862
FXUS21 KWNC 281832
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MARCH 28 2024
SYNOPSIS: AN AREA OF DEPARTING SURFACE LOW PRESSURE ACROSS THE NORTHEASTERN
CONTIGUOUS U.S. (CONUS) MAY BRING PERIODS OF HIGH WINDS TO PORTIONS OF THE
NORTHEAST AT THE START OF THE WEEK-2 PERIOD. MEANWHILE, A DIGGING TROUGH AND
ASSOCIATED LEE-SIDE CYCLOGENESIS WILL BRING MULTIPLE CHANCES FOR HEAVY SNOW TO
PARTS OF THE NORTHERN AND CENTRAL PLAINS AND ROCKY MOUNTAINS. MORE BROADLY,
PERIODS OF HIGH WINDS MAY OCCUR IN CONJUNCTION WITH THE ROBUST TROUGH AND A
SERIES OF SURFACE LOWS ACROSS THE WEST. IN THE SOUTHEAST, RETURN FLOW OFF THE
GULF OF MEXICO AND FRONTAL SYSTEMS EXTENDING FROM MULTIPLE AREAS OF
LOW-PRESSURE ACROSS THE PLAINS BRINGS CHANCES FOR HEAVY PRECIPITATION TO
PORTIONS OF THE SOUTHEASTERN CONUS BY THE MIDDLE AND END OF THE PERIOD.
HAZARDS
SLIGHT RISK OF HIGH WINDS FOR PARTS OF THE NORTHEAST, FRI, APR 5.
SLIGHT RISK OF HEAVY SNOW FOR PORTIONS OF THE NORTHERN AND CENTRAL PLAINS AND
THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS, FRI-TUE, APR 5-9.
SLIGHT RISK OF EPISODIC HIGH WINDS FOR THE GREAT PLAINS AND INTERIOR WEST,
FRI-TUE, APR 5-9.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE MIDDLE AND
LOWER-MISSISSIPPI, TENNESSEE, AND OHIO RIVER VALLEYS, SOUTHERN PLAINS, AND
SOUTHEAST, SUN-THU, APR 7-11.
DETAILED SUMMARY
FOR SUNDAY MARCH 31 - THURSDAY APRIL 04:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY APRIL 05 - THURSDAY APRIL 11: MID-LEVEL TROUGHING AND ASSOCIATED
SURFACE LOW-PRESSURE WILL BE PROGRESSING EAST OFF OF THE NORTHEAST AT THE END
OF WEEK-1. MODELS ARE IN FAIR AGREEMENT WITH THIS SYSTEM BRINGING CHANCES FOR
HIGH WINDS TO PORTIONS OF THE NORTHEAST AT THE VERY BEGINNING OF WEEK-2. THE
GEFS AND ECENS HAVE MANY MEMBERS FORECASTING THE MEAN SEA LEVEL PRESSURE (MSLP)
TO FALL TOWARDS 990MB. THEREFORE, A SLIGHT RISK OF HIGH WINDS IS POSTED FOR APR
5. HOWEVER, MUCH OF THIS SYSTEM IS FORECAST TO BE EAST OF THE US BY THE START
OF WEEK-2 AND THE ASSOCIATED SNOW HAZARD FORECAST YESTERDAY HAS BEEN
DISCONTINUED.
