ACUS48 KWNS 210852
SWOD48
SPC AC 210850

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0350 AM CDT Wed May 21 2025

Valid 241200Z - 291200Z

...DISCUSSION...
Severe weather is possible across portions of the central Plains on
Saturday and Sunday as a mid-level trough emerges from the Rockies
into the Plains. Upper 60s to low 70s dewpoints will result in
strong to very strong instability south of a frontal zone. This
front will initially be stationary across Kansas on Saturday before
starting to advance south Saturday night and Sunday. Given the
instability ahead of this front, widespread storm development is
likely. However, the severity of this convection remains
questionable. The operational GFS is the most aggressive with severe
weather potential as it maintains troughing into the Plains with
southwesterly flow around 40 knots forecast across the frontal zone
which should provide ample shear for severe storms given the likely
instability that will be in place. However, this appears to be an
outlier with weaker, more zonal flow preferred by the ECMWF and the
ECS and GEFS. Due to this uncertainty regarding the mid-level
troughing and shear across the warm sector, severe weather
probabilities are not warranted at this time.

High pressure will build into much of the eastern CONUS on Day
6/Monday and persist for much of the week. This will shunt a frontal
zone and the better moisture closer to the Gulf coast, removed from
the stronger mid-level westerlies. Therefore, thunderstorms will be
likely along this frontal zone through the week, but organized
severe storms are not expected to be that widespread.

..Bentley.. 05/21/2025

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ACUS48 KWNS 220904
SWOD48
SPC AC 220903

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0403 AM CDT Thu May 22 2025

Valid 251200Z - 301200Z

...DISCUSSION...
Severe storms are possible across parts of the central/southern High
Plains on D4/Sunday as ridging shifts east and broad southwesterly
flow overspreads the southern High Plains. Moderate to strong
instability is forecast with modest height falls and forecast
soundings show an uncapped airmass. Scattered to widespread
thunderstorms are likely across much of the warm sector across
central Oklahoma and northwest Texas. Details of storm mode and
hazard type remain nebulous at this time. However, a focused zone of
the most likely threat area exists across northwest Texas and
southwest Oklahoma where 15% probabilities have been introduced.

Beyond Day 4, some isolated strong to severe storms will be possible
along a stalled front from the Southeast to Far West Texas.
Mid-level shortwave troughs embedded within mostly zonal flow along
this frontal zone may focus some severe weather, but significant
uncertainty exists regarding the timing and amplitude of any of
these shortwave troughs. A few damaging wind gusts will be possible
from this activity, but a more widespread threat is not anticipated.

..Bentley.. 05/22/2025

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ACUS48 KWNS 230901
SWOD48
SPC AC 230900

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Fri May 23 2025

Valid 261200Z - 311200Z

...DISCUSSION...
...Monday/Day 4 to Wednesday/Day 6...
The medium-range models move a mid-level trough into the southern
and central Plains on Monday. Ahead of the trough, a moist airmass
is forecast from the southern Plains into the Gulf Coast states.
Scattered thunderstorms are expected across much of this airmass
Monday afternoon. The greatest convective coverage should be located
in parts of central and east Texas, where warm advection is forecast
to be maximized. Across the moist airmass, moderate instability will
likely be in place by midday. In addition, westerly flow associated
with the trough, should be strong enough for a severe threat. Large
hail and severe gusts will be possible as a cluster or line of
storms moves southeastward into central and east Texas during the
afternoon and evening.

On Tuesday, the moist airmass is forecast to remain in place from
the southern Plains eastward into the Gulf Coast states, with the
mid-level trough moving into the Ozarks. Model forecasts suggest
that numerous thunderstorms will develop ahead of the trough in
parts of the Southeast, with more isolated development occurring
across the southern Plains. Although a severe threat will be
possible across parts of this airmass, mesoscale processes will
determine the most favorable areas for severe. It appears that
instability will support isolated wind damage and hail, but
predictability appears low concerning the spatial distribution of
any isolated threat.

On Wednesday, the most unstable air is forecast from parts of
central and south Texas eastward into the lower Mississippi Valley.
Although large-scale ascent is forecast to be weak, thunderstorms
should develop in areas that warm up sufficiently along residual
outflow boundaries. An isolated severe threat should develop during
the mid to late afternoon, but predictability appears to be low.

