MD 0404 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF EASTERN KANSAS


Mesoscale Discussion 0404
NWS Storm Prediction Center Norman OK
0353 PM CDT Mon Apr 13 2026

Areas affected...portions of eastern Kansas

Concerning...Severe potential...Watch unlikely 

Valid 132053Z - 132300Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated thunderstorms may develop along a dryline across
portions of eastern Kansas this afternoon/evening. Any storms that
do develop will bring a threat for all hazards, with the main threat
large to very large hail.

DISCUSSION...Latest visible satellite imagery depicts an area of
deepening cumulus along a dryline in the vicinity of Wichita,
Kansas. Ahead of this dryline, surface temperatures in the mid-80s
and dewpoints in the mid-60s F are contributing to 2000-2500+ J/kg
MLCAPE within the warm sector. Steep mid-level lapse rates (evident
on the 18Z LMN special sounding), elongated hodographs (effective
bulk shear of 30-35+ kts per latest mesoanalysis), and ample
buoyancy within the hail growth zone will support the potential for
large to very large hail to 3+ inches in diameter with any storm
that does develop. The tornado threat remains somewhat more
conditional on a storm persisting into the evening hours when a
strengthening nocturnal low-level jet will support increasing
low-level hodograph curvature and an accompanying increase in the
tornado threat for any ongoing supercells.

Watch issuance appears unlikely at this time owing to uncertainty
regarding the occurrence of convective initiation. Trends will be
closely monitored and a watch may be needed should initiation appear
imminent given the conditionally favorable environment.

..Chalmers/Hart.. 04/13/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   37629505 37259551 37059638 37129741 37369761 37859758
            38829716 39309681 39569631 39579562 39299513 38709495
            38139494 37629505 

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 0403 CONCERNING SEVERE THUNDERSTORM WATCH 102... FOR PORTIONS OF NORTHERN INDIANA INTO EXTREME SOUTHWESTERN LOWER MICHIGAN


Mesoscale Discussion 0403
NWS Storm Prediction Center Norman OK
0338 PM CDT Mon Apr 13 2026

Areas affected...portions of northern Indiana into extreme
southwestern Lower Michigan

Concerning...Severe Thunderstorm Watch 102...

Valid 132038Z - 132215Z

The severe weather threat for Severe Thunderstorm Watch 102
continues.

SUMMARY...A severe wind/hail threat should continue with ongoing
storms over the next few hours.

DISCUSSION...A multicellular cluster of thunderstorms is persisting
eastward amid a heated boundary layer (characterized by surface
temperatures over 80 F), and modest vertical wind shear. Multiple
wind damage reports, along with measured gusts around 50 kts have
been received over the past few hours. MRMS MESH has also indicated
the possibility of 1+ inch hail occurring with some of the stronger
storms as well. Given 60+ F surface dewpoints and resultant 1500+
J/kg MLCAPE preceding the storms, a severe wind/hail threat should
continue with these storms for at least a few more hours. Given
adequate surface-based instability preceding supercell structures, a
tornado cannot be completely ruled out.

..Squitieri.. 04/13/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...IWX...GRR...LOT...

LAT...LON   40868754 41528721 42008657 42108576 41988511 41708475
            41278480 41028514 40878580 40798641 40798713 40868754 

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

MD 0402 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTION OF THE TEXAS BIG BEND INTO EDWARD PLATEAU


Mesoscale Discussion 0402
NWS Storm Prediction Center Norman OK
0311 PM CDT Mon Apr 13 2026

Areas affected...portion of the Texas Big Bend into Edward Plateau

Concerning...Severe potential...Watch unlikely 

Valid 132011Z - 132215Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated thunderstorm development is ongoing across
portions of southwest Texas/northern Mexico, with large to very
large hail and severe wind gusts the primary threats.

DISCUSSION...Latest radar and GLM Flash data depict isolated
thunderstorm development across Stockton Plateau in southwest Texas
and the Sierra del Carmen in northern Mexico. Surface temperatures
in the upper-70s and dewpoints in the mid-60s F ahead of an
approaching dryline are supporting 2000-3000+ J/kg MLCAPE. Straight,
elongated hodographs amid 30-40 kts of effective bulk shear and
steep mid-level lapse rates of 7+ C/km (per latest mesoanalysis)
will support supercells capable of large to very large hail and
severe wind gusts. A tornado or two cannot be ruled out should a
supercell persist into the late evening hours as the nocturnal
low-level jet strengths, supporting some increase in low-level
shear/hodograph curvature. Watch issuance appears unlikely at this
time owing to the expected isolated storm coverage. Trends will
continue to be monitored, and a watch may be needed should the
threat magnitude/coverage trend higher.

