Alert archive / Florida / Mesoscale Discussions in 2021

Mesoscale Discussion 550

May 6, 20218 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at May 6, 2021, 12:05 PM EDT for 8 counties in Florida. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
May 6, 2021, 12:05 PM EDT (16:05 UTC)
Expired
May 6, 2021, 2:00 PM EDT
In force
115 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
40%

Counties Brevard County, FL, Indian River County, FL, Lake County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Seminole County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 47 km from the middle of the area, began a volume at 16:06 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, 4.1 hours before the alert went out and 65 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 2021-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 712 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 2021-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 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
712 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
989 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

073 
ACUS11 KWNS 061606
SWOMCD
SPC MCD 061605 
FLZ000-061800-

Mesoscale Discussion 0550
NWS Storm Prediction Center Norman OK
1105 AM CDT Thu May 06 2021

Areas affected...Central/Eastern FL Peninsula

Concerning...Severe potential...Watch possible 

Valid 061605Z - 061800Z

Probability of Watch Issuance...40 percent

SUMMARY...Coverage of thunderstorms will likely increase over the
next few hours. Some of these storms could be severe. An upgrade to
Slight Risk is forthcoming for the Space Coast.

DISCUSSION...Visible satellite imagery has shown increasingly deep
cumulus over the past half hour or so across much of the central FL
Peninsula, south of a cold front extending from CGC eastward to OMN.
Thunderstorms are expected to develop along and ahead of this front
as the air mass continues to destabilize, resulting in moderate
instability this afternoon. Additionally, moderate mid-level flow
extends across northern portions of central FL (roughly the northern
half of MLB's CWA) appears strong enough to support storm
organization and the potential for a somewhat organized convective
cluster. 

Given the expectation for increasing storm coverage and potential
for updraft organization, an upgrade to 15% wind/hail probabilities
is forthcoming in the 1630Z Convective Outlook for the Space Coast.
Convective trends will also be monitored closely for possible watch
issuance. Primary severe threat is damaging wind gusts, although
hail and potentially even a brief tornado are also possible.

..Mosier/Grams.. 05/06/2021

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   27708024 27378089 27488126 28158157 28688187 29368183
            29478097 27708024

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 6, 3:06 PM EDTMesoscale DiscussionSPCBroward, Martin, Miami-Dade, Palm Beach114 min

Nearby

Mesoscale Discussions in Florida, 2021Every mesoscale discussion in 2021

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.