Alert archive / Florida / Mesoscale Discussions in 2011

Mesoscale Discussion 2385

December 21, 2011Bay County, Gulf County, Florida

The Storm Prediction Center issued this mesoscale discussion at Dec 21, 2011, 2:16 AM CST for Bay County, Gulf County, Florida. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Dec 21, 2011, 2:16 AM CST (08:16 UTC)
Expired
Dec 21, 2011, 3:45 AM CST
In force
89 min
Issued by
the Storm Prediction Center

Counties Bay County, FL, Gulf County, FL

The radar

The Eglin Afb radar (KEVX), 66 km from the middle of the area, began a volume at 08:17 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 00:00Z, 8.3 hours before the alert went out and 179 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, Tallahassee Rgnl, FL at 00:00Z on 2011-12-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 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, Tallahassee Rgnl, FL at 00:00Z on 2011-12-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 square meters per square second.19395878Sfc1 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
2 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
606 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
194 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.

942 
ACUS11 KWNS 210817
SWOMCD
SPC MCD 210816
FLZ000-210945-

MESOSCALE DISCUSSION 2385
NWS STORM PREDICTION CENTER NORMAN OK
0216 AM CST WED DEC 21 2011

AREAS AFFECTED...COASTAL SECTIONS OF THE FL PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 210816Z - 210945Z

AN ISOLATED TORNADO...MOST PROBABLE WITH A WATERSPOUT MOVING ASHORE
FROM THE GULF OF MEXICO...WILL BE POSSIBLE ALONG THE IMMEDIATE COAST
INTO EARLY THIS MORNING AS TSTMS OVER THE NORTH CENTRAL GULF TRACK
TOWARD THE NNE.  LIMITED THREAT COVERAGE PRECLUDES THE NEED FOR A
WATCH AT THIS TIME.

REGIONAL RADAR IMAGERY/LIGHTNING DATA AND COOLING CLOUD TOP PER IR
SATELLITE IMAGERY SHOWED AN AREA OF TSTMS CONTINUING TO DEVELOP
OFFSHORE ACROSS THE NORTH CENTRAL GULF OF MEXICO FROM 140 SE BVE TO
55 SSE PNS...AND A STORM CURRENTLY APPROACHING THE COASTS OF SERN
WALTON AND BAY COUNTIES.  THIS ACTIVITY WAS LOCATED WITHIN A ZONE OF
LOW LEVEL CONVERGENCE EXTENDING NWD FROM THE WRN CARIBBEAN AND FL
STRAITS TO ALONG AND OFFSHORE THE WRN FL PANHANDLE...WITH THIS
CORRIDOR BEING THE CONDUIT FOR A NWD TRANSPORT OF GREATER MOISTURE
LADEN AIR.  THIS LATTER FACTOR IS SUPPORTING LOWER LCLS WITH THE
STORMS OVER THE NORTH CENTRAL GULF.  DESPITE WEAK INSTABILITY/LAPSE
RATES WHICH WILL TEND TO LIMIT THE NUMBER OF STRONGER LONG-LIVED
UPDRAFTS/STORMS...STRONG DEEP LAYER SHEAR WILL SUPPORT SOME STORM
ORGANIZATION.  OF CONCERN IS THE SELY SURFACE WINDS OVER THE FL
PANHANDLE ENHANCING LOW LEVEL DIRECTIONAL SHEAR TO SUSTAIN
WATERSPOUTS AS THEY APPROACH THE COAST AND POSE A THREAT FOR AN
ISOLATED TORNADO.  MOST STORMS AND SEVERE WEATHER THREAT SHOULD
DIMINISH AS THEY MOVE FARTHER INLAND ACROSS THE PANHANDLE WHERE
INHIBITION IS GREATER AND LIMITS PARCELS FROM BEING ROOTED AT THE
SURFACE.

..PETERS.. 12/21/2011

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

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

LAT...LON   29368528 29598576 29898653 30048708 30238720 30588687
            30548624 30418570 29898503 29368528

Nearby

Mesoscale Discussions in Florida, 2011Every 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.