Alert archive / Florida / Mesoscale Discussions in 2017
Mesoscale Discussion 421
The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2017, 2:21 PM CDT for 11 counties in Florida. It was in force for 54 min.
The area
The outline as issued.
The facts
- Issued
- Apr 3, 2017, 2:21 PM CDT (19:21 UTC)
- Expired
- Apr 3, 2017, 3:15 PM CDT
- In force
- 54 min
- Issued by
- the Storm Prediction Center
Counties Bay County, FL, Calhoun County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Jefferson County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Taylor County, FL, Wakulla County, FL
The radar
The Tallahassee radar (KTLH), 52 km from the middle of the area, began a volume at 19:21 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
Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 7.4 hours before the alert went out and 54 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
- 1400 J/kg
- Mixed-layer CIN
- -14 J/kg
- Mixed-layer LCL
- 580 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 136 m²/s²
- 0-3 km storm-relative helicity
- 248 m²/s²
- Significant tornado parameter
- 1.5
- Supercell composite
- 9.3
The text
As transmitted.
849 ACUS11 KWNS 031922 SWOMCD SPC MCD 031921 GAZ000-FLZ000-032015- Mesoscale Discussion 0421 NWS Storm Prediction Center Norman OK 0221 PM CDT Mon Apr 03 2017 Areas affected...Northern FL Concerning...Tornado Watch 118... Valid 031921Z - 032015Z The severe weather threat for Tornado Watch 118 continues. SUMMARY...Severe threat continues across the eastern FL Panhandle into the northern portions of the FL Peninsula. DISCUSSION...Leading edge of long-lived MCS, that evolved over the central Gulf states, has progressed into central GA arcing into the eastern FL Panhandle. Weak-neutral height falls at this latitude appear to be partly responsible for a slowing southwest MCS flank with training convection now developing into the northeast Gulf Basin. While isolated tornadoes can not be ruled out with this activity, it appears damaging winds may be the primary severe threat along with an attendant heavy rain threat due to aforementioned training. ..Darrow.. 04/03/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JAX...TAE... LAT...LON 29558573 30728538 30738302 29558339 29558573
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 3, 6:43 AM CDT | Mesoscale Discussion | SPC | Bay, Calhoun, Escambia, Holmes, Jackson, Okaloosa and 3 more | 2 hr |
| Apr 3, 7:06 AM CDT | Tornado Watch | SPC | Bay, Calhoun, Escambia, Gulf, Holmes, Jackson and 4 more | 6 hr |
| Apr 3, 9:25 AM CDT | Mesoscale Discussion | SPC | Gadsden, Holmes, Jackson, Washington | 65 min |
| Apr 3, 12:32 PM CDT | Tornado Watch | SPC | Calhoun, Dixie, Franklin, Gadsden, Gulf, Jefferson and 6 more | 6 hr |
| Apr 3, 5:57 PM CDT | Mesoscale Discussion | SPC | Baker, Bradford, Clay, Columbia, Dixie, Duval and 17 more | 93 min |
Nearby
Mesoscale Discussions in Florida, 2017Every 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.