No watches are valid as of Wed Nov 11 20:04:02 UTC 2026.MD 2449 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR FAR EASTERN ILLINOIS INTO INDIANA AND KENTUCKY
Mesoscale Discussion 2449
NWS Storm Prediction Center Norman OK
0120 PM CST Wed Nov 11 2026
Areas affected...far eastern Illinois into Indiana and Kentucky
Concerning...Severe potential...Watch possible
Valid 111920Z - 112145Z
Probability of Watch Issuance...40 percent
SUMMARY...Storms will increase from eastern Illinois into Indiana
and into Kentucky through early evening. Areas of hail will be
likely, with isolated damaging gusts possible. A tornado cannot be
ruled out late in the day into early evening.
DISCUSSION...An upper trough will cold temperatures aloft continues
to move southeastward across the MS and OH Valleys, with a deepening
surface low now over central to east-central IL. Surface analysis
indicates up to 2 mb per hour pressure falls ahead of this low.
Meanwhile, daytime heating persists ahead of the low, with a plume
of 50s F dewpoints spreading northeastward out of MO/AR.
While instability is currently minimal, the combination of low-level
moisture advection with cooling temperatures aloft should favor
increasing instability and storm coverage/intensity later this
afternoon. Given such cold temperatures aloft, and expected cellular
storm mode, hail is likely, some over 1.00" diameter. Fast storm
motions and steepening lapse rates will also favor strong wind
gusts.
The tornado threat is non-zero, and dependent on low-level moisture
quality and storm mode. During the late afternoon into the early
evening, there appears to be a corridor of risk from southern IN
into KY, in closer proximity to the higher dewpoints, and as
low-level SRH possibly increases to 200 m2/s2 just ahead of the main
wind shift.
..Jewell/Mosier.. 11/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ILN...LMK...IND...PAH...LOT...ILX...
LAT...LON 39618826 39938829 40118837 40408823 40468762 40318659
40068580 39508528 38898507 38398506 37578571 37138667
37098745 37188805 37518843 37828852 38128843 38828830
39618826
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1030 AM CST Wed Nov 11 2026
Valid 111630Z - 121200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE LOWER OHIO AND WESTERN TENNESSEE VALLEYS...AS WELL AS ACROSS THE
EAST-CENTRAL FLORIDA PENINSULA...
...SUMMARY...
Thunderstorms capable of producing isolated hail, damaging winds,
and perhaps a tornado may occur this afternoon and evening across
parts of eastern Illinois into Indiana, western/central Kentucky,
and middle Tennessee. Isolated severe thunderstorms are also
possible across the east-central Florida Peninsula.
...Midwest/Lower Ohio Valley into Middle Tennessee...
Recent satellite imagery shows a lead shortwave trough moving into
northern IL, with another shortwave trough farther back northwest
moving into the Mid MO Valley. Showers and thunderstorms are ongoing
near the lead shortwave. Thunderstorm intensity has decreased over
the last half hour or so as these storms move into an environment
with less elevated buoyancy (as observed by the 12Z ILX sounding).
The lead shortwave is forecast to continue eastward into the OH
Valley while the second shortwave continues more southeastward into
the Lower OH Valley vicinity. The surface low currently over the
IA/IL border vicinity is forecast to progress eastward with the lead
wave while an attendant cold front sweeps southeastward through the
mid MS Valley/Mid-South, and lower OH Valley this afternoon and
evening.
Increasing low-level moisture is anticipated ahead of this front,
advecting northeastward into the region from the Ozarks/Mid-South
region. Recent surface analysis shows the mid 50s dewpoints are
still in northern AR, so there is some question as to how far
northeastward the greater low-level moisture will reach before
frontal passage. Current expectation is for the best overlap between
low-level moisture (and associated buoyancy) with the stronger
large-scale ascent will occur across southern IN and adjacent
western KY. Here, the combination of weak buoyancy (i.e. MLCAPE
around 500-800 J/kg) and 30-40 kt of deep-layer shear
oriented largely orthogonal to the surface cold front should support
a mix of bowing clusters and supercells. Isolated hail and damaging
gusts will be the primary risks. Hail is more likely with any more
cellular activity and damaging gusts more likely with any
fast-moving bowing segments. Modestly enhanced low-level
shear may also support a low-probability tornado risk, but a
tendency for low-level flow to veer to westerly should reduce
effective SRH with time through the late afternoon/evening. The
isolated severe risk should diminish with eastward extent this
evening across the lower OH Valley as front outruns the low-level
moisture and daytime heating wanes.
...Central/Southern Florida Peninsula...
Isolated to scattered thunderstorms are expected across the
central/southern FL Peninsula this afternoon. Glancing large-scale
ascent associated with a weak mid-level perturbation over the
Southeast should aid this convective development. A warm layer
around 700 mb could limit overall buoyancy, but 500 mb temperatures
will be around -9 to -11 deg C and most forecast sounding still show
1500+ J/kg of uninhibited MLCAPE this afternoon. Moderate deep-layer
shear will exists across the region as well. These conditions appear
supportive of marginally severe hail and gusty winds within the
stronger cores, which appear most probable along the east-central FL
Coast.
..Mosier/Halbert-K.. 11/11/2026
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0200 PM CST Wed Nov 11 2026
Valid 112000Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
CENTRAL/SOUTHERN INDIANA...WESTERN KENTUCKY...AND FAR SOUTHEASTERN
ILLINOIS...
