Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Peachtree City Georgia
1029 am EST sun Dec 21 2014
Not a lot of changes to the grids this morning. Lowered probability of precipitation down
south...precipitation not spreading north quite as quickly as anticipated
so kept probability of precipitation at slight chance through the morning and early
afternoon with gradual upward trend later today. Added more fog to
the grids as well and increased sky cover this morning...though
we are starting to see some holes showing up. Temperatures are
lagging behind the forecast warming trend but am hesitant to lower
afternoon highs without getting a better handle on sky trends...so
no change there for now. Will send a product refresh shortly.
Previous discussion... /issued 645 am EST sun Dec 21 2014/
Previous discussion... /issued 433 am EST sun Dec 21 2014/
Short term /today through Monday/...
short term... weak high pressure ridge building down the East Coast
with low clouds and easterly flow over the state. This ridge is
expected to strengthen today so these low clouds are expected to
stay around through most of the majority of the short term. Weak
shortwave moving NE across the Gulf is pushing showers across
southern Georgia. This wave is expected to move slowly northward today
spreading precipitation into central and portions of north Georgia today and
tonight. Only expecting light rain or drizzle across north Georgia as
wedge will be firmly inplace across north Georgia. With this wedge building
in maximum temperatures to day will be an issue. Looking for temperatures to creep
into the 50s across the area but not sure if they will get that warm
as not sure just how deep The Wedge is yet.
Long term /Monday night through Saturday/...
wedge in place at the start of the period with strong upper
trough still west of the MS river. Strong southerly flow should
bring rain and a few thunderstorms into the forecast area but with
wedge in place through Tuesday...thunder should be more isolated
north and east. A few severe possible mainly along the southern
fringes of the forecast area...depending on how far The Wedge
builds. Models in good agreement that surface cold front be just
into northwest Georgia around 12z Wednesday. Rain exiting the area
Wednesday night...but still looks like a mix on rain and snow is
possible across the extreme northeast as the cold air advects
eastward. Dry for Thursday and Friday. The next system bringing
rain into the area by Saturday...but the GFS is slower with this.
IFR to LIFR ceilings across the area this morning. A weak wedge
of high pressure building into the area today will keep low
ceilings and easterly flow across the taf sites through the
period. Not expecting ceilings to get into the VFR range this taf
period but they will lift into the MVFR range by 18z. Winds will
stay out of the east at 10kt or less with only some light drizzle
from time to time across the atl area taf sites. Mcn and csg will
see rain by 00z Monday as developing shortwave moves into S Georgia today.
Visibilities will be up and down all day but should stay mainly in the
MVFR to VFR range. Will see some IFR visibilities briefly around sunrise.
//Atl confidence...12z update...
medium to high on all elements.
Preliminary point temps/pops...
Athens 51 41 50 43 / 30 60 60 50
Atlanta 52 43 52 47 / 30 50 50 50
Blairsville 51 39 48 42 / 20 60 60 50
Cartersville 52 42 52 45 / 20 30 40 50
Columbus 55 46 59 52 / 40 50 50 50
Gainesville 50 41 49 43 / 30 50 50 50
Macon 54 45 57 48 / 50 60 50 50
Rome 52 41 53 46 / 20 30 30 50
Peachtree City 52 42 55 47 / 30 50 50 50
Vidalia 52 48 60 52 / 60 70 70 50