Alert archive / Alabama / Mesoscale Discussions in 2003

Mesoscale Discussion 83

February 15, 200325 counties in Alabama

The Storm Prediction Center issued this mesoscale discussion at Feb 15, 2003, 8:51 PM CST for 25 counties in Alabama. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Feb 15, 2003, 8:51 PM CST (02:51 UTC)
Expired
Feb 15, 2003, 10:15 PM CST
In force
84 min
Issued by
the Storm Prediction Center
All 25 counties

Autauga County, AL, Bibb County, AL, Blount County, AL, Butler County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Dallas County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lowndes County, AL, Marengo County, AL, Monroe County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Washington County, AL, Wilcox County, AL

The radar

The Birmingham radar (KBMX), 96 km from the middle of the area, began a volume at 02:54 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, 2.9 hours before the alert went out and 96 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, Birmingham, AL at 00:00Z on 2003-02-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 752 joules per kilogram.LCLEL10008507005003002001001 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, Birmingham, AL at 00:00Z on 2003-02-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 square meters per square second.193958Sfc1 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
752 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
1064 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

910 
ACUS11 KWNS 160252
SWOMCD
SPC MCD 160251 
ALZ000-160415-

MESOSCALE DISCUSSION 0083
NWS STORM PREDICTION CENTER NORMAN OK
0851 PM CST SAT FEB 15 2003

AREAS AFFECTED...WRN AL

CONCERNING...SEVERE THUNDERSTORM WATCH 8...

VALID 160251Z - 160415Z

LINE OF THUNDERSTORMS WITH EMBEDDED BOWS CONTINUES MOVING NEWD
ACROSS WW AREA.  SEVERE THREAT CONTINUES ACROSS WRN AND CENTRAL
AL.



LATEST KBMX VAD WIND PROFILE SHOWS LOW-LEVEL FLOW
INCREASING...WITH 55 KTS INDICATED FROM THE SOUTH AT 1 KM --
WHICH COMBINED WITH AMOUNT OF INSTABILITY INDICATED BY 00Z BMX
SOUNDING SUGGESTS THE THREAT FOR DAMAGING WINDS CONTINUES FOR
ANOTHER HOUR OR SO.



TWO SEPARATE BOW ECHOES ARE EVIDENT IN REFLECTIVITY LOOP MOVING
NEWD AT AROUND 50 KT...AND EXTRAPOLATION INDICATES THE CONVECTION
WILL BE MOVING OUT OF THE WATCH AT AROUND THE 16/04Z EXPIRATION
TIME.  ATTM...NEW WW IS NOT ANTICIPATED AS INSTABILITY APPEARS TO
BE WEAKER ACROSS ERN AL...AND OVERALL SEVERE THREAT EXPECTED TO
DIMINISH LATER THIS EVENING INTO THE SRN APPALACHIANS.	EXCEPTION
MAY BE NEARER THE GULF COAST WHERE GREATER INSTABILITY AND RICHER
BOUNDARY LAYER MOISTURE WILL REMAIN IN PLACE.

..GOSS.. 02/16/2003

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

31288750 31288835 32658826 34038818 34038731 34038643
32658654 31288665

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 15, 7:44 PM CSTMesoscale DiscussionSPCBaldwin, Escambia, Mobile3 hr
Feb 16, 2:55 AM CSTMesoscale DiscussionSPCGeneva, Houston2 hr

Nearby

Mesoscale Discussions in Alabama, 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.