Alert archive / Idaho / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 4, NWS Missoula, MT
NWS Missoula, MT issued this severe thunderstorm warning at May 28, 2026, 5:09 PM PDT for Idaho County, Idaho. It was in force for 31 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- May 28, 2026, 5:09 PM PDT (00:09 UTC)
- Expired
- May 28, 2026, 5:40 PM PDT
- In force
- 31 min
- Issued by
- NWS Missoula, MT
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County Idaho County, ID
The radar
The Missoula radar (KMSX), 184 km from the middle of the area, began a volume at 00:08 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 28, 3:21 PM PDT | Severe Thunderstorm Watch | SPC | 9 hr |
The nearest sounding before it
Spokane, WA (KOTX), launched 00:00Z, 0.2 hours before the alert went out and 198 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1168 J/kg
- Mixed-layer CIN
- -53 J/kg
- Mixed-layer LCL
- 2331 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- -3 m²/s²
- 0-3 km storm-relative helicity
- 9 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.2
The text
As transmitted.
735
WUUS55 KMSO 290009
SVRMSO
IDC049-290100-
/O.NEW.KMSO.SV.W.0004.260529T0009Z-260529T0100Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Missoula MT
609 PM MDT Thu May 28 2026
The National Weather Service in Missoula has issued a
* Severe Thunderstorm Warning for...
Central Idaho County in central Idaho...
* Until 700 PM MDT /600 PM PDT/.
* At 609 PM MDT /509 PM PDT/, a severe thunderstorm was located 19
miles southeast of Kooskia, or 15 miles east of Grangeville, moving
north at 25 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
* Locations impacted include...
Kooskia, Clearwater, Stites, Harpster, Syringa and Winona.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds and large
hail.
Torrential rainfall is also occurring with this storm and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4584 11568 4582 11597 4614 11613 4618 11563
TIME...MOT...LOC 0008Z 179DEG 19KT 4588 11581
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$2 follow-up statements
548
WWUS55 KMSO 290027
SVSMSO
Severe Weather Statement
National Weather Service Missoula MT
627 PM MDT Thu May 28 2026
IDC049-290100-
/O.CON.KMSO.SV.W.0004.000000T0000Z-260529T0100Z/
Idaho ID-
627 PM MDT Thu May 28 2026 /527 PM PDT Thu May 28 2026/
...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 7 PM MDT /6 PM
PDT/ FOR NORTHWESTERN IDAHO COUNTY...
At 627 PM MDT /527 PM PDT/, a severe thunderstorm was located 13
miles southeast of Kooskia, or 15 miles east of Grangeville, moving
north at 25 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Kooskia, Clearwater, Stites, Harpster, Syringa and Winona.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds and large
hail.
Torrential rainfall is also occurring with this storm and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4593 11570 4590 11601 4614 11613 4618 11563
TIME...MOT...LOC 0009Z 179DEG 19KT 4589 11581
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$037 WWUS55 KMSO 290040 SVSMSO Severe Weather Statement National Weather Service Missoula MT 640 PM MDT Thu May 28 2026 IDC049-290050- /O.CAN.KMSO.SV.W.0004.000000T0000Z-260529T0100Z/ Idaho ID- 640 PM MDT Thu May 28 2026 /540 PM PDT Thu May 28 2026/ ...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR NORTHWESTERN IDAHO COUNTY... The thunderstorm has moved out of the warning area. However, small hail, gusty winds, and heavy rain are still possible with this thunderstorm. A Severe Thunderstorm Watch remains in effect until 100 AM MDT /1200 AM PDT/ Friday for a portion of central Idaho. && LAT...LON 4593 11570 4590 11601 4614 11613 4618 11563 TIME...MOT...LOC 0027Z 179DEG 19KT 4598 11582 $$
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Missoula, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at May 28, 12:57 PM PDT, 4 hours 12 minutes earlier.
