WW 109 TORNADO IA IL MN WI LM 141930Z - 150300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 109
NWS Storm Prediction Center Norman OK
230 PM CDT Tue Apr 14 2026
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Central and Eastern Iowa
Northern Illinois
Extreme Southeast Minnesota
Southern Wisconsin
Lake Michigan
* Effective this Tuesday afternoon and evening from 230 PM until
1000 PM CDT.
* Primary threats include...
Several tornadoes and a couple intense tornadoes likely
Widespread large hail and scattered very large hail events to 4
inches in diameter likely
Scattered damaging winds likely with isolated significant gusts
to 75 mph possible
SUMMARY...Supercell thunderstorms will pose a threat for very large
to giant hail this afternoon and evening as they track eastward,
with the largest hailstones potentially reaching up to 3-4 inches in
diameter. The threat for several tornadoes will increase later this
afternoon and evening along a warm front, and any sustained
supercell will be capable of producing a strong tornado. Otherwise,
scattered to numerous severe/damaging winds may eventually occur as
thunderstorms consolidate into one or more bowing clusters, with
peak gusts up to 65-75 mph.
The tornado watch area is approximately along and 75 statute miles
north and south of a line from 60 miles west southwest of Waterloo
IA to 20 miles north northeast of Milwaukee WI. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU9).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 108...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 4 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 26035.
...Gleason
WW 108 SEVERE TSTM CT MA NY PA VT 141850Z - 150200Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 108
NWS Storm Prediction Center Norman OK
250 PM EDT Tue Apr 14 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northwest Connecticut
Western Massachusetts
New York
Far Northeast Pennsylvania
Southern Vermont
* Effective this Tuesday afternoon and evening from 250 PM until
1000 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...Thunderstorms should continue to increase in coverage and
intensity while posing a threat for mainly scattered damaging winds.
Peak gusts could reach up to 60-70 mph. Isolated hail and perhaps a
tornado or two may occur with any supercells along/near a front in
northern New York/southern Vermont.
The severe thunderstorm watch area is approximately along and 80
statute miles east and west of a line from 35 miles north of Glens
Falls NY to 25 miles west southwest of Monticello NY. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU8).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
27040.
...Gleason
WW 0109 Status Updates
STATUS FOR WATCH 0109 HAS NOT BEEN ISSUED YET
WW 0108 Status Updates
STATUS REPORT ON WW 108
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..WEINMAN..04/14/26
ATTN...WFO...ALY...BGM...BUF...BTV...
STATUS REPORT FOR WS 108
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
CTC005-142040-
CT
. CONNECTICUT COUNTIES INCLUDED ARE
LITCHFIELD
MAC003-142040-
MA
. MASSACHUSETTS COUNTIES INCLUDED ARE
BERKSHIRE
NYC001-007-011-015-017-021-023-025-027-035-039-041-043-053-057-
065-067-077-083-091-093-095-097-099-101-105-107-109-111-113-115-
123-142040-
NY
. NEW YORK COUNTIES INCLUDED ARE
ALBANY BROOME CAYUGA
CHEMUNG CHENANGO COLUMBIA
CORTLAND DELAWARE DUTCHESS
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
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
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
MD 0419 CONCERNING SEVERE POTENTIAL...TORNADO WATCH LIKELY FOR PARTS OF CENTRAL/EASTERN IA...SOUTHERN WI...AND NORTHERN IL
Mesoscale Discussion 0419
NWS Storm Prediction Center Norman OK
1256 PM CDT Tue Apr 14 2026
Areas affected...Parts of central/eastern IA...southern WI...and
northern IL
Concerning...Severe potential...Tornado Watch likely
Valid 141756Z - 142000Z
Probability of Watch Issuance...95 percent
SUMMARY...The risk of supercells capable of producing several
tornadoes (some strong to intense), giant hail, and severe wind
gusts will increase by around 19-22Z. A tornado watch is likely
within the next couple hours.
