Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 211909
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
309 PM EDT Thu Sep 21 2017


.SHORT TERM /Tonight through Friday Night/...

Very warm and muggy conditions persist across north and central
Georgia with temps in the 80s to lower 90s. A few storms have popped
up along the ridges of northeast Georgia but a weak flow aloft is
limiting development/movement off the higher terrain.

Through Friday night/early Saturday, an upper ridge of high pressure
will remain firmly entrenched across the mid-MS Valley and lower
Great Lakes region while a weak upr lvl circulation drifts (extends)
from eastern North Carolina to the Gulf Coast/panhandle of Florida.
Diurnally-driven, mainly afternoon and evening, convection will be
widely scattered (20-30%) at best, with no significant "driver" or
low lvl forcing nor wind shear to sustain anything long-lasting.
Temperatures will continue to run 5-10F degrees above normal.

DJN.83


.LONG TERM /Saturday through Thursday/...

A broad upper-level ridge will dominate the eastern CONUS over the
weekend. This ridge will draw moisture from the Atlantic Ocean over
the region to begin the extended period. Impulses within the upper
level flow will provide a focus for diurnally driven showers and
thunderstorms on Saturday afternoon. As such, PoPs in central and
northern GA could be as high as 30 percent. Not confident in
increasing PoPs beyond that due to a lack of surface-based forcing.
High relative humidity values coupled with light winds could lead to
areas of patchy fog in the early morning hours during the weekend.
The upper ridge will break down early next week and then re-develop
in the middle of the week.

GFS/ECMWF/NAM/Canadian models all continue to keep Hurricane Maria
well to the east of our region. No direct impact from Maria is
expected to occur in the extended forecast period and Maria will
instead pass through the South Atlantic Ocean beginning on Sunday.
Proximity of Maria off the east coast will maintain a general
northeasterly flow over the region which will keep temperatures
moderated and set up a zone of subsidence over the southeastern
CONUS, which will promote drier and more stable conditions. PoPs are
expected to decrease to minimal values beginning on Sunday and into
next week. Warm and generally dry conditions are also to be expected
throughout the remainder of the extended period.

KING


&&


AVIATION...
18Z Update...
Much of the area (North/Central GA) between an upr low over
eastern NC and an upr ridge over the mid MS Valley. Weak impulses
embedded within NNE flow aloft expected to trigger spotty showers
and isold tstms through this evening, but identifying specific
locations at this point is challenging. Looks like sfc winds will
start off N-NE, gradually becoming more E-NE Friday.

No major impacts overnight aside from localized ground
fog resulting in brief reduction to vsbys, especially around
KMCN. Friday, sct cumulus pop btwn 16-18z with isolated to widely
scattered short-lived aftn convection.

//ATL Confidence...18Z Update...
Medium to high on all elements.

DJN.83

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          66  86  66  85 /  20  20  10  10
Atlanta         70  85  69  85 /  20  20  10  10
Blairsville     58  82  60  82 /  20  30  20  20
Cartersville    66  87  66  86 /  20  20  10  10
Columbus        73  89  69  87 /  20  30  10  20
Gainesville     69  84  66  84 /  20  20  10  10
Macon           68  87  67  86 /  20  30  20  20
Rome            67  87  66  87 /  20  20  10  10
Peachtree City  65  86  66  85 /  20  20  10  20
Vidalia         70  88  69  86 /  20  20  20  20

&&

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

$$

SHORT TERM...DJN.83
LONG TERM....09
AVIATION...DJN.83


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