ACUS48 KWNS 280858
SWOD48
SPC AC 280856

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0356 AM CDT Tue Apr 28 2026

Valid 011200Z - 061200Z

...DISCUSSION...
Medium-range guidance indicates that the evolving split flow may
maintain a broadly confluent mid-level regime across and east of the
Rockies through this period. While a broad area of lower mid-level
heights remains centered across the Ontario/Quebec and Upper Midwest
through Northeast, it appears that a more prominent blocking
ridge/high may evolve upstream near the British Columbia/Pacific
Northwest coast by late this coming weekend into early next week. A
developing low to its southeast may slowly progress inland across
California into the Southwest, with downstream mid-level ridging
building across the Rockies.

There is considerable model spread concerning embedded short wave
developments, but it appears that potential for stronger convection
will remain generally low for the time of year and confined to parts
of the southern tier of the U.S., perhaps including parts of the San
Joaquin Valley, as well as along a lingering frontal zone near or
just south of the Gulf into southern Atlantic coastal plain. Due to
a combination of low predictability and low severe weather
potential, severe weather probabilities are being maintained at less
than 15 percent through this period.

..Kerr.. 04/28/2026

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ACUS48 KWNS 280925
SWOD48
SPC AC 280923

Day 4-8 Convective Outlook RESENT 1
NWS Storm Prediction Center Norman OK
0423 AM CDT Tue Apr 28 2026

Valid 011200Z - 061200Z

...DISCUSSION...
Medium-range guidance indicates that the evolving split flow may
maintain a broadly confluent mid-level regime across and east of the
Rockies through this period. While a broad area of lower mid-level
heights remains centered across the Ontario/Quebec and Upper Midwest
through Northeast, it appears that a more prominent blocking
ridge/high may evolve upstream near the British Columbia/Pacific
Northwest coast by late this coming weekend into early next week. A
developing low to its southeast may slowly progress inland across
California into the Southwest, with downstream mid-level ridging
building across the Rockies.

There is considerable model spread concerning embedded short wave
developments, but it appears that potential for stronger convection
will remain generally low for the time of year and confined to parts
of the southern tier of the U.S., perhaps including parts of the San
Joaquin Valley, as well as along a lingering frontal zone near or
just south of the Gulf into southern Atlantic coastal plain. Due to
a combination of low predictability and low severe weather
potential, severe weather probabilities are being maintained at less
than 15 percent through this period.

..Kerr.. 04/28/2026

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ACUS48 KWNS 290900
SWOD48
SPC AC 290858

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0358 AM CDT Wed Apr 29 2026

Valid 021200Z - 071200Z

...DISCUSSION...
Latest medium-range guidance, in particular the ECENS and GEFS,
generally maintains forecast trends of prior runs concerning the
evolution of the large-scale features within the prevailing split
flow through this weekend into early next week. It appears that at
least a transient blocking high may evolve within amplified ridging
offshore of the British Columbia and adjacent Pacific Northwest
coast. To its south-southeast a notable mid-level low is forecast
to evolve within initial troughing slowly digging toward the U.S.
Pacific coast, with the low bottoming out offshore of the central/
southern California coast by early next week.

Downstream, it appears that a broad area of lower mid-level heights
will be maintained, with lowest heights perhaps reforming
west-northwestward from southwestern Quebec toward southern Hudson Bay/northwestern Ontario, contributing to the maintenance of a
confluent regime across and east of the Rockies.

Shorter wavelength developments within this pattern remain more
uncertain, particularly by the early to middle portion of next week,
when it appears that the offshore low will begin to progress inland
across California and the southern Sierra Nevada. Depending on the
timing of the inland progressing mid-level cold core with respect to
diurnal heating, this could be accompanied by relatively minor
severe weather potential across parts of the San Joaquin Valley next
Monday or Tuesday.

Downstream, southerly moist return flow into at least the southern
through central Great Plains, associated with deepening lee surface
troughing, may contribute to destabilization beneath building
mid-level ridging across and east of the southern Rockies. This
might be accompanied by increasing potential for at least widely
scattered strong to severe thunderstorm development on Tuesday.

Guidance suggests potential for more widespread organized severe
thunderstorm development could increase by Wednesday, but much will
depend on short wave developments which become rather uncertain by
this time.

..Kerr.. 04/29/2026

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ACUS48 KWNS 300902
SWOD48
SPC AC 300900

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Thu Apr 30 2026

Valid 031200Z - 081200Z

...DISCUSSION...
Late this coming weekend into early next week, it still appears that
at least a transient blocking high may continue to evolve offshore
of the British Columbia/Pacific Northwest coast. It remains a bit
uncertain how long this will persist before becoming suppressed, and
an evolving low to its southeast is forced inland across southern
California into the Southwest.

