Special Weather Statement, NWS Atlanta, GA

Area Forecast Discussion
National Weather Service Peachtree City GA
309 PM EDT Mon Jun 29 2020

...Afternoon Area Forecast Discussion for Monday, June 29th...

.SHORT TERM /Tonight through Tuesday Night/...

Despite some ridging and drier upper layer, the ample diurnal
heating and pretty high MLCAPE near 2500 J/kg is allowing for
isolated convective triggering potential area-wide this afternoon
into evening. Some stronger storms with gusty winds are possible
and an isolated severe cannot be ruled out.

Tuesday should be a shift to a more active pattern as ridge
dampens further allowing for more zonal to broadly NW flow aloft
and some ample deep layer moisture to where any weak perturbations
could trigger more widespread to numerous showers and storms. SPC
Day 2 Outlook also has northern and eastern portions of the CWA
in a Marginal Risk, but could see some strong to isolated severe
development area-wide with enhanced downdraft damaging wind
potential given such an environment.

Have some increasing pops in the north even for late Tuesday
night into early Wed with a possible shortwave amplifying across
the TN Valley and southern Appalachians.

Temps look to be a bit lower and closer to climo norms for
Tuesday given aforementioned increased moisture and expected
increased convective coverage.

Baker

.LONG TERM /Wednesday through Monday/...

Forecast begins on Wednesday with the Omega block in the upper-
levels over the CONUS beginning to break down as the poleward
extent of the ridge reaches a breaking point. This causes an
anticyclonic wave break on the poleward side of the jet and
absorption of the cut-off low to the NE into the flow over the
course of the forecast period, by the end of which a weaker, more
poleward, and more zonal jet is established, keeping the CWA far
removed from any baroclinically driven systems. In other words,
another summer continues.

On Wednesday into Wednesday night, a weak impulse near MO and IL
that has been meandering about under the large scale ridge will
move south to the west of the CWA through the Tennessee River
Valley. Timing of the wave as well as any upstream, overnight
convection will be important to the overall evolution of any
convection which develops over the CWA, and several CAMs show
differing solutions at the very beginning of the forecast period.
However, ample moisture will be in place, and destabilization due
to day time heating should occur allowing for some thunderstorms
to form. Effective shear values will be much better compared to
previous days, allowing for the potential of some organization and
longevity of storms.

Moving forward, this weak impulse should stick around for a few
days, keeping plenty of moisture around that should translate to
increased afternoon and evening thunderstorm chances. Recent model
runs of the GFS have showed the potential for a weak low to form
along the gulf coast over the weekend as the weak impulse moves
into the gulf, which would bring an increased potential for
rainfall especially over middle GA. However, plenty of uncertainty
remains given the timeframe, inherent global model difficulties
in handling these types of impulses that are removed from the
larger scale flow, and likelihood of mesoscale processes to impact
this feature which simply will not be handled well by global
scale models.

Have gone with the model blend, with some overall increases to
PoPs to account for diurnal convection potential.

Lusk

&&

.AVIATION...
18Z Update...
VFR conditions currently with cu field in 4-6 kft range and some
isolated showers across the area. Have tempo for TS and 5SM across
all sites from 20-24z then should diminish for overnight. Chances
increase for Tuesday so have prevailing SHRA after 18z and prob30
for TS. Winds mainly WNW 7-10 kts with some possible low end
gusts, decreasing to light WNW to calm overnight and back to 7-9
kts for Tuesday.

//ATL Confidence...18Z Update...
High on all elements.

