560
FXUS21 KWNC 031737
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT APRIL 03 2024
SYNOPSIS: MID-LEVEL LOW PRESSURE WITH ASSOCIATED SURFACE LOW PRESSURE IS
FAVORED TO INCREASE THE POTENTIAL FOR HEAVY PRECIPITATION AND HIGH WINDS FOR
PORTIONS OF THE EASTERN CONTIGUOUS U.S. (CONUS) AT THE ONSET OF THE WEEK-2
FORECAST PERIOD. IN THE WAKE OF THIS SYSTEM DYNAMICAL MODELS DEPICT A MORE
TRANQUIL PATTERN, AND CONSEQUENTLY DECREASING CHANCES FOR WIDESPREAD HAZARDOUS
WEATHER.
HAZARDS
SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE OHIO, TENNESSEE, AND
LOWER MISSISSIPPI VALLEYS, SOUTHERN APPALACHIANS, MID-ATLANTIC, AND SOUTHEAST,
THU-FRI, APR 11-12.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE GREAT LAKES, OHIO
VALLEY, CENTRAL APPALACHIANS, MID-ATLANTIC, AND NORTHEAST, FRI-SAT, APR 12-13.
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF THE OHIO, TENNESSEE, AND LOWER AND
MIDDLE MISSISSIPPI VALLEYS, SOUTHERN APPALACHIANS, MID-ATLANTIC, AND SOUTHEAST,
THU-FRI, APR 11-12.
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF THE CENTRAL APPALACHIANS,
MID-ATLANTIC, OHIO VALLEY, GREAT LAKES, AND NORTHEAST, THU-SUN, APR 11-14.
DETAILED SUMMARY
FOR SATURDAY APRIL 06 - WEDNESDAY APRIL 10:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY APRIL 11 - WEDNESDAY APRIL 17: MULTIPLE MODEL ENSEMBLES ARE IN
GOOD AGREEMENT DEPICTING A FAIRLY AMPLIFIED MID-LEVEL TROUGH AND AN ASSOCIATED
LOW PRESSURE SYSTEM OVER THE GREAT PLAINS AT THE OUTSET OF WEEK-2. THIS PATTERN
FAVORS MOIST INFLOW OFF THE GULF OF MEXICO AND THE INCREASED POTENTIAL FOR
HEAVY PRECIPITATION AHEAD OF THIS SYSTEM. THE GEFS AND ECMWF BOTH INDICATE
24-HR PRECIPITATION TOTALS POSSIBLY EXCEEDING 1 INCH OVER A BROAD AREA OF THE
EASTERN CONUS. THE ECMWF AND GEFS PRECIPITATION PROBABILISTIC EXTREMES TOOLS
(PETS) SHOW AT LEAST A 20% PROBABILITY OF 3-DAY PRECIPITATION TOTALS EXCEEDING
THE 85TH PERCENTILE CLIMATOLOGICALLY OVER MUCH OF THE EASTERN CONUS, WITH AT
LEAST 1 INCH POSSIBLE FOR MUCH OF THE EASTERN SEABOARD. THIS SYSTEM IS FAVORED
TO MOVE QUICKLY, THEREFORE TWO AREAS HIGHLIGHTING THE RISK OF HEAVY
PRECIPITATION ARE POSTED: THE FIRST COVERS PORTIONS OF THE OHIO, TENNESSEE, AND
LOWER MISSISSIPPI VALLEYS, SOUTHERN APPALACHIANS, MID-ATLANTIC, AND SOUTHEAST
FOR APR 11-12, AND THE SECOND COVERS PORTIONS OF THE GREAT LAKES, OHIO VALLEY,
CENTRAL APPALACHIANS, MID-ATLANTIC, AND NORTHEAST FOR APR 12-13.
SURFACE PRESSURE GRADIENTS ARE LIKELY TO BE QUITE STRONG AHEAD OF THIS SYSTEM,
BRINGING THE INCREASED LIKELIHOOD FOR HIGH WINDS TO MUCH OF THE CENTRAL AND
EASTERN CONUS. THIS IS WELL-INDICATED BY THE ECMWF PET, WHICH SHOWS AT LEAST A
20% PROBABILITY OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND AT LEAST 20
MPH FOR THE EARLY AND MIDDLE PORTIONS OF THE FORECAST PERIOD. THE GEFS PET FOR
HIGH WINDS IS LESS BULLISH BUT STILL INDICATES ENHANCED CHANCES FOR HIGH WINDS
FOR THE SOUTHEAST EARLY IN THE FORECAST PERIOD. MODEL SOLUTIONS INDICATE FAST
NORTHEASTWARD MOVEMENT OF THE STORM SYSTEM IN QUESTION, SO TWO HAZARDS ARE
POSTED: THE FIRST COVERS PORTIONS OF THE OHIO, TENNESSEE, AND LOWER AND MIDDIE
MISSISSIPPI VALLEYS, SOUTHERN APPALACHIANS, MID-ATLANTIC, AND SOUTHEASTERN U.S.
FOR APR 11-12, AND THE SECOND COVERING PORTIONS OF THE CENTRAL APPALACHIANS,
MID-ATLANTIC, OHIO VALLEY, GREAT LAKES, AND NORTHEAST U.S. FOR APR 11-14.
A LATE-SEASON NOR’EASTER IS CURRENTLY BRINGING MIXED PRECIPITATION AND SNOW,
POTENTIALLY HEAVY AT TIMES, TO PORTIONS OF NEW ENGLAND. HOWEVER, BY THE
BEGINNING OF WEEK-2 MUCH-ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE
NORTHEAST CONUS. THIS COMBINATION HAS THE POTENTIAL TO CREATE FLOODING
CONDITIONS ESPECIALLY IN AREAS WHERE SNOW RECEIVED IS THE HIGHEST. NO
ASSOCIATED HAZARD IS POSTED AT THIS TIME BUT THE SITUATION WILL BE CAREFULLY
MONITORED IN THE COMING DAYS.
IN ALASKA, DAYTIME MAXIMUM TEMPERATURES FOR THE ALASKAN INTERIOR ARE FAVORED TO
BEGIN EXCEEDING THE FREEZING MARK, AND INCREASING INCOMING SOLAR RADIATION
FLUXES INEVITABLY LEAD TO THE MELT-OFF OF THE WINTER’S SNOWPACK. RIVERS OF THE
INTERIOR ARE CURRENTLY FROZEN, BUT WITH THE IMPENDING BREAK-UP SEASON AND
INCREASING SNOWMELT, FLOODING WILL BEGIN TO BECOME A CONCERN IN THE NEAR
FUTURE. NO HAZARDS ARE POSTED AT THIS TIME BUT THIS SITUATION WILL ALSO BE
CLOSELY MONITORED IN THE COMING DAYS AND WEEKS.
FORECASTER: DANNY BARANDIARAN
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