669  
FXUS02 KWBC 100652  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
252 AM EDT SUN JUL 10 2022  
 
VALID 12Z WED JUL 13 2022 - 12Z SUN JUL 17 2022  
   
..EXCESSIVE RAINFALL THREAT FOR THE CENTRAL GULF COAST STATES
 
 
...GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT...  
 
THE 18 UTC GFS AND 12 UTC ECMWF/ECMWF ENSEMBLE MEAN SEEM TO OFFER  
GUIDANCE SOLUTIONS BEST CLUSTERED WITH WPC CONTINUITY ACROSS THE  
LOWER 48 AND ALSO WITH LATEST NHC GULF OF MEXICO AND WESTERN  
ATLANTIC SYSTEM MONITORRING DETAILS INTO WEDNESDAY/THURSDAY. A  
BLEND SEEMS REASONABLE AND SHOWS DECENT DETAIL CONSISTENT WITH  
FLOW WITH ABOVE NORMAL PREDICTABILITY. THE 00 UTC UKMET/CANADIAN  
NOW BETTER SUPPORT THIS SOLUTION. SWITCHED TO A BLEND OF THE STILL  
COMPATIBLE GFS AND ECMWF ENSEMBLE MEAN AND NATIONAL BLEND OF  
MODELS INTO LATER WEEK AND NEXT WEEKEND IN A PERIOD WHEN RECENT  
ECMWF RUNS HAVE SEEMED TO OFFER LESS SUPPORTED SUBTROPICAL FEATURE  
DEPICTIONS. LATEST 00 UTC GUIDANCE HAS ALSO TRENDED TO PROLONG THE  
CENTRAL GULF COAST HEAVY RAINFALL THREAT THROUGH THESE LATTER TIME  
FRAMES AS THE SUPPORTING SYSTEM BECOMES MORE SEPARATED FROM THE  
STEERING FLOW.  
   
..OVERVIEW AND WEATHER/HAZARDS HIGHLIGHTS
 
 
A MAIN UPPER HIGH/RIDGE WILL SETTLE WESTWARD INTO FOUR CORNERS  
THIS WEEK TO SUPPORT ABOVE NORMAL TEMPERATURES ACROSS MUCH OF THE  
WEST, BUT THE MOST ANOMALOUS HEAT IS FORECAST TO SPREAD DOWNSTREAM  
ACROSS THE NORTH-CENTRAL U.S. AS RIDGING/HEIGHTS BUILD OVER THE  
REGION. IN THIS PATTERN, MONSOONAL MOISTURE FLOW ACROSS THE  
SOUTHWEST INTO THE GREAT BASIN/ROCKIES MAY OFFER DAILY CHANCES FOR  
SHOWERS WITH SOME LOCALLY HEAVIER DOWNPOURS. MEANWHILE, A SERIES  
OF UNCERTAIN IMPULSES WILL ROUND THE TOP OF THE RIDGE TO  
PERIODICALLY FOCUS STRONG CONVECTION LOCALLY OVER THE  
NORTH-CENTRAL PLAINS/UPPER MIDWEST.  
 
UPPER TROUGH POSITIONS WILL SANDWICH THE UPPER RIDGE BOTH OFF THE  
PACIFIC NORTHWEST WHERE RAINFALL CHANCES ARE LIMITED AND ALSO THE  
EAST WHERE FRONTS WILL FOCUS RAIN AND THUNDERSTORMS. MOISTURE WILL  
POOL FROM THE EASTERN MID-ATLANTIC TO THE SOUTHEAST AND GULF COAST  
STATES NEAR A WAVY STALLED LEAD FRONT. INTERACTION WITH A  
SUB-TROPICICAL DISTURBANCE MAY IN PARTICULAR SUPPORT HEAVY RAIN  
POTENTIAL NEAR THE CENTRAL GULF COAST. THIS COULD FOCUS  
SLOW-MOVING/REPEAT CELLS WITH VERY HEAVY DOWNPOURS LEADING TO A  
LOCAL RUNOFF ISSUES, SO A "SLIGHT" RISK AREA WAS ADDED TO THE  
EXPERIMENTAL WPC MEDIUM RANGE EXCESSIVE RAINFALL OUTLOOK THROUGH  
MIDWEEK.  
 
SCHICHTEL  
 
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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