514
FXUS21 KWNC 101914
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JUNE 10 2025
SYNOPSIS: PERSISTENT SURFACE HIGH PRESSURE OVER THE SOUTHEASTERN QUARTER OF THE
CONTIGUOUS U.S. (CONUS) IS FAVORED TO BRING WARM MOIST AIR AND WINDY CONDITIONS
INTO THE GREAT PLAINS, LEADING TO THE POTENTIAL FOR HEAVY PRECIPITATION ACROSS
THE NORTHERN TIER, AND FOR POTENTIALLY HAZARDOUS HIGH TEMPERATURES TO SEVERAL
REGIONS ACROSS THE LOWER 48. INCREASED TROPICAL MOISTURE ALSO BRINGS THE
POTENTIAL FOR HEAVY PRECIPITATION OVER SOUTHERN TEXAS. STRONG SURFACE HIGH
PRESSURE OVER THE NORTH PACIFIC MAY INDUCE HIGH WINDS ALONG MUCH OF THE
CALIFORNIA COAST.
HAZARDS
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE UPPER AND MIDDLE
MISSISSIPPI VALLEY AS WELL AS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS,
WED-SUN, JUN 18-22.
SLIGHT RISK OF HEAVY PRECIPITATION FOR SOUTHERN TEXAS, WED-FRI, JUN 18-20.
SLIGHT RISK OF EXTREME HEAT FOR PORTIONS OF THE DESERT SOUTHWEST, WED, JUN 18.
SLIGHT RISK OF EXTREME HEAT FOR MUCH OF THE CENTRAL PLAINS AND MIDDLE
MISSISSIPPI VALLEY AS WELL AS WESTERN PORTIONS OF THE GREAT LAKES AND OHIO
VALLEY, WED-SAT, JUN 18-21.
SLIGHT RISK OF EXTREME HEAT FOR THE SOUTHERN GREAT LAKES AND NORTHERN OHIO
VALLEY, THU-SAT, JUN 19-21.
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF THE SOUTHERN PLAINS, WED-TUE, JUN
18-24.
SLIGHT RISK OF HIGH WINDS FOR COASTAL REGIONS FROM MEDFORD, OR SOUTH TO POINT
CONCEPTION, WED-TUE, JUN 18-24.
DETAILED SUMMARY
FOR FRIDAY JUNE 13 - TUESDAY JUNE 17:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR WEDNESDAY JUNE 18 - TUESDAY JUNE 24: THE GEFS, ECMWF, AND CMCE ARE IN
REASONABLE AGREEMENT WITH REGARD TO THE OVERALL SYNOPTIC PATTERN AS DEPICTED BY
500-HPA HEIGHT ANOMALIES DESPITE SOME SIGNIFICANT DIFFERENCES. THE MODELS AGREE
ON THE PRESENCE OF A SHORTWAVE TROUGH OVER THE WEST COAST AT THE OUTSET OF
WEEK-2, ALTHOUGH THEY SHARPLY DISAGREE WITH REGARD TO THE AMPLITUDE AND
MOVEMENT OF THIS FEATURE. ENSEMBLE SOLUTIONS ALSO ARE IN GOOD AGREEMENT WITH
RESPECT TO A STRONG BERMUDA HIGH ENABLING MOIST AIR TO MOVE OFF THE GULF AND
INTO THE MIDDLE OF THE CONUS, BUT DISAGREE WITH RESPECT TO THE LOCATION AND
INTENSITY OF ANY PRECIPITATION ASSOCIATED WITH THIS TROPICAL INFLOW. THE BEST
AGREEMENT AMONG THE MODELS IS IN FAVORING WIDESPREAD POSITIVE HEIGHT ANOMALIES
ACROSS THE SOUTHERN HALF OF THE CONUS FOR MUCH OF WEEK-2, LEADING TO THE
POTENTIAL FOR EXTREME HEAT FOR SEVERAL REGIONS ACROSS THE LOWER 48.
