Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/12/16


AREA FORECAST DISCUSSION
NWS ALBANY NY
1243 AM EST SUN JAN 10 2016 .SYNOPSIS... A STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT LAKES REGION SUNDAY BRINGING A WIDESPREAD RAIN TO OUR REGION ALONG WITH STRONG EAST TO SOUTHEAST WINDS AND A SURGE A VERY MILD TEMPERATURES. WITH THE PASSAGE OF THE SYSTEM...A COLDER AND MORE SEASONABLE AIR MASS WILL BE USHERED BACK INTO THE REGION. AS THE COLDER AIR MOVES OVER THE RELATIVELY WARMER WATERS OF LAKE ONTARIO LAKE EFFECT SNOW WILL DEVELOP AND IMPACT THE WESTERN ADIRONDACKS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1225 AM EST...REGIONAL MOSAIC RADAR CONTINUES TO SHOW MAINLY DRY CONDITIONS OVER THE AREA...WITH JUST A FEW SPOTTY SPRINKLES AROUND. TEMPS CONTINUE TO HOLD STEADY IN THE 30S TO LOW 40S OVER MUCH OF THE REGION. A FEW MESONET OBS OVER WESTERN NEW ENGLAND ARE CLOSE TO THE FREEZING MARK...BUT EVERYWHERE ELSE IS ABOVE FREEZING. ANY PRECIP IS VERY LIGHT AND SPOTTY...AND PERHAPS NOT EVEN REACHING THE GROUND. A STRONG LOW PRESSURE SYSTEM WILL BEGIN TO IMPACT THE REGION LATE TONIGHT. STEADY RAIN WILL OVERSPREAD THE AREA FROM SOUTHWEST TO NORTHEAST LATE TONIGHT TOWARDS SUNRISE AS THE SYSTEM`S WARM FRONT APPROACHES AND ITS VERY STRONG LOW LEVEL JET BEGINS TO MOVE INTO THE REGION. THE 03Z 3KM HRRR SUGGEST THIS WON/T BE UNTIL AFTER 11Z FOR FAR SOUTHERN AREAS...AND WON/T REACH THE CAPITAL REGION UNTIL NEARLY 13Z. THE MODEL HAS CONTINUED TO SHOW THIS WITH EACH RUN...SO HAVE SLOWED THE TIMING OF POPS BACK IN OUR GRIDS. EAST TO SOUTHEAST SURFACE WINDS WILL BE ON THE INCREASE ESPECIALLY LATE. THEY ARE EXPECTED TO BE QUITE STRONG BEFORE SUNRISE. A WIND ADVISORY HAS BEEN ISSUED BEGINNING AT 5 AM FOR THE WESTERN ADIRONDACKS...SCHOHARIE COUNTY...THE HELDERBERGS...EASTERN CATSKILLS...NORTHERN AND CENTRAL TACONICS...BERKSHIRES...AND SOUTHERN GREEN MOUNTAINS OF SOUTHERN VERMONT. THE STRONGEST WINDS AND HIGHEST WIND GUSTS ARE EXPECTED IN AREAS WHERE THE LOCAL TERRAIN FUNNELS EAST TO SOUTHEAST FLOW. TEMPS ARE CURRENTLY IN THE MID 30S TO LOW 40S. LOWS WILL BE THIS EVENING...AS THE PERSISTENT SOUTHERLY FLOW SHOULD ALLOW TEMPS TO RISE OVERNIGHT. ALL AREAS WILL BE ABOVE FREEZING BY THE TIME STEADY PRECIP MOVES IN LATE TONIGHT...AND THAT PRECIP SHOULD BE IN THE FORM OF RAIN. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... WIDESPREAD RAINFALL...STRONG EAST-SOUTHEAST WINDS AND VERY MILD WITH SOME RECORD BREAKING TEMPERATURES EXPECTED. THE INTERACTION OF NORTHERN AND SOUTHERN STREAM ENERGY WILL RESULT IN A DEEP/STRONG LOW PRESSURE SYSTEM WHICH WILL MOVE ACROSS THE GREAT LAKES ON SUNDAY. WITH THE SYSTEM PASSING TO OUR NORTH AND WEST WILL BE ON THE WARM SIDE OF THE SYSTEM AND WILL GET A BRIEF SURGE OF VERY MILD AIR INTO THE REGION ON SUNDAY. RECORD HIGH TEMPERATURES ARE FORECAST FOR ALBANY AND POUGHKEEPSIE. REFER TO OUR CLIMATE SECTION FOR DETAILS. THE WIND ADVISORY IS IN EFFECT THROUGH THE MORNING HOURS... NOONTIME...AS THE VERY STRONG LOW LEVEL JET MOVES ACROSS THE REGION. ENSEMBLES INDICATE +3-4 STANDARD DEVIATIONS FOR THE 850 MB WINDS. GUIDANCE SHOWS 30AGL LEVELS WINDS OF 45 TO 55 KNOTS SUNDAY MORNING ACROSS THE AREAS HAVE ISSUED THE WIND ADVISORY FOR. PRECIPITABLE WATER VALUES WILL BE VERY HIGH FOR THIS TIME OF YEAR...2-3 STANDARD DEVIATIONS ABOVE NORMAL. EXPECTING RAINFALL AMOUNTS OF ONE HALF INCH TO AN INCH AND A HALF WITH SOME LOCALIZED TOTALS OF AROUND TWO INCHES POSSIBLE IN THE EASTERN CATSKILLS. THE NYS MESONET SITES INDICATED 2 INCH SOIL TEMPERATURES AT OR NEAR THE FREEZING MARK SO RUNOFF POTENTIAL WILL BE HIGH. ALSO A MAJORITY OF THE RAINFALL IS EXPECTED TO OCCUR IN SUNDAY MORNING IN A 6 TO 9 HOUR PERIOD...SO THERE ARE SOME CONCERNS FOR SOME URBAN/POOR DRAINAGE/LOW LYING AREA FLOODING. A SURGE OF VERY MILD AIR WILL ALSO RESULT SOME RUNOFF FROM SNOW MELT. MAIN STEM RIVER FLOODING IS NOT EXPECTED...REFER TO THE HYDROLOGY SECTION FOR DETAILS. GUIDANCE INDICATES NEGATIVE SHOWALTER VALUES MOVING ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA ON SUNDAY MAINLY IN THE MORNING JUST AHEAD OF THE WARM FRONT. ALSO THE STORM PREDICTION CENTER HAS THE AREA MAINLY SOUTH AND EAST OF THE CAPITAL DISTRICT HIGHLIGHTED FOR GENERAL THUNDER. SO HAVE A SLIGHT CHANCE OF THUNDER MENTIONED. WITH THE PASSAGE OF THE SYSTEM AND ITS COLD FRONT...A COLDER AND MORE SEASONABLE AIRMASS WILL BE USHERED INTO THE REGION ON BRISK AND GUSTY WESTERLY WINDS AS THE STORM CONTINUES TO DEEPEN. THE WESTERLY WINDS WILL STRENGTHEN OVERNIGHT AND SHOULD BE STRONG THROUGH MUCH OF MONDAY. THEY COULD APPROACH WIND ADVISORY CRITERIA WITH GUSTS GREATER THAN 45 MPH. HAVE THREAT HIGHLIGHTED IN OUR HAZARDOUS WEATHER OUTLOOK. AS THIS COLDER AIR MOVES OVER THE RELATIVELY WARMER WATERS OF LAKE ONTARIO LAKE EFFECT SNOW WILL DEVELOP SUNDAY NIGHT AND IMPACT THE WESTERN ADIRONDACKS. BASED ON THE LATEST GUIDANCE ADVISORY TO POSSIBLY WARNING CRITERIA LAKE EFFECT SNOWS ARE POSSIBLE LATE SUNDAY NIGHT INTO MONDAY EVENING ACROSS NORTHERN HERKIMER COUNTY INTO HAMILTON COUNTY. AT THIS TIME...THE MAIN THREAT AREA IS THE NORTHERN HERKIMER COUNTY IN THE VICINITY OF ROUTE 28...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH TO ISSUE A WATCH. HAVE THREAT HIGHLIGHTED IN OUR HAZARDOUS WEATHER OUTLOOK. && .LONG TERM /TUESDAY THROUGH SATURDAY/... A SEASONABLY COLD AIR MASS WILL BE IN PLACE TO START THE EXTENDED PERIOD FOR TUESDAY WITH TEMPS REACHING THE MID 20S TO MID 30S. AT THE SAME TIME...A FAST MOVING CLIPPER SYSTEM WILL BE APPROACHING THE AREA FROM THE GREAT LAKES FOR TUESDAY INTO TUESDAY NIGHT. WITH TEMPS BEING COLD ENOUGH...ANY PRECIP WILL BE IN THE FORM OF SNOW SHOWERS...ALTHOUGH MOISTURE WILL BE QUITE LIMITED WITH THIS SYSTEM. THE BEST FORCING OF THIS SYSTEM LOOKS TO REMAIN NORTH OF THE AREA...SO THE HIGHEST POPS/QPF LOOK TO BE FOR AREAS NORTH OF THE CAPITAL REGION AND ACROSS THE HIGH TERRAIN. MOST PLACES LOOK TO SEE SOME SNOW SHOWERS BY EITHER LATE IN THE DAY TUESDAY OR INTO TUESDAY NIGHT. HOWEVER...MOST VALLEY AREAS WILL ONLY SEE A COATING OF ACCUMULATION...ALTHOUGH A FEW INCHES WILL BE POSSIBLE FOR FAR NORTHERN AND HIGHER ELEVATIONS. LOW TEMPS ON TUES NIGHT WILL FALL INTO THE TEENS TO LOW 20S. THIS CLIPPER STORM WILL HELP DEVELOP A COASTAL LOW OFF THE COAST OF NORTHERN NEW ENGLAND FOR WEDNESDAY...ALTHOUGH THIS SYSTEM WILL BE A BIT TOO FAR AWAY TO HAVE A BIG IMPACT ON OUR WEATHER. HOWEVER...THE UPPER LEVEL TROUGH WILL BE PASSING ACROSS THE AREA FOR WEDNESDAY...SO SOME ADDITIONAL SNOW SHOWERS/FLURRIES WILL BE POSSIBLE...ESP FOR NORTHERN AND HIGH TERRAIN AREAS. TEMPS LOOK TO ONLY REACH THE MID TEENS TO MID 20S...WITH A CHILLY WESTERLY WIND AS WELL. LOWS ONLY WED NIGHT WILL MAINLY BE IN THE TEENS...ALTHOUGH THE THE HIGHEST ELEVATIONS WILL FALL INTO THE SINGLE DIGITS. FOR THE REMAINDER OF THE WORK WEEK...IT WILL STAY FAIRLY COLD...WITH LAKE EFFECT SNOW IMPACTING NORTHERN AND WESTERN AREAS THANKS TO 850 HPA TEMPS OF -17 TO -19 DEGREES C. ALTHOUGH THERE LOOKS TO BE SOME VARIATION IN THE WIND DIRECTION WHICH WILL KEEP THE BANDS MOVING AROUND...SOME ACCUMULATION LOOKS TO OCCUR FOR THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY...AND IT/S POSSIBLE THAT SOME SNOW SHOWERS/FLURRIES REACH AS FAR AS THE SARATOGA AND CAPITAL REGIONS AT TIMES AS WELL. HIGHS ON THURS/FRI LOOK TO ONLY REACH THE 20S...AND OVERNIGHT LOWS WILL MAINLY BE IN THE TEENS. THE LAKE EFFECT LOOKS TO FINALLY END BY THE WEEKEND...AS HIGH PRESSURE APPROACHING THE AREA ALLOWS THE INVERSION HEIGHT TO LOWER. IT LOOKS TO REMAIN SEASONABLY CHILLY THOUGH...WITH HIGHS CONTINUED TO BE ONLY IN THE 20S TO LOW 30S. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... STRENGTHENING LOW PRESSURE WILL TRACK NORTHWARD ACROSS THE EASTERN GREAT LAKES AND INTO SOUTHEAST CANADA LATE TONIGHT INTO SUNDAY. A WARM FRONT ASSOCIATED WITH THIS LOW WILL APPROACH FROM THE SOUTH SUNDAY AFTERNOON...FOLLOWED BY A COLD/OCCLUDED FRONT FROM THE WEST/SOUTHWEST SUNDAY EVENING. CURRENTLY...MVFR CIGS ARE FAIRLY WIDESPREAD AT THE TAF SITES...WITH AREAS OF IFR/LIFR CIGS AT KPSF. THESE CONDITIONS ARE EXPECTED REMAIN FAIRLY STABLE THROUGH DAYBREAK. SOME PATCHY DRIZZLE WILL BE POSSIBLE THROUGH 12Z/SUNDAY. THEN...AN AREA OF STEADY RAIN WILL QUICKLY MOVE FROM SOUTH TO NORTH AROUND OR SHORTLY AFTER DAYBREAK SUNDAY...OVERSPREADING THE TAF SITES BETWEEN 12Z-14Z/SUNDAY. RAINFALL INTENSITY WILL BE MODERATE...ALTHOUGH A FEW PERIODS OF HEAVY RAIN WILL BE POSSIBLE. IN FACT...CAN NOT COMPLETELY RULE OUT THE POSSIBILITY OF AN EMBEDDED THUNDERSTORM...ESP AT KPOU AND KPSF. MAINLY IFR/LIFR CONDITIONS ARE EXPECTED ONCE THE STEADIER RAIN DEVELOPS...ESP FOR VSBYS. THE STEADY RAIN WILL TAPER TO SHOWERS BY THE MID AFTERNOON HOURS. ALTHOUGH VSBY SHOULD IMPROVE...CIGS MAY REMAIN LOW INTO THE EVENING HOURS. THE COLD/OCCLUDED FRONT SHOULD MOVE ACROSS THE TAF SITES BETWEEN ROUGHLY 22Z/SUN-00Z/MON. A LINE OF HEAVY SHOWERS POSSIBLY ACCOMPANIED BY GUSTY WINDS COULD OCCUR AS THE FRONT MOVES ACROSS. CAN NOT RULE OUT AN ISOLATED THUNDERSTORM AS WELL. IN THE WAKE OF THE FRONT...MAINLY VFR CONDITIONS ARE EXPECTED AFTER 00Z/MON. AS FOR WINDS...EXPECT LIGHT/VARIABLE WINDS TO BECOME MAINLY NE TO E BY SUNRISE AT 5-10 KT. WINDS WILL REMAIN GENERALLY FROM THE E TO NE UNTIL A WARM FRONT MOVES NORTHWARD LATER THIS MORNING INTO EARLY THIS AFTERNOON. THE WARM FRONT IS ONLY EXPECTED TO REACH JUST NORTH OF KALB/KPSF. TO THE SOUTH OF THE FRONT...WINDS WILL SHIFT INTO THE SOUTHEAST TO SOUTH...AND INCREASE TO 10-15 KT WITH GUSTS OF 20-25 LIKELY...POSSIBLY EVEN STRONGER. TO THE NORTH OF THE FRONT...WINDS MAY REMAIN FROM THE E TO NE AT KGFL AT 5-10 KT. AS THE COLD/OCCLUDED FRONT MOVES ACROSS BETWEEN 22Z/SUN- 00Z/MON...WINDS WILL SHIFT INTO THE SOUTHWEST...THEN WEST...AND INCREASE TO 10-15 KT...WITH GUSTS OF AT LEAST 20-30 KT EXPECTED. LOW LEVEL WIND SHEAR HAS BEEN INCLUDED IN THE TAFS FOR MOST SITES BETWEEN ROUGHLY 12Z/SUN AND 18Z-20Z/SUN...GENERALLY NORTH OF THE WARM FRONT AND EAST OF THE COLD/OCCLUDED FRONT. IN THESE AREAS...SFC WINDS WILL REMAIN FROM THE EAST/NORTHEAST AT 10 KT OR LESS...WHILE WINDS AROUND 2000 FT AGL INCREASE FROM THE SOUTHEAST TO 35-45 KT. SUN NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHRA...SHSN. MON: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHSN. MON NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUE: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUE NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. WED: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHSN. WED NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. THU: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... A WIDESPREAD RAINFALL OF ONE HALF INCH TO AN INCH AND A HALF IS EXPECTED WITH SOME LOCALIZED TOTALS OF AROUND TWO INCHES POSSIBLE IN THE EASTERN CATSKILLS AS A STRONG LOW PRESSURE SYSTEM APPROACHES AND MOVES ACROSS THE REGION TONIGHT AND SUNDAY. THE NYS MESONET SITES INDICATED 2 INCH SOIL TEMPERATURES AT OR NEAR THE FREEZING MARK SO RUNOFF POTENTIAL WILL BE HIGH. ALSO A MAJORITY OF THE RAINFALL IS EXPECTED TO OCCUR IN SUNDAY MORNING IN A 6 TO 9 HOUR PERIOD...SO THERE ARE SOME CONCERNS FOR SOME URBAN/POOR DRAINAGE/LOW LYING AREA FLOODING. A SURGE OF VERY MILD AIR WILL ALSO RESULT SOME RUNOFF FROM SNOW MELT. AT THIS TIME...FLOODING IN NOT EXPECTED ON MAIN STEM RIVERS...ALTHOUGH SIGNIFICANT WITHIN BANK RISES ARE EXPECTED. CURRENT FORECASTS HAVE THE HOOSIC RIVER AT WILLIAMSTOWN...THE WALLOOMSAC AT BENNINGTON...THE RONDOUT CREEK AT ROSENDALE AND THE WEST CANADA CREEK AT KAST BRIDGE REACHING/EXCEEDING ACTION STAGE. WHILE...THE HOOSIC RIVER AT EAGLE BRIDGE...THE ESPOUS CREEK AT MOUNT MARION AND THE SACANDAGA RIVER AT HOPE ARE FORECAST TO CREST JUST SHY OF ACTION STAGE. MUCH COLDER AIR WILL FILTER BACK INTO THE REGION SUNDAY NIGHT INTO MONDAY...WITH COLD TEMPERATURES EXPECTED TO PERSIST THROUGH NEXT WEEK. THIS WILL EVENTUALLY ALLOW FOR ICE TO FORM ON BODIES OF WATER. 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. && .CLIMATE... RECORD HIGH TEMPERATURES POSSIBLE TOMORROW...SUNDAY THE 10TH ESPECIALLY AT ALBANY AND POUGHKEEPSIE WITH FORECAST HIGHS IN THE LOWER 40S TO MID 50S. RECORD HIGHS FOR JANUARY 10TH: ALBANY NY: 53 DEGREES 1939 RECORDS DATE BACK TO 1874 GLENS FALLS NY: 49 DEGREES 1972 RECORDS DATE BACK TO 1949 POUGHKEEPSIE NY: 50 DEGREES 1983 RECORDS DATE BACK TO 1949...HOWEVER DATA IS MISSING THROUGH JANUARY 1999 THROUGH JULY 2000. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON EST TODAY FOR NYZ032-033-047-051-054-058-061-063. MA...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON EST TODAY FOR MAZ001-025. VT...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON EST TODAY FOR VTZ013-014. && $$ SYNOPSIS...IAA NEAR TERM...IAA/FRUGIS/11 SHORT TERM...IAA LONG TERM...FRUGIS AVIATION...FRUGIS/KL HYDROLOGY...IAA CLIMATE...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1227 AM EST SUN JAN 10 2016 .SYNOPSIS... A STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE GREAT LAKES REGION SUNDAY BRINGING A WIDESPREAD RAIN TO OUR REGION ALONG WITH STRONG EAST TO SOUTHEAST WINDS AND A SURGE A VERY MILD TEMPERATURES. WITH THE PASSAGE OF THE SYSTEM...A COLDER AND MORE SEASONABLE AIR MASS WILL BE USHERED BACK INTO THE REGION. AS THE COLDER AIR MOVES OVER THE RELATIVELY WARMER WATERS OF LAKE ONTARIO LAKE EFFECT SNOW WILL DEVELOP AND IMPACT THE WESTERN ADIRONDACKS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1225 AM EST...REGIONAL MOSAIC RADAR CONTINUES TO SHOW MAINLY DRY CONDITIONS OVER THE AREA...WITH JUST A FEW SPOTTY SPRINKLES AROUND. TEMPS CONTINUE TO HOLD STEADY IN THE 30S TO LOW 40S OVER MUCH OF THE REGION. A FEW MESONET OBS OVER WESTERN NEW ENGLAND ARE CLOSE TO THE FREEZING MARK...BUT EVERYWHERE ELSE IS ABOVE FREEZING. ANY PRECIP IS VERY LIGHT AND SPOTTY...AND PERHAPS NOT EVEN REACHING THE GROUND. A STRONG LOW PRESSURE SYSTEM WILL BEGIN TO IMPACT THE REGION LATE TONIGHT. STEADY RAIN WILL OVERSPREAD THE AREA FROM SOUTHWEST TO NORTHEAST LATE TONIGHT TOWARDS SUNRISE AS THE SYSTEM`S WARM FRONT APPROACHES AND ITS VERY STRONG LOW LEVEL JET BEGINS TO MOVE INTO THE REGION. THE 03Z 3KM HRRR SUGGEST THIS WON/T BE UNTIL AFTER 11Z FOR FAR SOUTHERN AREAS...AND WON/T REACH THE CAPITAL REGION UNTIL NEARLY 13Z. THE MODEL HAS CONTINUED TO SHOW THIS WITH EACH RUN...SO HAVE SLOWED THE TIMING OF POPS BACK IN OUR GRIDS. EAST TO SOUTHEAST SURFACE WINDS WILL BE ON THE INCREASE ESPECIALLY LATE. THEY ARE EXPECTED TO BE QUITE STRONG BEFORE SUNRISE. A WIND ADVISORY HAS BEEN ISSUED BEGINNING AT 5 AM FOR THE WESTERN ADIRONDACKS...SCHOHARIE COUNTY...THE HELDERBERGS...EASTERN CATSKILLS...NORTHERN AND CENTRAL TACONICS...BERKSHIRES...AND SOUTHERN GREEN MOUNTAINS OF SOUTHERN VERMONT. THE STRONGEST WINDS AND HIGHEST WIND GUSTS ARE EXPECTED IN AREAS WHERE THE LOCAL TERRAIN FUNNELS EAST TO SOUTHEAST FLOW. TEMPS ARE CURRENTLY IN THE MID 30S TO LOW 40S. LOWS WILL BE THIS EVENING...AS THE PERSISTENT SOUTHERLY FLOW SHOULD ALLOW TEMPS TO RISE OVERNIGHT. ALL AREAS WILL BE ABOVE FREEZING BY THE TIME STEADY PRECIP MOVES IN LATE TONIGHT...AND THAT PRECIP SHOULD BE IN THE FORM OF RAIN. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... WIDESPREAD RAINFALL...STRONG EAST-SOUTHEAST WINDS AND VERY MILD WITH SOME RECORD BREAKING TEMPERATURES EXPECTED. THE INTERACTION OF NORTHERN AND SOUTHERN STREAM ENERGY WILL RESULT IN A DEEP/STRONG LOW PRESSURE SYSTEM WHICH WILL MOVE ACROSS THE GREAT LAKES ON SUNDAY. WITH THE SYSTEM PASSING TO OUR NORTH AND WEST WILL BE ON THE WARM SIDE OF THE SYSTEM AND WILL GET A BRIEF SURGE OF VERY MILD AIR INTO THE REGION ON SUNDAY. RECORD HIGH TEMPERATURES ARE FORECAST FOR ALBANY AND POUGHKEEPSIE. REFER TO OUR CLIMATE SECTION FOR DETAILS. THE WIND ADVISORY IS IN EFFECT THROUGH THE MORNING HOURS... NOONTIME...AS THE VERY STRONG LOW LEVEL JET MOVES ACROSS THE REGION. ENSEMBLES INDICATE +3-4 STANDARD DEVIATIONS FOR THE 850 MB WINDS. GUIDANCE SHOWS 30AGL LEVELS WINDS OF 45 TO 55 KNOTS SUNDAY MORNING ACROSS THE AREAS HAVE ISSUED THE WIND ADVISORY FOR. PRECIPITABLE WATER VALUES WILL BE VERY HIGH FOR THIS TIME OF YEAR...2-3 STANDARD DEVIATIONS ABOVE NORMAL. EXPECTING RAINFALL AMOUNTS OF ONE HALF INCH TO AN INCH AND A HALF WITH SOME LOCALIZED TOTALS OF AROUND TWO INCHES POSSIBLE IN THE EASTERN CATSKILLS. THE NYS MESONET SITES INDICATED 2 INCH SOIL TEMPERATURES AT OR NEAR THE FREEZING MARK SO RUNOFF POTENTIAL WILL BE HIGH. ALSO A MAJORITY OF THE RAINFALL IS EXPECTED TO OCCUR IN SUNDAY MORNING IN A 6 TO 9 HOUR PERIOD...SO THERE ARE SOME CONCERNS FOR SOME URBAN/POOR DRAINAGE/LOW LYING AREA FLOODING. A SURGE OF VERY MILD AIR WILL ALSO RESULT SOME RUNOFF FROM SNOW MELT. MAIN STEM RIVER FLOODING IS NOT EXPECTED...REFER TO THE HYDROLOGY SECTION FOR DETAILS. GUIDANCE INDICATES NEGATIVE SHOWALTER VALUES MOVING ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA ON SUNDAY MAINLY IN THE MORNING JUST AHEAD OF THE WARM FRONT. ALSO THE STORM PREDICTION CENTER HAS THE AREA MAINLY SOUTH AND EAST OF THE CAPITAL DISTRICT HIGHLIGHTED FOR GENERAL THUNDER. SO HAVE A SLIGHT CHANCE OF THUNDER MENTIONED. WITH THE PASSAGE OF THE SYSTEM AND ITS COLD FRONT...A COLDER AND MORE SEASONABLE AIRMASS WILL BE USHERED INTO THE REGION ON BRISK AND GUSTY WESTERLY WINDS AS THE STORM CONTINUES TO DEEPEN. THE WESTERLY WINDS WILL STRENGTHEN OVERNIGHT AND SHOULD BE STRONG THROUGH MUCH OF MONDAY. THEY COULD APPROACH WIND ADVISORY CRITERIA WITH GUSTS GREATER THAN 45 MPH. HAVE THREAT HIGHLIGHTED IN OUR HAZARDOUS WEATHER OUTLOOK. AS THIS COLDER AIR MOVES OVER THE RELATIVELY WARMER WATERS OF LAKE ONTARIO LAKE EFFECT SNOW WILL DEVELOP SUNDAY NIGHT AND IMPACT THE WESTERN ADIRONDACKS. BASED ON THE LATEST GUIDANCE ADVISORY TO POSSIBLY WARNING CRITERIA LAKE EFFECT SNOWS ARE POSSIBLE LATE SUNDAY NIGHT INTO MONDAY EVENING ACROSS NORTHERN HERKIMER COUNTY INTO HAMILTON COUNTY. AT THIS TIME...THE MAIN THREAT AREA IS THE NORTHERN HERKIMER COUNTY IN THE VICINITY OF ROUTE 28...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH TO ISSUE A WATCH. HAVE THREAT HIGHLIGHTED IN OUR HAZARDOUS WEATHER OUTLOOK. && .LONG TERM /TUESDAY THROUGH SATURDAY/... A SEASONABLY COLD AIR MASS WILL BE IN PLACE TO START THE EXTENDED PERIOD FOR TUESDAY WITH TEMPS REACHING THE MID 20S TO MID 30S. AT THE SAME TIME...A FAST MOVING CLIPPER SYSTEM WILL BE APPROACHING THE AREA FROM THE GREAT LAKES FOR TUESDAY INTO TUESDAY NIGHT. WITH TEMPS BEING COLD ENOUGH...ANY PRECIP WILL BE IN THE FORM OF SNOW SHOWERS...ALTHOUGH MOISTURE WILL BE QUITE LIMITED WITH THIS SYSTEM. THE BEST FORCING OF THIS SYSTEM LOOKS TO REMAIN NORTH OF THE AREA...SO THE HIGHEST POPS/QPF LOOK TO BE FOR AREAS NORTH OF THE CAPITAL REGION AND ACROSS THE HIGH TERRAIN. MOST PLACES LOOK TO SEE SOME SNOW SHOWERS BY EITHER LATE IN THE DAY TUESDAY OR INTO TUESDAY NIGHT. HOWEVER...MOST VALLEY AREAS WILL ONLY SEE A COATING OF ACCUMULATION...ALTHOUGH A FEW INCHES WILL BE POSSIBLE FOR FAR NORTHERN AND HIGHER ELEVATIONS. LOW TEMPS ON TUES NIGHT WILL FALL INTO THE TEENS TO LOW 20S. THIS CLIPPER STORM WILL HELP DEVELOP A COASTAL LOW OFF THE COAST OF NORTHERN NEW ENGLAND FOR WEDNESDAY...ALTHOUGH THIS SYSTEM WILL BE A BIT TOO FAR AWAY TO HAVE A BIG IMPACT ON OUR WEATHER. HOWEVER...THE UPPER LEVEL TROUGH WILL BE PASSING ACROSS THE AREA FOR WEDNESDAY...SO SOME ADDITIONAL SNOW SHOWERS/FLURRIES WILL BE POSSIBLE...ESP FOR NORTHERN AND HIGH TERRAIN AREAS. TEMPS LOOK TO ONLY REACH THE MID TEENS TO MID 20S...WITH A CHILLY WESTERLY WIND AS WELL. LOWS ONLY WED NIGHT WILL MAINLY BE IN THE TEENS...ALTHOUGH THE THE HIGHEST ELEVATIONS WILL FALL INTO THE SINGLE DIGITS. FOR THE REMAINDER OF THE WORK WEEK...IT WILL STAY FAIRLY COLD...WITH LAKE EFFECT SNOW IMPACTING NORTHERN AND WESTERN AREAS THANKS TO 850 HPA TEMPS OF -17 TO -19 DEGREES C. ALTHOUGH THERE LOOKS TO BE SOME VARIATION IN THE WIND DIRECTION WHICH WILL KEEP THE BANDS MOVING AROUND...SOME ACCUMULATION LOOKS TO OCCUR FOR THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY...AND IT/S POSSIBLE THAT SOME SNOW SHOWERS/FLURRIES REACH AS FAR AS THE SARATOGA AND CAPITAL REGIONS AT TIMES AS WELL. HIGHS ON THURS/FRI LOOK TO ONLY REACH THE 20S...AND OVERNIGHT LOWS WILL MAINLY BE IN THE TEENS. THE LAKE EFFECT LOOKS TO FINALLY END BY THE WEEKEND...AS HIGH PRESSURE APPROACHING THE AREA ALLOWS THE INVERSION HEIGHT TO LOWER. IT LOOKS TO REMAIN SEASONABLY CHILLY THOUGH...WITH HIGHS CONTINUED TO BE ONLY IN THE 20S TO LOW 30S. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... FLYING CONDITIONS ARE GENERALLY MVFR FOR ALL TAF SITES THIS EVENING...AND THIS LOOKS TO CONTINUE THROUGH THE MAJORITY OF THE OVERNIGHT HOURS. BKN-OVC CIGS OF 1-2 KFT WILL BE IN PLACE WITH MAINLY DRY CONDITIONS TONIGHT. S-SE WINDS WILL BE ABOUT 5-10 KTS OVERNIGHT. HOWEVER...AS A STORM SYSTEM APPROACHES THE AREA...A STEADY RAIN WILL MOVE IN FROM SOUTH TO NORTH BY THE LATE NIGHT HOURS AND INTO THE MORNING ON SUNDAY. ACCORDING TO THE 3KM HRRR MODEL...RAIN SHOULD REACH KPOU BY 10Z...KALB/KPSF BY 12Z...AND KGFL BY 13Z. AFTER AN HOUR OR TWO...THE RAIN LOOK TO BECOME HEAVY...AND FLYING CONDITIONS WILL BE IFR...WITH 2SM OR LESS VSBY IN STEADY MODERATE RAIN AND CIGS JUST UNDER 1000 FT. E-SE WINDS WILL INCREASE TO AROUND 10 KTS FOR SUNDAY MORNING. IN ADDITION...LLWS WILL BE AN ISSUE...WITH 2 KFT WINDS OF 50-60 KTS EXPECTED TO BE IN PLACE DURING THE MORNING HOURS. THE STEADY RAIN WILL TAPER TO SHOWERS BY THE MID AFTERNOON HOURS. ALTHOUGH VSBY SHOULD IMPROVE...CIGS MAY CONTINUE TO BE LOW INTO THE EVENING HOURS. WINDS WILL GRADUALLY SWITCH TO S-SW AROUND 5-10 KTS...AND FLYING CONDITIONS SHOULD IMPROVE TO MVFR. SUN NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHRA...SHSN. MON: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHSN. MON NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. TUE: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUE NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. WED: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHSN. WED NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. THU: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... A WIDESPREAD RAINFALL OF ONE HALF INCH TO AN INCH AND A HALF IS EXPECTED WITH SOME LOCALIZED TOTALS OF AROUND TWO INCHES POSSIBLE IN THE EASTERN CATSKILLS AS A STRONG LOW PRESSURE SYSTEM APPROACHES AND MOVES ACROSS THE REGION TONIGHT AND SUNDAY. THE NYS MESONET SITES INDICATED 2 INCH SOIL TEMPERATURES AT OR NEAR THE FREEZING MARK SO RUNOFF POTENTIAL WILL BE HIGH. ALSO A MAJORITY OF THE RAINFALL IS EXPECTED TO OCCUR IN SUNDAY MORNING IN A 6 TO 9 HOUR PERIOD...SO THERE ARE SOME CONCERNS FOR SOME URBAN/POOR DRAINAGE/LOW LYING AREA FLOODING. A SURGE OF VERY MILD AIR WILL ALSO RESULT SOME RUNOFF FROM SNOW MELT. AT THIS TIME...FLOODING IN NOT EXPECTED ON MAIN STEM RIVERS...ALTHOUGH SIGNIFICANT WITHIN BANK RISES ARE EXPECTED. CURRENT FORECASTS HAVE THE HOOSIC RIVER AT WILLIAMSTOWN...THE WALLOOMSAC AT BENNINGTON...THE RONDOUT CREEK AT ROSENDALE AND THE WEST CANADA CREEK AT KAST BRIDGE REACHING/EXCEEDING ACTION STAGE. WHILE...THE HOOSIC RIVER AT EAGLE BRIDGE...THE ESPOUS CREEK AT MOUNT MARION AND THE SACANDAGA RIVER AT HOPE ARE FORECAST TO CREST JUST SHY OF ACTION STAGE. MUCH COLDER AIR WILL FILTER BACK INTO THE REGION SUNDAY NIGHT INTO MONDAY...WITH COLD TEMPERATURES EXPECTED TO PERSIST THROUGH NEXT WEEK. THIS WILL EVENTUALLY ALLOW FOR ICE TO FORM ON BODIES OF WATER. 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. && .CLIMATE... RECORD HIGH TEMPERATURES POSSIBLE TOMORROW...SUNDAY THE 10TH ESPECIALLY AT ALBANY AND POUGHKEEPSIE WITH FORECAST HIGHS IN THE LOWER 40S TO MID 50S. RECORD HIGHS FOR JANUARY 10TH: ALBANY NY: 53 DEGREES 1939 RECORDS DATE BACK TO 1874 GLENS FALLS NY: 49 DEGREES 1972 RECORDS DATE BACK TO 1949 POUGHKEEPSIE NY: 50 DEGREES 1983 RECORDS DATE BACK TO 1949...HOWEVER DATA IS MISSING THROUGH JANUARY 1999 THROUGH JULY 2000. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON EST TODAY FOR NYZ032-033-047-051-054-058-061-063. MA...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON EST TODAY FOR MAZ001-025. VT...WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON EST TODAY FOR VTZ013-014. && $$ SYNOPSIS...IAA NEAR TERM...IAA/FRUGIS/11 SHORT TERM...IAA LONG TERM...FRUGIS AVIATION...FRUGIS HYDROLOGY...IAA CLIMATE...
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1052 PM EST MON JAN 11 2016 .UPDATE 2... QUICK UPDATE TO RAISE POPS TO A LITTLE BIT OVER THE SOUTHERN AREAS OF SOUTH FLORIDA FOR REST OF TONIGHT...AS THE LATEST SHORT RANGE MODELS ARE SHOWING THE RAINS TO CONTINUE THROUGH THE OVERNIGHT HOURS ESPECIALLY SOUTH OF ALLIGATOR ALLEY. && .UPDATE...54/BNB .PREV DISCUSSION... /ISSUED 702 PM EST MON JAN 11 2016/ UPDATE... LATEST HRRR AND LOCAL MODELS IN GOOD AGREEMENT NOW, SPREADING MORE NUMEROUS SHOWERS ACROSS MAINLAND MONROE/MIAMI-DADE COUNTIES A FEW HRS FASTER. THUS, INC POPS A BIT FOR TONIGHT AND TOMORROW MORNING. && PREV DISCUSSION... /ISSUED 657 PM EST MON JAN 11 2016/ AVIATION... BOUNDARY MOISTURE ACROSS THE FLORIDA STRAITS IS EXPECTED TO CONTINUE LIFTING NORTHWARD THIS EVENING AND OVER NIGHT. WITH NORTH TO NORTH NORTHWESTERLY SURFACE WINDS ACROSS THE REGION..THIS WILL RESULT IN OVER-RUNNING ACROSS THE BOUNDARY WITH A CHANCE OF LIGHT SHOWERS AFFECTING THE TERMINALS FROM TIME TO TIME. WHILE VFR CONDITIONS WILL PREVAIL...BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE WITH OCCURRENCE OF SHOWERS AND OCCASIONAL LOWERING OF THE STRATOCUMULUS THAT WILL KEEP STREAMING ACROSS THE REGION. WIND FORECAST IS A CHALLENGE IN THAT WINDS ARE EXPECTED TO OSCILLATE BETWEEN NORTH NORTHWEST AND NORTH NORTHEAST THIS EVENING THROUGH THE EARLY MORNING HOURS ON TUESDAY. && 60 PREV DISCUSSION... /ISSUED 415 PM EST MON JAN 11 2016/ SHORT TERM (TONIGHT-WED NIGHT)... INTO TONIGHT, AS A WEAK DISTURBANCE RIDES SW TO NE FROM CUBA TO THE BAHAMAS, ALONG THE STALLED BOUNDARY, MOISTURE WILL GRADUALLY INCREASE. SUBTLE OVERRUNNING/ISENTROPIC LIFT MAY SHOVE SOME SHOWERS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA LATE TONIGHT. THE ECMWF CONTINUES TO BE WETTER AND MORE AGGRESSIVE INTO TUESDAY, THAN THE REST OF THE MODEL SUITE. 15Z SREF 3HR PRECIP PROBS SEEM TO MATCH THE 12Z GFS DEPICTION FAIRLY WELL WITH MORE PERSISTENT SHOWERS SHIFTED SOUTH. BLENDED POPS HAVE BEGUN TO SHIFT TOWARDS THIS CONSENSUS, BUT CONFIDENCE REGARDING HOW FAR NORTH THE PERSISTENT SHOWERS REACH IS BELOW AVG. HIGH CHC POPS ARE IN THE FORECAST FOR THE SOUTHERN QUARTER OF THE CWA DURING THE FIRST HALF OF TOMORROW. ANOTHER SHOT OF COOLER AND DRIER AIR ARRIVES TUESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN STATES BEHIND ANOTHER STRONG COLD FRONT THROUGH THE MIDDLE ATLANTIC. MIN TEMPS ARE FORECASTED INTO THE MIDDLE 40S ACROSS THE INTERIOR NORTHWEST. MIDDLE TO UPPER 50S ARE POSSIBLE EVEN INTO CITIES OF EXTREME SE FL. SURFACE HIGH PRESSURE CENTERED OVER NORTHERN FL FOR MUCH OF WEDNESDAY PROVIDES ANOTHER DRY DAY WITH MAX T AROUND 70F FOR MUCH OF THE REGION. ALTHOUGH SOME CLOUDS ARE EXPECTED TO ARRIVE WEDNESDAY NIGHT AS HIGH PRESSURE SLOWLY SLIPS EAST, TEMPS COULD BE COOLER THAN FORECAST IF MOISTURE RETURN IS SLOWER. LONG TERM (THU-SUN NIGHT)... DEVELOPMENT AND MOVEMENT OF LOW PRESSURE ACROSS THE GULF OF MEXICO, WHICH EVENTUALLY IMPACTS FL, IS SLOWER THAN PREVIOUS MODEL CYCLES. THUS, PRECIP HAS BEEN DELAYED SOMEWHAT INTO THURSDAY. THE GFS IS MUCH FASTER, IN CONTRAST TO THE 12Z ECMWF WHICH HAS LITTLE IF ANY PRECIP BETWEEN 12Z THURS-0Z FRIDAY. MADE SOME ADJUSTMENTS TO THE POP BLENDS FOR THIS DAY CONSIDERING. THERE SEEMS TO BE BETTER AGREEMENT ON LATE THURS NIGHT/FRIDAY BEING THE DAY IN WHICH LOW PRESSURE AND A WARM FRONT CROSSES THE WEST COAST OF FL, WHICH COULD RESULT IN SHOWERS AND THUNDERSTORMS INCOMING FORM THE GULF. WATCHING THE OPERATIONAL GFS OVER THE PAST FEW DAYS, IT DOES SEEM TO BE SUFFERING FROM CONVECTIVE FEEDBACK/QPF BULLSEYES, WHICH PUTS INTO QUESTION ITS EVENTUAL TRACK/PLACEMENT/STRENGTH OF LOW PRESSURE. THE ECMWF HAS BEEN SHIFTING SOME OF THE STRONGER FEATURES NORTH. HOWEVER, THE PRESENCE OF A STRONG UPPER JET STREAK CUTTING THROUGH THE GULF ALONG WITH FORECASTED WIND FIELDS CANNOT BE IGNORED. THIS SETUP FOR A FEW STRONGER THUNDERSTORMS REMAINS SOMETHING TO KEEP AN EYE FOR ALL OF SOUTH FL AT THE END OF THE WORK WEEK. A COLD FRONT CROSSING SOUTH FL LATE WEEKEND COULD DELIVER ANOTHER COOLER/DRIER AIRMASS IN TIME FOR EARLY NEXT WEEK. MARINE... A SMALL NORTHEAST SWELL WILL CONTINUE TO AFFECT THE WATERS OFF OF PALM BEACH COUNTY OVER THE NEXT FEW DAYS. MOISTURE RETURNING TO THE REGION MAY PUSH SOME SHOWERS THROUGH THE ATLANTIC WATERS OFF OF MIAMI-DADE LATER TONIGHT AND TOMORROW. NORTHERLY WINDS INCREASE TO AROUND 15 KTS AGAIN TOMORROW NIGHT, WHICH WILL ALSO ALLOW SOME WAVES NEAR 6 FT ALONG THE GULF STREAM INTO WEDNESDAY, ESPECIALLY OFF PALM BEACH COUNTY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 55 72 50 71 / 30 30 0 10 FORT LAUDERDALE 59 70 54 71 / 50 50 0 10 MIAMI 58 71 54 73 / 60 60 10 10 NAPLES 53 68 48 70 / 30 10 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...54/BNB LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS MIAMI FL
702 PM EST MON JAN 11 2016 .UPDATE... LATEST HRRR AND LOCAL MODELS IN GOOD AGREEMENT NOW, SPREADING MORE NUMEROUS SHOWERS ACROSS MAINLAND MONROE/MIAMI-DADE COUNTIES A FEW HRS FASTER. THUS, INC POPS A BIT FOR TONIGHT AND TOMORROW MORNING. && .PREV DISCUSSION... /ISSUED 657 PM EST MON JAN 11 2016/ AVIATION... BOUNDARY MOISTURE ACROSS THE FLORIDA STRAITS IS EXPECTED TO CONTINUE LIFTING NORTHWARD THIS EVENING AND OVER NIGHT. WITH NORTH TO NORTH NORTHWESTERLY SURFACE WINDS ACROSS THE REGION..THIS WILL RESULT IN OVER-RUNNING ACROSS THE BOUNDARY WITH A CHANCE OF LIGHT SHOWERS AFFECTING THE TERMINALS FROM TIME TO TIME. WHILE VFR CONDITIONS WILL PREVAIL...BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE WITH OCCURRENCE OF SHOWERS AND OCCASIONAL LOWERING OF THE STRATOCUMULUS THAT WILL KEEP STREAMING ACROSS THE REGION. WIND FORECAST IS A CHALLENGE IN THAT WINDS ARE EXPECTED TO OSCILLATE BETWEEN NORTH NORTHWEST AND NORTH NORTHEAST THIS EVENING THROUGH THE EARLY MORNING HOURS ON TUESDAY. 60 PREV DISCUSSION... /ISSUED 415 PM EST MON JAN 11 2016/ SHORT TERM (TONIGHT-WED NIGHT)... INTO TONIGHT, AS A WEAK DISTURBANCE RIDES SW TO NE FROM CUBA TO THE BAHAMAS, ALONG THE STALLED BOUNDARY, MOISTURE WILL GRADUALLY INCREASE. SUBTLE OVERRUNNING/ISENTROPIC LIFT MAY SHOVE SOME SHOWERS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA LATE TONIGHT. THE ECMWF CONTINUES TO BE WETTER AND MORE AGGRESSIVE INTO TUESDAY, THAN THE REST OF THE MODEL SUITE. 15Z SREF 3HR PRECIP PROBS SEEM TO MATCH THE 12Z GFS DEPICTION FAIRLY WELL WITH MORE PERSISTENT SHOWERS SHIFTED SOUTH. BLENDED POPS HAVE BEGUN TO SHIFT TOWARDS THIS CONSENSUS, BUT CONFIDENCE REGARDING HOW FAR NORTH THE PERSISTENT SHOWERS REACH IS BELOW AVG. HIGH CHC POPS ARE IN THE FORECAST FOR THE SOUTHERN QUARTER OF THE CWA DURING THE FIRST HALF OF TOMORROW. ANOTHER SHOT OF COOLER AND DRIER AIR ARRIVES TUESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN STATES BEHIND ANOTHER STRONG COLD FRONT THROUGH THE MIDDLE ATLANTIC. MIN TEMPS ARE FORECASTED INTO THE MIDDLE 40S ACROSS THE INTERIOR NORTHWEST. MIDDLE TO UPPER 50S ARE POSSIBLE EVEN INTO CITIES OF EXTREME SE FL. SURFACE HIGH PRESSURE CENTERED OVER NORTHERN FL FOR MUCH OF WEDNESDAY PROVIDES ANOTHER DRY DAY WITH MAX T AROUND 70F FOR MUCH OF THE REGION. ALTHOUGH SOME CLOUDS ARE EXPECTED TO ARRIVE WEDNESDAY NIGHT AS HIGH PRESSURE SLOWLY SLIPS EAST, TEMPS COULD BE COOLER THAN FORECAST IF MOISTURE RETURN IS SLOWER. LONG TERM (THU-SUN NIGHT)... DEVELOPMENT AND MOVEMENT OF LOW PRESSURE ACROSS THE GULF OF MEXICO, WHICH EVENTUALLY IMPACTS FL, IS SLOWER THAN PREVIOUS MODEL CYCLES. THUS, PRECIP HAS BEEN DELAYED SOMEWHAT INTO THURSDAY. THE GFS IS MUCH FASTER, IN CONTRAST TO THE 12Z ECMWF WHICH HAS LITTLE IF ANY PRECIP BETWEEN 12Z THURS-0Z FRIDAY. MADE SOME ADJUSTMENTS TO THE POP BLENDS FOR THIS DAY CONSIDERING. THERE SEEMS TO BE BETTER AGREEMENT ON LATE THURS NIGHT/FRIDAY BEING THE DAY IN WHICH LOW PRESSURE AND A WARM FRONT CROSSES THE WEST COAST OF FL, WHICH COULD RESULT IN SHOWERS AND THUNDERSTORMS INCOMING FORM THE GULF. WATCHING THE OPERATIONAL GFS OVER THE PAST FEW DAYS, IT DOES SEEM TO BE SUFFERING FROM CONVECTIVE FEEDBACK/QPF BULLSEYES, WHICH PUTS INTO QUESTION ITS EVENTUAL TRACK/PLACEMENT/STRENGTH OF LOW PRESSURE. THE ECMWF HAS BEEN SHIFTING SOME OF THE STRONGER FEATURES NORTH. HOWEVER, THE PRESENCE OF A STRONG UPPER JET STREAK CUTTING THROUGH THE GULF ALONG WITH FORECASTED WIND FIELDS CANNOT BE IGNORED. THIS SETUP FOR A FEW STRONGER THUNDERSTORMS REMAINS SOMETHING TO KEEP AN EYE FOR ALL OF SOUTH FL AT THE END OF THE WORK WEEK. A COLD FRONT CROSSING SOUTH FL LATE WEEKEND COULD DELIVER ANOTHER COOLER/DRIER AIRMASS IN TIME FOR EARLY NEXT WEEK. MARINE... A SMALL NORTHEAST SWELL WILL CONTINUE TO AFFECT THE WATERS OFF OF PALM BEACH COUNTY OVER THE NEXT FEW DAYS. MOISTURE RETURNING TO THE REGION MAY PUSH SOME SHOWERS THROUGH THE ATLANTIC WATERS OFF OF MIAMI-DADE LATER TONIGHT AND TOMORROW. NORTHERLY WINDS INCREASE TO AROUND 15 KTS AGAIN TOMORROW NIGHT, WHICH WILL ALSO ALLOW SOME WAVES NEAR 6 FT ALONG THE GULF STREAM INTO WEDNESDAY, ESPECIALLY OFF PALM BEACH COUNTY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 55 72 50 71 / 20 30 0 10 FORT LAUDERDALE 59 70 54 71 / 40 50 0 10 MIAMI 58 71 54 73 / 60 60 10 10 NAPLES 53 68 48 70 / 20 10 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...21/KM LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS MIAMI FL
655 PM EST MON JAN 11 2016 .UPDATE... LATEST HRRR AND LOCAL MODELS IN GOOD AGREEMENT NOW, SPREADING MORE NUMEROUS SHOWERS ACROSS MAINLAND MONROE/MIAMI-DADE COUNTIES A FEW HRS FASTER. THUS, INC POPS A BIT FOR TONIGHT AND TOMORROW MORNING. && .PREV DISCUSSION... /ISSUED 415 PM EST MON JAN 11 2016/ SHORT TERM (TONIGHT-WED NIGHT)... INTO TONIGHT, AS A WEAK DISTURBANCE RIDES SW TO NE FROM CUBA TO THE BAHAMAS, ALONG THE STALLED BOUNDARY, MOISTURE WILL GRADUALLY INCREASE. SUBTLE OVERRUNNING/ISENTROPIC LIFT MAY SHOVE SOME SHOWERS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA LATE TONIGHT. THE ECMWF CONTINUES TO BE WETTER AND MORE AGGRESSIVE INTO TUESDAY, THAN THE REST OF THE MODEL SUITE. 15Z SREF 3HR PRECIP PROBS SEEM TO MATCH THE 12Z GFS DEPICTION FAIRLY WELL WITH MORE PERSISTENT SHOWERS SHIFTED SOUTH. BLENDED POPS HAVE BEGUN TO SHIFT TOWARDS THIS CONSENSUS, BUT CONFIDENCE REGARDING HOW FAR NORTH THE PERSISTENT SHOWERS REACH IS BELOW AVG. HIGH CHC POPS ARE IN THE FORECAST FOR THE SOUTHERN QUARTER OF THE CWA DURING THE FIRST HALF OF TOMORROW. ANOTHER SHOT OF COOLER AND DRIER AIR ARRIVES TUESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN STATES BEHIND ANOTHER STRONG COLD FRONT THROUGH THE MIDDLE ATLANTIC. MIN TEMPS ARE FORECASTED INTO THE MIDDLE 40S ACROSS THE INTERIOR NORTHWEST. MIDDLE TO UPPER 50S ARE POSSIBLE EVEN INTO CITIES OF EXTREME SE FL. SURFACE HIGH PRESSURE CENTERED OVER NORTHERN FL FOR MUCH OF WEDNESDAY PROVIDES ANOTHER DRY DAY WITH MAX T AROUND 70F FOR MUCH OF THE REGION. ALTHOUGH SOME CLOUDS ARE EXPECTED TO ARRIVE WEDNESDAY NIGHT AS HIGH PRESSURE SLOWLY SLIPS EAST, TEMPS COULD BE COOLER THAN FORECAST IF MOISTURE RETURN IS SLOWER. LONG TERM (THU-SUN NIGHT)... DEVELOPMENT AND MOVEMENT OF LOW PRESSURE ACROSS THE GULF OF MEXICO, WHICH EVENTUALLY IMPACTS FL, IS SLOWER THAN PREVIOUS MODEL CYCLES. THUS, PRECIP HAS BEEN DELAYED SOMEWHAT INTO THURSDAY. THE GFS IS MUCH FASTER, IN CONTRAST TO THE 12Z ECMWF WHICH HAS LITTLE IF ANY PRECIP BETWEEN 12Z THURS-0Z FRIDAY. MADE SOME ADJUSTMENTS TO THE POP BLENDS FOR THIS DAY CONSIDERING. THERE SEEMS TO BE BETTER AGREEMENT ON LATE THURS NIGHT/FRIDAY BEING THE DAY IN WHICH LOW PRESSURE AND A WARM FRONT CROSSES THE WEST COAST OF FL, WHICH COULD RESULT IN SHOWERS AND THUNDERSTORMS INCOMING FORM THE GULF. WATCHING THE OPERATIONAL GFS OVER THE PAST FEW DAYS, IT DOES SEEM TO BE SUFFERING FROM CONVECTIVE FEEDBACK/QPF BULLSEYES, WHICH PUTS INTO QUESTION ITS EVENTUAL TRACK/PLACEMENT/STRENGTH OF LOW PRESSURE. THE ECMWF HAS BEEN SHIFTING SOME OF THE STRONGER FEATURES NORTH. HOWEVER, THE PRESENCE OF A STRONG UPPER JET STREAK CUTTING THROUGH THE GULF ALONG WITH FORECASTED WIND FIELDS CANNOT BE IGNORED. THIS SETUP FOR A FEW STRONGER THUNDERSTORMS REMAINS SOMETHING TO KEEP AN EYE FOR ALL OF SOUTH FL AT THE END OF THE WORK WEEK. A COLD FRONT CROSSING SOUTH FL LATE WEEKEND COULD DELIVER ANOTHER COOLER/DRIER AIRMASS IN TIME FOR EARLY NEXT WEEK. MARINE... A SMALL NORTHEAST SWELL WILL CONTINUE TO AFFECT THE WATERS OFF OF PALM BEACH COUNTY OVER THE NEXT FEW DAYS. MOISTURE RETURNING TO THE REGION MAY PUSH SOME SHOWERS THROUGH THE ATLANTIC WATERS OFF OF MIAMI-DADE LATER TONIGHT AND TOMORROW. NORTHERLY WINDS INCREASE TO AROUND 15 KTS AGAIN TOMORROW NIGHT, WHICH WILL ALSO ALLOW SOME WAVES NEAR 6 FT ALONG THE GULF STREAM INTO WEDNESDAY, ESPECIALLY OFF PALM BEACH COUNTY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 55 72 50 71 / 20 30 0 10 FORT LAUDERDALE 59 70 54 71 / 30 50 0 10 MIAMI 58 71 54 73 / 30 50 10 10 NAPLES 53 68 48 70 / 20 10 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...21/KM LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1000 AM EST SUN JAN 10 2016 .DISCUSSION... .UPDATE...A DEEPENING SFC LOW PRESSURE AREA WILL LIFT NE THROUGH THE ERN GRT LAKES AND HELP DRAG A COLD FRONT ACROSS THE NRN FL PENINSULA THIS MORNING AND THROUGH E CENTRAL FL INTO EARLY EVENING. ACTIVE SUBTROPICAL JET ACROSS THE SE STATES TO 165 KNOTS WILL SHIFT OFF THE SE ATLC COAST TONIGHT AND TAKE MOST OF THE MULTI-LAYERED CLOUDS AWAY FROM THE AREA PAST LATE EVENING. A THIN BAND OF SHOWERS FROM SRN OSCEOLA TO SRN BREVARD WILL MOVE EAST ACROSS OKEECHOBEE COUNTY AND THE TREASURE COAST INTO EARLY TO MID AFTERNOON AND THEN SE OF THE AREA BY SUNSET. CURRENT FCST HAS A LOW THUNDER CHANCE ACROSS FAR SRN AREAS FROM LATE MORNING INTO EARLY AFTERNOON AND WILL CONTINUE WITH LOW CONVECTIVE CHANCES ACROSS SRN AREAS BASED ON HRRR AND RECENT RADAR TRENDS. SHOULD SEE SOME LATE AFTERNOON CLEARING ACROSS NRN AREAS WITH HIGHS RANGING FROM AROUND 70 NORTH TO THE UPPER 70S SOUTH. WNW WINDS WILL BECOME BREEZY AT TIMES THIS AFTERNOON. && .AVIATION...EXPECT SOME LOW SHOWER CHANCES FROM KVRB-KSUA 15Z-19Z BEFORE ACTIVITY PUSHES SE OF THE COAST IN THE LATE AFTERNOON. MVFR CIGS ARE LIFTING THIS MORNING WITH MOST AREAS SEEING VFR CIGS OUTSIDE OF ANY SHOWER ACTIVITY INTO THE AFTERNOON. MAINLY VFR TONIGHT WITH SOME HIGH LEVEL CLOUDINESS STILL AROUND IN SW FLOW ALOFT. && .MARINE...WESTERLY FLOW WILL INCREASE TO 15-20 KNOTS OFFSHORE THIS AFTN WITH A DECREASING SWELL BUT STEEPENING WIND WAVES OFFSHORE. WILL CONTINUE ADVISORY FOR OFFSHORE WATERS WITH FRONT MOVING ACROSS THE WATERS THIS AFTERNOON AND EVENING. PREVIOUS DISCUSSION...FOR TODAY...SW FLOW INCREASING AHEAD OF A COLD FRONT WHICH WILL CROSS THE LOCAL WATERS DURING THE DAY. WINDS WILL SHIFT OUT OF THE W/NW BEHIND THE FRONT. THERE SHOULD BE A TEMPORARY RELAXING OF THE GRADIENT/WINDS AS THE FRONTAL ZONE MOVES THROUGH. BUT WINDS WILL INCREASE OUT THE W/NW BEHIND THE FRONT AND CONTINUE INTO TONIGHT AS HIGH PRESSURE OVER THE DEEP SOUTH BUILDS OVER THE AREA. PRESSURE GRADIENT SUPPORTS 17-2O KNOTS OF SW FLOW AHEAD OF THE FRONT THIS MORNING OFFSHORE...SHIFTING W/NW BEHIND THE FRONT THIS AFTERNOON INTO TONIGHT. HAVE RAISED A SMALL CRAFT ADVISORY FOR THE OFFSHORE WATERS OF VOLUSIA AND BREVARD AS SEAS BUILD BACK TO 7 FT. && .FIRE WEATHER...PREVIOUS DISCUSSION...DRIER AIR WILL BEGIN TO FILTER INTO NORTHERN SECTIONS THIS AFTERNOON BEHIND A STRONG COLD FRONT. ALTHOUGH MIN RH VALUES ARE EXPECTED TO REMAIN ABOVE 40 PERCENT...BREEZY WEST TO NORTHWEST WINDS WILL PRODUCE A FIRE SENSITIVE DAY WITH GOOD TO VERY GOOD DISPERSION. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM. && $$ SHORT TERM/AVIATION...VOLKMER LONG TERM/IMPACT WX....LASCODY
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1240 AM EST SUN JAN 10 2016 .AVIATION... A LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL MOVE EAST FROM THE INTERIOR AREAS OF SOUTH FLORIDA AND THROUGH THE TAF SITES OF KFLL...KFXE...KMIA...KOPF...AND KTMB BY 07Z EARLY THIS MORNING. ONCE THE LINE MOVES THROUGH THERE COULD STILL BE SOME SHOWERS AFFECTING THE TAF SITES THROUGH REST OF THE EARLY MORNING HOURS. THEREFORE...VCTS FOR THE ABOVE TAF SITES UNTIL 07Z...THEN VCSH THROUGH REST OF THE EARLY MORNING HOURS. FOR KAPF AND KPBI TAF SITES...VCSH WILL ALSO BE IN PLACE FOR THE EARLY MORNING HOURS. THE SHOWERS WILL CONTINUE INTO THE DAY HOURS TODAY AHEAD OF A COLD FRONT. SO WILL KEEP VCSH IN THE FORECAST FOR ALL OF THE TAF SITES THROUGH 23/00Z. THE WINDS WILL BE SOUTHWEST AROUND 5 KNOTS EARLY THIS MORNING BEFORE INCREASING TO 10 TO 15 KNOTS DURING THE DAY HOURS TODAY. THE WINDS WILL THEN SWING TO A NORTHWEST DIRECTION SUNDAY EVENING BEHIND THE PASSAGE OF THE COLD FRONT. THE CEILING AND VIS SHOULD ALSO REMAIN IN VFR CONDITIONS FOR TODAY OUTSIDE OF ANY SHOWER PASSAGE. && .AVIATION...54/BNB .PREV DISCUSSION... /ISSUED 1151 PM EST SAT JAN 9 2016/ UPDATE... UPDATED TO REFLECT HIGHER POPS SOUTHEAST OF THE BAND OF SHOWERS AND EMBEDDED TSTORMS WHICH STRETCHES FROM COLLIER COUNTY EXTENDING NORTHEAST TO PALM BEACH COUNTY AND THE ADJACENT WATERS. NORTHERN PORTION OF THIS BAND IS WEAKENING BUT THE SOUTHERN PORTION OVER COLLIER HAS NOT. HRRR CONTINUES TO SHOW RAPID WEAKENING AS THIS BAND SAGS ESE, BUT GIVEN RECENT RADAR TRENDS...AM INCLINED TO THINK THIS WILL STAY MORE INTACT THAN SHOWN IN THAT MODEL. FOR THIS REASON, INCREASED POPS FOR THE BROWARD/MIAMI-DADE METRO. MAY HAVE TO GO HIGHER AND WILL WATCH TRENDS OVER THE NEXT HOUR TO SEE. MAIN IMPACT WILL BE HEAVY DOWNPOURS AND A FEW LIGHTNING STRIKES. WILL WATCH CELLS FOR ROTATION BUT SO FAR ANY HAS BEEN BRIEF AND ALOFT. /GREGORIA && PREV DISCUSSION... /ISSUED 942 PM EST SAT JAN 9 2016/ UPDATE... LINE OF SHOWERS, WITH SOME EMBEDDED THUNDERSTORMS, STRETCHES FROM NE PALM BEACH COUNTY ALL THE WAY TO OUR OFFSHORE GULF WATERS. SOME GUSTY WINDS STILL POSSIBLE WITH THE HEAVIER SHOWERS AND A FEW STORMS WITHIN THIS LINE OVER THE NEXT FEW HOURS, BUT ACTIVITY HAS WEAKENED CONSIDERABLY FROM EARLIER THIS EVENING. WEAKENING TREND WILL CONTINUE OVERNIGHT. PATCHY FOG MAY STILL DEVELOP OVER PARTS OF THE INTERIOR BEFORE CLOUDS ARRIVE FROM THE NORTH AND WEST LATER TONIGHT. && PREV DISCUSSION... /ISSUED 659 PM EST SAT JAN 9 2016/ AVIATION... FOR THE SHORT TERM...THERE IS AN ACTIVE AREA OF SHOWERS/THUNDERSTORMS IN THE VICINITY OF REGIONAL SOUTHWEST TRACKING NORTHEAST WITH ADDITIONAL SHOWERS/ISOLATED THUNDERSTORMS IN THE OFF SHORE GULF WATERS. THEREFORE ASSIGNED VCTS FOR TERMINAL KAPF AS AN OUTFLOW BOUNDARY COULD SPAWN SHOWERS/THUNDERSTORMS AT ANY TIME...BRIEF PERIODS OF MVFR OR VERY BRIEF PERIODS OF IFR CONDITIONS ARE POSSIBLE OVER THE NEXT ONE TO TWO HOURS. FOR THE ATLANTIC TERMINALS...WHILE SHOWER ACTIVITY IS POSSIBLE THIS EVENING AND OVER NIGHT...NO THUNDERSTORMS ARE CURRENTLY FORECAST BUT AS THE AFOREMENTIONED LINE OF THUNDERSTORMS MOVES THROUGH SOUTHWEST FLORIDA MAY HAVE TO AMEND AS CONDITIONS WARRANT. OTHERWISE SOUTHWESTERLY WINDS BELOW 10 KNOTS FORECAST THIS EVENING INTO SUNDSAY MORNING AND BRIEF MVFR CONDITIONS ARE POSSIBLE WITH ANY SHOWERS. && 60 PREV DISCUSSION... /ISSUED 344 PM EST SAT JAN 9 2016/ SHORT TERM (TONIGHT-MON NIGHT)... NEAR TERM MODELS INDICATE SHOWERS, AND PERHAPS THUNDERSTORMS, ARRIVING ALONG THE WEST COAST THIS EVENING, AHEAD OF A COLD FRONT MOVING THROUGH THE GULF OF MEXICO OVERNIGHT. SPC HAS EXTENDED THE MARGINAL RISK SOUTH INTO GLADES/HENDRY/COLLIER COUNTIES, AND HAS RECENTLY ISSUED A MESOCALE DISCUSSION ABOUT A STRONGER STORM OR TWO POSSIBLY AFFECTING WESTERN COLLIER/GLADES/HENDRY. THERE REMAINS NOTABLE SHEAR AND LLVL HELICITY IN THESE REGIONS, AND THE 0-1KM HELICITY WAS ABV 100 M2/S2 ON THE 12Z MFL RAOB. ALTHOUGH THE FOCUS FOR ACTIVITY LOOKS TO BE JUST TO THE NORTH OF THE CWA, THIS IS SOMETHING TO MONITOR. CURRENTLY THESE STORMS LOOK FORMIDABLE OVER THE GULF. ACTIVITY WEAKENS SIGNIFICANTLY AND BECOMES JUST SCATTERED SHOWERS IF IT MAKES IT ACROSS THE PENINSULA AND TOUCHES THE EAST COAST LATE. IF CLOUDS AND SHOWERS HOLD OFF ACROSS THE INTERIOR, THERE COULD BE SOME PATCHY FOG AGAIN, HOWEVER LAMP AND SREF PROBS ARE MUCH MORE CONSERVATIVE THAN LAST NIGHT. SUNDAY...SOME SHOWERS WILL BE POSSIBLE ACROSS THE REGION AS THE COLD FRONT MOVES FROM NW TO SE THROUGH THE DAY. POPS WILL REMAIN 30 TO 40 PERCENT INTO THE AFTERNOON. CONSIDERING QPF FOR SUNDAY AFTERNOON, BLEND POPS MAY BE A LITTLE TOO PESSIMISTIC. SURFACE FLOW VEERS TO THE NW LATE DAY. DRIER AIR ARRIVES QUICKLY SUNDAY NIGHT WITH PWATS FALLING FROM 1.5" IN THE AFTERNOON TO BELOW AN INCH. MONDAY...THE DAY STARTS WITH BREEZY NW WINDS AND A MUCH COOLER AND DRIER AIRMASS. DEWPOINTS EVEN FALL INTO THE LOWER 50S WITH MIN TEMPS AROUND 60F EVEN ACROSS THE SOUTHEASTERN PORTION OF THE FORECAST AREA. SURFACE HIGH PRESSURE COVERS MUCH OF THE GULF COAST STATES BY 0Z TUESDAY. MAX T SHOULD STRUGGLE INTO THE LOWER 70S FOR MANY LOCATIONS. SHORT TERM... LONG TERM.... MONDAY NIGHT...AFOREMENTIONED COLD FRONT DRIFTS BACK NORTH ALLOWING ISENTROPIC LIFT/OVERRUNNING TO PRODUCE SCATTERED SHOWERS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA INTO TUESDAY MORNING. PWATS AGAIN MAY RISE ABOVE 1.5" BY 12Z TUESDAY. LONG TERM (TUESDAY-FRIDAY NIGHT)... FOR TUESDAY THE ECMWF IS FURTHER NORTH WITH MORE NUMEROUS SHOWERS THAN THE GFS. REGARDLESS, OVERRUNNING WITH THE BOUNDARY NEARBY IS WORTHY OF HIGH CHC TO LIKELY POPS ACROSS PART OF THE REGION, ESPECIALLY THE SOUTHERN THIRD. COMPARED TO ITS ENSEMBLES THE OPERATIONAL GFS APPEARS TO BE AN OUTLIER WITH REGARDS TO ITS DRIER FORECAST. AS THE EASTERN CONUS TROUGH RELOADS AND DEEPENS, THE BOUNDARY MAY ONCE AGAIN BE FORCED SOUTH INTO THE FL STRAITS TUESDAY NIGHT INTO WEDNESDAY. IN ADDITION, A REINFORCING SHOT OF COOLER/DRIER AIR ARRIVES WITH H85 TEMPS AOB +10C ACROSS THE ENTIRE CWA AND LOW IF ANY POPS. FOR THE END OF NEXT WEEK, THE SUBTROPICAL JET CONTINUES TO BE ACTIVE FROM THE EASTERN PACIFIC INTO THE GULF OF MEXICO, MATCHING WHAT IS TYPICALLY EXPECTED DURING A STRONG EL NINO. BOTH THE GFS/ECMWF ARE IN GOOD AGREEMENT CONCERNING AN AREA OF LOW PRESSURE MOVING ACROSS THE GULF THURSDAY OR FRIDAY. HOWEVER, THE STRENGTH OF THIS SYSTEM IS LARGELY DEPENDING UPON PHASING OF A SHRTWV DROPPING OUT OF THE ROCKIES WEDNESDAY AFTERNOON, AND ANOTHER DARTING ACROSS MEXICO. THE OPERATIONAL GFS IS SPINNING UP A COUPLE OF STRONG AREAS OF LOW PRESSURE LATE THIS WEEK AND INTO THE WEEKEND. THESE FINER DETAILS CAN BE DIFFICULT FOR THE GLOBAL MODELS TO RESOLVE SEVERAL DAYS AWAY. NONETHELESS, THIS PATTERN REMAINS ONE WORTH WATCHING, AS ANY DISTURBANCES DROPPING OUT OF THE MEAN TROUGH ACROSS THE INTERMOUNTAIN WEST COULD INTERACT WITH ENERGY MOVING TOWARDS THE WESTERN GULF OF MEXICO EVEN INTO NEXT WEEKEND. MARINE... A LONG PERIOD NE SWELL WILL CONTINUE TO SLOWLY SUBSIDE ACROSS THE ATLANTIC WATERS. WINDS WILL PICK UP WHILE TURNING NORTHERLY BEHIND A COLD FRONT SUN NIGHT-MON. SHOWERS WILL REDEVELOP OVER THE SOUTHERN ATLANTIC ZONES TUESDAY AS SUNDAY`S COLD FRONT MOVES BACK NORTH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 53 71 57 72 / 10 20 40 60 FORT LAUDERDALE 57 71 60 74 / 10 20 40 60 MIAMI 60 72 61 75 / 10 20 30 60 NAPLES 55 70 54 72 / 10 10 50 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...57/DG LONG TERM....21/KM AVIATION...54/BNB
AREA FORECAST DISCUSSION
NWS MIAMI FL
1151 PM EST SAT JAN 9 2016 .UPDATE... UPDATED TO REFLECT HIGHER POPS SOUTHEAST OF THE BAND OF SHOWERS AND EMBEDDED TSTORMS WHICH STRETCHES FROM COLLIER COUNTY EXTENDING NORTHEAST TO PALM BEACH COUNTY AND THE ADJACENT WATERS. NORTHERN PORTION OF THIS BAND IS WEAKENING BUT THE SOUTHERN PORTION OVER COLLIER HAS NOT. HRRR CONTINUES TO SHOW RAPID WEAKENING AS THIS BAND SAGS ESE, BUT GIVEN RECENT RADAR TRENDS...AM INCLINED TO THINK THIS WILL STAY MORE INTACT THAN SHOWN IN THAT MODEL. FOR THIS REASON, INCREASED POPS FOR THE BROWARD/MIAMI-DADE METRO. MAY HAVE TO GO HIGHER AND WILL WATCH TRENDS OVER THE NEXT HOUR TO SEE. MAIN IMPACT WILL BE HEAVY DOWNPOURS AND A FEW LIGHTNING STRIKES. WILL WATCH CELLS FOR ROTATION BUT SO FAR ANY HAS BEEN BRIEF AND ALOFT. /GREGORIA && .PREV DISCUSSION... /ISSUED 942 PM EST SAT JAN 9 2016/ UPDATE... LINE OF SHOWERS, WITH SOME EMBEDDED THUNDERSTORMS, STRETCHES FROM NE PALM BEACH COUNTY ALL THE WAY TO OUR OFFSHORE GULF WATERS. SOME GUSTY WINDS STILL POSSIBLE WITH THE HEAVIER SHOWERS AND A FEW STORMS WITHIN THIS LINE OVER THE NEXT FEW HOURS, BUT ACTIVITY HAS WEAKENED CONSIDERABLY FROM EARLIER THIS EVENING. WEAKENING TREND WILL CONTINUE OVERNIGHT. PATCHY FOG MAY STILL DEVELOP OVER PARTS OF THE INTERIOR BEFORE CLOUDS ARRIVE FROM THE NORTH AND WEST LATER TONIGHT. PREV DISCUSSION... /ISSUED 659 PM EST SAT JAN 9 2016/ AVIATION... FOR THE SHORT TERM...THERE IS AN ACTIVE AREA OF SHOWERS/THUNDERSTORMS IN THE VICINITY OF REGIONAL SOUTHWEST TRACKING NORTHEAST WITH ADDITIONAL SHOWERS/ISOLATED THUNDERSTORMS IN THE OFF SHORE GULF WATERS. THEREFORE ASSIGNED VCTS FOR TERMINAL KAPF AS AN OUTFLOW BOUNDARY COULD SPAWN SHOWERS/THUNDERSTORMS AT ANY TIME...BRIEF PERIODS OF MVFR OR VERY BRIEF PERIODS OF IFR CONDITIONS ARE POSSIBLE OVER THE NEXT ONE TO TWO HOURS. FOR THE ATLANTIC TERMINALS...WHILE SHOWER ACTIVITY IS POSSIBLE THIS EVENING AND OVER NIGHT...NO THUNDERSTORMS ARE CURRENTLY FORECAST BUT AS THE AFOREMENTIONED LINE OF THUNDERSTORMS MOVES THROUGH SOUTHWEST FLORIDA MAY HAVE TO AMEND AS CONDITIONS WARRANT. OTHERWISE SOUTHWESTERLY WINDS BELOW 10 KNOTS FORECAST THIS EVENING INTO SUNDSAY MORNING AND BRIEF MVFR CONDITIONS ARE POSSIBLE WITH ANY SHOWERS. 60 PREV DISCUSSION... /ISSUED 344 PM EST SAT JAN 9 2016/ SHORT TERM (TONIGHT-MON NIGHT)... NEAR TERM MODELS INDICATE SHOWERS, AND PERHAPS THUNDERSTORMS, ARRIVING ALONG THE WEST COAST THIS EVENING, AHEAD OF A COLD FRONT MOVING THROUGH THE GULF OF MEXICO OVERNIGHT. SPC HAS EXTENDED THE MARGINAL RISK SOUTH INTO GLADES/HENDRY/COLLIER COUNTIES, AND HAS RECENTLY ISSUED A MESOCALE DISCUSSION ABOUT A STRONGER STORM OR TWO POSSIBLY AFFECTING WESTERN COLLIER/GLADES/HENDRY. THERE REMAINS NOTABLE SHEAR AND LLVL HELICITY IN THESE REGIONS, AND THE 0-1KM HELICITY WAS ABV 100 M2/S2 ON THE 12Z MFL RAOB. ALTHOUGH THE FOCUS FOR ACTIVITY LOOKS TO BE JUST TO THE NORTH OF THE CWA, THIS IS SOMETHING TO MONITOR. CURRENTLY THESE STORMS LOOK FORMIDABLE OVER THE GULF. ACTIVITY WEAKENS SIGNIFICANTLY AND BECOMES JUST SCATTERED SHOWERS IF IT MAKES IT ACROSS THE PENINSULA AND TOUCHES THE EAST COAST LATE. IF CLOUDS AND SHOWERS HOLD OFF ACROSS THE INTERIOR, THERE COULD BE SOME PATCHY FOG AGAIN, HOWEVER LAMP AND SREF PROBS ARE MUCH MORE CONSERVATIVE THAN LAST NIGHT. SUNDAY...SOME SHOWERS WILL BE POSSIBLE ACROSS THE REGION AS THE COLD FRONT MOVES FROM NW TO SE THROUGH THE DAY. POPS WILL REMAIN 30 TO 40 PERCENT INTO THE AFTERNOON. CONSIDERING QPF FOR SUNDAY AFTERNOON, BLEND POPS MAY BE A LITTLE TOO PESSIMISTIC. SURFACE FLOW VEERS TO THE NW LATE DAY. DRIER AIR ARRIVES QUICKLY SUNDAY NIGHT WITH PWATS FALLING FROM 1.5" IN THE AFTERNOON TO BELOW AN INCH. MONDAY...THE DAY STARTS WITH BREEZY NW WINDS AND A MUCH COOLER AND DRIER AIRMASS. DEWPOINTS EVEN FALL INTO THE LOWER 50S WITH MIN TEMPS AROUND 60F EVEN ACROSS THE SOUTHEASTERN PORTION OF THE FORECAST AREA. SURFACE HIGH PRESSURE COVERS MUCH OF THE GULF COAST STATES BY 0Z TUESDAY. MAX T SHOULD STRUGGLE INTO THE LOWER 70S FOR MANY LOCATIONS. SHORT TERM... LONG TERM.... MONDAY NIGHT...AFOREMENTIONED COLD FRONT DRIFTS BACK NORTH ALLOWING ISENTROPIC LIFT/OVERRUNNING TO PRODUCE SCATTERED SHOWERS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA INTO TUESDAY MORNING. PWATS AGAIN MAY RISE ABOVE 1.5" BY 12Z TUESDAY. LONG TERM (TUESDAY-FRIDAY NIGHT)... FOR TUESDAY THE ECMWF IS FURTHER NORTH WITH MORE NUMEROUS SHOWERS THAN THE GFS. REGARDLESS, OVERRUNNING WITH THE BOUNDARY NEARBY IS WORTHY OF HIGH CHC TO LIKELY POPS ACROSS PART OF THE REGION, ESPECIALLY THE SOUTHERN THIRD. COMPARED TO ITS ENSEMBLES THE OPERATIONAL GFS APPEARS TO BE AN OUTLIER WITH REGARDS TO ITS DRIER FORECAST. AS THE EASTERN CONUS TROUGH RELOADS AND DEEPENS, THE BOUNDARY MAY ONCE AGAIN BE FORCED SOUTH INTO THE FL STRAITS TUESDAY NIGHT INTO WEDNESDAY. IN ADDITION, A REINFORCING SHOT OF COOLER/DRIER AIR ARRIVES WITH H85 TEMPS AOB +10C ACROSS THE ENTIRE CWA AND LOW IF ANY POPS. FOR THE END OF NEXT WEEK, THE SUBTROPICAL JET CONTINUES TO BE ACTIVE FROM THE EASTERN PACIFIC INTO THE GULF OF MEXICO, MATCHING WHAT IS TYPICALLY EXPECTED DURING A STRONG EL NINO. BOTH THE GFS/ECMWF ARE IN GOOD AGREEMENT CONCERNING AN AREA OF LOW PRESSURE MOVING ACROSS THE GULF THURSDAY OR FRIDAY. HOWEVER, THE STRENGTH OF THIS SYSTEM IS LARGELY DEPENDING UPON PHASING OF A SHRTWV DROPPING OUT OF THE ROCKIES WEDNESDAY AFTERNOON, AND ANOTHER DARTING ACROSS MEXICO. THE OPERATIONAL GFS IS SPINNING UP A COUPLE OF STRONG AREAS OF LOW PRESSURE LATE THIS WEEK AND INTO THE WEEKEND. THESE FINER DETAILS CAN BE DIFFICULT FOR THE GLOBAL MODELS TO RESOLVE SEVERAL DAYS AWAY. NONETHELESS, THIS PATTERN REMAINS ONE WORTH WATCHING, AS ANY DISTURBANCES DROPPING OUT OF THE MEAN TROUGH ACROSS THE INTERMOUNTAIN WEST COULD INTERACT WITH ENERGY MOVING TOWARDS THE WESTERN GULF OF MEXICO EVEN INTO NEXT WEEKEND. MARINE... A LONG PERIOD NE SWELL WILL CONTINUE TO SLOWLY SUBSIDE ACROSS THE ATLANTIC WATERS. WINDS WILL PICK UP WHILE TURNING NORTHERLY BEHIND A COLD FRONT SUN NIGHT-MON. SHOWERS WILL REDEVELOP OVER THE SOUTHERN ATLANTIC ZONES TUESDAY AS SUNDAY`S COLD FRONT MOVES BACK NORTH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 68 82 53 71 / 70 40 10 20 FORT LAUDERDALE 69 82 57 71 / 50 40 10 20 MIAMI 71 82 60 72 / 50 40 10 20 NAPLES 70 76 55 70 / 80 40 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
634 PM CST MON JAN 11 2016 .UPDATE... ISSUED AT 634 PM CST MON JAN 11 2016 Initial short-wave trough is currently passing through north-central Illinois early this evening, with the bulk of the associated precip remaining north of the KILX CWA. While radar is showing light echoes along/east of the I-55 corridor, only a few flurries have been observed thus far. A second more vigorous wave is noted on 00z/6pm water vapor imagery upstream over Minnesota, and think this will be the main snow-maker later tonight. HRRR seems to have a great handle on the situation, so have followed its solution closely. As such, have removed PoPs entire through the evening, opting instead to go with just scattered flurries. Then will bring a period of snow across the area from west to east after midnight as the next wave and associated cold front arrive. Some of this light snow will likely linger into Tuesday morning along/south of I-70. Due to the light nature of the snow and only a 3-4 hour window when snow will be falling, overnight accumulations will remain quite light. Most areas will only see one half inch or less. Main story will be the windy and sharply colder conditions late tonight, as lows drop into the teens and wind-chill readings dip below zero along/north of I-72 toward dawn Tuesday. && .SHORT TERM...(Tonight) ISSUED AT 256 PM CST MON JAN 11 2016 One short wave moving into central MO and eastern IA at mid afternoon will pivot eastward across central IL by early this evening. A stronger northern stream short wave over western MN will dive southeast into northeast IL, northern IN and lower MI by dawn Tue and drive an arctic cold front se across central IL overnight as 1012 mb surface low pressure over ne Iowa deepens to 1000 mb over far eastern lower MI by 12Z/6 am Tue. Brunt of lift and moisture will pass ne of central IL with our area on sw fringe of this deepening storm system. Expect light snow to likely develop and move from nw IL into central IL late this afternoon or evening and then diminish from the west late tonight/early Tue morning, lingering longest over Wabash river valley Tue morning. Snowfall amounts generally around a half inch using a 15-20:1 ratio while areas northeast of I-74 and near the IN border could see half to 1 inch. Lows to be reached Tue morning to range from 10F at Galesburg to 25F at Lawrenceville. Brisk WNW winds of 15-25 mph behind arctic cold front overnight to lower wind chills to zero to 10 below zero from I-72 north late tonight into Tue morning. .LONG TERM...(Tuesday through Monday) ISSUED AT 256 PM CST MON JAN 11 2016 Very chilly conditions are anticipated across central and southeast Illinois into Wednesday in the wake of tonight`s clipper. While the clipper should be mostly east of the area to start the day Tuesday, a few lingering snow showers are possible in far east-central and southeast Illinois. Temperatures on Tuesday will not make it into the 20s across much of the forecast area, and widespread single digit or just below zero overnight lows are likely Tuesday night. Wind Chill values through this period should be single digit or sub- zero more often than not. The upper wave associated with the departing clipper will lift into New England and far eastern Canada by Wednesday. As it departs, the upper-level flow across the forecast area will initially trend more zonal, and eventually southwesterly by Thursday and Friday. This shift in the mean flow will allow temperatures to trend above normal by Thursday and Friday, as troffing reloads across central North America. A system is expected to track into the Midwest within this developing southwesterly flow by late Thursday night into Friday. Consensus now strongly suggests temperatures will moderate enough ahead of this system for the bulk of its associated precipitation to fall in the form of rain. Behind this system the model agreement is less substantial, and confidence in the specific details is low. However, temperatures should plunge below normal once again behind the system, with any remaining precipitation falling as snow. While the trend for the weekend will definitely be colder, how cold it gets and how long the cold lasts is still up for significant debate. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 552 PM CST MON JAN 11 2016 Initial upper-level disturbance is currently tracking across northern Illinois, keeping much of the associated light snow north of the KILX terminals. Second stronger disturbance is noted upstream over Minnesota and will be spreading lower clouds/light snow into the area overnight. HRRR seems to have a good handle on the current situation, so have followed its forecast closely. As such, have removed snow mention this evening in favor of just VCSH at the I-74 terminals. Have then introduced light snow and MVFR ceilings at KPIA by 08z...then further east to KCMI by 10z. The snow will only last 3-4 hours as the system passes, followed by clearing skies Tuesday morning. Winds will initially be from the southwest at less than 10kt this evening, then will veer to the W/NW and increase markedly late tonight into Tuesday as a strong cold front sweeps through the region. Forecast soundings and numeric guidance suggest gusts of 25 to 30kt once the front passes. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Barnes SHORT TERM...07 LONG TERM...BAK AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
552 PM CST MON JAN 11 2016 .SHORT TERM...(Tonight) ISSUED AT 256 PM CST MON JAN 11 2016 One short wave moving into central MO and eastern IA at mid afternoon will pivot eastward across central IL by early this evening. A stronger northern stream short wave over western MN will dive southeast into northeast IL, northern IN and lower MI by dawn Tue and drive an arctic cold front se across central IL overnight as 1012 mb surface low pressure over ne Iowa deepens to 1000 mb over far eastern lower MI by 12Z/6 am Tue. Brunt of lift and moisture will pass ne of central IL with our area on sw fringe of this deepening storm system. Expect light snow to likely develop and move from nw IL into central IL late this afternoon or evening and then diminish from the west late tonight/early Tue morning, lingering longest over Wabash river valley Tue morning. Snowfall amounts generally around a half inch using a 15-20:1 ratio while areas northeast of I-74 and near the IN border could see half to 1 inch. Lows to be reached Tue morning to range from 10F at Galesburg to 25F at Lawrenceville. Brisk WNW winds of 15-25 mph behind arctic cold front overnight to lower wind chills to zero to 10 below zero from I-72 north late tonight into Tue morning. .LONG TERM...(Tuesday through Monday) ISSUED AT 256 PM CST MON JAN 11 2016 Very chilly conditions are anticipated across central and southeast Illinois into Wednesday in the wake of tonight`s clipper. While the clipper should be mostly east of the area to start the day Tuesday, a few lingering snow showers are possible in far east-central and southeast Illinois. Temperatures on Tuesday will not make it into the 20s across much of the forecast area, and widespread single digit or just below zero overnight lows are likely Tuesday night. Wind Chill values through this period should be single digit or sub- zero more often than not. The upper wave associated with the departing clipper will lift into New England and far eastern Canada by Wednesday. As it departs, the upper-level flow across the forecast area will initially trend more zonal, and eventually southwesterly by Thursday and Friday. This shift in the mean flow will allow temperatures to trend above normal by Thursday and Friday, as troffing reloads across central North America. A system is expected to track into the Midwest within this developing southwesterly flow by late Thursday night into Friday. Consensus now strongly suggests temperatures will moderate enough ahead of this system for the bulk of its associated precipitation to fall in the form of rain. Behind this system the model agreement is less substantial, and confidence in the specific details is low. However, temperatures should plunge below normal once again behind the system, with any remaining precipitation falling as snow. While the trend for the weekend will definitely be colder, how cold it gets and how long the cold lasts is still up for significant debate. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 552 PM CST MON JAN 11 2016 Initial upper-level disturbance is currently tracking across northern Illinois, keeping much of the associated light snow north of the KILX terminals. Second stronger disturbance is noted upstream over Minnesota and will be spreading lower clouds/light snow into the area overnight. HRRR seems to have a good handle on the current situation, so have followed its forecast closely. As such, have removed snow mention this evening in favor of just VCSH at the I-74 terminals. Have then introduced light snow and MVFR ceilings at KPIA by 08z...then further east to KCMI by 10z. The snow will only last 3-4 hours as the system passes, followed by clearing skies Tuesday morning. Winds will initially be from the southwest at less than 10kt this evening, then will veer to the W/NW and increase markedly late tonight into Tuesday as a strong cold front sweeps through the region. Forecast soundings and numeric guidance suggest gusts of 25 to 30kt once the front passes. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...07 LONG TERM...BAK AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1201 PM EST SUN JAN 10 2016 .SYNOPSIS... ISSUED AT 1010 AM EST SUN JAN 10 2016 WINDY CONDITIONS AND MUCH COLDER AIR WILL CONTINUE TO FILTER INTO THE REGION TODAY INTO THIS EVENING AS TEMPERATURES FALL INTO THE 20S AND UPPER TEENS. LAKE EFFECT SNOW SHOWERS WILL ALSO PERSIST WITH LIGHT ACCUMULATIONS POSSIBLE. LOW TEMPERATURES TONIGHT WILL DROP INTO THE SINGLE DIGITS FOR MOST LOCATIONS...WITH WIND CHILLS IN THE SINGLE DIGITS BELOW ZERO. MAINLY DRY AND COLD OTHERWISE TONIGHT INTO MONDAY WITH THE NEXT OPPORTUNITY FOR SNOW ACCUMULATIONS AND GUSTY WINDS MONDAY NIGHT THROUGH TUESDAY NIGHT. && .UPDATE... ISSUED AT 1010 AM EST SUN JAN 10 2016 CANCELLED THE WINTER WX ADV IN FAR NW IN/SW LOWER MI GIVEN LIGHT SNOW AMOUNTS AND PATCHY BLOWING SNOW RELEGATED TO OPEN/RURAL AREAS. STILL EXPECT LAKE EFFECT SNOW SHOWERS THROUGH THE DAY...LIKELY BECOMING MORE BANDED/SCATTERED WITH TIME THIS AFTN/EVE AS DRIER AIR CONTINUES TO FUNNEL IN. OTHERWISE...SNOW SHIELD WITHIN DEFORMATION AXIS ON BACKSIDE OF IMPRESSIVE VORT LIFTING THROUGH CENTRAL OH WILL EXIT OUR NW OH COUNTIES BY 16Z...WITH UNTREATED ROADS LIKELY TO REMAIN SLICK IN SPOTS GIVEN BLOWING SNOW AND TEMPS FALLING INTO THE 20S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 447 AM EST SUN JAN 10 2016 SOUTHERN STREAM SHORT WAVE LIFTING NORTHEAST THROUGH THE OHIO VALLEY THIS MORNING WHILE NORTHERN STREAM WAVE DROPPING IN BEHIND. SFC LOW NOW INTO WEST CENTRAL OHIO AND FINALLY DEEPENING AS IT LIFTS NORTHEAST. SFC TEMPS WERE DROPPING WITH COLD AIR ADVECTION AND RAPID CHANGEOVER TO SNOW ONGOING ACROSS CENTRAL CWA. KIWX 88D DUAL POL ZDR AND CC SHOWS THE RAIN/SNOW LINE NICELY AND CONFIRMED AS THIS FEATURE MOVED THROUGH KIWX. RUC13 THERMAL FIELDS HAVE A DECENT HANDLE ON THIS NOW AND USED FOR TOP DOWN METHOD FOR TIMING CHANGEOVER. STRONG DEFORMATION AREA LIFTING NORTHEAST THROUGH CENTRAL INDIANA AND EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH NW OHIO THIS MORNING. TIMING OF CHANGEOVER TO SNOW IN NE INDIANA AND NW OHIO WILL INTERSECT THIS MOISTURE AND SHOULD SEE SOME ACCUMS IN THIS AREA THROUGH MID MORNING. RUC13 HAS KFWA CHANGING OVER BTWN 09-11Z AND LIMA CHANGING 12-13Z. GROUND IS WET AND WE HAVE ONLY SEEN A LIGHT ACCUMULATION HERE AT IWX WITH SNOWFLAKES MELTING AND COMPACTING. EXPECT SIMILAR TRENDS EAST BUT HIRES GUIDANCE INDICATING A FEW HOURS OF MODERATE SNOWFALL BEFORE PCPN AXIS EXITS. POWT METHOD WITH COMBINATION OF RUC AND WPC QPF YIELDS ACCUMS OF 1 TO 2 INCHES NEAR AND EAST OF I69. THESE ACCUMS WILL VARY DEPENDING ON TIMING OF CHANGEOVER AND SNOWFALL RATES ONCE IT CHANGES. NO HEADLINE PLANNED GIVEN WET NATURE AND AMOUNTS SHORT OF ADVISORY LEVEL. NORTHWEST WINDS WILL BE INCREASING THIS MORNING AS SFC LOW DEEPENS AND GRADIENT TIGHTENS. BUFKIT AND RUC/HRRR INDICATING WINDS JUST UNDER ADVISORY LEVEL BUT COULD SEE A FEW GUSTS APPROACH CRITERIA. OPTED TO NOT ISSUE HEADLINE FOR THIS BUT WILL MENTION IN HWO AND BE MONITORED THIS MORNING FOR POSSIBLE ADVISORY. LAKE EFFECT ALREADY DEVELOPING PER REGIONAL AND KIWX 88D. INVERSION HEIGHTS INITIALLY 5-7KFT WITH DELTA T VALUES IN THE UPPER TEENS THIS MORNING. INVERSION LOWERS TO 3KFT THIS AFTERNOON BUT DELTA T VALUES JUMP TO UPPER 20S AS COLD AIR DEEPENS. HAVE SOME ACCUMS OF 1 TO 3 INCHES IN ADVISORY AREA TODAY AND COUPLED WITH WINDS AND BLOWING SNOW POTENTIAL WILL KEEP HEADLINE GOING FOR CONSISTENCY. LAKE PLUME SHOULD SLOWLY TRANSLATE NORTHEAST LATER TODAY AND BE CONFINED TO MAINLY MICHIGAN COUNTIES TONIGHT. ACCUMS WILL DROP OFF SIGNIFICANTLY BUT SCATTERED LIGHT SNOW SHOWERS EXPECTED WITH TRAJECTORIES AND SHALLOW INSTABILITY. TEMPERATURES WILL CRASH TODAY AS COLD AIR INFILTRATES AND DEEPENS. UPSTREAM TEMPS ACROSS IL AND IA ALREADY IN TEENS AND SINGLE DIGITS AND WE SHOULD SEE THIS TREND HERE AS DAY PROGRESSES. HIGHS HAVE ALREADY OCCURRED OR WILL BE SHORTLY IN THE EAST WITH FALLING TEMPS REST OF DAY. LOWS TONIGHT WILL BE IN SINGLE DIGITS TO LOW TEENS. THIS WILL ALLOW WIND CHILLS TO FALL INTO SINGLE DIGITS TODAY AND BELOW ZERO TONIGHT. && .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 447 AM EST SUN JAN 10 2016 THE CHALLENGES THIS PERIOD INCLUDE TIMING AND SNOWFALL WITH THE NEXT SHORT WAVE TROF AND ASSOCIATED COLD FRONT THAT WILL MOVE ACROSS THE FORECAST AREA MONDAY AND MONDAY NIGHT. ARCTIC AIR WILL BE OVER THE REGION EARLY MONDAY AHEAD OF THIS DEVELOPING CLIPPER TYPE OF SYSTEM. ISENTROPIC LIFT ON THE 285K SURFACE FAVORS SYNOPTIC SNOWFALL LATE MONDAY AND MONDAY NIGHT WITH AMOUNTS OF 1-3 INCHES. IN ADDITION TO THE SYSTEM SNOWFALL...LAKE EFFECT SNOW WILL INCREASE AFTER THIS SYSTEM PASSES EARLY TUESDAY WITH THE HEAVIEST SNOWFALL ACROSS FAR SOUTHWEST LOWER MICHIGAN. WINTER WEATHER HEADLINES ARE LIKELY AT LEAST DURING THE DAY TUESDAY AS STRONG WINDS ACCOMPANY THE LAKE EFFECT SNOW SHOWERS AS THE CLIPPER LOW DEEPENS AND INTENSIFIES. DELTA T VALUES WILL LIKELY SURPASS 25C CAUSING EXTREME INSTABILITY. WINDS WILL BACK WEDNESDAY AS INVERSION HEIGHTS FALL CAUSING THE LAKE EFFECT SNOW SHOWERS TO END. AFTER WEDNESDAY...ENSEMBLE SOLUTIONS SHOW LARGE VARIABILITY IN HANDLING THE OVERALL UPPER AIR PATTERN. BOTH THE GFS AND ECMWF ARE MUCH WARMER FRIDAY WITH HIGHS WELL ABOVE FREEZING. HAVE TRENDED HIGHS WARMER LATE THIS WEEK...AND KEPT A CHANCE FOR SNOW FRIDAY AND SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1154 AM EST SUN JAN 10 2016 SURGE OF COLD AIR OVER RELATIVELY WARMER LAKE MI WATERS WILL CONTINUE TO PRODUCE LAKE EFFECT SNOW SHOWERS...GUSTY WINDS...AND MAINLY MVFR CIGS/VIS THIS AFTERNOON. VISIBILITIES WILL BE SOMEWHAT VARIABLE AND POSSIBLY LOWER INTO IFR BRIEFLY AT KSBN. IMPROVING CONDITIONS ARE THEN ANTICIPATED TONIGHT INTO MONDAY MORNING AS WINDS BACK/DIMINISH ALLOWING LAKE EFFECT SNOW AND RESTRICTIONS TO LIFT NORTH INTO MICHIGAN. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...LAKESHORE FLOOD ADVISORY UNTIL 6 PM CST THIS EVENING FOR INZ003. MI...LAKESHORE FLOOD ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ077. OH...NONE. LM...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ043-046. && $$ UPDATE...STEINWEDEL SYNOPSIS...STEINWEDEL SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...STEINWEDEL VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1024 AM EST SUN JAN 10 2016 .SYNOPSIS... ISSUED AT 1010 AM EST SUN JAN 10 2016 WINDY CONDITIONS AND MUCH COLDER AIR WILL CONTINUE TO FILTER INTO THE REGION TODAY INTO THIS EVENING AS TEMPERATURES FALL INTO THE 20S AND UPPER TEENS. LAKE EFFECT SNOW SHOWERS WILL ALSO PERSIST WITH LIGHT ACCUMULATIONS POSSIBLE. LOW TEMPERATURES TONIGHT WILL DROP INTO THE SINGLE DIGITS FOR MOST LOCATIONS...WITH WIND CHILLS IN THE SINGLE DIGITS BELOW ZERO. MAINLY DRY AND COLD OTHERWISE TONIGHT INTO MONDAY WITH THE NEXT OPPORTUNITY FOR SNOW ACCUMULATIONS AND GUSTY WINDS MONDAY NIGHT THROUGH TUESDAY NIGHT. && .UPDATE... ISSUED AT 1010 AM EST SUN JAN 10 2016 CANCELLED THE WINTER WX ADV IN FAR NW IN/SW LOWER MI GIVEN LIGHT SNOW AMOUNTS AND PATCHY BLOWING SNOW RELEGATED TO OPEN/RURAL AREAS. STILL EXPECT LAKE EFFECT SNOW SHOWERS THROUGH THE DAY...LIKELY BECOMING MORE BANDED/SCATTERED WITH TIME THIS AFTN/EVE AS DRIER AIR CONTINUES TO FUNNEL IN. OTHERWISE...SNOW SHIELD WITHIN DEFORMATION AXIS ON BACKSIDE OF IMPRESSIVE VORT LIFTING THROUGH CENTRAL OH WILL EXIT OUR NW OH COUNTIES BY 16Z...WITH UNTREATED ROADS LIKELY TO REMAIN SLICK IN SPOTS GIVEN BLOWING SNOW AND TEMPS FALLING INTO THE 20S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 447 AM EST SUN JAN 10 2016 SOUTHERN STREAM SHORT WAVE LIFTING NORTHEAST THROUGH THE OHIO VALLEY THIS MORNING WHILE NORTHERN STREAM WAVE DROPPING IN BEHIND. SFC LOW NOW INTO WEST CENTRAL OHIO AND FINALLY DEEPENING AS IT LIFTS NORTHEAST. SFC TEMPS WERE DROPPING WITH COLD AIR ADVECTION AND RAPID CHANGEOVER TO SNOW ONGOING ACROSS CENTRAL CWA. KIWX 88D DUAL POL ZDR AND CC SHOWS THE RAIN/SNOW LINE NICELY AND CONFIRMED AS THIS FEATURE MOVED THROUGH KIWX. RUC13 THERMAL FIELDS HAVE A DECENT HANDLE ON THIS NOW AND USED FOR TOP DOWN METHOD FOR TIMING CHANGEOVER. STRONG DEFORMATION AREA LIFTING NORTHEAST THROUGH CENTRAL INDIANA AND EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH NW OHIO THIS MORNING. TIMING OF CHANGEOVER TO SNOW IN NE INDIANA AND NW OHIO WILL INTERSECT THIS MOISTURE AND SHOULD SEE SOME ACCUMS IN THIS AREA THROUGH MID MORNING. RUC13 HAS KFWA CHANGING OVER BTWN 09-11Z AND LIMA CHANGING 12-13Z. GROUND IS WET AND WE HAVE ONLY SEEN A LIGHT ACCUMULATION HERE AT IWX WITH SNOWFLAKES MELTING AND COMPACTING. EXPECT SIMILAR TRENDS EAST BUT HIRES GUIDANCE INDICATING A FEW HOURS OF MODERATE SNOWFALL BEFORE PCPN AXIS EXITS. POWT METHOD WITH COMBINATION OF RUC AND WPC QPF YIELDS ACCUMS OF 1 TO 2 INCHES NEAR AND EAST OF I69. THESE ACCUMS WILL VARY DEPENDING ON TIMING OF CHANGEOVER AND SNOWFALL RATES ONCE IT CHANGES. NO HEADLINE PLANNED GIVEN WET NATURE AND AMOUNTS SHORT OF ADVISORY LEVEL. NORTHWEST WINDS WILL BE INCREASING THIS MORNING AS SFC LOW DEEPENS AND GRADIENT TIGHTENS. BUFKIT AND RUC/HRRR INDICATING WINDS JUST UNDER ADVISORY LEVEL BUT COULD SEE A FEW GUSTS APPROACH CRITERIA. OPTED TO NOT ISSUE HEADLINE FOR THIS BUT WILL MENTION IN HWO AND BE MONITORED THIS MORNING FOR POSSIBLE ADVISORY. LAKE EFFECT ALREADY DEVELOPING PER REGIONAL AND KIWX 88D. INVERSION HEIGHTS INITIALLY 5-7KFT WITH DELTA T VALUES IN THE UPPER TEENS THIS MORNING. INVERSION LOWERS TO 3KFT THIS AFTERNOON BUT DELTA T VALUES JUMP TO UPPER 20S AS COLD AIR DEEPENS. HAVE SOME ACCUMS OF 1 TO 3 INCHES IN ADVISORY AREA TODAY AND COUPLED WITH WINDS AND BLOWING SNOW POTENTIAL WILL KEEP HEADLINE GOING FOR CONSISTENCY. LAKE PLUME SHOULD SLOWLY TRANSLATE NORTHEAST LATER TODAY AND BE CONFINED TO MAINLY MICHIGAN COUNTIES TONIGHT. ACCUMS WILL DROP OFF SIGNIFICANTLY BUT SCATTERED LIGHT SNOW SHOWERS EXPECTED WITH TRAJECTORIES AND SHALLOW INSTABILITY. TEMPERATURES WILL CRASH TODAY AS COLD AIR INFILTRATES AND DEEPENS. UPSTREAM TEMPS ACROSS IL AND IA ALREADY IN TEENS AND SINGLE DIGITS AND WE SHOULD SEE THIS TREND HERE AS DAY PROGRESSES. HIGHS HAVE ALREADY OCCURRED OR WILL BE SHORTLY IN THE EAST WITH FALLING TEMPS REST OF DAY. LOWS TONIGHT WILL BE IN SINGLE DIGITS TO LOW TEENS. THIS WILL ALLOW WIND CHILLS TO FALL INTO SINGLE DIGITS TODAY AND BELOW ZERO TONIGHT. && .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 447 AM EST SUN JAN 10 2016 THE CHALLENGES THIS PERIOD INCLUDE TIMING AND SNOWFALL WITH THE NEXT SHORT WAVE TROF AND ASSOCIATED COLD FRONT THAT WILL MOVE ACROSS THE FORECAST AREA MONDAY AND MONDAY NIGHT. ARCTIC AIR WILL BE OVER THE REGION EARLY MONDAY AHEAD OF THIS DEVELOPING CLIPPER TYPE OF SYSTEM. ISENTROPIC LIFT ON THE 285K SURFACE FAVORS SYNOPTIC SNOWFALL LATE MONDAY AND MONDAY NIGHT WITH AMOUNTS OF 1-3 INCHES. IN ADDITION TO THE SYSTEM SNOWFALL...LAKE EFFECT SNOW WILL INCREASE AFTER THIS SYSTEM PASSES EARLY TUESDAY WITH THE HEAVIEST SNOWFALL ACROSS FAR SOUTHWEST LOWER MICHIGAN. WINTER WEATHER HEADLINES ARE LIKELY AT LEAST DURING THE DAY TUESDAY AS STRONG WINDS ACCOMPANY THE LAKE EFFECT SNOW SHOWERS AS THE CLIPPER LOW DEEPENS AND INTENSIFIES. DELTA T VALUES WILL LIKELY SURPASS 25C CAUSING EXTREME INSTABILITY. WINDS WILL BACK WEDNESDAY AS INVERSION HEIGHTS FALL CAUSING THE LAKE EFFECT SNOW SHOWERS TO END. AFTER WEDNESDAY...ENSEMBLE SOLUTIONS SHOW LARGE VARIABILITY IN HANDLING THE OVERALL UPPER AIR PATTERN. BOTH THE GFS AND ECMWF ARE MUCH WARMER FRIDAY WITH HIGHS WELL ABOVE FREEZING. HAVE TRENDED HIGHS WARMER LATE THIS WEEK...AND KEPT A CHANCE FOR SNOW FRIDAY AND SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 644 AM EST SUN JAN 10 2016 SNOW WILL DIMINISH SHORTLY AT KFWA BUT SNOW SHOWERS STILL POSSIBLE WITH LAKE EFFECT PLUME. SAME PLUME OVER KSBN AND WILL MEANDER THIS MORNING. CIGS AND VIS WILL BE VARIABLE DEPENDING ON WHERE THESE HIGHER RETURNS MOVE. HAVE TRENDED TAFS UP LATE MORNING TO EARLY AFTERNOON. WINDS CONTINUE TO BACK THIS EVENING AND SHOULD SEE IMPROVING CONDITIONS AT BOTH SITES WITH MAIN LAKE EFFECT INTO MICHIGAN. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...LAKESHORE FLOOD ADVISORY UNTIL 6 PM CST THIS EVENING FOR INZ003. MI...LAKESHORE FLOOD ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ077. OH...NONE. LM...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ043-046. && $$ UPDATE...STEINWEDEL SYNOPSIS...STEINWEDEL 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/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
925 AM EST SUN JAN 10 2016 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 351 AM EST SUN JAN 10 2016 SNOW WILL END LATER THIS MORNING AS STRONG LOW PRESSURE PULLS AWAY TO THE NORTHEAST. SHARPLY COLDER AIR WILL OVERSPREAD THE REGION WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS TONIGHT. AFTER A DRY START MONDAY...A FAST MOVING CLIPPER SYSTEM WILL SWING THROUGH THE LOWER GREAT LAKES WITH ADDITIONAL ACCUMULATING SNOW MONDAY NIGHT AND TUESDAY. A REINFORCING SHOT OF FRIGID AIR WILL FOLLOW BEHIND THIS SYSTEM FOR MIDWEEK BEFORE TEMPERATURES RECOVER TO NEAR NORMAL FOR THE END OF THE WEEK. && .NEAR TERM /TODAY/... ISSUED AT 351 AM EST SUN JAN 10 2016 TRANSITION LINE FROM RAIN TO SNOW CONTINUES TO SHOW UP NICELY ON THE 88D CORRELATION COEFFICIENT PRODUCT...RUNNING FROM NEAR ANDERSON TO SHELBYVILLE AND SEYMOUR AT 08Z. PRECIP TYPE IS ALL SNOW WEST OF THIS LINE AND LOCALLY HEAVY IN SPOTS AS WELL. TEMPS ARE TUMBLING QUICKLY...RANGING FROM THE UPPER 20S IN THE WABASH VALLEY TO UPPER 30S IN EASTERN INDIANA AT 08Z. MAIN ISSUE CONTINUES TO REVOLVE AROUND THE ONGOING SNOW...PROVIDING ADDITIONAL DETAIL OVER THE NEXT FEW HOURS AS IT MOVES EAST ACROSS CENTRAL INDIANA. BAND OF HEAVY SNOW WITH RATES NEAR 1 INCH PER HOUR HAS BEEN STEADILY ROTATING EAST THROUGH THE FORECAST AREA AS THE LOW PRESSURE CONTINUES TO STRENGTHEN JUST WEST OF KCVG. THE HEAVIER SNOW BAND RESIDES UNDER THE DEFORMATION AXIS AND IS GETTING SOME ENHANCEMENT COURTESY OF THE STRONG 850MB TROWAL BEING LIFTED BACK WEST INTO THE EASTERN PART OF THE FORECAST AREA. THESE TWO FEATURES WILL WORK IN TANDEM TO MAINTAIN THE INTENSITY OF THE SNOW BAND OVER THE NEXT 4 TO 5 HOURS AS IT CONTINUES TO SHIFT E/NE. IN ADDITION... POTENTIAL FOR CONVECTIVE ENHANCEMENT AS WELL WITH FAVORABLE EPV RATES ACROSS THE AREA. REPORTS HAVE BEEN SPARSE SO FAR...BUT HAVE SEEN AS MUCH AS 2.5 INCHES IN VINCENNES AS THE SNOW BAND PASSED THROUGH WITH MOST OF THAT FALLING IN ABOUT A 3 HOUR PERIOD. EXPECT SIMILAR AMOUNTS TO FALL AS THE BAND SHIFTS EAST WITH THE POSSIBILITY FOR HIGHER AMOUNTS AS THE TROWAL INTERACTION INCREASES OVER THE EAST HALF OF THE FORECAST AREA. HI-RES GUIDANCE CONTINUES TO LOOK A TAD HIGH WITH TOTALS...BUT STILL FEEL A BROAD SWATH OF 2 TO 4 INCHES LOOKS REASONABLE WITH POTENTIAL FOR LOCALLY HIGHER AMOUNTS IN AN AXIS FROM SOUTHWEST COUNTIES NORTHEAST THROUGH INDY METRO AND SHELBYVILLE... THEN CONTINUING NORTHEAST TOWARDS ANDERSON AND MUNCIE. SHOULD SEE SNOW END FROM WEST TO EAST OVER THE NEXT SEVERAL HOURS WITH THE STEADIER SNOW EAST OF THE FORECAST AREA BY 13-14Z. COULD STILL SEE SOME SNOW SHOWERS LINGERING IN THE WAKE OF THE MORE WIDESPREAD SNOW THROUGH THE REST OF THE MORNING...WITH SOME FLURRIES DURING THE AFTERNOON AS A SECONDARY TRAILING WAVE ALOFT TRACKS THROUGH THE LOWER GREAT LAKES. LOW CLOUDS WILL LINGER FOR MUCH OF THE DAY WITH CLEARING LATE AS COLD HIGH PRESSURE BUILDS IN. BESIDES THE SNOW...THE GUSTY WEST-NORTHWEST WINDS AND FALLING TEMPERATURES WILL CREATE ADDITIONAL ISSUES THROUGHOUT THE DAY...EVEN AFTER MOST OF THE SNOW IS GONE. WITH EXPECTED SNOW COVERED AND ICY ROADS AS TEMPS FALL QUICKLY AND POTENTIAL FOR SOME BLOWING OF SNOW THROUGH THE MORNING WITH GUSTS PEAKING AT 35 TO 40 MPH...WILL MAINTAIN THE WINTER WEATHER ADVISORY FOR MUCH OF THE FORECAST AREA THROUGH 18Z. ONLY EXCEPTION WILL BE OVER THE WABASH VALLEY WHERE LITTLE SNOWFALL FELL. PLAN ON REMOVING THE ADVISORY FROM TERRE HAUTE NORTHEAST THROUGH LAFAYETTE AND FLORA AND POINTS WEST. TEMPS...AS MENTIONED ABOVE...TEMPS WILL ONLY GO DOWN FROM THIS POINT FORWARD AS THE ARCTIC AIRMASS DEEPENS OVER THE AREA. UTILIZED A COMBINATION OF RAP AND NAM HOURLY 2M TEMPS AS A BASE FOR TEMPS THROUGH THE DAY WITH SUBTLE ADJUSTMENTS. EXPECT A STEADY FALL THROUGH THE 20S TODAY WITH MUCH OF THE AREA DOWN INTO THE TEENS BY EARLY EVENING. SUBZERO WIND CHILLS WILL BE POSSIBLE BY LATE DAY. TOOK A LITTLE LONGER...BUT WELCOME TO WINTER. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 351 AM EST SUN JAN 10 2016 FORECAST CHALLENGES FOCUS ON POTENTIAL FOR MORE SNOW MONDAY NIGHT AND TUESDAY AS A CLIPPER MOVES THROUGH THE REGION...AS WELL AS TEMPERATURES THROUGHOUT THE SHORT TERM. SKIES WILL CLEAR TONIGHT AS BROAD HIGH PRESSURE TAKES OVER. WINDS WILL SLACKEN BUT WITH A FRESH SNOW COVER ON THE GROUND FOR MOST...POTENTIAL IS THERE FOR A VERY COLD NIGHT ACROSS CENTRAL INDIANA. THE HIGH PRESSURE WILL DIVE INTO THE LOWER MISSISSIPPI VALLEY MONDAY MORNING THEN MOVE INTO THE SOUTHEAST STATES. WEAK SURFACE RIDGING WILL BRING A CHILLY BUT DRY START TO THE WORK WEEK. THE RIDGING WILL SHIFT EAST QUICKLY THROUGH THE COURSE OF THE DAY...WITH FOCUS IMMEDIATELY TURNING TO A QUICK MOVING CLIPPER SYSTEM WITH TWO WAVES ALOFT SERVING AS A POTENTIAL ONE-TWO PUNCH LATE MONDAY INTO TUESDAY MORNING. THE FIRST WAVE WILL TRACK ACROSS THE FORECAST AREA MONDAY EVENING AS SURFACE LOW PRESSURE ORGANIZES OVER THE GREAT LAKES. EXPECT SNOW SHOWERS TO DEVELOP LATE MONDAY AFTERNOON OVER THE NORTHERN WABASH VALLEY...THEN SPREADING SOUTHEAST MONDAY EVENING AS THIS FEATURE PASSES. THE SECOND AND STRONGER UPPER FEATURE WILL DIVE INTO THE AREA IMMEDIATELY BEHIND THE FIRST OVERNIGHT MONDAY...SERVING TO STRENGTHEN THE SURFACE LOW OVER LOWER MICHIGAN AND SWEEP THE TRAILING COLD FRONT ACROSS THE FORECAST AREA TUESDAY MORNING. THE SECOND WAVE ALOFT ALREADY IS EXHIBITING SEVERAL SIGNS THAT WOULD SUGGEST IT COULD OVERPERFORM IN TERMS OF SNOWFALL ACROSS THE FORECAST AREA. MODEL SOUNDINGS SHOW A SATURATED COLUMN THAT SHOULD AT LEAST FOR A PERIOD OF TIME MAKE IT UP INTO THE DENDRITIC GROWTH ZONE. ADDITIONALLY...SUBTLE INSTABILITY AND STEEP LAPSE RATES THROUGH ABOUT 5KFT STRONGLY SUPPORT POTENTIAL FOR CONVECTIVE ENHANCEMENT AND BANDING. SNOWFALL RATIOS SHOULD ALSO BE HIGHER THAN NORMAL EVEN WITH WEAK WARM ADVECTION OCCURRING AHEAD OF THE WAVE. AT THIS POINT...THINK A 15-20 TO 1 RATIO WOULD BE LIKELY WITH THE POSSIBILITY FOR HIGHER SNOWFALL RATIOS WITHIN ANY BANDS THAT FORM. HAVE RAISED POPS ACROSS THE BOARD MONDAY NIGHT AND EARLY TUESDAY AS A RESULT WITH GROWING CONFIDENCE ON A HIGH IMPACT SYSTEM. STILL A TOUCH EARLY TO BE TALKING ABOUT POTENTIAL SNOWFALL TOTALS...BUT THINK A FEW INCHES CERTAINLY NOT OUT OF THE QUESTION CONSIDERING ABOVE THOUGHTS. IN ADDITION...SHARP COLD ADVECTION AND CONTINUED WEAK INSTABILITY AND STEEPER LAPSE RATES DURING THE DAY TUESDAY WILL LIKELY MAINTAIN SCATTERED CONVECTIVE SNOW SHOWERS WELL INTO THE AFTERNOON WITH POTENTIAL FOR ADDITIONAL LIGHT ACCUMS. SNOW WILL END AND SKIES WILL BECOME MOSTLY CLEAR FOR TUESDAY NIGHT WITH A REINFORCING SHOT OF FRIGID ARCTIC AIR. TEMPS...COMBINATION OF CLEARING SKIES AND SNOW ON THE GROUND SUPPORTS UNDERCUTTING MOS FOR LOWS TONIGHT. EXPECT SINGLE DIGITS FOR MOST OF THE AREA. GENERALLY TRENDED TOWARDS COOLER METMOS FOR MONDAY HIGHS THEN TOOK A MODEL BLEND FOR MONDAY NIGHT AND TUESDAY. COLDEST NIGHT OF THE SEASON EXPECTED TUESDAY NIGHT AS TEMPS TUMBLE WITH A FRESHENED SNOW COVER. COULD SEE SUBZERO LOWS IN SPOTS...AND MIN WIND CHILLS WILL FLIRT WITH ADVISORY CRITERIA AS THEY NEAR -10. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 351 AM EST SUN JAN 10 2016 COLD AIR WILL STILL BE IN PLACE AT THE BEGINNING OF THE LONG TERM PERIOD AS WAVES CONTINUE TO ROTATE AROUND AN UPPER LOW SITUATED OVER NORTHERN ONTARIO. DAYTIME HIGHS ON WEDNESDAY WILL STRUGGLE TO GET OUT OF THE UPPER TEENS AND LOW 20S. THE PATTERN WILL SHIFT BY THURSDAY THOUGH AS FLOW BECOMES SOUTHWESTERLY...RESULTING IN A WEAK WARMING TREND THROUGH THE WEEKEND. MEANWHILE...PRECIPITATION CHANCES WILL BE LOW EARLY IN THE PERIOD WITH JUST SLIGHT CHANCES FOR SNOW SHOWERS ACROSS THE NORTHERN COUNTIES ON WEDNESDAY NIGHT AND THURSDAY MORNING AS A WEAK WAVE MOVES THROUGH THE UPPER FLOW. PRECIPITATION CHANCES WILL BECOME MORE WIDESPREAD THOUGH BY FRIDAY AS A WEAK LOW PRESSURE SYSTEM APPROACHES FROM THE MISSOURI VALLEY. PRECIPITATION WILL GENERALLY BE IN THE FORM OF SNOW ACROSS MOST OF CENTRAL INDIANA...BUT THE SOUTHERN COUNTIES COULD SEE SOME RAIN MIX IN THROUGHOUT THE WEEKEND. && .AVIATION /DISCUSSION FOR THE 10/1500Z KIND TAF UPDATE/... ISSUED AT 925 AM EST SUN JAN 10 2016 MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS. NO OTHER CHANGES ARE NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOWS... SNOW HAS MOVED EAST OF ALL TAF SITES AND CONDITIONS WILL CONTINUE TO IMPROVE THROUGH THE MORNING. VISIBILITIES HAVE ALREADY IMPROVED TO 5SM OR BETTER EVERYWHERE...BUT IFR CEILINGS WILL LINGER THROUGH MID MORNING. AFTER THAT...CONDITIONS WILL IMPROVE TO MVFR CATEGORY THROUGH THE AFTERNOON...AND THEN VFR BY LATE AFTERNOON/EARLY EVENING AS AIR COLUMN BECOMES DRIER. WINDS WILL BE A THREAT OUT OF THE WEST/NORTHWEST THROUGH ENTIRE TAF PERIOD WITH SUSTAINED SPEEDS OF 16 TO 26 KTS...GUSTING UP TO 36 KTS. GUSTS WILL TAPER OFF THIS EVENING...BUT SUSTAINED SPEEDS WILL REMAIN AT 11 TO 15 KTS THROUGH THE END OF TAF PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR INZ030- 031-036>042-045>049-052>057-060>065-067>072. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM...TDUD AVIATION...TDUD/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
