Special Weather Statement, NWS Atlanta, GA

Area Forecast Discussion
National Weather Service Peachtree City GA
227 PM EDT Mon Aug 7 2023

...New 18Z Aviation Discussion...

.SHORT TERM...
(Today through Tuesday)
Issued at 430 AM EDT Mon Aug 7 2023

Key Messages:

 - There is an Enhanced Risk (Level 3 of 5) of thunderstorms with
   damaging winds across northern Georgia this afternoon and
   evening.

 - A Heat Advisory has been issued for central Georgia from noon
   to 8 PM today, and precautions should be taken to avoid heat
   related illnesses.

 - Thunderstorms activity should continue in the region Tuesday,
   with a Slight Risk (Level 2 of 5) for severe weather in central
   Georgia.

Today & Tonight:

Today is shaping up to be one of those days where hot conditions
come to a crashing end as severe storms roll through. An
unseasonably strong trough will track through the Ohio Valley
today. This will provide the lift and shear necessary to support
storm development and maintenance. Meanwhile the heat and humidity
ahead of the approaching trough will result in SBCAPE values of
2500 to 4000 j/kg (per HREF guidance), ample fuel for strong
updrafts. Storms are ongoing in an unstable environment across
Tennessee and Kentucky already. As the morning progresses CAM
guidance suggests this activity will gradually congeal into a more
cohesive line, before it becomes more cold pool driven and surges
through northern Georgia this afternoon and evening. Trends in
the HRRR guidance suggest the line of storms will arrive in the
Atlanta Metro between 4 PM and 7 PM. Due largely to the
unseasonably strong shear, there is an above average threat for
widespread damaging winds with the storms today. Wind gusts in the
50 to 70 mph range could occur with the strongest storms, and
peak gusts near 80 mph aren't out of the realm of possibility. The
SPC has issued an Enhanced Risk (level 3 of 5) to highlight this
potential wind threat. With gusts of this magnitude, tree and
power line damage can be anticipated in the region. Please be sure
to heed any warnings issued for your area. The potential for
other hazards (tornados, large hail or flooding) are lower.

As noted above, heat will be a concern today. The core of the
heat is anticipated south of Interstate 20 where temperatures in
the mid to upper 90s will combine with dewpoints in the mid 70s to
produce heat indices in the 105 to 110 degree range. A Heat
Advisory has been issued to highlight increased potential for heat
related illnesses. Precautions should be taken to stay cool and
hydrated, especially as we are moving through the initial
practices for many fall sports.

The Outlook for Tuesday:

Another weak shortwave will slide east from Texas on Tuesday. As
this wave progresses through Mississippi, Alabama and Georgia it
should interact with a stationary frontal boundary left over from
todays activity. The result should be thunderstorm development
and potentially another MCS. This time though it looks like
central and southern Georgia would be zone favored for peak
activity. Isolated severe weather is possible (particularly
damaging winds) and the SPC has a Slight Risk (level 2 of 5) for
portions of Georgia.

With the storms most likely arriving during the morning and
afternoon hours, temperatures could be depressed in central
Georgia on Tuesday. We nudged our temperature forecast down by a
couple of degrees in this area, though additional decreases may be
necessary if model trends favoring rain and cloud cover continue.

Albright

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 430 AM EDT Mon Aug 7 2023

As we approach mid-week and move toward the weekend, the mid-level
ridge that has plagued the Desert Southwest for the better portion
of the summer becomes higher amplitude once again, setting the stage
for yet another round of northwesterly flow across the Southeast and
the potential for multiple rounds of convection supported by ridge
riders. For now, passing disturbances in mid-level flow look to move
eastward pretty much each day Wednesday through Sunday. Thursday's
disturbance is progged to be the strongest/most organized of the
bunch (and may briefly close off), supporting nearly continuous rain
chances through the 48hr period. A rather impressive 850mb jet -- 30
to 40kts of bulk shear, not unlike what we've seen multiple times
over the past month or two -- looks to swing through coincident with
the shortwave disturbance on Thursday, so given ample forecast
MUCAPE (1500-2500 J/kg) it will not be outside of the realm of
possibility to see an isolated strong to severe storm, capable of
producing damaging wind gusts. For now, our area is outlooked in a
Day 3 Marginal Risk which only briefly clips the Thursday time
period (through 8AM), but if conditions hold, would not be surprised
to see this bumped up and carried over in coming days.

