Alert archive / Florida / Mesoscale Discussions in 2018

Mesoscale Discussion 1131

July 22, 201830 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Jul 22, 2018, 10:32 AM EDT for 30 counties in Florida. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Jul 22, 2018, 10:32 AM EDT (14:32 UTC)
Expired: Jul 22, 2018, 11:30 AM EDT
In force: 58 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 30 counties

Alachua County, FL, Baker County, FL, Bradford County, FL, Citrus County, FL, Clay County, FL, Columbia County, FL, Dixie County, FL, Duval County, FL, Flagler County, FL, Gadsden County, FL, Gilchrist County, FL, Hamilton County, FL, Hernando County, FL, Jefferson County, FL, Lafayette County, FL, Lake County, FL, Leon County, FL, Levy County, FL, Madison County, FL, Marion County, FL, Orange County, FL, Putnam County, FL, Saint Johns County, FL, Seminole County, FL, Sumter County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Volusia County, FL, Wakulla County, FL

The radar

The Jacksonville radar (KJAX), 137 km from the middle of the area, began a volume at 14:31 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 303Jul 22, 11:15 AM EDT

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 2.5 hours before the alert went out and 139 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: 2402 J/kg
Mixed-layer CIN: -52 J/kg
Mixed-layer LCL: 848 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 133 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 6.1

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
Jul 21, 11:29 PM EDT	Mesoscale Discussion	SPC	Holmes	2 hr
Jul 22, 11:15 AM EDT	Severe Thunderstorm Watch	SPC	Alachua, Baker, Bay, Bradford, Brevard, Calhoun and 38 more	10 hr
Jul 22, 12:27 PM EDT	Mesoscale Discussion	SPC	Bay, Calhoun, Escambia, Holmes, Jackson, Okaloosa and 3 more	63 min
Jul 22, 12:57 PM EDT	Severe Thunderstorm Watch	SPC	Escambia, Okaloosa, Santa Rosa	7 hr
Jul 22, 1:58 PM EDT	Mesoscale Discussion	SPC	Bay, Calhoun, Escambia, Holmes, Jackson, Okaloosa and 3 more	62 min
Jul 22, 2:56 PM EDT	Mesoscale Discussion	SPC	Bay, Calhoun, Escambia, Gadsden, Gulf, Holmes and 7 more	2 hr
Jul 22, 4:05 PM EDT	Mesoscale Discussion	SPC	Dixie, Gadsden, Gilchrist, Jackson, Jefferson, Lafayette and 9 more	115 min
Jul 22, 7:39 PM EDT	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Citrus, Columbia, Dixie and 16 more	66 min

Nearby

Mesoscale Discussions in Florida, 2018 Every mesoscale discussion in 2018

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.