Baker

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          73  92  70  89 /  20  60  30  60
Atlanta         73  89  71  88 /  20  60  40  60
Blairsville     66  82  65  80 /  30  70  60  80
Cartersville    70  88  69  86 /  20  70  40  70
Columbus        75  92  73  93 /  10  50  30  60
Gainesville     72  88  70  85 /  20  60  40  60
Macon           74  93  72  93 /  10  50  30  60
Rome            71  88  70  86 /  20  70  50  70
Peachtree City  72  89  70  89 /  10  60  40  60
Vidalia         77  96  74  94 /  10  50  30  60

&&

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

SHORT TERM...Baker
LONG TERM....Lusk
AVIATION...Baker

Hazardous Weather Outlook
National Weather Service Peachtree City GA
947 AM EDT Mon Jun 29 2020

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-301400-
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-
947 AM EDT Mon Jun 29 2020

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

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

Scattered thunderstorms are possible this afternoon and evening.
Some storms could be strong to severe with damaging winds, heavy
rain and frequent lightning.

Heat indices this afternoon will range from the upper 90s in
north Georgia to 104 in parts of central Georgia. Be sure to stay
hydrated and take frequent breaks if spending extended time
outdoors this afternoon.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday...

Scattered to numerous showers and thunderstorms will be possible
each afternoon and evening. Gusty winds, frequent lightning, and
heavy rain will be possible with any storms that do develop.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

Special Weather Statement
National Weather Service Peachtree City GA
425 PM EDT Mon Jun 29 2020

GAZ014-022-023-292100-
Hall GA-Dawson GA-Forsyth GA-
425 PM EDT Mon Jun 29 2020

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN HALL...SOUTHEASTERN
DAWSON AND NORTHEASTERN FORSYTH COUNTIES UNTIL 500 PM EDT...

At 425 PM EDT...a strong thunderstorm was over War Hill Park, or 7
miles west of Gainesville...moving southeast at 20 mph.

  HAZARD...Up to 40 mph wind...pea sized hail and frequent cloud to
           ground lightning.

  IMPACT...Expect minor damage to tree limbs and blowing around of
           light...unsecured objects.

Some locations in the path of this storm include
Gainesville, Flowery Branch, Oakwood, Candler, Aqualand Park,
Chestatee, Chestnut Mountain, Oscarville, Road Atlanta-Lanier
Speedway and War Hill Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People outdoors should seek shelter immediately. If you can hear
thunder...you are close enough to be struck by lightning.

LAT...LON 3426 8366 3410 8387 3411 8390 3432 8411
      3441 8400
TIME...MOT...LOC 2025Z 308DEG 17KT 3431 8395

HAIL...0.25IN
WIND...40MPH

Special Weather Statement
National Weather Service Peachtree City GA
443 PM EDT Mon Jun 29 2020

GAZ001>004-011-012-019-292115-
Chattooga GA-Whitfield GA-Catoosa GA-Walker GA-Gordon GA-Dade GA-
Floyd GA-
443 PM EDT Mon Jun 29 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN CHATTOOGA...SOUTHWESTERN
WHITFIELD...SOUTHWESTERN CATOOSA...WALKER...NORTHWESTERN GORDON...
SOUTHWESTERN DADE AND NORTHEASTERN FLOYD COUNTIES UNTIL 515 PM EDT...

At 442 PM EDT...a strong thunderstorm was near Center Post, or near
Lafayette...moving east at 15 mph.

  HAZARD...Up to 40 mph wind...pea sized hail and frequent cloud to
           ground lightning.

  IMPACT...Expect minor damage to tree limbs and blowing around of
           light...unsecured objects.

Some locations in the path of this storm include
Dalton, Lafayette, Summerville, Trion, Naomi, Center Post, Rising
Fawn, Subligna, Suttles Mill, Noble, Wood Station, Rocky Face, Lake
Marvin, Mill Creek, Linwood, Beaumont, Villanow, Sugar Valley,
Everett Springs and Cooper Heights.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People outdoors should seek shelter immediately. If you can hear
thunder...you are close enough to be struck by lightning.

LAT...LON 3481 8552 3485 8532 3483 8502 3462 8493
      3445 8514 3453 8552 3473 8556
TIME...MOT...LOC 2042Z 280DEG 14KT 3462 8527

HAIL...0.25IN
WIND...40MPH