Alert archive / North Dakota / Mesoscale Discussions in 2017

Mesoscale Discussion 1336

July 18, 20175 counties in North Dakota; 5 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 18, 2017, 4:01 AM CDT for 5 counties in North Dakota; 5 counties in South Dakota. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Jul 18, 2017, 4:01 AM CDT (09:01 UTC)
Expired
Jul 18, 2017, 5:30 AM CDT
In force
89 min
Issued by
the Storm Prediction Center
Chance of a watch
5%

Counties Dickey County, ND, LaMoure County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Brown County, SD, Day County, SD, Edmunds County, SD, Marshall County, SD, McPherson County, SD

The radar

The Aberdeen radar (KABR), 63 km from the middle of the area, began a volume at 09:02 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

Aberdeen, SD (KABR), launched 00:00Z, 9.0 hours before the alert went out and 125 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, Aberdeen, SD at 00:00Z on 2017-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 486 joules per kilogram.LCLEL10008507005003002001001 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, Aberdeen, SD at 00:00Z on 2017-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 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
486 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
3095 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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 18, 3:22 PM CDTMesoscale DiscussionSPCButte, Lawrence2 hr

Nearby

Mesoscale Discussions in North Dakota, 2017Mesoscale Discussions in South Dakota, 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.