Alert archive / Montana / Mesoscale Discussions in 2013

Mesoscale Discussion 1513

July 24, 20138 counties in Montana; Golden Valley County, North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 24, 2013, 11:31 PM MDT for 8 counties in Montana; Golden Valley County, North Dakota. It was in force for 29 min.

The area

The outline as issued.

The facts

Issued
Jul 24, 2013, 11:31 PM MDT (05:31 UTC)
Expired
Jul 25, 2013, 12:00 AM MDT
In force
29 min
Issued by
the Storm Prediction Center

Counties Dawson County, MT, Fergus County, MT, Garfield County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Prairie County, MT, Wibaux County, MT, Golden Valley County, ND

The radar

The Glasgow radar (KGGW), 116 km from the middle of the area, began a volume at 05:33 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 00:00Z, 5.5 hours before the alert went out and 319 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 2013-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 57 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 2013-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
57 J/kg
Mixed-layer CIN
-63 J/kg
Mixed-layer LCL
3725 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
66 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 24, 7:48 PM MDTMesoscale DiscussionSPCBlaine, Cascade, Chouteau, Custer, Dawson, Fallon and 17 more87 min

Nearby

Mesoscale Discussions in Montana, 2013Mesoscale Discussions in North Dakota, 2013Every mesoscale discussion in 2013

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.