487  
FXUS02 KWBC 121741  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1240 PM EST SAT MAR 12 2022  
 
VALID 12Z TUE MAR 15 2022 - 12Z SAT MAR 19 2022  
   
..OVERVIEW
 
 
A FEW WAVES CROSS THE LOWER 48 IN A PROGRESSIVE PATTERN THAT IS  
ACTIVE FOR THE PACIFIC NORTHWEST. A LEADING SOUTHERN STREAM SYSTEM  
WILL SHIFT EAST ACROSS THE DEEP SOUTH/GULF COAST TUESDAY INTO  
WEDNESDAY BEFORE LIFTING NORTHEAST OVER THE CAROLINAS AND OFF THE  
SOUTHERN MID-ATLANTIC COAST THURSDAY. THE NEXT UPPER TROUGH WILL  
PUSH INLAND OVER THE PACIFIC NORTHWEST TUESDAY AND DIG A BIT AS IT  
SHIFTS EAST OVER THE SOUTHERN INTERMOUNTAIN WEST WEDNESDAY AND THE  
SOUTHERN ROCKIES WEDNESDAY NIGHT BEFORE TURNING EAST-NORTHEAST AND  
TO THE MIDWEST/GREAT LAKES THROUGH FRIDAY. THIS SHOULD MAKE FOR A  
RETURN TO WET WEATHER FOR THE SOUTH-CENTRAL AT THE END OF THE WORK  
WEEK AND THE MIDWEST/NORTHEAST NEXT WEEKEND.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
THE 00Z ECMWF/UKMET/CMC AND 06Z GFS ARE IN EXCELLENT AGREEMENT  
WITH THE STRENGTH AND TIMING OF THE LEADING SOUTHERN STREAM SYSTEM  
THROUGH WEDNESDAY BEFORE THE 06Z GFS (AND NOW THE 12Z GFS) BECOMES  
MORE PROGRESSIVE WITH THE EXIT OFF CAPE HATTERAS WEDNESDAY NIGHT.  
THE GFS REMAINS FARTHER NORTH WITH THE NEXT WAVE OVER THE SOUTHERN  
ROCKIES WEDNESDAY NIGHT AND THEN IS MORE UNIFIED WITH THE NORTHERN  
AND SOUTHERN STREAM TROUGHS AS THAT WAVE SHIFTS TO THE MIDWEST  
WHILE THE 00Z ECMWF/CMC HAVE NOTABLE SEPARATION. THEREFORE, A  
BLEND OF THE FOUR MAIN GLOBAL MODELS FOR DAYS 3 AND 4 BECOMES MORE  
RELIANT ON ENSEMBLE MEANS ON DAY 5 AND ARE MAJORITY ENSEMBLE MEANS  
FOR 6/7.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
AMPLE GULF MOISTURE WILL BE DRAWN AHEAD OF THE DEEP SOUTH SYSTEM  
TUESDAY INTO WEDNESDAY, WHICH SHOULD COMBINE WITH SUFFICIENT  
INSTABILITY TO BRING WIDESPREAD THUNDERSTORMS CAPABLE OF PRODUCING  
HEAVY RAINFALL AND LOCALLY EXCESSIVE RAIN, ESPECIALLY OVER NORTH  
FLORIDA WHICH IS AN AREA THAT RECEIVED HEAVY RAIN OVER THE PAST  
DAY. PRECIPITATION OVER THE INTERMOUNTAIN WEST TUESDAY  
NIGHT/WEDNESDAY WILL WEAKEN AS PACIFIC MOISTURE IS CUT OFF FROM  
THE WAVE. HOWEVER, AS THE WAVE AMPLIFIES OVER THE SOUTHERN ROCKIES  
A MODERATE RETURN OF MOISTURE CAN BE EXPECTED FROM THE GULF OF  
MEXICO WHICH WILL AN EMERGING AND EXPANDING AREA OF RAIN AND  
THUNDERSTORMS FROM THE SOUTH-CENTRAL TO EAST-CENTRAL U.S. THURSDAY  
THROUGH SATURDAY, ALBEIT IN A PATTERN WITH INCREASING FORECAST  
SPREAD WITH THE PROGRESSION AND STRENGTH DETERMINED BY THE  
AFOREMENTIONED INTERACTION OF THE NORTHERN AND SOUTHERN STREAM  
COMPONENTS.  
 
RIDGING BETWEEN THE SOUTHEAST AND WEST SYSTEMS WILL BRING  
TEMPERATURES 10 TO 20 DEGREES ABOVE NORMAL TO THE CENTRAL/NORTHERN  
PLAINS TUESDAY. THIS WARM AIRMASS SHIFTS EAST, REACHING THE  
INTERIOR NORTHEAST BY FRIDAY.  
 
JACKSON  
 
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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