Alert archive / Montana / High Wind Watches in 2017

High Wind Watch 2, NWS Missoula, MT

November 21, 20179 counties in Montana

NWS Missoula, MT issued this high wind watch at Nov 21, 2017, 1:14 PM MST for 9 counties in Montana. It took effect at Nov 23, 2017, 5:00 PM MST. It was in force for .

The area

The counties it named.

The facts

Issued
Nov 21, 2017, 1:14 PM MST (20:14 UTC)
In effect from
Nov 23, 2017, 5:00 PM MST
Expired
Nov 23, 2017, 3:27 AM MST
In force
Issued by
NWS Missoula, MT

Counties Deer Lodge County, MT, Flathead County, MT, Granite County, MT, Lake County, MT, Missoula County, MT, Powell County, MT, Ravalli County, MT, Sanders County, MT, Silver Bow County, MT

The radar

The Missoula radar (KMSX), 27 km from the middle of the area, began a volume at 20:20 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, 8.2 hours before the alert went out and 222 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 2017-11-21Temperature 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 2017-11-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 165 square meters per square second.1939587897117136Sfc1 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
858 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
165 m²/s²
0-3 km storm-relative helicity
269 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

777 
WWUS75 KMSO 212014
NPWMSO

URGENT - WEATHER MESSAGE
National Weather Service Missoula MT
114 PM MST Tue Nov 21 2017

MTZ002-003-005>007-043-232015-
/O.NEW.KMSO.HW.A.0002.171124T0000Z-171124T1200Z/
West Glacier Region-Flathead/Mission Valleys-
Missoula/Bitterroot Valleys-Bitterroot/Sapphire Mountains-
Butte/Blackfoot Region-Potomac/Seeley Lake Region-
114 PM MST Tue Nov 21 2017

...HIGH WIND WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH LATE
THURSDAY NIGHT...

The National Weather Service in Missoula has issued a High Wind
Watch...which is in effect from Thursday afternoon through late
Thursday night. 

* Impacts/Timing: A strong cold front moving through the Northern
  Rockies on Thanksgiving day, has the potential to produce 
  strong, and potentially damaging wind gusts. Impacting area 
  trees and powerlines, starting late afternoon Thursday across 
  Northwestern Montana, and during the evening after sunset for 
  the rest of western Montana.

* Winds: West-southwest winds sustained at 25 to 35 mph, with 
  gusts of 50 to 60 mph along the cold front.

* Locations impacted include: Bad Rock Canyon, Essex, Highway 83 
  Bigfork to Swan Lake, Marias Pass, Polebridge, Flathead Lake, 
  Flathead Valley, Mission Valley, Polson, Bitterroot Valley, 
  Missoula, Highway 93 Sula to Lost Trail Pass, Lolo Pass, 
  Butte, Georgetown Lake, Highway 12 Garrison to Elliston, 
  Homestake Pass, MacDonald Pass, Highway 200 Bonner to 
  Greenough, Highway 83 Seeley Lake to Condon, and I-90 East 
  Missoula to Bearmouth

$$
2 follow-up statements
134 
WWUS75 KMSO 230546
NPWMSO

URGENT - WEATHER MESSAGE
National Weather Service Missoula MT
1046 PM MST Wed Nov 22 2017

MTZ005-240600-
/O.NEW.KMSO.FG.Y.0005.171123T0546Z-171123T1800Z/
/O.CON.KMSO.HW.A.0002.171124T0000Z-171124T1200Z/
Missoula/Bitterroot Valleys-
1046 PM MST Wed Nov 22 2017

...DENSE FOG ADVISORY IN EFFECT UNTIL 11 AM MST THURSDAY FOR
BITTERROOT VALLEY AND MISSOULA...
...HIGH WIND WATCH REMAINS IN EFFECT FROM THURSDAY AFTERNOON
THROUGH LATE THURSDAY NIGHT FOR BITTERROOT VALLEY AND MISSOULA...

