Yellowstone National Park, Wyoming
Regional Weather Alerts
| Alert: | Flood Advisory |
| Area(s): | Chouteau, MT |
| Effective: | 2026-09-06 @ 9:02 pm -> 2026-09-07 @ 12:00 am |
| Onset: | 2026-09-06 @ 9:02 pm -> 2026-09-07 @ 12:00 am |
| Severity: | Minor |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Great Falls MT on 2026-09-06 @ 9:02 pm |
| Headline: | Flood Advisory issued September 6 at 8:02PM MDT until September 6 at 11:00PM MDT by NWS Great Falls MT |
| Description: |
* WHAT...Flooding caused by excessive rainfall is expected. * WHERE...Southeastern Chouteau County in north central Montana... * WHEN...Until 1100 PM MDT. * IMPACTS...Minor flooding in low-lying and poor drainage areas. * ADDITIONAL DETAILS... - At 801 PM MDT, Doppler radar indicated heavy rain due to thunderstorms. Minor flooding is ongoing or expected to begin shortly in the advisory area. Between 0.5 and 1 inch of rain has fallen. - Additional rainfall amounts up to 0.5 inches are expected over the area. This additional rain will result in minor flooding. - Some locations that will experience flooding include... Geraldine, Square Butte and Iliad. - http://www.weather.gov/safety/flood |
| Alert: | Severe Thunderstorm Warning |
| Area(s): | Chouteau, MT |
| Effective: | 2026-09-06 @ 8:54 pm -> 2026-09-06 @ 9:45 pm |
| Onset: | 2026-09-06 @ 8:54 pm -> 2026-09-06 @ 9:45 pm |
| Severity: | Severe |
| Certainty: | Observed |
| Urgency: | Immediate |
| Issued By: | NWS Great Falls MT on 2026-09-06 @ 8:54 pm |
| Headline: | Severe Thunderstorm Warning issued September 6 at 7:54PM MDT until September 6 at 8:45PM MDT by NWS Great Falls MT |
| Description: |
SVRTFX The National Weather Service in Great Falls has issued a * Severe Thunderstorm Warning for... Southeastern Chouteau County in north central Montana... * Until 845 PM MDT. * At 754 PM MDT, a severe thunderstorm was located 19 miles northeast of Geraldine, or 28 miles south of Big Sandy, moving north at 20 mph. HAZARD...Quarter size hail. SOURCE...Radar indicated. IMPACT...Damage to vehicles is expected. * Locations impacted include... Iliad. |
| Alert: | Severe Thunderstorm Warning |
| Area(s): | Judith Basin, MT |
| Effective: | 2026-09-06 @ 8:51 pm -> 2026-09-06 @ 9:30 pm |
| Onset: | 2026-09-06 @ 8:51 pm -> 2026-09-06 @ 9:30 pm |
| Severity: | Severe |
| Certainty: | Observed |
| Urgency: | Immediate |
| Issued By: | NWS Great Falls MT on 2026-09-06 @ 8:51 pm |
| Headline: | Severe Thunderstorm Warning issued September 6 at 7:51PM MDT until September 6 at 8:30PM MDT by NWS Great Falls MT |
| Description: |
At 750 PM MDT, severe thunderstorms were located along a line extending from 13 miles southwest of Stanford to 22 miles south of Geyser to 25 miles southwest of Hobson, moving northeast at 30 mph. HAZARD...Two inch hail and 60 mph wind gusts. SOURCE...Radar indicated. IMPACT...People and animals outdoors will be injured. Expect hail damage to roofs, siding, windows, and vehicles. Expect wind damage to roofs, siding, and trees. Locations impacted include... Stanford, Windham, Moccasin, Ackley Lake State Park, Sapphire Village, Utica, and Benchland. |
| Alert: | Special Weather Statement |
| Area(s): | Cascade County below 5000ft |
| Effective: | 2026-09-06 @ 8:44 pm -> 2026-09-06 @ 9:15 pm |
| Onset: | 2026-09-06 @ 8:44 pm |
| Severity: | Moderate |
| Certainty: | Observed |
| Urgency: | Expected |
| Issued By: | NWS Great Falls MT on 2026-09-06 @ 8:44 pm |
| Headline: | Special Weather Statement issued September 6 at 7:44PM MDT by NWS Great Falls MT |
| Description: |
At 744 PM MDT, Doppler radar was tracking a strong thunderstorm near Cascade, moving northeast at 45 mph. HAZARD...Nickel size hail. SOURCE...Radar indicated. IMPACT...Minor hail damage to vegetation is possible. Locations impacted include... Cascade, Fort Shaw, Ulm, Vaughn, First Peoples Buffalo Jump State Park, and Sun River. |
