363
FXUS65 KGJT 261716
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1116 AM 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 411 AM MDT TUE AUG 26 2025
A WET AND ACTIVE FORECAST CONTINUES TO TAKE SHAPE THIS MORNING.
WATER VAPOR IMAGERY SHOWS WELL STACKED MOISTURE AT ALL LEVELS ACROSS
THE GREAT BASIN, BLEEDING ACROSS THE STATE LINE THIS MORNING.
OVERNIGHT SHOWERS HAVE BEEN PERSISTENT ACROSS EASTERN UTAH AND
WESTERN COLORADO. SOUTHWESTERLY UPSLOPE FLOW HAS PRODUCED SHOWERS
AND THUNDERSTORMS ALL NIGHT ON THE EASTERN TAVAPUTS. SUBSIDENCE
UNDER THE UPPER RIDGE HAS BEEN CURBING INTRUSION INTO THE COLORADO
SIDE OF THE TERRAIN THERE. ALTHOUGH, THAT'S CHANGING AT THE TIME OF
THIS DISCUSSION, WITH A FEW THUNDERSTORMS WORKING ALONG THE RIO
BLANCO/GARFIELD COUNTY BORDER. CONVECTIVE DEBRIS AND CLOUD COVER
LOOK TO LINGER INTO THE MORNING HOURS TODAY, PERHAPS INHIBITING
CONVECTIVE INITIATION. PWAT'S WILL TREND 150-180 PERCENT OF SEASONAL
NORMAL TODAY. AVAILABLE MOISTURE WON'T BE A PROBLEM. A SOUTHWESTERLY
JET STREAK NOSING INTO THE GREAT BASIN WILL CONTINUE TO PUSH
MOISTURE OUR WAY. UPPER LEVEL FORCING AND AFTERNOON HEATING SHOULD
LEND A HAND BY MID DAY. HI RES MODELS ARE DEVELOPING SOME SCATTERED
SHOWERS THIS AFTERNOON, THEN A SERIES OF VORTICITY LOBES RAMPS UP
PRODUCTION THIS EVENING. ALL OF THIS IS EXPECTED TO POSE SOME
CHALLENGES FOR BURN SCARS AND ALREADY SATURATED SOILS. GIVEN THE
ANTECEDENT DRY CONDITIONS AROUND THE REGION, PARCHED DIRT IS
EXPECTED TO MITIGATE IMPACTS OF HEAVY RAIN. HOWEVER, THIS WILL ALL
DEPEND ON VERY LOCALIZED WEATHER PATTERNS TODAY. A FLASH FLOOD WATCH
REMAINS IN EFFECT TODAY AND TONIGHT FOR MUCH OF THE REGION TO
HIGHLIGHT POTENTIAL FOR FLOODING. TEMPERATURES WILL REMAIN ON THE
COOL SIDE OF CLIMATOLOGY TODAY THANKS TO CLOUDS AND RAIN. A FEW
SUNNY LOCALES WILL SURGE UP TOWARDS MORE SUMMER-LIKE CONDITIONS, BUT
THAT WILL BE THE EXCEPTION FOR MUCH OF THE AREA.
