textproduct: Grand Junction

KEY MESSAGES

- Afternoon showers and thunderstorms continue today, with a localized flash flooding risk.

- Gusty winds return Wednesday and Thursday, with afternoon gusts to around 25 to 35 mph for much of the region.

- A chance for additional monsoonal moisture arrives for the Labor Day weekend.

DISCUSSION

Issued at 1216 PM MDT Wed Sep 2 2026

SCATTERED SHOWERS AND THUNDERSTORMS TODAY:

Thunderstorms have been ongoing through the morning and early afternoon today, and will continue while moisture lingers across the region and a jet streak aloft provides lift. This morning's 300mb objectively analyzed map from the Storm Prediction Center shows this jet streak stretching from southern California through eastern Utah, with divergence aloft aligned with the southern side of the jet streak. Guidance shows this jet streak moving across our CWA through the day as a trough pushes into the West. This morning's 18Z sounding from GJT shows that precipitable water remains elevated, with today's value exceeding the 90th percentile. Given the upper-level support and moisture, showers and storms will persist through the evening, with coverage becoming isolated after sunset. The primary concern with this activity is heavy rainfall, which could cause flash flooding in localized areas, especially around newer burn scars and areas of susceptible terrain. Small hail and gusty outflow winds are also possible.

GUSTY AND DRIER THROUGH FRIDAY:

Afternoon wind gusts will be stronger today through Friday, with the strongest forecast gusts being around 25 to 35 mph. This is due to an increased pressure gradient and periods of stronger winds aloft as the trough moves deeper into the West. However, one caveat to consider is that if cloud cover exceeds what is forecast the magnitude of gusts could be weaker.

Drier air moves in tonight which will keep precipitation chances pretty low through the rest of the workweek. However, some isolated afternoon convection is possible over the higher terrain tomorrow and Friday.

RETURN OF MOISTURE THIS WEEKEND:

Guidance continues to favor a moisture push this weekend, with the most anomalous moisture moving in on Sunday. How this forecast develops is largely dependent on the tropical storm activity in the Pacific, but models have consistently shown this moisture transport between runs. Increased moisture could allow for more widespread precipitation, so be sure to stay tuned to the forecast for this weekend as it develops.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1156 AM MDT Wed Sep 2 2026

Showers and thunderstorms have formed along a boundary stretching from southeast UT into northwest CO. A few strong thunderstorms with heavy rainfall and some gusty outflow winds will work eastward this afternoon along that boundary. Wind gusts to 40 mph have been recorded thus far with heavy rain. This will produce a few TEMPO breakpoint ceilings and visibility conditions for terminals in the path of storms. Given the uncertainty in shower coverage, kept TEMPO language somewhat basic for these storms. Showers and storms will taper this evening, with a few evening showers hanging on over northeast UT and northwest CO closer to a weak frontal boundary up there. VFR conditions return overnight and continue with light winds into Thursday morning.

GJT WATCHES/WARNINGS/ADVISORIES

CO...None. UT...None.