The National Weather Service in Missoula has issued a Dense Fog
Advisory...which is in effect until 11 AM MST Thursday. 

* Impacts/Timing: Dense fog will occur through Thursday morning
  with visibility lowering to less than one quarter mile at times.
  Temperatures at or below freezing could cause a thin layer of
  ice to form on roadways, particularly on bridges and overpasses.

* Visibility: Less than one quarter mile.

* Locations impacted include: Missoula valley, Bitterroot valley,
  I-90 near Missoula.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Dense Fog Advisory means visibilities will frequently be
reduced to less than one quarter mile. If driving, slow down, use
your headlights, and leave plenty of distance ahead of you.

&&

$$

MTZ004-231800-
/O.NEW.KMSO.FG.Y.0005.171123T0546Z-171123T1800Z/
Lower Clark Fork Region-
1046 PM MST Wed Nov 22 2017

...DENSE FOG ADVISORY IN EFFECT UNTIL 11 AM MST THURSDAY...

The National Weather Service in Missoula has issued a Dense Fog
Advisory...which is in effect until 11 AM MST Thursday. 

* Impacts/Timing: Dense fog will occur through Thursday morning
  with visibility lowering to less than one quarter mile at times.
  Temperatures at or below freezing could cause a thin layer of
  ice to form on roadways, particularly on bridges and overpasses.

* Visibility: Less than one quarter mile.

* Locations impacted include: Evaro Hill, Highway 200 Thompson 
  Falls to Plains, Highway 200 Trout Creek to Heron, and I- 90 
  Lookout Pass to Haugan

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Dense Fog Advisory means visibilities will frequently be
reduced to less than one quarter mile. If driving, slow down, use
your headlights, and leave plenty of distance ahead of you.

&&

$$

MTZ002-003-006-007-043-240600-
/O.CON.KMSO.HW.A.0002.171124T0000Z-171124T1200Z/
West Glacier Region-Flathead/Mission Valleys-
Bitterroot/Sapphire Mountains-Butte/Blackfoot Region-
Potomac/Seeley Lake Region-
1046 PM MST Wed Nov 22 2017

...HIGH WIND WATCH REMAINS IN EFFECT FROM THURSDAY AFTERNOON
THROUGH LATE THURSDAY NIGHT...

* Impacts/Timing: A strong cold front moving through the 
  Northern Rockies on Thanksgiving day, has the potential to 
  produce strong, and potentially damaging wind gusts. Impacting 
  area trees and powerlines, starting late afternoon Thursday 
  across Northwestern Montana, and during the evening after 
  sunset for the rest of western Montana. 

* Winds: West-southwest winds sustained at 25 to 35 mph, with 
  gusts of 50 to 60 mph along the cold front. 

* Locations impacted include: Bad Rock Canyon, Essex, Highway 83 
  Bigfork to Swan Lake, Marias Pass, Polebridge, Flathead Lake, 
  Flathead Valley, Mission Valley, Polson, Highway 93 Sula to 
  Lost Trail Pass, Lolo Pass, Butte, Georgetown Lake, Highway 12 
  Garrison to Elliston, Homestake Pass, MacDonald Pass, Highway 
  200 Bonner to Greenough, Highway 83 Seeley Lake to Condon, and 
  I- 90 East Missoula to Bearmouth

$$
870 
WWUS75 KMSO 231027
NPWMSO

URGENT - WEATHER MESSAGE
National Weather Service Missoula MT
327 AM MST Thu Nov 23 2017

MTZ005-241100-
/O.CAN.KMSO.FG.Y.0005.000000T0000Z-171123T1800Z/
/O.UPG.KMSO.HW.A.0002.171124T0000Z-171124T1200Z/
/O.NEW.KMSO.WI.Y.0008.171124T0000Z-171124T1200Z/
Missoula/Bitterroot Valleys-
327 AM MST Thu Nov 23 2017

...WIND ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO 5 AM MST
FRIDAY FOR BITTERROOT VALLEY AND MISSOULA...