..Chalmers/Hart.. 04/13/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...EWX...SJT...MAF...

LAT...LON   29510342 29870336 30300300 30960236 31600151 31820091
            31710039 31270014 30950010 30420008 29750021 29000050
            28940075 29090084 29380121 29670165 29730226 29610260
            29410274 29350312 29510342 

MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN

MD 0401 CONCERNING SEVERE POTENTIAL...TORNADO WATCH LIKELY FOR PORTIONS OF EXTREME SOUTHEASTERN SOUTH DAKOTA INTO EXTREME NORTHERN IOWA AND SOUTHERN MINNESOTA


Mesoscale Discussion 0401
NWS Storm Prediction Center Norman OK
0259 PM CDT Mon Apr 13 2026

Areas affected...portions of extreme southeastern South Dakota into
extreme northern Iowa and southern Minnesota

Concerning...Severe potential...Tornado Watch likely 

Valid 131959Z - 132130Z

Probability of Watch Issuance...95 percent

SUMMARY...The severe threat will increase along and to the north of
a warm front over the next few hours. Severe wind/hail and at least
a few tornadoes are possible. A couple of strong tornadoes may
occur. A Tornado Watch is being issued.

DISCUSSION...As widespread stratiform clouds erode in proximity to a
warm front, MLCINH will continue to decrease, which is already
supporting the development of a CU field between the primary warm
front (where richer moisture is in place along the MN/IA border),
and a differential heating boundary to the north in southern MN.
Over 2000 J/kg MLCAPE and 50 kts of effective bulk shear is in
place, which will support supercell structures capable of severe
wind and hail. Severe hail is possible with any storms along the
warm front or near the differential heating boundary, with 2+ inch
hail possible. Tornadoes will also be possible with supercells
anchoring to the warm front. Should a more dominant, discrete
supercell sustain along the warm front, strong tornadoes will become
possible. A Tornado Watch will be issued soon.

..Squitieri/Hart.. 04/13/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...ARX...MPX...DMX...FSD...

LAT...LON   43929685 44459550 44789417 44819352 44659307 44239276
            43749272 43409307 43269386 43309488 43409583 43489621
            43619666 43929685 

MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN

MD 0400 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF NORTHEASTERN NEBRASKA INTO FAR SOUTHEASTERN SOUTH DAKOTA...EXTREME SOUTHWESTERN MINNESOTA...AND EXTREME NORTHWESTERN IOWA


Mesoscale Discussion 0400
NWS Storm Prediction Center Norman OK
0242 PM CDT Mon Apr 13 2026

Areas affected...portions of northeastern Nebraska into far
southeastern South Dakota...extreme southwestern Minnesota...and
extreme northwestern Iowa

Concerning...Severe potential...Watch possible 

Valid 131942Z - 132115Z

Probability of Watch Issuance...60 percent

SUMMARY...The severe threat should generally increase north of a
surface low over portions of northern NE into far southeastern SD
over the next few hours. Convective trends are being monitored for
the need of a WW issuance.

DISCUSSION...Low 60s F surface dewpoints are pivoting around and to
the north of a surface low over central NE, which is boosting MLCAPE
over 2000 J/kg given 8-9 C/km mid-level lapse rates in place (per
19Z mesoanalysis and an 18Z OAX observed sounding). Agitated CU is
developing along the NE/SD border, where MLCINH appears to be
rapidly eroding. The OAX observed sounding shows an elongated
hodograph with modest low-level curvature, and the 19Z mesoanalysis
depicts over 50 kts of effective bulk shear, suggesting supercell
storm modes. Occasional runs of some high-resolution guidance
members have depicted the initiation of stout, long-lived supercell
structures originating from this mesoscale scenario. 

AS MLCINH continues to erode, supercells should develop over the
next few hours, accompanied by a severe hail threat. Significant
severe hail is possible, with 2-3 inch stones possible, and an
instance of 4+ inch diameter hail cannot be completely ruled out.
Furthermore, any storms that can anchor to the warm front ahead of
the surface low may be accompanied by a tornado threat. Convective
trends will continue to be monitored for the need of a WW issuance.

..Squitieri/Hart.. 04/13/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FSD...OAX...LBF...