DISCUSSION...The latest surface analysis depicts a quasi-stationary
boundary extending from central/northern IA into southern/central
WI, with an additional composite outflow boundary farther south from
northeast IA into northern IL. Over the next few hours, continued
diurnal heating of a moist air mass (upper 60s dewpoints) should
erode remaining inhibition at the base a substantial EML, resulting
in the development of strong surface-based buoyancy (upwards of
3000-3500 J/kg MLCAPE). As this occurs, initial thunderstorm
development is expected across parts of central/eastern IA near the
intersecting boundaries by around 19-22Z -- aided by a subtle
frontal wave tracking eastward along the quasi-stationary boundary.
The strongly unstable air mass coupled with 40-50 kt of effective
shear will favor rapid thunderstorm organization/intensification
into semi-discrete supercells and organized clusters. Initially,
very large to giant hail (2-3+ inches in diameter) and severe wind
gusts will be the main concern with potentially splitting supercells
-- given a mostly straight hodograph. However, a south-southwesterly
low-level jet will strengthen across the area later this afternoon
into the evening and likely favor a transition to dominant
right-moving supercells with a quickly increasing tornado risk. The
strong buoyancy and 200-300+ m2/s2 effective SRH will support strong
to intense tornadoes with any longer-lived supercells, along with a
continued risk of giant hail and severe gusts. Eventually,
thunderstorms may have a tendency of growing upscale into clusters
with eastward extent, which will yield an increasing risk of
damaging wind swaths.
A tornado watch will be issued within the next couple hours.
..Weinman/Gleason.. 04/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LOT...MKX...DVN...ARX...DMX...
LAT...LON 41219309 41419361 41849390 42349386 42679350 43349177
43819045 43798943 43548877 42948850 42438870 41938916
41309166 41219309
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
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1130 AM CDT Tue Apr 14 2026
Valid 141630Z - 151200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MIDWEST/SOUTHERN GREAT LAKES AND SOUTHERN/CENTRAL PLAINS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHEAST...
...SUMMARY...
Severe thunderstorms are expected this afternoon through tonight
from the southern Plains into the Midwest. Large to giant hail,
several tornadoes (some strong), and swaths of severe/damaging gusts
are all likely, particularly from Iowa into the southern Great
Lakes.
...Synopsis...
An active severe weather day is anticipated for much of the
southern/central Plains into the Midwest/Great Lakes and parts of
the Northeast. The primary upper trough centered over the Four
Corners late this morning will eject east-northeastward towards the
southern/central Plains by this evening, while a separate mid-level
shortwave trough over the northern Plains/Upper Midwest will also
move east-northeastward across the Upper Great Lakes into Ontario.
Another convectively enhanced low-amplitude shortwave trough will
also develop eastward across the Lower Great Lakes into the
Northeast.
Recent surface analysis indicates multiple surface lows, with one
over southern Ontario and another over southeast NE/northeast KS. A
seasonably rich/moist low-level airmass exists to the south of a
front extending between these two lows, with surface dewpoints
already in the low to mid 60s across much of the southern/central
Plains to the east of a dryline. Both the dryline in the
southern/central Plains and developing warm front in the
Midwest/southern Great Lakes will likely serve as foci for intense
thunderstorms this afternoon and evening, including the potential
for several supercells.
...Midwest/Ohio Valley/Great Lakes...
A complex scenario for severe thunderstorms remains apparent across
the Midwest/OH Valley into the southern Great Lakes today, with
multiple outflow boundaries from earlier convection rendering
greater than usual uncertainty with the southward extent of possible
thunderstorm development in IL/IN/OH. In general, continued
low-level warm advection from the central Plains into the Midwest/OH
Valley will support a moistening/destabilizing airmass through the
afternoon as a northern-stream shortwave trough moves eastward
across the Upper Midwest. A surface warm front will extend
northeastward from a weak surface low in IA across southern WI and
Lower MI. It still appears likely that multiple intense supercells
will develop by 20-21Z along/near this boundary in IA/southern
WI/northern IL in a very favorable airmass for significant severe
hail given strong deep-layer shear and the presence of steep
mid-level lapse rates. Low-level shear is expected to gradually
strengthen through the evening in tandem with a modestly increasing
south-southwesterly low-level jet.
