SPC Apr 13, 2025 2000 UTC Day 1 Convective Outlook

SPC 2000Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0253 PM CDT Sun Apr 13 2025

Valid 132000Z - 141200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms will be possible from the Upper Mississippi Valley to
the Great Lakes, and from the central Rockies to the lower Missouri
Valley through tonight. Severe thunderstorms are not expected.

...20z Update...
The prior forecast remains valid with only minimal changes to the
western edge of the Thunder area. Isolated thunderstorms ongoing
over parts of the Upper Midwest/Great Lakes should spread eastward
through tonight. Additional elevated thunderstorms will remain
possible across the OH Valley and Midwest as the low-level jet
increases overnight. Given limited moisture, instability is forecast
to remain too weak to support a severe threat. See the previous
discussion for more info.

..Lyons.. 04/13/2025

.PREV DISCUSSION... /ISSUED 1100 AM CDT Sun Apr 13 2025/

...Synopsis and Discussion...
A mid-level shortwave trough will move eastward from the northern
High Plains to the Upper Midwest by late tonight, as a surface low
develops northeastward from eastern NE/KS to the upper Great Lakes.
Limited low-level moisture return will continue through the period
within the warm sector of this cyclone. But, sufficient
ascent/saturation will likely remain confined to near the IA/MN
border this afternoon, where elevated thunderstorms are ongoing.
Some small hail may occur with this activity. This elevated
convection is expected to spread eastward over WI and parts of Lower
MI through the late evening.

Farther west, isolated thunderstorms will be possible this afternoon
into early evening along a southward-moving cold front across CO,
and overnight into MO where moistening and weak ascent atop the
front (near/above 700 mb) could support elevated convection by
09-12z. Across all these areas, instability is forecast to remain
too weak to support organized severe thunderstorms.

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