Alert archive / Montana / High Wind Watches in 2021

High Wind Watch 3, NWS Missoula, MT

February 20, 20214 counties in Montana

NWS Missoula, MT issued this high wind watch at Feb 20, 2021, 2:56 PM MST for 4 counties in Montana. It took effect at Feb 21, 2021, 5:00 PM MST. It was in force for .

The area

The counties it named.

The facts

Issued
Feb 20, 2021, 2:56 PM MST (21:56 UTC)
In effect from
Feb 21, 2021, 5:00 PM MST
Expired
Feb 21, 2021, 10:42 AM MST
In force
Issued by
NWS Missoula, MT

Counties Flathead County, MT, Lake County, MT, Lincoln County, MT, Sanders County, MT

The radar

The Missoula radar (KMSX), 122 km from the middle of the area, began a volume at 21:58 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, 9.9 hours before the alert went out and 135 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 2021-02-20Temperature 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 2021-02-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 square meters per square second.193958Sfc1 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
798 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

428 
WWUS75 KMSO 202156
NPWMSO

URGENT - WEATHER MESSAGE
National Weather Service Missoula MT
256 PM MST Sat Feb 20 2021

MTZ001-002-212200-
/O.NEW.KMSO.HW.A.0003.210222T0000Z-210222T1800Z/
Kootenai/Cabinet Region-West Glacier Region-
256 PM MST Sat Feb 20 2021

...HIGH WIND WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH MONDAY
MORNING...

* WHAT...Southwest winds 30 to 40 mph with gusts up to 60 mph 
  possible.

* WHERE...Highway 2 Kalispell to Libby, Highway 37 Eureka to 
  Libby, Highway 56 Bull Lake Road, Highway 93 Eureka to 
  Whitefish, Bad Rock Canyon, Essex, Highway 83 Bigfork to Swan 
  Lake, Marias Pass, and Polebridge.

* WHEN...From Sunday afternoon through Monday morning.

* IMPACTS...Damaging winds could blow down trees and power lines.
  Widespread power outages are possible. Travel could be
  difficult, especially for high profile vehicles. Periods of
  heavy snow are possible near Marias Pass and combined with the
  high wind will create blowing snow and reduced visibility.
 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and warnings for updates on this
situation. Fasten loose objects or shelter objects in a safe
location prior to the onset of winds.

&&

$$
1 follow-up statement
855 
WWUS75 KMSO 211742
NPWMSO

URGENT - WEATHER MESSAGE
National Weather Service Missoula MT
1042 AM MST Sun Feb 21 2021

MTZ002-211845-
/O.CAN.KMSO.HW.A.0003.210222T0000Z-210222T1800Z/
West Glacier Region-
1042 AM MST Sun Feb 21 2021

...HIGH WIND WATCH IS CANCELLED...


$$

MTZ001-221745-
/O.UPG.KMSO.HW.A.0003.210222T0000Z-210222T1800Z/
/O.NEW.KMSO.HW.W.0002.210221T2200Z-210222T1800Z/
Kootenai/Cabinet Region-
1042 AM MST Sun Feb 21 2021

...HIGH WIND WARNING IN EFFECT FROM 3 PM THIS AFTERNOON TO 11 AM
MST MONDAY...

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

* WHERE...Highway 2 Kalispell to Libby, Highway 37 Eureka to 
  Libby, Highway 56 Bull Lake Road, and Highway 93 Eureka to 
  Whitefish.

* WHEN...From 3 PM this afternoon to 11 AM MST Monday.

* 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. If possible, remain in the lower levels of
your home during the windstorm, and avoid windows. Use caution if
you must drive.

&&

$$

MTZ003-221745-
/O.NEW.KMSO.WI.Y.0003.210221T2200Z-210222T1800Z/
Flathead/Mission Valleys-
1042 AM MST Sun Feb 21 2021

...WIND ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 11 AM MST
MONDAY...

* WHAT...South winds 15 to 30 mph with gusts up to 40 mph 
  expected.

* WHERE...Flathead Lake, Flathead Valley, Mission Valley, and 
  Polson.

* WHEN...From 3 PM this afternoon to 11 AM MST Monday.

* 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.

&&

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 20, 4:51 PM MSTSpecial Weather StatementMSOPowell39 min

Nearby

High Wind Watches in Montana, 2021Every high wind watch 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.