spc ac 201645
day 2 convective outlook
nws storm prediction center norman ok
1045 am cst tue jan 20 2026
valid 211200z - 221200z
...no severe thunderstorm areas forecast...
...summary...
widely scattered weak thunderstorm activity is possible wednesday
into wednesday evening across parts of southeastern texas into the
lower mississippi valley.
...discussion...
while an initially prominent mid-level ridge, centered offshore of
the pacific northwest/british columbia coast into alaska, will
undergo more notable weakening through this period, models indicate
that large-scale downstream troughing will generally be maintained
across much of interior and eastern north america. it appears that
this will be reinforced by a strong short wave trough emerging from
the canadian arctic latitudes, before digging around the western
periphery of hudson bay, toward the central international border
area. this is forecast to be accompanied by modest cyclogenesis
across and northeast of the great lakes, and a more notable
reinforcing cold intrusion into the ohio and missouri valleys, in
the wake of a preceding one reaching the mid atlantic, northern gulf
coast states and texas gulf coastal plain by 12z wednesday
at the same time, it still appears that much of the southern tier of
the u.s. will continue to come under the increasing influence of
westerlies emanating from the southern mid- to subtropical latitudes
of the eastern pacific. within this regime, a notable developing
mid-level low is forecast to slowly dig toward the southern
california/northern baja coast, downstream of a building short wave
ridge over the mid-latitude eastern pacific. while forecast
soundings suggest that this may be preceded by an inland spreading
band of weak convection, associated with mid/high-level moisture
return from the lower latitude eastern pacific, the modest and
relatively compact mid-level cold core of the low is forecast to
remain offshore through this period. this will minimize the risk
for boundary-layer destabilization, and any appreciable potential
for convection capable of producing lightning, across and inland of
coastal areas.
downstream, lower/mid-tropospheric moisture return is likely to
continue across parts of southern/eastern texas into the lower
mississippi valley wednesday through wednesday night. although, in
lower levels, this will be off a still modifying western gulf
boundary layer, it appears that elevated inland moistening, beneath
the southern periphery of colder mid-level air slowly retreating to
somewhat higher latitudes, will contribute to weak elevated
destabilization. forecast soundings continue to suggest that this
may become sufficient to support convection capable of producing
lightning, mainly in a corridor from southeast texas
east-northeastward through the lower mississippi valley, aided by
forcing for ascent associated with one or two short wave
perturbations within the lingering cyclonic flow.
..kerr.. 01/20/2026
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note: the next day 2 outlook is scheduled by 0700z