Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Wed Aug 23 2023 22:09:28

AWUS01 KWNH 232209
FFGMPD
PAZ000-WVZ000-OHZ000-240407-

Mesoscale Precipitation Discussion 0967
NWS Weather Prediction Center College Park MD
608 PM EDT Wed Aug 23 2023

Areas affected...northeastern/eastern Ohio, far western
Pennsylvania

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

Valid 232207Z - 240407Z

Summary...An organizing convective complex over southeastern
Ontario should impact the discussion area over the next several
hours, with flash flood potential especially centered over
northeastern Ohio through 03Z or so.

Discussion...An extensive MCS has maintained intensity near
London, Ontario over the past couple hours.  The storms were
oriented parallel to north-northwesterly steering flow aloft,
enabling areas of training and 1-1.5 inch/hr rain rates estimated
per MRMS.  Additionally, the storms were on the nose of a strong
(30-35 kt) westerly low-level jet over Michigan and collocated
with the eastern edge of steep mid-level lapse rates (7+ C/km
between 700-500mb), fostering strong updrafts.  The ongoing
scenario suggests a increasing flash flood threat for at least
northeastern Ohio (between Cleveland, Ashtabula, Akron, and
Youngstown) in the short term as it appears that 1 inch/hr rates
should materialize and persist over portions of the area over at
least the next 2-3 hours.

Some uncertainty exists with the overall flash flood scenario
through 04Z though.  On their current trek, storms should migrate
away from the steeper lapse rate plume over Lower Michigan and
away from the axis of focused convergence near Lake Erie with
time.  Additionally, models/CAMs suggest potential for upscale
growth and more forward propagation with time (as opposed to
currently observed training).  Latest thinking is that the flash
flood threat will likely maximize in northeastern Ohio over the
next 2-3 hours, with a lesser degree of training expected
thereafter.  Spots of 2-3 inch rainfall totals are possible in
northeastern Ohio through 04Z.  A somewhat lower flash flood risk
should exist with south-southeastward extent toward Pittsburgh
Metro/far northern West Virginia, with the expectation that less
intense storms and more forward propagation should result in
lighter overall totals in most areas.

Cook

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!__cSNAMNUNXFnuSOXSw7DNqOpwqVooHZdD0iKQ7baYY6tN89kWg6IfxmQ9CSh6SufOsJ=
T4X6GfkgnSwsoZKBNjkvTSs$  for graphic product...

ATTN...WFO...CLE...ILN...PBZ...RLX...

ATTN...RFC...OHRFC...NWC...

LAT...LON   42138039 40727999 39848035 39578184 40268246=20
            41478260=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)

.