Alert archive / Montana / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 104, NWS Great Falls, MT

July 30, 2019Jefferson County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 30, 2019, 5:11 PM MDT for Jefferson County, Montana. It was in force for 45 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
Jul 30, 2019, 5:11 PM MDT (23:11 UTC)
Expired
Jul 30, 2019, 5:56 PM MDT
In force
45 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Jefferson County, MT

The radar

The Great Falls radar (KTFX), 155 km from the middle of the area, began a volume at 23:15 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

Great_falls, MT (KTFX), launched 12:00Z, 11.2 hours before the alert went out and 185 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 12:00Z on 2019-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 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 12:00Z on 2019-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939587897Sfc1 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
11 J/kg
Mixed-layer CIN
-247 J/kg
Mixed-layer LCL
2378 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
69 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 Jul 30, 5:00 PM MDT, 11 minutes earlier.

Area forecast discussion, Jul 30, 5:00 PM MDT, 11 minutes before
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In the hours before

Special weather statement, Jul 30, 2:26 PM MDT, 2 hours 45 minutes before
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Local storm report, Jul 30, 2:32 PM MDT, 2 hours 39 minutes before
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Special weather statement, Jul 30, 2:37 PM MDT, 2 hours 34 minutes before
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Special weather statement, Jul 30, 3:00 PM MDT, 2 hours 11 minutes before
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Local storm report, Jul 30, 3:18 PM MDT, 1 hour 53 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
318 PM MDT TUE JUL 30 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0238 PM     TSTM WND GST     5 WSW GREAT FALLS       47.47N 111.38W
07/30/2019  M44 MPH          CASCADE            MT   ASOS

            ASOS STATION KGTF GREAT FALLS.

&&
Special weather statement, Jul 30, 4:15 PM MDT, 56 minutes before
Special Weather Statement
National Weather Service Great Falls MT
415 PM MDT Tue Jul 30 2019

MTZ008-302300-
Beaverhead MT-
415 PM MDT Tue Jul 30 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN BEAVERHEAD COUNTY
UNTIL 500 PM MDT...

At 414 PM MDT, Doppler radar was tracking strong thunderstorms near
Gibbonsville, or 30 miles north of Salmon, moving east at 20 mph.

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

Locations impacted include...Wisdom.

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.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
office in Great Falls.

&&

LAT...LON 4578 11387 4576 11385 4575 11381 4584 11370
      4588 11354 4594 11351 4576 11339 4576 11336
      4581 11333 4583 11326 4558 11312 4553 11383
      4559 11380 4562 11390 4569 11394
TIME...MOT...LOC 2214Z 262DEG 15KT 4561 11400

JAF

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 6:13 PM MDTSpecial Weather StatementTFXBroadwater, Meagher32 min
Jul 29, 6:30 PM MDTSpecial Weather StatementTFXJefferson45 min
Jul 29, 6:42 PM MDTSpecial Weather StatementTFXMeagher48 min
Jul 29, 6:58 PM MDTSpecial Weather StatementTFXLewis and Clark47 min
Jul 29, 6:59 PM MDTSpecial Weather StatementTFXBeaverhead46 min
Jul 29, 8:30 PM MDTSpecial Weather StatementTFXJudith Basin45 min
Jul 29, 8:44 PM MDTSpecial Weather StatementTFX46 min
Jul 29, 9:13 PM MDTSpecial Weather StatementTFXFergus47 min
Jul 29, 9:18 PM MDTSpecial Weather StatementTFXLewis and Clark12 min
Jul 29, 9:26 PM MDTSpecial Weather StatementTFXMadison49 min
Jul 29, 9:32 PM MDTSpecial Weather StatementTFXLewis and Clark13 min
Jul 29, 9:40 PM MDTSpecial Weather StatementTFXFergus50 min
Jul 29, 9:47 PM MDTSpecial Weather StatementTFXLewis and Clark13 min
Jul 29, 9:59 PM MDTSpecial Weather StatementTFXLewis and Clark31 min
Jul 29, 10:19 PM MDTSpecial Weather StatementTFX41 min
Jul 29, 10:28 PM MDTSpecial Weather StatementTFXLewis and Clark32 min
Jul 29, 10:58 PM MDTSpecial Weather StatementTFXLewis and Clark32 min
Jul 30, 1:45 PM MDTSpecial Weather StatementTFXBroadwater60 min
Jul 30, 2:26 PM MDTSpecial Weather StatementTFXBroadwater49 min
Jul 30, 2:37 PM MDTSpecial Weather StatementTFXCascade38 min
Jul 30, 3:00 PM MDTSpecial Weather StatementTFXCascade45 min
Jul 30, 4:15 PM MDTSpecial Weather StatementTFXDeer Lodge45 min
Jul 30, 5:30 PM MDTSpecial Weather StatementTFXBroadwater45 min
Jul 30, 5:50 PM MDTSpecial Weather StatementTFXChouteau40 min

Nearby

Severe Thunderstorm Warnings in Montana, 2019Every severe thunderstorm warning in 2019

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.