SHOWERS WILL TAPER SOME BY EARLY WEDNESDAY MORNING, BUT GIVEN THE
LOCATION OF THE JET OVERHEAD, WE WILL SEE NOCTURNAL SHOWERS
CONTINUE. MUCH OF THIS ACTIVITY WILL LIKELY CONVERT TO STRATIFORM
PRECIPITATION, THEREBY SQUASHING RATES OF ACCUMULATION. HOWEVER,
THERE REMAINS A THREAT FOR LOCALIZED FLOODING TO CONTINUE EARLY
WEDNESDAY, GIVEN THE AMPLE MOISTURE SUPPLY AND POTENTIAL FOR
OVERNIGHT CONVECTION. LEFTOVER CLOUD COVER WILL COME BACK INTO PLAY
WEDNESDAY AGAIN. WHILE PWAT'S TREND DOWNWARD, A GENEROUS SUPPLY OF
SURFACE MOISTURE WILL GET WORKED ON BY OROGRAPHICS. A FEW OF THESE
SHOWERS AND THUNDERSTORMS WILL LIKELY PRODUCE RAIN RATES CAPABLE OF
FLOODING ON BURN SCARS AGAIN. FLOOD CONCERNS WILL BE MUCH MORE
LOCALIZED WEDNESDAY AFTERNOON. TEMPERATURES WILL REMAIN CONSISTENT
AGAIN WEDNESDAY AFTERNOON, WITH THE CHANCE FOR ADDITIONAL SUNSHINE
TO DESTABILIZE US FURTHER.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/
ISSUED AT 343 PM MDT MON AUG 25 2025
A LOW AMPLITUDE UPPER-LEVEL RIDGE CENTERED OVER COLORADO SETS
UP FOR THE LATTER HALF OF THE WEEK. THIS PUTS EASTERN UTAH AND
WESTERN COLORADO IN A SOUTHWESTERLY FLOW PATTERN. A 50-60 KNOT
JET WILL KEEP MOISTURE ELEVATED THROUGH THE EXTENDED FORECAST,
BUT PWAT ANOMALIES BEGIN TO FALL FROM SOUTH TO NORTH ON
WEDNESDAY AS "DRIER" AIR BEGINS TO WORK IN. WITH PWAT ANOMALIES
FALLING FROM 175-200% TO 125-150% OF NORMAL, CONVECTION WILL
BECOME LESS WIDESPREAD AND FAVOR THE HIGHER TERRAIN. WITH THE
REGION ALREADY PRIMED FOR PRECIPITATION, CHANCES ARE HIGHER THAT
AFTERNOON STORMS COULD MOVE OFF THE TERRAIN AND INTO ADJACENT
VALLEYS (TYPICALLY TO THE NORTHEAST). STRONGER STORMS WILL
CONTINUE TO BE CAPABLE OF PRODUCING FREQUENT LIGHTNING AND BURN
SCAR FLASH FLOODING, BUT THE FREQUENCY IN WHICH THIS OCCURS WILL
TREND DOWNWARD INTO THE WEEKEND.
TEMPERATURES REMAIN AT OR BELOW SEASONAL NORMALS THROUGH THE
SEVEN-DAY FORECAST AND WILL BE HIGHLY DEPENDENT ON HOW MUCH
CLOUD COVER THERE IS EACH DAY. IN GENERAL, WE'LL SEE A DECREASE
IN CLOUD COVER HEADING INTO THE WEEKEND SO TEMPERATURES WILL
WARM A HANDFUL OF DEGREES IN RETURN.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1115 AM MDT TUE AUG 26 2025
SHOWERS WILL LIKELY PRODUCE INTERMITTENTBREAKPOINT CONDITIONS
FOR THE TERMINALS WITH LOW CEILINGS AND VISIBILITY. GUSTY
OUTFLOW WINDS AND SMALL HAIL WILL REMAIN A CONCERN FOR AVIATORS
TOO. WINDS WILL REMAIN LIGHT AND TERRAIN DRIVEN OTHERWISE. SOME
SHOWER ACTIVITY IS EXPECTED TO CONTINUE INTO TOMORROW MORNING.
HYDROLOGY
ISSUED AT 411 AM MDT TUE AUG 26 2025
FLASH FLOODING AND DEBRIS FLOWS ADJACENT TO BURN SCARS
CONTINUES TO BE A PROMINENT CONCERN AS ANOMALOUSLY HIGH MOISTURE
MAKES ITS WAY THROUGH THE REGION. NON-BURN SCAR RELATED MUD AND
ROCK SLIDES HAVE ALSO BEEN OBSERVED OVER THE PAST COUPLE DAYS
AS A RESULT OF THE MULTIPLE DAYS OF RAINFALL. PWAT'S SURGE
HIGHER TODAY. AS A RESULT, A FLASH FLOOD WATCH HAS BEEN ISSUED
FOR SOUTHEASTERN UTAH AND MUCH OF WESTERN COLORADO. FLASH
FLOODING WILL BECOME MORE LOCALIZED WEDNESDAY, BUT REMAIN A
THREAT DUE TO POTENTIAL FOR HEAVY RAINFALL.
GJT WATCHES/WARNINGS/ADVISORIES
CO...FLOOD WATCH THROUGH THIS EVENING FOR COZ003-006>014-017>023.
UT...FLOOD WATCH THROUGH THIS EVENING FOR UTZ022-028-029.
SHORT TERM...LTB
LONG TERM...KAA
AVIATION...TGJT
HYDROLOGY...TGJT
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