Alert archive / Florida / Mesoscale Discussions in 2016

Mesoscale Discussion 541

May 4, 201617 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at May 4, 2016, 4:29 AM EDT for 17 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 4, 2016, 4:29 AM EDT (08:29 UTC)
Expired
May 4, 2016, 6:30 AM EDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Brevard County, FL, Citrus County, FL, Flagler County, FL, Hardee County, FL, Hernando County, FL, Hillsborough County, FL, Lake County, FL, Manatee County, FL, Marion County, FL, Orange County, FL, Osceola County, FL, Pasco County, FL, Pinellas County, FL, Polk County, FL, Seminole County, FL, Sumter County, FL, Volusia County, FL

The radar

The Tampa radar (KTBW), 108 km from the middle of the area, began a volume at 08:29 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

Tampa Bay, FL (KTBW), launched 00:00Z, 8.5 hours before the alert went out and 108 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, Tampa Bay, FL at 00:00Z on 2016-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1469 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, Tampa Bay, FL at 00:00Z on 2016-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.1939587897Sfc1 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
1469 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
918 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

146 
ACUS11 KWNS 040830
SWOMCD
SPC MCD 040829 
FLZ000-041030-

MESOSCALE DISCUSSION 0541
NWS STORM PREDICTION CENTER NORMAN OK
0329 AM CDT WED MAY 04 2016

AREAS AFFECTED...CENTRAL FL

CONCERNING...01Z OUTLOOK UPGRADE 

VALID 040829Z - 041030Z

SUMMARY...A FEW STRONG TO SEVERE STORMS MAY SHIFT FARTHER INLAND
FROM THE NORTHEAST GULF. AREA IS UPGRADED TO MARGINAL RISK THROUGH
THE REST OF THE CURRENT OUTLOOK PERIOD ENDING AT 12Z. MAIN HAZARD
SHOULD BE HAIL.

DISCUSSION...A CORRIDOR OF STORMS HAVE FORMED WITHIN A MODEST WARM
CONVEYOR DOWNSTREAM OF A LEAD SHORTWAVE IMPULSE OVER THE EASTERN
GULF AND SPREAD INTO HERNANDO/CITRUS COUNTIES. THE LEAD CELLS HAVE
ALREADY SPLIT...INDICATIVE OF THE STRONG SPEED SHEAR AND
STRAIGHT-LINE HODOGRAPHS IN THE MID/UPPER-LEVELS. SETUP SHOULD FAVOR
ISOLATED SEVERE HAIL AS THE PRIMARY RISK. WHILE MODEST LOW-LEVEL
SHEAR PER TAMPA BAY VWP DATA SHOULD TEMPER THE LONGEVITY/STRENGTH OF
LOWER-LEVEL ROTATION...PRESENCE OF LOWER 70S SURFACE DEW POINTS
COULD FOSTER A THREAT FOR LOCALLY DAMAGING WINDS AND EVEN A BRIEF
TORNADO.

..GRAMS/GOSS.. 05/04/2016

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

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

LAT...LON   29018276 29438165 29538106 29028062 28448046 27918048
            27578116 27268238 27408282 28658287 29018276

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.