Alert archive / Montana / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 26, NWS Great Falls, MT

June 9, 2018Chouteau County, Fergus County, Judith Basin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 9, 2018, 6:35 PM MDT for Chouteau County, Fergus County, Judith Basin County, Montana. It was in force for 40 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 9, 2018, 6:35 PM MDT (00:35 UTC)
Expired
Jun 9, 2018, 7:15 PM MDT
In force
40 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Chouteau County, MT, Fergus County, MT, Judith Basin County, MT

The radar

The Great Falls radar (KTFX), 106 km from the middle of the area, began a volume at 00:38 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 9, 1:46 PM MDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 0.6 hours before the alert went out and 48 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, Great_falls, MT at 00:00Z on 2018-06-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 00:00Z on 2018-06-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 square meters per square second.19395878Sfc1 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
2 J/kg
Mixed-layer CIN
-68 J/kg
Mixed-layer LCL
4511 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Great Falls, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 9, 6:25 PM MDT, 10 minutes earlier.

Area forecast discussion, Jun 9, 6:25 PM MDT, 10 minutes before
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In the hours before

Special weather statement, Jun 9, 3:58 PM MDT, 2 hours 37 minutes before
Special Weather Statement
National Weather Service Great Falls MT
358 PM MDT SAT JUN 9 2018

MTZ009-046-048-092230-
Southern Rocky Mountain Front-Northern Rocky Mountain Front-Eastern
Pondera-
358 PM MDT SAT JUN 9 2018

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL PONDERA AND NORTH
CENTRAL TETON COUNTIES...

At 357 PM MDT, a strong thunderstorm was located 14 miles southwest
of Valier, or 22 miles west of Conrad, moving northeast at 40 mph.

Wind gusts up to 50 mph and pea size hail are possible with this
storm.

Locations impacted include...
Valier, Pendroy and Dupuyer.

This includes the following highways...
 Interstate 15 between mile markers 345 and 348.
 Highway 89 between mile markers 59 and 79.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4828 11188 4798 11240 4813 11266 4849 11225
TIME...MOT...LOC 2157Z 221DEG 33KT 4813 11244

Coulston
Special weather statement, Jun 9, 4:09 PM MDT, 2 hours 26 minutes before
Special Weather Statement
National Weather Service Great Falls MT
409 PM MDT SAT JUN 9 2018

MTZ010-044-092230-
Eastern Glacier-Toole-
409 PM MDT SAT JUN 9 2018

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHEASTERN GLACIER
AND NORTHWESTERN TOOLE COUNTIES...

At 409 PM MDT, radar indicated strong thunderstorms were located
along a line extending from 23 miles northwest of Cut Bank to near
Kevin. Movement was northeast at 50 mph.

Wind gusts up to 50 mph, brief heavy rain, and pea size hail are
possible with these storms.

Locations impacted include...
Sunburst, Kevin, Sweet Grass, Oilmont and Santa Rita.

This includes Interstate 15 between mile markers 378 and 397.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4900 11151 4865 11195 4885 11278 4900 11268
TIME...MOT...LOC 2209Z 214DEG 43KT 4894 11259 4881 11196

Coulston
Special weather statement, Jun 9, 4:29 PM MDT, 2 hours 6 minutes before
Special Weather Statement
National Weather Service Great Falls MT
429 PM MDT SAT JUN 9 2018

MTZ044-092245-
Toole MT-
429 PM MDT SAT JUN 9 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN TOOLE COUNTY UNTIL
445 PM MDT...

At 429 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles west of Sunburst, or 21 miles northeast of Cut Bank, moving
northeast at 35 mph.

Half inch hail and wind gusts up to 50 mph will be possible with this
storm.

Locations impacted include...
Sweet Grass.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
north central Montana.

LAT...LON 4900 11181 4888 11195 4891 11211 4894 11216
      4900 11215
TIME...MOT...LOC 2229Z 205DEG 32KT 4890 11207

KJ
Special weather statement, Jun 9, 4:51 PM MDT, 1 hour 44 minutes before
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Special weather statement, Jun 9, 5:10 PM MDT, 1 hour 25 minutes before
Special Weather Statement
National Weather Service Great Falls MT
510 PM MDT SAT JUN 9 2018

MTZ012-050-054-092345-
Cascade-Judith Basin-Meagher-
510 PM MDT SAT JUN 9 2018

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL MEAGHER...WEST
CENTRAL JUDITH BASIN AND SOUTHEASTERN CASCADE COUNTIES...

At 510 PM MDT, a strong thunderstorm was located 16 miles north of
White Sulphur Springs, moving north at 45 mph.

Wind gusts up to 50 mph and dime size hail are possible with this
storm.

Locations impacted include...
Neihart and Monarch.

This includes Highway 89 between mile markers 10 and 20, and between
mile markers 33 and 59.

LAT...LON 4669 11080 4671 11100 4720 11097 4715 11049
TIME...MOT...LOC 2310Z 191DEG 39KT 4678 11088

KJ
Special weather statement, Jun 9, 5:53 PM MDT, 42 minutes before
Special Weather Statement
National Weather Service Great Falls MT
553 PM MDT SAT JUN 9 2018

MTZ012-050-100030-
Cascade MT-Judith Basin MT-
553 PM MDT SAT JUN 9 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN MEAGHER...WESTERN
JUDITH BASIN AND SOUTHEASTERN CASCADE COUNTIES UNTIL 630 PM MDT...

At 552 PM MDT, Doppler radar was tracking a strong thunderstorm 23
miles northeast of White Sulphur Springs, moving northeast at 55 mph.

Half inch hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Stanford, Geyser and Windham.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
central Montana.

LAT...LON 4671 11050 4674 11056 4677 11056 4677 11062
      4682 11065 4684 11070 4684 11072 4685 11075
      4688 11076 4729 11051 4711 11001
TIME...MOT...LOC 2352Z 204DEG 46KT 4682 11061

PN

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 9, 6:36 PM MDTSpecial Weather StatementTFXHill24 min
Jun 9, 7:08 PM MDTSpecial Weather StatementTFXLiberty37 min
Jun 9, 7:10 PM MDTSpecial Weather StatementTFXHill35 min
Jun 9, 7:30 PM MDTSevere Thunderstorm WarningTFXFergus, Judith Basin30 min
Jun 9, 7:33 PM MDTSpecial Weather StatementTFXChouteau27 min
Jun 9, 7:57 PM MDTSpecial Weather StatementTFXHill33 min
Jun 9, 8:25 PM MDTSpecial Weather StatementTFXFergus50 min
Jun 9, 8:31 PM MDTSpecial Weather StatementTFXHill29 min
Jun 9, 9:16 PM MDTSpecial Weather StatementTFXFergus29 min
Jun 9, 9:45 PM MDTSpecial Weather StatementTFX30 min
Jun 9, 10:47 PM MDTSevere Thunderstorm WarningTFXBlaine43 min
Jun 9, 11:34 PM MDTFlash Flood WarningTFXBlaine6 hr

Nearby

Severe Thunderstorm Warnings in Montana, 2018Every severe thunderstorm warning in 2018

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.