Yellowstone National Park, Wyoming
Regional Weather Alerts
| Alert: | Winter Weather Advisory |
| Area(s): | Little Belt and Highwood Mountains; Big Belt, Bridger and Castle Mountains |
| Effective: | 2026-05-17 @ 6:55 am -> 2026-05-17 @ 10:00 pm |
| Onset: | 2026-05-17 @ 6:55 am -> 2026-05-18 @ 1:00 am |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Great Falls MT on 2026-05-17 @ 6:55 am |
| Headline: | Winter Weather Advisory issued May 17 at 5:55AM MDT until May 18 at 12:00AM MDT by NWS Great Falls MT |
| Description: |
* WHAT...Snow. Additional snow accumulations up to 5 inches. Winds gusting as high as 40 mph. * WHERE...Big Belt, Bridger and Castle Mountains and Little Belt and Highwood Mountains. * WHEN...Until midnight MDT tonight. * IMPACTS...Plan on slippery backcountry road conditions. Wet and raw conditions may create hypothermia risk for those recreating in the backcountry. |
| Alert: | Winter Weather Advisory |
| Area(s): | East Glacier Park Region; Southern Rocky Mountain Front; Upper Blackfoot and MacDonald Pass; Elkhorn and Boulder Mountains |
| Effective: | 2026-05-17 @ 6:55 am -> 2026-05-17 @ 10:00 pm |
| Onset: | 2026-05-17 @ 6:55 am -> 2026-05-18 @ 1:00 am |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Great Falls MT on 2026-05-17 @ 6:55 am |
| Headline: | Winter Weather Advisory issued May 17 at 5:55AM MDT until May 18 at 12:00AM MDT by NWS Great Falls MT |
| Description: |
* WHAT...Snow. Additional snow accumulations up to 4 inches. Winds gusting as high as 40 mph. * WHERE...The Continental Divide along the Rocky Mountain Front, Upper Blackfoot and MacDonald Pass, and Elkhorn and Boulder Mountains. * WHEN...Until midnight MDT tonight. * IMPACTS...Plan on slippery backcountry road conditions. Wet and raw conditions may create hypothermia risk for those recreating in the backcountry. |
| Alert: | Lake Wind Advisory |
| Area(s): | Central and Southeast Phillips; Central and Southern Valley; Petroleum; Garfield; McCone |
| Effective: | 2026-05-17 @ 3:04 am -> 2026-05-17 @ 4:00 pm |
| Onset: | 2026-05-17 @ 3:04 am -> 2026-05-18 @ 1:00 am |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Glasgow MT on 2026-05-17 @ 3:04 am |
| Headline: | Lake Wind Advisory issued May 17 at 2:04AM MDT until May 18 at 12:00AM MDT by NWS Glasgow MT |
| Description: |
* WHAT...Northwest winds 15 to 25 mph with gusts up to 40 mph. * WHERE...Fort Peck Lake. * WHEN...Until midnight MDT tonight. * IMPACTS...Strong winds and rough waves on area lakes will create hazardous conditions for small craft. |
| Alert: | Winter Weather Advisory |
| Area(s): | Red Lodge Foothills; Beartooth Foothills |
| Effective: | 2026-05-17 @ 2:04 am -> 2026-05-18 @ 2:15 am |
| Onset: | 2026-05-17 @ 7:00 pm -> 2026-05-18 @ 1:00 pm |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Billings MT on 2026-05-17 @ 2:04 am |
| Headline: | Winter Weather Advisory issued May 17 at 1:04AM MDT until May 18 at 12:00PM MDT by NWS Billings MT |
| Description: |
* WHAT...Snow and blowing snow expected. Total snow accumulations up to 4 inches. Winds gusting as high as 40 mph. * WHERE...Beartooth Foothills and Red Lodge Foothills. * WHEN...From 6 PM this evening to noon MDT Monday. * IMPACTS...Plan on difficult driving conditions due to poor visibility and slick roads. The hazardous conditions will impact the Monday morning commute. * ADDITIONAL DETAILS...The greatest snow accumulations will occur along the higher foothills near the mountains. |
| Alert: | Winter Weather Advisory |
| Area(s): | Pryor/Northern Bighorn Mountains; Northeast Bighorn Mountains |
| Effective: | 2026-05-17 @ 2:04 am -> 2026-05-18 @ 2:15 am |
| Onset: | 2026-05-17 @ 7:00 pm -> 2026-05-18 @ 1:00 pm |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Billings MT on 2026-05-17 @ 2:04 am |
| Headline: | Winter Weather Advisory issued May 17 at 1:04AM MDT until May 18 at 12:00PM MDT by NWS Billings MT |
| Description: |
