610  
FXUS21 KWNC 112116  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EST JANUARY 11 2018  
 
SYNOPSIS: AT THE START OF THE HAZARDS PERIOD, SURFACE HIGH PRESSURE IS BRIEFLY  
FORECAST OVER THE EASTERN HALF OF THE CONTIGUOUS U.S. SHORTLY THEREAFTER, A  
COLD FRONT IS EXPECTED TO MOVE SOUTH OF THE CANADIAN BORDER INTO THE  
NORTH-CENTRAL U.S. THE ASSOCIATED SURFACE LOW PRESSURE CENTER IS PREDICTED TO  
MOVE ACROSS THE UPPER MIDWEST, THE LOWER GREAT LAKES REGION, AND THEN OFF THE  
NORTHEAST COAST, WITH CANADIAN SURFACE HIGH PRESSURE BUILDING IN BEHIND THIS  
STORM SYSTEM. BY THE END OF THE 3-7 DAY PERIOD, ANOTHER FRONTAL SYSTEM IS  
ANTICIPATED TO MOVE ACROSS THE PACIFIC NORTHWEST AND NORTHERN INTERMOUNTAIN  
REGION. MULTIPLE LOW PRESSURE SYSTEMS OVER THE ALASKA DOMAIN ARE EXPECTED TO  
MAINTAIN INCLEMENT WEATHER CONDITIONS ACROSS MOST OF THE STATE DURING THIS  
TIME. DURING THE WEEK-2 PERIOD, THE OVERALL CIRCULATION PATTERN IS FORECAST TO  
BE PROGRESSIVE AND SOMEWHAT LESS AMPLIFIED AS UPPER-LEVEL LOW PRESSURE OVER THE  
EASTERN CONTIGUOUS U.S. WEAKENS AND UPPER-LEVEL HIGH PRESSURE WEAKENS OVER THE  
INTERIOR WEST.  
 
HAZARDS  
 
PERIODS OF MUCH BELOW NORMAL TEMPERATURES FOR MOST OF THE CENTRAL AND EASTERN  
CONUS, SUN-THU, JAN 14-18.  
 
PERIODS OF HEAVY PRECIPITATION FOR THE PACIFIC NORTHWEST AND NORTHWESTERN  
CALIFORNIA, TUE-WED, JAN 16-17.  
 
HEAVY PRECIPITATION FOR THE SOUTH COAST OF ALASKA FROM THE ALASKA PENINSULA  
THROUGH THE SOUTHEAST PANHANDLE, SUN, JAN 14.  
 
HIGH WINDS FOR THE SOUTH COAST OF ALASKA FROM THE ALASKA PENINSULA THROUGH THE  
SOUTHEAST PANHANDLE, SUN, JAN 14.  
 
HIGH SIGNIFICANT WAVE HEIGHTS FOR THE SOUTH COAST OF ALASKA FROM THE ALASKA  
PENINSULA THROUGH THE SOUTHEAST PANHANDLE, SUN, JAN 14.  
 
MUCH ABOVE NORMAL TEMPERATURES FOR PARTS OF SOUTHERN MAINLAND ALASKA, SUN-TUE,  
JAN 14-16.  
 
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR MUCH OF THE MID-ATLANTIC AND  
SOUTHERN ATLANTIC COAST STATES, AND ADJACENT PORTIONS OF THE CENTRAL AND  
SOUTHERN APPALACHIANS, FRI, JAN 19.  
 
SLIGHT RISK OF HEAVY PRECIPITATION FROM MOST OF CALIFORNIA EASTWARD ACROSS MOST  
OF THE INTERMOUNTAIN REGION AND ROCKIES, THE CENTRAL AND PORTIONS OF THE  
SOUTHERN PLAINS, AND FROM THE MISSISSIPPI VALLEY TO THE APPALACHIANS, FRI-TUE,  
JAN 19-23.  
 
MODERATE RISK OF HEAVY PRECIPITATION FOR EASTERN NEVADA, UTAH, WESTERN  
COLORADO, MUCH OF SOUTHERN WYOMING, NORTHERN ARIZONA, AND SMALL PORTIONS OF  
NEIGHBORING IDAHO AND NEW MEXICO, FRI-SUN, JAN 19-21.  
 
MODERATE RISK OF HEAVY PRECIPITATION FROM THE SOUTH-CENTRAL MISSISSIPPI VALLEY  
NORTHEAST TO THE CENTRAL GREAT LAKES REGION, FRI-SUN, JAN 19-21.  
 
HIGH RISK OF HEAVY PRECIPITATION IN UTAH, FRI-SUN, JAN 19-21.  
 
SEVERE DROUGHT FOR PARTS OF THE GREAT PLAINS, THE SOUTHWEST, THE CENTRAL AND  
SOUTHERN MISSISSIPPI VALLEY, THE SOUTHEAST, AND HAWAII.  
 
