439  
FXUS02 KWBC 261901  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT SAT MAR 26 2022  
 
VALID 12Z TUE MAR 29 2022 - 12Z SAT APR 02 2022  
 
...A DEEPENING LOW PRESSURE SYSTEM PRESENTS A MID-LATE NEXT WEEK  
HEAVY RAIN/SEVERE WEATHER THREAT ACROSS THE SOUTH WHILE HEAVY  
SNOW/ICE AND HIGH WIND THREAT FOCUS ACROSS THE UPPER MIDWEST/GREAT  
LAKES...  
   
..OVERVIEW
 
 
A RAPIDLY INTENSIFYING CYCLONE IS FORECAST TO TRACK ACROSS THE  
CENTRAL/SOUTHERN PLAINS THROUGH THE GREAT LAKES MID-LATE NEXT  
WEEK. THE UNSETTLED AND WET PATTERN INITIALLY OVER THE SOUTHWEST  
WILL BE FOLLOWED BY AN OUTBREAK OF HEAVY RAIN AND SEVERE WEATHER  
TO SWEEP ACROSS THE SOUTHERN TIER STATES THROUGH THURSDAY.  
MEANWHILE, HEAVY SNOW AND ICE ARE FORECAST FOR THE UPPER  
MIDWEST/UPPER GREAT LAKES REGION WHERE HIGH WINDS ARE ALSO  
EXPECTED. THE HIGH WINDS COULD ALSO EXTEND WELL TO THE WEST OF  
THE LOW TRACK ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
MODEL GUIDANCE THIS MORNING HAS COME INTO GENERAL AGREEMENT FOR A  
RAPIDLY INTENSIFYING CYCLONE TO TRACK ACROSS THE CENTRAL/SOUTHERN  
PLAINS THROUGH THE GREAT LAKES MID-LATE NEXT WEEK UNDER AN  
UPPER-LEVEL PATTERN THAT FAVORS PHASING OF THE COLD NORTHERN  
STREAM FLOW WITH A RESURGENCE OF MOIST SOUTHERN STREAM FLOW FROM  
THE GULF OF MEXICO. 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 3-6 FORECASTS. TOWARD THE END OF NEXT WEEK,  
MODELS BEGIN TO DIVERGE REGARDING THE AMPLITUDE OF NEXT UPPER  
TROUGH FORECAST TO DIVE ACROSS THE WESTERN U.S. THE CMC WAS MOST  
ENTHUSIASTIC WITH THE TROUGH AMPLIFICATION WHILE THE GFS/GEFS  
INDICATED A MUCH FLATTER EVOLUTION. THE ECMWF/EC MEAN WAS IN  
BETWEEN THESE EXTREMES. AN INTERMEDIATE SOLUTION WAS ADOPTED FOR  
DAY 7 BY INCORPORATING A HIGHER WEIGHTING FROM THE ENSEMBLE MEANS.  
THE SOLUTIONS MAINTAINED VERY GOOD CONTINUITY WITH THE PREVIOUS  
WPC FORECAST PACKAGE.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
AN UPPER LOW EJECTING ACROSS SOUTHERN CA/SOUTHWEST WILL SUPPORT A  
SPREAD OF ENHANCED RAIN AND HIGHER ELEVATION SNOW THROUGH THE  
SOUTH-CENTRAL INTERMOUNTAIN WEST/ROCKIES AND THE SOUTHWEST  
TUESDAY. AS A SURFACE LOW PRESSURE SYSTEM STRENGTHENS IN THE  
PLAINS AND TRACKS NORTHEAST, INCREASINGLY WIDESPREAD RAIN AND  
THREAT FOR SEVERE WEATHER WITH HEAVY DOWNPOURS ARE FORECAST TO  
DEVELOP OVER THE SOUTHERN PLAINS LATE TUESDAY AND THEN MOVE ACROSS  
THE SOUTH BY WEDNESDAY BEFORE REACHING THE SOUTHEAST ON THURSDAY.  
THE HEAVIEST RAINS ARE FORECAST TO BREAK OUT TUESDAY NIGHT OVER  
EASTERN PORTION OF THE SOUTHERN PLAINS AND THEN SWEEP THROUGH THE  
MID-SOUTH/GULF COAST STATES THROUGH THURSDAY WHERE AREAS OF FLASH  
FLOODING ARE POSSIBLE. AN EMERGING "SLIGHT" RISK AREA IS DEPICTED  
ON THE NEW EXPERIMENTAL WPC DAY 5 ERO GIVEN FAVORABLE SYSTEM  
INGREDIENTS AND ANTECEDENT CONDITIONS. MEANWHILE, LIGHT RAIN AND  
SOME THUNDERSTORMS ARE ALSO EXPECTED FARTHER NORTH FROM THE  
CENTRAL PLAINS THROUGH THE MID-ATLANTIC. ON THE NORTHERN SIDE OF  
THE PRECIPITATION SHIELD, THE POTENTIAL FOR A SWATH OF HEAVY  
WINTRY MIX AND ACCUMULATING DEEP LOW WRAPPING SNOWS HAVE CONTINUED  
TO INCREASE ACROSS THE UPPER MIDWEST TO THE GREAT LAKES LATER  
TUESDAY INTO WEDNESDAY-THURSDAY GIVEN MUCH MODEL CONSENSUS ON  
DEVELOPING A RATHER INTENSE CYCLONE. HIGH WINDS APPEAR TO LIKELY  
IMPACT NEAR AND WELL TO THE WEST OF THE LOW TRACK DURING THIS TIME  
FRAME AS WELL GIVEN THE IMPRESSIVE RATE OF CYCLOGENESIS. SOME  
WINTRY PRECIPITATION IS ALSO FORECAST FOR INTERIOR NEW ENGLAND  
LATE THURSDAY/EARLY FRIDAY AHEAD OF A WARM FRONT, WHILE POCKETS OF  
HEAVY RAIN ARE POSSIBLE DOWN THE EAST COAST AHEAD OF A COLD FRONT.  
OVER THE CENTRAL ROCKIES TO THE NEARBY HIGH PLAINS, A PERIOD OF  
HEAVY SNOW IS POSSIBLE FROM THE CENTRAL ROCKIES TO THE CENTRAL  
HIGH PLAINS ON TUESDAY BEHIND A REINFORCING COLD FRONT. BY LATE  
NEXT WEEK, ANOTHER UPPER TROUGH IS FORECAST TO DIG SOUTHEASTWARD  
FROM THE PACIFIC NORTHWEST THROUGH THE WESTERN U.S. AND COULD  
PROVIDE ANOTHER OPPORTUNITY FOR AN ENHANCED ROUND OF WINTRY MIX  
FROM THE NORTHERN TO CENTRAL ROCKIES TO THE NEARBY HIGH PLAINS.  
SOME HEAVY RAINFALL COULD LINGER ACROSS THE EASTERN GULF COAST BY  
NEXT WEEKEND AS A FRONT BECOMES NEARLY STATIONARY OFFSHORE.  
 
KONG  
 
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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