893
FXUS65 KGJT 262353
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
553 PM MDT TUE AUG 26 2025
KEY MESSAGES
- WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE
TODAY AND BEYOND.
- ELEVATED RISK TODAY FOR FLASH FLOODING AND DEBRIS FLOWS IN
SENSITIVE AREAS, ESPECIALLY OVER RECENT BURN SCARS.
- HEAVY RAIN BECOMES MORE LOCALIZED WEDNESDAY AND FLASH FLOODING
REMAINS A CONCERN, ESPECIALLY FOR RECENT BURN SCARS.
- TEMPERATURES WILL TREND COOLER THIS WEEK THANKS TO RAIN AND
CLOUD COVER.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 253 PM MDT TUE AUG 26 2025
CLOUD COVER FAILED TO CLEAR OUT MUCH THIS MORNING WITH MOST SKIES
AROUND THE CWA OVERCAST FOLLOWING SUNRISE. WE GOT A LATE JUMP
ON THE DIURNAL HEATING WITH THIS, BUT AS SKIES HAVE CLEARED
BEHIND THE MORNING CLOUDS, CAPE IS BACK ON THE RISE, SURPASSING
500 J/KG IN THE 18Z GRAND JUNCTION SOUNDING. THE MOISTURE IS
HERE TOO, WITH A SOUNDING PWAT OF 1.3 INCHES, NEARLY A RECORD
VALUE. ADD TO THIS THAT BITS OF ENERGY PASSING THROUGH THE
REGION ARE PRESENT IN DETERMINISTIC MODELS AND IT IS EVIDENT
THAT WE ARE ON OUR WAY TOWARDS AN ACTIVE AFTERNOON IN SPITE OF
THE STUBBORN MORNING CLOUDS. WITH THE STRATIFORM PRECIPITATION
WHICH WAS MOVING THROUGH OUR CENTRAL CWA THIS MORNING LINGERING
OVER NORTHWESTERN COLORADO NOW, ANY REMAINING STORMS IN THIS
REGION THROUGH THE DAY SHOULD STAY ON THE MILDER SIDE, OFFERING
MOSTLY LIGHT AND STEADY RAINFALL. IT'S A DIFFERENT STORY ALONG
AND SOUTH OF I-70 WHERE MESOANALYSIS IS TRENDING TOWARDS A STARK
SPIKE IN CAPE TO OVER 1500 J/KG OVER MUCH OF SOUTHEASTERN UTAH
(AND OVER 1000 J/KG FOR MUCH OF SOUTHWESTERN COLORADO). WITH THE
ENVIRONMENT LOOKING TO ONLY GET MORE UNSTABLE FROM HERE, WE
COULD SEE SOME STRONG, DISCRETE CELLS CAPABLE OF PRODUCING
STRONG OUTFLOW WINDS, HAIL UP TO AN INCH IN SIZE, AND FLASH
FLOODING CONCERNS, ESPECIALLY OVER PRONE AREAS AND BURN SCARS.
SOME OF THESE FLASH FLOODING CONCERNS HAVE ALREADY BECOME
EVIDENT ON THE UTAH SIDE OF THE FOUR CORNERS, SO IT IS IMPORTANT
TO STAY AWARE OF ONGOING WEATHER AS IT DEVELOPS THROUGH THE
AFTERNOON.
THE PLUME OF MOISTURE BEGINS TO GET PULLED NORTHWARDS TOMORROW
WITH A DEEP RIDGE BUILDING THROUGH WYOMING, MONTANA, AND INTO
CANADA. WE WON'T DRY OUT TOO QUICKLY AS PWAT'S SHOULD STAY WELL
ABOVE NORMAL (>150% OF NORMAL), BUT THIS WILL MARK THE START OF
A DECREASE IN ACTIVITY THROUGHOUT THE REMAINDER OF THE WEEK.
HIGH TEMPERATURES WILL BE 5-10 DEGREES BELOW NORMAL TOMORROW AS
WELL.
LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/
ISSUED AT 253 PM MDT TUE AUG 26 2025
ON THURSDAY THE FORECAST AREA WILL STILL BE SITUATED ON THE NORTHERN
PERIPHERY OF THE HIGH PRESSURE RIDGE. THERE WILL STILL BE ENOUGH
MOISTURE FOR SCATTERED SHOWERS, BUT NOT LIKE WHAT WE ARE SEEING
TODAY. THE MODELS ARE FAVORING THE NORTHERN TWO THIRDS OF AREA,
WHICH IS WHERE THE INSTABILITY WILL BE. ON SATURDAY THERE ARE HINTS
OF A WEAK SHORTWAVE MOVING UP FROM THE NORTHERN BAJA. WHETHER THIS
WAVE ENHANCES OR INHIBITS CONVECTION WILL COME DOWN TO TIMING. THE
EXACT TRACK IS UNKNOWN BUT IT APPEARS IT COULD BISECT THE CWA RIGHT
DOWN THROUGH THE CENTER FROM WEST TO EAST. BEHIND THAT WAVE IT LOOKS
LIKE A MODEST PUSH OF DRIER AIR COMES IN FROM THE NORTHWEST ON
SUNDAY. THIS COULD END THE MONSOON PUSH OR PERHAPS RESULT IN MORE
ISOLATED CONVECTION. THIS IS ALSO WHEN THE TEMPERATURES WILL RISE
TO NEAR NORMAL OR SLIGHTLY ABOVE AVERAGE.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 542 PM MDT TUE AUG 26 2025
SHOWERS AND THUNDERSTORMS ARE ONGOING ACROSS THE REGION. THE
STRONGEST STORMS ARE CURRENTLY OCCURRING SOUTH OF I-70, BUT
CHANCES OF PRECIPITATION PERSIST THROUGH THE NIGHT FOR MOST TAF
SITES. THE PRIMARY CONCERNS WITH THE CONVECTIVE ACTIVITY WILL
CONTINUE TO BE REDUCED VISIBILITIES FROM HEAVY RAIN AND LOWER
CEILINGS. THIS MAY CAUSE A BRIEF DROP TO MVFR CONDITIONS AND
ILS BREAKPOINTS TO BE MET. SMALL HAIL AND GUSTS TO AROUND 20
KTS ARE ALSO POSSIBLE WITH STORMS.
HYDROLOGY
ISSUED AT 253 PM MDT TUE AUG 26 2025
CONVECTIVE-TYPE STORMS HAVE BEGUN TO DEVELOP OVER SOUTHEASTERN
UTAH, BRINGING HEAVY RAIN TO LOCALIZED AND FLASH FLOOD PRONE
AREAS. THIS COULD BE THE STORY FOR MUCH OF OUR SOUTHERN CWA
THROUGHOUT THE AFTERNOON, INCLUDING FOR MANY OF OUR BURN SCARS
WHERE DEBRIS FLOWS COULD BECOME A CONCERN WITH HIGH RAINFALL
RATES. WE REMAIN IN A FLASH FLOOD WATCH AS A RESULT. MOISTURE
BEGINS TO RETREAT TO THE NORTH TOMORROW, BUT PRECIPITATION
POTENTIAL REMAINS FAIRLY HIGH. ISOLATED TO SCATTERED STORMS WILL
POSE ANOTHER THREAT FOR FLASH FLOODING OVER LOCALIZED AREAS.
GJT WATCHES/WARNINGS/ADVISORIES
CO...FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ003-006>014-
017>023.
UT...FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR UTZ022-028-029.
SHORT TERM...BW
LONG TERM...KJS
AVIATION...TGJT
HYDROLOGY...TGJT
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