379
FXUS65 KGJT 190437
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1037 PM MDT SAT JUL 18 2026
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS WILL CONTINUE EACH AFTERNOON AND
EVENING THROUGH AT LEAST EARLY NEXT WEEK.
- MAIN THREATS WITH THESE STORMS INCLUDE LIGHTNING, LOCALIZED
HEAVY RAINFALL, AND GUSTY OUTFLOW WINDS (35-45 MPH).
- THESE STORMS HAVE THE ABILITY TO PRODUCE FLASH FLOODING AND
DEBRIS FLOWS IN VULNERABLE TERRAIN, INCLUDING AREAS NEAR AND
DOWNSTREAM OF BURN SCARS.
DISCUSSION
ISSUED AT 1004 PM MDT SAT JUL 18 2026
A FEW SHOWERS AND THUNDERSTORMS ARE DRIFTING SOUTHWESTWARD IN
EASTERN UT THIS EVENING. THIS LEFTOVER CONVECTION WILL CONTINUE
TO DECAY. STRATIFORM STORM DEBRIS WILL STICK AROUND IN SOME
FASHION INTO THE MORNING HOURS. THIS IS ONLY WORTH MENTIONING
FOR ITS POTENTIAL TO TEMPER CONVECTIVE INITIATION ON SUNDAY
MORNING. BUT...IT'S NOT IF, BUT RATHER WHEN WILL STORMS FIRE
OFF AGAIN ON SUNDAY. LITTLE CHANGE IN THE AIR MASS WILL SPELL
OUT A RINSE AND REPEAT FORECAST SUNDAY AFTERNOON. THE HIGH DOES
AMPLIFY SOME, SO AFTERNOON HIGHS LOOK TO TREND UP WHERE CLOUD
COVER AND SHOWERS DON'T IMPEDE HEATING. A FEW HOT SPOTS COULD
GET SOME COOLING BY EVENING GIVEN THE LIKELY OUTFLOWS PINBALLING
AROUND THE REGION. GENEROUS CAPE ON FORECAST SOUNDINGS, ALONG
WITH RICH PWAT VALUES WILL ENSURE THUNDERSTORMS RETAIN THEIR
ABILITY TO PRODUCE HEAVY RAINFALL RATES, SMALL HAIL, GUSTY
WINDS, AND THE COLLATERAL IMPACTS THAT COME ALONG, NAMELY FLASH
FLOODING. STORM MOTIONS WILL BE SIMILAR TO TODAY, PUSHING EAST
TO WEST AGAIN SUNDAY AFTERNOON.
WITH HIGH PRESSURE FIRMLY ENTRENCHED OVER THE WEST, TEMPERATURES
WILL CONTINUE TO TREND A FEW DEGREES OVER AVERAGE THE FIRST HALF
OF THE WORK WEEK. DAILY SHOWERS AND THUNDERSTORMS COULD KEEP
HOPES UP FOR COOLER EVENINGS, ESPECIALLY WHERE WE CAN INCREASE
SHOWER COVERAGE ON THE MOUNTAINS. UNFORTUNATELY, WE ARE STILL
WAITING FOR BETTER COVERAGE OF MOISTURE TO DELIVER ON THAT
PROMISE. MODEL SOUNDINGS DO INCREASE PWAT VALUES TUESDAY AND
WEDNESDAY, AS WELL AS RETAIN GOOD FORCING. A SHIFT IN THE HIGH'S
POSITION LOOKS INEVITABLE TOO. THIS WILL SHIFT STORM MOTIONS
AND MOISTURE TRANSPORT SOMETIME AROUND WEDNESDAY TOO. MODELS
BACK OFF ON TEMPERATURES MID WEEK, STRIPPING SOME OF THE TRIPLE
DIGITS OUT OF THE FORECAST. DETERMINISTIC MODELS HINT AT THE
