689
FXUS21 KWNC 251822
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JUNE 25 2025
SYNOPSIS: TIED TO AN ACTIVE NORTH AMERICAN MONSOON CIRCULATION HEADING INTO
JULY, AS WELL AS A POTENTIAL INFLUX OF TROPICAL MOISTURE FROM THE EASTERN
PACIFIC, THERE ARE ELEVATED CHANCES FOR ABOVE-NORMAL AND LOCALLY HEAVY
PRECIPITATION OVER THE SOUTHWESTERN CONTIGUOUS U.S. (CONUS). ANY HEAVY
PRECIPITATION MAY TRIGGER LOCALIZED FLOODING AND EXACERBATE SATURATED GROUND
CONDITIONS ACROSS THE LOWER FOUR CORNERS DURING WEEK-2. MID-LEVEL HIGH
PRESSURE FAVORED OVER SOUTHWESTERN CANADA AND OVER THE GULF OF AMERICA IS
EXPECTED TO BRING ABOVE-NORMAL SUMMERTIME TEMPERATURES WITH POSSIBLE EXTREME
HEAT CONDITIONS FOR PORTIONS OF THE NORTHWESTERN AND SOUTHCENTRAL CONUS DURING
THE PERIOD. STALLED FRONTAL ACTIVITY NEAR THE SOUTHEASTERN U.S. MAY LEAD TO
LOCALLY HEAVY PRECIPITATION FROM THE EASTERN GULF TO THE COASTAL CAROLINAS.
HAZARDS
HIGH RISK OF HEAVY PRECIPITATION FOR PARTS OF THE DESERT SOUTHWEST, THU, JUL 3.
MODERATE RISK OF HEAVY PRECIPITATION FOR PARTS OF THE DESERT SOUTHWEST,
THU-FRI, JUL 3-4.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE DESERT SOUTHWEST, ROCKIES,
AND GREAT BASIN, THU-WED, JUL 3-9.
SLIGHT RISK OF EXTREME HEAT OVER PORTIONS OF THE NORTHERN INTERMOUNTAIN AND
NORTHERN PLAINS, THU-FRI, JUL 3-4.
SLIGHT RISK OF EXTREME HEAT OVER PARTS OF THE SOUTHERN PLAINS AND LOWER
MISSISSIPPI VALLEY, FRI-MON, JUL 4-7.
SLIGHT RISK OF HEAVY PRECIPITATION IN PARTS OF THE EASTERN GULF COAST REGION,
AND LOWER EASTERN SEABOARD, THU-SAT, JUL 3-5.
SLIGHT RISK OF HIGH WINDS ALONG MOST OF THE IMMEDIATE WEST COAST, THU-MON, JUL
3-7.
FLOODING POSSIBLE OVER PORTIONS OF ARIZONA AND NEW MEXICO.
DETAILED SUMMARY
FOR SATURDAY JUNE 28 - WEDNESDAY JULY 02:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY JULY 03 - WEDNESDAY JULY 09: HEADING INTO WEEK-2, THERE CONTINUES
TO BE FAIR AGREEMENT IN BOTH THE GEFS AND ECMWF DEPICTING AN ANOMALOUS 500-HPA
RIDGE CENTER OVER SOUTHWESTERN CANADA, WITH WEAKNESSES IN THE 500-HPA HEIGHT
FIELDS OVER THE SUBTROPICS. WITH CONTINUED INDICATIONS OF 700-HPA INVERTED
TROUGHING OVER THE LOWER FOUR CORNERS AND NORTHERN MEXICO, THESE FEATURES ARE
CHARACTERISTIC OF AN ACTIVE NORTH AMERICAN MONSOON CIRCULATION, WHERE THERE
CONTINUES TO BE ELEVATED CHANCES FOR ABOVE-NORMAL AND POTENTIALLY HEAVY
PRECIPITATION AFFECTING SOUTHWESTERN CONUS. RELATIVE TO YESTERDAY, THERE IS
INCREASED SUPPORT IN THE MODEL GUIDANCE FOR GULF OF CALIFORNIA SURGE ACTIVITY
ASSOCIATED WITH A TROPICAL DISTURBANCE (INVEST 95E) IN THE EASTERN PACIFIC,
WHERE THE NATIONAL HURRICANE CENTER (NHC) GIVES 80% CHANCES FOR DEVELOPMENT
DURING WEEK-1. THE ADVECTION OF ADDITIONAL TROPOSPHERIC MOISTURE INTO THE
SOUTHWESTERN CONUS IS REFLECTED IN BOTH THE RAW AND CALIBRATED PRECIPITATION
TOOLS, AS BOTH THE GEFS AND ECMWF PETS INDICATE WETTER SIGNALS IN PERCENTILE
