368
FXUS21 KWNC 221815
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT APRIL 22 2026
SYNOPSIS: A SLOW-MOVING FRONTAL BOUNDARY IS FORECAST TO INTERACT WITH MOIST
SOUTHERLY FLOW EARLY IN WEEK-2, INCREASING THE POTENTIAL OF HEAVY PRECIPITATION
FROM PORTIONS OF THE SOUTHERN PLAINS EASTWARD AND NORTHEASTWARD TO THE SPINE OF
THE CENTRAL AND SOUTHERN APPALACHIANS AND ADJACENT PARTS OF THE SOUTHEAST.
BEHIND THE FRONT, UNSEASONABLY COOL SURFACE HIGH PRESSURE IS EXPECTED TO SETTLE
INTO THE CENTRAL AND EASTERN CONTIGUOUS UNITED STATES (CONUS), RESULTING IN AN
ELEVATED RISK OF MUCH BELOW NORMAL TEMPERATURES AND THE POTENTIAL FOR FROST OR
FREEZE DAMAGE TO EARLY BLOOMS. LATER IN WEEK-2, SOUTHERLY RETURN FLOW INTO THE
CENTRAL AND INTERIOR EASTERN CONUS COULD TRIGGER HEAVY PRECIPITATION, BUT THERE
IS TOO MUCH UNCERTAINTY TO POST ANY ADDITIONAL HAZARDS AT THIS TIME.
HAZARDS
SLIGHT RISK OF HEAVY PRECIPITATION FROM PORTIONS OF THE SOUTHERN PLAINS
EASTWARD THROUGH PARTS OF THE MISSISSIPPI, TENNESSEE, AND OHIO VALLEYS, INTO
ADJACENT PARTS OF THE SOUTHEAST AND THE CENTRAL AND SOUTHERN APPALACHIANS, THU,
APR 30.
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FROM PORTIONS OF THE CENTRAL
PLAINS EASTWARD THROUGH THE LOWER GREAT LAKES, OHIO VALLEY, AND NORTHERN
MID-ATLANTIC, THU-SUN, APR 30-MAY 3.
DETAILED SUMMARY
FOR SATURDAY APRIL 25 - WEDNESDAY APRIL 29:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY APRIL 30 - WEDNESDAY MAY 06: ENSEMBLE SOLUTIONS FROM THE ECENS AND
GEFS FOR 500-HPA HEIGHT ANOMALIES DEPICT A SHORTWAVE TROUGH MOVING TOWARD THE
GREAT LAKES BY THE OUTSET OF THE WEEK-2 PERIOD, WITH AN ACCOMPANYING SURFACE
LOW PRESSURE AND A TRAILING COLD FRONT. MODELS GENERALLY SHOW THIS FRONTAL
BOUNDARY MOVING SOUTHWARD THROUGH THE SOUTHERN GREAT PLAINS, PARTS OF THE
MISSISSIPPI AND TENNESSEE VALLEYS, AND ADJACENT SECTIONS OF THE SOUTHERN AND
EASTERN CONUS INTO THE CENTRAL AND SOUTHERN APPALACHIANS. THESE FEATURES ARE
NOT HIGHLY AMPLIFIED, BUT ARE EXPECTED TO COINCIDE WITH MODERATE SOUTHERLY FLOW
WEST OF A SURFACE HIGH PRESSURE SYSTEM OVER THE WESTERN NORTH ATLANTIC. THIS
RETURN FLOW IS ANTICIPATED TO INCREASE MOISTURE AVAILABLE TO THE FRONTAL
SYSTEM, ENHANCING PRECIPITATION TOTALS. THE PROBABILISTIC EXTREMES TOOLS (PETS)
FROM THE GEFS, CANADIAN ENSEMBLE (CMCE), AND EUROPEAN ENSEMBLE (ECENS) SHOW 20
TO 30 PERCENT PROBABILITIES OF PRECIPITATION ACCUMULATIONS EXCEEDING 1 INCH
EARLY IN WEEK-2 OVER MUCH OF THE LOWER MISSISSIPPI VALLEY AND SOME ADJACENT
AREAS. THE ECENS MEAN DEPICTS 0.5 TO 1.5 INCHES OF RAIN OVER PARTS OF THE
MISSISSIPPI, TENNESSEE, AND OHIO VALLEYS WHILE THE DETERMINISTIC 0Z EUROPEAN
MODEL (ECMWF) SHOWS LOCALIZED AREAS OF 2.0 TO 3.5 INCHES ACROSS PARTS OF
ARKANSAS, MISSISSIPPI, AND TENNESSEE. OTHER TOOLS GENERALLY SUPPORT THE
POTENTIAL FOR HEAVY RAIN, BUT ARE ONLY IN FAIR AGREEMENT ON THE LOCATION AND
TOTALS OF THE HIGHEST AMOUNTS. THESE FACTORS SUPPORT A SLIGHT RISK OF HEAVY
PRECIPITATION IN THE AFOREMENTIONED AREAS APR 30 (DAY 8). BY MAY 1, THE COLD
FRONT IS EXPECTED TO HAVE WEAKENED AND CLEARED THE GULF AND SOUTH ATLANTIC
COASTS, ENDING THE HEAVY RAIN THREAT. ISOLATED, BRIEF HIGH WIND GUSTS ARE
POSSIBLE IN POTENTIALLY STRONG THUNDERSTORMS, BUT GUIDANCE DOES NOT SUPPORT
WIDESPREAD HIGH WINDS FOR ANY SIGNIFICANT DURATION, SO NO HIGH WIND HAZARD IS
POSTED.
