Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0156 PM CST Wed Nov 13 2024

Valid 132000Z - 141200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
SOUTHERN LOUISIANA AND MISSISSIPPI...

...SUMMARY...
Isolated severe thunderstorms may still occur today across the Lower
Mississippi Valley, posing a risk for isolated severe wind gusts and
potentially a couple of tornadoes. Occasional severe winds may also
develop along parts of the coastal Pacific Northwest.

...20Z Update...
The previous forecast remains on track. Slight westward trimming of
severe probabilities were made to account for the eastward
progression of the surface trough. Otherwise, low-level WAA
preceding the surface trough, in tandem with vertically veering wind
profiles, may support stronger storms with occasional bouts of
low-level rotation. As such, a couple of damaging gusts or isolated
tornadoes remain possible into this evening. A brief tornado also
still cannot be ruled out over portions of coastal Pacific
Northwest.

..Squitieri.. 11/13/2024

.PREV DISCUSSION... /ISSUED 1033 AM CST Wed Nov 13 2024/

...Lower Mississippi Valley...
Have upgraded portions of southeast Louisiana and far southern
Mississippi for the possibility of a couple of tornadoes and
localized wind damage.

While multi-layer cloud cover has generally persisted, small pockets
of clearing/scattering have occurred within the warm sector with
several surface observations with temperatures near/just above 80 F.
Rich low-level moisture will continue to stream northward today,
while an upper trough over the Plains continues eastward towards the
Ohio Valley. Primary surface low and better forcing associated with
this upper trough will initially be well north of the
inland-advancing warm sector. However, scattered surface-based
thunderstorms should develop and become more common this afternoon
as the remnant/weak surface low off the Louisiana Coast moves slowly
inland. Low-level shear (through 1-3km AGL) should increase through
late afternoon into this evening, particularly in vicinity of the
surface low/triple point. A few supercells/clusters will pose
potential for damaging winds and possibly a couple of tornadoes.

...Coastal Pacific Northwest...
Associated with an eastward-moving upper-level trough, cold
mid-level temperatures (around -24 to -26C at 500 mb) and modestly
steepened mid-level lapse rates will yield weak instability today
across parts of the coastal Pacific Northwest (see 12Z UIL
sounding). Persistent large-scale ascent across this region will
support both low-topped cells and bands of convection moving
eastward through this afternoon and early evening. Given the
forecast strength of the low-level winds, some of this activity may
occasionally produce strong to severe wind gusts, and perhaps small
hail. Tornado potential remains unclear, as low-level flow will have
a tendency to veer more to southwesterly through the day, which
should limit 0-1 km SRH.