Re: March First Storm- In Like A Lion?
Posted: Fri Feb 26, 2010 7:16 am
Appears yet another Major Winter Storm to our E. Our threat locally would be from Coastal Flooding and some heavy rainfall (1-2 inch amounts). SPC mentions elevated T Storms, but nothing severe at this time...
PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
733 AM EST FRI FEB 26 2010
VALID 12Z TUE MAR 02 2010 - 12Z FRI MAR 05 2010
...WINTER CONTINUES WITH ANOTHER SNOW THREAT ACROSS THE INTERIOR
SOUTHEAST AND LOWER MID ALANTIC NEXT WEEK WITH AN ADDITIONAL
WIDESPREAD SNOW THREAT FROM THE SIERRAS INTO THE ROCKIES AND
REACHING THE CENTRAL PLAINS LATE NEXT WEEK...
MEDIUM RANGE GUIDANCE MAINTAINS A FAIRLY ENERGETIC PATTERN WITH
BUNDLES OF ERN PAC TROF ENERGY SEPARATING NEAR THE WEST COAST AS
THEY RUN INTO A PERSISTENT MEAN RIDGE OVER CANADA AND W-CNTRL
CONUS. THE LEADING SRN STREAM SYSTEM OF INTEREST IS FCST TO
TRAVEL FROM THE SRN PLAINS/WRN GULF COAST TO JUST OFF THE EAST
COAST IN THE MON-WED TIME FRAME. WHILE THERE IS SOME SPREAD WITH
THIS FEATURE... THE 00Z GFS AND GEFS MEAN ARE ON THE PROGRESSIVE
SIDE OF THE SPECTRUM WITH THE ECMWF/CMC/UKMET/NOGAPS AND 12Z ECMWF
ENSEMBLE MEAN ALL HOLDING THE SYSTEM CLOSER TO THE COAST BY LATE
DAY 5 WED. THIS SLOWER/WRN CLUSTER IS LIKELY BEST IN LIGHT OF THE
TENDENCY THIS SEASON FOR MODELS TO VERIFY TOO FAR SEWD SEVERAL
DAYS IN ADVANCE. ONE SIGNIFICANT WILD CARD IN THE EVOLUTION OF
THIS SYSTEM IS A BUNDLE OF ENERGY EXPECTED TO TRACK SEWD FROM THE
UPR MS VALLEY MON ONWARD. THUS FAR GUIDANCE HAS NOT BEEN
EXTREMELY AGREEABLE AMONG EACH OTHER AND COMPARED TO SUCCESSIVE
RUNS... BUT AT THE VERY LEAST THE LATEST ENSEMBLE GUIDANCE OFFERS
MORE SUPPORT FOR THE 00Z ECMWF WITH THIS FEATURE VERSUS THE
SLOW/DEEP OUTLIER SOLN OF THE 00Z GFS. MEANWHILE THE GFS/GEFS
MEAN MAY ALSO BE A LITTLE TOO FAST IN BRINGING THE NEXT ERN PAC
TROF TO THE WEST COAST DURING THE FIRST HALF OF NEXT WEEK. THE
GFS/ECMWF ACHIEVE SIMILAR TIMING BY DAY 6 THU THOUGH... AND BY DAY
7 FRI THERE IS MODERATE AGREEMENT UPON A WAVE REACHING THE SRN
PLAINS. FINALLY THE 00Z GFS IS ON THE SRN EDGE OF THE SOLN
ENVELOPE WITH THE CORE OF MID LVL ENERGY AND ASSOC SFC LOW NEARING
THE WEST COAST LATE NEXT WEEK BUT LATEST ENSEMBLE MEANS INDICATE
THE DAY 7 TROF ALOFT MAY BE A LITTLE MORE AMPLIFIED THAN THE 00Z
ECMWF. OVERALL BETTER COMPARISON TO THE FULL RANGE OF GUIDANCE
FAVORS USE OF A 50/50 BLEND OF THE 00Z ECMWFAND GFS AS THE
STARTING POINT FOR THE DAYS 3-7 FCST AN INCREASING PERCENTAGE OF
00Z ECMWF ENS MEAN CONCURRED BY USE OF GFS/EC LAGGED AVERAGE
FORECASTS.
THE SHORTWAVE WITH A STRONG NEG HT ANOMALY MOVING ACROSS TX AND
THE GULF COAST WILL INDUCE HVY RAINS ALONG THE GULF COAST MON AND
TUES AND EWD ACROSS FL INTO GA AND SC. DEEP TROF WITH WELL BELOW
NORMAL HTS/MID/LOW LEVEL TEMPS APPEAR LIKELY TO BRING SNOW ACROSS
THE NRN EDGE OF THE PCPN SHIELD ACROSS NRN AL/GA/SRN AND ERN TN.
