Scientific Forecaster Discussion
fxus62 ktae 141905
Area forecast discussion
National Weather Service Tallahassee Florida
305 PM EDT Mon Oct 14 2019
Near term [through tonight]...
With a ridge aloft over the Gulf of Mexico, upper level flow will
remain out of the west overnight tonight. Satellite and water vapor
imagery shows that increased moisture will filter into the region
overnight with this flow. This increase in moisture, in conjunction
with the frontal boundary which is draped across the western Florida
Panhandle and southern Georgia/al, will increase pops for the northern
portion of the County Warning Area tonight. Lows will only drop into the upper 60's
and low 70's tonight due to the increase in cloud cover.
Short term [tuesday through Wednesday night]...
On Tuesday, a departing upper low over the northeast states will
have a cold front strung out south of it, across the western
Atlantic and then laid west to east across southern MS, Alabama and Georgia.
An elongated ridge of high pressure aloft will be stationed over
the Gulf with near zonal flow over the local area. The stationary
front should have showers ongoing at the start of Tuesday. Winds
at the surface will start shifting to the south as a weak low level jet
ramps up in response to upper shortwaves along the frontal
boundary. A pretty distinct boundary will set up at the surface
anywhere from around Tallahassee (gfs) to our northern border
(nam) especially between 15-21z. Instability increases as the
profile saturates with precipitable water values around 2.2 inches and SBCAPE
around 1500 j/kg. Also, with the low level jet nearby, 0-6km shear will be
around 40 knots with 15-20 knots of 0-1km shear. Given the wind
profile, a few rotating updrafts are possible near and just south
of the frontal boundary. The lift is messy at best so thinking
tomorrow will be clusters of showers with a few more organized
thunderstorms toward early afternoon that could produce gusty
winds. A few rotating showers may have to be monitored as well and
this was mentioned in spc's discussion when they placed US in a
marginal risk for Tuesday.
By 00z, the boundary pushes north with south-southeast flow
areawide. But with the continued shortwaves aloft, plenty of
moisture around and some shear, showers and a few thunderstorms will
be ongoing Tue night. The front should move through Wed morning
through Wed evening, clearing out the rain and bringing much drier
air in its wake. A few Post frontal showers are possible as the
drier air moves in.
Highs Tuesday will be cooler to the north under the rain, in the mid
70s to the upper 80s along the coast. Similar conditions expected
on Wednesday ahead of the front. Lows Tue night will be warm, in
the lower 70s, and drop to the lower 50s north and lower 60s south
on Wed night.
Long term [thursday through monday]...
The story for Thursday is the much cooler temps with highs dropping
into the 70s and maybe a deg or two cooler for Friday. The last time
Tallahassee had a high temp in the 70s was April 24 2019 when the
high hit 79 degrees. Lows on Thu night may hit the 40s in southeast Alabama and
parts of SW Georgia with the rest of the area in the mid 50s. Temps start
to rise for the weekend and be back in the upper 80s by Monday.
An upper low will be moving northward in the Gulf with a surface low
forming along the coast on Saturday. This will bring additional rain
to the area and have upped the model blends to scattered pops for
Sat- Mon. Rain will hang around until another front clears it out
[through 18z tuesday]
VFR conditions are expected to prevail for all terminals throughout
the afternoon and evening, but a stray shower cannot be ruled out.
By tomorrow morning, low ceilings will settle in from west to east
and slowly drift north as the morning continues. This will reduce
dhn, aby, and ecp to MVFR. Showers will be more widespread in
the morning, especially for dhn and aby. Consequently, dhn and aby
will be left under MVFR conditions for the rest of the taf period
with rain and patchy low ceilings expected to remain.
Southerly winds around 10 to 15 knots shift slightly to the west
on Tuesday and will continue there until a frontal passage
Wednesday night. Scattered showers and thunderstorms are possible
across the waters Tuesday through Wednesday night. Behind the
front, winds are more northerly. Showers and thunderstorms are
possible again for the weekend.
Active weather pattern with elevated rain chances the next 2 days
will keep fire weather concerns low through Wednesday. A
stationary front will be stationed across southeast Alabama and southern
Georgia on Tuesday leading to a chance of showers and
thunderstorms along and south of the front with low dispersions
expected north of the front. Front pushes through the area
Wednesday afternoon with increased dispersions expected in the
afternoon hours. Widespread dense fog is not expected but
increased moisture content over the region will lead to patchy fog
the next few days.
An end to the dry weather will be coming soon with light showers
ongoing through Tuesday. Heavier rain will impact mostly areas
north of Tallahassee Tue/Wed with around 1-2 inches forecast and
localized heavy rain possible. Along the coast, around half an
inch to an inch is possible. Additional prolonged rainfall looks
likely from Saturday through Wednesday but will be dependent on
the track of an upper low in the Gulf. Flooding will not be a
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 72 85 72 85 57 / 10 70 60 60 10
Panama City 74 85 75 85 59 / 10 60 60 50 10
Dothan 68 80 69 79 51 / 40 80 80 50 0
Albany 69 79 70 80 52 / 50 80 80 50 0
Valdosta 71 83 72 82 55 / 10 70 60 60 0
Cross City 71 88 72 85 63 / 0 30 60 60 20
Apalachicola 73 84 75 83 62 / 0 50 60 60 10