Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Peachtree City Georgia
748 PM EDT Wednesday Jul 30 2014
Previous discussion... /issued 347 PM EDT Wednesday Jul 30 2014/
Short term /tonight through Thursday night/...
a gradual shift from the pleasant weather is expected by the end of
the short term period. The combination of a transitioning long wave
trough over the East Coast and the weakening of the high pressure at
the surface will place the region in moist west-southwest flow as a
series of upper level impulses impact the state. Increasing chances
of rain are expected...with generally slight chances of showers and
thunderstorms Thursday /beginning in the eastern portions of the
state and spreading westward/ and then chance probability of precipitation Thursday night
into Friday. This moist and active pattern is expected to continue
into the long term...bringing a close to the nice weather seen the
last few days.
Near normal to slight below normal temperatures are still expected
to continue through the short term...but for now...temperatures
should generally be well above any broken records with the current
Long term /Friday through Wednesday/...
with flow aloft shifting the southeast as the area transitions to
the eastern side of the trough...wet weather will return to north
and central Georgia for the end of the week into the weekend. This
wet pattern will remain through the long term and thinking from
the previous forecast is still in line with the updated forecast.
Main change was to the high temperatures on Friday to warm them a
degree or two across central Georgia. In addition...given latest
guidance...have cut back on probability of precipitation for Tuesday night.
Previous long term /Thursday night through Tuesday/...
/issued 406 am EDT Wednesday Jul 30 2014/
abnormally pleasant late July weather to come to an end at the
start of the long term period. Long wave trough over eastern Continental U.S.
Slowly begins to fill but axis remains just to our west through
Tuesday. As alluded above...front will wash out late Thursday as
warm/moist advection kicks in and provides sufficient lift and
moisture for rain showers/thunderstorms and rain even during nighttime periods. Not seeing
any sign of particularly intense or prolonged steady rainfall.
Basin averaged rainfall should remain around 1/4 - 1/2 inch with
local amounts of 2 to 3 inches...particularly on Friday when warm
advection is strongest. Similar to last week...overall pattern
favorable for areas of shra/tsra...some strong during peak in
instability...with deep moisture and most adiabatic lapse rates in
place through Tuesday. This pattern should also keep any potential
tropical systems in the western Atlantic offshore...well east of
US coast. In spite of recent fronts last 30 days...have sided with
bias corrected blend of MOS and wpc guidance for temperatures.
mainly VFR conditions through taf period with trending close to
MVFR near end of period early Friday. Generally some cirrus
building into tonight then cumulus field developing into near broken 4-5
kft after 18z Thursday and possibly scattered to broken near 2 kft after
03-06z Friday. Winds generally east to east-northeast under 10 kts and light
to calm overnight tonight. Precipitation chances on increase beyond
forecast period early Friday morning otherwise any shower or
thunderstorm probability late Thursday is too low to include in
//Atl confidence...00z update...
medium on ceilings Thursday night.
High on all else.
Preliminary point temps/pops...
Athens 66 84 68 81 / 10 20 30 50
Atlanta 67 83 67 81 / 5 20 30 50
Blairsville 58 77 63 74 / 10 30 50 50
Cartersville 62 83 66 81 / 5 20 30 50
Columbus 68 88 71 86 / 5 20 20 40
Gainesville 66 80 66 77 / 10 30 40 50
Macon 67 88 70 86 / 10 20 20 40
Rome 61 84 67 81 / 5 20 30 50
Peachtree City 63 85 68 82 / 5 20 30 50
Vidalia 71 90 73 89 / 20 20 20 40