680
FXUS65 KGJT 311134
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
534 AM MDT MON AUG 31 2026
KEY MESSAGES
- SCATTERED TO WIDESPREAD PRECIPITATION CHANCES RETURN MONDAY,
WITH HIGHER COVERAGE OF PRECIPITATION ACROSS SOUTHEAST UT AND
SOUTHWEST CO THAN PREVIOUS DAYS.
- FLASH FLOODING WILL CONTINUE TO BE POSSIBLE AS ORGANIZED AND
TRAINING THUNDERSTORMS CAN PRODUCE HEAVY RAINFALL OVER A SHORT
PERIOD OF TIME.
- AREAS OF CONCERN FOR FLASH FLOODING WILL BE THOSE OF
INCREASINGLY SATURATED SOILS, RECENT BURN SCARS, AND STEEP
TERRAIN.
- SEASONABLE TEMPERATURES RETURN FOR THE FIRST HALF OF THE WEEK.
DISCUSSION
ISSUED AT 934 PM MDT SUN AUG 30 2026
ELEVATED FLASH FLOODING THREAT THROUGH MONDAY EVENING:
A SIGNIFICANT PLUME OF MOISTURE REMAINS IN PLACE THROUGH AT LEAST
MONDAY EVENING FOR MUCH OF THE AREA. PWATS CONTINUE TO HOLD STEADY
AT 160-180% OF NORMAL, WITH LOCALIZED POCKETS OF 200% OF NORMAL.
THIS WILL MEAN ANOTHER DAY OF SCATTERED TO WIDESPREAD SHOWERS AND
STORMS. PRIMARY THREATS CONTINUE TO BE LOCALIZED HEAVY RAINFALL,
LIGHTNING, AND GUSTY OUTFLOW WINDS (35-45 MPH). THIS INHERENTLY
MEANS THERE IS ALSO A RISK FOR FLASH FLOODING AND DEBRIS FLOWS ALONG
RECENT BURN SCARS, SUSCEPTIBLE TERRAIN, AND AREAS OF
INCREASINGLY SATURATED SOILS. AS THE RICHER MOISTURE HOVERS
AROUND THE FOUR CORNERS AREA, THE FLASH FLOODING CONCERN FAVORS
AREAS ALONG AND SOUTH OF I-70 MONDAY. THIS WILL BE ESPECIALLY
TRUE OF AREAS THAT HAVE RECEIVED MULTIPLE ROUNDS OF
PRECIPITATION OVER THE PAST FEW DAYS. FOR THOSE REASONS, A FLOOD
WATCH REMAINS IN EFFECT FOR MUCH OF EASTERN UTAH AND WESTERN
COLORADO THROUGH MONDAY EVENING. SEE THE HYDROLOGY SECTION BELOW
FOR MORE INFORMATION ON THAT.
TUESDAY + BEYOND:
A DRIER AIRMASS MOVES INTO THE AREA BY TUESDAY AND REMAINS IN PLACE
FOR MUCH OF THE WORK WEEK. ALTHOUGH AFTERNOON SHOWERS AND STORMS
REMAIN IN THE FORECAST OVER THE HIGHER TERRAIN, BUT COVERAGE WILL BE
MUCH MORE ISOLATED THAN PREVIOUS DAYS. A RETURN TO SEASONABLE
TEMPERATURES IS ALSO IN THE FORECAST FOR THE FIRST HALF OF THE WEEK.
MODELS CONTINUE TO BE IN AGREEMENT THAT ANOTHER PUSH OF MONSOONAL
MOISTURE IS ON THE HORIZON FOR THE INTERMOUNTAIN WEST THIS COMING
WEEKEND. BUT, THAT PERIOD STILL REMAINS FAR OUT SO THE DETAILS
ARE VAGUE YET. CONTINUE TO MONITOR THE FORECAST AS CHANGES ARE
MADE.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 521 AM MDT MON AUG 31 2026
SHOWERS AND THUNDERSTORMS WILL CONTINUE TODAY WITH HEAVY RAIN,
GUSTY WINDS AND SMALL HAIL ALL BEING A CONCERN. TAF SITES WILL
ALL HAVE CHANCES TO SEE THIS CONVECTION THROUGH THE DAY SO MANY
PROB30 GROUPS ARE IN PLACE TO CAPTURE THIS POSSIBILITY. MAINLY
VFR CONDITIONS WILL REMAIN IN PLACE BUT MVFR, MAYBE BRIEF IFR,
WILL BE POSSIBLE AS STRONGER STORMS AND SHOWERS DROP VIS TO
BELOW 3 MILES. THESE SHOWERS AND STORMS WILL CONTINUE PAST
MIDNIGHT BEFORE DISSIPATING AROUND 09Z.
HYDROLOGY
ISSUED AT 934 PM MDT SUN AUG 30 2026
ANOMALOUS MOISTURE WILL REMAIN LOCKED ACROSS WESTERN
COLORADO AND EASTERN UTAH THROUGH THE EARLY PART OF THE WEEK. THIS
IS MOSTLY DRIVEN BY PWAT VALUES HOLDING AT 160-180% OF NORMAL, WITH
LOCALIZED POCKETS OF 200% OF NORMAL. GIVEN THE ANTECEDENT MOISTURE
FROM RAINFALL OVER PREVIOUS DAYS, SOILS IN SEVERAL SUB-BASINS ARE
ALREADY SATURATED, WHICH COULD PROMOTE AREAS OF RAPID RUNOFF AND
POOR INFILTRATION. A FLOOD WATCH REMAINS IN EFFECT THROUGH MONDAY
EVENING FOR MOST LOCATIONS.
THE MAIN THREATS REMAIN FLASH FLOODING AND DEBRIS FLOWS,
PARTICULARLY OVER RECENT BURN SCARS AND SUSCEPTIBLE TERRAIN.
CRITICAL AREAS OF CONCERN WITHIN THE FLOOD WATCH INCLUDE THE LEE AND
ELK RX, GOLD MOUNTAIN, ELK, FERRIS, AND BABYLON BURN SCARS, WHERE
HYDROPHOBIC SOILS HAVE THE ABILITY TO AMPLIFY PEAK FLOW UNDER
MODERATE RAINFALL RATES.
ALTHOUGH DRIER AIR ATTEMPTS TO NUDGE INTO THE REGION BY TUESDAY,
LINGERING MID-LEVEL MOISTURE AND DAYTIME HEATING WILL KEEP DAILY
AFTERNOON THUNDERSTORMS CHANCES INTACT FOR THE HIGHER TERRAIN
REGIONS. HENCE, A LOCALIZED FLASH FLOODING THREAT WILL REMAIN BEYOND
MONDAY FOR THOSE AREAS.
GJT WATCHES/WARNINGS/ADVISORIES
CO...FLOOD WATCH THROUGH THIS EVENING FOR COZ002-003-006>014-
017>021.
FLOOD WATCH THROUGH THIS EVENING FOR COZ022-023.
UT...FLOOD WATCH THROUGH THIS EVENING FOR UTZ022-025-027>029.
DISCUSSION...BS
AVIATION...TGJT
HYDROLOGY...BS
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