SPACE COMPARED TO YESTERDAY. NOTABLY, THE ECMWF IS QUITE BULLISH WITH THIS
POTENTIAL, DEPICTING AT LEAST 60-80% (40-60%) CHANCES FOR 3-DAY AMOUNTS
EXCEEDING THE 85TH PERCENTILE (0.5 INCHES) OVER THE MANY PARTS OF ARIZONA AND
NEW MEXICO. ALTHOUGH THE GEFS IS WEAKER BY COMPARISON (40% CHANCES FOR
EXCEEDING THE 85TH PERCENTILE), THE OVERALL WETTER TREND IN THE TOOLS SUPPORTS
THE ADDITION OF A HIGH RISK OF HEAVY PRECIPITATION IN THE UPDATED OUTLOOK, AND
IS VALID FOR JUL 3 BASED ON HIGHEST TOTALS IN THE ENSEMBLE AND DETERMINISTIC
GUIDANCE. A CORRESPONDING MODERATE RISK AREA REMAINS POSTED WHICH COVERS MORE
OF THE SONORAN DESERT (JUL 3-4), ALONG WITH A BROADER SLIGHT RISK AREA
EXTENDING NORTHWARD INTO THE GREAT BASIN AND ROCKIES WHERE PETS MAINTAIN AT
LEAST A 20% CHANCE FOR 3-DAY AMOUNTS EXCEED THE 85TH PERCENTILE FOR THE
ENTIRETY OF WEEK-2.
DUE TO LOCALLY HEAVY PRECIPITATION RECEIVED OVER PORTIONS OF NEW MEXICO, ANY
ADDITIONAL PRECIPITATION DURING WEEK-2 IS LIKELY TO WORSEN SATURATED GROUND
CONDITIONS AND POSSIBLY TRIGGER ADDITIONAL FLOODING IN THE REGION. A POSSIBLE
HAZARD REMAINS ISSUED AND IS ALSO EXPANDED WESTWARD TO INCLUDE MANY PARTS OF
ARIZONA WHERE LOCALLY HEAVY PRECIPITATION MAY ALSO TRIGGER FLASH FLOODING AND
DEBRIS FLOWS NEAR RECENTLY BURNED AREAS. IN ADDITION TO FLASH FLOODING,
THUNDERSTORM IMPACTS MAY INCLUDE LIGHTNING, GUSTY WINDS AND BLOWING DUST.
HOWEVER, IN SPITE OF THESE POTENTIALLY ADVERSE IMPACTS, SOME AREAS EXPERIENCING
MODERATE TO EXCEPTIONAL DROUGHT CONDITIONS AND WILDFIRES WILL BENEFIT FROM THE
ENHANCED RAINFALL.
DOWNSTREAM OF THE AFOREMENTIONED ANOMALOUS RIDGE CENTER OVER SOUTHWESTERN
CANADA, THE LATEST ENSEMBLE SOLUTIONS HAVE BEGUN TO DIVERGE IN REGARDS TO THE
MID-LEVEL TROUGHING DOWNSTREAM. THE GEFS MAINTAINS MORE SHALLOW TROUGHING,
WHEREAS A MORE AMPLIFIED MEAN TROUGH IN THE ECMWF LOOKS TO SHUNT MUCH OF THE
RIDGING WEST OF THE MISSISSIPPI. IN RESPONSE TO THE STRONGER NORTHWESTERLY FLOW
IN THE ECMWF, COOLER TEMPERATURES AND DRIER CONDITIONS ARE FAVORED OVER
PORTIONS OF THE EASTERN CONUS, KEEPING ANY RENEWED RISK OF EXTREME HEAT AT BAY
OVER THIS PART OF THE COUNTRY THROUGH THE END OF NEXT WEEK. BUT CLOSER TO THE
ANOMALOUS RIDGE CENTER FAVORED UPSTREAM IN BOTH MODELS, ABOVE-NORMAL SUMMERTIME
TEMPERATURES STILL LOOK TO BE A POTENTIAL CONCERN OVER THE NORTHWESTERN CONUS.
THIS IS BEST REFLECTED IN THE GEFS PROBABILISTIC EXTREME TOOLS (PETS), WHICH
INDICATE AT LEAST 20% CHANCES FOR MAXIMUM DAYTIME TEMPERATURES EXCEEDING THE
85TH PERCENTILE FOR THIS PART OF THE COUNTRY. ALTHOUGH THE ECMWF PET IS MUCH
WEAKER IN THE UPDATED GUIDANCE (LIKELY DUE TO INCREASED MOISTURE IN THE
REGION), 20% CHANCES FOR EXTREME HEAT REMAIN POSTED, REMAINING VALID THROUGH
DAY 9 (JUL 4). THE SLIGHT RISK COVERAGE IS NOW LIMITED TO THE NORTHERN
INTERMOUNTAIN AND NORTHERN HIGH PLAINS IN THE UPDATED OUTDATED OUTLOOK DUE TO
THE POTENTIAL FOR COOLER TEMPERATURES IN THE MIDWEST.
