textproduct: Grand Junction

KEY MESSAGES

- Mostly dry and warm conditions prevail through the weekend with a gradual increase in afternoon shower and thunderstorm activity each day.

- Daytime highs remain 5 to 10 degrees above normal through Sunday before a shift to cooler temperatures for next week. - Unsettled conditions persist for much of next week as moisture continue to feed into the area.

DISCUSSION

Issued at 1030 PM MDT Thu Sep 10 2026

The 11/00Z H500 hand analysis map is showing a high amplitude Rex pattern over the E.Pac leading to downstream troughing over W.Canada to near the US border. A jet max aloft is moving over zonal flow over the northern states which is pulling moisture across the northern Great Basin this evening according to GOES ALPW. This moisture as weak ascent from the jet looks to at least pull some thicker cloud cover across the norther toward sunrise with some small chances of some sprinkles hitting the ground. The CAMS/RRFS are bit more bullish with this an have introduces some low end PoPs through the AM hours mainly north of I-70. The focus for convection shift more southward by mid-day and through the evening as SubTrop moisture being pulled northward into the 4 Corners region arrives. Again the ascent may be coming from the stronger winds aloft which will combine with orographics and favor the southern CWA terrain before settling down through the late evening hours. Profiles show a lot of dry air to overcome in the low layers with dewpoints still in the single digits to teens currently. This sets the stage for gusty outflow winds being more of a threat than heavy rainfall. The dry air and breezy winds in the afternoon also look to bring localized areas of critical fire weather. As upstream troughing deepens over and swings through the PacNW this weekend...SubTrop high pressure will be pushed over and East of the Southern Rockies. This will give a more direct feed of moisture strengthening SW flow aloft. The strongest forcing remains well upstream near the progressive trough. Forcing over our CWA looks tied more to orographics for storm initiation on Saturday with outflow boundary interactions bringing some chance for storms over the lower elevations. Sunday appears to have an uptick in activity as the upstream trough and jet aloft begins to swing through the Intermountain West. The better chances could be overnight into Monday with weak surface frontal forcing undercutting the ascent aloft. PWAT during this time looks to run some 150 to 200 percent of normal over all but the northwest CWA where the SW fetch aloft will be from a drier upstream source. Temperatures through the weekend look to stay above normal then cool Monday with the weak frontal passage and lower heights aloft. A static pattern of upstream troughing over the PacNW and downstream high pressure over the Southeast US means persistent moist SW flow into the Great Basin. So cooler and unsettled conditions look to linger through much of next week. We're getting to that time of year when overnight precipitation is likely to bring a short- lived dusting of snow on the top of the peaks at sunrise as well.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 535 PM MDT Thu Sep 10 2026

VFR conditions are forecast through the TAF period. Overnight, expect light diurnal winds along with the development of scattered to broken middle to high level clouds. A few isolated showers and a possible thunderstorm may develop during the morning hours at KVEL and KCNY before moving eastward.

GJT WATCHES/WARNINGS/ADVISORIES

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