926  
FXUS21 KWNC 302107  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EST JANUARY 30 2018  
 
SYNOPSIS: A MID-LEVEL TROUGH IS LIKELY TO AFFECT THE EASTERN TWO-THIRDS OF THE  
CONTINENTAL U.S. OVER THE NEXT TWO WEEKS, WHILE AN MID-LEVEL HIGH PRESSURE  
CENTER IS FORECAST OFF THE WESTERN COAST. SEVERAL SURFACE LOW PRESSURE SYSTEMS  
ARE EXPECTED TO BRING FRONTAL ACTIVITY TO THE PACIFIC NORTHWEST AND ROCKIES, AS  
WELL AS THE GULF COAST REGION DURING DAYS 3-7. WEEK-2 IS LIKELY TO BE A MOSTLY  
DRY PATTERN WITH SURFACE HIGH PRESSURE SYSTEMS MOVING SOUTH OUT OF CANADA OVER  
THE CENTRAL AND EASTERN U.S. ALASKAS MID-LEVEL PATTERN IS ALSO PREDICTED TO  
REMAIN SIMILARLY STATIONARY DURING THIS PERIOD, WITH A SERIES OF LOW PRESSURE  
SYSTEMS OVER THE ALEUTIAN ISLANDS AND RIDGING IN THE NORTHERN PART OF THE  
STATE, AS WELL AS THE PANHANDLE.  
 
HAZARDS  
 
HEAVY RAIN ACROSS PORTIONS OF THE PACIFIC NORTHWEST, FRI-MON, FEB 2-FEB 5.  
 
HEAVY RAIN ACROSS PORTIONS OF THE LOWER MISSISSIPPI VALLEY, SAT-SUN, FEB 3-FEB  
4.  
 
HEAVY SNOW ACROSS PORTIONS OF THE CASCADES, THE NORTHERN ROCKIES AND THE  
NORTHERN GREAT BASIN, FRI-MON, FEB 2-FEB 5.  
 
MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE NORTHEAST, THE NORTHERN  
PLAINS, AND THE GREAT LAKES, FRI-MON, FEB 2-FEB 5.  
 
MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE ALASKA PANHANDLE AND  
SOUTHEAST ALASKA, FRI-SAT, FEB 2-FEB 3.  
 
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR EASTERN HALF OF THE  
CONTINENTAL U.S., WED-TUE, FEB 7-FEB 13.  
 
MODERATE RISK OF MUCH BELOW NORMAL TEMPERATURES FOR PORTIONS OF THE CENTRAL  
PLAINS, THE MID-ATLANTIC, THE NORTHEAST, AND THE GREAT LAKES, WED-TUE, FEB  
7-FEB 13.  
 
SEVERE DROUGHT ACROSS THE CENTRAL PLAINS, THE CENTRAL ROCKIES, THE LOWER  
MISSISSIPPI VALLEY, THE CENTRAL GREAT BASIN, THE NORTHERN PLAINS, THE TENNESSEE  
VALLEY, THE SOUTHERN ROCKIES, THE MIDDLE MISSISSIPPI VALLEY, THE MID-ATLANTIC,  
THE SOUTHEAST, THE SOUTHERN PLAINS, AND THE SOUTHWEST.  
 
DETAILED SUMMARY  
 
FOR FRIDAY FEBRUARY 02 - TUESDAY FEBRUARY 06: A SERIES OF SURFACE HIGH PRESSURE  
SYSTEMS ARE FORECAST TO MOVE SOUTH OVER THE CENTRAL PLAINS THROUGHOUT THE WEEK,  
AFFECTING THE CENTRAL AND EASTERN CONUS. A SURFACE LOW PRESSURE SYSTEM IS  
LIKELY TO CAUSE SOME FRONTAL ACTIVITY AS IT MOVES FROM THE PACIFIC NORTHWEST  
EASTWARD ACROSS THE CONUS DURING FEB 3-5.  
 
MUCH BELOW-NORMAL TEMPERATURES ARE PREDICTED FOR THE NORTH CENTRAL PLAINS,  
GREAT LAKES AND NEW ENGLAND FROM FEB 2-5, DUE TO THE SERIES OF HIGH PRESSURE  
SYSTEMS CAUSING A SERIES OF COLD AIR OUTBREAKS FROM CANADA. MINIMUM  
TEMPERATURES 12 DEGREES F BELOW NORMAL OR COLDER ARE LIKELY DURING THIS PERIOD,  
WITH THE LOWEST MINIMUMS EXPECTED FOR FEB 4.  
 
