Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/09/14


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
230 PM MST FRI FEB 7 2014 .UPDATE...UPDATED AVIATION DISCUSSION... .SYNOPSIS... STRONG HIGH PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND WITH MUCH WARMER CONDITIONS BY EARLY NEXT WEEK. THESE ABNORMALLY WARM AND DRY CONDITIONS SHOULD PREVAIL THROUGH ALL OF NEXT WEEK. && .DISCUSSION... STRONG JET STREAK ALONG THE WEST COAST IS PRODUCING WIDESPREAD BENEFICIAL RAIN ACROSS THE DROUGHT-STRICKEN AREAS OF NORTHERN AND CENTRAL CA. FURTHER SOUTHEAST ACROSS THE DESERT SOUTHWEST...SHARP HEIGHT RISES HAVE BEEN OBSERVED WITH CIRRUS SPILLING OVER THE BUILDING EASTERN PACIFIC RIDGE. LEFTOVER LOW-LEVEL MOISTURE IN THE WAKE OF THE SHORT-WAVE TROUGH NOW LOCATED IN TX IS ALSO LEADING TO THE DEVELOPMENT OF BACK-BUILDING CU FROM THE MOGOLLON RIM INTO THE LOWER DESERTS. HOWEVER...VERTICAL MOTION IS GENERALLY SUBSIDENT AND RADAR IMAGERY SHOWS LITTLE IN THE WAY OF PRECIPITATION. HI-RES GUIDANCE INCLUDING THE LATEST HRRR INDICATES NO POTENTIAL FOR ADDITIONAL PRECIPITATION THROUGH THIS EVENING AND POPS REMAIN NEAR 0 PERCENT. && .PREVIOUS DISCUSSION... FLAT RIDGING AND QUASI-ZONAL FLOW WILL PREDOMINATE OVER THE REGION THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. H5 HEIGHTS WILL BE CHARACTERIZED BETWEEN 576DM AND 582DM WITH H8 TEMPERATURES REACHING TOWARDS A +12C TO +15C RANGE. THIS COMBINATION NEARLY MIRRORS CONDITIONS EXPERIENCED DURING THE MIDDLE/END OF JANUARY...AND CONFIDENCE IS HIGH THAT ABOVE NORMAL TEMPERATURES WILL PREVAIL. MODELS ARE IN FAIR AGREEMENT SHOWING ANOTHER FAST MOVING WAVE AMPLIFYING NEAR THE FORECAST AREA LATE MONDAY INTO TUESDAY...WITH THE 00Z ECMWF SLIGHTLY FASTER AND MORE DEFINED IN THE WAVE STRUCTURE. REGARDLESS...IMPACTS SHOULD PRIMARILY BE LIMITED TO NORTHERN ARIZONA IN THE FORM OF SCT SHOWERS...WITH ONLY AN INCREASED PRESSURE GRADIENT PROVIDING THE SETUP FOR SOMEWHAT BREEZY CONDITIONS (THOUGH NOTHING UNSEASONABLY STRONG). THEREAFTER...CONTINUED RIDGING AND BROAD WNW FLOW WILL PREVAIL FOR THE REMAINDER OF THE WEEK. ENSEMBLE SPREAD IS UNUSUALLY LOW CONSIDERING THE WINTER SEASON WITH H5 HEIGHTS NOT FAR FROM 580DM THROUGHOUT THE LATTER HALF OF NEXT WEEK. H8 TEMPERATURES SHOULD PUSH ABOVE THE +15C MARK...WITH AFTERNOON 1000-850MB THICKNESS VALUES ECLIPSING 139DM. CONFIDENCE IS VERY HIGH THAT AFTERNOON HIGHS WILL REACH OR EXCEED 5F-10F ABOVE NORMAL FROM WEDNESDAY AND BEYOND...WITH MANY LOWER ELEVATION LOCATIONS EXCEEDING THE 80F THRESHOLD BY THE END OF THE WEEK. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...MID TO HIGH LEVEL SCT CIGS TO BECOME FEW-CLR LATE TONIGHT AND EARLY SATURDAY AS SOMEWHAT DRIER AIR MOVES INTO THE REGION. SCT-BKN MID-LEVEL CIGS TO RETURN ON SAT AFTERNOON AS ANOTHER WEATHER DISTURBANCE THAT WILL BE MOVING INLAND OVER CENTRAL CA BEGINS TO PUSH ANOTHER BATCH OF MID TO HIGH-LEVEL MOISTURE INTO THE REGION. WEAK SFC PRESSURE GRADIENTS TO KEEP WINDS ON THE LIGHT SIDE THROUGH THE TAF PERIOD...WITH THE USUAL DIURNAL TRENDS IN DIRECTION AND SPEEDS. SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH... CLEAR TO MOSTLY CLEAR SKIES TO PREVAIL THROUGH TONIGHT. ANY CLOUDS THAT DO DEVELOP WILL ONLY BE FEW TO SCATTERED IN COVERAGE AND HAVE BASES AOA 10K FEET. SCT-BKN MID-LEVEL CIGS TO RETURN ON SAT AS ANOTHER WEATHER DISTURBANCE THAT WILL BE MOVING INLAND OVER CENTRAL CA BEGINS TO PUSH ANOTHER BATCH OF MID-HIGH LEVEL MOISTURE INTO THE REGION. SCT-BKN MID-LEVEL CIGS TO RETURN ON SAT AS ANOTHER WEATHER DISTURBANCE THAT WILL BE MOVING INLAND OVER CENTRAL CA BEGINS TO PUSH ANOTHER BATCH OF MID-HIGH LEVEL MOISTURE INTO THE REGION. WEAK SFC PRESSURE GRADIENTS TO KEEP WINDS ON THE LIGHT SIDE THROUGH THE TAF PERIOD. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE NEXT COUPLE DAYS...BUT HUMIDITIES WILL REMAIN ELEVATED THROUGH THE WEEKEND. THE ELEVATED MOISTURE LEVELS WILL REMAIN UNTIL DRIER AIR FOLLOWS AFTER A WEAK TROUGH FORECAST TO MOVE THROUGH ON MONDAY. NOT EXPECTING MUCH IN THE WAY OF PRECIP WITH THIS TROUGH...BUT THERE SHOULD BE SOME BREEZY WINDS...ESPECIALLY DOWN THE CO RIVER MONDAY AFTERNOON. MINIMUM HUMIDITIES WILL DECREASE INTO THE TEENS AFTER MONDAY WHILE TEMPERATURES RISE TO WELL ABOVE SEASONAL NORMALS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH PREVIOUS DISCUSSION...MO AVIATION...PERCHA FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
225 PM MST FRI FEB 7 2014 .SYNOPSIS... STRONG HIGH PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND WITH MUCH WARMER CONDITIONS BY EARLY NEXT WEEK. THESE ABNORMALLY WARM AND DRY CONDITIONS SHOULD PREVAIL THROUGH ALL OF NEXT WEEK. && .DISCUSSION... STRONG JET STREAK ALONG THE WEST COAST IS PRODUCING WIDESPREAD BENEFICIAL RAIN ACROSS THE DROUGHT-STRICKEN AREAS OF NORTHERN AND CENTRAL CA. FURTHER SOUTHEAST ACROSS THE DESERT SOUTHWEST...SHARP HEIGHT RISES HAVE BEEN OBSERVED WITH CIRRUS SPILLING OVER THE BUILDING EASTERN PACIFIC RIDGE. LEFTOVER LOW-LEVEL MOISTURE IN THE WAKE OF THE SHORT-WAVE TROUGH NOW LOCATED IN TX IS ALSO LEADING TO THE DEVELOPMENT OF BACK-BUILDING CU FROM THE MOGOLLON RIM INTO THE LOWER DESERTS. HOWEVER...VERTICAL MOTION IS GENERALLY SUBSIDENT AND RADAR IMAGERY SHOWS LITTLE IN THE WAY OF PRECIPITATION. HI-RES GUIDANCE INCLUDING THE LATEST HRRR INDICATES NO POTENTIAL FOR ADDITIONAL PRECIPITATION THROUGH THIS EVENING AND POPS REMAIN NEAR 0 PERCENT. && .PREVIOUS DISCUSSION... FLAT RIDGING AND QUASI-ZONAL FLOW WILL PREDOMINATE OVER THE REGION THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. H5 HEIGHTS WILL BE CHARACTERIZED BETWEEN 576DM AND 582DM WITH H8 TEMPERATURES REACHING TOWARDS A +12C TO +15C RANGE. THIS COMBINATION NEARLY MIRRORS CONDITIONS EXPERIENCED DURING THE MIDDLE/END OF JANUARY...AND CONFIDENCE IS HIGH THAT ABOVE NORMAL TEMPERATURES WILL PREVAIL. MODELS ARE IN FAIR AGREEMENT SHOWING ANOTHER FAST MOVING WAVE AMPLIFYING NEAR THE FORECAST AREA LATE MONDAY INTO TUESDAY...WITH THE 00Z ECMWF SLIGHTLY FASTER AND MORE DEFINED IN THE WAVE STRUCTURE. REGARDLESS...IMPACTS SHOULD PRIMARILY BE LIMITED TO NORTHERN ARIZONA IN THE FORM OF SCT SHOWERS...WITH ONLY AN INCREASED PRESSURE GRADIENT PROVIDING THE SETUP FOR SOMEWHAT BREEZY CONDITIONS (THOUGH NOTHING UNSEASONABLY STRONG). THEREAFTER...CONTINUED RIDGING AND BROAD WNW FLOW WILL PREVAIL FOR THE REMAINDER OF THE WEEK. ENSEMBLE SPREAD IS UNUSUALLY LOW CONSIDERING THE WINTER SEASON WITH H5 HEIGHTS NOT FAR FROM 580DM THROUGHOUT THE LATTER HALF OF NEXT WEEK. H8 TEMPERATURES SHOULD PUSH ABOVE THE +15C MARK...WITH AFTERNOON 1000-850MB THICKNESS VALUES ECLIPSING 139DM. CONFIDENCE IS VERY HIGH THAT AFTERNOON HIGHS WILL REACH OR EXCEED 5F-10F ABOVE NORMAL FROM WEDNESDAY AND BEYOND...WITH MANY LOWER ELEVATION LOCATIONS EXCEEDING THE 80F THRESHOLD BY THE END OF THE WEEK. && .AVIATION... SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...AND KSDL...AND SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH... LINGERING CIGS BETWEEN 6-8K FEET ACROSS SOUTH-CENTRAL ARIZONA WILL QUICKLY SCATTER OUT BY MID MORNING AS HIGH PRESSURE SETTLES INTO THE REGION. WINDS ACROSS THE REGION WILL REMAIN LIGHT THROUGHOUT THE TAF PERIOD FOLLOWING TYPICAL DIRECTIONAL PATTERNS. NO AVIATION IMPACTS EXPECTED AT LEAST THROUGH SATURDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE NEXT COUPLE DAYS...BUT HUMIDITIES WILL REMAIN ELEVATED THROUGH THE WEEKEND. THE ELEVATED MOISTURE LEVELS WILL REMAIN UNTIL DRIER AIR FOLLOWS AFTER A WEAK TROUGH FORECAST TO MOVE THROUGH ON MONDAY. NOT EXPECTING MUCH IN THE WAY OF PRECIP WITH THIS TROUGH...BUT THERE SHOULD BE SOME BREEZY WINDS...ESPECIALLY DOWN THE CO RIVER MONDAY AFTERNOON. MINIMUM HUMIDITIES WILL DECREASE INTO THE TEENS AFTER MONDAY WHILE TEMPERATURES RISE TO WELL ABOVE SEASONAL NORMALS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH PREVIOUS DISCUSSION...MO AVIATION...KUHLMAN FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1124 PM MST THU FEB 6 2014 .UPDATE... ISSUED AT 1122 PM MST THU FEB 6 2014 UPDATE TO THE GRIDS TO START SNOW IN SW CO NOW GIVEN 06Z METAR REPORTS OF SNOW AT CORTEZ AND PAGOSA AND LOWERING CLOUDS AT DURANGO AND NUCLA. ANTICIPATING 1-3 INCHES OF SNOW FROM CORTEZ TO PAGOSA AS THE NEXT SHORTWAVE DISTURBANCE IN THE SOUTHERN STREAM CROSSES AZ. UPDATE ISSUED AT 831 PM MST THU FEB 6 2014 CEILINGS CONTINUE TO DROP ACROSS WESTERN COLORADO WITH SNOW BECOMING MORE WIDESPREAD AS THE EVENING WEARS ON. HAVE UPDATED ALL ZONES TO ADJUST POPS THROUGH THE REMAINDER OF THE NIGHT...IN MOST CASES INCREASING VALUES. LATEST HI-RES AND RAP MODELS ALL SUGGEST ACTIVITY WILL BE ON THE INCREASE OVERNIGHT...WITH THE SOUTHERN MOUNTAINS AND VALLEYS BECOMING A BIT MORE ACTIVE AS WE MOVE INTO FRIDAY. && .SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT) ISSUED AT 414 PM MST THU FEB 6 2014 A BREAK IN PRECIPITATION CONTINUES THIS EVENING BEFORE THE NEXT SYSTEM CURRENTLY OVER CENTRAL UTAH MAKES ITS WAY INTO THE REGION. SNOW SHOWERS WILL CONTINUE OVER THE MTNS THIS EVENING BUT WILL REALLY BEGIN TO INCREASE IN COVERAGE AND INTENSITY FRIDAY MORNING. NEW ADVISORIES OUT FOR THE SAN JUANS AND ALONG THE I-70 CORRIDOR FROM GLENWOOD SPRINGS EAST STARTING TONIGHT AND RUNNING THROUGH FRIDAY NIGHT. DOWNGRADED WARNINGS TO ADVISORIES FOR THE GRAND MESA AND NIXED THE WARNING FOR THE ROAN AND TAVAPUTS PLATEAU. VERY LITTLE FORCING IS INVOLVED WITH THIS PROGRESSIVE PATTERN OVER THE NEXT COUPLE OF DAYS WHICH HAS MADE THE FORECAST VERY DIFFICULT. WITH WARM AIR OVERRUNNING COLD AIR POOL AT THE SFC ON FRIDAY...THE CHANCE REMAINS FOR LIGHT SNOW AROUND MUCH OF THE REGION. KEPT LOW POPS IN THE GRAND VALLEY AS THE WESTERLY FLOW IS FAVORABLE WITH OVERRUNNING INVOLVED BUT WITHOUT ANY FRONTOGENETICAL FORCING...AM NOT HIGHLY CONFIDENT ON THE SCENARIO PANNING OUT DUE TO THE UNORGANIZED NATURE OF THE PATTERN AND MODELS GREATLY UNDER PERFORMING FOR TODAYS FORECAST. PWATS ARE INCREASING SLIGHTLY TONIGHT BUT REMAIN RELATIVELY LOW FRIDAY (0.2 TO 0.3)...WHICH IS WHY SNOW AMTS IN THE FORECAST HAVE DECREASED FROM THE PREVIOUS FORECAST. 700 MB FLOW WILL BEGIN TO INCREASE FRIDAY AS THE PRESSURE GRADIENT TIGHTENS...WHICH WILL CREATE BLOWING SNOW AT HIGHER ELEVATIONS STARTING FRIDAY AFTERNOON. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 414 PM MST THU FEB 6 2014 IN THE BIG PICTURE...PACIFIC MOISTURE WILL CONTINUE TO STREAM OVER THE REGION THROUGH NEXT WEEK AS THE JET STREAM REMAINS STRETCHED ACROSS THE LOWER 48 STATES. MOISTURE WILL FLUCTUATE OVER OUR FORECAST AREA AT TIMES AS THE POSITION OF THE JET SHIFTS FROM OVER THE NORTHERN TIER STATES...INTO THE DESERT SOUTHWEST AS EMBEDDED SHORTWAVES PASS. MODELS HAVE BEEN IN GOOD AGREEMENT WITH THIS GENERAL SOLUTION...BUT THE DETAILS HAVE BEEN FAR MORE PROBLEMATIC. ON SAT A 120+KT UPPER JET CORE WILL PUSH OVER THE AREA FROM THE NORTHWEST...BRINGING A DEEPER SURGE OF PACIFIC MOISTURE. WESTERLY WINDS WILL STRENGTHEN...RESULTING IN INCREASED OROGRAPHIC LIFT ESPECIALLY BY THE AFTERNOON AS SURFACE WINDS INCREASE. HOWEVER OTHER LIFTING MECHANISMS REMAIN WEAK OR NON-EXISTENT AS WARM ADVECTION CONTINUES INTO SUNDAY. SOME WEAK ISENTROPIC UPGLIDE IS HINTED AT EARLY SAT...BUT THIS IS SHORT-LIVED AND UNIMPRESSIVE. THE COLD AIR IN THE VALLEYS WILL CONTINUE TO MODIFY...SO OVERRUNNING PRECIPITATION WILL BECOME LESS LIKELY THROUGH THE DAY. THAT SAID...AS MENTIONED ABOVE...THE WESTERLY OROGRAPHICS WILL BECOME EXCELLENT. THEREFORE MOUNTAIN SNOW WILL INCREASE THROUGH THE DAY...AIDED BY SOME DIURNAL HEATING. MOISTURE WILL CONTINUE TO INCREASE THROUGH MON/MON NIGHT. ALSO WEAK COLD AIR ADVECTION WILL FINALLY DEVELOP LATE SUN AFTERNOON AS HEIGHTS LOWER. WINDS WILL HAVE DIMINISHED BY SUNDAY AS THE JET DROPS SOUTHWARD. BUT WITH AMPLE MOISTURE...AND SOME MARGINAL INSTABILITY DUE TO COOLING ALOFT...GOOD MOUNTAIN SNOWFALL WILL CONTINUE. BUT BEFORE ANY COOLING DEVELOPS SNOW LEVELS WILL RISE WITH SNOW CHANGING OVER TO RAIN...OR A RAIN/SNOW MIX IN MANY OF THE VALLEYS...EVEN IN THE FAR NORTH. A WEAK SHORTWAVE TROUGH IS THEN EXPECTED TO PASS LATE MON/MON NIGHT...KEEPING SNOW LIKELY IN THE MOUNTAINS WITH A CHANCE OF SNOW FOR THE HIGHER VALLEYS. MODELS INDICATE A DECREASE IN MOISTURE THROUGH THE REMAINDER OF THE PERIOD. HOWEVER THE ZONAL FLOW WILL PERSIST...AND WILL CONTINUE TO CARRY AT LEAST SOME PACIFIC MOISTURE OVER THE REGION. EARLY IN THE PERIOD...LOW TEMPERATURES WILL CONTINUE TO MODERATE DUE TO THE MOIST UNSETTLED FLOW. THE WARM AND UNSETTLED NATURE OF THE FLOW WILL ALSO ALLOW THE COLD VALLEYS TO APPROACH MORE NORMAL DAYTIME TEMPERATURES...WITH ABOVE NORMAL READINGS FOR THE SOUTHERN VALLEYS. THROUGH THE REMAINDER OF THE PERIOD...TEMPS WILL CONTINUE TO BE GREATLY INFLUENCED BY THE AMOUNT OF CLOUDS/PRECIPITATION EACH PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 950 PM MST THU FEB 6 2014 MOIST WESTERLY FLOW AND A SERIES OF EMBEDDED DISTURBANCES WILL BRING OCCASIONAL SNOW AND FREQUENT MOUNTAIN OBSCURATIONS TO THE REGION THROUGH FRIDAY NIGHT. KGJT/KMTJ/KDRO/KCNY SHOULD SEE SOME IMPROVEMENT AFTER 19Z FRI. TEMPERATURES MAY BE WARM ENOUGH FOR RAIN OR A RAIN/SNOW MIX AT KGJT/KCNY FRIDAY AFTERNOON. LITTLE CHANGE IN THE PATTERN IS EXPECTED THROUGH THE WEEKEND. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL 4 PM MST SATURDAY COZ009. WINTER STORM WARNING UNTIL 6 PM MST SATURDAY COZ004-010-012-013. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST FRIDAY NIGHT COZ018-019. WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 AM MST SATURDAY COZ008. UT...NONE. && $$ UPDATE...JAD SHORT TERM...JAM LONG TERM...EH AVIATION...JAD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
950 PM MST THU FEB 6 2014 UPDATED AVIATION SECTION .UPDATE... ISSUED AT 831 PM MST THU FEB 6 2014 CEILINGS CONTINUE TO DROP ACROSS WESTERN COLORADO WITH SNOW BECOMING MORE WIDESPREAD AS THE EVENING WEARS ON. HAVE UPDATED ALL ZONES TO ADJUST POPS THROUGH THE REMAINDER OF THE NIGHT...IN MOST CASES INCREASING VALUES. LATEST HI-RES AND RAP MODELS ALL SUGGEST ACTIVITY WILL BE ON THE INCREASE OVERNIGHT...WITH THE SOUTHERN MOUNTAINS AND VALLEYS BECOMING A BIT MORE ACTIVE AS WE MOVE INTO FRIDAY. && .SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT) ISSUED AT 414 PM MST THU FEB 6 2014 A BREAK IN PRECIPITATION CONTINUES THIS EVENING BEFORE THE NEXT SYSTEM CURRENTLY OVER CENTRAL UTAH MAKES ITS WAY INTO THE REGION. SNOW SHOWERS WILL CONTINUE OVER THE MTNS THIS EVENING BUT WILL REALLY BEGIN TO INCREASE IN COVERAGE AND INTENSITY FRIDAY MORNING. NEW ADVISORIES OUT FOR THE SAN JUANS AND ALONG THE I-70 CORRIDOR FROM GLENWOOD SPRINGS EAST STARTING TONIGHT AND RUNNING THROUGH FRIDAY NIGHT. DOWNGRADED WARNINGS TO ADVISORIES FOR THE GRAND MESA AND NIXED THE WARNING FOR THE ROAN AND TAVAPUTS PLATEAU. VERY LITTLE FORCING IS INVOLVED WITH THIS PROGRESSIVE PATTERN OVER THE NEXT COUPLE OF DAYS WHICH HAS MADE THE FORECAST VERY DIFFICULT. WITH WARM AIR OVERRUNNING COLD AIR POOL AT THE SFC ON FRIDAY...THE CHANCE REMAINS FOR LIGHT SNOW AROUND MUCH OF THE REGION. KEPT LOW POPS IN THE GRAND VALLEY AS THE WESTERLY FLOW IS FAVORABLE WITH OVERRUNNING INVOLVED BUT WITHOUT ANY FRONTOGENETICAL FORCING...AM NOT HIGHLY CONFIDENT ON THE SCENARIO PANNING OUT DUE TO THE UNORGANIZED NATURE OF THE PATTERN AND MODELS GREATLY UNDER PERFORMING FOR TODAYS FORECAST. PWATS ARE INCREASING SLIGHTLY TONIGHT BUT REMAIN RELATIVELY LOW FRIDAY (0.2 TO 0.3)...WHICH IS WHY SNOW AMTS IN THE FORECAST HAVE DECREASED FROM THE PREVIOUS FORECAST. 700 MB FLOW WILL BEGIN TO INCREASE FRIDAY AS THE PRESSURE GRADIENT TIGHTENS...WHICH WILL CREATE BLOWING SNOW AT HIGHER ELEVATIONS STARTING FRIDAY AFTERNOON. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 414 PM MST THU FEB 6 2014 IN THE BIG PICTURE...PACIFIC MOISTURE WILL CONTINUE TO STREAM OVER THE REGION THROUGH NEXT WEEK AS THE JET STREAM REMAINS STRETCHED ACROSS THE LOWER 48 STATES. MOISTURE WILL FLUCTUATE OVER OUR FORECAST AREA AT TIMES AS THE POSITION OF THE JET SHIFTS FROM OVER THE NORTHERN TIER STATES...INTO THE DESERT SOUTHWEST AS EMBEDDED SHORTWAVES PASS. MODELS HAVE BEEN IN GOOD AGREEMENT WITH THIS GENERAL SOLUTION...BUT THE DETAILS HAVE BEEN FAR MORE PROBLEMATIC. ON SAT A 120+KT UPPER JET CORE WILL PUSH OVER THE AREA FROM THE NORTHWEST...BRINGING A DEEPER SURGE OF PACIFIC MOISTURE. WESTERLY WINDS WILL STRENGTHEN...RESULTING IN INCREASED OROGRAPHIC LIFT ESPECIALLY BY THE AFTERNOON AS SURFACE WINDS INCREASE. HOWEVER OTHER LIFTING MECHANISMS REMAIN WEAK OR NON-EXISTENT AS WARM ADVECTION CONTINUES INTO SUNDAY. SOME WEAK ISENTROPIC UPGLIDE IS HINTED AT EARLY SAT...BUT THIS IS SHORT-LIVED AND UNIMPRESSIVE. THE COLD AIR IN THE VALLEYS WILL CONTINUE TO MODIFY...SO OVERRUNNING PRECIPITATION WILL BECOME LESS LIKELY THROUGH THE DAY. THAT SAID...AS MENTIONED ABOVE...THE WESTERLY OROGRAPHICS WILL BECOME EXCELLENT. THEREFORE MOUNTAIN SNOW WILL INCREASE THROUGH THE DAY...AIDED BY SOME DIURNAL HEATING. MOISTURE WILL CONTINUE TO INCREASE THROUGH MON/MON NIGHT. ALSO WEAK COLD AIR ADVECTION WILL FINALLY DEVELOP LATE SUN AFTERNOON AS HEIGHTS LOWER. WINDS WILL HAVE DIMINISHED BY SUNDAY AS THE JET DROPS SOUTHWARD. BUT WITH AMPLE MOISTURE...AND SOME MARGINAL INSTABILITY DUE TO COOLING ALOFT...GOOD MOUNTAIN SNOWFALL WILL CONTINUE. BUT BEFORE ANY COOLING DEVELOPS SNOW LEVELS WILL RISE WITH SNOW CHANGING OVER TO RAIN...OR A RAIN/SNOW MIX IN MANY OF THE VALLEYS...EVEN IN THE FAR NORTH. A WEAK SHORTWAVE TROUGH IS THEN EXPECTED TO PASS LATE MON/MON NIGHT...KEEPING SNOW LIKELY IN THE MOUNTAINS WITH A CHANCE OF SNOW FOR THE HIGHER VALLEYS. MODELS INDICATE A DECREASE IN MOISTURE THROUGH THE REMAINDER OF THE PERIOD. HOWEVER THE ZONAL FLOW WILL PERSIST...AND WILL CONTINUE TO CARRY AT LEAST SOME PACIFIC MOISTURE OVER THE REGION. EARLY IN THE PERIOD...LOW TEMPERATURES WILL CONTINUE TO MODERATE DUE TO THE MOIST UNSETTLED FLOW. THE WARM AND UNSETTLED NATURE OF THE FLOW WILL ALSO ALLOW THE COLD VALLEYS TO APPROACH MORE NORMAL DAYTIME TEMPERATURES...WITH ABOVE NORMAL READINGS FOR THE SOUTHERN VALLEYS. THROUGH THE REMAINDER OF THE PERIOD...TEMPS WILL CONTINUE TO BE GREATLY INFLUENCED BY THE AMOUNT OF CLOUDS/PRECIPITATION EACH PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 950 PM MST THU FEB 6 2014 MOIST WESTERLY FLOW AND A SERIES OF EMBEDDED DISTURBANCES WILL BRING OCCASIONAL SNOW AND FREQUENT MOUNTAIN OBSCURATIONS TO THE REGION THROUGH FRIDAY NIGHT. KGJT/KMTJ/KDRO/KCNY SHOULD SEE SOME IMPROVEMENT AFTER 19Z FRI. TEMPERATURES MAY BE WARM ENOUGH FOR RAIN OR A RAIN/SNOW MIX AT KGJT/KCNY FRIDAY AFTERNOON. LITTLE CHANGE IN THE PATTERN IS EXPECTED THROUGH THE WEEKEND. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL 4 PM MST SATURDAY COZ009. WINTER STORM WARNING UNTIL 6 PM MST SATURDAY COZ004-010-012-013. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST FRIDAY NIGHT COZ018-019. WINTER WEATHER ADVISORY FROM 6 AM FRIDAY TO 6 AM MST SATURDAY COZ008. UT...NONE. && $$ UPDATE...JDC SHORT TERM...JAM LONG TERM...EH AVIATION...JAD
AREA FORECAST DISCUSSION
NWS ALBANY NY
106 PM EST FRI FEB 7 2014 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH SATURDAY. IT WILL BE COLD WITH MAINLY DRY WEATHER...SOME LAKE EFFECT SNOW SHOWERS WILL OCCUR INTO THE WESTERN ADIRONDACKS. A SERIES OF COLD FRONTS WILL CROSS THE REGION SUNDAY AND MONDAY WITH SOME LIGHT SNOWFALL. HIGH PRESSURE WILL BUILD BACK INTO THE NORTHEAST TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF NOON EST...AMPLE CLEAR SKIES ACROSS MOST OF THE REGION WITH SOME LAKE EFFECT CLOUDS AND LIGHT SNOW SHOWERS/FLURRIES IMPACTING PORTIONS OF NORTHERN HERKIMER COUNTY. KTYX RADAR REFLECTIVITIES ARE VERY LIGHT AND HAVE REDUCED THE MENTION OF SNOW SHOWERS ACROSS NORTHERN HERKIMER COUNTY. IN ADDITION...WITH THE VISIBLE SATELLITE...CONSIDERABLE ICE COVER OVER LAKE ONTARIO WHICH TOO WILL HAVE LIMITS ON LAKE EFFECT POTENTIAL. A SHORT WAVE SEEN IN THE H2O VAPOR LOOP WAS MOVING ACROSS LAKE ERIE. THIS WAVE WILL QUICKLY MOVE ACROSS OUR REGION DURING THE AFTERNOON. LIMITED MOISTURE ACCOMPANIES THIS FEATURE...HOWEVER...CLOUDS SHOULD INCREASE FROM WEST TO EAST AND HAVE ACCOUNTED FOR THIS IN THE NEW ESTF SKY GRID FORECAST. OTHERWISE...TEMPS LOOK GREAT WITH MINOR HOURLY ADJUSTMENTS. PREV DISC... AN UPPER LEVEL DISTURBANCE EMBEDDED WITHIN MAINLY ZONAL FLOW ALOFT IS IN THE PROCESS OF MOVING ACROSS UPSTATE NY. THIS NORTHERN STREAM FEATURE IS RATHER MOISTURE STARVED...AND IS DOING LITTLE SYNOPTICALLY OTHER THAN PRODUCING SOME A BATCH OF CLOUDS AND SOME FLURRIES AS IT PASSES. MEANWHILE...THE PERSISTENT W-SW FLOW IN THE LOW AND MID LEVELS AHEAD OF THIS DISTURBANCE IS ALLOWING FOR A BAND OF LAKE EFFECT SNOW OFF LAKE ONTARIO. DESPITE LOW INVERSION HEIGHTS AND THE LACK OF A MULTI-LAKE CONNECTION...THE LONG FETCH ACROSS LAKE ONTARIO IS ALLOWING FOR SOME MODERATE TO HEAVY SNOW WITHIN THIS BAND...AND AN INLAND EXTENT REACHING INTO THE NORTHWESTERN ADIRONDACKS. HOWEVER...THE ORIENTATION OF THE BAND IS KEEPING THE HEAVIEST ECHOES TO THE WEST AND NORTH OF OUR AREA. OVER THE NEXT FEW HOURS...THIS BAND WILL SLOWLY START TO WEAKEN AND DRIFT SOUTH...IMPACTING THE FAR NORTHWESTERN CORNER OF OUR CWA...WHICH IS MOSTLY UNINHABITED FOREST PRESERVE OF THE ADIRONDACKS. THE APPROACHING UPPER LEVEL DISTURBANCE WILL DISRUPT THE FLOW ENOUGH BY THE LATE MORNING HOURS TO SIGNIFICANTLY DECREASE THE INTENSITY AND EXTENT OF THIS BAND. BEFORE THAT OCCURS...AN INCH OR TWO OF ACCUMULATION IS POSSIBLE ACROSS FAR NORTHERN PORTIONS OF HERKIMER COUNTY. THIS MOVEMENT AND WEAKENING IS SHOWN IN THE 09Z 3KM HRRR COMPOSITE REFLECTIVITY FORECAST PRODUCT...AS WELL AS THE 06Z RUN OF OUR LOCAL HIRESWRF. BY THE AFTN...WE WILL DECREASE POPS ACROSS THE REGION...WITH THE BEST SNOW BY THAT POINT LIMITED TO AREAS NEAR THE LAKE SHORE OF LAKE ONTARIO. OTHERWISE...IT WILL REMAIN MAINLY DRY OVER THE REMAINDER OF THE REGION TODAY...WITH JUST SOME PASSING CLOUDS. CAN/T TOTALLY RULE OUT A FEW FLURRIES WITH THE PASSING UPPER LEVEL DISTURBANCE FOR WESTERN PARTS OF THE AREA THIS MORNING /BASED ON CURRENT UPSTREAMS OBS IN CENTRAL NY/...BUT NO MEASURABLE SNOW ACCUMULATION IS EXPECTED. WINDS WILL PICK UP DURING THE AFTERNOON HOURS AS THE SHORTWAVE MOVES ACROSS THE REGION...WITH SOME GUSTS IN THE 10-20 MPH RANGE...ESP IN AREAS OF CHANNELED FLOW. SOME SHELTERED AREAS THAT HAD NO WIND AND HAD MAINLY CLEAR SKIES GOT VERY COLD THIS MORNING...SUCH AS IN THE GLENS FALLS AREA...WHERE IT DROPPED AS LOW AS -13 DEGREES. ELSEWHERE...TEMPS WERE NEAR ZERO OR IN THE SINGLE DIGITS. ONCE THE SUN COMES UP...TEMPS WILL STEADILY WARM UP THROUGH THE DAY. MAX TEMPS WILL STILL BE BELOW NORMAL...WITH LOW TO MID 20S FOR VALLEY AREAS /TEENS IN THE HIGH TERRAIN/. TONIGHT...SKIES WILL CLEAR OUT AS THE THE DISTURBANCE MOVES EAST OF THE REGION. THERE STILL MAY BE A BREEZE IN THE EVENING...BUT WINDS SHOULD START TO BECOME LIGHT BY AFTER MIDNIGHT. WITH THE CLEARING SKIES AND FRESH SNOW PACK IN PLACE...HAVE GONE COOLER THAN MOS GUIDANCE FOR MIN TEMPS...WITH SINGLE DIGITS FOR MOST AREAS. SOME BELOW ZERO READINGS WILL OCCUR IN THE ADIRONDACKS...GLENS FALLS AREA...AND SOUTHERN VT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... GENERAL MODEL SUITE AGREEMENT DURING THIS PERIOD AMONG THE GFS/NAM/GEM/ WITH THE GEM/12UTC ECMWF BEING DRIER WITH VERY LITTLE QPF. AT 500HPA MUCH OF THE EASTERN USA IS IN FAST W-NW FLOW WITH SHORT WVS RACING ACROSS RGN. INITIALLY WEAK SFC HIGH PRESSURE IS OVER RGN. AIR MASS OVER RGN IS MOISTURE STARVED. AT SFC A SERIES OF CDFNTS MOVE THROUGH DURING THE PERIOD. THE FIRST SAT NT INTO SUN RESULTS IN INCRG CLOUDS AND SOME -SN AND ENHANCED LAKE EFFECT -SNSH INTO TUG HILL. BUT NOT MUCH IN THE WAY OF ACCUMULATION. ANOTHER CDFNT 500HPA SHORT WV PAIR DROP SLOWLY SOUTH THROUGH RGN MONDAY. AGAIN NOT MUCH MORE THAN -SHSN WITH MAYBE A MODEST ENHANCEMENT BY LK ONTARIO AS IT MOVES THROUGH ON 290-300 VECTORS. HIGH PRESSURE BUILDS S IN ITS WAKE INTO RGN MONDAY NIGHT. OVERALL TEMPS DURING THIS PERIOD WILL BE 5-10 DEG BLO NORMALS. && .LONG TERM /TUESDAY THROUGH THURSDAY/... DURING THIS PERIOD FAST 500HPA FLOW SHIFTS FM NW TO W THEN SW AS SHRTS WV DIG A TROF OVER THE E USA THU. AT SFC HIGH PRESSURE WILL REMAIN IN PLACE THROUGH WED AND SLIDES OFFSHORE WED NT. THE FIRST TWO DAYS ALL THE GUIDANCE (GFS/ECMWF/HPC)IS IN AGREEMENT. THURSDAY AGREEMENT GOES OUT THE WINDOW AS DIVERGE REIGNS. TUES THE LAST 500HPA SHORT WV IN THE NW FLOW PASSES ACROSS RGN WITH GFS MAINLY FAIR AND ECMWF SUG MORE CLOUDINESS AND SCT -SHSN. HIGH PRESSURE LINGERS AT THE SFC INTO WED EVNG. STILL A TRANQUIL MAINLY DRY PERIOD THROUGH WED NT. THU WHILE ALL THE MDLS CARVE OUT OR BRING A SIGNIFICANT 500HPA TROF INTO THE NORTHEAST. WHAT HAPPENS AT THE SFC IS VERY DIFFERENT BTWN THEM. OPERATIONAL GFS/GEM KEEP N BRANCH AND S BRANCH DYNAMICS SEPARATE. GEM PASSES CSTL LOW WELL S OF RGN AND OUT TO SEA. THE GFS DEVELOPS COASTAL LOW WELL OFF SHORE...OVER AND EAST OF GULF STREAM...WITH AND ONLY THE 500HPA SHORT WV AND ITS MODEST CLIPPER IMPACTING THE RGN WITH SOME -SHSN MUCH LIKE THE SYSTEMS WE`VE BEEN HAVING MOST OF THE WEEK. HWVR THE OPERATIONAL RUN OF THE GFS IS AMONG THE 10 OR SO IN ITS OWN ENSEMBLE THAT LEAN TWRD THIS SCENARIO. ITS OTHER 10 MEMBERS HAVE 0.4 TO 1.4 IN QPF MUCH LIKE THE ECMWF DESCRIBED BLO. THE ECMWF DEVELOPS THE CSTL LOW OVER THE VA CAPES WED NT...AND SENDS IT NE TWRD BOS THU NT...RIGHT INSIDE THE BENCHMARK...AND IMPLYING A SIGNIFICANT SNOW EVENT FOR THE FCA WITH 0.50-0.60 QPF ACROSS FCA. OVERNIGHT HPC GUID ALSO LEANS TWRD ECMWF SOLTN...BUT NOT TOTALLY. THE MDL DIFFERENCES SEEM TIED AS USUAL TO HOW AND WHERE THE RESPECTIVE MODELS PHASE VARIOUS 500HPA SHORT WVS INTO THE EASTERN TROF ON THU. WHILE THERE REMAINS MUCH UNCERTAINTY AS TO THE EVENT 6 DAYS OUT...THERE`S AN INCREASING SIGNAL IN THE GUID AT THIS POINT. TEMPS WILL BEGIN THIS PERIOD WELL BLOW NORMALS AND END NR TO SLIGHTLY ABV NORMALS. AS SUCH WILL POPULATE WITH HPC ATTM. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD...18Z/SATURDAY. HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST AT THE SURFACE. ALOFT...ANOTHER SHORT WAVE TROUGH WILL APPROACH AND PASS OVER THE REGION TONIGHT BRINGING ANOTHER BATCH OF CLOUDS. HIGH LEVEL CIRRUS CLOUDS WILL OVERSPREAD FROM THE SOUTHWEST ON SATURDAY. SOUTH TO WEST WINDS WILL BE STRONGEST AT KPSF WITH SOME GUSTS INTO THE TEENS THIS AFTERNOON. THE WINDS WILL WEAKEN TONIGHT WITH WESTERLY WINDS ON SATURDAY. OUTLOOK... SAT NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SN. SUN: MODERATE OPERATIONAL IMPACT. CHANCE OF SN. SUN NIGHT-MON: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SN. MON NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT WEEK AS IT WILL BE DRY OR ANY PRECIPITATION THAT FALLS WILL BE SNOW. EXPECTING DRY CONDITIONS EXPECTED THROUGH SATURDAY...EXCEPT FOR SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. THERE IS A CHANCE FOR MAINLY LIGHT SNOWFALL ACROSS THE REGION SATURDAY NIGHT INTO MONDAY. A STORM MAY MOVE UP THE EAST COAST THURSDAY WITH THE POTENTIAL FOR SNOWFALL. ITS TRACK REMAINS HIGHLY UNCERTAIN AT THIS TIME. WITH TEMPERATURES EXPECTED TO BE BELOW NORMAL FOR THE NEXT SEVERAL DAYS...ICE WILL THICKEN 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. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...IAA/SNYDER NEAR TERM...IAA/FRUGIS/BGM SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...IAA HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
1231 PM EST FRI FEB 7 2014 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH SATURDAY. IT WILL BE COLD WITH MAINLY DRY WEATHER...SOME LAKE EFFECT SNOW SHOWERS WILL OCCUR INTO THE WESTERN ADIRONDACKS. A SERIES OF COLD FRONTS WILL CROSS THE REGION SUNDAY AND MONDAY WITH SOME LIGHT SNOWFALL. HIGH PRESSURE WILL BUILD BACK INTO THE NORTHEAST TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF NOON EST...AMPLE CLEAR SKIES ACROSS MOST OF THE REGION WITH SOME LAKE EFFECT CLOUDS AND LIGHT SNOW SHOWERS/FLURRIES IMPACTING PORTIONS OF NORTHERN HERKIMER COUNTY. KTYX RADAR REFLECTIVITIES ARE VERY LIGHT AND HAVE REDUCED THE MENTION OF SNOW SHOWERS ACROSS NORTHERN HERKIMER COUNTY. IN ADDITION...WITH THE VISIBLE SATELLITE...CONSIDERABLE ICE COVER OVER LAKE ONTARIO WHICH TOO WILL HAVE LIMITS ON LAKE EFFECT POTENTIAL. A SHORT WAVE SEEN IN THE H2O VAPOR LOOP WAS MOVING ACROSS LAKE ERIE. THIS WAVE WILL QUICKLY MOVE ACROSS OUR REGION DURING THE AFTERNOON. LIMITED MOISTURE ACCOMPANIES THIS FEATURE...HOWEVER...CLOUDS SHOULD INCREASE FROM WEST TO EAST AND HAVE ACCOUNTED FOR THIS IN THE NEW ESTF SKY GRID FORECAST. OTHERWISE...TEMPS LOOK GREAT WITH MINOR HOURLY ADJUSTMENTS. PREV DISC... AN UPPER LEVEL DISTURBANCE EMBEDDED WITHIN MAINLY ZONAL FLOW ALOFT IS IN THE PROCESS OF MOVING ACROSS UPSTATE NY. THIS NORTHERN STREAM FEATURE IS RATHER MOISTURE STARVED...AND IS DOING LITTLE SYNOPTICALLY OTHER THAN PRODUCING SOME A BATCH OF CLOUDS AND SOME FLURRIES AS IT PASSES. MEANWHILE...THE PERSISTENT W-SW FLOW IN THE LOW AND MID LEVELS AHEAD OF THIS DISTURBANCE IS ALLOWING FOR A BAND OF LAKE EFFECT SNOW OFF LAKE ONTARIO. DESPITE LOW INVERSION HEIGHTS AND THE LACK OF A MULTI-LAKE CONNECTION...THE LONG FETCH ACROSS LAKE ONTARIO IS ALLOWING FOR SOME MODERATE TO HEAVY SNOW WITHIN THIS BAND...AND AN INLAND EXTENT REACHING INTO THE NORTHWESTERN ADIRONDACKS. HOWEVER...THE ORIENTATION OF THE BAND IS KEEPING THE HEAVIEST ECHOES TO THE WEST AND NORTH OF OUR AREA. OVER THE NEXT FEW HOURS...THIS BAND WILL SLOWLY START TO WEAKEN AND DRIFT SOUTH...IMPACTING THE FAR NORTHWESTERN CORNER OF OUR CWA...WHICH IS MOSTLY UNINHABITED FOREST PRESERVE OF THE ADIRONDACKS. THE APPROACHING UPPER LEVEL DISTURBANCE WILL DISRUPT THE FLOW ENOUGH BY THE LATE MORNING HOURS TO SIGNIFICANTLY DECREASE THE INTENSITY AND EXTENT OF THIS BAND. BEFORE THAT OCCURS...AN INCH OR TWO OF ACCUMULATION IS POSSIBLE ACROSS FAR NORTHERN PORTIONS OF HERKIMER COUNTY. THIS MOVEMENT AND WEAKENING IS SHOWN IN THE 09Z 3KM HRRR COMPOSITE REFLECTIVITY FORECAST PRODUCT...AS WELL AS THE 06Z RUN OF OUR LOCAL HIRESWRF. BY THE AFTN...WE WILL DECREASE POPS ACROSS THE REGION...WITH THE BEST SNOW BY THAT POINT LIMITED TO AREAS NEAR THE LAKE SHORE OF LAKE ONTARIO. OTHERWISE...IT WILL REMAIN MAINLY DRY OVER THE REMAINDER OF THE REGION TODAY...WITH JUST SOME PASSING CLOUDS. CAN/T TOTALLY RULE OUT A FEW FLURRIES WITH THE PASSING UPPER LEVEL DISTURBANCE FOR WESTERN PARTS OF THE AREA THIS MORNING /BASED ON CURRENT UPSTREAMS OBS IN CENTRAL NY/...BUT NO MEASURABLE SNOW ACCUMULATION IS EXPECTED. WINDS WILL PICK UP DURING THE AFTERNOON HOURS AS THE SHORTWAVE MOVES ACROSS THE REGION...WITH SOME GUSTS IN THE 10-20 MPH RANGE...ESP IN AREAS OF CHANNELED FLOW. SOME SHELTERED AREAS THAT HAD NO WIND AND HAD MAINLY CLEAR SKIES GOT VERY COLD THIS MORNING...SUCH AS IN THE GLENS FALLS AREA...WHERE IT DROPPED AS LOW AS -13 DEGREES. ELSEWHERE...TEMPS WERE NEAR ZERO OR IN THE SINGLE DIGITS. ONCE THE SUN COMES UP...TEMPS WILL STEADILY WARM UP THROUGH THE DAY. MAX TEMPS WILL STILL BE BELOW NORMAL...WITH LOW TO MID 20S FOR VALLEY AREAS /TEENS IN THE HIGH TERRAIN/. TONIGHT...SKIES WILL CLEAR OUT AS THE THE DISTURBANCE MOVES EAST OF THE REGION. THERE STILL MAY BE A BREEZE IN THE EVENING...BUT WINDS SHOULD START TO BECOME LIGHT BY AFTER MIDNIGHT. WITH THE CLEARING SKIES AND FRESH SNOW PACK IN PLACE...HAVE GONE COOLER THAN MOS GUIDANCE FOR MIN TEMPS...WITH SINGLE DIGITS FOR MOST AREAS. SOME BELOW ZERO READINGS WILL OCCUR IN THE ADIRONDACKS...GLENS FALLS AREA...AND SOUTHERN VT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... GENERAL MODEL SUITE AGREEMENT DURING THIS PERIOD AMONG THE GFS/NAM/GEM/ WITH THE GEM/12UTC ECMWF BEING DRIER WITH VERY LITTLE QPF. AT 500HPA MUCH OF THE EASTERN USA IS IN FAST W-NW FLOW WITH SHORT WVS RACING ACROSS RGN. INITIALLY WEAK SFC HIGH PRESSURE IS OVER RGN. AIR MASS OVER RGN IS MOISTURE STARVED. AT SFC A SERIES OF CDFNTS MOVE THROUGH DURING THE PERIOD. THE FIRST SAT NT INTO SUN RESULTS IN INCRG CLOUDS AND SOME -SN AND ENHANCED LAKE EFFECT -SNSH INTO TUG HILL. BUT NOT MUCH IN THE WAY OF ACCUMULATION. ANOTHER CDFNT 500HPA SHORT WV PAIR DROP SLOWLY SOUTH THROUGH RGN MONDAY. AGAIN NOT MUCH MORE THAN -SHSN WITH MAYBE A MODEST ENHANCEMENT BY LK ONTARIO AS IT MOVES THROUGH ON 290-300 VECTORS. HIGH PRESSURE BUILDS S IN ITS WAKE INTO RGN MONDAY NIGHT. OVERALL TEMPS DURING THIS PERIOD WILL BE 5-10 DEG BLO NORMALS. && .LONG TERM /TUESDAY THROUGH FRIDAY/... DURING THIS PERIOD FAST 500HPA FLOW SHIFTS FM NW TO W THEN SW AS SHRTS WV DIG A TROF OVER THE E USA THU. AT SFC HIGH PRESSURE WILL REMAIN IN PLACE THROUGH WED AND SLIDES OFFSHORE WED NT. THE FIRST TWO DAYS ALL THE GUIDANCE (GFS/ECMWF/HPC)IS IN AGREEMENT. THURSDAY AGREEMENT GOES OUT THE WINDOW AS DIVERGE REIGNS. TUES THE LAST 500HPA SHORT WV IN THE NW FLOW PASSES ACROSS RGN WITH GFS MAINLY FAIR AND ECMWF SUG MORE CLOUDINESS AND SCT -SHSN. HIGH PRESSURE LINGERS AT THE SFC INTO WED EVNG. STILL A TRANQUIL MAINLY DRY PERIOD THROUGH WED NT. THU WHILE ALL THE MDLS CARVE OUT OR BRING A SIGNIFICANT 500HPA TROF INTO THE NORTHEAST. WHAT HAPPENS AT THE SFC IS VERY DIFFERENT BTWN THEM. OPERATIONAL GFS/GEM KEEP N BRANCH AND S BRANCH DYNAMICS SEPARATE. GEM PASSES CSTL LOW WELL S OF RGN AND OUT TO SEA. THE GFS DEVELOPS COASTAL LOW WELL OFF SHORE...OVER AND EAST OF GULF STREAM...WITH AND ONLY THE 500HPA SHORT WV AND ITS MODEST CLIPPER IMPACTING THE RGN WITH SOME -SHSN MUCH LIKE THE SYSTEMS WE`VE BEEN HAVING MOST OF THE WEEK. HWVR THE OPERATIONAL RUN OF THE GFS IS AMONG THE 10 OR SO IN ITS OWN ENSEMBLE THAT LEAN TWRD THIS SCENARIO. ITS OTHER 10 MEMBERS HAVE 0.4 TO 1.4 IN QPF MUCH LIKE THE ECMWF DESCRIBED BLO. THE ECMWF DEVELOPS THE CSTL LOW OVER THE VA CAPES WED NT...AND SENDS IT NE TWRD BOS THU NT...RIGHT INSIDE THE BENCHMARK...AND IMPLYING A SIGNIFICANT SNOW EVENT FOR THE FCA WITH 0.50-0.60 QPF ACROSS FCA. OVERNIGHT HPC GUID ALSO LEANS TWRD ECMWF SOLTN...BUT NOT TOTALLY. THE MDL DIFFERENCES SEEM TIED AS USUAL TO HOW AND WHERE THE RESPECTIVE MODELS PHASE VARIOUS 500HPA SHORT WVS INTO THE EASTERN TROF ON THU. WHILE THERE REMAINS MUCH UNCERTAINTY AS TO THE EVENT 6 DAYS OUT...THERE`S AN INCREASING SIGNAL IN THE GUID AT THIS POINT. TEMPS WILL BEGIN THIS PERIOD WELL BLOW NORMALS AND END NR TO SLIGHTLY ABV NORMALS. AS SUCH WILL POPULATE WITH HPC ATTM. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THE DAY TODAY AND INTO TONIGHT. SCT-BKN STRATOCU AND MID LEVEL CLOUDS WILL MOVE IN THROUGH THE MORNING HOURS AND CONTINUE INTO THE AFTERNOON THANKS TO A PASSING UPPER LEVEL DISTURBANCE MOVING ACROSS THE REGION. LITTLE MOISTURE IS ASSOCIATED WITH THIS FEATURE...SO ONLY SOME FLURRIES ARE EXPECTED. LIGHT WINDS WILL BECOME WESTERLY BY AROUND 5-10 KTS THIS MORNING. THERE MAY BE A FEW HIGHER GUSTS AT KALB/KPSF. WINDS WILL DIMINISH DURING THE EVENING...AND CLOUDS WILL BEGIN TO DECREASE AS THE DISTURBANCE MOVES EASTWARD. MOST SITES LOOK TO BE NEARLY CLEAR BY THE LATE EVENING HOURS AND THIS WILL CONTINUE THROUGH THE ENTIRE OVERNIGHT. OUTLOOK... SATURDAY NIGHT/SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. SUNDAY NIGHT/MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. MONDAY NIGHT TO WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT WEEK AS IT WILL BE DRY OR ANY PRECIPITATION THAT FALLS WILL BE SNOW. EXPECTING DRY CONDITIONS EXPECTED THROUGH SATURDAY...EXCEPT FOR SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. THERE IS A CHANCE FOR MAINLY LIGHT SNOWFALL ACROSS THE REGION SATURDAY NIGHT INTO MONDAY. A STORM MAY MOVE UP THE EAST COAST THURSDAY WITH THE POTENTIAL FOR SNOWFALL. ITS TRACK REMAINS HIGHLY UNCERTAIN AT THIS TIME. WITH TEMPERATURES EXPECTED TO BE BELOW NORMAL FOR THE NEXT SEVERAL DAYS...ICE WILL THICKEN 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. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...IAA/SNYDER NEAR TERM...IAA/FRUGIS/BGM SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...IAA/FRUGIS HYDROLOGY...SNYDER FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
827 AM EST FRI FEB 7 2014 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH SATURDAY. IT WILL BE COLD WITH MAINLY DRY WEATHER...SOME LAKE EFFECT SNOW SHOWERS WILL OCCUR INTO THE WESTERN ADIRONDACKS. A SERIES OF COLD FRONTS WILL CROSS THE REGION SUNDAY AND MONDAY WITH SOME LIGHT SNOWFALL. HIGH PRESSURE WILL BUILD BACK INTO THE NORTHEAST TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AN UPPER LEVEL DISTURBANCE EMBEDDED WITHIN MAINLY ZONAL FLOW ALOFT IS IN THE PROCESS OF MOVING ACROSS UPSTATE NY. THIS NORTHERN STREAM FEATURE IS RATHER MOISTURE STARVED...AND IS DOING LITTLE SYNOPTICALLY OTHER THAN PRODUCING SOME A BATCH OF CLOUDS AND SOME FLURRIES AS IT PASSES. MEANWHILE...THE PERSISTENT W-SW FLOW IN THE LOW AND MID LEVELS AHEAD OF THIS DISTURBANCE IS ALLOWING FOR A BAND OF LAKE EFFECT SNOW OFF LAKE ONTARIO. DESPITE LOW INVERSION HEIGHTS AND THE LACK OF A MULTI-LAKE CONNECTION...THE LONG FETCH ACROSS LAKE ONTARIO IS ALLOWING FOR SOME MODERATE TO HEAVY SNOW WITHIN THIS BAND...AND AN INLAND EXTENT REACHING INTO THE NORTHWESTERN ADIRONDACKS. HOWEVER...THE ORIENTATION OF THE BAND IS KEEPING THE HEAVIEST ECHOES TO THE WEST AND NORTH OF OUR AREA. OVER THE NEXT FEW HOURS...THIS BAND WILL SLOWLY START TO WEAKEN AND DRIFT SOUTH...IMPACTING THE FAR NORTHWESTERN CORNER OF OUR CWA...WHICH IS MOSTLY UNINHABITED FOREST PRESERVE OF THE ADIRONDACKS. THE APPROACHING UPPER LEVEL DISTURBANCE WILL DISRUPT THE FLOW ENOUGH BY THE LATE MORNING HOURS TO SIGNIFICANTLY DECREASE THE INTENSITY AND EXTENT OF THIS BAND. BEFORE THAT OCCURS...AN INCH OR TWO OF ACCUMULATION IS POSSIBLE ACROSS FAR NORTHERN PORTIONS OF HERKIMER COUNTY. THIS MOVEMENT AND WEAKENING IS SHOWN IN THE 09Z 3KM HRRR COMPOSITE REFLECTIVITY FORECAST PRODUCT...AS WELL AS THE 06Z RUN OF OUR LOCAL HIRESWRF. BY THE AFTN...WE WILL DECREASE POPS ACROSS THE REGION...WITH THE BEST SNOW BY THAT POINT LIMITED TO AREAS NEAR THE LAKE SHORE OF LAKE ONTARIO. OTHERWISE...IT WILL REMAIN MAINLY DRY OVER THE REMAINDER OF THE REGION TODAY...WITH JUST SOME PASSING CLOUDS. CAN/T TOTALLY RULE OUT A FEW FLURRIES WITH THE PASSING UPPER LEVEL DISTURBANCE FOR WESTERN PARTS OF THE AREA THIS MORNING /BASED ON CURRENT UPSTREAMS OBS IN CENTRAL NY/...BUT NO MEASURABLE SNOW ACCUMULATION IS EXPECTED. WINDS WILL PICK UP DURING THE AFTERNOON HOURS AS THE SHORTWAVE MOVES ACROSS THE REGION...WITH SOME GUSTS IN THE 10-20 MPH RANGE...ESP IN AREAS OF CHANNELED FLOW. SOME SHELTERED AREAS THAT HAD NO WIND AND HAD MAINLY CLEAR SKIES GOT VERY COLD THIS MORNING...SUCH AS IN THE GLENS FALLS AREA...WHERE IT DROPPED AS LOW AS -13 DEGREES. ELSEWHERE...TEMPS WERE NEAR ZERO OR IN THE SINGLE DIGITS. ONCE THE SUN COMES UP...TEMPS WILL STEADILY WARM UP THROUGH THE DAY. MAX TEMPS WILL STILL BE BELOW NORMAL...WITH LOW TO MID 20S FOR VALLEY AREAS /TEENS IN THE HIGH TERRAIN/. TONIGHT...SKIES WILL CLEAR OUT AS THE THE DISTURBANCE MOVES EAST OF THE REGION. THERE STILL MAY BE A BREEZE IN THE EVENING...BUT WINDS SHOULD START TO BECOME LIGHT BY AFTER MIDNIGHT. WITH THE CLEARING SKIES AND FRESH SNOW PACK IN PLACE...HAVE GONE COOLER THAN MOS GUIDANCE FOR MIN TEMPS...WITH SINGLE DIGITS FOR MOST AREAS. SOME BELOW ZERO READINGS WILL OCCUR IN THE ADIRONDACKS...GLENS FALLS AREA...AND SOUTHERN VT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... GENERAL MODEL SUITE AGREEMENT DURING THIS PERIOD AMONG THE GFS/NAM/GEM/ WITH THE GEM/12UTC ECMWF BEING DRIER WITH VERY LITTLE QPF. AT 500HPA MUCH OF THE EASTERN USA IS IN FAST W-NW FLOW WITH SHORT WVS RACING ACROSS RGN. INITIALLY WEAK SFC HIGH PRESSURE IS OVER RGN. AIR MASS OVER RGN IS MOISTURE STARVED. AT SFC A SERIES OF CDFNTS MOVE THROUGH DURING THE PERIOD. THE FIRST SAT NT INTO SUN RESULTS IN INCRG CLOUDS AND SOME -SN AND ENHANCED LAKE EFFECT -SNSH INTO TUG HILL. BUT NOT MUCH IN THE WAY OF ACCUMULATION. ANOTHER CDFNT 500HPA SHORT WV PAIR DROP SLOWLY SOUTH THROUGH RGN MONDAY. AGAIN NOT MUCH MORE THAN -SHSN WITH MAYBE A MODEST ENHANCEMENT BY LK ONTARIO AS IT MOVES THROUGH ON 290-300 VECTORS. HIGH PRESSURE BUILDS S IN ITS WAKE INTO RGN MONDAY NIGHT. OVERALL TEMPS DURING THIS PERIOD WILL BE 5-10 DEG BLO NORMALS. && .LONG TERM /TUESDAY THROUGH THURSDAY/... DURING THIS PERIOD FAST 500HPA FLOW SHIFTS FM NW TO W THEN SW AS SHRTS WV DIG A TROF OVER THE E USA THU. AT SFC HIGH PRESSURE WILL REMAIN IN PLACE THROUGH WED AND SLIDES OFFSHORE WED NT. THE FIRST TWO DAYS ALL THE GUIDANCE (GFS/ECMWF/HPC)IS IN AGREEMENT. THURSDAY AGREEMENT GOES OUT THE WINDOW AS DIVERGE REIGNS. TUES THE LAST 500HPA SHORT WV IN THE NW FLOW PASSES ACROSS RGN WITH GFS MAINLY FAIR AND ECMWF SUG MORE CLOUDINESS AND SCT -SHSN. HIGH PRESSURE LINGERS AT THE SFC INTO WED EVNG. STILL A TRANQUIL MAINLY DRY PERIOD THROUGH WED NT. THU WHILE ALL THE MDLS CARVE OUT OR BRING A SIGNIFICANT 500HPA TROF INTO THE NORTHEAST. WHAT HAPPENS AT THE SFC IS VERY DIFFERENT BTWN THEM. OPERATIONAL GFS/GEM KEEP N BRANCH AND S BRANCH DYNAMICS SEPARATE. GEM PASSES CSTL LOW WELL S OF RGN AND OUT TO SEA. THE GFS DEVELOPS COASTAL LOW WELL OFF SHORE...OVER AND EAST OF GULF STREAM...WITH AND ONLY THE 500HPA SHORT WV AND ITS MODEST CLIPPER IMPACTING THE RGN WITH SOME -SHSN MUCH LIKE THE SYSTEMS WE`VE BEEN HAVING MOST OF THE WEEK. HWVR THE OPERATIONAL RUN OF THE GFS IS AMONG THE 10 OR SO IN ITS OWN ENSEMBLE THAT LEAN TWRD THIS SCENARIO. ITS OTHER 10 MEMBERS HAVE 0.4 TO 1.4 IN QPF MUCH LIKE THE ECMWF DESCRIBED BLO. THE ECMWF DEVELOPS THE CSTL LOW OVER THE VA CAPES WED NT...AND SENDS IT NE TWRD BOS THU NT...RIGHT INSIDE THE BENCHMARK...AND IMPLYING A SIGNIFICANT SNOW EVENT FOR THE FCA WITH 0.50-0.60 QPF ACROSS FCA. OVERNIGHT HPC GUID ALSO LEANS TWRD ECMWF SOLTN...BUT NOT TOTALLY. THE MDL DIFFERENCES SEEM TIED AS USUAL TO HOW AND WHERE THE RESPECTIVE MODELS PHASE VARIOUS 500HPA SHORT WVS INTO THE EASTERN TROF ON THU. WHILE THERE REMAINS MUCH UNCERTAINTY AS TO THE EVENT 6 DAYS OUT...THERE`S AN INCREASING SIGNAL IN THE GUID AT THIS POINT. TEMPS WILL BEGIN THIS PERIOD WELL BLOW NORMALS AND END NR TO SLIGHTLY ABV NORMALS. AS SUCH WILL POPULATE WITH HPC ATTM. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THE DAY TODAY AND INTO TONIGHT. SCT-BKN STRATOCU AND MID LEVEL CLOUDS WILL MOVE IN THROUGH THE MORNING HOURS AND CONTINUE INTO THE AFTERNOON THANKS TO A PASSING UPPER LEVEL DISTURBANCE MOVING ACROSS THE REGION. LITTLE MOISTURE IS ASSOCIATED WITH THIS FEATURE...SO ONLY SOME FLURRIES ARE EXPECTED. LIGHT WINDS WILL BECOME WESTERLY BY AROUND 5-10 KTS THIS MORNING. THERE MAY BE A FEW HIGHER GUSTS AT KALB/KPSF. WINDS WILL DIMINISH DURING THE EVENING...AND CLOUDS WILL BEGIN TO DECREASE AS THE DISTURBANCE MOVES EASTWARD. MOST SITES LOOK TO BE NEARLY CLEAR BY THE LATE EVENING HOURS AND THIS WILL CONTINUE THROUGH THE ENTIRE OVERNIGHT. OUTLOOK... SATURDAY NIGHT/SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. SUNDAY NIGHT/MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. MONDAY NIGHT TO WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT WEEK AS IT WILL BE DRY OR ANY PRECIPITATION THAT FALLS WILL BE SNOW. EXPECTING DRY CONDITIONS EXPECTED THROUGH SATURDAY...EXCEPT FOR SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. THERE IS A CHANCE FOR MAINLY LIGHT SNOWFALL ACROSS THE REGION SATURDAY NIGHT INTO MONDAY. A STORM MAY MOVE UP THE EAST COAST THURSDAY WITH THE POTENTIAL FOR SNOWFALL. ITS TRACK REMAINS HIGHLY UNCERTAIN AT THIS TIME. WITH TEMPERATURES EXPECTED TO BE BELOW NORMAL FOR THE NEXT SEVERAL DAYS...ICE WILL THICKEN 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. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...IAA/SNYDER NEAR TERM...IAA/FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...IAA/FRUGIS HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
627 AM EST FRI FEB 7 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY TO THE MID ATLANTIC REGION THROUGH SATURDAY. IT WILL BRING MAINLY DRY COLD WEATHER...WITH SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. A SERIES OF COLD FRONTS WILL CROSS THE REGION SUNDAY AND MONDAY WITH SOME LIGHT SNOWFALL. HIGH PRESSURE WILL BUILD BACK INTO THE NORTHEAST TUESDAY AND WEDNESDAY. A STORM MAY MOVE UP THE COAST THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 626 AM EST...AN UPPER LEVEL DISTURBANCE EMBEDDED WITHIN MAINLY ZONAL FLOW ALOFT IS IN THE PROCESS OF MOVING ACROSS UPSTATE NY. THIS NORTHERN STREAM FEATURE IS RATHER MOISTURE STARVED...AND IS DOING LITTLE SYNOPTICALLY OTHER THAN PRODUCING SOME A BATCH OF CLOUDS ACROSS WESTERN PARTS OF THE REGION. SKIES ARE GENERALLY MOSTLY CLEAR FOR SOUTHERN AND EASTERN AREAS. MEANWHILE...THE PERSISTENT W-SW FLOW IN THE LOW AND MID LEVELS AHEAD OF THIS DISTURBANCE IS ALLOWING FOR A BAND OF LAKE EFFECT SNOW OFF LAKE ONTARIO. DESPITE LOW INVERSION HEIGHTS AND THE LACK OF A MULTI-LAKE CONNECTION...THE LONG FETCH ACROSS LAKE ONTARIO IS ALLOWING FOR SOME MODERATE TO HEAVY SNOW WITHIN THIS BAND...AND AN INLAND EXTENT REACHING INTO THE NORTHWESTERN ADIRONDACKS. HOWEVER...THE ORIENTATION OF THE BAND IS KEEPING THE HEAVIEST ECHOES TO THE WEST AND NORTH OF OUR AREA. OVER THE NEXT FEW HOURS...THIS BAND WILL SLOWLY START TO WEAKEN AND DRIFT SOUTH...IMPACTING THE FAR NORTHWESTERN CORNER OF OUR CWA...WHICH IS MOSTLY UNINHABITED FOREST PRESERVE OF THE ADIRONDACKS. THE APPROACHING UPPER LEVEL DISTURBANCE WILL DISRUPT THE FLOW ENOUGH BY THE LATE MORNING HOURS TO SIGNIFICANTLY DECREASE THE INTENSITY AND EXTENT OF THIS BAND. BEFORE THAT OCCURS...AN INCH OR TWO OF ACCUMULATION IS POSSIBLE ACROSS FAR NORTHERN PORTIONS OF HERKIMER COUNTY. THIS MOVEMENT AND WEAKENING IS SHOWN IN THE 09Z 3KM HRRR COMPOSITE REFLECTIVITY FORECAST PRODUCT...AS WELL AS THE 06Z RUN OF OUR LOCAL HIRESWRF. BY THE AFTN...WE WILL DECREASE POPS ACROSS THE REGION...WITH THE BEST SNOW BY THAT POINT LIMITED TO AREAS NEAR THE LAKE SHORE OF LAKE ONTARIO. OTHERWISE...IT WILL REMAIN MAINLY DRY OVER THE REMAINDER OF THE REGION TODAY...WITH JUST SOME PASSING CLOUDS. CAN/T TOTALLY RULE OUT A FEW FLURRIES WITH THE PASSING UPPER LEVEL DISTURBANCE FOR WESTERN PARTS OF THE AREA THIS MORNING /BASED ON CURRENT UPSTREAMS OBS IN CENTRAL NY/...BUT NO MEASURABLE SNOW ACCUMULATION IS EXPECTED. WINDS WILL PICK UP DURING THE AFTERNOON HOURS AS THE SHORTWAVE MOVES ACROSS THE REGION...WITH SOME GUSTS IN THE 10-20 MPH RANGE...ESP IN AREAS OF CHANNELED FLOW. SOME SHELTERED AREAS THAT HAD NO WIND AND HAD MAINLY CLEAR SKIES GOT VERY COLD THIS MORNING...SUCH AS IN THE GLENS FALLS AREA...WHERE IT DROPPED AS LOW AS -13 DEGREES. ELSEWHERE...TEMPS WERE NEAR ZERO OR IN THE SINGLE DIGITS. ONCE THE SUN COMES UP...TEMPS WILL STEADILY WARM UP THROUGH THE DAY. MAX TEMPS WILL STILL BE BELOW NORMAL...WITH LOW TO MID 20S FOR VALLEY AREAS /TEENS IN THE HIGH TERRAIN/. TONIGHT...SKIES WILL CLEAR OUT AS THE THE DISTURBANCE MOVES EAST OF THE REGION. THERE STILL MAY BE A BREEZE IN THE EVENING...BUT WINDS SHOULD START TO BECOME LIGHT BY AFTER MIDNIGHT. WITH THE CLEARING SKIES AND FRESH SNOW PACK IN PLACE...HAVE GONE COOLER THAN MOS GUIDANCE FOR MIN TEMPS...WITH SINGLE DIGITS FOR MOST AREAS. SOME BELOW ZERO READINGS WILL OCCUR IN THE ADIRONDACKS...GLENS FALLS AREA...AND SOUTHERN VT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... GENERAL MODEL SUITE AGREEMENT DURING THIS PERIOD AMONG THE GFS/NAM/GEM/ WITH THE GEM/12UTC ECMWF BEING DRIER WITH VERY LITTLE QPF. AT 500HPA MUCH OF THE EASTERN USA IS IN FAST W-NW FLOW WITH SHORT WVS RACING ACROSS RGN. INITIALLY WEAK SFC HIGH PRESSURE IS OVER RGN. AIR MASS OVER RGN IS MOISTURE STARVED. AT SFC A SERIES OF CDFNTS MOVE THROUGH DURING THE PERIOD. THE FIRST SAT NT INTO SUN RESULTS IN INCRG CLOUDS AND SOME -SN AND ENHANCED LAKE EFFECT -SNSH INTO TUG HILL. BUT NOT MUCH IN THE WAY OF ACCUMULATION. ANOTHER CDFNT 500HPA SHORT WV PAIR DROP SLOWLY SOUTH THROUGH RGN MONDAY. AGAIN NOT MUCH MORE THAN -SHSN WITH MAYBE A MODEST ENHANCEMENT BY LK ONTARIO AS IT MOVES THROUGH ON 290-300 VECTORS. HIGH PRESSURE BUILDS S IN ITS WAKE INTO RGN MONDAY NIGHT. OVERALL TEMPS DURING THIS PERIOD WILL BE 5-10 DEG BLO NORMALS. && .LONG TERM /TUESDAY THROUGH THURSDAY/... DURING THIS PERIOD FAST 500HPA FLOW SHIFTS FM NW TO W THEN SW AS SHRTS WV DIG A TROF OVER THE E USA THU. AT SFC HIGH PRESSURE WILL REMAIN IN PLACE THROUGH WED AND SLIDES OFFSHORE WED NT. THE FIRST TWO DAYS ALL THE GUIDANCE (GFS/ECMWF/HPC)IS IN AGREEMENT. THURSDAY AGREEMENT GOES OUT THE WINDOW AS DIVERGE REIGNS. TUES THE LAST 500HPA SHORT WV IN THE NW FLOW PASSES ACROSS RGN WITH GFS MAINLY FAIR AND ECMWF SUG MORE CLOUDINESS AND SCT -SHSN. HIGH PRESSURE LINGERS AT THE SFC INTO WED EVNG. STILL A TRANQUIL MAINLY DRY PERIOD THROUGH WED NT. THU WHILE ALL THE MDLS CARVE OUT OR BRING A SIGNIFICANT 500HPA TROF INTO THE NORTHEAST. WHAT HAPPENS AT THE SFC IS VERY DIFFERENT BTWN THEM. OPERATIONAL GFS/GEM KEEP N BRANCH AND S BRANCH DYNAMICS SEPARATE. GEM PASSES CSTL LOW WELL S OF RGN AND OUT TO SEA. THE GFS DEVELOPS COASTAL LOW WELL OFF SHORE...OVER AND EAST OF GULF STREAM...WITH AND ONLY THE 500HPA SHORT WV AND ITS MODEST CLIPPER IMPACTING THE RGN WITH SOME -SHSN MUCH LIKE THE SYSTEMS WE`VE BEEN HAVING MOST OF THE WEEK. HWVR THE OPERATIONAL RUN OF THE GFS IS AMONG THE 10 OR SO IN ITS OWN ENSEMBLE THAT LEAN TWRD THIS SCENARIO. ITS OTHER 10 MEMBERS HAVE 0.4 TO 1.4 IN QPF MUCH LIKE THE ECMWF DESCRIBED BLO. THE ECMWF DEVELOPS THE CSTL LOW OVER THE VA CAPES WED NT...AND SENDS IT NE TWRD BOS THU NT...RIGHT INSIDE THE BENCHMARK...AND IMPLYING A SIGNIFICANT SNOW EVENT FOR THE FCA WITH 0.50-0.60 QPF ACROSS FCA. OVERNIGHT HPC GUID ALSO LEANS TWRD ECMWF SOLTN...BUT NOT TOTALLY. THE MDL DIFFERENCES SEEM TIED AS USUAL TO HOW AND WHERE THE RESPECTIVE MODELS PHASE VARIOUS 500HPA SHORT WVS INTO THE EASTERN TROF ON THU. WHILE THERE REMAINS MUCH UNCERTAINTY AS TO THE EVENT 6 DAYS OUT...THERE`S AN INCREASING SIGNAL IN THE GUID AT THIS POINT. TEMPS WILL BEGIN THIS PERIOD WELL BLOW NORMALS AND END NR TO SLIGHTLY ABV NORMALS. AS SUCH WILL POPULATE WITH HPC ATTM. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THE DAY TODAY AND INTO TONIGHT. SCT-BKN STRATOCU AND MID LEVEL CLOUDS WILL MOVE IN THROUGH THE MORNING HOURS AND CONTINUE INTO THE AFTERNOON THANKS TO A PASSING UPPER LEVEL DISTURBANCE MOVING ACROSS THE REGION. LITTLE MOISTURE IS ASSOCIATED WITH THIS FEATURE...SO NO PRECIP IS EXPECTED. LIGHT WINDS WILL BECOME WESTERLY BY AROUND 5-10 KTS THIS MORNING. THERE MAY BE A FEW HIGHER GUSTS AT KALB/KPSF. WINDS WILL DIMINISH DURING THE EVENING...AND CLOUDS WILL BEGIN TO DECREASE AS THE DISTURBANCE MOVES EASTWARD. MOST SITES LOOK TO BE NEARLY CLEAR BY THE LATE EVENING HOURS AND THIS WILL CONTINUE THROUGH THE ENTIRE OVERNIGHT. OUTLOOK... SATURDAY NIGHT/SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. SUNDAY NIGHT/MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. MONDAY NIGHT TO WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT WEEK AS IT WILL BE DRY OR ANY PRECIPITATION THAT FALLS WILL BE SNOW. EXPECTING DRY CONDITIONS EXPECTED THROUGH SATURDAY...EXCEPT FOR SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. THERE IS A CHANCE FOR MAINLY LIGHT SNOWFALL ACROSS THE REGION SATURDAY NIGHT INTO MONDAY. A STORM MAY MOVE UP THE EAST COAST THURSDAY WITH THE POTENTIAL FOR SNOWFALL. ITS TRACK REMAINS HIGHLY UNCERTAIN AT THIS TIME. WITH TEMPERATURES EXPECTED TO BE BELOW NORMAL FOR THE NEXT SEVERAL DAYS...ICE WILL THICKEN 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. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...FRUGIS HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
331 AM EST FRI FEB 7 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY TO THE MID ATLANTIC REGION THROUGH SATURDAY. IT WILL BRING MAINLY DRY COLD WEATHER...WITH SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. A SERIES OF COLD FRONTS WILL CROSS THE REGION SUNDAY AND MONDAY WITH SOME LIGHT SNOWFALL. HIGH PRESSURE WILL BUILD BACK INTO THE NORTHEAST TUESDAY AND WEDNESDAY. A STORM MAY MOVE UP THE COAST THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 AM EST...AN UPPER LEVEL DISTURBANCE EMBEDDED WITHIN MAINLY ZONAL FLOW ALOFT IS IN THE PROCESS OF MOVING ACROSS UPSTATE NY. THIS NORTHERN STREAM FEATURE IS RATHER MOISTURE STARVED...AND IS DOING LITTLE SYNOPTICALLY OTHER THAN PRODUCING SOME A BATCH OF CLOUDS ACROSS WESTERN PARTS OF THE REGION. SKIES ARE GENERALLY MOSTLY CLEAR FOR SOUTHERN AND EASTERN AREAS. MEANWHILE...THE PERSISTENT W-SW FLOW IN THE LOW AND MID LEVELS IS ALLOWING FOR A BAND OF LAKE EFFECT SNOW OFF LAKE ONTARIO. MOST OF THIS ACTIVITY IS CURRENTLY WEST OF THE REGION CLOSER TO THE LAKE SHORE OF LAKE ONTARIO AND OVER THE TUG HILL PLATEAU. THE LACK OF A MULTI LAKE CONNECTION AND INVERSION HEIGHTS OF ONLY AROUND 1.5 KM WILL PREVENT SIGNIFICANT INLAND EXTENT OF THE BAND. THIS IS ALSO SHOWN IN THE 04Z 3KM HRRR COMPOSITE REFLECTIVITY FORECAST PRODUCT...AS WELL AS OUR LOCAL HIRESWRF...WHICH KEEPS MOST OF THE SNOW SHOWER ACTIVITY WITH THIS BAND TO THE WEST OF OUR AREA. STILL...SOME SNOW SHOWERS MAY OCCASIONALLY REACH INTO EXTREME NORTHERN HERKIMER COUNTY /NORTH OF OLD FORGE/...SO WE HAVE ALLOWED FOR SOME LIGHT SNOW ACCUMULATION OF AN INCH OR TWO FOR THAT AREA. THE BEST CHANCE FOR LAKE EFFECT WILL BE DURING THE MORNING HOURS...AS THE PASSING DISTURBANCE ALOFT...ALONG WITH THE LOWERING INVERSION HEIGHTS...LOOKS TO DISRUPT THE FLOW AND DIMINISH THE INTENSITY/EXTENT OF THE LAKE BAND BY THIS AFTN. OTHERWISE...IT WILL REMAIN MAINLY DRY OVER THE REMAINDER OF THE REGION TODAY...WITH JUST SOME PASSING CLOUDS. CAN/T TOTALLY RULE OUT A FEW FLURRIES WITH THE PASSING UPPER LEVEL DISTURBANCE FOR WESTERN PARTS OF THE AREA THIS MORNING /BASED ON CURRENT UPSTREAMS OBS IN CENTRAL NY/...BUT NO MEASURABLE SNOW ACCUMULATION IS EXPECTED. WINDS WILL PICK UP DURING THE AFTERNOON HOURS AS THE SHORTWAVE MOVES ACROSS THE REGION...WITH SOME GUSTS IN THE 10-20 MPH RANGE...ESP IN AREAS OF CHANNELED FLOW. AFTER A VERY CHILLY MORNING /MINS AROUND ZERO IN MANY AREAS/...TEMPS WILL WARM UP THROUGH THE DAY. MAX TEMPS WILL STILL BE BELOW NORMAL...WITH LOW TO MID 20S FOR VALLEY AREAS /TEENS IN THE HIGH TERRAIN/. TONIGHT...SKIES WILL CLEAR OUT AS THE THE DISTURBANCE MOVES EAST OF THE REGION. THERE STILL MAY BE A BREEZE IN THE EVENING...BUT WINDS SHOULD START TO BECOME LIGHT BY AFTER MIDNIGHT. WITH THE CLEARING SKIES AND FRESH SNOW PACK IN PLACE...HAVE GONE COOLER THAN MOS GUIDANCE FOR MIN TEMPS...WITH SINGLE DIGITS FOR MOST AREAS /SOME BELOW ZERO READINGS IN THE ADIRONDACKS...GLENS FALLS AREA...AND SOUTHERN VT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... GENERAL MODEL SUITE AGREEMENT DURING THIS PERIOD AMONG THE GFS/NAM/GEM/ WITH THE GEM/12UTC ECMWF BEING DRIER WITH VERY LITTLE QPF. AT 500HPA MUCH OF THE EASTERN USA IS IN FAST W-NW FLOW WITH SHORT WVS RACING ACROSS RGN. INITIALLY WEAK SFC HIGH PRESSURE IS OVER RGN. AIR MASS OVER RGN IS MOISTURE STARVED. AT SFC A SERIES OF CDFNTS MOVE THROUGH DURING THE PERIOD. THE FIRST SAT NT INTO SUN RESULTS IN INCRG CLOUDS AND SOME -SN AND ENHANCED LAKE EFFECT -SNSH INTO TUG HILL. BUT NOT MUCH IN THE WAY OF ACCUMULATION. ANOTHER CDFNT 500HPA SHORT WV PAIR DROP SLOWLY SOUTH THROUGH RGN MONDAY. AGAIN NOT MUCH MORE THAN -SHSN WITH MAYBE A MODEST ENHANCEMENT BY LK ONTARIO AS IT MOVES THROUGH ON 290-300 VECTORS. HIGH PRESSURE BUILDS S IN ITS WAKE INTO RGN MONDAY NIGHT. OVERALL TEMPS DURING THIS PERIOD WILL BE 5-10 DEG BLO NORMALS. && .LONG TERM /TUESDAY THROUGH THURSDAY/... DURING THIS PERIOD FAST 500HPA FLOW SHIFTS FM NW TO W THEN SW AS SHRTS WV DIG A TROF OVER THE E USA THU. AT SFC HIGH PRESSURE WILL REMAIN IN PLACE THROUGH WED AND SLIDES OFFSHORE WED NT. THE FIRST TWO DAYS ALL THE GUIDANCE (GFS/ECMWF/HPC)IS IN AGREEMENT. THURSDAY AGREEMENT GOES OUT THE WINDOW AS DIVERGE REIGNS. TUES THE LAST 500HPA SHORT WV IN THE NW FLOW PASSES ACROSS RGN WITH GFS MAINLY FAIR AND ECMWF SUG MORE CLOUDINESS AND SCT -SHSN. HIGH PRESSURE LINGERS AT THE SFC INTO WED EVNG. STILL A TRANQUIL MAINLY DRY PERIOD THROUGH WED NT. THU WHILE ALL THE MDLS CARVE OUT OR BRING A SIGNIFICANT 500HPA TROF INTO THE NORTHEAST. WHAT HAPPENS AT THE SFC IS VERY DIFFERENT BTWN THEM. OPERATIONAL GFS/GEM KEEP N BRANCH AND S BRANCH DYNAMICS SEPARATE. GEM PASSES CSTL LOW WELL S OF RGN AND OUT TO SEA. THE GFS DEVELOPS COASTAL LOW WELL OFF SHORE...OVER AND EAST OF GULF STREAM...WITH AND ONLY THE 500HPA SHORT WV AND ITS MODEST CLIPPER IMPACTING THE RGN WITH SOME -SHSN MUCH LIKE THE SYSTEMS WE`VE BEEN HAVING MOST OF THE WEEK. HWVR THE OPERATIONAL RUN OF THE GFS IS AMONG THE 10 OR SO IN ITS OWN ENSEMBLE THAT LEAN TWRD THIS SCENARIO. ITS OTHER 10 MEMBERS HAVE 0.4 TO 1.4 IN QPF MUCH LIKE THE ECMWF DESCRIBED BLO. THE ECMWF DEVELOPS THE CSTL LOW OVER THE VA CAPES WED NT...AND SENDS IT NE TWRD BOS THU NT...RIGHT INSIDE THE BENCHMARK...AND IMPLYING A SIGNIFICANT SNOW EVENT FOR THE FCA WITH 0.50-0.60 QPF ACROSS FCA. OVERNIGHT HPC GUID ALSO LEANS TWRD ECMWF SOLTN...BUT NOT TOTALLY. THE MDL DIFFERENCES SEEM TIED AS USUAL TO HOW AND WHERE THE RESPECTIVE MODELS PHASE VARIOUS 500HPA SHORT WVS INTO THE EASTERN TROF ON THU. WHILE THERE REMAINS MUCH UNCERTAINTY AS TO THE EVENT 6 DAYS OUT...THERE`S AN INCREASING SIGNAL IN THE GUID AT THIS POINT. TEMPS WILL BEGIN THIS PERIOD WELL BLOW NORMALS AND END NR TO SLIGHTLY ABV NORMALS. AS SUCH WILL POPULATE WITH HPC ATTM. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THE DAY ON FRIDAY. SCT-BKN STRATOCU CLOUDS WILL MOVE IN TOWARDS DAYBREAK AND CONTINUE INTO THE DAY ON FRIDAY. SOME PASSING MID LEVEL CLOUDS WILL MOVE IN AS WELL...AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS THE REGION. LITTLE MOISTURE IS ASSOCIATED WITH THIS FEATURE...SO NO PRECIP IS EXPECTED. LIGHT WINDS WILL BECOME WESTERLY BY AROUND 10 KTS ON FRIDAY MORNING. THERE MAY BE A FEW HIGHER GUSTS AT KALB/KPSF. WINDS WILL DIMINISH ON FRIDAY EVENING...AND CLOUDS WILL BEGIN TO DECREASE AS THE DISTURBANCE MOVES EASTWARD. MOST SITES LOOK TO BE NEARLY CLEAR BY THE LATE EVENING HOURS. OUTLOOK... SATURDAY NIGHT/SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. SUNDAY NIGHT/MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. MONDAY NIGHT TO WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT WEEK AS IT WILL BE DRY OR ANY PRECIPITATION THAT FALLS WILL BE SNOW. EXPECTING DRY CONDITIONS EXPECTED THROUGH SATURDAY...EXCEPT FOR SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. THERE IS A CHANCE FOR MAINLY LIGHT SNOWFALL ACROSS THE REGION SATURDAY NIGHT INTO MONDAY. A STORM MAY MOVE UP THE EAST COAST THURSDAY WITH THE POTENTIAL FOR SNOWFALL. ITS TRACK REMAINS HIGHLY UNCERTAIN AT THIS TIME. WITH TEMPERATURES EXPECTED TO BE BELOW NORMAL FOR THE NEXT SEVERAL DAYS...ICE WILL THICKEN 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. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...FRUGIS HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