Latest medium range guidance continues to indicate that it is
possible that a short wave perturbation could emerge from the
remnant low/troughing, in advance of another significant short wave
impulse emerging from the higher latitudes before amplifying
southeastward to the lee of the Rockies, through the Atlantic
Seaboard by the end of the period. However, it now appears probable
that modest troughing, perhaps with a continuing cyclonic
circulation, will linger near and south of the Southwestern
international border.

In lower levels, southerly moist return flow may commence by early
next week across the southern into central Great Plains as surface
troughing deepens to the lee of the Rockies. This may begin to more substantively advect northeastward toward the Ohio Valley, in
advance of a southward advancing cold front associated with the
digging mid-level troughing. However, there is notable spread among
the model output concerning potential surface cyclogenesis, near
and northeast of the Rockies.

Widely scattered strong to severe thunderstorm development appears
possible from parts of the central and southern Great Plains into
the Mississippi Valley by Tuesday, if not Monday. However,
inhibition associated with warm elevated mixed-layer air
overspreading the southern Great Plains may become a limiting
factor, as low-level moisture becomes more supportive of strong destabilization.

There remains at least some signal in the model output for
potentially more widespread strong to severe thunderstorm
development across the lower/middle Mississippi Valley into Ohio
Valley by next Wednesday, perhaps into Thursday. However, with
uncertainties remaining sizable at this extended time frame, severe probabilities still appear less than 15 percent.

..Kerr.. 04/30/2026

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ACUS48 KWNS 010736
SWOD48
SPC AC 010734

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0234 AM CDT Fri May 01 2026

Valid 041200Z - 091200Z

...DISCUSSION...
...Days 4-6/Mon-Wed -- Southern Plains...Mid/Lower MS
Valley...Southeast...

An upper trough will develop southward across the northern Plains
and Upper Midwest on Monday. At the same time, another upper trough
will be oriented over southern CA and offshore over the Pacific. In
response to modest height falls and increasing westerly flow across
the Rockies, a lee low will develop over the central/southern High
Plains. Increasing southerly low-level flow will allow modified Gulf
moisture to return northward ahead of a dryline across the southern
Plains, and to the south of a cold front developing southward across
the central Plains and Upper MS Valley. Isolated strong to severe
thunderstorms will be possible within the narrow moist/warm sector
ahead of these surface boundaries, particularly the cold front
across parts of the MO/Mid-MS Valley, as capping may persist further
south across the Southern Plains. Given modest boundary moisture
with north and east extent across the Midwest, it is uncertain how
robust convection may be and where the most favorable area for
severe storms may develop, precluding 15 percent probabilities at
this time for Day 4/Mon.

By Day 5/Tue, the jet associated with the eastward advancing
Southwest U.S. trough will being to phase with the upper trough over
the north-central U.S. This will bring strengthening southwesterly
flow to portions of the southern Plains and Mid-South vicinity while southwesterly low-level flow continues to transport Gulf moisture north/northeast ahead of a southeastward-advancing surface cold
front. The warm sector will become increasingly narrow toward the
Lower Ohio Valley, and any strong to severe thunderstorm potential
would likely focus from parts of Texas into Arkansas/far western
TN/KY. However, model guidance varies with regard to placement and
extent of potential convection ongoing Tuesday morning, which will
have implications for severe potential through the rest of the day.
Differences in the location of the surface front also add
uncertainty, precluding a 15 percent delineation.

Some strong to severe thunderstorm potential could persist into Day
6/Wed across parts of the Lower MS Valley and southeastern U.S. This
remains uncertain and will be influenced by convective evolution in
the days prior.

...Days 7-8/Thu-Fri...

The surface cold front is expected to move offshore the East Coast
on Day 7/Thu. Thunderstorm potential will continue ahead of the
front across the Southeast to the Mid-Atlantic, but severe potential
is uncertain as destabilization may be limited by widespread
rainfall and cloud cover. On Day 8/Fri, most of the CONUS will be
stable/dry behind the cold frontal passage. However, guidance
suggests a shortwave upper trough will approach the southern
Rockies/northern Mexico and surface cyclogenesis will maintain a
moist airmass across TX. If this occurs, some severe potential could
develop across parts of TX.

..Leitman.. 05/01/2026

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ACUS48 KWNS 020756
SWOD48
SPC AC 020755

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0255 AM CDT Sat May 02 2026

Valid 051200Z - 101200Z

...DISCUSSION...
...Days 4-5/Tue-Wed -- Southeast OK/ArkLaTex to Lower MS/TN
Valleys...

