Special Weather Statement, NWS Atlanta, GA

Area Forecast Discussion
National Weather Service Peachtree City GA
810 PM EDT Thu Mar 25 2021

.UPDATE...

00z Aviation update below.

Baker

&&

.PREV DISCUSSION... /Issued 348 PM EDT Thu Mar 25 2021/

SHORT TERM /Tonight through Friday Night/...

Widespread showers and a few thunderstorms are underway across
north Georgia this afternoon, mainly along and north of a line
from Cedartown to Roswell to Flowery Branch, where a warm front is
situated. This warm front is extending out from a surface low
located over the ArkLaMiss, placing the CWA within a warm, moist,
unstable environment this afternoon. A Tornado Watch is in effect
for northwestern GA until 9 PM EDT, where 0-1 km SRH values are an
impressive 350-450 m^2/s^2. In addition to the tornado threat,
this area will be ripe for supercells capable of large hail and
damaging wind gusts through the afternoon and evening.

The threat for severe storms will continue overnight into early
Friday morning as the surface low (at that point located over the
Great Lakes region) drives a cold front across the CWA from west
to east. CAMs generally show a broken line of storms entering
northwestern GA around 02z-04z, pushing through metro Atlanta
between 05z-10z. The threat for severe storms will continue to be
maximized across northern and western GA, where several severe
weather parameters are forecast to come together. At the upper
levels, a strong shortwave trough will lift northeast across the
Great Lakes region overnight, maintaining broad ascent across the
CWA (though the strongest upper dynamics will remain well to our
northwest). Still, some 65-75 kts of bulk shear will be in place
over northern and western GA overnight. In addition, 0-3 km SRH
values of 350-450+ m^2/s^2 and 0-1 km SRH values of 250-350+
m^2/s^2 will maintain a threat for organized, rotating storms with
tornadic potential. RAP and NAM significant tornado parameter
values across this portion of the CWA are 3 to 6, so the concern
for isolated tornadoes (some strong and/or long-tracked possible)
is certainly there. Even with the nighttime arrival of the storms,
MUCAPE will be 1000-1500 J/kg and forecast soundings suggest mid-
level lapse rates around 7.5-8.0 C/km, so large hail will also be
a threat with the storms overnight.

The line of storms will continue progressing eastward tomorrow
morning into the afternoon across central and eastern GA, but
severe storm parameters look to be much more marginal. That said,
decent shear and instability could make for a few strong to severe
storms.

Martin

&&

.LONG TERM /Saturday through Thursday/...

At the start the forecast period on Saturday, the lingering
frontal boundary will begin to quickly lift back north across
north Georgia as a warm front. The best chance for rainfall will
thus be across the northern third or so of the area on Saturday.
Some embedded thunderstorm activity will be possible Saturday
initially associated with elevated instability north of the warm
front. Rainfall coverage will diminish farther south of the cold
front where temperatures will soar well into the 80s in central
Georgia.

On Sunday, shower and thunderstorm coverage will increase
appreciably as the cold front pushes southeastward into the CWA.
The threat for strong/severe thunderstorms appears considerably
lower with this system at this time as dynamics will be much more
limited, though a few stronger storms can't be ruled out. The
primary risk from Saturday into Sunday will be additional heavy
rainfall and flooding concerns across far north Georgia. These
areas will have already seen several inches of rain prior to the
weekend event, which could add another 1-2 inches of rainfall.

Guidance diverges by next week with respect to the evolution of
the upper low over the Southwest. The GFS maintains a southern
track shortwave along the Gulf Coast while the ECMWF lifts the low
northeastward into the Plains. At this point, kept slight chance
to low end chance PoPs on Tuesday given uncertainty. By midweek,
the next surface front approaches bringing increasing rain chances
areawide.

RW

&&

.AVIATION...
00Z Update...
TSRA could be in several rounds with initial pushing in from east
AL (tempo TS with VRB gusts near KATL for 01-05z period), then
could have redevelopment closer to front for the early morning
hours so will monitor for any tempo extension. Looks like MVFR
cigs overnight as well then improving from the north after 12/15z.
Southern sites could have more lingering showers or again some
storms Friday afternoon with stalling front. Winds initially
10-12 kts with some low end gusts possible out of SSE to SSW
(favoring SSW for KATL), then more west to NW shift 6-7 kts
behind front after 12z.

