Area Forecast Discussion
Issued by NWS Atlanta, GA
FXUS62 KFFC 301901
Area Forecast Discussion
National Weather Service Peachtree City GA
301 PM EDT THU JUN 30 2016
.SHORT TERM /Tonight through Friday Night/...
The latest surface analysis shows surface trough has shifted
southward ever so slightly but still generally from la Grange to
Athens. North of this feature...a very sharp gradient to the dry
air exists with dewpoints falling int the mid 50s over the far NW
corner of the state., Along and south of the boundary
though...ample moisture exists for storm development...mainly at
the low levels for North GA but deep layer moisture in place for
all of central GA.
Mixed layer CAPE in excess of 3000 J/KG over
portions of east GA at this hour and well over 2000 along and
south of the trough axis. This has already allowed for the
development of strong to isolated severe storms across the area.
The storms that form along and north the I 20 corridor will have
the benefit of dry air aloft and DCAPE values of 1200 J/KG to aid
the wind threat. In addition...hail will be prominent in these
storms with reports already coming out of Gwinnett county. For the
southern tier storms...with deeper moisture present...anticipate
additional flooding concerns down there due to slow movement of
We get a little upper level push for Friday which takes surface
trough axis southward. In addition...deep layer moisture will be
on the decrease area wide. Not enough of a dropoff for southern
sections to completely shut convection down but will be looking
more like 20 to 30 pops as opposed to the 60s of today.
.LONG TERM /Saturday through Thursday/...
The GFS continues to advertise a strong mid level trough to move
through the Tennessee valley through the afternoon on the 4th. It
will depend on timing as to whether we see washout conditions for
the 4th festivities or it is more scattered in nature ahead of the
trough. For now...kept it as mid range scattered but this
timeframe will need to be monitored closely for possible upgrade
to likely pops.
TSRA developing across southern sections of the forecast area and
look to affect mainly Macon and Columbus terminals this afternoon.
There is a line trying to develop as well just south of Athens so
will need to watch closely for possible inclusion of TEMPO there.
Otherwise...once TSRA dissipates tonight...MVFR to IFR cigs look
to develop but location is in question with one model showing ATL
and the other showing the south terminals. Favoring the southern
solution for now which puts IFR at MCN and CSG but keeps
conditions SCT for now at ATL.
//ATL CONFIDENCE...18Z UPDATE...
Medium on IFR potential.
High on remaining elements.
.PRELIMINARY POINT TEMPS/POPS...
Athens 70 94 70 96 / 30 10 10 30
Atlanta 72 92 73 94 / 20 5 5 30
Blairsville 63 87 65 87 / 20 5 5 30
Cartersville 65 93 68 93 / 10 5 5 30
Columbus 72 94 73 97 / 40 20 10 30
Gainesville 70 91 71 93 / 30 10 5 30
Macon 71 95 72 97 / 60 20 10 30
Rome 64 94 69 93 / 10 5 5 30
Peachtree City 68 93 68 95 / 20 10 5 30
Vidalia 73 92 74 95 / 60 30 20 40