Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
715 PM EST Thursday Jan 29 2015
Update (rest of tonight and friday)...
00z water vapor and h4 rap analysis show another upper level trough
amplifying into the eastern third of the nation. Main shortwave
energy leading this amplification is currently dropping into the Tennessee
Valley from the northwest...and will continue east and southeast
overnight before exiting the Atlantic Seaboard during the day
Friday. This energy will mainly pass by to our north during the next
12-18 hours with negligible height changes across much of the
Currently at the surface we find an area of low pressure associated
with the digging energy located over the eastern Great Lakes on its
way eastward toward New England. A cold front is analyzed trailing
back to the south across the Ohio Valley/ Tennessee Valley...and eventually
reaching down toward the MS Delta Region of the northern Gulf Coast.
This front will slowly approach throughout the overnight and then
cross the forecast area during the daylight hours of Friday. The
front should be arriving toward Levy County shortly after
sunrise...the Tampa area for the early afternoon and points south
later in the afternoon/early evening.
The good news is that with the main synoptic height falls/qg forcing
passing to our north...and not much column moisture to work
with...we are not anticipating any rainfall to accompany this
frontal passage. Probability looking at just a band of scattered-broken clouds and
and a slight increase in winds from the northwest to mark the
Before that happens...a quiet...cool...and dry overnight period is
to be expected for all. Clear skies will give way to a few-scattered high
level cirrus during the second half of the night...and Friday
morning. Low temperatures by sunrise should range from the lower to
middle 40s north of the I-4 corridor to the middle 40s to lower 50s
elsewhere. High temperatures Friday reaching the middle/upper 60s
north...and lower 70s south.
VFR conditions generally expected for the duration of the taf
period. Outside chance of a brief period of MVFR visible toward dawn for
klal/kpgd...however confidence in this occurrence is low enough to
leave out mention in current tafs. Cold front will cross the
terminals during the afternoon hours of Friday. Expect a band of VFR
level scattered-broken clouds to accompany the front...but not much else.
Winds will pick up somewhat between 10-14 knots after the frontal
passage for the northern terminals. Southern terminals will not see
the frontal passage until late in the day.
high pressure currently in control of the forecast waters will begin
to drop south overnight. A cold front will move across the waters
during the daylight hours of Friday with winds becoming north and
approaching cautionary levels to the north of Tampa Bay for the
afternoon hours. Winds shift northeast Friday night for all areas
behind the front with winds potential approaching advisory levels.
High pressure will build north of the region for the upcoming
weekend. The high position to the north suggest the potential for
elevated easterly flow each overnight and early morning...with winds
and seas relaxing during each afternoon.
Preliminary point temps/pops...
tpa 53 69 46 70 / 0 10 0 0
fmy 52 73 51 74 / 0 0 0 0
gif 50 71 46 70 / 0 10 0 0
srq 51 70 47 71 / 0 10 0 0
bkv 42 70 39 69 / 0 10 0 0
spg 56 69 51 68 / 0 10 0 0