...Thursday/Day 7 and Friday/Day 8...
On Thursday and Friday, westerly mid-level flow is forecast over the
southern U.S., where an unstable airmass is expected to remain in
place. As surface temperatures warm each day, isolated to scattered thunderstorm development should take place. Although instability and
shear will be favorable for severe storms in a few areas,
predictability remains low.

In addition, on Friday convection will be possible ahead of a cold
front across parts of the Atlantic Seaboard. Enough instability
should be in place during the day for an isolated severe threat.
However, the spatial distribution of any potential threat appears to
have low predictability.

..Broyles.. 05/23/2025

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ACUS48 KWNS 240853
SWOD48
SPC AC 240852

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0352 AM CDT Sat May 24 2025

Valid 271200Z - 011200Z

...DISCUSSION...
...Tuesday/Day 4 and Wednesday/Day 5...
A mid-level trough is forecast to move eastward from the southern
and central Plains into the Southeast on Tuesday and Wednesday. A
moist and unstable airmass is forecast to be in place on both days
from the Texas Hill Country eastward into the central Gulf Coast
states. During the day on Tuesday and Wednesday, deep-layer shear
across this airmass is forecast to be marginal for organized severe thunderstorms. However, an isolated severe threat will be possible
in areas that strongly destabilize. Steep low-level lapse rates
could support severe gusts with storm-scale line segments that form
from afternoon into the overnight period.

Further west into the southern and central High Plains, an axis of
moderate instability is forecast to develop Wednesday afternoon from
eastern New Mexico into southeastern Colorado. Thunderstorms that
move off the higher terrain could develop an isolated severe threat.

...Thursday/Day 6 to Saturday/Day 8...
A mid-level shortwave trough is forecast to move into the Ark-La-Tex
on Thursday. Scattered thunderstorm will be possible near and ahead
of the trough during the day from central and north Texas
southeastward into the lower Mississippi Valley. If a storm-scale
convective system can become organized, then a swath of wind damage
will be possible. However, predictability remains low concerning
this potential.

On Friday and Saturday, a strong cold front is forecast to move
southward through the Gulf Coast states and into the Gulf of
America. Behind the front, a relatively dry air mass over much of
the central and eastern U.S. is expected to limit severe
thunderstorm potential.

..Broyles.. 05/24/2025

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ACUS48 KWNS 250854
SWOD48
SPC AC 250853

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0353 AM CDT Sun May 25 2025

Valid 281200Z - 021200Z

...DISCUSSION...
...Wednesday/Day 4 and Thursday/Day 5...
A mid-level low is forecast to move eastward into the upper
Mississippi Valley on Wednesday, as a cold front advances
southeastward across the southern and eastern U.S. Thunderstorm
development is expected to take place along and near the front
during the day as surface temperatures warm. An isolated severe
threat will be possible Wednesday afternoon and evening, mainly
across parts of the Southeast and southern Plains, where some areas
could moderately destabilize. Mid-level flow is forecast to be
somewhat weak, should could marginalize the severe threat in most
areas.

On Thursday, the mid-level low is forecast to move eastward across
the Great Lakes, as the previously mentioned front moves slowly
southeastward. The tail end of the front is forecast to be in the
southern Plains, where scattered thunderstorms should develop
Thursday afternoon. Over the southern Plains, northwest mid-level
flow is forecast to create enough deep-layer shear for isolated
severe storms. However, predictability is too low to delineate any
areas with a potentially greater risk.

...Friday/Day 6 to Sunday/Day 8...
From Friday to Sunday, a mid-level trough in the lower Great Lakes
is forecast to move into the western Atlantic, as another trough
develops in its wake, over the eastern U.S. Behind this trough,
northwest mid-level flow will remain in place across much of the
central and eastern U.S. In response, a relatively dry airmass is
forecast remain in place across much of the central and eastern U.S.
For this reason, the potential for strong thunderstorm development
is expected to remain isolated in most areas over the weekend.

..Broyles.. 05/25/2025

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ACUS48 KWNS 260859
SWOD48
SPC AC 260858

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0358 AM CDT Mon May 26 2025

Valid 291200Z - 031200Z

...DISCUSSION...
...Thursday/Day 4 to Saturday/Day 6...
A mid-level trough will move eastward into the eastern U.S. on
Thursday, as a front remains over the Gulf Coast states and southern
Plains. Thunderstorm development will be possible near and to the
south of the front Thursday afternoon, with the greatest convective
coverage expected over parts of east Texas and the lower Mississippi
Valley. An isolated severe threat will be possible during the day on
Thursday as surface heating takes place. Any severe threat should be concentrated in areas where low-level convergence becomes maximized
near the front. At this time, confidence concerning a more focused
severe threat area is low.

