Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Wed Sep 06 2023 06:32:09

AWUS01 KWNH 060632
FFGMPD
TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-061030-

Mesoscale Precipitation Discussion 1040
NWS Weather Prediction Center College Park MD
231 AM EDT Wed Sep 06 2023

Areas affected...northern AR into southeastern MO and adjaucent MS
Valley

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

Valid 060630Z - 061030Z

Summary...A very localized flash flood threat will continue across
portions of northern AR into southeastern MO and the adjacent MS
Valley over the next 2-4 hours. Brief training of 1-2 in/hr rates
may produce localized 2-4 inch totals.

Discussion...Regional radar imagery at 06Z showed two small
clusters of thunderstorms over southern MO/northeastern AR,
propagating toward the ESE, each preceded by outflow. A small
bookend vortex was observed north of UNO with locally enhanced
southerly flow inferred just ahead, helping to support the recent
development of convection along the outflow boundary to the east,
extending from Shannon County into Bollinger County, MO. Given
west-east alignment of the low-level forcing with deeper layer
steering flow, some training of thunderstorms is likely in the
short term with rainfall rates of 1-2 in/hr for this region of
southeastern MO.

Farther south, southwesterly flow between 25-30 kt at 850 mb (KSRX
and KLZK VAD wind plots) may help to produce new thunderstorm
development over portions of northwestern AR over the next 1-2
hours within an environment characterized by MLCAPE near 2000
J/kg, PWATs near and above 1.8 inches (SPC mesoanalysis and GPS
measurements) and diffluent flow aloft. Whether new development
occurs upstream or not, short term training will be possible
anywhere convection is able to materialize/maintain on
southeastward sagging outflow that temporarily becomes aligned
with the mean steering flow, supporting 1-2 in/hr rain rates.
Localized storm totals of 2-4 inches may generate isolated flash
flooding, especially within locations of the discussion area that
have lowered FFG. Continued veering of the low level flow through
12Z per recent RAP forecasts, should limit the northward transport
of moisture atop rain cooled outflow, and diminish the flash flood
threat in the 10-12Z range for southern MO into northern portions
of AR.

Otto

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!_UIC3wKFwNWM0FmDFCxpBzRxx-bV7x9WDIJ6Epa4O8FWi54NNVvTGgBi6pXp_8bZyKB3=
-MDfxpZS7NhsKIbcpbXKwTc$  for graphic product...

ATTN...WFO...LSX...LZK...MEG...PAH...SGF...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...NWC...

LAT...LON   37619097 37598988 37298931 36938924 36428934=20
            35838978 35299147 35059301 35009423 35859448=20
            36299375 36499282 36799237 37429181=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)

.