Alert archive / Florida / Tornado Watches in 2021
Tornado Watch 337
The Storm Prediction Center issued this tornado watch at Jul 6, 2021, 1:47 PM EDT for 21 counties in Florida. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 6, 2021, 1:47 PM EDT (17:47 UTC)
- Expired
- Jul 6, 2021, 11:00 PM EDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Strongest gust expected
- 60 kt
All 21 counties
Broward County, FL, Charlotte County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Highlands County, FL, Hillsborough County, FL, Lee County, FL, Manatee County, FL, Martin County, FL, Miami-Dade County, FL, Monroe County, FL, Okeechobee County, FL, Osceola County, FL, Palm Beach County, FL, Pinellas County, FL, Polk County, FL, Saint Lucie County, FL, Sarasota County, FL
The radar
The Tampa radar (KTBW), 129 km from the middle of the area, began a volume at 17:50 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 50%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 5%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 20%
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Tampa Bay, FL (KTBW), launched 12:00Z, 5.8 hours before the alert went out and 129 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.
- 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
The text
As transmitted.
490 WWUS20 KWNS 061743 SEL7 SPC WW 061743 FLZ000-CWZ000-070300- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 337 NWS Storm Prediction Center Norman OK 145 PM EDT Tue Jul 6 2021 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern and Central Florida Coastal Waters * Effective this Tuesday afternoon and evening from 145 PM until 1100 PM EDT. * Primary threats include... A few tornadoes possible SUMMARY...Strong low-level winds on the periphery of Elsa will support the possibility of tornadoes through the afternoon and evening, particularly across the western half of the Peninsula where low-level shear/SRH will be maximized. The tornado watch area is approximately along and 85 statute miles east and west of a line from 30 miles east northeast of Saint Petersburg FL to 70 miles southwest of Miami FL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 335...WW 336... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 15020. ...Guyer
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 10:34 AM EDT | Mesoscale Discussion | SPC | Charlotte, Collier, DeSoto, Glades, Hardee, Hendry and 12 more | 2 hr |
| Jul 6, 4:55 PM EDT | Mesoscale Discussion | SPC | Charlotte, Collier, DeSoto, Glades, Hardee, Hendry and 9 more | 95 min |
| Jul 6, 7:17 PM EDT | Mesoscale Discussion | SPC | Charlotte, Collier, Lee | 3 hr |
Nearby
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.