Severe Thunderstorm Warning 177, NWS Tallahassee, FL

Area Forecast Discussion
National Weather Service Tallahassee FL
908 AM EDT SUN JUN 26 2016

.UPDATE...

Not much to add to the detailed discussion below. Convection got
an early start across SE GA and NE Fl along and ahead of the
frontal boundary. With daytime heating, we expect scattered to
numerous thunderstorms across our Tri-state region today. The
mean flow by this afternoon will be light from the north and
possibly becoming light and variable at times. Due to the slow
movement of storms in the rich moist environment, there is the
potential for some ponding of water in low lying and poor drainage
areas with the heavier downpours.

&&

.PREV DISCUSSION [628 AM EDT]...

.NEAR TERM [Through Today]...

A cut off upper level low can be seen in IR and WV satellite imagery
off the northeastern coastline as can a front trailing it
southwestward across the western Atlantic Ocean, westward across
southern Georgia, and then trailing northwestward across central
Alabama. Low level flow south of this front has been southwesterly
since Saturday, returning rich low level Gulf moisture to our area,
and steadily increasing PWAT values. With PWAT values forecast to
return to the 1.75-2" range, there will be plenty of moisture today
to feed thunderstorms. There will also be forcing for thunderstorms
between the front to our north and an afternoon seabreeze front in
north Florida. Finally, sufficient instability will be on tap thanks
to another abnormally warm day with highs once again in the upper
90s. All these thunderstorm ingredients together will mean much
higher chances for thunderstorms across the area than we've seen
this past week- there are 60 to 70% chances practically everywhere
in our CWA this afternoon. With strong instability on tap, some of
the storms today may produce downbursts of damaging winds and some
small hail.

The heat and humidity today will also make heat indices a concern.
Maximum apparent temperatures are expected to reach 100-105F across
the area again this afternoon, so make sure to stay hydrated, wear
sunscreen, and don't leave kids or pets inside your car.

.SHORT TERM [Tonight Through Tuesday]...

A broad upper level ridge will remain in place over the
southeastern CONUS, along with decent moisture (PWAT values near
2") on Sunday evening. Although there will be a lack of upper
level forcing, a stationary front will be located over southern
Georgia through the eastern Big Bend region, which could maintain
scattered showers/thunderstorms in these areas through the evening.
Chances for showers and storms will decrease slightly on Monday,
as the front dissipates and drier air pushes into our area from
the northeast. Enough moisture will remain (especially over our
Florida counties) to maintain low chances of showers and storms,
mainly in the afternoon and early evening due to sea breeze
forcing. Chances for scattered showers and thunderstorms will
improve Tuesday afternoon, as PWAT values increase to near 2"
over our area with moist southwesterly flow. Seasonably hot and
humid conditions will persist, with highs in the low-mid 90s
inland (upper 80s along the Gulf Coast), and lows/dewpoints in the
70s across our area.

.LONG TERM [Tuesday Night Through Sunday]...

The pattern across the southeastern CONUS will shift at the
beginning of this period, with an upper level ridge replaced by a
trough digging southward into the northeastern Gulf. This will
lead to an enhanced chance of showers and thunderstorms on
Wednesday and Thursday across our region. A few strong to severe
thunderstorms cannot be ruled out each of these days, as 0-6 km
bulk shear should increase to at least 20 kts over parts of our
area, along with CAPE ranging from 1000-2000 J/kg. This
instability/shear combination would be somewhat sufficient for
organized multicellular thunderstorm development, and a quasi-
stationary front setting up over southern AL and GA will provide
forcing for convective initiation along with the sea breeze each
afternoon/evening.

Precipitation chances look slightly lower on Friday and during the
weekend, as drier air moves into our area and the aforementioned
front over AL/GA may retreat farther north. Scattered showers and
thunderstorms still are possible each afternoon and early evening,
especially across northern FL with sea breeze forcing. Highs will
range from the upper 80s to lower 90s throughout this period, with
lows generally in the low-mid 70s.

.AVIATION [Through 12Z Monday]...

Afternoon thunderstorm coverage is expected to be more widespread
today than the past week. Peak activity period is expected to be
between 18-02Z, with storms starting earlier in Florida and
lingering later into the evening in southwest Georgia. During
storms, visibilities and ceilings may drop, but will likely stay in
the MVFR-VFR range. VFR conditions are expected to prevail through
the period outside of thunderstorms.

.MARINE...

Light winds will persist through early next week, increasing
slightly to 10-15 knots from Tuesday through the remainder of the
week. Seas are expected to remain around 2 feet or less throughout
the next several days.

.FIRE WEATHER...

Daytime dispersions will be low today due to weak transport winds.
Relative humidity values will remain above 40% for the next week.

.HYDROLOGY...

River, urban, or rural flooding will not be a concern over the
next several days.

&&

.PRELIMINARY POINT TEMPS/POPS...

Tallahassee   98  74  94  75  93 /  60  30  30  20  50
Panama City   89  77  87  77  87 /  30  10  20  10  30
Dothan        95  73  93  74  92 /  60  30  30  20  60
Albany        98  74  94  74  93 /  60  50  20  20  60
Valdosta      96  72  92  73  93 /  70  40  30  20  50
Cross City    95  73  92  74  91 /  60  30  40  20  40
Apalachicola  92  77  88  77  88 /  20  10  20  10  30

&&

.TAE WATCHES/WARNINGS/ADVISORIES...

FL...None.
GA...None.
AL...None.
GM...None.

&&

UPDATE...Barry
NEAR TERM...Moore
SHORT TERM...Lahr
LONG TERM...Lahr
AVIATION...Moore
MARINE...Lahr
FIRE WEATHER...Moore
HYDROLOGY...Harrigan