Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 191150

Area Forecast Discussion
National Weather Service Peachtree City GA
750 AM EDT Mon Aug 19 2019


Updated for the 12Z Aviation Discussion.


.PREV DISCUSSION... /Issued 413 AM EDT Mon Aug 19 2019/

SHORT TERM /Today through Tuesday/...
To begin the short term period, the forecast area will be situated
near a weak upper level trough positioned between a broad upper
level ridge in place to the west of the forecast area over the
Central Plains, and to the east of the area over the western
Atlantic. The upper-level troughing is allowing for a northward
advection of the deeper moisture, which will lead to a continued
moistening of the airmass and an overall unsettled pattern through
the period. PWATs of 1.3-1.6 inches across the area this morning
will steadily increase to 1.7-2 inches by Tuesday afternoon. At the
surface, a weak surface low in south Georgia will continue to slowly
traverse northward into Georgia through the period. This overall
pattern will allow for greater coverage of diurnally driven
convection during the afternoon and evening on Monday and Tuesday,
with primarily high-end chance to low-end likely PoPs expected
across the area each day.

Widespread severe weather is not anticipated on Monday and Tuesday,
although it is possible that a few storms may become strong to
marginally severe and could produce gusty winds and frequent
lightning. With the increased moisture, there is a possibility that
some of the stronger thunderstorms could produce locally heavy
rainfall, as well. Forecast high temperatures are expected to remain
above climatological normals on Monday. Especially along and north
of the I-85 corridor where highs could range from 5-8 degrees warmer
than average. Heat index values are anticipated to remain below Heat
Advisory criteria, but will nonetheless reach near or just above 100
across much of the area on Monday, with the exception of the higher
elevations in northeast Georgia. Increased sky coverage and
convective coverage will contribute to slightly cooler temperatures
and heat index values less than 100 on Tuesday.


LONG TERM /Tuesday Night through Sunday/...
Diurnally driven scattered to numerous showers and thunderstorms
will be the norm in the extended periods of the forecast. The area
will remain situated in the weak upper trough between the ridge
over the Plains and western Atlantic ridge. Moisture continues to
slowly increase across the area through the end of the week which
will will provide a boost each afternoon for convective development.
By the end of the week, the models are showing a cold front
pushing south out of the great lake state Thursday and into North
GA Friday. The models show this frontal boundary stalling across the
southeastern U.S. and keeping rain chances across the region
through the end of the forecast period. Another weaker wave also
pushes northeast out of the western gulf which will also keep
precip chances going through day 7. As for now, will continue
with scattered to numerous convection each day.

Temperatures, while tempered somewhat by increased convection, will
remain above normal through the week. The increased moisture will
also keep afternoon heat index values from the upper 90s to low



12Z Update...
IFR to low-end MVFR ceilings are in place over the southern
portion of the forecast area, including CSG/MCN and are expected
to build northward over ATL/AHN by 13Z. Conditions will then
improve by 14-15Z this morning. Soon after, a cu field at mainly
030-050 will develop and remain through the afternoon into the
evening. Scattered convection is anticipated to develop across
the forecast area during the afternoon hours. Coverage appears
sufficient to support a TEMPO group for TSRA starting at 19-20Z.
Winds through the TAF period are expected to be 6 kts or less,
starting from SE, becoming E by late morning and shifting back to
SE by 02-03Z Tuesday. Tomorrow morning, it is possible for MVFR
ceilings and visibility restrictions to develop across CSG/MCN/AHN
after 09Z.

//ATL Confidence...12Z Update...
Medium confidence on all elements.



Athens          95  71  89  70 /  40  40  50  40
Atlanta         94  73  89  72 /  50  40  50  30
Blairsville     87  66  85  65 /  40  30  50  30
Cartersville    97  71  92  71 /  40  30  30  30
Columbus        94  74  90  72 /  50  40  50  30
Gainesville     93  71  89  71 /  40  30  40  30
Macon           91  72  88  71 /  50  50  50  40
Rome            97  72  93  71 /  30  20  30  20
Peachtree City  95  72  91  71 /  50  40  50  40
Vidalia         87  73  89  72 /  70  50  40  20




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