Area Forecast Discussion
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FXUS62 KTAE 211947
AFDTAE

Area Forecast Discussion
National Weather Service Tallahassee FL
347 PM EDT Mon May 21 2018

.NEAR TERM [Through Tonight]...

The feature to watch through the overnight hours is the weak surface
low just southwest of Panama City. Models show this feature drifting
slowly northward through the overnight hours. Deep tropical moisture
is in place across the area with bands of showers and thunderstorms
on the eastern side. Pockets of heavy rain are the main threat
through the overnight hours. If any training occurs, then flash
flooding on a very localized scale could occur, similar to what we
saw this morning in southwest Wakulla county. However, due to the
uncertainty and the expected isolated nature of the flooding should
it occur, we`ve opted not to issue a large scale flash flood watch
for now. Instead, a mention of heavy rainfall was added to the point
and click forecast for the western half of the area. Overnight lows
will generally be in the upper 60s to lower 70s.


.SHORT TERM [Tuesday Through Wednesday Night]...

At the start of the period, a weak surface low pressure area will
be moving inland across the Fla Panhandle and into Srn Alabama.
This feature is expected to continue to be a focus for morning
rainfall across the western half of the region. Some of this rain
could be locally heavy. Model guidance was a little split on PoP
chances, but with a very moist tropical airmass in place and some
heating, at least 60-70 percent PoPs seem reasonable for Tuesday
afternoon. While locally heavy rainfall is possible, storm motion
should still be fast enough to prevent any widespread flood
concerns.

The surface low pressure area dissipates by Tuesday night but
with sufficient moisture in place, shower and thunderstorm
activity should continue well into the evening, but then taper off
after midnight.

On Wednesday, there doesn`t appear to be any large scale trigger
for shower and thunderstorm activity, so storms are expected to be
more diurnal in nature. Storms should begin developing by late
morning and continue through the afternoon hours. Went about 10-20
percent higher than guidance for an afternoon PoP forecast around 70
percent most areas, which is more typical for a summertime southerly
flow regime.

Temperatures through the short term period will be below normal
during the daytime hours due to all the convective activity but
above normal overnight, possibly in the low 70s for a few places.


.LONG TERM [Thursday Through Monday]...

The latest model runs continue to indicate a low and upper-level low
developing in the Gulf on Thursday. There is considerable
disagreement on track and intensity between models at this time. The
12Z EURO has the low moving north from the Yucatan towards Louisiana
and Mississippi. The 12Z GFS, on the other hand, shows the low
moving northeast and turning further north along the western coast
of Florida. Despite the current lack of consensus, the latest
runs of both have shifted towards more agreement in comparison to
previous runs. Based on this guidance, a sub-tropical or tropical
system affecting the CWA is certainly possible in the long term
period. Regardless of how the system develops, higher PoPs can be
expected. High temperatures will stay in the 80s throughout the
period and lows will remain steady around the upper 60s and lower
70s.

&&

.AVIATION [Through 18Z Tuesday]...

Scattered showers and thunderstorms expected through the
afternoon at all terminals sites. Expect these storms to bring IFR
conditions for brief moments with borderline MVFR/VFR conditions
expected outside any activity. Storm activity reduces later
tonight, but abundant moisture in the region should yield
widespread IFR cigs overnight. Gradual improvement is anticipated
Tuesday morning but another round of showers and thunderstorms
will bring additional restrictions.


&&

.MARINE...

Despite a stormy weather pattern through the week, winds and seas
should be fairly low outside of thunderstorms given the weak
pressure pattern. An increase in winds and seas is expected by
Friday as a tropical disturbance moves into the Southern Gulf of
Mexico. Advisory conditions are possible across the marine area
thereafter.

&&

.FIRE WEATHER...

With ample moisture and light winds across our area there are no
fire weather concerns through the next several days.

&&

.HYDROLOGY...

Early this morning, a narrow band of heavy rainfall trained over
coastal Wakulla County near Sopchoppy and produced an estimated
8-11 inches of rainfall in a 6 hour time period. This resulted in
significant rises on the Sopchoppy River. Because the bulk of the
heaviest rainfall (and associated river rises) occurred below the
gauge site, an areal flood warning was issued for Sopchoppy and
will remain in effect for this area through the overnight hours.

Rainfall elsewhere was generally in the 1-2 inch range overnight
with some isolated heavier totals. As a result, we`re beginning to
overcome the recent dry conditions and flooding is becoming more
of a concern.

Over the next couple of days, model guidance suggests an increased
potential for flooding across Southeast Alabama and the Florida
Panhandle along the backside of a departing area of low pressure,
much as occurred this morning in Sopchoppy. Since the threat is
localized, a flood watch won`t be issued at this time. However
there is potential for storms to produce a quick 2-5 inches of
rain with isolated heavier totals in some areas overnight through
Tuesday.

Longer term, the wet pattern is expected to continue into next
week. While it is too early to speculate on rainfall amounts, the
persistent wet pattern suggests that the flood risk will continue
to increase through the week.

Most of the rivers have now moved well off base flows and by the
end of the week, some of the larger-stem rivers will need to be
monitored for the potential for minor flooding depending on where
the heaviest rain sets up for this weekend.

&&

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.

&&

.PRELIMINARY POINT TEMPS/POPS...

Tallahassee   70  85  68  85  70 /  50  60  50  70  50
Panama City   73  82  71  83  73 /  70  70  50  60  40
Dothan        69  83  68  85  70 /  70  80  60  70  50
Albany        70  85  68  86  70 /  50  70  50  70  50
Valdosta      69  85  66  85  69 /  40  60  40  70  40
Cross City    69  85  67  86  70 /  50  60  40  60  40
Apalachicola  73  82  72  82  73 /  60  50  40  50  40

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 2 AM EDT Tuesday for Coastal
     Franklin.

GA...None.
AL...None.
GM...None.
&&

$$

NEAR TERM...DVD
SHORT TERM...Godsey
LONG TERM...Skeen/Godsey
AVIATION...DVD
MARINE...Godsey
FIRE WEATHER...Barry
HYDROLOGY...Godsey


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