Any supercells than can remain on the warm/south side of the front
will be capable of producing tornadoes, a few of which could be
strong (EF-2/3). Some consideration was given to including greater
tornado probabilities and a Moderate Risk (level 4 of 5) focused
across southern WI/far northern IL. But, convection may have a
tendency to grow upscale fairly quickly this evening, so confidence
was not high enough for a categorical upgrade at this time.
Regardless, very large to giant hail (potentially up to 3-4 inches
in diameter) will be a threat with sustained supercells, and a swath
of severe/damaging winds appears likely with a convective cluster
spreading eastward across southern Lower MI this evening into
tonight.
A somewhat separate area of severe potential should also exist
farther south across central IL into IN/OH this afternoon and
evening. Greater low-level moisture and related instability are
expected to exist across these areas compared to locations farther
north. While large-scale forcing should remain fairly weak/nebulous
across this region, a remnant outflow boundary may provide a focus
for supercell development across central IL into IN by 20-21Z. Have
expanded the Slight Risk for large hail, damaging winds, and perhaps
a few tornadoes southward across these areas to account for this
still somewhat uncertain potential.
...Southern/Central Plains...
12Z observed soundings from DRT/MAF/FWD/OUN/TOP show the presence of
steep mid-level lapse rates atop rich low-level moisture (generally
14-15 g/kg mean mixing ratios) along/east of the surface dryline.
Southwesterly mid-level flow and modest ascent preceding the upper
trough over the Southwest/southern Rockies will gradually overspread
the warm sector by mid to late afternoon. Moderate to strong
instability (MLCAPE around 2000-3000 J/kg, locally stronger
possible) and 35-45 kt of deep-layer shear will support multiple
intense supercells. Explosive convective initiation across parts of
western OK into south-central/southeast KS is expected by 20-21Z as
lingering MLCIN erodes with filtered daytime heating and as
convective temperatures are breached.
The overall thermodynamic and kinematic environment appears quite
favorable for very large to potentially giant hail (up to 3-4 inches
in diameter) with any supercells that spread east-northeastward
through the afternoon/evening. A gradually strengthening low-level
jet across OK/KS by 00Z will also support a threat for a few
tornadoes, a couple of which could be strong as low-level hodographs
become enlarged. Gradual upscale growth/clustering should occur with
time through the evening, with some risk for severe/damaging winds.
The Enhanced Risk has been expanded a bit northeastward into
south-central/southeast KS for a focused severe wind corridor.
Farther south along the length of the dryline in TX, isolated to
scattered supercells may develop this afternoon and evening, with a
risk for mainly large to very large hail and occasional severe
gusts.
...Northeast...
Ongoing convection across southern Ontario and the Lower Great Lakes
will continue to track eastward this afternoon into NY and parts of
New England in tandem with a low-amplitude shortwave trough. Gradual
clearing of low/mid-level clouds has already encouraged surface
temperatures to warm into the 70s along/south of west-east oriented
front. Thunderstorms are expected to gradually increase in coverage
and intensity as weak to locally moderate instability and strong
deep-layer shear support organized updrafts, including the potential
for some supercells initially. The greatest severe risk will
probably be scattered damaging winds given a tendency for convection
to consolidate into one or more clusters. But, an isolated severe
hail threat may exist with any sustained supercell, along with some
chance for a tornado or two near the front where low-level shear
will be locally enhanced.