AS THE COLD FRONT CLEARS THE SOUTHERN AND EASTERN CONUS, SOME MODELS SHOW A
SURFACE LOW PRESSURE SYSTEM FORMING SOMEWHERE OVER OR NEAR THE EASTERN CONUS
THAT GETS PICKED UP BY THE NEGATIVELY-TILTED MID-LEVEL TROUGH MOVING TOWARD THE
GREAT LAKES AND NEW ENGLAND. IF A SIGNIFICANT SURFACE STORM SYSTEM DEVELOPS,
HEAVY PRECIPITATION COULD AFFECT ALL OR PART OF THE GREAT LAKES AND ATLANTIC
SEABOARD, PARTICULARLY IN THE NORTHEASTERN CONUS WHICH WILL BE DOWNSTREAM FROM
THE MID-LEVEL TROUGH. AT THIS TIME, THERE IS TOO MUCH UNCERTAINTY TO JUSTIFY
POSTING ANY HAZARDS, AND IN FACT THERE IS LESS SUPPORT FOR THIS SCENARIO THAN
YESTERDAY, BUT THE SITUATION WILL CONTINUE TO BE MONITORED.
UNSEASONABLY COOL SURFACE HIGH PRESSURE IS EXPECTED TO SETTLE INTO MOST OF
CENTRAL AND EASTERN CONUS BEHIND THE FRONT, ACCOMPANIED BY MUCH BELOW NORMAL
TEMPERATURES. TEMPERATURE ANOMALIES OF -10 TO -20 DEG. F ARE POSSIBLE AT TIMES
FROM THE PLAINS THROUGH THE APPALACHIANS AND NORTHEAST, AS DEPICTED BY THE
ECMWF AND MANY ECENS MEMBERS. GIVEN THE ABSOLUTE TEMPERATURES FORECAST, IT
APPEARS THAT HAZARDOUS CONDITIONS WILL BE LIMITED TO AREAS AT RISK OF A FROST
OR HARD FREEZE THAT HAVE EARLY SPRING BLOOMING DUE TO THE WARM APRIL. A SLIGHT
RISK OF MUCH BELOW NORMAL TEMPERATURES IS POSTED FOR THESE AREAS, WHICH STRETCH
FROM THE CENTRAL PLAINS EASTWARD THROUGH PARTS OF THE GREAT LAKES AND OHIO
VALLEYS THROUGH THE NORTHERN MID-ATLANTIC REGION. THE HIGH PRESSURE SYSTEM IS
FORECAST TO DRIFT EAST OF THE CONUS AND WEAKEN AROUND THE MIDDLE OF WEEK-2,
ENDING THE COLD WEATHER THREAT.
THE SURFACE HIGH PRESSURE COULD BE ACCOMPANIED BY BREEZY CONDITIONS AS IT PULLS
COLDER AIR SOUTHWARD INTO THE CENTRAL AND EASTERN CONUS. WINDS ARE NOT EXPECTED
TO REACH HAZARDS THRESHOLDS, BUT LARGE PORTIONS OF THIS REGION ARE ENTRENCHED
IN SOME DEGREE OF DROUGHT. THE COMBINATION OF DRY AND BREEZY CONDITIONS OVER
PARTS OF THE CENTRAL AND EASTERN CONUS WHERE THERE IS ANTECEDENT DRYNESS
SIGNIFICANTLY INCREASES THE RISK OF WILDFIRE ACTIVITY, WHICH COULD SPREAD
RAPIDLY. CARE SHOULD BE TAKEN TO MINIMIZE THE CHANCES OF WILDFIRE IGNITION.
LATER IN WEEK-2, MANY TOOLS, INCLUDING THE ECMWF AND TO A LESSER EXTENT THE
ENSEMBLES, SHOW RETURN SOUTHERLY FLOW DEVELOPING OVER THE CENTRAL AND INTERIOR
EASTERN CONUS WHICH MAY INTERACT WITH A DEVELOPING FRONTAL COMPLEX, POTENTIALLY
TRIGGERING AREAS OF HEAVY PRECIPITATION. AT THIS TIME, MOST TOOLS FAVOR
SUB-HAZARDOUS PRECIPITATION TOTALS WITH THIS SYSTEM, AND THERE REMAINS POOR
MODEL AGREEMENT REGARDING THE LOCATION AND TIMING OF HEAVIER AMOUNTS. THIS
PRECLUDES POSTING ANY ADDITIONAL RELATED HAZARDS AT THIS TIME.
SIGNIFICANT MODEL DISAGREEMENT DEVELOPS WITH TIME ACROSS ALASKA. THE ECENS MEAN
SHOWS A CLOSED MID-LEVEL LOW APPROACHING THE STATE BY LATE IN THE PERIOD,
POTENTIALLY TRIGGERING SURFACE STORM DEVELOPMENT AND STORMY WEATHER ALONG THE
SOUTHERN TIER OF THE STATE. MEANWHILE, THE CMCE AND GEFS MEANS ARE MUCH
DIFFERENT, SHOWING SLOWLY BUILDING HEIGHTS AND NONDESCRIPT WEATHER STATEWIDE
LATER IN WEEK-2. THE UNCERTAINTY AND LACK OF AMPLIFIED MID-LEVEL FLOW PRECLUDE
POSTING ANY HAZARDS; HOWEVER, 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. CHECK WITH THE
ALASKA PACIFIC RIVER FORECAST CENTER FOR THE LATEST CONDITIONS AND ADVISORIES.
FORECASTER: RICH TINKER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page