RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1238 AM CDT Tue Mar 10 2026
Valid 101200Z - 111200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHERN
MISSOURI...ACROSS NORTHERN ILLINOIS INTO NORTHWEST INDIANA. AN
ENHANCED RISK IS ALSO FORECAST ACROSS PORTIONS OF THE TEXAS
PLAINS...
...SUMMARY...
Scattered severe thunderstorms are forecast on Tuesday from the
southern Plains into the southern Great Lakes vicinity. All severe
hazards are possible, including the risk for a few strong tornadoes
and very large hail.
...Southern Great Lakes...
Strong northern stream will gradually sag south across the northern
Rockies as a short-wave trough ejects across MT/WY. This feature is
forecast to advance into the eastern portion of the northern Plains
by 11/12z as a 90+kt 500mb speed max translates across northwest IA
into southern MN. Late timing of this feature is not particularly
conducive for assisting daytime convection downstream across
northern IL/IN region, as height falls will lag until the latter
half of the period. Even so, latest model guidance suggests a weak
surface low will evolve along the front and track across northern MO
into northwest IL by early evening, then toward southern Lake MI by
midnight.
Boundary-layer heating should prove instrumental in destabilization
ahead of the surface low and forecast soundings suggest convective
temperatures may be breached after 21z from northern MO into
northern IL. Strong deep-layer shear favors supercell development
and this activity will spread east, along/south of a warm front that
should extend across northern IL into southern MI. Temperature
gradient across this boundary will be sharp so any supercells that
spread north of the wind shift will quickly become elevated and pose
mainly a hail risk. Environmental conditions south of the front
should be characterized by MLCAPE in excess of 2500 J/kg with strong
0-3km SRH. Tornadoes and large hail are certainly possible with
warm-sector supercells. Parameters favor the potential for strong
tornadoes. This activity will spread east during the overnight
hours, possibly as far east as portions of northeast OH, as westerly
flow strengthens across this portion of the Great Lakes.
...Southern Plains...
Strong upper low is clearly evident on water-vapor imagery over the
central Baja Peninsula early this morning. This low is ejecting
east-northeast in line with latest model guidance and should advance
into north central Mexico by 18z, then into far west TX by early
evening as it begins to open up. Strong boundary layer heating will
be noted across northeast Mexico, north along the TX/NM border into
western KS. As a result, steep 0-3km lapse rates will develop ahead
of the approaching trough. Leading edge of large-scale ascent should
overspread the dry line around 21z and supercells should quickly
evolve as midlevel temperatures will cool quickly immediately ahead
of the trough. Very large hail is possible with initial supercell
development before strong forcing encourages a more linear evolution
and possible elongated MCS. Strong winds may accompany this squall
line.
Latest model guidance also suggests a weak disturbance may eject
well ahead of the primary low into south central TX. Deep convection
is possible ahead of this feature, but the primary concern will be
some hail and gusts.
..Darrow/Lyons.. 03/10/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Tue Mar 10 2026
Valid 111200Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE ARKLATEX
AND LOWER MISSISSIPPI VALLEY NORTHEAST THROUGH THE OHIO VALLEY AND
MID-ATLANTIC...
...SUMMARY...
Isolated to scattered severe thunderstorms are expected on Wednesday
from the ArkLaTex and Lower Mississippi Valley northeastward through
the Ohio Valley vicinity.
...ArkLaTex to Ohio Valley/Mid-Atlantic...
A messy scenario is evident heading into Wednesday from east Texas
northeast into PA/MD/VA. A northern stream upper trough will develop
east across the Great Lakes/Midwest, while a southern stream
shortwave trough moves across TX and the Lower MS Valley. A broad
swath of strong southwesterly deep layer flow will overspread these
areas, with a particularly strong jet max across the Ohio Valley
(80-100 kt at 500 mb). At the surface, a cold front will be oriented
from southern Lower MI into central OK Wednesday morning. A
dryline/Pacific front will then extend southward across east-central
TX. A surface cyclone is expected to deepen as it moves northeast
near the international border and Lower Great Lakes through
Wednesday evening. As this occurs, the surface cold front will
develop southeast, eventually overtaking the TX dryline during the
afternoon. This front will become oriented from the Mid-Atlantic
coast to the central Gulf coast by Thursday morning.
Ahead of the surface boundaries, a broad warm sector will be in
place, with surface dewpoints into the 60s F as far north as PA. The
strongest instability will likely be focused across the Lower MS
Valley where dewpoints into the mid/upper 60s F are possible and at
least some stronger surface heating will be possible. With northward
extent, instability will decrease, but MLCAPE up to 500-1000 J/kg
will be common across the Ohio Valley into VA. One of the main
concerns/points of uncertainty precluding higher probabilities
across the Ohio Valley vicinity is possible ongoing convection
during the morning, and multiple rounds of convection within the
broad warm advection regime limiting lapse rates/instability and
greater severe potential. Nevertheless, intense deep-layer
southwesterly flow will support damaging wind potential across a
broad area and an outlook upgrade was considered for parts of
southeast OH/northeast KY/southwest PA and western/northern WV. If
enough destabilization occurs and a strongly forced line of
convection develops, damaging gusts and a few tornadoes could occur.
Further south into the ArkLaTex and Lower MS Valley vicinity, a line
of convection is expected to be ongoing Wednesday morning.
Deep-layer flow will not be as strong compared to further north, but
still more than adequate for organized convection. Lapse rates are
forecast to remain modest, but linear convection along the surging
cold front will pose an all-hazards severe risk. Some forecast
guidance suggests discrete convection could develop ahead of the
line. If this occurs, some increased risk for tornadoes will
develop, especially as storms merge with the line. However,
confidence in this scenario is low. Depending on forecast trends,
outlook upgrades could become necessary in subsequent outlooks.
..Leitman.. 03/10/2026
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