Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Peachtree City Georgia
945 PM EDT Monday may 25 2015
Strong upper level high over the southeast which had kept our area
dry the past several days finally moved far enough offshore to
allow for some shortwave energy to enter the forecast area. This
along with precipitable water increasing from 1.25 inches this
morning to 1.7 inches this evening was more than enough to
initiate numerous to widespread showers and thunderstorms.
Shortwave continues to progress east and take bulk of activity
into northeast Georgia where instability has not been as
impressive. Therefore expect just garden variety thunderstorms
along with mainly showers through midnight. Current grid set has a
good handle on this and only limited changes are planned.
Previous discussion... /issued 824 PM EDT Monday may 25 2015/
Previous discussion... /issued 313 PM EDT Monday may 25 2015/
Short term /tonight through Tuesday night/...
models continue in good agreement for the short term. First wave of
precipitation...currently over Alabama will move into the County Warning Area later this
afternoon and continue into the evening hours. As this wave lifts
into the Carolinas late tonight the precipitation will diminish. However
the next wave will move into the County Warning Area late Tuesday morning and
Tuesday afternoon...then stall over the County Warning Area Tuesday night. This will
bring another round of precipitation. Total rainfall amounts for tonight
through Tuesday night will range from 1 to 2 inches across west and
north Georgia...with less than 1 inch over the rest of the area. At this
time while there may be some localized flooding in the stronger
storms...widespread flooding is not expected at this time.
Long term /Wednesday through Monday/...
extended models continue to advertise moist southerly flow across
the southeast through much of the week...keeping chance to likely
probability of precipitation across the area. A more diurnal trend is expected through the
weekend. Have made only minor adjustments...mainly to day seven
with the latest model solutions. The previous forecast discussion
is included below.
Long term /Tuesday night through Sunday/...
/issued 347 am EDT Monday may 25 2015/
moist SW flow aloft will be over the area to start the long term.
Significant deeper moisture and upper level shortwave potential
will affect north and much of central Georgia...with continued rather high
chances for showers and thunderstorms...into Thursday. Showers and
storms will have some diurnal tendency but not exclusively. Due to
the position of the upper ridge over the west Atlantic...the
highest chances of showers and storms will be over north and West
A ridge aloft builds some on Friday and continues Saturday and should
allow for a much more diurnal tendency to the showers and storms.
The GFS and European upper patterns are different on Sunday with less
influence of a ridge aloft from the European.
Rainfall totals approaching 3 inches across portions of north Georgia
into Thursday. Will be monitoring for any flood issues.
Temperatures running near to slightly above normal for daytime highs
and 2 to 7 degrees above normal for nighttime lows.
thunderstorms and rain continues to impact most of the airfields in the forecast
area including Atlanta Hartsfield. Finally starting to see some
movement to the band and should be able to remove the tempo by
02z. Once activity exits...plenty of rainfall will result in ceilings
quickly lowering with IFR now likely for all sites. Slow
improvement for Tuesday once again and another round of thunderstorms and rain in the
//Atl confidence...00z update...
medium on IFR timing.
High on remaining elements.
Preliminary point temps/pops...
Athens 66 83 66 82 / 60 70 80 70
Atlanta 68 82 67 80 / 60 80 80 70
Blairsville 65 76 64 75 / 60 70 80 70
Cartersville 67 81 66 80 / 60 80 80 70
Columbus 70 85 69 83 / 50 70 60 70
Gainesville 66 79 65 78 / 60 70 80 70
Macon 68 86 68 85 / 50 50 50 70
Rome 67 80 66 80 / 60 80 80 70
Peachtree City 68 81 67 81 / 60 70 80 70
Vidalia 71 88 70 87 / 50 40 40 30