628
FXUS21 KWNC 091817
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JULY 09 2025
SYNOPSIS: MID-LEVEL HIGH PRESSURE IS PREDICTED OVER THE WESTERN CONTIGUOUS U.S.
(CONUS) FAVORING AN INCREASED RISK OF EXTREME HEAT OVER MUCH OF THE INTERIOR
NORTHWEST DURING THE FIRST TWO DAYS OF WEEK-2. OVER THE SOUTHERN HIGH PLAINS
AND SOUTHERN ROCKIES, A FAIRLY STRONG COLD FRONT FOR THIS TIME OF YEAR IS
EXPECTED TO RUN INTO PLENTY OF MOISTURE ACROSS WEST TEXAS AND NEW MEXICO DURING
THE FIRST HALF OF THE FORECAST PERIOD. THEREAFTER, SHOWER AND THUNDERSTORM
ACTIVITY ASSOCIATED WITH THE MONSOON IS EXPECTED TO INCREASE IN COVERAGE ACROSS
ARIZONA. A DECAYING FRONT OVER THE SOUTHEAST IS FORECAST TO BRING SIGNIFICANT
PRECIPITATION TO THE SOUTHEAST AND GULF COASTS.
HAZARDS
SLIGHT RISK OF EXTREME HEAT FOR THE INTERIOR NORTHWEST, THU-FRI, JUL 17-18.
SLIGHT RISK OF HEAVY PRECIPITATION OVER NEW MEXICO AND WESTERN TEXAS, THU-SAT,
JUL 17-19.
SLIGHT RISK OF HEAVY PRECIPITATION OVER ARIZONA, SAT-WED, JUL 19-23.
SLIGHT RISK OF HEAVY PRECIPITATION OVER THE SOUTHEAST AND GULF COASTS, THU-SUN,
JUL 17-20.
DETAILED SUMMARY
FOR SATURDAY JULY 12 - WEDNESDAY JULY 16:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY JULY 17 - WEDNESDAY JULY 23: A MID-LEVEL RIDGE ACCOMPANIED BY
MAXIMUM MID-TROPOSPHERIC HEIGHTS NEAR 594 DM AND SMALL POSITIVE HEIGHT
DEPARTURES (+30 METERS) ARE FORECAST ACROSS THE WESTERN CONUS EARLY IN WEEK-2
BY THE GEFS, ECENS AND CMCE ENSEMBLE MODELS. A SLIGHT RISK OF EXTREME HEAT IS
POSTED FOR MUCH OF THE INTERIOR NORTHWEST, JULY 17-18. ACTUAL AIR TEMPERATURES
ARE PREDICTED TO RANGE FROM THE MID-UPPER 90’S FOR MOST OF THIS AREA TO NEAR
110 DEG F IN THE WESTERN PART OF THE SNAKE RIVER VALLEY AND SOUTH-CENTRAL
WASHINGTON, AS SUPPORTED BY THE DETERMINISTIC 0Z ECMWF AND 6Z GFS MODEL RUNS.
THE AREA OF EXTREME HEAT THAT WAS HIGHLIGHTED THE PAST TWO DAYS ACROSS THE
NORTHEAST IS PREDICTED TO BE JUST PAST ITS PEAK, FOLLOWED BY A SLOW BUT GRADUAL
REDUCTION IN TEMPERATURES AND HUMIDITY INTO MORE SEASONABLE SUMMER CONDITIONS.
OVER THE SOUTHERN HIGH PLAINS, A FAIRLY STRONG COLD FRONT FOR THIS TIME OF YEAR
IS PREDICTED TO RUN INTO SIGNIFICANT MOISTURE ACROSS WESTERN TEXAS AND NEW
MEXICO. THE UPSLOPE IN THIS REGION, ACCOMPANIED BY CLOUDINESS AND HEAVY
PRECIPITATION, IS EXPECTED TO REDUCE TEMPERATURES VERY LATE IN WEEK-1 AND INTO
EARLY WEEK-2. IN LIGHT OF RECENT NEWS EVENTS, IT IS HIGHLY RECOMMENDED THAT
RESIDENTS LIVING IN AREAS OF RECENT WILDFIRE ACTIVITY AND RESULTING BURN SCARS
BE VIGILANT OF THE POTENTIAL FOR FLASH FLOODING AND MUDFLOWS. RAINFALL AMOUNTS
OF 0.75-INCH TO 1.5 INCHES ARE GENERALLY EXPECTED WITHIN THIS REGION, SUPPORTED
BY THE UNCALIBRATED ECENS PRECIPITATION GUIDANCE AND THE ECENS PRECIPITATION
PROBABILISTIC EXTREMES TOOL (PET). AMOUNTS FORECAST BY THE GEFS ARE
SUBSTANTIALLY LESS BY COMPARISON. AS A RESULT, A SLIGHT RISK OF HEAVY
PRECIPITATION IS FAVORED FOR THIS AREA FROM JULY 17-19. AS THE CENTER OF THE
SUBTROPICAL RIDGE SHIFTS TOWARDS THE FOUR CORNERS AREA LATER IN WEEK-2, MONSOON
ACTIVITY IS PREDICTED TO RAMP UP ACROSS ARIZONA. THE PETS PREDICT 0.50 TO
0.75-INCH OF RAIN TO FALL IN ARIZONA DURING THIS TIME, WHICH HAS THE POTENTIAL
TO TRIGGER FLASH FLOODING IN AREAS OF RECENT WILDFIRE ACTIVITY AND ASSOCIATED
BURN SCARS, AS WELL AS SLOT CANYONS AND OTHER AREAS ESPECIALLY PRONE TO FLASH
FLOODING. A SLIGHT RISK OF HEAVY PRECIPITATION IS THEREFORE POSTED FOR MUCH OF
SOUTHERN AND WESTERN ARIZONA, JULY 19-23. GIVEN THE CONTINUED UNCERTAINTY, AND
GIVEN A SOMEWHAT WEAKER OVERALL PRECIPITATION SIGNAL IN THE TOOLS OVER ARIZONA,
NO MODERATE RISK WAS ASSIGNED TO THIS AREA TODAY.
IN THE SOUTHEAST A SLIGHT RISK OF HEAVY PRECIPITATION IS POSTED FOR JULY 17-20,
WHERE A DECAYING BAROCLINIC ZONE MAY BRING 1.0-1.5 INCHES OF PRECIPITATION TO
THE SOUTHEAST AND GULF COASTS FROM ABOUT THE TIDEWATER AREA OF SOUTHEASTERN
VIRGINIA TO WESTERN LOUISIANA. IN ADDITION, AN AREA OF SURFACE LOW PRESSURE IS
FORECAST TO MOVE WESTWARD NEAR OR JUST OFF THE SOUTHEAST/GULF COAST REGION, AND
THIS LOW WILL BE MONITORED FOR POSSIBLE FUTURE TROPICAL DEVELOPMENT. AS OF
TODAY, JULY 9, THE NATIONAL HURRICANE CENTER DOES NOT EXPECT TROPICAL
DEVELOPMENT OVER THE GULF FOR THE NEXT 7-DAYS.
FORECASTER: ANTHONY ARTUSA
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