LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1121 AM CDT Wed Jul 22 2026
Valid 221630Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING FOR MAINE AND THE MID-ATLANTIC...
...SUMMARY...
Scattered storms are expected across the Carolinas and southern
Mid-Atlantic, as well as New England this afternoon and early
evening, with damaging winds as the primary concern. Isolated strong
to severe wind gusts are also possible in the central High Plains,
southeast Texas and central Oregon, where isolated large hail will
also be possible.
...Northern New England this afternoon...
Per water vapor imagery and morning upper air observations, a
pronounced midlevel trough will progress east-northeastward from
PA/NY/Saint Lawrence Valley toward New England through this
afternoon. An associated surface cold front will likewise move
eastward and provide a focus for thunderstorm development by early
afternoon into Maine. A few cloud breaks developing from
west-to-east through the afternoon will allow surface temperatures
to warm into the 70s with boundary-layer dewpoints in the mid 60s,
resulting in MLCAPE in the 1000-1500 J/kg range. Deep-layer,
south-southwesterly shear will be sufficient for a mix of clusters
and supercells with a primary threat for occasional wind damage.
...Mid-Atlantic this afternoon/evening...
A pre-frontal band of convection is ongoing across southern VA, with
a narrow zone of stronger surface heating/destabilization to the
north of the thicker clouds from northern VA into MD/DE in advance
of a cold front moving across PA. The southern fringe of the
stronger (35-50 kt) midlevel flow extends to near the VA/NC border
on the south side of the thicker cloud band. The ongoing convection
is likely persist through the afternoon while spreading slowly
southward. Midlevel lapse rates will remain poor, but deep-layer
vertical shear will be sufficient for embedded/organized storms with
occasional wind damage. Low-level shear will be marginally
favorable for rotating storms and perhaps an isolated tornado.
...Southeast TX late this afternoon through late evening...
Strong surface heating is underway with a general confluence zone
near the TX/LA border well to the west of highly-sheared Tropical
Storm Bertha. As Bertha continues westward, this confluence zone
should support thunderstorm development into southeast TX late this
afternoon. Steering flow from the northeast at ~35 kt will favor
storm clusters moving southwestward into a hot, deeply mixed
boundary layer where buoyancy will be sufficient to maintain the
storm clusters into late evening. A few strong-severe outflow gusts
will be the main threats.
...Northeast CO and vicinity this afternoon/evening...
Low-level upslope flow on the cool side of a surface front, combined
with weak perturbations rotating around the northwest periphery of
the southern Plains midlevel high, will support afternoon
thunderstorm development over the foothills. The storms will spread
east-southeastward onto the plains, with a tendency for clustering
with the potential for isolated severe outflow gusts.
...OR this afternoon/evening...
Along the northwest edge of the monsoonal moisture plume, a midlevel
shortwave trough will move northward from northern CA into OR. Weak
forcing for ascent combined with daytime heating over the higher
terrain will support scattered thunderstorms later this
afternoon/evening from the Cascades into central OR. An environment
with MLCAPE of 500-1000 J/kg, steepening low-level lapse rates and
effective bulk shear near 25 kt will support isolated strong outflow
gusts and marginally severe hail.
..Thompson/Chalmers.. 07/22/2026
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Wednesday, July 22, 2026
SPC Jul 22, 2026 0600 UTC Day 1 Convective Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CDT Wed Jul 22 2026
Valid 221200Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN MID-ATLANTIC...
...SUMMARY...
Isolated to scattered storms are possible in the southern
Mid-Atlantic into New England this afternoon/evening. Damaging winds
are the primary concern. Isolated strong to severe wind gusts are
also possible in the central High Plains and central Oregon.
...Synopsis...
A upper trough will persist in the Northeast CONUS with a ridge
amplifying into the Northwest. An offshore upper low in the
Northwest will eject shortwave perturbations into Oregon/Washington.
At the surface, a cold front will move through New England. The
front will slow in the Mid-Atlantic during the afternoon before
moving southeast during the overnight.
...Mid-Atlantic into parts of Carolinas...