309 AM EST FRI FEB 7 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY TO THE MID ATLANTIC REGION THROUGH SATURDAY. IT WILL BRING MAINLY DRY COLD WEATHER...WITH SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. A SERIES OF COLD FRONTS WILL CROSS THE REGION SUNDAY AND MONDAY WITH SOME LIGHT SNOWFALL. HIGH PRESSURE WILL BUILD BACK INTO THE NORTHEAST TUESDAY AND WEDNESDAY. A STORM MAY MOVE UP THE COAST THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 AM EST...AN UPPER LEVEL DISTURBANCE EMBEDDED WITHIN MAINLY ZONAL FLOW ALOFT IS IN THE PROCESS OF MOVING ACROSS UPSTATE NY. THIS NORTHERN STREAM FEATURE IS RATHER MOISTURE STARVED...AND IS DOING LITTLE SYNOPTICALLY OTHER THAN PRODUCING SOME A BATCH OF CLOUDS ACROSS WESTERN PARTS OF THE REGION. SKIES ARE GENERALLY MOSTLY CLEAR FOR SOUTHERN AND EASTERN AREAS. MEANWHILE...THE PERSISTENT W-SW FLOW IN THE LOW AND MID LEVELS IS ALLOWING FOR A BAND OF LAKE EFFECT SNOW OFF LAKE ONTARIO. MOST OF THIS ACTIVITY IS CURRENTLY WEST OF THE REGION CLOSER TO THE LAKE SHORE OF LAKE ONTARIO AND OVER THE TUG HILL PLATEAU. THE LACK OF A MULTI LAKE CONNECTION AND INVERSION HEIGHTS OF ONLY AROUND 1.5 KM WILL PREVENT SIGNIFICANT INLAND EXTENT OF THE BAND. THIS IS ALSO SHOWN IN THE 04Z 3KM HRRR COMPOSITE REFLECTIVITY FORECAST PRODUCT...AS WELL AS OUR LOCAL HIRESWRF...WHICH KEEPS MOST OF THE SNOW SHOWER ACTIVITY WITH THIS BAND TO THE WEST OF OUR AREA. STILL...SOME SNOW SHOWERS MAY OCCASIONALLY REACH INTO EXTREME NORTHERN HERKIMER COUNTY /NORTH OF OLD FORGE/...SO WE HAVE ALLOWED FOR SOME LIGHT SNOW ACCUMULATION OF AN INCH OR TWO FOR THAT AREA. THE BEST CHANCE FOR LAKE EFFECT WILL BE DURING THE MORNING HOURS...AS THE PASSING DISTURBANCE ALOFT...ALONG WITH THE LOWERING INVERSION HEIGHTS...LOOKS TO DISRUPT THE FLOW AND DIMINISH THE INTENSITY/EXTENT OF THE LAKE BAND BY THIS AFTN. OTHERWISE...IT WILL REMAIN MAINLY DRY OVER THE REMAINDER OF THE REGION TODAY...WITH JUST SOME PASSING CLOUDS. CAN/T TOTALLY RULE OUT A FEW FLURRIES WITH THE PASSING UPPER LEVEL DISTURBANCE FOR WESTERN PARTS OF THE AREA THIS MORNING /BASED ON CURRENT UPSTREAMS OBS IN CENTRAL NY/...BUT NO MEASURABLE SNOW ACCUMULATION IS EXPECTED. WINDS WILL PICK UP DURING THE AFTERNOON HOURS AS THE SHORTWAVE MOVES ACROSS THE REGION...WITH SOME GUSTS IN THE 10-20 MPH RANGE...ESP IN AREAS OF CHANNELED FLOW. AFTER A VERY CHILLY MORNING /MINS AROUND ZERO IN MANY AREAS/...TEMPS WILL WARM UP THROUGH THE DAY. MAX TEMPS WILL STILL BE BELOW NORMAL...WITH LOW TO MID 20S FOR VALLEY AREAS /TEENS IN THE HIGH TERRAIN/. TONIGHT...SKIES WILL CLEAR OUT AS THE THE DISTURBANCE MOVES EAST OF THE REGION. THERE STILL MAY BE A BREEZE IN THE EVENING...BUT WINDS SHOULD START TO BECOME LIGHT BY AFTER MIDNIGHT. WITH THE CLEARING SKIES AND FRESH SNOW PACK IN PLACE...HAVE GONE COOLER THAN MOS GUIDANCE FOR MIN TEMPS...WITH SINGLE DIGITS FOR MOST AREAS /SOME BELOW ZERO READINGS IN THE ADIRONDACKS...GLENS FALLS AREA...AND SOUTHERN VT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... GENERAL MODEL SUITE AGREEMENT DURING THIS PERIOD AMONG THE GFS/NAM/GEM/ WITH THE GEM/12UTC ECMWF BEING DRIER WITH VERY LITTLE QPF. AT 500HPA MUCH OF THE EASTERN USA IS IN FAST W-NW FLOW WITH SHORT WVS RACING ACROSS RGN. INITIALLY WEAK SFC HIGH PRESSURE IS OVER RGN. AIR MASS OVER RGN IS MOISTURE STARVED. AT SFC A SERIES OF CDFNTS MOVE THROUGH DURING THE PERIOD. THE FIRST SAT NT INTO SUN RESULTS IN INCRG CLOUDS AND SOME -SN AND ENHANCED LAKE EFFECT -SNSH INTO TUG HILL. BUT NOT MUCH IN THE WAY OF ACCUMULATION. ANOTHER CDFNT 500HPA SHORT WV PAIR DROP SLOWLY SOUTH THROUGH RGN MONDAY. AGAIN NOT MUCH MORE THAN -SHSN WITH MAYBE A MODEST ENHANCEMENT BY LK ONTARIO AS IT MOVES THROUGH ON 290-300 VECTORS. HIGH PRESSURE BUILDS S IN ITS WAKE INTO RGN MONDAY NIGHT. OVERALL TEMPS DURING THIS PERIOD WILL BE 5-10 DEG BLO NORMALS. && .LONG TERM /TUESDAY THROUGH THURSDAY/... DURING THIS PERIOD FAST 500HPA FLOW SHIFTS FM NW TO W THEN SW AS SHRTS WV DIG A TROF OVER THE E USA THU. AT SFC HIGH PRESSURE WILL REMAIN IN PLACE THROUGH WED AND SLIDES OFFSHORE WED NT. THE FIRST TWO DAYS ALL THE GUIDANCE (GFS/ECMWF/HPC)IS IN AGREEMENT. THURSDAY AGREEMENT GOES OUT THE WINDOW AS DIVERGE REIGNS. TUES THE LAST 500HPA SHORT WV IN THE NW FLOW PASSES ACROSS RGN WITH GFS MAINLY FAIR AND ECMWF SUG MORE CLOUDINESS AND SCT -SHSN. HIGH PRESSURE LINGERS AT THE SFC INTO WED EVNG. STILL A TRANQUIL MAINLY DRY PERIOD THROUGH WED NT. THU WHILE ALL THE MDLS CARVE OUT OR BRING A SIGNIFICANT 500HPA TROF INTO THE NORTHEAST. WHAT HAPPENS AT THE SFC IS VERY DIFFERENT BTWN THEM. OPERATIONAL GFS/GEM KEEP N BRANCH AND S BRANCH DYNAMICS SEPARATE. GEM PASSES CSTL LOW WELL S OF RGN AND OUT TO SEA. THE GFS DEVELOPS COASTAL LOW WELL OFF SHORE...OVER AND EAST OF GULF STREAM...WITH AND ONLY THE 500HPA SHORT WV AND ITS MODEST CLIPPER IMPACTING THE RGN WITH SOME -SHSN MUCH LIKE THE SYSTEMS WE`VE BEEN HAVING MOST OF THE WEEK. HWVR THE OPERATIONAL RUN OF THE GFS IS AMONG THE 10 OR SO IN ITS OWN ENSEMBLE THAT LEAN TWRD THIS SCENARIO. ITS OTHER 10 MEMBERS HAVE 0.4 TO 1.4 IN QPF MUCH LIKE THE ECMWF DESCRIBED BLO. THE ECMWF DEVELOPS THE CSTL LOW OVER THE VA CAPES WED NT...AND SENDS IT NE TWRD BOS THU NT...RIGHT INSIDE THE BENCHMARK...AND IMPLYING A SIGNIFICANT SNOW EVENT FOR THE FCA WITH 0.50-0.60 QPF ACROSS FCA. OVERNIGHT HPC GUID ALSO LEANS TWRD ECMWF SOLTN...BUT NOT TOTALLY. THE MDL DIFFERENCES SEEM TIED AS USUAL TO HOW AND WHERE THE RESPECTIVE MODELS PHASE VARIOUS 500HPA SHORT WVS INTO THE EASTERN TROF ON THU. WHILE THERE REMAINS MUCH UNCERTAINTY AS TO THE EVENT 6 DAYS OUT...THERE`S AN INCREASING SIGNAL IN THE GUID AT THIS POINT. TEMPS WILL BEGIN THIS PERIOD WELL BLOW NORMALS AND END NR TO SLIGHTLY ABV NORMALS. AS SUCH WILL POPULATE WITH HPC ATTM. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THE DAY ON FRIDAY. SCT-BKN STRATOCU CLOUDS WILL MOVE IN TOWARDS DAYBREAK AND CONTINUE INTO THE DAY ON FRIDAY. SOME PASSING MID LEVEL CLOUDS WILL MOVE IN AS WELL...AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS THE REGION. LITTLE MOISTURE IS ASSOCIATED WITH THIS FEATURE...SO NO PRECIP IS EXPECTED. LIGHT WINDS WILL BECOME WESTERLY BY AROUND 10 KTS ON FRIDAY MORNING. THERE MAY BE A FEW HIGHER GUSTS AT KALB/KPSF. WINDS WILL DIMINISH ON FRIDAY EVENING...AND CLOUDS WILL BEGIN TO DECREASE AS THE DISTURBANCE MOVES EASTWARD. MOST SITES LOOK TO BE NEARLY CLEAR BY THE LATE EVENING HOURS. OUTLOOK... FRIDAY NIGHT TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT TO SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN. MONDAY TO TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT WEEK AS IT WILL BE DRY OR ANY PRECIPITATION THAT FALLS WILL BE SNOW. EXPECTING DRY CONDITIONS EXPECTED THROUGH SATURDAY...EXCEPT FOR SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. THERE IS A CHANCE FOR MAINLY LIGHT SNOWFALL ACROSS THE REGION SATURDAY NIGHT INTO MONDAY. A MORE SIGNIFICANT SNOWFALL IS POSSIBLE THURSDAY. WITH TEMPERATURES EXPECTED TO BE BELOW NORMAL FOR THE NEXT SEVERAL DAYS...ICE WILL THICKEN 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. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...FRUGIS HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
244 AM EST FRI FEB 7 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY TO THE MID ATLANTIC REGION THROUGH SATURDAY. IT WILL BRING MAINLY DRY COLD WEATHER...WITH SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. A SERIES OF COLD FRONTS WILL CROSS THE REGION SUNDAY AND MONDAY WITH SOME LIGHT SNOWFALL. HIGH PRESSURE WILL BUILD BACK INTO THE NORTHEAST TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 AM EST...AN UPPER LEVEL DISTURBANCE EMBEDDED WITHIN MAINLY ZONAL FLOW ALOFT IS IN THE PROCESS OF MOVING ACROSS UPSTATE NY. THIS NORTHERN STREAM FEATURE IS RATHER MOISTURE STARVED...AND IS DOING LITTLE SYNOPTICALLY OTHER THAN PRODUCING SOME A BATCH OF CLOUDS ACROSS WESTERN PARTS OF THE REGION. SKIES ARE GENERALLY MOSTLY CLEAR FOR SOUTHERN AND EASTERN AREAS. MEANWHILE...THE PERSISTENT W-SW FLOW IN THE LOW AND MID LEVELS IS ALLOWING FOR A BAND OF LAKE EFFECT SNOW OFF LAKE ONTARIO. MOST OF THIS ACTIVITY IS CURRENTLY WEST OF THE REGION CLOSER TO THE LAKE SHORE OF LAKE ONTARIO AND OVER THE TUG HILL PLATEAU. THE LACK OF A MULTI LAKE CONNECTION AND INVERSION HEIGHTS OF ONLY AROUND 1.5 KM WILL PREVENT SIGNIFICANT INLAND EXTENT OF THE BAND. THIS IS ALSO SHOWN IN THE 04Z 3KM HRRR COMPOSITE REFLECTIVITY FORECAST PRODUCT...AS WELL AS OUR LOCAL HIRESWRF...WHICH KEEPS MOST OF THE SNOW SHOWER ACTIVITY WITH THIS BAND TO THE WEST OF OUR AREA. STILL...SOME SNOW SHOWERS MAY OCCASIONALLY REACH INTO EXTREME NORTHERN HERKIMER COUNTY /NORTH OF OLD FORGE/...SO WE HAVE ALLOWED FOR SOME LIGHT SNOW ACCUMULATION OF AN INCH OR TWO FOR THAT AREA. THE BEST CHANCE FOR LAKE EFFECT WILL BE DURING THE MORNING HOURS...AS THE PASSING DISTURBANCE ALOFT...ALONG WITH THE LOWERING INVERSION HEIGHTS...LOOKS TO DISRUPT THE FLOW AND DIMINISH THE INTENSITY/EXTENT OF THE LAKE BAND BY THIS AFTN. OTHERWISE...IT WILL REMAIN MAINLY DRY OVER THE REMAINDER OF THE REGION TODAY...WITH JUST SOME PASSING CLOUDS. CAN/T TOTALLY RULE OUT A FEW FLURRIES WITH THE PASSING UPPER LEVEL DISTURBANCE FOR WESTERN PARTS OF THE AREA THIS MORNING /BASED ON CURRENT UPSTREAMS OBS IN CENTRAL NY/...BUT NO MEASURABLE SNOW ACCUMULATION IS EXPECTED. WINDS WILL PICK UP DURING THE AFTERNOON HOURS AS THE SHORTWAVE MOVES ACROSS THE REGION...WITH SOME GUSTS IN THE 10-20 MPH RANGE...ESP IN AREAS OF CHANNELED FLOW. AFTER A VERY CHILLY MORNING /MINS AROUND ZERO IN MANY AREAS/...TEMPS WILL WARM UP THROUGH THE DAY. MAX TEMPS WILL STILL BE BELOW NORMAL...WITH LOW TO MID 20S FOR VALLEY AREAS /TEENS IN THE HIGH TERRAIN/. TONIGHT...SKIES WILL CLEAR OUT AS THE THE DISTURBANCE MOVES EAST OF THE REGION. THERE STILL MAY BE A BREEZE IN THE EVENING...BUT WINDS SHOULD START TO BECOME LIGHT BY AFTER MIDNIGHT. WITH THE CLEARING SKIES AND FRESH SNOW PACK IN PLACE...HAVE GONE COOLER THAN MOS GUIDANCE FOR MIN TEMPS...WITH SINGLE DIGITS FOR MOST AREAS /SOME BELOW ZERO READINGS IN THE ADIRONDACKS...GLENS FALLS AREA...AND SOUTHERN VT. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... GENERAL MODEL SUITE AGREEMENT DURING THIS PERIOD AMONG THE GFS/NAM/GEM/ WITH THE GEM/12UTC ECMWF BEING DRIER WITH VERY LITTLE QPF. AT 500HPA MUCH OF THE EASTERN USA IS IN FAST W-NW FLOW WITH SHORT WVS RACING ACROSS RGN. INITIALLY WEAK SFC HIGH PRESSURE IS OVER RGN. AIR MASS OVER RGN IS MOISTURE STARVED. AT SFC A SERIES OF CDFNTS MOVE THROUGH DURING THE PERIOD. THE FIRST SAT NT INTO SUN RESULTS IN INCRG CLOUDS AND SOME -SN AND ENHANCED LAKE EFFECT -SNSH INTO TUG HILL. BUT NOT MUCH IN THE WAY OF ACCUMULATION. ANOTHER CDFNT 500HPA SHORT WV PAIR DROP SLOWLY SOUTH THROUGH RGN MONDAY. AGAIN NOT MUCH MORE THAN -SHSN WITH MAYBE A MODEST ENHANCEMENT BY LK ONTARIO AS IT MOVES THROUGH ON 290-300 VECTORS. HIGH PRESSURE BUILDS S IN ITS WAKE INTO RGN MONDAY NIGHT. OVERALL TEMPS DURING THIS PERIOD WILL BE 5-10 DEG BLO NORMALS. && .LONG TERM /TUESDAY THROUGH THURSDAY/... DURING THIS PERIOD FAST 500HPA FLOW SHIFTS FM NW TO W THEN SW AS SHRTS WV DIG A TROF OVER THE E USA THU. AT SFC HIGH PRESSURE WILL REMAIN IN PLACE THROUGH WED AND SLIDES OFFSHORE WED NT. THE FIRST TWO DAYS ALL THE GUIDANCE (GFS/ECMWF/HPC)IS IN AGREEMENT. THURSDAY AGREEMENT GOES OUT THE WINDOW AS DIVERGE REIGNS. TUES THE LAST 500HPA SHORT WV IN THE NW FLOW PASSES ACROSS RGN WITH GFS MAINLY FAIR AND ECMWF SUG MORE CLOUDINESS AND SCT -SHSN. HIGH PRESSURE LINGERS AT THE SFC INTO WED EVNG. STILL A TRANQUIL MAINLY DRY PERIOD THROUGH WED NT. THU WHILE ALL THE MDLS CARVE OUT OR BRING A SIGNIFICANT 500HPA TROF INTO THE NORTHEAST. WHAT HAPPENS AT THE SFC IS VERY DIFFERENT BTWN THEM. OPERATIONAL GFS/GEM KEEP N BRANCH AND S BRANCH DYNAMICS SEPARATE. GEM PASSES CSTL LOW WELL S OF RGN AND OUT TO SEA. THE GFS DEVELOPS COASTAL LOW WELL OFF SHORE...OVER AND EAST OF GULF STREAM...WITH AND ONLY THE 500HPA SHORT WV AND ITS MODEST CLIPPER IMPACTING THE RGN WITH SOME -SHSN MUCH LIKE THE SYSTEMS WE`VE BEEN HAVING MOST OF THE WEEK. HWVR THE OPERATIONAL RUN OF THE GFS IS AMONG THE 10 OR SO IN ITS OWN ENSEMBLE THAT LEAN TWRD THIS SCENARIO. ITS OTHER 10 MEMBERS HAVE 0.4 TO 1.4 IN QPF MUCH LIKE THE ECMWF DESCRIBED BLO. THE ECMWF DEVELOPS THE CSTL LOW OVER THE VA CAPES WED NT...AND SENDS IT NE TWRD BOS THU NT...RIGHT INSIDE THE BENCHMARK...AND IMPLYING A SIGNIFICANT SNOW EVENT FOR THE FCA WITH 0.50-0.60 QPF ACROSS FCA. OVERNIGHT HPC GUID ALSO LEANS TWRD ECMWF SOLTN...BUT NOT TOTALLY. THE MDL DIFFERENCES SEEM TIED AS USUAL TO HOW AND WHERE THE RESPECTIVE MODELS PHASE VARIOUS 500HPA SHORT WVS INTO THE EASTERN TROF ON THU. WHILE THERE REMAINS MUCH UNCERTAINTY AS TO THE EVENT 6 DAYS OUT...THERE`S AN INCREASING SIGNAL IN THE GUID AT THIS POINT. TEMPS WILL BEGIN THIS PERIOD WELL BLOW NORMALS AND END NR TO SLIGHTLY ABV NORMALS. AS SUCH WILL POPULATE WITH HPC ATTM. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH THE DAY ON FRIDAY. SCT-BKN STRATOCU CLOUDS WILL MOVE IN TOWARDS DAYBREAK AND CONTINUE INTO THE DAY ON FRIDAY. SOME PASSING MID LEVEL CLOUDS WILL MOVE IN AS WELL...AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS THE REGION. LITTLE MOISTURE IS ASSOCIATED WITH THIS FEATURE...SO NO PRECIP IS EXPECTED. LIGHT WINDS WILL BECOME WESTERLY BY AROUND 10 KTS ON FRIDAY MORNING. THERE MAY BE A FEW HIGHER GUSTS AT KALB/KPSF. WINDS WILL DIMINISH ON FRIDAY EVENING...AND CLOUDS WILL BEGIN TO DECREASE AS THE DISTURBANCE MOVES EASTWARD. MOST SITES LOOK TO BE NEARLY CLEAR BY THE LATE EVENING HOURS. OUTLOOK... FRIDAY NIGHT TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT TO SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN. MONDAY TO TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT FIVE DAYS. EXPECTING MAINLY DRY CONDITIONS EXPECTED THROUGH SATURDAY...EXCEPT FOR SOME LAKE EFFECT SNOW SHOWERS OVER THE WESTERN ADIRONDACKS. THERE IS A CHANCE FOR MAINLY LIGHT SNOWFALL ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY. WITH TEMPERATURES EXPECTED TO BE BELOW NORMAL FOR THE NEXT SEVERAL DAYS...ICE WILL THICKEN 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. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...FRUGIS HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
951 AM EST FRI FEB 7 2014 .UPDATE...STRONG HIGH PRES SYSTEM IS LOCATED OVER THE TN VALLEY AROUND 1035 MB AND A FRONTAL BOUNDARY REMAINS OVER SRN PARTS OF FL. INVERTED TROUGH CONTINUES OFFSHORE OF THE FL EAST COAST WITH WEAK LOW PRES ALONG THE FRONT JUST N OF THE BAHAMAS. A RELATIVELY SHALLOW COOL AIRMASS IN THE REGION UP TO ABOUT 2000 FT WITH SW FLOW ALOFT. LATEST RAP ANALYSIS SHOWS ONE WEAK SHORTWAVE LIFTING OUT TO THE NE OVER SE GA BUT OTHERWISE SOME NVA EXPECTED UP UNTIL ABOUT 21Z WHEN ANOTHER SHORTWAVE IN THE WSW FLOW ALOFT BEGINS TO IMPACT OUR SW PORTION OF ZONES. SATELLITE DATA SHOWS MULTILAYERED CLOUDS FROM BRUNSWICK GA TO LIVE OAK SWD ASSOCIATED WITH OVERRUNNING CONDITIONS ATOP THE COOL BOUNDARY. RADAR SHOWERS A FEW SHOWERS AND PATCHY LIGHT DRIZZLE OVER THE SRN ZONES. FOR REST OF TODAY THROUGH TONIGHT...BELIEVE THE CHANCE OF RAIN WILL CONTINUE TO TAPER OFF THROUGH EARLY-MID AFTERNOON AND THEN PICK UP AGAIN GRADUALLY AS LOW PRES OFFSHORE OF FL EAST COAST MOVES NWD TO THE ABOUT THE LATITUDE OF JAX TO AROUND 180 NM. EXPECT INCREASED MOISTURE CONVERGENCE AND ISENTROPIC LIFTING LATER TODAY AND TONIGHT. WE INCREASE POPS LATER TODAY SE PARTS BUT NOT HIGHER THAN CHANCE CATEGORY. EXPECT THAT TONIGHT GIVEN SYNOPTIC FORCING AND ABUNDANT MOISTURE WILL BOOST POPS INTO THE LIKELY AND CATEGORICAL RANGE...WITH HIGHEST COVERAGE AND QPF OVER SE GA. TEMPS BELOW NORMAL FOR TODAY WITH HIGHS IN THE MID 50S COAST TO AROUND 60 INLAND AND CURRENT TEMP FORECAST LOOKS REASONABLE. && .AVIATION...IFR TO LOW END MVFR CONDITIONS EXPECTED TO PREVAIL THROUGH MUCH OF THE DAY FOR NE FL TAFS. PREVAILING VFR CIGS AROUND 3500-5000 FT AT SSI BUT CAN`T DISCOUNT SOME PERIODS OF MVFR AND POSSIBLY IFR BY MID AFTN THROUGH EVENING HOURS AS LOW LEVEL WINDS TURN MORE NELY. FLIGHT CONDITIONS DETERIORATE REGION WIDE TONIGHT AS CLOUD COVER AND RAIN CHANCES INCREASE WITH LOW MVFR/IFR CIGS AND OCNL VSBY 1-3 MILES IN RAIN AND BR. && .MARINE...WINDS ARE IN THE SCA RANGE BOTH NEARSHORE AND OFFSHORE SO RAISED SCA FOR NEAR-SHORE WATERS S OF MAYPORT TIL THIS AFTN AND EXTENDED OFFSHORE SCA INTO EVENING. WINDS EXPECTED TO SHIFT TO ENE THEN NE LATER TONIGHT AND SAT AS SFC LOW NEARS OUR WATERS. SOME UNCERTAINTY ABOUT EXTENT AND DURATION OF SCA FOR OFFSHORE WATERS DUE TO APPROACHING SFC LOW. RIP CURRENTS: MODERATE RISK TODAY WITH SIDE SHORE OR ONSHORE FLOW AND EAST SWELLS. LOW TO MODERATE RISK SATURDAY AS FLOW BECOMES OFFSHORE. && .PRELIMINARY POINT TEMPS/POPS... AMG 59 45 62 39 / 10 90 50 0 SSI 54 48 58 46 / 20 90 80 10 JAX 56 48 62 46 / 20 90 80 10 SGJ 59 54 61 50 / 30 70 90 10 GNV 59 52 63 44 / 20 70 80 10 OCF 62 54 65 48 / 20 50 90 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ALTAMAHA SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE- FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE- ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE. SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR FERNANDINA BEACH TO ST AUGUSTINE FL OUT 20 NM-ST AUGUSTINE TO FLAGLER BEACH FL OUT 20 NM. && $$ SHASHY/TRABERT/WALKER
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
936 AM EST FRI FEB 7 2014 .UPDATE... TEMP AND POP FORECAST TODAY REMAINS THE CHALLENGE AS THE NEARLY STATIONARY BOUNDARY PERSISTS OVER THE STATE. A FEW VERY LIGHT SHOWERS REMAIN FROM CITRUS COUNTY SOUTHWARD THROUGH HILLSBOROUGH AND POLK. HOWEVER...RADAR RETURNS HAVE BEEN DIMINISHING OVER THE LAST HOUR OR SO AND 12Z HRRR RUN SUGGEST THIS TREND MAY CONTINUE OVER THE COMING HOURS. FOR NOW...WILL LEAVE IN SLIGHT CHANCE FOR POPS ACROSS THE CENTRAL PORTION OF THE CWA AS A LIGHT SHOWER CAN NOT BE RULED OUT. MOST AREAS WILL LIKELY REMAIN DRY UNDER OVERCAST SKIES...THE EXCEPTION BEING FAR SW ZONES WHERE A LITTLE MORE SUNSHINE APPEARS LIKELY LATER TODAY. WILL HAVE TO KEEP AN EYE ON TEMPS ACROSS THE AREA AS CONFIDENCE IS LESS THAN DESIRED FOR THE NEAR TERM. FOR NOW...CURRENT FORECAST LOOKS GOOD WITH ONLY A FEW MINOR ADJUSTMENTS TO TEMPS MADE. && .AVIATION... MVFR TO IFR CONDITIONS OUT THERE THIS MORNING. VICINITY SHOWERS POSSIBLE THROUGH THE DAY TODAY WITH MVFR CEILINGS LIKELY CONTINUING THROUGH THE PERIOD. PATCHY FOG AND IFR CEILINGS LIKELY RETURNING ACROSS THE AREA AFTER 02Z. && .PRELIMINARY POINT TEMPS/POPS... TPA 66 57 66 54 / 40 20 70 20 FMY 80 62 80 60 / 20 10 30 30 GIF 66 57 69 54 / 40 20 50 30 SRQ 68 59 69 55 / 30 20 50 20 BKV 65 54 64 46 / 30 30 80 20 SPG 67 60 67 57 / 40 20 70 20 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/MARINE/FIRE WEATHER...11/MCKAUGHAN AVIATION...24/COLSON
AREA FORECAST DISCUSSION
NWS MIAMI FL
1239 AM EST FRI FEB 7 2014 .AVIATION...IFR WITH LOW CIGS IS EXPECTED TO PREVAIL OVERNIGHT AT KAPF WITH VFR ELSEWHERE. CONDITIONS SHOULD IMPROVE BY MID MORNING AT KAPF. A FEW SHOWERS ARE POSSIBLE NEAR KPBI, ESPECIALLY IN THE AFTERNOON SO INCLUDED VCSH THERE. CALM WINDS WILL BECOME EAST NEAR 5 KT THIS AFTERNOON. /GREGORIA && .PREV DISCUSSION... /ISSUED 907 PM EST THU FEB 6 2014/ UPDATE... CURRENT SATELLITE IMAGERY IS CONSISTENT WITH THE LATEST GUIDANCE INDICATING THE FRONTAL BOUNDARY REMAINING IN THE VICINITY OF LAKE OKEECHOBEE AND LOW LEVEL SOUTHERLY WINDS BRINGING IN DRIER LOW LEVEL AIR FROM THE SOUTH. THE OOZ SOUNDING DID INDICATE THAT THE PWAT HAD DECREASED RELATIVE TO THE 12Z SOUNDING. THERE ARE LINGERING SHOWERS IN THE VICINITY OF THE LAKE AND IS INDICATED IN THE CURRENT FORECAST...BUT EXPECTED TO SLOWLY DISSIPATE LATER THIS EVENING. THE FORECAST INDICATES AREAS OF FOG ACROSS MUCH OF THE PENINSULA AND PATCHY FOG ACROSS THE GULF WATERS EARLY FRIDAY MORNING. THIS SCENARIO IS LOOKING MORE AND MORE LIKELY. LATEST GUIDANCE ALSO INDICATES THAT LOW STRATUS IS LIKELY IN THE VICINITY OF THE LAKE AND INTO THE CENTRAL GULF COAST. A DENSE FOG ADVISORY MAY BE NECESSARY EARLY FRIDAY MORNING ACROSS PORTIONS OF THE PENINSULA. 60 PREV DISCUSSION... /ISSUED 625 PM EST THU FEB 6 2014/ AVIATION... MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE FIRST HALF OF THE FORECAST AND THEN THE ONLY REAL THREAT FOR IFR WILL BE AT KAPF. THE SHORT TERM HIGH RESOLUTION MODELS ARE VERY BULLISH ABOUT DEVELOPING LOW CIGS OVER THE INTERIOR AND ADVECTING ACROSS THE KAPF TERMINAL AFT 05Z AND NOT LIFTING UNTIL AROUND 15Z. CONSIDERING THE TRENDS, CANNOT DENY THIS COULD EASILY HAPPEN. THERE COULD ALSO BE SOME VSBY RESTRICTIONS AT KTMB LATE IN THE PERIOD, BUT CONFIDENCE IS NOT AS HIGH FOR THAT LOCATION. THE SHRA AND ISOLATED TSRA OVER THE INTERIOR THIS EVENING WILL REMAIN OVER THE INTERIOR AND NOT AFFECT ANY OF THE TERMINALS WITH DRIER AIR ALOFT EXPECTED ON FRIDAY. KOB PREV DISCUSSION... /ISSUED 246 PM EST THU FEB 6 2014/ DISCUSSION... STALLED FRONTAL BOUNDARY REMAINED DRAPED ACROSS THE LAKE REGION EARLY THIS AFTERNOON. A FEW SHOWERS WERE ALSO BEGINNING TO DEVELOP ALONG THE BOUNDARY. SCATTERED SHOWERS AND A FEW THUNDERSTORMS REMAIN IN THE FORECAST THROUGH THE AFTERNOON HOURS. A FEW SHOWERS COULD LINGER INTO THE OVERNIGHT HOURS ACROSS THE INTERIOR AND PALM BEACH COUNTY. LOW CEILINGS AND FOG IS EXPECTED AGAIN TONIGHT. SREF IS SHOWING NEAR 100 PERCENT PROBABILITY OF CEILINGS BELOW 1000FT FROM SOUTH OF NAPLES AND ACROSS GLADES AND HENDRY COUNTIES. DENSE SEA FOG IS POSSIBLE AGAIN THIS EVENING OVER THE GULF WATERS...THEN AFTER MIDNIGHT WINDS ARE EXPECTED TO INCREASE OUT OF THE NORTHEAST AND THAT SHOULD PUT AN END TO THE FOG THERE. SOME GUIDANCE SUGGESTS THAT FOG COULD DEVELOP ACROSS THE INTERIOR AND THEN PUSH INTO THE METRO AREAS LATE TONIGHT AS THE BOUNDARY LAYER WINDS SHIFT TO THE WEST. SO PUSHED THE PATCHY FOG CHANCE TO THE COAST AND AREAS OF FOG INTO THE METRO AREAS FOR TONIGHT. DENSE FOG IS ALSO POSSIBLE. THE FRONTAL BOUNDARY IS FORECAST TO LIFT SLOWLY BACK NORTHWARD ON FRIDAY AS A WARM FRONT. SOME SLIGHT DRYING IS FORECAST TO TAKE PLACE IN THE LOW LEVELS ON FRIDAY...BEFORE DEEPER MOISTURE SURGES BACK INTO THE REGION FRIDAY NIGHT INTO SATURDAY. AN AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ALONG THE FRONTAL BOUNDARY OFF OF THE EAST CENTRAL FLORIDA COAST FRIDAY NIGHT INTO SATURDAY. THIS LOW WILL THEN MOVE OFF TO THE NORTHEAST THROUGH THE WEEKEND. THIS WILL FORCE THE FRONTAL BOUNDARY BACK SOUTH...AND INCREASE RAIN CHANCES ON SATURDAY AND INTO SUNDAY. THE FRONT IS THEN FORECAST TO PUSH SOUTH OF THE REGION BY SUNDAY EVENING...WITH DRIER AIR PUSHING INTO SOUTH FLORIDA. IT WILL BE WARM THIS WEEKEND WITH HIGHS IN THE 80S AND HEAT INDICES NEARING 90. HIGH TEMPERATURES WILL NOT BE AFFECTED EARLY NEXT WEEK BY THE FRONTAL PASSAGE...BUT DEWPOINTS WILL DROP 5-10 DEGREES AND OVERNIGHT LOWS WILL BE SEVERAL DEGREES COOLER. THE DRY AND COMFORTABLE WEATHER WILL NOT LAST LONG. ANOTHER AREA OF LOW PRESSURE WILL DEVELOP OVER THE NORTHWESTERN GULF OF MEXICO AND MOVE NORTHEAST ACROSS THE SOUTHEASTERN UNITED STATES BY THE MIDDLE OF NEXT WEEK. IN TURN...MOISTURE WILL THEN INCREASE AGAIN FROM THE SOUTH. AVIATION... A COLD FRONT STALLED ACROSS THE AREA WILL CONTINUE TO INFLUENCE THE LOCAL WEATHER THROUGH THE 24 HR TAF PERIOD...MAINLY FOR REDUCED CIGS AND VSBYS AT SITE APF AND INCREASED SHOWER/TSTM CHANCES AROUND PBI. THE LATEST HRRR AND WRF MODEL REFLECTIVITIES INDICATE THE BEST RAIN CHANCES SETTING UP ACROSS THE INTERIOR AND NORTHERN LOCATIONS FROM THE LAKE TO THE PALM BEACHES THROUGH THE AFTERNOON HOURS TODAY. ALTHOUGH THE BULK OF THIS ACTIVITY SHOULD REMAIN JUST INLAND OF THE PBI SITE...ANY EWD SHIFT TOWARD THE COAST THROUGH THE LATE AFTERNOON/EARLY EVENING HOURS COULD RESULT IN REDUCED VSBYS/CIGS IN AND AROUND ANY ACTIVITY. SIMILAR TO THIS MORNING AND THROUGH THE OVERNIGHT HOURS LAST NIGHT...CIGS/VSBYS DUE FOG WILL BECOME THE MAIN CONCERN...MAINLY FOR SITE APF AND POSSIBLY TMB. THIS MAY LINGER THROUGH THE MID-MORNING HOURS FRIDAY BEFORE BURNING OFF OR LIFTING. 85/AG MARINE... THE WINDS WILL REMAIN BELOW 10 KNOTS THROUGH THIS WEEKEND...EXCEPT OVER THE GULF WATERS TONIGHT WHERE WINDS WILL INCREASE TO 10-15 KNOTS. THIS WILL KEEP THE SEAS 4 FEET OR LESS THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 68 83 68 83 / 10 30 40 20 FORT LAUDERDALE 72 80 69 83 / 10 30 40 20 MIAMI 71 83 69 84 / 10 30 30 20 NAPLES 66 81 66 81 / 10 20 20 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS BOISE ID
924 PM MST THU FEB 6 2014 .DISCUSSION...WATER VAPOR SATELLITE PICS SHOWING A DISTINCT SHORT WAVE TROUGH MOVING INTO CENTRAL OREGON THIS EVENING. BOTH THE 00Z GFS AND NAM SOLUTIONS INITIATED WELL WITH PLACEMENT OF THE UPPER DYNAMICS OF THIS SYSTEM AND TRACK IT ALONG THE WA/OR BORDER OVERNIGHT. MODELS...INCLUDING THE HIGHER RESOLUTION HRRR ARE FAIRLY CLOSE IN QPF AMOUNTS FOR TONIGHT. MADE SOME MINOR ADJUSTMENTS TO PRECIP/SNOW AMOUNTS MOSTLY ON THE FRONT AND BACK ENDS AS THE SNOW DEVELOPMENT IS A BIT DELAYED ACROSS SW IDAHO ZONES AND WILL LIKELY END ACROSS THE LOWER SNAKE RIVER PLAIN BY 5AM MST FRIDAY MORNING...WHILE CONTINUING THROUGH MID-DAY IN THE WESTERN MAGIC VALLEY. THAT SAID STILL LOOKING AT 1-2 INCHES IN THE TREASURE VALLEY OVERNIGHT WITH 1 TO 3 IN THE WESTERN MAGIC VALLEY BY NOON FRIDAY. NO CHANGES TO CURRENT HEADLINES OR LONG TERM ACCUMULATION AMOUNTS. && .AVIATION...WIDESPREAD MOUNTAIN OBSCURATION. MVFR/IFR SNOW ACROSS SOUTHEAST WILL SPREAD INTO SOUTHWEST IDAHO BY MIDNIGHT TONIGHT. SNOW IS EXPECTED TO END BY 12Z EXCEPT IN THE CENTRAL MOUNTAINS OF IDAHO WHICH COULD LAST THROUGH EARLY FRIDAY AFTERNOON. THERE WILL BE A BREAK IN THE SNOW FRIDAY...BUT EXPECT DETERIORATING CEILINGS AND VISIBILITIES LATE FRIDAY NIGHT AS ANOTHER WARM FRONT MOVES ACROSS THE REGION FOR MORE IFR-MVFR SNOW. SNOW IS EXPECTED TO END SATURDAY MORNING EXCEPT IN THE CENTRAL MOUNTAINS. SURFACE WINDS...EAST TO SOUTHWEST 10-20 KTS BECOMING WEST-SOUTHWEST WITH THE FRONTAL PASSAGE. WINDS ALOFT...WEST AROUND 40 KTS AT 10K FT MSL. && .PREV DISCUSSION... SHORT TERM...TONIGHT THROUGH SATURDAY...FORECAST LARGELY UNCHANGED THROUGH SATURDAY. WE HAVE UPGRADED THE ADVISORIES FOR PARTS OF THE AREA UP TO A WARNING BECAUSE OF THE LONG DURATION COMBINED WITH THE SNOW AMOUNTS AND ALSO BECAUSE THERE WILL BE SOME BLOWING AND DRIFTING OF THE SNOW. THE WARNINGS EXTEND FROM SOUTHEAST OREGON THROUGH THE SOUTHWEST HIGHLANDS AND INTO THE WESTERN MAGIC VALLEY AND SOUTHERN TWIN FALLS COUNTY. ADVISORIES STILL COVER THE TREASURE VALLEY AND POINTS NORTH AND NORTHWEST. THE MAIN THING TO KNOW ABOUT THIS IS THAT THERE WILL BE TWO MAIN PERIODS OF HEAVIER SNOW...ONE TONIGHT AS AN INITIAL WARM FRONT MOVES THROUGH...AND A SECOND ONE TOMORROW NIGHT INTO EARLY SATURDAY AS A SECOND...STRONGER...WARM FRONT MOVES THROUGH. IN ADDITION... A COLD FRONT WILL MOVE THROUGH FRIDAY...ADDING MORE SNOW TO THE TOTAL. WINDS WILL GUST ABOVE 25 MPH ACROSS THE SOUTHERN TIER OF THE CWA...ESPECIALLY IN THE HIGHER ELEVATIONS. THIS WILL RESULT IN AREAS OF BLOWING AND DRIFTING SNOW. THE DRIFTING SNOW MAKES IT DIFFICULT IF NOT IMPOSSIBLE FOR ROAD CREWS TO KEEP THE ROADS CLEAR. THIS IS ANOTHER REASON TO UPGRADE FROM ADVISORY TO WARNING. TEMPS THROUGH THE PERIOD WILL BE WELL BELOW NORMAL AND WELL BELOW GUIDANCE. TEMPS HAVE BARELY RISEN OVER MUCH OF THE AREA TODAY DUE TO A COMBINATION OF LOW LEVEL COLD ADVECTION OF THE ARCTIC AIR THAT HAS SQUEEZED THROUGH THE PASSES AND MOVED WESTWARD THROUGH ROCKIES AND INTO OUR AREA...SNOW ON THE GROUND...AND ADDITIONAL LIGHT SNOWFALL. WE HAVE GONE WELL BELOW GUIDANCE AGAIN TOMORROW...EVEN AFTER TONIGHT/S WARM FRONT... BETTING THE SAME BASIC THING WILL HAPPEN. ON SATURDAY...AFTER THE SECOND WARM FRONT MOVES THROUGH...TEMPS COULD THEORETICALLY WARM INTO THE MID 40S ACROSS THE SOUTHERN PORTION OF THE CWA. HOWEVER...WE DID NOT PUT THIS IN THE FORECAST BECAUSE WE BELIEVE THAT THE SNOW ON THE GROUND WILL INHIBIT WARMING. OVERNIGHT LOWS WILL CONTINUE TO REACH WELL BELOW NORMAL AS WELL...EVEN THOUGH THERE IS PLENTY OF CLOUD COVER. POPS WERE RAISED AS CONFIDENCE IN THE WIDESPREAD NATURE OF THE PRECIP EVENT IS EXTREMELY HIGH NOW. SOME LOCATIONS WILL SEE BREAKS IN THE PRECIP FROM TIME TO TIME...ESPECIALLY DURING THE DAY FRIDAY...BUT OVERALL MOST FOLKS WILL SEE SNOW FOR AT LEAST A FEW HOURS WITHIN EACH DAY/NIGHT PERIOD IN THE SHORT TERM FORECAST. FINALLY...THE TIMING OF THE WARMING SATURDAY AFTERNOON ACROSS THE SOUTH IS IMPORTANT. WE HAVE SNOW CHANGING TO A MIX OR TO ALL RAIN DURING THE AFTERNOON. THE LONGER IT TAKES FOR THIS TO HAPPEN...THE MORE SNOW WILL PILE UP BEFORE IT STARTS TO BE EATEN AWAY BY THE RAIN. EVEN AFTER IT CHANGES TO RAIN...FOR MANY BACK ROADS THE ONLY CHANGE WILL BE FROM SNOW AND ICE...TO WATER-COVERED ICE...WHICH IS MANY TIMES EVEN MORE SLICK. BE SAFE OUT THERE. LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...ZONAL FLOW WILL CONTINUE TO TRANSPORT MILD MOIST PACIFIC AIR INLAND OVER THE INTERMOUNTAIN REGION FOR UNSETTLED WEATHER THROUGH THE PERIOD. MODELS AGREE ON THE OVERALL PATTERN. THE GFS HAS BEEN THE LEAST CONSISTENT ON TIMING INDIVIDUAL FEATURES...SO OUR FORECAST RELIES ON BLENDS WEIGHTED TOWARD THE EUROPEAN MODELS. THE BEST CHANCE OF MORE SNOW IS STILL SATURDAY NIGHT THROUGH SUNDAY MORNING. ONLY LIGHT AMOUNTS ARE ANTICIPATED IN THE VALLEYS...BUT THE MOUNTAINS COULD SEE 2-4 INCHES ADDITIONAL ACCUMULATIONS. PRECIPITATION IN THE VALLEYS WILL CHANGE TO A MIX OF SNOW AND RAIN SUNDAY AFTERNOON. SHORTWAVE RIDGING ON MONDAY WILL PROVIDE A BRIEF BREAK BEFORE PRECIPITATION CHANCES INCREASE AGAIN TUESDAY THROUGH THURSDAY. TEMPERATURES WILL AVERAGE NEAR NORMAL. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...WINTER STORM WARNING UNTIL 5 PM MST SATURDAY IDZ015-016-029-030. WINTER WEATHER ADVISORY UNTIL 5 PM MST SATURDAY IDZ011>014-028-033. OR...WINTER STORM WARNING UNTIL 5 PM MST /4 PM PST/ SATURDAY ORZ061-063. WINTER WEATHER ADVISORY UNTIL 5 PM MST SATURDAY ORZ064. WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY ORZ062. && $$ WEATHER.GOV/BOISE DISCUSSION...DG AVIATION.....JS PREV SHORT TERM...SP PREV LONG TERM....JT/TB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
832 PM CST SAT FEB 8 2014 .UPDATE... ISSUED AT 830 PM CST SAT FEB 8 2014 PREVIOUS THINKING STILL APPEARS ON TRACK FOR THE MOST PART BUT HAVE TRIMMED SNOW AMOUNTS AND POPS INTO CENTRAL IA AS DRY AIR APPEARS TO BE REDUCING NRN EXTENT. THIS EFFECTIVELY ELIMINATES MENTION IN IMMEDIATE DES MOINES AREA...ALTHOUGH SNOW IS IN PROGRESS JUST TO THE SOUTH IN WARREN CO. UPDATE ISSUED AT 629 PM CST SAT FEB 8 2014 LATEST HI RES MODEL GUIDANCE AND UPSTREAM TRENDS SUGGEST RAISING POPS TONIGHT SO NOW HAVE CATEGORICAL WORDING GOING SOUTH VS LIKELIES. ALSO NUDGED SNOW AMOUNTS UP A BIT BASED ON HIGHER RATIOS BUT THE SAME QPF. 18Z NAM/GFS COBB OUTPUT SUGGESTS AT LEAST UPPER TEENS. MORNING RATIOS WERE 20 TO 30:1...HIGHER IN SPOTS...SO CANNOT SEE CONDITIONS CHANGING THAT MUCH IN THAT SHORT OF TIME. 12Z HOPWRF RUNS AND LATEST RAP POINTED TOWARD HIGHER AMOUNTS AS WELL. STATIC STABILITY IS SOMEWHAT LOWER TOO SO FULLY EXPECT HIGHER AMOUNTS TO BE LOCALIZED. DUE TO THE RELATIVELY NARROW NATURE OF THE SNOW BAND...FULLY EXPECT FORECAST ERRORS ON THE HIGH AND LOW END OF THINGS. TEKAMAH VISIBILITIES WERE LOCALLY DOWN TO A HALF MILE FOR INSTANCE WITH SURROUND SITES STILL AT SEVERAL MILES. && .SHORT TERM /TONIGHT/... ISSUED AT 329 PM CST SAT FEB 8 2014 A FEW PATCHES OF LIGHT SNOW LINGERING THIS AFTERNOON IN THE WAKE OF AN IMPRESSIVE AND COMPACT SHORT WAVE THAT MOVED THROUGH THIS MORNING. ANOTHER SHORTWAVE IS NOW MOVING SOUTHEAST AND INTO WESTERN SOUTH DAKOTA. A RIBBON OF THERMODYNAMIC FORCING DEVELOPS AHEAD OF THE SHORTWAVE WITH AN INCREASING THERMAL GRADIENT DEVELOPING AROUND 700 MB. A BAND OF LIGHT SNOW SHOULD DEVELOP ALONG THIS BAND AS FORCING FROM THE SHORT WAVE ARRIVES. SHOULD HAVE AN AREA OF ACCUMULATING LIGHT SNOW WITH GENERALLY AN INCH OR LESS POSSIBLE ALONG AND SOUTH OF HIGHWAY 30. WITH THE PRIMARY FORCING FOCUSED IN THE -17C TO -25C RANGE AND SATURATION NOT COMPLETE...MAY HAVE DENDRITES DEVELOP BUT THE PRIMARY FLAKES WILL BE LOWER SNOW RATIO SMALL PLATES. THE ARCTIC AIR WILL AGAIN SPILL INTO THE STATE LATE. CLOUD COVER SHOULD KEEP MOST LOCATIONS ABOVE GUIDANCE VALUES. TEMPERATURES WILL FALL BELOW ZERO OVER THE NORTH AND COMBINED WITH NORTHWEST WINDS NEAR 10 MPH...WILL PUSH WIND CHILL VALUES TO 20 TO 25 BELOW ZERO THERE. WILL ISSUE WIND CHILL HEADLINES FOR THE FAR NORTH. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 329 PM CST SAT FEB 8 2014 THE NEXT SEVERAL DAYS WILL BE MARKED BY QUIET BUT VERY COLD WEATHER AS A LARGE HIGH PRESSURE CENTER MOVING DOWN FROM CANADA BUILDS ACROSS THE AREA. THE LIGHT SNOW EXPECTED TONIGHT...AS DISCUSSED ABOVE...MAY LINGER ACROSS FAR SOUTHERN IOWA ON SUNDAY BUT VERY LITTLE ACCUMULATION IS ANTICIPATED AND ONLY DOWN NEAR THE MISSOURI BORDER. THE BIGGER WEATHER STORY WILL BE THE POLAR AIR STREAMING IN FROM THE NORTHWEST...KEEPING TEMPERATURES DOWN IN THE SINGLE DIGITS AND LOWER TEENS DURING THE DAY THROUGH TUESDAY WITH MORNING LOWS FAR BELOW ZERO EACH DAY. THIS WILL RESULT IN DANGEROUSLY COLD WIND CHILLS ON MONDAY MORNING AND AN EXTENSIVE HEADLINE MAY BE NEEDED IN THE FUTURE TO COVER THIS THREAT. LATE ON TUESDAY THE LARGE HIGH PRESSURE CENTER WILL FINALLY MOVE OFF TO THE EAST...ALLOWING FOR A BRIEF RETURN OF SOUTHERLY FLOW AND MILDER TEMPERATURES AND USHERING IN A CHANGE IN THE OVERALL WEATHER PATTERN. THE NEW PATTERN WILL BE CHARACTERIZED BY WEST NORTHWEST FLOW ALOFT...THROUGH WHICH A SERIES OF COMPACT BUT FAIRLY ROBUST 500 MB TROUGHS WILL QUICKLY MOVE ACROSS THE REGION BETWEEN WEDNESDAY AND FRIDAY. THESE SYSTEMS WILL CAUSE WINDS TO TURN FROM SOUTH TO NORTHWEST AND BACK AGAIN EACH DAY...KEEPING TEMPERATURES MODERATE AND PROVIDING INTERMITTENT CHANCES FOR LIGHT SNOW ACCUMULATIONS PARTICULARLY ACROSS THE NORTHEAST AND EAST. FOR NOW IT IS VIRTUALLY IMPOSSIBLE TO PIN DOWN THE PRECISE TIMING OF ANY SNOW THAT WILL FALL...AS THESE QUICKLY MOVING SYSTEMS ARE DIFFICULT TO FORECAST THAT EXACTLY SO MANY DAYS OUT...BUT IT DOES NOT APPEAR THAT THERE IS MUCH THREAT FOR SIGNIFICANT SNOWFALL. && .AVIATION...09/00Z ISSUED AT 629 PM CST SAT FEB 8 2014 PRIMARY CONCERN WILL BE BAND OF SNOW AFFECTING KDSM/KOTM TONIGHT. EXPECT AT LEAST MVFR CONDITIONS WITH PERIODS OF IFR LIKELY FOR A PERIOD JUST SOUTH OF KDSM TOWARD KOTM. COULD EVEN SEE LOWER BRIEFLY BUT CONFIDENCE NOT THERE TO INJECT AS OF YET. SNOW SHOULD THEN END AROUND 09Z WITH VFR CONDITIONS RETURNING AREA WIDE. WINDS WILL CHANGE LITTLE INTO SUN...ESSENTIALLY REMAINING NLY. && .DMX WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FROM 3 AM TO 11 AM CST SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-POCAHONTAS-WINNEBAGO-WORTH. && $$ UPDATE...SMALL SHORT TERM...DONAVON LONG TERM...LEE AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
630 PM CST SAT FEB 8 2014 .UPDATE... ISSUED AT 629 PM CST SAT FEB 8 2014 LATEST HI RES MODEL GUIDANCE AND UPSTREAM TRENDS SUGGEST RAISING POPS TONIGHT SO NOW HAVE CATEGORICAL WORDING GOING SOUTH VS LIKELIES. ALSO NUDGED SNOW AMOUNTS UP A BIT BASED ON HIGHER RATIOS BUT THE SAME QPF. 18Z NAM/GFS COBB OUTPUT SUGGESTS AT LEAST UPPER TEENS. MORNING RATIOS WERE 20 TO 30:1...HIGHER IN SPOTS...SO CANNOT SEE CONDITIONS CHANGING THAT MUCH IN THAT SHORT OF TIME. 12Z HOPWRF RUNS AND LATEST RAP POINTED TOWARD HIGHER AMOUNTS AS WELL. STATIC STABILITY IS SOMEWHAT LOWER TOO SO FULLY EXPECT HIGHER AMOUNTS TO BE LOCALIZED. DUE TO THE RELATIVELY NARROW NATURE OF THE SNOW BAND...FULLY EXPECT FORECAST ERRORS ON THE HIGH AND LOW END OF THINGS. TEKAMAH VISIBILITIES WERE LOCALLY DOWN TO A HALF MILE FOR INSTANCE WITH SURROUND SITES STILL AT SEVERAL MILES. && .SHORT TERM /TONIGHT/... ISSUED AT 329 PM CST SAT FEB 8 2014 A FEW PATCHES OF LIGHT SNOW LINGERING THIS AFTERNOON IN THE WAKE OF AN IMPRESSIVE AND COMPACT SHORT WAVE THAT MOVED THROUGH THIS MORNING. ANOTHER SHORTWAVE IS NOW MOVING SOUTHEAST AND INTO WESTERN SOUTH DAKOTA. A RIBBON OF THERMODYNAMIC FORCING DEVELOPS AHEAD OF THE SHORTWAVE WITH AN INCREASING THERMAL GRADIENT DEVELOPING AROUND 700 MB. A BAND OF LIGHT SNOW SHOULD DEVELOP ALONG THIS BAND AS FORCING FROM THE SHORT WAVE ARRIVES. SHOULD HAVE AN AREA OF ACCUMULATING LIGHT SNOW WITH GENERALLY AN INCH OR LESS POSSIBLE ALONG AND SOUTH OF HIGHWAY 30. WITH THE PRIMARY FORCING FOCUSED IN THE -17C TO -25C RANGE AND SATURATION NOT COMPLETE...MAY HAVE DENDRITES DEVELOP BUT THE PRIMARY FLAKES WILL BE LOWER SNOW RATIO SMALL PLATES. THE ARCTIC AIR WILL AGAIN SPILL INTO THE STATE LATE. CLOUD COVER SHOULD KEEP MOST LOCATIONS ABOVE GUIDANCE VALUES. TEMPERATURES WILL FALL BELOW ZERO OVER THE NORTH AND COMBINED WITH NORTHWEST WINDS NEAR 10 MPH...WILL PUSH WIND CHILL VALUES TO 20 TO 25 BELOW ZERO THERE. WILL ISSUE WIND CHILL HEADLINES FOR THE FAR NORTH. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 329 PM CST SAT FEB 8 2014 THE NEXT SEVERAL DAYS WILL BE MARKED BY QUIET BUT VERY COLD WEATHER AS A LARGE HIGH PRESSURE CENTER MOVING DOWN FROM CANADA BUILDS ACROSS THE AREA. THE LIGHT SNOW EXPECTED TONIGHT...AS DISCUSSED ABOVE...MAY LINGER ACROSS FAR SOUTHERN IOWA ON SUNDAY BUT VERY LITTLE ACCUMULATION IS ANTICIPATED AND ONLY DOWN NEAR THE MISSOURI BORDER. THE BIGGER WEATHER STORY WILL BE THE POLAR AIR STREAMING IN FROM THE NORTHWEST...KEEPING TEMPERATURES DOWN IN THE SINGLE DIGITS AND LOWER TEENS DURING THE DAY THROUGH TUESDAY WITH MORNING LOWS FAR BELOW ZERO EACH DAY. THIS WILL RESULT IN DANGEROUSLY COLD WIND CHILLS ON MONDAY MORNING AND AN EXTENSIVE HEADLINE MAY BE NEEDED IN THE FUTURE TO COVER THIS THREAT. LATE ON TUESDAY THE LARGE HIGH PRESSURE CENTER WILL FINALLY MOVE OFF TO THE EAST...ALLOWING FOR A BRIEF RETURN OF SOUTHERLY FLOW AND MILDER TEMPERATURES AND USHERING IN A CHANGE IN THE OVERALL WEATHER PATTERN. THE NEW PATTERN WILL BE CHARACTERIZED BY WEST NORTHWEST FLOW ALOFT...THROUGH WHICH A SERIES OF COMPACT BUT FAIRLY ROBUST 500 MB TROUGHS WILL QUICKLY MOVE ACROSS THE REGION BETWEEN WEDNESDAY AND FRIDAY. THESE SYSTEMS WILL CAUSE WINDS TO TURN FROM SOUTH TO NORTHWEST AND BACK AGAIN EACH DAY...KEEPING TEMPERATURES MODERATE AND PROVIDING INTERMITTENT CHANCES FOR LIGHT SNOW ACCUMULATIONS PARTICULARLY ACROSS THE NORTHEAST AND EAST. FOR NOW IT IS VIRTUALLY IMPOSSIBLE TO PIN DOWN THE PRECISE TIMING OF ANY SNOW THAT WILL FALL...AS THESE QUICKLY MOVING SYSTEMS ARE DIFFICULT TO FORECAST THAT EXACTLY SO MANY DAYS OUT...BUT IT DOES NOT APPEAR THAT THERE IS MUCH THREAT FOR SIGNIFICANT SNOWFALL. && .AVIATION...09/00Z ISSUED AT 629 PM CST SAT FEB 8 2014 PRIMARY CONCERN WILL BE BAND OF SNOW AFFECTING KDSM/KOTM TONIGHT. EXPECT AT LEAST MVFR CONDITIONS WITH PERIODS OF IFR LIKELY FOR A PERIOD JUST SOUTH OF KDSM TOWARD KOTM. COULD EVEN SEE LOWER BRIEFLY BUT CONFIDENCE NOT THERE TO INJECT AS OF YET. SNOW SHOULD THEN END AROUND 09Z WITH VFR CONDITIONS RETURNING AREA WIDE. WINDS WILL CHANGE LITTLE INTO SUN...ESSENTIALLY REMAINING NLY. && .DMX WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FROM 3 AM TO 11 AM CST SUNDAY FOR CERRO GORDO-EMMET-HANCOCK-KOSSUTH-PALO ALTO-POCAHONTAS-WINNEBAGO-WORTH. && $$ UPDATE...SMALL SHORT TERM...DONAVON LONG TERM...LEE AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
547 PM CST Sat Feb 8 2014 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Sunday) Issued at 327 PM CST SAT FEB 8 2014 This afternoon a longer wave length upper level trough was located across the upper Midwest and Northern Great Lakes. The mid and upper level flow across the plains was from the northwest. A minor upper level trough over west central Canada and MT will dig southeast across the plains on Sunday. Low-level CAA across the northern plains will cause a cold front to push southward across the CWA later tonight. Ahead of the front there may be enough isentropic lift at the 280K surface for some light flurries or light patchy freezing drizzle. I only kept a slight chance since condensation pressure deficits on the 280K surface will increase and the layer may dry enough to prevent freezing drizzle from reaching the surface. Overnight lows will occur around sunrise after the colder airmass moves south across the CWA. Sunday, stronger ascent ahead of the H5 trough moving southeast across the central plains will cause light snow to develop from northwest to southeast across the CWA. Both the 12Z NAM and 12Z ECMWF show the greater chances for snowfall across the the northern counties of the CWA where perhaps up to an inch of snow may fall through the day. Along and south of I-70 only occasional show showers are expected with perhaps a dusting of snowfall. The 12Z GFS model had the higher QPF across the central portions of the CWA. Highs behind the cold front will be colder than Today`s highs, as a 1036 MB surface ridge axis builds southward across the CWA by late afternoon. The snow should end across north central KS by the late afternoon hours. North winds will increase to 15 to 20 MPH with gusts of 25 to 30 MPH during the mid morning hours and last into the afternoon, so there may be some blowing and drifting of the snow already on the ground. Highs will only reach the mid teens across the northern counties to the lower to mid 20s across east central KS. Temperatures across the southeast counties will probably hold steady if not slowly fall through the day. .LONG TERM...(Sunday Night through Saturday) Issued at 327 PM CST SAT FEB 8 2014 By Sunday night, a mid-level trough will be centered over the Great Lakes region, with northwesterly flow over the Central Plains. Models continue to show the potential for a few very weak embedded waves to develop within this flow Sunday night into Monday. One of these waves should be just east of the area by Sunday night, however some models have trended a little slower with this wave in which some light precipitation may potentially linger over far eastern Kansas early in the evening, so will need to continue watching that feature. Otherwise, a second wave is progged to track southeastward from northwest to southeast Kansas overnight through Monday. The GFS/ECMWF/GEM have trended a bit further south with this wave, having it barely skimming our far southern counties. However the NAM along with the hi-res ARW/NMM have the wave tracking further north, bringing better chances for light snow from north central to east central Kansas. Due to this uncertainty in tracking, still have only slight to chance PoPs in for Sunday night through Monday. Even if this wave ends up tracking further north and clipping parts of the forecast area, there doesn`t seem to be much lift available to support decent snow development. In fact, have kept QPF values low with upwards of 0.5 to near 1 inch of snow possible over central to east central Kansas Sunday night through Monday. With the surface high pressure centered over the Northern Plains spilling southward into the Central Plain, temperatures will remain cool with lows Sunday night in the single digits and Monday highs only reaching into the teens with northeasterly winds and mostly cloudy skies in place. Monday night through Wednesday this surface high will gradually shift toward the southeastern U.S. The center of the high looks to pass just east of the area Tuesday morning, and models continue to vary greatly in just how cold surface temperatures will get as the surface high strengthens. The ECMWF remains noticeably colder (like yesterday`s 12z run), however today the GEM 12z run has gone even colder than the ECMWF. Still not confident in this extreme cold actually occurring even though a decent snow pack will still be in place and skies will begin to clear by Tuesday morning. At the same time, feel the GFS still may be a bit too warm, so have trended closer to the NAM with Tuesday morning low temperatures which puts the region near the 0 degree mark. This colder trend in temperatures in the ECMWF/GEM continues through Tuesday, but with winds shifting to the southwest due to the surface high tracking southeast of the area, feel that high temperatures should be able to reach into the low/mid 20s. Models are in agreement that the pressure gradient should increase over the region Tuesday night into Wednesday, resulting in increased southwesterly flow and better waa into the region. This waa combined with mostly clear skies should help to boost lows Tuesday night into the teens and Wednesday highs into the 30s. However, with several inches of snow still on the ground, we will have to monitor how the melting snow affects temperatures through the latter part of the week. Models continue to be very inconsistent for the latter part of the week into the weekend with the tracking of the next couple of systems. Models are in agreement in showing an area of low pressure tracking eastward over the Northern Plains toward the Great Lakes region with an associated cold front extending southward and tracking across the area. The GFS remains the fastest in bringing the front through Thursday morning, but the ECMWF/GEM have the front moving in faster than previous runs, bringing it through Thursday afternoon and evening. A second surface low follows a very similar track across the Northern Plains Friday into Saturday with another cold front expected to move through the region, but this time the ECMWF is faster than the GFS. With these timing differences in the frontal passages, confidence remains low for the temperature/wind forecast towards the end of the week into the weekend. There doesn`t look to be much available moisture with these frontal passages, with only the ECMWF ramping up precip along the second front as it exits the region. Removed the mention of slight PoPs that the consensus blend had for eastern Kansas Friday night due to the model uncertainty. While the temperature forecast is a bit uncertain, the temperature trends within the models show that there shouldn`t be much cold air moving in behind these fronts. In fact, could see temperatures moderating into the 40s by the end of the week, which will certainly aid in melting the snow across the region. && .AVIATION...(For the 00Z TAFs through 00Z Sunday Evening) Issued at 547 PM CST SAT FEB 8 2014 Some limitations should rule this forecast, and IFR to even lower conditions possible. Weak SW winds ahead of cold front bringing better low level moisture into the terminals. This along with diurnal trends should allow cigs to drop to IFR in the next few hours. NAM and RAP similar with area of near-surface moisture convergence along and behind approaching front and could see FZDZ result around 06Z. Believe this will clear out a bit by 10Z as drier air moves in. Of course the deep snow on the ground makes boundary layer forecasts tricky. Next wave may produce -SN late in the forecast. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...Hennecke AVIATION...65
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1008 AM MST FRI FEB 7 2014 .UPDATE... ISSUED AT 959 AM MST FRI FEB 7 2014 UPDATE TO LET THE WIND CHILL ADVISORY EXPIRE. WIND CHILL READINGS HAVE IMPROVED ACROSS THE TRI STATE AREA...AND ARE NOT EXPECTED TO BECOME A PROBLEM FOR TONIGHT. && .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 402 AM MST FRI FEB 7 2014 FORECAST CONCERNS WILL BE THE CHANCE OF PRECIPITATION INTO THE WEEKEND AND WHAT TO DO WITH THE TEMPERATURES...ESPECIALLY THE HIGH TEMPERATURES. SATELLITE SHOWING A VERY BLOCKY AND AMPLIFIED FLOW OVER THE PACIFIC TO ALONG THE WEST COAST OF NORTH AMERICA. THIS TRANSITIONS TO BROAD TROUGHINESS AND FAST WESTERLY FLOW OVER THE COUNTRY. SYSTEM OVER THE NORTH CENTRAL PORTION OF THE COUNTRY IS MOVING EAST. TWO STRONGER SOUTHERN STREAM SHORTWAVES ARE OVER THE DESERT SOUTHWEST AND EASTERN NEW MEXICO/WESTERN TEXAS. LOW LEVEL AIR MASS HAS MODIFIED SOME BUT IS STILL COLD AND MOIST. AT JET LEVEL...MODELS INITIALIZED FINE AT JET LEVEL. AT MID LEVELS... THE GFS...UKMET...CANADIAN AND ECMWF DID THE BEST. THE ECMWF WAS DOING BEST ON THE SURFACE WIND AND PRESSURE FIELD. THE ECMWF WAS DOING A LITTLE BETTER THAN THE GFS ON THE LOW LEVEL THERMAL FIELD. THIS WILL BE A LOW CONFIDENCE FORECAST FOR A COUPLE OF REASONS. FIRST THE MODELS...EVEN THE MESOSCALE ONES...HAVING A HARD TIME THIS MORNING RESOLVING LOW LEVEL MOISTURE AND TEMPERATURE AT THE BEGINNING OF THIS PERIOD. SECOND IS THE MODELS DIFFERENCE IN HANDLING UPPER JET FEATURES AND SURFACE/LOW LEVEL THERMAL FIELD THIS WEEKEND. TODAY/TONIGHT...IN REGARDS TO CURRENT WIND CHILL ADVISORY. THE WESTERN AND NORTHERN FRINGES OF THE HIGHLIGHT HAVE VERIFIED WITH THE REMAINING AREA NOT THAT FAR AWAY. CLOUD COVER WILL NOT LET TEMPERATURES DROP MUCH MORE WITH THE EXCEPTION OF THE FAR WEST WHICH HAS BEEN CLEAR FOR ALMOST THE ENTIRE NIGHT. AM NOT OPTIMISTIC ABOUT MUCH MORE OF THE ADVISORY VERIFYING BUT ANY SMALL SHIFT OF THE WINDS AND TEMPERATURES IN THE RIGHT DIRECTION WILL CAUSE WIND CHILL ADVISORY CRITERIA TO BE REACHED. RIGHT REAR QUADRANT OF THE JET IS OVER THE AREA THIS MORNING. THEN A STRONGER LEFT FRONT QUADRANT STARTS AFFECTING THE AREA THIS AFTERNOON. THAT MOVES ACROSS THE AREA DURING THE FIRST HALF OF THE NIGHT. GOING BY 00Z SOUNDINGS AND FORECAST SOUNDINGS...LOW LEVEL AIR MASS IS SATURATED IN THE DENDRITIC ZONE. THAT COMBINED WITH THE JET LIFT IS CAUSING FLURRIES THIS MORNING. ALSO IN THE RETURN FLOW OVER THE WESTERN PORTION OF THE AREA PATCHY FOG HAS DEVELOPED WHICH WAS NOT CAUGHT BY ANYTHING EARLIER BUT NOW THE HRRR HAS RECENTLY CAUGHT ON TO THIS IDEA A LITTLE. SO WILL HAVE FLURRIES AND PATCHY FOG PER REALITY AND 00Z SOUNDINGS FOR THIS MORNING. AM THINKING THE AREA WILL BE CLOUDY TO MOSTLY CLOUDY MOST IF NOT THE ENTIRE DAY WITH MAYBE THE EXCEPTION IN THE FAR WEST. SO TENDED TO COOL MAXES FROM PREVIOUS FORECAST WITH THE EASTERN PORTION BEING THE COLDEST. TRICKY FORECAST FOR TONIGHT. SURFACE TROUGH STARTS MOVING THROUGH EARLY IN THE EVENING WITH WESTERLY WINDS AND CLEARING BEHIND IT. TEMPERATURES WILL NOT RISE MUCH DURING THE DAY SO OVERNIGHT TEMPERATURES WILL HAVE A GOOD START IN DROPPING AND GETTING COLDER. HOWEVER...PRETTY SIGNIFICANT WARM AIR ADVECTION BEHIND THE TROUGH. TENDED TO NOT CHANGE THE MINS VERY MUCH. NEXT THE PREVIOUS FORECAST HAD PATCHY FOG AND DRIZZLE IN ADVANCE OF THE SURFACE TROUGH. SOUNDINGS SHOW MOISTURE IS VERY SHALLOW AHEAD OF THE SURFACE TROUGH. CAN SEE FOG...ESPECIALLY AFTER WHAT HAS HAPPENED THIS MORNING...BUT THINK THE MOISTURE IS TOO SHALLOW FOR FREEZING DRIZZLE. SO REMOVED THAT AND KEPT THE FOG. SATURDAY/SATURDAY NIGHT...MODEL DIFFERENCES REALLY START SHOWING THEMSELVES HEAR. MODELS DIFFER ON THE POSITION AND STRUCTURE OF A COMPLICATED JET WHICH HAS DIFFERENT CONSEQUENCES IN THE FORECAST. AT THIS TIME THE BEST LIFT LOOKS LIKE IT DOES NOT ARRIVE UNTIL THE AFTERNOON IN THE FORM OF A STRONG JET AND PV ANOMALY. MODEL SOUNDINGS ARE SCARCE WITH MOISTURE IN THE LOW LEVELS EVEN IN THE AFTERNOON. CONSIDERING THE TIMING AND DEGREE OF LIFT...REMOVED PRECIPITATION FROM THE MORNING AND KEPT THE PREVIOUS FORECASTS POPS FOR THE AFTERNOON WHICH IS FLURRIES AND SLIGHT CHANCE POPS. THE ABOVE MENTIONED DYNAMICS MOVE THROUGH BY LATE AFTERNOON. ANOTHER SHORTWAVE TROUGH COMES THROUGH DURING THE NIGHT PLUS THE REAL STRONG ARCTIC FRONT MOVES IN THE LAST HALF OF THE NIGHT. SO ALSO KEPT THE NIGHT POPS WHEN CONSIDERING MODEL DIFFERENCES AND UNCERTAINTY BUT THINK POPS MAY BE OVERDONE. SOMETHING ELSE TO WATCH FOR THE NIGHT. CONSIDERING THE AMOUNT OF COLD AIR ADVECTION... PRESSURE GRADIENT...AND INDICATED 3 HOUR PRESSURE RISE...BREEZY AND MORE LIKELY WINDY CONDITIONS COULD DEVELOP. AND IF THAT IS NOT ENOUGH...THERE ARE HUGE DIFFERENCES IN THE TEMPERATURE FORECASTS FOR THE DAY. AS SPECIFIED ABOVE THE ARCTIC BOUNDARY MOVES INTO THE AREA DURING THE NIGHT. HOWEVER...MODELS ARE SHOWING ANOTHER WEAKER BOUNDARY/PRELIMINARY COLD PUSH MOVING INTO THE AREA...ESPECIALLY THE EASTERN AND CENTRAL PORTIONS...DURING THE LATE MORNING AND AFTERNOON HOURS. THE TEMPERATURE FORECAST CAN GO EITHER WAY BUT THE MODELS FOR THE MOST PART HAVE BEEN CONSISTENT IN BRINGING IN THIS COOLER AIR. CONSIDERING WHEN THE SHORTWAVE TROUGH PUSHING THIS FEATURE MOVES THROUGH...LIKE AN EARLIER ARRIVAL OF THE COLD AIR. MADE SLIGHT ADJUSTMENTS ON THE TEMPERATURES AND IN SOME CASES SPLIT THE DIFFERENCE BETWEEN THE EXTREMES. SUNDAY/SUNDAY NIGHT...MOST OF THE MODELS BLAST THE FRONT THROUGH EARLY IN THE DAY WITH A MODEL OR TWO RETREATING THE FRONT AND THEN BRING IT BACK THROUGH OR BRINGING THE FRONT THROUGH SLOWER. AS A RESULT THERE ARE EVEN BIGGER DIFFERENCES IN THE TEMPERATURES FOR THIS DAY. TENDED TO FOLLOW THE CONSENSUS AND WENT COLDER. PRECIPITATION FORECAST ALSO REMAINS UNCERTAIN. OUR AREA TENDS TO REMAIN BETWEEN TWO DIFFERENT JET SEGMENTS FOR MOST OF THE DAY WHEN BY LATE IN THE DAY A COUPLED JET STRUCTURE IS INDICATED. THEN THE BRUNT OF THIS AND OTHER LIFT MOVES THROUGH DURING THE NIGHT. THETA-E LAPSE RATES GET BETTER DURING THE NIGHT AS WELL. SOUNDINGS START MOISTENING UP IN THE AFTERNOON AND REALLY ONLY BECOME SATURATED DURING THE NIGHT. SO BELIEVE THAT THE BEST CHANCE FOR PRECIPITATION WILL BE LATE IN THE AFTERNOON AND ESPECIALLY DURING THE NIGHT ALTHOUGH NEIGHBORS HAVE THE HIGHEST POPS DURING THE DAY. SO MADE TWO ADJUSTMENTS PER REASONING ABOVE. SPLIT SUNDAY POPS INTO A MORNING AND AFTERNOON WITH HIGHER POPS IN THE AFTERNOON. RAISED POPS INTO THE LOW CHANCE CATEGORY FOR THE NIGHT. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 402 AM MST FRI FEB 7 2014 AN UPPER LEVEL SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA DURING THE MONDAY THROUGH TUESDAY TIMEFRAME. MODELS DISAGREE WHEN IT WILL HAPPEN...BUT HAVE BEEN TRENDING THE SHORT WAVE TO THE SOUTHWEST. RIGHT NOW THE WESTERN PART OF THE AREA LOOKS TO HAVE THE BEST SHOT AT RECEIVING SNOW AS THE SHORT WAVE TROUGH MOVES THROUGH. BEHIND THE TROUGH SOUTHERLY 850MB WINDS WILL SPREAD NORTH BRINGING WARMER AIR OVER THE AREA. EVEN IF THE MAJORITY OF THE LIFT IS FURTHER WEST...WITH A SATURATED ENVIRONMENT AND SURFACE TEMPERATURES IN THE DENDRITIC ZONE...AM THINKING FLURRIES ARE A STRONG POSSIBILITY. A SHORT WAVE RIDGE MOVES THROUGH FOLLOWED BY ANOTHER WEDNESDAY...HOWEVER THE TROUGH IS FAIRLY SHALLOW AND DEEPENS EAST OF THE AREA WHERE PRECIP. CHANCES WILL BE MORE LIKELY. OTHERWISE THE LAMINAR NORTHWEST FLOW WILL BE FAIRLY DRY AS THE UPPER LEVEL RIDGE TO THE WEST SLOWLY NUDGES EASTWARD. TEMPERATURES FOR THE PERIOD WILL START OUT AROUND 20 DEGREES BELOW NORMAL. BY WEDNESDAY NEAR NORMAL TEMPERATURES WILL RETURN AS THE COLDER AIR REMAINS OVER THE NORTHERN PLAINS WITH A SHORT WAVE TROUGH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 959 AM MST FRI FEB 7 2014 A BIT OF A MESSY START TO THE TAF PERIOD REGARDING CEILINGS AND VISIBILITIES FOR BOTH TAF SITES. BOTH KMCK AND KGLD ARE EXPERIENCING LOW CEILINGS AND HAZE...WITH OCCASIONAL LIGHT SNOW SHOWERS AND FLURRIES. CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS AFTERNOON WITH VFR VISIBILITIES AND CEILINGS WITH A BREAK IN THE CLOUD COVER. PATCHY FOG COULD DEVELOP TONIGHT FOR BOTH TAF SITES...WHERE MVFR CONDITIONS ARE EXPECTED TO OCCUR WITH LOW MVFR CEILINGS. CONDITIONS WILL IMPROVE TO VFR FOR BOTH TAF SITES FOR TOMORROW MORNING THROUGH 18Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE CO...NONE NE...NONE && $$ UPDATE...MK SHORT TERM...BULLER LONG TERM...JTL AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
445 AM MST FRI FEB 7 2014 .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 402 AM MST FRI FEB 7 2014 FORECAST CONCERNS WILL BE THE CHANCE OF PRECIPITATION INTO THE WEEKEND AND WHAT TO DO WITH THE TEMPERATURES...ESPECIALLY THE HIGH TEMPERATURES. SATELLITE SHOWING A VERY BLOCKY AND AMPLIFIED FLOW OVER THE PACIFIC TO ALONG THE WEST COAST OF NORTH AMERICA. THIS TRANSITIONS TO BROAD TROUGHINESS AND FAST WESTERLY FLOW OVER THE COUNTRY. SYSTEM OVER THE NORTH CENTRAL PORTION OF THE COUNTRY IS MOVING EAST. TWO STRONGER SOUTHERN STREAM SHORTWAVES ARE OVER THE DESERT SOUTHWEST AND EASTERN NEW MEXICO/WESTERN TEXAS. LOW LEVEL AIR MASS HAS MODIFIED SOME BUT IS STILL COLD AND MOIST. AT JET LEVEL...MODELS INITIALIZED FINE AT JET LEVEL. AT MID LEVELS... THE GFS...UKMET...CANADIAN AND ECMWF DID THE BEST. THE ECMWF WAS DOING BEST ON THE SURFACE WIND AND PRESSURE FIELD. THE ECMWF WAS DOING A LITTLE BETTER THAN THE GFS ON THE LOW LEVEL THERMAL FIELD. THIS WILL BE A LOW CONFIDENCE FORECAST FOR A COUPLE OF REASONS. FIRST THE MODELS...EVEN THE MESOSCALE ONES...HAVING A HARD TIME THIS MORNING RESOLVING LOW LEVEL MOISTURE AND TEMPERATURE AT THE BEGINNING OF THIS PERIOD. SECOND IS THE MODELS DIFFERENCE IN HANDLING UPPER JET FEATURES AND SURFACE/LOW LEVEL THERMAL FIELD THIS WEEKEND. TODAY/TONIGHT...IN REGARDS TO CURRENT WIND CHILL ADVISORY. THE WESTERN AND NORTHERN FRINGES OF THE HIGHLIGHT HAVE VERIFIED WITH THE REMAINING AREA NOT THAT FAR AWAY. CLOUD COVER WILL NOT LET TEMPERATURES DROP MUCH MORE WITH THE EXCEPTION OF THE FAR WEST WHICH HAS BEEN CLEAR FOR ALMOST THE ENTIRE NIGHT. AM NOT OPTIMISTIC ABOUT MUCH MORE OF THE ADVISORY VERIFYING BUT ANY SMALL SHIFT OF THE WINDS AND TEMPERATURES IN THE RIGHT DIRECTION WILL CAUSE WIND CHILL ADVISORY CRITERIA TO BE REACHED. RIGHT REAR QUADRANT OF THE JET IS OVER THE AREA THIS MORNING. THEN A STRONGER LEFT FRONT QUADRANT STARTS AFFECTING THE AREA THIS AFTERNOON. THAT MOVES ACROSS THE AREA DURING THE FIRST HALF OF THE NIGHT. GOING BY 00Z SOUNDINGS AND FORECAST SOUNDINGS...LOW LEVEL AIR MASS IS SATURATED IN THE DENDRITIC ZONE. THAT COMBINED WITH THE JET LIFT IS CAUSING FLURRIES THIS MORNING. ALSO IN THE RETURN FLOW OVER THE WESTERN PORTION OF THE AREA PATCHY FOG HAS DEVELOPED WHICH WAS NOT CAUGHT BY ANYTHING EARLIER BUT NOW THE HRRR HAS RECENTLY CAUGHT ON TO THIS IDEA A LITTLE. SO WILL HAVE FLURRIES AND PATCHY FOG PER REALITY AND 00Z SOUNDINGS FOR THIS MORNING. AM THINKING THE AREA WILL BE CLOUDY TO MOSTLY CLOUDY MOST IF NOT THE ENTIRE DAY WITH MAYBE THE EXCEPTION IN THE FAR WEST. SO TENDED TO COOL MAXES FROM PREVIOUS FORECAST WITH THE EASTERN PORTION BEING THE COLDEST. TRICKY FORECAST FOR TONIGHT. SURFACE TROUGH STARTS MOVING THROUGH EARLY IN THE EVENING WITH WESTERLY WINDS AND CLEARING BEHIND IT. TEMPERATURES WILL NOT RISE MUCH DURING THE DAY SO OVERNIGHT TEMPERATURES WILL HAVE A GOOD START IN DROPPING AND GETTING COLDER. HOWEVER...PRETTY SIGNIFICANT WARM AIR ADVECTION BEHIND THE TROUGH. TENDED TO NOT CHANGE THE MINS VERY MUCH. NEXT THE PREVIOUS FORECAST HAD PATCHY FOG AND DRIZZLE IN ADVANCE OF THE SURFACE TROUGH. SOUNDINGS SHOW MOISTURE IS VERY SHALLOW AHEAD OF THE SURFACE TROUGH. CAN SEE FOG...ESPECIALLY AFTER WHAT HAS HAPPENED THIS MORNING...BUT THINK THE MOISTURE IS TOO SHALLOW FOR FREEZING DRIZZLE. SO REMOVED THAT AND KEPT THE FOG. SATURDAY/SATURDAY NIGHT...MODEL DIFFERENCES REALLY START SHOWING THEMSELVES HEAR. MODELS DIFFER ON THE POSITION AND STRUCTURE OF A COMPLICATED JET WHICH HAS DIFFERENT CONSEQUENCES IN THE FORECAST. AT THIS TIME THE BEST LIFT LOOKS LIKE IT DOES NOT ARRIVE UNTIL THE AFTERNOON IN THE FORM OF A STRONG JET AND PV ANOMALY. MODEL SOUNDINGS ARE SCARCE WITH MOISTURE IN THE LOW LEVELS EVEN IN THE AFTERNOON. CONSIDERING THE TIMING AND DEGREE OF LIFT...REMOVED PRECIPITATION FROM THE MORNING AND KEPT THE PREVIOUS FORECASTS POPS FOR THE AFTERNOON WHICH IS FLURRIES AND SLIGHT CHANCE POPS. THE ABOVE MENTIONED DYNAMICS MOVE THROUGH BY LATE AFTERNOON. ANOTHER SHORTWAVE TROUGH COMES THROUGH DURING THE NIGHT PLUS THE REAL STRONG ARCTIC FRONT MOVES IN THE LAST HALF OF THE NIGHT. SO ALSO KEPT THE NIGHT POPS WHEN CONSIDERING MODEL DIFFERENCES AND UNCERTAINTY BUT THINK POPS MAY BE OVERDONE. SOMETHING ELSE TO WATCH FOR THE NIGHT. CONSIDERING THE AMOUNT OF COLD AIR ADVECTION... PRESSURE GRADIENT...AND INDICATED 3 HOUR PRESSURE RISE...BREEZY AND MORE LIKELY WINDY CONDITIONS COULD DEVELOP. AND IF THAT IS NOT ENOUGH...THERE ARE HUGE DIFFERENCES IN THE TEMPERATURE FORECASTS FOR THE DAY. AS SPECIFIED ABOVE THE ARCTIC BOUNDARY MOVES INTO THE AREA DURING THE NIGHT. HOWEVER...MODELS ARE SHOWING ANOTHER WEAKER BOUNDARY/PRELIMINARY COLD PUSH MOVING INTO THE AREA...ESPECIALLY THE EASTERN AND CENTRAL PORTIONS...DURING THE LATE MORNING AND AFTERNOON HOURS. THE TEMPERATURE FORECAST CAN GO EITHER WAY BUT THE MODELS FOR THE MOST PART HAVE BEEN CONSISTENT IN BRINGING IN THIS COOLER AIR. CONSIDERING WHEN THE SHORTWAVE TROUGH PUSHING THIS FEATURE MOVES THROUGH...LIKE AN EARLIER ARRIVAL OF THE COLD AIR. MADE SLIGHT ADJUSTMENTS ON THE TEMPERATURES AND IN SOME CASES SPLIT THE DIFFERENCE BETWEEN THE EXTREMES. SUNDAY/SUNDAY NIGHT...MOST OF THE MODELS BLAST THE FRONT THROUGH EARLY IN THE DAY WITH A MODEL OR TWO RETREATING THE FRONT AND THEN BRING IT BACK THROUGH OR BRINGING THE FRONT THROUGH SLOWER. AS A RESULT THERE ARE EVEN BIGGER DIFFERENCES IN THE TEMPERATURES FOR THIS DAY. TENDED TO FOLLOW THE CONSENSUS AND WENT COLDER. PRECIPITATION FORECAST ALSO REMAINS UNCERTAIN. OUR AREA TENDS TO REMAIN BETWEEN TWO DIFFERENT JET SEGMENTS FOR MOST OF THE DAY WHEN BY LATE IN THE DAY A COUPLED JET STRUCTURE IS INDICATED. THEN THE BRUNT OF THIS AND OTHER LIFT MOVES THROUGH DURING THE NIGHT. THETA-E LAPSE RATES GET BETTER DURING THE NIGHT AS WELL. SOUNDINGS START MOISTENING UP IN THE AFTERNOON AND REALLY ONLY BECOME SATURATED DURING THE NIGHT. SO BELIEVE THAT THE BEST CHANCE FOR PRECIPITATION WILL BE LATE IN THE AFTERNOON AND ESPECIALLY DURING THE NIGHT ALTHOUGH NEIGHBORS HAVE THE HIGHEST POPS DURING THE DAY. SO MADE TWO ADJUSTMENTS PER REASONING ABOVE. SPLIT SUNDAY POPS INTO A MORNING AND AFTERNOON WITH HIGHER POPS IN THE AFTERNOON. RAISED POPS INTO THE LOW CHANCE CATEGORY FOR THE NIGHT. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 402 AM MST FRI FEB 7 2014 AN UPPER LEVEL SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA DURING THE MONDAY THROUGH TUESDAY TIMEFRAME. MODELS DISAGREE WHEN IT WILL HAPPEN...BUT HAVE BEEN TRENDING THE SHORT WAVE TO THE SOUTHWEST. RIGHT NOW THE WESTERN PART OF THE AREA LOOKS TO HAVE THE BEST SHOT AT RECEIVING SNOW AS THE SHORT WAVE TROUGH MOVES THROUGH. BEHIND THE TROUGH SOUTHERLY 850MB WINDS WILL SPREAD NORTH BRINGING WARMER AIR OVER THE AREA. EVEN IF THE MAJORITY OF THE LIFT IS FURTHER WEST...WITH A SATURATED ENVIRONMENT AND SURFACE TEMPERATURES IN THE DENDRITIC ZONE...AM THINKING FLURRIES ARE A STRONG POSSIBILITY. A SHORT WAVE RIDGE MOVES THROUGH FOLLOWED BY ANOTHER WEDNESDAY...HOWEVER THE TROUGH IS FAIRLY SHALLOW AND DEEPENS EAST OF THE AREA WHERE PRECIP. CHANCES WILL BE MORE LIKELY. OTHERWISE THE LAMINAR NORTHWEST FLOW WILL BE FAIRLY DRY AS THE UPPER LEVEL RIDGE TO THE WEST SLOWLY NUDGES EASTWARD. TEMPERATURES FOR THE PERIOD WILL START OUT AROUND 20 DEGREES BELOW NORMAL. BY WEDNESDAY NEAR NORMAL TEMPERATURES WILL RETURN AS THE COLDER AIR REMAINS OVER THE NORTHERN PLAINS WITH A SHORT WAVE TROUGH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 440 AM MST FRI FEB 7 2014 TRICKY SET OF TAFS ESPECIALLY CURRENT MODEL SUITE CATCHING THE LOW LEVEL MOISTURE/THERMAL FIELD VERY WELL. FOR KGLD...MVFR CEILINGS AND VISIBILITY WILL OCCUR THROUGH 18Z. THEN PRECIPITATION AND FOG ENDS WITH MVFR CEILINGS LASTING LATE AFTERNOON. AFTER THAT VFR CONDITIONS ARE EXPECTED. FOR KMCK...MVFR CEILINGS ARE EXPECTED UNTIL LATE AFTERNOON/EARLY EVENING. AFTER THAT A SHORT PERIOD OF IFR CEILINGS ARE EXPECTED UNTIL BECOME MVFR AROUND 06Z. BY 09Z VFR CONDITIONS ARE EXPECTED. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND CHILL ADVISORY UNTIL 10 AM MST /11 AM CST/ THIS MORNING FOR KSZ001>004-013>016-027>029. CO...WIND CHILL ADVISORY UNTIL 10 AM MST THIS MORNING FOR COZ090>092. NE...WIND CHILL ADVISORY UNTIL 10 AM MST /11 AM CST/ THIS MORNING FOR NEZ079>081. && $$ SHORT TERM...BULLER LONG TERM...JTL AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
