Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 112357 AAA
AFDFFC

Area Forecast Discussion...UPDATED
National Weather Service Peachtree City GA
757 PM EDT Tue Aug 11 2020

.UPDATE...
Forecast seems to be in good shape. Will tweak PoPs and Wx based
on current radar and satellite trends as storms mostly confined
to southern counties.

SNELSON


.PREV DISCUSSION... /Issued 308 PM EDT Tue Aug 11 2020/

SHORT TERM /Tonight through Wednesday Night/...

High pressure continues across the CWA this afternoon. Early morning
showers and thunderstorms plus thicker cloud cover have looks to
have hindered early convective development across portions of north
GA. Starting to see some convection pop up outside of the cloud
cover. Do think along and south of Columbus to Macon will see the
best coverage of storms this evening. As usual, few strong to severe
storms will be possible. Strong gusty winds and frequent lightning
strikes will be likely with the stronger storms, with damaging wind
gusts the primary severe weather hazard. Also, locally heavy
rainfall will be possible.

Scattered to numerous showers and thunderstorms will once again be
possible tomorrow afternoon/evening. Do expect a bit more coverage
than today.

Heat index values should remain below critical thresholds.

NListemaa

LONG TERM /Thursday through Tuesday/...

Only minor adjustments have been made to the extended forecast,
which will be characterized by an upper level longwave trough. As
the period begins, the trough axis is anticipated to be positioned
over the Mississippi River Valley, and will steadily push eastward
towards the Appalachians late in the week and over the weekend.
Moisture advection will continue across the area ahead of the
trough, allowing for humid conditions to continue during this time
as well. The abundant deep moisture and daytime instability will
lead to high precip chances each day, especially in the afternoon
and evening, through the end of the week and into the weekend.
Shortwave disturbances embedded in the upper level flow will aid
shower and thunderstorm activity, as well. The potential will remain
for a few strong to severe thunderstorms each day continuing through
the weekend.

Model discrepancies are still present with respect to when the
trough axis clears the area, with the latest GFS still producing a
faster solution than the ECMWF -- on Sunday night for the former as
opposed to Monday night for the latter. When this occurs, some drier
mid-level air is possible on the back side of the trough, which
would serve to inhibit rain chances. As a result, afternoon PoPs
have been limited to high-end chance to low-end likely during the
early parts of next week to account for this uncertainty. Ample
humidity across north and central Georgia, combined with high
temperatures mainly in the upper 80s to low 90s, will lead to heat
indices in the 100 to 105 range and just outside of advisory
criteria through the weekend.

King

&&

.AVIATION...
00Z Update...
VFR conditions expected tonight with only a small chance for MVFR
fog at KMCN. SHRA/TSRA this evening mainly south of forecast
locations though expect scattered SHRA/TSRA to develop again after
20Z Wed. Sfc winds will be light (< 5kts) from the W-NW tonight
and Wed due to very weak steering flow except at KAHN with should
be LV or light NE.

//ATL Confidence...00Z Update...
Medium confidence on SHRA/TSRA timing and likelihood Wed
afternoon.
High confidence on all other elements.

SNELSON

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          71  94  72  91 /  20  40  40  70
Atlanta         74  94  73  92 /  20  50  50  70
Blairsville     66  88  67  84 /  20  60  50  80
Cartersville    72  94  72  92 /  20  40  40  70
Columbus        74  96  74  93 /  30  50  50  70
Gainesville     71  92  71  89 /  20  40  40  70
Macon           72  96  73  92 /  30  40  40  70
Rome            72  95  72  93 /  20  30  30  70
Peachtree City  72  94  72  91 /  20  40  40  70
Vidalia         74  94  74  91 /  30  60  50  70

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SNELSON
LONG TERM....King
AVIATION...SNELSON


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