649 AM EST SUN JAN 10 2016 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 351 AM EST SUN JAN 10 2016 SNOW WILL END LATER THIS MORNING AS STRONG LOW PRESSURE PULLS AWAY TO THE NORTHEAST. SHARPLY COLDER AIR WILL OVERSPREAD THE REGION WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS TONIGHT. AFTER A DRY START MONDAY...A FAST MOVING CLIPPER SYSTEM WILL SWING THROUGH THE LOWER GREAT LAKES WITH ADDITIONAL ACCUMULATING SNOW MONDAY NIGHT AND TUESDAY. A REINFORCING SHOT OF FRIGID AIR WILL FOLLOW BEHIND THIS SYSTEM FOR MIDWEEK BEFORE TEMPERATURES RECOVER TO NEAR NORMAL FOR THE END OF THE WEEK. && .NEAR TERM /TODAY/... ISSUED AT 351 AM EST SUN JAN 10 2016 TRANSITION LINE FROM RAIN TO SNOW CONTINUES TO SHOW UP NICELY ON THE 88D CORRELATION COEFFICIENT PRODUCT...RUNNING FROM NEAR ANDERSON TO SHELBYVILLE AND SEYMOUR AT 08Z. PRECIP TYPE IS ALL SNOW WEST OF THIS LINE AND LOCALLY HEAVY IN SPOTS AS WELL. TEMPS ARE TUMBLING QUICKLY...RANGING FROM THE UPPER 20S IN THE WABASH VALLEY TO UPPER 30S IN EASTERN INDIANA AT 08Z. MAIN ISSUE CONTINUES TO REVOLVE AROUND THE ONGOING SNOW...PROVIDING ADDITIONAL DETAIL OVER THE NEXT FEW HOURS AS IT MOVES EAST ACROSS CENTRAL INDIANA. BAND OF HEAVY SNOW WITH RATES NEAR 1 INCH PER HOUR HAS BEEN STEADILY ROTATING EAST THROUGH THE FORECAST AREA AS THE LOW PRESSURE CONTINUES TO STRENGTHEN JUST WEST OF KCVG. THE HEAVIER SNOW BAND RESIDES UNDER THE DEFORMATION AXIS AND IS GETTING SOME ENHANCEMENT COURTESY OF THE STRONG 850MB TROWAL BEING LIFTED BACK WEST INTO THE EASTERN PART OF THE FORECAST AREA. THESE TWO FEATURES WILL WORK IN TANDEM TO MAINTAIN THE INTENSITY OF THE SNOW BAND OVER THE NEXT 4 TO 5 HOURS AS IT CONTINUES TO SHIFT E/NE. IN ADDITION... POTENTIAL FOR CONVECTIVE ENHANCEMENT AS WELL WITH FAVORABLE EPV RATES ACROSS THE AREA. REPORTS HAVE BEEN SPARSE SO FAR...BUT HAVE SEEN AS MUCH AS 2.5 INCHES IN VINCENNES AS THE SNOW BAND PASSED THROUGH WITH MOST OF THAT FALLING IN ABOUT A 3 HOUR PERIOD. EXPECT SIMILAR AMOUNTS TO FALL AS THE BAND SHIFTS EAST WITH THE POSSIBILITY FOR HIGHER AMOUNTS AS THE TROWAL INTERACTION INCREASES OVER THE EAST HALF OF THE FORECAST AREA. HI-RES GUIDANCE CONTINUES TO LOOK A TAD HIGH WITH TOTALS...BUT STILL FEEL A BROAD SWATH OF 2 TO 4 INCHES LOOKS REASONABLE WITH POTENTIAL FOR LOCALLY HIGHER AMOUNTS IN AN AXIS FROM SOUTHWEST COUNTIES NORTHEAST THROUGH INDY METRO AND SHELBYVILLE... THEN CONTINUING NORTHEAST TOWARDS ANDERSON AND MUNCIE. SHOULD SEE SNOW END FROM WEST TO EAST OVER THE NEXT SEVERAL HOURS WITH THE STEADIER SNOW EAST OF THE FORECAST AREA BY 13-14Z. COULD STILL SEE SOME SNOW SHOWERS LINGERING IN THE WAKE OF THE MORE WIDESPREAD SNOW THROUGH THE REST OF THE MORNING...WITH SOME FLURRIES DURING THE AFTERNOON AS A SECONDARY TRAILING WAVE ALOFT TRACKS THROUGH THE LOWER GREAT LAKES. LOW CLOUDS WILL LINGER FOR MUCH OF THE DAY WITH CLEARING LATE AS COLD HIGH PRESSURE BUILDS IN. BESIDES THE SNOW...THE GUSTY WEST-NORTHWEST WINDS AND FALLING TEMPERATURES WILL CREATE ADDITIONAL ISSUES THROUGHOUT THE DAY...EVEN AFTER MOST OF THE SNOW IS GONE. WITH EXPECTED SNOW COVERED AND ICY ROADS AS TEMPS FALL QUICKLY AND POTENTIAL FOR SOME BLOWING OF SNOW THROUGH THE MORNING WITH GUSTS PEAKING AT 35 TO 40 MPH...WILL MAINTAIN THE WINTER WEATHER ADVISORY FOR MUCH OF THE FORECAST AREA THROUGH 18Z. ONLY EXCEPTION WILL BE OVER THE WABASH VALLEY WHERE LITTLE SNOWFALL FELL. PLAN ON REMOVING THE ADVISORY FROM TERRE HAUTE NORTHEAST THROUGH LAFAYETTE AND FLORA AND POINTS WEST. TEMPS...AS MENTIONED ABOVE...TEMPS WILL ONLY GO DOWN FROM THIS POINT FORWARD AS THE ARCTIC AIRMASS DEEPENS OVER THE AREA. UTILIZED A COMBINATION OF RAP AND NAM HOURLY 2M TEMPS AS A BASE FOR TEMPS THROUGH THE DAY WITH SUBTLE ADJUSTMENTS. EXPECT A STEADY FALL THROUGH THE 20S TODAY WITH MUCH OF THE AREA DOWN INTO THE TEENS BY EARLY EVENING. SUBZERO WIND CHILLS WILL BE POSSIBLE BY LATE DAY. TOOK A LITTLE LONGER...BUT WELCOME TO WINTER. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 351 AM EST SUN JAN 10 2016 FORECAST CHALLENGES FOCUS ON POTENTIAL FOR MORE SNOW MONDAY NIGHT AND TUESDAY AS A CLIPPER MOVES THROUGH THE REGION...AS WELL AS TEMPERATURES THROUGHOUT THE SHORT TERM. SKIES WILL CLEAR TONIGHT AS BROAD HIGH PRESSURE TAKES OVER. WINDS WILL SLACKEN BUT WITH A FRESH SNOW COVER ON THE GROUND FOR MOST...POTENTIAL IS THERE FOR A VERY COLD NIGHT ACROSS CENTRAL INDIANA. THE HIGH PRESSURE WILL DIVE INTO THE LOWER MISSISSIPPI VALLEY MONDAY MORNING THEN MOVE INTO THE SOUTHEAST STATES. WEAK SURFACE RIDGING WILL BRING A CHILLY BUT DRY START TO THE WORK WEEK. THE RIDGING WILL SHIFT EAST QUICKLY THROUGH THE COURSE OF THE DAY...WITH FOCUS IMMEDIATELY TURNING TO A QUICK MOVING CLIPPER SYSTEM WITH TWO WAVES ALOFT SERVING AS A POTENTIAL ONE-TWO PUNCH LATE MONDAY INTO TUESDAY MORNING. THE FIRST WAVE WILL TRACK ACROSS THE FORECAST AREA MONDAY EVENING AS SURFACE LOW PRESSURE ORGANIZES OVER THE GREAT LAKES. EXPECT SNOW SHOWERS TO DEVELOP LATE MONDAY AFTERNOON OVER THE NORTHERN WABASH VALLEY...THEN SPREADING SOUTHEAST MONDAY EVENING AS THIS FEATURE PASSES. THE SECOND AND STRONGER UPPER FEATURE WILL DIVE INTO THE AREA IMMEDIATELY BEHIND THE FIRST OVERNIGHT MONDAY...SERVING TO STRENGTHEN THE SURFACE LOW OVER LOWER MICHIGAN AND SWEEP THE TRAILING COLD FRONT ACROSS THE FORECAST AREA TUESDAY MORNING. THE SECOND WAVE ALOFT ALREADY IS EXHIBITING SEVERAL SIGNS THAT WOULD SUGGEST IT COULD OVERPERFORM IN TERMS OF SNOWFALL ACROSS THE FORECAST AREA. MODEL SOUNDINGS SHOW A SATURATED COLUMN THAT SHOULD AT LEAST FOR A PERIOD OF TIME MAKE IT UP INTO THE DENDRITIC GROWTH ZONE. ADDITIONALLY...SUBTLE INSTABILITY AND STEEP LAPSE RATES THROUGH ABOUT 5KFT STRONGLY SUPPORT POTENTIAL FOR CONVECTIVE ENHANCEMENT AND BANDING. SNOWFALL RATIOS SHOULD ALSO BE HIGHER THAN NORMAL EVEN WITH WEAK WARM ADVECTION OCCURRING AHEAD OF THE WAVE. AT THIS POINT...THINK A 15-20 TO 1 RATIO WOULD BE LIKELY WITH THE POSSIBILITY FOR HIGHER SNOWFALL RATIOS WITHIN ANY BANDS THAT FORM. HAVE RAISED POPS ACROSS THE BOARD MONDAY NIGHT AND EARLY TUESDAY AS A RESULT WITH GROWING CONFIDENCE ON A HIGH IMPACT SYSTEM. STILL A TOUCH EARLY TO BE TALKING ABOUT POTENTIAL SNOWFALL TOTALS...BUT THINK A FEW INCHES CERTAINLY NOT OUT OF THE QUESTION CONSIDERING ABOVE THOUGHTS. IN ADDITION...SHARP COLD ADVECTION AND CONTINUED WEAK INSTABILITY AND STEEPER LAPSE RATES DURING THE DAY TUESDAY WILL LIKELY MAINTAIN SCATTERED CONVECTIVE SNOW SHOWERS WELL INTO THE AFTERNOON WITH POTENTIAL FOR ADDITIONAL LIGHT ACCUMS. SNOW WILL END AND SKIES WILL BECOME MOSTLY CLEAR FOR TUESDAY NIGHT WITH A REINFORCING SHOT OF FRIGID ARCTIC AIR. TEMPS...COMBINATION OF CLEARING SKIES AND SNOW ON THE GROUND SUPPORTS UNDERCUTTING MOS FOR LOWS TONIGHT. EXPECT SINGLE DIGITS FOR MOST OF THE AREA. GENERALLY TRENDED TOWARDS COOLER METMOS FOR MONDAY HIGHS THEN TOOK A MODEL BLEND FOR MONDAY NIGHT AND TUESDAY. COLDEST NIGHT OF THE SEASON EXPECTED TUESDAY NIGHT AS TEMPS TUMBLE WITH A FRESHENED SNOW COVER. COULD SEE SUBZERO LOWS IN SPOTS...AND MIN WIND CHILLS WILL FLIRT WITH ADVISORY CRITERIA AS THEY NEAR -10. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 351 AM EST SUN JAN 10 2016 COLD AIR WILL STILL BE IN PLACE AT THE BEGINNING OF THE LONG TERM PERIOD AS WAVES CONTINUE TO ROTATE AROUND AN UPPER LOW SITUATED OVER NORTHERN ONTARIO. DAYTIME HIGHS ON WEDNESDAY WILL STRUGGLE TO GET OUT OF THE UPPER TEENS AND LOW 20S. THE PATTERN WILL SHIFT BY THURSDAY THOUGH AS FLOW BECOMES SOUTHWESTERLY...RESULTING IN A WEAK WARMING TREND THROUGH THE WEEKEND. MEANWHILE...PRECIPITATION CHANCES WILL BE LOW EARLY IN THE PERIOD WITH JUST SLIGHT CHANCES FOR SNOW SHOWERS ACROSS THE NORTHERN COUNTIES ON WEDNESDAY NIGHT AND THURSDAY MORNING AS A WEAK WAVE MOVES THROUGH THE UPPER FLOW. PRECIPITATION CHANCES WILL BECOME MORE WIDESPREAD THOUGH BY FRIDAY AS A WEAK LOW PRESSURE SYSTEM APPROACHES FROM THE MISSOURI VALLEY. PRECIPITATION WILL GENERALLY BE IN THE FORM OF SNOW ACROSS MOST OF CENTRAL INDIANA...BUT THE SOUTHERN COUNTIES COULD SEE SOME RAIN MIX IN THROUGHOUT THE WEEKEND. && .AVIATION /DISCUSSION FOR THE 10/1200Z TAF ISSUANCE/... ISSUED AT 636 AM EST SUN JAN 10 2016 SNOW HAS MOVED EAST OF ALL TAF SITES AND CONDITIONS WILL CONTINUE TO IMPROVE THROUGH THE MORNING. VISIBILITIES HAVE ALREADY IMPROVED TO 5SM OR BETTER EVERYWHERE...BUT IFR CEILINGS WILL LINGER THROUGH MID MORNING. AFTER THAT...CONDITIONS WILL IMPROVE TO MVFR CATEGORY THROUGH THE AFTERNOON...AND THEN VFR BY LATE AFTERNOON/EARLY EVENING AS AIR COLUMN BECOMES DRIER. WINDS WILL BE A THREAT OUT OF THE WEST/NORTHWEST THROUGH ENTIRE TAF PERIOD WITH SUSTAINED SPEEDS OF 16 TO 26 KTS...GUSTING UP TO 36 KTS. GUSTS WILL TAPER OFF THIS EVENING...BUT SUSTAINED SPEEDS WILL REMAIN AT 11 TO 15 KTS THROUGH THE END OF TAF PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR INZ030- 031-036>042-045>049-052>057-060>065-067>072. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM...TDUD AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
452 AM EST SUN JAN 10 2016 .SYNOPSIS... ISSUED AT 448 AM EST SUN JAN 10 2016 RAIN WILL TRANSITION TO SNOW ACROSS NORTHEAST INDIANA AND NORTHWEST OHIO THIS MORNING WHILE LAKE EFFECT SNOW SHOWERS INCREASE OVER NORTHWEST INDIANA AND SOUTHWEST LOWER MICHIGAN. IT WILL BE SHARPLY COLDER TODAY AS TEMPERATURES FALL INTO THE TEENS DURING THE DAY WITH NORTHWEST WINDS OF 20 TO 30 MPH. WIND CHILLS WILL FALL INTO THE SINGLE DIGITS THIS AFTERNOON. LOW TEMPERATURES TONIGHT WILL ALSO FALL INTO THE SINGLE DIGITS WHILE WIND CHILLS DROP BELOW ZERO. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 447 AM EST SUN JAN 10 2016 SOUTHERN STREAM SHORT WAVE LIFTING NORTHEAST THROUGH THE OHIO VALLEY THIS MORNING WHILE NORTHERN STREAM WAVE DROPPING IN BEHIND. SFC LOW NOW INTO WEST CENTRAL OHIO AND FINALLY DEEPENING AS IT LIFTS NORTHEAST. SFC TEMPS WERE DROPPING WITH COLD AIR ADVECTION AND RAPID CHANGEOVER TO SNOW ONGOING ACROSS CENTRAL CWA. KIWX 88D DUAL POL ZDR AND CC SHOWS THE RAIN/SNOW LINE NICELY AND CONFIRMED AS THIS FEATURE MOVED THROUGH KIWX. RUC13 THERMAL FIELDS HAVE A DECENT HANDLE ON THIS NOW AND USED FOR TOP DOWN METHOD FOR TIMING CHANGEOVER. STRONG DEFORMATION AREA LIFTING NORTHEAST THROUGH CENTRAL INDIANA AND EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH NW OHIO THIS MORNING. TIMING OF CHANGEOVER TO SNOW IN NE INDIANA AND NW OHIO WILL INTERSECT THIS MOISTURE AND SHOULD SEE SOME ACCUMS IN THIS AREA THROUGH MID MORNING. RUC13 HAS KFWA CHANGING OVER BTWN 09-11Z AND LIMA CHANGING 12-13Z. GROUND IS WET AND WE HAVE ONLY SEEN A LIGHT ACCUMULATION HERE AT IWX WITH SNOWFLAKES MELTING AND COMPACTING. EXPECT SIMILAR TRENDS EAST BUT HIRES GUIDANCE INDICATING A FEW HOURS OF MODERATE SNOWFALL BEFORE PCPN AXIS EXITS. POWT METHOD WITH COMBINATION OF RUC AND WPC QPF YIELDS ACCUMS OF 1 TO 2 INCHES NEAR AND EAST OF I69. THESE ACCUMS WILL VARY DEPENDING ON TIMING OF CHANGEOVER AND SNOWFALL RATES ONCE IT CHANGES. NO HEADLINE PLANNED GIVEN WET NATURE AND AMOUNTS SHORT OF ADVISORY LEVEL. NORTHWEST WINDS WILL BE INCREASING THIS MORNING AS SFC LOW DEEPENS AND GRADIENT TIGHTENS. BUFKIT AND RUC/HRRR INDICATING WINDS JUST UNDER ADVISORY LEVEL BUT COULD SEE A FEW GUSTS APPROACH CRITERIA. OPTED TO NOT ISSUE HEADLINE FOR THIS BUT WILL MENTION IN HWO AND BE MONITORED THIS MORNING FOR POSSIBLE ADVISORY. LAKE EFFECT ALREADY DEVELOPING PER REGIONAL AND KIWX 88D. INVERSION HEIGHTS INITIALLY 5-7KFT WITH DELTA T VALUES IN THE UPPER TEENS THIS MORNING. INVERSION LOWERS TO 3KFT THIS AFTERNOON BUT DELTA T VALUES JUMP TO UPPER 20S AS COLD AIR DEEPENS. HAVE SOME ACCUMS OF 1 TO 3 INCHES IN ADVISORY AREA TODAY AND COUPLED WITH WINDS AND BLOWING SNOW POTENTIAL WILL KEEP HEADLINE GOING FOR CONSISTENCY. LAKE PLUME SHOULD SLOWLY TRANSLATE NORTHEAST LATER TODAY AND BE CONFINED TO MAINLY MICHIGAN COUNTIES TONIGHT. ACCUMS WILL DROP OFF SIGNIFICANTLY BUT SCATTERED LIGHT SNOW SHOWERS EXPECTED WITH TRAJECTORIES AND SHALLOW INSTABILITY. TEMPERATURES WILL CRASH TODAY AS COLD AIR INFILTRATES AND DEEPENS. UPSTREAM TEMPS ACROSS IL AND IA ALREADY IN TEENS AND SINGLE DIGITS AND WE SHOULD SEE THIS TREND HERE AS DAY PROGRESSES. HIGHS HAVE ALREADY OCCURRED OR WILL BE SHORTLY IN THE EAST WITH FALLING TEMPS REST OF DAY. LOWS TONIGHT WILL BE IN SINGLE DIGITS TO LOW TEENS. THIS WILL ALLOW WIND CHILLS TO FALL INTO SINGLE DIGITS TODAY AND BELOW ZERO TONIGHT. && .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 447 AM EST SUN JAN 10 2016 THE CHALLENGES THIS PERIOD INCLUDE TIMING AND SNOWFALL WITH THE NEXT SHORT WAVE TROF AND ASSOCIATED COLD FRONT THAT WILL MOVE ACROSS THE FORECAST AREA MONDAY AND MONDAY NIGHT. ARCTIC AIR WILL BE OVER THE REGION EARLY MONDAY AHEAD OF THIS DEVELOPING CLIPPER TYPE OF SYSTEM. ISENTROPIC LIFT ON THE 285K SURFACE FAVORS SYNOPTIC SNOWFALL LATE MONDAY AND MONDAY NIGHT WITH AMOUNTS OF 1-3 INCHES. IN ADDITION TO THE SYSTEM SNOWFALL...LAKE EFFECT SNOW WILL INCREASE AFTER THIS SYSTEM PASSES EARLY TUESDAY WITH THE HEAVIEST SNOWFALL ACROSS FAR SOUTHWEST LOWER MICHIGAN. WINTER WEATHER HEADLINES ARE LIKELY AT LEAST DURING THE DAY TUESDAY AS STRONG WINDS ACCOMPANY THE LAKE EFFECT SNOW SHOWERS AS THE CLIPPER LOW DEEPENS AND INTENSIFIES. DELTA T VALUES WILL LIKELY SURPASS 25C CAUSING EXTREME INSTABILITY. WINDS WILL BACK WEDNESDAY AS INVERSION HEIGHTS FALL CAUSING THE LAKE EFFECT SNOW SHOWERS TO END. AFTER WEDNESDAY...ENSEMBLE SOLUTIONS SHOW LARGE VARIABILITY IN HANDLING THE OVERALL UPPER AIR PATTERN. BOTH THE GFS AND ECMWF ARE MUCH WARMER FRIDAY WITH HIGHS WELL ABOVE FREEZING. HAVE TRENDED HIGHS WARMER LATE THIS WEEK...AND KEPT A CHANCE FOR SNOW FRIDAY AND SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1233 AM EST SUN JAN 10 2016 RAIN FINALLY STARTING TO CHANGEOVER TO SNOW AT KSBN BUT STRONGER RADAR RETURNS SOUTH AND EAST OF TERMINAL SO NOT EXPECTING ANY VIS RESTRICTIONS UNTIL LAKE EFFECT SNOW PLUME GETS GOING LATER. THIS SHOULD TRANSITION THROUGH THE TERMINAL DURING THE MORNING HOURS BUT WEAKEN AS INVERSION HEIGHTS LOWER MID DAY AND MOISTURE DECREASES. KFWA ABOUT TO SEE INITIAL FRONT AND WIND SHIFT MOVE THROUGH WITH WINDS BECOMING NORTHWEST SHORTLY. RAIN MOVING NORTH WILL KEEP VIS IN THE 2-3 MILE RANGE AND CIGS GENERALLY BLO 1KFT. HIRES GUIDANCE CHANGEOVER TO SNOW LOOKS TO BE 09-11Z WINDOW AT KFWA NOW WITH A FEW HOURS OF SNOW AND ACCUMS UP TO AN INCH OR TWO DEPENDING ON EXACT CHANGEOVER. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR INZ003-004. LAKESHORE FLOOD ADVISORY UNTIL 6 PM CST THIS EVENING FOR INZ003. MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ077- 078. LAKESHORE FLOOD ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ077. OH...NONE. LM...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ043-046. && $$ SYNOPSIS...LASHLEY 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/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
351 AM EST SUN JAN 10 2016 .UPDATE... THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 351 AM EST SUN JAN 10 2016 SNOW WILL END LATER THIS MORNING AS STRONG LOW PRESSURE PULLS AWAY TO THE NORTHEAST. SHARPLY COLDER AIR WILL OVERSPREAD THE REGION WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS TONIGHT. AFTER A DRY START MONDAY...A FAST MOVING CLIPPER SYSTEM WILL SWING THROUGH THE LOWER GREAT LAKES WITH ADDITIONAL ACCUMULATING SNOW MONDAY NIGHT AND TUESDAY. A REINFORCING SHOT OF FRIGID AIR WILL FOLLOW BEHIND THIS SYSTEM FOR MIDWEEK BEFORE TEMPERATURES RECOVER TO NEAR NORMAL FOR THE END OF THE WEEK. && .NEAR TERM /TODAY/... ISSUED AT 351 AM EST SUN JAN 10 2016 TRANSITION LINE FROM RAIN TO SNOW CONTINUES TO SHOW UP NICELY ON THE 88D CORRELATION COEFFICIENT PRODUCT...RUNNING FROM NEAR ANDERSON TO SHELBYVILLE AND SEYMOUR AT 08Z. PRECIP TYPE IS ALL SNOW WEST OF THIS LINE AND LOCALLY HEAVY IN SPOTS AS WELL. TEMPS ARE TUMBLING QUICKLY...RANGING FROM THE UPPER 20S IN THE WABASH VALLEY TO UPPER 30S IN EASTERN INDIANA AT 08Z. MAIN ISSUE CONTINUES TO REVOLVE AROUND THE ONGOING SNOW...PROVIDING ADDITIONAL DETAIL OVER THE NEXT FEW HOURS AS IT MOVES EAST ACROSS CENTRAL INDIANA. BAND OF HEAVY SNOW WITH RATES NEAR 1 INCH PER HOUR HAS BEEN STEADILY ROTATING EAST THROUGH THE FORECAST AREA AS THE LOW PRESSURE CONTINUES TO STRENGTHEN JUST WEST OF KCVG. THE HEAVIER SNOW BAND RESIDES UNDER THE DEFORMATION AXIS AND IS GETTING SOME ENHANCEMENT COURTESY OF THE STRONG 850MB TROWAL BEING LIFTED BACK WEST INTO THE EASTERN PART OF THE FORECAST AREA. THESE TWO FEATURES WILL WORK IN TANDEM TO MAINTAIN THE INTENSITY OF THE SNOW BAND OVER THE NEXT 4 TO 5 HOURS AS IT CONTINUES TO SHIFT E/NE. IN ADDITION... POTENTIAL FOR CONVECTIVE ENHANCEMENT AS WELL WITH FAVORABLE EPV RATES ACROSS THE AREA. REPORTS HAVE BEEN SPARSE SO FAR...BUT HAVE SEEN AS MUCH AS 2.5 INCHES IN VINCENNES AS THE SNOW BAND PASSED THROUGH WITH MOST OF THAT FALLING IN ABOUT A 3 HOUR PERIOD. EXPECT SIMILAR AMOUNTS TO FALL AS THE BAND SHIFTS EAST WITH THE POSSIBILITY FOR HIGHER AMOUNTS AS THE TROWAL INTERACTION INCREASES OVER THE EAST HALF OF THE FORECAST AREA. HI-RES GUIDANCE CONTINUES TO LOOK A TAD HIGH WITH TOTALS...BUT STILL FEEL A BROAD SWATH OF 2 TO 4 INCHES LOOKS REASONABLE WITH POTENTIAL FOR LOCALLY HIGHER AMOUNTS IN AN AXIS FROM SOUTHWEST COUNTIES NORTHEAST THROUGH INDY METRO AND SHELBYVILLE... THEN CONTINUING NORTHEAST TOWARDS ANDERSON AND MUNCIE. SHOULD SEE SNOW END FROM WEST TO EAST OVER THE NEXT SEVERAL HOURS WITH THE STEADIER SNOW EAST OF THE FORECAST AREA BY 13-14Z. COULD STILL SEE SOME SNOW SHOWERS LINGERING IN THE WAKE OF THE MORE WIDESPREAD SNOW THROUGH THE REST OF THE MORNING...WITH SOME FLURRIES DURING THE AFTERNOON AS A SECONDARY TRAILING WAVE ALOFT TRACKS THROUGH THE LOWER GREAT LAKES. LOW CLOUDS WILL LINGER FOR MUCH OF THE DAY WITH CLEARING LATE AS COLD HIGH PRESSURE BUILDS IN. BESIDES THE SNOW...THE GUSTY WEST-NORTHWEST WINDS AND FALLING TEMPERATURES WILL CREATE ADDITIONAL ISSUES THROUGHOUT THE DAY...EVEN AFTER MOST OF THE SNOW IS GONE. WITH EXPECTED SNOW COVERED AND ICY ROADS AS TEMPS FALL QUICKLY AND POTENTIAL FOR SOME BLOWING OF SNOW THROUGH THE MORNING WITH GUSTS PEAKING AT 35 TO 40 MPH...WILL MAINTAIN THE WINTER WEATHER ADVISORY FOR MUCH OF THE FORECAST AREA THROUGH 18Z. ONLY EXCEPTION WILL BE OVER THE WABASH VALLEY WHERE LITTLE SNOWFALL FELL. PLAN ON REMOVING THE ADVISORY FROM TERRE HAUTE NORTHEAST THROUGH LAFAYETTE AND FLORA AND POINTS WEST. TEMPS...AS MENTIONED ABOVE...TEMPS WILL ONLY GO DOWN FROM THIS POINT FORWARD AS THE ARCTIC AIRMASS DEEPENS OVER THE AREA. UTILIZED A COMBINATION OF RAP AND NAM HOURLY 2M TEMPS AS A BASE FOR TEMPS THROUGH THE DAY WITH SUBTLE ADJUSTMENTS. EXPECT A STEADY FALL THROUGH THE 20S TODAY WITH MUCH OF THE AREA DOWN INTO THE TEENS BY EARLY EVENING. SUBZERO WIND CHILLS WILL BE POSSIBLE BY LATE DAY. TOOK A LITTLE LONGER...BUT WELCOME TO WINTER. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 351 AM EST SUN JAN 10 2016 FORECAST CHALLENGES FOCUS ON POTENTIAL FOR MORE SNOW MONDAY NIGHT AND TUESDAY AS A CLIPPER MOVES THROUGH THE REGION...AS WELL AS TEMPERATURES THROUGHOUT THE SHORT TERM. SKIES WILL CLEAR TONIGHT AS BROAD HIGH PRESSURE TAKES OVER. WINDS WILL SLACKEN BUT WITH A FRESH SNOW COVER ON THE GROUND FOR MOST...POTENTIAL IS THERE FOR A VERY COLD NIGHT ACROSS CENTRAL INDIANA. THE HIGH PRESSURE WILL DIVE INTO THE LOWER MISSISSIPPI VALLEY MONDAY MORNING THEN MOVE INTO THE SOUTHEAST STATES. WEAK SURFACE RIDGING WILL BRING A CHILLY BUT DRY START TO THE WORK WEEK. THE RIDGING WILL SHIFT EAST QUICKLY THROUGH THE COURSE OF THE DAY...WITH FOCUS IMMEDIATELY TURNING TO A QUICK MOVING CLIPPER SYSTEM WITH TWO WAVES ALOFT SERVING AS A POTENTIAL ONE-TWO PUNCH LATE MONDAY INTO TUESDAY MORNING. THE FIRST WAVE WILL TRACK ACROSS THE FORECAST AREA MONDAY EVENING AS SURFACE LOW PRESSURE ORGANIZES OVER THE GREAT LAKES. EXPECT SNOW SHOWERS TO DEVELOP LATE MONDAY AFTERNOON OVER THE NORTHERN WABASH VALLEY...THEN SPREADING SOUTHEAST MONDAY EVENING AS THIS FEATURE PASSES. THE SECOND AND STRONGER UPPER FEATURE WILL DIVE INTO THE AREA IMMEDIATELY BEHIND THE FIRST OVERNIGHT MONDAY...SERVING TO STRENGTHEN THE SURFACE LOW OVER LOWER MICHIGAN AND SWEEP THE TRAILING COLD FRONT ACROSS THE FORECAST AREA TUESDAY MORNING. THE SECOND WAVE ALOFT ALREADY IS EXHIBITING SEVERAL SIGNS THAT WOULD SUGGEST IT COULD OVERPERFORM IN TERMS OF SNOWFALL ACROSS THE FORECAST AREA. MODEL SOUNDINGS SHOW A SATURATED COLUMN THAT SHOULD AT LEAST FOR A PERIOD OF TIME MAKE IT UP INTO THE DENDRITIC GROWTH ZONE. ADDITIONALLY...SUBTLE INSTABILITY AND STEEP LAPSE RATES THROUGH ABOUT 5KFT STRONGLY SUPPORT POTENTIAL FOR CONVECTIVE ENHANCEMENT AND BANDING. SNOWFALL RATIOS SHOULD ALSO BE HIGHER THAN NORMAL EVEN WITH WEAK WARM ADVECTION OCCURRING AHEAD OF THE WAVE. AT THIS POINT...THINK A 15-20 TO 1 RATIO WOULD BE LIKELY WITH THE POSSIBILITY FOR HIGHER SNOWFALL RATIOS WITHIN ANY BANDS THAT FORM. HAVE RAISED POPS ACROSS THE BOARD MONDAY NIGHT AND EARLY TUESDAY AS A RESULT WITH GROWING CONFIDENCE ON A HIGH IMPACT SYSTEM. STILL A TOUCH EARLY TO BE TALKING ABOUT POTENTIAL SNOWFALL TOTALS...BUT THINK A FEW INCHES CERTAINLY NOT OUT OF THE QUESTION CONSIDERING ABOVE THOUGHTS. IN ADDITION...SHARP COLD ADVECTION AND CONTINUED WEAK INSTABILITY AND STEEPER LAPSE RATES DURING THE DAY TUESDAY WILL LIKELY MAINTAIN SCATTERED CONVECTIVE SNOW SHOWERS WELL INTO THE AFTERNOON WITH POTENTIAL FOR ADDITIONAL LIGHT ACCUMS. SNOW WILL END AND SKIES WILL BECOME MOSTLY CLEAR FOR TUESDAY NIGHT WITH A REINFORCING SHOT OF FRIGID ARCTIC AIR. TEMPS...COMBINATION OF CLEARING SKIES AND SNOW ON THE GROUND SUPPORTS UNDERCUTTING MOS FOR LOWS TONIGHT. EXPECT SINGLE DIGITS FOR MOST OF THE AREA. GENERALLY TRENDED TOWARDS COOLER METMOS FOR MONDAY HIGHS THEN TOOK A MODEL BLEND FOR MONDAY NIGHT AND TUESDAY. COLDEST NIGHT OF THE SEASON EXPECTED TUESDAY NIGHT AS TEMPS TUMBLE WITH A FRESHENED SNOW COVER. COULD SEE SUBZERO LOWS IN SPOTS...AND MIN WIND CHILLS WILL FLIRT WITH ADVISORY CRITERIA AS THEY NEAR -10. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 351 AM EST SUN JAN 10 2016 COLD AIR WILL STILL BE IN PLACE AT THE BEGINNING OF THE LONG TERM PERIOD AS WAVES CONTINUE TO ROTATE AROUND AN UPPER LOW SITUATED OVER NORTHERN ONTARIO. DAYTIME HIGHS ON WEDNESDAY WILL STRUGGLE TO GET OUT OF THE UPPER TEENS AND LOW 20S. THE PATTERN WILL SHIFT BY THURSDAY THOUGH AS FLOW BECOMES SOUTHWESTERLY...RESULTING IN A WEAK WARMING TREND THROUGH THE WEEKEND. MEANWHILE...PRECIPITATION CHANCES WILL BE LOW EARLY IN THE PERIOD WITH JUST SLIGHT CHANCES FOR SNOW SHOWERS ACROSS THE NORTHERN COUNTIES ON WEDNESDAY NIGHT AND THURSDAY MORNING AS A WEAK WAVE MOVES THROUGH THE UPPER FLOW. PRECIPITATION CHANCES WILL BECOME MORE WIDESPREAD THOUGH BY FRIDAY AS A WEAK LOW PRESSURE SYSTEM APPROACHES FROM THE MISSOURI VALLEY. PRECIPITATION WILL GENERALLY BE IN THE FORM OF SNOW ACROSS MOST OF CENTRAL INDIANA...BUT THE SOUTHERN COUNTIES COULD SEE SOME RAIN MIX IN THROUGHOUT THE WEEKEND. && .AVIATION /DISCUSSION FOR THE 10/0900Z TAF UPDATE/... ISSUED AT 312 AM EST SUN JAN 10 2016 UPDATE... PERIOD OF LIFR CONDITIONS IS ONGOING AT KIND AS HEAVIEST BANDS OF SNOW CURRENTLY MOVE THROUGH THE AREA. PREVIOUS DISCUSSION... SURFACE LOW CURRENTLY NEAR KSDF...WITH SHORT TERM MODELS SUGGESTING THIS LOW WILL PASS OVER SOUTHEAST INDIANA OVERNIGHT. RAIN HAS CHANGED OVER TO SNOW AT KHUF/KLAF AND SHOULD CHANGE OVER TO SNOW AT KIND/KBMG AROUND 100700Z. MODEL DATA SUGGEST AN AREA OF FAIRLY STRONG LIFT ASSOCIATED WITH THE DEFORMATION ZONE...WHICH SHOULD RESULT IN A PERIOD OF LIFR VISIBILITY RESTRICTIONS IN LIGHT TO MODERATE SNOW AT KIND/KBMG. LESS CONFIDENCE IN LIFR RESTRICTIONS IN THE KLAF/KHUF AREAS AS IT APPEARS BEST LIFT MAY REMAIN EAST OF THE THOSE TERMINALS OVERNIGHT. DEFORMATION ZONE SHIFTS RAPIDLY OFF TO THE EAST OF THE TERMINALS AROUND SUNRISE SUNDAY...SO SHOULD SEE CONDITIONS IMPROVE FROM WEST TO EAST BY THAT TIME...WITH CEILINGS SETTLING INTO AN MVFR DECK AROUND 015 LATER IN THE MORNING. PRESSURE GRADIENT TIGHTENS UP QUITE A BIT OVER THE NEXT SEVERAL HOURS AS SURFACE LOW INTENSIFIES. EXPECTING FREQUENT SURFACE GUSTS IN THE 30-35 KT RANGE FROM 300-320 DEGREES TO DEVELOP OVER THE NEXT SEVERAL HOURS. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR INZ030- 031-036>042-045>049-052>057-060>065-067>072. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM...TDUD AVIATION...JAS/TDUD
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1023 AM MST SUN JAN 10 2016 .UPDATE... ISSUED AT 816 AM MST SUN JAN 10 2016 ISSUED UPDATE TO ZONE FORECAST TO REMOVE MENTION OF FOG AND TO ADJUST CLOUD COVER WORDING. LATEST VISIBLE SATELLITE IMAGE SHOWING ONLY FAR E/NE ZONES UNDER MOSTLY CLOUDY/CLOUDY CONDITIONS...BUT SHOULD CLEAR OVER NEXT FEW HOURS. REST OF FORECAST UNCHANGED AT THIS TIME. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 211 AM MST SUN JAN 10 2016 EARLY MORNING WV IMAGERY AND RAP 500 MB ANALYSIS CONTINUES TO SHOW LARGE SCALE TROUGH ACROSS MUCH OF THE US...WITH RIDGING ALONG THE PACIFIC COAST INTO BRITISH COLUMBIA. NORTH-NORTHWEST FLOW IS IN PLACE ACROSS THE PLAINS WITH MAIN UPPER LEVEL JETS/STORM TRACKS WELL TO THE NORTH AND SOUTH OF OUR CWA. AT THE SURFACE...HIGH PRESSURE IS IN PLACE ACROSS MUCH OF THE PLAINS WITH WEAK TROUGHING ACROSS EASTERN COLORADO...NEBRASKA PANHANDLE. A WEAK STATIONARY FRONT IS ALONG THE CO/KS BORDER JUST EAST OF MAIN TROUGH AXIS. THIS MORNING...CONTINUING TO MONITOR POTENTIAL FOR DENSE FOG DEVELOPMENT. POCKETS OF DENSE FOG HAVE DEVELOPED OVER PARTS OF EASTERN COLORADO (JUST EAST OF OUR CWA) AND AS THE MORNING PROGRESSES MAY INCREASE IN COVERAGE AND ADVECT EASTWARD WITH SHIFTING WINDS TO THE WEST. AT THE SAME TIME THIS WIND SHIFT WILL ALSO RESULT IN A GENERAL "MODERATION" OF TEMPERATURES WHICH COULD INCREASE TD DEPRESSIONS IN ALL BUT LOW LYING AREAS LOWERING FOG COVERAGE. EAST OF THE SURFACE FRONT...MOISTURE POOLING NEAR CONVERGENCE ZONE COULD LEAD TO DENSE FOG DEVELOPMENT AROUND SUNRISE AS SUPPORTED BY EARLIER GUIDANCE. CURRENT SHORT RANGE GUIDANCE IS ACTUALLY SHOWING BETTER DENSE FOG POTENTIAL IN THE WEST MATCHING RECENT TRENDS IN COLORADO...SO ADJUSTMENTS WERE MADE TO INCLUDE FREEZING FOG MENTION FURTHER WEST AS WELL. WILL NEED TO CONTINUE MONITORING AS COVERAGE IS STILL UNCERTAIN...AND DENSE FREEZING FOG COULD CERTAINLY BE POSSIBLE. TODAY-TUESDAY NIGHT...WITH MAIN STORM TRACK OUTSIDE OUR CWA AND A DEEP DRY AIR MASS IN PLACE DRY CONDITIONS ARE EXPECTED. A FEW CLIPPERS MAY PASS NEAR OR EVEN OVER OUR CWA...HOWEVER THE MAIN IMPACT ON SENSIBLE WEATHER WOULD BE POSSIBLE INCREASES IN WINDS DURING THE DAY AND A COLD FRONT PASSAGE TUESDAY. SURFACE TROUGH SHIFT EAST TODAY AND DOWNSLOPE FLOW WILL SUPPORT MODERATING TEMPS TO SEASONAL LEVELS AROUND 40 TODAY TO THE MID 40S MONDAY. HIGHS ARE TRICKY ON TUESDAY AS FROPA MAY OCCUR EARLIER IN THE DAY AND CAA FROM THE NORTHEAST COULD LIMIT HIGHS TO THE 30S OVER PARTS OF THE CWA. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 147 AM MST SUN JAN 10 2016 MODELS STILL HAVE SOME DIFFERENCES THROUGH THIS PERIOD BUT ARE CLOSER TO EACH OTHER THAN YESTERDAY. IN THE BEGINNING STRONG ZONAL FLOW SEEN NOW OVER THE PACIFIC BREAKS THROUGH/FLATTENS CURRENT UPPER RIDGE WITH WEST TO NORTHWEST FLOW ALOFT CONTINUING. OF COURSE DEPENDING ON WHICH MODEL YOU CHOOSE STRONGER RIDGING DEVELOPS OVER THE WEST FOR THE REST OF THE PERIOD AS A STRONG AND COLD UPPER LOW OVER CENTRAL CANADA STARTS MOVING SOUTH. AS A RESULT WARMER/ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THURSDAY. FRIDAY/FRIDAY NIGHT APPEAR TO BE THE TRICKIEST AND MOST UNCERTAIN. NEW INIT DOES COOL TEMPERATURES OFF ABOUT 10 DEGREES FROM THURSDAY TO FRIDAY BUT IS WARMER THAN WHAT WAS FORECAST YESTERDAY. RIGHT NOW IT LOOKS FINE BUT AN EARLIER ARRIVAL OF COLD AIR IS POSSIBLE. MUCH COLDER AIR NOW ARRIVES FRIDAY NIGHT THROUGH THE WEEKEND. OTHER THAN FRIDAY NIGHT WHEN COLD AIR AND SHORTWAVE MOVE THROUGH TO CAUSE A SLIGHT CHANCE OF SNOW...THE FORECAST LOOKS TO REMAIN DRY. WITH THIS LATEST DATA AND TRENDS...WHAT THE INIT GAVE ME LOOKS REASONABLE AND WILL MAKE LITTLE IF ANY CHANGES TO IT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1022 AM MST SUN JAN 10 2016 VFR CONDITIONS EXPECTED FOR BOTH TAF SITES THRU FORECAST PERIOD...WITH SCT120-250. WINDS MEANDERING FROM WEST TO NORTHWEST AROUND 10KTS...WITH GUSTS NEAR 20KTS AFT 14Z MONDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JN SHORT TERM...DR LONG TERM...BULLER AVIATION...JN
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
816 AM MST SUN JAN 10 2016 .UPDATE... ISSUED AT 816 AM MST SUN JAN 10 2016 ISSUED UPDATE TO ZONE FORECAST TO REMOVE MENTION OF FOG AND TO ADJUST CLOUD COVER WORDING. LATEST VISIBLE SATELLITE IMAGE SHOWING ONLY FAR E/NE ZONES UNDER MOSTLY CLOUDY/CLOUDY CONDITIONS...BUT SHOULD CLEAR OVER NEXT FEW HOURS. REST OF FORECAST UNCHANGED AT THIS TIME. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 211 AM MST SUN JAN 10 2016 EARLY MORNING WV IMAGERY AND RAP 500 MB ANALYSIS CONTINUES TO SHOW LARGE SCALE TROUGH ACROSS MUCH OF THE US...WITH RIDGING ALONG THE PACIFIC COAST INTO BRITISH COLUMBIA. NORTH-NORTHWEST FLOW IS IN PLACE ACROSS THE PLAINS WITH MAIN UPPER LEVEL JETS/STORM TRACKS WELL TO THE NORTH AND SOUTH OF OUR CWA. AT THE SURFACE...HIGH PRESSURE IS IN PLACE ACROSS MUCH OF THE PLAINS WITH WEAK TROUGHING ACROSS EASTERN COLORADO...NEBRASKA PANHANDLE. A WEAK STATIONARY FRONT IS ALONG THE CO/KS BORDER JUST EAST OF MAIN TROUGH AXIS. THIS MORNING...CONTINUING TO MONITOR POTENTIAL FOR DENSE FOG DEVELOPMENT. POCKETS OF DENSE FOG HAVE DEVELOPED OVER PARTS OF EASTERN COLORADO (JUST EAST OF OUR CWA) AND AS THE MORNING PROGRESSES MAY INCREASE IN COVERAGE AND ADVECT EASTWARD WITH SHIFTING WINDS TO THE WEST. AT THE SAME TIME THIS WIND SHIFT WILL ALSO RESULT IN A GENERAL "MODERATION" OF TEMPERATURES WHICH COULD INCREASE TD DEPRESSIONS IN ALL BUT LOW LYING AREAS LOWERING FOG COVERAGE. EAST OF THE SURFACE FRONT...MOISTURE POOLING NEAR CONVERGENCE ZONE COULD LEAD TO DENSE FOG DEVELOPMENT AROUND SUNRISE AS SUPPORTED BY EARLIER GUIDANCE. CURRENT SHORT RANGE GUIDANCE IS ACTUALLY SHOWING BETTER DENSE FOG POTENTIAL IN THE WEST MATCHING RECENT TRENDS IN COLORADO...SO ADJUSTMENTS WERE MADE TO INCLUDE FREEZING FOG MENTION FURTHER WEST AS WELL. WILL NEED TO CONTINUE MONITORING AS COVERAGE IS STILL UNCERTAIN...AND DENSE FREEZING FOG COULD CERTAINLY BE POSSIBLE. TODAY-TUESDAY NIGHT...WITH MAIN STORM TRACK OUTSIDE OUR CWA AND A DEEP DRY AIR MASS IN PLACE DRY CONDITIONS ARE EXPECTED. A FEW CLIPPERS MAY PASS NEAR OR EVEN OVER OUR CWA...HOWEVER THE MAIN IMPACT ON SENSIBLE WEATHER WOULD BE POSSIBLE INCREASES IN WINDS DURING THE DAY AND A COLD FRONT PASSAGE TUESDAY. SURFACE TROUGH SHIFT EAST TODAY AND DOWNSLOPE FLOW WILL SUPPORT MODERATING TEMPS TO SEASONAL LEVELS AROUND 40 TODAY TO THE MID 40S MONDAY. HIGHS ARE TRICKY ON TUESDAY AS FROPA MAY OCCUR EARLIER IN THE DAY AND CAA FROM THE NORTHEAST COULD LIMIT HIGHS TO THE 30S OVER PARTS OF THE CWA. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 147 AM MST SUN JAN 10 2016 MODELS STILL HAVE SOME DIFFERENCES THROUGH THIS PERIOD BUT ARE CLOSER TO EACH OTHER THAN YESTERDAY. IN THE BEGINNING STRONG ZONAL FLOW SEEN NOW OVER THE PACIFIC BREAKS THROUGH/FLATTENS CURRENT UPPER RIDGE WITH WEST TO NORTHWEST FLOW ALOFT CONTINUING. OF COURSE DEPENDING ON WHICH MODEL YOU CHOOSE STRONGER RIDGING DEVELOPS OVER THE WEST FOR THE REST OF THE PERIOD AS A STRONG AND COLD UPPER LOW OVER CENTRAL CANADA STARTS MOVING SOUTH. AS A RESULT WARMER/ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THURSDAY. FRIDAY/FRIDAY NIGHT APPEAR TO BE THE TRICKIEST AND MOST UNCERTAIN. NEW INIT DOES COOL TEMPERATURES OFF ABOUT 10 DEGREES FROM THURSDAY TO FRIDAY BUT IS WARMER THAN WHAT WAS FORECAST YESTERDAY. RIGHT NOW IT LOOKS FINE BUT AN EARLIER ARRIVAL OF COLD AIR IS POSSIBLE. MUCH COLDER AIR NOW ARRIVES FRIDAY NIGHT THROUGH THE WEEKEND. OTHER THAN FRIDAY NIGHT WHEN COLD AIR AND SHORTWAVE MOVE THROUGH TO CAUSE A SLIGHT CHANCE OF SNOW...THE FORECAST LOOKS TO REMAIN DRY. WITH THIS LATEST DATA AND TRENDS...WHAT THE INIT GAVE ME LOOKS REASONABLE AND WILL MAKE LITTLE IF ANY CHANGES TO IT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 426 AM MST SUN JAN 10 2016 MONITORING POTENTIAL FOG DEVELOPMENT AT KGLD AND KMCK THIS MORNING. SO FAR FOG HAS NOT DEVELOPED AS EXPECTED...HOWEVER FOG REMAINS POSSIBLE AT BOTH TERMINALS. ONLY POCKETS OF FOG THAT HAVE DEVELOPED THIS MORNING HAVE REMAINED IN EASTERN COLORADO AND SHORT RANGE GUIDANCE FAVORS THIS REMAINING MAINLY WEST OF BOTH TERMINALS. HRRR SHOWS THIS DENSE FOG INCREASING IN COVERAGE AND SPREADING EAST WITHIN THE VICINITY OF THE KGLD TERMINAL...HOWEVER CURRENT TRENDS STILL DO NOT MATCH UP (MODELS ARE STILL TOO EXTENSIVE WITH COVERAGE). WITH BETTER POTENTIAL AT KGLD I INTRODUCED MVFR TEMPO GROUP...HOWEVER CONFIDENCE IN COVERAGE IS STILL TOO LOW TO INTRODUCE IFR OR LOWER CONDITIONS. ANY FOG/LOW STRATUS THAT DEVELOPS SHOULD LIFT BY MIDDAY AS DRIER AIR MOVES INTO THE REGION FROM THE WEST AND DAYTIME TEMPERATURES INCREASE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JN SHORT TERM...DR LONG TERM...BULLER AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
426 AM MST SUN JAN 10 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 211 AM MST SUN JAN 10 2016 EARLY MORNING WV IMAGERY AND RAP 500 MB ANALYSIS CONTINUES TO SHOW LARGE SCALE TROUGH ACROSS MUCH OF THE US...WITH RIDGING ALONG THE PACIFIC COAST INTO BRITISH COLUMBIA. NORTH-NORTHWEST FLOW IS IN PLACE ACROSS THE PLAINS WITH MAIN UPPER LEVEL JETS/STORM TRACKS WELL TO THE NORTH AND SOUTH OF OUR CWA. AT THE SURFACE...HIGH PRESSURE IS IN PLACE ACROSS MUCH OF THE PLAINS WITH WEAK TROUGHING ACROSS EASTERN COLORADO...NEBRASKA PANHANDLE. A WEAK STATIONARY FRONT IS ALONG THE CO/KS BORDER JUST EAST OF MAIN TROUGH AXIS. THIS MORNING...CONTINUING TO MONITOR POTENTIAL FOR DENSE FOG DEVELOPMENT. POCKETS OF DENSE FOG HAVE DEVELOPED OVER PARTS OF EASTERN COLORADO (JUST EAST OF OUR CWA) AND AS THE MORNING PROGRESSES MAY INCREASE IN COVERAGE AND ADVECT EASTWARD WITH SHIFTING WINDS TO THE WEST. AT THE SAME TIME THIS WIND SHIFT WILL ALSO RESULT IN A GENERAL "MODERATION" OF TEMPERATURES WHICH COULD INCREASE TD DEPRESSIONS IN ALL BUT LOW LYING AREAS LOWERING FOG COVERAGE. EAST OF THE SURFACE FRONT...MOISTURE POOLING NEAR CONVERGENCE ZONE COULD LEAD TO DENSE FOG DEVELOPMENT AROUND SUNRISE AS SUPPORTED BY EARLIER GUIDANCE. CURRENT SHORT RANGE GUIDANCE IS ACTUALLY SHOWING BETTER DENSE FOG POTENTIAL IN THE WEST MATCHING RECENT TRENDS IN COLORADO...SO ADJUSTMENTS WERE MADE TO INCLUDE FREEZING FOG MENTION FURTHER WEST AS WELL. WILL NEED TO CONTINUE MONITORING AS COVERAGE IS STILL UNCERTAIN...AND DENSE FREEZING FOG COULD CERTAINLY BE POSSIBLE. TODAY-TUESDAY NIGHT...WITH MAIN STORM TRACK OUTSIDE OUR CWA AND A DEEP DRY AIR MASS IN PLACE DRY CONDITIONS ARE EXPECTED. A FEW CLIPPERS MAY PASS NEAR OR EVEN OVER OUR CWA...HOWEVER THE MAIN IMPACT ON SENSIBLE WEATHER WOULD BE POSSIBLE INCREASES IN WINDS DURING THE DAY AND A COLD FRONT PASSAGE TUESDAY. SURFACE TROUGH SHIFT EAST TODAY AND DOWNSLOPE FLOW WILL SUPPORT MODERATING TEMPS TO SEASONAL LEVELS AROUND 40 TODAY TO THE MID 40S MONDAY. HIGHS ARE TRICKY ON TUESDAY AS FROPA MAY OCCUR EARLIER IN THE DAY AND CAA FROM THE NORTHEAST COULD LIMIT HIGHS TO THE 30S OVER PARTS OF THE CWA. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 147 AM MST SUN JAN 10 2016 MODELS STILL HAVE SOME DIFFERENCES THROUGH THIS PERIOD BUT ARE CLOSER TO EACH OTHER THAN YESTERDAY. IN THE BEGINNING STRONG ZONAL FLOW SEEN NOW OVER THE PACIFIC BREAKS THROUGH/FLATTENS CURRENT UPPER RIDGE WITH WEST TO NORTHWEST FLOW ALOFT CONTINUING. OF COURSE DEPENDING ON WHICH MODEL YOU CHOOSE STRONGER RIDGING DEVELOPS OVER THE WEST FOR THE REST OF THE PERIOD AS A STRONG AND COLD UPPER LOW OVER CENTRAL CANADA STARTS MOVING SOUTH. AS A RESULT WARMER/ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THURSDAY. FRIDAY/FRIDAY NIGHT APPEAR TO BE THE TRICKIEST AND MOST UNCERTAIN. NEW INIT DOES COOL TEMPERATURES OFF ABOUT 10 DEGREES FROM THURSDAY TO FRIDAY BUT IS WARMER THAN WHAT WAS FORECAST YESTERDAY. RIGHT NOW IT LOOKS FINE BUT AN EARLIER ARRIVAL OF COLD AIR IS POSSIBLE. MUCH COLDER AIR NOW ARRIVES FRIDAY NIGHT THROUGH THE WEEKEND. OTHER THAN FRIDAY NIGHT WHEN COLD AIR AND SHORTWAVE MOVE THROUGH TO CAUSE A SLIGHT CHANCE OF SNOW...THE FORECAST LOOKS TO REMAIN DRY. WITH THIS LATEST DATA AND TRENDS...WHAT THE INIT GAVE ME LOOKS REASONABLE AND WILL MAKE LITTLE IF ANY CHANGES TO IT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 426 AM MST SUN JAN 10 2016 MONITORING POTENTIAL FOG DEVELOPMENT AT KGLD AND KMCK THIS MORNING. SO FAR FOG HAS NOT DEVELOPED AS EXPECTED...HOWEVER FOG REMAINS POSSIBLE AT BOTH TERMINALS. ONLY POCKETS OF FOG THAT HAVE DEVELOPED THIS MORNING HAVE REMAINED IN EASTERN COLORADO AND SHORT RANGE GUIDANCE FAVORS THIS REMAINING MAINLY WEST OF BOTH TERMINALS. HRRR SHOWS THIS DENSE FOG INCREASING IN COVERAGE AND SPREADING EAST WITHIN THE VICINITY OF THE KGLD TERMINAL...HOWEVER CURRENT TRENDS STILL DO NOT MATCH UP (MODELS ARE STILL TOO EXTENSIVE WITH COVERAGE). WITH BETTER POTENTIAL AT KGLD I INTRODUCED MVFR TEMPO GROUP...HOWEVER CONFIDENCE IN COVERAGE IS STILL TOO LOW TO INTRODUCE IFR OR LOWER CONDITIONS. ANY FOG/LOW STRATUS THAT DEVELOPS SHOULD LIFT BY MIDDAY AS DRIER AIR MOVES INTO THE REGION FROM THE WEST AND DAYTIME TEMPERATURES INCREASE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...BULLER AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
211 AM MST SUN JAN 10 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 211 AM MST SUN JAN 10 2016 EARLY MORNING WV IMAGERY AND RAP 500 MB ANALYSIS CONTINUES TO SHOW LARGE SCALE TROUGH ACROSS MUCH OF THE US...WITH RIDGING ALONG THE PACIFIC COAST INTO BRITISH COLUMBIA. NORTH-NORTHWEST FLOW IS IN PLACE ACROSS THE PLAINS WITH MAIN UPPER LEVEL JETS/STORM TRACKS WELL TO THE NORTH AND SOUTH OF OUR CWA. AT THE SURFACE...HIGH PRESSURE IS IN PLACE ACROSS MUCH OF THE PLAINS WITH WEAK TROUGHING ACROSS EASTERN COLORADO...NEBRASKA PANHANDLE. A WEAK STATIONARY FRONT IS ALONG THE CO/KS BORDER JUST EAST OF MAIN TROUGH AXIS. THIS MORNING...CONTINUING TO MONITOR POTENTIAL FOR DENSE FOG DEVELOPMENT. POCKETS OF DENSE FOG HAVE DEVELOPED OVER PARTS OF EASTERN COLORADO (JUST EAST OF OUR CWA) AND AS THE MORNING PROGRESSES MAY INCREASE IN COVERAGE AND ADVECT EASTWARD WITH SHIFTING WINDS TO THE WEST. AT THE SAME TIME THIS WIND SHIFT WILL ALSO RESULT IN A GENERAL "MODERATION" OF TEMPERATURES WHICH COULD INCREASE TD DEPRESSIONS IN ALL BUT LOW LYING AREAS LOWERING FOG COVERAGE. EAST OF THE SURFACE FRONT...MOISTURE POOLING NEAR CONVERGENCE ZONE COULD LEAD TO DENSE FOG DEVELOPMENT AROUND SUNRISE AS SUPPORTED BY EARLIER GUIDANCE. CURRENT SHORT RANGE GUIDANCE IS ACTUALLY SHOWING BETTER DENSE FOG POTENTIAL IN THE WEST MATCHING RECENT TRENDS IN COLORADO...SO ADJUSTMENTS WERE MADE TO INCLUDE FREEZING FOG MENTION FURTHER WEST AS WELL. WILL NEED TO CONTINUE MONITORING AS COVERAGE IS STILL UNCERTAIN...AND DENSE FREEZING FOG COULD CERTAINLY BE POSSIBLE. TODAY-TUESDAY NIGHT...WITH MAIN STORM TRACK OUTSIDE OUR CWA AND A DEEP DRY AIR MASS IN PLACE DRY CONDITIONS ARE EXPECTED. A FEW CLIPPERS MAY PASS NEAR OR EVEN OVER OUR CWA...HOWEVER THE MAIN IMPACT ON SENSIBLE WEATHER WOULD BE POSSIBLE INCREASES IN WINDS DURING THE DAY AND A COLD FRONT PASSAGE TUESDAY. SURFACE TROUGH SHIFT EAST TODAY AND DOWNSLOPE FLOW WILL SUPPORT MODERATING TEMPS TO SEASONAL LEVELS AROUND 40 TODAY TO THE MID 40S MONDAY. HIGHS ARE TRICKY ON TUESDAY AS FROPA MAY OCCUR EARLIER IN THE DAY AND CAA FROM THE NORTHEAST COULD LIMIT HIGHS TO THE 30S OVER PARTS OF THE CWA. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 147 AM MST SUN JAN 10 2016 MODELS STILL HAVE SOME DIFFERENCES THROUGH THIS PERIOD BUT ARE CLOSER TO EACH OTHER THAN YESTERDAY. IN THE BEGINNING STRONG ZONAL FLOW SEEN NOW OVER THE PACIFIC BREAKS THROUGH/FLATTENS CURRENT UPPER RIDGE WITH WEST TO NORTHWEST FLOW ALOFT CONTINUING. OF COURSE DEPENDING ON WHICH MODEL YOU CHOOSE STRONGER RIDGING DEVELOPS OVER THE WEST FOR THE REST OF THE PERIOD AS A STRONG AND COLD UPPER LOW OVER CENTRAL CANADA STARTS MOVING SOUTH. AS A RESULT WARMER/ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THURSDAY. FRIDAY/FRIDAY NIGHT APPEAR TO BE THE TRICKIEST AND MOST UNCERTAIN. NEW INIT DOES COOL TEMPERATURES OFF ABOUT 10 DEGREES FROM THURSDAY TO FRIDAY BUT IS WARMER THAN WHAT WAS FORECAST YESTERDAY. RIGHT NOW IT LOOKS FINE BUT AN EARLIER ARRIVAL OF COLD AIR IS POSSIBLE. MUCH COLDER AIR NOW ARRIVES FRIDAY NIGHT THROUGH THE WEEKEND. OTHER THAN FRIDAY NIGHT WHEN COLD AIR AND SHORTWAVE MOVE THROUGH TO CAUSE A SLIGHT CHANCE OF SNOW...THE FORECAST LOOKS TO REMAIN DRY. WITH THIS LATEST DATA AND TRENDS...WHAT THE INIT GAVE ME LOOKS REASONABLE AND WILL MAKE LITTLE IF ANY CHANGES TO IT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1000 PM MST SAT JAN 9 2016 KGLD...VFR CONDITIONS EXPECTED THROUGH THE PERIOD. LATEST MODEL GUIDANCE SHOWING IFR/VLIFR CONDITIONS HAPPENING JUST EAST OF THE TERMINAL BUT IT WILL BE CLOSE. BEST CHANCE FOR SUB VFR CONDITIONS WOULD BE FROM TAF ISSUANCE THROUGH 12Z OR SO. OTHERWISE DURING THE AFTERNOON AND EVENING HOURS A CLEAR SKY EXPECTED. WINDS LIGHT FROM THE SOUTH AT TAF ISSUANCE SLOWLY VEERING TO THE WEST BY 17Z THEN NORTHWEST AROUND 21Z BEFORE BACKING TO THE WEST BY 02Z. WIND SPEEDS THROUGH THE PERIOD UNDER 10KTS. KMCK...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 08Z WITH NEAR CALM WINDS. FROM 09Z-16Z CIGS START MVFR BUT QUICKLY FALL TO IFR/VLIFR RANGE (12Z-16Z) AS STRATUS MOVES SLOWLY EAST ACROSS THE TERMINAL. WINDS REMAIN LIGHT. AFTER 17Z VFR CONDITIONS RETURN WITH A CLEAR SKY EXPECTED AND WINDS FROM THE WEST/WEST-SOUTHWEST AROUND 7KTS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...BULLER AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 PM MST SAT JAN 9 2016 .UPDATE... ISSUED AT 915 PM MST SAT JAN 9 2016 00Z NAM/RUC/HRRR AND 03Z RUC ARE ADVERTISING THE THREAT FOR FREEZING FOG HAS SHIFTED TO A LINE EXTENDING FROM NEAR BENKELMAN NEBRASKA TO COLBY AND RUSSELL SPRINGS KANSAS OVERNIGHT...SLOWLY MOVING EAST WHILE LOSING COVERAGE TOMORROW MORNING. VISIBILITY FORECASTS ARENT ENOUGH TO SWAY ME INTO AN ADVISORY AT PRESENT TIME. GRIDS HAVE BEEN UPDATED TO REFLECT CURRENT THINKING. UPDATE ISSUED AT 415 PM MST SAT JAN 9 2016 HAVE QUITE A BIT OF CONCERN ABOUT FOG TONIGHT AND THE CHANCE THAT DENSE FOG MAY DEVELOP. QUICK LOOK AT 18Z DATA SUGGESTS THAT AREAS ALONG AND WEST OF THE CO/KS BORDER WILL BE IN A SQUEEZE PLAY BETWEEN LEE TROUGH ALONG THE FRONT RANGE AND SFC HIGH JUST EAST OF THE FORECAST AREA. THIS WILL CREATE LOW LEVEL WIND CONVERGENCE ALONG THE CO/KS BORDER. BOUNDARY LAYER MOISTURE IS EXPECTED TO INCREASE...ESPECIALLY AFTER MIDNIGHT...PROVIDING A FAVORABLE SET UP FOR FOG AND POSSIBLY DENSE FOG IN A NORTH-SOUTH ORIENTED AXIS. WILL AWAIT 00Z MODEL DATA BEFORE COMMITTING TO ANY POSSIBLE HIGHLITES. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 155 PM MST SAT JAN 9 2016 ACROSS THE TRI STATE REGION THIS AFTERNOON...THE AREA STILL REMAINS UNDER A MIX OF PARTLY TO MOSTLY SUNNY SKIES AS THE CWA STILL TRYING TO FULLY SHAKE OFF THE VEIL OF MORNING LOW CLOUDS. TEMPS STILL RANGING MAINLY IN THE 20S...INHIBITED IN SOME LOCALES DUE TO LACK OF SUNSHINE. SURFACE WINDS CONTINUE TO MOVE IN FROM THE NORTH...WITH THE GRADIENT SLACKENING SLOWLY FROM WEST TO EAST...AS REGION AWAITS SURFACE RIDGE AXIS TO BUILD OVER THE AREA GOING INTO THE EVENING HOURS. GOING INTO THE OVERNIGHT HOURS THOUGH...A WEAK SHORTWAVE WILL MOVE SOUTH ALONG THE FRONT RANGE AS RIDGE BEGIN TO PUSH AWAY FROM THE CWA. WEAK CONVERGENCE AREA MAY ALLOW FOR SOME INCREASED CLOUD COVER FOR WESTERN ZONES IN THE 06Z-12Z TIME FRAME. THIS IN TURN SHOULD HOLD UP TEMPS SLIGHTLY IN THESE AREAS...VERSUS THOSE LOCALES EAST. OVERNIGHT LOWS WILL TREND AROUND 10F WEST VERSUS SINGLE NUMBERS FOR THE EAST CWA WHERE CLOUD COVER LEAST. WESTERN ZONES MAY ALSO SEE SOME PATCHY FOG SET UP FOR A FEW HOURS AS WELL. SURFACE RIDGE EXPECTED TO CONTINUE TRACKING ESE OF THE FORECAST AREA GOING INTO SUNDAY...SETTING THE AREA UP WITH A SSW GRADIENT THRU THE DAY. THIS COMBINED WITH A WNW(DOWNSLOPE) UPPER FLOW AT 500/700MB WILL GIVE THE CWA A WARMER DAY WITH HIGHS REACHING INTO THE MID AND UPPER 30S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 202 PM MST SAT JAN 9 2016 FOR THIS EXTENDED FORECAST PERIOD...BENIGN WEATHER IS ANTICIPATED DUE TO THE LACK OF PATTERN CHANGES OR UPPER LEVEL DISTURBANCES. NORTHWEST FLOW SHOULD DOMINATE THROUGHOUT THE EXTENDED FORECAST PERIOD. WITHOUT ANY NOTABLE MOISTURE ADVECTION...PRECIPITATION SHOULD NOT BE EXPECTED DUE TO THE LACK OF MOISTURE. THE PRIMARY INFLUENCE ON OUR WEATHER FROM SUNDAY NIGHT ONWARDS WILL BE THE STRENGTH OF THE WESTERN UNITED STATES HIGH PRESSURE RIDGE. A COUPLE SHORTWAVE TROUGHS ARE FORECAST TO SLIDE SOUTH OVER THE PLAINS...BRIEFLY WEAKENING THE RIDGE OF HIGH PRESSURE. AS THIS HAPPENS...A COLD FRONT SHOULD BE FORCED INTO THE REGION WITH AN ASSOCIATED COOLING OF TEMPERATURES. HOWEVER...AS THE HIGH PRESSURE RIDGE REBUILDS OVER THE HIGH PLAINS AND SOUTH WINDS RETURN... TEMPERATURES SHOULD RECOVER. BASED ON LATEST GUIDANCE...THE MOST LIKELY DAYS FOR COOLER TEMPERATURES ARE TUESDAY AND FRIDAY. COLDER WEATHER SHOULD PERSIST INTO NEXT WEEKEND AFTER FRIDAY`S FRONT. FOR MONDAY...WEDNESDAY AND THURSDAY...NEAR TO ABOVE NORMAL TEMPERATURES ARE MOST LIKELY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1000 PM MST SAT JAN 9 2016 KGLD...VFR CONDITIONS EXPECTED THROUGH THE PERIOD. LATEST MODEL GUIDANCE SHOWING IFR/VLIFR CONDITIONS HAPPENING JUST EAST OF THE TERMINAL BUT IT WILL BE CLOSE. BEST CHANCE FOR SUB VFR CONDITIONS WOULD BE FROM TAF ISSUANCE THROUGH 12Z OR SO. OTHERWISE DURING THE AFTERNOON AND EVENING HOURS A CLEAR SKY EXPECTED. WINDS LIGHT FROM THE SOUTH AT TAF ISSUANCE SLOWLY VEERING TO THE WEST BY 17Z THEN NORTHWEST AROUND 21Z BEFORE BACKING TO THE WEST BY 02Z. WIND SPEEDS THROUGH THE PERIOD UNDER 10KTS. KMCK...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 08Z WITH NEAR CALM WINDS. FROM 09Z-16Z CIGS START MVFR BUT QUICKLY FALL TO IFR/VLIFR RANGE (12Z-16Z) AS STRATUS MOVES SLOWLY EAST ACROSS THE TERMINAL. WINDS REMAIN LIGHT. AFTER 17Z VFR CONDITIONS RETURN WITH A CLEAR SKY EXPECTED AND WINDS FROM THE WEST/WEST-SOUTHWEST AROUND 7KTS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...JN LONG TERM...RRH AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
915 PM MST SAT JAN 9 2016 .UPDATE... ISSUED AT 915 PM MST SAT JAN 9 2016 00Z NAM/RUC/HRRR AND 03Z RUC ARE ADVERTISING THE THREAT FOR FREEZING FOG HAS SHIFTED TO A LINE EXTENDING FROM NEAR BENKELMAN NEBRASKA TO COLBY AND RUSSELL SPRINGS KANSAS OVERNIGHT...SLOWLY MOVING EAST WHILE LOSING COVERAGE TOMORROW MORNING. VISIBILITY FORECASTS ARENT ENOUGH TO SWAY ME INTO AN ADVISORY AT PRESENT TIME. GRIDS HAVE BEEN UPDATED TO REFLECT CURRENT THINKING. UPDATE ISSUED AT 415 PM MST SAT JAN 9 2016 HAVE QUITE A BIT OF CONCERN ABOUT FOG TONIGHT AND THE CHANCE THAT DENSE FOG MAY DEVELOP. QUICK LOOK AT 18Z DATA SUGGESTS THAT AREAS ALONG AND WEST OF THE CO/KS BORDER WILL BE IN A SQUEEZE PLAY BETWEEN LEE TROUGH ALONG THE FRONT RANGE AND SFC HIGH JUST EAST OF THE FORECAST AREA. THIS WILL CREATE LOW LEVEL WIND CONVERGENCE ALONG THE CO/KS BORDER. BOUNDARY LAYER MOISTURE IS EXPECTED TO INCREASE...ESPECIALLY AFTER MIDNIGHT...PROVIDING A FAVORABLE SET UP FOR FOG AND POSSIBLY DENSE FOG IN A NORTH-SOUTH ORIENTED AXIS. WILL AWAIT 00Z MODEL DATA BEFORE COMMITTING TO ANY POSSIBLE HIGHLITES. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 155 PM MST SAT JAN 9 2016 ACROSS THE TRI STATE REGION THIS AFTERNOON...THE AREA STILL REMAINS UNDER A MIX OF PARTLY TO MOSTLY SUNNY SKIES AS THE CWA STILL TRYING TO FULLY SHAKE OFF THE VEIL OF MORNING LOW CLOUDS. TEMPS STILL RANGING MAINLY IN THE 20S...INHIBITED IN SOME LOCALES DUE TO LACK OF SUNSHINE. SURFACE WINDS CONTINUE TO MOVE IN FROM THE NORTH...WITH THE GRADIENT SLACKENING SLOWLY FROM WEST TO EAST...AS REGION AWAITS SURFACE RIDGE AXIS TO BUILD OVER THE AREA GOING INTO THE EVENING HOURS. GOING INTO THE OVERNIGHT HOURS THOUGH...A WEAK SHORTWAVE WILL MOVE SOUTH ALONG THE FRONT RANGE AS RIDGE BEGIN TO PUSH AWAY FROM THE CWA. WEAK CONVERGENCE AREA MAY ALLOW FOR SOME INCREASED CLOUD COVER FOR WESTERN ZONES IN THE 06Z-12Z TIME FRAME. THIS IN TURN SHOULD HOLD UP TEMPS SLIGHTLY IN THESE AREAS...VERSUS THOSE LOCALES EAST. OVERNIGHT LOWS WILL TREND AROUND 10F WEST VERSUS SINGLE NUMBERS FOR THE EAST CWA WHERE CLOUD COVER LEAST. WESTERN ZONES MAY ALSO SEE SOME PATCHY FOG SET UP FOR A FEW HOURS AS WELL. SURFACE RIDGE EXPECTED TO CONTINUE TRACKING ESE OF THE FORECAST AREA GOING INTO SUNDAY...SETTING THE AREA UP WITH A SSW GRADIENT THRU THE DAY. THIS COMBINED WITH A WNW(DOWNSLOPE) UPPER FLOW AT 500/700MB WILL GIVE THE CWA A WARMER DAY WITH HIGHS REACHING INTO THE MID AND UPPER 30S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 202 PM MST SAT JAN 9 2016 FOR THIS EXTENDED FORECAST PERIOD...BENIGN WEATHER IS ANTICIPATED DUE TO THE LACK OF PATTERN CHANGES OR UPPER LEVEL DISTURBANCES. NORTHWEST FLOW SHOULD DOMINATE THROUGHOUT THE EXTENDED FORECAST PERIOD. WITHOUT ANY NOTABLE MOISTURE ADVECTION...PRECIPITATION SHOULD NOT BE EXPECTED DUE TO THE LACK OF MOISTURE. THE PRIMARY INFLUENCE ON OUR WEATHER FROM SUNDAY NIGHT ONWARDS WILL BE THE STRENGTH OF THE WESTERN UNITED STATES HIGH PRESSURE RIDGE. A COUPLE SHORTWAVE TROUGHS ARE FORECAST TO SLIDE SOUTH OVER THE PLAINS...BRIEFLY WEAKENING THE RIDGE OF HIGH PRESSURE. AS THIS HAPPENS...A COLD FRONT SHOULD BE FORCED INTO THE REGION WITH AN ASSOCIATED COOLING OF TEMPERATURES. HOWEVER...AS THE HIGH PRESSURE RIDGE REBUILDS OVER THE HIGH PLAINS AND SOUTH WINDS RETURN... TEMPERATURES SHOULD RECOVER. BASED ON LATEST GUIDANCE...THE MOST LIKELY DAYS FOR COOLER TEMPERATURES ARE TUESDAY AND FRIDAY. COLDER WEATHER SHOULD PERSIST INTO NEXT WEEKEND AFTER FRIDAY`S FRONT. FOR MONDAY...WEDNESDAY AND THURSDAY...NEAR TO ABOVE NORMAL TEMPERATURES ARE MOST LIKELY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 400 PM MST SAT JAN 9 2016 AM EXPECTING A CHALLENGING TAF FORECAST THIS CYCLE AT BOTH KGLD AND KMCK...MAINLY REGARDING CIGS AND VISIBILITIES. KGLD...BEGINNING OF THE PERIOD WILL SEE A CLEAR SKY WITH WINDS FROM THE NORTH AROUND 6KTS. THIS CONTINUES THROUGH ABOUT 03Z BEFORE WINDS BECOME VERY LIGHT FROM THE SOUTHEAST...IN BETWEEN SFC HIGH TO THE EAST AND LEE TROUGH TO THE WEST. LOW LEVEL CONVERGENCE IN THESE WINDS AND INCREASING BOUNDARY LAYER MOISTURE FAVOR CIGS TO LOWER TO MVFR RANGE AROUND 06Z. BETWEEN 06Z AND 09Z CIGS EXPECTED TO FURTHER LOWER INTO VLIFR RANGE AS VERY LOW LEVELS CONTINUE TO MOISTEN AND LOW LEVEL WIND CONVERGENCE REMAINS OVER THE TERMINAL. BR/FG EXPECTED TO DEVELOP AS WELL AND CURRENTLY HAVE VISIBILITY DOWN TO 1 MILE BUT COULD CERTAINLY SEE POSSIBLY OF 1/4SM AS SOME OF THE GUIDANCE SUGGESTS. LITTLE CHANGE EXPECTED TIL MAYBE 15Z OR 16Z WHEN STRATUS STARTS TO MOVE EAST OF THE TERMINAL ALLOWING VFR CONDITIONS TO RETURN BY 18Z AS WINDS BECOME WEST/WEST-NORTHWEST NEAR 10KTS. FOR THE 19Z-00Z TIMEFRAME WINDS CONTINUE FROM THE NORTHWEST AROUND 10KTS UNDER A GENERALLY CLEAR SKY. KMCK...COULD SEE AN HOUR OR TWO OF MVFR CIGS AT THE BEGINNING OF THE PERIOD WITH WINDS FROM THE NORTH AROUND 6KTS. BY 03Z A CLEAR SKY EXPECTED WITH LIGHT AND VARIABLE WINDS. STRATUS LOOKS TO ARRIVE FROM THE WEST AROUND 09Z PRODUCING MVFR CIGS. THIS CONTINUES THROUGH 12Z OR SO BEFORE IFR CIGS ARRIVE AND CONTINUE THROUGH 17Z. FINALLY BY 21Z VFR CONDITIONS ARE EXPECTED WITH WINDS FROM THE WEST/WEST-SOUTHWEST AROUND 7KTS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...99 SHORT TERM...JN LONG TERM...RRH AVIATION...99
AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 PM EST MON JAN 11 2016 .UPDATE... ISSUED AT 1057 PM EST MON JAN 11 2016 UPSTREAM IN INDIANA AND ILLINOIS...SNOW SHOWERS ARE BEGINNING TO DEVELOP AHEAD OF THE APPROACHING COLD FRONT. AS OF RIGHT NOW...THE SNOW SEEMS TO BE ON TRACK AND ON TIME FOR AN ARRIVAL INTO EASTERN KENTUCKY BY 12Z. THE REST OF THE FORECAST SEEMS TO CONTINUE TO BE ON TRACK. HAVE UPDATED TO INPUT THE LASTEST OBS INTO THE GRIDS. UPDATE ISSUED AT 645 PM EST MON JAN 11 2016 WITH AN ANTICIPATED TEMPERATURES DROP AGAIN TONIGHT...CURRENT TEMPERATURE TRENDS LOOK TO BE ON TRACK WITH THE EXCEPTION OF A TWEAK HERE AND THERE TO THE TEMPS AND DEW POINTS. OTHERWISE...THE FORECAST REMAINS ON TRACK. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 355 PM EST MON JAN 11 2016 A CLOSED UPPER LEVEL LOW WAS OVER HUDSON BAY AS OF MID AFTERNOON WITH A SOMEWHAT BROAD TROUGH EXTENDING SOUTH INTO THE EASTERN CONUS. RIDGING EXTENDED INTO THE WESTERN CONUS. WITHIN THIS TROUGH...A SHORTWAVE WAS NEARING THE MID MS VALLEY WITH AN ADDITIONAL SHORTWAVE APPROACHING THE DAKOTAS AND UPPER MS VALLEY REGION. THE INITIAL SHORTWAVE IS EXPECTED TO ROTATE INTO THE LOWER OH VALLEY TONIGHT...WHILE THE SHORTWAVE FURTHER NORTHWEST SHOULD DEEPEN AS IT ROTATES INTO THE GREAT LAKES. A SFC LOW PRESSURE SYSTEM ASSOCIATED WITH THIS SHOULD BEGIN TO ORGANIZE BY THIS EVENING AND DEEPEN AS IT MOVES INTO THE GREAT LAKES AND SEND AN ARCTIC COLD FRONT INTO THE OH VALLEY AND APPALACHIAN REGION ON TUESDAY. AN INITIAL BAND OF SNOW IS EXPECTED TO MOVE INTO MAINLY NORTHERN PORTIONS OF THE AREA LATE TONIGHT INTO TUESDAY MORNING...POSSIBLY AFFECTING THE MORNING COMMUTE. ADDITIONAL SNOW SHOWERS AND OR SNOW SQUALLS ARE THEN EXPECTED AS THE ARCTIC BOUNDARY MOVES THROUGH ON TUESDAY AFTERNOON INTO TUESDAY EVENING...WITH THESE POSSIBLY IMPACTING THE EVENING COMMUTE. AN AIRMASS EQUALLY AS COLD AS THE ONE THAT MOVED INTO THE AREA ON SUNDAY INTO SUNDAY EVENING WILL MOVE INTO THE AREA BEHIND THIS FRONT FOR TUESDAY NIGHT. HEIGHT RISES ARE EXPECTED LATE IN THE PERIOD...WITH SFC HIGH PRESSURE BUILDING INTO THE AREA. SOMEWHAT LIMITED MOISTURE IS EXPECTED WITH THIS SYSTEM...WITH MANY OF THE MODELS SHOWING SOME VARIABILITY IN QPF AND ANY QPF MAX PLACEMENT. MODELS REMAIN MOST CONSISTENT WITH THE HIGHEST QPF ON AVERAGE ACROSS THE NORTH WHERE SOMEWHAT MORE STRATIFORM SNOW MAY AFFECT THE AREA VERY LATE TONIGHT INTO EARLY ON TUESDAY. ENOUGH INSTABILITY IS ANTICIPATED FOR SNOW SHOWERS AND A FEW SNOW SQUALLS THROUGHOUT THE DAY ON TUESDAY LINGERING INTO TUESDAY EVENING. THE LOW LEVEL FLOW NEVER BECOMES MORE IDEAL UPSLOPE WNW OR NW...HOWEVER. 1 TO 2 INCH AMOUNTS ARE ANTICIPATED ACROSS THE NORTH...WITH MORE VARIABLE AMOUNTS ANTICIPATED FURTHER SOUTH ACROSS THE CENTRAL AND SOUTHEAST PART OF THE AREA DUE TO THE NATURE OF SNOW SHOWERS OR SNOW SQUALLS. THE OTHER LIMITING FACTOR WILL BE TEMPERATURES POSSIBLY RISING A COUPLE OF DEGREES ABOVE FREEZING ACROSS THE VALLEYS AND PARTS OF THE SOUTH BEFORE THE FRONT GOES THROUGH. HOWEVER...COLD GROUND GOING INTO THE EVENT IS FAVORABLE. A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR MOST OF THE AREA STARTING LATE TONIGHT OR EARLY ON TUESDAY MORNING INTO TUESDAY EVENING. ISOLATED SNOW SHOWERS AND FLURRIES SHOULD LINGER WELL INTO TUESDAY NIGHT UNTIL THE LOW LEVEL CLOUDS SCATTER OUT. LOW TEMPERATURES ON TUESDAY NIGHT SHOULD BE COMPARABLE TO WHAT WAS OBSERVED THIS MORNING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 301 PM EST MON JAN 11 2016 ZONAL FLOW WILL RETURN THROUGH THE SECOND HALF OF THE WEEK...ALLOWING FOR A WARMING TREND INTO THE END OF THE WEEK. THIS WARM UP WILL BE BRIEF HOWEVER...AS ANOTHER DEEP UPPER LEVEL TROUGH DIGS ACROSS THE EASTERN CONUS. THIS WILL BRING MORE ACTIVE WEATHER AS WE HEAD THROUGH THE UPCOMING WEEKEND. THE PERIOD WILL START OFF COLD ON WEDNESDAY AS 850MB TEMPERATURES REMAIN UNDER -10C AND WITH POSSIBLE SNOW COVER...WEDNESDAY HIGHS ARE NOT EXPECTED TO RECOVER MUCH. A MUCH WEAKER CLIPPER SYSTEM WILL PUSH ACROSS THE OHIO RIVER VALLEY LATE WEDNESDAY AND BRING INCREASED CLOUD COVER TO THE REGION. HOWEVER...THIS TIME AROUND...LOW LEVEL MOISTURE IS LIMITED AND NOT EXPECTING ANY SNOWFALL. HOWEVER...THE CLOUD COVER WILL FURTHER LIMIT ANY TEMPERATURE RISE ON WEDNESDAY. HOWEVER...AS THIS CLIPPER SYSTEM MOVES ON OUT...SOUTH-SOUTHWEST FLOW WILL KICK IN WITH TEMPERATURE MODERATING ON THURSDAY AND FRIDAY. THIS WILL SEND HIGHS BACK ABOVE NORMAL WITH READING CLOSE TO 50 ON THURSDAY AND INTO THE 50S ON FRIDAY. A POTENT MID LEVEL WAVE WILL THEN EMERGE FROM THE SOUTHERN PLAINS FRIDAY HELPING TO GENERATE A LOW PRESSURE SYSTEM OVER THE MID MISSISSIPPI RIVER VALLEY. EASTERN KENTUCKY WILL REMAIN ON THE WARM SIDE OF THIS SYSTEM...WITH PRIMARILY RAIN EXPECTED. WHILE THERE IS STILL SOME TIMING DIFFERENCES...IT APPEARS RAIN CHANCES WILL INCREASE FRIDAY AFTERNOON WITH THE BEST CHANCES FOR RAIN COMING FRIDAY NIGHT. BY THIS WEEKEND...MODELS HAVE BEEN HAVING A TOUGH TIME RESOLVING HOW THINGS WILL PLAY OUT. OVERALL...THERE HAS BEEN A CLEAR TENDENCY TO SPEED UP THE SYSTEM...ALLOWING FOR A FASTER RETURN OF COLD WEATHER INTO EASTERN KENTUCKY ON SATURDAY. THIS MEANS IT LOOKS LIKE MORE OF THE WEEKEND IS SHAPING UP TO BE COLD WITH HIGHS ON SATURDAY ONLY IN THE 30S...AND HIGHS ON SUNDAY IN THE 20S. ON TOP OF THIS...AS THE RAIN DEPARTS LATE FRIDAY NIGHT...A SECONDARY SURGE OF MOISTURE WILL CROSS THE AREA SATURDAY AND COULD GIVE US SOME SNOW SHOWERS. FORTUNATELY...TEMPERATURES MAY NOT TAKE A SHARP TUMBLE...KEEPING TEMPERATURES NEAR OR SLIGHTLY ABOVE FREEZING THROUGH THE DAY AND LIMITING THE IMPACTS FROM ANY SNOW SHOWER ACTIVITY. HOWEVER...SATURDAY NIGHT INTO SUNDAY WILL BEAR WATCHING AS ANY MOISTURE LEFT ON THE ROADS COULD CAUSE ISSUES AS TEMPERATURES CONTINUE TO FALL. MODELS SUGGEST EITHER A SECOND WAVE TO COME THROUGH SUNDAY OR A SLOWER SYSTEM...TO KEEP SOME SNOW SHOWERS INTO THE FORECAST. HOWEVER...REALITY IS...WE PROBABLY WON`T SEE THAT MUCH SNOW OVERALL THIS WEEKEND...BUT HAD TO GO WITH A LONGER PERIOD TO ACCOUNT FOR MODEL UNCERTAINTY. WEATHER WILL QUIET DOWN BY LATE SUNDAY...BUT MODELS CONTINUE TO DIFFER ON EXACTLY HOW COLD WE GET LATE THIS WEEKEND INTO EARLY NEXT WEEK. ECMWF REMAINS THE COLDEST MODEL...WITH THE GFS QUITE A BIT MILDER. WILL CONTINUE TO STAY SOMEWHERE IN THE MIDDLE OF THESE TWO EXTREME SOLUTIONS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 645 PM EST MON JAN 11 2016 VFR CONDITIONS WILL BE IN PLACE FOR MOST OF THE NIGHT BEFORE A QUICK CLIPPER SYSTEM MOVES INTO EASTERN KENTUCKY TOMORROW MORNING AND INTO THE AFTERNOON. EXPECT REDUCED VISIBILITY AND MVFR CIGS AT SYM AND SJS TOMORROW AFTERNOON. EXPECT ONLY MVFR CIGS AT JKL...LOZ AND SME TOMORROW AFTERNOON. WINDS WILL BE LIGHT TO START THE PERIOD BEFORE SHIFTING TO THE WEST AND NORTHWEST TOMORROW AFTERNOON AND INCREASING TO 10 TO 18 KNOTS WITH GUSTS REACHING 30 KNOTS IN SOME LOCATIONS. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 5 AM TO 7 PM EST TUESDAY FOR KYZ044- 050>052-058>060-068-069-079-080. WINTER WEATHER ADVISORY FROM 7 AM TO 11 PM EST TUESDAY FOR KYZ086>088-104-106>120. && $$ UPDATE...SHALLENBERGER SHORT TERM...JP LONG TERM...KAS AVIATION...SHALLENBERGER
  [top] Area Forecast Discussion National Weather Service Louisville KY 1003 PM EST MON JAN 11 2016 ...Forecast Update... Updated 1000 PM EST Mon Jan 11 2016 Updated the forecast to account for the latest trends this evening. Current radar imagery continues to show rather widespread echoes from portions of western KY northeastward into southern IN and Ohio. However, the 12/00Z ILN sounding depicted a few dry layers, one below 900mb and another one between 500-700mb. This dry air is likely even more pronounced over our region, thus these echoes have struggled to reach the ground. Therefore, don`t think we will see much more than some scattered flurries through about 6Z, with perhaps a localized snow shower in a heavier echo (like we are seeing currently over Hancock/Perry counties). Otherwise, the main show will come Tuesday morning. The latest guidance continues to trend slower with the accumulating snowfall potential, thus have delayed the higher pops from the previous forecast. The latest NAM has trended further north with the better snow amounts/snow burst potential. However, the latest HRRR runs continue to show accumulations likely approaching an inch as far south as a line form Ohio to Casey County, KY. Synoptically, the best PV advection will remain well north of I-64 as will the best low-level lapse rates/instability indices. Therefore, am not sold on the more southern HRRR solution. Will lean more towards the NAM solution which overall lowers amounts slightly across the region. However, do not want to cancel any headlines given the HRRR solution and the fact that any snowfall will accumulate given cold road temps, so will leave the Advisory as is for now. Updated products/maps will be out shortly. .SHORT TERM (Now through Tuesday Night)... Issued at 335 PM EST Mon Jan 11 2016 In the near term, high pressure over the southeastern US will continue to keep us dry this afternoon and evening. Temperatures across the region have warmed into the upper 20s in the far north to the middle-upper 30s across the south/southwestern sections. This evening will be dry with temperatures falling back into the upper 20s to around 30. Normally one would expect a sharper fall off in temperatures, but we`ll have a southwesterly wind that will keep temperatures up or at least hold steady through the evening hours. For tonight, all eyes will be on a weak clipper system that will be moving in tandem with a southward moving arctic cold front. This will result in a low pressure system moving through the Great Lakes with the cold front pushing through the Ohio Valley on Tuesday. Snow is expected to develop ahead of this system aided by isentropic lift ahead of the frontal system. Snow is likely to break out late this evening across southern IL and SW IN. This activity should move into our NW areas after 12/06Z. The snow should expand in coverage late tonight and then push into north-central KY toward dawn and then into central Kentucky during the morning and afternoon hours on Tuesday. The latest guidance is largely an extension of the 11/00Z and 06Z guidance. The best forcing still looks to largely reside across the northern half of our region. Combination of the small 500 hPa jet max crossing the region and a slightly stronger band of frontogenetical forcing will result in an expansion of snow shower activity Tuesday morning and afternoon. Model proximity soundings do show steepening low-level lapse rates during the day, so some intense snow showers and/or squalls may develop. A rumble of thunder is certainly not out of the question. The synoptic scale models continue to produce light QPF amounts, but we feel that these are slightly underdone given the expected convective nature of the snow shower activity. In addition, we could see some E-W banded snow showers set up...mainly across SE IN and into the northern Bluegrass region Tuesday morning. A general snowfall of 1 to 3 inches still looks likely across the northern half of the forecast area. Unlike more dynamic systems found across the region during the winter, a uniform snow does not look likely. Instead, the showery aspect of the storm will likely result in varying snowfall amounts over small distances. In areas that see repeated snow showers move through...or end up some banding feature, isolated amounts of up to 4 inches are not out of the question. In addition to the snow, winds will pick up dramatically and will likely gust into the 30-35 MPH range. This will result in blowing snow at times and reduced visibility. After evaluating the morning and afternoon datasets and collaborating with surrounding offices, a Winter Weather Advisory has been issued for late tonight through Tuesday for all of southern Indiana and much of northern KY. The snowfall is expected to negatively impact travel during the morning commute and during the day on Tuesday. Motorists should expect travel problems in the morning and allow extra time to reach destinations. Highs on Tuesday will range from the upper 20s int he north to the middle 30s along the KY/TN state line. Temperatures will fall during the late afternoon and evening hours. Lows tomorrow night will be dependent on snow cover and sky cover. If skies clear out, single digit readings across the north will be attainable with other areas seeing lows in the lower teens. .LONG TERM (Wednesday through Monday)... Issued at 405 PM EST Mon Jan 11 2016 Upper trough axis will shift eastward during the day on Wednesday. A second but weaker impulse aloft will cruise through the region during the day on Wednesday may produce a few flurries as it pushes through. After that passes, mid-level ridging will build into the region and we`ll see temperatures moderate as we move through Thursday and into Friday. Highs Wednesday will warm into the mid- upper 20s in the north with upper 20s to lower 30s across the central sections and mid 30s down across southern KY. Lows Wednesday night will cool back into the lower-mid 20s and highs on Thursday look to warm into the middle 40s in the north with upper 40s to lower 50s across the south. The quiet and milder weather will not last long through. By Thursday night, a mid-level wave will spawn an area of surface low pressure over the Mid-Mississippi valley. This feature will quickly race to the northeast bringing a round of rain showers to the region during the day on Friday and into Friday night. The low pressure system looks to pass through the region Friday night and will be exiting our region by Saturday morning. Colder air will wrap back down into the region on Saturday resulting in some light rain/snow showers depending on how fast the lower atmosphere cools. A second, but stronger trough axis will then drop into the region Saturday night resulting in some more snow showers for Saturday evening and overnight into Sunday. For Sunday and Monday, deep 500 hPa closed low will drop into the Great Lakes and then move into southern New England by Monday. A strong northwesterly flow will push very cold Arctic air into region during the period. We have lowered temperatures quite a bit for Sunday with highs in the lower 20s in the north and upper 20s in the south. The SuperBlend guidance is likely going to play catch up here and the next load of it will likely push temps down into the teens for highs on Sun/Mon with overnight lows in the single digits. && .AVIATION (00Z TAF Update)... Updated at 620 PM EST Mon Jan 11 2016 VFR conditions will persist through much of the night. However, conditions will begin to quickly deteriorate a few hours on either side of sunrise tomorrow mainly at LEX/SDF as a quick-hitting system brings snow to the region. Much of the light to moderate snow will hold off until around 11Z at SDF and around 13Z at LEX. There may be some flurries before then, but the atmosphere should take a bit to saturate. It appears that a thin line of more intense snow bursts will be at SDF between 13-17Z and LEX between 15-19Z right along a strong cold front. It is within this line that vsbys will likely be reduced to low-end IFR or even lower for a brief period of time. Therefore, will include a TEMPO group to account for these. Just ahead and especially behind the front is when westerly winds will be the highest, with gusts around 30 knots for a few hours. While BWG will remain out of the heavier snows, gusts of 25-30 knots will still be likely along the front tomorrow afternoon. && .LMK Watches/Warnings/Advisories... KY...Winter Weather Advisory until 4 PM EST /3 PM CST/ Tuesday for KYZ023>025-028>034-038-045-053. Winter Weather Advisory from 5 AM to 7 PM EST Tuesday for KYZ035>037-039>043-046>049-054>057-065>067. IN...Winter Weather Advisory until 4 PM EST /3 PM CST/ Tuesday for INZ076>079-083-084-089>092. && $$ Update.........KJD Short Term.....MJ Long Term......MJ Aviation.......KJD
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1144 AM CST SUN JAN 10 2016 .UPDATE... Issued at 1140 AM CST SUN JAN 10 2016 For aviation section only. UPDATE Issued at 510 AM CST SUN JAN 10 2016 Aviation update. && .SHORT TERM...(Today through Tuesday night) Issued at 247 AM CST SUN JAN 10 2016 Just made a few last minute adjustments to added snow flurries (trace precipitation) with the approaching cold air stratocumulus working in behind the upper trough and deformation zone. This trace precipitation may diminish be 16z, but decided to keep a mention in part of the WFO PAH forecast area through 18z (noon). The Winter Weather Advisory looks to be on track for expiration at 10z (4 am CST), with the possible exception of the last row of counties from Spencer County IN, down to Todd County KY. Snowfall production should be diminishing markedly by that time, so will not extend the Advisory beyond its scheduled expiration. Radar trends from the KVWX radar suggest the lift/forcing tied to the deformation zone is beginning to lift northeast and should lessen the overall snow production, especially since the favored dendritic growth zone temperature profile is also shifting northeast per the RAP guidance. Know that there is some snow cover in place, made a few minor temperature adjustments to reflect the impact of the snow cover for Sunday night and into Monday. It may not be enough, but attempted to reflect the impact of the snow cover during insolation (sunshine) and longwave/shortwave radiation at night. The ECMWF and NMM Version of the NAM-WRF, and to a lesser extent the Canadian handle the next shortwave clipper moving out of central Canada late Monday Night into Tuesday across the WFO PAH forecast area. Most of the numerical model suite has been keying in on this feature since late last week. Temperature profiles should keep the precipitation in the form of snow. Given the lower moisture availability and higher snow to liquid ratios, snowfall amounts should hold between one quarter and three quarters of an inch by Tuesday morning over Southwest Indiana, Northwest Kentucky, and small part of Southeast Illinois. Dry conditions and below normal temperatures will dominate the rest of the forecast period. .LONG TERM...(Wednesday through Saturday) Issued at 247 AM CST SUN JAN 10 2016 Will use a deterministic GFS/ECMWF blend 12z Wed through 12z Thur, then a blend of the 00z GEFS and 12z ECENS will be used from 12z Thur through Saturday. Too much forecast spread and run to run consistency issues with energies within the overall mid tropospheric flow to utilize the ops models too much. High pressure will move east with dry weather the rule Wednesday through Thursday. Will carry a slight chance of R-/S- Friday through Saturday as the mean mid trop trof moves east from the nation`s mid section to our area. Changing thermal profile forecast and uncertainty means we will keep wording generic. Temps will be a blend of ensemble MOS and deterministic model output. && .AVIATION... Issued at 1140 AM CST SUN JAN 10 2016 1500 FT to 2500 FT MVFR cigs can be expected over snow covered areas (KPAH/KEVV/KOWB) during the day along with gusty wnw winds 15-20 KTS. Should be clear with light winds after 22Z. && .PAH Watches/Warnings/Advisories... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...GM AVIATION...GM
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1104 AM EST SUN JAN 10 2016 .UPDATE... ISSUED AT 1103 AM EST SUN JAN 10 2016 POPS AND HOURLY TEMPERATURES HAVE BEEN UPDATED BASED ON RECENT OBSERVATIONS AND RADAR TRENDS. A COUPLE OF BANDS OF SNOW SHOWERS ARE WORKING ACROSS THE EASTERN AND SOUTHEAST COUNTIES...FROM BREATHITT TO PIKE COUNTY AS WELL AS SOUTH OF KY HIGHWAY 80. THE NORTHERN ONE HAS PRODUCED A DUSTING OF SNOW VISIBLE A FEW MILES SOUTH OF JKL. HOWEVER...NO MORE THAN FLURRIES HAVE OCCURRED HERE SO FAR. BASED ON JKL AND UPSTREAM OBS AND RADARS...SNOW SHOWERS SHOULD DIMINISH THROUGH MIDDAY...AND FLURRIES SHOULD OCCUR OFF AND ON THROUGH LATE AFTERNOON OR EVENING UNTIL THE LOW CLOUDS BREAK UP. TEMPERATURES AT THIS POINT HAVE FALLEN INTO THE 25 TO 35 DEGREE RANGE ACROSS THE AREA AND WITH CONTINUED COLD ADVECTION THIS AFTERNOON...TEMPERATURES WILL FALL INTO THE 20S. THE HIGHER TERRAIN ABOVE 2500 FEET MAY REACH THE TEENS BEFORE DARK. UPDATE ISSUED AT 642 AM EST SUN JAN 10 2016 WSR-88D RADAR CONTINUES TO SHOW AREAS OF LIGHT TO MODERATE RAIN SHOWERS MOVING NORTHEAST ACROSS PORTION OF THE REGION THIS MORNING...WHILE AS YOU MOVE SW TOWARD THE CUMBERLAND VALLEY REGION RAIN SHOWERS HAVE TRANSITIONED TO SNOW SHOWERS THIS HOUR. THESE ARE NOT VERY EVIDENT ON RADAR AND LIKELY A RESULT OF OVERSHOOTING. THE TEMPS WILL FALL QUICKLY THROUGH THE MORNING FROM WEST TO EAST FOR EXAMPLE AT SME TEMPS FELL FROM 45 DEGREES AT 9Z...TO 37 DEGREES AT 10Z...TO 32 DEGREES BY 11Z. THEREFORE DID OPT TO UPDATE TEMP CURVE TO CAPTURE THE LATEST OBS AND TRENDS. ALSO UPDATED THE WX GRIDS TO TRY AND CAPTURE THE TRANSITION ZONE. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 402 AM EST SUN JAN 10 2016 A SURFACE LOW AND A NEGATIVELY TILTED UPPER LEVEL TROUGH WILL CONTINUE TO TRACK ACROSS KY AND OH VALLEY THIS MORNING. WSR-88D RADAR SHOWS THE BACK EDGE OF THE FIRST BAND OF LIGHT TO MODERATE RAIN ON A LINE FROM CUMBERLAND...TO HAZARD...TO JACKSON...TO CAMPTON...TO FLEMINGSBURG AND THIS WILL CONTINUE TO TRACK NE THROUGH THE MORNING. BEHIND THIS WE ARE SEEING AREAS GETTING INTO A DRY SLOT EVIDENT ON RADAR AND WATER VAPOR IMAGERY THIS MORNING. NOW THE ACTIVITY ACROSS MIDDLE TN AND CENTRAL/WESTERN KY IS AREA THAT HAS SEEN A MIX OR CHANGE OVER TO ALL SNOW OVERNIGHT. THE STORM SCALE MODELS DO SLIDE THIS INTO THE SW PORTIONS OF THE CWA BY 10Z TO 11Z AND THEREFORE OPTED TO EXTEND THE SPS SOUTH GIVEN THE TRENDS. THOSE AREAS AND AREAS FURTHER NORTH ALONG AND NEAR I-64 CORRIDOR STAND THE BEST CHANCES OF SEEING A QUICK HALF OF INCH OF SNOW IN SOME OF THE HEAVIER BANDS. NOW THE QUESTION REMAINS FOR THE REMAINDER OF THE DAY...WINDS REMAIN OUT OF THE WEST BASED ON MOST THE GUIDANCE...SO HAVE DOUBTS THAT THIS WILL LEAD TO MUCH UPSLOPE. DID GENERALLY TREND AMOUNTS DOWN ACROSS THIS PORTION OF THE REGION AND ALSO TRENDED POPS DOWN. NOW DEEP MIXING HEIGHTS AND STRONG PRESSURE GRADIENT IN PLACE TODAY WILL LEAD TO GUSTY WEST WINDS THROUGH THE DAY. THESE WINDS COULD LEAD TO REDUCTIONS IN VIS IN HEAVIER SNOW SHOWERS. THESE WINDS WILL ALSO AID IN ADVECTING MUCH COLDER AIR INTO THE REGION THROUGH THE DAY AND THEREFORE STUCK TO A MORE UNORTHODOX TEMPERATURE CURVE. TEMPS WILL FALL FROM THE MID TO UPPER 40S THIS MORNING TO THE MID TO UPPER 20S BY THE AFTERNOON. TONIGHT LINGERING FLURRY IS POSSIBLE EARLY IN THE EVENING ALONG THE HIGHER TERRAIN NEAR THE VA BORDER...AS MOISTURE CONTINUES TO BECOME MORE AND MORE SHALLOW. OTHERWISE WE WILL SEE CLEARING SKIES THROUGH THE NIGHT...WITH TEMPS DROPPING INTO THE MID TO UPPER TEENS AS -8 TO -10 CELSIUS 850MB TEMPS PASS OVER HEAD. FOR MONDAY HIGH PRESSURE WILL PASS TO THE SOUTH WITH COLD AIR LOCKED IN PLACE ACROSS EASTERN KY. THIS WILL BRING MOSTLY SUNNY SKIES AND TEMPS TOPPING OUT IN THE LOWER 30S FOR MOST SPOTS. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 450 AM EST SUN JAN 10 2016 COMPARED TO LAST NIGHT THE MODELS ARE IN BETTER AGREEMENT ALOFT THROUGH THE BULK OF THE EXTENDED PORTION OF THE FORECAST BUT THAT CONSENSUS SLIPS SOMEWHAT TOWARD THE END OF THE WEEK. THEY ALL DEPICT A NORTHERN STREAM FLOW PATTERN DOMINATED AT THE BEGINNING BY A DEEP TROUGH OVER THE GREAT LAKES THAT WILL SWING ITS CORE ENERGY THROUGH THE SOUTHERN OHIO VALLEY ON TUESDAY. THIS ALL STARTS TO SHIFT EAST BY MID WEEK...THOUGH. DESPITE THE RISING HEIGHTS FOR THE OHIO VALLEY IN ITS WAKE...A WEAKER AND SMALLER TROUGH WILL DIVE SOUTHEAST THROUGH THE AREA IN NORTHWEST FLOW AND THIS SEEMS TO JUMBLE THE FLOW PATTERN FOR THE REGION IN THE VARIOUS MODELS. THE SOUTHERN STREAM BECOMES MORE ACTIVE FOR OUR AREA...BRINGING A WAVE INTO THE SOUTHERN PLAINS ON FRIDAY AND EAST INTO KENTUCKY FOR SATURDAY. THE ECMWF...AS IT WAS LAST NIGHT...IS MOST CLEAR WITH THIS WEEKEND WAVE THAN THE GFS...BUT THE LATTER IS TRENDING TOWARD THE FORMER. THIS LENDS SOME SLOWLY INCREASING CONFIDENCE TO THE TIMING AND TRACK OF THE SYSTEM ANTICIPATED FOR LATE IN THE EXTENDED. AGAIN THE GENERAL MODEL BLEND LOOKS REASONABLE FOR THE ENTIRE EXTENDED GIVEN THE SIMILARITIES THROUGH MID WEEK AND A CONVERGING SCENARIO AT THE END. SENSIBLE WEATHER WILL FEATURE A DYNAMIC DAY OF SNOW SHOWERS AND SQUALLS ANTICIPATED FOR TUESDAY AS A COLD FRONT SWINGS INTO THE STATE IN CONJUNCTION WITH A DEEPENING PARENT LOW OVER THE EASTERN LAKES. THIS FRONT WILL TAP INTO SOME DEEPER MOISTURE WHILE BRINGING ANOTHER SHOT OF ARCTIC AIR TO EASTERN KENTUCKY. AS A RESULT...THE MOISTURE WITH THESE SNOW SHOWERS WILL REACH INTO THE FAVORED DENDRITIC ZONE AND COULD LEAD TO QUICK...BUT BRIEF AND STILL RATHER LIGHT...SNOW ACCUMULATIONS ALONG WITH GUSTY WINDS. IN GENERAL LESS THAN AN INCH OF ACCUMULATION CAN BE EXPECTED... THOUGH PERHAPS A TAD HIGHER NORTH OF INTERSTATE 64...BUT WITH COLDER TEMPERATURES IN PLACE AHEAD OF IT...AND ITS SQUALLY NATURE...THIS SYSTEM WILL LIKELY BE OF MORE IMPACT FOR THE AREA THAN WHAT WE WILL SEE TODAY. GIVEN THE ONGOING RAIN TO SNOW SITUATION HAVE MAINLY JUST HIT THE TUESDAY THREAT HARD IN THE HWO BUT AN SPS OR MORE MAY BE NEEDED BY MONDAY. HIGH PRESSURE WILL PASS THROUGH THE AREA FOR WEDNESDAY INTO FRIDAY WITH SOME MODERATION TAKING PLACE WITH THE TEMPERATURES. HOWEVER...A SOUTHERN...AND POTENTIALLY COASTAL...SYSTEM WILL TAKE SHAPE EITHER OVERHEAD OR JUST TO THE SOUTH OF EASTERN KENTUCKY ON SATURDAY WITH ANOTHER ROUND OF SHOWERS ANTICIPATED ALONG WITH THE POTENTIAL OF BACKSIDE SNOW AND MORE ARCTIC COLD LATER IN THE WEEKEND. WE WILL BE CLOSELY WATCHING AS THIS SYSTEM TRIES TO TAKE SHAPE IN THE MODELS OVER THE COMING DAYS. AGAIN ADJUSTED THE GRIDS FROM THE CR INIT MAINLY TO ACCOUNT FOR SMALL RIDGE TO VALLEY TEMPERATURE DIFFERENCES THROUGH THE PERIOD. ALSO TWEAKED THE POP GRIDS LATE IN THE PERIOD TO BETTER REFLECT THE GROWING STORM POTENTIAL FOR NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 628 AM EST SUN JAN 10 2016 WSR-88D CONTINUES TO SHOW BANDS OF LIGHT TO MODERATE RAIN SHOWERS PASSING THROUGH THE REGION THIS MORNING. THESE WILL AID IN LOWERING VIS AND CIGS THROUGH THE EARLY MORNING. RESULTING IN MOST SITES SEEING MVFR TO IFR RANGE CIGS. COLD AIR WILL CONTINUE TO INVADE THE REGION FROM WEST TO EAST THROUGH THE MORNING WITH SME ALREADY REPORTING SNOW. THESE DROPS SHOULD CONTINUE AND AS WE DO EXPECT ANY LEFT OVER SHOWERS TO CONTINUE TO TRANSITION TO SNOW SHOWERS THROUGH THE MORNING. SOME OF THESE SNOW SHOWERS COULD CAUSE QUICK REDUCTIONS IN THE VIS. BASED ON GUIDANCE THIS SHOWER ACTIVITY BEHIND THIS SYSTEM WILL DECLINE THROUGH THE DAY...AND WE ARE EXPECTED TO SEE IMPROVEMENTS IN THE AFTERNOON AND EVENING HOURS RELATED TO CIGS. OTHER ISSUE WILL BE GUSTY WEST WINDS WITH SITES SEEING MAX GUSTS IN THE 25 TO 30 KNOT RANGE...BUT THESE SHOULD DIE DOWN TONIGHT AS PRESSURE GRADIENT RELAXES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...DJ LONG TERM...GREIF AVIATION...DJ