LAT...LON   42379819 41969910 41899934 41969948 42159945 42499918
            42989881 43549813 43649762 43629682 43549640 43349614
            43089605 42819626 42689668 42649736 42499783 42379819 

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN

MD 0399 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF NORTHWEST TEXAS INTO CENTRAL OKLAHOMA


Mesoscale Discussion 0399
NWS Storm Prediction Center Norman OK
0238 PM CDT Mon Apr 13 2026

Areas affected...portions of northwest Texas into central Oklahoma

Concerning...Severe potential...Watch possible 

Valid 131938Z - 132145Z

Probability of Watch Issuance...60 percent

SUMMARY...Isolated to widely scattered thunderstorm development is
possible along a dryline this afternoon. Any sustained storms that
are able to develop will bring the potential for all severe hazards,
with the primary threat large to very large hail.

DISCUSSION...Latest surface observations depict a dryline extending
south-southwestward across western Oklahoma and northwest Texas. An
area of deepening cumulus is noted in recent visible satellite
imagery across portions of the Texas Rolling Plains where convective
temperatures are beginning to be reached amid strong diurnal heating
and deep boundary layer mixing behind the dryline. Within the warm
sector, mid-80s temperatures amid mid/upper 60s F dewpoints and
steep mid-level lapse rates (per 18Z LMN special sounding) are
contributing to 2000-3000 J/kg MLCAPE. 

While upper-level forcing is forecast to remain modest at best,
30-40 kts of effective bulk shear amid a belt of enhanced mid-level
flow (40+ kts at 4-5 km AGL per regional VWPs) will support
supercells capable of all hazards. The primary threat with any
storms that do develop is expected to be large to very large hail to
2-3+ inches in diameter, which is supported by recent mesoanalysis
that indicates ample buoyancy within the hail growth zone and SHIP
values of 2+. The tornado threat remains somewhat more conditional
on a storm persisting into the evening hours when a strengthening of
the nocturnal low-level jet will yield increasing low-level SRH and
clockwise hodograph curvature.

While the timing of potential convective initiation and subsequent
storm coverage remain somewhat uncertain, a watch will likely be
needed should initiation appear imminent given the conditionally
favorable warm sector environment.

..Chalmers/Hart.. 04/13/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TSA...FWD...OUN...SJT...

LAT...LON   31590023 31890044 32320043 32949998 33669938 34289902
            35339860 35939814 36329749 36409705 36339669 36019643
            35239632 34189672 33509717 32699779 32109849 31679918
            31549972 31590023 

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

WW 0102 Status Updates


STATUS REPORT ON WW 102

SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNE DNV
TO 30 SW VPZ TO 20 WSW BEH.

FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0403

..SQUITIERI..04/13/26

ATTN...WFO...LOT...IWX...


STATUS REPORT FOR WS 102 

SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS 

INC033-039-049-073-085-087-091-099-113-127-131-141-149-151-181-
183-132140-

IN 
.    INDIANA COUNTIES INCLUDED ARE

DE KALB              ELKHART             FULTON              
JASPER               KOSCIUSKO           LAGRANGE            
LA PORTE             MARSHALL            NOBLE               
PORTER               PULASKI             ST. JOSEPH          
STARKE               STEUBEN             WHITE               
WHITLEY              


MIC021-023-027-149-132140-

MI 
.    MICHIGAN COUNTIES INCLUDED ARE

BERRIEN              BRANCH              CASS                
ST. JOSEPH

WW 102 SEVERE TSTM IL IN MI LM 131910Z - 140200Z


URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 102
NWS Storm Prediction Center Norman OK
210 PM CDT Mon Apr 13 2026

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Northeast Illinois
  Northern Indiana
  Southwest Lower Michigan
  Lake Michigan

* Effective this Monday afternoon and evening from 210 PM until
  900 PM CDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...A cluster of thunderstorms over northeast Illinois will
track eastward through the afternoon.  The strongest cells will pose
a risk of large hail and damaging wind gusts.

The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 70 miles west southwest
of Valparaiso IN to 45 miles north northeast of Fort Wayne IN. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU2).

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
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
26025.

...Hart

WW 0103 Status Updates


STATUS REPORT ON WW 102

SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNE DNV
TO 30 SW VPZ TO 20 WSW BEH.

FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0403

..SQUITIERI..04/13/26

ATTN...WFO...LOT...IWX...


