Mesoscale Discussion 591

Issued

May 11, 2021, 1:12 PM EDT (17:12 UTC)

Expired

May 11, 2021, 3:15 PM EDT

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

5%

The Moody AFB radar (KVAX), 24 km from the middle of the area, began a volume at 17:12 UTC, the scan nearest the moment this went out.

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981 
ACUS11 KWNS 111712
SWOMCD
SPC MCD 111712 
GAZ000-FLZ000-111915-

Mesoscale Discussion 0591
NWS Storm Prediction Center Norman OK
1212 PM CDT Tue May 11 2021

Areas affected...North Florida and south-central Georgia

Concerning...Severe potential...Watch unlikely 

Valid 111712Z - 111915Z

Probability of Watch Issuance...5 percent

SUMMARY...Isolated to scattered thunderstorms are expected to
develop by the mid to late afternoon hours. One or two severe storms
are possible, but the threat will likely remain too limited to
warrant a watch issuance.

DISCUSSION...Regional radar trends over the past hour have shown
scattered convective showers developing over northern FL and
southern GA in the vicinity of a diffuse confluence axis. GOES IR
imagery shows fairly warm cloud tops, indicating that deeper
convection has not yet been achieved. However, surface temperatures
are warming into the low 80s and will likely reach surface-based
parcel convective temperatures by mid afternoon as warming continues
into the mid/upper 80s. Modified morning soundings from north FL
suggest MLCAPE is increasing upwards of 500 J/kg, and recent RAP
analyses show a similar trend that will likely continue through the
remainder of the day. Lift within the weak confluence axis may allow
for isolated to scattered thunderstorms by mid to late afternoon.
While this region is on the periphery of stronger upper-level flow
to the north, 30-40 knots of effective bulk shear should support
some storm organization and the potential for an isolated wind/hail
threat. Mean deep-layer flow along the confluence axis will likely
favor clusters of storms that may favor a wind threat over severe
hail, but the overall threat is expected to be fairly isolated and a
watch is not expected.

..Moore/Thompson.. 05/11/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...CHS...JAX...TAE...

LAT...LON   31068455 31458395 31588310 31648240 31638146 31418104
            30628110 29998136 29598245 29598351 29758442 29948492
            30518491 31068455

Mesoscale Discussions in Georgia, 2021Mesoscale Discussions in Florida, 2021Every mesoscale discussion in 2021

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.