RSS Mesoscale Discussions from Storm Prediction Center
WW 107 SEVERE TSTM MI LH LM 140310Z - 140900Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 107
NWS Storm Prediction Center Norman OK
1110 PM EDT Mon Apr 13 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Central Lower Michigan
Lake Huron
Lake Michigan
* Effective this Monday night and Tuesday morning from 1110 PM
until 500 AM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Scattered large hail events to 1.5 inches in diameter possible
SUMMARY...Thunderstorms will develop and overspread much of Lower
Michigan overnight as strong low-level winds overspread the area. A
few of the stronger storms will pose a risk of hail and damaging
winds.
The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 60 miles west southwest
of Manistee MI to 25 miles east of Bad Axe MI. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU7).
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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 105...WW 106...
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
27030.
...Hart
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WW 106 SEVERE TSTM IA MN WI LM 140240Z - 140900Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 106
NWS Storm Prediction Center Norman OK
940 PM CDT Mon Apr 13 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northeast Iowa
Southeast Minnesota
Southern Wisconsin
Lake Michigan
* Effective this Monday night and Tuesday morning from 940 PM
until 400 AM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Scattered large hail events to 1.5 inches in diameter likely
A tornado or two possible
SUMMARY...Lines and clusters of thunderstorms will persist overnight
across the watch area. Large hail and locally damaging wind gusts
are expected with this activity.
The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 30 miles south
southwest of Rochester MN to 45 miles north northeast of Milwaukee
WI. For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU6).
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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 103...WW 105...
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
27030.
...Hart
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WW 0107 Status Updates
STATUS REPORT ON WW 107
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 SW MBL TO
25 SSE TVC TO 25 NE TVC.
..DEAN..04/14/26
ATTN...WFO...APX...DTX...GRR...
STATUS REPORT FOR WS 107
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MIC011-017-035-039-049-051-057-063-073-085-087-101-105-107-111-
113-117-121-123-127-129-133-143-145-147-151-155-157-165-
140740-
MI
. MICHIGAN COUNTIES INCLUDED ARE
ARENAC BAY CLARE
CRAWFORD GENESEE GLADWIN
GRATIOT HURON ISABELLA
LAKE LAPEER MANISTEE
MASON MECOSTA MIDLAND
MISSAUKEE MONTCALM MUSKEGON
NEWAYGO OCEANA OGEMAW
OSCEOLA ROSCOMMON SAGINAW
ST. CLAIR SANILAC SHIAWASSEE
TUSCOLA WEXFORD
LCZ422-LHZ421-422-441-442-443-LMZ847-848-849-868-870-872-
140740-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
Read more
WW 0106 Status Updates
STATUS REPORT ON WW 106
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NNW DBQ
TO 10 E MSN TO 15 S OSH TO 30 SSW MTW TO 30 SW MBL.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0416
..DEAN..04/14/26
ATTN...WFO...ARX...GRB...MKX...
STATUS REPORT FOR WS 106
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
WIC025-027-039-045-055-059-065-079-089-101-105-117-127-131-133-
140740-
WI
. WISCONSIN COUNTIES INCLUDED ARE
DANE DODGE FOND DU LAC
GREEN JEFFERSON KENOSHA
LAFAYETTE MILWAUKEE OZAUKEE
RACINE ROCK SHEBOYGAN
WALWORTH WASHINGTON WAUKESHA
LMZ643-644-645-646-669-671-673-675-140740-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
SHEBOYGAN TO PORT WASHINGTON WI
PORT WASHINGTON TO NORTH POINT LIGHT WI
Read more
WW 0105 Status Updates
STATUS REPORT ON WW 105
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 60 SW SZL TO
15 E TOP.
..THOMPSON..04/14/26
ATTN...WFO...TOP...EAX...
STATUS REPORT FOR WT 105
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
KSC091-121-209-140340-
KS
. KANSAS COUNTIES INCLUDED ARE
JOHNSON MIAMI WYANDOTTE
MOC013-037-083-095-101-140340-
MO
. MISSOURI COUNTIES INCLUDED ARE
BATES CASS HENRY
JACKSON JOHNSON
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
Read more
MD 0417 CONCERNING SEVERE THUNDERSTORM WATCH 106...107... FOR FAR SOUTHEAST WI ACROSS SOUTHERN LAKE MICHIGAN INTO SOUTHERN LOWER MI
Mesoscale Discussion 0417
NWS Storm Prediction Center Norman OK
0150 AM CDT Tue Apr 14 2026
Areas affected...Far southeast WI across southern Lake Michigan into
southern Lower MI
Concerning...Severe Thunderstorm Watch 106...107...
Valid 140650Z - 140815Z
The severe weather threat for Severe Thunderstorm Watch 106, 107
continues.
