SPC Mesoscale Discussion
SPC MD 425
MD 0425 CONCERNING TORNADO WATCH 109... FOR PARTS OF NORTHEAST/EAST-CENTRAL IA...SOUTHWEST WI...AND FAR NORTHWEST IL
Mesoscale Discussion 0425
NWS Storm Prediction Center Norman OK
0342 PM CDT Tue Apr 14 2026
Areas affected...Parts of northeast/east-central IA...southwest
WI...and far northwest IL
Concerning...Tornado Watch 109...
Valid 142042Z - 142215Z
The severe weather threat for Tornado Watch 109 continues.
SUMMARY...A swath of very large to giant hail (3+ inches in
diameter) appears likely over the next couple hours, with a few
tornadoes also expected. The tornado risk will continue to increase
through the afternoon into this evening.
DISCUSSION...A dominant right-moving supercell has rapidly
intensified immediately south of a quasi-stationary surface front
extending across central IA, with additional storm splits evolving
along its northern flank. This storm has recent reports of a tornado
and 1.75 inch hail. Ahead of this storm, a strongly unstable air
mass (around 4500 J/kg SBCAPE per modified 18Z DVN special sounding)
and 50 kt of effective shear will favor continued intensification of
this storm and additional storms forming along its flanks and near
the surface boundary over the next few hours. Given a long/mostly
straight hodograph (per VWP data), splitting supercells with
dominant right-movers will pose a risk of very large to giant hail
(some 3+ inches in diameter) and a few tornadoes.
With time, low-level hodographs will increase in size/clockwise
curvature as a low-level jet strengthens through the afternoon into
the evening. This will support an increasing risk of strong to
intense tornadoes with any established semi-discrete supercells.
..Weinman.. 04/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MKX...DVN...ARX...DMX...
LAT...LON 42569317 42829282 42969226 43109053 42998994 42568984
42248999 42009121 42049267 42289310 42569317
MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN
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SPC MD 424
MD 0424 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF SOUTH-CENTRAL AND EASTERN NEBRASKA INTO EXTREME WESTERN IOWA
Mesoscale Discussion 0424
NWS Storm Prediction Center Norman OK
0253 PM CDT Tue Apr 14 2026
Areas affected...portions of south-central and eastern Nebraska into
extreme western Iowa
Concerning...Severe potential...Watch unlikely
Valid 141953Z - 142200Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated thunderstorm development is possible this
afternoon across portions of south-central Nebraska along a
stationary boundary, with a conditional threat for large hail and
severe wind gusts with any storm that can develop.
DISCUSSION...Latest surface analysis depicts a stationary boundary
extending northeast to southwest across eastern/south-central
Nebraska, with a surface low analyzed near OMA. A corridor of higher
surface dewpoints (low-to-mid 50s F) located along the cool side of
this boundary is contributing to 250-750 J/kg MLCAPE, with forecast
soundings and mesoanalysis depicting eroding MLCIN as surface
temperatures continue to warm. Despite only weak available buoyancy,
strong southwesterly flow aloft (40+ kt at 3 km AGL per the UEX VWP)
atop northeasterly surface flow on the cool side of the surface
boundary is supporting strong effective bulk shear of 50-60 kts.
Elongated hodographs and steep mid-level lapse rates (per the 18z
OAX observed sounding) will support a conditional threat for
isolated large hail with any storm that is able to develop, with
drier boundary layer profiles immediately south of the surface
boundary (DCAPE of 800-1000+ J/kg) also supporting some potential
for strong to occasionally severe wind gusts. This conditional
severe risk will gradually decrease with time this evening owing to
low-level nocturnal cooling/stabilization. Given the expectation for
storm coverage and threat magnitude to remain limited should a storm
even develop, watch issuance appears unlikely at this time.
..Chalmers/Gleason.. 04/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OAX...GID...
LAT...LON 40829690 40519813 40259897 40059957 40099990 40219996
40379976 40609948 40999900 41529800 41969701 41949630
41669589 41239583 41079603 40859677 40829690
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
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SPC MD 423
MD 0423 CONCERNING SEVERE POTENTIAL...TORNADO WATCH LIKELY FOR PORTIONS OF NORTHWEST TEXAS INTO CENTRAL OKLAHOMA AND SOUTHERN KANSAS
Mesoscale Discussion 0423
NWS Storm Prediction Center Norman OK
0239 PM CDT Tue Apr 14 2026
Areas affected...portions of northwest Texas into central Oklahoma
and southern Kansas
Concerning...Severe potential...Tornado Watch likely
Valid 141939Z - 142215Z
Probability of Watch Issuance...95 percent
SUMMARY...Severe thunderstorms expected to develop along a dryline
this afternoon will bring the potential for all severe hazards. A
Tornado Watch will be needed by 21z.
DISCUSSION...Latest surface analysis depicts a dryline extending
from eastern Kansas southwestward into northwest Oklahoma and the
southeastern Texas Panhandle. Enhanced southwesterly flow aloft
(40-50+ kts at 4-5 km AGL per regional VWPs) and modest ascent
preceding an approaching upper-level trough will overspread the warm
sector through the afternoon. Steep mid-level lapse rates (per the
12Z OUN/FWD/MAF soundings) atop surface temperatures in the low-80s
and dewpoints in the mid/upper-60s F are supporting strong
instability (MLCAPE 2500-3000+ J/kg) ahead of the dryline, with
convective initiation expected within the next 1-2 hours as
convective temperatures are reached.
