617  
FXUS02 KWBC 310701  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 AM EDT THU MAR 31 2022  
 
VALID 12Z SUN APR 03 2022 - 12Z THU APR 07 2022  
 
...HEAVY RAINFALL/CONVECTION AND RUNOFF THREAT TO FOCUS ACROSS THE  
SOUTH NEXT WEEK...  
...PACIFIC NORTHWEST HEAVY RAINS AND TERRAIN/MOUNTAIN HEAVY SNOW  
THREAT INLAND TO THE NORTHERN ROCKIES...  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
THE WPC MEDIUM RANGE PRODUCT SUITE WAS MAINLY DERIVED FROM A BLEND  
OF WELL CLUSTERED GUIDANCE FROM THE 18 UTC GFS/GEFS MEAN, THE 12  
UTC ECMWF/UKMET/CANADIAN/ECMWF ENSEMBLE MEAN AND THE 01 UTC  
NATIONAL BLEND OF MODELS ALONG WITH WPC CONTINUITY DAYS 3-7  
(SUN-NEXT THU). EMBEDDED SMALLER SCALE SYSTEM DIFFERENCES AND RUN  
TO RUN CONTINUITY VARIANCES HAVE BECOME LESS PROBLEMATIC WITH THE  
18 UTC GFS/GEFS TRENDING MORE IN LINE THAN EARLIER RUNS,  
ESPECIALLY INTO LATER PERIOD OVER THE PACIFIC/NORTHWEST. NEWER 00  
UTC GUIDANCE REMAINS IN CLOSE ALIGNMENT. OVERALL, THIS SEEMS TO  
BOLSTER MEDIUM RANGE FORECAST CONFIDENCE TO ABOVE NORMAL LEVELS,  
ALBEIT WITH THE CAVEAT THAT THE ENERGETIC MULTI-SYSTEM PATTERN IS  
ALSO TRANSITIONING TO HIGHER AMPLITUDE/CONVECTIVE POTENTIAL OVER  
TIME THAT WILL LIKELY VARY THE LOCAL THREAT FOCUS.  
   
..OVERVIEW AND WEATHER HIGHLIGHTS/THREATS
 
 
HIGHLY ENERGETIC PACIFIC FLOW WILL WORK INCREASINGLY INLAND FROM  
THE NORTHWEST TO THE ROCKIES INTO EARLY NEXT WEEK. THIS WILL ACT  
TO TRANSPORT SOME DEEPER MOISTURE IN SUPPORT OF AN EMERGING HEAVY  
PRECIPITATION FOCUS WITH RAINFALL OVER COASTAL AND FAVRORED  
TERRAIN OF THE PACIFIC NORTHWEST. THE PATTERN ALSO FAVORS PERIODS  
WITH TERRAIN/MOUNTAIN HEAVY SNOWS FROM THE NORTHWEST TO THE  
NORTHERN INTERMOUNTAIN WEST/ROCKIES PRIOR TO AMPLIFIED UPPER RIDGE  
BUILDING SLATED TO BUILD EASTWARD OVER THE WEST STARTING MIDWEEK.  
 
DOWNSTREAM PROGRESSION AND SYSTEMS OUT FROM THE WEST AND  
INCREASING NORTHERN STREAM PHASING POTENTIAL OVER TIME WILL  
COMBINE TO SUPPORT CYCLOGENESIS/FRONTOGENESIS OVER THE CENTRAL AND  
EASTERN STATES NEXT WEEK. THERE IS A GROWING GUIDANCE SIGNAL FOR  
DEVELOPMENT OF A BUILDING AREA OF ENHANCED RAINFALL AND SOME  
THREAT TO MONITOR FOR SOME SEVERE CONVECTION ACROSS THE  
EAST-CENTRAL U.S. (BOTH ESPECIALLY ACROSS A MORE  
UNSTABLE/CONVECTIVE SOUTH) EARLY-MID NEXT WEEK AS DEEPER GULF  
MOISTURE RETURNS AND INTERACTS WITH THE COMPLEX SERIES OF WAVY  
FRONTS AND A STALLED LEAD FRONT. ACCORDINGLY AND CONSIDERING  
ANTECEDENT RAINFALL, WPC SHOWS A "SLIGHT" RISK ON THE NEWLY  
EXPERIMENTAL MEDIUM RANGE EXCESSIVE RAINFALL OUTLOOK INTO DAY 5  
(ERO LINKED BELOW). GUIDANCE CONSENSUS HAS IMPROVED AT LONGER TIME  
FRAMES WITH A WELL DEVELOPED CLOSED UPPER LOW FORMING OVER THE  
NORTH-CENTRAL U.S. BY MIDWEEK AS THE PATTERN BECOMES AMPLIFIED  
DOWNSTREAM OF THE AFOREMENTIONED BUILDING UPPER RIDGE OVER THE  
WEST. THERE IS SOME POTENTIAL THEN FOR SOME WRAPPING/OVERRUNNING  
APRIL SNOWS FROM THE UPPER GREAT LAKES TO THE NORTHERN TIER OF THE  
NORTHEAST.  
 
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, 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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