759
FXUS65 KGJT 201740
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1140 AM MDT MON JUL 20 2026
KEY MESSAGES
- SHOWERS AND STORMS WILL CONTINUE THIS WEEK EACH AFTERNOON AND
EVENING, WITH COVERAGE BECOMING MORE WIDESPREAD BY TUESDAY AND
WEDNESDAY.
- PRIMARY THREATS INCLUDE HEAVY RAINFALL, LIGHTNING, AND OUTFLOW
WINDS (30-40 MPH). SOME SMALL HAIL WILL ALSO BE POSSIBLE.
- 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 1102 AM MDT MON JUL 20 2026
A STAGNANT HIGH-PRESSURE SYSTEM REMAINS PARKED OVER THE AREA.
THIS IS LEADING TO MANY RINSE AND REPEAT DAYS WHEN IT COMES TO
THE CURRENT FORECAST. SHOWER AND THUNDERSTORM CHANCES REMAIN
EACH AFTERNOON AND EVENING, AT LEAST FOR THE FIRST HALF OF THE
WEEK. SHOWER ACTIVITY APPEARS TO BECOME MORE WIDESPREAD BY
TUESDAY AND WEDNESDAY AS A SHORTWAVE ROTATES AROUND THE HIGH
CAUSING IT TO MOVE TO OUR SOUTHEAST. THIS WILL ALLOW PWATS TO
INCREASE TO UPWARDS OF 200% OF NORMAL. PRIMARY THREATS CONTINUE
TO BE HEAVY RAINFALL, LIGHTNING, AND GUSTY OUTFLOW WINDS (35-45
MPH). SMALL HAIL IS ALSO A POSSIBILITY. WITH THAT BEING SAID,
DEPENDING ON WHERE THESE STORMS CHOOSE TO MATERIALIZE, THEY
INTRODUCE A THREAT FOR FLASH FLOODING AND DEBRIS FLOWS. THIS
REMAINS A CONCERN FOR AREAS WITH VULNERABLE TERRAIN, INCLUDING
RECENT BURN SCARS IN ADDITION TO BURN SCARS FROM PREVIOUS YEARS.
FOR GREATER DETAIL ON THE FLASH FLOODING RISK, SEE THE
HYDROLOGY SECTION BELOW.
BY MIDWEEK, THE HIGH-PRESSURE SYSTEM WILL SHIFT SLIGHTLY,
ALTERING OUR STORM TRACKS. WHILE STORMS HAVE RECENTLY BEEN
TAKING AN UNUSUAL EAST-TO-WEST PATH, THE NEW PATTERN WILL LIKELY
STEER THEM UP FROM THE SOUTH AND PERHAPS THE WEST BY LATE WEEK.
AFTER THAT SHORTWAVE PASSES TO OUR NORTH WESTERLY FLOW BECOMES
ESTABLISHED. THIS MAY ALTER THE MOISTURE ACROSS THE AREA, WHICH
IN TURN MAY CHANGE DAILY STORM CHANCES.
AS FAR AS TEMPERATURES ARE CONCERNED, DAYTIME HIGHS WILL
CONTINUE TO BE ABOVE NORMAL FOR THE NEXT FEW DAYS, WITH NEAR
NORMAL TEMPERATURES EXPECTED WEDNESDAY AND BEYOND.
A SPECIAL NOTE FOR OUTDOOR ENTHUSIASTS: PLEASE CONTINUE TO
MONITOR THE FORECAST AND ADJUST YOUR PLANS AS NEEDED. THESE
STORMS CAN DEVELOP RAPIDLY, BRINGING SUDDEN HAZARDS. YOUR BEST
BET IS TO HEAD OUT EARLY IN THE MORNING, AS STORM ACTIVITY
TYPICALLY STRENGTHENS IN THE AFTERNOON. ALWAYS ENSURE YOU HAVE
MULTIPLE WAYS TO RECEIVE WEATHER WARNINGS.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 604 AM MDT MON JUL 20 2026
ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE HIGHER
TERRAIN ACROSS THE REGION BETWEEN 18Z AND 00Z WITH MORE
SCATTERED COVERAGE OVER THE UINTA MOUNTAINS IN NORTHEASTERN UTAH
AND OVER THE SAN JUAN MOUNTAINS IN SOUTHWESTERN COLORADO.
THIS CONVECTION WILL END BY ABOUT 06Z TUESDAY. INCLUDED PROB30
IN MOST TAFS ALONG AND SOUTH OF I-70. EXPECT BRIEF PERIODS OF
MVFR IN PRECIPITATION. OTHERWISE, LOOK FOR VFR CONDITIONS AND
LIGHT WINDS THROUGH THE TAF PERIOD.
HYDROLOGY
ISSUED AT 1102 AM MDT MON JUL 20 2026
ANOMALOUS MOISTURE HAS BECOME ESTABLISHED ACROSS PORTIONS OF
EASTERN UTAH AND WESTERN COLORADO. SCATTERED THUNDERSTORMS CAPABLE
OF PRODUCING HEAVY RAIN ARE EXPECTED THIS AFTERNOON AND EARLY
EVENING. 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 STEEP TERRAIN AND RECENT BURN SCARS.
ALSO, RAIN OVER THE PAST SEVERAL DAYS HAS LEAD TO SATURATED SOILS,
WHICH INCREASE THE CHANCES FOR EXCESSIVE RUNOFF.
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...TGJT
AVIATION...DB
HYDROLOGY...TGJT
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