On Friday, the front is forecast to move southward across the
southern Plains and Gulf Coast states. Moderate instability is
forecast to the south of the front across parts of south-central and
southwest Texas, and across parts of Florida. Isolated to scattered thunderstorms may develop in these areas, with a marginal severe
threat possible.

On Saturday, northerly flow at mid-levels is forecast to develop
over the Great Plains. In response, some models suggest surface high
pressure will be dominant across the Great Plains. This would limit
severe potential. However, other model solutions suggest that some
low-level moisture could return northward into the southern Plains.
If this occurs, isolated to scattered thunderstorms that develop in
the afternoon could have a marginal severe threat. Predictability is
low concerning any specific scenario.

...Sunday/Day 7 and Monday/Day 8...
Northerly flow at mid-levels is forecast to remain over the Great
Plains on Sunday, as a trough moves east-southeastward across the
Gulf of America. At the surface, a large area of high pressure is
forecast over the central and eastern U.S. Although isolated to
scattered thunderstorms could form Sunday afternoon over parts of
the Great Plains and Mississippi Valley, any severe threat is
expected to be isolated. This same setup is forecast to continue
into Monday.

Further northwest into parts of the northern High Plains on Monday,
model forecasts suggest a trough could move through the northern
Rockies and approach the northern High Plains. An axis of moderate
instability is forecast to develop by afternoon across parts of
western South Dakota and eastern Montana, where a severe threat
would be possible. However, predictability at this range is low.

..Broyles.. 05/26/2025

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ACUS48 KWNS 270859
SWOD48
SPC AC 270858

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0358 AM CDT Tue May 27 2025

Valid 301200Z - 041200Z

...DISCUSSION...
...Friday/Day 4 to Sunday/Day 6...
On Friday, a mid-level trough is forecast to move eastward from the
mid Mississippi Valley into the eastern U.S. At the surface, a moist
airmass is forecast to be located from the Gulf Coast states
northeastward into the Carolinas, where moderate instability should
be in place by afternoon. Ahead of the trough, large-scale ascent
should support scattered thunderstorm development, with the greatest
convective coverage expected from Georgia northeastward into the
Carolinas. Model forecasts suggest that moderate deep-layer shear
will exist ahead of the trough, which will contribute to a
possibility for severe storms from mid afternoon into the early
evening. Large hail and wind damage would be the primary threats.

On Saturday and Sunday, a cold front is forecast to move southward
across the Gulf of America, as northwesterly mid-level flow develops
over the central U.S. A shortwave trough is forecast to move
southeastward from the central Plains on Saturday into the lower
Mississippi Valley on Sunday. Scattered thunderstorms should develop
ahead of a shortwave trough each afternoon and evening. An isolated
severe threat will be possible. However, the combination of
instability and deep-layer shear is not expected to be sufficient
for a greater severe threat.

...Monday/Day 7 and Tuesday/ Day 8...
A pronounced mid-level ridge is forecast to develop on Monday across
the central U.S., with the ridge moving eastward into the Great
Lakes on Tuesday. In the wake of the ridge, strong to severe
thunderstorm development will be possible over parts of the northern
Plains Monday afternoon and evening. On Tuesday, model forecasts
suggest that scattered thunderstorm development could take place
ahead of the trough in the upper Mississippi Valley, with additional
storm development over the lower to mid Missouri Valley. Although a
severe threat may develop, predictability for early next week is low
at this time.

..Broyles.. 05/27/2025

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ACUS48 KWNS 280901
SWOD48
SPC AC 280900

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Wed May 28 2025

Valid 311200Z - 051200Z

...DISCUSSION...
...Saturday/Day 4 and Sunday/Day 5...
From Saturday into Sunday, a mid-level shortwave trough is forecast
to move from the central Plains into the Southeast. Instability is
not forecast be particularly strong head of the trough. However,
large-scale ascent will support scattered thunderstorm development
on Saturday in parts of the central Plains and Ozarks, and on Sunday
from east Texas into the lower Mississippi Valley. Deep-layer shear
should be adequate for isolated severe thunderstorm development. The
threat is expected to be marginal.

