Severe Thunderstorm Warning 216, NWS Atlanta, GA

Area Forecast Discussion
National Weather Service Peachtree City GA
224 PM EDT Sun Jun 25 2023

...New 18Z Aviation Discussion...

.UPDATE...
Issued at 1048 AM EDT Sun Jun 25 2023

The MCS has developed over Kentucky and northern Tennessee this
morning. Hi-Res model guidance is still struggling to resolve how
the MCS will evolve throughout the day with a wide range of
potential solutions. The evolution of the complex of storms will
be closely monitored over the next few hours in order to assess
the severe threat for portions of our forecast area this afternoon
and early evening. The short term remains largely on track this
morning with only a few adjustments made to the forecast grids.

&&

.SHORT TERM...
(Today through Monday)
Issued at 327 AM EDT Sun Jun 25 2023

After a brief reprieve yesterday, the forecast looks to take a turn
back toward more active weather beginning today. The forecast area
is situated within northwest flow aloft between the Northeast trough
and the upper ridge to our west over Texas into the Arklatex region.
The primary focus will be on the potential for any impacts from an
MCS this afternoon that would progress southeastward through the day
today from convection that is only just beginning to initiate in the
Mid Mississippi Valley region. Hi-res guidance continues to support
this activity congealing into a convective complex by mid morning
and riding the periphery of the ridge toward the local area by this
afternoon.

As is often the case with a potential MCS that has not yet formed,
there remains substantial uncertainty regarding exact placement and
timing of this feature by this afternoon. In general, CAMs are in
agreement this complex will approach the region after 18Z with
varying placement solutions. Higher forecast instability to the west
across Alabama (SBCAPE over 2000 J/kg compared to 500-1000 J/kg
locally) may help focus the highest severe risk farther west. With
that said, that by no means excludes our area from potential severe
impacts from said MCS, and a number of hi-res CAMs support this
notion and bring the system across much of north Georgia through the
afternoon. The highest severe potential is generally for areas
northwest of I-85 with damaging outflow wind gusts the primary risk,
though midlevel lapse rates of 6.5-7 C/km could support a low-end
hail risk.

Any MCS should be on a weakening trend and likely largely south of
much of the area by 00Z with calmer conditions by mid to late
evening. We likely will not be done with thunderstorms, however, as
a cold front will still be approaching the area on Monday. The
degree of thunderstorm coverage and severe potential Monday will to
some extent depend on how events unfold from today into tonight.
However, instability will be higher ahead of the front Monday with
SBCAPE on the order of 2000-3000 J/kg, and mid-level lapse rates
again will be on the order of 6.5-7.5 C/km. Thus, any thunderstorms
on Monday will have the potential to become severe with a damaging
wind and potential hail threat, and a Marginal Risk for Day 2 from
SPC supports this potential.

RW

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 327 AM EDT Sun Jun 25 2023

Active northwest flow in the mid levels for the duration of the long
term forecast. Model signals for MCS development are fairly weak for
the middle of the week, but do pick up again for the weekend.
Typically, the synoptic models do struggle with timing/placement, so
will have to continue to monitor. One change in the longer term
models is that the flow remains out of the NW instead of going more
zonal during the weekend.

At the surface, a frontal boundary is still progged to drop south
Monday night into Tuesday. The airmass along and ahead of the front
will be very unstable with pretty steep mid level lapse rates. Shear
values have slightly increased across western GA for early Monday
night. There is definitely the potential for continuing severe
weather Monday night- but a lot will depend upon what happens
earlier in the day with any MCS activity.

High pressure looks to build in behind the front for the middle of
the week, with the front beginning to shift northward as a warm
front by the end of the week. Doesn't mean the forecast will be dry,
as the NW flow aloft will remain active.

Temps of 5 to 10 degrees above normal expected mid to late next
week.

NListemaa

&&

.AVIATION...
(18Z TAFS)
Issued at 211 PM EDT Sun Jun 25 2023

VFR conditions anticipated throughout this TAF cycle. TSRA
generally between 20-02Z for the metro sites with CSG timing
between 00-04Z with a complex of storms. VCSH after 06Z for
northern sites with TSRA between 08-14Z with later timing for
MCN/CSG between 12 and 18Z as a front approaches. W winds between
5 an 10KT could gust up to 25KT in storms.

//ATL Confidence...18Z Update...
Medium confidence on this evening's TSRA. Low confidence on TSRA
tomorrow morning. High confidence on all other elements.

KAL

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          69  89  69  89 /  20  50  30   0
Atlanta         70  89  70  89 /  40  50  30   0
Blairsville     63  84  61  82 /  50  40  30   0
Cartersville    68  89  67  90 /  50  50  20   0
Columbus        71  89  72  93 /  40  50  40  20
Gainesville     69  87  68  87 /  30  40  30   0
Macon           72  91  71  92 /  10  50  40  10
Rome            70  89  67  92 /  50  40  10   0
Peachtree City  69  89  68  91 /  30  50  30  10
Vidalia         74  91  73  92 /  10  50  50  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
None.
&&

SHORT TERM...KAL
LONG TERM....NListemaa
AVIATION...KAL

Hazardous Weather Outlook
National Weather Service Peachtree City GA
335 PM EDT Sun Jun 25 2023

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-261945-
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-
335 PM EDT Sun Jun 25 2023

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

.DAY ONE...This Afternoon and Tonight...

A Severe Thunderstorm Watch has been issued for portions of far
north and northwest Georgia and will remain in effect until 8 PM
EDT.

A large cluster of showers and thunderstorms is moving into far
northwest Georgia, and is expected to drop southeast across much
of north and central Georgia this afternoon into the evening
hours. At this time, the highest potential for any strong to
severe thunderstorms looks to be roughly along and west of the
Interstate 85 corridor. Frequent lightning, gusty winds and
locally heavy rainfall will be likely within any storms that occur.
The primary severe weather hazards would be damaging wind gusts
and large hail.

.DAYS TWO THROUGH SEVEN...Monday through Saturday...

Another round of thunderstorms is expected on Monday ahead of and
along a cold front. Some storms may become strong to severe,
capable of producing damaging wind gusts, frequent lightning, and
locally heavy rainfall.

Isolated thunderstorms will be possible in the afternoon and
evening Thursday and Friday, followed by scattered  through
Saturday.

Hot and humid conditions Thursday through Saturday will lead to
heat index values over 100 degrees across the majority of the
area, and over 105 degrees in portions of central Georgia. If
spending time outdoors, be sure to stay hydrated, wear lightweight
clothing, and take plenty of time to rest.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not requested but spotters are encouraged
to submit reports of severe weather through the web by going to
weather.gov/atlanta.  Please relay any information about observed
severe weather to the NWS while following all local, state, and
CDC guidelines.