textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Warming and drying trend expected through the weekend.

- Cold front Monday-Tuesday may usher in cooler, breezy and unsettled weather for much of next week.

Through Friday: Northerly flow and weak atmospheric instability will support isolated convective showers this afternoon, primarily along the Continental Divide. Otherwise, temperatures will remain unseasonably cool across southwest Montana, with highs restricted to the 50s (roughly 10 degrees below normal for Butte). Western Montana will see highs in the 60s, while the lower elevations of north-central Idaho will approach 80 degrees.

Friday will feature a warming trend, with afternoon temperatures increasing by 5 to 7 degrees across the Northern Rockies. Scattered showers are expected Friday afternoon and evening across northwest Montana and along the Divide. Impacts will remain limited to brief, localized rainfall and wind gusts up to 25 mph. However, sufficient instability may trigger an isolated thunderstorm within Glacier National Park.

This Weekend/Water Safety: A significant warming trend will bring summer-like temperatures to the region by the weekend. With the warm air temperatures, outdoor recreation will likely increase around area lakes and rivers. Please be aware that local waterways continue to run extremely cold due to ongoing mountain snowmelt. Plunging into cold water without acclimatization can induce cold water shock, which drastically alters breathing, heart rate, and blood pressure, creating life- threatening conditions. Always wear a life jacket to stay afloat and exercise caution. For more information on cold water hazards, visit weather.gov/safety/coldwater.

Early to Mid-Next Week: By early next week, a Pacific trough will introduce an unsettled weather pattern across the Pacific Northwest, eventually progressing into central Idaho and western Montana. Considerable spread remains among deterministic models regarding the finer synoptic details. Current ensemble cluster analysis for Monday indicates a 61% probability of a slower, milder progression, while the remaining 39% of members favor a faster, cooler, and wetter solution.

This trough is expected to eventually cut off and meander over the region, maintaining showery conditions through mid-week. Those with outdoor plans next week should monitor the forecast closely and be prepared with rain gear in the event the wetter solutions materialize.

AVIATION

Predominantly VFR conditions will prevail across all regional terminals through Friday. Diurnal cumulus development will be common over the higher terrain both this afternoon and Friday afternoon, while valleys remain mostly clear to partly cloudy. Isolated showers are expected near the Continental Divide this afternoon, with shower activity expanding into northwest Montana by Friday afternoon. Sufficient instability may support an isolated thunderstorm near Glacier National Park on Friday afternoon. Expect localized wind gusts of 20-25 knots near any thunderstorm or stronger shower activity. Otherwise, light and diurnally driven winds will continue at all terminal sites.

MSO WATCHES/WARNINGS/ADVISORIES

MT...None. ID...None.