570
FXUS21 KWNC 021839
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JULY 02 2026
SYNOPSIS: REBUILDING MID-LEVEL HIGH PRESSURE OVER PARTS OF THE WESTERN AND
CENTRAL CONTIGUOUS U.S. (CONUS) SUPPORTS INCREASED EXTREME HEAT RISK FROM THE
INTERIOR WEST INTO PARTS OF THE GREAT PLAINS THROUGHOUT WEEK-2, WITH A MODERATE
RISK IDENTIFIED FOR MUCH OF THIS AREA AROUND THE MIDDLE OF THE PERIOD. FURTHER
SOUTHEAST, ENHANCED SUBTROPICAL HIGH PRESSURE ALSO ENHANCES THE EXTREME HEAT
RISK ACROSS THE GULF COAST, THE FLORIDA PENINSULA, AND THE SOUTH ATLANTIC
COAST. MEANWHILE, SURFACE LOW DEVELOPMENT AND AN ACCOMPANYING HEAVY
PRECIPITATION RISK IS POSSIBLE EARLY OVER THE EASTERN CAROLINAS. NEAR THE WEST
COAST, STRENGTHENING PRESSURE GRADIENTS ARE FORECAST, WHICH INCREASES THE RISK
FOR EPISODES OF HIGH WINDS.
HAZARDS
MODERATE RISK OF EXTREME HEAT ACROSS MUCH OF THE INTERIOR WEST AND GREAT
PLAINS, SUN-WED, JUL 12-15.
SLIGHT RISK OF EXTREME HEAT ACROSS MUCH OF THE INTERIOR WEST, ROCKIES, PLAINS,
GULF COAST, AND SOUTH ATLANTIC COAST, FRI-THU, JUL 10-16.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE MID-ATLANTIC AND THE
SOUTHEAST, FRI-SAT, JUL 10-11.
SLIGHT RISK OF EPISODIC HIGH WINDS ALONG AND NEAR THE WEST COAST, FRI-THU, JUL
10-16.
DETAILED SUMMARY
FOR SUNDAY JULY 05 - THURSDAY JULY 09:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY JULY 10 - THURSDAY JULY 16: FOLLOWING A SIGNIFICANT HEAT EVENT THAT
IS FORECAST TO AFFECT MUCH OF THE CENTRAL AND EASTERN CONUS DURING WEEK-1,
MODELS FAVOR A BUILDING, SLOWLY-RETROGRADING 500-HPA RIDGE BY EARLY WEEK-2.
ANOMALOUSLY WARM TEMPERATURES AND POTENTIAL EXTREME HEAT CONDITIONS ARE MAINLY
FAVORED ALONG A MEAN RIDGE AXIS THAT BECOME RE-ESTABLISHED OVER THE CENTRAL AND
WESTERN CONUS TOWARDS THE MIDDLE OF THE PERIOD. AROUND THE CUSP OF WEEKS 1 AND
2 (JUL 9-10), MUCH OF THE RIDGING IS FAVORED TO DEAMPLIFY TEMPORARILY. THIS IS
EXEMPLIFIED BY BOTH THE GEFS AND THE EUROPEAN ENSEMBLE (ECENS), ABOUT THE SAME
AS YESTERDAY. HOWEVER, THIS DEAMPLIFICATION APPEARS ONLY TEMPORARY, AS MODEL
SOLUTIONS SUPPORT A REBUILDING MID-LEVEL RIDGE THAT DRIFTS OVER THE CENTRAL AND
INTERIOR WESTERN CONUS TOWARDS THE MIDDLE OF WEEK-2. THE DYNAMICAL EUROPEAN