STATUS REPORT FOR WS 102 

SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS 

INC033-039-049-073-085-087-091-099-113-127-131-141-149-151-181-
183-132140-

IN 
.    INDIANA COUNTIES INCLUDED ARE

DE KALB              ELKHART             FULTON              
JASPER               KOSCIUSKO           LAGRANGE            
LA PORTE             MARSHALL            NOBLE               
PORTER               PULASKI             ST. JOSEPH          
STARKE               STEUBEN             WHITE               
WHITLEY              


MIC021-023-027-149-132140-

MI 
.    MICHIGAN COUNTIES INCLUDED ARE

BERRIEN              BRANCH              CASS                
ST. JOSEPH

WW 103 TORNADO IA MN WI LM 132010Z - 140300Z


URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 103
NWS Storm Prediction Center Norman OK
310 PM CDT Mon Apr 13 2026

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northern Iowa
  Southern Minnesota
  Central Wisconsin
  Lake Michigan

* Effective this Monday afternoon and evening from 310 PM until
  1000 PM CDT.

* Primary threats include...
  A few tornadoes likely with a couple intense tornadoes possible
  Widespread large hail and isolated very large hail events to 3
    inches in diameter likely
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Thunderstorms are expected to rapidly develop this
afternoon along a warm front across the watch area.  Supercells
capable of very large hail and tornadoes are possible.  A strong
tornado is possible.

The tornado watch area is approximately along and 50 statute miles
north and south of a line from 30 miles west northwest of Fairmont
MN to 20 miles east northeast of Oshkosh WI. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).

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 102...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 3 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 26030.

...Hart

SPC Day 2 Fire Weather Outlook

Day 2 Fire Weather Outlook CORR 1
NWS Storm Prediction Center Norman OK
0259 PM CDT Mon Apr 13 2026

Valid 141200Z - 151200Z

CORRECTED HEADLINE

...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST COLORADO AND ADJACENT
HIGH PLAINS...

...Southeast Colorado...
Critical highlights have been expanded slightly north to account for
a broader corridor of stronger west-southwesterly winds and very low
RH of near 10 percent ahead of an incoming cold front. With spotty
high clouds present in the afternoon, surface wind gusts of 30-40
mph may emerge from efficient boundary layer mixing of 700-850 mb
layer winds of 30-40 kt, enhancing fire weather concerns.

...Mid-Atlantic towards the Piedmont...
Widespread southerly winds greater than 10 mph (gusts of 15-20 mph)
and RH of 25-40 percent are expected to overlap a region of broad
95th-99th percentile ERC values and recently receptive fuels.
Elevated fire weather highlights have been expanded farther south
into the Piedmont and eastward towards the Virginia/North Carolina
coastlines to account for these pervasive conditions.

See the previous discussion for more information.

..Elizalde-Garcia/Williams.. 04/13/2026

.PREV DISCUSSION... /ISSUED 1248 AM CDT Mon Apr 13 2026/

...Synopsis...
The progression of the upper trough in the Southwest/southern High
Plains is expected to slow on Tuesday. The trough may not eject into
the Plains until early Wednesday morning. A surface low will deepen
in the central High Plains.

...Southeast Colorado and vicinity...
A similar setup to Monday is expected, though the location of the
trough will bring better alignment of stronger mid-level winds to
the region. The deepening surface low will further increase surface
wind speeds to 20-25 mph. RH of around 15% appears likely. Farther
east into Kansas, the surface winds will be similarly strong along
with a very dry airmass (RH perhaps nearing 10% in some locations).
Recent rainfall should mitigate some fire weather risk with eastward
extent. Critical fire weather is expected.

...Parts of the Southwest into the southern High Plains...
The base of the trough over this region along with a moderately
strong surface pressure gradient will promote 15-20 mph winds. RH
will be somewhat uncertain given the expected mid-level clouds.
However, around 20% is possible for broad portions of the region.
Elevated fire weather is forecast during the afternoon.

...Mid-Atlantic...
Dry return flow will continue in the Mid-Atlantic. 10-15 mph winds
around the surface high are probable during the afternoon. 25-30% RH
will also occur. Despite the marginal meteorological conditions,
very dry fuels will support an elevated fire weather threat.

...Please see www.spc.noaa.gov/fire for graphic product...

SPC 2000Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0256 PM CDT Mon Apr 13 2026

Valid 132000Z - 141200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
SOUTHERN MINNESOTA...NORTHERN IOWA...AND CENTRAL WISCONSIN...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
TEXAS...OKLAHOMA AND THE CENTRAL GREAT LAKES....

...SUMMARY...
Severe thunderstorms remain likely across the Upper Mississippi
Valley and Great Lakes region with potential for large to very large
hail, damaging wind, and tornadoes, mainly late this afternoon into
tonight. A more isolated risk for severe storms is possible across
portions of the southern Plains late this afternoon and evening.

