Severe Storm Outlook Narrative (AC)
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
ACUS11 KWNS 181756
SWOMCD
SPC MCD 181755
FLZ000-182030-

Mesoscale Discussion 0270
NWS Storm Prediction Center Norman OK
1255 PM CDT Mon Mar 18 2024

Areas affected...Portions of the central and eastern Florida
Peninsula

Concerning...Severe potential...Watch unlikely

Valid 181755Z - 182030Z

Probability of Watch Issuance...20 percent

SUMMARY...Strong to severe storm potential will gradually increase
through the afternoon across portions of the central and eastern FL
Peninsula. Primary concerns are isolated large hail and locally
damaging gusts.

DISCUSSION...Latest day cloud phase satellite imagery indicates a
deepening boundary-layer cumulus field developing along/ahead of a
diffuse ENE/WSW-oriented cold front draped across central FL this
afternoon. Isolated convection is beginning to develop within this
cumulus field, as the associated frontal ascent intersects
steepening boundary-layer lapse rates and rich moisture (upper
60s/lower 70s surface dewpoints). During the next few hours, the
continued ascent and destabilization should support isolated to
widely scattered thunderstorms, which will generally spread
east-southeastward along the front, with additional isolated
development possible along differential heating boundaries into
southern FL.

The 15Z XMR sounding and more recent ACARS and VWP data are sampling
50-60 kt midlevel west-southwesterly flow, which is contributing to
a long/mostly straight hodograph (40-50 kt of effective shear).
This, combined with the continued boundary-layer destabilization
beneath relatively steep midlevel lapse rates, will support
organized multicells and transient/splitting supercells. As this
activity spreads eastward into the increasing surface-based
instability, the risk of isolated large hail up to 1.75 inches and
locally damaging gusts (potentially near 60 mph) will increase.
While less likely, a brief tornado cannot be entirely ruled out
along the east coast, where surface winds are beginning to back,
yielding modest low-level hodograph curvature/low-level streamwise
vorticity.

Given that large-scale forcing for ascent is weak and surface winds
are veered ahead of the front, the overall coverage of severe storms
should be limited, and storm intensification may be gradual.
Therefore, the severe risk appears too isolated for a watch at this
time.

..Weinman/Goss.. 03/18/2024

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

ATTN...WFO...MFL...MLB...TBW...JAX...

LAT...LON   26727995 26228000 26078019 26198045 26798095 27368174
            27438212 27748246 28148253 28528245 28938224 29328165
            29438126 29408095 28998062 28378030 27228003 26727995



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.