511 AM CST Fri Feb 7 2014 ...AVIATION UPDATE... .SHORT TERM...(Today and Tonight) Issued at 300 AM CST FRI FEB 7 2014 09Z water vapor imagery shows a low amplitude shortwave coming across NM while a closed low spins off the British Columbia coast with another shortwave rotating around the low towards ID. Meanwhile surface obs show an expansive ridge of high pressure centered over the middle MS river valley. Surface winds have already started to show southerly flow returning to central KS. Cloud cover has prevented temps from falling below zero for most areas. This combined with calm winds means wind chill values are not quite as low as originally forecast. For today and tonight, the forecast area is expected to generally remain in between the main two shortwaves with the southern wave moving across OK and TX today while the wave near ID moves from the northern plains into IA overnight. So in general large scale forcing for precip appears to be pretty marginal. There remains some indications for some weak isentropic upglide through the day and into the evening within the low level warm air advection pattern on the back side of the departing surface ridge. However the isentropic upglide never really looks robust. Model forecast soundings continue to suggest the stratus layer will be around -12C through at least the day. So with the likelihood for ice within the cloud think trace amounts of light snow would be the most likely precip today. Overnight the cloud layer becomes relatively warmer so ice becomes less likely. However models show only very weak vertical motion if there is any at all. The 00Z NAM was the most robust with the low level vertical motion tonight, but was also considered an outlier on the strong side in amplifying the northern shortwave. The 06Z NAM has trended less amplified with the wave and also shows less vertical motion within the cloud overnight. So think chances for measurable precip are less than 20 percent and have lowered POPs. Am not that excited about freezing drizzle chances either, but will keep a mention across southern counties where mid levels are most likely to dry out leaving only super cooled water in the cloud. Tweaked highs today down a degree from the previous forecast due mainly to overcast skies expected through the day. Still with the weak warm air advection, highs should manage the middle teens. Do not think there will be much of a diurnal change between today`s highs and Saturday`s lows with southerly winds and overcast skies persisting through the night. Therefore the forecast has Lows Saturday morning in the 10 to 15 degree range. Wolters .LONG TERM...(Saturday through Thursday) Issued at 300 AM CST FRI FEB 7 2014 An upper trough on Saturday continues to deepen as it migrates southeastward towards the Mississippi Valley. A trailing surface low will force a cold front into northeast Kansas on Saturday afternoon. Could see some decent warming ahead of the wind shift with clearing skies and temperatures peaking into the upper 20s/lower 30s. Cold air advection quickly spreads behind the front, falling temperatures through the afternoon and evening. Models deviate somewhat on how far south the 1040 MB surface high spreads southward behind the departing trough. Overnight lows Sunday morning were averaged in the single digits to low teens, however if the ECMWF were to verify spreading the ridge axis further south, actual temperatures Sunday could be much lower. The arctic high pressure influence Saturday through Tuesday will keep temperatures below normal. Highs overall range in the teens and lower 20s with overnight lows in the single digits, close to zero degrees near the Nebraska and Kansas border. Wind chills at this time do not appear to be much lower as high pressure maintains light wind speeds. On Wednesday, upper shortwave trough entering the Pacific Northwest deepens across the Northern Plains. Meanwhile, the accompanying h85 trough backs winds to the southwest, advecting much needed warm air into northeast Kansas for Wednesday and especially Thursday. Wednesday highs range at and just above the freezing mark and Thursday is currently progged in the 40s allowing for ample melting of the snow to occur. Focus turns to precipitation chances where confidence in each event is low due to the very active and weak zonal flow in the mid levels. The aforementioned shortwave trough expected to bring a cold front through on Saturday, also develops a strong PV anomaly over eastern Nebraska into southern Iowa. While ample lift is prevalent just to our northeast, could still some light snow across far northeast Kansas. Therefore kept the previous forecast with little to no accumulations expected. The 500 HPA jet increases southward into the area with increasing isentropic lift in the 850-700 MB layer. Saturation is difficult to achieve dependent on the model, NAM remaining dry in the dendritic layer while the GFS saturates the column by early Sunday. Regardless, forcing on either model is not particularly strong to warrant several inches of accumulating snow. Snow ratios do appear more on the higher side between 15 and 20:1 translating to near an inch of new snowfall on Sunday. Pops were increased ten percent into the chance category for this period. Models differ greatly by Monday as the ECMWF is slower than the GFS by a day with the next shortwave trough coming off the California coast. The GFS also keeps the PV anomaly over the Southern Plains with some minor QPF values over the southern half of the CWA. Have therefore kept the slight chances for snow Monday through Tuesday with no expectations of snow accumulating at this point. Forecast becomes dry Wednesday onward. Another system following a similar track across the Intermountain West deepens over Nebraska on Wednesday evening. Confidence is too low for mentioning precipitation; trends of the models will be monitored for consistency in the coming days. && .AVIATION...(For the 12Z TAFs through 12Z Saturday Morning) Issued at 511 AM CST FRI FEB 7 2014 Models show stratus hanging in through Saturday morning as low level warm air advection brings relatively moist air into the area. Main uncertainty is when CIGS might lower to MVFR. RAP has tended to be aggressive with low level RH and the NAM seems to be the slowest in bringing the lower CIGS into the terminals. So used a compromise in timing with the RAP/NAM/GFS which was pretty close to the prev forecast. Low level vertical motion continues to look meager so any precip should be very light. Any VSBY restrictions should remain above 3SM due to expected light nature to any flurries or very light mist and some mixing in the boundary layer. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...Wolters LONG TERM...Bowen AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
402 AM MST FRI FEB 7 2014 .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 402 AM MST FRI FEB 7 2014 FORECAST CONCERNS WILL BE THE CHANCE OF PRECIPITATION INTO THE WEEKEND AND WHAT TO DO WITH THE TEMPERATURES...ESPECIALLY THE HIGH TEMPERATURES. SATELLITE SHOWING A VERY BLOCKY AND AMPLIFIED FLOW OVER THE PACIFIC TO ALONG THE WEST COAST OF NORTH AMERICA. THIS TRANSITIONS TO BROAD TROUGHINESS AND FAST WESTERLY FLOW OVER THE COUNTRY. SYSTEM OVER THE NORTH CENTRAL PORTION OF THE COUNTRY IS MOVING EAST. TWO STRONGER SOUTHERN STREAM SHORTWAVES ARE OVER THE DESERT SOUTHWEST AND EASTERN NEW MEXICO/WESTERN TEXAS. LOW LEVEL AIR MASS HAS MODIFIED SOME BUT IS STILL COLD AND MOIST. AT JET LEVEL...MODELS INITIALIZED FINE AT JET LEVEL. AT MID LEVELS... THE GFS...UKMET...CANADIAN AND ECMWF DID THE BEST. THE ECMWF WAS DOING BEST ON THE SURFACE WIND AND PRESSURE FIELD. THE ECMWF WAS DOING A LITTLE BETTER THAN THE GFS ON THE LOW LEVEL THERMAL FIELD. THIS WILL BE A LOW CONFIDENCE FORECAST FOR A COUPLE OF REASONS. FIRST THE MODELS...EVEN THE MESOSCALE ONES...HAVING A HARD TIME THIS MORNING RESOLVING LOW LEVEL MOISTURE AND TEMPERATURE AT THE BEGINNING OF THIS PERIOD. SECOND IS THE MODELS DIFFERENCE IN HANDLING UPPER JET FEATURES AND SURFACE/LOW LEVEL THERMAL FIELD THIS WEEKEND. TODAY/TONIGHT...IN REGARDS TO CURRENT WIND CHILL ADVISORY. THE WESTERN AND NORTHERN FRINGES OF THE HIGHLIGHT HAVE VERIFIED WITH THE REMAINING AREA NOT THAT FAR AWAY. CLOUD COVER WILL NOT LET TEMPERATURES DROP MUCH MORE WITH THE EXCEPTION OF THE FAR WEST WHICH HAS BEEN CLEAR FOR ALMOST THE ENTIRE NIGHT. AM NOT OPTIMISTIC ABOUT MUCH MORE OF THE ADVISORY VERIFYING BUT ANY SMALL SHIFT OF THE WINDS AND TEMPERATURES IN THE RIGHT DIRECTION WILL CAUSE WIND CHILL ADVISORY CRITERIA TO BE REACHED. RIGHT REAR QUADRANT OF THE JET IS OVER THE AREA THIS MORNING. THEN A STRONGER LEFT FRONT QUADRANT STARTS AFFECTING THE AREA THIS AFTERNOON. THAT MOVES ACROSS THE AREA DURING THE FIRST HALF OF THE NIGHT. GOING BY 00Z SOUNDINGS AND FORECAST SOUNDINGS...LOW LEVEL AIR MASS IS SATURATED IN THE DENDRITIC ZONE. THAT COMBINED WITH THE JET LIFT IS CAUSING FLURRIES THIS MORNING. ALSO IN THE RETURN FLOW OVER THE WESTERN PORTION OF THE AREA PATCHY FOG HAS DEVELOPED WHICH WAS NOT CAUGHT BY ANYTHING EARLIER BUT NOW THE HRRR HAS RECENTLY CAUGHT ON TO THIS IDEA A LITTLE. SO WILL HAVE FLURRIES AND PATCHY FOG PER REALITY AND 00Z SOUNDINGS FOR THIS MORNING. AM THINKING THE AREA WILL BE CLOUDY TO MOSTLY CLOUDY MOST IF NOT THE ENTIRE DAY WITH MAYBE THE EXCEPTION IN THE FAR WEST. SO TENDED TO COOL MAXES FROM PREVIOUS FORECAST WITH THE EASTERN PORTION BEING THE COLDEST. TRICKY FORECAST FOR TONIGHT. SURFACE TROUGH STARTS MOVING THROUGH EARLY IN THE EVENING WITH WESTERLY WINDS AND CLEARING BEHIND IT. TEMPERATURES WILL NOT RISE MUCH DURING THE DAY SO OVERNIGHT TEMPERATURES WILL HAVE A GOOD START IN DROPPING AND GETTING COLDER. HOWEVER...PRETTY SIGNIFICANT WARM AIR ADVECTION BEHIND THE TROUGH. TENDED TO NOT CHANGE THE MINS VERY MUCH. NEXT THE PREVIOUS FORECAST HAD PATCHY FOG AND DRIZZLE IN ADVANCE OF THE SURFACE TROUGH. SOUNDINGS SHOW MOISTURE IS VERY SHALLOW AHEAD OF THE SURFACE TROUGH. CAN SEE FOG...ESPECIALLY AFTER WHAT HAS HAPPENED THIS MORNING...BUT THINK THE MOISTURE IS TOO SHALLOW FOR FREEZING DRIZZLE. SO REMOVED THAT AND KEPT THE FOG. SATURDAY/SATURDAY NIGHT...MODEL DIFFERENCES REALLY START SHOWING THEMSELVES HEAR. MODELS DIFFER ON THE POSITION AND STRUCTURE OF A COMPLICATED JET WHICH HAS DIFFERENT CONSEQUENCES IN THE FORECAST. AT THIS TIME THE BEST LIFT LOOKS LIKE IT DOES NOT ARRIVE UNTIL THE AFTERNOON IN THE FORM OF A STRONG JET AND PV ANOMALY. MODEL SOUNDINGS ARE SCARCE WITH MOISTURE IN THE LOW LEVELS EVEN IN THE AFTERNOON. CONSIDERING THE TIMING AND DEGREE OF LIFT...REMOVED PRECIPITATION FROM THE MORNING AND KEPT THE PREVIOUS FORECASTS POPS FOR THE AFTERNOON WHICH IS FLURRIES AND SLIGHT CHANCE POPS. THE ABOVE MENTIONED DYNAMICS MOVE THROUGH BY LATE AFTERNOON. ANOTHER SHORTWAVE TROUGH COMES THROUGH DURING THE NIGHT PLUS THE REAL STRONG ARCTIC FRONT MOVES IN THE LAST HALF OF THE NIGHT. SO ALSO KEPT THE NIGHT POPS WHEN CONSIDERING MODEL DIFFERENCES AND UNCERTAINTY BUT THINK POPS MAY BE OVERDONE. SOMETHING ELSE TO WATCH FOR THE NIGHT. CONSIDERING THE AMOUNT OF COLD AIR ADVECTION... PRESSURE GRADIENT...AND INDICATED 3 HOUR PRESSURE RISE...BREEZY AND MORE LIKELY WINDY CONDITIONS COULD DEVELOP. AND IF THAT IS NOT ENOUGH...THERE ARE HUGE DIFFERENCES IN THE TEMPERATURE FORECASTS FOR THE DAY. AS SPECIFIED ABOVE THE ARCTIC BOUNDARY MOVES INTO THE AREA DURING THE NIGHT. HOWEVER...MODELS ARE SHOWING ANOTHER WEAKER BOUNDARY/PRELIMINARY COLD PUSH MOVING INTO THE AREA...ESPECIALLY THE EASTERN AND CENTRAL PORTIONS...DURING THE LATE MORNING AND AFTERNOON HOURS. THE TEMPERATURE FORECAST CAN GO EITHER WAY BUT THE MODELS FOR THE MOST PART HAVE BEEN CONSISTENT IN BRINGING IN THIS COOLER AIR. CONSIDERING WHEN THE SHORTWAVE TROUGH PUSHING THIS FEATURE MOVES THROUGH...LIKE AN EARLIER ARRIVAL OF THE COLD AIR. MADE SLIGHT ADJUSTMENTS ON THE TEMPERATURES AND IN SOME CASES SPLIT THE DIFFERENCE BETWEEN THE EXTREMES. SUNDAY/SUNDAY NIGHT...MOST OF THE MODELS BLAST THE FRONT THROUGH EARLY IN THE DAY WITH A MODEL OR TWO RETREATING THE FRONT AND THEN BRING IT BACK THROUGH OR BRINGING THE FRONT THROUGH SLOWER. AS A RESULT THERE ARE EVEN BIGGER DIFFERENCES IN THE TEMPERATURES FOR THIS DAY. TENDED TO FOLLOW THE CONSENSUS AND WENT COLDER. PRECIPITATION FORECAST ALSO REMAINS UNCERTAIN. OUR AREA TENDS TO REMAIN BETWEEN TWO DIFFERENT JET SEGMENTS FOR MOST OF THE DAY WHEN BY LATE IN THE DAY A COUPLED JET STRUCTURE IS INDICATED. THEN THE BRUNT OF THIS AND OTHER LIFT MOVES THROUGH DURING THE NIGHT. THETA-E LAPSE RATES GET BETTER DURING THE NIGHT AS WELL. SOUNDINGS START MOISTENING UP IN THE AFTERNOON AND REALLY ONLY BECOME SATURATED DURING THE NIGHT. SO BELIEVE THAT THE BEST CHANCE FOR PRECIPITATION WILL BE LATE IN THE AFTERNOON AND ESPECIALLY DURING THE NIGHT ALTHOUGH NEIGHBORS HAVE THE HIGHEST POPS DURING THE DAY. SO MADE TWO ADJUSTMENTS PER REASONING ABOVE. SPLIT SUNDAY POPS INTO A MORNING AND AFTERNOON WITH HIGHER POPS IN THE AFTERNOON. RAISED POPS INTO THE LOW CHANCE CATEGORY FOR THE NIGHT. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 402 AM MST FRI FEB 7 2014 AN UPPER LEVEL SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA DURING THE MONDAY THROUGH TUESDAY TIMEFRAME. MODELS DISAGREE WHEN IT WILL HAPPEN...BUT HAVE BEEN TRENDING THE SHORT WAVE TO THE SOUTHWEST. RIGHT NOW THE WESTERN PART OF THE AREA LOOKS TO HAVE THE BEST SHOT AT RECEIVING SNOW AS THE SHORT WAVE TROUGH MOVES THROUGH. BEHIND THE TROUGH SOUTHERLY 850MB WINDS WILL SPREAD NORTH BRINGING WARMER AIR OVER THE AREA. EVEN IF THE MAJORITY OF THE LIFT IS FURTHER WEST...WITH A SATURATED ENVIRONMENT AND SURFACE TEMPERATURES IN THE DENDRITIC ZONE...AM THINKING FLURRIES ARE A STRONG POSSIBILITY. A SHORT WAVE RIDGE MOVES THROUGH FOLLOWED BY ANOTHER WEDNESDAY...HOWEVER THE TROUGH IS FAIRLY SHALLOW AND DEEPENS EAST OF THE AREA WHERE PRECIP. CHANCES WILL BE MORE LIKELY. OTHERWISE THE LAMINAR NORTHWEST FLOW WILL BE FAIRLY DRY AS THE UPPER LEVEL RIDGE TO THE WEST SLOWLY NUDGES EASTWARD. TEMPERATURES FOR THE PERIOD WILL START OUT AROUND 20 DEGREES BELOW NORMAL. BY WEDNESDAY NEAR NORMAL TEMPERATURES WILL RETURN AS THE COLDER AIR REMAINS OVER THE NORTHERN PLAINS WITH A SHORT WAVE TROUGH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1049 PM MST THU FEB 6 2014 GLD MAY SEE A SLIGHT REDUCTION IN VISIBILITY BETWEEN 13-15Z... OTHERWISE EXPECT MVFR CONDITIONS TO PREVAIL THROUGH THE MAJORITY OF THE TAF PERIOD AT BOTH MCK AND GLD DUE MAINLY TO LOW CLOUDS. AFTER 00-03Z...EXPECT LOW CLOUDS TO BEGIN DISSIPATING WITH AN INCREASE IN MID LEVEL CLOUDS ACROSS THE REGION. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND CHILL ADVISORY UNTIL 10 AM MST /11 AM CST/ FRIDAY FOR KSZ001>004-013>016-027>029. CO...WIND CHILL ADVISORY UNTIL 10 AM MST FRIDAY FOR COZ090>092. NE...WIND CHILL ADVISORY UNTIL 10 AM MST /11 AM CST/ FRIDAY FOR NEZ079>081. && $$ SHORT TERM...BULLER LONG TERM...JTL AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
838 PM CST SAT FEB 8 2014 .UPDATE...TEMPERATURES DROPPING QUICKER OVER INTERIOR SOUTHEAST TEXAS AND PORTIONS OF CENTRAL LOUISIANA SO WENT AHEAD AND ADJUSTED MIN TEMPS DOWN CLOSER TO RUC VALUES. GRIDS UPDATED. ZONES TO FOLLOW SWEENEY && .PREV DISCUSSION... /ISSUED 734 PM CST SAT FEB 8 2014/ UPDATE...THE EVENING LCH SOUNDING SHOWS THE INVERSION REMAINS SOLID BELOW 3100 FT WHILE SUBSIDENCE HAS PRODUCED A DRY ATMOSPHERE ABOVE THIS LAYER. THE PREVIOUS AIRMASS HAD AN ADDITIONAL LAYER OF MOISTURE UP TO 5K FT. WHAT HAD BEEN A LIGHT OFFSHORE FLOW HAS COME ABOUT TO AN ONSHORE FLOW WITH MOISTURE MAKING ENROADS NEAR THE SURFACE. THE LATEST MAV IS SHOWING A STRONG FOG SIGNAL AND VIS IS ALREADY BEGINNING TO LOWER AT BPT AND POINTS WEST. WILL GO WITH WIDESPREAD FOG FORMATION BEFORE MIDNIGHT AND LINGERING UNTIL MID- MORNING SUNDAY. WE MAY NEED TO GO WITH A DENSE FOG ADVISORY EXCEPT THAT LOW CIGS MAY DELAY OR IMPEDE THE FORMATION OF DENSE FOG. ADJUSTED TEMPS HIGHER NORTH OF THE I-10 CORRIDOR DUE TO THE APPROACHING SATURATION. SWEENEY PREV DISCUSSION... /ISSUED 525 PM CST SAT FEB 8 2014/ AVIATION... CLOUD SHIELD FALLING APART BUT WILL REDEVELOP LATER THIS EVE WITH CEILINGS DROPPING TO MVFR/IFR TOWARDS MIDNIGHT. PREV DISCUSSION... /ISSUED 205 PM CST SAT FEB 8 2014/ DISCUSSION... CURRENT ANALYSIS SHOWS WEAK HIGH PRESSURE RIDGING ACROSS THE MS VALLEY...WITH WEAK RETURN FLOW BEGINNING TO SET UP ACROSS SE TX/SW LA THIS AFTERNOON. MOSTLY BKN/OVC ~2500FT OBSERVED FOR MOST OF THE DAY...WITH A FEW AREAS OF SHORT LIVED CLEARING ACROSS C AND SC LA. OTHERWISE...TEMPS HAVE RISEN INTO THE LOWER/MID 50S THIS AFTERNOON. CLEARING NOT LOOKING AS PROMISING AS BEFORE...AS MOISTURE CONTINUES TO BE TRAPPED UNDERNEATH THE INVERSION LAYER. WHILE EXPECTING SOME MIXING...WILL KEEP PARTLY TO MOSTLY CLOUDY THIS EVENING...BECOMING PREDOMINATELY MOSTLY CLOUDY AFTER MIDNIGHT...AND REMAINING INTO SUN. EXPECT LOWS MAINLY IN THE 40S SUN MORNING. WITH CONTINUED WAA...HIGHS SUN EXPECTED TO RISE INTO THE LOWER/MID 60S. ALONG WITH THE WAA...HIGHER DEWPTS IN THE 50S AND EVENTUALLY 60S WILL ADVECT OVER THE COOLER WATERS OFF THE SE TX/LA COAST AND LAKES/BAYS (RUNNING FROM THE MID 40S TO LOWER 50S). THUS...PATCHY MARINE FOG IS EXPECTED AFTER SUNSET SUN...LIKELY BECOMING MORE WIDESPREAD AFTER MID THRU NOON MON. THE NEXT SERIES OF UPPER LEVEL SYSTEMS AND COLD FRONT EXPECTED TO AFFECT THE REGION MON-WED. THE FRONT IS EXPECTED TO MOVE THRU MON AFTERNOON AND EVENING...STALLING ACROSS THE NW GULF TUE AS THE UPPER LEVEL FLOW REMAINS FROM THE W. THIS HAS BEEN CONSISTENT IN GENERATING ONE OR TWO FRONTAL WAVES/SFC LOWS TO MOVE NE DURING THE DAY TUE/EARLY WED. MODEL AGREEMENT HAS BECOME MORE DIVERGENT TODAY...WITH THE 12Z GFS NOW LINGERING THE PRECIP WELL INTO WED MORNING...WITH THE LATEST 12Z ECMWF NOW A BIT QUICKER AND ENDING THE PRECIP LATE TUE EVENING. BOTH SHOWING SFC TEMPS IN THE MID/UPPER 30S FOR TUE MORNING...BUT SLIGHTLY COLDER FOR WED MORNING (WITH THE ECMWF COLDER WITH MORE CAA AS THE SYSTEM EXITS THE REGION). TO SUMMARIZE THIS...UNTIL MORE CONFIDENCE IS SEEN...OPTED TO KEEP INHERITED TEMPS JUST ABOVE FREEZING WED MORNING ACROSS INLAND SE TX/C LA...WITH THE GOOD CHANCE OF RAIN ENDING WED MORNING. OF COURSE...ANY SLIGHT MODIFICATION OF TEMPS DOWNWARD WOULD DICTATE THE POSSIBILITY OF FROZEN PRECIP FOR THIS REGION...BUT AGAIN...JUST NOT ENOUGH CONFIDENCE AT THIS TIME. REMAINDER OF FORECAST FOR NEXT WEEK LOOKS PRECIP FREE AS ANOTHER WEAKER FRONT EXPECTED TO RE-INFORCE THE DRY CONDITIONS ON THU. DML MARINE... A SOUTHERLY FLOW WILL RETURN TONIGHT IN ADVANCE OF THE NEXT COLD FRONT. THE FRONT IS EXPECTED TO STALL JUST OFFSHORE ON MONDAY...THEN REMAIN NEARLY STATIONARY JUST SOUTH OF THE COASTAL WATERS AS ONE OR MORE FRONTAL WAVES DEVELOP AND LIFT NORTHEAST ALONG THE BOUNDARY. MODERATE OFFSHORE FLOW AND ELEVATED RAIN CHANCES ARE EXPECTED MONDAY NIGHT THROUGH WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... KLCH 46 68 54 61 40 / 0 10 20 40 50 KBPT 46 71 54 60 40 / 0 10 20 40 50 KAEX 42 66 50 54 35 / 0 10 20 40 60 KLFT 46 69 54 62 40 / 0 10 10 40 50 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
941 PM EST SAT FEB 8 2014 .SYNOPSIS... HIGH PRESSURE WILL CROSS THE REGION TONIGHT THROUGH SUNDAY. LOW PRESSURE WILL TRACK SOUTHEAST OF THE REGION SUNDAY NIGHT THROUGH MONDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION THROUGH MID WEEK.&& .NEAR TERM /THROUGH SUNDAY NIGHT/... 941 PM UPDATE...HIGH PRESSURE CONTINUES TO BUILD TOWARD THE CWA OVERNIGHT. THERE ARE A FEW AREAS OF CLOUD COVER IMPACTING THE AREA. THE FIRST IS A BKN DECK AROUND 5K FT AGL ACROSS FAR NORTHERN MAINE THAT IS MOVING OFF THE ST LAWRENCE. THE SECOND IS A MORE CONCENTRATED AREA OF CLOUDS OFF OF LAKE ONTARIO AT AROUND 4K FT AGL THAT COVER THE AREA ALONG THE NY/VT BORDER WITH QUEBEC AND EXTEND INTO MAINE. THESE CLOUDS HAVE BEEN DISSIPATING ACROSS PISCATAQUIS COUNTY OVER THE PAST 1 TO 2 HOURS. THE THIRD AREA OF CLOUDS ARE CIRRUS MOVING ACROSS DOWNEAST AND INTO CENTRAL MAINE. THE MAIN IMPACT FROM THESE CLOUDS WILL BE ON TEMPERATURES OVERNIGHT. AS OF 9 PM THE COLDEST SPOTS ARE A LITTLE BELOW ZERO ACROSS THE VALLEYS OF NW AROOSTOOK COUNTY. DID MAKE A FEW TWEAKS TO THE LOWS...MAINLY ACROSS INTERIOR DOWNEAST WHERE A FEW SPOTS WERE ALREADY VERY CLOSE TO FORECAST LOWS. OTHERWISE ONLY A FEW MINOR ADJUSTMENTS TO THE SKY GRIDS. PREVIOUS DISCUSSION... BKN SC AND SCT FLURRIES ACROSS THE N SHOULD DISSIPATE BY LATE EVE AS WINDS DECREASE. WITH THE SFC HI APCHG LATER TNGT AND THEN CRESTING OVR THE FA BY SUN MORN...THE POTENTIAL EXISTS FOR DECOUPLING OF WINDS OVR SPCLY NRN/CNTRL VLY LCTNS BY LATE TNGT AND RADIATIONAL COOLING. WITH THIS IN MIND...WE WENT SIG BLO MOS GUIDANCE FOR OVRNGT LOWS OVR NRN VLYS AND SOMEWHAT BLO ELSEWHERE. MODELS INDICATE CLDNSS TO ADVANCE INTO SW PTNS OF THE FA LATE TNGT INTO SUN MORN AS A WEAK SUB-SYNOPTIC S/WV FROM THE LOWER GREAT LKS MOVES E INTO THE GULF OF ME. IT APPEARS MOST OF THE SIG LIFT WITH THIS SYSTEM SHOULD REMAIN S OF THE FA...SO WE DID NOT GO WITH ANY POPS ABV 14 PERCENT ATTM...BUT THIS WILL NEED TO BE MONITORED OVRNGT. MOST OF THE CLDNSS OVR SRN PTNS OF THE FA SHOULD THEN EXIT BY ERLY SUN AFTN...BEFORE CLDS INCREASE AGAIN FOR WRN AND SRN PTNS OF THE FA BY SUN EVE AHEAD OF A MORE SYNOPTIC SCALE S/WV FROM THE LOWER GREAT LKS. IT APPEARS...THAT ANY LGT SN WITH THIS SYSTEM FOR OUR FA WILL HOLD OFF UNTIL SUN NGT. OTHERWISE...AFT CHILLY MORN LOWS...SPCLY ACROSS THE N...TEMPS SHOULD THEN RECOVER TO SIMILAR HI TEMPS SUN AS THIS AFTN. && .SHORT TERM /MONDAY THROUGH TUESDAY/... LOW PRESSURE WILL TRACK SOUTHEAST OF THE GULF OF MAINE SUNDAY NIGHT INTO MONDAY. THE LOW WILL BRING LIGHT SNOW TO THE REGION SUNDAY NIGHT INTO EARLY MONDAY...TAPERING TO SNOW SHOWERS MONDAY AFTERNOON. THE STEADIEST SNOWS SUNDAY NIGHT INTO EARLY MONDAY WILL OCCUR ACROSS DOWNEAST PORTIONS OF THE THE FORECAST AREA WHERE 1 TO 3 INCHES OF TOTAL ACCUMULATION IS EXPECTED. LESSER SNOWS WILL OCCUR NORTHWARD ACROSS THE REMAINDER OF THE FORECAST AREA. HIGH PRESSURE WILL THEN BUILD EAST TOWARD THE REGION MONDAY NIGHT THROUGH TUESDAY. CLOUD COVER WILL DECREASE ACROSS THE REGION MONDAY NIGHT. PARTLY SUNNY SKIES ARE EXPECTED ACROSS NORTHERN AREAS TUESDAY WITH MOSTLY SUNNY SKIES DOWNEAST. TEMPERATURES WILL BE AT BELOW NORMAL LEVELS MONDAY/TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AT THE START OF THE PERIOD THE MODELS ARE IN GOOD AGREEMENT. A HIGH PRESSURE RIDGE WILL DOMINATE THE WEATHER ACROSS THE REGION AT THE START OF THE PERIOD. THE EXTENDED MODELS DIFFER A BIT ON PLACEMENT OF THE NEXT SYSTEMS THE FIRST LOW IS EITHER IN THE ERN GULF OF MEXICO OR ALONG THE ATLANTIC COAST OF GEORGIA. THE SECOND LOW MOVING EAST ACROSS SRN CANADA. THE SRN LOW WILL SLOWLY MOVE UP THE EAST COAST. THE ECMWF MOVES THE LOW INTO THE SRN GULF OF MAINE THUR AFTERNOON. THE GFS AND GEM THOUGH THEY DO NOT SHOW A CLOSED LOW...INDICATE THAT SOMETHING WILL BE IN THE SAME AREA AS THE ECMWF. AT THIS TIME THE RIDGE WILL HAVE BUILD EAST OF THE AREA...THE LOW AND ITS ASSOCIATED TROUGH MOVING EAST ACROSS SRN CANADA WILL BE EXTENDED NE TO SW ACROSS QUEBEC...THROUGH THE CENTRAL GREAT LAKES INTO NRN IL. THUR EVNG...THE ECMWF LOW MOVES NE INTO SW NOVA SCOTIA...THE GFS AND GEM CONTINUE TO INDICATE SOMETHING IN THE SAME AREA...THE TROUGH MOVES SE AND THE LOW OVER NOVA SCOTIA AND THE TROUGH BEGIN TO INTERACT ACROSS MAINE AND NEW BRUNSWICK. FRI MRNG THE GFS...ECMWF...AND GEM DIFFER ON THEIR RESPECTIVE SOLUTIONS. THE GFS MOVES THE TROUGH SOUTH TO THE GULF OF MAINE...WRAPS THE ENERGY FROM THE CURRENT LOW INTO A NEW ONE OVER BAR HARBOR...THE ECMWF ALSO SHOWS A MUCH WEAKER LOW OVR NRN PA...AS WELL AS MAINTAINING THE ORIGINAL LOW NOW WELL EAST OF THE AREA ENTERING THE WRN CANADIAN MARITIMES. THE GEM MAINTAINS THE ORIGINAL LOW MOVES IT INTO THE MARITIMES...ALSO MAINTAINS THE TROUGH ACROSS NRN MAINE...BACK ACROSS THE NRN GREAT LAKES TO A NEW LOW OVER LAKE HURON. BY SAT MRNG THE LOW MOVES EAST INTO THE MARITIMES...A WEAK HIGH PRESSURE RIDGE BUILDS ACROSS THE REGION...A LOW PRESSURE OVER THE CENTRAL GREAT LAKES WITH A COLD FRONT EXTENDING SOUTH THROUGH LA...INTO THE GULF OF MEXICO. SAT EVEN THE LOW MOVES EAST INTO CENTRAL QUEBEC...THE FRONT INTO WRN MAINE...AND BY THE END OF THE PERIOD...THE LOW MOVES INTO ERN QUEBEC...THE FRONT MOVES EAST INTO WRN NEW BRUNSWICK. LOADED THE SUPERBLEND FOR GRIDS. OVRNGT WED THRU THURS LOADED TWO SUPERBLEND AND 1 ECMWF FOR POPS..THIS WILL GIVE A BIT MORE WEIGHT TO THE GFS SOLUTION THROUGH THAT TIME FRAME WITHOUT A COMPLETE CHANGE FROM THE SUPERBLEND SOLUTION. NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. ADDED 20 TO WINDS FOR GUSTS OVER LAND 30 PERCENT OVER THE WATERS. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... NEAR TERM: MSLY VFR XPCTD THROUGH SUNDAY. THE HRRR HAS AT TIMES BEEN TRYING TO DEVELOP LOW STRATUS ALONG AND NEAR THE AROOSTOOK RIVER TOWARD MORNING...BUT CONFIDENCE IS VERY LOW AND WILL MAINTAIN A VFR FCST ATTM AT THE TERMINALS AND CONTINUE TO CLOSELY MONITOR. SHORT TERM: OCCASIONAL MVFR CONDITIONS ARE EXPECTED ACROSS NORTHERN PORTIONS OF THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY...WITH MVFR TO LIFR CONDITIONS ACROSS CENTRAL AND DOWNEAST AREAS. CONDITIONS WILL BEGIN TO IMPROVE ACROSS THE FORECAST AREA MONDAY AFTERNOON...THOUGH OCCASIONAL MVFR CONDITIONS WILL REMAIN POSSIBLE. OCCASIONAL MVFR CONDITIONS COULD LINGER ACROSS NORTHERN AREAS EARLY MONDAY NIGHT. OTHERWISE...VFR CONDITIONS ARE EXPECTED ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY. CONDITIONS WILL LOWER TO MVFR/IFR LEVELS LATER THURSDAY. && .MARINE... NEAR TERM: NO HDLNS XPCTD FOR THE NEAR TERM. THE COMBO OF WNW OF 10 TO 15 KT...SFC TEMPS IN THE LOW 20S AND SSTA`S IN THE UPPER 30S TO LOWER 40S RESULTED IN LGT FZSPY OVR OUR WATERS TNGT INTO ERLY SUN MORN...AFTERWHICH WINDS DROP ENOUGH FOR FZSPY TO NO LONGER BE AN ISSUE LATE SUN MORN ONWARD. WENT WITH A BLEND OF OPNL/MOS MODEL GUIDANCE FOR WINDS...AND WENT ABOUT A HLF FOOT HIGHER THAN WW3 WV GUIDANCE. SHORT TERM: CONDITIONS ARE GENERALLY EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY NIGHT THROUGH MONDAY NIGHT...THOUGH WIND GUSTS COULD APPROACH SMALL CRAFT ADVISORY LEVELS MONDAY AFTERNOON INTO EARLY MONDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS ARE THEN POSSIBLE TUESDAY. VISIBILITIES WILL BE REDUCED IN SNOW SUNDAY NIGHT INTO MONDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...CB/VJN SHORT TERM...NORCROSS LONG TERM...NORTON AVIATION...CB/VJN/NORCROSS MARINE...CB/VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1024 PM EST SAT FEB 8 2014 .SYNOPSIS... A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL KEEP A COLD...WESTERLY FLOW OF AIR OVER THE REGION INTO THE WEEKEND. A WEAK UPPER LEVEL AREA OF LOW PRESSURE WILL BRING SOME LIGHT SNOW TO THE AREA SUNDAY AFTERNOON AND NIGHT. LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO EARLY NEXT WEEK WITH ONLY MINOR ACCUMULATIONS. && .NEAR TERM /THROUGH SUNDAY/... 1015 PM UPDATE...BINOVC HAVE ALLOWED TEMPS TO DROP WELL INTO THE SINGLE NUMBERS ACROSS PARTS OF THE SOUTHERN TIER AND FINGER LAKES REGION. H5 SHORT WAVE CURRENTLY OVER LK ERIE WILL MOVE INTO WRN NY SHORTLY BRINGING SCATTERED FLURRIES AND A FEW SNOW SHOWERS TO CNTRL/NRN PTN OF FA OVERNIGHT. AS THIS OCCURS TEMPS WILL REBOUND SLIGHTLY OVER THE ABOVE MENTIONED AREA. FORECAST IN GOOD SHAPE JUST MINOR ADJ. 640 PM UPDATE...LOCAL RADARS SHOW WEAK RETURNS ACROSS CENTRAL NY AND NRN PA BUT SFC OBS INDICATE JUST MID LEVEL CLOUDS AND A PASSING FLURRY AT WILLIAMSPORT PA AND WELLSVILLE NY. RECENT RADAR TRENDS SHOW THE ACTIVITY WEAKENING FURTHER. UNTIL THE SHORT WAVE OVER SRN MI APPROACHES THE AREA LATE TONIGHT SCATTERED FLURRIES WILL BE THE MOST SIGNIFICANT WX EXPECTED. CURRENT FORECAST IN GOOD SHAPE JUST MINOR ADJ TO POPS/TEMPS. 230 PM UPDATE... 1029 MB SFC HIPRES LOCATED ACRS OH VLY WITH VRY WEAK SFC LOW DOWN ACRS WRN NC WITH INVERTED TROF AXIS EXTENDING UP NR THE MASON-DIXON LINE BRINGING LIGHT SNOW TO VA AND WV. MODELS SUGGESTING THIS CONVERGENCE LINE NOSES NORTH THIS EVNG POSSIBLY BRINGING LGT FLURRIES TO SW AREAS EARLY ON. MAIN FCST CONCERN WL BE WV APPCHG FM IOWA TONIGHT AND WHAT AFFECT, IF ANY, THIS WL HV ON FA. IF S/WV MAINTAINS CURRENT SPEED, EXPECT LIGHT SNOW TO MV INTO WRN SXNS OF CWA BFR MIDNIGHT TONIGHT. CERTAINLY NOT IMPRESSED WITH LIFT ASSOC WITH THIS SYSTEM FOR TONIGHT. ISENTROPIC UPGLIDE ON 270K LYR PER 12Z NAM FOR SYSTEM CURRENTLY OVR ERN IOWA IS SHOWING SOME LIFT IN MOISTURE AREA WHERE SNOW IS CURRENTLY FALLING AND FOLLOWING THIS AREA EASTWARD TWD NY STATE OVERNIGHT IT TRANSITIONS TO MORE OF NEUTRAL LIFT AND/OR DOWNGLIDE AS WV HEADS INTO WRN NY AT 06Z. THUS, DO THINK THAT THERE IS STILL A CHANCE FOR LIGHT SNOW SHOWERS ACRS WRN ZONES TONIGHT WITH JUST FLURRIES ELSEWHERE. IN THESE AREAS, EXPECT JUST UNDER 1/2 INCH ACCUMS. WITH EXTENSIVE CLD CVR EXPECTED TONIGHT, ONLY EXPECT MIN TEMPS TO DROP DOWN TWD 10F BY MRNG. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... 230 PM UPDATE... ANOTHER WV WL ZIP THRU THE UPR MIDWEST TOMORROW MRNG SPREADING LGT SNOW INTO THE CWA BY AFTN. THIS WV IS CURRENTLY COMING ONSHORE IN THE PACIFIC NORTHWEST. AS IT HEADS EAST, POPS WL INCREASE AFTER 16Z WITH CATEGORICAL EXPECTED DRG THE AFTN HRS. EXPECT ARND 1 INCH OF SNOW TOMORROW AFTN, MAINLY WEST OF I-81 CORRIDOR PROCEEDING EAST FM THERE. WV WL CONTINUE TO SHIFT ACRS CWA TOMORROW NGT WITH SNOW EXITING MOST OF CWA BY 06Z. NW FLOW KICKS IN BHND WITH H8 TEMPS APPCHG -18C AND INVERSION HGTS INCRS TO NR 750MB EXPECT GOOD BAND OF LK EFFECT SNOW TO GET GOING BTWN 06Z AND 12Z MONDAY ON 290 FLOW. MAX OMEGA IS PROGGED TO BE IN DENDRITE ZONE WITH BTWN 1-2 INCHES POSSIBLE THRU THIS TIME. LK EFFECT SNOW SHOWERS WL CONTINUE THRU THE DAY MON WITH FLOW BTWN 280-290 DRG THE DAY, KEYING IN ON SYRACUSE AREA AND POINTS TO THE SOUTHEAST. EXPECT MOST OF THE SNOW TO FALL BTWN 12Z AND 18Z THEN BCMG SCATTERED DUE TO DIURNAL HTG AFT THIS TIME. LK EFFECT WL CONTINUE THRU 18Z TUE BFR HIPRES BUILDS INTO THE AREA, SHIFTING FLOW ARND TO THE NORTH AND BRINGING IN SHORT FETCH ACRS LK ONTARIO, RESULTING IN DIMINISHING SNOW SHOWERS ON TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 300 PM EST UPDATE... TUESDAY NIGHT HIGH PRESSURE WILL DOMINATE THE NORTHEAST WITH WEAK ANTICYCLONIC FLOW ALOFT. THIS WILL RESULT IN QUIET WEATHER ACROSS THE CWA. TEMPS WEDNESDAY MORNING WILL BE QUITE CHILLY AGAIN WITH LOWS REACHING AS FAR AS NEGATIVE TEN BELOW. WINDS WILL BE QUITE LIGHT SO DO NOT EXPECT ANY WIND CHILL ADVISORIES ISSUED ATTM. THERE IS A LOT OF UNCERTAINTY IN THE EXTENDED FORECAST. DECIDED TO GO CLOSELY WITH WPC GUIDANCE AS THE GFS AND THE ECMWF INDICATE VERY DIFFERENT OUTCOMES IN THE EXTENDED. BUT THE MAIN PICTURE OF THE EXTENDED IS THAT ANOTHER UPPR LVL SHORTWAVE WILL MOVE EAST ACROSS CENTRAL CANADA LATE TUES/WEDNESDAY AND START TO PUSH THE SFC RIDGE EAST AND WILL EVENTUALLY MOVE OFF THE EAST COAST BY WEDNESDAY NIGHT. THE ECMWF INDICATES THE RIDGE WILL WEAKEN AND A SFC LOW WILL MOVE NORTH AND EAST ALONG THE CAST WED NIGHT BRINGING A CHANCE FOR SNOW SHOWERS WEDNESDAY NIGHT/THURS MORNING. IF THIS OCCURS THE SHOWERS WILL IMPACT THE SE PORTIONS OF THE CWA. THE GFS SHOWS THE RIDGE WILL MAINTAIN INTENSITY WHICH WILL PREVENT THE SFC LOW FROM IMPACTING THE CWA. THE FURTHER INTO THE FORECAST THE MORE MESSY THE FORECAST BECOMES. THE GFS BRINGS A SYSTEM THROUGH OUR CWA THURS NIGHT INTO FRI BRINGING A CHANCE FOR SNOW... HOWEVER THE ECMWF BRINGS IT THROUGH A DAY LATER AND POSSIBLY RAIN/SNOW MIX. THERE WILL BE A SYSTEM THIS COMING WEEKEND... BUT CONFIDENCE IS LOW ON IMPACTS OR TIMING SO JUST KEPT CHANCE IN THE FORECAST ATTM. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... A FAST MOVING WAVE WILL MOVE ACROSS THE TERMINALS LATE THIS EVENING AND EARLY SUNDAY MORNING. A VERY DRY AIRMASS IS CURRENTLY IN PLACE, SO IT IS HARD TO IMAGINE MUCH COVERAGE IN SNOW SHOWERS. THIS LOGIC IS SUPPORTED BY THE LATEST HRRR REF PROGS, WHICH SHOWS VERY WEAK RETURNS IN WIDELY SCATTERED ACTIVITY. A BETTER LOOKING WAVE REACHES THE REGION TOMORROW AFTERNOON. LIGHT SNOW SHOWERS WILL BECOME WIDESPREAD BY MID AFTERNOON, WITH MVFR RESTRICTIONS LIKELY TO PREVAIL. TEMPO IFR VISIBILITY IS CERTAINLY POSSIBLE. A BETTER CHANCE FOR IFR WILL BE BETWEEN 18Z AND 24Z AS COVERAGE MAXIMIZES UNDER BETTER UL SUPPORT. OUTLOOK... SUN AND SUNDAY NIGHT...VFR EARLY SUNDAY DECREASING TO MVFR SUNDAY AFTERNOON AND SUNDAY NIGHT IN OCCASIONAL LGT SNOW. MON/TUE...MVFR TO IFR POSSIBLE FOR THE CNY TERMINALS...IN LAKE- EFFECT SNOW SHWRS. VFR KAVP. WED/THURS...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PVN NEAR TERM...PVN/RRM SHORT TERM...PVN LONG TERM...KAH AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
644 PM EST SAT FEB 8 2014 .SYNOPSIS... A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL KEEP A COLD...WESTERLY FLOW OF AIR OVER THE REGION INTO THE WEEKEND. A WEAK UPPER LEVEL AREA OF LOW PRESSURE WILL BRING SOME LIGHT SNOW TO THE AREA SUNDAY AFTERNOON AND NIGHT. LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO EARLY NEXT WEEK WITH ONLY MINOR ACCUMULATIONS. && .NEAR TERM /THROUGH SUNDAY/... 640 PM UPDATE...LOCAL RADARS SHOW WEAK RETURNS ACROSS CENTRAL NY AND NRN PA BUT SFC OBS INDICATE JUST MID LEVEL CLOUDS AND A PASSING FLURRY AT WILLIAMSPORT PA AND WELLSVILLE NY. RECENT RADAR TRENDS SHOW THE ACTIVITY WEAKENING FURTHER. UNTIL THE SHORT WAVE OVER SRN MI APPROACHES THE AREA LATE TONIGHT SCATTERED FLURRIES WILL BE THE MOST SIGNIFICANT WX EXPECTED. CURRENT FORECAST IN GOOD SHAPE JUST MINOR ADJ TO POPS/TEMPS. 230 PM UPDATE... 1029 MB SFC HIPRES LOCATED ACRS OH VLY WITH VRY WEAK SFC LOW DOWN ACRS WRN NC WITH INVERTED TROF AXIS EXTENDING UP NR THE MASON-DIXON LINE BRINGING LIGHT SNOW TO VA AND WV. MODELS SUGGESTING THIS CONVERGENCE LINE NOSES NORTH THIS EVNG POSSIBLY BRINGING LGT FLURRIES TO SW AREAS EARLY ON. MAIN FCST CONCERN WL BE WV APPCHG FM IOWA TONIGHT AND WHAT AFFECT, IF ANY, THIS WL HV ON FA. IF S/WV MAINTAINS CURRENT SPEED, EXPECT LIGHT SNOW TO MV INTO WRN SXNS OF CWA BFR MIDNIGHT TONIGHT. CERTAINLY NOT IMPRESSED WITH LIFT ASSOC WITH THIS SYSTEM FOR TONIGHT. ISENTROPIC UPGLIDE ON 270K LYR PER 12Z NAM FOR SYSTEM CURRENTLY OVR ERN IOWA IS SHOWING SOME LIFT IN MOISTURE AREA WHERE SNOW IS CURRENTLY FALLING AND FOLLOWING THIS AREA EASTWARD TWD NY STATE OVERNIGHT IT TRANSITIONS TO MORE OF NEUTRAL LIFT AND/OR DOWNGLIDE AS WV HEADS INTO WRN NY AT 06Z. THUS, DO THINK THAT THERE IS STILL A CHANCE FOR LIGHT SNOW SHOWERS ACRS WRN ZONES TONIGHT WITH JUST FLURRIES ELSEWHERE. IN THESE AREAS, EXPECT JUST UNDER 1/2 INCH ACCUMS. WITH EXTENSIVE CLD CVR EXPECTED TONIGHT, ONLY EXPECT MIN TEMPS TO DROP DOWN TWD 10F BY MRNG. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... 230 PM UPDATE... ANOTHER WV WL ZIP THRU THE UPR MIDWEST TOMORROW MRNG SPREADING LGT SNOW INTO THE CWA BY AFTN. THIS WV IS CURRENTLY COMING ONSHORE IN THE PACIFIC NORTHWEST. AS IT HEADS EAST, POPS WL INCREASE AFTER 16Z WITH CATEGORICAL EXPECTED DRG THE AFTN HRS. EXPECT ARND 1 INCH OF SNOW TOMORROW AFTN, MAINLY WEST OF I-81 CORRIDOR PROCEEDING EAST FM THERE. WV WL CONTINUE TO SHIFT ACRS CWA TOMORROW NGT WITH SNOW EXITING MOST OF CWA BY 06Z. NW FLOW KICKS IN BHND WITH H8 TEMPS APPCHG -18C AND INVERSION HGTS INCRS TO NR 750MB EXPECT GOOD BAND OF LK EFFECT SNOW TO GET GOING BTWN 06Z AND 12Z MONDAY ON 290 FLOW. MAX OMEGA IS PROGGED TO BE IN DENDRITE ZONE WITH BTWN 1-2 INCHES POSSIBLE THRU THIS TIME. LK EFFECT SNOW SHOWERS WL CONTINUE THRU THE DAY MON WITH FLOW BTWN 280-290 DRG THE DAY, KEYING IN ON SYRACUSE AREA AND POINTS TO THE SOUTHEAST. EXPECT MOST OF THE SNOW TO FALL BTWN 12Z AND 18Z THEN BCMG SCATTERED DUE TO DIURNAL HTG AFT THIS TIME. LK EFFECT WL CONTINUE THRU 18Z TUE BFR HIPRES BUILDS INTO THE AREA, SHIFTING FLOW ARND TO THE NORTH AND BRINGING IN SHORT FETCH ACRS LK ONTARIO, RESULTING IN DIMINISHING SNOW SHOWERS ON TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 300 PM EST UPDATE... TUESDAY NIGHT HIGH PRESSURE WILL DOMINATE THE NORTHEAST WITH WEAK ANTICYCLONIC FLOW ALOFT. THIS WILL RESULT IN QUIET WEATHER ACROSS THE CWA. TEMPS WEDNESDAY MORNING WILL BE QUITE CHILLY AGAIN WITH LOWS REACHING AS FAR AS NEGATIVE TEN BELOW. WINDS WILL BE QUITE LIGHT SO DO NOT EXPECT ANY WIND CHILL ADVISORIES ISSUED ATTM. THERE IS A LOT OF UNCERTAINTY IN THE EXTENDED FORECAST. DECIDED TO GO CLOSELY WITH WPC GUIDANCE AS THE GFS AND THE ECMWF INDICATE VERY DIFFERENT OUTCOMES IN THE EXTENDED. BUT THE MAIN PICTURE OF THE EXTENDED IS THAT ANOTHER UPPR LVL SHORTWAVE WILL MOVE EAST ACROSS CENTRAL CANADA LATE TUES/WEDNESDAY AND START TO PUSH THE SFC RIDGE EAST AND WILL EVENTUALLY MOVE OFF THE EAST COAST BY WEDNESDAY NIGHT. THE ECMWF INDICATES THE RIDGE WILL WEAKEN AND A SFC LOW WILL MOVE NORTH AND EAST ALONG THE CAST WED NIGHT BRINGING A CHANCE FOR SNOW SHOWERS WEDNESDAY NIGHT/THURS MORNING. IF THIS OCCURS THE SHOWERS WILL IMPACT THE SE PORTIONS OF THE CWA. THE GFS SHOWS THE RIDGE WILL MAINTAIN INTENSITY WHICH WILL PREVENT THE SFC LOW FROM IMPACTING THE CWA. THE FURTHER INTO THE FORECAST THE MORE MESSY THE FORECAST BECOMES. THE GFS BRINGS A SYSTEM THROUGH OUR CWA THURS NIGHT INTO FRI BRINGING A CHANCE FOR SNOW... HOWEVER THE ECMWF BRINGS IT THROUGH A DAY LATER AND POSSIBLY RAIN/SNOW MIX. THERE WILL BE A SYSTEM THIS COMING WEEKEND... BUT CONFIDENCE IS LOW ON IMPACTS OR TIMING SO JUST KEPT CHANCE IN THE FORECAST ATTM. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... A FAST MOVING WAVE WILL MOVE ACROSS THE TERMINALS LATE THIS EVENING AND EARLY SUNDAY MORNING. A VERY DRY AIRMASS IS CURRENTLY IN PLACE, SO IT IS HARD TO IMAGINE MUCH COVERAGE IN SNOW SHOWERS. THIS LOGIC IS SUPPORTED BY THE LATEST HRRR REF PROGS, WHICH SHOWS VERY WEAK RETURNS IN WIDELY SCATTERED ACTIVITY. A BETTER LOOKING WAVE REACHES THE REGION TOMORROW AFTERNOON. LIGHT SNOW SHOWERS WILL BECOME WIDESPREAD BY MID AFTERNOON, WITH MVFR RESTRICTIONS LIKELY TO PREVAIL. TEMPO IFR VISIBILITY IS CERTAINLY POSSIBLE. A BETTER CHANCE FOR IFR WILL BE BETWEEN 18Z AND 24Z AS COVERAGE MAXIMIZES UNDER BETTER UL SUPPORT. OUTLOOK... SUN AND SUNDAY NIGHT...VFR EARLY SUNDAY DECREASING TO MVFR SUNDAY AFTERNOON AND SUNDAY NIGHT IN OCCASIONAL LGT SNOW. MON/TUE...MVFR TO IFR POSSIBLE FOR THE CNY TERMINALS...IN LAKE- EFFECT SNOW SHWRS. VFR KAVP. WED/THURS...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PVN NEAR TERM...PVN/RRM SHORT TERM...PVN LONG TERM...KAH AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
617 PM EST SAT FEB 8 2014 .SYNOPSIS... A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL KEEP A COLD...WESTERLY FLOW OF AIR OVER THE REGION INTO THE WEEKEND. A WEAK UPPER LEVEL AREA OF LOW PRESSURE WILL BRING SOME LIGHT SNOW TO THE AREA SUNDAY AFTERNOON AND NIGHT. LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO EARLY NEXT WEEK WITH ONLY MINOR ACCUMULATIONS. && .NEAR TERM /THROUGH SUNDAY/... 230 PM UPDATE... 1029 MB SFC HIPRES LOCATED ACRS OH VLY WITH VRY WEAK SFC LOW DOWN ACRS WRN NC WITH INVERTED TROF AXIS EXTENDING UP NR THE MASON-DIXON LINE BRINGING LIGHT SNOW TO VA AND WV. MODELS SUGGESTING THIS CONVERGENCE LINE NOSES NORTH THIS EVNG POSSIBLY BRINGING LGT FLURRIES TO SW AREAS EARLY ON. MAIN FCST CONCERN WL BE WV APPCHG FM IOWA TONIGHT AND WHAT AFFECT, IF ANY, THIS WL HV ON FA. IF S/WV MAINTAINS CURRENT SPEED, EXPECT LIGHT SNOW TO MV INTO WRN SXNS OF CWA BFR MIDNIGHT TONIGHT. CERTAINLY NOT IMPRESSED WITH LIFT ASSOC WITH THIS SYSTEM FOR TONIGHT. ISENTROPIC UPGLIDE ON 270K LYR PER 12Z NAM FOR SYSTEM CURRENTLY OVR ERN IOWA IS SHOWING SOME LIFT IN MOISTURE AREA WHERE SNOW IS CURRENTLY FALLING AND FOLLOWING THIS AREA EASTWARD TWD NY STATE OVERNIGHT IT TRANSITIONS TO MORE OF NEUTRAL LIFT AND/OR DOWNGLIDE AS WV HEADS INTO WRN NY AT 06Z. THUS, DO THINK THAT THERE IS STILL A CHANCE FOR LIGHT SNOW SHOWERS ACRS WRN ZONES TONIGHT WITH JUST FLURRIES ELSEWHERE. IN THESE AREAS, EXPECT JUST UNDER 1/2 INCH ACCUMS. WITH EXTENSIVE CLD CVR EXPECTED TONIGHT, ONLY EXPECT MIN TEMPS TO DROP DOWN TWD 10F BY MRNG. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... 230 PM UPDATE... ANOTHER WV WL ZIP THRU THE UPR MIDWEST TOMORROW MRNG SPREADING LGT SNOW INTO THE CWA BY AFTN. THIS WV IS CURRENTLY COMING ONSHORE IN THE PACIFIC NORTHWEST. AS IT HEADS EAST, POPS WL INCREASE AFTER 16Z WITH CATEGORICAL EXPECTED DRG THE AFTN HRS. EXPECT ARND 1 INCH OF SNOW TOMORROW AFTN, MAINLY WEST OF I-81 CORRIDOR PROCEEDING EAST FM THERE. WV WL CONTINUE TO SHIFT ACRS CWA TOMORROW NGT WITH SNOW EXITING MOST OF CWA BY 06Z. NW FLOW KICKS IN BHND WITH H8 TEMPS APPCHG -18C AND INVERSION HGTS INCRS TO NR 750MB EXPECT GOOD BAND OF LK EFFECT SNOW TO GET GOING BTWN 06Z AND 12Z MONDAY ON 290 FLOW. MAX OMEGA IS PROGGED TO BE IN DENDRITE ZONE WITH BTWN 1-2 INCHES POSSIBLE THRU THIS TIME. LK EFFECT SNOW SHOWERS WL CONTINUE THRU THE DAY MON WITH FLOW BTWN 280-290 DRG THE DAY, KEYING IN ON SYRACUSE AREA AND POINTS TO THE SOUTHEAST. EXPECT MOST OF THE SNOW TO FALL BTWN 12Z AND 18Z THEN BCMG SCATTERED DUE TO DIURNAL HTG AFT THIS TIME. LK EFFECT WL CONTINUE THRU 18Z TUE BFR HIPRES BUILDS INTO THE AREA, SHIFTING FLOW ARND TO THE NORTH AND BRINGING IN SHORT FETCH ACRS LK ONTARIO, RESULTING IN DIMINISHING SNOW SHOWERS ON TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 300 PM EST UPDATE... TUESDAY NIGHT HIGH PRESSURE WILL DOMINATE THE NORTHEAST WITH WEAK ANTICYCLONIC FLOW ALOFT. THIS WILL RESULT IN QUIET WEATHER ACROSS THE CWA. TEMPS WEDNESDAY MORNING WILL BE QUITE CHILLY AGAIN WITH LOWS REACHING AS FAR AS NEGATIVE TEN BELOW. WINDS WILL BE QUITE LIGHT SO DO NOT EXPECT ANY WIND CHILL ADVISORIES ISSUED ATTM. THERE IS A LOT OF UNCERTAINTY IN THE EXTENDED FORECAST. DECIDED TO GO CLOSELY WITH WPC GUIDANCE AS THE GFS AND THE ECMWF INDICATE VERY DIFFERENT OUTCOMES IN THE EXTENDED. BUT THE MAIN PICTURE OF THE EXTENDED IS THAT ANOTHER UPPR LVL SHORTWAVE WILL MOVE EAST ACROSS CENTRAL CANADA LATE TUES/WEDNESDAY AND START TO PUSH THE SFC RIDGE EAST AND WILL EVENTUALLY MOVE OFF THE EAST COAST BY WEDNESDAY NIGHT. THE ECMWF INDICATES THE RIDGE WILL WEAKEN AND A SFC LOW WILL MOVE NORTH AND EAST ALONG THE CAST WED NIGHT BRINGING A CHANCE FOR SNOW SHOWERS WEDNESDAY NIGHT/THURS MORNING. IF THIS OCCURS THE SHOWERS WILL IMPACT THE SE PORTIONS OF THE CWA. THE GFS SHOWS THE RIDGE WILL MAINTAIN INTENSITY WHICH WILL PREVENT THE SFC LOW FROM IMPACTING THE CWA. THE FURTHER INTO THE FORECAST THE MORE MESSY THE FORECAST BECOMES. THE GFS BRINGS A SYSTEM THROUGH OUR CWA THURS NIGHT INTO FRI BRINGING A CHANCE FOR SNOW... HOWEVER THE ECMWF BRINGS IT THROUGH A DAY LATER AND POSSIBLY RAIN/SNOW MIX. THERE WILL BE A SYSTEM THIS COMING WEEKEND... BUT CONFIDENCE IS LOW ON IMPACTS OR TIMING SO JUST KEPT CHANCE IN THE FORECAST ATTM. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... A FAST MOVING WAVE WILL MOVE ACROSS THE TERMINALS LATE THIS EVENING AND EARLY SUNDAY MORNING. A VERY DRY AIRMASS IS CURRENTLY IN PLACE, SO IT IS HARD TO IMAGINE MUCH COVERAGE IN SNOW SHOWERS. THIS LOGIC IS SUPPORTED BY THE LATEST HRRR REF PROGS, WHICH SHOWS VERY WEAK RETURNS IN WIDELY SCATTERED ACTIVITY. A BETTER LOOKING WAVE REACHES THE REGION TOMORROW AFTERNOON. LIGHT SNOW SHOWERS WILL BECOME WIDESPREAD BY MID AFTERNOON, WITH MVFR RESTRICTIONS LIKELY TO PREVAIL. TEMPO IFR VISIBILITY IS CERTAINLY POSSIBLE. A BETTER CHANCE FOR IFR WILL BE BETWEEN 18Z AND 24Z AS COVERAGE MAXIMIZES UNDER BETTER UL SUPPORT. OUTLOOK... SUN AND SUNDAY NIGHT...VFR EARLY SUNDAY DECREASING TO MVFR SUNDAY AFTERNOON AND SUNDAY NIGHT IN OCCASIONAL LGT SNOW. MON/TUE...MVFR TO IFR POSSIBLE FOR THE CNY TERMINALS...IN LAKE- EFFECT SNOW SHWRS. VFR KAVP. WED/THURS...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PVN NEAR TERM...PVN SHORT TERM...PVN LONG TERM...KAH AVIATION...DJP
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
634 PM PST SAT FEB 8 2014 .SYNOPSIS...SNOW...SLEET AND FREEZING RAIN WILL CONTINUE THIS EVENING AS LOW PRESSURE MOVES ONSHORE. LIGHTER PRECIPITATION IS EXPECTED ON SUNDAY AS RAIN IN THE SOUTH...A MIX FARTHER NORTH AND SNOW OR A MIX IN THE GORGE. ANOTHER SYSTEM ARRIVES SUNDAY NIGHT WHICH SHOULD BE RAIN FOR MOST AREAS AWAY FROM EAST COUNTY AND THE GORGE WHERE SNOW AND FREEZING RAIN HANG ON. ONSHORE FLOW AND A CONSOLIDATED PACIFIC JET WILL BRING A RETURN TO MORE TYPICAL PERIODS OF VALLEY RAIN AND MOUNTAIN SNOW AS THE WEEK PROGRESSES. RAIN MAY BE HEAVY AT TIMES WITH OCCASIONAL WINDY PERIODS. && UPDATED SHORT TERM AND AVIATION DISCUSSION .UPDATE...PRECIPITATION HAS MOSTLY CHANGED TO FREEZING RAIN EARLY THIS EVENING AROUND THE PORTLAND AND VANCOUVER METRO AREA AND WE HAVE BEEN RECEIVING SPOTTER REPORTS OF LIGHT ICE ACCUMULATIONS. LIGHT FREEZING RAIN WILL CONTINUE THROUGH THE NIGHT AND LIKELY THROUGH MOST OF SUNDAY AND HAVE CONVERTED THE WINTER STORM WARNING TO AN ICE STORM WARNING FOR THE METRO AREA. THERE MAY BE A BRIEF BREAK IN PRECIPITATION SUNDAY MORNING BUT ANOTHER ROUND OF LIGHT PRECIPITATION IS EXPECTED SUNDAY AFTERNOON AND EVENING. EASTERLY WINDS WILL CONTINUE TO BLOW THROUGH THE GORGE AND KEEPING SURFACE TEMPERATURES NEAR OR BELOW FREEZING DESPITE THE WARMING AT THE HIGHER ELEVATIONS. HAVE ALSO BEEN GETTING REPORTS OF ACCUMULATING SNOW ALONG THE SOUTH WASHINGTON COAST AND HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE SOUTH WASHINGTON COAST AND THE WILLAPA HILLS. LIKE ELSEWHERE IN THE REGION SLEET OR FREEZING RAIN WILL LIKELY MIX WITH THE SNOW TONIGHT. HARTLEY .PREVIOUS SHORT TERM DISCUSSION...TONIGHT THROUGH SUNDAY NIGHT... IF YOU CAN AVOID TRAVELING THIS EVENING...IT IS IN YOUR BEST INTEREST TO DO SO. SLEET AND FREEZING RAIN IS INCREASING. PRECIPITATION IS EXPECTED TO DECREASE AFTER MIDNIGHT. LIGHT ICE GLAZES HAVE BEEN REPORTED. AREAS NEAR THE GORGE HAVE THE HIGHEST LIKELIHOOD OF REMAINING SNOW/SLEET. THE WARM NOSE IS PUSHING ITS WAY UP THE VALLEY THIS AFTERNOON WITH FREEZING RAIN AND SLEET BECOMING THE PREDOMINANT CONDITION SOUTH OF PORTLAND METRO...WITH SNOW...SLEET AND SOME FREEZING RAIN MIXING IN TO PORTLAND AS WELL NOW. HEAR AT THE OFFICE BETWEEN THE PDX AIRPORT AND TROUTDALE WITH MORE OF A GORGE INFLUENCE...WE ARE BOUNCING BETWEEN SNOW AND SLEET. THE WARM NOSE IS NOT EVIDENT ON THE KPTV TOWER TEMPS SUCH YET AS THE LOWEST LEVELS ARE A BIT COLDER...BUT HAS REALLY BEEN CENTERED BETWEEN 925 AND 850 MB...SO BETWEEN 2500 AND 3500 FEET. MEANWHILE THE PRESSURE GRADIENT FROM TTD TO DLS HAS INCREASED TO A WHOPPING 10.8 MB...REINFORCING THAT FEED OF COLDER LOW LEVEL AIR. THERE IS STILL A NORTH-SOUTH GRADIENT FROM PORTLAND TO EUGENE THUS SURFACE TEMPERATURES IN THIS AREA HAVE NOT WARMED AND CONTINUE THE FREEZING RAIN THREAT EVEN IN THIS AREA. THE MAIN SURFACE LOW IS OFF THE OREGON COAST. IT IS AMAZING THE ARCTIC BOUNDARY THAT IS IN PLACE. NORTH BEND IS 57 WITH A DEWPOINT OF 55...ROSEBURG IS 56 WITH A DEWPOINT OF 48. MEANWHILE IT IS 30 OVER 28 AT EUGENE. AS THE LOW MOVES INLAND TONIGHT...EXPECT A SOUTH GRADIENT TO TAKE HOLD IN THE SOUTH WILLAMETTE VALLEY AND END THE FREEZING RAIN AND ICE THREAT FOR THESE AREAS. TOWARDS SALEM SOUNDING SUGGEST THAT THE SHALLOW COLD AIR DOES NOT GET ERODED...WITH THE WARM NOSE STILL OVER THE AREA. THEREFORE FREEZING RAIN THREAT WILL CONTINUE. FOR THE PORTLAND METRO AREA...HAVE TO NOW FOLLOW THE RAP FOR THE SITUATION THAT WOULD SUGGEST THIS WARM NOSE CONTINUES TO ALLOW FOR A MIX OF SNOW...SLEET AND FREEZING RAIN WITH SOME ICE COATING POSSIBLE ACROSS THE METRO AREA THIS EVENING. AT THIS POINT WIDESPREAD ICING IS NOT EXPECTED WITH THE REINFORCING SHOT OF COLD AIR KEEPING A DEEP LOWER LAYER...BUT LIGHT GLAZING ON TOP THE SNOW TODAY WILL MAKE FOR HAZARDOUS ROAD CONDITIONS. THAT BEING SAID...AS THE SURFACE LOW MOVES INLAND ADDITIONAL FRONTOGENETICAL FORCING WILL MEAN THE SIGNIFICANT PRECIPITATION IS STILL POSSIBLE. THIS MAY MEAN ICE ACCUMULATIONS UP TO ONE QUARTER OF AN INCH. THE MESSAGE FROM EARLIER STILL HOLDS...IF YOU CAN AVOID TRAVELING THIS EVENING...IT IS IN YOUR SAFETY TO DO JUST THAT. THE MAIN UPPER WAVE OFF THE COAST AND THE SURFACE LOW WILL MOVE INLAND AND WEAKEN OVERNIGHT. THIS WILL MEAN MUCH LIGHTER PRECIPITATION EXCEPT IN THE CASCADES. ANOTHER LOW WILL PASS BY TO OUR SOUTH ON SUNDAY AND WE GET IN ON LIGHTER DEFORMATION PRECIP WITH ADDITIONAL PACIFIC ENERGY GRAZING THE NORTH. PRECIPITATION TYPE FROM EUGENE NORTH TO SALEM LOOKS TO BE MOSTLY RAIN...FROM ABOUT SALEM NORTH IT LOOKS LIKE THE FREEZING RAIN THREAT STILL EXISTS AT LEAST THROUGH THE MORNING...AND THEN RAIN WILL START TO MIX IN THE CENTRAL VALLEY. THE COLD AIR HANGS ON IN THE NORTH TO THE PORTLAND METRO AREA. PRECIP RATES DO LOOK LIGHTER. THE NEXT MORE ORGANIZED WAVE COMES IN LATER SUNDAY NIGHT INTO EARLY MONDAY. MOST AREAS AWAY FROM EAST COUNTY AND THE GORGE SHOULD HAVE ENOUGH OF AN SOUTH GRADIENT BY THIS TIME TO CONVERT TO RAIN. MORE SOLID PRECIPITATION ARRIVES LATE AND INTO MONDAY MORNING WHERE PORTLAND AND TROUTDALE COULD BE RAIN OR POSSIBLY STILL FREEZING RAIN. THE GORGE REMAINS FREEZING RAIN OR SNOW INTO THIS SYSTEM. /KMD .LONG TERM... MONDAY THROUGH TUESDAY...MOST ALL AREAS WILL BE MILDER BY MON AM...WITH TEMPERATURES ABOVE FREEZING. HOWEVER...WITH COLD AIR STILL LOCKED IN THE COLUMBIA BASIN...SUB FREEZING AIR WILL CONTINUE THROUGH THE GORGE. THIS KEEP AREAS OF FREEZING RAIN IN THE GORGE AND UPPER HOOD RIVER VALLEY DURING THE MORNING. BY AFTERNOON...MILDER AIR WILL FINALLY REACH THOSE AREAS...WITH GRADUAL WARM UP. PORTIONS OF THE PORTLAND-VANCOUVER METRO AREA...ESPECIALLY NEAR THE GORGE MAY STILL SEE SOME WINTRY MIX OF SNOW...SLEET...FREEZING RAIN. FORTUNATELY THERE AREAS SHOULD BE IN A PCPN LULL AT THAT TIME SO ACCUMULATIONS WOULD BE LIGHT. TUESDAY NIGHT THROUGH SATURDAY...MODELS ALL INDICATE A MUCH MORE PROGRESSIVE AND WET PATTERN OVER THE REGION FOR NEXT WEEK. THIS WILL BRING RAIN...WITH SNOW CONFINED TO THE HIGHER CASCADES. WITH SUCH A PROGRESSIVE PATTERN MODELS WILL LIKELY HAVE DIFFICULTY TIMING THE INDIVIDUAL SHORTWAVES.WITH THAT SAID...CURRENT TIMING OF THE SIGNIFICANT SHORTWAVES PASSING ACROSS REGION ON TUE/WED WITH ANOTHER STRONG FRONT ON THU AND AGAIN SAT. THESE WILL BRING FAIRLY DECENT ROUND OF RAIN. THE MOUNTAINS COULD SEE SEVERAL INCHES OF PCPN WITH THE LOWLAND RECEIVING AN INCH OR TWO IN THE TUE-THU TIME FRAME. SNOW LEVELS LIKELY VARY BETWEEN 3500 AND 5000 FEET. IT LOOKS GOOD FOR BUILDING THE SNOWPACK IN THE CASCADES./MH && .UPDATED AVIATION...PRECIPITATION HAS SWITCHED OVER TO FREEZING RAIN FOR MOST LOCATIONS THIS EVENING...AND THIS WILL CONTINUE TO FALL FAIRLY HEAVILY THROUGH 06Z OR 07Z. EXPECT MAINLY MVFR CONDITIONS...WITH SOME POCKETS OF IFR DURING THIS TIME PERIOD. PRECIPITATION SHOULD BEGIN TO TAPER OFF AFTER MIDNIGHT...WITH MORE HIGH-END MVFR TO LOW-END VFR OVERNIGHT. ELEVATED TERRAIN WILL BE OBSCURED AND ICING WILL CONTINUE TO BE A SIGNIFICANT PROBLEM THROUGH SUNDAY AS A WARM NOSE ALOFT CONTINUES TO WORK ITS WAY IN WHILE SURFACE TEMPS REMAIN NEAR OR BELOW FREEZING. EXPECT PRECIPITATION TO GRADUALLY CHANGE TO ALL RAIN ALONG THE COAST AND IN THE SOUTHERN WILLAMETTE VALLEY AFTER 06Z. IN THE NORTHERN VALLEY...THE SWITCHOVER TO RAIN WILL LIKELY NOT OCCUR UNTIL SOMETIME DURING THE DAY SUNDAY. EXPECT ALL RAIN BY SUNDAY AFTERNOON EXPECT IN THE COLUMBIA RIVER GORGE. KPDX AND APPROACHES...FREEZING RAIN HAS DEVELOPED FOR MOST OF THE METRO AREA. EXPECT IT TO CONTINUE FALLING AT A MODERATE RATE THROUGH ABOUT 06Z...WITH MVFR CONDITIONS CONTINUING. PRECIPITATION INTENSITY SHOULD DECREASE OVERNIGHT...WITH CONDITIONS OF HIGH END MVFR OR LOW END VFR. EXPECT SOME LIGHT FREEZING RAIN OR DRIZZLE TO CONTINUE INTO SUN MORNING. KTTD- KDLS GRADIENT HAS SPIKED TO NEARLY -11 MB AT 22Z AS THE SURFACE LOW DEEPENS AS IT GETS CLOSER TO THE COAST. EXPECT EAST WIND 20G30KT AT THE TERMINAL AND GUSTS 30-40KT AT KTTD FOR THE NEXT FEW HOURS. THE GRADIENT WEAKENS OVERNIGHT. PYLE && .MARINE...A 1001 MB SURFACE LOW ABOUT 100 NM WEST OF FLORENCE AT 21Z CONTINUES TO DEEPEN AND TRACK E-NE. THIS HAS RESULTED IN PROLONGED SMALL CRAFT ADVISORY WIND OVER THE NRN WATERS AND INCREASED WIND OVER THE SRN WATERS. THEREFORE...HAVE EXTENDED THE SMALL CRAFT ADVISORY FOR WIND OVER THE NRN WATERS THROUGH 06Z SUN AND PUT UP AN ADVISORY FOR THE SRN WATERS THROUGH 03Z. MODELS SHOW THE LOW MAKING LANDFALL AROUND 03Z SOMEWHERE BETWEEN NEWPORT AND JUST S OF TILLAMOOK. WIND WILL QUICKLY DROP OFF AS THE LOW MOVES INLAND AND WEAKENS. WILL NEED TO WATCH FOR INCREASING SOUTH WIND OVER THE FAR SRN WATERS THIS EVENING AND OVERNIGHT. GFS SHOWS 20-25 KT S-SW WIND ACROSS THE FAR SRN WATERS. ANOTHER ROUND OF SMALL CRAFT ADVISORY WIND IS EXPECTED SUN NIGHT AND MON...FOLLOWED BY AN EVEN STRONGER SYSTEM TUE NIGHT AND WED THAT COULD PRODUCE GALES. SEAS RUNNING A COUPLE FEET HIGHER THAN GUIDANCE THIS MORNING. BUOY REPORTS AT 22Z SHOWING 6-7 FT...DESPITE THE EAST WIND. HAVE NUDGED SEAS UP A FOOT OR SO TODAY AND TONIGHT. WILL NEED TO WATCH FOR SQUARE-SEAS...SUCH AS 8 FT AT 8 SECONDS...RESULTING IN STEEP WAVES REQUIRING A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS. SEAS TO REMAIN BELOW 10 FT THROUGH MON NIGHT. SWELL THROUGH MON NIGHT WILL BE DOMINATED BY A SHORT PERIOD FRESH SWELL FROM THE S TO SW. LATEST WAVE GUIDANCE INDICATES SEAS BUILDING TO THE MID TEENS NEXT TUE. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR CASCADES IN LANE COUNTY-CENTRAL COLUMBIA RIVER GORGE-COAST RANGE OF NORTHWEST OREGON-NORTHERN OREGON CASCADES-UPPER HOOD RIVER VALLEY-WESTERN COLUMBIA RIVER GORGE. ICE STORM WARNING UNTIL 4 AM PST SUNDAY FOR CENTRAL WILLAMETTE VALLEY-NORTHERN OREGON CASCADE FOOTHILLS. ICE STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CASCADE FOOTHILLS IN LANE COUNTY-SOUTH WILLAMETTE VALLEY. ICE STORM WARNING UNTIL 10 PM PST SUNDAY FOR GREATER PORTLAND METRO AREA. WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR LOWER COLUMBIA. WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL COAST RANGE OF WESTERN OREGON. WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTH OREGON COAST. WA...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR CENTRAL COLUMBIA RIVER GORGE-WESTERN COLUMBIA RIVER GORGE. ICE STORM WARNING UNTIL 10 PM PST SUNDAY FOR GREATER VANCOUVER AREA. WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR I-5 CORRIDOR IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS-SOUTH WASHINGTON COAST-WILLAPA HILLS. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PST THIS EVENING FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. && $$ MORE WEATHER INFORMATION ONLINE AT.. HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV 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 PORTLAND OR
409 PM PST SAT FEB 8 2014 .SYNOPSIS...SNOW...SLEET AND FREEZING RAIN WILL CONTINUE THIS EVENING AS LOW PRESSURE MOVES ONSHORE. LIGHTER PRECIPITATION IS EXPECTED ON SUNDAY AS RAIN IN THE SOUTH...A MIX FARTHER NORTH AND SNOW OR A MIX IN THE GORGE. ANOTHER SYSTEM ARRIVES SUNDAY NIGHT WHICH SHOULD BE RAIN FOR MOST AREAS AWAY FROM EAST COUNTY AND THE GORGE WHERE SNOW AND FREEZING RAIN HANG ON. ONSHORE FLOW AND A CONSOLIDATED PACIFIC JET WILL BRING A RETURN TO MORE TYPICAL PERIODS OF VALLEY RAIN AND MOUNTAIN SNOW AS THE WEEK PROGRESSES. RAIN MAY BE HEAVY AT TIMES WITH OCCASIONAL WINDY PERIODS. && .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT... IF YOU CAN AVOID TRAVELING THIS EVENING...IT IS IN YOUR BEST INTEREST TO DO SO. SLEET AND FREEZING RAIN IS INCREASING. PRECIPITATION IS EXPECTED TO DECREASE AFTER MIDNIGHT. LIGHT ICE GLAZES HAVE BEEN REPORTED. AREAS NEAR THE GORGE HAVE THE HIGHEST LIKELIHOOD OF REMAINING SNOW/SLEET. THE WARM NOSE IS PUSHING ITS WAY UP THE VALLEY THIS AFTERNOON WITH FREEZING RAIN AND SLEET BECOMING THE PREDOMINANT CONDITION SOUTH OF PORTLAND METRO...WITH SNOW...SLEET AND SOME FREEZING RAIN MIXING IN TO PORTLAND AS WELL NOW. HEAR AT THE OFFICE BETWEEN THE PDX AIRPORT AND TROUTDALE WITH MORE OF A GORGE INFLUENCE...WE ARE BOUNCING BETWEEN SNOW AND SLEET. THE WARM NOSE IS NOT EVIDENT ON THE KPTV TOWER TEMPS SUCH YET AS THE LOWEST LEVELS ARE A BIT COLDER...BUT HAS REALLY BEEN CENTERED BETWEEN 925 AND 850 MB...SO BETWEEN 2500 AND 3500 FEET. MEANWHILE THE PRESSURE GRADIENT FROM TTD TO DLS HAS INCREASED TO A WHOPPING 10.8 MB...REINFORCING THAT FEED OF COLDER LOW LEVEL AIR. THERE IS STILL A NORTH-SOUTH GRADIENT FROM PORTLAND TO EUGENE THUS SURFACE TEMPERATURES IN THIS AREA HAVE NOT WARMED AND CONTINUE THE FREEZING RAIN THREAT EVEN IN THIS AREA. THE MAIN SURFACE LOW IS OFF THE OREGON COAST. IT IS AMAZING THE ARCTIC BOUNDARY THAT IS IN PLACE. NORTH BEND IS 57 WITH A DEWPOINT OF 55...ROSEBURG IS 56 WITH A DEWPOINT OF 48. MEANWHILE IT IS 30 OVER 28 AT EUGENE. AS THE LOW MOVES INLAND TONIGHT...EXPECT A SOUTH GRADIENT TO TAKE HOLD IN THE SOUTH WILLAMETTE VALLEY AND END THE FREEZING RAIN AND ICE THREAT FOR THESE AREAS. TOWARDS SALEM SOUNDING SUGGEST THAT THE SHALLOW COLD AIR DOES NOT GET ERODED...WITH THE WARM NOSE STILL OVER THE AREA. THEREFORE FREEZING RAIN THREAT WILL CONTINUE. FOR THE PORTLAND METRO AREA...HAVE TO NOW FOLLOW THE RAP FOR THE SITUATION THAT WOULD SUGGEST THIS WARM NOSE CONTINUES TO ALLOW FOR A MIX OF SNOW...SLEET AND FREEZING RAIN WITH SOME ICE COATING POSSIBLE ACROSS THE METRO AREA THIS EVENING. AT THIS POINT WIDESPREAD ICING IS NOT EXPECTED WITH THE REINFORCING SHOT OF COLD AIR KEEPING A DEEP LOWER LAYER...BUT LIGHT GLAZING ON TOP THE SNOW TODAY WILL MAKE FOR HAZARDOUS ROAD CONDITIONS. THAT BEING SAID...AS THE SURFACE LOW MOVES INLAND ADDITIONAL FRONTOGENETICAL FORCING WILL MEAN THE SIGNIFICANT PRECIPITATION IS STILL POSSIBLE. THIS MAY MEAN ICE ACCUMULATIONS UP TO ONE QUARTER OF AN INCH. THE MESSAGE FROM EARLIER STILL HOLDS...IF YOU CAN AVOID TRAVELING THIS EVENING...IT IS IN YOUR SAFETY TO DO JUST THAT. THE MAIN UPPER WAVE OFF THE COAST AND THE SURFACE LOW WILL MOVE INLAND AND WEAKEN OVERNIGHT. THIS WILL MEAN MUCH LIGHTER PRECIPITATION EXCEPT IN THE CASCADES. ANOTHER LOW WILL PASS BY TO OUR SOUTH ON SUNDAY AND WE GET IN ON LIGHTER DEFORMATION PRECIP WITH ADDITIONAL PACIFIC ENERGY GRAZING THE NORTH. PRECIPITATION TYPE FROM EUGENE NORTH TO SALEM LOOKS TO BE MOSTLY RAIN...FROM ABOUT SALEM NORTH IT LOOKS LIKE THE FREEZING RAIN THREAT STILL EXISTS AT LEAST THROUGH THE MORNING...AND THEN RAIN WILL START TO MIX IN THE CENTRAL VALLEY. THE COLD AIR HANGS ON IN THE NORTH TO THE PORTLAND METRO AREA. PRECIP RATES DO LOOK LIGHTER. THE NEXT MORE ORGANIZED WAVE COMES IN LATER SUNDAY NIGHT INTO EARLY MONDAY. MOST AREAS AWAY FROM EAST COUNTY AND THE GORGE SHOULD HAVE ENOUGH OF AN SOUTH GRADIENT BY THIS TIME TO CONVERT TO RAIN. MORE SOLID PRECIPITATION ARRIVES LATE AND INTO MONDAY MORNING WHERE PORTLAND AND TROUTDALE COULD BE RAIN OR POSSIBLY STILL FREEZING RAIN. THE GORGE REMAINS FREEZING RAIN OR SNOW INTO THIS SYSTEM. /KMD .LONG TERM... MONDAY THROUGH TUESDAY...MOST ALL AREAS WILL BE MILDER BY MON AM...WITH TEMPERATURES ABOVE FREEZING. HOWEVER...WITH COLD AIR STILL LOCKED IN THE COLUMBIA BASIN...SUB FREEZING AIR WILL CONTINUE THROUGH THE GORGE. THIS KEEP AREAS OF FREEZING RAIN IN THE GORGE AND UPPER HOOD RIVER VALLEY DURING THE MORNING. BY AFTERNOON...MILDER AIR WILL FINALLY REACH THOSE AREAS...WITH GRADUAL WARM UP. PORTIONS OF THE PORTLAND-VANCOUVER METRO AREA...ESPECIALLY NEAR THE GORGE MAY STILL SEE SOME WINTRY MIX OF SNOW...SLEET...FREEZING RAIN. FORTUNATELY THERE AREAS SHOULD BE IN A PCPN LULL AT THAT TIME SO ACCUMULATIONS WOULD BE LIGHT. TUESDAY NIGHT THROUGH SATURDAY...MODELS ALL INDICATE A MUCH MORE PROGRESSIVE AND WET PATTERN OVER THE REGION FOR NEXT WEEK. THIS WILL BRING RAIN...WITH SNOW CONFINED TO THE HIGHER CASCADES. WITH SUCH A PROGRESSIVE PATTERN MODELS WILL LIKELY HAVE DIFFICULTY TIMING THE INDIVIDUAL SHORTWAVES.WITH THAT SAID...CURRENT TIMING OF THE SIGNIFICANT SHORTWAVES PASSING ACROSS REGION ON TUE/WED WITH ANOTHER STRONG FRONT ON THU AND AGAIN SAT. THESE WILL BRING FAIRLY DECENT ROUND OF RAIN. THE MOUNTAINS COULD SEE SEVERAL INCHES OF PCPN WITH THE LOWLAND RECEIVING AN INCH OR TWO IN THE TUE-THU TIME FRAME. SNOW LEVELS LIKELY VARY BETWEEN 3500 AND 5000 FEET. IT LOOKS GOOD FOR BUILDING THE SNOWPACK IN THE CASCADES./MH && .AVIATION...WIDE RANGE OF FLIGHT CONDITIONS THIS AFTERNOON AS WELL AS A MIX OF PRECIP TYPES. EXPECT MAINLY MVFR WITH AREAS OF IFR THROUGH MIDNIGHT. SHOULD SEE MORE MVFR TO LOW-END VFR AFTER 08Z SUN. PRECIP TYPE WILL BE A CHALLENGE. HIGH CONFIDENCE IN -FZRA IN THE CENTRAL AND SOUTH WILLAMETTE VALLEY...AND OREGON CASCADE FOOTHILLS THROUGH 06Z SUN. NORTH WILLAMETTE VALLEY AND SW WA LIKELY TO BE IFR IN SNOW THROUGH 06Z SUN. PRECIP DIMINISHES AFTER 06Z...BUT STILL EXPECT WIDESPREAD IFR TO MVFR. ELEVATED TERRAIN WILL BE OBSCURED AND ICING WILL BECOME MORE OF A SIGNIFICANT FLIGHT ISSUE THROUGH SUN MORNING...ESPECIALLY OVER THE SRN PART OF THE AREA AS WARMER AIR ALOFT WORKS ITS WAY NORTH. KPDX AND APPROACHES...A COUPLE BANDS OF SNOW ON KRTX DUAL-POL DOPPLER RADAR WILL IMPACT THE TERMINAL AND APPROACHES THROUGH 00Z. EXPECT MAINLY IFR TO MVFR THROUGH 03Z...THEN A MIX OF MVFR TO LOW-END VFR THEREAFTER. PRECIP TO REMAIN AS SNOW THROUGH AT LEAST 03Z SUN...AND POSSIBLY AS LONG AS 06Z. CHANGE TO -FZRA LIKELY AFTER 06Z BUT MAY NOT OCCUR UNTIL AS LATE AS 12Z. FORTUNATELY PRECIP WILL BE DIMINISHING AFTER 06Z. KTTD-KDLS GRADIENT HAS SPIKED TO NEARLY -11 MB AT 22Z AS THE SURFACE LOW DEEPENS AS IT GETS CLOSER TO THE COAST. EXPECT EAST WIND 20G30KT AT THE TERMINAL AND GUSTS 30-40KT AT KTTD FOR THE NEXT FEW HOURS. THE GRADIENT WEAKENS OVERNIGHT. WEISHAAR && .MARINE...A 1001 MB SURFACE LOW ABOUT 100 NM WEST OF FLORENCE AT 21Z CONTINUES TO DEEPEN AND TRACK E-NE. THIS HAS RESULTED IN PROLONGED SMALL CRAFT ADVISORY WIND OVER THE NRN WATERS AND INCREASED WIND OVER THE SRN WATERS. THEREFORE...HAVE EXTENDED THE SMALL CRAFT ADVISORY FOR WIND OVER THE NRN WATERS THROUGH 06Z SUN AND PUT UP AN ADVISORY FOR THE SRN WATERS THROUGH 03Z. MODELS SHOW THE LOW MAKING LANDFALL AROUND 03Z SOMEWHERE BETWEEN NEWPORT AND JUST S OF TILLAMOOK. WIND WILL QUICKLY DROP OFF AS THE LOW MOVES INLAND AND WEAKENS. WILL NEED TO WATCH FOR INCREASING SOUTH WIND OVER THE FAR SRN WATERS THIS EVENING AND OVERNIGHT. GFS SHOWS 20-25 KT S-SW WIND ACROSS THE FAR SRN WATERS. ANOTHER ROUND OF SMALL CRAFT ADVISORY WIND IS EXPECTED SUN NIGHT AND MON...FOLLOWED BY AN EVEN STRONGER SYSTEM TUE NIGHT AND WED THAT COULD PRODUCE GALES. SEAS RUNNING A COUPLE FEET HIGHER THAN GUIDANCE THIS MORNING. BUOY REPORTS AT 22Z SHOWING 6-7 FT...DESPITE THE EAST WIND. HAVE NUDGED SEAS UP A FOOT OR SO TODAY AND TONIGHT. WILL NEED TO WATCH FOR SQUARE-SEAS...SUCH AS 8 FT AT 8 SECONDS...RESULTING IN STEEP WAVES REQUIRING A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS. SEAS TO REMAIN BELOW 10 FT THROUGH MON NIGHT. SWELL THROUGH MON NIGHT WILL BE DOMINATED BY A SHORT PERIOD FRESH SWELL FROM THE S TO SW. LATEST WAVE GUIDANCE INDICATES SEAS BUILDING TO THE MID TEENS NEXT TUE. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR CASCADES IN LANE COUNTY-CENTRAL COLUMBIA RIVER GORGE-COAST RANGE OF NORTHWEST OREGON-GREATER PORTLAND METRO AREA-NORTHERN OREGON CASCADES-UPPER HOOD RIVER VALLEY-WESTERN COLUMBIA RIVER GORGE. ICE STORM WARNING UNTIL 4 AM PST SUNDAY FOR CENTRAL WILLAMETTE VALLEY-NORTHERN OREGON CASCADE FOOTHILLS. ICE STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CASCADE FOOTHILLS IN LANE COUNTY-SOUTH WILLAMETTE VALLEY. WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR LOWER COLUMBIA. WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL COAST RANGE OF WESTERN OREGON. WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTH OREGON COAST. WA...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY FOR CENTRAL COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-WESTERN COLUMBIA RIVER GORGE. WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR I-5 CORRIDOR IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PST THIS EVENING FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. && $$ MORE WEATHER INFORMATION ONLINE AT.. HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV 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...UPDATED
