Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 221524

Area Forecast Discussion
National Weather Service Peachtree City GA
1124 AM EDT Thu Jun 22 2017


Near term update consisted of adjusting categorical/likely pop
trends in the NW half of the CWA given actually good hi-res
consensus of progged precip in line with fcst isentropic upglide
zones as we get into the broad warm sector of the Cindy remnants
to the west. Given this, we are still in a highly efficient precip
regime and while no flood watch products are out, there still
could be isolated flash flooding especially where any more
convective training could develop given a more likely
destabilizing environment later today into this evening. Have also
mentioned the possibility of an isolated tornado in the far NW
with a low end sig tor parameter being reached due to the
increased low level helicity. Day 1 SPC outlook still has a
Marginal Risk out for mainly north and west of the Atlanta metro.

Also bumped daytime highs down a few degrees for most areas that
has had the persistent low level cloud deck this morning around
the precip shield providing good solar sheltering. Previous
discussion follows...



.PREV DISCUSSION... /Issued 728 AM EDT Thu Jun 22 2017/

.SHORT TERM /Today through Friday/...

Shear axis/weak boundary that has been plaguing the the CWFA for the
last few days will finally shift northward today. Meanwhile, high
pressure aloft and at the surface will try and get a foothold in the
SE portion of the CWFA.

With the shear axis/weak boundary shifting northward today, the
focus for any precip will also be shifting northward. Even though
the airmass will remain very moist and tropical, precip should
mostly remain unorganized for most of the outlook area. Since the
boundary will flirt with the GA/TN border, extreme northern GA
should have the highest amounts of rainfall for the short term
period. Currently, widespread 1" to 2" is possible in this area, but
some locally higher amounts are possible through Friday. For now,
these values shouldn`t cause any widespread flooding issues, but
some localized flooding is possible. Will hold off issuing a Flood
Watch for now. The axis should remain mostly north of the CWFA again
on Friday, so the highest chances will remain in that area.

Hi temps today and Friday will creep up a few degrees, but still
average a few degrees below normal. Even a few peeks of sunshine are
possible south of I-20 today. A bit more sunshine is possible on



.LONG TERM /Friday Night through Wednesday/...

First half of the extended forecast period remains rather damp as we
deal with the approach, passage and remains of Cindy. Still looking
at Friday night as the main severe weather threat as the low/mid-
level shear associated with the remnants of Cindy sweep through the
region. Instability appears to be moderate at best, but sufficient
to support the marginal to slight risk of severe wind gusts with an
isolated tornado threat. General area of interest still looks to be
roughly along/north of the I-85 corridor. Flood threat will be highly
dependent on how much rainfall we get in the next 36 hours leading
up to the passage of the low. Frontal boundary gets stretched out
across the forecast area Saturday with ample moisture remaining. Main
focus for precipitation shifts into central Georgia at that time and
slowly diminishes from north to south through Monday/Tuesday.

End of the extended forecast period is looking dry and quite pleasant
for the middle of summer. Northwest upper flow and surface high
pressure building over the eastern U.S. ushers in a dry airmass and
temperatures at or below seasonal normals.



12Z Update...
BKN IFR cigs should continue for the next several hours, along
with the on/off light rain showers. Do expect cigs to gradually
lift through the morning, and eventually settle around 035. Winds
may flirt with due south later this afternoon, but overall, the
direction should remain on the east side. Models are hinting at
IFR cigs again overnight...but kept at low MVFR for now.

//ATL Confidence...12Z Update...
Medium confidence cigs. High confidence remaining elements.


Athens          81  71  89  72 /  70  60  30  50
Atlanta         80  72  87  73 /  80  60  30  60
Blairsville     74  67  82  68 /  90  70  60  70
Cartersville    79  72  86  72 /  90  60  50  70
Columbus        84  74  90  75 /  70  20  30  40
Gainesville     77  70  86  72 /  90  60  30  60
Macon           87  73  91  74 /  50  30  30  20
Rome            78  72  87  72 / 100  60  60  80
Peachtree City  80  71  88  72 /  80  50  30  50
Vidalia         89  75  92  75 /  50  40  30  20




SHORT TERM...NListemaa/Baker
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