Area Forecast Discussion National Weather Service Louisville KY 941 AM EST SUN JAN 10 2016 ...Forecast Update... Updated 940 AM EST Sun Jan 10 2016 Will go ahead and hold onto the WSW to 17Z and let expire at that point. Still have some light snows falling, but the bigger concern now are some iced-up roads where the heavy snow had fallen. Had a few reports of 2-4 inch totals. Rest of the region is under a special weather statement for these slick spots as well as the cold wind chills and will keep that going as well. Updated at 835 AM EST Sun Jan 10 2016 Main band of heavy snow has weakened and is almost out of our forecast area. Still have some light returns upstream that could measure as a tenth of snow, so added in isolated snow showers behind the line through the morning. Cannot rule out an additional flurry this afternoon in any convective showers. As for the winter weather advisory, will leave in place probably to 15Z and then pull it. Heaviest snows are over, just may have some blowing of fallen snow/slick roads for a couple more hours. Updated at 604 AM EST Sun Jan 10 2016 Surface low has rapidly moved into west central Ohio, and frontogenetical band will continue to slowly weaken as it pivots across mainly the NW half our CWA through mid to late morning. Have picked up several reports of 1 to 2 inches along and north of the Ohio River, and expect that many areas just south of the river will end up with at least an inch. Winds are gusting to between 25 and 35 mph at times, which could blow what snow accumulates around. Additionally, temps are crashing with western portions of our CWA already down into the low and mid 20s. As temps fall into the teens west of I-65 over the next several hours, wind chill values will drop as low a -3 to 10 above zero. Have dropped the Winter Weather Advisory down across our far SW where frontogenetical band fell apart before more than a dusting could fall. Have alse dropped the western tier of the advisory where snow has stopped falling. Replaced this area with a Special Weather Statement for slick roads, some blowing snow, and bitter wind chills. .SHORT TERM (Now through Monday)... Issued at 315 AM EST Sun Jan 10 2016 ...Light Accumulating Snow and Gusty Winds Today... Surface low has rapidly lifted NE out of our CWA over the past hour and will make it`s way to the Ontario/Quebec border by this evening. Meanwhile, strong surface cold front has pushed east of a BWG to SDF line and will advance east of our CWA before sunrise. Temps are crashing behind the front, as HNB is already at freezing. Rain/snow change over line now stretches from BWG up through Salem Indiana and will continue to rapidly push east through the pre-dawn hours. Expecting the Louisville metro area to change over to snow between 3 and 4 AM EST, and the Lexington metro between 5 and 6 AM EST. There could be a brief period of sleet with the changeover (recently reported by a spotter near BWG), however this will be of no consequence and very short lived as the low level thermodynamic profile crashes and quickly changes to snow. Overall, see no reason to change to the ongoing forecast as deformation band slides through the region. It should gradually weaken as the surface low moves NE and some frontogenesis is lost. Additionally, dry air will begin to cut off deep moisture. However, with the band pivoting and then lifting over the area along a generally constant axis, residence time will be enough to realize accums. So, will keep going Winter Weather Advisory in place, with a general 1 to 2 inches in most spots. Our far NW is more likely to see 2 to 3 inches, with the far SE part of the advisory more in the half to 1 inch range. Outside of the advisory, a dusting to a half an inch is possible. Impacts should be somewhat mitigated by the warm road/ground temps, which will limit most accums to grassy/elevated surfaces. However snowfall rates and persistence should be enough to allow for some minor road accums at times. Winds will also gust up around 25-35 mph at times so visibilities could be reduced. Big change in the short term is really with temps as HRRR continues to handle the Arctic airmass well. It brings mid and upper teens into our West later this morning, which will yield wind chill values down around zero. Use caution if traveling our expected to be outside. Otherwise, snow showers taper off in the Blue Grass region around midday, with temps staying in the teens in our west and falling through the 20s east. With gusty west winds continuing, wind chills will stay in the single digits to lower teens. Tonight - Monday... Dry and cold conditions then take over for tonight and Monday as the Arctic surface high settles to our south, and benign NW flow aloft rules our upper air pattern. Look for lows tonight in the 10 to 15 degree range. Highs on Monday should recover to the 28-35 range as light SW flow returns on the back side of the surface high. .LONG TERM (Monday Night through Saturday)... Issued at 315 AM EST Sun Jan 10 2016 Monday Night - Tuesday... ...Confidence Growing for Intense Snow Shower Potential Tuesday Morning... A strong PV anomaly and associated surface low will slide across the Great Lakes late Monday night into Tuesday. Another Arctic front will trail from this system, sliding through our CWA Tuesday morning through the early afternoon. Pretty concerned about the potential for intense snow showers with this system along and north of I-64 likely during the morning commute. Low and mid level lapse rates steepen dramatically to the point where some instability will likely be available. This combined with saturation up through the DGZ would be enough to warrant scattered to numerous intense snow showers. The bulk of these would fall from the pre-dawn hours through about midday along and north of I-64. If data holds, these types of scenarios can produce light but very quick accumulations that make travel extremely hazardous, especially at highway/interstate speeds because rapid accumulations occur over short distances. Additionally, gusty winds between 30 and 40 mph appear to be possible which would reduce visibilities even more. Tuesday Night - Thursday Night... Arctic surface high builds in Tuesday night along with dry NW flow aloft. This pattern will dominate sensible weather through mid week resulting in initial cold, but moderating temps. We`ll also be dry. Lows Tuesday night should once again fall into the 10 to 15 degree range in most spots, with wind chills likely in the 0 to 10 range. Highs Wednesday recover into the mid/upper 20s and low 30s. Southerly flow returns and brings slightly milder lows Wednesday night. Look for the 20 to 25 degree range in most spots. Cool valley, especially in the east, will drop to the mid/upper teens. Thursday brings temps back into the low and mid 40s. Lows will be around 30 Thursday Night. Friday - Saturday... Low confidence for this period as models diverge in a complex pattern. Overall this will be a cooler/wetter period with chances for rain and snow. && .AVIATION (12Z TAF Update)... Updated at 619 AM EST Sun Jan 10 2016 Snow will be east of BWG by 12Z and will end at SDF right around the beginning of the TAF period. The band of snow will move through LEX, tapering off around 14Z-1430Z. Behind the snow, low clouds will persist through the rest of the daylight hours just under fuel alternate but above IFR. Those low clouds will clear out as high pressure moves in from the west this evening. West winds will be gusty today, and will quickly settle down with sunset this evening. && .LMK Watches/Warnings/Advisories... KY...Winter Weather Advisory until noon EST today for KYZ025-028>035- 038-045-053. IN...Winter Weather Advisory until noon EST today for INZ077>079- 090>092. && $$ Updates........RJS/BJS Short Term.....BJS Long Term......BJS Aviation.......13
AREA FORECAST DISCUSSION
NWS JACKSON KY
628 AM EST SUN JAN 10 2016 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 402 AM EST SUN JAN 10 2016 A SURFACE LOW AND A NEGATIVELY TILTED UPPER LEVEL TROUGH WILL CONTINUE TO TRACK ACROSS KY AND OH VALLEY THIS MORNING. WSR-88D RADAR SHOWS THE BACK EDGE OF THE FIRST BAND OF LIGHT TO MODERATE RAIN ON A LINE FROM CUMBERLAND...TO HAZARD...TO JACKSON...TO CAMPTON...TO FLEMINGSBURG AND THIS WILL CONTINUE TO TRACK NE THROUGH THE MORNING. BEHIND THIS WE ARE SEEING AREAS GETTING INTO A DRY SLOT EVIDENT ON RADAR AND WATER VAPOR IMAGERY THIS MORNING. NOW THE ACTIVITY ACROSS MIDDLE TN AND CENTRAL/WESTERN KY IS AREA THAT HAS SEEN A MIX OR CHANGE OVER TO ALL SNOW OVERNIGHT. THE STORM SCALE MODELS DO SLIDE THIS INTO THE SW PORTIONS OF THE CWA BY 10Z TO 11Z AND THEREFORE OPTED TO EXTEND THE SPS SOUTH GIVEN THE TRENDS. THOSE AREAS AND AREAS FURTHER NORTH ALONG AND NEAR I-64 CORRIDOR STAND THE BEST CHANCES OF SEEING A QUICK HALF OF INCH OF SNOW IN SOME OF THE HEAVIER BANDS. NOW THE QUESTION REMAINS FOR THE REMAINDER OF THE DAY...WINDS REMAIN OUT OF THE WEST BASED ON MOST THE GUIDANCE...SO HAVE DOUBTS THAT THIS WILL LEAD TO MUCH UPSLOPE. DID GENERALLY TREND AMOUNTS DOWN ACROSS THIS PORTION OF THE REGION AND ALSO TRENDED POPS DOWN. NOW DEEP MIXING HEIGHTS AND STRONG PRESSURE GRADIENT IN PLACE TODAY WILL LEAD TO GUSTY WEST WINDS THROUGH THE DAY. THESE WINDS COULD LEAD TO REDUCTIONS IN VIS IN HEAVIER SNOW SHOWERS. THESE WINDS WILL ALSO AID IN ADVECTING MUCH COLDER AIR INTO THE REGION THROUGH THE DAY AND THEREFORE STUCK TO A MORE UNORTHODOX TEMPERATURE CURVE. TEMPS WILL FALL FROM THE MID TO UPPER 40S THIS MORNING TO THE MID TO UPPER 20S BY THE AFTERNOON. TONIGHT LINGERING FLURRY IS POSSIBLE EARLY IN THE EVENING ALONG THE HIGHER TERRAIN NEAR THE VA BORDER...AS MOISTURE CONTINUES TO BECOME MORE AND MORE SHALLOW. OTHERWISE WE WILL SEE CLEARING SKIES THROUGH THE NIGHT...WITH TEMPS DROPPING INTO THE MID TO UPPER TEENS AS -8 TO -10 CELSIUS 850MB TEMPS PASS OVER HEAD. FOR MONDAY HIGH PRESSURE WILL PASS TO THE SOUTH WITH COLD AIR LOCKED IN PLACE ACROSS EASTERN KY. THIS WILL BRING MOSTLY SUNNY SKIES AND TEMPS TOPPING OUT IN THE LOWER 30S FOR MOST SPOTS. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 450 AM EST SUN JAN 10 2016 COMPARED TO LAST NIGHT THE MODELS ARE IN BETTER AGREEMENT ALOFT THROUGH THE BULK OF THE EXTENDED PORTION OF THE FORECAST BUT THAT CONSENSUS SLIPS SOMEWHAT TOWARD THE END OF THE WEEK. THEY ALL DEPICT A NORTHERN STREAM FLOW PATTERN DOMINATED AT THE BEGINNING BY A DEEP TROUGH OVER THE GREAT LAKES THAT WILL SWING ITS CORE ENERGY THROUGH THE SOUTHERN OHIO VALLEY ON TUESDAY. THIS ALL STARTS TO SHIFT EAST BY MID WEEK...THOUGH. DESPITE THE RISING HEIGHTS FOR THE OHIO VALLEY IN ITS WAKE...A WEAKER AND SMALLER TROUGH WILL DIVE SOUTHEAST THROUGH THE AREA IN NORTHWEST FLOW AND THIS SEEMS TO JUMBLE THE FLOW PATTERN FOR THE REGION IN THE VARIOUS MODELS. THE SOUTHERN STREAM BECOMES MORE ACTIVE FOR OUR AREA...BRINGING A WAVE INTO THE SOUTHERN PLAINS ON FRIDAY AND EAST INTO KENTUCKY FOR SATURDAY. THE ECMWF...AS IT WAS LAST NIGHT...IS MOST CLEAR WITH THIS WEEKEND WAVE THAN THE GFS...BUT THE LATTER IS TRENDING TOWARD THE FORMER. THIS LENDS SOME SLOWLY INCREASING CONFIDENCE TO THE TIMING AND TRACK OF THE SYSTEM ANTICIPATED FOR LATE IN THE EXTENDED. AGAIN THE GENERAL MODEL BLEND LOOKS REASONABLE FOR THE ENTIRE EXTENDED GIVEN THE SIMILARITIES THROUGH MID WEEK AND A CONVERGING SCENARIO AT THE END. SENSIBLE WEATHER WILL FEATURE A DYNAMIC DAY OF SNOW SHOWERS AND SQUALLS ANTICIPATED FOR TUESDAY AS A COLD FRONT SWINGS INTO THE STATE IN CONJUNCTION WITH A DEEPENING PARENT LOW OVER THE EASTERN LAKES. THIS FRONT WILL TAP INTO SOME DEEPER MOISTURE WHILE BRINGING ANOTHER SHOT OF ARCTIC AIR TO EASTERN KENTUCKY. AS A RESULT...THE MOISTURE WITH THESE SNOW SHOWERS WILL REACH INTO THE FAVORED DENDRITIC ZONE AND COULD LEAD TO QUICK...BUT BRIEF AND STILL RATHER LIGHT...SNOW ACCUMULATIONS ALONG WITH GUSTY WINDS. IN GENERAL LESS THAN AN INCH OF ACCUMULATION CAN BE EXPECTED... THOUGH PERHAPS A TAD HIGHER NORTH OF INTERSTATE 64...BUT WITH COLDER TEMPERATURES IN PLACE AHEAD OF IT...AND ITS SQUALLY NATURE...THIS SYSTEM WILL LIKELY BE OF MORE IMPACT FOR THE AREA THAN WHAT WE WILL SEE TODAY. GIVEN THE ONGOING RAIN TO SNOW SITUATION HAVE MAINLY JUST HIT THE TUESDAY THREAT HARD IN THE HWO BUT AN SPS OR MORE MAY BE NEEDED BY MONDAY. HIGH PRESSURE WILL PASS THROUGH THE AREA FOR WEDNESDAY INTO FRIDAY WITH SOME MODERATION TAKING PLACE WITH THE TEMPERATURES. HOWEVER...A SOUTHERN...AND POTENTIALLY COASTAL...SYSTEM WILL TAKE SHAPE EITHER OVERHEAD OR JUST TO THE SOUTH OF EASTERN KENTUCKY ON SATURDAY WITH ANOTHER ROUND OF SHOWERS ANTICIPATED ALONG WITH THE POTENTIAL OF BACKSIDE SNOW AND MORE ARCTIC COLD LATER IN THE WEEKEND. WE WILL BE CLOSELY WATCHING AS THIS SYSTEM TRIES TO TAKE SHAPE IN THE MODELS OVER THE COMING DAYS. AGAIN ADJUSTED THE GRIDS FROM THE CR INIT MAINLY TO ACCOUNT FOR SMALL RIDGE TO VALLEY TEMPERATURE DIFFERENCES THROUGH THE PERIOD. ALSO TWEAKED THE POP GRIDS LATE IN THE PERIOD TO BETTER REFLECT THE GROWING STORM POTENTIAL FOR NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 628 AM EST SUN JAN 10 2016 WSR-88D CONTINUES TO SHOW BANDS OF LIGHT TO MODERATE RAIN SHOWERS PASSING THROUGH THE REGION THIS MORNING. THESE WILL AID IN LOWERING VIS AND CIGS THROUGH THE EARLY MORNING. RESULTING IN MOST SITES SEEING MVFR TO IFR RANGE CIGS. COLD AIR WILL CONTINUE TO INVADE THE REGION FROM WEST TO EAST THROUGH THE MORNING WITH SME ALREADY REPORTING SNOW. THESE DROPS SHOULD CONTINUE AND AS WE DO EXPECT ANY LEFT OVER SHOWERS TO CONTINUE TO TRANSITION TO SNOW SHOWERS THROUGH THE MORNING. SOME OF THESE SNOW SHOWERS COULD CAUSE QUICK REDUCTIONS IN THE VIS. BASED ON GUIDANCE THIS SHOWER ACTIVITY BEHIND THIS SYSTEM WILL DECLINE THROUGH THE DAY...AND WE ARE EXPECTED TO SEE IMPROVEMENTS IN THE AFTERNOON AND EVENING HOURS RELATED TO CIGS. OTHER ISSUE WILL BE GUSTY WEST WINDS WITH SITES SEEING MAX GUSTS IN THE 25 TO 30 KNOT RANGE...BUT THESE SHOULD DIE DOWN TONIGHT AS PRESSURE GRADIENT RELAXES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DJ LONG TERM...GREIF AVIATION...DJ
Area Forecast Discussion National Weather Service Louisville KY 619 AM EST SUN JAN 10 2016 ...Updated Aviation Discussion... ...Forecast Update... Updated at 604 AM EST Sun Jan 10 2016 Surface low has rapidly moved into west central Ohio, and frontogenetical band will continue to slowly weaken as it pivots across mainly the NW half our CWA through mid to late morning. Have picked up several reports of 1 to 2 inches along and north of the Ohio River, and expect that many areas just south of the river will end up with at least an inch. Winds are gusting to between 25 and 35 mph at times, which could blow what snow accumulates around. Additionally, temps are crashing with western portions of our CWA already down into the low and mid 20s. As temps fall into the teens west of I-65 over the next several hours, wind chill values will drop as low a -3 to 10 above zero. Have dropped the Winter Weather Advisory down across our far SW where frontogenetical band fell apart before more than a dusting could fall. Have alse dropped the western tier of the advisory where snow has stopped falling. Replaced this area with a Special Weather Statement for slick roads, some blowing snow, and bitter wind chills. .SHORT TERM (Now through Monday)... Issued at 315 AM EST Sun Jan 10 2016 ...Light Accumulating Snow and Gusty Winds Today... Surface low has rapidly lifted NE out of our CWA over the past hour and will make it`s way to the Ontario/Quebec border by this evening. Meanwhile, strong surface cold front has pushed east of a BWG to SDF line and will advance east of our CWA before sunrise. Temps are crashing behind the front, as HNB is already at freezing. Rain/snow change over line now stretches from BWG up through Salem Indiana and will continue to rapidly push east through the pre-dawn hours. Expecting the Louisville metro area to change over to snow between 3 and 4 AM EST, and the Lexington metro between 5 and 6 AM EST. There could be a brief period of sleet with the changeover (recently reported by a spotter near BWG), however this will be of no consequence and very short lived as the low level thermodynamic profile crashes and quickly changes to snow. Overall, see no reason to change to the ongoing forecast as deformation band slides through the region. It should gradually weaken as the surface low moves NE and some frontogenesis is lost. Additionally, dry air will begin to cut off deep moisture. However, with the band pivoting and then lifting over the area along a generally constant axis, residence time will be enough to realize accums. So, will keep going Winter Weather Advisory in place, with a general 1 to 2 inches in most spots. Our far NW is more likely to see 2 to 3 inches, with the far SE part of the advisory more in the half to 1 inch range. Outside of the advisory, a dusting to a half an inch is possible. Impacts should be somewhat mitigated by the warm road/ground temps, which will limit most accums to grassy/elevated surfaces. However snowfall rates and persistence should be enough to allow for some minor road accums at times. Winds will also gust up around 25-35 mph at times so visibilities could be reduced. Big change in the short term is really with temps as HRRR continues to handle the Arctic airmass well. It brings mid and upper teens into our West later this morning, which will yield wind chill values down around zero. Use caution if traveling our expected to be outside. Otherwise, snow showers taper off in the Blue Grass region around midday, with temps staying in the teens in our west and falling through the 20s east. With gusty west winds continuing, wind chills will stay in the single digits to lower teens. Tonight - Monday... Dry and cold conditions then take over for tonight and Monday as the Arctic surface high settles to our south, and benign NW flow aloft rules our upper air pattern. Look for lows tonight in the 10 to 15 degree range. Highs on Monday should recover to the 28-35 range as light SW flow returns on the back side of the surface high. .LONG TERM (Monday Night through Saturday)... Issued at 315 AM EST Sun Jan 10 2016 Monday Night - Tuesday... ...Confidence Growing for Intense Snow Shower Potential Tuesday Morning... A strong PV anomaly and associated surface low will slide across the Great Lakes late Monday night into Tuesday. Another Arctic front will trail from this system, sliding through our CWA Tuesday morning through the early afternoon. Pretty concerned about the potential for intense snow showers with this system along and north of I-64 likely during the morning commute. Low and mid level lapse rates steepen dramatically to the point where some instability will likely be available. This combined with saturation up through the DGZ would be enough to warrant scattered to numerous intense snow showers. The bulk of these would fall from the pre-dawn hours through about midday along and north of I-64. If data holds, these types of scenarios can produce light but very quick accumulations that make travel extremely hazardous, especially at highway/interstate speeds because rapid accumulations occur over short distances. Additionally, gusty winds between 30 and 40 mph appear to be possible which would reduce visibilities even more. Tuesday Night - Thursday Night... Arctic surface high builds in Tuesday night along with dry NW flow aloft. This pattern will dominate sensible weather through mid week resulting in initial cold, but moderating temps. We`ll also be dry. Lows Tuesday night should once again fall into the 10 to 15 degree range in most spots, with wind chills likely in the 0 to 10 range. Highs Wednesday recover into the mid/upper 20s and low 30s. Southerly flow returns and brings slightly milder lows Wednesday night. Look for the 20 to 25 degree range in most spots. Cool valley, especially in the east, will drop to the mid/upper teens. Thursday brings temps back into the low and mid 40s. Lows will be around 30 Thursday Night. Friday - Saturday... Low confidence for this period as models diverge in a complex pattern. Overall this will be a cooler/wetter period with chances for rain and snow. && .AVIATION (12Z TAF Update)... Updated at 619 AM EST Sun Jan 10 2016 Snow will be east of BWG by 12Z and will end at SDF right around the beginning of the TAF period. The band of snow will move through LEX, tapering off around 14Z-1430Z. Behind the snow, low clouds will persist through the rest of the daylight hours just under fuel alternate but above IFR. Those low clouds will clear out as high pressure moves in from the west this evening. West winds will be gusty today, and will quickly settle down with sunset this evening. && .LMK Watches/Warnings/Advisories... KY...Winter Weather Advisory until noon EST /11 AM CST/ today for KYZ024-025-027>035-038-045-053-062-063. IN...Winter Weather Advisory until noon EST today for INZ076>079-084- 090>092. && $$ Update.........BJS Short Term.....BJS Long Term......BJS Aviation.......13
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
510 AM CST SUN JAN 10 2016 .UPDATE... Issued at 510 AM CST SUN JAN 10 2016 Aviation update. && .SHORT TERM...(Today through Tuesday night) Issued at 247 AM CST SUN JAN 10 2016 Just made a few last minute adjustments to added snow flurries (trace precipitation) with the approaching cold air stratocumulus working in behind the upper trough and deformation zone. This trace precipitation may diminish be 16z, but decided to keep a mention in part of the WFO PAH forecast area through 18z (noon). The Winter Weather Advisory looks to be on track for expiration at 10z (4 am CST), with the possible exception of the last row of counties from Spencer County IN, down to Todd County KY. Snowfall production should be diminishing markedly by that time, so will not extend the Advisory beyond its scheduled expiration. Radar trends from the KVWX radar suggest the lift/forcing tied to the deformation zone is beginning to lift northeast and should lessen the overall snow production, especially since the favored dendritic growth zone temperature profile is also shifting northeast per the RAP guidance. Know that there is some snow cover in place, made a few minor temperature adjustments to reflect the impact of the snow cover for Sunday night and into Monday. It may not be enough, but attempted to reflect the impact of the snow cover during insolation (sunshine) and longwave/shortwave radiation at night. The ECMWF and NMM Version of the NAM-WRF, and to a lesser extent the Canadian handle the next shortwave clipper moving out of central Canada late Monday Night into Tuesday across the WFO PAH forecast area. Most of the numerical model suite has been keying in on this feature since late last week. Temperature profiles should keep the precipitation in the form of snow. Given the lower moisture availability and higher snow to liquid ratios, snowfall amounts should hold between one quarter and three quarters of an inch by Tuesday morning over Southwest Indiana, Northwest Kentucky, and small part of Southeast Illinois. Dry conditions and below normal temperatures will dominate the rest of the forecast period. .LONG TERM...(Wednesday through Saturday) Issued at 247 AM CST SUN JAN 10 2016 Will use a deterministic GFS/ECMWF blend 12z Wed through 12z Thur, then a blend of the 00z GEFS and 12z ECENS will be used from 12z Thur through Saturday. Too much forecast spread and run to run consistency issues with energies within the overall mid tropospheric flow to utilize the ops models too much. High pressure will move east with dry weather the rule Wednesday through Thursday. Will carry a slight chance of R-/S- Friday through Saturday as the mean mid trop trof moves east from the nation`s mid section to our area. Changing thermal profile forecast and uncertainty means we will keep wording generic. Temps will be a blend of ensemble MOS and deterministic model output. && .AVIATION... Issued at 510 AM CST SUN JAN 10 2016 MVFR cigs will persist east of a KMVN-KCEY line early this morning with some light snow showers possibly affecting KEVV/KOWB. Clouds and flurries over Missouri should diminish with time. Otherwise overall through the afternoon, decreasing clouds. Gusty WNW winds will gradually lower, and become light tonight with clear skies. && .PAH Watches/Warnings/Advisories... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
247 AM CST SUN JAN 10 2016 .SHORT TERM...(Today through Tuesday night) Issued at 247 AM CST SUN JAN 10 2016 Just made a few last minute adjustments to added snow flurries (trace precipitation) with the approaching cold air stratocumulus working in behind the upper trough and deformation zone. This trace precipitation may diminish be 16z, but decided to keep a mention in part of the WFO PAH forecast area through 18z (noon). The Winter Weather Advisory looks to be on track for expiration at 10z (4 am CST), with the possible exception of the last row of counties from Spencer County IN, down to Todd County KY. Snowfall production should be diminishing markedly by that time, so will not extend the Advisory beyond its scheduled expiration. Radar trends from the KVWX radar suggest the lift/forcing tied to the deformation zone is beginning to lift northeast and should lessen the overall snow production, especially since the favored dendritic growth zone temperature profile is also shifting northeast per the RAP guidance. Know that there is some snow cover in place, made a few minor temperature adjustements to reflect the impact of the snow cover for Sunday night and into Monday. It may not be enough, but attempted to reflect the impact of the snow cover during insolation (sunshine) and longwave/shortwave radiation at night. The ECMWF and NMM Version of the NAM-WRF, and to a lesser extent the Canadian handle the next shortwave clipper moving out of central Canada late Monday Night into Tuesday across the WFO PAH forecast area. Most of the numerical model suite has been keying in on this feature since late last week. Temperature profiles should keep the precipitation in the form of snow. Given the lower moisture availability and higher snow to liquid ratios, snowfall amounts should hold between one quarter and three quarters of an inch by Tuesday morning over Southwest Indiana, Northwest Kentucky, and small part of Southeast Illinois. Dry conditions and below normal temperatures will dominate the rest of the forecast period. .LONG TERM...(Wednesday through Saturday) Issued at 247 AM CST SUN JAN 10 2016 Will use a deterministic GFS/ECMWF blend 12z Wed through 12z Thur, then a blend of the 00z GEFS and 12z ECENS will be used from 12z Thur through Saturday. Too much forecast spread and run to run consistency issues with energies within the overall mid tropospheric flow to utilize the ops models too much. High pressure will move east with dry weather the rule Wednesday through Thursday. Will carry a slight chance of R-/S- Friday through Saturday as the mean mid trop trof moves east from the nation`s mid section to our area. Changing thermal profile forecast and uncertainty means we will keep wording generic. Temps will be a blend of ensemble MOS and deterministic model output. && .AVIATION... Issued at 1144 AM CST SAT JAN 9 2016 Widespread rain with accompanying ifr conditions will continue this afternoon. A cold front was between kpah and kcgi at 17z. This front will progress slowly east across the kpah area this afternoon and the kevv/kowb areas around 00z. Winds will suddenly change direction into the northwest as the front passes. Winds will become quite gusty overnight, especially at kevv/kowb, where gusts around 30 knots are likely. The rain will change to snow for a few hours before precip ends tonight. Once precip ends, cigs and vsbys should quickly improve to vfr. Clearing skies are expected around sunrise at kpah/kcgi, but mvfr cigs should persist at kevv/kowb into midday. && .PAH Watches/Warnings/Advisories... IL...NONE. MO...NONE. IN...Winter Weather Advisory until 4 AM CST early this morning for INZ081-082-085>088. KY...Winter Weather Advisory until 4 AM CST early this morning for KYZ007-010>022. && $$ SHORT TERM...Smith LONG TERM...CN AVIATION...MY
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1118 PM CST SAT JAN 9 2016 .MESOSCALE DISCUSSION... Issued at 1118 PM CST SAT JAN 9 2016 Distance and location from the surface low does make a difference. Surface low track is currently running about 50 miles east-southeast of projected model suite track less than 12-18 hours ago from previous short and medium range guidance. In conversation with evening forecast shift and monitor of social media reports suggests sharpening of deformation zone over Southeast Illinois, west of the Wabash river around 03z-04z. Reports of one to two inches of snow were coincident with this feature. The 3km HRRR and 13km RAP appear to have caught onto this feature and are progressing it nicely through the WFO PAH forecast area. The Dual Pol Correlation Coefficent radar product also did an excellent job of depicting the transition zone from rain to snow this evening. Accumulation rates within 15-20 minutes of the switch to snow were enhanced in sharpened zones of potential vorticity and low/mid level forcing as the system moved into Southwest Indiana. There is the potential that Southwest Indiana may get a secondary burst of snow between 11 pm and 2 pm CST. This may enhance the snowfall rates and provide an additional inch of snow. May adjust snowfall forecast closer to Pike County Indiana to reflect this change. Otherwise, timing of snow across the WFO PAH forecast area appears on track. Will likely drop western edge of advisory overnight, on a sequential basis as rows of counties see the snow depart from their area. && .UPDATE... Issued at 919 PM CST SAT JAN 9 2016 The changeover from rain to snow--with some sleet briefly mixed in the transition--continues to progress from west to east across the forecast area. Dual pol Doppler radar data indicates the rain/snow line has reached near the Wabash River south to east of Paducah and Mayfield Kentucky as of 9 pm. Thus far, nothing higher than an inch of snow accumulation has been reported to the office. The highest reports thus far include about 0.75 inch in Thompsonville, Illinois and about an inch in Fulton, Kentucky. The transition from rain to snow should have occurred across most of the area--including Owensboro and Hopkinsville--by midnight. About 3 to 4 hours of moderate to occasionally heavy snow can be expected along and east of the current snow band, with about 1/2 to 2/3 of that resulting in accumulation. Believe that the current 1 to 3 inches of total snow accumulation handles this event well, but a few isolated higher totals are still possible. Most of the initial accumulation will occur on grassy and elevated surfaces, with potential issues developing on roadways towards the tail end of the event as temperatures commence their plunge through the 20s. Will likely drop about a half dozen counties from the western periphery of the advisory within the next hour or so. Otherwise, forecast table seems to have been set quite well by the day shift. .SHORT TERM...(This evening through Monday) Issued at 329 PM CST SAT JAN 9 2016 Well, tonight winter weather forecast still marred with a bit of uncertainty, though many operational synoptic scale models have come into better agreement on many aspects of the evolving storm system. Surface low now near the MEM area will lift northeast into south central KY this evening...allowing much colder air will spread se into the region. The big question continues to be how intense of a deformation area will form as a mid/upper low moving east into nern AR ejects ne during the night time hours. Am going with the notion that at least moderate band of snow will develop early tonight from the bootheel region of se MO n/ne into much of southern IL. The deformation area should be in a region where thermal profiles suggest all snow. However, still in question is how quickly the sfc temps can get close to freezing with a relatively warm ground beneath. Went with the through that minor accumulations appear likely at this time, mainly on grassy surfaces. However, even wet roadways may have a tendency to freeze over later after the precip ends and even colder air rushes in on blustery nw winds gusting 20-30 mph. Will issue advisory with this package for 1-3" grassy accumulations generally along and east of the MS River. Wind chills will likely be in the single digits for church goers Sunday AM. Bone chilling cold will continue to spill in for the remainder of the weekend. May see temps hold nearly steady from near 20 to the mid/upper 20s south Sunday, despite return to sunshine. .LONG TERM...(Monday night through Saturday) Issued at 329 PM CST SAT JAN 9 2016 The overall 500 mb pattern will consist of a de-amplifying trough over the eastern states and a developing weak trough over the central states. This relatively low amplitude pattern will translate into a gradual moderation in temperatures, along with small precip chances. The long-term period will begin with the passage of an arctic shortwave, which will be rotating around a deep vortex over Ontario province. The associated cold front will bring a reinforcing surge of very cold air. There should be enough moisture to squeeze out scattered snow showers along the front late Monday night into Tuesday morning, primarily north and east of kpah. Will keep slight chance pops in those areas. Temps should hold about steady in the 30s on Tuesday. Tuesday night could end up the coldest night so far this season as surface ridging passes overhead. Forecast lows will be in the teens, but there is a potential for much lower temps if snow cover materializes before then. Wednesday into Thursday, the eastern trough will quickly lift out as a 500 mb shortwave ridge moves into the Mississippi Valley. The ridge will be accompanied by dry weather and a gradual moderation in temps. Highs should reach the lower to mid 40s on Thursday. There is good agreement on the development of a 500 mb trough over the Plains by the end of the week. However, there is very poor model agreement on the location of the associated surface low and cold front. The forecast will call for small chances of precip Friday into Saturday as the system approaches. Most guidance indicates the 0 degree isotherm at 850 mb will be in our vicinity, so the mention of frozen precip will be kept in the forecast. && .SHORT TERM...(This evening through Monday) Issued at 329 PM CST SAT JAN 9 2016 Well, tonight winter weather forecast still marred with a bit of uncertainty, though many operational synoptic scale models have come into better agreement on many aspects of the evolving storm system. Surface low now near the MEM area will lift northeast into south central KY this evening...allowing much colder air will spread se into the region. The big question continues to be how intense of a deformation area will form as a mid/upper low moving east into nern AR ejects ne during the night time hours. Am going with the notion that at least moderate band of snow will develop early tonight from the bootheel region of se MO n/ne into much of southern IL. The deformation area should be in a region where thermal profiles suggest all snow. However, still in question is how quickly the sfc temps can get close to freezing with a relatively warm ground beneath. Went with the through that minor accumulations appear likely at this time, mainly on grassy surfaces. However, even wet roadways may have a tendency to freeze over later after the precip ends and even colder air rushes in on blustery nw winds gusting 20-30 mph. Will issue advisory with this package for 1-3" grassy accumulations generally along and east of the MS River. Wind chills will likely be in the single digits for church goers Sunday AM. Bone chilling cold will continue to spill in for the remainder of the weekend. May see temps hold nearly steady from near 20 to the mid/upper 20s south Sunday, despite return to sunshine. .LONG TERM...(Monday night through Saturday) Issued at 329 PM CST SAT JAN 9 2016 The overall 500 mb pattern will consist of a de-amplifying trough over the eastern states and a developing weak trough over the central states. This relatively low amplitude pattern will translate into a gradual moderation in temperatures, along with small precip chances. The long-term period will begin with the passage of an arctic shortwave, which will be rotating around a deep vortex over Ontario province. The associated cold front will bring a reinforcing surge of very cold air. There should be enough moisture to squeeze out scattered snow showers along the front late Monday night into Tuesday morning, primarily north and east of kpah. Will keep slight chance pops in those areas. Temps should hold about steady in the 30s on Tuesday. Tuesday night could end up the coldest night so far this season as surface ridging passes overhead. Forecast lows will be in the teens, but there is a potential for much lower temps if snow cover materializes before then. Wednesday into Thursday, the eastern trough will quickly lift out as a 500 mb shortwave ridge moves into the Mississippi Valley. The ridge will be accompanied by dry weather and a gradual moderation in temps. Highs should reach the lower to mid 40s on Thursday. There is good agreement on the development of a 500 mb trough over the Plains by the end of the week. However, there is very poor model agreement on the location of the associated surface low and cold front. The forecast will call for small chances of precip Friday into Saturday as the system approaches. Most guidance indicates the 0 degree isotherm at 850 mb will be in our vicinity, so the mention of frozen precip will be kept in the forecast. && .AVIATION... Issued at 1144 AM CST SAT JAN 9 2016 Widespread rain with accompanying ifr conditions will continue this afternoon. A cold front was between kpah and kcgi at 17z. This front will progress slowly east across the kpah area this afternoon and the kevv/kowb areas around 00z. Winds will suddenly change direction into the northwest as the front passes. Winds will become quite gusty overnight, especially at kevv/kowb, where gusts around 30 knots are likely. The rain will change to snow for a few hours before precip ends tonight. Once precip ends, cigs and vsbys should quickly improve to vfr. Clearing skies are expected around sunrise at kpah/kcgi, but mvfr cigs should persist at kevv/kowb into midday. && .PAH Watches/Warnings/Advisories... IL...Winter Weather Advisory until 4 AM CST Sunday for ILZ076>078- 081>083-085>094. MO...Winter Weather Advisory until 4 AM CST Sunday for MOZ111-112-114. IN...Winter Weather Advisory until 4 AM CST Sunday for INZ081-082- 085>088. KY...Winter Weather Advisory until 4 AM CST Sunday for KYZ001>022. && $$ MESOSCALE...Smith UPDATE...RJP SHORT TERM...GM LONG TERM...MY AVIATION...MY
AREA FORECAST DISCUSSION
NWS GAYLORD MI
924 PM EST MON JAN 11 2016 .UPDATE... ISSUED AT 923 PM EST MON JAN 11 2016 POORLY-ORGANIZED CLIPPER TO OUR W WILL SERIOUSLY GET IT/S ACT TOGETHER OVER THE NEXT 12-18 HOURS...AS THE FORCING SHORTWAVE DIGS AND TAKES ON A NEUTRAL AND EVENTUAL NEGATIVE TILT. RADAR RETURNS AND -SN COVERAGE IS INCREASING IN SW SECTIONS OF THE FORECAST AREA. THE SYSTEM IS A TYPICAL MOISTURE- STARVED CLIPPER...AND IT/S SOON-TO- BE- IMPRESSIVE DYNAMICS WON/T QUITE COME TOGETHER FAST ENOUGH TO PRODUCE LARGE AMOUNTS OF SYNOPTIC SNOW. A GENERAL 2-4 INCH SEEMS FINE FOR TONIGHT/TOMORROW MORNING SOUTH OF A LINE FROM ELK RAPIDS TO TAWAS....LESS THAN THAT NORTH. OF COURSE...THE PRIMARY CONCERN FOR THE NIGHT AHEAD IS LAKE ENHANCEMENT...AS SYNOPTIC-SCALE MOISTURE/DYNAMICS OVERRUN AN ALREADY ACTIVE LAKE MI. PRIMARY SSW BAND SEEMS TO BE TAKING SHAPE...TOUCHING THE COAST NEAR LDM...TO 5-10SM W OF FRANKFORT... TO BEAVER ISL...TO JUST W OF THE BRIDGE. SOLID AGREEMENT FROM THE LATEST NAM AND HRRR THAT THIS BAND WILL STAY OFF THE NW LOWER MI UNTIL AFTER 09Z...WHEN DEVELOPING POST-CLIPPER NW FLOW WILL SHOVE IT ONSHORE. STILL EXPECT SOME DECENT CONVECTIVE ELEMENTS RIGHT ON THE NW LOWER COAST...AND WILL HOLD ONTO HIGHER SNOWFALL TOTALS AT MBL/FRANKFORT/GLEN HAVEN. BUT WILL TEND TO DECREASE ACROSS THE REST OF MANISTEE/BENZIE/LEELANAU. WILL SHARPLY REDUCE SNOW AMOUNTS FOR EMMET CO...AS THE NORTH END OF THE BAND SEEMS INCLINED TO STAY NW OF THERE. IN A SIMILAR VEIN...WILL PUSH THE SNOWFALL MAX IN MACKINAC CO WEST TO BETWEEN ST IGNACE AND NAUBINWAY. FOR MOST OF THE AREA (CERTAINLY FOR NW LOWER MI)...THE REAL SHOW WILL BE TOMORROW. WILL LEAVE HEADLINES ALONE...THOUGH TRY TO ADD TEMPORAL/SPATIAL DETAILS IN THE WSW. && .NEAR TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 407 PM EST MON JAN 11 2016 HIGH IMPACT WEATHER...HEAVY LAKE ENHANCED SNOW FOR SOME AREAS. ..MORE LAKE EFFECT SNOW... ON THE CURRENT SURFACE WEATHER MAP...1010 MB LOW PRESSURE WAS OVER NORTHWEST MINNESOTA WITH 1028 MB HIGH PRESSURE OVER SOUTHERN OHIO. APX RADAR SHOWS WESTERLY FLOW LAKE EFFECT SNOW BANDS HAVE SHIFTED MORE TO THE NORTH WITH A FOCUS NOW OVER THE TIP OF THE MITT. THE MAIN NEAR TERM FORECAST CONCERNS WILL FOCUS ON HEADLINE MANAGEMENT JUST LIKE OVER THE LAST FEW DAYS. WELL ADVERTISED ALBERTA CLIPPER WILL RIDE SOUTHEAST PASSING ACROSS CENTRAL LOWER MICHIGAN LATE TONIGHT INTO TUESDAY MORNING. THIS WILL REALLY RAMP UP/ENHANCE ONGOING LAKE EFFECT ACTIVITY. THE QUESTION REMAINS WHERE THE MOST INTENSE BAND(S) WILL SET UP. MODEL SOUNDINGS SHOW INVERSION HEIGHTS THROUGH THE ROOF WITH COPIOUS AMOUNTS OF MOISTURE THROUGH THE COLUMN TARGETING THE SWEET SPOT (DGZ CENTERED AROUND -15 C). WINDS CONTINUE TO BACK THROUGH THIS EVENING FROM THE WEST ALL THE WAY BACK TO THE SOUTH OR JUST WEST OF SOUTH OVERNIGHT. MESOSCALE MODELS VARY ON WHERE THE EXTREMELY IMPRESSIVE LOOKING LAKE MICHIGAN BAND WILL SET UP...EITHER ALONG OR JUST OFF THE LEELANAU TO MANISTEE SHORELINE EXTENDING INTO MACKINAC COUNTY AS WELL. AFTER COORDINATION WITH SURROUNDING OFFICES WILL GO WITH A WINTER STORM WARNING FOR MANISTEE...BENZIE AND LEELANAU COUNTIES. WILL ALSO HAVE WARNINGS FOR WEXFORD AND GRAND TRAVERSE COUNTIES...ALTHOUGH THE BAND MAY REMAIN WEST OF THERE FOR MUCH IF NOT ALL OF THE NIGHT AND WAIT UNTIL TUESDAY TO BRING THAT AREA HEAVY SNOW. WILL ALSO HOIST A WINTER WEATHER ADVISORY FOR MACKINAC COUNTY AS CENTRAL AND EASTERN PORTIONS OF THE COUNTY MAY GET IN ON THE ACTION. NORTHERN EMMET COUNTY WILL HAVE TO BE WATCHED TO SEE IF THE BAND CAN CURL INTO NORTHERN PORTIONS OF THE COUNTY AS MESOSCALE MODELS SUGGEST. ACCUMULATIONS WILL VARY WIDELY TONIGHT WITH AROUND AN INCH OR LESS EAST OF WHERE THE HEADLINES ARE TO UPWARDS OF 6 INCHES OR MORE FROM MANISTEE TO LELAND. TEMPERATURES WILL RANGE FROM THE CHILLY MIDDLE SINGLE DIGITS ABOVE ZERO TO THE LOWER AND MIDDLE TEENS. WINDS WILL BE FAIRLY LIGHT TONIGHT SO NO BLOWING OR DRIFTING PROBLEMS LUCKILY. && .SHORT TERM...(TUESDAY THROUGH THURSDAY) ISSUED AT 407 PM EST MON JAN 11 2016 HIGH IMPACT WEATHER POTENTIAL: ACCUMULATING LAKE EFFECT SNOWS...ESPECIALLY TUESDAY. PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: NO SURPRISES...WITH STRONG CLIPPER SYSTEM DIVING THROUGH DEEP OVERHEAD TROUGHING EXPECTED TO ONCE AGAIN RAMP UP THE LAKE SNOW MACHINE TUESDAY. PATTERN BREAKS DOWN JUST A TOUCH THEREAFTER AS HEIGHTS BEGIN TO REBOUND SOME AND OVERALL FLOW PATTERN ACROSS THE CONUS TAKES ON A TOUCH MORE ZONAL FLAVOR. PRIMARY FORECAST CONCERNS/CHALLENGES: ADDRESSING LAKE INDUCED SNOW EVOLUTION AND SNOW AMOUNTS...ESPECIALLY TUESDAY. DETAILS: ONE RATHER IMPRESSIVE LAKE EFFECT SNOW EVENT EXPECTED TO BE ONGOING FIRST THING TUESDAY AS CLIPPER SPINS OFF TO THE EAST AND COLD AND MOIST NORTHWEST FLOW DEVELOPS. BANDS SHOULD BE REALLY TARGETING THE GRAND TRAVERSE BAY AREA NEAR OR SHORTLY AFTER SUNUP...SLOWLY PIVOTING FURTHER INLAND AS WIND FIELDS BEGIN TO BACK. H8 TEMPERATURES HAVE STEADILY "WARMED" IN GUIDANCE PROGS THE LAST FEW CYCLES...NOW EXPECTED TO BE IN PRIME DENDRITE PRODUCING -16C TO -18C RANGE. COMBINE THIS WITH LAKE SUPERIOR PRECONDITIONING AND NEARLY UNABATED INVERSION HEIGHTS...AND THE STAGE IS SET FOR SEVERAL INCHES OF ACCUMULATION AND SNOWFALL RATES EXCEEDING AN INCH PER HOUR AT TIMES. ONCE AGAIN...THE MOST SIGNIFICANT SNOWS WILL BE CENTERED ON THE GRAND TRAVERSE BAY REGION. AS MENTIONED...SLOWLY BACKING FLOW DOES BRING BETTER BANDS FURTHER INLAND INTO THE SNOWBELTS OF EASTERN UPPER AND NORTHWEST LOWER THROUGH THE AFTERNOON...ALTHOUGH OF LESS INTENSITY WITH FALLING INVERSION HEIGHTS AND LOSS OF ANY SYNOPTIC CONTRIBUTION. LAKE SNOWS CONTINUE INTO TUESDAY NIGHT AND WEDNESDAY AS WINDS CONTINUE TO STEADILY BACK AROUND TO SOUTHWEST BY WEDNESDAY. SHIFTING WINDS AND MORE MARGINAL LAKE PARAMETERS WILL CURTAIL INTENSITY SOME...BUT NO DOUBT AT LEAST A FEW INCHES OF ACCUMULATION WILL BE FANNED OUT ACROSS THE SNOW BELT REGIONS. UNCERTAINTY INCREASES FOR WEDNESDAY NIGHT AND THURSDAY WITH HINTS THAT A WEAK WAVE AND PLUME OF DEEPER MOISTURE WILL STRETCH OUT ACROSS OUR AREA. THERMAL PROGS DO WARM...HELPING TONE DOWN LAKE PROCESSES SOME. DON`T THINK THEY WILL END...AND HAVE SOME CONCERN DEEPENING MOISTURE FIELD/TIGHTENING THERMAL GRADIENT WILL BRING A MORE GENERAL WIDESPREAD LIGHT SNOW. CURRENT CHANCY POPS WILL SUFFICE FOR NOW...LETTING TRENDS WORK THEMSELVES OUT BEFORE BECOMING MORE SPECIFIC. && .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 407 PM EST MON JAN 11 2016 AT THE START OF THE PERIOD A BROAD AREA OF LOW PRESSURE IS CENTERED OVER THE PLAINS...GRADUALLY MOVING NORTHEASTWARD TOWARD THE UPPER MS VALLEY/GREAT LAKES. FAIRLY DECENT GLOBAL MODEL GUIDANCE AGREEMENT THAT AN AREA OF SNOW WILL BE ONGOING ALONG A RATHER TIGHT BAROCLINIC ZONE ACROSS AT LEAST PART OF NORTHERN MICHIGAN THURSDAY NIGHT INTO FRIDAY MORNING. THE MAIN FOCUS THROUGHOUT THE EXTENDED REVOLVES AROUND THE AFOREMENTIONED AREA OF LOW PRESSURE AND ITS EVENTUAL TRACK TOWARD THE HEART OF THE CONUS FRIDAY AFTERNOON INTO SATURDAY. THE ENVELOPE OF SOLUTIONS CONTINUES TO REMAIN FAIRLY LARGE AT THIS TIMEFRAME...HOWEVER WILL BE WORTH KEEPING AN EYE ON FOR THE POTENTIAL OF ANOTHER WIDESPREAD SYNOPTIC PRECIP EVENT ACROSS NRN MICHIGAN. DETAILS SHOULD BE ABLE TO BE REFINED AS THE ACTUAL WAVE MAKES ITS WAY ONTO THE WEST COAST AND IS SAMPLED BY THE UPPER AIR NETWORK ON WEDNESDAY. BEYOND NEXT SATURDAY...IT LOOKS TO REMAIN RATHER CHILLY ACROSS THE GREAT LAKES WITH ADDITIONAL LAKE EFFECT SNOW SHOWERS POSSIBLE THROUGH THE END OF THE PERIOD. TEMPERATURES NEAR NORMAL TO START THE EXTENDED WITH UPPER 20S TO NEAR 30 DEGREE HIGHS EXPECTED FRIDAY AND SATURDAY BEFORE A CONSENSUS BLEND SUGGESTS THAT TEENS RETURN TO END THE WEEKEND AND FOR THE START OF NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 643 PM EST MON JAN 11 2016 IFR AT TIMES TONIGHT MBL/PLN...VERY LATE TONIGHT INTO TUE MORNING TVC. LAKE EFFECT SHSN WILL INCREASE IN INTENSITY TONIGHT ALONG THE LAKE MI COAST...AS AN ALBERTA CLIPPER TRACKS ACROSS LOWER MI. ACTIVITY WILL IMPACT MBL/PLN FOR THE BULK OF THE NIGHT...BEFORE SHIFTING INLAND TOWARD TVC VERY LATE. AT A MINIMUM...INTENSE SNOWS WILL EVENTUALLY GET SHOVED INTO THE NW LOWER AIRPORTS FOR A PERIOD OF MODERATE TO HEAVY SNOWFALL WITH 1 TO 2 INCHES OF SNOW PER HOUR POSSIBLE AND 20:1 LIQUID TO SNOWFALL RATIOS. WINDS WILL BE LIGHT FROM THE SOUTH BEFORE SHIFTING INTO THE NORTHWEST AND BECOMING GUSTY LATE TUESDAY MORNING. && .MARINE... ISSUED AT 407 PM EST MON JAN 11 2016 STILL A FEW ADVISORY LEVEL WIND GUSTS SCATTERED AROUND THE NEARSHORE ZONES. WINDS INCREASE AGAIN TO ADVISORY LEVELS LATE TONIGHT THROUGH MUCH OF TUESDAY NIGHT AS A STORM SYSTEM CROSSES THE REGION. THIS STORM SYSTEM WILL BRING LIGHT SYSTEM SNOW...BUT PERIODS OF MODERATE TO HEAVY LAKE ENHANCED SNOWS CAN BE EXPECTED IN THE GRAND TRAVERSE BAY REGION. FOR SIMPLICITY SAKE HAVE SMALL CRAFT ADVISORIES FOR ALL ZONES THROUGH THE FORECAST PERIOD...THROUGH WINDS WILL LIKELY BE UNDER CRITERIA FOR A PORTION OF TONIGHT. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ015. WINTER STORM WARNING UNTIL 7 PM EST TUESDAY FOR MIZ020-025-026- 031-032. LH...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LHZ345>349. LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LMZ323-341-342- 344>346. LS...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LSZ321-322. && $$ UPDATE...JZ NEAR TERM...SULLIVAN SHORT TERM...MSB LONG TERM...GILLEN AVIATION...JZ MARINE...SULLIVAN
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
919 PM EST MON JAN 11 2016 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 305 PM EST MON JAN 11 2016 A WAVE OF LOW PRESSURE WILL DEEPEN AS IT TRACKS EASTWARD THROUGH LOWER MICHIGAN TONIGHT. SNOW WILL INCREASE ACROSS THE REGION AS A RESULT AND COULD BE HEAVY. THE SNOW WILL PERSIST THROUGH TUESDAY WITH LOCALLY HEAVY SNOW ESPECIALLY CLOSE TO LAKE MICHIGAN. HAZARDOUS TRAVEL IS EXPECTED FOR MOST AREA THROUGH TUESDAY. ARCTIC AIR WILL CONTINUE TO FLOW INTO THE REGION ON WEDNESDAY WITH ADDITIONAL LAKE EFFECT SNOW POSSIBLE. && .UPDATE... ISSUED AT 915 PM EST MON JAN 11 2016 FIRST SHORT WAVE IS JUST MOVING THROUGH AND LAKE EFFECT HAS FLARED UP IN RESPONSE. RADAR SHOWS LIGHT TO MODERATE SHSN OVER THE WEST CENTRAL CWA. THE HEAVIEST SNOW WILL REORIENT OVERNIGHT AS WINDS BECOME WEST AND THEN NORTHWEST. THE NEXT SHORT WAVE IS WELL SEEN IN WV IMAGERY OVER WISCONSIN AND WILL PROVIDE ANOTHER FLARE UP LATER TONIGHT AND EARLY TUESDAY. THIS IS WHEN THE CORE OF THE ARCTIC AIR WILL FLOW IN AND WHEN THE WINDS WILL INCREASE. THIS IS HANDLED IN THE CURRENT FORECAST AND NO CHANGES WERE MADE TO THE HEADLINES. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 305 PM EST MON JAN 11 2016 COMMONLY WITH A DIGGING SYNOPTIC WAVE FOLLOWED BY AN ARCTIC AIRMASS WE TEND TO SEE WIDESPREAD IMPACTS...SOMETIMES SIGNIFICANT IMPACTS. THUS I WENT WITH A WARNING FOR MUCH OF THE LAKESHORE REGION AND A FEW INLAND COUNTIES AS WELL. THE LOW LEVEL FLOW BACKS THIS EVENING AS THE WAVE APPROACHES. THIS WILL ACT TO FOCUS THE MAIN BAND WEST OF KENT COUNTY DUE TO THE FLOW BECOMING SOUTHEAST OVER GRAND RAPIDS THIS EVENING. AS A RESULT IT APPEARS KENT COUNTY WILL MISS MUCH OF THIS INITIAL BANDING THIS EVENING...SO I DID NOT INCLUDE KENT IN THE WARNING. SOME NEWER MODELS ACTUALLY TAKE THE BANDING WEST OF MUSKEGON. THIS WOULD BE UNUSUAL. THE FLOW VEERS NORTHWEST BY 12Z TUE. THE TUESDAY MORNING COMMUTE LOOKS QUITE IMPACTED AS THE BANDS SHIFT AND HEAVY SNOW SHOWERS PERSIST. ALSO THE WINDS WILL INCREASE LATE TONIGHT ALONG THE LAKESHORE AND ALL LOCATIONS ON TUESDAY. BLOWING SNOW WILL INCREASE. I NOTICED THE LATEST HRRR RUC HAD GREATER THAN 35 KNOTS ON THE LAKESHORE. THIS COMBINED WITH HEAVY SNOW BANDS SHOULD SUPPORT NEAR WHITEOUT CONDITIONS. I EXTENDED THE HEADLINES INLAND. THE STRONGER WINDS WILL ACT TO CARRY THE SNOW SHOWERS WELL INLAND. THAT COMBINED WITH WIND GUSTS OVER 20 KNOTS WILL SUPPORT HAZARDOUS TRAVEL AT TIMES ON TUESDAY. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 305 PM EST MON JAN 11 2016 MAIN CONCERN CONTINUES TO BE WINTER WEATHER FRIDAY NIGHT. MOST MODEL GUIDANCE INDICATES LIMITED SNOWFALL WITH THIS EVENT DUE TO STRONG LOW LEVEL WARM ADVECTION AHEAD OF THE SURFACE LOW. AS NOTED IN THE PREVIOUS DISCUSSION...THE GFS HAS BEEN INCONSISTENT RUN TO RUN. HOWEVER THE GFS PARALLEL...GEM...AND FIM ALL FAVOR A WARMER SOLUTION MORE CONSISTENTLY. AS NOTED ALREADY...THE DETERMINISTIC ECMWF SHOWS GOOD RUN TO RUN CONSISTENCY WITH A LOW TRACK INTO THE OHIO VALLEY FAVORABLE FOR SNOW OVER THE FORECAST AREA. HOWEVER...THIS CONTROL RUN IS AN OUTLIER RELATIVE TO MOST ENSEMBLE MEMBERS THAT SHOW LOW TRACKS EITHER OVER LOWER MICHIGAN OR MUCH FARTHER SOUTHEAST. ALL THAT SAID...THERE ARE GOOD REASONS PUT FORTH IN THE PREVIOUS DISCUSSION TO NOT DISCOUNT THE DETERMINISTIC ECMWF ENTIRELY AND TO CONTINUE WATCHING THIS. WHAT IS MORE CERTAIN IS SIGNIFICANT PRECIPITATION FALLING ON A DECENT SNOWPACK BY THE END OF THE WEEK...RAISING CONCERNS FOR RIVERS THAT ARE DISCUSSED IN DETAIL IN THE HYDROLOGY SECTION. A FINAL CONCERN IS THE POTENTIAL FOR LIGHT FREEZING RAIN FRIDAY MORNING AS DEEP MOISTURE OVERSPREADS SURFACE AIR TEMPERATURES IN THE MID TO UPPER 20S. THIS COULD AFFECT THE FRIDAY MORNING COMMUTE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 758 PM EST MON JAN 11 2016 AVIATION CONDITIONS WILL DETERIORATE THROUGH THE COURSE OF THE REMAINDER OF THE EVENING AND OVERNIGHT. VFR AND MVFR CONDITIONS WILL TREND INTO THE IFR CATEGORY AS CEILINGS AND ESPECIALLY VISIBILITIES LOWER TONIGHT. THE WORST OF THE CONDITIONS WILL BE AT KMKG CLOSE TO LAKE MICHIGAN WHERE LIFR IS EXPECTED AS WELL. AS WE HEAD INTO TUESDAY...THE SNOW WILL CONTINUE TO AFFECT MOST TAF SITES WITH BLOWING SNOW BECOMING POSSIBLE AS WELL. WINDS WILL BE STRONG OUT OF THE WEST-NORTHWEST ON TUESDAY GUSTING INTO THE 20-30 KNOT RANGE. CONDITIONS WILL VARY ON TUESDAY BETWEEN MVFR AND IFR. && .MARINE... ISSUED AT 405 PM EST MON JAN 11 2016 EXTENDED THE SCA INTO WEDNESDAY GIVEN INCREASING WINDS FROM THE NORTHWEST OVERNIGHT AND ASSOCIATED WAVE GROWTH. WE COULD EASILY COULD SEE SOME GUSTS OVER 35 OR 40 KNOTS AND WERE CONSIDERING A GALE WARNING WITH THIS FORECAST. THIS WILL BE SOMETHING TO WATCH FOR THE NEXT UPDATE. REGARDLESS...IT WILL GET QUITE UNPLEASANT ON LAKE MICHIGAN OVERNIGHT WITH SNOW AND FREEZING SPRAY. && .HYDROLOGY... ISSUED AT 1121 AM EST MON JAN 11 2016 MINOR RIVER FLOODING IS ONGOING AT HOLT...MAPLE RAPIDS AND IONIA. THE MAPLE RIVER AT MAPLE RAPIDS WILL CONTINUE TO GRADUALLY CLIMB OVER THE NEXT COUPLE OF DAYS BEFORE STABILIZING. HOLT AND IONIA HAVE BEGUN TO SHOW DECLINE. IMPROVEMENT SHOULD CONTINUE. MANY OTHER SITES THROUGH SOUTHWEST LOWER MICHIGAN ARE FLOWING WELL BELOW ACTION STAGE WHILE THE RISES AND HIGHER LEVELS ARE CONCENTRATED SOUTH AND EAST OF GRAND RAPIDS. THESE ARE THE SAME AREAS THAT WERE MORE SO AFFECTED BY MILD WEATHER AND RAINFALL EARLY IN THE WEEKEND. GOING FORWARD...OVERALL STABILIZATION OR IMPROVEMENT IS ANTICIPATED IN THE GRAND SCHEME OF THINGS. CONCERNS ARE MINOR...WHICH INCLUDE THE ACTIVE WEATHER PATTERN AND ARCTIC AIR MASS. PRECIPITATION CHANCES EXIST AT SOME POINT EACH DAY OF THE WEEK. THE GOOD NEWS IS THAT IT WILL ALL LIKELY BE IN THE FORM OF SNOW. THE DOWN SIDE WITH THESE TEMPERATURES IS THE RISING CONCERN FOR ICE FORMATION...ESPECIALLY IN CENTRAL LOWER MICHIGAN WHERE TEMPERATURES HAVE BEEN COLDER FOR A LONGER PERIOD OF TIME. THIS MAY BE THE WEEK WHERE WE SEE SOME ISSUES DEVELOP WITH MINOR ICE JAMMING...ESPECIALLY ON LOWER VOLUME RIVERS THAT FREEZE UP IN A QUICKER FASHION. IT IS NOTHING OF ALARM AT THIS POINT...BUT JUST SOMETHING TO KEEP AN EYE ON WITH OVERNIGHT TEMPS IN THE SINGLE DIGITS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING UNTIL 7 PM EST TUESDAY FOR MIZ037-038-043- 044-050-056-064-071-072. WINTER WEATHER ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ057-058- 065-066-073. WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR MIZ039- 040-045-046-051-052-059-067-074. LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR LMZ844>849. && $$ UPDATE...04 SYNOPSIS...MJS SHORT TERM...MJS LONG TERM...TJT AVIATION...DUKE HYDROLOGY...JAM MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
759 PM EST MON JAN 11 2016 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 305 PM EST MON JAN 11 2016 A WAVE OF LOW PRESSURE WILL DEEPEN AS IT TRACKS EASTWARD THROUGH LOWER MICHIGAN TONIGHT. SNOW WILL INCREASE ACROSS THE REGION AS A RESULT AND COULD BE HEAVY. THE SNOW WILL PERSIST THROUGH TUESDAY WITH LOCALLY HEAVY SNOW ESPECIALLY CLOSE TO LAKE MICHIGAN. HAZARDOUS TRAVEL IS EXPECTED FOR MOST AREA THROUGH TUESDAY. ARCTIC AIR WILL CONTINUE TO FLOW INTO THE REGION ON WEDNESDAY WITH ADDITIONAL LAKE EFFECT SNOW POSSIBLE. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 305 PM EST MON JAN 11 2016 COMMONLY WITH A DIGGING SYNOPTIC WAVE FOLLOWED BY AN ARCTIC AIRMASS WE TEND TO SEE WIDESPREAD IMPACTS...SOMETIMES SIGNIFICANT IMPACTS. THUS I WENT WITH A WARNING FOR MUCH OF THE LAKESHORE REGION AND A FEW INLAND COUNTIES AS WELL. THE LOW LEVEL FLOW BACKS THIS EVENING AS THE WAVE APPROACHES. THIS WILL ACT TO FOCUS THE MAIN BAND WEST OF KENT COUNTY DUE TO THE FLOW BECOMING SOUTHEAST OVER GRAND RAPIDS THIS EVENING. AS A RESULT IT APPEARS KENT COUNTY WILL MISS MUCH OF THIS INITIAL BANDING THIS EVENING...SO I DID NOT INCLUDE KENT IN THE WARNING. SOME NEWER MODELS ACTUALLY TAKE THE BANDING WEST OF MUSKEGON. THIS WOULD BE UNUSUAL. THE FLOW VEERS NORTHWEST BY 12Z TUE. THE TUESDAY MORNING COMMUTE LOOKS QUITE IMPACTED AS THE BANDS SHIFT AND HEAVY SNOW SHOWERS PERSIST. ALSO THE WINDS WILL INCREASE LATE TONIGHT ALONG THE LAKESHORE AND ALL LOCATIONS ON TUESDAY. BLOWING SNOW WILL INCREASE. I NOTICED THE LATEST HRRR RUC HAD GREATER THAN 35 KNOTS ON THE LAKESHORE. THIS COMBINED WITH HEAVY SNOW BANDS SHOULD SUPPORT NEAR WHITEOUT CONDITIONS. I EXTENDED THE HEADLINES INLAND. THE STRONGER WINDS WILL ACT TO CARRY THE SNOW SHOWERS WELL INLAND. THAT COMBINED WITH WIND GUSTS OVER 20 KNOTS WILL SUPPORT HAZARDOUS TRAVEL AT TIMES ON TUESDAY. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 305 PM EST MON JAN 11 2016 MAIN CONCERN CONTINUES TO BE WINTER WEATHER FRIDAY NIGHT. MOST MODEL GUIDANCE INDICATES LIMITED SNOWFALL WITH THIS EVENT DUE TO STRONG LOW LEVEL WARM ADVECTION AHEAD OF THE SURFACE LOW. AS NOTED IN THE PREVIOUS DISCUSSION...THE GFS HAS BEEN INCONSISTENT RUN TO RUN. HOWEVER THE GFS PARALLEL...GEM...AND FIM ALL FAVOR A WARMER SOLUTION MORE CONSISTENTLY. AS NOTED ALREADY...THE DETERMINISTIC ECMWF SHOWS GOOD RUN TO RUN CONSISTENCY WITH A LOW TRACK INTO THE OHIO VALLEY FAVORABLE FOR SNOW OVER THE FORECAST AREA. HOWEVER...THIS CONTROL RUN IS AN OUTLIER RELATIVE TO MOST ENSEMBLE MEMBERS THAT SHOW LOW TRACKS EITHER OVER LOWER MICHIGAN OR MUCH FARTHER SOUTHEAST. ALL THAT SAID...THERE ARE GOOD REASONS PUT FORTH IN THE PREVIOUS DISCUSSION TO NOT DISCOUNT THE DETERMINISTIC ECMWF ENTIRELY AND TO CONTINUE WATCHING THIS. WHAT IS MORE CERTAIN IS SIGNIFICANT PRECIPITATION FALLING ON A DECENT SNOWPACK BY THE END OF THE WEEK...RAISING CONCERNS FOR RIVERS THAT ARE DISCUSSED IN DETAIL IN THE HYDROLOGY SECTION. A FINAL CONCERN IS THE POTENTIAL FOR LIGHT FREEZING RAIN FRIDAY MORNING AS DEEP MOISTURE OVERSPREADS SURFACE AIR TEMPERATURES IN THE MID TO UPPER 20S. THIS COULD AFFECT THE FRIDAY MORNING COMMUTE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 758 PM EST MON JAN 11 2016 AVIATION CONDITIONS WILL DETERIORATE THROUGH THE COURSE OF THE REMAINDER OF THE EVENING AND OVERNIGHT. VFR AND MVFR CONDITIONS WILL TREND INTO THE IFR CATEGORY AS CEILINGS AND ESPECIALLY VISIBILITIES LOWER TONIGHT. THE WORST OF THE CONDITIONS WILL BE AT KMKG CLOSE TO LAKE MICHIGAN WHERE LIFR IS EXPECTED AS WELL. AS WE HEAD INTO TUESDAY...THE SNOW WILL CONTINUE TO AFFECT MOST TAF SITES WITH BLOWING SNOW BECOMING POSSIBLE AS WELL. WINDS WILL BE STRONG OUT OF THE WEST-NORTHWEST ON TUESDAY GUSTING INTO THE 20-30 KNOT RANGE. CONDITIONS WILL VARY ON TUESDAY BETWEEN MVFR AND IFR. && .MARINE... ISSUED AT 405 PM EST MON JAN 11 2016 EXTENDED THE SCA INTO WEDNESDAY GIVEN INCREASING WINDS FROM THE NORTHWEST OVERNIGHT AND ASSOCIATED WAVE GROWTH. WE COULD EASILY COULD SEE SOME GUSTS OVER 35 OR 40 KNOTS AND WERE CONSIDERING A GALE WARNING WITH THIS FORECAST. THIS WILL BE SOMETHING TO WATCH FOR THE NEXT UPDATE. REGARDLESS...IT WILL GET QUITE UNPLEASANT ON LAKE MICHIGAN OVERNIGHT WITH SNOW AND FREEZING SPRAY. && .HYDROLOGY... ISSUED AT 1121 AM EST MON JAN 11 2016 MINOR RIVER FLOODING IS ONGOING AT HOLT...MAPLE RAPIDS AND IONIA. THE MAPLE RIVER AT MAPLE RAPIDS WILL CONTINUE TO GRADUALLY CLIMB OVER THE NEXT COUPLE OF DAYS BEFORE STABILIZING. HOLT AND IONIA HAVE BEGUN TO SHOW DECLINE. IMPROVEMENT SHOULD CONTINUE. MANY OTHER SITES THROUGH SOUTHWEST LOWER MICHIGAN ARE FLOWING WELL BELOW ACTION STAGE WHILE THE RISES AND HIGHER LEVELS ARE CONCENTRATED SOUTH AND EAST OF GRAND RAPIDS. THESE ARE THE SAME AREAS THAT WERE MORE SO AFFECTED BY MILD WEATHER AND RAINFALL EARLY IN THE WEEKEND. GOING FORWARD...OVERALL STABILIZATION OR IMPROVEMENT IS ANTICIPATED IN THE GRAND SCHEME OF THINGS. CONCERNS ARE MINOR...WHICH INCLUDE THE ACTIVE WEATHER PATTERN AND ARCTIC AIR MASS. PRECIPITATION CHANCES EXIST AT SOME POINT EACH DAY OF THE WEEK. THE GOOD NEWS IS THAT IT WILL ALL LIKELY BE IN THE FORM OF SNOW. THE DOWN SIDE WITH THESE TEMPERATURES IS THE RISING CONCERN FOR ICE FORMATION...ESPECIALLY IN CENTRAL LOWER MICHIGAN WHERE TEMPERATURES HAVE BEEN COLDER FOR A LONGER PERIOD OF TIME. THIS MAY BE THE WEEK WHERE WE SEE SOME ISSUES DEVELOP WITH MINOR ICE JAMMING...ESPECIALLY ON LOWER VOLUME RIVERS THAT FREEZE UP IN A QUICKER FASHION. IT IS NOTHING OF ALARM AT THIS POINT...BUT JUST SOMETHING TO KEEP AN EYE ON WITH OVERNIGHT TEMPS IN THE SINGLE DIGITS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING UNTIL 7 PM EST TUESDAY FOR MIZ037-038-043- 044-050-056-064-071-072. WINTER WEATHER ADVISORY UNTIL 7 PM EST TUESDAY FOR MIZ057-058- 065-066-073. WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR MIZ039- 040-045-046-051-052-059-067-074. LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR LMZ844>849. && $$ SYNOPSIS...MJS SHORT TERM...MJS LONG TERM...TJT AVIATION...DUKE HYDROLOGY...JAM MARINE...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
707 PM EST MON JAN 11 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 439 PM EST MON JAN 11 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP MID/UPPER TROF EXTENDING FROM HUDSON BAY S THRU THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES REGION DOWNSTREAM OF A RIDGE EXTENDING ALONG THE W COAST OF CANADA THRU NE ALASKA. A RATHER VIGOROUS LOOKING SHORTWAVE IS DROPPING SE THRU ERN ND/NW MN. ANOTHER WEAKER SHORTWAVE TROF IS SWINGING S THRU NRN MANITOBA. THESE 2 FEATURES...ESPECIALLY THE FIRST SHORTWAVE...WILL DRIVE THE FCST IN THE SHORT TERM. WITH LATEST RAP ANALYSIS SHOWING 850MB TEMPS AROUND -20C ACROSS LAKE SUPERIOR... LES CONTINUES. HOWEVER...BACKING WINDS IN RESPONSE TO THE APPROACHING SHORTWAVE HAS RESULTED IN LES BANDS SHIFTING OFFSHORE OF MORE OF UPPER MI DURING THE DAY. ALTHOUGH CLOUD TOPS WERE UP TO AROUND 10KFT PER KMQT RADAR EARLIER TODAY...THE SHIFTING WINDS... LACK OF WELL ORGANIZED BANDS...AND A MORE SUPPRESSED DGZ TO THE LOWER PART OF THE CONVECTIVE LAYER HAVE KEPT SNOW ACCUMULATIONS IN CHECK. WITH LES ALREADY ONGOING ACROSS LAKE SUPERIOR...APPROACHING SHORTWAVE WILL RESULT IN THE NORMAL INTENSIFICATION OF LES TONIGHT/TUE MORNING. WINDS WILL CONTINUE TO BACK OVER THE NEXT FEW HRS IN RESPONSE TO THE STRONGER SHORTWAVE DROPPING SE THRU MN. THEN AS SFC TROF ASSOCIATED WITH SHORTWAVE MOVES S OVER LAKE SUPERIOR...A SHARPER CONVERGENCE ZONE WILL DEVELEOP THIS EVENING... RUNNING FROM NEAR THE APOSTLE ISLANDS TO N OF COPPER HARBOR THEN OVER TO MICHIPICOTEN ISLAND. CONVERGENCE ZONE SHOULD ALSO HELP LIFT DGZ A BIT HIGHER INTO THE CONVECTIVE LAYER TO INCREASE SNOW-TO-WATER RATIOS. ALTHOUGH THE TRACK OF THE SHORTWAVE IS A BIT FARTHER S THAN IDEAL (PEAK DEEP LAYER FORCING PASSES S OF LAKE SUPERIOR)...SYNOPTIC FORCING/DEEP MOISTURE WILL BE MORE THAN SUFFICIENT TO AID DEVELOPMENT OF HVY SNOW ALONG THE CONVERGENCE ZONE THAT WILL DROP S TONIGHT/EARLY TUE MORNING. WITH WINDS AT LEAST BRIEFLY SHIFTING NNW/N WITH PASSAGE OF SFC TROF...ALL LOCATIONS ALONG LAKE SUPERIOR WILL SEE AT LEAST A BRIEF BURST OF MDT/HVY SNOW. AREA FROM KIWD TO AROUND THE PORCUPINE MOUNTAINS AND FROM VCNTY OF MARQUETTE OVER THE GRAND MARAIS SHOULD SEE THE HEAVIEST SNOW WITH THE TROF PASSAGE. KEWEENAW COUNTY MAY ALSO END UP WITH SOME OF THE HEAVIEST SNOW DUE TO LONG FETCH HVY SNOW BAND INITIATING NEAR THE APOSTLE ISLANDS ALONG THE SFC TROF. LOCAL HIRES WRF RUN AND CANADIAN HIGH RES RUNS BOTH HAVE A HIGHER PCPN SIGNATURE IN KEWEENAW COUNTY. SO...LES ADVYS WILL REMAIN UP FROM GOGEBIC COUNTY THRU THE KEWEENAW. MARQUETTE/ALGER COUNTIES WILL ALSO BE ADDED. THE FACT THAT THE HVY SNOW/GUSTY WINDS ARRIVE JUST BEFORE AND DURING THE MORNING COMMUTE SHOULD LEAD TO ESPECIALLY DIFFICULT DRIVING CONDITIONS TUE MORNING FOR MARQUETTE/ALGER COUNTIES. MAY NEED TO CONSIDER ADDING NRN SCHOOLCRAFT/LUCE COUNTIES TO ADVY FOR TUE...BUT RIGHT NOW HAVE SNOW ACCUMULATIONS NEAR/JUST UNDER ADVY CRITIERIA. WIND PARALLEL LES BANDS WILL SET UP A FEW HRS AFTER THE TROF PASSES AND WILL THEN SLOWLY SHIFT THRU THE DAY TUE AS WINDS BACK WNW OVER WRN LAKE SUPERIOR AND NW OVER ERN LAKE SUPERIOR. TOTAL SNOW ACCUMULATIONS TONIGHT/TUE WILL GENERALLY RANGE FROM 2 TO 7 INCHES ALONG LAKE SUPERIOR WITH HIGHEST AMOUNTS VCNTY OF THE PORCUPINE MTNS AND JUST E OF MARQUETTE TO PICTURED ROCKS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 502 PM EST MON JAN 11 2016 NW WINDS WILL CONTINUE TUESDAY NIGHT WITH AN ADDITIONAL 2-5IN EXPECTED FROM THE PORCUPINE MTNS UP THROUGH CALUMET...AND THEN NE OF A LINE FROM MUNISING TO NEWBERRY. MOISTURE QUICKLY SHIFTS N WEDNESDAY AS A MORE W WIND TAKES OVER...LIMITING ADDITIONAL SNOW AMOUNTS TO THE KEWEENAW AND THEN RIGHT ALONG THE LAKE SUPERIOR SHORELINE FROM GRAND MARAIS TO WHITEFISH POINT. THIS WILL BE ALL WHILE THE MAIN SFC LOW EXITS FROM THE LOWER GREAT LAKES TO THE NEW ENGLAND STATES...AND RIDGING TRIES TO PUSH IN FROM THE SW. A TROUGH LOOKS TO LINGER ACROSS CENTRAL AND E LAKE SUPERIOR...ALONG WITH 850MB TEMPS OF -15 TO -22C...AND AN ELONGATED SHORTWAVE IN THE NW FLOW ALOFT...KEEPING LES GOING. KEPT ONLY CHANCE LES FOR WEDNESDAY NIGHT OVER THE KEWEENAW AS THE BEST MOISTURE EXITS AND SLIGHT RIDGING TAKES PLACE AT 500MB. THERE IS SOME POTENTIAL FOR WAA SNOW THURSDAY OUT AHEAD OF THE ORGANIZING SFC LOW TO OUR W AND SW. BETTER DETAILS ARE EXPECTED WITH THIS FEATURE...AND A QUICK BURST OF SNOW OVER THE S HALF OF THE CWA COULD BE POSSIBLE. TIMING FOR WHEN AND WHERE THE EJECTING SFC LOW WILL BE LATE THIS WEEK AND EARLY THIS WEEKEND ARE SILL A CONCERN. AT 18Z FRIDAY THE LOW IS CENTERED SOMEWHERE BETWEEN IL AND AR...AND COULD MOVE OVER THE GREAT LAKES AND OFF THE EASTERN SEABORARD BY 12Z SATURDAY. THIS QUICKER SOLUTION IS OFF THE 12Z ECMWF. A WETTER SOLUTION FOR US IS A SLOWER MORE W TRACK...SIMILAR TO THE GFS AND CANADIAN WITH THE THE LOW OVER IN AT 12Z SATURDAY. EITHER WAY...WE MAY HAVE A PERIOD OF N WINDS LATE CENTERING SOME SNOW SHOWERS ACROSS N CENTRAL UPPER MI FRIDAY NIGHT-SATURDAY. INCLUDED LIKELY POPS FOR SATURDAY...BEFORE TRANSITIONING TO A MORE NNW-NW FLOW PATTERN AGAIN SATURDAY NIGHT ON. FEW OTHER CHANGES WERE MADE TO A BLENDED SOLUTION IN THE DAYS 4-7 FCST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 641 PM EST MON JAN 11 2016 A LOW PRES TROF WILL DROP S ACROSS LAKE SUPERIOR AND INTO UPPER MI...BRINGING A WSHFT FROM SW TO THE NNW. WHILE THERE MAY BE SOME -SN WITH MVFR/IFR CONDITIONS AHEAD OF IT...IN ITS WAKE...HEAVY LAKE EFFECT SNOW SHOWERS WILL BRING A PERIOD OF LIFR CONDITIONS TO ALL TERMINALS OVERNIGHT/EARLY TUE MORNING. ALTHOUGH CONDITIONS WILL LIKELY REMAIN A PREVAILING LIFR AT KIWD/KCMX TUE MORNING...SLIGHT BACKING OF WINDS SHOULD SHIFT HEAVIER SNOW SHOWERS E OF KSAW LATE IN THE MORNING...RESULTING IN A RETURN OF MVFR CONDITIONS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 502 PM EST MON JAN 11 2016 MUCH OF THIS PERIOD WILL BE MARKED BY AN AREA OF LOW PRESSURE OVER LAKE SUPERIOR. LOW PRESSURE INITIALLY ACROSS LAKE SUPERIOR AND WI WILL DEEPEN OVER S LAKE HURON BY TUESDAY MORNING. NNW WINDS TO 30 KTS EXPECTED TONIGHT...WITH WITH SOME GALE FORCE GUSTS UP TO 35 KTS. THE LOW WILL EXIT ALONG S QUEBEC AND THE NEW ENGLAND STATES LATE IN THE DAY...AS THE LINGERING TROUGH OVER LAKE SUPERIOR WEAKENS SLIGHTLY AND HIGH PRESSURE BUILDS INTO THE MISSISSIPPI VALLEY TUESDAY NIGHT INTO WEDNESDAY. ANOTHER ROUND OF COLD AIR SINKING IN WILL BRING ANOTHER PERIOD OF HEAVY FREEZING SPRAY TO W AND N CENTRAL LAKE SUPERIOR LATE TONIGHT AND TUESDAY. LOW PRESSURE OVER FAR N MANITOBA...AND AN ADDITIONAL LOW OVER S ALBERTA WEDNESDAY EVENING WILL COMBINE AND SETTLE ACROSS THE CENTRAL PLAINS THURSDAY NIGHT. EXPECT THE SURFACE LOW TO LIFT NORTHEAST ACROSS THE LOWER GREAT LAKES SATURDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY FROM 5 AM TO 7 PM EST TUESDAY FOR MIZ006. LAKE EFFECT SNOW ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING TO 4 PM EST /3 PM CST/ TUESDAY FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY FROM 5 AM TO 1 PM EST TUESDAY FOR MIZ005. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING FROM 3 AM TO 3 PM EST TUESDAY FOR LSZ248-249-265-266. HEAVY FREEZING SPRAY WARNING FROM 2 AM EST /1 AM CST/ TO 1 PM EST /NOON CST/ TUESDAY FOR LSZ241>244-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
257 PM EST SUN JAN 10 2016 .UPDATE... ISSUED AT 712 AM EST SUN JAN 10 2016 LATEST MQT RADAR SHOWS A NEARLY STNRY LES BAND WITH REFLECTIVIES AS HI AS 30 DBZ STRETCHING FM MARQUETTE TO JUST E OF GWINN IN FAVORABLE 340 DEGREE LLVL FLOW SHOWN ON THE MQT RADAR VWP. SINCE THIS BAND IS LIKELY TO MOVE ONLY SLOWLY THRU THIS MRNG...OPTED TO ISSUE AN ADVY. HAD A PUBLIC REPORT OF 3 INCHES ACCUM NEAR HARVEY...CONSISTENT WITH RADAR ESTIMATES OF AN INCH OR MORE AN HOUR UNDER THIS BAND. CARRIED THE ADVY THRU 18Z TODAY...WHEN SLOWLY BACKING WINDS WL SHIFT THE BAND INTO WRN ALGER COUNTY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 506 AM EST SUN JAN 10 2016 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A DEEP UPR TROF IN CENTRAL NAMERICA DOWNSTREAM OF A HI AMPLITUDE RDG ALONG THE W COAST. A SHRTWV EMBEDDED IN THE ARCTIC BRANCH FLOW IS OVER NW WI AND SUPPORTING AN AREA OF DEEP LYR QVECTOR CNVGC/DEEPER MSTR OVER MAINLY THE E HALF OF THE CWA...WHERE SOME STEADY LIGHT SN IS FALLING UNDER ASSOCIATED COLDER CLD TOPS. SINCE H85 TEMPS HAVE FALLEN UNDER -15C OVER THE E HALF OF LK SUP IN LLVL NNW FLOW AND UNDER THE UPR FORCING...RADAR SHOWS SOME STRONGER LK ENHANCED BANDS ARE MOVING INTO ALGER COUNTY...WHERE THE PREVIOUS SHIFT HAD ISSUED AN LES ADVY...AND ERN MARQUETTE COUNTY. SFC OBS ALSO INDICATE THERE IS SOME LES STREAMING INTO THE WRN CWA TO THE E OF -25C H85 THERMAL TROF STRETCHING FM YPL TO INL...BUT LO INVRN BASE NEAR H9 AS WELL AS SOME DRY LLVL AIR /SFC DEWPTS IN NRN MN ARE AS LO AS -20F/ SHOWN ON THE 00Z INL ROAB ARE LIMITING THE INTENSITY OF THIS PURE LES DESPITE SOME DECENT LLVL CNVGC EVIDENT IN ONTONAGON/GOGEBIC COUNTIES. THERE IS ANOTHER SHRTWV MOVING NEWD THRU THE POLAR BRANCH FLOW FARTHER S IN THE OHIO RIVER VALLEY...SUPPORTING AN AREA OF LO PRES/COLDER CLD TOPS AND WIDESPREAD PCPN THAT IS MOVING INTO LOWER MI. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LES TRENDS/NEED FOR HEADLINES AND VERY LO TEMPS EXPECTED TNGT AS H85 THERMAL TROF PASSES THRU THE CWA. TODAY...SINCE THE APRCHG ARCTIC BRANCH SHRTWV IS NOT FCST TO PHASE WITH THE POLAR BRANCH DISTURBANCE TO THE S MOVING NEWD...EXPECT WDSPRD LIGHT SN IMPACTING THE ERN CWA EARLY THIS MRNG TO END ARND 12Z SUN AT NEWBERRY AS MUCH DRIER AIR BEGINS TO MOVE E FOLLOWING PASSAGE OF ARCTIC BRANCH SHRTWV TO THE E. BUT INFLUX OF VERY COLD H85 AIR UPSTREAM IN MN WL SUPPORT CONTINUED PURE LES. THERE ARE SEVERAL FACTORS THAT WL LIMIT THE OVERALL INTENSITY OF THIS LES. THE FIRST IS THE VERY DRY NATURE OF THE UPSTREAM AIRMASS. INCREASING CHILL WITH H85 TEMPS FCST AS LO AS -23C OVER THE NW HALF OF THE CWA AT 00Z MON WL ALSO CAUSE THE DGZ TO FALL WITHIN ABOUT 1K FT AGL OVER THE W...WHERE MODELS SHOW THE SHARPEST LLVL CNVGC. SHORTER FETCH TO MOISTEN THE LLVLS INTO THE SHARPER CNVGC FCST TO REMAIN OVER ONTONAGON/GOGEBIC COUNTIES...INVRN BASE LINGERING NEAR 5K FT AGL AND THE INCRSGLY POOR SN GROWTH WL ACT TO COUNTER THE SHARPER LLVL CNVGC AND HOLD ACCUMS IN CHECK. FARTHER TO THE E...LLVL NNW WIND THIS MRNG WL FAVOR THE W HALF OF ALGER COUNTY AND ERN MQT COUNTY...BUT ABSENCE OF SHARPER LLVL CNVGC AND SIMILARLY LO INVRN BASE WL OFFSET THE BETTER SN GROWTH THAT WL PERSIST HERE THIS MRNG BEFORE THE ARRIVAL OF COLDER AIR LOWERS THE DGZ A BIT. BY THIS AFTN...THE LLVL FLOW IS ALSO FCST TO BACK SLOWLY TOWARD THE NW...SHIFTING THE LES BANDS AND LIMITING RESIDENCE TIME. DESPITE THESE LIMITING FACTORS...OPTED TO ISSUE AN SPS TO COVER THE SN BANDS OVER ERN MARQUETTE COUNTY THRU THE MRNG AND CONTINUE THE ADVY FOR ALGER THRU THE DAY TO ACCOUNT FOR THE WELL DEFINED LES BANDS AS SHOWN ON RADAR IMAGERY. AS FOR TEMPS...INFLUX OF VERY COLD AIR WL LIMIT ANY DIURNAL TEMP RECOVERY. EXPECT MAX TEMPS OVER W HALF TO HOLD IN THE 5 TO 10F RANGE. INCRSG WINDS TODAY ON THE WRN FLANK OF DEEPENING LO PRES PASSING WELL TO THE E WL CAUSE SOME BLSN AS WELL ESPECIALLY NEAR LK SUP OVER THE E HALF...CLOSER TO THE SFC LO PRES. TNGT...AS THE DEEPER LO PRES EXITS TO THE NE THRU QUEBEC AND SFC HI PRES MOVES TOWARD THE OH RIVER VALLEY...THE LLVL FLOW IS FCST TO BACK STEADILY TOWARD THE W OVER THE WRN CWA AND TO A MORE WNW DIRECTION OVER THE E. HIER RES MODELS INDICATE AN AXIS OF SHARPER LLVL CNVGC WL IMPACT NRN ONTONAGON/CENTRAL HOUGHTON COUNTIES AS WELL AS ERN ALGER/NRN LUCE COUNTIES ALONG A LK INDUCED TROF AND ACCENTUATED BY LAND BREEZE FLOW OUT OF VERY COLD AIRMASS THAT WL MOVE INTO THE WI BORDER COUNTIES...WHERE LK MODERATION OF THE ARCTIC CHILL WL BE ABSENT IN THE MORE W LLVL FLOW AND LO TEMPS WL AT LEAST APRCH -10F. CONCERNED LES ACCUMS OVER THE W IMPACTED BY THE SHARPER LLVL CNVGC MAY AT LEAST APRCH ADVY CRITERIA. BUT SIMILAR NEGATIVES INCLUDING FCST LO INVRN BASE UNDER DEEP LYR QVECTOR DVGC...VERY COLD/DRY AIR AND LO DGZ AS WELL AS THE SHIFTING WINDS LOWER CONFIDENCE FOR ISSUING NEW HEADLINES OVER THE WRN CWA. OVER THE E...NAM FCST SDNGS SHOW MORE SGNFT MOISTENING AND EVEN A LIFTING OF THE INVRN BASE ACCOMPANYING SOME FAIRLY SHARP UVV THAT COINCIDES WITH A HIER DGZ MAINTAINED BY LONGER FETCH ACRS THE WARMING INFLUENCE OF LK SUP. BASED ON THESE CONDITIONS AND POTENTIAL FOR SOME FOCUSED LLVL CNVGC...EXTENDED THE ADVY FOR ALGER COUNTY THRU THE NGT AND ISSUED ONE FOR LUCE COUNTY THAT WL EXTEND INTO MON MRNG. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 256 PM EST SUN JAN 10 2016 NAM SHOWS A SHORTWAVE OVER THE UPPER GREAT LAKES 00Z TUE WHICH IS EMBEDDED IN A BROAD TROUGH OVER THE EASTERN HALF OF THE U.S. THIS SHORTWAVE MOVES THROUGH MON NIGHT AND THEN THE AREA REMAINS IN THE BROAD TROUGH THROUGH WED. NAM SHOWS SOME DEEPER MOISTURE AND 850-500 MB Q-VECTOR CONVERGENCE MOVING THROUGH THE U.P. MON NIGHT AND BOTH MOVE OUT ON TUE BEFORE RETURNING LATE WED. GFS AND ECMWF SHOW ABOUT THE SAME THING. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST OVERALL WITH LAKE EFFECT SNOW SHOWERS CONTINUING THROUGH THE FORECAST PERIOD AND WILL BE HIGHLY DEPENDENT ON THE WIND DIRECTION WHICH IS MOSTLY FROM THE NORTHWEST AND WEST DIRECTIONS THIS FORECAST PERIOD WITH THE HIGHEST POPS IN THE LAKE SUPERIOR LAKE EFFECT SNOW BELTS. IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH ACROSS THE EASTERN HALF OF NORTH AMERICA WITH COLD AIR EMBEDDED IN IT 12Z THU. 850 MB TEMPERATURES AT THAT TIME ARE AROUND -18C. AIRMASS SLOWLY MODIFIES THIS FORECAST PERIOD...BUT AREA STILL REMAINS IN THE UPPER LEVEL TROUGH INTO SUN. BELOW NORMAL TEMPERATURES WILL SLOWLY MODIFY THIS FORECAST PERIOD AND LAKE EFFECT SNOW WILL CONTINUE AS WELL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 200 PM EST SUN JAN 10 2016 BANDS OF LES CONTINUE TO IMPACT ALL 3 TAF SITES...WITH VIS FALLING TO LIFR AT TIMES AND CEILINGS IFR TO MAINLY MVFR. IWD CONTINUES TO BE RIGHT ON THE EDGE OF THESE LES BANDS...RESULTING IN A MORE DIFFICULT FCST THERE. EXPECT THE DRY AIR TO WIN OVERNIGHT AS THE DOMINANT NW WINDS BECOME MORE W AND DRIFT N OF IWD AND E OF SAW. BETTER CONVERGENT WINDS AT CMX WILL KEEP THEM MAINLY IN THEN IFR CATEGORY THROUGH THE PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 506 AM EST SUN JAN 10 2016 EXPECT NORTH TO NORTHWEST GALE FORCE GUSTS UP TO 35 KTS INTO THIS EVNG OVER THE E HALF OF LK SUP UNDER A SHARP PRES GRADIENT BTWN A DEEPENING LO PRES MOVING THRU SE CANADA AND HI PRES IN THE PLAINS. THE INFLUX OF VERY COLD AIR ASSOCIATED WITH THESE STRONG WINDS WL RESULT IN SUFFICIENTLY HI WAVES TO GENERATE HEAVY FREEZING SPRAY OVER MUCH OF THE LAKE. AS THE PRES GRADIENT WEAKENS TONIGHT... EXPECT THE GALES AND HEAVY FREEZING SPRAY TO SUBSIDE. THERE MAY BE ANOTHER WIDESPREAD GALE EVENT ON TUE AS A DEEPENING SFC LO PRES PASSING TO THE S TIGHTENS THE GRADIENT AND INCREASES THE N WIND. THERE WL LIKELY BE MORE HEAVY FREEZING SPRAY AS WELL WITH ANOTHER ARCTIC AIR INVASION. WINDS WL DIMINISH ON WED AND THU AS A WEAKER PRES GRADIENT DEVELOPS OVER THE UPPER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST MONDAY FOR MIZ006. LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY FOR MIZ007. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST MONDAY FOR LSZ264- 266-267. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ249>251-266-267. HEAVY FREEZING SPRAY WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ248>251. HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ244-245. HEAVY FREEZING SPRAY WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ263. LAKE MICHIGAN... GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ221-248-250. && $$ UPDATE...KC SHORT TERM...KC LONG TERM...07 AVIATION...KF MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