NWS PORTLAND OR
1034 AM PST FRI FEB 7 2014 UPDATED AVIATION AND MARINE DISCUSSIONS .SYNOPSIS...THE SECOND SYSTEM IN A ONE-TWO-THREE PUNCH OF WINTRY WEATHER FOR NORTHWEST OREGON IS DEVELOPING OFFSHORE...AND WILL SPREAD SNOW NORTHEAST ACROSS THE FORECAST AREA TODAY. SEVERAL INCHES OF SNOW ARE LIKELY FOR MOST OF OUR NORTHWEST OREGON ZONES BY SATURDAY MORNING...EVENTUALLY CHANGING TO SLEET AND FREEZING RAIN FROM THE SOUTH. SOUTHWEST WASHINGTON WILL BE ON THE NORTHERN FRINGE OF THE HEAVIER PRECIPITATION...WITH MAINLY AREAS NEAR THE COLUMBIA RIVER AFFECTED. THE THIRD SYSTEM WILL BRING MORE WINTRY WEATHER TO OUR AREA LATER SATURDAY INTO SUNDAY...BUT THERE IS STILL A BIT OF UNCERTAINTY IN HOW FAR NORTH THIS SYSTEMS IMPACTS WILL REACH. OVERALL A VERY COMPLEX WINTER WEATHER SITUATION UNFOLDING OVER SOUTHWEST WASHINGTON AND NORTHWEST OREGON THROUGH SUNDAY. NEXT WEEK THERE WILL BE A TURN TOWARD MORE TYPICAL WEATHER FOR THE REGION WITH MILDER PACIFIC FRONTAL SYSTEMS BRINGING PERIODS OF RAIN. && .UPDATE...SNOW IS PROGRESING UP THE VALLEY...AND SPED UP THE POPS THIS AFTERNOON. THUS EXPECT SNOW TO BEGIN SOONER THAN EARLIER FORECAST. ALSO...CAMERAS IN NEWPORT SHOW LIQUID PRECIP AND TEMPS ARE AROUND 30. EXPECT SOME FREEZING RAIN IN THESE AREAS...AND UP TO A TENTH INCH HAS BEEN REPORTED IN SILETZ. FARTHER INLAND STILL THINK SNOW WILL BE THE DOMINANT PRECIP TYPE AS THE RAWS STATIONS ARE UNCHANGED FROM EARLIER. THAT SAID THE RAP 925 TEMPERATURE IS TRACKING FAIRLY WELL IF NOT A LITTLE SNOW FOR THE WARM NOSE. IF THE RAP IS TRUE...THIS WOULD SUGGEST A TRANSITION TO FREEZING RAIN OR SLEET THIS AFTERNOON. WILL CONTINUING HEDGING THE FORECAST IN THIS DIRECTION. THE SOUTH CENTRAL COAST NEAR FLORENCE SHOULD BE JUST RAIN BASED ON OBS AND CAMERAS. NOWCAST COMING OUT SOON. /KMD REST OF THE MORNING UPDATE UNCHAGED...NO BIG CHANGES FOR THE MORNING UPDATE. SNOW HAS STARTED TO FALL IN EUGENE BASED ON REPORTS WITH A FRESH COATING EARLIER AND NOW COMING DOWN HARDER. EXPECT THIS IS LOW LEVEL FORCED AS THE UPPER FORCING IS STILL A BIT FARTHER OFFSHORE. WHILE SNOW IS THE INITIAL PRECIPITATION TYPE AND SHOULD BE FOR A WHILE IN THE SOUTH... AS MODELS SUGGEST THE WARM NOSE AT 925/850 STAYS SOUTH THROUGH 0Z. SO INITIAL CONCERNS FOR FREEZING RAIN ARE TOO HIGH JUST YET. THAT SAID... CONCERNS ARE SOMEWHAT HIGHER FOR FREEZING RAIN/ICING SITUATION AT LEAST FOR PARTS OF THE CENTRAL OREGON COAST...COAST RANGE...SOUTH WILLAMETTE VALLEY...AND THE LOWER VALLEYS IN THE LANE COUNTY CASCADES LATER THIS AFTERNOON. OBSERVATIONS THIS MORNING SHOW A THICK DIVIDING LINE BETWEEN WARMER SURFACE AIR AT THE COAST WHERE IT IS IN THE LOW TO MID 30S AT WALDPORT...YACHATS AND FLORENCE...MEANWHILE OFFSHORE FLOW MAINTAINS COLDER AIR FROM NEWPORT NORTH. A SIMILIAR STORY IS THE CASE WHERE IT IS 40 AND RAINING IN ROSEBURG AND 21 IN EUGENE. MEANWHILE...A TELLING TALE OF WHAT TO MONITOR TODAY MAY BE THE RAWS STATIONS IN THE CENTRAL OREGON COAST RANGE. HIGH POINT AND GOODWIN PEAK ARE GOOD ONES AT JUST UNDER 2000 FT...AND ARE LOCATED AT TO THE SOUTHWEST OF EUGENE. THESE STATIONS SIT AT AROUND 32 DEGREES WITH SIMILAR DEWPOINT VALUES AND MAINTAIN A WEAK OR A SOUTH WIND. NOW THESE STATIONS WERE A LITTLE WARMER LAST EVENING WHEN FREEZING RAIN MIXED IN. MEANWHILE VILLAGE CREEK AND WILKINSON RIDGE RAWS JUST A BIT FARTHER NORTH IN THE COAST RANGE...WHICH ARE LOCATED BETWEEN EUGENE AND CORVALLIS AND AT 1500 FT ELEVATION...SIT AT 25 AND 26. THIS IS POTENTIALLY THE HIGHEST IMPACT WEATHER...EVEN THOUGH ANOTHER ROUND OF WIDESPREAD SNOW IS AGAIN EXPECTED ACROSS THE AREA. THIS IS SOMEWHAT OF A UNIQUE SITUATION IN THAT IT IS NOT COMMON FOR OUR AREA TO GO FROM SNOW TO FREEZING RAIN AND BACK TO SNOW...THUS THE CONCERN...BUT THERE IS ALWAYS A FIRST FOR EVERYTHING. THE MODELS ARE ALREADY BRINING THE LOWEST LEVEL COLD AIR TOO FAST...BUT AS THE SURFACE LOW TRACKS IN IT LOOKS LIKE THE COAST WILL SEE A PERIOD OF FREEZING RAIN AND THEN IF THE LOW GOES. SOMETHING WE HAVEN`T SEEN MUCH OF...BUT THERE ARE A FEW LIGHTNING STRIKES WELL OFFSHORE OF THE MOUTH OF THE COLUMBIA RIVER NEAR THE MID LEVEL DRY SLOT AND WHERE THE CURRENT DOMINATING SURFACE LOW IS. MODELS ARE IN FAIR AGREEMENT THAT THE JET ENERGY TO THE SOUTH WILL ALLOW THE LOW MUCH FARTHER OFFSHORE AND TO THE SOUTH TO DOMINATE. WHERE THEY DIFFER IS HOW FAR NORTH THE LOW LEVEL WARM AIR SPREADS. THIS MAKES THE DIFFERENCE BETWEEN A BUNCH OF ICE FROM NEWPORT NORTH WITH THE SECOND PUNCH COMING IN LATER TODAY AND TONIGHT. MODELS DO GENERALLY AGREE THAT AT LEAST THROUGH 12Z SATURDAY THAT THE FREEZING RAIN THREAT IN THE VALLEY REMAINS FROM SALEM SOUTH. IF YOU BELIEVE NATIONAL GUIDANCE AND THE RAW MOS GUIDANCE...EUGENE WILL SWITCH TO RAIN. DONT THINK THAT WILL HAPPEN. MODELS DO GENERALLY AGREE THAT AT LEAST THROUGH 12Z SATURDAY THAT THE FREEZING RAIN THREAT IN THE VALLEY REMAINS FROM SALEM SOUTH. THAT IS NOT A GUARANTEE AS GFS/NAM BUFR SOUNDINGS BRING THE WARM NOSE AWFULLY CLOSE...BUT THE CURRENT FEELING RIGHT NOW. WILL KEEP A CHANCE THERE LATE TONIGHT INTO EARLY SATURDAY AS GFS/NAM BUFR SOUNDINGS BRING THE WARM NOSE AWFULLY CLOSE. NOT TO IGNORE AREAS FARTHER NORTH...PROFILES ARE ALL SNOW,. THERE IS PLENTY OF LOW LEVEL FRONTOGENETICAL FORCING WHICH IS MORE LOOSELY ORGANIZED OFFSHORE BUT WILL PICK UP THIS AFTERNOON OVER THE AREA AS THE CLASH OF THE COLD AND MILD PACIFIC AIR COMMENCES AGAIN FARTHER NORTH. THIS WILL ALLOW PRECIPITATION IN THE FORM OF SNOW TO GET GOING THIS AFTERNOON AND EVENING AND AGAIN EXPECT BANDING TO OCCUR...LIKELY FARTHER NORTH THAN THE MODELS ARE SHOWING. /KMD && .SHORT TERM...AGAIN OUR APOLOGIES FOR THE TARDINESS OF THIS DISCUSSION... THIS SHIFT HAS BEEN VERY BUSY ON MANY FRONTS...BOTH LITERALLY AND FIGURATIVELY. FIRST THINGS FIRST...AS MOST OF US KNOW BY NOW WEAK LOW PRESSURE BROUGHT SIGNIFICANT SNOWFALL FOR JUST ABOUT THE ENTIRE FORECAST AREA...WITH AS MUCH AS A FOOT OF SNOW IN SOUTHERN PORTIONS OF THE WILLAMETTE VALLEY AND CLOSE TO THAT IN THE COAST RANGE. LOW PRESSURE TOOK THE PERFECT TRACK NORTHEAST INTO THE FORECAST AREA...WITH ITS ASSOCIATED FRONT OF MOIST AND RELATIVELY MILD PACIFIC AIR OCCLUDING AS IT MOVED INTO A BURLY ARCTIC AIR MASS ENTRENCHED OVER THE PACIFIC NORTHWEST. ALL WARNINGS AND ADVISORIES FOR THIS SYSTEM HAVE ENDED IN OUR FORECAST AREA...AS THIS SYSTEM HAS SINCE SHIFTED ITS FOCUS EAST INTO THE COLUMBIA BASIN AND SPOKANE AREA. THE REASON FOR THE RECAP IS THAT THIS IS ALMOST EXACTLY WHAT WILL HAPPEN AGAIN LATER TODAY INTO TONIGHT. BROAD AND ELONGATED UPPER LEVEL LOW PRESSURE EXTENDS FROM VANCOUVER ISLAND WESTWARD INTO THE PACIFIC. A VORT LOBE IS POSITIONED NEAR 47N/133W...ALMOST EXACTLY WHERE THURSDAYS VORT LOBE WAS POSITIONED THIS TIME YESTERDAY. MSAS ANALYSIS AND IR IMAGERY INDICATE A SURFACE REFLECTION VERY NEARBY AT ABOUT 45N/132W. ONE DIFFERENCE IS THAT THIS SYSTEM IS BEGINNING TO TAP INTO DEEPER MOISTURE...WITH A NARROW PLUME EXTENDING SOUTHWEST ALL THE WAY TO HAWAII. AS A RESULT MODELS ARE SHOWING MORE IMPRESSIVE QPF WITH THIS SYSTEM...AS WELL AS A STRONGER SURGE OF WARM AIR ALOFT WHICH SHOULD EVENTUALLY CHANGE SNOW TO SLEET AND FREEZING RAIN IN THE EUGENE AREA AND POSSIBLY FARTHER NORTH LATER TODAY AND TONIGHT. OVERRUNNING PRECIPITATION IS ALREADY BEGINNING TO SPREAD INTO FAR SW OREGON... THIS WILL CONTINUE NORTHEASTWARD THROUGHOUT THE DAY AS THE VORT LOBE TEAMS UP WITH THIS WILL BE A COMPLEX PRECIPITATION TYPE FORECAST...WITH COLD AIR TRAPPED IN THE WILLAMETTE VALLEY. TO SHOW THE CONTRAST...AT 5 AM THE TEMPERATURE WAS 21 DEGREES IN EUGENE AND 40 DEGREES IN ROSEBURG. PRESSURE GRADIENTS REMAIN NORTHERLY THROUGH THE WILLAMETTE VALLEY... SO THIS LOW LEVEL COLD AIR IS NOT GOING ANYWHERE SOON. USING 4KM UW WRFGFS SOUNDINGS ALONE...IT WOULD SEEM ENOUGH WARM AIR WOULD ADVECT INTO EUGENE TO PUSH THEIR TEMPS WELL INTO THE 30S AND CHANGE PRECIPITATION TO RAIN. NAM BUFR SOUNDINGS SHOW AN EVEN MORE DRAMATIC WARMUP. HOWEVER...AS LONG AS PRESSURE GRADIENTS THROUGH THE WILLAMETTE VALLEY REMAIN NORTHERLY...THERE WILL WILL CONTINUE TO BE A THREAT OF FROZEN/FREEZING PRECIPITATION. WITH QPF INCREASING RAPIDLY...WE FELT IT WOULD BE PRUDENT TO GO AGAINST MOST GUIDANCE AND ISSUE A WINTER STORM WARNING FOR OUT SOUTHERN ZONES DUE TO THE COMBINATION THREAT OF SNOW AND ICE. TEMPS REMAIN IN THE 20S AT NEWPORT...SO A SIMILAR SITUATION FOR THEM...AS LONG AS GRADIENTS REMAIN OFFSHORE IT IS GOING TO BE DIFFICULT TO GIVE THEM THE ALL CLEAR. AREAS FARTHER NORTH ALONG THE COAST...TILLAMOOK AND LINCOLN CITY...WILL STAY SNOW LONGER THAN AREAS FARTHER SOUTH. FARTHER NORTH IT IS PERHAPS A BIT EASIER. THERE IS STILL PLENTY OF COLD AIR IN THE COLUMBIA BASIN...AND ALTHOUGH EASTERLY GRADIENTS HAVE RELAXED THROUGH THE GORGE...THEY WILL RAMP UP AGAIN AS LOW PRESSURE APPROACHES THIS AFTERNOON AND EVENING. THIS WILL KEEP THE PROVERBIAL FREEZER DOOR OPEN...REPLENESHING THE NORTHERN HALF OF THE WILLAMETTE VALLEY WITH COLD AIR. THE EASTSIDE COLD POOL IS DEEP...PROBABLY ABOUT 4000-6000FT DEEP...SO ANY WARM NOSE TRYING TO PUSH NORTHEAST INTO PORTLAND WILL HAVE A VERY DIFFICULT TIME PUSHING ANY TEMPERATURES IN THE COLUMN ABOVE FREEZING. IN FACT...MILDER PACIFIC AIR PUSHING INTO THE PORTLAND METRO WILL LIKELY ENHANCE LOW-MID LEVEL FRONTOGENESIS AS A SQUEEZE PLAY OCCURS BETWEEN MOIST AND MILD PACIFIC AIR AND THE ARCTIC AIR THAT IS IN PLACE. THIS WILL CREATE LIFT AND ENHANCE PRECIPITATION...THE 00Z/06Z GFS SHOW THIS PRETTY WELL...WHICH THEY DID WITH YESTERDAYS SYSTEM. A LOT OF WORDS TO SIMPLY SAY...EXPECT A SIMILAR SCENARIO TO PLAY OUT TODAY TO THE ONE THAT PLAYED OUT THURSDAY. OVERALL TIMING WILL BE A FEW HOURS LATER...AND THE TIMING OF THE WARNINGS REFLECT THIS. AS MENTIONED EARLIER...THE MAIN DIFFERENCE WILL BE THE WARMER AIR HAVING A LITTLE MORE SUCCESS MOVING INTO THE SOUTH WILLAMETTE VALLEY AS THE SFC LOW MOVES ONSHORE. ANOTHER SIMILAR WAVE IS ON TAP FOR LATER SATURDAY AND SUNDAY... THOUGH WITH FAST FLOW AND SUBTLE SHORTWAVES IN THE NE PACIFIC CONFIDENCE IN PRECISE TIMING IS LOW. 06Z GFS/NAM PAINT A SIMILAR STRIPE OF QPF ACROSS THE WILLAMETTE VALLEY WITH THIS SYSTEM. THE MOUNTAINS ARE NOT TO BE FORGOTTEN...OVERALL THE NEXT FEW DAYS THE CASCADES WILL SEE A MUCH-NEEDED BOOST TO THEIR SNOWPACK. THE UW WRF-GFS...NAM...GEM...GFS...ALL HAVE SNOW MEASURED IN FEET FOR THEM OVER THE COMING DAYS. AFTER A LONG WAIT...IT APPEARS THE HOPES FOR SNOW IN THE CASCADES ARE FINALLY COMING TO FRUITION. WEAGLE .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...REGION BEGINS TO SIT SQUARE UNDER THE STORM TRACK FOR THE WEEK AHEAD. BROAD LOW PRESSURE WILL SET UP OVER THE GULF OF ALASKA WITH A BROAD RIDGE CENTERED JUST OFF THE BAJA CALIFORNIA COAST. THIS WILL ALLOW A SERIES OF SHORT WAVES TO PROGRESS ALONG JET STREAM AND BRING MORE FREQUENT PERIODS OF RAIN AND MOUNTAIN SNOW AND FEWER PERIOD OF DRY PERIODS. GENERALLY SPEAKING...WILL SEE SNOW LEVELS FLUCTUATE BETWEEN 3000 FEET AND 5500 FEET DEPENDING ON WHEN THE PASSING SHORT WAVES PUSH LEADING WARMER AIR SLIGHTLY FURTHER NORTH. OVERALL...THIS APPEARS TO BE A GOOD PATTERN FOR PRODUCING SNOW PACKS HIGHER IN THE CASCADES AS OVERNIGHT TEMPERATURES WILL LARGELY STAY BELOW FREEZING. MODELS ARE IN DECENT AGREEMENT WITH OVERALL TIMING OF INDIVIDUAL WAVES. PRECIP NOW APPEARS TO BE FOCUSED ON LATE SUNDAY NIGHT/MONDAY...MID-DAY TUESDAY/ TUESDAY EVENING...AND THEN THURSDAY HEADING INTO THURSDAY NIGHT. MODELED QPF AMOUNTS VARY...NOT SURPRISINGLY...BETWEEN THE MEDIUM RANGE MODELS AND THE INDIVIDUAL WAVES...BUT IT DOES APPEAR THE PACNW WILL BE IN THE CROSS HAIRS OF THE PACIFIC MOISTURE FEED. THUS DO NOT FEEL OVERLY COMFORTABLE REGARDING THE NATURE OF ANY ONE SPECIFIC SYSTEM. FORTUNATELY...THERE DO APPEAR TO BE AROUND 12 HOUR BREAKS BETWEEN SYSTEMS. /JBONK && .AVIATION...NEXT ROUND OF SNOW HAS PROGRESSED INLAND ABOUT TO REACH AS FAR NORTH AS KSLE. WILL CONTINUE TO SEE THIS BAND DRIFT NORTH REACHING KHIO...KPDX...AND KTTD BY 20Z IF NOT A BIT SOONER AND KAST AN HOUR OR SO LATER. THIS IS ALL FASTER THAN MODELS HAVE INDICATED AND HAVE ADAPTED TAFS TO MATCH. MAIN CHALLENGE WILL BE THE PROBABLE TRANSITION TO FREEZING RAIN AND OR SLEET ACROSS THE CENTRAL AND SOUTH VALLEY THIS AFTERNOON AND EVENING. HAVE ALREADY SEEN THE TRANSITION AT KONP. MODERATE SNOW AT KEUG WILL BEGIN TO GIVE WAY WITH THE BEST GUESS OCCURRING AT 22Z AND AT KSLE AT 23Z. EXPECT TO SEE A TENTH OR TWO OF ICE ACCUMULATION ON TOP OF THE ONGOING SNOW. DEEPER EAST WINDS ACROSS THE NORTH CASCADES SHOULD LIMIT THE NORTHWARD PROGRESSION OF THE FREEZING RAIN DURING NEXT 24 HOURS. FIRST GUESS TODAY MAY SEE KHIO KTTD AND KPDX CHANGE TO FZRA AROUND 09/03 Z SATURDAY EVENING BUT IT APPEARS THE BULK OF PRECIP SHOULD END BY THEN. HOWEVER...ACCUMULATING ICE IS STILL LIKELY. KPDX AND APPROACHES...LIGHT SNOW SHOWERS WILL REACH THE FIELD AROUND 20Z AS TODAY`S PRECIP BAND DRIFTS NORTHWARD. PEAK SNOW WILL INTENSIFY BEGINNING CLOSER TO 00Z WITH PERIODS OF HEAVY ACCUMULATION EXPECTED 08/00 TO 08/03Z. ALSO EXPECT BLSN TO OBSCURE NEAR SURFACE VSBY AT THAT TIME. CONTINUE TO EXPECT AROUND 3 INCHES OF TOTAL ACCUMULATION BY LATER EVENING. LOOKS LIKE SNOW WILL EVENTUALLY BECOME MORE SHOWERY. CURRENT THOUGHTS BRING FIRST FZRA POSSIBILITY TO KPDX AROUND 09/03Z. && .MARINE...BROAD AREA OF LOW PRES OVER NE PAC...WITH HIGH PRES WILL INLAND. GRADIENTS WILL GRADUALLY INCREASE AGAIN TODAY AND TONIGHT AS STRONGER LOW APPROACHES FROM THE SW. WINDS ARE GUSTING 20 TO 25 KT OVER THE N WATERS AT BUOY 29 AND WILL APPEAR TO CONTINUE THROUGH MOST OF TONIGHT. HAVE ISSUED A SMALL CRAFT ADVISORY TO COVER. NEAR SHORE WINDS ARE NOT SUPPORTING AN ADVISORY AT THIS TIME WITH COLDER DENSER AIR KEEPING THE WINDS OFF THE COAST RANGE ELEVATED UNTIL FURTHER OUT TO SEA. ADDITIONALLY...FREEZING RAIN IS OCCURRING NEAR NEWPORT AND WILL PROGRESS NORTHWARD UP THE COAST TODAY...PERHAPS REACHING AS FAR AS KAST BUT MORE LIKELY SEASIDE AND SOUTH. COULD PICK UP A TENTH OR TWO OF ICE ACCUMULATION. SEAS HOLDING AT 4 TO 5 FT. A STRONGER STORM SYSTEM WILL BRING SOLID GALE FORCE WINDS OF 25 TO 40 KT TUES...WITH SEAS BUILDING ABOVE 10 FT. /JBONK && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR NORTHERN OREGON CASCADES-UPPER HOOD RIVER VALLEY. WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO 10 AM PST SATURDAY FOR CENTRAL COLUMBIA RIVER GORGE-GREATER PORTLAND METRO AREA-WESTERN COLUMBIA RIVER GORGE. WINTER STORM WARNING UNTIL 6 AM PST SATURDAY FOR CENTRAL WILLAMETTE VALLEY-COAST RANGE OF NORTHWEST OREGON-NORTHERN OREGON CASCADE FOOTHILLS. WINTER STORM WARNING UNTIL 6 PM PST SATURDAY FOR CASCADE FOOTHILLS IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN OREGON-SOUTH WILLAMETTE VALLEY. WINTER WEATHER ADVISORY UNTIL 6 PM PST SATURDAY FOR CASCADES IN LANE COUNTY. WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM PST SATURDAY FOR LOWER COLUMBIA. WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL OREGON COAST. WINTER STORM WARNING UNTIL 10 AM PST SATURDAY FOR NORTH OREGON COAST. WA...WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO 10 AM PST SATURDAY FOR CENTRAL COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-WESTERN COLUMBIA RIVER GORGE. WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM PST SATURDAY FOR I-5 CORRIDOR IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST SATURDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. && $$ MORE WEATHER INFORMATION ONLINE AT.. HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV 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 PORTLAND OR
1010 AM PST FRI FEB 7 2014 .SYNOPSIS...THE SECOND SYSTEM IN A ONE-TWO-THREE PUNCH OF WINTRY WEATHER FOR NORTHWEST OREGON IS DEVELOPING OFFSHORE...AND WILL SPREAD SNOW NORTHEAST ACROSS THE FORECAST AREA TODAY. SEVERAL INCHES OF SNOW ARE LIKELY FOR MOST OF OUR NORTHWEST OREGON ZONES BY SATURDAY MORNING...EVENTUALLY CHANGING TO SLEET AND FREEZING RAIN FROM THE SOUTH. SOUTHWEST WASHINGTON WILL BE ON THE NORTHERN FRINGE OF THE HEAVIER PRECIPITATION...WITH MAINLY AREAS NEAR THE COLUMBIA RIVER AFFECTED. THE THIRD SYSTEM WILL BRING MORE WINTRY WEATHER TO OUR AREA LATER SATURDAY INTO SUNDAY...BUT THERE IS STILL A BIT OF UNCERTAINTY IN HOW FAR NORTH THIS SYSTEMS IMPACTS WILL REACH. OVERALL A VERY COMPLEX WINTER WEATHER SITUATION UNFOLDING OVER SOUTHWEST WASHINGTON AND NORTHWEST OREGON THROUGH SUNDAY. NEXT WEEK THERE WILL BE A TURN TOWARD MORE TYPICAL WEATHER FOR THE REGION WITH MILDER PACIFIC FRONTAL SYSTEMS BRINGING PERIODS OF RAIN. && .UPDATE...SNOW IS PROGRESING UP THE VALLEY...AND SPED UP THE POPS THIS AFTERNOON. THUS EXPECT SNOW TO BEGIN SOONER THAN EARLIER FORECAST. ALSO...CAMERAS IN NEWPORT SHOW LIQUID PRECIP AND TEMPS ARE AROUND 30.EXPECT SOME FREEZING RAIN IN THESE AREAS...AND UP TO A TENTH INCH HAS BEEN REPORTED IN SILETZ. FARTHER INLAND STILL THINK SNOW WILL BE THE DOMINANT PRECIP TYPE AS THE RAWS STATIONS ARE UNCHANGED FROM EARLIER. THAT SAID THE RAP 925 TEMPERATURE IS TRACKING FAIRLY WELL IF NOT A LITTLE SNOW FOR THE WARM NOSE. IF THE RAP IS TRUE...THIS WOULD SUGGEST A TRANSITION TO FREEZING RAIN OR SLEET THIS AFTERNOON. WILL CONTINUING HEDGING THE FORECAST IN THIS DIRECTION. THE SOUTH CENTRAL COAST NEAR FLORENCE SHOULD BE JUST RAIN BASED ON OBS AND CAMERAS. NOWCAST COMING OUT SOON. /KMD REST OF THE MORNING UPDATE UNCHAGED...NO BIG CHANGES FOR THE MORNING UPDATE. SNOW HAS STARTED TO FALL IN EUGENE BASED ON REPORTS WITH A FRESH COATING EARLIER AND NOW COMING DOWN HARDER. EXPECT THIS IS LOW LEVEL FORCED AS THE UPPER FORCING IS STILL A BIT FARTHER OFFSHORE. WHILE SNOW IS THE INITIAL PRECIPITATION TYPE AND SHOULD BE FOR A WHILE IN THE SOUTH... AS MODELS SUGGEST THE WARM NOSE AT 925/850 STAYS SOUTH THROUGH 0Z. SO INITIAL CONCERNS FOR FREEZING RAIN ARE TOO HIGH JUST YET. THAT SAID... CONCERNS ARE SOMEWHAT HIGHER FOR FREEZING RAIN/ICING SITUATION AT LEAST FOR PARTS OF THE CENTRAL OREGON COAST...COAST RANGE...SOUTH WILLAMETTE VALLEY...AND THE LOWER VALLEYS IN THE LANE COUNTY CASCADES LATER THIS AFTERNOON. OBSERVATIONS THIS MORNING SHOW A THICK DIVIDING LINE BETWEEN WARMER SURFACE AIR AT THE COAST WHERE IT IS IN THE LOW TO MID 30S AT WALDPORT...YACHATS AND FLORENCE...MEANWHILE OFFSHORE FLOW MAINTAINS COLDER AIR FROM NEWPORT NORTH. A SIMILIAR STORY IS THE CASE WHERE IT IS 40 AND RAINING IN ROSEBURG AND 21 IN EUGENE. MEANWHILE...A TELLING TALE OF WHAT TO MONITOR TODAY MAY BE THE RAWS STATIONS IN THE CENTRAL OREGON COAST RANGE. HIGH POINT AND GOODWIN PEAK ARE GOOD ONES AT JUST UNDER 2000 FT...AND ARE LOCATED AT TO THE SOUTHWEST OF EUGENE. THESE STATIONS SIT AT AROUND 32 DEGREES WITH SIMILAR DEWPOINT VALUES AND MAINTAIN A WEAK OR A SOUTH WIND. NOW THESE STATIONS WERE A LITTLE WARMER LAST EVENING WHEN FREEZING RAIN MIXED IN. MEANWHILE VILLAGE CREEK AND WILKINSON RIDGE RAWS JUST A BIT FARTHER NORTH IN THE COAST RANGE...WHICH ARE LOCATED BETWEEN EUGENE AND CORVALLIS AND AT 1500 FT ELEVATION...SIT AT 25 AND 26. THIS IS POTENTIALLY THE HIGHEST IMPACT WEATHER...EVEN THOUGH ANOTHER ROUND OF WIDESPREAD SNOW IS AGAIN EXPECTED ACROSS THE AREA. THIS IS SOMEWHAT OF A UNIQUE SITUATION IN THAT IT IS NOT COMMON FOR OUR AREA TO GO FROM SNOW TO FREEZING RAIN AND BACK TO SNOW...THUS THE CONCERN...BUT THERE IS ALWAYS A FIRST FOR EVERYTHING. THE MODELS ARE ALREADY BRINING THE LOWEST LEVEL COLD AIR TOO FAST...BUT AS THE SURFACE LOW TRACKS IN IT LOOKS LIKE THE COAST WILL SEE A PERIOD OF FREEZING RAIN AND THEN IF THE LOW GOES. SOMETHING WE HAVEN`T SEEN MUCH OF...BUT THERE ARE A FEW LIGHTNING STRIKES WELL OFFSHORE OF THE MOUTH OF THE COLUMBIA RIVER NEAR THE MID LEVEL DRY SLOT AND WHERE THE CURRENT DOMINATING SURFACE LOW IS. MODELS ARE IN FAIR AGREEMENT THAT THE JET ENERGY TO THE SOUTH WILL ALLOW THE LOW MUCH FARTHER OFFSHORE AND TO THE SOUTH TO DOMINATE. WHERE THEY DIFFER IS HOW FAR NORTH THE LOW LEVEL WARM AIR SPREADS. THIS MAKES THE DIFFERENCE BETWEEN A BUNCH OF ICE FROM NEWPORT NORTH WITH THE SECOND PUNCH COMING IN LATER TODAY AND TONIGHT. MODELS DO GENERALLY AGREE THAT AT LEAST THROUGH 12Z SATURDAY THAT THE FREEZING RAIN THREAT IN THE VALLEY REMAINS FROM SALEM SOUTH. IF YOU BELIEVE NATIONAL GUIDANCE AND THE RAW MOS GUIDANCE...EUGENE WILL SWITCH TO RAIN. DONT THINK THAT WILL HAPPEN. MODELS DO GENERALLY AGREE THAT AT LEAST THROUGH 12Z SATURDAY THAT THE FREEZING RAIN THREAT IN THE VALLEY REMAINS FROM SALEM SOUTH. THAT IS NOT A GUARANTEE AS GFS/NAM BUFR SOUNDINGS BRING THE WARM NOSE AWFULLY CLOSE...BUT THE CURRENT FEELING RIGHT NOW. WILL KEEP A CHANCE THERE LATE TONIGHT INTO EARLY SATURDAY AS GFS/NAM BUFR SOUNDINGS BRING THE WARM NOSE AWFULLY CLOSE. NOT TO IGNORE AREAS FARTHER NORTH...PROFILES ARE ALL SNOW,. THERE IS PLENTY OF LOW LEVEL FRONTOGENETICAL FORCING WHICH IS MORE LOOSELY ORGANIZED OFFSHORE BUT WILL PICK UP THIS AFTERNOON OVER THE AREA AS THE CLASH OF THE COLD AND MILD PACIFIC AIR COMMENCES AGAIN FARTHER NORTH. THIS WILL ALLOW PRECIPITATION IN THE FORM OF SNOW TO GET GOING THIS AFTERNOON AND EVENING AND AGAIN EXPECT BANDING TO OCCUR...LIKELY FARTHER NORTH THAN THE MODELS ARE SHOWING. AVIATION AND MARINE DISCUSSION TO BE UPDATED WITH THE TAF PACKAGE. /KMD && .SHORT TERM...AGAIN OUR APOLOGIES FOR THE TARDINESS OF THIS DISCUSSION... THIS SHIFT HAS BEEN VERY BUSY ON MANY FRONTS...BOTH LITERALLY AND FIGURATIVELY. FIRST THINGS FIRST...AS MOST OF US KNOW BY NOW WEAK LOW PRESSURE BROUGHT SIGNIFICANT SNOWFALL FOR JUST ABOUT THE ENTIRE FORECAST AREA...WITH AS MUCH AS A FOOT OF SNOW IN SOUTHERN PORTIONS OF THE WILLAMETTE VALLEY AND CLOSE TO THAT IN THE COAST RANGE. LOW PRESSURE TOOK THE PERFECT TRACK NORTHEAST INTO THE FORECAST AREA...WITH ITS ASSOCIATED FRONT OF MOIST AND RELATIVELY MILD PACIFIC AIR OCCLUDING AS IT MOVED INTO A BURLY ARCTIC AIR MASS ENTRENCHED OVER THE PACIFIC NORTHWEST. ALL WARNINGS AND ADVISORIES FOR THIS SYSTEM HAVE ENDED IN OUR FORECAST AREA...AS THIS SYSTEM HAS SINCE SHIFTED ITS FOCUS EAST INTO THE COLUMBIA BASIN AND SPOKANE AREA. THE REASON FOR THE RECAP IS THAT THIS IS ALMOST EXACTLY WHAT WILL HAPPEN AGAIN LATER TODAY INTO TONIGHT. BROAD AND ELONGATED UPPER LEVEL LOW PRESSURE EXTENDS FROM VANCOUVER ISLAND WESTWARD INTO THE PACIFIC. A VORT LOBE IS POSITIONED NEAR 47N/133W...ALMOST EXACTLY WHERE THURSDAYS VORT LOBE WAS POSITIONED THIS TIME YESTERDAY. MSAS ANALYSIS AND IR IMAGERY INDICATE A SURFACE REFLECTION VERY NEARBY AT ABOUT 45N/132W. ONE DIFFERENCE IS THAT THIS SYSTEM IS BEGINNING TO TAP INTO DEEPER MOISTURE...WITH A NARROW PLUME EXTENDING SOUTHWEST ALL THE WAY TO HAWAII. AS A RESULT MODELS ARE SHOWING MORE IMPRESSIVE QPF WITH THIS SYSTEM...AS WELL AS A STRONGER SURGE OF WARM AIR ALOFT WHICH SHOULD EVENTUALLY CHANGE SNOW TO SLEET AND FREEZING RAIN IN THE EUGENE AREA AND POSSIBLY FARTHER NORTH LATER TODAY AND TONIGHT. OVERRUNNING PRECIPITATION IS ALREADY BEGINNING TO SPREAD INTO FAR SW OREGON... THIS WILL CONTINUE NORTHEASTWARD THROUGHOUT THE DAY AS THE VORT LOBE TEAMS UP WITH THIS WILL BE A COMPLEX PRECIPITATION TYPE FORECAST...WITH COLD AIR TRAPPED IN THE WILLAMETTE VALLEY. TO SHOW THE CONTRAST...AT 5 AM THE TEMPERATURE WAS 21 DEGREES IN EUGENE AND 40 DEGREES IN ROSEBURG. PRESSURE GRADIENTS REMAIN NORTHERLY THROUGH THE WILLAMETTE VALLEY... SO THIS LOW LEVEL COLD AIR IS NOT GOING ANYWHERE SOON. USING 4KM UW WRFGFS SOUNDINGS ALONE...IT WOULD SEEM ENOUGH WARM AIR WOULD ADVECT INTO EUGENE TO PUSH THEIR TEMPS WELL INTO THE 30S AND CHANGE PRECIPITATION TO RAIN. NAM BUFR SOUNDINGS SHOW AN EVEN MORE DRAMATIC WARMUP. HOWEVER...AS LONG AS PRESSURE GRADIENTS THROUGH THE WILLAMETTE VALLEY REMAIN NORTHERLY...THERE WILL WILL CONTINUE TO BE A THREAT OF FROZEN/FREEZING PRECIPITATION. WITH QPF INCREASING RAPIDLY...WE FELT IT WOULD BE PRUDENT TO GO AGAINST MOST GUIDANCE AND ISSUE A WINTER STORM WARNING FOR OUT SOUTHERN ZONES DUE TO THE COMBINATION THREAT OF SNOW AND ICE. TEMPS REMAIN IN THE 20S AT NEWPORT...SO A SIMILAR SITUATION FOR THEM...AS LONG AS GRADIENTS REMAIN OFFSHORE IT IS GOING TO BE DIFFICULT TO GIVE THEM THE ALL CLEAR. AREAS FARTHER NORTH ALONG THE COAST...TILLAMOOK AND LINCOLN CITY...WILL STAY SNOW LONGER THAN AREAS FARTHER SOUTH. FARTHER NORTH IT IS PERHAPS A BIT EASIER. THERE IS STILL PLENTY OF COLD AIR IN THE COLUMBIA BASIN...AND ALTHOUGH EASTERLY GRADIENTS HAVE RELAXED THROUGH THE GORGE...THEY WILL RAMP UP AGAIN AS LOW PRESSURE APPROACHES THIS AFTERNOON AND EVENING. THIS WILL KEEP THE PROVERBIAL FREEZER DOOR OPEN...REPLENESHING THE NORTHERN HALF OF THE WILLAMETTE VALLEY WITH COLD AIR. THE EASTSIDE COLD POOL IS DEEP...PROBABLY ABOUT 4000-6000FT DEEP...SO ANY WARM NOSE TRYING TO PUSH NORTHEAST INTO PORTLAND WILL HAVE A VERY DIFFICULT TIME PUSHING ANY TEMPERATURES IN THE COLUMN ABOVE FREEZING. IN FACT...MILDER PACIFIC AIR PUSHING INTO THE PORTLAND METRO WILL LIKELY ENHANCE LOW-MID LEVEL FRONTOGENESIS AS A SQUEEZE PLAY OCCURS BETWEEN MOIST AND MILD PACIFIC AIR AND THE ARCTIC AIR THAT IS IN PLACE. THIS WILL CREATE LIFT AND ENHANCE PRECIPITATION...THE 00Z/06Z GFS SHOW THIS PRETTY WELL...WHICH THEY DID WITH YESTERDAYS SYSTEM. A LOT OF WORDS TO SIMPLY SAY...EXPECT A SIMILAR SCENARIO TO PLAY OUT TODAY TO THE ONE THAT PLAYED OUT THURSDAY. OVERALL TIMING WILL BE A FEW HOURS LATER...AND THE TIMING OF THE WARNINGS REFLECT THIS. AS MENTIONED EARLIER...THE MAIN DIFFERENCE WILL BE THE WARMER AIR HAVING A LITTLE MORE SUCCESS MOVING INTO THE SOUTH WILLAMETTE VALLEY AS THE SFC LOW MOVES ONSHORE. ANOTHER SIMILAR WAVE IS ON TAP FOR LATER SATURDAY AND SUNDAY... THOUGH WITH FAST FLOW AND SUBTLE SHORTWAVES IN THE NE PACIFIC CONFIDENCE IN PRECISE TIMING IS LOW. 06Z GFS/NAM PAINT A SIMILAR STRIPE OF QPF ACROSS THE WILLAMETTE VALLEY WITH THIS SYSTEM. THE MOUNTAINS ARE NOT TO BE FORGOTTEN...OVERALL THE NEXT FEW DAYS THE CASCADES WILL SEE A MUCH-NEEDED BOOST TO THEIR SNOWPACK. THE UW WRF-GFS...NAM...GEM...GFS...ALL HAVE SNOW MEASURED IN FEET FOR THEM OVER THE COMING DAYS. AFTER A LONG WAIT...IT APPEARS THE HOPES FOR SNOW IN THE CASCADES ARE FINALLY COMING TO FRUITION. WEAGLE .LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...REGION BEGINS TO SIT SQUARE UNDER THE STORM TRACK FOR THE WEEK AHEAD. BROAD LOW PRESSURE WILL SET UP OVER THE GULF OF ALASKA WITH A BROAD RIDGE CENTERED JUST OFF THE BAJA CALIFORNIA COAST. THIS WILL ALLOW A SERIES OF SHORT WAVES TO PROGRESS ALONG JET STREAM AND BRING MORE FREQUENT PERIODS OF RAIN AND MOUNTAIN SNOW AND FEWER PERIOD OF DRY PERIODS. GENERALLY SPEAKING...WILL SEE SNOW LEVELS FLUCTUATE BETWEEN 3000 FEET AND 5500 FEET DEPENDING ON WHEN THE PASSING SHORT WAVES PUSH LEADING WARMER AIR SLIGHTLY FURTHER NORTH. OVERALL...THIS APPEARS TO BE A GOOD PATTERN FOR PRODUCING SNOW PACKS HIGHER IN THE CASCADES AS OVERNIGHT TEMPERATURES WILL LARGELY STAY BELOW FREEZING. MODELS ARE IN DECENT AGREEMENT WITH OVERALL TIMING OF INDIVIDUAL WAVES. PRECIP NOW APPEARS TO BE FOCUSED ON LATE SUNDAY NIGHT/MONDAY...MID-DAY TUESDAY/ TUESDAY EVENING...AND THEN THURSDAY HEADING INTO THURSDAY NIGHT. MODELED QPF AMOUNTS VARY...NOT SURPRISINGLY...BETWEEN THE MEDIUM RANGE MODELS AND THE INDIVIDUAL WAVES...BUT IT DOES APPEAR THE PACNW WILL BE IN THE CROSS HAIRS OF THE PACIFIC MOISTURE FEED. THUS DO NOT FEEL OVERLY COMFORTABLE REGARDING THE NATURE OF ANY ONE SPECIFIC SYSTEM. FORTUNATELY...THERE DO APPEAR TO BE AROUND 12 HOUR BREAKS BETWEEN SYSTEMS. /JBONK && .AVIATION...WIDE RANGE OF CONDITIONS...WITH IFR AND MVFR OVER THE INTERIOR...AND MOSTLY VFR WITH POCKETS OF MVFR ALONG THE COAST. NOT MUCH CHANGE THIS AM...THOUGH INTERIOR CONDITIONS WILL IMPROVE TO MIX OF MVFR AND LOW VFR THIS AM. HOWEVER...SNOW WILL INCREASE ACROSS THE REGION AGAIN AFTER 18Z OVER LANE COUNTY...AND SPREAD N. EXPECT CONDITIONS TO DROP BACK INTO IFR AFTER 20Z...WITH MTNS AND HIGHER TERRAIN OBSCURED. SNOW MAY TRANSITION TO A MIX OF SNOW... SLEET...AND POSSIBLY FREEZING RAIN S OF A KONP TO KEUG LINE AGAIN LATE THIS AFTERNOON INTO THE EVENING. KPDX AND APPROACHES...FEW FLURRIES AROUND THIS AM...BUT OVERALL DRY WITH LOW VFR CONDITIONS. WILL HAVE OCCASIONAL MVFR CIGS UNTIL 12Z OR 13Z. BY AFTERNOON...LIGHT SNOW WILL PUSH INTO OPS AREA FROM THE S AND SW. LIKELY TO SEE SIMILAR CONDITIONS TO THOSE ON THU AFTERNOON...WITH IFR AFT 21Z AND PERSISTING TO 08Z. LIKELY 2 TO 4 INCHES OF NEW SNOW AT AIRPORT DURING THAT TIME. ROCKEY. && .MARINE...BROAD AREA OF LOW PRES OVER NE PAC...WITH HIGH PRES WILL INLAND. GRADIENTS WILL GRADUALLY INCREASE AGAIN TODAY AND TONIGHT AS STRONGER LOW APPROACHES FROM THE SW. WINDS MAY GUST AGAIN AT 20 TO 25 KT OVER THE N WATERS NEAR SHORE LATE TODAY THROUGH SAT...BUT FEEL MAY NOT QUITE REACH THAT. SO WILL OPT GO WITH NO ADVISORIES AT THIS TIME. SEAS HOLDING AT 4 TO 5 FT. A STRONGER STORM SYSTEM WILL BRING SOLID GALE FORCE WINDS OF 25 TO 40 KT TUES...WITH SEAS BUILDING ABOVE 10 FT. ROCKEY. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY FROM NOON TODAY TO 10 AM SAT FOR... NORTHERN OREGON CASCADES UPPER HOOD RIVER VALLEY. WINTER WEATHER ADVISORY FROM 10 AM TODAY TO 6 PM SAT FOR... CASCADES IN LANE COUNTY. WINTER WEATHER ADVISORY FROM 4 PM TODAY TO 10 AM SAT FOR... LOWER COLUMBIA. WINTER STORM WARNING FROM 10 AM TODAY TO 6 PM SAT FOR... CASCADE FOOTHILLS IN LANE COUNTY CENTRAL COAST RANGE OF WESTERN OREGON SOUTH WILLAMETTE VALLEY INCLUDING EUGENE. WINTER STORM WARNING FROM 10 AM TO 10 PM TODAY FOR... CENTRAL OREGON COAST...INCLUDING NEWPORT. WINTER STORM WARNING FROM NOON TO 10 AM SAT FOR... NORTH OREGON COAST. WINTER STORM WARNING FROM NOON TODAY TO 6 AM SAT FOR... CENTRAL WILLAMETTE VALLEY INCLUDING SALEM COAST RANGE OF NORTHWEST OREGON NORTHERN OREGON CASCADE FOOTHILLS. WINTER STORM WARNING FROM 2 PM TODAY TO 10 AM SAT FOR... CENTRAL COLUMBIA RIVER GORGE WESTERN COLUMBIA RIVER GORGE NORTH WILLAMETTE VALLEY INCLUDING PORTLAND METRO AREA. WA...WINTER STORM WARNING FROM 2 PM TODAY TO 10 AM SAT FOR... CENTRAL COLUMBIA RIVER GORGE WESTERN COLUMBIA RIVER GORGE CLARK COUNTY INCLUDING GREATER VANCOUVER AREA WINTER WEATHER ADVISORY FROM 4 PM TODAY TO 10 AM SAT FOR... I-5 CORRIDOR IN COWLITZ COUNTY INCLUDING KELSO SOUTH WASHINGTON CASCADE FOOTHILLS. PZ...NONE. && $$ MORE WEATHER INFORMATION ONLINE AT.. HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV 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...UPDATED
NWS AMARILLO TX
742 PM CST SAT FEB 8 2014 .UPDATE... ONCE AGAIN THIS EVENING...THE LATEST RUN OF THE HRRR SHOWING LOW VISIBILITIES AND CEILINGS DEVELOPING OR SPREADING WEST FROM OFF THE CAPROCK TO NEAR A TEXAS COUNTY OKLAHOMA TO CLARENDON TEXAS LINE. WILL CONTINUE TO MONITOR DEVELOPMENTS AS A FREEZING FOG ADVISORY MAY ONCE AGAIN BE NEEDED TONIGHT AND SUNDAY MORNING FOR PORTIONS OF THE EASTERN AND POSSIBLY CENTRAL SECTIONS OF THE PANHANDLES. ALSO...THE FREEZING FOG MAY SPREAD FURTHER WEST INTO THE AMARILLO AND CANYON AREAS AND ANOTHER UPDATE MAY BE NEEDED. OTHERWISE...WILL BRING THE WIDESPREAD FREEZING FOG AS FAR WEST...FOR THE MOMENT...TO A TEXAS COUNTY TO CLARENDON LINE AND WILL HOLD OFF FOR NOW ON A FREEZING FOG ADVISORY WITH THE STIPULATION THAT ONE MAY BE NEEDED LATER ON. ALL PUBLIC PRODUCTS HAVE BEEN UPDATED AND SENT. SCHNEIDER && .PREV DISCUSSION... /ISSUED 534 PM CST SAT FEB 8 2014/ AVIATION... 00Z TAF CYCLE NORTHWESTERLY UPPER FLOW ACROSS THE PANHANDLES AND UPPER TROUGH OVER THE ROCKIES WILL KEEP CONSIDERABLE HIGH LEVEL CLOUDINESS THROUGH 00Z MONDAY. LOW CLOUDINESS AND POSSIBLY SOME AREAS OF FREEZING FOG WILL SPREAD FROM NORTHEAST TO SOUTHWEST BEHIND A COLD FRONT TONIGHT AND SUNDAY. THIS FRONT WILL MOVE THROUGH THE GUYMON TAF SITE AROUND 08Z TO 11Z SUNDAY...ACROSS THE AMARILLO AND DALHART TAF SITES BETWEEN 12Z AND 15Z SUNDAY. LIGHT WINDS TONIGHT 5 TO 15 KNOTS WILL SHIFT TO THE NORTH AND NORTHEAST AFTER FRONTAL PASSAGE AND INCREASE TO AROUND 10 TO 20 KNOTS. VFR CONDITIONS EARLY WILL BECOME IFR TO MVFR BEHIND THE COLD FRONT AND DROPPING TO VLIFR TO LIFR AT THE GUYMON TAF SITE AFTER 12Z TO 14Z SUNDAY. SCHNEIDER PREV DISCUSSION... /ISSUED 246 PM CST SAT FEB 8 2014/ DISCUSSION... CURRENTLY 63 DEGREES AT THE NWS AMARILLO OFFICE...FIRST TIME AMARILLO HAS BEEN ABOVE 50 OR 60 DEGREES SINCE JANUARY 30. MOST OF THE AREA IS WARM EXCEPT FOR THE FAR EASTERN AND NORTHEASTERN PANHANDLES. THE WARMING IN THESE LOCATIONS IS BEING INHIBITED BY SNOW PACK...WILL ALSO HAVE TO WATCH THESE AREAS AS THEY HAVE THE BEST CHANCE FOR ANOTHER ROUND OF FREEZING FOG OVERNIGHT. WILL NOT ISSUE A FREEZING FOG ADVISORY AT THIS TIME SINCE LAST NIGHT LOCATIONS WITH A 6 DEGREE DEWPOINT DEPRESSION RECEIVED FOG BUT MOISTER AREAS DID NOT. MIGHT HAVE TO WAIT TILL WE SEE THE WHITES OF THE FREEZING FOGS EYES TO SEE WHERE PATCHY FOG MIGHT SET UP. COLD FRONT WILL PUSH SOUTH IN THE EARLY AM HOURS TOMORROW AND KNOCK BACK TEMPERATURES ACROSS THE AREA. SLIGHT CHANCE FOR LIGHT SNOW IN THE NORTHEAST PANHANDLES OVERNIGHT TOMORROW BUT MOST OF THE AREA WILL STAY DRY. MODELS ARE STILL COMING IN WITH THE SYSTEM MOVING FURTHER SOUTH AND KEEPS MOST OF OUR AREA DRY. BEST CHANCE FOR PRECIP FOR THE NEXT 7 DAYS LOOKS TO BE IN THE SOUTHWEST MONDAY EVENING/NIGHT. IF SNOW DOES FALL IN OUR AREA IT LOOKS TO BE VERY LIGHT. REST OF THE WEEK LOOKS DRY AND WARM AS HIGH TEMPERATURES CLIMB INTO THE FIFTIES AND SIXTIES FOR THE SECOND HALF OF THE WEEK. FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH FRIDAY. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 11/08
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1135 AM CST FRI FEB 7 2014 .DISCUSSION... SEE THE 18Z AVIATION DISCUSSION BELOW. 40 && .AVIATION... AREA OF DRIZZLE AND LIGHT RAIN SHOULD PERSIST OVER SE TX THROUGH SUNSET AS THE SHORTWAVE TROUGH MOVES ACROSS THE STATE. RECENT TEMPERATURE AND DEWPOINT TRENDS INDICATE THAT THE THREAT FOR FREEZING DRIZZLE MAY LAST THROUGH 19Z AT KCLL. OTHERWISE...EXPECT VFR THIS AFTERNOON FROM THE BIG HOUSTON AIRPORTS NORTHWARD AND MVFR SOUTHWARD. IFR TO MVFR CONDITIONS TO DEVELOP THIS EVENING AND CONTINUE THROUGH 12Z SATURDAY OVER MOST OF THE INLAND AREAS. CEILINGS LOOK TO LIFT AT KCLL AND KUTS...AND POSSIBLY FURTHER TO THE SOUTH. IF SO...THERE IS A CHANCE FOR PATCHY FOG TO DEVELOP BETWEEN 09Z AND 15Z. THE LATEST NAM INDICATES THAT ANOTHER SHORTWAVE TROUGH WILL MOVE ACROSS THE STATE SATURDAY MORNING. BECAUSE OF THIS AND GIVEN THE DEEPER LAYER MOISTURE...EXPECT IFR TO MVFR CONDITIONS TO CONTINUE TOWARD THE COAST THROUGH 18Z. 40 && .PREV DISCUSSION... /ISSUED 1001 AM CST FRI FEB 7 2014/ DISCUSSION... THOUGH WARMING...TEMPERATURES ARE STILL AROUND FREEZING ACROSS THE ADVISORY AREA. THE LOWER LEVELS OF THE ATMOSPHERE CONTINUE TO SATURATE AND RADAR IS STARTING TO SHOW SOME RETURNS WHICH COULD EVENTUALLY MAKE IT TO THE SURFACE...MOST LIKELY AS DRIZZLE. ANY PRECIPITATION THAT REACHES THE GROUND...AGAIN MORE LIKELY IN THE FORM OF DRIZZLE...MAY FREEZE ON CONTACT. ACCUMULATIONS IF ANY WILL BE LIGHT BUT STILL HAVE THE POTENTIAL TO CAUSE SOME TRAVEL ISSUES. THREAT OF WET BULBING ALSO A CONCERN IN THE SHORT TERM WITH ANY PRECIP WHERE READINGS ARE CURRENTLY JUST ABOVE FREEZING. WENT AHEAD AND EXTENDED WW ADVSY UNTIL NOON WHICH MATCHES UP W/ NEIGHBORING OFFICES TOO. WE WILL CONTINUE TO MONITOR TEMPERATURE AND RADAR TRENDS AND POSSIBLY FURTHER EXTEND THIS ADVISORY IF NEEDED. OTHERWISE...TWEAKED 1ST PERIOD GRIDS TO ADJUST TEMPS TO MATCH CURRENT TRENDS. NAM12, TX TECH WRF & HRRR SUGGEST INCREASING LIGHT PRECIP COVERAGE 2-9 PM ACROSS THE REGION AS INFLUENCE OF SHORTWAVE BECOMES FELT AND LLVLS FURTHER SATURATE. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 36 32 63 43 66 / 40 20 10 10 10 HOUSTON (IAH) 40 34 63 47 68 / 40 40 10 10 10 GALVESTON (GLS) 42 40 60 53 65 / 30 40 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES: AUSTIN...BRAZOS...BURLESON...COLORADO...GRIMES... MADISON...WALKER...WASHINGTON. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 PM CST THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...47 AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1133 AM CST FRI FEB 7 2014 .AVIATION... KLBB AND KCDS SHOULD BOTH REMAIN IN THE VFR CATEGORY THROUGH THE PERIOD AS AN UPPER DISTURBANCE CONTINUES TO PUSH EAST ACROSS THE PERMIAN BASIN AND INTO CENTRAL TEXAS THIS AFTERNOON. SOUTHWEST WINDS OF 12 KNOTS OR GREATER WILL PREVAIL AT KLBB THIS AFTERNOON AS LOW CLOUDS BREAK UP FAIRLY QUICKLY...WHILE KCDS WILL SEE A LOW DECK HANG AROUND FOR MUCH OF OR ALL OF THE AFTERNOON WITH SOUTH WINDS BELOW 12 KNOTS. WINDS WILL BEGIN TO VEER WESTERLY TONIGHT WITH CLEARING SKIES AS A SURFACE LOW/TROUGH APPROACHES. && .PREV DISCUSSION... /ISSUED 1023 AM CST FRI FEB 7 2014/ UPDATE... REPORTS OF SLEET ACROSS THE SOUTHERN SOUTH PLAINS INTO THE ROLLING PLAINS IN ASSOCIATION WITH AN UPPER DISTURBANCE PUSHING INTO THE TRANS-PECOS/PERMIAN BASIN VIA WATER VAPOR IMAGERY. THIS SEEMS TO CORRELATE WELL WITH THE 12Z MAF RAOB SHOWING A DISTINCT WARM NOSE FILTERING IN ALOFT FROM THE SOUTHWEST ATOP A WELL BELOW FREEZING BOUNDARY LAYER. THEREFORE...STILL EXPECTING A SUBSTANTIAL WARMUP TODAY AS COMPARED TO THE PAST COUPLE OF DAYS...WITH TEMPERATURES CLIMBING INTO THE 40S ACROSS MUCH OF THE CAPROCK WITH MAINLY 30S EAST OF THE ESCARPMENT. PREV DISCUSSION... /ISSUED 409 AM CST FRI FEB 7 2014/ SHORT TERM... THE LAST IN A STRING OF MINOR TROUGHS WILL ENTER THE SOUTH PLAINS THIS MORNING AND SERVE TO ENHANCE THE COVERAGE OF FLURRIES AND SOME VERY LIGHT SNOW AT TIMES. REGIONAL OBSERVATIONS EARLY THIS A.M. INDICATED PERIODS OF UNMEASURABLE SNOW FROM AMARILLO SOUTH TO LUBBOCK. RECENT HRRR AND NAM APPEAR ON TRACK WITH AN AXIS OF SUSTAINED LIFT TAKING SHAPE FROM THE NRN PERMIAN BASIN INTO THE FAR SRN SOUTH PLAINS NEAR SUNRISE. THIS REGION IS ALREADY BENEFITING FROM PROLONGED /ALBEIT WEAK/ ASCENT IN THE ENTRANCE REGION OF A STOUT 120 KNOT UPPER JET. BUT WITH NO APPRECIABLE UPTICK IN MOISTURE AVAILABLE...ANYTHING MORE THAN A DUSTING APPEARS A BIT TOO HARD TO COME BY IN THIS SETUP. SO WE HAVE PULLED SLIGHT CHANCE POPS IN FAVOR OF FLURRIES BEFORE NIXING THIS MENTION ALTOGETHER BY THE AFTERNOON BEHIND THE EXITING TROUGH. WEST WINDS AND CLEARING SKIES FOLLOWING THE UPPER WAVE WILL TUG MILDER THICKNESSES ACROSS THE CAPROCK...BUT STUBBORN S-SE WINDS OFF THE CAPROCK AND A LINGERING SNOW PACK IN PLACES WILL KEEP HIGHS HERE ABOUT 15 DEGREES COOLER. EXPECT A BIT MORE UNIFORMITY TONIGHT WITH TEMPS AS WESTERLY WINDS OVERSPREAD THE ENTIRE CWA. LONG TERM... AS WE BEGIN THE LONG TERM PERIOD...THE UPPER FLOW PATTERN ACROSS THE CONUS WILL BE RELATIVELY ZONAL...WITH A BROAD MEAN TROUGH ACROSS THE EAST...RIDGE WEST...AND WNW FLOW ALOFT ACROSS THE PLAINS. TWO PRIMARY ITEMS OF INTEREST WILL BE THE TIMING AND MAGNITUDE OF ANOTHER COLD AIRMASS SOMETIME SUNDAY...FOLLOWED BY A PROGRESSIVE UPPER WAVE MONDAY/TUESDAY WHICH WILL BRING WITH IT ANOTHER CHANCE FOR WINTER WEATHER ACROSS WEST TEXAS. SATURDAY IS EXPECTED TO BE QUITE WARM ACROSS THE AREA...AS BREEZY WESTERLY/DOWNSLOPING WINDS WILL DEVELOP IN RESPONSE TO PRESSURE FALLS ACROSS THE HIGH PLAINS. OPTED TO MAINTAIN THE PREVIOUS FORECAST WITH MINIMAL CHANGES... WITH HIGHS REACHING THE LOW TO POSSIBLY MID 60S ON THE SOUTH PLAINS...TO THE LOW 50S ACROSS THE ROLLING PLAINS WHERE SNOW REMAINS ON THE GROUND. FROM HERE...THE BIG QUESTION MARK REMAINS THE TIMING OF AN APPROACHING ARCTIC COLD FRONT...WHICH MODEL GUIDANCE CONTINUES TO STRUGGLE WITH. OPTED TO SIDE WITH THE SLOWER GFS/ECMWF SOLUTIONS... AS DAYTIME FROPAS TEND TO BE SLOWED BY DEEP MIXING AHEAD OF THEM. SOUTH OF THE FRONT...CONTINUED DOWNSLOPING WESTERLIES WILL LIKELY KEEP TEMPERATURES WARM SUNDAY... WHILE PORTIONS OF THE NORTHERN ROLLING PLAINS BEHIND THE FRONT WILL LIKELY EXPERIENCE A SHARP COOLDOWN. IT SHOULD BE NOTED AS WELL THAT WHILE CRITICAL FIRE WEATHER IS NOT EXPECTED...BREEZY...WARM AND DRY CONDITIONS MAY SLIGHTLY ELEVATED FIRE WEATHER CONDITIONS ACROSS PORTIONS OF THE SOUTHERN SOUTH PLAINS SATURDAY AND SUNDAY. WHILE THE TIMING OF THE FROPA SUNDAY IS STILL IN QUESTION...THERE IS LITTLE DOUBT THAT MONDAY AND MOST LIKELY TUESDAY WILL FEATURE WELL BELOW NORMAL TEMPERATURES ACROSS THE BOARD. LATEST MODEL GUIDANCE CONTINUES TO STRUGGLE REGARDING THE TIMING OF YET ANOTHER PROGRESSIVE SHORTWAVE EMBEDDED WITHIN THE WNW FLOW ALOFT. THE GFS CURRENTLY DEPICTS A FASTER... MORE POSITIVELY TILTED...AND WEAKER WAVE THAN THE ECMWF...WITH A TIMING DIFFERENCE OF ALMOST A FULL 24 HOURS. OPTED TO CONTINUE WITH THE GFS DEPICTION... WITH ENHANCED POPS ACROSS OUR NORTHERN ZONES BEGINNING MONDAY EVENING. ALSO OPTED TO REMOVE MOST OF THE RAIN MENTION...AS LATEST FORECAST TEMPS DROP BELOW FREEZING PRIOR TO THE ONSET OF PRECIPITATION. STILL...UNCERTAINTY REMAINS HIGH WITH THIS SYSTEM... ESPECIALLY ACROSS OUR SOUTHERN ZONES. AS THIS UPPER WAVE DEPARTS... BROAD RIDGING WILL BUILD EASTWARD AND ALLOW A PLEASANT WARMING TREND TO CARRY US INTO THE END OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 27 59 29 59 24 / 0 0 0 0 10 TULIA 24 57 29 57 20 / 0 0 0 0 10 PLAINVIEW 24 59 30 60 21 / 0 0 0 0 10 LEVELLAND 27 62 31 62 25 / 0 0 0 0 10 LUBBOCK 26 60 30 60 24 / 0 0 0 0 10 DENVER CITY 28 66 32 66 26 / 0 0 0 0 10 BROWNFIELD 28 61 30 63 25 / 0 0 0 0 10 CHILDRESS 21 53 23 42 22 / 0 0 0 0 10 SPUR 21 51 24 55 23 / 0 0 0 0 10 ASPERMONT 25 59 30 55 26 / 0 0 0 0 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1023 AM CST FRI FEB 7 2014 .UPDATE... REPORTS OF SLEET ACROSS THE SOUTHERN SOUTH PLAINS INTO THE ROLLING PLAINS IN ASSOCIATION WITH AN UPPER DISTURBANCE PUSHING INTO THE TRANS-PECOS/PERMIAN BASIN VIA WATER VAPOR IMAGERY. THIS SEEMS TO CORRELATE WELL WITH THE 12Z MAF RAOB SHOWING A DISTINCT WARM NOSE FILTERING IN ALOFT FROM THE SOUTHWEST ATOP A WELL BELOW FREEZING BOUNDARY LAYER. THEREFORE...STILL EXPECTING A SUBSTANTIAL WARMUP TODAY AS COMPARED TO THE PAST COUPLE OF DAYS...WITH TEMPERATURES CLIMBING INTO THE 40S ACROSS MUCH OF THE CAPROCK WITH MAINLY 30S EAST OF THE ESCARPMENT. && .PREV DISCUSSION... /ISSUED 517 AM CST FRI FEB 7 2014/ AVIATION... IFR CIGS WITH OCCASIONAL -SN AT LBB THIS MORNING WILL GIVE WAY TO VFR CONDS AND BREEZY SW WINDS BY MIDDAY BEHIND AN UPPER TROUGH. AT MOST WE EXPECT ONLY A DUSTING OF SNOW...SO WILL FOREGO AN AIRPORT WX WARNING. VFR CONDS WILL BE DELAYED AT CDS UNTIL AT LEAST MID-AFTN...BUT THERE IS A SMALL CHANCE LOW CLOUDS MAY LINGER THRU THE EVENING UNTIL DRIER SWLY WINDS FINALLY EMERGE. PREV DISCUSSION... /ISSUED 409 AM CST FRI FEB 7 2014/ SHORT TERM... THE LAST IN A STRING OF MINOR TROUGHS WILL ENTER THE SOUTH PLAINS THIS MORNING AND SERVE TO ENHANCE THE COVERAGE OF FLURRIES AND SOME VERY LIGHT SNOW AT TIMES. REGIONAL OBSERVATIONS EARLY THIS A.M. INDICATED PERIODS OF UNMEASURABLE SNOW FROM AMARILLO SOUTH TO LUBBOCK. RECENT HRRR AND NAM APPEAR ON TRACK WITH AN AXIS OF SUSTAINED LIFT TAKING SHAPE FROM THE NRN PERMIAN BASIN INTO THE FAR SRN SOUTH PLAINS NEAR SUNRISE. THIS REGION IS ALREADY BENEFITING FROM PROLONGED /ALBEIT WEAK/ ASCENT IN THE ENTRANCE REGION OF A STOUT 120 KNOT UPPER JET. BUT WITH NO APPRECIABLE UPTICK IN MOISTURE AVAILABLE...ANYTHING MORE THAN A DUSTING APPEARS A BIT TOO HARD TO COME BY IN THIS SETUP. SO WE HAVE PULLED SLIGHT CHANCE POPS IN FAVOR OF FLURRIES BEFORE NIXING THIS MENTION ALTOGETHER BY THE AFTERNOON BEHIND THE EXITING TROUGH. WEST WINDS AND CLEARING SKIES FOLLOWING THE UPPER WAVE WILL TUG MILDER THICKNESSES ACROSS THE CAPROCK...BUT STUBBORN S-SE WINDS OFF THE CAPROCK AND A LINGERING SNOW PACK IN PLACES WILL KEEP HIGHS HERE ABOUT 15 DEGREES COOLER. EXPECT A BIT MORE UNIFORMITY TONIGHT WITH TEMPS AS WESTERLY WINDS OVERSPREAD THE ENTIRE CWA. LONG TERM... AS WE BEGIN THE LONG TERM PERIOD...THE UPPER FLOW PATTERN ACROSS THE CONUS WILL BE RELATIVELY ZONAL...WITH A BROAD MEAN TROUGH ACROSS THE EAST...RIDGE WEST...AND WNW FLOW ALOFT ACROSS THE PLAINS. TWO PRIMARY ITEMS OF INTEREST WILL BE THE TIMING AND MAGNITUDE OF ANOTHER COLD AIRMASS SOMETIME SUNDAY...FOLLOWED BY A PROGRESSIVE UPPER WAVE MONDAY/TUESDAY WHICH WILL BRING WITH IT ANOTHER CHANCE FOR WINTER WEATHER ACROSS WEST TEXAS. SATURDAY IS EXPECTED TO BE QUITE WARM ACROSS THE AREA...AS BREEZY WESTERLY/DOWNSLOPING WINDS WILL DEVELOP IN RESPONSE TO PRESSURE FALLS ACROSS THE HIGH PLAINS. OPTED TO MAINTAIN THE PREVIOUS FORECAST WITH MINIMAL CHANGES... WITH HIGHS REACHING THE LOW TO POSSIBLY MID 60S ON THE SOUTH PLAINS...TO THE LOW 50S ACROSS THE ROLLING PLAINS WHERE SNOW REMAINS ON THE GROUND. FROM HERE...THE BIG QUESTION MARK REMAINS THE TIMING OF AN APPROACHING ARCTIC COLD FRONT...WHICH MODEL GUIDANCE CONTINUES TO STRUGGLE WITH. OPTED TO SIDE WITH THE SLOWER GFS/ECMWF SOLUTIONS... AS DAYTIME FROPAS TEND TO BE SLOWED BY DEEP MIXING AHEAD OF THEM. SOUTH OF THE FRONT...CONTINUED DOWNSLOPING WESTERLIES WILL LIKELY KEEP TEMPERATURES WARM SUNDAY... WHILE PORTIONS OF THE NORTHERN ROLLING PLAINS BEHIND THE FRONT WILL LIKELY EXPERIENCE A SHARP COOLDOWN. IT SHOULD BE NOTED AS WELL THAT WHILE CRITICAL FIRE WEATHER IS NOT EXPECTED...BREEZY...WARM AND DRY CONDITIONS MAY SLIGHTLY ELEVATED FIRE WEATHER CONDITIONS ACROSS PORTIONS OF THE SOUTHERN SOUTH PLAINS SATURDAY AND SUNDAY. WHILE THE TIMING OF THE FROPA SUNDAY IS STILL IN QUESTION...THERE IS LITTLE DOUBT THAT MONDAY AND MOST LIKELY TUESDAY WILL FEATURE WELL BELOW NORMAL TEMPERATURES ACROSS THE BOARD. LATEST MODEL GUIDANCE CONTINUES TO STRUGGLE REGARDING THE TIMING OF YET ANOTHER PROGRESSIVE SHORTWAVE EMBEDDED WITHIN THE WNW FLOW ALOFT. THE GFS CURRENTLY DEPICTS A FASTER... MORE POSITIVELY TILTED...AND WEAKER WAVE THAN THE ECMWF...WITH A TIMING DIFFERENCE OF ALMOST A FULL 24 HOURS. OPTED TO CONTINUE WITH THE GFS DEPICTION... WITH ENHANCED POPS ACROSS OUR NORTHERN ZONES BEGINNING MONDAY EVENING. ALSO OPTED TO REMOVE MOST OF THE RAIN MENTION...AS LATEST FORECAST TEMPS DROP BELOW FREEZING PRIOR TO THE ONSET OF PRECIPITATION. STILL...UNCERTAINTY REMAINS HIGH WITH THIS SYSTEM... ESPECIALLY ACROSS OUR SOUTHERN ZONES. AS THIS UPPER WAVE DEPARTS... BROAD RIDGING WILL BUILD EASTWARD AND ALLOW A PLEASANT WARMING TREND TO CARRY US INTO THE END OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 41 27 59 29 59 / 10 0 0 0 0 TULIA 38 24 57 29 57 / 10 0 0 0 0 PLAINVIEW 39 24 59 30 60 / 10 0 0 0 0 LEVELLAND 43 27 62 31 62 / 10 0 0 0 0 LUBBOCK 41 26 60 30 60 / 10 0 0 0 0 DENVER CITY 42 28 66 32 66 / 10 0 0 0 0 BROWNFIELD 42 28 61 30 63 / 60 0 0 0 0 CHILDRESS 29 21 53 23 42 / 10 0 0 0 0 SPUR 34 21 51 24 55 / 60 0 0 0 0 ASPERMONT 34 25 59 30 55 / 60 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1001 AM CST FRI FEB 7 2014 .DISCUSSION... THOUGH WARMING...TEMPERATURES ARE STILL AROUND FREEZING ACROSS THE ADVISORY AREA. THE LOWER LEVELS OF THE ATMOSPHERE CONTINUE TO SATURATE AND RADAR IS STARTING TO SHOW SOME RETURNS WHICH COULD EVENTUALLY MAKE IT TO THE SURFACE...MOST LIKELY AS DRIZZLE. ANY PRECIPITATION THAT REACHES THE GROUND...AGAIN MORE LIKELY IN THE FORM OF DRIZZLE...MAY FREEZE ON CONTACT. ACCUMULATIONS IF ANY WILL BE LIGHT BUT STILL HAVE THE POTENTIAL TO CAUSE SOME TRAVEL ISSUES. THREAT OF WET BULBING ALSO A CONCERN IN THE SHORT TERM WITH ANY PRECIP WHERE READINGS ARE CURRENTLY JUST ABOVE FREEZING. WENT AHEAD AND EXTENDED WW ADVSY UNTIL NOON WHICH MATCHES UP W/ NEIGHBORING OFFICES TOO. WE WILL CONTINUE TO MONITOR TEMPERATURE AND RADAR TRENDS AND POSSIBLY FURTHER EXTEND THIS ADVISORY IF NEEDED. OTHERWISE...TWEAKED 1ST PERIOD GRIDS TO ADJUST TEMPS TO MATCH CURRENT TRENDS. NAM12, TX TECH WRF & HRRR SUGGEST INCREASING LIGHT PRECIP COVERAGE 2-9 PM ACROSS THE REGION AS INFLUENCE OF SHORTWAVE BECOMES FELT AND LLVLS FURTHER SATURATE. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 36 32 63 43 66 / 40 20 10 10 10 HOUSTON (IAH) 40 34 63 47 68 / 40 40 10 10 10 GALVESTON (GLS) 42 40 60 53 65 / 30 40 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES: AUSTIN...BRAZOS...BURLESON...COLORADO...GRIMES... MADISON...WALKER...WASHINGTON. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 PM CST THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
517 AM CST FRI FEB 7 2014 .AVIATION... IFR CIGS WITH OCCASIONAL -SN AT LBB THIS MORNING WILL GIVE WAY TO VFR CONDS AND BREEZY SW WINDS BY MIDDAY BEHIND AN UPPER TROUGH. AT MOST WE EXPECT ONLY A DUSTING OF SNOW...SO WILL FOREGO AN AIRPORT WX WARNING. VFR CONDS WILL BE DELAYED AT CDS UNTIL AT LEAST MID-AFTN...BUT THERE IS A SMALL CHANCE LOW CLOUDS MAY LINGER THRU THE EVENING UNTIL DRIER SWLY WINDS FINALLY EMERGE. && .PREV DISCUSSION... /ISSUED 409 AM CST FRI FEB 7 2014/ SHORT TERM... THE LAST IN A STRING OF MINOR TROUGHS WILL ENTER THE SOUTH PLAINS THIS MORNING AND SERVE TO ENHANCE THE COVERAGE OF FLURRIES AND SOME VERY LIGHT SNOW AT TIMES. REGIONAL OBSERVATIONS EARLY THIS A.M. INDICATED PERIODS OF UNMEASURABLE SNOW FROM AMARILLO SOUTH TO LUBBOCK. RECENT HRRR AND NAM APPEAR ON TRACK WITH AN AXIS OF SUSTAINED LIFT TAKING SHAPE FROM THE NRN PERMIAN BASIN INTO THE FAR SRN SOUTH PLAINS NEAR SUNRISE. THIS REGION IS ALREADY BENEFITING FROM PROLONGED /ALBEIT WEAK/ ASCENT IN THE ENTRANCE REGION OF A STOUT 120 KNOT UPPER JET. BUT WITH NO APPRECIABLE UPTICK IN MOISTURE AVAILABLE...ANYTHING MORE THAN A DUSTING APPEARS A BIT TOO HARD TO COME BY IN THIS SETUP. SO WE HAVE PULLED SLIGHT CHANCE POPS IN FAVOR OF FLURRIES BEFORE NIXING THIS MENTION ALTOGETHER BY THE AFTERNOON BEHIND THE EXITING TROUGH. WEST WINDS AND CLEARING SKIES FOLLOWING THE UPPER WAVE WILL TUG MILDER THICKNESSES ACROSS THE CAPROCK...BUT STUBBORN S-SE WINDS OFF THE CAPROCK AND A LINGERING SNOW PACK IN PLACES WILL KEEP HIGHS HERE ABOUT 15 DEGREES COOLER. EXPECT A BIT MORE UNIFORMITY TONIGHT WITH TEMPS AS WESTERLY WINDS OVERSPREAD THE ENTIRE CWA. LONG TERM... AS WE BEGIN THE LONG TERM PERIOD...THE UPPER FLOW PATTERN ACROSS THE CONUS WILL BE RELATIVELY ZONAL...WITH A BROAD MEAN TROUGH ACROSS THE EAST...RIDGE WEST...AND WNW FLOW ALOFT ACROSS THE PLAINS. TWO PRIMARY ITEMS OF INTEREST WILL BE THE TIMING AND MAGNITUDE OF ANOTHER COLD AIRMASS SOMETIME SUNDAY...FOLLOWED BY A PROGRESSIVE UPPER WAVE MONDAY/TUESDAY WHICH WILL BRING WITH IT ANOTHER CHANCE FOR WINTER WEATHER ACROSS WEST TEXAS. SATURDAY IS EXPECTED TO BE QUITE WARM ACROSS THE AREA...AS BREEZY WESTERLY/DOWNSLOPING WINDS WILL DEVELOP IN RESPONSE TO PRESSURE FALLS ACROSS THE HIGH PLAINS. OPTED TO MAINTAIN THE PREVIOUS FORECAST WITH MINIMAL CHANGES... WITH HIGHS REACHING THE LOW TO POSSIBLY MID 60S ON THE SOUTH PLAINS...TO THE LOW 50S ACROSS THE ROLLING PLAINS WHERE SNOW REMAINS ON THE GROUND. FROM HERE...THE BIG QUESTION MARK REMAINS THE TIMING OF AN APPROACHING ARCTIC COLD FRONT...WHICH MODEL GUIDANCE CONTINUES TO STRUGGLE WITH. OPTED TO SIDE WITH THE SLOWER GFS/ECMWF SOLUTIONS... AS DAYTIME FROPAS TEND TO BE SLOWED BY DEEP MIXING AHEAD OF THEM. SOUTH OF THE FRONT...CONTINUED DOWNSLOPING WESTERLIES WILL LIKELY KEEP TEMPERATURES WARM SUNDAY... WHILE PORTIONS OF THE NORTHERN ROLLING PLAINS BEHIND THE FRONT WILL LIKELY EXPERIENCE A SHARP COOLDOWN. IT SHOULD BE NOTED AS WELL THAT WHILE CRITICAL FIRE WEATHER IS NOT EXPECTED...BREEZY...WARM AND DRY CONDITIONS MAY SLIGHTLY ELEVATED FIRE WEATHER CONDITIONS ACROSS PORTIONS OF THE SOUTHERN SOUTH PLAINS SATURDAY AND SUNDAY. WHILE THE TIMING OF THE FROPA SUNDAY IS STILL IN QUESTION...THERE IS LITTLE DOUBT THAT MONDAY AND MOST LIKELY TUESDAY WILL FEATURE WELL BELOW NORMAL TEMPERATURES ACROSS THE BOARD. LATEST MODEL GUIDANCE CONTINUES TO STRUGGLE REGARDING THE TIMING OF YET ANOTHER PROGRESSIVE SHORTWAVE EMBEDDED WITHIN THE WNW FLOW ALOFT. THE GFS CURRENTLY DEPICTS A FASTER... MORE POSITIVELY TILTED...AND WEAKER WAVE THAN THE ECMWF...WITH A TIMING DIFFERENCE OF ALMOST A FULL 24 HOURS. OPTED TO CONTINUE WITH THE GFS DEPICTION... WITH ENHANCED POPS ACROSS OUR NORTHERN ZONES BEGINNING MONDAY EVENING. ALSO OPTED TO REMOVE MOST OF THE RAIN MENTION...AS LATEST FORECAST TEMPS DROP BELOW FREEZING PRIOR TO THE ONSET OF PRECIPITATION. STILL...UNCERTAINTY REMAINS HIGH WITH THIS SYSTEM... ESPECIALLY ACROSS OUR SOUTHERN ZONES. AS THIS UPPER WAVE DEPARTS... BROAD RIDGING WILL BUILD EASTWARD AND ALLOW A PLEASANT WARMING TREND TO CARRY US INTO THE END OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 41 27 59 29 59 / 10 0 0 0 0 TULIA 38 24 57 29 57 / 10 0 0 0 0 PLAINVIEW 39 24 59 30 60 / 10 0 0 0 0 LEVELLAND 43 27 62 31 62 / 10 0 0 0 0 LUBBOCK 41 26 60 30 60 / 10 0 0 0 0 DENVER CITY 42 28 66 32 66 / 10 0 0 0 0 BROWNFIELD 42 28 61 30 63 / 10 0 0 0 0 CHILDRESS 29 21 53 23 42 / 10 0 0 0 0 SPUR 34 21 51 24 55 / 10 0 0 0 0 ASPERMONT 34 25 59 30 55 / 10 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 93/93/16
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
409 AM CST FRI FEB 7 2014 .SHORT TERM... THE LAST IN A STRING OF MINOR TROUGHS WILL ENTER THE SOUTH PLAINS THIS MORNING AND SERVE TO ENHANCE THE COVERAGE OF FLURRIES AND SOME VERY LIGHT SNOW AT TIMES. REGIONAL OBSERVATIONS EARLY THIS A.M. INDICATED PERIODS OF UNMEASURABLE SNOW FROM AMARILLO SOUTH TO LUBBOCK. RECENT HRRR AND NAM APPEAR ON TRACK WITH AN AXIS OF SUSTAINED LIFT TAKING SHAPE FROM THE NRN PERMIAN BASIN INTO THE FAR SRN SOUTH PLAINS NEAR SUNRISE. THIS REGION IS ALREADY BENEFITING FROM PROLONGED /ALBEIT WEAK/ ASCENT IN THE ENTRANCE REGION OF A STOUT 120 KNOT UPPER JET. BUT WITH NO APPRECIABLE UPTICK IN MOISTURE AVAILABLE...ANYTHING MORE THAN A DUSTING APPEARS A BIT TOO HARD TO COME BY IN THIS SETUP. SO WE HAVE PULLED SLIGHT CHANCE POPS IN FAVOR OF FLURRIES BEFORE NIXING THIS MENTION ALTOGETHER BY THE AFTERNOON BEHIND THE EXITING TROUGH. WEST WINDS AND CLEARING SKIES FOLLOWING THE UPPER WAVE WILL TUG MILDER THICKNESSES ACROSS THE CAPROCK...BUT STUBBORN S-SE WINDS OFF THE CAPROCK AND A LINGERING SNOW PACK IN PLACES WILL KEEP HIGHS HERE ABOUT 15 DEGREES COOLER. EXPECT A BIT MORE UNIFORMITY TONIGHT WITH TEMPS AS WESTERLY WINDS OVERSPREAD THE ENTIRE CWA. && .LONG TERM... AS WE BEGIN THE LONG TERM PERIOD...THE UPPER FLOW PATTERN ACROSS THE CONUS WILL BE RELATIVELY ZONAL...WITH A BROAD MEAN TROUGH ACROSS THE EAST...RIDGE WEST...AND WNW FLOW ALOFT ACROSS THE PLAINS. TWO PRIMARY ITEMS OF INTEREST WILL BE THE TIMING AND MAGNITUDE OF ANOTHER COLD AIRMASS SOMETIME SUNDAY...FOLLOWED BY A PROGRESSIVE UPPER WAVE MONDAY/TUESDAY WHICH WILL BRING WITH IT ANOTHER CHANCE FOR WINTER WEATHER ACROSS WEST TEXAS. SATURDAY IS EXPECTED TO BE QUITE WARM ACROSS THE AREA...AS BREEZY WESTERLY/DOWNSLOPING WINDS WILL DEVELOP IN RESPONSE TO PRESSURE FALLS ACROSS THE HIGH PLAINS. OPTED TO MAINTAIN THE PREVIOUS FORECAST WITH MINIMAL CHANGES... WITH HIGHS REACHING THE LOW TO POSSIBLY MID 60S ON THE SOUTH PLAINS...TO THE LOW 50S ACROSS THE ROLLING PLAINS WHERE SNOW REMAINS ON THE GROUND. FROM HERE...THE BIG QUESTION MARK REMAINS THE TIMING OF AN APPROACHING ARCTIC COLD FRONT...WHICH MODEL GUIDANCE CONTINUES TO STRUGGLE WITH. OPTED TO SIDE WITH THE SLOWER GFS/ECMWF SOLUTIONS... AS DAYTIME FROPAS TEND TO BE SLOWED BY DEEP MIXING AHEAD OF THEM. SOUTH OF THE FRONT...CONTINUED DOWNSLOPING WESTERLIES WILL LIKELY KEEP TEMPERATURES WARM SUNDAY... WHILE PORTIONS OF THE NORTHERN ROLLING PLAINS BEHIND THE FRONT WILL LIKELY EXPERIENCE A SHARP COOLDOWN. IT SHOULD BE NOTED AS WELL THAT WHILE CRITICAL FIRE WEATHER IS NOT EXPECTED...BREEZY...WARM AND DRY CONDITIONS MAY SLIGHTLY ELEVATED FIRE WEATHER CONDITIONS ACROSS PORTIONS OF THE SOUTHERN SOUTH PLAINS SATURDAY AND SUNDAY. WHILE THE TIMING OF THE FROPA SUNDAY IS STILL IN QUESTION...THERE IS LITTLE DOUBT THAT MONDAY AND MOST LIKELY TUESDAY WILL FEATURE WELL BELOW NORMAL TEMPERATURES ACROSS THE BOARD. LATEST MODEL GUIDANCE CONTINUES TO STRUGGLE REGARDING THE TIMING OF YET ANOTHER PROGRESSIVE SHORTWAVE EMBEDDED WITHIN THE WNW FLOW ALOFT. THE GFS CURRENTLY DEPICTS A FASTER... MORE POSITIVELY TILTED...AND WEAKER WAVE THAN THE ECMWF...WITH A TIMING DIFFERENCE OF ALMOST A FULL 24 HOURS. OPTED TO CONTINUE WITH THE GFS DEPICTION... WITH ENHANCED POPS ACROSS OUR NORTHERN ZONES BEGINNING MONDAY EVENING. ALSO OPTED TO REMOVE MOST OF THE RAIN MENTION...AS LATEST FORECAST TEMPS DROP BELOW FREEZING PRIOR TO THE ONSET OF PRECIPITATION. STILL...UNCERTAINTY REMAINS HIGH WITH THIS SYSTEM... ESPECIALLY ACROSS OUR SOUTHERN ZONES. AS THIS UPPER WAVE DEPARTS... BROAD RIDGING WILL BUILD EASTWARD AND ALLOW A PLEASANT WARMING TREND TO CARRY US INTO THE END OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 41 27 59 29 59 / 10 0 0 0 0 TULIA 38 24 57 29 57 / 10 0 0 0 0 PLAINVIEW 39 24 59 30 60 / 10 0 0 0 0 LEVELLAND 43 27 62 31 62 / 10 0 0 0 0 LUBBOCK 41 26 60 30 60 / 10 0 0 0 0 DENVER CITY 42 28 66 32 66 / 10 0 0 0 0 BROWNFIELD 42 28 61 30 63 / 10 0 0 0 0 CHILDRESS 29 21 53 23 42 / 10 0 0 0 0 SPUR 34 21 51 24 55 / 10 0 0 0 0 ASPERMONT 34 25 59 30 55 / 10 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 93/16
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1139 PM CST THU FEB 6 2014 .AVIATION... LATEST MODEL RUNS ARE NOT DOING ANYTHING TO HELP CONFIDENCE IN THE TAFS. PREVIOUS DISCUSSIONS GAVE THE HIGHLIGHTS OF THE CHANGES. HOWEVER...CONFIDENCE IN ONE TERMINAL OVER ANOTHER IS QUITE PROBLEMATIC. FOR ALL SITES...AM GOING WITH A COMBINATION OF VFR CEILINGS TONIGHT...FOLLOWED BY MVFR CEILINGS IN THE MORNING HOURS. THE LATEST RUNS OF THE VARIOUS HIGH RESOLUTION GUIDANCE...AND THE LARGER SCALE MODELS ARE ALL SUGGESTING SOME BANDED PRECIPITATION A BIT LATER IN THE DAY FRIDAY. PRECIPITATION IS NOT MENTIONED IN THE 06Z TAFS...BUT IS A POSSIBILITY. WILL CONTINUE TO MONITOR THE UPPER STORM AS IT MOVES ACROSS THE REGION FRIDAY. FOX && .UPDATE... AS ONE DISTURBANCE MOVES AWAY FROM NORTH TEXAS...ANOTHER ONE CAN BE SEEN ON THIS EVENING/S WATER VAPOR IMAGERY APPROACHING FROM THE WEST. THIS SHORTWAVE TROUGH IS CURRENTLY SWINGING EAST ACROSS NORTHWEST MEXICO AND IS PROGGED TO REACH WEST TEXAS EARLY TOMORROW MORNING...THEN SWING ACROSS NORTH AND CENTRAL TEXAS DURING THE MIDDLE PART OF THE DAY. MOISTURE AVAILABILITY FOR PRECIPITATION WILL BE BEST OVER THE SOUTHERN COUNTIES OF NORTH TEXAS AS THE SYSTEM PASSES OVERHEAD...AND A WINTER WEATHER ADVISORY WILL REMAIN OVER AREAS GENERALLY ALONG AND SOUTH OF A GOLDTHWAITE TO CANTON LINE. FARTHER NORTH...LIMITED MOISTURE SHOULD PRECLUDE THE ADDITION OF A WINTER WEATHER ADVISORY AT THIS TIME. HOWEVER...THE 00Z GFS HAS INDICATED SLIGHTLY HIGHER LEVELS OF MOISTURE. WITH MODEST LIFT ALREADY PROGGED TO BE IN PLACE....SOME LOCATIONS COULD PICK UP SLIGHTLY HIGHER SNOW TOTALS THAN PREVIOUSLY ADVERTISED. THE AREA MOST LIKELY TO RECEIVE THE SLIGHTLY HIGHER SNOWFALL TOTALS WOULD BE AREAS IMMEDIATELY NORTH AND NORTHEAST OF THE DALLAS-FORT WORTH METROPLEX. ONE POSSIBLE REASON FOR THIS COULD BE THAT THE SYSTEM WILL BEGIN ACQUIRING ADDITIONAL GULF MOISTURE JUST BEFORE ACCELERATING NORTHEAST OF THE REGION. WHATEVER THE CASE MAY BE...THE ONE UPDATE THIS EVENING HAS BEEN TO BUMP POPS UP TO CHANCE CATEGORY NORTH AND NORTHEAST OF THE METROPLEX AND ADD SOME SNOWFALL TOTALS BETWEEN 0.2 AND 0.4 INCHES IN THESE LOCATIONS. THIS KEEPS DALLAS FORT WORTH PROPER IN THE DUSTING TO 0.2 INCH RANGE WHICH SHOULD NOT REQUIRE A WINTER WEATHER ADVISORY. OTHERWISE...ONLY MINOR UPDATES TO THE OVERNIGHT GRIDS WERE NEEDED. 30 && .PREV DISCUSSION... /ISSUED 356 PM CST THU FEB 6 2014/ THE UPPER LEVEL DISTURBANCE RESPONSIBLE FOR THE SNOW OVER THE NORTHERN HALF OF THE CWA TODAY HAS MOVED QUICKLY OFF TO THE EAST BUT THE NEXT ONE IS RIGHT ON ITS HEELS. THIS UPPER LEVEL SHORTWAVE IS CURRENTLY LOCATED IN SOUTHERN CALIFORNIA AND WILL RAPIDLY MOVE EAST AND MOVE ACROSS TEXAS DURING THE DAY TOMORROW. MOST MODEL GUIDANCE DID NOT HANDLE THE STRENGTH OF THE FIRST SYSTEM VERY WELL...BUT THE BETTER PERFORMERS WERE THE NAM AND RAP AND THEREFORE WILL BE LEANING IN THEIR DIRECTION FOR THE FORECAST. HOWEVER CONFIDENCE IN TOMORROWS FORECAST IS VERY LOW GIVEN OUR FORECAST OF FREEZING AND FROZEN PRECIP IS NOT REALLY SUPPORTED IN JUST ABOUT ALL OF THE MODEL GUIDANCE...BUT WE ARE WARY OF THE STRENGTH OF THIS NEXT SYSTEM ALSO BEING UNDERESTIMATED. ONCE AGAIN FORCING FOR ASCENT WILL BE STRONG BUT THE MAIN ISSUE IS THE AMOUNT OF MOISTURE AVAILABLE FOR PRECIPITATION. THERE IS ACTUALLY GOOD MODEL AGREEMENT THAT HIGH MOISTURE AND CONDITIONAL SYMMETRIC INSTABILITY WILL BE AVAILABLE FOR SLANTWISE CONVECTION AND BANDED SNOWFALL IN THE AREA OF THE ATMOSPHERE NEAR 500 TO 600MB OR NEAR 18-22 THOUSAND FEET. THIS BAND IS EXPECTED TO TRACK ACROSS THE AREA ALONG AND NORTH OF INTERSTATE 20 DURING THE DAY TOMORROW AND WILL LIKELY BE SEEN ON AREA RADARS. THE MODELS DIFFER ON JUST HOW DRY THE AIRMASS WILL BE IN A LAYER NEAR 700 TO 850MB OR ABOUT 5-10 THOUSAND FEET. WITH THE SOLE EXCEPTION OF THE ECMWF AND ONE SREF MEMBER...ALL MODEL GUIDANCE INDICATES THE FALLING SNOW WILL SUBLIMATE WHEN IT REACHES THIS DRY LAYER AND NOT REACH THE SURFACE. HOWEVER AM NOT READY TO BUY INTO THIS JUST YET...AT LEAST NOT UNTIL WE CAN SEE THE MOISTURE PROFILES FROM THE EVENING RAOBS AT MAF AND DRT. OBVIOUSLY THERE WAS A LOT MORE MOISTURE AVAILABLE IN THE AREA THAN WAS FORECAST TODAY AND IT IS LIKELY STILL HANGING AROUND. SINCE MODEL SOUNDINGS FROM BOTH THE RAP AND NAM INDICATE FAIRLY STEEP LAPSE RATES IN THE SNOW PRODUCING AREA WHICH WOULD ENHANCE SNOWFALL INTENSITY...BELIEVE MORE SATURATION WILL OCCUR FROM TOP DOWN THAN MODELS INDICATE. THUS WILL FORECAST ANOTHER ROUND OF LIGHT SNOW ACROSS THE AREA NORTH OF I-20 TOMORROW...WITH POPS FOR MEASURABLE AMOUNTS OF SNOW AT 20 PERCENT AND ACCUMULATIONS AT JUST A TENTH OF AN INCH OR LESS. FARTHER SOUTH ACROSS CENTRAL TEXAS AND OUR SOUTHEAST ZONES...THE SOUTHERLY WINDS AT 850MB WILL BE BRINGING WARMER AIR AND RICH GULF MOISTURE NORTHWARD IN A HURRY AS THE SHORTWAVE APPROACHES. LOW LEVEL ISENTROPIC CHARTS SHOW SUBTLE LIFT OCCURRING NEAR 925MB WHICH WOULD CORRESPOND TO SOME LIGHT DRIZZLE DEVELOPING BEFORE DAY BREAK. TEMPERATURES AT THIS TIME WOULD BE BELOW FREEZING. PRECIPITATION WILL LIKELY INCREASE IN COVERAGE AND INTENSITY ACROSS THE SOUTHEAST ZONES DURING THE AFTERNOON HOURS AS ISENTROPIC LIFT RAMPS UP. HOWEVER TEMPERATURES MAY RISE ABOVE FREEZING BEFORE THIS OCCURS. MODEL GUIDANCE MAY BE TOO QUICK TO WARM TEMPS ABOVE FREEZING AS NORTH WINDS WILL HOLD IN THROUGH THE MORNING HOURS AND THICK CLOUD COVER SHOULD KEEP TEMPS FROM RISING MUCH IF ANY. HOWEVER WHEN THE PRECIP STARTS IT IS ASSOCIATED WITH LOW LEVEL WARM ADVECTION...AND BELIEVE THAT TEMPS WILL TRY TO WARM ABOVE FREEZING DURING THE AFTERNOON FROM SOUTHWEST TO NORTHEAST. SO IT MAY START AS LIGHT FREEZING DRIZZLE/RAIN BUT SHOULD TRANSITION TO REGULAR DRIZZLE OR RAIN DURING THE EVENT. AFTER A COUPLE OF DAYS OF VERY COLD SUBFREEZING TEMPS...ROAD SURFACES ARE BELOW FREEZING AND ANY FREEZING PRECIPITATION WOULD STICK ON IMPACT. DO NOT EXPECT MUCH ACCUMULATION OF ICE AS PRECIPITATION INTENSITY WILL BE LIGHT...BUT STILL THIS CAN BE A MAJOR TRAFFIC HAZARD ESPECIALLY IF PEOPLE ARE NOT AWARE OF ICE ON ROADS. HAVE ISSUED A WINTER WEATHER ADVISORY ACROSS THE SOUTHERN AND SOUTHEAST ZONES FOR THE LIGHT FREEZING PRECIPITATION TO GET THE WORD OUT ABOUT THE POTENTIAL TRAVEL ISSUES TOMORROW. THANKS TO WFO EWX/HGX/SHV FOR THE COORDINATION. THIS SYSTEM WILL CLEAR THE AREA FRIDAY NIGHT WITH SKIES CLEARING SATURDAY. TEMPERATURES WILL REBOUND INTO THE 50S AND 60S BY SATURDAY AFTERNOON AS DOWN SLOPE WESTERLY WINDS SPREAD ACROSS THE REGION. THE WARM UP WILL BE SHORT LIVED AS ANOTHER FRONT SLIDES SOUTH THROUGH THE AREA ON SUNDAY. HAVE SIDED WITH THE FASTER ECMWF/GFS FORECASTS WITH THIS FRONT...AS IT IS LIKELY TO BE SHALLOW AND WANT TO SPILL SOUTH DUE TO ITS HIGHER DENSITY. THE EARLY NEXT WEEK FORECAST WILL FEATURE INCREASING CHANCES OF PRECIPITATION. THE COLD AIR BEHIND THE SUNDAY FRONT WILL SETTLE IN OVER THE AREA WITH HIGHS IN THE 40S AND LOWS IN THE 30S. AS ANOTHER STRONG UPPER LEVEL SYSTEM MOVES IN FROM THE WEST... ISENTROPIC LIFT WILL SET UP OVER THE TOP OF THE COLD DOME AND WE SHOULD SEE CHANCES OF PRECIP STARTING MONDAY AND INCREASING INTO TUESDAY. THE GFS AND CANADIAN ARE MOST AGGRESSIVE WITH QPF OUTPUT WITH THIS SYSTEM BUT THE ECMWF CONTINUES TO BE RATHER TAME. FURTHERMORE THE GFS/CANADIAN WOULD SUPPORT A WIDESPREAD WINTER MIX EVENT FOR THE REGION...BUT AGAIN THE ECMWF DOES NOT SHOW THIS. FOR NOW WE WILL CONTINUE TO ADVERTISE SOME WINTER PRECIP OVER THE NORTHERN 2 ROWS OF COUNTIES TUESDAY AND TUESDAY NIGHT. THIS IS THE REGION THAT IS MOST CLIMATOLOGICALLY FAVORED TO SEE WINTER PRECIP AND WITH MODEL AGREEMENT LOW...IT MAKES SENSE TO KEEP THE WINTER MIX UP THERE AND SPREAD IT SOUTH SHOULD THE ECMWF COME IN LINE WITH THE OTHER GUIDANCE AND CONFIDENCE INCREASES. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 21 34 29 57 34 / 10 30 10 0 0 WACO, TX 23 35 29 64 38 / 20 20 10 0 0 PARIS, TX 21 33 25 53 33 / 10 30 20 0 0 DENTON, TX 19 33 26 56 30 / 10 30 10 0 0 MCKINNEY, TX 21 33 26 55 31 / 10 30 10 0 0 DALLAS, TX 22 34 30 57 37 / 10 30 10 0 0 TERRELL, TX 23 34 27 57 34 / 10 20 10 0 0 CORSICANA, TX 24 34 30 60 38 / 10 30 10 0 0 TEMPLE, TX 24 35 29 65 38 / 20 30 10 0 0 MINERAL WELLS, TX 19 37 26 60 31 / 10 20 10 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 5 AM TO 3 PM CST FRIDAY FOR TXZ156>160-174-175. WINTER WEATHER ADVISORY FROM 9 AM TO 6 PM CST FRIDAY FOR TXZ122- 135-146>148-161-162. && $$ 14/30
