Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Tue Jun 20 2023 19:04:52

AWUS01 KWNH 201904
FFGMPD
SCZ000-GAZ000-210100-

Mesoscale Precipitation Discussion 0540
NWS Weather Prediction Center College Park MD
304 PM EDT Tue Jun 20 2023

Areas affected...Central GA...Central SC

Concerning...Heavy rainfall...Flash flooding possible

Valid 201900Z - 210100Z

SUMMARY...Thunderstorms capable of producing torrential downpours
this afternoon and evening may cause flash flooding, particularly
in slow moving cells that track over areas with sensitive soils or
urbanized communities.

DISCUSSION...18Z surface analysis showed a pair of frontal
boundaries; one over central SC and the other in western GA with
an unstable air-mass and ample moisture residing within the warm
sector over central GA and central SC. 500mb analysis overlayed on
GOES-16 water vapor imagery depicted a vorticity maximum pushing
through central GA, which has helped to initiate thunderstorms
east of Macon. RAP mesoanalysis shows PWATs around 1.75", MLCAPE
between 1,500-2,000 J/kg, and mean 850-300mb winds between 5-10
knots. Vertical wind shear is lacking, forcing the most common
storm-mode to be "pulse" like. That said, the environmental
factors stated above combined with triggers in the form of two
frontal boundaries and outflow boundaries should result in
widespread thunderstorm activity capable of producing excessive
rainfall rates this afternoon.

12Z HREF showed as high as 30-40% probabilities for >2"/hr
rainfall rates, suggesting maximum hourly rates could reach as
high as 2.5"/hr. This is supported by the available PWATs and
instability, while the slower storm motions could also aid in
leading to rapid rainfall accumulations. Portions of central GA
have been wetter than normal the last 7 days, as evident by the
AHPS 7-day rainfall analysis showing 400-600% of normal amounts
south and west of Macon. Flash flooding is possible this afternoon
with sensitive soils, low lying spots, and urbanized communities
most at-risk.

Mullinax

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!5qTpw7k4-uw3doriPGhE7Zwvqvdt5MdYFu_JTU9PoRIBljczr_O3Fs60G1yoBVOC2M3W=
IoBKvJmWJp5IxB6qSPsCNqI$  for graphic product...

ATTN...WFO...CAE...CHS...FFC...GSP...

ATTN...RFC...SERFC...NWC...

LAT...LON   34488181 34068109 33368087 32458151 32348339=20
            32698436 33518432 33988386 34048338 34088273=20
=20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to
https://lists.illinois.edu and use the "Unsubscribe" link.  Otherwise email
Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.14-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

.