611  
FXUS02 KWBC 251932  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
331 PM EDT FRI MAR 25 2022  
 
VALID 12Z MON MAR 28 2022 - 12Z FRI APR 01 2022  
 
...WET WEATHER MOVING THROUGH SOUTHERN CALIFORNIA EARLY NEXT WEEK  
WILL BE FOLLOWED BY LOW PRESSURE SYSTEM INTENSIFYING OVER THE  
PLAINS MID-LATE WEEK TO BRING HEAVY RAIN/SEVERE WEATHER ACROSS THE  
SOUTH AND INCREASING POTENTIAL OF HEAVY SNOW/ICE ACROSS THE UPPER  
GREAT LAKES TO UPPER MIDWEST...  
   
..OVERVIEW
 
 
AN AMPLIFIED UPPER TROUGH AND LINGERING WINTRY WEATHER WILL EXIT  
THE NORTHEASTERN U.S. BY EARLY NEXT WEEK, FOLLOWED BY A GRADUAL  
MODERATION OF A POLAR AIRMASS ACROSS THE NORTH-CENTRAL THROUGH  
EASTERN STATES. THE MAIN WEATHER FOCUS ACROSS THE NATION WILL  
THEN SHIFT TO THE WEST AS A STRONG UPPER TROUGH AND EMBEDDED  
CLOSED LOW PROGRESS INTO AND THROUGH THE SOUTHWESTERN STATES EARLY  
NEXT WEEK. AS THE SYSTEM LIFTS ACROSS THE SOUTH-CENTRAL  
ROCKIES/PLAINS MIDWEEK, MODEL GUIDANCE CONTINUES TO TREND TOWARD  
SUPPORTING ADDITIONAL PHASING WITH NORTHERN STREAM TROUGH ENERGIES  
DIGGING INTO THE NORTHERN PLAINS MID TO LATE WEEK THAT WOULD  
PROMOTE MORE SOLID INTENSIFICATION OF A SURFACE LOW AND ASSOCIATED  
FRONTAL SYSTEMS. OVERALL, THIS WILL FAVOR RATHER UNSETTLED AND  
WET PATTERN FROM CALIFORNIA AND THE SOUTHWEST TO THE SOUTH-CENTRAL  
ROCKIES EARLY NEXT WEEK (INCLUDING MOUNTAIN SNOWS) THAT WILL  
EMERGE/EXPAND IN MAGNITUDE AND SPREAD FROM THE PLAINS TO THE  
EAST-CENTRAL AND EASTERN/SOUTHEASTERN U.S. LATER NEXT WEEK AS MORE  
GULF MOISTURE IS FED INTO THE SYSTEM.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
SINCE YESTERDAY, MODEL GUIDANCE HAS CONTINUED THE TREND OF  
INCREASING INTERACTION/PHASING BETWEEN A DEVELOPING SURFACE LOW  
OVER THE SOUTHERN PLAINS ON WEDNESDAY AND A SURGE OF COLDER AIR  
DOWN THE NORTHERN AND CENTRAL PLAINS. THE GFS TOOK THE MOST  
DECISIVE SHIFT OF TRACKING A RATHER ROBUST CYCLONE INTO THE UPPER  
MIDWEST BY THURSDAY MORNING IN RECENT RUNS. THE 00Z ECMWF AND, TO  
THE LESSER EXTENT, THE 00Z CMC HAVE TRENDED TOWARD A MORE ROBUST  
CYCLOGENESIS. THE 12Z ECMWF, CMC, AS WELL AS THE GFS HAVE NOW  
AGREED WITH THIS SCENARIO. THE ENSEMBLE MEANS FROM EARLIER THIS  
MORNING HAVE ALSO INDICATED SUCH A TREND. IN ADDITION, THIS TREND  
HAS ALSO LED TO A BETTER-DEFINED REINFORCING SURGE OF COLD AIR  
DOWN THE NORTHERN AND CENTRAL HIGH PLAINS TUESDAY-WEDNESDAY  
COMPARED WITH PREVIOUS FORECASTS.  
 
THE WPC MEDIUM-RANGE FORECAST PACKAGE WAS BASED ON A BLEND OF 40%  
FROM THE 00Z ECMWF/EC MEAN, 40% FROM THE 06Z GFS/GEFS, AND 20%  
FROM THE 00Z CMC AND CMC MEAN. ONLY A MINIMAL CONTRIBUTION FROM  
THE 00Z CMC WAS INCLUDED STARTING ON DAY 5, WHICH FAVORS THE  
CYCLOGENESIS SCENARIO FARTHER WEST OVER THE UPPER MIDWEST AS  
SUPPORTED BY THE 00Z CMC MEAN AS WELL AS THE 00Z EC/06Z GFS/GEFS  
CONSENSUS.  
 
   
..WEATHER HIGHLIGHTS/THREATS
 
 
THE MEDIUM-RANGE PERIOD WILL BEGIN WITH A VIGOROUS UPPER LOW  
MOVING ONSHORE OVER THE SOUTHWESTERN U.S. ON MONDAY. THE HEAVIEST  
RAIN TOTALS FOR SOUTHERN CALIFORNIA WILL LIKELY BE ENHANCED BY  
HIGHER TERRAIN AND COULD CAUSE FLOODING ISSUES IF HEAVY RAIN FALLS  
OVER BURN SCAR AREAS. RAIN AND HIGHER ELEVATION SNOW WILL SPREAD  
ACROSS THE INTERMOUNTAIN WEST AND ROCKIES MONDAY AND TUESDAY. AS  
SURFACE LOW PRESSURE STRENGTHENS IN THE PLAINS AND TRACKS EAST,  
MORE WIDESPREAD RAIN AND POSSIBLY SEVERE THUNDERSTORMS WITH HEAVY  
DOWNPOURS ARE FORECAST TO DEVELOP OVER THE SOUTHERN PLAINS LATE  
TUESDAY AND THEN MOVE ACROSS THE SOUTH ON WEDNESDAY BEFORE  
REACHING THE SOUTHEAST ON THURSDAY. THE HEAVIEST RAINS ARE  
FORECAST TO MOVE THROUGH EASTERN OKLAHOMA AS WELL AS THE GULF  
COAST STATES TUESDAY NIGHT THROUGH THURSDAY WHERE AREAS OF FLASH  
FLOODING ARE POSSIBLE. 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 SNOWS HAVE INCREASED ACROSS THE UPPER GREAT  
LAKES INTO THE UPPER MIDWEST WEDNESDAY-THURSDAY. DEPENDING ON THE  
STRENGTH AND SIZE OF THE INTENSIFYING CYCLONE, HIGH WINDS COULD  
ALSO IMPACT A LARGE PORTION OF THE NORTHERN U.S. 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 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.  
 
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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