Scientific Forecaster Discussion

Return to Local Conditions & Forecast
Area forecast discussion 
National Weather Service Peachtree City Georgia
951 PM EDT Wednesday Apr 23 2014

Update...

With such low dewpoints across the area...temperatures should drop off
rather quickly tonight as winds die off providing for excellent
radiational cooling conditions. Have therefore adjusted diurnal
trend in temperatures tonight just slightly but by and large left min
temperatures as is.

For tomorrow night into Friday...new model guidance has some
consensus on likely probability of precipitation moving into the northwest zones although cape
will be diminishing. Have upped probability of precipitation accordingly but going with
chance thunder along with the likely showers. Close to 40 knots low
level jet with this system at 925mb so cannot rule out a strong
storm over the far northern zones primarily.

&&

Previous discussion... /issued 811 PM EDT Wednesday Apr 23 2014/

Previous discussion... /issued 348 PM EDT Wednesday Apr 23 2014/

Short term /tonight through Thursday night/...
drier air has pushed just south of the forecast area as seen from
the afternoon cumulus that has developed along and south of our
southern tier of counties. Expect dry air and upper ridge to
dominate the area through Thursday. Some return moisture beginning
tomorrow afternoon as winds shift to southeast. Next short wave
moving through the Ohio Valley tomorrow night should bring a chance
of showers and a few thunderstorms beginning around 06z...mainly
over northern zones. Best dynamics look concentrated across that
area...but instability seems marginal. Not expecting severe storms
at this time. Have stayed close to a mav/met blend.

41

Long term /Friday through Wednesday/...
extended forecast continues to look good...with only minor changes
to update current grid thinking. Models continue to advertise
frontal system pushing into the state early Friday morning.
Although showers and thunderstorms are expected...coverage is
significantly limited by lack of available moisture accompanying
the front as it moves into eastern and central Georgia. Next big
rain producer still looks to be early next week...with models
still suggesting widespread 1-2 inches...especially across north
Georgia. The previous discussion is included below...

31

/issued 403 am EDT Wednesday Apr 23 2014/
high pressure that dominates the short term moves east off the middle
Atlantic coast and becomes centered just off the Carolina/Georgia
coast by 00z Friday. The next frontal system to affect the area
begins developing over the plains states Wednesday afternoon. The main
low center deepens and moves NE to the western Great Lake states
Thursday afternoon. The tail end of the associated cold front pushes
into northwest Georgia by 06z to 12z Friday. The models are still showing a
decent amount of instability with the Friday system so still keeping
showers and thunderstorms in the forecast. The models are also
still not showing much available moisture so we should not see any
issues with flooding. There is another weaker frontal boundary
that moves in Sat morning which helps to reinforce the first one
and keep a chance of precipitation through the beginning of next week.
This pattern is looking more and more like a like a summertime
pattern than a Spring pattern with decent cape and low shear.
Starting Friday...convective available potential energy and lifted indices peak everyday around 18z and fall
off rapidly by 00z. Temperatures also look more like Summer beginning Thursday
with highs mainly in the 80s. Lows will be in the 50s and 60s.

41

Aviation...
00z update...
very dry airmass in place resulting in clear skies for all the
terminals with clouds relegated to far south Georgia. Should be an
increase in moisture for Thursday but only enough to produce a scattered
middle level deck at best. Better low level moisture to arrive Thursday
night but just outside this taf cycle with MVFR pushing in from
the southeast by Friday morning.

//Atl confidence...00z update...
high on all elements.

Deese

&&

Preliminary point temps/pops...
Athens 48 78 58 81 / 0 5 5 10
Atlanta 51 76 60 78 / 0 5 5 10
Blairsville 43 73 54 74 / 0 5 30 70
Cartersville 44 77 58 78 / 0 5 10 40
Columbus 53 81 60 81 / 0 5 5 10
Gainesville 49 73 59 77 / 0 5 5 40
Macon 49 81 59 83 / 0 5 5 5
Rome 44 77 57 78 / 0 5 60 30
Peachtree City 44 79 57 79 / 0 5 5 5
Vidalia 56 81 62 83 / 0 5 5 10

&&

Ffc watches/warnings/advisories...
none.
&&

$$

Short term...deese
long term....11
aviation...deese