Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
920 am EST Thursday Dec 19 2013
..warmer temperatures on the way for the upcoming weekend...
14z water vapor and h4 rap analysis shows an upper level pattern
characterized by deep longwave troughing digging down the Pacific
coast and through the inter-mountain west...followed downstream by a
more zonal flow pattern over the central and eastern Continental U.S.. this
zonal flow pattern extends south to include the northern Gulf of
Mexico coast and Florida Peninsula. WV imagery shows a large swath
of very dry air in the middle/upper levels of the tropopause covering the
Florida Peninsula and the 18/12z ktbw sounding profile shows that
this dry air extends down into the near surface layers as well. The
ktbw sounding profile from this morning shows an impressive precipitable water value
of only around 0.27". This value is nearly 2 Standard deviations
below climatology for the middle of December. With all the dry air
over our heads...it is little wonder that we are experiencing
"crystal clear" skies this morning and near 100% of the possible
At the surface...our regions resides to the south of a 1028mb high
pressure ridge centered over GA/Carolinas. The gradient is not very
strong resulting in a weak easterly flow across the peninsula.
Temperatures were quite cool around sunrise with some near freezing
temperatures up toward Levy County...but already seeing a rapid recovery of
these temperatures with a couple hours of sun now in the books.
The rest of today and tonight...
a very dry column aloft and little in the way of moisture advection
or synoptic support for lift will keep our weather fair...dry and
seasonable. May see a few cumulus develop for the afternoon...but
with little moisture to work with and only a limited increase in low
level Atlantic moisture...our skies should remain mostly sunny
through the day. Temperatures will rise into the lower 70s
north...middle 70s central/I-4 corridor...and middle/upper 70s south for
the afternoon hours. Winds may go variable along the coast during
the afternoon as a feeble sea-breeze tries to develop...but the lack
of strong inland heating and some stronger flow just above the
surface...should keep any circulation confined to the beaches or
potentially just offshore.
Overnight...not anticipating any additional frost concerns for the
Nature Coast. Will be another cool night...but not nearly as cool as
Wednesday night into early Thursday morning. Coolest temperatures
down potentially to the lower 40s will be found across the northern
Nature Coast...with lower to middle 50s central and middle to upper
50s far south.
More generally fair weather with increasingly above normal
temperatures will continue into Friday and Saturday. Enjoy the rest
of your Thursday!
VFR conditions are expected to continue for the next 24 hours.
Surface high pressure situated over the southeast U.S. This morning
will move offshore this afternoon and tonight. Winds will remain
light out of the east northeast...then veering to the southeast by
this evening and into Friday.
easterly winds today will turn more to the southeast for Friday
and into the weekend. Wind speeds will increase some on Saturday
and then will likely reach cautionary or even advisory levels
Saturday night into Sunday as a front approaches the waters.
Speeds relax some Sunday into Monday and then turn northeasterly
behind the front with speeds increasing again once the front
moves through the waters. Hazardous conditions look to continue
through around mid-week.
Preliminary point temps/pops...
tpa 75 59 80 67 / 0 10 10 10
fmy 78 60 84 67 / 0 10 20 10
gif 76 57 82 64 / 0 10 10 10
srq 76 58 81 66 / 0 10 10 10
bkv 75 48 80 60 / 0 10 10 10
spg 73 62 78 67 / 0 10 10 10