LATE IN WEEK-1 A MID-LEVEL RIDGE BUILDING OVER THE DESERT SOUTHWEST LEADS TO A
CHANCE OF EXTREME HEAT FOR THIS REGION EARLY IN WEEK-2. THE PROBABILISTIC
EXTREMES TOOLS (PETS) FROM THE ECMWF AND GEFS INDICATE AT LEAST A 20%
PROBABILITY OF HIGH TEMPERATURES TO EXCEED THE 85TH CLIMATOLOGICAL PERCENTILE
AND ABSOLUTE TEMPERATURES OF 95F FOR EASTERN NEW MEXICO, 100-105F FOR WESTERN
TEXAS AND SOUTHERN NEW MEXICO, AND OVER 105F FOR SOUTHERN ARIZONA. THIS EVENT
IS SHORT-LIVED AS THE WEST COAST TROUGH QUICKLY WEAKENS THE DESERT RIDGE.
THEREFORE, A SLIGHT RISK OF EXTREME HEAT IS POSTED FOR MUCH OF NEW MEXICO AND
PORTIONS OF WESTERN TEXAS AND SOUTHERN ARIZONA FOR JUN 18. THE ECMWF AND GEFS
ALSO INDICATE GENERALLY BREEZY CONDITIONS OVER THE DESERT SOUTHWEST AND
SOUTHERN GREAT BASIN. WHILE HAZARDOUS THRESHOLDS ARE NOT EXPECTED TO BE MET,
INCREASED WINDS WOULD NONETHELESS INCREASE THE RISK FOR WILDFIRES PARTICULARLY
WITH EXPECTED EXTREME HEAT.
POSITIVE HEIGHT ANOMALIES OVER THE SOUTHEASTERN CONUS ALSO FAVOR ANOMALOUSLY
WARM TEMPERATURES ALMOST UNIVERSALLY EAST OF THE ROCKIES, AND GULF MOISTURE
STREAMING IN WITH ASSISTANCE FROM A STRONG BERMUDA HIGH IS LIKELY TO MAKE FOR
UNCOMFORTABLE AND IN SOME CASES DANGEROUS HEAT. THE GEFS AND ECMWF PETS BOTH
INDICATE AT LEAST A 20% CHANCE OF HIGH TEMPERATURES EXCEEDING THE 85TH
PERCENTILE AND AT LEAST 90F FOR A BROAD SWATH FROM THE CENTRAL PLAINS THROUGH
THE OHIO VALLEY. THE GEFS FAVORS THESE CONDITIONS THROUGHOUT THESE REGIONS FOR
THE FIRST HALF OF WEEK-2, WHILE THE ECMWF PREFERS A MORE PROGRESSIVE SOLUTION,
MOVING THE HAZARDOUS HEAT INTO THE OHIO VALLEY A LITTLE MORE SLOWLY AND
GENERALLY KEEPING MAXIMUM TEMPERATURES SLIGHTLY LOWER THAN THE GEFS. FOR BOTH
REGIONS AND IN BOTH MODELS THE SIGNAL BEGINS TO DROP OFF TOWARDS THE END OF
WEEK-2. A SLIGHT RISK OF EXTREME HEAT IS POSTED FOR MUCH OF THE CENTRAL PLAINS
AND MIDDLE MISSISSIPPI VALLEY FOR JUN 18-21, AND FOR THE OHIO VALLEY AND
SOUTHERN GREAT LAKES FOR JUN 19-21. ABNORMALLY WARM TEMPERATURES AND HIGH
HUMIDITIES ARE ALSO FAVORED TO SPREAD EAST INTO MUCH OF THE MID-ATLANTIC
CONCURRENT WITH THE WARM-UP IN THE OHIO VALLEY. WHILE THE PETS INDICATE AT
LEAST 20% CHANCE OF MAX TEMPERATURES TO EXCEED THE 85TH PERCENTILE, HAZARDOUS
THRESHOLDS ARE NOT LIKELY TO BE MET SO THE SLIGHT RISK OF EXTREME HEAT POSTED
YESTERDAY FOR THIS REGION HAS BEEN REMOVED, ALTHOUGH THE SITUATION WILL
CONTINUE TO BE MONITORED CLOSELY.
