849
ACUS01 KWNS 131946
SWODY1
SPC AC 131944

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0244 PM CDT Sat Jul 13 2024

Valid 132000Z - 141200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE
NORTHERN HIGH PLAINS...

...SUMMARY...
Multiple clusters of strong to severe thunderstorms are possible
across portions of the Northern Plains into the Upper Mississippi
Valley through tonight.  Other more isolated strong storms are
possible in northern New England, and portions of Nevada.

...20z Update...

The previous outlook remains on track, and no changes are needed
with the 20z update.

For short term information on severe potential across portions of
NV/AZ/UT, as well as across the northern High Plains, see MCDs 1593
and 1594. Otherwise, see previous discussion below for more forecast
details.

..Leitman.. 07/13/2024

.PREV DISCUSSION... /ISSUED 1128 AM CDT Sat Jul 13 2024/

...Northern High Plains...
Relatively fast westerly mid-level flow is present today across the
northern Rockies/Plains.  Several weak shortwave troughs are
tracking across southern Canada and parts of MT/ND today, including
one with an associated cluster of thunderstorms over southwest SK.
Persistent east-southeasterly low level winds ahead of this system
across eastern MT will likely allow it to persist through the day
and intensify with afternoon heating.  A combination of supercells
and bowing structures are suggested by morning CAM guidance, with a
risk of large hail and damaging winds tracking across northeast MT
into western ND during the late afternoon and evening.  Given the
consistent signal in guidance for fast-moving storms, and the
favorable CAPE/shear environment, have upgraded parts of this
corridor to ENH risk.

...MN/WI and Vicinity...
Remnant MCS and associated MCV is currently located over southeast
MN.  This system will track southeastward across central/southern WI
through the afternoon, where strong daytime heating and dewpoints in
the upper 60s to lower 70s will yield strong instability.
Re-development of storms is possible, with a few severe/supercell
storms possible - capable of hail and damaging wind gusts.

Later this evening, thunderstorms are expected to intensify along a
weak cold front sagging into northeast ND and northern MN.  These
storms are depicted by most morning CAM solutions to organize into a
linear MCS and spread southeastward across much of MN and northern
WI overnight.  This scenario would pose a risk of damaging winds and
some hail in this area as well.

...Northern New England...
Scattered thunderstorms have begun to form this afternoon across
southern Quebec and parts of northern VT/NH/ME.  Relatively strong
westerly flow aloft and moderate CAPE values will promote a risk of
locally gusty/damaging winds in the stronger cells through the
afternoon.

...NV and Vicinity...
Similar to the last couple of days, ample mid-level moisture is
present today across parts of NV, western UT, and northwest AZ.  Hot
surface conditions and steep mid-level lapse rates will yield
widespread inverted-v profiles.  Model guidance suggests scattered
coverage of high-based thunderstorms, with sufficient winds aloft to
promote locally damaging wind gusts in the stronger downdrafts.

$$