626  
FXUS01 KWBC 041944  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
244 PM EST MON FEB 04 2019  
 
VALID 00Z TUE FEB 05 2019 - 00Z THU FEB 07 2019  
 
...HEAVY RAIN AND THREATS FOR FLASH FLOODING CONTINUE FOR PORTIONS  
OF CALIFORNIA TONIGHT...  
 
...HEAVY SNOW LIKELY OVER MOUNTAINOUS REGIONS FROM THE SIERRAS TO  
THE CENTRAL ROCKIES...  
 
...WINTRY MIX EXPECTED FOR PORTIONS OF THE MIDWEST AND GREAT LAKES  
TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON...  
 
...TEMPERATURES WILL BE WELL BELOW AVERAGE FROM MONTANA INTO THE  
DAKOTAS AND WELL ABOVE AVERAGE FROM THE SOUTHERN PLAINS TO THE  
EAST COAST...  
 
A HIGHLY ACTIVE PATTERN WILL CONTINUE ACROSS THE LOWER 48 EARLY  
THIS WEEK WITH A SERIES OF STORM SYSTEMS IMPACTING LOCATIONS WEST  
OF THE CONTINENTAL DIVIDE BRINGING SNOW FOR THE MOUNTAINS AND  
LOWER ELEVATIONS OF THE INTERMOUNTAIN WEST ALONG WITH LOWER  
ELEVATION RAIN. HEAVY RAIN WITH THE POTENTIAL FOR FLASH FLOODING  
WILL CONTINUE TO BE A CONCERN THROUGH EARLY TONIGHT ACROSS RECENT  
BURN SCAR LOCATIONS OF NORTHERN CALIFORNIA ALONG WITH THE  
TRANSVERSE RANGES OF SOUTHERN CALIFORNIA. WHILE RAINFALL  
INTENSITIES MAY NOT BE AS HIGH ACROSS SOUTHERN CALIFORNIA AS IN  
RECENT DAYS, MUCH OF THE AREA HAS RECEIVED 200 TO 400 PERCENT OF  
THEIR NORMAL PRECIPITATION OVER THE PAST SEVEN DAYS WHICH HAS LEFT  
PORTIONS OF THE AREA SUSCEPTIBLE TO RUNOFF DUE TO HEAVY RAIN.  
 
AS A PAIR OF COLD FRONTS MOVE ACROSS THE WESTERN U.S. OVER THE  
NEXT TWO DAYS, SNOW LEVELS WILL FALL ALLOWING TEMPERATURES TO  
SUPPORT SNOW ACROSS LOWER ELEVATIONS OF NORTHERN CALIFORNIA AND  
MUCH OF OREGON AS WELL AS MUCH OF THE INTERMOUNTAIN WEST BY  
TUESDAY AFTERNOON. SNOW WILL BE MEASURED IN FEET ACROSS THE SIERRA  
NEVADA MOUNTAINS AND PORTIONS OF THE WASATCH RANGE, WITH LOCALLY  
HEAVY SNOW ALSO EXPECTED INTO THE CENTRAL TO NORTHERN ROCKY  
MOUNTAINS. DUE TO THE MAGNITUDE OF COLD AIR EXPECTED ACROSS THE  
INTERMOUNTAIN WEST, MANY LOWER ELEVATION LOCATIONS WILL SEE AT  
LEAST LIGHT SNOW OVER THE NEXT TWO DAYS.  
 
ARCTIC AIR WILL STAY ENTRENCHED ACROSS THE NORTHERN PLAINS INTO  
MUCH OF MONTANA THROUGH THE MIDDLE OF THE WEEK WITH TEMPERATURES  
RANGING 20 TO 40 DEGREES BELOW AVERAGE. SUB-FREEZING TEMPERATURES  
WILL ALSO EXTEND INTO NORTHERN PORTIONS OF THE UPPER GREAT LAKES  
REGION. AHEAD OF A SURFACE LOW/COLD FRONT TRACKING THROUGH THE  
GREAT LAKES, TOTAL ACCUMULATIONS OF A QUARTER TO A HALF INCH OF  
FREEZING RAIN ARE EXPECTED BY THIS EVENING FROM NORTHERN WISCONSIN  
INTO THE U.P. OF MICHIGAN. COLDER TEMPERATURES WILL FILTER IN  
BEHIND THE COLD FRONT SUPPORTING A THREAT FOR A WINTRY MIX OF SNOW  
FOR THE UPPER MISSISSIPPI VALLEY AND FREEZING RAIN FOR PORTIONS OF  
THE MIDWEST AND LOWER GREAT LAKES LATE TUESDAY INTO WEDNESDAY,  
WITH ALL RAIN CLOSER TO THE OHIO VALLEY. ICE ACCUMULATIONS BETWEEN  
0.10-0.20" ARE EXPECTED ACROSS PORTIONS OF THE LOWER GREAT LAKES  
INCLUDING CHICAGO AND QUAD CITIES, IL METRO AREAS. POTENTIAL  
EXISTS FOR SIGNIFICANT FREEZING RAIN AND ICE ACCUMULATIONS (0.25")  
ACROSS SOUTHERN MICHIGAN, INCLUDING THE DETROIT METRO AREA.  
 
BY WEDNESDAY, ANOTHER WAVE OF LOW PRESSURE WILL EJECT INTO THE  
SOUTHERN PLAINS UNDERNEATH THE STRONG ARCTIC HIGH IN SOUTHERN  
CANADA. THIS WILL LEAD TO AN AREA OF SNOW ACROSS THE NORTHERN AND  
CENTRAL PLAINS, AS WELL AS PARTS OF THE UPPER MIDWEST BY LATE  
WEDNESDAY. MEANWHILE, HEAVY RAIN WILL BE POSSIBLE ALONG A  
STATIONARY FRONT IN THE OHIO AND TENNESSEE VALLEYS.  
 
SNELL  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 

 
 
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