119
ACUS48 KWNS 110841
SWOD48
SPC AC 110840

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0340 AM CDT Fri Jul 11 2025

Valid 141200Z - 191200Z

...DISCUSSION...
A surface cold front across the southern Great Plains early in the
period will quickly redevelop northward into the northern Plains in
response to strong lee cyclogenesis across the northern High Plains.
This cyclogenesis will occur in response to a positive-tilt
short-wave trough moving through the broadly zonal mid-level flow
across the northern US.

This front will move back south during the period as a seasonably
strong high pressure builds southward into the central US in the
wake of the aforementioned short-wave trough. Thunderstorms are
likely to develop in the vicinity of the front/aggregate outflow
boundary each afternoon as it moves south. However, given the lack
of significant flow amplification as the mid-level wave crosses the
northern US, it is likely that thunderstorms will remain displaced
south of the requisite effective-layer shear needed to promote an
organized severe threat identifiable at this time range.

One exception to the idea that storms will be displaced from the
better shear may take place on Monday/Day-4 across portions of North
Dakota. Here, low-level moisture will surge northward in response to
the aforementioned northern High Plains lee cyclogenesis. Steep
mid-level lapse rates will overspread the northern Great Plains
during the day, yielding most-unstable CAPE values ranging from 1000
J/kg to perhaps 3000 J/kg depending on model guidance.

However, run-to-run inconsistency in the space and time evolution of
relevant features leads to little confidence in identifying where
any overlap of thunderstorms, instability, and effective-layer shear
might support severe thunderstorms. However, if model guidance
begins to converge on potential scenarios, probabilistic delineation
may become warranted in subsequent forecasts.

..Marsh.. 07/11/2025