Alert archive / Florida / Mesoscale Discussions in 2012

Mesoscale Discussion 810

May 14, 201221 counties in Florida; 6 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at May 14, 2012, 5:33 PM EDT for 21 counties in Florida; 6 counties in Georgia. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
May 14, 2012, 5:33 PM EDT (21:33 UTC)
Expired
May 14, 2012, 6:30 PM EDT
In force
57 min
Issued by
the Storm Prediction Center
Chance of a watch
5%
All 27 counties

Brevard County, FL, Broward County, FL, Clay County, FL, Duval County, FL, Flagler County, FL, Glades County, FL, Hendry County, FL, Highlands County, FL, Indian River County, FL, Martin County, FL, Miami-Dade County, FL, Nassau County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Palm Beach County, FL, Putnam County, FL, Saint Johns County, FL, Saint Lucie County, FL, Seminole County, FL, Volusia County, FL, Bryan County, GA, Camden County, GA, Chatham County, GA, Glynn County, GA, Liberty County, GA, McIntosh County, GA

The radar

The Melbourne radar (KMLB), 124 km from the middle of the area, began a volume at 21:33 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

Cape Canaveral, FL (KXMR), launched 12:00Z, 9.6 hours before the alert went out and 95 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, Cape Canaveral, FL at 12:00Z on 2012-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 55 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, Cape Canaveral, FL at 12:00Z on 2012-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 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
55 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
965 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
34 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.

100 
ACUS11 KWNS 142134
SWOMCD
SPC MCD 142133
FLZ000-GAZ000-142230-

MESOSCALE DISCUSSION 0810
NWS STORM PREDICTION CENTER NORMAN OK
0433 PM CDT MON MAY 14 2012

AREAS AFFECTED...SERN GA...FL PENINSULA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 142133Z - 142230Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...A FEW STORMS MAY CONTAIN STRONG WIND GUSTS INTO EARLY
EVENING. ANY SVR THREAT WILL LIKELY REMAIN VERY MARGINAL AND
SPOTTY...AND THUS A WW IS NOT NEEDED.

DISCUSSION...FAIRLY RICH DEEP MOISTURE...WITH PW VALUES OF 1.5-1.75
INCHES PER GPS DATA...COVERS THE REGION IN ASSOCIATION WITHIN A
BROAD PLUME OF SUBTROPICAL MOISTURE OVER THE ERN FRINGES OF A
COMPOSITE ERN CONUS MID-LEVEL TROUGH. DIABATIC HEATING IN POCKETS OF
INSOLATION HAS SUPPORTED SUFFICIENTLY STEEP LOW-LEVEL LAPSE RATES
YIELDING MODERATE INSTABILITY ACROSS THE AREA. AND...WITH NUMEROUS
SFC BOUNDARIES IN PLACE...LOW-LEVEL ASCENT CONTINUES TO SUPPORT
ISOLATED TO SCATTERED CONVECTION ACROSS THE AREA...WITH THE ZONES OF
GREATEST CONCENTRATION ACROSS SOUTH FLORIDA AND ACROSS THE NERN FL
PENINSULA/SERN GA. VWP DATA SUGGEST WEAK LOW-LEVEL FLOW BENEATH
20-25 KT OF SWLY MID-LEVEL FLOW...SUPPORTING EFFECTIVE BULK SHEAR
MAGNITUDES OF AROUND 25 KT. AS SUCH...OCCASIONAL MULTICELL
STRUCTURES WILL REMAIN POSSIBLE INTO EARLY EVENING...WITH STRONG
WIND GUSTS THE PRIMARY CONCERN /AND PERHAPS A MARGINALLY SVR WIND
GUST/...AIDED BY WATER-LOADING PROCESSES. THIS CONVECTION WILL
CONTINUE UNTIL NOCTURNAL STABILIZATION AND CONVECTIVE OVERTURNING
SUBSTANTIALLY INCREASE CINH...WITH STORMS LIKELY DIMINISHING IN
COVERAGE AND INTENSITY AFTER 00Z.

..COHEN/WEISS.. 05/14/2012

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

ATTN...WFO...CHS...MFL...MLB...TBW...JAX...

LAT...LON   32008103 31358117 30378133 28288053 26818002 25638016
            25368069 25898117 27508150 30268192 31728176 32098140
            32008103

Nearby

Mesoscale Discussions in Florida, 2012Mesoscale Discussions in Georgia, 2012Every mesoscale discussion in 2012

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.