Alert archive / Florida / Mesoscale Discussions in 2017

Mesoscale Discussion 459

April 6, 201710 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2017, 6:10 AM EDT for 10 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 6, 2017, 6:10 AM EDT (10:10 UTC)
Expired: Apr 6, 2017, 8:15 AM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Hardee County, FL, Hillsborough County, FL, Lake County, FL, Manatee County, FL, Orange County, FL, Osceola County, FL, Pinellas County, FL, Polk County, FL, Seminole County, FL, Volusia County, FL

The radar

The Tampa radar (KTBW), 70 km from the middle of the area, began a volume at 10:13 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

Tampa Bay, FL (KTBW), launched 00:00Z, 10.2 hours before the alert went out and 70 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: 210 J/kg
Mixed-layer CIN: -138 J/kg
Mixed-layer LCL: 1465 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 81 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

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
Apr 5, 11:15 PM EDT	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Clay, Columbia, Duval and 8 more	2 hr
Apr 6, 12:15 AM EDT	Tornado Watch	SPC	Alachua, Baker, Bradford, Citrus, Clay, Columbia and 22 more	6 hr
Apr 6, 3:12 AM EDT	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Citrus, Clay, Columbia and 25 more	2 hr

Nearby

Mesoscale Discussions in Florida, 2017 Every mesoscale discussion in 2017

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.