SPC Jul 4, 2026 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1101 AM CDT Sat Jul 04 2026

Valid 041630Z - 051200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE MID-ATLANTIC AS WELL AS ACROSS PORTIONS OF SOUTHERN KANSAS
AND NORTHERN OKLAHOMA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
PLAINS INTO THE MID ATLANTIC AND SOUTHERN NEW ENGLAND...

...SUMMARY...
Clusters of storms will move across parts of the Allegheny Plateau
into the Mid-Atlantic, with potential for numerous damaging wind
gusts. Additional severe thunderstorms are expected across the Great
Plains this afternoon and evening, posing a risk for severe wind
gusts and large hail.

...Mid Atlantic...
A hot summer day is forecast across the Mid Atlantic region today
with temperatures well into the 90s and dewpoints ranging from the
mid 60-lower 70s F. Full sun will result in steep low-level lapse
rates and high CAPE values beneath moderately strong northwest
mid-level flow. Scattered thunderstorms are expected to develop
along/east of the Blue Ridge and spread eastward across parts of
PA/VA/NJ/DE through the late afternoon and evening. Parameters
remain favorable for downburst winds in these clusters of storms.

...PA/NY into southern New England...
A weak shortwave trough and associated mid level speed max is
rotating southeastward out of Ontario/Quebec into the northeast US.
Ample low-level moisture and pockets of moderate CAPE will result in
widely scattered afternoon thunderstorm development from northern PA
into central NY. These storms will spread southeastward into
southern New England by early evening. The strongest cells will
pose a risk of damaging wind gusts.

..IL/IN...
A remnant MCV from overnight convection is analyzed over eastern IA,
with a surface boundary extending eastward just south of CHI. The
air mass to the south of the boundary across IL will become very
unstable by mid-afternoon, leading to scattered thunderstorms.
Favorable thermodynamic parameters suggest a risk of damaging winds
as these storms organize and track into IN by evening.

...KS/MO...
An ongoing cluster of strong/severe storms is affecting eastern KS.
Given the moist and unstable air mass to the east and sufficient
mesoscale organization, it is probable that this cluster will
persist into the afternoon. Storms will track into western MO with
a continued risk of locally damaging wind gusts.

...KS/OK/AR...
In the wake of the aforementioned cluster of storms, new development
is likely later this afternoon along the remnant outflow boundary
across southern KS and northern OK. High CAPE values to the south
of the boundary will promote the ENH risk of damaging winds and some
hail as storms build southeastward across central/eastern OK and
into western AR this evening.

...TX Panhandle...
A weak surface boundary will be the focus for scattered late
afternoon thunderstorms over the southern/eastern TX Panhandle. The
strongest cells may produce damaging wind gusts and large hail for a
few hours.

...Northeast CO...
Southerly low level winds will maintain dewpoints in at least the
40s over parts of eastern CO this afternoon despite strong
heating/mixing. This will be sufficient to allow scattered
thunderstorms to form along the foothills and DCVZ. A few severe
cells are possible with large hail being the main risk.

...MN/SD...
Similar to yesterday, a few afternoon and early evening
thunderstorms are expected to develop ahead of a weak shortwave
trough. The strongest cells might produce large hail or gusty
winds.

..Hart/Weinman.. 07/04/2026


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SPC Jul 4, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 AM CDT Sat Jul 04 2026

Valid 041300Z - 051200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE MID-ATLANTIC AS WELL AS ACROSS PORTIONS OF SOUTHERN KANSAS
AND NORTHERN OKLAHOMA...

...SUMMARY...
Clusters of storms will move across parts of the Allegheny Plateau
into the Mid-Atlantic, with potential for widespread damaging wind
gusts. Additional severe thunderstorms are expected across the Great
Plains this afternoon and evening, posing a risk for severe wind
gusts and large hail.

...Upper OH Valley into the Mid-Atlantic/southern New England...
A belt of moderate mid-level westerly flow aloft currently extends
across the OH Valley and Mid-Atlantic States, situated between the
upper troughing over eastern Canada and higher heights over the
southeast CONUS. A modest vorticity maximum appears to be moving
within these westerlies across Lower MI, downstream of two more
prominent, convectively augmented vorticity maxima across IA and KS.
There also appears to be a very modest shortwave trough moving over
the KY vicinity, evidenced by a subtle shift in the mid-level winds
across the region. Both of these features are expected to continue
eastward today, progressing into a very warm, moist, and unstable
airmass across the Upper OH Valley and Mid-Atlantic by the early
afternoon.

