Alpharetta, Georgia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

263
FXUS62 KFFC 120101
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
901 PM EDT Mon Aug 11 2025

...Late Evening Update...

.UPDATE...
Issued at 830 PM EDT Mon Aug 11 2025

Scattered showers and thunderstorms continue across the state this
evening. Thunder activity should begin tapering off over the next
few hours, though instances of light rain and/or drizzle is likely
to continue overnight. Thunderstorms have produced decent heavy
rainfall across portions of Central Georgia this evening with rain
rates in the 2-3 inch range with some isolated rates up to nearly
4 inches. Thankfully this activity has been moving which has
limited flooding concerns this evening. Another round of patchy
fog and low clouds are expected to develop areawide overnight
lasting through early Tuesday.

&&

.SHORT TERM...
(This afternoon through Tuesday)
Issued at 253 PM EDT Mon Aug 11 2025

Key Messages:

- Scattered to widespread showers and a few storms are expected
  today and tomorrow. Locally heavy rainfall is expected.

- Relatively cooler-than-average daytime temperatures will
  prevail thanks to increased cloud cover and coverage of precip.

Discussion:

Southeasterly flow rounding the Bermuda High -- along with a weak
disturbance/inverted trough over the Florida Panhandle -- is
advecting tropical moisture across north and central Georgia, with
PWATs generally ranging from 2.0" to 2.4". Relatively dense cloud
cover will prevail through the rest of the day, which should
limit at least surface-based instability. That said, MLCAPE ranges
from 1000-2000 J/kg per SPC Mesoanalysis, and thunderstorms have
developed across the eastern portion of the CWA, where MLCAPE is
highest at this time. The potential for any severe storms is
relatively low, given poor mid-level lapse rates amid the well-
saturated environment (updrafts will struggle to have "oomph" and
thus downdrafts will generally not be strong). Some storms will
produce localized gusty winds, torrential downpours, and frequent
lightning. Given the persistent feed of moisture and the
aforementioned disturbance providing lift, isolated to scattered
showers and possibly a few storms will persist overnight.

The disturbance is progged to lift northward tomorrow (Tuesday),
bringing another round of low morning clouds, as well as scattered
to widespread showers and a few storms. Weak steering flow will
support storm motion speeds of just ~10 kts, and with such high
PWAT values across the CWA, will need to watch for training storms
producing torrential rainfall and potentially localized flash
flooding. The CAMs and the HREF localized probability- matched
mean (LPMM) depict a strong signal for convection becoming focused
generally along and north of the I-85/I-20 corridors, and WPC has
introduced a Slight Risk (level 2 out of 4) for flash flooding
roughly along and north of the I-20 corridor. The higher
terrain/mountains of north Georgia may especially be favored for
efficient rainfall-producing storms thanks to southerly flow
lifting over the topography. Fairly widespread rainfall totals of
1.0 to 1.5 inches are expected, with localized totals as much as
3 to 5 inches possible (a reasonable "worst case" scenario).

Martin

&&

.LONG TERM...
(Wednesday morning through next Sunday)
Issued at 253 PM EDT Mon Aug 11 2025

Key Messages:

    - Daily afternoon/evening thunderstorm chances through the
      weekend (highest chances Wednesday).

    - Temps returning to seasonal norms by mid to late week.

Discussion:

The extended forecast continues with afternoon and evening
showers and thunderstorms expected each day. Temps also climb back
to near seasonal norms by Thu/Fri with highs back to near 90
north to the mid 90s across central GA. Starting Wed, the upper
level ridge over the Atlantic from the short term will have moves
east becoming centered just off the western FL coast. This upper
level ridge will keep deep moist southwesterly flow over GA with
small vort maxes pushing into the area. This flow becomes a bit
more westerly by Fri keeping moist flow over the area through the
weekend. With day time heating and temps expected to get back up
to seasonal norms we will continue to see afternoon and evening
showers with increased chances of thunderstorms through day 7.
This strong upper level ridge becomes centered over the northern
Gulf by Fri/Sat which will help to keep any storms that develop
capped from becoming too strong or severe.

Vaughn

&&

.AVIATION...
(00Z TAFS)
Issued at 718 PM EDT Mon Aug 11 2025

Scattered -SHRA and -TSRA continue in and around most sites this
evening. -TSRA chances should wane overnight though -RA/-DZ may
persist. VFR cigs will gradually give way to IFR and LIFR cigs
overnight and early Tuesday morning. Patchy BR is also likely
especially at sites that received any -SHRA/TSRA like KMCN. Winds
largely remain out of the E at 5 to 12Kts, shifting to the ESE at
less than 7kts overnight, and then to the SSE (possibly SSW at
KCSG/KMCN) on Tuesday afternoon.

//ATL Confidence...00Z Update...

Medium confidence on cigs/vsbys overnight/early Tuesday morning.
High confidence on remaining elements.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          73  81  70  82 /  30  70  50  60
Atlanta         74  88  72  82 /  20  70  50  70
Blairsville     70  82  67  78 /  20  60  40  60
Cartersville    74  87  71  84 /  10  60  40  70
Columbus        75  87  72  86 /  20  70  60  60
Gainesville     72  82  69  81 /  30  60  50  60
Macon           74  87  72  86 /  30  70  60  50
Rome            73  87  72  85 /  10  50  30  70
Peachtree City  73  86  71  83 /  20  70  50  70
Vidalia         73  89  73  91 /  50  70  40  40

&&

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

$$

SHORT TERM...Martin
LONG TERM....Vaughn
AVIATION...07