Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0755 AM CDT Wed Oct 20 2021

Valid 201300Z - 211200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE UPPER
MIDWEST...

...SUMMARY...
Thunderstorms with isolated severe hail are possible today across
northern Iowa and southern Minnesota, primarily this morning into
early/mid-afternoon.

...Midwest including northern Iowa/southern Minnesota...
Immediately ahead of an eastward-moving upper low, early morning
convection has exhibited a modest uptick in coverage and intensity
in the pre-dawn hours across far northeast Nebraska and northwest
Iowa into far southwest Minnesota. For additional short-term
details, see Mesoscale Discussion 1877. Steep mid-level lapse rates
(12Z Omaha observed sounding) and sufficient elevated instability
(upwards of 1000 J/kg MUCAPE) may support some storms capable of
hail today as this activity spreads northeastward across northern
Iowa/southern Minnesota.

Farther south across the middle Mississippi Valley, substantial
convective inhibition will likely inhibit surface-based storms along
and ahead of the cold front, although moistening near 850 mb may
support some slightly elevated convection. The potential for
severe-caliber hail/wind is expected to remain very limited today.

...Lower Michigan and far northern Indiana/northwest Ohio...
Thunderstorms are expected to develop this evening into the
overnight, particularly across Lower Michigan. This convection will
be rooted atop a stable boundary, with modest elevated instability
(MUCAPE generally 500-750 J/kg) supportive of thunderstorms. This
could include some potential for hail, but current thinking is that
the risk for severe-caliber hailstones should remain low given the
modest overall buoyancy.

...Middle Gulf Coast...
Relatively rich low-level moisture will stream northward into
portions of Louisiana and southern Mississippi/southwest Alabama
during the day today, along the western periphery of a surface ridge
over the Southeast CONUS. As this occurs, moderate buoyancy will
support scattered thunderstorms near the coast this morning, with
convection expected to spread further inland with time by afternoon.
While weakly veering wind profiles may favor some organization with
the strongest storms, poor mid-level lapse rates and generally
modest low/mid-level flow should tend to limit the severe risk in
this area, although a few instances of small hail and gusty winds
cannot be ruled out.

..Guyer/Leitman.. 10/20/2021

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1126 AM CDT Wed Oct 20 2021

Valid 201630Z - 211200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE UPPER MIDWEST...

...SUMMARY...
Thunderstorms with isolated severe hail are possible today across
northern Iowa and southern Minnesota, primarily through
mid-afternoon.

...Midwest including northern Iowa/southern Minnesota...
Upper-level low near the NE/SD border will lift east/northeast
towards the Great Lakes region through tonight. An associated
surface low and cold front will move east towards lower MI/OH Valley
as a warm front extends from southern MN/central WI/northern lower
MI. In advance of the cold front, lower-mid 50s dew points remain
prevalent and will contribute to modest buoyancy in the presence of
35-45 kts effective shear. A stronger storm or two within the
Marginal Risk area will have some potential for hail that could
approach severe thresholds through early/mid afternoon.

...Lower Michigan and far northern Indiana/northwest Ohio...
Thunderstorms are expected to develop this evening into the
overnight, primarily across Lower Michigan, aided by ascent within
the left exit region of an approaching 250-mb jet maximum. This
convection will be rooted atop a stable boundary layer, with modest
elevated instability (MUCAPE generally 500-750 J/kg) supportive of
thunderstorms. This may include some potential for hail, but current
thinking remains that the risk for severe-caliber hailstones should
remain low given the modest buoyancy.

...Middle Gulf Coast...
Relatively rich low-level moisture will stream northward into
portions of Louisiana and southern Mississippi/southwest Alabama
during the day today, supporting moderate buoyancy this afternoon. 
Modestly veering wind profiles may favor some organization with
a few stronger storms developing within an environment with
negligible CINH, however poor mid-level lapse rates and generally
modest low/mid-level flow should tend to limit the severe risk in
this area. Still, a few instances of small hail and gusty winds
cannot be ruled out.

..Bunting/Lyons.. 10/20/2021

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1005 AM CDT Wed Oct 20 2021

Valid 201700Z - 211200Z

...NO CRITICAL AREAS...

The forecast remains on track. Morning surface observations show
gusty winds in the wake of a cold front across the central Plains.
However, cool temperatures are supporting high RH, which will
largely be maintained through the day as modest cold air advection
continues. Localized elevated conditions may evolve within the
higher terrain of the southern Rockies and perhaps southern Great
Basin, but will remain too brief and localized for highlights.

..Moore.. 10/20/2021

.PREV DISCUSSION... /ISSUED 1151 PM CDT Tue Oct 19 2021/

...Synopsis...
A shortwave trough will move from the Mid-Missouri Valley into the
Upper Midwest today. In the West, low-amplitude ridging will build.
At the surface, a cold front will progress to near the Ohio Valley,
arcing southwestward into the southern Plains. Warm and dry
conditions are likely in parts of the Great Basin and Southwest.
Fire weather concerns across the CONUS appear minimal through the
period as light winds and poorly receptive fuels are expected where
the driest conditions are forecast.

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