SPC AC 101712
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1212 PM CDT Mon May 10 2021
Valid 111200Z - 121200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY AND
Isolated strong to severe storms may occur Tuesday across parts of
the southern Plains into the lower Mississippi Valley and Southeast.
Large hail and damaging wind gusts should be the main threats.
Shortwave trough currently moving through the northern Great Basin
is forecast to continue southeastward into the Four Corners region
tonight before then moving more eastward across the central High
Plains/central Plains on Tuesday. Another shortwave trough is
currently moving east-northeastward across the Baja Peninsula. This
shortwave is expected to continue moving eastward across northern
Mexico and into the southern Plains and Lower MS Valley on Tuesday.
A relatively moist air mass will precede these shortwaves across the
southern Plains and Lower MS Valley. A stalled frontal boundary will
likely extend from southern MS/AL west-southwestward through the TX
Coast Plains into south TX, and then northwestward across northwest
Mexico. Some northward movement of this boundary is anticipated
through Tuesday afternoon before building high pressure over the
central Plains and mid/upper MS Valley encourages a southward surge
Tuesday evening through early Wednesday.
...Southern Plains into the Lower MS Valley and Southeast...
Showers and thunderstorms will likely be ongoing across portions of
the Lower MS Valley early Tuesday morning. Thunderstorm coverage is
expected to increase throughout the morning as ascent attendant to
the Baja shortwave trough mentioned in the synopsis spreads across
the southern Plains and Lower MS Valley. Warm-air advection
associated with strengthening low-level southerly flow across the
frontal boundary will also aid in storm development.
Widespread thunderstorm activity is anticipated across much
central/east TX and LA by early Tuesday afternoon, which will then
spread eastward throughout the remainder of the period. Moderate
vertical shear and buoyancy suggest a few embedded strong to severe
storms are possible. Majority of these storms will be north of the
front, indicating hail should be the primary threat. However, given
the shallow nature of the low-level stable layer, a few stronger
gusts are also possible. Additionally, northward motion of the warm
front could result in interaction between ongoing storms and this
frontal zone, particularly from east TX across central LA and into
central/southern MS. This interaction may result in a corridor of
modestly higher severe potential. Even so, mesoscale nature of this
interaction precluding introducing any higher severe probabilities
with this outlook.
A clustered/multicell storm mode is anticipated with most of the
activity across the southern Plains, Lower MS Valley, and Southeast.
The only exception is over southwest TX, where a triple point may
develop at the intersection of the effective warm front and dryline.
Convective initiation may occur as a result of convergence along
these boundaries, resulting in more discrete storms. Environment
supports a threat for large hail and damaging wind gusts if storms
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NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z