2025 Severe Weather

[WaveBreaking]

Huge 15% risk for Day 7 (March 30th-31st)

[cycloneye]

Huge 15% risk for Day 7 (March 30th-31st)
https://i.imgur.com/GuNb9GF.gif
https://i.imgur.com/SKZ7YHm.jpeg

Day 7/Sunday, eastward advance of the synoptic-scale features will
continue, along with some continued strengthening. With continued
moistening of the pre-frontal warm sector supporting afternoon
destabilization, along with increasing deep-layer flow, a broad area
of severe risk seems likely to evolve -- centered over the Mid and
Lower Mississippi/Lower Ohio/Tennessee Valleys. Again -- all severe
weather hazards would be possible.

[cycloneye]

Discussion for day 6.

The primary severe risk appears likely to evolve Sunday/Day 6, from
Missouri/Arkansas/northern Louisiana, spreading eastward through the
day, and eventually approaching the west slopes of the Appalachians.
As the western U.S. upper trough emerges into the Plains,
supporting deepening of surface low pressure, a moist warm sector
will destabilize through the day, likely yielding storm development
initially west of the Mississippi Valley, and then spreading
eastward through the evening. The favorable thermodynamic
environment will combine with strong/veering flow through the middle
troposphere, suggesting of severe storms including supercells, and
attendant, all-hazards severe potential.

[cycloneye]

Day 5.

Day 5/Sunday, more substantial cyclogenesis is expected, though
differences exist between the models in terms of timing/location of
the developing low -- and associated cold front. Nonetheless,
substantial warm-sector destabilization is forecast to occur from
Missouri/Arkansas/eastern Texas eastward across the Mississippi
Valley during the day, and extending eastward across the
Midwest/Ohio and Tennessee Valleys. This will support scattered
thunderstorm development, within an increasingly sheared
environment. By early afternoon, severe/supercell storms are
expected, accompanied by the risk for very large hail, damaging
winds, and a few tornadoes. Storms should spread southeast of the
Ohio and Mississippi Valleys overnight, accompanied by ongoing
severe risk.

[cycloneye]

Eric Webb X thread about a possible active severe season.

 https://x.com/webberweather/status/1904664814674468895

[cycloneye]

Day 4 discussion.

a fairly widespread area of severe potential remains
evident Day 4/Sunday, ahead of a cold front moving eastward across
the Mississippi and Ohio and eventually the Tennessee Valleys.
Northward advection of 60s dewpoints is expected ahead of this
front, which will combine with daytime heating to boost mixed-layer
CAPE into the 1000 to 1500 J/kg range, and potentially above 2000
J/kg farther southwestward along the front from East Texas into the
lower Mississippi Valley.

As a belt of strong southwesterly flow aloft overspreads the
moistening/destabilizing pre-frontal boundary layer, development of
strong/severe storms is expected near and ahead of the boundary
during the afternoon -- potentially extending as far southwestward
as East Texas. Along with potential for large hail and damaging
winds, likelihood for supercell storms suggests potential for a few
tornadoes as well.

[USTropics]

This is a great addition to Storm2k, thanks for putting this together cycloneye.

Just want to highlight there is now a Day 5 Severe Weather Risk (this would be for Monday of next week) in addition to the Day 4 (Sunday):

Day 5/Monday, models begin to differ more substantially with respect
to surface frontal location -- particularly with northern extent.
The GFS depicts the front as extending from New England
southwestward to the Texas Coast Monday morning, while the ECMWF
places it from Lower Michigan to coastal Texas. By late afternoon,
the GFS shows the front reaching the New England coastal area and
Mid-Atlantic region, focusing the primary severe threat from the
Mid-Atlantic area southwestward. Meanwhile, some risk could extend
as far north as the Lower Great Lakes region/central Appalachians
per the ECMWF's deterministic forecast. At this time, will keep the
Day 5 risk area focused from the Mid-Atlantic region to the lower
Mississippi Valley, though adjustments/refinements to the area over
the next several days will likely be required.

As the discussion states, details are still murky given the split model solutions. The ECMWF has been hedging towards a more active frontal line the past few runs (latest 12z animation for Monday):

[cycloneye]

Day 3 outlook:

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0240 AM CDT Fri Mar 28 2025

Valid 301200Z - 311200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM
ILLINOIS/INDIANA/WESTERN OHIO SOUTHWESTWARD TO THE ARKANSAS/NORTHERN
MISSISSIPPI VICINITY...

