Special Weather Statement, NWS Atlanta, GA

Area Forecast Discussion...UPDATED
National Weather Service Peachtree City GA
741 PM EDT Sat Apr 14 2018

.UPDATE...
For 00z TAFs/Aviation. See discussion below.

&&

.PREV DISCUSSION... /Issued 300 PM EDT Sat Apr 14 2018/

SHORT TERM /Rest of today through Sunday Night/...

Main focus on strong/severe convective threat as broad swath of
precip and leading edge of storms slowly propagates eastward
(currently across the western half of AL). Models continue to
indicate that available CAPE will be on the decrease by the time
it reaches the far western tier of the CWA after about 05z tonight
though will need to watch for any bowing segments getting more
outflow driven ahead that could raise chances in the west earlier
this evening. Hi-res solutions are in fairly good consensus on
some waves of enhanced line development pushing NE close to the
state line earlier, but all mostly lose their punch by the time
the main frontal forcing takes over after midnight. SPC still has
some Marginal risk in the western tier though Slight risk is right
along the state border. Thinking main strong/severe chances will
be late tonight until about 3-4 AM for the NW and west central
portion, then ramp up again mid-morning into afternoon for the
rest of the area Sunday. Low and upper level bulk shear is
supportive for damaging wind threats along any bowing segments and
the low level helicity also supportive of a few brief spin up
tornadoes along any leading edge. Have included greater mention of
isolated flooding given the mean flow orientation and rather
broad moisture swath.

Behind the front, we will have abnormally cold temps advecting in
and will need to monitor some light rain to snow/flurry
transition possible early Monday in the far NE mtns. Thermal
profiles indicate very shallow saturation layer so not expecting
accumulations. Also will likely have some freeze/frost concerns
that forecast updates may need to include a Freeze Watch for on
Monday morning.

Baker

LONG TERM /Monday through Saturday/...

Showers and thunderstorms will exit the area to begin the extended
period as the storm system moves off to the east. Model guidance is
continuing to become more consistent regarding the timing of this
system and the majority of the activity will clear the area by
Sunday evening. At the same time, colder air will build into the
area behind the front as it exits the region. The possibility exists
for some showers to wrap around the back end of the system which
could ultimately lead to low-end PoPs in far north GA. Right now, it
appears that any precipitation that occurs will be confined to the
mountains in the far northeast. These low precipitation chances in
the wrap around coupled with a brief period of sub-freezing
temperatures in northeast GA could lead to the possibility of mixed
precipitation followed by some light snow flurries in the early
morning hours on Monday morning. It is a possibility that the
precipitation could end before temperatures drop below freezing,
though.

Behind the front, high pressure will build into the area which will
promote quieter conditions on Monday and Tuesday. Temperatures will
similarly be colder than average at this time with highs in the 50s
and low 60s on Monday afternoon and lows mainly in in the 30s and
low 40s throughout the area Monday night. Some frost is possible
across the northern tier Monday night depending on the extend to
which the winds calm in the area. Surface winds will regain a
southerly component by late Tuesday and temperatures will quickly
warm once again into the mid 70s by Tuesday afternoon. The next
system will approach the area late Wednesday and early Thursday,
however, the moisture and instability associated with this system
appear to be limited based on GFS and ECMWF guidance. Will maintain
low-end chance PoPs at this time.

King

&&

.AVIATION...
00Z Update...
Pre-frontal convective band stretching from NW Georgia to SE
Mississippi continues to move slowly east. Not expecting much in
the way of acceleration overnight as convection awaits push from
upr lvl trough. Timing of initial band of heavy showers/storms
reaching western TAF sites (incl ATL) looks to be btwn 08-10z
overnight. This will likely be where the highest wind gusts occur,
potentially 40-45kts given low lvl wind fields. Lcly heavy
rainfall could drop vsby briefly down < 1SM but kept MVFR cigs and
vsby until after initial line moves through. Several hours of
light to moderate rain w/ isold embedded TS possible will follow
through 15-16z (little later at KAHN and KCN), then conditions
should gradually improve through afternoon. Winds will kick up
from the WSW, especially late in the day and into evening hours.

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

DJN.83

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          65  68  39  59 /  60  90  20   0
Atlanta         64  66  38  58 /  80 100  10   0
Blairsville     60  63  32  51 /  80  90  20  10
Cartersville    59  64  37  56 /  90 100  10   5
Columbus        62  66  41  64 / 100 100   5   0
Gainesville     64  65  37  55 /  70  90  20   5
Macon           67  70  41  64 /  60  90  20   0
Rome            55  60  36  56 /  90  90  10   5
Peachtree City  63  66  38  60 /  80 100  10   0
Vidalia         67  77  43  65 /  20 100  40   0

&&

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

SHORT TERM...DJN.83
AVIATION...DJN.83

Hazardous Weather Outlook...Updated
National Weather Service Peachtree City GA
825 PM EDT Sat Apr 14 2018

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-151915-
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-
825 PM EDT Sat Apr 14 2018

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

.DAY ONE...Tonight...

