Alert archive / Arkansas / Mesoscale Discussions in 2004
Mesoscale Discussion 2321
The Storm Prediction Center issued this mesoscale discussion at Oct 18, 2004, 7:44 AM CDT for 6 states. It was in force for 61 min.
The area
The outline as issued.
The facts
- Issued
- Oct 18, 2004, 7:44 AM CDT (12:44 UTC)
- Expired
- Oct 18, 2004, 8:45 AM CDT
- In force
- 61 min
- Issued by
- the Storm Prediction Center
All 101 counties
Arkansas County, AR, Bradley County, AR, Calhoun County, AR, Clark County, AR, Clay County, AR, Cleburne County, AR, Cleveland County, AR, Conway County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Faulkner County, AR, Fulton County, AR, Garland County, AR, Grant County, AR, Greene County, AR, Hempstead County, AR, Hot Spring County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Jefferson County, AR, Lawrence County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Montgomery County, AR, Nevada County, AR, Ouachita County, AR, Perry County, AR, Phillips County, AR, Pike County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Sharp County, AR, St. Francis County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR, Alexander County, IL, Massac County, IL, Pulaski County, IL, Ballard County, KY, Calloway County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Butler County, MO, Carter County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Pemiscot County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Benton County, MS, Bolivar County, MS, Coahoma County, MS, DeSoto County, MS, Lafayette County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tunica County, MS, Yalobusha County, MS, Carroll County, TN, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN
The radar
The Little Rock radar (KLZK), 97 km from the middle of the area, began a volume at 12:47 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
Little Rock, AR (KLZK), launched 12:00Z, 0.7 hours before the alert went out and 137 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
- 1504 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 520 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 390 m²/s²
- 0-3 km storm-relative helicity
- 482 m²/s²
- Significant tornado parameter
- 3.3
- Supercell composite
- 16.6
The text
As transmitted, in the capitals the NWS used until 2016.
371 ACUS11 KWNS 181244 SWOMCD SPC MCD 181244 KYZ000-TNZ000-ILZ000-MSZ000-MOZ000-ARZ000-181345- MESOSCALE DISCUSSION 2321 NWS STORM PREDICTION CENTER NORMAN OK 0744 AM CDT MON OCT 18 2004 AREAS AFFECTED...AR/SERN MO EWD INTO WRN KY TO NRN MS CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 181244Z - 181345Z ADDITIONAL SEVERE STORMS POSSIBLE ACROSS AR INTO SRN MO THIS MORNING. AREA TO BE MONITORED FOR POTENTIAL WW. UPWARD VERTICAL MOTION ASSOCIATED WITH HEIGHT FALLS OVER AR/SRN MO AS THE SRN PLAINS SHORT WAVE TROUGH MOVES EWD...AND LIFT WITHIN THE LEFT EXIT REGION OF A 60 KT WSWLY MID-LEVEL JET NOSING INTO AR ATTM WILL CONTINUE TO SUPPORT THUNDERSTORMS. ONGOING ACTIVITY IS ORIENTED WITHIN WAA REGIME ALONG A 50 KT SWLY LLJ WHICH EXTENDED FROM ERN OK TO THE MID MS VALLEY. DEEP LAYER SHEAR IS MORE THAN SUFFICIENT FOR SUPERCELLS...WITH LOW-LEVEL SHEAR SUPPORTIVE OF TORNADOES. HOWEVER...12Z LIT SOUNDING SHOWED A SMALL SURFACE INVERSION /LESS THAN 1 KM IN DEPTH/ WHICH IS LIKELY INHIBITING THE STORMS FROM REALIZING THE STRONGER LOW-LEVEL SHEAR/TORNADO POTENTIAL ATTM. WARM TEMPERATURES ALOFT ARE EXPECTED TO LIMIT THE HAIL POTENTIAL...THOUGH ISOLATED DAMAGING WINDS ARE POSSIBLE WITH THE STRONGEST ACTIVITY. AS SURFACE HEATING COMMENCES THIS MORNING IN THE WAKE OF THE ONGOING ACTIVITY...THE POTENTIAL FOR SURFACE STORMS AND SUBSEQUENT TORNADO THREAT WILL INCREASE. A FEW STORMS HAVE THUS FAR SHOWN LITTLE STORM ROTATION...BUT ACTIVITY WILL CONTINUE TO BE MONITORED FOR A POTENTIAL WW ISSUANCE THIS MORNING. ..PETERS.. 10/18/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PAH...MEG...JAN...LSX...LZK...SGF...SHV... 36739192 37338977 37228792 35298861 34058957 33439146 33409313 33829385 34499392 35669276
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 17, 11:30 PM CDT | Severe Thunderstorm Watch | SPC | Baxter, Clay, Fulton, Greene, Marion, Randolph and 1 more | 6 hr |
| Oct 18, 2:19 AM CDT | Mesoscale Discussion | SPC | Baxter, Benton, Boone, Carroll, Clark, Clay and 42 more | 56 min |
| Oct 18, 4:40 AM CDT | Mesoscale Discussion | SPC | Clay, Greene, Randolph, Sharp | 35 min |
| Oct 18, 9:45 AM CDT | Tornado Watch | SPC | Arkansas, Calhoun, Cleveland, Dallas, Desha, Drew and 12 more | 5 hr |
| Oct 18, 11:29 AM CDT | Mesoscale Discussion | SPC | Arkansas, Calhoun, Cleveland, Dallas, Desha, Drew and 12 more | 91 min |
| Oct 18, 2:18 PM CDT | Mesoscale Discussion | SPC | Arkansas, Calhoun, Cleveland, Dallas, Desha, Drew and 12 more | 57 min |
| Oct 18, 4:05 PM CDT | Tornado Watch | SPC | Baxter, Clay, Cleburne, Craighead, Crittenden, Cross and 15 more | 5 hr |
| Oct 18, 5:21 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 22 more | 114 min |
| Oct 18, 5:50 PM CDT | Tornado Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 20 more | 5 hr |
| Oct 17, 10:01 PM CDT | Mesoscale Discussion | SPC | Monroe, Randolph | 3 hr |
| Oct 18, 10:20 AM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Clay, Clinton, Edwards, Effingham and 27 more | 85 min |
| Oct 18, 12:04 PM CDT | Mesoscale Discussion | SPC | Alexander, Jackson, Monroe, Pulaski, Randolph, Union | 86 min |
| Oct 18, 12:40 PM CDT | Tornado Watch | SPC | Alexander, Clinton, Jackson, Monroe, Perry, Randolph and 2 more | 5 hr |
| Oct 18, 1:55 PM CDT | Mesoscale Discussion | SPC | Gallatin, Hardin, Johnson, Massac, Pope, Pulaski and 2 more | 95 min |
| Oct 18, 3:41 PM CDT | Mesoscale Discussion | SPC | Alexander, Clinton, Jackson, Monroe, Perry, Randolph and 3 more | 94 min |
| Oct 18, 5:05 PM CDT | Tornado Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 17 more | 5 hr |
| Oct 18, 6:05 PM CDT | Mesoscale Discussion | SPC | Bond, Clay, Clinton, Crawford, Edwards, Effingham and 23 more | 115 min |
| Oct 18, 3:20 PM CDT | Tornado Watch | SPC | Franklin, Giles, Lincoln | 5 hr |
| Oct 18, 6:02 PM CDT | Mesoscale Discussion | SPC | Franklin, Giles, Lawrence, Lincoln, Moore, Wayne | 88 min |
Nearby
Mesoscale Discussions in Arkansas, 2004Mesoscale Discussions in Tennessee, 2004Mesoscale Discussions in Mississippi, 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.