Alert archive / Florida / Mesoscale Discussions in 2020

Mesoscale Discussion 1792

November 11, 20209 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Nov 11, 2020, 4:01 PM EST for 9 counties in Florida. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: Nov 11, 2020, 4:01 PM EST (21:01 UTC)
Expired: Nov 11, 2020, 5:00 PM EST
In force: 59 min
Issued by: the Storm Prediction Center
Concerning: Tornado watch 507

Counties Charlotte County, FL, Collier County, FL, DeSoto County, FL, Hardee County, FL, Hillsborough County, FL, Lee County, FL, Manatee County, FL, Pinellas County, FL, Sarasota County, FL

The radar

The Tampa radar (KTBW), 104 km from the middle of the area, began a volume at 21:00 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 12:00Z, 9.0 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-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: 87 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 985 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 124 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 11, 4:36 AM EST	Mesoscale Discussion	SPC	Charlotte, Collier, Lee, Monroe	2 hr
Nov 11, 8:04 AM EST	Tornado Watch	SPC	Charlotte, Collier, DeSoto, Hardee, Hillsborough, Lee and 3 more	9 hr
Nov 11, 11:56 AM EST	Mesoscale Discussion	SPC	Charlotte, Collier, DeSoto, Hardee, Hillsborough, Lee and 2 more	2 hr
Nov 11, 2:14 PM EST	Mesoscale Discussion	SPC	Broward, Glades, Monroe, Palm Beach	61 min

Nearby

Mesoscale Discussions in Florida, 2020 Every mesoscale discussion in 2020

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.