Alert archive / Kansas / Mesoscale Discussions in 2021

Mesoscale Discussion 1747

September 14, 202128 counties in Kansas

The Storm Prediction Center issued this mesoscale discussion at Sep 14, 2021, 3:40 PM CDT for 28 counties in Kansas. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Sep 14, 2021, 3:40 PM CDT (20:40 UTC)
Expired
Sep 14, 2021, 5:15 PM CDT
In force
95 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
60%
All 28 counties

Barber County, KS, Clark County, KS, Comanche County, KS, Cowley County, KS, Edwards County, KS, Finney County, KS, Ford County, KS, Grant County, KS, Gray County, KS, Hamilton County, KS, Harper County, KS, Harvey County, KS, Haskell County, KS, Hodgeman County, KS, Kearny County, KS, Kingman County, KS, Kiowa County, KS, Meade County, KS, Morton County, KS, Pawnee County, KS, Pratt County, KS, Reno County, KS, Sedgwick County, KS, Seward County, KS, Stafford County, KS, Stanton County, KS, Stevens County, KS, Sumner County, KS

The radar

The Dodge City radar (KDDC), 52 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 watches that followed

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

The nearest sounding before it

Dodge City, (KDDC), launched 12:00Z, 8.7 hours before the alert went out and 47 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 12:00Z on 2021-09-14Temperature 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, Dodge City, at 12:00Z on 2021-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 168 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1866 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
168 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

861 
ACUS11 KWNS 142040
SWOMCD
SPC MCD 142040 
KSZ000-OKZ000-COZ000-142215-

Mesoscale Discussion 1747
NWS Storm Prediction Center Norman OK
0340 PM CDT Tue Sep 14 2021

Areas affected...parts of southern KS

Concerning...Severe potential...Watch possible 

Valid 142040Z - 142215Z

Probability of Watch Issuance...60 percent

SUMMARY...Isolated storms capable of large hail are possible this
afternoon into this evening. A severe thunderstorm watch may be
needed in the next couple of hours.

DISCUSSION...An expanding/deepening CU field in the vicinity of a
southward-sagging cold front has been noted over
southwest/south-central KS over the past hour or two. Strong heating
and dewpoints in the low 60s amid steep midlevel lapse rates is
resulting in 1000-2000 J/kg MLCAPE. Large-scale forcing for ascent
remains weak over the region, but weak convergence along the surface
boundary should be sufficient for a few storms to develop over the
next few hours. This area is on the southern fringes of stronger
shear, with effective shear magnitudes around 25-35 kt. Small, but
curved low-level hodographs, becoming straight/elongated above 3 km,
suggest splitting supercells  producing large hail are possible.
Convective trends will be monitored and a watch may be needed in the
next couple of hours.

..Leitman/Thompson.. 09/14/2021

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

ATTN...WFO...ICT...OUN...DDC...AMA...PUB...

LAT...LON   38070194 38240005 38279823 38029704 37669677 37429672
            37059687 36899715 36929859 36920083 36910182 37090223
            37900218 38070194

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 14, 4:04 PM CDTSevere Thunderstorm WatchSPCBarber, Butler, Clark, Comanche, Cowley, Edwards and 23 more7 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.