200 PM EST SUN JAN 10 2016 .UPDATE... ISSUED AT 712 AM EST SUN JAN 10 2016 LATEST MQT RADAR SHOWS A NEARLY STNRY LES BAND WITH REFLECTIVIES AS HI AS 30 DBZ STRETCHING FM MARQUETTE TO JUST E OF GWINN IN FAVORABLE 340 DEGREE LLVL FLOW SHOWN ON THE MQT RADAR VWP. SINCE THIS BAND IS LIKELY TO MOVE ONLY SLOWLY THRU THIS MRNG...OPTED TO ISSUE AN ADVY. HAD A PUBLIC REPORT OF 3 INCHES ACCUM NEAR HARVEY...CONSISTENT WITH RADAR ESTIMATES OF AN INCH OR MORE AN HOUR UNDER THIS BAND. CARRIED THE ADVY THRU 18Z TODAY...WHEN SLOWLY BACKING WINDS WL SHIFT THE BAND INTO WRN ALGER COUNTY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 506 AM EST SUN JAN 10 2016 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A DEEP UPR TROF IN CENTRAL NAMERICA DOWNSTREAM OF A HI AMPLITUDE RDG ALONG THE W COAST. A SHRTWV EMBEDDED IN THE ARCTIC BRANCH FLOW IS OVER NW WI AND SUPPORTING AN AREA OF DEEP LYR QVECTOR CNVGC/DEEPER MSTR OVER MAINLY THE E HALF OF THE CWA...WHERE SOME STEADY LIGHT SN IS FALLING UNDER ASSOCIATED COLDER CLD TOPS. SINCE H85 TEMPS HAVE FALLEN UNDER -15C OVER THE E HALF OF LK SUP IN LLVL NNW FLOW AND UNDER THE UPR FORCING...RADAR SHOWS SOME STRONGER LK ENHANCED BANDS ARE MOVING INTO ALGER COUNTY...WHERE THE PREVIOUS SHIFT HAD ISSUED AN LES ADVY...AND ERN MARQUETTE COUNTY. SFC OBS ALSO INDICATE THERE IS SOME LES STREAMING INTO THE WRN CWA TO THE E OF -25C H85 THERMAL TROF STRETCHING FM YPL TO INL...BUT LO INVRN BASE NEAR H9 AS WELL AS SOME DRY LLVL AIR /SFC DEWPTS IN NRN MN ARE AS LO AS -20F/ SHOWN ON THE 00Z INL ROAB ARE LIMITING THE INTENSITY OF THIS PURE LES DESPITE SOME DECENT LLVL CNVGC EVIDENT IN ONTONAGON/GOGEBIC COUNTIES. THERE IS ANOTHER SHRTWV MOVING NEWD THRU THE POLAR BRANCH FLOW FARTHER S IN THE OHIO RIVER VALLEY...SUPPORTING AN AREA OF LO PRES/COLDER CLD TOPS AND WIDESPREAD PCPN THAT IS MOVING INTO LOWER MI. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LES TRENDS/NEED FOR HEADLINES AND VERY LO TEMPS EXPECTED TNGT AS H85 THERMAL TROF PASSES THRU THE CWA. TODAY...SINCE THE APRCHG ARCTIC BRANCH SHRTWV IS NOT FCST TO PHASE WITH THE POLAR BRANCH DISTURBANCE TO THE S MOVING NEWD...EXPECT WDSPRD LIGHT SN IMPACTING THE ERN CWA EARLY THIS MRNG TO END ARND 12Z SUN AT NEWBERRY AS MUCH DRIER AIR BEGINS TO MOVE E FOLLOWING PASSAGE OF ARCTIC BRANCH SHRTWV TO THE E. BUT INFLUX OF VERY COLD H85 AIR UPSTREAM IN MN WL SUPPORT CONTINUED PURE LES. THERE ARE SEVERAL FACTORS THAT WL LIMIT THE OVERALL INTENSITY OF THIS LES. THE FIRST IS THE VERY DRY NATURE OF THE UPSTREAM AIRMASS. INCREASING CHILL WITH H85 TEMPS FCST AS LO AS -23C OVER THE NW HALF OF THE CWA AT 00Z MON WL ALSO CAUSE THE DGZ TO FALL WITHIN ABOUT 1K FT AGL OVER THE W...WHERE MODELS SHOW THE SHARPEST LLVL CNVGC. SHORTER FETCH TO MOISTEN THE LLVLS INTO THE SHARPER CNVGC FCST TO REMAIN OVER ONTONAGON/GOGEBIC COUNTIES...INVRN BASE LINGERING NEAR 5K FT AGL AND THE INCRSGLY POOR SN GROWTH WL ACT TO COUNTER THE SHARPER LLVL CNVGC AND HOLD ACCUMS IN CHECK. FARTHER TO THE E...LLVL NNW WIND THIS MRNG WL FAVOR THE W HALF OF ALGER COUNTY AND ERN MQT COUNTY...BUT ABSENCE OF SHARPER LLVL CNVGC AND SIMILARLY LO INVRN BASE WL OFFSET THE BETTER SN GROWTH THAT WL PERSIST HERE THIS MRNG BEFORE THE ARRIVAL OF COLDER AIR LOWERS THE DGZ A BIT. BY THIS AFTN...THE LLVL FLOW IS ALSO FCST TO BACK SLOWLY TOWARD THE NW...SHIFTING THE LES BANDS AND LIMITING RESIDENCE TIME. DESPITE THESE LIMITING FACTORS...OPTED TO ISSUE AN SPS TO COVER THE SN BANDS OVER ERN MARQUETTE COUNTY THRU THE MRNG AND CONTINUE THE ADVY FOR ALGER THRU THE DAY TO ACCOUNT FOR THE WELL DEFINED LES BANDS AS SHOWN ON RADAR IMAGERY. AS FOR TEMPS...INFLUX OF VERY COLD AIR WL LIMIT ANY DIURNAL TEMP RECOVERY. EXPECT MAX TEMPS OVER W HALF TO HOLD IN THE 5 TO 10F RANGE. INCRSG WINDS TODAY ON THE WRN FLANK OF DEEPENING LO PRES PASSING WELL TO THE E WL CAUSE SOME BLSN AS WELL ESPECIALLY NEAR LK SUP OVER THE E HALF...CLOSER TO THE SFC LO PRES. TNGT...AS THE DEEPER LO PRES EXITS TO THE NE THRU QUEBEC AND SFC HI PRES MOVES TOWARD THE OH RIVER VALLEY...THE LLVL FLOW IS FCST TO BACK STEADILY TOWARD THE W OVER THE WRN CWA AND TO A MORE WNW DIRECTION OVER THE E. HIER RES MODELS INDICATE AN AXIS OF SHARPER LLVL CNVGC WL IMPACT NRN ONTONAGON/CENTRAL HOUGHTON COUNTIES AS WELL AS ERN ALGER/NRN LUCE COUNTIES ALONG A LK INDUCED TROF AND ACCENTUATED BY LAND BREEZE FLOW OUT OF VERY COLD AIRMASS THAT WL MOVE INTO THE WI BORDER COUNTIES...WHERE LK MODERATION OF THE ARCTIC CHILL WL BE ABSENT IN THE MORE W LLVL FLOW AND LO TEMPS WL AT LEAST APRCH -10F. CONCERNED LES ACCUMS OVER THE W IMPACTED BY THE SHARPER LLVL CNVGC MAY AT LEAST APRCH ADVY CRITERIA. BUT SIMILAR NEGATIVES INCLUDING FCST LO INVRN BASE UNDER DEEP LYR QVECTOR DVGC...VERY COLD/DRY AIR AND LO DGZ AS WELL AS THE SHIFTING WINDS LOWER CONFIDENCE FOR ISSUING NEW HEADLINES OVER THE WRN CWA. OVER THE E...NAM FCST SDNGS SHOW MORE SGNFT MOISTENING AND EVEN A LIFTING OF THE INVRN BASE ACCOMPANYING SOME FAIRLY SHARP UVV THAT COINCIDES WITH A HIER DGZ MAINTAINED BY LONGER FETCH ACRS THE WARMING INFLUENCE OF LK SUP. BASED ON THESE CONDITIONS AND POTENTIAL FOR SOME FOCUSED LLVL CNVGC...EXTENDED THE ADVY FOR ALGER COUNTY THRU THE NGT AND ISSUED ONE FOR LUCE COUNTY THAT WL EXTEND INTO MON MRNG. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 352 AM EST SUN JAN 10 2016 AFTER A WARM DECEMBER AND FIRST WEEK OF JANUARY...THE AREA IS TRANSITIONING TO A MORE WINTER LIKE PATTERN TODAY AND THAT IS EXPECTED TO CONTINUE THROUGH THE LONG TERM FORECAST. TEMPERATURES WILL BE BELOW NORMAL THROUGH MUCH OF THE PERIOD (ALTHOUGH SOME MODERATION TOWARDS MORE NORMAL VALUES IS EXPECT BY THE END OF THE WEEK) AND PERIODS OF LAKE EFFECT AND SYNOPTIC SNOW WILL OCCUR INTO NEXT WEEKEND. THIS WEEK/S WEATHER WILL BE DRIVEN BY THE UPPER TROUGH NOW DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY. THE TROUGH WILL MOVE THROUGH THE GREAT LAKES REGION ON MONDAY AND THEN BECOME REINFORCED BY A SECONDARY WAVE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT AS THE FIRST WAVE LIFTS NORTHEAST. THIS WILL KEEP 850MB TEMPS BETWEEN -19C AND -23C FROM MONDAY THROUGH WEDNESDAY. WITH LAKE SUPERIOR TEMPERATURES STILL AROUND 3-4C...THERE WILL BE PLENTY OF OVER THE LAKE INSTABILITY...BUT THE AMOUNT OF COLD AIR WILL KEEP MUCH OF THE CLOUD LAYER ABOVE THE DGZ. THAT WILL LEAD TO SMALLER SNOW FLAKES/RATIOS AND LIMIT THE SNOWFALL AMOUNTS SOME FOR MUCH OF THE WEEK. STARTING ON MONDAY...WINDS WILL BE BACKING QUICKLY TO THE WEST DURING THE MORNING HOURS AS THE SURFACE RIDGE SLIDES ACROSS UPPER MICHIGAN. EXPECT THE LAKE EFFECT TO FOLLOW SUIT AND MOVE OVER THE WESTERLY FAVORED AREAS IN THE MORNING AND THEN SHIFT OFFSHORE OVER THE EAST IN THE AFTERNOON AS THE RIDGE SHIFTS EAST AND WINDS TURN SOUTHWESTERLY AHEAD OF THE APPROACHING SHORTWAVE AND DEVELOPING SURFACE LOW. AS THE SHORTWAVE DIVES JUST TO THE SOUTH OF THE U.P. MONDAY NIGHT...IT WILL STRENGTHEN A LOW OVER CENTRAL LAKE MICHIGAN WITH A INVERTED TROUGH STRETCHING NORTHWEST OVER LAKE SUPERIOR. THE LOW WILL CONTINUE TO STRENGTHEN AS IT MOVES OVER LAKE HURON TUESDAY MORNING...WHILE THE TROUGH DROPS SOUTH OF LAKE SUPERIOR. THAT TROUGH WILL BE THE FOCUS OF AN ENHANCED BAND OF SNOW AIDED BY THE INCREASED CONVERGENCE AND SIGNIFICANTLY RISING INVERSION HEIGHTS (RISING TO 11- 12KFT). EXPECT THE HEAVY SNOW AND GREATLY INCREASING NORTHERLY WINDS TO AFFECT THE WESTERN U.P. AROUND OR SHORTLY AFTER 06Z TUESDAY AND THEN BETWEEN 9-12Z TUESDAY FOR THE NORTH CENTRAL. EXPECT A VERY STRONG BURST OF SNOW FOR A 3-6HR PERIOD ALONG AND RIGHT AFTER THE TROUGH MOVES THROUGH AND THEN MODERATE NORTH- NORTHWEST LAKE EFFECT THROUGH TUESDAY AFTERNOON. ALONG WITH THE HEAVY SNOW...EXPECT A SHARP INCREASE IN THE WINDS OUT OF THE NORTH ALONG THE TROUGH...WITH GUSTS IN THE 25-30KT RANGE. THE COMBINATION OF THE WIND AND SNOW WILL LEAD TO VERY POOR TRAVEL AND VISIBILITIES FOR PORTIONS OF WESTERN AND NORTH CENTRAL UPPER MICHIGAN LATE MONDAY NIGHT INTO TUESDAY MORNING. WITH THE CONSISTENT SIGNAL IN THIS IDEA OVER THE LAST 24-36HRS...WILL BEEF UP THE WORDING IN THE HWO AS SOME AREAS MAY END UP NEEDING WINTER STORM WARNINGS FOR THE COMBINED IMPACTS OF THE SNOW/WIND. AFTER THE LOW AND TROUGH DEPART...A HIGH PRESSURE RIDGE OVER THE UPPER MISSISSIPPI VALLEY WILL SLOWLY NOSE TOWARDS THE AREA AS THE PARENT HIGH SHIFTS INTO THE SOUTHEASTERN STATES. THAT WILL LEAD TO SLOWLY LOWERING INVERSION HEIGHTS THROUGH WEDNESDAY AS WINDS BACK TO THE WEST. WILL SHOW THAT SLOW TRANSITION IN THE POPS AND LESSER SNOWFALL AMOUNTS THROUGH WEDNESDAY NIGHT. THE FORECAST BECOMES UNCERTAIN FOR THE END OF NEXT WEEK AS THE MODELS ARE SHOWING SOME VARIABILITY IN THE EVOLUTION OF THE UPPER TROUGH OFF TO THE EAST OF THE AREA AND WEAK WAVES BRUSHING THE AREA. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE MODELS IN SHOWING TEMPERATURES GRADUALLY WARMING TOWARDS MORE NORMAL VALUES (UPPER TEENS AND LOWER 20S) WITH OCCASIONAL CHANCES FOR SNOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 200 PM EST SUN JAN 10 2016 BANDS OF LES CONTINUE TO IMPACT ALL 3 TAF SITES...WITH VIS FALLING TO LIFR AT TIMES AND CEILINGS IFR TO MAINLY MVFR. IWD CONTINUES TO BE RIGHT ON THE EDGE OF THESE LES BANDS...RESULTING IN A MORE DIFFICULT FCST THERE. EXPECT THE DRY AIR TO WIN OVERNIGHT AS THE DOMINANT NW WINDS BECOME MORE W AND DRIFT N OF IWD AND E OF SAW. BETTER CONVERGENT WINDS AT CMX WILL KEEP THEM MAINLY IN THEN IFR CATEGORY THROUGH THE PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 506 AM EST SUN JAN 10 2016 EXPECT NORTH TO NORTHWEST GALE FORCE GUSTS UP TO 35 KTS INTO THIS EVNG OVER THE E HALF OF LK SUP UNDER A SHARP PRES GRADIENT BTWN A DEEPENING LO PRES MOVING THRU SE CANADA AND HI PRES IN THE PLAINS. THE INFLUX OF VERY COLD AIR ASSOCIATED WITH THESE STRONG WINDS WL RESULT IN SUFFICIENTLY HI WAVES TO GENERATE HEAVY FREEZING SPRAY OVER MUCH OF THE LAKE. AS THE PRES GRADIENT WEAKENS TONIGHT... EXPECT THE GALES AND HEAVY FREEZING SPRAY TO SUBSIDE. THERE MAY BE ANOTHER WIDESPREAD GALE EVENT ON TUE AS A DEEPENING SFC LO PRES PASSING TO THE S TIGHTENS THE GRADIENT AND INCREASES THE N WIND. THERE WL LIKELY BE MORE HEAVY FREEZING SPRAY AS WELL WITH ANOTHER ARCTIC AIR INVASION. WINDS WL DIMINISH ON WED AND THU AS A WEAKER PRES GRADIENT DEVELOPS OVER THE UPPER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST MONDAY FOR MIZ006. LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY FOR MIZ007. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST MONDAY FOR LSZ264- 266-267. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ249>251-266-267. HEAVY FREEZING SPRAY WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ248>251. HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ244-245. HEAVY FREEZING SPRAY WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ263. LAKE MICHIGAN... GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ221-248-250. && $$ UPDATE...KC SHORT TERM...KC LONG TERM...SRF AVIATION...KF MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
712 AM EST SUN JAN 10 2016 .UPDATE... ISSUED AT 712 AM EST SUN JAN 10 2016 LATEST MQT RADAR SHOWS A NEARLY STNRY LES BAND WITH REFLECTIVIES AS HI AS 30 DBZ STRETCHING FM MARQUETTE TO JUST E OF GWINN IN FAVORABLE 340 DEGREE LLVL FLOW SHOWN ON THE MQT RADAR VWP. SINCE THIS BAND IS LIKELY TO MOVE ONLY SLOWLY THRU THIS MRNG...OPTED TO ISSUE AN ADVY. HAD A PUBLIC REPORT OF 3 INCHES ACCUM NEAR HARVEY...CONSISTENT WITH RADAR ESTIMATES OF AN INCH OR MORE AN HOUR UNDER THIS BAND. CARRIED THE ADVY THRU 18Z TODAY...WHEN SLOWLY BACKING WINDS WL SHIFT THE BAND INTO WRN ALGER COUNTY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 506 AM EST SUN JAN 10 2016 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A DEEP UPR TROF IN CENTRAL NAMERICA DOWNSTREAM OF A HI AMPLITUDE RDG ALONG THE W COAST. A SHRTWV EMBEDDED IN THE ARCTIC BRANCH FLOW IS OVER NW WI AND SUPPORTING AN AREA OF DEEP LYR QVECTOR CNVGC/DEEPER MSTR OVER MAINLY THE E HALF OF THE CWA...WHERE SOME STEADY LIGHT SN IS FALLING UNDER ASSOCIATED COLDER CLD TOPS. SINCE H85 TEMPS HAVE FALLEN UNDER -15C OVER THE E HALF OF LK SUP IN LLVL NNW FLOW AND UNDER THE UPR FORCING...RADAR SHOWS SOME STRONGER LK ENHANCED BANDS ARE MOVING INTO ALGER COUNTY...WHERE THE PREVIOUS SHIFT HAD ISSUED AN LES ADVY...AND ERN MARQUETTE COUNTY. SFC OBS ALSO INDICATE THERE IS SOME LES STREAMING INTO THE WRN CWA TO THE E OF -25C H85 THERMAL TROF STRETCHING FM YPL TO INL...BUT LO INVRN BASE NEAR H9 AS WELL AS SOME DRY LLVL AIR /SFC DEWPTS IN NRN MN ARE AS LO AS -20F/ SHOWN ON THE 00Z INL ROAB ARE LIMITING THE INTENSITY OF THIS PURE LES DESPITE SOME DECENT LLVL CNVGC EVIDENT IN ONTONAGON/GOGEBIC COUNTIES. THERE IS ANOTHER SHRTWV MOVING NEWD THRU THE POLAR BRANCH FLOW FARTHER S IN THE OHIO RIVER VALLEY...SUPPORTING AN AREA OF LO PRES/COLDER CLD TOPS AND WIDESPREAD PCPN THAT IS MOVING INTO LOWER MI. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LES TRENDS/NEED FOR HEADLINES AND VERY LO TEMPS EXPECTED TNGT AS H85 THERMAL TROF PASSES THRU THE CWA. TODAY...SINCE THE APRCHG ARCTIC BRANCH SHRTWV IS NOT FCST TO PHASE WITH THE POLAR BRANCH DISTURBANCE TO THE S MOVING NEWD...EXPECT WDSPRD LIGHT SN IMPACTING THE ERN CWA EARLY THIS MRNG TO END ARND 12Z SUN AT NEWBERRY AS MUCH DRIER AIR BEGINS TO MOVE E FOLLOWING PASSAGE OF ARCTIC BRANCH SHRTWV TO THE E. BUT INFLUX OF VERY COLD H85 AIR UPSTREAM IN MN WL SUPPORT CONTINUED PURE LES. THERE ARE SEVERAL FACTORS THAT WL LIMIT THE OVERALL INTENSITY OF THIS LES. THE FIRST IS THE VERY DRY NATURE OF THE UPSTREAM AIRMASS. INCREASING CHILL WITH H85 TEMPS FCST AS LO AS -23C OVER THE NW HALF OF THE CWA AT 00Z MON WL ALSO CAUSE THE DGZ TO FALL WITHIN ABOUT 1K FT AGL OVER THE W...WHERE MODELS SHOW THE SHARPEST LLVL CNVGC. SHORTER FETCH TO MOISTEN THE LLVLS INTO THE SHARPER CNVGC FCST TO REMAIN OVER ONTONAGON/GOGEBIC COUNTIES...INVRN BASE LINGERING NEAR 5K FT AGL AND THE INCRSGLY POOR SN GROWTH WL ACT TO COUNTER THE SHARPER LLVL CNVGC AND HOLD ACCUMS IN CHECK. FARTHER TO THE E...LLVL NNW WIND THIS MRNG WL FAVOR THE W HALF OF ALGER COUNTY AND ERN MQT COUNTY...BUT ABSENCE OF SHARPER LLVL CNVGC AND SIMILARLY LO INVRN BASE WL OFFSET THE BETTER SN GROWTH THAT WL PERSIST HERE THIS MRNG BEFORE THE ARRIVAL OF COLDER AIR LOWERS THE DGZ A BIT. BY THIS AFTN...THE LLVL FLOW IS ALSO FCST TO BACK SLOWLY TOWARD THE NW...SHIFTING THE LES BANDS AND LIMITING RESIDENCE TIME. DESPITE THESE LIMITING FACTORS...OPTED TO ISSUE AN SPS TO COVER THE SN BANDS OVER ERN MARQUETTE COUNTY THRU THE MRNG AND CONTINUE THE ADVY FOR ALGER THRU THE DAY TO ACCOUNT FOR THE WELL DEFINED LES BANDS AS SHOWN ON RADAR IMAGERY. AS FOR TEMPS...INFLUX OF VERY COLD AIR WL LIMIT ANY DIURNAL TEMP RECOVERY. EXPECT MAX TEMPS OVER W HALF TO HOLD IN THE 5 TO 10F RANGE. INCRSG WINDS TODAY ON THE WRN FLANK OF DEEPENING LO PRES PASSING WELL TO THE E WL CAUSE SOME BLSN AS WELL ESPECIALLY NEAR LK SUP OVER THE E HALF...CLOSER TO THE SFC LO PRES. TNGT...AS THE DEEPER LO PRES EXITS TO THE NE THRU QUEBEC AND SFC HI PRES MOVES TOWARD THE OH RIVER VALLEY...THE LLVL FLOW IS FCST TO BACK STEADILY TOWARD THE W OVER THE WRN CWA AND TO A MORE WNW DIRECTION OVER THE E. HIER RES MODELS INDICATE AN AXIS OF SHARPER LLVL CNVGC WL IMPACT NRN ONTONAGON/CENTRAL HOUGHTON COUNTIES AS WELL AS ERN ALGER/NRN LUCE COUNTIES ALONG A LK INDUCED TROF AND ACCENTUATED BY LAND BREEZE FLOW OUT OF VERY COLD AIRMASS THAT WL MOVE INTO THE WI BORDER COUNTIES...WHERE LK MODERATION OF THE ARCTIC CHILL WL BE ABSENT IN THE MORE W LLVL FLOW AND LO TEMPS WL AT LEAST APRCH -10F. CONCERNED LES ACCUMS OVER THE W IMPACTED BY THE SHARPER LLVL CNVGC MAY AT LEAST APRCH ADVY CRITERIA. BUT SIMILAR NEGATIVES INCLUDING FCST LO INVRN BASE UNDER DEEP LYR QVECTOR DVGC...VERY COLD/DRY AIR AND LO DGZ AS WELL AS THE SHIFTING WINDS LOWER CONFIDENCE FOR ISSUING NEW HEADLINES OVER THE WRN CWA. OVER THE E...NAM FCST SDNGS SHOW MORE SGNFT MOISTENING AND EVEN A LIFTING OF THE INVRN BASE ACCOMPANYING SOME FAIRLY SHARP UVV THAT COINCIDES WITH A HIER DGZ MAINTAINED BY LONGER FETCH ACRS THE WARMING INFLUENCE OF LK SUP. BASED ON THESE CONDITIONS AND POTENTIAL FOR SOME FOCUSED LLVL CNVGC...EXTENDED THE ADVY FOR ALGER COUNTY THRU THE NGT AND ISSUED ONE FOR LUCE COUNTY THAT WL EXTEND INTO MON MRNG. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 352 AM EST SUN JAN 10 2016 AFTER A WARM DECEMBER AND FIRST WEEK OF JANUARY...THE AREA IS TRANSITIONING TO A MORE WINTER LIKE PATTERN TODAY AND THAT IS EXPECTED TO CONTINUE THROUGH THE LONG TERM FORECAST. TEMPERATURES WILL BE BELOW NORMAL THROUGH MUCH OF THE PERIOD (ALTHOUGH SOME MODERATION TOWARDS MORE NORMAL VALUES IS EXPECT BY THE END OF THE WEEK) AND PERIODS OF LAKE EFFECT AND SYNOPTIC SNOW WILL OCCUR INTO NEXT WEEKEND. THIS WEEK/S WEATHER WILL BE DRIVEN BY THE UPPER TROUGH NOW DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY. THE TROUGH WILL MOVE THROUGH THE GREAT LAKES REGION ON MONDAY AND THEN BECOME REINFORCED BY A SECONDARY WAVE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT AS THE FIRST WAVE LIFTS NORTHEAST. THIS WILL KEEP 850MB TEMPS BETWEEN -19C AND -23C FROM MONDAY THROUGH WEDNESDAY. WITH LAKE SUPERIOR TEMPERATURES STILL AROUND 3-4C...THERE WILL BE PLENTY OF OVER THE LAKE INSTABILITY...BUT THE AMOUNT OF COLD AIR WILL KEEP MUCH OF THE CLOUD LAYER ABOVE THE DGZ. THAT WILL LEAD TO SMALLER SNOW FLAKES/RATIOS AND LIMIT THE SNOWFALL AMOUNTS SOME FOR MUCH OF THE WEEK. STARTING ON MONDAY...WINDS WILL BE BACKING QUICKLY TO THE WEST DURING THE MORNING HOURS AS THE SURFACE RIDGE SLIDES ACROSS UPPER MICHIGAN. EXPECT THE LAKE EFFECT TO FOLLOW SUIT AND MOVE OVER THE WESTERLY FAVORED AREAS IN THE MORNING AND THEN SHIFT OFFSHORE OVER THE EAST IN THE AFTERNOON AS THE RIDGE SHIFTS EAST AND WINDS TURN SOUTHWESTERLY AHEAD OF THE APPROACHING SHORTWAVE AND DEVELOPING SURFACE LOW. AS THE SHORTWAVE DIVES JUST TO THE SOUTH OF THE U.P. MONDAY NIGHT...IT WILL STRENGTHEN A LOW OVER CENTRAL LAKE MICHIGAN WITH A INVERTED TROUGH STRETCHING NORTHWEST OVER LAKE SUPERIOR. THE LOW WILL CONTINUE TO STRENGTHEN AS IT MOVES OVER LAKE HURON TUESDAY MORNING...WHILE THE TROUGH DROPS SOUTH OF LAKE SUPERIOR. THAT TROUGH WILL BE THE FOCUS OF AN ENHANCED BAND OF SNOW AIDED BY THE INCREASED CONVERGENCE AND SIGNIFICANTLY RISING INVERSION HEIGHTS (RISING TO 11- 12KFT). EXPECT THE HEAVY SNOW AND GREATLY INCREASING NORTHERLY WINDS TO AFFECT THE WESTERN U.P. AROUND OR SHORTLY AFTER 06Z TUESDAY AND THEN BETWEEN 9-12Z TUESDAY FOR THE NORTH CENTRAL. EXPECT A VERY STRONG BURST OF SNOW FOR A 3-6HR PERIOD ALONG AND RIGHT AFTER THE TROUGH MOVES THROUGH AND THEN MODERATE NORTH- NORTHWEST LAKE EFFECT THROUGH TUESDAY AFTERNOON. ALONG WITH THE HEAVY SNOW...EXPECT A SHARP INCREASE IN THE WINDS OUT OF THE NORTH ALONG THE TROUGH...WITH GUSTS IN THE 25-30KT RANGE. THE COMBINATION OF THE WIND AND SNOW WILL LEAD TO VERY POOR TRAVEL AND VISIBILITIES FOR PORTIONS OF WESTERN AND NORTH CENTRAL UPPER MICHIGAN LATE MONDAY NIGHT INTO TUESDAY MORNING. WITH THE CONSISTENT SIGNAL IN THIS IDEA OVER THE LAST 24-36HRS...WILL BEEF UP THE WORDING IN THE HWO AS SOME AREAS MAY END UP NEEDING WINTER STORM WARNINGS FOR THE COMBINED IMPACTS OF THE SNOW/WIND. AFTER THE LOW AND TROUGH DEPART...A HIGH PRESSURE RIDGE OVER THE UPPER MISSISSIPPI VALLEY WILL SLOWLY NOSE TOWARDS THE AREA AS THE PARENT HIGH SHIFTS INTO THE SOUTHEASTERN STATES. THAT WILL LEAD TO SLOWLY LOWERING INVERSION HEIGHTS THROUGH WEDNESDAY AS WINDS BACK TO THE WEST. WILL SHOW THAT SLOW TRANSITION IN THE POPS AND LESSER SNOWFALL AMOUNTS THROUGH WEDNESDAY NIGHT. THE FORECAST BECOMES UNCERTAIN FOR THE END OF NEXT WEEK AS THE MODELS ARE SHOWING SOME VARIABILITY IN THE EVOLUTION OF THE UPPER TROUGH OFF TO THE EAST OF THE AREA AND WEAK WAVES BRUSHING THE AREA. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE MODELS IN SHOWING TEMPERATURES GRADUALLY WARMING TOWARDS MORE NORMAL VALUES (UPPER TEENS AND LOWER 20S) WITH OCCASIONAL CHANCES FOR SNOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 712 AM EST SUN JAN 10 2016 LES BANDS IMPACTING PRIMARILY IWD AND SAW IN LLVL NNW FLOW WL BRING IFR CONDITIONS TO THOSE SITES THRU AT LEAST THIS MRNG. SAW IS CLOSER TO THE WRN EDGE OF THE LES BANDS...SO CONDITIONS THERE COULD IMPROVE QUICKLY BY LATE MRNG AS THE LLVL FLOW BEGINS TO BACK TOWARD THE NW. ALTHOUGH IWD IS MORE LIKELY TO EXPERIENCE MORE PERSISTENT IFR VSBYS INTO TNGT...A FURTHER BACKING OF THE FLOW ENHANCED BY A LAND BREEZE ACCOMPANYING INFLUX OF VERY COLD AIR INVADING NW WI WL CAUSE IMPROVING CONDITIONS THERE TNGT...WITH VFR WX LIKELY LATE. THIS SLOWLY BACKING FLOW WL CAUSE THE OPPOSITE TREND AT CMX...WITH A MORE FAVORABLE NW THEN WNW FLOW TNGT LEADING TO PREDOMINANT IFR VSBYS BY LATER AFTN AND TNGT. EXPECT PREDOMINAT VFR WX TO DVLP AT SAW BY LATER TNGT WITH THE BACKING DOWNSLOPE FLOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 506 AM EST SUN JAN 10 2016 EXPECT NORTH TO NORTHWEST GALE FORCE GUSTS UP TO 35 KTS INTO THIS EVNG OVER THE E HALF OF LK SUP UNDER A SHARP PRES GRADIENT BTWN A DEEPENING LO PRES MOVING THRU SE CANADA AND HI PRES IN THE PLAINS. THE INFLUX OF VERY COLD AIR ASSOCIATED WITH THESE STRONG WINDS WL RESULT IN SUFFICIENTLY HI WAVES TO GENERATE HEAVY FREEZING SPRAY OVER MUCH OF THE LAKE. AS THE PRES GRADIENT WEAKENS TONIGHT... EXPECT THE GALES AND HEAVY FREEZING SPRAY TO SUBSIDE. THERE MAY BE ANOTHER WIDESPREAD GALE EVENT ON TUE AS A DEEPENING SFC LO PRES PASSING TO THE S TIGHTENS THE GRADIENT AND INCREASES THE N WIND. THERE WL LIKELY BE MORE HEAVY FREEZING SPRAY AS WELL WITH ANOTHER ARCTIC AIR INVASION. WINDS WL DIMINISH ON WED AND THU AS A WEAKER PRES GRADIENT DEVELOPS OVER THE UPPER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST MONDAY FOR MIZ006. LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ005. LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY FOR MIZ007. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM EST MONDAY FOR LSZ267. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ249>251-266-267. HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST MONDAY FOR LSZ264- 266. HEAVY FREEZING SPRAY WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ248>251. HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ244-245. HEAVY FREEZING SPRAY WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ263. HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ242-243. LAKE MICHIGAN... GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ221-248-250. && $$ UPDATE...KC SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 AM EST SUN JAN 10 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 506 AM EST SUN JAN 10 2016 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A DEEP UPR TROF IN CENTRAL NAMERICA DOWNSTREAM OF A HI AMPLITUDE RDG ALONG THE W COAST. A SHRTWV EMBEDDED IN THE ARCTIC BRANCH FLOW IS OVER NW WI AND SUPPORTING AN AREA OF DEEP LYR QVECTOR CNVGC/DEEPER MSTR OVER MAINLY THE E HALF OF THE CWA...WHERE SOME STEADY LIGHT SN IS FALLING UNDER ASSOCIATED COLDER CLD TOPS. SINCE H85 TEMPS HAVE FALLEN UNDER -15C OVER THE E HALF OF LK SUP IN LLVL NNW FLOW AND UNDER THE UPR FORCING...RADAR SHOWS SOME STRONGER LK ENHANCED BANDS ARE MOVING INTO ALGER COUNTY...WHERE THE PREVIOUS SHIFT HAD ISSUED AN LES ADVY...AND ERN MARQUETTE COUNTY. SFC OBS ALSO INDICATE THERE IS SOME LES STREAMING INTO THE WRN CWA TO THE E OF -25C H85 THERMAL TROF STRETCHING FM YPL TO INL...BUT LO INVRN BASE NEAR H9 AS WELL AS SOME DRY LLVL AIR /SFC DEWPTS IN NRN MN ARE AS LO AS -20F/ SHOWN ON THE 00Z INL ROAB ARE LIMITING THE INTENSITY OF THIS PURE LES DESPITE SOME DECENT LLVL CNVGC EVIDENT IN ONTONAGON/GOGEBIC COUNTIES. THERE IS ANOTHER SHRTWV MOVING NEWD THRU THE POLAR BRANCH FLOW FARTHER S IN THE OHIO RIVER VALLEY...SUPPORTING AN AREA OF LO PRES/COLDER CLD TOPS AND WIDESPREAD PCPN THAT IS MOVING INTO LOWER MI. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON LES TRENDS/NEED FOR HEADLINES AND VERY LO TEMPS EXPECTED TNGT AS H85 THERMAL TROF PASSES THRU THE CWA. TODAY...SINCE THE APRCHG ARCTIC BRANCH SHRTWV IS NOT FCST TO PHASE WITH THE POLAR BRANCH DISTURBANCE TO THE S MOVING NEWD...EXPECT WDSPRD LIGHT SN IMPACTING THE ERN CWA EARLY THIS MRNG TO END ARND 12Z SUN AT NEWBERRY AS MUCH DRIER AIR BEGINS TO MOVE E FOLLOWING PASSAGE OF ARCTIC BRANCH SHRTWV TO THE E. BUT INFLUX OF VERY COLD H85 AIR UPSTREAM IN MN WL SUPPORT CONTINUED PURE LES. THERE ARE SEVERAL FACTORS THAT WL LIMIT THE OVERALL INTENSITY OF THIS LES. THE FIRST IS THE VERY DRY NATURE OF THE UPSTREAM AIRMASS. INCREASING CHILL WITH H85 TEMPS FCST AS LO AS -23C OVER THE NW HALF OF THE CWA AT 00Z MON WL ALSO CAUSE THE DGZ TO FALL WITHIN ABOUT 1K FT AGL OVER THE W...WHERE MODELS SHOW THE SHARPEST LLVL CNVGC. SHORTER FETCH TO MOISTEN THE LLVLS INTO THE SHARPER CNVGC FCST TO REMAIN OVER ONTONAGON/GOGEBIC COUNTIES...INVRN BASE LINGERING NEAR 5K FT AGL AND THE INCRSGLY POOR SN GROWTH WL ACT TO COUNTER THE SHARPER LLVL CNVGC AND HOLD ACCUMS IN CHECK. FARTHER TO THE E...LLVL NNW WIND THIS MRNG WL FAVOR THE W HALF OF ALGER COUNTY AND ERN MQT COUNTY...BUT ABSENCE OF SHARPER LLVL CNVGC AND SIMILARLY LO INVRN BASE WL OFFSET THE BETTER SN GROWTH THAT WL PERSIST HERE THIS MRNG BEFORE THE ARRIVAL OF COLDER AIR LOWERS THE DGZ A BIT. BY THIS AFTN...THE LLVL FLOW IS ALSO FCST TO BACK SLOWLY TOWARD THE NW...SHIFTING THE LES BANDS AND LIMITING RESIDENCE TIME. DESPITE THESE LIMITING FACTORS...OPTED TO ISSUE AN SPS TO COVER THE SN BANDS OVER ERN MARQUETTE COUNTY THRU THE MRNG AND CONTINUE THE ADVY FOR ALGER THRU THE DAY TO ACCOUNT FOR THE WELL DEFINED LES BANDS AS SHOWN ON RADAR IMAGERY. AS FOR TEMPS...INFLUX OF VERY COLD AIR WL LIMIT ANY DIURNAL TEMP RECOVERY. EXPECT MAX TEMPS OVER W HALF TO HOLD IN THE 5 TO 10F RANGE. INCRSG WINDS TODAY ON THE WRN FLANK OF DEEPENING LO PRES PASSING WELL TO THE E WL CAUSE SOME BLSN AS WELL ESPECIALLY NEAR LK SUP OVER THE E HALF...CLOSER TO THE SFC LO PRES. TNGT...AS THE DEEPER LO PRES EXITS TO THE NE THRU QUEBEC AND SFC HI PRES MOVES TOWARD THE OH RIVER VALLEY...THE LLVL FLOW IS FCST TO BACK STEADILY TOWARD THE W OVER THE WRN CWA AND TO A MORE WNW DIRECTION OVER THE E. HIER RES MODELS INDICATE AN AXIS OF SHARPER LLVL CNVGC WL IMPACT NRN ONTONAGON/CENTRAL HOUGHTON COUNTIES AS WELL AS ERN ALGER/NRN LUCE COUNTIES ALONG A LK INDUCED TROF AND ACCENTUATED BY LAND BREEZE FLOW OUT OF VERY COLD AIRMASS THAT WL MOVE INTO THE WI BORDER COUNTIES...WHERE LK MODERATION OF THE ARCTIC CHILL WL BE ABSENT IN THE MORE W LLVL FLOW AND LO TEMPS WL AT LEAST APRCH -10F. CONCERNED LES ACCUMS OVER THE W IMPACTED BY THE SHARPER LLVL CNVGC MAY AT LEAST APRCH ADVY CRITERIA. BUT SIMILAR NEGATIVES INCLUDING FCST LO INVRN BASE UNDER DEEP LYR QVECTOR DVGC...VERY COLD/DRY AIR AND LO DGZ AS WELL AS THE SHIFTING WINDS LOWER CONFIDENCE FOR ISSUING NEW HEADLINES OVER THE WRN CWA. OVER THE E...NAM FCST SDNGS SHOW MORE SGNFT MOISTENING AND EVEN A LIFTING OF THE INVRN BASE ACCOMPANYING SOME FAIRLY SHARP UVV THAT COINCIDES WITH A HIER DGZ MAINTAINED BY LONGER FETCH ACRS THE WARMING INFLUENCE OF LK SUP. BASED ON THESE CONDITIONS AND POTENTIAL FOR SOME FOCUSED LLVL CNVGC...EXTENDED THE ADVY FOR ALGER COUNTY THRU THE NGT AND ISSUED ONE FOR LUCE COUNTY THAT WL EXTEND INTO MON MRNG. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 352 AM EST SUN JAN 10 2016 AFTER A WARM DECEMBER AND FIRST WEEK OF JANUARY...THE AREA IS TRANSITIONING TO A MORE WINTER LIKE PATTERN TODAY AND THAT IS EXPECTED TO CONTINUE THROUGH THE LONG TERM FORECAST. TEMPERATURES WILL BE BELOW NORMAL THROUGH MUCH OF THE PERIOD (ALTHOUGH SOME MODERATION TOWARDS MORE NORMAL VALUES IS EXPECT BY THE END OF THE WEEK) AND PERIODS OF LAKE EFFECT AND SYNOPTIC SNOW WILL OCCUR INTO NEXT WEEKEND. THIS WEEK/S WEATHER WILL BE DRIVEN BY THE UPPER TROUGH NOW DROPPING THROUGH THE UPPER MISSISSIPPI VALLEY. THE TROUGH WILL MOVE THROUGH THE GREAT LAKES REGION ON MONDAY AND THEN BECOME REINFORCED BY A SECONDARY WAVE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT AS THE FIRST WAVE LIFTS NORTHEAST. THIS WILL KEEP 850MB TEMPS BETWEEN -19C AND -23C FROM MONDAY THROUGH WEDNESDAY. WITH LAKE SUPERIOR TEMPERATURES STILL AROUND 3-4C...THERE WILL BE PLENTY OF OVER THE LAKE INSTABILITY...BUT THE AMOUNT OF COLD AIR WILL KEEP MUCH OF THE CLOUD LAYER ABOVE THE DGZ. THAT WILL LEAD TO SMALLER SNOW FLAKES/RATIOS AND LIMIT THE SNOWFALL AMOUNTS SOME FOR MUCH OF THE WEEK. STARTING ON MONDAY...WINDS WILL BE BACKING QUICKLY TO THE WEST DURING THE MORNING HOURS AS THE SURFACE RIDGE SLIDES ACROSS UPPER MICHIGAN. EXPECT THE LAKE EFFECT TO FOLLOW SUIT AND MOVE OVER THE WESTERLY FAVORED AREAS IN THE MORNING AND THEN SHIFT OFFSHORE OVER THE EAST IN THE AFTERNOON AS THE RIDGE SHIFTS EAST AND WINDS TURN SOUTHWESTERLY AHEAD OF THE APPROACHING SHORTWAVE AND DEVELOPING SURFACE LOW. AS THE SHORTWAVE DIVES JUST TO THE SOUTH OF THE U.P. MONDAY NIGHT...IT WILL STRENGTHEN A LOW OVER CENTRAL LAKE MICHIGAN WITH A INVERTED TROUGH STRETCHING NORTHWEST OVER LAKE SUPERIOR. THE LOW WILL CONTINUE TO STRENGTHEN AS IT MOVES OVER LAKE HURON TUESDAY MORNING...WHILE THE TROUGH DROPS SOUTH OF LAKE SUPERIOR. THAT TROUGH WILL BE THE FOCUS OF AN ENHANCED BAND OF SNOW AIDED BY THE INCREASED CONVERGENCE AND SIGNIFICANTLY RISING INVERSION HEIGHTS (RISING TO 11- 12KFT). EXPECT THE HEAVY SNOW AND GREATLY INCREASING NORTHERLY WINDS TO AFFECT THE WESTERN U.P. AROUND OR SHORTLY AFTER 06Z TUESDAY AND THEN BETWEEN 9-12Z TUESDAY FOR THE NORTH CENTRAL. EXPECT A VERY STRONG BURST OF SNOW FOR A 3-6HR PERIOD ALONG AND RIGHT AFTER THE TROUGH MOVES THROUGH AND THEN MODERATE NORTH- NORTHWEST LAKE EFFECT THROUGH TUESDAY AFTERNOON. ALONG WITH THE HEAVY SNOW...EXPECT A SHARP INCREASE IN THE WINDS OUT OF THE NORTH ALONG THE TROUGH...WITH GUSTS IN THE 25-30KT RANGE. THE COMBINATION OF THE WIND AND SNOW WILL LEAD TO VERY POOR TRAVEL AND VISIBILITIES FOR PORTIONS OF WESTERN AND NORTH CENTRAL UPPER MICHIGAN LATE MONDAY NIGHT INTO TUESDAY MORNING. WITH THE CONSISTENT SIGNAL IN THIS IDEA OVER THE LAST 24-36HRS...WILL BEEF UP THE WORDING IN THE HWO AS SOME AREAS MAY END UP NEEDING WINTER STORM WARNINGS FOR THE COMBINED IMPACTS OF THE SNOW/WIND. AFTER THE LOW AND TROUGH DEPART...A HIGH PRESSURE RIDGE OVER THE UPPER MISSISSIPPI VALLEY WILL SLOWLY NOSE TOWARDS THE AREA AS THE PARENT HIGH SHIFTS INTO THE SOUTHEASTERN STATES. THAT WILL LEAD TO SLOWLY LOWERING INVERSION HEIGHTS THROUGH WEDNESDAY AS WINDS BACK TO THE WEST. WILL SHOW THAT SLOW TRANSITION IN THE POPS AND LESSER SNOWFALL AMOUNTS THROUGH WEDNESDAY NIGHT. THE FORECAST BECOMES UNCERTAIN FOR THE END OF NEXT WEEK AS THE MODELS ARE SHOWING SOME VARIABILITY IN THE EVOLUTION OF THE UPPER TROUGH OFF TO THE EAST OF THE AREA AND WEAK WAVES BRUSHING THE AREA. THUS...WILL FOLLOW A GENERAL CONSENSUS OF THE MODELS IN SHOWING TEMPERATURES GRADUALLY WARMING TOWARDS MORE NORMAL VALUES (UPPER TEENS AND LOWER 20S) WITH OCCASIONAL CHANCES FOR SNOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1227 AM EST SUN JAN 10 2016 LOOK FOR DETERIORATING CONDITIONS INTO SUNDAY AT THE WRN TAF SITES THROUGH PERIOD AS INCREASINGLY COLDER AIR MOVING ACROSS LAKE SUPERIOR WILL LEAD TO SMALLER LAKE EFFECT SNOWFLAKES AND BE MORE EFFECTIVE AT REDUCING VISIBILITY ESPECIALLY AS NW WINDS PICK UP AND BLOWING SNOW BECOMES MORE OF A FACTOR. WHILE CIGS MAY BE MVFR THROUGH MUCH OF THE PERIOD...SNOW AND BLOWING SNOW WILL EVENTUALLY LEAD TO IFR VSBYS AT BOTH KIWD AND KCMX ESPECIALLY BEGINNING LATE TONIGHT AND PROBABLY CONTINUING INTO SUNDAY. NW WINDS WILL BE GENERALLY LESS FAVORABLE FOR LES TO IMPACT KSAW SO EXPECT PREVAILING MVFR CONDITIONS THERE...EXCEPT FOR MAYBE AN OCCASIONAL PERIOD OF IFR VSBY LATE TONIGHT INTO EARLY SUNDAY WHEN NNW WINDS COULD STILL BE FAVORABLE FOR LES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 506 AM EST SUN JAN 10 2016 EXPECT NORTH TO NORTHWEST GALE FORCE GUSTS UP TO 35 KTS INTO THIS EVNG OVER THE E HALF OF LK SUP UNDER A SHARP PRES GRADIENT BTWN A DEEPENING LO PRES MOVING THRU SE CANADA AND HI PRES IN THE PLAINS. THE INFLUX OF VERY COLD AIR ASSOCIATED WITH THESE STRONG WINDS WL RESULT IN SUFFICIENTLY HI WAVES TO GENERATE HEAVY FREEZING SPRAY OVER MUCH OF THE LAKE. AS THE PRES GRADIENT WEAKENS TONIGHT... EXPECT THE GALES AND HEAVY FREEZING SPRAY TO SUBSIDE. THERE MAY BE ANOTHER WIDESPREAD GALE EVENT ON TUE AS A DEEPENING SFC LO PRES PASSING TO THE S TIGHTENS THE GRADIENT AND INCREASES THE N WIND. THERE WL LIKELY BE MORE HEAVY FREEZING SPRAY AS WELL WITH ANOTHER ARCTIC AIR INVASION. WINDS WL DIMINISH ON WED AND THU AS A WEAKER PRES GRADIENT DEVELOPS OVER THE UPPER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY FOR MIZ007. LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST MONDAY FOR MIZ006. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 1 AM EST MONDAY FOR LSZ267. GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ249>251-266-267. HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST MONDAY FOR LSZ264- 266. HEAVY FREEZING SPRAY WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ263. LAKE MICHIGAN... GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ221-248-250. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1206 AM EST SUN JAN 10 2016 .AVIATION... COLD FRONT CURRENTLY OVER CENTRAL MICHIGAN WILL DROP THROUGH MBS IN THE NEXT FEW HOURS...CHANGING RAIN TO SNOW. THE FRONT WILL THEN SLOWLY WORK SOUTH AND EAST THROUGH THE REST OF THE SOUTHEAST MICHIGAN TERMINALS BETWEEN 09-13Z...CAUSING A CHANGEOVER OF PRECIPITATION TYPE TO SNOW AND A SHARP WIND SHIFT TO THE NORTH- NORTHWEST. WIND GUSTS SO FAR ALONG THE LEADING EDGE OF THE FRONT HAVE BEEN 20 KNOTS OR LESS...BUT EXPECT THESE NUMBERS TO CLIMB OVERNIGHT AS THE FRONT STRENGTHENS IN RESPONSE TO RAPIDLY DEEPENING LOW PRESSURE PASSING THROUGH THE OHIO VALLEY. BY 12Z...EXPECT GUSTS TO STRENGTHEN CLOSER TO 30 KNOTS BY THE TIME IT PASSES THROUGH THE DETROIT AREA TERMINALS. SNOW WILL BECOME HEAVY AT TIMES AT MBS BEFORE 10Z BEFORE VISIBILITIES AND CEILINGS START TO LIFT WITH THE ARRIVAL OF COOLER AIR ALOFT. THE REMAINDER OF THE TERMINALS WILL SEE A MUCH SHORTER WINDOW FOR SNOWFALL AS ELEVATED PORTION OF THE FRONTAL BOUNDARY WILL SPEND LESS TIME OVERHEAD...AND AMOUNTS WILL BE MUCH LIGHTER. LOOKING FOR SNOW TOTALS OF 3-5 INCHES AT MBS...1-2 INCHES AT FNT...AND AN INCH OR LESS ELSEWHERE. WELL-MIXED AND UNSTABLE ENVIRONMENT UP THROUGH 2000 FT AGL WILL ALLOW NORTHWEST WINDS TO STRENGTHEN FURTHER BY LATE MORNING AND CONTINUE INTO THE EVENING. GUSTS AROUND 35 KNOTS ARE EXPECTED BY AFTERNOON. STEADY SNOW WILL TAPER OFF BY 18Z...WITH UNSTABLE AIRMASS AND FLOW OFF LAKE MICHIGAN KEEPING SNOW SHOWERS AROUND THROUGH THE DAY AND SUNDAY NIGHT. FOR DTW...STEADIER RAINFALL AND LIFR CEILINGS SHOULD WORK INTO THE AREA AROUND 09Z. FRONTAL PASSAGE STILL LOOKING TO OCCUR AROUND 12Z...WITH A CHANGEOVER TO SNOW FOLLOWING ONE TO TWO HOURS LATER. WINDOW FOR GOOD SNOWFALL RATES (LESS THAN 1SM) LOOKS SHORT...BETWEEN 14-17Z. SNOW SHOWERS ARE THEN EXPECTED TO CONTINUE THROUGH THE DAY AND INTO THE OVERNIGHT HOURS. POP OF STRONGER WINDS MAY OCCUR WITH THE FRONTAL PASSAGE IN THE MORNING...UP TO 35 KNOTS. LONGER DURATION OF STRONG WINDS NORTHWEST (300-330) WILL THEN DEVELOP DURING THE LATE MORNING AND CONTINUE THROUGH EVENING...GUSTS AROUND 35 KNOTS. //DTW THRESHOLD PROBABILITIES... * HIGH FOR CEILINGS AOB 5000 FEET THROUGH THE TAF PERIOD. * LOW FOR CIGS/VSBYS FALLING BELOW 200FT AND/OR 1/2SM THROUGH MID SUNDAY MORNING. * HIGH FOR PRECIPITATION TYPE AS RAIN THROUGH 11Z SUNDAY MORNING...BECOMING ALL SNOW BY 14Z. * HIGH FOR WIND GUSTS TO REACH 30-35 KNOTS FROM 300-330 BETWEEN 12Z SUN AND 00Z MON. && .PREV DISCUSSION...ISSUED 802 PM EST SAT JAN 9 2016 UPDATE... LOW-LEVEL DRY EASTERLY FLOW IS KEEPING SHOWERS AT BAY OVER EXTREME SOUTHEAST MICHIGAN THIS EVENING...KEEPING AREAS LIKE DETROIT AND ANN ARBOR DRY WHILE AN AREA OF RAIN LIFTS OVER THE WESTERN HALF OF THE STATE AND INTO THE SAGINAW VALLEY AND THUMB. FORECAST UPDATE WAS MOSTLY TO ADJUST EVENING POPS TO COVER CURRENT TRENDS...MAINLY INCREASING POPS WEST OF FLINT. AT 8PM...COLD FRONT WAS STRETCHED FROM HOUGHTON LAKE TO BIG RAPIDS. THE FRONT WILL SLOWLY WORK SOUTH AND EAST LATE THIS EVENING AND OVERNIGHT...BRINGING A CHANGEOVER IN PRECIPITATION TYPE TO SNOW. CURRENT FORECAST LOOKS ON TRACK...WITH CHANGEOVER IN THE SAGINAW VALLEY OCCURRING IN THE 3-6Z TIMEFRAME. PREV DISCUSSION...ISSUED 320 PM EST SAT JAN 9 2016 PER RECENT WATER VAPOR IMAGERY...THE MAIN UPPER WAVE IS SHOWN LIFTING INTO ARKANSAS WHILE A SHORTER WAVELENGTH IMPULSE IS NOW LIFTING INTO CENTRAL ILLINOIS. MEANWHILE...THERE IS ONGOING AMPLIFICATION IN THE BASE OF THE CENTRAL CANADIAN POLAR LOW INTO THE UPPER MIDWEST. THIS HAS BEEN DRIVING AN ARCTIC BOUNDARY SOUTHWARD ACROSS THE MID MS VALLEY. SFC LOW PRESSURE NOW LOCATED ALONG THE AR/TN BORDER REGION WILL LIFT NORTHEAST INTO OHIO TONIGHT AS THE MID LEVEL WAVE ROTATES INTO THE UPPER OHIO VALLEY. THIS WILL SLOW THE EASTWARD PROGRESS OF THE ARCTIC FRONT ACROSS LOWER MI TONIGHT. DEEP LAYER MOISTURE ADVECTION AND LARGER SCALE ASCENT ASSOCIATED WITH THESE UPSTREAM SHORT WAVE FEATURES HAVE BEEN RESULTING IN A NORTHWARD EXPANSION OF RAIN ACROSS INDIANA AND NE ILLINOIS THIS AFTERNOON. ACROSS CENTRAL EAST CENTRAL IL AND DEEPER INTO THE COLD AIR...THE PRECIP HAS BEEN IN THE FORM OF SNOW. RECENT HI RES SOLUTIONS WITH SUPPORT OF UPSTREAM RADAR/SATELLITE SUGGEST THE PRECIP WILL FIRST ARRIVE INTO SRN MI ALONG THE MID LEVEL FRONT WHICH NOW EXTENDS FROM SRN MO INTO CNTL LOWER MI. THIS WILL CAUSE RAIN TO OVERSPREAD THE WESTERN SECTIONS OF THE FCST AREA AND SAGINAW VALLEY THIS EVENING. THE APPROACH OF THE UPPER WAVE TONIGHT WILL CAUSE A TIGHTENING OF THE THERMAL GRADIENT ALONG THE FRONTAL SLOPE...LEADING TO AN INTENSIFICATION IN THE MID LEVEL FRONTOGENESIS. THIS ALONG WITH SOME DYNAMIC COOLING WILL LEAD TO A SHARP TRANSITION ZONE BETWEEN RAIN AND HEAVY WET SNOW. THE RECENT HRRR WITH SUPPORT OF UPSTREAM OBS CONTINUES TO SUGGEST THIS TRANSITION ZONE WILL BE OVER MIDLAND/BAY COUNTIES LATE THIS EVENING. THE RAIN/SNOW LINE WILL THEN SLOWLY PUSH SOUTHEAST ACROSS THE SAGINAW VALLEY OVERNIGHT. THE REST OF THE FORECAST AREA WILL SEE LIGHT RAIN OR DRIZZLE DURING THIS TIME PERIOD. THE 12Z MODEL SOLUTIONS ACTUALLY SUGGESTS THE BETTER MID LEVEL DEFORMATION TRANSITIONING ACROSS THE REMAINDER OF THE FORECAST AREA RATHER QUICKLY LATE TONIGHT INTO SUN MORNING AS THE UPPER WAVE LIFTS ACROSS THE UPPER OHIO VALLEY. THE SURFACE LOW WILL IN TURN DEEPEN AS IT LIFTS FROM NORTHERN OHIO INTO SRN ONTARIO SUN MORNING. THIS WILL PROPEL THE ARCTIC FRONT ACROSS THE REST OF THE FORECAST AREA...TRANSITIONING RAIN OVER TO SNOW. THE HEADLINES WILL REMAIN UNCHANGED. THE POTENTIAL LONG DURATION /03Z TO 09Z/ OF MODERATE TO HEAVY SNOW STILL SUGGESTS A GOOD CHANCE OF GETTING SNOW AMOUNTS OVER 6 INCHES ACROSS MIDLAND/NRN BAY. THE LATER CHANGE OVER ACROSS THE ADVISORY AREA /SAGINAW/SHIAWASSEE/TUSCOLA/HURON SUGGESTS 1 TO 4 INCH TYPE ACCUMS. THE REST OF THE FORECAST AREA WILL CHANGE OVER TO SNOW AROUND THE TIME THAT THE LARGE SCALE FORCING IS WEAKENING...SO AMOUNTS WILL BE MUCH LESS. THE ARCTIC FRONT /FORECAST TO PUSH FROM THE SAGINAW VALLEY AND THUMB AT 09Z ACROSS METRO DETROIT AND PORT HURON BY 12 TO 13Z/ WILL BE MARKED AN INCREASE IN WIND GUSTS AND RAPID DROP IN TEMPS /INTO THE MID 20S/. THIS COULD CAUSE SOME RAPID FREEZING OF WET/SNOW COVERED ROADWAYS /ESPECIALLY IN THE ADVISORY AND WARNING COUNTIES/. THE NEGATIVE TILT OF THE MID LEVEL SHORT WAVE LIFTING ACROSS THE UPPER OHIO VALLEY SUN AND VERY STRONG BAROCLINICITY WILL LEAD TO A RAPIDLY DEEPENING SURFACE LOW TRACKING ACROSS ONTARIO SUNDAY /FCST TO DROP TO 982MB BY SUN EVENING/. THIS WILL INCREASE THE NORTHWEST GRADIENT ACROSS SE MI. AS THE DEPTH OF THE COLD AIR INCREASES DURING SUN AFTERNOON...WINDS WILL INCREASE /GUSTING UP TO 35 AND 40 MPH AT TIMES/. TEMPS WILL ALSO CONTINUE TO DROP UNDER THE STEADY INFILTRATION OF ARCTIC AIR...WITH WIND CHILLS DROPPING TOWARD ZERO BY LATE SUN AFTERNOON. MAIN FOCUS FOR THE REST OF THE FORECAST IS ON THE CLIPPER SYSTEM THAT IS EXPECTED TO BRING ACCUMULATING SNOW TO THE AREA MONDAY NIGHT AND TUESDAY. THE UPPER WAVE ASSOCIATED WITH THIS DISTURBANCE IS EXPECTED TO RACE SOUTH-SOUTHEASTWARD ALONG THE WESTERN PERIPHERY OF THE UPPER LOW OVER WESTERN HUDSON BAY...WITH THE SHEARED-OUT VORT MAX QUICKLY BECOMING MORE CIRCULAR DIRECTLY OVER THE WESTERN GREAT LAKES. THIS PROCESS IS EXPECTED TO LEAD TO RAPID CYCLOGENESIS OVER MID-MICHIGAN/LAKE HURON MONDAY NIGHT INTO TUESDAY. NWP CONTINUES TO BE IN GOOD AGREEMENT WITH THE EVOLUTION OF THESE FEATURES. GFS/ECMWF/NAM ALL STRENGTHEN THE SURFACE LOW 8-12 MB IN 12 HR FROM 06-18Z TUESDAY. THE FIRST PHASE OF THIS EVENT APPEARS TO BE A RELATIVELY UNIFORM DISTRIBUTION OF LIGHT SNOW MONDAY NIGHT...FORCED BY ISENTROPIC LIFT INITIALLY AND THEN WITH A CONTRIBUTION FROM DCVA AS THE UPPER WAVE APPROACHES. THE PASSAGE OF A STRONG COLD FRONT AROUND 12Z TUESDAY WILL LIKELY RESULT IN THE TRANSITION TO MORE OF A LAKE EFFECT EVENT. A QUICK LOOK AT SOME OF THE LAKE EFFECT PARAMETERS SUGGESTS THE POTENTIAL FOR SNOW SQUALLS EXTENDING INTO SOUTHEAST MICHIGAN. H850 TEMPS DROP TO NEAR -17C WITH 0-1KM THETA-E LAPSE RATES DOWN TO -6 K/KM OVER LAKE MICHIGAN. MEANWHILE TEMPS WILL BE DROPPING INTO THE TEENS WITH SUSTAINED WINDS APPROACHING 20 MPH...WHICH MAY RESULT IN WIND CHILLS INTO THE SINGLE DIGITS. ALL TOLD...EARLY INDICATIONS ARE FOR 2 TO 4 INCHES WITH LOCALES THAT SEE MORE IN THE WAY OF LAKE EFFECT TUESDAY TOWARD THE HIGHER END OF THAT RANGE. TEMPERATURES WILL REMAIN ON THE CHILLY SIDE WITH PERHAPS A MODERATING TREND TOWARD THE END OF THE WEEK AS THE HUDSON BAY UPPER LOW DRIFTS A BIT NORTH AND EAST INTO QUEBEC. DISTURBANCES ROTATING AROUND THE UPPER LOW WILL PROVIDE A FEW MORE CHANCES FOR LIGHT SNOW FROM THE MIDDLE TO THE END OF NEXT WEEK. MARINE... MILD AIR AND LIGHT WINDS AROUND EARLY THIS EVENING WILL ABRUPTLY CHANGE LATE TONIGHT AS A RAPIDLY DEEPENING LOW PRESSURE SYSTEM TRACKS NORTHEAST THROUGH THE EASTERN GREAT LAKES. STRONG NORTHWEST GALES WILL DEVELOP IN THE LOWS WAKE TOMORROW MORNING...AS ARCTIC AIR SURGES INTO THE AREA. WITH THE GALES AND PLUMMETING TEMPERATURES...A HEAVY FREEZING SPRAY WARNING IS IN EFFECT FOR SUNDAY AFTERNOON. WINDS WILL DIMINISH AND BACK TO WESTERLY BY MONDAY MORNING BUT WILL REMAIN ELEVATED IN THE 20 TO 30 KNOT RANGE. A SECOND SURGE OF ARCTIC AIR IS EXPECTED ON TUESDAY...WHICH LOOKS TO SUPPORT ANOTHER PERIOD OF STRONG NORTHWEST GALES AND HEAVY FREEZING SPRAY OVER THE OPEN WATERS OF LAKE HURON. A GALE WATCH WAS NOT ISSUED DUE TO CURRENT HEADLINE IN EFFECT. HYDROLOGY... DEEPENING LOW PRESSURE WILL TRACK THROUGH THE EASTERN GREAT LAKES TONIGHT...SPREADING A GOOD SLUG OF MOISTURE INTO THE REGION. PRECIPITATION WILL START OFF AS RAIN THIS EVENING BEFORE COLD AIR SURGES IN FROM THE NORTH...QUICKLY CHANGING IT OVER TO SNOW BY SUNDAY MORNING. HIGHEST SNOWFALL AMOUNTS WILL OCCUR ACROSS THE SAGINAW VALLEY AREA...TAPERING OFF HEADING SOUTHWARD. TOTAL PRECIPITATION AMOUNTS ARE EXPECTED TO RANGE FROM THREE QUARTERS OF AN INCH ACROSS TRI-CITIES REGION TAPERING OFF SOUTHEAST TO A QUARTER OF AN INCH IN AND AROUND DETROIT. TEMPERATURES PLUMMETING INTO THE TEENS SUNDAY EVENING WILL FREEZE ANY LEFTOVER STANDING WATER. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING UNTIL NOON EST TODAY FOR MIZ047-048. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ049- 054. WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MIZ053-060. LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY FOR LHZ462>464. GALE WARNING FROM 4 AM EARLY THIS MORNING TO 6 AM EST MONDAY FOR LHZ361>363-462>464. GALE WARNING FROM 4 AM EARLY THIS MORNING TO 11 PM EST THIS EVENING FOR LHZ421-422-441>443. HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR LHZ361>363. LAKE ST CLAIR...GALE WARNING FROM 7 AM THIS MORNING TO 11 PM EST THIS EVENING FOR LCZ460. MICHIGAN WATERS OF LAKE ERIE...GALE WARNING FROM 7 AM THIS MORNING TO 11 PM EST THIS EVENING FOR LEZ444. && $$ AVIATION.....HLO UPDATE.......HLO DISCUSSION...SC/DT MARINE.......SF HYDROLOGY....SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
551 PM CST MON JAN 11 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 300 PM CST MON JAN 11 2016 LIGHT SNOW AT MID AFTERNOON PUSHING INTO CENTRAL MINNESOTA WILL ADVANCE QUICKLY EAST-SOUTHEAST THROUGH THIS EVENING AS A WAVE OF LOW PRESSURE MOVES ALONG THE ARCTIC FRONT. MUCH OF THE ACCUMULATING SNOW (AROUND AN INCH) REMAINS FOCUSED ALONG AND NORTH OF I-94 WITH AMOUNTS DWINDLING TO A FEW TENTHS ONCE YOU REACH THE MINNESOTA RIVER VALLEY. A CONCERN GOING FORWARD THROUGH THE EVENING IS THE AMOUNT OF BLOWING SNOW THAT WILL OCCUR ACROSS WEST CENTRAL MINNESOTA AS STRONG PRESSURE RISES FOLLOW THE ARCTIC WAVE. RAP PROFILE DATA AT KMOX IS A LITTLE DISCONCERTING. THE PROFILE THROUGH THE EVENING IS SATURATED FROM THE SFC-700MB IN THE DENDRITIC GROWTH ZONE WHILE THE WIND PROFILE SHOWS 25 KNOTS JUST OFF THE SURFACE WITH 33 KNOTS AT THE TOP OF THE CHANNEL. OUR NEIGHBORS TO THE WEST WERE NOT TOO CONCERNED DUE TO THE LACK OF SNOW ACCUMULATION EXPECTED BEFORE THE STRONG WINDS ARRIVE. THEREFORE...NO ADVISORIES PLANNED AT THIS TIME BUT THIS WILL NEED TO BE WATCHED. ON OUR END...INDICATED AREAS OF BLOWING SNOW INTO THE EARLY MORNING HOURS OF TUESDAY. KEPT LOWS TONIGHT AND HIGHS TUESDAY ON THE COLD SIDE BASED ON RECENT VERIFICATION. THIS RESULTS IN ALL SITES BETWEEN 5 AND 10 DEGREES BELOW ZERO TONIGHT WITH HIGHS TUESDAY FROM ZERO TO 5 ABOVE. THE WIND CHILL ADVISORY ISSUED EARLIER TODAY FOR THE FA LOOKS GREAT GIVEN THE EXPECTED TEMPERATURES AND WIND SPEEDS TONIGHT AND EARLY TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 PM CST MON JAN 11 2016 THE BEST WAY TO SUM UP THE NEXT SEVERAL DAYS WOULD BE COLD WITH OCCASIONAL SNOW SHOWERS. A FAIRLY SIGNIFICANT WINTER STORM WILL DEVELOP ACROSS THE MIDWEST ON FRIDAY/SATURDAY...BUT AT THIS TIME IS APPEARS THE MAJORITY OF THE ACCUMULATING SNOW WILL FALL SOUTHEAST OF THE FORECAST AREA. AT THE START OF THE PERIOD TUESDAY NIGHT NORTHWEST FLOW WILL BE IN PLACE...WITH SLIGHT H850 WARM AIR ADVECTION. A NORTHWEST/SOUTHEAST TEMPERATURE GRADIENT WILL LAY OUT ACROSS THE REGION...AND THIS WILL BE THE FOCUS FOR A BAND OF LIGHT SNOW THAT WILL DEVELOP ON WEDNESDAY MAINLY ALONG AND NORTH OF I-94. THIS BAND OF SNOW WILL SLOWLY SHIFT EASTWARD THURSDAY NIGHT. MEANWHILE AND UPPER LEVEL WAVE WILL MOVE FROM THE TEXAS PANHANDLE UP TOWARDS THE OHIO RIVER VALLEY. AS IT DOES SO...A SURFACE LOW PRESSURE SYSTEM WILL DEVELOP ACCOMPANIED BY A BAND OF HEAVY SNOW ON THE COLD SIDE OF THE PRECIPITATION SHIELD. THERE IS STILL A CONSIDERABLE AMOUNT OF UNCERTAINTY WITH THIS SYSTEM SINCE THE EXACT TRACK DEPENDS ON THE INTERACTION OF BOTH THE NORTHERN AND SOUTHERN JET STREAMS. FOR THIS REASON...DID NOT INCREASE POPS ABOVE THE BLENDED MODEL GUIDANCE. IT STILL LOOKS LIKE THE BEST CHANCE FOR A FEW INCHES OF ACCUMULATING SNOW WOULD BE FROM ALBERT LEA UP THROUGH EAU CLAIRE WI. LOOKING AHEAD...ANOTHER BLAST OF ARCTIC AIR WILL ARRIVE IN THE WAKE OF THIS STORM...WITH TEMPERATURES FALLING BACK BELOW ZERO EARLY NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 544 PM CST MON JAN 11 2016 LIGHT SNOW IS PUSHING ACROSS EASTERN MN AND WESTERN WI THIS EVENING. THE SNOW IS MOVING QUICKLY SO THE IFR VISIBILITY IS TYPICALLY ONLY LASTING FOR A COUPLE HOURS...AND ALL TOGETHER THE SNOW IS LINGERING ABOUT 3-5 HOURS. THE MVFR CEILINGS/VIS WILL HOLD ON FOR A WHILE...BUT WE SHOULD SEE GRADUALLY IMPROVEMENT LATE THIS EVENING AND TONIGHT. THE EXCEPTION MIGHT BE AT KRWF AND KAXN...WHICH COULD SEE MVFR VISIBILITY RETURN IF THE BLOWING SNOW KICKS UP WHEN THE WIND ARRIVES THIS EVENING. TOMORROW WILL BE VFR. KMSP... THE WORST OF THE SNOW IS NOW EAST OF THE AIRPORT...AND THE CEILINGS AND VISIBILITY SHOULD CONTINUE TO IMPROVE OVER THE NEXT 1-2 HOURS. KMSP COULD BE VFR BY 01Z IF THE TREND CONTINUES. BOTH THE CEILING AND VISIBILITY ARE SHOWING QUICK IMPROVEMENT. A FEW FLURRIES COULD MOVE IN TONIGHT...BUT NOT TOO CONCERNED ABOUT THIS AT THE MOMENT. WE THINK THE TUESDAY MORNING COMMUTE WILL BE FINE. /OUTLOOK FOR KMSP/ WED...VFR. WINDS SW 5-10 KTS. THU...VFR. WINDS SE 5-10 KTS. FRI...VFR. MVFR/-SN POSSIBLE. WINDS N 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST TUESDAY FOR WIZ014>016- 023>028. MN...WIND CHILL ADVISORY FROM 3 AM TO NOON CST TUESDAY FOR MNZ053- 060>063-067>070-073>078-082>085-091>093. WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY FOR MNZ041>045-047>052-054>059-064>066. && $$ SHORT TERM...RAH LONG TERM...JRB AVIATION...CLF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1149 AM CST SUN JAN 10 2016 .SYNOPSIS... ISSUED AT 3 AM CST SUN JAN 10 2016 THE UA PATTERN ACROSS NOAM TONIGHT REMAINS FAIRLY STAGNANT COMPARED TO 24 HRS AGO. CLOSED LOW PRESSURE WAS CENTERED OVER WESTERN PORTIONS OF THE HUDSON BAY OF CANADA. SOUTH OF THIS LOW...A TROUGH EXTENDED SOUTH INTO THE OZARKS AND CENTRAL GULF COAST STATES. EAST OF THIS FEATURE...RIDGING WAS PRESENT ACROSS THE CANADIAN MARITIMES INTO LABRADOR NEWFOUNDLAND AND NORTH TO SRN GREENLAND. WEST OF THE TROUGH...A RIDGE OF HIGH PRESSURE EXTENDED FROM OFF THE WEST COAST OF OREGON...NORTH INTO THE YUKON. AT THE SURFACE...COLD ARCTIC HIGH PRESSURE HAS PUSHED INTO EASTERN NEBRASKA OVERNIGHT AND AS OF 2 AM CST...WAS ROUGHLY CENTERED NEAR YORK NEBRASKA. COLD TEMPERATURES WERE PRESENT ACROSS THE FORECAST AREA WITH READINGS GENERALLY ZERO TO 10 BELOW ZERO. THE EXCEPTION WAS OVER PORTIONS OF NORTH CENTRAL NEBRASKA ALONG A CORRIDOR FROM EAST OF VALENTINE TO EAST OF BROKEN BOW WHERE CLOUDS WERE PRESENT. ANOTHER AREA OF "WARMER" TEMPERATURES WAS LOCATED IN THE EASTERN NEBRASKA PANHANDLE AND FAR SWRN NEBRASKA...WHERE A MID LEVEL DECK OF CLOUDS WAS PRESENT INVOF A MID LEVEL FRONTAL BOUNDARY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 3 AM CST SUN JAN 10 2016 PATCHY FOG ON THE WESTERN PERIPHERY OF THE MID LEVEL CLOUD DECK SHOULD TRACK SLOWLY EAST THROUGH MID MORNING AS THE MID LEVEL DECK TRANSITIONS EAST AS WELL. BOTH THE NAM AND HRRR HAVE SOME SUPPORT FOR FOG DEVELOPMENT IN THE FAR SWRN CWA THIS MORNING AND HAVE INSERTED IN A MENTION OF PATCHY FOG THROUGH 15Z THIS MORNING. FLURRIES WERE TAKEN OUT OF THE FORECAST FOR THIS MORNING...AS LIFT IN THE DENDRITIC LAYER HAS TRENDED MUCH WEAKER WITH THE PAST EVENINGS MODEL RUNS. ALSO...OBS ACROSS THE PANHANDLE AND FAR SWRN NEBRASKA HAVE BEEN SNOW FREE TONIGHT. AS FOR TEMPERATURES TODAY...HIGH PRESSURE WILL SLIDE SOUTH SOUTHEAST INTO EASTERN KANSAS...WHICH WILL ALLOW WARMER AIR ACROSS THE HIGH PLAINS...TO TRACK EAST INTO WESTERN AND CENTRAL NEBRASKA THIS AFTERNOON. BY 21Z THIS AFTERNOON...H85 TEMPS ACTUALLY REACH -2 TO -3C IN FAR SWRN NEBRASKA. WITH MIXING THIS WOULD FACILITATE HIGHS IN THE UPPER 30S TO AROUND 40. HOWEVER...WINDS WILL BE FAIRLY LIGHT THIS AFTERNOON...AND WE WILL BE BATTLING A MID LEVEL DECK OF CLOUDS...AT LEAST THROUGH THE FIRST HALF OF THE DAY...SO HAVE LIMITED HIGHS TO THE MIDDLE 30S IN THE SWRN CWA THIS AFTERNOON. ELSEWHERE...HIGHS WILL GENERALLY BE IN THE 20S WITH COOLEST READINGS IN THE FAR NORTHEASTERN CWA. FOR TONIGHT...A WEAK REINFORCING SHOT OF ARCTIC AIR WILL ATTEMPT TO PUSH INTO THE FAR NORTHEASTERN CWA TONIGHT WITH THE BULK OF THIS SECONDARY SURGE OF ARCTIC AIR REMAINING EAST OF THE FORECAST AREA. FURTHER WEST ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...OVERNIGHT LOWS WILL BE IN THE TEENS AND ARE EXPECTED TO BE HIT DURING THE LATE EVENING/EARLY OVERNIGHT HOURS AS A SHIELD OF MID LEVEL CLOUDS PUSH INTO THE FORECAST AREA FROM SOUTH DAKOTA OVERNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 3 AM CST SUN JAN 10 2016 A SURFACE FRONT WILL OSCILLATE THROUGH NEBRASKA THROUGH MOST OF THE WEEK. HOWEVER...THERE IS NOT EXPECTED TO BE A CONNECTION TO A SOURCE OF SIGNIFICANT MOISTURE. THEREFORE...THE PROBABILITIES OF PRECIPITATION WITH EACH OSCILLATION WILL BE LOW. A WARM FRONT WILL BRING HIGHER TEMPERATURES TO CENTRAL AND WESTERN NEBRASKA MONDAY. FRONT RETURNS FROM THE NORTHEAST INTO NORTH CENTRAL AND NORTHEAST NEBRASKA MONDAY NIGHT AND WILL BRING COLDER TEMPERATURES AND A POSSIBILITY OF LIGHT SNOW TO THOSE AREAS. THE FRONT WILL THEN RETURN TO THE NORTH AND EAST WEDNESDAY BRINGING A RETURN OF SLIGHTLY HIGHER TEMPERATURES. FAIRLY QUIET WEATHER IS THEN EXPECTED UNTIL ANOTHER FRONT COMES THROUGH FRIDAY AND BRINGS THE POSSIBILITY OF LIGHT SNOW ONCE MORE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1149 AM CST SUN JAN 10 2016 VFR CONDITIONS AND LIGHT WESTERLY TO NORTHERLY WINDS ARE ANTICIPATED ACROSS WEST CENTRAL NEBRASKA THROUGH MUCH OF THE 18Z FORECAST PERIOD...ALTHOUGH AN UPPER LEVEL DISTURBANCE WILL INCREASE LOW STRATUS LATE IN THE FORECAST PERIOD...ESPECIALLY AT KVTN. IN ADDITION...LIGHT SNOW OR FLURRIES MAY BE POSSIBLE ACROSS NORTHERN NEBRASKA. AT THIS TIME THE PROSPECTS OF PRECIPITATION ARE LOW ENOUGH TO NOT WARRANT A MENTION IN THE OFFICIAL FORECAST...BUT WILL CONTINUE TO MONITOR. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...SPRINGER AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
559 AM CST SUN JAN 10 2016 .SYNOPSIS... ISSUED AT 3 AM CST SUN JAN 10 2016 THE UA PATTERN ACROSS NOAM TONIGHT REMAINS FAIRLY STAGNANT COMPARED TO 24 HRS AGO. CLOSED LOW PRESSURE WAS CENTERED OVER WESTERN PORTIONS OF THE HUDSON BAY OF CANADA. SOUTH OF THIS LOW...A TROUGH EXTENDED SOUTH INTO THE OZARKS AND CENTRAL GULF COAST STATES. EAST OF THIS FEATURE...RIDGING WAS PRESENT ACROSS THE CANADIAN MARITIMES INTO LABRADOR NEWFOUNDLAND AND NORTH TO SRN GREENLAND. WEST OF THE TROUGH...A RIDGE OF HIGH PRESSURE EXTENDED FROM OFF THE WEST COAST OF OREGON...NORTH INTO THE YUKON. AT THE SURFACE...COLD ARCTIC HIGH PRESSURE HAS PUSHED INTO EASTERN NEBRASKA OVERNIGHT AND AS OF 2 AM CST...WAS ROUGHLY CENTERED NEAR YORK NEBRASKA. COLD TEMPERATURES WERE PRESENT ACROSS THE FORECAST AREA WITH READINGS GENERALLY ZERO TO 10 BELOW ZERO. THE EXCEPTION WAS OVER PORTIONS OF NORTH CENTRAL NEBRASKA ALONG A CORRIDOR FROM EAST OF VALENTINE TO EAST OF BROKEN BOW WHERE CLOUDS WERE PRESENT. ANOTHER AREA OF "WARMER" TEMPERATURES WAS LOCATED IN THE EASTERN NEBRASKA PANHANDLE AND FAR SWRN NEBRASKA...WHERE A MID LEVEL DECK OF CLOUDS WAS PRESENT INVOF A MID LEVEL FRONTAL BOUNDARY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 3 AM CST SUN JAN 10 2016 PATCHY FOG ON THE WESTERN PERIPHERY OF THE MID LEVEL CLOUD DECK SHOULD TRACK SLOWLY EAST THROUGH MID MORNING AS THE MID LEVEL DECK TRANSITIONS EAST AS WELL. BOTH THE NAM AND HRRR HAVE SOME SUPPORT FOR FOG DEVELOPMENT IN THE FAR SWRN CWA THIS MORNING AND HAVE INSERTED IN A MENTION OF PATCHY FOG THROUGH 15Z THIS MORNING. FLURRIES WERE TAKEN OUT OF THE FORECAST FOR THIS MORNING...AS LIFT IN THE DENDRITIC LAYER HAS TRENDED MUCH WEAKER WITH THE PAST EVENINGS MODEL RUNS. ALSO...OBS ACROSS THE PANHANDLE AND FAR SWRN NEBRASKA HAVE BEEN SNOW FREE TONIGHT. AS FOR TEMPERATURES TODAY...HIGH PRESSURE WILL SLIDE SOUTH SOUTHEAST INTO EASTERN KANSAS...WHICH WILL ALLOW WARMER AIR ACROSS THE HIGH PLAINS...TO TRACK EAST INTO WESTERN AND CENTRAL NEBRASKA THIS AFTERNOON. BY 21Z THIS AFTERNOON...H85 TEMPS ACTUALLY REACH -2 TO -3C IN FAR SWRN NEBRASKA. WITH MIXING THIS WOULD FACILITATE HIGHS IN THE UPPER 30S TO AROUND 40. HOWEVER...WINDS WILL BE FAIRLY LIGHT THIS AFTERNOON...AND WE WILL BE BATTLING A MID LEVEL DECK OF CLOUDS...AT LEAST THROUGH THE FIRST HALF OF THE DAY...SO HAVE LIMITED HIGHS TO THE MIDDLE 30S IN THE SWRN CWA THIS AFTERNOON. ELSEWHERE...HIGHS WILL GENERALLY BE IN THE 20S WITH COOLEST READINGS IN THE FAR NORTHEASTERN CWA. FOR TONIGHT...A WEAK REINFORCING SHOT OF ARCTIC AIR WILL ATTEMPT TO PUSH INTO THE FAR NORTHEASTERN CWA TONIGHT WITH THE BULK OF THIS SECONDARY SURGE OF ARCTIC AIR REMAINING EAST OF THE FORECAST AREA. FURTHER WEST ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...OVERNIGHT LOWS WILL BE IN THE TEENS AND ARE EXPECTED TO BE HIT DURING THE LATE EVENING/EARLY OVERNIGHT HOURS AS A SHIELD OF MID LEVEL CLOUDS PUSH INTO THE FORECAST AREA FROM SOUTH DAKOTA OVERNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 3 AM CST SUN JAN 10 2016 A SURFACE FRONT WILL OSCILLATE THROUGH NEBRASKA THROUGH MOST OF THE WEEK. HOWEVER...THERE IS NOT EXPECTED TO BE A CONNECTION TO A SOURCE OF SIGNIFICANT MOISTURE. THEREFORE...THE PROBABILITIES OF PRECIPITATION WITH EACH OSCILLATION WILL BE LOW. A WARM FRONT WILL BRING HIGHER TEMPERATURES TO CENTRAL AND WESTERN NEBRASKA MONDAY. FRONT RETURNS FROM THE NORTHEAST INTO NORTH CENTRAL AND NORTHEAST NEBRASKA MONDAY NIGHT AND WILL BRING COLDER TEMPERATURES AND A POSSIBILITY OF LIGHT SNOW TO THOSE AREAS. THE FRONT WILL THEN RETURN TO THE NORTH AND EAST WEDNESDAY BRINGING A RETURN OF SLIGHTLY HIGHER TEMPERATURES. FAIRLY QUIET WEATHER IS THEN EXPECTED UNTIL ANOTHER FRONT COMES THROUGH FRIDAY AND BRINGS THE POSSIBILITY OF LIGHT SNOW ONCE MORE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 558 AM CST SUN JAN 10 2016 FOR THE KLBF TERMINAL...EXPECT BROKEN CIGS OF 8000 FT AGL THIS MORNING WITH CLEARING SKIES BY MIDDAY. FOR TONIGHT...HIGH AND MID LEVEL CLOUDINESS WILL INCREASE WITH BROKEN CIGS OF 10000 TO 20000 FT AGL. FOR THE KVTN TERMINAL...EXPECT CLEAR SKIES TODAY WITH INCREASING MID AND HIGH CLOUDS LATER THIS AFTERNOON. CIGS WILL RANGE FROM 10000 TO 20000 FT AGL. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...SPRINGER AVIATION...BUTTLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
542 AM CST SUN JAN 10 2016 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 315 AM CST SUN JAN 10 2016 WIND CHILLS THIS MORNING...TEMPERATURES THROUGH THE PERIOD AND A FEW CHANCES FOR LIGHT SNOW BE THE MAIN FORECAST CONCERNS. COLD HIGH PRESSURE HAD SETTLED SOUTHWARD THE PAST 24 HOURS AND AT 09Z STRETCHED FROM ND TO TX. THIS WILL SLIDE OFF TO THE SOUTHEAST WHILE LOW PRESSURE OVER NERN WY PUSHES EAST ACROSS SD TODAY. WINDS WILL TURN TO THE SOUTHWEST...ALLOWING WARMER AIR TO START TO MOVE INTO THE AREA. WILL KEEP THE WIND CHILL ADVISORY GOING THIS MORNING. WE COULD SEE A FEW FLURRIES IN NERN NE AS PATCH OF LOW CLOUDS TO THE WEST TRIES TO MOVE EAST. HIGHS THIS AFTERNOON WILL BE MAINLY IN THE TEENS...WITH PERHAPS A FEW LOWER 20S IN OUR SRN AND WRN COUNTIES. LOWS TONIGHT SHOULD NOT BE AS COLD...WITH A LOW LEVEL WARM AIR ADVECTION PATTERN IN PLACE. HIGHS MONDAY SHOULD REACH THE 30S AT MOST LOCATIONS IN ERN NE...WITH MID 20S TO LOWER 30S IN SWRN IA. OUR NEXT CHANCE FOR PCPN...IN THE FORM OF SNOW SHOWERS...WILL COME WITH A REINFORCING PUSH OF COLD AIR MONDAY NIGHT. THE BEST CHANCE FOR LIGHT ACCUMULATIONS...SAY ONE OR TWO TENTHS OF AN INCH...WILL BE ACROSS NERN NE AND WRN IA. EXPECT A DECENT RANGE OF HIGH TEMPERATURES ON TUESDAY...VARYING FROM THE UPPER SINGLE DIGITS NORTHEAST OF OMAHA TO LOWER 20S NEAR THE KS BORDER. HIGH PRESSURE AT THE SURFACE WILL BUILD DOWN OVER THE AREA DURING THE DAY. WINDS WILL BE SOMEWHAT GUSTY INTO EARLY AFTERNOON...THEN SLOWLY DECREASE. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 315 AM CST SUN JAN 10 2016 AT LEAST THE FIRST HALF OF TUESDAY NIGHT WILL BE COLD...WITH LOWS MAINLY IN THE SINGLE DIGITS. LOW LEVEL WARM AIR ADVECTION DEVELOPS DURING THE NIGHT AND TEMPERATURES SHOULD START TO RISE LATE. HIGHS WEDNESDAY WILL BE MAINLY IN THE UPPER 20S TO MID 30S AS WARMER AIR MOVES IN FROM THE WEST. MODELS HAVE SIMILAR SOLUTIONS FOR THE 500 MB PATTERN FOR EARLY WEDNESDAY...WITH A RIDGE BACK OVER THE ROCKIES AND NORTHWEST FLOW OVER THE CENTRAL PLAINS. THAT RIDGE BREAKS DOWN FAIRLY FAST ON THURSDAY...AND THEN SOLUTIONS START TO DIVERGE. WILL INCLUDE SOME SMALL CHANCES FOR LIGHT SNOW FROM FRIDAY NIGHT INTO SATURDAY NIGHT FOR NOW. TEMPERATURES SHOULD START TO TURN AT LEAST A LITTLE COLDER BY NEXT WEEKEND. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 540 AM CST SUN JAN 10 2016 MAINLY VFR CONDITIONS SHOULD CONTINUE THROUGH THE PERIOD...HOWEVER PATCHY MVFR/IFR CLOUDS WILL NEED TO BE WATCHED. THERE IS A PATCH OF MVFR/IFR CLOUDS OVER PARTS OF CENTRAL NEBRASKA THAT COULD DRIFT TOWARD KOFK THIS MORNING. THE RUC TENDS TO DEVELOP THESE FARTHER SOUTH...SO WILL NEED TO MONITOR TRENDS. FOR NOW JUST INCLUDED A SCT LOW CLOUD DECK. A PATCH OF MID CLOUDS IN WESTERN NEBRASKA IS ALSO FORECAST TO PUSH EAST AND COULD AFFECT KLNK THIS AFTERNOON. THESE CLOUDS ARE ASSOCIATED WITH WARM AIR RETURNING TO THE REGION.THE MODELS ARE IN GOOD AGREEMENT WITH CLOUDS INCREASING AFTER MIDNIGHT AHEAD OF A SHORTWAVE TROUGH DROPPING SOUTH ACROSS NEBRASKA. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ011-012- 015>018-030>034-042>045-050>053-065>068. IA...WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR IAZ043-055- 056-069-079-080-090-091. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
303 AM CST SUN JAN 10 2016 .SYNOPSIS... ISSUED AT 3 AM CST SUN JAN 10 2016 THE UA PATTERN ACROSS NOAM TONIGHT REMAINS FAIRLY STAGNANT COMPARED TO 24 HRS AGO. CLOSED LOW PRESSURE WAS CENTERED OVER WESTERN PORTIONS OF THE HUDSON BAY OF CANADA. SOUTH OF THIS LOW...A TROUGH EXTENDED SOUTH INTO THE OZARKS AND CENTRAL GULF COAST STATES. EAST OF THIS FEATURE...RIDGING WAS PRESENT ACROSS THE CANADIAN MARITIMES INTO LABRADOR NEWFOUNDLAND AND NORTH TO SRN GREENLAND. WEST OF THE TROUGH...A RIDGE OF HIGH PRESSURE EXTENDED FROM OFF THE WEST COAST OF OREGON...NORTH INTO THE YUKON. AT THE SURFACE...COLD ARCTIC HIGH PRESSURE HAS PUSHED INTO EASTERN NEBRASKA OVERNIGHT AND AS OF 2 AM CST...WAS ROUGHLY CENTERED NEAR YORK NEBRASKA. COLD TEMPERATURES WERE PRESENT ACROSS THE FORECAST AREA WITH READINGS GENERALLY ZERO TO 10 BELOW ZERO. THE EXCEPTION WAS OVER PORTIONS OF NORTH CENTRAL NEBRASKA ALONG A CORRIDOR FROM EAST OF VALENTINE TO EAST OF BROKEN BOW WHERE CLOUDS WERE PRESENT. ANOTHER AREA OF "WARMER" TEMPERATURES WAS LOCATED IN THE EASTERN NEBRASKA PANHANDLE AND FAR SWRN NEBRASKA...WHERE A MID LEVEL DECK OF CLOUDS WAS PRESENT INVOF A MID LEVEL FRONTAL BOUNDARY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 3 AM CST SUN JAN 10 2016 PATCHY FOG ON THE WESTERN PERIPHERY OF THE MID LEVEL CLOUD DECK SHOULD TRACK SLOWLY EAST THROUGH MID MORNING AS THE MID LEVEL DECK TRANSITIONS EAST AS WELL. BOTH THE NAM AND HRRR HAVE SOME SUPPORT FOR FOG DEVELOPMENT IN THE FAR SWRN CWA THIS MORNING AND HAVE INSERTED IN A MENTION OF PATCHY FOG THROUGH 15Z THIS MORNING. FLURRIES WERE TAKEN OUT OF THE FORECAST FOR THIS MORNING...AS LIFT IN THE DENDRITIC LAYER HAS TRENDED MUCH WEAKER WITH THE PAST EVENINGS MODEL RUNS. ALSO...OBS ACROSS THE PANHANDLE AND FAR SWRN NEBRASKA HAVE BEEN SNOW FREE TONIGHT. AS FOR TEMPERATURES TODAY...HIGH PRESSURE WILL SLIDE SOUTH SOUTHEAST INTO EASTERN KANSAS...WHICH WILL ALLOW WARMER AIR ACROSS THE HIGH PLAINS...TO TRACK EAST INTO WESTERN AND CENTRAL NEBRASKA THIS AFTERNOON. BY 21Z THIS AFTERNOON...H85 TEMPS ACTUALLY REACH -2 TO -3C IN FAR SWRN NEBRASKA. WITH MIXING THIS WOULD FACILITATE HIGHS IN THE UPPER 30S TO AROUND 40. HOWEVER...WINDS WILL BE FAIRLY LIGHT THIS AFTERNOON...AND WE WILL BE BATTLING A MID LEVEL DECK OF CLOUDS...AT LEAST THROUGH THE FIRST HALF OF THE DAY...SO HAVE LIMITED HIGHS TO THE MIDDLE 30S IN THE SWRN CWA THIS AFTERNOON. ELSEWHERE...HIGHS WILL GENERALLY BE IN THE 20S WITH COOLEST READINGS IN THE FAR NORTHEASTERN CWA. FOR TONIGHT...A WEAK REINFORCING SHOT OF ARCTIC AIR WILL ATTEMPT TO PUSH INTO THE FAR NORTHEASTERN CWA TONIGHT WITH THE BULK OF THIS SECONDARY SURGE OF ARCTIC AIR REMAINING EAST OF THE FORECAST AREA. FURTHER WEST ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...OVERNIGHT LOWS WILL BE IN THE TEENS AND ARE EXPECTED TO BE HIT DURING THE LATE EVENING/EARLY OVERNIGHT HOURS AS A SHIELD OF MID LEVEL CLOUDS PUSH INTO THE FORECAST AREA FROM SOUTH DAKOTA OVERNIGHT. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 3 AM CST SUN JAN 10 2016 A SURFACE FRONT WILL OSCILLATE THROUGH NEBRASKA THROUGH MOST OF THE WEEK. HOWEVER...THERE IS NOT EXPECTED TO BE A CONNECTION TO A SOURCE OF SIGNIFICANT MOISTURE. THEREFORE...THE PROBABILITIES OF PRECIPITATION WITH EACH OSCILLATION WILL BE LOW. A WARM FRONT WILL BRING HIGHER TEMPERATURES TO CENTRAL AND WESTERN NEBRASKA MONDAY. FRONT RETURNS FROM THE NORTHEAST INTO NORTH CENTRAL AND NORTHEAST NEBRASKA MONDAY NIGHT AND WILL BRING COLDER TEMPERATURES AND A POSSIBILITY OF LIGHT SNOW TO THOSE AREAS. THE FRONT WILL THEN RETURN TO THE NORTH AND EAST WEDNESDAY BRINGING A RETURN OF SLIGHTLY HIGHER TEMPERATURES. FAIRLY QUIET WEATHER IS THEN EXPECTED UNTIL ANOTHER FRONT COMES THROUGH FRIDAY AND BRINGS THE POSSIBILITY OF LIGHT SNOW ONCE MORE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1125 PM CST SAT JAN 9 2016 PERSISTENT AREA OF STRATUS FROM SOUTH CENTRAL SOUTH DAKOTA ACROSS KVTN AND KANW WILL LINGER THROUGH THE EARLY MORNING HOURS BUT IS NOT EXPECTED TO EXPAND. OVER THE PANHANDLE AND SOUTHWEST NEBRASKA MID CLOUDS WILL CONTINUE WITH SOME AREAS OF LIGHT FOG. THIS AREA OF CLOUDS WILL MOVE EAST THROUGH THE EARLY MORNING HOURS AND MAY PRODUCE SOME FLURRIES. VFR CIGS AND VISIBILITIES ARE EXPECTED OVER MUCH OF THE AREA WITH IFR CIGS IN THE KANW TO KVTN AREA. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...SPRINGER AVIATION...POWER
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
930 PM EST MON JAN 11 2016 .SYNOPSIS... A LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES WILL BRING SNOW TO THE REGION TONIGHT INTO TUESDAY. COLD HIGH PRESSURE WILL BUILD INTO THE REGION ON WEDNESDAY...WITH DRIER CONDITIONS EXPECTED. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AN AREA OF SNOW HAS DEVELOPED IN SOUTH CENTRAL INDIANA AND IS LIFTING TOWARDS THE WHITEWATER VALLEY. THE RAP AND HRRR HAVE PICKED UP ON THIS AND THEY TAKE THIS AREA NORTHEAST THROUGH THE MIAMI VALLEY AND INTO NORTH CENTRAL OHIO. AFTER THIS PASSES THE LARGER AREA OF SNOW ASSOCIATED WITH THE FRONTOGENESIS IS THEN FORECAST TO DROP INTO THE FA. STILL LOOKING AT A COUPLE OF INCHES OF SNOW BEFORE MORNING IN THE NORTH AND AN INCH OR LESS IN THE SOUTH. TEMPERATURES WILL RISE FOR A GOOD PART OF THE NIGHT...REACHING THE UPPER 20S..BEFORE THE COLD AIR BEGINS TO RUSH IN FROM THE NW. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... AS THE INFLUENCE FROM THE SOUTHERN SURFACE RIDGE MOVES EAST OF THE REGION...SURFACE LOW PRESSURE IS BEGINNING TO DEVELOP IN THE UPPER MISSISSIPPI VALLEY. AS THIS LOW MOVES EAST AND STRENGTHENS...AN ARCTIC COLD FRONT WILL BEGIN TO QUICKLY MOVE OUT OF THE NORTHERN PLAINS...BRINGING A NOTABLE CHANGE IN AIR MASS TO THE GREAT LAKES AND OHIO VALLEY FOR TUESDAY. A WEAK SHORTWAVE WILL BE MOVING EAST INTO THE SOUTHERN GREAT LAKES AND NORTHERN OHIO VALLEY THIS EVENING...STRENGTHENING THE WARM ADVECTION FLOW (85OMB SPEED CONVERGENCE) AND ISENTROPIC ASCENT OVER THE REGION. IN RESPONSE...SNOW IS EXPECTED TO DEVELOP IN NORTHERN ILLINOIS AND NORTHERN INDIANA...SPREADING INTO THE NORTHWESTERN SECTIONS OF THE ILN FORECAST AREA BEFORE MIDNIGHT. AS THIS OCCURS...A STRONGER WAVE AND JET STREAK WILL BE QUICKLY MOVING OUT OF MANITOBA. THIS WILL EVENTUALLY ACT TO ENHANCE THE FIRST WAVE...ALONG WITH THE QUICKLY STRENGTHENING SURFACE LOW...AND THE PUSH OF COLD AIR ALONG THE DEVELOPING ARCTIC FRONT. THE MAJORITY OF ACCUMULATING SNOW IS EXPECTED TO DEVELOP ALONG AND AHEAD (PERHAPS WELL AHEAD) OF THE SURFACE FRONTAL BOUNDARY...IN RESPONSE TO FRONTAL FORCING ALOFT...AND FAVORABLE LEFT-EXIT JET POSITIONING. THE LACK OF WELL-FOCUSED FORCING IS ONE POTENTIAL LIMITING FACTOR FOR THIS EVENT...WITH NO REAL ANTICIPATION OF ANY BANDING. ANOTHER LIMITING FACTOR IS THE UNIMPRESSIVE MOISTURE PROFILES...WITH MOST OF THE ATMOSPHERIC MOISTURE CONFINED BELOW 700MB...AND ONLY INTERMITTENTLY FULLY SATURATED. MODEL SOUNDINGS DO INDICATE THE POTENTIAL FOR SLOWLY-COOLING PROFILES THROUGH THE DENDRITIC GROWTH ZONE FOR AT LEAST A FEW HOURS DURING THE EVENT...WHICH WOULD ALLOW FOR SOME BRIEFLY FAVORABLE CONDITIONS FOR EFFICIENT SNOW. WITH TEMPERATURES COOLING ALOFT...SNOW-TO-WATER RATIOS WILL GRADUALLY INCREASE...SOMEWHERE IN THE 14:1 TO 18:1 RANGE THROUGH MOST OF THE EVENT. THUS...IT MAY BE THE LACK OF AVAILABLE MOISTURE THAT KEEPS THIS FROM BEING A BIGGER SNOWFALL. ALL EXPECTATIONS ARE FOR A 6-8 HOUR PERIOD OF SNOW...WHICH MAY BE LIGHT AT TIMES...BUT WILL NONETHELESS ACCUMULATE ENOUGH TO CREATE HAZARDOUS CONDITIONS FOR THE TUESDAY MORNING COMMUTE. THE UPDATED SNOWFALL FORECAST RANGES FROM JUST OVER AN INCH IN THE SOUTHWESTERN CWA TO AROUND TWO A HALF INCHES IN THE NORTHEASTERN CWA. THESE NUMBERS FALL A LITTLE BELOW THE TRADITIONAL WINTER WEATHER ADVISORY CRITERIA...BUT EXPECTED IMPACTS FROM THE HORRIBLE TIMING (WITH RESPECT TO TRAVEL) AND INCREASING WINDS MADE THIS ADVISORY A FAIRLY EASY DECISION...ESPECIALLY WHEN THE AFTERNOON SNOW SHOWER / SNOW SQUALL THREAT (DISCUSSED BELOW) IS FACTORED IN. AS FOR THE WINDS...SOUTHWESTERLY FLOW WILL BECOME SLIGHTLY GUSTY DURING THE SAME TIME FRAME AS THE ACCUMULATING SNOW...BUT STRONGER WESTERLY WINDS WILL OCCUR ALONG AND BEHIND THE FRONT. GUSTS ARE EXPECTED TO PEAK OUT IN THE 30-35 KNOT RANGE FOR THE NORTHERN CWA...AND 25-30 KNOTS IN THE SOUTHERN CWA. THIS WILL NOT REQUIRE A WIND ADVISORY...BUT DOES FACTOR INTO THE WINTER WEATHER HAZARDS COVERED IN THE CURRENT HEADLINE. AGAIN...OVER-MIXING IN GFS BOUNDARY LAYER PROFILES LED TO THEIR EXCLUSION FROM CONSIDERATION IN DEVELOPING THE WIND GUST FORECAST. A SECONDARY THREAT WILL DEVELOP DURING THE LATE MORNING AND EARLY AFTERNOON...AS THE CHANGE OF AIR MASS BRINGS THE POTENTIAL FOR SNOW SHOWERS AND SNOW SQUALLS. ALONG AND BEHIND THE ARCTIC FRONT...THE BOUNDARY LAYER WILL BECOME WELL-MIXED IN A STRONG COLD ADVECTION PATTERN. THOUGH LARGER-SCALE MODELS CONTINUE TO DEPICT ONLY MEAGER QPF BEHIND THE PRIMARY MORNING AREA OF SNOW...SOUNDINGS CLEARLY INDICATE THE FAVORABLE CONDITIONS FOR SNOW SHOWER DEVELOPMENT...ESPECIALLY DURING THE LATE MORNING AND EARLY AFTERNOON. AHEAD OF THE POTENTIAL VORTICITY ANOMALY...WEAK/SHALLOW CONVECTIVE INSTABILITY IS EXPECTED TO DEVELOP (AT LEAST PARTIALLY) WITHIN THE DENDRITIC GROWTH ZONE...WITH CONSISTENTLY COOLING 850MB TEMPS. IN COMPARISON TO THE MORE SIGNIFICANT SNOW SQUALL DAYS IN THE ILN FORECAST AREA...THIS ONE IS A LITTLE WEAKER WITH THE PV ANOMALY...AS WELL AS THE STRENGTH OF THE LOW-LEVEL WIND FLOW. NONETHELESS...CONDITIONS ARE FAVORABLE FOR WIDESPREAD FLURRIES AND SCATTERED SNOW SHOWERS...WITH THE POTENTIAL FOR A FEW HEAVIER BANDS / SNOW SQUALLS TO DEVELOP. WRF-NMM/WRF-ARW SIMULATED REFLECTIVITY FORECASTS WERE USEFUL IN ASSESSING THE EXPECTED SNOW SHOWER LAYOUT...THOUGH BOTH MODELS FOCUS THE ACTIVITY VERY CLOSE TO THE ARCTIC BOUNDARY...WHEN AT LEAST SOME SNOW SHOWER ACTIVITY SEEMS LIKELY TO CONTINUE A LITTLE BEYOND THAT. THE WINTER WEATHER ADVISORY TIMING WAS CONTINUED THROUGH THE AFTERNOON TO ACCOUNT FOR THIS POSSIBILITY...AND THE THREAT FOR ISOLATED POCKETS OF REDUCED VISIBILITIES AND GUSTY CONDITIONS. WITH COLD ADVECTION CONTINUING THROUGH THE DAY AND INTO TUESDAY NIGHT...COMBINED WITH ANOTHER LAYER OF SNOW...VERY COLD CONDITIONS ARE EXPECTED BY EARLY WEDNESDAY MORNING. THE MIN TEMP FORECAST WAS ADJUSTED DOWN BY 2-3 DEGREES...WITH SINGLE DIGITS EXPECTED FOR THE ENTIRE FORECAST AREA. SOME COOL SPOTS IN THE NORTHERN CWA MAY APPROACH ZERO. WITH WINDS REMAINING IN PLACE AT AROUND 10 KNOTS...THE FAR NORTHERN CWA WILL HAVE WIND CHILLS OF AROUND -10F...LIKELY REQUIRING AN ADVISORY IN THE FUTURE. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... ARCTIC HIGH PRESSURE WILL TRAVERSE THE REGION ON WEDNESDAY. WAA INDUCED CLOUDS WILL OVERSPREAD THE REGION DURING THE DAY AHEAD OF AN ADVANCING WARM FRONT. HIGHS WILL REMAIN COLD...RANGING FROM THE UPPER TEENS NORTH TO THE MID 20S SOUTH. MODELS NOW SUGGEST THAT AN EMBEDDED S/WV IN THE NORTHWEST FLOW MAY BE A LITTLE MORE ROBUST AND SLIGHTLY FARTHER SOUTH FOR WEDNESDAY NIGHT. THIS WILL BRING A CHANCE OF LIGHT SNOW TO LOCATIONS GENERALLY ALONG AND NORTH OF I-70 WEDNESDAY EVENING INTO EARLY MORNING AS THE ASSOCIATED WARM FRONT PASSES THROUGH THE REGION. SNOW ACCUMULATIONS WILL BE LESS THAN AN INCH. OVERNIGHT LOWS WILL BE FAIRLY STEADY FROM WEDNESDAYS HIGHS AND MAY EVEN RISE SOME...ESPECIALLY ACROSS OUR SOUTHWEST CWFA. THURSDAY WILL BE AN IN BETWEEN DAY IN TERMS OF WEATHER SYSTEMS WITH GENERALLY PARTLY CLOUDY SKIES AND WARMER TEMPERATURES. HIGHS WILL RANGE FROM THE UPPER 30 NORTH TO THE MID 40S SOUTH. FOR THE REMAINDER OF THE EXTENDED...MODELS ARE STILL STRUGGLING ON HOW THE SOUTHERN BRANCH OF THE JET STREAM WILL INTERACT WITH THE NORTHERN BRANCH...EITHER PHASING OR NOT PHASING. THIS FORECAST PACKAGE RELIES ON WPC EXPERTISE WHICH SUGGESTS THAT THE PREVIOUS AND CURRENT ECMWF MODEL MAY BE HANDLING A LOW PRESSURE SYSTEM THAT IS FORECAST TO MOVE NORTHEAST THROUGH THE GREAT LAKES AND OHIO VALLEY FRIDAY INTO SATURDAY THE BEST. AS A RESULT...UPPER LEVEL ENERGY EJECTING OUT OF THE SOUTHERN PLAINS WILL BRING MOISTURE NORTHWARD INTO THE AREA FRIDAY INTO FRIDAY NIGHT. IT NOW APPEARS IT WILL BE WARM ENOUGH FOR THE PRECIPITATION TO BEGIN AS RAIN AND REMAIN RAIN THROUGH THE DAY FRIDAY. BY FRIDAY NIGHT INTO SATURDAY...COLDER AIR FILTERING INTO THE REGION ON THE BACK SIDE OF THE LOW WILL TRANSITION THE RAIN TO SNOW SHOWERS. FOR THE UPCOMING WEEKEND...THERE WILL BE A LINGERING THREAT FOR SNOW SHOWERS AS MUCH COLDER AIR MOVES ACROSS THE WARMER WATERS OF THE GREAT LAKES. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS ARE OVER THE TAFS AS THEY WAIT FOR ARRIVAL OF THE NEXT WEATHER SYSTEM LATER TONIGHT. SNOW WILL WORK IN FROM NRN INDIANA...REACHING KDAY AROUND 03Z. AS IT BUILDS SOUTH AND EAST...IT SHOULD REACH THE KCMH/KLCK AROUND 06Z AND KCVG/LUK SHORTLY AFTERWARDS. CIGS AND VSBYS WILL DROP TO MVFR WITH THE ONSET OF THE SNOW. IFR CONDITIONS ARE DURING THE HEART OF THE STORM BETWEEN 09-14Z. WINDS WILL ALSO PICK UP WITH THE ONSET OF THE SNOW...INCREASING FROM 15-25KTS WITH GUSTS OF 25-30KTS TO 20-30KTS AND GUSTS OVER 30KTS AFTER 12Z AS CAA REALLY KICKS IN. BEHIND THE SYSTEM...SCATTERED SNOW SHOWERS WILL BE POSSIBLE INTO THE EARLY AFTERNOON...BUT THEN THE FETCH WORKS OFF LAKE MICHIGAN. MVFR CLOUDS SHOULD LINGER INTO THE AFTERNOON...THEN BEGIN TO SCATTERED OUT IN THE EXTENDED CVG TAF PERIOD. OUTLOOK...MVFR CIGS AND VSBYS ARE POSSIBLE WEDNESDAY NIGHT INTO THURSDAY MORNING AND AGAIN FRIDAY INTO SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR OHZ045-046-054>056-063>065-070>074-077-078-080-082. WINTER WEATHER ADVISORY UNTIL 3 PM EST TUESDAY FOR OHZ026-034- 035-042>044-051>053-060>062. WINTER WEATHER ADVISORY FROM 5 AM TO 7 PM EST TUESDAY FOR OHZ079-081-088. KY...WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR KYZ089>093. WINTER WEATHER ADVISORY FROM 5 AM TO 7 PM EST TUESDAY FOR KYZ094>100. IN...WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR INZ058-059-066-073>075-080. WINTER WEATHER ADVISORY UNTIL 3 PM EST TUESDAY FOR INZ050. && $$ SYNOPSIS...HATZOS/SITES NEAR TERM...SITES SHORT TERM...HATZOS LONG TERM...HICKMAN AVIATION...SITES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
107 AM EST SUN JAN 10 2016 .SYNOPSIS... A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE THROUGH THE AREA TONIGHT...BRINGING RAIN TO THE REGION. THE RAIN WILL CHANGE TO SNOW AS TEMPERATURES BEGIN TO DROP ON SUNDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE OHIO VALLEY ON MONDAY...BEFORE A COLD FRONT MOVES INTO THE AREA ON TUESDAY...PROVIDING ANOTHER CHANCE OF SNOW. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... LATEST RUNS OF THE RAP AND HRRR HAVE INTENSIFIED THE PCPN AREA IN THE TRANSITION ZONE FROM RAIN TO SNOW AT THE END OF TONIGHT INTO EARLY SUNDAY MORNING. THEREFORE THERE COULD BE AN ENHANCED BAND OF SNOW ACROSS THE WESTERN HALF OF THE FA WHICH COULD PRODUCE BETWEEN 1 AND 2 INCHES. WINDS WILL GUST OVER MPH AS THE SNOW COMES IN, CAUSING ADDITIONAL TRAVEL DIFFICULTIES. THEREFORE ISSUED A WINTER WEATHER ADVISORY. INCLUDED OWEN, GRANT, CARROLL AND GALLATIN COUNTIES IN THE ADVISORY WHERE AN INCH OR LESS IS EXPECTED IN ORDER TO LINE OF WITH ADVISORIES ALREADY OUT TO THE WEST. STILL EXPECTING LOWS RANGING FROM AROUND 30 IN SE INDIANA TOMORROW MORNING TO AROUND 40 IN PORTIONS OF THE SCIOTO VALLEY. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... BY EARLY SUNDAY MORNING...A STRONG SURFACE FRONT WILL BE ENTERING THE ILN FORECAST AREA FROM THE WEST...SPEEDING UP AS IT MOVES EAST THROUGH THE MIDDLE OHIO VALLEY. THIS FRONT WILL HAVE PIVOTED TO AN ALMOST PERFECTLY NORTH-TO-SOUTH ORIENTATION...SEPARATING TEMPERATURES IN THE 40S ON ITS EAST SIDE FROM TEMPERATURES IN THE 20S ON ITS WEST SIDE. AS SURFACE LOW PRESSURE STRENGTHENS AND MOVES ALONG THE BOUNDARY...NORTH-NORTHEAST THROUGH THE OHIO...NEGATIVE THETA-E ADVECTION WILL BECOME QUITE POTENT. THE STRONG PRESSURE AND TEMPERATURE GRADIENT WILL MARK A SIGNIFICANT SHIFT IN WEATHER CONDITIONS...AS COLDER AND DRIER AIR BEGINS TO MOVE INTO THE REGION...AND CONTINUES TO DO SO THROUGHOUT THE DAY ON SUNDAY. TEMPERATURES ARE EXPECTED TO FALL THROUGH THE ENTIRE DAY...DROPPING AS MUCH AS 20-30 DEGREES FROM SUNDAY MORNING TO SUNDAY NIGHT. THE STRONGEST FORCING WITH THE FRONT APPEARS TO BE FOUND IN THE LOW LEVELS. MODELS SHOW THAT LOW-LEVEL DEFORMATION AND COLD ADVECTION LINE UP NICELY ACROSS THE FORECAST AREA BETWEEN 09Z AND 15Z. WEAKER FRONTAL FORCING ALOFT WILL LAG SLIGHTLY BEHIND...BUT ONLY BY A FEW HOURS. THIS MEANS THAT THE TIMING FOR THE MAJORITY OF THE FRONTAL PRECIPITATION WILL NOT EXTEND SIGNIFICANTLY INTO THE DAY ON SUNDAY...AS DRIER DEEP-LAYER AIR MOVES INTO THE REGION...AND FORCING SHUTS DOWN BY MID-DAY. THE GREATEST CHALLENGE WITH THE FORECAST IS ASSESSING HOW MUCH POTENTIAL FOR PRECIPITATION WILL STILL EXIST AS TEMPERATURES BECOME COLD ENOUGH FOR SNOW. THERE IS DEFINITELY SOME OVERLAP...BUT THE MAJORITY OF THE PRECIPITATION (IN TERMS OF LIQUID PERCENTAGE) WILL LIKELY FALL AS RAIN. OVERALL EXPECTATIONS FOR THE ILN FORECAST AREA HAVE NOT CHANGED TOO MUCH WITH REGARDS TO SNOW NUMBERS...WITH AROUND AN INCH TO THE NORTH OF A LINE FROM BATESVILLE INDIANA TO DELAWARE OHIO...AND LESSER AMOUNTS TO THE SOUTH (PERHAPS VERY LITTLE IN THE FAR SOUTHEASTERN CWA). A STRONGER SURFACE LOW THAN CURRENTLY ANTICIPATED COULD INCREASE THE POTENTIAL FOR BANDED FORCING ON ITS BACK SIDE...SO THERE IS A CHANCE THAT THE FAR WESTERN AND NORTHWESTERN SECTIONS OF THE CWA MAY REQUIRE AN UPWARD ADJUSTMENT TO THE FORECAST...IF THIS SCENARIO ENDS UP APPEARING MORE LIKELY. GUSTY WINDS WILL ALSO REMAIN IN THE FORECAST BEHIND THE FRONT. THE STRONGEST GUSTS (35-40 MPH) ARE EXPECTED IN THE NORTHERN CWA...WHERE THE PRESSURE GRADIENT FROM THE SURFACE LOW WILL BE STRONGEST. MOMENTUM TRANSFER WAS EXAMINED ON BUFKIT FROM SEVERAL MODELS...THOUGH AS USUAL THE 12Z GFS GUSTS WERE DISCARDED AS TOO STRONG. BEHIND THE COLD FRONT...A SHALLOW LAYER OF MOISTURE AT THE TOP OF THE MIXED LAYER WILL LIKELY KEEP SKIES CLOUDY TO MOSTLY CLOUDY THROUGH EVENING...BEFORE THE STRATOCUMULUS BEGINS TO ERODE OVERNIGHT. AS THIS MOIST LAYER WILL INTERSECT THE DENDRITIC GROWTH ZONE...SOME FLURRIES WILL LIKELY BE POSSIBLE FOR SEVERAL HOURS AFTER THE CHANCE FOR ACCUMULATING SNOW HAS ENDED. IF THE CURRENT FORECAST HOLDS...AND SNOW IS MEASURED AT CVG ON SUNDAY MORNING...THERE WILL BE NO NEW RECORD FOR LATEST FIRST SNOWFALL IN A WINTER SEASON. THE OLD RECORD WAS SET WHEN A TENTH OF AN INCH FELL ON JANUARY 12 1983. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE FIRST PART OF THE LONG TERM PERIOD WILL FEATURE THE CONTINUATION OF A COLD WEATHER PATTERN AS A LONG WAVE TROUGH DIGS INTO SOUTHEAST CANADA...THE GREAT LAKES...THE OHIO VALLEY AND THE NEW ENGLAND REGION. ON MONDAY...THERE WILL BE A BRIEF RESPITE IN THE THREAT FOR PRECIPITATION AS SURFACE HIGH PRESSURE QUICKLY SHUNTS OFF TO THE EAST. SKIES WILL GENERALLY START OUT MOSTLY SUNNY WITH CLOUDS INCREASING FROM WEST TO EAST AHEAD OF THE NEXT WEATHER SYSTEM. HIGHS WILL STAY BELOW FREEZING...RANGING FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. FOR MONDAY NIGHT INTO TUESDAY...AN ARCTIC COLD FRONT WILL PUSH SOUTHEAST THROUGH THE GREAT LAKES AND OHIO VALLEY REGION. A LEAD S/WV AND MODEST ISENTROPIC LIFT IS EXPECTED FIRST BEFORE THE FRONT ARRIVES. THIS WILL START SPREADING LIGHT SNOW INTO OUR NORTHWEST ZONES MONDAY EVENING INTO EARLY TUESDAY MORNING. A STRONGER S/WV IN ASSOCIATION WITH THE ARCTIC COLD FRONT WILL THEN CAUSE A SYNOPTIC SCALE RESPONSE...WHICH WILL MANIFEST ITSELF AS A BAND OF SNOW ALONG AND AHEAD OF THE FRONT DURING TUESDAY MORNING. THIS PRECIPITATION WILL LIKELY BE ARRIVING FOR THE MORNING COMMUTE FOR MOST LOCATIONS. SNOW TOTALS MONDAY NIGHT INTO TUESDAY MORNING WILL LIKELY RANGE FROM 1 TO 2 INCHES NORTH OF THE OHIO RIVER...AND AROUND AN INCH SOUTH OF THE OHIO RIVER. THE ARRIVAL OF THE SNOW LOOKS TO OCCUR DURING THE MORNING COMMUTE...AND WITH INCREASING GUSTY WINDS...IT WILL POSE A TRAVEL HAZARD. ONCE THE FRONT PASSES EAST OF THE REGION BY EARLY AFTERNOON...STRONG CAA...STEEPENING LOW LEVEL LAPSE RATES...AND LINGERING SHALLOW LOW LEVEL MOISTURE WILL TRANSITION THE SNOW TO SCATTERED SNOW SHOWERS. THE NWS BURLINGTON SNOW SQUALL PARAMETER INDICATES THAT SOME OF THE SNOW SHOWERS MAY BE ROBUST...CAPABLE OF DROPPING VISIBILITIES QUICKLY IN A SHORT PERIOD OF TIME ALONG WITH A QUICK MINOR ACCUMULATION. HIGHS TUESDAY WILL BE EARLY...WITH FALLING TEMPERATURES EXPECTED DURING THE DAY. FOR TUESDAY NIGHT...SCATTERED SNOW SHOWERS WILL TAPER TO A FEW FLURRIES DURING THE EVENING...WITH SKIES BECOMING PARTLY CLOUDY TOWARD WEDNESDAY MORNING AS ARCTIC HIGH PRESSURE BUILDS INTO THE OHIO VALLEY FROM THE WEST. THE COLDEST LOWS OF THE WEEK ARE EXPECTED BY WEDNESDAY MORNING WITH SINGLE DIGITS ALONG AND NORTH OF THE OHIO RIVER AND LOWER TEENS SOUTH. ALTHOUGH WINDS WILL GRADUALLY DECREASE...THEY WILL BE STRONG ENOUGH TO PRODUCE COLD WIND CHILL VALUES AROUND 10 BELOW NORTH AND FROM 5 BELOW TO ZERO SOUTH. THE ARCTIC HIGH WILL TRAVERSE THE REGION ON WEDNESDAY WITH PARTLY TO MOSTLY SUNNY SKIES FORECAST. HIGHS WILL BE COLD...RANGING FROM THE MID TEENS NORTH TO THE LOWER 20S SOUTH. FOR WEDNESDAY NIGHT INTO THURSDAY...A WEAK COLD FRONT IS EXPECTED TO PASS THROUGH THE REGION BRING A SMALL CHANCE OF SNOW SHOWERS. FOR THE REMAINDER OF THE EXTENDED...FRIDAY AND INTO THE WEEKEND...MODELS DIFFER ON HOW FAST COLD AIR WILL MODIFY AND HOW SOUTHERN STREAM ENERGY WILL IMPACT THE OHIO VALLEY. HAVE TAKEN A BLEND OF THE ECMWF AND WPC GUIDANCE WHICH BRING A LOW CHANCE OF SNOW TO THE REGION ON SATURDAY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... RAIN WILL CONTINUE TO MOVE ACROSS THE TAF SITES OVERNIGHT. VSBYS WILL BE REDUCED TO THE MVFR CATEGORY AT TIMES WITH SOME OF THE HEAVIER RAIN. MVFR AND IFR CIGS WILL MOVE INTO THE AREA. A COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY MORNING. RAIN WILL CHANGE OVER TO SNOW. VSBYS WILL BE FURTHER REDUCED WITH THE SNOW TO THE LIFR CATEGORY AND WIDESPREAD IFR CIGS ARE EXPECTED. WINDS WILL PICK UP AND BECOME GUSTY. WIND GUSTS OF AROUND 35 KNOTS WILL OCCUR AT TIMES FOR THE DAY ON SUNDAY. SNOW WILL TAPER OFF FROM WEST TO EAST THROUGH THE DAY AND CIGS WILL IMPROVE SLIGHTLY. LINGER MVFR CIGS AND WIND GUSTS INTO SUNDAY NIGHT. OUTLOOK...MVFR CIGS AND MVFR/IFR VSBYS ARE POSSIBLE MONDAY NIGHT INTO TUESDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER WEATHER ADVISORY FROM 5 AM TO 11 AM EST THIS MORNING FOR OHZ026-034-035-042>045-051>053-060>062-070>072-077- 078. KY...WINTER WEATHER ADVISORY FROM 5 AM TO 11 AM EST THIS MORNING FOR KYZ089>095. IN...WINTER WEATHER ADVISORY FROM 5 AM TO 11 AM EST THIS MORNING FOR INZ050-058-059-066-073>075-080. && $$ SYNOPSIS...HATZOS/SITES NEAR TERM...SITES SHORT TERM...HATZOS LONG TERM...HICKMAN AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
