Welcome to the New NWS' Forecast!
Most changes are behind the scenes, but click here for differences you might notice.

Area Forecast Discussion (AFD)

Issued by Peachtree City, GA (FFC)

FXUS62 KFFC 281134

Area Forecast Discussion
National Weather Service Peachtree City GA
734 AM EDT Fri Jul 28 2017

.PREV DISCUSSION... /Issued 325 AM EDT Fri Jul 28 2017/ 

SHORT TERM /Today through Saturday/...
Early morning radar imagery reveals just a few nuisance showers 
between ATL and MCN metros. Have not seen any lightning with this 
activity the last few hours. Farther upstream...a larger complex of 
showers and thunderstorms...associated with a weak 500mb vort max 
was located across south central TN and northwest AL moving 
southeast. This activity will begin to push into NW Ga in the next 
few hours as the shortwave maintains its intensity. Could also see 
some patchy areas of fog towards sunrise as dewpoint depressions 
near zero.

Aforementioned vort max will be the main source of shower and 
convective development this morning and into the afternoon. Deepest 
moisture will reside across north Georgia so highest coverage 
will generally be in this area. Model analysis of the synoptic 
pattern reveals a robust shortwave across the Great Lakes...and 
progged to move southeast towards DELMARVA through 00z sunday. 
Southward movement of this disturbance will allow a sfc wave 
initially along a cold front draped across the OH Valley to 
become more organized as it begins to move eastward through WV and
eventually VA and off the Atlantic Coast. This movement will 
allow the cold front to push through the CWA over the next 36 
hours...a rather uncommon treat this time of year. 

Although the aforementioned shortwave will initially produce 
showers and storms over the area...focus will begin to shift 
towards the front this afternoon and evening. With all this in 
mind...southward building of mid/upper level cyclonic flow...along
with strengthening lower level westerly winds associated with the
sfc low to the north will easily allow for deeper layer shear to 
approach the lower-mid 20s (kts). This combined with plentiful 
moisture and instability should allow for the development of a 
healthy mix of both loosely organized line segments and pulse 
thunderstorms. Could see some severe activity with the primary 
threat of very heavy rainfall and damaging winds/downbursts. Would
not be surprised to see SPC upgrade the area back to marginal or 
even slight risk.

Activity could persist into Friday night with an overall weakening 
trend. Front should be just south of ATL-AHN metro areas by 12z 
Saturday. Some absolutely beautiful weather is store behind this 
front (for July) as drier air moves into north Georgia. 
Unfortunately central Ga will still see one more day of mainly 
diurnally driven storms along the front/ perhaps a few strong/. 
Mixing ratios behind the front are around 10g/kg with PWs under 1 
inch-this is exciting!


LONG TERM /Saturday Night through Thursday/...
Models continue in good agreement through the long term. The cold 
front and associated short wave will continue to exit Saturday night 
pushing the rest of the precip out of the CWA. It should dry over 
the CWA Sunday through Tuesday as Canadian high pressure builds over 
the Ohio Valley. Then as the next short wave drops into the mid 
Mississippi Valley, the eastern trough broadens and the moisture 
patterns become messy so have gone with climo for pops. Temps will 
be at or just below normal through the long term. 



12Z Update...
Some patchy areas of fog have developed this morning. Expect this
to continue for perhaps the next hour or so. An area of showers
and probably some thunder will move into northern TAF sites later
this morning. From then on convection will also be possible
through the evening...though coverage is becoming more uncertain.
MVFR/IFR cigs should develop after midnight or so Friday night as
a cold front moves through. Could again see some patchy fog by 
daybreak Saturday. Convection on Saturday should be confined to 
CSG and MCN. West winds will become more northwest behind the cold
front Saturday morning and begin to gust between 15-20kts. 

//ATL Confidence...12Z Update...
Medium on convective coverage this afternoon.
High on all other elements.



Athens          89  72  88  67 /  60  50  20   5 
Atlanta         87  72  86  68 /  70  50  20   0 
Blairsville     79  66  81  59 /  70  50  20   5 
Cartersville    84  71  85  65 /  70  50  20   0 
Columbus        93  75  89  70 /  50  50  40   5 
Gainesville     83  71  85  66 /  70  50  20   0 
Macon           92  74  90  69 /  50  50  40   5 
Rome            84  71  86  65 /  70  50  10   0 
Peachtree City  87  72  87  67 /  60  50  20   0 
Vidalia         93  75  88  71 /  50  50  60  20 




SHORT TERM...Kovacik