894  
FXUS02 KWBC 250658  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
258 AM EDT WED MAY 25 2022  
 
VALID 12Z SAT MAY 28 2022 - 12Z WED JUN 1 2022  
   
..WEATHER PATTERN OVERVIEW
 
 
AN UPPER TROUGH WITH POSSIBLE EMBEDDED CLOSED LOW WILL BE CROSSING  
THE EASTERN U.S. LATE THIS WEEK INTO THE WEEKEND, WITH SOME  
UNCERTAINTY OVER HOW QUICKLY IT AND THE ASSOCIATED SURFACE  
WAVE/FRONTAL SYSTEM EXITS THE EAST COAST. MEANWHILE, A SHORTWAVE  
REACHING THE NORTHWESTERN U.S. BY FRIDAY WILL BE AT THE LEADING  
EDGE OF A LARGER SCALE TROUGH THAT SHOULD AMPLIFY OVER THE WEST  
DURING THE WEEKEND AND INTO EARLY NEXT WEEK. A STRONG RIDGE WILL  
BUILD OVER AN INCREASING PORTION OF THE EASTERN HALF OF THE  
COUNTRY GOING INTO THE BEGINNING OF JUNE AS THE WESTERN TROUGH  
DEEPENS, WITH THE POTENTIAL FOR A BLOCKY PATTERN TO DEVELOP.  
   
..MODEL GUIDANCE AND PREFERENCES
 
 
THE 00Z MODEL GUIDANCE SUITE IS NOW FAVORING A MORE AMPLIFIED  
TROUGH SOLUTION ACROSS THE EAST COAST REGION FOR SATURDAY, WITH  
BOTH THE GFS AND CMC FAVORING A BIT OF A CLOSED LOW. OUT WEST,  
THE GUIDANCE SHOWS GOOD TIMING AGREEMENT ON THE INITIAL SHORTWAVE  
INTO THE WEST LATE THIS WEEK, AND THE CMC IS SLIGHTLY SLOWER WITH  
THE SECOND IMPULSE, WHICH WILL REINFORCE THE OVERALL SYNOPTIC  
SCALE TROUGH THAT DEVELOPS ACROSS THE WESTERN U.S. BY SUNDAY AND  
BEYOND. GOING INTO TUESDAY, THE GFS GETS STRONGER AND FASTER WITH  
THE TROUGH OVER THE ROCKIES AND LIFTING IT OUT ACROSS THE WESTERN  
HIGH PLAINS. THERE IS VERY GOOD MODEL AGREEMENT ON THE BUILDING  
UPPER RIDGE OVER THE OHIO VALLEY. THE WPC FORECAST TRENDED MORE  
TOWARDS THE ENSEMBLE MEANS FOR THE SECOND HALF OF THE PERIOD TO  
ACCOUNT FOR THIS UNCERTAINTY, WHILST STILL MAINTAINING SOME OF THE  
DETERMINISTIC CMC/ECMWF/GFS, AND GENERALLY SHOWS GOOD CONTINUITY  
WITH THE PREVIOUS WPC FORECAST AS WELL.  
   
..SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
WITH RAINFALL DIMINISHING IN COVERAGE/INTENSITY OVER THE EAST BY  
THE WEEKEND, THE MAIN FOCUS FOR PRECIPITATION WILL EXTEND FROM THE  
NORTHWEST THROUGH THE NORTHERN-CENTRAL PLAINS INTO THE WESTERN  
GREAT LAKES. SHOWERS AND STORMS WILL INITIALLY DEVELOP ACROSS THE  
NORTHERN PLAINS AND UPPER MIDWEST IN RESPONSE TO A DEVELOPING LOW  
PRESSURE AND FRONTAL BOUNDARY OVER THE NORTH-CENTRAL U.S., WHILE  
SOME PRECIPITATION EXTENDS BACK INTO THE NORTHERN ROCKIES AND  
VICINITY. ANOTHER SHORTWAVE REACHING THE PACIFIC NORTHWEST AROUND  
SATURDAY COULD BRING AN EPISODE OF ENHANCED PRECIPITATION TO PARTS  
OF THE REGION, FOLLOWED BY THIS MOISTURE STREAMING ACROSS THE  
ROCKIES AND INTERACTING WITH THE WAVY FRONTAL SYSTEM SET UP OVER  
THE PLAINS. LATE SEASON SNOW FOR THE HIGHER TERRAIN OF THE  
NORTHERN ROCKIES IS LOOKING INCREASINGLY LIKELY, WITH POTENTIALLY  
OVER A FOOT OF ACCUMULATION ABOVE 8000 FEET ELEVATION. THERE IS  
ALSO THE POTENTIAL FOR HEAVY RAINFALL ACROSS PORTIONS OF THE  
DAKOTAS BY EARLY NEXT WEEK BEHIND THE FRONT WITH MOIST UPSLOPE  
FLOW, WITH PERHAPS 1 TO 3 INCHES FOR SOME AREAS.  
 
TEMPERATURES WILL BE QUITE WARM ACROSS THE CENTRAL AND SOUTHERN  
PLAINS FOR THE WEEKEND WITH HIGHS REACHING WELL INTO THE 90S FROM  
SOUTHERN NEBRASKA TO THE GULF COAST, AND SOME LOW-MID 100S ACROSS  
WESTERN TEXAS WHICH COULD CHALLENGE SOME DAILY RECORDS. THE HEAT  
THEN BUILDS EASTWARD TO INCLUDE THE OHIO VALLEY AND EVENTUALLY THE  
EAST COAST GOING INTO EARLY NEXT WEEK, COMPLIMENTS OF THE BUILDING  
UPPER RIDGE AND SOUTHERLY FLOW AHEAD OF THE STORM SYSTEM OVER THE  
PLAINS. WELL BELOW NORMAL TEMPERATURES WILL LIKELY ENCOMPASS  
AREAS FROM THE PACIFIC NORTHWEST TO THE NORTHERN ROCKIES AND  
NORTHERN PLAINS AS THE UPPER TROUGH MOVES IN BEHIND THE COLD  
FRONT, WITH HIGHS UP TO 20 DEGREES BELOW LATE MAY AVERAGES.  
 
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  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION, EXPERIMENTAL EXCESSIVE RAINFALL  
OUTLOOK, WINTER WEATHER OUTLOOK PROBABILITIES AND HEAT INDICES ARE  
AT:  
 
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/#PAGE=ERO  
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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