697  
FXUS02 KWBC 250712  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
311 AM EDT FRI MAR 25 2022  
 
VALID 12Z MON MAR 28 2022 - 12Z FRI APR 01 2022  
 
...EARLY NEXT WEEK WET PATTERN FOR SOUTHERN CALIFORNIA SPREADS  
EASTWARD AND SIGNIFICANTLY EXPANDS/INTENSIFIES OVER THE  
EAST-CENTRAL U.S. MID-LATER NEXT WEEK TO INCLUDE WRAPPING NORTHERN  
PERIPHERY SNOW/ICE...  
   
..OVERVIEW
 
 
AN AMPLIFIED UPPER TROUGH AND LINGERING WINTRY WEATHER WILL EXIT  
THE NORTHEASTERN U.S. BY EARLY NEXT WEEK, LEAVING A COOLED AIRMASS  
DOWN ACROSS THE NORTH-CENTRAL THROUGH EASTERN STATES. THE MAIN  
WEATHER FOCUS ACROSS THE NATION WILL SHIFT TO THE WEST AS A STRONG  
UPPER TROUGH AND EMBEDDED CLOSED LOW PROGRESS INTO/THROUGH THE  
SOUTHWESTERN STATES EARLY NEXT WEEK BEFORE LIFTING ACROSS THE  
SOUTH-CENTRAL ROCKIES/PLAINS MIDWEEK. THERE IS THEN A GROWING  
GUIDANCE TREND TO INCREASE PHASING WITH NORTHERN STREAM TROUGH  
ENERGIES OVER THE EAST-CENTRAL U.S. INTO NEXT THURSDAY/FRIDAY THAT  
WOULD ALSO PROMOTE MORE ORGANIZED SURFACE LOW AND FRONTAL  
DEVELOPMENT AND STRENGTH. OVERALL, THIS WILL FAVOR RATHER  
UNSETTLED AND WET PATTERN FROM CA AND THE SOUTHWEST TO THE  
SOUTH-CENTRAL ROCKIES EARLY NEXT WEEK (INCLUDING MOUNTAIN SNOWS)  
THAT WILL EMERGE, EXPAND IN MAGNITUDE AND SPREAD FROM PLAINS TO  
THE EAST-CENTRAL AND EASTERN/SOUTHEASTERN U.S. LATER NEXT WEEK AS  
GULF MOISUTRE INCREASING FEEDS INTO THE SYSTEM.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
A COMPOSITE OF REASONABLY WELL CLUSTERED GUIDANCE FROM THE 18 UTC  
GFS AND 12 UTC ECMWF/UKMET/CANADIAN SEEMS TO OFFER A GOOD FORECAST  
BASIS MONDAY INTO WEDNESDAY. FORECAST SPREAD INCREASES BY LATER  
WEDNESDAY INTO NEXT FRIDAY, BUT HAS IMPROVED A BIT FROM YESTERDAY.  
OF THE ENSEMBLE SYSTEMS, THE 12 UTC ECMWF ENSEMBLE MEAN PROVIDES  
THE MOST REASONABLE MIDPOINT POSITION/PHASING SOLUTION BETWEEN  
MORE VARIED MODELS ARE THESE LONGER TIME FRAMES. THE ECMWF  
ENSEMBLE MEAN ALSO FAVORS MORE RENEWED UPPER TROUGH DIGGING THAN  
THE GEFS AND ESPECIALLY THE FLATTER GFS BY THEN BACK INTO THE  
WEST. THIS SEEMS REASONABLE CONSIDERING UPSTREAM FLOW AMPITUDE AND  
00 UTC GUIDANCE HAS TRENDED OR MAINTAINED THIS SCENARIO. THE WPC  
MEDIUM RANGE PRODUCT SUITE WAS PRIMARILY DERIVED FROM PREFERRED  
GUIDANCE ALONG WITH THE 01 UTC NATIONAL BLEND OF MODELS. THIS  
SOLUTION SEEMS IN LINE WITH LATEST GUIDANCE TRENDS AND MAINTAINS  
GOOD PRODUCT CONTINUITY.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
MODEL GUIDANCE SHOWS THE HEAVIEST RAIN TOTALS FOR SOUTHERN  
CALIFORNIA INTO 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/EASTERN PLAINS AND MID-LOWER MISSISSIPPI VALLEY TUESDAY  
AND WEDNESDAY. MEANWHILE ON THE NORTHERN SIDE OF THE PRECIPITATION  
SHIELD, A WINTRY MIX AND ACCUMULATING WRAPPING SNOWS ARE POSSIBLE  
FOR THE NORTHERN TIER, MAINLY FROM THE UPPER MIDWEST THE THE GREAT  
LAKES AND NORTHERN TIER OF THE NORTHEAST. RAINFALL COULD REMAIN  
HEAVY THROUGH THE EAST AND ESPECIALLLY THE SOUTHEAST LATER NEXT  
WEEK.  
 
SCHICHTEL  
 
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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