Alert archive / Iowa / Mesoscale Discussions in 2017

Mesoscale Discussion 1697

October 6, 201717 counties in Iowa; Atchison County, Nodaway County, Missouri; Cass County, Nemaha County, Otoe County, Nebraska

The Storm Prediction Center issued this mesoscale discussion at Oct 6, 2017, 8:23 PM CDT for 17 counties in Iowa; Atchison County, Nodaway County, Missouri; Cass County, Nemaha County, Otoe County, Nebraska. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Oct 6, 2017, 8:23 PM CDT (01:23 UTC)
Expired
Oct 6, 2017, 10:00 PM CDT
In force
97 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 22 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Cass County, IA, Dallas County, IA, Fremont County, IA, Guthrie County, IA, Madison County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Pottawattamie County, IA, Ringgold County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Atchison County, MO, Nodaway County, MO, Cass County, NE, Nemaha County, NE, Otoe County, NE

The radar

The Des Moines radar (KDMX), 119 km from the middle of the area, began a volume at 01:24 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

Omaha, NE (KOAX), launched 00:00Z, 1.4 hours before the alert went out and 130 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, Omaha, NE at 00:00Z on 2017-10-07Temperature 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, Omaha, NE at 00:00Z on 2017-10-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 square meters per square second.1939587897Sfc1 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
571 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
374 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.9

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
Oct 6, 9:54 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Dallas, Fremont and 11 more96 min
Oct 7, 4:40 PM CDTMesoscale DiscussionSPCCape Girardeau, Mississippi, Scott3 hr

Nearby

Mesoscale Discussions in Iowa, 2017Mesoscale Discussions in Nebraska, 2017Mesoscale Discussions in Missouri, 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; radar from the NEXRAD Level II archive.