788
FXUS65 KGJT 162330
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
530 PM MDT THU JUL 16 2026
KEY MESSAGES
- EXPECT TERRAIN-BASED SHOWERS AND THUNDERSTORMS EACH AFTERNOON
THIS WEEK, FAVORING THE SAN JUANS, BUT SPREADING NORTH BY THE
WEEKEND.
- 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.
- DAYTIME HIGHS COOL THROUGHOUT THE WEEK, RETURNING TO NEAR-
NORMAL FOR MOST AREAS BY FRIDAY.
DISCUSSION
ISSUED AT 1235 PM MDT THU JUL 16 2026
DAILY SHOWERS AND THUNDERSTORMS:
PERSISTENT HIGH PRESSURE ALOFT KEEPS A PLUME OF MOISTURE OVER MUCH
OF THE WEST THROUGH AT LEAST THIS WEEKEND, POTENTIALLY BEYOND.
GUIDANCE KEEPS THE MOST MOISTURE RICH PART OF THIS PLUME (IN TERMS
OF PWAT ANOMALIES) TO OUR WEST, BUT ENSEMBLES PLACE PWATS OF 130-
200% OF NORMAL OVER OUR FORECAST AREA THIS WEEK. THE ECMWF ENS AND
GFS ENS HAVE CONSISTENTLY SHOWN DIFFERENCES IN THE MAGNITUDE OF THE
ANOMALIES, WITH ECMWF ENS CONTINUING TO FAVOR A MUCH MORE MOIST
SETUP WITH MAX PWATS CLOSER TO 200% AT TIMES. THIS MOISTURE BRINGS
DAILY CHANCES OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND
EVENING THROUGH NEXT WEEK.
TODAY'S AFTERNOON CONVECTION HAS BEGUN ALONG THE HIGHER TERRAIN, AND
WILL GRADUALLY INCREASE IN COVERAGE THROUGH THE AFTERNOON. QPF
FAVORS THE SAN JUAN MOUNTAINS, WHERE INCREASED MOISTURE HAS ALLOWED
FOR SHOWERS AND STORMS DURING THE PRECEDING DAYS. ELEVATED POPS
HAVE MORE NORTHWARD COVERAGE TODAY THAN THE PREVIOUS DAYS
DURING THIS PERIOD OF INCREASED MOISTURE. HOWEVER, AREAS THAT
STILL HAVE DRY LOWER ATMOSPHERES MAY SEE MORE VIRGA SHOWERS/RAIN
NOT REACHING THE GROUND MIXED WITH SOME SHOWERS PRODUCING
MEASURABLE PRECIPITATION. EACH DAY THE MOISTURE WILL ADVECT
FURTHER NORTH/NORTHEAST, ALLOWING FOR MORE WIDESPREAD CHANCES
OF SHOWERS AND THUNDERSTORMS BY THIS WEEKEND.
WHILE MOISTURE IS A RELIEF FOR DROUGHT CONDITIONS, IT ALSO CREATES A
RISK OF FLASH FLOODING AND DEBRIS FLOWS, INCLUDING OVER THE BURNS
SCARS OF THE GOLD MOUNTAIN, FERRIS, AND BABYLON FIRES. 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.
DECLINING TEMPERATURES:
TEMPERATURES WILL GRADUALLY DECREASE FOR THE REMAINDER OF THE
WEEK THANKS TO INCREASED CLOUD COVER DURING PEAK HEATING.
GUIDANCE CONTINUES TO FAVOR ANOTHER DROP IN TEMPERATURES NEXT
WEEK, POTENTIALLY LEADING TO BELOW-NORMAL TEMPERATURES.
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 528 PM MDT THU JUL 16 2026
STORMY WEATHER CONTINUES FOR THE MAJORITY OF THE REGION. MOST
TERMINALS (ASIDE FROM HDN AND VEL) MAY SEE RAINFALL THIS EVENING
AND/OR TOMORROW AFTERNOON. GUSTY OUTFLOW WINDS UP TO 35 KTS WILL
BE POSSIBLE, AND HIGHER ELEVATION TERMINALS, PARTICULARLY ASE
AND EGE COULD OCCASIONALLY DROP BELOW ILS BREAKPOINTS. HEAVIER
RAIN COULD ALSO DROP VIS TO MVFR, THOUGH AREAS WHERE THIS WILL
OCCUR ARE TOO UNCERTAIN AT THIS TIME, AND THUS VIS REDUCTIONS
HAVE NOT BEEN INCLUDED IN ANY TAF'S.
HYDROLOGY
ISSUED AT 1235 PM MDT THU JUL 16 2026
AN ANOMALOUS PLUME OF MOISTURE CONTINUES TO ROTATE INTO UTAH AND
WESTERN COLORADO THIS AFTERNOON, WITH A SLIGHT UPTICK COMPARED TO
YESTERDAY. THE SAN JUANS REMAIN A BULLSEYE IN PRECIPITATION
FORECASTS THIS AFTERNOON AND AGAIN ON FRIDAY, MAINTAINING FLASH
FLOOD THREATS REDEVELOPING EACH AFTERNOON. HOWEVER, AVAILABLE
MOISTURE IS HIGHER MOVING WEST INTO UTAH, WHICH LEAVES THE POTENTIAL
FOR ISOLATED STORMS TO PRODUCE HOURLY RAINFALL RATE OF 1-2 IN.
THEREFORE, AREAS OF CONCERN REMAIN UNCHANGED FROM THE PREVIOUS
FORECAST FOR THIS AFTERNOON.
STORMS OVER THE LAST 24 TO 48 HOURS HAVE ONLY 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 DURING YESTERDAY'S CONVECTION;
WHICH IS MORE THAN SUFFICIENT TO CREATE ISSUES IN OUR STEEP, ROCKY
TERRAIN 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 HYDRO 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...ERW
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