620
FXUS21 KWNC 271758
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT APRIL 27 2026
SYNOPSIS: MID-LEVEL LOW PRESSURE FAVORED OVER THE NORTHEASTERN CONTIGUOUS U.S.
(CONUS), IS EXPECTED TO BRING ANOMALOUSLY COLD AIR AND GUSTY WINDS INTO PARTS
OF THE MIDWEST, LOWER GREAT LAKES REGION, AND APPALACHIANS LATE NEXT WEEK.
THERE ARE INCREASED CHANCES FOR MUCH BELOW NORMAL TEMPERATURES WITH FREEZING
AND NEAR FREEZING CONDITIONS POSSIBLE IN SOME AREAS, POTENTIALLY DAMAGING EARLY
SPRING BLOOMS.
HAZARDS
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR MUCH OF THE MIDWEST, LOWER
GREAT LAKES REGION, AND APPALACHIANS, THU-SAT, MAY 7-9.
SLIGHT RISK OF HIGH WINDS FOR MUCH OF THE EASTERN U.S., TUE-SAT, MAY 5-9.
DETAILED SUMMARY
FOR THURSDAY APRIL 30 - MONDAY MAY 04:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR TUESDAY MAY 05 - MONDAY MAY 11: MULTIPLE MODELS CONTINUE TO INDICATE
500-HPA HEIGHT FORECASTS WITH AMPLIFIED TROUGHING OVER THE NORTHEASTERN CONUS
AND RIDGING SOUTH OF GREENLAND DEVELOPING LATER IN THE WEEK. THIS PATTERN IS
EXPECTED TO PEAK LATE THIS WEEK BEFORE GRADUALLY WEAKENING, ALTHOUGH LINGERING
THROUGHOUT WEEK-2. THESE TWO MID-LEVEL HEIGHT FEATURES OVER NORTH AMERICA
ALIGNS WELL WITH A NEGATIVE NORTH AMERICAN OSCILLATION (-NAO) PATTERN, WHICH
DYNAMICALLY (AND HISTORICALLY) SUPPORTS THE ADVECTION OF ANOMALOUS COLD AIR
INTO MANY PARTS OF THE CENTRAL AND EASTERN CONUS. RELATIVE TO YESTERDAY,
ENSEMBLE MEANS GENERALLY DEPICT MORE EXPANSIVE TROUGHING ACROSS THE
NORTHEASTERN CONUS DURING THE MIDDLE OF WEEK-2. AS WARMER SOUTHERLY FLOW
ASSOCIATED WITH SURFACE LOWS SHIFT FROM THE MIDWEST TO THE EAST COAST BY
MID-PERIOD, SURFACE HIGH PRESSURE IS ANTICIPATED TO SINK SOUTHWARD FROM CENTRAL
CANADA INTO THE MIDWEST, BRINGING COLDER TEMPERATURES TO THE REGION. THEREFORE
A SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES IS HIGHLIGHTED ACROSS MUCH OF
THE MIDWEST, LOWER GREAT LAKES REGION, AND APPALACHIANS, MAY 7-9, WHERE BOTH
THE GEFS AND ECMWF PROBABILISTIC EXTREME TOOLS (PETS) INDICATE AT LEAST A 20%
CHANCE OF MINIMUM TEMPERATURES FALLING BELOW THE 15TH PERCENTILE
CLIMATOLOGICALLY AND 40 DEGREES F (FREEZING TEMPERATURES ACROSS THE NORTHERN
PORTIONS). ANY RESIDUAL COLD WITH FREEZING OR NEAR FREEZING TEMPERATURES MAY
THREATEN VULNERABLE SPRINGTIME VEGETATION, PARTICULARLY IN AREAS THAT HAVE
EXPERIENCED EARLY GROWTH DUE TO ANTECEDENT WARMTH DURING APRIL.
A SERIES OF SURFACE LOWS ARE PREDICTED TO DEVELOP ACROSS THE EASTERN CONUS TIED
TO THE TROUGHING ALOFT. THESE FEATURES MAY BRING EPISODES OF HIGH WINDS TO
PARTS OF THE EAST. THEREFORE A BROAD AREA REMAINS HIGHLIGHTED WITH A SLIGHT
RISK OF EPISODIC HIGH WINDS ACROSS THE EASTERN CONUS, MAY 5-9. PETS SHOW AT
LEAST A 20% CHANCE OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE ACROSS THE
REGION.
OVER ALASKA, MODELS CONTINUE TO FAVOR MID-LEVEL TROUGHING OVER THE BERING
STRAIT WITH RIDGING OVER THE MAINLAND. AN ASSOCIATED MEAN SURFACE LOW CENTERED
OVER THE ALEUTIANS IS EXPECTED TO BRING POTENTIALLY STRONG WINDS AND STORMY
CONDITIONS ALONG THE SOUTHWESTERN PORTIONS OF THE STATE EARLY IN WEEK-2 BEFORE
THE PATTERN ALOFT DEAMPLIFIES. CONDITIONS ARE EXPECTED TO REMAIN BELOW HAZARD
THRESHOLDS, AND NO CORRESPONDING WIND OR PRECIPITATION SHAPES ARE POSTED.
ADDITIONALLY, THE TYPICAL PEAK OF THE RIVER ICE BREAKUP SEASON IS APPROACHING,
AND ICE JAM FLOODING CAN OCCUR THIS TIME OF YEAR WITH LITTLE OR NO NOTICE AS
CONDITIONS ON FROZEN RIVERS CAN CHANGE QUICKLY. PLEASE CHECK WITH THE ALASKA
PACIFIC RIVER FORECAST CENTER FOR THE LATEST CONDITIONS AND ADVISORIES.
FORECASTER: MELISSA OU
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