..Gleason/Chalmers.. 04/14/2026
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0236 PM CDT Tue Apr 14 2026
Valid 142000Z - 151200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MIDWEST/SOUTHERN GREAT LAKES AND SOUTHERN/CENTRAL PLAINS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHEAST...
...SUMMARY...
Severe thunderstorms are expected this afternoon through tonight
from the southern Plains into the Midwest. Large to giant hail,
several tornadoes (some strong), and swaths of severe/damaging gusts
are all likely, particularly from Iowa into the southern Great
Lakes.
...20Z Update...
A complex yet active severe weather day remains in the forecast for
portions of the Midwest-OH Valley into the Southern Plains this
afternoon into early tonight. While several lines were slightly
adjusted to account for the latest guidance consensus, the following
substantial changes and/or decisions were made:
1.) 30 percent wind probabilities were expanded southwestward into
southwest and central OK to account for the possibility of more
rapid upscale growth into one or more wind-producing MCSs or linear
segments.
2.) Category 1/Marginal Risk probabilities for severe wind and hail
were expanded west-southwest into NE along a frontal boundary to
account for two possible scenarios. First, an isolated strong storm
may develop within the next few hours along the boundary as a
consequence of strong diurnal heating. Second, late tonight, there
is low potential for gravity-wave associated convection on the
immediate cool side of the frontal boundary, atop a stable boundary
layer.
3.) Confidence is still too low for supercells across the Midwest to
remain discrete for long periods of time, which would warrant a
Categorical Moderate risk upgrade. Nonetheless, should a dominant
supercell become sustained and discrete for at least a few hours,
especially along the warm front over northeast IA into southern WI,
a sustained and intense tornado will be possible.
The rest of the forecast (see below) remains on track.
..Squitieri.. 04/14/2026
.PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Apr 14 2026/
...Synopsis...
An active severe weather day is anticipated for much of the
southern/central Plains into the Midwest/Great Lakes and parts of
the Northeast. The primary upper trough centered over the Four
Corners late this morning will eject east-northeastward towards the
southern/central Plains by this evening, while a separate mid-level
shortwave trough over the northern Plains/Upper Midwest will also
move east-northeastward across the Upper Great Lakes into Ontario.
Another convectively enhanced low-amplitude shortwave trough will
also develop eastward across the Lower Great Lakes into the
Northeast.
Recent surface analysis indicates multiple surface lows, with one
over southern Ontario and another over southeast NE/northeast KS. A
seasonably rich/moist low-level airmass exists to the south of a
front extending between these two lows, with surface dewpoints
already in the low to mid 60s across much of the southern/central
Plains to the east of a dryline. Both the dryline in the
southern/central Plains and developing warm front in the
Midwest/southern Great Lakes will likely serve as foci for intense
thunderstorms this afternoon and evening, including the potential
for several supercells.
...Midwest/Ohio Valley/Great Lakes...
A complex scenario for severe thunderstorms remains apparent across
the Midwest/OH Valley into the southern Great Lakes today, with
multiple outflow boundaries from earlier convection rendering
greater than usual uncertainty with the southward extent of possible
thunderstorm development in IL/IN/OH. In general, continued
low-level warm advection from the central Plains into the Midwest/OH
Valley will support a moistening/destabilizing airmass through the
afternoon as a northern-stream shortwave trough moves eastward
across the Upper Midwest. A surface warm front will extend
northeastward from a weak surface low in IA across southern WI and
Lower MI. It still appears likely that multiple intense supercells
will develop by 20-21Z along/near this boundary in IA/southern
WI/northern IL in a very favorable airmass for significant severe
hail given strong deep-layer shear and the presence of steep
mid-level lapse rates. Low-level shear is expected to gradually
strengthen through the evening in tandem with a modestly increasing
south-southwesterly low-level jet.
