Alert archive / Florida / Mesoscale Discussions in 2021
Mesoscale Discussion 50
The Storm Prediction Center issued this mesoscale discussion at Jan 31, 2021, 10:12 PM EST for 7 counties in Florida. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 31, 2021, 10:12 PM EST (03:12 UTC)
- Expired
- Feb 1, 2021, 12:15 AM EST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Baker County, FL, Bradford County, FL, Clay County, FL, Columbia County, FL, Duval County, FL, Nassau County, FL, Union County, FL
The radar
The Jacksonville radar (KJAX), 67 km from the middle of the area, began a volume at 03:14 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
Jacksonville, FL (KJAX), launched 00:00Z, 3.2 hours before the alert went out and 69 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
- 101 J/kg
- Mixed-layer CIN
- -57 J/kg
- Mixed-layer LCL
- 988 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 284 m²/s²
- 0-3 km storm-relative helicity
- 391 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.8
The text
As transmitted.
290 ACUS11 KWNS 010312 SWOMCD SPC MCD 010312 FLZ000-GAZ000-010515- Mesoscale Discussion 0050 NWS Storm Prediction Center Norman OK 0912 PM CST Sun Jan 31 2021 Areas affected...north FL Concerning...Severe potential...Watch unlikely Valid 010312Z - 010515Z Probability of Watch Issuance...20 percent SUMMARY...An isolated risk for locally damaging winds may develop with a line segment as it moves across north FL through 1230am EST. DISCUSSION...Radar mosaic imagery as of 10pm EST shows a line segment moving east from the eastern FL Panhandle into the northern part of the FL Peninsula. Surface analysis indicates temperatures will likely hold steady in the upper 60s F with dewpoints in the lower 60s F ahead of the line segment. Recent radar trends have shown a maintenance of higher echo tops as the band of storms gradually organizes. The 00z Tallahassee and Jacksonville raobs showed a deep moist layer from the surface to 700 mb and a weak inversion was noted above the moist layer around 700 mb per the Jacksonville raob. Lapse rates within the lowest 3 km will remain modest with 500 J/kg MLCAPE objectively analyzed over north FL. It is possible a slow but slight intensification of the line segment will occur over the next 1-2 hours as an upper vorticity maxima over the central Gulf Coast approaches the region. It is unclear whether a threat for damaging gusts will develop but the environment will conditionally support a risk dependent on storm-scale processes. The overall severe risk appears too isolated/marginal to warrant a severe thunderstorm watch. ..Smith/Guyer.. 02/01/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JAX...TAE... LAT...LON 30358289 30718167 30008132 29658184 29798308 30358289
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.