292  
FXUS21 KWNC 231904  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT MARCH 23 2017  
 
SYNOPSIS: SEVERAL WEAK LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK NORTHEASTWARD  
FROM THE SOUTHERN HIGH PLAINS TO THE NORTHEAST DURING MOST OF THE OUTLOOK  
PERIOD. MOST OF THE HAZARDOUS WEATHER CONDITIONS ARE PREDICTED TO BE OVER THE  
SOUTHERN GREAT PLAINS, THE LOWER MISSISSIPPI VALLEY, AND THE NORTHEAST. THE  
ANTICIPATED PASSAGE OF SEVERAL FRONTAL SYSTEMS ACROSS THE WEST DURING THIS  
OUTLOOK PERIOD MAY ALSO BRING ADDITIONAL HAZARDS, PRIMARILY TO THE NORTHWESTERN  
CONTIGUOUS U.S. THE NORTHERN PORTIONS OF ALASKA ARE PREDICTED TO BE DOMINATED  
BY SURFACE HIGH PRESSURE, WHILE SOUTHERN AREAS ARE FORECAST TO BE AFFECTED BY  
THE OCCASIONAL PASSAGE OF WEAK LOW PRESSURE AREAS.  
 
HAZARDS  
 
SEVERE WEATHER FOR PARTS OF THE SOUTHERN PLAINS, SUN, MAR 26.  
 
SEVERE WEATHER FOR PARTS OF THE LOWER MISSISSIPPI AND LOWER TENNESSEE VALLEYS,  
MON, MAR 27.  
 
ENHANCED RISK OF CRITICAL WILDFIRE CONDITIONS FOR PARTS OF THE FAR SOUTHERN  
HIGH PLAINS REGION, SUN, MAR 26.  
 
FREEZING RAIN/SLEET FOR NORTHERN PORTIONS OF LOWER MICHIGAN, NORTHERN NEW YORK,  
AND MUCH OF NEW ENGLAND, SUN-MON, MAR 26-27.  
 
PERIODS OF LOCALLY HEAVY RAIN FOR PARTS OF THE SOUTHERN PLAINS, WED-THU, MAR  
29-30.  
 
PERIODS OF LOCALLY HEAVY RAIN FOR THE I-95 CORRIDOR FROM NEAR THE NATION'S  
CAPITAL NORTHEASTWARD TO SOUTHERN NEW HAMPSHIRE, SUN-MON, MAR 26-27.  
 
HEAVY PRECIPITATION (RAIN AND MOUNTAIN SNOW) FOR THE PACIFIC NORTHWEST AND FAR  
NORTHWESTERN CALIFORNIA, SUN-MON, MAR 26-27.  
 
FLOODING IS POSSIBLE, LIKELY OR IMMINENT/OCCURRING OVER PARTS OF THE PACIFIC  
NORTHWEST, NORTHERN AND CENTRAL INTERMOUNTAIN REGION, THE NORTHERN ROCKIES, AND  
EXTREME NORTHEASTERN MONTANA.  
 
HEAVY RAIN FOR EASTERN PORTIONS OF BOTH OKLAHOMA AND TEXAS, AND THE LOWER  
MISSISSIPPI VALLEY, SAT-SUN, APR 1-2.  
 
SLIGHT CHANCE OF MUCH ABOVE-NORMAL TEMPERATURES FROM THE LOWER MISSISSIPPI  
VALLEY EASTWARD TO THE SOUTHERN ATLANTIC COAST, FRI-SAT, MAR 31-APR 1.  
 
SEVERE DROUGHT ACROSS PARTS OF ARIZONA, CALIFORNIA, THE CENTRAL AND SOUTHERN  
GREAT PLAINS, ARKANSAS, MISSOURI, AND THE EASTERN U.S.  
 
DETAILED SUMMARY  
 
FOR SUNDAY MARCH 26 - THURSDAY MARCH 30: DURING THIS PERIOD, SEVERAL LOW  
PRESSURE SYSTEMS ARE FORECAST TO DEVELOP OVER THE SOUTHERN HIGH PLAINS REGION,  
THEN TRACK NORTHEASTWARD ACROSS THE MIDDLE MISSISSIPPI VALLEY AND MIDWEST, AND  
INTO THE NORTHEAST. EACH OF THESE LOWS IS EXPECTED TO BE ACCOMPANIED BY SEVERAL  
HAZARDS. AS THE FIRST SYSTEM MOVES ACROSS THE OHIO VALLEY AND NORTHEAST, AN  
AREA OF LOCALLY HEAVY RAIN (1-2 INCHES) IS FORECAST ACROSS THE I-95 CORRIDOR  
FROM NEAR THE NATION'S CAPITAL NORTHEASTWARD TO SOUTHERN NEW HAMPSHIRE, ON  
MARCH 26-27. AT THE SAME TIME, A WINTRY MIX OF RAIN, FREEZING RAIN, SLEET, AND  
SNOW IS EXPECTED TO DEVELOP FROM NORTHERN LOWER MICHIGAN EASTWARD ACROSS  
NORTHERN NEW YORK AND MUCH OF NEW ENGLAND.  
 
