- Thread starter
- Moderator
- #81
Discussion:
ACUS03 KWNS 200731
SWODY3
SPC AC 200730
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 AM CDT Sun Mar 20 2022
Valid 221200Z - 231200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF
SOUTHERN LOUISIANA INTO SOUTHERN MISSISSIPPI...
...SUMMARY...
A substantial severe weather event -- including potential for
significant tornadoes -- remains evident over the Lower Mississippi
Valley/central Gulf Coast region Tuesday.
...Synopsis...
A upper trough and expansive area of highly amplified cyclonic flow
will shift gradually eastward across the central U.S. Tuesday, as a
closed low likely evolves over the Mid Missouri Valley area with
time.
At the surface, a low is forecast to move across the Missouri
vicinity through the day, with a trailing cold front forecast to
reach the Mississippi Delta region during the afternoon. Late in
the period, the low should reside over the Illinois vicinity, with
the cold front extend southward across Kentucky/Tennessee/Alabama to
the Florida Panhandle.
...Lower Mississippi/central Gulf Coast States...
A regional severe-weather outbreak -- including potential for
several tornadoes (a few potentially significant) remains evident
for Tuesday. Severe storms -- including tornado risk -- will likely
be ongoing at the start of the period across the Sabine River Valley
area of east Texas/western Louisiana, as a surface cold front moves
steadily eastward.
As southerly flow ahead of the front continues to advect high
theta-e air northward from the Gulf, limited heating will allow
destabilization to occur through the morning and into the afternoon.
At this time, it appears that in addition to storms occurring ahead
of the advancing front, pre-frontal cellular convection will also
evolve through late morning/afternoon. With strong low-level
southerly flow (50 to 70 kt at 850mb) in place, and 70 to 90 kt
mid-level westerlies overspreading the region, shear very favorable
for strong updraft rotation and low-level mesocyclones will exist.
As such, potential for strong tornadoes will exist with the evolving
supercell storms ahead of the front. Additionally, tornadoes (along
with damaging winds and hail) will be likely with storms shifting
eastward in tandem with the cold front.
Into the evening and overnight, severe risk -- including potential
for tornadoes and damaging winds -- will continue. While
diminishing somewhat later in the period, threat will likely spread
across southern Alabama and into the Florida Panhandle.
..Goss.. 03/20/2022
Last edited:
