824  
FXUS02 KWBC 041849  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
247 PM EDT MON APR 04 2022  
 
VALID 12Z THU APR 07 2022 - 12Z MON APR 11 2022  
   
..OVERVIEW
 
 
OVERALL, THE LARGE SCALE REGIME FROM LATE THIS WEEK INTO EARLY  
NEXT WEEK WILL REMAIN AMPLIFIED BUT PROGRESSION/EVOLUTION DURING  
THE PERIOD WILL ESSENTIALLY LEAD TO A FLIP OF THE UPPER LEVEL  
PATTERN, WITH AN INITIAL WESTERN RIDGE/EAST-CENTRAL U.S. TROUGH  
ULTIMATELY TRENDING TOWARD A WESTERN TROUGH/EASTERN RIDGE.  
PRECIPITATION WILL STEADILY DECREASE IN COVERAGE AND INTENSITY  
OVER THE EASTERN HALF OF THE COUNTRY WHILE CHILLY TEMPERATURES  
WILL PROGRESS FROM THE PLAINS THROUGH EAST LATE WEEK THROUGH THE  
WEEKEND. MEANWHILE THE WEST WILL SEE MUCH ABOVE NORMAL  
TEMPERATURES LATE THIS WEEK, WITH SOME DAILY RECORDS POSSIBLE OVER  
AND NEAR CALIFORNIA, FOLLOWED BY A COOLER TREND DURING THE WEEKEND  
INTO EARLY NEXT WEEK WHILE AREAS OF PRECIPITATION SPREAD ACROSS  
THE REGION. AS THIS OCCURS, ABOVE NORMAL TEMPERATURES WILL SHIFT  
INTO THE PLAINS AND EVENTUALLY PARTS OF THE EAST.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
BASED ON 00/06 UTC GUIDANCE, BEST CLUSTERED GUIDANCE FROM THE  
LATEST GFS/ECMWF/CMC AND GEFS/ECMWF ENSEMBLE MEANS PROVIDED A GOOD  
DEPICTION OF CONSENSUS DAYS 3-7. THIS REMAINS TRUE FOR MOST OF  
THE LATEST 12 UTC GUIDANCE. HOWEVER, A NOTEABLE EXCEPTION IS THE  
12 UTC GFS THAT IS A STARK OUTLIER IN DELAYING BY 1-2 DAYS  
SIGNIFICANT UPPER TROUGH AMPLIFICATION OVER THE WEST FROM THE  
WEEKEND TO EARLY NEXT WEEK WITH THE NEXT MAJOR SHORTWAVE. THIS  
TREND IS NOT SUPPORTED BY OTHER GUIDANCE INCLUDING THE 12 UTC  
GEFS.  
 