THE SECOND IN A CONTINUING SERIES OF LOW PRESSURE SYSTEMS IS ANTICIPATED TO  
MOVE ACROSS THE SOUTH-CENTRAL CONUS ON MARCH 26-27. THERE IS AN ELEVATED RISK  
OF CRITICAL WILDFIRE CONDITIONS ON MARCH 26TH ACROSS FAR SOUTHERN PORTIONS OF  
THE SOUTHERN HIGH PLAINS REGION, FROM ABOUT EL PASO TO SAN ANGELO, TEXAS.  
STRONG WINDS ALOFT AHEAD OF THE ASSOCIATED 500-HPA SHORTWAVE, DEEP  
BOUNDARY-LAYER MIXING, A TIGHT SURFACE PRESSURE GRADIENT, ABOVE-AVERAGE  
TEMPERATURES, AND RELATIVE HUMIDITY VALUES BELOW 15 PERCENT ARE ALL EXPECTED TO  
CONTRIBUTE TO THIS ELEVATED RISK OF WILDFIRES. ON THE SAME DAY, OVER THE  
SOUTHERN LOWER PLAINS, THERE IS A SIGNIFICANT RISK OF SEVERE WEATHER BREAKING  
OUT IN ADVANCE OF A DRYLINE, AS IT MIXES EASTWARD ACROSS THE SOUTHERN PLAINS  
DURING THE DAYTIME. THE FOLLOWING DAY, MARCH 27TH, ANOTHER ROUND OF SEVERE  
WEATHER IS EXPECTED TO DEVELOP FARTHER EAST, OVER THE LOWER MISSISSIPPI AND  
LOWER TENNESSEE VALLEYS. YET ANOTHER LOW PRESSURE SYSTEM IS FORECAST TO MOVE  
THROUGH THE SOUTHERN STREAM ACROSS THE SOUTHERN PLAINS REGION AND LOWER  
MISSISSIPPI VALLEY, BRINGING PERIODS OF LOCALLY HEAVY RAINFALL TO PORTIONS OF  
OKLAHOMA AND TEXAS ON MARCH 29-30. THOUGH STRONG TO SEVERE THUNDERSTORMS ARE  
AGAIN POSSIBLE, THERE IS TOO MUCH UNCERTAINTY BETWEEN THE ECMWF AND GFS  
SOLUTIONS AT THIS TIME TO JUSTIFY THE DEPICTION OF A SEVERE WEATHER AREA ON THE  
MAP. THE GFS MODEL SUGGESTS THE POSSIBILITY OF SEVERE WEATHER RECURRING IN THE  
SAME GENERAL AREA (SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY, GENERALLY  
CENTERED ON THE ARKLATEX REGION), WHILE THE ECMWF MODEL SUGGESTS THE SEVERE  
WEATHER RISK AREA MAY EXTEND NORTHWARD TO INCLUDE PORTIONS OF THE CENTRAL  
PLAINS AND MIDDLE MISSISSIPPI VALLEY.  
 
PACIFIC STORM SYSTEMS ARE FORECAST TO MOVE ACROSS THE WEST COAST STATES DURING  
THIS PERIOD. A HEAVY PRECIPITATION (RAIN AND MOUNTAIN SNOW) HAZARD IS POSTED  
FOR WESTERN WASHINGTON, WESTERN OREGON, AND FAR NORTHWESTERN CALIFORNIA, FOR  
LIQUID EQUIVALENT PRECIPITATION AMOUNTS OF ABOUT 1.5-2.5 INCHES. USING 2 INCHES  
AS THE APPROXIMATE THRESHOLD FOR SEPARATING HAZARDOUS AMOUNTS OF PRECIPITATION  
FROM NON-HAZARDOUS AMOUNTS, IT IS CLEAR THIS IS CONSIDERED A MARGINAL HAZARD AT  
BEST.  
 
