Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Peachtree City Georgia
327 PM EDT Friday Jul 25 2014
Short term /tonight through Saturday night/...
upper trough is pushing east of he area and toward the coast...with
upper ridging spreading east toward the area. Flow aloft becomes
weaker and less defined through the short term and so with the
stalled surface front across central Georgia...the front will
continue to basically just wash out becoming more of a dewpoint/cape
gradient than anything. For this afternoon...convection is pretty
much limited to areas south of the front through we are seeing some
pinprick convection right along the frontal gradient. What weak
convection remains this evening will dissipate after 00z. For
tonight...lower dewpoints in north Georgia will allow temperatures
to drop down cooler than we have seen the past few days...but
central Georgia will still be a little more moist and muggy /and
thus could see some patchy fog around sunrise/.
With the washing out front and thicknesses increasing in the wake of
the exiting shortwave...temperatures tomorrow will climb to some of
the highest we have seen all Summer. As an interesting note...the
highest atl has seen in the past 21 days is 90 degrees and tomorrow
we are forecasting 91 for a high. The washing out front will still
be lingering in central Georgia tomorrow so have kept probability of precipitation generally
from Columbus to Macon to Milledgeville and areas south...and only
slight chance at that. Surface flow will begin to increase out of
the south Saturday night which will keep lows a few degrees warmer
than tonight...in advance of the next cold front approaching for the
Long term /Sunday through Friday/...
mainly only tweaks to the long term based on the latest guidance.
high pressure over the area begins loosing its foothold Sunday as
frontal system moves closer to the region. Moisture increases across
the state Sunday ahead of frontal system moving south out of the
northern plains/Great Lake states. This front is expected to move
into northwest Georgia by 12z Monday and slowly push south through the state. The
models are continuing to show this front pushing south into northern
Florida by 12z Tuesday. As this front moves across Georgia instabilities increase
with convective available potential energy expected around 2000 to 3000 j/kg and lifted indices ranging from -3
to -6. Shear values do not look that impressive but they do increase
a bit with the frontal passage. Currently Storm Prediction Center has the day 3 slight
risk area coming south out of Tennessee right to our northern border but I
would not be surprised to see that extended further south as we get
closer to the event. Once this front passes through...an upper level
deep long wave trough remains positioned over the area through much
of next week...keeping lower dew points and cooler temperatures in
place at least through the end of the work week. There will still be
some lingering moisture across southern portion of our County Warning Area with
moisture creeping back northward by next weekend. Will keep
diurnally driven slight to low chance probability of precipitation in mainly across central
Georgia through the forecast period. Beginning Tuesday...should see below
average temperatures with highs in the upper 70s north and low 80s
elsewhere...and lows in the 60s.
front south of metropolitan area will keep thunderstorms and rain out of northern tafs...
but continued tempo for csg/mcn. Otherwise...mainly scattered low VFR
clouds but broken for a while this afternoon at mcn/csg. Conditions
improve after 00z tonight with skies lifting north...but expect
MVFR fog to form ahn/mcn/csg. Kept visibility VFR for now at metropolitan tafs
but cannot rule out brief MVFR conditions at fty/ryy/pdk. Chance
thunderstorms and rain too low on Saturday to include for mcn/csg...so mainly few-
scattered low VFR cumulus. Winds generally west through the period around
//Atl confidence...18z update...
medium-high on no MVFR visibility Saturday morning.
High on all other elements.
Preliminary point temps/pops...
Athens 70 93 73 93 / 5 5 5 10
Atlanta 71 91 74 89 / 10 5 5 10
Blairsville 59 87 65 87 / 10 10 10 30
Cartersville 66 92 71 90 / 5 5 10 10
Columbus 73 94 75 92 / 20 20 5 20
Gainesville 69 91 74 91 / 5 5 5 10
Macon 71 93 74 92 / 30 20 5 20
Rome 66 92 71 90 / 5 5 10 10
Peachtree City 68 91 71 91 / 10 5 5 10
Vidalia 73 94 75 95 / 30 20 5 20