MODEL (ECMWF) IS MOST BULLISH WITH THIS RESTRENGTHENING AND STRONGER THAN
YESTERDAY, FEATURING A 601 DM HEIGHT FIELD MAXIMUM OVER THE EASTERN FOUR
CORNERS AROUND DAYS 11-12 (JUL 13-14). THE GEFS AND EUROPEAN ENSEMBLE (ECENS)
MEANS ARE ONLY SLIGHTLY MORE MUTED, PEAKING AT 597 AND 598 DM, RESPECTIVELY,
AROUND THIS TIME. THE PATTERN SUPPORTS A SLIGHT RISK OF EXTREME HEAT THROUGHOUT
WEEK-2 ACROSS A LARGE PART OF THE CENTRAL AND WESTERN CONUS, WITH A MODERATE
RISK OF EXTREME HEAT DURING THE MIDDLE OF WEEK-2, WHEN MODELS ARE IN BEST
AGREEMENT ON THE TIMING AND LOCATION OF THE AMPLIFIED MID-LEVEL RIDGE. THE
ECMWF FORECASTS DAILY HIGHS PEAKING AT 110 TO 115 DEG F IN MUCH OF THE
CALIFORNIA VALLEYS, AND NEAR 120 DEG F IN PARTS OF THE DESERT SOUTHWEST. THE
ECMWF FORECASTS TEMPERATURES APPROACHING 110 DEG F AT TIMES AS FAR NORTH AS
WESTERN SOUTH DAKOTA AND THE LOWER ELEVATIONS OF SOUTHEASTERN WASHINGTON, BUT
OTHER TOOLS ARE NOT AS ROBUST IN THESE AREAS, SO THE MODERATE RISK AREA DOES
NOT EXTEND THAT FAR NORTH. THE LARGEST MID-LEVEL HEIGHT ANOMALIES ARE FORECAST
TO BE NEAR THE CENTRAL ROCKIES AROUND THE MIDDLE OF WEEK-2, BUT THIS AREA OF
MOSTLY HIGHER ELEVATIONS IS AT LOWER RISK OF TEMPERATURES REACHING HAZARDS
CRITERIA DESPITE BEING WELL ABOVE NORMAL.
ACROSS THE LOWER LATITUDES, ENHANCED SUBTROPICAL RIDGING NEAR THE SOUTHEAST AND
WESTERN ATLANTIC SUPPORTS A SLIGHT RISK OF EXTREME HEAT THROUGHOUT WEEK-2
ACROSS THE GULF AND SOUTH ATLANTIC COASTS. THE PROBABILISTIC EXTREMES TOOL
(PET) FROM THE ECENS IS CONSIDERABLY MORE ROBUST WITH THE HEAT SIGNAL THAN THE
PETS FROM THE GEFS AND THE CANADIAN ENSEMBLE (CMCE) ACROSS THE FLORIDA
PANHANDLE, PEAKING IN THE 40 TO 60 PERCENT RANGE IN THE ECENS BUT GENERALLY THE
20 TO 40 PERCENT RANGE IN THE OTHER PETS, AND ONLY FOR A COUPLE DAYS. THIS
IMPLIES A SLIGHTLY BETTER CHANCE FOR EXTREME HEAT IN THE FLORIDA PENINSULA THAN
OTHER PARTS OF THE SOUTHEAST, BUT A MODERATE RISK AREA IS NOT SUPPORTED BY A
PREPONDERANCE OF THE TOOLS, SO ONLY A SLIGHT RISK IS POSTED. STILL, INTERNAL
HEAT GUIDANCE SHOWS THE COMBINATION OF HIGH TEMPERATURES AND HUMIDITIES COULD
PUSH HEAT INDICES ABOVE 105 DEG F FROM THE SOUTHERN PLAINS TO THE SOUTH
ATLANTIC COAST.
