Scientific Forecaster Discussion
fxus62 kffc 141757
Area forecast discussion
National Weather Service Peachtree City Georgia
1257 PM EST Sat Dec 14 2019
Previous discussion... /issued 644 am EST Sat Dec 14 2019/
Previous discussion... /issued 358 am EST Sat Dec 14 2019/
Short term /today through Sunday/...
Broad upper trough over the southeast will move NE today leaving
zonal flow in its wake for Sunday. Looks like the last of the waves
that have moved through the state is exiting the area this morning.
This wave, along with the showers associated with it should be east
of the state just before daybreak. Most locations across the area
have see 1 to 2 inches of precip over the past 24 hours but a few
locations across east central Georgia have seen precipitation amounts in
the 2-4 1/2 inch range. Because we have been so dry over the past
few weeks, we are not seeing any flooding issues with the recent
rains. It appears this was just a very good soaking rain for the
state. Expecting things to clear out for the rest of the short term
with gusty northwest winds today.
High temps will get into the 50s to near 60 today with temps
increasing into the 60s to near 70s sun. Lows tonight will dip down
into the 30s.
Long term /Sunday night through Friday/...
The next weather maker will be approaching the area at the start
of the long-term forecast period. A surface low will develop over
the arklatex region by Monday morning as the upper trough ejects
into the plains. As the low lifts northeastward through the mid
Mississippi Valley and into the Ohio Valley Monday and into
Tuesday morning, the associated cold front will push eastward
toward the forecast area.
While showers will be possible in far north Georgia as early as
Monday morning, the most substantial increase in widespread rainfall
will be from Monday evening in northwest Georgia spreading
southeastward through Monday night and Tuesday as the cold front
sweeps across the area. The most favorable overlap of instability
and shear, and thus the higher risk for severe thunderstorms,
will be to our west in Mississippi/Alabama Monday. Surface cape
will begin to diminish to some extent ahead of the front Monday
night into Tuesday morning. With that being said, even a few
hundred j/kg of SBCAPE amid substantial shear would support some
risk for isolated severe thunderstorms Monday night into Tuesday
morning. Storm Prediction Center has thus included much of the western half of the
County Warning Area in a marginal risk outlook for severe thunderstorms during
this time. Additionally, there will also be the threat for locally
heavy rainfall as pws increase to near or above 1.5" ahead of the
The cold front will push fairly quickly through the County Warning Area through the
day Tuesday and clear the eastern counties by late in the day.
Strong cold air advection behind the front will bring significantly
cooler temperatures by Wednesday morning with freezing temperatures
making a return for much of the area. Below normal temperatures will
persist Wednesday, and subfreezing lows appear likely areawide by
Thursday morning. Dry conditions will persist through at least
Thursday, though model solutions begin to diverge thereafter.
MVFR clouds are beginning to break to the west of the forecast
area, trending towards breaking around the taf sites between
18-21z. Despite clouds breaking, guidance is still holding onto
abundant moisture below 5kft through the taf period, with
IFR/MVFR cigs likely returning tonight, but timing is uncertain.
If skies stay clear and winds light, dense fog may develop
instead, especially at southern sites. Gusty westerly winds will
lighten overnight becoming light and variable or calm from 03z-
15z, before becoming light and southerly. Shift at atl from south-southwest to
south-southeast expected around 21z.
//Atl confidence...18z update...
low to medium on lowered cigs/vsbys.
Medium to high on all other elements.
Preliminary point temps/pops...
Athens 56 38 60 42 / 20 5 0 5
Atlanta 53 40 58 48 / 10 5 0 5
Blairsville 48 34 56 43 / 30 5 5 20
Cartersville 53 38 60 46 / 10 10 5 10
Columbus 58 40 63 47 / 5 5 5 5
Gainesville 53 39 58 44 / 20 5 5 10
Macon 58 38 62 44 / 10 5 0 0
Rome 54 39 60 48 / 10 10 5 20
Peachtree City 56 39 61 47 / 10 5 0 5
Vidalia 61 41 64 45 / 30 0 0 0