AS THE TROF TAKES A MORE NEG TILTED ORIENTATION HEAVIER SNOW FALL
IS POSSIBLE ACROSS THE MTNS OF SC/NC/SWRN VA AND SRN WV. HVY
COASTAL RAINS AND ONSHORE GALE FORCE WINDS WITH HIGH SURF AND
BEACH EROSION/COASTAL FLOODING THREAT CAN BE EXPECTED TUES INTO
THURSDAY ALONG THE SOUTHEASTERN SEABOARD. AS THE MOVES UP EWD
ALONG THE COAST LOW DEEPENS LOWERING 1000-500 MB THICKNESS VALUES
AND H850 TEMPS IMPLY A SIG SNOW VERY POSSIBLY HVY SNOW THREAT FROM
THE NC MTNS AND FOOTHILLS INTO THE PIEDMONT AND NEWD INTO THE
LOWER VA PIEDMONT/TIDEWATER AREAS OF VA AND POSSIBLY LOWER SRN MD
AND LOWER DELMARVA. STRONG N-NE WINDS WILL EXTEND WELL FROM THE
MID ATLC REGION NWD ALONG THE NEW ENG COAST. DETAILS OF PCPN
TYPE/AMOUNTS AND COVERAGE WILL BECOME BETTER DEFINED AS THE EVENT
CLOSES TO WITHIN A 72 HR OR LESS TIMEFRAME.
WESTWARD...NEXT MID LEVEL COLD PAC TROF AND FRONT WILL COME INTO
THE PAC NORTHWEST AND
CA COAST TUES BRINGING MDT/HVY RAINS WITH SNOW AT HIGHER
ELEVATIONS. THE PCPN WILL EXTEND WELL INLAND BY WED AND THURS INTO
ROCKIES MAINLY AS SNOW FROM MT SWD TO NRN AZ AND NM. AS THIS
SHORTWAVE MOVES OUT INTO THE SRN HIGH PLAINS MID TO LATE WEEK
ADDITIONAL RAINFALL WILL BREAK OUT ACROSS THE SRN PLAINS WITH
INCREASING LOW LEVEL UPSLOPE GLFMEX INFLOW. A SIGNIFICANT SNOW
THREAT EWD FROM THE CO PLAINS INTO KS AND MO.
RAUSCH/ROSENSTEIN
PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
733 AM EST FRI FEB 26 2010
VALID 12Z TUE MAR 02 2010 - 12Z FRI MAR 05 2010
...WINTER CONTINUES WITH ANOTHER SNOW THREAT ACROSS THE INTERIOR
SOUTHEAST AND LOWER MID ALANTIC NEXT WEEK WITH AN ADDITIONAL
WIDESPREAD SNOW THREAT FROM THE SIERRAS INTO THE ROCKIES AND
REACHING THE CENTRAL PLAINS LATE NEXT WEEK...
MEDIUM RANGE GUIDANCE MAINTAINS A FAIRLY ENERGETIC PATTERN WITH
BUNDLES OF ERN PAC TROF ENERGY SEPARATING NEAR THE WEST COAST AS
THEY RUN INTO A PERSISTENT MEAN RIDGE OVER CANADA AND W-CNTRL
CONUS. THE LEADING SRN STREAM SYSTEM OF INTEREST IS FCST TO
TRAVEL FROM THE SRN PLAINS/WRN GULF COAST TO JUST OFF THE EAST
COAST IN THE MON-WED TIME FRAME. WHILE THERE IS SOME SPREAD WITH
THIS FEATURE... THE 00Z GFS AND GEFS MEAN ARE ON THE PROGRESSIVE
SIDE OF THE SPECTRUM WITH THE ECMWF/CMC/UKMET/NOGAPS AND 12Z ECMWF
ENSEMBLE MEAN ALL HOLDING THE SYSTEM CLOSER TO THE COAST BY LATE
DAY 5 WED. THIS SLOWER/WRN CLUSTER IS LIKELY BEST IN LIGHT OF THE
TENDENCY THIS SEASON FOR MODELS TO VERIFY TOO FAR SEWD SEVERAL
DAYS IN ADVANCE. ONE SIGNIFICANT WILD CARD IN THE EVOLUTION OF
THIS SYSTEM IS A BUNDLE OF ENERGY EXPECTED TO TRACK SEWD FROM THE
UPR MS VALLEY MON ONWARD. THUS FAR GUIDANCE HAS NOT BEEN
EXTREMELY AGREEABLE AMONG EACH OTHER AND COMPARED TO SUCCESSIVE
