765 
FXUS62 KFFC 010543 AAA
AFDFFC

Area Forecast Discussion...UPDATED
National Weather Service Peachtree City GA
143 AM EDT Sat Apr 1 2023



...New 06Z Aviation Discussion...

.UPDATE...
Issued at 1037 PM EDT Fri Mar 31 2023

No major changes to the short term at this time. Slightly 
adjusted timing as event approaches, with current thinking FROPA 
approaching NW GA by 4-6am pushing through the ATL metro and into 
central Georgia on Saturday morning by 6am-10am. Warm night ahead 
with low temps in the low to mid 60s area-wide. 


&&

.SHORT TERM...
(This evening through Saturday)
Issued at 306 PM EDT Fri Mar 31 2023

Active weather expected in the short term forecast as a very 
potent system moves into the midwest and rapidly deepens, driving 
a cold front into the CWA later tonight into the morning and 
afternoon tomorrow. Currently, high based showers have formed over
north GA as warm gulf air is isentropically lifted well ahead of 
the system out west. These will likely continue on and off through
the evening and into the overnight hours. Winds have also picked 
up. Current conditions show 10-15 mph with some higher gusts 
across the CWA, which will continue into the overnight hours.

Things have a chance to get a little spicier going into the 
overnight and early morning hours. Ongoing supercells and QLCS 
type convection well to the west is expected to begin 
consolidating into a more linear system ahead of a cold front that
will provide a continued source of lift as it progresses to the 
east. Current thinking is that this line will arrive into portions
of northwestern GA by 06-08Z (2AM-4AM EDT), move through the 
metro between 11Z-15Z (7AM-11AM), and then progress into portions 
of central GA through the afternoon. Clearing is expected behind 
the line.

Beginning with tonight - best upper level forcing will be well 
removed from the system as it pushes through the area, so 
convection will likely be reliant on cold front for forcing, at 
least during the overnight. This should prevent any cells from 
forming out ahead of the line, especially given the lack of any 
day time heating or other obvious forcing mechanisms. Hires 
guidance continues to consistently show some instability just 
ahead of the front. Ensemble averages for SBCAPE are in the 
300-500 J/kg range, and looking at individual MLCAPE values gives 
a similar result. Shear is the concerning factor, and the variable
which could give some life to a few storms as they push through. 
0-1 km SRH values are 200+ m2/s2 across the guidance, which is 
plenty of streamwise vorticity for updrafts to work with. 
Convergence along the front is pretty weak given SSW to SW winds 
out ahead of it, but any local storm scale effects that work those
winds a bit further east could certainly make for a robust 
updraft, even if short lived. Put all this together, and you get a
slight risk for NW GA, moving to a marginal risk as it pushes 
through the metro. Wind will be the primary threat, but certainly 
can't rule out a tornado or two within this parameter space, 
something we've seen happen far too often this year already.

For tomorrow afternoon, some morning to afternoon heating will 
allow for some reintensification of storms as they push through, 
as well as the potential for some reformation dependent on morning
coverage that holds together. The parameter space looks very 
similar to what was described above, with a bit less SRH (100+) 
and a bit more instability to compensate (1000 J/kg+). CAMs have 
been pretty aggressive with some UH tracks in far SE portions of 
the CWA, so will definitely need to keep an eye on how things 
evolve tonight. Day 2 has been upgraded to Slight in these areas 
as a result.

The final story is the winds on the backside of the system, which
are expected to pick up tomorrow afternoon. A Wind Advisory has 
been issued Saturday from 8 AM to 11 PM for areas along and north 
of I-20 where winds should be strongest. While sustained winds 
will be generally 10-20 mph, we could see gusts as high as 40 mph.
At elevations above 3000 ft, winds gusts could be even stronger. 

Lusk


&&

.LONG TERM...
(Sunday morning through next Thursday)
Issued at 306 PM EDT Fri Mar 31 2023

The extended forecast remains mostly on track, with only minor 
adjustments made based on the latest guidance. The previous 
discussion follows...

King

Previous LONG TERM
(Saturday night through Thursday)
Issued at 429 AM EDT Fri Mar 31 2023

A cold front will bring additional chances for showers and 
thunderstorms for the late week into the weekend.

High pressure will be in place across the CWA for the first part 
of next week. A cold front will begin to move out of the central 
US into the Mississippi River Valley by late Tuesday into 
Wednesday. The boundary should cross the Mississippi River on 
Wednesday and then move through the CWA on Thursday. By late 
Thursday into early Friday, the front should begin to become 
parallel with the mid level flow...stalling somewhere across 
central or southern GA and increasing the potential for some 
locally heavy rainfall. 

Models are also still progging the chance for some showers and 
thunderstorms overnight Sunday into Monday as a strong shortwave 
moves across. Thickness values do indicate that there is some 
potential for an organized area of thunderstorms/MCS(?).

NListemaa


&&

.AVIATION...
(06Z TAFS)
Issued at 125 AM EDT Sat Apr 1 2023

MVFR ceilings will build in at all TAF sites by 07z-10z (with ATL
on the earlier side) and will persist thru the morning. Periods 
of IFR ceilings will be possible, especially with TSRA as a line 
of SHRA and convection moves thru the ATL-area sites and AHN 
between 11z-15z. The convection is forecast to impact MCN and CSG 
between 13z-18z. SW winds at 12-18 kts and gusts at 25-30 kts will
accompany the convection. Winds will remain gusty thru the 
afternoon and evening, though with a more westerly direction.

//ATL Confidence...06Z Update...
Medium to high confidence on all elements.

Martin


&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          45  71  48  71 /   0   0  10  30 
Atlanta         45  70  50  71 /   0   0  20  40 
Blairsville     36  68  44  65 /   0   0  10  30 
Cartersville    41  70  48  71 /   0   0  20  40 
Columbus        49  75  54  76 /   0   0  20  50 
Gainesville     44  70  48  68 /   0   0  10  30 
Macon           50  74  52  76 /   0   0  10  30 
Rome            42  71  48  73 /   0   0  20  40 
Peachtree City  44  71  50  74 /   0   0  20  50 
Vidalia         54  76  53  79 /  20   0   0  20 

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 8 AM this morning to 11 PM EDT this evening 
for GAZ001>009-011>016-019>025-027-030>039-041>055-057.

&&

$$

SHORT TERM...Morgan
LONG TERM....King
AVIATION...Martin