RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
1135 AM CDT Mon Jul 14 2025
Valid 141630Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
MID-ATLANTIC AS WELL AS FAR EAST-CENTRAL WYOMING...SOUTHWEST SOUTH
DAKOTA...AND THE FAR NORTHERN NEBRASKA PANHANDLE...
CORRECTED FOR INCORRECT GEOGRAPHIC DESCRIPTION IN HEADLINE
...SUMMARY...
Strong to severe thunderstorms are possible across parts of the
northern Plains as well as the Mid-Atlantic States this afternoon
into tonight. Isolated strong to severe thunderstorms are possible
across the Mid-South, southeast Arizona, and Florida.
...Mid-Atlantic into the Northeast...
A belt of stronger mid-level flow extends from the north-central
CONUS/south-central Canadian Prairies through the Northeast, with
some modest cyclonic curvature. A more defined shortwave trough is
currently progressing into the Upper OH Valley/central Appalachians,
along the southern periphery of the belt of stronger, broadly
cyclonic flow. Showers and isolated thunderstorms are currently
ongoing just ahead of this shortwave.
Expectation is for this shortwave trough to continue
eastward/northeastward throughout the day, with the modest upper
troughing farther north shifting eastward as well. A reservoir of
ample low-level moisture (i.e. dewpoints in the low to mid 70s) is
in place ahead of this shortwave. This low-level moisture will
support airmass destabilization and moderate buoyancy this afternoon
despite widespread cloudiness and tempered daytime heating.
Thunderstorm development is anticipated as large-scale ascent
attendant to the approaching shortwave (and larger upper trough)
moves into the region. Additionally, recent surface analysis places
a trough axis from the northern NY/VT border southwestward through
central PA. Low-level convergence along this axis could augment the
large-scale ascent. All of these factors will act to support
scattered to numerous thunderstorms this afternoon.
While mid-level flow and related deep-layer shear are both expected
to remain fairly modest, some of this convection could congeal into
multiple loosely organized clusters. Steepened low-level lapse rates
and water loaded downdrafts could support isolated strong to
damaging winds as thunderstorms spread generally eastward through
the afternoon and evening. Highest thunderstorm coverage and
greatest relative chance for damaging gusts is expected from eastern
PA through central VA.
...Northern Plains to Northern Minnesota...
Satellite imagery shows a vorticity maximum drifting slowly across
the central Intermountain West. Large-scale ascent attendant to this
vorticity maximum will augment low-level convergence along a
sharpening lee trough, likely resulting in enough lift to promote
thunderstorm development across eastern WY during the late
afternoon. This area is on the southern periphery of a belt of
stronger westerlies, and there appears to be just enough westerly
flow aloft for updraft organization and persistence into the better
moisture and buoyancy farther east. As such, there is a risk for
strong to severe gusts within this deeply mixed airmass throughout
the afternoon and evening.
Thunderstorm development also appears possible along a surface
trough that arcs from western MT to a low in southwest SD. A
conditional severe risk exists with any storms that develop near the
surface low over ND this afternoon, but the greater thunderstorm
coverage is anticipated later this evening and overnight as warm-air
advection across the frontal zone strengthens. Elevated
thunderstorms are also expected tonight as an
upper trough overspreads the northern Rockies. Given ample shear and
buoyancy, isolated hail is possible in both of these regions
tonight.
...Eastern GA into the FL Peninsula...
Ample low-level moisture and robust diurnal heating will result in
strong buoyancy from eastern GA southward across the entire FL
Peninsula this afternoon. A modest cyclone drifting westward towards
the GA/FL coast will interact with this airmass, contributing to
widespread thunderstorm development this afternoon. Convection
should develop along/near the Atlantic Coast before spreading
south-southwestward and inland across much of the FL Peninsula this
afternoon/evening. Several clusters capable of producing isolated
strong to severe winds are possible.
...AZ...
High pressure over the southern Great Basin will contribute to
around 20-25 kt of northeasterly mid-level flow across southern AZ
this afternoon. This mid-level flow will take storms that develop
across the higher terrain southwestward into the deeply mixed
boundary layer over southeast AZ. A few strong to severe gusts are
possible, but overall coverage will likely be sparse.
...South-Central/Southeast TX into the Mid-South...
A trio of MCVs is apparent on radar and satellite imagery this
morning. One is centered over Real and Uvalde Counties in the TX
Hill Country, with another over Denton and Collin Counties in north
TX, and the third farther north over northeast AR. At least
scattered thunderstorms are possible this afternoon/evening with
each of these MCVs as they progress eastward/northeastward. Vertical
shear will be weak, but discrete storm propagation along the
stronger outflows could result in occasionally strong/damaging
downbursts.
..Mosier.. 07/14/2025
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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0257 PM CDT Mon Jul 14 2025
Valid 142000Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE MID-ATLANTIC AND THE NORTHERN PLAINS...
...SUMMARY...
Strong to severe thunderstorms are possible across parts of the
northern Plains as well as the Mid-Atlantic States this afternoon
into tonight. Isolated strong to severe thunderstorms are possible
across the East, Mid-South, southeast Arizona, and Florida.
...20z Update...
The previous outlook remains on track and no significant changes
were made with this update. Towering cumulus/initial storm
development is underway across the higher terrain of WY and, as
remaining CINH as shown on the 18z Rapid City Sounding is removed
via diurnal heating, additional development is expected in the
vicinity of the Black Hills. Storms should tend to evolve into
clusters/line segments while moving east this afternoon and evening.
Very steep low- and mid-level lapse rates and dry low levels above
the boundary layer will result in a damaging wind risk, and an
isolated potential for severe hail with isolated stronger storms.
Across the mid-Atlantic, thunderstorms continue to develop and move
east within a very moist/moderately unstable air mass. Please refer
to Mesoscale Convective Discussion 1668 for the latest short-term
thinking regarding convective evolution in this area.
..Bunting.. 07/14/2025
.PREV DISCUSSION... /ISSUED 1135 AM CDT Mon Jul 14 2025/
...Mid-Atlantic into the Northeast...
A belt of stronger mid-level flow extends from the north-central
CONUS/south-central Canadian Prairies through the Northeast, with
some modest cyclonic curvature. A more defined shortwave trough is
currently progressing into the Upper OH Valley/central Appalachians,
along the southern periphery of the belt of stronger, broadly
cyclonic flow. Showers and isolated thunderstorms are currently
ongoing just ahead of this shortwave.
Expectation is for this shortwave trough to continue
eastward/northeastward throughout the day, with the modest upper
troughing farther north shifting eastward as well. A reservoir of
ample low-level moisture (i.e. dewpoints in the low to mid 70s) is
in place ahead of this shortwave. This low-level moisture will
support airmass destabilization and moderate buoyancy this afternoon
despite widespread cloudiness and tempered daytime heating.
Thunderstorm development is anticipated as large-scale ascent
attendant to the approaching shortwave (and larger upper trough)
moves into the region. Additionally, recent surface analysis places
a trough axis from the northern NY/VT border southwestward through
central PA. Low-level convergence along this axis could augment the
large-scale ascent. All of these factors will act to support
scattered to numerous thunderstorms this afternoon.
While mid-level flow and related deep-layer shear are both expected
to remain fairly modest, some of this convection could congeal into
multiple loosely organized clusters. Steepened low-level lapse rates
and water loaded downdrafts could support isolated strong to
damaging winds as thunderstorms spread generally eastward through
the afternoon and evening. Highest thunderstorm coverage and
greatest relative chance for damaging gusts is expected from eastern
PA through central VA.
...Northern Plains to Northern Minnesota...
Satellite imagery shows a vorticity maximum drifting slowly across
the central Intermountain West. Large-scale ascent attendant to this
vorticity maximum will augment low-level convergence along a
sharpening lee trough, likely resulting in enough lift to promote
thunderstorm development across eastern WY during the late
afternoon. This area is on the southern periphery of a belt of
stronger westerlies, and there appears to be just enough westerly
flow aloft for updraft organization and persistence into the better
moisture and buoyancy farther east. As such, there is a risk for
strong to severe gusts within this deeply mixed airmass throughout
the afternoon and evening.
Thunderstorm development also appears possible along a surface
trough that arcs from western MT to a low in southwest SD. A
conditional severe risk exists with any storms that develop near the
surface low over ND this afternoon, but the greater thunderstorm
coverage is anticipated later this evening and overnight as warm-air
advection across the frontal zone strengthens. Elevated
thunderstorms are also expected tonight as an
upper trough overspreads the northern Rockies. Given ample shear and
buoyancy, isolated hail is possible in both of these regions
tonight.
...Eastern GA into the FL Peninsula...
Ample low-level moisture and robust diurnal heating will result in
strong buoyancy from eastern GA southward across the entire FL
Peninsula this afternoon. A modest cyclone drifting westward towards
the GA/FL coast will interact with this airmass, contributing to
widespread thunderstorm development this afternoon. Convection
should develop along/near the Atlantic Coast before spreading
south-southwestward and inland across much of the FL Peninsula this
afternoon/evening. Several clusters capable of producing isolated
strong to severe winds are possible.
...AZ...
High pressure over the southern Great Basin will contribute to
around 20-25 kt of northeasterly mid-level flow across southern AZ
this afternoon. This mid-level flow will take storms that develop
across the higher terrain southwestward into the deeply mixed
boundary layer over southeast AZ. A few strong to severe gusts are
possible, but overall coverage will likely be sparse.
...South-Central/Southeast TX into the Mid-South...
A trio of MCVs is apparent on radar and satellite imagery this
morning. One is centered over Real and Uvalde Counties in the TX
Hill Country, with another over Denton and Collin Counties in north
TX, and the third farther north over northeast AR. At least
scattered thunderstorms are possible this afternoon/evening with
each of these MCVs as they progress eastward/northeastward. Vertical
shear will be weak, but discrete storm propagation along the
stronger outflows could result in occasionally strong/damaging
downbursts.
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1236 PM CDT Mon Jul 14 2025
Valid 151200Z - 161200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
AND NORTHERN PLAINS AND WESTERN GREAT LAKES REGION...
...SUMMARY...
Strong to severe thunderstorms are possible Tuesday afternoon and
evening across portions of the central Plains to Upper Midwest.
Isolated damaging gusts are also possible over parts of the northern
Great Basin.
...Central/Northern Plains to the upper Midwest...
A positive-tilt upper trough is forecast to eject eastward with
several weaker leading disturbances located across the northern
Rockies Tuesday. Coincident with increasing mid/upper westerly flow,
height falls and weak ascent will support the development of a
surface low over western SD. This low will move into southern MN by
Wednesday morning, while a cold front will sag southward across MT,
the Dakotas and northern MN.
South of the front and surface low, a seasonably warm/humid air mass
will be in place near the triple point across NE and eastern SD,
extending northward along the front into the upper Midwest. Moderate
to strong destabilization (2500-3500 J/kg MLCAPE), and ascent from
the approaching upper troughs will promote scattered strong to
severe storms by the afternoon. Vertical shear around 25-35 kt will
support a mix of cells and clusters capable of damaging gusts and
hail.
A fairly quick transition to upscale growth is likely Tuesday
evening given the large buoyancy and weaker low-level flow allowing
for consolidation of outflow. Most CAM solutions show eventual MCS
development across central/southeast NE into the overnight hours.
Aided by a 40+ kt southerly low-level jet, this MCS could continue
into parts of western IA and northern KS with a risk for damaging
gusts through 12z.
Farther northeast along the front, veered low-level flow and largely
unidirectional wind profiles should favor a predominately linear
storm mode. One or more clusters may emerge primarily with a risk
for damaging gusts and hail as they moving from MN to northern WI
and western upper MI by Tuesday evening. Locally stronger flow aloft
and near the front could also support a brief tornado or two.
Isolated hail and damaging gusts will also be possible in the
post-frontal upslope flow regime across northern and eastern WY into
western SD. Enhanced mid-level flow and 500-1000 J/kg of MUCAPE
could support a few supercells or stronger clusters near and along
the front.
...Eastern Great Basin...