...SUMMARY...
A widespread/substantial severe-weather episode is forecast across
an area centered on the Ohio/Mid and Lower Mississippi/Lower
Missouri/Tennessee River Valleys. Very large hail, damaging winds,
and strong tornadoes are expected.

...Synopsis...
An evolving/slowly amplifying mid-level trough is forecast to shift
slowly across the central U.S. Sunday. As this occurs, a deepening
surface low will shift northeastward across the Upper Great Lakes
region. A trailing cold front will sweep southeastward across the
central U.S. as the low deepens/advances, and should extend from the
Lower Great Lakes to the central Gulf Coast states by Monday
morning.

...Lower Great Lakes to the Lower Mississippi and Tennessee
Valleys...
A broad/moist but initially capped airmass is forecast to expand
across much of the eastern half of the U.S. Sunday, ahead of the
advancing cold front. Daytime heating, and continued northward flux
of low-level moisture will result in a moderate destabilization.

Scattered storms may be ongoing across portions of Missouri
northeastward to the Wisconsin area at the start of the period, and
possibly in a more isolated manner southwestward into Texas. Local
severe risk may accompany this early-day convection. The
aforementioned destabilization that is expected should support
renewed storm development near the advancing cold front -- initially
from Illinois southwestward to East Texas, and then spreading
eastward/expanding in coverage with time.

Along with the favorable thermodynamic environment within which the
storms will be evolving, highly favorable shear will also exist,
with low-level southerly/southwesterly flow veering and increasing
substantially with height yielding curved -- and then elongated --
hodographs. Supercells are expected within this environment, and
very large hail is expected given the cold air/steep lapse rates
through the mid troposphere. Along with the hail risk, damaging
wind gusts are expected -- particularly where upscale growth into
bands occurs. Additionally, this setup appears very favorable for
tornadoes, a few of which may be strong/potentially long-lived.

Risk will spread eastward with time into the evening/overnight.
Some diminishing of the risk should occur late into the upper Ohio
Valley, but vigorous storms and all-hazards risk will likely
continue through the end of the period across the Tennessee
Valley/Gulf Coast states.

[cycloneye]

[TomballEd]

Day 3 outlook:


https://i.imgur.com/oMo6UZF.gif

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0240 AM CDT Fri Mar 28 2025

Valid 301200Z - 311200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM
ILLINOIS/INDIANA/WESTERN OHIO SOUTHWESTWARD TO THE ARKANSAS/NORTHERN
MISSISSIPPI VICINITY...

...SUMMARY...
A widespread/substantial severe-weather episode is forecast across
an area centered on the Ohio/Mid and Lower Mississippi/Lower
Missouri/Tennessee River Valleys. Very large hail, damaging winds,
and strong tornadoes are expected.

...Synopsis...
An evolving/slowly amplifying mid-level trough is forecast to shift
slowly across the central U.S. Sunday. As this occurs, a deepening
surface low will shift northeastward across the Upper Great Lakes
region. A trailing cold front will sweep southeastward across the
central U.S. as the low deepens/advances, and should extend from the
Lower Great Lakes to the central Gulf Coast states by Monday
morning.

...Lower Great Lakes to the Lower Mississippi and Tennessee
Valleys...
A broad/moist but initially capped airmass is forecast to expand
across much of the eastern half of the U.S. Sunday, ahead of the
advancing cold front. Daytime heating, and continued northward flux
of low-level moisture will result in a moderate destabilization.

Scattered storms may be ongoing across portions of Missouri
northeastward to the Wisconsin area at the start of the period, and
possibly in a more isolated manner southwestward into Texas. Local
severe risk may accompany this early-day convection. The
aforementioned destabilization that is expected should support
renewed storm development near the advancing cold front -- initially
from Illinois southwestward to East Texas, and then spreading
eastward/expanding in coverage with time.

Along with the favorable thermodynamic environment within which the
storms will be evolving, highly favorable shear will also exist,
with low-level southerly/southwesterly flow veering and increasing
substantially with height yielding curved -- and then elongated --
hodographs. Supercells are expected within this environment, and
very large hail is expected given the cold air/steep lapse rates
through the mid troposphere. Along with the hail risk, damaging
wind gusts are expected -- particularly where upscale growth into
bands occurs. Additionally, this setup appears very favorable for
tornadoes, a few of which may be strong/potentially long-lived.

Risk will spread eastward with time into the evening/overnight.
Some diminishing of the risk should occur late into the upper Ohio
Valley, but vigorous storms and all-hazards risk will likely
continue through the end of the period across the Tennessee
Valley/Gulf Coast states.

