIN UNDER THE INFLUENCE OF A DRY NORTHWEST LOW TO MID LEVEL FLOW...WHICH SHOULD HELP KEEP SKIES MAINLY CLEAR THROUGH TODAY AND MUCH OF TONIGHT. THERE ARE SOME INDICATIONS OF CIRRUS APPROACHING LOCATIONS WEST OF THE MISSISSIPPI RIVER LATE TONIGHT...BUT THATS REALLY ABOUT IT FOR CLOUDS. 925MB TEMPS TODAY ARE FORECAST TO RANGE BETWEEN -13 AND -16C...ABOUT 1-2C COLDER THAN YESTERDAY. THEREFORE...WE SHOULD SEE HIGHS JUST SLIGHTLY COOLER THAN YESTERDAY. SKIES STAYING CLEAR THROUGH MUCH OF TONIGHT PLUS 925MB TEMPS FALLING TO -14 TO -19C...COLDEST OVER WISCONSIN...SHOULD ALLOW FOR LOWS IN MOST LOCATIONS IN THE SINGLE DIGITS BELOW ZERO. AGAIN...THERE LOOKS TO BE A PERSISTENT NORTHWEST BREEZE THROUGH TONIGHT HELPING TO PREVENT DECOUPLING. STILL...THE TYPICAL COLD SPOTS COULD TRY TO APPROACH -10F. WIND CHILLS LOOK TO GET CLOSE TO ADVISORY CRITERIA...BUT TOO MARGINAL AT THIS POINT TO ISSUE AN ADVISORY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 301 AM CST SUN FEB 23 2014 THE 2 MAIN IMPACTS REMAIN FOR THE LONG TERM... 1. POTENTIAL FOR SOME SNOW LATE MONDAY AFTERNOON AND NIGHT 2. THE BITTER COLD AIR...ESPECIALLY TUESDAY NIGHT AND BEYOND. REGARDING IMPACT NUMBER 1...THE SHORTWAVES CURRENTLY OVER CENTRAL BRITISH COLUMBIA AND ALBERTA REMAIN PROGGED TO PHASE TOGETHER OVER THE DAKOTAS ON MONDAY...THEN QUICKLY SLIDE THROUGH THE FORECAST AREA AROUND 06Z TUESDAY. MOISTURE IS LACKING FOR THESE SHORTWAVES...WITH PRECIPITABLE WATER CLIMBING TO 0.1-0.2 OF AN INCH. HOWEVER...SOME WEAK ISENTROPIC LIFT ON THE 275-280K SURFACES COMBINED WITH DPVA AHEAD OF THE SHORTWAVES SHOULD BE ENOUGH TO SQUEEZE OUT SOME LIGHT SNOW. SNOW SHOULD BE SOMEWHAT FLUFFY...THOUGH THE BULK OF THE LIFT LOOKS TO OCCUR ABOVE THE DENDRITIC GROWTH ZONE. TIMING WISE...MODELS CONTINUE TO SLOW DOWN THE SNOW MOVING INTO THE AREA...WITH THE 23.00Z NAM/GFS/CANADIAN/ECMWF KEEPING MUCH OF THE SNOW WEST OF THE AREA PRIOR TO 00Z TUESDAY. ITS MORE OF A MONDAY NIGHT SNOW NOW. DID RAISE CHANCES UP FOR MONDAY EVENING WEST OF THE MISSISSIPPI RIVER WITH GOOD MODEL AGREEMENT FOR THE SNOW THEN. AFTER 06Z MONDAY... MODELS DIVERGE ON HOW MUCH SNOW MIGHT BE LEFT WITH THE 23.00Z GFS/CANADIAN DRY WHEREAS THE NAM AND ECMWF STILL HAVE SOME SNOW LEFT. SPLIT THE DIFFERENCE AND HAVE SOME 20-30 PERCENT CHANCES FOR NOW. IT APPEARS MUCH OF THIS HAS TO DO WITH THE TIMING OF THE PHASED SHORTWAVE. NOW IMPACT NUMBER 2...THE COLD. IN THE WAKE OF MONDAY NIGHTS SHORTWAVE TROUGH...925MB TEMPS FALL TO -15 TO -20C. A SECOND AND MORE POTENT COLD SURGE REMAINS PROGGED TO PLUNGE INTO THE AREA TUESDAY NIGHT...DROPPING 925MB TEMPS TO -23 TO -25C BY 12Z WEDNESDAY. THIS SURGE IS BEHIND THAT SHORTWAVE CURRENTLY OVER THE CANADIAN ARCHIPELAGO. WIND CHILL ADVISORIES SEEM ALL BUT LIKELY TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BOUT OF WARM ADVECTION IS SUGGESTED FOR WEDNESDAY AHEAD OF AN ARCTIC COLD FRONT DROPPING SOUTH OUT OF CANADA...THOUGH IT APPEARS A BRISK WEST WIND WILL ACCOMPANY IT. THEN ITS BACK TO THE COLD AS ANOTHER IMPRESSIVE SURGE OF ARCTIC AIR DIVES SOUTH INTO THE REGION FOR THURSDAY ON SOME BRISK NORTHWEST WINDS. 925MB TEMPS FROM THE 23.00Z GFS AND ECMWF DROP TO -23 TO -27C BY 12Z THURSDAY...WHILE 850MB TEMPS APPROACH -30C ACROSS OUR NORTH. THESE READINGS ARE NEARLY 3 STANDARD DEVIATIONS BELOW NORMAL. BEYOND THURSDAY...MODELS BEGIN TO DIVERGE A BIT WITH THE HANDLING OF THE COLD AIR. THE 23.00Z GFS TRIES TO MODIFY THE COLD AIR SOMEWHAT FROM THE FLOW BECOMING MORE ZONAL ACROSS THE NORTHERN TIER OF THE U.S.. THE 23.00Z ECMWF ALONG WITH EXTRAPOLATION OF THE CANADIAN HAS THAT SAME ZONAL FLOW...JUST A SMIDGE FURTHER SOUTH...WHICH RESULTS IN A CONTINUATION OF THE DEEP FREEZE. FOR THE FORECAST LEANED A BIT CLOSER TOWARDS THE ECMWF. OVERALL FOR TEMPERATURES TUESDAY THROUGH SATURDAY...STAYED CLOSE TO A CONSENSUS OF 30 DAY BIAS CORRECTED GUIDANCE...WHICH PERFORMED WELL IN PAST COLD SPELLS THIS WINTER. THURSDAY NIGHT COULD BE VERY COLD WITH A SURFACE RIDGE PARKED OVERHEAD. WOULD NOT BE SURPRISED IF SOME OF THE TYPICAL COLD SPOTS TO APPROACH -30F. GIVEN HOW DEEP SOME OF THE FROST IS ALREADY...WATER MAINS UNDER ROADS WILL NEED TO BE WATCHED CLOSELY. LUCKILY THE HIGHER SUN ANGLE CAN HEAT THE TOP OF THE ROAD SURFACES MORE NOW THAN IN JANUARY...BUT STILL THIS COLD AIR WILL NOT BE GOOD. THERE ARE STRONG INDICATIONS TOO FROM THE CFS THAT THE BELOW NORMAL WEATHER COULD PERSIST THROUGH ALL OF MARCH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1110 PM CST SAT FEB 22 2014 VERY LITTLE CHANGE IN CONDITIONS EXPECTED THROUGH SUNDAY EVENING. HIGH PRESSURE WILL REMAIN CENTERED OVER SASKATCHEWAN WITH THE RIDGE FROM THE HIGH EXTENDING SOUTHEAST INTO IOWA AND MISSOURI WHILE LOW PRESSURE REMAINS CENTERED NEAR HUDSONS BAY. THE GRADIENT BETWEEN THESE TWO FEATURES WILL KEEP THE WINDS OUT OF THE WEST TO NORTHWEST AT SPEEDS OF 10 TO 15 KNOTS. COULD GET A LITTLE GUSTY SUNDAY AFTERNOON AT KRST AND HAVE INCLUDED THESE IN THE FORECAST BEFORE THE INVERSION DEVELOPS AND CUTS OFF THE MIXING EARLY IN THE EVENING. && .CLIMATE... ISSUED AT 301 AM CST SUN FEB 23 2014 GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS HOW FEBRUARY AND THE WINTER WOULD STACK UP BASED ON THE CURRENT FORECAST... ...FOR THE MONTH OF FEBRUARY... LA CROSSE... 9.5 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1873... 3.9 1936... 4.3 1899... 9.4 ROCHESTER... 6.9 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1936... 0.5 1979... 5.7 1917... 6.0 ...FOR THE WINTER...DECEMBER THROUGH FEBRUARY... LA CROSSE... 11.6 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1872-1873... 8.4 1874-1875... 10.5 1977-1978... 11.4 1935-1936... 11.4 ROCHESTER... 8.9 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1978-1979... 5.6 1886-1887... 5.9 1935-1936... 8.1 1977-1978... 8.7 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...04 CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
525 AM EST Sun Feb 23 2014 ...Small Hail and Frequent Lightning Possible Along the Panhandle Coast This Morning... .Mesoscale Update... A cluster of storms off of the panhandle coast will move ashore over the next hour or so. These storms have been producing frequent lightning, heavy rain, and may contain some small hail. As the morning progresses, the hail threat will diminish and the focus will shift to primarily heavy rain. See previous discussions below. && .Prev Discussion [355 AM EST]... .Near Term [Through Today]... The large scale pattern is highlighted by a persistent broad trough over much of Conus. This leaves nearly zonal flow over NE Gulf region. However a series of shortwaves will continue to move Ewd providing increasing clouds and just enough lift that when combined with surface features will maintain an unsettled weather pattern today. Mid-High clouds streaming Ewd overnight assocd with lead shortwave moving Ewd across mid-South will cross NE Gulf region later today with the forecast area in the right entrance region of the upper jet. At surface...in response to Ewd moving shortwave... W-E warm front located across the Nrn Gulf waters Ewd across N/Cntrl FL overnight will lift Nwd to coast by sunrise then to vcnty of I-10 during the day with light Sly flow in its wake. Upstream cold front across mid-South around sunrise moves SEWD to Ern TN/N-Cntrl AL/Srn MS by sundown with WAA and isentropic upglide spreading over our area. Early radar showing leading edge of moisture approaching wrn most Panhandle waters. Patchy to areas of fog initially south of I-10 will accompany rain and spread E/N thru the day. The combination of upper and lower features will yield an expansive area of showers with isolated to sct thunderstorms (highest Panhandle waters) moving SW-NE to reach our Wrn CWA around sunrise and then progress EWD. Afternoon dew point will rise from mid 60s coast to upper 50s Nrn tier AL/GA counties. This depicted well in HRRR and other High Res guidance. Limited mid-level lapse rates and a relatively cool boundary layer should limit the potential for any strong storms. Best chance per CAM would be Panhandle waters. However, with the upper flow parallel to the warm boundary, main concern is training of cells is possible with locally heavy rainfall possible especially during the aftn QPF south of FL border exceeding 1 inch. Will go with 70-30% W-E POP gradient in morning then 80-40% in the afternoon. Temperatures will be tricky, depending on the eventual position of the warm front and the coverage of the rainfall. However, expect warmest temperatures along and south of I-10 (lower 70s), with lower to mid 60s for much of SE AL and SW GA. .Short Term [Tonight Through Tuesday]... By the time the evening rolls around, the polar jet max will be racing east and the northern stream trough will dip a bit deeper into the Southeast. This will act to better stack the frontal system as surface high pressure presses a cold front into our region. The surface cold front will merge with Sunday`s warm front and settle in over north Florida before deep layer zonal flow sets in and stalls the frontal system once again. As the two fronts merge, and the system stacks, we`ll likely see a brief uptick in shower activity along the surface front. Expect rainfall to be much lighter than Sunday afternoon as the surge of more tropical- like moisture will have moved east. On Monday, a southern stream impulse will be lifting north through the northern Gulf, eventually aligning with the surface front and pressing the northern stream trough back to the north out of our area. Exactly where the surface front will be is a bit uncertain, though the most likely scenario would place the front along or south of I-10 in north Florida, possibly as far south as the extreme northern Gulf. Should the surface front be positioned across north Florida, things could become interesting with respect to the potential for an isolated strong storm. Due to the limited tropospheric penetration of the southern stream impulse, the mid- level cooler/drier air will not be forced as aggressively to the north. This will effectively steepen mid-level lapse rates across the Tri-State region with deep layer shear around 60 knots more than sufficient to support organized updrafts. In the other corner, slightly warmer mid/upper level temps where the northern stream trough has retreated a bit, will essentially cap the potential for deep moist convection, though as the southern stream impulse moves away, cooler mid/upper temps may slide back south late in the day, eroding the cap. Bottom line is that there is a very low potential for strong storms on Monday, though should convection get going, and should the mid/upper level cap erode the potential exists for a storm or two to produce gusty winds and possibly some small hail. Tuesday, is really the more interesting day as a more potent southern stream impulse races east out of Texas, through the lower MS Valley and into the southeast by the late afternoon. Should we be able to mix out the mid-level cap early enough that the shortwave is overhead, we`d be able to tap into some rather steep lapse rates and strong deep layer shear. This could support the development of more severe level storms with the threat for damaging winds and hail. So, through Tuesday expect showers and isolated storms to be around. Most likely across north Florida Monday, spreading further inland and increasing in coverage on Tuesday. The potential for a strong storm or two exists on Monday, with a chance for severe storms on Tuesday. Uncertainty remains very high regarding strong to severe storms, as my lengthy discussion above lays out all of the variables that must align just right. Expect above average temperatures, in the middle to even upper 70s in some spots, both Monday and Tuesday. .Long Term [Tuesday Night Through Sunday]... A cold front will move through Wednesday with a chance of showers and thunderstorms. Behind the front high pressure will build in bringing cooler temperatures and drier air. The models differ with a series of low pressure systems at the end of the period. The GFS has precipitation moving across central Florida Friday and a low developing off the East coast near Georgia and South Carolina followed by another low forming over Texas. The Euro has a Gulf low forming near the Texas/Louisiana border Friday night then moving across north Florida Saturday. .Aviation... [Through 06Z Monday] MVFR CIGS should develop during the predawn hours or shortly after sunrise at ECP, TLH and VLD, lowering to IFR CIGS during the morning hours. There will be a chance of MVFR CIGS at DHN and ABY during the day tomorrow as well. With a prolonged rain event any improvement in evening VSBYS/CIGS will begin to again lower after 02z and winds die off. Rain and isold thunderstorms will move in from the west during the morning. Heaviest rain and thunderstorm activity will likely be focused in Florida Panhandle particularly at ECP, but also possibly affecting TLH. Main impact would be through reduced visibility due to very heavy rain. Thunderstorms may also linger at ECP or TLH south of warm front for several hours in the afternoon. .Marine... Generally low winds and seas will prevail through mid-week until a cold front passes through the northern Gulf increasing winds to advisory levels temporarily on Wednesday. Low winds and seas will return to finish out the week. .Fire Weather... With increased rain chances thru tonight, no red flag conditions are expected and none is forecast through mid-next week. .Hydrology... There is a potential for heavy rainfall this afternoon with the heaviest rain likely confined to north Florida, especially along and west of the Apalachicola River. Widespread average totals will be around 1-2 inches with isolated spots possibly receiving up to 3 to 5 inches. Flash flooding will likely not be a concern as these basins should be able to accommodate the expected rainfall amounts. In areas where heavy rainfall is expected, rivers may reach minor flood stage Monday or Tuesday. The Apalachicola at Blountstown is forecast to reach minor flood stage Sunday morning. For the latest hydrology information, please monitor: www.water.weather.gov/ahps2/index.php?wfo=tae && .Preliminary Point Temps/PoPs... Tallahassee 69 59 75 54 74 / 80 70 40 10 50 Panama City 67 60 70 57 69 / 80 70 40 20 50 Dothan 64 56 73 51 71 / 70 50 10 10 50 Albany 65 55 73 49 72 / 70 50 10 10 40 Valdosta 70 58 75 53 73 / 70 70 40 10 40 Cross City 73 60 75 57 75 / 50 70 40 10 50 Apalachicola 67 61 69 58 67 / 60 70 40 10 50 && .TAE Watches/Warnings/Advisories... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...HARRIGAN SHORT TERM...HARRIGAN LONG TERM...WESTON AVIATION...BLOCK MARINE...HARRIGAN FIRE WEATHER...BLOCK HYDROLOGY...HARRIGAN/WESTON Area Forecast Discussion National Weather Service Lincoln IL 957 AM CST Sun Feb 23 2014 .DISCUSSION... ISSUED 956 AM CST Sun Feb 23 2014 Lingering band of light snow in the southeast CWA has pushed into Indiana. Radar mosaics still showing quite a few returns along the I-70 corridor, but these are mostly elevated as surface obs are showing cloud heights of 7000 feet or higher, so little more than flurries anticipated the remainder of the morning. Persistent mid level clouds continue to stream over the remainder of the forecast area and should continue through the afternoon. Lowered temperatures a couple degrees across the southeast CWA as they had continued to slip downward as the snow began a few hours ago, but the forecast over the remainder of the area still is in decent shape. Geelhart && .AVIATION... ISSUED 540 AM CST Sun Feb 23 2014 VFR conditions will prevail at all TAF sites next 24hrs. Mid clouds around 9kft will overspread all sites this morning and remain over the area/sites through the morning and into the afternoon. Models indicate that the clouds will slide south away from the TAF sites this afternoon, but satellite loop/trends show clouds moving due east. So will keep at least BKN mid clouds over the area into this evening. Then skies will clear around midnight. Winds will be northerly to start and then shifts to northwesterly as a high pressure ridge pushes into the area late this afternoon and into the evening. Auten && .PREV DISCUSSION... ISSUED 330 AM CST Sun Feb 23 2014 SHORT TERM...Today through Wednesday night Surface cold front has pressed south of the Ohio River into NW AR while 1042 mb arctic high pressure over Alberta was nosing into the central and northern plains. Colder air easing south into central IL early this morning with temps slipping through the 20s over central IL and low to mid 30s in southeast IL. Temps as cold as 19F at Galesburg and Lacon. Frontogenetic forecasting close to 850 mb boundary near I-70 had band of light snow that diminished east into central IN past few hours with dusting to as much as 1 inch between I-72 and I-70. Will carry just slight chance of light snow this morning over southeast IL per HRRR model run. Radar mosaic shows light pcpn returns and mainly virga over northern MO into NW counties. RUC & HRRR keeps most of this very light snow west of central IL this morning but could be a few flurries this morning into central IL. Clouds to decrease from the north during the afternoon and linger longest in southeast IL. Much colder highs today range from mid 20s from Peoria and Bloomington north to 35-40F over southeast IL with Lawrenceville near 40F. Arctic high pressure noses into the mid MS river valley tonight and brings fair skies and cold lows of 5-10F from Lincoln north and mid to upper teens in southeast IL. Clouds increase Monday morning ahead of northern stream clipper system which digs into the Midwest Monday night. Slowed down chances of light snow Monday afternoon as central IL appear dry through sunset Monday with best chances of light snow arriving Monday night northern half of CWA. Generally less than 1 inch of snow with northern IL having as much as 1-2 inches of snow possible. Highs Monday again in mid 20s north and mid to upper 30s in southeast IL. Lows Monday night in the teens central IL and lower 20s southeast IL. Chances of light snow NE of central IL by Tuesday morning. Highs Tue range from lower 20s northern areas to mid 30s in southeast IL. Core of arctic high pressure settles into MO by 18Z/noon Wed and brings even colder air into the region during middle of the week. Lows overnight Tue night into early Wed morning could reach zero to 5 below NW of IL river with single digit lows over much of central IL and far southeast IL around 10F. Highs Wed in the mid teens NE to lower 20s SW and SE areas. Lows Wed night again in the single digits over northern half of CWA and lower teens south. LONG TERM...Thursday through Saturday night Temps modify slightly during end of week but still average below normal through next weekend. The 8-14 day outlook for Mar 2-8 has 60-70% chance of below normal temperatures and 40% chance of above normal precipitation, which has been the normal for this winter. Generally dry and cold conditions expected late this week into next weekend. Though ECMWF and GEM models show some light QPF Friday while heavier QPF passes south of IL Friday. GFS model is dry over IL on Friday. Stayed close to ALLblend pops late this week and into the weekend which is dry. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
543 AM CST SUN FEB 23 2014 .DISCUSSION... 213 AM CST TODAY... BROAD SFC RIDGE STRETCHES FROM THE NORTHERN PLAINS SOUTHEAST THROUGH THE WESTERN OHIO VALLEY. THIS HAS RESULTED IN A LIGHT NORTHWEST FLOW ACROSS NORTHERN IL/NORTHWEST IN EARLY THIS MORNING. BAROCLINIC ZONE REMAINS ORIENTED FROM CENTRAL MO STRETCHING NORTHEAST THROUGH CENTRAL IL/IN AND DRIFTING SOUTHEAST. IR IMAGERY SHOWS THE AREA OF CLOUDS WELL...ASSOCIATED WITH THIS BAND OF PRECIP. THEN JUST WEST OF THIS FEATURE WAS YET ANOTHER WEAK MID- LVL WAVE THAT HAD ANOTHER AREA OF MID/UPR LVL MOISTURE ASSOCIATED WITH IT AND WAS SLIDING EAST...BEING STEERED BY THE SEMI-ZONAL FLOW IN THE MID-LVLS. TEMPS THIS MORNING WILL HOVER AROUND THE TEENS FOR THE BULK OF THE FORECAST AREA...PERHAPS HOLDING IN UPR TEENS/LOW 20S FOR THE SOUTHERN CWFA. OTHERWISE FOR TODAY HIGH PRESSURE WILL PUSH THIS AREA OF CLOUDS THIS MORNING TO THE SOUTH...AND ALLOW FOR A DRY DAY. SKIES WILL EVENTUALLY BECOME P-CLOUDY BY MIDDAY...WITH HIGHS WARMING MAINLY INTO THE 20S. CLOSER TO 30 FOR THE FAR SOUTHERN CWFA. THEN FOR TONIGHT...HIGH PRESSURE WILL CONTINUE TO HOLD ACROSS THE FORECAST AREA AND LIMIT CLOUD COVER. JUST NORTH OF THE AREA THOUGH...AND CLOSER TO A STRONGER MID-LVL VORT WILL BE THICKER CLOUD COVER. WINDS WILL GENERALLY REMAIN LIGHT FROM THE NORTHWEST...WHICH COUPLED WITH 850MB TEMPS HOVERING ARND -10 TO -12 DEG C SHOULD LIMIT HOW COOL TEMPS RADIATE OVERNIGHT. SO HAVE ONLY NUDGED TEMPS DOWN A LITTLE...GENERALLY IN THE SINGLE DIGITS ABOVE ZERO. COULD SEE SOME OF THE TRADITIONALLY COOLER LOCATIONS DIP TO ARND ZERO BY DAYBREAK MON. CONFIDENCE...HIGH. MONDAY THROUGH TUESDAY... 500MB TROUGH AXIS OVER THE GREAT LAKES REGION PUSHES EAST...WITH AN AREA OF WEAK RIDGING ARRIVING MIDDAY MON OVER THE FORECAST AREA. HOWEVER GIVEN THE SEMI-ZONAL FLOW...WHICH IS GENERALLY A MORE PROGRESSIVE SETUP...THE NEXT WAVE CONTINUES TO BE PROGGED FOR ARRIVAL MON LATE AFTN/EVE. LATEST FORECAST GUIDANCE HAS CONTINUED TO SUGGEST THE MID-LVL HEIGHT RISES MAY BE A LITTLE SLOWER TO DEPART THE REGION...WHICH WOULD LIKELY HAVE AN INFLUENCE ON THE WEAK WAVE ARRIVING POSSIBLY LATER. THE MAIN TIMING DOES APPEAR TO BE CONSISTENT WITH JUST AFT 00Z TUE...AND GIVEN THE PREV-DISCUSSED PROGRESSIVE FLOW...SKIES WILL THICKEN RATHER QUICKLY AND CIGS WILL LOWER WITH EASE. LOCAL MODEL INDICATES A SLIGHTLY LATER ARRIVAL AND CLOSER TO 6Z TUE...BUT ALSO IS INDICATING THE WAVE WILL BE WEAKENING UPON ARRIVAL. CONFIDENCE ON THIS WAVE WEAKENING AS IT ARRIVES IS VERY LOW...GIVEN THE DECENT MID-LVL FORCING ASSOCIATED. TEMPS CONTINUE TO BE COOL ENOUGH TO SUPPORT LGT SNOW FOR THE AREA...AND EXPECT SLR ARND 15:1 TO 18:1. THIS WILL LIKELY PRODUCE A QUICK 1 TO 2 INCHES OF SNOWFALL ACROSS MOST OF THE CWFA. BY 12-15Z TUE...THE BULK OF THE WAVE/SNOW WILL BE PUSHING EAST AND COMING TO AN END. THEN FOR TUE...500MB TROUGH AXIS ARRIVES AS AN ARCTIC AIRMASS CONTINUES TO PUSH SOUTH FROM CANADA TOWARDS THE UPPER MIDWEST TUE AFTN. CURRENTLY EXPECT HIGHS TUE TO HOLD IN THE TEENS/LOW 20S...HOWEVER BY TUE NGT THE BOUNDARY WILL BE PUSHING ACROSS THE FORECAST AREA AND TEMPS WILL BE DROPPING TO A FEW DEGREES BELOW ZERO. CONFIDENCE...HIGH. CONFIDENCE IN SNOW ACCUMS MON EVE/OVERNIGHT...HIGH. WEDNESDAY THROUGH SUNDAY... ENSEMBLES AND OPERATIONAL SOLUTIONS HAVE CONTINUED TO BE IN GOOD AGREEMENT WITH THE ARRIVAL OF YET ANOTHER ARCTIC AIRMASS. BY WED THE 500MB TROUGH AXIS WILL BE OVERHEAD. CURRENT PROGS INDICATE TEMPS IN MID-LVLS WILL HOVER ARND -20 TO -25 DEG C. WHEN APPLYING THIS TOWARDS LOCAL CLIMATE WHICH LIKELY YIELD HIGH TEMPS WED IN THE SINGLE DIGITS ABOVE ZERO TO POSSIBLY THE LOW TEENS. SFC RIDGE WILL BE SLIDING OVER THE AREA AS WELL...WHICH SHOULD LIMIT HOW MUCH LOWER WIND CHILL VALUES WILL BE WED. THEN FOR WED NGT...FLOW GRADUALLY TURNS WESTERLY IN THE LLVLS. A WEAK SHORTWAVE IS PROGGED TO CLIP THE NORTHERN GREAT LAKES REGION...HOWEVER EXPECT GENERALLY DRY WEATHER FOR THE FORECAST AREA WED/WED NGT. FOR THE REMAINDER OF THE EXTENDED PERIODS...ENSEMBLES REMAIN IN DECENT AGREEMENT WITH YET ANOTHER SFC RIDGE SLIDING SOUTHEAST FROM CENTRAL CANADA TOWARDS THE PLAINS AND STRETCHING EAST TO THE WESTERN GREAT LAKES THUR. THIS SHOULD HELP TO MAINTAIN UNSEASONABLY COLD CONDS FOR THE FORECAST AREA...WITH TEMPS STRUGGLING TO WARM BEYOND THE LOW/MID TEENS THUR AFTN. STRONG VORTEX BEGINS TO LIFT NORTHEAST THUR NGT/FRI...WITH SOME MODERATION TO TEMPS POISED FOR THE END OF THE WEEK INTO THE FIRST HALF OF NEXT WEEKEND. ALTHOUGH THIS IS RELATIVE...AS TEMPS WILL CONTINUE TO BE UNSEASONABLY COOL IN THE TEENS/LOW 20S. GUIDANCE IS SUGGESTING THE SOUTHERN STREAM WILL BECOME ACTIVE YET AGAIN IN THE LATER PERIODS...AND INDICATES THE PRECIP WILL REMAIN SOUTH OF THE CWFA. ALTHOUGH COULD SEE SOME ADJUSTMENTS TO THE PLACEMENT OF EACH SOUTHERN STREAM WAVE. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * NONE //DISCUSSION...UPDATED 12Z... A RIDGE OF HIGH PRESSURE EXTENDS FROM THE NORTHERN PLAINS INTO CENTRAL ILLINOIS EARLY THIS MORNING AND WILL REMAIN RELATIVELY STATIONARY THROUGH THE FORECAST PERIOD PROVIDING QUIET WEATHER WITH VFR CONDITIONS AND WNW WINDS. A FEW GUSTS INTO THE HIGH TEENS TO AROUND 20 KT ARE POSSIBLE THIS AFTERNOON AND EARLY EVENING...THEN SHOULD TAPER MID TO LATE IN THE EVENING. THE NEXT CHANCE FOR ANY SIGNIFICANT WEATHER IMPACTS APPEARS TO BE MONDAY NIGHT INTO TUESDAY WHEN SNOW WILL MOVE ACROSS THE AREA WITH LIGHT ACCUMULATIONS POSSIBLE. //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH BMD //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...SNOW LIKELY WITH LIGHT ACCUMULATIONS POSSIBLE. TUESDAY THROUGH SATURDAY...VFR LIKELY. BMD && .MARINE... 