Alert archive / Indiana / Mesoscale Discussions in 2017

Mesoscale Discussion 1294

July 12, 20174 states

The Storm Prediction Center issued this mesoscale discussion at Jul 12, 2017, 8:33 AM CDT for 4 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Jul 12, 2017, 8:33 AM CDT (13:33 UTC)
Expired
Jul 12, 2017, 10:30 AM CDT
In force
117 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 21 counties

Cook County, IL, DuPage County, IL, DeKalb County, IN, Elkhart County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Noble County, IN, Porter County, IN, Saint Joseph County, IN, Steuben County, IN, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Hillsdale County, MI, Kalamazoo County, MI, Saint Joseph County, MI, Van Buren County, MI, Williams County, OH

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 1.6 hours before the alert went out and 244 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, Detroit, MI at 12:00Z on 2017-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 327 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, Detroit, MI at 12:00Z on 2017-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 135 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
327 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
1006 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
135 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 11, 9:49 PM CDTMesoscale DiscussionSPCBoone, DeKalb, Jo Daviess, Kane, McHenry, Ogle and 2 more116 min

Nearby

Mesoscale Discussions in Indiana, 2017Mesoscale Discussions in Michigan, 2017Mesoscale Discussions in Illinois, 2017Every mesoscale discussion 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; the sounding from the Mesonet's radiosonde archive.