Special Weather Statement, NWS Atlanta, GA

Area Forecast Discussion
National Weather Service Peachtree City GA
1142 AM EDT Fri Jun 1 2018

.UPDATE...

Main update was to increase the pop trend the afternoon into
evening across north GA into northern portions of central GA as
the hi-res solutions are getting into more consensus with the
evolution of a quasi-linear mode of strong to severe storms. Still
looking to have the added extra upper level forcing given the
influence of a higher amplitude shortwave in conjunction with a
developing complex currently across north AL and a lingering
remnant outflow boundary draped across north GA. Mid level lapse
rates should steepen some more by afternoon along with SB CAPEs
increasing to near 3000 J/kg or higher. Have added mention of
some severe potential with damaging winds, large hail, and heavy
rainfall threats to the grids. This should match up decently with
the Slight and newly upgraded Enhanced Risk issued by SPC. Storm
coverage should become fairly widespread across north GA by 4 to 6
PM. Previous discussion follows...

Baker

&&

.PREV DISCUSSION... /Issued 748 AM EDT Fri Jun 1 2018/

SHORT TERM /Today through Saturday/...

At the surface high pressure remains off the SE coast with mid level
ridging moving offshore.  A trough will swing from the Great Lakes
region today toward New England.  The southern leg of this trough
has already started to be felt across portions of GA with NW flow
bring down a fairly potent MCS late last night/early this morning
through north.  This complex has since weakened into scattered
thunderstorms moving through east GA. Expect weakening to continue
as the cluster of storms moves south.

Meanwhile, another MCS is moving through west/central TN and will
continue its ESE trajectory through the next several hours. We will
have to monitor this complex carefully.  Doing a time-of-arrival,
these showers/thunderstorms could arrive in our NW tier around 10Z.
One of the main questions is...will this system hold itself
together? It looks as if instability will start to wane as it nears
east TN and north GA. Not to mention these storms may move out ahead
of upper level support. Think we will see activity moving into north
GA early this morning, but the complex may dwindle by that point.
That would mean the remaining boundary would be the axis by which we
observe the potential for afternoon/evening thunderstorms to develop
and move south and east, possibly lasting through the overnight. It
truly depends on the timing and intensity of the vortmax/impulses
that come down with the trough. If the right ingredients are in
place, we could see another MCS develop. A lot of uncertainty with
the timing and location of thunderstorm activity today/tonight, but
under NW flow, instability at the surface and plenty of upper level
support from the trough moving through, it is not a question of if
but when and where.

With steep lapse rates, strong updrafts are expected with some hail.
Shear may be limited, but with precip loading and storm orientation,
damaging winds are possible.  Training of storms is also a potential
but largely depends on the orientation of the boundary with
directional propagation an important factor.

Depending on the location and the timing of showers/thunderstorms,
this could still be ongoing tonight.  But anticipate to see things
diminish by Saturday morning as the trough continues to push toward
the east coast. A lingering boundary may help produce
showers/thunderstorms during the afternoon, mainly across central
GA.

Temperatures will be above normal through the short term.

26

&&

.LONG TERM /Saturday Night through Thursday/...

Long term period begins with area on the back side of departing
shortwave moving through the Carolinas taking the bulk of the
significant precip with it. This respite will be very temporary
however as yet another strong shortwave approached the area for
Sunday. As we have seen the past few days, these impulses are very
difficult to forecast timing wise and cold pools can significantly
alter the model projections of what should occur. That said, this
one certainly looks potent with strong DPVA and instability
that features GFS CAPE over 4500 J/KG coming into the Columbus
area by afternoon. Temps aloft not quite as cold as we have seen
but sufficient to allow for severe storms and large hail and
damaging winds.

Well something we are not used to is in store for early next week,
a drying period. Deep layer drying with precipitable water
dropping to around a half an inch for Mon afternoon. Some recovery
into Tue but still less than an inch allowing for a continued
mostly dry forecast.

Another impulse on the west side of GA and increased moisture will
increase pops for Wed. This will be especially true for portions
of Central GA during the afternoon hours. In between shortwaves on
Thu will mean lessening rain chances once again but Friday could
be quite active as NW flow train keeps on rolling with impulses
enhancing activity as we close the extended period.

Deese

&&

.AVIATION...
12Z Update...
SCT to BKN cigs across the NW tier of GA with IFR cigs across far
west GA. Cigs may end up lowering across the ATL TAF sites as a
line of showers/thunderstorms continue to move into NW GA this
morning. Current thinking is that this line will continue to
diminish through the next couple hours with lingering showers
moving into ATL by mid/late morning. Thunderstorm activity will
likely develop again this afternoon/evening. Some of this
precipitation may last through the overnight with ceilings
lifting shortly thereafter. Westerly winds are expected through
the TAF period. Given more rain is anticipated through the
day/evening, fog/stratus may be an issues for area TAF sites
Saturday morning.

//ATL Confidence...12Z Update...
Low on timing of thunderstorm activity.
Medium on morning ceilings.
High confidence on other elements.

