SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0148 PM CST Sun Mar 06 2022
Valid 062000Z - 071200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM
WEST-CENTRAL INTO NORTHERN ARKANSAS AND FAR SOUTHEAST MISSOURI...
...SUMMARY...
Severe thunderstorms are expected this afternoon through tonight in
a corridor from the ArkLaTex and Ozarks region into the Ohio Valley
and Tennessee Valley. This includes the risk for a few tornadoes,
some of which may be strong, and damaging winds, especially this
evening/overnight across parts of northern Arkansas and southern
Missouri.
...Discussion...
Have made the following changes to the previous convective outlook.
Otherwise, forecast thinking remains unchanged and no change was
made.
1a.) Adjusted the northern bound of the Enhanced Risk (30 wind and
10 sigtor) to the south by about 1 county tier to account for
observations and cold air that will likely remain entrenched across
southern MO.
1b.) Adjusted the 10 sigtor farther southwest to immediately
south/east of the Fort Smith vicinity. Forecast soundings and
recent HRRR guidance indicate the favorable area for a strong
tornado would also include more of parts of west-central AR.
2.) Extended the 5 wind probability farther east-northeast across
east-central OH for a low risk for marginally strong/locally severe
gusts this afternoon before this risk diminishes with diurnal
cooling.
3.) Carved severe probabilities farther south/southeast across OK
into MO to account for current surface observations and surface
front placement and its associated relationship with wind/tornado
hazard probabilities.
..Smith.. 03/06/2022
.PREV DISCUSSION... /ISSUED 1028 AM CST Sun Mar 06 2022/
...ArkLaTex into the Mid Mississippi Valley...
Evident on morning water vapor imagery, a deepening shortwave trough
and 90-100 kt 500 mb jet are forecast to eject northeastward out of
the Four Corners across the southern Plains today, reaching the
Ozarks and Ohio Valley later tonight. At the surface, a cold front
draped over the Mississippi and Ohio Valleys will move to the east,
as a wave cyclone travels along the front overnight. Low-level warm
advection is expected through much of the day ahead of the trough
across AR and LA. The initially subtle forcing for ascent will
intensify through the afternoon and evening, resulting in scattered
showers and eventual thunderstorm development as weak inhibition is
removed. While wind profiles are not forecast to be overly strong at
first, low-level hodograph curvature and gradually improving
buoyancy from the advection of 60+ F surface dewpoints may support a
few severe storms across the ArkLaTex as early as this afternoon.
The greater severe threat will likely evolve late this afternoon and
evening into the overnight hours as the approaching trough and
low-level jet intensify. Any remaining inhibition should quickly be
overcome, supporting numerous showers and thunderstorms by 00-02z.
50-60 knots of effective shear and large low-level hodographs will
support the potential for a few supercells or organized clusters
ahead of more linear development closer to the cold front. This
would support the risk for damaging wind gusts and a few tornadoes,
some of which may be strong across portions of northern AR and
southern MO. Storms should eventually congeal into a larger
cluster/QLCS as they track northeastward toward the Ohio valley.
...Ohio Valley...
As the primary shortwave and jet approach from the southwest, large
scale ascent should support the development of a thunderstorms along
the cold front overnight. Buoyancy will become increasingly scarce
with northeastward extent, but this may be somewhat offset by strong
dynamic lift and low-level warm advection. The strong wind profiles
will support an organized QLCS as it moves northeast near the
surface cyclone. A couple tornadoes and some damaging wind gusts
will be possible, though uncertainty is considerable on the north
and eastward extent of severe probabilities overnight.
...New England...
A fast moving shortwave trough moving out of southern Canada may
support a few strong/severe thunderstorms along a cold front this
afternoon crossing portions of upstate new York and New England.
Despite meager buoyancy ( CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/SLC44D
