Area Forecast Discussion
Issued by NWS Atlanta, GA
FXUS62 KFFC 281711 AAB
Area Forecast Discussion...UPDATED
National Weather Service Peachtree City GA
111 PM EDT Wed Sep 28 2016
For 18z TAFs/Aviation.
.PREV DISCUSSION... /Issued 714 AM EDT WED SEP 28 2016/
SHORT TERM /Today through Thursday/...The current satellite loop
shows some mid to high level clouds associated with the main
frontal boundary moving slowly south across the region. The front
has finally made it through the ATL area and is located along a
CSG to GVL line. This front will continue moving south and should
be south of MCN by 20z and exit our CWA by 06z Thu. A much drier
airmass will move in across the region behind this front beginning
today. There is second much weaker and drier front that rotates
through the state around the main parent low tonight and thu
morning. This second front will bring in a cooler airmass with low
temps expected Thu morning in the 50s and 60s and highs in the 70s
LONG TERM /Thursday Night through Tuesday/...
The long term period begins with strong closed upper low
continuing its slow trek southward into the Tennessee Valley.
Embedded shortwaves will rotate around the base of this trough but
moisture remains limited. Could certainly envision a few showers
developing on friday but chances still appear too low for
inclusion in the forecast at this time.
Main story for the initial portion of the extended will be the
beginning of fall like weather across the area. Both highs and
lows on Friday look to be some 3 to 5 degrees below climo which
will seem cooler given we have been close to 10 degrees above for
quite a while now. Highs will recover very quickly through the
weekend with a return to the 80s and above normal for the atlanta
metro. Lows will be slower to moderate and look for continued near
climo conditions with values in the lower to mid 50s.
Much uncertainty exists as we get to the tail end of the extended
period. GFS and ECMWF continue to differ on evolution of tropical
system with GFS curving quickly but the Euro remaining slower and
further south and west. Will just need to wait until models come
into better agreement but regardless...looks like there will be
enough return flow from the atlantic to warrant low pops for SE
sections early next week.
Dry air will be spreading into the CWA today. This will allow
humidities to drop to near 25 percent for an hour or two this afternoon
across northwest Georgia. Fuels at this time are running around 10
percent. However time requirements will not be met for a Fire
Danger Statement. This will continue to be watched.
With cold front now from about an Athens (KAHN) to Columbus (KCSG)
line and continuing to move south/east, drier air has finally
invaded north and parts of central GA! VFR conditions will prevail
at KATL and surrounding airfields. Deeper cumulus field around
KMCN where low level moisture will linger for a few more hours
could yield a passing -SHRA this aftn. Could see some patchy
ground fog around KAHN late tonight but drier air should limit
this potential, so have left lower VSBY/CIGS out of TAF for now. A
few gusts 15-18KTS around KATL possible this afternoon, but better
potential tomorrow to gusty winds within stronger/gradient NW
//ATL Confidence...18Z Update...
High confidence all elements.
.PRELIMINARY POINT TEMPS/POPS...
Athens 85 58 80 52 / 10 5 5 5
Atlanta 84 60 75 54 / 5 0 5 5
Blairsville 78 51 69 46 / 0 5 10 5
Cartersville 83 55 74 50 / 0 5 5 5
Columbus 89 62 82 56 / 10 5 5 5
Gainesville 82 58 75 52 / 5 5 5 5
Macon 89 60 84 53 / 20 20 5 5
Rome 83 54 74 50 / 0 5 5 10
Peachtree City 85 56 77 50 / 5 0 5 5
Vidalia 89 67 85 59 / 40 30 10 5