005
FXUS62 KFFC 201450 AAA
AFDFFC

Area Forecast Discussion...UPDATED
National Weather Service Peachtree City GA
1050 AM EDT Sat Jul 20 2024



...Morning Update...

.UPDATE...
Issued at 1035 AM EDT Sat Jul 20 2024

Currently monitoring a cluster of showers and thunderstorms
moving into northwestern Georgia from Alabama at the time of this
writing. Localized heavy rainfall and frequent cloud-to-ground
lightning are likely with the stronger cells in this cluster.
Additionally, cells are beginning to develop across south-central
Alabama and the Florida Panhandle amid breaks in the cloud cover
and are tracking toward the northeast, so expect coverage of
showers and storms to increase in coverage across much of the CWA
heading into the afternoon.

Martin


&&

.SHORT TERM...
(Today through Sunday)
Issued at 639 AM EDT Sat Jul 20 2024

A 500 mb shortwave is progressing eastward as a stationary
boundary remains draped over north Georgia. At the time of this
writing, an MCV-like feature over eastern central Alabama is
producing showers with a few embedded lightning strikes. As this
shifts eastward, areas across the metro are expected to incur yet
another round of rain through the early morning hours. With low
cloud ceilings and areas of patchy fog developing across much of
the area this morning, temperatures will be slow to warm through
the day, limiting our max daily temperatures in the 80s for most
areas. Despite this, models depict a northward progression of an
unstable airmass through the day that will prime the area for the
next round of activity this afternoon and evening. SBCAPE between
1000-2000+ J/kg across much of the area today will be enough to
support a few thunderstorms through the afternoon, but in the
absence of any appreciable shear and meager 700-500mb lapse rates,
the risk for severe weather remains low. On the other hand, PWATs
running between 1.8-2.2" will make for localized flash flooding
instances a concern in stronger storms, particularly over areas
that have experienced repeated rounds of rainfall.

Tonight, activity is generally expected to diminish after sunset
with a few showers and thunderstorms remaining possible through
the early morning hours. As another shortwave dives down from the
midwest Sunday and the surface boundary meandering over northern
Georgia Sunday, a similar active weather day with multiple rounds
of numerous showers and thunderstorms is expected. With the
airmass more or less unchanged, thunderstorms are expected to
remain subsevere with a localized flash flooding in the strongest
storms.

KAB


&&

.LONG TERM...
(Sunday night through Friday)
Issued at 639 AM EDT Sat Jul 20 2024

Key Messages:

 - Storm chances will continue through the workweek, with daily
   rain chances peaking (50-80%) during the afternoon and evening
   hours each day.

 - Slightly below average high temperatures (by 2-5 degrees) are
   favored in northern and central Georgia through next Thursday.

Ample Rain Chances for the Workweek:

The overall theme of the forecast for the upcoming workweek
remains relatively unchanged over the last 24 hours. Through
Thursday the broad synoptic pattern should consist of an upper
level trough over the Midwest and upper level ridge in the
Atlantic. The prevailing southwesterly flow between these two
features will continue to funnel subtropical moisture into Georgia
from the Gulf of Mexico. Upper level ridging may creep westward
on Friday, but moisture should remain elevated in the region.
Precipitable water values at or above the 90th percentile (1.8-2.1
inches) are expected through Friday (per GEFS & EPS means). The
elevated moisture levels in the region will favor continued shower
and thunderstorms activity. Projections from the GEFS and EPS
suggest positive 5 day rainfall anomalies of 0.5 to 2 inches
between Monday and Friday, with the highest values occurring over
northern Georgia. Storm chances should primarily be diurnally
driven, though some convection could linger through the overnight
period each day. Warm air in the mid levels should limit lapse
rates (700-500 mb 5.5 C/km or less) all week, and this should keep
MUCAPE values modest (500-1500 j/kg). Toss in a lack of
appreciable shear, and severe weather appears unlikely this week.

Ensemble guidance continues to lean towards below average high
temperatures this week, due largely to the potential for enhanced
cloud cover and rainfall each afternoon. A glance at the NBM high
temperature guidance for Atlanta suggests at least a 75% chance of
below average high temperatures each day between Monday and
Friday. Thus we have moderate confidence in high temperatures
being 2 to 5 degree below seasonal averages this week. Look for
this to translate into highs in the 80s over northern Georgia, and
upper 80s/lower 90s in central Georgia.

Albright


&&

.AVIATION...
(12Z TAFS)
Issued at 644 AM EDT Sat Jul 20 2024

Mixed bag of VFR/MVFR/IFR this morning. Metro sites may see
periods of IFR from 12-14Z with all terminals settling in to MVFR
after 15- 16Z through the evening. SHRA/VCSH will continue this
morning with TSRA this afternoon between roughly 18-23Z at all
terminals. VFR cigs/vsbys will return briefly during the early
morning hours before deteriorating to IFR. May see isolated SHRA
overnight and in the morning hours. SW winds will generally be
light and VRB at times but there may be periods of light SSE
through 16Z.

//ATL Confidence...12Z Update...
Medium confidence on all elements.

KAB


&&

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

&&

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

$$

SHORT TERM...KAB
LONG TERM....Albright
AVIATION...Martin