Southwesterly deep-layer flow will increase from the southern
Rockies to the Mid-South on Day 4/Tuesday as a southern stream
shortwave trough over the Southwest merges with an upper trough over
the Plains/Upper Midwest. At the surface, low pressure will develop
over the southern Plains and slowly progress east in AR as a cold
front develops southeast across OK/AR and the Lower OH Valley. Ahead
of the front, rich Gulf moisture will return northward, and 60s to
near 70 F dewpoints are forecast by Tuesday afternoon/evening across
southeast OK and the ArkLaTex. Timing of thunderstorm development is
a bit uncertain as shortwave ridging may overspread the southern
Plains vicinity through afternoon. However, forcing for ascent
should increase with the approach of the surface front and as a
low-level jet increasing Tuesday evening. Moderate instability and
strong vertical shear should support severe thunderstorm activity
near the cold front from late afternoon into Tuesday night.

On Day 5/Wednesday, the Plains upper trough will migrate east,
extending from the Upper Great Lakes to the Lower MS Valley by early
Thursday. The surface cold front will extend from the OH Valley into north/central TX Wednesday morning and slowly progress southeast
through the period. Gulf moisture will return north and east across
the southern U.S. ahead of the front. While deep-layer flow will
largely be parallel to the surface front, moist and unstable airmass
ahead of the front should support some risk for severe
thunderstorms.

...Days 6-8/Thu-Sat...

A deepening surface low will develop northward across the
Mid-Atlantic and Northeast on Thursday as a surface cold front
continues to shift east across much of the eastern U.S. While a
moist airmass will be in place across parts of the Southeast to the Mid-Atlantic, it is uncertain how much destabilization will occur
due to possibly widespread thunderstorm activity and cloud cover
(particularly from the Mid-Atlantic northward). Large-scale ascent
will become increasingly displaced to the north across the
Southeast, and convection may tend to be anafrontal. Trends will be
monitored and severe probabilities could become necessary for parts
of the eastern U.S. on Thursday in later outlooks.

Severe potential will be limited on Friday as the prior cold frontal
passages clears out Gulf moisture and surface high pressure envelops
much of the eastern half of the U.S. Weak upper troughing could
overspread the Rockies and High Plains by the end of the period,
allowing for Gulf moisture return across the Plains and an increase
in thunderstorm potential.

..Leitman.. 05/02/2026

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ACUS48 KWNS 030752
SWOD48
SPC AC 030750

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0250 AM CDT Sun May 03 2026

Valid 061200Z - 111200Z

...DISCUSSION...
...Day 4/Wed -- East TX to the Lower MS and TN Valley vicinity...

Strong southwesterly deep-layer flow will overspread the region
ahead of an upper trough pivoting east across the Plains toward the
Mid-MS Valley. At the surface, a cold front will be oriented from
the OH Valley to southern AR and central TX. Ahead of the front,
rich Gulf moisture will be in place across southern and eastern TX
into the Lower MS Valley eastward toward AL. Moderate to strong
destabilization is expected across the warm sector ahead of the southward-sagging cold front. Supercell wind profiles are evident in
forecast soundings. However, given linear forcing along the front
and deep-layer flow largely parallel to the boundary, it is
uncertain if discrete storms will be possible. Nevertheless, severe
potential is still expected with clusters and linear segments given
the favorable thermodynamic environment and strong vertical shear.

...Day 5/Thu - South TX and parts of the Southeast...

Some severe potential could persist into Thursday across south TX as
the cold front continues to develop southward across a very moist
and unstable airmass. However, large-scale ascent may be limited as
forcing associated with the eastern U.S. upper trough focuses well
northeast of the region. Shortwave upper ridging also may overspread
region ahead of an upper low/trough over northwest Mexico.

Additional strong or severe storms will be possible across parts of
the Southeast toward the Carolinas and Mid-Atlantic as the cold
front shifts east across that region. However, widespread
showers/thunderstorms and cloud cover may limit destabilization, and
convection could become anafrontal by this time.

...Days 6-8/Fri-Sun...

Spread beings to increase across model guidance by the weekend,
though mean upper troughing across the East seems likely to persist.
This typically would not be ideal for severe potential. However, an
upper shortwave trough is forecast to move across the southern
Rockies into the southern Plains. Forecast guidance varies widely
with the timing and evolution of these features however, and
predictability is low.

