Alert archive / Florida / Mesoscale Discussions in 2016

Mesoscale Discussion 977

June 18, 201621 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Jun 18, 2016, 1:43 PM EDT for 21 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 18, 2016, 1:43 PM EDT (17:43 UTC)
Expired: Jun 18, 2016, 3:45 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 5%

All 21 counties

Brevard County, FL, Citrus County, FL, DeSoto County, FL, Flagler County, FL, Glades County, FL, Hardee County, FL, Hernando County, FL, Highlands County, FL, Indian River County, FL, Lake County, FL, Marion County, FL, Martin County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Polk County, FL, Putnam County, FL, Saint Lucie County, FL, Seminole County, FL, Sumter County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 88 km from the middle of the area, began a volume at 17:45 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, 5.7 hours before the alert went out and 102 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: 1068 J/kg
Mixed-layer CIN: -60 J/kg
Mixed-layer LCL: 1030 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 113 m²/s²
0-3 km storm-relative helicity: 112 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

921 
ACUS11 KWNS 181744
SWOMCD
SPC MCD 181743 
FLZ000-181945-

MESOSCALE DISCUSSION 0977
NWS STORM PREDICTION CENTER NORMAN OK
1243 PM CDT SAT JUN 18 2016

AREAS AFFECTED...PORTIONS OF THE FL PENINSULA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 181743Z - 181945Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...ISOLATED DAMAGING WIND GUSTS ARE POSSIBLE THIS AFTERNOON.
COVERAGE AND INTENSITY IS EXPECTED TO BE TOO LIMITED FOR WATCH
ISSUANCE.

DISCUSSION...AT 1730Z...THUNDERSTORMS ARE INCREASING ACROSS THE NRN
FL PENINSULA IN THE VICINITY OF A WEAK COLD FRONT AND DEVELOPING SEA
BREEZE CIRCULATION. SOUTH OF THE FRONT...TEMPERATURES RISING INTO
THE LOW 90S AND DEWPOINTS IN THE 70S ARE SUPPORTING MODERATE
INSTABILITY. CONVECTION SHOULD REMAIN RELATIVELY DISORGANIZED DUE TO
WEAK VERTICAL SHEAR...THOUGH STEEP LOW-LEVEL LAPSE RATES WILL
SUPPORT A RISK OF ISOLATED WET MICROBURSTS. A SLIGHT ENHANCEMENT TO
NELY LOW-LEVEL FLOW RESULTING FROM A COMBINATION OF THE FRONT AND
EXPANDING SEA-BREEZE CIRCULATION MAY ALSO LOCALLY INCREASE THE
DAMAGING WIND THREAT LATER THIS AFTERNOON FROM ANY UPSCALE GROWTH
THAT RESULTS FROM STORM MERGERS. THE COVERAGE AND INTENSITY OF THE
SEVERE THREAT IS EXPECTED TO REMAIN TOO LOW FOR WATCH ISSUANCE.

..DEAN/GUYER.. 06/18/2016

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

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

LAT...LON   26698074 27008166 27268188 27848227 28638263 29158272
            29418256 29628231 29808188 29858139 28948076 28498061
            27918049 27188020 26698074

Nearby

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.