RSS Mesoscale Discussions from Storm Prediction Center
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0752 AM CDT Tue May 05 2026
Valid 051300Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS CENTERED OVER
ARKANSAS AND EXTENDING FROM NORTHEAST TEXAS INTO WESTERN
TENNESSEE...
...SUMMARY...
Widely scattered severe storms are possible Tuesday afternoon into
Tuesday night from northeast Texas into western Tennessee, with the
main threat centered over Arkansas. The strongest storms will be
capable of large hail, damaging winds, and a few tornadoes. More
isolated strong to severe storms are possible across parts of the
Northeast.
...Northeast TX into the Mid-South...
Regional radar imagery shows a cluster of showers and thunderstorms
moving across central/northeast AR. Outflow associated with this
cluster stretches from north of LIT northwestward between FSM and
FYV into northeast OK. Surface analysis also places a low over
western OK. A cold front extends east-northeastward from this low
through far northeast OK and southern MO, and a dryline extends
southwestward from the low through the Permian Basin. These
boundaries, particularly the cold front and outflow boundary, could
act as a focal points for redevelopment as the airmass across the
region destabilizes amid heating and low-level moisture advection
this afternoon.
A combination of afternoon temperatures in the low 80s, dewpoints in
the mid 60s, and steep mid-level lapse rates will result in moderate
buoyancy (i.e. MLCAPE around 1500 to 2000 J/kg) within the warm
sector this afternoon. Convergence along the front will be modest
and large-scale height rises are anticipated. Some weak capping may
prevail as well, particularly if the current cloudiness persists.
These factors introduce notable uncertainty into the forecast,
particularly regarding overall storm coverage. Seemingly, these
factors should contribute to a widely scattered, but discrete, storm
mode. The placement and evolution of the outflow may become apparent
as heating begins, with observable trends in cloud cover possible as
well. These factors could potentially reveal a corridor of higher
storm coverage. However, confidence in the placement of such a
corridor is currently low, precluding the introduction of any higher
probabilities.
That being said, the kinematic environment should be very supportive
of supercells this afternoon/evening, with strong upper flow
resulting in bulk shear around 60 kt. Any storms that do mature
should be severe and capable of all hazards. Large to very large
hail (i.e. 2"+) is possible early in each storm's convective cycle.
Tornadoes are also possible, particularly from central AR into
western TN where the low/mid-level flow will be strongest. A strong
tornado is possible with a sustained discrete supercell. Storms may
eventually grow upscale into clusters, at which point damaging winds
would become the primary severe risk.
...Lower Great Lakes into northern New England...
Early morning surface analysis placed a low over southeast Lower MI,
along a cold front that extends from central Quebec southwestward
through southern IL. This low is forecast to progress northeastward
along the St. Lawrence Valley vicinity as the cold front also
progresses eastward in response to an eastward shift of the parent
cyclone from northern Ontario into northern Quebec. Modest low-level
moisture will advect northeastward into the Lower Great Lakes and
Northeast ahead of this cold front, with low 50s dewpoints likely
reaching as far north as ME. This low-level moisture coupled with
afternoon temperatures in the 70s will support modest buoyancy,
despite poor lapse rates. Thunderstorms are anticipated along and
ahead of the eastward-progressing front as it moves into the
destabilized airmass from the Lower Great Lakes into northern ME.
Strong deep-layer vertical will be in place, supported by relatively
deep southwesterly flow, suggesting the potential for organized
storm structures. However, this flow will be largely parallel to the
boundary, with a bowing linear mode expected to be dominant (as
shown by much of the convection-allowing guidance). Damaging gusts
will be possible with the strongest storms, although transient
updraft strength should keep the overall coverage and intensity
modest. Isolated hail is possible with a few storms as well.
Predominantly linear mode should keep the tornado risk low, although
a low-probability threat still exists, particularly if a pocket of
strong buoyancy can develop across Upstate NY.
..Mosier/Dean.. 05/05/2026
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