...SUMMARY...
Thunderstorms capable of producing severe hail, damaging winds, and
perhaps a tornado are forecast this afternoon and evening across
parts of eastern Illinois into Indiana, western/central Kentucky,
and middle Tennessee. Isolated severe thunderstorms are also
possible across the east-central Florida Peninsula.
...20Z Update...
A Slight Risk was introduced for parts of central/southern IN,
western KY, and far southeastern IL -- driven by 15-percent hail and
wind probabilities. As lower 50s dewpoints (along/ahead of the cold
front) continue spreading eastward beneath steepening midlevel lapse
rates, a corridor of 500-1000 J/kg MLCAPE should support a gradual
increase in updraft intensity this afternoon into the evening. An
elongated hodograph (around 30-40 kt of effective shear) along with
increasing forcing for ascent should promote a mix of organized
clusters and perhaps supercell structures capable of producing
scattered severe hail (around 1-1.5 inches in diameter) and damaging
wind gusts. See MCD #2449 for more details.
..Weinman.. 11/11/2026
.PREV DISCUSSION... /ISSUED 1030 AM CST Wed Nov 11 2026/
...Midwest/Lower Ohio Valley into Middle Tennessee...
Recent satellite imagery shows a lead shortwave trough moving into
northern IL, with another shortwave trough farther back northwest
moving into the Mid MO Valley. Showers and thunderstorms are ongoing
near the lead shortwave. Thunderstorm intensity has decreased over
the last half hour or so as these storms move into an environment
with less elevated buoyancy (as observed by the 12Z ILX sounding).
The lead shortwave is forecast to continue eastward into the OH
Valley while the second shortwave continues more southeastward into
the Lower OH Valley vicinity. The surface low currently over the
IA/IL border vicinity is forecast to progress eastward with the lead
wave while an attendant cold front sweeps southeastward through the
mid MS Valley/Mid-South, and lower OH Valley this afternoon and
evening.
Increasing low-level moisture is anticipated ahead of this front,
advecting northeastward into the region from the Ozarks/Mid-South
region. Recent surface analysis shows the mid 50s dewpoints are
still in northern AR, so there is some question as to how far
northeastward the greater low-level moisture will reach before
frontal passage. Current expectation is for the best overlap between
low-level moisture (and associated buoyancy) with the stronger
large-scale ascent will occur across southern IN and adjacent
western KY. Here, the combination of weak buoyancy (i.e. MLCAPE
around 500-800 J/kg) and 30-40 kt of deep-layer shear
oriented largely orthogonal to the surface cold front should support
a mix of bowing clusters and supercells. Isolated hail and damaging
gusts will be the primary risks. Hail is more likely with any more
cellular activity and damaging gusts more likely with any
fast-moving bowing segments. Modestly enhanced low-level
shear may also support a low-probability tornado risk, but a
tendency for low-level flow to veer to westerly should reduce
effective SRH with time through the late afternoon/evening. The
isolated severe risk should diminish with eastward extent this
evening across the lower OH Valley as front outruns the low-level
moisture and daytime heating wanes.
...Central/Southern Florida Peninsula...
Isolated to scattered thunderstorms are expected across the
central/southern FL Peninsula this afternoon. Glancing large-scale
ascent associated with a weak mid-level perturbation over the
Southeast should aid this convective development. A warm layer
around 700 mb could limit overall buoyancy, but 500 mb temperatures
will be around -9 to -11 deg C and most forecast sounding still show
1500+ J/kg of uninhibited MLCAPE this afternoon. Moderate deep-layer
shear will exists across the region as well. These conditions appear
supportive of marginally severe hail and gusty winds within the
stronger cores, which appear most probable along the east-central FL
Coast.
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1130 AM CST Wed Nov 11 2026
Valid 121200Z - 131200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE MID ATLANTIC...
...SUMMARY...
A couple of damaging gusts or marginally severe hail may accompany
one of the stronger storms across the Mid-Atlantic tomorrow
(Thursday) afternoon.
...Synopsis...
A broad upper trough will overspread the eastern U.S. while an upper
ridge builds over the Rockies and pronounced mid-level impulse
impinges on the CA coastline tomorrow (Thursday). A surface low will
accompany the East Coast upper trough and traverse the Mid-Atlantic
during the day. A surface cold front will sweep across the
Mid-Atlantic, resulting in enough deep-layer ascent amid a
marginally buoyant airmass to support scattered thunderstorm
development, one or two of which may be severe. Surface high
pressure and a stable low-level airmass will usher in behind the
cold front over the most of the CONUS, limiting thunderstorm
development.
...Portions of the Mid-Atlantic...
A relatively cool low-level airmass (e.g. near 60 F surface
temperatures) is expected across the Mid-Atlantic given scattered to
widespread cloud cover and precipitation across the warm sector
preceding the low. Nonetheless, 7+ C/km mid-level lapse rates will
overspread mid 50s F surface dewpoints, amid minimal MLCINH,
yielding up to 500 J/kg MLCAPE. Though stronger 500 mb flow will
overspread VA into the Carolinas, strong enough southwesterly
mid-level wind fields will yield 40+ kts of effective bulk shear.
This low CAPE/moderate shear profile may support sustained
multicells and transient supercells capable of producing strong to
potentially damaging wind gusts and perhaps an instance of
marginally severe hail tomorrow afternoon.
..Squitieri.. 11/11/2026
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