IN ADDITION, THERE ARE BETTER INDICATIONS OF STRONGER SUBTROPICAL RIDGING OVER
THE GULF OF AMERICA, WHERE THE COMBINATION OF HIGH DEWPOINTS AND EXCEPTIONALLY
WARM SEA SURFACE TEMPERATURES IN THE GULF (ANOMALIES REGISTERING IN THE UPPER
CLIMATOLOGICAL DECILE) IS EXPECTED TO BRING AN INCREASED RISK OF HEAT INTO
PARTS OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY. BOTH THE GEFS AND
ECMWF PETS HAVE COME INTO BETTER AGREEMENT FAVORING INCREASED HEAT SIGNALS OVER
PARTS OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY. THEREFORE, A SLIGHT
RISK OF EXTREME HEAT IS POSTED WHERE THERE IS A MORE COHERENT COVERAGE OF AT
LEAST 20% CHANCES OF MAXIMUM TEMPERATURES EXCEEDING THE 85TH PERCENTILE AND A
100 DEGREES F (AND 95 DEG F CLOSER TO THE LOWER MISSISSIPPI VALLEY), VALID FOR
JUL 4 TO JUL 7.
ACROSS THE SOUTHEASTERN CONUS, MODELS DEPICT THE PASSAGE OF A FRONTAL BOUNDARY
LATE IN WEEK-1 THAT LOOKS TO POTENTIALLY STALL BY EARLY WEEK-2 AND BECOME A
FOCAL POINT FOR ENHANCED PRECIPITATION. WHILE BOTH RAW AND CALIBRATED TOOLS
SHOW THE HIGHEST AMOUNTS REMAINING OFFSHORE, THERE IS CONTINUED SUPPORT IN THE
PETS FOR 3-DAY AMOUNTS EXCEEDING AN INCH ACROSS PARTS OF THE COASTAL
SOUTHEASTERN U.S THROUGH THE MIDDLE OF WEEK-2, AND A SLIGHT RISK OF HEAVY
PRECIPITATION IS HIGHLIGHTED FROM THE EASTERN GULF COAST TO THE COASTAL
CAROLINAS (JUL 3-5). NOTABLY, THERE ARE A NUMBER OF MEMBERS IN THE ECMWF
ENSEMBLE DEVELOPING A SURFACE LOW AT THE TAIL OF THE FRONT LATER NEXT WEEK.
THIS POTENTIAL LOW COULD GAIN TROPICAL CHARACTERISTICS, THOUGH CHANCES FOR
TROPICAL CYCLOGENESIS HAVE LOWERED IN PROBABILISTIC TOOLS COMPARED TO
YESTERDAY. REGARDLESS, ANY TROPICAL CYCLONE POTENTIAL WILL CONTINUE TO BE
MONITORED.
SURFACE HIGH PRESSURE OVER THE NORTHEASTERN PACIFIC ADJACENT TO MEAN SURFACE
LOW PRESSURE OVER THE INTERIOR WEST MAY LEAD TO TIGHT PRESSURE GRADIENTS ALONG
MUCH OF THE WEST COAST. THIS MAY BE ENHANCED BY THE AFOREMENTIONED HEAT
POTENTIAL FAVORED EARLY IN THE PERIOD, WHICH WOULD LIKELY LOWER SURFACE
PRESSURE. AS A RESULT, A SLIGHT RISK OF HIGH WINDS REMAINS POSTED ALONG MOST OF
THE IMMEDIATE WEST COAST WHERE PETS ALSO INDICATE INCREASED CHANCES FOR WIND
SPEEDS EXCEEDING THE 85TH PERCENTILE.
NUMEROUS WILDFIRES HAVE DEVELOPED ACROSS ALASKA DURING THE PAST FEW DAYS, AND
ROBUST FIRE ACTIVITY IS EXPECTED TO CONTINUE FOR AT LEAST A FEW MORE DAYS. THE
SMOKE GENERATED BY THESE FIRES IS FORECAST TO MEANDER AROUND THE STATE DURING
WEEK-2, FOLLOWING LOW-LEVEL WIND CURRENTS. AS A RESULT, PERIODS OF VERY POOR
AIR QUALITY AND LOW VISIBILITY MAY OCCUR.
FORECASTER: NICK NOVELLA
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