Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Wed Jul 12 2023 14:40:40

AWUS01 KWNH 121440
FFGMPD
ILZ000-IAZ000-122038-

Mesoscale Precipitation Discussion 0707
NWS Weather Prediction Center College Park MD
1039 AM EDT Wed Jul 12 2023

Areas affected...Northern Illinois

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

Valid 121438Z - 122038Z

Summary...Intense rain rates and localized heavy rainfall between
2-3" will be possible through the afternoon hours across portions
of northern Illinois. Flash flooding will be possible.

Discussion...Thunderstorms continue this morning along/north of a
stationary boundary draped across Iowa into Illinois, with a more
organized line of storms sweeping through central/eastern Iowa.
The latest mesoanalysis showed an axis of mainly elevated
instability upwards of 1000 J/kg extending across northern
Illinois while upwards of 1.25-1.5" of precipitable water is
available per the latest blended TPW product.

The leading edge convection should continue to expand in coverage
while the main organized line of storms to the west races to catch
up and converge. This will be aided by the increase in southerly
to southwesterly flow exceeding 30-35 kts at 850 mb, allowing an
increase in the PWs to above 1.5-1.75" while some increase in
instability is expected by afternoon.

The most recent runs of the HRRR and HREF neighborhood
probabilities suggest some localized totals of 2-3" with some
hourly totals approaching 1-1.5" at times. Some of this rainfall
will be over areas that have seen above normal rainfall over the
last 7 days and could lead to isolated/scattered instances of
flash flooding, particularly for more sensitive areas like urban
locations.

Taylor

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!-Gk2eXp6Mag2ZlVJq_Lng-tpjO4v4em7zTr3q_bF-_seexRPpdvhC1AdfJIJglonTM1n=
YlOUyWm6EQx0kc2eD_epG3g$  for graphic product...

ATTN...WFO...DVN...ILX...LOT...

ATTN...RFC...NCRFC...NWC...

LAT...LON   42428976 42408897 42328850 42138785 41498770=20
            40988785 40608844 40828973 41099057 41569112=20
            42299056=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)

.