Any supercells than can remain on the warm/south side of the front
will be capable of producing tornadoes, a few of which could be
strong (EF-2/3). Some consideration was given to including greater
tornado probabilities and a Moderate Risk (level 4 of 5) focused
across southern WI/far northern IL. But, convection may have a
tendency to grow upscale fairly quickly this evening, so confidence
was not high enough for a categorical upgrade at this time.
Regardless, very large to giant hail (potentially up to 3-4 inches
in diameter) will be a threat with sustained supercells, and a swath
of severe/damaging winds appears likely with a convective cluster
spreading eastward across southern Lower MI this evening into
tonight.
A somewhat separate area of severe potential should also exist
farther south across central IL into IN/OH this afternoon and
evening. Greater low-level moisture and related instability are
expected to exist across these areas compared to locations farther
north. While large-scale forcing should remain fairly weak/nebulous
across this region, a remnant outflow boundary may provide a focus
for supercell development across central IL into IN by 20-21Z. Have
expanded the Slight Risk for large hail, damaging winds, and perhaps
a few tornadoes southward across these areas to account for this
still somewhat uncertain potential.
...Southern/Central Plains...
12Z observed soundings from DRT/MAF/FWD/OUN/TOP show the presence of
steep mid-level lapse rates atop rich low-level moisture (generally
14-15 g/kg mean mixing ratios) along/east of the surface dryline.
Southwesterly mid-level flow and modest ascent preceding the upper
trough over the Southwest/southern Rockies will gradually overspread
the warm sector by mid to late afternoon. Moderate to strong
instability (MLCAPE around 2000-3000 J/kg, locally stronger
possible) and 35-45 kt of deep-layer shear will support multiple
intense supercells. Explosive convective initiation across parts of
western OK into south-central/southeast KS is expected by 20-21Z as
lingering MLCIN erodes with filtered daytime heating and as
convective temperatures are breached.
The overall thermodynamic and kinematic environment appears quite
favorable for very large to potentially giant hail (up to 3-4 inches
in diameter) with any supercells that spread east-northeastward
through the afternoon/evening. A gradually strengthening low-level
jet across OK/KS by 00Z will also support a threat for a few
tornadoes, a couple of which could be strong as low-level hodographs
become enlarged. Gradual upscale growth/clustering should occur with
time through the evening, with some risk for severe/damaging winds.
The Enhanced Risk has been expanded a bit northeastward into
south-central/southeast KS for a focused severe wind corridor.
Farther south along the length of the dryline in TX, isolated to
scattered supercells may develop this afternoon and evening, with a
risk for mainly large to very large hail and occasional severe
gusts.
...Northeast...
Ongoing convection across southern Ontario and the Lower Great Lakes
will continue to track eastward this afternoon into NY and parts of
New England in tandem with a low-amplitude shortwave trough. Gradual
clearing of low/mid-level clouds has already encouraged surface
temperatures to warm into the 70s along/south of west-east oriented
front. Thunderstorms are expected to gradually increase in coverage
and intensity as weak to locally moderate instability and strong
deep-layer shear support organized updrafts, including the potential
for some supercells initially. The greatest severe risk will
probably be scattered damaging winds given a tendency for convection
to consolidate into one or more clusters. But, an isolated severe
hail threat may exist with any sustained supercell, along with some
chance for a tornado or two near the front where low-level shear
will be locally enhanced.
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1238 PM CDT Tue Apr 14 2026
Valid 151200Z - 161200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
NORTHERN TEXAS AND OKLAHOMA NORTHEASTWARD INTO SOUTHERN
WISCONSIN...AND FROM NORTHERN OHIO INTO PENNSYLVANIA...
...SUMMARY...
Severe thunderstorms posing a risk for large hail, strong wind
gusts, and a couple of tornadoes will be possible across portions of
the southern Plains toward the Great Lakes Wednesday afternoon and
evening.
...Synopsis...