...Monday/Day 6 to Wednesday/Day 8...
During the early week period, a mid-level ridge is forecast to move
across the central U.S., as a shortwave trough moves through the
Desert Southwest. Ahead of this feature, low-level moisture will
increase across the Great Plains, as low-level flow strengthens in
the wake of the ridge. Surface dewpoints are expected to increase
into the 60s F across much of the Great Plains, which should allow
for moderate to strong destabilization in some areas during the
afternoon. Although large-scale ascent will generally be weak across
most of the Great Plains, thunderstorm development will be possible
Monday afternoon over parts of the High Plains. An isolated severe
threat could develop late Monday afternoon into the evening along
the western edge of the stronger instability from eastern New
Mexico, northward into western South Dakota.

During the mid week, the shortwave trough is forecast to move across
the central U.S. on Tuesday and into the Great Lakes on Wednesday.
Thunderstorm development is expected across an unstable airmass,
which is forecast to be located in the Great Plains. Forecast
instability and deep-layer shear suggest a severe threat will be
possible in areas that have sufficient large-scale forcing, although
confidence is low concerning any potential scenario. If model runs
maintain consistency and show more agreement among solutions over
the next couple of runs, a 15 percent area may be needed in parts of
the Great Plains during the early to mid week.

..Broyles.. 05/28/2025

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ACUS48 KWNS 290812
SWOD48
SPC AC 290811

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0311 AM CDT Thu May 29 2025

Valid 011200Z - 061200Z

...DISCUSSION...
...Sunday/Day 4 and Monday/Day 5...
On Sunday and Monday, a mid-level ridge is forecast to move eastward
across the north-central U.S. A low-level jet is forecast to develop
in the High Plains on Sunday with this feature strengthening on
Monday, as a trough moves through the Rockies. In response,
low-level moisture will increase across the Great Plains, allowing
for moderate destabilization across much of the region during the
day. Scattered thunderstorm development is expected Monday from
parts of the southern and central High Plains, northeastward along a
cold front into the Dakotas. Although deep-layer shear is not
forecast to be particular strong, the models do suggest that strong
instability will be possible across parts of the Dakotas by late
Monday afternoon. This likely would support a large hail and
wind-damage threat.

...Tuesday/Day 6 to Thursday/Day 8...
On Tuesday, the shortwave mid-level trough is forecast to move
eastward into the southern and central High Plains. Scattered
thunderstorms are expected Tuesday afternoon from the mid Missouri
Valley southward into eastern Kansas and east-central Oklahoma. In
addition to moderate/strong instability, large-scale ascent and
moderate deep-layer shear should support a severe threat during the
afternoon and evening. Supercells would be possible, with isolated
large hail and wind damage. Tornadoes could also occur.

On Wednesday, the cold front is forecast to move southeastward into
the mid Mississippi Valley, and southward into the southern Plains.
Mid-level flow near the front will be southwesterly. Ahead of the
front, surface dewpoints should be from the 60s to the mid 70s F,
which will contribute to moderate instability by afternoon. Although
deep-layer shear is not expected to be that strong near the front,
the instability should be enough for isolated severe storms in areas
where strong surface heating occurs. Predictability is low
concerning where the greater severe threat will be.

On Thursday, the front is forecast to move into the Southeast.
Thunderstorm development will be possible by afternoon along and
ahead of the front, from the Texas Coastal Plain northeastward into
the Gulf Coast states. Although moderate instability should be in
place in some areas by afternoon, deep-layer shear is forecast to be
weak enough to keep any severe threat localized.

..Broyles.. 05/29/2025

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ACUS48 KWNS 300901
SWOD48
SPC AC 300859

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0359 AM CDT Fri May 30 2025

Valid 021200Z - 071200Z

...DISCUSSION...
As mentioned in WPC's Extended Forecast Discussion, an amplified
split-flow pattern across the CONUS renders below-average
predictability through the period. Will maintain inherited
severe-weather areas for D4-5, with mesoscale severe potential
evident in D6 and beyond but with poor synoptic predictability.

...D4/Monday...
A positive-tilt mid/upper trough should shift east as an embedded
shortwave impulse over the northern Rockies tracks near the
international border over the northern Great Plains. A northeast/southwest-oriented cold front should accelerate southward
into the central High Plains while a weak frontal wave temporarily
stalls the front over the Red River Valley of the North. There are
pronounced signals for afternoon to evening convection along the
front. Initially steep mid-level lapse rates will be supportive of
scattered severe potential. But it appears that stronger mid-level
flow may lag to the cool side of the front, which may limit a
greater threat.

