739  
FXUS01 KWBC 141956  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
256 PM EST WED NOV 14 2018  
 
VALID 00Z THU NOV 15 2018 - 00Z SAT NOV 17 2018  
 
...AN EARLY-SEASON WINTER STORM TO BRING ICE AND SNOW FROM THE  
MIDWEST/OHIO VALLEY TO THE APPLACHIANS AND INTERIOR NORTHEAST  
THROUGH FRIDAY...  
 
...HEAVY RAIN EXPECTED OVER THE SOUTHEAST AND PARTS OF THE  
MID-ATLANTIC REGION WEDNESDAY AND THURSDAY...  
 
...CONTINUED FIRE WEATHER CONCERNS FOR SOUTHERN  
CALIFORNIA...THOUGH SLOW IMPROVEMENT LIKELY BY THE END OF THE  
WEEK...  
 
A SIGNIFICANT STORM IS TAKING SHAPE OVER THE LOWER MISSISSIPPI  
VALLEY AND IS EXPECTED TO IMPACT SECTIONS OF THE CENTRAL AND  
EASTERN U.S. WITH AN EARLY-SEASON BOUT OF WINTER WEATHER THROUGH  
FRIDAY. THROUGH WEDNESDAY EVENING AND THURSDAY MORNING, A DEEP  
UPPER-LEVEL LOW MOVING ACROSS THE TENNESSEE AND MISSISSIPPI  
VALLEYS WILL BRING ACCUMULATING SNOW FROM EASTERN MISSOURI ACROSS  
CENTRAL AND SOUTHERN ILLINOIS AND SECTIONS OF WESTERN INDIANA AND  
WESTERN KENTUCKY. THE HEAVIEST AMOUNTS...UPWARDS OF 4-7 INCHES  
ARE EXPECTED OVER SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS, WHERE  
WINTER STORM WARNINGS ARE IN EFFECT. FARTHER EAST, MOISTURE FROM  
THE GULF OF MEXICO SPREADING NORTHWARD AHEAD OF THIS UPPER LOW  
WILL ENCOUNTER A COLD AIR MASS IN PLACE OVER THE APPALACHIANS  
TONIGHT THROUGH THURSDAY. AT THE SAME TIME, A SURFACE LOW FORMING  
ALONG THE CAROLINA COAST WILL STRENGTHEN AND MOVE NORTHWARD ALONG  
THE COAST, CAUSING A WINTRY MIX OF SNOW, SLEET AND FREEZING RAIN  
TO BREAK OUT OVER THE SOUTHERN/CENTRAL APPALACHIANS OVERNIGHT AND  
CONTINUE THROUGH MUCH OF THURSDAY AS THE COLD AIR WILL BE TOUGH TO  
SCOUR OUT. THE MAIN IMPACT FOR THIS REGION WILL BE SLEET AND  
FREEZING RAIN, WHERE THERE IS THE POTENTIAL FOR UP TO .25 INCH OF  
ICE OVER THE SHENANDOAHS AND LAUREL HIGHLANDS. WINTER STORM  
WATCHES AND WARNINGS ARE POSTED ACROSS THIS REGION.  
 
AS THE LOW MOVES UP THE EAST COAST THURSDAY THROUGH FRIDAY, A  
WINTRY MIX OF PRECIPITATION WILL SPREAD ACROSS THE NORTHERN  
APPALACHIANS/MID-ATLANTIC STATES AND INTO THE NORTHEAST.  
PRECIPITATION ACROSS INTERIOR SECTIONS WILL MOSTLY BE SNOW AND  
SLEET, WITH A LARGE SWATH OF UP TO 4-8 INCHES ACCUMULATION BY THE  
TIME THE STORM DEPARTS ON FRIDAY. ALONG THE I-95 CORRIDOR FROM  
WASHINGTON, D.C. TO BOSTON, PRECIPITATION ON THURSDAY MAY START  
OUT AS A PERIOD OF SNOW, SLEET OR LIGHT FREEZING RAIN AND MAY  
CAUSE TRAVEL PROBLEMS BEFORE CHANGING OVER TO RAIN AS TEMPERATURES  
SLOWLY WARM. WITH THE EXCEPTION OF NORTHERN MAINE, PRECIPITATION  
SHOULD MOSTLY WIND DOWN BY LATER FRIDAY AFTERNOON.  
 
EAST OF THE WINTRY PRECIPITATION, MODERATE TO HEAVY RAINS ARE  
LIKELY FROM THE SOUTHEAST THROUGH COASTAL SECTIONS OF THE  
MID-ATLANTIC AND NORTHEAST THROUGH EARLY FRIDAY. RAINFALL TOTALS  
WILL RANGE FROM 1-2 INCHES OVER THIS REGION, WITH LOCALLY HEAVIER  
AMOUNTS POSSIBLE AS ATLANTIC MOISTURE WRAPS INTO THE STRENGTHENING  
SURFACE LOW. AS A RESULT, A SLIGHT RISK OF EXCESSIVE  
RAINFALL/FLASH FLOODING IS IN EFFECT FROM CENTRAL GEORGIA INTO  
WESTERN SOUTH CAROLINA THROUGH THURSDAY MORNING. DURING THURSDAY  
AND THURSDAY NIGHT, A MARGINAL RISK OF EXCESSIVE RAINFALL EXTENDS  
FROM THE NORTH CAROLINA COAST NORTHWARD THROUGH LONG ISLAND.  
 
IT APPEARS THAT THE STRONG SANTA ANA WINDS WILL FINALLY BEGIN TO  
SUBSIDE DURING THE NEXT FEW DAYS. EVEN SO, THE STORM PREDICTION  
CENTER MAINTAINS AN ELEVATED FIRE WEATHER RISK THROUGH THURSDAY AS  
RELATIVE HUMIDITIES REMAIN LOW AND OFFSHORE FLOW CONTINUES. BY  
THIS WEEKEND, THE FLOW WILL START TO TURN MORE ONSHORE, LESSENING  
THE RISK FURTHER.  
 
KLEIN  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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