455  
FXUS02 KWBC 160656  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
255 AM EDT SAT APR 16 2022  
 
VALID 12Z TUE APR 19 2022 - 12Z SAT APR 23 2022  
   
..WEATHER PATTERN OVERVIEW
 
 
THERE WILL BE THREE WELL-DEFINED STORM SYSTEMS THAT WILL AFFECT  
THE CONTINENTAL U.S. NEXT WEEK. THE FIRST WILL BE A COASTAL LOW  
NEAR THE NORTHEAST U.S. COAST ON TUESDAY THAT WILL INTENSIFY AS IT  
LIFTS NORTHWARD TOWARDS EASTERN QUEBEC, BRINGING RAIN, WIND, AND  
MOUNTAIN SNOW TO NEW ENGLAND. A LARGE SURFACE HIGH WILL THEN  
ENCOMPASS THE EASTERN HALF OF THE NATION THROUGH WEDNESDAY AHEAD  
OF THE NEXT DEVELOPING STORM SYSTEM OVER THE PLAINS, WHICH SHOULD  
RESULT IN ANOTHER COLD FRONT REACHING THE EAST COAST BY FRIDAY.  
THE THIRD SYSTEM DEVELOPS OVER THE WEST COAST AND INTERMOUNTAIN  
WEST REGION FOR THE END OF THE WEEK AS AN AMPLIFIED UPPER LEVEL  
TROUGH BUILDS IN FROM THE PACIFIC, ALONG WITH A DOWNSTREAM UPPER  
RIDGE AXIS OVER THE PLAINS.  
   
..MODEL GUIDANCE EVALUATION
 
 
THE 00Z MODEL GUIDANCE SUITE IS INITIALLY IN VERY GOOD OVERALL  
AGREEMENT THROUGH THE EARLY-MIDDLE PART OF NEXT WEEK WITH ABOVE  
AVERAGE CONFIDENCE, AND ALTHOUGH MESOSCALE DIFFERENCES BECOME MORE  
APPARENT GOING FORWARD, THE OVERALL SYNOPTIC SCALE DEPICTION  
REMAINS GOOD THROUGH THE REMAINDER OF THE WEEK AND INTO SATURDAY.  
BY THURSDAY, THE GFS BECOMES MORE PROGRESSIVE WITH THE  
SHORTWAVE/SURFACE LOW CROSSING THE NORTHERN TIER STATES, BUT IS  
VERY CLOSE TO ITS ENSEMBLE MEAN. FOR THE END OF THE WEEK, THE CMC  
HOLDS THE AXIS OF THE UPPER TROUGH FARTHER BACK TO THE WEST  
COMPARED TO THE ECMWF AND THE ENSEMBLE MEANS, WHEREAS THE GFS IS  
FASTER TO LIFT THE TROUGH OUT OF THE INTERMOUNTAIN BY SATURDAY.  
THE WPC FORECAST WAS PRIMARILY DERIVED FROM A MULTI-DETERMINISTIC  
BLEND THROUGH WEDNESDAY, AND THEN GRADUALLY INCORPORATED MORE OF  
THE ECENS/GEFS MEANS FOR THE LATTER HALF OF THE FORECAST PERIOD.  
   
..SENSIBLE WEATHER/THREATS
 
 
IN THE PRECIPITATION DEPARTMENT, THE WEST COAST REGION IS EXPECTED  
TO REMAIN RATHER UNSETTLED WITH TWO WELL DEFINED EVENTS. THE  
FIRST ROUND OF RAIN AND MOUNTAIN SNOW IS EXPECTED LATE MONDAY INTO  
TUESDAY FROM NORTHERN CALIFORNIA TO WASHINGTON STATE, AND THE  
SECOND AND MORE IMPACTFUL SYSTEM ARRIVING THURSDAY AND EARLY  
FRIDAY, EXTENDING FARTHER SOUTH INTO CENTRAL CALIFORNIA AND ALSO  
AFFECTING AREAS TO THE NORTH. THIS LATE SEASON EVENT WILL DELIVER  
HIGHLY BENEFICIAL PRECIPITATION TO DROUGHT-STRICKEN AREAS OF  
CALIFORNIA, WITH THE POTENTIAL FOR UP TO THREE INCHES OF RAIN IN  
SOME AREAS NEXT WEEK, AND 1-3 FEET OF SNOW FOR THE SIERRA.  
ELSEWHERE ACROSS THE CONTINENTAL U.S., THE SURFACE LOW NEAR NEW  
ENGLAND IS EXPECTED TO RESULT IN WIDESPREAD RAIN, WIND, AND  
POTENTIALLY MODERATE TO HEAVY SNOW FOR THE HIGHER TERRAIN OF THE  
ADIRONDACKS AND EXTENDING TO NORTHERN MAINE THROUGH TUESDAY  
AFTERNOON. ANOTHER ROUND OF ORGANIZED SHOWERS AND STORMS IS  
LIKELY TO DEVELOP ACROSS THE CENTRAL U.S. AND EXTENDING NORTHWARD  
TO THE GREAT LAKES BY MIDWEEK AS GULF MOISTURE IS ADVECTED  
NORTHWARD AHEAD OF THE ORGANIZING STORM SYSTEM OVER THE CENTRAL  
PLAINS. ADDITIONAL MODERATE TO HEAVY SNOW IS ALSO EXPECTED FOR  
PORTIONS OF THE NORTHERN ROCKIES FOR THE END OF THE WEEK.  
 
TEMPERATURES ARE EXPECTED TO REMAIN RATHER CHILLY FROM THE  
NORTHERN PLAINS TO THE GREAT LAKES AND APPALACHIANS THROUGH ABOUT  
WEDNESDAY, AND THESE BELOW AVERAGE READINGS MAY PERSIST EVEN  
LONGER ACROSS NORTH DAKOTA AND NORTHERN MINNESOTA GOING THROUGH  
THE END OF THE WEEK. ON THE CONTRARY, WARM CONDITIONS ARE  
CURRENTLY EXPECTED ACROSS MUCH OF THE INTERIOR WESTERN U.S. FOR  
THE MAJORITY OF THE FORECAST PERIOD AHEAD OF THE UPPER TROUGH,  
WITH WELL ABOVE NORMAL READINGS PROBABLE ACROSS THE WESTERN HIGH  
PLAINS BY THE END OF THE WEEK AND INTO TEXAS. TEMPERATURES SHOULD  
ALSO MODERATE FOR THE EASTERN U.S. BY THURSDAY AS THE SURFACE HIGH  
MOVES OFF THE COAST AND WARMER SOUTHERLY FLOW COMMENCES. WINDY  
CONDITIONS ARE ALSO LIKELY FROM WESTERN TEXAS TO THE WESTERN  
DAKOTAS ON TUESDAY WITH STRONG SOUTHERLY FLOW EXPECTED.  
 
HAMRICK  
 
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, EXPERIMENTAL EXCESSIVE RAINFALL  
OUTLOOK, 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/#PAGE=ERO  
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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