...D5/Tuesday...
Complex severe potential is expected across the central states.
Low-amplitude shortwave impulses should be progressing across parts
of the northern Upper Midwest to the central High Plains on Tuesday
morning. Some guidance suggests extensive overnight convection may
be ongoing within a favorably diffluent upper-flow regime,
characterized by a coupled southern-stream left-exit and
northern-stream right-entrance regime. This renders substantial
uncertainty on where more robust boundary-layer destabilization
should occur. Warm mid-level temperatures in the southern stream
should yield modest mid-level lapse rates, which further lowers
confidence. Nevertheless, a broad and rich moist sector and adequate
deep-layer shear, along with widespread convection during the afternoon/evening, indicate scattered severe storms remain possible.

..Grams.. 05/30/2025

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ACUS48 KWNS 310856
SWOD48
SPC AC 310854

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0354 AM CDT Sat May 31 2025

Valid 031200Z - 081200Z

...DISCUSSION...
Somewhat greater confidence exists for a more south-southwest to north-northeast oriented swath of severe on D4/Tuesday. This appears
focused from the southern Great Plains to the Midwest from midday
into early evening. Overall pattern appears less amplified after D4,
with nebulous severe potential in the central to eastern states.

...D4/Tuesday...
A low-amplitude southern-stream shortwave impulse may phase with a northern-stream shortwave trough in the Upper Great Lakes vicinity
by late Tuesday. The accompanying surface wave over KS may similarly
track northeastward along a cold front through the Upper Midwest.
Rich low-level moisture will become more prevalent ahead of the
front and should spread into at least WI. Extensive convection may
be ongoing at 12Z within an increasingly favorable diffluent
upper-flow regime that is coupled with a broad low-level jet. Amid
relatively warm 500-mb temperatures within the southwest flow regime
attendant to the southern-stream impulse, mid-level lapse rates will
likely be weak in the warm-moist sector. Where appreciable
boundary-layer heating can occur ahead of morning convection,
scattered severe storms are possible.

...D5-8/Wednesday-Saturday...
Weak mid-level lapse rates will be pervasive, suggesting that robust
diurnal heating will largely drive daily bouts of seemingly
lower-probability severe. Guidance consensus suggests a more zonal
mid-level flow regime may evolve towards D7/Friday, which would aid
in the development/expansion of the elevated mixed layer and a
return of steep mid-level lapse rates across the High Plains.

..Grams.. 05/31/2025

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ACUS48 KWNS 010832
SWOD48
SPC AC 010830

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0330 AM CDT Sun Jun 01 2025

Valid 041200Z - 091200Z

...DISCUSSION...
Enhanced mid-level southwesterlies initially present over the
central Great Lakes early Wednesday should become confined to ON/QC
as a lower-amplitude shortwave trough dampens. Trailing to the south
of this, low-probability severe is apparent on Wednesday afternoon
in the eastern Midwest, and on Thursday afternoon over the Northeast along/ahead of a decaying cold front.

Another southern-stream shortwave impulse is progged to move east
from the Southwest mid-week. But initial surface ridging downstream
over the southern High Plains suggests the potential severe area
will be limited. Greater potential may await D6-7/Friday-Saturday,
as the ridging breaks down and zonal mid-level flow returns in the
wake of the aforementioned impulse. This will yield strengthening
and expansion of the EML east of the CO Plateau. ML guidance from
both the latest 00Z SPC/NSSL GEFS and yesterday's 00Z NCAR ECENS
highlight 15 percent probabilities on D6-7/Friday-Saturday across
the TX Panhandle into western KS/OK. Potential MCVs embedded within
this regime appear too minor at this time frame to reliably
delineate an area, but bear watching for shorter-term outlooks.

..Grams.. 06/01/2025

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ACUS48 KWNS 020841
SWOD48
SPC AC 020839

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0339 AM CDT Mon Jun 02 2025

Valid 051200Z - 101200Z

...DISCUSSION...
Latest guidance has trended towards a climatologically active
extended period for severe potential. It appears that 15 percent
severe areas will likely be delineated each day within a persistent
split-flow regime. Belts of enhanced mid-level westerlies should
accompany the train of low-amplitude southern-stream shortwave
impulses. Meanwhile, above-average agreement exists with the
amplification of a large-scale trough into the north-central states
towards the end of the period. This would suppress the southern
stream southward in the southern Great Plains to Deep South.

