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fxus62 ktae 181731 
afdtae

Area forecast discussion
National Weather Service Tallahassee Florida
131 PM EDT Wed Sep 18 2019

Aviation...
[through 18z thursday]

Scattered tstorms across the eastern portion of the region are
possible in the afternoon and in to the early evening, bringing
possible MVFR conditions. Winds will shift to easterly behind a
front with a chance of 15-20kt gusts along the frontal boundary.
VFR conditions should prevail throughout the period across the
region, however there is a slight chance of low level clouds in
the overnight hours for the westernmost terminals as the front
passes. This was omitted because of low confidence.



&&

Previous discussion [1023 am edt]...

Near term [through today]...

Parts of the area will see from relief from the heat as a backdoor
cold front sneaks in from the east this afternoon. This is in
response to a developing ridge through the northeast states along
with surface high pressure building south. Thunderstorms should
start to develop after 18z generally from the east but hires
guidance is showing scattered development across much of the central
Florida Panhandle and SW Georgia by 19-20z, maybe developing off a weak
shortwave ahead of the front. With the actual front, a line of
showers and storms should move NE to SW after 23-00z, which looks to
also be enhanced by the East Coast sea breeze. With it getting here
after peak heating, the line may not hold together as it reaches
Tallahassee. Highs will still be able to reach the lower 90s east of
Tallahassee but in the upper 90s, close to 98-99 west of here,
especially in southeast Alabama. There will be a gradient which will depend on
how far the front makes it and where thunderstorms develop.

The threat of strong storms isn't too high but it's interesting to
note that dcape in the GFS gets to around 1300 j/kg around 21z,
thanks to a pronounced inverted v sounding below 700mb. There's also
a little wind shear, definitely some directional shear, along with
about 20 knots of 0-6km shear. Although not impressive, in the
Summer, combined with over 1000 j/kg of cape and near 1000 j/kg of
dcape, it could bring a strong storm or two. Not sure if there will
be strong enough lift or deep enough moisture but it's certainly
something to watch.



Short term [tonight through friday]...

In the upper levels a ridge will be over the southeast. At the
surface high pressure centered over New England will move south and
become centered over the mid-Atlantic. Locally weak high pressure
will be in place tonight and tomorrow with strong high pressure
tomorrow night and Friday. Low level flow will be easterly. This
evening pops will be 30 to 50 percent in the Florida Panhandle and
Big Bend, perhaps from a weak surface boundary or possibly an
enhanced (by easterly flow) Atlantic sea breeze. Otherwise pops will
be very low. Highs will be in the mid to upper 80s. Lows will be in
the 60s and lower 70s.



Long term [friday night through wednesday]...

In the upper levels a ridge will be over the southeast. At the
surface weak high pressure will be over the region with easterly
flow. Pops will be near zero. Highs will be in the lower to mid 90s.
Lows will be in the 60s.



Marine...

Westerly winds will become strong and easterly tonight. Advisory
level winds are likely beginning tomorrow night. Strong easterly
winds will continue through Saturday night.



Fire weather...

Isolated to scattered thunderstorms will impact most of the area
today, especially areas around Tallahassee and east. Winds will
increase tonight into Thursday as a front moves through with
easterly transport winds around 20-25mph possible. With relatively
high mixing heights and winds, dispersion values will be above 75
across the area. Relative humidity values will be well above minimum thresholds so
red flag criteria is not expected. Fog is not forecast through
Thursday.



Hydrology...

River levels are low. Rain is possible today and tonight then dry
weather will return. Less than one inch of rainfall is forecast over
the next seven days.



Spotter information statement...

Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting US @nwstallahassee.

&&

Preliminary point temps/pops...

Tallahassee 70 89 66 90 67 / 30 0 0 0 0
Panama City 73 89 69 88 70 / 40 20 0 0 10
Dothan 70 86 63 87 64 / 20 0 0 0 0
Albany 68 84 63 86 65 / 10 0 0 0 0
Valdosta 67 86 64 87 65 / 10 0 0 0 0
Cross City 70 88 68 89 68 / 30 0 0 10 0
Apalachicola 73 86 70 86 71 / 50 20 10 10 10

&&

Tae watches/warnings/advisories...
Florida...none.
Georgia...none.
Alabama...none.
GM...none.
&&

$$

Near term...line
short term...mcd

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