| Alert: | Severe Thunderstorm Watch |
| Area(s): | Blaine, MT; Broadwater, MT; Cascade, MT; Chouteau, MT; Fergus, MT; Hill, MT; Judith Basin, MT; Lewis and Clark, MT; Liberty, MT; Meagher, MT |
| Effective: | 2026-09-06 @ 6:53 pm -> 2026-09-07 @ 2:00 am |
| Onset: | 2026-09-06 @ 6:53 pm -> 2026-09-07 @ 2:00 am |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Great Falls MT on 2026-09-06 @ 6:53 pm |
| Headline: | Severe Thunderstorm Watch issued September 6 at 5:53PM MDT until September 7 at 1:00AM MDT by NWS Great Falls MT |
| Description: |
THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 662 IN EFFECT UNTIL 1 AM MDT MONDAY FOR THE FOLLOWING AREAS IN MONTANA THIS WATCH INCLUDES 10 COUNTIES IN CENTRAL MONTANA CASCADE FERGUS JUDITH BASIN MEAGHER IN NORTH CENTRAL MONTANA BLAINE CHOUTEAU HILL LIBERTY IN SOUTHWEST MONTANA BROADWATER IN WEST CENTRAL MONTANA LEWIS AND CLARK THIS INCLUDES THE CITIES OF AUGUSTA, BELT, BIG SANDY, CARTER, CASCADE, CHESTER, CHINOOK, DEEP CREEK PASS, FLESHER PASS, FORT BENTON, GRASS RANGE, GREAT FALLS, HARLEM, HAVRE, HAYS, HELENA, HOBSON, KINGS HILL PASS, LEWISTOWN, LEWISTOWN DIVIDE, LINCOLN, MACDONALD PASS, MARTINSDALE, RAYNESFORD, ROCKY BOY, ROGERS PASS, RUDYARD, STANFORD, TOSTON, TOWNSEND, WHITE SULPHUR SPRINGS, WHITLASH, WINIFRED, AND WINSTON. |
| Alert: | Lake Wind Advisory |
| Area(s): | Central and Southeast Phillips; Central and Southern Valley; Petroleum; Garfield; McCone |
| Effective: | 2026-09-06 @ 2:39 pm -> 2026-09-07 @ 1:00 pm |
| Onset: | 2026-09-07 @ 3:00 pm -> 2026-09-09 @ 1:00 am |
| Severity: | Moderate |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Glasgow MT on 2026-09-06 @ 2:39 pm |
| Headline: | Lake Wind Advisory issued September 6 at 1:39PM MDT until September 9 at 12:00AM MDT by NWS Glasgow MT |
| Description: |
* WHAT...West winds 20 to 30 mph with gusts up to 45 mph expected. * WHERE...Fort Peck Lake. * WHEN...From 2 PM Monday to midnight MDT Tuesday Night. * IMPACTS...Strong winds and rough waves on area lakes will create hazardous conditions for small craft. * ADDITIONAL DETAILS...Waves as high as 5 feet. |
| Alert: | Flood Watch |
| Area(s): | East Glacier Park Region; Northern High Plains; Eastern Glacier, Western Toole, and Central Pondera; Eastern Toole and Liberty; Southern Rocky Mountain Front; Southern High Plains; Eastern Pondera and Eastern Teton |
| Effective: | 2026-09-06 @ 12:32 pm -> 2026-09-07 @ 7:15 am |
| Onset: | 2026-09-06 @ 4:00 pm -> 2026-09-08 @ 1:00 pm |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Great Falls MT on 2026-09-06 @ 12:32 pm |
| Headline: | Flood Watch issued September 6 at 11:32AM MDT until September 8 at 12:00PM MDT by NWS Great Falls MT |
| Description: |
* WHAT...Flooding caused by excessive rainfall is possible. * WHERE...A portion of north central Montana, including the following areas, East Glacier Park Region, Eastern Glacier, Western Toole, and Central Pondera, Eastern Pondera and Eastern Teton, Eastern Toole and Liberty, Northern High Plains, Southern High Plains and Southern Rocky Mountain Front. * WHEN...From 3 PM MDT this afternoon through Tuesday morning. * IMPACTS...Excessive runoff may result in minor flooding of creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Flooding may occur in poor drainage areas. Rural gravel and dirt roads can become muddy and may become difficult to travel. Rock/debris slides are possible in the mountains. * ADDITIONAL DETAILS... - Thunderstorms today will be capable of producing 0.50 to 1 inch per hour rain rates. Periods of moderate to heavy rainfall will be possible Monday through Tuesday morning. Widespread 0.75 to 1.5 inches of rain have already fallen along the Rocky Mountain Front over the past 24 hours. Additional widespread rain accumulations of 1 to 3 inches are possible along the Rocky Mountain Front and Sweet Grass Hills with isolated 4 inches possible along and north of US Highway 2 this afternoon through Tuesday morning. - http://www.weather.gov/safety/flood |
