Alert archive / Alabama / Mesoscale Discussions in 2011

Mesoscale Discussion 5

January 1, 201113 counties in Alabama; 9 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Jan 1, 2011, 12:32 PM CST for 13 counties in Alabama; 9 counties in Florida. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Jan 1, 2011, 12:32 PM CST (18:32 UTC)
Expired: Jan 1, 2011, 2:00 PM CST
In force: 88 min
Issued by: the Storm Prediction Center

All 22 counties

Baldwin County, AL, Bullock County, AL, Butler County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Houston County, AL, Mobile County, AL, Pike County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Holmes County, FL, Jackson County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL

The radar

The Eglin Afb radar (KEVX), 85 km from the middle of the area, began a volume at 18:35 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 6.5 hours before the alert went out and 239 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 904 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 169 m²/s²
0-3 km storm-relative helicity: 232 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

079 
ACUS11 KWNS 011833
SWOMCD
SPC MCD 011832
FLZ000-ALZ000-012000-

MESOSCALE DISCUSSION 0005
NWS STORM PREDICTION CENTER NORMAN OK
1232 PM CST SAT JAN 01 2011

AREAS AFFECTED...SRN AL THROUGH THE WRN FL PANHANDLE

CONCERNING...TORNADO WATCH 3...

VALID 011832Z - 012000Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 3 CONTINUES.

MODEST THREAT FOR AN ISOLATED TORNADO OR TWO REMAINS FROM SRN AL
INTO THE WRN FL PANHANDLE. MARGINAL THREAT FOR ISOLATED DAMAGING
WIND EXISTS A SMALL DISTANCE EAST OF WW 3 WITH LINE OF STORMS MOVING
THROUGH THE CNTRL FL PANHANDLE.

WIDESPREAD CONVECTION AND A FEW THUNDERSTORMS CONTINUE ALONG WARM
CONVEYOR BELT WITHIN PRE-FRONTAL WARM SECTOR FROM SRN AL THROUGH THE
WRN FL PANHANDLE. STORMS HAVE EVOLVED INTO A LINE ACROSS THE CNTRL
FL PANHANDLE WITH AN OUTFLOW BOUNDARY THAT TRAILS SWWD INTO THE
N-CNTRL GULF. EAST OF THE LINE SELY TRAJECTORIES FROM A DRIER AND
MORE STABLE BOUNDARY LAYER ARE LIMITING INSTABILITY AND OVERALL
SEVERE POTENTIAL. HOWEVER...A MARGINAL THREAT EXISTS FOR MAINLY AN
ISOLATED STRONG WIND GUST OR TWO AS THIS ACTIVITY MOVES THROUGH THE
CNTRL FL PANHANDLE. WEST OF THE LINE...WIDESPREAD SLIGHTLY ELEVATED
CONVECTION IS DEVELOPING ACROSS SRN AL AND THE WRN FL PANHANDLE
NORTH OF THE OUTFLOW BOUNDARY. THIS ACTIVITY WILL SERVE TO MAINTAIN
THE NEAR SURFACE STABLE LAYER WHICH IS THE PRIMARY LIMITING FACTOR.
DESPITE A LIMITED THERMODYNAMIC ENVIRONMENT...HODOGRAPHS AND STRONG
SHEAR PROFILES REMAIN FAVORABLE...AND CONVECTION APPEARS ROOTED
CLOSE ENOUGH TO SURFACE FOR AT LEAST A MODEST RISK OF AN ISOLATED
TORNADO OR TWO.

..DIAL.. 01/01/2011

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

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

LAT...LON   30618830 31848678 32168553 31268518 29798481 30258698
            30308807 30618830

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 31, 10:46 PM CST	Tornado Watch	SPC	Fayette, Greene, Lamar, Marion, Pickens, Sumter and 3 more	5 hr
Jan 1, 1:14 AM CST	Mesoscale Discussion	SPC	Cullman, DeKalb, Jackson, Lawrence, Limestone, Madison and 2 more	61 min
Jan 1, 3:10 AM CST	Tornado Watch	SPC	Autauga, Baldwin, Bibb, Blount, Butler, Calhoun and 34 more	7 hr
Jan 1, 6:06 AM CST	Mesoscale Discussion	SPC	Bibb, Calhoun, Cherokee, Chilton, Choctaw, Clarke and 13 more	114 min
Jan 1, 9:04 AM CST	Mesoscale Discussion	SPC	Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 9 more	56 min
Jan 1, 9:51 AM CST	Tornado Watch	SPC	Baldwin, Barbour, Bullock, Butler, Coffee, Conecuh and 10 more	4 hr

Nearby

Mesoscale Discussions in Alabama, 2011 Mesoscale Discussions in Florida, 2011 Every mesoscale discussion in 2011

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.