688  
FXUS01 KWBC 192012  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
412 PM EDT THU OCT 19 2017  
 
VALID 00Z FRI OCT 20 2017 - 00Z SUN OCT 22 2017  
   
..HEAVY SNOW FOR THE NORTHERN CASCADES
 
 
...SNOW FOR PARTS OF THE CASCADES AND NORTHERN/CENTRAL ROCKIES  
ALONG WITH THE SIERRAS...  
   
..HEAVY RAIN POSSIBLE OVER THE PACIFIC NORTHWEST
 
 
A FRONT OVER THE NORTHWEST WILL STEADILY MOVES EASTWARD TO THE  
NORTHERN/CENTRAL PLAINS AND SOUTHERN HIGH PLAINS BY SATURDAY. THE  
SYSTEM WILL PRODUCE RAIN, HEAVY AT TIMES OVER PARTS OF NORTHERN  
CALIFORNIA AND THE PACIFIC NORTHWEST THAT WILL MOVE EASTWARD INTO  
THE NORTHERN INTERMOUNTAIN REGION AND INTO CENTRAL CALIFORNIA BY  
FRIDAY MORNING. AS THE BOUNDARY MOVES INLAND THE SNOW LEVELS WILL  
LOWER WITH SNOW STARTING OVERNIGHT IN THE HIGHER ELEVATIONS OF THE  
CASCADES AND THE SISKIYOUS/SHASTA WITH SNOW DEVELOPING OVER THE  
HIGHEST ELEVATIONS OF THE SIERRAS BY FRIDAY MORNING. ON FRIDAY,  
SNOW AND LOWER ELEVATION RAIN WILL DEVELOP OVER PARTS OF THE  
NORTHERN INTERMOUNTAIN REGION/NORTHERN ROCKIES INTO PARTS OF THE  
GREAT BASIN THAT WILL EXPAND INTO THE CENTRAL ROCKIES WITH RAIN  
OVER THE NORTHERN HIGH PLAINS BY SATURDAY MORNING. BEHIND THE  
FRONT, ONSHORE FLOW WILL AID IN CONTINUING THE RAIN AND HIGHER  
ELEVATION SNOW OVER PACIFIC NORTHWEST AND NORTHERN CALIFORNIA  
THROUGH SATURDAY, WITH HEAVY RAIN RETURNING TO THE PACIFIC  
NORTHWEST ON SATURDAY.  
 
MEANWHILE, UPPER-LEVEL ENERGY OVER PARTS OF THE SOUTHWEST/GREAT  
BASIN AND SOUTHERN ROCKIES/SOUTHERN HIGH PLAINS WILL MOVE  
NORTHEASTWARD TO THE UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES BY  
SATURDAY. MOISTURE WILL ALSO STREAM NORTHWARD OVER THE SOUTHERN  
PLAINS MOVING NORTHWARD TO THE UPPER MISSISSIPPI VALLEY BY  
SATURDAY MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER  
PARTS OF THE SOUTHERN ROCKIES/SOUTHERN HIGH PLAINS AND THE WESTERN  
GULF COAST THURSDAY NIGHT INTO FRIDAY MORNING. ON FRIDAY, THE  
SHOWERS AND THUNDERSTORMS WILL CONSOLIDATE OVER THE SOUTHERN  
PLAINS, CONTINUING OVER PARTS OF THE SOUTHERN PLAINS THROUGH  
SATURDAY. IN ADDITION, AS THE PLAINS AND MISSISSIPPI VALLEY  
MOISTEN UP, THE FRONT FROM THE NORTHWEST MOVES INTO THE  
NORTHERN/CENTRAL PLAINS AIDING IN DEVELOPING SHOWERS AND  
THUNDERSTORMS ALONG AND AHEAD OF THE BOUNDARY OVER PARTS OF THE  
CENTRAL/NORTHERN PLAINS EXPANDING INTO PARTS OF THE UPPER/MIDDLE  
MISSISSIPPI VALLEY BY SATURDAY.  
 
   
..MORE TO FOLLOW
 
 
ZIEGENFELDER  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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