240  
FXUS02 KWBC 160711  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
210 AM EST SUN JAN 16 2022  
 
VALID 12Z WED JAN 19 2022 - 12Z SUN JAN 23 2022  
   
..PATTERN OVERVIEW
 
 
A MEAN UPPER RIDGE WILL AMPLIFY ALONG/OFF THE WEST COAST BY  
MID-LATER WEEK. THIS WILL ALLOW A SERIES OF NORTHERN STREAM  
IMPULSES CARVE OUT AND REINFORCE A LARGE MEAN TROUGH DOWNSTREAM  
OVER THE CENTRAL TO EASTERN U.S. LATER WEEK INTO THE WEEKEND. OF  
THE MAIN SHORTWAVES, THE FIRST SHOULD SLIDE OVER THE GREAT LAKES  
INTO THE NORTHEAST WEDNESDAY AND THURSDAY, WITH THE NEXT TENDING  
TO DIG MORE SHARPLY INTO THE SOUTH FRIDAY AND UP OFF THE  
MID-ATLANTIC/SOUTHEAST COAST SATURDAY. THERE IS SIGNIFICANT  
FORECAST SPREAD AND RUN TO RUN UNCERTAINTY WITH THIS LATTER  
FEATURE AND ASSOCIATED MID-WINTER WEATHER FOCUS WITH FRONTAL  
WAVE/COASTAL LOW GENESIS.  
 
...GUIDANCE/PREDICTABILITY ASSESSMENT AND WEATHER  
HIGHLIGHTS/HAZARDS...  
 
THE WPC MEDIUM RANGE PRODUCT SUITE WAS MAINLY DERIVED FROM A MODEL  
AND ENSEMBLE COMPOSITE DAYS 3-7. THERE IS GOOD AGREEMENT WITH AN  
ORGANIZED LOW PRESSURE SYSTEM SET TO DIG INTO THE NORTH-CENTRAL  
U.S. AND SUBSEQUENTLY TRACK MOVING EASTWARD ALONG THE  
U.S./CANADIAN BORDER WED/THU. THIS SHOULD BRING SOME SNOW TO THE  
GREAT LAKES THEN NORTHERN NEW ENGLAND, WITH LOCALLY HIGHER TOTALS  
EXPECTED NEAR TYPICAL LAKE ENHANCEMENT AREAS AS COLD HIGH PRESSURE  
SWEEPS DOWN ACROSS THE CENTRAL AND EASTERN U.S. IN THE WAKE OF THE  
LOW IN A PATTERN WITH ABOVE NORMAL PREDICTABILITY FOR THESE  
FEATURES. THE WAVY TRAILING COLD FRONT ON THE LEADING EDGE OF THIS  
ARCTIC BLAST WILL GAIN SOME GULF MOISTURE TO FUEL AN EMERGING AREA  
OF PRECIPITATION UP FROM THE SOUTH/SOUTHEAST. GUIDANCE VARIES  
HOWEVER WITH POTENTIAL FOCUS DUE TO AMPLE RUN TO RUN TROUGH  
TRACK/SEPARATION UNCERTAINTY ALOFT LATER WEEK INTO THE WEEKEND.  
THE PATTERN OFFERS POTENTIAL INTO LATER WEEK FOR AN ENHANCED SWATH  
OF OVERRUNNING SNOW/ICE ON THE NORTHERN PERIPHERY OF ACTIVITY. A  
CLUSTER OF MULTI-MODEL ENSEMBLE MEMBERS ALONG WITH IN PARTICULAR  
THE 18 UTC GFS AND NOW THE LATEST 00 UTC ECMWF/CANADIAN MODELS,  
ARE MUCH MORE ROBUST WITH FRONTAL WAVE TO COASTAL LOW/STORM  
GENESIS AND MID-WINTER PRECIPITATION EXTENT ACROSS THE REGION AND  
UP THE EAST COAST AT THESE LONGER TIME PERIODS. HOWEVER, THE 00  
UTC GFS HAS BACKED OFF. THE PREFERRED MODEL AND COMPOSITE TRENDS  
WPC PRODUCT CONTINUITY TOWARD MORE ORGANIZED AND CLOSER TO THE  
COAST GENESIS AND TRACK, BUT NOW AT THIS POINT AS STRONG AS SOME  
OF THE MODELS. MEANWHILE, THE WEST COULD SEE SOME LIGHT  
PRECIPITATION THROUGH THE PERIOD, PARTICULARLY OVER THE PACIFIC  
NORTHWEST AND INTO THE NORTHERN ROCKIES AS WEAKENING SYSTEMS CROSS  
THE REGION, WITH MAINLY DRY CONDITIONS ELSEWHERE.  
 
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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