The cold front in this region is expected to slow/stall near the
Blue Ridge into eastern Maryland. Models suggest
clouds/precipitation will be likely in the vicinity of the
Virginia/North Carolina border. Mid-level forcing for ascent will be
weak at best and subtle mid-level warming is expected from far
southern Virginia into the Carolinas. Moderate to strong mid-level
winds will be in place with the strongest flow in Virginia/Maryland.
It is not clear how convection will evolve during the day/afternoon.
Storms could potentially continue from the morning into the
afternoon over portions of the region. There also is potential for
storms to develop along the cold front where there could potentially
be greater surface heating. In the Carolinas, the lack of ascent and
cloud cover concerns limit confidence in how many storms and how
strong they will become. Greater confidence in storm coverage exists
in Virginia into the DelMarVa where the Slight Risk has been
maintained. The kinematic environment will support occasionally
organized storms capable of damaging winds and perhaps a tornado or
two.
...New England...
A strong mid-level jet will be favorably timed during the afternoon,
particularly for New Hampshire/Maine. As the cold front moves
through, scattered storms appear probable. Effective shear of 30-40
kt and strong upper-level winds will promote supercell structures.
The shear vector will have a large component parallel to the
north-south cold front so it is not clear how long discrete
structures can be maintained. Isolated damaging winds, marginally
severe hail, and perhaps a tornado would be possible. Some
consideration was given to a higher severe probabilities, but the
region will initially be in the wake of a shortwave trough and
thermodynamic profiles exhibit characteristics (e.g., mid-level
inversion, lowered equilibrium level) that limits confidence in how
many severe-caliber storms will exist.
Farther south and west, there is less signal for convective
development along the cold front. A Marginal risk has been
maintained this outlook cycle. Some risk for damaging winds would
exist if an isolated storm can develop along the front.
...Central High Plains...
Southeasterly surface winds will combine with increasingly
westerly/northwesterly flow aloft to promote modest deep-layer shear
(around 30 kt 0-6 km) during the afternoon/evening. The development
of a weak lee low and low-level moisture moving northwest around the
Midwest anticyclone will aid in storm development within the region.
Temperature-dewpoint spreads at the surface will allow for efficient
outflow production. A strengthening southeasterly low-level jet in
western Kansas may also help maintain convection farther east during
the evening. Severe wind gusts are possible with this activity.
...Oregon...
An upper-low will be positioned off the Northwest Coast. Subtle
ascent will help to initiate storms in parts of central Oregon
during the afternoon. Models are in strong agreement that scattered
storms will move northward into at least early evening. Strong
heating will lead to large temperature-dewpoint spreads at the
surface. Inverted-v thermodynamic profiles will promote a risk for
strong to severe wind gusts despite limited buoyancy and shear.
..Wendt/Weinman.. 07/22/2026
Read more CHECK UPDATE ZOOM GRAPHIC
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Tuesday, July 21, 2026
SPC Jul 21, 2026 2000 UTC Day 1 Convective Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0301 PM CDT Tue Jul 21 2026
Valid 212000Z - 221200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS
OF THE NORTHEAST AND MID ATLANTIC TO THE OHIO VALLEY...
...SUMMARY...
Numerous severe thunderstorms are expected across a broad region
from the Tennessee and Ohio Valleys to the Mid-Atlantic and
Northeast States into tonight. Swaths of damaging wind gusts are
expected to be the most common impact, but some tornadoes and hail
are possible as well.
...20z Update Mid Atlantic and New England...
A complicated convective situation continues across the area with
numerous cluster of strong to severe storms ongoing from southern
NY/CT/MA to the DelMarVA. A diffuse warm frontal zone from the
Hudson valley to Long Island and the Atlantic coast has supported a
few instances of stronger rotating supercells and QLCS structures.
This focus may continue as additional more discrete storms approach
from northern NJ and eastern PA. Otherwise, clustering of storms
ahead of the cold front and across VA will pose a risk for damaging
gusts through this evening. The primary update to the outlook was to
lower probabilities behind the ongoing convection over NY and
northeast OH where the air mass has been partially overturned.
Isolated damaging gusts and some hail remain possible tonight.
...OH Valley...
A broken band of storms ahead of a cold front, extending into WV and
southwest PA should continue to track east/southeast through this
afternoon and into the evening hours. Strong northwesterly flow
aloft is supporting moderate deep-layer shear and a mixed mode of
supercells and clusters across southern IN/OH and into northern KY.
