Alert archive / Montana / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 14, NWS Billings, MT

July 17, 2012Carter County, Powder River County, Montana

NWS Billings, MT issued this severe thunderstorm warning at Jul 17, 2012, 5:14 PM MDT for Carter County, Powder River County, Montana. It was in force for 61 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 17, 2012, 5:14 PM MDT (23:14 UTC)
Expired
Jul 17, 2012, 6:15 PM MDT
In force
61 min
Issued by
NWS Billings, MT
Area
Storm-based polygon

Counties Carter County, MT, Powder River County, MT

The radar

The Rapid City radar (KUDX), 231 km from the middle of the area, began a volume at 23:17 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

Rapid City, SD (KUNR), launched 12:00Z, 11.2 hours before the alert went out and 232 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, Rapid City, SD at 12:00Z on 2012-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 377 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, Rapid City, SD at 12:00Z on 2012-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.1939Sfc1 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
377 J/kg
Mixed-layer CIN
-263 J/kg
Mixed-layer LCL
906 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 2:32 PM MDTSpecial Weather StatementBYZWheatland43 min
Jul 17, 4:01 PM MDTSpecial Weather StatementBYZStillwater59 min
Jul 17, 4:55 PM MDTSpecial Weather StatementBYZStillwater35 min
Jul 17, 5:06 PM MDTSpecial Weather StatementBYZMusselshell54 min
Jul 17, 5:19 PM MDTSpecial Weather StatementBYZBig Horn41 min
Jul 17, 5:56 PM MDTSpecial Weather StatementBYZCarbon49 min
Jul 17, 5:27 PM MDTSpecial Weather StatementBYZSheridan63 min

Nearby

Severe Thunderstorm Warnings in Montana, 2012Every severe thunderstorm warning in 2012

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.