Alert archive / Florida / Mesoscale Discussions in 2021

Mesoscale Discussion 1169

July 6, 2021Charlotte County, Collier County, Lee County, Florida

The Storm Prediction Center issued this mesoscale discussion at Jul 6, 2021, 7:17 PM EDT for Charlotte County, Collier County, Lee County, Florida. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jul 6, 2021, 7:17 PM EDT (23:17 UTC)
Expired
Jul 6, 2021, 10:15 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Concerning
Tornado watch 337

Counties Charlotte County, FL, Collier County, FL, Lee County, FL

The radar

The Tampa radar (KTBW), 140 km from the middle of the area, began a volume at 23:19 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.

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 12:00Z, 11.3 hours before the alert went out and 140 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-pSkew-T log-p diagram, Tampa Bay, FL at 12:00Z on 2021-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 815 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tampa Bay, FL at 12:00Z on 2021-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
815 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
773 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
25 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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.

IssuedProductOfficeCountiesLasted
Jul 6, 10:34 AM EDTMesoscale DiscussionSPCCharlotte, Collier, DeSoto, Glades, Hardee, Hendry and 12 more2 hr
Jul 6, 1:47 PM EDTTornado WatchSPCBroward, Charlotte, Collier, DeSoto, Glades, Hardee and 15 more9 hr
Jul 6, 4:55 PM EDTMesoscale DiscussionSPCCharlotte, Collier, DeSoto, Glades, Hardee, Hendry and 9 more95 min

Nearby

Mesoscale Discussions in Florida, 2021Every mesoscale discussion in 2021

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.