- Day Three
acus02 kwns 160523
Storm Prediction Center ac 160522
Day 2 convective outlook
National Weather Service Storm Prediction Center Norman OK
1122 PM CST Fri Feb 15 2019
Valid 171200z - 181200z
..no severe thunderstorm areas forecast...
the risk of severe thunderstorms appears negligible across the U.S.
Sunday through Sunday night.
Models continue to indicate that large-scale ridging and troughing,
evolving within the mid-latitude westerlies across the eastern
Pacific into western North America, will take on an increasingly
positive-tilt orientation through this period. Short wave
developments within this regime appear a little more uncertain, but
at least one significant perturbation is forecast to dig into the
base of the larger-scale troughing, across California, before
turning eastward across the southern Great Basin and southwest by
At the same time, downstream short wave ridging may build into
portions of the southeast, to the north of an increasingly prominent
subtropical high becoming centered over the Bahamas and Caribbean
vicinity. And a weak lower/mid tropospheric cyclone, initially over
the middle/lower Missouri and middle Mississippi Valley region, is
forecast to undergo shearing and deformation while accelerating
northeastward within an increasingly confluent regime to the north
of the Ohio River.
In the wake of the lead perturbation, an initially quasi-stationary
frontal zone may return southward through much of the remainder of
the Gulf Coast states, and southeast of the southern Appalachians.
As it does, a southerly return flow appears likely to persist and
continue to moisten above the shallower leading edge of the cold
air. This may contribute to sufficient elevated destabilization to
support scattered weak thunderstorm activity by Sunday night, if not
earlier. Highest probabilities for thunderstorms still appear in a
corridor east-northeast of the lower Mississippi Valley through the
southern Appalachians vicinity, near the northwestern periphery of
the mid-level subtropical ridging.
Otherwise, weak destabilization beneath very cold mid-level air is
again possible Sunday near the central California coast, and could
provide support for isolated to widely scattered weak thunderstorms.
Potential for destabilization supportive of convection capable of
producing lightning remains more unclear inland of the coast, into
the lower Colorado valley and southern Great Basin.
..maximum risk by hazard...
Tornado: <2% - none
wind: <5% - none
hail: <5% - none