892  
FXUS01 KWBC 010758  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
258 AM EST FRI DEC 01 2017  
 
VALID 12Z FRI DEC 01 2017 - 12Z SUN DEC 03 2017  
   
..HEAVY SNOW OVER THE NORTHERN CASCADES
 
 
   
..SNOW POSSIBLE OVER THE SOUTHERN CASCADES AND NORTHERN ROCKIES
 
 
   
..HEAVY RAIN POSSIBLE OVER PARTS OF THE NORTHWEST COAST
 
 
THE UPPER-LEVEL PATTERN HAS GENERALLY AN WEST TO EAST FLOW PATTERN  
THROUGH SATURDAY WHEN THE FLOW PATTERN BECOMES MORE AMPLIFIED OVER  
THE PACIFIC NORTHWEST. EMBEDDED IN THE FAST UPPER-LEVEL FLOW,  
WEAK DISTURBANCES OVER THE SOUTHEAST WILL AID IN PRODUCING  
SCATTERED RAIN OVER THE AREA THROUGH SATURDAY EVENING. IN THE  
MEANTIME, AN UPPER-LEVEL DISTURBANCE OVER THE NORTHEAST WILL MOVE  
EASTWARD OUT OVER THE WESTERN ATLANTIC BY FRIDAY EVENING. RAIN  
WILL DEVELOP OVER PARTS OF NEW ENGLAND THAT WILL BEGIN TO TAPER  
OFF BY FRIDAY AFTERNOON AND END BY FRIDAY EVENING.  
 
MEANWHILE, UPPER-LEVEL ENERGY OVER NORTHERN ROCKIES WILL MOVE  
EASTWARD TO THE GREAT LAKES WHILE INTENSIFYING. THE ENERGY WILL  
PRODUCE AREAS OF RAIN AND SNOW OVER PARTS OF THE UPPER GREAT LAKES  
OVERNIGHT FRIDAY INTO SATURDAY THAT WILL MOVE INTO EASTERN CANADA  
BY SATURDAY EVENING.  
 
WEAK EMBEDDED UPPER-LEVEL IMPULSES WILL AID IN PRODUCING RAIN OVER  
THE PACIFIC NORTHWEST COAST AND SNOW OVER THE HIGHER ELEVATIONS OF  
THE NORTHERN ROCKIES ON FRIDAY MORNING. ON FRIDAY, UPPER-LEVEL  
TROUGHING WILL BEGIN TO MOVE ONSHORE OVER THE PACIFIC NORTHWEST  
THAT WILL SLOWLY INCREASE AS AN UPPER-LEVEL LOW COMES ONSHORE OVER  
THE NORTHWEST ON SATURDAY AFTERNOON INTO EVENING.  
 
MORE TO FOLLOW  
 
ZIEGENFELDER  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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