Area Forecast Discussion
Issued by NWS Mobile, AL

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FXUS64 KMOB 241131 AAA
AFDMOB

Area Forecast Discussion...UPDATED
National Weather Service Mobile AL
631 AM CDT SUN JUL 24 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...
12Z issuance...Predominate VFR conditions will continue through the
next 24 hrs. A few coastal showers have developed this morning and
thunderstorms are expected to increase in coverage by late morning
into the afternoon hours, starting near the coast and spreading
inland as the day progresses. Storms are expected to quickly fade
this evening, although an isolated storm will be possible along the
coast overnight. A light northeast wind this morning gradually
transitions to southeast by this afternoon, staying generally less
than 10 kt. 34/JFB

&&

.PREV DISCUSSION... /issued 355 AM CDT SUN JUL 24 2016/

NEAR TERM /Now Through Sunday night/...Like the past several days,
our region continues to be positioned on the eastern side of a large
scale upper level ridge. There is an upper low that has developed
over and east of the FL peninsula, but that feature will be too far
removed from our area to have any influence over today`s weather.
Precipitable waters have rebounded across much of the forecast area
and are expected to be in the 2-2.15 inch range across the southern
and western portions of the region. There is still some drier air
further to the northeast, with precip waters of less than 2 inches
across the south central Alabama zones. With the overall increase in
moisture for the majority of the area, we expect to see an uptick in
the areal coverage today with scattered storms developing, but more
isolated over the northeast zones. Marine convection will likely
increase toward daybreak, potentially impacting the immediate coast
after sunrise. Storm chances will gradually spread inland as the day
progresses. A few stronger storms are possible, with the typical
threats of frequent lightning, torrential downpours, and gusty
winds. Highs similar to yesterday in the low to mid 90s with
afternoon heat indices of 100 to 105.

Convection should diminish quickly by early evening with only a
slight chance of a storm along the immediate coast overnight. Lows
once again in the muggy low to mid 70s, with upper 70s along the
beaches. 34/JFB

SHORT TERM /Monday Through Tuesday night/...A weakly organized upper
low currently off the east coast of Florida moves west over the
northern Gulf coast to over the Mississippi river Valley by Tuesday
night, pushing a shortwave over the lower Mississippi River Valley by
Monday to the west. For Monday, as the first shortwave moves off, a
dryer airmass moves over the area from the east. The result is a west
to east gradient in PoPs for Monday, with high PoPs over western
portions of the fa. With the lower chance over eastern portions of
the fa, higher temps are expected over northeastern portions of the
fa, with highs ranging from the mid 90s northeast to around 90
southwest. Even with highs in the mid 90s, the drier air will help to
keep daytime heat indices from rising much above the 99 to 103 degree
range.

Monday night through Tuesday, as the weakly organized upper low
passes, a surge of moisture from over the gulf increases precip h20
values back into the 2-2.3" range. Guidance is advertising a strong
possibility of training cells moving off the Gulf as a surface trough
develops over the northern Gulf coast, and with 1hr FFG values
generally in the 2.5"-3" range, an increased chance of localize
water problem exists over the southern third of the fa. Will have to
keep an eye on this, but with this run the first to advertise this
possibility, am not going to issue any wwas. With the better chance
of rain, am expecting highs for Tuesday to rise to a bit below
seasonal levels over much of the fa ( around 90), a bit warmer well
inland.

Tuesday night, with the moisture levels remaining high over the fa,
am expecting overnight temps Tuesday night to fall to above seasonal
levels after the rain ends.

/16

LONG TERM /Wednesday Through Saturday/...guidance continues to
advertise an upper high building over the Southeastern states,
albeit a bit further east over the Atlantic coast. Shortwave energy
will continue to move in and maintain an upper trough over the
Mississippi River Valley the rest of the week and ultimately push the
upper high off next weekend. Guidance is inconsistent in the
placement of the transition zone between the upper trough and high
over the Lower Mississippi River and western half of the Southeast,
with the GFS painting a cooler/wetter forecast farther east (and over
western portions of the fa) then the ECMWF. Have went with a blended
approach for the extended, with the ensembles indicating a
compromise is the better approach. The result for the forecast is
temps a bit above seasonal and the chance of rain a bit below.

/16

MARINE...High pressure extending from the western Atlantic west
into the Gulf will persist through the week. This results in a
general light onshore flow with seas less than 2 feet. However, an
upper level disturbance moving west across the northern Gulf will
result in a slight increase in southerly flow Monday and Tuesday.
Isolated to scattered thunderstorms can be expected each day, with
coverage likely becoming more numerous on Tuesday. 34/JFB

&&

.MOB Watches/Warnings/Advisories...
AL...None.
FL...None.
MS...None.
GM...None.
&&

$$

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