936  
FXUS02 KWBC 190701  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 AM EDT SUN JUN 19 2022  
 
VALID 12Z WED JUN 22 2022 - 12Z SUN JUN 26 2022  
 
...EXPANSIVE AREA OF EXCESSIVE HEAT LIKELY TO PERSIST ACROSS THE  
SOUTH INTO NEXT WEEKEND...  
 
   
..OVERVIEW
 
 
A BROAD UPPER LEVEL RIDGE CENTERED OVER THE LOWER MISSISSIPPI  
VALLEY (AND DRIFING SLOWLY WESTWARD INTO NEXT WEEKEND) WILL BE THE  
MOST PROMINENT FEATURE DURING THE MEDIUM RANGE PERIOD WITH  
WIDESPREAD EXCESSIVE HEAT EXPECTED ACROSS MUCH OF THE SOUTH. TO  
THE NORTH, EXPECT WEAK AND PROGRESSIVE SYSTEMS TO RIDE THE TOP OF  
THE RIDGE THROUGH THE CENTRAL U.S. AND MIDWEST WITH TROUGHING  
ALONG BOTH THE EAST AND WEST COASTS. MONSOONAL MOISTURE WILL  
LIKELY CONTINUE INTO AT LEAST THE MIDDLE OF THE WEEK TOO ACROSS  
THE FOUR CORNERS REGION.  
 
   
..GUIDANCE/PREDICTABILITY EVALUATION
 
 
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT ON THE OVERALL PATTERN,  
ESPECIALLY WITH RESPECT TO THE STRONG AND BROAD RIDGE ACROSS THE  
SOUTHERN U.S.. SYSTEMS THROUGH THE NORTHERN TIER SHOW TYPICAL  
DETAIL AND TIMING DIFFERENCES, MOSTLY ABLE TO BE RESOLVED FOR NOW  
WITH A GENERAL MODEL BLEND (MORE DETERMINISTIC MODELS THE FIRST  
HALF OF THE PERIOD, WITH MORE ENSEMBLES BY THE END). ONE NOTABLE  
PLACE OF UNCERTAINTY IS OFF THE EAST COAST REGARDING A CUT OFF LOW  
DRIFING SOUTHWARD, AND THEN POSSIBLY RETROGRADING BACK TOWARDS THE  
COAST BY THURSDAY OR FRIDAY. THE GFS HAS BEEN PRETTY CONSISTENT IN  
SHOWING THIS LOW LINGERING OFF THE NORTHEAST COAST AND THEN  
QUICKLY GETTING PICKED UP BY THE MAIN WESTERLY FLOW AND PUSHED  
EASTWARD. MEANWHILE, THE ECMWF, UKMET, AND CMC ALL SUPPORT  
SOMETHING LINGERING MORE OFF THE CAROLINA COASTS AND THEN  
EVENTUALLY RETROGRADING SLOWLY WESTWARD, ALTHOUGH THE CMC SEEMS  
MUCH TO FAR SOUTH AND ACTUALLY TAKES THIS FEATURE BACK TOWARDS  
FLORIDA NEXT WEEKEND. ENSEMBLE MEANS GENERALLY SUPPORT THEIR  
DETERMINISTIC COUNTERPARTS, THOUGH SIGNIFICANTLY WEAKER OWING TO  
INCREASED VARIABILITY IN INDIVIDUAL MEMBER SOLUTIONS. HOWEVER,  
GIVEN THE UNCERTAINTY, LEANING ON THE ENSEMBLE MEANS LATE PERIOD  
SEEMED PRUDENT AT THIS POINT FOR THIS FEATURE.  
 
   
..SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
ANOMALOUSLY HIGH MONSOONAL MOISTURE FOR THIS TIME OF YEAR, LIKELY  
TIED AT LEAST IN PART TO EASTERN PACIFIC TROPICAL SYSTEMS, WILL  
CONTINUE STREAMING INTO THE FOUR CORNERS STATES AT LEAST THROUGH  
MIDWEEK AND POSSIBLY LATER INTO THE WEEK AS WELL. LOCALLY HEAVY TO  
EXCESSIVE RAINFALL IS POSSIBLE, PARTICULARLY OVER SENSITIVE BURN  
SCAR AREAS AND CONSIDERING THE MULTIPLE DAY REPEATING NATURE OF  
THIS ACTIVITY. A SHOWERY/STORMY PATTERN COULD ALSO SET UP THROUGH  
FRIDAY IN CENTRAL PARTS OF THE PLAINS AND MISSISSIPPI VALLEY AS A  
FRONT BECOMES ALIGNED WEST-EAST, WITH SOME POTENTIAL FOR RAIN AND  
STORMS TO TRAIN IN SOME AREAS. FARTHER EAST, A ROUND OF RAIN IS  
FORECAST NEAR A WARM FRONT IN THE NORTHEAST WITH RAIN FORECAST TO  
SPREAD INTO THE MID-ATLANTIC BY WEDNESDAY AND BEYOND. HOW MUCH  
RAIN THEN LINGERS ACROSS THE EAST COAST WILL BE DEPENDENT ON THE  
AFOREMENTIONED UPPER LOW/TROUGH FEATURE'S EXISTENCE AND TRACK. A  
SURFACE LOW/COLD FRONT THROUGH THE UPPER MIDWEST NEXT WEEKEND MAY  
ALSO BE ACCOMPANIED BY SHOWERS AND STORMS.  
 
BIG WESTHER STORY THOUGH CONTINUES TO BE THE BROAD RIDGE OVER THE  
SOUTHERN U.S. WITH ANOMALOUSLY WARM TEMPERATURES ACROSS THE PLAINS  
AND EASTWARD NEXT WEEK. THE GREATEST ANOMALIES (GENERALLY 10-15+  
ABOVE NORMAL) WILL SHIFT INTO THE SOUTH WEDNESDAY-FRIDAY, WITH  
HIGH TEMPERATURES IN THE MID-UPPER 90S AND LOW 100S AND LOWS WELL  
INTO THE 70S MEANING LITTLE RELIEF OVERNIGHT IN MANY AREAS. DAILY  
RECORD HIGH MAX AND MIN TEMPERATURES ARE LIKELY TO BE WIDESPREAD.  
RELATIVELY COOLER TEMPERATURES WITH WELL BELOW NORMAL HIGHS ARE  
FORECAST PARTICULARLY FOR NEW MEXICO GIVEN THE MONSOONAL CLOUDS  
AND RAIN COVERAGE, WHILE NEAR NORMAL TEMPERATURES STRETCH THROUGH  
THE ROCKIES AND WEST COAST STATES.  
 
SANTORELLI  
 
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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