Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Peachtree City Georgia
257 PM EDT Tuesday Oct 21 2014

Short term /tonight through Wednesday night/...
pleasant weather will continue through the short term. County Warning Area remains
on the western side of a strong low pressure system over the
East Coast and this allows the northwest flow aloft to continue. Will see
cooler temperatures tomorrow as compared to today with a secondary
front pushing southward that will serve to reinforce the dry
front that moved through last night. Low temperatures will dip
into the middle 30s across very isolated areas in NE Georgia tonight.
Have included patchy frost for these areas. Too isolated though
for a frost advisory. Low temperatures are expected to cool even
more for Thursday morning and even though the latest forecast is a
degree or two above the previous forecast...this still results in
widespread temperatures in the middle to upper 30s. Will have to
monitor temperature trends for Thursday morning as a frost
advisory may be needed for parts of north Georgia that dip down
into the middle 30s.


Long term /Thursday through Tuesday/...
only a few minor changes to the extended forecast. Still expecting
dry conditions to persist through the extended. By late week into
the weekend...the European model (ecmwf) brings a shortwave into the Tennessee Valley that
would bring increased cloud coverage to far north Georgia. It
keeps precipitation with this just north of the County Warning Area. The GFS
though is much more subtle with this feature and does not bring
any impacts into the County Warning Area. At this point either way...area remains
dry. Will continue to monitor though for any changes with this
system. Next chance of rain remains outside the extended forecast
period...generally Tuesday night into Wednesday of next week and 12z
European model (ecmwf) run is coming more into line with GFS in regards to this


Long term /Wednesday night through Monday/...
/issued 248 am EDT Tuesday Oct 21 2014/
the extended period begins with a moderately strong high pressure
system settling over the Ohio Valley with ridging southward
through north Georgia. Guidance definitely trending cooler with
this system with some members indicating lows around freezing for
the higher elevations of the mountain counties. Went with a bias
corrected blend for now which for the most part does keep most
areas above freezing but will need to be watched closely with
subsequent forecasts. Appears we may see just enough low level
flow to preclude significant frost development across the metropolitan but
lighter wind to the north should yield patchy to perhaps even
areas of frost by Thursday morning.

Tranquil conditions persist for the remainder of the long term
period with only threat of any measurable precipitation with the next
front late Tuesday into Wednesday morning. Should be just outside
of this forecast cycle and 12z Euro did not even pick up on this
potential but will take a look at 00z Euro before making final
decision on probability of precipitation. For now though...leaning toward continued dry
forecast for the next seven days.



18z update...
few to sct040 clouds will persist this afternoon across the atl
and ahn sites. These clouds should diminish by sunset though.
Winds are increasing this afternoon with gusts of 15-18kts. These
too should diminish around sunset. Patchy MVFR fog is possible
again in the morning and have mentioned in ahn.

//Atl confidence...18z update...
high confidence on all elements.



Preliminary point temps/pops...
Athens 43 69 40 71 / 0 0 0 0
Atlanta 47 67 45 69 / 0 0 0 0
Blairsville 38 62 35 68 / 0 0 0 0
Cartersville 42 66 36 69 / 0 0 0 0
Columbus 49 72 44 73 / 0 0 0 0
Gainesville 45 66 43 68 / 0 0 0 0
Macon 45 73 39 74 / 0 0 0 0
Rome 41 66 38 70 / 0 0 0 0
Peachtree City 41 69 37 70 / 0 0 0 0
Vidalia 53 73 47 74 / 0 0 0 0


Ffc watches/warnings/advisories...


Short term...11
long term....17/11

National Weather Service Glossary of Abbreviations