A primary risk for damaging winds is expected given upscale growth
as storm coverage increases. However, the large buoyancy (MLCAPE
3000-4000 J/kg) and some supercell structures could support large
hail. Some tornado potential will also exist with the semi-discreet
supercells and QLCS structures. This appears most likely near a
convective modified boundary from astern OH into WV and southwest
PA.
Storm coverage should continue to increase this afternoon across
western KY and the lower OH Valley. With a predominately linear
storm mode expected along the cold front, damaging winds are the
most likely hazard. The primary change to the probabilities was to
trim behind the front over OH/IN. See the prior outlook for more
information.
..Lyons.. 07/21/2026
.PREV DISCUSSION... /ISSUED 1118 AM CDT Tue Jul 21 2026/
...Tennessee/Ohio Valley into the Mid-Atlantic and Northeast...
Recent satellite imagery reveals a shortwave trough moving quickly
southeastward across the Upper Great Lakes region, embedded within
the upper troughing that covers much of eastern Canada and extends
down into the Ohio Valley. Moderate mid-level flow accompanies this
shortwave, with wind speeds greater than 50 kt sampled around 500 mb
on the 12Z ILX, DTX, ILN, and PIT soundings. The strongest flow was
sampled at ILX and DTX, and the expectation is for this stronger
flow to spread eastward today, moving in tandem with the progressive
shortwave.
Showers and thunderstorms are already ongoing downstream of this
shortwave, with the highest coverage along and near the pre-frontal
trough in Ohio. Recent surface analysis reveals a somewhat complex
boundary structure, with a wavy warm front, a diffuse pre-frontal
trough, and a cold front. Primary warm front appears to extend
west-to-east from southeast Ohio across southern Pennsylvania and
into northern New Jersey, far southern New York, and extreme
southwest Connecticut. The cold front arcs southwestward from
northern Lower Michigan through central Illinois and central
Michigan.
Highest overall coverage is anticipated along and ahead of the cold
front this afternoon through this evening, with additional
development expected farther east (from central Pennsylvania into
central Virginia) along the lee trough as well. Highest buoyancy is
expected along the western periphery of the cold front from central
into western Kentucky, where mid to upper 70s dewpoints are
anticipated amid temperatures in the upper 80s/low 90s. Strong
buoyancy is still anticipated across Ohio as well. Robust
thunderstorm development is expected along the front. Vertical shear
is robust enough for supercells, but linear forcing along the front
and strong downdraft production will likely lead to quick upscale
growth. In either convective mode, damaging gusts (with speeds from
55 to 70 mph) will be the primary risk, with brief tornadoes as a
secondary threat, and large hail tertiary.
Farther east, a similar convective environment exists, although with
slightly less buoyancy and deep-layer vertical shear. A more
outflow-dominant multicell mode is anticipated across the central
Virginia vicinity, with a trend towards a more organized mode
possible with northern extent. Primary risk will be damaging gusts,
including a few around 65 to 70 mph. A somewhat confined corridor of
greater tornado potential exists from the Hudson Valley vicinity
into western Massachusetts/Connecticut as the warm front lifts
northward. Here, enhanced vorticity along the boundary coupled with
stronger low-level southerly flow could support a few brief
tornadoes.
...Great Basin...
Scattered to numerous thunderstorms are expected across the Great
Basin today, supported by strong diurnal heating/mixing and moderate
mid-level moisture along the western periphery of the upper ridging
centered over the central Rockies. A few strong updrafts/downdrafts
are possible, with an attendant risk for strong to severe (i.e. 50
to 65 mph) wind gusts.
...Gulf Coast...
Tropical Storm Bertha is expected to continue to drift
west-northwestward over the northern Gulf tonight from off the coast
of the Florida Panhandle toward the southern Mississippi/southern
Alabama coast. Reference the National Hurricane Center for the
latest details.
A strong low-level wind field will approach these coastal areas
later today and tonight. However, as is typical for a westward
moving tropical cyclone, forecast SRH should remain relatively
modest inland. Given the marginal thermodynamic profiles (aside from
the rich boundary layer moisture) and limited SRH over land, any
Bertha-related mini-supercell potential is expected remain offshore.
