387
ACUS48 KWNS 080829
SWOD48
SPC AC 080828

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0328 AM CDT Mon Jul 08 2024

Valid 111200Z - 161200Z

...DISCUSSION...
Guidance consensus shows a mid-level trough de-amplifying over the
Northeast toward the end of the week as a pronounced mid-level ridge
builds over the CONUS this weekend into early next week. While
vertical wind profiles will remain weak overall across most of the
CONUS, strong mid-level flow associated with an embedded impulse
will pivot around the ridge and traverse the north-central CONUS
this weekend. Preceding this impulse will be a fetch of rich
low-level moisture beneath a plume of steep mid-level lapse rates
driven by the approach of an EML. Medium-range guidance agrees that
strong to extreme instability will develop ahead of the mid-level
impulse over the Upper MS Valley into the Great Lakes region.
However, substantial differences exist between the placement and
timing of the mid-level impulse and associated key surface features
(i.e. trough and boundaries). Given strong capping with the EML,
mesoscale forcing along low-level boundaries will likely be key to
initiating convection and supporting a severe threat.

With considerable uncertainty this far in advance, no severe
probabilities have been introduced. However, climatology suggests
that the aforementioned synoptic setup could support an appreciable
severe threat, including damaging-wind producing bow-echo MCSs. As
such, 15 percent probabilities may be introduced in future outlooks
for the upcoming weekend across portions of the Northern Plains into
the Great Lakes, if better model agreement in the timing of the
mid-level impulse, and associate surface boundaries, can be
achieved.

..Squitieri.. 07/08/2024