LIVE MAP (ABOVE) ... SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0200 PM CST Tue Nov 03 2026
Valid 032000Z - 041200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE LOWER
MS/TN VALLEYS INTO THE MID MS VALLEY...
...SUMMARY...
Thunderstorms with potential for isolated severe wind gusts and
perhaps a brief tornado or two will be possible this afternoon and
tonight from the Sabine and Lower Mississippi Valleys northward into
the Mid Mississippi Valley.
...Ark-La-Miss this afternoon into the TN Valley overnight...
Only minor adjustments to the outlook to reflect eastward
progression since mid morning. The primary midlevel trough is
pivoting northeastward toward IA, while an embedded speed max in the
base of the trough moves eastward toward the Ark-La-Miss. The
strongest storms have been focused in advance of the speed max and
along the north edge of the 70+ F boundary-layer dewpoints and
associated MLCAPE near or above 1000 J/kg (per mesoanalysis and the
18z LCH sounding). A few supercell structures and bowing segments
have been observed across northwest LA and this activity is expected
to spread eastward to the Ark-La-Miss through this evening.
Low-level flow/shear has likely peaked already in the warm sector
with a little weakening expected into this evening as the primary
shortwave trough moves northeastward away from the richer low-level
moisture. Still, there will be the potential for isolated wind
damage and a tornado or two with embedded circulations this
afternoon and continuing into tonight as weak buoyancy develops
eastward with additional moisture return toward the northwest AL
area.
...Mid MS Valley through this evening...
Buoyancy remains limited into the mid MS Valley as a result of poor
midlevel lapse rates and widespread clouds/rain. There is a narrow
corridor of surface heating on the nose of the dry slot from
northern MO into southern IA, where an isolated/low-topped supercell
may occur. Otherwise, embedded line segments with isolated wind
damage could occur into this evening, though the poor buoyancy
suggests this threat is on the lower margins for an outlook area.
..Thompson.. 11/03/2026
.PREV DISCUSSION... /ISSUED 1026 AM CST Tue Nov 03 2026/
... Synopsis ...
A midlevel cyclone over the southern Plains this morning will
continue to slowly deepen today as it lifts northeast toward the
upper Midwest. An associated surface cyclone over northeast Kansas
this morning will lift northeast into eastern Iowa during the day
before pivoting north then northwestward overnight as it occludes.
At the same time, an attendant surface baroclinic zone will push
east across the southern Plains today, with an appreciable moist
plume on the east side of the baroclinic zone.
Morning water vapor imagery shows a pronounced shortwave trough
entering the basal region of the longer-wave trough in which the
midlevel cyclone resides. As this shortwave trough exits the basal
region later today, it will take on an increasingly negative tilt
and southerly midlevel flow above the Lower and Mid-Mississippi
valleys will be sustained. In response to the evolving mid- and
upper-level kinematic fields, the low-level jet will be sustained
and move northeast, tied to the progress of the negatively tilted
trough.
... East Texas toward the Lower Mississippi Valley ...
Thunderstorms are ongoing this morning within the broad moist plume
ahead of the aforementioned baroclinic zone. Within this moist
plume, weak midlevel lapse rates and a modest low-level theta-e
airmass has held instability in check today -- generally less than
1000 J/kg. Given low-level moisture trajectories, widespread cloud
cover ahead of the advancing baroclinic zone, and weak lapse rates
upstream of the region, instability should not really recover much
today.
That said, low-level and large-scale forcing for ascent will
continue to support convection through the afternoon and into the
overnight hours. The strength of the kinematic fields will yield
some tornado/wind potential within the various convective bands --
especially where any low-level instability can develop.
Additionally, transient supercell or supercell-like thunderstorms
may develop ahead of the line within the broad warm-air advection
regime. These shallow, but rotating, thunderstorms will also pose at
least some potential for tornado/wind damage as well.
This threat should continue into the overnight hours across portions
of western Tennessee and western Kentucky, especially if a zone of
more discrete showers/thunderstorms can develop within the nocturnal
low-level jet.
... Mid-Mississippi Valley ...
As the surface-low deepens this afternoon and evening, strong
low-level wind fields will be maintained or even strengthen,
yielding ESRH on the order of 250-350 m2/s2. As strong southerly
midlevel flow is sustained in response to the approaching midlevel
shortwave trough, effective-layer shear in excess of 50 knots will
be maintained or overspread much of the region. This far north,
instability will be even more limited than compared to areas farther
south. However, convergence along the surface front and large-scale
ascent from the midlevel wave will support bands of forced
convection during the day and into the evening. The strong kinematic
fields may be sufficient to offset the meager buoyancy and support a
potential for isolated tornado/wind damage.
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