Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Peachtree City Georgia
331 PM EDT Wednesday Apr 1 2015
Short term /tonight through Friday/...
in the wake of a departing short wave that brought storms to the
area last night... high pressure and drier conditions have
prevailed today. This trend will continue overnight... with the
main concern being patchy fog after midnight. Clear skies... light
winds and moist grounds... especially for areas south of the I-20
corridor... will be conducive for the development of patchy dense
fog later tonight. This may be hindered though by models showing
easterly winds increasing toward morning as a wedge of high
pressure noses down from the east-northeast. The fog will lift by middle morning
with low and middle cloudiness lingering into Thursday afternoon.
Models agree on an upper disturbance approaching the state
Thursday morning... warranting a slight chance of showers across
far north Georgia late tonight/early Thursday morning. The disturbance
could spread showers and thunderstorms into central Georgia Thursday
afternoon as a deep southerly flow increases moisture and
instabilities during daytime heating. Have blanketed the area with
a chance of thunderstorms for Thursday afternoon and evening. This
threat ends Thursday evening as disturbances push east. Expect
patchy fog to return Thursday night-Friday morning. A cold front
approaches northwest Georgia Friday afternoon. This could spark scattered
storms across parts of far north Georgia Friday afternoon. No severe
storms are expected for Thursday or Friday at this time. For
temperatures...took a mav and met blend through the short term.
Long term /Friday night through Wednesday/...
GFS/European model (ecmwf) models continue to agree on timing of the cold front
moving across the forecast area Friday night into early Saturday
as a upper trough pushes it through the area. The front approaches
northwest Georgia around 00z Saturday and exits east-central Georgia by 18z
Saturday. Since the boundary is coming through during the
overnight hours...models showing limited instability. Definitely
expect thunderstorms along/ahead of the front...but not expecting
severe at this time.
High pressure begins to build in behind the front later Saturday
into Sunday and moves offshore on Monday...with southerly flow
once again bringing Gulf moisture across the state. Diurnally
driven showers and thunderstorms will be possible Monday and
Tuesday ahead of the next cold front which GFS is bringing across
on Wednesday. Models have diverged considerably by midweek and
will continue chance probability of precipitation for now.
Will continue trend of warmer temperatures Friday night into Saturday
with colder air filtering into the area behind the front for
Saturday and Sunday. Stayed pretty close to guidance temperatures
through the rest of the extended periods.
/issued at 141 PM EDT Wednesday Apr 1 2015/
VFR mostly clear conditions will persist until MVFR ceilings spread
in around 05-06z... then IFR by 08-09z tonight as an easterly flow
sets up across the taf sites. Expect ceilings to be slow scattering on
Thursday... but should see scattered middle clouds by 19-20z Thursday as a southeast
flow becomes established during afternoon heating. Current light
northwest winds should swing more westerly late this afternoon... then SW
this evening... then around to easterly tonight by 06z. Speeds
will be 6kts or less this afternoon... and 7-9kts later tonight
once the easterly winds set up. Expect 9-12kts east-southeast winds on Thursday.
//Atl confidence...18z update...
medium confidence all elements.
Preliminary point temps/pops...
Athens 55 69 58 78 / 10 40 40 20
Atlanta 59 72 59 78 / 20 50 20 20
Blairsville 51 61 54 73 / 20 50 40 30
Cartersville 54 71 56 78 / 20 50 20 20
Columbus 58 80 57 80 / 10 40 10 10
Gainesville 55 66 56 75 / 20 50 30 20
Macon 55 76 57 81 / 10 40 20 10
Rome 54 74 56 78 / 20 50 20 30
Peachtree City 54 74 55 79 / 10 40 20 20
Vidalia 58 78 61 83 / 10 40 20 10