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Missoula, Montana
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Short Fuse Warning/Watch
Products related to Severe Thunderstorms
(WFO Missoula)

AFOS/AWIPS Product Category

Product

Issued For

Issuing Office

GTFSVRMSO

Severe Thunderstorm Warning

1 inch hail, 50 kt wind (58 mph)

WFO Missoula

GTFFFWMSO

Severe Thunderstorm and Flash Flood Warning

1 inch hail, 50 kt wind (58 mph) combined with flash flooding

WFO Missoula

GTFSEL#

Severe Thunderstorm Watch by box

forecast of conditions favorable for severe thunderstorm development

SPC

GTFSEV#

Severe Thunderstorm Watch by counties

forecast of conditions favorable for severe thunderstorm development

SPC

GTFSVSMSO

Severe Weather Statement

observed severe weather, canceling all or part of a warning

WFO Missoula

GTFSPSMSO

Special Weather Statement

canceling all or part of a watch

WFO Missoula

GTFLSRMSO

Local Storm/Spotter Report

reporting severe or significant weather by location, time, and effect; e.g. damage, death, injuries. Include information source

WFO Missoula




Products related to Tornadoes
(WFO Missoula)

AFOS/AWIPS Product Category

Product

Issued For

Issuing Office

GTFTORMSO

Tornado Warning

tornado or funnel cloud observed

WFO Missoula

GTFTORMSO

Tornado and Flash Flood Warning

tornado or funnel cloud observed with flash flooding rainfall

WFO Missoula

GTFSEL#

Tornado/Severe Thunderstorm Watch by box

forecast of conditions favorable for severe thunderstorm development

SPC

GTFSEV#

Tornado/Severe Thunderstorm Watch by counties

forecast of conditions favorable for severe thunderstorm development

SPC

GTFSVSMSO

Severe Weather Statement

more information on Tornado warning, cancellation, or a statement to report a tornado which dissipated before a warning could be issued

WFO Missoula

GTFLSRMSO

Storm Report

reporting severe or significant weather by location, time, and effect; e.g. damage, death, injuries. Include information source

WFO Missoula




Products related to Flooding
(WFO Missoula)

AFOS/AWIPS Product Category

Product

Issued For

Issuing Office

GTFFFWMSO

Flash Flood Warning

urban and small stream flash flooding that is imminent or in progress--life threatening

WFO Missoula

GTFFLWMSO

Flood Warning

major river flooding that is imminent or in progress

WFO Missoula

GTFFFAMSO

Flash Flood/Flood Watch

a threat of flash flooding or flooding when occurrence is not yet certain or imminent; usually more than 6 hours lead time

WFO Missoula

GTFFLWMSO

Small Stream Flood Warning

small stream flooding that is imminent or in progress

not life threatening but is causing property damage

WFO Missoula

GTFFLWMSO

Urban Flood Warning

urban flooding that is imminent or in progress

not life threatening but is causing property damage

WFO Missoula

GTFFLWMSO

Urban and Small Stream Flood Warning

urban and small stream flooding that is imminent or in progress - not life threatening but is causing property damage

WFO Missoula

GTFFLSMSO

Urban and Small Stream Flood Advisory

urban and/or small stream flooding that is a significant inconvenience--not life threatening and causing property damage

WFO Missoula

GTFFFSMSO

Flash Flood Statement

more information on a flash flood watch or warning or to cancel all or a part of those products

WFO Missoula

GTFFLSMSO

Flood Statement

more information on a flood watch, warning or advisory, or to cancel all or part of those products

WFO Missoula

GTFLSRMSO

Local Storm/Spotter Report

reporting flash flooding or other types of flooding by time, location and effect; e.g. damage, death, injuries. Include information source

WFO Missoula



Winter Weather Warnings/Advisories
(Missoula WFO)

Product
Definition
Winter Storm Watch issued when hazardous weather is forecast to occur, but timing is still uncertain, such as second, third or fourth periods
Winter Storm Warning

** Issued when heavy snow criteria is expected alone, widespread freezing rain is expected alone, or any combination of the following:**

  1. Significant blowing and/or drifting of snow
  2. Sustained and/or frequent wind gusts >20 mph and <35 mph
  3. Wind Chills <20 below zero
  4. Freezing Rain or Sleet.

Heavy Snow Criteria:

Warm Season:
(Early May to mid October)

ALL ELEVATIONS including MSO and GPI Airports:

  • 4 inches or more of snow in 12 hours, or
  • 6 inches or more in 24 hours ...

