154  
FXUS21 KWNC 052023  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EST MARCH 05 2018  
 
SYNOPSIS: SURFACE LOW PRESSURE FORECAST JUST OFF THE NEW ENGLAND COAST MAR 8 IS  
EXPECTED TO MOVE SLOWLY NORTHWARD TO THE MARITIME PROVINCES OF CANADA MAR 10.  
SURFACE HIGH PRESSURE OVER THE CENTRAL U.S. MAR 8 IS PREDICTED TO MOVE TO THE  
EASTERN PART OF THE NATION MAR 10. SURFACE LOW PRESSURE AND ITS ASSOCIATED  
FRONTAL SYSTEM WILL CROSS THE NORTHWESTERN U.S. MAR 8-9, FOLLOWED BY ANOTHER  
DEEPER AREA OF SURFACE LOW PRESSURE MAR 11-12. SURFACE LOW PRESSURE IS FORECAST  
TO DEVELOP OVER THE SOUTHERN PLAINS MAR 9 AND MOVE EAST/NORTHEASTWARD TO OFF  
THE MID-ATLANTIC COAST MAR 12. DEEP SURFACE LOW PRESSURE NEAR THE WEST COAST OF  
MAINLAND ALASKA MAR 8 IS FORECAST TO MOVE SOUTHEASTWARD TO THE GULF OF ALASKA  
MAR 11. DURING WEEK-2, AREAS OF MID-LEVEL LOW PRESSURE ARE ANTICIPATED TO BE  
MOVING OFF THE EAST COAST, APPROACHING THE WESTERN U.S., AND OVER ALASKA, WHILE  
MID-LEVEL HIGH PRESSURE IS EXPECTED OVER THE CENTRAL PORTION OF THE LOWER 48  
STATES.  
 
HAZARDS  
 
HEAVY SNOW FOR PARTS OF THE NORTHEAST, THU, MAR 8.  
 
HIGH WINDS FOR PARTS OF COASTAL SECTIONS OF THE NORTHEAST, THU MAR 8.  
 
PERIODS OF HEAVY SNOW FOR PARTS OF THE CASCADES, THU-MON, MAR 8-12.  
 
PERIODS OF HEAVY SNOW FOR PARTS OF THE BITTERROOTS, THU-MON, MAR 8-12.  
 
PERIODS OF HEAVY SNOW FOR PARTS OF THE NORTHERN ROCKIES, THU-MON, MAR 8-12.  
 
HEAVY SNOW FOR PARTS OF THE SIERRAS, SAT-SUN, MAR 10-11.  
 
MUCH BELOW NORMAL TEMPERATURES FOR PARTS OF THE NORTHERN PLAINS, THU, MAR 8.  
 
HEAVY PRECIPITATION FOR PARTS OF THE LOWER MISSISSIPPI, TENNESSEE, AND OHIO  
VALLEYS, SOUTHERN AND CENTRAL APPALACHIANS, MID-ATLANTIC, AND NORTHEAST,  
SAT-MON, MAR 10-12.  
 
HIGH WINDS FOR COASTAL SECTIONS OF WASHINGTON, OREGON,AND NORTHERN CALIFORNIA,  
SUN-MON, MAR 11-12.  
 
HIGH SIGNIFICANT WAVE HEIGHTS FOR COASTAL SECTIONS OF WASHINGTON, OREGON,AND  
NORTHERN CALIFORNIA, SUN-MON, MAR 11-12.  
 
HIGH WINDS FOR PARTS OF THE ALEUTIANS, ALASKA PENINSULA, SOUTHERN AND WESTERN  
COASTAL MAINLAND ALASKA, AND THE ALASKA PANHANDLE, THU-SAT, MAR 8-10.  
 
HIGH SIGNIFICANT WAVE HEIGHTS FOR PARTS OF THE ALEUTIANS, ALASKA PENINSULA, AND  
SOUTHERN COASTAL MAINLAND ALASKA, THU-SAT, MAR 8-10.  
 
FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE SOUTHERN PLAINS, LOWER  
AND MIDDLE MISSISSIPPI VALLEYS, THE OHIO AND TENNESSEE VALLEYS, AND THE GREAT  
LAKES.  
 
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR PORTIONS OF THE SOUTHEASTERN  
CONUS, TUE-THU, MAR 13-15.  
 
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR PORTIONS OF THE WESTERN  
CONUS, THU-SUN, MAR 15-18.  
 
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR MUCH OF ALASKA, TUE-MON, MAR  
13-19.  
 
MODERATE RISK OF MUCH BELOW NORMAL TEMPERATURES FOR PARTS OF THE ALEUTIANS, THE  
ALASKA PENINSULA, AND SOUTHERN MAINLAND ALASKA, TUE-FRI, MAR 13-16.  
 
HIGH RISK OF MUCH BELOW NORMAL TEMPERATURES FOR PARTS OF THE ALASKA PENINSULA  
AND SOUTHERN MAINLAND ALASKA, TUE-WED, MAR 13-14.  
 
SEVERE DROUGHT ACROSS THE CENTRAL PLAINS, THE CENTRAL ROCKIES, THE CENTRAL  
GREAT BASIN, THE NORTHERN PLAINS, THE SOUTHERN ROCKIES, CALIFORNIA, THE  
SOUTHERN PLAINS, AND THE SOUTHWEST.  
 
