- Day Three
acus03 kwns 150758
Storm Prediction Center ac 150758
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0158 am 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.
Large-scale ridging and troughing evolving within the mid-latitude
westerlies across the eastern Pacific into western North America may
trend more positively tilted through this period. Within this
regime, a vigorous short wave trough, initially digging along the
Pacific coast to the east of the ridging, is forecast to gradually
turn inland through the base of the large-scale troughing, across
the southern Great Basin and southwest by early Monday.
At the same time, short wave ridging may build downstream, into and
through the southeast, to the north of an increasingly prominent
subtropical ridge becoming centered over the Bahamas. And a weak
lower/mid-tropospheric cyclone, initially over the lower
Missouri/middle Mississippi Valley vicinity, is forecast to undergo
shearing and deformation while accelerating northeastward within an
increasingly confluent regime to the north of the Ohio River. As it
does, an associated cold front may advance southward through much of
the remainder of the Gulf Coast states, and southeast of the
southern Appalachians into the South Atlantic Seaboard, before
Above the shallower leading edge of the advancing cold air, it does
appear that a southerly return flow will persist and continue to
moisten. Models suggest that this may contribute to sufficient
elevated destabilization to support scattered weak thunderstorm
activity by Sunday night, particularly in a corridor east-northeast
of the lower Mississippi Valley through the southern Appalachians
(near the northern periphery of the mid-level subtropical ridging).
Otherwise, destabilization beneath cold mid-level air may support
additional convection capable of producing lightning near central
and Southern California coastal areas Sunday. Potential for weak
thunderstorm development inland across the lower Colorado valley
into The Four Corners region late Sunday into Sunday night currently
remains more unclear.