Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Peachtree City Georgia
1016 PM EDT Tuesday Jun 30 2015
I have made a few adjustments to the near term forecast grids. Mainly
hourly temperatures...sky and probability of precipitation. Most convection has dissipated
but we will likely see isolated showers and even a little thunder
popping at random through the overnight period. Atmosphere has
stabilized enough for the threat of severe weather to become minimal
through the remainder of the night and into early tomorrow morning.
No significant changes made past 12 hours at this time.
Previous discussion... /issued 745 PM EDT Tuesday Jun 30 2015/
Short term /tonight through Wednesday night/...
thunderstorms did in fact return to the area with a vengeance thanks
to the first disturbance rounding the broad trough in place over the
eastern US. Analyzed cape values in excess of 3000 j/kg have allowed
several storms to become severe through this afternoon...and as a
result a Severe Thunderstorm Watch has been issued for the eastern
portions of the County Warning Area through 00z. Cannot rule out some additional
scattered convective development across western portions of the area
through this evening so have opted to keep in probability of precipitation in these areas to
reflect this possibility. That being said...earlier convective
activity has decreased instability in these areas...and most shower
and storm coverage should remain in association with the band
traversing our eastern and southern zones.
Overnight tonight most areas should dry out before our next
disturbance brings more showers and thunderstorms on Wednesday
afternoon. Highest coverage will be across the northern zones on
Wednesday...though scattered diurnal activity will be possible
elsewhere. Some strong to isolated severe thunderstorms will again
be possible...but lapse rates look less impressive.
The area should grow accustomed to this weather pattern because it
looks to stay for a while.
Long term /Thursday through Tuesday/...
models continue in agreement with holding the upper trough over
the eastern U.S. Through the week. There is some strength
differences in the short waves as they rotate through the flow and
over the County Warning Area but both the GFS and European model (ecmwf) agree on timing and this
has given more confidence in the solution. However by the weekend
differences in the upper trough solution occur with the European model (ecmwf)
flattening out the trough while the GFS maintains a trough. The
GFS solution also keeps moisture over the County Warning Area which is being more
consistent from run to run while the European model (ecmwf) is no longer progging a
strong 500 mb high over the County Warning Area. For these reasons have leaned more
toward the GFS solution and have kept probability of precipitation in through the weekend.
VFR conditions are expected to predominate through the majority of
the forecast period. Will see scattered MVFR or lower visibilities
developing after 03z...lasting through 14z. May see some local MVFR
or lower ceilings in this same time frame as well...but confidence
is low. Convection across the area has just about dissipated at this
time...but isolated showers or thunderstorms will remain possible
through the overnight period before coverage increases after 16z
tomorrow. Winds will remain westerly 3-8kt.
//Atl confidence...00z update...
Confidence medium to high.
Preliminary point temps/pops...
Athens 68 89 70 88 / 40 50 50 70
Atlanta 69 86 70 85 / 30 50 50 70
Blairsville 62 79 63 79 / 40 60 60 80
Cartersville 66 86 68 84 / 30 60 60 80
Columbus 70 89 72 90 / 30 40 30 60
Gainesville 68 85 69 84 / 40 60 60 70
Macon 69 91 71 92 / 40 30 30 60
Rome 67 86 69 85 / 30 60 60 80
Peachtree City 68 87 70 86 / 30 40 50 70
Vidalia 72 91 73 92 / 50 30 30 50