807  
FXUS02 KWBC 300700  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
259 AM EDT THU JUN 30 2022  
 
VALID 12Z SUN JUL 3 2022 - 12Z THU JUL 7 2022  
   
..OVERVIEW
 
 
BROAD CYCLONIC FLOW ALOFT WILL BE IN PLACE ACROSS THE  
NORTH-CENTRAL U.S. FOR THE SUNDAY TO MONDAY TIME PERIOD AS A  
ANOMALOUS UPPER LOW LINGERS OVER FAR NORTHERN QUEBEC. ANOTHER  
SYNOPTIC SCALE TROUGH IS EXPECTED TO REMAIN OVER THE EASTERN  
PACIFIC THROUGH MUCH OF THE FORECAST PERIOD WITH MULTIPLE  
SHORTWAVE PERTURBATIONS PIVOTING AROUND IT. AN UPPER LEVEL RIDGE  
IS EXPECTED TO BUILD ACROSS THE CENTRAL HIGH PLAINS IN RESPONSE TO  
THIS TROUGH. A QUASI-STATIONARY FRONTAL BOUNDARY WITH MULTIPLE  
ROUNDS OF SHOWERS AND STORMS IS EXPECTED FROM THE DAKOTAS TO THE  
GREAT LAKES THROUGH THE MIDDLE OF NEXT WEEK.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
ON THE SYNOPTIC SCALE, THE 00Z GUIDANCE REMAINS IN VERY GOOD  
AGREEMENT ON PLACEMENT AND AMPLITUDE OF THE WEST COAST TROUGH,  
PLAINS UPPER RIDGE, AND TROUGH OVER EASTERN CANADA THROUGH THE  
MAJORITY OF THE FORECAST PERIOD. SIMILAR TO THE PAST COUPLE OF  
DAYS, THERE ARE STILL SOME MESOSCALE DETAIL DIFFERENCES WITH THE  
INDIVIDUAL SHORTWAVES THAT WILL GOVERN THE MAGNITUDE AND EXTENT OF  
HEAVY RAIN ACROSS THE PLAINS AND MIDWEST, SO THE NBM AND THE  
BIASED CORRECTED ENSEMBLE MODEL FOR QPF SERVED AS A GOOD STARTING  
POINT IN THE FORECAST PROCESS. FOR FRONTS/PRESSURES, A  
MULTI-DETERMINISTIC BLEND WORKED WELL FOR SUNDAY-TUESDAY, FOLLOWED  
BY SOME OF THE GEFS/ECENS FOR WEDNESDAY-THURSDAY TO ACCOUNT FOR  
INCREASING MESOSCALE DIFFERENCES.  
   
..SENSIBLE WEATHER AND POTENTIAL HAZARDS
 
 
SCATTERED SHOWERS AND STORMS ARE EXPECTED ACROSS THE SOUTHEAST  
THIS WEEKEND WITH THE PRESENCE OF A WEAKENING FRONTAL BOUNDARY AND  
WEAK IMPULSES MOVING THROUGH THE FLOW ALOFT. FARTHER NORTH, A  
FRONT INITIALLY ORIENTED FROM THE NORTHEAST INTO THE OHIO VALLEY  
AND CENTRAL PLAINS WILL PUSH GRADUALLY EASTWARD DURING THE WEEKEND  
AND SUPPORT ORGANIZED AREAS OF SHOWERS AND STORMS ALONG AND AHEAD  
OF IT. SOME RAINFALL MAY BE LOCALLY HEAVY FROM THE CENTRAL PLAINS  
INTO THE MID-ATLANTIC ON SUNDAY AS MOISTURE CONVERGES ALONG A  
QUASI-STATIONARY FRONTAL ZONE. THIS FRONT MAY CONTINUE TO BE A  
FOCUS FOR RAINFALL INTO EARLY NEXT WEEK AS WELL. MONSOONAL  
MOISTURE OVER THE SOUTHERN ROCKIES IS ALSO EXPECTED TO LEAD TO  
MAINLY DIURNALLY DRIVEN SHOWERS AND STORMS, WITH WEAK SHORTWAVES  
AND MOISTURE LIFTING NORTHWARD BETWEEN UPPER RIDGING TO THE EAST  
AND THE TROUGH NEAR THE WEST COAST. THE WEST COAST TROUGH WILL  
LIKELY PRODUCE PERIODS OF RAINFALL OVER PARTS OF THE NORTHWEST,  
AND THERE CONTINUES TO BE A SIGNAL FOR A PERIOD OF HEAVIER  
RAINFALL NEAR THE CANADIAN BORDER EARLY NEXT WEEK. SOME MESOSCALE  
CONVECTIVE SYSTEMS COULD ALSO EXTEND ACROSS THE NORTHERN  
PLAINS/UPPER MIDWEST, AIDED BY NORTHERN TIER SURFACE FEATURES AND  
SHORTWAVES EMERGING FROM THE WEST.  
 
THE GREATEST CONCERN FOR TEMPERATURES WILL BE WITH HEAT EXPECTED  
TO BUILD AGAIN ACROSS THE CENTRAL AND NORTHERN PLAINS BY EARLY  
NEXT WEEK IN RESPONSE TO A STRENGTHENING UPPER LEVEL RIDGE. HIGHS  
OF 5-15 DEGREES ABOVE NORMAL ARE POSSIBLE OVER THE CENTRAL PLAINS,  
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. OUT WEST, BELOW NORMAL HIGHS WILL  
SPREAD GRADUALLY INLAND FROM THE WEST COAST DURING THE WEEKEND  
INTO EARLY NEXT WEEK DUE TO NEARBY UPPER TROUGHING. A FEW  
LOCATIONS MAY SEE HIGHS 10-15F BELOW NORMAL AROUND SUNDAY-MONDAY.  
EXPECT A MODERATING TREND CLOSER TO NORMAL HEADING INTO MIDWEEK.  
ACROSS THE EASTERN U.S., A STABLE UPPER PATTERN OF WESTERLIES  
ACROSS THE NORTHEAST AND RIDGING OVER THE SOUTH SHOULD KEEP BOTH  
DAYTIME HIGHS AND OVERNIGHT LOWS WITHIN A FEW DEGREES OF  
CLIMATOLOGICAL AVERAGES THROUGH MOST OF THE PERIOD.  
 
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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