993  
FXUS01 KWBC 060759  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
258 AM EST SAT JAN 06 2018  
 
VALID 12Z SAT JAN 06 2018 - 12Z MON JAN 08 2018  
 
...WELL BELOW NORMAL TEMPERATURES TO CONTINUE ACROSS THE EASTERN  
THIRD OF THE NATION...  
 
...FREEZING RAIN LIKELY TO SPREAD FROM EASTERN KANSAS INTO  
SECTIONS OF THE GREAT LAKES AND OHIO/TENNESSEE VALLEYS...  
 
...HEAVY PRECIPITATION POSSIBLE OVER WESTERN WASHINGTON LATE IN  
THE WEEKEND...  
 
THE LATEST ARCTIC SURGE HAS BROUGHT ANOTHER ROUND OF WELL BELOW  
NORMAL TEMPERATURES TO MOST LOCATIONS EAST OF THE MISSISSIPPI  
RIVER. THE MOST ANOMALOUS DEPARTURES FROM CLIMATOLOGY SHOULD  
RESIDE ACROSS THE GREAT LAKES, OHIO VALLEY, CENTRAL/NORTHERN  
APPALACHIANS, AND OVER THE NORTHEASTERN UNITED STATES. THIS  
AFTERNOON, HIGH TEMPERATURES WILL LIKELY BE AROUND 20 TO 30  
DEGREES BELOW AVERAGE OVER THESE LOCATIONS WHICH SUPPORTS A NUMBER  
OF DAILY TEMPERATURE RECORDS BEING BROKEN. EXPECTED HIGHS WILL BE  
IN THE SINGLE DIGITS ACROSS THE LOWER GREAT LAKES DOWN INTO OHIO.  
MEANWHILE, READINGS IN THE TEENS ARE LIKELY FROM WASHINGTON, D.C.  
UP TO NEW YORK CITY WITH SINGLE DIGITS UP INTO COASTAL NEW  
ENGLAND. BASED ON THE LATEST FORECASTS, OVERNIGHT TEMPERATURES  
SHOULD GO BELOW ZERO DEGREES OVER MOST OF NEW ENGLAND WITH PERHAPS  
EVEN SOME 5 TO 10 DEGREE NUMBERS ALL THE WAY INTO NORTH CAROLINA.  
SUFFICE TO SAY, IT WILL BE A BRUTALLY COLD WEEKEND BUT SOME RELIEF  
IS IN SIGHT HEADING INTO EARLY NEXT WEEK. UNTIL THEN, THE FRIGID  
TEMPERATURES ALOFT SHOULD KEEP LAKE EFFECT SNOW PRODUCTION GOING  
OVER THE GREAT LAKES ALTHOUGH AMOUNTS ARE MUCH LIGHTER THAN RECENT  
DAYS.  
 
A SERIES OF DISTURBANCES WILL PUSH INTO THE PACIFIC NORTHWEST  
DURING THE NEXT COUPLE OF DAYS WITH THE LEAD SYSTEM EXPECTED TO  
SPLIT INTO TWO WHILE DEPARTING INLAND. THIS INITIAL FEATURE SHOULD  
BRING LIGHT PRECIPITATION TO THE PACIFIC NORTHWEST AND INTO THE  
UPPER INTERMOUNTAIN WEST. A SEPARATE UPPER TROUGH TO THE SOUTH  
WILL ALSO BE SPREADING MODERATE RAIN AND SNOW TO THE SIERRA NEVADA  
RANGE ON SATURDAY. EVENTUALLY ALL OF THESE SUBTLE FEATURES SHOULD  
INTERACT ACROSS THE SOUTHERN/CENTRAL PLAINS ON SUNDAY AFTERNOON  
LEADING TO A MORE ORGANIZED SYSTEM. A PRONOUNCED FRONTAL ZONE WILL  
BE THE SITE FOR ACTIVE CONVECTION ACROSS THE CENTRAL GULF COAST  
WHERE 1 TO 2 INCH RAINFALL AMOUNTS ARE POSSIBLE OVER EASTERN  
LOUISIANA. ADDITIONALLY, ENOUGH LOW-LEVEL COLD AIR REMAINING FROM  
THE SERIES OF ARCTIC BLASTS WILL AFFORD A FREEZING RAIN RISK  
ANYWHERE FROM EASTERN KANSAS THROUGH THE MISSOURI VALLEY AND INTO  
MUCH OF ILLINOIS, INDIANA, AS WELL AS THE OHIO AND TENNESSEE  
VALLEYS. WHILE ONLY LIGHT ACCUMULATIONS ARE LIKELY, ANY TRACE  
AMOUNT OF ICE ON ROAD SURFACES COULD CAUSE ISSUES TO GROUND  
TRANSPORTATION ON SUNDAY INTO MONDAY.  
 
LATE IN THE WEEKEND, A MUCH MORE PRONOUNCED UPPER TROUGH TAKES  
SHAPE OVER THE EASTERN PACIFIC. PERSISTENT LOW-LEVEL SOUTHWESTERLY  
FLOW WILL USHER IN ABUNDANT MOISTURE INTO COASTAL WASHINGTON.  
VIGOROUS OROGRAPHIC LIFT SHOULD RESULT ACROSS THE SOUTH/SOUTHWEST  
FACING SLOPES OF THE OLYMPICS WHERE OVER 2 INCH PRECIPITATION  
AMOUNTS ARE LIKELY DURING A 24-HOUR TIME PERIOD ENDING MONDAY  
MORNING. MEANWHILE, SOME HIGHER ELEVATION SNOWS ARE EXPECTED  
ACROSS THE WASHINGTON CASCADES.  
 
WHILE THE EASTERN STATES REMAIN FRIGID FOR ANOTHER COUPLE OF DAYS,  
MILD CONDITIONS ARE IN THE FORECAST ACROSS THE WESTERN AND CENTRAL  
UNITED STATES. THE UPPER FLOW FLATTENING OUT AS PACIFIC ORIGIN  
SYSTEMS MOVE THROUGH WILL ENSURE A WARMER PERIOD AHEAD. WESTERLY  
FLOW ALONG THE LEE OF THE ROCKIES WILL LEAD TO SUFFICIENT  
DOWNSLOPING ACROSS THE GREAT PLAINS AS HIGHS SOAR INTO THE 40S AS  
FAR NORTH AS SOUTH DAKOTA ON SUNDAY. ALSO, TEMPERATURES OVER THE  
UPPER MIDWEST ARE LIKELY GOING TO BE 20 DEGREES WARMER ON SUNDAY  
THAN THE PREVIOUS DAY AS READINGS FINALLY MOVE INTO THE MID/UPPER  
20S.  
 
RUBIN-OSTER  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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