795  
FXUS02 KWBC 051557  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1156 AM EDT THU JUL 05 2018  
 
VALID 12Z SUN JUL 08 2018 - 12Z THU JUL 12 2018  
 
...WEATHER THREATS/HIGHLIGHTS AND GUIDANCE  
EVALUATION/PREFERENCES...  
 
IT REMAINS THE CASE THAT AN UPPER HIGH WILL DOMINATE MUCH OF THE  
LOWER 48 NEXT WEEK. TROUGHS OVER THE NORTHWEST AND NORTHEAST  
OVERALL FLATTEN WITH TIME AS A MORE ZONAL FLOW TAKES SHAPE ALONG  
THE US/CANADIAN BORDER. HEIGHTS WILL BECOME ABOVE AVERAGE COAST TO  
COAST WHICH SUPPORTS NEAR TO ABOVE AVERAGE TEMPERATURES OVER MOST  
AREAS OUTSIDE THE SOUTHERN TIER. A MODERATING FRONT IN THE EAST  
WILL DISSIPATE NEXT WEEK AS WESTERN NORTH AMERICAN FRONTS SHIFT  
DOWNSTREAM ACROSS THE NORTHERN PLAINS, UPPER MIDWEST/GREAT LAKES  
AND NORTHEAST ALONG WITH THUNDERSTORM FOCUS AND LOCAL SEVERE STORM  
THREAT AS PER SPC. THE SOUTHWEST WILL SEE ENHANCED MONSOONAL  
MOISTURE AROUND THE UPPER HIGH REALIZED AS PRECIPITATION INITIALLY  
OVER THE HIGHER TERRAIN AND THEN INTO SOME OF THE LOWER DESERTS.  
 
THE WPC MEDIUM RANGE PRODUCT SUITE WAS MAINLY DERIVED FROM A BLEND  
OF REASONABLY CLUSTERED GUIDANCE FROM THE 00 UTC GFS/ECMWF AND  
NAEFS/ECMWF ENSEMBLES INTO DAY 5/TUE. QUICKLY SWITCHED TO  
ENSEMBLES ONLY LATER TUESDAY TO DAYS 6/7 GIVEN INCREASING MODEL  
FORECAST SPREAD/SMALLER SCALE SYSTEM UNCERTAINTY. THE 06 UTC  
GFS/GEFS TRENDED TOWARD PROGRESSION, BUT THIS SCENARIO SEEMS LESS  
LIKELY CONSIDERING UPSTREAM NORTHERN PACIFIC TO ALASKAN FLOW  
AMPLIFICATION.  
 
SCHICHTEL  
 
WPC MEDIUM RANGE 500 MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION, WINTER WEATHER OUTLOOK PROBABILITIES  
AND HEAT INDEXES ARE FOUND AT:  
 
HTTP://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF  
HTTP://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF  
HTTP://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML  
HTTP://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML  
HTTP://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4  
HTTP://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML  
 

 
 
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