| Alert: | Flood Watch |
| Area(s): | West Glacier Region; Flathead/Mission Valleys; Potomac/Seeley Lake Region |
| Effective: | 2026-09-06 @ 10:51 am -> 2026-09-08 @ 1:00 pm |
| Onset: | 2026-09-06 @ 4:00 pm -> 2026-09-08 @ 1:00 pm |
| Severity: | Severe |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Missoula MT on 2026-09-06 @ 10:51 am |
| Headline: | Flood Watch issued September 6 at 9:51AM MDT until September 8 at 12:00PM MDT by NWS Missoula MT |
| Description: |
* WHAT...Flooding caused by excessive rainfall is possible. * WHERE...Portions of northwest and west central Montana, including the following areas, in northwest Montana, Flathead/Mission Valleys and West Glacier Region. In west central Montana, Potomac/Seeley Lake Region. * WHEN...From 3 PM MDT this afternoon through Tuesday morning. * IMPACTS...Excessive runoff may result in flooding of creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. * ADDITIONAL DETAILS... - Thunderstorms capable of rainfall rates of 0.75" to 1.00" per hour are possible this afternoon and evening (Sept 6), which could lead to localized debris flows. This period will then be followed by prolonged moderate to heavy rainfall Monday into Tuesday morning of an additional 1 to 3 inches in the valleys, with 2 to 4 inches in the higher terrain, especially along the Continental Divide and in Glacier National Park. - https://www.weather.gov/mso/hydrology |
| Alert: | Red Flag Warning |
| Area(s): | Eastern Beaverhead National Forest |
| Effective: | 2026-09-05 @ 3:40 pm -> 2026-09-06 @ 10:00 pm |
| Onset: | 2026-09-06 @ 1:00 pm -> 2026-09-06 @ 10:00 pm |
| Severity: | Severe |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-09-05 @ 3:40 pm |
| Headline: | Red Flag Warning issued September 5 at 2:40PM MDT until September 6 at 9:00PM MDT by NWS Missoula MT |
| Description: |
...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TO 9 PM MDT SUNDAY DUE TO WIND AND LOW RELATIVE HUMIDITY FOR EAST BEAVERHEAD... * AFFECTED AREA...Fire Weather Zone 111. * TIMING...From noon to 9 PM MDT Sunday. * WINDS...South winds 15 to 25 mph with gusts up to 40 mph. * RELATIVE HUMIDITY...Relative Humidity between 15 to 25 percent. * IMPACTS...Any fires that develop will spread rapidly. Outdoor burning is not recommended. |
| Alert: | Hydrologic Outlook |
| Area(s): | Flathead, MT; Lake, MT; Missoula, MT |
| Effective: | 2026-09-05 @ 11:43 am -> 2026-09-08 @ 6:00 am |
| Onset: | 2026-09-05 @ 11:43 am |
| Severity: | Unknown |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Missoula MT on 2026-09-05 @ 11:43 am |
| Headline: | Hydrologic Outlook issued September 5 at 10:43AM MDT by NWS Missoula MT |
| Description: |
ESFMSO What: Widespread moderate rainfall over a prolonged period of time. Storm total amounts between 1 to 3 inches for valleys and 2 to 3 inches for the mountains. There is a 10 percent chance of isolated rainfall amounts up to 4 inches along the Continental Divide. Where: Flathead and Lake Counties in northwest Montana, including Glacier National Park. Missoula county in west-central Montana. Timing: Beginning Sunday morning, continuing through Monday night. Heaviest rainfall rates anticipated Monday into Monday night. Significant rainfall totals will bring potential for rapid rises on streams and creeks, rock and debris slides and runoff issues in poor drainage areas. Those recreating in the backcountry should take caution on backcountry roadways for falling debris. |