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1034 PM CST THU FEB 6 2014 .UPDATE... AS ONE DISTURBANCE MOVES AWAY FROM NORTH TEXAS...ANOTHER ONE CAN BE SEEN ON THIS EVENING/S WATER VAPOR IMAGERY APPROACHING FROM THE WEST. THIS SHORTWAVE TROUGH IS CURRENTLY SWINGING EAST ACROSS NORTHWEST MEXICO AND IS PROGGED TO REACH WEST TEXAS EARLY TOMORROW MORNING...THEN SWING ACROSS NORTH AND CENTRAL TEXAS DURING THE MIDDLE PART OF THE DAY. MOISTURE AVAILABILITY FOR PRECIPITATION WILL BE BEST OVER THE SOUTHERN COUNTIES OF NORTH TEXAS AS THE SYSTEM PASSES OVERHEAD...AND A WINTER WEATHER ADVISORY WILL REMAIN OVER AREAS GENERALLY ALONG AND SOUTH OF A GOLDTHWAITE TO CANTON LINE. FARTHER NORTH...LIMITED MOISTURE SHOULD PRECLUDE THE ADDITION OF A WINTER WEATHER ADVISORY AT THIS TIME. HOWEVER...THE 00Z GFS HAS INDICATED SLIGHTLY HIGHER LEVELS OF MOISTURE. WITH MODEST LIFT ALREADY PROGGED TO BE IN PLACE....SOME LOCATIONS COULD PICK UP SLIGHTLY HIGHER SNOW TOTALS THAN PREVIOUSLY ADVERTISED. THE AREA MOST LIKELY TO RECEIVE THE SLIGHTLY HIGHER SNOWFALL TOTALS WOULD BE AREAS IMMEDIATELY NORTH AND NORTHEAST OF THE DALLAS-FORT WORTH METROPLEX. ONE POSSIBLE REASON FOR THIS COULD BE THAT THE SYSTEM WILL BEGIN ACQUIRING ADDITIONAL GULF MOISTURE JUST BEFORE ACCELERATING NORTHEAST OF THE REGION. WHATEVER THE CASE MAY BE...THE ONE UPDATE THIS EVENING HAS BEEN TO BUMP POPS UP TO CHANCE CATEGORY NORTH AND NORTHEAST OF THE METROPLEX AND ADD SOME SNOWFALL TOTALS BETWEEN 0.2 AND 0.4 INCHES IN THESE LOCATIONS. THIS KEEPS DALLAS FORT WORTH PROPER IN THE DUSTING TO 0.2 INCH RANGE WHICH SHOULD NOT REQUIRE A WINTER WEATHER ADVISORY. OTHERWISE...ONLY MINOR UPDATES TO THE OVERNIGHT GRIDS WERE NEEDED. 30 && .AVIATION... INTERESTING FORECAST OVERNIGHT AND THEN AGAIN TOMORROW. FOR THE TAFS...THERE WILL CONTINUE TO BE OVERCAST SKIES...WITH CEILINGS HOVERING AROUND 030BKN/OVC. WINDS REMAIN GENERALLY NORTH AND NORTHEAST AROUND 10KNOTS. THE BIG QUESTIONS OCCUR TOMORROW. HIGHEST CONFIDENCE REMAINS IN THE SOUTH AND HAVE CONTINUED TO CARRY A MIXTURE OF LIGHT RAIN OR A MIX OF FREEZING RAIN AND SLEET. THIS DOESN`T OCCUR UNTIL LATE IN THE FORECAST...ROUGHLY AROUND 18Z. IN THE NORTH...CONFIDENCE REMAINS TOO LOW TO MENTION PRECIPITATION IN THE METROPLEX AREA TAFS...ALTHOUGH IT APPEARS LIKELY THAT WE WILL SEE AT LEAST SOME FLURRIES AGAIN ON FRIDAY. TAKING A PEEK AT THE INCOMING MODEL GUIDANCE...THE NAM CONTINUES TO BE BONE DRY. HOWEVER...LIKE TODAY...THERE IS MOISTURE AND PLENTY OF LIFT. NEWEST NAM SOUNDINGS SUGGEST A HINT AT ELEVATED CAPE WHICH COULD LEAD TO A FEW MORE MESOSCALE BANDS IN THE NORTHERN HALF OF THE AREA. HOWEVER...HAVE YET TO SEE THE FULL RESOLUTION SOUNDINGS SO AM NOT YET SURE IF THIS IS AN ACCURATE INTERPRETATION OF THE AVAILABLE DATA. LOCAL WRF OUTPUT SUGGESTS A COUPLE OF MESOSCALE BANDS IN THE AFTERNOON HOURS ACROSS THE AREA. THIS MODEL ALSO PICKED UP ON THE BANDING FEATURES THIS MORNING...BUT DID NOT PLACE THEM IN THE RIGHT SPOT. SO...CONFIDENCE IS INCREASING IN A FEW THINGS. FIRST...THERE WILL LIKELY BE ANOTHER SHOT AT MAINLY LIGHT SNOW OR FLURRIES ACROSS THE REGION TOMORROW. EXACTLY WHERE THE BANDS SET UP IS VERY MUCH UNCERTAIN. SECOND...THE LOCAL WRF...THE 21Z SREF...AND THE LATEST 00Z NAM ARE ALSO SUGGESTING THAT OUR CURRENT FORECAST IS ON TRACK. WILL CONTINUE TO WATCH WHAT THE REMAINING GUIDANCE GIVES US. FOX && .PREV DISCUSSION... /ISSUED 356 PM CST THU FEB 6 2014/ THE UPPER LEVEL DISTURBANCE RESPONSIBLE FOR THE SNOW OVER THE NORTHERN HALF OF THE CWA TODAY HAS MOVED QUICKLY OFF TO THE EAST BUT THE NEXT ONE IS RIGHT ON ITS HEELS. THIS UPPER LEVEL SHORTWAVE IS CURRENTLY LOCATED IN SOUTHERN CALIFORNIA AND WILL RAPIDLY MOVE EAST AND MOVE ACROSS TEXAS DURING THE DAY TOMORROW. MOST MODEL GUIDANCE DID NOT HANDLE THE STRENGTH OF THE FIRST SYSTEM VERY WELL...BUT THE BETTER PERFORMERS WERE THE NAM AND RAP AND THEREFORE WILL BE LEANING IN THEIR DIRECTION FOR THE FORECAST. HOWEVER CONFIDENCE IN TOMORROWS FORECAST IS VERY LOW GIVEN OUR FORECAST OF FREEZING AND FROZEN PRECIP IS NOT REALLY SUPPORTED IN JUST ABOUT ALL OF THE MODEL GUIDANCE...BUT WE ARE WARY OF THE STRENGTH OF THIS NEXT SYSTEM ALSO BEING UNDERESTIMATED. ONCE AGAIN FORCING FOR ASCENT WILL BE STRONG BUT THE MAIN ISSUE IS THE AMOUNT OF MOISTURE AVAILABLE FOR PRECIPITATION. THERE IS ACTUALLY GOOD MODEL AGREEMENT THAT HIGH MOISTURE AND CONDITIONAL SYMMETRIC INSTABILITY WILL BE AVAILABLE FOR SLANTWISE CONVECTION AND BANDED SNOWFALL IN THE AREA OF THE ATMOSPHERE NEAR 500 TO 600MB OR NEAR 18-22 THOUSAND FEET. THIS BAND IS EXPECTED TO TRACK ACROSS THE AREA ALONG AND NORTH OF INTERSTATE 20 DURING THE DAY TOMORROW AND WILL LIKELY BE SEEN ON AREA RADARS. THE MODELS DIFFER ON JUST HOW DRY THE AIRMASS WILL BE IN A LAYER NEAR 700 TO 850MB OR ABOUT 5-10 THOUSAND FEET. WITH THE SOLE EXCEPTION OF THE ECMWF AND ONE SREF MEMBER...ALL MODEL GUIDANCE INDICATES THE FALLING SNOW WILL SUBLIMATE WHEN IT REACHES THIS DRY LAYER AND NOT REACH THE SURFACE. HOWEVER AM NOT READY TO BUY INTO THIS JUST YET...AT LEAST NOT UNTIL WE CAN SEE THE MOISTURE PROFILES FROM THE EVENING RAOBS AT MAF AND DRT. OBVIOUSLY THERE WAS A LOT MORE MOISTURE AVAILABLE IN THE AREA THAN WAS FORECAST TODAY AND IT IS LIKELY STILL HANGING AROUND. SINCE MODEL SOUNDINGS FROM BOTH THE RAP AND NAM INDICATE FAIRLY STEEP LAPSE RATES IN THE SNOW PRODUCING AREA WHICH WOULD ENHANCE SNOWFALL INTENSITY...BELIEVE MORE SATURATION WILL OCCUR FROM TOP DOWN THAN MODELS INDICATE. THUS WILL FORECAST ANOTHER ROUND OF LIGHT SNOW ACROSS THE AREA NORTH OF I-20 TOMORROW...WITH POPS FOR MEASURABLE AMOUNTS OF SNOW AT 20 PERCENT AND ACCUMULATIONS AT JUST A TENTH OF AN INCH OR LESS. FARTHER SOUTH ACROSS CENTRAL TEXAS AND OUR SOUTHEAST ZONES...THE SOUTHERLY WINDS AT 850MB WILL BE BRINGING WARMER AIR AND RICH GULF MOISTURE NORTHWARD IN A HURRY AS THE SHORTWAVE APPROACHES. LOW LEVEL ISENTROPIC CHARTS SHOW SUBTLE LIFT OCCURRING NEAR 925MB WHICH WOULD CORRESPOND TO SOME LIGHT DRIZZLE DEVELOPING BEFORE DAY BREAK. TEMPERATURES AT THIS TIME WOULD BE BELOW FREEZING. PRECIPITATION WILL LIKELY INCREASE IN COVERAGE AND INTENSITY ACROSS THE SOUTHEAST ZONES DURING THE AFTERNOON HOURS AS ISENTROPIC LIFT RAMPS UP. HOWEVER TEMPERATURES MAY RISE ABOVE FREEZING BEFORE THIS OCCURS. MODEL GUIDANCE MAY BE TOO QUICK TO WARM TEMPS ABOVE FREEZING AS NORTH WINDS WILL HOLD IN THROUGH THE MORNING HOURS AND THICK CLOUD COVER SHOULD KEEP TEMPS FROM RISING MUCH IF ANY. HOWEVER WHEN THE PRECIP STARTS IT IS ASSOCIATED WITH LOW LEVEL WARM ADVECTION...AND BELIEVE THAT TEMPS WILL TRY TO WARM ABOVE FREEZING DURING THE AFTERNOON FROM SOUTHWEST TO NORTHEAST. SO IT MAY START AS LIGHT FREEZING DRIZZLE/RAIN BUT SHOULD TRANSITION TO REGULAR DRIZZLE OR RAIN DURING THE EVENT. AFTER A COUPLE OF DAYS OF VERY COLD SUBFREEZING TEMPS...ROAD SURFACES ARE BELOW FREEZING AND ANY FREEZING PRECIPITATION WOULD STICK ON IMPACT. DO NOT EXPECT MUCH ACCUMULATION OF ICE AS PRECIPITATION INTENSITY WILL BE LIGHT...BUT STILL THIS CAN BE A MAJOR TRAFFIC HAZARD ESPECIALLY IF PEOPLE ARE NOT AWARE OF ICE ON ROADS. HAVE ISSUED A WINTER WEATHER ADVISORY ACROSS THE SOUTHERN AND SOUTHEAST ZONES FOR THE LIGHT FREEZING PRECIPITATION TO GET THE WORD OUT ABOUT THE POTENTIAL TRAVEL ISSUES TOMORROW. THANKS TO WFO EWX/HGX/SHV FOR THE COORDINATION. THIS SYSTEM WILL CLEAR THE AREA FRIDAY NIGHT WITH SKIES CLEARING SATURDAY. TEMPERATURES WILL REBOUND INTO THE 50S AND 60S BY SATURDAY AFTERNOON AS DOWN SLOPE WESTERLY WINDS SPREAD ACROSS THE REGION. THE WARM UP WILL BE SHORT LIVED AS ANOTHER FRONT SLIDES SOUTH THROUGH THE AREA ON SUNDAY. HAVE SIDED WITH THE FASTER ECMWF/GFS FORECASTS WITH THIS FRONT...AS IT IS LIKELY TO BE SHALLOW AND WANT TO SPILL SOUTH DUE TO ITS HIGHER DENSITY. THE EARLY NEXT WEEK FORECAST WILL FEATURE INCREASING CHANCES OF PRECIPITATION. THE COLD AIR BEHIND THE SUNDAY FRONT WILL SETTLE IN OVER THE AREA WITH HIGHS IN THE 40S AND LOWS IN THE 30S. AS ANOTHER STRONG UPPER LEVEL SYSTEM MOVES IN FROM THE WEST... ISENTROPIC LIFT WILL SET UP OVER THE TOP OF THE COLD DOME AND WE SHOULD SEE CHANCES OF PRECIP STARTING MONDAY AND INCREASING INTO TUESDAY. THE GFS AND CANADIAN ARE MOST AGGRESSIVE WITH QPF OUTPUT WITH THIS SYSTEM BUT THE ECMWF CONTINUES TO BE RATHER TAME. FURTHERMORE THE GFS/CANADIAN WOULD SUPPORT A WIDESPREAD WINTER MIX EVENT FOR THE REGION...BUT AGAIN THE ECMWF DOES NOT SHOW THIS. FOR NOW WE WILL CONTINUE TO ADVERTISE SOME WINTER PRECIP OVER THE NORTHERN 2 ROWS OF COUNTIES TUESDAY AND TUESDAY NIGHT. THIS IS THE REGION THAT IS MOST CLIMATOLOGICALLY FAVORED TO SEE WINTER PRECIP AND WITH MODEL AGREEMENT LOW...IT MAKES SENSE TO KEEP THE WINTER MIX UP THERE AND SPREAD IT SOUTH SHOULD THE ECMWF COME IN LINE WITH THE OTHER GUIDANCE AND CONFIDENCE INCREASES. TR.92 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 21 34 29 57 34 / 10 20 10 0 0 WACO, TX 23 35 29 64 38 / 20 20 10 0 0 PARIS, TX 21 33 25 53 33 / 10 20 20 0 0 DENTON, TX 19 33 26 56 30 / 10 20 10 0 0 MCKINNEY, TX 21 33 26 55 31 / 10 20 10 0 0 DALLAS, TX 22 34 30 57 37 / 10 20 10 0 0 TERRELL, TX 23 34 27 57 34 / 10 20 10 0 0 CORSICANA, TX 24 34 30 60 38 / 10 30 10 0 0 TEMPLE, TX 24 35 29 65 38 / 20 30 10 0 0 MINERAL WELLS, TX 19 37 26 60 31 / 10 20 10 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 5 AM TO 3 PM CST FRIDAY FOR TXZ156>160-174-175. WINTER WEATHER ADVISORY FROM 9 AM TO 6 PM CST FRIDAY FOR TXZ122- 135-146>148-161-162. && $$ /30
AREA FORECAST DISCUSSION
NWS SEATTLE WA
530 PM PST SAT FEB 8 2014 .SYNOPSIS...A WEATHER SYSTEM WILL BRING SOME SNOW TO WESTERN WASHINGTON TONIGHT. THE AIR WILL WARM OVER WESTERN WASHINGTON SUNDAY AND SUNDAY NIGHT. A MILD WET WEATHER REGIME WILL BE IN PLACE THROUGH NEXT WEEK. && .SHORT TERM...UPDATE...A BAND OF LIGHT TO MODERATE SNOW HAS SHIFTED NORTHWARD INTO GRAYS HARBOR COUNTY. RADAR AND THE RUC13 MODEL SHOW 1-3 INCH ACCUMULATIONS MAKING IT NORTHWARD TO THE HOOD CANAL AREA AND TO ABOUT THE PIERCE-KING COUNTY LINE. A WINTER WEATHER ADVISORY WAS ISSUED FOR THE TACOMA AREA...THE HOOD CANAL AREA...THE LOWER CHEHALIS VALLEY...AND THE CENTRAL WASHINGTON COAST UNTIL 4 AM AS A RESULT. AT THIS TIME IT APPEARS THAT VERY STRONG EASTERLY PRESSURE GRADIENTS WILL KEEP THE HEAVIER SNOW FROM MOVING INTO KING OR SNOHOMISH COUNTIES...SO EXPECT LESS THAN AN INCH AT MOST THERE. WILL BE MONITORING THE SOUTHERN PART OF THE EAST PUGET SOUND LOWLANDS FOR THE THREAT OF ADVISORY LEVEL ACCUMULATIONS THIS EVENING...BUT THE EASTERLY FLOW SHOULD CUT BACK AMOUNTS. ALBRECHT FROM THE AFTERNOON SHORT TERM DISCUSSION...A WEATHER SYSTEM IS MOVING INTO WRN WA THIS AFTERNOON. SATELLITE IMAGERY SHOWS DEVELOPMENT WITH CLOUD TOPS COOLING AND MANY LOCATIONS IN WESTERN WILL FINALLY SEE SOME SNOWFALL TONIGHT. AT 3PM THE SEA-YKM GRADIENT IS ARND -9MB AND THE OLM-BLI GRADIENT IS ARND -4MB SO I DO NOT HAVE A GREAT DEAL OF SNOWFALL IN THE FORECAST AND ONLY HAVE A CHANCE IN THE NORTH...BUT OVERNIGHT THE GRADIENTS WILL GIVE OUT AND THE WARM ADVECTION AND MOISTURE WILL FINALLY OVERWHELM THE LOW LEVEL DRY AIR. AT 3PM SNOW IS FALLING AROUND TOLEDO AND SHOULD ARRIVE BY EARLY THIS EVENING IN THE SOUTH SOUND. SNOW FALLING INTO THIS AIR MASS WILL SEE A GOOD EVAPORATIVE COOLING/DEW POINT COOLING EFFECT...DEWPOINTS THIS AFTERNOON AVERAGE AROUND 20 DEGREES...LOWER IN THE NORTH. ON SUNDAY IT WILL WARM UP AND AROUND SUNDAY AFTERNOON OR EVENING ANOTHER SURGE OF WARMER AIR WILL TAKE 850MB TEMPS OUT OF THE RANGE WHERE SNOW IS A CONCERN AT ALL IN THE LOWLANDS. I DO NOT SEE MUCH TROUBLE SCOURING OUT THE LOW LEVEL COLD AIR IN WESTERN WA...EXCEPT FOR THE APPROACHES TO THE CASCADE PASSES. WET MILD WEATHER IS ON TAP FOR ALL OF NEXT WEEK AND IT IS LIKELY TO BE BREEZY AT TIMES. .LONG TERM...PERIODS OF RAIN AND BREEZY WEATHER ARE ON TAP FOR THE LOWLANDS THROUGH NEXT WEEK. FOR THE MOUNTAINS THE SNOW LEVEL WILL BE UP AND DOWN...BUT IT OUGHT TO AVERAGE AROUND 3000 FEET. A LOOK AT THE LATEST 18Z GFS DOES NOT SHOW ANY WINDSTORMS. THE STRONGEST GRADIENT I SEE IN THE 12Z ECMWF IS ASSOCIATED WITH A FRONTAL WAVE THAT MOVES INTO WESTERN OREGON WEDNESDAY NIGHT SO IF THAT WAVE WERE STRONGER AND A BIT FARTHER NORTH THAT MIGHT BE AN INTERESTING STORM BUT THE GFS IS MUCH WEAKER WITH THAT FRONTAL WAVE AND TIMING ANY SHORTWAVES AND FRONTS IS NOT POSSIBLE AT THIS LEAD TIME. && .HYDROLOGY...RIVER FLOODING IS NOT EXPECTED FOR THE NEXT 7 DAYS. && .AVIATION...MODERATE WESTERLY FLOW ALOFT WITH LIGHT TO MODERATE LOW LEVEL NE FLOW. A 1010 MB SURFACE LOW WILL TRACK INTO THE CENTRAL/N OREGON COAST THIS EVENING...THEN DISSIPATE. DEEP MOISTURE WILL SPREAD N INTO THE SRN HALF OF WRN WA THIS EVENING. HIGH LEVEL MOISTURE N PORTION. LIGHT SNOW WILL DEVELOP OVER SW WA THIS EVENING...REACHING KHQM AND KOLM 03-05Z...THEN REACHING KSEA/KBFI AFTER 06Z. ACCUMULATIONS OF 1-2 INCHES FROM KHQM TO KOLM SWD AND A TRACE TO ONE HALF INCH POSSIBLE UP TO KSEA/KBFI BY SUNRISE SUNDAY MORNING. SCATTERED LIGHT SNOW SHOWERS CHANGING OVER TO RAIN SHOWERS SUNDAY AFTERNOON. VFR CIGS FROM KPAE NWD...AND MVFR DEVELOPING S OF KPAE TONIGHT/SUNDAY. KSEA...LATEST COMPUTER MODELS INDICATE LIGHT SNOW WILL DEVELOP AFTER 06Z AND CONTINUE AT TIMES THROUGH SUNRISE SUNDAY MORNING (A 60 PERCENT CHANCE). A TRACE TO ONE INCH OF SNOW IS POSSIBLE WITH TEMPERATURES NEAR OR JUST BELOW FREEZING AT THE SURFACE. A CHANCE OVER FROM SNOW SHOWERS TO RAIN SHOWERS IS EXPECTED SUNDAY AFTERNOON WITH TEMPERATURES RISING WELL ABOVE FREEZING. VFR CIGS WITH MID/ HIGH CLOUDS....THEN MVFR CIGS DEVELOP AFTER 06Z TONIGHT. NE WIND 6-12 KT BECOMING SE WIND 5-8 KT AFTER 16Z. DTM && .MARINE...HIGH PRES WILL REMAIN OVER BRITISH COLUMBIA AND E OF THE CASCADES TODAY. LOW LEVEL E-NE FLOW WILL CONTINUE TONIGHT AHEAD OF A WEAK WARM FRONT IS EXPECTED TO MOVE N ACROSS THE AREA SUNDAY MORNING. GALES ARE EXPECTED NEAR THE W ENTRANCE TO THE STRAIT WITH SMALL CRAFT ADVISORY COASTAL WATERS/CENTRAL STRAIT/ AND N INLAND WATERS. A STRONGER FRONTAL SYSTEM WILL IMPACT THE AREA ON MON. THIS WILL BE FOLLOWED BY AN EVEN STRONGER SYSTEM ON TUE. THE WEATHER PATTERN OVER THE PACIFIC NORTHWEST WILL BECOME MORE ACTIVE AND TYPICAL FOR THIS TIME OF THE YEAR THIS UPCOMING WEEK. DTM && .SEW WATCHES/WARNINGS/ADVISORIES... WA...WINTER WEATHER ADVISORY SOUTHWEST INTERIOR...TACOMA AREA... HOOD CANAL AREA...LOWER CHEHALIS VALLEY...AND CENTRAL COAST UNTIL 4 AM SUN. PZ...SMALL CRAFT ADVISORY MOST COASTAL WATERS...CENTRAL STRAIT OF JUAN DE FUCA...AND NORTH INLAND WATERS. GALE WARNING NORTH INNER COAST ZONE...AND WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA. && $$ WWW.WEATHER.GOV/SEATTLE FOR THE GRAPHICAL AFD...VISIT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
550 AM MST FRI FEB 7 2014 .SHORT TERM...(TODAY THROUGH SATURDAY NIGHT) ISSUED AT 544 AM MST FRI FEB 7 2014 BITTERLY COLD TEMPERATURES CONTINUE ACROSS MUCH OF THE NEBRASKA PANHANDLE THIS MORNING EXCEPT FOR IN THE NORTH PLATTE RIVER VALLEY WHERE TEMPS HAVE GENERALLY RISEN ABOVE ZERO. WILL LET THE WIND CHILL ADVISORY RUN ITS COURSE FOR MOST OF THE AREA EXCEPT FOR SCOTTS BLUFF AND MORRILL COUNTIES WHERE THE ADVISORY HAS BEEN CANCELLED DUE TO THE WARMER TEMPS. TEMPERATURES ACROSS SOUTHEAST WYOMING HAVE SEEN A STEADY AND WELCOME TREND UPWARD OVERNIGHT AS SOUTHWESTERLY WINDS REMAINED ON THE BREEZY SIDE ALONG AND WEST OF THE LARAMIE RANGE. TODAY WILL SEE FURTHER WARMING DUE TO THE DOWNSLOPE WINDS AND AS THE ARCTIC BOUNDARY CONTINUES TO RETREAT NORTHWARD IN RESPONSE TO ENERGETIC ZONAL FLOW ALOFT. LOOKING AT HIGHS IN THE 20S AND 30S. REGARDING THE WINDS...A SFC LOW WILL MOVE ACROSS WYOMING AND WILL STRENGTHEN THE GRADIENT LATE THIS MORNING. THIS SHOULD INDUCE STRONG AND GUSTY WINDS IN THE ARLINGTON AREA WITH 700 MB WINDS PROGGED TO BE AROUND 50 KTS THROUGH THIS TIME. THE HIGH WINDS SHOULD THEN SPREAD INTO THE BORDEAUX AREA AND THE SOUTHERN LARAMIE RANGE LATE THIS AFTERNOON THROUGH TONIGHT AS THE SFC LOW TREKS EASTWARD WITH STRONG SUBSIDENCE AND PRESSURE RISES EXPECTED IN ITS WAKE. WINDS OVERALL DO LOOK TO WEAKEN THROUGH THE MORNING...BUT GUIDANCE IS SHOWING 50 KT WINDS AT 700 MB TO PERSIST OVER THE SOUTHERN LARAMIE RANGE THROUGH THE MORNING. THEREFORE...HIGH WINDS MAY PERSIST IN THIS AREA THROUGH SUNRISE. A STRONGER JET AND SHORTWAVE WILL MOVE OVERHEAD FOR SATURDAY...WITH 700 MB WINDS PROGGED TO INCREASE TO AROUND 60 KTS BY THE AFTERNOON. SO...THINK HIGH WINDS WILL RETURN BY MID SATURDAY MORNING AND WILL CONTINUE THROUGH EARLY SUNDAY MORNING IN THESE AREAS. FELT IT REASONABLE TO JUST EXTEND THE CURRENT HIGH WIND WARNING TO ACCOUNT FOR THIS SECOND SURGE OF HIGH WINDS. THE ONE QUESTION THAT REMAINS TO BE ANSWERED IS JUST HOW STRONG WINDS AT THE BORDEAUX SITE WILL BECOME DURING THIS SECONDARY SURGE OF HIGH WINDS. THE ARCTIC BOUNDARY IS EXPECTED TO MOVE SOUTHWARD BACK INTO THE CWA ONCE AGAIN SATURDAY MORNING. IF THE BOUNDARY SURGES ALL THE WAY TO THE LARAMIE RANGE...DOUBT BORDEAUX WILL SEE THE STRONG WINDS AND THUS MAY BE ABLE TO CANCEL THE WARNING HERE EARLY. HOWEVER...IT SEEMS QUITE POSSIBLE THE STRONG DOWNSLOPE COMPONENT OF THE WINDS MAY JUST KEEP THE ARCTIC BOUNDARY AT BAY LONG ENOUGH FOR THE GAP WINDS TO IMPACT THE I-25 CORRIDOR NEAR BORDEAUX. THE OTHER MAIN STORY WILL BE THE SNOW POTENTIAL FOR TODAY AND SATURDAY ACROSS THE CWA. UPGRADED THE WINTER STORM WATCH TO A WARNING FOR THE SNOWY AND SIERRA MADRE RANGES AND STARTED IT AT NOON TODAY AS AN INITIAL JETLET WILL SLAM INTO THE WESTERN SLOPES AND LIKELY BRING A FEW INCHES OF SNOW TO THE MOUNTAINS THROUGH SUNSET. THEN AFTER A BRIEF BREAK...THE SECOND STRONGER JET WILL MOVE OVERHEAD AND WILL BRING MODERATE TO HEAVY SNOW AT TIMES THROUGH SUNDAY. WILL HAVE TO WATCH THE NEARBY LOWER ELEVATIONS CAREFULLY FOR SNOW ACCUMULATIONS AS WELL. THINKING 1 TO 2 INCHES IS POSSIBLE AT SARATOGA AND ARLINGTON TODAY WITH THE COMBINATION OF OROGRAPHIC FORCING AND THE SFC LOW MOVING ACROSS THE AREA...WITH CONTINUED LIGHT SNOW ON AND OFF THROUGH SATURDAY AS THE STRONGER JET MOVES OVERHEAD. BLOWING SNOW WILL DEFINITELY BE A CONCERN ESPECIALLY IN THE MOUNTAINS AND IF ARLINGTON RECEIVES THE EXPECTED SNOWFALL WITH POSSIBLE GUSTS UP TO 60 MPH. WITH THE STRONGER AND MORE ENERGETIC JET WILL COME A BETTER FETCH OF PACIFIC MOISTURE AS WELL. STILL LOOKS TO SEE INCREASING SNOW POTENTIAL ALONG THE NORTHERN LARAMIE EASTWARD INTO THE NEBRASKA PANHANDLE WITH THE COMBINATION OF UPSLOPE FLOW AND INCREASING FRONTOGENESIS ON SATURDAY. HOWEVER...THERE IS STILL SOME UNCERTAINTY WITH WHERE THE AXIS OF FRONTOGENESIS SETS UP ON SATURDAY. THE GFS SHOWS THE MAIN BAND OF FORCING FURTHER SOUTH WITHIN THE CWA WHILE THE NAM AND ECMWF SHIFT IT NORTH THROUGH THE AFTERNOON AND EVENING. REGARDLESS...THERE WILL BE A PERIOD OF GOOD JET DYNAMICS AND LIFT FROM THE FRONTOGENESIS BAND SATURDAY AFTERNOON AND EVENING THAT WILL PRODUCE WIDESPREAD LIGHT TO MODERATE SNOW ACROSS THE NORTHERN TIER OF ZONES. EXPECT ENHANCED SNOW AMOUNTS WHEREVER THE FRONTOGENESIS BAND SETS UP BUT ITS TOUGH TO TELL AT THIS POINT WHERE THAT WILL BE. WOULD FAVOR THE FURTHER NORTHWARD POSITION INITIALLY DUE TO THE STRONG WESTERLY MIDLEVEL WINDS IN PLACE. SO...STILL THINKING 3 TO 6 INCHES FOR THE LOWER ELEVATIONS...WITH 6 TO 10 IN THE NORTHERN LARAMIE RANGE WITH THIS EVENT. AS A SFC HIGH DIVES SOUTH INTO THE HIGH PLAINS OVERNIGHT...EXPECT THE SNOW BAND TO SHIFT SOUTH INTO THE SOUTHERN ZONES. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 544 AM MST FRI FEB 7 2014 ACTIVE WEATHER TO CONTINUE IN THE LONG TERM WITH SNOW CHANCES/LOCATIONS INITIALLY...THEN WINDS LATER NEXT WEEK BEING THE FORECAST CHALLENGES. STARTING OFF SUNDAY...BOTH THE GFS AND ECMWF SHOWING AN ARCTIC BOUNDARY SUNDAY MORNING LAYING ALONG A LINE FROM SIDNEY TO DOUGLAS SUNDAY MORNING AND BOTH ARE VERY SIMILAR WITH QPF LOCATION AND OUTPUT. GFS A LITTLE MORE BULLISH ON QPF THOUGH. NAM IS WAY TOO DRY AND IS CONSIDERED THE OUTLIER ON THIS EVENT. IT WILL STILL BE WINDY OUT WEST AS THE GFS KEEPS 700MB WINDS 50KTS OR GREATER THROUGH THE AFTERNOON HOURS. KEPT BLOWING SNOW GOING OUT THAT WAY. THIS BOUNDARY THEN LAYS UP ALONG THE LARAMIE RANGE SUNDAY EVENING INTO MONDAY. BY SUNDAY EVENING...WE HAVE ANOTHER JET MAX MOVING INTO SOUTHWEST WYOMING WITH THE CWFA IN A FAVORABLE LEFT FRONT QUADRANT OF THE JET MAX. 700MB TEMPERATURES -10 TO -14C. PRETTY MOIST PROFILES SEEN ON GFS SOUNDINGS FOR VARIOUS POINTS IN THE CWFA AS WELL...WITH MOISTURE UP THROUGH 300MBS. FAIRLY UNSTABLE THROUGH THE -10 TO -20C LAYER WITH 8-10 MICROBAR UPWARD VERTICAL VELOCITIES HERE AT CHEYENNE. WITH SNOW RATIOS 20:1 OR HIGHER IN THIS SETUP...WE COULD SEE A PRETTY GOOD SNOW EVENT BEING WIDESPREAD SUNDAY AFTERNOON AND EVENING. WILL NEED TO MONITOR THIS CLOSELY. DAY SHIFT WILL NEED TO CONSIDER A WINTER STORM WATCH FOR A LARGE PORTION OF THE CWFA. WITH THIS MORNINGS RUN...IT LOOKS LIKE THE SOUTHERN PANHANDLE AND MAYBE THE I-80 CORRIDOR THROUGH LARAMIE AND I-25 CORRIDOR UP TO WHEATLAND. FRONTAL BOUNDARY THEN BEGINS TO LIFT NORTHEAST MONDAY MORNING SLOWLY AS WESTERLY WINDS RETURN TO THE AREA. BY MONDAY AFTERNOON...IT LOOKS TO CLEAR THE PANHANDLE TO THE EAST WITH SNOW ENDING ACROSS MUCH OF THE CWFA OUTSIDE OF THE SNOWY AND SIERRA MADRE RANGES. 700MB WINDS REALLY BEGIN RAMPING UP TUESDAY AFTERNOON...INCREASING TO 55KTS OVER SOUTHERN WYOMING...INCREASING TO 65KTS AFTER 06Z WEDNESDAY. WINDS STAY STRONG THROUGH THE END OF THE WEEK SO WE WILL BE DEALING WITH WIND HEADLINES FROM TUESDAY ON THROUGH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 544 AM MST FRI FEB 7 2014 DETERIORATING CONDITIONS AT KRWL AND KLAR LATER THIS MORNING AND AFTERNOON AS WINDS INCREASING AND SNOW BECOMES MORE WIDESPREAD. KRWL WILL SEE WINDS GUSTING IN THE 30 TO 35KT RANGE WHICH WILL CREATE THE BLOWING SNOW. KLAR A LITTLE LATER FOR THE WINDS TO COME UP. HRRR HAS BEEN SHOWING THIS OVER SEVERAL MODEL RUNS. VFR EAST OF THE LARAMIE RANGE NEXT 24 HOURS. && .FIRE WEATHER... ISSUED AT 544 AM MST FRI FEB 7 2014 NO FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. WESTERLY WINDS WILL INCREASE OVER SOUTHEAST WY THIS AFTERNOON...AND WINDY CONDITIONS WILL PERSIST ALONG AND WEST OF THE LARAMIE RANGE THROUGH THE WEEKEND. WIDESPREAD LIGHT TO MODERATE SNOW WILL BE POSSIBLE ON SATURDAY AND SUNDAY ACROSS THE REGION...WITH SNOW BEGINNING IN THE MOUNTAINS THIS AFTERNOON. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER STORM WARNING FROM NOON TODAY TO 5 PM MST SUNDAY FOR WYZ112-114. HIGH WIND WARNING FROM 9 AM THIS MORNING TO 5 AM MST SUNDAY FOR WYZ110. HIGH WIND WARNING FROM 3 PM THIS AFTERNOON TO 5 AM MST SUNDAY FOR WYZ106-116. NE...WIND CHILL ADVISORY UNTIL 9 AM MST THIS MORNING FOR NEZ002-003- 020-054-055-095-096. && $$ SHORT TERM...RJM LONG TERM...CLAYCOMB AVIATION...CLAYCOMB FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
358 AM CST Sun Feb 9 2014 ...Updated long term section... .SHORT TERM...(Today and tonight) ISSUED AT 343 AM CST SUN FEB 9 2014 Areas of locally dense freezing fog that developed over parts of central and western Kansas after sunset were propagating southwest behind the front into the far southwest part of the state early this morning. The last few runs of the RUC and HRRR visibility progs have been pretty consistent in moving the fog south and west into southeast Colorado and the Oklahoma/Texas panhandles by 12z. This looks reasonable given the dry air advection that is currently ongoing from north central into southwest Kansas. The dense fog advisory goes until 12z and will let it ride but continue to monitor for any areal or temporal extensions. Per SREF analysis and water vapor imagery, the first upper speed max was currently moving into the upper Mississippi Valley early this morning. The subsequent speed maxes will move out along the Kansas Nebraska border today and out over Kansas tonight. Associated mid level frontogenetic forcing will move out across Nebraska and far northern Kansas this morning and over Kansas tonight. Regional radar mosaic shows light snow already moving out of Wyoming into the Nebraska Panhandle and this will continue eastward across northern Kansas and Nebraska today. The current forecast has chance pops for light snow along the I-70 corridor today. Think any measurable snow will be north of the Dodge City forecast area today. The system moving out tonight should bring some accumulating snow to west central and parts of southwest and south central Kansas tonight. The models have been consistent with this so have increased pops well into the likely category tonight. The NAM is showing a swath of 1-2 inch snowfall generally north of Highway 50 tonight. Have increased snowfall amounts a little but for now think we will not see enough to warrant a winter weather advisory. Temperatures will not rise much, if at all, today given the ongoing cold air advection. Temperatures tonight should fall well down into the single digits above zero with a few low teens possible around Elkhart and Liberal. .LONG TERM...(Monday through Saturday) ISSUED AT 355 AM CST SUN FEB 9 2014 A weak shortwave trough will move through the Central Rockies along the zonal flow late Sunday. This shortwave will then move through Kansas on Monday. Convergence and mid level moisture will increase as this feature approaches. Mostly cloudy skies are anticipated throughout the day Monday with light to moderate snow showers. Precipitation chances end from west to east Monday evening into Monday night. Snow totals remain around 1 to 2 inches across the area. However, a few areas across west central and south central Kansas could see over 2 inches by the time the system exits the area. Surrounding offices and DDC have decided to not go with a winter weather advisory at this time and have the day shift see what the next model run suggests. Cloudy skies should continue Monday night with some clearing possible across west central Kansas towards sunrise. Winds will generally be from a northeasterly direction Monday as high pressure builds into the Plains. With the cloud cover and shot of cold air advection across the area, temperatures Monday are not expected to increase much from the morning lows. Highs Monday are forecasted to range from the lower teens across central Kansas to lower 20s across far southwestern Kansas. Lows Tuesday morning are expected to range from the negative single digits across central Kansas to around 10 degrees across far southwestern Kansas. However, if more clearing occurs overnight, temperatures could end up lower than what the current forecast depicts. The dome of high pressure moves east of the area on Tuesday shifting winds to the southwest. A few low level clouds may continue in the morning across south central Kansas Tuesday morning. Otherwise expect partly cloudy skies and dry conditions. The Central High Plains will then be stuck in between an upper level ridge across the western US and an upper level long wave trough across the eastern United states throughout the remainder of the forecast period. A few weak shortwaves are progged to move north of the area, but do not look to bring any precipitation across southwest Kansas at this time. Only a few clouds are expected to be observed throughout this period with dry conditions. Winds will generally be from the west but shift slightly to the north or south as the aforementioned shortwaves move north of southwest Kansas. We will finally begin the slow warming up process Tuesday through Saturday, however the snowpack across much of the region will need to be knocked out quite a bit before we realize maximum potential based on typical downslope mix-down scenarios. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) ISSUED AT 1140 PM CST SAT FEB 8 2014 IFR to LIFR ceilings will continue at the TAF sites in southwest and central Kansas through the overnight hours. Visibilities will stay in the 1/4 to 1/2 mile range at Garden City and Dodge City with visibilities remaining around 4-6 miles at Hays through the overnight hours. Conditions should improve somewhat into the MVFR category by mid to late Sunday morning. && .PRELIMINARY POINT TEMPS/POPS... DDC 19 8 15 3 / 20 60 50 30 GCK 19 8 17 5 / 30 60 50 20 EHA 24 12 23 11 / 20 30 30 20 LBL 23 12 20 7 / 20 40 40 20 HYS 17 5 12 -1 / 30 60 40 20 P28 23 9 16 3 / 30 60 50 30 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY until 6 AM CST /5 AM MST/ early this morning FOR KSZ043-044-061>064-074>078-084>088. && $$ SHORT TERM...Gerard LONG TERM...Hovorka_42 AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
345 AM CST Sun Feb 9 2014 ...Updated synopsis and short term discussion... .SYNOPSIS... ISSUED AT 343 AM CST SUN FEB 9 2014 This evenings upper air analysis showed strong west northwest mid to upper level flow extending from the Pacific Northwest into the northern and central Plains and Ohio Valley. The 250 millibar analysis showed 120+ knot speed maxes over Wyoming, and moving onshore into the Pacific Northwest. Another speed max was approaching the west coast. The 850-700 millibar baroclinic zone extended from Wyoming to along the Kansas/Nebraska border. At the surface, a reinforcing shot of arctic air was pushing south through Nebraska early this morning behind a cold front which has pushed south through all of western Kansas. && .SHORT TERM...(Today and tonight) ISSUED AT 343 AM CST SUN FEB 9 2014 Areas of locally dense freezing fog that developed over parts of central and western Kansas after sunset were propagating southwest behind the front into the far southwest part of the state early this morning. The last few runs of the RUC and HRRR visibility progs have been pretty consistent in moving the fog south and west into southeast Colorado and the Oklahoma/Texas panhandles by 12z. This looks reasonable given the dry air advection that is currently ongoing from north central into southwest Kansas. The dense fog advisory goes until 12z and will let it ride but continue to monitor for any areal or temporal extensions. Per SREF analysis and water vapor imagery, the first upper speed max was currently moving into the upper Mississippi Valley early this morning. The subsequent speed maxes will move out along the Kansas Nebraska border today and out over Kansas tonight. Associated mid level frontogenetic forcing will move out across Nebraska and far northern Kansas this morning and over Kansas tonight. Regional radar mosaic shows light snow already moving out of Wyoming into the Nebraska Panhandle and this will continue eastward across northern Kansas and Nebraska today. The current forecast has chance pops for light snow along the I-70 corridor today. Think any measurable snow will be north of the Dodge City forecast area today. The system moving out tonight should bring some accumulating snow to west central and parts of southwest and south central Kansas tonight. The models have been consistent with this so have increased pops well into the likely category tonight. The NAM is showing a swath of 1-2 inch snowfall generally north of Highway 50 tonight. Have increased snowfall amounts a little but for now think we will not see enough to warrant a winter weather advisory. Temperatures will not rise much, if at all, today given the ongoing cold air advection. Temperatures tonight should fall well down into the single digits above zero with a few low teens possible around Elkhart and Liberal. .LONG TERM...(Sunday night through Saturday) ISSUED AT 247 PM CST SAT FEB 8 2014 Sunday Night through Tuesday: One last renewed arctic air shot will affect western Kansas during this time frame...and along with it will be an increased chance for some light snow. A shortwave trough will be approaching the Colorado Rockies along the zonal flow pattern late Sunday. Deformation and convergence will slowly increase along a pre-existing baroclinic zone around 700mb with the lower-mid troposphere moistening overnight Sunday Night. Using primarily the ECMWF as guidance in the forecast, the mid-level potential vorticity (PV) anomaly will move from Utah into southern Colorado early Monday. Ahead of it, 700mb frontogenesis will increase, despite the overall westerly component to the flow at this level. On the mesoscale, there will most likely be subtleties within the broad baroclinic zone, but these little nuances are impossible to predict a couple days out, so the forecast will reflect a general ramp up in POPs late Sunday Night with a plateau of around 50 POPs for much of the day Monday before decreasing later in the afternoon once the main body of the disturbance moves east-southeast of the southwest Kansas region. As far as snow totals go, we are looking at roughly an 18-hr period of total accumulations in the 1 to 2 inch range. Given the clouds and precipitation Monday and the core of the fresh arctic airmass amidst the region, temperatures will not rise much at all. We have lowered the maximum temperature 4 or 5 degrees for most locations across the forecast area, in line with the ECMWF 2-meter temperatures. Monday Night should prove to be very cold with a fresh coat of snow, however questions about how fast clouds will clear out will have huge implication on overnight low. We would likely see widespread temperatures at or below zero, especially north of the Arkansas River, should low clouds clear out by midnight or so. The surface high will move off to the east Tuesday, however the surface flow will still be influence by the high which will be recirculating cold trajectories despite a south or south-southeast wind. We have lowered the high forecast across the eastern half of the forecast area Tuesday by a few degrees, and this may not even be enough. Meanwhile, out toward the Colorado border (especially Elkhart), temperatures may approach 40 by late afternoon. Rest of the work-week: We will finally begin the slow warming up process, however the snowpack across much of the region will need to be knocked out quite a bit before we realize maximum potential based on typical downslope mix-down scenarios. The Allblend guidance was left untouched for this forecast, however the general feeling is that the warm-up may be a bit too ambitious by the guidance and feel these daytime highs will be lowered in subsequent updates along/east of Highway 283 and especially toward central Kansas. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) ISSUED AT 1140 PM CST SAT FEB 8 2014 IFR to LIFR ceilings will continue at the TAF sites in southwest and central Kansas through the overnight hours. Visibilities will stay in the 1/4 to 1/2 mile range at Garden City and Dodge City with visibilities remaining around 4-6 miles at Hays through the overnight hours. Conditions should improve somewhat into the MVFR category by mid to late Sunday morning. && .PRELIMINARY POINT TEMPS/POPS... DDC 19 8 15 3 / 20 60 50 30 GCK 19 8 17 5 / 30 60 50 20 EHA 24 12 23 11 / 20 30 30 20 LBL 23 12 20 7 / 20 40 40 20 HYS 17 5 12 -1 / 30 60 40 20 P28 23 9 16 3 / 30 60 50 30 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY until 6 AM CST /5 AM MST/ early this morning FOR KSZ043-044-061>064-074>078-084>088. && $$ SYNOPSIS...Gerard SHORT TERM...Gerard LONG TERM...Umscheid AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS CARIBOU ME
331 AM EST SUN FEB 9 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF TO THE EAST TODAY WHILE LOW PRESSURE MOVES IN FROM NEW YORK STATE TONIGHT. THIS LOW PRESSURE WILL TRACK SOUTHEAST OF THE REGION ON MONDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION THROUGH MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... MAIN CHALLENGE WILL BE TEMPERATURES, LOW CLOUDS THIS MORNING ACROSS THE NORTH AND PRECIP CHANCES. A LLVL INVERSION HAS SETUP OVER THE REGION W/TEMPERATURES REALLY DROPPING OFF IN THE VALLEYS AND ALONG THE RIVERS. TEMPERATURES IN THESE AREAS COULD BOTTOM OUT IN A RANGE OF 15 TO 20 BELOW BY 7 AM THIS MORNING ESPECIALLY ACROSS NORTHERN AND WESTERN AREAS. MID AND HIGH CLOUDS ACROSS THE DOWNEAST AND SOUTHERN MAINE HAVE KEPT TEMPERATURES UP SOME. THERE COULD BE SOME PATCHY FREEZING FOG OR STRATUS ESPECIALLY IN THE LOW LYING AREAS RIGHT AROUND SUNRISE AS IS SHOWN BY THE LATEST HRRR AND THE RAP. THE HRRR HAS BEEN CONSISTENT IN SHOWING THIS LLVL MOISTURE. THIS MOISTURE SHOULD BURN OFF AND LIFT AFTER SUNRISE W/THE INVERSION BREAKING. TEMPERATURES WILL WARM TODAY BUT STILL REMAIN BELOW NORMAL FOR EARLY FEBRUARY. DECIDED TO PUSH BACK THE ARRIVAL OF SNOW UNTIL THIS EVENING. THE LATEST RAP MODEL WAS HANDLING THE PRECIP SHIELD WELL PER 06Z ANALYSIS. THE LATEST MODEL SOUNDINGS INCLUDING THE GFS AND NAM SHOW THE COLUMN MOISTENING UP THROUGH 500MBS THIS EVENING INTO THE OVERNIGHT HRS. THIS MOISTURE WILL BE IN RESPONSE TO LOW PRES MOVING ACROSS THE GULF OF MAINE FROM NYS. THIS MOISTURE IS SHOWN TO MAKE ITS WAY UP INTO THE CROWN OF MAINE ESPECIALLY W/THE GFS. THE BEST LIFT AND ANY FRONTOGENETICAL FORCING WILL BE FROM THE CENTRAL HIGHLANDS(SOUTHERN PISCATAQUIS COUNTY) ALL TO WAY TO THE COAST. SNOW RATIOS WILL MAKE SNOWFALL A CHALLENGE AS THEY WILL BE ON THE ORDER OF 18-22:1 & QPF LESS THAN 0.25 INCHES. ATTM, THE DECISION HERE WAS TO STAY W/THE DAYCREW`S ASSESSMENT OF THE BEST SNOWFALL WILL BE ACROSS THE DOWNEAST AND ESPECIALLY THE COAST WHERE TOTALS BY MONDAY COULD HIT 3-4 INCHES. DECIDED ON NO ADVISORY ATTM SINCE THIS EVENT WILL STRETCH INTO MONDAY. SINCE TEMPERATURES WILL BE HELD UP AFTER FALLING OFF THIS EVENING ESPECIALLY ACROSS NORTHERN AREAS. READINGS ACROSS THE FAR NORTH SUCH AS THE ST. JOHN VALLEY COULD DROP BACK TO BELOW ZERO BEFORE LEVELING OFF W/THE INCREASING CLOUDS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... A WEAK AREA OF LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE EARLY MONDAY. LIGHT SNOW WILL TAPER TO SNOW SHOWERS EARLY MONDAY AS THE LOW MOVES EAST. SNOW ACCUMULATIONS THROUGH MONDAY WILL RANGE FROM 1 TO 3 INCHES ACROSS DOWNEAST MAINE WITH LESSER AMOUNTS ACROSS THE REMAINDER OF NORTHERN MAINE. HIGH PRESSURE WILL THEN BEGIN TO BUILD EAST ACROSS THE REGION MONDAY NIGHT THROUGH TUESDAY. EXPECT DECREASING CLOUDS MONDAY NIGHT AND PARTLY/MOSTLY SUNNY SKIES TUESDAY. TEMPERATURES WILL BE BELOW NORMAL BOTH MONDAY AND TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE WILL BUILD EAST TUESDAY NIGHT THROUGH WEDNESDAY. THE HIGH WILL THE MOVE EAST WEDNESDAY NIGHT. EXPECT MAINLY CLEAR SKIES TUESDAY NIGHT AND MOSTLY SUNNY SKIES ON WEDNESDAY. THE HIGH WILL MOVE EAST WEDNESDAY NIGHT AND THURSDAY. A LOT OF UNCERTAINTY STILL EXISTS WITH REGARD TO THE FORECAST FOR THE LATTER HALF OF THE WEEK. LATEST OPERATIONAL RUN OF THE GFS SHOWS LOW PRESSURE TRACKING NORTHEAST FROM THE SOUTHEASTERN U.S. THURSDAY AND PASSING WELL TO THE SOUTH OF NOVA SCOTIA THURSDAY NIGHT THROUGH FRIDAY. THE LATEST EC TRACKS THE LOW NORTHEAST ALONG THE EASTERN SEABOARD LATER WEDNESDAY NIGHT AND UP ALONG THE MAINE COAST LATE THURSDAY AND NORTHEAST THROUGH THE MARITIMES ON FRIDAY. THE EC IS BY FAR AN OUTLIER COMPARED TO OTHER MODEL GUIDANCE. THAT BEING SAID...HAVE NOT DEVIATED FROM SUPERBLEND POPS THROUGH THE EXTENDED PERIOD. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... NEAR TERM: VFR ATTM TODAY. THERE COULD BE BRIEF MVFR/IFR CONDITIONS MAINLY FOR THE NORTHERN TERMINALS SUCH KQPI AND KFVE. CONDITIONS WILL DETERIORATE ACROSS THE DOWNEAST AND THE COAST LATER TONIGHT W/KBGR AND KBHB SEEING MVFR AND PERHAPS IFR BY MONDAY MORNING. SHORT TERM: MVFR/IFR POSSIBLE IN -SN EARLY MONDAY...THEN MAINLY VFR THROUGH WEDNESDAY NIGHT. MVFR/IFR POSSIBLE IN PRECIPITATION THURSDAY BUT CONFIDENCE IS LOW. && .MARINE... NEAR TERM: NO HEADLINES EXPECTED. WINDS WILL AVERAGE 10-15 KTS W/SEAS RUNNING 2-3 FT RIGHT INTO TONIGHT. CONTINUED THE MENTION OF FREEZING SPRAY THIS MORNING AND AGAIN TONIGHT. SHORT TERM: WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH MOST OF THE LONG TERM. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT/DUDA MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
107 AM EST SUN FEB 9 2014 .SYNOPSIS... HIGH PRESSURE WILL CROSS THE REGION OVERNIGHT. LOW PRESSURE WILL TRACK SOUTHEAST OF THE REGION SUNDAY NIGHT THROUGH MONDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION THROUGH MID WEEK. && .NEAR TERM /THROUGH SUNDAY NIGHT/... 107 AM UPDATE...ADJUSTMENTS WERE NEEDED TO OVERNIGHT TEMPERATURES AS READINGS ESPECIALLY IN THE VALLEYS ARE DROPPING OFF FASTER THAN PREVIOUSLY FCST. DECIDED TO DROP THE OVERNIGHT MINS A CATEGORY FROM THE PREVIOUS FCST WHICH PUTS THE VALLEYS OF NORTHERN MAINE IN A RANGE OF 15 TO 20 BELOW BY 12Z. MID/HIGH CLOUDS MOVING INTO THE DOWNEAST AND COAST WERE HOLDING TEMPERATURES UP A FEW DEGREES, BUT STILL EXPECTING TEMPERATURES TO FALL BACK INTO THE SINGLE NUMBERS AND PERHAPS BELOW ZERO IN THE LOW LYING AREAS. RAP AND HRRR SHOWING SOME LLVL MOISTURE SETTING UP EARLY THIS MORNING ESPECIALLY ALONG THE RIVERS AND VALLEYS IN THE FORM OF FOG OR STRATUS. WILL CONTINUE TO MONITOR THIS THROUGH EARLY MORNING. MOST OF THE CLDNSS OVR SRN PTNS OF THE FA SHOULD THEN EXIT BY ERLY SUN AFTN...BEFORE CLDS INCREASE AGAIN FOR WRN AND SRN PTNS OF THE FA BY SUN EVE AHEAD OF A MORE SYNOPTIC SCALE S/WV FROM THE LOWER GREAT LKS. IT APPEARS...THAT ANY LGT SN WITH THIS SYSTEM FOR OUR FA WILL HOLD OFF UNTIL SUN NGT. OTHERWISE...AFT CHILLY MORN LOWS...SPCLY ACROSS THE N...TEMPS SHOULD THEN RECOVER TO SIMILAR HI TEMPS SUN AS THIS AFTN. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... LOW PRESSURE WILL TRACK SOUTHEAST OF THE GULF OF MAINE SUNDAY NIGHT INTO MONDAY. THE LOW WILL BRING LIGHT SNOW TO THE REGION SUNDAY NIGHT INTO EARLY MONDAY...TAPERING TO SNOW SHOWERS MONDAY AFTERNOON. THE STEADIEST SNOWS SUNDAY NIGHT INTO EARLY MONDAY WILL OCCUR ACROSS DOWNEAST PORTIONS OF THE THE FORECAST AREA WHERE 1 TO 3 INCHES OF TOTAL ACCUMULATION IS EXPECTED. LESSER SNOWS WILL OCCUR NORTHWARD ACROSS THE REMAINDER OF THE FORECAST AREA. HIGH PRESSURE WILL THEN BUILD EAST TOWARD THE REGION MONDAY NIGHT THROUGH TUESDAY. CLOUD COVER WILL DECREASE ACROSS THE REGION MONDAY NIGHT. PARTLY SUNNY SKIES ARE EXPECTED ACROSS NORTHERN AREAS TUESDAY WITH MOSTLY SUNNY SKIES DOWNEAST. TEMPERATURES WILL BE AT BELOW NORMAL LEVELS MONDAY/TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AT THE START OF THE PERIOD THE MODELS ARE IN GOOD AGREEMENT. A HIGH PRESSURE RIDGE WILL DOMINATE THE WEATHER ACROSS THE REGION AT THE START OF THE PERIOD. THE EXTENDED MODELS DIFFER A BIT ON PLACEMENT OF THE NEXT SYSTEMS THE FIRST LOW IS EITHER IN THE ERN GULF OF MEXICO OR ALONG THE ATLANTIC COAST OF GEORGIA. THE SECOND LOW MOVING EAST ACROSS SRN CANADA. THE SRN LOW WILL SLOWLY MOVE UP THE EAST COAST. THE ECMWF MOVES THE LOW INTO THE SRN GULF OF MAINE THUR AFTERNOON. THE GFS AND GEM THOUGH THEY DO NOT SHOW A CLOSED LOW...INDICATE THAT SOMETHING WILL BE IN THE SAME AREA AS THE ECMWF. AT THIS TIME THE RIDGE WILL HAVE BUILD EAST OF THE AREA...THE LOW AND ITS ASSOCIATED TROUGH MOVING EAST ACROSS SRN CANADA WILL BE EXTENDED NE TO SW ACROSS QUEBEC...THROUGH THE CENTRAL GREAT LAKES INTO NRN IL. THUR EVNG...THE ECMWF LOW MOVES NE INTO SW NOVA SCOTIA...THE GFS AND GEM CONTINUE TO INDICATE SOMETHING IN THE SAME AREA...THE TROUGH MOVES SE AND THE LOW OVER NOVA SCOTIA AND THE TROUGH BEGIN TO INTERACT ACROSS MAINE AND NEW BRUNSWICK. FRI MRNG THE GFS...ECMWF...AND GEM DIFFER ON THEIR RESPECTIVE SOLUTIONS. THE GFS MOVES THE TROUGH SOUTH TO THE GULF OF MAINE...WRAPS THE ENERGY FROM THE CURRENT LOW INTO A NEW ONE OVER BAR HARBOR...THE ECMWF ALSO SHOWS A MUCH WEAKER LOW OVR NRN PA...AS WELL AS MAINTAINING THE ORIGINAL LOW NOW WELL EAST OF THE AREA ENTERING THE WRN CANADIAN MARITIMES. THE GEM MAINTAINS THE ORIGINAL LOW MOVES IT INTO THE MARITIMES...ALSO MAINTAINS THE TROUGH ACROSS NRN MAINE...BACK ACROSS THE NRN GREAT LAKES TO A NEW LOW OVER LAKE HURON. BY SAT MRNG THE LOW MOVES EAST INTO THE MARITIMES...A WEAK HIGH PRESSURE RIDGE BUILDS ACROSS THE REGION...A LOW PRESSURE OVER THE CENTRAL GREAT LAKES WITH A COLD FRONT EXTENDING SOUTH THROUGH LA...INTO THE GULF OF MEXICO. SAT EVEN THE LOW MOVES EAST INTO CENTRAL QUEBEC...THE FRONT INTO WRN MAINE...AND BY THE END OF THE PERIOD...THE LOW MOVES INTO ERN QUEBEC...THE FRONT MOVES EAST INTO WRN NEW BRUNSWICK. LOADED THE SUPERBLEND FOR GRIDS. OVRNGT WED THRU THURS LOADED TWO SUPERBLEND AND 1 ECMWF FOR POPS..THIS WILL GIVE A BIT MORE WEIGHT TO THE GFS SOLUTION THROUGH THAT TIME FRAME WITHOUT A COMPLETE CHANGE FROM THE SUPERBLEND SOLUTION. NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. ADDED 20 TO WINDS FOR GUSTS OVER LAND 30 PERCENT OVER THE WATERS. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... NEAR TERM: MSLY VFR XPCTD THROUGH SUNDAY. THE HRRR HAS AT TIMES BEEN TRYING TO DEVELOP LOW STRATUS ALONG AND NEAR THE AROOSTOOK RIVER TOWARD MORNING...BUT CONFIDENCE IS VERY LOW AND WILL MAINTAIN A VFR FCST ATTM AT THE TERMINALS AND CONTINUE TO CLOSELY MONITOR. SHORT TERM: OCCASIONAL MVFR CONDITIONS ARE EXPECTED ACROSS NORTHERN PORTIONS OF THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY...WITH MVFR TO LIFR CONDITIONS ACROSS CENTRAL AND DOWNEAST AREAS. CONDITIONS WILL BEGIN TO IMPROVE ACROSS THE FORECAST AREA MONDAY AFTERNOON...THOUGH OCCASIONAL MVFR CONDITIONS WILL REMAIN POSSIBLE. OCCASIONAL MVFR CONDITIONS COULD LINGER ACROSS NORTHERN AREAS EARLY MONDAY NIGHT. OTHERWISE...VFR CONDITIONS ARE EXPECTED ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY. CONDITIONS WILL LOWER TO MVFR/IFR LEVELS LATER THURSDAY. && .MARINE... NEAR TERM: NO HDLNS XPCTD FOR THE NEAR TERM. THE COMBO OF WNW OF 10 TO 15 KT...SFC TEMPS IN THE LOW 20S AND SSTA`S IN THE UPPER 30S TO LOWER 40S RESULTED IN LGT FZSPY OVR OUR WATERS TNGT INTO ERLY SUN MORN...AFTERWHICH WINDS DROP ENOUGH FOR FZSPY TO NO LONGER BE AN ISSUE LATE SUN MORN ONWARD. WENT WITH A BLEND OF OPNL/MOS MODEL GUIDANCE FOR WINDS...AND WENT ABOUT A HLF FOOT HIGHER THAN WW3 WV GUIDANCE. SHORT TERM: CONDITIONS ARE GENERALLY EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY NIGHT THROUGH MONDAY NIGHT...THOUGH WIND GUSTS COULD APPROACH SMALL CRAFT ADVISORY LEVELS MONDAY AFTERNOON INTO EARLY MONDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS ARE THEN POSSIBLE TUESDAY. VISIBILITIES WILL BE REDUCED IN SNOW SUNDAY NIGHT INTO MONDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
336 AM EST SUN FEB 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM EST SUN FEB 9 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER THE UPR LKS TO THE SW OF CORE OF ARCTIC AIR SITUATED OVER QUEBEC. RIBBON OF MUCH STRONGER W FLOW IS EVIDENT OVER THE S 2/3 OF THE CONUS. A FAIRLY STRONG DISTURBANCE EMBEDDED IN THIS FASTER FLOW IS MOVING THRU CENTRAL WI EARLY THIS MRNG. ACCOMPANYING PCPN HAS REACHED AS FAR N AS GRB OR SO...BUT OVERALL DRY AIRMASS IN PLACE WITH PWAT NO HIER THAN 0.10 TO 0.15 INCH IS LIMITING THE IMPACT OVER UPR MI TO JUST SOME MID CLD DESPITE PRESENCE OF AREA OF ACCOMPANYING H85-5 QVECTOR CNVGC. LGT WINDS AND LO PWAT HAVE ALLOWED TEMPS TO FALL BLO ZERO AT MOST PLACES DESPITE THESE CLDS. THERE ARE SOME LK CLDS NEAR SUPERIOR WITH H85 TEMPS ARND -20C DESPITE LGT NW FEED OF DRY LLVL AIR SHOWN ON THE 00Z INL RAOB AND EXTENSIVE ICE COVER. THE MQT RADAR DOES SHOW A FEW HIER RETURNS OVER SCENTRAL LK SUP...SO THERE ARE PROBABLY SOME ISOLD -SHSN DESPITE THESE NEGATIVES FOR LES. LOOKING UPSTREAM...THERE IS A SHRTWV OVER SW SASKATCHEWAN AND ANOTHER DROPPING SWD NEAR LK WINNIPEG. MAIN FCST CONCERNS IN THE SHORT TERM ARE LIMITED POPS ASSOCIATED WITH ARRAY OF SHRTWVS MENTIONED ABOVE AND TEMPS. TODAY..AREA OF QVECTOR CNVGC ASSOCIATED WITH SHRTWV MOVING TO THE S IS FCST TO MOVE E THIS MRNG AND EXIT THE AREA SOON AFTER SUNRISE. SO ACCOMPANYING MID CLD COVER SHOULD SHIFT TO THE E AS DRIER MID LVL AIR FOLLOWS. BUT THE SHRTWV OVER SW SASKATCHEWAN IS FCST TO TRACK INTO SCENTRAL WI LATE THIS AFTN...WITH AREA OF H85-5 QVECTOR CNVGC ARRIVING THIS AFTN OVER UPR MI. GIVEN THE ABSENCE OF ANY MSTR INFLOW WITH LLVL NW FLOW IN THE WAKE OF DEPARTING FIRST DISTURBANCE... SUSPECT THE IMPACT FOR THE CWA WL BE THE SAME AS WHAT IS HAPPENING NOW...JUST SOME MID CLD. SO HAVE OPTED TO REMOVE POPS...AT LEAST AWAY FM LK SUP. THE MAIN CONCERN IS HOW MUCH LK EFFECT PCPN THERE MAY OR MAY NOT BE. MOST OF THE HI RES MODELS ARE SHOWING NO PCPN NEAR THE LK THRU THE DAY...WITH ICE COVER...ABSENCE OF CYC FLOW /IN FACT SHOWING ACYC FLOW/...AND LLVL DRY ADVECTION SUPPRESSING THIS ACTIVITY. ON THE OTHE HAND...THE LOWER RES GFS/ECMWF LIGHT QPF SUGGEST SOME SHSN IN THE NW WIND SN BELTS. THE GFS ICE ANALYSIS DOES SHOW A REASONABLE AMOUNT OF OPEN WATER OVER CENTRAL LK SUP WHILE THE NAM/GEM INDICATE A COMPLETELY COVERED LK. SINCE THERE HAVE BEEN SOME BREAKS IN THE ICE RECENTLY AND THERE ARE AND HAVE BEEN SOME LGT SHSN AS WELL...WL TEND TOWARD THE LO RES MODELS AND INCLUDE SOME LO CHC POPS IN THE FAVORED SN BELTS THRU THE DAY AS THE LLVL NW FLOW DROPS H85 TEMPS TO ARND -23C BY 00Z MON OVER THE W. THIS CAD SHOULD KEEP MAX TEMPS LOWER THAN YDAY...WITH THE HIER TEMPS OVER THE SCENTRAL WITH SOME DOWNSLOPE FLOW AND PROBABLY SOME SUNSHINE BTWN THE SHRTWVS. TNGT...SHRTWV NOW NEAR LK WINNIPEG IS PROGGED TO DROP SEWD AND OVER UPR MI BY 12Z MON AS WI DISTURBANCE SHIFTS INTO THE LOWER LKS. THIS QUICK PROGRESSION OF SHRTWVS IS FCST TO MAINTAIN SOME DEEP LYR QVECTOR CNVGC THRU THE NGT...SO THERE WL PROBABLY BE QUITE A BIT OF AT LEAST MID/HI CLD EVEN OVER THE INTERIOR EVEN THOUGH LLVL DRYING SHOULD PREVENT ANY PCPN THERE. CLOSER TO LK SUP...WL MAINTAIN SOME LOWER CHC POPS FOR LES WITH H85 TEMPS FALLING TOWARD -24C DESPITE FCST NEUTRAL/ACYC NW FLOW AND CONSIDERABLE ICE COVER. THE GFS SHOWS STRONGER LLVL WINDS THAN THE OTHER MODELS...BUT OUT OF PHASE SHRTWVS/EXTENSIVE ICE COVER THAT WL LIMIT PRES FALLS OVER THE OPEN WATER AND SHARPNESS OF THE PRES GRADIENT INDICATE THE WEAKER WINDS SHOWN BY THE BULK OF THE OTHER GUIDANCE ARE ON THE RIGHT TRACK. THIS DIFFERENCE IN WIND SPEEDS COULD BE CRITICAL IN DETERMINING WHETHER WIND CHILLS WL REACH ADVY THRESHOLDS AS SFC TEMPS FALL WELL BLO ZERO...ESPECIALLY OVER THE W HALF. WITH THE WEAKER WINDS...EXPECT NEITHER THE WIND CHILLS NOR THE WIND SPEEDS WL BE SUFFICIENT FOR AN ADVY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 303 AM EST SUN FEB 9 2014 AFTER STARTING THE LONG TERM PERIOD UNDER A COLD NORTHERN STREAM TROUGH...IT/S DEPARTURE ON MONDAY NIGHT WILL LEAD TO A MORE PROGRESSIVE AND WARMER PATTERN FOR THE REST OF THE WORK WEEK AND INTO NEXT WEEKEND. WITH COLD 850MB TEMPS (-24C) UNDER THE UPPER TROUGH ON MONDAY...THERE WILL BE PLENTY OF OVER LAKE INSTABILITY FOR LAKE EFFECT IN THE AREAS THAT HAVE OPEN WATER. BUT MODIS SATELLITE FROM TODAY SHOWS THAT THOSE AREAS ARE VERY LIMITED...BUT THERE WERE STILL PERIODS OF CLOUDS AND LIGHT LAKE EFFECT OVER THE LAST DAY. THUS...WILL CONTINUE TO FOLLOW PREVIOUS SHIFTS OF SLIGHT AND CHANCE POPS IN THE NORTHWEST WIND FAVORED LOCATIONS DURING THE DAY ON MONDAY. WITH THE AMOUNT OF COLD AIR PRESENT...ALONG WITH LIMITED OPEN WATER...DON/T THINK SNOW WILL AMOUNT TO MUCH...UNLESS SOME WATER OPENS UP MORE THAN CURRENTLY SEEN. SINCE THERE WILL BE ABUNDANT MOISTURE ROTATING THROUGH THE CWA (CURRENTLY BETWEEN LAKE WINNIPEG AND HUDSON BAY)...WILL GO WITH MOSTLY CLOUDY SKIES OVER MUCH OF THE CWA. MONDAY WILL BE ONE OF THE COLDER DAYS FOR THE FORESEEABLE FUTURE...WITH HIGHS OVER THE WEST IN THE LOW SINGLE DIGITS ABOVE ZERO AND MID-UPPER SINGLE DIGITS ELSEWHERE. UPPER TROUGH WILL QUICKLY SHIFT EAST ON MONDAY NIGHT AND ALLOW RIDGING TO BUILD INTO THE AREA AT THE SURFACE AND ALOFT. THE SURFACE RIDGE...FROM THE HIGH SLIDING THROUGH THE UPPER MISSISSIPPI VALLEY...WILL LEAD TO DRIER AIR...WARMING ALOFT...AND WEAKENING/BACKING WINDS WHICH WILL DIMINISH THE SNOW CHANCES FROM WEST TO EAST THROUGH THE NIGHT AND INTO TUESDAY MORNING. WITH THE DRY RIDGE MOVING IN ON MONDAY NIGHT...SHOULD SEE INLAND TEMPERATURES REALLY FALL WERE SKIES CLEAR OUT. GOING FORECAST HAS OVERNIGHT LOWS NEAR THE WISCONSIN BORDER NEAR -20F AND THAT SEEMS FAIRLY REASONABLE. DIDN/T MAKE MANY CHANGES TO THOSE VALUES...SINCE SOME OF THE COLDER MODELS EVEN HAVE VALUES AROUND -24F AND BASED OFF SOME OF THE COLD SPOTS THE LAST COUPLE NIGHTS IT DOESN/T SEEM TOO UNREASONABLE. WITH TEMPERATURES THIS COLD...IT WON/T TAKE MUCH FOR WIND CHILLS TO NOSE INTO THE ADVISORY CRITERIA. BUT WITH WINDS LOOKING TO BE WELL BELOW 10MPH...SHOULD NOT NEED A WIND CHILL ADVISORY. THE HIGH PRESSURE RIDGE WILL SHIFT EAST OF THE REGION ON TUESDAY AND LEAD TO SOUTHWESTERLY FLOW DEVELOPING OVER THE AREA. THIS WILL START A WARMING TREND THAT WILL BRING TEMPERATURES CLOSER...BUT STILL BELOW NORMAL...FOR THE REST OF THE WORK WEEK. THE FIRST IN A SERIES OF SHORTWAVE TO AFFECT THE REGION IN THE NEARLY ZONAL FLOW WILL MOVE THROUGH THE UPPER GREAT LAKES ON TUESDAY NIGHT. SOME DISCREPANCY IN THE MODELS ON THE WHERE THE PIECES OF ENERGY TRACK...BUT THE GENERAL IDEA IS FOR SOME ENERGY TO MOVE THROUGH ON TUESDAY NIGHT AND THEN A COLD FRONT ASSOCIATED WITH A LOW OVER HUDSON BAY TO SWEEP THROUGH ON WEDNESDAY. HAVE FOLLOWED THAT IDEA FOR A WEST TO EAST PUSH OF CHANCE POPS THROUGH THE CWA. OVERALL...LOOKS LIKE A DUSTING TO 2 INCHES OF SNOW ON TUESDAY NIGHT AND WEDNESDAY. THE NEXT SHORTWAVE MOVES THROUGH THE NORTH CENTRAL CONUS ON THURSDAY AND ONCE AGAIN THERE ARE DIFFERENCES IN THE MODELS. THIS TIME...THE GFS/GEM ARE IN DECENT AGREEMENT WITH THE SHORTWAVE INTENSIFYING THE LOW MOVING THROUGH THE NORTHERN PLAINS AND TRACKING IT THROUGH THE UPPER GREAT LAKES THURSDAY AND THURSDAY NIGHT. THE ECMWF ON THE OTHER HAND TRACKS A WEAKER LOW FARTHER SOUTH AND SLOWER THROUGH THE LOWER GREAT LAKES. ALL IN ALL...IT APPEARS THAT THERE WILL BE SOME DISTURBANCE AFFECTING THE AREA DURING THE SECOND HALF OF THE WORK WEEK. WITH THE TRADITIONAL FASTER GFS AND SLOWER ECMWF SOLUTIONS USUALLY MERGING AND SPLITTING THE DIFFERENCES...THINK THE AREA WILL POTENTIALLY EXPERIENCE NEAR ADVISORY SNOWFALL AROUND THE THURSDAY INTO THURSDAY NIGHT PERIOD. WILL KEEP POPS AT THE CHANCE CATEGORY UNTIL MODELS COME INTO BETTER AGREEMENT ON THE TIMING. BEHIND THAT DISTURBANCE...MODELS SHOW A HIGH PRESSURE RIDGE MOVING INTO THE AREA AND PRODUCE A DRY FRIDAY BEFORE ANOTHER SHORTWAVE APPROACHES WISCONSIN ON SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1116 PM EST SAT FEB 8 2014 EXPECT VFR CIGS TO LOWER TO MVFR AT ALL TAF SITES AS VARIABLE WINDS SHIFT NW BTWN 08-14Z THIS MORNING. SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE...BUT GIVEN EXTENSIVE ICE COVERAGE...IT IS HARD TO FCST VSBY LOWER THAN VFR AS NW WINDS WILL NOT BE THAT STRONG AND SHOULDN/T CONTRIBUTE TO MUCH BLOWING SNOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 335 AM EST SUN FEB 9 2014 WITH A RELATIVELY WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES THRU MID WEEK...EXPECT WINDS UNDER 20 KTS MOST OF THE TIME. THE BEST CHANCE FOR STRONGER WINDS WILL BE ON MON...WHEN NW WINDS MAY BE AS HI AS 25 KTS AHEAD OF HI PRES MOVING INTO THE UPPER MISSISSIPPI RIVER VALLEY. A STRONGER S-SW WIND UP TO 25 KTS MAY IMPACT PORTIONS OF THE LAKE ON TUE NIGHT UNDER THE SHARPENING PRES GRADIENT BETWEEN THIS DEPARTING HI MOVING INTO THE MID ATLANTIC STATES AND A LO PRES TROF APPROACHING FROM THE W. ALTHOUGH VERY COLD AIR WILL LINGER THRU TUE...EXPECT LITTLE POTENTIAL FOR FREEZING SPRAY WITH THE EXTENSIVE ICE COVER ON THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1049 PM CST SAT FEB 8 2014 .AVIATION... 06Z TAF CYCLE COLD FRONT TO PUSH THROUGH THE GUYMON AND DALHART TAF SITES BETWEEN 08Z AND 11Z SUNDAY...AND THEN ACROSS THE AMARILLO TAF SITE BETWEEN 12Z AND 15Z SUNDAY. VFR CONDITIONS WILL PREVAIL AT THE AMARILLO TAF UNTIL AROUND 18Z TO 21Z SUNDAY AND AROUND 14Z TO 17Z SUNDAY AT THE DALHART TAF SITE...BUT WILL QUICKLY FALL TO IFR OR VLIFR TO IFR AT THE GUYMON TAF SITE BY 10Z TO 13Z SUNDAY. LOW CLOUDINESS AND AREAS OF FREEZING FOG WILL SPREAD WEST AND SOUTH BEHIND THE COLD FRONT ACROSS THE PANHANDLES BY SUNDAY AFTERNOON. LIGHT WEST WINDS 5 TO 10 KNOTS OR LESS WILL SHIFT TO THE NORTH AND NORTHEAST 10 TO 20 KNOTS ONCE THE COLD FRONT MOVES THROUGH. SCHNEIDER && .PREV DISCUSSION... /ISSUED 742 PM CST SAT FEB 8 2014/ UPDATE... ONCE AGAIN THIS EVENING...THE LATEST RUN OF THE HRRR SHOWING LOW VISIBILITIES AND CEILINGS DEVELOPING OR SPREADING WEST FROM OFF THE CAPROCK TO NEAR A TEXAS COUNTY OKLAHOMA TO CLARENDON TEXAS LINE. WILL CONTINUE TO MONITOR DEVELOPMENTS AS A FREEZING FOG ADVISORY MAY ONCE AGAIN BE NEEDED TONIGHT AND SUNDAY MORNING FOR PORTIONS OF THE EASTERN AND POSSIBLY CENTRAL SECTIONS OF THE PANHANDLES. ALSO...THE FREEZING FOG MAY SPREAD FURTHER WEST INTO THE AMARILLO AND CANYON AREAS AND ANOTHER UPDATE MAY BE NEEDED. OTHERWISE...WILL BRING THE WIDESPREAD FREEZING FOG AS FAR WEST...FOR THE MOMENT...TO A TEXAS COUNTY TO CLARENDON LINE AND WILL HOLD OFF FOR NOW ON A FREEZING FOG ADVISORY WITH THE STIPULATION THAT ONE MAY BE NEEDED LATER ON. ALL PUBLIC PRODUCTS HAVE BEEN UPDATED AND SENT. SCHNEIDER PREV DISCUSSION... /ISSUED 534 PM CST SAT FEB 8 2014/ AVIATION... 00Z TAF CYCLE NORTHWESTERLY UPPER FLOW ACROSS THE PANHANDLES AND UPPER TROUGH OVER THE ROCKIES WILL KEEP CONSIDERABLE HIGH LEVEL CLOUDINESS THROUGH 00Z MONDAY. LOW CLOUDINESS AND POSSIBLY SOME AREAS OF FREEZING FOG WILL SPREAD FROM NORTHEAST TO SOUTHWEST BEHIND A COLD FRONT TONIGHT AND SUNDAY. THIS FRONT WILL MOVE THROUGH THE GUYMON TAF SITE AROUND 08Z TO 11Z SUNDAY...ACROSS THE AMARILLO AND DALHART TAF SITES BETWEEN 12Z AND 15Z SUNDAY. LIGHT WINDS TONIGHT 5 TO 15 KNOTS WILL SHIFT TO THE NORTH AND NORTHEAST AFTER FRONTAL PASSAGE AND INCREASE TO AROUND 10 TO 20 KNOTS. VFR CONDITIONS EARLY WILL BECOME IFR TO MVFR BEHIND THE COLD FRONT AND DROPPING TO VLIFR TO LIFR AT THE GUYMON TAF SITE AFTER 12Z TO 14Z SUNDAY. SCHNEIDER PREV DISCUSSION... /ISSUED 246 PM CST SAT FEB 8 2014/ DISCUSSION... CURRENTLY 63 DEGREES AT THE NWS AMARILLO OFFICE...FIRST TIME AMARILLO HAS BEEN ABOVE 50 OR 60 DEGREES SINCE JANUARY 30. MOST OF THE AREA IS WARM EXCEPT FOR THE FAR EASTERN AND NORTHEASTERN PANHANDLES. THE WARMING IN THESE LOCATIONS IS BEING INHIBITED BY SNOW PACK...WILL ALSO HAVE TO WATCH THESE AREAS AS THEY HAVE THE BEST CHANCE FOR ANOTHER ROUND OF FREEZING FOG OVERNIGHT. WILL NOT ISSUE A FREEZING FOG ADVISORY AT THIS TIME SINCE LAST NIGHT LOCATIONS WITH A 6 DEGREE DEWPOINT DEPRESSION RECEIVED FOG BUT MOISTER AREAS DID NOT. MIGHT HAVE TO WAIT TILL WE SEE THE WHITES OF THE FREEZING FOGS EYES TO SEE WHERE PATCHY FOG MIGHT SET UP. COLD FRONT WILL PUSH SOUTH IN THE EARLY AM HOURS TOMORROW AND KNOCK BACK TEMPERATURES ACROSS THE AREA. SLIGHT CHANCE FOR LIGHT SNOW IN THE NORTHEAST PANHANDLES OVERNIGHT TOMORROW BUT MOST OF THE AREA WILL STAY DRY. MODELS ARE STILL COMING IN WITH THE SYSTEM MOVING FURTHER SOUTH AND KEEPS MOST OF OUR AREA DRY. BEST CHANCE FOR PRECIP FOR THE NEXT 7 DAYS LOOKS TO BE IN THE SOUTHWEST MONDAY EVENING/NIGHT. IF SNOW DOES FALL IN OUR AREA IT LOOKS TO BE VERY LIGHT. REST OF THE WEEK LOOKS DRY AND WARM AS HIGH TEMPERATURES CLIMB INTO THE FIFTIES AND SIXTIES FOR THE SECOND HALF OF THE WEEK. FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH FRIDAY. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...FREEZING FOG ADVISORY UNTIL 10 AM CST SUNDAY FOR THE FOLLOWING ZONES: COLLINGSWORTH...DONLEY...GRAY...HEMPHILL... LIPSCOMB...OCHILTREE...ROBERTS...WHEELER. OK...FREEZING FOG ADVISORY UNTIL 10 AM CST SUNDAY FOR THE FOLLOWING ZONES: BEAVER. && $$ 11/08
