Flash Flood Warning 44, NWS Tallahassee, FL

Area Forecast Discussion
National Weather Service Tallahassee FL
642 AM EDT Sat Jul 15 2023

...New AVIATION...

.NEAR TERM...
(Today and tonight)
Issued at 459 AM EDT Sat Jul 15 2023

Land breeze convection offshore is expected to move north throughout
the morning and transition to a sea breeze by late morning into the
afternoon. Unlike yesterday, our forcing for weather today will be
more diurnally forced with outflow boundaries playing a bigger role
on where convection fires off. That is to say, back to usual
summertime activity. It appears that late this afternoon and into
the evening and overnight hours, a shortwave looks to approach the
region from the northwest bringing with it some decaying upper-level
forcing for ascent. This is associated with an MCS that is currently
moving through NW Mississippi headed southeast in our direction. As
this MCS decays over the next few hours, it'll send an outflow
boundary in our direction and that will interact with outflow
boundaries and instability that will be present across our area late
this afternoon and evening. This will help fire off convection
across our westernmost counties in SE AL and the FL Panhandle around
and after sunset. As it continues eastward, a decrease in activity
is expected and a transition to stratiform rain followed by
dissipation is expected by early tomorrow morning.

There is currently a marginal risk for excessive rainfall in place
across the region today as scattered to widespread showers and
storms today have the potential to cause isolated flash flooding due
to elevated PWATs.

Expect daytime highs generally in the upper 80s to low 90s with
overnight lows generally in the mid 70s.

&&

.SHORT TERM...
(Sunday through Monday night)
Issued at 459 AM EDT Sat Jul 15 2023

Upper level troughing holds through Sunday, allowing for wet
weather to continue. Guidance suggest PWATs will remain moist and
tropical like, ranging from 1.50 to 3.0 inches. This means we
could get one more day of heavy rain with showers and
thunderstorms that develop, which falls in line with the WPC
Marginal Risk (level 1 of 4) for excessive rain. High temperatures
for Sunday are forecast to be in the upper 80s to low 90s, and
given the humidity it could be particularly gross. Uncertain as if
the current heat indicies will be realized, but we can generally
expect about 100-108 for our AL and GA counties. FL counties are
trending higher, and meet heat advisory criteria; however,
confidence is low as we'll have cloud cover and rain to play with.

By Monday, we start to transition to a warmer and perhaps slightly
drier period. Highs are forecast to be in the low to mid 90s,
while rain chances vary from 30 to 60%.

&&

.LONG TERM...
(Tuesday through Friday)
Issued at 459 AM EDT Sat Jul 15 2023

Ensembles and models show upper level ridging building in from the
west, which should lead to a warming and drying trend. High
temperatures are forecast to be substantially warmer, placing much
of the region in the mid to upper 90s each day. Moisture will be a
touch lower, but it's still looking like we could possibly meet
Heat Advisory criteria. Shower and thunderstorm chances may be
should be suppressed and mostly driven by the seabreeze. We could
see some gusty winds from storms if we're able to dry out enough.

&&

.AVIATION...
(12Z TAFS)
Issued at 638 AM EDT Sat Jul 15 2023

Showers and storms that are currently just offshore will move
onshore shortly and are expected to impact ECP and TLH within an
hour or two. They will then migrate north and impact our remaining
terminals throughout the day. Activity will be slow to wind down
after sunset as models are indicating the potential for convection
to persist a few hours into the overnight time period.

&&

.MARINE...
Issued at 459 AM EDT Sat Jul 15 2023

Daily chances of rain are expected due to the land breeze circulation.
Showers and thunderstorms will be most likely during the late
night hours lingering into the morning and early afternoon. Otherwise,
generally light to moderate west to southwest breezes are expected
with seas 2 feet or less for the most part.

&&

.FIRE WEATHER...
Issued at 459 AM EDT Sat Jul 15 2023

The current wet and moist pattern continues through the next few
days, there are no fire weather concerns.

&&

.HYDROLOGY...
Issued at 459 AM EDT Sat Jul 15 2023

Yesterday's rain caused for some rises on rivers in SE AL and the
W FL Panhandle yesterday. Bruce Creek near Redbay has moved into
minor flood stage and currently reads 18.56 feet, while Bear Creek
remains at action stage. The Choctawhatchee and Chipola rivers are
forecast to reach action stage over the next few days.

Outside of rivers, we've got another day or so of potentially
heavy rain. In the next 24-48 hours CAMs paint a decent, yet
varying bullseye of heavy rain generally along and south of I-10
and over the W FL Panhandle to the roughly Apalachee Bay.
Confidence is fairly low on where this will happen, thus kept the
Flood Watch the same. Guidance shows initial convection could be
seabreeze/outflow focused, with some form of an MCS coming
through later this evening. Rainfall amounts through Sunday range
from 0.5 to 2.0 inches over SE AL, 0.5 to 3.0 inches (highest
across the counties that border FL) across SW GA, and 0.75 to 4.0
inches, locally up to 6.5 inches, across the FL counties. The
higher amounts correlate with aforementioned FL area that was
highlighted. Flash flooding will certainly be possible if storms
stall, train, and/or target the areas that received rain
yesterday.

&&

.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   86  75  91  75 /  90  30  80  30
Panama City   88  79  90  78 /  80  30  70  30
Dothan        91  74  90  73 /  70  50  70  20
Albany        91  75  90  74 /  70  40  70  20
Valdosta      89  75  91  74 /  80  40  80  20
Cross City    89  76  89  76 /  80  40  70  40
Apalachicola  85  79  89  79 /  90  40  70  40

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch through this evening for FLZ007>017-026-027-108-112-
     114-115-127.

     High Rip Current Risk through this evening for FLZ114.

GA...Flood Watch through this evening for GAZ142-143-155>157.

AL...Flood Watch through this evening for ALZ065>069.

GM...None.
&&

NEAR TERM...Oliver
SHORT TERM...KR
LONG TERM....KR
AVIATION...Oliver
MARINE...KR
FIRE WEATHER...Oliver
HYDROLOGY...KR