Area forecast discussion, May 28, 12:57 PM PDT, 4 hours 12 minutes before
Area Forecast Discussion National Weather Service Missoula MT 157 PM MDT Thu May 28 2026 .DISCUSSION... KEY MESSAGES: - Warm temperatures and showers/thunderstorms with a few strong storms this afternoon, especially across northwest Montana and through north central Idaho - Prolonged heavy rainfall this weekend in western Montana, elevating risks for hydrologic responses and rockfalls especially near and along the Continental Divide. - High elevation snowfall on Saturday night into Monday could create difficult backcountry conditions. This Afternoon/Evening: This afternoon will bring the warmest temperatures of the week, with valley highs climbing into the upper 80s to near 90 degrees across western Montana and north-central Idaho. Similar to yesterday, thunderstorms will develop by early afternoon and track northwestward. Activity will focus primarily from the Bitterroot Valley northward and across north-central Idaho, including the Camas Prairie. A few stronger storms could produce erratic wind gusts, brief heavy downpours, and small hail. Meanwhile, elevated fire weather concerns persist across southwest Montana this afternoon, particularly south of Dillon due to gusty winds and relative humidity dropping into the teens. Friday: The weather pattern shifts significantly on Friday as an incoming Pacific low-pressure system brings a band of heavy rain. South to north moving showers and storms will bring localized heavy rain and the potential for gusty winds and hail once again. Storms may train over parts of the region particularly the US-12 and US-95 corridors in Idaho, thus localized flash flooding is a concern. Saturday through Monday: By Saturday, the low-pressure system is projected to settle near the Yellowstone region, placing western Montana within a robust deformation zone. Tapping into anomalous moisture, this setup will trigger a prolonged, highly efficient rainfall event into at least Monday. - Hydrologic & Terrain Impacts: Saturated soils from recent rains combined with ongoing high-elevation snowmelt will elevate the risk for significant rises on rivers and streams, as well as rockfalls in steep canyon terrain. - Precipitation Totals: The heaviest totals are forecast near the Continental Divide, where there is a 70 to 90 percent chance of exceeding 1 inch of rain, with localized amounts of 2 to 4 inches possible. - Snow Levels & Backcountry: Sharp cooling aloft will cause snow levels to drop to around 6,000 feet along the Continental Divide by Sunday morning. Backcountry users should prepare for raw, winter-like conditions and difficult travel. Extended Outlook: Looking further ahead, ensemble clusters favor a quick transition back to building high pressure and above- normal temperatures by mid-next week, offering a reprieve from this weekend's wet pattern. && .AVIATION...VFR conditions will prevail across western Montana and north-central Idaho terminals this afternoon, though valley temperatures approaching 90F will contribute to elevated density altitude. Scattered afternoon and evening thunderstorms will focus from the Bitterroot Valley northward and across north-central Idaho, with high-resolution models maintaining coverage trends similar to yesterday. Any developing convective cells could produce short- lived, localized MVFR/IFR conditions due to heavy downpours and low ceilings, alongside erratic outflow wind gusts, hail, and mountain obscurations. Outside of convective activity, terminals in southwest Montana and Lemhi County (including KBTM and KSMN) will experience breezy southeasterly surface winds this afternoon. Patchy fog and low stratus may develop Friday morning in areas that receive rain this evening, ahead of another widespread round of showers and thunderstorms Friday afternoon. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. &&
In the hours before
Special weather statement, May 28, 4:42 PM PDT, 27 minutes before
Special Weather Statement
National Weather Service Missoula MT
542 PM MDT Thu May 28 2026
IDZ006>008-290015-
Southern Clearwater Mountains ID-Lower Hells Canyon/Salmon River
Region ID-Orofino/Grangeville Region ID-
442 PM PDT Thu May 28 2026
...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL IDAHO COUNTY UNTIL
515 PM PDT...
At 442 PM PDT, Doppler radar was tracking a strong thunderstorm 22
miles southeast of Grangeville, moving northwest at 15 mph.
HAZARD...Wind gusts up to 40 mph and half inch size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Grangeville, White Bird, Cottonwood, Fenn, Copperville, Canfield
and Keuterville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Monitor the weather situation closely and be alert for threatening
weather conditions.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
Torrential rainfall is also occurring with this storm and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4600 11653 4604 11652 4613 11651 4612 11648
4614 11648 4616 11647 4576 11564 4560 11578
4586 11679 4587 11675 4589 11673 4594 11676
4596 11675 4600 11670 4600 11665 4603 11665
4603 11660 4600 11654
TIME...MOT...LOC 2342Z 122DEG 13KT 4571 11577
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPHSpecial weather statement, May 28, 4:47 PM PDT, 22 minutes before
Special Weather Statement
National Weather Service Missoula MT
547 PM MDT Thu May 28 2026
MTZ005-043-290015-
Missoula/Bitterroot Valleys MT-Potomac/Seeley Lake Region MT-
547 PM MDT Thu May 28 2026
...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN MISSOULA COUNTY
UNTIL 615 PM MDT...
At 547 PM MDT, Doppler radar was tracking a strong thunderstorm near
Bonner-West Riverside, or 10 miles east of Missoula, moving north at
15 mph.
HAZARD...Wind gusts up to 50 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Bonner-West Riverside, East Missoula, Evaro and Twin Creeks.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Monitor the weather situation closely and be alert for threatening
weather conditions.
