647  
FXUS02 KWBC 020700  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 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  
DAY 5 TO ACCOUNT FOR TIMING AND INTENSITY DISCREPANCIES BETWEEN  
THE DETERMINISTICS WITH RESPECT TO A SECOND TROUGH MOVING THROUGH  
THE SOUTHERN CANADA.  
 
   
..WEATHER/HAZARDS HIGHLIGHTS
 
 
ANOTHER EASTWARD MOVING WAVE OF ANOMALOUS HEAT IS EXPECTED TO  
CROSS THE NORTHERN PLAINS THURSDAY - SATURDAY WHICH WILL BE  
SIMILAR TO THE WAVE CROSSING THE FIRST HALF OF THIS WEEK. THIS  
WITH 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, TWO GENERAL ROUNDS OF HEAVY RAIN ARE EXPECTED  
AHEAD OF THE TWO COLD FRONTS OVER THE CENTRAL AND NORTHERN  
PORTIONS OF THE EASTERN CONUS - THUR/FRI AND SUN/MON. A SECOND  
SLIGHT RISK OF EXCESSIVE RAINFALL WAS ADDED TO THE DAY 4 OUTLOOK  
OVER THE EASTERN GREAT LAKES AND ONE WAS ADDED FOR THE BOS-WASH  
MEGALOPOLIS FOR DAY 5 - BOTH HAVE DECENT AGREEMENT AMONG GLOBAL  
DETERMINISTIC GUIDANCE FOR HEAVY RAIN FOCUS THERE AHEAD OF A SLOW  
MOVING COLD FRONT. THE MONSOON REINVIGORATES IN THE SOUTHWEST AS  
THE RIDGE STRENGTHENS AFTER A MIDWEEK PERIOD OF MORE DIFFUSE  
MONSOON. SLIGHT RISKS WERE EXPANDED OVER THE SOUTHWEST FOR BOTH  
DAYS 4 AND 5 FOR THIS INCREASED THREAT.  
 
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  
 
HAZARDS:  
- HEAVY RAIN ACROSS PORTIONS OF THE CENTRAL ROCKIES, THE CENTRAL  
GREAT BASIN, CALIFORNIA, AND THE SOUTHWEST, THU-MON, AUG 4-AUG 8.  
- HEAVY RAIN ACROSS PORTIONS OF THE LOWER GREAT LAKES, AND THE  
OHIO VALLEY, THU, AUG 4.  
- HEAVY RAIN ACROSS PORTIONS OF THE NORTHEAST, THE MID-ATLANTIC,  
AND THE CENTRAL APPALACHIANS, FRI, AUG 5.  
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE OHIO  
VALLEY AND THE NORTHERN PLAINS.  
- EXCESSIVE HEAT ACROSS PORTIONS OF THE THE LOWER MISSISSIPPI  
VALLEY, AND THE SOUTHERN PLAINS, THU-MON, AUG 4-AUG 8.  
- EXCESSIVE HEAT ACROSS PORTIONS OF THE CENTRAL PLAINS, AND THE  
MIDDLE MISSISSIPPI VALLEY, SAT-SUN, AUG 6-AUG 7.  
- EXCESSIVE HEAT ACROSS PORTIONS OF THE NORTHEAST, THE CENTRAL  
APPALACHIANS, AND THE NORTHERN PLAINS, THU-FRI, AUG 4-AUG 5.  
- HEAVY RAIN ACROSS PORTIONS OF THE ALASKA PANHANDLE AND SOUTHEAST  
MAINLAND ALASKA, FRI-SAT, AUG 5-AUG 6.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF NORTHERN  
MAINLAND ALASKA, SAT-MON, AUG 6-AUG 8.  
 
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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