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
359 AM EST SUN FEB 9 2014 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE FROM THE WESTERN GREAT LAKES ACROSS THE OHIO VALLEY AND INTO PENNSYLVANIA TODAY...ITS ASSOCIATED SURFACE COLD FRONT CROSSING THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. COLD HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST TUESDAY. NEXT WEEK...AN AREA OF LOW PRESSURE IS FORECAST TO DEVELOP OVER TEXAS...AND SLOWLY MOVE EAST ACROSS THE SOUTHERN STATES TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 305 AM EST SUNDAY... EARLY THIS MORNING...SHORTWAVE WAS MOVING INTO WRN TN WITH AREA OF RETURNS ON RADAR...BUT PER SFC OBS...NOT MUCH OF THIS REACHING THE GROUND. LATEST HRRR PICKED UP ON THIS FEATURE WELL...AND THE 00Z ECMWF SNAGGED IT BETTER THAN THE NAM/GFS...WITH THE LOCAL WRF NOT TOO BAD EITHER. NONETHELESS..THE MODELS SEEM TO FADE THIS FEATURE AS IT HEADS EAST. HOWEVER...COLD FRONT MOVING ACROSS THE WRN OHIO VALLEY THIS MORNING WILL BRING A BETTER CONVERGENT PATTERN WITH SOME UPPER SUPPORT TO THE MOUNTAINS BY MIDDAY. KEPT POPS HIGHER IN THE NW...THEN SHIFT THEM TO LESS THAN 15 PERCENT IN THE NW NC PIEDMONT. THIS SEEMS TO BE A CASE WHERE THE BEST LIFT SHIFTS ACROSS THE MTNS OF WV/ALLEGHANYS AND THE ENE INTO NRN VA...AS UPPER PATTERN SHOWS SPLIT BETWEEN TWO SHORTWAVES. SOUNDINGS FORECASTING MAINLY SNOW OR RAIN SHOWERS THROUGH THIS EVENING...BUT SOME SUPPORT TO INCLUDE ICE PELLETS EXISTS...ALTHOUGH SHORT LIVED OVER THE HIGHER ELEVATIONS OF SW VA/NW NC THIS AFTERNOON. OVERALL...SNOW AMOUNTS ARE STAYING UNDER 2 INCHES...WITH HIGHER ELEVATIONS OF WRN GREENBRIER TOPPING OUT WITH 2...WHILE REST OF THE WRN SLOPES WILL GET AN INCH OR SO...WITH LESS THAN AN INCH INTO THE MOUNTAINS OF THE NEW RIVER VALLEY...SOUTHWEST TOWARD THE NC MTNS. MODELS HINT AT EVEN AREAS NORTH OF ROANOKE AND LYNCHBURG ALONG THE RIDGES COULD SEE A DUSTING TO JUST UNDER AN INCH. AGAIN...THE CMC/NAM FAVOR CLEARING BEHIND THIS WAVE LATE THIS MORNING INTO THE AFTERNOON OVER THE NC FOOTHILLS PIEDMONT. LEANED TOWARD A CLOUDIER SOLUTION...AS THESE MODELS DID NOT PICK INITIALIZE WELL WITH THE ONGOING SAT TRENDS...SO LEANED MY SKY COVER FORECAST TOWARD A LOCAL WRF/MOSGUIDE SOLUTION. STILL COULD SEE ENOUGH SUN IN THE SOUTHEAST TO WARM TEMPS INTO THE LOWER 50S AHEAD OF THE FRONT. MEANWHILE CLOUDS AND COLD ADVECTION IN THE MOUNTAINS THIS AFTERNOON WILL HINDER TEMPS. TEMPS FOR TODAY ARE TRICKY GIVEN CLOUD COVER/PRECIP AND TIMING OF COLD AIR ADVECTION. WENT WITH MID TO UPPER 30S ALLEGHANY HIGHLANDS...GREENBRIER COUNTY WV TO MID 40S NEW RIVER VALLEY/NC MTNS...AND UPPER 40S TO LOWER 50S ROA-LYH...MID 50S SOUTHSIDE VA...NW NC FOOTHILLS/PIEDMONT. DECENT ENOUGH PRESSURE GRADIENT BEHIND THE FRONT THIS AFTERNOON/EVENING TO SEE GUSTS TO 30 MPH OVER THE MOUNTAINS. THROUGH TONIGHT...THE MODELS ARE FAVORING WRN SLOPES WITH SNOW SHOWERS...WHERE AN ADDITIONAL INCH IS POSSIBLE WRN GREENBRIER AND LESS ELSEWHERE THE MOUNTAINS. FRONT EXPECTED TO REACH A NORFOLK VA TO ATL GA LINE OVERNIGHT BEFORE STALLING DUE TO PARALLEL UPPER FLOW. SKIES STAY CLOUDY IN THE WEST WITH MOSTLY CLOUDY WITH SOME BREAKS OUT EAST. LOWS RANGE FROM THE LOWER 20S ACROSS SE WV...TO LOWER 30S PIEDMONT. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... AS OF 344 AM EST SATURDAY... MODELS ARE IN FAIRLY GOOD AGREEMENT WITH PUSHING A SURFACE FRONT ACROSS THE AREA AND INTO NORTH CAROLINA MONDAY. HOW FAR SOUTH DOES THIS FRONT GO MONDAY NIGHT INTO TUESDAY IS QUESTIONABLE...CONSIDERING THE EASTERN HALF OF THE US WILL BE UNDER ZONAL FLOW. ALL 00Z MODELS ARE PUSHING THE FRONT DOWN INTO THE GULF. JUST INLAND AND BEHIND THE FRONT...A MID LEVEL DISTURBANCE IS EXPECTED TO TRACK ALONG THE GULF STATES INTO SOUTHEASTERN US MONDAY NIGHT INTO TUESDAY. TUESDAY NIGHT INTO WEDNESDAY...A STRONGER WAVE WILL FOLLOW IN THE FOOT STEPS OF THE FIRST DISTURBANCE. THE CURRENT FORECAST TRACK OF BOTH SYSTEMS ARE FAR ENOUGH TO THE SOUTH TO KEEP MOST OF THE FORECAST AREA DRY. IF MOISTURE DOES ADVANCE NORTH THROUGH THE PERIOD...THE HIGHEST PRECIPITATION CHANCES (30 PERCENT) WOULD BE ALONG AND SOUTH OF THE NC/VA BORDER. THERE IS ALSO ANOTHER PLAYER TO THIS GAME. A COLD HIGH PRESSURE SYSTEM IS EXPECTED TO TRACK FROM THE UPPER MID WEST MONDAY NIGHT AND OVER THE OHIO VALLEY TUESDAY. THIS RIDGE WILL THEN WEDGE DOWN THE EAST COAST TUESDAY NIGHT INTO WEDNESDAY. THIS RIDGE WILL BRING COLD AIR AND EASTERLY FLOW TO HAVE MOST OF THE PRECIPITATION FALLING AS SNOW. THE WAY IT LOOKS RIGHT NOW...OUR WEATHER WILL BE DOMINATED BY THE COLD DRY HIGH. THEREFORE I KEPT ANY POPS IN THE PERIOD LOW AND TO THE SOUTH. IT IS THE SECOND STRONGER WAVE THAT HAS ME MORE CONCERN. EVEN THOUGH THIS WAVE TRACKS ALONG THE GULF STATES...OVERRUNNING MOISTURE AND WARM NOSE MAY BE SIGNIFICANT ENOUGH TO PRODUCE P-TYPE ISSUES FOR THE FORECAST AREA WEDNESDAY AND WEDNESDAY NIGHT AS PER 00Z ECM. SINCE MODELS HAVE A DIFFERENT OPINION OF WHERE THE SECOND WAVE TRACKS AND BEHAVES...WILL WAIT AND TACKLE THIS PROBLEM AT A LATER TIME. TEMPERATURES MONDAY WILL BE A LITTLE TRICKY WITH THE PASSING OF A SLOW MOVING COLD FRONT. GUIDANCE TEMPERATURES...ESPECIALLY IN THE EAST VARY GREATLY. GFSMOS FOR DANVILLE HAS A HIGH OF 46F WHILE THE NAMMOS IS COLDER AT 38F. SINCE THE FRONT IS A SLOW MOVER AND A WEST WIND DEVELOPS QUICKLY...LEANED TEMPERATURES TOWARDS THE WARMER GFSMOS...ESPECIALLY IN THE EAST. ON TUESDAY...UNDERCUT GUIDANCE WITH INCREASING EASTERLY FLOW. I WENT EVEN COLDER THAN GUIDANCE ON WEDNESDAY AS PRECIPITATION CHANCES ARE ON THE INCREASE WITH A COLD WEDGE IN PLACE. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... AS OF 325 PM EST FRIDAY... BECAUSE OF THE GREAT VARIABILITY IN THE MEDIUM RANGE SOLUTION...WILL LEAN TOWARDS HPCGUIDE SHAPED AWAY FROM THE DETERMINISTIC GFS AND ECMWF...AND MORE TOWARD THE SURFACE LOW AND TRACKS OF THE GEFS AND EC ENSEMBLE MEANS. GUIDANCE REMAINS IN DISAGREEMENT WITH THE ECMWF/CMC MORE CONSISTENT WITH PREVIOUS RUNS AND FURTHER NORTH WITH THE MOISTURE...COMPARED TO GFS BEING SLOWER AND WARMER WITH MORE SOUTHERN TRACK. DECIDED TO KEEP THE HIGHEST POPS FROM WEDNESDAY NIGHT INTO THURSDAY. BECAUSE OF THE UNCERTAINTY WITH THIS WINTER STORM...HARD TO WORK OUT THE EXACT DETAILS OF TIMING...TRACK AND SNOW ACCUMULATIONS AT THIS POINT. THURSDAY AFTERNOON INTO THURSDAY NIGHT...COASTAL LOW PRESSURE CENTER AND ITS ASSOCIATED COLD FRONT WILL CONTINUE TO MOVE OUT INTO THE ATLANTIC OCEAN. MEANWHILE...LOW PRESSURE WITH A TRAILING COLD FRONT WILL DROP SOUTHEAST ACROSS THE GREAT LAKES. ON THE FRIDAY...THE COLD FRONT WILL CONTINUE TO MOVE EAST AS HIGH PRESSURE BUILDS OVER THE MIDWEST. IN THIS PROGRESSIVE FLOW...A COLD FRONT WILL TRAVEL EAST ACROSS OUR AREA ON SATURDAY. PLACED THE HIGHEST POPS IN THE WESTERN MOUNTAINS. TEMPERATURES WILL START COLD AND SLOWLY MODERATE TOWARDS THE END OF THE WEEK. THEN...A COOLING TEND IS EXPECTED INTO EARLY NEXT WEEK. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... AS OF 1135 PM EST SATURDAY... EXPECT A TREND TOWARD LOWER FLIGHT CATEGORIES LATE TONIGHT FOR MUCH OF THE MOUNTAINS. KBLF AND KLWB WILL DETERIORATE TO IFR/LIFR CEILINGS LATE TONIGHT. A SHORT WAVE THAT WILL CROSS THE TENNESSEE VALLEY AND INTO THE CAROLINAS TONIGHT AND EARLY SUNDAY WILL KEEP VFR CLOUDS OVER THE REST OF THE AREA. THERE IS A VERY LOW PROBABILITY THAT SOME LIGHT RAIN MAY DEVELOP AROUND KDAN AS THIS WAVE PASSES JUST TO THE SOUTH. TEMPERATURE/DEW POINT SPREAD AT KBCB IS ONLY A COUPLE OF DEGREES. THE SNOW FROM SATURDAY MORNING HAS MELTED LEAVING THE GROUND WET. THERE MAY BE PATCHES OF MVFR FOG EARLY SUNDAY MORNING. LOW LEVEL FLOW WILL INCREASE FROM THE SOUTHWEST ON SUNDAY MORNING IN ADVANCE OF YET ANOTHER SHORTWAVE TROUGH MOVING THROUGH THE OHIO VALLEY. WE EXPECT MOST AREAS TO HAVE VFR CONDITIONS BY 16Z/11AM...BUT NO IMPROVEMENT AT KLWB AND KBLF. THIS SHORT WAVE PUSHES A COLD FRONT WILL CROSS THROUGH THE AREA SUNDAY AFTERNOON AND EVENING. WINDS WILL INCREASE FRONT THE NORTHWEST BEHIND THE FRONT. AS A RESULT...EXPECT A RETURN OF MVFR SNOW SHOWERS ACROSS SOUTHEAST WEST VIRGINIA AND NEIGHBORING SECTIONS OF SOUTHWEST VIRGINIA THANKS TO UPSLOPE FLOW. THIS SAME NORTHWEST FLOW WILL YIELD DOWNSLOPE CLEARING EAST OF THE BLUE RIDGE. HIGH PRESSURE AND DRIER AIR BUILDS IN BEHIND THE FRONT ON MONDAY. UPSLOPE AREAS MAY OCCASIONALLY HAVE MVFR CLOUDS BUT THE REST OF THE REGION WILL HAVE VFR CONDITIONS. TUESDAY THROUGH THURSDAY CONFIDENCE IS LOW ON THE SETUP OF THE FRONTAL BOUNDARY SOUTH OF THE CAROLINAS AND THE POSSIBLY THE INFLUENCE OF A LOW OFF THE EAST COAST. SOME MODELS OFFER A SOLUTION WITH A PROLONGED PERIOD OF A WINTRY MIX OF PRECIPITATION AND SUB-VFR CONDITIONS OVER THE REGION FOR A LEAST A GENEROUS PORTION OF THIS TIME FRAME. OTHERS DO NOT OFFER SUCH A WET SOLUTION BUT HAVE PIECES OF ENERGY GIVING GLANCING BLOWS OF WEATHER AND SUB-VFR CONDITIONS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PM NEAR TERM...WP SHORT TERM...RCS LONG TERM...KK AVIATION...AMS/DS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1030 AM EST SUN FEB 9 2014 .SYNOPSIS... WEAK LOW PRESSURE IN THE OHIO VALLEY CROSSES THE MID ATLANTIC STATES THIS EVENING, PASSING OUT TO SEA SOUTH OF NOVA SCOTIA MONDAY. STRONG AND COLD HIGH PRESSURE CENTERED IN THE MIDWEST MONDAY MOVES TO NEW ENGLAND WEDNESDAY. LOW PRESSURE ALONG THE SOUTHEAST COAST WEDNESDAY MOVES NORTHEASTWARD, TRACKING TO OUR EAST THURSDAY. AN ALBERTA CLIPPER LOW PRESSURE SYSTEM MAY PASS THROUGH THE AREA NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THICKENING CLOUD COVER ACROSS OUR AREA AT LATE MORNING IN ADVANCE OF AN APPROACHING SHORTWAVE AROUND THE UPPER OHIO VALLEY AND LOWER GREAT LAKES REGION. CONTINUE TO LIKE THE TIMING OF THE ONSET OF LIGHT SNOW ACROSS OUR WESTERN ZONES FOR EARLY/MID AFTERNOON BASED ON CURRENT RADAR IMAGERY AND SURFACE OBS INDICATING LIGHT SNOW SPREADING INTO CENTRAL PA. TIMING IN THE LATEST HRRR AND SPC 4KM WRF INDICATE THE ONSET OF STEADIER PRECIP/SNOW TO BE LATE AFTERNOON ACROSS MUCH OF OUR AREA, WITH THE SPC WRF BEING THE FASTER OF THE TWO. HIGHEST POPS FOR MUCH OF THE FORECAST AREA ARE CENTERED AROUND THE 21Z TO 01Z TIMEFRAME, AND THIS LOOKS IN LINE WITH LASTEST GUIDANCE. SOME ADJUSTMENTS WERE MADE TO HOURLY TEMPS AND DEWPOINTS TO CAPTURE THE LATEST TRENDS, BUT MAX TEMPERATURES LOOK ON TRACK. MAIN FOCUS TODAY IS THE TIMING OF THE APPROACHING MID-LEVEL SHORTWAVE AND THE WEAK SURFACE INFLECTION IT HAS SPAWNED. EXPECT TODAY TO BE FILLED WITH LOTS OF STRATOCU HELPING TO KEEP TEMPERATURES LOWER THAN PREVIOUSLY THOUGHT. A BLEND OF THE MET/MAVMOS LOOKED GOOD THOUGH DID LIKE THE SLIGHTLY COOLER MAV IN SPOTS SO USED A HEAVIER WEIGHTING FOR HIGHS. WINDS WILL REMAIN RATHER LIGHT FROM THE NORTH AND BEGIN TO BACK ALL THE WAY AROUND TOWARDS THE EAST-SOUTHEAST AHEAD OF THE APPROACHING WAVE THIS AFTERNOON. LIKED THE TIMING OFF THE SREF AND NAM FOR POPS TODAY THOUGH DID SPEED THEM UP A LITTLE JUST GIVEN HOW FLAT THE MID-LEVEL FLOW IS AND QUICKLY THE WAVE SHOULD PUSH THROUGH. THE OVERALL QPF WITH THIS SYSTEM CONTINUES TO BE DOWNWARD BUT NOT TO THE POINT OF NOTHING... PROBABILISTICALLY SHOWING AT LEAST A TENTH IN MOST SPOTS WITH A QUARTER OF AN INCH POSSIBLE ACROSS OUR EXTREME NORTHWESTERN ZONES. ALL MODELS ARE SHOWING DECENT OMEGA WITHIN THE SNOW GROWTH ZONE THIS EVENING ALLOWING FOR THE BETTER RATIOS, SOMEWHERE AROUND 12-14:1...BETTER RATIOS FURTHER NORTH. THIS SHOULD YIELD A WIDESPREAD 1 TO 3 INCHES WITH SOME ISOLATED POCKETS OF 3-4 INCHES FURTHER NORTH JUST GIVEN THE HIGHER QPF AND BETTER BANDING POTENTIAL WITH THE WAVE PASSING OVERHEAD. EXPECTING LESS SNOW ACROSS SOUTHERN DELMARVA WITH THE LACK OF QPF AND MARGINAL BOUNDARY LAYER TEMPERATURES. WITH THE QUICK MOVING NATURE OF THE SYSTEM TODAY, AND MOSTLY SUB-ADVISORY AMOUNTS, WE DID NOT ISSUE A WINTER WEATHER ADVISORY. COULD SEE AN HOUR OR TWO OF MODERATE TO HEAVY RATES LATE THIS AFTERNOON DROPPING VISIBILITIES UNDER A MILE AT TIMES, BUT FIGURED THAT A COUPLE SPECIAL WEATHER STATEMENTS COULD HANDLE THIS AS WE TRACK THE BANDS/SQUALLS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... THE SURFACE LOW DRIVING THE COLD FRONT THROUGH THE REGION LIFTS OFF TO THE NORTHEAST AND WE SHOULD RAPIDLY DRY OUT AND BEGIN TO CLEAR. WINDS TURN MORE TOWARDS THE WEST LATE TONIGHT THOUGH THE COLD AIR IS A LITTLE SLOW TO ARRIVE...LOOKS LIKE AFTER MIDNIGHT. BETTER OVERNIGHT MIXING DO NOT LOOK TO ALLOW TEMPERATURES FROM DROPPING OFF TOO MUCH, THOUGH THE FRESH SNOW COVER AND CLEARING SKIES WILL HELP WITH THE DECOUPLING PROCESS. USED A HEAVY BLEND OFF THE MAV FOR LOWS TONIGHT AS WE SHOULD BE ABLE TO DROP INTO THE TEENS TO LOW-20S IN MOST PLACES...THOUGH NOT AS COLD AS THIS MORNING. && .LONG TERM /MONDAY THROUGH SATURDAY/... ***RATHER COLD MONDAY INTO WEDNESDAY BEFORE A POSSIBLE NOREASTER EARLY THURSDAY*** 500 MB: THE BROAD TROUGH IN THE EAST CONTINUES THROUGH NEXT WEEKEND. SHORT WAVES MOVING THROUGH THE BASE OF THE TROUGH WILL GENERATE PRECIPITATION HERE FROM TIME TO TIME BEGINNING DURING MID WEEK. TEMPERATURES: CALENDAR DAY AVERAGE TEMPERATURES WILL BE AROUND 7 DEGREES BELOW NORMAL MONDAY THEN NEAR 15 DEGREES BELOW NORMAL TUESDAY AND WEDNESDAY BEFORE RECOVERING TO WITHIN SEVERAL DEGREES OF NORMAL THURSDAY ONWARD. AUTOMATED CONFIDENCE IMAGERY IS GENERALLY SUPPORTIVE OF THE GFS 2M TEMPS FCST THROUGH WEDNESDAY BUT THEREAFTER THE 00Z/9 GFS 2M TEMPERATURES HAVE LARGE UNCERTAINTY AND SO CONFIDENCE IN THE GFS MOS GUIDANCE IS MUCH BELOW AVERAGE FOR THURSDAY THROUGH SATURDAY. THE ECMWF HAS A SLIGHT COLD BIAS IN ITS 2 METER TEMPS AND NCEP ADAPTED MOS TEMP GUIDANCE FOR OUR AREA (SNOW-ICE COVER RELATED?). AM NOT USING THE ECMWF 2M TEMPS NOR ITS MOS VERBATIM. THE ECMWF SEEMS TO ACCURATELY HIGHLIGHT RADIATIONAL COOLING IN THE VALLEYS VERY NICELY (BETTER THAN THE GFS) BUT ON THOSE SAME NIGHTS..IF THERE IS WIND IN THE HILLS...THE ECMWF IS THEN TOO COLD AND THE GFS APPEARS TO BE MORE ACCURATE...AT LEAST RECENTLY. THE DAILIES IN BRIEF BELOW... MONDAY THROUGH TUESDAY NIGHT...DRY AND COLD WITH GUSTY NORTHWEST WINDS TO 20 MPH MONDAY AND 15 MPH TUESDAY. THE COLDEST READINGS ANTICIPATED FOR EARLY WEDNESDAY MORNING WHEN MINIMUM TEMPERATURES ARE FORECAST TO RANGE FROM AROUND OR JUST BELOW ZERO IN THE NORTH TO THE TEENS IN THE FAR SOUTH. THE VALUES SHOULD REMAIN ABOVE THE RECORDS FOR THE DATE. THE WARMER 00Z/9 MET TEMPS WERE USED MONDAY...THE COLDER MAV MONDAY NIGHT AND 50 50 BLEND OF NCEP MOS WAS USED TUESDAY. TUESDAY NIGHTS TEMP FCST IS CONTINUITY FROM THE DAYSHIFT YDY AS THE GFS LOOKED TOO WARM. WEDNESDAY AFTERNOON THROUGH THURSDAY...THE 0000 UTC ECMWF AS ITS PREDECESSOR CYCLES REMAINS CONSISTENT IN RACING A NOREASTER UP THE COAST WEDNESDAY NIGHT INTO THURSDAY. THE GEFS IS NOW FASTER AND WPC BOUGHT INTO THE THE FASTER SOLN AS DID WE. WHILE THERE IS STILL SOME UNCERTAINTY AS TO THE TIMING...THE GREATER UNKNOWNS ARE HOW MUCH SNOW AND RAIN. THE TRACK OF THE SFC LOW WILL DETERMINE THE VERTICAL THERMAL PROFILES AND PTYPE. FOR NOW WE HAVE A MIXED BAG AND YES...THERE IS A BAND OF FREEZING RAIN IN THE FORECAST. WHILE WE DONT EXPECT MUCH IN THE WAY OF FREEZING RAIN...IT IS PART OF THE UNCERTAINTY. FOR THE MOST PART IT APPEARS THAT THIS WILL BE A FRONT END SNOW EVENT TRANSITIONING TO RAIN IN MANY AREAS BEFORE ENDING DURING THE AFTN THURSDAY. WHILE WE MAY WISH MORE DECISIVE INFORMATION...THE SOLUTIONS ARE TOO VARIED AND SO THE MIXED PRECIPITATION WORDING. SINCE THERE IS SO MUCH COLD AIR IN ADVANCE OF THE PRECIPITATION...THERE REMAINS THE POTENTIAL FOR SIGNIFICANT SNOW IN OUR REGION LATE WEDNESDAY INTO THURSDAY... ESPECIALLY NEAR AND NW OF THE INTERSTATE 95 CORRIDOR. THE TEMPERATURE FCST WEDNESDAY WAS CONTINUITY FROM YDYS FCST AND THEN THE WED NIGHT FCST IS THE 0522Z/9 WPC GUIDANCE BLENDED WITH THE 2M ECMWF TEMP FROM THE 00Z/9 RUN. THE ECMWF HAS THIS AS A COASTAL HUGGER AND WARMER THAN ANY OTHER RELIABLE MODEL WE USE FOR OUR AREA. WE EXPECT THE GFS TO CONTINUALLY DRIFT NW AND FASTER WITH TIME AS DID THE 06Z/9 GFS SOLN WHICH NOW AT LEAST BRINGS QPF INTO OUR AREA WED NIGHT AND THU... SNOW NW OF I95 AND SNOW TO RAIN OR MIXED SE OF I95. THURSDAY NIGHT THROUGH SATURDAY...PROBABLY A QUIET INTERLUDE THURSDAY NIGHT INTO FRIDAY BEFORE WE DEAL WITH AN ALBERTA CLIPPER FRIDAY NIGHT INTO NEXT WEEKEND. FOR NOW I THINK WE NEED TO CONCENTRATE ON THE WED NIGHT-THURSDAY EVENT BEFORE LOOKING FOR ANY OTHER PRECIPITATION THAT MIGHT DEVELOP NEXT WEEKEND FROM AN ALBERTA CLIPPER. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY...A BROKEN TO OVERCAST DECK OF 5000 FOOT STRATOCU IS PUSHING INTO THE REGION FROM THE WEST. WE SHOULD REMAIN UNDER THIS VFR DECK FOR A MAJORITY OF THE DAY WHILE A QUICK MOVING CLIPPER SYSTEM APPROACHES FROM THE WEST- NORTHWEST LATER THIS AFTERNOON AND EVENING. WINDS TODAY WILL REMAIN LIGHT AS THEY CONTINUE TO BACK TOWARDS THE EAST-SOUTHEAST THROUGH THE AFTERNOON HOURS. A LIGHT SNOWFALL IS EXPECTED BY EVENING AND THERE COULD BE A COUPLE HOURS OF MORE MODERATE SNOWFALL DROPPING CONDITIONS INTO THE IFR RANGE BEFORE QUICKLY JUMPING BACK UP TO MVFR FROM WEST TO EAST. TONIGHT...MVFR CIGS AND VSBYS WILL CLIMB BACK TO VFR LATE TONIGHT AS THE SNOW COMES TO AN END. WINDS WILL BACK FURTHER TOWARDS THE WEST VERY LATE TONIGHT AND WE SHOULD CONTINUE LIFT AND SCATTER OUT THE CIGS. OUTLOOK... MONDAY THROUGH TUESDAY NIGHT...MAINLY VFR. GUSTY NW WINDS 15-20 KT MONDAY AND 15 KT TUESDAY. WEDNESDAY...VFR CIGS TO START WITH A CHANCE OF DETERIORATING CONDITIONS LATE IN THE DAY AS SNOW SPREADS INTO OUR REGION FROM THE SOUTH. WIND MOSTLY EAST. WEDNESDAY NIGHT...MAINLY IFR IN SNOW OR SNOW CHANGING TO RAIN WITH A GUSTY EAST TO NORTHEAST WIND TO 30 KT POSSIBLE. THURSDAY...MAINLY IFR IN SNOW AND RAIN IN THE MORNING. POSSIBLE IMPROVEMENT IN THE AFTERNOON. A GUSTY NORTH TO NORTHWEST WIND DEVELOPING. && .MARINE... SUB-ADVISORY CONDITIONS WILL PERSIST ACROSS OUR WATERS TODAY WITH WINDS GENERALLY OUT OF THE NORTH-NORTHEAST AND TURNING TOWARDS THE SOUTH LATE IN THE DAY. A QUICK MOVING COLD FRONT WILL PUSH THROUGH THE WATERS LATE TONIGHT AND THE PRESSURE GRADIENT TIGHTENS FOR A BIT STARTING LATE TONIGHT. THIS IS WHEN WE COULD SEE SOME SMALL CRAFT GUSTS ACROSS ALL OUR WATERS, THOUGH IT IS LOOKING A LITTLE BETTER IN THE DELAWARE BAY AND OUR SOUTHERN WATERS AS THE NORTHWEST WINDS FUNNEL DOWN THE BAY. OUTLOOK... MONDAY...A SMALL CRAFT ADVISORY WILL BE IN EFFECT FOR NORTHWEST WIND GUSTS NEAR 25 KNOTS. STRONGEST WIND EARLY IN THE DAY FOR WHAT MAY BECOME ONLY A MARGINAL SCA EVENT. MONDAY NIGHT...NORTHWEST WIND GUSTS AROUND 2O KNOTS. CHANCE FREEZING SPRAY. TUESDAY THROUGH EARLY WEDNESDAY...NO MARINE HEADLINES ARE ANTICIPATED BUT FREEZING SPRAY WILL BE POSSIBLE WITH NW TO N WINDS. LATE WEDNESDAY INTO THURSDAY...DEPENDING UPON THE DEVELOPMENT AND TRACK OF A COASTAL LOW, THERE IS THE POTENTIAL FOR EASTERLY GALE CONDITIONS BEFORE THE WIND SHIFTS TO THE NW LATE THURSDAY. && .CLIMATE... THE FOLLOWING ARE RECORD LOW TEMPERATURES THAT MAY HAVE A CHANCE OF BEING WITHIN 2 DEGREES OF RECORD IF RADIATIONAL COOLING IS MAXIMIZED WEDNESDAY MORNING FEBRUARY 12. RIGHT NOW WE ARE FORECASTING LOWS TO REMAIN ABOVE THESE VALUES. ABE -6 1979 RDG -4 1934 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 6 PM EST MONDAY FOR ANZ430- 431-450>455. && $$ SYNOPSIS...DRAG NEAR TERM...HEAVENER/KLINE SHORT TERM...HEAVENER LONG TERM...DRAG AVIATION...DRAG/HEAVENER MARINE...DRAG/HEAVENER CLIMATE...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
9 AM EST SUN FEB 9 2014 .DISCUSSION... CURRENT-THIS AFTERNOON...COLD FRONT SLOWED DOWN/STALLED OVER SOUTH FLORIDA. HIGH PRESSURE OVER THE SOUTHEAST UNITED STATES BUILDING DOWN THE FLORIDA PENINSULA. A COOL NORTHERLY WINDFLOW WAS BRINGING A SLIGHTLY DRIER AIR MASS INTO CENTRAL FLORIDA. THE LATEST RUC 500MB PROG HAS THE TROUGH AXIS OVER THE EASTERN GULF OF MEXICO AND ADVANCING EAST DURING THE DAY. VISIBLE SATELLITE LOOP SHOWING THAT THE SKIES WERE CLEAR NORTH OF SOUTH BREVARD OSCEOLA AND MOSTLY CLOUDY SOUTHERN PART OF BREVARD AND OSCEOLA COUNTIES AND INTO SOUTH FLORIDA. MORNING UPDATE WILL INCLUDE ADJUSTMENTS TO THE WIND GRIDS AND TAKING A DEGREE OR TWO OFF THE HIGHS DUE TO THE COOLER AIR MASS MOVING DOWN THE PENINSULA. PREVIOUS ZONES DISCUSSION TODAY AND TONIGHT...HIGH PRESSURE BUILDING SWD INTO THE REGION WL PRODUCE DRYING ALONG WITH REDUCED CLOUD COVER BY AFTERNOON. REASONABLE TEMPERATURE RECOVERY INTO THE 70S AREAWIDE IS EXPECTED DUE TO IMPROVED SFC HEATING AFTER MORNING FOG AND SOME LOWER CLOUDS BREAK. SLOWLY VEERING WINDS DURING AFTERNOON WL BRING A SLIGHT ONSHORE FLOW AT THE COASTAL COUNTIES AND SLIGHTLY COOLER READINGS FOR HIGHS. LIGHT TO CALM WINDS OVERNIGHT WITH GOOD RADIATIONAL COOLING WILL BRING A COOLER NIGHT WITH READINGS AVERAGING IN THE LOWER 50S WITH SOME UPR 40S WEST OF I-4. SOME GROUND FOG WL DEVELOP EARLY MON BY DAYBREAK...HOWEVER DENSE FOG IS NOT EXPECTED. MON-MON NIGHT...WEAK HIGH PRESSURE OVER THE AREA WILL GRADUALLY SHIFT EASTWARD WITH DRY CONDITIONS REMAINING IN PLACE AND SKIES MOSTLY SUNNY. A WEAK FRONTAL BOUNDARY WILL SAG SOUTHWARD AND BECOME QUASI-STATIONARY ALIGNING ITSELF EAST-WEST ACROSS NORTH FLORIDA AND THE NORTH GOMEX. LIGHT WINDS WILL BECOME NORTHEAST ALONG THE COAST WITH SPEEDS BELOW 10 MPH AS A VERY WEAK PRESSURE GRADIENT WILL BE IN PLACE. TEMPERATURES WILL IN THE 70S ACROSS MOST OF THE AREA...EXCEPT LOWER 80S POSSIBLE NEAR LAKE OKEECHOBEE. LOWS WILL GENERALLY RANGE FROM THE LOW TO MID 50S OVERNIGHT...EXCEPT UPPER 50S AND PERHAPS LOWER 60S ALONG THE TREASURE COAST AND BARRIER ISLANDS. WINDS WILL FALL TO LIGHT OR CALM DURING THE EVENING. PATCHY SHALLOW FOG MAY DEVELOP OVERNIGHT BUT WILL NOT ADD TO THE GRIDS/ZONES JUST YET. TUE-TUE NIGHT...WEAK LOW PRESSURE WILL SLOWLY DEVELOP OVER THE NORTH GULF AND WILL LIE NEAR THE WESTERN FLORIDA PANHANDLE BY DAYBREAK WED MORNING. THE PREVIOUSLY MENTIONED NEAR STATIONARY BOUNDARY WILL STILL LIE ACROSS NORTH FLORIDA. A COLD FRONT WILL EXTEND SOUTHWEST FROM THIS LOW ACROSS THE WESTERN GOMEX. THE PRESSURE GRADIENT REMAINS FAIRLY WEAK THROUGH THE PERIOD WITH NEAR CALM WINDS TUE MORNING BECOMING ONSHORE NEAR THE COAST AND THIS TREND GRADUALLY WORKING INLAND THROUGH THE DAY. THE WINDS WILL BE SOUTHEASTERLY TUE EVENING WITH SPEEDS MAINLY 5 MPH OR LESS. WE WILL SEE GRADUAL INCREASING MID AND HIGH LEVEL CLOUDS FROM THE WEST DURING THE DAY AHEAD OF THE APPROACHING WEATHER SYSTEM. CONDITIONS WILL REMAIN DRY THROUGH THE EVENING...BUT WILL KEEP A LESS THAN 20 PERCENT POP FOR LATE OVERNIGHT NORTH OF THE I-4 CORRIDOR TO COVER FOR A STRAY SHOWER POSSIBILITY AS LOW LEVEL MOISTURE SLOWLY INCREASES. WED-WED NIGHT...THE LOW PRESSURE SYSTEM WILL TRACK EASTWARD DURING THE DAY AIDED BY A SHORTWAVE TROUGH ALOFT THAT WILL TRAVERSE THE DEEP SOUTH. PRECIPITATION CHANCES WILL INCREASE IN THE AFTERNOON AND EVENING AND WILL KEEP HIGHEST POPS AROUND 40 PERCENT ALONG AND NORTH OF THE I-4 CORRIDOR TAPERING BACK TO AROUND 20 PERCENT ALONG THE TREASURE COAST AND OKEECHOBEE COUNTY. HAVE ADDED 40 TO 50 PERCENT POPS ACROSS THE AREA WED NIGHT AS THE COLD FRONT IS FORECAST TO MOVE THROUGH THE AREA LATE OVERNIGHT. THE GFS/ECMWF STILL DISAGREE WITH FEATURE PLACEMENT AND STRENGTH AS THE SURFACE LOW RACES NORTHEAST UP THE MID ATLANTIC COAST OVERNIGHT. WILL CONTINUE TO KEEP SHOWER WORDING IN THE FORECAST FOR NOW LEAVING ABSENT THUNDER MENTION. EXPECT SOUTHEAST EARLY MORNING WINDS TO VEER TO SOUTHWEST THROUGH THE DAY. SOUTHWEST WINDS WILL VEER TO WEST OR NORTHWEST OVERNIGHT BEHIND THE FRONT. HIGHS ON WED PRE-FRONTAL MAINLY IN THE UPPER 70S...EXCEPT NEAR 80 DEGREES TO LOWER 80 DEGREE READINGS POSSIBLE FROM NEAR ORLANDO AND SOUTHWARD. COOLER AND DRIER AIR WILL SLOWLY START TO INFILTRATE EAST CENTRAL FLORIDA FROM THE NORTH VERY LATE OVERNIGHT. OVERNIGHT LOWS IN THE MID TO UPPER 50S NORTH OF THE I-4 CORRIDOR WITH 60 DEGREE READINGS SOUTH OF HERE EXPECTED. THU-SAT...GRADUALLY IMPROVING CONDITIONS DURING THE DAY ON THU AS THE LATEST STORM SYSTEM MOVES AWAY FROM THE FLORIDA PENINSULA. WILL KEEP SOME LINGERING SHOWER CHANCES FOR THU WITH MOISTURE AND UPPER LEVEL ENERGY TRAVERSING THE AREA STILL. NORTHWEST FLOW SHOULD DOMINATE ON THU. WEAK HIGH PRESSURE WILL BUILD INTO THE GULF COAST STATES ON THU/FRI...ALONG THE EASTERN SEABOARD AND OVER THE FLORIDA PENINSULA FRI OVERNIGHT INTO SAT. WILL KEEP DRY CONDITIONS IN THE FORECAST FRI AND INTO THE START OF THE WEEKEND. HIGH TEMPERATURES ON THU GENERALLY A FEW DEGREES BELOW CLIMO WITH A GRADUAL WARMING TREND FRI-SAT WITH SEASONAL HIGHS FRI AND SLIGHTLY WARMER FOR SAT. OVERNIGHT LOWS GENERALLY WITHIN A FEW DEGREES OF CLIMO. && .AVIATION...THE BKN-OVC VFR SKIES FROM KMLB SOUTH BECOME FEW-SCT IN THE AFTERNOON. NO FOG ISSUES THIS MORNING JUST LIFR/IFR CEILINGS THAT LIFTED AROUND 13Z. && .MARINE... CURRENT-THIS AFTERNOON...WILL KEEP THE SMALL CRAFT EXERCISE CAUTION FOR SEAS IN THE GULF STREAM THROUGH THE AFTERNOON. BUOY 009 WAS RECORDING NORTH WINDS AROUND 15 KNOTS AND 5 FOOT SEAS. THE TWO NEARSHORE SCRIPPS BUOYS WERE RECORDING 2 TO 4 FEET. THE NORTHERLY WIND PUSHING AGAINST THE GULF STREAM WILL GENERATE SEAS TO 6 FEET IN AND NEAR THE GULF STREAM THIS AFTERNOON. WINDS ARE FORECAST TO DIMINISH LATE AFTERNOON AND EVENING AS THE PRESSURE GRADIENT OVER WATER IS EXPECTED TO WEAKEN. PREVIOUS MARINE DISCUSSION MEASURED SEA HGHTS AT OUTER BUOYS ARE BELOW 6 FT EARLY THIS MORNING...HOWEVER COUNTERING WINDS OF 10 TO 15 KNOTS WL LIKELY PRODUCE HIGHER SEAS NEAR THE GULF STREAM THROUGH LATE MORNING. WL KEEP MENTION OF CAUTION FOR THE GULFSTREAM IN THE MORNING PKG. ELSEWHERE SEAS OF 3 TO 4 FT OVER THE NEAR WATERS AND SLIGHTLY HIGHER OFFSHORE THROUGH THE EVENING. MON-THU...HIGH PRESSURE WEAKENS ACROSS THE AREA INTO TUE AS THE NEXT LOW PRESSURE SYSTEM TAKES SHAPE ACROSS THE WESTERN GOMEX. THIS NEXT WEATHER SYSTEM IS CURRENTLY FORECAST TO MOVE THROUGH THE AREA LATE ON WED INTO EARLY THU. WIND SPEEDS AOB 15 KTS THRU WED MORNING WITH SOUTHERLY WINDS INCREASING WED AFTERNOON AHEAD OF THE SYSTEM AND SPEEDS 15-17 KTS WED AFTERNOON OFFSHORE...POTENTIALLY INCREASING TO 20-25 KTS WED OVERNIGHT BEHIND THE FRONT...BUT CONFIDENCE IS LOW AT THIS TIME AS TO HOW STRONG THE PRESSURE GRADIENT WILL BE WED OVERNIGHT INTO THU DUE TO POOR MODEL CONSISTENCY HERE. SEAS GENERALLY 3-4 FT INTO TUE...2-3 FT TUE NIGHT...INCREASING AGAIN TO 3-5 FT WED AFTERNOON...4-6 FT WED NIGHT OFFSHORE AND POTENTIALLY 5-8 FT OFFSHORE NORTH OF SEBASTIAN INLET INTO THU. AGAIN CONFIDENCE IS A LITTLE LOW LATER IN THE PERIOD FOR THE HIGHER SEAS. AT LEAST CAUTIONARY STATEMENTS SEEM LIKELY AROUND THIS STORM SYSTEM AND POSSIBLY SCA CONDITIONS. DRIER CONDITIONS MON-TUE...WITH INCREASING SHOWER CHANCES WED AND THU. SHOWERS MID-WEEK WILL BE OFFSHORE MOVING AND FAIRLY QUICK. THE POTENTIAL WILL EXIST THAT LATER SHIFTS MAY ADD ISOLD THUNDER TO THE FORECAST FOR LATE WED AND EARLY THU. && .FIRE WEATHER... MON...DRIER CONDITIONS ON MON MAY ALLOW FOR AFTERNOON RELATIVE HUMIDITY VALUES TO FALL INTO THE LOWER TO MIDDLE 30S FOR A FEW HOURS...MAINLY ACROSS THE INTERIOR NORTHWARD FROM OSCEOLA COUNTY. DISPERSION VALUES WILL BE RATHER POOR DUE TO A WEAK PRESSURE GRADIENT ACROSS THE REGION. && .PRELIMINARY POINT TEMPS/POPS... DAB 70 48 73 51 / 10 0 0 10 MCO 73 52 77 53 / 10 0 0 10 MLB 73 56 76 57 / 10 0 0 10 VRB 75 55 77 56 / 10 0 0 10 LEE 71 50 75 51 / 10 0 0 10 SFB 72 51 76 52 / 10 0 0 10 ORL 72 53 76 54 / 10 0 0 10 FPR 75 57 77 57 / 10 0 0 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ FORECASTS...WIMMER IMPACT WX...KELLY
AREA FORECAST DISCUSSION
NWS GOODLAND KS
557 AM MST SUN FEB 9 2014 .UPDATE... ISSUED AT 549 AM MST SUN FEB 9 2014 JUST COMPLETED AN UPDATE. LOOKS LIKE THE MAIN BAND OF SNOW AT THIS TIME IS ALONG AND NORTH OF THE KANSAS AND NEBRASKA BORDER. FURTHER SOUTH LITTLE IF ANY SNOW FALLING. GOING BY SURFACE OBSERVATIONS TO MY SOUTH AND THE 12Z DDC SOUNDING...SATURATED LOW LEVEL AIR MASS NEAR THE DENDRITIC ZONE WITH LITTLE TO NO MOISTURE ABOVE THIS. THIS MATCHES WELL WITH WHAT MODEL SOUNDINGS HAD INDICATED. OUTSIDE OF THE MAIN SNOW BAND EXPECT WHAT IS CURRENTLY GOING ON TO CONTINUE WHICH AREAS OF FREEZING FOG AND SOME FREEZING DRIZZLE. AFTER THIS BAND OF SNOW LEAVES...MESOSCALE OUTPUT INDICATING LITTLE IF ANY MORE SNOW WILL FALL FOR MUCH OF THE REST OF THE DAY. CONSIDERING THE AIR MASS IN PLACE AND NOT TO CHANGE THAT...EXPECT THE FREEZING FOG AND DRIZZLE TO CONTINUE THROUGH THE ENTIRE DAY. ADJUSTED MAXES BASED ON CURRENT READINGS AND TRENDS. ALSO ADJUSTED THE WINDS PER TRENDS AND LATEST RUC WHICH LOOKS LIKE IT IS CATCHING THIS THE BEST. && .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 339 AM MST SUN FEB 9 2014 FORECAST CONCERNS WILL BE PRECIPITATION CHANCES THROUGH THE SHORT TERM...ESPECIALLY THROUGH MONDAY...HOW COLD TO MAKE IT TODAY AND MONDAY...AND HOW MUCH WARMING OCCURS ON TUESDAY. SATELLITE SHOWING AN AMPLIFIED/BLOCKY/RETROGRESSIVE PATTERN OVER THE WESTERN HALF OF THE PACIFIC. BECAUSE THE UPPER FEATURES HAVE CONTINUED TO MOVE WEST THAT LEAVES A FAST AND NEARLY ZONAL FROM FROM THE EASTERN PACIFIC INTO THE ATLANTIC. THERE WERE SOME MODERATION IN THE LOW LEVEL AIR MASS AS SOME MELTING OF THE SNOW DID OCCUR. HOWEVER ANOTHER VERY COLD AIR MASS IN PUSHING THE REGION AT THIS TIME. AT JET LEVEL...MODELS ARE NOT GETTING THE POSITION OF THE MAIN JETS...THE ONE OVER OUR AREA RIGHT NOW AND THE ONE COMING FROM THE PACIFIC NORTHWEST. OVERALL AT THIS TIME THE GFS AND UKMET WERE DOING THE BEST. ALTHOUGH THE ECMWF WAS DOING BETTER IN THE PACIFIC NORTHWEST. AT MID LEVELS...MODELS WERE HAVING THE SAME PROBLEMS IN POSITION OF FEATURES AS AT THE JET LEVEL. MODELS TENDED TO BE TOO FAR SOUTH AND EAST WITH FEATURES. OVERALL THE GFS AND UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF AND CANADIAN. THE ECMWF IS DOING WAY BETTER THAN EVERYTHING ELSE ON THE SURFACE PATTERN... ESPECIALLY THE LOCATION OF THIS CURRENT COLD SURGE AND THE SURFACE TROUGHING TO OUR WEST. THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE CANADIAN AND NAM ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...STRONG LEFT FRONT QUADRANT OF PACIFIC NORTHWEST JET STARTS AFFECTING THE NORTHEAST HALF TO TWO THIRDS AT THE BEGINNING OF THE DAY. THIS JET SEGMENT RAPIDLY MOVES THROUGH BY 18Z AND IS TO THE NORTH OF THE AREA BY THEN. THIS IS AT THE SAME TIME A SHORTWAVE MOVES ACROSS. THE BRUNT OF LIFT LOOKS TO BE OUR NORTH. MODEL DEPICTION LOOKS SIMILAR TO WHAT THE PREVIOUS FORECAST HAD AND ONLY MADE MINOR ADJUSTMENTS. GREATEST CHANCE FOR PRECIPITATION WILL BE IN THE NORTH AND THIS MORNING. LITTLE TO NO LIFT IS AROUND FOR MOST OF THE REST OF THE DAY. PRECIPITATION TYPE IS A LITTLE MORE OF A PROBLEM TODAY. MODELS NOT AS SATURATED IN THE COLUMN AS WAS SHOWN TODAY. THE ONLY PLACE WHERE IT LOOKS LIKE ALL SNOW IS IN THE NORTHERN PORTION OF MY AREA ESPECIALLY THIS MORNING. OVER THE REMAINDER OF THE AREA...THERE LOOKS LIKE THERE COULD BE ICE IN THE COLUMN...ESPECIALLY DOWN LOW...BUT MODELS ARE INDICATING A WARM LAYER NOT TOO FAR ABOVE THE SURFACE. ALSO THE THIS AFTERNOON THERE IS LITTLE TO NO LIFT OR MID LEVEL MOISTURE AROUND. PRECIPITATION FOR MOST OF THE AFTERNOON LOOKS LIGHT AND COULD BE A MIXTURE OF FREEZING DRIZZLE OR SNOW AND ADJUST ACCORDINGLY. EXPECT LITTLE TO NO TEMPERATURE RISE. PROBLEM IS MODELS LOOK TO BE STARTING OUT TOO COLD. HOWEVER DID TEND GO TOWARD THE COOLER GUIDANCE. AT THE BEGINNING OF THE NIGHT THE MODELS HAVE COME INTO AGREEMENT IN DEVELOPING A COUPLED JET STRUCTURE OVER THE AREA. THIS INITIAL COUPLET MOVES SOUTH THROUGH THE NIGHT AND APPEARS TO BE JUST SOUTH OF THE AREA BY THE END OF THE NIGHT. A MODERATELY STRONG PV ANOMALY APPROACHES DURING THE EVENING. MESOSCALE LIFT DOES NOT APPEAR VERY ORGANIZED. ICE LOOKS TO GET INTO THE COLUMN WITH THETA-E LAPSE RATES SO SNOW APPEARS TO BE THE PHASE. FAVORED AREA FOR THE BEST CHANCE OF PRECIPITATION WILL BE SOUTH/SOUTHWEST HALF. MAIN AREA OF PRECIPITATION LOOKS TO BE OVER THE FAR SOUTH LATE IN THE NIGHT. OVERNIGHT TEMPERATURES SHOULD NOT DROP MUCH DUE TO THICK CLOUD COVER AND WINDS. MONDAY/MONDAY NIGHT...AS STATED ABOVE FIRST COUPLET APPEARS TO BE SOUTH OF THE AREA BY 12Z. HOWEVER...A FEW OF THE MODELS DEVELOP A SECONDARY NORTHERN JET STREAK JUST TO OUR NORTH AT THE BEGINNING OF THE DAY. ANOTHER RIGHT REAR QUADRANT APPEARS TO BE JUST NORTHWEST OF OUR AREA AT 12Z WITH A POSSIBLE WEAK COUPLET TO OUR WEST. THIS NORTHERN JET STREAK/RIGHT REAR QUADRANT MOVES ACROSS THE AREA DURING THE DAY. SO INCREASED POPS TO A LOW CHANCE IN THE MORNING WITH A SLIGHT CHANCE IN THE AFTERNOON AS THE LIFT IS STARTING MOVE OUT OF THE AREA. SHOULD HAVE THICK CLOUD COVER AND UPSLOPE WINDS SO LITTLE CHANCE FOR TEMPERATURES TO RISE MUCH. ONLY MADE MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST. THERE LOOKS TO BE LINGERING LIFT AND MOISTURE EARLY SO HAVE A MENTION OF FLURRIES IN THE EVENING. WINDS SHIFT AROUND TO THE WEST AND WARM AIR ADVECTION BEGINS. BECAUSE OF VARIABLE CLOUD COVER AND A SNOWFIELD...THE LOW TEMPERATURES WILL BE VERY HARD TO PIN DOWN. SUFFICE TO SAY THE LAST TIME THIS HAPPENED A FEW DAYS...THE MODELS TENDED TO BE TOO COLD. TUESDAY/TUESDAY NIGHT...A STRONG NORTH TO SOUTH JET APPROACHES THE AREA DURING THE EVENING WITH LEFT FRONT QUADRANT AFFECTING THE WESTERN THIRD TO HALF BY 06Z. MODELS DIFFER ON HOW FAST THEY MOVE THIS FEATURE THE REST OF THE NIGHT WITH THE LEFT FRONT QUADRANT AFFECT SOME PORTION OF THE AREA DURING THE LATER HALF OF THE NIGHT... MAINLY EAST. HOWEVER...MODEL SOUNDINGS ARE SHOWING A SUBSTANTIAL DRY LAYER. SO WILL ONLY EXPECT A THICKENING MID AND UPPER LEVEL CLOUD DECK WITH THIS ENTIRE PERIOD REMAINING DRY. AIR MASS WARMS SIGNIFICANTLY WITH DOWNSLOPE WINDS SPREADING OVER MOST OF THE AREA. AT FIRST GLANCE THE NWP APPEARS TO WARM. THE 2 METER TEMPERATURES ARE SLIGHTLY COOLER AND THEY DID DO BETTER YESTERDAY IN A SIMILAR SETUP TO THIS ONCE. ONLY MADE SLIGHT ADJUSTMENTS TO MAXES WITH THE COOLEST IN THE EAST AND WARMEST ALONG AND WEST OF THE COLORADO BORDER. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 339 AM MST SUN FEB 9 2014 H5 RIDGE BUILDS INTO THE WESTERN US WITH WESTERLY FLOW SHIFTING TO NW ACROSS NORTHERN PLAINS AND MEAN STORM TRACK REMAINING ALONG THE CANADIAN/US BORDER. THIS WILL RESULT IN WARMER TEMPS AND PREDOMINATELY DRY CONDITIONS. THE ECMWF IS THE ONLY MODEL ON PAST MODEL RUNS TO EVEN HINT AT LIGHT PRECIP CHANCES...HOWEVER EVEN IT HAS TRENDED FURTHER NORTH WITH TRACK OF SHORTWAVE TROUGHS EMBEDDED IN THE MEAN FLOW ALOFT. GFS/GEFS/GEM ALL SUPPORT DRY CONDITIONS AND MUCH WEAKER SHORTWAVES (AND LESS OF AN IMPACT IN THE HEIGHT FIELDS OVER OUR CWA AS A RESULT). THERE HAS ALSO BEEN A TREND BY THE LATEST ECMWF TO KEEP BACKDOOR COLD FRONTS FURTHER NORTH (IN LINE WITH OTHER GUIDANCE)...WHICH WOULD LIMIT ANY IMPACT OF THESE TROUGH PASSAGES... AND KEEP ABOVE NORMAL TEMPS IN PLACE. AT THIS POINT OTHER THAN NON MEASURABLE PRECIP HINTED AT BY ECMWF THU NIGHT-FRI (WHICH I HAVE VERY LOW CONFIDENCE IN BASED ON THE LARGE SCALE PATTERN) IT LOOKS LIKE WE ARE ABOUT TO ENTER A PROLONGED PERIOD OF MILD/DRY CONDITIONS. HIGH TEMPS SHOULD BE NEAR SEASONAL NORMS ON WED IN THE 40S...WITH HIGHS IN THE 50S LATE NEXT WEEK INTO NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 444 AM MST SUN FEB 9 2014 FOR KGLD...IFR TO LIFR CONDITIONS DUE TO CEILINGS AND FOG WILL CONTINUE THROUGH THE MORNING. FROM 18Z TO 06Z...MVFR CONDITIONS ARE EXPECTED. FROM NEAR 06Z TO THE END OF THE PERIOD...IFR CONDITIONS ARE EXPECTED. FOR KMCK...PREVAILING CONDITIONS THROUGH 18Z WILL BE MVFR. HOWEVER OCCASIONAL IFR CONDITIONS IN FOG AND SNOW WILL OCCUR. FROM 18Z TO 06Z MVFR CONDITIONS ARE EXPECTED WITH CONDITIONS BECOMING IFR AROUND 06Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...BULLER LONG TERM...DJR AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
552 AM CST Sun Feb 9 2014 ...Updated aviation section... .SHORT TERM...(Today and tonight) ISSUED AT 343 AM CST SUN FEB 9 2014 Areas of locally dense freezing fog that developed over parts of central and western Kansas after sunset were propagating southwest behind the front into the far southwest part of the state early this morning. The last few runs of the RUC and HRRR visibility progs have been pretty consistent in moving the fog south and west into southeast Colorado and the Oklahoma/Texas panhandles by 12z. This looks reasonable given the dry air advection that is currently ongoing from north central into southwest Kansas. The dense fog advisory goes until 12z and will let it ride but continue to monitor for any areal or temporal extensions. Per SREF analysis and water vapor imagery, the first upper speed max was currently moving into the upper Mississippi Valley early this morning. The subsequent speed maxes will move out along the Kansas Nebraska border today and out over Kansas tonight. Associated mid level frontogenetic forcing will move out across Nebraska and far northern Kansas this morning and over Kansas tonight. Regional radar mosaic shows light snow already moving out of Wyoming into the Nebraska Panhandle and this will continue eastward across northern Kansas and Nebraska today. The current forecast has chance pops for light snow along the I-70 corridor today. Think any measurable snow will be north of the Dodge City forecast area today. The system moving out tonight should bring some accumulating snow to west central and parts of southwest and south central Kansas tonight. The models have been consistent with this so have increased pops well into the likely category tonight. The NAM is showing a swath of 1-2 inch snowfall generally north of Highway 50 tonight. Have increased snowfall amounts a little but for now think we will not see enough to warrant a winter weather advisory. Temperatures will not rise much, if at all, today given the ongoing cold air advection. Temperatures tonight should fall well down into the single digits above zero with a few low teens possible around Elkhart and Liberal. .LONG TERM...(Monday through Saturday) ISSUED AT 355 AM CST SUN FEB 9 2014 A weak shortwave trough will move through the Central Rockies along the zonal flow late Sunday. This shortwave will then move through Kansas on Monday. Convergence and mid level moisture will increase as this feature approaches. Mostly cloudy skies are anticipated throughout the day Monday with light to moderate snow showers. Precipitation chances end from west to east Monday evening into Monday night. Snow totals remain around 1 to 2 inches across the area. However, a few areas across west central and south central Kansas could see over 2 inches by the time the system exits the area. Surrounding offices and DDC have decided to not go with a winter weather advisory at this time and have the day shift see what the next model run suggests. Cloudy skies should continue Monday night with some clearing possible across west central Kansas towards sunrise. Winds will generally be from a northeasterly direction Monday as high pressure builds into the Plains. With the cloud cover and shot of cold air advection across the area, temperatures Monday are not expected to increase much from the morning lows. Highs Monday are forecasted to range from the lower teens across central Kansas to lower 20s across far southwestern Kansas. Lows Tuesday morning are expected to range from the negative single digits across central Kansas to around 10 degrees across far southwestern Kansas. However, if more clearing occurs overnight, temperatures could end up lower than what the current forecast depicts. The dome of high pressure moves east of the area on Tuesday shifting winds to the southwest. A few low level clouds may continue in the morning across south central Kansas Tuesday morning. Otherwise expect partly cloudy skies and dry conditions. The Central High Plains will then be stuck in between an upper level ridge across the western US and an upper level long wave trough across the eastern United states throughout the remainder of the forecast period. A few weak shortwaves are progged to move north of the area, but do not look to bring any precipitation across southwest Kansas at this time. Only a few clouds are expected to be observed throughout this period with dry conditions. Winds will generally be from the west but shift slightly to the north or south as the aforementioned shortwaves move north of southwest Kansas. We will finally begin the slow warming up process Tuesday through Saturday, however the snowpack across much of the region will need to be knocked out quite a bit before we realize maximum potential based on typical downslope mix-down scenarios. && .AVIATION...(For the 12Z TAFS through 12Z Monday morning) ISSUED AT 547 AM CST SUN FEB 9 2014 IFR conditions will be found across the GCK and DDC terminals for the next couple of hours due to lowered visibilities. Thereafter, MVFR conditions look to prevail for the remainder of the day with overcast conditions AOA015. Winds will generally be from the northeast around 10 knots shifting to more of an easterly direction this afternoon. The chance of snow and lowered visibilities is likely this evening as the next system moves in from the west. However, I have left the mention of it out of the TAFs since it is more than 6 hours out of TAF issuance. && .PRELIMINARY POINT TEMPS/POPS... DDC 19 8 15 3 / 20 60 60 20 GCK 19 8 17 5 / 30 60 50 20 EHA 24 12 23 11 / 20 30 30 20 LBL 23 12 20 7 / 20 40 40 20 HYS 17 5 12 -1 / 30 60 40 20 P28 23 9 16 3 / 30 60 60 30 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY until 6 AM CST /5 AM MST/ early this morning FOR KSZ043-044-061>064-074>078-084>088. && $$ SHORT TERM...Gerard LONG TERM...Hovorka_42 AVIATION...Hovorka_42
AREA FORECAST DISCUSSION
NWS TOPEKA KS
514 AM CST Sun Feb 9 2014 ...AVIATION UPDATE... .SHORT TERM...(Today and Tonight) Issued at 327 AM CST SUN FEB 9 2014 Northwest flow is seen to persist on the 09Z water vapor imagery. Profiler data suggest there are a few weak waves within the flow and think this is the main reason for the areas of light snow moving across northern KS early this morning. All of the model guidance continues to point towards a weak band of snow moving across north central and northeast KS through the day today. This appears to be driven mainly be mid level frontogenesis and possibly some weak vorticity advection. Since there is not much disagreement in models, have cautiously bumped up pops with a narrow axis of likely pops from Concordia to Topeka. The progressive nature of the snow and little or no instability suggests amounts will only be around an inch. Surface obs show the latest cold front has pushed through the forecast area and we are seeing dewpoint temps slowly fall. Think this dry air advection will eventually cause the light freezing mist or freezing drizzle across east central KS to come to an end over the next few hours. However temps remain relatively mild behind the immediate wind shift. Because of this have bumped today`s highs up a couple degrees thinking the better cold air advection will occur late in the day and this evening as the arctic ridge really starts to build in. Generally have highs close to or a degree warmer than current readings. With overcast skies and a north wind, I don`t expect temps to see much of a diurnal warm up. So have nearly steady temps for most of the day. Tonight, models suggest another weak wave will move through the area. Although it looks like the better frontogenesis will have set up further south with the band of snow more likely across central and southern KS. Nevertheless will continue with a chance POPs across the southwestern portions of the forecast area. Continued cold air advection as the next arctic ridge builds into the central plains should push lows Monday morning down into the single digits. May need to watch out for some wind chills as north winds remain up around 5 MPH. At this point wind chill readings remain above advisory criteria of -15F. Wolters .LONG TERM...(Monday through Saturday) Issued at 327 AM CST SUN FEB 9 2014 Behind the surface cold front, another reinforcing source of lift is progged to quickly translate eastward from the Colorado Rockies on Monday. Cross sections and profilers suggest the majority of the frontogenetical forcing coinciding with the dendritic ice growth is centered in the 700-500 MB layer. The saturated column remains well below 0C with snow being the primary precip type. Based on the consensus of models tracking the trough axis through central Kansas, light snow is possible over portions of north central and east central areas. Best chances were kept south of Interstate 70 during the morning and early afternoon, gradually tapering off by the evening. The meager amounts of moisture and short duration of maximized lift with this system suggest near a half of an inch or less. The cloud cover and steady cold advection from the 1040 MB arctic ridge hold h85 temps between 10 and 12C below zero at 12Z. This should drop highs back down into the teens. As the ridge axis edges eastward Tuesday, temperatures begin near 0 degrees F before the slow warm up commences. Surface flow becomes southerly as a thermal axis builds over Colorado. Within the very western periphery of the ridge by afternoon, highs should recover to the lower 20s across the area. As this thermal axis begins to migrate eastward Wednesday/Thursday, guidance begins to differ on upper flow pattern resulting in contrasting temperatures. The GFS/ECMWF on Wednesday try to bring a weak and progressive wave southeast across the region. Although consistent for this run, I am not inclined to add precip chances just yet until better consistency between runs is seen. Behind the departing surface trough, a cold front passes southeast Wednesday-Wednesday evening time frame. The recent ECMWF is trending as the outlier, bringing a narrow corridor of much colder air behind the front, while other guidance depicts a embedded trough developing over the northern plains, shunting the colder air eastward. While the ECMWF cannot be completely ruled out, have kept with the consensus blend for now; hesitant to increase temperatures Wednesday-Thursday. For now middle 30s are reasonable for Wednesday highs, increasing to low 40s on Thursday as the h85 thermal axis spreads across the area. On Friday, another strong, but narrow shortwave trough dips southeast into the Mississippi Valley. Decided to remove precip chances for Friday as confidence is too low with both GFS and ECMWF depicting the precip to develop further north and east. Kept highs in the 40s on Friday instead of increasing further, as cloud cover from the upper wave may hinder the warmer bias. Lastly on Saturday, winds begin to shift back towards the north as a cold front enters from Nebraska. Timing appears late in the day, still allowing for highs to reach the low to middle 40s. && .AVIATION...(For the 12Z TAFs through 12Z Monday Morning) Issued at 514 AM CST SUN FEB 9 2014 Dry air advection has started to erode away at the MVFR CIGS. However think MVFR conditions may move back in with models still showing a band of light snow forming near the terminals. Until the band forms, do not have enough confidence to mention IFR conditions, but if the RAP is correct there may be some due to moderate snowfall. This will need to be monitored. Otherwise think conditions will generally be improving due to continued dry air advection once the band of snow moves east. Overnight, models are showing the better frontogenesis setting up to the southwest of the terminals, so will not mention any snow overnight and think VFR conditions will prevail. This is contingent on the second band of snow remaining to the southwest. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...Wolters LONG TERM...Bowen AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS CARIBOU ME
612 AM EST SUN FEB 9 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF TO THE EAST TODAY WHILE LOW PRESSURE MOVES IN FROM NEW YORK STATE TONIGHT. THIS LOW PRESSURE WILL TRACK SOUTHEAST OF THE REGION ON MONDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION THROUGH MID WEEK. && .NEAR TERM /THROUGH TONIGHT/... 607 AM UPDATE...ADJUSTED THE SKY CONDITIONS TO ACCOUNT FOR SOME MOVING ACROSS NORTHERN MAINE THIS MORNING. THIS IN RESPONSE TO 35KT JET STREAK AT 700MBS. THIS IS PICKED UP WELL ON THE IR SATELLITE IMAGERY W/A BAND OF ENHANCED CLOUDS MOVING ACROSS NORTHERN AND WESTERN MAINE. THESE CLOUDS WILL PULL OUT THIS MORNING W/SUNSHINE RETURNING. CLOUDS WILL INCREASE FROM SW TO NE. STRONG LLVL INVERSION AS SEEN FROM THE LATEST LAPS SOUNDINGS HAS SETUP. TEMPERATURES HAVE BOTTOMED OUT EVEN MORE W/READINGS ATTM ACROSS THE NORTHERN AND WESTERN AREAS NEAR 20 BELOW W/EVEN 10-15 AROUND THE ST. JOHN VALLEY AND THE CARIBOU- PRESQUE ISLE REGION. THE HRRR HAS BEEN CONSISTENT IN SHOWING LLVL MOISTURE THIS MORNING. THIS MOISTURE SHOULD BURN OFF AND LIFT AFTER SUNRISE W/THE INVERSION BREAKING. TEMPERATURES WILL WARM TODAY BUT STILL REMAIN BELOW NORMAL FOR EARLY FEBRUARY. DECIDED TO PUSH BACK THE ARRIVAL OF SNOW UNTIL THIS EVENING. THE LATEST RAP MODEL WAS HANDLING THE PRECIP SHIELD WELL PER 06Z ANALYSIS. THE LATEST MODEL SOUNDINGS INCLUDING THE GFS AND NAM SHOW THE COLUMN MOISTENING UP THROUGH 500MBS THIS EVENING INTO THE OVERNIGHT HRS. THIS MOISTURE WILL BE IN RESPONSE TO LOW PRES MOVING ACROSS THE GULF OF MAINE FROM NYS. THIS MOISTURE IS SHOWN TO MAKE ITS WAY UP INTO THE CROWN OF MAINE ESPECIALLY W/THE GFS. THE BEST LIFT AND ANY FRONTOGENETICAL FORCING WILL BE FROM THE CENTRAL HIGHLANDS(SOUTHERN PISCATAQUIS COUNTY) ALL TO WAY TO THE COAST. SNOW RATIOS WILL MAKE SNOWFALL A CHALLENGE AS THEY WILL BE ON THE ORDER OF 18-22:1 & QPF LESS THAN 0.25 INCHES. ATTM, THE DECISION HERE WAS TO STAY W/THE DAYCREW`S ASSESSMENT OF THE BEST SNOWFALL WILL BE ACROSS THE DOWNEAST AND ESPECIALLY THE COAST WHERE TOTALS BY MONDAY COULD HIT 3-4 INCHES. DECIDED ON NO ADVISORY ATTM SINCE THIS EVENT WILL STRETCH INTO MONDAY. SINCE TEMPERATURES WILL BE HELD UP AFTER FALLING OFF THIS EVENING ESPECIALLY ACROSS NORTHERN AREAS. READINGS ACROSS THE FAR NORTH SUCH AS THE ST. JOHN VALLEY COULD DROP BACK TO BELOW ZERO BEFORE LEVELING OFF W/THE INCREASING CLOUDS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... A WEAK AREA OF LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE EARLY MONDAY. LIGHT SNOW WILL TAPER TO SNOW SHOWERS EARLY MONDAY AS THE LOW MOVES EAST. SNOW ACCUMULATIONS THROUGH MONDAY WILL RANGE FROM 1 TO 3 INCHES ACROSS DOWNEAST MAINE WITH LESSER AMOUNTS ACROSS THE REMAINDER OF NORTHERN MAINE. HIGH PRESSURE WILL THEN BEGIN TO BUILD EAST ACROSS THE REGION MONDAY NIGHT THROUGH TUESDAY. EXPECT DECREASING CLOUDS MONDAY NIGHT AND PARTLY/MOSTLY SUNNY SKIES TUESDAY. TEMPERATURES WILL BE BELOW NORMAL BOTH MONDAY AND TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE WILL BUILD EAST TUESDAY NIGHT THROUGH WEDNESDAY. THE HIGH WILL THE MOVE EAST WEDNESDAY NIGHT. EXPECT MAINLY CLEAR SKIES TUESDAY NIGHT AND MOSTLY SUNNY SKIES ON WEDNESDAY. THE HIGH WILL MOVE EAST WEDNESDAY NIGHT AND THURSDAY. A LOT OF UNCERTAINTY STILL EXISTS WITH REGARD TO THE FORECAST FOR THE LATTER HALF OF THE WEEK. LATEST OPERATIONAL RUN OF THE GFS SHOWS LOW PRESSURE TRACKING NORTHEAST FROM THE SOUTHEASTERN U.S. THURSDAY AND PASSING WELL TO THE SOUTH OF NOVA SCOTIA THURSDAY NIGHT THROUGH FRIDAY. THE LATEST EC TRACKS THE LOW NORTHEAST ALONG THE EASTERN SEABOARD LATER WEDNESDAY NIGHT AND UP ALONG THE MAINE COAST LATE THURSDAY AND NORTHEAST THROUGH THE MARITIMES ON FRIDAY. THE EC IS BY FAR AN OUTLIER COMPARED TO OTHER MODEL GUIDANCE. THAT BEING SAID...HAVE NOT DEVIATED FROM SUPERBLEND POPS THROUGH THE EXTENDED PERIOD. && .AVIATION /11Z SUNDAY THROUGH THURSDAY/... NEAR TERM: VFR ATTM TODAY. THERE COULD BE BRIEF MVFR/IFR CONDITIONS MAINLY FOR THE NORTHERN TERMINALS SUCH KQPI AND KFVE. CONDITIONS WILL DETERIORATE ACROSS THE DOWNEAST AND THE COAST LATER TONIGHT W/KBGR AND KBHB SEEING MVFR AND PERHAPS IFR BY MONDAY MORNING. SHORT TERM: MVFR/IFR POSSIBLE IN -SN EARLY MONDAY...THEN MAINLY VFR THROUGH WEDNESDAY NIGHT. MVFR/IFR POSSIBLE IN PRECIPITATION THURSDAY BUT CONFIDENCE IS LOW. && .MARINE... NEAR TERM: NO HEADLINES EXPECTED. WINDS WILL AVERAGE 10-15 KTS W/SEAS RUNNING 2-3 FT RIGHT INTO TONIGHT. CONTINUED THE MENTION OF FREEZING SPRAY THIS MORNING AND AGAIN TONIGHT. SHORT TERM: WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH MOST OF THE LONG TERM. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT/DUDA MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
703 AM EST SUN FEB 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM EST SUN FEB 9 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER THE UPR LKS TO THE SW OF CORE OF ARCTIC AIR SITUATED OVER QUEBEC. RIBBON OF MUCH STRONGER W FLOW IS EVIDENT OVER THE S 2/3 OF THE CONUS. A FAIRLY STRONG DISTURBANCE EMBEDDED IN THIS FASTER FLOW IS MOVING THRU CENTRAL WI EARLY THIS MRNG. ACCOMPANYING PCPN HAS REACHED AS FAR N AS GRB OR SO...BUT OVERALL DRY AIRMASS IN PLACE WITH PWAT NO HIER THAN 0.10 TO 0.15 INCH IS LIMITING THE IMPACT OVER UPR MI TO JUST SOME MID CLD DESPITE PRESENCE OF AREA OF ACCOMPANYING H85-5 QVECTOR CNVGC. LGT WINDS AND LO PWAT HAVE ALLOWED TEMPS TO FALL BLO ZERO AT MOST PLACES DESPITE THESE CLDS. THERE ARE SOME LK CLDS NEAR SUPERIOR WITH H85 TEMPS ARND -20C DESPITE LGT NW FEED OF DRY LLVL AIR SHOWN ON THE 00Z INL RAOB AND EXTENSIVE ICE COVER. THE MQT RADAR DOES SHOW A FEW HIER RETURNS OVER SCENTRAL LK SUP...SO THERE ARE PROBABLY SOME ISOLD -SHSN DESPITE THESE NEGATIVES FOR LES. LOOKING UPSTREAM...THERE IS A SHRTWV OVER SW SASKATCHEWAN AND ANOTHER DROPPING SWD NEAR LK WINNIPEG. MAIN FCST CONCERNS IN THE SHORT TERM ARE LIMITED POPS ASSOCIATED WITH ARRAY OF SHRTWVS MENTIONED ABOVE AND TEMPS. TODAY..AREA OF QVECTOR CNVGC ASSOCIATED WITH SHRTWV MOVING TO THE S IS FCST TO MOVE E THIS MRNG AND EXIT THE AREA SOON AFTER SUNRISE. SO ACCOMPANYING MID CLD COVER SHOULD SHIFT TO THE E AS DRIER MID LVL AIR FOLLOWS. BUT THE SHRTWV OVER SW SASKATCHEWAN IS FCST TO TRACK INTO SCENTRAL WI LATE THIS AFTN...WITH AREA OF H85-5 QVECTOR CNVGC ARRIVING THIS AFTN OVER UPR MI. GIVEN THE ABSENCE OF ANY MSTR INFLOW WITH LLVL NW FLOW IN THE WAKE OF DEPARTING FIRST DISTURBANCE... SUSPECT THE IMPACT FOR THE CWA WL BE THE SAME AS WHAT IS HAPPENING NOW...JUST SOME MID CLD. SO HAVE OPTED TO REMOVE POPS...AT LEAST AWAY FM LK SUP. THE MAIN CONCERN IS HOW MUCH LK EFFECT PCPN THERE MAY OR MAY NOT BE. MOST OF THE HI RES MODELS ARE SHOWING NO PCPN NEAR THE LK THRU THE DAY...WITH ICE COVER...ABSENCE OF CYC FLOW /IN FACT SHOWING ACYC FLOW/...AND LLVL DRY ADVECTION SUPPRESSING THIS ACTIVITY. ON THE OTHE HAND...THE LOWER RES GFS/ECMWF LIGHT QPF SUGGEST SOME SHSN IN THE NW WIND SN BELTS. THE GFS ICE ANALYSIS DOES SHOW A REASONABLE AMOUNT OF OPEN WATER OVER CENTRAL LK SUP WHILE THE NAM/GEM INDICATE A COMPLETELY COVERED LK. SINCE THERE HAVE BEEN SOME BREAKS IN THE ICE RECENTLY AND THERE ARE AND HAVE BEEN SOME LGT SHSN AS WELL...WL TEND TOWARD THE LO RES MODELS AND INCLUDE SOME LO CHC POPS IN THE FAVORED SN BELTS THRU THE DAY AS THE LLVL NW FLOW DROPS H85 TEMPS TO ARND -23C BY 00Z MON OVER THE W. THIS CAD SHOULD KEEP MAX TEMPS LOWER THAN YDAY...WITH THE HIER TEMPS OVER THE SCENTRAL WITH SOME DOWNSLOPE FLOW AND PROBABLY SOME SUNSHINE BTWN THE SHRTWVS. TNGT...SHRTWV NOW NEAR LK WINNIPEG IS PROGGED TO DROP SEWD AND OVER UPR MI BY 12Z MON AS WI DISTURBANCE SHIFTS INTO THE LOWER LKS. THIS QUICK PROGRESSION OF SHRTWVS IS FCST TO MAINTAIN SOME DEEP LYR QVECTOR CNVGC THRU THE NGT...SO THERE WL PROBABLY BE QUITE A BIT OF AT LEAST MID/HI CLD EVEN OVER THE INTERIOR EVEN THOUGH LLVL DRYING SHOULD PREVENT ANY PCPN THERE. CLOSER TO LK SUP...WL MAINTAIN SOME LOWER CHC POPS FOR LES WITH H85 TEMPS FALLING TOWARD -24C DESPITE FCST NEUTRAL/ACYC NW FLOW AND CONSIDERABLE ICE COVER. THE GFS SHOWS STRONGER LLVL WINDS THAN THE OTHER MODELS...BUT OUT OF PHASE SHRTWVS/EXTENSIVE ICE COVER THAT WL LIMIT PRES FALLS OVER THE OPEN WATER AND SHARPNESS OF THE PRES GRADIENT INDICATE THE WEAKER WINDS SHOWN BY THE BULK OF THE OTHER GUIDANCE ARE ON THE RIGHT TRACK. THIS DIFFERENCE IN WIND SPEEDS COULD BE CRITICAL IN DETERMINING WHETHER WIND CHILLS WL REACH ADVY THRESHOLDS AS SFC TEMPS FALL WELL BLO ZERO...ESPECIALLY OVER THE W HALF. WITH THE WEAKER WINDS...EXPECT NEITHER THE WIND CHILLS NOR THE WIND SPEEDS WL BE SUFFICIENT FOR AN ADVY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 303 AM EST SUN FEB 9 2014 AFTER STARTING THE LONG TERM PERIOD UNDER A COLD NORTHERN STREAM TROUGH...IT/S DEPARTURE ON MONDAY NIGHT WILL LEAD TO A MORE PROGRESSIVE AND WARMER PATTERN FOR THE REST OF THE WORK WEEK AND INTO NEXT WEEKEND. WITH COLD 850MB TEMPS (-24C) UNDER THE UPPER TROUGH ON MONDAY...THERE WILL BE PLENTY OF OVER LAKE INSTABILITY FOR LAKE EFFECT IN THE AREAS THAT HAVE OPEN WATER. BUT MODIS SATELLITE FROM TODAY SHOWS THAT THOSE AREAS ARE VERY LIMITED...BUT THERE WERE STILL PERIODS OF CLOUDS AND LIGHT LAKE EFFECT OVER THE LAST DAY. THUS...WILL CONTINUE TO FOLLOW PREVIOUS SHIFTS OF SLIGHT AND CHANCE POPS IN THE NORTHWEST WIND FAVORED LOCATIONS DURING THE DAY ON MONDAY. WITH THE AMOUNT OF COLD AIR PRESENT...ALONG WITH LIMITED OPEN WATER...DON/T THINK SNOW WILL AMOUNT TO MUCH...UNLESS SOME WATER OPENS UP MORE THAN CURRENTLY SEEN. SINCE THERE WILL BE ABUNDANT MOISTURE ROTATING THROUGH THE CWA (CURRENTLY BETWEEN LAKE WINNIPEG AND HUDSON BAY)...WILL GO WITH MOSTLY CLOUDY SKIES OVER MUCH OF THE CWA. MONDAY WILL BE ONE OF THE COLDER DAYS FOR THE FORESEEABLE FUTURE...WITH HIGHS OVER THE WEST IN THE LOW SINGLE DIGITS ABOVE ZERO AND MID-UPPER SINGLE DIGITS ELSEWHERE. UPPER TROUGH WILL QUICKLY SHIFT EAST ON MONDAY NIGHT AND ALLOW RIDGING TO BUILD INTO THE AREA AT THE SURFACE AND ALOFT. THE SURFACE RIDGE...FROM THE HIGH SLIDING THROUGH THE UPPER MISSISSIPPI VALLEY...WILL LEAD TO DRIER AIR...WARMING ALOFT...AND WEAKENING/BACKING WINDS WHICH WILL DIMINISH THE SNOW CHANCES FROM WEST TO EAST THROUGH THE NIGHT AND INTO TUESDAY MORNING. WITH THE DRY RIDGE MOVING IN ON MONDAY NIGHT...SHOULD SEE INLAND TEMPERATURES REALLY FALL WERE SKIES CLEAR OUT. GOING FORECAST HAS OVERNIGHT LOWS NEAR THE WISCONSIN BORDER NEAR -20F AND THAT SEEMS FAIRLY REASONABLE. DIDN/T MAKE MANY CHANGES TO THOSE VALUES...SINCE SOME OF THE COLDER MODELS EVEN HAVE VALUES AROUND -24F AND BASED OFF SOME OF THE COLD SPOTS THE LAST COUPLE NIGHTS IT DOESN/T SEEM TOO UNREASONABLE. WITH TEMPERATURES THIS COLD...IT WON/T TAKE MUCH FOR WIND CHILLS TO NOSE INTO THE ADVISORY CRITERIA. BUT WITH WINDS LOOKING TO BE WELL BELOW 10MPH...SHOULD NOT NEED A WIND CHILL ADVISORY. THE HIGH PRESSURE RIDGE WILL SHIFT EAST OF THE REGION ON TUESDAY AND LEAD TO SOUTHWESTERLY FLOW DEVELOPING OVER THE AREA. THIS WILL START A WARMING TREND THAT WILL BRING TEMPERATURES CLOSER...BUT STILL BELOW NORMAL...FOR THE REST OF THE WORK WEEK. THE FIRST IN A SERIES OF SHORTWAVE TO AFFECT THE REGION IN THE NEARLY ZONAL FLOW WILL MOVE THROUGH THE UPPER GREAT LAKES ON TUESDAY NIGHT. SOME DISCREPANCY IN THE MODELS ON THE WHERE THE PIECES OF ENERGY TRACK...BUT THE GENERAL IDEA IS FOR SOME ENERGY TO MOVE THROUGH ON TUESDAY NIGHT AND THEN A COLD FRONT ASSOCIATED WITH A LOW OVER HUDSON BAY TO SWEEP THROUGH ON WEDNESDAY. HAVE FOLLOWED THAT IDEA FOR A WEST TO EAST PUSH OF CHANCE POPS THROUGH THE CWA. OVERALL...LOOKS LIKE A DUSTING TO 2 INCHES OF SNOW ON TUESDAY NIGHT AND WEDNESDAY. THE NEXT SHORTWAVE MOVES THROUGH THE NORTH CENTRAL CONUS ON THURSDAY AND ONCE AGAIN THERE ARE DIFFERENCES IN THE MODELS. THIS TIME...THE GFS/GEM ARE IN DECENT AGREEMENT WITH THE SHORTWAVE INTENSIFYING THE LOW MOVING THROUGH THE NORTHERN PLAINS AND TRACKING IT THROUGH THE UPPER GREAT LAKES THURSDAY AND THURSDAY NIGHT. THE ECMWF ON THE OTHER HAND TRACKS A WEAKER LOW FARTHER SOUTH AND SLOWER THROUGH THE LOWER GREAT LAKES. ALL IN ALL...IT APPEARS THAT THERE WILL BE SOME DISTURBANCE AFFECTING THE AREA DURING THE SECOND HALF OF THE WORK WEEK. WITH THE TRADITIONAL FASTER GFS AND SLOWER ECMWF SOLUTIONS USUALLY MERGING AND SPLITTING THE DIFFERENCES...THINK THE AREA WILL POTENTIALLY EXPERIENCE NEAR ADVISORY SNOWFALL AROUND THE THURSDAY INTO THURSDAY NIGHT PERIOD. WILL KEEP POPS AT THE CHANCE CATEGORY UNTIL MODELS COME INTO BETTER AGREEMENT ON THE TIMING. BEHIND THAT DISTURBANCE...MODELS SHOW A HIGH PRESSURE RIDGE MOVING INTO THE AREA AND PRODUCE A DRY FRIDAY BEFORE ANOTHER SHORTWAVE APPROACHES WISCONSIN ON SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 701 AM EST SUN FEB 9 2014 COLD NW FLOW AND PASSING DISTURBANCES WL BRING A GOOD DEAL OF LO CLD THIS FCST PERIOD ALONG WITH SOME GENERALLY LGT SHSN...THE INTENSITY OF WHICH WL BE LIMITED BY EXTENSIVE ICE ON LK SUP AND RELATIVELY DRY LLVL AIR UPSTREAM OF THE WATER. ALTHOUGH THIS DRY AIR WL CAUSE PERIODS OF VFR CONDITIONS...EXPECT MVFR CIGS TO PREDOMINATE UNDER FAIRLY LO INVRN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 335 AM EST SUN FEB 9 2014 WITH A RELATIVELY WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES THRU MID WEEK...EXPECT WINDS UNDER 20 KTS MOST OF THE TIME. THE BEST CHANCE FOR STRONGER WINDS WILL BE ON MON...WHEN NW WINDS MAY BE AS HI AS 25 KTS AHEAD OF HI PRES MOVING INTO THE UPPER MISSISSIPPI RIVER VALLEY. A STRONGER S-SW WIND UP TO 25 KTS MAY IMPACT PORTIONS OF THE LAKE ON TUE NIGHT UNDER THE SHARPENING PRES GRADIENT BETWEEN THIS DEPARTING HI MOVING INTO THE MID ATLANTIC STATES AND A LO PRES TROF APPROACHING FROM THE W. ALTHOUGH VERY COLD AIR WILL LINGER THRU TUE...EXPECT LITTLE POTENTIAL FOR FREEZING SPRAY WITH THE EXTENSIVE ICE COVER ON THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1000 AM EST SUN FEB 9 2014 .SYNOPSIS... A FAST MOVING UPPER DISTURBANCE WILL BRING A BRIEF PERIOD OF SNOW THIS MORNING AND MOVE OFF TO THE EAST BY EARLY AFTERNOON. THEN ANOTHER SURGE OF ARCTIC AIR WILL SPREAD ACROSS THE REGION FOR THE FIRST HALF OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FORCING ASSOCIATED WITH A SHORTWAVE AND WEAK SURFACE TROUGH HAS LED TO WIDESPREAD SNOW ACROSS THE NWS ILN FORECAST AREA. WEAK FRONTOGENESIS ON THE BACK SIDE OF THE SURFACE TROUGH (WHERE COLD ADVECTION IS BEGINNING) HAS LED TO SOME SMALL AREAS OF ENHANCEMENT. ONE BAND THAT SET UP ACROSS THE NORTH-CENTRAL FORECAST AREA PRODUCED VISIBILITIES OF 1/4 MILE AND QUICK ACCUMULATIONS OF TWO (EVEN UP TO THREE) INCHES. ASIDE FROM JUST THE SNOW...VISIBILITIES ARE LOW AROUND THE AREA ANYWAY...WITH SOME MIST OR FOG ALSO PRESENT. WITH THE ATMOSPHERE BECOMING MORE SATURATED AS THE SNOW HAS BEGUN...FREEZING DRIZZLE APPEARS TO HAVE ENDED. THE HRRR HAS PICKED UP ON THE ENHANCED AREA OF SNOW OVER SOUTH- CENTRAL OHIO QUITE NICELY...AND SNOWFALL TOTALS HAVE BEEN INCREASED FOR THESE LOCATIONS. OTHERWISE...ADJUSTMENTS TO THE FORECAST WERE MINOR. THE BACK EDGE OF THE STEADY SNOWFALL IS NOW ENTERING THE ILN CWA...THOUGH FLURRIES ARE NOTED ON SURFACE OBS THROUGHOUT MOST OF INDIANA. PREVIOUS DISCUSSION > FREEZING DRIZZLE WILL START OUT THE NEAR TERM. SNOW EXTENDING FROM NORTHERN INDIANA INTO CENTRAL ILLINOIS WILL QUICKLY MAKE ITS WAY ACROSS THE FORECAST AREA THIS MORNING AND THEN CLEAR OFF TO THE EAST BY EARLY AFTERNOON. ACCUMULATIONS WILL BE GREATEST NORTH OF I-70 WHERE FORCING IS A BIT BETTER AND SNOW MAY LAST FOR SEVERAL HOURS. EXPECT 1 TO 2 INCHES THERE. FURTHER SOUTH SNOW WILL ONLY OCCUR FOR A BRIEF TIME AND MAY NOT EVEN MAKE IT INTO NORTHERN KENTUCKY. ACCUMULATIONS WILL BE LESS HEADING SOUTH WITH ONLY A DUSTING NEAR THE OHIO RIVER. HIGHS FORECAST CLOSE TO MOS CONSENSUS. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THE SHORT TERM BRINGING ANOTHER REINFORCEMENT OF ARCTIC AIR. ANOTHER FAST MOVING IMPULSE TONIGHT SHOULD BE SUPPRESSED SOUTH OF THE FORECAST AREA ALTHOUGH HAVE LEFT SLIGHT CHANCE POPS IN THE FAR SOUTHERN COUNTIES. OTHERWISE IT WILL BE DRY. HAVE GENERALLY TRENDED TEMPERATURES TOWARDS COLDER GFS MOS. WITH COLD TEMPERATURES AND EVEN JUST LIGHT WINDS CONTINUING INTO THE NIGHTTIME PERIODS... WIND CHILL VALUES WILL BE NEAR OR BELOW WIND CHILL ADVISORY THRESHOLD FOR NORTHERN COUNTIES MONDAY NIGHT. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS SHOWING QUITE A BIT OF VARIABILITY IN TIMING AND AMPLIFICATION OF SHORT WAVES THROUGHOUT THE LONG TERM. THERE REMAINS THE POTENTIAL FOR SYSTEM PASSING JUST SOUTHEAST OF THE FORECAST AREA LATE WEDNESDAY INTO THURSDAY. IT DOES APPEAR THAT A COLD FRONT WILL MOVE THROUGH LATER IN THE WEEK ALTHOUGH THERE IS TIMING UNCERTAINTY WHETHER POTENTIAL IMPACTS WILL BE THURSDAY OR FRIDAY. THERE IS BROAD AGREEMENT THAT ANOTHER SYSTEM WILL PUSH THROUGH THE REGION ON SATURDAY. TEMPERATURES SHOULD BE ABLE TO MODERATE ALTHOUGH STILL REMAIN SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF THE WEEK. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... FREEZING DRIZZLE WILL START OUT THE TAF PERIOD ACROSS THE TAF SITES. EXPECT PRECIPITATION TO TRANSITION TO SNOW THIS MORNING BEFORE TAPERING OFF AROUND THE MIDDLE OF THE DAY. DRY CONDITIONS CAN THEN BE EXPECTED FOR THE REMAINDER OF THE TAF PERIOD. VSBYS WILL BE REDUCED WITH THE PRECIPITATION THIS MORNING TO THE MVFR AND IFR CATEGORIES. CIGS ARE GENERALLY IN THE IFR TO LIFR CATEGORIES THIS MORNING. CIGS WILL IMPROVE BY THIS AFTERNOON WITH VFR CONDITIONS RETURNING BY THE LATE AFTERNOON HOURS. SOME ADDITIONAL LOWER CLOUDS WILL WORK INTO THE SOUTHERN TAF SITES KCVG AND KLUK DURING THE FIRST PART OF THE NIGHT TONIGHT ALLOWING FOR A RETURN TO MVFR CONDITIONS. OUTLOOK...MVFR CEILINGS AND VSBYS POSSIBLE THURSDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS... NEAR TERM...HATZOS SHORT TERM... LONG TERM... AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
