644  
FXUS01 KWBC 061947  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
246 PM EST WED DEC 06 2017  
 
VALID 00Z THU DEC 07 2017 - 00Z SAT DEC 09 2017  
 
...HEAVY LAKE EFFECT SNOW LIKELY TO CONTINUE FOR A FEW DAYS  
DOWNWIND FROM THE GREAT LAKES...  
 
...ACCUMULATING SNOWFALL POSSIBLE ACROSS PARTS OF SOUTHWEST TEXAS  
WITH HEAVY RAIN POSSIBLE FROM THE SOUTHERN PLAINS TO THE  
SOUTHEAST...  
 
...CRITICAL TO EXTREME FIRE WEATHER CONDITIONS EXPECTED TO PERSIST  
ACROSS PORTIONS OF SOUTHERN CALIFORNIA...  
 
COLD AIR MOVING OVER THE STILL RELATIVELY WARM LAKES WILL ALLOW  
FOR MODERATE TO LOCALLY HEAVY LAKE EFFECT SNOWFALL TO CONTINUE  
DOWNWIND OF THE GREAT LAKES THROUGH THE REST OF THE WEEK. WINTER  
STORM WARNINGS, ADVISORIES, AND LAKE EFFECT SNOW WARNINGS ARE IN  
EFFECT AND SNOWFALL TOTALS OVER THE TWO DAY PERIOD COULD BE AS  
HIGH AS 10 TO 15 INCHES, ESPECIALLY FOR THOSE LOCATIONS  
IMMEDIATELY DOWNWIND OF LAKES ONTARIO AND ERIE.  
 
A DEEP UPPER-LEVEL TROUGH EXTENDING ACROSS MUCH OF THE U.S. EAST  
OF THE ROCKIES WILL KEEP THE CHILLY TEMPERATURES AROUND FOR AT  
LEAST THE NEXT COUPLE OF DAYS. PARTICULARLY ACROSS PARTS OF THE  
SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY, AFTERNOON HIGHS MAY  
BE AS MUCH AS 15 TO 30 DEGREES BELOW NORMAL. THESE COLD  
TEMPERATURES COMBINED WITH ENERGY ALOFT MOVING INTO THE SOUTHERN  
PLAINS MAY ALSO BRING THE POSSIBILITY FOR ACCUMULATING SNOWFALL  
OVERNIGHT TONIGHT AND INTO TOMORROW MORNING FOR PORTIONS OF  
SOUTHWEST TEXAS. WINTER STORM WARNINGS AND WINTER WEATHER  
ADVISORIES ARE IN EFFECT FOR THIS REGION WHERE 2 TO 6 INCHES OF  
SNOW IS FORECAST. TO THE EAST, A LINGERING AND SLOW TO MOVE  
FRONTAL BOUNDARY ACROSS THE NORTHERN GULF OF MEXICO WILL ALLOW FOR  
MODERATE TO HEAVY RAINFALL TO CONTINUE ACROSS PORTIONS OF THE  
SOUTHERN PLAINS, THE GULF COAST, AND INTO THE SOUTHEAST THURSDAY  
AND FRIDAY. ON FRIDAY, A SURFACE LOW DEVELOPING ALONG THE FRONT  
WOULD HELP TO DRAW IN ADDITIONAL COLD AIR ACROSS THE SOUTHEAST  
WHICH MAY ALLOW FOR RAINFALL ON THE BACK EDGE OF THIS  
PRECIPITATION SHIELD TO CHANGE OVER TO SNOW. AT THIS TIME,  
APPRECIABLE ACCUMULATION IS NOT LIKELY, BUT THE CHANCE FOR  
SNOWFLAKES ACROSS PARTS OF THE SOUTHEAST AND EVENTUALLY INTO THE  
MID-ATLANTIC ARE NOT OUT OF THE QUESTION AS THE LOW MOVES WELL OFF  
THE ATLANTIC COASTLINE.  
 
FINALLY, AMPLIFIED UPPER-LEVEL RIDGING ACROSS THE WESTERN U.S.  
WILL KEEP ABOVE NORMAL TEMPERATURES AND DRY WEATHER IN THE  
FORECAST THROUGH THE SHORT RANGE PERIOD. GUSTY WINDS COMBINED WITH  
THE WARM AND DRY AIRMASS WILL KEEP DANGEROUS FIRE WEATHER  
CONDITIONS ELEVATED ACROSS PARTS OF SOUTHERN CALIFORNIA. WILDFIRES  
ACROSS THIS REGION ARE ONGOING AND A CRITICAL TO EXTREME RISK IS  
EXPECTED TO CONTINUE THROUGH THE REST OF THE WEEK. REG FLAG AND  
HIGH WIND WARNINGS ARE IN EFFECT ACROSS THIS REGION, WHICH  
INCLUDES THE LOS ANGELES METRO AND SURROUNDING AREAS. PLEASE  
MONITOR PRODUCTS ISSUED BY THE LOCAL OFFICES IN THOSE REGIONS FOR  
ADDITIONAL INFORMATION.  
 
SANTORELLI  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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