A positive-tilt upper trough will be located over the central Plains
on Wednesday and will move across the MS Valley and toward the Great
Lakes late. Moderate to strong mid to high level southwesterlies
will exist over much of the central and southern Plains, along with
cool temperatures aloft. Meanwhile, an upper ridge will hold over
the Southeast, with moderate winds aloft along the periphery of the
upper ridge extending from the OH Valley into the Northeast.
At the surface, low pressure will develop into IA as the upper wave
moves out of NE and KS. A front/dryline will extend south across
eastern KS, western OK and west central TX during the day.
Meanwhile, an elongated stationary front will extend from IA into
southern WI/MI and into the lower Great Lakes, with more of a warm
front into NY and southern New England. Mid to upper 60s F dewpoints
will remain roughly from TX into IA, with lower 60s F dewpoints
along the length of the stationary front.
...TX/OK/KS/IA/MO/IL...
A focused area of severe storm potential will develop south of the
developing low and along the dryline during the afternoon. Although
the wave will be moving away from OK/TX, the dryline should stall
with strong instability developing and MLCAPE over 3000 J/kg.
Minimal lift will be required near the dryline to initiate afternoon
storms, possibly before 21Z. Cells should develop from northwest TX
across OK and into southeast KS, and gain strength as 50-60 kt
effective shear acts upon them. Both supercells and bowing
structures will be possible, with areas of very large hail and
damaging winds expected. A few tornadoes may occur given the strong
instability and midlevel lapse rates, despite marginal low-level
wind fields.
Farther north, another zone of supercell potential is evident from
northern MO into IA and western IL late in the day ahead of the
shortwave trough. Here, deep-layer shear vector orientation will be
quite favorable for discrete cells, with hail likely. Any early day
storms may affect warm sector quality, but conditionally, a tornado
will be possible.
...From WI/IL eastward into PA...
Areas of heating and warm advection toward the frontal zone will
result in widely scattered afternoon thunderstorms erupting over IL,
IN, southern WI, northern OH and into western PA by 21Z. Favorable
deep-layer shear averaging near 40 kt and at least 1500 J/kg MUCAPE
along this zone will favor storms producing hail and locally
damaging gusts. Storm modes may be mixed.
..Jewell.. 04/14/2026
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0215 PM CDT Tue Apr 14 2026
Valid 161200Z - 171200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE LOWER
OHIO VALLEY REGION INTO PARTS OF NEW YORK...
...SUMMARY...
Isolated strong to severe thunderstorms are possible on Thursday
extending from southeast Missouri across the Ohio Valley and into
parts of New York.
...Synopsis...
A progressive pattern will persist on Thursday, with a leading
shortwave trough moving quickly across OH valley into the Northeast.
This wave will breakdown the ridge along the East Coast, and provide
a focus for scattered strong storms. Low-level warm advection out of
the west/southwest will help destabilize the region with storms most
likely during the afternoon from the Lower Great Lake across much of
upstate NY and northern PA. Instability will be sufficient to
support a few fast-moving cells capable of marginal hail and locally
damaging gusts.
To the southeast, storm coverage is less certain, particularly from
AR/MO into the lower OH Valley. Here, cool temperatures aloft will
linger, aiding instability, though somewhat behind the upper trough
affecting the northeastern states. Showers and storms are most
likely in the morning in association with the main wave, but
conditional severe probabilities will be higher during the afternoon
when instability redevelops. Any storms that form will be capable of
producing hail, from MO into AR, western TN/KY, IL and IN.
..Jewell.. 04/14/2026
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1106 AM CDT Tue Apr 14 2026
Valid 141700Z - 151200Z
...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST COLORADO AND ADJACENT
HIGH PLAINS...
...Morning Update...
No changes have been made to the previous forecast. In the southern
Plains, poor overnight humidity recoveries and strong winds of 15-25
mph (gusts up to 30 mph) this morning will further intensify the
fire weather threat, especially across southeastern CO and adjacent
High Plains. A cold front will push through eastern CO this evening
with winds shifting from west/southwesterly to northerly at 15-20
mph. While RH and cloud cover will increase behind the front, the
initial wind shift could impact ongoing wildfires.