//ATL Confidence...00Z Update...
Medium on all elements.

Baker

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          63  78  57  80 /  70  40  20  50
Atlanta         61  75  60  81 /  70  30  30  40
Blairsville     55  73  49  71 /  90  20  30  80
Cartersville    57  75  55  80 /  70  20  40  60
Columbus        65  77  64  85 /  60  50  20  10
Gainesville     61  75  55  75 /  80  30  30  70
Macon           67  77  63  86 /  50  50  20  20
Rome            56  76  53  79 /  80  10  40  70
Peachtree City  62  75  59  83 /  70  40  20  30
Vidalia         68  84  66  88 /  10  30   5  10

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
Tornado Watch until 2 AM EDT Friday for the following zones:
Banks...Barrow...Bartow...Carroll...Cherokee...Clarke...
Clayton...Cobb...Coweta...Dawson...DeKalb...Douglas...Fannin...
Fayette...Forsyth...Gilmer...Gwinnett...Hall...Haralson...
Harris...Heard...Henry...Jackson...Lumpkin...Madison...
Meriwether...Newton...North Fulton...Oconee...Paulding...
Pickens...Pike...Polk...Rockdale...South Fulton...Spalding...
Troup...Union...Walton...White.

Flash Flood Watch through Friday morning for the following
zones: Bartow...Catoosa...Chattooga...Cherokee...Dade...Dawson...
Fannin...Floyd...Gilmer...Gordon...Lumpkin...Murray...Pickens...
Polk...Towns...Union...Walker...White...Whitfield.

Tornado Watch until 9 PM EDT this evening for the following
zones: Catoosa...Chattooga...Dade...Floyd...Gordon...Murray...
Walker...Whitfield.

&&

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

Hazardous Weather Outlook
National Weather Service Peachtree City GA
749 PM EDT Thu Mar 25 2021

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-261000-
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-
749 PM EDT Thu Mar 25 2021

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

.DAY ONE...Tonight...

Numerous thunderstorms are expected across north and central
Georgia through the overnight hours as a strong frontal system
moves across the area. Several storms could become severe,
especially across north and west Georgia. Primary threats include
tornadoes, damaging wind gusts, and hail.

There is also the potential for periods of heavy rain across
north Georgia, which could lead to localized flash flooding and
river flooding through the overnight hours. A Flash Flood Watch
remains in effect for north Georgia as a result.

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

Isolated to scattered thunderstorms will continue across portions
of central and eastern Georgia on Friday as the surface front
continues to push through the forecast area.

There is a chance of thunderstorms and heavy rain over portions
of north and central Georgia on Saturday and Sunday.

.SPOTTER INFORMATION STATEMENT...

Spotters activation is requested through Friday morning across
north and central Georgia. Please relay any information about
observed severe weather to the NWS while following all local,
state, and CDC guidelines.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
320 PM EDT THU MAR 25 2021

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

0245 PM     TSTM WND DMG     3 E CEDARTOWN           34.02N  85.20W
03/25/2021                   POLK               GA   DEPT OF HIGHWAYS

            THE HIGHWAY DEPARTMENT REPORTED TREES AND POWER LINES
            BLOWN DOWN AT THE POLK COUNTY MEDICAL CENTER ON ROCKMART
            HIGHWAY

&&

EVENT NUMBER FFC2100061

20

Special Weather Statement
National Weather Service Peachtree City GA
338 PM EDT Thu Mar 25 2021

GAZ014-021-022-033-252015-
Dawson GA-North Fulton GA-Cherokee GA-Forsyth GA-
338 PM EDT Thu Mar 25 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN DAWSON...NORTH FULTON...
CHEROKEE AND FORSYTH COUNTIES UNTIL 415 PM EDT...

At 337 PM EDT...a strong thunderstorm was over Holly Springs, or near
Canton...moving east at 45 mph.

  HAZARD...40 mph wind 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
Canton, Cumming, Milton, Woodstock, Sugar Hill, Holly Springs, Ball
Ground, Free Home, Buffington, Hickory Flat, Drew, Kellogg Creek,
Coal Mountain, Hightower, Matt, Lathemtown, Hobgood Park, Union Hill,
Oak Grove and Birmingham.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People outdoors should seek shelter immediately. Motorists should
slow down and be prepared for possible loss of control due to
hydroplaning.

