202  
FXUS02 KWBC 020749  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
349 AM EDT TUE AUG 02 2022  
 
VALID 12Z FRI AUG 05 2022 - 12Z TUE AUG 09 2022  
 
...THE SOUTHWEST MONSOON RESUMES A VERY ACTIVE PHASE LATE THIS  
WEEK...  
...HEAVY RAIN LIKELY FROM THE OHIO VALLEY THROUGH THE NORTHEAST  
LATE THIS WORK WEEK***  
 
   
..GENERAL OVERVIEW
 
 
ACTIVE UPPER LEVEL FLOW PATTERN WILL CONTINUE ACROSS SOUTHERN  
CANADA/NEAR THE U.S. BORDER OVER THE NEXT WEEK AS THE PERSISTENT  
HUDSON BAY LOW IS DISLODGED EAST AROUND THURSDAY. A WELL DEFINED  
COLD FRONT WILL SLOW/STALL AS IT TRACKS EAST ACROSS THE LOWER  
GREAT LAKES THURSDAY AND NEW ENGLAND ON FRIDAY. THE NEXT COLD  
FRONT PASSES THROUGH THE NORTHERN PLAINS THURSDAY NIGHT/FRIDAY AND  
THE UPPER MIDWEST/GREAT LAKES THIS WEEKEND. MEANWHILE, THE CORE OF  
THE UPPER RIDGE INTENSIFIES AS IT DRIFTS EAST TO THE CENTRAL  
PLAINS THURSDAY INTO FRIDAY FRIDAY BEFORE DRIFTING BACK WEST THIS  
WEEKEND. AS A RESULT THE MONSOONAL PATTERN ACROSS THE FOUR CORNERS  
REGION RE-INTENSIFIES THURSDAY WITH A RATHER ACTIVE PERIOD THROUGH  
AT LEAST THE WEEKEND.  
 
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
A RELATIVELY STRAIGHTFORWARD SYNOPTIC PATTERN, WITH HIGH PRESSURE  
STATIONED OVER THE CENTRAL/SOUTHERN U.S. AND WAVES OF LOW PRESSURE  
SWINGING ACROSS THE NORTHERN TIER, WAS CAPTURED WELL BY THE  
GUIDANCE THROUGH THE MEDIUM RANGE. A CONSISTENTLY SLOWER EC  
APPEARED TO BE THE MAIN SOURCE OF UNCERTAINTY DURING THE MEDIUM  
RANGE PERIOD. A GENERAL MODEL BLEND OF THE 12Z EC/UK/CMC AND 18Z  
GFS WERE UTILIZED ON DAYS 3 AND 4. THE 12Z EC WAS WEIGHTED LESS ON  
DAY 4 DUE TO THE SLOWNESS NOTED IN THE MASS FIELDS WITH RESPECT TO  
THE UPPER TROUGH MOVING THROUGH SOUTHERN CANADA AND THE NORTHERN  
PLAINS. THE 12Z ECE AND 18Z GEFS WERE INTRODUCED TO THE BLEND ON  
DAYS 5 AND 6 TO ACCOUNT FOR TIMING AND INTENSITY DISCREPANCIES  
BETWEEN THE DETERMINISTICS WITH RESPECT TO A SECOND TROUGH MOVING  
THROUGH THE SOUTHERN CANADA. 12Z EC/ECE/CMCE AND 18Z GEFS WERE  
FAVORED BY DAY 7 TO ACCOUNT FOR STANDARD SPREAD IN THE PATTERN.  
 
   
..WEATHER/HAZARDS HIGHLIGHTS
 
 
ANOTHER EASTWARD MOVING WAVE OF ANOMALOUS HEAT IS EXPECTED TO  
CROSS THE NORTHERN PLAINS FRIDAY - SATURDAY WHICH WILL BE SIMILAR  
TO THE WAVE THAT CROSSED EARLIER THIS WEEK. MEANWHILE, MAXIMUM  
TEMPERATURES WILL LIKELY BE NEAR TO SLIGHTLY BELOW NORMAL ACROSS  
MUCH OF THE WESTERN U.S. FOR MOST OF THE FORECAST PERIOD. THIS  
WAVE LOOKS TO REACH THE NORTHEAST BY SUNDAY WITH ANOTHER BRIEF  
WAVE OF HIGH TEMPERATURES EXPECTED TO CONTINUE AHEAD OF A COLD  
FRONT INTO MONDAY. MEANWHILE, MONSOONAL CLOUDS AND RAIN OFFER  
BELOW NORMAL MAX TEMPS FOR THE DESERT SOUTHWEST TO THE GREAT BASIN  
TO SOUTHERN ROCKIES.  
 
FOR PRECIPITATION, MONSOONAL MOISTURES IN THE SOUTHWEST AND HEAVY  
RAINFALL FOCUSED ALONG A COLD FRONT WILL BE THE MAIN THREATS FOR  
FLASH FLOODING. HEAVY RAINFALL CAUSED BY MONSOONAL MOISTURE WILL  
IMPACT THE DESERT SOUTHWEST UP INTO THE CENTRAL GREAT BASIN ON  
SATURDAY AND SUNDAY WHERE SLIGHT RISKS OF EXCESSIVE RAINFALL  
LEADING TO FLASH FLOODING IS IN EFFECT. MEANWHILE ADDITIONAL  
MOISTURE MAKES ITS WAY UP INTO CENTRAL COLORADO ON SUNDAY  
PROMPTING A SEPARATE SLIGHT RISK AREA FOR PORTIONS OF THE COLORADO  
ROCKIES AND FOOTHILLS. A COLD FRONT STALLING OVER THE  
NORTHEAST/MID-ATLANTIC MAY LEAD TO ADDITIONAL FLASH FLOODING RISK,  
ALTHOUGH, THAT RISK IS MARGINAL DUE TO SPREAD IN THE GUIDANCE.  
 
KEBEDE/JACKSON  
 
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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