This is a multi-part message in MIME format...

------------=_1535460695-1928-6874
Content-Type: text/plain

ACUS11 KWNS 281251
SWOMCD
SPC MCD 281250
WIZ000-IAZ000-MNZ000-281445-

Mesoscale Discussion 1378
NWS Storm Prediction Center Norman OK
0750 AM CDT Tue Aug 28 2018

Areas affected...Northern Iowa and adjacent southern
Minnesota/southwestern Wisconsin

Concerning...Severe potential...Watch unlikely

Valid 281250Z - 281445Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated vigorous thunderstorm development could still
pose at least some severe hail threat into mid morning. Although it
still seems unlikely that a severe weather watch will be needed in
the near term, trends will continue to be monitored for an
increasing severe risk which could require one later this morning.

DISCUSSION...Isolated intense storm now approaching the Mason City
IA area still appears to be to the cool side of the southward
advancing front, but has come in closer proximity to the front, and
likely has been ingesting increasingly moist air emanating from the
pre-frontal boundary layer during the past hour or two. It appears
that this moisture may be supporting CAPE of 1500-2000+ J/kg, in the
presence of strong cloud-bearing layer shear, contributing to
convection capable of producing severe hail and perhaps strong
surface gusts.

At least some weakening of this storm appears ongoing, although it
is not clear whether this is a temporary fluctuation in intensity or
the onset of dissipation. Model output does suggest that supporting
mid-level warm advection may be in the process of weakening or
redeveloping northward, deeper into the cool air to the north of the
front. However, if the cell is able to maintain at least some
strength as it crosses to the warm side of the front, across
northeastern Iowa, re-intensification accompanied by increasing
severe weather potential might not be out of the question, as the
seasonably moist pre-frontal boundary layer begins to destabilize
through the 14-16Z time frame.

..Kerr/Edwards.. 08/28/2018

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DVN...ARX...MPX...DMX...

LAT...LON 43079450 43589316 43919219 43599116 42859112 42479213
42249397 42289438 42509461 43079450



------------=_1535460695-1928-6874
Content-Type: text/plain; charset="US-ASCII"
Content-Disposition: inline
Content-Transfer-Encoding: 7BIT

= = =
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. ------------=_1535460695-1928-6874--

--- SBBSecho 3.06-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)