DOWNSTREAM OF THE ANOMALOUS RIDGING OVER THE WESTERN AND CENTRAL CONUS, SOME
DEGREE OF MID-LEVEL TROUGHING IS FAVORED OVER THE EASTERN CONUS NORTH OF THE
GULF COAST REGION, WHERE SOME ENSEMBLE MEMBERS CONTINUE TO SUPPORT SURFACE LOW
DEVELOPMENT THAT COULD POTENTIALLY AFFECT PARTS OF THE SOUTH ATLANTIC COAST
EARLY WEEK-2. OVERALL, HOWEVER, MODELS ARE A LITTLE LESS INDICATIVE OF THIS
SCENARIO THAN YESTERDAY, AND ENSEMBLE MEANS ARE PLACING THE HEAVIEST
PRECIPITATION OFF THE SOUTH ATLANTIC COAST. ENHANCED PRECIPITATION IS FAVORED
TO ACCOMPANY ANY DEVELOPING SURFACE LOW, WHICH SUFFICIENTLY INCREASES THE ODDS
FOR HEAVY PRECIPITATION EARLY WEEK-2 TO JUSTIFY POSTING A SLIGHT RISK ACROSS
THE EASTERN CAROLINAS DURING THE FIRST TWO DAYS OF THE PERIOD (JUL 10-11). THIS
IS RESTRICTED FARTHER TO THE EAST THAN YESTERDAY.
ACROSS THE DESERT SOUTHWEST, THE PETS ALL HIGHLIGHT SOME POTENTIAL FOR
ABOVE-NORMAL PRECIPITATION ACROSS PARTS OF THE SOUTHWEST, BUT CHANCES FOR
TOTALS TO EXCEED HAZARDS THRESHOLDS ARE LIMITED. IN ADDITION, RAW PRECIPITATION
FORECASTS FROM THE MODELS KEEP AMOUNTS UNDER AN INCH FOR WEEK-2 AS A WHOLE. THE
SIGNAL FOR INCREASED PRECIPITATION ALIGNS WELL WITH THE TIME MODELS FAVOR THE
PEAK STRENGTH OF THE REAMPLIFYING WESTERN CONUS RIDGE, AND SUGGESTS A MORE
ACTIVE MONSOONAL CIRCULATION LATER IN WEEK-2. BUT THE CONTINUED LACK OF ROBUST
SUPPORT IN THE RAW TOOLS AND PETS, NO CORRESPONDING PRECIPITATION HAZARDS ARE
POSTED. LOCALIZED THUNDERSTORMS ARE STILL POSSIBLE AND THIS AREA WILL CONTINUE
TO BE MONITORED FOR INCREASES IN MODEL FORECASTS OF PRECIPITABLE WATER AND
RAINFALL TOTALS.
SURFACE HIGH PRESSURE DEVELOPMENT OFF THE WEST COAST IS EXPECTED TO COINCIDE
WITH THERMALLY- INDUCED LOW PRESSURE CENTERED OVER THE SOUTHWEST. THE RESULTING
PRESSURE GRADIENT INCREASES THE CHANCES FOR EPISODES OF HIGH WINDS THROUGHOUT
WEEK-2 OVER PARTS OF THE FAR WEST FROM THE WESTERN FRINGES OF THE AREA AT
INCREASED RISK OF EXTREME HEAT TO THE PACIFIC COAST. THE GEFS, ECENS, AND CMCE
PETS CONTINUE TO INDICATE AT LEAST A 20 PERCENT CHANCE OF WIND SPEEDS EXCEEDING
THE 85TH CLIMATOLOGICAL PERCENTILE AT VARIOUS TIMES AND LOCATIONS FOR THE
DURATION OF WEEK-2 IN THE AFFECTED AREAS, WITH THE ECENS PET DEPICTING ODDS
EXCEEDING 30 PERCENT TOWARD THE MIDDLE OF WEEK-2 ALONG CENTRAL SECTIONS OF THE
WEST COAST. THEREFORE, A SLIGHT RISK OF HIGH WINDS REMAINS POSTED ACROSS THIS
REGION JUL 10-16. IT SHOULD BE NOTED THAT IF THERE IS A SUBSTANTIAL INCREASE IN
MONSOONAL MOISTURE AND PRECIPITATION, SOMEWHAT COOLER TEMPERATURES WOULD
RESULT, LIKELY REDUCING THE STRENGTH OF THE THERMAL LOW PRESSURE AND WEAKENING
THE HIGH WIND POTENTIAL.
FORECASTER: RICH TINKER
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