302 AM CST MODERATE WEST TO NORTHWEST WINDS ARE EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK ACROSS LAKE MICHIGAN ON THE EASTERN PERIPHERY OF A STRONG RIDGE THAT EXTENDS FROM THE CANADIAN ROCKIES INTO THE OHIO VALLEY. WINDS WILL GENERALLY BE IN THE 20 TO 30 KT RANGE THROUGH TUESDAY...THEN A SERIES OF LOWS WILL DROP FROM CANADA INTO THE GREAT LAKES REGION...THE STRONGEST OF WHICH WILL BE WEDNESDAY NIGHT. A SURGE OF ARCTIC AIR WILL OVERSPREAD THE WESTERN LAKES BEHIND THIS LOW AND A PERIOD OF NORTHWESTERLY GALES IS POSSIBLE...ALONG WITH FREEZING SPRAY. THE RIDGE WILL START TO BUILD CLOSER TO LAKE MICHIGAN LATER IN THE WEEK AND INTO THE WEEKEND WITH WINDS DIMINISHING. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 540 AM CST Sun Feb 23 2014 .DISCUSSION... ISSUED 330 AM CST Sun Feb 23 2014 SHORT TERM...Today through Wednesday night Surface cold front has pressed south of the Ohio River into nw AR while 1042 mb arctic high pressure over Alberta was nosing into the central and northern plains. Colder air easing south into central IL early this morning with temps slipping through the 20s over central IL and low to mid 30s in southeast IL. Temps as cold as 19F at Galesburg and Lacon. Frontogenetic forecasting close to 850 mb boundary near I-70 had band of light snow that diminished east into central IN past few hours with dusting to as much as 1 inch between I-72 and I-70. Will carry just slight chance of light snow this morning over southeast IL per HRRR model run. Radar mosaic shows light pcpn returns and mainly virga over northern MO into nw counties. RUC & HRRR keeps most of this very light snow west of central IL this morning but could be a few flurries this morning into central IL. Clouds to decrease from the north during the afternoon and linger longest in southeast IL. Much colder highs today range from mid 20s from Peoria and Bloomington north to 35-40F over southeast IL with Lawrenceville near 40F. Arctic high pressure noses into the mid MS river valley tonight and brings fair skies and cold lows of 5-10F from Lincoln north and mid to upper teens in southeast IL. Clouds increase Monday morning ahead of northern stream clipper system which digs into the Midwest Monday night. Slowed down chances of light snow Monday afternoon as central IL appear dry through sunset Monday with best chances of light snow arriving Monday night northern half of CWA. Generally less than 1 inch of snow with northern IL having as much as 1-2 inches of snow possible. Highs Monday again in mid 20s north and mid to upper 30s in southeast IL. Lows Monday night in the teens central IL and lower 20s southeast IL. Chances of light snow ne of central IL by Tuesday morning. Highs Tue range from lower 20s northern areas to mid 30s in southeast IL. Core of arctic high pressure settles into MO by 18Z/noon Wed and brings even colder air into the region during middle of the week. Lows overnight Tue night into early Wed morning could reach zero to 5 below nw of IL river with single digit lows over much of central IL and far southeast IL around 10F. Highs Wed in the mid teens ne to lower 20s sw and se areas. Lows Wed night again in the single digits over northern half of CWA and lower teens south. LONG TERM...Thursday through Saturday night Temps modify slightly during end of week but still average below normal through next weekend. The 8-14 day outlook for Mar 2-8 has 60-70% chance of below normal temperatures and 40% chance of above normal precipitation, which has been the normal for this winter. Generally dry and cold conditions expected late this week into next weekend. Though ECMWF and GEM models show some light qpf Friday while heavier qpf passes south of IL Friday. GFS model is dry over IL on Friday. Stayed close to ALLblend pops late this week and into the weekend which is dry. 07 && .AVIATION... ISSUED 540 AM CST Sun Feb 23 2014 VFR conditions will prevail at all TAF sites next 24hrs. Mid clouds around 9kft will overspread all sites this morning and remain over the area/sites through the morning and into the afternoon. Models indicate that the clouds will slide south away from the TAF sites this afternoon, but satellite loop/trends show clouds moving due east. So will keep at least BKN mid clouds over the area into this evening. Then skies will clear around midnight. Winds will be northerly to start and then shifts to northwesterly as a high pressure ridge pushes into the area late this afternoon and into the evening. Auten && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
528 AM CST SUN FEB 23 2014 .UPDATE... ISSUED AT 516 AM CST SUN FEB 23 2014 RADAR TRENDS THE PAST SEVERAL HOURS SHOW A SLOW WEAKENING OF RETURNS ACROSS NORTHERN MISSOURI. KSTJ AND KCNK HAVE BEEN THE ONLY OBSERVATION SITES THAT HAVE REPORTED ANY SNOW. RAP MODEL TRENDS CONTINUE TO SHOW A SUBSTANTIAL DRY LAYER BELOW 850MB IN THE FORECAST SOUNDINGS. A COUPLE OF FLURRIES CANNOT BE RULED OUT SOUTH OF A KTVK TO KMQB LINE EARLY THIS MORNING. BASED ON RADAR TRENDS...A DRY FORECAST STILL LOOKS REASONABLE. && .SYNOPSIS... ISSUED AT 300 AM CST SUN FEB 23 2014 06Z SFC ANALYSIS HAS A FRONTAL BOUNDARY FROM THE OHIO VALLEY INTO THE SOUTHERN PLAINS. A WEAK TROF RAN THROUGH THE GREAT LAKES WHILE HIGH PRESSURE WAS OVER THE NORTHERN PLAINS. DEW POINTS WERE IN THE SINGLE DIGITS AND TEENS FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST WITH 20S AND 30S FROM THE SOUTHERN GREAT LAKES AND OHIO VALLEY INTO THE REMAINDER OF THE PLAINS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CST SUN FEB 23 2014 THE NEXT WEAK DISTURBANCE ALOFT IS MOVING FROM THE PLAINS INTO THE LOWER MISSOURI VALLEY. ALTHOUGH RADAR RETURNS LOOK IMPRESSIVE...NO REPORTING STATION INDICATES PRECIPITATION REACHING THE GROUND. FORECAST SOUNDINGS INDICATE A VERY DRY ATMOSPHERE WILL REMAIN IN PLACE ACROSS THE AREA TODAY AND TONIGHT AS HIGH PRESSURE SLOWLY BUILDS INTO THE MIDWEST. AT THE VERY WORST A FEW FLURRIES MIGHT BE SEEN ACROSS THE EXTREME SOUTHERN AREAS EARLY THIS MORNING. OTHERWISE DRY CONDITIONS WILL BE SEEN ACROSS THE AREA TODAY AND TONIGHT. TEMPERATURES WILL AVERAGE BELOW NORMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 300 AM CST SUN FEB 23 2014 CONTINUED VERY COLD WITH NEAR RECORD LOW TEMPERATURES WITH LIGHT SNOW LIKELY MANY AREAS ON MONDAY. OVERVIEW...LITTLE SENSIBLE WEATHER ISSUES BESIDES LIGHT SNOW AND FLURRIES WITH NEXT INFUSION OF ARCTIC AIR ARRIVING ON MONDAY. LOW LEVEL THERMAL AND MOISTURE FIELDS SUGGESTS A 70/30 MIX OF HI-RES ECMWF WITH GFS. DEEP NW CYCLONIC FLOW KEEPS ARCTIC AIR IN PLACE DAYS 2 THROUGH 7 WITH LITTLE SENSIBLE WEATHER ISSUES. LOW LEVEL THERMAL FIELDS SUPPORT NEAR RECORD TO RECORD LOW MINS WEDNESDAY AM AND POSSIBLY AGAIN TOWARD FRIDAY DEPENDING ON HIGH PRESSURE TRACKS. MONDAY...UPPED POPS TO LIKELY...MOSTLY MONDAY EVENING WITH CENTRAL 1/3 OR MORE OF FORECAST AREA TO RECEIVE 2 TO 3 HOURS OF LIGHT SNOW AS WEAK DISTURBANCE PASSES. LOCAL TOOLS AND TECHNIQUES SUGGEST .5 TO LOCALLY NEAR 1 INCH OF A POWDERY DRY SNOW WITH LWE OF 20:1 OR MORE. FAR NORTH AND SOUTH SECTIONS MAY RECEIVE MORE OF A DUSTING OF FLURRIES. TEMPERATURES IN THE TEENS NORTH TO MID/UPPER 20S FAR SOUTH SECTIONS. MONDAY NIGHT...LOWS AS A CHALLENGE AS CLEARING SHOULD OCCUR AFTER MIDNIGHT NW TO NEAR DAYBREAK SE SECTIONS. HENCE...MINS NEAR ZERO ARE SUGGESTED TO MID TEENS SE SECTIONS. LATER SHIFTS MAY NEED TO CHANGE THESE VALUES BY 5+ DEGREES IF CLEARING IS EARLIER OR DELAYED. TUESDAY...MUCH COLDER AIR TO RESULT IN NEARLY STEADY TEMPERATURES WITH NW WINDS OF 10 TO 20 MPH TO KEEP WIND CHILLS IN SINGLE DIGITS SE TO NEGATIVE SINGLE DIGITS NW SECTIONS DESPITE FAIR SKIES. TUESDAY NIGHT...WINDS TO BECOME NEARLY CALM TOWARD DAYBREAK WITH STRONG AND SHALLOW INVERSION. LOWS SHOULD BE NEAR OR BREAK RECORDS AS DESCRIBED IN CLIMATE SECTION BELOW. THIS SUPPORTS -13 TO +4 SE WITH FAVORED LOCATIONS MAY NEED TO TRIMMED EVEN FURTHER BY 2 TO 5 DEGREES IF SEVERAL HOURS OF CALM TO NEARLY CALM WINDS AND CLEAR SKIES OCCUR. THIS MAY RESULT IN WIND CHILLS WELL BELOW -20 DEGREES INTO LATE MORNING. WEDNESDAY THROUGH SATURDAY...CONTINUED QUITE COLD AND FAIR TO MOSTLY FAIR AND GENERALLY DRY WITH LOWS WELL BELOW NORMAL BY 15 TO 20 DEGREES. THIS SUPPORTS HIGHS MOSTLY IN THE TEENS WITH SOME UPPER SINGLE DIGITS POSSIBLE NORTH AND LOWS SINGLE DIGITS AND POSSIBLY WELL INTO THE NEGATIVE SINGLE DIGITS NORTH SECTIONS. NEXT WAVE OFF CALIFORNIA MAY REQUIRE ADDING SNOW FRIDAY NIGHT AND ESPECIALLY SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 516 AM CST SUN FEB 23 2014 VFR CONDITIONS WILL BE SEEN THROUGH 12Z/24 AS A WEAK DISTURBANCE MOVES ACROSS MISSOURI AND HIGH PRESSURE BUILDS SOUTH FROM CANADA. && .CLIMATE... ISSUED AT 300 AM CST SUN FEB 23 2014 RECORD LOWS FOR FEBRUARY 26... MOLINE.........-14 IN 1963 CEDAR RAPIDS...-08 IN 1950 DUBUQUE........-10 IN 1980 BURLINGTON.....-11 IN 1950 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...08 SHORT TERM...08 LONG TERM...NICHOLS AVIATION...08 CLIMATE...NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
850 AM MST SUN FEB 23 2014 .UPDATE... ISSUED AT 850 AM MST SUN FEB 23 2014 ENTIRE FORECAST AREA ENTRENCHED IN STRATUS THIS MORNING WITH EAST/NORTHEAST WINDS EAST OF THE CO/KS BORDER AND SOUTHEAST WINDS ACROSS FAR EASTERN COLORADO. FOG ALSO BEING REPORTED ACROSS THE WESTERN 2/3 OF THE AREA WITH LOCALLY DENSE FOG IN THE GOODLAND AREA. LATEST RUC HAS AN EXCELLENT GRASP OF THE STRATUS AND PER THE 12Z RUN KEEPS IT OVER THE AREA FOR THE ENTIRE DAY. THE HRRR BREAKS UP THE STRATUS OVER PARTS OF FAR EASTERN COLORADO BUT KEEPS IT OVER THE REST OF THE AREA THROUGH THE DAY AS WELL. SHOULD THESE SCENARIOS VERIFY TEMPERATURES WONT MOVE MUCH FROM WHERE THEY ARE NOW AND WOULD BE SEVERAL DEGREES BELOW PREVIOUS FORECAST. 12Z NAM BOUNDARY LAYER RH ALSO HAD A GOOD HANDLE ON AREAL COVERAGE OF STRATUS BUT BY 18Z LIFTS IT/DISSIPATES IT FROM SOUTH TO NORTH ALLOWING MORE HEATING AND WARMER TEMPERATURES THAN THE RUC/HRRR. FOR THE FIRST OF WHAT WILL LIKELY BE SEVERAL UPDATES HAVE TRENDED TOWARD THE RUC/HRRR GIVEN THE EASTERLY COMPONENT TO THE WINDS ALL DAY WHICH ISNT REAL FAVORABLE FOR RAPID STRATUS DISSIPATION AS THE NAM WOULD SUGGEST. HAVE LOWERED HIGH TEMPERATURES TO THE MID/UPPER 20S ACROSS THE NORTHEAST AND EAST (WHERE LOW CLOUDS EXPECTED LONGER) AND LOW TO MID 30S ACROSS THE FAR SOUTH THROUGH SOUTHWEST AND WEST WHERE SOME DISSIPATION WOULD BE MOST LIKELY BUT NOT CERTAIN AT THIS POINT. HAVE ALSO BEEFED UP THE FOG PER LOCAL OBSERVATIONS. NONE OF THE MODELS HANDLING THIS VERY WELL...HOPEFULLY THE 15Z RUC WILL LATCH ON TO IT AND GIVE SOME BETTER GUIDANCE. MORE UPDATES LIKELY TO COME LATER. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 314 AM MST SUN FEB 23 2014 UPPER FLOW WILL BE NORTHWEST THROUGH TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL BE OVER THE REGION TODAY AND TONIGHT. HIGH PRESSURE WILL DRIFT EAST MONDAY AS LOW PRESSURE MOVES INTO EASTERN COLORADO. A COLD FRONT WILL PUSH SOUTH MONDAY NIGHT FOLLOWED BY HIGH PRESSURE TUESDAY AND TUESDAY NIGHT. CURRENT RADAR SHOWING DECREASING TREND OF SNOW RETURNS OVER THE NORTH IN THE CURRENT WINTER WEATHER ADVISORY. FRONTOGENESIS EXITS THE AREA AND DO NOT EXPECT ANYTHING MORE THAN LIGHT SNOW THIS MORNING AND EVEN LESS OF AN AREA THIS AFTERNOON AS DYNAMICS MOVE OUT OF THE AREA. PLAN TO CANCEL THE WINTER WEATHER ADVISORY AT ZONES ISSUANCE. DEWPOINT DEPRESSIONS ARE NARROWING TO LESS THAN 3 DEGREES AND BOUNDARY LAYER RH IS PROGGED TO INCREASE TO OVER 90 PERCENT SO HAVE INCLUDED SOME PATCHY FREEZING FOG THIS MORNING OVER ALL BUT THE NORTHEAST FA. FORECAST SOUNDINGS ACROSS THE FA TONIGHT INDICATE THE POSSIBILITY OF SOME STRATUS AND FOG BUT MOISTURE IS TOO SHALLOW TO INDICATE FREEZING DRIZZLE. PLAN TO PULL THE FREEZING DRIZZLE AND CONSIDER SOME MENTION OF FOG OVERNIGHT INTO MONDAY MORNING. POPS WILL BE NIL MONDAY DUE TO SUBSIDENCE AND LACK OF MOISTURE. THERE IS SOME WEAK FORCING ACROSS THE NORTHERN ZONES MONDAY NIGHT/TUESDAY MORNING AND MOISTURE INCREASES SO CANNOT RULE OUT A SLIGHT CHANCE OF LIGHT SNOW OR FLURRIES. FOR TUESDAY AFTERNOON/TUESDAY NIGHT...THE GFS IS FASTER WITH BRINGING DYNAMICS INTO THE FA THAN THE NAM. FOR NOW WILL OPT FOR THE GFS TO STAY CONSISTENT WITH SURROUNDING OFFICES. HOWEVER DUE TO THE TIMING DIFFERENCES WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE RANGE. MAX TEMPERATURES TODAY WILL BE IN THE MID 30S EXCEPT FOR WESTERN PORTIONS OF EASTERN COLORADO WHERE SOME LOWER 40S WILL BE POSSIBLE. TEMPERATURES WILL WARM INTO THE 40S WITH SOME MID 50S POSSIBLE IN THE SOUTHWEST PORTION OF THE FA. TUESDAY WILL BE COLDER BEHIND THE FRONT WITH READINGS IN THE UPPER 20S AND LOW 30S. MIN TEMPERATURES TONIGHT WILL FALL INTO THE LOWER 20S AND INTO THE TEENS MONDAY AND TUESDAY NIGHTS. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 236 AM MST SUN FEB 23 2014 A RETURN OF BELOW NORMAL TEMPERATURES WILL BE THE MAIN CHARACTERISTIC OF THE EXTENDED FORECAST WITH A FEW PERIODS OF SNOW POSSIBLE. MODELS INDICATE THAT NORTHWEST FLOW IS THE PRIMARY UPPER LEVEL PATTERN ACROSS THE TRI-STATE AREA WITH A LARGE TROUGH OVER THE EASTERN UNITED STATES AND A RIDGE TO THE WEST. WITH THIS PATTERN IN PLACE...THE GATE IS OPEN FOR COLD CANADIAN AIR TO MOVE IN. THIS PATTERN IS SIMILAR TO THE EXTENDED VERY COLD OUTBREAK OBSERVED EARLIER THIS MONTH. THE COLD WEATHER IS NOT EXPECTED TO REACH THAT EXTENT AGAIN BUT WELL BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED. THE FORECAST INITIALIZATION PROCEDURE PROVIDED TEMPERATURES THAT SEEMED UNREASONABLY WARM FOR THIS TYPE OF PATTERN. THE EUROPEAN SEEMS MOST REASONABLE AND IS SUPPORTED BY THE CANADIAN MODEL. THE OPERATIONAL GFS HAS 850 MB TEMPS IN THE SAME BALLPARK AS THE EUROPEAN HOWEVER MEX GUIDANCE IS 10 TO NEARLY 20 DEGREES WARMER FOR FRIDAY AND SATURDAY. AS A RESULT...TEMPERATURES WERE NUDGED DOWN A FEW DEGREES BUT FORECAST IS STILL PROBABLY TOO WARM. AS FOR PRECIPITATION...THERE ARE TWO CHANCES AT WINTRY PRECIP DURING THE EXTENDED PERIOD. FOR WEDNESDAY...THE UPPER LEVEL DISTURBANCE THAT WILL BRING SNOW FOR TUESDAY NIGHT SHOULD BE CLEAR OF THE REGION WITH HIGH PRESSURE BUILDING IN. ADVERTISED DRY CONDITIONS FOR WEDNESDAY BUT A FEW FLURRIES MAY LINGER DEPENDING ON SPEED AND MOVEMENT OF THIS SYSTEM. THE FIRST CHANCE FOR PRECIPITATION IN THE EXTENDED FORECAST IS ANTICIPATED ON THURSDAY NIGHT INTO FRIDAY. THIS CHANCE COMES AS A STRONGER DISTURBANCE IN THE NORTHWEST FLOW TRANSITIONS ACROSS THE REGION. MODELS DISAGREE SOMEWHAT IN THE PLACEMENT AND MOVEMENT OF THIS SYSTEM SO HAVE ONLY GONE SLIGHT CHANCE TO LOW CHANCE POPS FOR THURSDAY NIGHT. DUE TO THE SPEED OF THIS SYSTEM...AN EXTENDED PERIOD OF ACCUMULATING SNOW IS NOT EXPECTED. IT IS ALSO POSSIBLE THIS SYSTEM MOVES SOUTH OF THE AREA WITH NO SNOW AS THE BEST FORCING APPEARS TO REMAIN SOUTH. THE SECOND...MORE SIGNIFICANT CHANCE OF PRECIPITATION COMES FOR NEXT WEEKEND. THROUGH 00Z SATURDAY...THE EUROPEAN...CANADIAN AND GFS MODELS ARE IN DECENT AGREEMENT ON A 500 MB LOW COMING INTO CALIFORNIA. THE GFS AND EUROPEAN MODELS THEN BRING THIS SYSTEM ACROSS THE ROCKIES ON SATURDAY AND INTO THE HIGH PLAINS SUNDAY. THESE TYPES OF SYSTEMS ARE TYPICALLY RESPONSIBLE FOR LARGER SNOW AMOUNTS SO WILL NEED TO MONITOR THIS SYSTEM CLOSELY. AS WITH ANY EXTENDED FORECAST...MODELS CAN AND OFTEN DO CHANGE THEIR SOLUTIONS THIS FAR OUT. HOWEVER...WITH BOTH MODELS PICKING UP ON IT AND PROJECTING A SIMILAR SOLUTION...THIS MAY HAVE A LITTLE MORE WEIGHT TO IT THAN A TYPICAL EXTENDED FORECAST STORM. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 438 AM MST SUN FEB 23 2014 SOME IFR AND LIFR CONDITIONS WILL CONTINUE THIS MORNING AT KGLD AND KMCK BEHIND AN EXITING SHORTWAVE. CONDITIONS SHOULD IMPROVE TO MVFR AT KGLD THIS AFTERNOON BUT WILL DROP BACK DOWN TO IFR TONIGHT AS FOG AND STRATUS OVERTAKE THE AREA. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...FS LONG TERM...RRH AVIATION...FS
AREA FORECAST DISCUSSION....CORRECTED
NWS JACKSON MS
400 AM CST SUN FEB 23 2014 .SHORT TERM...TODAY THROUGH MONDAY NIGHT...LOW LEVEL WARM/MOIST ADVECTION IS UNDERWAY ALONG THE GULF COAST THIS MORNING EVIDENT BY INCREASING COVERAGE OF SHOWER AND THUNDERSTORM ACTIVITY ACROSS EASTERN LA/SOUTHERN MS. FURTHER NORTH...AN ADVANCING COLD FRONT IS ANALYZED ON THE NORTHERN FRINGES OF THE TN VALLEY WHICH IS PROGGED TO CROSS THE ARKLAMISS STARTING LATE THIS AFTERNOON. PRIMARY CONCERN FOR TODAY IS THE RISK FOR HEAVY RAINS ALONG THE HWY 98 CORRIDOR...AND THUNDERSTORMS THAT COULD PRODUCE SOME NICKEL TO QUARTER SIZE HAIL ALONG AND SOUTH OF HWY 84. 00Z NMM/ARW/LOCAL WRF OUTPUT SHOW THE AFOREMENTIONED SHOWER/THUNDER ACTIVITY EXPANDING INTO SOUTHERN ZONES BY MID MORNING AND GRADUALLY COMING TO AN END BY LATE AFTERNOON/EARLY EVENING. THE GUIDANCE HAS BEEN CONSISTENT SHOWING MID LEVEL LAPSE RATES CLIMBING INTO THE 6.5-7.5C/KM RANGE SOUTH OF I-20 AS THE LOW LEVEL WARM AIR SURGES IN...WITH SHOWALTER INDICES IN THE -2 TO -4C RANGE INDICATIVE OF ELEVATED CONVECTION POTENTIAL GIVEN RELATIVELY COOL PBL PER BUFR SOUNDINGS. WHILE LOW LEVEL WINDS LOOK TO VEER WESTERLY BY DAYBREAK...A PASSING MID/UPPER LEVEL JET STREAK JUST TO OUR NORTH WILL PROVIDE NEEDED ASCENT FOR CONVECTION AS THE RIGHT ENTRANCE REGION OF THIS FEATURE PASSES. A FEW DEEPER THUNDERSTORM CORES SEEM REASONABLE GIVEN THE SYNOPTIC SETUP AND WILL KEEP THE MENTION OF SOME QUARTER SIZE HAIL IN THE HWO FOR TODAY. OF EQUAL (IF NOT GREATER) CONCERN IS THE POTENTIAL FOR SOME LOCALLY HIGH RAINFALL TOTALS ALONG HWY 98 COME LATE AFTERNOON. LOCAL WRF OUTPUT SHOWS A SWATH OF 3-5 INCHES ACROSS MARION/LAMAR/FORREST COUNTIES BETWEEN 12Z AND 22Z...WHILE THE HI-RES NMM/ARW SHOW SIMILARLY ALARMING TOTALS OF ANYWHERE FROM 2-4 INCHES DURING THE SAME TIME. GIVEN PW VALUES CLIMBING NEAR/JUST ABOVE 1.5 IN ACROSS THIS AREA BY MID DAY (RIGHT AT THE 99TH PERCENTILE FOR FEB) AND THE CONVECTIVE NATURE OF THE ACTIVITY THESE KINDS OF TOTALS SEEM QUITE REASONABLE. THE BIGGEST QUESTION MARK IS JUST WHERE IS THE HEAVIEST AXIS GOING TO SET UP. THE HRRR HAS BEEN TOYING WITH THE BEST AXIS REMAINING CLOSER TO THE COAST ON A FEW RUNS...BUT SHOWS 2-3 IN ALONG/SOUTH OF HWY 98 ON OTHERS. GIVEN THE HEAVY RAINS WE SAW ACROSS THIS AREA A COUPLE DAYS AGO AND THE COINCIDENT HEAVY RAIN AXIS SHOWN IN THE HI-RES ARW/NMM/LOCAL WRF FEEL THE RISK FOR FLASH FLOODING IS GREAT ENOUGH TO WARRANT A FLASH FLOOD WATCH THROUGH 22Z. BY EARLY EVENING THE BETTER FORCING WILL SHIFT EAST WHICH WILL SHUNT DEEPER CONVECTION AND ASSOCIATED HEAVY RAIN RISK EAST AS WELL. OTHER THAN SOME LIGHT SHOWER ACTIVITY SOUTH OF I-20 THE OVERNIGHT HOURS LOOK PRETTY QUIET AS THE COLD FRONT CROSSES THE REGION. QUIET CONDITIONS LOOK TO PREVAIL THROUGH MONDAY NIGHT...ALTHOUGH IT`S NOT COMPLETELY OUT OF THE QUESTION THAT A FEW LIGHT SHOWERS COULD DEVELOP ACROSS THE DELTA EARLY TUE MORNING AS A JET STREAK IN THE PERSISTENT WESTERLY FLOW ALOFT NOSES IN. AS FOR TEMPS/POPS...LOWERED MAV GUIDANCE FOR THIS AFTERNOON ACROSS SOUTHEASTERN AREAS GIVEN THE HIGH CHANCES FOR RAIN/CLOUDS THROUGH THE DAY. ALSO RAISED OVERNIGHT LOWS FOR TUE MORNING TOWARD THE WARMER NAM/ECMWF MOS NUMBERS AND RAW GFS OUTPUT. POPS FOR TODAY WERE RAISED QUITE A BIT NEAR HBG. /BK/ .LONG TERM...TUESDAY THROUGH SUNDAY...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR THE WORK WEEK WITH NEAR NORMAL TEMPERATURES RETURNING FOR THE WEEKEND. RAIN WILL SPREAD ACROSS THE CWA TUESDAY ASSOCIATED WITH A SFC LOW OVER THE SOUTHERN PLAINS AND A COLD FRONT DROPPING THROUGH THE REGION. THE ECMWF CONTINUES TO GENERATE MORE RAINFALL THAN MODEL CONSENSUS WOULD SUGGEST OVER THE SOUTHERN PORTION OF OUR CWA WHERE MORE THAN AN INCH TOTAL COULD FALL BY WEDNESDAY MORNING. THE ARCTIC AIR WILL BE FILTERING INTO OUR CWA TUESDAY NIGHT AS THE RAIN ENDS FROM THE NORTHWEST. THE LIGHT RAIN LOOKS TO MIX WITH OR BRIEFLY CHANGE OVER TO LIGHT SNOW BEFORE ENDING EARLY WEDNESDAY MORNING ALONG THE HIGHWAY 82 CORRIDOR. TEMPERATURES WILL REMAIN ABOVE FREEZING AND BOTTOM OUT IN THE MID 30S ALONG THE HIGHWAY 82 CORRIDOR SO NO ACCUMULATION ON ROADWAYS IS CURRENTLY ANTICIPATED. NO SIGNIFICANT PRECIPITATION IS EXPECTED AFTER SUNRISE WEDNESDAY. THE STRONG CAA WILL HOLD HIGH TEMPERATURES IN THE 40S ACROSS MUCH OF THE NORTHERN HALF OF THE AREA. THE ASSOCIATED SURFACE HIGH WILL BECOME CENTERED OVER OUR CWA WEDNESDAY NIGHT AND THEN SHIFT EAST OF OUR CWA THURSDAY AFTERNOON. THIS WILL SET UP THE COLDEST MORNING OF THE FORECAST PERIOD THURSDAY MORNING WHERE LOWER 20S WILL BE COMMON IN THE NORTH TO AROUND 30 DEGREES IN THE SOUTH. DRY WEATHER WILL CONTINUE THURSDAY BUT A DISTURBANCE WILL DROP OVER THE SOUTHERN PLAINS THURSDAY NIGHT AND HELP DEVELOP A SURFACE LOW. WAA AHEAD OF THIS SYSTEM WILL BRING RAIN BACK INTO OUR WESTERN ZONES THURSDAY NIGHT. THE ECMWF IS FASTER THAN THE GFS AND ENSEMBLES BUT CONSENSUS BRINGS THE SHORTWAVE AND SFC LOW OVER OUR WESTERN ZONES BY FRIDAY EVENING AND SHIFT THE SYSTEM EAST OF OUR CWA SATURDAY. DRY WEATHER LOOKS TO RETURN SATURDAY AND LAST THROUGH MUCH OF SUNDAY. ANOTHER DISTURBANCE WILL DROP OVER THE SOUTHERN PLAINS SUNDAY AND INCREASE OUR RAIN CHANCES AGAIN SUNDAY NIGHT. /22/ && .AVIATION...MVFR CIG WL LIKELY IMPACT AREAS ALONG/S OF I-20 EARLY THIS MORNING BEFORE VFR CIG TRY AND RETURN AFTER 15Z OR SO. ONLY EXCEPTION MAY VERY WELL BE NEAR HBG/PIB WHERE PERSISTENT SHRA/TSRA BRING AT LEAST INTERMITTENT MVFR/IFR CIG AND VSBY THRU MOST OF THE DAYLIGHT HRS. THE HEAVY RAINS NEAR HBG/PIB WL COME TO AN END BY EARLY EVENING AS THIS ACTIVITY PUSHES E. A COLD FRONT WL START CROSSING THE ARKLAMISS FROM THE N AROUND 22Z PASSING THRU THE PIB/HBG AREA AROUND 06-08Z TONIGHT. NLY WINDS WL BECOME A BIT GUSTY IN WAKE OF THE FRONT...BUT LIGHTER WINDS WL RETURN DURING THE DAY MON. /BK/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 73 46 60 48 / 31 13 0 5 MERIDIAN 74 47 63 46 / 35 13 0 6 VICKSBURG 73 44 58 47 / 26 11 0 5 HATTIESBURG 70 55 67 50 / 90 16 0 9 NATCHEZ 70 49 59 49 / 39 17 0 7 GREENVILLE 69 36 55 42 / 7 7 0 7 GREENWOOD 74 38 55 43 / 7 8 0 4 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR MSZ072>074. LA...NONE. AR...NONE. && $$ BK/22/BK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
630 AM CST SUN FEB 23 2014 .UPDATE... ISSUED AT 625 AM CST SUN FEB 23 2014 JUST GOT A REPORT OF 6 INCHES SNOWFALL IN OGALLALA. ADDITIONAL SNOWFALL THIS MORNING WOULD LIKELY PUT THAT COUNTY IN THE 6 INCHES IN 12 HOUR CRITERIA. AN ADDITIONAL 2 INCHES WOULD PUT THEM IN THE 8 INCHES IN 24 HOUR CRITERIA. A WARNING HAS BEEN ISSUED FOR THAT COUNTY. UPDATE ISSUED AT 538 AM CST SUN FEB 23 2014 THE METAR AT KOGA IS SHOWING 1 MILE VSBY WITH MODERATE SNOW. THE NEDOR CAMS IN DEUEL COUNTY SHOW SIGNIFICANT ON THE GROUND AND STILL FALLING AS THE SECOND DISTURBANCE OPERATES ON THE CHEYENNE DIVIDE THIS MORNING. GIVEN THE 8 PM 5 INCH SNOWFALL REPORT FROM THE COOP OBSERVER AT BIG SPRINGS...WINTER STORM CONDITIONS ARE LIKELY UNDERWAY IN DEUEL COUNTY. SO A WINTER STORM WARNING HAS BEEN ISSUED FOR THAT COUNTY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CST SUN FEB 23 2014 ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE WINTER WEATHER ADVISORY CONTINUES THIS MORNING. AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY BAND OF SNOW IS WEAKENING. THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1 RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT. THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2 INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS. THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF 17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13 TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO 1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE. THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE FOR THE NORTH TONIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN FEB 23 2014 MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST. HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES WOULD BE WARRANTED. THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT. WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST HOLD STEADY FOR THE EARLY MORNING HOURS. SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE 30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE. REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST. THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 513 AM CST SUN FEB 23 2014 VFR IS EXPECTED ALONG AND EAST OF HIGHWAY 183 TODAY. MIXED VFR/IFR IN SNOW AND CIGS IS EXPECTED WEST OF HWY 183. THE ONGOING SNOW ACROSS WRN NEBRASKA IS EXPECTED TO CONTINUE THIS MORNING AND LIFT SLOWLY NORTH INTO NRN NEB THIS AFTERNOON. TONIGHT IT IS EXPECTED TO MOVE EAST THROUGH NRN NEB. IFR SHOULD BE FAIRLY WIDESPREAD IN THIS AREA OF SNOW WITH CONDITIONS WORSENING WESTWARD. MVFR CIGS ARE EXPECTED ELSEWHERE TONIGHT BUT THIS COULD TURN OUT TO BE VFR AT OVC035-040 AS THE MODEL CONSENSUS COULD BE FORECASTING CIG HEIGHTS TOO LOW. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ022>025-035>038-058-059-071. WINTER STORM WARNING UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ056- 057-069-070. && $$ UPDATE...CDC SHORT TERM...CDC LONG TERM...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