The language suggests SPC is quite concerned. I expect a Moderate Risk for tomorrows Day 2 outlook. Not in the range of the HREF, SREF seems to maximize chances of tornadoes along the Mississippi River from S. Illinois to N. Louisiana.

[ravyrn]

This Severe Thunderstorm Warning was recently issued in Wisconsin in sub-freezing temps. I'm not sure I've ever seen a severe thunderstorm warning include freezing rain before.

Severe Thunderstorm Warning
National Weather Service Duluth MN
425 PM CDT Fri Mar 28 2025

The National Weather Service in Duluth MN has issued a

* Severe Thunderstorm Warning for...
Central Bayfield County in northwestern Wisconsin...
Northern Douglas County in northwestern Wisconsin...

* Until 530 PM CDT.

* At 423 PM CDT, a severe thunderstorm was located near Oliver, or 8
miles south of Superior, moving east at 55 mph.

HAZARD...Quarter size hail, accumulating hail, and freezing rain.

SOURCE...Trained weather spotters. At 414 PM...quarter size hail
was reported in Scotts Corner. Hail accumulated to a
depth of one inch.

IMPACT...Damage to vehicles is expected. Accumulated hail and
freezing rain will make roads slippery.

* This severe thunderstorm will be near...
South Range around 430 PM CDT.
Amnicon Falls State Park and Poplar around 435 PM CDT.
Maple around 440 PM CDT.
Lake Nebagamon around 445 PM CDT.
Brule around 450 PM CDT.
Oulu and Iron River around 455 PM CDT.
Ino around 510 PM CDT.

Other locations impacted by this severe thunderstorm include
Cloverland, Wentworth, Bennett, Mason, Blueberry, Waino, Moquah,
Amnicon Lake, Grand View, and Lyman Lake.

This storm will also impact US-53 between Superior and Solon Springs
and US-2 between Superior and Iron River.

[cycloneye]

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0115 AM CDT Sat Mar 29 2025

Valid 301200Z - 311200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS A BROAD
AREA CENTERED OVER THE OHIO/MID MISSISSIPPI/TENNESSEE VALLEYS...

...SUMMARY...
A widespread/substantial severe-weather episode is forecast across
an area centered on the Ohio/Mid and Lower Mississippi/Lower
Missouri/Tennessee River Valleys. Very large hail, damaging winds,
and strong tornadoes are expected.

...Midwest/Ohio Valley south to East Texas and the central Gulf
Coast states...
A mid-level short-wave trough is forecast to shift northeastward out
of the central Plains into the Upper Great Lakes region through the
first half of the period, with an accompanying surface low deepening
slowly as it reaches the Lake Michigan vicinity by early evening.
Meanwhile, a secondary short-wave trough -- comporised of several
vorticity maxima -- is forecast to move into/across the central and
southern Plains toward the Mississippi Valley through the second
half of the period, possibly driving weak frontal wave development
in the mid Mississippi/lower Ohio Valley vicinity by evening.

As the cold front crosses western Illinois/Missouri during the day,
daytime heating will support destabilization, yielding scattered
thunderstorm development, as the main/initial short-wave trough
crosses this region. Large hail and damaging winds will become
increasingly likely as the storms organize, and a few tornadoes will
also be possible. This convection may evolve into one or more bands
of organized storms with embedded rotation, with risk for more
widespread strong/damaging gusts, in addition to embedded tornadoes,
as the convection shifts across Indiana/southern Lower Michigan, and
eventually western Ohio through the evening and into the overnight
hours.

Farther south, more uncertainty exists -- due to questions regarding
degree of cloudiness and precipitation ahead of the approaching
front. NAM output suggests very steep lapse rates aloft will
overspread the area atop a capped/amply moist boundary layer. As
the front approaches, and effects of the secondary upper troughing
impinge gradually on the Lower Mississippi Valley area -- and
eventually the Mid South/Tennessee Valley, developing storms would
pose substantial, all-hazards severe risk including very large hail,
strong/damaging winds, and potentially strong tornadoes.

However, some models -- particularly the RAP -- suggest that
widespread precipitation/weak convection will persist through much
of the period across the lower Ohio/lower Mississippi/Tennessee
Valleys through the first half of the period, substantially
affecting the thermodynamic environment. Along with a
less-amplified upper flow field -- and weaker shear overall --
enough uncertainty exists to refrain from a higher-end outlook at
this time. As such, will maintain ENH risk across a broad area at
this time, though an upgrade to MDT risk in the lower
Ohio/Tennessee/Mid Mississippi Valley corridor may be required in
later outlooks.

