609  
FXUS21 KWNC 022113  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EST FEBRUARY 02 2018  
 
SYNOPSIS: MID-LEVEL LOW PRESSURE IS LIKELY TO AFFECT THE EASTERN TWO-THIRDS OF  
THE CONTIGUOUS U.S. OVER THE NEXT TWO WEEKS, WHILE MID-LEVEL HIGH PRESSURE IS  
ANTICIPATED NEAR THE WEST COAST. STORM ACTIVITY IS FORECAST TO WIND DOWN ACROSS  
THE PACIFIC NORTHWEST AND NORTHERN ROCKIES, BUT CONTINUE ACROSS PORTIONS OF THE  
EASTERN CONUS AT LEAST THROUGH THE 3-7 DAY PERIOD. AREAS OF SURFACE LOW  
PRESSURE ARE EXPECTED TO INFLUENCE THE ALEUTIANS, WESTERN MAINLAND ALASKA, AND  
THE SOUTHERN COAST, BUT NONE OF THESE SYSTEMS ARE ANTICIPATED TO MEET OR EXCEED  
HAZARDOUS CRITERIA. WEEK-2 IS LIKELY TO FEATURE A MOSTLY DRY PATTERN WITH  
SURFACE HIGH PRESSURE SYSTEMS MOVING SOUTHEAST OUT OF CANADA OVER THE CENTRAL  
AND EASTERN CONUS.  
 
HAZARDS  
 
HEAVY SNOW FROM EASTERN MISSOURI NORTHEASTWARD ACROSS MUCH OF THE OHIO VALLEY  
AND THE NORTHEAST, TUE-WED, FEB 6-7.  
 
HEAVY RAIN FOR PORTIONS OF THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS,  
NORTHERN ALABAMA, AND NORTHERN GEORGIA, TUE-WED, FEB 6-7.  
 
MUCH BELOW NORMAL TEMPERATURES FROM EASTERN MONTANA AND THE DAKOTAS TO WESTERN  
MICHIGAN, MON-THU, FEB 5-8.  
 
FLOODING LIKELY AND/OR OCCURRING IN WESTERN WASHINGTON.  
 
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR MUCH OF THE EASTERN HALF OF  
THE CONUS, SAT-SUN, FEB 10-11.  
 
SEVERE DROUGHT ACROSS PARTS OF CALIFORNIA, THE CENTRAL AND SOUTHERN  
INTERMOUNTAIN REGION, THE CENTRAL AND SOUTHERN ROCKIES, THE GREAT PLAINS, THE  
MIDDLE AND LOWER MISSISSIPPI VALLEY, THE SOUTHEAST, AND THE MID-ATLANTIC.  
 
DETAILED SUMMARY  
 
FOR MONDAY FEBRUARY 05 - FRIDAY FEBRUARY 09: BACK-TO-BACK SURFACE HIGH PRESSURE  
SYSTEMS ARE FORECAST TO INFLUENCE THE CENTRAL AND EASTERN CONUS DURING THIS  
PERIOD. NEAR THE LEADING EDGE OF THE SECOND OF THESE CONTINENTAL AIR MASSES, A  
STORM SYSTEM IS PREDICTED TO FORM, AND BRING PRECIPITATION TO EASTERN PORTIONS  
OF THE CONUS. THIS SYSTEM IS FORECAST TO BRING A SWATH OF SNOW (ABOUT 4-8  
INCHES) FROM EASTERN MISSOURI NORTHEASTWARD ACROSS MUCH OF THE OHIO VALLEY AND  
NORTHEAST, AND HEAVY RAIN (2-3 INCHES) TO PORTIONS OF THE LOWER MISSISSIPPI AND  
TENNESSEE VALLEYS, NORTHERN ALABAMA, AND NORTHERN GEORGIA, ON FEB 6-7. A RISK  
OF STRONG TO SEVERE THUNDERSTORMS EXISTS ACROSS THE LOWER MISSISSIPPI VALLEY,  
BUT UNCERTAINTY ON THE MAGNITUDE OF INSTABILITY PRECLUDES A MAP DESIGNATION.  
THIS PATTERN ALSO FAVORS MUCH BELOW NORMAL TEMPERATURES (12 TO 16 DEGREES F  
BELOW NORMAL) FROM EASTERN MONTANA AND THE DAKOTAS TO WESTERN MICHIGAN, FEB 5-8.  
 