The cold front that was the impetus for Monday's storms is forecast
to have stalled out across central Georgia and will linger for the
remainder of the period, serving as yet another focus for convective
activity. The location of it (though less and less impactful with
waning strength) and any remnant boundaries from the previous day's
thunderstorms will influence axes of highest rain chances.

With PWATs in the 1.75-2" range, storms will be efficient rain
producers, and care will need to be taken to monitor potential for
flooding concerns as the week progresses. Rainfall totals from
Wednesday through Friday are between 1-2" for areas along and north
of the I-85/I-20 connector, and as high as 3" in the terrain of
north Georgia. Waterlogged soils from multiple rounds of
precipitation are likely to make downing of trees and branches
easier, possible even in sub-severe storms. Otherwise, progged
afternoon thunderstorm activity will help to tamp down temperatures
even as the airmass moderates, to right around a degree or two of
normal (in the upper-80s to low-90s) each day.

96

&&

.AVIATION...
(18Z TAFS)
Issued at 224 PM EDT Mon Aug 7 2023

Main concerns will be thunderstorms and timing. Now that a solid
line of storms appears to be taking shape we can put a little more
confidence on timing for the sites later this afternoon/evening.
CAMS still struggling with any redevelopment behind the main line
and if there will be any but for now will assume the airmass
stabilizes behind the main surge.
Added prob30 for Tuesday as most convection is forecast to remain
across central GA sites however there is some guidance suggesing
some development post 18z across metro sites. Winds outside of
TS will remain west  and gusty this afternoon.

//ATL Confidence...18Z Update...
Medium confidence precip timing
high confidence all other elements

30

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          70  89  69  90 /  60  10  20  30
Atlanta         72  89  71  91 /  50  30  20  50
Blairsville     64  82  61  84 /  50  10  10  40
Cartersville    69  87  69  89 /  50  20  20  50
Columbus        75  94  73  92 /  20  60  40  60
Gainesville     71  87  69  89 /  60  10  10  40
Macon           73  94  72  92 /  30  50  40  50
Rome            69  88  68  89 /  50  20  20  60
Peachtree City  71  90  69  91 /  40  40  30  50
Vidalia         76  95  73  92 /  20  50  40  50

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT this evening for GAZ038-039-049>051-
058>062-066>076-078>086-089>098-102>113.

Excessive Heat Warning until 8 PM EDT this evening for GAZ072-
073-080>084-089>096-102>108.

&&

SHORT TERM...30
LONG TERM....KAL
AVIATION...30

Hazardous Weather Outlook
National Weather Service Peachtree City GA
453 AM EDT Mon Aug 7 2023

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-080900-
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-
453 AM EDT Mon Aug 7 2023

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

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

Northern Georgia has an Enhanced Risk (level 3 of 5) of
thunderstorms with damaging winds between 3 PM and 10 PM today.
This risk area includes the Atlanta Metro. The strongest storms
may produce 50 to 70 mph wind gusts, with isolated gusts near 80
mph not out of the realm of possibility. Winds of this magnitude
may cause widespread tree and power line damage if they
materialize. Please heed any warnings issued for your area.

A Heat Advisory is in place across central Georgia from noon to 8
PM today due to expected heat indices in the 105 to 110 degree
range. Be sure to take the necessary steps to stay cool and
hydrated.

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

There is a Slight Risk (level 2 of 5) for thunderstorms with
damaging winds in central Georgia on Tuesday.

Periods of thunderstorm activity will continue through next
Sunday. The highest storm chances will occur during the afternoon
and evening hours each day.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

Preliminary Local Storm Report
National Weather Service Peachtree City GA
1133 AM EDT Mon Aug 7 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0335 AM     Tstm Wnd Dmg     2 SW Experiment         33.25N 84.30W
08/06/2023                   Spalding           GA   Emergency Mngr

            Tree down at Newnan Rd and 85 Connector.

