Alert archive / Montana / High Wind Warnings in 2021

High Wind Warning 4, NWS Missoula, MT

September 17, 2021Lemhi County, Idaho; 4 counties in Montana

NWS Missoula, MT issued this high wind warning at Sep 17, 2021, 2:16 PM MDT for Lemhi County, Idaho; 4 counties in Montana. It took effect at Sep 18, 2021, 9:00 AM MDT. It was in force for 12 hr. 16 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Sep 17, 2021, 2:16 PM MDT (20:16 UTC)
In effect from
Sep 18, 2021, 9:00 AM MDT
Expired
Sep 18, 2021, 9:00 PM MDT
In force
12 hr
Issued by
NWS Missoula, MT

Counties Lemhi County, ID, Deer Lodge County, MT, Granite County, MT, Powell County, MT, Silver Bow County, MT

The radar

The Missoula radar (KMSX), 127 km from the middle of the area, began a volume at 20:14 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.

What was reported inside it

TimeReportWhereRemark
Sep 18, 11:46 AM MDTNON-TSTM WND GST 403 Sse Butte, MTASOS STATION KBTM BUTTE-MOONEY AP.
Sep 18, 12:11 PM MDTNON-TSTM WND GST 52Macdonald Pass, MTCORRECTS PREVIOUS NON-TSTM WND GST REPORT FROM MTMDP. MACDONALD PASS US-12 MP 27.9, MT. MTMDP (MT DOT) MEASURED 37G52 MPH AT 12:11 AND 12:15 PM MDT.
Sep 18, 12:11 PM MDTNON-TSTM WND GST 52Mtmdp, MTMACDONALD PASS US-12 MP 27.9, MT. MTMDP (MT DOT) ELEV: 6325 FT.; LAT/LON: 46.56148/-112.30931 WINDS OF 37G52 MPH OBSERVED AT 12:11 AND 12:15 PM MDT.
Sep 18, 12:11 PM MDTNON-TSTM WND GST 52Mtmdp, MTMACDONALD PASS US-12 MP 27.9, MT. MTMDP (MT DOT) MEASURED 37G52 MPH AT 12:11 AND 12:15 PM MDT.
Sep 18, 12:15 PM MDTNON-TSTM WND GST 52Macdonald Pass, MTMACDONALD PASS HWY 12 SENSOR.
Sep 18, 12:26 PM MDTNON-TSTM WND GST 4111 N Ellis, IDMESONET STATION EZRI1 EZRA CREEK.
Sep 18, 1:26 PM MDTNON-TSTM WND GST 4611 N Ellis, IDMESONET STATION EZRI1 EZRA CREEK.
Sep 18, 2:35 PM MDTNON-TSTM WND GST 404 S Salmon, IDKSMN AIRPORT AWOS.
Sep 18, 2:50 PM MDTNON-TSTM WND GST 443 Sw Salmon, IDSALMON RAWS.
Sep 18, 3:53 PM MDTNON-TSTM WND GST 513 Nne Newcomb, MT
Sep 18, 4:51 PM MDTNON-TSTM WND GST 566 Se North Fork, IDMESONET STATION KRCI1 KRILEY CREEK RAWS.
Sep 18, 5:51 PM MDTNON-TSTM WND GST 606 Se North Fork, IDMESONET STATION KRCI1 KRILEY CREEK RAWS.
Sep 18, 6:00 PM MDTNON-TSTM WND GST 492 Wsw Deer Lodge, MTMESONET STATION K38S 1.8 W DEER LODGE (GTFWFO).
Sep 18, 6:08 PM MDTNON-TSTM WND GST 51Avon North Mt Hwy 141 M, MTOBSERVATION FROM MESOWEST SITE: AVON NORTH MT-141 MP 8.1, MT. MTAVN (MT DOT). ELEV: 5085 FT.; LAT/LON: 46.69679/-112.65944 LOCATION FOR THIS LSR ESTIMATED FROM MESOWEST MAP.
Sep 18, 6:48 PM MDTNON-TSTM WND GST 486 E Yellowjacket, IDMESONET STATION BAEI1 RED ROCK PEAK.
Sep 18, 6:51 PM MDTNON-TSTM WND GST 4311 Wsw Shoup, IDMESONET STATION SKFI1 SKULL GULCH.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 8.3 hours before the alert went out and 254 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.

Skew-T log-pSkew-T log-p diagram, Great_falls, MT at 12:00Z on 2021-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 12:00Z on 2021-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2562 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

691 
WWUS75 KMSO 172016
NPWMSO

URGENT - WEATHER MESSAGE
National Weather Service Missoula MT
216 PM MDT Fri Sep 17 2021

MTZ007-190300-
/O.NEW.KMSO.HW.W.0004.210918T1500Z-210919T0300Z/
Butte/Blackfoot Region-
216 PM MDT Fri Sep 17 2021

...HIGH WIND WARNING IN EFFECT FROM 9 AM TO 9 PM MDT SATURDAY...

* WHAT...West winds 25 to 35 mph with gusts up to 55 mph 
  expected.

* WHERE...Butte, Georgetown Lake, Highway 12 Garrison to 
  Elliston, Homestake Pass, and MacDonald Pass.

* WHEN...From 9 AM to 9 PM MDT Saturday.

* IMPACTS...Damaging winds will blow down trees and power lines. 
  Widespread power outages are expected. Travel will be 
  difficult, especially for high profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should avoid being outside in forested areas and around
trees and branches. Fasten loose objects or shelter objects in 
a safe location prior to the onset of winds. Use caution if you 
must drive.

