710  
FXUS02 KWBC 231902  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
301 PM EDT THU JUN 23 2022  
 
VALID 12Z SUN JUN 26 2022 - 12Z THU JUN 30 2022  
 
...HEAVY TO EXCESSIVE RAINFALL THREAT ACROSS PARTS OF THE SOUTHERN  
ROCKIES THIS WEEKEND WITH EXCESSIVE HEAT ACROSS THE SOUTH AND  
NORTHWEST MODERATING BY EARLY NEXT WEEK...  
 
   
..OVERVIEW
 
 
A BROAD UPPER LEVEL RIDGE OVER THE SOUTHERN HALF OF THE CONUS WILL  
BE IN PLACE THROUGH MUCH OF THE MEDIUM RANGE PERIOD, FORCING STORM  
TRACKS THROUGH THE NORTHERN TIER. A VIGOROUS SHORTWAVE THROUGH THE  
UPPER MIDWEST/GREAT LAKES WILL AMPLIFY SOME AS IT MOVES INTO THE  
MID-ATLANTIC AND THE NORTHEAST EARLY NEXT WEEK. BEHIND THIS,  
AMPLIFIED RIDGING WILL BUILD OVER THE NORTHWEST U.S., AND SLIDE  
INTO THE NORTHERN PLAINS AS A CLOSED LOW/UPPER TROUGH SETTLES OVER  
THE PACIFIC NORTHWEST BY AROUND NEXT WEDNESDAY. MEANWHILE,  
MONSOONAL MOISTURE WILL CONTINUE TO PERSIST INTO THE FOUR CORNERS  
REGION THROUGH MUCH OF THE PERIOD, THOUGH THE BEST POTENTIAL FOR  
HEAVIER TO EXCESSIVE RAINS WILL BE ACROSS THE SOUTHERN HALF OF THE  
ROCKIES THIS WEEKEND.  
 
   
..GUIDANCE/PREDICTABILITY EVALUATION
 
 
ROLLING WAVES OF LOW PRESSURE ALONG THE NORTHERN TIER STATES AND A  
STAUNCH SOUTHERN RIDGE ARE CAPTURED WELL BY A GENERAL MODEL BLEND  
(GMB) THROUGH DAY 4. A BLEND OF BOTH DETERMINISTICS AND  
PROBABILISTIC MODELS ARE UTILIZED ON DAY 5 BEFORE A PREDOMINANTLY  
ENSEMBLE MEAN BLEND IS UTILIZED TO DEPICT THE SYNOPTIC FLOW  
THROUGH THE REST OF THE PERIOD. ON DAYS 3 AND 4 A GMB OF THE 00Z  
EC/CMC/UK AND 06Z GFS WERE USED TO DEPICT THE UPPER TROUGH AS IT  
GLIDES ACROSS THE UPPER MIDWEST/GREAT LAKES. DIFFERENCES BETWEEN  
THE GMB WITH RESPECT TO THE TIMING/INTENSITY OF AN APPROACHING  
UPPER-LEVEL LOW PROMPTED THE INTRODUCTION OF THE 00Z GFS/ECE AND  
06Z GEFS. THE 00Z GFS/UKMET WERE REPLACED BY THE 00Z CMCE ON DAY 6  
TO ALIGN MORE WITH THE 00Z ECE AND 06Z GFS/GEFS. THE DAY 7 PATTERN  
AND UNCERTAINTY WITH RESPECT TO AN UPPER LEVEL SHORTWAVE MAKING  
ITS WAY INTO THE PACIFIC NORTHWEST IS CAPTURED BEST BY THE  
ENSEMBLE MEANS.  
 
