954
FXUS62 KFFC 230745
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
345 AM EDT Mon Sep 23 2024



...Morning Area Forecast Discussion...

.SHORT TERM...
(Today through Tuesday)
Issued at 332 AM EDT Mon Sep 23 2024

500mb analysis shows NW flow aloft with a high pressure anchored
off the SE coast of TX. This high center should migrate eastward
across the northern GOMEX through the period. The mid level flow
across the state should go briefly zonal and then SW by early
Tuesday as a longwave trough pushes into the Mid Mississippi River
valley.

At the surface, a weak surface trough continues across central
portions of the state. A weak frontal boundary will approach from
the west through the period while ridging remains across the
northern GOMEX. Moisture will continue to slowly increase across
the area, along with the chances for pops, especially across the
northern tier of zones. The southern tier of zones will be closest
to the mid level and surface ridges and pops remain lowest in
this region. Pops will remain isold/sct in nature across the
northern half of the CWA through the period. Severe weather is not
anticipated at this time.

Temps continue above normal through the period. Adjusted the MaxT
values upwards a couple of degrees from the blend. ATL may
approach another record high for the next two days.

NListemaa


&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 332 AM EDT Mon Sep 23 2024

At the upper levels, a positively-tilted trough will be
positioned over the eastern CONUS at the start of the long-term
period. At the surface, a weak area of low pressure over the Ohio
River Valley and eastern Great Lakes region will push a weak cold
front across the Tennessee River Valley, perhaps making it into
north Georgia. As a result, rain chances will be greatest
generally along and north of the I-85 corridor Tuesday night
through Wednesday night. Both instability (CAPE and mid-level
lapse rates) and wind shear from the surface to 500 mb will be
marginal at best, indicating that while isolated to scattered
thunderstorms are expected, widespread severe weather is unlikely.

The impactful portion of the long-term period will be Thursday
through Saturday. The National Hurricane Center (NHC) is
indicating a high (70%) chance for tropical development over the
northwestern Caribbean Sea and adjacent portions of Central
America in the next 48 hours. Ultimately, a tropical depression or
tropical storm is very likely (90% chance) to develop in the next
few days as the system moves northward into the southeastern Gulf
of Mexico. During the latter half of the week, the system is
expected to track generally northward across the eastern Gulf.

At 4-5 days out, it is still best to lean on ensemble guidance to
get an idea of the potential evolution of the system and
potential impacts on the Southeast. The GEFS moves the system
northward slightly faster than does the EPS, but the tracks that
both ensembles depict are very similar, with the system having a
spatial extent from Florida to Louisiana. The track of this system
will depend largely on how the aforementioned upper-level trough
evolves over the eastern CONUS (its strength, position, southern
extent) and thus how it steers the system.

The degree of impacts across north and central Georgia is still
relatively uncertain, but we are currently expecting most impacts
to occur on Thursday and Friday. As far as impacts, periods of
heavy rainfall and resulting flash flooding and/or river flooding,
gusty winds, and tornadoes will be on the table should north and
central Georgia be on the eastern side of the system. Forecast
rainfall totals are largely unchanged from the previous forecast
package, with essentially area-wide totals of 3" to 4". Localized
swaths of 5" or more are possible in the event of intense and/or
long-lived rainbands, but it is futile to attempt to pin down
where such rainfall maxima could occur at 4-5 days out.

Residual tropical moisture, along with what ensemble guidance
suggests is expansive upper-level troughing, looks to keep 20% to
30% PoPs in the forecast on Saturday and Sunday. Aside from
Wednesday, highs will be in the 70s and 80s thanks to increasing
cloud cover and increasing coverage of showers and storms.

Martin


&&

.AVIATION...
(06Z TAFS)
Issued at 123 AM EDT Mon Sep 23 2024

VFR through the period with sct afternoon cu and cirrus. Winds
will remain westerly with slightly increasing speeds.

//ATL Confidence...06Z Update...
High confidence all elements.

NListemaa


&&

.CLIMATE...
Issued at 332 AM EDT Mon Sep 23 2024


Records for 09-23

               Max Temperature         Min Temperature
  Station      High        Low         High        Low
  -------  ----------  ----------  ----------  ----------
   KAHN     102 1931     64 1947     72 1931     43 1918
                                        1925        1913
   KATL      94 1931     61 1995     75 1931     45 1982
   KCSG     100 1925     65 1929     74 1980     45 1983
                                        1926
   KMCN      98 1970     61 1897     74 1980     46 1999
                1925



Records for 09-24

               Max Temperature         Min Temperature
  Station      High        Low         High        Low
  -------  ----------  ----------  ----------  ----------
   KAHN     103 1931     59 1995     72 1940     30 1928
                                        1931
                                        1925
   KATL      93 1980     56 1995     73 2019     45 1990
                                        1980
                                        1931
   KCSG     100 1921     61 1995     74 2009     47 1982
                            1975
   KMCN      98 2019     59 1995     73 1980     44 1967
                                        1930



&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          94  70  90  69 /  30  20  30  30
Atlanta         94  73  91  70 /  20  20  20  40
Blairsville     85  65  83  63 /  30  20  30  60
Cartersville    93  70  91  68 /  30  20  20  40
Columbus        95  73  92  72 /  20  10  10  20
Gainesville     92  70  88  68 /  30  20  30  40
Macon           96  72  93  70 /  20  20  10  10
Rome            93  69  91  68 /  30  20  30  50
Peachtree City  94  71  91  69 /  20  20  20  30
Vidalia         92  71  92  70 /  20  20  10   0

&&

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

$$

SHORT TERM...NListemaa
LONG TERM....Martin
AVIATION...NListemaa