Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Peachtree City Georgia
828 PM EDT Sat Oct 3 2015
no changes to the Flash Flood Watch. The possibility for
flooding or flash flooding continues overnight.
Only tweaked the probability of precipitation to put higher probability of precipitation a little farther south
over the western counties. Otherwise showers...heavy at times
for mainly north Georgia...will continue overnight.
Forecast low temperatures generally close to normal.
Previous discussion... /issued 655 PM EDT Sat Oct 3 2015/
Short term /tonight through Sunday night/...
Radar trends continue to show plume of moderate to heavy
precipitation streaming north up the eastern side of the forecast
area...and spreading west. Medium range models have backed off the
quantitative precipitation forecast totals somewhat but they are still fairly high and I do not
anticipate any big changes to my quantitative precipitation forecast grids...or to the current
watch. Medium range and high-res models still indicating that the
general north/south axis of precipitation will rotate
counterclockwise becoming more northwest/southeast or even west/east
oriented through the evening and the overnight period. Will have a
fairly decent gradient in the pop grid from southwest to north. The
upper low is still expected to slowly shift east through Sunday with
the axis of heavier precipitation shifting east Sunday as well.
Long term /Monday through Saturday/...
Aside from a few minor updates to probability of precipitation on Monday into Tuesday...no
major changes were made to the long term. There will still be
the chance for lingering showers on Monday for eastern Georgia as
the upper low continues to pull some moisture into the area. The
region will finally start to dry out in earnest next week as the
closed low pushes offshore with dry and temperate conditions for
several days. Models diverge significantly by next weekend with the
evolution of the upper low over the southwest U.S. And any
potential impact for our area.
Previous long term /Sunday night through Friday/...
Models in fair agreement on closed upper low circulating vicinity
of southeast Georgia or just off shore at the start of the period.
Easterly flow and a connection to Joaquin still evident...but the
bulk of the heavier rain still looks like it will be across the
Carolinas Sunday night. Likely probability of precipitation look okay Sunday night for the
far northeast with lower probability of precipitation elsewhere. Upper low pulling to the
northeast Monday and Monday night should diminish rain chances for
the forecast area. Upper ridge expected to build across the
southeast Tuesday through the end of the week. Have continued
with dry weather during that time.
IFR-MVFR ceilings and IFR-VFR and highly variable visibilities expected
at the taf sites through tonight. Increasing moderate to heavy
showers over the north and east. Isolated thunderstorms possible. Surface
winds out of the northwest-NE at 6-12 kts with gusts 15-20kts overnight.
And Sunday. Slightly higher at atl Sunday.
//Atl confidence...00z update...
low confidence for visibilities and duration of showers.
Medium confidence for ceilings and wind direction.
High confidence for wind speeds.
Preliminary point temps/pops...
Athens 59 67 60 69 / 100 90 70 30
Atlanta 58 69 61 71 / 80 80 40 20
Blairsville 59 70 58 71 / 100 80 40 20
Cartersville 58 72 61 73 / 90 80 30 10
Columbus 58 71 62 72 / 60 50 40 10
Gainesville 58 68 60 69 / 100 90 50 20
Macon 57 70 63 71 / 60 60 50 20
Rome 59 74 60 75 / 90 70 30 10
Peachtree City 58 68 61 71 / 80 70 40 10
Vidalia 60 72 62 72 / 50 50 30 30
Flash Flood Watch through Sunday evening for the following