Alert archive / Kansas / Mesoscale Discussions in 2018

Mesoscale Discussion 968

June 30, 2018Kit Carson County, Colorado; 18 counties in Kansas; Dundy County, Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jun 30, 2018, 7:18 PM MDT for Kit Carson County, Colorado; 18 counties in Kansas; Dundy County, Nebraska. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Jun 30, 2018, 7:18 PM MDT (01:18 UTC)
Expired
Jun 30, 2018, 9:15 PM MDT
In force
117 min
Issued by
the Storm Prediction Center

Counties Kit Carson County, CO, Cheyenne County, KS, Decatur County, KS, Ellis County, KS, Gove County, KS, Graham County, KS, Lane County, KS, Logan County, KS, Ness County, KS, Norton County, KS, Phillips County, KS, Rawlins County, KS, Rooks County, KS, Rush County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Trego County, KS, Wallace County, KS, Dundy County, NE

The radar

The Goodland radar (KGLD), 75 km from the middle of the area, began a volume at 01:18 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

Dodge City, (KDDC), launched 00:00Z, 1.3 hours before the alert went out and 177 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, Dodge City, at 00:00Z on 2018-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1742 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, Dodge City, at 00:00Z on 2018-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 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
1742 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
1867 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.6

Open this sounding in Storm Lab

The text

As transmitted.

088 
ACUS11 KWNS 010119
SWOMCD
SPC MCD 010118 
KSZ000-NEZ000-COZ000-010315-

Mesoscale Discussion 0968
NWS Storm Prediction Center Norman OK
0818 PM CDT Sat Jun 30 2018

Areas affected...Far northeast Colorado...northwest Kansas

Concerning...Severe Thunderstorm Watch 251...

Valid 010118Z - 010315Z

The severe weather threat for Severe Thunderstorm Watch 251
continues.

SUMMARY...Severe threat continues across WW 0251. Damaging wind
gusts are likely to be the predominant threat, though a brief
tornado or two cannot be ruled out.

DISCUSSION...An outflow dominant supercell cluster in Yuma/Kit
Carson counties Colorado is moving into Cheyenne/Sherman Counties in
Kansas, with an additional supercell ongoing in Graham County,
Kansas. These storms are progressing in an ambient environment
characterized by 1500+ J/kg and 200+ m2/s2 SRH (owing to respectable
low-level directional shear and a developing nocturnal LLJ). As the
LLJ continues to increase in strength, enhanced convergence along
the jet terminus may assist ongoing storms into growing upscale. As
such, damaging winds will be possible with these storms before they
become increasingly elevated due to a nocturnally cooled,
stabilizing boundary layer.

Any storm that can anchor to one of the outflow boundaries present
across Severe Thunderstorm Watch 0251 may produce an isolated, brief
tornado or two before becoming elevated later this evening.

..Squitieri/Gleason/Thompson.. 07/01/2018

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

ATTN...WFO...GID...DDC...GLD...

LAT...LON   39190281 39740266 40210177 40049968 39749918 39249913
            38769912 38429933 38259986 38510062 38860165 39050262
            39190281

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 30, 7:55 PM MDTMesoscale DiscussionSPCAtchison, Brown, Clay, Doniphan, Douglas, Jackson and 14 more95 min
Jun 30, 10:51 PM MDTMesoscale DiscussionSPCBarton, Clay, Cloud, Dickinson, Ellsworth, Geary and 14 more84 min
Jun 30, 11:48 PM MDTMesoscale DiscussionSPCBurt, Butler, Cass, Colfax, Dodge, Douglas and 10 more117 min

Nearby

Mesoscale Discussions in Kansas, 2018Mesoscale Discussions in Colorado, 2018Mesoscale Discussions in Nebraska, 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.