SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0213 AM CDT Tue Jun 28 2022
Valid 301200Z - 011200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THURSDAY ACROSS
PARTS OF NORTH CENTRAL KANSAS...EASTERN NEBRASKA...WESTERN AND
NORTHERN IOWA...SOUTHERN AND EASTERN MINNESOTA...CENTRAL AND
NORTHERN WISCONSIN AND UPPER MICHIGAN...
...SUMMARY...
Strong thunderstorms may impact a corridor from the central Great
Plains into the Upper Midwest and adjacent Great Lakes region
Thursday, posing at least some risk for severe weather.
...Synopsis...
Blocking may continue to become more prominent, with an increasingly
amplified split flow developing across the eastern Pacific into
western North America during this period. Downstream, a deep
mid-level low emanating from the Canadian Arctic latitudes is
forecast to continue to slowly dig near the southwestern shores of
Hudson Bay. As it does, mid-level heights may become suppressed to
its south, across parts of the northern Great Plains through the
Great Lakes region. Otherwise, there appears likely to be little
change to the persistent mid/upper ridging across much of the
central and southern tier of the United Sates.
In lower-levels, a developing surface low, emerging from the
southern Canadian Prairies on Wednesday, may progress across
northern Ontario, before perhaps deepening more substantively and
occluding across the southeastern Hudson Bay vicinity by late
Thursday night. A trailing cold front appears likely to advance
south of the international border through much of the upper Great
Lakes region and northern Great Plains. Along and east of
pre-frontal surface troughing, and around the western periphery of
low-level ridging centered over the southwestern Atlantic, a
seasonably moderate to strong low-level jet (30-40+ kt around 850
mb) may persist through much of the period across parts of the
southern and central Great Plains into the Upper Midwest and Great
Lakes region. Although a gradual moistening, aided by the
northeastward advection of monsoonal moisture, may continue along
much of this corridor, seasonably high boundary-layer moisture
content might remain confined to much of the Southeast, lower
Mississippi Valley and southeast Texas.
...Central Great Plains into upper Great Lakes...
Although the strongest deep-layer mean wind fields may begin to
shift across and northeast of the Great Lakes region, 30-50 kt flow
in the 850-500 mb layer may persist across the Upper Midwest into
Great Lakes region through much of the day. Farther south, the
stronger flow (on the order of 30 kt around 850 mb) will be confined
to the lower levels, east of the pre-frontal surface troughing into
the central/southern Great Plains. Given sufficient
destabilization, this regime will at least conditionally support
organized severe thunderstorm development.
Despite some continued moistening of the pre-frontal boundary layer,
guidance suggests that modification of mid-level lapse rates,
associated with the remnants of a plume of elevated mixed-layer air,
may only allow for the development of seasonably modest mixed-layer
CAPE on the order of 1000-2000 J/kg. Within the stronger deep-layer
mean flow, near and east-northeast of the upper Great Lakes, this
may be slowed or inhibited by early day cloud cover.
Still, this environment may support at least widely scattered strong
to severe thunderstorm development by late Thursday afternoon and
evening. This may include isolated supercells, and a couple of
evolving clusters of storms, which could pose a risk for mostly
severe wind and some hail.
..Kerr.. 06/28/2022
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