758 AM EST SUN JAN 10 2016 .SYNOPSIS... AN INTENSIFYING SFC LOW WILL TRACK NORTH THROUGH THE GREAT LAKES TODAY WITH A TRAILING COLD FRONT SWEEPING THROUGH PENNSYLVANIA LATE IN THE DAY. A DEEP UPPER LEVEL TROUGH WILL PIVOT THROUGH THE NORTHEAST CONUS EARLY NEXT WEEK...THEN LIFT OUT BY LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SLUG OF RAIN LIFTING THRU CENTRAL PA EARLY THIS MORNING AS POTENT SOUTHERN STREAM SHORTWAVE AND ASSOC SFC LOW TRACK WEST OF PA. MRMS RAINFALL ESTIMATES AT 10Z JUST TOPPING 1 INCH ACROSS PORTIONS OF FRANKLIN/ADAMS COUNTIES AND LATEST HRRR OUTPUT SUGGESTS THE CORRIDOR OF HEAVIEST RAIN /AT NOSE OF ANOMALOUS SERLY LL JET/ WILL RUN FROM THE LOWER SUSQ VALLEY NE INTO THE POCONOS...WHERE OROGRAPHIC ENHANCEMENT COULD PUSH TOTALS TO NEAR 1.5 INCHES BY LATE AM. 6HR FFG VALUES ARND 2.5 INCHES IN THIS AREA...SO NOT EXPECTING ANYTHING MORE THAN MINOR POOR DRAINAGE FLOODING THIS AM. STEADY RAIN WILL TAPER OFF BY ARND MIDDAY...AS ANOMALOUS LL JET/PWAT PLUME LIFTS NORTH OF THE REGION. CENTRAL PA WILL BRIEFLY BREAK INTO THE WARM SECTOR LATER TODAY...ALLOWING READINGS TO JUMP TO NR 50F ACROSS THE CENTRAL MTNS AND POSSIBLY APPROACH 60F ACROSS LANCASTER CO. A STRONG COLD FRONT WILL SWEEP THROUGH THE REGION THIS AFTN...ACCOMPANIED BY SCT SHOWERS THEN FOLLOWED BY STRONG WIND GUSTS AND A PERIOD OF LIGHT OROGRAPHIC SNOW OVR THE ALLEGHENY PLATEAU. WILL LIKELY ADD SLIGHT CHC OF A TSRA...AS EXAMINATION OF MDL SOUNDINGS INDICATES SOME MARGINAL INSTABILITY AHEAD OF FRONT THIS AFTN. SYNOPTIC SETUP FAVORABLE FOR HIGH POST-FRONTAL WINDS LATE TODAY/TONIGHT...WITH INTENSIFYING SFC LOW TRACKING ACROSS THE E GRT LKS...STRONG SUBSIDENCE AND ISSALLOBARIC COUPLET PASSAGE. BUFKIT SOUNDINGS SUPPORT WGUSTS BTWN 45-50KTS ACROSS THE ALLEGHENY PLATEAU/CENTRAL MTNS LATE TONIGHT AND THIS EVENING...SO HAVE ISSUED WIND ADVISORY. ALTHOUGH UPSLOPE SNOW IN WAKE OF FRONT WILL BE LIGHT...EVEN A LIGHT ACCUM...COMBINED WITH RAPIDLY FALLING TEMPS...COULD PRODUCE ICY ROAD CONDS. LATEST NCAR MESO ENSEMBLE SUPPORTS LIGHT ACCUMS OF LESS THAN AN INCH ACROSS THE ALLEGHENIES BY EARLY EVENING. WILL MENTION ICY ROAD THREAT IN THE NPW. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... STRONG/GUSTY WINDS WILL ONLY SLOWLY SUBSIDE OVERNIGHT...AS REGION REMAINS WITHIN TIGHT PRES GRADIENT SOUTH OF INTENSIFYING SFC LOW. BUFKIT SOUNDINGS INDICATE OCNL GUSTS NEAR ADVISORY CRITERIA COULD LAST MUCH OF THE NIGHT ACROSS THE W MTNS. PLUMMETING TEMPS...COMBINED WITH THE GUSTY WINDS...WILL LIKELY CREATE WCHILLS NEAR ZERO ACROSS THE W MTNS BY MON AM. THE OTHER ISSUE WILL BE LAKE EFFECT SNOW ACROSS THE NW MTNS. FALLING INVERSION HEIGHT WILL LIMIT SNOW POTENTIAL. NCAR MESO ENSEMBLE OUTPUT SUPPORTS TOTAL ACCUMS NR 4 INCHES ACROSS NW WARREN CO BY LATE MON MORNING...BUT LIKELY NOT MEETING ADVISORY CRITERIA OF 3+ IN 12HRS. RIDGE OF HIGH PRES WILL BUILD IN FROM THE OHIO VALLEY ON MONDAY...BRINGING MSUNNY SKIES ACROSS SOUTHERN PA AND DIMINISHING LE SNOW SHOWERS ACROSS THE NW MTNS. ENS MEAN 8H TEMPS OF JUST -16C SHOULD TRANSLATE TO MAX TEMPS FROM ARND 20F ACROSS THE NW MTNS...TO ARND 30F OVR THE LOWER SUSQ VALLEY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... CLIPPER WILL PASS NORTH OF PA ON TUESDAY. THE COMBINATION OF STRONG HEIGHT FALLS AND WARM ADVECTION AHEAD OF THIS SYSTEM SHOULD RESULT IN SEVERAL BANDS OF SNOW SHOWERS AHEAD AND ALONG THE TRAILING COLD FRONT. WHILE TEMPERATURES SHOULD CLIMB INTO THE MID TO UPPER 30S ACROSS THE SE...THE COMBINATION OF COLD AIR ALOFT AND DRY AIR SHOULD RESULT IN AT LEAST A FEW FLURRIES...LIGHT SNOW SHOWERS...ACROSS THE SE. FOR LATER TUESDAY NIGHT INTO WED...AS WINDS SHIFT MORE TO THE WEST THEN W TO NW LATER ON...NW AREAS AND THE HIGHLANDS SHOULD SEE SOME SNOW. TEMPERATURES SHOULD SLOWLY MODERATE BY LATE WEEK. FOR NOW...LOOKS LIKE THE NORTHERN STREAM PREVAILS. WENT WITH A DRY FCST FOR NEXT SAT. HOWEVER...SOMETHING TO WATCH...GIVEN SPLIT FLOW. OVERALL...JUST MADE MINOR ADJUSTMENTS TO THE PACKAGE AT THIS PT. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... SE FLOW AND AREAS OF RAIN CONTINUE THIS MORNING AS DEEPENING SURFACE LOW SLIDES INTO THE EASTERN GREAT LAKES. THIS IS KEEPING WIDESPREAD RESTRICTIONS IN PLACE...THOUGH BRIEF IMPROVEMENTS HAVE BEEN OCCURING OVER THE WEST OVER PAST SEVERAL HOURS AS A DRY SLOT ALOFT WORKS IN FROM THE SW. LLWS FROM ANOMOLOUS LL JET WILL ALSO TAPER BACK TEMPORARILY LATER THIS MORNING AS JET CORE LIFTS TO THE NE...TAKING MOST OF PRECIP ALONG WITH IT. OVERALL...RESTRICTIONS WILL PERSIST UNTIL A POTENT COLD FRONT SWEEPS THROUGH THIS AFTERNOON...BRINGING BIG CHANGES. FLOW WILL TURN SW AND THEN WESTERLY...REMAINING STRONG OFF THE SURFACE BUT ALSO MIXING THOSE STRONGER WINDS DOWN /AS STRONG ISSALLOBARIC COUPLET MOVES THROUGH/ THIS AFTERNOON AND TONIGHT WITH GUSTS UP TO 40 MPH OVER THE EAST AND 50 MPH IN WESTERN HIGHER TERRAIN. DOWNSLOPE FLOW WILL BRING CIG IMPROVEMENTS TO VFR OVER THE EAST...WHILE UPSLOPE AND PROXIMITY TO UPPER LOW WILL KEEP CIG RESTRICTIONS IN PLACE OVER THE WEST. AS COLDER AIR FILTERS IN...SNOW SHOWER ACTIVITY WILL INCREASE FOR THE NW MTNS /KBFD/ AND LAUREL HIGHLANDS /KJST/ STARTING LATE THIS AFTERNOON INTO TONIGHT AS WELL. OUTLOOK... MON...A FEW LOCALIZED BANDS OF LOW CIGS AND VSBYS IN SNOW SHOWERS ACROSS THE LAUREL HIGHLANDS AND NW MTNS. OTHERWISE...QUITE BREEZY WITH NO WIDESPREAD SIG WX RESTRICTIONS EXPECTED. TUE...CIG REDUCTIONS LIKELY NW HALF INTO PORTIONS OF CENTRAL MTNS IN LIGHT SNOW. VFR SE. WED-THU...CIG REDUCTIONS LIKELY NW HALF IN SNOW SHOWERS. VFR ELSEWHERE. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR PAZ004>006-010>012-017>019-024-025-033-034-037-041-045. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
601 AM EST SUN JAN 10 2016 .SYNOPSIS... AN INTENSIFYING SFC LOW WILL TRACK NORTH THROUGH THE GREAT LAKES TODAY WITH A TRAILING COLD FRONT SWEEPING THROUGH PENNSYLVANIA LATE TODAY. A DEEP UPPER LEVEL TROUGH WILL PIVOT THROUGH THE NORTHEAST CONUS EARLY NEXT WEEK...THEN LIFT OUT BY LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SLUG OF RAIN LIFTING THRU CENTRAL PA EARLY THIS MORNING AS POTENT SOUTHERN STREAM SHORTWAVE AND ASSOC SFC LOW TRACK WEST OF PA. MRMS RAINFALL ESTIMATES AT 10Z JUST TOPPING 1 INCH ACROSS PORTIONS OF FRANKLIN/ADAMS COUNTIES AND LATEST HRRR OUTPUT SUGGESTS THE CORRIDOR OF HEAVIEST RAIN /AT NOSE OF ANOMALOUS SERLY LL JET/ WILL RUN FROM THE LOWER SUSQ VALLEY NE INTO THE POCONOS...WHERE OROGRAPHIC ENHANCEMENT COULD PUSH TOTALS TO NEAR 1.5 INCHES BY LATE AM. 6HR FFG VALUES ARND 2.5 INCHES IN THIS AREA...SO NOT EXPECTING ANYTHING MORE THAN MINOR POOR DRAINAGE FLOODING THIS AM. STEADY RAIN WILL TAPER OFF BY ARND MIDDAY...AS ANOMALOUS LL JET/PWAT PLUME LIFTS NORTH OF THE REGION. CENTRAL PA WILL BRIEFLY BREAK INTO THE WARM SECTOR LATER TODAY...ALLOWING READINGS TO JUMP TO NR 50F ACROSS THE CENTRAL MTNS AND POSSIBLY APPROACH 60F ACROSS LANCASTER CO. A STRONG COLD FRONT WILL SWEEP THROUGH THE REGION THIS AFTN...ACCOMPANIED BY SCT SHOWERS THEN FOLLOWED BY STRONG WIND GUSTS AND A PERIOD OF LIGHT OROGRAPHIC SNOW OVR THE ALLEGHENY PLATEAU. WILL LIKELY ADD SLIGHT CHC OF A TSRA...AS EXAMINATION OF MDL SOUNDINGS INDICATES SOME MARGINAL INSTABILITY AHEAD OF FRONT THIS AFTN. SYNOPTIC SETUP FAVORABLE FOR HIGH POST-FRONTAL WINDS LATE TODAY/TONIGHT...WITH INTENSIFYING SFC LOW TRACKING ACROSS THE E GRT LKS...STRONG SUBSIDENCE AND ISSALLOBARIC COUPLET PASSAGE. BUFKIT SOUNDINGS SUPPORT WGUSTS BTWN 45-50KTS ACROSS THE ALLEGHENY PLATEAU/CENTRAL MTNS LATE TONIGHT AND THIS EVENING...SO HAVE ISSUED WIND ADVISORY. ALTHOUGH UPSLOPE SNOW IN WAKE OF FRONT WILL BE LIGHT...EVEN A LIGHT ACCUM...COMBINED WITH RAPIDLY FALLING TEMPS...COULD PRODUCE ICY ROAD CONDS. LATEST NCAR MESO ENSEMBLE SUPPORTS LIGHT ACCUMS OF LESS THAN AN INCH ACROSS THE ALLEGHENIES BY EARLY EVENING. WILL MENTION ICY ROAD THREAT IN THE NPW. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... STRONG/GUSTY WINDS WILL ONLY SLOWLY SUBSIDE OVERNIGHT...AS REGION REMAINS WITHIN TIGHT PRES GRADIENT SOUTH OF INTENSIFYING SFC LOW. BUFKIT SOUNDINGS INDICATE OCNL GUSTS NEAR ADVISORY CRITERIA COULD LAST MUCH OF THE NIGHT ACROSS THE W MTNS. PLUMMETING TEMPS...COMBINED WITH THE GUSTY WINDS...WILL LIKELY CREATE WCHILLS NEAR ZERO ACROSS THE W MTNS BY MON AM. THE OTHER ISSUE WILL BE LAKE EFFECT SNOW ACROSS THE NW MTNS. FALLING INVERSION HEIGHT WILL LIMIT SNOW POTENTIAL. NCAR MESO ENSEMBLE OUTPUT SUPPORTS TOTAL ACCUMS NR 4 INCHES ACROSS NW WARREN CO BY LATE MON MORNING...BUT LIKELY NOT MEETING ADVISORY CRITERIA OF 3+ IN 12HRS. RIDGE OF HIGH PRES WILL BUILD IN FROM THE OHIO VALLEY ON MONDAY...BRINGING MSUNNY SKIES ACROSS SOUTHERN PA AND DIMINISHING LE SNOW SHOWERS ACROSS THE NW MTNS. ENS MEAN 8H TEMPS OF JUST -16C SHOULD TRANSLATE TO MAX TEMPS FROM ARND 20F ACROSS THE NW MTNS...TO ARND 30F OVR THE LOWER SUSQ VALLEY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... CLIPPER WILL PASS NORTH OF PA ON TUESDAY. THE COMBINATION OF STRONG HEIGHT FALLS AND WARM ADVECTION AHEAD OF THIS SYSTEM SHOULD RESULT IN SEVERAL BANDS OF SNOW SHOWERS AHEAD AND ALONG THE TRAILING COLD FRONT. WHILE TEMPERATURES SHOULD CLIMB INTO THE MID TO UPPER 30S ACROSS THE SE...THE COMBINATION OF COLD AIR ALOFT AND DRY AIR SHOULD RESULT IN AT LEAST A FEW FLURRIES...LIGHT SNOW SHOWERS...ACROSS THE SE. FOR LATER TUESDAY NIGHT INTO WED...AS WINDS SHIFT MORE TO THE WEST THEN W TO NW LATER ON...NW AREAS AND THE HIGHLANDS SHOULD SEE SOME SNOW. TEMPERATURES SHOULD SLOWLY MODERATE BY LATE WEEK. FOR NOW...LOOKS LIKE THE NORTHERN STREAM PREVAILS. WENT WITH A DRY FCST FOR NEXT SAT. HOWEVER...SOMETHING TO WATCH...GIVEN SPLIT FLOW. OVERALL...JUST MADE MINOR ADJUSTMENTS TO THE PACKAGE AT THIS PT. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... RESTRICTIONS CONTINUE OVERNIGHT AS STRONG SOUTHEASTERLY FLOW CONTINUES. THE NEXT WEATHER SYSTEM MOVES THROUGH TONIGHT INTO SUNDAY AS ANOTHER AREA OF DEEP MOISTURE ARRIVES. EXPECT IFR AT MOST TAF SITES OVERNIGHT...WITH IFR AND LOWER CIGS...AND VARIABLE VSBYS...AS RAIN SHOWERS SPREAD OVER THE REGION. EXPECT IFR AND LOWER VSBYS AT TIMES...ESPECIALLY AFTER 06Z AS THE AREA OF RAIN ARRIVES ALONG WITH AN INCREASE IN WINDS WITH LLWS DEVELOPING OVERNIGHT AND CONTINUING THROUGH THE FIRST HALF OF THE MORNING. IFR CIGS AND VSBYS REMAIN PROBABLY THROUGH THE FIRST HALF OF TOMORROW BUT WILL CONDITIONS WILL SWITCH QUICKLY AS A SHARP COLD FRONT CROSSES SUNDAY AFTERNOON. FLOW WILL TURN WESTERLY /AND STRONGER WINDS WILL MIX TO THE SURFACE/ WITH RESTRICTIONS BECOMING CONFINED TO WESTERN HIGHER TERRAIN AS PRECIP TURNS TO SNOW SHOWERS TOMORROW NIGHT. OUTLOOK... OVERNIGHT...CIGS LOWER WITH WIDESPREAD IFR RESTRICTIONS. AREAS OF RAIN. LLWS OVERNIGHT THROUGH TOMORROW MORNING. SUN...AM RAIN/LOW CIGS. TURNING QUITE WINDY WITH PM SHSN/BRIEF VIS REDUCTIONS POSSIBLE KBFD/KJST. WESTERLY WIND GUSTS ACROSS CENTRAL AND WRN PENN POSSIBLY TOPPING 40 KTS AT TIMES. MON...A FEW LOCALIZED BANDS OF LOW CIGS AND VSBYS IN SNOW SHOWERS ACROSS THE LAUREL HIGHLANDS AND NW MTNS. OTHERWISE...QUITE BREEZY WITH NO WIDESPREAD SIG WX RESTRICTIONS EXPECTED. TUE...CIG REDUCTIONS LIKELY NW HALF IN SNOW SHOWERS. VFR ELSEWHERE. WED...SCT CIG REDUCTIONS NW MTNS IN SCT SNOW SHOWERS. VFR ELSEWHERE. THU...FAIR AND MILDER && .CTP WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR PAZ004>006-010>012-017>019-024-025-033-034-037-041-045. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...MARTIN AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
332 PM EST SUN JAN 10 2016 .SHORT TERM...(TONIGHT AND MONDAY)... COLD ADVECTION INTO THE AREA WILL CAUSE TEMPERATURES TO CONTINUE TO PLUMMET THROUGH THE AFTERNOON AND EVENING...BOTTOMING OUT IN THE TEENS IN MOST SPOTS. LIGHT SNOW SHOWERS OR FLURRIES WILL PERSIST THROUGH THE EVENING IN THE NORTHERN HALF OF THE AREA AS A SECONDARY VORT MAX MOVES THROUGH ALONG WITH THE 850 MB THERMAL TROUGH...BUT WITH LITTLE TO NO ACCUMULATION OUTSIDE THE HIGHEST ELEVATIONS WHERE UPSLOPE WINDS MIGHT ENHANCE PRECIP SLIGHTLY. CLOUDS WILL BEGIN TO SCATTER OUT OF SOUTHERN AREAS IN THE NEXT FEW HOURS...BUT NORTHERN AREAS WILL LIKELY HANG ON TO BROKEN TO OVERCAST CLOUDS UNTIL EARLY MONDAY MORNING AS DEPICTED BY THE NAM. THE HRRR APPEARS TOO QUICK TO ERODE THE CLOUD COVER TONIGHT. ALL AREAS SHOULD BE CLEAR BY MID MORNING...BUT HIGH CLOUDS WILL BEGIN TO INCREASE LATE IN THE DAY AS THE NEXT UPPER TROUGH APPROACHES. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)... MONDAY NIGHT SKIES START OUT MOSTLY CLEAR AS COLD HIGH PRESSURE IS IN CONTROL. A SYSTEM MOVING DOWN FROM THE NW FROM CANADA AND ACROSS THE PLAINS INTO THE TN VALLEY TUESDAY WILL INCREASE CLOUDS AROUND SUNRISE. THERE STILL LOOKS LIKE NOT MUCH MOISTURE FOR IT TO WORK WITH AND WILL AFFECT MOSTLY THE NORTHERN SECTIONS. LOWS TUESDAY MORNING IN THE MID TO UPPER 20S WILL WARM INTO THE 30S TO LOWER 40S NORTH BUT FALL QUICKLY ONCE THE FRONT MOVES THROUGH DURING THE DAY. SNOWFALL AMOUNTS WILL BE HIGHEST ACROSS SOUTHWEST VIRGINIA AND THE NORTHEAST TENNESSEE MOUNTAINS POSSIBLY REACHING 1 TO 2 INCHES AT THE HIGHEST ELEVATIONS. AFTER A QUICK SHOT OF SNOW SHOWERS OR FLURRIES IN THE CENTRAL VALLEY TUESDAY AFTERNOON CLOUDS WILL AGAIN DECREASE TUESDAY NIGHT WITH TEMPERATURES DROPPING INTO THE TEENS TO LOWER 20S BY WEDNESDAY MORNING. AFTER ANOTHER COLD DAY AND NIGHT WEDNESDAY NIGHT AND THURSDAY TEMPERATURES BEGIN TO MODERATE AS FLOW BECOMES MORE WESTERLY. THURSDAY AND THURSDAY NIGHT WILL BE DRY AS HIGH PRESSURE CONTINUES. AS THE PATTERN CHANGES FRIDAY INTO THE WEEKEND THE UPPER FLOW BECOMES MORE SOUTHWEST. THERE WILL BE CONSIDERABLE CLOUD COVER. LOW PRESSURE MOVES OUT OF THE GULF INTO THE LOWER MS VALLEY FRIDAY WHICH INCREASES MOISTURE IN THE EASTERN TN VALLEY. TEMPERATURES SHOULD BE WARM ENOUGH FOR MOSTLY RAIN. ANOTHER SYSTEM MOVING DOWN FROM THE NW WILL JOIN WITH THE SOUTHERN SYSTEM FOR MORE PRECIPITATION SATURDAY INTO SUNDAY. NIGHT TIME LOWS WILL STAY MOSTLY IN THE MID TO UPPER 30S SO PRECIPITATION AGAIN MOSTLY RAIN THROUGH THE END OF THE EXTENDED. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 20 43 27 48 / 0 0 0 10 KNOXVILLE MCGHEE TYSON AIRPORT, TN 18 39 26 43 / 0 0 0 10 OAK RIDGE, TN 19 38 26 42 / 0 0 0 20 TRI CITIES AIRPORT, TN 18 37 22 38 / 10 0 10 40 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DGS/TD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1122 PM CST SAT JAN 9 2016 .UPDATE... FOR 06Z AVIATION DISCUSSION. && .DISCUSSION... UPDATING THE FORECAST TO ISSUE A WINTER WEATHER ADVISORY FOR NWRN MIDDLE TENNESSEE. COLD AIR IS QUICKLY APPROACHING FROM THE NW BEHIND THE SFC LOW OVER SRN KY AND ITS ASSOCIATED COLD FRONT. WITH THE COLD FRONT AS IT TRAVERSES THE CWA...SMALL HAIL AND BRIEF HEAVY RAIN CAN BE EXPECTED. WILL GET DRY SLOTTED BEHIND THAT FOR A WHILE UNTIL THE UPPER LOW (NOW OVER NE ARKANSAS) ROTATES VORT ENERGY AND DEFORMATION AXIS TOWARDS MIDDLE TN BEFORE PULLING NEWD OUT OF HERE. THE RAIN/SNOW LINE IS LOCATED IN SRN IL AND THE BOOTHEEL OF MO...AT THE BACK EDGE OF THE DEFORMATION ZONE FROM NEAR MEMPHIS TO EVANSVILLE. NEAR-FREEZING TEMPS SHOULD REACH OUR NWRN COUNTIES AS PRECIPITATION IN THE DEFORMATION ZONE MOVES NE AND PULLS OUT TOWARD DAWN. THE HRRR...LATEST RAP AND NAM SHOW ANYWHERE FROM A HALF INCH OF SNOW TO ONE AND A HALF INCHES OF SNOW ACCUMULATING OVER THE NW SOMETIME BETWEEN 05-13Z TONIGHT-TOMORROW MORNING. ROAD TEMPS ARE WARM...BUT THINK ABOUT AN INCH OF SNOW COULD ACCUMULATE ON ELEVATED SURFACES AND GRASS. THUS...WILL ISSUE A WINTER WX ADVISORY FOR SNOW OVER OUR FAR NNW COUNTIES FROM 06-12Z LATE TONIGHT. MADE ADJUSTMENTS TO QPF/SNOW GRIDS AND REMOVED THUNDER WORDING FOR EASTERN AREAS. ADJUSTED OVERNIGHT TEMP/DEWPOINT TRENDS AS WELL. UPDATE OUT SHORTLY. && .AVIATION... 06Z TAF DISCUSSION. BNA/CKV/CSV...COLD FRONT HAS MADE IT TO THE CUMBERLAND PLATEAU, WITH THE HEAVIEST PRECIPITATION NOW EAST OF THE MID STATE. DRY SLOT BETWEEN THE COLD FRONT AND THE OCCLUDED FRONT MOISTURE BACK TO OUR WEST IS ALLOWING FOR A PERIOD OF VFR CIGS BEFORE CONDITIONS DETERIORATE ONCE MORE WITH THE WRAP-AROUND MOISTURE. LOOK FOR LIGHT SNOW TO DEVELOP FROM WEST TO EAST MAINLY BETWEEN 06Z AND 12Z AS THE OCCLUDED FRONT PUSHES THROUGH, WITH GRADUALLY IMPROVING CONDITIONS SUNDAY. && .OHX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM CST SUNDAY FOR HOUSTON- MONTGOMERY-ROBERTSON-STEWART. && $$ SHORT TERM/AVIATION........08 LONG TERM..................17
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1052 PM CST SAT JAN 9 2016 .AVIATION... /06Z TAFS/ VFR CONDITIONS ARE EXPECTED FOR AREA TERMINALS THROUGH THE FORECAST PERIOD. STRATUS CLOUDS OVER THE NORTHEAST HILL COUNTRY ASSOCIATED WITH WRAP A AROUND MOISTURE FROM THE LOW PRESSURE OVER THE OHIO VALLEY IS EXPECTED TO PUSH TO THE EAST WITHIN THE NEXT FEW HOURS. DONT ANTICIPATE CIGS ISSUE AT KAUS. OTHERWISE...NORTHERLY WINDS 7 TO 10 KNOTS ARE EXPECTED THROUGH SUNDAY MORNING WITH LIGHT AND VARIABLE WINDS OVER KDRT. A SURFACE HIGH PRESSURE RIDGE IS FORECAST TO MOVE OVER THE ARKLATEX SUNDAY AFTERNOON WITH WINDS VEERING WITH A RETURN SOUTHERLY FLOW EXPECTED ACROSS THE RIO GRANDE AND SOUTHERN EDWARDS PLATEAU AND THEN OVER THE EASTERN HALF OF SOUTH CENTRAL TEXAS SUNDAY EVENING. && .PREV DISCUSSION... /ISSUED 738 PM CST SAT JAN 9 2016/ UPDATE... CURRENT FORECAST IS IN GOOD SHAPE REGARDING THE EXPECTED LOW TEMPERATURES. LATEST HRRR GUIDANCE REMAINS CONSISTENT WITH OUR OFFICIAL FORECAST AND NOT EXPECTING ANY NEED FOR A FREEZE WARNING FOR COUNTIES WHICH HAVE NOT RECEIVED A FREEZE SO FAR THIS WINTER. ONLY MADE SOME MINOR ADJUSTMENTS TO THE HOURLY GRIDS BASED ON CURRENT TRENDS. PREV DISCUSSION... /ISSUED 530 PM CST SAT JAN 9 2016/ AVIATION... /00Z TAFS/ VFR CONDITIONS WILL PREVAIL ACROSS AREA TERMINALS THROUGH THE FORECAST PERIOD. NORTHERLY WINDS ARE EXPECTED TO PERSIST ACROSS SOUTH CENTRAL TEXAS THROUGH SUNDAY AS SURFACE HIGH PRESSURE RIDGE OVER THE SOUTHERN PLAINS MOVES TO THE SOUTHEAST AND INTO THE OKLAHOMA AREA BY SUNDAY AFTERNOON. WIND SPEEDS WILL RANGE FROM 8 TO 12 KNOTS WITH GUSTS UP TO 22 KNOTS THROUGH 01Z SUNDAY...ESPECIALLY ACROSS KAUS. WIND WILL RELAX A BIT OVERNIGHT ALONG THE I-35 CORRIDOR AND LIGHT AND VARIABLE OUT WEST ACROSS KDRT. SURFACE HIGH PRESSURE RIDGE IS FORECAST TO MOVE OVER THE ARKLATEX SUNDAY AFTERNOON WITH WINDS VEERING WITH A RETURN SOUTHERLY FLOW EXPECTED ACROSS THE RIO GRANDE AND SOUTHERN EDWARDS PLATEAU. PREV DISCUSSION... /ISSUED 303 PM CST SAT JAN 9 2016/ SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)... THE FOCUS OF THE SHORT TERM WAS ON THE BREEZY WINDS OUT OF THE NORTHWEST THIS AFTERNOON AND LOW TEMPERATURES TONIGHT AND SUNDAY NIGHT. THE SURFACE PRESSURE GRADIENT SHOULD RELAX OVER THE NEXT 6 HOURS AS HIGH PRESSURE SHIFTS EASTWARD FROM THE TEXAS PANHANDLE INTO THE RED RIVER VALLEY. THE AXIS OF HIGH SURFACE PRESSURE WILL SHIFT EAST AND WITH IT...WINDS WILL DIE DOWN WEST OF THE I35 CORRIDOR AND SHIFT TO A MORE DUE NORTH AND NORTHEAST DIRECTION. HOWEVER...EAST OF THE 35 CORRIDOR THE GRADIENT WILL MAINTAIN WINDS A BIT MORE AND ALLOW FOR 5-15 MPH. FOR TEMPERATURES...THE QUESTION IS HOW FAR SOUTH FREEZING TEMPERATURES WILL REACH. WITH THE WEAKER WINDS OUT WEST...THERE IS SOME POTENTIAL FOR THE FREEZING LINE TO SPREAD FARTHER SOUTH INTO THE RIO GRANDE PLAINS...POSSIBLY JUST SOUTH OF THE EDWARDS ESCARPMENT. SIMILAR PATTERNS HAVE HAD TROUBLE WITH THE FREEZING TEMPERATURES COMING OFF THE TOPOGRAPHY OF THE PLATEAU THOUGH AND THINK THERE ISNT ENOUGH MOMENTUM OF THE HIGH DENSITY AIR TO BE MUCH DIFFERENT THAN BEFORE. WILL NEED TO WATCH THIS CLOSELY THOUGH AS THIS WILL HAVE FREEZE WARNING IMPLICATIONS FOR SOME COUNTIES IN OUR SOUTH AND SOUTHWEST. LONG TERM (MONDAY THROUGH SATURDAY)... COOL AND DRY CONDITIONS WILL PERSIST THROUGH MONDAY. MONDAY NIGHT...ANOTHER PROGRESSIVE SHORTWAVE WILL PASS OVER THE STATE BUT BEST MOISTURE SEEMS TO BE CONFINED TO THE GULF COAST. SO...WE SHOULD AVOID POPS UNTIL OUR NEXT UPPER LEVEL SYSTEM PROGGED TO BEGIN IMPACTING THE STATE LATE WEDNESDAY. SHOULD BE ENOUGH OF A REBOUND IN H5 HEIGHTS TO WARM THINGS UP WEDNESDAY INTO THE 60S. THE UPPER LOW WILL DIVE MUCH FARTHER SOUTH THAN ITS PREVIOUS BRETHREN AND PASS THROUGH THE BIG BEND REGION ENTERING SOUTH CENTRAL TEXAS FROM THE RIO GRANDE PLAINS. THE SERIES OF LOWS HAS PROHIBITED PROLONGED SURFACE MOISTURE RETURN MUCH FARTHER NORTH AND WEST THAN THE COASTAL PLAINS AND AREAS EAST OF THE I35 CORRIDOR. SIMILARLY...THESE AREAS LOOK LIKE THE BEST SHOT AT POPS. THE BEST DYNAMIC INFLUENCE WEDNESDAY NIGHT INTO THURSDAY MORNING SHOULD PRODUCE DECENT RAINFALL BUT SHOULDNT BE A PROLONGED EVENT AS MODELS PUSH THIS LOW EAST QUICKLY. AFTERWARDS...A BRIEF ZONAL FLOW PATTERN WILL PREVAIL UNTIL THURSDAY AS THE NEXT SHORTWAVE BRINGS POP CHANCES NEXT WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 33 50 31 51 38 / 0 0 - - - AUSTIN BERGSTROM INTL AIRPORT 32 50 29 51 34 / 0 0 - - - NEW BRAUNFELS MUNI AIRPORT 32 52 30 52 36 / 0 0 - 10 - BURNET MUNI AIRPORT 30 47 29 50 35 / 0 0 - - 0 DEL RIO INTL AIRPORT 33 55 36 53 36 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 30 48 28 50 35 / 0 0 - - 0 HONDO MUNI AIRPORT 31 54 31 52 34 / 0 0 0 - - SAN MARCOS MUNI AIRPORT 32 51 30 51 37 / 0 0 - 10 - LA GRANGE - FAYETTE REGIONAL 33 50 31 53 40 / 0 0 - 10 10 SAN ANTONIO INTL AIRPORT 33 52 32 52 38 / 0 0 0 - - STINSON MUNI AIRPORT 34 53 32 52 38 / 0 0 0 - - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...17 SYNOPTIC/GRIDS...HAMPSHIRE PUBLIC SERVICE/DATA COLLECTION...TREADWAY
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AREA FORECAST DISCUSSION
NWS SEATTLE WA
910 PM PST SAT JAN 9 2016 .SYNOPSIS....A WEAK FRONT WILL DISSIPATE OVER THE SOUTH INTERIOR TONIGHT. HIGH PRESSURE WILL BUILD OVER THE PACIFIC NORTHWEST LATE TONIGHT AND SUNDAY GIVING MOSTLY DRY WEATHER. A WEAK WEATHER SYSTEM WILL AFFECT THE REGION MONDAY AND TUESDAY WITH SPOTTY LIGHT AT TIMES. A SOMEWHAT STRONGER SYSTEM WITH MORE WIDESPREAD RAIN WILL AFFECT THE AREA LATE TUESDAY AND WEDNESDAY. DRIER WEATHER MAY DEVELOP THE END OF NEXT WEEK. && .SHORT TERM...AS EXPECTED 24 HOURS AGO...THE OFFSHORE LOW SPLIT WITH UPPER LEVEL ENERGY DROPPING SE THROUGH OREGON AND NOW NI NORTHERN CALIFORNIA. THE LOW LEVEL CENTER OVER THE COASTAL WATERS IS GRADUALLY LOSING ITS IDENTITY WITH CLOUD TOPS FROM THE OLD LOW CENTER SE THROUGH THE SW INTERIOR OF W WA GRADUALLY WARMING. KATX AND KLGX RADARS DO SHOW SOME VERY LIGHT RAIN OR DRIZZLE SITTING FROM AROUND SHELTON SE THROUGH OLYMPIA. ECHOS ARE WEAKENING AND SHOULD DISSIPATE OVER THE NEXT COUPLE OF HOURS. SOME FOG IS SEEN OVER THE INTERIOR FROM OLYMPIA TO SHELTON. THE LATEST HRRR SOLUTIONS SHOW THE AREA OF FOG OVER THE SOUTH INTERIOR EXPANDING NWD TO THE KITSAP PENINSULA AND OVER PUGET SOUND WITH A COUPLE OF PATCHES FROM SEATTLE DOWN TO TACOMA THROUGH SUNDAY MORNING. THE FOG IS EXPECTED TO LIFT AND SCATTER OUT BY MIDDAY SUNDAY AS LOW LEVEL FLOW BECOMES MORE EASTERLY AND AN UPPER LEVEL RIDGE BUILDS OVER THE REGION. WITH SOME CLEARING SUNDAY AFTERNOON...HIGH TEMPERATURES IN THE CENTRAL PUGET SOUND AREA ARE EXPECTED TO BE A COUPLE OF DEGREES HIGHER THAN EARLIER THOUGHT...THE MID TO UPPER 40S. THE NEXT SPLITTING FRONTAL SYSTEM WILL ARRIVE MONDAY MORNING ALONG THE COAST THEN SPREAD NE INTO THE INTERIOR DURING THE AFTERNOON HOURS. THIS TIMING IS SIMILAR TO PREVIOUS MODEL SOLUTIONS AND TO THE GOING FORECAST. MODELS NOW SHOW LITTLE IN THE WAY OF A BREAK BETWEEN TUESDAYS SPLITTING SYSTEM AND ANOTHER COMING IN FOR TUESDAY NIGHT INTO WEDNESDAY. AN UPDATE TO RAISE HIGH TEMPERATURES IN THE SEATTLE-EVERETT-TACOMA METRO AREA ABOUT 2 DEG WAS ISSUED THIS EVENING. OTHERWISE THE GOING FORECAST LOOKS GOOD FOR NOW. ALBRECHT .LONG TERM...FROM THE PREVIOUS LONG TERM DISCUSSION...SPOTTY LIGHT RAIN OR SHOWERS LINGER LATE WEDNESDAY INTO EARLY THURSDAY... ESPECIALLY OVER THE CASCADES. THE LOWLANDS SHOULD BEGIN TO DRY OUT BUT MODELS ARE NOT IN VERY GOOD AGREEMENT AND POPS WILL REMAIN LIMITED TO CASCADES THURSDAY. FRIDAY AND FRIDAY NIGHT STILL LOOK DRY AS A STRONG RIDGE TRAVERSES THE REGION. EXPECT LATE NIGHT AND MORNING FOG AROUND THE LOWLANDS AROUND PUGET SOUND AND THE SW INTERIOR. THE NEXT SERIES OF FRONTAL SYSTEMS ARRIVE NEXT WEEKEND WITH A CHANCE OF RAIN OVER THE AREA. SOME MODELS HINT THAT A MORE ACTIVE PATTERN COULD DEVELOP. MERCER && .AVIATION...AN UPPER RIDGE AXIS WILL MOVE ACROSS WRN WA ON SUNDAY AND STRENGTHEN A BIT. THIS WILL HELP TO DRY OUT THE AIR MASS A BIT BY SUNDAY AFTN. LIGHT SOUTHERLY FLOW ALOFT FOR NEXT 24 HOURS. CURRENTLY...MANY SITES OVER WRN WA REPORTING BKN-OVC CIGS OF 030- 050. THESE CLOUD LAYERS WILL SLOWLY BECOME THINNER OVERNIGHT...WITH DISSIPATION LIKELY ON SUNDAY MORNING. FOG HAS BEEN LIMITED SO FAR THIS EVNG DUE TO INHIBITING EFFECT OF THESE CLOUDS...BUT EXPECT SOME FOG TO FILL IN OVER THE SW INTERIOR AND SOUTH SOUND AROUND SUNRISE AS THE CLOUDS ABOVE START SCATTERING OUT. KSEA...CIGS AROUND 040 WILL THIN AND START TO SCATTER OUT LATE TONIGHT. CAUTIOUSLY OPTIMISTIC THAT THESE CLOUDS WILL PERSIST LONG ENOUGH TO PREVENT FOG DEVELOPMENT AT THE TERMINAL ON SUNDAY MORNING. BY 18Z...CLOUDS ABOVE WILL HAVE DISSIPATED...WITH CLEAR SKIES EXPECTED ON SUNDAY AFTN AND SUNDAY NIGHT. INCREASING EASTERLY FLOW...A DRYING DIRECTION...WILL BE INCREASING ON SUNDAY NIGHT AND SHOULD PREVENT FOG FORMATION AT KSEA ON MONDAY MORNING. HANER && .MARINE...A WEAK FRONT AND LOW PRESSURE AREA WILL DISSIPATE LATER TONIGHT AS IT MOVES NORTH THROUGH THE OUTER COASTAL WATERS. A 1003 MB LOW WILL MOVE DUE NORTH ALONG 130W ON MON MORNING...THEN A WEAKENING FRONT WILL MOVE NE ACROSS THE WATERS ON MON EVENING. A STRONGER LOW WILL LIFT DUE NORTH ALONG 130W ON TUE NIGHT...WITH A TRAILING COLD FRONT CROSSING THE WATERS ON WED. UNTIL THE COLD FRONT ON WED...THIS WILL SPELL VARYING AMOUNTS OF SE WIND. OTHERWISE...THE UPTICK IN SWELL HEIGHT OVER THE PAST FEW HOURS SHOULD PEAK IN THE NEXT COUPLE OF HOURS...THEN SUBSIDE BELOW 10 FT AROUND MID-DAY SUNDAY. THE NEXT LULL IN SWELL HEIGHT WILL COME SUNDAY NIGHT...FOLLOWED BY THE NEXT PEAK ON MON NIGHT.HANER && .HYDROLOGY...RIVER FLOODING IS NOT EXPECTED FOR THE NEXT 7 DAYS. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...NONE. PZ...SMALL CRAFT ADVISORY UNTIL 9 AM PST SUNDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM- COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM-WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 9 AM PST SUNDAY FOR GRAYS HARBOR BAR. $$ && WWW.WEATHER.GOV/SEATTLE YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS MIAMI FL
140 AM EST TUE JAN 12 2016 .AVIATION... AREAS OF LIGHT RAIN WILL AFFECT THE SE FL TERMINALS THROUGH MORNING AND POSSIBLY INTO EARLY AFTERNOON BEFORE CONDITIONS IMPROVE FROM WEST TO EAST. VFR IS STILL EXPECTED TO PREVAIL, BUT BRIEF MVFR CIGS IS POSSIBLE. WINDS WILL PREVAIL OUT OF THE NW AT 5-10 KT. /GREGORIA && .PREV DISCUSSION... /ISSUED 1052 PM EST MON JAN 11 2016/ UPDATE 2... QUICK UPDATE TO RAISE POPS TO A LITTLE BIT OVER THE SOUTHERN AREAS OF SOUTH FLORIDA FOR REST OF TONIGHT...AS THE LATEST SHORT RANGE MODELS ARE SHOWING THE RAINS TO CONTINUE THROUGH THE OVERNIGHT HOURS ESPECIALLY SOUTH OF ALLIGATOR ALLEY. UPDATE...54/BNB PREV DISCUSSION... /ISSUED 702 PM EST MON JAN 11 2016/ UPDATE... LATEST HRRR AND LOCAL MODELS IN GOOD AGREEMENT NOW, SPREADING MORE NUMEROUS SHOWERS ACROSS MAINLAND MONROE/MIAMI-DADE COUNTIES A FEW HRS FASTER. THUS, INC POPS A BIT FOR TONIGHT AND TOMORROW MORNING. PREV DISCUSSION... /ISSUED 657 PM EST MON JAN 11 2016/ AVIATION... BOUNDARY MOISTURE ACROSS THE FLORIDA STRAITS IS EXPECTED TO CONTINUE LIFTING NORTHWARD THIS EVENING AND OVER NIGHT. WITH NORTH TO NORTH NORTHWESTERLY SURFACE WINDS ACROSS THE REGION..THIS WILL RESULT IN OVER-RUNNING ACROSS THE BOUNDARY WITH A CHANCE OF LIGHT SHOWERS AFFECTING THE TERMINALS FROM TIME TO TIME. WHILE VFR CONDITIONS WILL PREVAIL...BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE WITH OCCURRENCE OF SHOWERS AND OCCASIONAL LOWERING OF THE STRATOCUMULUS THAT WILL KEEP STREAMING ACROSS THE REGION. WIND FORECAST IS A CHALLENGE IN THAT WINDS ARE EXPECTED TO OSCILLATE BETWEEN NORTH NORTHWEST AND NORTH NORTHEAST THIS EVENING THROUGH THE EARLY MORNING HOURS ON TUESDAY. 60 PREV DISCUSSION... /ISSUED 415 PM EST MON JAN 11 2016/ SHORT TERM (TONIGHT-WED NIGHT)... INTO TONIGHT, AS A WEAK DISTURBANCE RIDES SW TO NE FROM CUBA TO THE BAHAMAS, ALONG THE STALLED BOUNDARY, MOISTURE WILL GRADUALLY INCREASE. SUBTLE OVERRUNNING/ISENTROPIC LIFT MAY SHOVE SOME SHOWERS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA LATE TONIGHT. THE ECMWF CONTINUES TO BE WETTER AND MORE AGGRESSIVE INTO TUESDAY, THAN THE REST OF THE MODEL SUITE. 15Z SREF 3HR PRECIP PROBS SEEM TO MATCH THE 12Z GFS DEPICTION FAIRLY WELL WITH MORE PERSISTENT SHOWERS SHIFTED SOUTH. BLENDED POPS HAVE BEGUN TO SHIFT TOWARDS THIS CONSENSUS, BUT CONFIDENCE REGARDING HOW FAR NORTH THE PERSISTENT SHOWERS REACH IS BELOW AVG. HIGH CHC POPS ARE IN THE FORECAST FOR THE SOUTHERN QUARTER OF THE CWA DURING THE FIRST HALF OF TOMORROW. ANOTHER SHOT OF COOLER AND DRIER AIR ARRIVES TUESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN STATES BEHIND ANOTHER STRONG COLD FRONT THROUGH THE MIDDLE ATLANTIC. MIN TEMPS ARE FORECASTED INTO THE MIDDLE 40S ACROSS THE INTERIOR NORTHWEST. MIDDLE TO UPPER 50S ARE POSSIBLE EVEN INTO CITIES OF EXTREME SE FL. SURFACE HIGH PRESSURE CENTERED OVER NORTHERN FL FOR MUCH OF WEDNESDAY PROVIDES ANOTHER DRY DAY WITH MAX T AROUND 70F FOR MUCH OF THE REGION. ALTHOUGH SOME CLOUDS ARE EXPECTED TO ARRIVE WEDNESDAY NIGHT AS HIGH PRESSURE SLOWLY SLIPS EAST, TEMPS COULD BE COOLER THAN FORECAST IF MOISTURE RETURN IS SLOWER. LONG TERM (THU-SUN NIGHT)... DEVELOPMENT AND MOVEMENT OF LOW PRESSURE ACROSS THE GULF OF MEXICO, WHICH EVENTUALLY IMPACTS FL, IS SLOWER THAN PREVIOUS MODEL CYCLES. THUS, PRECIP HAS BEEN DELAYED SOMEWHAT INTO THURSDAY. THE GFS IS MUCH FASTER, IN CONTRAST TO THE 12Z ECMWF WHICH HAS LITTLE IF ANY PRECIP BETWEEN 12Z THURS-0Z FRIDAY. MADE SOME ADJUSTMENTS TO THE POP BLENDS FOR THIS DAY CONSIDERING. THERE SEEMS TO BE BETTER AGREEMENT ON LATE THURS NIGHT/FRIDAY BEING THE DAY IN WHICH LOW PRESSURE AND A WARM FRONT CROSSES THE WEST COAST OF FL, WHICH COULD RESULT IN SHOWERS AND THUNDERSTORMS INCOMING FORM THE GULF. WATCHING THE OPERATIONAL GFS OVER THE PAST FEW DAYS, IT DOES SEEM TO BE SUFFERING FROM CONVECTIVE FEEDBACK/QPF BULLSEYES, WHICH PUTS INTO QUESTION ITS EVENTUAL TRACK/PLACEMENT/STRENGTH OF LOW PRESSURE. THE ECMWF HAS BEEN SHIFTING SOME OF THE STRONGER FEATURES NORTH. HOWEVER, THE PRESENCE OF A STRONG UPPER JET STREAK CUTTING THROUGH THE GULF ALONG WITH FORECASTED WIND FIELDS CANNOT BE IGNORED. THIS SETUP FOR A FEW STRONGER THUNDERSTORMS REMAINS SOMETHING TO KEEP AN EYE FOR ALL OF SOUTH FL AT THE END OF THE WORK WEEK. A COLD FRONT CROSSING SOUTH FL LATE WEEKEND COULD DELIVER ANOTHER COOLER/DRIER AIRMASS IN TIME FOR EARLY NEXT WEEK. MARINE... A SMALL NORTHEAST SWELL WILL CONTINUE TO AFFECT THE WATERS OFF OF PALM BEACH COUNTY OVER THE NEXT FEW DAYS. MOISTURE RETURNING TO THE REGION MAY PUSH SOME SHOWERS THROUGH THE ATLANTIC WATERS OFF OF MIAMI-DADE LATER TONIGHT AND TOMORROW. NORTHERLY WINDS INCREASE TO AROUND 15 KTS AGAIN TOMORROW NIGHT, WHICH WILL ALSO ALLOW SOME WAVES NEAR 6 FT ALONG THE GULF STREAM INTO WEDNESDAY, ESPECIALLY OFF PALM BEACH COUNTY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 50 71 56 73 / 0 10 0 20 FORT LAUDERDALE 54 71 59 72 / 0 10 10 30 MIAMI 54 73 59 73 / 10 10 10 30 NAPLES 48 70 53 73 / 0 0 0 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
244 AM CST TUE JAN 12 2016 .SHORT TERM...(Today) ISSUED AT 244 AM CST TUE JAN 12 2016 Latest surface analysis indicating another surge of Arctic air poised just to our northwest with the strong cold front located near Dubuque southwest to near Ottumwa tracking quickly to the southeast. Impressive 3 hourly pressure rises to the west of the front over central Iowa as of 08z helping to produce 35 to 45 mph wind gusts as the Arctic air surges southeast. Along with the gusty winds, a quick moving band of snow showers was tracking into west central Illinois with visibilities briefly lowering to around one mile in a few locations. The snow showers should accumulate less than an inch but blow around for a time this morning before the strong pressure rises shift off to our east in the 15z-18z time frame. Temperatures will then nose dive this morning with readings in central Iowa already down to near zero. The combination of the very cold air and gusty winds will bring wind chills down to 5 below to 10 below zero across the north and areas to the east and southeast should see wind chills drop into the single digits above zero this morning. Most areas are already at their high temperatures for today, and except for far southeast Illinois, most locations should see temperatures fall off quickly during the morning hours with little in the way of a temperature rise this afternoon. Looks as if afternoon temperatures will range from around 10 above north to near 20 far southeast with wind chills around 5 above zero far southeast to as cold as 8 below across the north. && .LONG TERM...(Tonight through Monday) ISSUED AT 244 AM CST TUE JAN 12 2016 One of the colder nights of the season is on tap for tonight as Arctic high pressure shifts through. Given upstream airmass and allowing for some modification lows should primarily be in the single digits. Temperatures will begin to moderate on Wednesday as southerly return flow sets up, in response to the next weak clipper passing through the upper Midwest. This system will have mid/upper support but be moisture starved. With the surface reflection weakening as it passes north of the CWA, would expect scattered snow showers mainly north of I-74 with little to no accumulation. Thursday will see a quick transition to zonal flow aloft which will allow a thermal ridge over the Plains to shift east. This should boost temperatures several degrees above normal, in the low to mid 40s. The mild trend will continue into Friday as the next mid level trough and surface front shift across the Midwest. This will bring a good chance of rain showers to the region. The precip may briefly change over to light snow Friday night as colder air filters in on the back side of the low. Cyclonic flow and lingering moisture could bring some snow showers, mainly to the eastern CWA, on Saturday. Medium range models are in good agreement that Arctic air will return to the region for Sunday and Monday, when strong high pressure builds SE from Canada into the Plains. There is also agreement that some light snow will be possible on the leading edge of the Arctic surge, but with low confidence on timing will keep pops to slight chance. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1151 PM CST MON JAN 11 2016 Arctic cold front currently across central Iowa will sweep southeastward tonight, bringing a period of light snow followed by windy and sharply colder conditions. HRRR continues to perform quite well, so will rely heavily upon its forecast which features snow arriving at KPIA by 08z...then further east to KCMI by 10z. Based on satellite timing tools and HRRR...have carried a 3-4 hour period of snow. Once the front passes...the snow will come to an end and westerly winds will veer to the northwest. FROPA appears to be on target at KPIA by 11z...then to KCMI by around 13z. Forecast soundings and numeric guidance suggest gusts in the 25 to 30kt range behind the front late tonight into Tuesday morning. The winds will gradually diminish and back to the W/SW by Tuesday evening. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Smith LONG TERM...25 AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1151 PM CST MON JAN 11 2016 .UPDATE... ISSUED AT 634 PM CST MON JAN 11 2016 Initial short-wave trough is currently passing through north-central Illinois early this evening, with the bulk of the associated precip remaining north of the KILX CWA. While radar is showing light echoes along/east of the I-55 corridor, only a few flurries have been observed thus far. A second more vigorous wave is noted on 00z/6pm water vapor imagery upstream over Minnesota, and think this will be the main snow-maker later tonight. HRRR seems to have a great handle on the situation, so have followed its solution closely. As such, have removed PoPs entire through the evening, opting instead to go with just scattered flurries. Then will bring a period of snow across the area from west to east after midnight as the next wave and associated cold front arrive. Some of this light snow will likely linger into Tuesday morning along/south of I-70. Due to the light nature of the snow and only a 3-4 hour window when snow will be falling, overnight accumulations will remain quite light. Most areas will only see one half inch or less. Main story will be the windy and sharply colder conditions late tonight, as lows drop into the teens and wind-chill readings dip below zero along/north of I-72 toward dawn Tuesday. && .SHORT TERM...(Tonight) ISSUED AT 256 PM CST MON JAN 11 2016 One short wave moving into central MO and eastern IA at mid afternoon will pivot eastward across central IL by early this evening. A stronger northern stream short wave over western MN will dive southeast into northeast IL, northern IN and lower MI by dawn Tue and drive an arctic cold front se across central IL overnight as 1012 mb surface low pressure over ne Iowa deepens to 1000 mb over far eastern lower MI by 12Z/6 am Tue. Brunt of lift and moisture will pass ne of central IL with our area on sw fringe of this deepening storm system. Expect light snow to likely develop and move from nw IL into central IL late this afternoon or evening and then diminish from the west late tonight/early Tue morning, lingering longest over Wabash river valley Tue morning. Snowfall amounts generally around a half inch using a 15-20:1 ratio while areas northeast of I-74 and near the IN border could see half to 1 inch. Lows to be reached Tue morning to range from 10F at Galesburg to 25F at Lawrenceville. Brisk WNW winds of 15-25 mph behind arctic cold front overnight to lower wind chills to zero to 10 below zero from I-72 north late tonight into Tue morning. .LONG TERM...(Tuesday through Monday) ISSUED AT 256 PM CST MON JAN 11 2016 Very chilly conditions are anticipated across central and southeast Illinois into Wednesday in the wake of tonight`s clipper. While the clipper should be mostly east of the area to start the day Tuesday, a few lingering snow showers are possible in far east-central and southeast Illinois. Temperatures on Tuesday will not make it into the 20s across much of the forecast area, and widespread single digit or just below zero overnight lows are likely Tuesday night. Wind Chill values through this period should be single digit or sub- zero more often than not. The upper wave associated with the departing clipper will lift into New England and far eastern Canada by Wednesday. As it departs, the upper-level flow across the forecast area will initially trend more zonal, and eventually southwesterly by Thursday and Friday. This shift in the mean flow will allow temperatures to trend above normal by Thursday and Friday, as troffing reloads across central North America. A system is expected to track into the Midwest within this developing southwesterly flow by late Thursday night into Friday. Consensus now strongly suggests temperatures will moderate enough ahead of this system for the bulk of its associated precipitation to fall in the form of rain. Behind this system the model agreement is less substantial, and confidence in the specific details is low. However, temperatures should plunge below normal once again behind the system, with any remaining precipitation falling as snow. While the trend for the weekend will definitely be colder, how cold it gets and how long the cold lasts is still up for significant debate. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1151 PM CST MON JAN 11 2016 Arctic cold front currently across central Iowa will sweep southeastward tonight, bringing a period of light snow followed by windy and sharply colder conditions. HRRR continues to perform quite well, so will rely heavily upon its forecast which features snow arriving at KPIA by 08z...then further east to KCMI by 10z. Based on satellite timing tools and HRRR...have carried a 3-4 hour period of snow. Once the front passes...the snow will come to an end and westerly winds will veer to the northwest. FROPA appears to be on target at KPIA by 11z...then to KCMI by around 13z. Forecast soundings and numeric guidance suggest gusts in the 25 to 30kt range behind the front late tonight into Tuesday morning. The winds will gradually diminish and back to the W/SW by Tuesday evening. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Barnes SHORT TERM...07 LONG TERM...BAK AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS JACKSON KY
259 AM EST TUE JAN 12 2016 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 07Z SFC ANALYSIS SHOWS A DEEPENING AREA OF LOW PRESSURE MOVING THROUGH THE CENTRAL GREAT LAKES. THIS IS DRIVING AN ARCTIC COLD FRONT INTO THE NORTHWEST PORTION OF THE OHIO VALLEY EARLY THIS MORNING. CLOSER TO HOME...A DECENT PRESSURE GRADIENT EXISTS OVER KENTUCKY BETWEEN THE LOW TO THE NORTH AND HIGH PRESSURE ALONG THE GULF COAST. THIS IS ALREADY MANIFESTING IN SOME BREEZY SOUTHWEST WINDS THROUGH THE BLUEGRASS HELPING TO KEEP NIGHTTIME TEMPERATURES RELATIVELY MILD FOR MUCH OF THE AREA. WHILE MOST PLACES ARE SEEING LOW AND MID 30S FOR THE JKL CWA...A FEW SHELTERED EASTERN VALLEYS REMAIN IN THE MID 20S. WINDS ARE GUSTING OVER THE WESTERN PARTS OF THE AREA REACHING THE 25 TO 30 MPH RANGE AT TIMES. ALTHOUGH A DRY AIR MASS IS IN PLACE THE SOUTHERLY WINDS WILL TRY TO BRING IN MORE MOISTURE THROUGH THE FIRST PART OF THE MORNING AHEAD OF THE ARCTIC FRONT. MEANWHILE...DEWPOINTS THROUGHOUT THE AREA ARE RUNNING IN THE UPPER SINGLE DIGITS TO MID TEENS NORTHEAST TO THE MIDDLE AND UPPER TEENS SOUTH. A DECK OF MID LEVEL CLOUDS COVER THE BULK OF EASTERN KENTUCKY WITH EVEN A FEW VERY LIGHT SNOW SHOWERS AND FLURRIES PASSING THROUGH. THE MODELS ARE IN EXCELLENT AGREEMENT WITH THE UPPER AIR PATTERN THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE CORE OF A FAIRLY DEEP TROUGH...THAT IS MOVING INTO THE OHIO VALLEY...TO PUNCH THROUGH KENTUCKY BY EARLY AFTERNOON. THIS IS DRIVEN BY A 135 TO 140 KT 300 MB JET ARCING INTO THE REGION THIS MORNING WITH A GOOD AMOUNT A UPPER LEVEL DIVERGENCE PROGGED TO PASS OVER EAST KENTUCKY BETWEEN 09 AND 21Z. IT WILL BE A QUICK HITTING MID LEVEL WAVE...THOUGH...AS BY 00Z IT WILL BE OFF THE MID ATLANTIC COAST ALLOWING HEIGHTS TO RELAX LOCALLY AND RISE INTO THE DAY WEDNESDAY. A COUPLE OF WEAKER WAVES DO FOLLOW IN NORTHWEST FLOW AND LOOK TO PASS ABOVE EAST KENTUCKY FOR WEDNESDAY. GIVEN THE GOOD MODEL MATCH-UP WILL FOLLOW SUIT BUT FAVOR THE SPECIFICS FROM THE HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS... ALONG WITH A HEALTHY DOSE OF CLIMATOLOGY FOR THESE SITUATIONS IN EASTERN KENTUCKY. SENSIBLE WEATHER WILL FEATURE A DYNAMIC AND ACTIVE WEATHER DAY AS AN ARCTIC BOUNDARY PASSES THROUGH THE CWA BY LATE IN THE AFTERNOON. WHILE LIGHT SNOW WILL BE POSSIBLE AHEAD OF THIS BOUNDARY...THE MAIN SHOW WILL BE JUST ALONG AND BEHIND IT AS IT HELPS TO MAXIMIZE THE MID LEVEL LAPSE RATES AND FIND JUST ENOUGH CAPE TO BECOME CONVECTIVE IN NATURE. GIVEN THE BACKGROUND PRESSURE AND HEIGHT GRADIENTS IN THE THE LOWER LEVELS OF THE ATMOSPHERE THE HIGHER WINDS ALOFT SHOULD BE ABLE TO BE TAPPED BY THE CONVECTIVE CELLS LEADING TO GUSTY WINDS AT THE SFC. THIS COMBINED WITH THE SNOW SHOWERS WILL MEAN RAPIDLY CHANGING VISIBILITY IN GUSTY SNOW SQUALLS. FINALLY...GIVEN THE COLD STARTING POINT FOR ROAD SFCS... EXPECT ANY SNOW THAT FALLS TO POTENTIALLY ACCUMULATE ON THE ROADS...WITH LIMITED HELP FROM INSOLATION DURING THE DAYLIGHT HOURS. SO...ALTHOUGH QPF WILL BE RATHER LIMITED WITH THIS FRONT... THE IMPACT FROM THESE LIGHT EVENTS CAN BE AS LARGER OR LARGER THAN BIGGER WINTER STORMS SO WILL CONTINUE TO HIT IT HARD WITH A WSW ADVISORY ACROSS THE BULK OF OUR CWA TODAY...STARTING EARLIER IN THE WEST AND LINGERING LONGER IN THE EAST. SNOW AMOUNTS SHOULD BE MAXIMIZED...WITH A POTENTIAL FOR UP TO 2 INCHES...IN THE NORTHERN PARTS OF THE CWA AND IN THE HIGHEST TERRAIN NEAR THE VIRGINIA BORDER. THE SNOW WILL END FROM WEST TO EAST IN THE EVENING...WITH A DROP OFF IN THE SQUALLINESS AFTER SUNSET. LOOK FOR A HINT OF UPSLOPE COMPONENT INTO THE NIGHT TO KEEP A SMALL THREAT OF SNOW SHOWERS AND FLURRIES GOING IN THE FAR EAST THROUGH EARLY WEDNESDAY MORNING...BUT ANY ADDITIONAL ACCUMULATIONS WILL BE MARGINAL AFTER THIS EVENING. CHILLY HIGH PRESSURE THEN SPREADS INTO THE STATE WITH LOW TEMPERATURES NEARING THE SINGLE DIGITS IN THE NORTHWEST BY DAWN WEDNESDAY. WINDS STILL BRISK WILL YIELD WIND CHILLS DOWN NEAR ZERO IN SPOTS AND MAINLY SINGLE DIGITS ELSEWHERE AT DAWN WEDNESDAY. READING WILL THEN STRUGGLE TO RISE OUT OF THE 20S ON WEDNESDAY DESPITE A RETURN OF SOME SUNSHINE. IN FACT...THE SUNSHINE WILL LIKELY BE LIMITED BY SOME MID AND HIGH LEVEL CLOUDS INBOUND FROM THAT NEXT...WEAKER...WAVE PASSING BY AT MID LEVELS. ACCORDINGLY...HAVE NOT ZEROED OUT POPS FOR LATER WEDNESDAY AS A COUPLE OF FLURRIES CANNOT BE RULED OUT FROM THIS FEATURE WHEN IT BRUSHES BY FROM WEDNESDAY AFTERNOON INTO THE EVENING. USE THE SHORTBLEND AS A STARTING POINT FOR TEMPERATURES AND DEWPOINTS THROUGH THE EVENING WITH THE SUPERBLEND USED THEREAFTER. MADE ONLY MINOR ADJUSTMENTS FOR SOME TERRAIN DISTINCTIONS TONIGHT...AS THE GRIDS LOOKED REASONABLE. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF THE MOS...WHICH IS TYPICAL FOR THIS TYPE OF SITUATION. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 PERIOD WILL BEGIN WITH A MID LEVEL TROUGH MOVING ACROSS THE OHIO VALLEY WEDNESDAY NIGHT...WHILE PRECIP WILL BE POSSIBLE NORTH OF THE REGION ACROSS CENTRAL OH. WE WILL MAINLY SEE CLOUDS ASSOCIATED WITH THIS WAVE WEDNESDAY NIGHT HERE IN EASTERN KY. ON THURSDAY HIGH WILL BE PARKED TO THE SE AND WILL INTRODUCE RETURN FLOW TO THE REGION. THIS WILL ALLOW TEMPS TO MODERATE THROUGH THE END OF THE WEEK. TEMPS ON THURSDAY WILL SOAR INTO THE UPPER 40S TO LOWER 50S...AND THIS WILL FEEL PLEASANT GIVEN ANTECEDENT TEMPS. OVERALL UPPER LEVEL FLOW WILL FLATTEN AHEAD OF A DEEPENING TROUGH ACROSS THE PLAINS. THIS AFOREMENTIONED DEEPENING TROUGH WILL SWING EAST AND NORTHEAST INTO THE TN/OH VALLEYS...AS IT NEGATIVELY TILTS. AT THE SURFACE...A SURFACE LOW WILL DEEPEN AND BRING A ROUND OF SHOWERS ACROSS MUCH OF EASTERN KY FRIDAY AFTERNOON INTO FRIDAY NIGHT. AFTER THIS THE UPPER LEVEL ENERGY WILL THEN BE FOCUSED ON ANOTHER SURFACE LOW THAT DEVELOPS AND DEEPENS ALONG THE MID ATLANTIC COAST. IN EASTERN KY WE WILL CONTINUE TO SEE WRAP AROUND MOISTURE WITH THIS SYSTEM. MUCH COOLER AIR WILL TRAIL THIS SYSTEM AND EVENTUALLY LEAD TO A RAIN/SNOW MIX IN PRECIP SATURDAY AND ALL SNOW BY SATURDAY NIGHT. THESE CHANCES OF SNOW WILL TAPPER OFF SUNDAY. AFTER THIS THE MODELS REALLY BEGIN TO DIVERGE. THE GFS BRINGS ANOTHER CLIPPER DOWN FOR MONDAY...WHILE THE ECMWF KEEPS REGION DRY. RIGHT NOW WILL LEAN TO THE BLEND WHICH BRING SLIGHT CHANCES FOR SNOW SHOWERS ACROSS MUCH OF THE REGION MONDAY. OVERALL WENT TOWARD MODEL BLEND THROUGH THE PERIOD FOR MOST ELEMENTS. DID KEEP OR MAKE MINOR ADJUSTMENTS GIVEN TRENDS AND USUAL TOPO TEMP ISSUES. GIVEN THE CONSISTENCY FOR THE FRIDAY AND SATURDAY SYSTEM RIGHT NOW WOULD EXPECT POPS THAT PERIOD WILL CONTINUE TO TREND HIGHER...AS WE GET CLOSER TO THE PERIOD IF THESE TRENDS REMAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 125 AM EST TUE JAN 12 2016 VFR CONDITIONS WILL HOLD FOR MOST OF THE NIGHT BEFORE A QUICK HITTING CLIPPER SYSTEM MOVES INTO EASTERN KENTUCKY LATER THIS MORNING. FROM THIS...EXPECT REDUCED VISIBILITY AND MVFR CIGS AT SYM...JKL...AND SJS FOR A GOOD PORTION OF THE AFTERNOON WHILE MAINLY JUST SOME MVFR CIGS WILL BE SEEN AT LOZ AND SME. FOR MUCH OF THE PERIOD...THERE WILL BE SOME LIGHT SNOW SHOWERS AROUND SO MOST OF THE TAFS HAVE VCSH OUTSIDE OF THE MAIN SNOW WINDOW. WINDS WILL PICK UP THROUGH THE REST OF THE NIGHT AT ALL SITES FROM THE SOUTHWEST BEFORE SHIFTING TO THE WEST AND NORTHWEST LATER THIS AFTERNOON AND INCREASING TO BETWEEN 10 TO 20 KNOTS WITH GUSTS OF UP TO 30 KNOTS POSSIBLE IN SOME OF THE SNOW SHOWERS/SQUALLS. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044- 050>052-058>060-068-069-079-080. WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 11 PM EST THIS EVENING FOR KYZ086>088-104-106>120. && $$ SHORT TERM...GREIF LONG TERM...DJ AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
145 AM EST TUE JAN 12 2016 .UPDATE... ISSUED AT 145 AM EST TUE JAN 12 2016 DID A QUICK UPDATE TO THE NEAR TERM GRIDS TO INCORPORATE SOME OF THE SHORTBLEND GUIDANCE INTO THE TEMPERATURE AND DEWPOINT GRIDS FOR THE REST OF THE NIGHT. THE INVERSION IS BREAKING IN MOST PLACES AS THE WIND START TO PICK UP FROM THE WEST. SOME VALLEY SITES HAVE RISEN FROM THE LOW 20S INTO THE LOWER 30S DURING THE LATE NIGHT HOURS AS THE WINDS MOVED IN AND MIXED THE AIR. ELSEWHERE...THERE REMAINS SOME POCKETS OF LOWER AND MIDDLE 20S...BUT THESE SHOULD REBOUND TO NEAR FREEZING BY DAWN. ON RADAR...AND AS SEEN IN SOME OF THE OBS...VERY LIGHT SNOW SHOWERS AND FLURRIES ARE CROSSING OVER EASTERN KENTUCKY OUT AHEAD OF THE INBOUND ARCTIC BOUNDARY. HAVE TWEAKED POPS THROUGH DAWN TO BETTER REFLECT THIS. NO ACCUMULATIONS ARE EXPECTED FROM THIS SNOW UNTIL CLOSER TOWARD DAWN IN THE NORTH...SHIFTING SOUTH WITH TIME. THESE UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. UPDATE ISSUED AT 1057 PM EST MON JAN 11 2016 UPSTREAM IN INDIANA AND ILLINOIS...SNOW SHOWERS ARE BEGINNING TO DEVELOP AHEAD OF THE APPROACHING COLD FRONT. AS OF RIGHT NOW...THE SNOW SEEMS TO BE ON TRACK AND ON TIME FOR AN ARRIVAL INTO EASTERN KENTUCKY BY 12Z. THE REST OF THE FORECAST SEEMS TO CONTINUE TO BE ON TRACK. HAVE UPDATED TO INPUT THE LATEST OBS INTO THE GRIDS. UPDATE ISSUED AT 645 PM EST MON JAN 11 2016 WITH AN ANTICIPATED TEMPERATURES DROP AGAIN TONIGHT...CURRENT TEMPERATURE TRENDS LOOK TO BE ON TRACK WITH THE EXCEPTION OF A TWEAK HERE AND THERE TO THE TEMPS AND DEW POINTS. OTHERWISE...THE FORECAST REMAINS ON TRACK. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 355 PM EST MON JAN 11 2016 A CLOSED UPPER LEVEL LOW WAS OVER HUDSON BAY AS OF MID AFTERNOON WITH A SOMEWHAT BROAD TROUGH EXTENDING SOUTH INTO THE EASTERN CONUS. RIDGING EXTENDED INTO THE WESTERN CONUS. WITHIN THIS TROUGH...A SHORTWAVE WAS NEARING THE MID MS VALLEY WITH AN ADDITIONAL SHORTWAVE APPROACHING THE DAKOTAS AND UPPER MS VALLEY REGION. THE INITIAL SHORTWAVE IS EXPECTED TO ROTATE INTO THE LOWER OH VALLEY TONIGHT...WHILE THE SHORTWAVE FURTHER NORTHWEST SHOULD DEEPEN AS IT ROTATES INTO THE GREAT LAKES. A SFC LOW PRESSURE SYSTEM ASSOCIATED WITH THIS SHOULD BEGIN TO ORGANIZE BY THIS EVENING AND DEEPEN AS IT MOVES INTO THE GREAT LAKES AND SEND AN ARCTIC COLD FRONT INTO THE OH VALLEY AND APPALACHIAN REGION ON TUESDAY. AN INITIAL BAND OF SNOW IS EXPECTED TO MOVE INTO MAINLY NORTHERN PORTIONS OF THE AREA LATE TONIGHT INTO TUESDAY MORNING...POSSIBLY AFFECTING THE MORNING COMMUTE. ADDITIONAL SNOW SHOWERS AND OR SNOW SQUALLS ARE THEN EXPECTED AS THE ARCTIC BOUNDARY MOVES THROUGH ON TUESDAY AFTERNOON INTO TUESDAY EVENING...WITH THESE POSSIBLY IMPACTING THE EVENING COMMUTE. AN AIRMASS EQUALLY AS COLD AS THE ONE THAT MOVED INTO THE AREA ON SUNDAY INTO SUNDAY EVENING WILL MOVE INTO THE AREA BEHIND THIS FRONT FOR TUESDAY NIGHT. HEIGHT RISES ARE EXPECTED LATE IN THE PERIOD...WITH SFC HIGH PRESSURE BUILDING INTO THE AREA. SOMEWHAT LIMITED MOISTURE IS EXPECTED WITH THIS SYSTEM...WITH MANY OF THE MODELS SHOWING SOME VARIABILITY IN QPF AND ANY QPF MAX PLACEMENT. MODELS REMAIN MOST CONSISTENT WITH THE HIGHEST QPF ON AVERAGE ACROSS THE NORTH WHERE SOMEWHAT MORE STRATIFORM SNOW MAY AFFECT THE AREA VERY LATE TONIGHT INTO EARLY ON TUESDAY. ENOUGH INSTABILITY IS ANTICIPATED FOR SNOW SHOWERS AND A FEW SNOW SQUALLS THROUGHOUT THE DAY ON TUESDAY LINGERING INTO TUESDAY EVENING. THE LOW LEVEL FLOW NEVER BECOMES MORE IDEAL UPSLOPE WNW OR NW...HOWEVER. 1 TO 2 INCH AMOUNTS ARE ANTICIPATED ACROSS THE NORTH...WITH MORE VARIABLE AMOUNTS ANTICIPATED FURTHER SOUTH ACROSS THE CENTRAL AND SOUTHEAST PART OF THE AREA DUE TO THE NATURE OF SNOW SHOWERS OR SNOW SQUALLS. THE OTHER LIMITING FACTOR WILL BE TEMPERATURES POSSIBLY RISING A COUPLE OF DEGREES ABOVE FREEZING ACROSS THE VALLEYS AND PARTS OF THE SOUTH BEFORE THE FRONT GOES THROUGH. HOWEVER...COLD GROUND GOING INTO THE EVENT IS FAVORABLE. A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR MOST OF THE AREA STARTING LATE TONIGHT OR EARLY ON TUESDAY MORNING INTO TUESDAY EVENING. ISOLATED SNOW SHOWERS AND FLURRIES SHOULD LINGER WELL INTO TUESDAY NIGHT UNTIL THE LOW LEVEL CLOUDS SCATTER OUT. LOW TEMPERATURES ON TUESDAY NIGHT SHOULD BE COMPARABLE TO WHAT WAS OBSERVED THIS MORNING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 301 PM EST MON JAN 11 2016 ZONAL FLOW WILL RETURN THROUGH THE SECOND HALF OF THE WEEK...ALLOWING FOR A WARMING TREND INTO THE END OF THE WEEK. THIS WARM UP WILL BE BRIEF HOWEVER...AS ANOTHER DEEP UPPER LEVEL TROUGH DIGS ACROSS THE EASTERN CONUS. THIS WILL BRING MORE ACTIVE WEATHER AS WE HEAD THROUGH THE UPCOMING WEEKEND. THE PERIOD WILL START OFF COLD ON WEDNESDAY AS 850MB TEMPERATURES REMAIN UNDER -10C AND WITH POSSIBLE SNOW COVER...WEDNESDAY HIGHS ARE NOT EXPECTED TO RECOVER MUCH. A MUCH WEAKER CLIPPER SYSTEM WILL PUSH ACROSS THE OHIO RIVER VALLEY LATE WEDNESDAY AND BRING INCREASED CLOUD COVER TO THE REGION. HOWEVER...THIS TIME AROUND...LOW LEVEL MOISTURE IS LIMITED AND NOT EXPECTING ANY SNOWFALL. HOWEVER...THE CLOUD COVER WILL FURTHER LIMIT ANY TEMPERATURE RISE ON WEDNESDAY. HOWEVER...AS THIS CLIPPER SYSTEM MOVES ON OUT...SOUTH-SOUTHWEST FLOW WILL KICK IN WITH TEMPERATURE MODERATING ON THURSDAY AND FRIDAY. THIS WILL SEND HIGHS BACK ABOVE NORMAL WITH READING CLOSE TO 50 ON THURSDAY AND INTO THE 50S ON FRIDAY. A POTENT MID LEVEL WAVE WILL THEN EMERGE FROM THE SOUTHERN PLAINS FRIDAY HELPING TO GENERATE A LOW PRESSURE SYSTEM OVER THE MID MISSISSIPPI RIVER VALLEY. EASTERN KENTUCKY WILL REMAIN ON THE WARM SIDE OF THIS SYSTEM...WITH PRIMARILY RAIN EXPECTED. WHILE THERE IS STILL SOME TIMING DIFFERENCES...IT APPEARS RAIN CHANCES WILL INCREASE FRIDAY AFTERNOON WITH THE BEST CHANCES FOR RAIN COMING FRIDAY NIGHT. BY THIS WEEKEND...MODELS HAVE BEEN HAVING A TOUGH TIME RESOLVING HOW THINGS WILL PLAY OUT. OVERALL...THERE HAS BEEN A CLEAR TENDENCY TO SPEED UP THE SYSTEM...ALLOWING FOR A FASTER RETURN OF COLD WEATHER INTO EASTERN KENTUCKY ON SATURDAY. THIS MEANS IT LOOKS LIKE MORE OF THE WEEKEND IS SHAPING UP TO BE COLD WITH HIGHS ON SATURDAY ONLY IN THE 30S...AND HIGHS ON SUNDAY IN THE 20S. ON TOP OF THIS...AS THE RAIN DEPARTS LATE FRIDAY NIGHT...A SECONDARY SURGE OF MOISTURE WILL CROSS THE AREA SATURDAY AND COULD GIVE US SOME SNOW SHOWERS. FORTUNATELY...TEMPERATURES MAY NOT TAKE A SHARP TUMBLE...KEEPING TEMPERATURES NEAR OR SLIGHTLY ABOVE FREEZING THROUGH THE DAY AND LIMITING THE IMPACTS FROM ANY SNOW SHOWER ACTIVITY. HOWEVER...SATURDAY NIGHT INTO SUNDAY WILL BEAR WATCHING AS ANY MOISTURE LEFT ON THE ROADS COULD CAUSE ISSUES AS TEMPERATURES CONTINUE TO FALL. MODELS SUGGEST EITHER A SECOND WAVE TO COME THROUGH SUNDAY OR A SLOWER SYSTEM...TO KEEP SOME SNOW SHOWERS INTO THE FORECAST. HOWEVER...REALITY IS...WE PROBABLY WON`T SEE THAT MUCH SNOW OVERALL THIS WEEKEND...BUT HAD TO GO WITH A LONGER PERIOD TO ACCOUNT FOR MODEL UNCERTAINTY. WEATHER WILL QUIET DOWN BY LATE SUNDAY...BUT MODELS CONTINUE TO DIFFER ON EXACTLY HOW COLD WE GET LATE THIS WEEKEND INTO EARLY NEXT WEEK. ECMWF REMAINS THE COLDEST MODEL...WITH THE GFS QUITE A BIT MILDER. WILL CONTINUE TO STAY SOMEWHERE IN THE MIDDLE OF THESE TWO EXTREME SOLUTIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 125 AM EST TUE JAN 12 2016 VFR CONDITIONS WILL HOLD FOR MOST OF THE NIGHT BEFORE A QUICK HITTING CLIPPER SYSTEM MOVES INTO EASTERN KENTUCKY LATER THIS MORNING. FROM THIS...EXPECT REDUCED VISIBILITY AND MVFR CIGS AT SYM...JKL...AND SJS FOR A GOOD PORTION OF THE AFTERNOON WHILE MAINLY JUST SOME MVFR CIGS WILL BE SEEN AT LOZ AND SME. FOR MUCH OF THE PERIOD...THERE WILL BE SOME LIGHT SNOW SHOWERS AROUND SO MOST OF THE TAFS HAVE VCSH OUTSIDE OF THE MAIN SNOW WINDOW. WINDS WILL PICK UP THROUGH THE REST OF THE NIGHT AT ALL SITES FROM THE SOUTHWEST BEFORE SHIFTING TO THE WEST AND NORTHWEST LATER THIS AFTERNOON AND INCREASING TO BETWEEN 10 TO 20 KNOTS WITH GUSTS OF UP TO 30 KNOTS POSSIBLE IN SOME OF THE SNOW SHOWERS/SQUALLS. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 5 AM EARLY THIS MORNING TO 7 PM EST THIS EVENING FOR KYZ044-050>052-058>060-068-069-079-080. WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 11 PM EST THIS EVENING FOR KYZ086>088-104-106>120. && $$ UPDATE...GREIF SHORT TERM...JP LONG TERM...KAS AVIATION...GREIF
Area Forecast Discussion National Weather Service Louisville KY 1240 AM EST TUE JAN 12 2016 ...Updated Aviation Discussion... ...Forecast Update... Updated 1000 PM EST Mon Jan 11 2016 Updated the forecast to account for the latest trends this evening. Current radar imagery continues to show rather widespread echoes from portions of western KY northeastward into southern IN and Ohio. However, the 12/00Z ILN sounding depicted a few dry layers, one below 900mb and another one between 500-700mb. This dry air is likely even more pronounced over our region, thus these echoes have struggled to reach the ground. Therefore, don`t think we will see much more than some scattered flurries through about 6Z, with perhaps a localized snow shower in a heavier echo (like we are seeing currently over Hancock/Perry counties). Otherwise, the main show will come Tuesday morning. The latest guidance continues to trend slower with the accumulating snowfall potential, thus have delayed the higher pops from the previous forecast. The latest NAM has trended further north with the better snow amounts/snow burst potential. However, the latest HRRR runs continue to show accumulations likely approaching an inch as far south as a line form Ohio to Casey County, KY. Synoptically, the best PV advection will remain well north of I-64 as will the best low-level lapse rates/instability indices. Therefore, am not sold on the more southern HRRR solution. Will lean more towards the NAM solution which overall lowers amounts slightly across the region. However, do not want to cancel any headlines given the HRRR solution and the fact that any snowfall will accumulate given cold road temps, so will leave the Advisory as is for now. Updated products/maps will be out shortly. .SHORT TERM (Now through Tuesday Night)... Issued at 335 PM EST Mon Jan 11 2016 In the near term, high pressure over the southeastern US will continue to keep us dry this afternoon and evening. Temperatures across the region have warmed into the upper 20s in the far north to the middle-upper 30s across the south/southwestern sections. This evening will be dry with temperatures falling back into the upper 20s to around 30. Normally one would expect a sharper fall off in temperatures, but we`ll have a southwesterly wind that will keep temperatures up or at least hold steady through the evening hours. For tonight, all eyes will be on a weak clipper system that will be moving in tandem with a southward moving arctic cold front. This will result in a low pressure system moving through the Great Lakes with the cold front pushing through the Ohio Valley on Tuesday. Snow is expected to develop ahead of this system aided by isentropic lift ahead of the frontal system. Snow is likely to break out late this evening across southern IL and SW IN. This activity should move into our NW areas after 12/06Z. The snow should expand in coverage late tonight and then push into north-central KY toward dawn and then into central Kentucky during the morning and afternoon hours on Tuesday. The latest guidance is largely an extension of the 11/00Z and 06Z guidance. The best forcing still looks to largely reside across the northern half of our region. Combination of the small 500 hPa jet max crossing the region and a slightly stronger band of frontogenetical forcing will result in an expansion of snow shower activity Tuesday morning and afternoon. Model proximity soundings do show steepening low-level lapse rates during the day, so some intense snow showers and/or squalls may develop. A rumble of thunder is certainly not out of the question. The synoptic scale models continue to produce light QPF amounts, but we feel that these are slightly underdone given the expected convective nature of the snow shower activity. In addition, we could see some E-W banded snow showers set up...mainly across SE IN and into the northern Bluegrass region Tuesday morning. A general snowfall of 1 to 3 inches still looks likely across the northern half of the forecast area. Unlike more dynamic systems found across the region during the winter, a uniform snow does not look likely. Instead, the showery aspect of the storm will likely result in varying snowfall amounts over small distances. In areas that see repeated snow showers move through...or end up some banding feature, isolated amounts of up to 4 inches are not out of the question. In addition to the snow, winds will pick up dramatically and will likely gust into the 30-35 MPH range. This will result in blowing snow at times and reduced visibility. After evaluating the morning and afternoon datasets and collaborating with surrounding offices, a Winter Weather Advisory has been issued for late tonight through Tuesday for all of southern Indiana and much of northern KY. The snowfall is expected to negatively impact travel during the morning commute and during the day on Tuesday. Motorists should expect travel problems in the morning and allow extra time to reach destinations. Highs on Tuesday will range from the upper 20s int he north to the middle 30s along the KY/TN state line. Temperatures will fall during the late afternoon and evening hours. Lows tomorrow night will be dependent on snow cover and sky cover. If skies clear out, single digit readings across the north will be attainable with other areas seeing lows in the lower teens. .LONG TERM (Wednesday through Monday)... Issued at 405 PM EST Mon Jan 11 2016 Upper trough axis will shift eastward during the day on Wednesday. A second but weaker impulse aloft will cruise through the region during the day on Wednesday may produce a few flurries as it pushes through. After that passes, mid-level ridging will build into the region and we`ll see temperatures moderate as we move through Thursday and into Friday. Highs Wednesday will warm into the mid- upper 20s in the north with upper 20s to lower 30s across the central sections and mid 30s down across southern KY. Lows Wednesday night will cool back into the lower-mid 20s and highs on Thursday look to warm into the middle 40s in the north with upper 40s to lower 50s across the south. The quiet and milder weather will not last long through. By Thursday night, a mid-level wave will spawn an area of surface low pressure over the Mid-Mississippi valley. This feature will quickly race to the northeast bringing a round of rain showers to the region during the day on Friday and into Friday night. The low pressure system looks to pass through the region Friday night and will be exiting our region by Saturday morning. Colder air will wrap back down into the region on Saturday resulting in some light rain/snow showers depending on how fast the lower atmosphere cools. A second, but stronger trough axis will then drop into the region Saturday night resulting in some more snow showers for Saturday evening and overnight into Sunday. For Sunday and Monday, deep 500 hPa closed low will drop into the Great Lakes and then move into southern New England by Monday. A strong northwesterly flow will push very cold Arctic air into region during the period. We have lowered temperatures quite a bit for Sunday with highs in the lower 20s in the north and upper 20s in the south. The SuperBlend guidance is likely going to play catch up here and the next load of it will likely push temps down into the teens for highs on Sun/Mon with overnight lows in the single digits. && .AVIATION (06Z TAF Update)... Updated at 1240 AM EST Tue Jan 12 2016 Winds both at the surface and aloft have increased ahead of an approaching storm system. AMDAR soundings out of SDF have been showing winds of 35 to 40 knots around 2k feet off the surface, and model data suggest this will continue for a few more hours and possibly increase in speed a few knots. So, will include LLWS in the TAFs. Low pressure crossing Michigan will swing a cold front through the region during the daylight hours this morning. This front will bring a quick (2-4 hour) shot of snow showers and MVFR cigs/vsbys to SDF and LEX (little more than flurries and a shower or two to BWG). These snow showers will be accompanied by very gusty winds coming in from the WSW. Behind the snow showers and cold front winds will remain strong, coming in from the west and possibly gusting to 30 or 35 knots, especially at SDF and LEX during the late morning and early afternoon hours. Ceilings this afternoon are a bit tougher to figure out...for now will hold on to an MVFR stratocu ceiling for much of the afternoon at the northern TAF sites, though that may be on the pessimistic side. High pressure advancing from STL to BNA tonight will clear skies and bring wind speeds down. && .LMK Watches/Warnings/Advisories... KY...Winter Weather Advisory until 4 PM EST /3 PM CST/ this afternoon for KYZ023>025-028>034-038-045-053. Winter Weather Advisory from 5 AM early this morning to 7 PM EST this evening for KYZ035>037-039>043-046>049-054>057-065>067. IN...Winter Weather Advisory until 4 PM EST /3 PM CST/ this afternoon for INZ076>079-083-084-089>092. && $$ Update.........KJD Short Term.....MJ Long Term......MJ Aviation.......13
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 AM EST TUE JAN 12 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EST TUE JAN 12 2016 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UPR TROF DOMINATING THE E HALF OF NAMERICA DOWNSTREAM OF HI AMPLITUDE RDG OVER THE W. POTENT SHRTWV DIGGING SEWD THRU THE TROF IS DIGGING SEWD THRU THE UPR MIDWEST...BRINGING 12HR H5 HGT FALLS TO ARND 100M AT INL AND MPX. ALTHOUGH THE SHRTWV ITSELF IS PASSING FAIRLY FAR TO THE S...DEEP LYR QVECTOR CNVGC AS WELL DEEP MOISTENING SHOWN ON THE 00Z INL RAOB ARE IMPACTING UPR MI...BRINGING SOME -SN TO MUCH OF THE CWA DESPITE LACK OF MSTR INFLOW/VERY DRY LLVLS SHOWN ON THE 00Z GRB RAOB. LLVL WINDS/SFC OBS ALSO INDICATE A SHARP LK INDUCED TROF IS IN THE PROCESS OF MOVING ONSHORE EARLY THIS MRNG AS THE LLVL WINDS VEER TO THE NNW FOLLOWING SHRTWV PASSAGE TO THE S. THE WSHFT/TROF PASSAGE AT CMX AND IWD WAS ACCOMPANIED BY SOME HEAVY SN SHOWERS. MQT RADAR IS ALSO SHOWING SOME MORE SGNFT RETURNS OVER SCENTRAL LK SUP EARLY THIS MRNG. TO THE N...THE 00Z H85 TEMP AT PICKLE LAKE ONTARIO WAS -30C...BUT THE NEAR SFC LYR THERE IS RATHER DRY. SKIES ARE MOCLR OVER MOST OF NRN MN/ADJOINING NW ONTARIO...WITH SFC DEWPTS NEAR -20F. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMNTS ASSOCIATED WITH THE SHRTWV/LK INDUCED TROF AND THEN LES TRENDS FOLLOWING THE PASSAGE OF THE SHRTWV/INFLUX OF COLDER AND DRIER AIR. TODAY...AS THE DIGGING SHRTWV EXITS TO THE SE...LLVL WINDS ARE FCST TO SHIFT TO THE NNW EARLY THIS MRNG...DRIVING THE LK INDUCED TROF STILL OVERL K SUP EARLY THIS MRNG. THE TROF IS EXPECTED TO BE THRU THE WRN ZNS BY FCST ISSUANCE...MARQUETTE ARND 12Z AND THEN NEWBERRY ARND 15Z. HIER RES RAP MODEL FCST SNDGS FOR SEVERAL LOCATIONS NEAR LK SUP SHOW A VERY SHARP AXIS OF ENHANCED LLVL UVV CENTERED WITHIN THE DGZ IN THE 1-4K FT AGL LYR...SO STILL EXPECT A BURST OF HEAVER SN WHEN THIS TROF COMES ONSHORE. HIER RES MODELS HINT AT 0.10-0.20 INCH OF WATER EQUIVALENT PCPN IN THE 6HR PERIOD CENTERED ARND THE TROF PASSAGE...WHICH WOULD SUPPORT AS MUCH AS 3-4 INCHES OF SN GIVEN THE FAVORABLE SN/WATER RATIOS. FARTHER INLAND...THE TROF/LLVL CNVGC ARE FCST TO WASH OUT...SO THE HEAVIER SN SHOWERS SHOULD OCCUR ONLY NEAR THE LK SUP SHORE. SHARP WSHFT OFF THE LK WITH LLVL MIXED LYR WINDS UP TO 30 KTS WL ALSO RESULT IN SOME BLSN/REDUCED VSBYS. GOING ADVYS IN THE LK SHORE COUNTIES SEEM APPROPRIATE. FOLLOWING THE TROF PASSAGE...DVLPG LARGER SCALE QVECTOR DVGC/ SUBSIDENCE ABOVE LLVL COLD SURGE THAT WL DROP H85 TEMPS TO AS LO AS -24C WL RESULT IN THE MORE TYPICAL WIND PARALLEL PURE LES BANDS. ASSOCIATED MID LVL DRYING/SUBSIDENCE INVRN BASE LOWERING TO 4-5K FT AGL AND IMPACT OF LLVL DRY AIR NOTED FARTHER UPSTREAM WL TEND TO LIMIT THE PURE LES ACCUMS AS WILL SHIFTING BANDS RELATED TO EXPECTED STEADILY BACKING WINDS TO THE WNW BY LATER IN THE DAY. WITH THE INFLUX OF VERY COLD AIR...MAX TEMPS WL RUN WELL BLO NORMAL AND NOT RISE ABOVE 5 TO 10F OVER THE W. TNGT...MODELS INDICATE ANOTHER SHRTWV SLIDING SEWD IN THE NW FLOW ALOFT WL MOVE INTO THE AREA TNGT...WITH AREA OF DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF THIS FEATURE RESULTING IN DEEPENING MSTR/SOME RISE IN INVRN BASE. THE LLVL WINDS ARE FCST TO BACK TO ABOUT 270-280 DEGREES BY 12Z WED...SO NRN ONTONAGON COUNTY/HOUGHTON COUNTIES AND AREAS NEAR LK SUP FM GRAND MARAIS TO WHITEFISH POINT LOOK TO BE THE FOCUS FOR THE HEAVIER SN SHOWERS. ENHANCED LAND BREEZE CNVGC RELATED TO THE VERY COLD AIR THAT WL DROP MIN TEMPS AT LEAST CLOSE TO -10F IN THE UNMODIFIED AIR NEAR THE WI BORDER WL SHARPER THE LLVL CNVGC AND THE SRN EDGE OF THE HEAVIER SN SHOWERS. SINCE NAM FCST SDNGS FOR CMX SHOW INCRSG UVV WITHIN THE DGZ TOWARD 12Z WED...NOT OUT OF THE QUESTION SOME ADVY LES WL OCCUR IN THESE FAVORED AREAS. ALTHOUGH WINDS ARE NOT LIKELY TO STAY UP NEAR THE WIND CHILL ADVY THRESHOLD OF 10 MPH OVER THE INTERIOR COLD SPOTS NEAR THE BORDER...APRNT TEMPS ARE LIKELY TO FALL AS LO AS -20 TO -25F. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 309 AM EST TUE JAN 12 2016 THE UPPER GREAT LAKES WILL STILL BE UNDER THE INFLUENCE OF THE ARCTIC AIR MASS AT THE START OF THE LONG TERM FORECAST...WITH LAKE EFFECT SNOW ONGOING IN THE WESTERLY WIND SNOW-BELTS. STILL EXPECT LIGHT TO MODERATE LAKE EFFECT TO BE OCCURRING OVER THE WEST AND KEWEENAW PENINSULA WEDNESDAY MORNING WITH INVERSION HEIGHTS AROUND 6KFT AND SOME INCREASED LOW LEVEL CONVERGENCES DUE TO THE HIGH PRESSURE RIDGE SLIDING TO THE SOUTH OF THE AREA AIDING LOW LEVEL BACKING FLOW OVER THE FAR WESTERN U.P.. SINCE THE LOWERING INVERSION WILL START TO KEEP MORE OF THE CLOUD LAYER WITHIN THE DGZ...SHOULD START TO SEE RATIOS COME UP AND WOULD THINK THERE WILL BE AN AREA OF ADVISORY SNOWFALL WITHIN THE DOMINATE BAND SETUP OVER NORTHERN ONTONAGON AND NORTHERN HOUGHTON COUNTIES AND SOMEWHERE BETWEEN SOUTH RANGE AND GREENLAND. THIS BAND SHOULD LIFT NORTH THROUGH THE AFTERNOON AND BE CENTERED AROUND OR TO THE NORTH OF HOUGHTON. AS TEMPERATURES ALOFT MODERATE THROUGH THE AFTERNOON/NIGHT (850MB TEMPS RISE TO -17C)...EXPECT ALL OF THE CLOUD TO FALL WITHIN THE DGZ WHICH WILL LEAD TO VERY FLUFFY SNOW AND HIGH RATIOS THROUGH WEDNESDAY NIGHT. WILL TREND POPS/RATIOS/SNOWFALL UP WITH THE FAVORABLE CONDITIONS FOR THE KEWEENAW WEDNESDAY AFTERNOON AND NIGHT BEFORE WARMING ALOFT (ASSOCIATED WITH THE APPROACHING SURFACE TROUGH AHEAD OF THE PLAINS LOW) QUICKLY BRINGS AN END TO THE LES ON THURSDAY MORNING. OVER THE EAST...THE WEST TO EVENTUALLY WEST-SOUTHWEST WINDS WILL KEEP THE BANDS LARGELY OFFSHORE BUT DID INCLUDE SOME HIGHER POPS IN CASE THE BAND AFFECTS AREAS TO THE EAST OF GRAND MARAIS. ONE FINAL ITEM OF NOTE BEFORE GETTING INTO THE LOW DEVELOPING INTO THE PLAINS...SHOULD SEE A WEAK SHORTWAVE MOVING THROUGH WISCONSIN WEDNESDAY NIGHT AND COULD SEE A FEW LIGHT SNOW SHOWERS ALONG THE WISCONSIN BORDER THROUGH THE NIGHT. THE SECOND HALF OF THE LONG TERM FORECAST WILL BE FOCUSED ON THE SURFACE LOW DEVELOPING IN THE NORTHERN/CENTRAL PLAINS AS A SHORTWAVE CROSSES THE ROCKIES. AS IT DEVELOPS AND SLIDES SOUTHEAST INTO THE MID MISSISSIPPI VALLEY THURSDAY INTO THURSDAY NIGHT...IT WILL STRETCH A TROUGH EAST-NORTHERN INTO THE GREAT LAKES REGION. AT THIS POINT...MODELS ARE FAIRLY CONSISTENT ON THE SURFACE TROUGH BEING JUST TO THE SOUTH OF THE AREA AND STRETCHING EAST ACROSS SOUTHERN WISCONSIN AND LOWER MICHIGAN. BUT WITH WEAK MID LEVEL WARM AIR ADVECTION TO THE NORTH OF THE TROUGH...SHOULD SEE SOME LIGHT SNOW SHOWERS MOVING ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT. RIGHT NOW...LOOKING LIKE 1-3 INCHES OF SNOW FROM THURSDAY NIGHT INTO FRIDAY...WITH THE HIGHEST AMOUNTS WHERE THE LAKE ENHANCEMENT OCCURS. THAT POTENTIAL INCREASES THURSDAY NIGHT INTO FRIDAY AS THE TROUGH SLIDES EAST AND THE LOW BEGINS TO STRENGTHEN IN NORTHERN MISSOURI AS THE SHORTWAVE MERGES WITH A SOUTHERN STREAM WAVE. EXPECT THE LES TO OCCUR IN THE NORTHEASTERLY WIND AREAS...WITH THE BEST SNOW POTENTIAL OCCURRING IN THE UPSLOPE AREAS OF MARQUETTE COUNTY (ESPECIALLY THE HURON MOUNTAINS). WILL TREND POPS UP FOR THAT AREA...BUT WITH MUCH OF THE CLOUD HOVERING AROUND OR JUST BELOW -10C...DON/T EXPECT THE LAKE EFFECT/ENHANCEMENT TO GET TO OUT OF HAND. MODELS STILL STRUGGLING WITH THE EXTENDED PERIOD...ESPECIALLY THE THE EVOLUTION OF THE LOW COMING OUT OF THE CENTRAL MISSISSIPPI VALLEY. THE 00Z ECMWF HAS SHIFTED AWAY FROM THE PREVIOUS RUNS AND TOWARDS WHAT THE 11/00Z RUN OF THE GFS WAS SHOWING (TRACKING THE LOW FARTHER NORTHWEST THROUGH NORTHERN LOWER MICHIGAN DUE TO A MORE ELONGATED UPPER TROUGH). MEANWHILE...THE 00Z GEM/GFS TRACK THE LOW THROUGH SOUTHEASTERN LOWER MICHIGAN BUT THAT IS ENOUGH TO HAVE SOME LIGHT SNOWFALL OVER THE SOUTHEAST HALF OF THE CWA. AT THIS POINT...THINK CHANCE POPS IS THE WAY TO GO WITH LIKELIES OVER THE NORTH CENTRAL WITH LAKE ENHANCEMENT. ANOTHER SURGE OF ARCTIC AIR DROPS INTO THE AREA FOR THE SECOND HALF OF THE WEEKEND AND EARLY NEXT WEEK BUT IT LOOKS LIKE IT WON/T BE AS COLD OR LAST AS LONG AS THIS PAST ARCTIC AIR PERIOD. SHOULD STILL SEE LAKE EFFECT SNOW THOUGH AND WILL TREND POPS UP (TO LIKELY VALUES AT LEAST) FOR THE NORTH-NORTHWESTERLY WIND AREAS ON SUNDAY AND MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1220 AM EST TUE JAN 12 2016 A LOW PRES TROF WILL DROP S ACROSS LAKE SUPERIOR AND INTO UPPER MI...BRINGING A WSHFT FROM SW TO THE NNW. WHILE THERE MAY BE SOME -SN WITH MVFR/IFR CONDITIONS AHEAD OF IT...IN ITS WAKE...HEAVY LAKE EFFECT SNOW SHOWERS WILL BRING A PERIOD OF LIFR CONDITIONS TO ALL TERMINALS LATE TONIGHT INTO TUE MORNING. ALTHOUGH CONDITIONS WILL LIKELY REMAIN A PREVAILING LIFR AT KIWD/KCMX TUE MORNING...SLIGHT BACKING OF WINDS SHOULD SHIFT HEAVIER SNOW SHOWERS E OF KSAW LATE IN THE MORNING...RESULTING IN A RETURN OF MVFR CONDITIONS. KIWD WILL SEE A RETURN TO MVFR CONDITIONS TUE EVENING AS HEAVIER SNOW BANDS SHIFT NORTH AS WINDS BACK TO THE WEST WHILE FAVORABLE CONVERGENT WEST FLOW AT KCMX WILL MAINTAIN IFR TO POSSIBLE LIFR VSBYS AT TIMES IN LES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 AM EST TUE JAN 12 2016STRONG NNW WINDS TODAY WILL REACH 30 KTS UNDER A TIGHT PRES GRADIENT BETWEEN LO PRES TRACKING THRU THE LOWER GREAT LAKES AND CANADIAN HI PRES BUILDING INTO THE NORTHERN PLAINS. ALTHOUGH GALES ARE NOT EXPECTED...THE INCOMING AIRMASS WILL BE SUFFICIENTLY COLD TO GENERATE HEAVY FREEZING SPRAY. THE WINDS WILL BACK MORE TO THE NW THIS AFTERNOON AND DIMINISH AS THE HI PRES RIDGE GETS CLOSER...SO THE HEAVY FREEZING SPRAY WILL END. RELATIVELY LIGHT WINDS UNDER 25 KTS WILL THEN DOMINATE LATE TONIGHT THRU THU NIGHT. BUT AS ANOTHER LO PRES MOVES NE THRU THE CENTRAL GREAT LAKES ON FRI/SAT...NE WINDS WILL INCREASE UP TO 30 KTS UNDER THE TIGHTER PRES GRADIENT BETWEEN THE LO AND COLD HI PRES IN WCENTRAL CANADA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ005. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LSZ248-249-265-266. HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ241>244-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