Interaction between the modest ascent associated with these features
and the unstable airmass forecast to be in place will support
thunderstorm development. This development is expected first over
the Blue Ridge Mountains/Shenandoah Valley vicinity during the early
afternoon (likely supported by the modest KY shortwave trough)
before then progressing northeastward through northern VA, DC,
central MD, DE, and southern NJ. Weak deep-layer shear amid a deeply
mixed airmass (with afternoon temperatures in the upper 90s/low
100s) will support outflow-dominant storm structures, and strong
cold pools capable of widespread damaging wind gusts. An isolated
gust or two around 70-75 mph is possible. A similar convective
evolution is anticipated farther north (from the Allegheny Plateau
through the northern Mid-Atlantic and southern New England) later in
the afternoon as the Lower MI vorticity maximum moves through the
region. Damaging gusts will be the primary risk here as well, with
slightly less coverage and magnitude than farther south.

...Central/Southern Plains...
Outflow associated with a decaying convective cluster over
western/central KS currently arcs from southeast CO across far
southwest KS into central KS. This cluster is forecast to continue
weakening as it gradually moves east-southeastward, with its
associated outflow likely extending from east-central KS back
southwestward across south-central KS by this afternoon. Airmass
destabilization is expected by the mid to late afternoon amid strong
heating, steep mid-level lapse rates, and ample low-level moisture.
Moisture convergence along this boundary within this convectively
uninhibited airmass will result in additional thunderstorms. Given
the strong buoyancy and moderate deep-layer vertical shear in place,
a few supercells are possible early in the convective cycle. Large
to isolated very large hail as well as strong downbursts are
possible with any supercells. A tornado or two could also occur,
particularly with sufficient residence time along the boundary.
Outflow-dominant storm structures will likely result in one or more
forward-propagating convective clusters throughout the evening.

Widely scattered thunderstorm development is anticipated within the
moist upslope flow over the central High Plains, with at least some
potential for the development of a convective line that then
progresses into western NE, northeastern CO, and northwestern KS.

Widely scattered thunderstorm development is also expected along the
dryline extending from the central/western OK Panhandle
southwestward across the TX Panhandle and into far east-central NM.
Weak vertical shear will likely prevent sustained updraft
organization, but a few storms could briefly be robust enough to
produce strong updrafts/downdrafts and resulting damaging gusts.

...Lower MO Valley into the Lower/Central OH Valley...
Scattered to numerous thunderstorms are expected this afternoon as a
pair of vorticity maxima, one associated with the convection over KS
and the other from overnight storms across IA, progress eastward
into the moist and diurnally destabilized airmass over the region.
Vertical shear across the region will be modest, limiting updraft
organization and promoting an outflow-dominant storm mode. Even so,
some cold pool amalgamation is possible, with the resultant
forward-propagating clusters capable of damaging gusts.

..Mosier/Dean.. 07/04/2026


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SPC Jul 4, 2026 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Sat Jul 04 2026

Valid 041200Z - 051200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
MID-ATLANTIC...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE CENTRAL/SOUTHERN PLAINS...

...SUMMARY...
Clusters of storms will move across parts of the Allegheny Plateau
into Mid Atlantic, with potential for widespread damaging wind.
Additional thunderstorms are expected across the Great Plains
Saturday afternoon and evening, posing a risk for damaging wind
gusts. Large hail is also possible across the Great Plains.

...Synopsis...
Height rises will continue across the western US, with more zonal
flow across the central US and upper-level troughing across the
Northeast and Quebec/Ontario. A modest belt of westerly flow around
30-40 kts will move through the trough in the
Northeast/Mid-Atlantic. A compact shortwave trough with enhanced
westerly flow will move through the flow across the Central Plains.

