Alert archive / Tennessee / Mesoscale Discussions in 2011
Mesoscale Discussion 679
The Storm Prediction Center issued this mesoscale discussion at May 1, 2011, 3:50 AM CDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 1, 2011, 3:50 AM CDT (08:50 UTC)
- Expired
- May 1, 2011, 6:15 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 74 counties
Lee County, AR, Monroe County, AR, Phillips County, AR, Adair County, KY, Allen County, KY, Barren County, KY, Casey County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Green County, KY, Hart County, KY, Larue County, KY, Logan County, KY, Marion County, KY, Metcalfe County, KY, Monroe County, KY, Pulaski County, KY, Rockcastle County, KY, Russell County, KY, Simpson County, KY, Taylor County, KY, Todd County, KY, Warren County, KY, Wayne County, KY, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Marshall County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Bedford County, TN, Benton County, TN, Cannon County, TN, Cheatham County, TN, Chester County, TN, Clay County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Fayette County, TN, Fentress County, TN, Hardeman County, TN, Hardin County, TN, Henderson County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Macon County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Rutherford County, TN, Shelby County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Warren County, TN, Wayne County, TN, White County, TN, Williamson County, TN, Wilson County, TN
The radar
The Memphis radar (KNQA), 141 km from the middle of the area, began a volume at 08:53 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
Nashville Metro, TN (KBNA), launched 00:00Z, 8.8 hours before the alert went out and 167 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
- 2308 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 76 m²/s²
- 0-3 km storm-relative helicity
- 135 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
204
ACUS11 KWNS 010850
SWOMCD
SPC MCD 010850
KYZ000-TNZ000-ALZ000-MSZ000-ARZ000-011115-
MESOSCALE DISCUSSION 0679
NWS STORM PREDICTION CENTER NORMAN OK
0350 AM CDT SUN MAY 01 2011
AREAS AFFECTED...PORTIONS SRN/ERN KY...EXTREME ERN AR...NRN
MS...WRN/MIDDLE TN.
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 010850Z - 011115Z
AS OF 830Z...QUASI-LINEAR MCS WAS EVIDENT FROM CENTRAL KY SW
LEX...SWWD ACROSS MEM AREA TO E-CENTRAL AR. MCS SHOULD CONTINUE
MOVING EWD APPROXIMATELY 25-30 KT OVER PORTIONS CENTRAL/ERN KY AND
WRN/MID TN...WITH EMBEDDED/SEGMENTED ELEMENTS AND BOWS MOVING ENEWD
40-45 KT. INTERMITTENT POTENTIAL EXISTS FOR GUSTS TO NEAR 50-KT SVR
LIMITS. SVR POTENTIAL APPEARS TOO MRGL/SPORADIC FOR WW.
ACTIVITY WILL REMAIN AHEAD OF SFC COLD FRONT OVER MO/AR/NE TX...AND
IS EXPECTED TO MOVE OVER PROGRESSIVELY MORE STABLE SFC AIR MASS WITH
TIME AND WITH EWD EXTENT...THROUGH REMAINDER PRE-DAWN HOURS.
HOWEVER...JUST ABOVE SFC...VEERING/SWLY ERN BRANCH OF LLJ WAS
EVIDENT IN VWP/PROFILER DATA. RELATED WAA AND MOIST ADVECTION
AROUND 850 MB WILL CONTRIBUTE SUFFICIENT THETAE TO SUSTAIN ELEVATED
INFLOW PARCELS WITH MUCAPE IN 800-1200 J/KG RANGE...BASED ON
MODIFIED RAOBS AND RUC SOUNDINGS. BENEATH THAT INFLOW
REGION...RELATIVELY DRY LAYER CLOSER TO SFC IS MORE STABLE BUT MAY
SUPPORT POTENTIAL FOR MOST INTENSE DOWNDRAFT GUSTS TO PENETRATE TO
SFC IN NEAR-SVR FORM.
..EDWARDS.. 05/01/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MRX...JKL...LMK...OHX...HUN...PAH...MEG...LZK...
LAT...LON 34719141 35298975 36078808 37048706 37648563 37348417
35748542 35018806 34418975 34409126 34719141SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 7:49 PM CDT | Mesoscale Discussion | SPC | Clay, Greene, Izard, Lawrence, Randolph, Sharp and 1 more | 56 min |
| Apr 30, 8:47 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clark, Conway, Faulkner, Garland, Grant and 12 more | 58 min |
| Apr 30, 9:26 PM CDT | Mesoscale Discussion | SPC | Hempstead, Howard, Little River, Miller, Sevier | 64 min |
| Apr 30, 11:39 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clark, Cleburne, Conway, Craighead, Cross and 31 more | 66 min |
| May 1, 1:16 AM CDT | Mesoscale Discussion | SPC | Arkansas, Clark, Cleburne, Conway, Craighead, Crittenden and 37 more | 59 min |
| May 1, 8:30 AM CDT | Mesoscale Discussion | SPC | Clark, Dallas, Garland, Hempstead, Hot Spring, Howard and 9 more | 30 min |
| May 1, 8:45 AM CDT | Severe Thunderstorm Watch | SPC | Clark, Columbia, Dallas, Garland, Hempstead, Hot Spring and 10 more | 6 hr |
| May 1, 12:12 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 34 more | 93 min |
| May 1, 12:47 PM CDT | Tornado Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 27 more | 8 hr |
| May 1, 3:18 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 37 more | 87 min |
| May 1, 5:42 PM CDT | Mesoscale Discussion | SPC | Clark, Dallas, Garland, Grant, Hempstead, Hot Spring and 14 more | 3 hr |
| May 1, 5:43 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 37 more | 92 min |
Nearby
Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Kentucky, 2011Mesoscale Discussions in Mississippi, 2011Every mesoscale discussion in 2011
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.