Alert archive / Minnesota / Mesoscale Discussions in 2015

Mesoscale Discussion 1808

September 17, 2015Itasca County, Lake County, Saint Louis County, Minnesota

The Storm Prediction Center issued this mesoscale discussion at Sep 17, 2015, 12:44 PM CDT for Itasca County, Lake County, Saint Louis County, Minnesota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 17, 2015, 12:44 PM CDT (17:44 UTC)
Expired
Sep 17, 2015, 2:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Itasca County, MN, Lake County, MN, Saint Louis County, MN

The radar

The Duluth radar (KDLH), 103 km from the middle of the area, began a volume at 17:46 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

Minneapolis, MN (KMPX), launched 12:00Z, 5.7 hours before the alert went out and 336 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, Minneapolis, MN at 12:00Z on 2015-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1229 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, Minneapolis, MN at 12:00Z on 2015-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 328 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
1229 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
620 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
328 m²/s²
0-3 km storm-relative helicity
353 m²/s²
Significant tornado parameter
0.0
Supercell composite
10.0

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
Sep 17, 3:58 PM CDTMesoscale DiscussionSPCAnoka, Benton, Blue Earth, Brown, Carlton, Carver and 31 more2 hr

Nearby

Mesoscale Discussions in Minnesota, 2015Every mesoscale discussion in 2015

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.