..Elizalde-Garcia/Williams.. 04/14/2026
.PREV DISCUSSION... /ISSUED 0129 AM CDT Tue Apr 14 2026/
...Synopsis...
An upper trough will approach the southern Plains today. At the
surface, a low will deepen in the central Plains. Dry return flow
will continue into the Mid-Atlantic.
...Southeast Colorado into central Plains...
A belt of stronger mid-level winds will overlap the region during
the afternoon. Coupled with the deepening surface low, winds of
20-25 mph appear possible with locally higher speeds in the
terrain-favored areas. RH 10-15% will occur in the High Plains with
greater potential for around 20% farther east. Winds may be equally
strong into Kansas, but the less favorable RH/cloud cover and recent
precipitation may modulate the overall fire weather risk.
...Southwest into southern High Plains...
Moderately strong mid-level winds will extend into the southern
Rockies. Cloud cover associated with the trough will tend to keep RH
higher in some locations, but around 20% east of the higher terrain
appears probable. Winds of 15-20 mph will promote an elevated fire
weather threat during the afternoon.
...Southern Appalachians into the Piedmont/Mid-Atlantic...
Dry return flow of 10-15 mph will occur during the afternoon. RH
will generally be 25-30% as temperatures rise into the mid/upper 80s
F. Very dry fuels in the region will support an elevated fire
weather threat.
...Please see www.spc.noaa.gov/fire for graphic product...
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0200 PM CDT Tue Apr 14 2026
Valid 151200Z - 161200Z
...South-central CO into portions of the Southern High Plains...
A very narrow corridor of elevated fire weather conditions are
expected in the lee of the southern Rockies on Day 2/Wednesday as
gap winds increase in the afternoon. Downslope westerly winds of
15-20 mph will combine with RH of around 15 percent atop receptive
fuels, supporting the expansion of Elevated fire weather highlights.
Farther east, forecast guidance is depicting RH of 10-15 percent and
15-20 mph westerly winds to overlap portions of western OK where
fuels are dry and receptive. Elevated highlights have been expanded
to account for this threat.
...Piedmont/Mid-Atlantic...
Elevated fire weather conditions are expected for much of the region
as southwesterly winds of around 10 mph (localized gusts up to 20
mph) and low RH of 25-35 percent (localized areas less than 25
percent) overlap 90th-99th percentile ERCs. Given the widespread
nature of receptive fuels and multiple days of near record high
temperatures, Elevated highlights have been expanded.
..Elizalde-Garcia/Williams.. 04/14/2026
.PREV DISCUSSION... /ISSUED 0130 AM CDT Tue Apr 14 2026/
...Synopsis...
The upper-level trough will continue eastward into the
Mid-South/Mid-Mississippi Valley on Wednesday. Mid-level winds
across the southern and central High Plains will weaken through the
day. Only a modest lee trough is expected to develop during the
afternoon.
...Southern High Plains...
Mid-level winds will be waning through the day. Even so, a modest
lee trough will promote 15-20 mph winds within the region. RH could
be quite low. Some locations could reach as low as 10% with most
other areas reaching only 15-20%.
...Piedmont...
Temperatures may be slightly warmer than on Tuesday. Upper 80s to
near 90 appears possible. Dry air will remain in place. RH in the
lee of the terrain could fall to under 20% locally, though 20-25% is
more probable for most areas. Continued exceptional fuel dryness
will again support elevated fire weather during the afternoon.
...Southeast Wyoming...
Dry and breezy downslope winds are expected during the afternoon.
While meteorological conditions may support fire weather concerns,
there is potential for precipitation to occur on Tuesday which
lowers confidence in the overall risk.
...Please see www.spc.noaa.gov/fire for graphic product...
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