[cycloneye]

Latest discussion for day 2. No moderate risk added.

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1228 PM CDT Sat Mar 29 2025

Valid 301200Z - 311200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS A BROAD
AREA CENTERED OVER THE OHIO/MID MISSISSIPPI/TENNESSEE VALLEYS...

...SUMMARY...
A widespread/substantial severe-weather episode is forecast across
an area centered on the Ohio/Mid and Lower Mississippi/Lower
Missouri/Tennessee River Valleys. Very large hail, damaging winds,
and strong tornadoes are expected.

...Synopsis...
Mid-morning water vapor imagery depicts an upper-level shortwave
trough across the Southwest that is the leading impulse within a
longwave trough building across the eastern Pacific/western CONUS.
This wave is expected to overspread the southern/central Plains
today before migrating into the Great Lakes region through the day
tomorrow. A secondary disturbance is expected to move into the
southern Plains late tomorrow evening into early Monday. At the
surface, the surface low analyzed across KS is forecast to intensify
as it moves northeast along a frontal zone into the Great Lakes in
tandem with the leading upper disturbance. The intensification of
the low will result in a cold frontal surge across the Midwest/OH
Valley tomorrow afternoon and across the Mid-MS Valley to Texarkana
region tomorrow evening. Scattered to widespread thunderstorm
development is anticipated along and ahead of the frontal zone with
the potential for widespread large hail/severe winds and several
tornadoes.

...Central TX...
Latest guidance suggests convection may be ongoing across central TX
along/ahead of a migratory dryline early Sunday morning. The
southern extent of a pronounced EML casts doubt on storm
coverage/longevity. However, buoyancy and deep-layer wind shear
should be supportive of supercells with an attendant severe
hail/wind threat if mature updrafts can develop along the boundary
as the primary upper-level trough axis passes over the region.

...IL, IN, and OH...
Consensus among recent forecast guidance is that kinematic fields
will steadily strengthen across the Midwest and middle OH River
Valley regions through the day as the surface low intensifies.
Increasing southerly flow ahead of the primary cold front should
allow for dewpoints in the upper 50s to low 60s to spread into the
region by mid-afternoon. Scattered thunderstorm development along
the cold front appears likely as early as 18-20z across IL, and
while a few initially discrete cells are possible, strong forcing
along the front should promote upscale growth into an organized line
by late afternoon. Strong low-level flow (nearly 50 knots 0-1 km
BWD) may promote bowing segments and embedded mesovorticies within
the line - especially across northern IN/northwest OH. 30% wind
probabilities have been expanded northward to account for this
potential.

While this is the most probable scenario based on morning guidance,
it could be complicated by any ongoing showers/thunderstorms and/or
remnant outflow boundaries associated with nocturnal convection over
MO late Saturday/early Sunday morning. This could limit diurnal
heating/destabilization or may provide pre-frontal foci for
convective initiation and promote more discrete storm modes.

...Mid-MS Valley to Texarkana region...
Scattered, initially discrete supercells are expected to develop
from the confluence of the OH/MS rivers southwestward into the
Texarkana region Sunday afternoon along the cold front and dryline.
Strong flow associated with the intensifying cyclone will promote
elongated hodographs featuring nearly uni-directional wind profiles
and effective bulk shear values on the order of 50-60 knots. This
will promote splitting supercells with the potential for large to
very large (2+ inch) hail. A more appreciable supercellular tornado
threat may emerge through early evening across the lower OH
Valley/mid-MS Valley where stronger veering in the lowest 1-2 km is
anticipated amid weak pre-frontal isentropic ascent between 925-850
mb. While the tornado threat may be maximized through this corridor,
low confidence in storm mode (due to the potential for splitting
cells/destructive interactions) limits confidence in this potential
to warrant higher probabilities at this time.

However, upscale growth is anticipated through mid/late evening as
the secondary upper disturbance migrates into the Texarkana region.
Consolidation of multiple clusters into one or more organized linear
segments is expected as storms push east towards the MS Valley with
a gradual increase in the potential for damaging/severe winds.
Additionally, low-level shear will remain favorable for embedded
mesovorticies as the line pushes into western TN/northern
MS/northwest AL through the overnight hours.

[cycloneye]

 https://x.com/NWSSPC/status/1906241612444823679

[cycloneye]

Valid 301630Z - 311200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
THE LOWER/MID MISSISSIPPI VALLEY INTO THE OHIO VALLEY AND SOUTHERN
GREAT LAKES...