LAT...LON 3420 8404 3418 8406 3413 8409 3408 8462
      3417 8464 3429 8450 3441 8410
TIME...MOT...LOC 1937Z 256DEG 40KT 3417 8452

WIND...40MPH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
421 PM EDT THU MAR 25 2021

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

1213 PM     TSTM WND DMG     1 SW MOUNTAINTOWN       34.75N  84.57W
03/25/2021                   GILMER             GA   PUBLIC

            APPROXIMATELY 15 TREES BLOWN DOWN OR SNAPPED ALONG
            RIDGE ROAD.

&&

EVENT NUMBER FFC2100062

NLIST

Special Weather Statement
National Weather Service Peachtree City GA
641 PM EDT Thu Mar 25 2021

GAZ002>005-011-012-252315-
Chattooga GA-Whitfield GA-Catoosa GA-Walker GA-Gordon GA-Murray GA-
641 PM EDT Thu Mar 25 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CHATTOOGA...
WHITFIELD...SOUTHEASTERN CATOOSA...SOUTHEASTERN WALKER...NORTHWESTERN
GORDON AND WESTERN MURRAY COUNTIES UNTIL 715 PM EDT...

At 640 PM EDT...a strong thunderstorm was over Naomi, or near
Lafayette...moving northeast at 50 mph.

  HAZARD...40 to 50 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, Chatsworth, Varnell, Eton, Tunnel Hill, Resaca,
Naomi, Sumac, Subligna, Suttles Mill, Rocky Face, Tilton, Mill Creek,
Beaverdale, Dawnville, Villanow, Nickelsville and North Georgia
Speedway.

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 3496 8488 3483 8474 3462 8474 3457 8506
      3459 8507 3459 8511 3456 8512 3453 8528
      3469 8532
TIME...MOT...LOC 2240Z 239DEG 45KT 3466 8521

HAIL...0.25IN
WIND...50MPH

Special Weather Statement
National Weather Service Peachtree City GA
725 PM EDT Thu Mar 25 2021

GAZ019-020-030-260000-
Polk GA-Bartow GA-Floyd GA-
725 PM EDT Thu Mar 25 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN POLK...WESTERN BARTOW
AND SOUTHEASTERN FLOYD COUNTIES UNTIL 800 PM EDT...

At 724 PM EDT...a strong thunderstorm was near Cave Spring, or 7
miles north of Cedartown...moving northeast at 55 mph.

  HAZARD...40 to 50 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
Rome, Cartersville, Cedartown, Adairsville, Euharlee, Aragon, Cave
Spring, Kingston, Taylorsville, Cassville, Lindale, Seney and
Stilesboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A tornado watch remains in effect. Continue to monitor NOAA Weather
Radio...weather.gov or other media outlets for further statements or
possible warnings on these storms.

LAT...LON 3440 8493 3433 8480 3412 8482 3399 8529
      3417 8537
TIME...MOT...LOC 2324Z 239DEG 47KT 3412 8524

HAIL...0.25IN
WIND...50MPH

Special Weather Statement
National Weather Service Peachtree City GA
832 PM EDT Thu Mar 25 2021

GAZ020-030-031-041-260100-
Polk GA-Haralson GA-Bartow GA-Paulding GA-
832 PM EDT Thu Mar 25 2021

...SIGNIFICANT WEATHER ADVISORY FOR POLK...NORTHERN HARALSON...
SOUTHWESTERN BARTOW AND PAULDING COUNTIES UNTIL 900 PM EDT...

At 832 PM EDT...a strong thunderstorm was near Cedartown...moving
east at 55 mph.

  HAZARD...40 to 50 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
Cartersville, Dallas, Cedartown, Rockmart, Euharlee, Aragon,
Braswell, Taylorsville, Yorkville, Fish Creek, Burnt Hickory Ridge,
Etna, Eubank Lake, Esom Hill, Antioch, Van Wert, Felton and
Stilesboro.

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 3409 8516 3408 8515 3408 8512 3410 8512
      3410 8505 3412 8504 3416 8490 3407 8480
      3388 8481 3378 8536 3402 8541
TIME...MOT...LOC 0032Z 255DEG 48KT 3396 8530

HAIL...0.25IN
WIND...50MPH