Alert archive / Florida / Mesoscale Discussions in 2013

Mesoscale Discussion 1489

July 23, 2013Houston County, Alabama; 12 counties in Florida; 9 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Jul 23, 2013, 6:37 PM CDT for Houston County, Alabama; 12 counties in Florida; 9 counties in Georgia. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Jul 23, 2013, 6:37 PM CDT (23:37 UTC)
Expired: Jul 23, 2013, 8:00 PM CDT
In force: 83 min
Issued by: the Storm Prediction Center

All 22 counties

Houston County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Gadsden County, FL, Holmes County, FL, Jackson County, FL, Leon County, FL, Liberty County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Calhoun County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Grady County, GA, Miller County, GA, Mitchell County, GA, Seminole County, GA

The radar

The Ft Rucker radar (KEOX), 61 km from the middle of the area, began a volume at 23:40 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 12:00Z, 11.6 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: 1595 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 535 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -30 m²/s²
0-3 km storm-relative helicity: -23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 23, 10:04 AM CDT	Mesoscale Discussion	SPC	Greene, Hale, Pickens, Sumter	86 min
Jul 23, 1:15 PM CDT	Severe Thunderstorm Watch	SPC	Autauga, Baldwin, Barbour, Bibb, Bullock, Butler and 40 more	7 hr
Jul 23, 2:31 PM CDT	Mesoscale Discussion	SPC	Autauga, Baldwin, Barbour, Bibb, Bullock, Butler and 35 more	89 min

Nearby

Mesoscale Discussions in Florida, 2013 Mesoscale Discussions in Georgia, 2013 Mesoscale Discussions in Alabama, 2013 Every mesoscale discussion in 2013

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.