Special Weather Statement, NWS Atlanta, GA

Area Forecast Discussion
National Weather Service Peachtree City GA
736 AM EDT Thu Aug 31 2017

.PREV DISCUSSION... /Issued 436 AM EDT Thu Aug 31 2017/

SHORT TERM /Today through Friday/...

Wet short term forecast in store as the remnants of Harvey impact
the area as it lifts northward across the Tennessee Valley. Have
generally kept likely pops in for today with widespread showers and
embedded thunderstorms are expected. Precip will likely be in waves,
with breaks in activity allowing for some potential clearing in
cloud cover and better insolation. The environment will continue to
destabilize today as a warm front lifts northward and wedge over
northeast GA erodes. Expect convection to ramp up with solar heating
today. Tornado threat is non-zero across the CWA, but especially
over NW GA as storms interact with the warm front boundary. Enhanced
low level helicity and most instability will be over NW GA, and SPC
has this area in a Slight Risk for severe storms today. The
remainder of the CWA is in a Marginal Risk for severe storms.

Best precip coverage will transition across far north Georgia this
evening and overnight into Friday, and have followed suit with the
pops before the best moisture/dynamics exit late Friday. SPC has
north GA in a Marginal Risk through Friday.

Rainfall amounts into the weekend are lower than previous forecast
packages, and although there is still a possibility of localized
flash flooding, the potential is lower than thought earlier. See the
hydrology section below.

Temperatures through the short term remain below normal,
particularly across far north GA due to the placement of the warm
front, the precip coverage and insolation.

Hydrology...
Latest forecast rainfall amounts through Saturday are generally 1 to
1.5 inches, with the highest amounts over northeast GA. As waves of
precipitation impact the area, storms could produce periods of heavy
rain. The state should be able to handle these amounts without any
issue. However, in areas where these storms train, or move over the
same location, localized flash flooding is possible.

31

LONG TERM /Friday Night through Wednesday/...

The long term period begins with remnants of Harvey moving through
portions of the Tennessee and Ohio valleys with stacked upper low
progressing along with it. This should keep the heaviest precip
out of the local area but will not be able to go pop free
initially as extreme north gets grazed with isolated shra and
portions of central GA have enhanced mid level moisture requiring
low end chance pops. This general trend will continue through Sat
with isolated thunder also possible mainly during the afternoon
hours.

Mid level trough opens up and system becomes decidedly more
progressive on Sunday taking the most substantial moisture and
lift well NE of the area. Significant enough drying apparent in
both the GFS and ECMWF to warrant a no pop day along with
comfortable dewpoints in the upper 50s during the afternoon.
Tranquil conditions through Monday with max temps near seasonal
average but lows some 8 to 10 degrees below.

Next system to affect the area will be late Tue night into Wed as
another strong east coast rough takes shape allowing for a cold
front to move through the area. Some southern stream energy will
also phase in and depending on the timing of these 2 features,
could see another decent rainfall event with 1 to 2inches in some
locales.

Another shot of cool air in the wake of this system will allow for
mid 50s for low for the mountains, to around 60 all the way into
the Atlanta metro with highs possibly remaining in the 70s.

Deese

&&

.AVIATION...
12Z Update...
Light to moderate rain continues this morning, and coverage is
expected to increase through the morning. IFR conditions will
improve slowly through the morning, but expect MVFR/VFR by
afternoon. Best thunder chances accompany peak daytime heating,
and have gone with TEMPO for around 16-22z. Winds will be E-SSE at
5-10kt, then shift to the SSW around 12z Friday.

//ATL Confidence...12Z Update...
HIgh on wind direction and speed.
Medium on all other elements.