309 AM EST TUE JAN 12 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 439 PM EST MON JAN 11 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP MID/UPPER TROF EXTENDING FROM HUDSON BAY S THRU THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES REGION DOWNSTREAM OF A RIDGE EXTENDING ALONG THE W COAST OF CANADA THRU NE ALASKA. A RATHER VIGOROUS LOOKING SHORTWAVE IS DROPPING SE THRU ERN ND/NW MN. ANOTHER WEAKER SHORTWAVE TROF IS SWINGING S THRU NRN MANITOBA. THESE 2 FEATURES...ESPECIALLY THE FIRST SHORTWAVE...WILL DRIVE THE FCST IN THE SHORT TERM. WITH LATEST RAP ANALYSIS SHOWING 850MB TEMPS AROUND -20C ACROSS LAKE SUPERIOR... LES CONTINUES. HOWEVER...BACKING WINDS IN RESPONSE TO THE APPROACHING SHORTWAVE HAS RESULTED IN LES BANDS SHIFTING OFFSHORE OF MORE OF UPPER MI DURING THE DAY. ALTHOUGH CLOUD TOPS WERE UP TO AROUND 10KFT PER KMQT RADAR EARLIER TODAY...THE SHIFTING WINDS... LACK OF WELL ORGANIZED BANDS...AND A MORE SUPPRESSED DGZ TO THE LOWER PART OF THE CONVECTIVE LAYER HAVE KEPT SNOW ACCUMULATIONS IN CHECK. WITH LES ALREADY ONGOING ACROSS LAKE SUPERIOR...APPROACHING SHORTWAVE WILL RESULT IN THE NORMAL INTENSIFICATION OF LES TONIGHT/TUE MORNING. WINDS WILL CONTINUE TO BACK OVER THE NEXT FEW HRS IN RESPONSE TO THE STRONGER SHORTWAVE DROPPING SE THRU MN. THEN AS SFC TROF ASSOCIATED WITH SHORTWAVE MOVES S OVER LAKE SUPERIOR...A SHARPER CONVERGENCE ZONE WILL DEVELEOP THIS EVENING... RUNNING FROM NEAR THE APOSTLE ISLANDS TO N OF COPPER HARBOR THEN OVER TO MICHIPICOTEN ISLAND. CONVERGENCE ZONE SHOULD ALSO HELP LIFT DGZ A BIT HIGHER INTO THE CONVECTIVE LAYER TO INCREASE SNOW-TO-WATER RATIOS. ALTHOUGH THE TRACK OF THE SHORTWAVE IS A BIT FARTHER S THAN IDEAL (PEAK DEEP LAYER FORCING PASSES S OF LAKE SUPERIOR)...SYNOPTIC FORCING/DEEP MOISTURE WILL BE MORE THAN SUFFICIENT TO AID DEVELOPMENT OF HVY SNOW ALONG THE CONVERGENCE ZONE THAT WILL DROP S TONIGHT/EARLY TUE MORNING. WITH WINDS AT LEAST BRIEFLY SHIFTING NNW/N WITH PASSAGE OF SFC TROF...ALL LOCATIONS ALONG LAKE SUPERIOR WILL SEE AT LEAST A BRIEF BURST OF MDT/HVY SNOW. AREA FROM KIWD TO AROUND THE PORCUPINE MOUNTAINS AND FROM VCNTY OF MARQUETTE OVER THE GRAND MARAIS SHOULD SEE THE HEAVIEST SNOW WITH THE TROF PASSAGE. KEWEENAW COUNTY MAY ALSO END UP WITH SOME OF THE HEAVIEST SNOW DUE TO LONG FETCH HVY SNOW BAND INITIATING NEAR THE APOSTLE ISLANDS ALONG THE SFC TROF. LOCAL HIRES WRF RUN AND CANADIAN HIGH RES RUNS BOTH HAVE A HIGHER PCPN SIGNATURE IN KEWEENAW COUNTY. SO...LES ADVYS WILL REMAIN UP FROM GOGEBIC COUNTY THRU THE KEWEENAW. MARQUETTE/ALGER COUNTIES WILL ALSO BE ADDED. THE FACT THAT THE HVY SNOW/GUSTY WINDS ARRIVE JUST BEFORE AND DURING THE MORNING COMMUTE SHOULD LEAD TO ESPECIALLY DIFFICULT DRIVING CONDITIONS TUE MORNING FOR MARQUETTE/ALGER COUNTIES. MAY NEED TO CONSIDER ADDING NRN SCHOOLCRAFT/LUCE COUNTIES TO ADVY FOR TUE...BUT RIGHT NOW HAVE SNOW ACCUMULATIONS NEAR/JUST UNDER ADVY CRITIERIA. WIND PARALLEL LES BANDS WILL SET UP A FEW HRS AFTER THE TROF PASSES AND WILL THEN SLOWLY SHIFT THRU THE DAY TUE AS WINDS BACK WNW OVER WRN LAKE SUPERIOR AND NW OVER ERN LAKE SUPERIOR. TOTAL SNOW ACCUMULATIONS TONIGHT/TUE WILL GENERALLY RANGE FROM 2 TO 7 INCHES ALONG LAKE SUPERIOR WITH HIGHEST AMOUNTS VCNTY OF THE PORCUPINE MTNS AND JUST E OF MARQUETTE TO PICTURED ROCKS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 309 AM EST TUE JAN 12 2016 THE UPPER GREAT LAKES WILL STILL BE UNDER THE INFLUENCE OF THE ARCTIC AIR MASS AT THE START OF THE LONG TERM FORECAST...WITH LAKE EFFECT SNOW ONGOING IN THE WESTERLY WIND SNOW-BELTS. STILL EXPECT LIGHT TO MODERATE LAKE EFFECT TO BE OCCURRING OVER THE WEST AND KEWEENAW PENINSULA WEDNESDAY MORNING WITH INVERSION HEIGHTS AROUND 6KFT AND SOME INCREASED LOW LEVEL CONVERGENCES DUE TO THE HIGH PRESSURE RIDGE SLIDING TO THE SOUTH OF THE AREA AIDING LOW LEVEL BACKING FLOW OVER THE FAR WESTERN U.P.. SINCE THE LOWERING INVERSION WILL START TO KEEP MORE OF THE CLOUD LAYER WITHIN THE DGZ...SHOULD START TO SEE RATIOS COME UP AND WOULD THINK THERE WILL BE AN AREA OF ADVISORY SNOWFALL WITHIN THE DOMINATE BAND SETUP OVER NORTHERN ONTONAGON AND NORTHERN HOUGHTON COUNTIES AND SOMEWHERE BETWEEN SOUTH RANGE AND GREENLAND. THIS BAND SHOULD LIFT NORTH THROUGH THE AFTERNOON AND BE CENTERED AROUND OR TO THE NORTH OF HOUGHTON. AS TEMPERATURES ALOFT MODERATE THROUGH THE AFTERNOON/NIGHT (850MB TEMPS RISE TO -17C)...EXPECT ALL OF THE CLOUD TO FALL WITHIN THE DGZ WHICH WILL LEAD TO VERY FLUFFY SNOW AND HIGH RATIOS THROUGH WEDNESDAY NIGHT. WILL TREND POPS/RATIOS/SNOWFALL UP WITH THE FAVORABLE CONDITIONS FOR THE KEWEENAW WEDNESDAY AFTERNOON AND NIGHT BEFORE WARMING ALOFT (ASSOCIATED WITH THE APPROACHING SURFACE TROUGH AHEAD OF THE PLAINS LOW) QUICKLY BRINGS AN END TO THE LES ON THURSDAY MORNING. OVER THE EAST...THE WEST TO EVENTUALLY WEST-SOUTHWEST WINDS WILL KEEP THE BANDS LARGELY OFFSHORE BUT DID INCLUDE SOME HIGHER POPS IN CASE THE BAND AFFECTS AREAS TO THE EAST OF GRAND MARAIS. ONE FINAL ITEM OF NOTE BEFORE GETTING INTO THE LOW DEVELOPING INTO THE PLAINS...SHOULD SEE A WEAK SHORTWAVE MOVING THROUGH WISCONSIN WEDNESDAY NIGHT AND COULD SEE A FEW LIGHT SNOW SHOWERS ALONG THE WISCONSIN BORDER THROUGH THE NIGHT. THE SECOND HALF OF THE LONG TERM FORECAST WILL BE FOCUSED ON THE SURFACE LOW DEVELOPING IN THE NORTHERN/CENTRAL PLAINS AS A SHORTWAVE CROSSES THE ROCKIES. AS IT DEVELOPS AND SLIDES SOUTHEAST INTO THE MID MISSISSIPPI VALLEY THURSDAY INTO THURSDAY NIGHT...IT WILL STRETCH A TROUGH EAST-NORTHERN INTO THE GREAT LAKES REGION. AT THIS POINT...MODELS ARE FAIRLY CONSISTENT ON THE SURFACE TROUGH BEING JUST TO THE SOUTH OF THE AREA AND STRETCHING EAST ACROSS SOUTHERN WISCONSIN AND LOWER MICHIGAN. BUT WITH WEAK MID LEVEL WARM AIR ADVECTION TO THE NORTH OF THE TROUGH...SHOULD SEE SOME LIGHT SNOW SHOWERS MOVING ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT. RIGHT NOW...LOOKING LIKE 1-3 INCHES OF SNOW FROM THURSDAY NIGHT INTO FRIDAY...WITH THE HIGHEST AMOUNTS WHERE THE LAKE ENHANCEMENT OCCURS. THAT POTENTIAL INCREASES THURSDAY NIGHT INTO FRIDAY AS THE TROUGH SLIDES EAST AND THE LOW BEGINS TO STRENGTHEN IN NORTHERN MISSOURI AS THE SHORTWAVE MERGES WITH A SOUTHERN STREAM WAVE. EXPECT THE LES TO OCCUR IN THE NORTHEASTERLY WIND AREAS...WITH THE BEST SNOW POTENTIAL OCCURRING IN THE UPSLOPE AREAS OF MARQUETTE COUNTY (ESPECIALLY THE HURON MOUNTAINS). WILL TREND POPS UP FOR THAT AREA...BUT WITH MUCH OF THE CLOUD HOVERING AROUND OR JUST BELOW -10C...DON/T EXPECT THE LAKE EFFECT/ENHANCEMENT TO GET TO OUT OF HAND. MODELS STILL STRUGGLING WITH THE EXTENDED PERIOD...ESPECIALLY THE THE EVOLUTION OF THE LOW COMING OUT OF THE CENTRAL MISSISSIPPI VALLEY. THE 00Z ECMWF HAS SHIFTED AWAY FROM THE PREVIOUS RUNS AND TOWARDS WHAT THE 11/00Z RUN OF THE GFS WAS SHOWING (TRACKING THE LOW FARTHER NORTHWEST THROUGH NORTHERN LOWER MICHIGAN DUE TO A MORE ELONGATED UPPER TROUGH). MEANWHILE...THE 00Z GEM/GFS TRACK THE LOW THROUGH SOUTHEASTERN LOWER MICHIGAN BUT THAT IS ENOUGH TO HAVE SOME LIGHT SNOWFALL OVER THE SOUTHEAST HALF OF THE CWA. AT THIS POINT...THINK CHANCE POPS IS THE WAY TO GO WITH LIKELIES OVER THE NORTH CENTRAL WITH LAKE ENHANCEMENT. ANOTHER SURGE OF ARCTIC AIR DROPS INTO THE AREA FOR THE SECOND HALF OF THE WEEKEND AND EARLY NEXT WEEK BUT IT LOOKS LIKE IT WON/T BE AS COLD OR LAST AS LONG AS THIS PAST ARCTIC AIR PERIOD. SHOULD STILL SEE LAKE EFFECT SNOW THOUGH AND WILL TREND POPS UP (TO LIKELY VALUES AT LEAST) FOR THE NORTH-NORTHWESTERLY WIND AREAS ON SUNDAY AND MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1220 AM EST TUE JAN 12 2016 A LOW PRES TROF WILL DROP S ACROSS LAKE SUPERIOR AND INTO UPPER MI...BRINGING A WSHFT FROM SW TO THE NNW. WHILE THERE MAY BE SOME -SN WITH MVFR/IFR CONDITIONS AHEAD OF IT...IN ITS WAKE...HEAVY LAKE EFFECT SNOW SHOWERS WILL BRING A PERIOD OF LIFR CONDITIONS TO ALL TERMINALS LATE TONIGHT INTO TUE MORNING. ALTHOUGH CONDITIONS WILL LIKELY REMAIN A PREVAILING LIFR AT KIWD/KCMX TUE MORNING...SLIGHT BACKING OF WINDS SHOULD SHIFT HEAVIER SNOW SHOWERS E OF KSAW LATE IN THE MORNING...RESULTING IN A RETURN OF MVFR CONDITIONS. KIWD WILL SEE A RETURN TO MVFR CONDITIONS TUE EVENING AS HEAVIER SNOW BANDS SHIFT NORTH AS WINDS BACK TO THE WEST WHILE FAVORABLE CONVERGENT WEST FLOW AT KCMX WILL MAINTAIN IFR TO POSSIBLE LIFR VSBYS AT TIMES IN LES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 502 PM EST MON JAN 11 2016 MUCH OF THIS PERIOD WILL BE MARKED BY AN AREA OF LOW PRESSURE OVER LAKE SUPERIOR. LOW PRESSURE INITIALLY ACROSS LAKE SUPERIOR AND WI WILL DEEPEN OVER S LAKE HURON BY TUESDAY MORNING. NNW WINDS TO 30 KTS EXPECTED TONIGHT...WITH WITH SOME GALE FORCE GUSTS UP TO 35 KTS. THE LOW WILL EXIT ALONG S QUEBEC AND THE NEW ENGLAND STATES LATE IN THE DAY...AS THE LINGERING TROUGH OVER LAKE SUPERIOR WEAKENS SLIGHTLY AND HIGH PRESSURE BUILDS INTO THE MISSISSIPPI VALLEY TUESDAY NIGHT INTO WEDNESDAY. ANOTHER ROUND OF COLD AIR SINKING IN WILL BRING ANOTHER PERIOD OF HEAVY FREEZING SPRAY TO W AND N CENTRAL LAKE SUPERIOR LATE TONIGHT AND TUESDAY. LOW PRESSURE OVER FAR N MANITOBA...AND AN ADDITIONAL LOW OVER S ALBERTA WEDNESDAY EVENING WILL COMBINE AND SETTLE ACROSS THE CENTRAL PLAINS THURSDAY NIGHT. EXPECT THE SURFACE LOW TO LIFT NORTHEAST ACROSS THE LOWER GREAT LAKES SATURDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ005. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LSZ248-249-265-266. HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ241>244-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...VOSS MARINE...KF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1232 AM EST TUE JAN 12 2016 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 305 PM EST MON JAN 11 2016 A WAVE OF LOW PRESSURE WILL DEEPEN AS IT TRACKS EASTWARD THROUGH LOWER MICHIGAN TONIGHT. SNOW WILL INCREASE ACROSS THE REGION AS A RESULT AND COULD BE HEAVY. THE SNOW WILL PERSIST THROUGH TUESDAY WITH LOCALLY HEAVY SNOW ESPECIALLY CLOSE TO LAKE MICHIGAN. HAZARDOUS TRAVEL IS EXPECTED FOR MOST AREA THROUGH TUESDAY. ARCTIC AIR WILL CONTINUE TO FLOW INTO THE REGION ON WEDNESDAY WITH ADDITIONAL LAKE EFFECT SNOW POSSIBLE. && .UPDATE... ISSUED AT 915 PM EST MON JAN 11 2016 FIRST SHORT WAVE IS JUST MOVING THROUGH AND LAKE EFFECT HAS FLARED UP IN RESPONSE. RADAR SHOWS LIGHT TO MODERATE SHSN OVER THE WEST CENTRAL CWA. THE HEAVIEST SNOW WILL REORIENT OVERNIGHT AS WINDS BECOME WEST AND THEN NORTHWEST. THE NEXT SHORT WAVE IS WELL SEEN IN WV IMAGERY OVER WISCONSIN AND WILL PROVIDE ANOTHER FLARE UP LATER TONIGHT AND EARLY TUESDAY. THIS IS WHEN THE CORE OF THE ARCTIC AIR WILL FLOW IN AND WHEN THE WINDS WILL INCREASE. THIS IS HANDLED IN THE CURRENT FORECAST AND NO CHANGES WERE MADE TO THE HEADLINES. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 305 PM EST MON JAN 11 2016 COMMONLY WITH A DIGGING SYNOPTIC WAVE FOLLOWED BY AN ARCTIC AIRMASS WE TEND TO SEE WIDESPREAD IMPACTS...SOMETIMES SIGNIFICANT IMPACTS. THUS I WENT WITH A WARNING FOR MUCH OF THE LAKESHORE REGION AND A FEW INLAND COUNTIES AS WELL. THE LOW LEVEL FLOW BACKS THIS EVENING AS THE WAVE APPROACHES. THIS WILL ACT TO FOCUS THE MAIN BAND WEST OF KENT COUNTY DUE TO THE FLOW BECOMING SOUTHEAST OVER GRAND RAPIDS THIS EVENING. AS A RESULT IT APPEARS KENT COUNTY WILL MISS MUCH OF THIS INITIAL BANDING THIS EVENING...SO I DID NOT INCLUDE KENT IN THE WARNING. SOME NEWER MODELS ACTUALLY TAKE THE BANDING WEST OF MUSKEGON. THIS WOULD BE UNUSUAL. THE FLOW VEERS NORTHWEST BY 12Z TUE. THE TUESDAY MORNING COMMUTE LOOKS QUITE IMPACTED AS THE BANDS SHIFT AND HEAVY SNOW SHOWERS PERSIST. ALSO THE WINDS WILL INCREASE LATE TONIGHT ALONG THE LAKESHORE AND ALL LOCATIONS ON TUESDAY. BLOWING SNOW WILL INCREASE. I NOTICED THE LATEST HRRR RUC HAD GREATER THAN 35 KNOTS ON THE LAKESHORE. THIS COMBINED WITH HEAVY SNOW BANDS SHOULD SUPPORT NEAR WHITEOUT CONDITIONS. I EXTENDED THE HEADLINES INLAND. THE STRONGER WINDS WILL ACT TO CARRY THE SNOW SHOWERS WELL INLAND. THAT COMBINED WITH WIND GUSTS OVER 20 KNOTS WILL SUPPORT HAZARDOUS TRAVEL AT TIMES ON TUESDAY. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 305 PM EST MON JAN 11 2016 MAIN CONCERN CONTINUES TO BE WINTER WEATHER FRIDAY NIGHT. MOST MODEL GUIDANCE INDICATES LIMITED SNOWFALL WITH THIS EVENT DUE TO STRONG LOW LEVEL WARM ADVECTION AHEAD OF THE SURFACE LOW. AS NOTED IN THE PREVIOUS DISCUSSION...THE GFS HAS BEEN INCONSISTENT RUN TO RUN. HOWEVER THE GFS PARALLEL...GEM...AND FIM ALL FAVOR A WARMER SOLUTION MORE CONSISTENTLY. AS NOTED ALREADY...THE DETERMINISTIC ECMWF SHOWS GOOD RUN TO RUN CONSISTENCY WITH A LOW TRACK INTO THE OHIO VALLEY FAVORABLE FOR SNOW OVER THE FORECAST AREA. HOWEVER...THIS CONTROL RUN IS AN OUTLIER RELATIVE TO MOST ENSEMBLE MEMBERS THAT SHOW LOW TRACKS EITHER OVER LOWER MICHIGAN OR MUCH FARTHER SOUTHEAST. ALL THAT SAID...THERE ARE GOOD REASONS PUT FORTH IN THE PREVIOUS DISCUSSION TO NOT DISCOUNT THE DETERMINISTIC ECMWF ENTIRELY AND TO CONTINUE WATCHING THIS. WHAT IS MORE CERTAIN IS SIGNIFICANT PRECIPITATION FALLING ON A DECENT SNOWPACK BY THE END OF THE WEEK...RAISING CONCERNS FOR RIVERS THAT ARE DISCUSSED IN DETAIL IN THE HYDROLOGY SECTION. A FINAL CONCERN IS THE POTENTIAL FOR LIGHT FREEZING RAIN FRIDAY MORNING AS DEEP MOISTURE OVERSPREADS SURFACE AIR TEMPERATURES IN THE MID TO UPPER 20S. THIS COULD AFFECT THE FRIDAY MORNING COMMUTE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1232 AM EST TUE JAN 12 2016 POOR AVIATION CONDITIONS ARE EXPECTED MUCH OF THE NEXT 24 HOURS. MVFR AND IFR CONDITIONS WILL BE COMMON. A BAND OF HEAVY LAKE EFFECT SNOW WILL MOVE INLAND OFF OF LAKE MICHIGAN BETWEEN 06Z AND 09Z AND BRING LIFR CONDITIONS. SNOW SHOWERS WILL CONTINUE THE REMAINDER OF TONIGHT AND ALL DAY ON TUESDAY AS STRONG WESTERLY WINDS POUR INLAND OFF THE LAKE. WIND GUSTS OF 20-30 KNOTS WILL BE COMMON FROM LATE TONIGHT THROUGH THE DAY ON TUESDAY. BLOWING AND DRIFTING SNOW WILL BE COMMON AT ALL TAF SITES AS WELL ON TUESDAY. && .MARINE... ISSUED AT 405 PM EST MON JAN 11 2016 EXTENDED THE SCA INTO WEDNESDAY GIVEN INCREASING WINDS FROM THE NORTHWEST OVERNIGHT AND ASSOCIATED WAVE GROWTH. WE COULD EASILY COULD SEE SOME GUSTS OVER 35 OR 40 KNOTS AND WERE CONSIDERING A GALE WARNING WITH THIS FORECAST. THIS WILL BE SOMETHING TO WATCH FOR THE NEXT UPDATE. REGARDLESS...IT WILL GET QUITE UNPLEASANT ON LAKE MICHIGAN OVERNIGHT WITH SNOW AND FREEZING SPRAY. && .HYDROLOGY... ISSUED AT 1121 AM EST MON JAN 11 2016 MINOR RIVER FLOODING IS ONGOING AT HOLT...MAPLE RAPIDS AND IONIA. THE MAPLE RIVER AT MAPLE RAPIDS WILL CONTINUE TO GRADUALLY CLIMB OVER THE NEXT COUPLE OF DAYS BEFORE STABILIZING. HOLT AND IONIA HAVE BEGUN TO SHOW DECLINE. IMPROVEMENT SHOULD CONTINUE. MANY OTHER SITES THROUGH SOUTHWEST LOWER MICHIGAN ARE FLOWING WELL BELOW ACTION STAGE WHILE THE RISES AND HIGHER LEVELS ARE CONCENTRATED SOUTH AND EAST OF GRAND RAPIDS. THESE ARE THE SAME AREAS THAT WERE MORE SO AFFECTED BY MILD WEATHER AND RAINFALL EARLY IN THE WEEKEND. GOING FORWARD...OVERALL STABILIZATION OR IMPROVEMENT IS ANTICIPATED IN THE GRAND SCHEME OF THINGS. CONCERNS ARE MINOR...WHICH INCLUDE THE ACTIVE WEATHER PATTERN AND ARCTIC AIR MASS. PRECIPITATION CHANCES EXIST AT SOME POINT EACH DAY OF THE WEEK. THE GOOD NEWS IS THAT IT WILL ALL LIKELY BE IN THE FORM OF SNOW. THE DOWN SIDE WITH THESE TEMPERATURES IS THE RISING CONCERN FOR ICE FORMATION...ESPECIALLY IN CENTRAL LOWER MICHIGAN WHERE TEMPERATURES HAVE BEEN COLDER FOR A LONGER PERIOD OF TIME. THIS MAY BE THE WEEK WHERE WE SEE SOME ISSUES DEVELOP WITH MINOR ICE JAMMING...ESPECIALLY ON LOWER VOLUME RIVERS THAT FREEZE UP IN A QUICKER FASHION. IT IS NOTHING OF ALARM AT THIS POINT...BUT JUST SOMETHING TO KEEP AN EYE ON WITH OVERNIGHT TEMPS IN THE SINGLE DIGITS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ037-038- 043-044-050-056-064-071-072. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ057- 058-065-066-073. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ039- 040-045-046-051-052-059-067-074. LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR LMZ844>849. && $$ UPDATE...04 SYNOPSIS...MJS SHORT TERM...MJS LONG TERM...TJT AVIATION...DUKE HYDROLOGY...JAM MARINE...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1223 AM EST TUE JAN 12 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 439 PM EST MON JAN 11 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP MID/UPPER TROF EXTENDING FROM HUDSON BAY S THRU THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES REGION DOWNSTREAM OF A RIDGE EXTENDING ALONG THE W COAST OF CANADA THRU NE ALASKA. A RATHER VIGOROUS LOOKING SHORTWAVE IS DROPPING SE THRU ERN ND/NW MN. ANOTHER WEAKER SHORTWAVE TROF IS SWINGING S THRU NRN MANITOBA. THESE 2 FEATURES...ESPECIALLY THE FIRST SHORTWAVE...WILL DRIVE THE FCST IN THE SHORT TERM. WITH LATEST RAP ANALYSIS SHOWING 850MB TEMPS AROUND -20C ACROSS LAKE SUPERIOR... LES CONTINUES. HOWEVER...BACKING WINDS IN RESPONSE TO THE APPROACHING SHORTWAVE HAS RESULTED IN LES BANDS SHIFTING OFFSHORE OF MORE OF UPPER MI DURING THE DAY. ALTHOUGH CLOUD TOPS WERE UP TO AROUND 10KFT PER KMQT RADAR EARLIER TODAY...THE SHIFTING WINDS... LACK OF WELL ORGANIZED BANDS...AND A MORE SUPPRESSED DGZ TO THE LOWER PART OF THE CONVECTIVE LAYER HAVE KEPT SNOW ACCUMULATIONS IN CHECK. WITH LES ALREADY ONGOING ACROSS LAKE SUPERIOR...APPROACHING SHORTWAVE WILL RESULT IN THE NORMAL INTENSIFICATION OF LES TONIGHT/TUE MORNING. WINDS WILL CONTINUE TO BACK OVER THE NEXT FEW HRS IN RESPONSE TO THE STRONGER SHORTWAVE DROPPING SE THRU MN. THEN AS SFC TROF ASSOCIATED WITH SHORTWAVE MOVES S OVER LAKE SUPERIOR...A SHARPER CONVERGENCE ZONE WILL DEVELEOP THIS EVENING... RUNNING FROM NEAR THE APOSTLE ISLANDS TO N OF COPPER HARBOR THEN OVER TO MICHIPICOTEN ISLAND. CONVERGENCE ZONE SHOULD ALSO HELP LIFT DGZ A BIT HIGHER INTO THE CONVECTIVE LAYER TO INCREASE SNOW-TO-WATER RATIOS. ALTHOUGH THE TRACK OF THE SHORTWAVE IS A BIT FARTHER S THAN IDEAL (PEAK DEEP LAYER FORCING PASSES S OF LAKE SUPERIOR)...SYNOPTIC FORCING/DEEP MOISTURE WILL BE MORE THAN SUFFICIENT TO AID DEVELOPMENT OF HVY SNOW ALONG THE CONVERGENCE ZONE THAT WILL DROP S TONIGHT/EARLY TUE MORNING. WITH WINDS AT LEAST BRIEFLY SHIFTING NNW/N WITH PASSAGE OF SFC TROF...ALL LOCATIONS ALONG LAKE SUPERIOR WILL SEE AT LEAST A BRIEF BURST OF MDT/HVY SNOW. AREA FROM KIWD TO AROUND THE PORCUPINE MOUNTAINS AND FROM VCNTY OF MARQUETTE OVER THE GRAND MARAIS SHOULD SEE THE HEAVIEST SNOW WITH THE TROF PASSAGE. KEWEENAW COUNTY MAY ALSO END UP WITH SOME OF THE HEAVIEST SNOW DUE TO LONG FETCH HVY SNOW BAND INITIATING NEAR THE APOSTLE ISLANDS ALONG THE SFC TROF. LOCAL HIRES WRF RUN AND CANADIAN HIGH RES RUNS BOTH HAVE A HIGHER PCPN SIGNATURE IN KEWEENAW COUNTY. SO...LES ADVYS WILL REMAIN UP FROM GOGEBIC COUNTY THRU THE KEWEENAW. MARQUETTE/ALGER COUNTIES WILL ALSO BE ADDED. THE FACT THAT THE HVY SNOW/GUSTY WINDS ARRIVE JUST BEFORE AND DURING THE MORNING COMMUTE SHOULD LEAD TO ESPECIALLY DIFFICULT DRIVING CONDITIONS TUE MORNING FOR MARQUETTE/ALGER COUNTIES. MAY NEED TO CONSIDER ADDING NRN SCHOOLCRAFT/LUCE COUNTIES TO ADVY FOR TUE...BUT RIGHT NOW HAVE SNOW ACCUMULATIONS NEAR/JUST UNDER ADVY CRITIERIA. WIND PARALLEL LES BANDS WILL SET UP A FEW HRS AFTER THE TROF PASSES AND WILL THEN SLOWLY SHIFT THRU THE DAY TUE AS WINDS BACK WNW OVER WRN LAKE SUPERIOR AND NW OVER ERN LAKE SUPERIOR. TOTAL SNOW ACCUMULATIONS TONIGHT/TUE WILL GENERALLY RANGE FROM 2 TO 7 INCHES ALONG LAKE SUPERIOR WITH HIGHEST AMOUNTS VCNTY OF THE PORCUPINE MTNS AND JUST E OF MARQUETTE TO PICTURED ROCKS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 502 PM EST MON JAN 11 2016 NW WINDS WILL CONTINUE TUESDAY NIGHT WITH AN ADDITIONAL 2-5IN EXPECTED FROM THE PORCUPINE MTNS UP THROUGH CALUMET...AND THEN NE OF A LINE FROM MUNISING TO NEWBERRY. MOISTURE QUICKLY SHIFTS N WEDNESDAY AS A MORE W WIND TAKES OVER...LIMITING ADDITIONAL SNOW AMOUNTS TO THE KEWEENAW AND THEN RIGHT ALONG THE LAKE SUPERIOR SHORELINE FROM GRAND MARAIS TO WHITEFISH POINT. THIS WILL BE ALL WHILE THE MAIN SFC LOW EXITS FROM THE LOWER GREAT LAKES TO THE NEW ENGLAND STATES...AND RIDGING TRIES TO PUSH IN FROM THE SW. A TROUGH LOOKS TO LINGER ACROSS CENTRAL AND E LAKE SUPERIOR...ALONG WITH 850MB TEMPS OF -15 TO -22C...AND AN ELONGATED SHORTWAVE IN THE NW FLOW ALOFT...KEEPING LES GOING. KEPT ONLY CHANCE LES FOR WEDNESDAY NIGHT OVER THE KEWEENAW AS THE BEST MOISTURE EXITS AND SLIGHT RIDGING TAKES PLACE AT 500MB. THERE IS SOME POTENTIAL FOR WAA SNOW THURSDAY OUT AHEAD OF THE ORGANIZING SFC LOW TO OUR W AND SW. BETTER DETAILS ARE EXPECTED WITH THIS FEATURE...AND A QUICK BURST OF SNOW OVER THE S HALF OF THE CWA COULD BE POSSIBLE. TIMING FOR WHEN AND WHERE THE EJECTING SFC LOW WILL BE LATE THIS WEEK AND EARLY THIS WEEKEND ARE SILL A CONCERN. AT 18Z FRIDAY THE LOW IS CENTERED SOMEWHERE BETWEEN IL AND AR...AND COULD MOVE OVER THE GREAT LAKES AND OFF THE EASTERN SEABORARD BY 12Z SATURDAY. THIS QUICKER SOLUTION IS OFF THE 12Z ECMWF. A WETTER SOLUTION FOR US IS A SLOWER MORE W TRACK...SIMILAR TO THE GFS AND CANADIAN WITH THE THE LOW OVER IN AT 12Z SATURDAY. EITHER WAY...WE MAY HAVE A PERIOD OF N WINDS LATE CENTERING SOME SNOW SHOWERS ACROSS N CENTRAL UPPER MI FRIDAY NIGHT-SATURDAY. INCLUDED LIKELY POPS FOR SATURDAY...BEFORE TRANSITIONING TO A MORE NNW-NW FLOW PATTERN AGAIN SATURDAY NIGHT ON. FEW OTHER CHANGES WERE MADE TO A BLENDED SOLUTION IN THE DAYS 4-7 FCST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1220 AM EST TUE JAN 12 2016 A LOW PRES TROF WILL DROP S ACROSS LAKE SUPERIOR AND INTO UPPER MI...BRINGING A WSHFT FROM SW TO THE NNW. WHILE THERE MAY BE SOME -SN WITH MVFR/IFR CONDITIONS AHEAD OF IT...IN ITS WAKE...HEAVY LAKE EFFECT SNOW SHOWERS WILL BRING A PERIOD OF LIFR CONDITIONS TO ALL TERMINALS LATE TONIGHT INTO TUE MORNING. ALTHOUGH CONDITIONS WILL LIKELY REMAIN A PREVAILING LIFR AT KIWD/KCMX TUE MORNING...SLIGHT BACKING OF WINDS SHOULD SHIFT HEAVIER SNOW SHOWERS E OF KSAW LATE IN THE MORNING...RESULTING IN A RETURN OF MVFR CONDITIONS. KIWD WILL SEE A RETURN TO MVFR CONDITIONS TUE EVENING AS HEAVIER SNOW BANDS SHIFT NORTH AS WINDS BACK TO THE WEST WHILE FAVORABLE CONVERGENT WEST FLOW AT KCMX WILL MAINTAIN IFR TO POSSIBLE LIFR VSBYS AT TIMES IN LES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 502 PM EST MON JAN 11 2016 MUCH OF THIS PERIOD WILL BE MARKED BY AN AREA OF LOW PRESSURE OVER LAKE SUPERIOR. LOW PRESSURE INITIALLY ACROSS LAKE SUPERIOR AND WI WILL DEEPEN OVER S LAKE HURON BY TUESDAY MORNING. NNW WINDS TO 30 KTS EXPECTED TONIGHT...WITH WITH SOME GALE FORCE GUSTS UP TO 35 KTS. THE LOW WILL EXIT ALONG S QUEBEC AND THE NEW ENGLAND STATES LATE IN THE DAY...AS THE LINGERING TROUGH OVER LAKE SUPERIOR WEAKENS SLIGHTLY AND HIGH PRESSURE BUILDS INTO THE MISSISSIPPI VALLEY TUESDAY NIGHT INTO WEDNESDAY. ANOTHER ROUND OF COLD AIR SINKING IN WILL BRING ANOTHER PERIOD OF HEAVY FREEZING SPRAY TO W AND N CENTRAL LAKE SUPERIOR LATE TONIGHT AND TUESDAY. LOW PRESSURE OVER FAR N MANITOBA...AND AN ADDITIONAL LOW OVER S ALBERTA WEDNESDAY EVENING WILL COMBINE AND SETTLE ACROSS THE CENTRAL PLAINS THURSDAY NIGHT. EXPECT THE SURFACE LOW TO LIFT NORTHEAST ACROSS THE LOWER GREAT LAKES SATURDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY FROM 5 AM EARLY THIS MORNING TO 7 PM EST THIS EVENING FOR MIZ006. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY FROM 5 AM EARLY THIS MORNING TO 1 PM EST THIS AFTERNOON FOR MIZ005. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LSZ248-249-265-266. HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ241>244-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...KF
AREA FORECAST DISCUSSION
NWS DULUTH MN
345 AM CST TUE JAN 12 2016 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST TUE JAN 12 2016 NORTHWEST FLOW HAS BROUGHT ARCTIC AIR TO THE NORTHLAND. MOSTLY CLEAR SKIES HAVE HELPED TEMPERATURES DROP TO THE SINGLE DIGITS AND TEENS BELOW ZERO EARLY THIS MORNING. THE EXCEPTION IS FOR AREAS OF NW WISCONSIN DOWNWIND OF THE NW FLOW OVER LAKE SUPERIOR...WHERE THE LAKE EFFECT CLOUD COVER IS HELPING TEMPERATURES STAY SEVERAL DEGREES WARMER. A DEEP LOW OVER THE CENTRAL GREAT LAKES WILL SHIFT EAST INTO SOUTHERN ONTARIO TODAY. A SUBTLE UPPER LEVEL TROUGH OVER NORTHERN ONTARIO WILL PASS THROUGH THE NORTHLAND THIS MORNING. THE NW FLOW OVER THE LAKE WILL CONTINUE TO PRODUCE LAKE EFFECT SNOW SHOWERS ACROSS DOWNWIND AREAS OF NW WISCONSIN THROUGH AT LEAST THIS MORNING...AND POSSIBLY WELL INTO THIS AFTERNOON BEFORE ENOUGH DRIER AIR MOVES INTO THE REGION TO TAPER OFF ANY SIGNIFICANT SNOW SHOWERS. THE GREATEST ADDITIONAL SNOWFALL WILL BE FOR AREAS OF NORTHERN IRON COUNTY NEAR THE MICHIGAN BORDER NEAR IRONWOOD...WHERE AN ADDITIONAL 2 TO 4 INCHES WILL FALL THROUGH TODAY. NORTHERN BAYFIELD PENINSULA COULD GET AN ADDITIONAL 1 TO 2 INCHES. LEANED ON THE HIGHER SIDE OF PCPN GUIDANCE...INCLUDING THE WRF NMM AND ARW...AND THE SREF. THE NW WINDS OF 5 TO 15 MPH AND VERY COLD TEMPERATURES WILL CONTINUE TO RESULT IN WIND CHILL VALUES OF 20 TO 35 BELOW ZERO EARLY THIS MORNING. CONDITIONS WILL GRADUALLY IMPROVE AFTER SUNRISE...WITH AFTERNOON VALUES OF ABOUT 10 TO 20 BELOW ZERO. SOME MODELS ARE EXAGGERATING THE CLOUD COVER THIS MORNING...NOTABLY THE GFS AND ECMWF. THE SATELLITE AND OBSERVATIONS INDICATE VERY LITTLE...IF ANY...CLOUD COVER...SAVE FOR AREAS DOWNWIND OF LAKE SUPERIOR. THE HRRR SEEMS TO BE PERFORMING THE BEST...FOLLOWED BY THE NAM12/RAP13/CANADIANREGIONAL. LEANED ON THOSE MODELS FOR CLOUD TRENDS THROUGH THE REST OF THE DAY. THERE WILL LIKELY BE SOME AFTERNOON CUMULUS...ESPECIALLY OVER NORTHERN MINNESOTA. LEANED ON THE WARMER SIDE OF GUIDANCE BECAUSE THE COLDER GUIDANCE...SUCH AS THE GFS...MAY BE COLDER BECAUSE OF THE EXAGGERATED CLOUD COVER. HIGHS SHOULD REACH A FEW DEGREES ABOVE ZERO ACROSS THE SOUTH...AND APPROACH ZERO ACROSS THE NORTH AND WEST. A SURFACE RIDGE OF HIGH PRESSURE WILL BE JUST TO THE WEST AND SOUTH OF THE NORTHLAND TONIGHT. THE WIND SPEEDS WILL BE LIGHTER TONIGHT. THE COMBINATION OF CLEAR SKIES AND LIGHT WINDS THIS EVENING WILL ALLOW TEMPERATURES TO DROP QUICKLY THIS EVENING...DESPITE INCREASING HIGH LEVEL CLOUD COVER MOVING IN FROM THE WEST LATER TONIGHT. LEANED ON THE COLDER SIDE OF GUIDANCE...SUCH AS THE CANADIAN REGIONAL...AND NAM AND GFS MOS. OVERNIGHT LOWS WILL LIKELY BE WELL INTO THE TEENS BELOW ZERO FOR MOST OF THE NORTHLAND...BUT A BIT WARMER NEAR LAKE SUPERIOR. WIDESPREAD WIND CHILL VALUES OF 20 TO 30 BELOW ZERO ARE LIKELY...AND THE DAY SHIFT WILL ADDRESS THE NEED FOR AN ADVISORY ONCE THE ADVISORY FOR THIS MORNING COMES TO AN END. THE INCREASING CLOUD COVER LATE TONIGHT WILL BE ASSOCIATED WITH AN APPROACHING SHORTWAVE AND SUBTLE WARM FRONT ON WEDNESDAY FROM THE WEST. MOST OF THE MODELS ARE INDICATING THIS WAVE WILL BRING VERY MINIMAL AMOUNTS OF PCPN TO THE SW AND SOUTHERN FORECAST AREA LATE WEDNESDAY MORNING AND THROUGH THE AFTERNOON. THE HIGH SNOW TO LIQUID RATIOS OF THE SNOWFALL WILL MAKE IT EASY FOR THIS SHORTWAVE TO PRODUCE A TENTH OR TWO OF AN INCH...DESPITE THE MINIMAL PCPN. NOT ONLY WILL WARMER AIR MOVE INTO THE REGION WEDNESDAY...BUT THE CLOUD COVER WILL HELP INSULATE THE NORTHLAND. TEMPERATURES SHOULD FINALLY REACH THE POSITIVE SINGLE DIGITS AND TEENS AFTER THE RECENT DAYS OF MUCH COLDER THAN NORMAL TEMPERATURES. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 345 AM CST TUE JAN 12 2016 WEDNESDAY NIGHT THROUGH THURSDAY EVENING A NEW SHORTWAVE IS EXPECTED TO SWEEP ACROSS THE AREA...INTERACTING WITH A STRONG BAROCLINIC ZONE WHICH EXTENDS FROM SOUTHERN SASKATCHEWAN SOUTHEAST ACROSS MINNESOTA TO LOWER MICHIGAN. THIS SHOULD BRING A PERIOD OF SNOW ACROSS THE FORECAST AREA MAINLY ON THURSDAY...MAINLY ALONG AND SOUTH OF THE HIGHWAY 2 CORRIDOR. MODELS ARE STILL STRUGGLING WITH THE TIMING AND TRACK OF THIS WAVE...AND WE MAY SEE SOME ADJUSTMENTS IN THE NEXT FEW FORECAST CYCLES BEFORE CONFIDENCE INCREASES. TEMPERATURES TO BE NEAR TO BELOW NORMAL THROUGH THIS PERIOD WITH THE CLOUD COVER KEEPING THINGS MODERATED DESPITE THE STRONG NORTHWEST FLOW. THE NEXT POTENTIAL FOR A STRONGER STORM SHOULD AFFECT THE MIDWEST FRIDAY THROUGH SATURDAY OR SUNDAY. MODELS ARE STILL SHOWING LARGE DIFFERENCES BETWEEN MODELS AND HAVE VERY LOW CONFIDENCE IN THIS PORTION OF THE FORECAST. THE DIFFERENCES ARE MAINLY IN THE STRENGTH AND POSITION OF THE UPPER TROUGH AXIS THAT MOVES THROUGH FRIDAY/FRIDAY NIGHT...AND THE ASSOCIATED SURFACE FEATURES WHICH RANGE FROM HAVING THE STRONG SURFACE LOW OVER MISSOURI TO LAKE MICHIGAN FRIDAY AT 18Z. VARIABILITY REMAINS HIGH IN THE ENSEMBLES AS WELL...AND WOULD EXPECT THIS TO CONTINUE UNTIL THE MIDDLE OF THE WEEK WHEN THE UPPER LEVEL SHORTWAVE FINALLY COMES ONTO THE WEST COAST TO BE SAMPLED BY THE UPPER AIR NETWORK. HAVE KEPT THE LOW CHANCE POPS GOING THROUGH THE PERIOD WITH LAKE EFFECT SNOWS INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE NEAR NORMAL TO START OUT...GETTING COLDER AGAIN LATER IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1140 PM CST MON JAN 11 2016 CONDITIONS HAVE IMPROVED TO VFR QUICKLY THIS EVENING ACROSS MUCH OF NORTHEAST MINNESOTA AND WILL ALSO IMPROVE WELL INLAND OVER NORTHWEST WISCONSIN. THERE STILL MAY BE SOME BRIEF MVFR CEILINGS BUT THEY WILL BE SHORT LIVED. LAKE EFFECT SNOW ALONG THE SOUTH SHORE...ESPECIALLY ACROSS NORTHERN IRON COUNTY...WILL RAMP UP TONIGHT AND MVFR CEILINGS WILL EXTEND INLAND. WINDS HAVE TURNED TO NORTHWEST AND THEY WILL BE GUSTY AT TIMES TONIGHT. EXPECT THE WIND TO BACK TO WEST TO SOUTHWEST LATE IN THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DLH 0 -11 10 5 / 0 0 20 20 INL -2 -17 6 -4 / 0 0 10 10 BRD 2 -15 15 9 / 0 0 20 20 HYR 3 -15 10 7 / 0 0 30 20 ASX 5 -10 11 7 / 30 0 20 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR WIZ001>003-006>009. LAKE EFFECT SNOW ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR WIZ004. MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ010>012-018>021- 025-026-033>038. LS...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR LSZ121- 146>148. SMALL CRAFT ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR LSZ140-141. && $$ SHORT TERM...GROCHOCINSKI LONG TERM...LE AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1058 PM CST MON JAN 11 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 300 PM CST MON JAN 11 2016 LIGHT SNOW AT MID AFTERNOON PUSHING INTO CENTRAL MINNESOTA WILL ADVANCE QUICKLY EAST-SOUTHEAST THROUGH THIS EVENING AS A WAVE OF LOW PRESSURE MOVES ALONG THE ARCTIC FRONT. MUCH OF THE ACCUMULATING SNOW (AROUND AN INCH) REMAINS FOCUSED ALONG AND NORTH OF I-94 WITH AMOUNTS DWINDLING TO A FEW TENTHS ONCE YOU REACH THE MINNESOTA RIVER VALLEY. A CONCERN GOING FORWARD THROUGH THE EVENING IS THE AMOUNT OF BLOWING SNOW THAT WILL OCCUR ACROSS WEST CENTRAL MINNESOTA AS STRONG PRESSURE RISES FOLLOW THE ARCTIC WAVE. RAP PROFILE DATA AT KMOX IS A LITTLE DISCONCERTING. THE PROFILE THROUGH THE EVENING IS SATURATED FROM THE SFC-700MB IN THE DENDRITIC GROWTH ZONE WHILE THE WIND PROFILE SHOWS 25 KNOTS JUST OFF THE SURFACE WITH 33 KNOTS AT THE TOP OF THE CHANNEL. OUR NEIGHBORS TO THE WEST WERE NOT TOO CONCERNED DUE TO THE LACK OF SNOW ACCUMULATION EXPECTED BEFORE THE STRONG WINDS ARRIVE. THEREFORE...NO ADVISORIES PLANNED AT THIS TIME BUT THIS WILL NEED TO BE WATCHED. ON OUR END...INDICATED AREAS OF BLOWING SNOW INTO THE EARLY MORNING HOURS OF TUESDAY. KEPT LOWS TONIGHT AND HIGHS TUESDAY ON THE COLD SIDE BASED ON RECENT VERIFICATION. THIS RESULTS IN ALL SITES BETWEEN 5 AND 10 DEGREES BELOW ZERO TONIGHT WITH HIGHS TUESDAY FROM ZERO TO 5 ABOVE. THE WIND CHILL ADVISORY ISSUED EARLIER TODAY FOR THE FA LOOKS GREAT GIVEN THE EXPECTED TEMPERATURES AND WIND SPEEDS TONIGHT AND EARLY TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 PM CST MON JAN 11 2016 THE BEST WAY TO SUM UP THE NEXT SEVERAL DAYS WOULD BE COLD WITH OCCASIONAL SNOW SHOWERS. A FAIRLY SIGNIFICANT WINTER STORM WILL DEVELOP ACROSS THE MIDWEST ON FRIDAY/SATURDAY...BUT AT THIS TIME IS APPEARS THE MAJORITY OF THE ACCUMULATING SNOW WILL FALL SOUTHEAST OF THE FORECAST AREA. AT THE START OF THE PERIOD TUESDAY NIGHT NORTHWEST FLOW WILL BE IN PLACE...WITH SLIGHT H850 WARM AIR ADVECTION. A NORTHWEST/SOUTHEAST TEMPERATURE GRADIENT WILL LAY OUT ACROSS THE REGION...AND THIS WILL BE THE FOCUS FOR A BAND OF LIGHT SNOW THAT WILL DEVELOP ON WEDNESDAY MAINLY ALONG AND NORTH OF I-94. THIS BAND OF SNOW WILL SLOWLY SHIFT EASTWARD THURSDAY NIGHT. MEANWHILE AND UPPER LEVEL WAVE WILL MOVE FROM THE TEXAS PANHANDLE UP TOWARDS THE OHIO RIVER VALLEY. AS IT DOES SO...A SURFACE LOW PRESSURE SYSTEM WILL DEVELOP ACCOMPANIED BY A BAND OF HEAVY SNOW ON THE COLD SIDE OF THE PRECIPITATION SHIELD. THERE IS STILL A CONSIDERABLE AMOUNT OF UNCERTAINTY WITH THIS SYSTEM SINCE THE EXACT TRACK DEPENDS ON THE INTERACTION OF BOTH THE NORTHERN AND SOUTHERN JET STREAMS. FOR THIS REASON...DID NOT INCREASE POPS ABOVE THE BLENDED MODEL GUIDANCE. IT STILL LOOKS LIKE THE BEST CHANCE FOR A FEW INCHES OF ACCUMULATING SNOW WOULD BE FROM ALBERT LEA UP THROUGH EAU CLAIRE WI. LOOKING AHEAD...ANOTHER BLAST OF ARCTIC AIR WILL ARRIVE IN THE WAKE OF THIS STORM...WITH TEMPERATURES FALLING BACK BELOW ZERO EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1057 PM CST MON JAN 11 2016 THE CLOUDS AND LIGHT SNOW HAS RAPIDLY DIMINISHED AND THERE ARE ONLY A FEW POCKETS OF CLOUDS AND LIGHT SNOW REMAINING. VFR WILL BE THE DOMINATE FLIGHT CATEGORY TONIGHT OUTSIDE OF KRWF...WHICH IS STILL SEEING BLOWING SNOW. THAT WILL CONTINUE FOR THE NEXT 2-4 HOURS...BUT WINDS WILL GRADUALLY DIMINISH IN WESTERN MN. NEARLY CLEAR SKIES ARE EXPECTED TUESDAY. KMSP... JUST ISOLATED FLURRIES REMAIN...BUT LITTLE ADDITIONAL AVIATION WEATHER CONCERNS REMAIN THROUGH THE MORNING RUSH. SHOULD REMAIN NEARLY CLEAR ON THE SKY COVER. /OUTLOOK FOR KMSP/ WED...VFR. WINDS SW 5-10 KTS. THU...VFR. WINDS SE 5-10 KTS. FRI...VFR. MVFR/-SN POSSIBLE. WINDS N 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST TUESDAY FOR WIZ014>016- 023>028. MN...WIND CHILL ADVISORY FROM 3 AM TO NOON CST TUESDAY FOR MNZ053- 060>063-067>070-073>078-082>085-091>093. WIND CHILL ADVISORY UNTIL NOON CST TUESDAY FOR MNZ041>045- 047>052-054>059-064>066. WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR MNZ064-065- 067-073>075-082>085-091>093. && $$ SHORT TERM...RAH LONG TERM...JRB AVIATION...CLF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
333 AM CST TUE JAN 12 2016 .SYNOPSIS... ISSUED AT 333 AM CST TUE JAN 12 2016 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A BROAD TROUGH OF LOW PRESSURE CENTERED ACROSS THE EASTERN HALF OF THE CONUS. LOW PRESSURE WAS LOCATED ACROSS HUDSON BAY...WITH A SECONDARY LOW OVER QUEBEC. FURTHER WEST...A RIDGE EXTENDED FROM THE DESERT SW...NWD INTO IDAHO...WESTERN MT...AND INTO BRITISH COLUMBIA AND THE YUKON. AT THE SURFACE...AN ARCTIC COLD FRONT EXTENDED ROUGHLY FROM WEST OF VALENTINE...TO JUST NORTHEAST OF BROKEN BOW. INVOF THE FRONT...LIGHT SNOW FELL EARLIER THIS EVENING AND FLURRIES CONTINUE ROUGHLY ALONG A LINE FROM VALENTINE TO NORTH OF BROKEN BOW. RADAR RETURNS OVER THE PAST COUPLE OF HRS HAVE SHOWN A DECREASE IN COVERAGE...AS WELL AS INTENSITY OF SNOWFALL. THIS IS SUPPORTED BY SFC OBS AT KVTN...WHICH HAD VISBYS OF AROUND 5SM AT MIDNIGHT...AND 7SM CURRENTLY. EVEN WITH THE ARCTIC FRONT DRAPED ACROSS THE NORTHEASTERN CWA...TEMPS WERE RELATIVELY MILD TONIGHT THANKS TO THE ABUNDANT CLOUD COVER ALONG THE FRONT. SOUTHWEST OF THE FRONT...UNDER CLEAR SKIES...READINGS WERE MILD AS WELL. TEMPERATURES AS OF 3 AM CST RANGED FROM THE TEENS OVER NORTH CENTRAL AND NORTHEASTERN PORTIONS OF THE FORECAST AREA...TO THE LOWER TO MID 20S OVER SOUTHWESTERN PORTIONS OF THE FORECAST AREA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CST TUE JAN 12 2016 TODAY AND TONIGHT...TEMPERATURES WILL BE THE MAIN FORECAST CHALLENGE OVER THE NEXT 24 HOURS. FOR THIS MORNING...BASED ON THE HRRR AND LATEST NAM12 SOLNS...MID LEVEL LIFT WILL COME TO AN END ACROSS THE CENTRAL CWA AROUND 12Z. CLOUDS WILL REMAIN...HOWEVER ANY APPRECIABLE THREAT FOR LIGHT SNOW/FLURRIES IS EXPECTED TO END BEFORE 12Z THIS MORNING. WILL LEAVE OUT MENTION OF THIS IN THE FCST...HOWEVER...WILL CONTINUE TO MONITOR THE SITUATION TOWARD DAY BREAK...AND MAY NEED TO HANDLE THIS WITH A NOW CAST OR TWO IF FLURRIES DO DECIDE TO PERSIST AFTER 12Z. FOR THE REMAINDER OF TODAY...THE FRONTAL BOUNDARY WILL LIFT NORTHEAST AS A WARM FRONT...BECOMING ORIENTED ACROSS THE FAR NORTHEASTERN CWA BY 21Z THIS AFTERNOON. HIGHS WILL VARY WIDELY TDY WITH THE FRONT ANCHORED OVER NERN PORTIONS OF THE CWA. HIGHS WILL RANGE FROM AROUND 20 IN THE FAR NORTHEASTERN CWA...TO THE LOWER 40S IN THE FAR SOUTHWEST. WITH RESPECT TO HIGHS TDY...FOLLOWED THE WARMER MAV GUIDANCE...AS IT HAS HAD A MUCH BETTER TRACK RECORD OF VERIFYING OVER THE PAST COUPLE OF DAYS. FOR TONIGHT...THE WARM FRONT WILL LIFT FURTHER NORTHEAST OF THE AREA. COMPARED TO THE LOWS ATTM IN THE 20S...CLEARING SKIES AND LIGHT WESTERLY WINDS...WILL LEAD TO LOWS TONIGHT IN THE TEENS...WHICH IS STILL 5 TO 10 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 333 AM CST TUE JAN 12 2016 MID RANGE...WEDNESDAY AND THURSDAY...500HPA RIDGE AXIS TO BEGIN THE PERIOD AND BREAKS DOWN BY THE END. MODELS SHOW STRONG WAA AT 850HPA ACROSS THE FORECAST AREA WEDNESDAY WITH 5 TO 7C AT 00Z THU...WHICH SHOULD BE ENHANCED BY DOWNSLOPING. ADJUSTED MAX TEMPS UP A DEGREE OR TWO...WHICH IS STILL UNDERCUTTING THE MAV AND ECM BY A FEW DEGREES. GIVEN MOSTLY CLEAR CONDITIONS AND WESTERLY 20 TO 30 KTS AT 850HPA...CURRENT FORECAST HIGHS ARE PROBABLY TOO COOL. COLD FRONT DROPS SOUTH ACROSS THE AREA THURSDAY AFTERNOON AND EVENING...BUT ENOUGH CLEARING AND MIXING EARLY IN THE DAY WILL ALLOW HIGHS IN THE 40S EAST OF THE PANHANDLE. BETTER MOISTURE PROFILES ARE THU NIGHT INTO FRIDAY...SO INCLUDED -SN AFTER 00Z UNTIL 12Z. SOME SATURATION MAY OCCUR EARLIER ACROSS NORTHWEST NEBRASKA...AND DEPENDING ON TEMPS...PRECIP MAY FALL AS RAIN. FRONTOGENESIS APPEARS STRONGEST ACROSS THE SANDHILLS...BUT THE WINDOW FOR SATURATION AND LIFT WITHIN THE DGZ IS RATHER SHORT...LIMITING QPF. LONG RANGE...FRIDAY THROUGH TUESDAY...IS CHARACTERIZED BY A SERIES OF WAVES AND COOLER TEMPERATURES. THE NEXT ROUND COMES IN LATE FRIDAY INTO EARLY SATURDAY. LOW LEVEL MOISTURE IS SUFFICIENT AS SIGNALED BY EXPANSIVE CLOUD COVER...BUT AGAIN THE WINDOW FOR LIFT AND FRONTOGENETICAL FORCING IS SMALL. THE MERDIONAL 250HPA JET ALSO PASSES THROUGH FAIRLY QUICKLY...NOT CONTRIBUTING MUCH UPPER LEVEL DIFFLUENCE DESPITE A 120KT JET STREAK. THE BEST CHANCE OF -SN IS GENERALLY WEST OF HIGHWAY 83 AND NOT EXPECTING MUCH PRECIPITATION. SATURDAY NIGHT THROUGH MONDAY...THE GFS AND ECM DIVERGE A BIT. THE ECM BRINGS A DISTURBANCE THROUGH EARLY SUNDAY WHILE THE GFS IS 24 HOURS LATER...THUS DELAYING THE STRONG CAA. 850HPA TEMPS ARE SIMILAR IN MAGNITUDE...AROUND -20C AT THE COOLEST POINT. DUE TO UNCERTAINTY IN THE TIMING...WENT MIDDLE OF THE ROAD FOR TEMPS AND HAVE SCHC -SN EARLY TO MID MONDAY ACROSS THE WEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1136 PM CST MON JAN 11 2016 A BACKDOOR COLD FRONT RECENTLY PUSHED THROUGH THE KVTN TERMINAL. MAINLY P6SM -SN WILL CONTINUE UNTIL 10Z WITH MVFR CEILINGS NEAR OVC025 AT TIMES 06Z-14Z...FOLLOWED BY VFR CEILINGS FCST. AT KLBF...VFR CONDITIONS WILL PERSIST. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...SNIVELY AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1258 AM EST TUE JAN 12 2016 .SYNOPSIS... A LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES WILL BRING SNOW TO THE REGION TONIGHT INTO TUESDAY. COLD HIGH PRESSURE WILL BUILD INTO THE REGION ON WEDNESDAY...WITH DRIER CONDITIONS EXPECTED. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AN AREA OF SNOW HAS DEVELOPED IN SOUTH CENTRAL INDIANA AND IS LIFTING TOWARDS THE WHITEWATER VALLEY. THE RAP AND HRRR HAVE PICKED UP ON THIS AND THEY TAKE THIS AREA NORTHEAST THROUGH THE MIAMI VALLEY AND INTO NORTH CENTRAL OHIO. AFTER THIS PASSES THE LARGER AREA OF SNOW ASSOCIATED WITH THE FRONTOGENESIS IS THEN FORECAST TO DROP INTO THE FA. STILL LOOKING AT A COUPLE OF INCHES OF SNOW BEFORE MORNING IN THE NORTH AND AN INCH OR LESS IN THE SOUTH. TEMPERATURES WILL RISE FOR A GOOD PART OF THE NIGHT...REACHING THE UPPER 20S..BEFORE THE COLD AIR BEGINS TO RUSH IN FROM THE NW. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... AS THE INFLUENCE FROM THE SOUTHERN SURFACE RIDGE MOVES EAST OF THE REGION...SURFACE LOW PRESSURE IS BEGINNING TO DEVELOP IN THE UPPER MISSISSIPPI VALLEY. AS THIS LOW MOVES EAST AND STRENGTHENS...AN ARCTIC COLD FRONT WILL BEGIN TO QUICKLY MOVE OUT OF THE NORTHERN PLAINS...BRINGING A NOTABLE CHANGE IN AIR MASS TO THE GREAT LAKES AND OHIO VALLEY FOR TUESDAY. A WEAK SHORTWAVE WILL BE MOVING EAST INTO THE SOUTHERN GREAT LAKES AND NORTHERN OHIO VALLEY THIS EVENING...STRENGTHENING THE WARM ADVECTION FLOW (85OMB SPEED CONVERGENCE) AND ISENTROPIC ASCENT OVER THE REGION. IN RESPONSE...SNOW IS EXPECTED TO DEVELOP IN NORTHERN ILLINOIS AND NORTHERN INDIANA...SPREADING INTO THE NORTHWESTERN SECTIONS OF THE ILN FORECAST AREA BEFORE MIDNIGHT. AS THIS OCCURS...A STRONGER WAVE AND JET STREAK WILL BE QUICKLY MOVING OUT OF MANITOBA. THIS WILL EVENTUALLY ACT TO ENHANCE THE FIRST WAVE...ALONG WITH THE QUICKLY STRENGTHENING SURFACE LOW...AND THE PUSH OF COLD AIR ALONG THE DEVELOPING ARCTIC FRONT. THE MAJORITY OF ACCUMULATING SNOW IS EXPECTED TO DEVELOP ALONG AND AHEAD (PERHAPS WELL AHEAD) OF THE SURFACE FRONTAL BOUNDARY...IN RESPONSE TO FRONTAL FORCING ALOFT...AND FAVORABLE LEFT-EXIT JET POSITIONING. THE LACK OF WELL-FOCUSED FORCING IS ONE POTENTIAL LIMITING FACTOR FOR THIS EVENT...WITH NO REAL ANTICIPATION OF ANY BANDING. ANOTHER LIMITING FACTOR IS THE UNIMPRESSIVE MOISTURE PROFILES...WITH MOST OF THE ATMOSPHERIC MOISTURE CONFINED BELOW 700MB...AND ONLY INTERMITTENTLY FULLY SATURATED. MODEL SOUNDINGS DO INDICATE THE POTENTIAL FOR SLOWLY-COOLING PROFILES THROUGH THE DENDRITIC GROWTH ZONE FOR AT LEAST A FEW HOURS DURING THE EVENT...WHICH WOULD ALLOW FOR SOME BRIEFLY FAVORABLE CONDITIONS FOR EFFICIENT SNOW. WITH TEMPERATURES COOLING ALOFT...SNOW-TO-WATER RATIOS WILL GRADUALLY INCREASE...SOMEWHERE IN THE 14:1 TO 18:1 RANGE THROUGH MOST OF THE EVENT. THUS...IT MAY BE THE LACK OF AVAILABLE MOISTURE THAT KEEPS THIS FROM BEING A BIGGER SNOWFALL. ALL EXPECTATIONS ARE FOR A 6-8 HOUR PERIOD OF SNOW...WHICH MAY BE LIGHT AT TIMES...BUT WILL NONETHELESS ACCUMULATE ENOUGH TO CREATE HAZARDOUS CONDITIONS FOR THE TUESDAY MORNING COMMUTE. THE UPDATED SNOWFALL FORECAST RANGES FROM JUST OVER AN INCH IN THE SOUTHWESTERN CWA TO AROUND TWO A HALF INCHES IN THE NORTHEASTERN CWA. THESE NUMBERS FALL A LITTLE BELOW THE TRADITIONAL WINTER WEATHER ADVISORY CRITERIA...BUT EXPECTED IMPACTS FROM THE HORRIBLE TIMING (WITH RESPECT TO TRAVEL) AND INCREASING WINDS MADE THIS ADVISORY A FAIRLY EASY DECISION...ESPECIALLY WHEN THE AFTERNOON SNOW SHOWER / SNOW SQUALL THREAT (DISCUSSED BELOW) IS FACTORED IN. AS FOR THE WINDS...SOUTHWESTERLY FLOW WILL BECOME SLIGHTLY GUSTY DURING THE SAME TIME FRAME AS THE ACCUMULATING SNOW...BUT STRONGER WESTERLY WINDS WILL OCCUR ALONG AND BEHIND THE FRONT. GUSTS ARE EXPECTED TO PEAK OUT IN THE 30-35 KNOT RANGE FOR THE NORTHERN CWA...AND 25-30 KNOTS IN THE SOUTHERN CWA. THIS WILL NOT REQUIRE A WIND ADVISORY...BUT DOES FACTOR INTO THE WINTER WEATHER HAZARDS COVERED IN THE CURRENT HEADLINE. AGAIN...OVER-MIXING IN GFS BOUNDARY LAYER PROFILES LED TO THEIR EXCLUSION FROM CONSIDERATION IN DEVELOPING THE WIND GUST FORECAST. A SECONDARY THREAT WILL DEVELOP DURING THE LATE MORNING AND EARLY AFTERNOON...AS THE CHANGE OF AIR MASS BRINGS THE POTENTIAL FOR SNOW SHOWERS AND SNOW SQUALLS. ALONG AND BEHIND THE ARCTIC FRONT...THE BOUNDARY LAYER WILL BECOME WELL-MIXED IN A STRONG COLD ADVECTION PATTERN. THOUGH LARGER-SCALE MODELS CONTINUE TO DEPICT ONLY MEAGER QPF BEHIND THE PRIMARY MORNING AREA OF SNOW...SOUNDINGS CLEARLY INDICATE THE FAVORABLE CONDITIONS FOR SNOW SHOWER DEVELOPMENT...ESPECIALLY DURING THE LATE MORNING AND EARLY AFTERNOON. AHEAD OF THE POTENTIAL VORTICITY ANOMALY...WEAK/SHALLOW CONVECTIVE INSTABILITY IS EXPECTED TO DEVELOP (AT LEAST PARTIALLY) WITHIN THE DENDRITIC GROWTH ZONE...WITH CONSISTENTLY COOLING 850MB TEMPS. IN COMPARISON TO THE MORE SIGNIFICANT SNOW SQUALL DAYS IN THE ILN FORECAST AREA...THIS ONE IS A LITTLE WEAKER WITH THE PV ANOMALY...AS WELL AS THE STRENGTH OF THE LOW-LEVEL WIND FLOW. NONETHELESS...CONDITIONS ARE FAVORABLE FOR WIDESPREAD FLURRIES AND SCATTERED SNOW SHOWERS...WITH THE POTENTIAL FOR A FEW HEAVIER BANDS / SNOW SQUALLS TO DEVELOP. WRF-NMM/WRF-ARW SIMULATED REFLECTIVITY FORECASTS WERE USEFUL IN ASSESSING THE EXPECTED SNOW SHOWER LAYOUT...THOUGH BOTH MODELS FOCUS THE ACTIVITY VERY CLOSE TO THE ARCTIC BOUNDARY...WHEN AT LEAST SOME SNOW SHOWER ACTIVITY SEEMS LIKELY TO CONTINUE A LITTLE BEYOND THAT. THE WINTER WEATHER ADVISORY TIMING WAS CONTINUED THROUGH THE AFTERNOON TO ACCOUNT FOR THIS POSSIBILITY...AND THE THREAT FOR ISOLATED POCKETS OF REDUCED VISIBILITIES AND GUSTY CONDITIONS. WITH COLD ADVECTION CONTINUING THROUGH THE DAY AND INTO TUESDAY NIGHT...COMBINED WITH ANOTHER LAYER OF SNOW...VERY COLD CONDITIONS ARE EXPECTED BY EARLY WEDNESDAY MORNING. THE MIN TEMP FORECAST WAS ADJUSTED DOWN BY 2-3 DEGREES...WITH SINGLE DIGITS EXPECTED FOR THE ENTIRE FORECAST AREA. SOME COOL SPOTS IN THE NORTHERN CWA MAY APPROACH ZERO. WITH WINDS REMAINING IN PLACE AT AROUND 10 KNOTS...THE FAR NORTHERN CWA WILL HAVE WIND CHILLS OF AROUND -10F...LIKELY REQUIRING AN ADVISORY IN THE FUTURE. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... ARCTIC HIGH PRESSURE WILL TRAVERSE THE REGION ON WEDNESDAY. WAA INDUCED CLOUDS WILL OVERSPREAD THE REGION DURING THE DAY AHEAD OF AN ADVANCING WARM FRONT. HIGHS WILL REMAIN COLD...RANGING FROM THE UPPER TEENS NORTH TO THE MID 20S SOUTH. MODELS NOW SUGGEST THAT AN EMBEDDED S/WV IN THE NORTHWEST FLOW MAY BE A LITTLE MORE ROBUST AND SLIGHTLY FARTHER SOUTH FOR WEDNESDAY NIGHT. THIS WILL BRING A CHANCE OF LIGHT SNOW TO LOCATIONS GENERALLY ALONG AND NORTH OF I-70 WEDNESDAY EVENING INTO EARLY MORNING AS THE ASSOCIATED WARM FRONT PASSES THROUGH THE REGION. SNOW ACCUMULATIONS WILL BE LESS THAN AN INCH. OVERNIGHT LOWS WILL BE FAIRLY STEADY FROM WEDNESDAYS HIGHS AND MAY EVEN RISE SOME...ESPECIALLY ACROSS OUR SOUTHWEST CWFA. THURSDAY WILL BE AN IN BETWEEN DAY IN TERMS OF WEATHER SYSTEMS WITH GENERALLY PARTLY CLOUDY SKIES AND WARMER TEMPERATURES. HIGHS WILL RANGE FROM THE UPPER 30 NORTH TO THE MID 40S SOUTH. FOR THE REMAINDER OF THE EXTENDED...MODELS ARE STILL STRUGGLING ON HOW THE SOUTHERN BRANCH OF THE JET STREAM WILL INTERACT WITH THE NORTHERN BRANCH...EITHER PHASING OR NOT PHASING. THIS FORECAST PACKAGE RELIES ON WPC EXPERTISE WHICH SUGGESTS THAT THE PREVIOUS AND CURRENT ECMWF MODEL MAY BE HANDLING A LOW PRESSURE SYSTEM THAT IS FORECAST TO MOVE NORTHEAST THROUGH THE GREAT LAKES AND OHIO VALLEY FRIDAY INTO SATURDAY THE BEST. AS A RESULT...UPPER LEVEL ENERGY EJECTING OUT OF THE SOUTHERN PLAINS WILL BRING MOISTURE NORTHWARD INTO THE AREA FRIDAY INTO FRIDAY NIGHT. IT NOW APPEARS IT WILL BE WARM ENOUGH FOR THE PRECIPITATION TO BEGIN AS RAIN AND REMAIN RAIN THROUGH THE DAY FRIDAY. BY FRIDAY NIGHT INTO SATURDAY...COLDER AIR FILTERING INTO THE REGION ON THE BACK SIDE OF THE LOW WILL TRANSITION THE RAIN TO SNOW SHOWERS. FOR THE UPCOMING WEEKEND...THERE WILL BE A LINGERING THREAT FOR SNOW SHOWERS AS MUCH COLDER AIR MOVES ACROSS THE WARMER WATERS OF THE GREAT LAKES. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... SNOW WILL OCCUR ACROSS THE REGION THROUGH THE FIRST HALF OF THE TAF PERIOD. EXPECT TEMPORARY IFR VISIBILITIES FROM KDAY TO KCMH/KLCK WITH VFR PREVAILING FURTHER SOUTH EARLY IN THE PERIOD. CEILINGS WILL LOWER TO MVFR AREA WIDE. AN ARCTIC FRONT WILL SWEEP ACROSS THE TERMINALS BETWEEN 12Z AND 18Z. SNOW SHOWERS SHOULD INTENSIFY ALONG AND IMMEDIATELY AHEAD OF THIS FRONT WITH LATEST INDICATIONS SUGGESTING THE GREATEST IMPACT TO BE AT KCVG/KLUK. SOUTHWEST WINDS WILL SLOWLY INCREASE AHEAD OF THE FRONT. WINDS WILL SHIFT TO WEST OR WEST NORTHWEST AND GUST AROUND 30 KT AFTER THE FRONT PASSES. COULD BE SOME LINGERING SNOW SHOWERS. MVFR CEILINGS WILL EVENTUALLY LIFT TO VFR. GUSTINESS IN THE WIND WILL DIMINISH AROUND OR AFTER 00Z WITH SUSTAINED SPEEDS SLOWLY DIMINISHING AS WELL. SOME CLEARING MAY START TO WORK IN LATE IN THE PERIOD. OUTLOOK...MVFR CIGS AND VSBYS ARE POSSIBLE WEDNESDAY NIGHT INTO THURSDAY MORNING AND AGAIN FRIDAY INTO SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ045- 046-054>056-063>065-070>074-077-078-080-082. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR OHZ026-034-035-042>044-051>053-060>062. WINTER WEATHER ADVISORY FROM 5 AM EARLY THIS MORNING TO 7 PM EST THIS EVENING FOR OHZ079-081-088. KY...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ089>093. WINTER WEATHER ADVISORY FROM 5 AM EARLY THIS MORNING TO 7 PM EST THIS EVENING FOR KYZ094>100. IN...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ058- 059-066-073>075-080. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR INZ050. && $$ SYNOPSIS...HATZOS/SITES NEAR TERM...SITES SHORT TERM...HATZOS LONG TERM...HICKMAN AVIATION...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1033 AM EST TUE JAN 12 2016 .SYNOPSIS... HIGH PRESSURE OVER THE SOUTHEASTERN STATES WILL LOSE ITS INFLUENCE ON OUR AREA AS LOW PRESSURE MOVES ACROSS THE GREAT LAKES AND INTO SOUTHEASTERN CANADA. A STRONG COLD FRONT ASSOCIATED WITH THIS LOW WILL CROSS THE REGION LATE THIS AFTERNOON AND EARLY EVENING. HIGH PRESSURE WILL BUILD BACK INTO THE AREA ON WEDNESDAY, PERSIST INTO THURSDAY, AND WEAKEN ON FRIDAY. COMPLEX LOW PRESSURE WILL IMPACT THE NORTHERN MID-ATLANTIC AND NORTHEASTERN UNITED STATES ON SATURDAY AND SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... TIMING OF THE INCOMING PRECIP FOR OUR AREA ASSOCIATED WITH A COLD FRONT APPROACHING FROM THE WEST LOOKS PRETTY GOOD FOR A MID TO LATE AFTERNOON ARRIVAL ACCORDING TO THE HRRR AND RAP, BEFORE TAPERING OFF EARLY THIS EVENING. WE DID TRIM BACK POPS A BIT FOR SOUTHERN/EASTERN AREAS AS MOST OF THE SCATTERED RAIN/SNOW SHOWERS WILL BE FROM AROUND THE I-95 CORRIDOR AND TO THE NORTHWEST. PRIOR TO THIS AFTERNOON, THERE COULD BE A FEW FLAKES ACROSS THE POCONOS/NORTHWEST NJ AND NEARBY AREAS AS KHZL AND KAVP HAVE ALREADY REPORTED SOME PASSING LIGHT SNOW. OTHERWISE, WE USED THE LAV/LAMP GUIDANCE TO ADJUST HOURLY TEMPS/DEWPOINTS THROUGH THE MORNING TO EARLY AFTERNOON, MAINLY TO ACCOUNT FOR A SLIGHT FASTER RISE IN TEMPS ACROSS THE REGION. LOW PRESSURE WILL DEEPEN ACROSS THE GREAT LAKES REGION TODAY AND THEN MOVE UP INTO SRN CANADA TONIGHT. AN INCREASING SRLY FLOW OF MILDER AND MORE HUMID AIR WILL ARRIVE TODAY. INCREASING CLOUDS WILL BE FOUND OVER THE AREA THIS MORNING...AND THEN SOME SHOWERS WILL DEVELOP ACROSS PA AND PUSH THROUGH LATE THIS AFTERNOON AND EARLY THIS EVENING. POPS ARE HIGHEST NORTH/WEST WHERE THEY ARE LIKELY...THEN TAPERING OFF TO SLGT CHC S/E. TEMPERATURES WILL FAVOR RAIN TODAY...BUT WITH DRIER AND COOLER AIR ARRIVING LATE...A CHANGE TO SNOW SHOWERS WILL OCCUR OVER THE WRN AREAS...AND SPREAD EAST LATE. ACCUMS...AT MOST...WILL BE AROUND AN INCH OVER THE HIGHER ELEVATIONS UP NORTH. LOWER VSBYS ARE POSSIBLE IN SNOW SHOWERS LATER TODAY...BUT CONDITIONS WILL NOT LAST LONG ENOUGH TO WARRANT ANY WSW FLAGS ATTM. HIGHS TODAY WILL BE MILDER THAN MON...WITH MID 40S TO LOW 50S S/E AND 30S N/W. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... THE SFC COLD FRONT WILL BE EAST OF THE AREA TONIGHT. DRIER AND COLDER AIR WILL RETURN ON A GUSTY WEST WIND. WIND GUSTS WILL BE UP OVER 30 MPH AT TIMES...ESPECIALLY CLOSER TO THE COAST AND OVER THE HIGHER ELEVATIONS OF THE SRN POCONOS. LOW TEMPERATURES WILL DROP INTO THE TEENS UP NORTH AND LOW 20S ELSEWHERE. WIND CHILL LEVELS WILL BE IN THE SINGLE DIGITS AND TEENS BY MORNING. SKIES WILL BE MOSTLY CLOUDY EARLY...A FEW SNOW SHOWERS POSSIBLE ACROSS THE SRN POCONOS AND NRN NJ. SKIES WILL CLEAR OUR FROM W TO E OVERNIGHT. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... OVERVIEW...THE PERIOD STARTS WITH INTENSIFYING LOW PRESSURE OVER THE CANADIAN MARITIMES AND A STIFF NW FLOW IN ITS WAKE. SURFACE HIGH PRESSURE BEGINS TO BUILD ACROSS THE REGION ON WEDNESDAY AND PERSISTS INTO THURSDAY. A MID-LEVEL SHORT WAVE IS FORECAST TO MOVE ACROSS THE REGION LATE WEDNESDAY OR EARLY THURSDAY MORNING. THIS SHOULD BE FOLLOWED BY MID-LEVEL RIDGING ALONG MUCH OF THE ATLANTIC SEABOARD ON THURSDAY NIGHT INTO FRIDAY. THE RIDGE BEGINS TO BREAK DOWN LATER ON FRIDAY AS SURFACE LOW PRESSURE ENTERS INTO THE OHIO VALLEY. SECONDARY COASTAL LOW PRESSURE IS A POSSIBILITY ON SATURDAY AS THE MID-LEVEL TROF MOVES INTO THE MID-ATLANTIC AND NORTHEASTERN U.S. REGARDLESS, A WARM FRONT SHOULD PUSH THROUGH THE REGION FOLLOWED BY A COLD FRONT BY THE END OF THE WEEKEND. THE MID-LEVEL TROF COULD REMAIN ACROSS THE REGION INTO EARLY NEXT WEEK AS REINFORCING SHOTS OF ENERGY HOLD IT IN PLACE. PRECIP...SEVERAL SHOTS POSSIBLE THROUGH THE EXTENDED WITH THE BEST AND MOST WIDESPREAD CHANCE ON FRIDAY NIGHT AND SATURDAY. I INTRODUCED SOME ISOLATED SNOW SHOWERS ACROSS THE NORTHWEST ZONES ON WEDNESDAY MORNING IN THE STRONG NORTHWEST FLOW. GRIDS ARE PRECIP FREE FROM WEDNESDAY AFTERNOON THROUGH FRIDAY. LIKELY POPS FRIDAY NIGHT AND SATURDAY AS THE COMPLEX LOW PRESSURE AND WARM FRONT WORKS INTO THE REGION. BASED ON TEMPS FOR FRIDAY NIGHT, A WINTRY MIX IS POSSIBLE DOWN TO THE LEHIGH VALLEY AND MUCH OF NORTHERN NJ. WARMER AIR COMES IN ON SATURDAY AND CHANGES ALL THE PRECIP TO RAIN WITH THE EXCEPTION OF MAYBE CARBON, MONROE, AND SUSSEX NJ. COLD AIR COMES BACK IN ON SUNDAY AND CHANGES MOST OF THE SLIGHT CHANCE PRECIP TO FROZEN. I CONTINUE WITH SOME SLIGHT CHANCE POPS ACROSS THE NORTHERN ZONES SUNDAY NIGHT INTO MONDAY. PRECIP WOULD BE IN THE FORM OF SNOW. TEMPS...THE PERIOD WILL START WITH BELOW NORMAL TEMPS. WIND CHILLS MAY NOT GET OUT OF THE SINGLE DIGITS AND TEENS ANYWHERE ON WEDNESDAY. WE`LL MODERATE ABOUT 10 DEGREES OR SO ON THURSDAY. WE`LL GAIN ANOTHER 10 DEGREES OR SO FRIDAY. THE WARMEST DAY APPEARS TO BE SATURDAY WITH HIGHS RANGING FROM THE MID TO UPPER 30S NORTH AND WEST TO LOWER 50S SOUTH. WE THEN WILL FEEL THE EFFECTS OF A COLD FRONT. SUNDAY WILL DROP BELOW NORMAL AND NEXT MONDAY`S AIR TEMPERATURE COULD BE AS COLD AS WHAT WE SEE ON WEDNESDAY. WINDS...THE NORTHWEST WINDS ARE GOING TO BE QUITE NOTICEABLE ON WEDNESDAY...MAYBE GUST UP TO 30-35 MPH. WINDS WILL SETTLE SOME FOR THURSDAY, BUT REMAIN GUSTY OUT OF THE WEST. NO ISSUES ON FRIDAY. GUSTY WINDS ARE EXPECTED ONCE AGAIN ON SATURDAY AND SUNDAY WITH THE SINGLE OR DOUBLE BARREL LOW TRACKING THROUGH THE AREA. MONDAY LOOKS WINDY AS WELL BEHIND THE COLD FRONT. POTENTIAL IMPACTS...SEVERAL POSSIBILITIES THROUGH THE EXTENDED WITH AT LEAST ONE OF THE ABOVE ELEMENTS TOUCHING EVERYONE. SNOW SHOWERS COULD CAUSE SOME ISSUES ON THE WEEKEND. TEMPS(WIND CHILLS) WILL BE BRUTAL ON WEDNESDAY (AT LEAST FOR THIS WINTER) AND POTENTIALLY AGAIN NEXT MONDAY. ALSO GOING TO BE A WINDY PERIOD, BUT AS OF NOW, IT APPEARS WINDS WILL BE AT SUB WIND ADVISORY LEVELS. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS WILL BE ACROSS THE REGION MUCH OF TODAY AND TONIGHT. THERE IS THE POSSIBILITY FOR GUSTY SHOWERS (RAIN S/E AND SNOW N/W) LATE THIS AFTERNOON AND EARLY THIS EVENING. A COLD FRONT ATTACHED TO LOW PRESSURE TO THE NORTH WILL BRING THE LIFT NECESSARY FOR THESE SHOWERS. WE WILL MENTION THE POSSIBILITY OF LOWER CIGS/VSBYS (MVFR) IN A TEMPO GROUPS COVERING THE MOST LIKELY TIMES OF THE SHOWERS. WINDS WILL INCREASE FROM THE S/SW EARLY TODAY AND THEN SWITCH TO WRLY BEHIND THE FRONT. GUSTY WEST WINDS GUSTING 30-34 KTS EXPECTED TONIGHT BEHIND THE FRONT. OUTLOOK... WEDNESDAY...VFR WITH A WEST NORTHWEST WIND GUSTING 25 TO 35 KNOTS. WEDNESDAY NIGHT...MAINLY VFR. GUSTY W WIND TO 20 KT. THURSDAY...MAINLY VFR. GUSTY W WIND TO 25 KTS. FRIDAY...VFR. LIKELY CIGS WILL DETERIORATE AT NIGHT. && .MARINE... TIMING FOR THE GALES ACROSS DEL BAY AND THE OCEAN WATERS LOOKS PRETTY GOOD...SO WE WILL CONTINUE THE PRESENT FLAGS AS THEY ARE. SFC LOW WILL DEEPEN ACROSS THE GREAT LAKES TODAY AND THEN HEAD DOWN THE ST. LAWRENCE VALLEY TONIGHT. A STRONG COLD FRONT WILL CROSS THE WATERS THIS EVENING. INCREASING SW WINDS THIS AFTERNOON WILL SHIFT TO WRLY/NWRLY THIS EVENING AND INCREASE TO GALE FORCE. SCT SHOWERS WITH THE FRONT THEN CLEARING BEHIND THE FRONT. OUTLOOK... WEDNESDAY...THE GALE WARNING HAS BEEN PUSHED INTO WEDNESDAY MORNING. AFTER THE GALE WARNING COMES DOWN, A BACK END SCA WILL BE NECESSARY. WEST WINDS WITH GUSTS TO 40 KTS ARE LIKELY EARLY THEN GRADUALLY DIMINISHING. WEDNESDAY NIGHT...A LINGERING SCA MAY STILL BE NEEDED, ESPECIALLY EARLY. THURSDAY THRU FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED. && .TIDES/COASTAL FLOODING... WILL KEEP AN EYE ON THE POSSIBILITY OF SOME BLOWOUT TIDES WEDNESDAY MORNING. DBOFS IS INDICATING THE POSSIBILITY WHILE THE ETSS IS NOT. LOOKS LIKE A QUICK SHOT IF ANYTHING WITH ONE LOW TIDE POSSIBLY BEING AFFECTED. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR ANZ450>455. GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST WEDNESDAY FOR ANZ430-431. && $$ SYNOPSIS...KRUZDLO NEAR TERM...KLINE/O`HARA SHORT TERM...O`HARA LONG TERM...KRUZDLO AVIATION...KRUZDLO/O`HARA MARINE...KRUZDLO/O`HARA TIDES/COASTAL FLOODING...KRUZDLO
AREA FORECAST DISCUSSION
NWS JACKSON KY
1104 AM EST TUE JAN 12 2016 .UPDATE... ISSUED AT 1104 AM EST TUE JAN 12 2016 SNOW EVENT GOT A LATE START...BUT IS UNDERWAY OVER THE NORTHERN PART OF THE FORECAST AREA. OBS...RADAR TRENDS...AND NEW 12Z MODEL DATA SUPPORT LIGHT ACCUMULATIONS OF AN INCH AND LOCALIZED TWO INCHES IN OUR NORTHERN COUNTIES TODAY. SNOW WILL BE INTERMITTENT IN NATURE...AND COULD BRIEFLY COME DOWN INTENSELY. SOME LIGHTNING HAS EVEN BEEN OBSERVED IN SNOW SHOWERS OVER SOUTHERN INDIANA THIS MORNING. FURTHER SOUTH...THE END RESULT IS MORE QUESTIONABLE. WITH AN ADVISORY ALREADY IN PLACE...WILL LEAVE IT...BUT JUST MENTION LOCALIZED ACCUMULATIONS UP TO AN INCH FROM LOCALIZED HEAVIER SNOW SHOWERS. UPDATE ISSUED AT 645 AM EST TUE JAN 12 2016 LIGHT SNOW AND FLURRIES ARE CROSSING MAINLY NORTHERN PARTS OF THE AREA WITH LITTLE IN THE WAY OF ACCUMULATIONS REPORTED. A MORE INTENSE BATCH OF SNOW WILL MOVE IN LATER IN THE MORNING. HAVE TIMED THIS BAND THROUGH IN THE GRIDS. ALSO UPDATED THE HOURLY T AND TD GRIDS PER THE LATEST CONDITIONS AND TRENDS...PARTICULARLY MILDER ON TEMPS DUE TO THE STRENGTHENING SOUTHWEST WINDS AHEAD OF THE FRONT. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 07Z SFC ANALYSIS SHOWS A DEEPENING AREA OF LOW PRESSURE MOVING THROUGH THE CENTRAL GREAT LAKES. THIS IS DRIVING AN ARCTIC COLD FRONT INTO THE NORTHWEST PORTION OF THE OHIO VALLEY EARLY THIS MORNING. CLOSER TO HOME...A DECENT PRESSURE GRADIENT EXISTS OVER KENTUCKY BETWEEN THE LOW TO THE NORTH AND HIGH PRESSURE ALONG THE GULF COAST. THIS IS ALREADY MANIFESTING IN SOME BREEZY SOUTHWEST WINDS THROUGH THE BLUEGRASS HELPING TO KEEP NIGHTTIME TEMPERATURES RELATIVELY MILD FOR MUCH OF THE AREA. WHILE MOST PLACES ARE SEEING LOW AND MID 30S FOR THE JKL CWA...A FEW SHELTERED EASTERN VALLEYS REMAIN IN THE MID 20S. WINDS ARE GUSTING OVER THE WESTERN PARTS OF THE AREA REACHING THE 25 TO 30 MPH RANGE AT TIMES. ALTHOUGH A DRY AIR MASS IS IN PLACE THE SOUTHERLY WINDS WILL TRY TO BRING IN MORE MOISTURE THROUGH THE FIRST PART OF THE MORNING AHEAD OF THE ARCTIC FRONT. MEANWHILE...DEW POINTS THROUGHOUT THE AREA ARE RUNNING IN THE UPPER SINGLE DIGITS TO MID TEENS NORTHEAST TO THE MIDDLE AND UPPER TEENS SOUTH. A DECK OF MID LEVEL CLOUDS COVER THE BULK OF EASTERN KENTUCKY WITH EVEN A FEW VERY LIGHT SNOW SHOWERS AND FLURRIES PASSING THROUGH. THE MODELS ARE IN EXCELLENT AGREEMENT WITH THE UPPER AIR PATTERN THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE CORE OF A FAIRLY DEEP TROUGH...THAT IS MOVING INTO THE OHIO VALLEY...TO PUNCH THROUGH KENTUCKY BY EARLY AFTERNOON. THIS IS DRIVEN BY A 135 TO 140 KT 300 MB JET ARCING INTO THE REGION THIS MORNING WITH A GOOD AMOUNT A UPPER LEVEL DIVERGENCE PROGGED TO PASS OVER EAST KENTUCKY BETWEEN 09 AND 21Z. IT WILL BE A QUICK HITTING MID LEVEL WAVE...THOUGH...AS BY 00Z IT WILL BE OFF THE MID ATLANTIC COAST ALLOWING HEIGHTS TO RELAX LOCALLY AND RISE INTO THE DAY WEDNESDAY. A COUPLE OF WEAKER WAVES DO FOLLOW IN NORTHWEST FLOW AND LOOK TO PASS ABOVE EAST KENTUCKY FOR WEDNESDAY. GIVEN THE GOOD MODEL MATCH-UP WILL FOLLOW SUIT BUT FAVOR THE SPECIFICS FROM THE HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS... ALONG WITH A HEALTHY DOSE OF CLIMATOLOGY FOR THESE SITUATIONS IN EASTERN KENTUCKY. SENSIBLE WEATHER WILL FEATURE A DYNAMIC AND ACTIVE WEATHER DAY AS AN ARCTIC BOUNDARY PASSES THROUGH THE CWA BY LATE IN THE AFTERNOON. WHILE LIGHT SNOW WILL BE POSSIBLE AHEAD OF THIS BOUNDARY...THE MAIN SHOW WILL BE JUST ALONG AND BEHIND IT AS IT HELPS TO MAXIMIZE THE MID LEVEL LAPSE RATES AND FIND JUST ENOUGH CAPE TO BECOME CONVECTIVE IN NATURE. GIVEN THE BACKGROUND PRESSURE AND HEIGHT GRADIENTS IN THE THE LOWER LEVELS OF THE ATMOSPHERE THE HIGHER WINDS ALOFT SHOULD BE ABLE TO BE TAPPED BY THE CONVECTIVE CELLS LEADING TO GUSTY WINDS AT THE SFC. THIS COMBINED WITH THE SNOW SHOWERS WILL MEAN RAPIDLY CHANGING VISIBILITY IN GUSTY SNOW SQUALLS. FINALLY...GIVEN THE COLD STARTING POINT FOR ROAD SFCS... EXPECT ANY SNOW THAT FALLS TO POTENTIALLY ACCUMULATE ON THE ROADS...WITH LIMITED HELP FROM INSOLATION DURING THE DAYLIGHT HOURS. SO...ALTHOUGH QPF WILL BE RATHER LIMITED WITH THIS FRONT... THE IMPACT FROM THESE LIGHT EVENTS CAN BE AS LARGER OR LARGER THAN BIGGER WINTER STORMS SO WILL CONTINUE TO HIT IT HARD WITH A WSW ADVISORY ACROSS THE BULK OF OUR CWA TODAY...STARTING EARLIER IN THE WEST AND LINGERING LONGER IN THE EAST. SNOW AMOUNTS SHOULD BE MAXIMIZED...WITH A POTENTIAL FOR UP TO 2 INCHES...IN THE NORTHERN PARTS OF THE CWA AND IN THE HIGHEST TERRAIN NEAR THE VIRGINIA BORDER. THE SNOW WILL END FROM WEST TO EAST IN THE EVENING...WITH A DROP OFF IN THE SQUALLINESS AFTER SUNSET. LOOK FOR A HINT OF UPSLOPE COMPONENT INTO THE NIGHT TO KEEP A SMALL THREAT OF SNOW SHOWERS AND FLURRIES GOING IN THE FAR EAST THROUGH EARLY WEDNESDAY MORNING...BUT ANY ADDITIONAL ACCUMULATIONS WILL BE MARGINAL AFTER THIS EVENING. CHILLY HIGH PRESSURE THEN SPREADS INTO THE STATE WITH LOW TEMPERATURES NEARING THE SINGLE DIGITS IN THE NORTHWEST BY DAWN WEDNESDAY. WINDS STILL BRISK WILL YIELD WIND CHILLS DOWN NEAR ZERO IN SPOTS AND MAINLY SINGLE DIGITS ELSEWHERE AT DAWN WEDNESDAY. READING WILL THEN STRUGGLE TO RISE OUT OF THE 20S ON WEDNESDAY DESPITE A RETURN OF SOME SUNSHINE. IN FACT...THE SUNSHINE WILL LIKELY BE LIMITED BY SOME MID AND HIGH LEVEL CLOUDS INBOUND FROM THAT NEXT...WEAKER...WAVE PASSING BY AT MID LEVELS. ACCORDINGLY...HAVE NOT ZEROED OUT POPS FOR LATER WEDNESDAY AS A COUPLE OF FLURRIES CANNOT BE RULED OUT FROM THIS FEATURE WHEN IT BRUSHES BY FROM WEDNESDAY AFTERNOON INTO THE EVENING. USE THE SHORTBLEND AS A STARTING POINT FOR TEMPERATURES AND DEW POINTS THROUGH THE EVENING WITH THE SUPERBLEND USED THEREAFTER. MADE ONLY MINOR ADJUSTMENTS FOR SOME TERRAIN DISTINCTIONS TONIGHT...AS THE GRIDS LOOKED REASONABLE. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF THE MOS...WHICH IS TYPICAL FOR THIS TYPE OF SITUATION. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 PERIOD WILL BEGIN WITH A MID LEVEL TROUGH MOVING ACROSS THE OHIO VALLEY WEDNESDAY NIGHT...WHILE PRECIP WILL BE POSSIBLE NORTH OF THE REGION ACROSS CENTRAL OH. WE WILL MAINLY SEE CLOUDS ASSOCIATED WITH THIS WAVE WEDNESDAY NIGHT HERE IN EASTERN KY. ON THURSDAY HIGH WILL BE PARKED TO THE SE AND WILL INTRODUCE RETURN FLOW TO THE REGION. THIS WILL ALLOW TEMPS TO MODERATE THROUGH THE END OF THE WEEK. TEMPS ON THURSDAY WILL SOAR INTO THE UPPER 40S TO LOWER 50S...AND THIS WILL FEEL PLEASANT GIVEN ANTECEDENT TEMPS. OVERALL UPPER LEVEL FLOW WILL FLATTEN AHEAD OF A DEEPENING TROUGH ACROSS THE PLAINS. THIS AFOREMENTIONED DEEPENING TROUGH WILL SWING EAST AND NORTHEAST INTO THE TN/OH VALLEYS...AS IT NEGATIVELY TILTS. AT THE SURFACE...A SURFACE LOW WILL DEEPEN AND BRING A ROUND OF SHOWERS ACROSS MUCH OF EASTERN KY FRIDAY AFTERNOON INTO FRIDAY NIGHT. AFTER THIS THE UPPER LEVEL ENERGY WILL THEN BE FOCUSED ON ANOTHER SURFACE LOW THAT DEVELOPS AND DEEPENS ALONG THE MID ATLANTIC COAST. IN EASTERN KY WE WILL CONTINUE TO SEE WRAP AROUND MOISTURE WITH THIS SYSTEM. MUCH COOLER AIR WILL TRAIL THIS SYSTEM AND EVENTUALLY LEAD TO A RAIN/SNOW MIX IN PRECIP SATURDAY AND ALL SNOW BY SATURDAY NIGHT. THESE CHANCES OF SNOW WILL TAPPER OFF SUNDAY. AFTER THIS THE MODELS REALLY BEGIN TO DIVERGE. THE GFS BRINGS ANOTHER CLIPPER DOWN FOR MONDAY...WHILE THE ECMWF KEEPS REGION DRY. RIGHT NOW WILL LEAN TO THE BLEND WHICH BRING SLIGHT CHANCES FOR SNOW SHOWERS ACROSS MUCH OF THE REGION MONDAY. OVERALL WENT TOWARD MODEL BLEND THROUGH THE PERIOD FOR MOST ELEMENTS. DID KEEP OR MAKE MINOR ADJUSTMENTS GIVEN TRENDS AND USUAL TOPO TEMP ISSUES. GIVEN THE CONSISTENCY FOR THE FRIDAY AND SATURDAY SYSTEM RIGHT NOW WOULD EXPECT POPS THAT PERIOD WILL CONTINUE TO TREND HIGHER...AS WE GET CLOSER TO THE PERIOD IF THESE TRENDS REMAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 710 AM EST TUE JAN 12 2016 A QUICK HITTING CLIPPER SYSTEM MOVES INTO EASTERN KENTUCKY LATER THIS MORNING. FROM THIS...EXPECT REDUCED VISIBILITY AND MVFR CIGS AT AT LEAST SYM...JKL...AND SJS FOR A GOOD PART OF THE AFTERNOON WHILE MAINLY JUST SOME MVFR CIGS WILL BE SEEN FOR A TIME AT LOZ AND SME ALONG WITH SOME FLURRIES. FOR MUCH OF THE PERIOD...THERE WILL BE LIGHT SNOW SHOWERS AROUND THE AREA...ACCORDINGLY...THE TAFS HAVE VCSH OUTSIDE OF THE MAIN SNOW WINDOW. WINDS WILL BE UP AT ALL SITES FROM THE SOUTHWEST THIS MORNING BEFORE SHIFTING TO THE WEST AND NORTHWEST LATER THIS AFTERNOON AND INCREASING TO BETWEEN 15 TO 20 KNOTS WITH GUSTS OF UP TO 30 KNOTS POSSIBLE IN SOME OF THE SNOW SHOWERS/SQUALLS. LATER TONIGHT...THE REMAINING LIGHT SNOW SHOWERS AND FLURRIES END FROM WEST TO EAST WITH CLOUDS BREAKING SHORTLY AFTER THAT WHILE THE WINDS GO LIGHT PREDAWN WEDNESDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044- 050>052-058>060-068-069-079-080. WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR KYZ086>088-104-106>120. && $$ UPDATE...HAL SHORT TERM...GREIF LONG TERM...DJ AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
710 AM EST TUE JAN 12 2016 .UPDATE... ISSUED AT 645 AM EST TUE JAN 12 2016 LIGHT SNOW AND FLURRIES ARE CROSSING MAINLY NORTHERN PARTS OF THE AREA WITH LITTLE IN THE WAY OF ACCUMULATIONS REPORTED. A MORE INTENSE BATCH OF SNOW WILL MOVE IN LATER IN THE MORNING. HAVE TIMED THIS BAND THROUGH IN THE GRIDS. ALSO UPDATED THE HOURLY T AND TD GRIDS PER THE LATEST CONDITIONS AND TRENDS...PARTICULARLY MILDER ON TEMPS DUE TO THE STRENGTHENING SOUTHWEST WINDS AHEAD OF THE FRONT. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 07Z SFC ANALYSIS SHOWS A DEEPENING AREA OF LOW PRESSURE MOVING THROUGH THE CENTRAL GREAT LAKES. THIS IS DRIVING AN ARCTIC COLD FRONT INTO THE NORTHWEST PORTION OF THE OHIO VALLEY EARLY THIS MORNING. CLOSER TO HOME...A DECENT PRESSURE GRADIENT EXISTS OVER KENTUCKY BETWEEN THE LOW TO THE NORTH AND HIGH PRESSURE ALONG THE GULF COAST. THIS IS ALREADY MANIFESTING IN SOME BREEZY SOUTHWEST WINDS THROUGH THE BLUEGRASS HELPING TO KEEP NIGHTTIME TEMPERATURES RELATIVELY MILD FOR MUCH OF THE AREA. WHILE MOST PLACES ARE SEEING LOW AND MID 30S FOR THE JKL CWA...A FEW SHELTERED EASTERN VALLEYS REMAIN IN THE MID 20S. WINDS ARE GUSTING OVER THE WESTERN PARTS OF THE AREA REACHING THE 25 TO 30 MPH RANGE AT TIMES. ALTHOUGH A DRY AIR MASS IS IN PLACE THE SOUTHERLY WINDS WILL TRY TO BRING IN MORE MOISTURE THROUGH THE FIRST PART OF THE MORNING AHEAD OF THE ARCTIC FRONT. MEANWHILE...DEWPOINTS THROUGHOUT THE AREA ARE RUNNING IN THE UPPER SINGLE DIGITS TO MID TEENS NORTHEAST TO THE MIDDLE AND UPPER TEENS SOUTH. A DECK OF MID LEVEL CLOUDS COVER THE BULK OF EASTERN KENTUCKY WITH EVEN A FEW VERY LIGHT SNOW SHOWERS AND FLURRIES PASSING THROUGH. THE MODELS ARE IN EXCELLENT AGREEMENT WITH THE UPPER AIR PATTERN THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE CORE OF A FAIRLY DEEP TROUGH...THAT IS MOVING INTO THE OHIO VALLEY...TO PUNCH THROUGH KENTUCKY BY EARLY AFTERNOON. THIS IS DRIVEN BY A 135 TO 140 KT 300 MB JET ARCING INTO THE REGION THIS MORNING WITH A GOOD AMOUNT A UPPER LEVEL DIVERGENCE PROGGED TO PASS OVER EAST KENTUCKY BETWEEN 09 AND 21Z. IT WILL BE A QUICK HITTING MID LEVEL WAVE...THOUGH...AS BY 00Z IT WILL BE OFF THE MID ATLANTIC COAST ALLOWING HEIGHTS TO RELAX LOCALLY AND RISE INTO THE DAY WEDNESDAY. A COUPLE OF WEAKER WAVES DO FOLLOW IN NORTHWEST FLOW AND LOOK TO PASS ABOVE EAST KENTUCKY FOR WEDNESDAY. GIVEN THE GOOD MODEL MATCH-UP WILL FOLLOW SUIT BUT FAVOR THE SPECIFICS FROM THE HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS... ALONG WITH A HEALTHY DOSE OF CLIMATOLOGY FOR THESE SITUATIONS IN EASTERN KENTUCKY. SENSIBLE WEATHER WILL FEATURE A DYNAMIC AND ACTIVE WEATHER DAY AS AN ARCTIC BOUNDARY PASSES THROUGH THE CWA BY LATE IN THE AFTERNOON. WHILE LIGHT SNOW WILL BE POSSIBLE AHEAD OF THIS BOUNDARY...THE MAIN SHOW WILL BE JUST ALONG AND BEHIND IT AS IT HELPS TO MAXIMIZE THE MID LEVEL LAPSE RATES AND FIND JUST ENOUGH CAPE TO BECOME CONVECTIVE IN NATURE. GIVEN THE BACKGROUND PRESSURE AND HEIGHT GRADIENTS IN THE THE LOWER LEVELS OF THE ATMOSPHERE THE HIGHER WINDS ALOFT SHOULD BE ABLE TO BE TAPPED BY THE CONVECTIVE CELLS LEADING TO GUSTY WINDS AT THE SFC. THIS COMBINED WITH THE SNOW SHOWERS WILL MEAN RAPIDLY CHANGING VISIBILITY IN GUSTY SNOW SQUALLS. FINALLY...GIVEN THE COLD STARTING POINT FOR ROAD SFCS... EXPECT ANY SNOW THAT FALLS TO POTENTIALLY ACCUMULATE ON THE ROADS...WITH LIMITED HELP FROM INSOLATION DURING THE DAYLIGHT HOURS. SO...ALTHOUGH QPF WILL BE RATHER LIMITED WITH THIS FRONT... THE IMPACT FROM THESE LIGHT EVENTS CAN BE AS LARGER OR LARGER THAN BIGGER WINTER STORMS SO WILL CONTINUE TO HIT IT HARD WITH A WSW ADVISORY ACROSS THE BULK OF OUR CWA TODAY...STARTING EARLIER IN THE WEST AND LINGERING LONGER IN THE EAST. SNOW AMOUNTS SHOULD BE MAXIMIZED...WITH A POTENTIAL FOR UP TO 2 INCHES...IN THE NORTHERN PARTS OF THE CWA AND IN THE HIGHEST TERRAIN NEAR THE VIRGINIA BORDER. THE SNOW WILL END FROM WEST TO EAST IN THE EVENING...WITH A DROP OFF IN THE SQUALLINESS AFTER SUNSET. LOOK FOR A HINT OF UPSLOPE COMPONENT INTO THE NIGHT TO KEEP A SMALL THREAT OF SNOW SHOWERS AND FLURRIES GOING IN THE FAR EAST THROUGH EARLY WEDNESDAY MORNING...BUT ANY ADDITIONAL ACCUMULATIONS WILL BE MARGINAL AFTER THIS EVENING. CHILLY HIGH PRESSURE THEN SPREADS INTO THE STATE WITH LOW TEMPERATURES NEARING THE SINGLE DIGITS IN THE NORTHWEST BY DAWN WEDNESDAY. WINDS STILL BRISK WILL YIELD WIND CHILLS DOWN NEAR ZERO IN SPOTS AND MAINLY SINGLE DIGITS ELSEWHERE AT DAWN WEDNESDAY. READING WILL THEN STRUGGLE TO RISE OUT OF THE 20S ON WEDNESDAY DESPITE A RETURN OF SOME SUNSHINE. IN FACT...THE SUNSHINE WILL LIKELY BE LIMITED BY SOME MID AND HIGH LEVEL CLOUDS INBOUND FROM THAT NEXT...WEAKER...WAVE PASSING BY AT MID LEVELS. ACCORDINGLY...HAVE NOT ZEROED OUT POPS FOR LATER WEDNESDAY AS A COUPLE OF FLURRIES CANNOT BE RULED OUT FROM THIS FEATURE WHEN IT BRUSHES BY FROM WEDNESDAY AFTERNOON INTO THE EVENING. USE THE SHORTBLEND AS A STARTING POINT FOR TEMPERATURES AND DEWPOINTS THROUGH THE EVENING WITH THE SUPERBLEND USED THEREAFTER. MADE ONLY MINOR ADJUSTMENTS FOR SOME TERRAIN DISTINCTIONS TONIGHT...AS THE GRIDS LOOKED REASONABLE. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF THE MOS...WHICH IS TYPICAL FOR THIS TYPE OF SITUATION. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 PERIOD WILL BEGIN WITH A MID LEVEL TROUGH MOVING ACROSS THE OHIO VALLEY WEDNESDAY NIGHT...WHILE PRECIP WILL BE POSSIBLE NORTH OF THE REGION ACROSS CENTRAL OH. WE WILL MAINLY SEE CLOUDS ASSOCIATED WITH THIS WAVE WEDNESDAY NIGHT HERE IN EASTERN KY. ON THURSDAY HIGH WILL BE PARKED TO THE SE AND WILL INTRODUCE RETURN FLOW TO THE REGION. THIS WILL ALLOW TEMPS TO MODERATE THROUGH THE END OF THE WEEK. TEMPS ON THURSDAY WILL SOAR INTO THE UPPER 40S TO LOWER 50S...AND THIS WILL FEEL PLEASANT GIVEN ANTECEDENT TEMPS. OVERALL UPPER LEVEL FLOW WILL FLATTEN AHEAD OF A DEEPENING TROUGH ACROSS THE PLAINS. THIS AFOREMENTIONED DEEPENING TROUGH WILL SWING EAST AND NORTHEAST INTO THE TN/OH VALLEYS...AS IT NEGATIVELY TILTS. AT THE SURFACE...A SURFACE LOW WILL DEEPEN AND BRING A ROUND OF SHOWERS ACROSS MUCH OF EASTERN KY FRIDAY AFTERNOON INTO FRIDAY NIGHT. AFTER THIS THE UPPER LEVEL ENERGY WILL THEN BE FOCUSED ON ANOTHER SURFACE LOW THAT DEVELOPS AND DEEPENS ALONG THE MID ATLANTIC COAST. IN EASTERN KY WE WILL CONTINUE TO SEE WRAP AROUND MOISTURE WITH THIS SYSTEM. MUCH COOLER AIR WILL TRAIL THIS SYSTEM AND EVENTUALLY LEAD TO A RAIN/SNOW MIX IN PRECIP SATURDAY AND ALL SNOW BY SATURDAY NIGHT. THESE CHANCES OF SNOW WILL TAPPER OFF SUNDAY. AFTER THIS THE MODELS REALLY BEGIN TO DIVERGE. THE GFS BRINGS ANOTHER CLIPPER DOWN FOR MONDAY...WHILE THE ECMWF KEEPS REGION DRY. RIGHT NOW WILL LEAN TO THE BLEND WHICH BRING SLIGHT CHANCES FOR SNOW SHOWERS ACROSS MUCH OF THE REGION MONDAY. OVERALL WENT TOWARD MODEL BLEND THROUGH THE PERIOD FOR MOST ELEMENTS. DID KEEP OR MAKE MINOR ADJUSTMENTS GIVEN TRENDS AND USUAL TOPO TEMP ISSUES. GIVEN THE CONSISTENCY FOR THE FRIDAY AND SATURDAY SYSTEM RIGHT NOW WOULD EXPECT POPS THAT PERIOD WILL CONTINUE TO TREND HIGHER...AS WE GET CLOSER TO THE PERIOD IF THESE TRENDS REMAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 710 AM EST TUE JAN 12 2016 A QUICK HITTING CLIPPER SYSTEM MOVES INTO EASTERN KENTUCKY LATER THIS MORNING. FROM THIS...EXPECT REDUCED VISIBILITY AND MVFR CIGS AT AT LEAST SYM...JKL...AND SJS FOR A GOOD PART OF THE AFTERNOON WHILE MAINLY JUST SOME MVFR CIGS WILL BE SEEN FOR A TIME AT LOZ AND SME ALONG WITH SOME FLURRIES. FOR MUCH OF THE PERIOD...THERE WILL BE LIGHT SNOW SHOWERS AROUND THE AREA...ACCORDINGLY...THE TAFS HAVE VCSH OUTSIDE OF THE MAIN SNOW WINDOW. WINDS WILL BE UP AT ALL SITES FROM THE SOUTHWEST THIS MORNING BEFORE SHIFTING TO THE WEST AND NORTHWEST LATER THIS AFTERNOON AND INCREASING TO BETWEEN 15 TO 20 KNOTS WITH GUSTS OF UP TO 30 KNOTS POSSIBLE IN SOME OF THE SNOW SHOWERS/SQUALLS. LATER TONIGHT...THE REMAINING LIGHT SNOW SHOWERS AND FLURRIES END FROM WEST TO EAST WITH CLOUDS BREAKING SHORTLY AFTER THAT WHILE THE WINDS GO LIGHT PREDAWN WEDNESDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044- 050>052-058>060-068-069-079-080. WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR KYZ086>088-104-106>120. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...DJ AVIATION...GREIF
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
523 AM CST TUE JAN 12 2016 .SHORT TERM...(Today through Thursday night) Issued at 244 AM CST TUE JAN 12 2016 Mid level energy will swing SE from IA/WI to the Ohio Valley this a.m. with an assoc sfc front. Will continue with the light snow possibility KEVV tri-state area. Only minor accumulations forecast, mainly dusting, to around 1/2" (especially north and east of KEVV) give or take. This activity will quickly depart early this a.m. followed by decreasing clouds. Quiet weather tonight through Thursday as high pressure moves across the area. Temperatures will moderate Wednesday through Thursday once return flow sets up. Still on track for showers to spread northeast across the area after midnight Thursday night. The 00z NAM is by far the fastest and most aggressive. We tempered that solution with the more consistent GFS/ECMWF solutions of the past couple of days. .LONG TERM...(Friday through Monday) Issued at 244 AM CST TUE JAN 12 2016 High confidence in rain event Friday. Low confidence after that period and low confidence in exact temperatures throughout the extended. The rain event for Friday looks to be on track as models locked on to this solution last week and remain steadfast. Also as previous discussion see some elevated instability with negative showalters and K index values around 30. There is also some hints of surface based instability with LI`s going negative with 100+ j/kg2 of CAPE. Nothing impressive but a clap of thunder cant be ruled out. This also is starting to be picked up with other offices. Friday night rain will slowly turn over to flurries after midnight with little impact/accumulation expected. Flurries may persist into Saturday but again confidence is low as is available moisture. After this point the models diverge significantly with ECMWF indicating a mostly dry extended and GFS not so much. Regardless of if it precipitates or not it again has very limited moisture therefore little to no impact expected. Models are coming in with nearly a 10 degree spread in the extended temperatures. The extended init took a middle of the road solution for temps and I opted to follow suit. Either way temperatures will again fall below normal for the extended. && .AVIATION... Issued at 523 AM CST TUE JAN 12 2016 Light snow chance north of a KMVN-KOWB line may yield temporary MVFR vsbys with generally VFR cigs all areas. SW winds will become WNW with gusts 20-30 kts through the morning. The winds will diminish this afternoon with decreasing clouds area wide. Mainly clear tonight with light winds. && .PAH Watches/Warnings/Advisories... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$
Area Forecast Discussion National Weather Service Louisville KY 600 AM EST TUE JAN 12 2016 .SHORT TERM (Now through Wednesday)... Issued at 225 AM EST Tue Jan 12 2016 ...Snow to Impact Travel This Morning Across Southern IN and Central KY... A vigorous weather system dropping out of the Upper Midwest will bring a 3-5 hour period of moderate snow showers to southern Indiana and northern Kentucky this morning. The light but quick accumulations will make for slick travel during the morning commute. The 2 am surface analysis showed a low pressure system over central Michigan while a warm front was passing through Indiana and western Ohio. A strong Arctic front is currently sweeping across Iowa and Wisconsin evident by a strong pressure fall/rise couplet, crashing temperatures, strong winds and a band of light to moderate snow. The Iowa/Wisconsin feature is what will track through southern Indiana and northern Kentucky later this morning. ===Timing=== HRRR and RAP have been the most consistent with its timing over the last several hourly runs, showing just a slight delay compared to our previous forecast. Expect this shield of snow showers to move into our southern/southwest Indiana counties between 7-8 am, then quickly drop into the Louisville metro and north-central Kentucky counties between 8-10am. Finally, it should sweep across the northern Bluegrass between 9-11am. Expect a 3-5 hour period of moderate snow showers at any given location in this zone. It will be showery, so intermittent breaks can be expected. By late afternoon, most areas will transition to flurries or an occasional snow shower but accumulating snow will be done by mid-afternoon. ===Accumulations=== No major changes to total snowfall forecast from previous shifts. Despite the limited moisture (QPF less than 0.1 of an inch), above normal snow ratios and a fair amount of the atmosphere within the DGZ will result in a quick 1 to 2 inches in the advisory area, especially along/north of the Ohio River. A localized 3 inch amount is still possible. ===Winds/Temps=== As the front crosses the region this morning, the strong pressure changes will result in 20 to 30 mph westerly winds. Expect some gusts to reach 35 mph at times from mid morning to early/mid afternoon. At the same time, temperatures will be falling throughout the day, especially north of the KY parkways. By mid afternoon, teens will be common along/north of I-64. Combined with the wind, plan on wind chill values in the teens to single digits. ===Impacts=== The quick hitting but moderate snow showers accumulating 1 to 2 inches will make for slick and hazardous travel conditions today. While the duration of the snow is expected to be only 3-5 hours, the rates while it is snowing will cause quick accumulations on roads and other surfaces, along with reductions in visibility and driving conditions. Road temperatures across the area range from 28 to 34F, so while treatment efforts will help, untreated surfaces and less traveled roads will become snow covered. The timing during the morning commute increases the impacts expected. The wind/falling temperatures will add a bite as well, especially by afternoon as wind chills fall down into the teens/single digits. As a result, no changes are planned for the winter weather advisory across the region. Tonight - Wednesday Expect a rapid clearing of clouds/lingering flurries by late afternoon or early evening (west to east) as cold Canadian high pressure builds overhead. The surface high should be right over central Kentucky by Wednesday morning, setting the stage for a very cold morning. It would be similar to yesterday (Monday) morning when lows ranged from +2 to +12. The fresh snowpack will help as well. For Wednesday, the high transitions to the east but the cold air mass lingering overhead will keep highs in the upper 20s to low 30s north of the KY parkways. Across south-central Kentucky, readings should reach the mid/upper 30s. .LONG TERM (Wednesday Night through Monday)... Issued at 225 AM EST Tue Jan 12 2016 The main forecast challenge in the long term period is a storm system Friday night into the weekend, followed by another round of unseasonably cold air. Wednesday Night - Friday This period will be characterized by high pressure settling over the southeast US with the upper level pattern mainly a dry northwest flow. A quick shortwave trough is expected to pass across the lower Great Lakes Wednesday night, but clouds/precip will stay well to the north. Expect a slow moderation in temperatures as well with highs rebounding into the 40s on Thursday and approaching the 50 degree mark on Friday. Friday Night - Saturday Night 01.12z guidance continued to advertise a storm system lifting out of the Gulf coast region toward the Great Lakes Friday night through Saturday, potentially continuing through Saturday night. The surface low track at this point stays just west of the area, which would favor a warmer (rain) solution for the area for the majority of the period. We`ll have to watch closely to see if falling temperatures behind the frontal passage early Saturday morning will meet up with remaining rain for a changeover to snow. After a warm Friday, expect a much colder Saturday with highs in the 30s. Sunday - Next Week Forecast guidance shows several shortwave troughs sweeping through in northwest flow aloft which look to bring reinforcing shots of colder air along with chances for snow showers. At this time, a model consensus points toward one on Sunday followed by another Monday night. Will keep slight chances of snow showers in the forecast with highs in the 30s and lows in the teens to low 20s. && .AVIATION (12Z TAF Update)... Updated at 600 AM EST Tue Jan 12 2016 Low pressure crossing Michigan will swing a cold front through the region this morning. This front will bring a quick (2-4 hour) shot of snow showers and MVFR cigs/vsbys to SDF and LEX (little more than flurries and a shower or two to BWG). These snow showers will be accompanied by very gusty winds coming in from the WSW. Behind the snow showers and cold front winds will remain strong for a few more hours into early afternoon, coming in from the west and possibly gusting to 30 or 35 knots, especially at SDF and LEX. Ceilings this afternoon are a bit tougher to figure out...for now will hold on to an MVFR stratocu ceiling for much of the afternoon, though that may be on the pessimistic side. High pressure advancing from STL to BNA tonight will clear skies and bring wind speeds down. && .LMK Watches/Warnings/Advisories... KY...Winter Weather Advisory until 4 PM EST /3 PM CST/ this afternoon for KYZ023>025-028>034-038-045-053. Winter Weather Advisory until 7 PM EST this evening for KYZ035>037-039>043-046>049-054>057-065>067. IN...Winter Weather Advisory until 4 PM EST /3 PM CST/ this afternoon for INZ076>079-083-084-089>092. && $$ Short Term........ZT Long Term.........ZT Aviation..........13
