Alert archive / Florida / Mesoscale Discussions in 2016

Mesoscale Discussion 307

March 31, 20164 counties in Alabama; 6 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2016, 1:32 PM CDT for 4 counties in Alabama; 6 counties in Florida. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Mar 31, 2016, 1:32 PM CDT (18:32 UTC)
Expired: Mar 31, 2016, 2:30 PM CDT
In force: 58 min
Issued by: the Storm Prediction Center

Counties Baldwin County, AL, Covington County, AL, Escambia County, AL, Geneva County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL

The radar

The Eglin Afb radar (KEVX), 80 km from the middle of the area, began a volume at 18:34 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 236 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: 53 J/kg
Mixed-layer CIN: -640 J/kg
Mixed-layer LCL: 1024 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 203 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

051 
ACUS11 KWNS 311832
SWOMCD
SPC MCD 311832 
FLZ000-ALZ000-311930-

MESOSCALE DISCUSSION 0307
NWS STORM PREDICTION CENTER NORMAN OK
0132 PM CDT THU MAR 31 2016

AREAS AFFECTED...PORTIONS OF SRN/SERN AL AND THE WRN FL PANHANDLE

CONCERNING...TORNADO WATCH 67...

VALID 311832Z - 311930Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 67 CONTINUES.

SUMMARY...THE SEVERE THREAT ACROSS ERN PORTIONS OF WW 67 AND
LOCATIONS FURTHER E WILL PROBABLY REMAIN TOO ISOLATED TO WARRANT THE
ISSUANCE OF A NEW WW.

DISCUSSION...A LONG-LIVED SUPERCELL WITH TRANSIENT LOW-LEVEL
ROTATION HAS PROGRESSED EWD OVER SRN AL FOR THE PAST SEVERAL
HOURS...PRODUCING SPORADIC HAIL/WIND REPORTS. THE AIRMASS TO THE E
OF THIS ONGOING CONVECTION ACROSS SERN AL AND THE FAR WRN FL
PANHANDLE IS SLIGHTLY LESS UNSTABLE COMPARED TO LOCATIONS FURTHER
W...WITH SFC DEWPOINTS GENERALLY IN THE MID 60S...AND THE LOW-LEVEL
WIND FIELD ALSO WEAKENS WITH EWD EXTENT PER KMOB/KEVX/KTLH VWPS. IN
ADDITION...LARGE-SCALE FORCING ASSOCIATED WITH A SHORTWAVE TROUGH
OVER THE TN VALLEY IS BECOMING INCREASINGLY DISPLACED FROM THE
ONGOING THUNDERSTORMS IN SRN AL. ALL OF THESE FACTORS SUGGEST THE
OVERALL SEVERE THREAT IN ERN PORTIONS OF WW 67 AND FURTHER E SHOULD
REMAIN ISOLATED...AND WW 67 WILL PROBABLY BE ALLOWED TO EXPIRE AT
19Z AS SCHEDULED.

..GLEASON.. 03/31/2016

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

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

LAT...LON   30958774 31378735 31438657 31348585 30958548 30298553
            30028572 30388663 30208750 30738783 30958774

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 31, 7:47 AM CDT	Mesoscale Discussion	SPC	Washington	58 min
Mar 31, 8:37 AM CDT	Mesoscale Discussion	SPC	Baldwin, Butler, Choctaw, Clarke, Conecuh, Covington and 6 more	53 min
Mar 31, 8:43 AM CDT	Tornado Watch	SPC	Baldwin, Clarke, Conecuh, Covington, Escambia, Mobile and 2 more	5 hr
Mar 31, 11:29 AM CDT	Mesoscale Discussion	SPC	Baldwin, Butler, Coffee, Conecuh, Covington, Crenshaw and 5 more	2 hr
Mar 31, 4:47 PM CDT	Mesoscale Discussion	SPC	Bibb, Blount, Chilton, Choctaw, Clarke, Colbert and 19 more	58 min
Mar 31, 5:58 PM CDT	Tornado Watch	SPC	Autauga, Bibb, Blount, Chilton, Choctaw, Clarke and 33 more	7 hr
Mar 31, 6:52 PM CDT	Mesoscale Discussion	SPC	Bibb, Blount, Choctaw, Colbert, Cullman, Dallas and 22 more	53 min

Nearby

Mesoscale Discussions in Florida, 2016 Mesoscale Discussions in Alabama, 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.