922
FXUS21 KWNC 271850
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MAY 27 2025
SYNOPSIS: DYNAMICAL MODELS ARE TRENDING TOWARD A MORE AMPLIFIED MID-LEVEL
HEIGHT PATTERN ACROSS THE CONTIGUOUS U.S. (CONUS) DURING THE FIRST HALF OF
WEEK-2 COMPARED TO YESTERDAY. MID-LEVEL HIGH PRESSURE ANTICIPATED ACROSS THE
EAST FAVORS A PERIOD OF MUCH WARMER TEMPERATURES COMPARED TO CURRENT
CONDITIONS. MEANWHILE, MID-LEVEL LOW PRESSURE OVER THE WEST AND AN ASSOCIATED
FRONTAL SYSTEM ACROSS THE GREAT PLAINS IS PREDICTED TO INCREASE THE POTENTIAL
FOR EPISODES OF HEAVY PRECIPITATION AND THUNDERSTORMS ALONG THE TEMPERATURE
GRADIENT. ENHANCED WINDS ARE ALSO POSSIBLE AROUND THE BASE OF THE MID-LEVEL LOW
ACROSS THE ROCKIES, SOUTHWEST, AND HIGH PLAINS. THERE ARE STILL INDICATIONS OF
SOME ENHANCED TROPICAL MOISTURE TRACKING ACROSS FLORIDA AND ALONG THE CENTRAL
GULF COAST LATE IN WEEK-1 INTO THE OUTSET OF WEEK-2 POSSIBLY BRINGING EPISODES
OF HEAVY RAINFALL TO THESE AREAS.
HAZARDS
MODERATE RISK OF HEAVY PRECIPITATION ACROSS PORTIONS OF THE NORTHERN AND
CENTRAL PLAINS, UPPER AND MIDDLE MISSISSIPPI VALLEY, AND THE WESTERN GREAT
LAKES. WED-THU, JUN 4-5.
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS PORTIONS OF THE GREAT PLAINS,
MISSISSIPPI VALLEY, AND THE WESTERN GREAT LAKES, WED-FRI, JUN 4-6.
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS MUCH OF FLORIDA AND ALONG THE CENTRAL
GULF COAST, WED-THU, JUN 4-5.
SLIGHT RISK OF EXTREME HEAT ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI AND OHIO
VALLEYS, AND THE SOUTHERN GREAT LAKES, WED-FRI, JUN 4-6.
SLIGHT RISK OF HIGH WINDS ACROSS PORTIONS OF THE GREAT BASIN, SOUTHWEST,
CENTRAL AND SOUTHERN ROCKIES, AND THE HIGH PLAINS, WED-FRI, JUN 4-6.
DETAILED SUMMARY
FOR FRIDAY MAY 30 - TUESDAY JUNE 03:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR WEDNESDAY JUNE 04 - TUESDAY JUNE 10: BOTH THE 0Z ECENS AND GEFS HAVE
TRENDED TOWARD A MORE AMPLIFIED 500-HPA HEIGHT PATTERN ACROSS THE CONUS EARLY
IN WEEK-2 COMPARED TO YESTERDAY, WITH RIDGING (TROUGHING) PREDICTED ACROSS THE
EASTERN (WESTERN) HALF OF THE CONUS. RIDGING ACROSS THE EAST FAVORS A PERIOD OF
COMPARATIVELY WARMER TEMPERATURES THAN THOSE CURRENTLY BEING EXPERIENCED. THE
ECENS IS MOST BULLISH WITH REGARDS TO TEMPERATURES, INDICATING HIGHS WELL INTO
THE 80S DEG F, POSSIBLY CLOSE TO 90 DEG F, OVER PORTIONS OF THE MIDDLE
MISSISSIPPI AND OHIO VALLEYS, WITH SUPPORT FROM THE CORRESPONDING ECENS
PROBABILISTIC EXTREMES TOOL (PET). DESPITE THE GEFS BEING ON AVERAGE A FEW
DEGREES COOLER, INCREASING SOUTHERLY FLOW MAY PUSH DEWPOINTS CLOSE TO 70 DEG F
OVER SOME AREAS FURTHER INCREASING HEAT INDICES, IN ADDITION TO DRIER THAN
NORMAL SOILS ALSO RESULTING IN HIGHER TEMPERATURES. THEREFORE, A SLIGHT RISK OF
EXTREME HEAT IS INDICATED ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI AND OHIO
VALLEYS, AND THE SOUTHERN GREAT LAKES, JUN 4-6. WHILE THIS LEVEL OF HEAT WOULD
NOT BE CONSIDERED HAZARDOUS DURING THE MIDDLE OF SUMMER, THIS WOULD BE THE
FIRST ROUND OF ELEVATED HEAT FOR MUCH OF THE REGION, AND THE CHANGE FROM
ONGOING BELOW-NORMAL TEMPERATURES MAY CATCH SENSITIVE GROUPS OFF GUARD, FURTHER
JUSTIFYING THE HAZARD. MODELS INDICATE THESE WARMER TEMPERATURES SHIFTING
EASTWARD TOWARD THE MID-ATLANTIC BY DAY-10 (JUN 6), ALTHOUGH HIGHER HEAT HAZARD
THRESHOLDS IN THAT REGION PRECLUDE AN EXPANSION OF THE HAZARD.