..Leitman.. 05/03/2026

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ACUS48 KWNS 040732
SWOD48
SPC AC 040730

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 AM CDT Mon May 04 2026

Valid 071200Z - 121200Z

...DISCUSSION...
Large-scale upper troughing is expected to envelop much of the
eastern half of the CONUS for most of the forecast period. On Day
4/Thu, a surface cold front is expected to extend from the southern Mid-Atlantic to the central Gulf coast and southern TX. The front
should largely move offshore the Gulf and Atlantic coasts and over
northern FL by early Day 5/Fri. A moist airmass will be in place
ahead of the front and some severe thunderstorm potential could
develop. However, 15 percent or greater coverage is uncertain given
deep-layer flow parallel to the boundary, cloud cover and areas of showers/thunderstorms early Thursday, and large-scale ascent lifting
northeast away from better low-level moisture.

Severe potential appears low Days 5-6/Fri-Sat. Boundary layer
moisture will be limited due to the prior cold frontal passage and
surface high pressure in its wake. Some guidance suggests a weak
shortwave trough will migrate across the southern Rockies and
southern Plains on Friday, resulting in lee troughing and some Gulf
moisture return across TX Friday night into Saturday. This could
bring an increasing chance for thunderstorms across portions for TX
and perhaps the Lower MS Valley on Saturday, though severe potential
is uncertain given large model spread. By early next week, another
period of moisture return ahead of a shortwave trough ejecting from
the Rockies into the Plains/Midwest could bring another bout of
severe potential ahead of a cold front from the southern Plains to
the Southeast. However, timing and intensity of these features
varies across control, AI, and ensemble guidance, resulting in low predictability.

..Leitman.. 05/04/2026

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ACUS48 KWNS 050734
SWOD48
SPC AC 050732

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0232 AM CDT Tue May 05 2026

Valid 081200Z - 131200Z

...DISCUSSION...
Mean upper troughing will persist east of the Rockies for the Day
4-8 period. This will largely suppress northward transport of Gulf
moisture, except periodically across the southern Plains and
Southeast/Gulf coast states. Severe potential is expected to be low
on Day 4/Fri as surface high pressure dominates in the wake of a
prior cold frontal passage offshore the Gulf and Atlantic coasts. On
Day 5/Sat, lee troughing will allow for increasing
south/southeasterly low-level flow across the southern Plains and
Lower MS Valley, aiding in moisture return across these areas. This
could result in thunderstorm potential across the south-central
U.S., but severe potential is limited given a lack of stronger
forcing for ascent. By Days 6-7/Sun-Mon, another cold front is
forecast to move east/southeast across much of the U.S. east of the
Rockies. As the front impinges on a moist airmass across the
southern Plains to the Southeast and Mid-Atlantic, some severe
potential could develop. However, mid to upper-level flow is not
forecast to be overly strong and medium range guidance varies quite
a bit with respect to moisture and cold front timing, resulting in
low predictability.

..Leitman.. 05/05/2026

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ACUS48 KWNS 060744
SWOD48
SPC AC 060742

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0242 AM CDT Wed May 06 2026

Valid 091200Z - 141200Z

...DISCUSSION...
An upper shortwave trough will be located over TX on Day 4/Saturday.
Meanwhile, another upper shortwave trough will migrate from the
central Rockies into the into the central Plains on Saturday. These
features will result in modestly increasing mid/upper level
northwesterly flow across the Plains. At the surface, modest
southerly low-level flow will continue to transport Gulf moisture
northward across the southern Plains and Lower MS Valley. Weak
surface cyclogenesis is possible across the central/southern Plains
and a dryline will extend across western KS/OK/TX. This could be a
focus for thunderstorm development on Saturday. However, how far
north quality moisture return will occur (especially before Saturday night/early Sunday) is uncertain. Additionally, deep-layer flow is
not forecast to be very strong. While some strong to severe
thunderstorms could develop, confidence is too low to include severe probabilities.

By Day 5/Sunday, a large scale upper trough over the Plains will
shift east, extending from the lower Great Lakes to the eastern Gulf
by Monday morning. A surface low will move from the Midwest to the
eastern U.S. while a trailing cold front develops southeast across
the southern Plains and the Mid/Lower MS and OH Valleys. Ahead of
the front, a moist airmass will be in place across the south-central
to Southeast U.S. However, it is uncertain how much destabilization
will occur as widespread precipitation and cloud cover are possible.
Some strong to severe thunderstorm potential could develop, but
predictability is low at this time.

Heading into Days 6-8/Mon-Wed, mean troughing is likely to continue
across the East with broad northwesterly flow across the Plains. The
cold frontal passage on Sunday will likely suppress Gulf moisture on
Monday. Another cold front is forecast to move across portions of
the Plains and Midwest on Tuesday and any severe potential will
depend on timing and quality of moisture return into the central
U.S., which is uncertain. Overall, predictability is low late in the
forecast period.

