RSS Mesoscale Discussions from Storm Prediction Center
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0232 AM CDT Fri Jul 03 2026
Valid 051200Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON
INTO EVENING ACROSS THE MID ATLANTIC...
...SUMMARY...
Developing thunderstorm clusters may pose a risk for damaging wind
gusts across parts of the Mid Atlantic, and perhaps parts of the
southern Great Plains, Sunday afternoon and evening.
...Discussion...
The stronger mid-latitude westerlies likely will remain confined to
the higher latitudes through this period. Within this regime, one
initially notable short wave trough is forecast to gradually merge
into a significant mid-level low digging through the Labrador Sea,
as it accelerates away from the Canadian Maritimes and northern New
England. Upstream, mid-level troughing may gradually consolidate
across and east of the Canadian Prairies, and support modest surface
cyclogenesis across northern Saskatchewan and Manitoba. However, it
currently appears that stronger forcing for ascent, and potential
for severe thunderstorm development, will remain focused to the
north of the international border.
To the south of this perturbation, models suggest that mid-level
ridging, across the eastern Great Basin into north central Great
Plains at the outset of the period, will expand eastward across the
middle Missouri Valley toward upper Mississippi Valley Sunday
through Sunday night. Downstream, weak troughing, with embedded
convectively generated perturbations, will probably continue to
overspread the middle Mississippi and Ohio Valleys.
The focus for renewed thunderstorm development east of the southern
Great Plains into the Ohio Valley, Cumberland and Allegheny Plateau
remains unclear and will be considerably influenced by
mesoscale/sub-synoptic developments with low predictability at this
time frame. In general though, while at least pockets of large
potential instability may conditionally support some risk for storms
with potential to produce localized strong downbursts and gusty
winds along outflows, weak shear will probably limit the potential
for sustained organizing clusters. As such, the risk for severe
winds may not be completely negligible, but it is not clear that it
will reach the 5 percent threshold for an areal outlook.
...Mid Atlantic...
There does appear a general consensus in model output that a
low-level baroclinic zone may remain fairly well defined to the
north through northeast of a surface low developing to the lee of
the Blue Ridge by late Sunday afternoon. Near or just south of a
residual belt of convectively augmented westerly
lower/mid-tropospheric flow, the environment could become conducive
to organizing thunderstorm development with potential to produce
damaging wind gusts into Sunday evening.
...Raton Mesa/ridge into Texas South Plains...
A bit less certain, guidance suggests that it is possible that a
mid-level perturbation crossing the southern Rockies by Sunday
evening could provide a support for another developing cluster of
storms along a zone of differential surface heating. Moisture
within the strengthening baroclinic zone may provide support for
sizable mixed-layer CAPE, in the presence of modest shear due to
veering of wind fields with height, to support organization
accompanied by a period of strong to severe wind gusts into/through
Sunday evening.
..Kerr.. 07/03/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0402 AM CDT Fri Jul 03 2026
Valid 061200Z - 111200Z
...DISCUSSION...
Medium-range guidance suggests that a modest mid-level ridge, along
an axis from the eastern Great Basin into the Upper Midwest by early
next week, may gradually become suppressed by a low-amplitude short
wave trough emerging from the Great Basin by the middle of next
week. It appears that this will occur as a much more substantive
trough and embedded low, within the stronger westerlies confined to
the higher latitudes, progress inland across British Columbia and
the Canadian Rockies. This could be accompanied by some potential
for organized severe thunderstorm development across parts of
eastern Montana into the Dakotas by next Tuesday and/or Wednesday,
but enough spread persists within latest model output to preclude 15
percent or greater severe probabilities at this time.
A preceding trough within the stronger westerlies is forecast to
slowly progress east of the Canadian Prairies through Hudson Bay,
Ontario, Quebec and the remainder of the eastern Canadian Provinces
by late next week. It is possible that a corridor of boundary-layer
moistening and destabilization ahead of an associated cold front
could support increasing risk for thunderstorms across parts of the
lower Great Lakes through New England by next Thursday into Friday.
However, the extent of this potential, and the degree to which it
could pose a risk for damaging wind gusts remains uncertain at this
time.
Otherwise, severe potential in lower-latitudes, if any, will likely
generally be associated with sub-synoptic developments yet to evolve
and of rather low predictability at this time range.
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