Alert archive / Minnesota / Mesoscale Discussions in 2018

Mesoscale Discussion 1473

September 18, 20188 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2018, 1:57 AM CDT for 8 counties in Minnesota. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Sep 18, 2018, 1:57 AM CDT (06:57 UTC)
Expired
Sep 18, 2018, 4:30 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
5%

Counties Carver County, MN, Chippewa County, MN, Hennepin County, MN, Kandiyohi County, MN, McLeod County, MN, Meeker County, MN, Renville County, MN, Wright County, MN

The radar

The Minneapolis radar (KMPX), 100 km from the middle of the area, began a volume at 06:56 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 00:00Z, 7.0 hours before the alert went out and 97 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 00:00Z on 2018-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2018-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1687 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
212 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Sep 18, 2:48 AM CDTMesoscale DiscussionSPCLincoln, Lyon, Murray, Nobles, Pipestone, Rock2 hr
Sep 18, 5:48 AM CDTMesoscale DiscussionSPCBlue Earth, Brown, Cottonwood, Jackson, Lincoln, Lyon and 9 more2 hr

Nearby

Mesoscale Discussions in Minnesota, 2018Every mesoscale discussion in 2018

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.