textproduct: Grand Junction

KEY MESSAGES

- Scattered showers with isolated thunderstorm chances along the higher terrain today.

- A deep surge of moisture Monday and Tuesday brings a return of showers and thunderstorms to the region. Expect scattered thunderstorms Monday especially over the higher terrain becoming more widespread Tuesday.

DISCUSSION

Issued at 1020 PM MDT Sat May 23 2026

Eastern Utah and Western Colorado are coming under a weaker westerly flow aloft between the Arctic leaf of the jet across the Pacific Northwest and the subtropical leaf moving in across Baja. A weak but deep low off the Southern California Coast moves inland Sunday night pushing into the Dessert Southwest Monday putting the region under a southerly flow that pulls deeper moisture with pwats of 0.70 inches or more up from the south. A deep cold low descending out of the Gulf of Alaska drops in along the Pacific Northwest Coastline Monday through Northern California Tuesday before bottoming out in the Great Basin Wednesday and ejecting to the northeast through the latter half of the week. As this deep system moves south, it draws the weak low north across the region Tuesday keeping the deeper moisture in the area. Models are indicating a cold front with the deep system will push the moisture out of the area Wednesday through the latter week, but there is still low confidence mid week and beyond with wide variance among the models and even the ensembles. This deep low will bring strong gusty south to southwest winds to the region Wednesday onward with very tight H500 gradients supporting 80-100 kt winds aloft over eastern Utah and westward. Due to uncertainty, we could see these stronger winds across Western Colorado. Stay tuned.

With that being said, we will see conditions tomorrow very similar to today with somewhat lighter winds. Look for another round of isolated to widely scattered light showers across the higher terrain with increased mid to upper level moisture flowing out of the Great Basin. Still not forecasting much accumulation with these though measurable precip is possible on the western slopes of rising terrain. With increased heating and temperatures running five to ten degrees warmer, can't rule out thunder with these, especially across the Flattops and Gore Mountains, and Grand Mesa through the central Colorado mountains through the afternoon. Strong downburst winds and lightning look to be the primary threat with these storms.

As the moisture surges north Monday, expect widespread showers with widely scattered thunderstorms focused more over the higher terrain. Tuesday will see increased coverage of both showers and thunderstorms with enhanced upper-level dynamics and the strongest surge of moisture. Too soon to make a call on the threats from these storms, but with a southerly steering flow, training storms could pose threats through the central and northern Colorado mountains, especially over recent fire scars. Stay tuned for more on this.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 528 AM MDT Sun May 24 2026

VFR conditions remain in control this morning across the West Slope. Light drainage winds continue in select valleys and light, variable conditions elsewhere. Cloud cover is expected to increase this morning and afternoon, but breakpoint ceilings are unlikely. There are non zero chances for showers and thunderstorms on the terrain today. PROB30 SHRA remains in the KTEX TAF for this afternoon. Chose to leave other mountain terminals out for now. 18Z TAFs may need to adjust at game time for shower development. Gusty outflow winds from these showers will be the primary aviation problem today, as rain and ceilings will likely not pose a problem in the high based shower regime. Winds will remain westerly at 10-20 mph across the region with some stronger gusts closer to the Divide. Light winds and clearing skies will resume around sunset and VFR conditions will continue overnight.

GJT WATCHES/WARNINGS/ADVISORIES

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