411  
FXUS02 KWBC 161858  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
158 PM EST SUN JAN 16 2022  
 
VALID 12Z WED JAN 19 2022 - 12Z SUN JAN 23 2022  
 
...COOLED SOUTH TO EAST COAST SNOW/ICE THREAT WITH FRONTAL/COASTAL  
LOW GENESIS LATE WEEK...  
   
..PATTERN OVERVIEW
 
 
A SERIES OF IMPULSES WILL CARVE OUT AND REINFORCE A BROAD MEAN  
TROUGH OVER THE CENTRAL AND EASTERN STATES DURING THE EXTENDED  
PERIOD WHILE THE UPPER RIDGE AMPLIFIES OFFSHORE THE WEST COAST.  
THE LEADING SHORTWAVE WILL TRACK OVER THE GREAT LAKES REGION INTO  
THE NORTHEAST BY THURSDAY WITH ONE BEHIND IT DIGGING INTO THE  
SOUTH FRIDAY AND THEN PULLING OFFSHORE THE MID-ATLANTIC/SOUTHEAST  
REGION SATURDAY. THIS PATTERN WILL BE CONDUCIVE FOR PRECIPITATION  
TO SPREAD ACROSS THE HIGHER TERRAIN OF THE NORTHERN AND CENTRAL  
ROCKIES THROUGH FRIDAY AND PRECIPITATION TO SPAN FROM  
TEXAS/WESTERN GULF COAST, DEEP SOUTH, SOUTHEAST TO THE  
MID-ATLANTIC AND PUSH EASTWARD BEYOND THE WEEKEND INTO NEXT EARLY  
NEXT WEEK.  
 
...GUIDANCE/PREDICTABILITY ASSESSMENT AND WEATHER  
HIGHLIGHTS/HAZARDS...  
 
PREVIOUSLY, IT WAS NOTED THAT 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.  
THE 06Z/12Z GUIDANCE CONTINUES TO HAVE NOTABLE SPREAD ON THE  
PLACEMENT/TRACK OF THE SECONDARY SHORTWAVE FEATURE. IN TURN, THE  
QPF PLACEMENT VARIES SIGNIFICANTLY AS WELL, ESPECIALLY ACROSS THE  
GULF STATES, SOUTHEAST AND SOUTHERN APPALACHIA. TO COMBAT THESE  
DIFFERENCES, A GENERAL BLEND OF THE GFS/GEFS MEAN/CMC/ECWMF/EC  
ENSEMBLE MEANS WERE USED THROUGH ALL TIME PERIODS. THIS PROVIDE A  
MIDDLE GROUND APPROACH AND HELPED MAINTAIN CONTINUITY FROM THE  
PREVIOUS FORECAST CYCLE.  
 
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 THROUGH THURSDAY. 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. AS THE ARCTIC  
BLAST REACHES THE SOUTHERN TIER STATES A WAVY COLD FRONT WILL  
ENCOUNTER GULF MOISTURE TO FUEL AN EMERGING AREA OF PRECIPITATION  
UP FROM THE SOUTH/SOUTHEAST. THIS PATTERN WILL BE FAVORABLE FOR AN  
ENHANCED SWATH OF OVERRUNNING SNOW/ICE ON THE NORTHERN PERIPHERY  
OF ACTIVITY LATER IN THE WEEK. THIS WAVE MAY DEVELOP INTO A ROBUST  
COASTAL LOW/WINTER STORM THAT TRACKS UP THE EAST COAST.  
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.  
 
CAMPBELL/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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