Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0350 AM CDT Thu Jul 21 2022
Valid 241200Z - 291200Z
...DISCUSSION...
A shortwave trough should continue moving eastward from the Great
Lakes across the Northeast on Day 4/Sunday. A surface cold front
associated with this upper trough should likewise progress eastward
over parts of the Northeast, Mid-Atlantic, and OH Valley through
Sunday evening. Some severe threat may exist with thunderstorms that
can form along/ahead of the cold front. However, there is still a
fair amount of uncertainty with how unstable the warm sector will
become, and the coverage/placement of this potentially severe
convection. Will defer possible inclusion of a 15% severe area to a
later outlook, but at least low severe probabilities may be needed
from parts of the OH Valley into the Northeast on Sunday.
An upper trough/low should persist over parts of eastern Canada into
the Northeast/Great Lakes on Day 5/Monday. Any lingering severe
threat should be confined to portions of the eastern states ahead of
a cold front. Confidence in a corridor of greater severe potential
Monday afternoon/evening ahead of the front remains too low for a
15% severe delineation at this time. From Day 6/Tuesday onward, most
medium-range guidance suggests that an upper ridge that has been
persistently centered over much of the southern CONUS will be
suppressed by an upper trough forecast to develop southeastward from
central Canada across the north-central states. Some severe risk
associated with this feature may exist across portions of the
central CONUS from Day 6/Tuesday through Day 8/Thursday. But,
predictability regarding the amplitude and placement of the upper
trough, along with related surface features, remains limited at this
extended time frame.
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