982
FXUS62 KFFC 041112
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
712 AM EDT Thu Jul 4 2024


...New 12Z Aviation Discussion...

.SHORT TERM...
(Today through Friday)
Issued at 435 AM EDT Thu Jul 4 2024

At a glance:

  - Hot temperatures with a Heat Advisory for much of the area
    today. Heat will likely continue through Friday.

  - Increasing chances of showers and storms, particularly on
    Friday.

An upper ridge of high pressure will remain anchored over the area
today. The ridge position will shift a bit S for Friday as a weak
trough moves into the W Great Lakes and upper MS Valley. At the
surface, high pressure will weaken a bit today. A cold front will
approach the area from the NW on Friday with increasing shower and
thunderstorm chances.

For today, scattered showers and thunderstorms are expected
generally from near and W of the Atlanta metro area S to Columbus and
Macon. For Friday, shower and thunderstorm chances will increase
from the NW ahead of the approaching front. The best chances will be
from the Atlanta metro area NW. Organized severe weather is not
expected. However, isolated strong storms are possible this
afternoon, with precipitationDue to the upcoming holiday, have gone
ahead and hoisted an advisory for all areas save the NE. loading
producing gusty winds in the strongest storms. On Friday, increased
instability, a slight uptick in effective shear, and increasing
frontal convergence may bring a slight increase in the likelihood of
strong storms to the NW. Very light low and mid- level winds will
lead to slow storm motion today. As a result, isolated heavier
rainfall totals are certainly possible.

The big story will continue to be hot temperatures. High
temperatures today will be in the lower to upper 90s across most of
the area except the NE corner. These temperatures will couple with
dew points in the mid 70s to produce heat indices as high as 109 this
afternoon. The warmest temperatures are expected over the E half and
NW corner of the area. The highest dew points during this time
period are expected across the SW portion of the area as southerly
flow continues to tap into Gulf of Mexico moisture. The different
areas of max temperatures and dew points will lead to rather variable
heat index values, but many areas are expected to reach low end Heat
Advisory criteria. Heat indices are forecast to increase a bit for
Friday. However, there is some uncertainty regarding increasing rain
chances and associated cloud cover. As a result, will defer to the
day shift regarding any possible extension of the Heat Advisory. /SEC

&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 435 AM EDT Thu Jul 4 2024

Looking at a break down of the 500 mb ridging over our area as the
high pressure shifts eastward and a trough begins to deepen into the
mid MS valley into Friday. As this trough moves further eastward and
the associated surface low moves into the Ohio valley, a cold front
looks to move into the Tennessee Valley by Friday increasing rain
chances over north Georgia Friday into Saturday. The long term begins
in the middle of that transition as the front looks to be solidly
over central Georgia Saturday into Sunday as it slowly sinks
southward. This is shown in the increased rain chances through the
weekend. Models are indicating PWATs at 2"+ over the area into the
weekend, so again any storms will likely be efficient rainfall
producers and we`ll have to keep an eye on the flooding potential
although rainfall amounts are limited at this time. CAPE values
~1500-2500 J/KG are currently showing up in the ensembles, so
thunderstorms will definitely be a risk as well through the weekend.

Towards the beginning to middle of next week, things are a little
uncertain when it comes to rainfall potential. The troughing does
look to stay solidly in place though over the central US with the
high pressure of to our east. With this pattern and the increased
moisture being brought in with southwesterly winds, have kept
increased PoPs through the middle of the week. This increased
moisture is also the reasoning behind the increased heat indices
through the long term. Currently looking at heat indices from 100-
107 through the long term, although increased rainfall may help
reduce those values.

Temps are forecast to be in the mid to upper 90s through the weekend
and with the moist airmass (dewpoints in the mid 70s), heat indices
will need to be monitored for potential heat advisories for the July
4th weekend.

Hernandez

&&

.AVIATION...
(12Z TAFS)
Issued at 710 AM EDT Thu Jul 4 2024

Some IFR cigs have made it into the S Atlanta metro area, but these
should be short-lived. Light and variable winds will be mostly light
SSW today. Have included TEMPO thunderstorms at MCN, CSG, and most
Atlanta metro sites this afternoon. Have tried to pin down the
timing in the Atlanta area to just a couple of hours since PoPs are
only 20-30%.

//ATL Confidence...12Z Update...
Medium confidence on thunderstorm timing and morning cigs, high on
other elements.

SEC

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          76  95  74  94 /  10  60  40  60
Atlanta         77  94  75  93 /  10  80  50  60
Blairsville     71  88  70  87 /  20  80  60  50
Cartersville    76  94  73  92 /  10  80  60  50
Columbus        77  96  76  94 /  20  70  40  80
Gainesville     76  93  75  92 /  10  70  50  60
Macon           76  96  75  95 /  10  60  30  70
Rome            76  94  75  93 /  20  80  60  40
Peachtree City  75  94  73  92 /  10  70  50  60
Vidalia         75  97  76  95 /  10  40  20  70

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM this afternoon to 7 PM EDT this evening
for GAZ001>005-011-012-019>021-024-025-027-030>039-041>062-
066>076-078>086-089>098-102>113.

&&

$$

SHORT TERM...SEC
LONG TERM....Hernandez
AVIATION...SEC