Alert archive / Kansas / Mesoscale Discussions in 2021

Mesoscale Discussion 481

May 2, 202110 counties in Kansas; Red Willow County, Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 2, 2021, 7:04 PM CDT for 10 counties in Kansas; Red Willow County, Nebraska. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
May 2, 2021, 7:04 PM CDT (00:04 UTC)
Expired
May 2, 2021, 8:30 PM CDT
In force
86 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 126

Counties Decatur County, KS, Gove County, KS, Graham County, KS, Logan County, KS, Norton County, KS, Phillips County, KS, Rooks County, KS, Sheridan County, KS, Thomas County, KS, Trego County, KS, Red Willow County, NE

The radar

The Goodland radar (KGLD), 126 km from the middle of the area, began a volume at 00:06 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, 0.1 hours before the alert went out and 171 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 2021-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1069 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Dodge City, at 00:00Z on 2021-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 110 square meters per square second.1939Sfc1 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
1069 J/kg
Mixed-layer CIN
-146 J/kg
Mixed-layer LCL
1754 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
110 m²/s²
0-3 km storm-relative helicity
394 m²/s²
Significant tornado parameter
0.1
Supercell composite
12.1

Open this sounding in Storm Lab

The text

As transmitted.

802 
ACUS11 KWNS 030005
SWOMCD
SPC MCD 030004 
KSZ000-NEZ000-030130-

Mesoscale Discussion 0481
NWS Storm Prediction Center Norman OK
0704 PM CDT Sun May 02 2021

Areas affected...Portions of far southern NE into northwestern and
north-central KS

Concerning...Severe Thunderstorm Watch 126...

Valid 030004Z - 030130Z

The severe weather threat for Severe Thunderstorm Watch 126
continues.

SUMMARY...The greatest severe/damaging wind threat should focus
across parts of far southern Nebraska into northwestern and
north-central Kansas over the next 1-2 hours.

DISCUSSION...Storms have recently congealed into a line across parts
of northwestern KS and far southern NE along a surface cold front.
Current expectations are for this line to surge east-southeastward
this evening, where MLCAPE around 1500 J/kg, 35-40 kt of deep-layer
shear, and minimal MLCIN should support continued storm organization
and intensity in the short term. Isolated large hail will remain a
concern with any supercell embedded within the line. But, scattered
severe/damaging winds around 60-75 mph will likely be the main
severe threat in the next 1-2 hours across northwestern into
north-central KS given the increasingly linear nature of the
convection and the favorably mixed boundary layer supporting
efficient downdraft accelerations.

..Gleason.. 05/03/2021

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

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

LAT...LON   39180149 40190067 40149989 39869914 39479906 39139920
            38589968 38480054 38640118 39180149

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 8:36 PM CDTMesoscale DiscussionSPCEllis, Finney, Ford, Gove, Graham, Gray and 13 more84 min
May 2, 10:26 PM CDTMesoscale DiscussionSPCBarton, Clark, Comanche, Edwards, Ellsworth, Ford and 9 more94 min

Nearby

Mesoscale Discussions in Kansas, 2021Mesoscale Discussions in Nebraska, 2021Every mesoscale discussion in 2021

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.