SPC 1200Z Day 1 Outlook

Day 1 Outlook Image

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1154 PM CST Fri Nov 13 2020

Valid 141200Z - 151200Z


Severe thunderstorms associated with wind damage and perhaps a
tornado or two may occur across eastern Oklahoma and the Ozarks late
this afternoon and evening.

...Eastern Oklahoma/Northwest Arkansas/Southern and Central
Southwest mid-level flow will be in place today from the southern
Plains eastward into the Mississippi Valley ahead of the an
upper-level trough moving through the High Plains. At the surface, a
low will deepen across the central Plains as moisture advection
occurs in the southern Plains. The surface low will move eastward
into the lower Missouri Valley this afternoon with a cold front
advancing southeastward across the central Plains and southern High
Plains. Ahead of this front, surface dewpoints will increase into
the lower to mid 60s F from northeast Texas into eastern Oklahoma
and western Arkansas. In response, a pocket of moderate instability
is forecast to develop across eastern Oklahoma by late afternoon.
SBCAPE values are forecast to peak around 1500 J/kg.

Increasing low-level convergence just ahead of the front will likely
result in convective initiation along the northern end of the
stronger instability late this afternoon. Discrete cell formation
appears most likely during the one to two hours after initiation.
This will be the most probable time for supercell development.
Strong deep-layer shear, aided by the exit region of the mid-level
jet, and ample low-level shear should be favorable for an isolated
tornado threat with supercells. The tornado threat appears likely to
be greatest along the western edge of the low-level jet from
south-central Missouri southwestward into northwest Arkansas and far
eastern Oklahoma. Due to a band of focused large-scale ascent, a
squall-line is expected to organize and move east-southward across
the Ozarks extending south-southwestward into the Arklatex. This is
expected in the early to mid evening as the low-level jet markedly
strengthens. Wind damage will be the primary threat along the
leading edge of this line of strong to severe storms. The severe
threat could continue into parts of eastern Missouri and
east-central Arkansas late this evening.

..Squitieri/Broyles.. 11/14/2020

Read more
There’s more click here.

Comments are closed.