648  
FXUS02 KWBC 160701  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
200 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
 
 
THE WPC MEDIUM RANGE PRODUCT SUITE WAS MAINLY DERIVED FROM A MODEL  
AND ENSEMBLE COMPOSITE DAYS 3-7.  
 
   
..WEATHER HIGHLIGHTS/HAZARDS
 
 
AN ORGANIZED LOW PRESSURE SYSTEM WILL 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. 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 WITH  
POTENTIAL FOCUS DUE TO AMPLE RUN TO RUN TROUGH TRACK/SEPARATION  
UNCERTAINTY ALOFT. 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/00 UTC CANADIAN MODELS,  
ARE MORE ROBUST WITH FRONTAL WAVE/COASTAL LOW/STORM GENESIS AND  
MID-WINTER PRECIPITATION EXTENT ACROSS THE REGION AND THE EAST  
COAST AT THESE LONGER TIME PERIODS. 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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