662
FXUS65 KGJT 210538
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1138 PM 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 1018 PM MDT MON JUL 20 2026
LITTLE CHANGE IN THE SYNOPTIC PATTERN IS EXPECTED TUESDAY WITH
HIGH PRESSURE PARKED OVER THE GREAT BASIN. HOWEVER, A FEW
MESOSCALE DEVELOPMENTS WILL PROVE PIVOTAL TO THE FORECAST.
MONSOONAL MOISTURE WILL CONTINUE TO TRICKLE BENEATH THE HIGH
TUESDAY AFTERNOON. HEIGHT FALLS PRODUCED BY WEAK SHORTWAVES WILL
INITIATE A SHIFT SOUTHEAST OF THE HIGH. IN THE MEANTIME, THIS
SHORTWAVE ENERGY WILL ENGAGE THE EXISTING MOISTURE POOL AND
PRODUCE ANOTHER AFTERNOON OF CONVECTIVE SHOWERS AND
THUNDERSTORMS. STORMS MONDAY EVENING WERE PRODUCING RAINFALL
RATES OF 1-2 INCHES PER HOUR IN PLACES, ENOUGH FOR NUMEROUS
FLASH FLOOD WARNINGS ON SUSCEPTIBLE BURN SCARS AND FLOOD PRONE
TERRAIN. THERE'S REASONABLE CONFIDENCE PRECIPITATION BECOMES
MORE WIDESPREAD WITH ADDITIONAL DYNAMIC FORCING FROM THE
SHORTWAVES. THIS SHOULD INCREASE STORM HALF- LIFE APPRECIABLY
OVER THE NEXT COUPLE OF DAYS. THEREBY, INCREASING THE LIKELIHOOD
OF MORE FLASH FLOODING AND HYDROLOGICAL CONCERN ON BURN SCARS.
STORM MOTIONS WILL STAY SLIGHTLY ECCENTRIC ON TUESDAY FAVORING
EAST TO WEST MOTIONS ONCE AGAIN.
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 /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1138 PM MDT MON JUL 20 2026
SHOWERS WITH EMBEDDED THUNDERSTORMS CONTINUE TO DRIFT WESTWARD
ACROSS THE STATE LINE INTO EASTERN UTAH LATE THIS EVENING. MOST
TAF SITES ARE CLEAR OF THIS THREAT WITH LINGERING CONVECTIVE
DEBRIS CLOUDS LEAVING CIGS AT OR ABOVE 120KFT AGL. KCNY COULD
SEE SOME LIGHT SHOWERS LINGER PAST MIDNIGHT. PLENTY OF MOISTURE
AND INSTABILITY REMAINS FOR ANOTHER ACTIVE AFTERNOON AND EVENING
EXPECTED TO IMPACT MOST TAF SITES WITH THE THREAT OF A PASSING
THUNDERSTORM WELL INTO THE EARLY MORNING HOURS OF WEDNESDAY. VFR
IS PREVAILING IN TAF SITES WITH ILS POSSIBLE IN THE PROB30
GROUPS AT SOME SITES. CONFIDENCE NOT HIGH ENOUGH FOR MVFR OR
BELOW ATTM BUT IF A HEAVY RAIN SHOWER MOVES OVER THE AIRFIELD
THIS IS VERY POSSIBLE OVER THE NEXT 24 TO 36 HOURS.
HYDROLOGY
ISSUED AT 1018 PM MDT MON JUL 20 2026
A RICH PLUME OF MONSOONAL MOISTURE HAS BECOME ESTABLISHED
ACROSS PORTIONS OF EASTERN UTAH AND WESTERN COLORADO. SCATTERED
THUNDERSTORMS CAPABLE OF PRODUCING HEAVY RAIN ARE EXPECTED TO
CONTINUE TUESDAY. 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 TERRAIN VULNERABLE TO FLASH
FLOODING AND/OR DEBRIS FLOWS. DRY CREEKS AND ARROYOS CAN FILL
QUICKLY AND WITHOUT WARNING FROM STORMS MILES AWAY.
GJT WATCHES/WARNINGS/ADVISORIES
CO...NONE.
UT...NONE.
DISCUSSION...TGJT
AVIATION...TGJT
HYDROLOGY...TGJT
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page