..Leitman.. 05/06/2026

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ACUS48 KWNS 070730
SWOD48
SPC AC 070728

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0228 AM CDT Thu May 07 2026

Valid 101200Z - 151200Z

...DISCUSSION...
A progressive upper-level pattern is forecast during the Day
4-8/Sun-Thu period. Early in the period, an upper trough will move
from the Plains to the eastern U.S. through Day 5/Mon. Stronger
northwesterly flow will overspread the Plains during this time,
while a cold front will sag southward across TX and Gulf Coast
states. This will suppress boundary layer moisture across much of
the CONUS, but could bring some potential for strong thunderstorms
to parts of TX and the Southeast, though severe thunderstorm
potential appears marginal.

By Day 6/Tue, a deepening surface low is forecast across the central
Plains as a weak shortwave impulse migrating through northwesterly
flow aloft glaces the region. Increasing southerly low-level flow
will begin to transport Gulf moisture northward across portions of
the central U.S. through Day 7/Wed, and some increase in
thunderstorm potential is expected. At the same time an upper ridge
will begin to emerge over the Plains, which could lead to capping. Additionally, quality of moisture return is uncertain with northward
extent. Overall, severe potential appears marginal throughout the
Day 4-8/Sun-Thu period.

..Leitman.. 05/07/2026

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ACUS48 KWNS 080833
SWOD48
SPC AC 080831

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0331 AM CDT Fri May 08 2026

Valid 111200Z - 161200Z

...DISCUSSION...
...Monday/Day 4 to Wednesday/Day 6...
Mid-level northwesterly flow is forecast to persist across much of
the central and eastern U.S. during the period from Monday to
Wednesday. A cold front is forecast to move through the Southeast on
Monday and into the Gulf and Florida on Tuesday and Wednesday.
Isolated severe thunderstorm development will be possible near and
ahead of the front each day, with the greatest potential for severe
Monday afternoon and evening in parts of southern Alabama, southern
Georgia, northern Florida and the coastal Carolinas. Isolated severe
wind gusts is expected to be the primary threat.

Further to the north on Tuesday, another cold front is forecast to
move southward through the central Plains and mid Mississippi
Valley. Although low-level moisture is forecast to remain somewhat
limited, enough instability could develop for an isolated severe
threat. The greatest potential would be in eastern Missouri and
southern Illinois in conjunction with a mid-level jet moving
southeastward through the region. Hail and isolated severe gusts
will be possible. A marginal severe threat could again develop near
the associated trough over the central Appalachians Wednesday
afternoon.

...Thursday/Day 7 and Friday/Day 8...
A shortwave ridge is forecast to move eastward toward the
Mississippi Valley on Thursday, as another shortwave ridge moves
into the High Plains on Friday. In the wake of each ridge, model
forecasts develop a north-to-south axis of instability in the Great
Plains. Isolated severe storms will be possible within this unstable
airmass on both Thursday and Friday. At this time, uncertainty is
substantial late in the day 4 to 8 period.

..Broyles.. 05/08/2026

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ACUS48 KWNS 090844
SWOD48
SPC AC 090843

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0343 AM CDT Sat May 09 2026

Valid 121200Z - 171200Z

...DISCUSSION...
...Tuesday/Day 4 and Wednesday/Day 5....
On Tuesday and Wednesday, northwesterly mid-level flow will be in
place over the central U.S. A shortwave trough is forecast to move southeastward into the upper Mississippi Valley on Tuesday, and into
the central Appalachians on Wednesday. Isolated severe thunderstorms
will be possible ahead of the trough each day, but weak instability
should keep any severe threat marginal.

...Thursday/Day 6 to Saturday/Day 8...
On Thursday, a shortwave ridge is forecast to move eastward across
the central U.S. A north-to-south axis of instability is forecast to
develop in the wake of the ridge across the Great Plains. Isolated
severe storms will be possible along parts of this corridor Thursday
afternoon and evening.

On Friday, a subtle shortwave trough is forecast to move eastward
across the central U.S. Moderate deep-layer shear is forecast to be
in place over a moist and unstable airmass from eastern Kansas
southward into Oklahoma, where isolated severe storms may develop
during the afternoon and evening.

On Saturday, strong low-level moisture advection is forecast to
develop over the south-central U.S., as a mid-level shortwave trough
moves into the southern Plains. Near this trough, scattered
thunderstorm development will be possible. Moderate deep-layer shear
and instability should be favorable for an isolated severe threat
during the afternoon and evening, mainly from Oklahoma southward
into west-central Texas.

Considering the last few days of the Day 4 to 8 period, recent
models have shown substantial variability from run to run. Scenarios
have been outlined based on model consensus. However, confidence is
low concerning potential outcomes, especially this upcoming weekend.

