ACUS48 KWNS 020829
SWOD48
SPC AC 020828
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0328 AM CDT Sun Aug 02 2026
Valid 051200Z - 101200Z
...DISCUSSION...
...Day 4/Wednesday...
Broad troughing will exist from Hudson Bay into the north-central
U.S. with a belt of enhanced, cyclonic flow from the northern
Rockies through northern and central Plains into the upper Great
Lakes. At the surface, a front will advance through the upper Great
Lakes with the western extension of the boundary settling more
slowly south through the central into southern High Plains.
Thunderstorms may be ongoing at 12Z across portions of the mid MO
Valley with lingering clouds and convective outflow potentially
modulating the location of the effective surface front and the
degree of instability ahead of it. The models suggest an area from
eastern KS into MO as being the most probable location for at least
isolated severe storms during the afternoon and evening hours. The
extent of the threat will likely be dependent on mesoscale details
yet to be known. As such, no area will be delineated in this
forecast.
Other areas of isolated severe storm potential will be in the
central High Plains and southeast AZ.
...Days 5 and 6/ Thursday and Friday...
A slight eastward shift of the mean trough position is forecast on
Thursday with some model signal for an embedded short-wave trough to
move through the Great Lakes. At the surface, there is some
suggestion that a weak front or wind shift will move into the
northern Mid-Atlantic during the afternoon with the trailing
extension of that boundary stretching through the mid MS Valley into
the southern High Plains. Ahead of that boundary, widespread 70+ F
dewpoints are expected from New England into the Mid-Atlantic and
Carolinas, leading to moderate to potentially strong instability.
The greatest potential for a few severe storms appears to be across
the Mid-Atlantic Thursday afternoon where the moderate instability
will coincide with a belt of 30-40 kt mid-level flow.
Some severe weather threat may also develop in the Ozark Plateau and
AZ Thursday afternoon and evening.
On Friday, the above-mentioned Great Lakes short-wave trough is
expected to shear northeast across southern ON with 30-40 kt of
mid-level flow prevailing over the Northeast. The surface pattern is
somewhat disorganized with some semblance of a trough from southern
New England through the Mid-Atlantic coastal region. Moderate to
strong instability may again develop ahead of that feature,
supporting the potential for some severe weather threat during the
afternoon and early evening hours. However, the strongest vertical
shear is forecast to remain to the north of the stronger
instability, leading to uncertainty in the magnitude of the severe
threat.
...Days 7 and 8/Saturday and Sunday...
The various 00Z ensemble mean solutions indicate a slight eastward
shift of an upper low near Hudson Bay with low-amplitude troughing
and strengthening mid-level flow moving into the Northeast.
Southerly low-level winds within the western periphery of a surface
high positioned off the Atlantic Coast will maintain a moist and
unstable air mass beneath the strengthening winds aloft. As such,
some severe weather threat is expected to persist from the
Mid-Atlantic into New England this period.
Elsewhere, there is some model signal for a surface front to move
into the Midwest, where some severe weather potential may exist.
..Mead.. 08/02/2026
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--- scorpsmtpd
* Origin: capitolcityonline.net * KY, USA (1:2320/107)