Scientific Forecaster Discussion
fxus62 ktae 280723
Area forecast discussion
National Weather Service Tallahassee Florida
323 am EDT Tue Mar 28 2017
Near term [through today]...
The axis of an upper level trough has moved to our east this morning
and a strong upper ridge will be building in from the west through
the day. At the surface, high pressure centered off the southeast
U.S. Coast will ridge westward to the central Gulf. A cold front
entering northern Alabama/Georgia will pivot to become more east to west
oriented and begin to stall. However, with moist onshore flow and
above seasonal temperatures, an afternoon shower or thunderstorm
cannot be ruled out. The best chance (albeit slight) will be across
our interior western zones and far northern Georgia zones where just
a bit more moisture resides. Highs will be in the mid 80s inland and
upper 70s to around 80 along the coast.
Short term [tonight through thursday]...
The latest suite of nwp models are in good agreement in forecasting
a deep-layer ridge over the southeast tonight and Wednesday. We
expect fair weather during this time. The ridge will translate
eastward into the Atlantic on Thursday as q-g forcing and deep layer
moisture begin to increase across our region Thursday afternoon.
However, pops will be slight and mainly confined to the eastern and
western edges of our forecast area. Warm temperatures will be
prevalent through the period, with lows in the upper 50s to lower
60s, and highs in the mid to upper 80s (but highs only in the mid
70s at the beaches).
Long term [thursday night through tuesday]...
The large scale upper wind pattern will be split, with a fairly
active subtropical jet stream fluctuating from a position along the
Gulf Coast to south of the Gulf Coast. A series of upper level
troughs will dive into the Southern Plains, then translate east-
northeastward. These storm tracks will be farther south than what
we've observed over the past several days, which should result in
periods of much-needed rain for our region.
The first of these disturbances will move through our forecast area
Thursday night and Friday, resulting in likely rain chances for much
of our area. The GFS and CMC solutions continue to forecast enough
vertical wind shear and ascent to support storm organization,
including rotating updrafts, but The Tongue of greatest mlcape(less
than 1000 j/kg) lags the region of most favorable shear and ascent,
which could limit the overall threat. The European model (ecmwf) depicts a somewhat
more impressive system than 24 hours ago, but it still forecasts
rather unimpressive 0-1 km bulk shear and meager MLCAPE values (less
than 500 j/kg).
A deep-layer ridge will quickly develop in the wake of friday's cold
front passage, with fair weather for the weekend. Despite the front
passage, temperatures will remain warm with highs in the 80s and
lows in the 50s. The next southern stream trough to affect our
weather will be early next week.
Aviation [through 06z wednesday]...
Latest guidance still support areas of fog with IFR/LIFR conditions
developing mainly across southeast Alabama and the Florida by 09z and expanding
east to roughly aby southward to tlh by 12z. Went with brief period
of IFR vsby from 11-13z at vld. Shortly after sunrise, areas of fog
are expected to dissipate and VFR conditions will prevail through
the remainder of the period. Winds will be light from the
Light onshore winds and low seas will persist through Wednesday
evening. Winds and seas will gradually increase Thursday and Friday
as a cold front approaches from the west. Numerous thunderstorms are
likely ahead of this front Thursday night and Friday, followed by
fair weather and low winds and seas next weekend.
Red flag conditions are not expected for at least the next several
Dry conditions and river stages well below flood stage will continue
through Thursday. Quantitative precipitation forecast values have increased from 24 hours ago for
Friday, and we now expect much of the region to get 0.50 to 1 inch,
with locally higher amounts. Still, it appears unlikely that this
would result in rivers rising to flood stage.
Preliminary point temps/pops...
Tallahassee 86 59 88 58 88 / 0 0 0 0 10
Panama City 80 62 78 62 78 / 10 0 0 0 10
Dothan 84 61 86 59 85 / 20 0 0 0 10
Albany 85 62 87 60 87 / 10 0 10 0 20
Valdosta 87 60 88 59 88 / 0 0 0 10 30
Cross City 85 56 87 56 87 / 0 0 0 0 20
Apalachicola 80 61 77 61 77 / 0 0 0 0 10