..Broyles.. 05/09/2026

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ACUS48 KWNS 100844
SWOD48
SPC AC 100842

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0342 AM CDT Sun May 10 2026

Valid 131200Z - 181200Z

...DISCUSSION...
...Wednesday/Day 4 to Friday/Day 6...
An upper-level trough is forecast to move into the eastern U.S. on
Wednesday and become substantially amplified. Ahead of the trough,
enough instability is expected to develop in the central
Appalachians Wednesday afternoon for an isolated severe threat.

On Thursday, a mid-level shortwave ridge is forecast to move through
the central U.S. An axis of instability appears likely to develop in
the Great Plains in the wake of the ridge. Although an isolated
severe threat will be possible along parts of this instability
corridor Thursday afternoon, model forecasts suggest a cap will
minimize convective coverage.

The ridge is forecast to move into the Ohio Valley and Great Lakes
on Friday, as a mid-level shortwave trough moves into the
north-central states. Isolated severe storms could occur ahead of
this trough in the northern Plains and upper Mississippi Valley
Friday afternoon. Additionally, a conditional severe threat could
develop southward into the southern and central Plains, but this
would materialize only if storms can initiate in a somewhat capped
environment.

...Saturday/Day 7 and Sunday/Day 8...
On Saturday and Sunday, a moist and unstable airmass is forecast to
gradually advect northward across the southern and central Plains.
Isolated to scattered storms will be possible each afternoon over
parts of this airmass. However, large-scale ascent is forecast to
remain limited and convective initiation will likely be
mesoscale-driven. For this reason, predictability is low over the
weekend concerning any potential for severe storms.

..Broyles.. 05/10/2026

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ACUS48 KWNS 110820
SWOD48
SPC AC 110818

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0318 AM CDT Mon May 11 2026

Valid 141200Z - 191200Z

...DISCUSSION...
...Thursday/Day 4 to Saturday/Day 6...
At mid-levels, a shortwave ridge is forecast to pass eastward
through the north-central U.S. on Thursday. A shortwave trough is
forecast to move into the Great Plains, with moisture and
instability located in the central Plains. Although most of the
airmass is forecast to be capped during the day, a few storms with
an isolated severe threat will be possible in areas that heat up the
most.

On Friday, a mid-level ridge is forecast to move eastward across the
Great Plains, as a moisture and instability advects northeastward
into the lower to mid Missouri Valley. Isolated to scattered
thunderstorms will be possible within this airmass in the afternoon
and evening. Hail and isolated severe gusts would be the primary
threats.

By Saturday, a wide corridor of moderate instability is forecast to
be in place over the Great Plains. A shortwave trough is forecast to
move into the central U.S. during the afternoon. Ahead of the
shortwave, scattered thunderstorms will be possible from north Texas
northward into Nebraska. Along the western edge of the instability
corridor, steep mid-level lapse rates and moderate deep-layer shear
are forecast. The environment could support large hail, damaging
wind gusts and an isolated tornado threat in the southern and
central Plains where instability, shear and lift are forecast to
become maximized.

...Sunday/Day 7 and Monday/Day 8...
On Sunday, mid-level flow is forecast to be southwesterly over the
central U.S., as a shortwave trough moves into the Great Lakes.
Another shortwave trough is forecast to move into the northern High
Plains. Further south in the southern and central Plains, moderate
to strong instability is forecast to be in place by midday.
Thunderstorm development is expected over parts of this unstable
airmass in the afternoon and evening. Although uncertainty exists
concerning the location of the greatest severe threat, some
solutions suggest potential for a large complex of storms from
eastern Kansas into Missouri. At this time, too much uncertainty
exists for the addition of a severe threat area.

On Monday, a front is forecast to advance southeastward across the
central U.S. Ahead of this front, isolated severe storms will be
possible near an axis of instability in the afternoon and evening.
However, model spread is relatively large concerning the timing of
features at this extended range.

..Broyles.. 05/11/2026

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ACUS48 KWNS 120858
SWOD48
SPC AC 120857

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0357 AM CDT Tue May 12 2026

Valid 151200Z - 201200Z

...DISCUSSION...
...Friday/Day 4 to Sunday/Day 6...
Over the weekend, mid-level flow is forecast to gradually become
southwesterly across the central U.S. In response, low-level
moisture advection will occur in the Great Plains. By Friday
afternoon, a moist and unstable airmass is forecast to be in place
from north Texas into Oklahoma, eastern Kansas and central to
northern Missouri. Isolated severe storms will be possible within
this airmass Friday afternoon and evening.

