Small Craft Advisory 48, NWS Mobile, AL

Area Forecast Discussion
National Weather Service Mobile AL
1149 AM CST Tue Nov 14 2023

...New AVIATION, NEAR TERM...

.AVIATION...
(18Z TAFS)
Issued at 1142 AM CST Tue Nov 14 2023

Poor ceilings (cigs) and reduced visibilities (vsbys) will
prevail through the TAF forecast period as deep moisture overruns
a cool stable airmass at the surface. IFR to occasional LIFR cigs
can be expected through at least 18z Wednesday along with IFR
vsbys. Strong winds can also be expected at all sites beginning
late this afternoon and continuing through Wednesday. Sustained
east to northeast winds between 15 and 25 kts, with gusts
potentially exceeding 30 kts at times can be expected. There may
also be some wind shear across interior southwest and south
central Alabama into southeast Mississippi as a strong
southeasterly low level jet overspreads weaker northeast winds
near the surface as compared to the coastal TAF sites. /JLH

&&

.NEAR TERM...
(Now through Wednesday)
Issued at 1142 AM CST Tue Nov 14 2023

For a rather straightforward forecast with respect to rain,
todays forecast was rather complicated and complex in trying to
determine any potential impacts. The overall pattern is rather
straightforward as a negatively tilted shortwave moves across the
deep south through Wednesday and cuts off into a closed low just
off our coast. At the surface, a surface low will quickly develop
along a stalled boundary roughly 80 miles south of the Alabama
coastline. This low is expected to quickly strengthen late Tuesday
night into Wednesday. Given the location of the low, continued
overrunning precipitation is expected as the warm front slowly
moves northward into our marine areas. Pockets of heavier rain
will likely approach the coastline this afternoon and steady
moderate rain will likely continue through Wednesday as precip
wraps around the developing low. Wet and dreary is the
straightforward part of this forecast, the rest of the impacts are
not so obvious.

Now lets talk impacts and as usually will break them apart by
impact.

Rainfall...Luckily with the current forecast heavy rainfall concerns
have certainly diminished. The main reason is the warm front and
associated heavier rainfall is expected to remain further offshore
than originally anticipated. This will likely lead to a more
steady rain rate and areas to pickup much beneficial rain. To be
honest this is the best case scenario. Expect a widespread 1 to 3
inches with lower amounts further north and higher amounts near
the coast. A few localized areas along the I-10 corridor may
approach 4 to maybe 5 inches if all things go right. The one thing
to monitor is the location of the warm frontal zone. If this zone
creeps northward towards the coast as the low occludes, then
maybe some heavier rainfall rates could sneak into the coastal
Florida Panhandle.

Coastal Hazards...With most coastal lows this time of year we can
expect a plethora of coastal hazards. The easy one will be high surf
and a high risk of rip currents. Wave heights are expected to
approach 6 to 9 feet Tuesday through Wednesday leading to life
threatening surf conditions. Winds over the water have been trending
upwards and as a result so have waves which may warrant a high surf
warning later this afternoon. For now, confidence is still too low
but we will certainly be on the upper end of advisory conditions. The
next piece of the puzzle is coastal flooding. This is rather tricky
and took some in-depth considerations. Typically strong easterly
winds are not the most conducive for coastal flooding; however,
Probabilistic Extra-Tropical storm surge guidance (PETSS) is hinting
at some coastal flooding along our southwesterly facing beaches
across the Florida Panhandle and Alabama. Whats tricky is this is
not the normal signal, but we are moving into the highest tides of
the month. Add on the fact of potential wave runup from large
breaking waves there certainly is an argument for some significant
beach erosion and likely some overwash in the usual problem areas.
What adds to the complexity has to do with how currents work. In
the ocean, deeper currents typically move perpendicular to the right
of the wind. Which means despite the wind being alongshore, the deep
current will be pushing against the coastline adding to the forward
push of breaking waves and potentially increasing the overwash. Even
our near-shore wave prediction model (NWPS) is picking up at some
overwash potential at the usual trouble spots of the west end of
Dauphin island and Ft. Pickens in Pensacola. We held off on a
coastal flood advisory this go around given the localized nature and
uncertainties in the forecast but if trends are stronger on wave
heights then we will likely need a coastal flood advisory for the
immediate coastline.

Gusty Winds...With the low strengthening and occluding just off our
coastline, gusty winds will likely be possible along the immediate
coast. Overall deep layer stability will likely limit the winds
further inland but locations modified by warmer water temperatures
could see wind gusts up to 45 mph on Wednesday. BB/03

&&

.PRELIMINARY POINT TEMPS/POPS...
Mobile      52  62  55  70  57  73  54  70 /  90  80  40  20  10  10  10   0
Pensacola   55  64  59  70  61  73  58  70 /  90  90  50  30  10  10  10   0
Destin      57  67  61  72  63  75  59  73 /  90  80  50  40  10  10  10   0
Evergreen   49  60  52  69  55  73  51  69 /  90  70  40  30  10  20  20   0
Waynesboro  48  59  51  67  53  71  51  67 /  90  60  40  20  10  20  20   0
Camden      46  57  49  67  51  69  49  64 /  90  70  40  30  10  20  20   0
Crestview   50  63  54  70  56  74  52  72 /  90  80  50  30  10  10  10   0

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...High Rip Current Risk through late Thursday night for ALZ265-266.

     High Surf Advisory from 6 PM this evening to noon CST Thursday
     for ALZ265-266.

     Wind Advisory from 6 PM this evening to midnight CST Wednesday
     night for ALZ265-266.

FL...High Rip Current Risk through late Thursday night for FLZ202-204-
     206.

     High Surf Advisory from 6 PM this evening to noon CST Thursday
     for FLZ202-204-206.

     Wind Advisory from 6 PM this evening to midnight CST Wednesday
     night for FLZ202-204-206.

MS...None.
GM...Small Craft Advisory until 6 AM CST Thursday for GMZ630-633>636.

     Small Craft Advisory until 9 PM CST this evening for GMZ631-632.

     Small Craft Advisory from 6 PM Wednesday to 6 AM CST Thursday
     for GMZ631-632.

     Gale Warning from 9 PM this evening to 6 PM CST Wednesday for
     GMZ631-632.

     Small Craft Advisory until noon CST today for GMZ650-655-670-675.

     Small Craft Advisory from 6 PM Wednesday to noon CST Thursday
     for GMZ650-655-670-675.

     Gale Warning until 6 PM CST Wednesday for GMZ650-655-670-675.

&&

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