Gale Watch 3, NWS Mobile, AL

Area Forecast Discussion
National Weather Service Mobile AL
1130 AM CST Sun Jan 19 2025

...New AVIATION, NEAR TERM...

.AVIATION...
(18Z TAFS)
Issued at 1130 AM CST Sun Jan 19 2025

VFR conditions prevail through Monday while strong northwesterly
winds continue across the area today. Expect strong wind gusts to
around 30 knots at times through this afternoon. Tonight winds
relax a little but remain northwesterly at 10 to 15 knots gusting
to 20 knots. Winds shift to the north-northeast for Monday at 10
to 15 knots gusting to 20 knots. MM/25

&&

.NEAR TERM...
(Now through Monday)
Issued at 1130 AM CST Sun Jan 19 2025

A much colder airmass will continue to move into the area today
in the wake of a strong cold front. The high temps for the day
have likely already occurred in most areas. Temps will hold steady
or fall through much of the day. Strong northwest winds will make
it feel even colder. Lows tonight will fall into the 17 to 20
degree range north of I-10 with low to mid 20s south of I-10. Wind
chill values will be in the low teens inland and low 20s along
the coast. The Extreme Cold Watch will be upgraded to a Cold
Weather Advisory for the overnight period tonight. A Moderate Risk
of rip currents continues today and tonight. /13

SHORT And LONG TERM...
(Monday through Tuesday night)
Issued at 349 AM CST Sun Jan 19 2025

An arctic airmass will have settled into the region at the start of
the new work week, with strong northerly flow keeping very cold
temperatures across the area. After a cold start to the morning,
with wind chills dipping into the teens, temperatures will only rise
into the upper 30s to lower 40s, and that may be a couple of degrees
too warm. Temperatures will drop into the teens to lower 20s
areawide on Monday night, though with slightly lower winds, wind
chills will generally remain in the teens. Still a very cold start
to the day, with very little relief from the sub-freezing
temperatures during the day.

Attention quickly turns to the winter storm potential on Tuesday.
Forecast guidance maintains some level of consistency on the overall
pattern, but the specific precip types and accumulation amounts
differ quite a bit. That's not necessarily surprising since we're
still at the day 3 timeframe, but consensus still points to a high
probability of us reaching Winter Storm criteria. Ensemble guidance
is all centering on a high chance (70-80%) of reaching, if not
exceeding 2 inches across much of the area. The real uncertainty
lies in whether or not we see more of a wintry mix, which will
bring the snow totals down, but increase the freezing rain and
sleet accumulations. Either way, given the colder airmass in place
ahead of the wintry precip, it won't take as much for
accumulations to occur on area roads. Regardless of specific
accumulation amounts, the impacts from any frozen precip will be
enough to warrant a Winter Storm Watch with this forecast package.

Digging into the details of the forecast setup leading into and
during the day Tuesday, a shortwave is expected to round the base of
the trough early Tuesday morning. A surface low developing off the
TX coast will quickly move eastward through the day. Meanwhile, an
axis of convergence aloft will aid the forcing associated with the
incoming trough for precip to develop and or continue making its
way into the area from the west. Despite the dry airmass in place
(surface dewpoints in the single digits!), southwest flow aloft
will increase moisture quite quickly Tuesday morning. Forecast
soundings show a fully saturated profile above 700 mb by Tuesday
morning, with quite a bit of forcing. The vertical column fully
saturates by late morning/early afternoon, as the best lift enters
the area. Again, the big question is whether or not the warm nose
can work its way in and I'm not all too confident that that's
going to happen. In fact, from a deterministic model standpoint,
it seems all but the NAM are leaning more towards the all snow
solution, with the NAM warming the 850-700 mb layer roughly 6
degrees between 15Z and 21Z. It's totally plausible, but one
reason I'm not buying that is the column above 700 mb becomes
saturated during this time and with quite a bit of forcing. This
suggests that we'll have ample snow falling which will help to
cool the vertical column and I'm not too sure that any WAA aloft
will be strong enough to overcome that.

Cluster analysis also shows roughly 40% of members (leaning heavily
on the ENS) centering on temps aloft remaining below 0 degrees for
the majority of the area. Even a warmer solution, favoring heavily
on the GEFS keeps temps aloft at or below freezing. We're talking a
difference in 1 degree, so it's too early to really try and narrow
that down, but something to certainly watch. As stated above,
regardless on specific amounts, this will be an impactful event and
potentially more impactful if we realize the sleet and/or freezing
rain potential. The mostly likely timeframe for wintry precip to
begin is late Tuesday morning, with precip coming to an end by
daybreak on Wednesday. Snowfall amounts will be dependent on the
duration and intensity, but ensemble means are generally between 1
to 2 inches for much of the area, with a swath of 2 to 3 inches
along and between the I-65 and I-10 corridors. There is a medium
chance (50-60%) that some areas exceed 3 inches, which has steadily
increased over the last few model cycles.

Any lingering precip will come to an end by Wednesday morning, and
the remainder of the forecast period will be cold and dry. How cold
it gets will heavily depend on any snow accumulations. Regardless, a
long duration cold event is expected, with temps remaining well
below normal through Friday. /73

&&

.PRELIMINARY POINT TEMPS/POPS...
Mobile      21  41  25  38  19  39  21  44 /   0   0   0  80  50   0   0  10
Pensacola   26  41  28  41  23  39  26  45 /   0   0   0  80  70   0   0  10
Destin      28  44  31  45  26  41  29  48 /   0   0   0  70  80  10   0  10
Evergreen   21  39  20  38  17  39  18  46 /   0   0   0  80  60   0   0  10
Waynesboro  19  38  21  33  14  40  17  45 /   0   0  10  80  20   0   0   0
Camden      20  36  19  34  14  37  17  42 /   0   0   0  80  40   0   0  10
Crestview   22  41  22  41  20  38  20  45 /   0   0   0  70  80   0   0  10

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...Cold Weather Advisory from 9 PM this evening to 11 AM CST Monday
     for ALZ051>060-261>266.

     Winter Storm Watch from Tuesday morning through late Tuesday
     night for ALZ051>060-261>266.

FL...Cold Weather Advisory from 9 PM this evening to 11 AM CST Monday
     for FLZ201>206.

     Winter Storm Watch from Tuesday morning through late Tuesday
     night for FLZ201>206.

MS...Cold Weather Advisory from 9 PM this evening to 11 AM CST Monday
     for MSZ067-075-076-078-079.

     Winter Storm Watch from Tuesday morning through late Tuesday
     night for MSZ067-075-076-078-079.

GM...Small Craft Advisory until noon CST Monday for GMZ630>636-650-
     655-670-675.

&&

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