Alert archive / Florida / Mesoscale Discussions in 2020

Mesoscale Discussion 1820

November 29, 20208 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Nov 29, 2020, 7:05 PM CST for 8 counties in Florida. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Nov 29, 2020, 7:05 PM CST (01:05 UTC)
Expired: Nov 29, 2020, 9:00 PM CST
In force: 115 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

Counties Bay County, FL, Calhoun County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Liberty County, FL, Walton County, FL, Washington County, FL

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 1.1 hours before the alert went out and 117 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: 7 J/kg
Mixed-layer CIN: -68 J/kg
Mixed-layer LCL: 628 m above ground
0-6 km bulk shear: 70 kt
0-1 km storm-relative helicity: 365 m²/s²
0-3 km storm-relative helicity: 478 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 30, 12:56 AM CST	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Columbia, Dixie, Gadsden and 11 more	3 hr

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.