Alert archive / Kansas / Mesoscale Discussions in 2021

Mesoscale Discussion 1683

September 2, 20218 counties in Kansas

The Storm Prediction Center issued this mesoscale discussion at Sep 2, 2021, 2:11 PM CDT for 8 counties in Kansas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 2, 2021, 2:11 PM CDT (19:11 UTC)
Expired
Sep 2, 2021, 4:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
40%

Counties Dickinson County, KS, Geary County, KS, Ottawa County, KS, Pottawatomie County, KS, Riley County, KS, Saline County, KS, Shawnee County, KS, Wabaunsee County, KS

The radar

The Topeka radar (KTWX), 64 km from the middle of the area, began a volume at 19:11 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 7.2 hours before the alert went out and 115 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, Topeka, KS at 12:00Z on 2021-09-02Temperature 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, Topeka, KS at 12:00Z on 2021-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 136 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
925 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
136 m²/s²
0-3 km storm-relative helicity
228 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

205 
ACUS11 KWNS 021912
SWOMCD
SPC MCD 021911 
KSZ000-022115-

Mesoscale Discussion 1683
NWS Storm Prediction Center Norman OK
0211 PM CDT Thu Sep 02 2021

Areas affected...northeast Kansas

Concerning...Severe potential...Watch possible 

Valid 021911Z - 022115Z

Probability of Watch Issuance...40 percent

SUMMARY...Isolated severe storms in the Salina Kansas area may
persist for a few hours into northeast Kansas. Wind, hail, and
perhaps a tornado threat are all possible.

DISCUSSION...Storms on the southern fringe of a larger-scale
precipitation shield from NE into northern KS have increased in
intensity as a hotter air mass develops to the south. Surface
analysis shows temperatures into the 90s F across south-central KS,
which has eroded capping. Downstream of these cells, temperatures
are quite a bit cooler, only in the lower 80s around Topeka,
although a warming trend is expected. Cirrus is currently hampering
heating across northeast KS as well.

Given the robustness of the current cell, a severe hail or wind
threat may persist in a narrow zone across several counties over the
next few hours. In addition, shear profiles are favorable for
supercells, and 0-1 SRH will remain over 100 m2/s2 which could also
favor a tornado risk assuming cells remain discrete.

..Jewell/Grams.. 09/02/2021

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

ATTN...WFO...TOP...ICT...

LAT...LON   39069798 39539626 39449589 39169571 38949577 38839609
            38799716 38739789 38809799 38919802 39069798

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 2, 1:28 PM CDTMesoscale DiscussionSPCDecatur, Graham, Norton, Phillips, Sheridan2 hr
Sep 2, 4:23 PM CDTMesoscale DiscussionSPCBarton, Clark, Clay, Cloud, Dickinson, Edwards and 16 more97 min
Sep 2, 5:27 PM CDTTornado WatchSPCBarton, Clay, Cloud, Dickinson, Ellis, Ellsworth and 27 more5 hr

Nearby

Mesoscale Discussions in Kansas, 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.