701  
FXUS02 KWBC 140700  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
159 AM EST FRI JAN 14 2022  
 
VALID 12Z MON JAN 17 2022 - 12Z FRI JAN 21 2022  
 
...MAJOR WINTER STORM TO LIFT OVER THE NORTHERN MID-ATLANTIC/LOWER  
GREAT LAKES AND NORTHEAST MONDAY...  
 
   
..GUIDANCE/PREDICTABILITY ASSESSMENT
 
 
MODELS AND ENSEMBLES HAVE COME INTO CLOSER AGREEMENT IN THE DAY  
3-5 (MON-WED) INCLUDING A MAJOR WINTER STORM TO BOLSTER FORECAST  
CONFIDENCE. THE WPC PRODUCT SUITE THIS PERIOD WAS MAINLY DERIVED  
FROM A GFS/ECMWF/UKMET/CANADIAN COMPOSITE ALONG WITH THE 01 UTC  
NATIONAL BLEND OF MODELS. WPC CONTINUITY IS WELL MAINTAINED.  
 
PREDICTABILTY SEEMS MARGINALLY ABOVE NORMAL INTO DAYS 6/7  
(THU-NEXT FRI), BUT FORECAST SPREAD DOES INCREASE IN PARTICULAR  
WITH THE HANDLING OF PACIFIC SYSTEM ENERGIES INTO AN UPPER RIDGE  
BUILT OFF THE WEST COAST. RECENT ECMWF/UKMET RUNS BRING MORE UPPER  
TROUGHING THROUGH THIS RIDGE INTO THE NORTHWEST THAN THE CANADIAN  
AND ESPECIALLY THE GFS THAT DEFLECT ENERGIES MORE OVER THE RIDGE.  
SUSPECT RIDGE AMPLITUDE SHOULD HOLD ON THE MORE AMPLIFIED SIDE OF  
THE FULL ENVELOPE OF SOLUTIONS GIVEN INITIAL STRENGTH, PERHAPS  
CLOSEST TO THE 06 UTC GEFS MEAN.  
 
   
..WEATHER HIGHLIGHTS/HAZARDS
 
 
A MAJOR WINTER LOW DEVELOPING OVER THE WEEKEND SEEMS SET TO LIFT  
FROM THE NORTHERN MID-ATLANTIC/LOWER GREAT LAKES THROUGH THE  
NORTHEAST MONDAY. THIS WILL PRESENT A CONTINUING FULL ARRAY OF  
WEATHER HAZARDS AND THREATS. HEAVY WRAPPING SNOWS WILL SPREAD IN  
EARNEST ALONG/ON THE BACKSIDE OF THE DEEPENING LOW AND WEST OF THE  
I-95 CORRIDOR INTO INTERIOR AREAS GIVEN TRACK. FOR LOCATIONS  
EAST/ALONG I-95 (INCLUDING THE MAJOR METRO AREAS), PRECIPITATION  
MAY START OUT AS ACCUMULATING SNOW, WITH A CHANGEOVER TO SLEET  
THEN RAIN AS WARMER AIR FILTERS IN FROM THE EAST. GUSTY WINDS  
SURROUNDING THE SURFACE LOW MAY CREATE HIGH WAVES OFF THE COAST  
LEADING TO POSSIBLE COASTAL FLOOD CONCERNS ALONG THE NORTHEAST  
COASTLINE.  
 
AFTER THE MAIN LOW EXITS NORTHEAST OF THE U.S. BY TUESDAY, ANOTHER  
LOW PRESSURE SYSTEM IS FORECAST TO TRACK OVER THE NORTH-CENTRAL  
U.S. IN RESPONSE TO A MID-UPPER SHORTWAVE AND BRING SOME SNOW TO  
THE UPPER MIDWEST AND GREAT LAKES THEN NORTHERN NEW ENGLAND, WITH  
POSSIBLY HIGHER TOTALS NEAR TYPICAL LAKE ENHANCEMENT AREAS. THE  
WEST COULD SEE SOME LIGHT PRECIPITATION DURING THE PERIOD,  
PARTICULARLY OVER THE PACIFIC NORTHWEST AND INTO THE NORTHERN  
ROCKIES, WITH MAINLY DRY CONDITIONS ELSEWHERE. RAIN MAY DEVELOP  
ACROSS THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST FOR MID-LATER  
NEXT WEEK WITH MODEST RETURN GULF FLOW WITH INDUCED WAVE PASSAGES.  
 
SCHICHTEL  
 
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC  
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION, WINTER WEATHER OUTLOOK PROBABILITIES  
AND HEAT INDICES ARE 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  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML  
 

 
 

 
 
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