Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL
FXUS62 KTBW 231858
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
258 PM EDT Sun Apr 23 2017
.SHORT TERM (Rest of today-Monday)...
An upper low near the south-central Mississippi Valley this
afternoon tracks southeast to the GA/SC border. A short
wave trough over southern FL lifts northeastward and is
absorbed into troughing from the upper low. At the surface a
low in northern GA trails a cold front south across the FL
panhandle then southwestward over the Gulf of Mexico. The
surface low move to the Carolina coastal waters by late Mon
afternoon with the front sweeping into the east Gulf tonight
then across the state Mon. In response to the front and the
upper level short wave trough...a surface trough over the
straits from western cuba to the northern Bahamas lifts
northeast and merges in the Carolina surface low.
The deepest moisture...model PWAT values at 2 inches or more...
which resulted in some record rainfall in the south has shifted
away. However enough residual moisture...PWAT in the 1.5 to 2 inch
range...and instability remain which along with sea breeze
convergence and limited day time heating to support a chance of
showers and a slight chance of thunderstorms through the rest of the
afternoon. There should be a break in rainfall from late afternoon
or early evening through the later night hours. But expect some
cloudiness along with patchy late night fog...especially in areas
that received rain. Slightly deeper moisture returns with the front
but limited with PWAT in the 1 to 1.5 inch range...enough for
scattered showers or a few thunderstorms. The front and associated
weather begin to impact...the Nature Coast in the pre-dawn
hours...the Tampa Bay area around sunrise...Southwest Florida around
mid-afternoon...then exits by late afternoon. Winds will pick
noticeable with the front but will mainly be of concern for
.MID TERM/LONG TERM (Monday Night-Sunday)...
Monday night into Wednesday the mid/upper level shortwave trough
will continue to move up along the eastern seaboard away from the
region followed by ridging gradually build over Florida as a
deepening trough sets up over the western half of the CONUS late in
the week through the weekend. At the surface weak high pressure will
be over the area for Monday night through Thursday, then late in the
week into the weekend a stronger high pressure will build in from
well out in the Atlantic Ocean. For Monday night into Tuesday night
a low level west to northwest flow will be in place bringing some
cooler and drier air into the region under fair skies. During
Wednesday and Thursday the flow will shift to south to southwest
with limited moisture continuing across the region so expecting
mostly clear to partly cloudy skies with rain chances less than 10
percent. For Friday through Sunday the low level flow will shift to
southeasterly with moisture gradually increasing leading to some
additional clouds. There will be a slim chance, less than 20 percent,
for a light shower/sprinkle Friday, then over the weekend some more
moisture could move into the region leading to a few showers, but
will keep rain chances at around 20 percent at this time as moisture
does not look that deep. Temperatures will be close to normal for
Monday night and Tuesday then as the ridging builds aloft we`ll see
a gradually warm up a couple of degrees each day reaching the mid
80s coast to the lower 90s inland for Friday through Sunday.
23/18Z-24/18Z. BKN mid deck spreads north this afternoon as all
terminals swing to westerly winds. ISOLD TSRA expected around 20Z-
24Z. Generally VFR over night with SCT-BKN clouds...possible MVFR
CIGS TPA and PIE...and LAL and PGD could see some limited late night
BR. Front arrives at the northern terminals around sunrise with
VCSH...AFT 18Z at southern terminals. Westerly winds begin to pick
up toward the end of the period.
A trough of low pressure moves beyond the waters tonight as a cold
front slides into the east Gulf...then across the state Mon. High
pressure builds back in Tue and continues for most of the week...
with an axis meandering around central/north FL.
The main concerns may be a few thunderstorms this afternoon but
expect these to mainly be onshore. The front tonight-Mon will come
through with showers although can not rule out a thunderstorm or
two. Winds increase in the wake of the front...up into the exercise
caution range Mon afternoon-night.
Recent heavy rainfall...especially in the south...along with more
limited rain as a cold front moves through late tonight and during
Mon will provide enough moisture to preclude any low RH concerns for
the next few days.
.Preliminary Point Temps/PoPs...
TPA 70 77 65 80 / 20 10 0 0
FMY 69 80 65 82 / 10 20 0 0
GIF 67 79 60 83 / 30 10 0 0
SRQ 70 76 64 80 / 30 20 0 0
BKV 66 76 56 81 / 30 20 0 0
SPG 70 76 65 79 / 20 10 0 0
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...09/Rude
MID TERM/LONG TERM/DECISION SUPPORT...69/Close