textproduct: Grand Junction

KEY MESSAGES

- Freeze Warnings are in place for the Yampa River Basin, central Colorado River Basin and SW Colorado valleys tonight through Friday morning.

- Scattered showers and isolated thunderstorms will continue today through Friday, favoring the higher terrain with rain in the lower elevations and some accumulating snow above 8500 feet.

- Temperatures warm above average this weekend with overall drier conditions and isolated showers on the mountains each afternoon.

- Precipitation chances increase again late Sunday into early next week.

DISCUSSION

Issued at 1153 AM MDT Thu Apr 30 2026

Isolated to scattered light showers have developed across much of the higher terrain late this morning as a result of some jet support associated with a shortwave trough traversing the area from north to south. Showers are of a convective nature and seem more instability driven but precipitation rates remain fairly light due to weak flow aloft. Meanwhile a cut off low will move across the Baja and into southern Arizona and New Mexico today but remains to our south that we will not see much influence from it. This low is resulting in some easterly upslope flow on the northeast side into the Front Range mountains, so they appear more favored at this time while our accumulations look light. On Friday, the shortwave trough will continue moving south with the frontal boundary as depicted by a 700 mb convergence axis setting up over the San Juans, where the better snow accumulations are expected. Even so, temperatures remain fairly warm with not much in the way of cold air so accumulations remain below advisory thresholds. The peak period comes Friday afternoon as well so roads primarily would be wet but could be slushy at the higher pass level. So, just be prepared for slick road conditions if traveling over the passes. Upper level ridging will be building back in across the Intermountain West late Friday so this shortwave could be fighting with suppression and drier northerly flow late Friday afternoon into the evening from this high, leading to some stabilization across much of the area with exception of the San Juans as the convergent boundary settles over there until Friday evening. Most lower valleys should remain dry or spotty with some light rain showers from time to time, but seems like higher terrain is focused for better shower activity through Friday.

As far as temperatures are concerned, highs will average around 5 or so degrees below normal with slight CAA from this passing shortwave. Overnight lows will be a concern tonight through Friday morning for the NW Colorado valleys (Yampa River Basin), Upper Colorado River Basin and SW Colorado valleys where temperatures will dip into the 20s so issued a Freeze Warning for these areas. Sub-freezing temperatures are possible again in some of these higher valleys Friday night into Saturday morning after skies clear behind this shortwave trough as it moves south out of the region Friday night.

THIS WEEKEND AND NEXT WEEK:

Upper level ridging begins to build back in come Saturday. This will lead to above normal temperatures through the weekend. Isolated to scattered afternoon showers will continue in the mountains, especially in the San Juans as we hang on to remnant moisture. All other areas will remain relatively dry, with light winds. Models seem to be in agreement about a low pushing across the Great Basin Monday bringing our next chance for rain. This system is still far out, and models are bouncing between more and less total precip from this system, but the trend is for pretty insignificant amounts for eastern Utah and the far western Colorado with more possible in the central and northern Colorado mountains however amounts came down quite a bit with the latest run. With that being said, in lieu of this system, temperatures are trending back towards normal for most of next week with the troughing overhead and increased cloud cover.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1153 AM MDT Thu Apr 30 2026

Showers and thunderstorms will continue across the region this afternoon, primarily around the mountains. A few adjacent valleys could see gusty outflow winds as showers move off of the terrain. Included TEMPO wind conditions at several terminals to account for the gusty winds. Can't rule out some small hail today as well. Breakpoint ceilings will be a problem too, as the frontal boundary works its way through. Northwest Colorado and northeast Utah will see conditions improve this evening, with the Divide mountains and southwest Colorado holding on to clouds and precipitation into the morning hours of Friday and beyond.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Freeze Warning from midnight tonight to 9 AM MDT Friday for COZ001-002-008-021>023. UT...None.