546 AM CST SUN FEB 23 2014 .UPDATE... ISSUED AT 538 AM CST SUN FEB 23 2014 THE METAR AT KOGA IS SHOWING 1 MILE VSBY WITH MODERATE SNOW. THE NEDOR CAMS IN DEUEL COUNTY SHOW SIGNIFICANT ON THE GROUND AND STILL FALLING AS THE SECOND DISTURBANCE OPERATES ON THE CHEYENNE DIVIDE THIS MORNING. GIVEN THE 8 PM 5 INCH SNOWFALL REPORT FROM THE COOP OBSERVER AT BIG SPRINGS...WINTER STORM CONDITIONS ARE LIKELY UNDERWAY IN DEUEL COUNTY. SO A WINTER STORM WARNING HAS BEEN ISSUED FOR THAT COUNTY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CST SUN FEB 23 2014 ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE WINTER WEATHER ADVISORY CONTINUES THIS MORNING. AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY BAND OF SNOW IS WEAKENING. THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1 RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT. THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2 INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS. THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF 17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13 TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO 1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE. THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE FOR THE NORTH TONIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN FEB 23 2014 MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST. HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES WOULD BE WARRANTED. THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT. WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST HOLD STEADY FOR THE EARLY MORNING HOURS. SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE 30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE. REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST. THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 513 AM CST SUN FEB 23 2014 VFR IS EXPECTED ALONG AND EAST OF HIGHWAY 183 TODAY. MIXED VFR/IFR IN SNOW AND CIGS IS EXPECTED WEST OF HWY 183. THE ONGOING SNOW ACROSS WRN NEBRASKA IS EXPECTED TO CONTINUE THIS MORNING AND LIFT SLOWLY NORTH INTO NRN NEB THIS AFTERNOON. TONIGHT IT IS EXPECTED TO MOVE EAST THROUGH NRN NEB. IFR SHOULD BE FAIRLY WIDESPREAD IN THIS AREA OF SNOW WITH CONDITIONS WORSENING WESTWARD. MVFR CIGS ARE EXPECTED ELSEWHERE TONIGHT BUT THIS COULD TURN OUT TO BE VFR AT OVC035-040 AS THE MODEL CONSENSUS COULD BE FORECASTING CIG HEIGHTS TOO LOW. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ022>025-035>038-057>059-071. WINTER STORM WARNING UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ056- 069-070. && $$ UPDATE...CDC SHORT TERM...CDC LONG TERM...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
514 AM CST SUN FEB 23 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CST SUN FEB 23 2014 ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE WINTER WEATHER ADVISORY CONTINUES THIS MORNING. AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY BAND OF SNOW IS WEAKENING. THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1 RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT. THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2 INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS. THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF 17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13 TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO 1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE. THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE FOR THE NORTH TONIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN FEB 23 2014 MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST. HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES WOULD BE WARRANTED. THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT. WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST HOLD STEADY FOR THE EARLY MORNING HOURS. SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE 30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE. REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST. THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 513 AM CST SUN FEB 23 2014 VFR IS EXPECTED ALONG AND EAST OF HIGHWAY 183 TODAY. MIXED VFR/IFR IN SNOW AND CIGS IS EXPECTED WEST OF HWY 183. THE ONGOING SNOW ACROSS WRN NEBRASKA IS EXPECTED TO CONTINUE THIS MORNING AND LIFT SLOWLY NORTH INTO NRN NEB THIS AFTERNOON. TONIGHT IT IS EXPECTED TO MOVE EAST THROUGH NRN NEB. IFR SHOULD BE FAIRLY WIDESPREAD IN THIS AREA OF SNOW WITH CONDITIONS WORSENING WESTWARD. MVFR CIGS ARE EXPECTED ELSEWHERE TONIGHT BUT THIS COULD TURN OUT TO BE VFR AT OVC035-040 AS THE MODEL CONSENSUS COULD BE FORECASTING CIG HEIGHTS TOO LOW. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ022>025-035>038-056>059-071. WINTER STORM WARNING UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ069- 070. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...CDC
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AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 AM CST SUN FEB 23 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 301 AM CST SUN FEB 23 2014 CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING FROM THE EASTERN PACIFIC INTO ALASKA...A BROAD UPPER LOW OVER THE CANADIAN ARCHIPELAGO...AND BROAD TROUGHING ACROSS ALL OF SOUTHERN CANADA INTO THE UPPER MIDWEST. SHORTWAVES OF NOTE FOR THIS FORECAST INCLUDE ONE OVER WEST CENTRAL BRITISH COLUMBIA...ONE OVER CENTRAL ALBERTA...AND THE LAST AS PART OF THE UPPER LOW ON THE WESTERN SIDE OF THE CANADIAN ARCHIPELAGO. A NORTHWEST 925MB FLOW CONTINUES TO GRADUALLY DRAW COLDER IN OUT OF CANADA TOWARDS THE FORECAST AREA...NOTED BY THE 00Z MPX SOUNDING AT -15C. THAT SAME SOUNDING ALSO CONTINUES TO DEPICT PLENTY OF DRY AIR...RESULTING IN CLEAR SKIES EARLY THIS MORNING. COMBINATION OF THE CLEAR SKIES AND COOLING 925MB TEMPS HAS ALLOWED TEMPERATURES TO DROP INTO THE SINGLE DIGITS ABOVE ZERO. IF THE 5 TO 15 MPH BREEZE WAS NOT PRESENT TO KEEP THE AIR MIXED...TEMPERATURES WOULD PROBABLY BE A LOT COLDER. OVERALL LITTLE CHANGE IS PROGGED BY MODELS TO OCCUR IN THE NEXT 24 HOURS IN TERMS OF THE UPPER LEVEL PATTERN OVER THE UPPER MIDWEST AND THE FORECAST AREA. WE STILL REMAIN UNDER THE INFLUENCE OF A DRY NORTHWEST LOW TO MID LEVEL FLOW...WHICH SHOULD HELP KEEP SKIES MAINLY CLEAR THROUGH TODAY AND MUCH OF TONIGHT. THERE ARE SOME INDICATIONS OF CIRRUS APPROACHING LOCATIONS WEST OF THE MISSISSIPPI RIVER LATE TONIGHT...BUT THATS REALLY ABOUT IT FOR CLOUDS. 925MB TEMPS TODAY ARE FORECAST TO RANGE BETWEEN -13 AND -16C...ABOUT 1-2C COLDER THAN YESTERDAY. THEREFORE...WE SHOULD SEE HIGHS JUST SLIGHTLY COOLER THAN YESTERDAY. SKIES STAYING CLEAR THROUGH MUCH OF TONIGHT PLUS 925MB TEMPS FALLING TO -14 TO -19C...COLDEST OVER WISCONSIN...SHOULD ALLOW FOR LOWS IN MOST LOCATIONS IN THE SINGLE DIGITS BELOW ZERO. AGAIN...THERE LOOKS TO BE A PERSISTENT NORTHWEST BREEZE THROUGH TONIGHT HELPING TO PREVENT DECOUPLING. STILL...THE TYPICAL COLD SPOTS COULD TRY TO APPROACH -10F. WIND CHILLS LOOK TO GET CLOSE TO ADVISORY CRITERIA...BUT TOO MARGINAL AT THIS POINT TO ISSUE AN ADVISORY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 301 AM CST SUN FEB 23 2014 THE 2 MAIN IMPACTS REMAIN FOR THE LONG TERM... 1. POTENTIAL FOR SOME SNOW LATE MONDAY AFTERNOON AND NIGHT 2. THE BITTER COLD AIR...ESPECIALLY TUESDAY NIGHT AND BEYOND. REGARDING IMPACT NUMBER 1...THE SHORTWAVES CURRENTLY OVER CENTRAL BRITISH COLUMBIA AND ALBERTA REMAIN PROGGED TO PHASE TOGETHER OVER THE DAKOTAS ON MONDAY...THEN QUICKLY SLIDE THROUGH THE FORECAST AREA AROUND 06Z TUESDAY. MOISTURE IS LACKING FOR THESE SHORTWAVES...WITH PRECIPITABLE WATER CLIMBING TO 0.1-0.2 OF AN INCH. HOWEVER...SOME WEAK ISENTROPIC LIFT ON THE 275-280K SURFACES COMBINED WITH DPVA AHEAD OF THE SHORTWAVES SHOULD BE ENOUGH TO SQUEEZE OUT SOME LIGHT SNOW. SNOW SHOULD BE SOMEWHAT FLUFFY...THOUGH THE BULK OF THE LIFT LOOKS TO OCCUR ABOVE THE DENDRITIC GROWTH ZONE. TIMING WISE...MODELS CONTINUE TO SLOW DOWN THE SNOW MOVING INTO THE AREA...WITH THE 23.00Z NAM/GFS/CANADIAN/ECMWF KEEPING MUCH OF THE SNOW WEST OF THE AREA PRIOR TO 00Z TUESDAY. ITS MORE OF A MONDAY NIGHT SNOW NOW. DID RAISE CHANCES UP FOR MONDAY EVENING WEST OF THE MISSISSIPPI RIVER WITH GOOD MODEL AGREEMENT FOR THE SNOW THEN. AFTER 06Z MONDAY... MODELS DIVERGE ON HOW MUCH SNOW MIGHT BE LEFT WITH THE 23.00Z GFS/CANADIAN DRY WHEREAS THE NAM AND ECMWF STILL HAVE SOME SNOW LEFT. SPLIT THE DIFFERENCE AND HAVE SOME 20-30 PERCENT CHANCES FOR NOW. IT APPEARS MUCH OF THIS HAS TO DO WITH THE TIMING OF THE PHASED SHORTWAVE. NOW IMPACT NUMBER 2...THE COLD. IN THE WAKE OF MONDAY NIGHTS SHORTWAVE TROUGH...925MB TEMPS FALL TO -15 TO -20C. A SECOND AND MORE POTENT COLD SURGE REMAINS PROGGED TO PLUNGE INTO THE AREA TUESDAY NIGHT...DROPPING 925MB TEMPS TO -23 TO -25C BY 12Z WEDNESDAY. THIS SURGE IS BEHIND THAT SHORTWAVE CURRENTLY OVER THE CANADIAN ARCHIPELAGO. WIND CHILL ADVISORIES SEEM ALL BUT LIKELY TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BOUT OF WARM ADVECTION IS SUGGESTED FOR WEDNESDAY AHEAD OF AN ARCTIC COLD FRONT DROPPING SOUTH OUT OF CANADA...THOUGH IT APPEARS A BRISK WEST WIND WILL ACCOMPANY IT. THEN ITS BACK TO THE COLD AS ANOTHER IMPRESSIVE SURGE OF ARCTIC AIR DIVES SOUTH INTO THE REGION FOR THURSDAY ON SOME BRISK NORTHWEST WINDS. 925MB TEMPS FROM THE 23.00Z GFS AND ECMWF DROP TO -23 TO -27C BY 12Z THURSDAY...WHILE 850MB TEMPS APPROACH -30C ACROSS OUR NORTH. THESE READINGS ARE NEARLY 3 STANDARD DEVIATIONS BELOW NORMAL. BEYOND THURSDAY...MODELS BEGIN TO DIVERGE A BIT WITH THE HANDLING OF THE COLD AIR. THE 23.00Z GFS TRIES TO MODIFY THE COLD AIR SOMEWHAT FROM THE FLOW BECOMING MORE ZONAL ACROSS THE NORTHERN TIER OF THE U.S.. THE 23.00Z ECMWF ALONG WITH EXTRAPOLATION OF THE CANADIAN HAS THAT SAME ZONAL FLOW...JUST A SMIDGE FURTHER SOUTH...WHICH RESULTS IN A CONTINUATION OF THE DEEP FREEZE. FOR THE FORECAST LEANED A BIT CLOSER TOWARDS THE ECMWF. OVERALL FOR TEMPERATURES TUESDAY THROUGH SATURDAY...STAYED CLOSE TO A CONSENSUS OF 30 DAY BIAS CORRECTED GUIDANCE...WHICH PERFORMED WELL IN PAST COLD SPELLS THIS WINTER. THURSDAY NIGHT COULD BE VERY COLD WITH A SURFACE RIDGE PARKED OVERHEAD. WOULD NOT BE SURPRISED IF SOME OF THE TYPICAL COLD SPOTS TO APPROACH -30F. GIVEN HOW DEEP SOME OF THE FROST IS ALREADY...WATER MAINS UNDER ROADS WILL NEED TO BE WATCHED CLOSELY. LUCKILY THE HIGHER SUN ANGLE CAN HEAT THE TOP OF THE ROAD SURFACES MORE NOW THAN IN JANUARY...BUT STILL THIS COLD AIR WILL NOT BE GOOD. THERE ARE STRONG INDICATIONS TOO FROM THE CFS THAT THE BELOW NORMAL WEATHER COULD PERSIST THROUGH ALL OF MARCH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY) ISSUED AT 530 AM CST SUN FEB 23 2014 DRY/COLD CANADIAN HIGH PRESSURE...WITH RIDGING INTO IA...WILL REMAIN CENTERED OVER ALB/SASKAT TODAY/TONIGHT...WITH GOOD VFR CONDITIONS EXPECTED THRU THE PERIOD INTO MONDAY. A MODEST PRESSURE GRADIENT WILL REMAIN OVER THE AREA...FOR WEST TO NORTHWEST WINDS MOSTLY IN THE 10 TO 15 KT RANGE THRU TONIGHT. STEEP LOW LEVEL LAPSE RATES AND SOME DEEPER MIXING TO NEAR 925MB THIS AFTERNOON LOOKS TO RESULT IN SOME GUSTINESS OF THE WINDS THIS AFTERNOON...MAINLY AT THE HIGHER ELEVATION/OPEN COUNTRY SITES LIKE KRST. CONTINUED THE MENTION OF WIND GUSTS AT KRST IN THE 19Z-24Z TIMEFRAME. && .CLIMATE... ISSUED AT 301 AM CST SUN FEB 23 2014 GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS HOW FEBRUARY AND THE WINTER WOULD STACK UP BASED ON THE CURRENT FORECAST... ...FOR THE MONTH OF FEBRUARY... LA CROSSE... 9.5 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1873... 3.9 1936... 4.3 1899... 9.4 ROCHESTER... 6.9 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1936... 0.5 1979... 5.7 1917... 6.0 ...FOR THE WINTER...DECEMBER THROUGH FEBRUARY... LA CROSSE... 11.6 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1872-1873... 8.4 1874-1875... 10.5 1977-1978... 11.4 1935-1936... 11.4 ROCHESTER... 8.9 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1978-1979... 5.6 1886-1887... 5.9 1935-1936... 8.1 1977-1978... 8.7 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RRS CLIMATE......AJ
AREA FORECAST DISCUSSION
NWS PUEBLO CO
323 PM MST SUN FEB 23 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 300 PM MST SUN FEB 23 2014 CURRENTLY...LOW STRATUS HAS SLOWLY ERODED TO LEAVE SUNNY SKIES ACROSS SOUTHERN COLORADO THIS AFTERNOON. TEMPERATURES HAVE BEEN HIGHLY DEPENDENT ON WIND...WHERE ITS WESTERLY...TEMPERATURES HAVE WARMED INTO THE 40S TO LOW 50S...WHERE ITS EASTERLY THEY HAVE REMAINED IN THE 30S. EXPECT A COUPLE OF MORE DEGREES OF WARMING FOR MOST AREAS...WITH THE EXCEPTION OF THE I-25 CORRIDOR...WHERE RAPID WARM UPS ARE POSSIBLE AS WESTERLIES TRY AND MAKE IT EAST. TONIGHT...BROAD NORTHWEST FLOW WILL ENCOMPASS THE REGION THROUGH THE SHORT TERM. THE MAIN QUESTION WILL BE THE DEGREE OF LOW STRATUS SLOSHING BACK WEST ACROSS THE PLAINS TONIGHT. FOLLOWED THE HRRR AND LOCAL WRF...WHICH KEEPS STRATUS OUT ALONG THE KANSAS BORDER WITH LITTLE PROGRESSION WEST. THE CAVEAT WILL BE HOW QUICKLY LEE TROUGH DEVELOPS AND LOW LEVEL WESTERLY FLOW. BOTH THE HRRR AND WRF HAVE WESTERLIES PICKING UP BY MIDNIGHT AND SHIFTING CLEAR OUT TO THE KANSAS BORDER BY 10-11Z. THIS SHOULD ALLOW FOR RAPID CLEARING OF ANY STRATUS OUT EAST BY DAYBREAK. IF THE LEE TROUGHING IS SLOWER TO DEVELOP THAN MODELS PROJECT...STRATUS COULD MAKE IT MUCH FURTHER WEST AND IMPACT THE WARMING EXPECTED BY SUNRISE. OVERNIGHT LOWS WILL GENERALLY BE IN THE 20S ACROSS THE REGION...WITH SOME LOWER 30S FOR THE BANANA BELT. MONDAY...BROAD NORTHWEST FLOW ALOFT CONTINUES WITH DRY CONDITIONS FOR SOUTHERN COLORADO. THE MAIN CONCERNS WILL BE BREEZY AFTERNOON WINDS LEADING TO AREAS OF BLOWING DUST AND ELEVATED FIRE WEATHER CONCERNS. STRONG MIXING BY THE AFTERNOON WILL BRING WIDESPREAD WIND GUSTS TO NEAR 30 MPH ALONG THE LEE SLOPES...EAST INTO THE I-25 CORRIDOR. THESE GUSTY WINDS WILL LIKELY PRODUCE AREAS OF BLOWING DUST...ESPECIALLY IN DUST PRONE AREAS SOUTH AND NORTH OF PUEBLO...CREATING HAZARDOUS DRIVING CONDITIONS. IN ADDITION...HUMIDITY VALUES ARE EXPECTED TO FALL INTO THE 10-15 PERCENT RANGE...AND WHEN COMBINED WITH THE GUSTY WINDS...WILL PRODUCE DANGEROUS FIRE WEATHER CONDITIONS...PARTICULARLY ALONG THE SOUTHERN I-25 CORRIDOR. EXPECT THE MIXING TO HELP BOOST TEMPERATURES FOR TOMORROW WITH HIGHS TOPPING OUT IN THE LOWER TO MID 60S FOR THE LOWER ELEVATIONS. MOZLEY .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 300 PM MST SUN FEB 23 2014 ...ACTIVE WX PATTERN AS PACIFIC STORMS BEGIN TO AFFECT THE REGION... MON NITE-INTO WED... CANADIAN HIGH PRESSURE WILL AFFECT THE HI PLAINS DURING THIS TIME PERIOD WITH PERSISTENT UPSLOPE FLOW OVER THE PLAINS. A SHORTWAVE ALOFT IN THE NW FLOW WILL MOVE ACROSS TUE AFTERNOON/EVENING...AND THIS DISTURBANCE WILL BRING A CHANCE OF RAIN AND SNOW TO THE PLAINS. FOR NOW PAINTED POPS IN THE HIGH ISOLATED/LOW END SCATTERED CATEGORY. WITH THE MOIST UPSLOPE FLOW EXPECT AN EXTENDED PERIOD OF CLOUDINESS TO AFFECT THE PLAINS. BY LATER WED...SFC FLOW WILL TRANSITION TO SOUTHERLY AND THIS SHOULD DECREASE THE CLOUDINESS. THE ONLY POSSIBLE EXCEPTION WILL BE THE COS AREA WHERE THE SOUTHERLY FLOW MAY KEEP THE CLOUDS IN PLACE UNTIL LATE MORNING. PERSISTENT SNOW SHOWERS WILL BE POSSIBLE ACROSS THE C MTNS FROM MON NITE-EARLY WED THURSDAY... THE FIRST IN A SERIES OF PACIFIC WEATHER SYSTEMS WILL BEGIN TO AFFECT THE REGION. VALLEY RAIN SHOWERS AND SNOW IN THE MTNS WILL AFFECT THE CONTDVD BY THU LATE MORNING OR EARLY AFTERNOON AND INCREASE THU AFTERNOON AND NITE. GIVEN THE QUALITY MOISTURE...INSTABILITY...UPSLOPE FLOW AND FORCING...WE WILL LIKELY SEE SNOWFALL AMOUNTS REQUIRING HILITES (WINTER STORM WARNING?) FOR THE CONTDVD. LATE THU NITE INTO FRIDAY... UPSLOPE FLOW DEVELOPS ON THE PLAINS AND WE WILL SEE COOLER WX...CLOUDINESS AND A CHANCE OF SOME PRECIP RETURNING TO THE LOWER ELEVATIONS. WEEKEND... FRI NITE INTO EARLY SATURDAY A BRIEF RIDGE WILL BUILD ALOFT DECREASING THE CLOUDS AND ENDING THE PRECIP...BUT ANOTHER STRONGER PACIFIC STORM WILL BE QUICKLY MOVING IN. AS THIS PACIFIC STORM MOVES TOWARDS THE CONTDVD...ANOTHER REINFORCING CANADIAN HIGH PRESSURE SYSTEM WILL BE MOVING DOWN THE PLAINS...AND WILL BE AFFECTING THE LOWER ELEVATIONS BY LATER SATURDAY MORNING. SNOW WILL DEVELOP ONCE AGAIN OVER THE MTNS DURING THE DAY SATURDAY WITH PRECIP DEVELOPING ON THE PLAINS LATE SAT AFTERNOON/EVENING. GUIDANCE AT THIS TIME IS FAVORING THE PALMER DVD BUT I WOULD NOT BE TOO SURPRISED IF ALL OF THE PLAINS RECEIVE SOME PRECIP SAT NITE INTO SUNDAY AS THE MIDLVL TROUGH MOVES OVER THE REGION. OVERALL METEOROLOGICAL CONDITIONS FOR THIS WEEKENDS STORM LOOK PRETTY GOOD GIVEN THAT THE COLD AIR WILL ALREADY BE IN PLACE AS THE DYNAMICS MOVE OVER THE REGION. FOR NOW I GOT TEMPS IN THE 30S AND 40S FOR THE WEEKEND WITH SLIGHT/LOW END SCT POPS FOR THE AREA. I WOULD NOT BE TOO SURPRISED IF THE TEMPS ARE LOWERED AND THE POPS ARE INCREASED AS WE GET CLOSER TO THIS EVENT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 300 PM MST SUN FEB 23 2014 VFR CONDITIONS THROUGH THE NEXT 24 HOURS AT ALL THREE TERMINALS. WESTERLY WINDS ARE FORECAST TO DEVELOP AT KPUB WITH GUSTS TO 30 KTS POSSIBLE MONDAY AFTERNOON. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY AFTERNOON FOR COZ228>230. && $$ SHORT TERM...MOZLEY LONG TERM...HODANISH AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1033 AM MST SUN FEB 23 2014 .UPDATE... && .SHORT TERM...LOW CLOUDS AND AREAS OF FOG RELUCTANT TO DISSIPATE OVER THE SOUTH PLATTE BASIN...INCLUDING NORTHERN AND CENTRAL PORTIONS OF THE I-25 CORRIDOR. ALTHOUGH VSBYS ARE BEGINNING TO IMPROVE SUCH AS THE CHANGE AT DIA FROM 1/4 MILE TO 2 MILES IN THE PAST FEW MINS.SLOWEST TO CLEAR OUT WILL BE AREAS ACROSS THE NORTHEAST CORNER WHERE NEW BLANKET OF SNOW WILL CONTINUE TO CHILL THE BNDRY LAYER AND WITH THE HIGHER CLOUD DECK GENERATED BY THE NEARBY JET WILL CONTINUE TO BLOCK OUT SUNSHINE. MEANWHILE...DRAMATIC CLEARING WAS UNDERWAY OVER AND NEAR THE HIGHER TERRAIN TO THE SOUTH AND SOUTHEAST OF DENVER WITH DRIER AIR MIXING DOWN OFF THE FOOTHILLS AND ALOFT. AT PRESENT RATE SHOULD SEE CLEARING SPREADING NORTHWARD OVER THE REMAINDER OF THE DENVER METRO AREA OVER THE NEXT COUPLE OF HOURS..AND THE FOG DISSIPATING IN MOST AREAS BY NOON OR SHORTLY THEREAFTER. BECAUSE OF THE SLOW CLEARING...FELT IT NECESSARY TO LOWER HIGH TEMPERATURES ON THE PLAINS BY AT LEAST A FEW DEGS UP AGAINST THE FOOTHILLS...AND AS MUCH AS 5-10 DEG F FARTHER OUT ON THE PLAINS IN THE CLOUDY AREAS. FURTHERMORE...HAVE OBSERVED A MODEST JUMP IN WIND SPEEDS AT FRONT RANGE RECORDING PAST COUPLE OF HOURS. RUC AND NAM ALSO SHOW THIS TREND. SO NUDGED UP SPEEDS IN THIS AREA FOR THE REMAINDER OF THE DAY. COULD SEE GUSTSAROUND 50 MPH IN PARTS OF THE FOOTHILLS... WITH POSSIBLE GUSTS AROUND 65 MPH ON THE HIGHER PEAKS. TONIGHT...MODELS SHOW A RETURN OF BOUNDARY LAYER MOISTURE UP THE SOUTH PLATTE RIVER BASIN WITH EAST-SOUTHEAST LOW-LEVEL FLOW. RH FIELDS INDICATE NEAR SATURATED AIR IN THE AREA OVERNIGHT. SO INTRODUCED AREAS OF FOG AND LOW CLOUDS FOR AREAS ROUGHLY NORTH AND EAST OF THE DENVER AREA FOR MOST OF TONIGHT. DOWNSLOPE FLOW OFF THE FOOTHILLS SHOULD KEEP THE LOW CLOUDS AND FOG OUT OF THE DENVER METRO AREA...EXCEPT PERHAPS ITS FAR NORTHERN SUBURBS AND COMMUNITIES. .AVIATION...ILS-IFR CONDITIONS DUE TO LOW CIGS AND FOG AT DENVER AREA AIRPORTS EXPECTED THROUGH 1830Z...THEN GRADUAL IMPROVEMENT FROM THE SOUTH AND WEST AS DRIER AIR MOVES DOWN OF THE FOOTHILLS AND PALMER DIVIDE. COULD SEE VFR CONDITIONS AT BJC AND APA BY 19Z OR 20Z. WHEREAS...DIA MAY CONTINUE TO SEE IFR CONDITIONS THROUGH 19Z...THEN A GRADUAL LIFT IN CIGS AND VSBYS THEREAFTER WITH LIGHT SFC WINDS GRADUALLY BECOMING EAST-SOUTHEAST IN DIRECTION. SHOULD SEE CLEARING OVERNIGHT...HOWEVER...PATCHY LOW CLOUDS AND FOG MAY FORM AGAIN IN THE DIA AREA AFTER 04Z TONIGHT...WITH VSBYS POSSIBLY AS LOW AS 3 MILES IN PATCHY FOG. && .PREV DISCUSSION... /ISSUED 417 AM MST SUN FEB 23 2014/ SHORT TERM...SNOW IS LIFTING TO THE ENE ABOUT AS EXPECTED WITH DRIER AIR ALOFT MOVING IN. STILL DECENT SNOW RIGHT ALONG THE NORTHERN BORDER AND OVER THE NORTHERN MOUNTAINS FOR A FEW MORE HOURS. ADVISORIES ARE SET TO EXPIRE AT 6 AM AND THAT LOOKS ABOUT RIGHT. MEANWHILE THERE IS A SOLID STRATUS DECK ON THE PLAINS AND WITH SOUTHEAST WINDS DEVELOPING EXPECT THAT THIS WILL HANG ON LONGER THAN WE HAD PREVIOUSLY FORECAST. COULD BE A RAGGED EDGE TO THIS CLOUD DECK OVER THE DENVER AREA COMPLICATING THE FORECAST. WE HAVE HAD SOME PLACES WHERE IT HAS CLEARED AND THE STRATUS FILLED IN AT A LOWER HEIGHT...AND STILL A FEW PATCHES OF LOWER CLOUDS BENEATH IT...NOTABLY FROM GREELEY INTO DIA. NOT SO SURE OF THE DENSE FOG AT THE AIRPORT...BUT IN GENERAL EXPECTING PERSISTENCE FOR MUCH OF THE MORNING WITH A SLOW BURN OFF THE REST OF THE DAY. WE ARE ALREADY SHOWING QUITE A TEMPERATURE GRADIENT FROM DENVER TOWARD THE NORTHEAST CORNER OF THE STATE...WHICH WILL BE ENHANCED BY BOTH THE TIMING OF THE CLEARING AND THE NEW SNOW COVER. IF THE CLEARING IS MUCH SLOWER WE COULD BE TOO WARM IN DENVER. FOR TONIGHT...THERE COULD BE SOME STRATUS LINGERING/REDEVELOPING OR ADVECTING INTO THE EASTERN BORDER AREA AS SOUTHERLY WINDS CONTINUE. OTHERWISE RELATIVELY CLEAR SKIES SHOULD ALLOW TEMPERATURES TO DROP FAIRLY WELL DESPITE SOME WIND AND THE WARMING ALOFT. DROPPED FORECAST LOWS JUST SLIGHTLY. ALSO ADDED SOME MORE WIND TO THE MOUNTAINS AS THE FLOW ALOFT INCREASES AGAIN AND WE MAY START TO GET A MOUNTAINTOP INVERSION FOR A BETTER EAST SLOPE WAVE LATE TONIGHT. LONG TERM...IT IS ALL WEST-NORTHWESTERLY FLOW ALOFT FOR THE FORECAST AREA MONDAY THROUGH TUESDAY NIGHT. THE JET MAXIMUM GENERALLY STAYS JUST NORTHEAST OF COLORADO THROUGH THE PERIOD. THE SYNOPTIC SCALE ENERGY IS QUITE WEAK ALL FOUR PERIODS. THE BOUNDARY LAYER FLOW IS DOWNSLOPING SOUTHWESTERLY MONDAY INTO THE AFTERNOON. A COLD FRONT COMES IN MONDAY AFTERNOON...WITH UPSLOPE BEHIND IT FOR THE PLAINS AND FOOTHILLS THROUGH MUCH OF MONDAY NIGHT. ANOTHER COLD FRONT MOVES IN TUESDAY MORNING WITH PRETTY DECENT UPSLOPE TUESDAY AFTERNOON INTO THE EARLY EVENING. NORMAL DRAINAGE WIND PATTERNS SEEM REASONABLE LATER TUESDAY NIGHT. FOR MOISTURE...THERE ISN`T A LOT AROUND ON MONDAY EARLY...BUT IT STARTS TO INCREASE IN THE AFTERNOON. IT GETS DEEPER OVER THE MOUNTAINS MONDAY NIGHT...AND THERE IS SOME IN THE LOWER LEVELS OVER THE PLAINS. MOISTURE INCREASES ON TUESDAY AND IT IS PRETTY DEEP OVER ALL THE CWA TUESDAY AFTERNOON THROUGH TUESDAY MIDNIGHT ..THEN IT DECREASES. THE QPF FIELDS HAVE A TAD OF MEASURABLE SNOWFALL OVER THE NORTHERN CWA MONDAY LATE DAY INTO THE EVENING. BETTER MEASURABLE SNOW COVERING MUCH OF THE CWA IS PROGGED ON TUESDAY FROM 18Z INTO 06Z TUESDAY EVENING. MODELS ARE ALL OVER THE PLACE WHEN COMPARED TO ONE ANOTHER. FOR POPS...WILL UP THEM ON TUESDAY FOR MOST OF THE CWA. THERE WILL BE NONE FOR MONDAY...AND A TAD MONDAY NIGHT. FOR TEMPERATURES...WILL BE A BIT WARMER THAN TODAY. TUESDAY LOOKS TO BE CONSIDERABLY COLDER. THE NAM MOS HAS A HIGH OF 55 F FOR DIA TUESDAY...THE ECMWF MOS HAS 24 F. FOR THE LATER DAYS...WEDNESDAY THROUGH SATURDAY...MODELS SHOW WEAKENING NORTHWESTERLY FLOW ALOFT WEDNESDAY...WITH A DYING UPPER RIDGE MOVING IN WEDNESDAY NIGHT. THERE IS A WEAK UPPER TROUGH FOR LATE THURSDAY. STRONGER WEST-NORTHWESTERLY FLOW ALOFT IS IN PLACE FRIDAY...THEN SOUTHWESTERLY FLOW ALOFT ON SATURDAY WITH A DEVELOPING TROUGH TO THE WEST. CONFIDENCE IS A BIT SHAKY. AVIATION...EXPECT STRATUS TO LINGER IN THE DENVER AREA THROUGH 16Z-18Z...WITH SLOWER CLEARING ON THE EASTERN PLAINS. SUSPECT THE DENSE FOG AT KDEN AT THIS TIME IS NOT WIDESPREAD...BUT WITH LIGHT NE WINDS AND POSSIBLY CLOUDS ABOVE IT THERE COULD BE LIFR CONDITIONS THERE AS LATE AS 16Z. VFR CONDITIONS SHOULD DEVELOP BY 18Z AND CONTINUE THROUGH TONIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BAKER LONG TERM....RJK AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
