837  
FXUS01 KWBC 050740  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
239 AM EST FRI JAN 05 2018  
 
VALID 12Z FRI JAN 05 2018 - 12Z SUN JAN 07 2018  
 
...AN ARCTIC OUTBREAK WILL KEEP TEMPERATURES 20 TO 30 DEGREES  
BELOW AVERAGE ACROSS THE NORTHEASTERN U.S...  
 
...WET CONDITIONS EXPECTED FROM NORTHERN CALIFORNIA INTO THE  
PACIFIC NORTHWEST...  
 
...A THREAT FOR ACCUMULATING ICE IS LIKELY OVER INTERIOR  
WASHINGTON/OREGON...  
 
EARLY THIS MORNING, A POWERFUL NOR'EASTER WAS LIFTING INTO NOVA  
SCOTIA SPREADING HEAVY SNOW AND INTENSE WIND FIELDS TO FAR EASTERN  
CANADA. WHILE CONDITIONS HAVE BEGUN TO IMPROVE ACROSS THE  
NORTHEASTERN U.S., THE ARCTIC SURGE IS ALREADY UNDERWAY  
ACCOMPANIED BY BRISK WINDS AT TIMES. DANGEROUSLY LOW WIND CHILL  
TEMPERATURES ARE TO BE EXPECTED THE NEXT COUPLE OF DAYS WITH SOME  
BLOWING SNOW POSSIBLE. THE CURRENT NATIONAL WEATHER SERVICE  
HAZARDS MAP FEATURES A COMBINATION OF WIND CHILL ADVISORIES AND  
WARNINGS EXTENDING FROM THE UPPER MIDWEST ACROSS THE GREAT  
LAKES/OHIO VALLEY AND FROM THE CAROLINAS NORTHWARD. FORECAST HIGH  
TEMPERATURES THROUGH SATURDAY WILL STRUGGLE TO GET ABOVE THE  
SINGLE DIGITS ACROSS THE UPPER MIDWEST, GREAT LAKES,  
CENTRAL/NORTHERN APPALACHIANS, AND MUCH OF NEW ENGLAND. THIS  
EASILY REACHES THE 20 TO 30 DEGREE BELOW CLIMATOLOGY RANGE WHICH  
SUPPORTS A CHANCE FOR MANY DAILY TEMPERATURE RECORDS TO BE BROKEN.  
FRIGID TEMPERATURES ALSO EXTEND DOWN INTO THE SOUTHERN U.S. AS  
LOWS PLUNGE INTO THE 20S DOWN ALONG THE EASTERN GULF COAST AND  
INTO CENTRAL FLORIDA. MANY DAILY RECORDS MAY BE BROKEN ACROSS THIS  
SECTOR OF THE COUNTRY AS WELL.  
 
THE PERSISTENT SHOTS OF ARCTIC AIR WILL PROVIDE FURTHER CHANCES  
FOR LAKE EFFECT SNOWS INTO THE WEEKEND. EXTREMELY COLD  
TEMPERATURES ALOFT MOVING OVER MANY UNFROZEN LAKE SURFACES WILL  
FOSTER THE DEVELOPMENT OF WIDESPREAD SNOW SHOWERS OVER ALL THE  
MAJOR GREAT LAKES. PER RECENT OBSERVATIONS, JUST UNDER A QUARTER  
OF THE LAKES ARE FROZEN, PARTICULARLY THE WESTERN SECTION OF LAKE  
ERIE. BASED ON THE LATEST FORECAST, THE HEAVIEST SNOW IS EXPECTED  
TO BE SOUTHEAST OF LAKE ONTARIO WITH 6 TO 10 INCH AMOUNTS  
POSSIBLE. THIS WOULD AFFECT AREAS ANYWHERE FROM ROCHESTER TO  
SYRACUSE, NEW YORK.  
 
A BROAD UPPER TROUGH ACROSS THE EASTERN PACIFIC WILL PUSH TOWARD  
THE PACIFIC NORTHWEST INCREASING THE THREAT FOR COASTAL RAINS AND  
HIGHER ELEVATION SNOWS. MULTIPLE DISTURBANCES MOVING INLAND WILL  
ACT TO KEEP WET CONDITIONS IN PLACE WITH A BROAD AREA OF 1 TO 2  
INCHES OF PRECIPITATION EXPECTED ACROSS THE WASHINGTON CASCADES.  
DURING THE NEXT COUPLE OF DAYS, MANY MOUNTAIN RANGES OVER THE  
WESTERN U.S. SHOULD SEE ACCUMULATING SNOWS WITH THE HIGHEST  
AMOUNTS LIKELY OVER THE COLORADO ROCKIES WITH THE POTENTIAL FOR  
OVER A FOOT. MEANWHILE, MARITIME FLOW OVERRIDING A SUB-FREEZING  
SURFACE LAYER SHOULD MAKE CONDITIONS FAVORABLE FOR FREEZING RAIN  
ACROSS SECTIONS OF CENTRAL/EASTERN WASHINGTON DOWN INTO EASTERN  
OREGON.  
 
WHILE THE EASTERN STATES WILL CONTINUE TO BE IMPACTED BY ANOTHER  
ARCTIC SURGE, MILD CONDITIONS ARE LIKELY FROM THE FOUR CORNERS  
NORTHWARD ALONG THE HIGH PLAINS. DOWNSLOPING FLOW IS FORECAST TO  
BRING WELL ABOVE NORMAL TEMPERATURES FOR THESE LOCATIONS INTO THE  
WEEKEND. BY SATURDAY, EXPECT HIGHS TO REACH THE UPPER 40S UP INTO  
THE BLACK HILLS WHICH WOULD BE AROUND 15 TO 20 DEGREES ABOVE  
CLIMATOLOGY. HOWEVER, HEADING EAST AWAY FROM THE DOWNSLOPING  
REGIME WILL BRING READINGS BACK INTO THE TEENS ON THE FAR EASTERN  
SIDE OF THE NORTHERN PLAINS.  
 
RUBIN-OSTER  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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