564  
FXUS01 KWBC 161953  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
252 PM EST SAT DEC 16 2017  
 
VALID 00Z SUN DEC 17 2017 - 00Z TUE DEC 19 2017  
   
..PATTERN CHANGE EXPECTED OVER THE WEEKEND
 
 
A STRONG UPPER-LEVEL TROUGH IS BREAKING DOWN THE RIDGE ACROSS THE  
WEST WHILE FLATTENING THE TROUGH OVER THE EAST. PRECIPITATION WILL  
PRIMARILY FALL FROM THE WASHINGTON COAST TO THE CASCADES...  
SNOWFALL WILL BE HEAVY OVER THE CASCADES. ACCUMULATING SNOW IS  
EXPECTED FOR THE NORTHERN ROCKIES  
IN RESPONSE TO A DEVELOPING SURFACE LOW OVER THE FOUR-CORNERS  
REGION AND SHORTWAVE ENERGY ALOFT.  
 
DEEPER MOISTURE RETURNING NORTHWARD FROM THE GULF OF MEXICO AHEAD  
OF THE FRONT COULD FUEL THE DEVELOPMENT OF SOME SCATTERED  
THUNDERSTORMS, ALONG WITH LOCALLY HEAVY RAINFALL AT TIMES. AT THIS  
TIME, EASTERN TEXAS AND NORTHWEST LOUISIANA WILL BE WHERE THE AXIS  
OF HIGHEST RAINFALL SETUPS- WITH DAILY AREAL AVERAGES OF 1 TO 2  
INCHES FORECAST THROUGH TUESDAY. A MARGINAL RISK FOR FLASH  
FLOODING HAS BEEN IDENTIFIED FOR PORTIONS OF TEXAS AND LOUISIANA  
THROUGH MONDAY MORNING.  
 
LIGHT PRECIPITATION WILL SPREAD ACROSS THE NORTHERN-TIER STATES AS  
A SURFACE FRONT PASSES THROUGH SOUTHERN CANADA AND THE NORTHERN  
HIGH PLAINS. AREAS DOWNWIND OF THE GREAT LAKES WILL HAVE SNOW THAT  
IS SOMEWHAT ENHANCED BY LAKES, BUT NOT LIKE IT HAS BEEN THIS PAST  
WEEK.  
 
WARM AND DRY CONDITIONS ARE EXPECTED FOR FLORIDA AND THE LOWER  
ELEVATIONS OF THE DESERT SOUTHWEST AND INTO CENTRAL AND SOUTHERN  
CALIFORNIA THIS WEEKEND. FIRE WEATHER CONCERNS WILL STILL EXIST  
ACROSS PARTS OF CALIFORNIA OWING TO THE DRY CONDITIONS AND GUSTY  
WINDS.  
 
CAMPBELL  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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