HPC Discussion - ...MAJOR WINTER STORM ANTICIPATED
Posted by
JAC on 2/3/2010, 7:07 am
EXTENDED FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 236 PM EST MON FEB 01 2010 VALID 12Z THU FEB 04 2010 - 12Z MON FEB 08 2010
...MAJOR WINTER STORM ANTICIPATED FROM THE CAROLINAS TO SOUTHEASTERN NEW ENGLAND...
PRELIMINARY UPDATE...
THE 00Z/01 GLOBAL NUMERICAL GUIDANCE SHOWS A CONTINUATION OF THE CURRENT FLOW REGIME ACROSS THE UNITED STATES THROUGH THE MEDIUM RANGE PERIOD...WITH A STRONG PACIFIC JET COMING INTO THE WEST COAST...AND A SPLIT...CONFLUENT FLOW OVER THE EASTERN STATES. THIS PATTERN PRODUCED SNOW AND ICE OVER PORTIONS OF THE CAROLINAS AND MID ATLANTIC STATES THIS PAST WEEKEND...AND IT APPEARS ANOTHER WINTER STORM IS IN THE OFFING FOR THE SAME AREAS THIS UPCOMING WEEKEND...WITH AN EXPANSION OF THE SNOW INTO THE NORTHEAST ON THE OCEAN SIDE OF I-95. A COMPLEX WAVE ORGANIZING OVER THE GULF OF MEXICO EARLY IN THE PERIOD WILL SPREAD MAINLY RAIN INTO THE SOUTHERN STATES. THE WAVE IS EXPECTED TO CONSOLIDATE ALONG THE CAROLINA COAST EARLY DAY 5...WITH A RAPID DEEPENING NEAR CAPE HATTERAS. CLIMATOLOGY SUGGESTS THE STORM WILL LIFT ALONG THE WESTERN EDGE OF THE GULF STREAM...THOUGH THE DOMINANT NORTHERN STREAM THIS WINTER IS LIKELY TO HERD THE BEST MOISTURE EAST OF I-95...AS WITH THE EVENT BEFORE CHRISTMAS. STILL...THE IMPACT FOR THE MAJOR METROPOLITAN AREAS WOULD BE HIGH. A MEAN RIDGE OVER THE ROCKIES WILL MARK THE CUTOFF FOR THE EASTWARD PROGRESSION OF PACIFIC MOISTURE...WITH MOST OF THE PRECIPITATION WRUNG OUT ALONG AND WEST OF THE CASCADES AND SIERRA NEVADA. THE 00Z/01 GFS...GEFS MEAN...ECMWF...AND EC MEAN ALL CLUSTER FAIRLY WELL ACROSS THE NATION THROUGH THE PERIOD...BUT WITH ITS STRONG VERIFICATION THIS SEASON...STUCK CLOSEST TO THE DETERMINISTIC ECMWF FOR THE DETAILS OF THE PRELIMINARY UPDATE PACKAGE.
FINAL...
THE 12Z/01 DETERMINISTIC GFS WAS AN OUTLIER TO ITS ENSEMBLE MEAN...AS WELL AS THE NEW GEM GLOBAL...UKMET...AND ECMWF...WITH THE SUPPRESSED TRACK OF THE CYCLONE ALONG THE EAST COAST DAY 5. THE ECMWF...UKMET...AND PARTICULARLY THE GEM GLOBAL CRANK UP A REAL STEMWINDER BETWEEN HATTERAS AND THE LOWER DELMARVA PENINSULA SATURDAY...WITH INDICATIONS THAT THE MID LEVEL LOW WILL CLOSE OFF FOR A TIME...PROLONGING THE HEAVY PRECIPITATION AND HIGH WINDS. THE NORTHERN EDGE OF THE GUIDANCE BRINGS PRECIPITATION AS FAR NORTH AS BOSTON...AND EXPECT THAT WITH A GRADUAL TREND OF THE LOW TRACK CLOSER TO THE WESTERN EDGE OF THE GULF STREAM...THAT THE STORM WILL END UP AFFECTING THE USUAL SUSPECTS ALONG AND EAST OF THE I-95 CORRIDOR. THIS WINTER HAS HAD SO MUCH BLOCKING...THAT THE DEEP INTERIOR OF THE NORTHEAST HAS BEEN LEFT OUT OF MUCH OF THE HEAVY SNOW. AT THIS POINT...DO NOT SEE WHY THAT SHOULD NOT BE THE CASE WITH THIS EVENT AS WELL. THE ONLY CHANGES MADE FOR THE FINAL ISSUANCE AFFECT THE EAST...WITH A SLIGHT ADJUSTMENT OF THE CYCLONIC CIRCULATION NORTHWARD TOWARD CLIMATOLOGY. STILL PUT FAITH IN THE ECMWF FOR THE WESTERN STATES.