Read more CHECK UPDATE ZOOM GRAPHIC
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SPC Jul 21, 2026 1630 UTC Day 1 Convective Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1118 AM CDT Tue Jul 21 2026
Valid 211630Z - 221200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY TO MID-ATLANTIC STATES...
...SUMMARY...
Numerous severe thunderstorms are expected across a broad region
from the Tennessee and Ohio Valleys to the Mid-Atlantic and
Northeast States today into tonight. Swaths of damaging wind gusts
are expected to be the most common impact, but some tornadoes are
possible as well.
...Tennessee/Ohio Valley into the Mid-Atlantic and Northeast...
Recent satellite imagery reveals a shortwave trough moving quickly
southeastward across the Upper Great Lakes region, embedded within
the upper troughing that covers much of eastern Canada and extends
down into the Ohio Valley. Moderate mid-level flow accompanies this
shortwave, with wind speeds greater than 50 kt sampled around 500 mb
on the 12Z ILX, DTX, ILN, and PIT soundings. The strongest flow was
sampled at ILX and DTX, and the expectation is for this stronger
flow to spread eastward today, moving in tandem with the progressive
shortwave.
Showers and thunderstorms are already ongoing downstream of this
shortwave, with the highest coverage along and near the pre-frontal
trough in Ohio. Recent surface analysis reveals a somewhat complex
boundary structure, with a wavy warm front, a diffuse pre-frontal
trough, and a cold front. Primary warm front appears to extend
west-to-east from southeast Ohio across southern Pennsylvania and
into northern New Jersey, far southern New York, and extreme
southwest Connecticut. The cold front arcs southwestward from
northern Lower Michigan through central Illinois and central
Michigan.
Highest overall coverage is anticipated along and ahead of the cold
front this afternoon through this evening, with additional
development expected farther east (from central Pennsylvania into
central Virginia) along the lee trough as well. Highest buoyancy is
expected along the western periphery of the cold front from central
into western Kentucky, where mid to upper 70s dewpoints are
anticipated amid temperatures in the upper 80s/low 90s. Strong
buoyancy is still anticipated across Ohio as well. Robust
thunderstorm development is expected along the front. Vertical shear
is robust enough for supercells, but linear forcing along the front
and strong downdraft production will likely lead to quick upscale
growth. In either convective mode, damaging gusts (with speeds from
55 to 70 mph) will be the primary risk, with brief tornadoes as a
secondary threat, and large hail tertiary.
Farther east, a similar convective environment exists, although with
slightly less buoyancy and deep-layer vertical shear. A more
outflow-dominant multicell mode is anticipated across the central
Virginia vicinity, with a trend towards a more organized mode
possible with northern extent. Primary risk will be damaging gusts,
including a few around 65 to 70 mph. A somewhat confined corridor of
greater tornado potential exists from the Hudson Valley vicinity
into western Massachusetts/Connecticut as the warm front lifts
northward. Here, enhanced vorticity along the boundary coupled with
stronger low-level southerly flow could support a few brief
tornadoes.
...Great Basin...
Scattered to numerous thunderstorms are expected across the Great
Basin today, supported by strong diurnal heating/mixing and moderate
mid-level moisture along the western periphery of the upper ridging
centered over the central Rockies. A few strong updrafts/downdrafts
are possible, with an attendant risk for strong to severe (i.e. 50
to 65 mph) wind gusts.
...Gulf Coast...
Tropical Storm Bertha is expected to continue to drift
west-northwestward over the northern Gulf tonight from off the coast
of the Florida Panhandle toward the southern Mississippi/southern
Alabama coast. Reference the National Hurricane Center for the
latest details.
A strong low-level wind field will approach these coastal areas
later today and tonight. However, as is typical for a westward
moving tropical cyclone, forecast SRH should remain relatively
modest inland. Given the marginal thermodynamic profiles (aside from
the rich boundary layer moisture) and limited SRH over land, any
Bertha-related mini-supercell potential is expected remain offshore.
..Mosier/Chalmers.. 07/21/2026
Read more CHECK UPDATE ZOOM GRAPHIC
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