Scientific Forecaster Discussion
fxus62 kffc 240302
Area forecast discussion
National Weather Service Peachtree City Georgia
1102 PM EDT Tue Jul 23 2019
Pops have been adjusted to better represent lingering showers
across central Georgia. While coverage is expected to continue to
decrease through the early morning hours in the wake of the cold
front, scattered lingering showers will remain possible in these
areas through the early morning. Otherwise, drier air will
continue to filter southward across the area on Wednesday.
Previous discussion... /issued 755 PM EDT Tue Jul 23 2019/
.00z aviation forecast discussion...
Previous discussion... /issued 320 PM EDT Tue Jul 23 2019/
Short term /tonight through Wednesday night/...
Better precipitation chances already starting to shift into the
southern and eastern reaches of the forecast area along and ahead of
the low-level convergence zone. Drier airmass hanging back to the
northwest of the forecast area, but poised to move into the northwest
this afternoon. Will keep the general pop trends relatively unchanged
with likely/categorical pops shifting into the southeast this
afternoon and chance pops diminishing from the northwest as we head
into the evening. Southeast corner of the forecast area warmed nicely
with decent sunshine through the morning, so a few strong to
marginally severe storms still possible this afternoon. Threat should
be shifting east of the area as we head into the evening. Clouds
diminish across the north and west this evening, but linger through
the overnight period across central Georgia. Frontal boundary stalls
across south Georgia by tomorrow. Drier airmass makes good progress
into the area from the northwest, ending precipitation chances across
the majority of the area by tomorrow morning. Uncertainty concerning
whether or not the drier airmass completely clears the area persists,
and I have kept the low pops across the southeast corner of the
forecast area through the day tomorrow, however confidence is low.
Biggest change will be the mild (at least for late july) temperatures
over the next 36 hours. Noticeably cooler temperatures expected
through the short-term forecast period.
Long term /Thursday through Tuesday/...
Not a bad way to start off the extended when talking about near
record or record low temperatures. Per nbm guidance both Columbus
and Macon should be close Thursday am with dewpoints in the upper
50s to low 60s area wide. In the upper levels, 500mb trof will
dominate the eastern half of the country for the first part of the
extended into the weekend. Surface front which pushes through the
state today will become stationary across the northern Gulf Coast
and North Florida. This pattern starts to break down by Saturday as
the Bermuda ridge starts to build back in and a moist flow off the
Gulf returns to the region. With the return flow comes an increase
in diurnal showers and storms to near climo levels each afternoon
beginning Saturday and remaining in place through Tuesday. The
pattern overall returns to more summertime-like for the second half
of the extended and temps return to near normal Saturday through
Tuesday as well.
Tropics...the only possible fly in the ointment with the forecast is
the fact that a late July front will push through the region and
stall across the northern Gulf this week and weekend. Gefs and eps
surface pressure probs aren't at the moment too keen on anything
developing along the old boundary, however, the 06z NAM did attempt
to develop a small feature late Friday into Saturday in the northern
Gulf. The 12z run of the NAM has backed off. Nonetheless...it will
be something to watch and NHC has posted a 20% prob across the
region in the 5 day outlook.
VFR conditions have spread into atl area taf sites and are
expected to prevail through the taf period. Elsewhere, while a few
patches of MVFR or IFR cigs remain possible near lingering shra,
generally VFR is expected. There does remain some possibility for
MVFR cigs briefly around 10-12z Wednesday at mcn. Shra will remain
possible at ahn/mcn/csg through 02-03z. North-northwest winds at 10-12kts
are expected to shift to north to northeast in the 02-06z time
frame with speeds diminishing to 4-8kts.
//Atl confidence...00z update...
medium confidence on evening trends and on morning MVFR cig
potential at mcn. High confidence otherwise.
Preliminary point temps/pops...
Athens 65 86 64 88 / 30 0 5 0
Atlanta 67 83 64 87 / 10 5 0 0
Blairsville 57 80 57 79 / 10 0 5 5
Cartersville 63 84 62 88 / 10 0 0 0
Columbus 68 86 65 90 / 30 5 0 5
Gainesville 64 83 63 85 / 20 0 5 5
Macon 67 86 64 90 / 50 10 5 10
Rome 63 84 62 89 / 5 0 0 0
Peachtree City 66 84 63 87 / 20 5 0 0
Vidalia 69 85 67 89 / 80 30 10 20