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fxus64 kmob 221821 
afdmob

Area forecast discussion
National Weather Service Mobile Alabama
1221 PM CST Fri Nov 22 2019

Discussion...see updated information for land areas below.

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Update...adjusted pops this afternoon and into the overnight
slightly based on current radar trends and hi-res model guidance.
Models are showing slight chances of a few showers ahead of the
cold front. In fact, a few light showers have popped up on radar
in a few of our western counties in the last hour or so.
Therefore, expanded areas of slight chance pops eastward to
account for this. The rest of the forecast is generally on track
this afternoon. /26

&&

Previous discussion... /issued 1136 am CST Fri Nov 22 2019/

Discussion...updated for latest aviation discussion below.

Aviation...
18z issuance...VFR conditions are expected to continue through
this afternoon. As a front approaches the region, showers will be
on the increase from the northwest late this evening and through
the overnight. The other concern will be the potential for sea fog
development along the coast tonight. Included MVFR visible to account
for this for all taf sites. The heaviest showers are then
expected by tomorrow morning as the front progresses over the
region. Cigs will lower to at least MVFR for mob and bfm during
this time as well. Pns cigs will lower, but sub VFR cigs are not
expected until after the taf period. Winds will be between 5 and
10 knots from the southwest through the period, but some gusty
winds are possible by tomorrow afternoon, particularly for the Florida
Panhandle. /26

Previous discussion... /issued 533 am CST Fri Nov 22 2019/

Discussion...updated for latest aviation discussion below.

Aviation...
12z issuance...VFR conditions will continue this morning with a
few areas of light mist/ground fog across the area. Fog should
mix out by sunrise as low-end VFR to upper-end MVFR cigs could
develop with the diurnal heating. Will need to monitor the
potential of some fog tomorrow night along the coast. Bb/03

Previous discussion... /issued 436 am CST Fri Nov 22 2019/

Near term /now through Friday night/...the mid-level ridge axis
will continue to flatten out as an upper trough pushes east over
the Great Lakes region. At the surface, high pressure will remain
parked off the East Coast of Florida as a surface trough
associated with the shortwave will dive southeast into the mid-
Mississippi Valley. Southerly winds will continue throughout the
day leading to increasing moisture. Mid- level clouds will
continue to in from the northwest during the afternoon as an upper
level low ejects over the central Great Plains. By tomorrow
night, the upper low and adjacent jet streak will begin to spread
over the surface trough leading to a surface low to develop along
the trough over southern Louisiana. Precipitation will slowly
begin to spread east and likely entering our northwestern areas by
early evening before slowly drifting southeast throughout the
night. There are some timing discrepancies especially between the
high-res guidance and the spectral models. I leaned a little
towards the slower solution given the slowing trend.

For temperatures today, increasing clouds will likely keep
temperatures from getting too warm; however, increasing warm air
advection throughout the day should lead to highs in the mid 70s
across the area. Lows tomorrow night will be on the warmer side as
dewpoints continue to rise. Lows will likely range from the upper
60s at the coast to low 60s inland. Some areas of sea fog could
develop along the coastal areas tonight into early Saturday morning
as warm moist air flows over the cooler shelf waters near the coast.
Bb/03

Short term /Saturday through Sunday night/...a cold front will
move west to east across the area Saturday morning into Saturday
afternoon with a line of showers and a few thunderstorms ahead of
the front. Strong to severe storms are not expected as instability
levels will be limited by widespread clouds and weak mid-level
lapse rates. Heavy rainfall will not be an issue as the line is
expected to remain progressive. A cooler and drier airmass
follows in the wake of the front on Sunday as high pressure builds
over the area. Highs will be in the upper 60s to low 70s on
Saturday and low 60s on Sunday. /13

Long term /Monday through Thursday/...temps begin moderating on
Monday as high pressure moves east of the of the area as a trough
digs across the western states. This trough advances east and
causes low pressure to develop across the plains which tracks
rapidly northeast into the Great Lakes by Tuesday night. The
global models have trended farther to the north with the main
dynamics of this system which results in the trailing front
stalling somewhere over or close to the Gulf Coast. The stalling
scenario makes sense due to the strong ridging forecast to
develop across the Gulf of Mexico. Without a strong frontal
passage, temps remain above normal through Thanksgiving day and
rain chances will be dependent on just how far south the boundary
makes it. /13

Marine...light onshore flow will continue today as the surface high
remains over the western Atlantic. Some sea fog could be possible
late tonight into early Saturday morning as better moisture and
warmer temperatures surge north ahead of an approaching cold front.
Seas and winds will increase Saturday as the pressure gradient
strengthens ahead of the front. The strongest winds will likely
occur just ahead of the front during the afternoon. There are some
discrepancies in the timing of the front which would lead to
potential sifts in where the strongest winds will occur. Thus, have
went ahead and issued a Small Craft Advisory for the whole offshore
waters beginning Saturday morning. A few thunderstorms could be
possible ahead and along the front Saturday. Behind the boundary,
moderate northwesterly flow will develop Saturday night into Sunday
before relaxing Sunday night into Monday. The Small Craft Advisory
also includes the winds on the backside of the front. Bb/03

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Mob watches/warnings/advisories...
Alabama...high rip current risk from Saturday morning through late
Saturday night for alz265-266.

Florida...high rip current risk from Saturday morning through late
Saturday night for flz202-204-206.

MS...none.
GM...Small Craft Advisory from 9 am Saturday to 6 am CST Sunday for
gmz650-655-670-675.

&&

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