155 PM CST SUN FEB 23 2014 .DISCUSSION... 213 AM CST TODAY... BROAD SFC RIDGE STRETCHES FROM THE NORTHERN PLAINS SOUTHEAST THROUGH THE WESTERN OHIO VALLEY. THIS HAS RESULTED IN A LIGHT NORTHWEST FLOW ACROSS NORTHERN IL/NORTHWEST IN EARLY THIS MORNING. BAROCLINIC ZONE REMAINS ORIENTED FROM CENTRAL MO STRETCHING NORTHEAST THROUGH CENTRAL IL/IN AND DRIFTING SOUTHEAST. IR IMAGERY SHOWS THE AREA OF CLOUDS WELL...ASSOCIATED WITH THIS BAND OF PRECIP. THEN JUST WEST OF THIS FEATURE WAS YET ANOTHER WEAK MID- LVL WAVE THAT HAD ANOTHER AREA OF MID/UPR LVL MOISTURE ASSOCIATED WITH IT AND WAS SLIDING EAST...BEING STEERED BY THE SEMI-ZONAL FLOW IN THE MID-LVLS. TEMPS THIS MORNING WILL HOVER AROUND THE TEENS FOR THE BULK OF THE FORECAST AREA...PERHAPS HOLDING IN UPR TEENS/LOW 20S FOR THE SOUTHERN CWFA. OTHERWISE FOR TODAY HIGH PRESSURE WILL PUSH THIS AREA OF CLOUDS THIS MORNING TO THE SOUTH...AND ALLOW FOR A DRY DAY. SKIES WILL EVENTUALLY BECOME P-CLOUDY BY MIDDAY...WITH HIGHS WARMING MAINLY INTO THE 20S. CLOSER TO 30 FOR THE FAR SOUTHERN CWFA. THEN FOR TONIGHT...HIGH PRESSURE WILL CONTINUE TO HOLD ACROSS THE FORECAST AREA AND LIMIT CLOUD COVER. JUST NORTH OF THE AREA THOUGH...AND CLOSER TO A STRONGER MID-LVL VORT WILL BE THICKER CLOUD COVER. WINDS WILL GENERALLY REMAIN LIGHT FROM THE NORTHWEST...WHICH COUPLED WITH 850MB TEMPS HOVERING ARND -10 TO -12 DEG C SHOULD LIMIT HOW COOL TEMPS RADIATE OVERNIGHT. SO HAVE ONLY NUDGED TEMPS DOWN A LITTLE...GENERALLY IN THE SINGLE DIGITS ABOVE ZERO. COULD SEE SOME OF THE TRADITIONALLY COOLER LOCATIONS DIP TO ARND ZERO BY DAYBREAK MON. CONFIDENCE...HIGH. MONDAY THROUGH TUESDAY... 500MB TROUGH AXIS OVER THE GREAT LAKES REGION PUSHES EAST...WITH AN AREA OF WEAK RIDGING ARRIVING MIDDAY MON OVER THE FORECAST AREA. HOWEVER GIVEN THE SEMI-ZONAL FLOW...WHICH IS GENERALLY A MORE PROGRESSIVE SETUP...THE NEXT WAVE CONTINUES TO BE PROGGED FOR ARRIVAL MON LATE AFTN/EVE. LATEST FORECAST GUIDANCE HAS CONTINUED TO SUGGEST THE MID-LVL HEIGHT RISES MAY BE A LITTLE SLOWER TO DEPART THE REGION...WHICH WOULD LIKELY HAVE AN INFLUENCE ON THE WEAK WAVE ARRIVING POSSIBLY LATER. THE MAIN TIMING DOES APPEAR TO BE CONSISTENT WITH JUST AFT 00Z TUE...AND GIVEN THE PREV-DISCUSSED PROGRESSIVE FLOW...SKIES WILL THICKEN RATHER QUICKLY AND CIGS WILL LOWER WITH EASE. LOCAL MODEL INDICATES A SLIGHTLY LATER ARRIVAL AND CLOSER TO 6Z TUE...BUT ALSO IS INDICATING THE WAVE WILL BE WEAKENING UPON ARRIVAL. CONFIDENCE ON THIS WAVE WEAKENING AS IT ARRIVES IS VERY LOW...GIVEN THE DECENT MID-LVL FORCING ASSOCIATED. TEMPS CONTINUE TO BE COOL ENOUGH TO SUPPORT LGT SNOW FOR THE AREA...AND EXPECT SLR ARND 15:1 TO 18:1. THIS WILL LIKELY PRODUCE A QUICK 1 TO 2 INCHES OF SNOWFALL ACROSS MOST OF THE CWFA. BY 12-15Z TUE...THE BULK OF THE WAVE/SNOW WILL BE PUSHING EAST AND COMING TO AN END. THEN FOR TUE...500MB TROUGH AXIS ARRIVES AS AN ARCTIC AIRMASS CONTINUES TO PUSH SOUTH FROM CANADA TOWARDS THE UPPER MIDWEST TUE AFTN. CURRENTLY EXPECT HIGHS TUE TO HOLD IN THE TEENS/LOW 20S...HOWEVER BY TUE NGT THE BOUNDARY WILL BE PUSHING ACROSS THE FORECAST AREA AND TEMPS WILL BE DROPPING TO A FEW DEGREES BELOW ZERO. CONFIDENCE...HIGH. CONFIDENCE IN SNOW ACCUMS MON EVE/OVERNIGHT...HIGH. WEDNESDAY THROUGH SUNDAY... ENSEMBLES AND OPERATIONAL SOLUTIONS HAVE CONTINUED TO BE IN GOOD AGREEMENT WITH THE ARRIVAL OF YET ANOTHER ARCTIC AIRMASS. BY WED THE 500MB TROUGH AXIS WILL BE OVERHEAD. CURRENT PROGS INDICATE TEMPS IN MID-LVLS WILL HOVER ARND -20 TO -25 DEG C. WHEN APPLYING THIS TOWARDS LOCAL CLIMATE WHICH LIKELY YIELD HIGH TEMPS WED IN THE SINGLE DIGITS ABOVE ZERO TO POSSIBLY THE LOW TEENS. SFC RIDGE WILL BE SLIDING OVER THE AREA AS WELL...WHICH SHOULD LIMIT HOW MUCH LOWER WIND CHILL VALUES WILL BE WED. THEN FOR WED NGT...FLOW GRADUALLY TURNS WESTERLY IN THE LLVLS. A WEAK SHORTWAVE IS PROGGED TO CLIP THE NORTHERN GREAT LAKES REGION...HOWEVER EXPECT GENERALLY DRY WEATHER FOR THE FORECAST AREA WED/WED NGT. FOR THE REMAINDER OF THE EXTENDED PERIODS...ENSEMBLES REMAIN IN DECENT AGREEMENT WITH YET ANOTHER SFC RIDGE SLIDING SOUTHEAST FROM CENTRAL CANADA TOWARDS THE PLAINS AND STRETCHING EAST TO THE WESTERN GREAT LAKES THUR. THIS SHOULD HELP TO MAINTAIN UNSEASONABLY COLD CONDS FOR THE FORECAST AREA...WITH TEMPS STRUGGLING TO WARM BEYOND THE LOW/MID TEENS THUR AFTN. STRONG VORTEX BEGINS TO LIFT NORTHEAST THUR NGT/FRI...WITH SOME MODERATION TO TEMPS POISED FOR THE END OF THE WEEK INTO THE FIRST HALF OF NEXT WEEKEND. ALTHOUGH THIS IS RELATIVE...AS TEMPS WILL CONTINUE TO BE UNSEASONABLY COOL IN THE TEENS/LOW 20S. GUIDANCE IS SUGGESTING THE SOUTHERN STREAM WILL BECOME ACTIVE YET AGAIN IN THE LATER PERIODS...AND INDICATES THE PRECIP WILL REMAIN SOUTH OF THE CWFA. ALTHOUGH COULD SEE SOME ADJUSTMENTS TO THE PLACEMENT OF EACH SOUTHERN STREAM WAVE. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * NONE. JEE //DISCUSSION...UPDATED 18Z... A LARGE SURFACE RIDGE STRETCHES THROUGH THE TERMINALS THIS AFTN AND IT WILL REMAIN STATIONARY THROUGH THE PERIOD. VFR CONDITIONS ARE EXPECTED WITH GUSTY W TO NW WINDS THIS AFTN...ARND 18 KT. GUSTS SUBSIDE THIS EVENING WITH W TO NW WINDS 10-12KT CONTINUING. GUSTS REDEVELOP BY MID MONDAY MORNING BUT ONLY TO 16 KT. THE GRADIENT THEN SLACKENS RESULTING IN SUSTAINED 10 KT WEST WINDS LATE IN THE AFTERNOON. CLOUD COVER WILL THICKEN AS WELL LATE MONDAY AFTERNOON BUT REMAIN VFR. LOOKING AHEAD...SNOW IS STILL EXPECTED MONDAY NIGHT INTO TUESDAY WITH LIGHT ACCUMULATIONS POSSIBLE. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN ALL FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...SNOW LIKELY WITH LIGHT ACCUMULATIONS POSSIBLE. TUESDAY THROUGH SATURDAY...VFR LIKELY. BMD && .MARINE... 154 PM CST LOW PRESSURE CENTERED NEAR JAMES BAY THIS AFTERNOON CONTINUES TO WEAKEN THIS AFTERNOON. HOWEVER...A BROAD EXPANSIVE RIDGE OF SURFACE HIGH PRESSURE...EXTENDING FROM THE NORTHERN PLAINS EAST SOUTHEASTWARD ACROSS THE OHIO VALLEY...IS PRODUCING AN ENHANCED PRESSURE GRADIENT ACROSS LAKE MICHIGAN. THIS WILL CONTINUE TO SUPPORT WESTERLY WINDS UP TO 30 KT AT TIMES INTO TONIGHT. GIVEN THAT SOME OF THESE STRONG WINDS WILL ALSO SET UP ACROSS THE SOUTHERN TIP OF LAKE MICHIGAN TONIGHT...IT APPEARS WAVES IN THE ICE FREE AREAS OF NORTHWESTERN INDIANA WILL GET WAVES OVER 4 FEET THROUGH MONDAY. THEREFORE A SMALL CRAFT ADVISORY WILL BE ISSUED FOR LATE TONIGHT THROUGH MONDAY EVENING...MAINLY FOR THE NEAR SHORE AREAS EAST OF GARY INDIANA. A COUPLE OF CLIPPER TYPE SYSTEMS ARE EXPECTED TO DROP SOUTHEASTWARD ACROSS THE LAKES REGION THIS WEEK. THE FIRST...WILL DROP ACROSS SOUTHEASTERN ONTARIO LATE TUESDAY INTO TUESDAY NIGHT. THIS LOOKS TO RESULT IN AN ENHANCEMENT TO THE WIND FIELD AS A COLD FRONT DROPS ACROSS THE LAKE LATE TUESDAY AND TURNS TO WINDS OUT OF THE NORTHWEST UP TO AROUND 30 KT FOR A PERIOD TUESDAY NIGHT INTO EARLY WEDNESDAY. ANOTHER FAST MOVING CLIPPER SYSTEM IS EXPECTED TO QUICKLY MOVE IN ACROSS THE GREAT LAKES REGION BY LATE WEDNESDAY. THIS WILL RESULT IN BACKING WINDS OUT OF THE WEST-SOUTHWEST DURING THE DAY WEDNESDAY AS SURFACE HIGH PRESSURE SETS UP ACROSS SOUTH CENTRAL CONUS. WIND SPEEDS DURING THIS PERIOD APPEAR THAT THEY WILL REACH GALE FORCE IN THE 35 TO 40 KT RANGE. THE WINDS WILL THAN SHIFT BACK OUT OF THE NORTHWEST WEDNESDAY NIGHT AS ANOTHER STRONG COLD FRONT PUSHES ACROSS THE LAKE. THESE NORTHWESTERLY WINDS COULD REMAIN NEAR GALE FORCE FOR A SHORT PERIOD INTO EARLY THURSDAY...BUT AS HIGH PRESSURE SETS UP OVER THE LAKE ON THURSDAY...WINDS WILL ABATE SIGNIFICANTLY LATER IN THE DAY. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1128 AM CST Sun Feb 23 2014 .DISCUSSION... ISSUED 956 AM CST Sun Feb 23 2014 Lingering band of light snow in the southeast CWA has pushed into Indiana. Radar mosaics still showing quite a few returns along the I-70 corridor, but these are mostly elevated as surface obs are showing cloud heights of 7000 feet or higher, so little more than flurries anticipated the remainder of the morning. Persistent mid level clouds continue to stream over the remainder of the forecast area and should continue through the afternoon. Lowered temperatures a couple degrees across the southeast CWA as they had continued to slip downward as the snow began a few hours ago, but the forecast over the remainder of the area still is in decent shape. Geelhart && .AVIATION... ISSUED 1125 AM CST Sun Feb 23 2014 VFR conditions expected through the period, with ceilings generally above 10,000 feet. Most likely period for skies to be clear will be 06-12Z. After that, mid-level clouds will rapidly increase from the northwest Monday morning ahead of the next clipper system, although any associated precipitation is not expected until early evening. Northwest winds to persist through the period, due to high pressure over the Dakotas. Geelhart && .PREV DISCUSSION... ISSUED 330 AM CST Sun Feb 23 2014 SHORT TERM...Today through Wednesday night Surface cold front has pressed south of the Ohio River into NW AR while 1042 mb arctic high pressure over Alberta was nosing into the central and northern plains. Colder air easing south into central IL early this morning with temps slipping through the 20s over central IL and low to mid 30s in southeast IL. Temps as cold as 19F at Galesburg and Lacon. Frontogenetic forecasting close to 850 mb boundary near I-70 had band of light snow that diminished east into central IN past few hours with dusting to as much as 1 inch between I-72 and I-70. Will carry just slight chance of light snow this morning over southeast IL per HRRR model run. Radar mosaic shows light pcpn returns and mainly virga over northern MO into NW counties. RUC & HRRR keeps most of this very light snow west of central IL this morning but could be a few flurries this morning into central IL. Clouds to decrease from the north during the afternoon and linger longest in southeast IL. Much colder highs today range from mid 20s from Peoria and Bloomington north to 35-40F over southeast IL with Lawrenceville near 40F. Arctic high pressure noses into the mid MS river valley tonight and brings fair skies and cold lows of 5-10F from Lincoln north and mid to upper teens in southeast IL. Clouds increase Monday morning ahead of northern stream clipper system which digs into the Midwest Monday night. Slowed down chances of light snow Monday afternoon as central IL appear dry through sunset Monday with best chances of light snow arriving Monday night northern half of CWA. Generally less than 1 inch of snow with northern IL having as much as 1-2 inches of snow possible. Highs Monday again in mid 20s north and mid to upper 30s in southeast IL. Lows Monday night in the teens central IL and lower 20s southeast IL. Chances of light snow NE of central IL by Tuesday morning. Highs Tue range from lower 20s northern areas to mid 30s in southeast IL. Core of arctic high pressure settles into MO by 18Z/noon Wed and brings even colder air into the region during middle of the week. Lows overnight Tue night into early Wed morning could reach zero to 5 below NW of IL river with single digit lows over much of central IL and far southeast IL around 10F. Highs Wed in the mid teens NE to lower 20s SW and SE areas. Lows Wed night again in the single digits over northern half of CWA and lower teens south. LONG TERM...Thursday through Saturday night Temps modify slightly during end of week but still average below normal through next weekend. The 8-14 day outlook for Mar 2-8 has 60-70% chance of below normal temperatures and 40% chance of above normal precipitation, which has been the normal for this winter. Generally dry and cold conditions expected late this week into next weekend. Though ECMWF and GEM models show some light QPF Friday while heavier QPF passes south of IL Friday. GFS model is dry over IL on Friday. Stayed close to ALLblend pops late this week and into the weekend which is dry. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1120 AM CST SUN FEB 23 2014 .DISCUSSION... 213 AM CST TODAY... BROAD SFC RIDGE STRETCHES FROM THE NORTHERN PLAINS SOUTHEAST THROUGH THE WESTERN OHIO VALLEY. THIS HAS RESULTED IN A LIGHT NORTHWEST FLOW ACROSS NORTHERN IL/NORTHWEST IN EARLY THIS MORNING. BAROCLINIC ZONE REMAINS ORIENTED FROM CENTRAL MO STRETCHING NORTHEAST THROUGH CENTRAL IL/IN AND DRIFTING SOUTHEAST. IR IMAGERY SHOWS THE AREA OF CLOUDS WELL...ASSOCIATED WITH THIS BAND OF PRECIP. THEN JUST WEST OF THIS FEATURE WAS YET ANOTHER WEAK MID- LVL WAVE THAT HAD ANOTHER AREA OF MID/UPR LVL MOISTURE ASSOCIATED WITH IT AND WAS SLIDING EAST...BEING STEERED BY THE SEMI-ZONAL FLOW IN THE MID-LVLS. TEMPS THIS MORNING WILL HOVER AROUND THE TEENS FOR THE BULK OF THE FORECAST AREA...PERHAPS HOLDING IN UPR TEENS/LOW 20S FOR THE SOUTHERN CWFA. OTHERWISE FOR TODAY HIGH PRESSURE WILL PUSH THIS AREA OF CLOUDS THIS MORNING TO THE SOUTH...AND ALLOW FOR A DRY DAY. SKIES WILL EVENTUALLY BECOME P-CLOUDY BY MIDDAY...WITH HIGHS WARMING MAINLY INTO THE 20S. CLOSER TO 30 FOR THE FAR SOUTHERN CWFA. THEN FOR TONIGHT...HIGH PRESSURE WILL CONTINUE TO HOLD ACROSS THE FORECAST AREA AND LIMIT CLOUD COVER. JUST NORTH OF THE AREA THOUGH...AND CLOSER TO A STRONGER MID-LVL VORT WILL BE THICKER CLOUD COVER. WINDS WILL GENERALLY REMAIN LIGHT FROM THE NORTHWEST...WHICH COUPLED WITH 850MB TEMPS HOVERING ARND -10 TO -12 DEG C SHOULD LIMIT HOW COOL TEMPS RADIATE OVERNIGHT. SO HAVE ONLY NUDGED TEMPS DOWN A LITTLE...GENERALLY IN THE SINGLE DIGITS ABOVE ZERO. COULD SEE SOME OF THE TRADITIONALLY COOLER LOCATIONS DIP TO ARND ZERO BY DAYBREAK MON. CONFIDENCE...HIGH. MONDAY THROUGH TUESDAY... 500MB TROUGH AXIS OVER THE GREAT LAKES REGION PUSHES EAST...WITH AN AREA OF WEAK RIDGING ARRIVING MIDDAY MON OVER THE FORECAST AREA. HOWEVER GIVEN THE SEMI-ZONAL FLOW...WHICH IS GENERALLY A MORE PROGRESSIVE SETUP...THE NEXT WAVE CONTINUES TO BE PROGGED FOR ARRIVAL MON LATE AFTN/EVE. LATEST FORECAST GUIDANCE HAS CONTINUED TO SUGGEST THE MID-LVL HEIGHT RISES MAY BE A LITTLE SLOWER TO DEPART THE REGION...WHICH WOULD LIKELY HAVE AN INFLUENCE ON THE WEAK WAVE ARRIVING POSSIBLY LATER. THE MAIN TIMING DOES APPEAR TO BE CONSISTENT WITH JUST AFT 00Z TUE...AND GIVEN THE PREV-DISCUSSED PROGRESSIVE FLOW...SKIES WILL THICKEN RATHER QUICKLY AND CIGS WILL LOWER WITH EASE. LOCAL MODEL INDICATES A SLIGHTLY LATER ARRIVAL AND CLOSER TO 6Z TUE...BUT ALSO IS INDICATING THE WAVE WILL BE WEAKENING UPON ARRIVAL. CONFIDENCE ON THIS WAVE WEAKENING AS IT ARRIVES IS VERY LOW...GIVEN THE DECENT MID-LVL FORCING ASSOCIATED. TEMPS CONTINUE TO BE COOL ENOUGH TO SUPPORT LGT SNOW FOR THE AREA...AND EXPECT SLR ARND 15:1 TO 18:1. THIS WILL LIKELY PRODUCE A QUICK 1 TO 2 INCHES OF SNOWFALL ACROSS MOST OF THE CWFA. BY 12-15Z TUE...THE BULK OF THE WAVE/SNOW WILL BE PUSHING EAST AND COMING TO AN END. THEN FOR TUE...500MB TROUGH AXIS ARRIVES AS AN ARCTIC AIRMASS CONTINUES TO PUSH SOUTH FROM CANADA TOWARDS THE UPPER MIDWEST TUE AFTN. CURRENTLY EXPECT HIGHS TUE TO HOLD IN THE TEENS/LOW 20S...HOWEVER BY TUE NGT THE BOUNDARY WILL BE PUSHING ACROSS THE FORECAST AREA AND TEMPS WILL BE DROPPING TO A FEW DEGREES BELOW ZERO. CONFIDENCE...HIGH. CONFIDENCE IN SNOW ACCUMS MON EVE/OVERNIGHT...HIGH. WEDNESDAY THROUGH SUNDAY... ENSEMBLES AND OPERATIONAL SOLUTIONS HAVE CONTINUED TO BE IN GOOD AGREEMENT WITH THE ARRIVAL OF YET ANOTHER ARCTIC AIRMASS. BY WED THE 500MB TROUGH AXIS WILL BE OVERHEAD. CURRENT PROGS INDICATE TEMPS IN MID-LVLS WILL HOVER ARND -20 TO -25 DEG C. WHEN APPLYING THIS TOWARDS LOCAL CLIMATE WHICH LIKELY YIELD HIGH TEMPS WED IN THE SINGLE DIGITS ABOVE ZERO TO POSSIBLY THE LOW TEENS. SFC RIDGE WILL BE SLIDING OVER THE AREA AS WELL...WHICH SHOULD LIMIT HOW MUCH LOWER WIND CHILL VALUES WILL BE WED. THEN FOR WED NGT...FLOW GRADUALLY TURNS WESTERLY IN THE LLVLS. A WEAK SHORTWAVE IS PROGGED TO CLIP THE NORTHERN GREAT LAKES REGION...HOWEVER EXPECT GENERALLY DRY WEATHER FOR THE FORECAST AREA WED/WED NGT. FOR THE REMAINDER OF THE EXTENDED PERIODS...ENSEMBLES REMAIN IN DECENT AGREEMENT WITH YET ANOTHER SFC RIDGE SLIDING SOUTHEAST FROM CENTRAL CANADA TOWARDS THE PLAINS AND STRETCHING EAST TO THE WESTERN GREAT LAKES THUR. THIS SHOULD HELP TO MAINTAIN UNSEASONABLY COLD CONDS FOR THE FORECAST AREA...WITH TEMPS STRUGGLING TO WARM BEYOND THE LOW/MID TEENS THUR AFTN. STRONG VORTEX BEGINS TO LIFT NORTHEAST THUR NGT/FRI...WITH SOME MODERATION TO TEMPS POISED FOR THE END OF THE WEEK INTO THE FIRST HALF OF NEXT WEEKEND. ALTHOUGH THIS IS RELATIVE...AS TEMPS WILL CONTINUE TO BE UNSEASONABLY COOL IN THE TEENS/LOW 20S. GUIDANCE IS SUGGESTING THE SOUTHERN STREAM WILL BECOME ACTIVE YET AGAIN IN THE LATER PERIODS...AND INDICATES THE PRECIP WILL REMAIN SOUTH OF THE CWFA. ALTHOUGH COULD SEE SOME ADJUSTMENTS TO THE PLACEMENT OF EACH SOUTHERN STREAM WAVE. CONFIDENCE...MEDIUM/HIGH. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * NONE. JEE //DISCUSSION...UPDATED 18Z... A LARGE SURFACE RIDGE STRETCHES THROUGH THE TERMINALS THIS AFTN AND IT WILL REMAIN STATIONARY THROUGH THE PERIOD. VFR CONDITIONS ARE EXPECTED WITH GUSTY W TO NW WINDS THIS AFTN...ARND 18 KT. GUSTS SUBSIDE THIS EVENING WITH W TO NW WINDS 10-12KT CONTINUING. GUSTS REDEVELOP BY MID MONDAY MORNING BUT ONLY TO 16 KT. THE GRADIENT THEN SLACKENS RESULTING IN SUSTAINED 10 KT WEST WINDS LATE IN THE AFTERNOON. CLOUD COVER WILL THICKEN AS WELL LATE MONDAY AFTERNOON BUT REMAIN VFR. LOOKING AHEAD...SNOW IS STILL EXPECTED MONDAY NIGHT INTO TUESDAY WITH LIGHT ACCUMULATIONS POSSIBLE. JEE //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN ALL FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...SNOW LIKELY WITH LIGHT ACCUMULATIONS POSSIBLE. TUESDAY THROUGH SATURDAY...VFR LIKELY. BMD && .MARINE... 302 AM CST MODERATE WEST TO NORTHWEST WINDS ARE EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK ACROSS LAKE MICHIGAN ON THE EASTERN PERIPHERY OF A STRONG RIDGE THAT EXTENDS FROM THE CANADIAN ROCKIES INTO THE OHIO VALLEY. WINDS WILL GENERALLY BE IN THE 20 TO 30 KT RANGE THROUGH TUESDAY...THEN A SERIES OF LOWS WILL DROP FROM CANADA INTO THE GREAT LAKES REGION...THE STRONGEST OF WHICH WILL BE WEDNESDAY NIGHT. A SURGE OF ARCTIC AIR WILL OVERSPREAD THE WESTERN LAKES BEHIND THIS LOW AND A PERIOD OF NORTHWESTERLY GALES IS POSSIBLE...ALONG WITH FREEZING SPRAY. THE RIDGE WILL START TO BUILD CLOSER TO LAKE MICHIGAN LATER IN THE WEEK AND INTO THE WEEKEND WITH WINDS DIMINISHING. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 957 AM CST Sun Feb 23 2014 .DISCUSSION... ISSUED 956 AM CST Sun Feb 23 2014 Lingering band of light snow in the southeast CWA has pushed into Indiana. Radar mosaics still showing quite a few returns along the I-70 corridor, but these are mostly elevated as surface obs are showing cloud heights of 7000 feet or higher, so little more than flurries anticipated the remainder of the morning. Persistent mid level clouds continue to stream over the remainder of the forecast area and should continue through the afternoon. Lowered temperatures a couple degrees across the southeast CWA as they had continued to slip downward as the snow began a few hours ago, but the forecast over the remainder of the area still is in decent shape. Geelhart && .AVIATION... ISSUED 540 AM CST Sun Feb 23 2014 VFR conditions will prevail at all TAF sites next 24hrs. Mid clouds around 9kft will overspread all sites this morning and remain over the area/sites through the morning and into the afternoon. Models indicate that the clouds will slide south away from the TAF sites this afternoon, but satellite loop/trends show clouds moving due east. So will keep at least BKN mid clouds over the area into this evening. Then skies will clear around midnight. Winds will be northerly to start and then shifts to northwesterly as a high pressure ridge pushes into the area late this afternoon and into the evening. Auten && .PREV DISCUSSION... ISSUED 330 AM CST Sun Feb 23 2014 SHORT TERM...Today through Wednesday night Surface cold front has pressed south of the Ohio River into NW AR while 1042 mb arctic high pressure over Alberta was nosing into the central and northern plains. Colder air easing south into central IL early this morning with temps slipping through the 20s over central IL and low to mid 30s in southeast IL. Temps as cold as 19F at Galesburg and Lacon. Frontogenetic forecasting close to 850 mb boundary near I-70 had band of light snow that diminished east into central IN past few hours with dusting to as much as 1 inch between I-72 and I-70. Will carry just slight chance of light snow this morning over southeast IL per HRRR model run. Radar mosaic shows light pcpn returns and mainly virga over northern MO into NW counties. RUC & HRRR keeps most of this very light snow west of central IL this morning but could be a few flurries this morning into central IL. Clouds to decrease from the north during the afternoon and linger longest in southeast IL. Much colder highs today range from mid 20s from Peoria and Bloomington north to 35-40F over southeast IL with Lawrenceville near 40F. Arctic high pressure noses into the mid MS river valley tonight and brings fair skies and cold lows of 5-10F from Lincoln north and mid to upper teens in southeast IL. Clouds increase Monday morning ahead of northern stream clipper system which digs into the Midwest Monday night. Slowed down chances of light snow Monday afternoon as central IL appear dry through sunset Monday with best chances of light snow arriving Monday night northern half of CWA. Generally less than 1 inch of snow with northern IL having as much as 1-2 inches of snow possible. Highs Monday again in mid 20s north and mid to upper 30s in southeast IL. Lows Monday night in the teens central IL and lower 20s southeast IL. Chances of light snow NE of central IL by Tuesday morning. Highs Tue range from lower 20s northern areas to mid 30s in southeast IL. Core of arctic high pressure settles into MO by 18Z/noon Wed and brings even colder air into the region during middle of the week. Lows overnight Tue night into early Wed morning could reach zero to 5 below NW of IL river with single digit lows over much of central IL and far southeast IL around 10F. Highs Wed in the mid teens NE to lower 20s SW and SE areas. Lows Wed night again in the single digits over northern half of CWA and lower teens south. LONG TERM...Thursday through Saturday night Temps modify slightly during end of week but still average below normal through next weekend. The 8-14 day outlook for Mar 2-8 has 60-70% chance of below normal temperatures and 40% chance of above normal precipitation, which has been the normal for this winter. Generally dry and cold conditions expected late this week into next weekend. Though ECMWF and GEM models show some light QPF Friday while heavier QPF passes south of IL Friday. GFS model is dry over IL on Friday. Stayed close to ALLblend pops late this week and into the weekend which is dry. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1114 AM CST SUN FEB 23 2014 .UPDATE... ISSUED AT 516 AM CST SUN FEB 23 2014 RADAR TRENDS THE PAST SEVERAL HOURS SHOW A SLOW WEAKENING OF RETURNS ACROSS NORTHERN MISSOURI. KSTJ AND KCNK HAVE BEEN THE ONLY OBSERVATION SITES THAT HAVE REPORTED ANY SNOW. RAP MODEL TRENDS CONTINUE TO SHOW A SUBSTANTIAL DRY LAYER BELOW 850MB IN THE FORECAST SOUNDINGS. A COUPLE OF FLURRIES CANNOT BE RULED OUT SOUTH OF A KTVK TO KMQB LINE EARLY THIS MORNING. BASED ON RADAR TRENDS...A DRY FORECAST STILL LOOKS REASONABLE. && .SYNOPSIS... ISSUED AT 300 AM CST SUN FEB 23 2014 06Z SFC ANALYSIS HAS A FRONTAL BOUNDARY FROM THE OHIO VALLEY INTO THE SOUTHERN PLAINS. A WEAK TROF RAN THROUGH THE GREAT LAKES WHILE HIGH PRESSURE WAS OVER THE NORTHERN PLAINS. DEW POINTS WERE IN THE SINGLE DIGITS AND TEENS FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST WITH 20S AND 30S FROM THE SOUTHERN GREAT LAKES AND OHIO VALLEY INTO THE REMAINDER OF THE PLAINS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 300 AM CST SUN FEB 23 2014 THE NEXT WEAK DISTURBANCE ALOFT IS MOVING FROM THE PLAINS INTO THE LOWER MISSOURI VALLEY. ALTHOUGH RADAR RETURNS LOOK IMPRESSIVE...NO REPORTING STATION INDICATES PRECIPITATION REACHING THE GROUND. FORECAST SOUNDINGS INDICATE A VERY DRY ATMOSPHERE WILL REMAIN IN PLACE ACROSS THE AREA TODAY AND TONIGHT AS HIGH PRESSURE SLOWLY BUILDS INTO THE MIDWEST. AT THE VERY WORST A FEW FLURRIES MIGHT BE SEEN ACROSS THE EXTREME SOUTHERN AREAS EARLY THIS MORNING. OTHERWISE DRY CONDITIONS WILL BE SEEN ACROSS THE AREA TODAY AND TONIGHT. TEMPERATURES WILL AVERAGE BELOW NORMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 300 AM CST SUN FEB 23 2014 CONTINUED VERY COLD WITH NEAR RECORD LOW TEMPERATURES WITH LIGHT SNOW LIKELY MANY AREAS ON MONDAY. OVERVIEW...LITTLE SENSIBLE WEATHER ISSUES BESIDES LIGHT SNOW AND FLURRIES WITH NEXT INFUSION OF ARCTIC AIR ARRIVING ON MONDAY. LOW LEVEL THERMAL AND MOISTURE FIELDS SUGGESTS A 70/30 MIX OF HI-RES ECMWF WITH GFS. DEEP NW CYCLONIC FLOW KEEPS ARCTIC AIR IN PLACE DAYS 2 THROUGH 7 WITH LITTLE SENSIBLE WEATHER ISSUES. LOW LEVEL THERMAL FIELDS SUPPORT NEAR RECORD TO RECORD LOW MINS WEDNESDAY AM AND POSSIBLY AGAIN TOWARD FRIDAY DEPENDING ON HIGH PRESSURE TRACKS. MONDAY...UPPED POPS TO LIKELY...MOSTLY MONDAY EVENING WITH CENTRAL 1/3 OR MORE OF FORECAST AREA TO RECEIVE 2 TO 3 HOURS OF LIGHT SNOW AS WEAK DISTURBANCE PASSES. LOCAL TOOLS AND TECHNIQUES SUGGEST .5 TO LOCALLY NEAR 1 INCH OF A POWDERY DRY SNOW WITH LWE OF 20:1 OR MORE. FAR NORTH AND SOUTH SECTIONS MAY RECEIVE MORE OF A DUSTING OF FLURRIES. TEMPERATURES IN THE TEENS NORTH TO MID/UPPER 20S FAR SOUTH SECTIONS. MONDAY NIGHT...LOWS AS A CHALLENGE AS CLEARING SHOULD OCCUR AFTER MIDNIGHT NW TO NEAR DAYBREAK SE SECTIONS. HENCE...MINS NEAR ZERO ARE SUGGESTED TO MID TEENS SE SECTIONS. LATER SHIFTS MAY NEED TO CHANGE THESE VALUES BY 5+ DEGREES IF CLEARING IS EARLIER OR DELAYED. TUESDAY...MUCH COLDER AIR TO RESULT IN NEARLY STEADY TEMPERATURES WITH NW WINDS OF 10 TO 20 MPH TO KEEP WIND CHILLS IN SINGLE DIGITS SE TO NEGATIVE SINGLE DIGITS NW SECTIONS DESPITE FAIR SKIES. TUESDAY NIGHT...WINDS TO BECOME NEARLY CALM TOWARD DAYBREAK WITH STRONG AND SHALLOW INVERSION. LOWS SHOULD BE NEAR OR BREAK RECORDS AS DESCRIBED IN CLIMATE SECTION BELOW. THIS SUPPORTS -13 TO +4 SE WITH FAVORED LOCATIONS MAY NEED TO TRIMMED EVEN FURTHER BY 2 TO 5 DEGREES IF SEVERAL HOURS OF CALM TO NEARLY CALM WINDS AND CLEAR SKIES OCCUR. THIS MAY RESULT IN WIND CHILLS WELL BELOW -20 DEGREES INTO LATE MORNING. WEDNESDAY THROUGH SATURDAY...CONTINUED QUITE COLD AND FAIR TO MOSTLY FAIR AND GENERALLY DRY WITH LOWS WELL BELOW NORMAL BY 15 TO 20 DEGREES. THIS SUPPORTS HIGHS MOSTLY IN THE TEENS WITH SOME UPPER SINGLE DIGITS POSSIBLE NORTH AND LOWS SINGLE DIGITS AND POSSIBLY WELL INTO THE NEGATIVE SINGLE DIGITS NORTH SECTIONS. NEXT WAVE OFF CALIFORNIA MAY REQUIRE ADDING SNOW FRIDAY NIGHT AND ESPECIALLY SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1109 AM CST SUN FEB 23 2014 A STALLED RIDGE OF HIGH PRESSURE WILL KEEP VFR CONDITIONS IN PLACE THROUGH MONDAY MORNING. AN UPPER LEVEL DISTURBANCE WILL RACE OUT OF THE NORTHERN ROCKIES AND THROUGH THE PLAINS TONIGHT AND MONDAY SPREADING LIGHT SNOW OVER REGION MONDAY AFTERNOON AND EVENING CAUSING A DETERIORATION IN FLIGHT CONDITIONS. && .CLIMATE... ISSUED AT 300 AM CST SUN FEB 23 2014 RECORD LOWS FOR FEBRUARY 26... MOLINE.........-14 IN 1963 CEDAR RAPIDS...-08 IN 1950 DUBUQUE........-10 IN 1980 BURLINGTON.....-11 IN 1950 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...08 SHORT TERM...08 LONG TERM...NICHOLS AVIATION...DLF CLIMATE...NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1225 PM MST SUN FEB 23 2014 .UPDATE... ISSUED AT 1225 PM MST SUN FEB 23 2014 HAVE CANCELLED THE DENSE FOG ADVISORY AS VISIBILITIES HAVE IMPROVED A BIT ABOVE 1/4 MILE. FREEZING DRIZZLE BEING REPORTED...SEEMS TO BE CONFINED TO AREAS WHERE SFC RH ABOVE 90-95 PERCENT SO HAVE INCLUDED. TO THE EAST DRIER AIR AND HIGHER T/TD SPREADS ARE LIMITING FREEZING DRIZZLE POTENTIAL. MAY SEE ANOTHER HOUR OR TWO OF FREEZING DRIZZLE BEFORE THINGS COME TO AN END FOR TODAY. NOT MUCH HAS CHANGED WITH MAX TEMPS TODAY IN THE MID 20S WITH LOW 30S ACROSS THE FAR SOUTHWEST THROUGH WEST. UPDATE ISSUED AT 1009 AM MST SUN FEB 23 2014 CONDITIONS HAVE NOT CHANGED OVER THE PAST HOUR AND A HALF AND 15Z RUC CONTINUES TO SUPPORT WIDESPREAD LOW CLOUDS WITH FOG ACROSS THE AREA FOR THE REST OF THE DAY. HAVE ADJUSTED GRIDS ACCORDINGLY. IN THE GOODLAND AREA VISIBILITIES CONTINUE AROUND ONE QUARTER MILE WITH WEB CAMS AND METARS AROUND THE AREA SHOWING VISIBILITIES HIGHER. SINCE CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH HAVE GONE AHEAD AND ISSUED A DENSE FOG ADVISORY FOR SHERMAN COUNTY TIL 20Z. MAY HAVE TO GO LONGER BUT WILL WAIT AND SEE ON THAT. UPDATE ISSUED AT 850 AM MST SUN FEB 23 2014 ENTIRE FORECAST AREA ENTRENCHED IN STRATUS THIS MORNING WITH EAST/NORTHEAST WINDS EAST OF THE CO/KS BORDER AND SOUTHEAST WINDS ACROSS FAR EASTERN COLORADO. FOG ALSO BEING REPORTED ACROSS THE WESTERN 2/3 OF THE AREA WITH LOCALLY DENSE FOG IN THE GOODLAND AREA. LATEST RUC HAS AN EXCELLENT GRASP OF THE STRATUS AND PER THE 12Z RUN KEEPS IT OVER THE AREA FOR THE ENTIRE DAY. THE HRRR BREAKS UP THE STRATUS OVER PARTS OF FAR EASTERN COLORADO BUT KEEPS IT OVER THE REST OF THE AREA THROUGH THE DAY AS WELL. SHOULD THESE SCENARIOS VERIFY TEMPERATURES WONT MOVE MUCH FROM WHERE THEY ARE NOW AND WOULD BE SEVERAL DEGREES BELOW PREVIOUS FORECAST. 12Z NAM BOUNDARY LAYER RH ALSO HAD A GOOD HANDLE ON AREAL COVERAGE OF STRATUS BUT BY 18Z LIFTS IT/DISSIPATES IT FROM SOUTH TO NORTH ALLOWING MORE HEATING AND WARMER TEMPERATURES THAN THE RUC/HRRR. FOR THE FIRST OF WHAT WILL LIKELY BE SEVERAL UPDATES HAVE TRENDED TOWARD THE RUC/HRRR GIVEN THE EASTERLY COMPONENT TO THE WINDS ALL DAY WHICH IS NOT REAL FAVORABLE FOR RAPID STRATUS DISSIPATION AS THE NAM WOULD SUGGEST. HAVE LOWERED HIGH TEMPERATURES TO THE MID/UPPER 20S ACROSS THE NORTHEAST AND EAST (WHERE LOW CLOUDS EXPECTED LONGER) AND LOW TO MID 30S ACROSS THE FAR SOUTH THROUGH SOUTHWEST AND WEST WHERE SOME DISSIPATION WOULD BE MOST LIKELY BUT NOT CERTAIN AT THIS POINT. HAVE ALSO BEEFED UP THE FOG PER LOCAL OBSERVATIONS. NONE OF THE MODELS HANDLING THIS VERY WELL...HOPEFULLY THE 15Z RUC WILL LATCH ON TO IT AND GIVE SOME BETTER GUIDANCE. MORE UPDATES LIKELY TO COME LATER. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 314 AM MST SUN FEB 23 2014 UPPER FLOW WILL BE NORTHWEST THROUGH TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL BE OVER THE REGION TODAY AND TONIGHT. HIGH PRESSURE WILL DRIFT EAST MONDAY AS LOW PRESSURE MOVES INTO EASTERN COLORADO. A COLD FRONT WILL PUSH SOUTH MONDAY NIGHT FOLLOWED BY HIGH PRESSURE TUESDAY AND TUESDAY NIGHT. CURRENT RADAR SHOWING DECREASING TREND OF SNOW RETURNS OVER THE NORTH IN THE CURRENT WINTER WEATHER ADVISORY. FRONTOGENESIS EXITS THE AREA AND DO NOT EXPECT ANYTHING MORE THAN LIGHT SNOW THIS MORNING AND EVEN LESS OF AN AREA THIS AFTERNOON AS DYNAMICS MOVE OUT OF THE AREA. PLAN TO CANCEL THE WINTER WEATHER ADVISORY AT ZONES ISSUANCE. DEWPOINT DEPRESSIONS ARE NARROWING TO LESS THAN 3 DEGREES AND BOUNDARY LAYER RH IS PROGGED TO INCREASE TO OVER 90 PERCENT SO HAVE INCLUDED SOME PATCHY FREEZING FOG THIS MORNING OVER ALL BUT THE NORTHEAST FA. FORECAST SOUNDINGS ACROSS THE FA TONIGHT INDICATE THE POSSIBILITY OF SOME STRATUS AND FOG BUT MOISTURE IS TOO SHALLOW TO INDICATE FREEZING DRIZZLE. PLAN TO PULL THE FREEZING DRIZZLE AND CONSIDER SOME MENTION OF FOG OVERNIGHT INTO MONDAY MORNING. POPS WILL BE NIL MONDAY DUE TO SUBSIDENCE AND LACK OF MOISTURE. THERE IS SOME WEAK FORCING ACROSS THE NORTHERN ZONES MONDAY NIGHT/TUESDAY MORNING AND MOISTURE INCREASES SO CANNOT RULE OUT A SLIGHT CHANCE OF LIGHT SNOW OR FLURRIES. FOR TUESDAY AFTERNOON/TUESDAY NIGHT...THE GFS IS FASTER WITH BRINGING DYNAMICS INTO THE FA THAN THE NAM. FOR NOW WILL OPT FOR THE GFS TO STAY CONSISTENT WITH SURROUNDING OFFICES. HOWEVER DUE TO THE TIMING DIFFERENCES WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE RANGE. MAX TEMPERATURES TODAY WILL BE IN THE MID 30S EXCEPT FOR WESTERN PORTIONS OF EASTERN COLORADO WHERE SOME LOWER 40S WILL BE POSSIBLE. TEMPERATURES WILL WARM INTO THE 40S WITH SOME MID 50S POSSIBLE IN THE SOUTHWEST PORTION OF THE FA. TUESDAY WILL BE COLDER BEHIND THE FRONT WITH READINGS IN THE UPPER 20S AND LOW 30S. MIN TEMPERATURES TONIGHT WILL FALL INTO THE LOWER 20S AND INTO THE TEENS MONDAY AND TUESDAY NIGHTS. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 236 AM MST SUN FEB 23 2014 A RETURN OF BELOW NORMAL TEMPERATURES WILL BE THE MAIN CHARACTERISTIC OF THE EXTENDED FORECAST WITH A FEW PERIODS OF SNOW POSSIBLE. MODELS INDICATE THAT NORTHWEST FLOW IS THE PRIMARY UPPER LEVEL PATTERN ACROSS THE TRI-STATE AREA WITH A LARGE TROUGH OVER THE EASTERN UNITED STATES AND A RIDGE TO THE WEST. WITH THIS PATTERN IN PLACE...THE GATE IS OPEN FOR COLD CANADIAN AIR TO MOVE IN. THIS PATTERN IS SIMILAR TO THE EXTENDED VERY COLD OUTBREAK OBSERVED EARLIER THIS MONTH. THE COLD WEATHER IS NOT EXPECTED TO REACH THAT EXTENT AGAIN BUT WELL BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED. THE FORECAST INITIALIZATION PROCEDURE PROVIDED TEMPERATURES THAT SEEMED UNREASONABLY WARM FOR THIS TYPE OF PATTERN. THE EUROPEAN SEEMS MOST REASONABLE AND IS SUPPORTED BY THE CANADIAN MODEL. THE OPERATIONAL GFS HAS 850 MB TEMPS IN THE SAME BALLPARK AS THE EUROPEAN HOWEVER MEX GUIDANCE IS 10 TO NEARLY 20 DEGREES WARMER FOR FRIDAY AND SATURDAY. AS A RESULT...TEMPERATURES WERE NUDGED DOWN A FEW DEGREES BUT FORECAST IS STILL PROBABLY TOO WARM. AS FOR PRECIPITATION...THERE ARE TWO CHANCES AT WINTRY PRECIP DURING THE EXTENDED PERIOD. FOR WEDNESDAY...THE UPPER LEVEL DISTURBANCE THAT WILL BRING SNOW FOR TUESDAY NIGHT SHOULD BE CLEAR OF THE REGION WITH HIGH PRESSURE BUILDING IN. ADVERTISED DRY CONDITIONS FOR WEDNESDAY BUT A FEW FLURRIES MAY LINGER DEPENDING ON SPEED AND MOVEMENT OF THIS SYSTEM. THE FIRST CHANCE FOR PRECIPITATION IN THE EXTENDED FORECAST IS ANTICIPATED ON THURSDAY NIGHT INTO FRIDAY. THIS CHANCE COMES AS A STRONGER DISTURBANCE IN THE NORTHWEST FLOW TRANSITIONS ACROSS THE REGION. MODELS DISAGREE SOMEWHAT IN THE PLACEMENT AND MOVEMENT OF THIS SYSTEM SO HAVE ONLY GONE SLIGHT CHANCE TO LOW CHANCE POPS FOR THURSDAY NIGHT. DUE TO THE SPEED OF THIS SYSTEM...AN EXTENDED PERIOD OF ACCUMULATING SNOW IS NOT EXPECTED. IT IS ALSO POSSIBLE THIS SYSTEM MOVES SOUTH OF THE AREA WITH NO SNOW AS THE BEST FORCING APPEARS TO REMAIN SOUTH. THE SECOND...MORE SIGNIFICANT CHANCE OF PRECIPITATION COMES FOR NEXT WEEKEND. THROUGH 00Z SATURDAY...THE EUROPEAN...CANADIAN AND GFS MODELS ARE IN DECENT AGREEMENT ON A 500 MB LOW COMING INTO CALIFORNIA. THE GFS AND EUROPEAN MODELS THEN BRING THIS SYSTEM ACROSS THE ROCKIES ON SATURDAY AND INTO THE HIGH PLAINS SUNDAY. THESE TYPES OF SYSTEMS ARE TYPICALLY RESPONSIBLE FOR LARGER SNOW AMOUNTS SO WILL NEED TO MONITOR THIS SYSTEM CLOSELY. AS WITH ANY EXTENDED FORECAST...MODELS CAN AND OFTEN DO CHANGE THEIR SOLUTIONS THIS FAR OUT. HOWEVER...WITH BOTH MODELS PICKING UP ON IT AND PROJECTING A SIMILAR SOLUTION...THIS MAY HAVE A LITTLE MORE WEIGHT TO IT THAN A TYPICAL EXTENDED FORECAST STORM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1031 AM MST SUN FEB 23 2014 THIS TAF PERIOD WILL BE A MESSY ONE AS A STATIONARY FRONT TO THE WEST OF THE TRI STATE AREA WILL KEEP CONDITIONS OVERCAST THROUGH MOST OF THE TAF PERIOD FOR BOTH TERMINALS. PINNING DOWN VISIBILITIES FOR KGLD AND CEILING HEIGHTS FOR BOTH TERMINALS WAS A BIT TOUGH WITH MODEL GUIDANCE DIFFERING A LOT. REDUCED VISIBILITIES EXPECTED TO CONTINUE AT KGLD FOR THE REST OF THE MORNING AND INTO THE EARLY AFTERNOON HOURS BEFORE CONDITIONS IMPROVE TO MVFR. A BRIEF BREAK WILL OCCUR AROUND SUNDOWN WITH IMPROVED CONDITIONS BEFORE OVERCAST CONDITIONS AND REDUCED VISIBILITIES RETURN FOR OVERNIGHT. OVERCAST CONDITIONS AT KMCK WILL CONTINUE INTO TONIGHT. SOME AREAS OF PATCHY FOG AROUND THE TERMINAL WILL DEVELOP...SO MENTIONED MVFR CONDITIONS FOR VISIBILITY. CONDITIONS WILL IMPROVE TO VFR BY MID MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...FS LONG TERM...RRH AVIATION...MK
AREA FORECAST DISCUSSION
NWS WICHITA KS
1213 PM CST SUN FEB 23 2014 ...UPDATED FOR AVIATION DISCUSSION... .UPDATE... ISSUED AT 1210 PM CST SUN FEB 23 2014 STRATUS DECK THAT COVERS NORTHERN TWO-THIRDS OF KANSAS NOT BEING HANDLED WELL BY LARGER-SCALE MODELS...THOUGH RUC AND HRRR APPEAR TO BE CAPTURING THE SITUATION THE BEST. PERSISTENT CLOUDS WILL HAVE IMPACT ON TEMPERATURES AND WINDS...AND HAVE ADJUSTED BOTH DOWNWARD...FOR NORTH CENTRAL COUNTIES IN THE CWA. RUC LOW LEVEL RH/ISENTROPIC FIELDS SUGGESTS EDGE OF CLOUD DECK TO REMAIN NORTH AND WEST OF WICHITA/NE I-35 CORRIDOR...SO ONLY MINOR CHANGES IN FORECAST FOR SOUTH-CENTRAL AND SOUTHEAST PORTIONS OF THE CWA. SF && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 343 AM CST SUN FEB 23 2014 A SHORTWAVE TROUGH WAS MOVING EAST-SOUTHEAST ACROSS THE CENTRAL ROCKIES AND INTO THE CENTRAL PLAINS EARLY THIS MORNING WHILE AN EXPANSIVE AREA OF MID-LEVEL FRONTOGENESIS WAS PRESENT DOWNSTREAM ALONG THE KANSAS AND NEBRASKA STATE LINE. THIS WAS SUPPORTING A LARGE AREA OF LIGHT SNOW WHICH IS EXPECTED TO REMAIN NORTH OF THE FORECAST AREA BEFORE DIMINISHING TOWARD THE MIDDLE OF THE DAY. AT THE SURFACE, A COLD FRONT WAS LOCATED ACROSS THE SOUTHERN PLAINS WHILE NORTHEAST WINDS RESULTED IN LOW LEVEL COLD AIR ADVECTION ACROSS ALL OF THE CENTRAL PLAINS STATES. THIS WILL RESULT IN BELOW NORMAL TEMPERATURES RETURNING TO THE FORECAST AREA TODAY. THE INITIAL COOL DOWN WILL BE SHORT-LIVED AS SOUTHERLY FLOW RETURNS TO THE CENTRAL PLAINS ON MONDAY ALLOWING TEMPERATURES TO RETURN TO SEASONABLE VALUES IN THE UPPER 40S/AROUND 50. A PROGRESSIVE NORTHWEST MID/UPPER LEVEL FLOW REGIME WILL DRIVE ANOTHER CLIPPER SYSTEM ACROSS THE NORTHERN PLAINS LATE MONDAY SENDING ANOTHER SURGE OF MODIFIED ARCTIC AIR SOUTH ACROSS THE CENTRAL PLAINS INTO TUESDAY. HIGHS MAY STRUGGLE TO REACH 30 ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS WHILE SOUTHEAST KANSAS MAY CLIMB TO NEAR 40. A SUBTLE SHORTWAVE TROUGH MAY ALLOW FOR A PERIOD OF LIGHT SNOW OR FLURRIES ON TUESDAY HOWEVER CONFIDENCE REMAINS TOO LOW TO INCREASE POPS UP AT THIS TIME. SURFACE HIGH PRESSURE WILL SETTLE OVER THE AREA TUESDAY NIGHT ALLOWING FOR STRONG RADIATIONAL COOLING AND TRENDED LOWS DOWN WITH VALUES IN THE TEENS ANTICIPATED. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 343 AM CST SUN FEB 23 2014 MODERATING TEMPERATURES ARE EXPECTED WED-THU AS NORTHWEST MID/UPPER FLOW PREVAILS ACROSS THE CENTRAL CONUS. THE MID/UPPER RIDGE ANCHORED ACROSS THE SOUTHWEST IS PROGGED TO FLATTEN ON THURSDAY AS A MORE VIGOROUS TROUGH MOVES OVER THE GREAT BASIN AREA. ANOTHER COLD FRONT IS PROGGED TO MOVE SOUTH ACROSS THE NORTHERN AND CENTRAL PLAINS ON THURSDAY BRINGING AN END TO THE WARMING TREND ALTHOUGH THE CHANCES FOR MEASURABLE PRECIPITATION APPEAR TO REMAIN LOW AT THIS TIME. THERE REMAINS SOME POTENTIAL FOR LIGHT PRECIPITATION BUT HIGHER PROBABILITIES APPEAR TO REMAIN SOUTH AND EAST OF THE AREA AND MAINTAINED A SEASONABLY COOL AND DRY FORECAST FOR NOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1210 PM CST SUN FEB 23 2014 MVFR CIGS WILL LINGER AT KRSL...KSLN AND KHUT FOR HALF OR MORE OF THE FIRST PERIOD OF THE FORECAST CYCLE. PERISTENT STRATUS DECK THAT ENVELOPES THE NORTHERN TWO-THIRDS OF KANSAS... NOT HANDLED WELL BY MAJORITY OF FORECAST MODELS...BUT AS MENTIONED IN UPDATE SECTION...BOTH RUC/HRRR APPEAR TO REINITALIZED AND CAPTURED SITUATION. LATEST VISIBLE IMAGERY SHOWING SOME BREAKS IN THE STRATUS...BUT TRENDED TOWARD MORE PESSIMISTIC SOLUTION OF KEEPING MVFR CIGS AT KRSL...KSLN AND KHUT THROUGH 22-23 UTC. AS SURFACE /LOW-LEVEL FLOW VEERS TO AN EASTERLY COMPONENT AFT 00 UTC...EXPECT CIGS TO RETREAT WEST OF AFOREMENTIONED TAF SITES. BY 06 UTC...EXPECT VFR CIGS AND VSBYS TO PREVAIL AT ALL TERMINAL SITES. NORTHEAST WINDS WILL VEER THROUGH THE FORECAST PERIOD...BECOMING EAST TO SOUTHEAST BY 12 UTC/24. SF && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 44 24 49 26 / 0 0 10 10 HUTCHINSON 38 20 48 24 / 0 10 10 10 NEWTON 40 22 46 24 / 0 10 10 10 ELDORADO 44 23 47 26 / 0 0 10 10 WINFIELD-KWLD 48 24 49 28 / 0 0 10 10 RUSSELL 33 22 49 19 / 10 10 10 10 GREAT BEND 34 20 50 22 / 10 10 10 10 SALINA 35 22 46 22 / 10 10 10 10 MCPHERSON 36 22 47 24 / 10 10 10 10 COFFEYVILLE 49 23 49 31 / 0 0 10 10 CHANUTE 45 23 46 26 / 0 10 10 10 IOLA 44 24 45 25 / 0 10 10 10 PARSONS-KPPF 48 23 48 28 / 0 0 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1101 AM MST SUN FEB 23 2014 .UPDATE... ISSUED AT 1009 AM MST SUN FEB 23 2014 CONDITIONS HAVE NOT CHANGED OVER THE PAST HOUR AND A HALF AND 15Z RUC CONTINUES TO SUPPORT WIDESPREAD LOW CLOUDS WITH FOG ACROSS THE AREA FOR THE REST OF THE DAY. HAVE ADJUSTED GRIDS ACCORDINGLY. IN THE GOODLAND AREA VISIBILITIES CONTINUE AROUND ONE QUARTER MILE WITH WEB CAMS AND METARS AROUND THE AREA SHOWING VISIBILITIES HIGHER. SINCE CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH HAVE GONE AHEAD AND ISSUED A DENSE FOG ADVISORY FOR SHERMAN COUNTY TIL 20Z. MAY HAVE TO GO LONGER BUT WILL WAIT AND SEE ON THAT. UPDATE ISSUED AT 850 AM MST SUN FEB 23 2014 ENTIRE FORECAST AREA ENTRENCHED IN STRATUS THIS MORNING WITH EAST/NORTHEAST WINDS EAST OF THE CO/KS BORDER AND SOUTHEAST WINDS ACROSS FAR EASTERN COLORADO. FOG ALSO BEING REPORTED ACROSS THE WESTERN 2/3 OF THE AREA WITH LOCALLY DENSE FOG IN THE GOODLAND AREA. LATEST RUC HAS AN EXCELLENT GRASP OF THE STRATUS AND PER THE 12Z RUN KEEPS IT OVER THE AREA FOR THE ENTIRE DAY. THE HRRR BREAKS UP THE STRATUS OVER PARTS OF FAR EASTERN COLORADO BUT KEEPS IT OVER THE REST OF THE AREA THROUGH THE DAY AS WELL. SHOULD THESE SCENARIOS VERIFY TEMPERATURES WONT MOVE MUCH FROM WHERE THEY ARE NOW AND WOULD BE SEVERAL DEGREES BELOW PREVIOUS FORECAST. 12Z NAM BOUNDARY LAYER RH ALSO HAD A GOOD HANDLE ON AREAL COVERAGE OF STRATUS BUT BY 18Z LIFTS IT/DISSIPATES IT FROM SOUTH TO NORTH ALLOWING MORE HEATING AND WARMER TEMPERATURES THAN THE RUC/HRRR. FOR THE FIRST OF WHAT WILL LIKELY BE SEVERAL UPDATES HAVE TRENDED TOWARD THE RUC/HRRR GIVEN THE EASTERLY COMPONENT TO THE WINDS ALL DAY WHICH IS NOT REAL FAVORABLE FOR RAPID STRATUS DISSIPATION AS THE NAM WOULD SUGGEST. HAVE LOWERED HIGH TEMPERATURES TO THE MID/UPPER 20S ACROSS THE NORTHEAST AND EAST (WHERE LOW CLOUDS EXPECTED LONGER) AND LOW TO MID 30S ACROSS THE FAR SOUTH THROUGH SOUTHWEST AND WEST WHERE SOME DISSIPATION WOULD BE MOST LIKELY BUT NOT CERTAIN AT THIS POINT. HAVE ALSO BEEFED UP THE FOG PER LOCAL OBSERVATIONS. NONE OF THE MODELS HANDLING THIS VERY WELL...HOPEFULLY THE 15Z RUC WILL LATCH ON TO IT AND GIVE SOME BETTER GUIDANCE. MORE UPDATES LIKELY TO COME LATER. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 314 AM MST SUN FEB 23 2014 UPPER FLOW WILL BE NORTHWEST THROUGH TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL BE OVER THE REGION TODAY AND TONIGHT. HIGH PRESSURE WILL DRIFT EAST MONDAY AS LOW PRESSURE MOVES INTO EASTERN COLORADO. A COLD FRONT WILL PUSH SOUTH MONDAY NIGHT FOLLOWED BY HIGH PRESSURE TUESDAY AND TUESDAY NIGHT. CURRENT RADAR SHOWING DECREASING TREND OF SNOW RETURNS OVER THE NORTH IN THE CURRENT WINTER WEATHER ADVISORY. FRONTOGENESIS EXITS THE AREA AND DO NOT EXPECT ANYTHING MORE THAN LIGHT SNOW THIS MORNING AND EVEN LESS OF AN AREA THIS AFTERNOON AS DYNAMICS MOVE OUT OF THE AREA. PLAN TO CANCEL THE WINTER WEATHER ADVISORY AT ZONES ISSUANCE. DEWPOINT DEPRESSIONS ARE NARROWING TO LESS THAN 3 DEGREES AND BOUNDARY LAYER RH IS PROGGED TO INCREASE TO OVER 90 PERCENT SO HAVE INCLUDED SOME PATCHY FREEZING FOG THIS MORNING OVER ALL BUT THE NORTHEAST FA. FORECAST SOUNDINGS ACROSS THE FA TONIGHT INDICATE THE POSSIBILITY OF SOME STRATUS AND FOG BUT MOISTURE IS TOO SHALLOW TO INDICATE FREEZING DRIZZLE. PLAN TO PULL THE FREEZING DRIZZLE AND CONSIDER SOME MENTION OF FOG OVERNIGHT INTO MONDAY MORNING. POPS WILL BE NIL MONDAY DUE TO SUBSIDENCE AND LACK OF MOISTURE. THERE IS SOME WEAK FORCING ACROSS THE NORTHERN ZONES MONDAY NIGHT/TUESDAY MORNING AND MOISTURE INCREASES SO CANNOT RULE OUT A SLIGHT CHANCE OF LIGHT SNOW OR FLURRIES. FOR TUESDAY AFTERNOON/TUESDAY NIGHT...THE GFS IS FASTER WITH BRINGING DYNAMICS INTO THE FA THAN THE NAM. FOR NOW WILL OPT FOR THE GFS TO STAY CONSISTENT WITH SURROUNDING OFFICES. HOWEVER DUE TO THE TIMING DIFFERENCES WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE RANGE. MAX TEMPERATURES TODAY WILL BE IN THE MID 30S EXCEPT FOR WESTERN PORTIONS OF EASTERN COLORADO WHERE SOME LOWER 40S WILL BE POSSIBLE. TEMPERATURES WILL WARM INTO THE 40S WITH SOME MID 50S POSSIBLE IN THE SOUTHWEST PORTION OF THE FA. TUESDAY WILL BE COLDER BEHIND THE FRONT WITH READINGS IN THE UPPER 20S AND LOW 30S. MIN TEMPERATURES TONIGHT WILL FALL INTO THE LOWER 20S AND INTO THE TEENS MONDAY AND TUESDAY NIGHTS. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 236 AM MST SUN FEB 23 2014 A RETURN OF BELOW NORMAL TEMPERATURES WILL BE THE MAIN CHARACTERISTIC OF THE EXTENDED FORECAST WITH A FEW PERIODS OF SNOW POSSIBLE. MODELS INDICATE THAT NORTHWEST FLOW IS THE PRIMARY UPPER LEVEL PATTERN ACROSS THE TRI-STATE AREA WITH A LARGE TROUGH OVER THE EASTERN UNITED STATES AND A RIDGE TO THE WEST. WITH THIS PATTERN IN PLACE...THE GATE IS OPEN FOR COLD CANADIAN AIR TO MOVE IN. THIS PATTERN IS SIMILAR TO THE EXTENDED VERY COLD OUTBREAK OBSERVED EARLIER THIS MONTH. THE COLD WEATHER IS NOT EXPECTED TO REACH THAT EXTENT AGAIN BUT WELL BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED. THE FORECAST INITIALIZATION PROCEDURE PROVIDED TEMPERATURES THAT SEEMED UNREASONABLY WARM FOR THIS TYPE OF PATTERN. THE EUROPEAN SEEMS MOST REASONABLE AND IS SUPPORTED BY THE CANADIAN MODEL. THE OPERATIONAL GFS HAS 850 MB TEMPS IN THE SAME BALLPARK AS THE EUROPEAN HOWEVER MEX GUIDANCE IS 10 TO NEARLY 20 DEGREES WARMER FOR FRIDAY AND SATURDAY. AS A RESULT...TEMPERATURES WERE NUDGED DOWN A FEW DEGREES BUT FORECAST IS STILL PROBABLY TOO WARM. AS FOR PRECIPITATION...THERE ARE TWO CHANCES AT WINTRY PRECIP DURING THE EXTENDED PERIOD. FOR WEDNESDAY...THE UPPER LEVEL DISTURBANCE THAT WILL BRING SNOW FOR TUESDAY NIGHT SHOULD BE CLEAR OF THE REGION WITH HIGH PRESSURE BUILDING IN. ADVERTISED DRY CONDITIONS FOR WEDNESDAY BUT A FEW FLURRIES MAY LINGER DEPENDING ON SPEED AND MOVEMENT OF THIS SYSTEM. THE FIRST CHANCE FOR PRECIPITATION IN THE EXTENDED FORECAST IS ANTICIPATED ON THURSDAY NIGHT INTO FRIDAY. THIS CHANCE COMES AS A STRONGER DISTURBANCE IN THE NORTHWEST FLOW TRANSITIONS ACROSS THE REGION. MODELS DISAGREE SOMEWHAT IN THE PLACEMENT AND MOVEMENT OF THIS SYSTEM SO HAVE ONLY GONE SLIGHT CHANCE TO LOW CHANCE POPS FOR THURSDAY NIGHT. DUE TO THE SPEED OF THIS SYSTEM...AN EXTENDED PERIOD OF ACCUMULATING SNOW IS NOT EXPECTED. IT IS ALSO POSSIBLE THIS SYSTEM MOVES SOUTH OF THE AREA WITH NO SNOW AS THE BEST FORCING APPEARS TO REMAIN SOUTH. THE SECOND...MORE SIGNIFICANT CHANCE OF PRECIPITATION COMES FOR NEXT WEEKEND. THROUGH 00Z SATURDAY...THE EUROPEAN...CANADIAN AND GFS MODELS ARE IN DECENT AGREEMENT ON A 500 MB LOW COMING INTO CALIFORNIA. THE GFS AND EUROPEAN MODELS THEN BRING THIS SYSTEM ACROSS THE ROCKIES ON SATURDAY AND INTO THE HIGH PLAINS SUNDAY. THESE TYPES OF SYSTEMS ARE TYPICALLY RESPONSIBLE FOR LARGER SNOW AMOUNTS SO WILL NEED TO MONITOR THIS SYSTEM CLOSELY. AS WITH ANY EXTENDED FORECAST...MODELS CAN AND OFTEN DO CHANGE THEIR SOLUTIONS THIS FAR OUT. HOWEVER...WITH BOTH MODELS PICKING UP ON IT AND PROJECTING A SIMILAR SOLUTION...THIS MAY HAVE A LITTLE MORE WEIGHT TO IT THAN A TYPICAL EXTENDED FORECAST STORM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1031 AM MST SUN FEB 23 2014 THIS TAF PERIOD WILL BE A MESSY ONE AS A STATIONARY FRONT TO THE WEST OF THE TRI STATE AREA WILL KEEP CONDITIONS OVERCAST THROUGH MOST OF THE TAF PERIOD FOR BOTH TERMINALS. PINNING DOWN VISIBILITIES FOR KGLD AND CEILING HEIGHTS FOR BOTH TERMINALS WAS A BIT TOUGH WITH MODEL GUIDANCE DIFFERING A LOT. REDUCED VISIBILITIES EXPECTED TO CONTINUE AT KGLD FOR THE REST OF THE MORNING AND INTO THE EARLY AFTERNOON HOURS BEFORE CONDITIONS IMPROVE TO MVFR. A BRIEF BREAK WILL OCCUR AROUND SUNDOWN WITH IMPROVED CONDITIONS BEFORE OVERCAST CONDITIONS AND REDUCED VISIBILITIES RETURN FOR OVERNIGHT. OVERCAST CONDITIONS AT KMCK WILL CONTINUE INTO TONIGHT. SOME AREAS OF PATCHY FOG AROUND THE TERMINAL WILL DEVELOP...SO MENTIONED MVFR CONDITIONS FOR VISIBILITY. CONDITIONS WILL IMPROVE TO VFR BY MID MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...DENSE FOG ADVISORY UNTIL 1 PM MST THIS AFTERNOON FOR KSZ013. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...FS LONG TERM...RRH AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1011 AM MST SUN FEB 23 2014 .UPDATE... ISSUED AT 1009 AM MST SUN FEB 23 2014 CONDITIONS HAVE NOT CHANGED OVER THE PAST HOUR AND A HALF AND 15Z RUC CONTINUES TO SUPPORT WIDESPREAD LOW CLOUDS WITH FOG ACROSS THE AREA FOR THE REST OF THE DAY. HAVE ADJUSTED GRIDS ACCORDINGLY. IN THE GOODLAND AREA VISIBILITIES CONTINUE AROUND ONE QUARTER MILE WITH WEB CAMS AND METARS AROUND THE AREA SHOWING VISIBILITIES HIGHER. SINCE CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH HAVE GONE AHEAD AND ISSUED A DENSE FOG ADVISORY FOR SHERMAN COUNTY TIL 20Z. MAY HAVE TO GO LONGER BUT WILL WAIT AND SEE ON THAT. UPDATE ISSUED AT 850 AM MST SUN FEB 23 2014 ENTIRE FORECAST AREA ENTRENCHED IN STRATUS THIS MORNING WITH EAST/NORTHEAST WINDS EAST OF THE CO/KS BORDER AND SOUTHEAST WINDS ACROSS FAR EASTERN COLORADO. FOG ALSO BEING REPORTED ACROSS THE WESTERN 2/3 OF THE AREA WITH LOCALLY DENSE FOG IN THE GOODLAND AREA. LATEST RUC HAS AN EXCELLENT GRASP OF THE STRATUS AND PER THE 12Z RUN KEEPS IT OVER THE AREA FOR THE ENTIRE DAY. THE HRRR BREAKS UP THE STRATUS OVER PARTS OF FAR EASTERN COLORADO BUT KEEPS IT OVER THE REST OF THE AREA THROUGH THE DAY AS WELL. SHOULD THESE SCENARIOS VERIFY TEMPERATURES WONT MOVE MUCH FROM WHERE THEY ARE NOW AND WOULD BE SEVERAL DEGREES BELOW PREVIOUS FORECAST. 