...Eastern Ohio Valley into the Mid-Atlantic...
Activity will likely be ongoing across some portion of northern PA
into northern NJ this morning. This will likely contribute to
lingering cloud cover and more muted daytime heating/recovery with
northern extent. South of the morning precipitation, strong daytime
heating and warming is expected, with temperatures climbing into the
90s to 100s F. A plume of steep mid-level lapse rates is already in
place across the region from WV into VA/MD/NJ. With daytime heating,
low-level lapse rates are expected to increase with moderate to
strong instability by the afternoon. Deep layer shear profiles will
be generally weak, with better shear to the north. Nonetheless,
several thunderstorm clusters are expected to develop across the
Blue Ridge Mountains/Shenandoah Valley moving north and eastward
though the afternoon. These will have the potential to produce
widespread damaging wind, especially if clusters can grow upscale
and develop strong cold pools.

Additional clusters are likely in the wake of morning convection
further north. Instability will be less, but sufficient deep layer
shear may support one or more clusters capable of damaging wind.

...Central/Southern Plains...
Evolution of thunderstorms across the central/southern Plains will
be dependent on evolution of morning convection across northern
Kansas. One or more MCVs may develop and drift south and eastward,
which will have impacts on the exact region that thunderstorms
redevelop by the afternoon. Guidance suggests that the corridor of
highest probability of development will be across southern Kansas
into northern Oklahoma. Within this region, widely scattered
thunderstorm activity is expected to develop by the afternoon, with
initial supercells capable of large to very large hail and perhaps a
tornado. These will eventually cluster and grow upscale, with a
likely MCS moving south into Oklahoma by the evening and an increase
in damaging wind potential.

More isolated supercell development is expected from the OK/TX
Panhandles northward into eastern CO/western KS/western NE. Deeply
mixed profiles and sufficient deep layer shear should support
potential for both large hail and damaging wind.

...Midwest into the lower Missouri Valley and western/central Ohio
Valley...
There is less confidence in evolution of afternoon thunderstorms
into the Missouri Valley and western/central Ohio Valley. Moderate
to strong instability will be in place with generally weak flow/deep
layer shear. Guidance suggests that several clusters of
thunderstorms may develop and spread eastward with damaging
wind/downburst potential. This will likely be focused in more
mesoscale corridors where residual outflow resides.

..Thornton/Moore.. 07/04/2026


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SPC Jul 4, 2026 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 PM CDT Fri Jul 03 2026

Valid 040100Z - 041200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
SOUTHEASTERN NEBRASKA INTO WESTERN IOWA...

...SUMMARY...
Scattered damaging gusts will continue across portions of the Mid
Atlantic and the central/northern Plains. More isolated to scattered
severe storms will also continue across portions of the High Plains
to the northern Rockies.

...Discussion...
Several clusters of widely scattered thunderstorms in many different
regimes are ongoing across portions of the central and northern
Plains into the Midwest and across the Mid-Atlantic. The greatest
threat through the remainder of the evening will be for damaging
wind, with a few instances of large hail and perhaps a tornado from
the Plains to the Midwest.

Across the central/northern Plains, activity is mainly tied to lee
troughing and broad ascent from the mid-level shortwave trough. A
few embedded supercells will pose potential for large hail through
the evening but the main threat is shifting to become damaging wind,
with several clusters attempting to grow upscale. The more focused
corridor of severe wind threat through the evening will likely
extend from southeastern Nebraska into northern Kansas, where a more
robust line has developed amid a strongly unstable air mass. Deep
layer shear decreases with southward extent into Kansas, however,
storms may be driven by cold pool dynamics south and eastward
through the evening.

Across portions of southern South Dakota, western Nebraska, and
eastern Colorado, a few more discrete supercell clusters are
ongoing. This region will be where the greatest short term risk will
be for large to very large hail, particularly across western
Nebraska into southwestern South Dakota.

Across portions of the Midwest into the Great Lakes, a cluster of
storms is moving across northern Illinois towards the Chicago Metro.
This line is tracking along a MLCAPE gradient that extends across
northern Illinois into northern Indiana/southern Michigan. Storms
will likely advance eastward along this gradient through the
evening, with potential for damaging winds.

Another robust line is moving eastward through New York City and
northern New Jersey. This has produced a swath of measured severe
wind and continues eastward towards the coast.

..Thornton.. 07/04/2026


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