textproduct: Grand Junction

KEY MESSAGES

- Periods of moderate to occasionally heavy rain and thunderstorms will impact western Colorado and eastern Utah today.

- Warmer and drier conditions return for the weekend.

- Another push of moisture will arrive by Monday, bringing widespread moderate to heavy precipitation through midweek.

DISCUSSION

Issued at 1108 AM MDT Fri Sep 25 2026

MORE PRECIPITATION CHANCES TODAY BEFORE A DRIER WEEKEND:

A trough will be kicked out over the Desert Southwest and into the Four Corners area today. This will introduce scattered shower and storm chances across western Colorado and portions of eastern Utah. Recent HiRes guidance depicts the bulk of storm activity to be along and south of I-70. Periods of moderate to occasionally heavy rainfall can be expected out of the stronger cells. Locations that saw the sun this morning may see a quicker transition into convective mode than those who started the morning with light stratiform rainfall. All that being said, some isolated stronger storms are possible as instability remains fairly moderate. With that, some locations could see small hail and gusty outflow winds. This activity will quiet down by the overnight period as flat ridging moves back into the area. This will indicate a drier weekend, with daytime highs warming by a few degrees.

NEXT WEEK'S MOISTURE:

By Monday, the forecast becomes a bit more challenging. Another trough arrives to the PacNW coast, albeit stronger than the last one. This will work to push the ridging east of the Rockies and backing the upper flow to the southwest over the Great Basin. Moisture from a pair of tropical systems, including Polo, will be drawn into the southwest flow aloft ahead of the trough. PWATs will again return to upwards of 200% of normal, particularly in southwest Colorado and southeast Utah. This indicates the start of another wet period through at least midweek. It is important to note that some discrepancies exist between models, with the GFS consistently showing a drier solution, whereas the Euro continues to be more bullish with the moisture. Additionally, both the GFS and Euro have different placements when it comes to the location of the low pressure system. Cluster solutions also continue to be inconsistent on how to handle the moisture in addition to the upstream trough, so confidence remains low on a final solution. Bottom line is that the start of next week looks to be wetter, but whether this will be a significant/anomalous event for the Four Corners area is yet to be determined. Stay tuned for how this forecast begins to develop.

In addition to this moisture, daytime highs will also drop by a few degrees come Monday, which also means overnight lows will do the same. If you're catching what I'm putting down, that would indicate snowflakes returning to the forecast for some our highest peaks and passes. At this point, these chances look most confined to the San Juans and central Divide mountains.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1209 PM MDT Fri Sep 25 2026

Currently widely scattered showers with embedded thunderstorms possible across most the higher terrain of western Colorado becoming more widespread by 20Z and lasting through 00Z. Periods of MVFR to IFR conditions may occur near showers with lower ceilings and visbilities. Expect periods below ILS breakpoints at mountain TAF sites with prolonged MVFR conditions through about 02Z. Conditions will improve to VFR across the region after 02Z.

GJT WATCHES/WARNINGS/ADVISORIES

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