878 
FXUS62 KFFC 191927
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
327 PM EDT Mon Jun 19 2023



...Morning Area Forecast Discussion...

.SHORT TERM...
(This evening through Tuesday)
Issued at 325 PM EDT Mon Jun 19 2023

As expected, showers and thunderstorms have already fired across 
portions of north and central Georgia this afternoon. Most storms 
have been confined to mostly central Georgia thus far, but a few 
rumbles of thunder have been noted in some parts of north Georgia. 
Storms are mostly firing along a sudo-frontal/moisture boundary that 
is associated with the vertically stacked low slowly meandering to 
the southeast over portions of Kentucky and Tennessee. That low will 
continue to slowly work towards the CWA over the next 24-36 hours 
before parking itself right by us. Aloft, the upper level low has 
been cut off from the jet by anticyclonic rossby wave break over the 
northern Great Plains, which is stacking with the low to form a rex 
block over the eastern CONUS. As a result, rain chances will be back 
yet again tomorrow, as moisture continues to wrap itself around the 
low.

Instability parameters this afternoon have picked up, especially in 
portions of north Georgia where MLCAPE values above 1000 J/kg are 
noted, but this isn't aligned the best with the 
moisture/shear/forcing that is more available across portions of 
central Georgia. Severe chances are pretty low in north GA, but 
can't rule out a strong storm or two. In central Georgia, where the 
parameter space is a bit better despite the impact of this morning's 
MCS, we can expect a few strong storms, some severe, with the main 
impacts being damaging winds with any severe storms. Also can't rule 
out the possibility of some large hail, isolated flash flooding, and 
possibly a tornado or two through the evening hours.

Tomorrow has some inherent uncertainty thanks to the positioning of 
the upper low, which models tend to struggle with when it comes to 
cut-off type systems. It's likely that most everywhere will see some 
rain chances with the exceptions of west-central GA. However, how 
heavy that rain or thunderstorms may end up being will be dependent 
on the overall position of the low as well as some of the convective 
evolution this afternoon and evening. Best chances of seeing some 
heavier rain will be across northern and eastern GA, but that could 
certainly push a bit further west or south with a small jog of the 
low. As we continue to have repeated rounds of heavy rainfall, flash 
flooding will become more of a threat as the ground becomes 
saturated and creeks and streams less able to route away water, so 
please remain aware.

Lusk

&&

.LONG TERM...
(Wednesday morning through next Sunday)
Issued at 325 PM EDT Mon Jun 19 2023


As note in the previous forecasts the long term can be described as 
soggy as we see precip in the forecast through the entire long 
period. 

This wet pattern can be attributed to the closed upper low stalled 
over the SE that is part of a bigger omega block pattern and surface 
SSW flow. Both of these elements continue the support an exceedingly 
moist airmass. This in combination with lobes of energy rounding the 
base of the upper low will support continued shower and thunderstorm 
chances daily for much of the extended. Have maintained the usage of 
the word thunder given the average 1000 J/kg expected each 
afternoon. Currently, PWATs on the order of 1.5-1.75" are expected 
each day with model soundings showing a saturated profile with thin 
CAPE which will make for efficient rainmakers. Forecast rainfall 
totals continue to suggest widespread totals of 3.00-5.00" with 
locally higher amounts across the mountains of north GA. Given this 
forecast the Weather Prediction Center has some portion of the 
forecast area in a Slight Risk for Excessive Rainfall (Level 2 of 4) 
over at least the next three days. For now we have held off on a 
flood watch, but as local storm totals become realized there could 
be a need for a flood watch. For now the next seven days bear 
watching and the main focus is on small stream and river flooding. 

28

&&

.AVIATION...
(18Z TAFS)
Issued at 159 PM EDT Mon Jun 19 2023

Another challenging forecast for ATL and surrounding sites.
Currently MVFR at ATL and that should persist over the next few
hours. SHRA are affecting the site and could see a rumble of
thunder over the next few hours as well. Winds have gone to the
SSW, and should remain on the west side for the TAF period. Speeds
will be 7-12 kts today, going to 3-8 kts tonight through end of
period. Cigs are expected to SCT by 00Z, but will build back end
late tonight into early tomorrow morning. Some uncertainty on how
low these will be - current TAF shows MVFR, but won't rule out
brief period of IFR. TSRA possible again tomorrow afternoon.

//ATL Confidence...18Z Update...
Medium confidence cigs. High all others.

Lusk

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          80  68  81  65 / 100  60  90  90 
Atlanta         81  68  83  66 /  80  30  80  70 
Blairsville     76  62  75  60 /  90  60  90  70 
Cartersville    84  66  83  65 /  70  30  90  70 
Columbus        83  69  86  66 / 100  20  60  60 
Gainesville     79  68  79  65 / 100  50  90  90 
Macon           83  68  85  66 / 100  40  70  60 
Rome            84  68  83  66 /  70  20  90  70 
Peachtree City  83  66  85  64 /  80  30  80  70 
Vidalia         87  70  85  68 /  90  70  80  60 

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...Lusk
LONG TERM....28
AVIATION...Lusk