SUMMARY...The damaging-wind threat may spread east-southeastward
into southern Lower Michigan through the early morning.
DISCUSSION...A fast-moving line segment with occasional embedded
circulations is moving across Milwaukee as of 0645 UTC. Area VWPs
(KMKX, KMKE, KGRR) all depict strong low-level southwesterly flow,
with 60+ kt noted at 1 km AGL. This strong low-level flow and
favorable deep-layer shear will continue to support organized storm
structures through the overnight hours. While MLCINH will continue
to gradually increase with time and eastward extent, a seasonably
warm and moist overnight boundary layer (with MLCAPE of greater than
1000 J/kg) may support a continued threat of damaging gusts into at
least southwest Lower MI, after the line crosses the lake. A
line-embedded tornado also remains possible, given the very strong
low-level shear/SRH.
Uncertainty remains regarding the longevity of the threat into a
larger portion of southern Lower MI, given the presence of a
more-stable boundary layer with eastward extent. However, with the
potential for strongly sheared convection to persist overnight,
local expansion of WW 107 and/or downstream watch issuance may be
needed.
..Dean/Smith.. 04/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DTX...IWX...GRR...LOT...MKX...
LAT...LON 43668786 43638604 43528460 42868402 42458402 42248422
41918480 41908537 41968633 42148702 42398767 42728843
43668786
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
Read more
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CDT Tue Apr 14 2026
Valid 141200Z - 151200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE MIDWEST...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
TO SOUTHERN PLAINS AND PARTS OF THE NORTHEAST...
...SUMMARY...
Severe thunderstorms are expected this afternoon through tonight
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 severe storms, mainly
producing strong wind gusts, will be possible across parts of the
Northeast this afternoon.
...Synopsis...
An upper wave is evident in recent water-vapor imagery across the
southern Great Basin. This trough will translate east into the
Plains through today, reaching the Great Lakes region by tonight.
This will support slight deepening of a diffuse surface low analyzed
over the central High Plains as it drifts east towards the lower MO
River Valley. Ahead of the low, an expansive warm sector
(characterized by widespread mid to upper 60s dewpoints) remains in
place from the southern Plains northeastward into the upper MS
Valley region. Strong to severe thunderstorms are expected along a
composite outflow boundary/warm front from eastern IA into southern
WI/northern IL as well as along a dryline draped from eastern KS
into OK and TX. Further east, a mid-level wave associated with
ongoing convection over the Great Lakes will support
re-intensification/re-development of strong/severe storms across the
Northeast.
...Midwest...
An outflow boundary emanating from the ongoing MCS across the Great
Lakes will likely be draped across the Midwest early this morning.
This boundary is forecast to drift northward within a southerly flow
regime as an effective warm front ahead of the approaching surface
low and upper wave. Latest guidance generally depicts this boundary
stalling across eastern IA into southern WI by late afternoon when
daytime heating and ascent ahead of the upper wave will erode
inhibition and promote convective initiation along the boundary.
Dewpoints in the mid to upper 60s coupled with steep mid-level lapse
rates (already noted in upstream 00z RAOBs) will support MLCAPE
values near 2500 J/kg by late afternoon. Moderate buoyancy combined
with 45-55 knots of effective bulk shear will be highly favorable
for organized convection. Capping at the base of the EML should
initially limit thunderstorm coverage and favor discrete supercells
along the boundary. In addition to very large hail (possibly up to
2-3 inches in diameter), enhanced low-level SRH along the boundary
may support a corridor of locally higher tornado potential,
including the potential for significant tornadoes. With time,
easterly storm motions along the boundary will promote upscale
growth with an increasing wind threat heading into the late evening
hours.
The primary uncertainty will be the location of the boundary by late
afternoon. 30% hail and 10% tornado probabilities were adjusted to
reflect the most likely placement of the boundary based on a
consensus of guidance; however, exact placement of the boundary will
be conditional on the precise evolution of the morning MCS.
Similarly, how quickly upscale growth occurs after initiation may
modulate the duration of the significant hail/tornado threat.
...Kansas into Oklahoma and Texas...
Modest height falls across the central to southern Plains combined
with weak convergence along the dryline will likely support isolated
to perhaps scattered thunderstorms from eastern KS southward into TX
this afternoon. Consensus among latest HREF/REFS guidance is that
initiation is most probable across northwest TX into central OK -
possibly ahead of a subtle mid-level wave, though in reality the
unfocused nature of the broad-scale ascent suggests that initiation
will be possible anywhere along the dryline where low-level
convergence can be maximized. Regardless, ample buoyancy within the
warm sector (2500-3000 J/kg MLCAPE sampled in evening RAOBs) coupled
with 30-40 knots of effective bulk shear will support supercells
with an attendant threat for large hail (possibly exceeding 2 inches
in diameter). Some tornado threat will likely materialize around and
after 00 UTC as the nocturnal jet strengthens and enlarges low-level
hodographs.