DETAILED SUMMARY  
 
FOR THURSDAY MARCH 08 - MONDAY MARCH 12: DEEP LOW PRESSURE IS FORECAST JUST OFF  
THE COAST OF NEW ENGLAND MAR 8. THIS LEADS TO HEAVY SNOW (AMOUNTS IN EXCESS OF  
6 INCHES IN 24 HOURS) FOR PARTS OF THE NORTHEAST, AND HIGH WINDS (SPEEDS IN  
EXCESS OF 30 KNOTS) FOR COASTAL SECTIONS OF THE NORTHEAST. THE COMBINATION OF  
HEAVY SNOW AND HIGH WINDS COULD LEAD TO CONSIDERABLE BLOWING AND DRIFTING OF  
THE SNOW.  
 
COLD HIGH PRESSURE IS FORECAST OVER THE CENTRAL CONUS MAR 8. MUCH BELOW NORMAL  
TEMPERATURES (NEGATIVE ANOMALIES OF 15-20 DEGREES F) ARE INDICATED FOR FOR  
PARTS OF THE NORTHERN PLAINS ON THIS DAY.  
 
A PAIR OF CYCLONES ARE FORECAST TO CROSS THE NORTHWESTERN CONUS. PERIODS OF  
HEAVY SNOW (AMOUNTS IN EXCESS OF 6 INCHES IN 24 HOURS) ARE EXPECTED FOR PARTS  
OF THE CASCADES, BITTERROOTS, AND NORTHERN ROCKIES MAR 8-12, AND FOR PARTS OF  
THE SIERRAS MAR 10-11. THE SECOND, DEEPER CYCLONE LEADS TO STRONG WINDS (WIND  
SPEEDS IN EXCESS OF 30 KNOTS) AND HIGH SIGNIFICANT WAVE HEIGHTS (HEIGHTS IN  
EXCESS OF 20 FEET) FOR COASTAL SECTIONS OF WASHINGTON, OREGON,AND NORTHERN  
CALIFORNIA MAR 11-12.  
 
LOW PRESSURE IS PREDICTED TO DEVELOP OVER THE SOUTHERN PLAINS MAR 9 AND MOVE  
EAST/NORTHEASTWARD TO OFF THE MID-ATLANTIC COAST MAR 12. HEAVY PRECIPITATION  
(RAINFALL AMOUNTS IN EXCESS OF 1 INCH IN 24 HOURS AT LOWER ELEVATIONS AND  
SOUTHERN PORTIONS OF THE AREA OF PRECIPITATION, SNOWFALL AMOUNTS IN EXCESS OF 4  
INCHES IN 24 HOURS AT HIGHER ELEVATIONS AND ON THE NORTHWESTERN PERIPHERY OF  
THE PRECIPITATION SHIELD) IS ANTICIPATED FOR PARTS OF THE LOWER MISSISSIPPI,  
TENNESSEE, AND OHIO VALLEYS, SOUTHERN AND CENTRAL APPALACHIANS, MID-ATLANTIC,  
AND NORTHEAST MAR 10-12.  
 
ANTECEDENT PRECIPITATION AND THE PROSPECT OF ADDITIONAL PRECIPITATION LEADS TO  
OCCURRING OR IMMINENT FLOODING ACROSS PORTIONS OF THE SOUTHERN PLAINS, LOWER  
AND MIDDLE MISSISSIPPI VALLEYS, THE OHIO AND TENNESSEE VALLEYS, AND THE GREAT  
LAKES.  
 
DEEP LOW PRESSURE MOVING FROM THE WEST COAST OF MAINLAND ALASKA TO THE GULF OF  
ALASKA LEADS TO HIGH WINDS (SPEED IN EXCESS OF 40 KNOTS) AND HIGH SIGNIFICANT  
WAVE HEIGHTS (HEIGHTS IN EXCESS OF 24 FEET) FOR PARTS OF THE ALEUTIANS, ALASKA  
PENINSULA, AND SOUTHERN COASTAL MAINLAND ALASKA MAR 8-10.  
 
FOR TUESDAY MARCH 13 - MONDAY MARCH 19: DURING WEEK-2, MID-LEVEL TROUGHS ARE  
ANTICIPATED TO BE MOVING OFF THE EAST COAST, APPROACHING THE WEST COAST, AND  
OVER ALASKA, WHILE A MID-LEVEL RIDGE IS FORECAST OVER THE CENTRAL CONUS. THIS  
CIRCULATION PATTERN LEADS TO A SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES  
FOR PORTIONS OF THE SOUTHEASTERN CONUS MAR 13-15, A SLIGHT RISK OF MUCH BELOW  
NORMAL TEMPERATURES FOR PORTIONS OF THE WESTERN CONUS MAR 15-18, A SLIGHT RISK  
OF MUCH BELOW NORMAL TEMPERATURES FOR MUCH OF ALASKA MAR 13-19, A MODERATE RISK  
OF MUCH BELOW NORMAL TEMPERATURES FOR PARTS OF THE ALEUTIANS, THE ALASKA  
PENINSULA, AND SOUTHERN MAINLAND ALASKA MAR 13-16, AND A HIGH RISK OF MUCH  
BELOW NORMAL TEMPERATURES FOR PARTS OF THE ALASKA PENINSULA AND SOUTHERN  
MAINLAND ALASKA MAR 13-14.  
 
THE U.S. DROUGHT MONITOR, VALID ON FEB 27, 2018 INDICATES A DECREASE IN THE  
COVERAGE OF SEVERE TO EXCEPTIONAL DROUGHT (D2-D4) FROM 17.76% LAST WEEK TO  
14.31% THIS WEEK. A FEW OF THE MORE SUBSTANTIAL REVISIONS MADE TO THE MAP THIS  
WEEK INCLUDE A DECREASE IN THE D1 COVERAGE OVER PENNSYLVANIA AND A DECREASE IN  
THE D2 COVERAGE OVER OKLAHOMA AND ARKANSAS.  
 
FORECASTER: RANDY SCHECHTER  
 

 
 
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