Reliably timing individual low-amplitude impulses/MCVs can be
difficult in this setup. But it appears that the initial impulse
ejecting across the southern Rockies around 12Z Thursday should
serve to focus severe potential from the TX Panhandle into southern
KS on D4. This feature may continue eastward towards the Mid-MS
Valley/eastern Midwest on D5/Friday. But with probable weak
mid-level lapse rates downstream and lack of run-to-run continuity
across guidance, will defer on a 15 percent area highlight.

..Grams.. 06/02/2025

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ACUS48 KWNS 030852
SWOD48
SPC AC 030851

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0351 AM CDT Tue Jun 03 2025

Valid 061200Z - 111200Z

...DISCUSSION...
An active severe-weather pattern for repeated MCS development is
anticipated through this weekend, with more nebulous potential early
next week.

Medium-range guidance has converged to above-average consistency
with the large-scale pattern through this weekend. Enhanced zonal
mid-level flow within the southern stream should overlie a
seasonably rich and unstable air mass across the southern Great
Plains to the Deep South. Initial signal for south-central High
Plains nocturnal MCS development spreading east-southeast onto the
lower plains is evident late D3 and this will probably repeat on
D4/Friday night and perhaps on D5/Saturday night. This should
subside as a northern-stream upper trough amplifies into the
north-central states.

Remnant MCVs should focus downstream diurnal thunderstorm
development each afternoon through at least D6/Sunday. Given the
buoyancy/shear parameter space, sufficient confidence exists for
highlighting a scattered severe-storm threat on D4-5. Damaging winds
appear to be the dominant hazard in this pattern. An additional area
on D6 is plausible in later outlooks somewhere in the Deep South and
Gulf Coast States. For D7-8, severe potential is nebulous, but may
be tied to the evolution of the north-central states trough.

..Grams.. 06/03/2025

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ACUS48 KWNS 030919
SWOD48
SPC AC 030918

Day 4-8 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0418 AM CDT Tue Jun 03 2025

Valid 061200Z - 111200Z

CORRECTED FOR MISSING LABEL ON DAY 6

...DISCUSSION...
An active severe-weather pattern for repeated MCS development is
anticipated through this weekend, with more nebulous potential early
next week.

Medium-range guidance has converged to above-average consistency
with the large-scale pattern through this weekend. Enhanced zonal
mid-level flow within the southern stream should overlie a
seasonably rich and unstable air mass across the southern Great
Plains to the Deep South. Initial signal for south-central High
Plains nocturnal MCS development spreading east-southeast onto the
lower plains is evident late D3 and this will probably repeat on
D4/Friday night and perhaps on D5/Saturday night. This should
subside as a northern-stream upper trough amplifies into the
north-central states.

Remnant MCVs should focus downstream diurnal thunderstorm
development each afternoon through at least D6/Sunday. Given the
buoyancy/shear parameter space, sufficient confidence exists for
highlighting a scattered severe-storm threat on D4-5. Damaging winds
appear to be the dominant hazard in this pattern. An additional area
on D6 is plausible in later outlooks somewhere in the Deep South and
Gulf Coast States. For D7-8, severe potential is nebulous, but may
be tied to the evolution of the north-central states trough.

..Grams.. 06/03/2025

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ACUS48 KWNS 040853
SWOD48
SPC AC 040851

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0351 AM CDT Wed Jun 04 2025

Valid 071200Z - 121200Z

...DISCUSSION...
Another active day characterized by an ongoing MCS and remnant
downstream MCVs is anticipated on D4/Saturday, with a broad belt of
mainly damaging wind potential evident. Seasonably strong mid-level
westerlies are expected to remain coincident with rich low-level
moisture. Ample buoyancy should diurnally develop south of
pre-existing outflows. This multi-day pattern finally breaks down
into D5/Sunday with amplification of a large-scale trough from the
southern Prairie Provinces into the Upper Midwest. Mesoscale-focused
severe potential may linger into at least D5/Sunday over the
southern High Plains to the TX/OK Red River Valley and from the
central Gulf to south Atlantic Coasts.

Otherwise, low-probability severe potential could begin in a portion
of the northern Great Plains on D4/Saturday, in association with the
amplifying trough. This should subsequently shift eastward and
likely broaden across the Great Lakes into the Northeast through
early next week. Overall instability appears modest until a
potential increase later when stronger flow fields overlap richer
low-level moisture. Daily severe probabilities appear to be sub-15
percent at this range, with a relative maximum in the
D6-7/Monday-Tuesday timeframe over the Northeast. Current timing of
this trough exiting New England by around D8/Wednesday suggests a
relative minimum across the CONUS then.