DETAILED SUMMARY  
 
FOR SUNDAY JANUARY 14 - THURSDAY JANUARY 18: SURFACE HIGH PRESSURE IS  
ANTICIPATED ACROSS THE EASTERN HALF OF THE CONUS AT THE BEGINNING OF THE  
HAZARDS PERIOD. THEN THE LEADING EDGE OF A CANADIAN ARCTIC AIR MASS IS FORECAST  
TO MOVE SOUTHWARD AND EASTWARD ACROSS THE CENTRAL AND EASTERN LOWER 48 STATES.  
THIS LEADS TO AN EXTENDED PERIOD OF MUCH BELOW NORMAL TEMPERATURES FOR MOST  
AREAS EAST OF THE CONTINENTAL DIVIDE FROM JAN 14-18. TEMPERATURES OF 12-24  
DEGREES BELOW NORMAL F ARE EXPECTED.  
 
HEAVY PRECIPITATION (MOUNTAIN SNOW AND VALLEY RAIN) IS FORECAST FOR THE PACIFIC  
NORTHWEST AND NORTHWESTERN CALIFORNIA, JAN 16-17, AS AN OCCLUDED FRONTAL SYSTEM  
APPROACHES THE REGION. LIQUID EQUIVALENT AMOUNTS OF 2-4 INCHES ARE ANTICIPATED.  
 
MULTIPLE LOW PRESSURE SYSTEMS OVER THE ALASKA DOMAIN ARE PREDICTED TO BRING A  
VARIETY OF HAZARDS TO THE SOUTH COAST OF ALASKA, FROM THE ALASKA PENINSULA  
EASTWARD AND SOUTHEASTWARD THROUGH THE SOUTHEAST PANHANDLE, PRIMARILY ON JAN  
14. HEAVY PRECIPITATION (RAINFALL IN EXCESS OF 2 INCHES IN 24 HOURS AT LOW  
ELEVATIONS, SNOWFALL IN EXCESS OF 8 INCHES IN 24 HOURS AT HIGHER ELEVATIONS) IS  
ANTICIPATED FOR THIS REGION. HIGH WIND SPEEDS (IN EXCESS OF 40 KNOTS) AND HIGH  
SIGNIFICANT WAVES (HEIGHTS IN EXCESS OF 25 FEET) ARE ALSO FORECAST FOR THE SAME  
GENERAL AREA. A CHINOOK WIND EVENT IS EXPECTED FOR PARTS OF SOUTHERN ALASKA,  
JAN 14-16, LEADING TO TEMPERATURES OF AT LEAST 20-25 DEGREES F ABOVE NORMAL.  
 
FOR FRIDAY JANUARY 19 - THURSDAY JANUARY 25: DURING WEEK-2, BOTH TEMPERATURE  
AND PRECIPITATION HAZARDS ARE FORECAST FOR PARTS OF THE CONUS. THE PREDICTED  
CIRCULATION PATTERN FAVORS BELOW NORMAL 500-HPA HEIGHTS OVER THE WESTERN CONUS  
AND THE ALASKA PANHANDLE, WITH MOST REMAINING AREAS HAVING ABOVE NORMAL 500-HPA  
HEIGHTS. AT THE START OF WEEK-2, RESIDUAL COLD OVER THE SOUTHEAST AND  
MID-ATLANTIC WARRANTS A SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES, BUT THIS  
IS EXPECTED TO LAST ONLY A DAY, FOLLOWED BY A RAPID WARMUP.  
 
WITH TROUGH ENERGY MOVING ONSHORE OVER THE WESTERN CONUS, AND AIR OF PACIFIC  
ORIGIN DOMINATING MOST OF THE COUNTRY, THERE IS A SLIGHT RISK OF HEAVY  
PRECIPITATION FOR MUCH OF THE CONUS (JAN 19-23). THERE IS A MODERATE RISK OF  
HEAVY PRECIPITATION FOR EASTERN NEVADA, UTAH, WESTERN COLORADO, MUCH OF  
SOUTHERN WYOMING, NORTHERN ARIZONA, AND SMALL PORTIONS OF NEIGHBORING IDAHO AND  
NEW MEXICO, FRI-SUN, JAN 19-21. A MODERATE RISK AREA ALSO EXISTS FROM THE  
SOUTH-CENTRAL MISSISSIPPI VALLEY NORTHEASTWARD TO THE CENTRAL GREAT LAKES  
REGION, FOR THE SAME TIME PERIOD. THERE IS A HIGH RISK OF HEAVY PRECIPITATION  
FOR UTAH, JAN 19-21.  
 
THE U.S. DROUGHT MONITOR, VALID ON JANUARY 9, 2018 INDICATES AN INCREASE IN THE  
COVERAGE OF SEVERE TO EXCEPTIONAL DROUGHT (D2-D4) FROM 7.46% LAST WEEK TO 8.70%  
THIS WEEK. SOME OF THE MORE SIGNIFICANT ADJUSTMENTS MADE THIS WEEK INCLUDE  
IMPROVEMENT (FROM D3 TO D2) IN EASTERN MONTANA, SOME DETERIORATION IN OKLAHOMA  
(D2 TO D3), AND THE INTRODUCTION OF ABNORMAL DRYNESS (D0) IN PARTS OF OREGON.  
 
FORECASTER: ANTHONY ARTUSA  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page