Special Weather Statement, NWS Atlanta, GA

Area Forecast Discussion
National Weather Service Peachtree City GA
747 AM EDT Thu Aug 20 2020

.UPDATE...

12z Aviation update below.

Baker

&&

.PREV DISCUSSION... /Issued 415 AM EDT Thu Aug 20 2020/

SHORT TERM /Today through Friday/...

Amplified upper trough axis remains west of the area placing the
region under continued enhanced southwesterly flow and ample Gulf
moisture advection. Forcing looks similar both today and tomorrow
with continued PVA/upper impulses aiding expected widespread
convective development. This combined with diurnally maximized
marginal progged instability again will allow for some strong to
isolated severe development with damaging winds, hail, frequent
lightning and locally heavy rainfall as the main threats. Have
categorical to likely pops across CWA both days accordingly.

Temps slightly below normal today with highs mainly in the mid to
upper 80s then a bit lower for Friday in the low to mid 80s for most
locations.

Baker

&&

.LONG TERM /Friday Night through Wednesday/...

The long term period picks up on Friday night with the deep
upper-level trough still centered over the ArkLaMiss with Georgia
on its eastern side. A 250 mb jet streak, DPVA, and moisture
advection across Georgia will set the stage for numerous showers
and thunderstorms on Saturday. PWATs ranging from 1.25" to 2"+
will be the story across north and central Georgia, so heavy rain
and localized flash flooding will be concerns. As far as the WPC
Excessive Rainfall Outlook, much of north Georgia is under a
Marginal Risk for flash flooding from Friday morning through
Saturday morning (Day 2). Far northwest Georgia and portions of
central Georgia are under a Marginal Risk from Saturday morning
through Sunday morning (Day 3). In addition to the heavy rainfall
threat, the GFS and ECMWF are progging bulk shear of 30-40 knots
across the CWA on Saturday, so a few storms could be strong to
severe with hail, gusty to damaging winds, and frequent cloud- to-
ground lightning.

The trough will flatten and lift northward on Sunday as the
Bermuda High expands westward across the Southeast. Moisture
advection will continue around the periphery of the high, so the
CWA will remain entrenched in a tropical airmass. The upper-level
flow will become largely zonal on Monday and Tuesday, though
models are progging moisture to remain abundant across the CWA. As
a result, the coverage of showers and storms for Monday through
Wednesday will depend largely on daily mesoscale boundaries
(outflow boundaries and sea breeze fronts) as well as the ultimate
tracks of Disturbance 1 and Tropical Depression 13. For now, I
have chance to likely PoPs on Sunday, and chance PoPs for Monday
through Wednesday.

Martin

&&

.AVIATION...
12Z Update...
Initial IFR cigs (possibly LIFR) around northern sites this
morning. Cannot rule out some brief reduced vsbys in next hour or
two given residual moisture from evening storms but left out of
TAFs for now. Cu field again 3-4 kft today with widespread
SHRA/TSRA in the afternoon that could linger into tonight and
early Friday. Again could get MVFR/IFR cigs (or lower) for Friday
morning. Winds stay east to SE 4-6 kts thru period.

//ATL Confidence...12Z Update...

Medium on overall SHRA/TSRA coverage and on Friday morning cigs.
High on all else.

Baker

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          86  68  82  66 /  70  70  90  60
Atlanta         85  69  83  67 /  80  80  80  60
Blairsville     79  64  76  62 /  80  80  90  60
Cartersville    86  69  83  67 /  80  80  80  60
Columbus        89  70  84  68 /  80  80  80  60
Gainesville     82  67  80  66 /  80  80  90  60
Macon           89  69  85  67 /  80  70  80  60
Rome            86  69  83  67 /  80  80  80  60
Peachtree City  86  68  82  66 /  80  80  80  60
Vidalia         91  72  87  70 /  60  60  70  60

&&

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

SHORT TERM...Baker
LONG TERM....Martin
AVIATION...Baker

Hazardous Weather Outlook
National Weather Service Peachtree City GA
1148 AM EDT Thu Aug 20 2020

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-211600-
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-
1148 AM EDT Thu Aug 20 2020

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

.DAY ONE...This Afternoon and Tonight...

Numerous to widespread thunderstorms are forecast this afternoon
and evening across north and central Georgia, and some
thunderstorms will persist overnight. A few storms could be
strong to severe. The main threats will be strong to damaging
winds, locally heavy rainfall, hail, and cloud-to-ground
lightning. There is also an increased risk of flash flooding,
mainly across north Georgia.

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

Numerous thunderstorms are expected Friday and Saturday across
the forecast area. Scattered thunderstorms are forecast Sunday
through Wednesday. A few storms could be strong to severe each
day, with strong to damaging winds, locally heavy rainfall, hail,
and cloud-to-ground lightning.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

Special Weather Statement
National Weather Service Peachtree City GA
1216 PM EDT Thu Aug 20 2020

GAZ024-201645-
Banks GA-
1216 PM EDT Thu Aug 20 2020

...SIGNIFICANT WEATHER ADVISORY FOR BANKS COUNTY UNTIL 1245 PM EDT...

At 1216 PM EDT...a strong thunderstorm was near Homer. This storm was
nearly stationary.

  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
Homer, Lula, Maysville, Pinefield Crossroads and Hollingsworth.

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 3449 8349 3440 8338 3433 8339 3432 8340
      3426 8352 3426 8354 3434 8365 3437 8367
      3441 8365 3442 8362 3444 8361 3445 8359
      3449 8355
TIME...MOT...LOC 1616Z 223DEG 3KT 3437 8355

WIND...40MPH