848 AM CST SUN FEB 9 2014 .UPDATE... A quick forecast update was sent out to bring current temperatures back in line with recent trends. Temperatures remain near freezing along the I-10 corridor with a mixture of 30s and 40s across most of the remaining counties. However, the leading edge of a strong cold front has moved into the Big Country, dropping temperatures to near 30 degrees across Haskell, Throckmorton, and Shackelford Counties. We continue to receive reports of freezing fog across this area but as temperatures slowly warm, the potential for additional ice accumulations will decrease. Visibilities should slowly improve so no dense fog advisory will be issued. I also increased sky cover to account for the increase in high clouds. Max temps were left alone for now but I`ll continue to watch the progress of the cold front and adjust forecast temperatures as needed. Johnson && .PREV DISCUSSION... /ISSUED 600 AM CST SUN FEB 9 2014/ AVIATION... /12Z TAFS/ VFR conditions are expected today at the TAF sites. An initial cold front will sag south to KABI 17Z-18Z, resulting in a shift to northeast winds 5-10 KT. Any fog this morning and low cloud cover today are expected to remain north of Abilene. For the other TAF sites, winds today will be generally southwest at 6-12 KT. A reinforced cold front will push south across central and southern sections of West Central Texas tonight. The front should arrive at KSJT 02-03Z, and should reach the Interstate 10 corridor 07Z-08Z. Winds will shift to the northeast with the frontal passage. A degradation of conditions from VFR to IFR and possibly LIFR is expected, from north to south tonight. This will occur as low cloud cover expands to the south behind the front, with areas of drizzle and freezing drizzle developing. 19 PREV DISCUSSION... /ISSUED 459 AM CST SUN FEB 9 2014/ SHORT TERM... (Today and Tonight) A nearly stationary surface boundary extends from the eastern Texas Panhandle south to just northeast of Jayton, then east across Haskell and Throckmorton Counties. Temperatures are colder behind east/north of this boundary, where low cloudiness has filled in with areas of freezing fog. A strong cold front is moving south across Kansas. The NAM12 and RUC13 models appear to have the best handle on this boundary...and have it sagging south as a cold front to the Interstate 20 corridor by 11 AM to Noon, and then drifting a little farther south early this afternoon. Meanwhile, the aforementioned strong cold front will quickly move south today, entering the Big Country this afternoon and overtaking the lead boundary by late afternoon or evening. Carrying the inherited mention of fog early this morning across the area roughly north of a Rotan to Albany line, with freezing fog in the northern parts of Haskell and Throckmorton Counties where temperatures are at or just below freezing. With the marginally freezing temperatures and visibility with the fog to stay above one mile, not expecting any road ice problems this morning aross that area. Low cloud cover will be persistent through the day today across Haskell and Throckmorton counties. Temperature forecast today is tricky across the Big Country (area along/north of Interstate 20) with the initial frontal boundary. Made reductions across that area, where highs should be reached early this afternoon before temperatures level off and then slowly drop. Highs across that area are expected to range from the upper 30s/near 40 in Haskell and Throckmorton Counties, to the mid to upper 50s along Interstate 20 and 60s just south of I-20. Farther to the south, temperatures will be warm again today, with afternoon highs in the 70s to near 80 with mostly sunny skies. This evening and tonight, the reinforced cold front will push south through our central and southern counties, reaching the Interstate 10 corridor by 2 AM. Model boundary layer moisture fields indicate extensive low cloud cover developing south across West Central Texas behind the cold front, with areas of drizzle developing. With strong cold air advection, temperatures will drop to below freezing tonight across our northern and central counties, to the mid/upper 30s along and south of Interstate 10. With a weak overrunning pattern setting up and given the extent of boundary layer moistening, carrying areas of drizzle and freezing drizzle tonight until mid-morning Monday, with freezing drizzle mentioned where temperatures drop below freezing. 19 LONG TERM... (Monday night through Sunday) .Winter precipitation possible Monday night and Tuesday... A cold surface ridge will be entrenched across the area Monday into Tuesday with temperatures remaining well below normal. An upper level trough will approach the area on Monday and move across the area on Tuesday. Still looks like the best chance for precipitation will be on Tuesday when lift from the upper trough will be greatest. Temperatures will be cold Monday and Tuesday with highs both days in the 30s across much of the area with the exception of far southern counties where some low to mid 40s are expected. Temperatures will fall into the 20s areawide Monday night. Made only minor changes to the forecast Monday night and Tuesday, mainly for precipitation type. Model forecast soundings continue to show a substantial warm layer aloft for much of this time period and a lack of moisture within the dendritic growth zone. This type of profile will favor a combination of freezing rain and sleet Monday night into Tuesday morning, with rain across southern sections and a winter mix across northern sections by Tuesday afternoon. Profiles due appear a bit more favorable for some snow to mix in mainly north of I-20 on Tuesday. At the present time, precipitation amounts are expected to be very light for this event, generally one tenth inch or less water equivalent with only minor snow and ice accumulations. Dry and warmer weather returns to the area Wednesday through Saturday with above normal temperatures through the period. The only mentionable feature will be a weak front on Saturday, with only slightly cooler temperatures into Sunday. 24 && .PRELIMINARY POINT TEMPS/POPS... Abilene 57 25 36 23 37 / 5 10 10 20 30 San Angelo 79 30 41 26 39 / 0 10 10 20 30 Junction 79 37 45 29 42 / 0 10 20 20 30 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 25
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
600 AM CST SUN FEB 9 2014 .AVIATION... /12Z TAFS/ VFR conditions are expected today at the TAF sites. An initial cold front will sag south to KABI 17Z-18Z, resulting in a shift to northeast winds 5-10 KT. Any fog this morning and low cloud cover today are expected to remain north of Abilene. For the other TAF sites, winds today will be generally southwest at 6-12 KT. A reinforced cold front will push south across central and southern sections of West Central Texas tonight. The front should arrive at KSJT 02-03Z, and should reach the Interstate 10 corridor 07Z-08Z. Winds will shift to the northeast with the frontal passage. A degradation of conditions from VFR to IFR and possibly LIFR is expected, from north to south tonight. This will occur as low cloud cover expands to the south behind the front, with areas of drizzle and freezing drizzle developing. 19 && .PREV DISCUSSION... /ISSUED 459 AM CST SUN FEB 9 2014/ SHORT TERM... (Today and Tonight) A nearly stationary surface boundary extends from the eastern Texas Panhandle south to just northeast of Jayton, then east across Haskell and Throckmorton Counties. Temperatures are colder behind east/north of this boundary, where low cloudiness has filled in with areas of freezing fog. A strong cold front is moving south across Kansas. The NAM12 and RUC13 models appear to have the best handle on this boundary...and have it sagging south as a cold front to the Interstate 20 corridor by 11 AM to Noon, and then drifting a little farther south early this afternoon. Meanwhile, the aforementioned strong cold front will quickly move south today, entering the Big Country this afternoon and overtaking the lead boundary by late afternoon or evening. Carrying the inherited mention of fog early this morning across the area roughly north of a Rotan to Albany line, with freezing fog in the northern parts of Haskell and Throckmorton Counties where temperatures are at or just below freezing. With the marginally freezing temperatures and visibility with the fog to stay above one mile, not expecting any road ice problems this morning aross that area. Low cloud cover will be persistent through the day today across Haskell and Throckmorton counties. Temperature forecast today is tricky across the Big Country (area along/north of Interstate 20) with the initial frontal boundary. Made reductions across that area, where highs should be reached early this afternoon before temperatures level off and then slowly drop. Highs across that area are expected to range from the upper 30s/near 40 in Haskell and Throckmorton Counties, to the mid to upper 50s along Interstate 20 and 60s just south of I-20. Farther to the south, temperatures will be warm again today, with afternoon highs in the 70s to near 80 with mostly sunny skies. This evening and tonight, the reinforced cold front will push south through our central and southern counties, reaching the Interstate 10 corridor by 2 AM. Model boundary layer moisture fields indicate extensive low cloud cover developing south across West Central Texas behind the cold front, with areas of drizzle developing. With strong cold air advection, temperatures will drop to below freezing tonight across our northern and central counties, to the mid/upper 30s along and south of Interstate 10. With a weak overrunning pattern setting up and given the extent of boundary layer moistening, carrying areas of drizzle and freezing drizzle tonight until mid-morning Monday, with freezing drizzle mentioned where temperatures drop below freezing. 19 LONG TERM... (Monday night through Sunday) ..Winter precipitation possible Monday night and Tuesday... A cold surface ridge will be entrenched across the area Monday into Tuesday with temperatures remaining well below normal. An upper level trough will approach the area on Monday and move across the area on Tuesday. Still looks like the best chance for precipitation will be on Tuesday when lift from the upper trough will be greatest. Temperatures will be cold Monday and Tuesday with highs both days in the 30s across much of the area with the exception of far southern counties where some low to mid 40s are expected. Temperatures will fall into the 20s areawide Monday night. Made only minor changes to the forecast Monday night and Tuesday, mainly for precipitation type. Model forecast soundings continue to show a substantial warm layer aloft for much of this time period and a lack of moisture within the dendritic growth zone. This type of profile will favor a combination of freezing rain and sleet Monday night into Tuesday morning, with rain across southern sections and a winter mix across northern sections by Tuesday afternoon. Profiles due appear a bit more favorable for some snow to mix in mainly north of I-20 on Tuesday. At the present time, precipitation amounts are expected to be very light for this event, generally one tenth inch or less water equivalent with only minor snow and ice accumulations. Dry and warmer weather returns to the area Wednesday through Saturday with above normal temperatures through the period. The only mentionable feature will be a weak front on Saturday, with only slightly cooler temperatures into Sunday. 24 && .PRELIMINARY POINT TEMPS/POPS... Abilene 57 25 36 23 37 / 5 10 10 20 30 San Angelo 79 30 41 26 39 / 0 10 10 20 30 Junction 79 37 45 29 42 / 0 10 20 20 30 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
600 AM CST Sun Feb 9 2014 .AVIATION... /12Z TAFS/ VFR conditions are expected today at the TAF sites. An initial cold front will sag south to KABI 17Z-18Z, resulting in a shift to northeast winds 5-10 KT. Any fog this morning and low cloud cover today are expected to remain north of Abilene. For the other TAF sites, winds today will be generally southwest at 6-12 KT. A reinforced cold front will push south across central and southern sections of West Central Texas tonight. A degradation of conditions is expected through the night, from north to south. && .PREV DISCUSSION... /ISSUED 459 AM CST SUN FEB 9 2014/ SHORT TERM... (Today and Tonight) A nearly stationary surface boundary extends from the eastern Texas Panhandle south to just northeast of Jayton, then east across Haskell and Throckmorton Counties. Temperatures are colder behind east/north of this boundary, where low cloudiness has filled in with areas of freezing fog. A strong cold front is moving south across Kansas. The NAM12 and RUC13 models appear to have the best handle on this boundary...and have it sagging south as a cold front to the Interstate 20 corridor by 11 AM to Noon, and then drifting a little farther south early this afternoon. Meanwhile, the aforementioned strong cold front will quickly move south today, entering the Big Country this afternoon and overtaking the lead boundary by late afternoon or evening. Carrying the inherited mention of fog early this morning across the area roughly north of a Rotan to Albany line, with freezing fog in the northern parts of Haskell and Throckmorton Counties where temperatures are at or just below freezing. With the marginally freezing temperatures and visibility with the fog to stay above one mile, not expecting any road ice problems this morning aross that area. Low cloud cover will be persistent through the day today across Haskell and Throckmorton counties. Temperature forecast today is tricky across the Big Country (area along/north of Interstate 20) with the initial frontal boundary. Made reductions across that area, where highs should be reached early this afternoon before temperatures level off and then slowly drop. Highs across that area are expected to range from the upper 30s/near 40 in Haskell and Throckmorton Counties, to the mid to upper 50s along Interstate 20 and 60s just south of I-20. Farther to the south, temperatures will be warm again today, with afternoon highs in the 70s to near 80 with mostly sunny skies. This evening and tonight, the reinforced cold front will push south through our central and southern counties, reaching the Interstate 10 corridor by 2 AM. Model boundary layer moisture fields indicate extensive low cloud cover developing south across West Central Texas behind the cold front, with areas of drizzle developing. With strong cold air advection, temperatures will drop to below freezing tonight across our northern and central counties, to the mid/upper 30s along and south of Interstate 10. With a weak overrunning pattern setting up and given the extent of boundary layer moistening, carrying areas of drizzle and freezing drizzle tonight until mid-morning Monday, with freezing drizzle mentioned where temperatures drop below freezing. 19 LONG TERM... (Monday night through Sunday) ..Winter precipitation possible Monday night and Tuesday... A cold surface ridge will be entrenched across the area Monday into Tuesday with temperatures remaining well below normal. An upper level trough will approach the area on Monday and move across the area on Tuesday. Still looks like the best chance for precipitation will be on Tuesday when lift from the upper trough will be greatest. Temperatures will be cold Monday and Tuesday with highs both days in the 30s across much of the area with the exception of far southern counties where some low to mid 40s are expected. Temperatures will fall into the 20s areawide Monday night. Made only minor changes to the forecast Monday night and Tuesday, mainly for precipitation type. Model forecast soundings continue to show a substantial warm layer aloft for much of this time period and a lack of moisture within the dendritic growth zone. This type of profile will favor a combination of freezing rain and sleet Monday night into Tuesday morning, with rain across southern sections and a winter mix across northern sections by Tuesday afternoon. Profiles due appear a bit more favorable for some snow to mix in mainly north of I-20 on Tuesday. At the present time, precipitation amounts are expected to be very light for this event, generally one tenth inch or less water equivalent with only minor snow and ice accumulations. Dry and warmer weather returns to the area Wednesday through Saturday with above normal temperatures through the period. The only mentionable feature will be a weak front on Saturday, with only slightly cooler temperatures into Sunday. && .PRELIMINARY POINT TEMPS/POPS... Abilene 57 25 36 23 37 / 5 10 10 20 30 San Angelo 79 30 41 26 39 / 0 10 10 20 30 Junction 79 37 45 29 42 / 0 10 20 20 30 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/99/99
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
459 AM CST SUN FEB 9 2014 .SHORT TERM... (Today and Tonight) A nearly stationary surface boundary extends from the eastern Texas Panhandle south to just northeast of Jayton, then east across Haskell and Throckmorton Counties. Temperatures are colder behind east/north of this boundary, where low cloudiness has filled in with areas of freezing fog. A strong cold front is moving south across Kansas. The NAM12 and RUC13 models appear to have the best handle on this boundary...and have it sagging south as a cold front to the Interstate 20 corridor by 11 AM to Noon, and then drifting a little farther south early this afternoon. Meanwhile, the aforementioned strong cold front will quickly move south today, entering the Big Country this afternoon and overtaking the lead boundary by late afternoon or evening. Carrying the inherited mention of fog early this morning across the area roughly north of a Rotan to Albany line, with freezing fog in the northern parts of Haskell and Throckmorton Counties where temperatures are at or just below freezing. With the marginally freezing temperatures and visibility with the fog to stay above one mile, not expecting any road ice problems this morning aross that area. Low cloud cover will be persistent through the day today across Haskell and Throckmorton counties. Temperature forecast today is tricky across the Big Country (area along/north of Interstate 20) with the initial frontal boundary. Made reductions across that area, where highs should be reached early this afternoon before temperatures level off and then slowly drop. Highs across that area are expected to range from the upper 30s/near 40 in Haskell and Throckmorton Counties, to the mid to upper 50s along Interstate 20 and 60s just south of I-20. Farther to the south, temperatures will be warm again today, with afternoon highs in the 70s to near 80 with mostly sunny skies. This evening and tonight, the reinforced cold front will push south through our central and southern counties, reaching the Interstate 10 corridor by 2 AM. Model boundary layer moisture fields indicate extensive low cloud cover developing south across West Central Texas behind the cold front, with areas of drizzle developing. With strong cold air advection, temperatures will drop to below freezing tonight across our northern and central counties, to the mid/upper 30s along and south of Interstate 10. With a weak overrunning pattern setting up and given the extent of boundary layer moistening, carrying areas of drizzle and freezing drizzle tonight until mid-morning Monday, with freezing drizzle mentioned where temperatures drop below freezing. 19 .LONG TERM... (Monday night through Sunday) ...Winter precipitation possible Monday night and Tuesday... A cold surface ridge will be entrenched across the area Monday into Tuesday with temperatures remaining well below normal. An upper level trough will approach the area on Monday and move across the area on Tuesday. Still looks like the best chance for precipitation will be on Tuesday when lift from the upper trough will be greatest. Temperatures will be cold Monday and Tuesday with highs both days in the 30s across much of the area with the exception of far southern counties where some low to mid 40s are expected. Temperatures will fall into the 20s areawide Monday night. Made only minor changes to the forecast Monday night and Tuesday, mainly for precipitation type. Model forecast soundings continue to show a substantial warm layer aloft for much of this time period and a lack of moisture within the dendritic growth zone. This type of profile will favor a combination of freezing rain and sleet Monday night into Tuesday morning, with rain across southern sections and a winter mix across northern sections by Tuesday afternoon. Profiles due appear a bit more favorable for some snow to mix in mainly north of I-20 on Tuesday. At the present time, precipitation amounts are expected to be very light for this event, generally one tenth inch or less water equivalent with only minor snow and ice accumulations. Dry and warmer weather returns to the area Wednesday through Saturday with above normal temperatures through the period. The only mentionable feature will be a weak front on Saturday, with only slightly cooler temperatures into Sunday. && .PRELIMINARY POINT TEMPS/POPS... Abilene 57 25 36 23 37 / 5 10 10 20 30 San Angelo 79 30 41 26 39 / 0 10 10 20 30 Junction 79 37 45 30 42 / 0 10 20 20 30 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 19/24
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
704 AM EST SUN FEB 9 2014 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE FROM THE WESTERN GREAT LAKES ACROSS THE OHIO VALLEY AND INTO PENNSYLVANIA TODAY...ITS ASSOCIATED SURFACE COLD FRONT CROSSING THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY. COLD HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST TUESDAY. NEXT WEEK...AN AREA OF LOW PRESSURE IS FORECAST TO DEVELOP OVER TEXAS...AND SLOWLY MOVE EAST ACROSS THE SOUTHERN STATES TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 645 AM EST SUNDAY... TN/KY RADAR SHOWING HIGHER REFLECTIVITY WITH PRECIP AND SNOW BEING REPORTED OVER PORTIONS OF SOUTHERN KY. HRRR APPEARS TO HAVE A FULL HANDLE ON THIS...BUT THEN IT DIMINISHES IT AS IT MOVES IT INTO WV BY LATE MORNING. 12Z RNK SOUNDING COMING IN SHOWING LOW LVL MOISTURE. OUR RADAR SHOWS VERY LIGHT RETURNS FADING ACROSS THE MTNS OF CRAIG COUNTY. COULD STILL SEE OVER TOWARD WV/ALLEGHANYS SOME PATCHY FZDZ OR DZ THIS MORNING. SNOW/RAIN SHOWERS WILL BE ARRIVING INTO THE MTNS OF WV EAST TOWARD HSP AROUND BY NOON...BUT TAPERED POPS OFF SOME THIS MORNING BASED ON LATEST RADAR/MODEL TRENDS. PREVIOUS VALID DISCUSSION... COLD FRONT MOVING ACROSS THE WRN OHIO VALLEY THIS MORNING WILL BRING A BETTER CONVERGENT PATTERN WITH SOME UPPER SUPPORT TO THE MOUNTAINS BY MIDDAY. KEPT POPS HIGHER IN THE NW...THEN SHIFT THEM TO LESS THAN 15 PERCENT IN THE NW NC PIEDMONT. THIS SEEMS TO BE A CASE WHERE THE BEST LIFT SHIFTS ACROSS THE MTNS OF WV/ALLEGHANYS AND THE ENE INTO NRN VA...AS UPPER PATTERN SHOWS SPLIT BETWEEN TWO SHORTWAVES. SOUNDINGS FORECASTING MAINLY SNOW OR RAIN SHOWERS THROUGH THIS EVENING...BUT SOME SUPPORT TO INCLUDE ICE PELLETS EXISTS...ALTHOUGH SHORT LIVED OVER THE HIGHER ELEVATIONS OF SW VA/NW NC THIS AFTERNOON. OVERALL...SNOW AMOUNTS ARE STAYING UNDER 2 INCHES...WITH HIGHER ELEVATIONS OF WRN GREENBRIER TOPPING OUT WITH 2...WHILE REST OF THE WRN SLOPES WILL GET AN INCH OR SO...WITH LESS THAN AN INCH INTO THE MOUNTAINS OF THE NEW RIVER VALLEY...SOUTHWEST TOWARD THE NC MTNS. MODELS HINT AT EVEN AREAS NORTH OF ROANOKE AND LYNCHBURG ALONG THE RIDGES COULD SEE A DUSTING TO JUST UNDER AN INCH. AGAIN...THE CMC/NAM FAVOR CLEARING BEHIND THIS WAVE LATE THIS MORNING INTO THE AFTERNOON OVER THE NC FOOTHILLS PIEDMONT. LEANED TOWARD A CLOUDIER SOLUTION...AS THESE MODELS DID NOT PICK INITIALIZE WELL WITH THE ONGOING SAT TRENDS...SO LEANED MY SKY COVER FORECAST TOWARD A LOCAL WRF/MOSGUIDE SOLUTION. STILL COULD SEE ENOUGH SUN IN THE SOUTHEAST TO WARM TEMPS INTO THE LOWER 50S AHEAD OF THE FRONT. MEANWHILE CLOUDS AND COLD ADVECTION IN THE MOUNTAINS THIS AFTERNOON WILL HINDER TEMPS. TEMPS FOR TODAY ARE TRICKY GIVEN CLOUD COVER/PRECIP AND TIMING OF COLD AIR ADVECTION. WENT WITH MID TO UPPER 30S ALLEGHANY HIGHLANDS...GREENBRIER COUNTY WV TO MID 40S NEW RIVER VALLEY/NC MTNS...AND UPPER 40S TO LOWER 50S ROA-LYH...MID 50S SOUTHSIDE VA...NW NC FOOTHILLS/PIEDMONT. DECENT ENOUGH PRESSURE GRADIENT BEHIND THE FRONT THIS AFTERNOON/EVENING TO SEE GUSTS TO 30 MPH OVER THE MOUNTAINS. THROUGH TONIGHT...THE MODELS ARE FAVORING WRN SLOPES WITH SNOW SHOWERS...WHERE AN ADDITIONAL INCH IS POSSIBLE WRN GREENBRIER AND LESS ELSEWHERE THE MOUNTAINS. FRONT EXPECTED TO REACH A NORFOLK VA TO ATL GA LINE OVERNIGHT BEFORE STALLING DUE TO PARALLEL UPPER FLOW. SKIES STAY CLOUDY IN THE WEST WITH MOSTLY CLOUDY WITH SOME BREAKS OUT EAST. LOWS RANGE FROM THE LOWER 20S ACROSS SE WV...TO LOWER 30S PIEDMONT. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... AS OF 344 AM EST SATURDAY... MODELS ARE IN FAIRLY GOOD AGREEMENT WITH PUSHING A SURFACE FRONT ACROSS THE AREA AND INTO NORTH CAROLINA MONDAY. HOW FAR SOUTH DOES THIS FRONT GO MONDAY NIGHT INTO TUESDAY IS QUESTIONABLE...CONSIDERING THE EASTERN HALF OF THE US WILL BE UNDER ZONAL FLOW. ALL 00Z MODELS ARE PUSHING THE FRONT DOWN INTO THE GULF. JUST INLAND AND BEHIND THE FRONT...A MID LEVEL DISTURBANCE IS EXPECTED TO TRACK ALONG THE GULF STATES INTO SOUTHEASTERN US MONDAY NIGHT INTO TUESDAY. TUESDAY NIGHT INTO WEDNESDAY...A STRONGER WAVE WILL FOLLOW IN THE FOOT STEPS OF THE FIRST DISTURBANCE. THE CURRENT FORECAST TRACK OF BOTH SYSTEMS ARE FAR ENOUGH TO THE SOUTH TO KEEP MOST OF THE FORECAST AREA DRY. IF MOISTURE DOES ADVANCE NORTH THROUGH THE PERIOD...THE HIGHEST PRECIPITATION CHANCES (30 PERCENT) WOULD BE ALONG AND SOUTH OF THE NC/VA BORDER. THERE IS ALSO ANOTHER PLAYER TO THIS GAME. A COLD HIGH PRESSURE SYSTEM IS EXPECTED TO TRACK FROM THE UPPER MID WEST MONDAY NIGHT AND OVER THE OHIO VALLEY TUESDAY. THIS RIDGE WILL THEN WEDGE DOWN THE EAST COAST TUESDAY NIGHT INTO WEDNESDAY. THIS RIDGE WILL BRING COLD AIR AND EASTERLY FLOW TO HAVE MOST OF THE PRECIPITATION FALLING AS SNOW. THE WAY IT LOOKS RIGHT NOW...OUR WEATHER WILL BE DOMINATED BY THE COLD DRY HIGH. THEREFORE I KEPT ANY POPS IN THE PERIOD LOW AND TO THE SOUTH. IT IS THE SECOND STRONGER WAVE THAT HAS ME MORE CONCERN. EVEN THOUGH THIS WAVE TRACKS ALONG THE GULF STATES...OVERRUNNING MOISTURE AND WARM NOSE MAY BE SIGNIFICANT ENOUGH TO PRODUCE P-TYPE ISSUES FOR THE FORECAST AREA WEDNESDAY AND WEDNESDAY NIGHT AS PER 00Z ECM. SINCE MODELS HAVE A DIFFERENT OPINION OF WHERE THE SECOND WAVE TRACKS AND BEHAVES...WILL WAIT AND TACKLE THIS PROBLEM AT A LATER TIME. TEMPERATURES MONDAY WILL BE A LITTLE TRICKY WITH THE PASSING OF A SLOW MOVING COLD FRONT. GUIDANCE TEMPERATURES...ESPECIALLY IN THE EAST VARY GREATLY. GFSMOS FOR DANVILLE HAS A HIGH OF 46F WHILE THE NAMMOS IS COLDER AT 38F. SINCE THE FRONT IS A SLOW MOVER AND A WEST WIND DEVELOPS QUICKLY...LEANED TEMPERATURES TOWARDS THE WARMER GFSMOS...ESPECIALLY IN THE EAST. ON TUESDAY...UNDERCUT GUIDANCE WITH INCREASING EASTERLY FLOW. I WENT EVEN COLDER THAN GUIDANCE ON WEDNESDAY AS PRECIPITATION CHANCES ARE ON THE INCREASE WITH A COLD WEDGE IN PLACE. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... AS OF 325 PM EST FRIDAY... BECAUSE OF THE GREAT VARIABILITY IN THE MEDIUM RANGE SOLUTION...WILL LEAN TOWARDS HPCGUIDE SHAPED AWAY FROM THE DETERMINISTIC GFS AND ECMWF...AND MORE TOWARD THE SURFACE LOW AND TRACKS OF THE GEFS AND EC ENSEMBLE MEANS. GUIDANCE REMAINS IN DISAGREEMENT WITH THE ECMWF/CMC MORE CONSISTENT WITH PREVIOUS RUNS AND FURTHER NORTH WITH THE MOISTURE...COMPARED TO GFS BEING SLOWER AND WARMER WITH MORE SOUTHERN TRACK. DECIDED TO KEEP THE HIGHEST POPS FROM WEDNESDAY NIGHT INTO THURSDAY. BECAUSE OF THE UNCERTAINTY WITH THIS WINTER STORM...HARD TO WORK OUT THE EXACT DETAILS OF TIMING...TRACK AND SNOW ACCUMULATIONS AT THIS POINT. THURSDAY AFTERNOON INTO THURSDAY NIGHT...COASTAL LOW PRESSURE CENTER AND ITS ASSOCIATED COLD FRONT WILL CONTINUE TO MOVE OUT INTO THE ATLANTIC OCEAN. MEANWHILE...LOW PRESSURE WITH A TRAILING COLD FRONT WILL DROP SOUTHEAST ACROSS THE GREAT LAKES. ON THE FRIDAY...THE COLD FRONT WILL CONTINUE TO MOVE EAST AS HIGH PRESSURE BUILDS OVER THE MIDWEST. IN THIS PROGRESSIVE FLOW...A COLD FRONT WILL TRAVEL EAST ACROSS OUR AREA ON SATURDAY. PLACED THE HIGHEST POPS IN THE WESTERN MOUNTAINS. TEMPERATURES WILL START COLD AND SLOWLY MODERATE TOWARDS THE END OF THE WEEK. THEN...A COOLING TEND IS EXPECTED INTO EARLY NEXT WEEK. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AS OF 645 AM EST SUNDAY... KEEPING LOW CIGS AT BLF THIS MORNING AS UPSTREAM METARS INDICATE AROUND 1-2KFT CIGS...AND BLF BEING HIGHER UP SHOULD SEE THE LOWER SIDE OF THIS. MVFR CIGS AT BCB/LWB THIS MORNING AS WELL. PATCHY FZDZ/DZ POSSIBLE AT BLF/LWB UNTIL 15Z...BUT SFC OBS INDICATE NOTHING...SO LEFT IT OUT OF THE TAFS. SHOULD SEE SOME MVFR CIGS APPROACH ROANOKE THIS MORNING AND WILL SEE A FEW HOURS BEFORE COMING BACK UP TO VFR THIS AFTERNOON. FRONTAL SYSTEM MOVES SOUTHEAST THROUGH THE AREA BY THIS EVENING. MODELS ARE MAINLY KEEPING THREAT OF PRECIP IN LWB/BLF...WITH LIGHT RAIN/SNOW. KEPT CIGS SUB VFR IN THE MTNS TODAY WHILE FROM BCB EAST TOOK TO VFR. WINDS BEHIND THE FRONT WILL PICK UP AND SHIFT FROM VRB TO SOUTHEAST THIS MORNING TO WEST BETWEEN 17Z BLF/LWB TO 01Z AT DAN. GUSTS TO 20 KNOTS WILL BE POSSIBLE ESPECIALLY ROA/BCB. TONIGHT...THE UPSLOPE WEST FLOW WILL HAVE BLF/LWB AND BCB MVFR AND LOWER. EAST OF THE MTNS...SHOULD BE VFR WITH SOME MID/HIGH CLOUDS SPREADING ACROSS. FRONT SLOWS DOWN/STALLS SOUTH OF US MONDAY WITH ANOTHER LOW PRESSURE AREA MOVING ALONG IT. AT THIS TIME...PRECIP CHANCES SHOULD BE LOW MONDAY...AND CIGS WILL BE MVFR WEST TO VFR EAST. MODELS STILL ADVERTISING POOR FLYING CONDITIONS FROM OUR GENERAL AREA SOUTHEAST TO THE COAST TUE-THU WITH A STRONGER LOW FORMING ALONG THE FRONT. AT THIS TIME SNOW WOULD BE THE MAIN PRECIP TYPE OVER OUR AREA WITH POSSIBLY RAIN MIXING IN AT DAN. DUE TO THE UNCERTAINTY TO THE LOW TRACK...STAY TUNED...BUT TRAVEL BY AIR OVERALL DOES NO LOOK FAVORABLE MIDWEEK. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PM NEAR TERM...WP SHORT TERM...RCS LONG TERM...KK AVIATION...WP
AREA FORECAST DISCUSSION
NWS GOODLAND KS
119 PM MST SUN FEB 9 2014 .UPDATE... ISSUED AT 549 AM MST SUN FEB 9 2014 JUST COMPLETED AN UPDATE. LOOKS LIKE THE MAIN BAND OF SNOW AT THIS TIME IS ALONG AND NORTH OF THE KANSAS AND NEBRASKA BORDER. FURTHER SOUTH LITTLE IF ANY SNOW FALLING. GOING BY SURFACE OBSERVATIONS TO MY SOUTH AND THE 12Z DDC SOUNDING...SATURATED LOW LEVEL AIR MASS NEAR THE DENDRITIC ZONE WITH LITTLE TO NO MOISTURE ABOVE THIS. THIS MATCHES WELL WITH WHAT MODEL SOUNDINGS HAD INDICATED. OUTSIDE OF THE MAIN SNOW BAND EXPECT WHAT IS CURRENTLY GOING ON TO CONTINUE WHICH AREAS OF FREEZING FOG AND SOME FREEZING DRIZZLE. AFTER THIS BAND OF SNOW LEAVES...MESOSCALE OUTPUT INDICATING LITTLE IF ANY MORE SNOW WILL FALL FOR MUCH OF THE REST OF THE DAY. CONSIDERING THE AIR MASS IN PLACE AND NOT TO CHANGE THAT...EXPECT THE FREEZING FOG AND DRIZZLE TO CONTINUE THROUGH THE ENTIRE DAY. ADJUSTED MAXES BASED ON CURRENT READINGS AND TRENDS. ALSO ADJUSTED THE WINDS PER TRENDS AND LATEST RUC WHICH LOOKS LIKE IT IS CATCHING THIS THE BEST. && .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 339 AM MST SUN FEB 9 2014 FORECAST CONCERNS WILL BE PRECIPITATION CHANCES THROUGH THE SHORT TERM...ESPECIALLY THROUGH MONDAY...HOW COLD TO MAKE IT TODAY AND MONDAY...AND HOW MUCH WARMING OCCURS ON TUESDAY. SATELLITE SHOWING AN AMPLIFIED/BLOCKY/RETROGRESSIVE PATTERN OVER THE WESTERN HALF OF THE PACIFIC. BECAUSE THE UPPER FEATURES HAVE CONTINUED TO MOVE WEST THAT LEAVES A FAST AND NEARLY ZONAL FROM FROM THE EASTERN PACIFIC INTO THE ATLANTIC. THERE WERE SOME MODERATION IN THE LOW LEVEL AIR MASS AS SOME MELTING OF THE SNOW DID OCCUR. HOWEVER ANOTHER VERY COLD AIR MASS IN PUSHING THE REGION AT THIS TIME. AT JET LEVEL...MODELS ARE NOT GETTING THE POSITION OF THE MAIN JETS...THE ONE OVER OUR AREA RIGHT NOW AND THE ONE COMING FROM THE PACIFIC NORTHWEST. OVERALL AT THIS TIME THE GFS AND UKMET WERE DOING THE BEST. ALTHOUGH THE ECMWF WAS DOING BETTER IN THE PACIFIC NORTHWEST. AT MID LEVELS...MODELS WERE HAVING THE SAME PROBLEMS IN POSITION OF FEATURES AS AT THE JET LEVEL. MODELS TENDED TO BE TOO FAR SOUTH AND EAST WITH FEATURES. OVERALL THE GFS AND UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF AND CANADIAN. THE ECMWF IS DOING WAY BETTER THAN EVERYTHING ELSE ON THE SURFACE PATTERN... ESPECIALLY THE LOCATION OF THIS CURRENT COLD SURGE AND THE SURFACE TROUGHING TO OUR WEST. THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE CANADIAN AND NAM ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...STRONG LEFT FRONT QUADRANT OF PACIFIC NORTHWEST JET STARTS AFFECTING THE NORTHEAST HALF TO TWO THIRDS AT THE BEGINNING OF THE DAY. THIS JET SEGMENT RAPIDLY MOVES THROUGH BY 18Z AND IS TO THE NORTH OF THE AREA BY THEN. THIS IS AT THE SAME TIME A SHORTWAVE MOVES ACROSS. THE BRUNT OF LIFT LOOKS TO BE OUR NORTH. MODEL DEPICTION LOOKS SIMILAR TO WHAT THE PREVIOUS FORECAST HAD AND ONLY MADE MINOR ADJUSTMENTS. GREATEST CHANCE FOR PRECIPITATION WILL BE IN THE NORTH AND THIS MORNING. LITTLE TO NO LIFT IS AROUND FOR MOST OF THE REST OF THE DAY. PRECIPITATION TYPE IS A LITTLE MORE OF A PROBLEM TODAY. MODELS NOT AS SATURATED IN THE COLUMN AS WAS SHOWN TODAY. THE ONLY PLACE WHERE IT LOOKS LIKE ALL SNOW IS IN THE NORTHERN PORTION OF MY AREA ESPECIALLY THIS MORNING. OVER THE REMAINDER OF THE AREA...THERE LOOKS LIKE THERE COULD BE ICE IN THE COLUMN...ESPECIALLY DOWN LOW...BUT MODELS ARE INDICATING A WARM LAYER NOT TOO FAR ABOVE THE SURFACE. ALSO THE THIS AFTERNOON THERE IS LITTLE TO NO LIFT OR MID LEVEL MOISTURE AROUND. PRECIPITATION FOR MOST OF THE AFTERNOON LOOKS LIGHT AND COULD BE A MIXTURE OF FREEZING DRIZZLE OR SNOW AND ADJUST ACCORDINGLY. EXPECT LITTLE TO NO TEMPERATURE RISE. PROBLEM IS MODELS LOOK TO BE STARTING OUT TOO COLD. HOWEVER DID TEND GO TOWARD THE COOLER GUIDANCE. AT THE BEGINNING OF THE NIGHT THE MODELS HAVE COME INTO AGREEMENT IN DEVELOPING A COUPLED JET STRUCTURE OVER THE AREA. THIS INITIAL COUPLET MOVES SOUTH THROUGH THE NIGHT AND APPEARS TO BE JUST SOUTH OF THE AREA BY THE END OF THE NIGHT. A MODERATELY STRONG PV ANOMALY APPROACHES DURING THE EVENING. MESOSCALE LIFT DOES NOT APPEAR VERY ORGANIZED. ICE LOOKS TO GET INTO THE COLUMN WITH THETA-E LAPSE RATES SO SNOW APPEARS TO BE THE PHASE. FAVORED AREA FOR THE BEST CHANCE OF PRECIPITATION WILL BE SOUTH/SOUTHWEST HALF. MAIN AREA OF PRECIPITATION LOOKS TO BE OVER THE FAR SOUTH LATE IN THE NIGHT. OVERNIGHT TEMPERATURES SHOULD NOT DROP MUCH DUE TO THICK CLOUD COVER AND WINDS. MONDAY/MONDAY NIGHT...AS STATED ABOVE FIRST COUPLET APPEARS TO BE SOUTH OF THE AREA BY 12Z. HOWEVER...A FEW OF THE MODELS DEVELOP A SECONDARY NORTHERN JET STREAK JUST TO OUR NORTH AT THE BEGINNING OF THE DAY. ANOTHER RIGHT REAR QUADRANT APPEARS TO BE JUST NORTHWEST OF OUR AREA AT 12Z WITH A POSSIBLE WEAK COUPLET TO OUR WEST. THIS NORTHERN JET STREAK/RIGHT REAR QUADRANT MOVES ACROSS THE AREA DURING THE DAY. SO INCREASED POPS TO A LOW CHANCE IN THE MORNING WITH A SLIGHT CHANCE IN THE AFTERNOON AS THE LIFT IS STARTING MOVE OUT OF THE AREA. SHOULD HAVE THICK CLOUD COVER AND UPSLOPE WINDS SO LITTLE CHANCE FOR TEMPERATURES TO RISE MUCH. ONLY MADE MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST. THERE LOOKS TO BE LINGERING LIFT AND MOISTURE EARLY SO HAVE A MENTION OF FLURRIES IN THE EVENING. WINDS SHIFT AROUND TO THE WEST AND WARM AIR ADVECTION BEGINS. BECAUSE OF VARIABLE CLOUD COVER AND A SNOWFIELD...THE LOW TEMPERATURES WILL BE VERY HARD TO PIN DOWN. SUFFICE TO SAY THE LAST TIME THIS HAPPENED A FEW DAYS...THE MODELS TENDED TO BE TOO COLD. TUESDAY/TUESDAY NIGHT...A STRONG NORTH TO SOUTH JET APPROACHES THE AREA DURING THE EVENING WITH LEFT FRONT QUADRANT AFFECTING THE WESTERN THIRD TO HALF BY 06Z. MODELS DIFFER ON HOW FAST THEY MOVE THIS FEATURE THE REST OF THE NIGHT WITH THE LEFT FRONT QUADRANT AFFECT SOME PORTION OF THE AREA DURING THE LATER HALF OF THE NIGHT... MAINLY EAST. HOWEVER...MODEL SOUNDINGS ARE SHOWING A SUBSTANTIAL DRY LAYER. SO WILL ONLY EXPECT A THICKENING MID AND UPPER LEVEL CLOUD DECK WITH THIS ENTIRE PERIOD REMAINING DRY. AIR MASS WARMS SIGNIFICANTLY WITH DOWNSLOPE WINDS SPREADING OVER MOST OF THE AREA. AT FIRST GLANCE THE NWP APPEARS TO WARM. THE 2 METER TEMPERATURES ARE SLIGHTLY COOLER AND THEY DID DO BETTER YESTERDAY IN A SIMILAR SETUP TO THIS ONCE. ONLY MADE SLIGHT ADJUSTMENTS TO MAXES WITH THE COOLEST IN THE EAST AND WARMEST ALONG AND WEST OF THE COLORADO BORDER. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 119 PM MST SUN FEB 9 2014 THE MAIN STORY FOR THE EXTENDED FORECAST PERIOD CONCERNS A SHIFT IN THE WEATHER PATTERN FROM AN ACTIVE...COLD AND SNOWY PATTERN TO A MUCH WARMER...DRY PATTERN AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WESTERN UNITED STATES. THE GFS AND EUROPEAN MODELS INDICATE THAT THE WEAK RIDGE MAY LAST INTO AT LEAST THE MIDDLE OF NEXT WEEK AND POSSIBLY BEYOND. THIS WOULD MEAN WARMER AND DRIER THAN NORMAL CONDITIONS AND INITIAL BLEND OF FORECAST GUIDANCE GIVES JUST THAT. NO PRECIPITATION IS ANTICIPATED FROM WEDNESDAY THROUGH THE REST OF THE EXTENDED FORECAST. FOR MONDAY NIGHT INTO WEDNESDAY...THE LAST TWO OF A SERIES OF WAVES WILL MOVE THROUGH AND BRING A COUPLE LAST CHANCES OF PRECIPITATION. WITH COLD TEMPERATURES STILL IN PLACE...ALL PRECIPITATION SHOULD BE SNOW. THE FIRST WAVE MOVES ACROSS THE SOUTHWESTERN CORNER OF THE FORECAST AREA MONDAY NIGHT. THE BEST CHANCES FOR PRECIPITATION WILL BE IN THE EVENING HOURS. THE SECOND WAVE MOVES ACROSS NORTHWEST PORTIONS OF THE FORECAST AREA TUESDAY NIGHT. FOR BOTH DISTURBANCES...PRECIPITATION AMOUNTS SHOULD BE FAIRLY LIGHT AS THESE TWO WAVES DO NOT POSSESS THE STRONGER CHARACTERISTICS NEEDED TO EXPECT HIGHER PRECIPITATION AMOUNTS. THE WARMING TREND ALLUDED TO EARLIER BEGINS TUESDAY. WITH SOME BREAKS IN THE CLOUDS BETWEEN THE TWO DISTURBANCES...WARMING 850 MB TEMPERATURES AND SOUTHWEST WINDS...HIGHS FOR TUESDAY SHOULD APPROACH NORMAL LEVELS. THE SNOW STILL ON THE GROUND COMPLICATES THE TEMPERATURE FORECAST BUT THERE WERE ENOUGH SIGNS TO MAINTAIN A TEMP FORECAST IN THE 30S TO LOW 40S. MODELS HAVE TRENDED COOLER FOR WEDNESDAY...LIKELY DUE TO ANTICIPATED SNOW ON THE GROUND. ENDED UP LOWERING TEMPS SOME FROM THE PREVIOUS FORECAST RUNS BUT THE WARMING TREND SHOULD CONTINUE. HIGHS SHOULD REACH INTO THE LOW TO MID 40S AS A FAIR AMOUNT OF SNOW SHOULD MELT ON TUESDAY AND WEDNESDAY. LOCAL CHANGES IN HIGH TEMPERATURES WILL LIKELY BE NEEDED...ESPECIALLY IN LOCATIONS WHERE 8 TO 12 INCHES OF SNOW REMAINS ON THE GROUND AT THE PRESENT TIME. WITH THE RIDGE OF HIGH PRESSURE BUILDING IN...A FAIRLY PERSISTENT FORECAST IS ADVERTISED FROM THURSDAY THROUGH THE WEEKEND. ABOVE NORMAL TEMPERATURES SHOULD BE EXPECTED WITH HIGHS IN THE 50S AND LOWS IN THE UPPER 20S TO 30S. THE EUROPEAN MODEL HAS CONTINUED ITS TREND OF WARMING OVER THIS TIME FRAME. THE LATEST MODEL RUN IS NOW WARMER THAN THE GFS...A BIG CHANGE FROM THE 12Z EUROPEAN MODEL RUN YESTERDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1040 AM MST SUN FEB 9 2014 LIGHT SNOW WILL TAPER OFF EARLY THIS AFTERNOON WITH VIS AND CIGS IMPROVING SOME AT KGLD AND KMCK. THE NEXT DISTURBANCE WILL MOVE EAST OF THE ROCKIES THIS EVENING WITH CONDITIONS DROPPING DOWN TO LIFR TOWARD MORNING WITH FOG REDEVELOPMENT AFTER THE SNOW ENDS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...BULLER LONG TERM...RRH AVIATION...FS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
218 PM CST Sun Feb 9 2014 ...UPDATE TO LONG TERM... .SHORT TERM...(This evening through Monday) ISSUED AT 146 PM CST SUN FEB 9 2014 As the next upper tropospheric jet streak continues to approach tonight, there will be an increase in the response in the 800-600mb layer (particularly noted at 700mb) as an increase in deformation and convergence along the slowly southward moving mid level baroclinic zone. The latest runs of the HRRR are starting to line up nicely with other mesoscale models and even coarser global models with a west-northwest to east-southeast axis of light to moderate snow. The zone of 700mb frontogenesis will only be strongest over any one location for about 3 or 4 hours before quickly shifting off to the east. The fast duration of the event alone will limit potential accumulations, however during the height of the snowfall, rates could be on the order of one-half to three-quarters inch per hour. Placement of the heaviest snow band(s) is also still somewhat in question, but feel pretty confident it (they) will ultimately lie somewhere along/north of Highway 50 and south of Highway 4. The winter weather advisory that was issued midday encompasses this region of the forecast area for a general 1 to 3 inch accumulation. Given the expected banded nature of the event and forward motion of the frontogenesis somewhat parallel to band orientation, some isolated amounts in excess of 3 inches will be possible. Global and mesoscale models both show the meso-alpha scale frontogenesis weakening toward daybreak as it shifts toward south-central Kansas, so will be going with slightly lower amounts across the Stafford-Pratt-Barber County zone. We went ahead and removed the snow out of the forecast for the bulk of the day Monday except for the very end of the day across far southwest Kansas. The rest of the forecast was left unchanged as it appeared to be in pretty good shape (regarding temperatures, wind, etc.) .LONG TERM...(Monday night through Sunday) ISSUED AT 215 PM CST SUN FEB 9 2014 Medium range models indicate an upper level shortwave trough moving southeastward across the Western High Plains Monday night bringing precip chances to the region very early in the period. As the shortwave moves through, surface high pressure across the Upper Midwest will provide a southeasterly upslope flow near the surface while surface low pressure develops across New Mexico. This will set up increased low level convergence across the panhandles of Texas and Oklahoma into portions of southwest Kansas. Although the flow aloft will be less than favorable, enough low/mid level forcing will be present, including the presence of some H7 frontogenetic banding, to support light snow development across the panhandles with snow possibly reaching across the border into southwest Kansas. Fairly light QPF signals and PW values down around a quarter inch suggest minimal snow accumulations generally less than one inch through Tuesday morning. Drier conditions are then expected through the end of the week as weak upper level ridging develops across the Intermountain West. Temperatures will warm up Tuesday as surface high pressure departs eastern Kansas to the east returning a southerly low level flow to western Kansas. This will draw slightly warmer air northward with H85 temperatures ranging from around 5C below across central Kansas to near 0C in far southwest Kansas. Along with the help of expected decreased cloud cover, look for highs well up into the 30s(F) Tuesday afternoon with near 40F possible in extreme southwest Kansas. The warming trend continues into Wednesday with widespread 40s(F) expected for highs with near 50F possible in far southwest Kansas. Highs are likely to reach the 50s(F) to near 60F Thursday afternoon. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 1049 AM CST SUN FEB 9 2014 Latest indications are that ceilings will remain in the IFR category with average ceiling in the 600 to 1000 foot range at DDC and GCK. HYS will likely stay in MVFR for the remainder of the day until light snow begins to affect the terminal this evening. Light to occasionally moderate snow will move in mid-evening and persist for a 6-9 hour period across portions of southwest Kansas, including GCK and DDC terminals. During the heaviest period of snow, flight category of LIFR or perhaps briefly VLIFR can be expected overnight. Following the snow early Monday morning, ceiling will remain a problem with flight category likely staying in IFR, especially GCK and DDC. && .PRELIMINARY POINT TEMPS/POPS... DDC 8 16 4 32 / 80 20 20 0 GCK 8 18 6 34 / 80 10 20 0 EHA 12 24 12 40 / 30 20 30 10 LBL 12 21 8 36 / 40 20 20 10 HYS 5 13 0 30 / 60 20 10 0 P28 9 17 4 30 / 80 60 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY from 8 PM CST /7 PM MST/ this evening to 9 AM CST /8 AM MST/ Monday FOR KSZ030-031-043>046-061>066- 076>081-088>090. && $$ SHORT TERM...Umscheid LONG TERM...JJohnson AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
148 PM CST Sun Feb 9 2014 ...Updated short term section... .SHORT TERM...(This evening through Monday) ISSUED AT 146 PM CST SUN FEB 9 2014 As the next upper tropospheric jet streak continues to approach tonight, there will be an increase in the response in the 800-600mb layer (particularly noted at 700mb) as an increase in deformation and convergence along the slowly southward moving mid level baroclinic zone. The latest runs of the HRRR are starting to line up nicely with other mesoscale models and even coarser global models with a west-northwest to east-southeast axis of light to moderate snow. The zone of 700mb frontogenesis will only be strongest over any one location for about 3 or 4 hours before quickly shifting off to the east. The fast duration of the event alone will limit potential accumulations, however during the height of the snowfall, rates could be on the order of one-half to three-quarters inch per hour. Placement of the heaviest snow band(s) is also still somewhat in question, but feel pretty confident it (they) will ultimately lie somewhere along/north of Highway 50 and south of Highway 4. The winter weather advisory that was issued midday encompasses this region of the forecast area for a general 1 to 3 inch accumulation. Given the expected banded nature of the event and forward motion of the frontogenesis somewhat parallel to band orientation, some isolated amounts in excess of 3 inches will be possible. Global and mesoscale models both show the meso-alpha scale frontogenesis weakening toward daybreak as it shifts toward south-central Kansas, so will be going with slightly lower amounts across the Stafford-Pratt-Barber County zone. We went ahead and removed the snow out of the forecast for the bulk of the day Monday except for the very end of the day across far southwest Kansas. The rest of the forecast was left unchanged as it appeared to be in pretty good shape (regarding temperatures, wind, etc.) .LONG TERM...(Monday through Saturday) ISSUED AT 355 AM CST SUN FEB 9 2014 A weak shortwave trough will move through the Central Rockies along the zonal flow late Sunday. This shortwave will then move through Kansas on Monday. Convergence and mid level moisture will increase as this feature approaches. Mostly cloudy skies are anticipated throughout the day Monday with light to moderate snow showers. Precipitation chances end from west to east Monday evening into Monday night. Snow totals remain around 1 to 2 inches across the area. However, a few areas across west central and south central Kansas could see over 2 inches by the time the system exits the area. Surrounding offices and DDC have decided to not go with a winter weather advisory at this time and have the day shift see what the next model run suggests. Cloudy skies should continue Monday night with some clearing possible across west central Kansas towards sunrise. Winds will generally be from a northeasterly direction Monday as high pressure builds into the Plains. With the cloud cover and shot of cold air advection across the area, temperatures Monday are not expected to increase much from the morning lows. Highs Monday are forecasted to range from the lower teens across central Kansas to lower 20s across far southwestern Kansas. Lows Tuesday morning are expected to range from the negative single digits across central Kansas to around 10 degrees across far southwestern Kansas. However, if more clearing occurs overnight, temperatures could end up lower than what the current forecast depicts. The dome of high pressure moves east of the area on Tuesday shifting winds to the southwest. A few low level clouds may continue in the morning across south central Kansas Tuesday morning. Otherwise expect partly cloudy skies and dry conditions. The Central High Plains will then be stuck in between an upper level ridge across the western US and an upper level long wave trough across the eastern United states throughout the remainder of the forecast period. A few weak shortwaves are progged to move north of the area, but do not look to bring any precipitation across southwest Kansas at this time. Only a few clouds are expected to be observed throughout this period with dry conditions. Winds will generally be from the west but shift slightly to the north or south as the aforementioned shortwaves move north of southwest Kansas. We will finally begin the slow warming up process Tuesday through Saturday, however the snowpack across much of the region will need to be knocked out quite a bit before we realize maximum potential based on typical downslope mix-down scenarios. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 1049 AM CST SUN FEB 9 2014 Latest indications are that ceilings will remain in the IFR category with average ceiling in the 600 to 1000 foot range at DDC and GCK. HYS will likely stay in MVFR for the remainder of the day until light snow begins to affect the terminal this evening. Light to occasionally moderate snow will move in mid-evening and persist for a 6-9 hour period across portions of southwest Kansas, including GCK and DDC terminals. During the heaviest period of snow, flight category of LIFR or perhaps briefly VLIFR can be expected overnight. Following the snow early Monday morning, ceiling will remain a problem with flight category likely staying in IFR, especially GCK and DDC. && .PRELIMINARY POINT TEMPS/POPS... DDC 8 16 4 32 / 80 20 20 0 GCK 8 18 6 34 / 80 10 20 0 EHA 12 24 12 40 / 30 20 30 10 LBL 12 21 8 36 / 40 20 20 10 HYS 5 13 0 30 / 60 20 10 0 P28 9 17 4 30 / 80 60 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY from 8 PM CST /7 PM MST/ this evening to 9 AM CST /8 AM MST/ Monday FOR KSZ030-031-043>046-061>066- 076>081-088>090. && $$ SHORT TERM...Umscheid LONG TERM...Hovorka_42 AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1053 AM MST SUN FEB 9 2014 .UPDATE... ISSUED AT 549 AM MST SUN FEB 9 2014 JUST COMPLETED AN UPDATE. LOOKS LIKE THE MAIN BAND OF SNOW AT THIS TIME IS ALONG AND NORTH OF THE KANSAS AND NEBRASKA BORDER. FURTHER SOUTH LITTLE IF ANY SNOW FALLING. GOING BY SURFACE OBSERVATIONS TO MY SOUTH AND THE 12Z DDC SOUNDING...SATURATED LOW LEVEL AIR MASS NEAR THE DENDRITIC ZONE WITH LITTLE TO NO MOISTURE ABOVE THIS. THIS MATCHES WELL WITH WHAT MODEL SOUNDINGS HAD INDICATED. OUTSIDE OF THE MAIN SNOW BAND EXPECT WHAT IS CURRENTLY GOING ON TO CONTINUE WHICH AREAS OF FREEZING FOG AND SOME FREEZING DRIZZLE. AFTER THIS BAND OF SNOW LEAVES...MESOSCALE OUTPUT INDICATING LITTLE IF ANY MORE SNOW WILL FALL FOR MUCH OF THE REST OF THE DAY. CONSIDERING THE AIR MASS IN PLACE AND NOT TO CHANGE THAT...EXPECT THE FREEZING FOG AND DRIZZLE TO CONTINUE THROUGH THE ENTIRE DAY. ADJUSTED MAXES BASED ON CURRENT READINGS AND TRENDS. ALSO ADJUSTED THE WINDS PER TRENDS AND LATEST RUC WHICH LOOKS LIKE IT IS CATCHING THIS THE BEST. && .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 339 AM MST SUN FEB 9 2014 FORECAST CONCERNS WILL BE PRECIPITATION CHANCES THROUGH THE SHORT TERM...ESPECIALLY THROUGH MONDAY...HOW COLD TO MAKE IT TODAY AND MONDAY...AND HOW MUCH WARMING OCCURS ON TUESDAY. SATELLITE SHOWING AN AMPLIFIED/BLOCKY/RETROGRESSIVE PATTERN OVER THE WESTERN HALF OF THE PACIFIC. BECAUSE THE UPPER FEATURES HAVE CONTINUED TO MOVE WEST THAT LEAVES A FAST AND NEARLY ZONAL FROM FROM THE EASTERN PACIFIC INTO THE ATLANTIC. THERE WERE SOME MODERATION IN THE LOW LEVEL AIR MASS AS SOME MELTING OF THE SNOW DID OCCUR. HOWEVER ANOTHER VERY COLD AIR MASS IN PUSHING THE REGION AT THIS TIME. AT JET LEVEL...MODELS ARE NOT GETTING THE POSITION OF THE MAIN JETS...THE ONE OVER OUR AREA RIGHT NOW AND THE ONE COMING FROM THE PACIFIC NORTHWEST. OVERALL AT THIS TIME THE GFS AND UKMET WERE DOING THE BEST. ALTHOUGH THE ECMWF WAS DOING BETTER IN THE PACIFIC NORTHWEST. AT MID LEVELS...MODELS WERE HAVING THE SAME PROBLEMS IN POSITION OF FEATURES AS AT THE JET LEVEL. MODELS TENDED TO BE TOO FAR SOUTH AND EAST WITH FEATURES. OVERALL THE GFS AND UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF AND CANADIAN. THE ECMWF IS DOING WAY BETTER THAN EVERYTHING ELSE ON THE SURFACE PATTERN... ESPECIALLY THE LOCATION OF THIS CURRENT COLD SURGE AND THE SURFACE TROUGHING TO OUR WEST. THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE CANADIAN AND NAM ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...STRONG LEFT FRONT QUADRANT OF PACIFIC NORTHWEST JET STARTS AFFECTING THE NORTHEAST HALF TO TWO THIRDS AT THE BEGINNING OF THE DAY. THIS JET SEGMENT RAPIDLY MOVES THROUGH BY 18Z AND IS TO THE NORTH OF THE AREA BY THEN. THIS IS AT THE SAME TIME A SHORTWAVE MOVES ACROSS. THE BRUNT OF LIFT LOOKS TO BE OUR NORTH. MODEL DEPICTION LOOKS SIMILAR TO WHAT THE PREVIOUS FORECAST HAD AND ONLY MADE MINOR ADJUSTMENTS. GREATEST CHANCE FOR PRECIPITATION WILL BE IN THE NORTH AND THIS MORNING. LITTLE TO NO LIFT IS AROUND FOR MOST OF THE REST OF THE DAY. PRECIPITATION TYPE IS A LITTLE MORE OF A PROBLEM TODAY. MODELS NOT AS SATURATED IN THE COLUMN AS WAS SHOWN TODAY. THE ONLY PLACE WHERE IT LOOKS LIKE ALL SNOW IS IN THE NORTHERN PORTION OF MY AREA ESPECIALLY THIS MORNING. OVER THE REMAINDER OF THE AREA...THERE LOOKS LIKE THERE COULD BE ICE IN THE COLUMN...ESPECIALLY DOWN LOW...BUT MODELS ARE INDICATING A WARM LAYER NOT TOO FAR ABOVE THE SURFACE. ALSO THE THIS AFTERNOON THERE IS LITTLE TO NO LIFT OR MID LEVEL MOISTURE AROUND. PRECIPITATION FOR MOST OF THE AFTERNOON LOOKS LIGHT AND COULD BE A MIXTURE OF FREEZING DRIZZLE OR SNOW AND ADJUST ACCORDINGLY. EXPECT LITTLE TO NO TEMPERATURE RISE. PROBLEM IS MODELS LOOK TO BE STARTING OUT TOO COLD. HOWEVER DID TEND GO TOWARD THE COOLER GUIDANCE. AT THE BEGINNING OF THE NIGHT THE MODELS HAVE COME INTO AGREEMENT IN DEVELOPING A COUPLED JET STRUCTURE OVER THE AREA. THIS INITIAL COUPLET MOVES SOUTH THROUGH THE NIGHT AND APPEARS TO BE JUST SOUTH OF THE AREA BY THE END OF THE NIGHT. A MODERATELY STRONG PV ANOMALY APPROACHES DURING THE EVENING. MESOSCALE LIFT DOES NOT APPEAR VERY ORGANIZED. ICE LOOKS TO GET INTO THE COLUMN WITH THETA-E LAPSE RATES SO SNOW APPEARS TO BE THE PHASE. FAVORED AREA FOR THE BEST CHANCE OF PRECIPITATION WILL BE SOUTH/SOUTHWEST HALF. MAIN AREA OF PRECIPITATION LOOKS TO BE OVER THE FAR SOUTH LATE IN THE NIGHT. OVERNIGHT TEMPERATURES SHOULD NOT DROP MUCH DUE TO THICK CLOUD COVER AND WINDS. MONDAY/MONDAY NIGHT...AS STATED ABOVE FIRST COUPLET APPEARS TO BE SOUTH OF THE AREA BY 12Z. HOWEVER...A FEW OF THE MODELS DEVELOP A SECONDARY NORTHERN JET STREAK JUST TO OUR NORTH AT THE BEGINNING OF THE DAY. ANOTHER RIGHT REAR QUADRANT APPEARS TO BE JUST NORTHWEST OF OUR AREA AT 12Z WITH A POSSIBLE WEAK COUPLET TO OUR WEST. THIS NORTHERN JET STREAK/RIGHT REAR QUADRANT MOVES ACROSS THE AREA DURING THE DAY. SO INCREASED POPS TO A LOW CHANCE IN THE MORNING WITH A SLIGHT CHANCE IN THE AFTERNOON AS THE LIFT IS STARTING MOVE OUT OF THE AREA. SHOULD HAVE THICK CLOUD COVER AND UPSLOPE WINDS SO LITTLE CHANCE FOR TEMPERATURES TO RISE MUCH. ONLY MADE MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST. THERE LOOKS TO BE LINGERING LIFT AND MOISTURE EARLY SO HAVE A MENTION OF FLURRIES IN THE EVENING. WINDS SHIFT AROUND TO THE WEST AND WARM AIR ADVECTION BEGINS. BECAUSE OF VARIABLE CLOUD COVER AND A SNOWFIELD...THE LOW TEMPERATURES WILL BE VERY HARD TO PIN DOWN. SUFFICE TO SAY THE LAST TIME THIS HAPPENED A FEW DAYS...THE MODELS TENDED TO BE TOO COLD. TUESDAY/TUESDAY NIGHT...A STRONG NORTH TO SOUTH JET APPROACHES THE AREA DURING THE EVENING WITH LEFT FRONT QUADRANT AFFECTING THE WESTERN THIRD TO HALF BY 06Z. MODELS DIFFER ON HOW FAST THEY MOVE THIS FEATURE THE REST OF THE NIGHT WITH THE LEFT FRONT QUADRANT AFFECT SOME PORTION OF THE AREA DURING THE LATER HALF OF THE NIGHT... MAINLY EAST. HOWEVER...MODEL SOUNDINGS ARE SHOWING A SUBSTANTIAL DRY LAYER. SO WILL ONLY EXPECT A THICKENING MID AND UPPER LEVEL CLOUD DECK WITH THIS ENTIRE PERIOD REMAINING DRY. AIR MASS WARMS SIGNIFICANTLY WITH DOWNSLOPE WINDS SPREADING OVER MOST OF THE AREA. AT FIRST GLANCE THE NWP APPEARS TO WARM. THE 2 METER TEMPERATURES ARE SLIGHTLY COOLER AND THEY DID DO BETTER YESTERDAY IN A SIMILAR SETUP TO THIS ONCE. ONLY MADE SLIGHT ADJUSTMENTS TO MAXES WITH THE COOLEST IN THE EAST AND WARMEST ALONG AND WEST OF THE COLORADO BORDER. