Scientific Forecaster Discussion
fxus62 kffc 261104
Area forecast discussion
National Weather Service Peachtree City Georgia
704 am EDT Mon Jun 26 2017
forecast is on track with cool temperatures this morning,
gradually increasing under mostly clear skies. Am observing some
mid and high clouds across the region. Anticipate the mid level
decks to erode with mixing while high clouds continue to stream
into the area through much of the day.
Previous discussion... /issued 350 am EDT Mon Jun 26 2017/
Short term /today through Tuesday/...
Have been updating the hourly temperatures tonight as models are
struggling to grasp the overall extent of this unseasonably dry and
cool airmass. Many across the high terrain will wake to
temperatures in the mid 50s.
High pressure will continue to build into the area from the north
and west through the period. This will mean very pleasant conditions
across much of the area through the short term. The front that
crossed the area Sunday night is draped well south of the region
with little to no diurnal convection expected across central Georgia this
afternoon. Some high clouds will start to filter into the area
throughout the day. However, Monday night into Tuesday, we will
likely see better coverage of cirrus across the region as a series
of weak impulses round an upper level trough. The trough axis will
cross Georgia late Tuesday afternoon. Given such a dry airmass at the
surface, it will be tough to get enough lift to promote
shower/thunderstorm development despite trough. However, those
across the higher terrain may see an isolated shower or thunderstorm
as orographic effects will help with this issue. Also, there may be
enough convergence across the southeast portion of the County Warning Area to see diurnal
convection Tuesday afternoon. Either way, the probability is pretty
low, but it is there. Temperatures throughout the period will be
slightly below normal.
Long term /Tuesday night through Sunday/...
a dry air mass is in place at the start of the period with a
surface ridge centered over the Appalachians. The ridge gradually
moves east...and by Thursday the return flow is bringing moisture
back into the state. Models continue to hint at a weak short wave
in the northern Gulf by the weekend...and also a front approaching
from the Ohio Valley toward the end of the period. In general we
remain in a tropical air mass from Thursday and beyond and chance
pops for most areas each day look reasonable.
VFR conditions expected through the taf period as high pressure
builds into the region from the west. Anticipate some scattered
high clouds through the day. Winds are out of the northwest currently,
but will eventually veer to the NE during the morning as mixing
increases. Winds around 8-10kts through the day. The extend of
this wind shift is a bit in question given the placement of the
surface high. As the gradient tightens a bit later in the
afternoon ahead of a mid- level disturbance, this should back the
winds to the northwest for the northern taf sites. We will see skies
clear for the most part during the evening, and then cirrus
filling back in ahead of the aforementioned disturbance.
//Atl confidence...12z update...
moderate confidence of timing/duration of the NE wind shift.
Confidence high on all elements.
Preliminary point temps/pops...
Athens 85 64 85 62 / 0 5 10 0
Atlanta 84 65 84 65 / 0 5 10 0
Blairsville 79 57 77 54 / 0 10 20 0
Cartersville 84 61 83 61 / 0 5 10 0
Columbus 87 66 88 68 / 0 5 10 0
Gainesville 83 63 82 62 / 0 5 10 0
Macon 86 64 88 66 / 0 5 10 0
Rome 85 60 84 60 / 0 5 10 0
Peachtree City 85 63 85 63 / 0 5 10 0
Vidalia 86 69 88 69 / 20 10 20 10