137
FXUS65 KGJT 171802
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1202 PM MDT FRI JUL 17 2026
KEY MESSAGES
- EXPECT SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING
THROUGH EARLY NEXT WEEK. WIND GUSTS UPWARDS OF 45 MPH AND
SMALL HAIL ARE POSSIBLE WITH THESE STORMS.
- LOCALIZED HEAVY RAINFALL WILL HAVE THE ABILITY TO PRODUCE
FLASH FLOODING AND DEBRIS FLOWS IN VULNERABLE TERRAIN,
INCLUDING AREAS NEAR AND DOWNSTREAM OF BURN SCARS.
DISCUSSION
ISSUED AT 1047 AM MDT FRI JUL 17 2026
THERE WILL BE VERY LITTLE SHIFT IN THE PATTERN ALOFT OVER THE NEXT
FEW DAYS. MOISTURE CONSISTING OF PWAT VALUES AROUND 150-200 PERCENT
OF NORMAL HAS BECOME ESTABLISHED ACROSS THE REGION. THIS MOISTURE IS
SUPPORTING DAILY SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON AND
EVENING HOURS. INITIATION WILL BE FAVORED OVER THE HIGHER TERRAIN
BEFORE SPREADING OVER THE VALLEYS AS OUTFLOWS DEVELOP. ADDITIONAL
DEVELOPMENT IS POSSIBLE WHERE THESE OUTFLOWS COLLIDE WITH EACH OTHER
AND THE HIGHER TERRAIN. ISOLATED STORMS AND SCATTERED SHOWERS
MAY LINGER THROUGH THE OVERNIGHT. LIGHTNING AND HEAVY RAIN WILL
BE THE PRIMARY THREATS, WITH SMALL HAIL AND GUSTY OUTFLOW WINDS
UP TO 35-45 MPH ON THE TABLE AS WELL. HEAVY RAINFALL COULD
RESULT IN FLASH FLOODING AND DEBRIS FLOWS, ESPECIALLY OVER AREA
BURNS SCARS. THE HYDROLOGY SECTION BELOW DISCUSSES THIS RISK IN
GREATER DETAIL. THESE STORMS CAN DEVELOP QUICKLY, SO BE SURE TO
MONITOR THE FORECAST AND HAVE A WAY TO RECEIVE WEATHER ALERTS,
ESPECIALLY IF YOU ARE VISITING OR RESIDE BELOW TERRAIN THAT IS
VULNERABLE TO FLASH FLOODING, INCLUDING DOWNSTREAM OF ACTIVE
FIRES. THIS PATTERN WILL CONTINUE INTO NEXT WEEK, SO EXPECT
SIMILAR WEATHER EACH DAY THROUGH THEN. THE ONLY DIFFERENCE WILL
BE SLIGHT VARIATIONS IN WHERE THE CONVECTION FORMS AND DRIFTS
OFF THE TERRAIN. TEMPERATURES WILL RUN NEAR NORMAL TO SLIGHTLY
BELOW NORMAL FOR THE NEXT SEVERAL DAYS.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 520 AM MDT FRI JUL 17 2026
INCREASED MOISTURE IN THE REGION WILL BRING ANOTHER DAY OF SHOWERS
AND THUNDERSTORMS. ACTIVITY HAS BEGUN IN THE SOUTHERN MOUNTAINS, AND
WILL INCREASE IN COVERAGE THROUGH THE AFTERNOON. AFTER 00Z ACTIVITY
WILL GRADUALLY DIMINISH. CONCERNS ARE LIGHTNING, GUSTY OUTFLOW
WINDS, AND BRIEF PERIODS OF HEAVY RAINFALL. THERE IS A LOW
PROBABILITY OF MVFR CONDITIONS OCCURRING WITH HEAVIER RAINFALL, BUT
OTHERWISE VFR CONDITIONS ARE EXPECTED TO PREVAIL. WINDS WILL BECOME
LIGHT AND VARIABLE OVERNIGHT.
HYDROLOGY
ISSUED AT 1047 AM MDT FRI JUL 17 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 REPORTED OVER 0.5
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...TGJT
AVIATION...TGJT
HYDROLOGY...ERW
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