Alert archive / Georgia / Mesoscale Discussions in 2016

Mesoscale Discussion 659

May 20, 20168 counties in Florida; 14 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at May 20, 2016, 7:27 AM EDT for 8 counties in Florida; 14 counties in Georgia. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: May 20, 2016, 7:27 AM EDT (11:27 UTC)
Expired: May 20, 2016, 9:00 AM EDT
In force: 93 min
Issued by: the Storm Prediction Center

All 22 counties

Franklin County, FL, Gadsden County, FL, Jefferson County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Taylor County, FL, Wakulla County, FL, Baker County, GA, Brooks County, GA, Calhoun County, GA, Clay County, GA, Colquitt County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Grady County, GA, Miller County, GA, Mitchell County, GA, Seminole County, GA, Thomas County, GA, Tift County, GA

The radar

The Tallahassee radar (KTLH), 42 km from the middle of the area, began a volume at 11:29 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

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 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: 2260 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 939 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 68 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.5

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
May 19, 11:52 PM EDT	Severe Thunderstorm Watch	SPC	Escambia, Okaloosa, Santa Rosa	6 hr
May 20, 2:26 AM EDT	Mesoscale Discussion	SPC	Escambia, Holmes, Okaloosa, Santa Rosa, Walton	2 hr
May 20, 4:10 AM EDT	Severe Thunderstorm Watch	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 6 more	5 hr

Nearby

Mesoscale Discussions in Georgia, 2016 Mesoscale Discussions in Florida, 2016 Every mesoscale discussion in 2016

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.