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Area Forecast Discussion (AFD)

Issued by Peachtree City, GA (FFC)

FXUS62 KFFC 201747

Area Forecast Discussion...Updated FOR aVIATION
National Weather Service Peachtree City GA
140 PM EDT Wed Jun 20 2018


No changes to the forecast.


.PREV DISCUSSION... /Issued 435 AM EDT Wed Jun 20 2018/ 

SHORT TERM /Today through Thursday/...
A broad scale view of the CONUS around 0730z this morning depicts an 
area of low pressure centered roughly near the MT/Dakotas border 
with quasi zonal-flow located downstream across the Midwest and GL 
regions. Weak ridging still evident over the far Southeast with a 
stronger ridge building across the CA/AZ/Mexico/Baja vicinity. In 
the lower levels...nearly stationary boundary still evident across 
the OH Valley westward into the Central Plains. Weak high pressure 
still located south of the boundary across the Southern US with a 
weak low offshore N Carolina and associated troughing present down 
the leeward side of the Appalachians.

This morning a very weak shortwave trough across northern AL/central 
TN is associated with some isolated shower activity to our west. As 
this shortwave pulls NE over the next several hours...rain chances 
should remain north and west of the area. As we go more into the day 
today...most of the area will be protected by whats left of the 
mid/upper ridge. However..current moisture over northern MS has 
potential to make it into north Georgia this afternoon in the form 
of isolated to scattered showers and thunderstorms. Elsewhere...very 
isolated afternoon/evening single cell convection is expected given 
strong daytime heating...tho somewhat drier air under the ridge 
should actually keep most of the area dry today.

By tonight...previously mentioned low across MT/Dakotas will dig 
south into the Mid MS Valley and strengthen as it encounters the 
stationary sfc boundary. This along with a lifting shortwave over TX 
will pull tropical moisture north/northeastward over weakening SE 
ridge. As the ridge breaks down further through the day 
Thursday, an open lane for moisture transport will exist. This 
should allow for much better convective coverage by Thursday 
afternoon, particularly across north Georgia. Evidence of mid 
level flow increasing to near or just over 25-30kts should support
the potential for clusters of storms to develop and thus 
increasing the chance to see some isolated strong/severe activity.


LONG TERM /Thursday Night through Tuesday/...
Extended period begins with short-term ridge really losing its
hold over the region as low pressure traverses the Midwest and
approaches the state. Steady stream of moisture remains present
over the region through late week and into the weekend as parent
low enters the Ohio Valley region and disturbances swing through
the base of the trough. Have generally gone with likely pops over
far north Georgia and good chance elsewhere as these features will
enhance precip coverage. Expect best coverage to still be
associated with daytime heating, but it's unlikely precip activity
will completely shut off through the overnight periods. 

Upper level zonal flow remains over the region in the wake of the
low. By early next week, weak, broad high pressure sets back up 
with plenty of moisture trapped under the ridge. As a result,
expect seasonal thunderstorm chances each day.

Temperatures will remain warm through the extended period. Highs
in the upper 80s to mid 90s will combine with dewpoints in the 70s
to produce heat index values in the upper 90s to low 100s,
particularly over portions of central and eastern Georgia. During
prolonged periods outdoors, take frequent breaks and drink plenty
of water.



18Z Update...

Cumulus deck SCT040-050 should develop during the afternoon across 
most of the taf sites. Clouds should dissipate during the early 
evening. Only isolated thunderstorms possible this afternoon and 
evening and probability too low to include in tafs. Will watch and 
see if and where they develop. Winds should remain mainly nortwest 
to north and diminish after 00z. Winds becoming more southwest 
tomorrow. Expect an increase in shower and thunderstorms development 


//ATL Confidence... 18Z Update... 

High on all elements.



Athens          96  73  93  71 /  10  20  60  40 
Atlanta         94  75  88  72 /  10  20  60  50 
Blairsville     87  67  82  66 /  30  40  60  60 
Cartersville    93  71  87  70 /  20  30  60  50 
Columbus        95  76  91  74 /  10  10  40  30 
Gainesville     92  73  87  70 /  10  20  60  40 
Macon           95  74  93  73 /  10  10  40  30 
Rome            93  72  87  71 /  20  40  60  40 
Peachtree City  94  73  89  71 /  10  20  50  40 
Vidalia         96  75  95  75 /  30  20  40  20