Tornadoes and Flash Flooding in Georgia, January 13 to 14, 2020

Area Forecast Discussion
National Weather Service Peachtree City GA
651 AM EST Mon Jan 13 2020

.UPDATE...

Updated for the 12Z Aviation Discussion.

&&

.PREV DISCUSSION... /Issued 425 AM EST Mon Jan 13 2020/

SHORT TERM /Today through Tuesday/...

The short term period begins with the warm front moving slowly
northward across the forecast area. Current radar shows a line of
showers and thunderstorms extending along an axis along and south of
the I-85 corridor along the leading edge of the frontal boundary.
Thunderstorms within this line are not severe, but are nonetheless
capable of producing locally heavy rainfall. The front, along with
the showers and thunderstorms, will continue to slowly advance into
north Georgia during the morning hours. Low clouds and reduced
visibilities have furthermore developed in the areas behind and
south of the warm front. Widespread fog is in place across portions
of central Georgia, with some locations in the far southern tier of
the forecast area experiencing dense fog with visibilities reduced
to a quarter mile or less. As a result, a Dense Fog Advisory is in
effect for those areas until 9 AM EST this morning.

Persistent southwesterly flow aloft remains in place over the
southeastern CONUS, keeping a warm, moist airmass over the region
and  contributing to dewpoint values in the low to mid 60s across
most of north and central Georgia, and precipitable water values
between 1.2" and 1.6". Later during the day today, the warm front
will stall and become stationary across north Georgia, remaining
draped across the area into Tuesday. Likely to categorical PoPs are
expected ahead of the warm front, primarily across north Georgia
through today and Tuesday, with progressively diminishing PoPs
behind the front. Deep moisture and high dewpoints as a result of
the southwesterly flow aloft remaining over the southeastern CONUS
will allow for sufficient instability to warrant isolated to
scattered thunderstorms where showers occur.

Due to the continued warm and moist flow from the Gulf, temperatures
will be well above climatological normals through the short term
period. Low temperatures this morning are expected to range from the
low 50s in far north Georgia to the low 60s in east-central Georgia.
These temperatures are 20-28 degrees higher than the daily average
across most of the forecast area. High temperatures today and
Tuesday will range from the upper 60s in north Georgia to the upper
70s in east central Georgia, between 16-24 degrees above average
area-wide.

King

LONG TERM /Tuesday Night through Sunday/...

Will be short and sweet here with the long term discussion given
the ongoing overnight convection across the area. The long term
period begins with a continued southern stream jet connection to
the Pacific that will bring a great deal of moisture to the area
for most of the week. Extended models in good agreement in high
levels of deep layer moisture along with occasional shortwaves in
zonal flow aloft temporarily increase rain chances.

The best chances for rain will be Tue through early Thu with main
precip axis meandering north and south through the forecast area.
Enough instability present to warrant mainly isolated thunder
chances through this period. Given antecedent conditions,
certainly could be looking at additional flooding given persistent
axis and possibility of training across the area.

High bridging across the northern tier will shunt precip south of
the area for Friday but yet another shortwave will bring another
shot of precip ahead of a front to the area for Saturday.

Deese

&&

.AVIATION...
12Z Update...
SHRA/TSRA continues to advance northward through the forecast area
as the period begin, are ongoing around all TAF sites, and
expected to continue throughout the day. IFR/LIFR ceilings and
visibility restrictions are solidly in place across CSG/MCN and
IFR conditions have arrived at the ATL metro sites and AHN. These
IFR conditions are expected to remain throughout the remainder of
the TAF period, with the exception of ceilings improving to MVFR
at CSG/MCN late this afternoon by 20-22Z. Winds will remain light
through the period, at mainly 7 kts or less. Light and variable
winds to start the period will become SE this afternoon by 18Z
before shifting to S to SW early Tuesday morning by 09-11Z.

//ATL Confidence...12Z Update...
Medium confidence on all elements.

