120
FXUS62 KFFC 261619
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
1219 PM EDT Thu Sep 26 2024

.UPDATE...
Issued at 1217 PM EDT Thu Sep 26 2024

Other than the Excessive Rainfall Forecast day 1 graphic from WPC
connecting the high risk areas from the Appalachians to the Gulf
Coast, no major changes to overall impacts have occurred, and the
forecast is generally unchanged. /SEC

&&

.SHORT TERM...
(Today through Friday)
Issued at 326 AM EDT Thu Sep 26 2024

No changes to the current hazards for this forecast cycle. The
forecast will be dominated by Helene.

Hurricane Helene has emerged into the Gulf of Mexico. She will
continue to move northward today and should make landfall along the
Florida Big Bend coast this evening. After landfall, the remnants of
Helene will move northward very quickly across the state overnight
and then take a NW jog into the TN valley on Friday. Some weakening
is expected after Helene moves inland, but with such quick movement
northward, damaging wind gusts from the storm will be more likely
further inland.

Rainfall: Yesterday`s PRE (Predecessor Rain Event) has helped
saturate the soils across much of the CWA. Rainfall totals along the
Interstate 85 corridor ranged from 2 to 4 inches, with some locally
higher amounts ranging from 4 to 5 inches. The heavy rainfall axis
is expected once again today along the Interstate 85 corridor, with
amounts ranging from 3 to 5 inches, with locally higher amounts
likely. With Helene moving quickly northward overnight and early
Friday, the axis of heavier rainfall should shift to the NE portion
of the CWA. Rainfall totals overnight will average another 2 to 4
inches, with locally higher amounts, especially in the higher
elevations of NE GA. By Friday, the remnants of Helene will push off
to the NW. Rainfall should begin to taper off across the area, but
another one quarter of an inch to an inch is possible north of the
I-20 corridor. Adding all of this up, storm total QPF for today
through Friday should average another 3 to 6 inches with locally
higher amounts of up to around 8 inches possible.

Winds: Winds with the remnants of Helene will be stronger than what
is typical further inland due to her quick movement. The strongest
winds are expected to impact the CWA this evening through Friday.
For later this afternoon into the late evening, the strongest winds
should mainly be south of the Interstate 20 corridor. For overnight
and early Friday, areas north of the Interstate 20 corridor should
see the highest winds. The wind speed/gust potential will decrease
the further north the remnants of Helene moves, but wind gusts up to
70 to 80 mph can be expected well inland into northern GA.

Tornadoes: The best potential for tropical tornadoes within the
outer rainbands of Helene will be mainly along and east of a line
from Helen to Peachtree City to Columbus. The tornado potential will
begin to increase across SE portions of the state later this
afternoon and then spreading northward overnight.

NListemaa

&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 326 AM EDT Thu Sep 26 2024

Other than ongoing river flooding, no major weather impacts or
forecast concerns expected in the long term period (sure feels good
to write that).

By Friday night at the start of the long term period, the heavy rain
and winds associated with Helene will be will north and northwest of
the area. There will be lingering flooding on the larger, mainstem
rivers, but with only small chances for scattered showers over far
northern counties Fri night through Sat night, water levels will
finally recede.

Dry weather should persist through the rest of the long term
forecast period as the cutoff low post-Helene remains north of us
and slides east Sunday/Monday with weak NW flow and general
subsidence. A flat upper ridge may also develop over Texas and the
mid-South late in the period as well.

Tropical activity and development will continue in the Atlantic
basin over the next 7 days but no storms are expected to threaten
the CONUS.

SNELSON

&&

.AVIATION...
(12Z TAFS)
Issued at 737 AM EDT Thu Sep 26 2024

IFR/LIFR and east winds for the entire period. VSBYS generally 3-6SM
in SHRA with tempo periods reduced to 1SM in heavier shra in bands.
Timing is nebulous right now, so will likely have to add tempo/prob
groups at a later time. Wind speeds/gusts pick up by early afternoon
and increase from there. Gusts to around or just under 50kt just
before 12Z.

//ATL Confidence...12Z Update...
Med confidence all elements.

NListemaa

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          69  76  62  78 / 100  60  10  10
Atlanta         67  74  63  77 / 100  50  10  10
Blairsville     66  68  58  69 / 100 100  30  40
Cartersville    67  74  62  77 / 100  70  20  20
Columbus        66  79  64  82 / 100  30   0  10
Gainesville     68  73  63  75 / 100  90  20  20
Macon           68  79  62  82 / 100  30   0   0
Rome            67  74  63  77 / 100  90  20  30
Peachtree City  65  75  62  77 / 100  40  10  10
Vidalia         73  83  66  85 / 100  20   0   0

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Friday afternoon for GAZ001>009-011>016-
019>025-027-030>039-041>062-066>076-078>086-089>098-102>113.

Tropical Storm Warning for GAZ001>009-011>016-019>025-027-
030>039-041>062-066>068-072>076-078-084>086-097-098-111>113.

Hurricane Warning for GAZ069>071-079>083-089>096-102>110.

$$

SHORT TERM...SEC
LONG TERM....SNELSON
AVIATION...NListemaa