421  
FXUS01 KWBC 210748  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
348 AM EDT SAT OCT 21 2017  
 
VALID 12Z SAT OCT 21 2017 - 12Z MON OCT 23 2017  
 
...UNSETTLED FOR THE NORTHWESTERN U.S. AND PLEASANT FOR THE EAST  
COAST STATES THROUGH SUNDAY...  
 
HEAVY RAIN AND HIGH ELEVATION SNOW WILL BE THE MAIN WEATHER STORY  
ACROSS THE PACIFIC NORTHWEST AND NORTHERN ROCKIES THIS WEEKEND AS  
A STRONG LOW PRESSURE SYSTEM TRACKS EASTWARD ACROSS THE REGION.  
THIS ATMOSPHERIC RIVER WILL LIKELY RESULT IN SEVERAL INCHES OF  
RAINFALL ACROSS PARTS OF WESTERN OREGON AND WASHINGTON, WITH SOME  
LOCATIONS GETTING IN EXCESS OF FIVE INCHES. SNOW WILL BE HEAVY  
FOR THE HIGHER MOUNTAIN RANGES OF THE NORTHERN ROCKIES, AND ALSO  
FOR THE NORTHERN CASCADES.  
 
THE COLD FRONT CURRENTLY TRACKING ACROSS THE CENTRAL AND NORTHERN  
PLAINS IS EXPECTED TO REACH THE GREAT LAKES REGION AND MISSISSIPPI  
RIVER BY SUNDAY EVENING IN ASSOCIATION WITH AN AMPLIFIED UPPER  
LEVEL TROUGH. SEVERE THUNDERSTORMS WILL LIKELY DEVELOP FROM  
NORTHERN TEXAS TO IOWA AHEAD OF THE FRONT ON SATURDAY, AND THE  
STORM PREDICTION CENTER HAS ADDITIONAL DETAILS ON THIS THREAT.  
WITH A WAVE OF LOW PRESSURE DEVELOPING ALONG THIS FRONT OVER THE  
LOWER MISSISSIPPI RIVER VALLEY, MOISTURE INFLOW FROM THE GULF OF  
MEXICO WILL BE ENHANCED AND THIS COULD LEAD TO AREAS OF HEAVY  
RAINFALL FROM EASTERN OKLAHOMA TO MISSISSIPPI.  
 
ELSEWHERE ACROSS THE CONTINENTAL U.S., EXPECT MILD TO WARM WEATHER  
TO CONTINUE ACROSS THE EAST WITH WIDESPREAD 70S FOR HIGHS THIS  
WEEKEND BEFORE COOLER CONDITIONS ARRIVE NEXT WEEK. FIRE WEATHER  
CONCERNS WILL CONTINUE ACROSS PARTS OF CALIFORNIA OVER THE NEXT  
FEW DAYS WITH VERY DRY CONDITIONS AND GUSTY WINDS EXPECTED.  
 
D. HAMRICK  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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