* WHAT...Snow and blowing snow expected. Total snow accumulations between 5 and 10 inches. Winds gusting as high as 45 mph. * WHERE...In Montana, Pryor/Northern Bighorn Mountains. In Wyoming, Northeast Bighorn Mountains. * WHEN...From 6 PM this evening to noon MDT Monday. * IMPACTS...Snow and blowing snow will impact back country recreation and travel along Highway 14 through the Bighorn Mountains. * ADDITIONAL DETAILS...Back country activities will be impacted by difficult winter conditions. |
| Alert: | Frost Advisory |
| Area(s): | Flathead/Mission Valleys; Missoula/Bitterroot Valleys |
| Effective: | 2026-05-16 @ 9:31 am -> 2026-05-17 @ 9:45 am |
| Onset: | 2026-05-16 @ 9:00 pm -> 2026-05-17 @ 10:00 am |
| Severity: | Minor |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-05-16 @ 9:31 am |
| Headline: | Frost Advisory issued May 16 at 8:31AM MDT until May 17 at 9:00AM MDT by NWS Missoula MT |
| Description: |
* WHAT...For the first Frost Advisory, temperatures as low as 32 will result in frost formation. For the second Frost Advisory, temperatures as low as 30 will result in frost formation. * WHERE...Flathead/Mission Valleys and Missoula/Bitterroot Valleys. * WHEN...For the first Frost Advisory, from 8 PM this evening to 9 AM MDT Sunday. For the second Frost Advisory, from 8 PM Sunday to 9 AM MDT Monday. * IMPACTS...Frost could harm sensitive outdoor vegetation. |
| Alert: | Frost Advisory |
| Area(s): | Flathead/Mission Valleys; Missoula/Bitterroot Valleys |
| Effective: | 2026-05-16 @ 9:31 am -> 2026-05-17 @ 9:45 am |
| Onset: | 2026-05-17 @ 9:00 pm -> 2026-05-18 @ 10:00 am |
| Severity: | Minor |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-05-16 @ 9:31 am |
| Headline: | Frost Advisory issued May 16 at 8:31AM MDT until May 18 at 9:00AM MDT by NWS Missoula MT |
| Description: |
* WHAT...For the first Frost Advisory, temperatures as low as 32 will result in frost formation. For the second Frost Advisory, temperatures as low as 30 will result in frost formation. * WHERE...Flathead/Mission Valleys and Missoula/Bitterroot Valleys. * WHEN...For the first Frost Advisory, from 8 PM this evening to 9 AM MDT Sunday. For the second Frost Advisory, from 8 PM Sunday to 9 AM MDT Monday. * IMPACTS...Frost could harm sensitive outdoor vegetation. |
| Alert: | Winter Weather Advisory |
| Area(s): | Bitterroot/Sapphire Mountains; Butte/Blackfoot Region |
| Effective: | 2026-05-15 @ 12:38 pm -> 2026-05-18 @ 1:00 am |
| Onset: | 2026-05-17 @ 1:00 am -> 2026-05-18 @ 1:00 am |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-05-15 @ 12:38 pm |
| Headline: | Winter Weather Advisory issued May 15 at 11:38AM MDT until May 18 at 12:00AM MDT by NWS Missoula MT |
| Description: |
* WHAT...Snow expected. Total snow accumulations of 2 to 6 inches in the mountain terrain above 5000 feet. Slushy accumulations possible for Lost Trail, Homestake and MacDonald Passes and around Georgetown Lake. Winds gusting as high as 35 mph. * WHERE...Homestake Pass, Lolo Pass, Georgetown Lake, MacDonald Pass, Highway 93 Sula to Lost Trail Pass, and Butte. * WHEN...From midnight Saturday Night to midnight MDT Sunday Night. * IMPACTS...Plan on slippery backcountry road conditions. Cold, wet and breezy conditions may create hypothermia risk for those recreating in the backcountry. |
| Alert: | Winter Weather Advisory |
| Area(s): | West Glacier Region; Potomac/Seeley Lake Region |
| Effective: | 2026-05-15 @ 12:38 pm -> 2026-05-18 @ 1:00 am |
| Onset: | 2026-05-17 @ 1:00 am -> 2026-05-18 @ 1:00 am |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-05-15 @ 12:38 pm |
| Headline: | Winter Weather Advisory issued May 15 at 11:38AM MDT until May 18 at 12:00AM MDT by NWS Missoula MT |
| Description: |
* WHAT...Snow expected. Total snow accumulations of 2 to 6 inches in the mountain terrain above 5000 feet. Slushy accumulations possible on Marias Pass. * WHERE...The higher terrain of Glacier National Park. * WHEN...From midnight Saturday Night to midnight MDT Sunday Night. * IMPACTS...Plan on slippery backcountry road conditions. Cold, wet and breezy conditions may create hypothermia risk for those recreating in the backcountry. |