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 4-8 Outlook
Day 4 - 8 Outlook
Day 4-8 Severe Weather Outlook. A depicted severe weather area indicates a 30% or higher probability for severe thunderstorms within 25 miles of a point.
D4Sun, Mar 31, 2024 - Mon, Apr 01, 2024 D7Wed, Apr 03, 2024 - Thu, Apr 04, 2024
D5Mon, Apr 01, 2024 - Tue, Apr 02, 2024 D8Thu, Apr 04, 2024 - Fri, Apr 05, 2024
D6Tue, Apr 02, 2024 - Wed, Apr 03, 2024 (All days are valid from 12 UTC - 12 UTC)
PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to:
  1. 1) large differences in the deterministic model solutions,
  2. 2) large spread in the ensemble guidance, and/or
  3. 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears highly unlikely during the entire period (e.g. less than a 30% probability for a regional severe storm area across the CONUS through the entire Day 4-8 period).

Images courtesy of the NWS Storm Prediction Center
 Forecast Discussion


000
ACUS48 KWNS 280902
SWOD48
SPC AC 280900

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0400 AM CDT Thu Mar 28 2024

Valid 311200Z - 051200Z

...DISCUSSION...
...Day 4/Sunday: Mid Mississippi Valley into the Central/Southern
Plains...
The upper trough/low over the western states should slowly advance
eastward towards the Southwest and southern/central High Plains on
Sunday. Upper ridging is forecast to remain over the central/
southern Plains through Sunday night, which in tandem with a
low-level temperature inversion should tend to suppress most
convection. One possible exception may be along a sharpening warm
front across MO/IL, where some guidance suggests elevated convection
may form either Sunday morning, and/or Sunday night with strong
low-level warm advection/lift occurring. Steepening mid-level lapse
rates are forecast to overspread the mid MS Valley from the
southwest through the period. These lapse rates, along with
increasing moisture/instability in the presence of strong deep-layer
shear, may support a risk for isolated supercells with associated
threat for large hail. Regardless, confidence remains too low in
this mainly elevated convection occurring, given upper ridging
persisting, to add a 15% severe area for Sunday along/near the warm
front in MO/IL at this time.

...Day 5/Monday: Southern/Central Plains into the Mid Mississippi
and Ohio Valleys...
Even though some differences remain in medium-range guidance
regarding the ejection of an upper trough over the central CONUS on
Monday, confidence has increased in the general location of relevant
surface features, including the primary low, position of a
southward-extending dryline, and northward extent of the warm front
into the OH Valley. Even though the overall upper trough orientation
may remain somewhat positively tilted, most deterministic guidance
shows that a mid-level speed max and associated shortwave trough
will eject northeastward over the southern/central Plains through
Monday evening. Low-level mass response should encourage the
eastward development of a surface low to the OK/KS vicinity in a
similar time frame. Favorable low-level trajectories emanating from
the Gulf will act to increase low-level moisture in tandem with
steepening mid-level lapse rates and daytime heating across a broad
warm sector extending from the southern/central Plains into the
lower/mid MS Valley and OH Valley.

A favorable thermodynamic and kinematic environment for organized
severe convection will exist across much of these regions, with
supercells capable of producing large hail and tornadoes possible
initially. With time Monday evening/night, some upscale growth seems
probable across the mid MS and OH Valleys, as mid-level flow should
become increasingly parallel to a surface cold front. Therefore, a
15% severe area has been introduced for Monday where confidence is
greatest that robust convection will develop in a parameter space
characterized by weak/moderate instability and strong deep-layer
shear. A nocturnal minimum in severe convective potential may be
realized Monday night into early Tuesday morning across parts of the
lower MS Valley into Mid-South, given the positively tilted nature
of the upper trough.

...Day 6/Tuesday: Ohio/Tennessee Valleys into the Appalachians...
Some severe threat should continue Tuesday over parts of the OH/TN
Valleys into the Appalachians as the upper trough continues
eastward. Even though there is still some uncertainty with the exact
placement of the primary surface low and evolution of the upper
trough, enough confidence exists in a fairly narrow corridor across
these regions to add a 15% severe area for Tuesday. Rich low-level
moisture should be in place ahead of an eastward-moving cold front.
Redevelopment and/or re-intensification of convection seems probable
by Tuesday afternoon. Strong deep-layer shear and weak instability
should be sufficient for organized severe convection posing some
threat for damaging winds, and perhaps tornadoes given the forecast
strength of a low-level jet focused over parts of the OH/TN Valleys.
The northward extent of the severe risk across OH and vicinity
remains uncertain, as the placement of the warm front varies in
model guidance. Similarly, convection should eventually encounter a
less unstable airmass across the Appalachians. But, an isolated
severe risk may continue Tuesday evening into early Wednesday
morning across the southern/central Appalachians into portions of
the Southeast.

...Day 7/Wednesday and Day 8/Thursday...
Predictability remains too low to include a 15% severe delineation
for Wednesday across the Mid-Atlantic/Southeast along/ahead of a
cold front. By this extended time frame, there are significant
differences in model guidance regarding the evolution of the upper
trough, including its possible interaction/merging with a
northern-stream trough, and placement of relevant surface features.
Still, at least an isolated severe risk may persist Wednesday
along/ahead of the eastward-sweeping cold front. Once this front
clears the East Coast, severe potential appears minimal across the
CONUS next Thursday.

..Gleason.. 03/28/2024