Alert archive / Alabama / Mesoscale Discussions in 2016

Mesoscale Discussion 129

February 23, 20169 counties in Alabama; Holmes County, Okaloosa County, Walton County, Florida

The Storm Prediction Center issued this mesoscale discussion at Feb 23, 2016, 4:29 PM CST for 9 counties in Alabama; Holmes County, Okaloosa County, Walton County, Florida. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: Feb 23, 2016, 4:29 PM CST (22:29 UTC)
Expired: Feb 23, 2016, 5:30 PM CST
In force: 61 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Barbour County, AL, Bullock County, AL, Butler County, AL, Coffee County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Geneva County, AL, Pike County, AL, Holmes County, FL, Okaloosa County, FL, Walton County, FL

The radar

The Ft Rucker radar (KEOX), 61 km from the middle of the area, began a volume at 22:30 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

Birmingham, AL (KBMX), launched 12:00Z, 10.5 hours before the alert went out and 200 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: 546 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 99 m²/s²
0-3 km storm-relative helicity: 147 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

653 
ACUS11 KWNS 232229
SWOMCD
SPC MCD 232229 
FLZ000-ALZ000-232330-

MESOSCALE DISCUSSION 0129
NWS STORM PREDICTION CENTER NORMAN OK
0429 PM CST TUE FEB 23 2016

AREAS AFFECTED...SERN AL / W-CNTRL FL PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 232229Z - 232330Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE NEED FOR A TORNADO WATCH IS UNCERTAIN PRIOR TO THE
ACTIVITY FROM THE WEST MOVING INTO THE AREA.

DISCUSSION...RADAR IMAGERY DURING THE PAST 1-2 HOURS HAS SHOWN
SHALLOW CONVECTION DEVELOPING WITHIN THE WARM SECTOR ACROSS THE FL
PANHANDLE NWD INTO SERN AL.  MOST OF THIS ACTIVITY IS VOID OF
LIGHTNING YET THE POTENTIAL WILL EXIST WITHIN THE NEXT FEW HOURS FOR
A FEW UPDRAFTS TO INTENSIFY AS LARGE-SCALE ASCENT INCREASES ACROSS
THE REGION.  COINCIDENT WITH INCREASING LARGE-SCALE UPWARD VERTICAL
MOTION...THE WIND PROFILE IS FORECAST TO INTENSIFY CONSIDERABLY
DURING THE NEXT 1-3 HOURS.  AS SUCH...LOW-LEVEL MESOCYCLONE
POTENTIAL MAY INCREASE...ESPECIALLY IF CONVECTION PERSISTS BEYOND
THE LOSS OF DIURNAL HEATING.  GIVEN THE UNCERTAINTIES OF WHETHER THE
ACTIVITY OVER SERN AL/FL PANHANDLE INTENSIFIES FURTHER AND POSES A
SEVERE THREAT...A TORNADO WATCH ISSUANCE MAY BE REQUIRED EARLIER
THAN ANTICIPATED BASED ON EXTRAPOLATION FROM THE STORMS MOVING INTO
THE REGION FROM THE WEST.

..SMITH/HART.. 02/23/2016

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

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

LAT...LON   31988681 32318588 32068524 31288527 30268598 30488675
            31988681

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 23, 1:15 PM CST	Mesoscale Discussion	SPC	Baldwin, Butler, Choctaw, Clarke, Conecuh, Escambia and 5 more	2 hr
Feb 23, 2:13 PM CST	Tornado Watch PDS	SPC	Baldwin, Butler, Choctaw, Clarke, Conecuh, Covington and 6 more	8 hr
Feb 23, 5:18 PM CST	Mesoscale Discussion	SPC	Choctaw, Clarke, Monroe, Washington, Wilcox	117 min
Feb 23, 5:35 PM CST	Mesoscale Discussion	SPC	Autauga, Bibb, Chilton, Clay, Coosa, Dallas and 9 more	115 min
Feb 23, 5:53 PM CST	Tornado Watch	SPC	Autauga, Barbour, Bibb, Bullock, Chambers, Chilton and 21 more	6 hr

Nearby

Mesoscale Discussions in Alabama, 2016 Mesoscale Discussions in Florida, 2016 Every mesoscale discussion in 2016

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.