THE PACIFIC NORTHWEST IS EXPECTED TO EXPERIENCE SEVERAL SHORTWAVE TROUGHS  
DURING THE BEGINNING OF THE PERIOD UNTIL MID-WEEK. HEAVY RAIN (EXCEEDING 1.5"  
IN 24 HOURS) IS LIKELY IN THE WESTERN PART OF WASHINGTON STATE, WITH HEAVY SNOW  
IN THE CASCADES (LIQUID EQUIVALENT EXCEEDING 1.5"). HEAVY SNOW IS ALSO LIKELY  
ACROSS THE NORTHERN ROCKIES WITH THE FIRST ACCUMULATIONS EXPECTED FEB 2-3 AND  
ANOTHER FRONTAL PASSAGE ON FEB 4-5 (LIQUID EQUIVALENT EXCEEDING 1.5"). HEAVY  
RAIN (EXCEEDING 1" IN 24 HOURS) IS FORECAST ALONG THE CENTRAL GULF COAST AND  
LOWER MISSISSIPPI RIVER VALLEY AS THE COLD FRONT ASSOCIATED WITH THE  
AFOREMENTIONED SURFACE LOW PRESSURE MOVES OVER THE REGION DURING FEB 3-4.  
 
FOR ALASKA, A FEW SURFACE LOW PRESSURE SYSTEMS ARE FORECAST TO MOVE THROUGH THE  
GULF OF ALASKA, AFFECTING THE SOUTHERN PART OF THE STATE. SOME PRECIPITATION IS  
LIKELY THROUGHOUT THE GULF COAST ON FEB 3-4, THOUGH IT IS EXPECTED TO REMAIN  
BELOW HAZARDOUS CONDITIONS. A SURFACE HIGH IS LIKELY TO REMAIN ENTRENCHED OVER  
THE NORTHERN HALF OF ALASKA THROUGH THE PERIOD. MUCH BELOW-NORMAL TEMPERATURES,  
LIKELY 20-30 DEGREES F NEGATIVE ANOMALIES, ARE EXPECTED IN THE PANHANDLE AND  
ALONG THE SOUTHERN GULF COAST FROM FEB 2-3. ADDITIONALLY, WITH THIS STRONG  
SURFACE HIGH, CONDITIONS APPEAR FAVORABLE FOR STRONG GAP WINDS OVER THE  
SOUTHERN PART OF THE STATE.  
 
FOR WEDNESDAY FEBRUARY 07 - TUESDAY FEBRUARY 13: MID-LEVEL PATTERNS PRESENT IN  
DAYS 3-7 ARE LIKELY TO PERSIST THROUGH WEEK-2. A MID-LEVEL TROUGH IS FORECAST  
TO REMAIN OVER THE GREAT LAKES AND NORTH CENTRAL PLAINS, BRINGING AN INFLUX OF  
ARCTIC AIR INTO THE CENTRAL AND EASTERN CONUS DURING WEEK-2. A SLIGHT RISK FOR  
MUCH BELOW-NORMAL TEMPERATURES IS POSTED FOR MUCH OF THE CONUS EAST OF THE  
CONTINENTAL DIVIDE FOR THE ENTIRE WEEK-2 PERIOD, WITH A MODERATE RISK FOR MUCH  
BELOW-NORMAL TEMPERATURES FOR THE CENTRAL PLAINS, GREAT LAKES AND NORTHEAST FOR  
FEB 7-11. THIS ARCTIC AIRMASS IS LIKELY TO REACH ITS FURTHEST SOUTHERN EXTENT  
ON FEB 10-11, RETREATING NORTHWARD TOWARD THE END OF THE PERIOD.  
 
THE CONTINENTAL US IS LIKELY TO REMAIN MOSTLY DRY OVER THE WEEK-2 PERIOD. THERE  
IS A POSSIBILITY OF FRONTAL ACTIVITY CAUSING SOME HEAVY PRECIPITATION OVER THE  
CENTRAL PLAINS MID-WEEK; HOWEVER, DISPARITY IN MODEL GUIDANCE LEAVES  
UNCERTAINTY IN THIS SYSTEM, SO CURRENTLY THERE ARE NO PRECIPITATION HAZARDS FOR  
WEEK-2 FOR THE CONUS.  
 
MID-LEVEL RIDGING OVER ALASKA IS EXPECTED TO REMAIN DURING THE WEEK-2 PERIOD.  
SURFACE HIGH PRESSURE IS FORECAST TO CONTINUE OVER MUCH OF MAINLAND ALASKA,  
LIKELY LEADING TO A QUIET PERIOD IN THIS REGION. A LOW PRESSURE SYSTEM IS  
FORECAST TO MOVE ALONG THE ALEUTIANS AND GULF COAST EARLY IN WEEK-2, BUT THE  
PRECIPITATION AMOUNTS FROM MODEL GUIDANCE DO NOT CURRENTLY MEET HAZARDOUS  
CRITERIA.  
 
THE U.S. DROUGHT MONITOR, VALID ON JANUARY 23, 2018 INDICATES AN INCREASE IN  
THE COVERAGE OF SEVERE TO EXCEPTIONAL DROUGHT (D2-D4) FROM 10.03% LAST WEEK TO  
13.60% THIS WEEK. SEVERE DROUGHT CONTINUED TO EXPAND ACROSS THE SOUTHERN GREAT  
PLAINS AND SOUTHWEST THIS PAST WEEK.  
 
FORECASTER: CHRISTINA FINAN  
 

 
 
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