textproduct: Grand Junction

KEY MESSAGES

- Isolated showers and seasonable temperatures to start the work week.

- Widespread rain returns Wednesday through Friday, bringing a renewed risk of flooding and flash flooding.

DISCUSSION

Issued at 956 PM MDT Sun Oct 18 2026

ISOLATED SHOWERS AND SEASONABLE TEMPS TO BEGIN THE WORK WEEK:

Broad southwesterly flow will dominate the start of the work week, maintaining moisture advection across the region. Expect increasing cloud cover along with isolated showers through Tuesday. Modest warm air advection will nudge high temperatures closer to seasonal normals despite the increased cloud cover. While localized breezy conditions could accompany collapsing showers, organized convection is not anticipated.

WIDESPREAD RAIN RETURNS LATE-WEEK:

By Wednesday, a strong low pressure system drops southward along the California coast, while an upper level jet noses into the Four Corners region. These two features will work in tandem to bring remnant moisture from what is now Hurricane Trudy into the region, bringing the return of widespread precipitation chances. Initial model solutions depict the most likely time period for widespread showers to be Wednesday night through Thursday night. It is also important to note that a large majority of the precipitation from this system will fall as rain, with the pool of colder temperatures staying well north of the forecast area. As a result, snow levels will remain high, generally at or above 12,000 feet. Given the prospect of high-elevation rain falling onto antecedent snowpack and saturated soils from last week's precipitation, flash flooding and hydrologic impacts will be monitored closely as the system progresses. Ensemble guidance supports PWATs upwards of 250-300% of normal, providing another strong signal to monitor for potential impacts. Keep in mind that the forecast remains fluid this far out, and key details may shift over the coming days. Stay tuned for updates.

Precipitation chances continue into Friday afternoon, though coverage will gradually taper off. Meanwhile, the low pressure system will be absorbed into the main flow, driving a frontal passage through the area. This will bring cooler temperatures on Friday, dropping highs by 5 to 10 degrees compared to Thursday and potentially taking overnight temperatures back below freezing.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 516 AM MDT Mon Oct 19 2026

Mid to high level clouds will drift across the region over the next 24 hours with a few of these clouds dropping some light rainfall at times. Overall VFR is expected to prevail though IlS conditions may be met where markers are above 60kft agl. Winds will remain light through the period.

GJT WATCHES/WARNINGS/ADVISORIES

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