The National Weather Service in Missoula has issued a Wind
Advisory...which is in effect from 5 PM this afternoon to 5 AM
MST Friday. 

* Impacts/Timing: A strong cold front moving through the region 
  today will produce gusty winds after 5 PM. The threat for 
  widespread damaging winds has lessened quite a bit the past 24 
  hours. However...isolated areas could still see a very brief 
  period of winds that could cause localized tree damage. 

* Winds: West-southwest winds sustained at 20 to 30 mph, with
  gusts of 40 to 45 mph along the cold front.

* Locations Impacted: Missoula and Bitterroot Valley.

$$

MTZ004-231130-
/O.CAN.KMSO.FG.Y.0005.000000T0000Z-171123T1800Z/
Lower Clark Fork Region-
327 AM MST Thu Nov 23 2017

...DENSE FOG ADVISORY IS CANCELLED...

$$

MTZ002-003-241100-
/O.UPG.KMSO.HW.A.0002.171124T0000Z-171124T1200Z/
/O.NEW.KMSO.WI.Y.0008.171123T2000Z-171124T0600Z/
West Glacier Region-Flathead/Mission Valleys-
327 AM MST Thu Nov 23 2017

...WIND ADVISORY IN EFFECT FROM 1 PM THIS AFTERNOON TO 11 PM MST
THIS EVENING...

The National Weather Service in Missoula has issued a Wind
Advisory...which is in effect from 1 PM this afternoon to 11 PM
MST this evening. The High Wind Watch is no longer in effect. 

* Impacts/Timing: A strong cold front moving through the region 
  today will produce gusty winds after 1 PM. The threat for 
  widespread damaging winds has lessened quite a bit the past 24 
  hours. However...isolated areas could still see a very brief 
  period of winds that could cause localized tree damage. 

* Winds: West-southwest winds sustained at 20 to 30 mph, with
  gusts of 40 to 45 mph along the cold front. 

* Locations impacted include: Bad Rock Canyon, Essex, Highway 83 
  Bigfork to Swan Lake, Marias Pass, Polebridge, Flathead Lake, 
  Flathead Valley, Mission Valley, and Polson

$$

MTZ006-007-043-241100-
/O.UPG.KMSO.HW.A.0002.171124T0000Z-171124T1200Z/
/O.NEW.KMSO.WI.Y.0008.171124T0000Z-171124T1200Z/
Bitterroot/Sapphire Mountains-Butte/Blackfoot Region-
Potomac/Seeley Lake Region-
327 AM MST Thu Nov 23 2017

...WIND ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO 5 AM MST
FRIDAY...

The National Weather Service in Missoula has issued a Wind
Advisory...which is in effect from 5 PM this afternoon to 5 AM
MST Friday. The High Wind Watch is no longer in effect. 

* Impacts/Timing: A strong cold front moving through the region 
  today will produce gusty winds after 5 PM. The threat for 
  widespread damaging winds has lessened quite a bit the past 24 
  hours. However...isolated areas could still see a very brief 
  period of winds that could cause localized tree damage. 

* Winds: West-southwest winds sustained at 20 to 30 mph, with
  gusts of 40 to 45 mph along the cold front. 

* Locations impacted include: Highway 93 Sula to Lost Trail 
  Pass, Lolo Pass, Butte, Georgetown Lake, Highway 12 Garrison 
  to Elliston, Homestake Pass, MacDonald Pass, Highway 200 
  Bonner to Greenough, Highway 83 Seeley Lake to Condon, and I-
  90 East Missoula to Bearmouth

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 21, 4:45 AM MSTDense Fog AdvisoryMSOGranite, Lake, Mineral, Missoula, Powell, Ravalli and 1 more6 hr

Nearby

High Wind Watches in Montana, 2017Every high wind watch in 2017

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.