Alert archive / Tennessee / Mesoscale Discussions in 2004
Mesoscale Discussion 2199
The Storm Prediction Center issued this mesoscale discussion at Sep 12, 2004, 3:41 PM CDT for Colbert County, Lauderdale County, Alabama; 23 counties in Mississippi; 27 counties in Tennessee. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 12, 2004, 3:41 PM CDT (20:41 UTC)
- Expired
- Sep 12, 2004, 5:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 52 counties
Colbert County, AL, Lauderdale County, AL, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Clay County, MS, Grenada County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Leflore County, MS, Marshall County, MS, Monroe County, MS, Montgomery County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Webster County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, Maury County, TN, McNairy County, TN, Perry County, TN, Stewart County, TN, Wayne County, TN, Weakley County, TN, Williamson County, TN
The radar
The Memphis radar (KNQA), 115 km from the middle of the area, began a volume at 20:43 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
Little Rock, AR (KLZK), launched 12:00Z, 8.7 hours before the alert went out and 119 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
- 1709 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 0 m²/s²
- 0-3 km storm-relative helicity
- -11 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
170 ACUS11 KWNS 122044 SWOMCD SPC MCD 122041 TNZ000-ALZ000-KYZ000-MSZ000-122245- MESOSCALE DISCUSSION 2199 NWS STORM PREDICTION CENTER NORMAN OK 0341 PM CDT SUN SEP 12 2004 AREAS AFFECTED...WRN/MIDDLE TN...NRN MS...NW AL CONCERNING...CONVECTIVE TRENDS...SEVERE THUNDERSTORM POTENTIAL VALID 122041Z - 122245Z POTENTIAL FOR VERY LOCALIZED HEAVY RAINFALL... AND ISOLATED LARGE HAIL IN SLOW MOVING STORMS CONTINUES THROUGH LATE AFTERNOON. LARGE-SCALE FORCING ASSOCIATED WITH MID-LEVEL CIRCULATION NOW SLOWLY TURNING EASTWARD ACROSS WESTERN TENNESSEE CONTINUES TO SUPPORT INCREASING STORM COVERAGE. HOWEVER...LACK OF PERSISTENT DEEP LOW-LEVEL CONVERGENCE ON SOUTHWESTERN PERIPHERY OF MID ATLANTIC SURFACE RIDGE APPEARS TO BE LIMITING FACTOR WITH REGARD TO CONSOLIDATION INTO MORE SUBSTANTIAL MESOSCALE CONVECTIVE SYSTEM. THIS...IN CONJUCTION WITH WEAK LOW/MID-LEVEL FLOW FIELDS AND SHEAR PROFILES...CONTINUES TO LIMIT OVERALL SEVERE THREAT...BUT ISOLATED LARGE HAIL WILL CONTINUE POSSIBLE AT LEAST ANOTHER COUPLE OF HOURS IN STRONGEST CELLS. OBJECTIVE ANALYSIS CURRENTLY INDICATES MEAN MIXED LAYER CAPE IN EXCESS OF 2000 J/KG. AS THE AFTERNOON WEARS ON BEYOND PEAK HEATING...AND MID/HIGH LEVEL CONVECTIVE CLOUD COVER BECOMES MORE WIDESPREAD...BOUNDARY LAYER WILL BEGIN TO STABILIZE... AND LARGE HAIL THREAT MAY DIMINISH BY AROUND 13/00Z. ..KERR.. 09/12/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OHX...BMX...HUN...PAH...MEG...JAN... 35748927 36478872 36558770 36098675 35408705 34828766 34078817 33498884 33419011 33819081 34708969
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 12, 10:41 AM CDT | Mesoscale Discussion | SPC | Alcorn, Benton, Lafayette, Marshall, Pontotoc, Prentiss and 3 more | 3 hr |
Nearby
Mesoscale Discussions in Tennessee, 2004Mesoscale Discussions in Mississippi, 2004Mesoscale Discussions in Alabama, 2004Every mesoscale discussion in 2004
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.