CONTINUITY ADJUSTMENTS WERE AGAIN FAIRLY MODEST AND REPRESENTED  
TYPICAL RUN-TO-RUN DETAIL REFINEMENTS. THE OVERALL FORECAST OF  
THE DEEP EASTERN UPPER TROUGH AND ASSOCIATED SURFACE EVOLUTION IS  
FAIRLY CONSISTENT. THE MAJORITY CLUSTER MAINTAINS GOOD DEFINITION  
OF THE EMBEDDED UPPER LOW INTO DAY 4 FRIDAY, FOLLOWED BY SOLUTIONS  
SHOWING VARYING WAYS IN WHICH IT MAY WEAKEN/OPEN UP. UKMET RUNS  
HAVE BEEN THE FAST EXTREME WITH SHORTWAVE ENERGY ON THE EAST SIDE  
OF THE TROUGH AND THUS WITH THE MID-ATLANTIC THROUGH NEW ENGLAND  
COASTAL WAVE, BUT IS BEGINNING TO TREND FAVORABLY. THE  
ECMWF/ECMWF ENSEMBLE MEAN ARE A BIT ON THE SLOWER SIDE. AN  
INTERMEDIATE SOLUTION CONTINUES TO LOOK GOOD FOR DEPICTING THE  
SPECIFICS OF THE UPPER TROUGH AND SURFACE REFLECTION. FORECASTS  
OF THE UPPER TROUGH REACHING THE WEST HAVE BEEN A BIT MORE VARIED,  
DUE IN PART TO INVOLVEMENT OF SEPARATE SHORTWAVES. HOWEVER, BUT  
WITH THE AFOREMENTIONED EXCEPTION OF THE 12 UTC GFS, RECENT  
GFS/ECMWF/CMC RUNS STILL OVERALL COMPARE FAVORABLY TO EACH OTHER  
AND THE ENSEMBLE MEANS.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
HEAVIEST RAINFALL WITH THE SYSTEM AFFECTING THE EASTERN HALF OF  
THE COUNTRY SHOULD BE THURSDAY INTO FRIDAY AND FOCUSED BY THE  
TRIPLE POINT WAVE LIFTING FROM THE MID-ATLANTIC INTO NEW ENGLAND.  
SPECIFICS WITHIN THIS AREA OF POTENTIALLY ENHANCED RAIN ARE STILL  
UNCERTAIN, WITH ADDITIONAL TIME NEEDED TO RESOLVE IMPORTANT  
DETAILS. SOME POCKETS OF LOCALLY MODERATE TO HEAVY RAINFALL COULD  
EXTEND ALONG THE TRAILING FRONT AS FAR SOUTH AS FLORIDA, AND THE  
STORM PREDICTION CENTER IS MONITORING SEVERE POTENTIAL OVER PARTS  
OF THE MID-ATLANTIC. CHECK SPC'S OUTLOOKS FOR THE LATEST  
INFORMATION ON SEVERE THREATS. PRECIPITATION IN THE VICINITY OF  
THE GREAT LAKES LOW SHOULD TREND LIGHTER AFTER MIDWEEK. HOWEVER  
COLD AIR ALOFT ASSOCIATED WITH THE UPPER TROUGH WILL LIKELY  
PROMOTE AREAS OF DIURNALLY ENHANCED SHOWERS FROM THE MIDWEST INTO  
THE NORTHERN HALF TO TWO-THIRDS OF THE EAST INTO FRIDAY-SATURDAY.  
SOME PRECIPITATION COULD BE IN THE FORM OF SNOW BETWEEN THE  
MIDWEST AND APPALACHIANS. THE UPPER TROUGH AMPLIFYING OVER THE  
WEST WILL GRADUALLY INCREASE THE COVERAGE OF MOSTLY LIGHT TO  
MODERATE RAIN AND HIGHER ELEVATION SNOW FROM LATE WEEK ONWARD.  
MOST OF THIS PRECIPITATION SHOULD BE OVER THE NORTHERN HALF OF THE  
REGION INTO EARLY MONDAY BUT MAY PUSH FARTHER SOUTH THEREAFTER.  
 
THE UPPER RIDGE OVER THE WEST LATE THIS WEEK WILL PRODUCE WELL  
ABOVE NORMAL TEMPERATURES ACROSS THE REGION. FORECASTS CONTINUE TO  
SHOW HIGHS REACHING 15-25F ABOVE NORMAL THURSDAY-FRIDAY FROM PARTS  
OF CALIFORNIA AND OREGON INTO THE GREAT BASIN ALONG WITH SOME  
DAILY RECORDS FOR HIGHS/WARM LOWS. THEN THE UPPER TROUGH ARRIVING  
FROM THE PACIFIC WILL BRING IN COOLER AIR, WITH THE NORTHWEST  
TRENDING BELOW NORMAL DURING THE WEEKEND AND MUCH OF THE WEST  
LIKELY TO SEE HIGHS 5-15F BELOW NORMAL BY NEXT MONDAY. MEANWHILE  
HIGHS OF 5-15F OR SLIGHTLY MORE BELOW NORMAL WILL PROGRESS FROM  
THE PLAINS/MISSISSIPPI VALLEY INTO THE EAST LATE WEEK INTO THE  
WEEKEND. A TRAILING WARMING TREND WILL BRING PLUS 10-20F  
ANOMALIES INTO THE PLAINS FOR THE WEEKEND AND PERSISTING OVER SOME  
AREAS INTO MONDAY WHILE EASTERN U.S. READINGS REBOUND CLOSER TO OR  
SLIGHTLY ABOVE NORMAL BY EARLY NEXT WEEK.  
 
RAUSCH/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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