Storm Spotter Page |
Skywarn™ Weather Spotters are
critical to the mission of the National Weather Service, which is to protect
lives and property by issuing watches, warnings and advisories. The
NWS has a lot of highly sophisticated equipment such as satellites and
radars, but these tools do not replace the very important “ground truth”
that weather spotters provide. Weather warnings are issued
based on these reports, and can save lives and property of those living
downstream of a spotter report.
In northeast Montana, there are approximately
1000 weather observers in the 12 counties and one reservation that NWS
Glasgow serves. Weather spotters are asked to report hazardous weather
conditions, using an 800 phone number they are given during Skywarn Spotter
training. The general public is welcome to call the NWS in Glasgow
at 406-228-4042. The Skywarn Spotter courses are generally held in
April and May in various locations around the region. A training
schedule is posted on the website each spring.
Weather Spotters are asked to report the
following hazardous weather conditions in northeast Montana as soon as
possible:
1. Tornadoes, funnel
clouds, waterspouts
2. Hail of any
size (see hail size chart below)
3. Winds sustained
at 40 mph or higher and any gusts 55 mph or higher
(see wind estimation guidelines chart below)
4. Snowfall, Total
Snow Depth, Freezing Rain that is accumulating
5. Significant
damage from weather
6. River Flooding,
Flash Flooding, Small Creek Flooding, Ice Jams
Watch/Warning Criteria
for Thunderstorms, Winds, Snow and Flooding (.pdf file - Download Adobe Reader)
Interested in reporting precipitation more
frequently? Join the CoCoRaHS
(Community Collaborative Rain, Hail and Snow) weather spotter network.
Spotter safety is our #1 priority with our
weather spotter program. We do not ask our weather spotters to chase
storms in their area. Rather we ask that they report from their location,
but only if it is safe to do so.
If you are not currently a weather spotter,
but would like to be one, contact the NWS Glasgow via
email or phone (406-228-4042).
Under the Big Sky Quarterly Newsletter
• Winter 2008
• Fall 2007
• Summer 2007
• Spring 2007
Weather Spotters eletter (.pdf files - Download Adobe Reader)
• September 12, 2008
• August 29, 2008
• August 15, 2008 - Simplified Winter Weather Products
• July 24, 2008
• July 11, 2008
• June 26, 2008
• June 13, 2008
• June 9, 2008
• May 22, 2008
• May 15, 2008
• April 22, 2008 - Green Edition
• April 4, 2008
• March 26, 2008
• March 14, 2008
Skywarn Spotter Resources:
1. Basic
Spotters Guide
2. Advanced
Spotters Guide
3. History
of weather spotter program
4. Online
Glossary of Weather Terms for Storm Spotters
5. Montana
Hazardous Weather Guide
Hail Size
Comparison Chart
Pea |
.25” |
Golf Ball |
1.75” |
Half-inch |
.50” |
Hen Egg |
2.00” |
Penny |
.75” |
Tennis Ball |
2.5” |
Nickel |
.88” |
Baseball |
2.75” |
Quarter |
1.00” |
Tea Cup |
3.00” |
Half Dollar |
1.25” |
Grapefruit |
4.00” |
Ping Pong |
1.5” |
Softball |
4.5” |
Note: Because they come in so many sizes,
please do not report hail size as “marbles.”
Guidelines
for estimating wind speeds
30-44 mph
(26-39 kts) |
Whole trees in motion. Inconvenient
walking into the wind. Light-weight loose objects (e.g., lawn furniture)
tossed or toppled. |
45-57 mph
(39-49 kts) |
Large trees bend; twigs, small limbs break
and a few larger dead or weak branches may break. Old/weak structures
(e.g., sheds, barns) may sustain minor damage (roof, doors). Buildings
partially under construction may be damaged. A few loose shingles
removed from houses. |
58-74 mph
(50-64 kts) |
Large limbs break; shallow rooted trees
pushed over. Semi-trucks overturned. More significant damage to old/weak
structures. Shingles, awnings removed from houses; damage to chimneys
and antennas. |
75-89 mph
(65-77 kts) |
Widespread damage to trees with large limbs
down or trees broken/uprooted. Mobile homes may be pushed off foundation
or overturned. Roof may be partially peeled off industrial/commercial/
warehouse buildings. Some minor roof damage to homes. Weak
structures (e.g., farm buildings, airplane hangars) may be severely damaged. |
90+ mph
(78+ kts) |
Many large trees broken and uprooted.
Mobile homes damaged. Roofs partially peeled off homes and buildings.
Moving automobiles pushed off the road. Barns, sheds demolished. |
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