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 339 AM MST SUN FEB 9 2014 H5 RIDGE BUILDS INTO THE WESTERN US WITH WESTERLY FLOW SHIFTING TO NW ACROSS NORTHERN PLAINS AND MEAN STORM TRACK REMAINING ALONG THE CANADIAN/US BORDER. THIS WILL RESULT IN WARMER TEMPS AND PREDOMINATELY DRY CONDITIONS. THE ECMWF IS THE ONLY MODEL ON PAST MODEL RUNS TO EVEN HINT AT LIGHT PRECIP CHANCES...HOWEVER EVEN IT HAS TRENDED FURTHER NORTH WITH TRACK OF SHORTWAVE TROUGHS EMBEDDED IN THE MEAN FLOW ALOFT. GFS/GEFS/GEM ALL SUPPORT DRY CONDITIONS AND MUCH WEAKER SHORTWAVES (AND LESS OF AN IMPACT IN THE HEIGHT FIELDS OVER OUR CWA AS A RESULT). THERE HAS ALSO BEEN A TREND BY THE LATEST ECMWF TO KEEP BACKDOOR COLD FRONTS FURTHER NORTH (IN LINE WITH OTHER GUIDANCE)...WHICH WOULD LIMIT ANY IMPACT OF THESE TROUGH PASSAGES... AND KEEP ABOVE NORMAL TEMPS IN PLACE. AT THIS POINT OTHER THAN NON MEASURABLE PRECIP HINTED AT BY ECMWF THU NIGHT-FRI (WHICH I HAVE VERY LOW CONFIDENCE IN BASED ON THE LARGE SCALE PATTERN) IT LOOKS LIKE WE ARE ABOUT TO ENTER A PROLONGED PERIOD OF MILD/DRY CONDITIONS. HIGH TEMPS SHOULD BE NEAR SEASONAL NORMS ON WED IN THE 40S...WITH HIGHS IN THE 50S LATE NEXT WEEK INTO NEXT WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1040 AM MST SUN FEB 9 2014 LIGHT SNOW WILL TAPER OFF EARLY THIS AFTERNOON WITH VIS AND CIGS IMPROVING SOME AT KGLD AND KMCK. THE NEXT DISTURBANCE WILL MOVE EAST OF THE ROCKIES THIS EVENING WITH CONDITIONS DROPPING DOWN TO LIFR TOWARD MORNING WITH FOG REDEVELOPMENT AFTER THE SNOW ENDS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...BULLER LONG TERM...DJR AVIATION...FS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1051 AM CST Sun Feb 9 2014 ...Updated Synopsis and Aviation sections... .SYNOPSIS... ISSUED AT 1049 AM CST SUN FEB 9 2014 The hemispheric pattern was characterized by a high zonal index with a couple of identifiable synoptic scale jet streaks within the pattern across the western third of the CONUS. The first of these jet streaks across the Northern Rockies led to light/moderate snow across western and central Nebraska this morning, as increased deformation acted on a tight baroclinic zone at 700mb (-18C at Rapid City vs. -2C at Denver). A cold front at 850mb was analyzed from the far northeastern portion of New Mexico through the southern Texas Panhandle into northern Oklahoma. Cold advection continued across southwest Kansas behind this front. The next upper level jet streak was quick on the heels of the aforementioned Northern Rockies jet streak...entering the Great Basin region this morning. This second jet streak will have an impact on southwestern Kansas weather tonight. && .SHORT TERM...(Today and tonight) ISSUED AT 343 AM CST SUN FEB 9 2014 Areas of locally dense freezing fog that developed over parts of central and western Kansas after sunset were propagating southwest behind the front into the far southwest part of the state early this morning. The last few runs of the RUC and HRRR visibility progs have been pretty consistent in moving the fog south and west into southeast Colorado and the Oklahoma/Texas panhandles by 12z. This looks reasonable given the dry air advection that is currently ongoing from north central into southwest Kansas. The dense fog advisory goes until 12z and will let it ride but continue to monitor for any areal or temporal extensions. Per SREF analysis and water vapor imagery, the first upper speed max was currently moving into the upper Mississippi Valley early this morning. The subsequent speed maxes will move out along the Kansas Nebraska border today and out over Kansas tonight. Associated mid level frontogenetic forcing will move out across Nebraska and far northern Kansas this morning and over Kansas tonight. Regional radar mosaic shows light snow already moving out of Wyoming into the Nebraska Panhandle and this will continue eastward across northern Kansas and Nebraska today. The current forecast has chance pops for light snow along the I-70 corridor today. Think any measurable snow will be north of the Dodge City forecast area today. The system moving out tonight should bring some accumulating snow to west central and parts of southwest and south central Kansas tonight. The models have been consistent with this so have increased pops well into the likely category tonight. The NAM is showing a swath of 1-2 inch snowfall generally north of Highway 50 tonight. Have increased snowfall amounts a little but for now think we will not see enough to warrant a winter weather advisory. Temperatures will not rise much, if at all, today given the ongoing cold air advection. Temperatures tonight should fall well down into the single digits above zero with a few low teens possible around Elkhart and Liberal. .LONG TERM...(Monday through Saturday) ISSUED AT 355 AM CST SUN FEB 9 2014 A weak shortwave trough will move through the Central Rockies along the zonal flow late Sunday. This shortwave will then move through Kansas on Monday. Convergence and mid level moisture will increase as this feature approaches. Mostly cloudy skies are anticipated throughout the day Monday with light to moderate snow showers. Precipitation chances end from west to east Monday evening into Monday night. Snow totals remain around 1 to 2 inches across the area. However, a few areas across west central and south central Kansas could see over 2 inches by the time the system exits the area. Surrounding offices and DDC have decided to not go with a winter weather advisory at this time and have the day shift see what the next model run suggests. Cloudy skies should continue Monday night with some clearing possible across west central Kansas towards sunrise. Winds will generally be from a northeasterly direction Monday as high pressure builds into the Plains. With the cloud cover and shot of cold air advection across the area, temperatures Monday are not expected to increase much from the morning lows. Highs Monday are forecasted to range from the lower teens across central Kansas to lower 20s across far southwestern Kansas. Lows Tuesday morning are expected to range from the negative single digits across central Kansas to around 10 degrees across far southwestern Kansas. However, if more clearing occurs overnight, temperatures could end up lower than what the current forecast depicts. The dome of high pressure moves east of the area on Tuesday shifting winds to the southwest. A few low level clouds may continue in the morning across south central Kansas Tuesday morning. Otherwise expect partly cloudy skies and dry conditions. The Central High Plains will then be stuck in between an upper level ridge across the western US and an upper level long wave trough across the eastern United states throughout the remainder of the forecast period. A few weak shortwaves are progged to move north of the area, but do not look to bring any precipitation across southwest Kansas at this time. Only a few clouds are expected to be observed throughout this period with dry conditions. Winds will generally be from the west but shift slightly to the north or south as the aforementioned shortwaves move north of southwest Kansas. We will finally begin the slow warming up process Tuesday through Saturday, however the snowpack across much of the region will need to be knocked out quite a bit before we realize maximum potential based on typical downslope mix-down scenarios. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 1049 AM CST SUN FEB 9 2014 Latest indications are that ceilings will remain in the IFR category with average ceiling in the 600 to 1000 foot range at DDC and GCK. HYS will likely stay in MVFR for the remainder of the day until light snow begins to affect the terminal this evening. Light to occasionally moderate snow will move in mid-evening and persist for a 6-9 hour period across portions of southwest Kansas, including GCK and DDC terminals. During the heaviest period of snow, flight category of LIFR or perhaps briefly VLIFR can be expected overnight. Following the snow early Monday morning, ceiling will remain a problem with flight category likely staying in IFR, especially GCK and DDC. && .PRELIMINARY POINT TEMPS/POPS... DDC 20 8 15 4 / 20 60 60 20 GCK 20 8 17 6 / 30 60 50 20 EHA 24 12 23 12 / 20 30 30 20 LBL 23 12 20 8 / 20 40 40 20 HYS 18 5 12 0 / 30 60 40 20 P28 25 9 16 4 / 30 60 60 30 && .DDC WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY from 8 PM this evening to 9 AM CST Monday FOR KSZ043>046-062>066-077>081. && $$ SYNOPSIS...Umscheid SHORT TERM...Gerard LONG TERM...Hovorka_42 AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 PM EST SUN FEB 9 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM EST SUN FEB 9 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER THE UPR LKS TO THE SW OF CORE OF ARCTIC AIR SITUATED OVER QUEBEC. RIBBON OF MUCH STRONGER W FLOW IS EVIDENT OVER THE S 2/3 OF THE CONUS. A FAIRLY STRONG DISTURBANCE EMBEDDED IN THIS FASTER FLOW IS MOVING THRU CENTRAL WI EARLY THIS MRNG. ACCOMPANYING PCPN HAS REACHED AS FAR N AS GRB OR SO...BUT OVERALL DRY AIRMASS IN PLACE WITH PWAT NO HIER THAN 0.10 TO 0.15 INCH IS LIMITING THE IMPACT OVER UPR MI TO JUST SOME MID CLD DESPITE PRESENCE OF AREA OF ACCOMPANYING H85-5 QVECTOR CNVGC. LGT WINDS AND LO PWAT HAVE ALLOWED TEMPS TO FALL BLO ZERO AT MOST PLACES DESPITE THESE CLDS. THERE ARE SOME LK CLDS NEAR SUPERIOR WITH H85 TEMPS ARND -20C DESPITE LGT NW FEED OF DRY LLVL AIR SHOWN ON THE 00Z INL RAOB AND EXTENSIVE ICE COVER. THE MQT RADAR DOES SHOW A FEW HIER RETURNS OVER SCENTRAL LK SUP...SO THERE ARE PROBABLY SOME ISOLD -SHSN DESPITE THESE NEGATIVES FOR LES. LOOKING UPSTREAM...THERE IS A SHRTWV OVER SW SASKATCHEWAN AND ANOTHER DROPPING SWD NEAR LK WINNIPEG. MAIN FCST CONCERNS IN THE SHORT TERM ARE LIMITED POPS ASSOCIATED WITH ARRAY OF SHRTWVS MENTIONED ABOVE AND TEMPS. TODAY..AREA OF QVECTOR CNVGC ASSOCIATED WITH SHRTWV MOVING TO THE S IS FCST TO MOVE E THIS MRNG AND EXIT THE AREA SOON AFTER SUNRISE. SO ACCOMPANYING MID CLD COVER SHOULD SHIFT TO THE E AS DRIER MID LVL AIR FOLLOWS. BUT THE SHRTWV OVER SW SASKATCHEWAN IS FCST TO TRACK INTO SCENTRAL WI LATE THIS AFTN...WITH AREA OF H85-5 QVECTOR CNVGC ARRIVING THIS AFTN OVER UPR MI. GIVEN THE ABSENCE OF ANY MSTR INFLOW WITH LLVL NW FLOW IN THE WAKE OF DEPARTING FIRST DISTURBANCE... SUSPECT THE IMPACT FOR THE CWA WL BE THE SAME AS WHAT IS HAPPENING NOW...JUST SOME MID CLD. SO HAVE OPTED TO REMOVE POPS...AT LEAST AWAY FM LK SUP. THE MAIN CONCERN IS HOW MUCH LK EFFECT PCPN THERE MAY OR MAY NOT BE. MOST OF THE HI RES MODELS ARE SHOWING NO PCPN NEAR THE LK THRU THE DAY...WITH ICE COVER...ABSENCE OF CYC FLOW /IN FACT SHOWING ACYC FLOW/...AND LLVL DRY ADVECTION SUPPRESSING THIS ACTIVITY. ON THE OTHE HAND...THE LOWER RES GFS/ECMWF LIGHT QPF SUGGEST SOME SHSN IN THE NW WIND SN BELTS. THE GFS ICE ANALYSIS DOES SHOW A REASONABLE AMOUNT OF OPEN WATER OVER CENTRAL LK SUP WHILE THE NAM/GEM INDICATE A COMPLETELY COVERED LK. SINCE THERE HAVE BEEN SOME BREAKS IN THE ICE RECENTLY AND THERE ARE AND HAVE BEEN SOME LGT SHSN AS WELL...WL TEND TOWARD THE LO RES MODELS AND INCLUDE SOME LO CHC POPS IN THE FAVORED SN BELTS THRU THE DAY AS THE LLVL NW FLOW DROPS H85 TEMPS TO ARND -23C BY 00Z MON OVER THE W. THIS CAD SHOULD KEEP MAX TEMPS LOWER THAN YDAY...WITH THE HIER TEMPS OVER THE SCENTRAL WITH SOME DOWNSLOPE FLOW AND PROBABLY SOME SUNSHINE BTWN THE SHRTWVS. TNGT...SHRTWV NOW NEAR LK WINNIPEG IS PROGGED TO DROP SEWD AND OVER UPR MI BY 12Z MON AS WI DISTURBANCE SHIFTS INTO THE LOWER LKS. THIS QUICK PROGRESSION OF SHRTWVS IS FCST TO MAINTAIN SOME DEEP LYR QVECTOR CNVGC THRU THE NGT...SO THERE WL PROBABLY BE QUITE A BIT OF AT LEAST MID/HI CLD EVEN OVER THE INTERIOR EVEN THOUGH LLVL DRYING SHOULD PREVENT ANY PCPN THERE. CLOSER TO LK SUP...WL MAINTAIN SOME LOWER CHC POPS FOR LES WITH H85 TEMPS FALLING TOWARD -24C DESPITE FCST NEUTRAL/ACYC NW FLOW AND CONSIDERABLE ICE COVER. THE GFS SHOWS STRONGER LLVL WINDS THAN THE OTHER MODELS...BUT OUT OF PHASE SHRTWVS/EXTENSIVE ICE COVER THAT WL LIMIT PRES FALLS OVER THE OPEN WATER AND SHARPNESS OF THE PRES GRADIENT INDICATE THE WEAKER WINDS SHOWN BY THE BULK OF THE OTHER GUIDANCE ARE ON THE RIGHT TRACK. THIS DIFFERENCE IN WIND SPEEDS COULD BE CRITICAL IN DETERMINING WHETHER WIND CHILLS WL REACH ADVY THRESHOLDS AS SFC TEMPS FALL WELL BLO ZERO...ESPECIALLY OVER THE W HALF. WITH THE WEAKER WINDS...EXPECT NEITHER THE WIND CHILLS NOR THE WIND SPEEDS WL BE SUFFICIENT FOR AN ADVY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 303 AM EST SUN FEB 9 2014 AFTER STARTING THE LONG TERM PERIOD UNDER A COLD NORTHERN STREAM TROUGH...IT/S DEPARTURE ON MONDAY NIGHT WILL LEAD TO A MORE PROGRESSIVE AND WARMER PATTERN FOR THE REST OF THE WORK WEEK AND INTO NEXT WEEKEND. WITH COLD 850MB TEMPS (-24C) UNDER THE UPPER TROUGH ON MONDAY...THERE WILL BE PLENTY OF OVER LAKE INSTABILITY FOR LAKE EFFECT IN THE AREAS THAT HAVE OPEN WATER. BUT MODIS SATELLITE FROM TODAY SHOWS THAT THOSE AREAS ARE VERY LIMITED...BUT THERE WERE STILL PERIODS OF CLOUDS AND LIGHT LAKE EFFECT OVER THE LAST DAY. THUS...WILL CONTINUE TO FOLLOW PREVIOUS SHIFTS OF SLIGHT AND CHANCE POPS IN THE NORTHWEST WIND FAVORED LOCATIONS DURING THE DAY ON MONDAY. WITH THE AMOUNT OF COLD AIR PRESENT...ALONG WITH LIMITED OPEN WATER...DON/T THINK SNOW WILL AMOUNT TO MUCH...UNLESS SOME WATER OPENS UP MORE THAN CURRENTLY SEEN. SINCE THERE WILL BE ABUNDANT MOISTURE ROTATING THROUGH THE CWA (CURRENTLY BETWEEN LAKE WINNIPEG AND HUDSON BAY)...WILL GO WITH MOSTLY CLOUDY SKIES OVER MUCH OF THE CWA. MONDAY WILL BE ONE OF THE COLDER DAYS FOR THE FORESEEABLE FUTURE...WITH HIGHS OVER THE WEST IN THE LOW SINGLE DIGITS ABOVE ZERO AND MID-UPPER SINGLE DIGITS ELSEWHERE. UPPER TROUGH WILL QUICKLY SHIFT EAST ON MONDAY NIGHT AND ALLOW RIDGING TO BUILD INTO THE AREA AT THE SURFACE AND ALOFT. THE SURFACE RIDGE...FROM THE HIGH SLIDING THROUGH THE UPPER MISSISSIPPI VALLEY...WILL LEAD TO DRIER AIR...WARMING ALOFT...AND WEAKENING/BACKING WINDS WHICH WILL DIMINISH THE SNOW CHANCES FROM WEST TO EAST THROUGH THE NIGHT AND INTO TUESDAY MORNING. WITH THE DRY RIDGE MOVING IN ON MONDAY NIGHT...SHOULD SEE INLAND TEMPERATURES REALLY FALL WERE SKIES CLEAR OUT. GOING FORECAST HAS OVERNIGHT LOWS NEAR THE WISCONSIN BORDER NEAR -20F AND THAT SEEMS FAIRLY REASONABLE. DIDN/T MAKE MANY CHANGES TO THOSE VALUES...SINCE SOME OF THE COLDER MODELS EVEN HAVE VALUES AROUND -24F AND BASED OFF SOME OF THE COLD SPOTS THE LAST COUPLE NIGHTS IT DOESN/T SEEM TOO UNREASONABLE. WITH TEMPERATURES THIS COLD...IT WON/T TAKE MUCH FOR WIND CHILLS TO NOSE INTO THE ADVISORY CRITERIA. BUT WITH WINDS LOOKING TO BE WELL BELOW 10MPH...SHOULD NOT NEED A WIND CHILL ADVISORY. THE HIGH PRESSURE RIDGE WILL SHIFT EAST OF THE REGION ON TUESDAY AND LEAD TO SOUTHWESTERLY FLOW DEVELOPING OVER THE AREA. THIS WILL START A WARMING TREND THAT WILL BRING TEMPERATURES CLOSER...BUT STILL BELOW NORMAL...FOR THE REST OF THE WORK WEEK. THE FIRST IN A SERIES OF SHORTWAVE TO AFFECT THE REGION IN THE NEARLY ZONAL FLOW WILL MOVE THROUGH THE UPPER GREAT LAKES ON TUESDAY NIGHT. SOME DISCREPANCY IN THE MODELS ON THE WHERE THE PIECES OF ENERGY TRACK...BUT THE GENERAL IDEA IS FOR SOME ENERGY TO MOVE THROUGH ON TUESDAY NIGHT AND THEN A COLD FRONT ASSOCIATED WITH A LOW OVER HUDSON BAY TO SWEEP THROUGH ON WEDNESDAY. HAVE FOLLOWED THAT IDEA FOR A WEST TO EAST PUSH OF CHANCE POPS THROUGH THE CWA. OVERALL...LOOKS LIKE A DUSTING TO 2 INCHES OF SNOW ON TUESDAY NIGHT AND WEDNESDAY. THE NEXT SHORTWAVE MOVES THROUGH THE NORTH CENTRAL CONUS ON THURSDAY AND ONCE AGAIN THERE ARE DIFFERENCES IN THE MODELS. THIS TIME...THE GFS/GEM ARE IN DECENT AGREEMENT WITH THE SHORTWAVE INTENSIFYING THE LOW MOVING THROUGH THE NORTHERN PLAINS AND TRACKING IT THROUGH THE UPPER GREAT LAKES THURSDAY AND THURSDAY NIGHT. THE ECMWF ON THE OTHER HAND TRACKS A WEAKER LOW FARTHER SOUTH AND SLOWER THROUGH THE LOWER GREAT LAKES. ALL IN ALL...IT APPEARS THAT THERE WILL BE SOME DISTURBANCE AFFECTING THE AREA DURING THE SECOND HALF OF THE WORK WEEK. WITH THE TRADITIONAL FASTER GFS AND SLOWER ECMWF SOLUTIONS USUALLY MERGING AND SPLITTING THE DIFFERENCES...THINK THE AREA WILL POTENTIALLY EXPERIENCE NEAR ADVISORY SNOWFALL AROUND THE THURSDAY INTO THURSDAY NIGHT PERIOD. WILL KEEP POPS AT THE CHANCE CATEGORY UNTIL MODELS COME INTO BETTER AGREEMENT ON THE TIMING. BEHIND THAT DISTURBANCE...MODELS SHOW A HIGH PRESSURE RIDGE MOVING INTO THE AREA AND PRODUCE A DRY FRIDAY BEFORE ANOTHER SHORTWAVE APPROACHES WISCONSIN ON SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1239 PM EST SUN FEB 9 2014 NW FLOW WILL LINGER AT THE SFC AND ALOFT THROUGH 18Z MONDAY. HOWEVER...A SLIGHTLY MORE WNW PUSH OF WIND TOWARD IWD SHOULD ALLOW MUCH OF THE LOWER CLOUDS TO PUSH N OF THE SITE WITH MVFR CEILINGS REMAINING DOMINANT. CMX WILL TAKE THE BRUNT OF THE LOWER CLOUDS AND LOWER VIS WITH -SHSN AS SAW IS IN A MORE DOWNSLOPE FLOW REGIME WITH THIS WIND DIRECTION. A SERIES OF DISTURBANCES WILL STILL KEEP VFR TO HIGH END MVFR CEILINGS OFF AND ON AT BOTH IWD AND SAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 1239 PM EST SUN FEB 9 2014 LITTLE POTENTIAL FOR FREEZING SPRAY REMAINS DUE TO THE WINDS LINGERING AROUND 25KTS OR LESS THROUGH THE PERIOD...AND MAINLY DUE TO THE EXTENSIVE ICE COVER ACROSS LAKE SUPERIOR. AS LOW PRESSURE MOVES OFF THE NEW ENGLAND SEABOARD TONIGHT...A HIGH ACROSS CENTRAL CANADA AND THE N PLAINS WILL CONTINUE TO SINK SE. EXPECT A RIDGE TO SET UP ACROSS LAKE SUPERIOR LATE TONIGHT THROUGH TUESDAY AFTERNOON AS THE MAIN HIGH SINKS ACROSS THE MID MS VALLEY TUESDAY...AND EXITS ACROSS THE NEW ENGLAND STATES ON WEDNESDAY. LOW PRESSURE ACROSS ND TUESDAY AFTERNOON WILL SHIFT NE TO S HUDSON BAY WHILE DRAGGING A TROUGH ACROSS LAKE SUPERIOR ON WEDNESDAY. ANOTHER LOW LOOKS TO MOVE FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO THE UPPER GREAT LAKES ON THURSDAY...HOWEVER THERE IS RELATIVELY LOW CONFIDENCE IN THE FCST ACROSS LAKE SUPERIOR FOR THURSDAY THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...KF MARINE...KF
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1233 PM EST SUN FEB 9 2014 .SYNOPSIS... A FAST MOVING UPPER DISTURBANCE WILL BRING A BRIEF PERIOD OF SNOW THIS MORNING AND MOVE OFF TO THE EAST BY EARLY AFTERNOON. THEN ANOTHER SURGE OF ARCTIC AIR WILL SPREAD ACROSS THE REGION FOR THE FIRST HALF OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FORCING ASSOCIATED WITH A SHORTWAVE AND WEAK SURFACE TROUGH HAS LED TO WIDESPREAD SNOW ACROSS THE NWS ILN FORECAST AREA. WEAK FRONTOGENESIS ON THE BACK SIDE OF THE SURFACE TROUGH (WHERE COLD ADVECTION IS BEGINNING) HAS LED TO SOME SMALL AREAS OF ENHANCEMENT. ONE BAND THAT SET UP ACROSS THE NORTH-CENTRAL FORECAST AREA PRODUCED VISIBILITIES OF 1/4 MILE AND QUICK ACCUMULATIONS OF TWO (EVEN UP TO THREE) INCHES. ASIDE FROM JUST THE SNOW...VISIBILITIES ARE LOW AROUND THE AREA ANYWAY...WITH SOME MIST OR FOG ALSO PRESENT. WITH THE ATMOSPHERE BECOMING MORE SATURATED AS THE SNOW HAS BEGUN...FREEZING DRIZZLE APPEARS TO HAVE ENDED. THE HRRR HAS PICKED UP ON THE ENHANCED AREA OF SNOW OVER SOUTH- CENTRAL OHIO QUITE NICELY...AND SNOWFALL TOTALS HAVE BEEN INCREASED FOR THESE LOCATIONS. OTHERWISE...ADJUSTMENTS TO THE FORECAST WERE MINOR. THE BACK EDGE OF THE STEADY SNOWFALL IS NOW ENTERING THE ILN CWA...THOUGH FLURRIES ARE NOTED ON SURFACE OBS THROUGHOUT MOST OF INDIANA. PREVIOUS DISCUSSION > FREEZING DRIZZLE WILL START OUT THE NEAR TERM. SNOW EXTENDING FROM NORTHERN INDIANA INTO CENTRAL ILLINOIS WILL QUICKLY MAKE ITS WAY ACROSS THE FORECAST AREA THIS MORNING AND THEN CLEAR OFF TO THE EAST BY EARLY AFTERNOON. ACCUMULATIONS WILL BE GREATEST NORTH OF I-70 WHERE FORCING IS A BIT BETTER AND SNOW MAY LAST FOR SEVERAL HOURS. EXPECT 1 TO 2 INCHES THERE. FURTHER SOUTH SNOW WILL ONLY OCCUR FOR A BRIEF TIME AND MAY NOT EVEN MAKE IT INTO NORTHERN KENTUCKY. ACCUMULATIONS WILL BE LESS HEADING SOUTH WITH ONLY A DUSTING NEAR THE OHIO RIVER. HIGHS FORECAST CLOSE TO MOS CONSENSUS. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THE SHORT TERM BRINGING ANOTHER REINFORCEMENT OF ARCTIC AIR. ANOTHER FAST MOVING IMPULSE TONIGHT SHOULD BE SUPPRESSED SOUTH OF THE FORECAST AREA ALTHOUGH HAVE LEFT SLIGHT CHANCE POPS IN THE FAR SOUTHERN COUNTIES. OTHERWISE IT WILL BE DRY. HAVE GENERALLY TRENDED TEMPERATURES TOWARDS COLDER GFS MOS. WITH COLD TEMPERATURES AND EVEN JUST LIGHT WINDS CONTINUING INTO THE NIGHTTIME PERIODS... WIND CHILL VALUES WILL BE NEAR OR BELOW WIND CHILL ADVISORY THRESHOLD FOR NORTHERN COUNTIES MONDAY NIGHT. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS SHOWING QUITE A BIT OF VARIABILITY IN TIMING AND AMPLIFICATION OF SHORT WAVES THROUGHOUT THE LONG TERM. THERE REMAINS THE POTENTIAL FOR SYSTEM PASSING JUST SOUTHEAST OF THE FORECAST AREA LATE WEDNESDAY INTO THURSDAY. IT DOES APPEAR THAT A COLD FRONT WILL MOVE THROUGH LATER IN THE WEEK ALTHOUGH THERE IS TIMING UNCERTAINTY WHETHER POTENTIAL IMPACTS WILL BE THURSDAY OR FRIDAY. THERE IS BROAD AGREEMENT THAT ANOTHER SYSTEM WILL PUSH THROUGH THE REGION ON SATURDAY. TEMPERATURES SHOULD BE ABLE TO MODERATE ALTHOUGH STILL REMAIN SLIGHTLY BELOW NORMAL FOR THE LATTER PART OF THE WEEK. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... BY 18Z...THE ACCUMULATING SNOW IS EXPECTED TO BE COMPLETED AT ALL OF THE TAF SITES. WHILE LIGHT SNOW MAY KEEP SLIGHTLY REDUCED VISIBILITIES FOR THE NEXT HOUR OR TWO AT COLUMBUS...THE REST OF THE TAFS WILL REMAIN DRY. CLEARING IS WORKING INTO INDIANA...BUT MVFR CEILINGS ARE EXPECTED TO REMAIN IN PLACE THROUGH AT LEAST THE NEXT FEW HOURS. THE VFR CEILING FORECAST FOR THE REST OF THE TAFS IS A LITTLE BIT UNCERTAIN...BUT FORECAST TRENDS ARE POINTING TOWARD A SCOURING OF THE LOW-LEVEL MOISTURE...WHICH SHOULD LEAVE ONLY PATCHES OF MVFR CLOUDS IN SOME LOCATIONS. OUTLOOK...MVFR CEILINGS AND VISIBILITIES ARE POSSIBLE ON THURSDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS... NEAR TERM...HATZOS SHORT TERM... LONG TERM... AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
249 PM PST SUN FEB 9 2014 .DISCUSSION...THE NEXT LOW PRESSURE WAVE IS MOVING INTO NORTHERN CAL AND RADAR RETURNS ARE ALREADY SHOWING STEADY MODERATE TO HEAVY PRECIPITATION MOVING INTO NORTHERN CAL. THE MODELS ARE IN FAIRLY GOOD AGREEMENT KEEPING MOST OF THE SIGNIFICANT PRECIPITATION IN NORTHERN CAL. THE RAP SHOWS SOME LIGHT QPF SNEAKING INTO SOUTHERN OREGON THIS EVENING, BUT DON`T EXPECT MUCH MORE THEN A FEW TICKS ON THE RAIN GAGE. THE LOW PRESSURE WAVE WILL QUICKLY ZIP EAST AND WE`LL SEE STEADY PRECIPITATION DECREASE FROM WEST TO EAST TONIGHT. ELSEWHERE, I`M NOT EXPECTING MUCH IF ANY PRECIPITATION. WEAK RIDGING WILL BUILD INTO THE AREA TONIGHT AND KEEP MOST LOCATIONS DRY IN SOUTHERN OREGON. A WEAK FRONT WILL REACH THE COAST MONDAY MORNING BRINGING LIGHT PRECIPITATION MAINLY ALONG THE COAST RANGE...NORTHWEST DOUGLAS COUNTY AND NORTHERN CASCADES. NORTHERN CAL AND MUCH OF THE EASTSIDE SHOULD REMAIN DRY WITH MIXED CLOUDS AND SUN. THE FRONT WILL GET HUNG UP OVER THE NORTHERN PART OF THE FORECAST AREA MONDAY NIGHT AND REMAIN NEARLY STATIONARY THROUGH TUESDAY MORNING. THEREFORE HAVE KEPT A SLIGHT CHANCE TO CHANCE POPS THERE. ELSEWHERE I`M FAIRLY CONFIDENT WE`LL REMAIN DRY. OF BIGGER CONCERN WILL BE TUESDAY NIGHT THROUGH WEDNESDAY WITH THE POTENTIAL FOR MODERATE TO STRONG WINDS ALONG THE COAST AND MODERATE TO HEAVY PRECIPITATION. THE EC AND GFS ARE IN PRETTY GOOD AGREEMENT WITH A SURFACE LOW DEVELOPING ON TUESDAY AND TRACKING NORTHEAST INTO VANCOUVER ISLAND WEDNESDAY MORNING WITH A TROPICAL CONNECTION AIMED RIGHT AT US. THE GFS SHOWS 925 MB WINDS PUSHING 65 KTS MAINLY NORTH OF CAPE BLANCO EARLY WEDNESDAY MORNING WITH A SOUTH TO SOUTHWEST COMPONENT. IF THIS REMAINS CONSISTENT, THEN WE COULD BE LOOKING A HIGH WINDS FOR THE NORTH COAST. AT THE SAME TIME, MODERATE TO HEAVY PRECIPITATION WILL IMPACT THE COAST RANGE OVERNIGHT TUESDAY AND CONTINUE THROUGH WEDNESDAY NIGHT BEFORE GRADUALLY DECREASING. IT WOULD NOT BE OUT OF THE QUESTION TO HAVE PRECIP AMOUNTS BETWEEN 4-6 INCHES ALONG THE SOUTH COAST RANGE, 2-4 INCHES ALONG THE CASCADES AND 1-2 INCHES IN THE WESTSIDE VALLEYS. KEEP IN MID THIS IS STILL A WAYS OUT AND THE SPECIFICS OF PRECIPITATION TOTALS COULD CHANGE. EVEN THOUGH RIVER FLOWS HAVE BEEN LOW, THEY WILL COME UP AND IF WE GET A SUSTAINED PERIOD OF MODERATE TO HEAVY PRECIPITATION, THEY WILL COME UP AND IF NOTHING ELSE WE COULD BE LOOKING AT RAPID RISES ALONG SOME OF THE SMALL STREAMS AND RIVERS. SNOW LEVELS DURING THIS TIME WILL BE HIGH (BETWEEN 7500 AND 8000 FEET) ON WEDNESDAY -PETRUCELLI .LONG TERM...THURSDAY THROUGH SUNDAY. MODELS HAVE SHOWN RUN TO RUN VARIABILITY WITH THE DETAILS OF THE FRONTS EXPECTED THURSDAY THROUGH SUNDAY. HOWEVER THERE IS HIGH CONFIDENCE THAT THE OVERALL PATTERN WILL BE WET AS THE JET STREAM REMAINS OVER THE REGION AND FRONTS MOVE INTO THE AREA AROUND A LOW CENTERED NEAR THE GULF OF ALASKA. THE 12Z MODELS INDICATE THAT THE FRONT ON WEDNESDAY MAY LINGER OVER THE AREA INTO THURSDAY. ADDITIONALLY A WEAK FRONT IS EXPECTED TO MOVE INTO THE PACNW EARLY THURSDAY FOLLOWED BY A STRONG FRONTAL SYSTEM THURSDAY NIGHT INTO FRIDAY. DURING THIS PERIOD, MODELS ARE ALSO INDICATING A PERSISTENT TROPICAL MOISTURE CONNECTION AIMED AT THE AREA. THE GFS AND GEFS SHOW GOOD MOISTURE TRANSPORT ORIGINATING FROM NEAR HAWAII AND EXTENDING NORTHEAST TO THE SOUTHERN OREGON COAST. THIS PATTERN IS EXPECTED TO BRING MODERATE TO HIGH PRECIPITATION WITH HIGH SNOW LEVELS, MAINLY ABOVE 6000 FEET. ALSO AS THE STRONG FRONT MOVES INLAND, GUSTY WINDS ARE POSSIBLE ACROSS THE AREA WITH THE STRONG WINDS OVER THE MOUNTAINS AND INTO THE SUMMER LAKE AND SHASTA VALLEY AREAS THURSDAY AFTERNOON INTO EARLY FRIDAY. CONFIDENCE IS LOWER WITH HOW QUICKLY THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL MOVE INLAND THURSDAY NIGHT INTO FRIDAY. THE ECMWF IN PARTICULAR LINGERS THIS FRONT OVER THE AREA. THIS COMBINED WITH GOOD MOISTURE WOULD PROVIDE THE POTENTIAL FOR ADDITIONAL MODERATE TO LOCALLY HEAVY RAINFALL OVER THE AREA. MEANWHILE THE GFS AND GEFS PUSH THE FRONT INLAND FRIDAY WITH LIGHT TO MODERATE SHOWERS LINGERING INTO FRIDAY EVENING. OF CONCERN WILL BE THE POTENTIAL FOR HEAVY RAINFALL AND INCREASED RIVER AND STREAM FLOWS DURING THIS PERIOD. THEN ON SATURDAY, MODEL SOLUTIONS INDICATE THAT ANOTHER MODERATE TO STRONG FRONT MAY IMPACT THE AREA. THE GFS, GEFS AND ECMWF ALL SHOW A LOW PRESSURE CENTER MOVING TOWARDS THE PACNW COAST EARLY SATURDAY THEN INLAND SATURDAY NIGHT. THE EMCWF DEPICTS THE LOW CENTER FURTHER SOUTH THAN THE GFS AND WOULD SUPPORT AND INCREASED CHANCE FOR STRONG WINDS OVER THE AREA SATURDAY. BEHIND THIS FRONT EXPECT SOME LINGERING SHOWERS SATURDAY NIGHT INTO SUNDAY. ALSO MODEL SOLUTIONS SHOW GOOD AGREEMENT THAT SNOW LEVELS WILL LOWER SATURDAY NIGHT INTO SUNDAY, POSSIBLY DOWN TO 3500 TO 4000 FEET. /CC && .AVIATION...BASED ON THE 09/18Z TAF CYCLE. A LOW PRESSURE WILL MOVE INLAND INTO NORTHERN AND CENTRAL CALIFORNIA THIS AFTERNOON INTO TONIGHT. AREAS OF MVFR CIGS AND RAIN ACROSS NORTHERN CALIFORNIA ARE EXPECTED TO BECOME WIDESPREAD THIS EVENING INTO TONIGHT. RAIN WILL DIMINISH BY MONDAY MORNING BUT VALLEYS IN NORTHERN CALIFORNIA MAY CONTINUE TO SEE AREAS OF IFR/MVFR CIGS MONDAY MORNING. LIGHT RAIN WILL OCCASIONALLY SPREAD INTO SOUTHERN OREGON THIS EVENING AND CIGS MAY DROP TO MVFR IN SHOWERS. WITH PLENTY OF LOW LEVEL MOISTURE...LOW CLOUDS COULD FORM IN VALLEY LOCATIONS TONIGHT INTO MONDAY MORNING WITH MVFR/IFR CIGS POSSIBLE. ALSO EXPECT MVFR/IFR CIGS TO REDEVELOP ALONG THE COAST TONIGHT AND PERSIST INTO MONDAY MORNING. /CC && .MARINE...THE AREA WILL REMAIN BETWEEN SYSTEMS TODAY WITH A STATIONARY FRONT TO THE NORTH AND A LOW WILL MOVING INLAND TO THE SOUTH. A WEAK FRONT IS EXPECTED TO MOVE ACROSS THE COASTAL WATERS MONDAY. THEN EXPECT SEVERAL STRONGER FRONTS TO MOVE INTO THE WATERS LATE TUESDAY THROUGH SATURDAY. THE FIRST OF THESE FRONTS IS EXPECTED TO MOVE TOWARDS THE AREA TUESDAY AND ACROSS THE WATERS TUESDAY NIGHT INTO EARLY WEDNESDAY. THIS SYSTEM WILL BRING THE POTENTIAL FOR GALE FORCE WINDS AND VERY STEEP WIND DRIVEN SEAS TUESDAY EVENING AND NIGHT. WESTERLY SWELL IS EXPECTED TO INCREASE WEDNESDAY AND GRADUALLY LOWER ON THURSDAY. THIS IS EXPECTED TO BRING CONTINUED VERY STEEP TO STEEP SEAS TO THE WATERS THROUGH THURSDAY. ADDITIONAL FRONTS ARE POSSIBLY LATE IN THE WEEK WITH ANOTHER STRONG FRONT POSSIBLE SATURDAY. /CC && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PACIFIC COASTAL WATERS...NONE. $$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
900 AM PST SUN FEB 9 2014 .SYNOPSIS...HIGH PRES E OF THE CASCADES WILL KEEP A COLD EAST FLOW THROUGH THE GORGE INTO MON MORNING. A FRONTAL SYSTEM WILL BRING INCREASED CHANCES FOR PRECIPITATION LATE TODAY AND TONIGHT...WITH A CONTINUED THREAT FOR SOME FREEZING RAIN OR SNOW IN AND NEAR THE GORGE. MORE SEASONABLE AIR WILL RETURN LATER MON AND REMAIN THROUGH THE WEEK AS A SERIES OF SYSTEMS MOVES IN OFF THE PACIFIC BRINGING PERIODIC CHANCES FOR RAIN. && .UPDATE...ALSO WILL ADD THE FOG INTO THE GRIDS AND CUT TEMPS. WARM ADVECTION OVER COLD SNOW PACK WILL LEAD TO WIDESPREAD STRATUS AND FOG AND WILL KEEP TEMPS IN CHECK. PLUS WITH NO SE GRADIENT UNTIL OVERNIGHT THERE IS NO REAL WARM UP EXPECTED UNLESS THERE WERE CLOUD BREAKS WHICH LOOK UNLIKELY. THIS HAS IMPLICATIONS FOR OTHER PARTS OF THE VALLEY FOR TOMORROW MORNING AS FAR AS FREEZING RAIN CHANCES...INCLUDING ANY COLD AIR BANKED UP ON THE WEST SIDE OF THE VALLEY. 925 MB BAROCLINIC ZONE IS DRAPED ACROSS THE AREA THIS MORNING WITH AN AREA OF ENHANCED MID LEVEL CLOUDS IN AN EAST WEST ORIENTATION EXTENDING FROM ABOUT SALEM/PORTLAND WESTWARD TO WELL OFFSHORE. THE BAROCLINIC ZONE IS A BIT MORE DIFFUSE FARTHER SOUTH...BUT THERE IS ENOUGH PACIFIC ENERGY THAT IS CONTRIBUTING TO SOME VERY LIGHT SHOWER ACTIVITY SOUTH WHERE TEMPERATURES ARE GENERALLY 31-34....AND CONTINUED AREAS OF FREEZING DRIZZLE FROM SALEM NORTHWARD WHERE READINGS ARE STILL GENERALLY IN THE 20S. THE SALEM SOUNDING DOES SHOW A VERY LOW LEVEL WARM NOSE WITH THE TOP OF THE MOIST LAYER AT -7C SO NOT VERY DEEP SATURATION...AND KPTV TOWER TEMP AT 1800 FEET SHOWS 34F...SO AT LEAST CONFIDENCE IS GOOD IN PRECIP TYPE BEING FREEZING RAIN/DRIZZLE. THE QUESTION OF THE DAY IS HOW MUCH OF THE PRECIPITATION AND APPROACHING SLIGHTLY DEEPER MOISTURE WITH THE BAROCLINIC ZONE WILL GRAZE THE NORTHERN HALF OF THE AREA THIS AFTERNOON...AND WHAT TEMPERATURES WILL DO. NOW FORTUNATELY MOST MODELS SUGGEST LIGHT QPF WITH THIS...FROM VERY LITTLE TO UP TO MAYBE 0.05".LATEST RAP AND HRRR KEEP THE DRIZZLE/LIGHT PRECIP GOING THROUGH THE MORNING AND INTO THE AFTERNOON...AND THEN AS THE WAVE OFFSHORE MOVES CLOSER THE BOUNDARY LIFTS NORTH LATER THIS AFTERNOON. WHAT THIS MEANS IS THAT THERE IS A CONTINUED CHANCE FOR LIGHT FREEZING RAIN/DRIZZLE THROUGH THE AFTERNOON...SO WILL EXTEND THE FREEZING RAIN ADVISORY INTO THE AFTERNOON. THERE ARE ALSO POCKETS OF COLD AIR STILL TRAPPED IN THE LOWER VALLEYS OF THE COAST RANGE...WILLAPA HILLS...AND THE INTERSTATE 5 CORRIDOR IN COWLITZ COUNTY...AND THE LOWER COLUMBIA SO WILL ALSO HAVE THE ADVISORY FOR THESE AREAS AS THE LIGHT PRECIPITATION CONTINUES. THERE MAY BE SOME MODERATION OF TEMPERATURES THOUGH AS THE DAY TO NEAR OR ABOVE FREEZING THOUGH NOT MUCH. MEANWHILE WITH WARM ADVECTION OVER THE SNOW PACK THERE IS SOME FOG AND VERY LOW STRATUS IN PLACE..WITH DENSE FOG AROUND EUGENE. AND FOG INCREASING THROUGH THE VALLEY. MODELS ARE IN GOOD AGREEMENT IN LIFTING THE MOISTURE NORTH THIS EVENING AND THEN WE GET A BREAK FOR MOST OF THE NIGHT BEFORE THE NEXT PACIFIC SYSTEM ARRIVES LATE TONIGHT INTO MONDAY MORNING. SOUNDINGS IN PORTLAND SUGGEST THAT INITIAL P-TYPE MAY STILL BE FREEZING RAIN THROUGH AT LEAST 7 AM. YOU COULD REASONABLY ARGUE THAT THERE STILL COULD BE POCKETS OF TRAPPED COLD LOW LEVEL AIR JUST ABOUT ANYWHERE THAT WILL NOT BE SCOURED OUT BEFORE THIS SYSTEM COMES IN...WITH A HIGHER LIKELIHOOD NORTH. THE MORNING PRECIP IS LESS THAN ONE TENTH OF AN INCH BUT COULD FEASIBLY BE ALL FREEZING RAIN IN THE EAST METRO AREA...AND CONFINED EAST OF I-205 BY LATER MORNING. RAW SOUNDING GUIDANCE WHICH HAS BEEN SUSPECT TO THIS POINT WITH THE LOW LEVEL AIR WOULD SUGGEST THIS THREAT GOES AWAY BETWEEN 15Z-18Z AS THE PRECIP IS GOING IN...BUT THERE IS STILL AN EAST GRADIENT THROUGH THE GORGE...SO IT IS THE MORNING PERIOD THAT IS IN QUESTION. IT COULD BE SOONER BUT WELL HAVE TO WATCH THE SOUTH GRADIENT. THE GORGE CONTINUES A CHANCE INTO THE AFTERNOON BEFORE THE EAST GRADIENT GETS WASHED AWAY. /KMD && .SHORT TERM...DOPPLER RADAR AND SURFACE OBSERVATIONS INDICATE TEMPERATURES FOR MOST INTERIOR VALLEYS REMAIN AT OR JUST BELOW FREEZING EARLY THIS MORNING. TEMPERATURES HAVE CREPT BARELY ABOVE FREEZING IN EUGENE THOUGH...BUT SOUTH WINDS HAVE YET TO MATERIALIZE AND REALIZE THE WARMER TEMPERATURES ALOFT OVER THE SOUTH WILLAMETTE VALLEY. CONSIDERING MODELS ARE HANDLING THE SCOUR OUT OF THIS COLD POOL POORLY AROUND EUGENE...CONFIDENCE IN TIMING THE WARM UP ACROSS THE REST OF THE WILLAMETTE VALLEY TODAY REMAINS LOW. NONETHELESS...WITH CURRENT TEMPERATURES GENERALLY IN THE 31F TO 32F RANGE FOR THE CENTRAL VALLEY SOUTHWARD...CONFIDENCE IS HIGHER THAN FURTHER NORTH THAT MUCH OF THIS REGION WILL RISE ABOVE FREEZING LATER THIS MORNING. CLOSER TO PORTLAND...THE TEMPERATURE FORECAST IS MORE TRICKY WITH COLD AIR CONTINUING TO POOR OUT OF THE COLUMBIA RIVER GORGE WHERE TEMPERATURES ARE CURRENTLY IN THE UPPER 20S. THE KTTD-KDLS PRESSURE GRADIENT JUST DIPPED UNDER 5MB. MODELS SUGGEST IT WILL LOWER CLOSER TO 2MB THIS MORNING...WHICH IS LIKELY OVERDONE...ESPECIALLY CONSIDERING A WARM FRONT CURRENTLY NEAR 130W WILL BE APPROACHING THE REGION TODAY. AS A RESULT...I KEPT HIGH TEMPERATURES FOR AREAS EAST OF THE PORTLAND AIRPORT BELOW FREEZING...WELL BELOW MODEL GUIDANCE. AS THE AFOREMENTIONED 850MB WARM FRONT APPROACHES...PRESSURE GRADIENTS SHOULD TURN MORE SOUTHEASTERLY...WHICH MAY ALSO CAUSE COLD AIR TO BANK UP AGAINST THE COAST RANGE IN WESTERN WASHINGTON COUNTY...AND PERHAPS SOUTHWARD TOWARDS MCMINNVILLE. THIS COULD MAKE THESE LOCATIONS SUSCEPTIBLE TO STAYING BELOW FREEZING INTO SUNDAY NIGHT WHEN PRECIPITATION CHANCES INCREASE. AS A RESULT...I KEPT A CHANCE OF FREEZING RAIN IN THESE LOCATIONS THROUGH THIS PERIOD. IN THE MEANTIME...DOPPLER RADAR AND SURFACE OBSERVATIONS INDICATE FREEZING DRIZZLE CONTINUES ACROSS PORTIONS OF THE PORTLAND/VANCOUVER METRO AREA AND IN THE COLUMBIA RIVER GORGE. AS A RESULT...A FREEZING RAIN ADVISORY WILL BE ISSUED FOR THE METRO...AND A WINTER WX ADVISORY FOR THE WESTERN COLUMBIA RIVER GORGE WHERE GREATER UNCERTAINTY IN PRECIPITATION TYPE RESIDES. ICE OR SNOW AMOUNTS WILL BE LIGHT...LIKELY ONLY A COUPLE HUNDREDTHS OF AN INCH AT MOST...BUT THIS WILL NONETHELESS CONTINUE TO ADD THE MESS ALREADY IN PLACE. /NEUMAN WHATEVER COLD AIR HAS BEEN ABLE TO HOLD ON IN THE HOOD RIVER VALLEY AND THROUGH THE GORGE IS LIKELY TO FINALLY BE OVERWHELMED DURING THE DAY MON. OFFSHORE PRES GRADIENTS WHICH HOLD ON IN MOST MODELS THROUGH 12Z MON RELAX CONSIDERABLY DURING THE DAY AS A WARM FRONT PUSHES INLAND AND A SOUTHERLY GRADIENTS DEVELOPS. THE BEST CHANCES FOR PRECIPITATION HOWEVER APPEAR HEADED N OF THE FORECAST AREA WHERE ISENTROPIC LIFT IS MAXIMIZED. WILL KEEP MOST OF THE AREA WITH HIGH POPS THOUGH MON AS A WEAK COLD FRONT TRAILS THE WARM FRONT AND DIPS INTO NW OREGON IN THE AFTERNOON. MOIST ONSHORE FLOW KEEPS SOME THREAT OF RAIN IN MON NIGHT AND TUE. CHANCES FOR RAIN WILL BE INCREASING DURING THE DAY TUE AS MODEST ISENTROPIC LIFT DEVELOPS OVER A DEEP MOIST LAYER SEEN ON 290K AND 300K ISENTROPIC SURFACES. WITH A MORE ONSHORE FLOW PATTERN MON INTO TUE...WILL SEE A RETURN TO MORE NORMAL LIKE TEMPERATURES. .LONG TERM...AN ACTIVE WEATHER PATTERN CONTINUES THROUGH THE REST OF THE WEEK WITH A ZONAL FLOW OFF THE PACIFIC. THIS EFFECTIVELY SHOULD BRING WET WEATHER AT TIMES WITH TEMPS NEAR OR A LITTLE BELOW SEASONAL NORMALS. MODELS ARE IN PRETTY GOOD AGREEMENT IN BRINGING A RATHER WET LOOKING SYSTEM IN TUE NIGHT AND EARLY WED...ALTHOUGH THERE ARE CONSIDERABLE DIFFERENCES IN DETAILS LIKE THE TRACK OF THE SURFACE LOW AND THE EXACT TIMING OF THE FRONTS. A MORE SOUTHERLY LOW TRACK LIKE THE 06Z GFS RUN WOULD BRING SOME POTENTIAL FOR HIGH WINDS TO THE COAST...BUT CONSIDERABLE DOUBT REMAINS AT THIS POINT DUE TO MODEL VARIANCES. ANOTHER WET SYSTEM IS AGREED UPON AROUND THU NIGHT...SO WILL GO WITH HIGHEST POPS FOR THESE TWO SYSTEMS. BEYOND THAT MODELS STRUGGLE A BIT WITH AGREEING ON DETAILS...BUT OVERALL FEEL FROM THE REST OF THE EXTENDED IS THAT WEAKER SYSTEMS WITH PACIFIC MOISTURE WILL KEEP CHANCES FOR PRECIPITATION ABOVE CLIMATOLOGY INTO NEXT WEEKEND. && .AVIATION...PLENTY OF IFR AND MVFR ACROSS THE AREA THIS MORNING. COLD AIR AT THE SURFACE AND WARMER AIR ALOFT MAINTAINING NEARLY SATURATED LOWER LAYERS OF THE ATMOSPHERE. THESE LOWER FLIGHT CONDITIONS SHOULD PREVAIL THROUGH THE MORNING HOURS...WITH AREAS OF -FZDZ IN THE INTERIOR VALLEYS NORTH OF KSLE. THE WARMER AIR ALOFT WILL CONTINUE TO ERODE THE LOWER LAYER COLDER AIR TODAY...CONFINING ANY FREEZING PRECIP TO NEAR THE COLUMBIA GORGE...KPDX AND INTO SW WA. SHOULD SEE GRADUAL IMPROVEMENT TO MVFR AND LOW-END VFR THIS AFTERNOON. HOWEVER...A RETURN TO MVFR OR IFR THIS EVENING AND TONIGHT...WITH AREAS OF LIFR. MTNS AND HIGHER TERRAIN REMAIN OBSCURED THROUGH TONIGHT. KPDX AND APPROACHES...IFR THIS MORNING AND WILL CONTINUE THROUGH AT LEAST 18Z. INTERMITTENT -FZDZ THROUGH THE AFTERNOON...BUT CIGS LOOK TO IMPROVE INTO THE MVFR CATEGORY...AND POSSIBLY TO LOW-END VFR BY MID-AFTERNOON. HOWEVER...A RETURN TO MVFR THIS EVENING...AND THEN TO IFR OVERNIGHT. KTTD-KDLS GRADIENT -5 MB AT 16Z AND SHOULD HOVER AROUND THAT VALUE THROUGH THE DAY...RESULTING IN 20-30KT GUSTS AT THE WEST END OF THE GORGE. WEISHAAR && .MARINE...FAIRLY QUIET CONDITIONS ACROSS THE WATERS THIS MORNING. WIND SPEEDS HAVE FALLEN TO 15 KT OR LESS AND WILL STAY AT OR BELOW THAT LEVEL THROUGH THIS EVENING. NEXT WARM FRONT MOVES INTO THE WATERS THIS EVENING...AND BY MIDNIGHT SHOULD SEE WIND SPEEDS RAMP UP TO AROUND 20 KT WITH GUSTS 25-30 KT. SMALL CRAFT ADVISORY ALREADY IN PLACE. MUCH STRONGER SYSTEM ENTERS THE WATERS LATE TUE AFTERNOON WITH SOLID GALES DEVELOPING DURING THE EVENING. COULD SEE GUSTS UP TO 45 KT WITH THIS ONE. LONGER RANGE MODEL GUIDANCE SHOWS ANOTHER SYSTEM LATE IN THE WEEK FOR ANOTHER ROUND OF HIGH- END SMALL CRAFT ADVISORY OR EVEN GALE WIND SPEEDS. SEAS TO STAY AROUND 5-6 FT THROUGH TONIGHT BUT RISE ABOUT 10 FT TUE. MODEL GUIDANCE SHOWS SEAS PUSHING NEAR 15 FT THE MIDDLE OF THE WEEK. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR WESTERN COLUMBIA RIVER GORGE. FREEZING RAIN ADVISORY UNTIL 4 PM PST TODAY FOR GREATER PORTLAND METRO AREA...LOWER COLUMBIA...NORTH OREGON COAST RANGE. WA...WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR WESTERN COLUMBIA RIVER GORGE. FREEZING RAIN ADVISORY UNTIL 4 PM PST TODAY FOR GREATER VANCOUVER AREA...WILLAPA HILLS...AND INTERSTATE 5 CORRIDOR IN COWLITZ COUNTY. PZ...SMALL CRAFT ADVISORY FOR WINDS FROM MIDNIGHT TONIGHT TO 4 PM PST MONDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM. $$ MORE WEATHER INFORMATION ONLINE AT.. HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV 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 MEDFORD OR
841 AM PST SUN FEB 9 2014 .DISCUSSION...CURRENT VISIBLE IMAGE THIS MORNING SHOWS SEVERAL BREAKS IN THE CLOUD COVER...ESPECIALLY EAST OF THE CASCADES. RADAR AND SURFACE OBSERVATIONS SUGGEST LITTLE IF ANY PRECIPITATION IS OCCURRING OVER THE REGION. SEXTON SUMMIT REPORTED LIGHT RAIN LAST HOUR, BUT NOTHING IN THE MOST RECENT REPORT. THE 12Z NAM AND LATEST RAP RUN SHOWS LITTLE OF ANY PRECIPITATION OVER OREGON, BUT INCREASING IN NORTHERN CALIFORNIA THIS AFTERNOON AS THE NEXT WAVE REACHES THE COAST. THUS HAVE ADJUSTED POPS DOWN FOR ALL AREAS THIS MORNING AND MAINLY OVER OREGON THIS AFTERNOON. IT`S GOING TO BE A FINE LINE FROM NEARLY NOTHING TO STEADY RAIN ALONG THE OREGON/CALIFORNIA BORDER THIS AFTERNOON AND TONIGHT. THE GFS AND NAM KEEP MOST OF THE SIGNIFICANT PRECIPITATION OVER NORTHERN CAL TONIGHT AND NOT MUCH ELSE ON OREGON. WE`LL LOOK AT THIS IN MORE DETAIL THIS MORNING. -PETRUCELLI && .AVIATION... && .MARINE... && .PREV DISCUSSION... /ISSUED 356 AM PST SUN FEB 9 2014/ SHORT TERM...TWO-DAY LIQUID PRECIPITATION AMOUNTS ACROSS THE CWA ENDING EARLY THIS MORNING RANGED FROM 2 TO 3 INCHES ALONG THE COAST AND COAST RANGES WITH 1 TO 2 INCHES OVER THE CASCADES AND FOOTHILLS AS WELL AS PORTIONS OF WESTERN SISKIYOU COUNTY. GENERALLY 0.50-1.00 INCH OF RAIN FELL OVER THE VALLEYS WEST OF THE CASCADES AND THE HIGHER TERRAIN EAST OF THE CASCADES...WHILE AMOUNTS LESS THAN 0.25 OF AN INCH WERE OBSERVED OVER MANY OF THE VALLEYS/BASINS OF THE EAST SIDE AND NORTHEAST CALIFORNIA. WHILE THIS WAS MUCH NEEDED PRECIPITATION, IT REALLY HASN`T PUT MUCH OF A DENT IN THE DEFICITS SEEN SO FAR THIS WINTER. WE`LL NEED SEVERAL MORE OF THESE EVENTS IN THE NEXT MONTH OR SO TO REALLY MAKE UP FOR LOST TIME. THE GOOD NEWS IS THAT ANOTHER WAVE WILL MOVE INTO THE AREA TODAY RESULTING IN SOME MORE RAIN FOR AREAS THAT BADLY NEED IT. WE`VE SEEN SNOW LEVELS RISE TO NEAR OR ABOVE 6000 FEET IN NORTHERN CALIFORNIA, BUT THEY`RE AROUND 5000-5500 FEET IN SW OREGON. IR SATELLITE IMAGERY IS SHOWING AN OMINOUS-LOOKING SHIELD OF MID- HIGH CLOUD MOVING ACROSS THE AREA EARLY THIS MORNING, BUT THE MAIN MOISTURE PLUME IS DIRECTED INTO NORTHERN CALIFORNIA AND THE VAST MAJORITY OF THE RAIN THIS TIME AROUND WILL FALL SOUTH OF THE OR/CA BORDER. RADAR IS ALREADY SHOWING SOME LIGHT RAIN SNEAKING NORTHWARD INTO SISKIYOU AND MODOC COUNTIES EARLY THIS MORNING. EXPECT THIS RAIN SHIELD TO EXPAND ACROSS NORCAL DURING THE REMAINDER OF THE MORNING AND PERSIST THROUGH THIS EVENING BEFORE TAPERING OFF OVERNIGHT INTO MONDAY MORNING. FARTHER NORTH, PRECIPITATION WILL BE MORE SHOWERY IN NATURE ACROSS SW OREGON AND DON`T EXPECT MUCH TO HIT THE RAIN GAUGES IN THE VALLEYS WITH A COUPLE OF HUNDREDTHS HERE AND THERE. THERE MAY BE A TENTH TO TWO- TENTHS IN THE COAST RANGES, SISKIYOUS AND CASCADES. BREAKS IN THE CLOUDS WEST OF THE CASCADES SHOULD RESULT IN ANOTHER MILD AFTERNOON WITH HIGHS IN THE UPPER 50S/LOW 60S. IT WILL BE COOLER WITH MORE CLOUD COVER AND RAIN EXPECTED IN NORTHERN CALIFORNIA. THE SURFACE WAVE WILL MOVE INLAND NEAR CAPE MENDOCINO THIS EVENING THEN MOVE INTO NEVADA BY MONDAY MORNING...EFFECTIVELY SHUTTING OFF THE FAUCET FOR A WHILE IN NORTHERN CALIFORNIA. WESTERLY FLOW WILL BRING ANOTHER FRONT TO THE COAST MONDAY, BUT IT WILL WEAKEN AS IT MOVES ONSHORE. THIS WILL LIKELY BRING ANOTHER ROUND OF SHOWERS FROM BROOKINGS NORTHWARD, BUT SHOWERS CHANCES DIMINISH FARTHER INLAND AND PROBABLY DO NOT GET MUCH PAST THE CASCADE CREST. A CHANCE OF SHOWERS LINGERS ACROSS NORTHWEST SECTIONS OF THE CWA MONDAY NIGHT. BY TUESDAY, SOUTHERLY FLOW WILL BE INCREASING AHEAD OF ANOTHER SERIES OF STORMS EXPECTED TO MOVE IN AT THE MIDDLE TO LATTER PART OF NEXT WEEK. MODELS HAVE SHOWN A TENDENCY TO SLOW DOWN THE FIRST SYSTEM, PREFERRING TO BRING IT ONSHORE TUESDAY NIGHT INTO WEDNESDAY. SO, HAVE MADE SOME ADJUSTMENTS HERE TO SLOW THINGS DOWN A BIT. SPILDE LONG TERM...WEDNESDAY THROUGH SATURDAY. MODELS CONTINUE TO SHOW AN ACTIVE PATTERN IN THE EXTENDED PERIOD, WITH AN UPPER LEVEL WESTERLY JET STREAM OVER THE REGION AS WELL AS AN UPPER LOW CENTERED IN THE GULF OF ALASKA. THIS PATTERN WILL ALLOW FRONTS TO MOVE INTO THE AREA THROUGH LATE NEXT WEEK. MODEL SOLUTIONS SHOW GOOD AGREEMENT WITH A COUPLE SHORTWAVE LOWS MOVING INTO THE AREA FROM THE WEST ON WEDNESDAY AND WEDNESDAY NIGHT. SNOW LEVELS ARE EXPECTED TO REMAIN HIGH FOR THIS EVENT, GENERALLY AT OR ABOVE 6000 FEET. THE FIRST OF THESE LOWS MOVES INLAND EARLY WEDNESDAY. THEN ANOTHER LOW APPROACHES THE COAST WEDNESDAY EVENING AND MOVES INLAND WEDNESDAY NIGHT. THE GFS IS STRONGER THAN THE ECMWF WITH THIS SECOND LOW WEDNESDAY NIGHT...AND GFS ENSEMBLES SHOW A WIDE SPREAD IN THE MSLP FIELD. SO HAVE GONE WITH A BLEND OF THE GFS ENSEMBLE AND ECMWF IN THE FORECAST. OVERALL EXPECT THESE SYSTEMS WEDNESDAY AND WEDNESDAY NIGHT TO BRING ADDITIONAL PRECIPITATION TO THE AREA WITH MODERATE TO LOCALLY HEAVY RAINFALL, ESPECIALLY FROM THE CASCADES WEST. EAST OF THE CASCADES, PRECIPITATION IS EXPECTED TO BE MORE LIGHT TO MODERATE. STRONG GUSTY WINDS ARE ALSO POSSIBLE WITH THESE SYSTEMS, ESPECIALLY WEDNESDAY MORNING WHEN MODELS SHOW A WESTERLY 700 MB JET OF 55 TO 75 KT MOVING OVER THE AREA. WEDNESDAY EVENING ANOTHER JET OF 50 TO 60 KT IS POSSIBLE. THIS PATTERN WILL LIKELY RESULT IN GUSTY WINDS OVER THE HIGHER TERRAIN AND INTO THE SUMMER LAKE AND SHASTA VALLEY AREAS. VARIABILITY IN MODEL SOLUTIONS INCREASES THURSDAY WITH THE GFS AND GFS ENSEMBLES SHOWING ANOTHER FRONT MOVING INTO THE AREA LATE THURSDAY FOLLOWED BY A SHORTWAVE RIDGE BUILDING INTO THE REGION FRIDAY. THE ECMWF IS QUICKER TO BUILD THE SHORTWAVE RIDGE INTO THE REGION THURSDAY NIGHT INTO FRIDAY AND BRINGS DRIER CONDITIONS INTO THE AREA BY FRIDAY. HAVE KEPT RELATIVELY HIGH POPS IN THE FORECAST FOR THURSDAY, LOWERING TO A CHANCE OF PRECIPITATION ON FRIDAY. THE SHORTWAVE RIDGE IS EXPECTED TO ONLY BRING A BRIEF DRYING TREND THOUGH. ON SATURDAY MODEL SOLUTIONS SHOW GOOD AGREEMENT WITH ANOTHER STRONG FRONT MOVING INLAND. SNOW LEVELS ARE EXPECTED TO BE HIGH DURING THE DAY SATURDAY, GENERALLY ABOVE 6000 FEET THEN LOWER BEHIND THE FRONT, POSSIBLY DOWN TO AROUND 4000 FEET. AS MODELS CONTINUE TO SHOW A UPPER LOW ANCHORED NEAR THE GULF OF ALASKA, EXPECT THE ACTIVE PATTERN TO CONTINUE BEYOND SATURDAY. /CC AVIATION...CONDITIONS AT THE TERMINALS ARE EXPECTED TO BE MVFR OR BETTER EARLY THIS MORNING, BUT WITH LOCAL IFR IS EXPECTED AT THE COAST, ESPECIALLY FROM GOLD BEACH SOUTH. A SYSTEM WILL MOVE THROUGH NORTHERN CALIFORNIA THIS MORNING SPREADING PRECIPITATION INTO SISKIYOU AND MODOC COUNTIES. SNOW LEVELS ARE QUITE HIGH SO IT WILL BE RAIN. THIS COULD REDUCE CONDITIONS TO IFR LATER THIS MORNING IN SOME AREAS WITH TERRAIN OBSCURATIONS LIKELY. MOST OF THE RAIN WILL STAY SOUTH OF OR/CA BORDER. -WRIGHT/SPILDE MARINE...ONLY A FEW LIGHT SHOWERS LINGER TODAY WITH WIND WAVE DOMINATED SEAS HAVING TRANSITIONED TO A FRESH SOUTHWEST SWELL. THIS SWELL IS MODERATE, HAS A SHORT PERIOD, AND WILL MIX WITH A SHORT PERIOD WEST SWELL TODAY THROUGH MONDAY. SOUTHERLY WINDS WILL ALSO REMAIN MODERATE SUNDAY THROUGH MONDAY. THE NEXT SIGNIFICANT FRONTAL SYSTEM IS EXPECTED TUESDAY INTO WEDNESDAY THEN ADDITIONAL FRONTS ARE POSSIBLE WEDNESDAY NIGHT INTO THE WEEKEND. -WRIGHT/SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PST THIS MORNING FOR PZZ350-356-370-376. $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1122 AM CST SUN FEB 9 2014 .AVIATION... /18Z TAFS/ The cold front has moved through KABI with north winds around 12 kts. Low clouds and fog to the north of this front have moved to within 20 nm of KABI but seemed to have stalled over the past half hour. With peak heating nigh, my gut says the clouds will generally remain north of KABI through mid-afternoon. I did include a tempo beginning at 20z for BKN004, however, just in case these clouds do slip a bit farther south. Once insolation begins to wane, this front will accelerate south, moving across the remainder of the area during the evening hours. These low clouds and fog will follow suit, with IFR (or worse) conditions anticipated areawide overnight through 18z Monday. I did include freezing drizzle at KABI, KSJT, and KBBD beginning late evening with visibilities of 3 miles or less. Accumulations are expected to be light, but present, nonetheless. Johnson && .PREV DISCUSSION... /ISSUED 848 AM CST SUN FEB 9 2014/ UPDATE... A quick forecast update was sent out to bring current temperatures back in line with recent trends. Temperatures remain near freezing along the I-10 corridor with a mixture of 30s and 40s across most of the remaining counties. However, the leading edge of a strong cold front has moved into the Big Country, dropping temperatures to near 30 degrees across Haskell, Throckmorton, and Shackelford Counties. We continue to receive reports of freezing fog across this area but as temperatures slowly warm, the potential for additional ice accumulations will decrease. Visibilities should slowly improve so no dense fog advisory will be issued. I also increased sky cover to account for the increase in high clouds. Max temps were left alone for now but I`ll continue to watch the progress of the cold front and adjust forecast temperatures as needed. Johnson PREV DISCUSSION... /ISSUED 600 AM CST SUN FEB 9 2014/ AVIATION... /12Z TAFS/ VFR conditions are expected today at the TAF sites. An initial cold front will sag south to KABI 17Z-18Z, resulting in a shift to northeast winds 5-10 KT. Any fog this morning and low cloud cover today are expected to remain north of Abilene. For the other TAF sites, winds today will be generally southwest at 6-12 KT. A reinforced cold front will push south across central and southern sections of West Central Texas tonight. The front should arrive at KSJT 02-03Z, and should reach the Interstate 10 corridor 07Z-08Z. Winds will shift to the northeast with the frontal passage. A degradation of conditions from VFR to IFR and possibly LIFR is expected, from north to south tonight. This will occur as low cloud cover expands to the south behind the front, with areas of drizzle and freezing drizzle developing. 19 PREV DISCUSSION... /ISSUED 459 AM CST SUN FEB 9 2014/ SHORT TERM... (Today and Tonight) A nearly stationary surface boundary extends from the eastern Texas Panhandle south to just northeast of Jayton, then east across Haskell and Throckmorton Counties. Temperatures are colder behind east/north of this boundary, where low cloudiness has filled in with areas of freezing fog. A strong cold front is moving south across Kansas. The NAM12 and RUC13 models appear to have the best handle on this boundary...and have it sagging south as a cold front to the Interstate 20 corridor by 11 AM to Noon, and then drifting a little farther south early this afternoon. Meanwhile, the aforementioned strong cold front will quickly move south today, entering the Big Country this afternoon and overtaking the lead boundary by late afternoon or evening. Carrying the inherited mention of fog early this morning across the area roughly north of a Rotan to Albany line, with freezing fog in the northern parts of Haskell and Throckmorton Counties where temperatures are at or just below freezing. With the marginally freezing temperatures and visibility with the fog to stay above one mile, not expecting any road ice problems this morning aross that area. Low cloud cover will be persistent through the day today across Haskell and Throckmorton counties. Temperature forecast today is tricky across the Big Country (area along/north of Interstate 20) with the initial frontal boundary. Made reductions across that area, where highs should be reached early this afternoon before temperatures level off and then slowly drop. Highs across that area are expected to range from the upper 30s/near 40 in Haskell and Throckmorton Counties, to the mid to upper 50s along Interstate 20 and 60s just south of I-20. Farther to the south, temperatures will be warm again today, with afternoon highs in the 70s to near 80 with mostly sunny skies. This evening and tonight, the reinforced cold front will push south through our central and southern counties, reaching the Interstate 10 corridor by 2 AM. Model boundary layer moisture fields indicate extensive low cloud cover developing south across West Central Texas behind the cold front, with areas of drizzle developing. With strong cold air advection, temperatures will drop to below freezing tonight across our northern and central counties, to the mid/upper 30s along and south of Interstate 10. With a weak overrunning pattern setting up and given the extent of boundary layer moistening, carrying areas of drizzle and freezing drizzle tonight until mid-morning Monday, with freezing drizzle mentioned where temperatures drop below freezing. 19 LONG TERM... (Monday night through Sunday) Winter precipitation possible Monday night and Tuesday... A cold surface ridge will be entrenched across the area Monday into Tuesday with temperatures remaining well below normal. An upper level trough will approach the area on Monday and move across the area on Tuesday. Still looks like the best chance for precipitation will be on Tuesday when lift from the upper trough will be greatest. Temperatures will be cold Monday and Tuesday with highs both days in the 30s across much of the area with the exception of far southern counties where some low to mid 40s are expected. Temperatures will fall into the 20s areawide Monday night. Made only minor changes to the forecast Monday night and Tuesday, mainly for precipitation type. Model forecast soundings continue to show a substantial warm layer aloft for much of this time period and a lack of moisture within the dendritic growth zone. This type of profile will favor a combination of freezing rain and sleet Monday night into Tuesday morning, with rain across southern sections and a winter mix across northern sections by Tuesday afternoon. Profiles due appear a bit more favorable for some snow to mix in mainly north of I-20 on Tuesday. At the present time, precipitation amounts are expected to be very light for this event, generally one tenth inch or less water equivalent with only minor snow and ice accumulations. Dry and warmer weather returns to the area Wednesday through Saturday with above normal temperatures through the period. The only mentionable feature will be a weak front on Saturday, with only slightly cooler temperatures into Sunday. 24 && .PRELIMINARY POINT TEMPS/POPS... Abilene 57 25 36 23 37 / 0 10 10 20 30 San Angelo 79 30 41 26 39 / 0 10 10 20 30 Junction 79 37 45 29 42 / 0 10 20 20 30 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 25
AREA FORECAST DISCUSSION
NWS SPOKANE WA
235 PM PST Sun Feb 9 2014 .SYNOPSIS... The Inland Northwest will see a break in the prolonged stretch of winter weather tonight however that will come to an end by Monday as a strong warm front moves into the area. The warm front will begin to scour the cold air out of the valleys but before another round of light to moderate snow is dumped across much of the region. More fronts will track the region during the week. Each will deliver periods of precipitation...however the valleys will finally change from snow to rain as temperatures climb above freezing for the first time this month. Meanwhile...significant snows are expected to fall over most of the mountains. && .DISCUSSION... Tonight...Weather scenario for tonight will be markedly quieter and drier than what we have experienced over the past several nights. The latest satellite pictures continue to show a broad plume of cloudiness covering most of the Inland Northwest save a small portion of extreme NE Washington and the northern Panhandle of Idaho. Meanwhile radar was only detecting a smattering of light precipitation echoes over the SE corner of Washington and NC Idaho. These echoes were the result of mid-level moisture and low- level isentropic ascent combining for very light snow. The radar echoes were finally reflecting what some of the model guidance was showing...unlike earlier today. Both the NAM and HRRR were showing this region of light precipitation persisting through mid-evening before being shunted to the south. QPF amounts from this activity should be very light with snowfall accumulations generally be an inch or less. In most cases much less. Meanwhile the focus for the later half of tonight will revolve around diffuse warm front currently sweeping through SW Washington. This band of precipitation will move into the northern Cascades before midnight as it travels to the northeast. Not sure how far the precipitation will cross over the Cascades as the isentropic ascent isn`t terribly strong. Nonetheless we will raise precipitation chances overnight for most of the Cascades and the Okanogan Valley/Highlands. Once again precipitation amounts will remain light. fx Monday through Tuesday night...A very active and progressively wet pattern will affect the region for the first part of the work week. Two systems will impact the Inland Northwest with little evidence of a break separating them. The first round of precipitation will start Monday as a warm front spreads light snow across the forecast area. Cold air will be in place at the surface but will eventually be overrun by warm air in the mid levels being pushed into the area on southerly flow. Initial light snow may change over to sleet or freezing rain in the lower basin Monday evening. This threat will spread north to the Wenatchee and Moses Lake area and Waterville Plateau overnight. Warm air will eventually make it to the surface across the southern valleys but p-type should remain snow for the valleys north of I-90. We could see advisory snowfall amounts accumulating for the east slopes of the Cascades and northeast zones. The moisture plume is not as impressive as earlier advertised with p-wats closer to normal for this first system so reaching winter highlight criteria in the valleys is not a slam dunk. There is not a true cold front with this system, but rather a wind shift to the west that may bring a brief respite to the basin. The second system follows right on the heels of the first and has a much more impressive tap into deep Pacific moisture. QPF potential will be in the 0.25 to 0.75 inches in the valleys with 1 to 2 inches or even higher amounts in the mountains. The Palouse will see most of this as rain. We will be watching local rivers carefully for possible ice breakup and resultant flooding. The warm front will push more warm air in from the south, changing precip over to rain for the southern third of the forecast area Tuesday. Snow levels will be on the rise and even the northernmost valleys could change over to rain by Tuesday night. The mountain zones will likely receive heavy snow from this extended event and the passes will be affected. Winter highlights will likely be needed for portions of the forecast area for this second system. Winds will strengthen and become gusty starting Tuesday afternoon and continuing through Wednesday. Warm air advection and gusty winds will aid in bringing temperatures back up to normal readings and possibly above by Tuesday night. /Kelch Wednesday: Models still agree on a progressive unsettled weather period through the remainder of the work week. Models are still differing a bit on the details. Looks like a surface low coupled with a wave riding along the westerly flow and a 120 kt upper level jet streak will be moving through the Inland Northwest Wednesday. Models do agree the heavier precipitation will fall during the morning hours and by afternoon the heavier precip will reside across the crest of the Cascade mountains and most of north ID. This surface low is moving in from the southwest and will therefore be ushering some slightly warmer temperatures. Warm enough that most valley locations will not cool to below freezing temps Wed morning...so the Wed event should be a rain event for a pretty widespread area. The exception to this would be the northern WA and ID valleys such as Omak, Republic, Colville and Sandpoint where they could see wet snow before changing over to rain sometime in the morning. The pressure gradient still looks packed together to create south to west winds...mainly for portions of the Columbia Basin, Palouse and Spokane/CDA areas. Wednesday night through Thursday: Strong westerly flow prevails which will keep showers in the forecast. There will be some dry periods across portions of the Basin north through the Okanogan Valley and Highlands because of downsloping off the Cascades. Otherwise mostly cloudy with temperatures around average for this time of the year. Southwest winds will remain elevated for the Palouse and into portions of Spokane County. Thursday night and Friday: We get an influx of moisture moving into the area as a broad ridge builds over the Pac NW and a trough moves towards southern Canada. The 12z EC as well as the 18Z GFS have slowed the timing down a bit, but it looks as though sometime Friday a front moves through. Currently models suggest some good upslope flow into the Cascade valleys and Basin ahead of the front Friday morning. Then by afternoon the Basin gets shadowed out as the precipitation is more confined to eastern WA and north ID...and the Cascade crest. Once again temps remain quite mild before the front passes and so most valley locations should see rain. Once again winds will be on the breezy side for portions of the Basin, Palouse and Spokane/CDA areas. /Nisbet Friday night through Sunday: A zonal flow pattern is expected to keep this period pretty active. With a wave of precip exiting late Friday, another wave is predicted to pass through the region Saturday afternoon bringing another round of precip. There is a slight warming trend with this pattern. Warmer temps could generate a rain/snow mix for the lower Columbia Basin and some of the valleys among the mountains if precip occurs during the day. Snow is expected for the region for precip during the evening hours. Winds will be breezy in the Palouse and Camas Prairie regions with gusts around the mid 20s MPH. /JDC && .AVIATION... 18Z TAFS: Very low confidence forecast as model guidance is quite poor with extremely variable conditions over short distances. Case in point the GEG-COE corridor. GEG was seeing light snow and LIFR cigs while not far away COE was seeing no snow and VFR cigs. In between SFF was seeing VFR conditions and light snow. Meanwhile BUFKIT data for GEG EAT and PUW was showing periods of snow through at least the first half of the forecast...while SFF and COE are only expected to see several hours of snow. Generally speaking the obs were not matching the guidance...not even close. Best we can do is track the weather to the shortwave trough currently over SC BC. This feature will pass most of the sites between 21-23z...and we will keep a mention of -SN or VCSH at least until it passes. Conditions will generally be MVFR by brief IFR is possible mainly at GEG. At MWH and EAT conditions will generally vary with cigs remaining between 025-050 ft. Hard to have much confidence in tonight`s forecast given the track record of the models in the short-term. Suspect stratus clouds will remain firmly entrenched over all sites through the night however PUW and LWS could see some improvement as winds turn increasingly offshore. The next round of precipitation will arrive just after 18z Mon...but could impact EAT a little earlier than that. fx && .PRELIMINARY POINT TEMPS/POPS... Spokane 18 29 27 36 33 38 / 20 70 50 70 80 80 Coeur d`Alene 19 31 28 36 32 38 / 30 80 60 80 90 80 Pullman 22 34 31 39 35 41 / 40 70 50 70 90 80 Lewiston 26 39 34 42 37 44 / 40 60 50 60 80 60 Colville 16 30 26 36 32 41 / 20 70 60 80 90 70 Sandpoint 18 30 27 35 32 38 / 30 80 80 80 100 90 Kellogg 20 31 29 35 32 37 / 80 80 80 80 100 90 Moses Lake 17 29 27 38 34 42 / 10 40 30 50 60 40 Wenatchee 20 29 26 38 32 39 / 10 60 40 50 60 40 Omak 18 30 22 35 30 39 / 20 60 40 60 60 40 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$