580
FXUS65 KGJT 130632
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1232 AM MDT SAT SEP 13 2025
KEY MESSAGES
- SCATTERED SHOWERS AND STORMS ARE EXPECTED TOMORROW MAINLY
DURING THE AFTERNOON. A FEW STORMS MAY BE CAPABLE OF
PRODUCING STRONG WINDS, HAIL AND HEAVY RAINFALL.
- CONDITIONS DRY OUT ON SUNDAY SO EXPECT LESS ACTIVE WEATHER
WITH BELOW NORMAL TEMPERATURES.
UPDATE
ISSUED AT 1219 AM MDT SAT SEP 13 2025
LET THE FLOOD WATCH EXPIRE AT MIDNIGHT. EVEN THOUGH STORMS ARE
EXPECTED AGAIN ON SATURDAY WITH POTENTIAL FOR BRIEF HEAVY RAIN,
COVERAGE LOOKS TO BE MORE SCATTERED AND DEEPER MOISTURE STARTS
TO DECREASE AS ITS PUSHED EASTWARD. LOCALIZED FLASH FLOODING IS
STILL POSSIBLE ESPECIALLY OVER RECENT BURN SCARS AND AREAS OF
ALREADY SATURATED SOILS BUT THE FLOODING THREAT IS NOT EXPECTED
TO BE AS WIDESPREAD AS THE PREVIOUS TWO DAYS.
SHORT TERM /THROUGH SUNDAY/
ISSUED AT 334 PM MDT FRI SEP 12 2025
OVERALL THIS EVENING WE SHOULD SEE A WEAKENING TREND TO THE
CONVECTION ALTHOUGH THERE WILL STILL BE SHOWERS AND STORMS. BY
MIDNIGHT IT BECOMES MORE ISOLATED TO SCATTERED. LATE TONIGHT THE
SHORTWAVE TROUGH SWINGS OVER UTAH. OVERALL THIS EVENING WE
SHOULD SEE A WEAKENING TREND TO THE CONVECTION ALTHOUGH THERE
WILL STILL BE SHOWERS AND STORMS. BY MIDNIGHT IT BECOMES MORE
ISOLATED TO SCATTERED. LATE TONIGHT THE SHORTWAVE TROUGH SWINGS
OVER UTAH AND LOOKS TO PUSH ANOTHER ROUND OF MOISTURE ADVECTION
INTO SOUTHWEST COLORADO. SO WE COULD SEE AN INCREASE IN SHOWER
THERE AS EVIDENT ON THE LATEST HI-RES MODELS. DURING THE MORNING
HOURS THE WAVE LIFTS OVER NORTHEAST UTAH AND NORTHWEST
COLORADO. MOISTURE DOES DECREASE AS THE DEEPER PLUME PUSHES EAST
OF THE DIVIDE. ALTHOUGH THE LAPSE RATES DO STEEPEN, WHICH
SHOULD ALLOW FOR MODEST INSTABILITY ONCE AGAIN. THE WAVE ITSELF
SHOULD PROVIDE LIFT AS WELL SO EXPECT ANOTHER ROUND OF SHOWERS
AND STORMS WITH THE BETTER CHANCES ACROSS THE NORTH. THE MODELS
ALSO SHOW THAT THE JET ALOFT MAY STILL BE OVERHEAD, WHICH WILL
CONTRIBUTE TO THE SHEAR. WITH ALL OF THAT BEING SAID STRONG TO
SEVERE STORMS LOOK POSSIBLE ACROSS A GOOD PORTION OF THE AREA
LATE TOMORROW MORNING AND INTO THE EARLY EVENING. GUSTY WINDS
AND LARGE HAIL WILL BE THE MAIN IMPACTS, BUT HEAVY RAINFALL CAN
NOT BE RULED OUT.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/
ISSUED AT 334 PM MDT FRI SEP 12 2025
ON SUNDAY MORNING THE AXIS OF A TROUGH MOVING ACROSS THE REGION
WILL BE EAST OF THE ROCKIES. HIGH PRESSURE WILL BRIEFLY BUILD
BEHIND THE TROUGH. THIS PATTERN SHIFT WILL LEAD TO A DRIER
AIRMASS MOVING OVER THE REGION, ENDING THE ONGOING RETURN OF THE
MONSOON. BY MONDAY NIGHT A TROUGH OFF THE PACIFIC NORTHWEST
WILL BE PASSING TO OUR NORTH. AS IT PASSES, IT MAY PROVIDE JUST
ENOUGH SUPPORT TO INCREASE POPS ALONG OUR NORTHERN BORDER
TUESDAY NIGHT, AND TO ALLOW FOR AFTERNOON CONVECTION ON TUESDAY
AND WEDNESDAY OVER THE HIGHER TERRAIN. ALTHOUGH, MODELS SEEM TO
DISAGREE ON BOTH THE TIMING OF THIS THROUGH PASSAGE, AND HOW FAR
SOUTH THE TROUGH WILL DIG. IN ADDITION, MOISTURE LOOKS TO BE
PRETTY LIMITED DURING THIS PERIOD SO NOT MUCH IS EXPECTED IN
TERMS OF QPF. HIGH PRESSURE BUILDS AGAIN AFTER THIS TROUGH
PASSAGE. WITH THE DECREASE IN MOISTURE, AND PERIODS OF
INCREASING HIGH PRESSURE, SEASONABLE TEMPERATURES RETURN
THROUGH THE WORKWEEK.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1219 AM MDT SAT SEP 13 2025
ISOLATED THUNDERSTORMS ARE EXPECTED TO CONTINUE THIS MORNING
WITH SOME DEVELOPMENT POSSIBLE ACROSS THE AREA AFTER 12Z.
CHANCES ARE HIGHER FOR STORM DEVELOPMENT LATE THIS MORNING INTO
THE AFTERNOON WITH STORMS LASTING THROUGH SUNSET AND DIMINISHING
AFTER 03Z. KEPT SOME PROB30 GROUPS AT MOST TAF SITES THROUGH
THE MORNING WITH PREVAILING SHOWERS AND VCTS DURING THE
AFTERNOON AS CONFIDENCE IS HIGHER THAT MOST TAF SITES WOULD SEE
IMPACTS AT SOME POINT DURING THE AFTERNOON. VFR CONDITIONS WILL
BE IN PLACE WITH MVFR/IFR IN ANY SHOWER/STORM AND CIGS LOWERED
TO ILS BREAKPOINTS AT TIMES DURING CONVECTION.
GJT WATCHES/WARNINGS/ADVISORIES
CO...NONE.
UT...NONE.
UPDATE...MDA
SHORT TERM...KJS
LONG TERM...GF
AVIATION...TGJT
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