12Z NAM BOUNDARY LAYER RH ALSO HAD A GOOD HANDLE ON AREAL COVERAGE OF STRATUS BUT BY 18Z LIFTS IT/DISSIPATES IT FROM SOUTH TO NORTH ALLOWING MORE HEATING AND WARMER TEMPERATURES THAN THE RUC/HRRR. FOR THE FIRST OF WHAT WILL LIKELY BE SEVERAL UPDATES HAVE TRENDED TOWARD THE RUC/HRRR GIVEN THE EASTERLY COMPONENT TO THE WINDS ALL DAY WHICH ISNT REAL FAVORABLE FOR RAPID STRATUS DISSIPATION AS THE NAM WOULD SUGGEST. HAVE LOWERED HIGH TEMPERATURES TO THE MID/UPPER 20S ACROSS THE NORTHEAST AND EAST (WHERE LOW CLOUDS EXPECTED LONGER) AND LOW TO MID 30S ACROSS THE FAR SOUTH THROUGH SOUTHWEST AND WEST WHERE SOME DISSIPATION WOULD BE MOST LIKELY BUT NOT CERTAIN AT THIS POINT. HAVE ALSO BEEFED UP THE FOG PER LOCAL OBSERVATIONS. NONE OF THE MODELS HANDLING THIS VERY WELL...HOPEFULLY THE 15Z RUC WILL LATCH ON TO IT AND GIVE SOME BETTER GUIDANCE. MORE UPDATES LIKELY TO COME LATER. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 314 AM MST SUN FEB 23 2014 UPPER FLOW WILL BE NORTHWEST THROUGH TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL BE OVER THE REGION TODAY AND TONIGHT. HIGH PRESSURE WILL DRIFT EAST MONDAY AS LOW PRESSURE MOVES INTO EASTERN COLORADO. A COLD FRONT WILL PUSH SOUTH MONDAY NIGHT FOLLOWED BY HIGH PRESSURE TUESDAY AND TUESDAY NIGHT. CURRENT RADAR SHOWING DECREASING TREND OF SNOW RETURNS OVER THE NORTH IN THE CURRENT WINTER WEATHER ADVISORY. FRONTOGENESIS EXITS THE AREA AND DO NOT EXPECT ANYTHING MORE THAN LIGHT SNOW THIS MORNING AND EVEN LESS OF AN AREA THIS AFTERNOON AS DYNAMICS MOVE OUT OF THE AREA. PLAN TO CANCEL THE WINTER WEATHER ADVISORY AT ZONES ISSUANCE. DEWPOINT DEPRESSIONS ARE NARROWING TO LESS THAN 3 DEGREES AND BOUNDARY LAYER RH IS PROGGED TO INCREASE TO OVER 90 PERCENT SO HAVE INCLUDED SOME PATCHY FREEZING FOG THIS MORNING OVER ALL BUT THE NORTHEAST FA. FORECAST SOUNDINGS ACROSS THE FA TONIGHT INDICATE THE POSSIBILITY OF SOME STRATUS AND FOG BUT MOISTURE IS TOO SHALLOW TO INDICATE FREEZING DRIZZLE. PLAN TO PULL THE FREEZING DRIZZLE AND CONSIDER SOME MENTION OF FOG OVERNIGHT INTO MONDAY MORNING. POPS WILL BE NIL MONDAY DUE TO SUBSIDENCE AND LACK OF MOISTURE. THERE IS SOME WEAK FORCING ACROSS THE NORTHERN ZONES MONDAY NIGHT/TUESDAY MORNING AND MOISTURE INCREASES SO CANNOT RULE OUT A SLIGHT CHANCE OF LIGHT SNOW OR FLURRIES. FOR TUESDAY AFTERNOON/TUESDAY NIGHT...THE GFS IS FASTER WITH BRINGING DYNAMICS INTO THE FA THAN THE NAM. FOR NOW WILL OPT FOR THE GFS TO STAY CONSISTENT WITH SURROUNDING OFFICES. HOWEVER DUE TO THE TIMING DIFFERENCES WILL KEEP POPS IN THE SLIGHT CHANCE/CHANCE RANGE. MAX TEMPERATURES TODAY WILL BE IN THE MID 30S EXCEPT FOR WESTERN PORTIONS OF EASTERN COLORADO WHERE SOME LOWER 40S WILL BE POSSIBLE. TEMPERATURES WILL WARM INTO THE 40S WITH SOME MID 50S POSSIBLE IN THE SOUTHWEST PORTION OF THE FA. TUESDAY WILL BE COLDER BEHIND THE FRONT WITH READINGS IN THE UPPER 20S AND LOW 30S. MIN TEMPERATURES TONIGHT WILL FALL INTO THE LOWER 20S AND INTO THE TEENS MONDAY AND TUESDAY NIGHTS. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 236 AM MST SUN FEB 23 2014 A RETURN OF BELOW NORMAL TEMPERATURES WILL BE THE MAIN CHARACTERISTIC OF THE EXTENDED FORECAST WITH A FEW PERIODS OF SNOW POSSIBLE. MODELS INDICATE THAT NORTHWEST FLOW IS THE PRIMARY UPPER LEVEL PATTERN ACROSS THE TRI-STATE AREA WITH A LARGE TROUGH OVER THE EASTERN UNITED STATES AND A RIDGE TO THE WEST. WITH THIS PATTERN IN PLACE...THE GATE IS OPEN FOR COLD CANADIAN AIR TO MOVE IN. THIS PATTERN IS SIMILAR TO THE EXTENDED VERY COLD OUTBREAK OBSERVED EARLIER THIS MONTH. THE COLD WEATHER IS NOT EXPECTED TO REACH THAT EXTENT AGAIN BUT WELL BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED. THE FORECAST INITIALIZATION PROCEDURE PROVIDED TEMPERATURES THAT SEEMED UNREASONABLY WARM FOR THIS TYPE OF PATTERN. THE EUROPEAN SEEMS MOST REASONABLE AND IS SUPPORTED BY THE CANADIAN MODEL. THE OPERATIONAL GFS HAS 850 MB TEMPS IN THE SAME BALLPARK AS THE EUROPEAN HOWEVER MEX GUIDANCE IS 10 TO NEARLY 20 DEGREES WARMER FOR FRIDAY AND SATURDAY. AS A RESULT...TEMPERATURES WERE NUDGED DOWN A FEW DEGREES BUT FORECAST IS STILL PROBABLY TOO WARM. AS FOR PRECIPITATION...THERE ARE TWO CHANCES AT WINTRY PRECIP DURING THE EXTENDED PERIOD. FOR WEDNESDAY...THE UPPER LEVEL DISTURBANCE THAT WILL BRING SNOW FOR TUESDAY NIGHT SHOULD BE CLEAR OF THE REGION WITH HIGH PRESSURE BUILDING IN. ADVERTISED DRY CONDITIONS FOR WEDNESDAY BUT A FEW FLURRIES MAY LINGER DEPENDING ON SPEED AND MOVEMENT OF THIS SYSTEM. THE FIRST CHANCE FOR PRECIPITATION IN THE EXTENDED FORECAST IS ANTICIPATED ON THURSDAY NIGHT INTO FRIDAY. THIS CHANCE COMES AS A STRONGER DISTURBANCE IN THE NORTHWEST FLOW TRANSITIONS ACROSS THE REGION. MODELS DISAGREE SOMEWHAT IN THE PLACEMENT AND MOVEMENT OF THIS SYSTEM SO HAVE ONLY GONE SLIGHT CHANCE TO LOW CHANCE POPS FOR THURSDAY NIGHT. DUE TO THE SPEED OF THIS SYSTEM...AN EXTENDED PERIOD OF ACCUMULATING SNOW IS NOT EXPECTED. IT IS ALSO POSSIBLE THIS SYSTEM MOVES SOUTH OF THE AREA WITH NO SNOW AS THE BEST FORCING APPEARS TO REMAIN SOUTH. THE SECOND...MORE SIGNIFICANT CHANCE OF PRECIPITATION COMES FOR NEXT WEEKEND. THROUGH 00Z SATURDAY...THE EUROPEAN...CANADIAN AND GFS MODELS ARE IN DECENT AGREEMENT ON A 500 MB LOW COMING INTO CALIFORNIA. THE GFS AND EUROPEAN MODELS THEN BRING THIS SYSTEM ACROSS THE ROCKIES ON SATURDAY AND INTO THE HIGH PLAINS SUNDAY. THESE TYPES OF SYSTEMS ARE TYPICALLY RESPONSIBLE FOR LARGER SNOW AMOUNTS SO WILL NEED TO MONITOR THIS SYSTEM CLOSELY. AS WITH ANY EXTENDED FORECAST...MODELS CAN AND OFTEN DO CHANGE THEIR SOLUTIONS THIS FAR OUT. HOWEVER...WITH BOTH MODELS PICKING UP ON IT AND PROJECTING A SIMILAR SOLUTION...THIS MAY HAVE A LITTLE MORE WEIGHT TO IT THAN A TYPICAL EXTENDED FORECAST STORM. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 438 AM MST SUN FEB 23 2014 SOME IFR AND LIFR CONDITIONS WILL CONTINUE THIS MORNING AT KGLD AND KMCK BEHIND AN EXITING SHORTWAVE. CONDITIONS SHOULD IMPROVE TO MVFR AT KGLD THIS AFTERNOON BUT WILL DROP BACK DOWN TO IFR TONIGHT AS FOG AND STRATUS OVERTAKE THE AREA. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...DENSE FOG ADVISORY FROM 6 PM TO 7 PM MST THIS EVENING FOR KSZ013. DENSE FOG ADVISORY UNTIL 1 PM MST THIS AFTERNOON FOR KSZ013. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...FS LONG TERM...RRH AVIATION...FS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
259 PM EST SUN FEB 23 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THIS EVENING BRINGING LIGHT RAIN AND LIGHT SNOW TO LOCATIONS SOUTH OF INTERSTATE 70. COLD WEATHER IS PREDICTED FOR MOST OF THE WEEK WITH A RETURN OF ARCTIC AIR. NO SIGNIFICANT SNOW ACCUMULATION IS FORECAST THIS WEEK. && .NEAR TERM /THROUGH MONDAY/... SURFACE TROUGH AXIS CONTINUES TO HAVE A TOUGH TIME SQUEEZING OUT MOISTURE. STILL FEEL WITH APPROACHING S/W TROUGH AND PASSAGE OF LOWER TROPOPAUSE HEIGHTS THAT LIGHT ACTIVITY IS A GOOD BET FOR A 3-5 HR WINDOW. TIGHTENED UP POP GRADIENT AND MAINTAINED LIGHT RA/SN QUALIFIER FOR LOCATIONS S OF I-70. USED HRRR TO PINPOINT HIGHEST POPS OF 22-03Z. QPF AMOUNTS WILL BE A FEW HUNDREDTHS AND EVEN WITH SNOW RATIOS HIGHER THAN CLIMO STILL THINK ANY LOCATION WILL BE HARD PRESSED TO GET MORE THAN AN INCH. A BREAK IN THE WEATHER OVERNIGHT THROUGH MOST OF MONDAY AS WE AWAIT MID LVL HEIGHT FALLS AND ACCOMPANYING MID LVL IMPULSE TO INVADE FROM THE N. CHC POPS N OF I-80 AT THIS TIME SEEM PRUDENT GIVEN QUESTIONABLE MOISTURE ESPECIALLY WITH A FROZEN LAKE ERIE. WINDS WILL BE THE MAIN STORY MONDAY WITH GUSTS ECLIPSING 20 MPH IN THE AFTERNOON. ICE JAMS REMAIN A CONCERN. WITH TEMPERATURES FALLING BELOW FREEZING THIS EVENING AND CONTINUING THE NEXT SEVERAL DAYS THE THREAT OF ICE JAM FLOODING WILL DECREASE. ONLY TO AGAIN BE RE- VISITED IN MARCH WHEN WE WARM WELL ABOVE FREEZING. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... LOW CONFIDENCE IN THE SHORT TERM PERIOD WITH SEVERAL ROUNDS OF SNOW SHOWERS POSSIBLE TUES AND THEN AGAIN WEDS. MODELS STILL HAVING A DIFFICULT TIME IN HANDLING THESE SHORTWAVES...ESPECIALLY THE WEDS SYSTEM. THE NAM/GFS IS A LITTLE SLOWER AND LESS PROGRESSIVE THAN THE SREF/ECMWF SOLNS. STICKING WITH MORE OF A BLEND THAN DETERMINISTIC APPROACH WITH THIS UPDATE...LIMITING SNOW SHOWER PROBABILITIES TO THE CHC RANGE. WITH OUR AREA REMAINING UNDER THE INFLUENCE OF THE BROAD TROUGH OVER THE ERN CONUS...NW FLOW ALOFT WILL KEEP TEMPERATURES COLDER THAN AVERAGE. WILL REMAIN ON THE COLDER SIDE OF GUIDANCE THROUGH MIDWEEK. && .LONG TERM /THURSDAY THROUGH SUNDAY/... WINTER CONTINUES IN THE LONG TERM. ONCE AGAIN...ARCTIC AIR WILL SETTLE IN THE EAST FOR THE SECOND HALF OF THE WEEK. REALLY NO SYSTEMS TO HIT ON FOR PRECIP...JUST THE CROSSING OF A WEAK FRONT THURSDAY. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... HIGH CONFIDENCE FORECAST. VFR CONDITIONS WILL CONTINUE THROUGH THE NEXT 24 HOURS...SAVE FOR BVI WHERE BKN STRATOCU WILL OCCUR THROUGH THE EARLY AFTERNOON. A COLD FRONT WILL CROSS THE REGION WITH LITTLE FAN FAR AT AREA TERMINALS. MOST LIKELY IMPACTED LOCATIONS ARE MGW/LBE WHERE VFR -RASN COULD OCCUR BTWN 20Z-0Z. TONIGHT ALL TERMINALS RETURN TO VFR UNDER A BKN MID DECK WHICH WILL YIELD TO SCT CI. WINDS WILL INCREASE MONDAY MORNING WITH THE APPROACH OF AN UPPER AIR SYSTEM DIVING DOWN FROM THE GREAT LAKES. GUSTS COULD EXCEED 20KTS AT FKL AND DUJ. .OUTLOOK..../18Z MONDAY THROUGH FRIDAY/... THE PASSING OF A STRONG UPPER AIR DISTURBANCE TUESDAY NIGHT INTO WEDNESDAY WILL BRING RESTRICTIONS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
229 PM EST SUN FEB 23 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THIS EVENING BRINGING LIGHT RAIN AND LIGHT SNOW TO LOCATIONS SOUTH OF INTERSTATE 70. COLD WEATHER IS PREDICTED FOR MOST OF THE WEEK WITH A RETURN OF ARCTIC AIR. NO SIGNIFICANT SNOW ACCUMULATION IS FORECAST THIS WEEK. && .NEAR TERM /THROUGH MONDAY/... SURFACE TROUGH AXIS CONTINUES TO HAVE A TOUGH TIME SQUEEZING OUT MOISTURE. STILL FEEL WITH APPROACHING S/W TROUGH AND PASSAGE OF LOWER TROPOPAUSE HEIGHTS THAT LIGHT ACTIVITY IS A GOOD BET FOR A 3-5 HR WINDOW. TIGHTENED UP POP GRADIENT AND MAINTAINED LIGHT RA/SN QUALIFIER FOR LOCATIONS S OF I-70. USED HRRR TO PINPOINT HIGHEST POPS OF 22-03Z. QPF AMOUNTS WILL BE A FEW HUNDREDTHS AND EVEN WITH SNOW RATIOS HIGHER THAN CLIMO STILL THINK ANY LOCATION WILL BE HARD PRESSED TO GET MORE THAN AN INCH. A BREAK IN THE WEATHER OVERNIGHT THROUGH MOST OF MONDAY AS WE AWAIT MID LVL HEIGHT FALLS AND ACCOMPANYING MID LVL IMPULSE TO INVADE FROM THE N. CHC POPS N OF I-80 AT THIS TIME SEEM PRUDENT GIVEN QUESTIONABLE MOISTURE ESPECIALLY WITH A FROZEN LAKE ERIE. WINDS WILL BE THE MAIN STORY MONDAY WITH GUSTS ECLIPSING 20 MPH IN THE AFTERNOON. ICE JAMS REMAIN A CONCERN. WITH TEMPERATURES FALLING BELOW FREEZING THIS EVENING AND CONTINUING THE NEXT SEVERAL DAYS THE THREAT OF ICE JAM FLOODING WILL DECREASE. ONLY TO AGAIN BE RE- VISITED IN MARCH WHEN WE WARM WELL ABOVE FREEZING. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/... LOW CONFIDENCE FOR TUESDAY`S FORECAST DUE TO DIFFERING MODEL SOLUTIONS WITH ANOTHER UPPER LEVEL WAVE. WILL GO WITH A MIDDLE OF THE ROAD FORECAST...MEANING CHANCE POPS FOR SNOW SHOWERS. AREA WILL BE WELL BACK INTO THE COLD PATTERN BY TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... WINTER CONTINUES IN THE LONG TERM. ONCE AGAIN...ARCTIC AIR WILL SETTLE IN THE EAST FOR THE SECOND HALF OF THE WEEK. REALLY NO SYSTEMS TO HIT ON FOR PRECIP...JUST THE CROSSING OF A WEAK FRONT THURSDAY. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... HIGH CONFIDENCE FORECAST. VFR CONDITIONS WILL CONTINUE THROUGH THE NEXT 24 HOURS...SAVE FOR BVI WHERE BKN STRATOCU WILL OCCUR THROUGH THE EARLY AFTERNOON. A COLD FRONT WILL CROSS THE REGION WITH LITTLE FAN FAR AT AREA TERMINALS. MOST LIKELY IMPACTED LOCATIONS ARE MGW/LBE WHERE VFR -RASN COULD OCCUR BTWN 20Z-0Z. TONIGHT ALL TERMINALS RETURN TO VFR UNDER A BKN MID DECK WHICH WILL YIELD TO SCT CI. WINDS WILL INCREASE MONDAY MORNING WITH THE APPROACH OF AN UPPER AIR SYSTEM DIVING DOWN FROM THE GREAT LAKES. GUSTS COULD EXCEED 20KTS AT FKL AND DUJ. .OUTLOOK..../18Z MONDAY THROUGH FRIDAY/... THE PASSING OF A STRONG UPPER AIR DISTURBANCE TUESDAY NIGHT INTO WEDNESDAY WILL BRING RESTRICTIONS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
439 PM EST SUN FEB 23 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 435 PM EST SUN FEB 23 2014 THE UPPER GREAT LAKES REGION IS UNDER THE INFLUENCE OF A UPPER LOW SPINNING OVER EASTERN ONTARIO AT THIS TIME. THIS UPPER LOW HAS BEEN ROTATING MID LEVEL MOISTURE SOUTHEAST ACROSS THE REGION TODAY AS SEEN IN WATER VAPOR IMAGERY AND REPRESENTED ON THE 12Z KINL SOUNDING. WITH THE OPEN WATER OVER PORTIONS OF WESTERN LAKE SUPERIOR...MOISTURE FROM THE UPPER LOW...AND RAP ANALYZED 850MB TEMPS AROUND -22C...HAVE BEEN SEEING LAKE CLOUDS AND LIGHT SNOW SHOWERS ON WEBCAMS AND SATELLITE OVER NORTHERN ONTONAGON...HOUGHTON AND KEWEENAW COUNTIES. THERE WAS ONE STRONGER BAND THAT STRETCHED FROM NORTHERN HOUGHTON COUNTY TO JUST NORTH OF GRAND MARAIS. WHERE THE RADAR CAN SAMPLE IT IT WAS INDICATING SNOWFALL RATES AROUND 0.5-1 INCH AN HOUR SOUTH EAST OF STANNARD ROCK WHERE IT HAS BEEN AIDED BY ANOTHER AREA OF OPEN WATER. AS WINDS HAVE BEEN SLOWLY SHIFTING TO THE NORTHWEST...THIS BAND HAS BEEN SHIFTING SOUTH THROUGH THE DAY...BUT DID GET A REPORT FROM WHITEFISH POINT OF AN ESTIMATED 6-8 INCHES OF SNOW. WOULD EXPECT AMOUNTS THAT HIGH IN NORTHERN LUCE COUNTY WITH THE MOVEMENT BUT THINK AMOUNTS IN THE 1-3 INCH RANGE ARE REASONABLE SINCE THIS MORNING. AS THE UPPER TROUGH AND SURFACE LOW SHIFT EAST TONIGHT...IT WILL SWEEP A WEAK SHORTWAVE AND SFC-850MB TROUGH SOUTHEAST ACROSS LAKE SUPERIOR. THESE TROUGHS WILL ACT TO PROVIDE MORE LOW LEVEL MOISTURE OVER THE REGION TONIGHT INTO MONDAY MORNING AND TURN THE LOW LEVEL WINDS TO THE NORTHWEST. 850MB TEMPS OF -23C WILL LEAD TO PLENTY OF OVER THE LAKE INSTABILITY WHERE THERE IS OPEN WATER (INVERSION HEIGHTS TO 6-7KFT). THERE IS A LITTLE BIT OF AN UNCERTAINTY ON THE ICE COVERAGE...BUT BASED OFF YESTERDAY/S MODIS IMAGE AND LOCATION OF LAKE CLOUDS TODAY...IT APPEARS THERE IS DECENT OPEN WATER FROM TWO HARBORS MINNESOTA TO ISLE ROYALE...THEN EAST-NORTHEAST OF ISLE ROYALE TO NORTHERN LAKE SUPERIOR AND ALSO TO THE EAST OF THE KEWEENAW AND TOWARDS MARQUETTE. WHERE ICE CAN BE MADE OUT...THERE HAS BEEN DECENT MOVEMENT WITH THE WEST-NORTHWEST WINDS OF 20-30KTS. WITH WEAKENING WINDS INCREASING THE RESIDENCE TIME OVER THE 20-30MI AREA OF OPEN WATER OVER THE WEST TONIGHT...THINK THAT WILL BE ENOUGH FOR LIGHT AND OCCASIONALLY MODERATE LAKE EFFECT SNOWS TO OCCUR FROM CALUMET SOUTHWEST TO IRONWOOD AND WILL CONTINUE TO SHOW LIKELY AND LOW DEFINITE POPS FOR THOSE AREAS TONIGHT. NORTH OF CALUMET IS A LITTLE UNCERTAIN ONCE WINDS TURN TO THE NORTHWEST DUE TO MORE ICE BETWEEN ISLE ROYALE AND THUNDER BAY AND SMALLER GAPS IN THE FIRST 10-15MI SOUTHEAST FROM ISLE ROYALE. THEREFORE...WILL HAVE THE POPS LOWER INTO THE LOW END LIKELY CATEGORY ONCE THE WINDS TURN TO THE NORTHWEST. OVERALL...SNOWFALL AMOUNTS SHOULD BE LIGHT AND IN THE 1-4 INCH RANGE. GUSTY THIS EVENING (TO 35MPH)...BUT WITH THE LOW WEAKENING AND SHIFTING EAST TONIGHT...SHOULD SEE A GRADUAL DIMINISHING TREND TO THE WINDS. THIS WILL LEADING TO IMPROVING VISIBILITIES FROM THE BLOWING SNOW OVER THE KEWEENAW PENINSULA. SINCE WE ARE STILL GETTING REPORTS FROM OBS/WEBCAMS/SPOTTERS OF VISIBILITIES BELOW 1/2MI AT TIMES...DECIDED TO EXTEND THE ADVISORY UNTIL MIDNIGHT. THIS WILL COVER THE EVENING TRAVEL PERIOD BEFORE THE WINDS DIMINISH OVERNIGHT. FARTHER EAST...THE MAIN AREA OF CONCERN WILL BE OVER NORTHERN LUCE AND THEN TRANSITIONING INTO ALGER COUNTY DUE TO THE FAVORABLE FETCH ACROSS THE OPEN WATER THAT LIKELY COVERS A DECENT PORTION OF LSZ265. WITH NORTHWEST WINDS AND PROBABLY SOME LAND BREEZE INFLUENCE...WOULD THINK THERE WOULD BE SOME ENHANCED LAKE EFFECT BAND AFFECTING THE COUNTY AND GRADUALLY TRANSITIONED THE BAND SOUTHWEST THIS EVENING TO AROUND AND JUST EAST OF MUNISING AREA OVERNIGHT. WITH A POTENTIAL FETCH OF 80MI AND SOME UPSTREAM MOISTENING OVER THE WESTERN LAKE...WOULDN/T BE SURPRISED IF THERE ARE SOME LOCALIZED 4 INCH AMOUNTS ESPECIALLY IF THE BAND STALLS IN AN AREA FOR A FEW HOURS. EAST OF THERE...THE AMOUNT OF ICE COVERAGE WILL LIKELY LIMIT AMOUNTS AND ONLY HAVE VALUES IN THE 1 TO MAYBE 2 INCH RANGE. WILL START TO SEE THE AFFECT OF RIDGING UPSTREAM THROUGH THE DAY TOMORROW AS THE UPPER LOW SHIFTS EAST. THIS WILL LEAD TO INCREASING 850MB TEMPERATURES (ALONG WITH SOME DRYING AND BACKING WINDS) FROM WEST TO EAST...ESPECIALLY IN THE AFTERNOON. THUS...WILL FOLLOW THAT TREND FOR POPS AND SNOWFALL AMOUNTS THROUGH THE DAY. HIGHS TOMORROW WILL BE IN THE LOW-MID TEENS OVER MUCH OF THE AREA. THIS LOOKS TO BE THE WARMEST HIGHS FOR THE REST OF THE WORK WEEK. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 435 PM EST SUN FEB 23 2014 THE CWA WILL BE DOMINATED BY LOW WIND CHILLS...AND LIGHT TO MODERATE LES FOR AREAS DOWNWIND OF W TO NW FLOW OVER GAPS IN THE CONSIDERABLE LAKE ICE COVER. MON NIGHT...THE STRONGEST 850-500 MB QVECTOR CONV AND LOWER LEVEL WAA/ISENTROPIC LIFT ASSOCIATED WITH THE FIRST IN A SERIES OF SHORTWAVE TROUGHS IS EXPECTED TO REMAIN WELL TO THE SOUTH THROUGH IA INTO SRN WI AND NRN IL. WRLY FLOW LES BANDS WILL SHIFT SLIGHTLY AS WINDS VEER TO WNW BEHIND A WEAK SFC TROUGH. WITH CONTINUED UNCERTAINTY ON THE EXTENT OF OPEN WATER AND INVERSION HEIGHTS ONLY AROUND 5K FT...MENTIONED LIKELY POPS BUT WITH FCST SNOWFALL AMOUNTS ONLY OF AROUND AN INCH OR TWO. TUE INTO TUE NIGHT...THE MODELS SUGGEST ANOTHER SHRTWV WITH AN ARCTIC FRONT BRINGING IN EVEN COLDER AIR WILL MOVE THROUGH BY LATE TUE INTO TUE NIGHT. WINDS WILL VEER TO THE NW PUSHING THE LIGHT LES OVER A GRATER PORTION OF THE ERN CWA. WITH MIN TEMPS DROPPING INTO THE -4F TO -14F RANGE...WIND CHILLS SHOULD ALSO FALL INTO THE -20 TO -30 RANGE. WED-FRI...A STRONGER SHRTWV WILL MOVE THROUGH THE NRN LAKES AS THE POLAR TROUGH MOVES INTO NRN ONTARIO. WINDS ARE EXPECTED TO VEER TO THE NW TO NNW BEHIND THIS FEATURE AS 850 MB TEMPS DROP TO AROUND -31C THU. WITH THE STRONGER NW WINDS...THE LOWEST WIND CHILLS ARE EXPECTED THU MORNING INTO THE -25 TO -35 RANGE EVEN THOUGH THERE MAY SOME MODIFICATION OVER THE MOSTLY FROZEN LAKE. WITH LIGHTER WINDS AND FEW CLOUDS BY FRI AS THE ARCTIC HIGH SETTLES OVER THE AREA...TEMPS SHOULD DROP AT LEAST INTO THE -15 TO -25 RANGE OVER MUCH OF THE CWA...WITH SOME -30S EVEN POSSIBLE FOR TRADITIONAL COLD SPOTS. SAT-SUN...THERE IS GREATER UNCERTAINTY WITH ANY INDIVIDUAL SHRTWVS BUT WITH THE POLAR TROUGH LINGERING NEAR JAMES BAY...ANOTHER BOUT OF LOWER 850 MB TEMPS AND HIGHER WINDS MAY MOVE IN BY SAT WITH DIMINISHING WINDS AND CONTINUED COLD ON SUN WITH THE ARCTIC RIDGE DOMINATING THE NRN LAKES. BY THE WEEKEND...THE ICE COVER IS LIKELY TO SOLIDIFY...REDUCING LES CHANCES/AMOUNTS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1248 PM EST SUN FEB 23 2014 COLD AIR AND INCREASING MOISTURE ROTATING AROUND A LOW PRESSURE SYSTEM NEAR HUDSON BAY WILL LEAD TO CONTINUED GUSTY WESTERLY WINDS THIS AFTERNOON. WITH SOME OPEN WATER OVER WESTERN LAKE SUPERIOR...LAKE EFFECT SNOW SHOWERS HAVE BEEN OCCURRING IN THE WEST WIND SNOW BELTS AND LARGELY AFFECTING KCMX FOR MUCH OF THIS AFTERNOON. BUT AS A WEAK TROUGH MOVES THROUGH LATE THIS AFTERNOON AND DURING THE EVENING...EXPECT WINDS TO TURN MORE FAVORABLE FOR LAKE EFFECT AT KIWD AND HAVE LOWER VISIBILITIES. BUT THIS TURN IN THE WINDS COULD INFLUENCE KCMX SNOWFALL...AS THERE WILL BE MORE OF AN ICE SHADOW DUE TO THE INCREASED ICE NEAR ISLE ROYALE. MAINLY IMPROVED VISIBILITIES DUE TO THE WEAKENING WINDS AND IF ICE COVERAGE IS LESS THAN EXPECTED...VISIBILITIES MAY BE LOWER THAN EXPECTED. AN APPROACHING HIGH PRESSURE RIDGE ON MONDAY AFTERNOON MAY LEAD TO AN IMPROVEMENT IN CONDITIONS AT KIWD/KCMX LATE IN THE TAF PERIOD. AT KSAW...WEST TO NORTHWEST FLOW ISN/T TOO FAVORABLE FOR LESS THAN VFR CONDITIONS FROM LAKE EFFECT BUT WITH THE EXPECTED INCREASE IN MOISTURE WITH THE TROUGH DID LOWER TO MVFR CEILINGS AS THE TROUGH MOVES THROUGH. HAVE A FEELING THE DOWNSLOPING FLOW WILL LEAD TO VALUES RIGHT ON THE EDGE OF VFR/MVFR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 435 PM EST SUN FEB 23 2014 THE WEAKENING LOW NEAR HUDSON BAY WILL COMBINE WITH A HIGH PRESSURE RIDGE MOVING THROUGH THE NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO LEAD TO GRADUALLY DECREASING WEST TO NORTHWEST WINDS OVER LAKE SUPERIOR TONIGHT THROUGH MONDAY NIGHT. HAVE BEEN SEEING THE GALES PERSISTING OVER THE EASTERN PART OF LAKE SUPERIOR ON THE STANNARD ROCK AND GRANITE ISLAND OBS THIS AFTERNOON...BUT WITH UPSTREAM OBS GENERALLY IN THE 30KT RANGE...WOULD EXPECT THE EASTERN SITES TO COME DOWN SHORTLY. THUS...WILL ALLOW THE GALE WARNING OVER THE EASTERN LAKE TO EXPIRE AT 00Z AND HAVE ALREADY CANCELLED THE WESTERN LAKE. EVEN WITH THIS DIMINISHMENT...THERE WILL LIKELY BE ENOUGH OF A GRADIENT TO KEEP WINDS IN THE 15 TO 30KT RANGE FOR MUCH OF THE FORECAST PERIOD. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ001- 003. LAKE SUPERIOR... GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...JLB AVIATION...SRF MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1129 AM CST SUN FEB 23 2014 .UPDATE...CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TODAY FOR MAINLY THE SE CWA. WILL LEAVE THE FLASH FLOOD WATCH IN EFFECT FOR THE EXTREME SE CWA AS LATEST HIRES MODELS INDICATE A QUICK INCH OF RAIN COULD BE POSSIBLE. TEMPERATURES LATE THIS AM WERE MAINLY IN THE UPPER 50S TO AROUND 60. HIGH TEMPS THIS AFTERNOON WILL BE PLEASANT...MAINLY IN THE LOWER 70S. THE ONLY CHANGES TO THE CURRENT FORECAST WERE TO CUT POPS SOME FOR TODAY ACROSS THE CENTRAL AND PORTIONS OF THE SOUTHERN CWA...AND TO ADJUST THE HOURLY TEMPS TO ACCOUNT FOR THE LATEST TRENDS. /27/ && .AVIATION...MVFR CIG WL LIKELY IMPACT AREAS ALONG/S OF I-20 THIS MORNING BEFORE VFR CIG TRY AND RETURN AFTER 15Z OR SO. ONLY EXCEPTION MAY VERY WELL BE NEAR HBG/PIB WHERE PERSISTENT SHRA/TSRA BRING AT LEAST INTERMITTENT MVFR/IFR CIG AND VSBY THRU MOST OF THE DAYLIGHT HRS. THE HEAVY RAINS NEAR HBG/PIB WL COME TO AN END BY EARLY EVENING AS THIS ACTIVITY PUSHES E. A COLD FRONT WL START CROSSING THE ARKLAMISS FROM THE N AROUND 22Z PASSING THRU THE PIB/HBG AREA AROUND 06-08Z TONIGHT. NLY WINDS WL BECOME A BIT GUSTY IN WAKE OF THE FRONT...BUT LIGHTER WINDS WL RETURN DURING THE DAY MON. /BK/15/ && .PREV DISCUSSION... /ISSUED 400 AM CST SUN FEB 23 2014/ SHORT TERM...TODAY THROUGH MONDAY NIGHT...LOW LEVEL WARM/MOIST ADVECTION IS UNDERWAY ALONG THE GULF COAST THIS MORNING EVIDENT BY INCREASING COVERAGE OF SHOWER AND THUNDERSTORM ACTIVITY ACROSS EASTERN LA/SOUTHERN MS. FURTHER NORTH...AN ADVANCING COLD FRONT IS ANALYZED ON THE NORTHERN FRINGES OF THE TN VALLEY WHICH IS PROGGED TO CROSS THE ARKLAMISS STARTING LATE THIS AFTERNOON. PRIMARY CONCERN FOR TODAY IS THE RISK FOR HEAVY RAINS ALONG THE HWY 98 CORRIDOR...AND THUNDERSTORMS THAT COULD PRODUCE SOME NICKEL TO QUARTER SIZE HAIL ALONG AND SOUTH OF HWY 84. 00Z NMM/ARW/LOCAL WRF OUTPUT SHOW THE AFOREMENTIONED SHOWER/THUNDER ACTIVITY EXPANDING INTO SOUTHERN ZONES BY MID MORNING AND GRADUALLY COMING TO AN END BY LATE AFTERNOON/EARLY EVENING. THE GUIDANCE HAS BEEN CONSISTENT SHOWING MID LEVEL LAPSE RATES CLIMBING INTO THE 6.5-7.5C/KM RANGE SOUTH OF I-20 AS THE LOW LEVEL WARM AIR SURGES IN...WITH SHOWALTER INDICES IN THE -2 TO -4C RANGE INDICATIVE OF ELEVATED CONVECTION POTENTIAL GIVEN RELATIVELY COOL PBL PER BUFR SOUNDINGS. WHILE LOW LEVEL WINDS LOOK TO VEER WESTERLY BY DAYBREAK...A PASSING MID/UPPER LEVEL JET STREAK JUST TO OUR NORTH WILL PROVIDE NEEDED ASCENT FOR CONVECTION AS THE RIGHT ENTRANCE REGION OF THIS FEATURE PASSES. A FEW DEEPER THUNDERSTORM CORES SEEM REASONABLE GIVEN THE SYNOPTIC SETUP AND WILL KEEP THE MENTION OF SOME QUARTER SIZE HAIL IN THE HWO FOR TODAY. OF EQUAL (IF NOT GREATER) CONCERN IS THE POTENTIAL FOR SOME LOCALLY HIGH RAINFALL TOTALS ALONG HWY 98 COME LATE AFTERNOON. LOCAL WRF OUTPUT SHOWS A SWATH OF 3-5 INCHES ACROSS MARION/LAMAR/FORREST COUNTIES BETWEEN 12Z AND 22Z...WHILE THE HI-RES NMM/ARW SHOW SIMILARLY ALARMING TOTALS OF ANYWHERE FROM 2-4 INCHES DURING THE SAME TIME. GIVEN PW VALUES CLIMBING NEAR/JUST ABOVE 1.5 IN ACROSS THIS AREA BY MID DAY (RIGHT AT THE 99TH PERCENTILE FOR FEB) AND THE CONVECTIVE NATURE OF THE ACTIVITY THESE KINDS OF TOTALS SEEM QUITE REASONABLE. THE BIGGEST QUESTION MARK IS JUST WHERE IS THE HEAVIEST AXIS GOING TO SET UP. THE HRRR HAS BEEN TOYING WITH THE BEST AXIS REMAINING CLOSER TO THE COAST ON A FEW RUNS...BUT SHOWS 2-3 IN ALONG/SOUTH OF HWY 98 ON OTHERS. GIVEN THE HEAVY RAINS WE SAW ACROSS THIS AREA A COUPLE DAYS AGO AND THE COINCIDENT HEAVY RAIN AXIS SHOWN IN THE HI-RES ARW/NMM/LOCAL WRF FEEL THE RISK FOR FLASH FLOODING IS GREAT ENOUGH TO WARRANT A FLASH FLOOD WATCH THROUGH 22Z. BY EARLY EVENING THE BETTER FORCING WILL SHIFT EAST WHICH WILL SHUNT DEEPER CONVECTION AND ASSOCIATED HEAVY RAIN RISK EAST AS WELL. OTHER THAN SOME LIGHT SHOWER ACTIVITY SOUTH OF I-20 THE OVERNIGHT HOURS LOOK PRETTY QUIET AS THE COLD FRONT CROSSES THE REGION. QUIET CONDITIONS LOOK TO PREVAIL THROUGH MONDAY NIGHT...ALTHOUGH IT`S NOT COMPLETELY OUT OF THE QUESTION THAT A FEW LIGHT SHOWERS COULD DEVELOP ACROSS THE DELTA EARLY TUE MORNING AS A JET STREAK IN THE PERSISTENT WESTERLY FLOW ALOFT NOSES IN. AS FOR TEMPS/POPS...LOWERED MAV GUIDANCE FOR THIS AFTERNOON ACROSS SOUTHEASTERN AREAS GIVEN THE HIGH CHANCES FOR RAIN/CLOUDS THROUGH THE DAY. ALSO RAISED OVERNIGHT LOWS FOR TUE MORNING TOWARD THE WARMER NAM/ECMWF MOS NUMBERS AND RAW GFS OUTPUT. POPS FOR TODAY WERE RAISED QUITE A BIT NEAR HBG. /BK/ LONG TERM...TUESDAY THROUGH SUNDAY...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR THE WORK WEEK WITH NEAR NORMAL TEMPERATURES RETURNING FOR THE WEEKEND. RAIN WILL SPREAD ACROSS THE CWA TUESDAY ASSOCIATED WITH A SFC LOW OVER THE SOUTHERN PLAINS AND A COLD FRONT DROPPING THROUGH THE REGION. THE ECMWF CONTINUES TO GENERATE MORE RAINFALL THAN MODEL CONSENSUS WOULD SUGGEST OVER THE SOUTHERN PORTION OF OUR CWA WHERE MORE THAN AN INCH TOTAL COULD FALL BY WEDNESDAY MORNING. THE ARCTIC AIR WILL BE FILTERING INTO OUR CWA TUESDAY NIGHT AS THE RAIN ENDS FROM THE NORTHWEST. THE LIGHT RAIN LOOKS TO MIX WITH OR BRIEFLY CHANGE OVER TO LIGHT SNOW BEFORE ENDING EARLY WEDNESDAY MORNING ALONG THE HIGHWAY 82 CORRIDOR. TEMPERATURES WILL REMAIN ABOVE FREEZING AND BOTTOM OUT IN THE MID 30S ALONG THE HIGHWAY 82 CORRIDOR SO NO ACCUMULATION ON ROADWAYS IS CURRENTLY ANTICIPATED. NO SIGNIFICANT PRECIPITATION IS EXPECTED AFTER SUNRISE WEDNESDAY. THE STRONG CAA WILL HOLD HIGH TEMPERATURES IN THE 40S ACROSS MUCH OF THE NORTHERN HALF OF THE AREA. THE ASSOCIATED SURFACE HIGH WILL BECOME CENTERED OVER OUR CWA WEDNESDAY NIGHT AND THEN SHIFT EAST OF OUR CWA THURSDAY AFTERNOON. THIS WILL SET UP THE COLDEST MORNING OF THE FORECAST PERIOD THURSDAY MORNING WHERE LOWER 20S WILL BE COMMON IN THE NORTH TO AROUND 30 DEGREES IN THE SOUTH. DRY WEATHER WILL CONTINUE THURSDAY BUT A DISTURBANCE WILL DROP OVER THE SOUTHERN PLAINS THURSDAY NIGHT AND HELP DEVELOP A SURFACE LOW. WAA AHEAD OF THIS SYSTEM WILL BRING RAIN BACK INTO OUR WESTERN ZONES THURSDAY NIGHT. THE ECMWF IS FASTER THAN THE GFS AND ENSEMBLES BUT CONSENSUS BRINGS THE SHORTWAVE AND SFC LOW OVER OUR WESTERN ZONES BY FRIDAY EVENING AND SHIFT THE SYSTEM EAST OF OUR CWA SATURDAY. DRY WEATHER LOOKS TO RETURN SATURDAY AND LAST THROUGH MUCH OF SUNDAY. ANOTHER DISTURBANCE WILL DROP OVER THE SOUTHERN PLAINS SUNDAY AND INCREASE OUR RAIN CHANCES AGAIN SUNDAY NIGHT. /22/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 73 46 60 48 / 13 13 0 5 MERIDIAN 74 47 63 46 / 20 13 0 6 VICKSBURG 73 44 58 47 / 13 11 0 5 HATTIESBURG 70 55 67 50 / 89 16 0 9 NATCHEZ 70 49 59 49 / 20 17 0 7 GREENVILLE 69 36 55 42 / 7 7 0 7 GREENWOOD 74 38 55 43 / 8 8 0 4 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR MSZ072>074. LA...NONE. AR...NONE. && $$