...20z Update Upper Midwest...
Afternoon visible imagery showed diurnal heating ongoing south of
the stalled front from the eastern SD across southern MN into
central WI. Moderate destabilization should support scattered to
numerous thunderstorms this afternoon and evening. Initially
supercells are likely, given strongly veering wind profiles and
moderate deep-layer flow. All hazards are possible with these
storms. With time, upscale growth into one or more lines or clusters
appears likely as storms spread eastward into the Great Lakes.

Convective development appears likely along the triple point near
the surface low from northeast/eastern NE into southeastern SD.
Supercell wind profiles and moderate buoyancy would support a risk
for large hail and some damaging wind gusts. A tornado or two may
occur as any supercells that develop move eastward into deeper
low-level moisture across northwestern IA and southern MN.

...Southern and Central Plains...
Towering cumulus along a dryline over parts of KS/OK/TX may support
isolated storm development late this afternoon. A conditionally
favorable environment (3000+ j/kg of MLCAPE and 35-40 kt effective
shear) for supercells will support a risk for all hazards. See MCD
#399 for short term information. The primary change for this outlook
was to extend severe probabilities northeastward into eastern KS.
Guidance and observational trends have shown an increased likelihood
of a storm or two this afternoon.

..Lyons.. 04/13/2026

.PREV DISCUSSION... /ISSUED 1136 AM CDT Mon Apr 13 2026/

...Upper Mississippi Valley/Great Lakes including MN/WI/IA...
Multiple lead mid-level disturbances over the northern High Plains
will progress northeastward today toward the Upper Midwest, with
strengthening winds aloft across this region particularly late today
and tonight. A surface low will tend to deepen/develop
east-northeastward from northeast Nebraska into far southern
Minnesota and Wisconsin by tonight in vicinity of a
slow-moving/stalled frontal boundary. Low/middle 60s F surface
dewpoints will advect north-northeastward and become increasingly
prevalent along/south of the aforementioned stationary/warm front
this afternoon. MLCAPE values are forecast to reach 2000-2500 J/kg
by around 21z/4pm CDT.

Thunderstorm development will become increasingly probable through
mid/late afternoon (21-00z) as isentropic ascent strengthens ahead
of the approaching upper disturbance. This should especially be the
case near the primary boundary. However, semi-discrete warm sector
supercellular development, across areas such as southern Wisconsin,
cannot be ruled out. Lingering inhibition coupled with 45-50 kt
effective bulk shear should promote initially discrete supercells.
Hodograph elongation appears favorable for a large hail threat,
possibly as large as 2-3 inches in diameter with the more robust
cells. Additionally, enhanced low-level SRH along the frontal zone
is expected to result in a corridor of relatively higher tornado
potential for storms that can remain rooted immediately along the
boundary.

While the overall environment appears very favorable for intense
convection/supercells, east-northeasterly storm motions along or
just north of the warm front will likely promote clustering/upscale
growth through the evening, with an increasing damaging wind
potential and a continued tornado risk via line-embedded
circulations.

...Northern Illinois/northern Indiana and southern Lake Michigan...
See Mesoscale Discussion 395 for short-term details. There is the
potential that a somewhat separate corridor of severe-weather
potential today, potentially via a subtle mid-level wave and morning
convection across northeast Missouri/northwest Illinois vicinity
and/or additional development later today. The initially elevated
storms are on the edge of the east/northeastward-advecting elevated
mixed layer. Steep mid-level lapse rates and 35+ kt effective shear
could support initially isolated hail potential, but a more
organized surface-based severe risk could materialize later this
afternoon, although the specific details remain uncertain.

...Southern Plains including Oklahoma/Texas...
Confidence/potential for isolated to widely scattered locally
intense storms later this afternoon has incrementally increased,
although specifics regarding the extent of convective initiation are
still uncertain.

A moist and potentially unstable air mass will persist regionally to
the east of a dryline located around peak heating from east-central
Kansas south-southwestward into west-central Oklahoma and western
north Texas to the Texas Big Bend vicinity. Immediately east of the
dryline, warm-sector dewpoints are expected to generally be in the
middle 60s F, supporting MLCAPE values to 2500-3000 J/kg. A subtle
disturbance over northern Mexico and the southern Rockies could
approach the dryline/warm sector later today.

