Alert archive / Florida / Mesoscale Discussions in 2021

Mesoscale Discussion 96

February 15, 20214 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Feb 15, 2021, 6:32 PM EST for 4 counties in Florida. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: Feb 15, 2021, 6:32 PM EST (23:32 UTC)
Expired: Feb 15, 2021, 8:30 PM EST
In force: 118 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

Counties Brevard County, FL, Indian River County, FL, Osceola County, FL, Seminole County, FL

The radar

The Melbourne radar (KMLB), 40 km from the middle of the area, began a volume at 23:35 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, 11.5 hours before the alert went out and 44 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: 556 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 783 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 99 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

As transmitted.

744 
ACUS11 KWNS 152332
SWOMCD
SPC MCD 152332 
FLZ000-160130-

Mesoscale Discussion 0096
NWS Storm Prediction Center Norman OK
0532 PM CST Mon Feb 15 2021

Areas affected...Parts of the east central Florida Peninsula

Concerning...Severe potential...Watch unlikely 

Valid 152332Z - 160130Z

Probability of Watch Issuance...20 percent

SUMMARY...An isolated supercell or two is possible across east
central portions of the Florida Peninsula, near the Space Coast,
between now and 8-9 PM EST.

DISCUSSION...Beneath strong (around 50 kt at 500 mb), broadly
cyclonic mid-level flow, isolated to scattered thunderstorm activity
has initiated along a pre-frontal low-level confluence zone across
interior portions of the eastern Florida Peninsula.  This is
occurring where daytime heating contributed to peaked mixed-layer
CAPE on the order of 1500-2000 J/kg.  

Although boundary-layer cooling is now underway, strong deep-layer
shear may allow for further intensification of a few cells for
another couple of hours.  This could include the evolution of
supercell structures with the potential to produce severe hail and
locally strong wind, which should tend to advect north-northeastward
with an eastward propagation, toward the vicinity of the Space Coast
through early this evening.  Low-level hodographs appear generally
weak, but some enhancement due to backed, south-southeasterly flow
near the coast could contribute to some risk for a tornado.

..Kerr/Guyer.. 02/15/2021

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

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

LAT...LON   29038120 29158084 28508047 27918043 27348068 27568112
            28248129 28618124 29038120

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 15, 12:24 PM EST	Mesoscale Discussion	SPC	Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 12 more	66 min
Feb 15, 12:55 PM EST	Tornado Watch	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 8 more	5 hr
Feb 15, 2:38 PM EST	Mesoscale Discussion	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Liberty	97 min
Feb 15, 2:47 PM EST	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Citrus, Clay, Columbia and 17 more	118 min
Feb 15, 3:02 PM EST	Tornado Watch	SPC	Alachua, Baker, Bradford, Clay, Columbia, Dixie and 13 more	7 hr
Feb 15, 4:08 PM EST	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Calhoun, Clay, Columbia and 18 more	2 hr

Nearby

Mesoscale Discussions in Florida, 2021 Every 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.