Cool low-level air
generated by the mesoscale convective complex to the north last night gradually
infiltrated into Tulsa overnight, leading to a low of 61F. A line of heavy showers
and thunderstorms produced 1.03” of rain early this morning, though winds were
surprisingly not that strong, perhaps due to the low-level inversion with the low-level
cool air not having scoured out yet. It then dried out but stayed cloudy
through early afternoon, but then it warmed up quickly to 82F with some
clearing. A quick storm this evening brought another 0.04” of rain (total of
1.07”) and a maximum wind of at least 26 kt. Southerly winds will continue
tonight, and combined with high humidity and low-level clouds re-forming, will
lead to not much radiational cooling. Southerly winds will continue tomorrow,
and low-level clouds will prevent a rapid warmup again, though some breaks in
the clouds allowing for some daytime heating and some mixing down of stronger winds
from aloft to the surface is still expected.
Then comes the dramatic finale of the tournament and the whole
WxChallenge season. The Storm Prediction Center puts Tulsa in an enhanced risk
of severe thunderstorms, with all hazards (tornadoes, strong winds, and hail)
possible. Supercells and/or broken lines of storms are already expected to
initiate along a subtle low-level convergence zone/secondary dry line to the
west of Tulsa (but east of the main dry line), over central Oklahoma, by late
tomorrow morning, but they will be the strongest tomorrow evening after peak
daytime instability. Tomorrow evening, the storms will congeal into a slightly
broken or complete line of strong thunderstorms that will move very slowly
eastward, due to the individual storms moving mostly northeastward almost
parallel to the dry line orientation. This slow movement will lead to a
training of thunderstorms and therefore likely a prolonged period of heavy rain
and very large rainfall amounts toward the end of the period (Sunday 06z) in
Tulsa. It is a tricky call how much of the rain falls before 06z vs after 06z,
as the heavy thunderstorms will likely still be ongoing at 06z. A burst of strong
winds is expected along the leading edge of the storms tomorrow evening, but
how strong they will be depends on if KTUL gets into the core of severe thunderstorms
or even a tornado. It will also cool down quickly as the storms arrive due to
rapid evaporational cooling with heavy rain, leading to a low at the end
(Sunday 06z).
