161
FXUS64 KMOB 150903
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
403 AM CDT Thu Aug 15 2024

...New NEAR TERM, SHORT TERM, LONG TERM, MARINE...

.NEAR TERM...
(Now through Tonight)
Issued at 403 AM CDT Thu Aug 15 2024

Clear and calm conditions persist across the area early this
morning, with relatively mild temperatures expected for the predawn
hours. Upper ridging will generally remain in place through the near
term period, retreating just a bit to the west today. This will keep
temps from climbing into the triple digits like we observed
yesterday. That said, though the air temperature may not be as hot
as yesterday, humid conditions will continue and heat indices will
climb into the triple digits once again this afternoon. Weaknesses
in the ridge, combined with an abundance of moisture, will enhance
any diurnally driven thunderstorms that are able to initiate along
the seabreeze and any lingering surface boundaries. Coverage will be
scattered and any storms that are able to develop will produce
locally heavy rainfall and gusty winds.

Similar conditions are expected for tonight, as high pressure
maintains its hold on the weather pattern. Temperatures will be mild
once again during the overnight hours, with clearing skies and temps
falling into the lower 70s across our northern areas to the upper
70s along the coast. /73

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 403 AM CDT Thu Aug 15 2024

The upper ridge will begin to weaken on Friday as a closed upper low
deepens over the Great Lakes and drifts southward. Highs will climb
into the lower to mid 90s once again Friday afternoon, though
slightly lower dewpoints will keep heat index values lower. HREF
probabilities of heat indices reaching 108 are less than 10%, so
will hold off on issuing a Heat Advisory for Friday. Scattered
thunderstorms will be possible once again on Friday afternoon, with
higher coverage along the coast. Forecast soundings show slightly
more dry air aloft tomorrow, with gusty winds possible. Any
lingering thunderstorms tomorrow evening will quickly diminish by
sunset. This will leave another mild night on tap to start the
weekend, with overnight lows in the lower to mid 70s.

The aforementioned closed low will slowly move southward through the
day on Saturday, with the ridge retreating to the west. The forecast
area will be on the eastern fringe of the ridge and the southern
periphery of the trough, with northwest flow aloft. Diurnally driven
thunderstorms will develop once again on Saturday , with perhaps
slightly higher coverage along our northern area. These may linger
into the evening hours as the trough amplifies, though a lack of
surface forcing will limit the coverage during the overnight period
and storms should diminish by midnight. Temperatures will be a
couple of degrees cooler Saturday night, with lows in the lower to
mid 70s once again. /73

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 403 AM CDT Thu Aug 15 2024

An anomalously deep
upper-level trough for this time of year is expected to dig into the
Southeast US during the first half of the period. In fact, model
guidance across the board (deterministic runs and ensembles alike)
have been trending stronger with this trough over the past few runs
and are in rather good agreement that the base of this trough may
reach as far south as the Florida Panhandle. As this trough digs in,
deep northwesterly flow aloft will set up across the forecast area
for the entire period. The trough, although remaining in place
through midweek, will start to weaken by Tuesday and Wednesday.
Looking at the surface, the digging trough will help to send a
frontal boundary into our area Sunday night into Monday. With the
upper trough trending stronger, guidance is now suggesting that the
front may pass cleanly through our area, potentially stalling over
the northern/central Gulf. If this solution pans out, then a much
drier airmass will push into the region for Monday through Wednesday
(more about this later).

Sunday will likely feel hotter and be more active in comparison to
the remainder of the long term. Prior to the arrival of the front,
deep moisture will still be in place, with PWATs around 1.8 to 2.1
inches. This, paired with strong instability and forcing induced by
diffluence aloft out ahead of the upper trough and surface
convergence due to the approaching front, will result in the
development of scattered showers and storms, mainly during the
afternoon/evening hours. One thing we will need to watch is that as
the upper trough moves into our area, deep-layer shear will also be
on the increase (0-6km shear around 25 to 35 knots). This may help
to support the organization of multicellular clusters or an MCS
along/ahead of the surface boundary. Given the strong instability in
place (CAPE values over 2000 J/kg and DCAPEs over 1200 J/kg), any
bowing segment within this MCS could be capable of producing gusty
to damaging winds. We will continue to monitor trends over the
coming days. Otherwise, with highs generally in the mid 90s and dew
points in the mid to upper 70s, another Heat Advisory may become
necessary for portions of the area, prior to the arrival of storms.
Rain chances quickly decrease Sunday night as the front pushes
through the area.

For the remainder of the week, a much drier airmass advects into the
area from the north as a large high pressure builds into the Great
Lakes region. PWATs look to plummet to around 0.75 to 1.0 inches,
which, climatologically speaking, is around the 10th percentile for
our area for this time of year. Dew points also follow suit..
possibly dropping into the low to mid 60s for most spots. Although
highs look to remain in the mid 90s, the lower dew points should
help to keep heat indices in check. Lows have also been trending a
bit cooler given the drier airmass in place. Lows for Monday and
Tuesday nights look to range from the mid to upper 60s to around 70
degrees for locations along and north of the I-10 corridor, to the
low 70s along the coast. /96

&&

.MARINE...
Issued at 403 AM CDT Thu Aug 15 2024

A light offshore flow will become southerly later this morning,
following our typical diurnal pattern. Flow will increase from the
south on Friday, with light to occasionally moderate onshore flow
continuing in the weekend. Isolated to scattered thunderstorms
will remain possible. No impacts are expected outside of locally
higher winds and seas near thunderstorms. 73

&&

.PRELIMINARY POINT TEMPS/POPS...
Mobile      95  77  93  76  95  75  96  73 /  50  20  60  10  40  30  30  20
Pensacola   92  80  92  78  93  77  96  76 /  50  30  40  10  30  30  30  30
Destin      91  80  91  79  92  78  93  77 /  40  40  30  10  20  30  30  30
Evergreen   95  74  94  72  96  72  95  70 /  30  10  30  10  40  30  30  20
Waynesboro  97  74  95  72  97  71  96  70 /  30  10  50  10  50  30  20  20
Camden      94  74  94  73  94  71  93  69 /  20  10  30  20  50  30  20  20
Crestview   94  74  94  72  96  73  96  72 /  40  20  20   0  30  30  30  30

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for ALZ052-261>266.

FL...Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for FLZ201>204.

MS...Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for MSZ067-075-076-078-079.

GM...None.
&&

$$

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