35-45 kts of effective bulk shear (per latest mesoanalysis) will
support initial supercells, with very large to giant hail (up to 3-4
inches in diameter) likely given the aforementioned steep mid-level
lapse rates, ample buoyancy within the hail growth zone, and
elongated hodographs. A few tornadoes (some potentially strong) are
also possible, especially with any supercells that can remain
largely discrete into the evening hours when a strengthening
nocturnal low-level jet will yield enlarged, clockwise-curved
low-level hodographs. A Tornado Watch will be needed by 21z to cover
this threat.
Expectation is then for upscale growth to gradually occur with time
this evening, with a transition toward severe wind gusts as the
primary threat.
..Chalmers/Gleason.. 04/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TSA...TOP...ICT...OUN...
LAT...LON 34149793 33619861 33429920 33429958 33719984 34359992
34969976 35809926 36689849 37499774 38069716 38309660
38309618 38179544 37919519 37439517 36679571 35419683
34829735 34149793
MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN
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SPC MD 422
MD 0422 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF CENTRAL IL INTO NORTHERN/CENTRAL IN
Mesoscale Discussion 0422
NWS Storm Prediction Center Norman OK
0155 PM CDT Tue Apr 14 2026
Areas affected...Parts of central IL into northern/central IN
Concerning...Severe potential...Watch possible
Valid 141855Z - 142100Z
Probability of Watch Issuance...40 percent
SUMMARY...The area is being monitored for an increasing severe risk.
While confidence in overall storm development/coverage and evolution
remains uncertain, a watch issuance is possible this afternoon.
DISCUSSION...In the vicinity of a remnant/increasingly diffuse
outflow boundary draped across parts of northern/central IL, weak
low-level warm advection is promoting gradually deepening cumulus
and isolated convective initiation in central IL. Based on the
motion of these echoes and character of the cumulus on day cloud
phase imagery, this activity may be rooted above the boundary layer.
Nevertheless, temperatures climbing into the lower 80s amid
middle/upper 60s dewpoints will continue to erode inhibition at the
base of the EML and could eventually support a transition to
surface-based updrafts. If this were to occur, 2000-3000 J/kg MLCAPE
and 40-50 kt of effective shear (characterized by a long/mostly
straight hodograph) would initially favor discrete/semi-discrete
supercells and clusters -- with a risk of very large hail (some 2+
inches in diameter) and severe wind gusts. With time, a
strengthening low-level jet will result in enlarging
clockwise-curved hodographs (200-300 m2/s2 effective SRH) and an
increasing supercell-tornado risk.
With all that said, the limited/nebulous synoptic and mesoscale
ascent casts uncertainty on storm development/coverage and overall
evolution -- especially given lingering inhibition. Convective and
environmental trends are being monitored, and a watch issuance is
possible this afternoon.
..Weinman/Gleason.. 04/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...IWX...IND...LOT...ILX...LSX...DVN...
LAT...LON 39088910 39288995 39649033 40049057 40599064 41049034
41428980 41578728 41458650 41168587 40298545 39698564
39418603 39088910
MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
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SPC MD 421
MD 0421 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF THE TEXAS BIG BEND AND EDWARDS PLATEAU INTO NORTHWEST TEXAS
Mesoscale Discussion 0421
NWS Storm Prediction Center Norman OK
0124 PM CDT Tue Apr 14 2026
Areas affected...portions of the Texas Big Bend and Edwards Plateau
into Northwest Texas
Concerning...Severe potential...Watch likely
Valid 141824Z - 142100Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorms developing along/ahead of a dryline this
afternoon will pose a risk for large to very large hail and perhaps
a tornado or two. A watch will likely be needed within the next
couple of hours.
DISCUSSION...Latest regional radar imagery and GLM Flash data
indicate ongoing thunderstorm development across the Chisos
Mountains within the Texas Big Bend region. Additional thunderstorm
development is expected this afternoon along a dryline across much
of West Texas and across the Sierra del Carmen in northern Mexico.
Ahead of this dryline, surface temperatures in the low/mid-80s F and
dewpoints in the mid-60s F underneath steep mid-level lapse rates
are supporting 1500-2500 J/kg MLCAPE (locally greater). Effective
bulk shear of 35-45+ kts and straight, elongated hodographs will
support supercells (both left- and right-moving) capable of large to
very large hail of 2-3+ inches in diameter and severe wind gusts. A
gradually strengthening nocturnal low-level jet will likely support
at least some increase in the tornado threat later this evening,
especially with any persistent, discrete supercell(s); however, the
core of the low-level jet is forecast to be displaced farther to the
northeast. Thus, the magnitude of the tornado threat remains
somewhat uncertain at this time. Regardless, watch issuance will
likely be needed by 21z.
With time, some gradual upscale growth/clustering should occur with
ongoing storms, with an associated increase in the potential for
severe wind gusts.
..Chalmers/Gleason.. 04/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...EWX...SJT...LUB...MAF...
LAT...LON 29240278 29050292 28950320 29200328 29920317 31950219
32480174 32990115 33240047 33219980 33049926 32809907
32549902 31809967 31200022 30590082 30160132 29880156
29650193 29700241 29510262 29240278
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
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