Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 211339
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
939 AM EDT Sun Sep 21 2014
.Near Term [Through Today]...
The 7 am EDT regional surface analysis showed a 1017 mb high
pressure center near Dothan. Vapor imagery and upper air data
showed very dry, sinking air aloft over much of the Southeast. The
Precip Water values (a measure of moisture throughout the
troposphere) were 25-50% below climatology across much of our
forecast area. This dry air, coupled with the general sinking
motion of the troposphere, will prevent any rain from developing
today. In fact, clouds will be hard to come by. Highs will be
around 90 F, but the lower humidity will make it feel a little
more comfortable than what we`ve experienced over the past several
[Through 12Z Monday]...Unrestricted vis, unlimited cigs, and light
winds will prevail through late tonight. There is a slight chance
of patchy light fog around dawn Monday.
.Prev Discussion [252 AM EDT]...
.Short Term [Tonight Through Tuesday]...
With significantly drier air becoming well established across the
region today and tonight, expect mostly clear and quite cool
conditions over the entire CWA, save the immediate coast, with low
temps in the widespread lower to middle 60s, except near 70 at the
coast. On Monday, a strong Sfc high pressure ridge of reinforcing
cool and dry air will be building to our NW, with the next cold
front approaching the region from the same direction by the late
afternoon. Although it will be weakening, and not have much support
or moisture to work with, still believe PoPs will be in the 30%
range over much of our GA and AL counties, with 20% PoPs over the FL
Big Bend and Panhandle. Before any showers or storms arrive, high
temps will climb into the upper 80s N to the lower 90s to the S.
Although the reinforcing cooler and drier will attempt to push
southward into the region behind the front on Monday night and
Tuesday (and a few very cool lows in the upper 50s are possible over
SE AL), this front is expected to stall in the vicinity of our
coastal waters. Also, with the Sfc ridge expected to move east then
northeast from the Ohio Valley into New England, this may begin to
setup a rather moist easterly flow over the region which could set a
potentially wet pattern as we move from the middle to the end of the
week. At this time, however, deterministic PoPs and QPF will be
quite difficult to fcst, so stay tuned for updates from the National
Weather Service on this developing situation.
.Long Term [Tuesday Night Through Saturday]...
A strong surface high is likely to persist through much of the
period over the Northeast US, with an average 5-day position
somewhere in the vicinity of NY/PA per the GFS and ECMWF. With a
trend toward lower than normal surface pressures in the Gulf, this
will place the Gulf coast region in an extended period of easterly
low-level flow. Through mid-week, this should be accompanied by
cooler than normal temperatures and isolated showers. As next
weekend approaches (especially Friday and Saturday), rain chances
may begin to increase as tropical moisture arrives through slow,
steady northward advection over the course of the week.
With a brief return to a weaker surface pressure pattern, generally
light winds and low seas are expected across the coastal waters for
the rest of today through Monday. Thereafter, winds and seas will be
back on the increase behind the next cold front on Monday night and
Tuesday, which will likely help to usher in a fairly extended period
of at least cautionary level conditions as a strong ridge of high
pressure builds in well to our northeast. These conditions may
linger through much of the upcoming week.
Dry conditions are expected today, though relative humidity values
will remain above critical thresholds. Moisture will only gradually
increase over the next couple of days, meaning that hazardous fire
weather conditions are not expected.
Only light rainfall amounts are expected to fall across the region
through Monday, creating little or no impact on our area rivers and
streams. Thereafter, however, an extended period of moist easterly
flow may create a prolonged period of isentropic lift with the
potential for some heavier rainfall from mid to late next week.
.Preliminary Point Temps/PoPs...
Tallahassee 90 63 92 67 88 / 0 10 20 20 20
Panama City 88 71 89 70 87 / 0 10 20 10 10
Dothan 90 65 89 62 86 / 0 10 30 10 10
Albany 90 65 89 63 86 / 0 10 30 10 10
Valdosta 90 62 93 66 86 / 0 10 20 20 20
Cross City 89 64 92 67 87 / 0 10 20 20 30
Apalachicola 86 70 88 72 85 / 0 10 20 20 20