textproduct: Grand Junction

KEY MESSAGES

- Periodic rain/snow showers and thunderstorms will favor the higher terrain early this week, especially north of I-70.

- The coverage of showers and storms increases on Tuesday. Periods of moderate to heavy snow and slick travel are possible over the northern and central Divide mountains with potential impacts through Wednesday afternoon.

DISCUSSION

Issued at 1032 PM MDT Sun May 3 2026

Light showers are advecting northward across southeast Utah and southwest Colorado as the leading wave from a cut off low moving down the California coast. We are seeing some isolated lightning activity with these showers and gusty winds as precip is trying to overcome the dry air at the low levels. Showers reach the I-70 corridor by early Monday morning and the focus for shower and thunderstorm activity looks to be along and north of the I-70 corridor Monday afternoon and evening. Temperatures remain mild Monday due to the southwest flow with this boundary stalling a bit along the northern Colorado/Wyoming border as a deeper and colder trough drops southward across the Northern Rockies and Northern High Plains.

Tuesday appears to be the most dynamic day as the cut off low moves into Arizona and the deeper trough drops southward across the north, bringing with it a pretty decent cold front. The heaviest precipitation rates appear to occur along this frontal boundary so Tuesday could be met with periods of moderate to heavy precipitation and of course convective potential. Snow is expected above 9000 feet but the greatest impacts and accumulations look to occur over the northern and central Front Range mountains and foothills. There is some uncertainty with snowfall accumulations given how far west this frontal boundary will set up and the depth of colder air, but do anticipate some slick conditions over the passes, especially Rabbit Ears and Vail Passes Tuesday afternoon through Wednesday morning. Held off on issuing any Winter Weather highlights at this time but could see some late season impacts along the northern and central divide mountains. Want to see a couple more model runs before honing in on details with timing, amounts and especially snowfall rates. Be prepared for travel impacts if traveling east towards the Front Range Tuesday and Wednesday and also visit weather.gov/bou for info on the east slope.

Lingering moisture and increased instability will allow for scattered showers and storms through late in the week. The passage of this system will cause temperatures to drop below normal on Tuesday and Wednesday before warming back to above normal levels late in the week.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 525 AM MDT Mon May 4 2026

Showers continue to move across the area from southwest to northeast thanks to a passing wave overhead. Midlevel to some low level ceilings are being reported at this hour with some light rain mixed in. Mostly VFR conditions are being reported but some MVFR can't be ruled out this morning as this wave continues to move across the area. Daytime heating will work on available moisture allowing some showers/storms to fire this afternoon mainly along the I-70 corridor northward. Many PROB30 groups are included in TAFs to account for this possibility. Some gusty afternoon winds of 20 to 25 kts are also expected. While VFR should remain the primary flight category, brief MVFR will remain possible near the heavier showers/storms.

GJT WATCHES/WARNINGS/ADVISORIES

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