203
FXUS65 KGJT 140415
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1015 PM MDT SUN SEP 13 2026
KEY MESSAGES
- THERE IS A CHANCE FOR STRONG STORMS OVER THE NEXT FEW DAYS,
CAPABLE OF PRODUCING HAIL, GUSTY WINDS, AND HEAVY RAINFALL.
- MODERATE TO HEAVY RAINFALL COULD LEAD TO LOCALIZED FLASH
FLOODING, ROCKFALLS, AND MUDSLIDES AT TIMES THIS WEEK.
- TEMPERATURES RETURN TO NEAR-NORMAL THROUGH THE WEEK.
DISCUSSION
ISSUED AT 1015 PM MDT SUN SEP 13 2026
FLASH FLOODING POSSIBLE MONDAY:
WE'RE STILL SEEING ISOLATED CONVECTION ONGOING ACROSS THE
REGION EARLY TONIGHT, AND CAM'S ARE IN UNISON INDICATING
STRATIFORM-TYPE RAINFALL DEVELOPING ACROSS PORTIONS OF THE CWA
THROUGHOUT THE REMAINDER OF THE NIGHT. SOME OF THIS, AS SEEN IN
NORTHEASTERN UTAH AND CREEPING INTO NORTHWESTERN COLORADO, IS
BEING DRIVEN BY A COLD FRONT. WITHOUT DAYTIME HEATING TO FURTHER
SUPPORT THE ACTIVE WEATHER, NIGHTTIME IMPACTS SHOULD BE
MINIMAL, BUT DON'T BE SURPRISED IF WE GET A STRONGER CELL OR TWO
OVER THE NEXT FEW HOURS. OTHERWISE, THE FRONT LOOKS TO COOL THE
AREA BACK TO NEAR-NORMAL FOR THE NEXT WEEK.
THESE OVERNIGHT STORMS AND COOLING ASSOCIATED WITH THE PASSING
COLD FRONT MAY MARGINALLY STABILIZE THE ATMOSPHERE. TO ADD TO
THE STABILIZATION, CAM'S ARE IN GOOD AGREEMENT ABOUT BROKEN
CLOUD COVER WITHIN THE SOUTHEAST QUADRANT OF THE CWA MONDAY
MORNING. HOWEVER, SOME GUIDANCE'S CLOUD COVER LOOKS MARGINALLY
LESS DENSE THAN IT HAS OVER THE PAST COUPLE DAYS, AND THE
NORTHWESTERN HALF OF THE CWA IS STILL ON TRACK TO SEE RELATIVELY
CLEAR SKIES IN THE MORNING. PLUS, WE ARE STILL SLATED TO SIT
UNDERNEATH A FAVORABLE REGION OF THE UPPER-LEVEL JET STREAK. SO,
WHILE IT MAY BE STRUGGLE FOR SOME AREAS TO GARNER SIGNIFICANT
INSTABILITY, THERE IS EVIDENCE THAT THERE WILL BE A HANDFUL OF
POWERFUL STORMS CAPABLE OF LOCALIZED HEAVY RAINFALL, GUSTY
WINDS, AND SOME HAIL. MOST HAIL WILL BE SUB-SEVERE, BUT WE'VE
SEEN A COUPLE SUPERCELLS CAPABLE OF LARGE HAIL OVER THE PAST 48
HOURS, SO DON'T RULE OUT A SEVERE STORM OR TWO.
CAM'S ARE HINTING AT THE BEST AREA FOR STRONG STORM DEVELOPMENT
TO COME ON THE EDGE OF THE DENSEST CLOUD COVER WHERE
DESTABILIZATION WILL BE EASIER TO ACHIEVE AND MOISTURE WILL BE
POTENT. THIS CORRIDOR LOOKS TO SPAN FROM SOUTHEASTERN UTAH
TOWARDS THE GRAND MESA, THOUGH THE EXACT LOCATION WILL VARY
DEPENDING ON SAID MORNING CLOUD COVER. AS THE EVENT UNFOLDS
MONDAY AND ACTIVE WEATHER TRANSITS EASTWARDS, THE EXPECTATION IS
FOR STORMS TO STRATIFORM OUT GIVEN THE LIKELY MORE STABLE
ENVIRONMENT OVER THE SAN JUANS AND CENTRAL COLORADO MOUNTAINS.
EVEN SO, EMBEDDED STRONGER CELLS WILL BE POSSIBLE. FOR THOSE
STRONGER CELLS, LOCALIZED HEAVY RAINFALL WILL RAISE CONCERNS OF
FLASH FLOODING, ESPECIALLY OVER VULNERABLE AREAS AND BURN SCARS.
IN THE SCENARIO THAT STORMS STRUGGLE TO ORGANIZE OR CLOUD COVER
SPANS A GREATER AREA THAN ANTICIPATED, STRATIFORM RAINFALL WILL
BE FAVORED REGION-WIDE. AS MENTIONED BEFORE, EMBEDDED STRONGER
CELLS COULD AND LIKELY WILL STILL DEVELOP, WHICH MEANS A FLASH
FLOODING THREAT WILL EXIST REGARDLESS OF STORM MODE. AS ALWAYS,
BE WEATHER AWARE MONDAY (AND BEYOND) AND STAY UP-TO-DATE WITH
ADDITIONAL INFORMATION AS IT BECOMES AVAILABLE.
ACTIVE WEATHER EXPECTED THROUGH THE END OF THE WEEK:
THE CWA REMAINS IN SOUTHWEST FLOW ALOFT AS THE FIRST LOW TRACKS
OVER THE MIDWEST AND ANOTHER LOW DROPS INTO THE PACNW. THIS
WILL ULTIMATELY KEEP MOISTURE IN PLACE THROUGH AT LEAST THE MID-
WEEK, SO EXPECT THE CHANCES FOR SHOWERS AND STORMS TO CONTINUE.
ON WEDNESDAY THE MODELS ARE HINTING THAT A SUBTLE SHORTWAVE
MOVES IN FROM THE SOUTHWEST. IF THIS WERE TO HAPPEN IT WOULD
CERTAINLY BE A FOCUS FOR SHOWERS AND STORMS ESPECIALLY GIVEN THE
PERSISTENT MOISTURE POOL. ON FRIDAY, MOISTURE BEGINS TO
DIMINISH AS THE LOW MOVES EASTWARDS THROUGH THE WESTERN US.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 610 PM MDT SUN SEP 13 2026
ISOLATED TO SCATTERED STORMS WILL CONTINUE THIS EVENING,
BECOMING MORE WIDESPREAD DURING THE OVERNIGHT PERIOD. LOCALIZED
HEAVY RAINFALL IMPACTING VISIBILITY ALONG WITH LIGHTNING AND
GUSTY OUTFLOWS WILL BE THE PRIMARY THREATS FOR AVIATORS. MVFR
CONDITIONS MAY BE POSSIBLE WHERE VISIBILITIES DETERIORATE. WINDS
WILL REMAIN BREEZY WITH GUSTS 25 TO 35 MPH THIS EVENING, AND
SOME LOCATIONS HOLDING ON TO THE HIGHER SPEEDS WELL INTO THE
OVERNIGHT PERIOD. PRECIPITATION CHANCES WILL CONTINUE TO BE
AROUND FOR MUCH OF THE DAY ON MONDAY AS WELL SO INCLUDED PROB30
GROUPS FOR MONDAY AFTERNOON.
GJT WATCHES/WARNINGS/ADVISORIES
CO...NONE.
UT...NONE.
DISCUSSION...BW/TGJT
AVIATION...TGJT
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