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fxus64 kmob 172054 

Area forecast discussion
National Weather Service Mobile Alabama
354 PM CDT Thu Oct 17 2019

Near term /today and tonight/...during the next twelve hours,
potential tropical cyclone 16, now in perhaps its developing
stages over the southwestern Gulf of Mexico, gets picked up by an
upper air trough currently moving east out of S Texas. The feature
then undergoes an extratropical transition as it encounters rather
strong vertical wind shear while moving into the central Gulf of
Mexico. Impact- wise we will have a gale event over our coastal
waters and along the beaches tomorrow through Saturday. The
downstream anticyclonic cloud shield is already overspreading the
region as of this writing and clouds further thicken overnight as
surface winds gradually increase closer to the coast by sunrise.
Surf along area beaches also builds overnight. A high surf
advisory is in effect for 5 to 7 feet breaker heights. There will
also be a high risk of rip currents developing overnight and this
will endure for a few days due to onshore swell.

Tomorrow morning, winds continue to increase steadily during the
morning hours along the immediate coast and likely reach tropical
storm force by mid-afternoon as the surface low approaches. Rain
overspreads most of the region through late morning on and it will
rain though mid-morning Saturday with gradual tapering from the west
during the day on Saturday. Rain will be heavy at times closer to
the coast late Friday, Friday night and Saturday. At this time,we do
not anticipate issuing a Flash Flood Watch, however isolated areas
of flash flooding are possible mainly over the coastal portions of
the Alabama and western Florida coastal counties. Antecedent
conditions have been dry and average rainfall amounts, even in the
areas that will receive highest amounts of rainfall are not forecast
to exceed a general 2-4 inches. Isolated rainfall totals could range
as high as 4-6", again, primarily close to the coast. Overnight lows
tonight in the upper 40s north of Highway 84 ranging to around 60
degrees on the beaches. Highs tomorrow mainly in the 60s with lower
70s along the coast.

Coastal flood advisories have also been issued for area sounds and
bays at the time of high tide, especially very early Saturday
morning. Water may be slow to subside on Saturday even with falling
tides. The good news is that as storm passes further to our
southeast, surface winds take on more of a northeasterly component
(versus east). /23 jmm

Short term /tomorrow night through Saturday/...the upper- and lower-
level circulation centers become vertically stacked by tomorrow
evening and then the upper trough actually opens up as it outruns
the surface low Friday night. The surface low nears landfall
somewhere in the western Florida Panhandle between Destin and
Apalachicola, Florida (in this general area) Saturday morning. Latest
guidance has trended a few hours later. Some members are still a bit
west and some are a bit east, but this is the latest thinking. As
mentioned above rain ends from the west on Saturday as the cyclonic
wrap-around rainshield translates eastward with the mid- and upper
portion of the system. /23 jmm

Extended short term /Saturday night through Sunday night/
Sat evening the main circulation from tropical cyclone 16 will
move well to the east of the forecast area, generally located over
lower and central parts of GA, picked up by a dampening short
wave trof moving east of the MS River Valley by Sat evening. In
the wake of this system expect a short period of zonal flow aloft
through early Sun afternoon followed by a deepening long wave
trough approaching from the west tracking east over the Central
Plains Sun night then towards the MS River Valley and north
central Gulf states on Mon. With this pattern expect clearing
skies generally from west to east Sat night through sun evening
followed by better clouds from the north and west as the main
upper trof to the west approaches. Expect a light to occasionally
moderate northerly flow in the wake of tropical cyclone 16 Sat
night through early Sun morning shifting to the east then
southeast during the day on sun in response to the approaching
system to the west.

Temperatures will be 3 to 5 degrees above seasonal norms both Sat
night through sun then slightly higher Sun night. Humidity levels
will lower in the wake of the tropical system Sat night through
early Sun afternoon then steadily increase Sun afternoon and Sun
night due to the better onshore flow at the sfc. 32/ee

Long term /Monday through Wednesday/ Mon the deepening
upper trough will continue to move east across the Central
Plains states with a strong surface cold front moving from East
Texas to the lower MS River Valley early Mon through Mon evening.
Ahead of the front expected scattered to numerous showers and
thunderstorms to develop moving into western sections of the
forecast area Mon afternoon then shifting east across remaining
areas of the forecast area Mon evening and Mon night. Model
guidance does show marginal instability and vertical shear ahead
of the main upper system and surface cold front Mon afternoon
through much of Mon night leading to the potential for a few
strong to possible severe thunderstorms late Mon and Mon evening,
generally during the better heating of the day. Damaging straight
line winds, large hail and isolated tornadoes will be the main
threats with the stronger storms later in the day on Mon
continuing into Mon night. Stay tuned to local updates on this
developing pattern as we near the first part of next week. For Wed
expect clearing skies generally from west to east early followed
by better sunshine later in the day. A light to moderate northerly
flow early Wed morning will shift mostly east later in the day.

Ahead of the front temperatures will be 5 to 8 degrees above seasonal
norms through Mon night then 5 to 8 degrees below seasonal levels
Tue and tues night. For Wed daytime temps will rebound to near
seasonal levels by early afternoon. 32/ee


Marine...easterly winds and seas will steadily build tonight
through Friday afternoon as tropical cyclone 16 approaches the
marine area from the southwest then shift mostly north as the
system continues to track northeast south of the Pensacola towards
the Destin/Apalachicola coastline. Expect tropical storm force
winds from the east southeast to develop offshore by mid to late
Fri morning then spread northward over remaining areas including
inland bays and sounds by mid to late afternoon on Fri...shifting
from the north late Fri evening through Sat morning. Expect
numerous showers and thunderstorms mostly in squalls with this
system Fri through early Sat evening shifting east of the marine
area Sat evening and Sat night. Seas will build to 16 to 19 feet
out to 60 nm by late Fri afternoon with waves building to 2 to 4
feet over inland bays and sounds. 32/ee


Preliminary point temps/pops...
Mobile 73 54 68 59 77 61 82 67 / 0 20 50 60 50 20 0 10
Pensacola 74 60 72 64 77 65 81 71 / 0 20 60 90 70 30 10 10
Destin 74 63 74 65 76 67 80 72 / 0 20 70 90 80 30 10 20
Evergreen 72 52 69 58 74 59 82 64 / 0 10 30 70 60 30 0 10
Waynesboro 70 49 67 55 74 56 79 62 / 0 10 20 40 40 10 0 10
Camden 71 49 69 58 72 58 80 63 / 0 10 10 60 50 20 0 10
Crestview 74 54 71 60 76 59 84 64 / 0 10 50 80 70 30 10 10


Mob watches/warnings/advisories...
Alabama...high rip current risk from 7 PM CDT this evening through Sunday
morning for alz265-266.

Tropical Storm Warning for alz263>266.

Coastal flood advisory from 7 PM this evening to 7 am CDT
Saturday for alz263>266.

High surf advisory from 7 PM this evening to 7 PM CDT Saturday
for alz265-266.

Florida...high rip current risk from 7 PM CDT this evening through Sunday
morning for flz202-204-206.

Tropical Storm Warning for flz201>206.

Coastal flood advisory from 7 PM this evening to 7 am CDT
Saturday for flz202-204-206.

High surf advisory from 7 PM this evening to 7 PM CDT Saturday
for flz202-204-206.

GM...Tropical Storm Warning for gmz630>636-650-655-670-675.


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