Alert archive / Montana / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 21, NWS Great Falls, MT

June 4, 2017Cascade County, Chouteau County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 4, 2017, 4:40 PM MDT for Cascade County, Chouteau County, Montana. It was in force for 35 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jun 4, 2017, 4:40 PM MDT (22:40 UTC)
Expired
Jun 4, 2017, 5:15 PM MDT
In force
35 min
Issued by
NWS Great Falls, MT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Cascade County, MT, Chouteau County, MT

The radar

The Great Falls radar (KTFX), 33 km from the middle of the area, began a volume at 22:39 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.

What was reported inside it

TimeReportWhereRemark
Jun 4, 4:43 PM MDTHAIL 17 Ene Malmstrom Afb, MTSPOTTER REPORTED QUARTER-SIZE HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.7 hours before the alert went out and 27 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 2017-06-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 37 joules per kilogram.LCLLFCEL10008507005003002001001 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, Great_falls, MT at 12:00Z on 2017-06-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 square meters per square second.193958Sfc1 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
37 J/kg
Mixed-layer CIN
-323 J/kg
Mixed-layer LCL
2484 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

251 
WUUS55 KTFX 042240
SVRTFX
MTC013-015-042315-
/O.NEW.KTFX.SV.W.0021.170604T2240Z-170604T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Great Falls MT
440 PM MDT SUN JUN 4 2017

The National Weather Service in Great Falls has issued a

* Severe Thunderstorm Warning for...
  Southwestern Chouteau County in north central Montana...
  Northeastern Cascade County in central Montana...

* Until 515 PM MDT

* At 438 PM MDT, a severe thunderstorm was located 8 miles northwest
  of Belt, or 12 miles east of Great Falls, moving northeast at 25
  mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...At 432 PM, trained weather spotters reported a 60 mph 
           wind gust on the east side of Great Falls along with 
           penny size hail. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Belt, Highwood, Carter, Shonkin, Floweree, Armington, Portage and
  Malmstrom Afb.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

&&

LAT...LON 4733 11093 4737 11110 4750 11119 4788 11113
      4763 11041
TIME...MOT...LOC 2238Z 211DEG 20KT 4748 11103 

HAIL...1.00IN
WIND...60MPH
 
$$

MARTIN
1 follow-up statement
667 
WWUS55 KTFX 042249
SVSTFX

Severe Weather Statement
National Weather Service Great Falls MT
449 PM MDT SUN JUN 4 2017

MTC013-015-042315-
/O.CON.KTFX.SV.W.0021.000000T0000Z-170604T2315Z/
Chouteau MT-Cascade MT-
449 PM MDT SUN JUN 4 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM MDT
FOR SOUTHWESTERN CHOUTEAU AND NORTHEASTERN CASCADE COUNTIES...

At 447 PM MDT, a severe thunderstorm was located 10 miles southwest
of Highwood, or 14 miles east of Great Falls, moving northeast at 25
mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...At 443 PM, trained weather spotters reported quarter size 
         hail 7 miles northeast of Great Falls. This storm also has 
         a history of producing damaging wind gusts.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

Locations impacted include...
Belt, Highwood, Carter, Shonkin, Floweree, Portage and Malmstrom Afb.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 4738 11091 4741 11107 4753 11118 4788 11113
      4763 11041
TIME...MOT...LOC 2247Z 211DEG 20KT 4753 11099 

HAIL...1.00IN
WIND...60MPH
 
$$

MARTIN

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 4, 2:19 PM MDTSpecial Weather StatementTFXBroadwater41 min
Jun 4, 2:54 PM MDTSpecial Weather StatementTFX36 min
Jun 4, 3:08 PM MDTSpecial Weather StatementTFXCascade52 min
Jun 4, 3:25 PM MDTSevere Thunderstorm WarningTFXCascade36 min
Jun 4, 3:33 PM MDTSpecial Weather StatementTFXFergus42 min
Jun 4, 4:08 PM MDTSpecial Weather StatementTFXCascade37 min
Jun 4, 4:18 PM MDTSevere Thunderstorm WarningTFXCascade27 min
Jun 4, 5:00 PM MDTSpecial Weather StatementTFXLewis and Clark45 min
Jun 4, 5:11 PM MDTSevere Thunderstorm WarningTFXLewis and Clark34 min
Jun 4, 5:13 PM MDTSevere Thunderstorm WarningTFXChouteau32 min
Jun 4, 5:39 PM MDTSpecial Weather StatementTFXTeton36 min
Jun 4, 5:49 PM MDTSpecial Weather StatementTFXChouteau41 min

Nearby

Severe Thunderstorm Warnings in Montana, 2017Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.