AREA FORECAST DISCUSSION
NWS BILLINGS MT
228 PM MST SUN FEB 23 2014 .SHORT TERM...VALID FOR MON AND TUE... ONLY MINOR CHANGES IN THE SHORT TERM FORECAST AS THE WINTER STORM FOR THE AREA REMAINS RIGHT ON TRACK. SO FAR THIS AFTERNOON...THE STORM IS EVOLVING AS EXPECTED. THE OVERRUNNING PATTERN SETUP EARLY THIS MORNING AS HAS BEEN RESULTING IN STEADY LIGHT SNOW FOR CENTRAL AND WESTERN ZONES...WHERE A COUPLE INCHES OF SNOW HAS FALLEN ALREADY TODAY. THE MORE DYNAMIC AND MOISTURE RICH PORTION OF THE STORM WILL MOVE INTO THE AREA THIS EVENING AND CONTINUE OVERNIGHT TONIGHT. THE DYNAMIC WAVE THAT WILL LEAD TO THIS ENHANCED SNOWFALL OVERNIGHT IS CURRENTLY SEEN ON WV IMAGERY OVER SOUTHERN BRITISH COLUMBIA. THE MOISTURE RICH PACIFIC AIR AHEAD OF THE WAVE CAN NOW BE SEEN ON WV IMAGERY OVER IDAHO AND JUST STARTING TO PUSH INTO FAR WESTERN MONTANA. SNOW RATES WILL INCREASE AS THIS MOISTURE AND ENHANCED SYNOPTIC LIFT SLIDE INTO THE AREA LATE THIS AFTERNOON / EARLY THIS EVENING. OVERNIGHT...THE WAVE WILL SLIDE SOUTH AND EAST TOWARD THE FORECAST AREA...PRODUCING STRONG QG FORCING OVER THE AREA THROUGH MONDAY MORNING. BY LATE MONDAY MORNING / EARLY MONDAY AFTERNOON...THE WAVE WILL PUSH EAST INTO THE DAKOTAS AND SNOW RATES WILL BECOME SIMILAR TO THOSE WE HAVE SEEN TODAY AS THE ONLY REMAINING FORCING MECHANISM WILL BE THE ISENTROPIC ASSENT OVER THE COLD AIR. SINCE THE FORECAST IS PLAYING OUT AS EXPECTED SO FAR AND MODELS REMAIN CONSISTENT WITH QPF AMOUNTS...HAVE NOT MADE ANY SIGNIFICANT ADJUSTMENTS TO QPF / SNOW AMOUNTS WITH THIS FORECAST UPDATE. TEMPERATURES WILL REMAIN FAIRLY STEADY THROUGH THE AFTERNOON TODAY AND DROP SLIGHTLY FOR THE DAY TOMORROW AS SLIGHTLY COLDER 850 MB TEMPERATURES SLIDE INTO THE AREA BEHIND THE PASSING WAVE. THUS HIGH TEMPERATURES IN THE SINGLE DIGITS TO AROUND TEN ARE EXPECTED TOMORROW. LOWS OVERNIGHT TONIGHT WONT DROP SIGNIFICANTLY AS CLOUD COVER WITH THE CONTINUOUS PRECIPITATION WILL PREVENT ANY RADIATIONAL COOLING. THE SECONDARY WAVE THAT MOVES INTO THE AREA MONDAY NIGHT / TUESDAY MORNING REMAINS ON TRACK. HOWEVER...MODELS ARE HINTING AT SLIGHTLY BETTER MOISTURE AVAILABILITY ALONG THE FOOTHILLS AND MOUNTAINS THAN PREVIOUSLY EXPECTED. THUS HAVE FURTHER INCREASED POPS...MAINLY SOUTH OF BILLINGS ALONG THE FOOTHILLS. HAVE ALSO INCREASE SNOW AMOUNTS TO SHOW A FEW ADDITIONAL INCHES OF ACCUMULATION POSSIBLE THROUGH EARLY TUESDAY MORNING. ONCE THE SHORTWAVE RAPIDLY DEPARTS THE AREA TUESDAY AFTERNOON...THE AREA WILL FINALLY DRY OUT AND ALL PRECIPITATION CHANCES WILL END. THE OTHER EFFECT THE SHORTWAVE WILL HAVE IS TO BRING A REINFORCING SHOT OF COLD AIR INTO THE AREA THROUGH THE DAY TUESDAY...WHICH WILL KEEP OUT HIGH TEMPERATURES FROM GETTING OUT THE TEENS IN MOST LOCATIONS. ALSO FOR LOCATIONS TOWARD MILES CITY AND BAKER...CLOUD COVER WILL ALREADY BE DECREASING BY TUESDAY MORNING...THUS TUESDAY MORNING COULD SEE THE COLDEST OVERNIGHT LOW TEMPERATURES. CHURCH .LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN... MAIN MESSAGE FOR THE EXTENDED FORECAST IS STILL FOCUSED ON THE HUDSON BAY LOW AND A RIDGE OF HIGH PRESSURE ANCHORED ALONG THE WEST COAST THROUGH THE ENTIRE WEEK. THIS PATTERN WILL ALLOW ARCTIC AIR TO PUSH SOUTH OUT OF CANADA ALONG WITH SHORT WAVE ENERGY TO MOVE ACROSS OUR AREA WITH NORTHERLY FLOW ALOFT. THE ONLY BREAK IN THE COLD WEATHER WILL BE ON WEDNESDAY AS BOTH GFS AND ECMWF BRING 850 MB TEMPERATURES OF 0C TO +2C INTO THE AREA. GUIDANCE IS GOING WITH UPPER 30S TO LOWER 40S ON WEDNESDAY BUT BELIEVE SNOW COVER WILL BE SUFFICIENT ENOUGH TO LIMIT MUCH HEATING AND HAVE CONTINUED HIGH TEMPERATURES IN THE LOWER 30S. HAVE GONE MAINLY WITH THE ECMWF MODEL FOR THURSDAY AS IT PUSHES AN ARCTIC COLD FRONT THROUGH OUR AREA DURING THE MORNING HOURS. GFS IS ABOUT 6 HOURS BEHIND THE EC AND GIVEN THE DEPTH OF THE COLD AIR...BELIEVE EC HAS A BETTER HANDLE ON THE TIMING OF THE FRONT. ANOTHER SURGE OF ARCTIC AIR WILL MOVE INTO THE AREA OVER THE WEEKEND WHICH WILL KEEP OUR TEMPERATURES WELL BELOW NORMAL FOR THIS TIME OF THE YEAR. STRONG BAROCLINIC ZONE/FRONTOGENESIS AND UPSLOPE FLOW DEVELOPING WITH EACH SURGE OF ARCTIC AIR AND THIS FORCING WILL PRODUCE PERIODS OF SNOW. THE BEST AREAS OF ACCUMULATING SNOWFALL WILL BE OVER OUR WESTERN AND CENTRAL ZONES. AFTERNOON TEMPERATURES FRIDAY AND SATURDAY WILL ONLY BE IN THE TEENS WEST TO SINGLE DIGITS EAST. SATURDAY NIGHT LOOKS TO BE THE COLDEST WITH READINGS AT ALL LOCATIONS BELOW ZERO. RICHMOND && .AVIATION... IFR TO VLIFR WILL BE WIDESPREAD TONIGHT THROUGH MONDAY AS HEAVY SNOWFALL IS EXPECTED AT ALL FLIGHT TERMINALS. HEAVY SNOW WILL BRING MOUNTAIN OBSCURATIONS. THE SNOW WILL BEGIN TO TAPER OFF BY MONDAY AFTERNOON. RICHMOND && .PRELIMINARY POINT TEMP/POPS... MON TUE WED THU FRI SAT SUN ----------------------------------------------------------- BIL 002/009 905/014 003/032 015/022 009/013 903/007 906/011 +9/S 62/S 00/U 26/S 64/S 44/S 43/S LVM 002/011 902/020 005/037 017/034 013/018 003/012 903/017 ++/S 85/S 00/U 26/S 64/S 45/S 44/S HDN 003/008 906/013 903/032 009/021 007/012 906/008 909/013 +9/S 62/S 00/U 16/S 64/S 44/S 43/S MLS 901/006 906/009 902/027 004/017 002/008 909/003 910/007 +8/S 10/B 00/U 12/S 23/S 34/S 43/S 4BQ 003/008 905/010 902/032 007/022 005/011 905/007 907/011 +9/S 21/B 00/U 12/S 23/S 34/S 43/S BHK 906/001 910/005 905/026 902/016 902/006 913/003 913/008 +9/S 10/B 00/U 01/B 12/S 33/S 43/S SHR 006/010 906/015 001/034 014/029 010/015 000/014 903/020 ++/S 75/S 00/U 13/S 43/S 34/S 43/S && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST TUESDAY FOR ZONES 28>31-34>36-38>42-56>58-63>68. WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MST TUESDAY FOR ZONES 32-33-37. WY...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST TUESDAY FOR ZONES 98-99. && $$ WEATHER.GOV/BILLINGS
Area Forecast Discussion...UPDATED National Weather Service Missoula MT 1115 AM MST Sun Feb 23 2014 .UPDATE...Allowed the winter weather advisory for Lemhi County to expire. && .DISCUSSION...Web cams across Lemhi County have shown improvement this morning with some blue skies down by Gimore Summit. There will continue to be some light snow there in the next 24 hours, but light accumulations are expected. Water vapor imagery is indicating that Pacific moisture is pushing in over Washington and Oregon State. This is an encouraging sign for the arrival of the precipitation by this afternoon. Also the trend of the last several runs of the high resolution HRRR model is showing an increase in coverage of snow across Clearwater County and northeastern Idaho County, and west-central Montana by mid- afternoon. This matches the moderately strong warming aloft, the aforementioned moisture influx and strengthening of the upper level jet to provide ample lift. This is giving us good confidence for snowfall rates to increase, potentially to 1+ inch per hour at times in all the areas that have a winter storm warning out. There is also indication that there will be a 2nd push of arctic air late this evening which would strengthen the gap winds through places like Helmville, Highway 200, I-90, Hellgate Canyon which would create white-out and very difficult driving conditions at times. && .AVIATION...A significant winter storm will be moving in today causing widespread mountain obscuration, low ceilings/visibility across north central Idaho and western Montana. The light snow this morning is expected to slowly increase in intensity by mid morning. For this afternoon, the snow could become quite heavy at times especially at KMSO and KBTM with the heaviest snow expected between 23/2000z and 24/0600z. KSMN is expected to see mainly light snow with short periods of moderate snow during the morning hours. The light to moderate snow will be tapering off in the afternoon. KGPI will see light snow showers develop around 23/1500z which will combine with gusty northeast winds to cause mainly impacts to visibility. Gusty northeast to east winds are expected to develop across most of western Montana by this afternoon further impacting visibility. && .PREV DISCUSSION... /ISSUED 443 AM MST Sun Feb 23 2014/ ..HEAVY SNOW...HAZARDOUS TRAVEL CONDITIONS TODAY THROUGH MONDAY... DISCUSSION... The first part of a significant winter storm has arrived over the Northern Rockies this morning. Light snow will be present through much of this morning, with minor accumulations throughout the region. Be aware, this snow event will only be getting warmed up this morning. Area roads will begin to deteriorate, with snow and ice cover creating hazardous travel conditions. However, travel conditions will only get worse through the day. THE MAIN SNOW EVENT... Beginning this afternoon, snow rates across west central Montana and north central Idaho will quickly increase. Snowfall rates of 1 to 2 inches per hour will be common at both low and high elevations. The epicenter of the heavy snow remains the Interstate 90 corridor through much of western Montana and Highway 93 northward and southward from Missoula. Snowfall will eventually become unmanageable by road crews this afternoon, with possible crippling winter travel conditions developing. Periods of heavy snow, blowing snow (winds gusting to 40 mph in open areas and within east-west canyons), low visibility, slick roads, disabled vehicles in deep snow, and very cold windchill (negative 10 to negative 20 degrees) will all be present, increasing local travel misery. If you must travel late this afternoon through midday Monday, consider traveling with items necessary for winter survival in the event of becoming stuck in the snow. Snow will slowly diminish throughout Monday, leaving a cold airmass along the Continental Divide and across northwest Montana. Travel will likely remain challenging through Monday as well, as road crews continue to work on clearing travel routes. Tuesday through Thursday... Residual moisture will be lingering around western Montana and north central Idaho and will slowly start to dry out late Tuesday as the high pressure builds in from the west. Clear skies, light winds and fresh snowfall will help the temperatures plummet Tue night setting up a very cold Wednesday morning. By Thursday, another pacific system will be moving bringing another round of precipitation. Long range models continue to hint at another arctic push by the end of this week. This arctic push could potentially be stronger than the current one so stay tuned! && .MSO WATCHES/WARNINGS/ADVISORIES... MT...WINTER STORM WARNING until 11 AM MST Monday Butte/Blackfoot Region...Potomac/Seeley Lake Region. WINTER STORM WARNING until 11 AM MST Monday Bitterroot/Sapphire Mountains...Lower Clark Fork Region. WINTER STORM WARNING until 11 AM MST Monday Missoula/Bitterroot Valleys. WINTER STORM WARNING until 11 AM MST Monday Flathead/Mission Valleys. WINTER WEATHER ADVISORY until 5 AM MST Monday Kootenai/Cabinet Region...West Glacier Region. ID...WINTER STORM WARNING until 10 AM PST Monday Northern Clearwater Mountains...Southern Clearwater Mountains. WINTER WEATHER ADVISORY until 10 AM PST Monday Lower Hells Canyon/Salmon River Region...Orofino/Grangeville Region. && $$ Follow us on Facebook and Twitter! https://www.facebook.com/US.NationalWeatherService.Missoula.gov https://www.twitter.com/NWSMissoula
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1153 AM CST SUN FEB 23 2014 .UPDATE... ISSUED AT 625 AM CST SUN FEB 23 2014 JUST GOT A REPORT OF 6 INCHES SNOWFALL IN OGALLALA. ADDITIONAL SNOWFALL THIS MORNING WOULD LIKELY PUT THAT COUNTY IN THE 6 INCHES IN 12 HOUR CRITERIA. AN ADDITIONAL 2 INCHES WOULD PUT THEM IN THE 8 INCHES IN 24 HOUR CRITERIA. A WARNING HAS BEEN ISSUED FOR THAT COUNTY. UPDATE ISSUED AT 538 AM CST SUN FEB 23 2014 THE METAR AT KOGA IS SHOWING 1 MILE VSBY WITH MODERATE SNOW. THE NEDOR CAMS IN DEUEL COUNTY SHOW SIGNIFICANT ON THE GROUND AND STILL FALLING AS THE SECOND DISTURBANCE OPERATES ON THE CHEYENNE DIVIDE THIS MORNING. GIVEN THE 8 PM 5 INCH SNOWFALL REPORT FROM THE COOP OBSERVER AT BIG SPRINGS...WINTER STORM CONDITIONS ARE LIKELY UNDERWAY IN DEUEL COUNTY. SO A WINTER STORM WARNING HAS BEEN ISSUED FOR THAT COUNTY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 353 AM CST SUN FEB 23 2014 ROAD SURFACES IN MANY AREAS CROSSED THE FREEZING MARK OVERNIGHT AND THE SNOW MELTED AN REFROZE PRODUCING HAZARDOUS TRAVEL SO THE WINTER WEATHER ADVISORY CONTINUES THIS MORNING. AS ADVERTISED BY THE HIGH RESOLUTION MODELS...THE NAM...ARF...NMM AND SREF...A COUPLED JET DEVELOPED ACROSS THE FORECAST AREA. THE HEAVY SNOW WAS LOCALIZED ACROSS CHASE AND HAYES COUNTIES AND PERHAPS A FEW OTHER AREAS. THE MODELS IN GENERAL SHOWED FAIR SKILL FORECASTING THIS BUT NEAR ZERO SKILL IN LOCATION. 50 MILES OF FORECAST ERROR WITH THE LOCATION. THE NAM BOUNCED AROUND FAVORING CNTL LINCOLN COUNTY...THEN SRN LINCOLN COUNTY AND THEN KEITH COUNTY. MODEL SKILL IN PREDICTING THE LOCATION OF MESOSCALE HEAVY SNOW BANDS WAS POOR. THE WINTER STORM WARNING FOR CHASE AND HAYES COUNTIES CONTINUES THIS MORNING. THE RADAR OUT OF KGLD CONTINUES TO SHOW LIGHT TO MODERATE SNOW AS THIS FORMERLY HEAVY BAND OF SNOW IS WEAKENING. THE LATEST RADAR OUT OF KCYS IN CONJUNCTION WITH THE RAP AND NAM MODELS SUGGESTS A SECOND BAND OF LIGHT TO MODERATE SNOW WILL MOVE INTO WRN NEBRASKA THIS MORNING AND THEN LIFT SLOWLY NORTH AS A DEVELOPING WARM FRONT THIS AFTERNOON AND TONIGHT. BARRING THE DEVELOPMENT OF AN ORGANIZED HEAVY SNOW BAND...IT IS BELIEVED SNOWFALL AMOUNTS TODAY WILL BE AN INCH OR LESS USING A 13 TO 1 RATIO WHICH HAS BEEN THE PREVAILING MARKER OUTSIDE OF THE HEAVY SNOW BAND WHICH DEVELOPED ACROSS FAR SOUTHERN NEBRASKA LAST NIGHT. THUS FAR...KLBF MEASURED 0.19 INCHES OF LIQUID WITH ABOUT 2 INCHES OF SNOWFALL. AN ADDITIONAL 0.08 IS FORECAST TODAY FOR A TOTAL OF 0.27 INCHES. YESTERDAYS MODEL MEDIAN QPF WHICH WAS USED FOR THE FORECAST WAS 0.28. THUS THE ACCURACY OF THE SNOWFALL FORECAST HINGES ON THE SNOW TO WATER RATIO WHICH IS HIGHLY DEPENDENT ON DEEP LIFT TO PRODUCE HIGH RATIOS. THE COBB METHODOLOGY CONTINUES TO ADVERTISE VERY HIGH RATIOS OF 17 TO 20 TO 1 TODAY AND TONIGHT. THESE RATIOS ARE SUSPECT AND LIKELY BIASED TOWARD THE DEVELOPMENT OF DEEP VERTICAL LIFT SO 13 TO 1 WAS USED TODAY. THE HIGH COBB RATIOS WERE USED TONIGHT...NEAR 20 TO 1 AT KVTN...BUT HPC HAS OUTLOOKED THIS AREA FOR SLIGHT RISK OF 4 INCHES OF ACCUMULATION. THE MEDIAN QPF AT KVTN IS ABOUT 0.15 INCHES AND THE FORECAST IS FOR 0.15. THE 20 TO 1 RATIO THEN PRODUCES 3 INCHES OF SNOW FOR VALENTINE. THE NAM SUGGESTS GENERALLY MODERATE LIFT AND MID LEVEL FRONTOGENESIS TONIGHT ACROSS THE NORTH...NO WHERE NEAR THE STRENGTH EXHIBITED BY THE COUPLED JET STRUCTURE SATURDAY NIGHT ACROSS THE SOUTH BUT THERE IS POTENTIAL FOR A PERIOD OF MODERATE SNOW AS THERE IS BANDING POTENTIAL. GIVEN THE UNCERTAINTIES OF FCSTING BANDED SNOW...A MIDDLE OF THE ROAD FORECAST IS IN PLACE FOR THE NORTH TONIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 353 AM CST SUN FEB 23 2014 MONDAY MORNING WILL CONTINUE TO SEE SNOW ACROSS THE NORTHERN PART OF THE CWA AS THE NEXT WAVE CONTINUES TO PUSH ACROSS S DAKOTA AND NORTHEAST NEB. MODELS ARE IN FAIR AGREEMENT WITH THE BAND OF SNOW TO LINGER THROUGH MONDAY MORNING THEN DIMINISHES FOR THE AFTERNOON. HIGHEST AMOUNTS OF ADDITIONAL SNOW LIKELY AROUND AN INCH IN THE MORNING BEFORE BECOMING LIGHT AND PUSHING EAST. HOWEVER YET ANOTHER DISTURBANCE IS FORECAST TO TRACK ACROSS THE HIGH PLAINS FOR LATE MONDAY INTO TUESDAY. COLD ARCTIC HIGH PRESSURE WILL BEGIN TO PUSH ACROSS SOUTHERN CANADA BY MONDAY EVENING. THIS WILL BRING IN SOME DRIER AIR ACROSS THE NORTHERN PLAINS WITH THE MAIN SNOW BANDING EXPECTED ACROSS THE SOUTHWESTERN PART OF THE CWA. DEPTH OF THE DENDRITIC GROWTH ZONE IS FAIRLY DEEP...HOWEVER THE BEST OMEGA IS ACROSS THE HIGHER TERRAIN TO THE WEST. WILL HAVE TO OVER COME A SOMEWHAT DRY LOWER LEVEL WITH TOP DOWN SATURATION...ALTHOUGH SHOULD RESULT IN AROUND AN INCH OR TWO OF SNOW. IF A BAND OF SNOW BECOMES MORE STATIONARY...WHICH IS NOT SUGGESTED AT THIS TIME BY THE MODELS...BUT AFTER SEE LAST NIGHTS BAND CAN NOT BE RULED OUT...ANOTHER ADVISORY FOR 2 TO 4 INCHES WOULD BE WARRANTED. THE COLD HIGH PRESSURE WILL BEGIN TO BE NOTICES WITH TEMPS FALLING TO NEAR ZERO FOR TUESDAY MORNING. TUESDAY AFTERNOON AS THE SNOW DIMINISHES FROM THE NORTH...CLOUDS WILL BE ON THE DECREASE. COLD ARCTIC AIR WILL SPREAD ACROSS THE AREA WITH HIGHS STRUGGLING INTO THE 20S. BY TUESDAY NIGHT THE DISTURBANCE WILL BE SE AND CLEARING SKIES ASSOCIATED WITH THE SFC HIGH WILL COMBINE WITH THE SNOW PACK TO PRODUCE A VERY COLD LATE FEBRUARY NIGHT. WIDESPREAD SINGLE DIGITS...AND MOST NOT TO FAR FROM ZERO. LOCALLY BELOW ZERO STILL POSSIBLE...HOWEVER CENTER OF THE HIGH IS OVER HEAD CLOSER TO MIDNIGHT SO TEMPS MIGHT BEGIN TO CLIMB OR AT LEAST HOLD STEADY FOR THE EARLY MORNING HOURS. SW WINDS DEVELOP FOR WED...ON THE BACK SIDE OF THE HIGH...WITH WARMER AIR TO PUSH ACROSS THE AREA. HIGHS WARM INTO THE 30S...HOWEVER SNOW PACK COULD PLAY A ROLL IN TEMPS BELOW GUIDANCE. REST OF THE WORK WEEK WILL CONTINUES TO SEE A RIDGE ACROSS THE SOUTHERN ROCKIES WHICH TRAILS TO THE NW INTO THE PAC NORTHWEST. THIS FAVORS A NORTHWEST FLOW AND PROGRESSIVE CLIPPER SYSTEM AND ON AND OFF CLOUDS AND MAYBE SOME LIGHT SNOW. BY THE WEEKEND BOTH THE GFS AND THE EC ARE CARVING A TROUGH ACROSS THE WESTERN CONUS WITH MORE ZONAL FLOW EAST OF THE ROCKIES. WILL CONTINUE TO MONITOR THIS SYSTEM WHICH MODELS EJECT ONTO THE PLAINS LATE SATURDAY INTO SUNDAY. STILL A WEEK OUT BUT SOMETHING TO MONITOR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1147 AM CST SUN FEB 23 2014 MOSTLY MVFR CONDITIONS/CEILINGS ARE EXPECTED THROUGH THIS TAF PERIOD. SOME DRYING OF THE ATMOSPHERE MAY ALLOW FOR VFR ACROSS NORTH CENTRAL NEBRASKA THIS AFTERNOON. ANOTHER DISTURBANCE WILL DROP SOUTHEAST TONIGHT WITH SNOW REDEVELOPING ACROSS WESTERN NEBRASKA THIS EVENING...AND THEN SPREADING EAST INTO NORTH CENTRAL AND CENTRAL NEBRASKA LATER TONIGHT INTO MONDAY. WINDS THROUGH THE PERIOD WILL REMAIN LIGHT. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ022>025-035>038-058-059. WINTER STORM WARNING UNTIL 11 AM MST THIS MORNING FOR NEZ056-057. && $$ UPDATE...CDC SHORT TERM...CDC LONG TERM...MASEK AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