...SUMMARY...
Numerous severe thunderstorms are expected through tonight across a
broad portion of the Southeast and lower/mid Mississippi Valley into
the Ohio Valley and southern Great Lakes. Multiple swaths of
widespread damaging winds appear likely. Large to very large hail
and several tornadoes will also occur with supercells. A few of
these tornadoes could be strong.

...Synopsis...
Water-vapor imagery late this morning shows a lead mid-level
shortwave trough moving quickly northeastward across MO, while an
upstream disturbance over the TX Panhandle/western OK rounds the
base of a larger-scale trough over the central U.S. Surface
analysis places a cyclone near the IA/IL/WI border with a trailing
cold front south-southwestward through the lower MO Valley and into
eastern OK and north TX. This front will push east through the OH
Valley and into the lower MS Valley by early Monday morning and
focus thunderstorm development.

...Midwest/Ohio Valley to the Great Lakes...
Visible-satellite imagery shows cloud breaks to the immediate east
of the lead mid-level disturbance as a moist/warm conveyor (40-kt
southwesterly LLJ) maintains a fetch of seasonably rich moisture
into the region. Additional thinning cloud cover and heating
through the early to mid afternoon will lead to thunderstorms
developing and intensifying. A belt of 50-80 kt 500-mb flow will
overspread the destabilizing airmass and yield ample deep-layer
shear for organized convection.

The stronger early storms will favor supercell and banded linear
modes, with the supercells posing a threat for large to very large
hail (around 1.5-2.5 inch diameter) given the presence of steep
mid-level lapse rates and favorable deep-layer shear. Meridional
upper-level flow from I-70 northward will favor a quicker transition
to linear structures compared to farther south/southwest, where
hodographs will promote a longer window of opportunity for cellular
(discrete and clusters) storm modes. The tornado risk will be
greatest with quasi-discrete supercells (potentially a few strong
tornadoes) near and south of the OH River, but some tornado threat
will probably develop with a squall line as it matures through the
afternoon/evening. As storm coverage increases, multiple swaths of
numerous to potentially widespread severe/damaging winds appear
likely as one or more clusters moves quickly east-northeastward over
the OH Valley and southern Lower MI. The threat for damaging winds
and tornadoes should continue this evening into the overnight hours,
until convection outpaces the low-level moisture return and
eventually weakens over the upper OH Valley and central
Appalachians.

...Central/East Texas into the Lower/Mid Mississippi
Valley/Mid-South and Southeast...
Strong destabilization is anticipated across the Ark-La-Tex east and
northeastward into the Mid South. Rich low-level moisture (mid to
upper 60s to around 70 deg F dewpoints) will stream northward across
TX ahead of the dryline, and the lower/mid MS Valley and Southeast
ahead of the cold front. Model guidance continues to indicate rapid
and intense thunderstorm development during the afternoon from parts
of north/east TX northeastward into AR. Supercells are expected
initially, with 40-50+ kt of deep-layer shear supporting robust
updraft organization and rotation. A favorable setup exists for
large to very large hail with the stronger supercells.

It appears the greatest risk for several tornadoes will focus
over parts of the Mid-South from eastern AR into western TN on the
southern periphery of an intensification of 850-mb flow towards
evening. Forecast soundings show moderate to locally strong
buoyancy (2000-3000 J/kg MLCAPE) on the northern rim of 66-68 deg F
dewpoints, and co-located with strong southwesterly flow veering to
westerly by early evening. It is during the 22-04 UTC period in
which forecast hodographs enlarge in the low levels and become more
favorable for discrete supercells. The strong tornado risk may
maximize within this corridor from parts of eastern AR eastward into
western and perhaps Middle TN during the evening. Additional severe
storms are probable farther south as activity from the Ark-La-Tex
moves east into the lower MS Valley and central Gulf Coast states
during the late afternoon into tonight. In addition to large to
very large hail, damaging gusts and a tornado risk will likely
accompany the stronger storms with a gradual lessening in overall
coverage and intensity during the late night.

...Florida Peninsula...
A weak mid-level perturbation will move eastward over FL this
afternoon. Modestly enhanced winds aloft, and a veering profile
with height through mid levels, should support sufficient deep-layer
shear for strong to severe multicells. The stronger diurnally
driven storms may be capable of severe hail and damaging winds.

[cycloneye]

 https://x.com/spann/status/1906481751620510188

[WaveBreaking]

IR/Veggie Sandwich image from a little earlier today

[cycloneye]

 https://x.com/NashSevereWx/status/1906528725484655006

[cycloneye]

[cycloneye]

For April 2.