ACROSS THE INTERIOR WEST, AN AREA OF NEGATIVE MID-LEVEL HEIGHT ANOMALIES IS
FORECAST TO DEVELOP AND PERSIST FOR MUCH OF THE WEEK-2 PERIOD. THIS IS LIKELY
TO BRING GENERALLY UNSETTLED WEATHER TO MUCH OF THE WESTERN AND CENTRAL
CONTIGUOUS U.S. (CONUS) DURING THE PERIOD. AS THE TROUGH DIGS INTO THE WEST
EARLY IN THE PERIOD, THE ECENS PROBABILISTIC EXTREMES TOOL (PET) SHOWS AT LEAST
A 20% CHANCE OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND 20 MPH (25 MPH,
LOCALLY) ACROSS THE HIGHLIGHTED RISK AREA. THE GEFS PET INDICATES THESE
THRESHOLDS FOR THE SOUTHWEST INTO THE CENTRAL PLAINS. LEE-SIDE CYCLOGENESIS IS
ALSO LIKELY TO SUPPORT INCREASED CHANCES FOR HIGH WINDS FURTHER INTO THE
CENTRAL AND NORTHERN PLAINS DURING MUCH OF THE PERIOD. FINALLY, THE NATIONAL
INTERAGENCY FIRE CENTER (NIFC) INDICATES LOW TO MODERATE FIRE POTENTIAL ACROSS
PARTS OF THE EASTERN FOUR CORNERS REGION AND CENTRAL AND SOUTHERN PLAINS BY THE
END OF WEEK-1. LITTLE TO NO PRECIPITATION ANTICIPATED DURING WEEK-1 COMBINED
WITH INCREASED HIGH WIND RISK DURING WEEK-2 MAY SUPPORT ENHANCED WILDFIRE RISK
IN THESE REGIONS. THEREFORE, A SLIGHT RISK OF EPISODIC HIGH WINDS IS POSTED FOR
THE GREAT PLAINS, INTERIOR WEST, AND SOUTHWEST, APR 5-9. BY THE END OF THE
PERIOD THE MID-LEVEL TROUGH IS LIKELY TO BE MOVING EAST AND WEAKLY ABOVE-NORMAL
500-HPA HEIGHTS ARE FORECAST REDUCING THE CHANCES FOR HIGH WINDS ACROSS THE
REGION.
THE DIGGING MID-LEVEL TROUGH AND CYCLOGENESIS IN THE LEE OF THE ROCKIES
INCREASES CHANCES FOR HEAVY SNOW ACROSS PORTIONS OF THE PLAINS AND ROCKIES. THE
GEFS SNOW WATER EQUIVALENT (SWE) PET INDICATES CHANCES FOR SWE TO EXCEED THE
85TH CLIMATOLOGICAL PERCENTILE ACROSS PORTIONS OF THE PLAINS. MEANWHILE, THE
ECENS PET INDICATES PRECIPITATION TO EXCEED THE 85TH PERCENTILE ACROSS A BROAD
AREA IN THE NORTH-CENTRAL CONUS. CORRESPONDINGLY, THE RAW ECENS INDICATES
30-40% CHANCES FOR SNOW TO EXCEED FOUR INCHES ACROSS THIS REGION DURING THE
EARLY TO MIDDLE OF THE PERIOD. THEREFORE, A SLIGHT RISK OF HEAVY SNOW IS POSTED
FOR THE CENTRAL ROCKIES AND NORTHERN AND CENTRAL PLAINS FOR APRIL 5-9.
RETURN FLOW OFF THE GULF OF MEXICO MAY DEVELOP BY THE MIDDLE THROUGH THE END OF
WEEK-2. THE ASSOCIATED FRONTAL SYSTEMS FROM THE LEE CYCLOGENESIS DISCUSSED
ABOVE MAY HELP TO INITIATE CHANCES FOR HEAVY PRECIPITATION IN PARTS OF THE
SOUTHEASTERN CONUS. THE ECENS AND GEFS PETS DEVELOP OVER 20% CHANCES FOR 3 DAY
PRECIPITATION AMOUNTS TO EXCEED THE 85TH PERCENTILE AND 1 INCH ACROSS A WIDE
AREA IN THE SOUTHEASTERN CONUS. THERE IS ALSO BROAD SUPPORT FROM THE RAW TOOLS
AS WELL FOR THIS REGION WITH 3 DAY PRECIPITATION AMOUNTS FROM THE RAW ECENS
INDICATING GREATER THAN A 40% CHANCE OF EXCEEDING 1 INCH. THEREFORE, A SLIGHT
RISK OF HEAVY PRECIPITATION IS POSTED FOR THIS REGION FOR APR 7-11.
FOR ALASKA, THE MEAN MID-LEVEL PATTERN IS FORECAST TO BE FAIRLY ZONAL, WITH
POTENTIALLY POSITIVE 500 HPA HEIGHT DEPARTURES ACROSS THE SOUTHERN HALF OF THE
STATE. THERE IS MULTI-MODEL DEPICTION OF A SERIES OF SURFACE LOWS FORMING OVER
THE BERING SEA AND GULF OF ALASKA, ALTHOUGH THESE ARE NOT EXPECTED TO LEAD TO
WIDESPREAD HAZARDOUS CONDITIONS.
FORECASTER: RYAN BOLT
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