31

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          81  71  84  64 /  70  60  50  30
Atlanta         81  72  83  65 /  70  60  40  10
Blairsville     75  66  75  57 /  80  80  70  20
Cartersville    81  71  81  61 /  70  70  40  10
Columbus        85  74  87  69 /  70  40  30  20
Gainesville     77  70  81  63 /  80  70  70  10
Macon           86  73  87  68 /  60  40  40  40
Rome            82  70  79  61 /  70  80  50  10
Peachtree City  82  71  84  64 /  70  60  40  20
Vidalia         90  73  90  72 /  40  40  60  40

&&

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

SHORT TERM...31
LONG TERM....Deese
AVIATION...31

Hazardous Weather Outlook
National Weather Service Peachtree City GA
511 AM EDT Thu Aug 31 2017

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-010915-
Baldwin-Banks-Barrow-Bartow-Bibb-Bleckley-Butts-Carroll-Catoosa-
Chattahoochee-Chattooga-Cherokee-Clarke-Clayton-Cobb-Coweta-
Crawford-Crisp-Dade-Dawson-DeKalb-Dodge-Dooly-Douglas-Emanuel-
Fannin-Fayette-Floyd-Forsyth-Gilmer-Glascock-Gordon-Greene-
Gwinnett-Hall-Hancock-Haralson-Harris-Heard-Henry-Houston-Jackson-
Jasper-Jefferson-Johnson-Jones-Lamar-Laurens-Lumpkin-Macon-
Madison-Marion-Meriwether-Monroe-Montgomery-Morgan-Murray-
Muscogee-Newton-North Fulton-Oconee-Oglethorpe-Paulding-Peach-
Pickens-Pike-Polk-Pulaski-Putnam-Rockdale-Schley-South Fulton-
Spalding-Stewart-Sumter-Talbot-Taliaferro-Taylor-Telfair-Toombs-
Towns-Treutlen-Troup-Twiggs-Union-Upson-Walker-Walton-Warren-
Washington-Webster-Wheeler-White-Whitfield-Wilcox-Wilkes-
Wilkinson-
511 AM EDT Thu Aug 31 2017

This Hazardous Weather Outlook is for portions of North and Central Georgia.

.DAY ONE...Today and Tonight...

The remnants of Harvey will move north of the area today but
still allow for numerous showers and thunderstorms. There is a
slight chance of severe storms with this activity with isolated
tornadoes being the primary concern. Heavy rain will also be
present with the activity with isolated instances of flash
flooding possible, mainly in the normal poor drainage areas.

Strong wind gusts will be possible as well over portions of NW
Georgia, especially in the higher elevations. Wind gusts to 25 to
30 mph will be possible by this evening and conditions will need
to be monitored for a possible wind advisory.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday...

There will be a chance of thunderstorms across the area on Friday
and across mainly central Georgia Saturday  The main hazards will
be occasional lightning and locally heavy rainfall. A cold front
will bring another good chance of showers and thunderstorms to the
area late Tue into Wed.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

Special Weather Statement
National Weather Service Peachtree City GA
1226 PM EDT THU AUG 31 2017

GAZ091-092-103-104-311700-
Schley GA-Sumter GA-Marion GA-Webster GA-
1226 PM EDT THU AUG 31 2017

...SIGNIFICANT WEATHER ADVISORY FOR SCHLEY...WESTERN SUMTER...
SOUTHEASTERN MARION AND SOUTHEASTERN WEBSTER COUNTIES UNTIL 100 PM
EDT...

At 1226 PM EDT...a strong thunderstorm was near Centerpoint, or 7
miles southeast of Preston...moving northeast at 35 mph.

  HAZARD...Up to 40 mph wind...frequent cloud to ground lightning
           and heavy rain.

  IMPACT...Expect minor damage to tree limbs and blowing around of
           light...unsecured objects. Heavy rain may cause temporary
           street flooding especially in poor drainage areas.

Some locations in the path of this storm include
Americus, Ellaville, Preston, Plains, Andersonville, Putnam,
Friendship, Bumphead, La Crosse, Centerpoint, Dumas and Walls
Crossing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People outdoors should seek shelter immediately. If you can hear
thunder...you are close enough to be struck by lightning. Motorists
should slow down and be prepared for possible loss of control due to
hydroplaning.

LAT...LON 3197 8444 3193 8445 3192 8446 3192 8451
      3196 8460 3234 8439 3225 8422 3223 8422
      3223 8417 3221 8413 3219 8413 3219 8412
      3191 8438
TIME...MOT...LOC 1626Z 211DEG 30KT 3198 8446

WIND...40MPH