Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 231826

Area Forecast Discussion
National Weather Service Peachtree City GA
226 PM EDT Mon May 23 2022

...Updated for 18Z Aviation Discussion...

.PREV DISCUSSION... /Issued 1134 AM EDT Mon May 23 2022/


The center of low pressure along the AL/GA border will continue
to push northeastward today bringing showers and the potential for
isolated thunderstorms to the forecast area this afternoon. Any
thunderstorms that develop could become strong to severe, capable
of producing damaging winds, hail, and periods of locally heavy
rain. A few minor adjustments have been made to the forecast
grids this morning, but otherwise, the forecast remains on track.

PREV DISCUSSION... /Issued 417 AM EDT Mon May 23 2022/

Wet, unsettled pattern expected to clear by the weekend...

SHORT TERM /Today through Tuesday/...

A hybrid low-pressure system is forecast to move through the
northern forecast area this morning, bringing widespread rains to
the forecast area for the first time in a while for some local
spots. We describe the system as `hybrid` because it sits on the
dividing line of true tropical, warm-core, symmetric low pressure
systems, and mid-latitude cyclones which exhibit more cold-core,
asymmetric properties. This low-pressure system is supported by a
weak, upper-level trough, but the surface low-pressure is the more
dominate organizing feature located in the warm, moist sector of a
broader synoptic system. The low also has an organized rain shield
on its right-front quadrant with an associated low-level jet of 30-
35kts between 850-700 hPa but doesn`t appear to have associated
frontal/baroclinic zones.

Either way, several waves and bands of showers and thunderstorms are
expected throughout the morning and into the early afternoon with
the low center expected to push through North Georgia this
afternoon. A Marginal risk for severe storms will be possible, in
part due to a strong low-level jet which could enhance the northern
outflow of water-loaded downdraft regions in any stronger storms
that develop in organized bands of convection.

In the wake of this low pressure system, the environment will remain
in a warm, moist airmass, with cloudy skies and deep moisture with
PWATs over 1.6 inches and some weak instability. A plume of enhanced
PWATs near 2 inches may be a catalyst for further storm development
in the afternoon along a pseudo-frontal boundary, but placement of
this boundary and intensity of any shower/storm development is yet
to be determined.

A brief break in the precip is expected overnight, but by tomorrow
scattered sporadic clusters of showers and thunderstorms will
return. These conditions will occur as an amplifying Rossby Wave
train amplifies over the eastern and central CONUS with strong south-
southwesterly flow over the Southeastern US, setting up an active
pattern headed into the long term. Further bands or weak-meso lows
could organize convective development tomorrow as well, but no where
near the same extent of the system passing through the area today.


LONG TERM /Tuesday Night through Sunday/...

Extended period kicks off with persistent, moist air mass
positioned over the Southeast as it gets caught in the periphery
of the high pressure ridge to the east, and a progressive trough
to the west. As the low traverses the Plains and approaches the
region Thursday afternoon, the combination of the anchored ridge
and reinforcing southerly flow will keep anomalously high
precipitable water values near 2 inches over the state. Diurnal
showers and thunderstorms are expected Thursday, with better
coverage in the afternoon and evening, but not fully shutting off
overnight. QPF is highest over far north Georgia where orographic
lift and better moisture will support periods of heavy rainfall.
In this area, rainfall totals of 2 inches or more are possible,
with generally 1-1.5 inches generally along and north of the fall
line, and 0.3 to 0.5 over the southeastern zones. An experimental
Day 4 Slight Risk of Excessive Rainfall from WPC includes portions
of northeast Georgia and will continue to be monitored.

Recent dry conditions should prevent widespread issues from the
heavy rainfall, accumulations through the short term period could
prime portions of the state for more of a response. At this time,
flooding risk still appears limited.

Models continue to show some promise ending the precipitation by
Friday afternoon as parent low lifts to the northeast and surface
front pushes east and south across the state -- just in time for
the holiday weekend. Behind the front, northwesterly flow and
high pressure at the surface will keep dry conditions in place
through Sunday, with mild temperatures through the week returning
to the mid to upper 80s by Saturday.



18Z Update...
IFR/MVFR cigs/vsbys across northern TAF sites this afternoon will
drop to IFR early tomorrow morning with LIFR cigs possible
between 10 and 13Z. MVFR cigs/vsbys return to northern TAF sites
between 14 and 18Z tomorrow. SSW winds turn W at 10-20kts gusting
up to 35kt at times through 00Z before becoming VRB03KT overnight
at northern TAF locations. MCN/CSG forecast to remain MVFR with
TEMPO TSRA this afternoon and evening mainly from 18 to 03Z. SW
winds at MCN/CSG around 8kt become light overnight before
returning to 5kt tomorrow.

//ATL Confidence...18Z Update...
Low to medium confidence on timing and coverage of TSRA at
MCN/CSG this afternoon/evening. Medium confidence on IFR/LIFR
timing and coverage tonight/tomorrow morning. High confidence on
all other elements.



Athens          76  64  84  64 / 100  20  30  50
Atlanta         74  64  81  66 / 100  20  40  50
Blairsville     70  59  80  61 / 100  40  30  50
Cartersville    73  61  83  64 /  90  20  40  40
Columbus        80  67  84  67 /  40  30  60  50
Gainesville     73  64  81  64 / 100  20  30  50
Macon           82  66  87  66 /  80  30  50  50
Rome            75  61  84  65 /  90  20  40  40
Peachtree City  76  63  82  64 /  80  20  50  50
Vidalia         84  69  89  69 /  70  60  50  50




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