Regardless, ample post-dryline mixing and near-dryline
confluence/weak convergence should be sufficient for isolated deep
convective initiation after 21z/4pm CDT. Forecast mass fields and
some short-term guidance would imply that this is most probable
across central/southwest Oklahoma into the north Texas Big Country,
and perhaps somewhat separately across the Texas Big Bend and Rio
Grande vicinity.

If/where storms develop and mature, deep-layer shear on the order of
40+ kt will support supercells, potentially capable of all hazards
including very large hail.

...Northern High Plains...
Generally isolated severe storms including a few low-topped
supercells capable of hail/wind are possible late this afternoon
into evening along/north of the surface front. This is where modest
low-level moisture and vertical shear will be maximized, in the
presence of steep low/mid-level lapse rates.

SPC 1930Z Day 3 Outlook

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0221 PM CDT Mon Apr 13 2026

Valid 151200Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTION OF THE
SOUTHERN PLAINS INTO SOUTHERN WISCONSIN...

...SUMMARY...
Severe thunderstorms posing a risk for large hail and strong wind
gusts will be possible across portions of the southern Plains toward
the Great Lakes on Wednesday afternoon and evening.

...Synopsis...
The upper-level trough will move eastward from the Plains into the
Upper Midwest on Wednesday, with continued enhanced west to
southwesterly flow across the southern Plains into the Great Lakes
Region. The surface dryline will remain in a similar location from
Tuesday, extending across western Oklahoma into southwestern and
western Texas. A surface low will shift eastward across IA into WI,
with a cold front shifting south and east through the period.
Scattered thunderstorm development is expected from the Southern
Plains into the Upper Midwest along the aforementioned boundaries
Wednesday afternoon and evening.

...Southern Plains to Great Lakes...
Widely scattered showers and thunderstorms will be ongoing at the
start of the period at 12z Wednesday across much of the Slight Risk
region. A secondary round of thunderstorm development is likely to
occur near and ahead of the dryline extending from west Texas into
western Oklahoma Wednesday afternoon. It remains somewhat uncertain
how morning convection will evolve and what the resulting effect on
the thermodynamic environment will be. Most guidance suggests that
in the area ahead of the dryline across central OK to the Red River
in northern Texas will develop at least moderate instability
(1000-2000 J/kg of MLCAPE). Deep layer shear profiles will remain
strong favoring supercells as the primary mode. The main threat will
be for large to very large hail and damaging wind, given linearly
elongated hodographs and weaker low-level shear.

Thunderstorms are also expected to re-develop further north across
the central Plains into the Great Lakes region along the
dryline/cold front intersection. A messy mode with mix of supercells
and multi-cell clusters is likely given the eventual southward
moving cold front. Similarly, the main risks will be for damaging
wind and large hail across these regions. 

...Northeast...
Shower and thunderstorm activity is expected to develop along and
south of a diffuse frontal boundary across the Great Lakes into
southern NY/northern PA. Modestly unstable profiles, steepening
lapse rates, and strong deep layer shear will allow for some
isolated severe storm risk. Primary risk would be for damaging wind
and small hail, though, a tornado could be possible near the
boundary.

..Thornton.. 04/13/2026

SPC 1730Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1229 PM CDT Mon Apr 13 2026

Valid 141200Z - 151200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF IOWA INTO NORTHERN ILLINOIS AND SOUTHERN WISCONSIN...

...SUMMARY...
Severe thunderstorms are expected on Tuesday and Tuesday night from
the Southern Plains to the Great Lakes. Large to very large hail, a
few tornadoes (some strong), and damaging wind gusts will be
possible, particularly across parts of eastern Iowa, northern
Illinois, and southern Wisconsin. Additional strong storms, mainly
producing strong wind gusts, will be possible across parts of the
Northeast.

...Synopsis...
The western US trough will eject across the Four Corners region into
the Intermountain West, with strong southwesterly flow overspreading
the Rockies into the central/southern Plains and Upper Midwest. A
shortwave trough will pivot through this flow across the Upper
Midwest through the period. A surface low will be centered over the
Mid-MO Valley for much of the period, with a warm front extending
east/northeast from north-central IA into southern WI and central
Lower MI. Meanwhile, a dryline will extend southwest across eastern
KS into western TX. These features will be the focus of scattered
thunderstorm development through the afternoon and evening.

