217
FXUS64 KMOB 241129
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
629 AM CDT Tue Sep 24 2024

...New AVIATION...

.AVIATION...
(12Z TAFS)
Issued at 629 AM CDT Tue Sep 24 2024

A few patches of fog will be present early this morning and will
be possible again tonight, and could be accompanied with an MVFR
ceiling late in the night. A stray shower or storm is possible
this afternoon, and isolated to scattered showers and storms are
possible late tonight for much of the area. A southerly flow at 5
to 10 knots develops today, then winds become light and variable
this evening. /29

&&

.PREV DISCUSSION... /issued 438 AM CDT Tue Sep 24 2024/

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

NEAR TERM...
(Now through tonight)
Issued at 438 AM CDT Tue Sep 24 2024

A longwave trof over the central states continues to amplify while
advancing to roughly along the lower/mid Mississippi River valley to
the Great Lakes through tonight. An associated surface low well off
to the north brings a weak trailing frontal boundary from the
southern/central Plains into central Mississippi and northern
Louisiana by the end of the period. A modest surface ridge oriented
along the northern Gulf coast weakens today and retreats from the
area tonight as the front approaches. A light southerly flow is
established today over the area then looks to become light and
variable tonight. Have kept mention of precipitation out of the
forecast for today (although can`t rule out a stray shower or
storm), then will have slight chance to chance pops developing
overnight in response to the approaching frontal boundary and also
some peripheral response to Potential Tropical Cyclone Nine (PTC9)
expected to emerge in the south central Gulf by late in the night.
Please see the National Hurricane Center for more information on
PTC9. Highs today will be in the lower 90s except for around 90 at
the coast. Lows tonight range from the upper 60s well inland to the
lower/mid 70s at the coast. A low risk of rip currents is expected
through tonight. /29

SHORT TERM...
(Wednesday through Thursday night)
Issued at 438 AM CDT Tue Sep 24 2024

An upper level longwave trough is expected to dig southeastward
on Wednesday before breaking off from the northern jet stream on
Thursday. This results in an anomalously large upper low that
essentially parks itself over the Mississippi River Valley. This
low is responsible for two things: 1) helping to send a frontal
boundary into the region from the west, and more importantly 2)
keeping the core of Potential Tropical Cyclone 9 (PTC9) to our
east. For Wednesday, the front will begin moving into our local
area from the west. Plenty of forcing due to strong diffluence
aloft and convergence along the front, in addition to ample
moisture, will result in numerous to widespread showers and storms
across the area, especially in the afternoon. The front should
stall somewhere near the I-65 corridor by Thursday evening,
allowing for high rain chances to continue (especially along and
east of it) through Wednesday night. By Thursday, all eyes point
to the Gulf as PTC9 strengthens and begins it`s sprint to the
north-northeast. Models have come into very good agreement over
the past 24 hours, with a good majority of the operational models
and their ensembles tightly clustered on a landfall in the Florida
Big Bend area sometime late Thursday. Rapid strengthening is also
anticipated, resulting in a likely landfall as a major hurricane
in that area. Thankfully for our local area, the center should be
far enough away for us to be spared from the hurricane force
winds. However, as this system quickly lifts northward, it is
expected to grow in size considerably and therefore we will still
see some impacts. Hazardous marine conditions (due to strong winds
and high waves), dangerously high surf (breakers near 10 feet),
and life threatening rip currents are expected, especially as we
get into the Thursday afternoon through Thursday night timeframe.
We will also be monitoring for the potential of, at least, minor
coastal flooding along the coastal interface going into Thursday
night. As far as rainfall, we are currently anticipating a general
2 to 5 inches (locally higher possible) over south central
Alabama and the western Florida Panhandle through this entire
period, with lower amounts for southwest Alabama and southeast
Mississippi. This rainfall could lead to isolated to scattered
instances of flash flooding, especially over urban and poor
drainage areas, and some minor river flooding cannot be ruled out.
And lastly, tropical storm force winds are possible primarily for
the eastern half of our CWA starting as early as Thursday
morning. Probabilities currently sit at 10-20 percent over
portions of south central Alabama, the western Florida Panhandle,
and along the immediate Alabama coast, with lower probabilities
elsewhere. We will continue to monitor the progress of PTC9
closely, as any shifts to the west will likely bring stronger
impacts. /96

LONG TERM...
(Friday through Monday)
Issued at 438 AM CDT Tue Sep 24 2024

Per the latest track from the National Hurricane Center on PTC9, the
system is anticipated to be over northern Georgia/Carolinas by
Friday and soon becomes absorbed into a rather anomalous large upper
low centered over the lower Mississippi River valley.  The large
upper low lumbers to over the Mississippi/Ohio River confluence by
Sunday then breaks down to an open trof over the eastern states by
Monday. Drier air is anticipated to be in place over the area on
Friday, then steadily improves over the eastern portion of the area
Saturday into Sunday. Have continued with a dry forecast for Friday
and Saturday, then slight chance pops return to east of I-65 for
Sunday afternoon. This improvement in deep layer moisture proves
short-lived however, with drier air later flowing into the area by
Monday, so have gone with a dry forecast for Monday. /29

MARINE...
Issued at 438 AM CDT Tue Sep 24 2024

Based on the latest track from the National Hurricane Center on
PTC9, prob34 values are sufficient to trigger Tropical Storm
Conditions Possible wording in the open Gulf waters and
Choctawhatchee Bay during Thursday into Thursday night. Please see
the National Hurricane Center for more information. Depending on
subsequent updates to the track for PTC9 and if expansion of a
Tropical Storm Watch into our area remains not necessary, may need
to include a Small Craft Advisory for much of the marine area
beginning late Wednesday night which continues until seas subside
Friday morning. Winds and seas will be higher near storms. /29

&&

.PRELIMINARY POINT TEMPS/POPS...
Mobile      91  70  88  70  81  65  84  66 /   0  10  70  70  50  10   0   0
Pensacola   89  74  86  73  81  69  83  72 /   0  30  80  80  80  20   0   0
Destin      89  75  85  74  82  72  83  72 /  10  40  80  80  80  30   0   0
Evergreen   93  69  86  70  80  66  84  62 /   0  20  80  80  80  40  10   0
Waynesboro  92  69  86  67  80  63  83  61 /  10  30  60  50  50  20  10   0
Camden      91  68  86  68  78  65  80  62 /   0  20  80  70  70  40  10   0
Crestview   92  70  86  71  80  66  84  63 /  10  30  80  80  90  30  10   0

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...None.
FL...None.
MS...None.
GM...None.
&&

$$

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