424  
FXUS02 KWBC 160700  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
258 AM EDT WED MAR 16 2022  
 
VALID 12Z SAT MAR 19 2022 - 12Z WED MAR 23 2022  
 
***STRONG LOW PRESSURE SYSTEM WILL LIKELY PRODUCE HEAVY RAIN AND  
SEVERE STORMS ACROSS PORTIONS OF THE SOUTHERN U.S. BY EARLY NEXT  
WEEK***  
   
..OVERVIEW
 
 
A RATHER ACTIVE WEATHER PATTERN WILL BE DEVELOPING ACROSS MUCH OF  
THE NATION BEGINNING THIS WEEKEND, AND PARTICULARLY INTO THE  
BEGINNING OF NEXT WEEK AS A DEEP UPPER LEVEL TROUGH DEVELOPS OVER  
THE INTERMOUNTAIN WEST AS PACIFIC SHORTWAVE ENERGY MOVES INLAND.  
THIS WILL LIKELY EVOLVE INTO A CLOSED UPPER LOW BY MONDAY ALONG  
WITH AN INTENSIFYING SURFACE LOW OVER THE CENTRAL/SOUTHERN PLAINS  
THAT WILL EVENTUALLY RESULT IN HEAVY RAIN AND SEVERE STORMS FROM  
TEXAS TO THE DEEP SOUTH BY THE END OF THE FORECAST PERIOD. THERE  
WILL ALSO BE A WELL ORGANIZED STORM SYSTEM ACROSS THE NORTHEAST  
U.S. THIS WEEKEND AHEAD OF THE CENTRAL U.S. EVENT.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
THE 00Z MODEL GUIDANCE SUITE IS GENERALLY IN ABOVE AVERAGE  
AGREEMENT THROUGH MONDAY NIGHT WITH THE OVERALL SYNOPTIC SCALE  
PATTERN AND THE EVOLUTION OF THE MAIN UPPER LEVEL TROUGH/CLOSED  
LOW OVER THE ROCKIES AND SOUTHERN PLAINS. THE GFS IS STRONGER  
WITH THE CLOSED LOW BUT STILL WITHIN THE REALM OF POSSIBILITY. BY  
TUESDAY, THE GFS AND ITS ENSEMBLE MEAN ARE FARTHER NORTH ACROSS  
KANSAS, WHEREAS THE CMC/ECMWF SOLUTIONS ARE FAVORING A POSITION  
OVER THE TEXAS PANHANDLE WITH THE CLOSED LOW. BY THE END OF THE  
FORECAST PERIOD WEDNESDAY, THE 00Z ECMWF IS OUT OF PHASE ACROSS  
THE PACIFIC NORTHWEST WITH A MUCH STRONGER TROUGH PASSAGE, WHEREAS  
THE ENSEMBLE MEANS ARE FAVORED MORE OF A RIDGE AXIS.  
 
TAKING THESE FACTORS INTO ACCOUNT, THE WPC FORECAST WAS PRIMARILY  
BASED ON A MULTI-DETERMINISTIC MODEL BLEND AS A STARTING POINT  
THROUGH ABOUT MONDAY, AND THEN INCORPORATED MORE OF THE ENSEMBLE  
MEANS WHILST STILL MAINTAINING SMALLER CONTRIBUTIONS FROM THE  
ECMWF/GFS/CMC.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
THE SURFACE LOW TRACKING FROM THE OHIO VALLEY TO THE NORTHEAST ON  
SATURDAY WILL LIKELY BE ACCOMPANIED BY A SWATH OF MODERATE TO  
LOCALLY HEAVY SNOW ACROSS NORTHERN PORTIONS OF NEW ENGLAND,  
PARTICULARLY CENTRAL AND NORTHERN MAINE. ELSEWHERE, MODERATE RAIN  
IS EXPECTED FROM THE NORTHERN MID-ATLANTIC TO CENTRAL/SOUTHERN NEW  
ENGLAND FOR THE FIRST HALF OF THE WEEKEND.  
 
ATTENTION THEN TURNS TO THE PLAINS AND GULF COAST REGION AS A  
SURFACE LOW BECOMES BETTER ORGANIZED BY EARLY MONDAY AND TAPS INTO  
A SURGE OF GULF MOISTURE ACROSS TEXAS AND THE CENTRAL GULF COAST  
REGION. THE PROSPECTS FOR HEAVY RAINFALL AND SEVERE WEATHER HAVE  
INCREASED SINCE YESTERDAY, MAINLY LATER IN THE DAY MONDAY AND  
ESPECIALLY INTO TUESDAY. FLOODING RAIN COULD ALSO BE AN ISSUE AS  
MULTIPLE ROUNDS OF CONVECTION DEVELOP OVER THE SAME GENERAL AREAS.  
THE STORM PREDICTION CENTER HAS ADDITIONAL INFORMATION PERTAINING  
TO THE SEVERE WEATHER POTENTIAL.  
 
IN TERMS OF TEMPERATURES, THE EAST COAST SHOULD CONTINUE TO HAVE  
ABOVE NORMAL READINGS THIS WEEKEND AND INTO THE MIDDLE OF NEXT  
WEEK AS UPPER LEVEL RIDGING DEVELOPS AHEAD OF THE DEEP TROUGH OVER  
THE PLAINS. EVEN GREATER POSITIVE ANOMALIES ARE LIKELY ACROSS THE  
CENTRAL AND NORTHERN PLAINS BY SUNDAY AHEAD OF THE STORM SYSTEM,  
WITH HIGHS UP TO 25 DEGREES ABOVE AVERAGE, WHEREAS A RETURN TO  
SLIGHTLY BELOW AVERAGE TEMPERATURES IS EXPECTED ACROSS THE ROCKIES  
AND THE WESTERN HIGH PLAINS UNDER THE UPPER LEVEL TROUGH FOR  
MONDAY AND TUESDAY. NO MAJOR SURGES OF ARCTIC AIR ARE EXPECTED.  
 
HAMRICK  
 
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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