HEAVY PRECIPITATION FROM THE RECENT ONSLAUGHT OF NORTH PACIFIC CYCLONES HAS  
RESULTED IN LIKELY AND ONGOING FLOODING AREAS IN WESTERN WASHINGTON STATE.  
 
FOR ALASKA, SEVERAL FRONTAL SYSTEMS ARE EXPECTED TO INFLUENCE THE ALEUTIANS,  
THE ALASKA PENINSULA, THE WESTERN MAINLAND, AND THE SOUTH COAST DURING THIS  
PERIOD. HOWEVER, NONE OF THE WEATHER PARAMETERS ASSOCIATED WITH THESE CYCLONIC  
SYSTEMS ARE EXPECTED TO MEET OR EXCEED HAZARDOUS CRITERIA.  
 
FOR SATURDAY FEBRUARY 10 - FRIDAY FEBRUARY 16: MID-LEVEL CIRCULATION PATTERNS  
PRESENT IN DAYS 3-7 ARE LIKELY TO PERSIST THROUGH WEEK-2. THE GFS AND ECMWF  
ENSEMBLE MEAN SOLUTIONS CONTINUE TO DIVERGE IN WEEK-2, HOWEVER, WITH THE ECMWF  
BEING MORE PROGRESSIVE OVERALL, AND THUS MILDER OVER THE EASTERN CONUS. A  
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES IS DEPICTED FOR MUCH OF THE  
EASTERN HALF OF THE CONUS (BY THE GEFS), WHERE ENHANCED ODDS (20 PERCENT) OF  
MINIMUM TEMPERATURES BELOW THE 15TH CLIMATOLOGICAL PERCENTILE ARE FORECAST FOR  
TWO OR MORE DAYS. IT IS THOUGHT THAT THE ECMWF ENSEMBLE MEAN SOLUTION MAY BE  
WARMING UP THE EASTERN CONUS TOO QUICKLY.  
 
ANOMALOUS RIDGING IS FORECAST TO REMAIN INTACT OVER THE WESTERN CONUS, WITH  
MUCH ABOVE NORMAL TEMPERATURES EXPECTED DURING THE WEEK-2 PERIOD OVER THE AREA.  
WHILE THIS IS NOT DEPICTED ON THE MAP DUE TO THE COOL CLIMATOLOGY, THERE  
APPEARS TO BE DRAMATICALLY INCREASED ODDS OF RECORD HIGH TEMPERATURES, CENTERED  
OVER CALIFORNIA AND THE SOUTHWEST. WARMER TEMPERATURES COUPLED WITH ANOMALOUSLY  
LOW SOIL MOISTURE VALUES AND ANOMALOUS OFFSHORE FLOW, FAVOR AN ELEVATED FIRE  
WEATHER RISK DURING WEEK-2.  
 
THE U.S. DROUGHT MONITOR, VALID ON JANUARY 30, 2018 INDICATES A SUBSTANTIAL  
INCREASE IN THE COVERAGE OF SEVERE TO EXCEPTIONAL DROUGHT (D2-D4) FROM 13.60%  
LAST WEEK TO 17.21% THIS WEEK. DRYNESS AND DROUGHT HAVE INCREASED IN SPATIAL  
COVERAGE AND/OR INTENSIFIED OVER PORTIONS OF CALIFORNIA AND THE SOUTHWEST THIS  
WEEK. SOME DETERIORATION IN CONDITIONS IS ALSO NOTED OVER THE SOUTHERN PLAINS.  
 
FORECASTER: ANTHONY ARTUSA  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page