CENTER OF THE HIGH SHIFTING EAST NEXT WEEKEND. STILL TOO EARLY
IN THE GAME FOR THAT, BUT THAT WILL REMAIN A PIVOTAL FORECAST
DETAIL AS THE WEEK WEARS ON.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 519 PM MDT SAT JUL 18 2026
SHOWERS AND THUNDERSTORMS ARE ONGOING THROUGHOUT THE AREA, WITH
MOST OF THE ACTIVITY GRADUALLY DIMINISHING AFTER 00Z. THE MAIN
THREATS CONTINUE TO BE LIGHTNING, BRIEF HEAVY RAINFALL, AND
GUSTY OUTFLOWS (25-30KTS). SHOWERS WILL THEN STRATIFORM OUT FOR
THE EVENING BEFORE COMING TO AN END. WINDS WILL RETURN TO LIGHT
AND TERRAIN DRIVEN PATTERNS FOR THE OVERNIGHT PERIOD. SKIES WILL
ALSO BEGIN TO CLEAR OUT OVERNIGHT, BUT MID LEVEL DEVELOPMENT IS
LIKELY TO DEVELOP AGAIN SUNDAY AFTERNOON, ALONG WITH A SIMILAR
AFTERNOON THUNDERSTORM SETUP AS SATURDAY. BRIEF MVFR CONDITIONS
CANNOT BE RULED OUT IN AND AROUND THUNDERSTORMS, BUT VFR
CONDITIONS WILL LIKELY PREVAIL THROUGH THE TAF PERIOD ELSEWHERE.
HYDROLOGY
ISSUED AT 1012 AM MDT SAT JUL 18 2026
ANOMALOUS MOISTURE HAS BECOME ESTABLISHED ACROSS PORTIONS OF
EASTERN UTAH AND WESTERN COLORADO. RAINFALL RATES OF 1-2 INCHES
PER HOUR WILL BE POSSIBLE WITH THE STRONGER STORMS. THESE RATES
COULD LEAD TO FLASH FLOODING AND DEBRIS FLOWS ESPECIALLY OVER
RECENT BURN SCARS.
STORMS OVER THE LAST FEW DAYS HAVE HELPED PRIME LOWER LEVELS OF
THE ATMOSPHERE AND SATURATE THE GROUND WHERE RAIN WAS OBSERVED.
SEVERAL LOCATIONS ACROSS SOUTHWEST COLORADO HAVE REPORTED 0.5
TO 1.0 INCHES OF RAIN WITHIN 30 MINUTES; WHICH IS MORE THAN
SUFFICIENT TO CREATE ISSUES IN OUR STEEP, ROCKY TERRAIN THAT IS
ALREADY SUSCEPTIBLE TO FLASH FLOODING. THIS ENVIRONMENT ALSO
TRIGGERS HEIGHTENED AWARENESS OVER RECENT (OR ACTIVELY BURNING)
FIRES, DUE TO THE BURNT GROUND'S INABILITY OF ABSORBING MOISTURE
UNDER HEAVY RAINFALL. AS SUCH, WE CONTINUE TO EMPHASIZE THE
POTENTIAL FOR FLASH FLOODING AND DEBRIS FLOWS IN THIS REGIME.
AS A REMINDER: KEEP AN EYE ON OUR FORECASTS THROUGH THE END OF
THE WEEK AND STAY TUNED FOR UPDATED HYDROLOGY ALERTS IF
VISITING OR IF YOU RESIDE BELOW VULNERABLE TERRAIN TO FLASH
FLOODING AND/OR DEBRIS FLOWS. STORMS ACROSS THE WEST DEVELOP
QUICKLY, LEAVING LITTLE ROOM FOR LEAD TIME IN FLASHY TERRAIN.
GJT WATCHES/WARNINGS/ADVISORIES
CO...NONE.
UT...NONE.
DISCUSSION...LTB
AVIATION...TGJT
HYDROLOGY...TGJT
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