...Mid-Missouri Valley and Great Lakes Region...
Strong daytime heating is expected along and south of the warm from
north-central IA into southern WI and lower MI Tuesday afternoon.
This in combination with dew points in the low to mid 60s will yield
moderate to strong instability (with MLCAPE around 1500-2500 J/kg).
Scattered thunderstorms are likely to develop around 20z. Given deep
layer shear around 40 kts, storm mode will be supercellular.
Initially, low-level shear will be marginal, with generally straight
and elongated hodographs. In addition, northeasterly storm motions
will favor crossing the warm front to the cool side of the boundary.
This will make the primary threat large to very large hail (some
2-3+ inches in diameter). With time, and as the low-level jet
increases during the evening, convection may consolidate/grow
upscale into one or more bowing segments and progress eastward into
Lower MI/IN/OH, posing a continued risk for hail and an increasing
risk for damaging wind gusts.

As the strengthening 850-700 mb low-level jet axis will nudge into
central IA/northern MO/northern IL, it will usher in a plume of
steep low to mid-level lapse rates and enlarge low-level hodographs,
increasing tornado potential. While there remains some uncertainty,
there is signal within hi-res guidance from the HREF for sustained
UH tracks south of the warm front. CAM guidance varies on how the
scenario will play out. As mentioned above, a few CAM solutions
favor clustering/linear development by the evening. Should a more
discrete supercell or two be able to root along or south of the
boundary, a few tornadoes will be possible (some strong EF2+).
Nonetheless, even with a more linear mode increasing low-level shear
will favor and increasing chance for line embedded tornadoes.

...Southern Plains into eastern Kansas/western Missouri...
Thunderstorm development is likely along the dryline across the
southern Plains Tuesday afternoon. Strong capping with remain
through most of the morning, but strong heating and convergence
along the dryline favor at least isolated thunderstorm development
by around 19-20z. The environment ahead of the dryline will be
characterized by moderate to strong instability, steep lapse rates,
and favorable deep layer shear profiles to support supercells. Large
to very large hail (1-2+ inches in diameter), damaging winds, and
perhaps a tornado.

...Northeast...
Rounds of thunderstorms are expected during the afternoon and
evening within a warm advection regime. MLCAPE should increase to
around 1000 J/kg within a moistening low-level air mass. Strong
deep-layer westerly flow and steepening low-level lapse rates will
support isolated strong wind gusts across the region.

..Thornton.. 04/13/2026

SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1136 AM CDT Mon Apr 13 2026

Valid 131630Z - 141200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN
MINNESOTA...FAR NORTHERN IOWA...AND PARTS OF WISCONSIN...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN PLAINS...

...SUMMARY...
Severe thunderstorms are likely across the Upper Mississippi Valley
and Great Lakes region with potential for large to very large hail,
damaging wind, and tornadoes, mainly late this afternoon into
tonight. A more isolated risk for severe storms is possible across
portions of the southern Plains late this afternoon and evening.

...Upper Mississippi Valley/Great Lakes including MN/WI/IA...
Multiple lead mid-level disturbances over the northern High Plains
will progress northeastward today toward the Upper Midwest, with
strengthening winds aloft across this region particularly late today
and tonight. A surface low will tend to deepen/develop
east-northeastward from northeast Nebraska into far southern
Minnesota and Wisconsin by tonight in vicinity of a
slow-moving/stalled frontal boundary. Low/middle 60s F surface
dewpoints will advect north-northeastward and become increasingly
prevalent along/south of the aforementioned stationary/warm front
this afternoon. MLCAPE values are forecast to reach 2000-2500 J/kg
by around 21z/4pm CDT.

Thunderstorm development will become increasingly probable through
mid/late afternoon (21-00z) as isentropic ascent strengthens ahead
of the approaching upper disturbance. This should especially be the
case near the primary boundary. However, semi-discrete warm sector
supercellular development, across areas such as southern Wisconsin,
cannot be ruled out. Lingering inhibition coupled with 45-50 kt
effective bulk shear should promote initially discrete supercells.
Hodograph elongation appears favorable for a large hail threat,
possibly as large as 2-3 inches in diameter with the more robust
cells. Additionally, enhanced low-level SRH along the frontal zone
is expected to result in a corridor of relatively higher tornado
potential for storms that can remain rooted immediately along the
boundary.

While the overall environment appears very favorable for intense
convection/supercells, east-northeasterly storm motions along or
just north of the warm front will likely promote clustering/upscale
growth through the evening, with an increasing damaging wind
potential and a continued tornado risk via line-embedded
circulations.