&&

Preliminary Local Storm Report
National Weather Service Peachtree City GA
218 PM EDT Mon Aug 7 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0209 PM     Tstm Wnd Dmg     1 WSW Hooker            34.97N 85.45W
08/07/2023                   Dade               GA   Emergency Mngr

            Trees down in Dade County with concentration
            across I-59 and I-24 interchange.

&&

Special Weather Statement
National Weather Service Peachtree City GA
221 PM EDT Mon Aug 7 2023

GAZ002-011-012-019-071900-
Chattooga GA-Walker GA-Gordon GA-Floyd GA-
221 PM EDT Mon Aug 7 2023

...A strong thunderstorm will impact portions of central Floyd,
southwestern Walker, western Gordon and Chattooga Counties through
300 PM EDT...

At 220 PM EDT, a strong thunderstorm was over Trion, or near
Summerville, moving east at 30 mph.

HAZARD...40 to 50 mph wind, pea sized hail and frequent cloud to
         ground lightning.

SOURCE...Radar indicated.

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

Locations impacted include...
Rome, Calhoun, Summerville, Trion, Resaca, Plainville, Shannon,
Lyerly, Menlo, Center Post, Pinson, Subligna, Lake Marvin, Coosa,
Cloudland, James H. Floyd State Park, Holland, Oostanaula, Tidings,
and Armuchee.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
northwestern Georgia.

&&

LAT...LON 3465 8551 3457 8493 3421 8513 3427 8546
      3463 8553
TIME...MOT...LOC 1820Z 255DEG 27KT 3456 8529

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Preliminary Local Storm Report
National Weather Service Peachtree City GA
223 PM EDT Mon Aug 7 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0220 PM     Tstm Wnd Dmg     Fort Oglethorpe         34.94N 85.26W
08/07/2023                   Catoosa            GA   Emergency Mngr

            Trees down in Chickamauga battelfield.

&&

Special Weather Statement
National Weather Service Peachtree City GA
225 PM EDT Mon Aug 7 2023

GAZ014-015-071915-
Dawson GA-Lumpkin GA-
225 PM EDT Mon Aug 7 2023

...A strong thunderstorm will impact portions of Lumpkin and central
Dawson Counties through 315 PM EDT...

At 225 PM EDT, a strong thunderstorm was near Auraria, or near
Dahlonega, moving east at 30 mph.

HAZARD...40 to 50 mph wind, pea sized hail and frequent cloud to
         ground lightning.

SOURCE...Radar indicated.

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

Locations impacted include...
Dahlonega, Dawsonville, Amicalola Falls State Park, Camp Merrill,
Juno, Fausett Lake, Auraria, Porter Springs, Nimblewill, McKee, Len
Foote Hike Inn, Garland, and Gooch Mountain Shelter.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
north central and northeastern Georgia.

&&

LAT...LON 3457 8386 3444 8396 3442 8425 3456 8429
      3465 8406 3464 8404 3466 8403 3469 8395
TIME...MOT...LOC 1825Z 255DEG 27KT 3452 8406

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Special Weather Statement
National Weather Service Peachtree City GA
233 PM EDT Mon Aug 7 2023

GAZ014-022-023-071915-
Hall GA-Dawson GA-Forsyth GA-
233 PM EDT Mon Aug 7 2023

...A strong thunderstorm will impact portions of northern Forsyth,
southeastern Dawson and west central Hall Counties through 315 PM
EDT...

At 233 PM EDT, a strong thunderstorm was over Coal Mountain, or near
Cumming, moving east at 35 mph.

HAZARD...40 to 50 mph wind, pea sized hail and frequent cloud to
         ground lightning.

SOURCE...Radar indicated.

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

Locations impacted include...
Gainesville, Cumming, Oakwood, Matt, Silver City, Chestatee,
Oscarville, Coal Mountain, 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.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
north central Georgia.

&&

LAT...LON 3421 8418 3430 8420 3440 8396 3435 8381
      3421 8384
TIME...MOT...LOC 1833Z 254DEG 28KT 3428 8409

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH