RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Thu Jul 9 09:03:01 UTC 2026.
No Mesoscale Discussions are in effect as of Thu Jul 9 09:03:01 UTC 2026.
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1255 AM CDT Thu Jul 09 2026
Valid 091200Z - 101200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL AND NORTHERN PLAINS...AND FROM THE OZARKS INTO THE LOWER
OHIO VALLEY...
...SUMMARY...
Thunderstorms with severe wind gusts and hail will be possible this
afternoon and evening across parts of the central and northern
Plains. Severe wind gusts may also occur in parts of the Ozarks, mid
Mississippi Valley, lower Ohio Valley, Mid-Atlantic and Arizona.
...Central and Northern Plains...
A mid-level shortwave trough will move through the central and
northern Plains today. Ahead of the trough, a moist and unstable
airmass will be in place from the Dakotas southward into Nebraska,
where surface dewpoints will mostly be in the 60s F. As surface
temperatures warm, moderate instability will develop across much of
the region. Along and near the instability axis, MLCAPE is forecast
to increase into the 2500 to 3500 J/kg range. As instability peaks
late this afternoon, low-level convergence will likely become
maximized along a surface trough from the western Dakotas southward
into eastern Colorado. This will aid convective initiation, with
several clusters developing and moving eastward across the central
and northern High Plains. In the vicinity of the instability axis,
moderate deep-layer shear and steep mid-level lapse rate will
support a threat for severe wind gusts and isolated large hail.
Hailstones of greater than 2 inches in diameter will be possible
across parts of central and northern North Dakota where instability
and deep-layer shear will be favorable for supercells.
Further south into parts of western and central Kansas, an
east-to-west axis of low-level moisture will be in place. Some model
forecasts suggest that an organized line of storms will develop and
move eastward along this axis during the early to mid evening.
Severe wind gusts will be possible with this line of storms.
...Ozarks/Mid Mississippi and Lower Ohio Valley...
A very moist airmass will be in place today from the Ozarks eastward
into the lower Ohio Valley, where surface dewpoints will be in the
mid to upper 70s F. In response to surface heating, moderate to
strong instability is expected to develop by afternoon across parts
of the mid Mississippi Valley. Some model solutions have an axis of
low-level convergence located from central Missouri eastward to
southern Indiana, suggesting that convective coverage could be
maximized along this corridor. The instability, along with steep low
to mid-level lapse rates will be favorable for severe wind gusts
with any line segment that can become organized.
...Mid-Atlantic...
A mid-level shortwave trough will move through the southern
Appalachians today and approach the Mid-Atlantic. Ahead of this
feature, a moist and unstable airmass will be in place with surface
dewpoints in the mid to upper 70s F. This will contribute to a
pocket of moderate to strong instability by afternoon. Thunderstorms
that develop in the higher terrain of the central Appalachians will
move eastward into the Mid-Atlantic during the late afternoon and
early evening. Forecast deep-layer shear appears sufficient to
support a severe threat. The instability and steep low-level lapse
rates will contribute to a potential for severe wind gusts with the
stronger multicells.
...Southeast Arizona...
An axis of instability is forecast to develop today across southeast
Arizona. Near this axis, low-level convergence will become maximized
during the afternoon, which will result in isolated to scattered
convective initiation. Storms that form near the instability axis as
low-level lapse rates peak in the late afternoon could produce
isolated severe wind gusts.
..Broyles/Moore.. 07/09/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1156 PM CDT Wed Jul 08 2026
Valid 101200Z - 111200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY INTO
FRIDAY NIGHT ACROSS PARTS OF THE SOUTHERN ROCKIES INTO ADJACENT
CENTRAL GREAT PLAINS AND ACROSS PARTS OF THE LOWER MISSOURI VALLEY
AND OZARK PLATEAU INTO THE TENNESSEE VALLEY...
...SUMMARY...
Clusters of thunderstorms, accompanied by a risk for damaging wind
gusts and some hail, may evolve in a corridor across parts of the
south central Great Plains into the Tennessee Valley Friday
afternoon and evening.
...Discussion...
Latest model output indicates little general change from prior runs.
To the southeast of a vigorous short wave trough digging offshore of
the southern British Columbia coast, it appears that an increasingly
prominent mid/upper-level high will begin to form across portions of
the Colorado Valley/Plateau through southern Rockies vicinity late
Friday through Friday night. Ridging to the north of the high is
also forecast to continue building along an axis across the northern
U.S. Great Plains into eastern Canadian Prairies, while downstream
positively tilted larger-scale troughing gradually shifts into and
across the northern Atlantic Seaboard.
The evolution of remnant weak troughing across the central Great
Plains into lower Missouri Valley remains much more unclear, based
on continuing varied model solutions However, a belt of westerlies
to its south may remain convectively augmented in lower/mid-levels,
though perhaps weaker than Thursday.
The potential for at least moderate destabilization remains most
certain along the southern periphery of this regime, aided by a
corridor of steeper lower through mid-tropospheric lapse rates
associated with elevated mixed-layer air (probably based closer to
850 mb than 700 mb), above a seasonably moist boundary-layer. The
latitude at which this will become focused remains a bit uncertain,
and by late Friday afternoon will largely depend on where outflow
from prior convection ends up and the extent to which it modifies.
However, corridors of stronger differential heating and developing
low-level warm advection might contribute to an environment
conducive to the evolution of at least small organizing clusters
with potential to produce severe wind and hail across eastern
portions of the central Great Plains into the Tennessee Valley
through Friday evening.
In the wake of the eastward migrating weak mid-level trough,
convection-allowing guidance suggests that easterly low-level flow
into portions of the Front Range, Sangre de Cristo Mountains and
Raton Mesa/ridge vicinity will be sufficiently moist and unstable,
in the presence of steep lapse rates, to support scattered strong
thunderstorm development. Some of these may become capable of
producing severe hail and wind.
..Kerr.. 07/09/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0215 AM CDT Thu Jul 09 2026
Valid 111200Z - 121200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE SATURDAY
AFTERNOON AND EVENING ACROSS PARTS OF THE SOUTH CENTRAL GREAT PLAINS
THROUGH THE MID SOUTH AND TENNESSEE VALLEY...
...SUMMARY...
Strong thunderstorms with potential to produce a few damaging wind
gusts are possible in a corridor across the south central Great
Plains through Mid South and Tennessee Valley Saturday afternoon and
evening.
...Discussion...
Large-scale mid/upper ridging is forecast to continue building
across much of interior North America through this period, with the
strong core of the ridge expanding northeastward and encompassing
much of the Four Corners states through middle Missouri Valley by
late Saturday night. While one notable short wave trough is forced
inland across the British Columbia coast, increasingly split
downstream troughing is forecast to progress toward the northwestern
Atlantic, and offshore of the north Atlantic Seaboard. A lingering
mid-level shear axis, trailing to the west of the latter troughing,
may slowly continue to shift south of the Mid Atlantic and lower
Ohio/Missouri Valleys through the period.
In general, the risk for organized severe convection appears low
Saturday through Saturday night, or at least dependent on mesoscale
perturbations with low predictability at this time frame. However,
there does appear a general consensus among model output that
lower/mid-tropospheric lapse rates may remain steep enough, above a
seasonably moist boundary layer, to contribute to moderate CAPE (on
the order of 1500-2000+ J/kg) in advance of the southward advancing
shear axis. By late Saturday afternoon into Saturday evening, this
may focus strong thunderstorm development in a corridor from the
south central Great Plains into the Tennessee Valley. Some of this
activity may evolve into small clusters with potential to produce
strong to locally severe surface gusts.
..Kerr.. 07/09/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Thu Jul 09 2026
Valid 121200Z - 171200Z
...DISCUSSION...
Medium-range models continue to indicate that the center of strong
mid-level ridging building northeast of the Four Corners states will
shift across the middle Missouri Valley early next week, where it
may reach peak intensity by about Tuesday, before becoming
suppressed. Even as this commences, mid-level ridging in the
westerlies may be maintained near and north/northeast of the
international border, from the Great Plains through the Great Lakes,
while large-scale downstream troughing amplifies southeastward
across the Northeast.