RUNS... BUT AT THE VERY LEAST THE LATEST ENSEMBLE GUIDANCE OFFERS
MORE SUPPORT FOR THE 00Z ECMWF WITH THIS FEATURE VERSUS THE
SLOW/DEEP OUTLIER SOLN OF THE 00Z GFS. MEANWHILE THE GFS/GEFS
MEAN MAY ALSO BE A LITTLE TOO FAST IN BRINGING THE NEXT ERN PAC
TROF TO THE WEST COAST DURING THE FIRST HALF OF NEXT WEEK. THE
GFS/ECMWF ACHIEVE SIMILAR TIMING BY DAY 6 THU THOUGH... AND BY DAY
7 FRI THERE IS MODERATE AGREEMENT UPON A WAVE REACHING THE SRN
PLAINS. FINALLY THE 00Z GFS IS ON THE SRN EDGE OF THE SOLN
ENVELOPE WITH THE CORE OF MID LVL ENERGY AND ASSOC SFC LOW NEARING
THE WEST COAST LATE NEXT WEEK BUT LATEST ENSEMBLE MEANS INDICATE
THE DAY 7 TROF ALOFT MAY BE A LITTLE MORE AMPLIFIED THAN THE 00Z
ECMWF. OVERALL BETTER COMPARISON TO THE FULL RANGE OF GUIDANCE
FAVORS USE OF A 50/50 BLEND OF THE 00Z ECMWFAND GFS AS THE
STARTING POINT FOR THE DAYS 3-7 FCST AN INCREASING PERCENTAGE OF
00Z ECMWF ENS MEAN CONCURRED BY USE OF GFS/EC LAGGED AVERAGE
FORECASTS.
THE SHORTWAVE WITH A STRONG NEG HT ANOMALY MOVING ACROSS TX AND
THE GULF COAST WILL INDUCE HVY RAINS ALONG THE GULF COAST MON AND
TUES AND EWD ACROSS FL INTO GA AND SC. DEEP TROF WITH WELL BELOW
NORMAL HTS/MID/LOW LEVEL TEMPS APPEAR LIKELY TO BRING SNOW ACROSS
THE NRN EDGE OF THE PCPN SHIELD ACROSS NRN AL/GA/SRN AND ERN TN.
AS THE TROF TAKES A MORE NEG TILTED ORIENTATION HEAVIER SNOW FALL
IS POSSIBLE ACROSS THE MTNS OF SC/NC/SWRN VA AND SRN WV. HVY
COASTAL RAINS AND ONSHORE GALE FORCE WINDS WITH HIGH SURF AND
BEACH EROSION/COASTAL FLOODING THREAT CAN BE EXPECTED TUES INTO
THURSDAY ALONG THE SOUTHEASTERN SEABOARD. AS THE MOVES UP EWD
ALONG THE COAST LOW DEEPENS LOWERING 1000-500 MB THICKNESS VALUES
AND H850 TEMPS IMPLY A SIG SNOW VERY POSSIBLY HVY SNOW THREAT FROM
THE NC MTNS AND FOOTHILLS INTO THE PIEDMONT AND NEWD INTO THE
LOWER VA PIEDMONT/TIDEWATER AREAS OF VA AND POSSIBLY LOWER SRN MD
AND LOWER DELMARVA. STRONG N-NE WINDS WILL EXTEND WELL FROM THE
MID ATLC REGION NWD ALONG THE NEW ENG COAST. DETAILS OF PCPN
TYPE/AMOUNTS AND COVERAGE WILL BECOME BETTER DEFINED AS THE EVENT
CLOSES TO WITHIN A 72 HR OR LESS TIMEFRAME.
WESTWARD...NEXT MID LEVEL COLD PAC TROF AND FRONT WILL COME INTO
THE PAC NORTHWEST AND
CA COAST TUES BRINGING MDT/HVY RAINS WITH SNOW AT HIGHER
ELEVATIONS. THE PCPN WILL EXTEND WELL INLAND BY WED AND THURS INTO
ROCKIES MAINLY AS SNOW FROM MT SWD TO NRN AZ AND NM. AS THIS
SHORTWAVE MOVES OUT INTO THE SRN HIGH PLAINS MID TO LATE WEEK
ADDITIONAL RAINFALL WILL BREAK OUT ACROSS THE SRN PLAINS WITH
INCREASING LOW LEVEL UPSLOPE GLFMEX INFLOW. A SIGNIFICANT SNOW
THREAT EWD FROM THE CO PLAINS INTO KS AND MO.
RAUSCH/ROSENSTEIN