AT THE BEGINNING OF WEEK-2 MODELS DEPICT THE TROUGH OVER THE WESTERN CONUS AS
POTENTIALLY PROVIDING INCREASED INSTABILITY OVER THE GREAT PLAINS AND
INTERACTING WITH THE ABUNDANT GULF MOISTURE IN PLACE TO PRODUCE HEAVY
PRECIPITATION. THIS IS WELL-INDICATED BY THE ECMWF AND GEFS PETS AS WELL AS
UNCALIBRATED PROBABILITIES INDICATING AT LEAST A 20% CHANCE OF 3-DAY
PRECIPITATION TOTALS TO EXCEED 1 INCH AT THE BEGINNING OF WEEK-2 FOR MUCH OF
THE MIDDLE MISSISSIPPI VALLEY, AS WELL AS FOR MUCH OF SOUTH TEXAS. THE GEFS IS
LESS BULLISH WITH REGARD TO THE POTENTIAL FOR HEAVY PRECIPITATION OVER THE
MISSISSIPPI VALLEY BUT IS IN BETTER AGREEMENT FOR SOUTH TEXAS. DISAGREEMENT
NOTWITHSTANDING, A SLIGHT RISK OF HEAVY PRECIPITATION IS POSTED FOR BOTH
REGIONS, COVERING JUN 18-20 FOR SOUTH TEXAS AND JUN 18-22 FOR THE MIDDLE AND
UPPER MISSISSIPPI VALLEY. IN SOUTH TEXAS, DUE TO THE SHORT TIME IN WHICH THIS
PRECIPITATION IS EXPECTED TO FALL AND THE NATURE OF THE WATERSHEDS INVOLVED
THERE IS THE POTENTIAL FOR LOCALIZED FLASH FLOODING, WHILE ABUNDANT ANTECEDENT
RAINFALL OVER THE MIDDLE MISSISSIPPI VALLEY AND CENTRAL PLAINS RESULTS IN THE
POTENTIAL FOR NEW OR RENEWED FLOODING IN THIS REGION. UNCERTAINTY IS TOO HIGH
TO HIGHLIGHT A PARTICULAR AREA FOR A FLOODING POSSIBLE HAZARD BUT THE SITUATION
WILL CONTINUE TO BE MONITORED CLOSELY.
MODELS GENERALLY DEPICT FAIRLY STRONG WINDS AT THE SOUTHERN END OF THE GULF
MOISTURE INFLOW. WHILE THE PETS ARE RATHER MIXED, ENSEMBLE MEAN WIND SPEEDS
FROM THE ECMWF AND GEFS BOTH INDICATE PEAK DAILY WIND SPEEDS OF AT LEAST 20MPH
OVER WESTERN PORTIONS OF THE SOUTHERN PLAINS THROUGHOUT THE FORECAST PERIOD,
THEREFORE A SLIGHT RISK OF HIGH WIND IS POSTED FOR THIS REGION FOR ALL OF
WEEK-2. ENSEMBLE MEAN WIND SPEEDS ARE ALSO ELEVATED ALONG THE WEST COAST DURING
ALL OF WEEK-2 WITH WIND SPEEDS OF 25-30MPH ALONG THE IMMEDIATE COAST FROM
MEDFORD, OR SOUTH TO POINT CONCEPTION IN CALIFORNIA, ALSO FOR ALL OF WEEK-2.
ICE-BOUND RIVERS ARE BEGINNING TO BREAK UP IN THE NORTH SLOPE OF ALASKA. THERE
IS NO ASSOCIATED HAZARD POSTED AT THIS TIME BUT THIS SITUATION WILL BE CLOSELY
MONITORED IN THE COMING DAYS AND WEEKS AS CONDITIONS CAN QUICKLY CHANGE,
LEADING TO THE POTENTIAL FOR ICE JAMS, AUFEIS, AND ASSOCIATED FLOODING.
FORECASTER: DANNY BARANDIARAN
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