Alert archive / Alabama / Mesoscale Discussions in 2003

Mesoscale Discussion 435

April 7, 200312 counties in Alabama; 5 counties in Florida; George County, Greene County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 7, 2003, 12:22 PM CDT for 12 counties in Alabama; 5 counties in Florida; George County, Greene County, Mississippi. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
Apr 7, 2003, 12:22 PM CDT (17:22 UTC)
Expired
Apr 7, 2003, 2:15 PM CDT
In force
113 min
Issued by
the Storm Prediction Center

Counties Baldwin County, AL, Butler County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Escambia County, AL, Geneva County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, George County, MS, Greene County, MS

The radar

The Mobile radar (KMOB), 98 km from the middle of the area, began a volume at 17:23 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

Slidell Radar S, LA (KSIL), launched 12:00Z, 5.4 hours before the alert went out and 243 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.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 12:00Z on 2003-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1394 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 12:00Z on 2003-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 163 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1394 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
592 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
212 m²/s²
Significant tornado parameter
1.2
Supercell composite
8.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

741 
ACUS11 KWNS 071722
SWOMCD
SPC MCD 071722 
ALZ000-FLZ000-MSZ000-071915-

MESOSCALE DISCUSSION 0435
NWS STORM PREDICTION CENTER NORMAN OK
1222 PM CDT MON APR 07 2003

AREAS AFFECTED...PORTIONS SE TX...SRN LA...SRN MS

CONCERNING...SEVERE THUNDERSTORM WATCH 112...

VALID 071722Z - 071915Z

SCATTERED SEVERE TSTMS WITH POTENTIALLY DESTRUCTIVE HAIL AND
OCCASIONAL SEVERE GUSTS SHOULD CONTINUE IN BROKEN BAND FROM
HARRIS/CHAMBERS/LIBERTY COUNTIES ENEWD ACROSS BTR REGION TO SRN
MS BETWEEN GPT-LUL.  ACTIVITY IS IN ZONE OF MAXIMIZED LOW LEVEL
CONVERGENCE ASSOCIATED WITH PREFRONTAL TROUGH/CYCLONIC SHEAR
LINE.  BOTH BOWS AND HEAVY-PRECIP SUPERCELLS ARE POSSIBLE...WITH
45-60 KT 0-6 KM AGL SHEARS OVER REGION.  MLCAPE 1500-2500 J/KG
EXPECTED AS INFLOW-SECTOR AIR MASS CONTINUES TO DIABATICALLY
WARM.



HAIL UP TO 2.75 INCH REPORTED IN VERMILION PARISH ABOUT 1615Z AND
UP TO 1.75 INCH HAIL ESTIMATED OVER OVER IBERIA PARISH LA AND
SWRN HARRIS COUNTY TX DURING PAST 30 MINUTES.  GIVEN CONTINUED
FAVORABLE SHEAR PROFILES AND VERY STEEP MIDLEVEL LAPSE RATES
8.5-9.5 DEG C/KM -- ASSOCIATED WITH ELEVATED MIXED-LAYER AIR AND
COMBINATION OF LARGE SCALE FORCING JUST AHEAD OF SHORTWAVE TROUGH
-- THREAT FOR SIGNIFICANT SEVERE HAIL WILL CONTINUE IN THIS WW.

..EDWARDS.. 04/07/2003

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...TAE...BMX...MOB...LIX...

31718849 32028640 31388563 30648567 30208850 30938882

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 8:13 PM CDTMesoscale DiscussionSPCBibb, Chilton, Choctaw, Dallas, Fayette, Greene and 8 more2 hr
Apr 6, 9:48 PM CDTMesoscale DiscussionSPCAutauga, Chilton, Choctaw, Clarke, Dallas, Hale and 6 more87 min
Apr 6, 10:15 PM CDTTornado WatchSPCAutauga, Butler, Choctaw, Clarke, Conecuh, Covington and 10 more5 hr
Apr 6, 11:39 PM CDTMesoscale DiscussionSPCAutauga, Butler, Choctaw, Clarke, Conecuh, Covington and 11 more2 hr
Apr 7, 1:51 AM CDTMesoscale DiscussionSPCBullock, Butler, Lowndes, Macon, Montgomery54 min
Apr 7, 2:55 AM CDTTornado WatchSPCAutauga, Barbour, Bullock, Chilton, Choctaw, Dallas and 13 more4 hr
Apr 7, 4:49 AM CDTMesoscale DiscussionSPCAutauga, Chambers, Chilton, Coosa, Dallas, Elmore and 11 more3 hr
Apr 7, 9:11 AM CDTMesoscale DiscussionSPCBarbour, Coffee, Conecuh, Covington, Crenshaw, Dale and 6 more3 hr
Apr 7, 9:40 AM CDTTornado WatchSPCBarbour, Bullock, Macon, Pike, Russell5 hr
Apr 7, 11:25 AM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more3 hr
Apr 7, 12:07 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more113 min
Apr 7, 3:40 PM CDTSevere Thunderstorm WatchSPCBaldwin, Covington, Escambia, Mobile5 hr
Apr 7, 5:58 PM CDTMesoscale DiscussionSPCBaldwin, Escambia, Mobile2 hr
Apr 7, 10:05 AM CDTSevere Thunderstorm WatchSPCAmite, Forrest, George, Greene, Hancock, Harrison and 11 more6 hr
Apr 7, 11:02 AM CDTMesoscale DiscussionSPCForrest, Lamar, Pearl River, Perry, Stone3 hr
Apr 7, 2:13 PM CDTMesoscale DiscussionSPCHancock, Harrison, Pearl River, Perry, Stone3 hr
Apr 7, 2:36 PM CDTMesoscale DiscussionSPCHancock, Harrison, Pearl River, Perry, Stone114 min

Nearby

Mesoscale Discussions in Alabama, 2003Mesoscale Discussions in Florida, 2003Mesoscale Discussions in Mississippi, 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.