On Saturday, a dryline is forecast to develop from the far eastern
Texas Panhandle northward into west-central Kansas. To the east of
the dryline, surface dewpoints in the 60s F will contribute to
moderate instability by afternoon. As a mid-level shortwave trough
approaches in the afternoon, scattered thunderstorms are expected to
form to the east of the dryline from western Oklahoma into central
and eastern Kansas. Supercells with large hail, severe wind gusts,
and a tornado threat could develop.

A surge of deeper low-level moisture is expected across the southern
and central Plains on Sunday, as an upper-level trough moves through
the western U.S. In response, a north-to-south corridor of strong
instability is forecast by afternoon from western Oklahoma north and northeastward into central and eastern Kansas. Scattered
thunderstorms are expected within this unstable airmass during the
afternoon and evening. MCS development may occur in the evening as a
complex moves northeastward from the central Plains into the mid
Missouri Valley. Supercells with large hail, severe wind gusts and a
tornado threat will be possible.

...Monday/Day 7 and Tuesday/Day 8...
An upper-level trough is forecast to move across the north-central
U.S. on Monday, as a cold front advances southeastward into the mid
Mississippi Valley, Ozarks and southern Plains. Scattered to
numerous thunderstorms are forecast to form ahead of the front in
the afternoon. At this time, model forecasts suggest that
instability and deep-layer shear will be strong enough for severe
storms across a broad area. However, uncertainty exists concerning
the location of the front Monday afternoon. A severe threat area may
be needed in later Outlooks, once confidence increases concerning
the timing of the front.

On Tuesday, the cold front is forecast to move southward into north
Texas and the southern Ozarks. An isolated severe threat could
develop ahead of the front in the afternoon and evening. However,
uncertainty is substantial at this extended range.

..Broyles.. 05/12/2026

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ACUS48 KWNS 130859
SWOD48
SPC AC 130857

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0357 AM CDT Wed May 13 2026

Valid 161200Z - 211200Z

...DISCUSSION...
...Saturday/Day 4 to Monday/Day 6...
At mid-levels, a shortware trough will move eastward across the
western U.S. on Saturday, as flow becomes west-southwesterly over
much of the central U.S. In response, moisture advection is forecast
to increase over the central U.S. as a pocket of 65 to 70 F
dewpoints moves northward into the lower and mid Missouri Valley. A
dryline is forecast on the western edge of the moist airmass.
Isolated to scattered storms appear likely to initiate to the east
of the dryline in the afternoon. Additional storms may form eastward
across the lower to mid Missouri Valley. Moderate deep-layer shear
is forecast over the instability axis, which should support a
potential for supercells with large hail and severe wind gusts.

On Sunday, an upper-level trough is forecast to develop over the
western U.S. Mid-level flow is expected to become southwesterly over
the Great Plains, where model forecasts show a surge of low-level
moisture. In response, surface dewpoints are forecast to increase
into the mid to upper 60s F over much of the north-central U.S. A
series of subtle shortwave troughs moving through the Great Plains
will likely support scattered to numerous thunderstorms in the
afternoon and evening. The greatest severe threat may develop over
eastern Nebraska and western Iowa, along the northern edge of a
low-level jet. A potential for supercells with large hail, wind
damage and a tornado threat is expected.

On Monday, the upper-level trough is forecast to move across the
Intermountain West, as multiple shortwave impulses move
northeastward across the Great Plains. A cold front is forecast to
move southeastward across the central U.S. Ahead of the front,
surface dewpoints in the lower to mid 70s F are forecast to be in
place by afternoon. In response, strong instability is expected to
develop in parts of the moist airmass. In addition, a mid-level jet
is forecast to eject northeastward across the central U.S. Moderate
to strong deep-layer shear associated with the jet will support a
potential for severe storms across a broad area from the southern
Plains northeastward into the Upper Midwest. Supercells and bowing
line segments with large hail, severe wind gusts and tornadoes will
be possible.

...Tuesday/Day 7 and Wednesday/Day 8...
On Tuesday and Wednesday, a cold front is forecast to move from the
Upper Midwest southeastward into the Appalachians. A moist and
unstable airmass will likely be in place ahead of the front, with
scattered to numerous thunderstorms likely developing each afternoon
and evening. The greatest severe threat could materialize over the
mid Mississippi and lower Ohio Valley on Tuesday, and in the
Northeast on Wednesday, adjacent to a mid-level jet passing through.
However, uncertainty is substantial at this time concerning the
timing of the upper-level trough and cold front.

..Broyles.. 05/13/2026

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ACUS48 KWNS 140903
SWOD48
SPC AC 140901

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0401 AM CDT Thu May 14 2026

Valid 171200Z - 221200Z

...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/SUN...D5/MON...

