476  
FXUS02 KWBC 130637  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
236 AM EDT WED JUL 13 2022  
 
VALID 12Z SAT JUL 16 2022 - 12Z WED JUL 20 2022  
   
..HEAT THREAT TO LOOM OVER MUCH OF THE WESTERN AND CENTRAL U.S.
 
 
...HEAVY RAINFALL THREAT FOR THE CENTRAL GULF COAST STATES AND  
SOUTHEAST...  
 
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
GUIDANCE OVERALL OFFERS A DECENTLY SIMILAR MID-LARGER SCALE  
PATTERN EVOLUTION FOR THIS WEEKEND AND A COMPOSITE MODEL, ENSEMBLE  
AND NATIONAL BLEND OF MODELS (NBM) SOLUTION SEEMS TO PROVIDE A  
GOOD FORECAST BASIS. THIS INCLUDES FOR UPPER TROUGHING BREAKING  
INLAND TO THE PACIFIC NORTHWEST AS WELL AS FOR AN UPPER TROUGH  
OVER THE EAST MAINTAINED AS SHORTWAVE ENERGIES DIGS TO THE LEE OF  
A BUILDING WEST-CENTRAL U.S. UPPER RIDGE. THE RIDGE WILL REINFORCE  
WIDESPREAD SUMMER HEAT ACROSS MUCH OF THE WESTERN AND CENTRAL U.S.  
THIS WEEKEND AND PERSIST NEXT WEEK TO CONTINUE SUPPORT FOR SOME  
LOCAL RECORD VALUES SPREAD OVER A WIDE DOMAIN. THE HEAT FORECAST  
HAS HIGH PREDICTABILITY.  
 
HOWEVER, HIGH UNCERTAINTY REMAINS ALONG THE CENTRAL GULF COAST  
WHERE SOME UPPER LEVEL ENERGY MAY BE LEFT BEHIND THIS WEEK UNDER A  
COL ALOFT VERSUS BEING SPLIT OT EJECTED AND THE DETAILS LOOM LARGE  
ON THE THREAT POTENTIAL FOR HEAVY RAINFALL INTO SOME WET SOILS  
FROM THE CENTRAL GULF COAST TO PARTS OF THE SOUTHEAST. EARLIER  
RUNS OF THE ECMWF AND UKMET IN PARTICULAR DEVELOPED A TROPICAL  
LOW, AND THE NATIONAL HURRICANE CENTER (NHC) CONTINUES TO MONITOR.  
HOWEVER, OVERALL SYSTEM SIGNAL IN GUIDANCE AND WPC QPF HAS  
STEADILY TRENDED BACK THE LAST SEVERAL FORECASTS. PLEASE REFER TO  
NHC TROPICAL WEATHER OUTLOOKS FOR FEATURE UPDATES. THERE IS MORE  
OF A GUIDANCE SIGNAL TO LIFT A DIFFERENT TROPICAL IMPULSE  
NORTHWARD JUST OFF THE EAST COAST OF FLORIDA TOWARD THE COASTAL  
SOUTHEAST TO FUEL WEEKEND RAINS.  
 
MODEL FORECAST SPREAD ALSO BECOMES MORE NOTEWORTHY BY EARLY NEXT  
WEEK WITH THE INLAND EJECTION OF PACIFIC UPPER TROUGHING. THE 00  
UTC AND ESPECIALLY THE 12 UTC CMC RUNS ARE MORE PROGRESSIVE THAN  
THE GFS/ECMWF/UKMET AS THE SYSTEM WORKS FROM THE NORTHWEST  
DOWNSTREAM ACROSS THE U.S. NORTHERN TIER. THIS ALONG WITH SMALLER  
SCALE SYSTEM DIFFERENCES THAT GROW OVER THE REST OF THE CONUS  
DURING THIS TIME PERIOD SEEM TO OVERALL JUSTISTY PREFERENCE FOCUS  
ON THE WELL BLENDED GEFS/ECMWF ENSEMBLE MEANS AND NBM SOLUTIONS  
THAT TEND TO MITIGATE VARIANCE CONSISTENT WITH UNCERTAINTY. THIS  
ALSO ACTS TO MAINTAIN MAXIMUM WPC PRODUCT CONTINUITY AT THESE  
LONGER TIME FRAMES.  
   
..OVERVIEW AND WEATHER/HAZARDS HIGHLIGHTS
 
 
A HOT UPPER HIGH/RIDGE WILL SETTLE WESTWARD INTO THE FOUR CORNERS  
TO SUPPORT ABOVE NORMAL TEMPERATURES ACROSS MUCH OF THE WEST, BUT  
ALSO WITH WIDESPREAD HEAT TO PERSIST DOWNSTREAM ACROSS THE CENTRAL  
U.S. AS RIDGING/HEIGHTS BUILD OVER THE REGION. IN THIS PATTERN,  
MODEST MONSOONAL MOISTURE FLOW ACROSS THE SOUTHWEST INTO THE GREAT  
BASIN/ROCKIES UNDER THE UPPER RIDGE MAY OFFER DAILY CHANCES FOR  
SHOWERS WITH SOME LOCALLY HEAVIER DOWNPOURS WITH SLOWED CELL  
MOTIONS. MEANWHILE, A SERIES OF UNCERTAIN IMPULSES WILL ROUND THE  
TOP OF THE RIDGE TO PERIODICALLY FOCUS STRONG BUT MORE PROGRESSIVE  
CONVECTION OUT FROM THE NORTH-CENTRAL U.S./MIDWEST.  
 
UPPER TROUGH POSITIONS WILL SANDWICH THE UPPER RIDGE, BOTH INTO  
THE PACIFIC NORTHWEST WHERE RAINFALL CHANCES ARE LIMITED AND ALSO  
THE EAST WHERE FRONTS WILL FOCUS SOME RAIN AND THUNDERSTORMS.  
MOISTURE WILL POOL FROM THE EASTERN MID-ATLANTIC TO THE SOUTHEAST  
AND GULF COAST STATES. POSSIBLE SUB-TROPICAL/TROPICAL INTERACTION  
OVER THE NORTHERN THE GULF OF MEXICO MAY SUPPORT HEAVY RAIN  
POTENTIAL INTO THE CENTRAL GULF COAST AND VICINITY AS ANY  
SLOW-MOVING AND REPEAT CELLS WITH VERY HEAVY DOWNPOURS WOULD STILL  
LEAD TO LOCAL RUNOFF ISSUES. ADDITIONAL TROPICAL INFLUENCES ALSO  
REMAIN IN PLAY UP THE ATLANTIC COAST OF FLORIDA TO THE COASTAL  
CAROLINAS THIS WEEKEND AS THE LIFTING OF ENERGY AND DEEPENED  
MOISTURE COULD ACT TO MORE DEEPLY FUEL A RAINFALL/RUNOFF THREAT  
ACROSS THIS AREA.  
 
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  
 

 
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page