611  
FXUS02 KWBC 030651  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
150 AM EST SUN FEB 03 2019  
 
VALID 12Z WED FEB 06 2019 - 12Z SUN FEB 10 2019  
   
..OVERVIEW
 
 
POSITIVE HEIGHT ANOMALY NEAR THE GULF OF ALASKA WILL FAVOR WESTERN  
CONUS TROUGHING WED-SUN AND BROAD SW UPPER FLOW IN THE EASTERN  
STATES. SUBTROPICAL UPPER HIGH WILL DRIFT OUT OF THE BAY OF  
CAMPECHE AND INTO THE FLORIDA STRAITS WHICH WILL LARGELY KEEP THE  
STORM TRACK THROUGH THE GREAT LAKES AND ST. LAWRENCE VALLEY.  
 
   
..GUIDANCE/PREDICTABILITY ASSESSMENT AND PREFERENCES
 
 
UPSTREAM PACIFIC FLOW AND NORTHERN/SOUTHERN STREAM SEPARATION IN  
THE WEST CONTINUED TO BE POORLY RESOLVED BY THE MODELS/ENSEMBLES  
WITH NOTICEABLE RUN-TO-RUN CHANGES. THE ECMWF AND ITS ENSEMBLES  
HAVE BEEN QUITE DIFFERENT THAN THE GFS AND ITS ENSEMBLES WHILE THE  
CANADIAN AND ITS ENSEMBLES MOSTLY CLUSTERED NEAR THE ECMWF  
ENSEMBLES. PREFERRED THE CLUSTER NEAR THE ECMWF ENSEMBLE MEAN  
WHICH SHOWED A BIT QUICKER EXIT OF THE TROUGH OUT OF THE ROCKIES  
LATE WED/EARLY THU AND NO SUBSEQUENT SURFACE LOW DEVELOPMENT OUT  
OF THE LOWER MS VALLEY NEXT FRI/SAT. THIS MAINTAINED GOOD  
CONTINUITY FROM THE PREVIOUS SHIFT.  
 
WEATHER HIGHLIGHTS/HAZARDS...  
 
ABOVE AVERAGE TEMPERATURES IN THE SOUTHEAST/EAST (WITH RECORD  
HIGHS POSSIBLE) WILL BE REPLACED BY NEARER TO AVERAGE TEMPERATURES  
AS THE COLD FRONT CLEARS THE EAST COAST, BUT NOT THROUGH FLORIDA  
THANKS TO THE STRONG UPPER RIDGE. IN THE NORTHERN TIER FROM MT TO  
THE UPPER MIDWEST, TEMPERATURES WILL REMAIN WELL BELOW AVERAGE  
BEHIND AN ARCTIC FRONT THAT WILL GET HUNG UP NEAR THE DIVIDE (BUT  
STILL BRING COLD AIR TO THE PACIFIC NORTHWEST VIA NORTHERN STREAM  
HEIGHT FALLS).  
 
STORM TRACK WILL FAVOR SNOW AND LOWER ELEVATION RAIN EXITING THE  
ROCKIES WED AND SPREADING ACROSS THE PLAINS TO THE OHIO VALLEY (AS  
A SECOND WAVE OF PRECIPITATION) THURSDAY WITH INCREASED SNOW  
AROUND THE NORTH/NORTHWEST SIDE OF THE DEVELOPING SURFACE LOW.  
WARM-SECTOR RAIN MAY BE LOCALLY MODEST THROUGH THE LOWER MS  
VALLEY/ARKLATEX BUT TREND LIGHTER TO THE EAST AS THE UPPER RIDGING  
KEEPS THE BEST DYNAMICS WELL TO THE NORTH. WITH THE FAVORED TRACK  
THROUGH LAKE ONTARIO, RAIN WILL SPREAD THROUGH THE MID-ATLANTIC  
INTO THE NORTHEAST EXCEPT INTERIOR MAINE AND NORTHERN NH/VT/NY.  
ONCE THE LOW PULLS AWAY, LAKE-EFFECT SNOW WILL RESUME FOR AT LEAST  
FRIDAY INTO SATURDAY AS THE SFC HIGH SLIPS SOUTHEASTWARD.  
 
FRACASSO  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION AND WINTER WEATHER OUTLOOK  
PROBABILITIES ARE FOUND AT:  
 
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page