textproduct: Grand Junction

KEY MESSAGES

- Widespread rain and mountain snow returns Saturday evening through early Monday as a Pacific system works across the Rockies. - Snow levels will drop to near mountain bases during the overnight and early morning hours but the highest amounts will generally remain above 9000 feet.

- Mountain passes are likely to become slushy to snow packed during the nighttime hours with melting expected during daylight hours.

- The cooler and unsettled weather persists through the work week and possibly into next weekend.

DISCUSSION

Issued at 900 PM MDT Fri Apr 24 2026

Seems like a very non late-April weather pattern in place on the 25/00Z H500 hand analysis map this evening. There is a very blocky pattern over the higher latitudes reaching into the northern CONUS. This includes anomalous low pressure over the Canadian Prairies and off the Canadian Maritimes with amplified ridging squeezed between these lows and also off the the West Coast. The northern mid-latitudes are on the fringe of these large low pressure systems while to the South zonal westerlies dominate the flow. A cold front tied to the western low is dropping toward our northern border late this evening and is likely to sag past Highway 40 overnight. This front likely washes out or lifts northward tomorrow as the southerly flow increases aloft. In the south water vapor is showing a shearing wave is moving through Utah which will reach our southern CWA after midnight. The models want to pop some weak convection as this wave releases instability. Can't imagine measurable precip but rather virga/ACCAS...but may need some low pops overnight.

The gyre to the north shifts northward on Saturday and re- orients SW to NE which will slingshot a system off the California coast through the Intermountain West to the Central Rockies Saturday night into Sunday. The SubTrop jet remains moderately strong and active which will arc northward in the developing SW flow ahead of the approaching Pacific wave. Theta surfaces show a strong moisture advective signature nosing out of the Baja...across the 4 Corners by late tomorrow afternoon. This anomalous PWAT will combine with increasing large scale ascent from the approaching system while also utilizing strong SW orographics to release instability and lead to widespread accumulating precipitation. QPF amounts of two- thirds to an inch will be possible over favored SW facing slopes with a tenth to near 1/3 of an inch over the valleys with this first pulse Saturday night through early Monday. This warm system means low liquid to snow ratios of 8-12:1 through the event with the highest accumulations above 9500 feet. The biggest impacts to roadways remain limited to the overnight and early morning hours into Sunday. Amounts on vegetation may reach 6-12 inches over the higher peaks of the San Juans/West Elks/Elks/Grand Mesa/Flat Tops with varying amounts on roadways due to melting. Still not overly confident on prolongs and widespread winter hazards at this point.

Other threats on Sunday include thunderstorms as the main energy rolls through. Overall instability will be somewhat tempered by the thicker cloud cover and precipitation but heavier precipitation rates/temporary lower snow levels can certainly be expected along with the lightning threat. However this unsettled pattern is likely to keep snow going over portions of the high country well into Tuesday before we get a short break mid-week.

The second pulse Monday into Tuesday will associated with the colder vortex to the north and this could lead to lower snow levels and higher snow ratios which we will continue to monitor. With this unsettled weather, expect temperatures to remain near to below normal.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1135 AM MDT Sat Apr 25 2026

Mid and high level clouds will traverse the area throughout the day. Virga or very light showers are possible at times today. Winds will be gusting again today into the afternoon hours, with values in the 20-30 kt range. Winds begin to decrease in magnitude as we move closer to nightfall.

For tonight into Sunday morning, low to mid level clouds and light showers will begin to move in from the southwest. Precipitation chances increase at all terminals through the night. Cigs will be dropping below ILS breakpoints at the mountain terminals. Other terminals also have the possibility to drop below those breakpoints as well. MVFR/IFR conditions are possible due to the lowering cigs and decreased visibility where there is active shower activity.

GJT WATCHES/WARNINGS/ADVISORIES

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