CISCO
VALID 12Z WED FEB 03 2010 - 00Z FRI FEB 05 2010 BEFORE POTENTIALLY IMPACTING THE SOUTHEAST AND MID ATLANTIC STATES LATER THIS WEEK WITH A COMBINATION OF HEAVY RAIN...SNOW AND ICE... A VIGOROUS UPPER LEVEL SYSTEM WILL FIRST SPREAD WIDESPREAD PRECIPITATION ACROSS THE SOUTHERN TIER STATES FROM THE DESERT SOUTHWEST TO THE CENTRAL GULF COAST OVER THE NEXT COUPLE OF DAYS. MODERATE TO HEAVY RAINS ARE LIKELY TODAY ACROSS PORTIONS OF SOUTH TEXAS...PARTICULARLY ALONG THE LOWER RIO GRANDE VALLEY AND LOWER TEXAS COAST AS STRENGTHENING SOUTHEASTERLY WINDS BEGIN TO DRAW A DEEP POOL OF MOISTURE OUT OF THE WESTERN GULF INTO THE REGION. GENERALLY LIGHTER PRECIPITATION IS EXPECTED ACROSS THE REMAINDER OF THE STATE...AS WELL AS ACROSS OKLAHOMA INTO THE SOUTHWEST AS THIS MOISTURE IS DRAWN WESTWARD AROUND A STRONG CYCLONE CENTERED OVER NORTHERN MEXICO. THIS PRECIPITATION SHOULD INCLUDE SOME LIGHT TO MODERATE SNOWS ACROSS THE TEXAS AND OKLAHOMA PANHANDLES AND SOUTHERN ROCKIES TODAY. MODERATE TO HEAVY RAINS ARE EXPECTED TO ADVANCE EASTWARD ACROSS THE CENTRAL GULF COAST STATES TOMORROW AS A SURFACE LOW IN RESPONSE TO THE ADVANCING UPPER SYSTEM BECOMES BETTER ORGANIZED AND BEGINS ITS TRACK ACROSS THE NORTHWESTERN GULF. MEANWHILE...LIGHT PRECIPITATION WILL EXTEND FURTHER TO THE NORTH THROUGH THE PLAINS STATES AS A MORE NORTHERLY UPPER LEVEL SYSTEM MOVING ACROSS THE NORTHWESTERN U.S. WORKS TO DRAW THE DEEPER MOISTURE FURTHER TO THE NORTH THROUGH THE REGION.
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In this thread:
Possible Significant Storm Friday - IN to VA to FL -
JAC,
2/2/2010, 3:59 pm- Winter Storm Warning up for DC - near Blizzard Conditions - JAC, 2/4/2010, 10:31 am
- Re: Possible Significant Storm Friday - IN to VA to FL - nyjames11955, 2/4/2010, 8:23 am
- Could be Major Blizzard for Delmarva & NJ - JAC, 2/4/2010, 6:18 am
- Deep Moisture Convergence starting up in NW GOM - JAC, 2/4/2010, 5:46 am
- FL dodges severe-weather - JAC, 2/4/2010, 5:40 am
- Winter-Storm Watches going up - JAC, 2/3/2010, 3:40 pm
- Re: Possible Significant Storm Friday - IN to VA to FL - Fred, 2/3/2010, 3:10 pm
- GFS pushing genesis way west to NW GOM - JAC, 2/3/2010, 2:04 pm
- Re: Possible Significant Storm Friday - IN to VA to FL - Fred, 2/3/2010, 9:47 am
- HPC Discussion - ...MAJOR WINTER STORM ANTICIPATED - JAC, 2/3/2010, 7:07 am
- Heaviest Snow just west of DC - JAC, 2/3/2010, 6:49 am
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