Alert archive / Florida / Mesoscale Discussions in 2021

Mesoscale Discussion 58

February 6, 202118 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Feb 6, 2021, 3:49 PM EST for 18 counties in Florida. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Feb 6, 2021, 3:49 PM EST (20:49 UTC)
Expired: Feb 6, 2021, 5:15 PM EST
In force: 86 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 40%

Counties Alachua County, FL, Bradford County, FL, Citrus County, FL, Columbia County, FL, Dixie County, FL, Gilchrist County, FL, Hernando County, FL, Lafayette County, FL, Lake County, FL, Levy County, FL, Marion County, FL, Orange County, FL, Pasco County, FL, Putnam County, FL, Seminole County, FL, Sumter County, FL, Suwannee County, FL, Union County, FL

The radar

The Tampa radar (KTBW), 166 km from the middle of the area, began a volume at 20:49 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 5Feb 6, 4:20 PM EST

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 12:00Z, 8.8 hours before the alert went out and 166 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1073 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 99 m²/s²
0-3 km storm-relative helicity: 250 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

000 
ACUS11 KWNS 062049
SWOMCD
SPC MCD 062049 
FLZ000-062215-

Mesoscale Discussion 0058
NWS Storm Prediction Center Norman OK
0249 PM CST Sat Feb 06 2021

Areas affected...Central/Northern Florida Peninsula

Concerning...Severe potential...Watch possible 

Valid 062049Z - 062215Z

Probability of Watch Issuance...40 percent

SUMMARY...Strong to severe storms moving onshore across the western
coast of Florida may pose a risk for damaging wind gusts, hail and a
tornado over the next few hours.

DISCUSSION...Several strong storms including a few supercells are
approaching the western coast of the central/ northern Florida
Peninsula. These storms are moving along a northward moving warm
front located near Ocala. Instability north of the front remains
elevated and weaker than to the south where surface heating and
dewpoints in the 60s have contributed to 500-1000 J/kg of MLCAPE.
Despite the limited buoyancy along and north of the front, severe
weather appears possible with the ongoing and additional convection
this evening. Deep-layer shear of greater than 50 kts will support
supercells capable of isolated large hail north of the front.
Additional surface based destabilization will be possible with
low-level warm advection as the front continue to move northward
this evening. The greater buoyancy and enhanced low-level shear
along the front will likely result in an increased severe risk as
storms become progressively more surface based. The primary hazards
will be damaging wind gusts, hail, and perhaps a tornado.

..Lyons.. 02/06/2021

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

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

LAT...LON   29678350 29878358 30148334 30288288 30268250 29838174
            29278140 28708108 28258117 28188170 28188230 28348277
            28588274 28778272 28888277 29108300 29188319 29368331
            29678350

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 6, 1:46 PM EST	Mesoscale Discussion	SPC	Brevard, Hardee, Hernando, Highlands, Hillsborough, Indian River and 6 more	2 hr
Feb 6, 4:21 PM EST	Tornado Watch	SPC	Alachua, Bradford, Citrus, Clay, Flagler, Gilchrist and 11 more	6 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.