Alert archive / Florida / Mesoscale Discussions in 2016

Mesoscale Discussion 274

March 26, 201615 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Mar 26, 2016, 2:52 PM EDT for 15 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 26, 2016, 2:52 PM EDT (18:52 UTC)
Expired
Mar 26, 2016, 5:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Hardee County, FL, Hernando County, FL, Highlands County, FL, Hillsborough County, FL, Lake County, FL, Marion County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Pasco County, FL, Polk County, FL, Putnam County, FL, Seminole County, FL, Sumter County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 92 km from the middle of the area, began a volume at 18:54 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, 6.9 hours before the alert went out and 104 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 2016-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 963 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 2016-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 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
963 J/kg
Mixed-layer CIN
-86 J/kg
Mixed-layer LCL
1137 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted.

498 
ACUS11 KWNS 261852
SWOMCD
SPC MCD 261852 
FLZ000-262115-

MESOSCALE DISCUSSION 0274
NWS STORM PREDICTION CENTER NORMAN OK
0152 PM CDT SAT MAR 26 2016

AREAS AFFECTED...PARTS OF CENTRAL FLORIDA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 261852Z - 262115Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AT LEAST ISOLATED STRONG TO SEVERE STORMS WITH MAINLY A
HAIL THREAT ARE EXPECTED TO FORM BY LATE AFTERNOON ACROSS PORTIONS
OF CNTRL AND N-CNTRL FL. GIVEN EXPECTED SPARSE SEVERE COVERAGE...A
WATCH MAY NOT BE WARRANTED.

DISCUSSION...SURFACE ANALYSIS SHOWS AN OLD BOUNDARY ACROSS N CNTRL
FL SEPARATING THE MODERATELY UNSTABLE AIR TO THE S FROM THE
PREVIOUSLY RAIN-COOLED AIR TO THE N...AND WITH ONLY WEAK CONVERGENCE
ALONG IT. MEANWHILE...A WEAK LOW PRESSURE TROUGH WAS ALSO NOTED FROM
NEAR TAMPA BAY EWD TO NEAR FT. PIERCE. THIS TROUGH WAS ALSO ROUGHLY
ALONG THE SRN EDGE OF CIRRUS/ANVIL BLOW OFF COURTESY OF STORMS TO
THE WEST.

VISIBLE SATELLITE IMAGERY ALSO SHOWS BOTH THE W AND E COAST SEA
BREEZE FRONTS SHIFTING INLAND...WITH FIELDS OF TOWERING CU INLAND.
INSPECTION OF AREA SOUNDINGS AND FORECAST SOUNDINGS REVEALS A
RELATIVE WARM LAYER NEAR 700 MB WHICH IS LIKELY HAMPERING VERTICAL
GROWTH TO THE LFC. HOWEVER...AS HEATING PERSISTS...AND SEA BREEZE
BOUNDARIES ENHANCE LIFT...ISOLATED STORMS ARE EXPECTED TO FORM. THE
BEST AREA APPEARS TO BE ALONG AND N OF THE AFOREMENTIONED SFC
TROUGH...EXTENDING NWD TO THE OLD SFC FRONT...AND IN BETWEEN THE TWO
SEA BREEZES. PLENTY OF INSTABILITY EXISTS GIVEN COOL TEMPERATURES IN
THE MIDLEVELS...AND SHEAR IS FAIRLY STRONG IN THE MID TO UPPER
LEVELS. THIS COULD FAVOR SPORADIC LARGE HAIL WITH THE STRONGEST
STORMS LATER THIS AFTERNOON.

..JEWELL/THOMPSON.. 03/26/2016

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

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

LAT...LON   27848071 27568062 27338091 27248152 27438210 27838241
            28258255 29208250 29578204 29658157 29528134 29378125
            27848071

Nearby

Mesoscale Discussions in Florida, 2016Every 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.