TROUGHING OVER THE WESTERN CONUS FAVORS AN ACTIVE BAROCLINIC ZONE SETTING UP
ACROSS THE GREAT PLAINS AND MISSISSIPPI VALLEY. SEVERAL ROUNDS OF HEAVY
PRECIPITATION AND THUNDERSTORMS ARE POSSIBLE ACROSS THIS REGION, WITH THE
UNCALIBRATED 0Z ECENS DEPICTING PROBABILITIES OF AT LEAST 40 PERCENT FOR 3-DAY
PRECIPITATION TOTALS EXCEEDING 1-INCH ON DAYS 8 THROUGH 10 (JUN 4-6) OVER PARTS
OF THE REGION. THE ECENS AND GEFS PETS INDICATE AT LEAST A 20 PERCENT CHANCE OF
3-DAY PRECIPITATION TOTALS EXCEEDING THE 85TH CLIMATOLOGICAL PERCENTILE AND
1-INCH DURING THE SAME TIME FRAME. DESPITE THE PROBABILITIES IN THE PETS BEING
BELOW 40 PERCENT, A MODERATE RISK FOR HEAVY PRECIPITATION IS HIGHLIGHTED JUN
4-5 BASED ON SYNOPTIC PATTERN RECOGNITION AND CONSIDERATION OF SCALING ISSUES
IN THE PETS DUE TO POTENTIAL CONVECTIVE ACTIVITY. THE ANALOGUES BASED ON THE
WEEK-2 500-HPA HEIGHT PATTERN ALSO SUPPORT ENHANCED CHANCES OF ABOVE-NORMAL
PRECIPITATION ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST DURING WEEK-2,
SIGNIFYING A MORE ACTIVE PATTERN. A SLIGHTLY BROADER AREA IS HIGHLIGHTED WITH A
SLIGHT RISK FOR HEAVY PRECIPITATION CONTINUING THROUGH JUN 6.
EPISODES OF HIGH WINDS ARE POSSIBLE ALONG THE BASE OF THE TROUGH AXIS ACROSS
THE FOUR CORNERS EASTWARD INTO THE HIGH PLAINS. THE ECENS AND GEFS PETS AND
UNCALIBRATED TOOLS ARE IN GOOD AGREEMENT REGARDING ENHANCED CHANCES (AT LEAST
20 PERCENT) OF WIND SPEEDS EXCEEDING THE 85TH CLIMATOLOGICAL PERCENTILE AND
20-MPH, SUPPORTING A SLIGHT RISK OF HIGH WINDS ACROSS THESE AREAS, JUN 4-6. ANY
HIGH WINDS MAY LEAD TO A HEIGHTENED WILDFIRE RISK, ESPECIALLY ACROSS NEW MEXICO
AND SOUTHWESTERN TEXAS WHERE SOIL MOISTURE IS CURRENTLY BELOW THE 30TH
CLIMATOLOGICAL PERCENTILE.
MODELS CONTINUE TO INDICATE A WESTWARD MOVING SURFACE SYSTEM MOVING ACROSS
SOUTH FLORIDA LATE IN WEEK-1 INTO THE OUTSET OF WEEK-2. THIS FEATURE APPEARS TO
BE NON-TROPICAL AS IT ORIGINATES FROM A FRONTAL SYSTEM OFF THE ATLANTIC COAST,
AND MOST INDIVIDUAL ENSEMBLE MEMBERS FROM THE ECENS AND GEFS DO NOT DEPICT
SURFACE LOW CENTERS ASSOCIATED WITH THIS FEATURE. THERE IS GOOD MODEL SUPPORT
FOR THIS SYSTEM TO BRING ENHANCED RAINFALL ACROSS FLORIDA LATE IN WEEK-1,
POSSIBLY PERSISTING INTO WEEK-2. INTERACTION WITH THE UPSTREAM FRONTAL SYSTEM
ACROSS THE MIDWEST MAY ALLOW SOME NORTHWARD EXTENSION OF THE MOISTURE ALONG THE
CENTRAL GULF COAST. THE ECENS AND GEFS PETS DEPICT AT LEAST A 20 PERCENT CHANCE
OF 3-DAY PRECIPITATION TOTALS EXCEEDING THE 85TH PERCENTILE AND 1-INCH ACROSS
THESE AREAS THUS SUPPORTING A SLIGHT RISK OF HEAVY PRECIPITATION, JUN 4-5.
A RELATIVELY WEAK MID-LEVEL TROUGH IS FORECAST BY MOST DYNAMICAL MODELS TO
TRAVERSE ALASKA, WITH 500-HPA HEIGHTS REMAINING NEAR OR MARGINALLY BELOW
NORMAL. THIS FAVORS ENHANCED CHANCES OF BELOW-NORMAL TEMPERATURES AND NEAR-TO
ABOVE-NORMAL PRECIPITATION ACROSS THE STATE, WITH NO AREAS OF HAZARDOUS WEATHER
INDICATED.
FORECASTER: THOMAS COLLOW
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