765  
FXUS02 KWBC 131903  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
302 PM EDT SUN MAR 13 2022  
 
VALID 12Z WED MAR 16 2022 - 12Z SUN MAR 20 2022  
   
..OVERVIEW
 
 
SEVERAL SYSTEMS WILL QUICKLY PASS THROUGH THE LOWER 48 DURING THE  
EXTENDED PERIOD WITHIN THE RELATIVELY PROGRESSIVE AND GRADUAL  
AMPLIFYING FLOW. THE INITIAL SYSTEM OVER THE SOUTHEAST WILL TRACK  
UP THE CAROLINA COAST BEFORE EXITING INTO THE ATLANTIC. LOW  
PRESSURE ORGANIZING THURSDAY OVER THE SOUTHERN PLAINS IS EXPECTED  
TO LIFT NORTHWARD 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
 
 
THE LATEST GUIDANCE IS FAIRLY CLUSTERED WITH THE GRADUALLY  
AMPLIFICATION OF THE FLOW OVER THE LOWER 48 THROUGH THE FIRST HALF  
OF THE PERIOD. SPREAD DOES BEGIN TO INCREASE WITH THE TIMING AND  
AMPLIFICATION BY THE END OF THE WEEKEND AND INTO NEXT WEEK. A  
GENERAL BLEND OF THE ECWMF/GFS/CMC/UKMET WAS APPLIED INITIALLY AND  
CONTINUED TO PROVIDE PREDICTABILITY WITH THE MAIN SYNOPTIC  
FEATURES OVER THE CONUS.  
 
AS PREVIOUSLY NOTE, THE GFS IS PERSISTENT ON REMAINING THE  
FASTER/PROGRESSIVE SOLUTION WITHIN THE CLUSTER AND THIS IS CAUSING  
THE QPF PLACEMENT TO BE FURTHER NORTH/EAST ESPECIALLY ACROSS THE  
PLAINS AND SOUTHEAST U.S. WITH THE FIRST SYSTEM THAT PASSES  
THROUGH AND WITH THE ONE OVER THE PLAINS. FOR DAY 6 AND 7, THE  
OVERALL FLOW PATTERN WILL AMPLIFY, FAVORING DEEP TROUGHING OVER  
THE WEST AND THE EAST. GIVEN THE DEGREE OF SPREAD, THE ECWMF  
ENSEMBLE MEAN AND THE GEFS MEAN WERE INCLUDED BEYOND DAY 5  
INCREASING IN ITS WEIGHTING TO 40 PERCENT BY THE END OF THE  
PERIOD.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
WIDESPREAD SHOWERS AND THUNDERSTORM ARE EXPECTED ACROSS THE GULF  
COAST STATES AND SOUTHEAST AS A SLOW-MOVING SYSTEM TRACKS THROUGH  
WEDNESDAY AND THURSDAY. THERE MAY BE ELEVATED RISK FOR EXCESSIVE  
RAINFALL ALONG THE COASTLINE WHERE THERE WILL BE BETTER ALIGNMENT  
OF LARGE SCALE LIFT AND MOISTURE ADVECTION. 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. THE EXACT  
DETAILS ON ANY SIGNIFICANT ACCUMULATIONS ARE TOO UNCERTAIN AT THIS  
TIME.  
 
ANOTHER LARGE SCALE AND POTENTIALLY STRONG SYSTEM IS EXPECTED TO  
PASS THROUGH THE WEST 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.  
 
CAMPBELL  
 
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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