Alert archive / Florida / Mesoscale Discussions in 2021
Mesoscale Discussion 60
The Storm Prediction Center issued this mesoscale discussion at Feb 6, 2021, 9:48 PM EST for 16 counties in Florida. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- Feb 6, 2021, 9:48 PM EST (02:48 UTC)
- Expired
- Feb 6, 2021, 11:15 PM EST
- In force
- 87 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 5
Counties Alachua County, FL, Citrus County, FL, Flagler County, FL, Hernando County, FL, Hillsborough County, FL, Lake County, FL, Levy County, FL, Marion County, FL, Orange County, FL, Pasco County, FL, Pinellas County, FL, Putnam County, FL, Saint Johns County, FL, Seminole County, FL, Sumter County, FL, Volusia County, FL
The radar
The Tampa radar (KTBW), 128 km from the middle of the area, began a volume at 02:47 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 00:00Z, 2.8 hours before the alert went out and 128 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
- 1198 J/kg
- Mixed-layer CIN
- -24 J/kg
- Mixed-layer LCL
- 813 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 249 m²/s²
- 0-3 km storm-relative helicity
- 286 m²/s²
- Significant tornado parameter
- 1.8
- Supercell composite
- 7.7
The text
As transmitted.
460 ACUS11 KWNS 070248 SWOMCD SPC MCD 070248 FLZ000-070415- Mesoscale Discussion 0060 NWS Storm Prediction Center Norman OK 0848 PM CST Sat Feb 06 2021 Areas affected...Northern/Central FL Peninsula Concerning...Tornado Watch 5... Valid 070248Z - 070415Z The severe weather threat for Tornado Watch 5 continues. SUMMARY...Severe threat will likely increase across portions of the northern/central FL Peninsula after 05-06z. New WW will be warranted to account for this threat. DISCUSSION...Higher theta-e air mass has struggled to advance north across the Peninsula this evening, partly due to extensive elevated convection north of the warm front and an eastern lobe of lower surface pressure off the northern FL Atlantic Coast in association with earlier convection. Strong/severe thunderstorms should be limited over land the next few hours near/just north of the boundary due to somewhat weaker low-level convergence. However, southwesterly LLJ should increase a bit toward 06z and this should encourage offshore convection over the northeastern Gulf of Mexico to spread inland. It appears upper 60s surface dew points could advance into southern Marion and northern Volusia counties prior to the upstream short-wave's influence. If so, near-surface based supercells are possible along with some potential for a few tornadoes. Will continue to monitor this situation and a tornado watch will likely be warranted across this region into the pre-dawn hours. ..Darrow.. 02/07/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MLB...TBW...JAX... LAT...LON 28498362 29608269 30078107 29098047 27388300 28498362
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 6, 7:41 PM EST | Mesoscale Discussion | SPC | Alachua, Bradford, Citrus, Clay, Dixie, Flagler and 11 more | 2 hr |
| Feb 6, 10:58 PM EST | Tornado Watch | SPC | Brevard, Citrus, Flagler, Hardee, Hernando, Hillsborough and 14 more | 8 hr |
| Feb 7, 2:13 AM EST | Mesoscale Discussion | SPC | Brevard, Citrus, Flagler, Hardee, Hernando, Hillsborough and 14 more | 2 hr |
| Feb 7, 6:28 AM EST | Mesoscale Discussion | SPC | Brevard, Hardee, Hillsborough, Lake, Manatee, Orange and 7 more | 2 hr |
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.