278  
FXUS02 KWBC 010649  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
248 AM EDT FRI JUL 01 2022  
 
VALID 12Z MON JUL 04 2022 - 12Z FRI JUL 08 2022  
   
..OVERVIEW
 
 
A PERSISTENT UPPER LEVEL HIGH LOOKS TO BE IN PLACE NEXT WEEK OVER  
THE SOUTH-CENTRAL AND SOUTHEASTERN U.S. IN A COMMON SUMMER  
PATTERN, CAUSING HOT TEMPERATURES ACROSS MUCH OF THE CENTRAL  
CONUS. THE STORM TRACK WILL THUS REMAIN FARTHER NORTH, WITH A  
RELOADING UPPER LOW ACROSS THE EASTERN PACIFIC/NORTHWEST U.S. AND  
SHORTWAVES AND PERIODS OF TROUGHING THROUGH THE REST OF THE  
NORTHERN TIER, THOUGH BY THE LATTER PART OF THE WEEK RIDGING COULD  
BUILD INTO THE NORTHERN ROCKIES/HIGH PLAINS. AT THE SURFACE, A  
QUASI-STATIONARY FRONTAL BOUNDARY DRAPED FROM THE NORTH-CENTRAL  
PLAINS TO THE MID-ATLANTIC WILL FOCUS SHOWERS AND STORMS, WITH  
SOME LOCALLY HEAVY RAINFALL.  
 
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
RECENT MODEL GUIDANCE REMAINS IN GOOD AGREEMENT WITH THE SYNOPTIC  
PATTERN DESCRIBED ABOVE ESPECIALLY THROUGH THE MIDDLE OF NEXT  
WEEK, AND A BLEND OF THE DETERMINISTIC 12Z ECMWF, CMC, AND UKMET  
AND THE 18Z GFS WORKED WELL FOR THE FIRST HALF OF THE WPC MEDIUM  
RANGE FORECAST. BY THURSDAY-FRIDAY, THE 12Z CMC BECOMES DIFFERENT  
FROM CONSENSUS WITH AN EASTERN CANADA/NORTHEASTERN U.S. TROUGH,  
WITH ITS AXIS EAST OF THE AGREEABLE GFS/ECMWF SOLUTIONS. THUS  
PHASED OUT THE CMC IN FAVOR OF THE GEFS AND ECMWF ENSEMBLE MEAN  
GUIDANCE BY THE LATTER PART OF THE PERIOD, BUT MAINTAINED A  
MAJORITY OF THE OPERATIONAL GFS/ECMWF CONSIDERING THEIR GOOD  
AGREEMENT ON THE LARGE SCALE. HOWEVER, THE SMALLER SCALE FEATURES  
LIKE INDIVIDUAL SHORTWAVES SHOW CONSIDERABLY MORE VARIABILITY FROM  
MODEL TO MODEL, WHICH WILL LIKELY TAKE UNTIL THE SHORT RANGE  
PERIOD TO RESOLVE. UNFORTUNATELY THIS IS A PATTERN IN WHICH THESE  
MESOSCALE FEATURES MATTER GREATLY PARTICULARLY FOR QPF PLACEMENT  
AND AMOUNTS, SO CONTINUE TO FOLLOW UPDATES TO THE FORECAST FOR  
CHANGES GOING FORWARD.  
 
   
..SENSIBLE WEATHER AND HAZARDS
 
 
SCATTERED SHOWERS AND STORMS ARE LIKELY ACROSS MUCH OF THE U.S. AT  
TIMES NEXT WEEK, WITH ENHANCED TOTALS IN THE VICINITY OF A COUPLE  
OF FRONTAL BOUNDARIES STRETCHING GENERALLY WEST TO EAST ACROSS THE  
NORTHERN HALF OF THE COUNTRY. PARTS OF THE NORTHWEST INTO THE  
NORTHERN HIGH PLAINS COULD SEE MODERATE TO HEAVY RAINFALL INTO  
MONDAY AS A STRONG SHORTWAVE PASSES NEARBY. DOWNSTREAM,  
POTENTIALLY HEAVY RAINFALL IS FORECAST TO FOCUS OVER PARTS OF THE  
MIDWEST AND SHIFTING TOWARD THE CENTRAL APPALACHIANS AS WELL  
MONDAY-TUESDAY WITH THE POSSIBILITY OF MESOSCALE CONVECTIVE  
SYSTEMS AND HIGH RAINFALL RATES WHERE THERE IS ABUNDANT MOISTURE  
AND INSTABILITY. SLIGHT RISKS OF EXCESSIVE RAINFALL ARE IN PLACE  
FOR THOSE AREAS IN THE WPC EXPERIMENTAL EXCESSIVE RAINFALL OUTLOOK  
FOR DAYS 4-5. SCATTERED THUNDERSTORMS ARE ALSO LIKELY IN THE  
SOUTHEAST THROUGH THE WEEK, AND SOME MID-ATLANTIC TO NORTHEAST  
RAIN EVENTS ARE POSSIBLE AS WELL DEPENDENT ON FRONTAL POSITIONS.  
MEANWHILE MONSOONAL MOISTURE COULD PERSIST THROUGH MUCH OF THE  
WEEK WITH SOUTHWESTERLY FLOW FROM THE EASTERN PACIFIC, LEADING TO  
MAINLY DIURNALLY DRIVEN SHOWERS AND STORMS OVER THE FOUR CORNERS  
STATES.  
 
THE GREATEST CONCERN FOR TEMPERATURES WILL BE WITH HEAT EXPECTED  
TO BUILD AGAIN ACROSS THE CENTRAL U.S. BY EARLY NEXT WEEK IN  
RESPONSE TO A STRENGTHENING UPPER LEVEL RIDGE. HIGHS OF 10-15  
DEGREES ABOVE NORMAL ARE FORECAST FOR THE CENTRAL PLAINS TO MIDDLE  
MISSISSIPPI VALLEY, EQUATING TO TEMPERATURES IN THE MID 90S TO LOW  
100S. SOUTHERN PLAINS LOCATIONS WILL SEE A SLIGHTLY HOTTER TREND  
AS WELL, BUT WITH LESS EXTREME ANOMALIES. WARMER THAN AVERAGE  
TEMPERATURES MAY BUILD INTO THE NORTHERN ROCKIES TO NORTHERN  
PLAINS BY THURSDAY-FRIDAY. MEANWHILE THE WEST IS FORECAST TO BE  
COOLER THAN NORMAL IN RESPONSE TO TROUGHING ALOFT, BUT SHOULD  
MODERATE CLOSER TO NORMAL AS THE PERIOD PROGRESSES. THE EAST IS  
LIKELY TO BE NEAR AVERAGE TEMPERATURE-WISE.  
 
TATE  
 
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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