713  
FXUS02 KWBC 150656  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
256 AM EDT FRI APR 15 2022  
 
VALID 12Z MON APR 18 2022 - 12Z FRI APR 22 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 SURFACE LOW  
OVER THE GREAT LAKES WITH A TRAILING COLD FRONT THAT WILL REACH  
THE EAST COAST AROUND MONDAY NIGHT, WITH A TRIPLE POINT LOW LIKELY  
DEVELOPING NEAR THE NORTHEAST U.S. ON TUESDAY. 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 NEXT 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, AND ALTHOUGH  
MESOSCALE DIFFERENCES BECOME MORE APPARENT GOING FORWARD, THE  
OVERALL SYNOPTIC SCALE DEPICTION REMAINS GOOD THROUGH THE  
REMAINDER OF THE WEEK. ONE OF THE MORE NOTICEABLE CHANGES IN THE  
GUIDANCE IS WITH THE 00Z ECMWF BEING MUCH MORE PROGRESSIVE WITH  
THE BUILDING TROUGH OVER THE WESTERN U.S. BY NEXT FRIDAY COMPARED  
TO ITS PRIOR 12Z RUN, AND ALSO AHEAD OF THE 00Z MODEL CONSENSUS.  
THEREFORE THE 12Z ECMWF WOULD BE PREFERABLE FOR THE  
CENTRAL/WESTERN PART OF THE U.S. INSTEAD OF THE LATEST 00Z RUN.  
THE 00Z GFS/CMC/GEFS APPEAR TO HANDLE THAT TROUGH WELL, ALONG WITH  
THE 12Z ECENS/ECMWF. THE WPC FORECAST WAS PRIMARILY DERIVED FROM  
A MULTI-DETERMINISTIC BLEND THROUGH TUESDAY, AND THEN GRADUALLY  
INCORPORATED MORE OF THE ECENS/GEFS MEANS FOR THE LATTER HALF OF  
NEXT WEEK.  
   
..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 ARRIVING THURSDAY AND EARLY FRIDAY, EXTENDING FARTHER SOUTH  
INTO CENTRAL CALIFORNIA AND ALSO AFFECTING AREAS TO THE NORTH.  
THIS WILL BE 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 1-2 FEET OF SNOW FOR THE SIERRA.  
ELSEWHERE ACROSS THE CONTINENTAL U.S., SHOWERS AND THUNDERSTORMS  
WILL BE EXITING THE EAST COAST REGION EARLY IN THE WEEK, FOLLOWED  
BY DRY WEATHER AS HIGH PRESSURE SETTLES INTO THE REGION. ANOTHER  
ROUND OF ORGANIZED SHOWERS AND STORMS IS LIKELY ACROSS THE CENTRAL  
U.S. BY MIDWEEK AS GULF MOISTURE IS ADVECTED NORTHWARD AHEAD OF  
THE ORGANIZING STORM SYSTEM OVER THE CENTRAL PLAINS.  
 
TEMPERATURES ARE EXPECTED TO REMAIN RATHER CHILLY FROM THE  
NORTHERN PLAINS TO THE GREAT LAKES AND APPALACHIANS THROUGH MUCH  
OF THE UPCOMING WEEK, AND THESE BELOW AVERAGE READINGS SHOULD ALSO  
INCLUDE MUCH OF THE EAST COAST REGION THROUGH ABOUT WEDNESDAY AS  
THE COLD CANADIAN SURFACE HIGH GOVERNS THE WEATHER PATTERN. ON  
THE CONTRARY, WARM CONDITIONS ARE CURRENTLY EXPECTED ACROSS MUCH  
OF THE INTERIOR WESTERN U.S. FOR THE MAJORITY OF THE FORECAST  
PERIOD, WITH ABOVE NORMAL READINGS PROBABLE ACROSS THE CENTRAL AND  
SOUTHERN PLAINS ON WEDNESDAY AHEAD OF THE COLD FRONT.  
TEMPERATURES SHOULD ALSO MODERATE FOR THE EASTERN U.S. BY THURSDAY  
AS THE SURFACE HIGH MOVES OFF THE COAST AND WARMER SOUTHERLY FLOW  
COMMENCES.  
 
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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