Alert archive / Kansas / Mesoscale Discussions in 2021
Mesoscale Discussion 1708
The Storm Prediction Center issued this mesoscale discussion at Sep 7, 2021, 3:42 PM CDT for 4 states. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 7, 2021, 3:42 PM CDT (20:42 UTC)
- Expired
- Sep 7, 2021, 6:15 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
All 26 counties
Allen County, KS, Bourbon County, KS, Chautauqua County, KS, Cowley County, KS, Crawford County, KS, Elk County, KS, Labette County, KS, Linn County, KS, Montgomery County, KS, Neosho County, KS, Wilson County, KS, Woodson County, KS, Bates County, MO, Alfalfa County, OK, Blaine County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grant County, OK, Kay County, OK, Major County, OK, Noble County, OK, Osage County, OK, Roger Mills County, OK, Woodward County, OK, Hemphill County, TX
The radar
The Vance AFB radar (KVNX), 65 km from the middle of the area, began a volume at 20:40 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 12:00Z, 8.7 hours before the alert went out and 244 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.
- Mixed-layer CAPE
- 837 J/kg
- Mixed-layer CIN
- -341 J/kg
- Mixed-layer LCL
- 2165 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 210 m²/s²
- 0-3 km storm-relative helicity
- 268 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
684
ACUS11 KWNS 072043
SWOMCD
SPC MCD 072042
MOZ000-KSZ000-OKZ000-TXZ000-072315-
Mesoscale Discussion 1708
NWS Storm Prediction Center Norman OK
0342 PM CDT Tue Sep 07 2021
Areas affected...Northern OK/southeastern KS and vicinity
Concerning...Severe potential...Watch unlikely
Valid 072042Z - 072315Z
Probability of Watch Issuance...20 percent
SUMMARY...Widely scattered thunderstorm development is expected
along and just ahead of a cold front, with the potential for
isolated 50-65 mph gusts and hail near 1 inch diameter, beginning
22-00z and persisting through about 02-03z.
DISCUSSION...Strong surface heating/mixing along and just ahead of a
southeastward-moving cold front is weakening convective inhibition
and boosting MLCAPE to 2000-3000 J/kg from northern OK into
southeastern KS and vicinity. Some cumulus development is noted
near the front in east central KS and near the TX/northwest OK
border, and storm development will become more probable by 22z as
these trends continue. The moderate-strong buoyancy and modest
deep-layer northerly shear will favor a few semi-organized
cells/small clusters with isolated large hail near 1" diameter.
Steepening low-level lapse rates and DCAPE in excess of 1500 J/kg
will be favorable for isolated downburst winds of 50-65 mph for a
few hours late this afternoon into late evening.
..Thompson/Hart.. 09/07/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN...AMA...
LAT...LON 35799851 35549998 35660055 35990054 36170016 36989778
37679623 38519453 38489422 38189412 37459464 36509655
35799851SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 7, 2:09 PM CDT | Mesoscale Discussion | SPC | El Paso | 3 hr |
Nearby
Mesoscale Discussions in Kansas, 2021Mesoscale Discussions in Oklahoma, 2021Mesoscale Discussions in Missouri, 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.