Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Peachtree City Georgia
1020 am EDT Tuesday Jul 28 2015
forecast is on track and quite similar to yesterday. Convection
should begin to develop around midday with the best chances across
the northern half of the area. Otherwise...heat indices this
afternoon will be hot but still look to stay below advisory
Previous discussion... /issued 735 am EDT Tuesday Jul 28 2015/
Short term /today through Wednesday/...
medium range models continue to hold the region under the eastern
periphery of the upper ridge through Wednesday. Influence is not
quite enough to suppress all convective development and with slowly
but steadily increasing low/mid-level moisture we should see...
mainly diurnal...convection increasing somewhat today and Wednesday.
Still looks like coverage will remain scattered across the north and
isolated across central Georgia today and scattered across all of the
forecast area Wednesday. Instability is marginal to moderate at best
and no widespread severe thunderstorm development is expected at this
Afternoon highs will remain above seasonal normals through Wednesday
as well. Forecast heat index values are below heat advisory levels
today...but may approach or briefly exceed 105 across some of our
central Georgia counties Wednesday. Will need to watch later
forecast cycles for this potential.
Long term /Wednesday night through Monday/...
long range models continue to show good agreement with a weak
cold front pushing into north Georgia Wednesday night... then sagging
into central Georgia Thursday afternoon or evening. Both models show
the front meandering across central Georgia on Friday and Saturday...
then possibly slipping into south Georgia on Sunday... probably in
response to an upper low developing over the northeast Gulf that
causes a wave to develop along the surface front. Either way...
it appears a more active convective pattern remains on tap for
Friday and over the weekend as an upper trough settles over the
region... supporting scattered... to possibly numerous at times...
afternoon and evening showers and thunderstorms... with the greater
chances across central Georgia where the front remains a focus. Models
are showing the upper low drifting east and along the Georgia and SC
coasts on Monday... suggesting the greater rain chances should
shift east. Moderate instability and weak wind shear values
suggest most storms should remain below severe limits... with the
typical general thunderstorm threats of brief gusty winds...
frequent lightning and locally heavy rain expected.
Expect warm/humid conditions to persist across central Georgia each
day. However... behind the front... a northerly flow could bring
slightly cooler temperatures to much of north Georgia by Friday that
could persist over the weekend. 39
VFR conditions expected to predominate through the period. Local to
scattered MVFR or lower visibilities expected through 14z...however
only taf sites I expect any brief impacts are kahn/kpdk...kfty and
kmcn may see brief 6sm visibilities through 14z as well. Winds will
remain very light and variable in direction through the period...but
will most likely favor northwesterly at most locations. Afternoon/
evening convection is expected to be isolated enough not to include
in the tafs at this time except in the kahn vicinity.
//Atl confidence...12z update...
High on all elements...except medium on wind directions.
Preliminary point temps/pops...
Athens 93 73 93 73 / 30 30 40 30
Atlanta 92 75 93 76 / 30 20 30 30
Blairsville 88 68 88 70 / 30 30 40 30
Cartersville 93 72 92 72 / 30 20 30 20
Columbus 96 75 95 76 / 20 20 40 30
Gainesville 91 74 92 74 / 30 30 40 30
Macon 96 73 95 73 / 20 20 40 30
Rome 93 71 93 73 / 30 20 30 20
Peachtree City 93 72 93 70 / 30 20 30 30
Vidalia 96 75 96 75 / 20 20 40 20
Short term...rain shower