Alert archive / Kentucky / Mesoscale Discussions in 2012
Mesoscale Discussion 997
The Storm Prediction Center issued this mesoscale discussion at May 31, 2012, 1:56 PM CDT for 5 states. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- May 31, 2012, 1:56 PM CDT (18:56 UTC)
- Expired
- May 31, 2012, 3:00 PM CDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 84 counties
Gallatin County, IL, Hardin County, IL, Massac County, IL, Clark County, IN, Crawford County, IN, Daviess County, IN, Dubois County, IN, Floyd County, IN, Gibson County, IN, Greene County, IN, Harrison County, IN, Jackson County, IN, Lawrence County, IN, Martin County, IN, Orange County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Scott County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Washington County, IN, Adair County, KY, Allen County, KY, Anderson County, KY, Ballard County, KY, Barren County, KY, Boyle County, KY, Breckinridge County, KY, Bullitt County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Casey County, KY, Christian County, KY, Clinton County, KY, Crittenden County, KY, Cumberland County, KY, Daviess County, KY, Edmonson County, KY, Graves County, KY, Grayson County, KY, Green County, KY, Hancock County, KY, Hardin County, KY, Hart County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Jefferson County, KY, Larue County, KY, Lincoln County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marion County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Meade County, KY, Mercer County, KY, Metcalfe County, KY, Monroe County, KY, Muhlenberg County, KY, Nelson County, KY, Ohio County, KY, Oldham County, KY, Russell County, KY, Shelby County, KY, Spencer County, KY, Taylor County, KY, Todd County, KY, Trimble County, KY, Union County, KY, Warren County, KY, Washington County, KY, Webster County, KY, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Lake County, TN
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Nashville Metro, TN (KBNA), launched 12:00Z, 6.9 hours before the alert went out and 154 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1645 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 24 m²/s²
- 0-3 km storm-relative helicity
- 126 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
931
ACUS11 KWNS 311857
SWOMCD
SPC MCD 311856
KYZ000-INZ000-ILZ000-MOZ000-TNZ000-ARZ000-312000-
MESOSCALE DISCUSSION 0997
NWS STORM PREDICTION CENTER NORMAN OK
0156 PM CDT THU MAY 31 2012
AREAS AFFECTED...SERN MO...WRN/CNTRL KY...SRN IL...SRN IND
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 311856Z - 312000Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...AREA IS BEING MONITORED FOR A POSSIBLE WW. SHOULD STORMS
BECOME MORE ORGANIZED...DMGG WINDS AND HAIL MAY BE POSSIBLE.
DISCUSSION...AN MCV OVER SRN IL IS CONTINUING EWD...WITH
THUNDERSTORMS BEGINNING TO INCREASE IN COVERAGE ALONG THE LEADING
EDGE...AND IN RESPONSE TO FORCING FOR ASCENT WITH THE APPROACHING
UPPER TROUGH. SURFACE-BASED INSTABILITY HAS BEEN SOMEWHAT LIMITED
AHEAD OF THIS FEATURE...LARGELY DUE TO MARGINAL DEW POINT VALUES IN
THE 50S...THOUGH A FEW LOWER TO MID 60S VALUES WERE NOTED IN SRN IL
AND ERN MO. GIVEN WARM/MOIST ADVECTION REGIME...IT IS POSSIBLE THAT
SUFFICIENT DESTABILIZATION CAN OCCUR IN ADVANCE OF THE ONGOING
COMPLEX TO WARRANT A WW ISSUANCE AS SMALL BOWING SEGMENTS AND
POTENTIALLY WEAK SUPERCELLS DEVELOP...GIVEN INCREASINGLY FAVORABLE
DEEP-LAYER SHEAR PROFILES...PARTICULARLY INVOF A WARM FRONT ACROSS
SRN IL/IND AND CNTRL KY. HOWEVER...LIMITED INSTABILITY MAY HINDER A
MORE SUBSTANTIAL SEVERE WEATHER THREAT. TRENDS WILL CONTINUE TO BE
MONITORED.
..HURLBUT/WEISS.. 05/31/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...JKL...LMK...IND...PAH...MEG...
LAT...LON 36018960 36069029 36668977 37358857 38198812 38678728
39088701 39098580 37898465 37248452 36678509 36768649
36838814 36608819 36578940 36018960SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 31, 2:34 PM CDT | Severe Thunderstorm Watch | SPC | Massac | 6 hr |
| May 31, 5:30 PM CDT | Mesoscale Discussion | SPC | Floyd, Harrison | 2 hr |
| May 30, 7:32 PM CDT | Severe Thunderstorm Watch | SPC | Barry, Barton, Jasper, Lawrence, McDonald, Newton and 1 more | 8 hr |
| May 30, 11:21 PM CDT | Mesoscale Discussion | SPC | Barry, McDonald, Newton | 114 min |
| May 31, 1:52 AM CDT | Mesoscale Discussion | SPC | McDonald | 83 min |
| May 31, 11:59 AM CDT | Mesoscale Discussion | SPC | Dunklin, Pemiscot | 61 min |
| May 31, 12:59 PM CDT | Severe Thunderstorm Watch | SPC | Dunklin, Pemiscot | 6 hr |
| May 31, 2:38 PM CDT | Mesoscale Discussion | SPC | Carroll, Chester, Crockett, Dyer, Fayette, Gibson and 9 more | 67 min |
| May 31, 6:00 PM CDT | Severe Thunderstorm Watch | SPC | Bedford, Benton, Cheatham, Clay, Davidson, Dickson and 23 more | 4 hr |
Nearby
Mesoscale Discussions in Kentucky, 2012Mesoscale Discussions in Indiana, 2012Mesoscale Discussions in Missouri, 2012Every mesoscale discussion in 2012
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.