521 PM EST SUN FEB 23 2014 .SYNOPSIS... FAST WESTERLY FLOW ALOFT WILL CONTAIN SEVERAL WEAK...AN GENERALLY MOISTURE STARVED UPPER AIR DISTURBANCES WHICH WILL CROSS THE REGION THROUGH TUESDAY. A STRONGER DISTURBANCE DIVING SOUTHEAST FROM THE UPPER MIDWEST WILL INTERACT WITH A STALLED-OUT FRONT ACROSS THE SOUTHEASTERN U.S. AND HELP TO SPIN-UP AN AREA OF LOW PRESSURE ALONG THE OUTER BANKS OF NORTH CAROLINA. A LIGHT...ACCUMULATING SNOW IS POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. A BLAST OF ARCTIC AIR WILL FOLLOW FOR LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... SEVERAL STRIPES OF MAINLY MID AND HIGH CLOUDS WERE PRESENT ACROSS THE FCST AREA THIS AFTERNOON...WITH NO PRECIP NOTED OVER THE PAST SEVERAL HOURS...AND NONE EXPECTED FOR THE NEXT 1-2 HRS. A THICKENING...AND MORE EXTENSIVE CLOUD SHIELD /ASSOCIATED WITH THE PASSAGE OF THE LEFT EXIT REGION OF A 130 KT JET OVER A QUASI STNRY 850 MB FRONTAL BOUNDARY/ WILL QUICKLY OVERSPREAD THE CENTRAL AND WESTERN MTNS LATE THIS AFTERNOON...REACHING THE LOWER SUSQ VALLEY AROUND OR SHORTLY BEFORE DUSK. SHORT TERM...HIGH RES MODELS SHOW A RANGE OF SOLUTIONS WITH RESPECT TO THE AMOUNT AND AREAL COVERAGE OF LIGHT MIXED PRECIP /THEN SNOW/ LATE TODAY THROUGH EARLY TONIGHT ACROSS MAINLY THE SOUTHERN HALF OF PENN. 15Z-17Z HRRR HAS BEEN THE MOST AGGRESSIVE OF ALL OPERATIONAL MODELS /AND NEAR THE HIGH END OF THE SREF PLUMES/ BRINGING A GENERAL 1-3 TENTHS OF LEQ PRECIP TO THE SOUTHERN THIRD TO HALF OF THE STATE LATE TODAY THROUGH ABOUT MIDNIGHT...WHILE THE LATEST HIGH-RES WRF ARW AND OPERATIONAL NAM PAINTS VERY LITTLE OR NO QPF TO THE EAST OF THE LAURELS. SREF DISPLAYS A GOOD COMPROMISE AT THIS POINT...INDICATING A FEW TO SEVERAL HUNDREDTHS OF QPF ACROSS MUCH OF CENTRAL AND SERN PA...WITH OVER A TENTH OF AN INCH ACROSS THE LAURELS. THE P-TYPE THROUGH 00Z WILL BE EITHER PLAIN RAIN /SE ZONES/ OR A LIGHT RAIN AND LIGHT SNOW MIX IN THE CENTRAL MTS /WHERE 925 MB WET BULB TEMPS WILL RIGHT AROUND 0C/...BUT MAINLY SNOW IN THE HIGHER ELEVATIONS. ALL OF THIS TRANSLATES INTO THE LIKELIHOOD OF AN INCH OR TWO OF SNOW ACROSS CAMBRIA AND SOMERSET COUNTY TONIGHT /LOCALLY 3 INCHES POSSIBLE ON THE RIDGES WETS OF RT 219/...WHILE THE CENTRAL AND SOUTHERN VALLEYS SEE A DUSTING TO PERHAPS A LITTLE OVER ONE HALF OF AN INCH. EXPECT LITTLE OR NO SNOW TO THE NORTH OF INTERSTATE 80 LATE TODAY AND TONIGHT. IT/S OFTEN A TRICKY CALL TRYING TO FORECAST THESE WEAKLY FORCED...MOISTURE STARVED MESOSCALE EVENTS. VERY LATE TONIGHT...ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW SHOWERS AND CONFINED TO THE LAURELS. TEMPS FOR THE REST OF THIS AFTN WILL BE IN THE 40S TO NEAR 50F IN THE SOUTHEAST...BUT THE THICKENING CLOUDS WILL HOLD THE MAXES UNDER 40F OVER THE WRN MTNS. THIS WILL BE THE START OF THE DOWNTURN TO OUR TEMPS. COLDER AIR WILL BE ADVECTING INTO THE NW. LAKE ERIE IS PRETTY MUCH FROZEN...SO MOISTURE FLUX WILL BE LOW. HOWEVER...THE MOISTURE FROM THE OTHER LAKES UNDER THE CYCLONIC FLOW ALOFT WILL BE ABLE TO GENERATE PLENTY OF CLOUDS AND A FEW SHSN WITH LOCALIZED LIGHT ACCUMS OF AN INCH OR LESS. MINS TONIGHT /RANGING FROM 10-15F ACROSS THE MTNS...AND LOWER TO MID 20S IN THE SE/ WILL BE NEAR NORMAL IN THE SOUTH BUT ABOUT 5F BELOW NORMAL IN THE NRN MTS. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... A RELATIVELY FLAT SHORTWAVE AND ASSOCIATED 850-700 MB THERMAL TROUGH SLIDES EAST ACROSS THE CWA MONDAY. THERE WILL BE PLENTY OF CLOUDS ACROSS THE NORTH AND WEST. LAKE EFFECT...AND OROGRAPHIC STRATUS AND STRATO CU CLOUD LAYER TEMPS WILL BE SMACK IN THE MIDDLE OF THE FAVORABLE THERMAL RIBBON FOR DENDRITIC GROWTH...SO EXPECT TO SEE OCCASIONAL FLURRIES AND SCTD MTN SNOW SHOWERS WITH AREAS OF LIGHT ACCUMS...MAINLY ON THE RIDGES OF THE LAURELS...AND NW MTNS TO THE WEST OF ROUTE 219. PERHAPS THE MOST NOTICEABLE WEATHER ELEMENT MONDAY WILL BE THE GUSTY WNW WIND. SUSTAINED SPEEDS OF 15 TO 20 MPH AND GUSTS INTO THE L30S ARE LIKELY. MAX TEMPS WILL VARY FROM THE UPPER TEENS TO AROUND 20F IN THE NW. THE SE WILL HAVE SOME DOWNSLOPE AND LIKELY PLENTY OF SUNSHINE /75-90 PERCENT SUN/ BUT A -14C 8H TEMP WILL MEAN THAT IT WILL STRUGGLE TO GET INTO THE M30S. WIND CHILLS WILL RANGE FROM ZERO TO 5 ABOVE AT TIMES ACROSS THE NW MTNS AND LAURELS...TO AROUND 20F IN THE LOWER SUSQ VALLEY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... THE WORK WEEK WILL SEE THE RETURN OF COLDER AIR AND STRONG NORTHWESTERLY FLOW. TEMPERATURES WILL GET SUCCESSIVELY COLDER AS THE WEEK PROGRESSES. A RIDGE WILL RE- ESTABLISH ITSELF OVER THE FAR WESTERN UNITED STATES...WHICH SHOULD ALLOW COLDER AIR TO PUSH SOUTHWARD INTO THE GREAT LAKES AND NORTHEASTERN UNITED STATES. A WEAK CLIPPER SHOULD GLANCE THE NORTHERN HALF OF PA MONDAY NIGHT INTO TUESDAY. THIS SHOULD BRING SOME LIGHT SNOW TO THE NW MTNS...AND FURTHER DECREASE TEMPERATURES. A WEAK SHORT WAVE WILL FOLLOW IN ITS WAKE...WHICH SHOULD BRING ANOTHER CHANCE FOR SNOW TO THE CENTRAL AND NW MTNS. THE NEXT CHANCE FOR MORE WIDESPREAD SNOW WILL BE WEDNESDAY...AS A DEEPENING TROUGH WILL SWING THROUGH THE MIDWEST. MOST OF THE MOISTURE WILL REMAIN OFF THE COAST. HOWEVER...GIVEN THE COLD AIR MASS...COUPLED WITH THE MOIST SOUTHWESTERLY FLOW COULD ALLOW FOR ANOTHER ROUND OF SNOW ACROSS PENNSYLVANIA WEDNESDAY. THERE IS STILL SOME VARIANCES ON SNOW AMOUNT AND POSITION SO HAVE LEFT BROAD POPS WEDNESDAY. THIS SYSTEM SHOULD QUICKLY EXIT THE REGION WEDNESDAY EVENING. HAVE KEPT POPS MAINLY IN THE 30-40 PERCENT RANGE THROUGH MUCH OF THIS PERIOD...THOUGH HAVE INCREASED IT THROUGHOUT THE LAURELS AND THE NW MTNS...DUE TO THE UPSLOPE FLOW ENHANCEMENT. THE LONG RANGE MODELS ARE SHOWING A BRIEF WARMUP AT THE END OF THE WORK WEEK. HOWEVER TEMPERATURES SHOULD REMAIN BELOW FREEZING...AND WILL DROP BACK DOWN NEXT WEEKEND. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/... BAND OF LGT RAIN/SNOW SHOWERS WILL STREAK ACRS THE SRN AIRFIELDS THRU 03-06Z...ACCOMPANIED MVFR TO LOW END VFR CONDS TO THE E OF THE MTNS. ELEVATION FACTOR AT JST RESULTING IN LOWER CONDS WITH IFR TO EVEN LIFR FOR A BRIEF TIME THIS EVE. KEPT MDT/LNS JUST ABOVE MVFR ALTHOUGH A PERIOD OF MVFR IS PSBL AFT 00Z. HIRES ENSEMBLE MEAN SHIFTS ALL PCPN E OF THE AIRSPACE BY 09Z. TO THE NORTH... EXPECT VFR BKN CIGS 050-100 TO PREVAIL INTO TNGT. A MORE TYPICAL POST-FRONTAL NW FLOW PATTERN WILL DEVELOP INTO MONDAY WITH GUSTY WNW WINDS AND -SHSN INVOF BFD BY MORNING. SEVERAL WEAK DISTURBANCES ALOFT WILL ROTATE THROUGH THE REGION INTO EARLY NEXT WEEK...AS A BROAD AND INCREASINGLY COLD CYCLONIC FLOW PATTERN GRIPS MUCH OF THE NERN U.S. COASTAL LOW PRES WILL DEVELOP NEAR OBX AND LIFT NEWD ON WED. A MAINLY DRY COLD FROPA WILL REINFORCE THE COLD AIRMASS ON THURS. A GULF COAST SYSTEM MAY AFFECT THE AREA BY NEXT FRI/SAT. OUTLOOK... MON...MVFR/SHSN NW. VFR ELSEWHERE. TUE-WED...MVFR-IFR PSBL WITH -SN. THURS...MVFR/SNSH NW. VFR ELSEWHERE. FRI...RESTRICTIONS PSBL INTO FRI NGT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...DANGELO/LAMBERT LONG TERM...CERU/EVANEGO AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
357 PM EST SUN FEB 23 2014 .SYNOPSIS... FAST WESTERLY FLOW ALOFT WILL CONTAIN SEVERAL WEAK...AN GENERALLY MOISTURE STARVED UPPER AIR DISTURBANCES WHICH WILL CROSS THE REGION THROUGH TUESDAY. A STRONGER DISTURBANCE DIVING SOUTHEAST FROM THE UPPER MIDWEST WILL INTERACT WITH A STALLED-OUT FRONT ACROSS THE SOUTHEASTERN U.S. AND HELP TO SPIN-UP AN AREA OF LOW PRESSURE ALONG THE OUTER BANKS OF NORTH CAROLINA. A LIGHT...ACCUMULATING SNOW IS POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. A BLAST OF ARCTIC AIR WILL FOLLOW FOR LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... SEVERAL STRIPES OF MAINLY MID AND HIGH CLOUDS WERE PRESENT ACROSS THE FCST AREA THIS AFTERNOON...WITH NO PRECIP NOTED OVER THE PAST SEVERAL HOURS...AND NONE EXPECTED FOR THE NEXT 1-2 HRS. A THICKENING...AND MORE EXTENSIVE CLOUD SHIELD /ASSOCIATED WITH THE PASSAGE OF THE LEFT EXIT REGION OF A 130 KT JET OVER A QUASI STNRY 850 MB FRONTAL BOUNDARY/ WILL QUICKLY OVERSPREAD THE CENTRAL AND WESTERN MTNS LATE THIS AFTERNOON...REACHING THE LOWER SUSQ VALLEY AROUND OR SHORTLY BEFORE DUSK. SHORT TERM...HIGH RES MODELS SHOW A RANGE OF SOLUTIONS WITH RESPECT TO THE AMOUNT AND AREAL COVERAGE OF LIGHT MIXED PRECIP /THEN SNOW/ LATE TODAY THROUGH EARLY TONIGHT ACROSS MAINLY THE SOUTHERN HALF OF PENN. 15Z-17Z HRRR HAS BEEN THE MOST AGGRESSIVE OF ALL OPERATIONAL MODELS /AND NEAR THE HIGH END OF THE SREF PLUMES/ BRINGING A GENERAL 1-3 TENTHS OF LEQ PRECIP TO THE SOUTHERN THIRD TO HALF OF THE STATE LATE TODAY THROUGH ABOUT MIDNIGHT...WHILE THE LATEST HIGH-RES WRF ARW AND OPERATIONAL NAM PAINTS VERY LITTLE OR NO QPF TO THE EAST OF THE LAURELS. SREF DISPLAYS A GOOD COMPROMISE AT THIS POINT...INDICATING A FEW TO SEVERAL HUNDREDTHS OF QPF ACROSS MUCH OF CENTRAL AND SERN PA...WITH OVER A TENTH OF AN INCH ACROSS THE LAURELS. THE P-TYPE THROUGH 00Z WILL BE EITHER PLAIN RAIN /SE ZONES/ OR A LIGHT RAIN AND LIGHT SNOW MIX IN THE CENTRAL MTS /WHERE 925 MB WET BULB TEMPS WILL RIGHT AROUND 0C/...BUT MAINLY SNOW IN THE HIGHER ELEVATIONS. ALL OF THIS TRANSLATES INTO THE LIKELIHOOD OF AN INCH OR TWO OF SNOW ACROSS CAMBRIA AND SOMERSET COUNTY TONIGHT /LOCALLY 3 INCHES POSSIBLE ON THE RIDGES WETS OF RT 219/...WHILE THE CENTRAL AND SOUTHERN VALLEYS SEE A DUSTING TO PERHAPS A LITTLE OVER ONE HALF OF AN INCH. EXPECT LITTLE OR NO SNOW TO THE NORTH OF INTERSTATE 80 LATE TODAY AND TONIGHT. IT/S OFTEN A TRICKY CALL TRYING TO FORECAST THESE WEAKLY FORCED...MOISTURE STARVED MESOSCALE EVENTS. VERY LATE TONIGHT...ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW SHOWERS AND CONFINED TO THE LAURELS. TEMPS FOR THE REST OF THIS AFTN WILL BE IN THE 40S TO NEAR 50F IN THE SOUTHEAST...BUT THE THICKENING CLOUDS WILL HOLD THE MAXES UNDER 40F OVER THE WRN MTNS. THIS WILL BE THE START OF THE DOWNTURN TO OUR TEMPS. COLDER AIR WILL BE ADVECTING INTO THE NW. LAKE ERIE IS PRETTY MUCH FROZEN...SO MOISTURE FLUX WILL BE LOW. HOWEVER...THE MOISTURE FROM THE OTHER LAKES UNDER THE CYCLONIC FLOW ALOFT WILL BE ABLE TO GENERATE PLENTY OF CLOUDS AND A FEW SHSN WITH LOCALIZED LIGHT ACCUMS OF AN INCH OR LESS. MINS TONIGHT /RANGING FROM 10-15F ACROSS THE MTNS...AND LOWER TO MID 20S IN THE SE/ WILL BE NEAR NORMAL IN THE SOUTH BUT ABOUT 5F BELOW NORMAL IN THE NRN MTS. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... A RELATIVELY FLAT SHORTWAVE AND ASSOCIATED 850-700 MB THERMAL TROUGH SLIDES EAST ACROSS THE CWA MONDAY. THERE WILL BE PLENTY OF CLOUDS ACROSS THE NORTH AND WEST. LAKE EFFECT...AND OROGRAPHIC STRATUS AND STRATO CU CLOUD LAYER TEMPS WILL BE SMACK IN THE MIDDLE OF THE FAVORABLE THERMAL RIBBON FOR DENDRITIC GROWTH...SO EXPECT TO SEE OCCASIONAL FLURRIES AND SCTD MTN SNOW SHOWERS WITH AREAS OF LIGHT ACCUMS...MAINLY ON THE RIDGES OF THE LAURELS...AND NW MTNS TO THE WEST OF ROUTE 219. PERHAPS THE MOST NOTICEABLE WEATHER ELEMENT MONDAY WILL BE THE GUSTY WNW WIND. SUSTAINED SPEEDS OF 15 TO 20 MPH AND GUSTS INTO THE L30S ARE LIKELY. MAX TEMPS WILL VARY FROM THE UPPER TEENS TO AROUND 20F IN THE NW. THE SE WILL HAVE SOME DOWNSLOPE AND LIKELY PLENTY OF SUNSHINE /75-90 PERCENT SUN/ BUT A -14C 8H TEMP WILL MEAN THAT IT WILL STRUGGLE TO GET INTO THE M30S. WIND CHILLS WILL RANGE FROM ZERO TO 5 ABOVE AT TIMES ACROSS THE NW MTNS AND LAURELS...TO AROUND 20F IN THE LOWER SUSQ VALLEY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... THE WORK WEEK WILL SEE THE RETURN OF COLDER AIR AND STRONG NORTHWESTERLY FLOW. TEMPERATURES WILL GET SUCCESSIVELY COLDER AS THE WEEK PROGRESSES. A RIDGE WILL RE- ESTABLISHE ITSELF OVER THE FAR WESTERN UNITED STATES...WHICH SHOULD ALLOW COLDER AIR TO PUSH SOUTHWARD INTO THE GREAT LAKES AND NORTHEASTERN UNITED STATES. A WEAK CLIPPER SHOULD GLANCE THE NORTHERN HALF OF PA MONDAY NIGHT INTO TUESDAY. THIS SHOULD BRING SOME LIGHT SNOW TO THE NW MTNS...AND FURTHER DECREASE TEMPERATURES. A WEAK SHORT WAVE WILL FOLLOW IN ITS WAKE...WHICH SHOULD BRING ANOTHER CHANCE FOR SNOW TO THE CENTRAL AND NW MTNS. THE NEXT CHANCE FOR MORE WIDESPREAD SNOW WILL BE WEDNESDAY...AS A DEEPENING TROUGH WILL SWING THROUGH THE MIDWEST. MOST OF THE MOISTURE WILL REMAIN OFF THE COAST. HOWEVER...GIVEN THE COLD AIR MASS...COUPLED WITH THE MOIST SOUTHWESTERLY FLOW COULD ALLOW FOR ANOTHER ROUND OF SNOW ACROSS PENNSYLVANIA WEDNESDAY. THERE IS STILL SOME VARIANCES ON SNOW AMOUNT AND POSITION SO HAVE LEFT BROAD POPS WEDNESDAY. THIS SYSTEM SHOULD QUICKLY EXIT THE REGION WEDNESDAY EVENING. HAVE KEPT POPS MAINLY IN THE 30-40 PERCENT RANGE THROUGH MUCH OF THIS PERIOD...THOUGH HAVE INCREASED IT THROUGHOUT THE LAURELS AND THE NW MTNS...DUE TO THE UPSLOPE FLOW ENHANCEMENT. THE LONG RANGE MODELS ARE SHOWING A BRIEF WARMUP AT THE END OF THE WORK WEEK. HOWEVER TEMPERATURES SHOULD REMAIN BELOW FREEZING...AND WILL DROP BACK DOWN NEXT WEEKEND. && .AVIATION /21Z SUNDAY THROUGH FRIDAY/... SFC COLD FRONT HAS PUSHED TO THE SOUTH OF THE PENN/MD BORDER AT MIDDAY. INCREASING DEEP LAYER LIFT WILL CAUSE CLOUDS TO OVERSPREAD THE LAUREL HIGHLANDS AND NW MTNS LATE THIS AFTERNOON...AND THE REST OF THE REGION TONIGHT. INCREASING...DOWNSLOPE WESTERLY FLOW OF AROUND 10 KTS WILL COMBINE WITH THE MODERATE TEMPS ALOFT TO PRODUCE BREAKS IN THE LAYERED MID AND HIGH CLOUDS BUT NOTHING MORE THAN A SPRINKLE OR PASSING FLURRY THIS AFTERNOON. PERIODS OF MVFR...AND EVEN SOME BRIEF IFR...WILL DEVELOP IN SNOW SHOWERS /MAINLY ACROSS THE LAUREL HIGHLANDS LATE TODAY...AND TONIGHT/. SOMEWHAT LOWER PROBABILITY EXISTS FOR THESE FLIGHT REDUCTIONS SPREADING INTO THE KMDT AND KLNS AREAS TONIGHT. KEPT VSBYS JUST A TAD ABOVE MVFR AT KMDT...KLNS AND KTHV AS SOME AREAS OF LIGHT RAIN/SNOW SPREAD ACROSS THE REGION THIS EVENING UNTIL AROUND 05Z. ELSEWHERE...ACROSS MUCH OF CENTRAL AND NRN PENN...GENERALLY VFR BKN CIGS WILL PREVAIL WITH JUST SOME SPOTTY LIGHT RAIN/SNOW SHOWERS...CHANGING TO SNOW SHOWERS TONIGHT. OUTLOOK... MON...MVFR/SHSN NW. VFR ELSEWHERE. TUE...MVFR-IFR PSBL IN -SHSN. VFR ELSEWHERE. WED...PSBL REDUCTIONS DUE TO LOW PRES DEVELOPING OVR NC MOVG NEWD. THUR...MVFR/SNSH NW. VFR ELSEWHERE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...DANGELO/LAMBERT LONG TERM...CERU/EVANEGO AVIATION...LAMBERT/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
231 PM EST SUN FEB 23 2014 .SYNOPSIS... FAST WESTERLY FLOW ALOFT WILL CONTAIN SEVERAL WEAK...AN GENERALLY MOISTURE STARVED UPPER AIR DISTURBANCES WHICH WILL CROSS THE REGION THROUGH TUESDAY. A STRONGER DISTURBANCE DIVING SOUTHEAST FROM THE UPPER MIDWEST WILL INTERACT WITH A STALLED-OUT FRONT ACROSS THE SOUTHEASTERN U.S. AND HELP TO SPIN-UP AN AREA OF LOW PRESSURE ALONG THE OUTER BANKS OF NORTH CAROLINA. A LIGHT...ACCUMULATING SNOW IS POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. A BLAST OF ARCTIC AIR WILL FOLLOW FOR LATE IN THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... SEVERAL STRIPES OF MAINLY MID AND HIGH CLOUDS WERE PRESENT ACROSS THE FCST AREA THIS AFTERNOON...WITH NO PRECIP NOTED OVER THE PAST SEVERAL HOURS...AND NONE EXPECTED FOR THE NEXT 1-2 HRS. A THICKENING...AND MORE EXTENSIVE CLOUD SHIELD /ASSOCIATED WITH THE PASSAGE OF THE LEFT EXIT REGION OF A 130 KT JET OVER A QUASI STNRY 850 MB FRONTAL BOUNDARY/ WILL QUICKLY OVERSPREAD THE CENTRAL AND WESTERN MTNS LATE THIS AFTERNOON...REACHING THE LOWER SUSQ VALLEY AROUND OR SHORTLY BEFORE DUSK. SHORT TERM...HIGH RES MODELS SHOW A RANGE OF SOLUTIONS WITH RESPECT TO THE AMOUNT AND AREAL COVERAGE OF LIGHT MIXED PRECIP /THEN SNOW/ LATE TODAY THROUGH EARLY TONIGHT ACROSS MAINLY THE SOUTHERN HALF OF PENN. 15Z-17Z HRRR HAS BEEN THE MOST AGGRESSIVE OF ALL OPERATIONAL MODELS /AND NEAR THE HIGH END OF THE SREF PLUMES/ BRINGING A GENERAL 1-3 TENTHS OF LEQ PRECIP TO THE SOUTHERN THIRD TO HALF OF THE STATE LATE TODAY THROUGH ABOUT MIDNIGHT...WHILE THE LATEST HIGH-RES WRF ARW AND OPERATIONAL NAM PAINTS VERY LITTLE OR NO QPF TO THE EAST OF THE LAURELS. SREF DISPLAYS A GOOD COMPROMISE AT THIS POINT...INDICATING A FEW TO SEVERAL HUNDREDTHS OF QPF ACROSS MUCH OF CENTRAL AND SERN PA...WITH OVER A TENTH OF AN INCH ACROSS THE LAURELS. THE P-TYPE THROUGH 00Z WILL BE EITHER PLAIN RAIN /SE ZONES/ OR A LIGHT RAIN AND LIGHT SNOW MIX IN THE CENTRAL MTS /WHERE 925 MB WET BULB TEMPS WILL RIGHT AROUND 0C/...BUT MAINLY SNOW IN THE HIGHER ELEVATIONS. ALL OF THIS TRANSLATES INTO THE LIKELIHOOD OF AN INCH OR TWO OF SNOW ACROSS CAMBRIA AND SOMERSET COUNTY TONIGHT /LOCALLY 3 INCHES POSSIBLE ON THE RIDGES WETS OF RT 219/...WHILE THE CENTRAL AND SOUTHERN VALLEYS SEE A DUSTING TO PERHAPS A LITTLE OVER ONE HALF OF AN INCH. EXPECT LITTLE OR NO SNOW TO THE NORTH OF INTERSTATE 80 LATE TODAY AND TONIGHT. IT/S OFTEN A TRICKY CALL TRYING TO FORECAST THESE WEAKLY FORCED...MOISTURE STARVED MESOSCALE EVENTS. VERY LATE TONIGHT...ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW SHOWERS AND CONFINED TO THE LAURELS. TEMPS FOR THE REST OF THIS AFTN WILL BE IN THE 40S TO NEAR 50F IN THE SOUTHEAST...BUT THE THICKENING CLOUDS WILL HOLD THE MAXES UNDER 40F OVER THE WRN MTNS. THIS WILL BE THE START OF THE DOWNTURN TO OUR TEMPS. COLDER AIR WILL BE ADVECTING INTO THE NW. LAKE ERIE IS PRETTY MUCH FROZEN...SO MOISTURE FLUX WILL BE LOW. HOWEVER...THE MOISTURE FROM THE OTHER LAKES UNDER THE CYCLONIC FLOW ALOFT WILL BE ABLE TO GENERATE PLENTY OF CLOUDS AND A FEW SHSN WITH LOCALIZED LIGHT ACCUMS OF AN INCH OR LESS. MINS TONIGHT /RANGING FROM 10-15F ACROSS THE MTNS...AND LOWER TO MID 20S IN THE SE/ WILL BE NEAR NORMAL IN THE SOUTH BUT ABOUT 5F BELOW NORMAL IN THE NRN MTS. && .SHORT TERM /MONDAY/... A RELATIVELY FLAT SHORTWAVE AND ASSOCIATED 850-700 MB THERMAL TROUGH SLIDES EAST ACROSS THE CWA MONDAY. THERE WILL BE PLENTY OF CLOUDS ACROSS THE NORTH AND WEST. LAKE EFFECT...AND OROGRAPHIC STRATUS AND STRATO CU CLOUD LAYER TEMPS WILL BE SMACK IN THE MIDDLE OF THE FAVORABLE THERMAL RIBBON FOR DENDRITIC GROWTH...SO EXPECT TO SEE OCCASIONAL FLURRIES AND SCTD MTN SNOW SHOWERS WITH AREAS OF LIGHT ACCUMS...MAINLY ON THE RIDGES OF THE LAURELS...AND NW MTNS TO THE WEST OF ROUTE 219. PERHAPS THE MOST NOTICEABLE WEATHER ELEMENT MONDAY WILL BE THE GUSTY WNW WIND. SUSTAINED SPEEDS OF 15 TO 20 MPH AND GUSTS INTO THE L30S ARE LIKELY. MAX TEMPS WILL VARY FROM THE UPPER TEENS TO AROUND 20F IN THE NW. THE SE WILL HAVE SOME DOWNSLOPE AND LIKELY PLENTY OF SUNSHINE /75-90 PERCENT SUN/ BUT A -14C 8H TEMP WILL MEAN THAT IT WILL STRUGGLE TO GET INTO THE M30S. WIND CHILLS WILL RANGE FROM ZERO TO 5 ABOVE AT TIMES ACROSS THE NW MTNS AND LAURELS...TO AROUND 20F IN THE LOWER SUSQ VALLEY. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... THE WORK WEEK WILL SEE THE RETURN OF COLDER AIR AND STRONG NORTHWESTERLY FLOW. TEMPERATURES WILL GET SUCCESSIVELY COLDER AS THE WEEK PROGRESSES. AS A RIDGE RE- ESTABLISHES ITSELF OVER THE FAR WESTERN UNITED STATES...ALLOWING COLDER AIR TO PUSH SOUTHWARD INTO THE GREAT LAKES AND NORTHEASTERN UNITED STATES. A SECOND SYSTEM COULD SPREAD ANOTHER ROUND OF LIGHT SNOW ACROSS PENNSYLVANIA EARLY TUESDAY...WITH A POTENTIALLY MORE SIGNIFICANT SYSTEM POSSIBLY BRINGING ADDITIONAL SNOW TO THE REGION TUES NIGHT INTO WEDNESDAY. KEPT POPS IN THE 30-40 PERCENT RANGE THROUGH MUCH OF THIS PERIOD...AS CONFIDENCE IN THE TIMING AND DETAILS OF THESE SYSTEMS IS LOW AT THIS RANGE. THE 12Z GEFS SHOWS 850 TEMPS DROPPING TO -2SD FOR THU AND FRI...SO IT LOOKS LIKE A COLD END TO NEXT WEEK IS IN STORE. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... SFC COLD FRONT HAS PUSHED TO THE SOUTH OF THE PENN/MD BORDER AT MIDDAY. INCREASING DEEP LAYER LIFT WILL CAUSE CLOUDS TO OVERSPREAD THE LAUREL HIGHLANDS AND NW MTNS LATE THIS AFTERNOON...AND THE REST OF THE REGION TONIGHT. INCREASING...DOWNSLOPE WESTERLY FLOW OF AROUND 10 KTS WILL COMBINE WITH THE MODERATE TEMPS ALOFT TO PRODUCE BREAKS IN THE LAYERED MID AND HIGH CLOUDS BUT NOTHING MORE THAN A SPRINKLE OR PASSING FLURRY THIS AFTERNOON. PERIODS OF MVFR...AND EVEN SOME BRIEF IFR...WILL DEVELOP IN SNOW SHOWERS /MAINLY ACROSS THE LAUREL HIGHLANDS LATE TODAY...AND TONIGHT/. SOMEWHAT LOWER PROBABILITY EXISTS FOR THESE FLIGHT REDUCTIONS SPREADING INTO THE KMDT AND KLNS AREAS TONIGHT. KEPT VSBYS JUST A TAD ABOVE MVFR AT KMDT...KLNS AND KTHV AS SOME AREAS OF LIGHT RAIN/SNOW SPREAD ACROSS THE REGION THIS EVENING UNTIL AROUND 05Z. ELSEWHERE...ACROSS MUCH OF CENTRAL AND NRN PENN...GENERALLY VFR BKN CIGS WILL PREVAIL WITH JUST SOME SPOTTY LIGHT RAIN/SNOW SHOWERS...CHANGING TO SNOW SHOWERS TONIGHT. OUTLOOK... MON...MVFR/SHSN NW. VFR ELSEWHERE. TUE...MVFR-IFR PSBL IN -SHSN. VFR ELSEWHERE. WED...PSBL REDUCTIONS DUE TO LOW PRES DEVELOPING OVR NC MOVG NEWD. THUR...MVFR/SNSH NW. VFR ELSEWHERE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...CERU/EVANEGO AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1121 AM CST SUN FEB 23 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 301 AM CST SUN FEB 23 2014 CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING FROM THE EASTERN PACIFIC INTO ALASKA...A BROAD UPPER LOW OVER THE CANADIAN ARCHIPELAGO...AND BROAD TROUGHING ACROSS ALL OF SOUTHERN CANADA INTO THE UPPER MIDWEST. SHORTWAVES OF NOTE FOR THIS FORECAST INCLUDE ONE OVER WEST CENTRAL BRITISH COLUMBIA...ONE OVER CENTRAL ALBERTA...AND THE LAST AS PART OF THE UPPER LOW ON THE WESTERN SIDE OF THE CANADIAN ARCHIPELAGO. A NORTHWEST 925MB FLOW CONTINUES TO GRADUALLY DRAW COLDER IN OUT OF CANADA TOWARDS THE FORECAST AREA...NOTED BY THE 00Z MPX SOUNDING AT -15C. THAT SAME SOUNDING ALSO CONTINUES TO DEPICT PLENTY OF DRY AIR...RESULTING IN CLEAR SKIES EARLY THIS MORNING. COMBINATION OF THE CLEAR SKIES AND COOLING 925MB TEMPS HAS ALLOWED TEMPERATURES TO DROP INTO THE SINGLE DIGITS ABOVE ZERO. IF THE 5 TO 15 MPH BREEZE WAS NOT PRESENT TO KEEP THE AIR MIXED...TEMPERATURES WOULD PROBABLY BE A LOT COLDER. OVERALL LITTLE CHANGE IS PROGGED BY MODELS TO OCCUR IN THE NEXT 24 HOURS IN TERMS OF THE UPPER LEVEL PATTERN OVER THE UPPER MIDWEST AND THE FORECAST AREA. WE STILL REMAIN UNDER THE INFLUENCE OF A DRY NORTHWEST LOW TO MID LEVEL FLOW...WHICH SHOULD HELP KEEP SKIES MAINLY CLEAR THROUGH TODAY AND MUCH OF TONIGHT. THERE ARE SOME INDICATIONS OF CIRRUS APPROACHING LOCATIONS WEST OF THE MISSISSIPPI RIVER LATE TONIGHT...BUT THATS REALLY ABOUT IT FOR CLOUDS. 925MB TEMPS TODAY ARE FORECAST TO RANGE BETWEEN -13 AND -16C...ABOUT 1-2C COLDER THAN YESTERDAY. THEREFORE...WE SHOULD SEE HIGHS JUST SLIGHTLY COOLER THAN YESTERDAY. SKIES STAYING CLEAR THROUGH MUCH OF TONIGHT PLUS 925MB TEMPS FALLING TO -14 TO -19C...COLDEST OVER WISCONSIN...SHOULD ALLOW FOR LOWS IN MOST LOCATIONS IN THE SINGLE DIGITS BELOW ZERO. AGAIN...THERE LOOKS TO BE A PERSISTENT NORTHWEST BREEZE THROUGH TONIGHT HELPING TO PREVENT DECOUPLING. STILL...THE TYPICAL COLD SPOTS COULD TRY TO APPROACH -10F. WIND CHILLS LOOK TO GET CLOSE TO ADVISORY CRITERIA...BUT TOO MARGINAL AT THIS POINT TO ISSUE AN ADVISORY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 301 AM CST SUN FEB 23 2014 THE 2 MAIN IMPACTS REMAIN FOR THE LONG TERM... 1. POTENTIAL FOR SOME SNOW LATE MONDAY AFTERNOON AND NIGHT 2. THE BITTER COLD AIR...ESPECIALLY TUESDAY NIGHT AND BEYOND. REGARDING IMPACT NUMBER 1...THE SHORTWAVES CURRENTLY OVER CENTRAL BRITISH COLUMBIA AND ALBERTA REMAIN PROGGED TO PHASE TOGETHER OVER THE DAKOTAS ON MONDAY...THEN QUICKLY SLIDE THROUGH THE FORECAST AREA AROUND 06Z TUESDAY. MOISTURE IS LACKING FOR THESE SHORTWAVES...WITH PRECIPITABLE WATER CLIMBING TO 0.1-0.2 OF AN INCH. HOWEVER...SOME WEAK ISENTROPIC LIFT ON THE 275-280K SURFACES COMBINED WITH DPVA AHEAD OF THE SHORTWAVES SHOULD BE ENOUGH TO SQUEEZE OUT SOME LIGHT SNOW. SNOW SHOULD BE SOMEWHAT FLUFFY...THOUGH THE BULK OF THE LIFT LOOKS TO OCCUR ABOVE THE DENDRITIC GROWTH ZONE. TIMING WISE...MODELS CONTINUE TO SLOW DOWN THE SNOW MOVING INTO THE AREA...WITH THE 23.00Z NAM/GFS/CANADIAN/ECMWF KEEPING MUCH OF THE SNOW WEST OF THE AREA PRIOR TO 00Z TUESDAY. ITS MORE OF A MONDAY NIGHT SNOW NOW. DID RAISE CHANCES UP FOR MONDAY EVENING WEST OF THE MISSISSIPPI RIVER WITH GOOD MODEL AGREEMENT FOR THE SNOW THEN. AFTER 06Z MONDAY... MODELS DIVERGE ON HOW MUCH SNOW MIGHT BE LEFT WITH THE 23.00Z GFS/CANADIAN DRY WHEREAS THE NAM AND ECMWF STILL HAVE SOME SNOW LEFT. SPLIT THE DIFFERENCE AND HAVE SOME 20-30 PERCENT CHANCES FOR NOW. IT APPEARS MUCH OF THIS HAS TO DO WITH THE TIMING OF THE PHASED SHORTWAVE. NOW IMPACT NUMBER 2...THE COLD. IN THE WAKE OF MONDAY NIGHTS SHORTWAVE TROUGH...925MB TEMPS FALL TO -15 TO -20C. A SECOND AND MORE POTENT COLD SURGE REMAINS PROGGED TO PLUNGE INTO THE AREA TUESDAY NIGHT...DROPPING 925MB TEMPS TO -23 TO -25C BY 12Z WEDNESDAY. THIS SURGE IS BEHIND THAT SHORTWAVE CURRENTLY OVER THE CANADIAN ARCHIPELAGO. WIND CHILL ADVISORIES SEEM ALL BUT LIKELY TUESDAY NIGHT INTO WEDNESDAY MORNING. A BRIEF BOUT OF WARM ADVECTION IS SUGGESTED FOR WEDNESDAY AHEAD OF AN ARCTIC COLD FRONT DROPPING SOUTH OUT OF CANADA...THOUGH IT APPEARS A BRISK WEST WIND WILL ACCOMPANY IT. THEN ITS BACK TO THE COLD AS ANOTHER IMPRESSIVE SURGE OF ARCTIC AIR DIVES SOUTH INTO THE REGION FOR THURSDAY ON SOME BRISK NORTHWEST WINDS. 925MB TEMPS FROM THE 23.00Z GFS AND ECMWF DROP TO -23 TO -27C BY 12Z THURSDAY...WHILE 850MB TEMPS APPROACH -30C ACROSS OUR NORTH. THESE READINGS ARE NEARLY 3 STANDARD DEVIATIONS BELOW NORMAL. BEYOND THURSDAY...MODELS BEGIN TO DIVERGE A BIT WITH THE HANDLING OF THE COLD AIR. THE 23.00Z GFS TRIES TO MODIFY THE COLD AIR SOMEWHAT FROM THE FLOW BECOMING MORE ZONAL ACROSS THE NORTHERN TIER OF THE U.S.. THE 23.00Z ECMWF ALONG WITH EXTRAPOLATION OF THE CANADIAN HAS THAT SAME ZONAL FLOW...JUST A SMIDGE FURTHER SOUTH...WHICH RESULTS IN A CONTINUATION OF THE DEEP FREEZE. FOR THE FORECAST LEANED A BIT CLOSER TOWARDS THE ECMWF. OVERALL FOR TEMPERATURES TUESDAY THROUGH SATURDAY...STAYED CLOSE TO A CONSENSUS OF 30 DAY BIAS CORRECTED GUIDANCE...WHICH PERFORMED WELL IN PAST COLD SPELLS THIS WINTER. THURSDAY NIGHT COULD BE VERY COLD WITH A SURFACE RIDGE PARKED OVERHEAD. WOULD NOT BE SURPRISED IF SOME OF THE TYPICAL COLD SPOTS TO APPROACH -30F. GIVEN HOW DEEP SOME OF THE FROST IS ALREADY...WATER MAINS UNDER ROADS WILL NEED TO BE WATCHED CLOSELY. LUCKILY THE HIGHER SUN ANGLE CAN HEAT THE TOP OF THE ROAD SURFACES MORE NOW THAN IN JANUARY...BUT STILL THIS COLD AIR WILL NOT BE GOOD. THERE ARE STRONG INDICATIONS TOO FROM THE CFS THAT THE BELOW NORMAL WEATHER COULD PERSIST THROUGH ALL OF MARCH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1121 AM CST SUN FEB 23 2014 PLAN ON VFR CONDITIONS THROUGH THE PERIOD. HIGH PRESSURE REMAINING ANCHORED ACROSS THE NORTHERN PLAINS THROUGH TOMORROW WILL KEEP NORTHWESTERLY WINDS 10 TO 15 KTS AT THE TAF SITES. FOR THIS AFTERNOON...25 KT GUSTS AT KRST DUE TO MIXING UP TO 925 MB WILL SUBSIDE BY SUNSET. HOWEVER A TIGHT ENOUGH PRESSURE GRADIENT WILL REMAIN IN PLACE TONIGHT TO KEEP BOUNDARY LAYER FROM DECOUPLING. HIGH LEVEL CLOUDS AROUND 15 KFT SHOULD SPILL EASTWARD OVER THE AREA LATE TOMORROW MORNING IN ADVANCE OF A PASSING SHORTWAVE. && .CLIMATE... ISSUED AT 301 AM CST SUN FEB 23 2014 GIVEN ALL THE COLD AIR TO ROUND OUT THE MONTH OF FEBRUARY...HERE IS HOW FEBRUARY AND THE WINTER WOULD STACK UP BASED ON THE CURRENT FORECAST... ...FOR THE MONTH OF FEBRUARY... LA CROSSE... 9.5 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1873... 3.9 1936... 4.3 1899... 9.4 ROCHESTER... 6.9 AVERAGE TEMPERATURE...4TH COLDEST COLDER FEBRUARYS... 1936... 0.5 1979... 5.7 1917... 6.0 ...FOR THE WINTER...DECEMBER THROUGH FEBRUARY... LA CROSSE... 11.6 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1872-1873... 8.4 1874-1875... 10.5 1977-1978... 11.4 1935-1936... 11.4 ROCHESTER... 8.9 AVERAGE TEMPERATURE...5TH COLDEST COLDER WINTERS... 1978-1979... 5.6 1886-1887... 5.9 1935-1936... 8.1 1977-1978... 8.7 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION...ZT CLIMATE......AJ