Alert archive / Tennessee / Mesoscale Discussions in 2016
Mesoscale Discussion 1850
The Storm Prediction Center issued this mesoscale discussion at Nov 29, 2016, 11:17 PM CST for 6 counties in Alabama; 4 counties in Georgia; 7 counties in Tennessee. It was in force for 118 min.
The area
The outline as issued.
The facts
- Issued
- Nov 29, 2016, 11:17 PM CST (05:17 UTC)
- Expired
- Nov 30, 2016, 1:15 AM CST
- In force
- 118 min
- Issued by
- the Storm Prediction Center
Counties DeKalb County, AL, Jackson County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Morgan County, AL, Catoosa County, GA, Dade County, GA, Walker County, GA, Whitfield County, GA, Bradley County, TN, Franklin County, TN, Grundy County, TN, Hamilton County, TN, Lincoln County, TN, Marion County, TN, Sequatchie County, TN
The radar
The Northeast Alabama radar (KHTX), 16 km from the middle of the area, began a volume at 05:17 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
Nashville Metro, TN (KBNA), launched 00:00Z, 5.3 hours before the alert went out and 157 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
- 1648 m above ground
- 0-6 km bulk shear
- 90 kt
- 0-1 km storm-relative helicity
- 321 m²/s²
- 0-3 km storm-relative helicity
- 354 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
941
ACUS11 KWNS 300518
SWOMCD
SPC MCD 300517
TNZ000-GAZ000-ALZ000-300715-
MESOSCALE DISCUSSION 1850
NWS STORM PREDICTION CENTER NORMAN OK
1117 PM CST TUE NOV 29 2016
AREAS AFFECTED...PORTIONS OF SOUTHERN TN...NORTHERN AL...NORTHWEST GA
CONCERNING...TORNADO WATCH 507...509...510
VALID 300517Z - 300715Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 507...509...510 CONTINUES.
SUMMARY...THE SEVERE-THUNDERSTORM/TORNADO RISK CONTINUES ACROSS
TORNADO WATCHES 507...509...AND 510.
DISCUSSION...ONGOING SUPERCELL THUNDERSTORMS/CLUSTERS CONTINUE
TRACKING NORTHEASTWARD WITHIN A ZONE OF MODEST WARM ADVECTION ACROSS
PORTIONS OF THE TENNESSEE VALLEY REGION AND VICINITY. ADDITIONAL
CONVECTION IN MS WILL ALSO ADVANCE INTO PORTIONS OF THE AREA DURING
THE NEXT SEVERAL HOURS. LOW-LEVEL SOUTHERLIES WILL CONTINUE TO
ENCOURAGE MOIST/UNSTABLE INFLOW FOR THE CONVECTION. MIDDLE 60S
SURFACE DEWPOINTS...CHARACTERIZING THE MOIST BOUNDARY LAYER FEEDING
THIS CONVECTION...ARE SUPPORTING AROUND 250-750 J/KG OF MLCAPE --
STRONGEST FROM NORTH-CENTRAL INTO NORTHEAST AL AND FAR NORTHWEST GA.
SUBSTANTIALLY ELONGATED HODOGRAPHS FEATURING LOW-LEVEL CURVATURE
WILL CONTINUE SUPPORTING TORNADIC-SUPERCELL POTENTIAL THROUGH THE
OVERNIGHT HOURS. DAMAGING STRAIGHT-LINE WINDS WILL ALSO BE POSSIBLE...
AS HIGH-MOMENTUM AIR ABOVE THE GROUND MAY BE TRANSFERRED TO THE
SURFACE IN STRONGER DOWNDRAFTS.
REMAINING-VALID PORTIONS OF WATCH 507 IN PORTIONS OF SOUTHERN TN
SHOULD BE ALLOWED TO EXPIRE BY 06Z...AS THE MORE SUBSTANTIAL SEVERE
RISK WILL EXIST FARTHER SOUTH/EAST.
..COHEN.. 11/30/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MRX...FFC...OHX...BMX...HUN...
LAT...LON 34338582 34378750 34618782 35158679 35588510 35208472
34748492 34338582SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 29, 6:43 PM CST | Mesoscale Discussion | SPC | Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 6 more | 92 min |
| Nov 29, 6:47 PM CST | Tornado Watch | SPC | Cullman, DeKalb, Jackson, Lawrence, Limestone, Madison and 2 more | 8 hr |
| Nov 29, 8:03 PM CST | Mesoscale Discussion | SPC | Choctaw, Fayette, Greene, Hale, Lamar, Pickens and 2 more | 2 hr |
| Nov 29, 8:50 PM CST | Tornado Watch | SPC | Bibb, Blount, Fayette, Greene, Hale, Jefferson and 7 more | 8 hr |
| Nov 29, 9:28 PM CST | Mesoscale Discussion | SPC | Cullman, DeKalb, Jackson, Lawrence, Limestone, Madison and 2 more | 62 min |
| Nov 29, 10:28 PM CST | Tornado Watch | SPC | Colbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more | 5 hr |
| Nov 29, 11:37 PM CST | Mesoscale Discussion | SPC | Fayette, Lamar, Pickens | 113 min |
| Nov 30, 1:07 AM CST | Mesoscale Discussion | SPC | Blount, Cullman, DeKalb, Fayette, Jackson, Madison and 5 more | 53 min |
| Nov 30, 2:54 AM CST | Tornado Watch | SPC | Bibb, Blount, Calhoun, Cherokee, Chilton, Cleburne and 22 more | 7 hr |
| Nov 30, 4:57 AM CST | Tornado Watch | SPC | Choctaw, Clarke, Mobile, Washington | 7 hr |
| Nov 30, 5:10 AM CST | Mesoscale Discussion | SPC | Bibb, Blount, Calhoun, Cherokee, Chilton, Clay and 27 more | 95 min |
| Nov 30, 9:00 AM CST | Mesoscale Discussion | SPC | Autauga, Baldwin, Bibb, Blount, Bullock, Butler and 37 more | 2 hr |
| Nov 30, 11:06 AM CST | Tornado Watch | SPC | Baldwin, Barbour, Bullock, Butler, Chambers, Coffee and 17 more | 6 hr |
| Nov 30, 12:59 PM CST | Mesoscale Discussion | SPC | Barbour, Bullock, Coffee, Covington, Crenshaw, Dale and 7 more | 2 hr |
| Nov 30, 1:55 PM CST | Mesoscale Discussion | SPC | Barbour, Coffee, Covington, Dale, Geneva, Henry and 2 more | 2 hr |
| Nov 29, 10:11 PM CST | Tornado Watch | SPC | Catoosa, Chattooga, Dade, Walker, Whitfield | 5 hr |
| Nov 30, 2:23 PM CST | Severe Thunderstorm Watch | SPC | Baldwin, Bibb, Bleckley, Columbia, Crisp, Dooly and 22 more | 3 hr |
| Nov 30, 4:43 PM CST | Mesoscale Discussion | SPC | Columbia, Elbert, Glascock, Hancock, Lincoln, McDuffie and 5 more | 92 min |
| Nov 30, 4:45 PM CST | Mesoscale Discussion | SPC | Baker, Calhoun, Decatur, Dougherty, Early, Grady and 7 more | 30 min |
| Nov 29, 11:46 PM CST | Mesoscale Discussion | SPC | Anderson, Blount, Campbell, Claiborne, Grainger, Hamblen and 6 more | 119 min |
Nearby
Mesoscale Discussions in Tennessee, 2016Mesoscale Discussions in Alabama, 2016Mesoscale Discussions in Georgia, 2016Every mesoscale discussion in 2016
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.