898  
FXUS02 KWBC 231859  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
259 PM EDT MON MAY 23 2022  
 
VALID 12Z THU MAY 26 2022 - 12Z MON MAY 30 2022  
   
..WEATHER PATTERN OVERVIEW
 
 
A LARGE SCALE UPPER TROUGH (WITH POSSIBLE EMBEDDED CLOSED LOW)  
WILL BE CROSSING THE EAST-CENTRAL U.S. THROUGH THE END OF THE WORK  
WEEK, AND THIS WILL SUSTAIN A SURFACE COLD FRONT THAT WILL TRACK  
EASTWARD AND SHOULD EXIT THE EAST COAST BY THE WEEKEND. MEANWHILE,  
ANOTHER TROUGH ENTERS THE NORTHWESTERN U.S. BY THE END OF THE WEEK  
WITH A BRIEF UPPER RIDGE AHEAD OF IT ACROSS THE INTERMOUNTAIN WEST  
AND ROCKIES. MODELS SUGGEST THIS TROUGH WILL DEEPEN AS IT CROSSES  
THE WEST THIS WEEKEND TO SPUR SURFACE CYCLOGENESIS ACROSS THE  
NORTHERN PLAINS THIS WEEKEND. IN RESPONSE TO THE DIGGING UPPER  
TROUGH, AN UPPER RIDGE SHOULD BUILD ACROSS THE EASTERN U.S. ALONG  
WITH WARMER TEMPERATURES.  
   
..MODEL GUIDANCE AND PREFERENCES
 
 
THE 00Z SUITE OF MODEL GUIDANCE HAS GENERALLY TRENDED SLOWER AND  
MORE AMPLIFIED WITH THE DEEP TROUGH THROUGH THE EASTERN THIRD OF  
THE NATION AS THE PERIOD BEGINS WITH INDICATIONS OF A CLOSED LOW  
OVER INTO THE OHIO VALLEY/MID-ATLANTIC AROUND FRIDAY-SATURDAY. THE  
EXCEPTION TO THIS IS THE 00Z/12Z ECMWF WHICH CONTINUES TO BE MUCH  
QUICKER AND WEAKER, ALLOWING FOR RIDGING TO BUILD IN MUCH FASTER  
BEHIND EARLY NEXT WEEK. THE TIMING IN THE ENSEMBLE MEANS GENERAL  
FOLLOW WITH THEIR DETERMINISTIC COUNTERPARTS (ALBEIT WEAKER) SO  
THERE CONTINUES TO BE A LOT OF UNCERTAINTY SURROUNDING THIS  
FEATURE. GIVEN THE TRENDS THOUGH, THE WPC PROGS DO DEPICT A  
SLOWER/MORE AMPLIFIED SYSTEM COMPARED TO PREVIOUS WPC CONTINUITY,  
WITH A PROXY CLOSEST TO THE 00Z/12Z CMC (WHICH IS A NICE MIDDLE  
GROUND BETWEEN THE STRONGER GFS AND THE WEAKER ECMWF).  
 
OUT WEST, THE GUIDANCE SHOWS GOOD TIMING AGREEMENT ON THE INITIAL  
SHORTWAVE INTO THE WEST LATE THIS WEEK, BUT DIFFER WITH THE  
EVOLUTION INTO THE WEEKEND. THE CMC (AND UKMET THROUGH DAY 5) ARE  
FASTER AND STRONGER WITH THIS LEADING SHORTWAVE DEVELOPING A  
CLOSED LOW OVER SOUTH-CENTRAL CANADA BY SUNDAY. MEANWHILE, THE GFS  
AND ECMWF AREN'T AS STRONG WITH THIS SHORTWAVE AS IT CROSSES THE  
WEST, INSTEAD WANTING TO DEVELOP AND DEEPEN THE NEXT SHORTWAVE  
INTO THE COAST AROUND SUNDAY. THE WPC FORECAST TRENDED TOWARDS THE  
ENSEMBLE MEANS THE SECOND HALF OF THE PERIOD TO ACCOUNT FOR THIS  
UNCERTAINTY AND GENERALLY SHOWS GOOD CONTINUITY WITH THE PREVIOUS  
WPC FORECAST AS WELL.  
   
..SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
PERIODS OF HEAVY RAINFALL WILL CONTINUE TO MAKE WEATHER HEADLINES  
GOING INTO THURSDAY AND FRIDAY ACROSS PORTIONS OF THE EASTERN U.S.  
ALONG AND AHEAD OF THE COLD FRONT, WITH HEAVY TO EXCESSIVE  
RAINFALL POSSIBLE IN SOME AREAS PARTICULARLY ACROSS THE SOUTHEAST.  
A SLIGHT RISK AREA IN THE DAY 4 EXPERIMENTAL EXCESSIVE RAINFALL  
OUTLOOK IS HIGHLIGHTED FROM FAR NORTHERN GEORGIA TO SOUTHWESTERN  
NORTH CAROLINA WHERE THE BEST OROGRAPHIC FORCING WILL BE PRESENT  
IN A MOIST ENVIRONMENT. LATE WEEK INTO NEXT WEEKEND, THE FRONT  
MOVING INLAND ACROSS THE NORTHWESTERN U.S. AND EVENTUALLY THE  
CENTRAL/NORTHERN PLAINS IS EXPECTED TO BRING SOME SHOWERS AND  
THUNDERSTORMS (AND PERHAPS SOME LATE MAY MOUNTAIN SNOWS) FROM THE  
PACIFIC NORTHWEST TO THE NORTHERN ROCKIES. STORMS SHOULD EMERGE  
OVER THE CENTRAL/NORTHERN PLAINS TO THE UPPER MIDWEST NEXT WEEKEND  
AS THE LOW PROGRESSES EASTWARD.  
 
IN TERMS OF TEMPERATURES, PLEASANTLY COOL CONDITIONS CAN BE  
EXPECTED ACROSS MUCH OF THE MIDWEST AND GREAT LAKES REGION IN THE  
WAKE OF THE COLD FRONT FOR THE END OF THE WEEK, FOLLOWED BY A  
WARM-UP WITH ABOVE NORMAL HIGHS RETURNING BY THE WEEKEND ACROSS  
MUCH OF THE PLAINS, WITH 90S LIKELY AS FAR NORTH AS CENTRAL  
NEBRASKA, AND EVEN SOME LOW 100S FOR PORTIONS OF WESTERN TEXAS.  
HOT WEATHER IS ALSO EXPECTED FOR THE LOWER ELEVATIONS OF THE  
DESERT SOUTHWEST FOR THURSDAY THROUGH THE WEEKEND AS AN UPPER  
LEVEL RIDGE IS EXPECTED TO BE IN PLACE, ALTHOUGH A COOLING TREND  
WILL COMMENCE FOR THE INLAND VALLEYS OF CENTRAL CALIFORNIA.  
ELSEWHERE, EXPECT HIGHS TO GENERALLY BE WITHIN 5 DEGREES OF  
CLIMATOLOGICAL AVERAGES ACROSS MOST OF THE EASTERN U.S. THROUGH  
SATURDAY, ALTHOUGH OVERNIGHT LOWS COULD END UP BEING MILDER THAN  
USUAL OWING TO MORE CLOUD COVER AND HUMIDITY. HEAT RETURNS TO MUCH  
OF THE NORTHEAST U.S. AND OHIO VALLEY BY EARLY NEXT WEEK AS THE  
UPPER RIDGE BUILDS BACK IN.  
 
SANTORELLI/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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