911
FXUS62 KFFC 201852
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
252 PM EDT Sat Jul 20 2024



...Afternoon Area Forecast Discussion...

.SHORT TERM...
(This afternoon through Sunday)
Issued at 248 PM EDT Sat Jul 20 2024

An upper-level trough axis is centered over the MS River Valley
with north and central GA beneath southwesterly flow aloft.
Something of a MCV can be seen on Visible/GeoColor satellite
imagery over north-central AL, which has contributed to
widespread convection spreading across much of the CWA. CIRA
Advected Layer Precipitable Water imagery and the 12z FFC sounding
depict deep-layer moisture across the Southeast, and with 1.8" to
2.3" of PWAT, localized heavy rainfall will be one of the main
hazards with storms for the rest of today. Recent waves of heavy
rain-producing storms have left near-surface soils quite saturated
across much of the CWA, so localized flash flooding and/or rapid
rises of creeks, rivers, and streams are possible where
persistent, heavy rainfall occurs. Additionally, precip-loading
in downdrafts could lead to damaging winds up to around 50 mph.
Widespread cloud cover and scattered to widespread precip will
keep temperatures in the 80s for the most part.

Isolated to scattered showers and thunderstorms are possible for
at least part of the overnight period as the feed of moisture and
broad ascent aloft persist. Overnight lows are forecasted to range
from the mid-60s to lower 70s under a mostly cloudy to overcast
sky. No real pattern change will take place tomorrow (Sunday) with
upper-level troughing and similar PWAT values to those today. As
such, expect scattered to widespread showers and thunderstorms
through the day with a peak in coverage in the afternoon and early
evening. Like today, high temperatures will generally be in the 80s.

Martin


&&

.LONG TERM...
(Monday morning through next Friday)
Issued at 248 PM EDT Sat Jul 20 2024

Key Messages:

     - Scattered to numerous afternoon and evening thunderstorms
       each day.

     - Slightly below normal high temperatures through the period.

A fairly stagnant upper level pattern will continue through most
of the period, with a ridge from the Atlantic to the FL peninsula
and a trough from the Great Lakes and OH Valley to the lower MS
Valley and E TX. This pattern will keep the area in moist S-SW
flow with occasional weak dynamic forcing focused mainly over the
NE portion of the area. As a result, scattered to locally
numerous, mostly diurnal showers and thunderstorms are expected.
The potential for convection continuing further into the night or
developing before midday will be highest over the NW portion of
the area (particularly associated with vorticity maxima associated
with the upper trough or any MCSs. Organized severe weather
remains unlikely, but isolated storms could become strong to
briefly severe with gusty winds and heavy rainfall the greatest
threats. Even though coverage of convection may be a bit less over
the SE portion of the area, this will be closer to the deepest
moisture axis and slower storm motion. As a result, although total
rainfall through the period should be higher to the NW, localized
flooding may be more of a concern to the SE. There are
indications that the upper trough may shift slowly to the E and
begin to weaken late in the coming week.

Lower heights due to the proximity of the aforementioned trough,
along with increased cloud cover, will keep afternoon high
temperatures mostly in the mid 80s across the N half of the County
Warning Area (with 70s in the NE mountains). Warmest temperatures
are expected near and SE of a Columbus to Macon line, closest to
the upper ridge position. High temperatures in those areas are
expected to remain mostly near 90 to the lower 90s. /SEC


&&

.AVIATION...
(18Z TAFS)
Issued at 145 PM EDT Sat Jul 20 2024

A couple forecast challenges for the TAF period... First,
evolution of convection through the evening. Have TEMPOs at all
sites. An earlier round of convection across the metro Atlanta
area and AHN may delay additional convection until later this
afternoon/evening. Second, expect ceilings to tank again overnight
into early tomorrow (Sunday) morning with widespread IFR
conditions. Periods of MVFR/IFR visibility are also expected.
Cannot rule out FEW/SCT LIFR clouds, too.

//ATL Confidence...18Z Update...
Medium confidence on convection, ceilings, and visibilities.
High confidence on all other elements.

Martin


&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          70  88  70  87 /  50  70  70  70
Atlanta         71  85  70  86 /  40  60  60  80
Blairsville     65  81  65  81 /  40  70  70  80
Cartersville    70  87  68  86 /  40  70  60  80
Columbus        72  90  72  91 /  40  70  50  90
Gainesville     70  85  70  85 /  40  70  70  70
Macon           71  90  70  91 /  30  60  50  80
Rome            70  86  69  86 /  40  60  60  80
Peachtree City  70  86  69  87 /  40  60  60  80
Vidalia         73  91  73  92 /  30  60  50  70

&&

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

$$

SHORT TERM...Martin
LONG TERM....SEC
AVIATION...Martin