As the cold front gradually moves south, it should begin to stall
across the northern Great basin Tuesday afternoon. As forcing for
ascent from the upper trough interacts with strong diurnal heating,
scattered thunderstorm are expected along the front and adjacent
higher terrain from northeast NV, through northern UT and into
southwestern WY. Weak to moderate SBCAPE atop deep inverted-V
structures will favor strong downdrafts with these high-based
storms. Damaging gust potential will be maximized along the front
where locally stronger convergence and deep-layer shear should
support a larger concentration and greater persistence of
strong/occasionally severe storm clusters.
...Mid MS Valley...
Scattered to numerous thunderstorms remain likely with several
convectively augmented vort maxima/MCVs currently observed across
central/northeast TX. While less defined than previous guidance
cycles, locally stronger forcing for ascent and enhanced
low/mid-level flow could support one or more clusters of strong to
occasional severe storm Tuesday afternoon across the Mid MS Valley.
These clusters will develop within a very warm/unstable air mass
with the potential for occasional damaging gusts from heavily
water-loaded downdrafts. As mentioned in the prior outlook,
confidence in the ultimate location of theses features as well as
the resulting storm coverage/intensity remains too low to introduce
higher severe probabilities.
...Southern AZ...
Weak easterly flow and seasonably high monsoon moisture south of the
upper ridge are expected to support scattered thunderstorms across
parts of southern AZ Tuesday afternoon and evening. While steering
flow is not overly strong, some enhancement of the mid-level
easterlies could promote slightly more organized storm clusters
capable of damaging gusts given the deeply mixed PBL.
...Southeast and FL...
A weak tropical wave will likely serve as a focus for numerous
thunderstorms Tuesday and Tuesday night across parts of FL and the
Gulf Coast. A warm, unstable and humid air mass will support
numerous thunderstorm clusters over a broad area capable of sporadic
damaging downbursts through much of the day. Locally higher severe
probabilities will be greatest along sea breeze boundaries and near
the upper vort max. However, confidence in more than occasional
severe potential is low.
..Lyons.. 07/14/2025
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0224 PM CDT Mon Jul 14 2025
Valid 161200Z - 171200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
HIGH PLAINS EASTWARD TO THE GREAT LAKES AND MIDWEST...
...SUMMARY...
Scattered strong to severe thunderstorms are possible Wednesday
afternoon and evening from parts of the central High Plains to the
Great Lakes.
...Central Plains...
At the start of the period, several areas of convection are likely
to be ongoing from eastern NE into northern KS and western IA.
Additional storms are likely ahead of the slow-moving cold
front/composite outflow sagging south from eastern WY and the
Rockies. Re-intensification and additional storm development appears
likely ahead of the boundary as a broad shortwave trough/MCV shift
eastward. The stronger vertical shear will likely lag to the north
of the front, casting some uncertainty on storm character. However,
sufficient buoyancy/shear should still support a damaging gust and
hail risk from the central High plains eastward.
...Great Lakes...
As the shortwave trough/MCV moves eastward ahead of the front,
redevelopment of scattered showers and thunderstorms is possible
Wednesday across parts of WI into northern IL and MI. Enhanced
westerly flow could support some severe risk with these storms
through the afternoon and potentially across the lower Great lakes
overnight. Confidence in the evolution of this threat is low but the
general environment will be favorable for severe storms with
2000-3000 J/kg of MLCAPE and 25-30+ kt of effective shear.
...Gulf Coast...
A tropical wave over the northern Gulf will likely support numerous
thunderstorms Wednesday afternoon and evening. A very high PWAT air
mass (> 2 inches) and slight enhancement of mid-level easterly shear
could allow for brief storm organization along the immediate central
Gulf Coast. Sporadic damaging gusts or a brief tornado could occur,
though convective details remain limited.
...Upper OH Valley...
On the fringes of the strong sub-tropical ridging, prior convection
could result in the development of an MCV across the OH valley and
central Appalachians early Wed. Should this occur, scattered storms
may redevelop through the morning across the Upper OH valley.
Slightly enhanced flow aloft and high PWATs would suggests some risk
for damaging gusts is possible. However, confidence in the overall
scenario is too low for higher probabilities at this time.
..Lyons.. 07/14/2025
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