759
FXUS65 KGJT 302045
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
245 PM MDT SUN AUG 30 2026
KEY MESSAGES
- MULTIPLE ROUNDS OF SHOWERS AND STORMS ARE EXPECTED TODAY,
ESPECIALLY ALONG AND NORTH OF I-70.
- ANOTHER WET DAY IS ON TAP TOMORROW AS WELL, WITH HIGHER
COVERAGE OF PRECIPITATION ACROSS SOUTHEAST UTAH AND SOUTHWEST
COLORADO.
- FLASH FLOODING IS POSSIBLE THROUGH MONDAY EVENING AS ORGANIZED
AND TRAINING THUNDERSTORMS PRODUCE HEAVY RAINFALL OVER
INCREASINGLY SATURATED SOILS, RECENT BURN SCARS, AND STEEP
TERRAIN.
DISCUSSION
ISSUED AT 1146 AM MDT SUN AUG 30 2026
ELEVATED FLASH FLOODING THREAT THROUGH MONDAY:
TODAY'S WEATHER PATTERN IS VERY SIMILAR TO YESTERDAY'S WITH AN
UPPER- LEVEL JET DRAPED ALONG AN AXIS FROM SOUTHWEST UTAH TO
CENTRAL WYOMING. LOCALLY, THE JET WILL PROVIDE SYNOPTIC SUPPORT
FOR CONTINUED SHOWERS AND STORMS ALONG AND NORTH OF I-70. THE
NEAR- SURFACE LAYER IS MORE SATURATED TODAY, SO OUTFLOW WINDS
WILL NOT BE AS IMPACTFUL TODAY. STRONGER STORMS WILL BE CAPABLE
OF PRODUCING 35- 45 MPH GUSTS AND FREQUENT LIGHTNING.
WITH WIDESPREAD PRECIPITATION EXPECTED IN THE SAME LOCATIONS AS
YESTERDAY, THE THREAT FOR FLASH FLOODING WILL BE HIGHER TODAY,
ESPECIALLY IN LOCATIONS THAT RECEIVE MULTIPLE ROUNDS OF SHOWERS
AND STORMS. THE SAME CAN BE SAID FOR TOMORROW, WITH FLOODING
BECOMING MORE AND MORE LIKELY AS SOILS AND STREAMS TAKE ON
CONSECUTIVE DAYS OF RAINFALL. TODAY, THE POTENTIAL FOR FLASH
FLOODING WILL BE ALONG AND NORTH OF I-70. TOMORROW, WITH RICHER
MOISTURE MOVING INTO THE FOUR CORNERS REGION, THE THREAT WILL
PRIMARILY BE ALONG AND SOUTH OF I-70. RECENT BURN SCARS ARE
ESPECIALLY SUSCEPTIBLE TO HEAVY RAINFALL WHICH MAY CAUSE DEBRIS
FLOWS AND FLASH FLOODING REGARDLESS OF LOCATION. DUE TO THESE
REASONS, A FLASH FLOOD WATCH IS IN EFFECT FOR MUCH OF EASTERN
UTAH AND WESTERN COLORADO THROUGH MONDAY EVENING. PLEASE SEE THE
HYDROLOGY SECTION BELOW FOR MORE INFORMATION.
LOOKING AHEAD:
A DRIER AIRMASS MOVES IN ON TUESDAY AND REMAINS IN PLACE FOR
MUCH OF THE WORK WEEK. AFTERNOON SHOWERS AND STORMS REMAIN IN
THE FORECAST OVER THE HIGHER TERRAIN, BUT COVERAGE WILL BE MUCH
MORE ISOLATED. OUR FIRST WEEK OF SEASONABLE TEMPERATURES IN
QUITE SOME TIME WILL BE THE HIGHLIGHT OF THE WEEK.
ENSEMBLE GUIDANCE SUPPORTS ANOTHER PUSH OF MONSOONAL MOSITURE
ACROSS THE INTERMOUNTAIN WEST NEXT WEEKEND. MORE DETAILS TO COME
AS THE WEEK PROGRESSES, BUT KEEP AN EYE ON THE FORECAST IF YOU
HAVE OUTDOOR PLANS NEXT WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1146 AM MDT SUN AUG 30 2026
SHOWERS AND ISOLATED/SCATTERED STORMS WILL CONTINUE TO EXPAND
IN AREAL COVERAGE ACROSS WRN CO AND ERN UT TAF SITES THIS
AFTERNOON AND LINGER THROUGH THE EVENING. THOUGH CURRENT TRENDS
SUPPORT THE GREATEST AREAL COVERAGE OF SHOWERS/STORMS TO BE
LOCATED ACROSS NORTHERN TAF SITES INTO EARLY MONDAY. PROB30
GROUPS ARE IN SOME TAF SITES WHERE STORMS ARE EXPECTED, AND
WHERE GUSTY OUTFLOW WINDS AND HEAVY RAIN WILL BE THE MAIN
CONCERNS. MAINLY VFR CONDITIONS WILL REMAIN IN PLACE, WITH MVFR
CIGS AND VSBYS EXPECTED IN STRONGER STORMS AND SHOWERS, WITH
BRIEF IFR VISBILITIES BELOW 3 MILES AT TIMES. CONVECTION WILL
CONTINUE INTO THE OVERNIGHT HOURS THOUGH THE AREAL COVERAGE OF
PRECIPITATION WILL DIMINISH.
HYDROLOGY
ISSUED AT 243 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. A FLOOD WATCH
REMAINS IN EFFECT FROM MONDAY MORNING THROUGH MONDAY EVENING TO
ACCOUNT FOR THESE HYDROLOGIC RISKS FOR MOST OF THE CWA.
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 MONDAY EVENING FOR COZ002-003-006>014-
017>021.
FLOOD WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
COZ022-023.
UT...FLOOD WATCH THROUGH MONDAY EVENING FOR UTZ022-025-027>029.
DISCUSSION...KAA
AVIATION...TGJT
HYDROLOGY...BS
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