Scientific Forecaster Discussion
fxus62 kffc 051720 aab
Area forecast discussion...updated
National Weather Service Peachtree City Georgia
1220 PM EST Thu Dec 5 2019
..18z aviation forecast discussion...
Previous discussion... /issued 326 am EST Thu Dec 5 2019/
Short term /today through Friday/...
High pressure will meander overhead today. The high center will
shift offshore on Friday, ahead of an approaching cold front. The
front remains to the west of the County Warning Area through the short term, but
precipitation chances will start to increase ahead of the boundary.
Models are not producing much instability with the fropa, so will
leave thunder out of the forecast at this time. Quantitative precipitation forecast values are
trending downwards with this system through Friday. Locales mainly
along and north of the Interstate 85 corridor could see up to a
around a tenth of an inch of rainfall.
Temperatures will remain above normal through the period.
Long term /Friday night through Wednesday/...
Lingering showers will be tapering off Friday night as the
aforementioned system exits eastward. By late Saturday into
Sunday, a wedge pattern will build into north Georgia as surface
high pressure moves off the New England coast. The chance for
light showers will begin to increase through the day Sunday as
southwest flow increases over the surface wedge. Temperatures
Sunday will likely be held into the low to mid 50s across north
Georgia with The Wedge in place.
The Wedge will erode Monday with deep southwest flow bringing a
continued chance for showers ahead of the large scale trough over
the Midwest. Temperatures Monday will also run around ten degrees
above normal. Timing discrepancies still remain regarding the timing
of arrival of the incoming strong cold front. The GFS is more
progressive than the European model (ecmwf) with the front pushing through the
forecast area through the day Tuesday while the European model (ecmwf) is wetter and
slower. Regardless, it still is reasonable that pops will be
maximized on Tuesday with the arrival of the front. The potential
for rainfall totals approaching 2" in parts of far north Georgia
Monday through Tuesday remains.
At this point, any lingering showers looks to clear by Wednesday
morning with high pressure building in and bringing a significant
VFR conditions predominate through the period. Will see increasing
high-level clouds this evening through the overnight period with
increasing mid-level clouds late tonight through Friday morning.
Lower-level cloud cover begins increasing, but ceilings remain VFR
through 00z Saturday. Areas of light rain/showers move into
northwest Georgia during the morning Friday and spread across
western and northern portions of the forecast area by afternoon.
Winds will be somewhat variable in direction through the period, but
wind speeds should remain fairly light (6kt or less) as well. Wind
directions are expected to be mainly southwest to northwest through
00z, becoming more east to southeast by 06z.
//Atl confidence...18z update...
Medium confidence at best concerning wind direction trends. High
Preliminary point temps/pops...
Athens 65 40 60 43 / 0 0 30 30
Atlanta 64 43 58 44 / 0 0 30 30
Blairsville 59 37 52 38 / 0 0 40 30
Cartersville 63 41 57 43 / 0 5 40 30
Columbus 68 42 64 48 / 0 0 20 30
Gainesville 63 41 56 43 / 0 0 30 30
Macon 67 39 64 46 / 0 0 20 20
Rome 63 40 56 43 / 0 5 50 30
Peachtree City 66 40 60 44 / 0 5 30 30
Vidalia 68 40 69 47 / 0 0 10 10