463  
FXUS02 KWBC 241852  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
251 PM EDT THU MAR 24 2022  
 
VALID 12Z SUN MAR 27 2022 - 12Z THU MAR 31 2022  
 
...RECORD WARMTH AND COLD LIKELY NEXT WEEK FOR DIFFERENT PARTS OF  
THE LOWER 48 IN DYNAMIC SPRINGTIME PATTERN...  
 
   
..OVERVIEW
 
 
A STRONG UPPER TROUGH AND EMBEDDED CLOSED LOW WILL PROGRESS  
INTO/THROUGH THE SOUTHWESTERN STATES EARLY NEXT WEEK BEFORE  
LIFTING INTO THE CENTRAL PLAINS/GREAT LAKES BY NEXT WED/THU. THIS  
WILL PROMOTE A RATHER WET PATTERN FOR THE SOUTHWEST/FOUR CORNERS  
REGION INTO THE PLAINS AND EVENTUALLY THE SOUTHEAST THROUGH THE  
WEEK. COLDER THAN NORMAL TEMPERATURES WITHIN THE TROUGH MAY  
FEATURE RECORD COLD TEMPERATURES FOR PARTS OF THE GREAT LAKES AND  
NORTHEAST (WITH SNOW OVER THE NORTHERN TIER) WHILE RIDGING AHEAD  
OF THE INCOMING WESTERN TROUGH MAY FEATURE RECORD WARMTH OVER THE  
INTERIOR WEST INTO THE SOUTHERN PLAINS.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
THOUGH THE UPPER PATTERN FALLS IN THE USUALLY MORE PREDICTABLE  
PHASE BETWEEN ZONAL AND BLOCKY FLOW (INHERENTLY LESS PREDICTABLE  
FOR DIFFERENT REASONS), THERE WAS AN ADDED COMPLICATION TO THE  
FORECAST; NAMELY, SEPARATE NORTHERN AND SOUTHERN STREAM FLOW OUT  
OF THE PACIFIC INTO THE WEST. THE 00Z/06Z GFS RUNS WERE QUITE  
DIFFERENT THAN THE PREFERRED CLUSTER OF THE 00Z  
ECMWF/CANADIAN/UKMET/ECMWF ENSEMBLE MEAN IN THEIR HANDLING OF THE  
NORTHERN STREAM (MUCH SLOWER) SO THAT IT RESULTED IN A STRONGER  
AND MUCH SLOWER SYSTEM NEXT WEEK THROUGH THE PLAINS. THIS WAS  
EVIDENCED BY MANY 06Z GEFS MEMBERS ON THE SLOWER SIDE BUT WITH  
PERHAPS JUST AS MANY QUICKER MEMBERS NEARER TO THE ECMWF/CMCE  
CONSENSUS, WHICH WAS NEAR THE LARGEST OVERLAP AMONG THE THREE  
ENSEMBLE SYSTEMS. NOTE THAT THE 12Z GFS DID QUICKEN ITS PACE  
TOWARD THE ECMWF/CANADIAN-LED CLUSTER. BY THE END OF THE PERIOD, A  
POSITIVELY-TILTED TROUGH BETWEEN THE NORTHERN AND SOUTHERN STREAMS  
SHOULD MOVE EAST OF THE PLAINS AS A WEAKER SHORTWAVE COMES INTO  
THE PAC NW. DESPITE THE GOOD AGREEMENT BETWEEN THE ECMWF AND  
CANADIAN EVEN INTO NEXT THURSDAY, INCREASED THE WEIGHTING OF THE  
00Z ECMWF ENSEMBLE MEAN WITH TIME TO ACCOUNT FOR UNCERTAINTY AS  
THE SYSTEM COULD STILL TREND A BIT DEEPER/SLOWER AS SHOWN BY SOME  
OF ITS ENSEMBLE MEMBERS.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
LIGHT PRECIPITATION COULD LINGER ACROSS THE GREAT LAKES REGION AND  
NORTHEAST EARLY IN THE PERIOD GIVEN STRONG CYCLONIC FLOW AND  
COASTAL LOW PRESSURE SYSTEMS. AS THE NEXT SYSTEM MOVES INTO THE  
WESTERN U.S. EARLY NEXT WEEK, UNSETTLED AND ACTIVE WEATHER IS  
EXPECTED FOR THE WEST COAST STATES SUNDAY, WHICH COULD BRING  
MOSTLY BENEFICIAL AND WELCOME RAINS TO THE VALLEYS. HIGHER  
ELEVATION AREAS OF THE SIERRA COULD SEE SEE SEVERAL INCHES OR MORE  
OF SNOW. CURRENT MODEL GUIDANCE SHOWS THE HEAVIEST RAIN TOTALS FOR  
SOUTHERN CALIFORNIA SUNDAY AND MONDAY ESPECIALLY ENHANCED BY  
HIGHER TERRAIN, WHICH 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 THUNDERSTORMS ARE LIKELY FOR  
THE SOUTHERN PLAINS/LOWER MISSISSIPPI VALLEY TUESDAY AND  
WEDNESDAY. MEANWHILE ON THE NORTHERN SIDE OF THE PRECIPITATION  
SHIELD, A WINTRY MIX AND ACCUMULATING SNOW ARE POSSIBLE FOR THE  
NORTHERN TIER AROUND THE GREAT LAKES AND POTENTIALLY INTO THE  
NORTHEAST. RAINFALL COULD REMAIN HEAVY THROUGH THE SOUTHEAST INTO  
NEXT THURSDAY.  
 
UNSEASONABLY WARM TEMPERATURES ARE LIKELY UNDERNEATH UPPER RIDGING  
FROM THE WESTERN STATES INTO THE PLAINS EARLY NEXT WEEK, AND  
TEMPERATURES OF 10-25F ABOVE NORMAL WILL BE COMMON. THOUGH  
EXPANSIVE RECORD-BREAKING WARMTH WILL OCCUR IN THE SHORT RANGE,  
SOME RECORD HIGHS AND HIGH MINIMUM TEMPERATURES COULD BE SET OR  
TIED SUNDAY AND MONDAY. TEMPERATURES IN THE WEST WILL BE NEAR TO  
BELOW NORMAL AS THE COLD FRONT MOVES THROUGH. MUCH OF THE EAST  
WILL SEE BELOW NORMAL TEMPERATURES EARLY IN THE WEEK, PERHAPS BY  
AS MUCH AS 10-25F. FREEZING TEMPERATURES OVERNIGHT MAY DIP INTO  
PARTS OF THE CAROLINAS. A MODERATION IN TEMPERATURES SHOULD  
COMMENCE BY WEDNESDAY AHEAD OF THE STORM IN THE PLAINS.  
 
FRACASSO/TATE  
 
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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