Alert archive / Montana / Wind Advisories in 2021

Wind Advisory 8, NWS Missoula, MT

September 17, 20215 counties in Montana

NWS Missoula, MT issued this wind advisory at Sep 17, 2021, 2:16 PM MDT for 5 counties in Montana. It took effect at Sep 18, 2021, 9:00 AM MDT. It was in force for 12 hr.

The area

The counties it named.

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 Granite County, MT, Lake County, MT, Missoula County, MT, Powell County, MT, Ravalli County, MT

The radar

The Missoula radar (KMSX), 34 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.

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 8.3 hours before the alert went out and 227 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, Spokane, WA 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, Spokane, WA at 12:00Z on 2021-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 178 square meters per square second.1939587897Sfc1 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
2875 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
178 m²/s²
0-3 km storm-relative helicity
357 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 MDTHigh Wind WarningMSODeer Lodge, Granite, Powell, Silver Bow31 hr
Sep 17, 2:16 PM MDTLake Wind AdvisoryMSOFlathead, Lake, Sanders31 hr

Nearby

Wind Advisories in Montana, 2021Every wind advisory 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.