...Northern Illinois/northern Indiana and southern Lake Michigan...
See Mesoscale Discussion 395 for short-term details. There is the
potential that a somewhat separate corridor of severe-weather
potential today, potentially via a subtle mid-level wave and morning
convection across northeast Missouri/northwest Illinois vicinity
and/or additional development later today. The initially elevated
storms are on the edge of the east/northeastward-advecting elevated
mixed layer. Steep mid-level lapse rates and 35+ kt effective shear
could support initially isolated hail potential, but a more
organized surface-based severe risk could materialize later this
afternoon, although the specific details remain uncertain.

...Southern Plains including Oklahoma/Texas...
Confidence/potential for isolated to widely scattered locally
intense storms later this afternoon has incrementally increased,
although specifics regarding the extent of convective initiation are
still uncertain.

A moist and potentially unstable air mass will persist regionally to
the east of a dryline located around peak heating from east-central
Kansas south-southwestward into west-central Oklahoma and western
north Texas to the Texas Big Bend vicinity. Immediately east of the
dryline, warm-sector dewpoints are expected to generally be in the
middle 60s F, supporting MLCAPE values to 2500-3000 J/kg. A subtle
disturbance over northern Mexico and the southern Rockies could
approach the dryline/warm sector later today.

Regardless, ample post-dryline mixing and near-dryline
confluence/weak convergence should be sufficient for isolated deep
convective initiation after 21z/4pm CDT. Forecast mass fields and
some short-term guidance would imply that this is most probable
across central/southwest Oklahoma into the north Texas Big Country,
and perhaps somewhat separately across the Texas Big Bend and Rio
Grande vicinity.

If/where storms develop and mature, deep-layer shear on the order of
40+ kt will support supercells, potentially capable of all hazards
including very large hail.

...Northern High Plains...
Generally isolated severe storms including a few low-topped
supercells capable of hail/wind are possible late this afternoon
into evening along/north of the surface front. This is where modest
low-level moisture and vertical shear will be maximized, in the
presence of steep low/mid-level lapse rates.

..Guyer/Chalmers.. 04/13/2026

SPC Day 1 Fire Weather Outlook

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1058 AM CDT Mon Apr 13 2026

Valid 131700Z - 141200Z

...CRITICAL FIRE WEATHER AREA FOR EASTERN WYOMING...SOUTHWESTERN
SOUTH DAKOTA...NORTHWESTERN NEBRASKA...
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN PLAINS...

...Southern Plains...
Critical fire weather highlights have been expanded farther east to
account for expected stronger afternoon winds and very low RH
overlapping a region of receptive fuels and exceptional fuel
loading. Current observations portray an eastward progressing
dryline into western OK, with RH already dropping to below 20
percent and sustained southwesterly winds increasing to 20 mph
behind the dryline. As cloud cover decreases this morning, deeper
mixing will encourage surface wind gusts of up 30-35 mph and
decreasing RH to less than 15 percent, heightening fire spread
concerns. 

The rest of the forecast remains on track, see the previous
discussion for more information.

..Elizalde-Garcia/Williams.. 04/13/2026

.PREV DISCUSSION... /ISSUED 1246 AM CDT Mon Apr 13 2026/

...Synopsis...
Continued southwesterly flow aloft is expected today across much of
the central/southern Plains. A shortwave trough is expected to
approach the southern Plains very late in the period. A weaker
shortwave trough in the central Northern Plains will also be
present. At the surface, a broad area of low pressure will exist
east of the terrain.

...Eastern Wyoming into western South Dakota and Nebraska...
The northern stream mid-level jet will be favorably timed with
afternoon heating/minimum RH. This feature, coupled with the surface
trough to the east, will drive 20-25 mph winds in eastern portions
of Wyoming and adjacent western South Dakota and Nebraska. RH will
likely fall to 10-15%. Critical fire weather is expected for a few
hours during the afternoon. Farther south into the Front Range,
winds will be weaker leading to elevated fire weather.

...Southeast Colorado and vicinity...
The position of a modest surface low in southeast Colorado will
promote surface winds of around 20 mph despite the stronger
mid-level winds lagging farther southwest. Terrain enhancement could
also lead to local corridors of stronger winds. RH of around 15% is
expected during the afternoon. These conditions will support
critical fire weather.

...Piedmont...southern Appalachians...
Dry return flow around a surface high pressure system will promote
10-15 mph winds within parts of the southern Appalachians and the
Piedmont region. RH of near 20% is possible in parts of the
Mid-Atlantic though higher values of 25-35% are expected with
southward extent. Given how dry fuels are, elevated fire weather
conditions are expected.

...Please see www.spc.noaa.gov/fire for graphic product...