textproduct: Grand Junction

KEY MESSAGES

- Near-record heat continues Tuesday for western Colorado and eastern Utah.

- Daytime highs for the lower elevations will remain in the triple digits through at least Wednesday.

- Terrain based showers and thunderstorms increase in coverage each afternoon, with a threat for flash flooding becoming more likely by mid to late week.

DISCUSSION

Issued at 1103 PM MDT Mon Jul 13 2026

Some decent precipitation fell today over the southern half of the area with QPF reports around 0.3 to 0.8 inches at some sensors across southeast Utah and southwest Colorado with some of the storms today, with some locally higher amounts in some areas. The high pressure center remains over Wyoming with our CWA in the easterly flow on the southern side of the circulation. This will continue to allow our moisture to increase and eventually spread further north and east as the high shifts a bit eastward by late this week. At this time, the axis of strongest moisture advection remains across Arizona into Nevada and western Utah. This axis trickles into the west slope by late this week into the coming weekend. Relative humidities and dew points have responded where dew points are in the 40s for much of the area with 50s across the far southern valleys. PWAT on our 00Z GJT sounding was up to 0.76 inches, which is quite a jump from yesterday's 0.46 inches. We will see daily chances of showers and storms with areas along and north of I-70 seeing gusty winds more than wetting rain, while areas south of I-70 see better wetting rain at least through Tuesday. Triple digits are once again in the cards for some desert valleys but relief is in sight as this moisture works its way northward with more widespread shower and thunderstorm coverage Thursday onward. Expect temperatures to also come down a bit with increased clouds and showers mid to late this week. PWATs look to increase to near an inch and above for the southeast and southwest Colorado areas by Thursday and Friday into the coming weekend with that deeper moisture plume working its way eastward. The biggest concern with this moisture and expected rainfall will be flash flooding risk on the most recent burn scars and wildfires ongoing. Although the rain will help and be beneficial due to our ongoing drought, burn scar flooding risk comes with that as heavy rain potential increases.

The upper level pattern remains pretty stagnant over the remainder of the long term forecast. West Coast troughing will make some attempts at flattening the upper level ridge. However, models remain intent on keeping the ridge arced over the Rockies into next week. Extratropical moisture in the Southwest could get a lending hand from a potential tropical depression offshore of southern Mexico. As this feature lifts north and west, our moisture supply might benefit handily from it. It's still premature to get focused on this feature. However, it does look like our hot, dry pattern could be shifting into more of a late summer regime with daily showers and thunderstorms through much of next week as this moisture looks to remain in place.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1143 PM MDT Mon Jul 13 2026

Isolated showers are moving eastward through eastern Utah early this morning and should be out of the area over the next few hours leaving mainly mid to high level cloudiness. Moisture continues to increase across the area and this should lead to another round of scattered showers and thunderstorms Tuesday afternoon. Wind remains the main threat though the atmosphere is beginning to support moderate to heavy rainfall rates as well. Confidence is low for timing and coverage near TAF sites but KTEX...KDRO and KGUC will be favored for storms nearby in this forecast cycle.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Extreme Heat Warning until midnight MDT tonight for COZ001-002- 006-007. UT...Extreme Heat Warning until midnight MDT tonight for UTZ024-027.