- Day Three
acus03 kwns 180812
Storm Prediction Center ac 180811
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0211 am CST Tue Dec 18 2018
Valid 201200z - 211200z
..there is a slight risk of severe thunderstorms across much of
Severe thunderstorms are possible across the central and southern
Florida Peninsula Thursday. Some low severe threat could develop
over eastern North Carolina late in the day3 period.
Strong mid-level flow is forecast to dig southeast across Texas into
the southern Gulf basin during the day3 period. This process will
ensure significant deepening of a larger trough that will translate
east across MS valley into the southeastern US/eastern Gulf of
Mexico by Friday morning. As this trough evolves, low-mid level
trajectories will become increasingly favorable for higher Theta-E
air mass to advance north across the Caribbean into the southern Florida
Peninsula where near 70f surface dew points are likely to return.
This air-mass recovery is expected to aid significant convection
across the eastern Gulf basin early in the period along a pronounced
surface front where strong large-scale forcing for ascent will be
maximized. Very strong shear will develop across Florida ahead of the
short wave which will encourage organized convection. Frontal
convection will likely be linear in nature, but embedded supercells
are expected. There is some concern that isolated pre-frontal
supercells may also develop within an increasing warm advection
regime over the peninsula. If moisture/instability returns to Florida as
currently forecast, all severe hazards may be noted with this
activity given the strength and geometry of this evolving trough.
Later in the period, moisture may advance inland across eastern NC.
If sufficient instability can spread into this region supercells may
develop as low level jet strengthens across this region.