959  
FXUS02 KWBC 130641  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
140 AM EST SUN MAR 13 2022  
 
VALID 12Z WED MAR 16 2022 - 12Z SUN MAR 20 2022  
   
..OVERVIEW
 
 
A RELATIVELY PROGRESSIVE AND GRADUALLY MORE AMPLIFIED FLOW PATTERN  
ACROSS THE LOWER 48 DURING THE PERIOD WILL ALLOW SEVERAL STORM  
SYSTEMS TO MOVE QUICKLY THROUGH THE CONUS. TO START, A SOUTHEAST  
COASTAL SYSTEM WILL TRACK UP THE CAROLINA COAST MID-WEEK BEFORE  
TRACKING OFFSHORE. LOW PRESSURE ORGANIZING IN THE SOUTHERN PLAINS  
THURSDAY IS LIKELY TO LIFT THROUGH THE CENTRAL U.S. FRIDAY INTO  
SATURDAY BRINGING ACTIVE WEATHER TO CENTRAL/EASTERN U.S. WHILE THE  
PACIFIC NORTHWEST REMAINS UNSETTLED WITH WIDESPREAD PRECIPITATION  
LIKELY RETURNING NEXT WEEKEND. NO SIGNIFICANT COLD AIR OUTBREAKS  
ARE ANTICIPATED AND TEMPERATURES WILL OSCILLATE BETWEEN NORMAL AND  
MUCH ABOVE NORMAL AHEAD OF THE VARIOUS WAVES OF LOW PRESSURE.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
THROUGH DAY 5, THE DETERMINISTIC GUIDANCE OFFERED VERY GOOD  
AGREEMENT AND PREDICTABILITY WITH THE MAIN SYNOPTIC FEATURES OVER  
THE CONUS. FOR THE SOUTHEAST SYSTEM EARLY ON, THE GFS IS A  
SLIGHTLY FASTER/PROGRESSIVE SOLUTION WITH A MORE NORTHERLY LOW  
TRACK, WHICH SEEMS TO BE WHERE GUIDANCE HAS TRENDED OVER THE LAST  
SEVERAL CYCLES. THE SHORTWAVE TROUGH COMING OUT INTO THE PLAINS  
DAY 4/5 LOOKS TO HAVE THE TYPICAL TIMING BIASES, WHERE THE GFS IS  
ON THE FASTER SIDE BUT OTHERWISE THE DETERMINISTIC MODELS SHOW  
FAIRLY AGREEABLE AMPLITUDE. BY DAY 6/7, THE FLOW PATTERN IS  
TRENDING MORE AMPLIFIED OVER THE CONUS, WITH DEEP TROUGHING  
BECOMING MORE FAVORED OVER THE WESTERN U.S. AND ALSO OVER THE  
EASTERN U.S.. BY THIS POINT, THE DETERMINISTIC GUIDANCE VARIES A  
LOT, WITH THE CMC VS. GFS/ECMWF NEARLY OUT OF PHASE. FOR NOW, THE  
DETERMINISTIC GFS/ECMWF AND ITS ENSEMBLE MEANS HAVE GOOD SUPPORT  
SO THE WPC BLEND DAYS 5-7 WAS COMPRISED OF THE DETERMINISTIC  
GFS/ECMWF AND GEFS/ECENS, REMOVING THE CMC/CMCE WITH THE MAJORITY  
OF THE BLENDED WEIGHTS TOWARD THE ENSEMBLE MEANS.  
 
   
..WEATHER HIGHLIGHTS/THREATS
 
 
THE SLOW MOVING SOUTHERN STREAM SYSTEM TRACKING ALONG THE GULF  
COAST AND SOUTHEAST WILL DRAW UP PLENTY OF MOISTURE AND COMBINED  
WITH SUFFICIENT INSTABILITY AND FORCING SHOULD BRING WIDESPREAD  
THUNDERSTORMS WEDNESDAY-THURSDAY. SOME THREAT OF LOCALLY HEAVY  
RAINFALL EXISTS ALONG THE COAST WHERE BETTER INGREDIENTS LOOK TO  
EXIST. THE NEXT WAVE OF LOW PRESSURE LIFTING THROUGH THE CENTRAL  
U.S. INTO THE GREAT LAKES LATE THURSDAY INTO SATURDAY WILL WORK  
WITH INCREASING GULF MOISTURE AND LARGE SCALE LIFT. THIS SHOULD  
RESULT IN AN EXPANDING AREA OF SHOWERS AND THUNDERSTORMS WITH SOME  
POTENTIAL OF WINTER WEATHER ON THE COLD/NORTHWEST SIDE OF THE  
SYSTEM, THOUGH DETAILS ON ANY SIGNIFICANT ACCUMULATIONS ARE TOO  
UNCERTAIN AT THIS TIME. FINALLY, BY NEXT WEEKEND, ANOTHER LARGE  
SCALE AND POTENTIALLY STRONG SYSTEM WILL MOVE INTO THE WESTERN  
U.S. BRINGING BENEFICIAL RAINFALL TO THE PACIFIC NORTHWEST AND  
PERHAPS AS FAR SOUTH AS CENTRAL CALIFORNIA. NO MAJOR ARCTIC AIR  
INTRUSIONS ARE EXPECTED THROUGH THE PERIOD AND TEMPERATURES WILL  
GENERALLY TREND NORMAL TO ABOVE NORMAL WITH THE GREATEST  
DEPARTURES FROM NORMAL EXPECTED ALONG/AHEAD OF THE VARIOUS WAVES  
OF LOW PRESSURE MOVING THROUGH THE FLOW.  
 
TAYLOR  
 
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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