Alert archive / Alabama / Mesoscale Discussions in 2004

Mesoscale Discussion 1439

June 28, 200410 counties in Alabama; 4 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2004, 5:09 AM CDT for 10 counties in Alabama; 4 counties in Mississippi. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Jun 28, 2004, 5:09 AM CDT (10:09 UTC)
Expired: Jun 28, 2004, 6:15 AM CDT
In force: 66 min
Issued by: the Storm Prediction Center

Counties Blount County, AL, Cullman County, AL, Fayette County, AL, Jefferson County, AL, Lamar County, AL, Marion County, AL, Pickens County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Clay County, MS, Lowndes County, MS, Monroe County, MS, Oktibbeha County, MS

The radar

The Columbus AFB radar (KGWX), 42 km from the middle of the area, began a volume at 10:11 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

Birmingham, AL (KBMX), launched 00:00Z, 10.2 hours before the alert went out and 122 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 995 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 806 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 41 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

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

555 
ACUS11 KWNS 281009
SWOMCD
SPC MCD 281009 
ALZ000-MSZ000-281115-

MESOSCALE DISCUSSION 1439
NWS STORM PREDICTION CENTER NORMAN OK
0509 AM CDT MON JUN 28 2004

AREAS AFFECTED...PORTIONS EAST CENTRAL/NERN MS AND WEST CENTRAL/NWRN
AL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 281009Z - 281115Z

ELEVATED BOWING LINE OF STORMS EXPECTED TO TRACK ACROSS PORTIONS OF
EAST CENTRAL/NERN MS INTO WEST CENTRAL/NWRN AL BETWEEN 10-13Z. 
DOWNSTREAM STABLE BOUNDARY LAYER ACROSS THE AREA OF CONCERN IS
EXPECTED TO LIMIT DOWNWARD TRANSFER OF HIGHER MOMENTUM AIR...THUS
LIMITING THE POTENTIAL FOR STRONG TO SEVERE WIND GUSTS.
WW NOT ANTICIPATED ATTM.

WV IMAGERY INDICATED A SHORT WAVE TROUGH OVER THE LOWER MS VALLEY AT
0915Z...WITH LARGE SCALE ASCENT ASSOCIATED WITH THIS FEATURE LIKELY
AIDING THUNDERSTORM DEVELOPMENT FROM SERN AR INTO NRN MS.  REGIONAL
RADARS SHOWED A BOWING LINE OF STORMS ALONG THE LEADING EDGE OF THIS
ACTIVITY...EXTENDING FROM PONTOTOC COUNTY TO ATTALA COUNTY MS AT
10Z.  20-25 KT SSWLY LLJ NOSING INTO THE WRN EDGE OF THIS CLUSTER OF
STORMS APPEARS TO BE FEEDING THIS ACTIVITY WITH A MOIST/MODERATELY
UNSTABLE AIR MASS LOCATED OVER ERN TX. 06Z RUC SUGGESTS STORMS WILL
PERSIST WITH AN EWD MOVEMENT OF 30-40 KT WITH THE MEAN WIND...AS THE
SHORT WAVE TROUGH MAINTAINS A LLJ INTO AND SOUTH OF THE COMPLEX. 
DAMAGING WIND THREAT WILL BE LOW...GIVEN THE STABLE BOUNDARY LAYER
DOWNSTREAM INTO AL ATTM...LIMITING THE DOWNWARD TRANSFER OF STRONGER
WINDS.

HOWEVER...IF THIS COMPLEX MAINTAINS ITSELF AFTER THE ONSET OF
SURFACE HEATING...THE RESULTANT AIR MASS DESTABILIZATION AND
FORECAST WIND FIELD MAY INCREASE THE SEVERE POTENTIAL LATER THIS
MORNING.

..PETERS.. 06/28/2004

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

ATTN...WFO...BMX...HUN...MEG...JAN...

34248879 34288637 33668641 33118684 33118817 33168942
33668882

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 28, 12:58 PM CDT	Mesoscale Discussion	SPC	Baldwin, Butler, Choctaw, Clarke, Conecuh, Covington and 6 more	2 hr
Jun 28, 5:03 PM CDT	Mesoscale Discussion	SPC	Russell	87 min

Nearby

Mesoscale Discussions in Alabama, 2004 Mesoscale Discussions in Mississippi, 2004 Every 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.