...DISCUSSION...
...Sunday/Day 4 and Monday/Day 5...
An upper-level trough is forecast to move eastward across the
Intermountain West on Sunday, as a subtle shortwave trough moves
northeastward across the Great Plains. Ahead of the trough a moist
and unstable airmass is forecast across much of the Great Plains
eastward into the Mississippi Valley. Scattered elevated strong
thunderstorms will be possible early in the day from the northern
Plains eastward into the upper Mississippi Valley. Southward into
the central Plains and mid Missouri Valley, strong surface heating
is forecast. Some models suggest MLCAPE could peak in the 3000 to
4000 J/kg range. In addition, a broad 40 to 50 knot low-level jet is
forecast to strengthen late Sunday afternoon. This, combined with
moderate to strong deep-layer shear over much of the moist sector
will be favorable for severe storms potentially over a large area. A
severe weather outbreak will be possible from the afternoon and
evening into the early overnight period. The setup appears favorable
for supercells with tornadoes, large to very large hail and wind
damage.

On Monday, model forecasts eject a negatively-tilted upper-level
trough into the central Plains. Ahead of the trough, a moist and
unstable airmass is forecast to be located from the southern and
central Plains northeastward into the Upper Midwest. A mid-level jet
is forecast to also eject northeastward across the central Plains as
a broad low-level jet strengthens during the late afternoon.
Thunderstorm development is expected along the western edge of the
airmass near a dryline over west-central Kansas and southeast
Nebraska. Thunderstorms that move into the strong low-level flow in
the late afternoon and early evening will have potential to be
supercells with large to very large hail, and tornadoes. Severe wind
gusts will also be possible. A severe weather outbreak will be
possible from Monday afternoon into evening and overnight period.

...Tuesday/Day 6 to Thursday/Day 8...
On Tuesday, mid-level southwesterly flow is forecast over the
central U.S., with a cold front moving southeastward through the
central Plains and Upper Midwest. Ahead of this front, surface
dewpoints from the mid 60s to the lower 70s F are expected to
contribute to moderate to strong instability. Thunderstorm
development with a severe threat will be possible along and ahead of
the front during the afternoon and evening from the northern part of
the southern Plains northeastward into the mid Mississippi Valley.

On Wednesday and Thursday, the cold front is forecast to move slowly southeastward across the southern Plains and mid Mississippi Valley,
extending east-northeastward into the Mid-Atlantic. A severe threat
could develop along and ahead of the front each afternoon and
evening. However, uncertainty concerning the exact location of the
front is substantial at this extended range.

..Broyles.. 05/14/2026

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ACUS48 KWNS 150903
SWOD48
SPC AC 150901

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0401 AM CDT Fri May 15 2026

Valid 181200Z - 231200Z

...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/MON...

...DISCUSSION...
...Monday/Day 4...
A severe weather outbreak will be possible from Monday afternoon
into the evening and overnight period. On Monday, the western trough
will take on a negative tilt before ejecting across the central
Plains, with strong southwesterly flow aloft overspreading the
region. This will result in strong lee cyclone development across
western Kansas. A surface cold front will extend northward to a
secondary surface low across the upper Midwest. A dryline will
extend southward across portions of western Kansas into western
Oklahoma. Numerous thunderstorms are expected to develop along and
ahead of the cold front and further south along the dryline Monday
afternoon and evening from Nebraska into central Kansas. Given the
volatile air mass ahead of these features, with moderate to strong
instability and strengthening deep layer shear, initial development
will likely be supercellular. Initial supercells will pose risk of
all hazards including large to very large hail, damaging wind, and
tornadoes. As the southwesterly low-level jet increases into the
evening, large clockwise enhancement of low-level hodographs across
portions of central Kansas into northern Oklahoma may lead to an
increasing risk for strong to intense tornadoes. Additional
thunderstorm development will spread in tandem with the cold front
from the central Plains to the upper Midwest through the evening,
with potential for more widespread damaging wind and a few tornadoes
(some of which may be strong).

...Tuesday/Day 5 to Thursday/Day 7...
Severe potential is expected to continue D5/Tuesday as the cold
front extends from the upper Midwest to southern Plains. Strong to
moderate instability ahead of the front will continue to support
severe storms from the northern part of the southern Plains
northeastward into the mid Mississippi Valley. Trends are for the
front to shift eastward faster than originally expected, and as such probabilities were shifted eastward with this update. Strong to
severe storms may extend further north into the northeast and Great
Lakes Region.

On Wednesday and Thursday, the cold front is forecast to move
southeastward across the southern Plains and mid Mississippi Valley,
extending east-northeastward into the Mid-Atlantic. A severe threat
could develop along and ahead of the front each afternoon and
evening. However, uncertainty concerning the exact location of the
front is substantial at this extended range.

..Thornton.. 05/15/2026

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