King

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          69  61  72  62 /  90  70  60  60
Atlanta         68  62  70  63 /  90  70  70  50
Blairsville     65  56  66  58 /  80  90  90  60
Cartersville    67  60  70  61 /  80  80  80  60
Columbus        75  63  74  64 /  60  40  50  30
Gainesville     66  60  69  62 /  80  80  80  60
Macon           77  61  74  63 /  40  40  40  30
Rome            66  59  70  61 /  80  90  80  60
Peachtree City  70  62  72  62 /  80  60  70  50
Vidalia         79  63  78  62 /  40  30  20  20

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 9 AM EST this morning for the following
zones: Bleckley...Chattahoochee...Crisp...Dodge...Dooly...
Emanuel...Houston...Johnson...Laurens...Macon...Marion...
Montgomery...Pulaski...Schley...Stewart...Sumter...Telfair...
Toombs...Treutlen...Webster...Wheeler...Wilcox.

&&

SHORT TERM...King
LONG TERM....Deese
AVIATION...King

Hazardous Weather Outlook
National Weather Service Peachtree City GA
542 AM EST Mon Jan 13 2020

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-141045-
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-
542 AM EST Mon Jan 13 2020

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

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

Showers and a few thunderstorms are expected across portions of
the area as a warm front lifts northward over north and central
Georgia. Any thunderstorms that develop should remain below severe
limits.

Also, widespread dense fog will be present through the morning for
portions of Central GA. Precautions should be taken in areas of
reduced visibilities.

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

Showers and thunderstorms will persist into Saturday as a frontal
boundary remains stalled over north Georgia. Heavy rainfall could
again lead to flooding concerns as soils will already be
saturated.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

Special Weather Statement
National Weather Service Peachtree City GA
151 AM EST Mon Jan 13 2020

GAZ038-039-050-051-130730-
Taliaferro GA-Wilkes GA-Oglethorpe GA-Greene GA-
151 AM EST Mon Jan 13 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN TALIAFERRO...WILKES...
SOUTHEASTERN OGLETHORPE AND NORTHEASTERN GREENE COUNTIES UNTIL 230 AM
EST...

At 151 AM EST...a strong thunderstorm was over Siloam, or near
Greensboro...moving northeast at 40 mph.

  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
Washington, Greensboro, Crawfordville, Union Point, Tignall,
Woodville, White Plains, Siloam, Rayle, Delhi, Newtown, Danburg,
Lyneville, Carters Grove, Ficklin, Lundberg, Robinson, Metasville,
Daniel Springs and Floral Hill.

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 3345 8309 3360 8321 3397 8264 3386 8261
      3387 8258 3387 8257 3384 8258 3383 8260
      3371 8253
TIME...MOT...LOC 0651Z 236DEG 35KT 3357 8308

WIND...40MPH

Special Weather Statement
National Weather Service Peachtree City GA
521 AM EST Mon Jan 13 2020

GAZ068>071-079>081-131100-
Lamar GA-Monroe GA-Taylor GA-Upson GA-Crawford GA-Talbot GA-Pike GA-
521 AM EST Mon Jan 13 2020

...SIGNIFICANT WEATHER ADVISORY FOR LAMAR...SOUTHWESTERN MONROE...
NORTHWESTERN TAYLOR...UPSON...NORTHWESTERN CRAWFORD...EASTERN TALBOT
AND SOUTHEASTERN PIKE COUNTIES UNTIL 600 AM EST...

At 521 AM EST...a strong thunderstorm was over Prattsburg, or 8 miles
northeast of Talbotton...moving northeast at 30 mph.

  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
Thomaston, Barnesville, Roberta, Milner, Yatesville, Junction City,
Culloden, Aldora, Sunset Village, Lincoln Park, The Rock,
Russellville, Howard, Logtown, Salem, Prattsburg, Hannahs Mill, Big
Lazer Creek Wma, Wesley Church and Fickling Mill.

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 3256 8445 3256 8449 3277 8452 3317 8416
      3276 8390 3253 8445
TIME...MOT...LOC 1021Z 245DEG 24KT 3273 8440

WIND...40MPH