Alert archive / Mississippi / Mesoscale Discussions in 2003
Mesoscale Discussion 112
The Storm Prediction Center issued this mesoscale discussion at Feb 21, 2003, 5:20 PM CST for 4 states. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 21, 2003, 5:20 PM CST (23:20 UTC)
- Expired
- Feb 21, 2003, 9:15 PM CST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
All 66 counties
Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Cleveland County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Ouachita County, AR, Phillips County, AR, Prairie County, AR, St. Francis County, AR, Union County, AR, Claiborne Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Union Parish, LA, West Carroll Parish, LA, Benton County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Lafayette County, MS, Leflore County, MS, Marshall County, MS, Montgomery County, MS, Panola County, MS, Pontotoc County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Warren County, MS, Washington County, MS, Yalobusha County, MS, Yazoo County, MS, Fayette County, TN, Hardeman County, TN, Haywood County, TN, Shelby County, TN, Tipton County, TN
The radar
The Little Rock radar (KLZK), 173 km from the middle of the area, began a volume at 23:22 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, 11.3 hours before the alert went out and 179 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
- 455 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 168 m²/s²
- 0-3 km storm-relative helicity
- 183 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
450 ACUS11 KWNS 212321 SWOMCD SPC MCD 212320 LAZ000-ARZ000-TNZ000-MSZ000-220315- MESOSCALE DISCUSSION 0112 NWS STORM PREDICTION CENTER NORMAN OK 0520 PM CST FRI FEB 21 2003 AREAS AFFECTED...NWRN MS...SWRN TN...NERN LA...SERN AR CONCERNING...HEAVY RAINFALL VALID 212320Z - 220315Z SCATTERED-NUMEROUS TSTMS WILL SPREAD NEWD FROM W-CENTRAL AND N-CENTRAL LA...WITH ADDITIONAL CONVECTION DEVELOPING OVER THIS REGION THROUGH AT LEAST 4Z. EXPECT MERGING/TRAINING OF CELLS WITH PEAK RAIN RATES NEAR 3 INCHES/HOUR AND 1.5-2.5 INCH/HOUR RATES BEING COMMON. A FEW TSTMS MAY PRODUCE HAIL/WIND NEAR SEVERE LIMITS IN THIS TIME FRAME...BUT PRIND GREATER SEVERE POTENTIAL WILL REMAIN FARTHER S. SURFACE MESOANALYSIS SHOWS CYCLONE OVER EXTREME SERN TX...WARM FRONT EWD ACROSS S-CENTRAL LA. WARM FRONT INTERSECTS RESIDUAL OUTFLOW BOUNDARY INVOF RAPIDES PARISH...WITH INVERTED TROUGH NEWD ALONG ROUGHLY GLH-MKL LINE. STRONGEST PRESSURE FALLS REMAIN FROM JUST NE OF SURFACE CYCLONE INVOF INVERTED TROUGH -- AND N OF OUTFLOW BOUNDARY IN RELATIVELY COOL/STABLE BOUNDARY LAYER AIR. THIS...AS WELL AS VWP/PROFILER WINDS...INDICATE INTENSE LOW LEVEL WAA...ELEVATED ATOP COOL AIR OVER DISCUSSION AREA. THIS PROCESS WILL CONTINUE THROUGH THIS EVENING...DESTABILIZING AIR MASS WITH ELEVATED MUCAPE INCREASING TO 1500-2500 J/KG RANGE OVER SERN AR/NWRN MS AND 800-1500 J/KG AS FAR N AS WRN TN BASED ON RUC2 FORECAST SOUNDINGS. MOISTURE WILL BE QUITE ABUNDANT OVER REGION WITH PW 1.5-2 INCHES AND GRADUALLY INCREASING. AFTER DARK...50-65 KT LLJ WILL FURTHER ENHANCE ELEVATED ASCENT..WITH RUC 294K-297K ISENTROPIC PROGS INDICATING INCREASING LIFT. ..EDWARDS.. 02/21/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... 32089136 32209249 32729308 33819293 34869186 35659029 35588890 34428880 32339063
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 21, 1:43 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 6 more | 2 hr |
| Feb 21, 4:35 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Avoyelles, Concordia, East Baton Rouge, East Feliciana and 16 more | 115 min |
| Feb 21, 9:02 AM CST | Mesoscale Discussion | SPC | Beauregard, Calcasieu, Cameron, Sabine, Vernon | 58 min |
| Feb 21, 9:40 AM CST | Tornado Watch | SPC | Acadia, Allen, Beauregard, Calcasieu, Caldwell, Cameron and 11 more | 6 hr |
| Feb 21, 11:47 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 4 more | 118 min |
| Feb 21, 3:32 PM CST | Mesoscale Discussion | SPC | Allen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Vernon | 118 min |
| Feb 21, 3:40 PM CST | Tornado Watch | SPC | Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more | 6 hr |
| Feb 21, 5:50 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more | 115 min |
Nearby
Mesoscale Discussions in Mississippi, 2003Mesoscale Discussions in Arkansas, 2003Mesoscale Discussions in Louisiana, 2003Every mesoscale discussion in 2003
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.