Alert archive / Indiana / Mesoscale Discussions in 2021

Mesoscale Discussion 1860

October 14, 202128 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Oct 14, 2021, 4:49 PM EDT for 28 counties in Indiana. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
Oct 14, 2021, 4:49 PM EDT (20:49 UTC)
Expired
Oct 14, 2021, 6:15 PM EDT
In force
86 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%
All 28 counties

Allen County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clay County, IN, Clinton County, IN, DeKalb County, IN, Fountain County, IN, Grant County, IN, Hamilton County, IN, Hendricks County, IN, Howard County, IN, Huntington County, IN, Kosciusko County, IN, Miami County, IN, Montgomery County, IN, Noble County, IN, Parke County, IN, Putnam County, IN, Steuben County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Wabash County, IN, Wells County, IN, Whitley County, IN

The radar

The Indianapolis radar (KIND), 78 km from the middle of the area, began a volume at 20:49 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

Lincoln, IL (KILX), launched 12:00Z, 8.8 hours before the alert went out and 207 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, Lincoln, IL at 12:00Z on 2021-10-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Lincoln, IL at 12:00Z on 2021-10-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -99 square meters per square second.1939587897Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
852 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
-99 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

347 
ACUS11 KWNS 142050
SWOMCD
SPC MCD 142049 
OHZ000-INZ000-ILZ000-142215-

Mesoscale Discussion 1860
NWS Storm Prediction Center Norman OK
0349 PM CDT Thu Oct 14 2021

Areas affected...portions of northern IN

Concerning...Severe potential...Watch unlikely 

Valid 142049Z - 142215Z

Probability of Watch Issuance...5 percent

SUMMARY...Scattered storms may undergo brief intensification with a
risk for isolated damaging wind gusts into this evening. Given
expected sparse severe coverage, a watch is not likely.

DISCUSSION...As of 2030 UTC, regional radar imagery showed a cluster
of thunderstorms ongoing along a cold front across west-central IN.
Ahead of the front, weak destabilization (500-1000 J/kg of MLCAPE)
from cloud breaks may support a brief uptick in convective intensity
over the next couple of hours. Regional model soundings show
deep-layer shear profiles remain relatively strong around 40-50 kts.
Shear remains mostly parallel to the cold front, supporting a linear
mode behind the wind shift. However, the southern most sections of
the cluster, including a weakly rotating cell over Parke County, IN,
appear to be ahead of the cooler air suggesting relatively greater
potential for damaging wind gusts. Overall hi-res guidance remains
uncertain on convective evolution casting considerable doubt on the
coverage of any severe weather. However, given the strong shear and
sufficient buoyancy, a few isolated damaging wind gusts cannot be
ruled out.

..Lyons/Dial.. 10/14/2021

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

ATTN...WFO...IWX...IND...ILX...

LAT...LON   40708499 40008597 39488677 39268739 39428760 39748755
            40128734 40768661 41668527 41728490 41298477 40708499

Nearby

Mesoscale Discussions in Indiana, 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.