279
FXUS65 KGJT 010430
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1030 PM MDT MON AUG 31 2026
KEY MESSAGES
- DRIER AIR BEGINS TO MOVE IN TODAY, LIMITING CHANCES FOR
SHOWERS AND THUNDERSTORMS TO THE HIGHER TERRAIN THIS
AFTERNOON.
- DEEP SURFACE MOISTURE WILL KEEP CHANCES FOR HEAVY RAIN IN THE
FORECAST, ALONG WITH THE POTENTIAL FOR FLASH FLOODING AND
DEBRIS FLOWS OVER RECENT BURN SCARS AND OTHER VULNERABLE
AREAS.
- TEMPERATURES WILL WARM THROUGH THE END OF THE WEEK, REACHING
NEAR- NORMAL BY FRIDAY.
DISCUSSION
ISSUED AT 1027 PM MDT MON AUG 31 2026
TROUGHING ALONG THE WEST COAST AND RIDGING ACROSS THE SOUTHEAST WILL
KEEP EASTERN UTAH AND WESTERN COLORADO UNDER SOUTHWESTERLY FLOW
THROUGH THE END OF THE WORK WEEK. THIS WILL PULL IN DRIER AIR,
GRADUALLY REDUCING PRECIPITATION CHANCES THROUGH THE END OF THE WEEK
AS SURFACE LEVEL MOISTURE IS SCOURED OUT. THAT SAID, CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL REMAIN EACH AFTERNOON, PRIMARILY
ACROSS THE HIGHER TERRAIN. ENOUGH SURFACE MOISTURE IS EXPECTED TO
STICK AROUND TUESDAY TO KEEP THE POTENTIAL FOR HEAVY RAIN AROUND, AS
WELL THE POTENTIAL FOR FLASH FLOODING IN VULNERABLE LOCATIONS. AS
DRIER AIR CONTINUES TO PUSH IN, THE MAIN THREAT WITH STORMS WILL
TRANSITION TO THAT OF GUSTY OUTFLOW WINDS. LIGHTNING WILL BE A
THREAT THROUGHOUT THE PERIOD WITH ANY STORM. TEMPERATURES WILL WARM
DAY BY DAY AS WE DRY OUT, REACHING NEAR-NORMAL VALUES BY THE END OF
THE WORK-WEEK.
A STRONG CLOSED LOW IS FORECAST TO DROP OUT OF THE GULF OF ALASKA BY
THE WEEKEND, FORCING THE WEST COAST TROUGH TO RETROGRADE SLIGHTLY.
THIS WILL ALLOW THE SOUTHEAST RIDGE TO ALSO EXPAND WESTWARD, AND
ULTIMATELY THE FLOW OVER EASTERN UTAH AND WESTERN COLORADO WILL
SHIFT TO A MORE SOUTHERLY DIRECTION. THIS WILL ONCE AGAIN TAP INTO
DEEPER MONSOONAL MOISTURE, BRINGING A RETURN TO WETTER AND COOLER
CONDITIONS. ENSEMBLE AND DETERMINISTIC GUIDANCE DOES REMAIN IN
DECENT AGREEMENT REGARDING A PLUME OF ABOVE NORMAL PWATS REACHING
EASTERN UTAH AND WESTERN COLORADO BY SATURDAY, BUT THERE DOES REMAIN
SOME UNCERTAINTY. CHANGES WITH THE TROPICAL SYSTEM ACTIVITY IN THE
PACIFIC COULD SUBSTANTIALLY ALTER THIS FORECAST, SO BE SURE TO STAY
TUNED FOR UPDATES ON HOW THIS WEEKEND'S FORECAST DEVELOPS.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 551 PM MDT MON AUG 31 2026
ISOLATED TO SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
ARE MOVING TO THE NORTHEAST MOSTLY NORTH OF I-70 WILL MOVE OUT
OF THE REGION OVER THE NEXT FOUR HOURS. ANOTHER BAND OF
SCATTERED SHOWERS WITH ISOLATED THUNDERSTORM ARE MOVING INTO THE
REGION FROM THE SOUTHWEST AND SHOULD TRANSIT THE REGION THROUGH
ABOUT 09Z, EXITING TO THE NORTHEAST. PRIMARY THREATS ARE HEAVY
RAIN WITH BRIEF PERIODS OF MVFR TO IFR CONDITIONS BELOW ILS
BREAKPOINTS, LIGHTNING AND GUSTS TO 25KTS. OTHERWISE, EXPECT
CLOUDY SKIES OVERNIGHT BECOMING SCATTERED TO CLEAR AFTER 12Z AND
LIGHT WINDS ACROSS THE REGION. ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL DEVELOP AFTER 18Z OVER THE HIGHER TERRAIN.
HYDROLOGY
ISSUED AT 1027 PM MDT MON AUG 31 2026
ALTHOUGH DRIER AIR BEGINS TO MOVE INTO THE REGION, LINGERING MID-
LEVEL MOISTURE AND DAYTIME HEATING WILL KEEP AFTERNOON THUNDERSTORMS
IN THE FORECAST FOR THE HIGHER TERRAIN REGIONS TUESDAY. HENCE, A
LOCALIZED FLASH FLOODING THREAT REMAINS. RECENT BURN SCARS AND OTHER
VULNERABLE TERRAIN, INCLUDING SLOT CANYONS, CONTINUE TO BE MOST
SUSCEPTIBLE.
GJT WATCHES/WARNINGS/ADVISORIES
CO...NONE.
UT...NONE.
DISCUSSION...BGB/TGJT
AVIATION...TGJT
HYDROLOGY...TGJT
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page