Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Peachtree City Georgia
341 am EDT Friday Jul 31 2015
Short term /today through Saturday/...
a cold front is stalled across central Georgia this morning and
although the front will weaken through the short term and wash
out...the moisture associated with the front will remain in place
across central Georgia. Observations already show the dew points in
the low to middle 60s across parts of north Georgia and while some of
this drier air will filter further south...it wont quite make it
into central Georgia today. Given central Georgia will be south of
the stalled front...with better deep layer moisture and dew points
in the 70s this afternoon...convection should be confined to central
Georgia. MUCAPE values this afternoon climb around 2000 j/kg so
could see a few strong storms. Storm Prediction Center has the County Warning Area in general thunder.
The boundary shifts ever so slightly southward on Saturday and the
drier air moves further into central Georgia. The better probability of precipitation are
confined to the southern portion of the County Warning Area Saturday afternoon.
Even with the front moving through north Georgia...temperatures
through the short term are forecast to remain just above normal.
With these above normal temperatures and higher dew points in
central Georgia...a small area across the southeast part of the County Warning Area
has the potential to reach heat advisory criteria /105 degree heat
indices/ for a short period of time. At this point...the area of 105
values is spotty and any convection in the area will help to keep
temperatures below the forecast so will not issue a heat advisory at this
Long term /Saturday night through Thursday/...
Models are showing good agreement on a weak cold front stalled
across parts of central Georgia Saturday night... sagging further
south and into south Georgia on Sunday...then into North Florida
on Monday. This should lesson thunderstorm chances across the area
through the first part of next week as a drier air mass settles
over the region. The combination of a moist southerly surface to
middle level flow and subtle upper disturbances from the west will
bring a chance of showers and thunderstorms back to the forecast
area for Wednesday and Thursday. Modest instability and weak deep
layer wind shear continues to suggest any afternoon/evening storms
should remain below severe limits.
Behind the front... a drier air mass will help hold heat indices
below the 100 degree mark for most areas for Sunday through
Tuesday. Then as Gulf moisture begins to creep northward... near
critically high heat indices are likely to return to much of the
area by middle week.
/issued at 223 am EDT Friday Jul 31 2015/
main challenge throughout the taf period is the wind direction and
the forecast calls for multiple wind shifts at atl. There are some
inconsistencies in the guidance and due to this and timing...have
low confidence on the wind direction. Thunderstorms and rain is expected across
central Georgia today and thus better chances of thunderstorms and rain are at mcn
//Atl confidence...06z update...
high confidence on ceilings and visibilities. Low confidence on wind.
Preliminary point temps/pops...
Athens 93 69 94 70 / 10 5 10 10
Atlanta 90 72 92 71 / 20 5 10 10
Blairsville 88 60 87 59 / 5 0 5 10
Cartersville 92 64 92 66 / 5 5 5 10
Columbus 93 73 94 73 / 40 30 20 20
Gainesville 89 70 91 70 / 5 5 5 10
Macon 94 72 93 71 / 40 30 20 20
Rome 92 63 93 67 / 5 0 5 5
Peachtree City 91 67 92 69 / 20 10 10 10
Vidalia 93 75 93 74 / 50 40 30 30