Showers and thunderstorms will increase in coverage this evening
across west-central and northwest Georgia, gradually moving east
across the area overnight into Sunday morning. A few storms could be
strong to severe, mainly west of I-75, with the primary threats
being damaging winds between 40 and 60 MPH, and locally heavy rain.
A brief tornado is not out of the question but that threat is very
low at this time.

The persistent rainfall overnight into Sunday morning could lead to
isolated flooding, especially in poor drainage, urban and low lying
areas. Many areas could see up to 1 inch rainfall, with locally
higher amounts to 2 or more inches possible.

.DAYS TWO THROUGH SEVEN...Sunday through Friday...

Showers and thunderstorms will continue to move across north and
central Georgia during the morning hours. East of an Athens to Macon
line, some of the storms could become strong to severe during the
early afternoon, capable of producing damaging winds and even a
brief tornado. Locally heavy rainfall will also elevate the flood
threat.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not anticipated but spotters are encouraged to
report any damage or significant weather through the early morning
hours Sunday.

DJN

Special Weather Statement
National Weather Service Peachtree City GA
642 PM EDT SAT APR 14 2018

GAZ001-002-004-011-142330-
Chattooga GA-Whitfield GA-Walker GA-Dade GA-
642 PM EDT SAT APR 14 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CHATTOOGA...WESTERN
WHITFIELD...WALKER AND DADE COUNTIES UNTIL 730 PM EDT...

At 641 PM EDT...a line of strong thunderstorms was along a line
extending from near Henagar to near Desoto State Park to New Moon...
and moving northeast at 40 mph.

  HAZARD...40 to 50 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 these storms include
Lafayette, Summerville, Trenton, Fort Oglethorpe, Rossville,
Chickamauga, Trion, Lookout Mountain, Menlo, Center Post, Fairview,
Linwood, Villanow, Cloudland, Chattanooga  Valley, Cloudland Canyon
State Park, Hooker, Cooper Heights, Rock Spring and Naomi.

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 3486 8526 3486 8520 3478 8520 3478 8516
      3477 8515 3477 8514 3482 8513 3471 8505
      3438 8548 3488 8559 3498 8551 3499 8526
TIME...MOT...LOC 2241Z 215DEG 34KT 3460 8570 3448 8561 3439 8554

WIND...50MPH

Special Weather Statement
National Weather Service Peachtree City GA
829 PM EDT SAT APR 14 2018

GAZ011-019-030-041-150115-
Chattooga GA-Polk GA-Haralson GA-Floyd GA-
829 PM EDT SAT APR 14 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN CHATTOOGA...POLK...
NORTHWESTERN HARALSON AND FLOYD COUNTIES UNTIL 915 PM EDT...

At 829 PM EDT...a line of strong thunderstorms was along a line
extending from Western Weiss Lake to near Forney to near Borden
Springs...and moving northeast at 35 mph.

  HAZARD...40 to 50 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 these storms include
Rome, Cedartown, Summerville, Cave Spring, Lyerly, Fish Creek, Etna,
Lindale, Esom Hill, Antioch, Seney, Felton, Coosa, Chattoogaville,
James H. Floyd State Park and Holland.

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 3446 8536 3421 8509 3391 8511 3381 8537
      3437 8548
TIME...MOT...LOC 0029Z 231DEG 32KT 3420 8567 3406 8551 3390 8553

WIND...50MPH

Special Weather Statement
National Weather Service Peachtree City GA
902 PM EDT SAT APR 14 2018

GAZ030-041-150115-
Polk GA-Haralson GA-
902 PM EDT SAT APR 14 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN POLK AND HARALSON
COUNTIES UNTIL 915 PM EDT...

At 902 PM EDT...a strong thunderstorm was near Tallapoosa, or 7 miles
west of Buchanan...moving northeast at 50 mph.

  HAZARD...40 to 50 mph wind...up to penny sized hail...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
Buchanan, Tallapoosa and Eubank Lake.

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 3391 8511 3395 8510 3395 8505 3385 8504
      3370 8534 3371 8535 3381 8537
TIME...MOT...LOC 0102Z 229DEG 42KT 3379 8532

HAIL...0.75IN
WIND...50MPH