textproduct: Grand Junction

KEY MESSAGES

- Anomalous moisture arrives this evening and brushes the northern and central mountains with hazardous high-elevation snowfall through early Thursday.

- The higher elevations of the northern Colorado mountains have the highest probability 12"+ of snow. The remainder of the northern and central high country looks to be in the 4-10" range above 9,000 feet.

- The mild airmass may limit hazardous travel conditions to early Wednesday and Wednesday night.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 1033 PM MST Mon Feb 23 2026

The H500 hand analysis map at 24/00Z is showing an upstream split flow pattern over the upper PacNW region. The southern stream contains a strong fetch of atmospheric moisture...some 250-300 percent of normal and the northern stream has the dynamics and slightly colder air for the later part of the event. This mositure is anomalous enough that plenty will survive the trip over the upstream terrain and arrive to our northern mountains by late this afternoon. This will be another warm and very wet storm...more Sierra cement type snow for much of the event as the colder air doesn't arrive until the dendritic layer begins to dry out significantly. However the spine of our northern mountains will be quite efficient at catching this moisture and producing 10-12:1 SLRs for a good 24 hours. QPF amounts look to run in the 75th to 90th percentile over the upper Park Range and this equates to close to 2 feet of this high density snow. There should be a sharp gradient as we go down in elevation with SLRs more in the 8-9:1 range below 9500 through Wed sunset. This is scenario is similar across the Flat Tops and the central mountains to the northern San Juans though these ranges will catch less of the moisture. So bottom line is the headlines look on track for now even with an upward adjustment of QPF/snow over some of the higher peaks. The time of year...and mild airmass will again be a challenge as the impacts may be fairly minimal over the the mountain roadways during the daylight hours then turning slushy/icy overnight. Otherwise a mix of rain and snow for some of the adjacent mountain valleys and mainly rainfall in the lower elevations are expected. Temperatures will generally be running some 5 to 15 degrees above normal in most areas the next few days with clouds and moisture also keeping the overnight lows on the mild side.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 1033 PM MST Mon Feb 23 2026

IVT dissipates heading into Thursday, beginning the wind-down to the winter storm. Persistent northwesterly flow will continue to support orographically-driven snow showers through the morning over areas where near-surface moisture lingers, primarily around the northern and central Colorado mountains. By this point though, only a couple inches of additional accumulation will be favored.

A broad ridge redevelops over the majority of the western CONUS on Friday and Saturday, keeping afternoon highs around 10 degrees above normal through the weekend. Strengthening flow off the west coast around the high brings another surge of Pacific moisture onshore beginning late Saturday and lasting into the early portion of the work week. Deterministic IVT forecasts are modest to start before upper-level flow shifts southwestwards again ahead of a Pacific shortwave, and more ample moisture arrives to the Intermountain West. This looks to occur late Sunday or early Monday. Model guidance is consistent in the presence of this shortwave, though not in the timing nor the exact strength of the Pacific moisture pool. As of now, this round of precipitation does not look overly impressive with generally light accumulations over a relatively long duration.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 433 AM MST Tue Feb 24 2026

VFR conditions prevail through this afternoon. Moisture arrives across northern Colorado this evening bringing another round of showers to some terminals. KASE and KHDN are the most likely to be impacted. There is a chance that cigs will fall below ILS breakpoints and precipitation will reduce vis to MVFR thresholds at these terminals. However, the greatest impacts come late in the TAF period and beyond, so expect more details in future forecasts.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Winter Storm Warning from 6 PM this evening to 9 PM MST Wednesday for COZ004. Winter Weather Advisory from midnight tonight to midnight MST Wednesday night for COZ010-013. UT...None.