   
..SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
ANOMALOUSLY HIGH MONSOONAL MOISTURE FOR THIS TIME OF YEAR, LIKELY  
TIED AT LEAST IN PART TO TROPICAL STORM CELIA IN THE EAST PACIFIC,  
WILL CONTINUE STREAMING INTO THE FOUR CORNERS STATES INTO EARLY  
NEXT WEEK. LOCALLY HEAVY TO EXCESSIVE RAINFALL WILL BE POSSIBLE  
EACH DAY, PARTICULARLY OVER SENSITIVE BURN SCAR AREAS AND  
CONSIDERING THE MULTIPLE DAY REPEATING NATURE OF THIS ACTIVITY.  
THE BEST CHANCE FOR IMPACTFUL RAINFALL LOOKS TO BE OVER PARTS OF  
COLORADO/NEW MEXICO MAINLY THROUGH SUNDAY WITH FAVORABLE UPSLOPE  
FLOW INTERACTING WITH THE MOISTURE ALREADY IN PLACE. A SLIGHT RISK  
WAS MAINTAINED ACROSS NORTHERN NEW MEXICO ON THE EXPERIMENTAL DAY  
4 EXCESSIVE RAINFALL OUTLOOK WHERE GOOD MODEL AGREEMENT OVERLAPPED  
WITH AREAS THAT HAVE SEEN ANOMALOUS RAINFALL ALREADY. A SLIGHT  
RISK WAS INTRODUCED OVER PARTS OF THE SAME AREA ON DAY 5 DUE TO  
THE CONTINUED STREAM OF HEAVY RAINFALL. MOISTURE WILL CONTINUE  
ROUNDING THE TOP OF THE RIDGE THROUGH THE PLAINS, WHILE  
INTERACTING WITH A COLD FRONT THROUGH THE UPPER MIDWEST, WHERE  
SOME INCREASED THREAT FOR ORGANIZED SHOWERS IS POSSIBLE. THE COLD  
FRONT SHOULD BE FAIRLY PROGRESSIVE THROUGH THE MIDWEST AND INTO  
THE EAST THIS WEEKEND, BUT WITH ENOUGH MOISTURE AND INSTABILITY  
ALONG THE BOUNDARY PRESENT, SOME LOCALLY HIGHER TOTALS SEEM  
LIKELY, SPECIFIC AMOUNTS AND LOCATIONS THOUGH REMAIN HIGHLY  
DEPENDENT ON STILL UNCERTAIN TIMING OF THE FRONT. A WEAK BOUNDARY  
SETTLING ACROSS THE GULF COAST AS WELL AS THE NEXT COLD FRONT  
DROPPING INTO THE REGION, SHOULD ALLOW FOR ENHANCED RAINFALL INTO  
THE MIDDLE OF NEXT WEEK FROM FLORIDA AND ALONG THE GULF COAST.  
 
EXCESSIVE HEAT ACROSS THE SOUTHERN U.S. SHOULD FINALLY BEGIN TO  
WANE THIS WEEKEND THOUGH ANOMALIES AROUND 5 TO 10 DEGREES ABOVE  
NORMAL WILL CONTINUE ACROSS THE LOWER MISSISSIPPI VALLEY AND  
SOUTHERN PLAINS ON SUNDAY, WITH A HANDFUL OF RECORDS BOTH FOR  
DAYTIME HIGHS AND WARM OVERNIGHT MINS. BY EARLY NEXT WEEK,  
TEMPERATURES ALL ACROSS THE SOUTH SHOULD FINALLY TREND BACK  
TOWARDS NORMAL. RELATIVELY COOLER TEMPERATURES WITH WELL BELOW  
NORMAL HIGHS ARE LIKELY TO BE MOST PERSISTENT OVER PARTS OF NEW  
MEXICO AND COLORADO GIVEN THE MONSOONAL CLOUDS AND RAIN COVERAGE.  
IN THE WEST, RIDGING THROUGH THE REGION SHOULD PRESENT AN  
EXCESSIVE HEAT THREAT ACROSS PARTS OF THE NORTHWEST THROUGH MONDAY  
WITH THE ABOVE NORMAL TEMPERATURES THEN TRACKING THROUGH THE  
ROCKIES, PLAINS, AND MIDWEST TUESDAY-THURSDAY.  
 
KEBEDE/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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