FLOODING IS POSSIBLE, LIKELY, OR OCCURRING/IMMINENT ACROSS PARTS OF THE PACIFIC  
NORTHWEST, THE NORTHERN AND CENTRAL INTERMOUNTAIN REGION, THE NORTHERN ROCKIES,  
AND EXTREME NORTHEASTERN MONTANA. THIS IS DUE TO UNSEASONABLY WARM TEMPERATURES  
COUPLED WITH RAINFALL DURING MID-MARCH.  
 
IN ALASKA, NO HAZARDS ARE POSTED AT THIS TIME DUE TO SURFACE HIGH PRESSURE  
PREDICTED ACROSS THE NORTHERN PART OF THE STATE, AND WEAK LOW PRESSURE SYSTEMS  
MOVING ACROSS THE SOUTHERN PART OF THE STATE. ONE VERY LOCALIZED ISSUE BEING  
CONSIDERED IS THE POTENTIAL FOR HEAVY PRECIPITATION (2 INCHES OR MORE, LIQUID  
EQUIVALENT, DURING A 24-HOUR PERIOD) FOR WESTERN SECTIONS OF PRINCE WILLIAM  
SOUND (INCLUDING COLLEGE FJORD) AND THE EASTERN KENAI PENINSULA ON MARCH 30TH.  
THIS IS DUE TO AN APPROACHING LOW PRESSURE SYSTEM AND SUSTAINED SOUTHEASTERLY  
FLOW FORCING MOISTURE TO RISE UP THE SLOPES OF THE CHUGACH MOUNTAIN RANGE, AND  
CONDENSE.  
 
FOR FRIDAY MARCH 31 - THURSDAY APRIL 06: AN AREA OF HEAVY RAIN IS FORECAST OVER  
EASTERN PORTIONS OF BOTH OKLAHOMA AND TEXAS, AND OVER THE LOWER MISSISSIPPI  
VALLEY, FROM APRIL 1-2. THIS IS IN RESPONSE TO A 500-HPA TROUGH EXPECTED TO  
APPROACH THIS AREA FROM THE WEST. THERE IS ALSO THE POTENTIAL FOR STRONG TO  
SEVERE THUNDERSTORMS TO DEVELOP ONCE AGAIN, THOUGH AS DISCUSSED IN THE PREVIOUS  
SECTION, THE MAIN UNCERTAINTY IS THE SPATIAL EXTENT OF A POSSIBLE SEVERE  
WEATHER OUTBREAK.  
 
ON MARCH 31-APRIL 1, THERE IS A SLIGHT CHANCE (20-PERCENT) OF MUCH ABOVE-NORMAL  
TEMPERATURES FROM THE LOWER MISSISSIPPI VALLEY EASTWARD TO THE SOUTHERN  
ATLANTIC COAST. WITHIN THIS AREA, TEMPERATURES ARE EXPECTED TO REACH THE 85TH  
PERCENTILE (OR HIGHER) OF THE HISTORICAL DISTRIBUTION. FOR MOST AREAS, HIGH  
TEMPERATURES ARE FORECAST TO REACH THE MID-UPPER 80'S, WHILE A FEW LOCALES MAY  
PUSH 90 DEG F.  
 
ACCORDING TO THE U.S. DROUGHT MONITOR RELEASED ON MARCH 23RD (USING DATA  
THROUGH 8AM EASTERN TIME, MARCH 21ST), CHANGES COMPARED TO THE PREVIOUS WEEK  
INCLUDED ONE-CLASS DEGRADATION ACROSS PARTS OF THE SOUTHERN TIER OF STATES FROM  
NEW MEXICO TO SOUTH CAROLINA, PARTS OF OKLAHOMA AND KANSAS, AND HAWAII.  
ONE-CLASS IMPROVEMENTS IN DROUGHT CATEGORY WERE PRIMARILY FOCUSED ON THE  
NORTHEAST AND MID-ATLANTIC, TENNESSEE, NORTHERN ALABAMA, AND EASTERN PORTIONS  
OF PUERTO RICO. NO CHANGES TO THE DROUGHT DEPICTION WERE MADE IN ALASKA.  
COVERAGE OF SEVERE, OR GREATER INTENSITY, DROUGHT THROUGHOUT THE CONUS  
DECREASED SLIGHTLY FROM 3.95 LAST WEEK TO 3.74 PERCENT THIS WEEK.  
 
FORECASTER: ANTHONY ARTUSA  
 

 
 
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