26

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          90  70  90  71 /  60  60  30  30
Atlanta         88  71  89  73 /  60  60  40  30
Blairsville     83  64  84  64 /  60  50  30  20
Cartersville    88  69  89  69 /  60  50  30  20
Columbus        90  73  91  74 /  40  40  40  30
Gainesville     87  70  88  70 /  60  50  30  30
Macon           91  72  91  72 /  40  50  40  40
Rome            88  69  90  70 /  60  40  30  20
Peachtree City  89  70  90  71 /  60  60  40  30
Vidalia         92  74  91  73 /  40  40  50  50

&&

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

SHORT TERM...26/Baker
LONG TERM....Deese
AVIATION...26

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1139 AM EDT FRI JUN 01 2018

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

0500 PM     FLASH FLOOD      HELEN                   34.70N  83.74W
05/31/2018                   WHITE              GA   LOCAL OFFICIAL

            MULTIPLE REPORTS OF FLOODING IN THE CITY OF HELEN
            INCLUDING ALONG THE MAIN STREET AND NEAR THE WATER PARK.

&&

EVENT NUMBER FFC1800174

LREAVES

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Special Weather Statement
National Weather Service Peachtree City GA
151 PM EDT FRI JUN 1 2018

GAZ002-004-005-011-012-019-011815-
Chattooga GA-Whitfield GA-Walker GA-Gordon GA-Murray GA-Floyd GA-
151 PM EDT FRI JUN 1 2018

...SIGNIFICANT WEATHER ADVISORY FOR CHATTOOGA...SOUTHERN WHITFIELD...
SOUTHEASTERN WALKER...WESTERN GORDON...WESTERN MURRAY AND
NORTHEASTERN FLOYD COUNTIES UNTIL 215 PM EDT...

At 151 PM EDT...a strong thunderstorm was over Naomi, or near
Lafayette...moving east at 35 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
Rome, Dalton, Calhoun, Lafayette, Summerville, Trion, Resaca,
Plainville, Shannon, Lyerly, Center Post, Pinson, Subligna, Lake
Marvin, Linwood, Villanow, James H. Floyd State Park, Naomi,
Oostanaula and Suttles 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 3475 8540 3477 8522 3477 8514 3480 8486
      3438 8499 3439 8499 3439 8501 3435 8501
      3435 8502 3431 8502 3439 8546
TIME...MOT...LOC 1751Z 274DEG 29KT 3466 8522

WIND...40MPH

Special Weather Statement
National Weather Service Peachtree City GA
155 PM EDT FRI JUN 1 2018

GAZ031>034-042>045-011830-
De Kalb GA-North Fulton GA-Douglas GA-Cobb GA-Carroll GA-Gwinnett GA-
Paulding GA-South Fulton GA-
155 PM EDT FRI JUN 1 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN DE KALB...NORTH
FULTON...DOUGLAS...COBB...EASTERN CARROLL...WESTERN GWINNETT...
SOUTHEASTERN PAULDING AND SOUTH FULTON COUNTIES UNTIL 230 PM EDT...

At 154 PM EDT...a line of strong thunderstorms was along a line
extending from Dunwoody to near Abilene...and 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 these storms include
Atlanta, Marietta, Douglasville, Carrollton, Decatur, Sandy Springs,
Roswell, Smyrna, Dunwoody, East Point, Union City, Villa Rica,
College Park, Powder Springs, Fairburn, Lilburn, Chamblee, Norcross,
Doraville and Clarkston.

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 3372 8505 3405 8436 3393 8404 3351 8469
      3351 8485 3349 8486 3348 8489 3366 8519
TIME...MOT...LOC 1754Z 277DEG 13KT 3396 8431 3363 8501

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

Special Weather Statement
National Weather Service Peachtree City GA
216 PM EDT FRI JUN 1 2018

GAZ002-004-005-011-012-019-020-030-011845-
Chattooga GA-Whitfield GA-Polk GA-Walker GA-Gordon GA-Bartow GA-
Murray GA-Floyd GA-
216 PM EDT FRI JUN 1 2018

...SIGNIFICANT WEATHER ADVISORY FOR CHATTOOGA...SOUTHEASTERN
WHITFIELD...WESTERN POLK...SOUTHERN WALKER...GORDON...NORTHWESTERN
BARTOW...SOUTHERN MURRAY AND FLOYD COUNTIES UNTIL 245 PM EDT...

At 215 PM EDT...a line of strong thunderstorms was along a line
extending from Tilton to near Ball Flat...and moving east at 25 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 these storms include
Rome, Dalton, Calhoun, Cedartown, Summerville, Chatsworth,
Adairsville, Trion, Cave Spring, Resaca, Plainville, Shannon, Lyerly,
Menlo, Center Post, Pinson, Subligna, Esom Hill, Redbud and Lake
Marvin.

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 3466 8550 3477 8464 3473 8466 3459 8465
      3390 8538 3462 8554
TIME...MOT...LOC 1815Z 264DEG 21KT 3467 8495 3400 8571

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