Alert archive / Oklahoma / Mesoscale Discussions in 2017

Mesoscale Discussion 1513

August 16, 2017Benton County, Arkansas; Barry County, McDonald County, Newton County, Missouri; 30 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Aug 16, 2017, 9:55 PM CDT for Benton County, Arkansas; Barry County, McDonald County, Newton County, Missouri; 30 counties in Oklahoma. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Aug 16, 2017, 9:55 PM CDT (02:55 UTC)
Expired
Aug 16, 2017, 11:30 PM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 34 counties

Benton County, AR, Barry County, MO, McDonald County, MO, Newton County, MO, Adair County, OK, Caddo County, OK, Canadian County, OK, Cherokee County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Creek County, OK, Delaware County, OK, Garvin County, OK, Grady County, OK, Greer County, OK, Hughes County, OK, Kiowa County, OK, Lincoln County, OK, Mayes County, OK, McClain County, OK, McIntosh County, OK, Muskogee County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Ottawa County, OK, Pottawatomie County, OK, Rogers County, OK, Seminole County, OK, Stephens County, OK, Tillman County, OK, Tulsa County, OK, Wagoner County, OK

The radar

The Norman radar (KTLX), 42 km from the middle of the area, began a volume at 02:58 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

Norman, OK (KOUN), launched 00:00Z, 2.9 hours before the alert went out and 57 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, Norman, OK at 00:00Z on 2017-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2168 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, Norman, OK at 00:00Z on 2017-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 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
2168 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
1105 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
180 m²/s²
Significant tornado parameter
0.9
Supercell composite
9.2

Open this sounding in Storm Lab

The text

As transmitted.

367 
ACUS11 KWNS 170255
SWOMCD
SPC MCD 170255 
MOZ000-ARZ000-OKZ000-170430-

Mesoscale Discussion 1513
NWS Storm Prediction Center Norman OK
0955 PM CDT Wed Aug 16 2017

Areas affected...Southwest into northeast OK...Far southwest
MO...Northwest AR

Concerning...Severe Thunderstorm Watch 453...

Valid 170255Z - 170430Z

The severe weather threat for Severe Thunderstorm Watch 453
continues.

SUMMARY...A lingering damaging wind risk continues with the line of
thunderstorms moving into the I-44 corridor, but the severe threat
should diminish with time late tonight.

DISCUSSION...The persistent band of thunderstorms that developed
earlier across KS/OK is moving steadily southeastward this evening,
with the strongest convection noted across portions of southwest
into central OK as of 0245Z. Outflow has advanced several miles
ahead of the primary convection across most of the band, though
stronger cells are noted near boundary inflections to the west and
northeast of the OKC metro. This band earlier produced several
measured severe wind gusts across northern OK, and some
damaging-wind risk will continue for the next 1-2 hours, especially
in areas where convection remains rooted near the composite outflow.

A gradual decreasing trend is expected with time late tonight, as
SBCINH increases and convection moves southeastward into a
less-sheared environment. The extended expiration time of 05Z for WW
453 should be sufficient to cover most of the remaining severe
threat across OK. Convection will also spread further east into
southwest MO and northwest AR with time, but weaker instability in
this area should limit the severe threat.

..Dean.. 08/17/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...SGF...TSA...OUN...

LAT...LON   34859980 35909732 36579589 36929461 37019354 36369351
            35939442 35359559 34749688 34429770 34279840 34299878
            34529929 34859980

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 16, 7:30 PM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Cass, Cedar, Dade and 13 more90 min
Aug 17, 4:29 PM CDTMesoscale DiscussionSPCCimarron, Texas91 min

Nearby

Mesoscale Discussions in Oklahoma, 2017Mesoscale Discussions in Missouri, 2017Mesoscale Discussions in Arkansas, 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.