894  
FXUS02 KWBC 260708  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
307 AM 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 AND HEAVY  
SNOW/ICE THREAT FOCUS ACROSS THE UPPER MIDWEST/GREAT LAKES...  
   
..OVERVIEW
 
 
THE MAIN WEATHER FOCUS ACROSS THIS FINE NATION WILL WORK FROM THE  
SOUTHWEST TO THE SOUTH-CENTRAL ROCKIES TUESDAY. AS THE SYSTEM  
LIFTS ACROSS THE CENTRAL U.S. MID-LATER WEEK, GUIDANCE FAVORS  
AMPLE PHASING WITH NORTHERN STREAM TROUGH ENERGIES DIGGING INTO  
THE NORTHERN PLAINS THAT WOULD PROMOTE SOLID INTENSIFICATION OF A  
SURFACE LOW AND ASSOCIATED FRONTAL SYSTEMS. OVERALL, THIS WILL  
FAVOR RATHER UNSETTLED AND WET PATTERN FROM THE SOUTHWEST TO THE  
SOUTH-CENTRAL ROCKIES (INCLUDING MOUNTAIN SNOWS) THAT WILL  
EMERGE/EXPAND IN MAGNITUDE AND SPREAD FROM THE PLAINS INTO MIDWEEK  
IN AN ACTIVE SEVERE WEATHER PATTERN PER SPC TO A STILL ACTIVE  
EAST-CENTRAL AND EASTERN/SOUTHEASTERN U.S. LATER NEXT WEEK AS GULF  
MOISTURE/INSTABILITY IS INCREASINGLY FED INTO THE DEEP LOW/DYNAMIC  
SYSTEM AND FRONTS IN A PATTERN WITH COUPLED UPPER JET SUPPORT.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
A COMPOSITE OF THE 18 UTC GFS AND 12 UTC ECMWF/UKMET/CANADIAN  
ALONG WITH THE 01 UTC NBM SEEMS TO OFFER A RUN TO RUN CONSISTENT  
FORECAST DAYS 3/4 (TUESDAY-WEDNESDAY) THAT ENJOYS GOOD  
GEFS/NAEFS/ECMWF ENSEMBLE SUPPORT. FORECAST CLUSTERING HAS  
IMPROVED THROUGH MEDIUM RANGE TIME SCALES. HOWEVER, THE 12 UTC  
ECMWF/ECMWF ENSEMBLE MEAN SEEMS BEST IN LINE BEST IN LINE WITH WPC  
CONTINUITY DAYS 5-7 (THURSDAY-NEXT SATURDAY), SO HAVE ADJUSTED NBM  
GUIDANCE STRONGLY TOWARD THIS GUIDANCE. THIS BLEND OFFERS GOOD  
PRODUCT DETAIL CONSISTENT WITH A PATTERN WITH GRADUALLY LOWERING  
BUT STILL ABOVE NORMAL PREDICTABILITY. A LINGERING GUIDANCE  
DIFFERENCE IN THIS TIME FRAME CONCERNS UPPER TROUGH/SYSTEM  
AMPLIFICATION BACK OVER THE WEST WELL UPSTREAM OF THE MAIN LEAD  
CENTRAL TO EASTERN U.S. STORM. OVERALL, THE 12 UTC  
ECMWF/UKMET/CANADIAN AND ECMWF/CANADIAN ENSEMBLE MEANS AND THEIR  
LATEST 00 UTC VERSIONS DEVELOP A MORE AMPLIFIED EASTERN PACIFIC  
UPPER RIDGE THAN THE 18 UTC GFS/GEFS MEAN. THIS ALLOWS FOR DEEPER  
TROUGH DIGGING BACK INTO THE WEST LATE NEXT WEEK. THE 00 UTC  
GFS/GEFS MEAN HAS TRENDED IN THIS DIRECTION.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
A EJECTING SOUTHERN CA/SOUTHWEST UPPER LOW WILL SUPPORT A SPREAD  
OF ENHANCED RAIN AND HIGHER ELEVATION SNOW ACROSS THE REGION TO  
THE SOUTH-CENTRAL INTERMOUNTAIN WEST/ROCKIES TUESDAY. AS SURFACE  
LOW PRESSURE STRENGTHENS IN THE PLAINS AND TRACKS NORTHEAST,  
INCREASINGLY WIDESPREAD RAIN AND THE 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 MOVE THROUGH THE EASTERN SOUTHERN PLAINS THROUGH THE  
MID-SOUTH/GULF COAST STATES TUESDAY NIGHT 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  
INCREASED ACROSS THE UPPER MIDWEST TO THE GREAT LAKES LATER  
TUESDAY INTO WEDNESDAY-THURSDAY. HIGH WINDS COULD ALSO BE AN  
IMPACT DURING THIS TIME FRAME. 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 THEN  
DOWN THE EAST COAST AHEAD OF A COLD FRONT. OVER THE CENTRAL  
ROCKIES TO THE NEARBY HIGH PLAINS, THE TREND TOWARD A STRONGER  
SURGE OF COLD AIR DOWN THE HIGH PLAINS HAS ALSO INCREASED THE  
POTENTIAL FOR HEAVIER SNOWFALL FROM THE CENTRAL ROCKIES TO THE  
CENTRAL HIGH PLAINS ON TUESDAY. 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.  
 
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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