Associated with this evolution, a plume of very warm elevated
mixed-layer air still appears likely to advect on the southern
fringe of a belt of strengthening flow around the northern through
northeastern periphery of this ridging. As the nose of the warmer
air overspreads the Great Lakes region early next week, forcing for
ascent associated with warm advection could begin supporting
organizing thunderstorm clusters potentially impacting portions of
New England, and/or the lower Great Lakes through Mid Atlantic.
As guidance suggests that the westerlies will initially remain split
downstream of the ridge, and a potentially notable short wave trough
(and associated cold front) migrating around its periphery and
eventually suppressing it, it remains unclear how potential frontal
and pre-frontal convection will pan out on any particular day. Due
to both synoptic and sub-synoptic predictability issues, severe
probabilities remain at less than 15 percent in the day 6-8 time
frame. However, this probably will change in later outlooks closer
to this time period, when the potential for introducing unduly large
forecast false alarm decreases.
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1241 AM CDT Thu Jul 09 2026
Valid 091200Z - 101200Z
...Synopsis...
Another upper low will move into southwest Canada as the upper high
continues near the southern California coast. West-southwest flow
aloft will spread over much of the West, with the strongest
mid-level flow across central/southern California into northern
Arizona. A weak, Pacific cold front will stall out and weaken
further across the northern Great Basin and northern Rockies after
passing through the Inland Northwest.
West-southwest sustained winds of 12-20 mph with gusts of 20-40 mph
amid minimum RH of 5-15% are expected across inland southern
California and stretching across the southern Great Basin into the
Four Corners. The strongest gusts will be along/east the southern
Sierra/vicinity during the late afternoon and evening. Additionally,
elevated conditions are possible on portions of the Snake River
Plain near the weakening Pacific cold front. Given the recent
lightning, active large wildfires, and near to record dry fuels,
holdovers and growth on existing large fires are a concern for
portions of Nevada, Utah, and western Colorado.
Isolated dry thunderstorms are likely from northeast Nevada into
western Colorado. Enough residual mid-level moisture along with a
deep well mixed boundary layer and terrain circulations should
combine to produce isolated to possibly scattered mostly dry
thunderstorms. Deep pyroconvection on active large wildfires
in/around the IsoDryT area remain a concern.
Elevated conditions are possible in portions of the Carolinas and
eastern Georgia as west-southwest sustained winds of 8-15 mph and
minimum RH of 30-40% develop during the afternoon. ERCs are above
the 90th percentile across these areas. However, the potential for
showers and thunderstorms in the afternoon/evening and low
confidence in more than locally elevated conditions developing
precludes an Elevated area at this time.
..Nauslar.. 07/09/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1243 AM CDT Thu Jul 09 2026
Valid 101200Z - 111200Z
...Synopsis...
An upper-level trough will move towards and deepen offshore from the
Pacific Northwest, while the upper high will shift eastward over
southern California. Stronger mid-level winds will begin to
overspread the Northwest with the onshore pressure gradient
strengthening again as a Pacific cold front moves into the
Northwest. Mid-level moisture that has been present across the Great
Basin and Four Corners will continue to push east of the Front Range
and suppressed southward to southern Arizona/New Mexico.
Dry and breezy conditions are expected to develop across much of the
Great Basin into the Four Corners. West-southwest sustained winds of
12-20 mph amid minimum RH of 8-20% are likely to develop from
central/eastern Oregon to the Four Corners. The strongest winds are
likely across the Sierra Front and northwest Nevada into portions of
southeast Oregon and southwest Idaho. While winds will not be as
strong across portions of central/northern Utah into western
Colorado, locally elevated conditions are expected. Locally elevated
conditions may extend into portions of southeast/eastern Idaho as
well.
Isolated high-based showers and thunderstorms are possible across
portions of southeast Idaho, northern Utah, and northwest Colorado.
While building to towering Cu are likely over the higher terrain,
thunderstorm chances are less than 10%, with high-based convective
showers with little to no rainfall reaching the ground more likely.
..Nauslar.. 07/09/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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