...Northeast...
A low-amplitude upper wave associated with an ongoing MCS across the
Great Lakes will migrate eastward towards the Northeast through the
day. Residual convection associated with the MCS may linger through
morning before re-intensifying by early afternoon as daytime heating
supports steepening low-level lapse rates and increasing MLCAPE
values (likely up to the 500-1000 J/kg range). While buoyancy will
likely remain weak, 35-40 knot bulk shear through the CAPE-bearing
layer and focused ascent ahead of a low-amplitude upper wave will
likely support organization of convective bands with an attendant
threat for strong to severe winds.
..Moore/Wendt.. 04/14/2026
Read more
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1255 AM CDT Tue Apr 14 2026
Valid 151200Z - 161200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE SOUTHERN PLAINS TO THE MIDDLE MISSISSIPPI VALLEY AND ACROSS
EASTERN 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 on Wednesday afternoon
and evening.
...Synopsis...
A shortwave upper trough will eject from the central Plains to the
Great Lakes on Wednesday. A swath of enhanced southwesterly
deep-layer flow will extend from the southern/central Plains to the
Great Lakes/Midwest ahead of this feature. The southern extent of
the upper trough will move more slowly east, from the southern
Rockies to the southern High Plains. At the surface, low pressure is
forecast to be in the vicinity of the Mid-MO Valley/southeast NE
Wednesday morning, and will shift east/northeast along a warm front
across IA/southern WI/northern IL through evening. A trailing cold
front will move across the Upper Midwest and Great Lakes vicinity
during the nighttime hours as the surface low continue to progress
northeast into Ontario. Further south, a dryline will extend
south/southwest across eastern KS into western OK and west-central
TX. A seasonally moist and unstable airmass will be in place ahead
of these surface features, focusing severe thunderstorm potential
during the afternoon and evening. A warm moist and unstable airmass
will extend eastward across portions of the upper Ohio
Valley/Northeast.
...MO Valley to Lake Michigan vicinity...
Convection is likely to be ongoing across parts of the region
Wednesday morning. As a result, uncertainty exists regarding airmass
recovery and evolution of severe potential Wednesday
afternoon/evening. Persistent southwesterly flow and warm advection
ahead of the surface low will maintain a moist airmass. Convection
should redevelop by late afternoon/evening near the surface low and
along a surface boundary extending from eastern IA to near the IL/WI
border. Where heating can occur in the wake of early day convection,
MLCAPE around 1000-2000 J/kg should develop. Supercell wind profiles
are evident in forecast soundings, especially near the surface low
where SRH will be enhanced. Initial cells may pose a risk for hail.
Tornado potential is a bit more uncertain given aforementioned
concerns about boundary-layer impacts from early day convection.
However, at least low potential should exist near the surface low
and warm front/outflow. A corridor of higher tornado probabilities
may be needed in subsequent outlooks if confidence in mesoscale
details and boundary layer recovery increases. During the evening,
upscale growth into an eastward-advancing line is expected as a
surface cold front begins to move east across the region, and
damaging winds will be possible.
...Southern Plains...
Isolated supercells are forecast to develop along the dryline in OK
into eastern KS/ and eventually portions of MO. Mid to upper 60s F
dewpoints beneath steep midlevel lapse rates (7.5-8 C/km) will
support 2000-3000 J/kg MLCAPE by afternoon. Some weak capping is
noted around 850 mb, which may limit storm coverage in the absence
of stronger large-scale ascent. Nevertheless, elongated/straight
hodographs above 2-3 km within a favorable thermodynamic environment
suggests large to very large hail will be possible with storms that
develop. A couple of tornadoes also will be possible given modestly
enlarged and favorably curved low-level hodographs and around 150
m2/s2 SRH within a narrow corridor near the dryline.
...Upper Ohio Valley toward the Northeast...
Fast deep-layer west/southwesterly flow will overspread a moistening
low-level boundary layer. Strong heating will support steepening
low-level lapse rates and cool temperatures aloft will support
midlevel lapse rates near 7 C/km. This will foster moderate
destabilization during the afternoon, promoting isolated to widely
scattered thunderstorm development. Damaging wind gusts and isolated
hail will be possible with this activity into the evening.
..Leitman.. 04/14/2026
Read more
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0129 AM CDT Tue Apr 14 2026
Valid 141200Z - 151200Z
...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST COLORADO AND ADJACENT
HIGH PLAINS...
...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.
..Wendt.. 04/14/2026
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0130 AM CDT Tue Apr 14 2026
Valid 151200Z - 161200Z
...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.
..Wendt.. 04/14/2026
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
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