228
FXUS64 KBMX 171204
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
704 AM CDT Fri May 17 2024

...New AVIATION...

.SHORT TERM...
(Today through Saturday)
Issued at 307 AM CDT FRI MAY 17 2024

This morning, an MCS is moving through the northern Gulf, with
heavy rainfall and thunderstorms along the coastline and light to
moderate rainfall extending northward into Central Alabama. Aloft,
westerly to southwesterly flow ahead of an approaching trough
remains active, with several impulses aiding in convection today
and tomorrow.

This first wave of rain will move eastward this morning, with the
stronger storms remaining to our south. This MCS has left a boundary
stretching eastward through southern MS. Additional thunderstorms
are already developing on that boundary and moving into southern
Alabama. As southerly low level flow increases later this morning,
this boundary will lift northward and be the focus for any strong
to severe storms this afternoon and tonight, across south Central
Alabama. CAPE values climb over 2000J/kg with 50kts of bulk
shear would be supportive of strong to severe storms. Assuming
the boundary lifts northward and storms become surface based, a
slight risk of severe storms exists near and south of the
Hwy80/I-85 corridor from noon til 11pm. Damaging winds, large
hail, and a couple tornadoes are possible.

In response to weak divergence and lift aloft, showers and storms
are also expected to develop this morning across north Central
Alabama. This activity is already occurring across north MS and
western TN. Any activity across the north will prevent the
southern boundary from lifting northward, and help suppress better
quality instability to the south. This would limit the severe
threat for Central Alabama. Also, rainfall totals have trended
downward, and do not anticipate needing a flood watch.

A lull in convection is expected overnight/early Saturday morning.
However, the parameter space with the shortwave still to our west
would be conducive for strong to severe storms, if activity can
redevelop in the wake of activity moving out of the area. The
trough over the southern Plains moves across the Lower
Mississippi River Valley Saturday, and expect expansion of
convection in response to lift from the trough, weak low level
convergence (mainly north), and continued elevated instability.
While coverage will be numerous areawide, the better chances of
severe storms will be across the southeast, where the 850mb jet is
enhanced, with development along the previous day`s convective
boundaries. Threats would include damaging winds, large hail, and
a couple tornadoes.

14

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 307 AM CDT FRI MAY 17 2024

Saturday night and Sunday.

Showers and storms will be ongoing Saturday night as the system
begins to exit the area. Rain chances will quickly decrease from
west to east during the evening. The upper level low will then move
in Saturday night and exit by Sunday afternoon. A few models tries
to wrap some additional rainfall along the backside of the low, so
low chances remain in the area through Sunday afternoon.

Monday through Thursday.

Deep-layer ridging is depicted in medium-range & ensembles
thereafter, which supports a period of dry, warm weather that
appears to extend into early next week. Highs in the 90s could be
possible by then. On Wednesday we will begin to see the next system
take shape to our west. A shortwave will ride along that boundary
and clip our northern areas, with generally isolated to scattered
showers/storms. A wetter pattern looks to be shaping up for the end
of next week as the boundary stalls over the area.

16

&&

.AVIATION...
(12Z TAFS)
Issued at 704 AM CDT FRI MAY 17 2024

Unsettled weather is expected for this forecast period as several
waves of rain and thunderstorms impact the area. Terminals start
off with VFR cigs and fall to MVFR with the arrival of showers
and storms this morning. A mix of IFR and MVFR cigs are expected
by the afternoon. With several waves of convection, and
uncertainty with timing, have used tempos and PROB30s to indicate
the most likely periods of storms. Terminals across the south
could have a prolonged period of moderate to heavy rainfall with
lightning. Winds will increase from the southeast this morning at
6-8kts and then veer to the south this afternoon. Stronger gusts
are possible with convective activity.

14

&&

.FIRE WEATHER...

Widespread rainfall and thunderstorms are expected through
Saturday, along with some lingering scattered activity hanging
around through Sunday. Minimum relative humidity values remain
well elevated through Sunday. Southeast to southerly 20 foot
winds increase to 8 to 10 mph today, and then become southwesterly
on Saturday. Drier conditions return by Sunday evening, with 20ft
winds becoming northerly at 5-10mph.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     74  63  80  61 /  90  40  80  30
Anniston    75  65  80  63 /  90  50  80  30
Birmingham  76  66  81  64 /  90  40  70  20
Tuscaloosa  77  66  82  64 /  90  40  70  20
Calera      76  66  80  65 /  90  50  80  30
Auburn      77  67  78  65 /  90  70  80  30
Montgomery  81  69  81  65 /  90  70  80  30
Troy        82  69  79  65 /  80  70  80  30

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...14
LONG TERM....16
AVIATION...14