389  
FXUS02 KWBC 031458  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
958 AM EST SAT MAR 03 2018  
 
VALID 12Z TUE MAR 06 2018 - 12Z SAT MAR 10 2018  
   
..ANOTHER NOR'EASTER TO AFFECT THE NORTHEAST WED-THU
 
 
   
..OVERVIEW AND WEATHER HIGHLIGHTS
 
 
A STORM SYSTEM IN THE OHIO VALLEY WILL REDEVELOP OFF THE  
MID-ATLANTIC COAST EARLY WEDNESDAY AND MOVE NORTHEASTWARD INTO THE  
GULF OF MAINE BY THURSDAY. THOUGH IT IS EXPECTED TO BE WEAKER THAN  
THE NOR'EASTER THAT AFFECTED THE NORTHEAST YESTERDAY, IT WILL  
STILL BRING A SWATH OF SNOW TO AT LEAST INTERIOR PORTIONS AND RAIN  
TO THE SOUTH FROM THE MID-ATLANTIC INTO THE SOUTHEAST. A SYSTEM  
OFF THE WEST COAST WILL SLOWLY WORK ITS WAY INTO THE PACIFIC  
NORTHWEST LATER IN THE WEEK, SPREADING MORE RAIN AND MOUNTAIN SNOW  
TO MUCH OF THE WEST COAST (FROM CENTRAL CALIFORNIA AND NORTHERN  
ARIZONA NORTHWARD) AND INTO THE INTERIOR BY THE START OF NEXT  
WEEKEND.  
   
..GUIDANCE ASSESSMENT/PREFERENCES
 
 
DETERMINISTIC CONSENSUS OFFERED A GOOD START FOR THE SFC AND  
TRIPLE POINT LOW MOVING OUT OF THE MIDWEST/OHIO VALLEY TUESDAY AND  
COASTAL REDEVELOPMENT WEDNESDAY. THEREAFTER, ECMWF REMAINED WEAKER  
AND FARTHER EAST WITH THE COASTAL SFC LOW (AS IT MAINTAINED A  
DEEPER PARENT LOW OVER LAKE HURON) THAN ALL OTHER MODELS AND  
ENSEMBLE MEANS (INCLUDING ITS OWN) AND WAS DROPPED FROM THE  
PREFERENCE. 06Z GFS/00Z CANADIAN AND 06Z GEFS/00Z ECMWF ENSEMBLE  
MEANS WERE CLUSTERED IN THE GULF OF MAINE BY 12Z THU (00Z  
GFS/UKMET JUST TO THE NORTHWEST ALONG THE COAST). SYSTEM WILL  
DEPART THE REGION FRIDAY THOUGH THE TREND HAS BEEN SLOWER OWING TO  
MUCH STRONGER DOWNSTREAM RIDGING NOSING IN FROM THE NW ATLANTIC  
INTO LABRADOR/NUNATSIAVUT.  
 
OFF THE WEST COAST, MODELS/ENSEMBLES WERE STILL STRUGGLING WITH  
THE EVOLUTION OF THE FLOW IN THE EASTERN/NORTHEASTERN PACIFIC  
(SOURCE REGION OVER ALASKA) WITH THE LEAD POSITIVELY TILTED TROUGH  
AND SUBSEQUENT SHORTWAVE DIVING INTO ITS WESTERN SIDE ON THURSDAY.  
GIVEN A MORE AMPLIFIED DOWNSTREAM PATTERN OVER THE NORTHEASTERN  
CONUS AND SE CANADA, FELT THE LATEST 00Z ENSEMBLES (06Z GEFS) HAD  
A BETTER HANDLE ON THE FLOW (ALL THINGS CONSIDERED) INTO NEXT  
WEEKEND THAN EARLIER RUNS. SYSTEM SHOULD MOVE INTO THE PAC NW  
AROUND FRIDAY AND WEAKEN AS IT MOVES EASTWARD NEXT SATURDAY.  
TRENDED TOWARD THE ECMWF ENSEMBLE MEAN AND GFS/GEFS MEAN FOR THE  
END OF THE PERIOD WHICH FIT WELL WITH THE EASTERN CONUS EVOLUTION  
AS WELL.  
 
FRACASSO  
 

 
 
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