&&

$$

IDZ009-010-190300-
/O.NEW.KMSO.HW.W.0004.210918T1500Z-210919T0300Z/
Western Lemhi County-Eastern Lemhi County-
216 PM MDT Fri Sep 17 2021

...HIGH WIND WARNING IN EFFECT FROM 9 AM TO 9 PM MDT SATURDAY...

* WHAT...Southwest winds 25 to 35 mph with gusts up to 55 mph 
  expected.

* WHERE...Shoup, Bannock Pass, Highway 28 Tendoy to Lone Pine, 
  Highway 93 Lost Trail Pass to Gibbonsville, Lemhi Pass, and 
  Salmon.

* WHEN...From 9 AM to 9 PM MDT Saturday.

* IMPACTS...Damaging winds will blow down trees and power lines. 
  Widespread power outages are expected. Travel will be 
  difficult, especially for high profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should avoid being outside in forested areas and around
trees and branches. Fasten loose objects or shelter objects in 
a safe location prior to the onset of winds. Use caution if you 
must drive.

&&

$$

MTZ006-043-190300-
/O.NEW.KMSO.WI.Y.0008.210918T1500Z-210919T0300Z/
Bitterroot/Sapphire Mountains-Potomac/Seeley Lake Region-
216 PM MDT Fri Sep 17 2021

...WIND ADVISORY IN EFFECT FROM 9 AM TO 9 PM MDT SATURDAY...

* WHAT...West winds 20 to 30 mph with gusts up to 45 mph 
  expected.

* WHERE...Highway 93 Sula to Lost Trail Pass, Lolo Pass, Highway 
  200 Bonner to Greenough, Highway 83 Seeley Lake to Condon, and 
  I- 90 East Missoula to Bearmouth.

* WHEN...From 9 AM to 9 PM MDT Saturday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

MTZ005-190300-
/O.NEW.KMSO.WI.Y.0008.210918T1500Z-210919T0300Z/
Missoula/Bitterroot Valleys-
216 PM MDT Fri Sep 17 2021

...WIND ADVISORY IN EFFECT FROM 9 AM TO 9 PM MDT SATURDAY...

* WHAT...West winds 20 to 30 mph with gusts up to 45 mph 
  expected.

* WHERE...Missoula/Bitterroot Valleys.

* WHEN...From 9 AM to 9 PM MDT Saturday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

MTZ003-190300-
/O.NEW.KMSO.LW.Y.0006.210918T1500Z-210919T0300Z/
Flathead/Mission Valleys-
216 PM MDT Fri Sep 17 2021

...LAKE WIND ADVISORY IN EFFECT FROM 9 AM TO 9 PM MDT SATURDAY
FOR FLATHEAD LAKE...

* WHAT...Waves 1 to 3 feet due to southwest to west winds 10 to 
  20 mph with gusts up to 35 mph expected on Flathead Lake.

* WHERE...Flathead/Mission Valleys.

* WHEN...From 9 AM to 9 PM MDT Saturday.

* IMPACTS...Strong winds and rough waves will create hazardous 
  conditions for small craft.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters on area lakes should use extra caution since strong winds
and rough waves can overturn small craft.

&&

$$
1 follow-up statement
461 
WWUS75 KMSO 190239
NPWMSO

URGENT - WEATHER MESSAGE
National Weather Service Missoula MT
839 PM MDT Sat Sep 18 2021

MTZ007-190345-
/O.EXP.KMSO.HW.W.0004.000000T0000Z-210919T0300Z/
Butte/Blackfoot Region-
839 PM MDT Sat Sep 18 2021

...HIGH WIND WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING...

Gusts of 20-30 mph will continue until about midnight MDT.

$$

IDZ009-010-190345-
/O.EXP.KMSO.HW.W.0004.000000T0000Z-210919T0300Z/
Western Lemhi County-Eastern Lemhi County-
839 PM MDT Sat Sep 18 2021

...HIGH WIND WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING...

Gusts of 20-30 mph will continue until about midnight MDT.

$$

MTZ006-043-190345-
/O.EXP.KMSO.WI.Y.0008.000000T0000Z-210919T0300Z/
Bitterroot/Sapphire Mountains-Potomac/Seeley Lake Region-
839 PM MDT Sat Sep 18 2021

...WIND ADVISORY WILL EXPIRE AT 9 PM MDT THIS EVENING...


$$

MTZ005-190345-
/O.EXP.KMSO.WI.Y.0008.000000T0000Z-210919T0300Z/
Missoula/Bitterroot Valleys-
839 PM MDT Sat Sep 18 2021

...WIND ADVISORY WILL EXPIRE AT 9 PM MDT THIS EVENING...


$$

MTZ003-190345-
/O.EXP.KMSO.LW.Y.0006.000000T0000Z-210919T0300Z/
Flathead/Mission Valleys-
839 PM MDT Sat Sep 18 2021

...LAKE WIND ADVISORY WILL EXPIRE AT 9 PM MDT THIS EVENING FOR
FLATHEAD LAKE...


$$

The office that day

Everything else NWS Missoula, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 16, 7:41 PM MDTFrost AdvisoryMSOFlathead, Lake, Missoula, Ravalli, Sanders13 hr
Sep 17, 2:16 PM MDTLake Wind AdvisoryMSOFlathead, Lake, Sanders31 hr
Sep 17, 2:16 PM MDTWind AdvisoryMSOGranite, Lake, Missoula, Powell, Ravalli31 hr

Nearby

High Wind Warnings in Montana, 2021High Wind Warnings in Idaho, 2021Every high wind warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.