Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Wed Jul 06 2022
Valid 091200Z - 141200Z
...DISCUSSION...
An upper trough over the Pacific Northwest should translate eastward
across the northern Rockies/Plains and Upper Midwest this upcoming
weekend. This feature is forecast to suppress a large-scale upper
ridge over the Plains and Southwest. Warm low/mid-level temperatures
associated with a substantial cap and preceding the upper trough
should act to inhibit convection across much of the northern Plains
through Day 4/Saturday afternoon. But, robust thunderstorms should
develop Saturday evening/night as large-scale ascent attendant to
the upper trough overspreads eastern MT into ND and vicinity. This
activity may also be aided by a strengthening southerly low-level
jet. Strong instability and deep-layer shear are forecast across
this region, and any thunderstorms that can develop should pose a
severe threat, with supercells possible. Have therefore introduced a
15% severe area across parts of the northern Plains for Saturday
where confidence is greater that thunderstorms will form.
An organized severe threat should continue across parts of the
northern Plains into the Upper Midwest on Day 5/Sunday. Enhanced
mid-level west-northwesterly winds should foster strong deep-layer
shear, and moderate to strong instability is forecast to develop
ahead of a cold front. Thunderstorms that are in progress Sunday
morning across portions of the northern Plains may continue
southeastward through the day, and additional robust convection may
develop along/ahead of the front Sunday afternoon/evening. A cap may
tend to limit the southwestward extent of severe potential into
central SD, NE, and IA. Still, the ascent associated with the
shortwave trough and cold front should support the maintenance
and/or development of severe thunderstorms into much of MN and
vicinity.
Some severe potential should persist into the early/middle portions
of next week as the upper trough continues southeastward across the
Midwest, Great Lakes, OH Valley, and eventually the eastern states.
However, there is currently too much uncertainty in the placement
and evolution of the upper trough and related surface features to
include any 15% severe areas from Day 6/Monday onward.
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