Torrential rainfall is also occurring with this storm and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4699 11399 4709 11402 4712 11399 4713 11362
4684 11372 4685 11389 4685 11394
TIME...MOT...LOC 2347Z 181DEG 13KT 4689 11381
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPHSpecial weather statement, May 28, 4:51 PM PDT, 18 minutes before
Special Weather Statement
National Weather Service Missoula MT
551 PM MDT Thu May 28 2026
MTZ003-290015-
Flathead/Mission Valleys MT-
551 PM MDT Thu May 28 2026
...A STRONG THUNDERSTORM WILL IMPACT NORTHERN LAKE AND CENTRAL
FLATHEAD COUNTIES UNTIL 615 PM MDT...
At 551 PM MDT, Doppler radar was tracking a strong thunderstorm over
Bigfork, or 13 miles southeast of Kalispell, moving northwest at 20
mph.
HAZARD...Wind gusts up to 40 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Bigfork and Somers.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Monitor the weather situation closely and be alert for threatening
weather conditions.
&&
LAT...LON 4805 11404 4804 11405 4803 11405 4802 11406
4802 11408 4801 11407 4799 11412 4814 11433
4819 11412
TIME...MOT...LOC 2351Z 157DEG 16KT 4806 11412
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPHSpecial weather statement, May 28, 5:03 PM PDT, 6 minutes before
Special Weather Statement
National Weather Service Missoula MT
603 PM MDT Thu May 28 2026
IDZ005>007-290030-
Southern Clearwater Mountains ID-Northern Clearwater Mountains ID-
Orofino/Grangeville Region ID-
503 PM PDT Thu May 28 2026
...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL IDAHO AND SOUTH
CENTRAL CLEARWATER COUNTIES UNTIL 530 PM PDT...
At 503 PM PDT, Doppler radar was tracking a strong thunderstorm 6
miles north of Lowell, or 32 miles northeast of Grangeville, moving
northwest at 20 mph.
HAZARD...Wind gusts up to 40 mph and half inch size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Pierce, Weippe, Musselshell and Glenwood.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Monitor the weather situation closely and be alert for threatening
weather conditions.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
Torrential rainfall is also occurring with this storm and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4644 11589 4654 11573 4624 11547 4613 11568
4635 11605
TIME...MOT...LOC 0003Z 143DEG 19KT 4622 11562
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPHSpecial weather statement, May 28, 5:04 PM PDT, 5 minutes before
Special Weather Statement
National Weather Service Missoula MT
604 PM MDT Thu May 28 2026
IDZ006-007-290030-
Southern Clearwater Mountains ID-Orofino/Grangeville Region ID-
504 PM PDT Thu May 28 2026
...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL IDAHO COUNTY UNTIL
530 PM PDT...
At 504 PM PDT, Doppler radar was tracking a strong thunderstorm 19
miles southeast of Kooskia, or 15 miles east of Grangeville, moving
north at 25 mph.
HAZARD...Wind gusts up to 40 mph and half inch size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Clearwater, Stites, Harpster and Syringa.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Monitor the weather situation closely and be alert for threatening
weather conditions.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
Torrential rainfall is also occurring with this storm and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4590 11602 4608 11630 4617 11565 4585 11568
4584 11594
TIME...MOT...LOC 0003Z 176DEG 23KT 4589 11581
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPHSpecial weather statement, May 28, 5:05 PM PDT, 4 minutes before
Special Weather Statement
National Weather Service Missoula MT
605 PM MDT Thu May 28 2026
MTZ003-290030-
Flathead/Mission Valleys MT-
605 PM MDT Thu May 28 2026
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL FLATHEAD COUNTY UNTIL
630 PM MDT...
At 605 PM MDT, Doppler radar was tracking a strong thunderstorm over
Evergreen, moving northwest at 20 mph.
HAZARD...Wind gusts up to 40 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Kalispell and Evergreen.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Monitor the weather situation closely and be alert for threatening
weather conditions.
&&
LAT...LON 4825 11417 4821 11425 4826 11447 4836 11430
TIME...MOT...LOC 0005Z 131DEG 17KT 4823 11425
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPHThe office that day
Everything else NWS Missoula, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 28, 5:03 PM PDT | Special Weather Statement | MSO | Clearwater | 27 min |
| May 28, 5:04 PM PDT | Special Weather Statement | MSO | Idaho | 26 min |
| May 28, 5:38 PM PDT | Severe Thunderstorm Warning | MSO | Clearwater | 52 min |
| May 28, 5:47 PM PDT | Severe Thunderstorm Warning | MSO | Clearwater, Idaho | 34 min |
| May 28, 6:22 PM PDT | Special Weather Statement | MSO | Clearwater | 23 min |
| May 28, 6:35 PM PDT | Severe Thunderstorm Warning | MSO | Clearwater | 30 min |
Nearby
Severe Thunderstorm Warnings in Idaho, 2026Every severe thunderstorm warning in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.