524  
FXUS02 KWBC 271901  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT SUN MAR 27 2022  
 
VALID 12Z WED MAR 30 2022 - 12Z SUN APR 03 2022  
 
...A RAPIDLY DEEPENING LOW PRESSURE SYSTEM PRESENTS A MID-LATE  
NEXT WEEK HEAVY RAIN/SEVERE WEATHER THREAT FOCUS ACROSS THE SOUTH  
WHILE HEAVY SNOW/ICE AND HIGH WIND THREAT FOCUS ACROSS THE UPPER  
MIDWEST/GREAT LAKES...  
 
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
MODEL GUIDANCE THIS MORNING CONTINUES TO INDICATE THE LIKELIHOOD  
OF A RAPIDLY DEEPENING CYCLONE TO TRACK FROM THE CENTRAL PLAINS  
THROUGH THE GREAT LAKES WEDNESDAY-THURSDAY. MODEL CONSENSUS  
APPEARS TO TREND TOWARD A FASTER PROGRESSION OF THE CYCLONE CENTER  
THROUGH THE GREAT LAKES IN BETTER AGREEMENT WITH EARLIER GFS RUNS.  
IN ADDITION, THERE HAS BEEN A GRADUAL EASTWARD SHIFT IN THE  
RAINFALL MAXIMUM ACROSS THE DEEP SOUTH WITH A SLIGHTLY FASTER  
EASTWARD MOTION OF THE SOUTHERN STREAM LOW. THIS EASTWARD SHIFT  
MIGHT HAVE CEASED IN THE MOST RECENT COUPLE OF MODEL CYCLES. THE  
FASTER SOUTHERN STREAM LOW ALSO RESULTED IN A FASTER PROGRESSION  
OF THE COLD FRONT THROUGH THE EASTERN U.S. THURSDAY-FRIDAY.  
 
MEANWHILE, THE NEXT UPPER TROUGH FROM THE PACIFIC WILL COME INTO  
PLAY BY MIDWEEK AS IT REACHES THE PACIFIC NORTHWEST. MODELS HAVE  
BEEN SHOWING DIFFICULTIES IN HANDLING AND RESOLVING THE TIMING AND  
EVOLUTION OF THIS SYSTEM AS IT HEADS DOWNSTREAM. IT APPEARS THAT  
THE CONSENSUS IS FOR THE SYSTEM TO GENERALLY GLIDE SOUTHEASTWARD  
ACROSS THE WESTERN U.S. LATE THIS WEEK AS THE ECMWF AND CMC HAVE  
ADOPTED A LESS AMPLIFIED SOLUTION COMPARED WITH EARLIER RUNS.  
THIS WOULD FAVOR FRONTAL WAVE DEVELOPMENT BY THE WEEKEND OVER THE  
CENTRAL PLAINS AS SUPPORTED BY THE ECMWF. THE TIMING OF THE  
PROGRESSION OF THE UPPER TROUGH DOWNSTREAM IS SUBJECT TO LARGE  
UNCERTAINTY HOWEVER. AT PRESENT, THE CONSENSUS SUPPORTS A FRONTAL  
WAVE TO MOVE ACROSS THE SOUTHEAST LATE THIS WEEKEND AFTER A  
POTENTIAL RESURGENCE OF GULF MOISTURE LATE NEXT WEEK ACROSS THE  
CENTRAL AND EASTERN GULF COAST STATES NORTH OF A STATIONARY  
BOUNDARY.  
 
A COMPOSITE BLEND OF 40% 00Z ECMWF/EC MEAN, 40% 06Z GFS/GEFS AND  
20% FROM THE 00Z CMC/CMC MEAN WAS USED TO COMPOSE THE DAYS 3-5  
FORECASTS, TRANSITIONING TO MOSTLY A CONSENSUS OF THE ENSEMBLE  
MEANS BY DAY 7. THE RESULTS COMPARE WELL WITH WPC CONTINUITY.  
THE TIMING OF THE UPPER TROUGH/FRONTAL WAVE ACROSS THE MID-SECTION  
OF THE COUNTRY IS THE MOST UNCERTAIN PART OF THE FORECASTS.  
 
   
..OVERVIEW AND WEATHER HIGHLIGHTS/THREATS
 
 
AS A MAIN SURFACE LOW PRESSURE SYSTEM OVER THE PLAINS STRENGTHENS  
AND TRACKS NORTHEAST, INCREASINGLY WIDESPREAD RAIN WITH HEAVY  
DOWNPOURS AND A THREAT FOR SEVERE WEATHER ARE FORECAST ACROSS THE  
SOUTH INTO WEDNESDAY BEFORE SPREADING OVER THE  
SOUTHEAST/MID-ATLANTIC THURSDAY. A "SLIGHT" RISK AREA REMAINS  
DEPICTED ON THE WPC EXPERIMENTAL MEDIUM RANGE EXCESSIVE RAINFALL  
OUTLOOK (ERO) FOR WEDNESDAY GIVEN FAVORABLE SYSTEM INGREDIENTS AND  
ANTECEDENT CONDITIONS. MEANWHILE, RAIN AND THUNDERSTORMS ARE ALSO  
EXPECTED FARTHER NORTH FROM THE CENTRAL PLAINS THROUGH THE EAST  
WITH WAVY FRONTAL PROGRESSION ACROSS THE REGION.  
 
ON THE NORTHERN SIDE OF THE PRECIPITATION SHIELD, EXPECT A SWATH  
OF HEAVY WINTRY MIX AND ACCUMULATING SNOWS FROM THE UPPER MIDWEST  
TO THE GREAT LAKES INTO WEDNESDAY-THURSDAY GIVEN CONTINUED  
EXCELLENT MODEL CONSENSUS ON DEVELOPING A RATHER INTENSE CYCLONE.  
IN ADDITION, HIGH WINDS APPEAR LIKELY NEAR AND WELL TO THE WEST OF  
THE LOW TRACK GIVEN THE IMPRESSIVE RATE OF CYCLOGENESIS. SOME  
WINTRY PRECIPITATION IS ALSO FORECAST FOR NORTHERN NEW ENGLAND  
AHEAD OF AND ON THE BACK SIDE OF THIS SYSTEM.  
 
LATE WEEK, ADDITIONAL UPPER TROUGH ENERGIES FORECAST TO DIG WITH  
SOME UNCERTAINTY SOUTHEASTWARD FROM THE PACIFIC NORTHWEST THROUGH  
THE WEST COULD PROVIDE ANOTHER OPPORTUNITY FOR AN ENHANCED ROUND  
OF WINTRY WEATHER, MAINLY FOR THE NORTHERN TO CENTRAL  
INTERMOUNTAIN WEST/ROCKIES TO THE HIGH PLAINS. POTENTIAL SYSTEM  
AMPLITUDE AND PROGRESSION INTO NEXT WEEKEND WOULD FAVOR RETURN  
MOISTURE FLOW INTO AN INCREASINGLY WAVY/LIFTING FRONT. THIS MAY  
SUPPORT RENEWED HEAVY RAINFALL POTENTIAL ACROSS THE  
CENTRAL/EASTERN GULF COAST STATES AND SOUTHEAST NEXT WEEKEND.  
 
KONG/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  
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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