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 AM EST TUE JAN 12 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EST TUE JAN 12 2016 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UPR TROF DOMINATING THE E HALF OF NAMERICA DOWNSTREAM OF HI AMPLITUDE RDG OVER THE W. POTENT SHRTWV DIGGING SEWD THRU THE TROF IS DIGGING SEWD THRU THE UPR MIDWEST...BRINGING 12HR H5 HGT FALLS TO ARND 100M AT INL AND MPX. ALTHOUGH THE SHRTWV ITSELF IS PASSING FAIRLY FAR TO THE S...DEEP LYR QVECTOR CNVGC AS WELL DEEP MOISTENING SHOWN ON THE 00Z INL RAOB ARE IMPACTING UPR MI...BRINGING SOME -SN TO MUCH OF THE CWA DESPITE LACK OF MSTR INFLOW/VERY DRY LLVLS SHOWN ON THE 00Z GRB RAOB. LLVL WINDS/SFC OBS ALSO INDICATE A SHARP LK INDUCED TROF IS IN THE PROCESS OF MOVING ONSHORE EARLY THIS MRNG AS THE LLVL WINDS VEER TO THE NNW FOLLOWING SHRTWV PASSAGE TO THE S. THE WSHFT/TROF PASSAGE AT CMX AND IWD WAS ACCOMPANIED BY SOME HEAVY SN SHOWERS. MQT RADAR IS ALSO SHOWING SOME MORE SGNFT RETURNS OVER SCENTRAL LK SUP EARLY THIS MRNG. TO THE N...THE 00Z H85 TEMP AT PICKLE LAKE ONTARIO WAS -30C...BUT THE NEAR SFC LYR THERE IS RATHER DRY. SKIES ARE MOCLR OVER MOST OF NRN MN/ADJOINING NW ONTARIO...WITH SFC DEWPTS NEAR -20F. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMNTS ASSOCIATED WITH THE SHRTWV/LK INDUCED TROF AND THEN LES TRENDS FOLLOWING THE PASSAGE OF THE SHRTWV/INFLUX OF COLDER AND DRIER AIR. TODAY...AS THE DIGGING SHRTWV EXITS TO THE SE...LLVL WINDS ARE FCST TO SHIFT TO THE NNW EARLY THIS MRNG...DRIVING THE LK INDUCED TROF STILL OVERL K SUP EARLY THIS MRNG. THE TROF IS EXPECTED TO BE THRU THE WRN ZNS BY FCST ISSUANCE...MARQUETTE ARND 12Z AND THEN NEWBERRY ARND 15Z. HIER RES RAP MODEL FCST SNDGS FOR SEVERAL LOCATIONS NEAR LK SUP SHOW A VERY SHARP AXIS OF ENHANCED LLVL UVV CENTERED WITHIN THE DGZ IN THE 1-4K FT AGL LYR...SO STILL EXPECT A BURST OF HEAVER SN WHEN THIS TROF COMES ONSHORE. HIER RES MODELS HINT AT 0.10-0.20 INCH OF WATER EQUIVALENT PCPN IN THE 6HR PERIOD CENTERED ARND THE TROF PASSAGE...WHICH WOULD SUPPORT AS MUCH AS 3-4 INCHES OF SN GIVEN THE FAVORABLE SN/WATER RATIOS. FARTHER INLAND...THE TROF/LLVL CNVGC ARE FCST TO WASH OUT...SO THE HEAVIER SN SHOWERS SHOULD OCCUR ONLY NEAR THE LK SUP SHORE. SHARP WSHFT OFF THE LK WITH LLVL MIXED LYR WINDS UP TO 30 KTS WL ALSO RESULT IN SOME BLSN/REDUCED VSBYS. GOING ADVYS IN THE LK SHORE COUNTIES SEEM APPROPRIATE. FOLLOWING THE TROF PASSAGE...DVLPG LARGER SCALE QVECTOR DVGC/ SUBSIDENCE ABOVE LLVL COLD SURGE THAT WL DROP H85 TEMPS TO AS LO AS -24C WL RESULT IN THE MORE TYPICAL WIND PARALLEL PURE LES BANDS. ASSOCIATED MID LVL DRYING/SUBSIDENCE INVRN BASE LOWERING TO 4-5K FT AGL AND IMPACT OF LLVL DRY AIR NOTED FARTHER UPSTREAM WL TEND TO LIMIT THE PURE LES ACCUMS AS WILL SHIFTING BANDS RELATED TO EXPECTED STEADILY BACKING WINDS TO THE WNW BY LATER IN THE DAY. WITH THE INFLUX OF VERY COLD AIR...MAX TEMPS WL RUN WELL BLO NORMAL AND NOT RISE ABOVE 5 TO 10F OVER THE W. TNGT...MODELS INDICATE ANOTHER SHRTWV SLIDING SEWD IN THE NW FLOW ALOFT WL MOVE INTO THE AREA TNGT...WITH AREA OF DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF THIS FEATURE RESULTING IN DEEPENING MSTR/SOME RISE IN INVRN BASE. THE LLVL WINDS ARE FCST TO BACK TO ABOUT 270-280 DEGREES BY 12Z WED...SO NRN ONTONAGON COUNTY/HOUGHTON COUNTIES AND AREAS NEAR LK SUP FM GRAND MARAIS TO WHITEFISH POINT LOOK TO BE THE FOCUS FOR THE HEAVIER SN SHOWERS. ENHANCED LAND BREEZE CNVGC RELATED TO THE VERY COLD AIR THAT WL DROP MIN TEMPS AT LEAST CLOSE TO -10F IN THE UNMODIFIED AIR NEAR THE WI BORDER WL SHARPER THE LLVL CNVGC AND THE SRN EDGE OF THE HEAVIER SN SHOWERS. SINCE NAM FCST SDNGS FOR CMX SHOW INCRSG UVV WITHIN THE DGZ TOWARD 12Z WED...NOT OUT OF THE QUESTION SOME ADVY LES WL OCCUR IN THESE FAVORED AREAS. ALTHOUGH WINDS ARE NOT LIKELY TO STAY UP NEAR THE WIND CHILL ADVY THRESHOLD OF 10 MPH OVER THE INTERIOR COLD SPOTS NEAR THE BORDER...APRNT TEMPS ARE LIKELY TO FALL AS LO AS -20 TO -25F. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 309 AM EST TUE JAN 12 2016 THE UPPER GREAT LAKES WILL STILL BE UNDER THE INFLUENCE OF THE ARCTIC AIR MASS AT THE START OF THE LONG TERM FORECAST...WITH LAKE EFFECT SNOW ONGOING IN THE WESTERLY WIND SNOW-BELTS. STILL EXPECT LIGHT TO MODERATE LAKE EFFECT TO BE OCCURRING OVER THE WEST AND KEWEENAW PENINSULA WEDNESDAY MORNING WITH INVERSION HEIGHTS AROUND 6KFT AND SOME INCREASED LOW LEVEL CONVERGENCES DUE TO THE HIGH PRESSURE RIDGE SLIDING TO THE SOUTH OF THE AREA AIDING LOW LEVEL BACKING FLOW OVER THE FAR WESTERN U.P.. SINCE THE LOWERING INVERSION WILL START TO KEEP MORE OF THE CLOUD LAYER WITHIN THE DGZ...SHOULD START TO SEE RATIOS COME UP AND WOULD THINK THERE WILL BE AN AREA OF ADVISORY SNOWFALL WITHIN THE DOMINATE BAND SETUP OVER NORTHERN ONTONAGON AND NORTHERN HOUGHTON COUNTIES AND SOMEWHERE BETWEEN SOUTH RANGE AND GREENLAND. THIS BAND SHOULD LIFT NORTH THROUGH THE AFTERNOON AND BE CENTERED AROUND OR TO THE NORTH OF HOUGHTON. AS TEMPERATURES ALOFT MODERATE THROUGH THE AFTERNOON/NIGHT (850MB TEMPS RISE TO -17C)...EXPECT ALL OF THE CLOUD TO FALL WITHIN THE DGZ WHICH WILL LEAD TO VERY FLUFFY SNOW AND HIGH RATIOS THROUGH WEDNESDAY NIGHT. WILL TREND POPS/RATIOS/SNOWFALL UP WITH THE FAVORABLE CONDITIONS FOR THE KEWEENAW WEDNESDAY AFTERNOON AND NIGHT BEFORE WARMING ALOFT (ASSOCIATED WITH THE APPROACHING SURFACE TROUGH AHEAD OF THE PLAINS LOW) QUICKLY BRINGS AN END TO THE LES ON THURSDAY MORNING. OVER THE EAST...THE WEST TO EVENTUALLY WEST-SOUTHWEST WINDS WILL KEEP THE BANDS LARGELY OFFSHORE BUT DID INCLUDE SOME HIGHER POPS IN CASE THE BAND AFFECTS AREAS TO THE EAST OF GRAND MARAIS. ONE FINAL ITEM OF NOTE BEFORE GETTING INTO THE LOW DEVELOPING INTO THE PLAINS...SHOULD SEE A WEAK SHORTWAVE MOVING THROUGH WISCONSIN WEDNESDAY NIGHT AND COULD SEE A FEW LIGHT SNOW SHOWERS ALONG THE WISCONSIN BORDER THROUGH THE NIGHT. THE SECOND HALF OF THE LONG TERM FORECAST WILL BE FOCUSED ON THE SURFACE LOW DEVELOPING IN THE NORTHERN/CENTRAL PLAINS AS A SHORTWAVE CROSSES THE ROCKIES. AS IT DEVELOPS AND SLIDES SOUTHEAST INTO THE MID MISSISSIPPI VALLEY THURSDAY INTO THURSDAY NIGHT...IT WILL STRETCH A TROUGH EAST-NORTHERN INTO THE GREAT LAKES REGION. AT THIS POINT...MODELS ARE FAIRLY CONSISTENT ON THE SURFACE TROUGH BEING JUST TO THE SOUTH OF THE AREA AND STRETCHING EAST ACROSS SOUTHERN WISCONSIN AND LOWER MICHIGAN. BUT WITH WEAK MID LEVEL WARM AIR ADVECTION TO THE NORTH OF THE TROUGH...SHOULD SEE SOME LIGHT SNOW SHOWERS MOVING ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT. RIGHT NOW...LOOKING LIKE 1-3 INCHES OF SNOW FROM THURSDAY NIGHT INTO FRIDAY...WITH THE HIGHEST AMOUNTS WHERE THE LAKE ENHANCEMENT OCCURS. THAT POTENTIAL INCREASES THURSDAY NIGHT INTO FRIDAY AS THE TROUGH SLIDES EAST AND THE LOW BEGINS TO STRENGTHEN IN NORTHERN MISSOURI AS THE SHORTWAVE MERGES WITH A SOUTHERN STREAM WAVE. EXPECT THE LES TO OCCUR IN THE NORTHEASTERLY WIND AREAS...WITH THE BEST SNOW POTENTIAL OCCURRING IN THE UPSLOPE AREAS OF MARQUETTE COUNTY (ESPECIALLY THE HURON MOUNTAINS). WILL TREND POPS UP FOR THAT AREA...BUT WITH MUCH OF THE CLOUD HOVERING AROUND OR JUST BELOW -10C...DON/T EXPECT THE LAKE EFFECT/ENHANCEMENT TO GET TO OUT OF HAND. MODELS STILL STRUGGLING WITH THE EXTENDED PERIOD...ESPECIALLY THE THE EVOLUTION OF THE LOW COMING OUT OF THE CENTRAL MISSISSIPPI VALLEY. THE 00Z ECMWF HAS SHIFTED AWAY FROM THE PREVIOUS RUNS AND TOWARDS WHAT THE 11/00Z RUN OF THE GFS WAS SHOWING (TRACKING THE LOW FARTHER NORTHWEST THROUGH NORTHERN LOWER MICHIGAN DUE TO A MORE ELONGATED UPPER TROUGH). MEANWHILE...THE 00Z GEM/GFS TRACK THE LOW THROUGH SOUTHEASTERN LOWER MICHIGAN BUT THAT IS ENOUGH TO HAVE SOME LIGHT SNOWFALL OVER THE SOUTHEAST HALF OF THE CWA. AT THIS POINT...THINK CHANCE POPS IS THE WAY TO GO WITH LIKELIES OVER THE NORTH CENTRAL WITH LAKE ENHANCEMENT. ANOTHER SURGE OF ARCTIC AIR DROPS INTO THE AREA FOR THE SECOND HALF OF THE WEEKEND AND EARLY NEXT WEEK BUT IT LOOKS LIKE IT WON/T BE AS COLD OR LAST AS LONG AS THIS PAST ARCTIC AIR PERIOD. SHOULD STILL SEE LAKE EFFECT SNOW THOUGH AND WILL TREND POPS UP (TO LIKELY VALUES AT LEAST) FOR THE NORTH-NORTHWESTERLY WIND AREAS ON SUNDAY AND MONDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 643 AM EST TUE JAN 12 2016 A BAND OF MDT/HEAVY SHSN AND GUSTY WINDS/BLSN WL IMPACT SAW FOR THE FIRST HR OR SO OF THE FCST PERIOD AND BRING LIFR CONDITIONS. ALTHOUGH IFR VSBYS WL PREVAIL THIS MRNG AT SAW AND CMX/IWD...INCRSG SUBSIDENCE/SOME LLVL DRYING/DIMINISHING WINDS AND BLSN THIS AFTN IN THE WAKE OF A DISTURBANCE PASSING WELL TO THE S OF UPR MI WL ALLOW FOR IMPROVEMENT INTO THE MVFR RANGE THIS AFTN. THE IMPROVEMENT WL BE MOST NOTICEABLE AT SAW...WHERE DOWNSLOPE NATURE OF THE BACKING WIND TOWARD THE NW WL BRING VFR CONDITIONS. AS THE LLVL FLOW CONTINUES TO BACK SLOWLY TOWARD THE WSW TNGT...SAW WL STAY VFR AND IWD WL SEE IMPROVEMENT TO VFR WITH DIMINISHED LK MODERATION OF INCOMING VERY DRY ARCTIC AIR. BUT AT CMX...VSBYS ARE LIKELY TO DETERIORATE TO IFR WITH MORE FOCUSED LLVL CNVGC/FAVORABLE UPSLOPE WIND COMPONENT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 AM EST TUE JAN 12 2016 STRONG NNW WINDS TODAY WILL REACH 30 KTS UNDER A TIGHT PRES GRADIENT BETWEEN LO PRES TRACKING THRU THE LOWER GREAT LAKES AND CANADIAN HI PRES BUILDING INTO THE NORTHERN PLAINS. ALTHOUGH GALES ARE NOT EXPECTED...THERE COULD BE A FEW GALE GUSTS...AND THE INCOMING AIRMASS WILL BE SUFFICIENTLY COLD TO GENERATE HEAVY FREEZING SPRAY. THE WINDS WILL BACK MORE TO THE NW THIS AFTERNOON AND DIMINISH AS THE HI PRES RIDGE GETS CLOSER...SO THE HEAVY FREEZING SPRAY WILL END. RELATIVELY LIGHT WINDS UNDER 25 KTS WILL THEN DOMINATE LATE TONIGHT THRU THU NIGHT. BUT AS ANOTHER LO PRES MOVES NE THRU THE CENTRAL GREAT LAKES ON FRI/SAT...NE WINDS WILL INCREASE UP TO 30 KTS UNDER THE TIGHTER PRES GRADIENT BETWEEN THE LO AND COLD HI PRES IN WCENTRAL CANADA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ005. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LSZ248>251-265-266. HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ241>244-263-264. HEAVY FREEZING SPRAY WARNING UNTIL 10 AM EST /9 AM CST/ THIS MORNING FOR LSZ240. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
551 AM CST TUE JAN 12 2016 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST TUE JAN 12 2016 NORTHWEST FLOW HAS BROUGHT ARCTIC AIR TO THE NORTHLAND. MOSTLY CLEAR SKIES HAVE HELPED TEMPERATURES DROP TO THE SINGLE DIGITS AND TEENS BELOW ZERO EARLY THIS MORNING. THE EXCEPTION IS FOR AREAS OF NW WISCONSIN DOWNWIND OF THE NW FLOW OVER LAKE SUPERIOR...WHERE THE LAKE EFFECT CLOUD COVER IS HELPING TEMPERATURES STAY SEVERAL DEGREES WARMER. A DEEP LOW OVER THE CENTRAL GREAT LAKES WILL SHIFT EAST INTO SOUTHERN ONTARIO TODAY. A SUBTLE UPPER LEVEL TROUGH OVER NORTHERN ONTARIO WILL PASS THROUGH THE NORTHLAND THIS MORNING. THE NW FLOW OVER THE LAKE WILL CONTINUE TO PRODUCE LAKE EFFECT SNOW SHOWERS ACROSS DOWNWIND AREAS OF NW WISCONSIN THROUGH AT LEAST THIS MORNING...AND POSSIBLY WELL INTO THIS AFTERNOON BEFORE ENOUGH DRIER AIR MOVES INTO THE REGION TO TAPER OFF ANY SIGNIFICANT SNOW SHOWERS. THE GREATEST ADDITIONAL SNOWFALL WILL BE FOR AREAS OF NORTHERN IRON COUNTY NEAR THE MICHIGAN BORDER NEAR IRONWOOD...WHERE AN ADDITIONAL 2 TO 4 INCHES WILL FALL THROUGH TODAY. NORTHERN BAYFIELD PENINSULA COULD GET AN ADDITIONAL 1 TO 2 INCHES. LEANED ON THE HIGHER SIDE OF PCPN GUIDANCE...INCLUDING THE WRF NMM AND ARW...AND THE SREF. THE NW WINDS OF 5 TO 15 MPH AND VERY COLD TEMPERATURES WILL CONTINUE TO RESULT IN WIND CHILL VALUES OF 20 TO 35 BELOW ZERO EARLY THIS MORNING. CONDITIONS WILL GRADUALLY IMPROVE AFTER SUNRISE...WITH AFTERNOON VALUES OF ABOUT 10 TO 20 BELOW ZERO. SOME MODELS ARE EXAGGERATING THE CLOUD COVER THIS MORNING...NOTABLY THE GFS AND ECMWF. THE SATELLITE AND OBSERVATIONS INDICATE VERY LITTLE...IF ANY...CLOUD COVER...SAVE FOR AREAS DOWNWIND OF LAKE SUPERIOR. THE HRRR SEEMS TO BE PERFORMING THE BEST...FOLLOWED BY THE NAM12/RAP13/CANADIANREGIONAL. LEANED ON THOSE MODELS FOR CLOUD TRENDS THROUGH THE REST OF THE DAY. THERE WILL LIKELY BE SOME AFTERNOON CUMULUS...ESPECIALLY OVER NORTHERN MINNESOTA. LEANED ON THE WARMER SIDE OF GUIDANCE BECAUSE THE COLDER GUIDANCE...SUCH AS THE GFS...MAY BE COLDER BECAUSE OF THE EXAGGERATED CLOUD COVER. HIGHS SHOULD REACH A FEW DEGREES ABOVE ZERO ACROSS THE SOUTH...AND APPROACH ZERO ACROSS THE NORTH AND WEST. A SURFACE RIDGE OF HIGH PRESSURE WILL BE JUST TO THE WEST AND SOUTH OF THE NORTHLAND TONIGHT. THE WIND SPEEDS WILL BE LIGHTER TONIGHT. THE COMBINATION OF CLEAR SKIES AND LIGHT WINDS THIS EVENING WILL ALLOW TEMPERATURES TO DROP QUICKLY THIS EVENING...DESPITE INCREASING HIGH LEVEL CLOUD COVER MOVING IN FROM THE WEST LATER TONIGHT. LEANED ON THE COLDER SIDE OF GUIDANCE...SUCH AS THE CANADIAN REGIONAL...AND NAM AND GFS MOS. OVERNIGHT LOWS WILL LIKELY BE WELL INTO THE TEENS BELOW ZERO FOR MOST OF THE NORTHLAND...BUT A BIT WARMER NEAR LAKE SUPERIOR. WIDESPREAD WIND CHILL VALUES OF 20 TO 30 BELOW ZERO ARE LIKELY...AND THE DAY SHIFT WILL ADDRESS THE NEED FOR AN ADVISORY ONCE THE ADVISORY FOR THIS MORNING COMES TO AN END. THE INCREASING CLOUD COVER LATE TONIGHT WILL BE ASSOCIATED WITH AN APPROACHING SHORTWAVE AND SUBTLE WARM FRONT ON WEDNESDAY FROM THE WEST. MOST OF THE MODELS ARE INDICATING THIS WAVE WILL BRING VERY MINIMAL AMOUNTS OF PCPN TO THE SW AND SOUTHERN FORECAST AREA LATE WEDNESDAY MORNING AND THROUGH THE AFTERNOON. THE HIGH SNOW TO LIQUID RATIOS OF THE SNOWFALL WILL MAKE IT EASY FOR THIS SHORTWAVE TO PRODUCE A TENTH OR TWO OF AN INCH...DESPITE THE MINIMAL PCPN. NOT ONLY WILL WARMER AIR MOVE INTO THE REGION WEDNESDAY...BUT THE CLOUD COVER WILL HELP INSULATE THE NORTHLAND. TEMPERATURES SHOULD FINALLY REACH THE POSITIVE SINGLE DIGITS AND TEENS AFTER THE RECENT DAYS OF MUCH COLDER THAN NORMAL TEMPERATURES. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 345 AM CST TUE JAN 12 2016 WEDNESDAY NIGHT THROUGH THURSDAY EVENING A NEW SHORTWAVE IS EXPECTED TO SWEEP ACROSS THE AREA...INTERACTING WITH A STRONG BAROCLINIC ZONE WHICH EXTENDS FROM SOUTHERN SASKATCHEWAN SOUTHEAST ACROSS MINNESOTA TO LOWER MICHIGAN. THIS SHOULD BRING A PERIOD OF SNOW ACROSS THE FORECAST AREA MAINLY ON THURSDAY...MAINLY ALONG AND SOUTH OF THE HIGHWAY 2 CORRIDOR. MODELS ARE STILL STRUGGLING WITH THE TIMING AND TRACK OF THIS WAVE...AND WE MAY SEE SOME ADJUSTMENTS IN THE NEXT FEW FORECAST CYCLES BEFORE CONFIDENCE INCREASES. TEMPERATURES TO BE NEAR TO BELOW NORMAL THROUGH THIS PERIOD WITH THE CLOUD COVER KEEPING THINGS MODERATED DESPITE THE STRONG NORTHWEST FLOW. THE NEXT POTENTIAL FOR A STRONGER STORM SHOULD AFFECT THE MIDWEST FRIDAY THROUGH SATURDAY OR SUNDAY. MODELS ARE STILL SHOWING LARGE DIFFERENCES BETWEEN MODELS AND HAVE VERY LOW CONFIDENCE IN THIS PORTION OF THE FORECAST. THE DIFFERENCES ARE MAINLY IN THE STRENGTH AND POSITION OF THE UPPER TROUGH AXIS THAT MOVES THROUGH FRIDAY/FRIDAY NIGHT...AND THE ASSOCIATED SURFACE FEATURES WHICH RANGE FROM HAVING THE STRONG SURFACE LOW OVER MISSOURI TO LAKE MICHIGAN FRIDAY AT 18Z. VARIABILITY REMAINS HIGH IN THE ENSEMBLES AS WELL...AND WOULD EXPECT THIS TO CONTINUE UNTIL THE MIDDLE OF THE WEEK WHEN THE UPPER LEVEL SHORTWAVE FINALLY COMES ONTO THE WEST COAST TO BE SAMPLED BY THE UPPER AIR NETWORK. HAVE KEPT THE LOW CHANCE POPS GOING THROUGH THE PERIOD WITH LAKE EFFECT SNOWS INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE NEAR NORMAL TO START OUT...GETTING COLDER AGAIN LATER IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 542 AM CST TUE JAN 12 2016 MAIN CONCERN THIS MORNING IS FOR STRATUS. LAKE EFFECT STRATUS HAS FORMED DOWNSTREAM OF LAKE SUPERIOR AND IS AFFECTING KHYR THIS MORNING WITH MVFR CEILINGS. THIS STRATUS IS EXPECTED TO CONTINUE THROUGH APPROXIMATELY 18Z...THOUGH THE WINDS SHOULD BE TURNING MORE WESTERLY THROUGH THAT TIME AND IT MAY CLEAR SOONER. THERE IS ALSO AN AREA OF STRATUS OVER SOUTHERN MANITOBA THIS MORNING THAT IS OOZING TOWARDS THE TERMINALS WITH MVFR CEILINGS AND SOME FLURRIES. HAVE CONFIDENCE THAT THIS STRATUS WILL GET INTO KINL FOR AT LEAST A FEW HOURS BEGINNING AROUND 16Z...BUT LOW LEVEL MIXING SHOULD HELP BRING THESE CEILINGS UP AND HAVE BROUGHT BACK THE VFR CEILINGS AROUND 20Z...BUT DO NOT HAVE MUCH CONFIDENCE IN THIS. HAVE BROUGHT THIS STRATUS INTO KHIB AND KDLH AS WELL BUT AS SCATTERED CLOUDS AND WILL NEED SOME AMENDMENTS ONCE TRENDS BECOME CLEAR. KBRD AND KHYR EVEN LESS CERTAIN AND HAVE KEPT VFR FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... DLH 0 -11 10 5 / 0 0 20 20 INL -2 -17 6 -4 / 0 0 10 10 BRD 2 -15 15 9 / 0 0 20 20 HYR 3 -15 10 7 / 0 0 30 20 ASX 5 -10 11 7 / 30 0 20 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR WIZ001>003-006>009. LAKE EFFECT SNOW ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR WIZ004. MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ010>012-018>021- 025-026-033>038. LS...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR LSZ121- 146>148. SMALL CRAFT ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR LSZ140-141. && $$ SHORT TERM...GROCHOCINSKI LONG TERM...LE AVIATION...LE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
552 AM CST TUE JAN 12 2016 .SYNOPSIS... ISSUED AT 333 AM CST TUE JAN 12 2016 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A BROAD TROUGH OF LOW PRESSURE CENTERED ACROSS THE EASTERN HALF OF THE CONUS. LOW PRESSURE WAS LOCATED ACROSS HUDSON BAY...WITH A SECONDARY LOW OVER QUEBEC. FURTHER WEST...A RIDGE EXTENDED FROM THE DESERT SW...NWD INTO IDAHO...WESTERN MT...AND INTO BRITISH COLUMBIA AND THE YUKON. AT THE SURFACE...AN ARCTIC COLD FRONT EXTENDED ROUGHLY FROM WEST OF VALENTINE...TO JUST NORTHEAST OF BROKEN BOW. INVOF THE FRONT...LIGHT SNOW FELL EARLIER THIS EVENING AND FLURRIES CONTINUE ROUGHLY ALONG A LINE FROM VALENTINE TO NORTH OF BROKEN BOW. RADAR RETURNS OVER THE PAST COUPLE OF HRS HAVE SHOWN A DECREASE IN COVERAGE...AS WELL AS INTENSITY OF SNOWFALL. THIS IS SUPPORTED BY SFC OBS AT KVTN...WHICH HAD VISBYS OF AROUND 5SM AT MIDNIGHT...AND 7SM CURRENTLY. EVEN WITH THE ARCTIC FRONT DRAPED ACROSS THE NORTHEASTERN CWA...TEMPS WERE RELATIVELY MILD TONIGHT THANKS TO THE ABUNDANT CLOUD COVER ALONG THE FRONT. SOUTHWEST OF THE FRONT...UNDER CLEAR SKIES...READINGS WERE MILD AS WELL. TEMPERATURES AS OF 3 AM CST RANGED FROM THE TEENS OVER NORTH CENTRAL AND NORTHEASTERN PORTIONS OF THE FORECAST AREA...TO THE LOWER TO MID 20S OVER SOUTHWESTERN PORTIONS OF THE FORECAST AREA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CST TUE JAN 12 2016 TODAY AND TONIGHT...TEMPERATURES WILL BE THE MAIN FORECAST CHALLENGE OVER THE NEXT 24 HOURS. FOR THIS MORNING...BASED ON THE HRRR AND LATEST NAM12 SOLNS...MID LEVEL LIFT WILL COME TO AN END ACROSS THE CENTRAL CWA AROUND 12Z. CLOUDS WILL REMAIN...HOWEVER ANY APPRECIABLE THREAT FOR LIGHT SNOW/FLURRIES IS EXPECTED TO END BEFORE 12Z THIS MORNING. WILL LEAVE OUT MENTION OF THIS IN THE FCST...HOWEVER...WILL CONTINUE TO MONITOR THE SITUATION TOWARD DAY BREAK...AND MAY NEED TO HANDLE THIS WITH A NOW CAST OR TWO IF FLURRIES DO DECIDE TO PERSIST AFTER 12Z. FOR THE REMAINDER OF TODAY...THE FRONTAL BOUNDARY WILL LIFT NORTHEAST AS A WARM FRONT...BECOMING ORIENTED ACROSS THE FAR NORTHEASTERN CWA BY 21Z THIS AFTERNOON. HIGHS WILL VARY WIDELY TDY WITH THE FRONT ANCHORED OVER NERN PORTIONS OF THE CWA. HIGHS WILL RANGE FROM AROUND 20 IN THE FAR NORTHEASTERN CWA...TO THE LOWER 40S IN THE FAR SOUTHWEST. WITH RESPECT TO HIGHS TDY...FOLLOWED THE WARMER MAV GUIDANCE...AS IT HAS HAD A MUCH BETTER TRACK RECORD OF VERIFYING OVER THE PAST COUPLE OF DAYS. FOR TONIGHT...THE WARM FRONT WILL LIFT FURTHER NORTHEAST OF THE AREA. COMPARED TO THE LOWS ATTM IN THE 20S...CLEARING SKIES AND LIGHT WESTERLY WINDS...WILL LEAD TO LOWS TONIGHT IN THE TEENS...WHICH IS STILL 5 TO 10 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 333 AM CST TUE JAN 12 2016 MID RANGE...WEDNESDAY AND THURSDAY...500HPA RIDGE AXIS TO BEGIN THE PERIOD AND BREAKS DOWN BY THE END. MODELS SHOW STRONG WAA AT 850HPA ACROSS THE FORECAST AREA WEDNESDAY WITH 5 TO 7C AT 00Z THU...WHICH SHOULD BE ENHANCED BY DOWNSLOPING. ADJUSTED MAX TEMPS UP A DEGREE OR TWO...WHICH IS STILL UNDERCUTTING THE MAV AND ECM BY A FEW DEGREES. GIVEN MOSTLY CLEAR CONDITIONS AND WESTERLY 20 TO 30 KTS AT 850HPA...CURRENT FORECAST HIGHS ARE PROBABLY TOO COOL. COLD FRONT DROPS SOUTH ACROSS THE AREA THURSDAY AFTERNOON AND EVENING...BUT ENOUGH CLEARING AND MIXING EARLY IN THE DAY WILL ALLOW HIGHS IN THE 40S EAST OF THE PANHANDLE. BETTER MOISTURE PROFILES ARE THU NIGHT INTO FRIDAY...SO INCLUDED -SN AFTER 00Z UNTIL 12Z. SOME SATURATION MAY OCCUR EARLIER ACROSS NORTHWEST NEBRASKA...AND DEPENDING ON TEMPS...PRECIP MAY FALL AS RAIN. FRONTOGENESIS APPEARS STRONGEST ACROSS THE SANDHILLS...BUT THE WINDOW FOR SATURATION AND LIFT WITHIN THE DGZ IS RATHER SHORT...LIMITING QPF. LONG RANGE...FRIDAY THROUGH TUESDAY...IS CHARACTERIZED BY A SERIES OF WAVES AND COOLER TEMPERATURES. THE NEXT ROUND COMES IN LATE FRIDAY INTO EARLY SATURDAY. LOW LEVEL MOISTURE IS SUFFICIENT AS SIGNALED BY EXPANSIVE CLOUD COVER...BUT AGAIN THE WINDOW FOR LIFT AND FRONTOGENETICAL FORCING IS SMALL. THE MERDIONAL 250HPA JET ALSO PASSES THROUGH FAIRLY QUICKLY...NOT CONTRIBUTING MUCH UPPER LEVEL DIFFLUENCE DESPITE A 120KT JET STREAK. THE BEST CHANCE OF -SN IS GENERALLY WEST OF HIGHWAY 83 AND NOT EXPECTING MUCH PRECIPITATION. SATURDAY NIGHT THROUGH MONDAY...THE GFS AND ECM DIVERGE A BIT. THE ECM BRINGS A DISTURBANCE THROUGH EARLY SUNDAY WHILE THE GFS IS 24 HOURS LATER...THUS DELAYING THE STRONG CAA. 850HPA TEMPS ARE SIMILAR IN MAGNITUDE...AROUND -20C AT THE COOLEST POINT. DUE TO UNCERTAINTY IN THE TIMING...WENT MIDDLE OF THE ROAD FOR TEMPS AND HAVE SCHC -SN EARLY TO MID MONDAY ACROSS THE WEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 551 AM CST TUE JAN 12 2016 A BAND OF MVFR CIGS...EXTENDING FROM NEAR KIEN...TO JUST EAST OF KLBF...WILL SLOWLY TRACK EAST TODAY. FOR THE KLBF TERMINAL...EXPECT SCATTERED CLOUDS OF 2000 FT AGL IN THE VICINITY OF THE KLBF TERMINAL THROUGH LATE MORNING...WITH CLEARING SKIES THEREAFTER. FOR THE KVTN TERMINAL...EXPECT OVERCAST CIGS AROUND 2500 FT AGL THIS MORNING...BECOMING SCATTERED THIS AFTERNOON. BY LATE AFTERNOON...CLEARING SKIES ARE EXPECTED AT THE KVTN TERMINAL. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...SNIVELY AVIATION...BUTTLER
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1017 AM EST TUE JAN 12 2016 .SYNOPSIS... A STRONG ALBERTA CLIPPER WILL PASS JUST NORTH OF THE REGION TUESDAY DRAGGING A TRAILING ARCTIC FRONT THROUGH US THIS AFTERNOON. COLD HIGH PRESSURE FOLLOWS THE FRONT FOR THE MIDDLE OF THE WEEK. LOW PRESSURE MOVES FROM THE GULF COAST FRIDAY MORNING TO THE MID ATLANTIC SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM EST TUESDAY... INITIAL BATCH OF LIGHT SNOW/SNOW SHOWERS WELL AHEAD OF THE ACTUAL COLD FRONT BACK IN THE OHIO VALLEY HAS CONTINUED TO SLOWLY FADE UPON CROSSING WEST VA WHILE ENCOUNTERING DRY AIR PER CURRENT DEWPOINTS. LATEST HRRR AND THE HIRES-ARW CATCH ON TO THIS PRETTY WELL AND DON`T SHOW MUCH ADDED COVERAGE UNTIL THE FRONT ARRIVES EARLY THIS AFTERNOON OVER THE FAR WEST. SHOULD THEN SEE A NARROW SWATH OF SNOW ATTEMPT TO CROSS FROM WEST TO EAST ESPCLY BETWEEN 18Z-23Z WHEN THE 85H BOUNDARY SURGES THROUGH UNDER PASSING SHORTWAVE ENERGY IN THE BASE OF THE 5H TROUGH. WITHIN THIS PERIOD ALSO EXPECT SOME MORE EAST-WEST ORIENTED BANDS TO DEVELOP BEHIND THE MAIN AXIS OF SNOW. LATEST SNOW SQUALL PARAMETER SUGGESTS THE HEAVIEST BURST OF SNOW ALONG THE WESTERN SLOPES WITH SOME OF THE WIND BLOWN ACCUMULATING SNOW LIKELY MAKING IT OUT TOWARD THE BLUE RIDGE IN SPOTS. LATEST 12Z NAM STILL SUPPORTING A FEW INCHES FAR NW AND 1-3 INCHES FROM BLF TO HSP AND POINTS WEST SO KEEPING THOSE HEADLINES OVER SOUTHEAST WEST VA WITH LITTLE CHANGE FOR NOW. STEEP LAPSES ALSO SUPPORT SOME SHOWERY NATURE COVERAGE MAKING IT EAST OF THE MOUNTAINS GIVEN SUCH STRONG WESTERLY FLOW ALOFT WITH NCAR PTYPE PROGS INDICATING BRIEF RAIN BEFORE QUICK COOLING CAUSES A CHANGE TO SNOW SHOWERS EVEN WITH TEMPS WELL ABOVE FREEZING. THUS EXTENDED LIGHT AMOUNTS OUT TO THE BLUE RIDGE ESPCLY GIVEN MID/LATE AFTERNOON TIMING. THIS IS WHERE THE MAIN CONCERN EXISTS WITH INITIAL MELTING...THEN A QUICK DROP BELOW FREEZING FOLLOWED BY A LIGHT SNOW COATING ON TOP. PLAN TO ADDRESS THIS WITH SPECIAL WEATHER STATEMENTS LATER PENDING THE DEGREE OF COVERAGE THAT COULD WARRANT A BRIEF HEADLINE. KEPT HIGH TEMPS CLOSE TO PREVIOUS EXCEPT LOWERED A BIT OUT WEST WHERE EARLY CLOUDS LIKELY TO KEEP VALUES COLDER. WINDS THE OTHER CONCERN AND JUST HOW DEEP MIXING WILL BE GIVEN CLOUDS BUT ALSO A QUICK CHANGE IN 85H TEMPS ALONG WITH A 40-45 KT JET. LOOKS LIKE A SURGE TO ADVISORY LEVELS LIKELY WHERE THE ADVISORY IS ALREADY ONGOING WITH A BRIEF INCREASE TO NEAR CRITERIA FOR AN HOUR OR TWO EVEN IN THE PIEDMONT WITH THE FRONT AND POSSBIBLE MOMENTUM MIX DOWN WITH ANY SHOWERS. FOR NOW SINCE APPEARS WILL BE A SHORT EVENT...WILL HOLD OFF ADDING A WIND ADVISORY EAST OF THE MOUNTAINS TO SEE HOW THINGS UNFOLD EARLY ON...WHILE BEEFING UP SPEEDS ESPCLY ALONG THE FOOTHILLS AND SPOTS ACROSS THE SOUTH. PREVIOUS DISCUSSION AS OF 345 AM EST TUESDAY... ACTIVE WEATHER THIS PERIOD...WITH THREAT OF ACCUMULATING SNOW SHOWERS AND SNOW SQUALLS OVER THE WV MTNS THIS AFTERNOON AND EVENING...ALONG WITH STRONG WIND GUSTS BEHIND THE ARCTIC FRONT. LOOKING AT INCREASING CLOUDS THIS MORNING. REGIONAL RADAR SHOWED LIGHT RETURNS AS FAR EAST AS HTS WV...WITH MODELS ON TRACK IN BRINGING SNOW SHOWERS INTO WV MTNS AND ALLEGHANYS BY MID TO LATE MORNING. THE BEST LIFT AND INSTABILITY WITH THIS SYSTEM SHOULD ARRIVE AFTER 2PM AND LAST UNTIL 9PM. CROSS SECTIONS AND SNOW SQUALL PARAMETERS INDICATE ENOUGH FRONTOGENETICAL FORCING WITH THE SURGE OF COLDER AIR WITH THE FRONT TO PRODUCE A FEW SNOW SQUALLS OVER THE WV MTNS AND PERHAPS INTO ADJACENT PORTIONS OF THE ALLEGHANY HIGHLANDS AND MTN EMPIRE OF SW VA AROUND 21Z-00Z TODAY. THE TRACK OF THE UPPER VORT FAVORS BEST SNOW ACCUMULATIONS ALONG AND NORTH OF A BKW-HSP LINE. THIS TRACK AND THE STRENGTH/TIMING OF THIS SYSTEM SHOULD SEND SNOW SHOWERS/FLURRIES AS FAR EAST AS LYNCHBURG AND APPOMATTOX THIS AFTERNOON...WITH SOME RAIN MIXED IN EARLY BEFORE 8H TEMPS CRASH BY 00Z. AT THIS TIME...ACCUMULATIONS WILL RANG FROM 2 TO 5 INCHES FROM FLAT TOP WV TO WRN GREENBRIER WHICH TAKES INTO ACCOUNT A LIMITED WINDOW OF UPSLOPE BEHIND THE FRONT THIS EVENING...AS THINK THE MOISTURE WILL DRY UP FAST GIVEN LACK OF UPSTREAM TRAJECTORY OFF THE LAKES. THE 1 INCH LINE WILL REACH LEWISBURG WV TO PRINCETON WV...WITH ISOLATED 1 INCH + AMOUNTS POSSIBLE ACROSS THE HIGHER PEAKS OF THE NEW RIVER VALLEY INTO THE NC MTNS...LIKE MOUNTAIN LAKE...MT ROGERS. A DUSTING OF SNOW IS POSSIBLE AS FAR EAST AS THE BLUE RIDGE INTO PORTIONS OF THE VA FOOTHILLS NORTH OF HIGHWAY 460. TIMING OF THE COLDER AIR FAVORS A NORMAL DIURNAL CURVE FOR MOST OF THE FORECAST AREA WITH FALLING TEMPS AFTER 3-4PM IN THE MTNS. HIGH TEMPS WILL RANGE FROM THE LOWER TO MID 30S FAR WEST TO UPPER 30S NEW RIVER VALLEY...MID TO UPPER 40S ROANOKE EAST TO THE PIEDMONT WITH SOME AREAS LIKE DANVILLE/SOUTH BOSTON REACH 50. AS FOR WINDS THE COLD ADVECTION HITS BY 21Z BEHIND THE FRONT WITH 45+KT 8H JET MOVING ACROSS WITH PRESSURE RISES OF 5-9MB...HIGHEST IN NRN VA/SHENANDOAH VALLEY ENDING AT 00Z. THIS WILL BE ENOUGH TO BRING 50 MPH WIND GUSTS TO RIDGES OF NW NC UP THE BLUE RIDGE OF VA INCLUDING THE RIDGES OF FAR SW VA. THIS WIND EVENT LOOKS TO BE IN A SMALL WINDOW FROM 21Z/5PM TIL 03Z/10PM...BUT TIMING OF THE FRONT MAY BRING STRONGER GUSTS EARLIER TO THE MTNS OF FAR SW VA/NW NC...LINGERING TIL MIDNIGHT OVER THE HIGHER PEAKS OF THE ALLEGHANYS. THEREFORE HAVE HOISTED A WIND ADVISORY FOR MUCH OF THE AREA ALONG/WEST OF THE BLUE RIDGE FROM NOON TODAY TIL MIDNIGHT TONIGHT. AS WE HEAD PAST MIDNIGHT...SNOW SHOWERS AND WINDS TAPER OFF WITH CLEAR SKIES OVER MOST OF THE AREA. WITH SNOW COVER EXPECTED IN THE MTNS LOWS OVER SE WV COULD REACH THE SINGLE DIGITS. LOWS OVER MOST OF THE WEST WILL BE IN THE TEENS...WITH LOWER 20S EAST. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 AM EST TUESDAY... HIGH PRESSURE WILL BUILD EAST INTO OUR REGION WEDNESDAY AND SLIDE OFF THE COAST ON THURSDAY. MOISTURE SLOWLY RETURNS THURSDAY NIGHT AHEAD OF LOW PRESSURE TO THE SOUTH AND WEST. RAIN IS EXPECTED FOR THE END OF THE WORKWEEK. FLOW BECOME MORE ZONAL WEDNESDAY AS THE COLDEST AIR ALOFT EXITS TO THE RIGHT. SUNSHINE INCREASES AS HIGH PRESSURE BUILDS ACROSS THE MOUNTAINS. HIGH TEMPERATURES WEDNESDAY WILL REMAIN COOL WITH READINGS FROM AROUND 20 DEGREES IN THE NORTHWEST MOUNTAINS TO NEAR 40 DEGREES IN THE PIEDMONT. A 500MB SHORTWAVE SLIDES BY TO THE NORTH LATER WEDNESDAY NIGHT INTO EARLY THURSDAY RESULTING IN SOME ADDITIONAL CLOUDS/MOISTURE MAINLY NORTHWEST. THIS SHOULD FLATTEN THE HIGH AND PUSH THE HIGH TO THE SOUTH. AN ISOLATED SNOW SHOWER OR SNOW FLURRIES MAY BE POSSIBLE IN THE NORTHWEST. OTHERWISE...LOOKS QUITE DRY WITH WESTERLY FLOW. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE MID 20S IN THE PIEDMONT. THE 1023 MB SURFACE HIGH STARTS TO SHIFT OFFSHORE THURSDAY AS HEIGHTS RISE WITH THE 5H TROUGH LIFTING BACK NORTH LEAVING AN ENSUING STRONG WESTERLY GRADIENT IN PLACE. STRONG WARM ADVECTION IS EXPECTED WITH A GOOD 5-8C INCREASE IN FORECAST 85H TEMPERATURES. HIGH TEMPERATURES WILL WARM INTO THE UPPER 30S IN THE MOUNTAINS TO NEAR 50 DEGREES IN THE PIEDMONT. AS SURFACE HIGH PRESSURE SHIFTS FARTHER OFFSHORE THURSDAY NIGHT...A RETURN SOUTHERLY FLOW WILL DEVELOP AHEAD OF LOW PRESSURE TO THE SOUTH AND WEST. LOW TEMPERATURES THURSDAY NIGHT WILL GENERALLY BE IN THE MID 20S TO THE LOWER 30S. LOW PRESSURE FROM THE GULF OF MEXICO WILL TRAVEL NORTHEAST FRIDAY AND REACH THE VIRGINIA CAPES BY FRIDAY NIGHT. THERE STILL REMAINS SOME DIFFERENCE IN THE MODELS REGARDING ANY PHASING WITH THE NORTHERN STREAM 5H TROUGH LIFTS THROUGH THE OHIO VALLEY FRIDAY NIGHT. IN ANY CASE...MOISTURE STARTS IN THE SOUTH AND SPREAD NORTHWARD ON FRIDAY. HIGHS ON FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT. AS THE LOW CENTER PUSH NORTHEAST OFF THE JERSEY SHORE FRIDAY NIGHT...DRIER AIR WILL PUSH NORTH INTO SOUTHEAST PORTIONS OF FORECAST AREA. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE THE UPPER 20S IN THE MOUNTAINS TO THE MID 30S IN THE PIEDMONT. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... AS OF 300 AM EST TUESDAY... BROAD TROUGHING WILL REMAIN OVER THE EAST THROUGH THE WEEKEND...AS A DEEP UPPER VORTEX SINKS DOWN FROM CANADA AND ROTATES OVER THE GREAT LAKES. RAIN TAPERS OFF EAST OF THE BLUE RIDGE SATURDAY...AS A TRAILING DRY SLOT PUNCHES IN. NORTHERN STREAM UPPER LOW WILL THEN BE THE MAIN PLAYER FROM LATER SATURDAY INTO SUNDAY NIGHT WITH PERIODIC UPSLOPE SNOW SHOWERS LIKELY WEST AS DEEPER COLD ADVECTION ARRIVES AND MOISTURE LINGERS. APPEARS BEST CHANCES OF SNOW SHOWERS WILL BE SUNDAY AS THE CORE OF THE UPPER TROUGH PIVOTS THROUGH AIDED BY ANOTHER MID LEVEL WAVE PASSING DURING STRONG 85H COLD ADVECTION. SOME OF THESE SNOW/RAIN SHOWERS COULD EVEN CROSS THE MOUNTAINS SUNDAY AFTERNOON SO KEPT IN MENTION WITH LIKELY INCREASE IN LAPSES OUT EAST. OTRW TURNING BLUSTERY AND COLDER AGAIN OVER THE WEEKEND WITH MAINLY MOUNTAIN SNOW SHOWERS BEFORE TAPERING MONDAY UNDER WEAK HIGH PRESSURE AHEAD OF THE NEXT UPSTREAM WAVE. HIGHS MOSTLY 30S/40S AND LOWS TEENS/20S SUNDAY-MONDAY. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... AS OF 640 AM EST TUESDAY... EXPECT WORSENING CONDITIONS OVER THE MTN TERMINALS BY MIDDAY WITH SNOW SHOWERS BECOMING PREVALENT. MODERATE TO HEAVY SNOW SHOWERS ARE POSSIBLE AT BLF/LWB DURING THE 19-22Z TIME FRAME. SNOW SHOWERS MAY IMPACT ROA/BCB AS WELL WITH VSBYS BRIEFLY DIPPING TO UNDER 6SM. WINDS WILL BE ANOTHER ISSUE AS THEY PICK UP AHEAD OF THE FRONT FROM THE SW THEN TURN WEST BEHIND THE FRONT FIRST AT BLF/LWB AROUND 19-20Z...THEN ROA/BCB ANOTHER HOUR AFTER THAT...FINALLY CLEARING DAN/LYH BY 23Z. WIND SPEEDS WILL BE SUSTAINED FROM 12 TO 20 KTS WITH GUSTS AS HIGH AS 30-40KTS AT THE HIGHER ELEVATIONS AND ROA/BCB. WINDS WILL DIMINISH TO LESS THAN 20KTS AFTER 00Z WED...ESPECIALLY EAST OF THE BLUE RIDGE. MVFR CIGS WILL LIKELY PREVAIL NEAR THE ALLEGHANY FRONT THROUGH THE NIGHT TUESDAY NIGHT...BUT IMPROVE TO VFR ELSEWHERE WHERE NOT ALREADY SO. MEDIUM TO HIGH CONFIDENCE IN CEILINGS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN VISIBILITIES THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND SPEED/DIRECTION THROUGH THE TAF VALID PERIOD. .EXTENDED AVIATION DISCUSSION... WEDNESDAY HIGH PRESSURE BUILDS BACK IN...THOUGH LINGERING MVFR CEILINGS AT KBLF/KLWB MAY OCCUR EARLY. THE HIGH MOVES TO THE SOUTHEAST COAST THURSDAY AS WINDS BACK TO THE WSW. MOISTURE RETURNS AGAIN FRIDAY WITH POTENTIAL MVFR CEILINGS AND LIGHT PRECIPITATION...MAINLY LIQUID...BY FRIDAY EVENING...WHICH WILL PERSIST INTO SATURDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VAZ007-009>020- 022>024-035. NC...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ001-002-018. WV...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ044-507. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ042- 043-508. && $$ SYNOPSIS...JH/WP NEAR TERM...JH/WP SHORT TERM...KK LONG TERM...JH/KK AVIATION...RAB/WP
AREA FORECAST DISCUSSION
NWS ALBANY NY
509 PM EST TUE JAN 12 2016 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE REGION THIS EVENING PRODUCING SNOW SQUALLS. STRONG WINDS FOLLOWING THE SQUALL WILL FUNNEL COLD AIR INTO OUR AREA. THE STRONG WINDS WILL PERSIST INTO WEDNESDAY WITH LAKE EFFECT SNOW ACROSS THE WESTERN MOHAWK VALLEY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MAIN FEATURE TONIGHT WILL BE COLD FRONTAL PASSAGE AND ASSOCIATED SQUALL LINE. SOME LIGHTNING HAS BEEN OBSERVED WITH THIS SYSTEM AS IT HAS MOVED ACROSS WESTERN AND CENTRAL NEW YORK. TIMING THE FRONT VIA HRRR SIMULATED RADAR PUTS THE FRONT TO THE WESTERN MOHAWK VALLEY BY AROUND 6PM...CAPITAL DISTRICT BY 8PM AND TO WESTERN NEW ENGLAND BY ABOUT 9PM. THE SQUALL WILL FEATURE STRONG WINDS...HEAVY AND BLOWING SNOW WITH VISIBILITIES NEAR ZERO. ALTHOUGH SHORT-LIVED...SAY ABOUT 20 MINUTES IN ANY ONE LOCATION...NEAR BLIZZARD CONDITIONS WILL PREVAIL FOR THE BRIEF PERIOD OF SQUALL PASSAGE. TIMING OF THE SQUALL VIA THE HRRR RADAR REFLECTIVITY HAS BEEN INCORPORATED INTO THE HOURLY GRIDS. IN ADDITION...SPECIAL WEATHER STATEMENTS WILL BE USED TO TRACK THE TRANSIT OF THE SQUALL ACROSS THE AREA. SNOWFALL FROM THE SQUALL WILL BE NO MORE THAN AN INCH. A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THE SOUTHERN ADIRONDACKS AND SOUTHERN GREEN MOUNTAINS THROUGH 10 PM THIS EVENING. SNOW ASSOCIATED WITH THE CLIPPER WARM FRONT HAS BEEN ONGOING TODAY IN THE ADVISORY ZONE. SNOWFALL REPORTS OF 4-6 INCHES HAVE BEEN RECEIVED IN HAMILTON COUNTY. ELSEWHERE REPORTS HAVE SCARCE. ISENTROPIC ASCENT WILL BE WEAKENING INTO THE EVENING. STILL A BURST OF SNOW TO GO FOR THE SOUTHERN GREENS. NEXT ISSUE UP TONIGHT WILL BE THE WIND. A WIND ADVISORY HAS BEEN ISSUED FOR THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. IN THE WAKE OF THE SQUALL...STRONG ISENTROPIC DESCENT IN COLD AIR ADVECTION WILL LEAD TO A WELL MIXED LAYER TAPPING INTO 50 KNOT WINDS. THE STRONGEST WINDS WILL BE IN CHANNELED FLOW DOWN THE MOHAWK VALLEY. HERE WE ARE LOOKING FOR WINDS OF 20-30 MPH WITH GUSTS TO 50 MPH. IN OTHER AREAS WITHIN THE ADVISORY LOOK FOR WINDS AROUND 20 MPH WITH GUSTS OF 45-50 MPH. STRONGEST WINDS LOOK TO BE DURING DAYLIGHT HOURS WEDNESDAY MORNING. THE ADVISORY RUNS FROM 1AM TONIGHT TO 5PM WEDNESDAY. LAKE EFFECT SNOW WARNINGS/ADVISORIES FOR THE WESTERN MOHAWK VALLEY...SCHOHAIRE COUNTY...AND HELDERBERGS KICK IN THIS EVENING AND CONTINUE INTO WEDNESDAY EVENING. SEVERE INSTABILITY IS REALIZED WITH LAKE/850MB TEMPS DELTA T/S AROUND 22C. UNIDIRECTIONAL WIND ALIGNS ALONG 290-300 VECTOR. THIS PROMOTES LAKE EFFECT INTO SOUTHERN HERKIMER/SCHOHAIRIE/HELDERBERGS WHERE HEADLINES ARE FLYING. ALTHOUGH KVIE INLAND EXTENT TOOL SHOWS RESPECTABLE INLAND PENETRATION OF ABOUT 90-95 MILES GIVEN TRAJECTORY THIS REACHES SOUTHERN HERKIMER BUT NOT TOO MUCH PAST THERE. MODELS DO DEPICT BANDS MAKING INTO ADVISORY/WARNING AREAS...ALTHOUGH QPF IS ON THE LIGHT SIDE. WILL CONTINUE TO MAINTAIN WARNINGS AND ADVISORIES. FORECAST SNOWFALL IS 6-12 INCHES IN SOUTHERN HERKIMER AND 3-6 INCHES IN ADVISORY AREAS. TEMPERATURES TONIGHT WILL SLIDE MAINLY INTO THE TEENS AND 20S...SOME SINGLE DIGITS IN ADIRONDACKS. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... HAVE ADDRESSED WEDNESDAY ABOVE. AS FAR AS THE REMAINDER OF THE SHORT TERM PERIOD GOES BROAD CYCLONIC WEST NORTHWEST FLOW WILL KEEP TEMPERATURES ON THE COLD SIDE OF NORMAL INTO THURSDAY. RISING HEIGHTS AND LIGHT SOUTHWEST WINDS WILL BRING TEMPERATURES ABOVE NORMAL THURSDAY NIGHT INTO FRIDAY. SOME LIGHT LAKE EFFECT SNOW MAY IMPACT NORTHERN HERKIMER AND HAMILTON COUNTIES ON THURSDAY. A DEVELOPING WARM FRONT ASSOCIATED WITH A STORM SYSTEM IN THE GREAT LAKES ON FRIDAY COULD BRING SOME LIGHT PRECIPITATION TO NORTHERN AREAS ON FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... INITIALLY THE LONG TERM PORTION OF THE FORECAST WILL BE ACTIVE...DESPITE TEMPS REACHING SLIGHTLY ABOVE SEASONAL LEVELS. THEN...EXPECT A TREND TOWARD DRIER CONDITIONS...BUT TEMPS WILL FALL A BIT TO SLIGHTLY BELOW NORMAL. THE MOST CHALLENGING PORTION OF THE FORECAST APPEARS TO BE FRI NT- SUN AM. MODELS SEEM TO BE CONVERGING SOMEWHAT ON A SOLUTION FAVORING A COASTAL WAVE...EMANATING FROM THE GULF COAST REGION...WITH AN INLAND PRIMARY CENTER TRACKING TOWARD THE GREAT LAKES. ASSUMING THE COASTAL WAVE STRENGTHENS...AND DEVELOPS AS FAR NORTH AND WEST AS MOST MODELS CURRENTLY SUGGEST...THEN A PERIOD OF MODERATE TO PERHAPS LOCALLY HEAVY PRECIP IS POSSIBLE. HOWEVER...SHOULD THIS COASTAL WAVE BE WEAKER AND/OR TRACK SLIGHTLY FARTHER S AND E...THEN MUCH LIGHTER PRECIP WILL MOST LIKELY OCCUR. ALSO...THE THERMAL PROFILE IS A BIT IN QUESTION...ESP FOR AREAS SOUTH OF I-90...WHERE H925 TEMPS MAY INITIALLY BE ABOVE 0C. IF THIS OCCURS...THEN P-TYPE COULD BE RAIN...OR A RAIN/SNOW MIX FROM I-90 SOUTH...WITH MORE SNOW TO THE NORTH. THE POSSIBILITY OF MODERATE OR GREATER SNOWFALL AMTS WILL EXIST...ESP FOR AREAS N OF I-90 AND ACROSS HIGHER TERRAIN...ASSUMING THE COASTAL ENTITY STRENGTHENS AND TRACKS CLOSER TO THE COAST. THEREFORE...HAVE LIKELY TO CATEGORICAL POPS FOR LATE FRI NT THROUGH SATURDAY...THEN TAPERING TO CHC SAT NT-SUN. BEYOND SUNDAY...THE REMNANTS OF THE PRIMARY LOW ACROSS THE GREAT LAKES SHOULD MOVE ACROSS SUN-MON...WITH ADDITIONAL SNOW SHOWERS. THEN...COLDER AIR MOVES INTO THE REGION FOR MON-WED. ADDITIONAL LAKE EFFECT SNOWFALL WILL BE POSSIBLE ACROSS PORTIONS OF THE WESTERN ADIRONDACKS/MOHAWK VALLEY. SOME MODELS SUGGEST ANOTHER SOUTHERN STREAM FEATURE TRACKS TOWARD THE EAST COAST MON-TUE...BUT AT LEAST FOR NOW...SEEM TO INDICATE A TRACK FAR ENOUGH S AND E OF THE REGION TO LIMIT ANY IMPACTS TO SOME CLOUDS. AS FOR TEMPS...FRI NT/SAT AM MINS SHOULD FALL INTO THE 20S TO LOWER 30S...WARMEST ACROSS THE MID HUDSON VALLEY. ON SAT...MAX TEMPS SHOULD REACH THE LOWER/MID 30S IN VALLEYS...WITH UPPER 20S ACROSS HIGHER ELEVATIONS...ALTHOUGH SLIGHTLY COLDER MAX TEMPS COULD OCCUR IF HEAVIER PRECIP OCCURS EVEN IN VALLEY AREAS FROM I-90 NORTH. SAT NT/SUN AM MINS SHOULD FALL INTO THE 20S FOR MOST AREAS...PERHAPS SOME TEENS ACROSS THE ADIRONDACKS. FOR MON-TUE...MAX TEMPS SHOULD ONLY REACH THE TEENS ACROSS HIGHER ELEVATIONS...AND LOWER 20S IN VALLEYS. OVERNIGHT MIN TEMPS SHOULD FALL INTO THE SINGLE DIGITS TO LOWER TEENS...WITH SOME SUBZERO MINS POSSIBLE TUE NT ACROSS NORTHERN PORTIONS OF THE REGION. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/... LOW PRESSURE OVER THE NORTHERN GREAT LAKES WILL TRACK EASTWARD ACROSS NORTHERN NEW ENGLAND TONIGHT...AND OFF THE NEW ENGLAND COAST ON WEDNESDAY. A COLD FRONT ASSOCIATED WITH THIS LOW WILL TRACK EASTWARD ACROSS THE REGION THIS EVENING. THUS FAR...SNOW HAS ONLY AFFECTED KGFL...WHERE VSBYS ARE IFR. WE EXPECT THE MAIN IMPACTS FROM SNOW THROUGH 20Z/TUE TO REMAIN AT KGFL. THEREAFTER...ADDITIONAL SNOW SHOWERS ARE EXPECTED TO DEVELOP AT KPOU AND KPSF...WHICH MAY LEAD TO MVFR/IFR VSBYS...ESP BETWEEN 20Z- 22Z/TUE. AT KALB...IT APPEARS THAT THE BULK OF SNOW SHOWERS THROUGH THIS AFTERNOON SHOULD REMAIN MAINLY NORTH AND EAST OF THE TERMINAL...ALTHOUGH SOME LIGHTER SNOW SHOWERS/FLURRIES MAY PRODUCE PERIODS OF MVFR VSBYS AFTER 20Z. THE MAIN THREAT FOR SNOW OTHER THAN KGFL WILL BE WITH SNOW SQUALLS ASSOCIATED WITH A COLD FRONTAL PASSAGE BETWEEN ROUGHLY 23Z/TUE- 03Z/WED. A LINE OF SNOW SQUALLS WILL BE POSSIBLE DURING THIS WINDOW...AND COULD LEAD TO LIFR/VLIFR VSBYS. ALSO...CAN NOT COMPLETELY RULE OUT A RUMBLE OF THUNDER OR TWO WITHIN SOME OF THESE SQUALLS. AFTER 03Z/WED...SNOW SHOWERS SHOULD RAPIDLY DECREASE IN AREAL COVERAGE. HOWEVER...ATTENTION WILL THEN SHIFT TO A POTENTIAL LAKE EFFECT SNOWBAND...ESP BETWEEN 08Z/WED AND 16Z/WED. WITH A DEVELOPING W/NW WIND FLOW...IT IS POSSIBLE THAT A SNOWBAND EXTENDS FROM LAKE ONTARIO TO NEAR OR JUST SOUTH/WEST OF KALB. IFR/LIFR CONDITIONS BE POSSIBLE WITHIN THIS SNOWBAND. IT COULD ALSO IMPACT KPSF AS WELL DURING THIS TIME. WINDS WILL BE FROM THE SOUTH THIS AFTERNOON AT 8-12 KT...WITH OCCASIONAL GUSTS OF 20-25 KT POSSIBLE...ESP AT KALB. THEN...AS THE FRONT PASSES THIS EVENING...WINDS WILL SHIFT INTO THE WEST/NORTHWEST AND INCREASE TO 10-15 KT...ALONG WITH SOME GUSTS OF 30-35 KT...ESP AT KALB AND KPSF...THROUGH 18Z/WED...WITH EVEN STRONGER GUSTS POSSIBLE. ALSO...WITHIN THE HEAVIER SNOW SQUALLS...WINDS COULD BRIEFLY GUST UP TO 35-40 KT THIS EVENING. OUTLOOK... WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN. SATURDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN...SN. SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... SEASONABLE TEMPERATURES EXPECTED TO PERSIST THROUGH NEXT WEEK. THIS WILL ALLOW FOR ICE TO FORM ON BODIES OF WATER ALONG WITH SNOW. 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...WIND ADVISORY FROM 1 AM TO 5 PM EST WEDNESDAY FOR CTZ001-013. NY...WIND ADVISORY FROM 1 AM TO 5 PM EST WEDNESDAY FOR NYZ038>040- 047>054-058>061-063>066. LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST WEDNESDAY FOR NYZ039- 040-047-048-051. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ032-033-042-082. LAKE EFFECT SNOW WARNING UNTIL 7 PM EST WEDNESDAY FOR NYZ038. MA...WIND ADVISORY FROM 1 AM TO 5 PM EST WEDNESDAY FOR MAZ001-025. VT...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR VTZ014. && $$ SYNOPSIS...OKEEFE NEAR TERM...OKEEFE SHORT TERM...OKEEFE LONG TERM...KL AVIATION...KL HYDROLOGY...IAA/11
AREA FORECAST DISCUSSION
NWS JACKSON KY
306 PM EST TUE JAN 12 2016 .UPDATE... ISSUED AT 1104 AM EST TUE JAN 12 2016 SNOW EVENT GOT A LATE START...BUT IS UNDERWAY OVER THE NORTHERN PART OF THE FORECAST AREA. OBS...RADAR TRENDS...AND NEW 12Z MODEL DATA SUPPORT LIGHT ACCUMULATIONS OF AN INCH AND LOCALIZED TWO INCHES IN OUR NORTHERN COUNTIES TODAY. SNOW WILL BE INTERMITTENT IN NATURE...AND COULD BRIEFLY COME DOWN INTENSELY. SOME LIGHTNING HAS EVEN BEEN OBSERVED IN SNOW SHOWERS OVER SOUTHERN INDIANA THIS MORNING. FURTHER SOUTH...THE END RESULT IS MORE QUESTIONABLE. WITH AN ADVISORY ALREADY IN PLACE...WILL LEAVE IT...BUT JUST MENTION LOCALIZED ACCUMULATIONS UP TO AN INCH FROM LOCALIZED HEAVIER SNOW SHOWERS. UPDATE ISSUED AT 645 AM EST TUE JAN 12 2016 LIGHT SNOW AND FLURRIES ARE CROSSING MAINLY NORTHERN PARTS OF THE AREA WITH LITTLE IN THE WAY OF ACCUMULATIONS REPORTED. A MORE INTENSE BATCH OF SNOW WILL MOVE IN LATER IN THE MORNING. HAVE TIMED THIS BAND THROUGH IN THE GRIDS. ALSO UPDATED THE HOURLY T AND TD GRIDS PER THE LATEST CONDITIONS AND TRENDS...PARTICULARLY MILDER ON TEMPS DUE TO THE STRENGTHENING SOUTHWEST WINDS AHEAD OF THE FRONT. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 07Z SFC ANALYSIS SHOWS A DEEPENING AREA OF LOW PRESSURE MOVING THROUGH THE CENTRAL GREAT LAKES. THIS IS DRIVING AN ARCTIC COLD FRONT INTO THE NORTHWEST PORTION OF THE OHIO VALLEY EARLY THIS MORNING. CLOSER TO HOME...A DECENT PRESSURE GRADIENT EXISTS OVER KENTUCKY BETWEEN THE LOW TO THE NORTH AND HIGH PRESSURE ALONG THE GULF COAST. THIS IS ALREADY MANIFESTING IN SOME BREEZY SOUTHWEST WINDS THROUGH THE BLUEGRASS HELPING TO KEEP NIGHTTIME TEMPERATURES RELATIVELY MILD FOR MUCH OF THE AREA. WHILE MOST PLACES ARE SEEING LOW AND MID 30S FOR THE JKL CWA...A FEW SHELTERED EASTERN VALLEYS REMAIN IN THE MID 20S. WINDS ARE GUSTING OVER THE WESTERN PARTS OF THE AREA REACHING THE 25 TO 30 MPH RANGE AT TIMES. ALTHOUGH A DRY AIR MASS IS IN PLACE THE SOUTHERLY WINDS WILL TRY TO BRING IN MORE MOISTURE THROUGH THE FIRST PART OF THE MORNING AHEAD OF THE ARCTIC FRONT. MEANWHILE...DEW POINTS THROUGHOUT THE AREA ARE RUNNING IN THE UPPER SINGLE DIGITS TO MID TEENS NORTHEAST TO THE MIDDLE AND UPPER TEENS SOUTH. A DECK OF MID LEVEL CLOUDS COVER THE BULK OF EASTERN KENTUCKY WITH EVEN A FEW VERY LIGHT SNOW SHOWERS AND FLURRIES PASSING THROUGH. THE MODELS ARE IN EXCELLENT AGREEMENT WITH THE UPPER AIR PATTERN THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE CORE OF A FAIRLY DEEP TROUGH...THAT IS MOVING INTO THE OHIO VALLEY...TO PUNCH THROUGH KENTUCKY BY EARLY AFTERNOON. THIS IS DRIVEN BY A 135 TO 140 KT 300 MB JET ARCING INTO THE REGION THIS MORNING WITH A GOOD AMOUNT A UPPER LEVEL DIVERGENCE PROGGED TO PASS OVER EAST KENTUCKY BETWEEN 09 AND 21Z. IT WILL BE A QUICK HITTING MID LEVEL WAVE...THOUGH...AS BY 00Z IT WILL BE OFF THE MID ATLANTIC COAST ALLOWING HEIGHTS TO RELAX LOCALLY AND RISE INTO THE DAY WEDNESDAY. A COUPLE OF WEAKER WAVES DO FOLLOW IN NORTHWEST FLOW AND LOOK TO PASS ABOVE EAST KENTUCKY FOR WEDNESDAY. GIVEN THE GOOD MODEL MATCH-UP WILL FOLLOW SUIT BUT FAVOR THE SPECIFICS FROM THE HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS... ALONG WITH A HEALTHY DOSE OF CLIMATOLOGY FOR THESE SITUATIONS IN EASTERN KENTUCKY. SENSIBLE WEATHER WILL FEATURE A DYNAMIC AND ACTIVE WEATHER DAY AS AN ARCTIC BOUNDARY PASSES THROUGH THE CWA BY LATE IN THE AFTERNOON. WHILE LIGHT SNOW WILL BE POSSIBLE AHEAD OF THIS BOUNDARY...THE MAIN SHOW WILL BE JUST ALONG AND BEHIND IT AS IT HELPS TO MAXIMIZE THE MID LEVEL LAPSE RATES AND FIND JUST ENOUGH CAPE TO BECOME CONVECTIVE IN NATURE. GIVEN THE BACKGROUND PRESSURE AND HEIGHT GRADIENTS IN THE THE LOWER LEVELS OF THE ATMOSPHERE THE HIGHER WINDS ALOFT SHOULD BE ABLE TO BE TAPPED BY THE CONVECTIVE CELLS LEADING TO GUSTY WINDS AT THE SFC. THIS COMBINED WITH THE SNOW SHOWERS WILL MEAN RAPIDLY CHANGING VISIBILITY IN GUSTY SNOW SQUALLS. FINALLY...GIVEN THE COLD STARTING POINT FOR ROAD SFCS... EXPECT ANY SNOW THAT FALLS TO POTENTIALLY ACCUMULATE ON THE ROADS...WITH LIMITED HELP FROM INSOLATION DURING THE DAYLIGHT HOURS. SO...ALTHOUGH QPF WILL BE RATHER LIMITED WITH THIS FRONT... THE IMPACT FROM THESE LIGHT EVENTS CAN BE AS LARGER OR LARGER THAN BIGGER WINTER STORMS SO WILL CONTINUE TO HIT IT HARD WITH A WSW ADVISORY ACROSS THE BULK OF OUR CWA TODAY...STARTING EARLIER IN THE WEST AND LINGERING LONGER IN THE EAST. SNOW AMOUNTS SHOULD BE MAXIMIZED...WITH A POTENTIAL FOR UP TO 2 INCHES...IN THE NORTHERN PARTS OF THE CWA AND IN THE HIGHEST TERRAIN NEAR THE VIRGINIA BORDER. THE SNOW WILL END FROM WEST TO EAST IN THE EVENING...WITH A DROP OFF IN THE SQUALLINESS AFTER SUNSET. LOOK FOR A HINT OF UPSLOPE COMPONENT INTO THE NIGHT TO KEEP A SMALL THREAT OF SNOW SHOWERS AND FLURRIES GOING IN THE FAR EAST THROUGH EARLY WEDNESDAY MORNING...BUT ANY ADDITIONAL ACCUMULATIONS WILL BE MARGINAL AFTER THIS EVENING. CHILLY HIGH PRESSURE THEN SPREADS INTO THE STATE WITH LOW TEMPERATURES NEARING THE SINGLE DIGITS IN THE NORTHWEST BY DAWN WEDNESDAY. WINDS STILL BRISK WILL YIELD WIND CHILLS DOWN NEAR ZERO IN SPOTS AND MAINLY SINGLE DIGITS ELSEWHERE AT DAWN WEDNESDAY. READING WILL THEN STRUGGLE TO RISE OUT OF THE 20S ON WEDNESDAY DESPITE A RETURN OF SOME SUNSHINE. IN FACT...THE SUNSHINE WILL LIKELY BE LIMITED BY SOME MID AND HIGH LEVEL CLOUDS INBOUND FROM THAT NEXT...WEAKER...WAVE PASSING BY AT MID LEVELS. ACCORDINGLY...HAVE NOT ZEROED OUT POPS FOR LATER WEDNESDAY AS A COUPLE OF FLURRIES CANNOT BE RULED OUT FROM THIS FEATURE WHEN IT BRUSHES BY FROM WEDNESDAY AFTERNOON INTO THE EVENING. USE THE SHORTBLEND AS A STARTING POINT FOR TEMPERATURES AND DEW POINTS THROUGH THE EVENING WITH THE SUPERBLEND USED THEREAFTER. MADE ONLY MINOR ADJUSTMENTS FOR SOME TERRAIN DISTINCTIONS TONIGHT...AS THE GRIDS LOOKED REASONABLE. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF THE MOS...WHICH IS TYPICAL FOR THIS TYPE OF SITUATION. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 306 PM EST TUE JAN 12 2016 ZONAL FLOW WILL RETURN THROUGH THE SECOND HALF OF THE WEEK...ALLOWING FOR A WARMING TREND INTO THE END OF THE WEEK. THIS WARM UP WILL BE BRIEF HOWEVER...AS ANOTHER DEEP UPPER LEVEL TROUGH DIGS ACROSS THE EASTERN CONUS. THIS WILL BRING MORE ACTIVE WEATHER AS WE HEAD INTO THE UPCOMING WEEKEND. VERY MILD WEATHER WILL RETURN FOR THE STAT OF THE EXTENDED PERIOD WITH HIGHS BACK ABOVE NORMAL AS HIGHS THURSDAY AND FRIDAY EXCEED 50.A POTENT MID LEVEL WAVE WILL THEN EMERGE FROM THE SOUTHERN PLAINS FRIDAY HELPING TO GENERATE A LOW PRESSURE SYSTEM OVER THE MID MISSISSIPPI RIVER VALLEY. EASTERN KENTUCKY WILL REMAIN ON THE WARM SIDE OF THIS SYSTEM...WITH PRIMARILY RAIN EXPECTED. MODELS ARE COMING INTO AGREEMENT THAT RAIN WILL OVERSPREAD EASTERN KENTUCKY FRIDAY AFTERNOON THROUGH FRIDAY EVENING. THIS SYSTEM WILL SEND A COLD FRONT ACROSS THE AREA LATE FRIDAY NIGHT...WITH COLDER THAN NORMAL WEATHER RETURNING FOR THE WEEKEND THROUGH NEXT WEEK. SOME MOISTURE MAY LINGER ON SATURDAY WITH SOME SNOW SHOWERS A POSSIBILITY. WARM GROUND AND TEMPERATURES STILL SLIGHTLY ABOVE FREEZING WILL LIKELY LIMIT ANY SNOWFALL ACCUMULATIONS AGAIN. MODELS ARE DRYING THINGS OUT NOW INTO SATURDAY NIGHT. MODEL UNCERTAINTY INCREASES INTO SUNDAY...WITH BOTH GFS AND ECMWF SHOWING A POSSIBILITY OF SOME SNOW ON SUNDAY BUT FOR DIFFERENT REASONS. FOR NOW...GOING TO MAINTAIN A SLIGHT CHANCE OF SNOW ON SUNDAY...BUT NOT ANTICIPATED MUCH ACCUMULATIONS. WITH MODEL UNCERTAINTY EVEN GREATER INTO NEXT WEEK...OPTED TO GO WITH A DRY FORECAST AND STAY WITH THE MORE CONSISTENT (DRIER) ECMWF. HOWEVER...TEMPERATURES WILL REMAIN MUCH BELOW NORMAL UNDER THIS SCENARIO. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 144 PM EST TUE JAN 12 2016 A LINE OF CONVECTIVE SNOW WILL PROGRESS SOUTHEAST ACROSS THE AREA THIS AFTERNOON...MARKING THE END OF SIGNIFICANT SNOW. THE SNOW MAY BE BRIEFLY INTENSE WITH VSBY LESS THAN A HALF MILE...AND ACCOMPANIED BY WESTERLY WIND GUSTS TOPPING 25 KTS. BEHIND THE CONVECTIVE SNOW BAND...VFR WILL RETURN FOR MOST LOCATIONS. HOWEVER...SOME MVFR CEILINGS MAY PERSIST AT TIMES TONIGHT IN FAR NORTHERN AND EASTERN PORTIONS OF THE AREA AROUND MOREHEAD TO PIKEVILLE. WINDS WILL DIMINISH THIS EVENING. VFR WITH LIGHT WINDS IS EXPECTED DURING THE DAY ON WEDNESDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044- 050>052-058>060-068-069-079-080-086>088-104-106>117-119. WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR KYZ118- 120. && $$ UPDATE...HAL SHORT TERM...GREIF LONG TERM...KAS AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
144 PM EST TUE JAN 12 2016 .UPDATE... ISSUED AT 1104 AM EST TUE JAN 12 2016 SNOW EVENT GOT A LATE START...BUT IS UNDERWAY OVER THE NORTHERN PART OF THE FORECAST AREA. OBS...RADAR TRENDS...AND NEW 12Z MODEL DATA SUPPORT LIGHT ACCUMULATIONS OF AN INCH AND LOCALIZED TWO INCHES IN OUR NORTHERN COUNTIES TODAY. SNOW WILL BE INTERMITTENT IN NATURE...AND COULD BRIEFLY COME DOWN INTENSELY. SOME LIGHTNING HAS EVEN BEEN OBSERVED IN SNOW SHOWERS OVER SOUTHERN INDIANA THIS MORNING. FURTHER SOUTH...THE END RESULT IS MORE QUESTIONABLE. WITH AN ADVISORY ALREADY IN PLACE...WILL LEAVE IT...BUT JUST MENTION LOCALIZED ACCUMULATIONS UP TO AN INCH FROM LOCALIZED HEAVIER SNOW SHOWERS. UPDATE ISSUED AT 645 AM EST TUE JAN 12 2016 LIGHT SNOW AND FLURRIES ARE CROSSING MAINLY NORTHERN PARTS OF THE AREA WITH LITTLE IN THE WAY OF ACCUMULATIONS REPORTED. A MORE INTENSE BATCH OF SNOW WILL MOVE IN LATER IN THE MORNING. HAVE TIMED THIS BAND THROUGH IN THE GRIDS. ALSO UPDATED THE HOURLY T AND TD GRIDS PER THE LATEST CONDITIONS AND TRENDS...PARTICULARLY MILDER ON TEMPS DUE TO THE STRENGTHENING SOUTHWEST WINDS AHEAD OF THE FRONT. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 07Z SFC ANALYSIS SHOWS A DEEPENING AREA OF LOW PRESSURE MOVING THROUGH THE CENTRAL GREAT LAKES. THIS IS DRIVING AN ARCTIC COLD FRONT INTO THE NORTHWEST PORTION OF THE OHIO VALLEY EARLY THIS MORNING. CLOSER TO HOME...A DECENT PRESSURE GRADIENT EXISTS OVER KENTUCKY BETWEEN THE LOW TO THE NORTH AND HIGH PRESSURE ALONG THE GULF COAST. THIS IS ALREADY MANIFESTING IN SOME BREEZY SOUTHWEST WINDS THROUGH THE BLUEGRASS HELPING TO KEEP NIGHTTIME TEMPERATURES RELATIVELY MILD FOR MUCH OF THE AREA. WHILE MOST PLACES ARE SEEING LOW AND MID 30S FOR THE JKL CWA...A FEW SHELTERED EASTERN VALLEYS REMAIN IN THE MID 20S. WINDS ARE GUSTING OVER THE WESTERN PARTS OF THE AREA REACHING THE 25 TO 30 MPH RANGE AT TIMES. ALTHOUGH A DRY AIR MASS IS IN PLACE THE SOUTHERLY WINDS WILL TRY TO BRING IN MORE MOISTURE THROUGH THE FIRST PART OF THE MORNING AHEAD OF THE ARCTIC FRONT. MEANWHILE...DEW POINTS THROUGHOUT THE AREA ARE RUNNING IN THE UPPER SINGLE DIGITS TO MID TEENS NORTHEAST TO THE MIDDLE AND UPPER TEENS SOUTH. A DECK OF MID LEVEL CLOUDS COVER THE BULK OF EASTERN KENTUCKY WITH EVEN A FEW VERY LIGHT SNOW SHOWERS AND FLURRIES PASSING THROUGH. THE MODELS ARE IN EXCELLENT AGREEMENT WITH THE UPPER AIR PATTERN THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL DEPICT THE CORE OF A FAIRLY DEEP TROUGH...THAT IS MOVING INTO THE OHIO VALLEY...TO PUNCH THROUGH KENTUCKY BY EARLY AFTERNOON. THIS IS DRIVEN BY A 135 TO 140 KT 300 MB JET ARCING INTO THE REGION THIS MORNING WITH A GOOD AMOUNT A UPPER LEVEL DIVERGENCE PROGGED TO PASS OVER EAST KENTUCKY BETWEEN 09 AND 21Z. IT WILL BE A QUICK HITTING MID LEVEL WAVE...THOUGH...AS BY 00Z IT WILL BE OFF THE MID ATLANTIC COAST ALLOWING HEIGHTS TO RELAX LOCALLY AND RISE INTO THE DAY WEDNESDAY. A COUPLE OF WEAKER WAVES DO FOLLOW IN NORTHWEST FLOW AND LOOK TO PASS ABOVE EAST KENTUCKY FOR WEDNESDAY. GIVEN THE GOOD MODEL MATCH-UP WILL FOLLOW SUIT BUT FAVOR THE SPECIFICS FROM THE HIGHER RESOLUTION HRRR AND NAM12 FOR WEATHER DETAILS... ALONG WITH A HEALTHY DOSE OF CLIMATOLOGY FOR THESE SITUATIONS IN EASTERN KENTUCKY. SENSIBLE WEATHER WILL FEATURE A DYNAMIC AND ACTIVE WEATHER DAY AS AN ARCTIC BOUNDARY PASSES THROUGH THE CWA BY LATE IN THE AFTERNOON. WHILE LIGHT SNOW WILL BE POSSIBLE AHEAD OF THIS BOUNDARY...THE MAIN SHOW WILL BE JUST ALONG AND BEHIND IT AS IT HELPS TO MAXIMIZE THE MID LEVEL LAPSE RATES AND FIND JUST ENOUGH CAPE TO BECOME CONVECTIVE IN NATURE. GIVEN THE BACKGROUND PRESSURE AND HEIGHT GRADIENTS IN THE THE LOWER LEVELS OF THE ATMOSPHERE THE HIGHER WINDS ALOFT SHOULD BE ABLE TO BE TAPPED BY THE CONVECTIVE CELLS LEADING TO GUSTY WINDS AT THE SFC. THIS COMBINED WITH THE SNOW SHOWERS WILL MEAN RAPIDLY CHANGING VISIBILITY IN GUSTY SNOW SQUALLS. FINALLY...GIVEN THE COLD STARTING POINT FOR ROAD SFCS... EXPECT ANY SNOW THAT FALLS TO POTENTIALLY ACCUMULATE ON THE ROADS...WITH LIMITED HELP FROM INSOLATION DURING THE DAYLIGHT HOURS. SO...ALTHOUGH QPF WILL BE RATHER LIMITED WITH THIS FRONT... THE IMPACT FROM THESE LIGHT EVENTS CAN BE AS LARGER OR LARGER THAN BIGGER WINTER STORMS SO WILL CONTINUE TO HIT IT HARD WITH A WSW ADVISORY ACROSS THE BULK OF OUR CWA TODAY...STARTING EARLIER IN THE WEST AND LINGERING LONGER IN THE EAST. SNOW AMOUNTS SHOULD BE MAXIMIZED...WITH A POTENTIAL FOR UP TO 2 INCHES...IN THE NORTHERN PARTS OF THE CWA AND IN THE HIGHEST TERRAIN NEAR THE VIRGINIA BORDER. THE SNOW WILL END FROM WEST TO EAST IN THE EVENING...WITH A DROP OFF IN THE SQUALLINESS AFTER SUNSET. LOOK FOR A HINT OF UPSLOPE COMPONENT INTO THE NIGHT TO KEEP A SMALL THREAT OF SNOW SHOWERS AND FLURRIES GOING IN THE FAR EAST THROUGH EARLY WEDNESDAY MORNING...BUT ANY ADDITIONAL ACCUMULATIONS WILL BE MARGINAL AFTER THIS EVENING. CHILLY HIGH PRESSURE THEN SPREADS INTO THE STATE WITH LOW TEMPERATURES NEARING THE SINGLE DIGITS IN THE NORTHWEST BY DAWN WEDNESDAY. WINDS STILL BRISK WILL YIELD WIND CHILLS DOWN NEAR ZERO IN SPOTS AND MAINLY SINGLE DIGITS ELSEWHERE AT DAWN WEDNESDAY. READING WILL THEN STRUGGLE TO RISE OUT OF THE 20S ON WEDNESDAY DESPITE A RETURN OF SOME SUNSHINE. IN FACT...THE SUNSHINE WILL LIKELY BE LIMITED BY SOME MID AND HIGH LEVEL CLOUDS INBOUND FROM THAT NEXT...WEAKER...WAVE PASSING BY AT MID LEVELS. ACCORDINGLY...HAVE NOT ZEROED OUT POPS FOR LATER WEDNESDAY AS A COUPLE OF FLURRIES CANNOT BE RULED OUT FROM THIS FEATURE WHEN IT BRUSHES BY FROM WEDNESDAY AFTERNOON INTO THE EVENING. USE THE SHORTBLEND AS A STARTING POINT FOR TEMPERATURES AND DEW POINTS THROUGH THE EVENING WITH THE SUPERBLEND USED THEREAFTER. MADE ONLY MINOR ADJUSTMENTS FOR SOME TERRAIN DISTINCTIONS TONIGHT...AS THE GRIDS LOOKED REASONABLE. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF THE MOS...WHICH IS TYPICAL FOR THIS TYPE OF SITUATION. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 AM EST TUE JAN 12 2016 PERIOD WILL BEGIN WITH A MID LEVEL TROUGH MOVING ACROSS THE OHIO VALLEY WEDNESDAY NIGHT...WHILE PRECIP WILL BE POSSIBLE NORTH OF THE REGION ACROSS CENTRAL OH. WE WILL MAINLY SEE CLOUDS ASSOCIATED WITH THIS WAVE WEDNESDAY NIGHT HERE IN EASTERN KY. ON THURSDAY HIGH WILL BE PARKED TO THE SE AND WILL INTRODUCE RETURN FLOW TO THE REGION. THIS WILL ALLOW TEMPS TO MODERATE THROUGH THE END OF THE WEEK. TEMPS ON THURSDAY WILL SOAR INTO THE UPPER 40S TO LOWER 50S...AND THIS WILL FEEL PLEASANT GIVEN ANTECEDENT TEMPS. OVERALL UPPER LEVEL FLOW WILL FLATTEN AHEAD OF A DEEPENING TROUGH ACROSS THE PLAINS. THIS AFOREMENTIONED DEEPENING TROUGH WILL SWING EAST AND NORTHEAST INTO THE TN/OH VALLEYS...AS IT NEGATIVELY TILTS. AT THE SURFACE...A SURFACE LOW WILL DEEPEN AND BRING A ROUND OF SHOWERS ACROSS MUCH OF EASTERN KY FRIDAY AFTERNOON INTO FRIDAY NIGHT. AFTER THIS THE UPPER LEVEL ENERGY WILL THEN BE FOCUSED ON ANOTHER SURFACE LOW THAT DEVELOPS AND DEEPENS ALONG THE MID ATLANTIC COAST. IN EASTERN KY WE WILL CONTINUE TO SEE WRAP AROUND MOISTURE WITH THIS SYSTEM. MUCH COOLER AIR WILL TRAIL THIS SYSTEM AND EVENTUALLY LEAD TO A RAIN/SNOW MIX IN PRECIP SATURDAY AND ALL SNOW BY SATURDAY NIGHT. THESE CHANCES OF SNOW WILL TAPPER OFF SUNDAY. AFTER THIS THE MODELS REALLY BEGIN TO DIVERGE. THE GFS BRINGS ANOTHER CLIPPER DOWN FOR MONDAY...WHILE THE ECMWF KEEPS REGION DRY. RIGHT NOW WILL LEAN TO THE BLEND WHICH BRING SLIGHT CHANCES FOR SNOW SHOWERS ACROSS MUCH OF THE REGION MONDAY. OVERALL WENT TOWARD MODEL BLEND THROUGH THE PERIOD FOR MOST ELEMENTS. DID KEEP OR MAKE MINOR ADJUSTMENTS GIVEN TRENDS AND USUAL TOPO TEMP ISSUES. GIVEN THE CONSISTENCY FOR THE FRIDAY AND SATURDAY SYSTEM RIGHT NOW WOULD EXPECT POPS THAT PERIOD WILL CONTINUE TO TREND HIGHER...AS WE GET CLOSER TO THE PERIOD IF THESE TRENDS REMAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 144 PM EST TUE JAN 12 2016 A LINE OF CONVECTIVE SNOW WILL PROGRESS SOUTHEAST ACROSS THE AREA THIS AFTERNOON...MARKING THE END OF SIGNIFICANT SNOW. THE SNOW MAY BE BRIEFLY INTENSE WITH VSBY LESS THAN A HALF MILE...AND ACCOMPANIED BY WESTERLY WIND GUSTS TOPPING 25 KTS. BEHIND THE CONVECTIVE SNOW BAND...VFR WILL RETURN FOR MOST LOCATIONS. HOWEVER...SOME MVFR CEILINGS MAY PERSIST AT TIMES TONIGHT IN FAR NORTHERN AND EASTERN PORTIONS OF THE AREA AROUND MOREHEAD TO PIKEVILLE. WINDS WILL DIMINISH THIS EVENING. VFR WITH LIGHT WINDS IS EXPECTED DURING THE DAY ON WEDNESDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044- 050>052-058>060-068-069-079-080-086>088-104-106>117-119. WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR KYZ118- 120. && $$ UPDATE...HAL SHORT TERM...GREIF LONG TERM...DJ AVIATION...HAL
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1126 AM CST TUE JAN 12 2016 .UPDATE... Updated aviation section for 18z taf issuance && .SHORT TERM...(Today through Thursday night) Issued at 244 AM CST TUE JAN 12 2016 Mid level energy will swing SE from IA/WI to the Ohio Valley this a.m. with an assoc sfc front. Will continue with the light snow possibility KEVV tri-state area. Only minor accumulations forecast, mainly dusting, to around 1/2" (especially north and east of KEVV) give or take. This activity will quickly depart early this a.m. followed by decreasing clouds. Quiet weather tonight through Thursday as high pressure moves across the area. Temperatures will moderate Wednesday through Thursday once return flow sets up. Still on track for showers to spread northeast across the area after midnight Thursday night. The 00z NAM is by far the fastest and most aggressive. We tempered that solution with the more consistent GFS/ECMWF solutions of the past couple of days. .LONG TERM...(Friday through Monday) Issued at 244 AM CST TUE JAN 12 2016 High confidence in rain event Friday. Low confidence after that period and low confidence in exact temperatures throughout the extended. The rain event for Friday looks to be on track as models locked on to this solution last week and remain steadfast. Also as previous discussion see some elevated instability with negative showalters and K index values around 30. There is also some hints of surface based instability with LI`s going negative with 100+ j/kg2 of CAPE. Nothing impressive but a clap of thunder cant be ruled out. This also is starting to be picked up with other offices. Friday night rain will slowly turn over to flurries after midnight with little impact/accumulation expected. Flurries may persist into Saturday but again confidence is low as is available moisture. After this point the models diverge significantly with ECMWF indicating a mostly dry extended and GFS not so much. Regardless of if it precipitates or not it again has very limited moisture therefore little to no impact expected. Models are coming in with nearly a 10 degree spread in the extended temperatures. The extended init took a middle of the road solution for temps and I opted to follow suit. Either way temperatures will again fall below normal for the extended. && .AVIATION... Issued at 1126 AM CST TUE JAN 12 2016 Skies cleared out very quickly this morning as the cold front moved through. Northwest winds gusted up to 30 knots immediately behind the front. Not much change is expected this afternoon. Wind gusts will be around 25 knots with mainly clear skies. There are some snow showers north of EVV in the Wabash Valley, but it appears they will slide just to the north and east of the airport this afternoon. Mainly clear skies and light winds are expected tonight as high pressure moves overhead. Winds will become southeast on Wednesday morning on the back side of the high. High clouds will increase, but cigs will be above 10k feet. && .PAH Watches/Warnings/Advisories... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ AVIATION...MY
Area Forecast Discussion National Weather Service Louisville KY 1210 PM EST TUE JAN 12 2016 ...Updated Aviation Discussion... ...Forecast Update... Updated at 1137 AM EST Tue Jan 12 2016 A line of snow squalls is currently crossing the region. These will drop visibilities very quickly to near zero with gusty winds up to 40 mph. They will be short lived and last only 15-20 minutes in any one location. However, they will create very hazardous driving conditions. Additional accumulations of a quick quarter to half an inch will be possible with these. Behind the current squall line, only light snow showers are expected before the front moves through. Temperatures have already begun to drop into the 20s across southern IN and will begin to do so shortly across central Kentucky. Have updated the grids to try and time the squall line through and then quickly taper off pops behind it. Also updated to bring things in line with current observations. Updated 838 AM EST Tue Jan 12 2016 The heavier band of snow continues to move across southern IN and has now crossed the river into north central KY. Have seen some reports of snow covered roads across portions of southern IN under the heavier snow band. Quick accumulations are expected as this moves through the Louisville metro and across north central KY. Thinking remains largely the same as far as snow totals. Most areas will see between 1-2 inches, but some isolated higher totals are not out of the question, especially as there is a some more showery areas of snow moving in behind this initial band. These will produce additional accums, but don`t look to be as widespread. The forecast was updated based on current radar trends. In addition, wind gusts in the grids were increased this afternoon. Have seen some gusts of 40-45 mph across central IL this morning along the front. Think we will see gusts of 35-40 mph frequently with some higher gusts not out of the question. .SHORT TERM (Now through Wednesday)... Issued at 225 AM EST Tue Jan 12 2016 ...Snow to Impact Travel This Morning Across Southern IN and Central KY... A vigorous weather system dropping out of the Upper Midwest will bring a 3-5 hour period of moderate snow showers to southern Indiana and northern Kentucky this morning. The light but quick accumulations will make for slick travel during the morning commute. The 2 am surface analysis showed a low pressure system over central Michigan while a warm front was passing through Indiana and western Ohio. A strong Arctic front is currently sweeping across Iowa and Wisconsin evident by a strong pressure fall/rise couplet, crashing temperatures, strong winds and a band of light to moderate snow. The Iowa/Wisconsin feature is what will track through southern Indiana and northern Kentucky later this morning. ===Timing=== HRRR and RAP have been the most consistent with its timing over the last several hourly runs, showing just a slight delay compared to our previous forecast. Expect this shield of snow showers to move into our southern/southwest Indiana counties between 7-8 am, then quickly drop into the Louisville metro and north-central Kentucky counties between 8-10am. Finally, it should sweep across the northern Bluegrass between 9-11am. Expect a 3-5 hour period of moderate snow showers at any given location in this zone. It will be showery, so intermittent breaks can be expected. By late afternoon, most areas will transition to flurries or an occasional snow shower but accumulating snow will be done by mid-afternoon. ===Accumulations=== No major changes to total snowfall forecast from previous shifts. Despite the limited moisture (QPF less than 0.1 of an inch), above normal snow ratios and a fair amount of the atmosphere within the DGZ will result in a quick 1 to 2 inches in the advisory area, especially along/north of the Ohio River. A localized 3 inch amount is still possible. ===Winds/Temps=== As the front crosses the region this morning, the strong pressure changes will result in 20 to 30 mph westerly winds. Expect some gusts to reach 35 mph at times from mid morning to early/mid afternoon. At the same time, temperatures will be falling throughout the day, especially north of the KY parkways. By mid afternoon, teens will be common along/north of I-64. Combined with the wind, plan on wind chill values in the teens to single digits. ===Impacts=== The quick hitting but moderate snow showers accumulating 1 to 2 inches will make for slick and hazardous travel conditions today. While the duration of the snow is expected to be only 3-5 hours, the rates while it is snowing will cause quick accumulations on roads and other surfaces, along with reductions in visibility and driving conditions. Road temperatures across the area range from 28 to 34F, so while treatment efforts will help, untreated surfaces and less traveled roads will become snow covered. The timing during the morning commute increases the impacts expected. The wind/falling temperatures will add a bite as well, especially by afternoon as wind chills fall down into the teens/single digits. As a result, no changes are planned for the winter weather advisory across the region. Tonight - Wednesday Expect a rapid clearing of clouds/lingering flurries by late afternoon or early evening (west to east) as cold Canadian high pressure builds overhead. The surface high should be right over central Kentucky by Wednesday morning, setting the stage for a very cold morning. It would be similar to yesterday (Monday) morning when lows ranged from +2 to +12. The fresh snowpack will help as well. For Wednesday, the high transitions to the east but the cold air mass lingering overhead will keep highs in the upper 20s to low 30s north of the KY parkways. Across south-central Kentucky, readings should reach the mid/upper 30s. .LONG TERM (Wednesday Night through Monday)... Issued at 225 AM EST Tue Jan 12 2016 The main forecast challenge in the long term period is a storm system Friday night into the weekend, followed by another round of unseasonably cold air. Wednesday Night - Friday This period will be characterized by high pressure settling over the southeast US with the upper level pattern mainly a dry northwest flow. A quick shortwave trough is expected to pass across the lower Great Lakes Wednesday night, but clouds/precip will stay well to the north. Expect a slow moderation in temperatures as well with highs rebounding into the 40s on Thursday and approaching the 50 degree mark on Friday. Friday Night - Saturday Night 01.12z guidance continued to advertise a storm system lifting out of the Gulf coast region toward the Great Lakes Friday night through Saturday, potentially continuing through Saturday night. The surface low track at this point stays just west of the area, which would favor a warmer (rain) solution for the area for the majority of the period. We`ll have to watch closely to see if falling temperatures behind the frontal passage early Saturday morning will meet up with remaining rain for a changeover to snow. After a warm Friday, expect a much colder Saturday with highs in the 30s. Sunday - Next Week Forecast guidance shows several shortwave troughs sweeping through in northwest flow aloft which look to bring reinforcing shots of colder air along with chances for snow showers. At this time, a model consensus points toward one on Sunday followed by another Monday night. Will keep slight chances of snow showers in the forecast with highs in the 30s and lows in the teens to low 20s. && .AVIATION (18Z TAF Update)... Updated at 1210 PM EST Tue Jan 12 2016 Surface cold front is pushing through the KSDF and KBWG terminals at this time. Winds will shift to the northwest and remain very strong this afternoon. Sustained winds of 17-22 knots and gusts up to 35kts will be possible into the late afternoon hours. A few snow flurries will be possible at KSDF and KBWG but the threat for widespread snow is over in this area. Skies will clear later this evening and winds will back to the 280-290 direction and decrease to 7-9kts by 13/00Z. Over at KLEX, a snow squall will impact the terminal shortly producing a brief period of IFR ceilings and visibilities. This should clear the terminal by 12/18Z and then scattered snow showers will be possible for the remainder of the afternoon along with VFR conditions. It will also be very windy at KLEX with sustained 18- 20kts and gusts of 35-37kts at times...diminishing by 13/00Z. && .LMK Watches/Warnings/Advisories... KY...Winter Weather Advisory until 4 PM EST /3 PM CST/ this afternoon for KYZ023>025-028>034-038-045-053. Winter Weather Advisory until 7 PM EST this evening for KYZ035>037-039>043-046>049-054>057-065>067. IN...Winter Weather Advisory until 4 PM EST /3 PM CST/ this afternoon for INZ076>079-083-084-089>092. && $$ Update.........EER Short Term.....ZT Long Term......ZT Aviation.......MJ
AREA FORECAST DISCUSSION
NWS GRAY ME
