Alert archive / Florida / Mesoscale Discussions in 2007

Mesoscale Discussion 1998

September 21, 20077 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Sep 21, 2007, 10:45 AM CDT for 7 counties in Florida. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: Sep 21, 2007, 10:45 AM CDT (15:45 UTC)
Expired: Sep 21, 2007, 11:45 AM CDT
In force: 60 min
Issued by: the Storm Prediction Center

Counties Bay County, FL, Calhoun County, FL, Franklin County, FL, Gulf County, FL, Liberty County, FL, Wakulla County, FL, Washington County, FL

The radar

The Eglin Afb radar (KEVX), 59 km from the middle of the area, began a volume at 15:45 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, 3.8 hours before the alert went out and 123 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: 399 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 507 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 94 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

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
Sep 20, 9:56 PM CDT	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Citrus, Clay, Columbia and 13 more	94 min
Sep 20, 10:19 PM CDT	Tornado Watch	SPC	Alachua, Bradford, Columbia, Dixie, Gilchrist, Hamilton and 12 more	7 hr
Sep 21, 1:35 AM CDT	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Columbia, Dixie, Franklin and 13 more	115 min
Sep 21, 4:37 PM CDT	Mesoscale Discussion	SPC	Bay, Calhoun, Escambia, Gadsden, Gulf, Holmes and 9 more	53 min
Sep 21, 4:58 PM CDT	Tornado Watch	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 10 more	7 hr

Nearby

Mesoscale Discussions in Florida, 2007 Every mesoscale discussion in 2007

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.