NOAA Storm Prediction Center

Convective Outlooks

Convective Outlooks
The convective outlooks serve as guidance to the local NWS forecast offices and are used by emergency managers, private sector meteorologists, media, and other weather customers concerned with public safety. Three separate risk areas (slight, moderate, and high) are used to describe the expected coverage and intensity for the categorical severe weather threat on days 1-3 along with severe weather probabilities for the potential threat.

Day 1 Outlook Day 2 Outlook Day 3 Outlook Days 4-8 Outlook

Day 1 Outlook Convective Tornado
Hail Wind
Categorical Day1 1200Z Outlook
  
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 Forecast Discussion


000
ACUS01 KWNS 280536
SWODY1
SPC AC 280535

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1235 AM CDT Thu Sep 28 2023

Valid 281200Z - 291200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected today.

...Discussion...

Ohio Valley upper low is forecast to weaken during the day1 period
as it advances slowly toward the Middle Atlantic/upper OH Valley. As
this feature shifts east, northwesterly flow will increase across
portions of western KY/TN where 500mb flow should be on the order of
25kt. While mid-level heights will rise across this region, weak
instability is forecast to develop across the mid-South into western
KY along/ahead of a weak zone of low-level confluence. Latest model
guidance suggests ongoing/early-morning convection over KY will
shift east and south across the TN Valley. There is some concern
that a few robust updrafts may develop along the western fringe of
this early-day convection where northwesterly flow should
strengthen. However, low-level convergence should remain weak amidst
mid-level height rises. As a result, most of this convection may
struggle to organize despite modest shear.

Later tonight, low-level warm advection is expected to increase
across SD into MN in response to approaching short-wave trough. LLJ
should strengthen across western KS into southeast SD and elevated
convection is expected to develop after midnight along the nose of
the LLJ. NAM forecast sounding for ABR at 11z suggests a parcel
lifted near 750mb will be adequately buoyant for potentially robust
elevated updrafts. While some hail can not be ruled out with this
activity, the probability for hail greater than 1 inch does not
appear great enough to warrant severe probabilities at this time.

..Darrow/Moore.. 09/28/2023

$$