Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
418 am EDT Wednesday Jun 19 2013
Short term (today-friday)...
stagnant u/l pattern with a weak trough over the southeast U.S.
With an u/L Ridge over the Southern Plains. Main u/l westerly flow
will lift well north of the area across the Great Lakes and
northeast Thursday pinching off the weak trough over the southeast
U.S. U/l trough will remain over the southeast and continue to weaken
on Friday as the u/L Ridge over the Southern Plains builds through
the Ohio River valley to the middle Atlantic coast.
At the surface...high pressure over the western Atlantic with a ridge
axis across the central Florida Peninsula will remain over the
area today...with a weakening frontal boundary approaching North
Florida. Southwest boundary layer winds ahead of the front will be
across the forecast area today with scattered
showers/thunderstorms near the coast this morning. Sea breeze
boundary will push inland this afternoon with main area of
thunderstorms oriented north south from the northern interior to
southwest Florida. Surface ridge axis will gradually slide east of
the region on Thursday and Friday with increasing east to
southeast flow each day. This will decrease the onshore flow
component...with scattered afternoon thunderstorms developing over
the interior and likely pushing west back towards the coast during
the late afternoon and evening. As has been the case the last few
days due to the very weak overall flow...locally heavy rain is
likely each day due to the slow movement of storms.
Long term (friday night-tuesday)...
upper level ridging over the plains and MS valley at the start of
the period will build east and bridge across a weak middle level and
inverted surface trough just offshore the southeast U.S. Coast
during the upcoming weekend as surface high pressure from the
western Atlantic builds west across the southeastern states and
North Florida. As the surface ridge builds in a developing east
to southeast flow will help to increase moisture across the entire
forecast area. The increasing moisture combined with an east to
southeast steering flow will keep the West Coast sea breeze close
to the West Coast where the highest probability of precipitation and greatest areal coverage
of showers and storms will reside each day...during the afternoon
and early evening hours...before the convection shifts west into
the adjacent Gulf waters each night.
Temperatures will run a few degrees above normal through the period
with overnight lows in the lower 70s inland areas...and middle to
upper 70s along the coast...with daytime highs in the lower to middle
90s...except slightly cooler readings along the immediate coast due
to the sea breeze.
&&
Aviation...
scattered showers and isolated thunderstorms will produce brief
MVFR ceilings and visibilities at kpgd...kfmy...and krsw terminals
through 08z and at ktpa...kpie...and ksrq through 11z this
morning...otherwise VFR is expected. Other scattered showers and
storms developing along the West Coast sea breeze will be in the
vicinity of the terminals after 16z and thunderstorms in the vicinity has been included in
the taf package to cover this. South to southwest winds around 5
knots...will become southwest to west in the 8 to 10 knot range
after 15z...with gusts up to 25 knots possible in the vicinity of
thunderstorms. Light and variable winds will return to the terminal
sites after 20/02z tonight.
&&
Marine...
relatively benign conditions next several days on the waters with
winds less than 15 knots and seas 3 feet or less. Main hazard will
be isolated to scattered thunderstorms which may cause gusty winds
and locally rough seas.
&&
Fire weather...
no fire weather hazards through the period as abundant low level
moisture will keep afternoon relative humidity values below
critical levels.
&&
Preliminary point temps/pops...
tpa 91 78 91 77 / 30 20 50 20
fmy 92 75 92 75 / 40 20 50 20
gif 92 75 93 75 / 50 20 50 20
srq 89 77 90 74 / 30 20 30 20
bkv 90 71 92 70 / 30 20 50 20
spg 89 81 89 79 / 30 20 40 20
&&
Tbw watches/warnings/advisories...
Florida...none.
Gulf waters...none.
&&
$$
Short term/marine/fire weather...13/Oglesby
long term/aviation...57/McMichael
