Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Peachtree City Georgia
356 PM EDT Thursday Jul 31 2014
Short term /tonight through Friday night/...
Cloudy and rainy conditions means a gloomy end to the week. Have
continued to advertise at least slight chance probability of precipitation for late
afternoon and tonight in portions of the western and southwestern
County Warning Area...graduating to likely probability of precipitation in the far northeast mountains. The
main concern will be across north and portions of eastern
Georgia...and have kept rain chances high through Friday.
Instability continues to look limited as a result of the lack of
insolation/ ample cloud cover and although convection potential is
higher than today...strong to severe storms are not anticipated.
Across central Georgia coverage should be more limited...but still
have continued with chance to good chance probability of precipitation.
This prolonged wet pattern is expected to continue into the weekend.
The main concern will be the potential for heavy rainfall...and wpc
does have portions of northeast Georgia /at least for tonight/
highlighted for excessive rainfall potential. Through
Friday...rainfall amounts are expected to be the highest in the NE Georgia
mountains...with 1-2 inches and isolated higher amounts. Ffg values
for the area do suggest that with the several dry days this
week...soils should be able to handle this amount of rainfall
without significant issues. For now...have held off on issuing any
flash flood watches at this time...but following shifts should
continue to monitor accumulated rainfall and changing conditions.
Gloomy conditions will keep afternoon temperatures low...and it is
possible that portions of north Georgia may not warm into the 80s.
Have generally gone with a guidance blend.
Long term /Saturday through Thursday/...
Longwave trough continuing into the first of the week...filling
some by the end of the period. We remain in a broad southwest flow
aloft with a series of short waves crossing the southeast states.
Have made no changes to the extended as it continues to look like
a wet period. Previous discussion is included below.
/405 am EDT Thursday Jul 31 2014/... wet weather starting in the short
term will continue into the extended. Long wave trough over
eastern Continental U.S. Slowly begins to fill but axis remains just to our
west before lifting out Tuesday. This puts Georgia in moist
southwesterly flow through the weekend with waves traversing the
area off and on through the middle of next week. Warm/moist
advection kicks in and provides sufficient lift and moisture for
rain showers/thunderstorms and rain even during nighttime periods. Will still keep a diurnal
trend through the extended forecast but keeping in good chance
probability of precipitation through the night time hours. Not seeing any sign of
particularly intense or prolonged steady rainfall as these weak
disturbances move quickly through the area. Basin averaged
rainfall should remain around 1/4 - 1/2 inch with isolated higher
amounts. The 4-5 day quantitative precipitation forecast forecast shows 1-3 inches state wide with
the best rainfall staying south and east of the County Warning Area. With rain
expected across the area through next week temperatures will stay
slightly below seasonal norms.
high MVFR to VFR conditions expected through the evening hours...with
conditions degrading to IFR by 08z. Some improvement is expected
Friday...but do not anticipate VFR conditions until 18z or after.
Rain chances are low enough this afternoon and tonight...and have
only included prob30 -ra for the 09-15z time frame. Prevailing
showers expected thereafter. Winds should stay on the east-northeast-NE side
at 7kt or less through the period.
//Atl confidence...18z update...
medium confidence on all elements...except high confidence on winds.
Preliminary point temps/pops...
Athens 67 82 68 85 / 60 60 50 60
Atlanta 68 82 69 83 / 40 50 40 50
Blairsville 62 75 64 77 / 70 70 50 60
Cartersville 66 82 68 84 / 50 50 40 60
Columbus 70 88 71 87 / 30 40 30 50
Gainesville 66 78 68 81 / 70 70 50 60
Macon 70 86 70 86 / 30 40 40 50
Rome 66 83 68 83 / 50 50 40 60
Peachtree City 68 84 68 85 / 40 50 40 50
Vidalia 72 90 73 91 / 30 50 30 60