Day 1 Severe Weather Outlook

Valid 052000Z – 061200Z


A few severe storms with damaging wind, a couple of tornadoes, and
isolated large hail are possible this afternoon and early evening
across northeast Florida and far southern Georgia.

…Northeast Florida through southern Georgia…

Primary change to previous outlook has been to trim the northern
portion of the SLGT and MRGL risk areas. This afternoon a
quasi-stationary front extends from a weak surface low over the
central FL Panhandle eastward to near the GA/FL border. Eastern
portion of this boundary across far northeast FL continues moving
southward, but should stall near Jacksonville. The warm sector has
destabilized with 1500 J/kg MLCAPE supported by modest (6.5 C/km )
mid level lapse rates, surface temperatures in the low 80s F and 70
F dewpoints. Low-level winds have veered to southwesterly in the
warm sector, limiting hodograph size somewhat. However, larger
hodographs exist in vicinity of the stalled front, and some increase
in the low-level jet is forecast this afternoon and early evening as
the low-amplitude shortwave trough advances through the southeast
states. Convection developing in warm sector has so far remained
shallow due to presence of a warm layer near 700 mb. However, a
gradual deepening of updrafts is expected this afternoon. Effective
bulk shear from 45-55 kt will support supercells and bowing segments
capable of hail and damaging wind. A couple of tornadoes remain
possible, especially with any storms that can move along/interact
with the stalled front before becoming elevated as they move deeper
into the cooler side.

..Dial.. 03/05/2020

.PREV DISCUSSION… /ISSUED 1019 AM CST Thu Mar 05 2020/

Latest surface analysis shows a low over the western tip of the FL
peninsula, with a warm front extending eastward from the low into
southern GA. A remnant outflow boundary is lifting northward through
northern FL and will merge with the warm front early this afternoon.
The air mass in the warm sector is moist, unstable, and strongly
sheared. Forecast soundings for later this afternoon show MLCAPE
over 1500 J/kg and impressive vertical shear profiles conducive to
supercell storms. The primary forecast concern is whether deep
convection can become established in this area. The upper trough is
lifting away from the region, low-level winds will slowly veer, and
convergence in the boundary-layer will be weak. This lowers
confidence that any intense storms will form.

Present indications are that greatest concern for a severe storm or
two will be over southeast GA and northeast FL, especially near the
coast. 12z CAM solutions suggest this is the most likely area of
intensification – before storms move offshore. Any storm that can
develop in the warm sector or along the warm front may become
supercellular, capable of damaging winds, hail, and tornadoes. The
severe risk should end by mid-evening.


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