357 PM EST TUE JAN 12 2016 .SYNOPSIS... LOW PRESSURE MOVING ACROSS THE GULF OF MAINE TONIGHT WILL INTENSIFY AS IT MOVES NORTHEAST INTO THE MARITIMES ON WEDNESDAY. THIS WILL PRODUCE A ROUND OF SNOW TONIGHT...HEAVY AT TIMES ACROSS CENTRAL AND MIDCOAST MAINE. AS THE STORM EXITS IT WILL ALSO PRODUCE WINDY BUT FAIR CONDITIONS ON WEDNESDAY. HIGH PRESSURE BUILDS IN THURSDAY AND FRIDAY. ANOTHER ROUND OF SNOW...POSSIBLY RAIN NEAR THE COAST IS EXPECTED ON SATURDAY...WITH COLDER AIR MOVING IN SUNDAY AND MONDAY. && .NEAR TERM /TONIGHT/... A POTENT S/WV TROF IS CROSSING THE ERN GREAT LAKES AT THIS HOUR...AND WILL BRING SOME SIGNIFICANT IMPACTS TO THE AREA THIS EVENING AND TONIGHT. THE STRENGTH OF THIS S/WV IS EVIDENT IN THE WILD WX THIS AFTERNOON ACROSS UPSTATE NY. THUNDER HAS BEEN REPORTED AROUND BUF IN HEAVY SNWFL...WITH WIND GUSTS IN EXCESS OF 60 MPH. THESE SQUALLS MARK THE LEADING EDGE OF THE S/WV TROF. AHEAD OF IT...INCREASING SLY FLOW AND WAA IS ALLOWING LIGHT SNWFL TO BREAK OUT. THIS WILL INCREASE IN COVERAGE AND INTENSITY AS THE S/WV APPROACHES. THIS WILL LEAD TO MINOR ACCUMULATIONS THRU THE EVENING COMMUTE...BUT COULD LEAD TO SLIPPERY ROADS WITH TEMPS NEAR FREEZING. ATTENTION THEN TURNS TO THAT LEADING EDGE OF THE S/WV AND ATTENDANT SQUALLS. HI-RES MODEL GUIDANCE SUGGESTS IT BECOMES DIFFICULT TO DISTINGUISH BETWEEN THE LINE OF SN SHOWERS AND THE DEVELOPING STRONG INFLOW JET FORECAST TO FORM NEAR SERN NH. 12Z MODEL GUIDANCE SHIFTED THIS AREA OF FORMATION SLIGHTLY SW FROM 00Z MODEL SUITE. THIS BRINGS AREAS LIKE MHT AND ASH A LITTLE CLOSER TO THE BRIEF HEAVY SNWFL THREAT. HRRR GUIDANCE...ALONG WITH ARW...NMM...AND REGIONAL CMC ALL SHOW THE POTENTIAL FOR QPF...AND THUS SNWFL...TO BRIEFLY BE HEAVY AS THIS INFLOW JET SWEEPS NEWD THRU THE FORECAST AREA. SNWFL RATES MAY EXCEED 1 TO 3 INCHES PER HOUR IN THE HEAVIEST SNWFL...THOUGH MAY ONLY LAST FOR AN HOUR OR SO. MIXING ANY OF THAT WIND ALOFT DOWN IN HEAVY SHOWERS COULD ALSO BRING 30 TO 35 MPH GUSTS...WHICH WOULD LEAD TO NEAR ZERO VISIBILITY AT TIMES. I HAVE AN SPS IN EFFECT TO HIGHLIGHT THIS SHORT DURATION...HEAVY SNWFL ASPECT OF THE SYSTEM. IN ADDITION...LAPSE RATES ALOFT EXCEED 7 C/KM...SUFFICIENT FOR STRONG WARM SEASON CONVECTION LET ALONE WINTER. WILL KEEP THUNDER IN THE FORECAST FOR AREAS NEAR THE COAST WHERE THIS UNSTABLE AIR MASS IS ABLE TO MOVE IN OFF THE WATER. ANY CONVECTION WILL FURTHER ENHANCE THOSE SNWFL RATES. S/WV TROF CONTINUES NEGATIVE TILT THRU THE AREA...AND BAND OF SNWFL SHOULD BEGIN TO SLOW AND PIVOT AS IT APPROACHES CENTRAL ME. HEAVIEST AMOUNTS WILL BE IN OUR ERN ZONES...GENERALLY FROM AUG NEWD. AGAIN WILL HAVE TO MONITOR BOUNDARY LAYER TEMPS NEAR THE COAST...AS MODELS CONTINUE TO SUGGEST WARMING MAKING IT WELL INLAND. TEMPS ALOFT WOULD ARGUE THAT THIS STRUGGLES TO MAKE PROGRESS MUCH PAST THE NECKS AND ISLANDS. CAPE ELIZABETH AND MAYBE EVEN PWM MAY BE RA...WHILE THE TURNPIKE IS HEAVY SNWFL. HOWEVER TOO MUCH UNCERTAINTY EXISTS TO CHANGE HEADLINES FROM WHERE WE HAVE THEM CURRENTLY. SNWFL AMOUNTS LOOK VERY SIMILAR TO PREVIOUS SHIFT...MAYBE SLIGHTLY HIGHER OVER SWRN ME. HOWEVER THESE STILL FALL WITHIN ADVISORY RANGE. STILL A LOW CHANCE THAT SOME OF THE ADVISORY MAY NEED TO BE CONVERTED TO WARNINGS AS THE BANDING SETS UP. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... LOW PRES DEEPENS INTO THE 970S OVER THE CANADIAN MARITIMES WED...SETTING UP A STRONG PRES GRADIENT ACROSS THE AREA. FLOW IN CAA WILL BECOME GUSTY EARLY WED...INCREASING IN THE AFTERNOON AS THE CORE OF WLY JET AROUND 5000 FEET MOVES OVERHEAD. BUFKIT SOUNDINGS SHOW SOME POTENTIAL TO MIX DOWN SOME OF THIS JET...WITH A FEW MODELS SHOWING GUSTS IN THE 40 TO 45 KT RANGE. GIVEN THAT A WIND HEADLINE WOULD COMPLICATE AN ALREADY COMPLICATED FORECAST EVEN FURTHER...WILL HOLD OFF FOR NOW AND ALLOW THE MIDNIGHT SHIFT TO REASSESS. UPSLOPE SN SHOWERS WILL LINGER OVER THE NRN ZONES IN WLY FLOW WED. AN ADDITIONAL COUPLE OF INCHES IS POSSIBLE IN THE FAVORED AREAS. && .LONG TERM /THURSDAY THROUGH MONDAY/... HIGH IMPACT WX: LOW CONFIDENCE FOR SIGNIFICANT SNOW CENTERED AROUND SATURDAY. THE 500 MB PATTERN CONTINUES TO BUILD WEAK TO MODERATE RIDGING ACROSS THE WRN CONUS AND ERN PACIFIC...WITH A MEAN...BUT FLUCTUATING TROUGH OVER THE ERN CONUS. ALL IN ALL THOUGH...SO CALLED PINEAPPLE EXPRESS ACROSS THE PACIFIC WILL PROVIDE ENOUGH WAVES TO CONTINUALLY KNOCK DOWN THE RIDGE IN THE WEST...AND LACK OF COLD AIR OVER NOAM WILL LIMIT THERMAL ADVECTION ENOUGH IN THE ARCTIC TO MINIMIZE WAVE PRODUCTION TO MAINTAIN SOLID TROUGH OVER ERN CONUS. THIS...WILL SEE SOME CHANGEABLE CONDS THRU THE EXTENDED WITH TEMPS FLUCTUATING SEVERAL DEGREES EITHER SIDE OF NORMAL. SENSIBLE WX WILL SEE SFC RIDGE SLOWLY PASSING TO OUR S THU AND FRI...WITH SFC LOW MOVING NE INTO THE GREAT LAKES FRI NIGHT. 500MB WEAVE ROTATING AROUND THE BASE OF THE TROUGH WILL DEVELOP COASTAL BY SAT MORNING WHICH TRACKS OFF NEW ENGLAND COAST SAT. THIS WILL BE OUT NEXT PRECIP MAKER. MED RANGE MODELS IN BETTER AGREEMENT ON TIMING...WITH PRECIP STARTING SOMETIME FRI NIGHT AND ENDING SAT NIGHT. TRACK AND INTENSITY FORECASTS VARY QUITE A BIT...PARTICULARLY WHERE P-TYPE AND INTENSITY ARE CONCERNED WITH THE GFS MOVING THE LOW FURTHEREST OFFSHORE...WHILE THE GGEM IS THE CLOSEST...WITH THE EURO IN THE MIDDLE. SO WHILE SOME PRECIP CAN BE EXPECTED...AND IT WILL LIKELY BE SNOW INLAND...EVERYTHING ELSE STILL REMAINS LOW CONFIDENCE. UPPER LVL LOW CROSSES THE REGION SUNDAY WITH SHSN POSSIBLE...AND COLDER HIGH PRESSURE EXPECTED EARLY NEXT WEEK. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... SHORT TERM...IFR CONDITIONS ARE STEADILY PROGRESSING INTO THE AREA AS WAA INCREASES ALOFT. ONSHORE FLOW NEAR COASTAL ME WILL LEADING TO SOME OCEAN EFFECT AND OCEAN ENHANCED SNWFL...MAINLY AFFECTING PWM...AUG...AND RKD. IFR CONDITIONS AT LEB WILL EXPANDED EWD INTO HIE...CON...MHT...AND EVENTUALLY PSM IN THE NEXT FEW HOURS. CONFIDENCE IS LOW SO HAVE NOT INCLUDED IN THE TAFS...BUT A PERIOD OF 1 INCH PER HOUR SNWFL RATES IS POSSIBLE FROM NEAR PSM...NEWD THRU PWM...AUG...AND RKD. SLY WIND GUSTS OF 25 KTS MAY ACCOMPANY THIS SNWFL. MOST LIKELY THIS HAPPENS BETWEEN 00Z AND 05Z. SNWFL QUICKLY SWEEPS THRU THE AREA AND CONDITIONS IMPROVE FROM W TO E AFTER 06Z. UPSLOPE SHSN LINGER AT HIE...AND INTERMITTENT IFR CONDITIONS ARE POSSIBLE THERE. WLY WIND GUSTS OF 40 KTS ARE POSSIBLE WED IN STRONG CAA. LONG TERM...VFR WED NIGHT THROUGH FRI. FLIGHT RESTRICTIONS EXPECTED LATE FRI NIGHT INTO SAT EVE IN SN...OR POSSIBLE RA NEAR THE COAST. SOME IMPROVEMENT IS POSSIBLE ON SUN. && .MARINE... SHORT TERM...GALE WARNINGS REMAIN IN EFFECT FOR ALL WATERS THRU WED. WINDS MAY GUST TO NEAR STORM FORCE FOR A TIME IN STRONG CAA WED. LONG TERM...WINDS GRADUALLY DIMINISH FROM GALES WED EVE...TO SCA FOR THU....AND BELOW SCA THU NIGHT THRU FRI NIGHT. SCA OR GALES POSSIBLE AGAIN SAT AND SAT NIGHT. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR MEZ007- 012-019-020. WINTER STORM WARNING UNTIL 10 AM EST WEDNESDAY FOR MEZ008-009- 013-014-021-022-028. WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR MEZ018- 023-024. WINTER WEATHER ADVISORY UNTIL 10 AM EST WEDNESDAY FOR MEZ025>027. NH...WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR NHZ001>004-006. WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR NHZ008>010-012>014. MARINE...GALE WARNING FROM 7 PM THIS EVENING TO 11 PM EST WEDNESDAY FOR ANZ150>154. && $$ NEAR TERM...LEGRO SHORT TERM...LEGRO LONG TERM...CEMPA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 PM EST TUE JAN 12 2016 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 429 PM EST TUE JAN 12 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS CONTINUE A SHOW A TROF EXTENDING FROM HUDSON BAY INTO THE GREAT LAKES REGION. IN THE WAKE OF THE VIGOROUS SHORTWAVE THAT IS MOVING THRU THE LWR GREAT LAKES ATTM...DRIER AIR...SUBSIDENCE AND FALLING INVERSION HEIGHTS (NOW AROUND 5KFT W AND 7KFT E PER LATEST RAP) HAVE RESULTED IN SOME DIMINISHING OF LES TODAY...THOUGH SOME MDT SNOW SHOWERS CONTINUE. INVERSION HEIGHTS REMAIN RELATIVELY STEADY STATE TONIGHT...BUT THERE ARE SOME AREAS OF CONCERN AS WINDS SLOW BACK. FIRST...OVER THE NE FCST AREA...STRENGTHENING LAND BREEZES IN CONCERT WITH LARGER SCALE BACKING WINDS OVER UPPER MI WILL LEAD TO INCREASING LOW-LEVEL CONVERGENCE FROM ALGER COUNTY INTO NRN LUCE COUNTY. ALONG WITH THE LONG FETCH...EXPECT 3-5 INCHES OF SNOW IN GENERAL FROM AROUND GRAND MARAIS E ACROSS NRN LUCE COUNTY. SNOW WILL END IN WRN ALGER COUNTY TONIGHT AS BANDS SHIFT E UNDER BACKING WINDS. MOST OF THE LES SHOULD BE OFFSHORE BY SUNRISE...THOUGH SOME LES WILL BRUSH THE SHORELINE FROM GRAND MARAIS EASTWARD IN THE MORNING. ALGER COUNTY LES ADVY HAS BEEN EXTENDED TO 12Z WED WITH LUCE ADDED TO THAT. TO THE W...A TYPICAL CONVERGENCE PATTERN WILL DEVELOP AS BACKING WINDS AIDED BY LAND BREEZE RESULTS IN WSW WINDS DEVELOPING OVER THE SRN PART OF WRN LAKE SUPERIOR. MEANWHILE...WINDS REMAIN MORE WNW BTWN THE KEWEENAW AND ISLE ROYALE. END RESULT IS ENHANCED CONVERGENCE SETTING UP ACROSS THE MID PORTION OF WRN LAKE SUPERIOR...AIMED INTO THE FAR NRN PART OF ONTONAGON COUNTY AND INTO CNTRL HOUGHTON COUNTY...ROUGHLY BTWN TWIN LAKES AND PAINESDALE. HIGH RES MODEL GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO WITH ONLY SUBTLE DIFFERENCES IN PLACEMENT OF HEAVIEST QPF. CONVERGENCE BAND MAY SHIFT N SLIGHTLY DURING THE DAY WED AND AFFECT THE HOUGHTON AREA. LES WILL BE LIGHT THIS EVENING AS FLOW ADJUSTS OVER WRN LAKE SUPERIOR. LES SHOULD THEN INCREASE OVERNIGHT THRU WED IN THE AFORMENTIONED AREA AS THE CONVERGENCE ZONE SETS UP. THERE IS SOME INDICATION FOR A SLIGHT LIFTING OF THE INVERSION LATE TONIGHT/WED AND LIFTING OF THE DGZ TO ENCOMPASS MORE OF THE CONVECTIVE LAYER...ESPECIALLY WED. SO...GREATER SNOW ACCUMULATIONS WILL OCCUR DURING THE DAY WED. EXPECT GENERALLY 2-4 INCHES OF SNOW TONIGHT...THEN 3-7 INCHES OF SNOW WED. ADVY WILL ONLY BE CARRIED FOR NRN HOUGHTON COUNTY WHERE BEST SNOWFALL IS EXPECTED. IF IT LATER LOOKS LIKE MORE OF NRN ONTONAGON COUNTY MAY BE IMPACTED...ADVY WILL NEED TO BE EXPANDED. OTHER POTENTIAL CONCERN IS WIND CHILL HEADLINES IN THE COUNTIES ALONG THE MI/WI BORDER. WITH MIN TEMPS CURRENTLY EXPECTED AROUND -10F AND SUSTAINED WINDS LESS THAN 10 MPH...APPARENT TEMPS END UP JUST SHY OF THE -25F THRESHOLD FOR WIND CHILL ADVY. WILL BE SOMETHING TO MONITOR DURING THE EVENING IN THE EVENT TEMPS FALL MORE THAN EXPECTED AND/OR WINDS ARE A BIT STRONGER. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 429 PM EST TUE JAN 12 2016 WARMER AIR WILL BE MOVING IN STARTING WEDNESDAY NIGHT. NW FLOW AND AN ELONGATED SHORTWAVE WILL CONTINUE ALOFT WITH A 300MB JET AROUND 120KTS. THE FOCUS FOR ANY LINGERING MODERATE SNOW SHOWERS WILL BE OVER THE NW FAVORED WIND SNOW BELTS OF THE KEWEENAW PENINSULA. ELSEWHERE...MORE OF AN OFFSHORE OR PARALLEL SHORE FLOW IS ANTICIPATED OVER THE E. ANOTHER 1-2IN OF SNOW WILL BE POSSIBLE FROM THE PORCUPINE MTNS THROUGH THE TIP OF THE KEWEENAW...AND THEN RIGHT ALONG THE SHORELINE FROM GRAND MARAIS TO WHITEFISH POINT. THE 500MB LOW SPINNING OVER W HUDSON BAY WILL BEGIN TO SINK OVER N MANITOBA. AS A RESULT...LOOK FOR A MORE W FLOW TO TAKE HOLD OVER THE UPPER GREAT LAKES ON THURSDAY AS A TROUGH EXTENDS S FROM THE 500MB LOW ALL THE WAY THROUGH THE CENTRAL PLAINS AND DOWN TROUGH THE GULF OF MEXICO. SYNOPTIC SNOW/SNOW SHOWERS SHOULD WILL RETURN THURSDAY...AHEAD OF THE COMBINING N LOWS SINKING ACROSS THE N AND CENTRAL PLAINS. THERE HAS BEEN SOME DIFFERENCES ON THE TRACK OF THIS LOW OVER THE PAST 24 HOURS. YESTERDAY THEY SHOWED MORE OF A S TREND...LIKE THE 12Z SREF /OVER E KS/OK AT 06Z FRIDAY/. SINCE THEN THEY ARE A BIT MORE N INTO IA. EITHER WAY...A PERSISTANT NE-N SFC FLOW LOOKS TO SET IN ACROSS LAKE SUPERIOR AND UPPER MI FRIDAY AFTERNOON THROUGH SATURDAY EVENING AS THE SFC LOW EXITS ACROSS THE LOWER GREAT LAKES. THIS FEATURE LOOKS TO JOIN FORCES WITH ANOTHER LOW DEEPENING AS IT TRACKS UP THE E SEABOARD SATURDAY. THE RESULT WILL BE A STEADY TROUGH OVER OUR AREA WITH N-NW FLOW THROUGH TUESDAY AS A SFC HIGH OVER THE PLAINS SUNDAY NIGHT SLOWLY ATTEMPS TO BUILD IN OVER THE FIRST HALF OF THE WORK WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1227 PM EST TUE JAN 12 2016 MAIN LAKE EFFECT SNOW SHOWERS HAVE SHIFTED E OF KSAW. WHILE THERE MAY BE A FEW BRIEF -SHSN THAT REDUCE VIS TO MVFR...EXPECT ONLY SOME FLURRIES WITH VFR CONDITIONS THIS AFTN. AS WINDS CONTINUE TO BACK SLOWLY THRU THE FCST PERIOD...LAKE EFFECT SNOW SHOWERS WILL NOT AFFECT KSAW TONIGHT/WED MORNING...AND DEVELOPING DOWNSLOPE COMPONENT TO THE WIND SHOULD ENSURE VFR CONDITIONS CONTINUE TO PREVAIL. BACKING WINDS WILL ALSO SHIFT LAKE EFFECT SNOW SHOWERS OVER WRN UPPER MI. AT KIWD...THIS WILL RESULT IN -SHSN LIFTING N OF THE TERMINAL LATE THIS EVENING. UNTIL THEN...EXPECT IFR CONDITIONS TO GENERALLY BE THE RULE INTO THE EARLY EVENING WITH SOME PERIODS OF LIFR THRU MID AFTN. EXPECT IMPROVEMENT TO MVFR THIS EVENING THEN VFR OVERNIGHT FOR A TIME. AT KCMX...-SHSN WILL CONTINUE WITH A WIND TRAJECTORY OFF THE LAKE. EXPECT IFR CONDITIONS TO MOSTLY PREVAIL...BUT AS IS TYPICAL FOR LAKE EFFECT...CONDITIONS WILL BE VARIABLE WITH SOME MVFR AND LIFR AT TIMES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 404 PM EST TUE JAN 12 2016 WINDS WILL RELAX TONIGHT...AND REMAIN UNDER 25KTS THROUGH THROUGH THURSDAY NIGHT /DOWN TO LESS THAN 15KTS FOR MUCH OF LAKE SUPERIOR LATE WEDNESDAY NIGHT THROUGH THURSDAY/. HOWEVER...THERE COULD STILL BE SOME HEAVY FREEZING SPRAY OVER THE E HALF OF LAKE SUPERIOR EARLY THIS EVENING. LOW PRESSURE ALONG THE S ONTARIO AND QUEBEC BORDER WILL EXIT NE OF MAINE OVERNIGHT. A TROUGH WILL LINGER OVER LAKE SUPERIOR AS A RIDGE ACROSS MINNESOTA THIS EVENING SLIDES ACROSS WI OVERNIGHT...AND THEN TO THE SE STATES WEDNESDAY. EXPECT THE TROUGH OVER LAKE SUPERIOR TO DEEPEN WEDNESDAY INTO THURSDAY. TWO AREAS OF LOW PRESSURE OVER N MANITOBA AND THE DAKOTAS THURSDAY MORNING ARE EXPECTED TO COMBINE AND SHIFT ACROSS THE CENTRAL PLAINS THURSDAY NIGHT-FRIDAY. NE GUSTS OF 25-30KTS WILL RETURN FRIDAY AFTERNOON...AND LINGER THROUGH MUCH OF THE PERIOD WHILE TURNING MORE OUT OF THE N-NNW /ESPECIALLY OVER THE E HALF OF LAKE SUPERIOR/. THE LOW WILL LIFT NE ACROSS LOWER MI FRIDAY NIGHT AND EXIT ACROSS N NY SATURDAY NIGHT AS A STRONGER LOW RIDES UP THE E SEABOARD. LOOK FOR THE LINGERING RIDGE TO WEAKEN ACROSS LAKE SUPERIOR AS A HIGH PRESSURE SYSTEM MOVES FROM CANADA TO THE N AND CENTRAL PLAINS SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST WEDNESDAY FOR MIZ003. LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ006- 007. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ249>251-266-267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...ROLFSON MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EST TUE JAN 12 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EST TUE JAN 12 2016 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UPR TROF DOMINATING THE E HALF OF NAMERICA DOWNSTREAM OF HI AMPLITUDE RDG OVER THE W. POTENT SHRTWV DIGGING SEWD THRU THE TROF IS DIGGING SEWD THRU THE UPR MIDWEST...BRINGING 12HR H5 HGT FALLS TO ARND 100M AT INL AND MPX. ALTHOUGH THE SHRTWV ITSELF IS PASSING FAIRLY FAR TO THE S...DEEP LYR QVECTOR CNVGC AS WELL DEEP MOISTENING SHOWN ON THE 00Z INL RAOB ARE IMPACTING UPR MI...BRINGING SOME -SN TO MUCH OF THE CWA DESPITE LACK OF MSTR INFLOW/VERY DRY LLVLS SHOWN ON THE 00Z GRB RAOB. LLVL WINDS/SFC OBS ALSO INDICATE A SHARP LK INDUCED TROF IS IN THE PROCESS OF MOVING ONSHORE EARLY THIS MRNG AS THE LLVL WINDS VEER TO THE NNW FOLLOWING SHRTWV PASSAGE TO THE S. THE WSHFT/TROF PASSAGE AT CMX AND IWD WAS ACCOMPANIED BY SOME HEAVY SN SHOWERS. MQT RADAR IS ALSO SHOWING SOME MORE SGNFT RETURNS OVER SCENTRAL LK SUP EARLY THIS MRNG. TO THE N...THE 00Z H85 TEMP AT PICKLE LAKE ONTARIO WAS -30C...BUT THE NEAR SFC LYR THERE IS RATHER DRY. SKIES ARE MOCLR OVER MOST OF NRN MN/ADJOINING NW ONTARIO...WITH SFC DEWPTS NEAR -20F. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMNTS ASSOCIATED WITH THE SHRTWV/LK INDUCED TROF AND THEN LES TRENDS FOLLOWING THE PASSAGE OF THE SHRTWV/INFLUX OF COLDER AND DRIER AIR. TODAY...AS THE DIGGING SHRTWV EXITS TO THE SE...LLVL WINDS ARE FCST TO SHIFT TO THE NNW EARLY THIS MRNG...DRIVING THE LK INDUCED TROF STILL OVERL K SUP EARLY THIS MRNG. THE TROF IS EXPECTED TO BE THRU THE WRN ZNS BY FCST ISSUANCE...MARQUETTE ARND 12Z AND THEN NEWBERRY ARND 15Z. HIER RES RAP MODEL FCST SNDGS FOR SEVERAL LOCATIONS NEAR LK SUP SHOW A VERY SHARP AXIS OF ENHANCED LLVL UVV CENTERED WITHIN THE DGZ IN THE 1-4K FT AGL LYR...SO STILL EXPECT A BURST OF HEAVER SN WHEN THIS TROF COMES ONSHORE. HIER RES MODELS HINT AT 0.10-0.20 INCH OF WATER EQUIVALENT PCPN IN THE 6HR PERIOD CENTERED ARND THE TROF PASSAGE...WHICH WOULD SUPPORT AS MUCH AS 3-4 INCHES OF SN GIVEN THE FAVORABLE SN/WATER RATIOS. FARTHER INLAND...THE TROF/LLVL CNVGC ARE FCST TO WASH OUT...SO THE HEAVIER SN SHOWERS SHOULD OCCUR ONLY NEAR THE LK SUP SHORE. SHARP WSHFT OFF THE LK WITH LLVL MIXED LYR WINDS UP TO 30 KTS WL ALSO RESULT IN SOME BLSN/REDUCED VSBYS. GOING ADVYS IN THE LK SHORE COUNTIES SEEM APPROPRIATE. FOLLOWING THE TROF PASSAGE...DVLPG LARGER SCALE QVECTOR DVGC/ SUBSIDENCE ABOVE LLVL COLD SURGE THAT WL DROP H85 TEMPS TO AS LO AS -24C WL RESULT IN THE MORE TYPICAL WIND PARALLEL PURE LES BANDS. ASSOCIATED MID LVL DRYING/SUBSIDENCE INVRN BASE LOWERING TO 4-5K FT AGL AND IMPACT OF LLVL DRY AIR NOTED FARTHER UPSTREAM WL TEND TO LIMIT THE PURE LES ACCUMS AS WILL SHIFTING BANDS RELATED TO EXPECTED STEADILY BACKING WINDS TO THE WNW BY LATER IN THE DAY. WITH THE INFLUX OF VERY COLD AIR...MAX TEMPS WL RUN WELL BLO NORMAL AND NOT RISE ABOVE 5 TO 10F OVER THE W. TNGT...MODELS INDICATE ANOTHER SHRTWV SLIDING SEWD IN THE NW FLOW ALOFT WL MOVE INTO THE AREA TNGT...WITH AREA OF DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF THIS FEATURE RESULTING IN DEEPENING MSTR/SOME RISE IN INVRN BASE. THE LLVL WINDS ARE FCST TO BACK TO ABOUT 270-280 DEGREES BY 12Z WED...SO NRN ONTONAGON COUNTY/HOUGHTON COUNTIES AND AREAS NEAR LK SUP FM GRAND MARAIS TO WHITEFISH POINT LOOK TO BE THE FOCUS FOR THE HEAVIER SN SHOWERS. ENHANCED LAND BREEZE CNVGC RELATED TO THE VERY COLD AIR THAT WL DROP MIN TEMPS AT LEAST CLOSE TO -10F IN THE UNMODIFIED AIR NEAR THE WI BORDER WL SHARPER THE LLVL CNVGC AND THE SRN EDGE OF THE HEAVIER SN SHOWERS. SINCE NAM FCST SDNGS FOR CMX SHOW INCRSG UVV WITHIN THE DGZ TOWARD 12Z WED...NOT OUT OF THE QUESTION SOME ADVY LES WL OCCUR IN THESE FAVORED AREAS. ALTHOUGH WINDS ARE NOT LIKELY TO STAY UP NEAR THE WIND CHILL ADVY THRESHOLD OF 10 MPH OVER THE INTERIOR COLD SPOTS NEAR THE BORDER...APRNT TEMPS ARE LIKELY TO FALL AS LO AS -20 TO -25F. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 309 AM EST TUE JAN 12 2016 THE UPPER GREAT LAKES WILL STILL BE UNDER THE INFLUENCE OF THE ARCTIC AIR MASS AT THE START OF THE LONG TERM FORECAST...WITH LAKE EFFECT SNOW ONGOING IN THE WESTERLY WIND SNOW-BELTS. STILL EXPECT LIGHT TO MODERATE LAKE EFFECT TO BE OCCURRING OVER THE WEST AND KEWEENAW PENINSULA WEDNESDAY MORNING WITH INVERSION HEIGHTS AROUND 6KFT AND SOME INCREASED LOW LEVEL CONVERGENCES DUE TO THE HIGH PRESSURE RIDGE SLIDING TO THE SOUTH OF THE AREA AIDING LOW LEVEL BACKING FLOW OVER THE FAR WESTERN U.P.. SINCE THE LOWERING INVERSION WILL START TO KEEP MORE OF THE CLOUD LAYER WITHIN THE DGZ...SHOULD START TO SEE RATIOS COME UP AND WOULD THINK THERE WILL BE AN AREA OF ADVISORY SNOWFALL WITHIN THE DOMINATE BAND SETUP OVER NORTHERN ONTONAGON AND NORTHERN HOUGHTON COUNTIES AND SOMEWHERE BETWEEN SOUTH RANGE AND GREENLAND. THIS BAND SHOULD LIFT NORTH THROUGH THE AFTERNOON AND BE CENTERED AROUND OR TO THE NORTH OF HOUGHTON. AS TEMPERATURES ALOFT MODERATE THROUGH THE AFTERNOON/NIGHT (850MB TEMPS RISE TO -17C)...EXPECT ALL OF THE CLOUD TO FALL WITHIN THE DGZ WHICH WILL LEAD TO VERY FLUFFY SNOW AND HIGH RATIOS THROUGH WEDNESDAY NIGHT. WILL TREND POPS/RATIOS/SNOWFALL UP WITH THE FAVORABLE CONDITIONS FOR THE KEWEENAW WEDNESDAY AFTERNOON AND NIGHT BEFORE WARMING ALOFT (ASSOCIATED WITH THE APPROACHING SURFACE TROUGH AHEAD OF THE PLAINS LOW) QUICKLY BRINGS AN END TO THE LES ON THURSDAY MORNING. OVER THE EAST...THE WEST TO EVENTUALLY WEST-SOUTHWEST WINDS WILL KEEP THE BANDS LARGELY OFFSHORE BUT DID INCLUDE SOME HIGHER POPS IN CASE THE BAND AFFECTS AREAS TO THE EAST OF GRAND MARAIS. ONE FINAL ITEM OF NOTE BEFORE GETTING INTO THE LOW DEVELOPING INTO THE PLAINS...SHOULD SEE A WEAK SHORTWAVE MOVING THROUGH WISCONSIN WEDNESDAY NIGHT AND COULD SEE A FEW LIGHT SNOW SHOWERS ALONG THE WISCONSIN BORDER THROUGH THE NIGHT. THE SECOND HALF OF THE LONG TERM FORECAST WILL BE FOCUSED ON THE SURFACE LOW DEVELOPING IN THE NORTHERN/CENTRAL PLAINS AS A SHORTWAVE CROSSES THE ROCKIES. AS IT DEVELOPS AND SLIDES SOUTHEAST INTO THE MID MISSISSIPPI VALLEY THURSDAY INTO THURSDAY NIGHT...IT WILL STRETCH A TROUGH EAST-NORTHERN INTO THE GREAT LAKES REGION. AT THIS POINT...MODELS ARE FAIRLY CONSISTENT ON THE SURFACE TROUGH BEING JUST TO THE SOUTH OF THE AREA AND STRETCHING EAST ACROSS SOUTHERN WISCONSIN AND LOWER MICHIGAN. BUT WITH WEAK MID LEVEL WARM AIR ADVECTION TO THE NORTH OF THE TROUGH...SHOULD SEE SOME LIGHT SNOW SHOWERS MOVING ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT. RIGHT NOW...LOOKING LIKE 1-3 INCHES OF SNOW FROM THURSDAY NIGHT INTO FRIDAY...WITH THE HIGHEST AMOUNTS WHERE THE LAKE ENHANCEMENT OCCURS. THAT POTENTIAL INCREASES THURSDAY NIGHT INTO FRIDAY AS THE TROUGH SLIDES EAST AND THE LOW BEGINS TO STRENGTHEN IN NORTHERN MISSOURI AS THE SHORTWAVE MERGES WITH A SOUTHERN STREAM WAVE. EXPECT THE LES TO OCCUR IN THE NORTHEASTERLY WIND AREAS...WITH THE BEST SNOW POTENTIAL OCCURRING IN THE UPSLOPE AREAS OF MARQUETTE COUNTY (ESPECIALLY THE HURON MOUNTAINS). WILL TREND POPS UP FOR THAT AREA...BUT WITH MUCH OF THE CLOUD HOVERING AROUND OR JUST BELOW -10C...DON/T EXPECT THE LAKE EFFECT/ENHANCEMENT TO GET TO OUT OF HAND. MODELS STILL STRUGGLING WITH THE EXTENDED PERIOD...ESPECIALLY THE THE EVOLUTION OF THE LOW COMING OUT OF THE CENTRAL MISSISSIPPI VALLEY. THE 00Z ECMWF HAS SHIFTED AWAY FROM THE PREVIOUS RUNS AND TOWARDS WHAT THE 11/00Z RUN OF THE GFS WAS SHOWING (TRACKING THE LOW FARTHER NORTHWEST THROUGH NORTHERN LOWER MICHIGAN DUE TO A MORE ELONGATED UPPER TROUGH). MEANWHILE...THE 00Z GEM/GFS TRACK THE LOW THROUGH SOUTHEASTERN LOWER MICHIGAN BUT THAT IS ENOUGH TO HAVE SOME LIGHT SNOWFALL OVER THE SOUTHEAST HALF OF THE CWA. AT THIS POINT...THINK CHANCE POPS IS THE WAY TO GO WITH LIKELIES OVER THE NORTH CENTRAL WITH LAKE ENHANCEMENT. ANOTHER SURGE OF ARCTIC AIR DROPS INTO THE AREA FOR THE SECOND HALF OF THE WEEKEND AND EARLY NEXT WEEK BUT IT LOOKS LIKE IT WON/T BE AS COLD OR LAST AS LONG AS THIS PAST ARCTIC AIR PERIOD. SHOULD STILL SEE LAKE EFFECT SNOW THOUGH AND WILL TREND POPS UP (TO LIKELY VALUES AT LEAST) FOR THE NORTH-NORTHWESTERLY WIND AREAS ON SUNDAY AND MONDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1227 PM EST TUE JAN 12 2016 MAIN LAKE EFFECT SNOW SHOWERS HAVE SHIFTED E OF KSAW. WHILE THERE MAY BE A FEW BRIEF -SHSN THAT REDUCE VIS TO MVFR...EXPECT ONLY SOME FLURRIES WITH VFR CONDITIONS THIS AFTN. AS WINDS CONTINUE TO BACK SLOWLY THRU THE FCST PERIOD...LAKE EFFECT SNOW SHOWERS WILL NOT AFFECT KSAW TONIGHT/WED MORNING...AND DEVELOPING DOWNSLOPE COMPONENT TO THE WIND SHOULD ENSURE VFR CONDITIONS CONTINUE TO PREVAIL. BACKING WINDS WILL ALSO SHIFT LAKE EFFECT SNOW SHOWERS OVER WRN UPPER MI. AT KIWD...THIS WILL RESULT IN -SHSN LIFTING N OF THE TERMINAL LATE THIS EVENING. UNTIL THEN...EXPECT IFR CONDITIONS TO GENERALLY BE THE RULE INTO THE EARLY EVENING WITH SOME PERIODS OF LIFR THRU MID AFTN. EXPECT IMPROVEMENT TO MVFR THIS EVENING THEN VFR OVERNIGHT FOR A TIME. AT KCMX...-SHSN WILL CONTINUE WITH A WIND TRAJECTORY OFF THE LAKE. EXPECT IFR CONDITIONS TO MOSTLY PREVAIL...BUT AS IS TYPICAL FOR LAKE EFFECT...CONDITIONS WILL BE VARIABLE WITH SOME MVFR AND LIFR AT TIMES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 404 PM EST TUE JAN 12 2016 WINDS WILL RELAX TONIGHT...AND REMAIN UNDER 25KTS THROUGH THROUGH THURSDAY NIGHT /DOWN TO LESS THAN 15KTS FOR MUCH OF LAKE SUPERIOR LATE WEDNESDAY NIGHT THROUGH THURSDAY/. HOWEVER...THERE COULD STILL BE SOME HEAVY FREEZING SPRAY OVER THE E HALF OF LAKE SUPERIOR EARLY THIS EVENING. LOW PRESSURE ALONG THE S ONTARIO AND QUEBEC BORDER WILL EXIT NE OF MAINE OVERNIGHT. A TROUGH WILL LINGER OVER LAKE SUPERIOR AS A RIDGE ACROSS MINNESOTA THIS EVENING SLIDES ACROSS WI OVERNIGHT...AND THEN TO THE SE STATES WEDNESDAY. EXPECT THE TROUGH OVER LAKE SUPERIOR TO DEEPEN WEDNESDAY INTO THURSDAY. TWO AREAS OF LOW PRESSURE OVER N MANITOBA AND THE DAKOTAS THURSDAY MORNING ARE EXPECTED TO COMBINE AND SHIFT ACROSS THE CENTRAL PLAINS THURSDAY NIGHT-FRIDAY. NE GUSTS OF 25-30KTS WILL RETURN FRIDAY AFTERNOON...AND LINGER THROUGH MUCH OF THE PERIOD WHILE TURNING MORE OUT OF THE N-NNW /ESPECIALLY OVER THE E HALF OF LAKE SUPERIOR/. THE LOW WILL LIFT NE ACROSS LOWER MI FRIDAY NIGHT AND EXIT ACROSS N NY SATURDAY NIGHT AS A STRONGER LOW RIDES UP THE E SEABOARD. LOOK FOR THE LINGERING RIDGE TO WEAKEN ACROSS LAKE SUPERIOR AS A HIGH PRESSURE SYSTEM MOVES FROM CANADA TO THE N AND CENTRAL PLAINS SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST WEDNESDAY FOR MIZ003. LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ006- 007. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ249>251-266-267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...ROLFSON MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1228 PM EST TUE JAN 12 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 411 AM EST TUE JAN 12 2016 00Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW UPR TROF DOMINATING THE E HALF OF NAMERICA DOWNSTREAM OF HI AMPLITUDE RDG OVER THE W. POTENT SHRTWV DIGGING SEWD THRU THE TROF IS DIGGING SEWD THRU THE UPR MIDWEST...BRINGING 12HR H5 HGT FALLS TO ARND 100M AT INL AND MPX. ALTHOUGH THE SHRTWV ITSELF IS PASSING FAIRLY FAR TO THE S...DEEP LYR QVECTOR CNVGC AS WELL DEEP MOISTENING SHOWN ON THE 00Z INL RAOB ARE IMPACTING UPR MI...BRINGING SOME -SN TO MUCH OF THE CWA DESPITE LACK OF MSTR INFLOW/VERY DRY LLVLS SHOWN ON THE 00Z GRB RAOB. LLVL WINDS/SFC OBS ALSO INDICATE A SHARP LK INDUCED TROF IS IN THE PROCESS OF MOVING ONSHORE EARLY THIS MRNG AS THE LLVL WINDS VEER TO THE NNW FOLLOWING SHRTWV PASSAGE TO THE S. THE WSHFT/TROF PASSAGE AT CMX AND IWD WAS ACCOMPANIED BY SOME HEAVY SN SHOWERS. MQT RADAR IS ALSO SHOWING SOME MORE SGNFT RETURNS OVER SCENTRAL LK SUP EARLY THIS MRNG. TO THE N...THE 00Z H85 TEMP AT PICKLE LAKE ONTARIO WAS -30C...BUT THE NEAR SFC LYR THERE IS RATHER DRY. SKIES ARE MOCLR OVER MOST OF NRN MN/ADJOINING NW ONTARIO...WITH SFC DEWPTS NEAR -20F. MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMNTS ASSOCIATED WITH THE SHRTWV/LK INDUCED TROF AND THEN LES TRENDS FOLLOWING THE PASSAGE OF THE SHRTWV/INFLUX OF COLDER AND DRIER AIR. TODAY...AS THE DIGGING SHRTWV EXITS TO THE SE...LLVL WINDS ARE FCST TO SHIFT TO THE NNW EARLY THIS MRNG...DRIVING THE LK INDUCED TROF STILL OVERL K SUP EARLY THIS MRNG. THE TROF IS EXPECTED TO BE THRU THE WRN ZNS BY FCST ISSUANCE...MARQUETTE ARND 12Z AND THEN NEWBERRY ARND 15Z. HIER RES RAP MODEL FCST SNDGS FOR SEVERAL LOCATIONS NEAR LK SUP SHOW A VERY SHARP AXIS OF ENHANCED LLVL UVV CENTERED WITHIN THE DGZ IN THE 1-4K FT AGL LYR...SO STILL EXPECT A BURST OF HEAVER SN WHEN THIS TROF COMES ONSHORE. HIER RES MODELS HINT AT 0.10-0.20 INCH OF WATER EQUIVALENT PCPN IN THE 6HR PERIOD CENTERED ARND THE TROF PASSAGE...WHICH WOULD SUPPORT AS MUCH AS 3-4 INCHES OF SN GIVEN THE FAVORABLE SN/WATER RATIOS. FARTHER INLAND...THE TROF/LLVL CNVGC ARE FCST TO WASH OUT...SO THE HEAVIER SN SHOWERS SHOULD OCCUR ONLY NEAR THE LK SUP SHORE. SHARP WSHFT OFF THE LK WITH LLVL MIXED LYR WINDS UP TO 30 KTS WL ALSO RESULT IN SOME BLSN/REDUCED VSBYS. GOING ADVYS IN THE LK SHORE COUNTIES SEEM APPROPRIATE. FOLLOWING THE TROF PASSAGE...DVLPG LARGER SCALE QVECTOR DVGC/ SUBSIDENCE ABOVE LLVL COLD SURGE THAT WL DROP H85 TEMPS TO AS LO AS -24C WL RESULT IN THE MORE TYPICAL WIND PARALLEL PURE LES BANDS. ASSOCIATED MID LVL DRYING/SUBSIDENCE INVRN BASE LOWERING TO 4-5K FT AGL AND IMPACT OF LLVL DRY AIR NOTED FARTHER UPSTREAM WL TEND TO LIMIT THE PURE LES ACCUMS AS WILL SHIFTING BANDS RELATED TO EXPECTED STEADILY BACKING WINDS TO THE WNW BY LATER IN THE DAY. WITH THE INFLUX OF VERY COLD AIR...MAX TEMPS WL RUN WELL BLO NORMAL AND NOT RISE ABOVE 5 TO 10F OVER THE W. TNGT...MODELS INDICATE ANOTHER SHRTWV SLIDING SEWD IN THE NW FLOW ALOFT WL MOVE INTO THE AREA TNGT...WITH AREA OF DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF THIS FEATURE RESULTING IN DEEPENING MSTR/SOME RISE IN INVRN BASE. THE LLVL WINDS ARE FCST TO BACK TO ABOUT 270-280 DEGREES BY 12Z WED...SO NRN ONTONAGON COUNTY/HOUGHTON COUNTIES AND AREAS NEAR LK SUP FM GRAND MARAIS TO WHITEFISH POINT LOOK TO BE THE FOCUS FOR THE HEAVIER SN SHOWERS. ENHANCED LAND BREEZE CNVGC RELATED TO THE VERY COLD AIR THAT WL DROP MIN TEMPS AT LEAST CLOSE TO -10F IN THE UNMODIFIED AIR NEAR THE WI BORDER WL SHARPER THE LLVL CNVGC AND THE SRN EDGE OF THE HEAVIER SN SHOWERS. SINCE NAM FCST SDNGS FOR CMX SHOW INCRSG UVV WITHIN THE DGZ TOWARD 12Z WED...NOT OUT OF THE QUESTION SOME ADVY LES WL OCCUR IN THESE FAVORED AREAS. ALTHOUGH WINDS ARE NOT LIKELY TO STAY UP NEAR THE WIND CHILL ADVY THRESHOLD OF 10 MPH OVER THE INTERIOR COLD SPOTS NEAR THE BORDER...APRNT TEMPS ARE LIKELY TO FALL AS LO AS -20 TO -25F. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 309 AM EST TUE JAN 12 2016 THE UPPER GREAT LAKES WILL STILL BE UNDER THE INFLUENCE OF THE ARCTIC AIR MASS AT THE START OF THE LONG TERM FORECAST...WITH LAKE EFFECT SNOW ONGOING IN THE WESTERLY WIND SNOW-BELTS. STILL EXPECT LIGHT TO MODERATE LAKE EFFECT TO BE OCCURRING OVER THE WEST AND KEWEENAW PENINSULA WEDNESDAY MORNING WITH INVERSION HEIGHTS AROUND 6KFT AND SOME INCREASED LOW LEVEL CONVERGENCES DUE TO THE HIGH PRESSURE RIDGE SLIDING TO THE SOUTH OF THE AREA AIDING LOW LEVEL BACKING FLOW OVER THE FAR WESTERN U.P.. SINCE THE LOWERING INVERSION WILL START TO KEEP MORE OF THE CLOUD LAYER WITHIN THE DGZ...SHOULD START TO SEE RATIOS COME UP AND WOULD THINK THERE WILL BE AN AREA OF ADVISORY SNOWFALL WITHIN THE DOMINATE BAND SETUP OVER NORTHERN ONTONAGON AND NORTHERN HOUGHTON COUNTIES AND SOMEWHERE BETWEEN SOUTH RANGE AND GREENLAND. THIS BAND SHOULD LIFT NORTH THROUGH THE AFTERNOON AND BE CENTERED AROUND OR TO THE NORTH OF HOUGHTON. AS TEMPERATURES ALOFT MODERATE THROUGH THE AFTERNOON/NIGHT (850MB TEMPS RISE TO -17C)...EXPECT ALL OF THE CLOUD TO FALL WITHIN THE DGZ WHICH WILL LEAD TO VERY FLUFFY SNOW AND HIGH RATIOS THROUGH WEDNESDAY NIGHT. WILL TREND POPS/RATIOS/SNOWFALL UP WITH THE FAVORABLE CONDITIONS FOR THE KEWEENAW WEDNESDAY AFTERNOON AND NIGHT BEFORE WARMING ALOFT (ASSOCIATED WITH THE APPROACHING SURFACE TROUGH AHEAD OF THE PLAINS LOW) QUICKLY BRINGS AN END TO THE LES ON THURSDAY MORNING. OVER THE EAST...THE WEST TO EVENTUALLY WEST-SOUTHWEST WINDS WILL KEEP THE BANDS LARGELY OFFSHORE BUT DID INCLUDE SOME HIGHER POPS IN CASE THE BAND AFFECTS AREAS TO THE EAST OF GRAND MARAIS. ONE FINAL ITEM OF NOTE BEFORE GETTING INTO THE LOW DEVELOPING INTO THE PLAINS...SHOULD SEE A WEAK SHORTWAVE MOVING THROUGH WISCONSIN WEDNESDAY NIGHT AND COULD SEE A FEW LIGHT SNOW SHOWERS ALONG THE WISCONSIN BORDER THROUGH THE NIGHT. THE SECOND HALF OF THE LONG TERM FORECAST WILL BE FOCUSED ON THE SURFACE LOW DEVELOPING IN THE NORTHERN/CENTRAL PLAINS AS A SHORTWAVE CROSSES THE ROCKIES. AS IT DEVELOPS AND SLIDES SOUTHEAST INTO THE MID MISSISSIPPI VALLEY THURSDAY INTO THURSDAY NIGHT...IT WILL STRETCH A TROUGH EAST-NORTHERN INTO THE GREAT LAKES REGION. AT THIS POINT...MODELS ARE FAIRLY CONSISTENT ON THE SURFACE TROUGH BEING JUST TO THE SOUTH OF THE AREA AND STRETCHING EAST ACROSS SOUTHERN WISCONSIN AND LOWER MICHIGAN. BUT WITH WEAK MID LEVEL WARM AIR ADVECTION TO THE NORTH OF THE TROUGH...SHOULD SEE SOME LIGHT SNOW SHOWERS MOVING ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT. RIGHT NOW...LOOKING LIKE 1-3 INCHES OF SNOW FROM THURSDAY NIGHT INTO FRIDAY...WITH THE HIGHEST AMOUNTS WHERE THE LAKE ENHANCEMENT OCCURS. THAT POTENTIAL INCREASES THURSDAY NIGHT INTO FRIDAY AS THE TROUGH SLIDES EAST AND THE LOW BEGINS TO STRENGTHEN IN NORTHERN MISSOURI AS THE SHORTWAVE MERGES WITH A SOUTHERN STREAM WAVE. EXPECT THE LES TO OCCUR IN THE NORTHEASTERLY WIND AREAS...WITH THE BEST SNOW POTENTIAL OCCURRING IN THE UPSLOPE AREAS OF MARQUETTE COUNTY (ESPECIALLY THE HURON MOUNTAINS). WILL TREND POPS UP FOR THAT AREA...BUT WITH MUCH OF THE CLOUD HOVERING AROUND OR JUST BELOW -10C...DON/T EXPECT THE LAKE EFFECT/ENHANCEMENT TO GET TO OUT OF HAND. MODELS STILL STRUGGLING WITH THE EXTENDED PERIOD...ESPECIALLY THE THE EVOLUTION OF THE LOW COMING OUT OF THE CENTRAL MISSISSIPPI VALLEY. THE 00Z ECMWF HAS SHIFTED AWAY FROM THE PREVIOUS RUNS AND TOWARDS WHAT THE 11/00Z RUN OF THE GFS WAS SHOWING (TRACKING THE LOW FARTHER NORTHWEST THROUGH NORTHERN LOWER MICHIGAN DUE TO A MORE ELONGATED UPPER TROUGH). MEANWHILE...THE 00Z GEM/GFS TRACK THE LOW THROUGH SOUTHEASTERN LOWER MICHIGAN BUT THAT IS ENOUGH TO HAVE SOME LIGHT SNOWFALL OVER THE SOUTHEAST HALF OF THE CWA. AT THIS POINT...THINK CHANCE POPS IS THE WAY TO GO WITH LIKELIES OVER THE NORTH CENTRAL WITH LAKE ENHANCEMENT. ANOTHER SURGE OF ARCTIC AIR DROPS INTO THE AREA FOR THE SECOND HALF OF THE WEEKEND AND EARLY NEXT WEEK BUT IT LOOKS LIKE IT WON/T BE AS COLD OR LAST AS LONG AS THIS PAST ARCTIC AIR PERIOD. SHOULD STILL SEE LAKE EFFECT SNOW THOUGH AND WILL TREND POPS UP (TO LIKELY VALUES AT LEAST) FOR THE NORTH-NORTHWESTERLY WIND AREAS ON SUNDAY AND MONDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1227 PM EST TUE JAN 12 2016 MAIN LAKE EFFECT SNOW SHOWERS HAVE SHIFTED E OF KSAW. WHILE THERE MAY BE A FEW BRIEF -SHSN THAT REDUCE VIS TO MVFR...EXPECT ONLY SOME FLURRIES WITH VFR CONDITIONS THIS AFTN. AS WINDS CONTINUE TO BACK SLOWLY THRU THE FCST PERIOD...LAKE EFFECT SNOW SHOWERS WILL NOT AFFECT KSAW TONIGHT/WED MORNING...AND DEVELOPING DOWNSLOPE COMPONENT TO THE WIND SHOULD ENSURE VFR CONDITIONS CONTINUE TO PREVAIL. BACKING WINDS WILL ALSO SHIFT LAKE EFFECT SNOW SHOWERS OVER WRN UPPER MI. AT KIWD...THIS WILL RESULT IN -SHSN LIFTING N OF THE TERMINAL LATE THIS EVENING. UNTIL THEN...EXPECT IFR CONDITIONS TO GENERALLY BE THE RULE INTO THE EARLY EVENING WITH SOME PERIODS OF LIFR THRU MID AFTN. EXPECT IMPROVEMENT TO MVFR THIS EVENING THEN VFR OVERNIGHT FOR A TIME. AT KCMX...-SHSN WILL CONTINUE WITH A WIND TRAJECTORY OFF THE LAKE. EXPECT IFR CONDITIONS TO MOSTLY PREVAIL...BUT AS IS TYPICAL FOR LAKE EFFECT...CONDITIONS WILL BE VARIABLE WITH SOME MVFR AND LIFR AT TIMES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 AM EST TUE JAN 12 2016 STRONG NNW WINDS TODAY WILL REACH 30 KTS UNDER A TIGHT PRES GRADIENT BETWEEN LO PRES TRACKING THRU THE LOWER GREAT LAKES AND CANADIAN HI PRES BUILDING INTO THE NORTHERN PLAINS. ALTHOUGH GALES ARE NOT EXPECTED...THERE COULD BE A FEW GALE GUSTS...AND THE INCOMING AIRMASS WILL BE SUFFICIENTLY COLD TO GENERATE HEAVY FREEZING SPRAY. THE WINDS WILL BACK MORE TO THE NW THIS AFTERNOON AND DIMINISH AS THE HI PRES RIDGE GETS CLOSER...SO THE HEAVY FREEZING SPRAY WILL END. RELATIVELY LIGHT WINDS UNDER 25 KTS WILL THEN DOMINATE LATE TONIGHT THRU THU NIGHT. BUT AS ANOTHER LO PRES MOVES NE THRU THE CENTRAL GREAT LAKES ON FRI/SAT...NE WINDS WILL INCREASE UP TO 30 KTS UNDER THE TIGHTER PRES GRADIENT BETWEEN THE LO AND COLD HI PRES IN WCENTRAL CANADA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR MIZ001>003-009. LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ005. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LSZ248>251-265-266. HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ241>244-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...ROLFSON MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1157 AM CST TUE JAN 12 2016 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST TUE JAN 12 2016 NORTHWEST FLOW HAS BROUGHT ARCTIC AIR TO THE NORTHLAND. MOSTLY CLEAR SKIES HAVE HELPED TEMPERATURES DROP TO THE SINGLE DIGITS AND TEENS BELOW ZERO EARLY THIS MORNING. THE EXCEPTION IS FOR AREAS OF NW WISCONSIN DOWNWIND OF THE NW FLOW OVER LAKE SUPERIOR...WHERE THE LAKE EFFECT CLOUD COVER IS HELPING TEMPERATURES STAY SEVERAL DEGREES WARMER. A DEEP LOW OVER THE CENTRAL GREAT LAKES WILL SHIFT EAST INTO SOUTHERN ONTARIO TODAY. A SUBTLE UPPER LEVEL TROUGH OVER NORTHERN ONTARIO WILL PASS THROUGH THE NORTHLAND THIS MORNING. THE NW FLOW OVER THE LAKE WILL CONTINUE TO PRODUCE LAKE EFFECT SNOW SHOWERS ACROSS DOWNWIND AREAS OF NW WISCONSIN THROUGH AT LEAST THIS MORNING...AND POSSIBLY WELL INTO THIS AFTERNOON BEFORE ENOUGH DRIER AIR MOVES INTO THE REGION TO TAPER OFF ANY SIGNIFICANT SNOW SHOWERS. THE GREATEST ADDITIONAL SNOWFALL WILL BE FOR AREAS OF NORTHERN IRON COUNTY NEAR THE MICHIGAN BORDER NEAR IRONWOOD...WHERE AN ADDITIONAL 2 TO 4 INCHES WILL FALL THROUGH TODAY. NORTHERN BAYFIELD PENINSULA COULD GET AN ADDITIONAL 1 TO 2 INCHES. LEANED ON THE HIGHER SIDE OF PCPN GUIDANCE...INCLUDING THE WRF NMM AND ARW...AND THE SREF. THE NW WINDS OF 5 TO 15 MPH AND VERY COLD TEMPERATURES WILL CONTINUE TO RESULT IN WIND CHILL VALUES OF 20 TO 35 BELOW ZERO EARLY THIS MORNING. CONDITIONS WILL GRADUALLY IMPROVE AFTER SUNRISE...WITH AFTERNOON VALUES OF ABOUT 10 TO 20 BELOW ZERO. SOME MODELS ARE EXAGGERATING THE CLOUD COVER THIS MORNING...NOTABLY THE GFS AND ECMWF. THE SATELLITE AND OBSERVATIONS INDICATE VERY LITTLE...IF ANY...CLOUD COVER...SAVE FOR AREAS DOWNWIND OF LAKE SUPERIOR. THE HRRR SEEMS TO BE PERFORMING THE BEST...FOLLOWED BY THE NAM12/RAP13/CANADIANREGIONAL. LEANED ON THOSE MODELS FOR CLOUD TRENDS THROUGH THE REST OF THE DAY. THERE WILL LIKELY BE SOME AFTERNOON CUMULUS...ESPECIALLY OVER NORTHERN MINNESOTA. LEANED ON THE WARMER SIDE OF GUIDANCE BECAUSE THE COLDER GUIDANCE...SUCH AS THE GFS...MAY BE COLDER BECAUSE OF THE EXAGGERATED CLOUD COVER. HIGHS SHOULD REACH A FEW DEGREES ABOVE ZERO ACROSS THE SOUTH...AND APPROACH ZERO ACROSS THE NORTH AND WEST. A SURFACE RIDGE OF HIGH PRESSURE WILL BE JUST TO THE WEST AND SOUTH OF THE NORTHLAND TONIGHT. THE WIND SPEEDS WILL BE LIGHTER TONIGHT. THE COMBINATION OF CLEAR SKIES AND LIGHT WINDS THIS EVENING WILL ALLOW TEMPERATURES TO DROP QUICKLY THIS EVENING...DESPITE INCREASING HIGH LEVEL CLOUD COVER MOVING IN FROM THE WEST LATER TONIGHT. LEANED ON THE COLDER SIDE OF GUIDANCE...SUCH AS THE CANADIAN REGIONAL...AND NAM AND GFS MOS. OVERNIGHT LOWS WILL LIKELY BE WELL INTO THE TEENS BELOW ZERO FOR MOST OF THE NORTHLAND...BUT A BIT WARMER NEAR LAKE SUPERIOR. WIDESPREAD WIND CHILL VALUES OF 20 TO 30 BELOW ZERO ARE LIKELY...AND THE DAY SHIFT WILL ADDRESS THE NEED FOR AN ADVISORY ONCE THE ADVISORY FOR THIS MORNING COMES TO AN END. THE INCREASING CLOUD COVER LATE TONIGHT WILL BE ASSOCIATED WITH AN APPROACHING SHORTWAVE AND SUBTLE WARM FRONT ON WEDNESDAY FROM THE WEST. MOST OF THE MODELS ARE INDICATING THIS WAVE WILL BRING VERY MINIMAL AMOUNTS OF PCPN TO THE SW AND SOUTHERN FORECAST AREA LATE WEDNESDAY MORNING AND THROUGH THE AFTERNOON. THE HIGH SNOW TO LIQUID RATIOS OF THE SNOWFALL WILL MAKE IT EASY FOR THIS SHORTWAVE TO PRODUCE A TENTH OR TWO OF AN INCH...DESPITE THE MINIMAL PCPN. NOT ONLY WILL WARMER AIR MOVE INTO THE REGION WEDNESDAY...BUT THE CLOUD COVER WILL HELP INSULATE THE NORTHLAND. TEMPERATURES SHOULD FINALLY REACH THE POSITIVE SINGLE DIGITS AND TEENS AFTER THE RECENT DAYS OF MUCH COLDER THAN NORMAL TEMPERATURES. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 345 AM CST TUE JAN 12 2016 WEDNESDAY NIGHT THROUGH THURSDAY EVENING A NEW SHORTWAVE IS EXPECTED TO SWEEP ACROSS THE AREA...INTERACTING WITH A STRONG BAROCLINIC ZONE WHICH EXTENDS FROM SOUTHERN SASKATCHEWAN SOUTHEAST ACROSS MINNESOTA TO LOWER MICHIGAN. THIS SHOULD BRING A PERIOD OF SNOW ACROSS THE FORECAST AREA MAINLY ON THURSDAY...MAINLY ALONG AND SOUTH OF THE HIGHWAY 2 CORRIDOR. MODELS ARE STILL STRUGGLING WITH THE TIMING AND TRACK OF THIS WAVE...AND WE MAY SEE SOME ADJUSTMENTS IN THE NEXT FEW FORECAST CYCLES BEFORE CONFIDENCE INCREASES. TEMPERATURES TO BE NEAR TO BELOW NORMAL THROUGH THIS PERIOD WITH THE CLOUD COVER KEEPING THINGS MODERATED DESPITE THE STRONG NORTHWEST FLOW. THE NEXT POTENTIAL FOR A STRONGER STORM SHOULD AFFECT THE MIDWEST FRIDAY THROUGH SATURDAY OR SUNDAY. MODELS ARE STILL SHOWING LARGE DIFFERENCES BETWEEN MODELS AND HAVE VERY LOW CONFIDENCE IN THIS PORTION OF THE FORECAST. THE DIFFERENCES ARE MAINLY IN THE STRENGTH AND POSITION OF THE UPPER TROUGH AXIS THAT MOVES THROUGH FRIDAY/FRIDAY NIGHT...AND THE ASSOCIATED SURFACE FEATURES WHICH RANGE FROM HAVING THE STRONG SURFACE LOW OVER MISSOURI TO LAKE MICHIGAN FRIDAY AT 18Z. VARIABILITY REMAINS HIGH IN THE ENSEMBLES AS WELL...AND WOULD EXPECT THIS TO CONTINUE UNTIL THE MIDDLE OF THE WEEK WHEN THE UPPER LEVEL SHORTWAVE FINALLY COMES ONTO THE WEST COAST TO BE SAMPLED BY THE UPPER AIR NETWORK. HAVE KEPT THE LOW CHANCE POPS GOING THROUGH THE PERIOD WITH LAKE EFFECT SNOWS INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE NEAR NORMAL TO START OUT...GETTING COLDER AGAIN LATER IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1156 AM CST TUE JAN 12 2016 PATCHES OF MVFR CIGS WILL MOVE THROUGH AS THE AFTERNOON WEARS ON...AND INTO THE FIRST PART OF THE EVENING. THEN...A SHORTWAVE WILL SLIDE SOUTHEAST ACROSS THE REGION LATER TONIGHT AND ON WEDNESDAY. THIS SYSTEM WILL BRING LIGHT SNOW BACK INTO THE REGION. MVFR CIGS AND VSBYS WILL BE THE RULE ON TUESDAY MORNING...AND THERE MAY BE SOME IFR CIGS/VSBYS AS WELL BY LATE MORNING. && .PRELIMINARY POINT TEMPS/POPS... DLH 1 -11 10 5 / 0 0 20 20 INL -2 -17 6 -4 / 0 0 10 10 BRD 3 -15 15 9 / 0 0 20 20 HYR 2 -15 10 7 / 0 0 30 20 ASX 4 -10 11 7 / 30 0 20 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR WIZ001>003-006>009. LAKE EFFECT SNOW ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR WIZ004. MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ010>012-018>021- 025-026-033>038. LS...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR LSZ121- 146>148. && $$ SHORT TERM...GROCHOCINSKI LONG TERM...LE AVIATION...DAP
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1133 AM CST TUE JAN 12 2016 .SYNOPSIS... ISSUED AT 333 AM CST TUE JAN 12 2016 H5 ANALYSIS FROM EARLIER THIS EVENING HAD A BROAD TROUGH OF LOW PRESSURE CENTERED ACROSS THE EASTERN HALF OF THE CONUS. LOW PRESSURE WAS LOCATED ACROSS HUDSON BAY...WITH A SECONDARY LOW OVER QUEBEC. FURTHER WEST...A RIDGE EXTENDED FROM THE DESERT SW...NWD INTO IDAHO...WESTERN MT...AND INTO BRITISH COLUMBIA AND THE YUKON. AT THE SURFACE...AN ARCTIC COLD FRONT EXTENDED ROUGHLY FROM WEST OF VALENTINE...TO JUST NORTHEAST OF BROKEN BOW. INVOF THE FRONT...LIGHT SNOW FELL EARLIER THIS EVENING AND FLURRIES CONTINUE ROUGHLY ALONG A LINE FROM VALENTINE TO NORTH OF BROKEN BOW. RADAR RETURNS OVER THE PAST COUPLE OF HRS HAVE SHOWN A DECREASE IN COVERAGE...AS WELL AS INTENSITY OF SNOWFALL. THIS IS SUPPORTED BY SFC OBS AT KVTN...WHICH HAD VISBYS OF AROUND 5SM AT MIDNIGHT...AND 7SM CURRENTLY. EVEN WITH THE ARCTIC FRONT DRAPED ACROSS THE NORTHEASTERN CWA...TEMPS WERE RELATIVELY MILD TONIGHT THANKS TO THE ABUNDANT CLOUD COVER ALONG THE FRONT. SOUTHWEST OF THE FRONT...UNDER CLEAR SKIES...READINGS WERE MILD AS WELL. TEMPERATURES AS OF 3 AM CST RANGED FROM THE TEENS OVER NORTH CENTRAL AND NORTHEASTERN PORTIONS OF THE FORECAST AREA...TO THE LOWER TO MID 20S OVER SOUTHWESTERN PORTIONS OF THE FORECAST AREA. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 333 AM CST TUE JAN 12 2016 TODAY AND TONIGHT...TEMPERATURES WILL BE THE MAIN FORECAST CHALLENGE OVER THE NEXT 24 HOURS. FOR THIS MORNING...BASED ON THE HRRR AND LATEST NAM12 SOLNS...MID LEVEL LIFT WILL COME TO AN END ACROSS THE CENTRAL CWA AROUND 12Z. CLOUDS WILL REMAIN...HOWEVER ANY APPRECIABLE THREAT FOR LIGHT SNOW/FLURRIES IS EXPECTED TO END BEFORE 12Z THIS MORNING. WILL LEAVE OUT MENTION OF THIS IN THE FCST...HOWEVER...WILL CONTINUE TO MONITOR THE SITUATION TOWARD DAY BREAK...AND MAY NEED TO HANDLE THIS WITH A NOW CAST OR TWO IF FLURRIES DO DECIDE TO PERSIST AFTER 12Z. FOR THE REMAINDER OF TODAY...THE FRONTAL BOUNDARY WILL LIFT NORTHEAST AS A WARM FRONT...BECOMING ORIENTED ACROSS THE FAR NORTHEASTERN CWA BY 21Z THIS AFTERNOON. HIGHS WILL VARY WIDELY TDY WITH THE FRONT ANCHORED OVER NERN PORTIONS OF THE CWA. HIGHS WILL RANGE FROM AROUND 20 IN THE FAR NORTHEASTERN CWA...TO THE LOWER 40S IN THE FAR SOUTHWEST. WITH RESPECT TO HIGHS TDY...FOLLOWED THE WARMER MAV GUIDANCE...AS IT HAS HAD A MUCH BETTER TRACK RECORD OF VERIFYING OVER THE PAST COUPLE OF DAYS. FOR TONIGHT...THE WARM FRONT WILL LIFT FURTHER NORTHEAST OF THE AREA. COMPARED TO THE LOWS ATTM IN THE 20S...CLEARING SKIES AND LIGHT WESTERLY WINDS...WILL LEAD TO LOWS TONIGHT IN THE TEENS...WHICH IS STILL 5 TO 10 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 333 AM CST TUE JAN 12 2016 MID RANGE...WEDNESDAY AND THURSDAY...500HPA RIDGE AXIS TO BEGIN THE PERIOD AND BREAKS DOWN BY THE END. MODELS SHOW STRONG WAA AT 850HPA ACROSS THE FORECAST AREA WEDNESDAY WITH 5 TO 7C AT 00Z THU...WHICH SHOULD BE ENHANCED BY DOWNSLOPING. ADJUSTED MAX TEMPS UP A DEGREE OR TWO...WHICH IS STILL UNDERCUTTING THE MAV AND ECM BY A FEW DEGREES. GIVEN MOSTLY CLEAR CONDITIONS AND WESTERLY 20 TO 30 KTS AT 850HPA...CURRENT FORECAST HIGHS ARE PROBABLY TOO COOL. COLD FRONT DROPS SOUTH ACROSS THE AREA THURSDAY AFTERNOON AND EVENING...BUT ENOUGH CLEARING AND MIXING EARLY IN THE DAY WILL ALLOW HIGHS IN THE 40S EAST OF THE PANHANDLE. BETTER MOISTURE PROFILES ARE THU NIGHT INTO FRIDAY...SO INCLUDED -SN AFTER 00Z UNTIL 12Z. SOME SATURATION MAY OCCUR EARLIER ACROSS NORTHWEST NEBRASKA...AND DEPENDING ON TEMPS...PRECIP MAY FALL AS RAIN. FRONTOGENESIS APPEARS STRONGEST ACROSS THE SANDHILLS...BUT THE WINDOW FOR SATURATION AND LIFT WITHIN THE DGZ IS RATHER SHORT...LIMITING QPF. LONG RANGE...FRIDAY THROUGH TUESDAY...IS CHARACTERIZED BY A SERIES OF WAVES AND COOLER TEMPERATURES. THE NEXT ROUND COMES IN LATE FRIDAY INTO EARLY SATURDAY. LOW LEVEL MOISTURE IS SUFFICIENT AS SIGNALED BY EXPANSIVE CLOUD COVER...BUT AGAIN THE WINDOW FOR LIFT AND FRONTOGENETICAL FORCING IS SMALL. THE MERDIONAL 250HPA JET ALSO PASSES THROUGH FAIRLY QUICKLY...NOT CONTRIBUTING MUCH UPPER LEVEL DIFFLUENCE DESPITE A 120KT JET STREAK. THE BEST CHANCE OF -SN IS GENERALLY WEST OF HIGHWAY 83 AND NOT EXPECTING MUCH PRECIPITATION. SATURDAY NIGHT THROUGH MONDAY...THE GFS AND ECM DIVERGE A BIT. THE ECM BRINGS A DISTURBANCE THROUGH EARLY SUNDAY WHILE THE GFS IS 24 HOURS LATER...THUS DELAYING THE STRONG CAA. 850HPA TEMPS ARE SIMILAR IN MAGNITUDE...AROUND -20C AT THE COOLEST POINT. DUE TO UNCERTAINTY IN THE TIMING...WENT MIDDLE OF THE ROAD FOR TEMPS AND HAVE SCHC -SN EARLY TO MID MONDAY ACROSS THE WEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1130 AM CST TUE JAN 12 2016 VFR CONDITIONS AT BOTH KVTN AND KLBF TERMINALS. BAND OF CLOUDS THAT WAS OVER VTN CONTINUE TO LIFT OFF TO THE NORTHEAST ACROSS NORTH CENTRAL NEBRASKA. SCATTERED MID/HIGH CLOUDS WILL MOVE BACK IN ACROSS NORTHERN NEBRASKA FROM SOUTH DAKOTA BUT WILL NOT IMPACT VFR CONDITIONS. WINDS WILL REMAIN LIGHT OUT OF THE WEST THROUGH THE REST OF THE DAY INTO THE OVERNIGHT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...SNIVELY AVIATION...GOMEZ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
318 PM CST TUE JAN 12 2016 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 245 PM CST TUE JAN 12 2016 LOW-END PRECIPITATION CHANCES AND A STARK TEMPERATURE CONTRAST FROM NORTH CENTRAL TO SOUTHWEST ND HIGHLIGHT THE SHORT TERM. LIGHT SNOW FROM NORTHWEST INTO SOUTH CENTRAL ND HAS BEEN ON A STEADY WEAKENING TREND SINCE ABOUT 19 UTC...AND IS EXPECTED TO DIMINISH FURTHER BY LATE AFTERNOON AS ASCENT DROPS OFF. WE ARE THEN CARRYING ANOTHER SLIGHT CHANCE OF LIGHT SNOW LATE TONIGHT FROM BOTTINEAU TOWARD RUGBY AND ROLLA OUT OF RESPECT TO A WEAK SHORTWAVE TROUGH IN NORTHWEST FLOW ALOFT THAT WILL CLIP THAT AREA AFTER 06 UTC. INTERESTINGLY...BOTH THE OPERATIONAL AND EXPERIMENTAL /ESRL-RUN/ HRRR FLAVORS HAVE BEEN SIMULATING DENSE FOG DEVELOPMENT ACROSS CENTRAL ND TONIGHT. THEY ARE ON THEIR OWN IN THIS EXPECTATION AS NEITHER THE 12 UTC NAM-NEST OR POINT-BASED MOS GUIDANCE /MAV OR MET OUTPUT/ SUGGEST THIS SCENARIO. CLOSER INSPECTION SHOWED THE HRRR SIMULATIONS DEVELOP THIS FOG OVER LAKE SAKAKAWEA AND THEN ADVECT IT DOWNSTREAM ON LIGHT WIND FIELDS. SKIN TEMPERATURES IN THE HRRR SIMULATIONS ARE ABOVE 40 F OVER LAKE SAKAKAWEA...WHICH MEANS THEY ARE ASSUMING MUCH MORE OPEN WATER EXISTS THAN DOES IN REALITY. THUS...WE BELIEVE THAT THE HRRR GUIDANCE IS LIKELY OVERZEALOUS WITH ITS EXPECTATION OF FOG AND LOW CLOUD FORMATION. ON WEDNESDAY...STRONGER MID-LEVEL WARM AIR ADVECTION WILL OCCUR AND PUSH 850-MB TEMPERATURES TO +2 TO +4 C SOUTH AND WEST OF THE MISSOURI RIVER BY AFTERNOON. THE RESULT WILL BE HIGHS ABOVE 32 F IN THOSE AREAS...CONTRASTED BY HIGHS ONLY IN THE TEENS F ACROSS ROLETTE COUNTY. THE LOW- TO MID-LEVEL WARM FRONTAL BOUNDARY THAT WILL SEPARATE THOSE AIR MASSES COULD SERVE AS A FOCUS FOR LIGHT PRECIPITATION BY LATE DAY AS ANOTHER SHORTWAVE TROUGH APPROACHES THE AREA. THE 12 UTC MULTI-MODEL CONSENSUS SUPPORTED POPS OF 20 TO 30 PERCENT OVER NORTHWEST ND BY LATE AFTERNOON...AND WE CHOSE TO CONTINUE WITH A SLIGHT CHANCE OF LIGHT FREEZING IN THE WATFORD CITY AND WILLISTON AREAS BASED ON EXPECTED TEMPERATURES ALOFT. WE KEPT THE FORECAST DRY OVER SOUTH CENTRAL ND GIVEN A DRY BOUNDARY LAYER...BUT THE 12 UTC NCEP WRF-ARW SIMULATED LIGHT PRECIPITATION INTO THE BISMARCK AREA BY VERY LATE AFTERNOON...WHICH REPRESENTS A VERY LOW-END...BUT NON-ZERO RISK OF LIGHT FREEZING RAIN. WE DID NOT INCLUDE THAT IN THE OFFICIAL FORECAST AT THIS POINT FOR THAT AREA THOUGH SINCE THE PROBABILITY OF OCCURRENCE IS VERY LOW. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 207 PM CST TUE JAN 12 2016 THE MAIN ISSUES IN THE LONG TERM ARE SNOW CHANCES FOR THE END OF THE WEEK AND DANGEROUS COLD THIS WEEKEND. A CLIPPER WILL APPROACH NORTH DAKOTA WEDNESDAY EVENING. PRECIPITATION IS EXPECTED TO FORM ACROSS A PERSISTENT BAROCLINIC ZONE BISECTING NORTH DAKOTA. THE 12 UTC MODELS ARE IN FAIRLY GOOD AGREEMENT IN SPREADING 1 TO 2 INCHES OF SNOW ACROSS NORTHERN NORTH DAKOTA...WITH THE HIGHEST AMOUNTS CONFINED TO THE TURTLE MOUNTAINS. LIGHT SNOW IS EXPECTED TO BEGIN ACROSS FAR NORTHWEST NORTH DAKOTA WEDNESDAY EVENING AND SPREAD SOUTHEAST THROUGH WEDNESDAY NIGHT INTO THURSDAY MORNING. THE BAROCLINIC ZONE WILL SHIFT FURTHER SOUTHWEST THURSDAY AND FRIDAY...AND THEREFORE SNOW CHANCES WILL ALSO SHIFT FROM NORTHERN NORTH DAKOTA TO SOUTHWEST NORTH DAKOTA. HOWEVER...WITH THESE QUICK MOVING WAVES ONLY LIGHT QPF AMOUNTS ARE EXPECTED...SO LITTLE TO NO IMPACTS ARE ANTICIPATED. ANOTHER DEEP GREAT LAKES TROUGH IS EXPECTED TO FORM BY THIS WEEKEND. THIS WILL ALLOW BITTERLY COLD ARCTIC AIR TO PUSH INTO NORTH DAKOTA. THERE IS SOME UNCERTAINTY AS TO EXACTLY WHEN THE SURFACE HIGH AND COLDEST AIR WILL SETTLE ACROSS NORTH DAKOTA. HOWEVER...IT APPEARS TEMPERATURES WELL BELOW ZERO ARE LIKELY...WITH WIND CHILLS POTENTIALLY REACHING THE 20S AND 30S BELOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 245 PM CST TUE JAN 12 2016 A WEAKENING BAND OF LIGHT SNOW FROM NEAR KISN TOWARD KBIS AT MID AFTERNOON WILL WEAKEN BY 00 UTC. WE EXPECT CEILINGS TO LIFT OVER MOST OF WESTERN AND CENTRAL ND TONIGHT...LEADING TO VFR WEATHER LATER TONIGHT INTO WEDNESDAY MORNING. THE EXCEPTION MAY BE ACROSS A SMALL PART OF NORTH CENTRAL ND WHERE LIGHT SNOW WITH SUB-VFR CONDITIONS MAY OCCUR BETWEEN 06 AND 15 UTC. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CJS LONG TERM...AJ AVIATION...CJS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
227 PM PST TUE JAN 12 2016 .SYNOPSIS...A MUCH WETTER PATTERN WILL AFFECT SOUTHWEST WASHINGTON AND NORTHWEST OREGON FOR THE NEXT SEVERAL DAYS. WEATHER SYSTEMS WILL TRAVERSE THE REGION ABOUT EVERY 24 TO 36 HOURS. THE FIRST FRONT MOVES INLAND TONIGHT AND WEDNESDAY MORNING. SNOW LEVELS RISE ABOVE THE CASCADE PASSES TONIGHT...THEN FALL WEDNESDAY MORNING. THE NEXT SYSTEM IMPACTS THE REGION LATE THURSDAY AND THURSDAY NIGHT AND HAS THE POTENTIAL TO BRING SEVERAL INCHES OF SNOW TO THE CASCADES. ADDITIONAL FRONTS ARE EXPECTED OVER THE WEEKEND AND EARLY NEXT WEEK. && .SHORT TERM...TONIGHT THROUGH FRIDAY...WILL START WITH THE IMMEDIATE HIGHLIGHTS. 1) COASTAL WIND. HAVE OPTED TO GO WITH A HIGH WIND WARNING FOR THE OREGON COASTAL BEACHES AND HEADLANDS LATE THIS AFTERNOON THROUGH MIDNIGHT. MODELS SEEM TO BE HAVING SOME DIFFICULTY WITH THE DEVELOPING LOW PRES CENTER NEAR 41N 130W AT 21Z. NAM AND NAM-BASED VARIANTS HAVE BEEN WITH THE DEEPEST AND MOST CONSOLIDATED WITH THIS LOW. 12Z NAM DEEPENS IT TO AROUND 996 MB WEST OF KTMK BY 00Z WED. THE HRRR DEVELOPS A 1000 MB LOW NEAR BUOY 029 BY 01Z WED AND INDICATES 925 MB OF 55-65 KT ALONG THE BEACHES AND HEADLANDS. THE 4KM WRF-GFS IS CONSIDERABLY WEAKER WITH ITS 10M SUSTAINED WIND SPEEDS...ON THE ORDER OF 30-40 KT. THE PARALLEL GFS IS A LITTLE DEEPER WITH THE LOW COMPARED TO THE REGULAR VERSION. DO NOT EXPECT THE WIND SPEEDS TO PICK UP ALONG THE S COAST UNTIL LATE AFTERNOON. AT 22Z BUOY 015 NEAR PORT ORFORD HAD A GUST TO 56 MPH. IN ANY EVENT...WITH A FEW MODELS HINTING AT SOME FORM OF LOW DEVELOPMENT FEEL IT IS PRUDENT TO HAVE A WIND HIGHLIGHT FOR THE BEACHES AND HEADLANDS. 2) WINTER WEATHER. TEMPERATURES IN THE CENTRAL COLUMBIA GORGE HAVE MODERATED A BIT...INTO THE MID 30S AS OF 21Z. DECIDED TO END THE WINTER WEATHER ADVISORY IN THE CENTRAL GORGE. HOWEVER...IN THE UPPER HOOD RIVER VALLEY TEMPS ARE STILL NEAR 30 DEG. MOST REPORTS FROM AROUND THAT AREA SUGGEST MORE SNOW THAN FREEZING RAIN. THE OFFSHORE GRADIENT HAS ACTUALLY INCREASED SINCE THIS MORNING. AS OF 22Z THE KTTD-KDLS GRADIENT HAD INCREASED TO -8.6 MB. GETTING GUSTS CLOSE TO 80 MPH AT CROWN POINT AND 50-60 MPH AT CORBETT. DO NOT EXPECT THIS TO CHANGE UNTIL LATE EVENING. EXTENDED THE WINTER WEATHER ADVISORY IN THE UPPER HOOD VALLEY THROUGH 12Z WED. NAM SOUNDING FOR A POINT NEAR PARKDALE VALID 21Z IS PRETTY CLOSE TO REALITY. SOUNDING LOOKS MORE LIKE A SNOW SIGNATURE FOR THE NEXT FEW HOURS...THEN FAVORS FREEZING PRECIP AFTER 00Z WED. MODELS TEND TO WARM THE LOWER LAYERS TOO FAST. ALSO EXTENDED THE WINTER WEATHER ADVISORY FOR THE SOUTH WASHINGTON CASCADES THROUGH 12Z WED. AREAS AROUND TROUT LAKE ARE STILL AT OR JUST BELOW FREEZING AND DO NOT EXPECT MUCH CHANGE THERE DUE TO THE OFFSHORE FLOW. 3) QPF. INCOMING SYSTEM WILL BRING MUCH MORE QPF THAN THE PREVIOUS FEW. TOTAL BLENDED PRECIPITABLE WATER SHOWS 1.5 TO 1.75 INCHES OFF THE S OREGON COAST AND 1 TO 1.5 INCHES OFF THE NORTH AND CENTRAL COAST. 12Z GFS CONTINUES TO ADVERTISE 45-55 KT SW 850 MB WIND FLOW 00Z-06Z WED...WHICH WOULD RESULT IN SIGNIFICANT OROGRAPHIC CONTRIBUTION TO THE 6-HR QPF. INCREASED THE 00-06Z QPF...ESPECIALLY OVER THE OREGON COAST RANGE AND SW WA WILLAPA HILLS. 24-HR AMOUNTS THROUGH WED AFTERNOON LOOK TO BE ON THE ORDER OF AN INCH OR SO FOR THE INTERIOR VALLEYS AND UP TO 3 INCHES FOR THE OREGON COAST RANGE. NOT ANTICIPATING ANY HYDRO ISSUES WITH THE INCREASED QPF. SNOW LEVELS HAVE ALREADY RISEN ABOVE THE CASCADE PASSES EARLY THIS AFTERNOON. THE KTTD PROFILER INDICATES SNOW LEVELS NEAR 6000 FEET. GOVERNMENT CAMP WAS AROUND 35 DEG AND SANTIAM JCT...NEAR 4000 FEET...WAS AT 39 DEG. SNOW LEVELS FALL AGAIN WEDNESDAY AS THE UPPER TROUGH MOVES INLAND. THERE IS SOME POTENTIAL FOR LOW-END SNOW ADVISORY AMOUNTS IN THE CASCADES WED. GFS SHOWS ONE FINAL SHORT-WAVE TROUGH MOVING ACROSS THU EVENING. THERE WILL BE A SHORT BREAK OR DECREASE IN THE ACTION THU NIGHT AS THE NEXT DEVELOPING LOW TAKES SHAPE IN THE ERN PAC. OFFSHORE LOW-LEVEL RETURNS LATE THU AND AND THU EVENING. THIS WILL LIKELY DRIVE SNOW LEVELS LOWER THAN MODELS SUGGEST...ESPECIALLY FOR THE S WA CASCADES...UPPER HOOD RIVER VALLEY AND CENTRAL COLUMBIA GORGE. THIS SYSTEM MOVES INLAND LATE THU AND THU NIGHT...WITH THE BRUNT OF IT HEADING INTO SW OREGON. SNOW LEVELS TO REMAIN BELOW THE CASCADE PASSES WITH THIS SYSTEM WITH ADVISORY AMOUNTS HIGHLY LIKELY. BELIEVE THE SYSTEM MOVES THROUGH TOO QUICKLY FOR WARNING AMOUNTS. MODELS MAINTAIN SOME LINGERING PRECIP OVER MUCH OF THE FORECAST AREA FRI MORNING DESPITE DEVELOPING 500 MB RIDGING. THERE MAY BE A 6-12 HR DRY OR NEARLY-DRY PERIOD FRI AFTERNOON THROUGH FRI EVENING BEFORE OVER-RUNNING FROM THE NEXT SYSTEM ARRIVES. WEISHAAR .LONG TERM...THE WET AND PROGRESSIVE PATTERN CONTINUES THROUGH THE LONG TERM. GFS AND ECMWF SHOW ANOTHER SYSTEM MOVING THROUGH THE AREA SAT. SNOW LEVELS SHOULD REMAIN AT OR JUST BELOW THE CASCADE PASSES FOR ADDITIONAL ACCUMULATIONS. THIS SYSTEM DOES NOT LOOK QUITE AS WET AS ITS PREDECESSORS BUT COULD STILL PRODUCE SNOW ADVISORY AMOUNTS FOR THE CASCADES. MODELS SHOW MORE VARIANCE SUN WITH THE GFS SHOWING ANOTHER SYSTEM. IT STAYS FAIRLY CONSOLIDATED. THE ECMWF HAS STRONGER 500 MB RIDGING OVER THE AREA WITH WARM-FRONTAL OVER-RUNNING SPREADING ACROSS THE NRN ZONES SUN. MODELS MAINTAIN A FAIRLY PROGRESSIVE NATURE EARLY NEXT WEEK WITH 1000-500 MB THICKNESS VALUES HOVERING AROUND 540 DM...OR CLOSE TO THE CASCADE PASSES. WEISHAAR && .AVIATION...AN OCCLUDING FRONT WILL CONTINUE TO BRING RAIN TO THE FORECAST AREA TONIGHT UNDER MOIST SOUTHWESTERLY FLOW ALOFT. THIS WILL LEAD TO A MIX OF FLIGHT CONDITIONS THIS AFTERNOON AND EVENING...WITH PERIODS OF MVFR/IFR CIGS AND VSBY IN THE INTERIOR. CONDITIONS ALONG THE COAST LOOK TO REMAIN GENERALLY VFR THROUGH THIS EVENING. CIGS WILL LOWER TOWARDS MVFR ACROSS THE REGION LATER THIS EVENING WITH LITTLE CHANGE EXPECTED OVERNIGHT. SCATTERED SHOWERS EXPECTED WEDNESDAY. EAST WINDS WILL CONTINUE TO GUSTS TO 35 KT NEAR THE GORGE. AS THE LOW MOVES ONSHORE THIS EVENING THE COAST WILL SEE AN INCREASE IN SOUTHERLY WINDS...WITH GUSTS TO 45 KT POSSIBLE. KPDX AND APPROACHES...EXPECT MOSTLY VFR CIGS THIS AFTERNOON...WITH PERIODS OF MVFR CIGS AND VSBY UNDER RA. CIGS WILL LOWER TOWARDS MVFR LATER THIS EVENING...WITH LITTLE CHANGE EXPECTED OVERNIGHT. && .MARINE...AN OCCLUDED FRONT WILL CONTINUE TO MOVE ACROSS THE WATERS THIS AFTERNOON AND EVENING. A SHORTWAVE IS EXPECTED TO TRAVEL UP ALONG THE FRONT BRINGING STORM FORCE GUSTS TO THE CENTRAL OREGON WATERS. MODELS ALSO CONTINUE TO SUGGEST A COASTAL JET WILL DEVELOP THIS AFTERNOON AND MOVE UP THE COAST LATER THIS EVENING. HAVE SEE SOME EVIDENCE OF THIS WITH BUOY 15 CURRENTLY GUSTING TO 41 KT. A STORM WARNING REMAINS IN EFFECT FOR THE CENTRAL OREGON WATERS THROUGH THIS EVENING. THE STRONGEST WINDS LOOK TO REMAIN SOUTH OF CASCADE HEAD SO WILL KEEP THE GALE WARNING FOR THE NORTH OREGON AND SOUTH WASHINGTON WATERS. THE FRONT WILL PUSH ONSHORE LATER TONIGHT INTO WED MORNING...WITH WINDS FALLING QUICKLY BEHIND THE FRONT. RATHER BENIGN WINDS EXPECTED WED AS HIGH PRESSURE RETURNS BRIEFLY. ANOTHER FRONT WILL APPROACH THE WATERS ON THURSDAY AND MAY BRING A CHANCE OF GALES. THE ACTIVE WEATHER PATTERN LOOKS TO CONTINUE THROUGH THE WEEKEND WITH A CHANCE OF GALES ON SATURDAY. SEAS WILL CONTINUE TO FLUCTUATE BETWEEN 13 AND 15 FT...ALTHOUGH THEY MAY GET A LITTLE HIGHER OVER THE CENTRAL OREGON WATERS LATER THIS AFTERNOON AND EVENING DURING THE PERIOD OF STRONGEST WINDS. SEAS THEN SUBSIDE INTO THE LOW TEENS WEDNESDAY. A COUPLE OF STRONG LOWS MOVING ACROSS THE PACIFIC LATE IN THE WEEK WILL PRODUCE LARGER SEAS THIS WEEKEND...POSSIBLY EXCEEDING 20 FT. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR UPPER HOOD RIVER VALLEY. HIGH WIND WARNING UNTIL MIDNIGHT PST TONIGHT FOR CENTRAL OREGON COAST. HIGH WIND WARNING FROM 5 PM THIS AFTERNOON TO MIDNIGHT PST TONIGHT FOR NORTH OREGON COAST. WA...WINTER WEATHER ADVISORY UNTIL 6 AM PST WEDNESDAY FOR SOUTH WASHINGTON CASCADES. PZ...GALE WARNING UNTIL 9 PM PST THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. STORM WARNING UNTIL 9 PM PST THIS EVENING FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 3 PM PST WEDNESDAY. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
127 PM EST TUE JAN 12 2016 .SYNOPSIS... AN ACTIVE WINTER WEATHER PATTERN WILL GRIP CENTRAL PENNSYLVANIA THROUGH THE MIDWEEK PERIOD WITH FREQUENT SNOW SHOWERS AND LOCALIZED HEAVY SNOW SQUALLS...SIGNIFICANT LAKE EFFECT SNOW AND SUB-ZERO WIND CHILLS. ANOTHER STORM SYSTEM WILL IMPACT THE AREA INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... RADAR SHOWS THE BACK EDGE OF THE LEADING WAA SNOW APPROACHING THE ALLEGHENIES AS OF 17Z...WITH INITIAL FRONTAL SNSQ BAND ALONG FKL/BTP/PIT LINE. SNOW AMTS HAVE RANGED FROM T-0.5" OVER THE CENTRAL RIDGES TO 2+ INCHES OVER THE NW ALLEGHENIES/LAUREL HIGHLANDS. FOCUS WILL BE SHIFTING TO SNSQ/S THIS AFTERNOON. HRRR SEEMS TO HAVE A DECENT HANDLE ON THE CURRENT PLACEMENT AND FCST TIMING WHICH SEEMS TO BE FAVORING A SLIGHTLY LATER ARRIVAL BETWEEN 2-4 PM WEST ALONG RT219...4-6 PM CENTRAL NEAR I99-RT220 CORRIDOR AND 6-8 PM EAST ALONG RT15 FROM IPT-MDT AND POINTS EAST. THE BRIEFLY INTENSE AND LOCALIZED SNOW SQUALLS WILL BE HANDLED VIA SPECIAL WX STATEMENTS. MOTORISTS ARE URGED TO USE EXTREME CAUTION AND STAY UPDATED ON THE TIMING OF THE MOST INTENSE SQUALLS AND POOREST TRAVEL CONDITIONS. STRONG WINDS ARE EXPECTED BEHIND THE ARCTIC FRONT WITH PEAK GUSTS AROUND 40 MPH. A FEW GUSTS MAY APPROACH ADVISORY CRITERIA BUT ONLY FOR A LIMITED TIME. A TRANSITION TO PERSISTENT COLD FLOW OVER THE MAINLY ICE-FREE WATERS OF THE GLAKES WILL OCCUR BY THIS EVENING AND LAST THROUGH THE MIDDLE OF THE WEEK. HEAVY LAKE EFFECT SNOW ACCUMULATIONS ARE PROBABLE OVER THE NORTHWEST PA SNOWBELT WITH MAX 36-HOUR SNOWFALL TOTALS OF 6-10 INCHES ACROSS NW WARREN COUNTY - NORTH OF ROUTE 6. THE LAKE EFFECT SNOW WATCH FOR THE NW ZONES WILL TRANSITION TO AN ADVISORY OR WARNING AT SOME POINT LATER TODAY. SUB-ZERO WIND CHILLS ARE EXPECTED TONIGHT INTO EARLY WEDNESDAY MORNING OVER THE WESTERN MTNS WITH MINIMUM VALUES AS LOW AS -10F. WIND CHILLS WILL BE MAINLY IN THE 5 BELOW TO 5 ABOVE ZERO ELSEWHERE DURING THIS SAME PERIOD. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... MOST OF THE SIGNIFICANT LAKE EFFECT WILL BE OVER BY THE SECOND PART OF WED. IT WILL BE QUITE COLD THOUGH WITH MAX TEMPS ABOUT 10-12 DEG F BELOW NORMAL. MAXES WILL VARY FROM THE TEENS ACROSS THE WRN MTNS...TO BETWEEN 20 AND 25 F HEADING SE TWD THE LOWER SUSQ VALLEY. A WEAK CLIPPER MAY BRING A LITTLE LIGHT SNOW LATE WED NIGHT INTO EARLY THU...BUT WILL BE IMMEDIATELY FOLLOWED BY MODERATELY STRONG LOW TO MID-LEVEL WARM ADVECTION. && .LONG TERM /THURSDAY THROUGH MONDAY/... MODEL TRENDS IS TO HAVE SYSTEM LATE FRIDAY INTO SAT TRACK NW OF PA. THUS TEMPERATURES WOULD SUPPORT RAIN. TEMPERATURES BORDERLINE...THUS MENTION SNOW TOO. LATE SATURDAY NIGHT INTO SUNDAY...TEMPERATURES COOL BACK DOWN...AS ENERGY TRANSFERS TO COASTAL LOW. MAINLY DRY FOR NEXT MONDAY. DID NOT CHANGE MUCH ON THIS PACKAGE. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... LIGHT SNOW AND WINDY CONDITIONS HAVE BROUGHT DOWN VISIBILITIES AND CAUSED IFR CONDITIONS TODAY. IFR CONDITIONS WILL CONTINUE FOR ALL BUT THE SOUTHERN SUSQUEHANNA VALLEY THIS AFTERNOON. AN ARCTIC FRONT WILL PASS THROUGH THE STATE THIS AFTERNOON AND EVENING BRINGING DANGEROUS SNOW SQUALLS WITH IT. THE SNOW SQUALLS WILL BRING VISIBILITY DOWN TO 1/4 SM AND HAVE WIND GUSTS IN EXCESS OF 30 KTS BETWEEN 19Z AND 21Z. THE EXCEPTION FOR THIS AGAIN IS OVER THE SOUTHERN SUSQUEHANNA VALLEY WHERE CONDITIONS ARE NOT EXPECTED TO DROP AS SIGNIFICANTLY BUT WILL STILL BE IFR FOR AN HOUR OR SO AROUND 22Z. AFTER THE FRONT PASSES TONIGHT WINDS WILL CONTINUE TO GUST AROUND 20 KTS. SOME LINGERING SNOW SHOWERS OVER THE HIGHER TERRAIN OF THE APPALACHIANS WILL CONTINUE IFR RESTRICTIONS IN THESE LOCATIONS. VFR CONDITIONS WILL RETURN FOR ALL OVERNIGHT EXCEPT NORTHWEST PA...INCLUDING KBFD...AS A LAKE EFFECT SNOW EVENT WILL BEGIN...CAUSING IFR CONDITIONS TO RETURN. VFR CONDITIONS SHOULD RETURN TO NW PA LATER IN THE DAY TOMORROW AND WINDS WILL WANE FOR ALL. THURSDAY AND FRIDAY WILL BE TRANQUIL AND COLD WITH VFR CONDITIONS EXPECTED. A STORM SYSTEM WILL AFFECT THE AIRSPACE THIS WEEKEND AND MAY BE A MIX OF RAIN AND SNOW WITH RESTRICTIONS POSSIBLE. OUTLOOK... WED-FRI...CIG/VSBY REDUCTIONS LIKELY NW HALF IN SNOW SHOWERS. VFR ELSEWHERE. SAT...REDUCTIONS POSS WITH CHANCE FOR RAIN/SNOW. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY MORNING FOR PAZ004-005. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ004- 005. WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ006- 010-011-017-024-033. && $$ SYNOPSIS...STEINBUGL NEAR TERM...STEINBUGL SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...KEARNS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1205 PM EST TUE JAN 12 2016 .SYNOPSIS... AN ACTIVE WINTER WEATHER PATTERN WILL GRIP CENTRAL PENNSYLVANIA THROUGH THE MIDWEEK PERIOD WITH FREQUENT SNOW SHOWERS AND LOCALIZED HEAVY SNOW SQUALLS...SIGNIFICANT LAKE EFFECT SNOW AND SUB-ZERO WIND CHILLS. ANOTHER STORM SYSTEM WILL IMPACT THE AREA INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... RADAR SHOWS THE BACK EDGE OF THE LEADING WAA SNOW APPROACHING THE ALLEGHENIES AS OF 17Z...WITH INITIAL FRONTAL SNSQ BAND ALONG FKL/BTP/PIT LINE. SNOW AMTS HAVE RANGED FROM T-0.5" OVER THE CENTRAL RIDGES TO 2+ INCHES OVER THE NW ALLEGHENIES/LAUREL HIGHLANDS. FOCUS WILL BE SHIFTING TO SNSQ/S THIS AFTERNOON. HRRR SEEMS TO HAVE A DECENT HANDLE ON THE CURRENT PLACEMENT AND FCST TIMING WHICH SEEMS TO BE FAVORING A SLIGHTLY LATER ARRIVAL BETWEEN 2-4 PM WEST ALONG RT219...4-6 PM CENTRAL NEAR I99-RT220 CORRIDOR AND 6-8 PM EAST ALONG RT15 FROM IPT-MDT AND POINTS EAST. THE BRIEFLY INTENSE AND LOCALIZED SNOW SQUALLS WILL BE HANDLED VIA SPECIAL WX STATEMENTS. MOTORISTS ARE URGED TO USE EXTREME CAUTION AND STAY UPDATED ON THE TIMING OF THE MOST INTENSE SQUALLS AND POOREST TRAVEL CONDITIONS. STRONG WINDS ARE EXPECTED BEHIND THE ARCTIC FRONT WITH PEAK GUSTS AROUND 40 MPH. A FEW GUSTS MAY APPROACH ADVISORY CRITERIA BUT ONLY FOR A LIMITED TIME. A TRANSITION TO PERSISTENT COLD FLOW OVER THE MAINLY ICE-FREE WATERS OF THE GLAKES WILL OCCUR BY THIS EVENING AND LAST THROUGH THE MIDDLE OF THE WEEK. HEAVY LAKE EFFECT SNOW ACCUMULATIONS ARE PROBABLE OVER THE NORTHWEST PA SNOWBELT WITH MAX 36-HOUR SNOWFALL TOTALS OF 6-10 INCHES ACROSS NW WARREN COUNTY - NORTH OF ROUTE 6. THE LAKE EFFECT SNOW WATCH FOR THE NW ZONES WILL TRANSITION TO AN ADVISORY OR WARNING AT SOME POINT LATER TODAY. SUB-ZERO WIND CHILLS ARE EXPECTED TONIGHT INTO EARLY WEDNESDAY MORNING OVER THE WESTERN MTNS WITH MINIMUM VALUES AS LOW AS -10F. WIND CHILLS WILL BE MAINLY IN THE 5 BELOW TO 5 ABOVE ZERO ELSEWHERE DURING THIS SAME PERIOD. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... MOST OF THE SIGNIFICANT LAKE EFFECT WILL BE OVER BY THE SECOND PART OF WED. IT WILL BE QUITE COLD THOUGH WITH MAX TEMPS ABOUT 10-12 DEG F BELOW NORMAL. MAXES WILL VARY FROM THE TEENS ACROSS THE WRN MTNS...TO BETWEEN 20 AND 25 F HEADING SE TWD THE LOWER SUSQ VALLEY. A WEAK CLIPPER MAY BRING A LITTLE LIGHT SNOW LATE WED NIGHT INTO EARLY THU...BUT WILL BE IMMEDIATELY FOLLOWED BY MODERATELY STRONG LOW TO MID-LEVEL WARM ADVECTION. && .LONG TERM /THURSDAY THROUGH MONDAY/... MODEL TRENDS IS TO HAVE SYSTEM LATE FRIDAY INTO SAT TRACK NW OF PA. THUS TEMPERATURES WOULD SUPPORT RAIN. TEMPERATURES BORDERLINE...THUS MENTION SNOW TOO. LATE SATURDAY NIGHT INTO SUNDAY...TEMPERATURES COOL BACK DOWN...AS ENERGY TRANSFERS TO COASTAL LOW. MAINLY DRY FOR NEXT MONDAY. DID NOT CHANGE MUCH ON THIS PACKAGE. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... IFR VIS AND LOW MVFR CIGS WILL BE THE RULE AT CENTRAL AND WESTERN TAFS THROUGH THIS AFTERNOON. A SHARP COLD FRONT WILL SWEEP EASTWARD ACROSS THE AIRSPACE THIS AFTERNOON...WITH SNOW SHOWERS AND BRIEF SQUALLS THAT WILL DRAMATICALLY REDUCE VISIBILITY AND CONTAIN VERY GUSTY WINDS. WINDS OVERALL WILL BECOME GUSTY OUT OF THE WEST AGAIN BEHIND THE FRONT WITH PEAK WINDS OF 30-40 MPH THROUGH THE EVENING. CONDITIONS SHOULD RETURN TO VFR FOR CENTRAL AND EAST LATER THIS EVENING...BUT RESTRICTIONS WILL PERSIST IN THE WESTERN HIGHER TERRAIN. WINDS RELAX INTO WEDNESDAY...AND IFR RESTRICTIONS SHOULD TREND TOWARD MVFR BY LATER IN THE DAY. OUTLOOK... WED-FRI...CIG/VSBY REDUCTIONS LIKELY NW HALF IN SNOW SHOWERS. VFR ELSEWHERE. SAT...REDUCTIONS POSS WITH CHANCE FOR RAIN/SNOW. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY MORNING FOR PAZ004-005. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ004- 005. WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ006- 010-011-017-024-033. && $$ SYNOPSIS...STEINBUGL NEAR TERM...STEINBUGL SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...STEINBUGL
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
1249 PM EST TUE JAN 12 2016 .SYNOPSIS... A STRONG ALBERTA CLIPPER WILL PASS JUST NORTH OF THE REGION THIS AFTERNOON DRAGGING A TRAILING ARCTIC COLD FRONT THROUGH US BY THIS EVENING. COLD HIGH PRESSURE FOLLOWS THE FRONT FOR THE MIDDLE OF THE WEEK. LOW PRESSURE MOVES FROM THE GULF COAST FRIDAY MORNING TO THE MID ATLANTIC SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM EST TUESDAY... SEEING STRONGER GUSTS AHEAD OF THE FRONT ACROSS THE EASTERN SLOPES OF THE BLUE RIDGE INCLUDING PARTS OF THE FOOTHILLS SO HAVE EXTENDED THE WIND ADVISORY EAST ANOTHER ROW OF COUNTIES. STRONGEST SPEEDS STILL LOOK TO OCCUR WITH THE FRONTAL PASSAGE LATER THIS AFTERNOON. ALSO ADJUSTED TEMPS UP SOME ESPCLY IN THE EAST PER CURRENT OBS OTHERWISE POPS/SNOWFALL STILL ON TRACK SO FEW CHANGES THERE. PREVIOUS UPDATE AS OF 945 AM EST TUESDAY... INITIAL BATCH OF LIGHT SNOW/SNOW SHOWERS WELL AHEAD OF THE ACTUAL COLD FRONT BACK IN THE OHIO VALLEY HAS CONTINUED TO SLOWLY FADE UPON CROSSING WEST VA WHILE ENCOUNTERING DRY AIR PER CURRENT DEWPOINTS. LATEST HRRR AND THE HIRES-ARW CATCH ON TO THIS PRETTY WELL AND DON`T SHOW MUCH ADDED COVERAGE UNTIL THE FRONT ARRIVES EARLY THIS AFTERNOON OVER THE FAR WEST. SHOULD THEN SEE A NARROW SWATH OF SNOW ATTEMPT TO CROSS FROM WEST TO EAST ESPCLY BETWEEN 18Z-23Z WHEN THE 85H BOUNDARY SURGES THROUGH UNDER PASSING SHORTWAVE ENERGY IN THE BASE OF THE 5H TROUGH. WITHIN THIS PERIOD ALSO EXPECT SOME MORE EAST-WEST ORIENTED BANDS TO DEVELOP BEHIND THE MAIN AXIS OF SNOW. LATEST SNOW SQUALL PARAMETER SUGGESTS THE HEAVIEST BURST OF SNOW ALONG THE WESTERN SLOPES WITH SOME OF THE WIND BLOWN ACCUMULATING SNOW LIKELY MAKING IT OUT TOWARD THE BLUE RIDGE IN SPOTS. LATEST 12Z NAM STILL SUPPORTING A FEW INCHES FAR NW AND 1-3 INCHES FROM BLF TO HSP AND POINTS WEST SO KEEPING THOSE HEADLINES OVER SOUTHEAST WEST VA WITH LITTLE CHANGE FOR NOW. STEEP LAPSES ALSO SUPPORT SOME SHOWERY NATURE COVERAGE MAKING IT EAST OF THE MOUNTAINS GIVEN SUCH STRONG WESTERLY FLOW ALOFT WITH NCAR PTYPE PROGS INDICATING BRIEF RAIN BEFORE QUICK COOLING CAUSES A CHANGE TO SNOW SHOWERS EVEN WITH TEMPS WELL ABOVE FREEZING. THUS EXTENDED LIGHT AMOUNTS OUT TO THE BLUE RIDGE ESPCLY GIVEN MID/LATE AFTERNOON TIMING. THIS IS WHERE THE MAIN CONCERN EXISTS WITH INITIAL MELTING...THEN A QUICK DROP BELOW FREEZING FOLLOWED BY A LIGHT SNOW COATING ON TOP. PLAN TO ADDRESS THIS WITH SPECIAL WEATHER STATEMENTS LATER PENDING THE DEGREE OF COVERAGE THAT COULD WARRANT A BRIEF HEADLINE. KEPT HIGH TEMPS CLOSE TO PREVIOUS EXCEPT LOWERED A BIT OUT WEST WHERE EARLY CLOUDS LIKELY TO KEEP VALUES COLDER. WINDS THE OTHER CONCERN AND JUST HOW DEEP MIXING WILL BE GIVEN CLOUDS BUT ALSO A QUICK CHANGE IN 85H TEMPS ALONG WITH A 40-45 KT JET. LOOKS LIKE A SURGE TO ADVISORY LEVELS LIKELY WHERE THE ADVISORY IS ALREADY ONGOING WITH A BRIEF INCREASE TO NEAR CRITERIA FOR AN HOUR OR TWO EVEN IN THE PIEDMONT WITH THE FRONT AND POSSIBLE MOMENTUM MIX DOWN WITH ANY SHOWERS. FOR NOW SINCE APPEARS WILL BE A SHORT EVENT...WILL HOLD OFF ADDING A WIND ADVISORY EAST OF THE MOUNTAINS TO SEE HOW THINGS UNFOLD EARLY ON...WHILE BEEFING UP SPEEDS ESPCLY ALONG THE FOOTHILLS AND SPOTS ACROSS THE SOUTH. PREVIOUS DISCUSSION AS OF 345 AM EST TUESDAY... ACTIVE WEATHER THIS PERIOD...WITH THREAT OF ACCUMULATING SNOW SHOWERS AND SNOW SQUALLS OVER THE WV MTNS THIS AFTERNOON AND EVENING...ALONG WITH STRONG WIND GUSTS BEHIND THE ARCTIC FRONT. LOOKING AT INCREASING CLOUDS THIS MORNING. REGIONAL RADAR SHOWED LIGHT RETURNS AS FAR EAST AS HTS WV...WITH MODELS ON TRACK IN BRINGING SNOW SHOWERS INTO WV MTNS AND ALLEGHANYS BY MID TO LATE MORNING. THE BEST LIFT AND INSTABILITY WITH THIS SYSTEM SHOULD ARRIVE AFTER 2PM AND LAST UNTIL 9PM. CROSS SECTIONS AND SNOW SQUALL PARAMETERS INDICATE ENOUGH FRONTOGENETICAL FORCING WITH THE SURGE OF COLDER AIR WITH THE FRONT TO PRODUCE A FEW SNOW SQUALLS OVER THE WV MTNS AND PERHAPS INTO ADJACENT PORTIONS OF THE ALLEGHANY HIGHLANDS AND MTN EMPIRE OF SW VA AROUND 21Z-00Z TODAY. THE TRACK OF THE UPPER VORT FAVORS BEST SNOW ACCUMULATIONS ALONG AND NORTH OF A BKW-HSP LINE. THIS TRACK AND THE STRENGTH/TIMING OF THIS SYSTEM SHOULD SEND SNOW SHOWERS/FLURRIES AS FAR EAST AS LYNCHBURG AND APPOMATTOX THIS AFTERNOON...WITH SOME RAIN MIXED IN EARLY BEFORE 8H TEMPS CRASH BY 00Z. AT THIS TIME...ACCUMULATIONS WILL RANG FROM 2 TO 5 INCHES FROM FLAT TOP WV TO WRN GREENBRIER WHICH TAKES INTO ACCOUNT A LIMITED WINDOW OF UPSLOPE BEHIND THE FRONT THIS EVENING...AS THINK THE MOISTURE WILL DRY UP FAST GIVEN LACK OF UPSTREAM TRAJECTORY OFF THE LAKES. THE 1 INCH LINE WILL REACH LEWISBURG WV TO PRINCETON WV...WITH ISOLATED 1 INCH + AMOUNTS POSSIBLE ACROSS THE HIGHER PEAKS OF THE NEW RIVER VALLEY INTO THE NC MTNS...LIKE MOUNTAIN LAKE...MT ROGERS. A DUSTING OF SNOW IS POSSIBLE AS FAR EAST AS THE BLUE RIDGE INTO PORTIONS OF THE VA FOOTHILLS NORTH OF HIGHWAY 460. TIMING OF THE COLDER AIR FAVORS A NORMAL DIURNAL CURVE FOR MOST OF THE FORECAST AREA WITH FALLING TEMPS AFTER 3-4PM IN THE MTNS. HIGH TEMPS WILL RANGE FROM THE LOWER TO MID 30S FAR WEST TO UPPER 30S NEW RIVER VALLEY...MID TO UPPER 40S ROANOKE EAST TO THE PIEDMONT WITH SOME AREAS LIKE DANVILLE/SOUTH BOSTON REACH 50. AS FOR WINDS THE COLD ADVECTION HITS BY 21Z BEHIND THE FRONT WITH 45+KT 8H JET MOVING ACROSS WITH PRESSURE RISES OF 5-9MB...HIGHEST IN NRN VA/SHENANDOAH VALLEY ENDING AT 00Z. THIS WILL BE ENOUGH TO BRING 50 MPH WIND GUSTS TO RIDGES OF NW NC UP THE BLUE RIDGE OF VA INCLUDING THE RIDGES OF FAR SW VA. THIS WIND EVENT LOOKS TO BE IN A SMALL WINDOW FROM 21Z/5PM TIL 03Z/10PM...BUT TIMING OF THE FRONT MAY BRING STRONGER GUSTS EARLIER TO THE MTNS OF FAR SW VA/NW NC...LINGERING TIL MIDNIGHT OVER THE HIGHER PEAKS OF THE ALLEGHANYS. THEREFORE HAVE HOISTED A WIND ADVISORY FOR MUCH OF THE AREA ALONG/WEST OF THE BLUE RIDGE FROM NOON TODAY TIL MIDNIGHT TONIGHT. AS WE HEAD PAST MIDNIGHT...SNOW SHOWERS AND WINDS TAPER OFF WITH CLEAR SKIES OVER MOST OF THE AREA. WITH SNOW COVER EXPECTED IN THE MTNS LOWS OVER SE WV COULD REACH THE SINGLE DIGITS. LOWS OVER MOST OF THE WEST WILL BE IN THE TEENS...WITH LOWER 20S EAST. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 AM EST TUESDAY... HIGH PRESSURE WILL BUILD EAST INTO OUR REGION WEDNESDAY AND SLIDE OFF THE COAST ON THURSDAY. MOISTURE SLOWLY RETURNS THURSDAY NIGHT AHEAD OF LOW PRESSURE TO THE SOUTH AND WEST. RAIN IS EXPECTED FOR THE END OF THE WORKWEEK. FLOW BECOME MORE ZONAL WEDNESDAY AS THE COLDEST AIR ALOFT EXITS TO THE RIGHT. SUNSHINE INCREASES AS HIGH PRESSURE BUILDS ACROSS THE MOUNTAINS. HIGH TEMPERATURES WEDNESDAY WILL REMAIN COOL WITH READINGS FROM AROUND 20 DEGREES IN THE NORTHWEST MOUNTAINS TO NEAR 40 DEGREES IN THE PIEDMONT. A 500MB SHORTWAVE SLIDES BY TO THE NORTH LATER WEDNESDAY NIGHT INTO EARLY THURSDAY RESULTING IN SOME ADDITIONAL CLOUDS/MOISTURE MAINLY NORTHWEST. THIS SHOULD FLATTEN THE HIGH AND PUSH THE HIGH TO THE SOUTH. AN ISOLATED SNOW SHOWER OR SNOW FLURRIES MAY BE POSSIBLE IN THE NORTHWEST. OTHERWISE...LOOKS QUITE DRY WITH WESTERLY FLOW. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE MID 20S IN THE PIEDMONT. THE 1023 MB SURFACE HIGH STARTS TO SHIFT OFFSHORE THURSDAY AS HEIGHTS RISE WITH THE 5H TROUGH LIFTING BACK NORTH LEAVING AN ENSUING STRONG WESTERLY GRADIENT IN PLACE. STRONG WARM ADVECTION IS EXPECTED WITH A GOOD 5-8C INCREASE IN FORECAST 85H TEMPERATURES. HIGH TEMPERATURES WILL WARM INTO THE UPPER 30S IN THE MOUNTAINS TO NEAR 50 DEGREES IN THE PIEDMONT. AS SURFACE HIGH PRESSURE SHIFTS FARTHER OFFSHORE THURSDAY NIGHT...A RETURN SOUTHERLY FLOW WILL DEVELOP AHEAD OF LOW PRESSURE TO THE SOUTH AND WEST. LOW TEMPERATURES THURSDAY NIGHT WILL GENERALLY BE IN THE MID 20S TO THE LOWER 30S. LOW PRESSURE FROM THE GULF OF MEXICO WILL TRAVEL NORTHEAST FRIDAY AND REACH THE VIRGINIA CAPES BY FRIDAY NIGHT. THERE STILL REMAINS SOME DIFFERENCE IN THE MODELS REGARDING ANY PHASING WITH THE NORTHERN STREAM 5H TROUGH LIFTS THROUGH THE OHIO VALLEY FRIDAY NIGHT. IN ANY CASE...MOISTURE STARTS IN THE SOUTH AND SPREAD NORTHWARD ON FRIDAY. HIGHS ON FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT. AS THE LOW CENTER PUSH NORTHEAST OFF THE JERSEY SHORE FRIDAY NIGHT...DRIER AIR WILL PUSH NORTH INTO SOUTHEAST PORTIONS OF FORECAST AREA. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE THE UPPER 20S IN THE MOUNTAINS TO THE MID 30S IN THE PIEDMONT. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... AS OF 300 AM EST TUESDAY... BROAD TROUGHING WILL REMAIN OVER THE EAST THROUGH THE WEEKEND...AS A DEEP UPPER VORTEX SINKS DOWN FROM CANADA AND ROTATES OVER THE GREAT LAKES. RAIN TAPERS OFF EAST OF THE BLUE RIDGE SATURDAY...AS A TRAILING DRY SLOT PUNCHES IN. NORTHERN STREAM UPPER LOW WILL THEN BE THE MAIN PLAYER FROM LATER SATURDAY INTO SUNDAY NIGHT WITH PERIODIC UPSLOPE SNOW SHOWERS LIKELY WEST AS DEEPER COLD ADVECTION ARRIVES AND MOISTURE LINGERS. APPEARS BEST CHANCES OF SNOW SHOWERS WILL BE SUNDAY AS THE CORE OF THE UPPER TROUGH PIVOTS THROUGH AIDED BY ANOTHER MID LEVEL WAVE PASSING DURING STRONG 85H COLD ADVECTION. SOME OF THESE SNOW/RAIN SHOWERS COULD EVEN CROSS THE MOUNTAINS SUNDAY AFTERNOON SO KEPT IN MENTION WITH LIKELY INCREASE IN LAPSES OUT EAST. OTRW TURNING BLUSTERY AND COLDER AGAIN OVER THE WEEKEND WITH MAINLY MOUNTAIN SNOW SHOWERS BEFORE TAPERING MONDAY UNDER WEAK HIGH PRESSURE AHEAD OF THE NEXT UPSTREAM WAVE. HIGHS MOSTLY 30S/40S AND LOWS TEENS/20S SUNDAY-MONDAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 1140 AM EST TUESDAY... CLOUDS WILL GRADUALLY INCREASE FROM WEST TO EAST THIS AFTERNOON WITH CIGS LOWERING TO MVFR OVER THE FAR WEST AT KBLF/KLWB AND PERHAPS AT TIMES AROUND KBCB BY LATE AFTERNOON. SNOW SHOWERS WILL ALSO QUICKLY INCREASE AS WELL OVER THE MOUNTAINS WITH MODERATE TO HEAVY SNOW SHOWERS POSSIBLE AT ACROSS THE SOUTHEAST WEST VA SITES DURING THE MID TO LATE AFTERNOON TIME FRAME. SNOW SHOWERS MAY IMPACT KROA/KBCB AS WELL WITH VSBYS BRIEFLY DIPPING TO MVFR PENDING EXACTLY WHERE A HEAVIER BAND OF SNOW SHOWERS SETS UP. WINDS WILL BE ANOTHER ISSUE AS THEY CONTINUE TO INCREASE AHEAD OF THE FRONT FROM THE SW THEN TURN WEST BEHIND THE FRONT FIRST AT KBLF/KLWB AROUND 19-20Z/2-3PM...THEN KROA/KBCB ANOTHER HOUR OR SO AFTER THAT...FINALLY CLEARING KDAN/KLYH JUST AFTER SUNSET. WIND SPEEDS WILL BE SUSTAINED FROM 15 TO 25 KTS WITH GUSTS AS HIGH AS 30-40KTS AT THE HIGHER ELEVATIONS INCLUDING KROA/KBCB AT TIMES. COULD EVEN SEE BRIEF GUSTS TOP 30-35 KTS OUT EAST AT KLYH/KDAN WHEN THE FRONT CROSSES LATE THIS AFTERNOON. WINDS WILL DIMINISH TO LESS THAN 20KTS THIS EVENING...ESPECIALLY EAST OF THE BLUE RIDGE. MVFR CIGS WILL LIKELY PREVAIL AT KLWB/KBLF OVERNIGHT...BUT IMPROVE TO VFR ALONG THE BLUE RIDGE AFTER MIDNIGHT WHILE STAYING VFR IN THE EAST. HIGH PRESSURE BUILDS IN FROM THE WEST WEDNESDAY...RETURNING ALL LOCATIONS TO VFR DURING THE MORNING AFTER ANY EARLY LOW CIGS OVER THE FAR WEST FINALLY ERODE. WESTERLY WINDS SHOULD ALSO BE LESS WITH SPEEDS MAINLY 5-15 KTS OVERALL. MEDIUM CONFIDENCE IN VSBYS/CEILINGS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND SPEED/DIRECTION THROUGH THE TAF VALID PERIOD. .EXTENDED AVIATION DISCUSSION... THE HIGH MOVES TO THE SOUTHEAST COAST THURSDAY AS WINDS BACK TO THE WEST OR SW. MOISTURE RETURNS AGAIN FRIDAY AS MULTIPLE AREAS OF LOW PRESSURE PASS TO THE SOUTH AND WEST OF THE REGION. THIS WILL BRING THE POTENTIAL FOR SUB-VFR CEILINGS AND LIGHT PRECIPITATION...MAINLY LIQUID...BY FRIDAY EVENING...WHICH WILL PERSIST INTO EARLY SATURDAY. DRIER AIR FOLLOWING THESE SYSTEMS SHOULD ALLOW FOR A RETURN TO VFR EAST OF THE MOUNTAINS SATURDAY AFTERNOON WITH LINGERING MVFR AND SNOW SHOWERS OVER THE WESTERN MOUNTAINS. ANOTHER WEAK IMPULSE MAY SWING THROUGH THE REGION FROM THE SOUTHWEST BY SUNDAY WITH PERHAPS ANOTHER ROUND OF SUB-VFR CIGS AND LIGHT PRECIP. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VAZ007-009>020- 022>024-032>035. NC...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ001>003-018- 019. WV...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ044-507. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ042- 043-508. && $$ SYNOPSIS...JH/WP NEAR TERM...JH/WP SHORT TERM...KK LONG TERM...JH/KK AVIATION...JH/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1145 AM EST TUE JAN 12 2016 .SYNOPSIS... A STRONG ALBERTA CLIPPER WILL PASS JUST NORTH OF THE REGION THIS AFTERNOON DRAGGING A TRAILING ARCTIC COLD FRONT THROUGH US BY THIS EVENING. COLD HIGH PRESSURE FOLLOWS THE FRONT FOR THE MIDDLE OF THE WEEK. LOW PRESSURE MOVES FROM THE GULF COAST FRIDAY MORNING TO THE MID ATLANTIC SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM EST TUESDAY... INITIAL BATCH OF LIGHT SNOW/SNOW SHOWERS WELL AHEAD OF THE ACTUAL COLD FRONT BACK IN THE OHIO VALLEY HAS CONTINUED TO SLOWLY FADE UPON CROSSING WEST VA WHILE ENCOUNTERING DRY AIR PER CURRENT DEWPOINTS. LATEST HRRR AND THE HIRES-ARW CATCH ON TO THIS PRETTY WELL AND DON`T SHOW MUCH ADDED COVERAGE UNTIL THE FRONT ARRIVES EARLY THIS AFTERNOON OVER THE FAR WEST. SHOULD THEN SEE A NARROW SWATH OF SNOW ATTEMPT TO CROSS FROM WEST TO EAST ESPCLY BETWEEN 18Z-23Z WHEN THE 85H BOUNDARY SURGES THROUGH UNDER PASSING SHORTWAVE ENERGY IN THE BASE OF THE 5H TROUGH. WITHIN THIS PERIOD ALSO EXPECT SOME MORE EAST-WEST ORIENTED BANDS TO DEVELOP BEHIND THE MAIN AXIS OF SNOW. LATEST SNOW SQUALL PARAMETER SUGGESTS THE HEAVIEST BURST OF SNOW ALONG THE WESTERN SLOPES WITH SOME OF THE WIND BLOWN ACCUMULATING SNOW LIKELY MAKING IT OUT TOWARD THE BLUE RIDGE IN SPOTS. LATEST 12Z NAM STILL SUPPORTING A FEW INCHES FAR NW AND 1-3 INCHES FROM BLF TO HSP AND POINTS WEST SO KEEPING THOSE HEADLINES OVER SOUTHEAST WEST VA WITH LITTLE CHANGE FOR NOW. STEEP LAPSES ALSO SUPPORT SOME SHOWERY NATURE COVERAGE MAKING IT EAST OF THE MOUNTAINS GIVEN SUCH STRONG WESTERLY FLOW ALOFT WITH NCAR PTYPE PROGS INDICATING BRIEF RAIN BEFORE QUICK COOLING CAUSES A CHANGE TO SNOW SHOWERS EVEN WITH TEMPS WELL ABOVE FREEZING. THUS EXTENDED LIGHT AMOUNTS OUT TO THE BLUE RIDGE ESPCLY GIVEN MID/LATE AFTERNOON TIMING. THIS IS WHERE THE MAIN CONCERN EXISTS WITH INITIAL MELTING...THEN A QUICK DROP BELOW FREEZING FOLLOWED BY A LIGHT SNOW COATING ON TOP. PLAN TO ADDRESS THIS WITH SPECIAL WEATHER STATEMENTS LATER PENDING THE DEGREE OF COVERAGE THAT COULD WARRANT A BRIEF HEADLINE. KEPT HIGH TEMPS CLOSE TO PREVIOUS EXCEPT LOWERED A BIT OUT WEST WHERE EARLY CLOUDS LIKELY TO KEEP VALUES COLDER. WINDS THE OTHER CONCERN AND JUST HOW DEEP MIXING WILL BE GIVEN CLOUDS BUT ALSO A QUICK CHANGE IN 85H TEMPS ALONG WITH A 40-45 KT JET. LOOKS LIKE A SURGE TO ADVISORY LEVELS LIKELY WHERE THE ADVISORY IS ALREADY ONGOING WITH A BRIEF INCREASE TO NEAR CRITERIA FOR AN HOUR OR TWO EVEN IN THE PIEDMONT WITH THE FRONT AND POSSIBLE MOMENTUM MIX DOWN WITH ANY SHOWERS. FOR NOW SINCE APPEARS WILL BE A SHORT EVENT...WILL HOLD OFF ADDING A WIND ADVISORY EAST OF THE MOUNTAINS TO SEE HOW THINGS UNFOLD EARLY ON...WHILE BEEFING UP SPEEDS ESPCLY ALONG THE FOOTHILLS AND SPOTS ACROSS THE SOUTH. PREVIOUS DISCUSSION AS OF 345 AM EST TUESDAY... ACTIVE WEATHER THIS PERIOD...WITH THREAT OF ACCUMULATING SNOW SHOWERS AND SNOW SQUALLS OVER THE WV MTNS THIS AFTERNOON AND EVENING...ALONG WITH STRONG WIND GUSTS BEHIND THE ARCTIC FRONT. LOOKING AT INCREASING CLOUDS THIS MORNING. REGIONAL RADAR SHOWED LIGHT RETURNS AS FAR EAST AS HTS WV...WITH MODELS ON TRACK IN BRINGING SNOW SHOWERS INTO WV MTNS AND ALLEGHANYS BY MID TO LATE MORNING. THE BEST LIFT AND INSTABILITY WITH THIS SYSTEM SHOULD ARRIVE AFTER 2PM AND LAST UNTIL 9PM. CROSS SECTIONS AND SNOW SQUALL PARAMETERS INDICATE ENOUGH FRONTOGENETICAL FORCING WITH THE SURGE OF COLDER AIR WITH THE FRONT TO PRODUCE A FEW SNOW SQUALLS OVER THE WV MTNS AND PERHAPS INTO ADJACENT PORTIONS OF THE ALLEGHANY HIGHLANDS AND MTN EMPIRE OF SW VA AROUND 21Z-00Z TODAY. THE TRACK OF THE UPPER VORT FAVORS BEST SNOW ACCUMULATIONS ALONG AND NORTH OF A BKW-HSP LINE. THIS TRACK AND THE STRENGTH/TIMING OF THIS SYSTEM SHOULD SEND SNOW SHOWERS/FLURRIES AS FAR EAST AS LYNCHBURG AND APPOMATTOX THIS AFTERNOON...WITH SOME RAIN MIXED IN EARLY BEFORE 8H TEMPS CRASH BY 00Z. AT THIS TIME...ACCUMULATIONS WILL RANG FROM 2 TO 5 INCHES FROM FLAT TOP WV TO WRN GREENBRIER WHICH TAKES INTO ACCOUNT A LIMITED WINDOW OF UPSLOPE BEHIND THE FRONT THIS EVENING...AS THINK THE MOISTURE WILL DRY UP FAST GIVEN LACK OF UPSTREAM TRAJECTORY OFF THE LAKES. THE 1 INCH LINE WILL REACH LEWISBURG WV TO PRINCETON WV...WITH ISOLATED 1 INCH + AMOUNTS POSSIBLE ACROSS THE HIGHER PEAKS OF THE NEW RIVER VALLEY INTO THE NC MTNS...LIKE MOUNTAIN LAKE...MT ROGERS. A DUSTING OF SNOW IS POSSIBLE AS FAR EAST AS THE BLUE RIDGE INTO PORTIONS OF THE VA FOOTHILLS NORTH OF HIGHWAY 460. TIMING OF THE COLDER AIR FAVORS A NORMAL DIURNAL CURVE FOR MOST OF THE FORECAST AREA WITH FALLING TEMPS AFTER 3-4PM IN THE MTNS. HIGH TEMPS WILL RANGE FROM THE LOWER TO MID 30S FAR WEST TO UPPER 30S NEW RIVER VALLEY...MID TO UPPER 40S ROANOKE EAST TO THE PIEDMONT WITH SOME AREAS LIKE DANVILLE/SOUTH BOSTON REACH 50. AS FOR WINDS THE COLD ADVECTION HITS BY 21Z BEHIND THE FRONT WITH 45+KT 8H JET MOVING ACROSS WITH PRESSURE RISES OF 5-9MB...HIGHEST IN NRN VA/SHENANDOAH VALLEY ENDING AT 00Z. THIS WILL BE ENOUGH TO BRING 50 MPH WIND GUSTS TO RIDGES OF NW NC UP THE BLUE RIDGE OF VA INCLUDING THE RIDGES OF FAR SW VA. THIS WIND EVENT LOOKS TO BE IN A SMALL WINDOW FROM 21Z/5PM TIL 03Z/10PM...BUT TIMING OF THE FRONT MAY BRING STRONGER GUSTS EARLIER TO THE MTNS OF FAR SW VA/NW NC...LINGERING TIL MIDNIGHT OVER THE HIGHER PEAKS OF THE ALLEGHANYS. THEREFORE HAVE HOISTED A WIND ADVISORY FOR MUCH OF THE AREA ALONG/WEST OF THE BLUE RIDGE FROM NOON TODAY TIL MIDNIGHT TONIGHT. AS WE HEAD PAST MIDNIGHT...SNOW SHOWERS AND WINDS TAPER OFF WITH CLEAR SKIES OVER MOST OF THE AREA. WITH SNOW COVER EXPECTED IN THE MTNS LOWS OVER SE WV COULD REACH THE SINGLE DIGITS. LOWS OVER MOST OF THE WEST WILL BE IN THE TEENS...WITH LOWER 20S EAST. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 AM EST TUESDAY... HIGH PRESSURE WILL BUILD EAST INTO OUR REGION WEDNESDAY AND SLIDE OFF THE COAST ON THURSDAY. MOISTURE SLOWLY RETURNS THURSDAY NIGHT AHEAD OF LOW PRESSURE TO THE SOUTH AND WEST. RAIN IS EXPECTED FOR THE END OF THE WORKWEEK. FLOW BECOME MORE ZONAL WEDNESDAY AS THE COLDEST AIR ALOFT EXITS TO THE RIGHT. SUNSHINE INCREASES AS HIGH PRESSURE BUILDS ACROSS THE MOUNTAINS. HIGH TEMPERATURES WEDNESDAY WILL REMAIN COOL WITH READINGS FROM AROUND 20 DEGREES IN THE NORTHWEST MOUNTAINS TO NEAR 40 DEGREES IN THE PIEDMONT. A 500MB SHORTWAVE SLIDES BY TO THE NORTH LATER WEDNESDAY NIGHT INTO EARLY THURSDAY RESULTING IN SOME ADDITIONAL CLOUDS/MOISTURE MAINLY NORTHWEST. THIS SHOULD FLATTEN THE HIGH AND PUSH THE HIGH TO THE SOUTH. AN ISOLATED SNOW SHOWER OR SNOW FLURRIES MAY BE POSSIBLE IN THE NORTHWEST. OTHERWISE...LOOKS QUITE DRY WITH WESTERLY FLOW. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE MID 20S IN THE PIEDMONT. THE 1023 MB SURFACE HIGH STARTS TO SHIFT OFFSHORE THURSDAY AS HEIGHTS RISE WITH THE 5H TROUGH LIFTING BACK NORTH LEAVING AN ENSUING STRONG WESTERLY GRADIENT IN PLACE. STRONG WARM ADVECTION IS EXPECTED WITH A GOOD 5-8C INCREASE IN FORECAST 85H TEMPERATURES. HIGH TEMPERATURES WILL WARM INTO THE UPPER 30S IN THE MOUNTAINS TO NEAR 50 DEGREES IN THE PIEDMONT. AS SURFACE HIGH PRESSURE SHIFTS FARTHER OFFSHORE THURSDAY NIGHT...A RETURN SOUTHERLY FLOW WILL DEVELOP AHEAD OF LOW PRESSURE TO THE SOUTH AND WEST. LOW TEMPERATURES THURSDAY NIGHT WILL GENERALLY BE IN THE MID 20S TO THE LOWER 30S. LOW PRESSURE FROM THE GULF OF MEXICO WILL TRAVEL NORTHEAST FRIDAY AND REACH THE VIRGINIA CAPES BY FRIDAY NIGHT. THERE STILL REMAINS SOME DIFFERENCE IN THE MODELS REGARDING ANY PHASING WITH THE NORTHERN STREAM 5H TROUGH LIFTS THROUGH THE OHIO VALLEY FRIDAY NIGHT. IN ANY CASE...MOISTURE STARTS IN THE SOUTH AND SPREAD NORTHWARD ON FRIDAY. HIGHS ON FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT. AS THE LOW CENTER PUSH NORTHEAST OFF THE JERSEY SHORE FRIDAY NIGHT...DRIER AIR WILL PUSH NORTH INTO SOUTHEAST PORTIONS OF FORECAST AREA. LOW TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE THE UPPER 20S IN THE MOUNTAINS TO THE MID 30S IN THE PIEDMONT. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... AS OF 300 AM EST TUESDAY... BROAD TROUGHING WILL REMAIN OVER THE EAST THROUGH THE WEEKEND...AS A DEEP UPPER VORTEX SINKS DOWN FROM CANADA AND ROTATES OVER THE GREAT LAKES. RAIN TAPERS OFF EAST OF THE BLUE RIDGE SATURDAY...AS A TRAILING DRY SLOT PUNCHES IN. NORTHERN STREAM UPPER LOW WILL THEN BE THE MAIN PLAYER FROM LATER SATURDAY INTO SUNDAY NIGHT WITH PERIODIC UPSLOPE SNOW SHOWERS LIKELY WEST AS DEEPER COLD ADVECTION ARRIVES AND MOISTURE LINGERS. APPEARS BEST CHANCES OF SNOW SHOWERS WILL BE SUNDAY AS THE CORE OF THE UPPER TROUGH PIVOTS THROUGH AIDED BY ANOTHER MID LEVEL WAVE PASSING DURING STRONG 85H COLD ADVECTION. SOME OF THESE SNOW/RAIN SHOWERS COULD EVEN CROSS THE MOUNTAINS SUNDAY AFTERNOON SO KEPT IN MENTION WITH LIKELY INCREASE IN LAPSES OUT EAST. OTRW TURNING BLUSTERY AND COLDER AGAIN OVER THE WEEKEND WITH MAINLY MOUNTAIN SNOW SHOWERS BEFORE TAPERING MONDAY UNDER WEAK HIGH PRESSURE AHEAD OF THE NEXT UPSTREAM WAVE. HIGHS MOSTLY 30S/40S AND LOWS TEENS/20S SUNDAY-MONDAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 1140 AM EST TUESDAY... CLOUDS WILL GRADUALLY INCREASE FROM WEST TO EAST THIS AFTERNOON WITH CIGS LOWERING TO MVFR OVER THE FAR WEST AT KBLF/KLWB AND PERHAPS AT TIMES AROUND KBCB BY LATE AFTERNOON. SNOW SHOWERS WILL ALSO QUICKLY INCREASE AS WELL OVER THE MOUNTAINS WITH MODERATE TO HEAVY SNOW SHOWERS POSSIBLE AT ACROSS THE SOUTHEAST WEST VA SITES DURING THE MID TO LATE AFTERNOON TIME FRAME. SNOW SHOWERS MAY IMPACT KROA/KBCB AS WELL WITH VSBYS BRIEFLY DIPPING TO MVFR PENDING EXACTLY WHERE A HEAVIER BAND OF SNOW SHOWERS SETS UP. WINDS WILL BE ANOTHER ISSUE AS THEY CONTINUE TO INCREASE AHEAD OF THE FRONT FROM THE SW THEN TURN WEST BEHIND THE FRONT FIRST AT KBLF/KLWB AROUND 19-20Z/2-3PM...THEN KROA/KBCB ANOTHER HOUR OR SO AFTER THAT...FINALLY CLEARING KDAN/KLYH JUST AFTER SUNSET. WIND SPEEDS WILL BE SUSTAINED FROM 15 TO 25 KTS WITH GUSTS AS HIGH AS 30-40KTS AT THE HIGHER ELEVATIONS INCLUDING KROA/KBCB AT TIMES. COULD EVEN SEE BRIEF GUSTS TOP 30-35 KTS OUT EAST AT KLYH/KDAN WHEN THE FRONT CROSSES LATE THIS AFTERNOON. WINDS WILL DIMINISH TO LESS THAN 20KTS THIS EVENING...ESPECIALLY EAST OF THE BLUE RIDGE. MVFR CIGS WILL LIKELY PREVAIL AT KLWB/KBLF OVERNIGHT...BUT IMPROVE TO VFR ALONG THE BLUE RIDGE AFTER MIDNIGHT WHILE STAYING VFR IN THE EAST. HIGH PRESSURE BUILDS IN FROM THE WEST WEDNESDAY...RETURNING ALL LOCATIONS TO VFR DURING THE MORNING AFTER ANY EARLY LOW CIGS OVER THE FAR WEST FINALLY ERODE. WESTERLY WINDS SHOULD ALSO BE LESS WITH SPEEDS MAINLY 5-15 KTS OVERALL. MEDIUM CONFIDENCE IN VSBYS/CEILINGS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND SPEED/DIRECTION THROUGH THE TAF VALID PERIOD. .EXTENDED AVIATION DISCUSSION... THE HIGH MOVES TO THE SOUTHEAST COAST THURSDAY AS WINDS BACK TO THE WEST OR SW. MOISTURE RETURNS AGAIN FRIDAY AS MULTIPLE AREAS OF LOW PRESSURE PASS TO THE SOUTH AND WEST OF THE REGION. THIS WILL BRING THE POTENTIAL FOR SUB-VFR CEILINGS AND LIGHT PRECIPITATION...MAINLY LIQUID...BY FRIDAY EVENING...WHICH WILL PERSIST INTO EARLY SATURDAY. DRIER AIR FOLLOWING THESE SYSTEMS SHOULD ALLOW FOR A RETURN TO VFR EAST OF THE MOUNTAINS SATURDAY AFTERNOON WITH LINGERING MVFR AND SNOW SHOWERS OVER THE WESTERN MOUNTAINS. ANOTHER WEAK IMPULSE MAY SWING THROUGH THE REGION FROM THE SOUTHWEST BY SUNDAY WITH PERHAPS ANOTHER ROUND OF SUB-VFR CIGS AND LIGHT PRECIP. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VAZ007-009>020- 022>024-035. NC...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ001-002-018. WV...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ044-507. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ042- 043-508. && $$ SYNOPSIS...JH/WP NEAR TERM...JH/WP SHORT TERM...KK LONG TERM...JH/KK AVIATION...JH/RAB/WP