..Grams.. 06/04/2025

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ACUS48 KWNS 050858
SWOD48
SPC AC 050856

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0356 AM CDT Thu Jun 05 2025

Valid 081200Z - 131200Z

...DISCUSSION...
The active severe-weather pattern from the southern High Plains to
the Southeast should persist into D4/Sunday. A low-amplitude
mid-level trough is progged across the Southeast with a belt of
enhanced westerlies. The degree of ongoing convection on Sunday
morning lowers confidence on how broad a region of scattered
severe-storm potential exists in the Southeast. The best area for less-impactful morning convection appears to be across the South
Atlantic Coastal Plain and adjacent eastern Piedmont. Scattered
damaging winds should be the main hazard from afternoon storms in
this region.

With a brief respite in the wake of multiple MCSs on D1 to early D3,
buoyancy should become large to locally extreme across a portion of
the southern High Plains to OK/TX Red River Valley by Sunday
afternoon. Latest guidance is quite insistent on more widespread
convective development during the late afternoon into Sunday night,
along the persistent quasi-stationary front. Although
mid/upper-level winds may be weaker relative to prior days, an
increased west-northwesterly component along with the very unstable
airmass will support severe hail/wind, which could be significant.

Guidance has shown less predictability in the D5-6/Monday-Tuesday
time frame. This seems related to handling of downstream MCV
evolution from the probable Sunday night MCS over OK/TX, as well as
individual shortwave impulses embedded within the broad upper trough
over the Upper Midwest to Great Lakes. Expansive swaths of
low-probability severe are evident across the southern to eastern
states but predictability is too low for any 15 percent highlights.
By mid-week, guidance is still signaling a reduction in overall
severe potential with a synoptic pattern change to predominantly
weak shear coincident with areas of moderate to large buoyancy.

..Grams.. 06/05/2025

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ACUS48 KWNS 060853
SWOD48
SPC AC 060852

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0352 AM CDT Fri Jun 06 2025

Valid 091200Z - 141200Z

...DISCUSSION...
A large MCS may be ongoing across the Ark-La-Tex vicinity on
D4/Monday morning. This MCS and attendant flow enhancement with its
MCV may support scattered damaging wind potential into the afternoon
downstream across the Deep South. How extensive an organized wind
threat persists is quite nebulous, given background mid-level
westerlies being weaker across the Southeast compared to prior days.

Sub-15 percent severe potential remains apparent across the Upper OH
Valley to Lower Great Lakes on D4/Monday, shifting east into the Northeast/Mid-Atlantic States on D5/Tuesday. A belt of strong
mid-level southwesterlies ahead of broad Great Lakes trough should
overlap parts of a weak cold front arcing south from a primary
surface cyclone over northeast ON to James Bay. Substantial
instability ahead of the front appears uncertain with progged weak
mid-level lapse rates and muted boundary-layer heating where the
stronger flow resides.

During D6-8/Wednesday-Friday, guidance continues to signal a
reduction in severe potential, as predominantly weak deep-layer
shear overlaps areas of moderate to large buoyancy.

..Grams.. 06/06/2025

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ACUS48 KWNS 070842
SWOD48
SPC AC 070841

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0341 AM CDT Sat Jun 07 2025

Valid 101200Z - 151200Z

...DISCUSSION...
Sub-15 percent severe potential remains apparent over the Mid-Atlantic/Northeast States on D4/Tuesday before a cold front
moves offshore. Instability progs remain weak where at least
moderate deep-layer shear is anticipated. It seems plausible that
the northern extent of larger buoyancy will be suppressed south in
the wake of extensive convection through D3 across the Southeast.

On D5-6/Wednesday-Thursday, guidance has trended towards some
amplification of a minor southern-stream shortwave impulse as it
drifts across the southern Great Plains. This could foster mesoscale
corridors of modest shear overlapping plentiful buoyancy in the
south-central states.

Western Gulf moisture will spread north and encompass much of the
central states through next weekend. Various shortwave impulses over
the Northwest may support multiple bouts of mesoscale-driven severe
potential along the northern periphery of the expansive Great Plains
buoyancy plume.

..Grams.. 06/07/2025

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