 

Cool Season
(Mid October to Early May)

Idaho and Montana

Montana:

Zones 3, 5 <= 3500 feet and below

Zones 1, 4, 43 <= 4500 feet and below

Zones 2, 6, <= 5000 feet and below

Zone 7 <= 6000 feet and below

  • 6 inches or more in 12 hours..or
  • 8 inches or more in 24 hours

Idaho::

Zones 5, 9 <= 4000 feet and below

Zones 7, 8 <= 5000 feet and below

Zones 6 <= 6000 feet and below

Zone 10 <= 6500 feet and below

  • 6 inches or more in 12 hours...or
  • 8 inches or more in 24 hours


Criteria for all roadway mountain passes open in winter for Montana
and Idaho regardless of elevation:

8 inches or more of snow in 12 hours...or

12 inches or more in 24 hours


MSO and GPI Airports:
4 inches or more of snow in 12 hours...or

6 inches or more in 24 hours

Winter Weather Advisory Issued when one or multiple hazardous winter weather events (i.e. snow, blowing and drifting snow, freezing rain or drizzle) are either occurring, imminent or have a very high probability of occurring. Advisories are used when conditions pose a significant inconvenience to the public.

**A winter weather advisory may be issued for one or any combination of the following occuring or expected events:**
  1. Snow within the criteria amounts listed below
  2. Blowing and/or drifting of snow
  3. Snow and wind chills between 10F below and 20F below zero.
  4. Snow and freezing rain

Winter Weather Advisory criteria for snow alone is as follows:

Warm Season:
(Early May to mid October)

ALL ELEVATIONS:

  • 1 to 3 inches in 12 hours

 

Cool Season
(Mid October to Early May)

Idaho and Montana

Montana:

Zones 3, 5 <= 3500 feet, Zones 1, 4, 43 <= 4500 feet, Zones 2, 6, <= 5000 feet, and Zone 7 <= 6000 feet

Idaho:

Zones 5, 9 <= 4000 feet, Zones 7, 8 <= 5000 feet, Zone 6 <= 6000 feet and Zone 10 <= 6500 feet,

and GPI and MSO airports

  • 2 to 5 inches in 12 hours, where 4 inches triggers AWWGPI and AWWMSO issuance
  • Snow amount criteria for all mountain passes: 4" to 7" in 12 Hours.

Winter Weather Advisory for blowing and/or drifting snow:

This is issued when strong winds (accompanied either with or without snowfall) are occuring or expected in an area that has snowfall accumulation and is picked up and blown. This will result in reduced visibility and and travel inconveniences. Drifting snow is an uneven distribution of snowfall/depth caused by strong surface wind, which may occur during or after snowfall.

Freezing Rain Advisory issued for freezing rain or drizzle:

This is issued when freezing rain or drizzle is or will be occuring usually less than 3 hrs and not widespread, where conditions will pose a significant inconvenience from precipitation that is generally light.

Blizzard Warning the following conditions are expected to prevail for 3 hours or longer:

sustained winds or gusts to 35 mph or more AND considerable falling or blowing snow, reducing visibilities frequently to < 1/4 mile

Ice Storm Warning 1/4 inch accumulation of ice, and when significant and possibly damaging accumulation of ice are expected




Anywhere










Wind Advisory 

Lake Wind Advisory

Issued for sustained winds >=30 mph, < 40 mph or gusts to >= 40 mph

Issued only from April 1 to November 30 for sustained winds > 20 mph, < 40 mph or gusts to 30 mph


GTFNPWMSO

High Wind Warning

Sustained winds >= 40 mph and/or gusts >= 50 mph (58 mph Camas Prairie IDZ007)

GTFNPWMSO

Freeze Warning

Temps at or below 32 over a large area for a significant period or time during the growing season

GTFNPWMSO

Frost Warning

When frost is expected over a large area during the growing season

GTFNPWMSO

High Wind Watch

Normally issued when high winds are expected in the latter portion of the first forecast period or in the second or third periods.

GTFNPWMSO

Wind Chill Warning


-20 F or less with wind >= 10 mph and duration > 1 hour

GTFWSWMSO

Wind Chill Advisory




-10 F or less with wind >= 10 mph and duration > 1 hour

GTFWSWMSO

Dense Fog Advisory

Widespread visibility of less than 1/4 mile

GTFNPWMSO

Dust Storm Warning

Widespread visibility of ¼ mile or less and winds 30 mph or greater

GTFNPWMSO

Volcanic Ash Advisory

Whenever it occurs

GTFNPWMSO


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US Dept of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
Missoula Weather Forecast Office
6633 Aviation Way
Missoula, MT 59808-9381

Tel: (406) 329-4840

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