Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Mon Apr 03 2023 03:33:18

AWUS01 KWNH 030333
FFGMPD
ALZ000-MSZ000-LAZ000-ARZ000-TXZ000-030900-

Mesoscale Precipitation Discussion 0152
NWS Weather Prediction Center College Park MD
1132 PM EDT Sun Apr 02 2023

Areas affected...Lower Mississippi Valley

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

Valid 030330Z - 030900Z

SUMMARY...Thunderstorms containing up to 2"/hr rainfall rates may
train over portions of the Lower MS Valley and could result in
areas of flash flooding.

DISCUSSION...A fast moving 500mb vorticity maxima is tracking east
and to the north of a warm front inching its way north through the
Lower MS Valley. At low levels, 40-45 knot 850mb winds out of the
SW will act as sufficient inflow and advect moisture directly into
the warm front. There is also 1000-1500 J/kg of MUCAPE in the warm
sector that is available along and south of the warm front. Storms
are moving at a good clip thanks to 40-50 knots worth of westerly
850-300mb mean wind speeds. That said, this steady 850mb inflow
will continue to intersect the warm front and lead to additional
thunderstorm development overnight. SPC mesoanalysis shows 40-50
knots worth of surface-6km shear, as well as 150-300 m2/s2 of
surface-1km SRH. These shear and helicity values will work to
maintain healthy organized convection into the overnight hours.

Hourly rainfall rates could approach 2"/hr in the most robust
convection. Some areas of northern LA, southern MS, and western AL
have received over 200% of normal rainfall in the past 7-days.
These areas are most vulnerable to potential flash flooding,
although the storms faster movements as mentioned above should
help keep flash flooding potential confined to more low lying,
poor drainage areas. With shear vectors oriented quasi-parallel to
the warm front, training thunderstorms across northern LA and into
central MS are possible. Flash flooding also has better odds of
occurring where training convection occurs. Lastly, urbanized
communities are also prone to areas of flash flooding given their
higher concentration of hydrophobic surfaces.

Mullinax

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!9PG3GDHPkGEIKbsXxV2tweNy61nnkqnKxEqdw8V-8i09dXVgfwr0Uq9x9dqUbdBZTvjj=
4yJGWicKBtQ7Kwwri0Swtbg$  for graphic product...

ATTN...WFO...BMX...JAN...LZK...MOB...SHV...

ATTN...RFC...LMRFC...SERFC...WGRFC...NWC...

LAT...LON   33739251 33719149 33628913 33138739 31618754=20
            31398909 31569130 31759251 32339411 33489403=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)

.