Alert archive / Tennessee / Mesoscale Discussions in 2012
Mesoscale Discussion 1780
The Storm Prediction Center issued this mesoscale discussion at Aug 16, 2012, 9:26 PM CDT for 17 counties in Kentucky; 47 counties in Tennessee. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 16, 2012, 9:26 PM CDT (02:26 UTC)
- Expired
- Aug 17, 2012, 12:00 AM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 64 counties
Adair County, KY, Allen County, KY, Barren County, KY, Christian County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Green County, KY, Hart County, KY, Logan County, KY, Metcalfe County, KY, Monroe County, KY, Russell County, KY, Simpson County, KY, Todd County, KY, Warren County, KY, Wayne County, KY, Bedford County, TN, Benton County, TN, Bledsoe County, TN, Cannon County, TN, Carroll County, TN, Cheatham County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Grundy County, TN, Henderson County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Lewis County, TN, Macon County, TN, Marshall County, TN, Maury County, TN, Meigs County, TN, Montgomery County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Williamson County, TN, Wilson County, TN
The nearest sounding before it
Nashville Metro, TN (KBNA), launched 00:00Z, 2.4 hours before the alert went out and 13 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
- 1468 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 1539 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 17 m²/s²
- 0-3 km storm-relative helicity
- 106 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
360
ACUS11 KWNS 170226
SWOMCD
SPC MCD 170226
TNZ000-KYZ000-170500-
MESOSCALE DISCUSSION 1780
NWS STORM PREDICTION CENTER NORMAN OK
0926 PM CDT THU AUG 16 2012
AREAS AFFECTED...SRN KY...MUCH OF MIDDLE TN
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 170226Z - 170500Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...SOME SEVERE THREAT WILL PERSIST SE OF WW 583 ACROSS CNTRL
KY AND INTO TN. A WATCH IS POSSIBLE BUT NOT CERTAIN.
DISCUSSION...RADAR SHOWS A LINE OF STORMS PROPAGATING SSEWD ACROSS
SRN KY...AND WILL APPROACH THE NASHVILLE AREA BY ABOUT 330Z WITH
GUSTY WINDS. OTHER MORE CELLULAR ACTIVITY EXISTS ACROSS WRN/MIDDLE
TN WITH A THREAT OF HAIL. EVEN THE CELLULAR ACTIVITY WAS SHOWING A
PROPENSITY TO PRODUCE OUTFLOW.
THE 00Z BNA SOUNDING SHOWED AMPLE INSTABILITY...BUT VERY WEAK LOW TO
MIDLEVEL FLOW. AS THE MAIN LINE OF STORMS CONTINUES SWD...IT WILL
ENCOUNTER LESS FLOW AND EVENTUALLY OUTFLOW MAY OUTRUN THE
STORMS...ENDING THE THREAT. THIS MIGHT OCCUR ACROSS SRN TN LATER
THIS EVENING. GIVEN CONTINUED COOLING OF THE BOUNDARY LAYER...A
GRADUAL WEAKENING OF THE STORMS IS ANTICIPATED.
..JEWELL/THOMPSON.. 08/17/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MRX...JKL...LMK...OHX...HUN...PAH...MEG...
LAT...LON 35738900 36018837 36448791 36878763 37078660 37318603
37328536 36848451 35988439 35568465 35228579 35298688
35398798 35738900Nearby
Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Kentucky, 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.