16/12/2021
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1153 PM CST Wed Dec 15 2021
Valid 161200Z - 171200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE ARKLATEX INTO THE MID-MISSISSIPPI VALLEY...
...SUMMARY...
A marginal risk for gusty winds and hail with a couple of stronger
storms may evolve Thursday from parts of northeastern Texas across
the Arklatex into parts of the Mid-Mississippi Valley.
...Synopsis...
An upper-level trough and associated strong jet-streak will move
through the Great Lakes into southeast Canada through the day today.
Meanwhile, a second positively-tilted trough will cross the central
Rockies which will keep a broad area of cyclonic flow across much of
the central States. At the surface, an occluding, very strong
cyclone will mover northeast into northern Ontario with a trailing
cold front moving quickly eastward across the Great Lakes and
Northeast and only slowly advancing southeastward across portions of
the Mississippi Valley and into the Arklatex.
...Parts of Northeast Texas and southeast Oklahoma into the
Mid-Mississippi Valley...
At the beginning of the period, showers and occasional thunderstorms
are expected to be ongoing along and ahead of the surface front as
it moves slowly southeastward. This front will slow its progression
through the day and eventually start to retreat northward during the
late evening and into the overnight hours. Some modest surface
heating is possible ahead of the front with temperatures warming
into the low 70s. This may provide ample instability, when coupled
with veering and increasing flow with height, for a few stronger
storms. However, expect storm coverage and intensity to be low given
the lack of larger scale forcing and neutral to slightly rising
mid-level heights through the late afternoon/early evening.
Overnight, the low-level jet is expected to strengthen as the
western trough starts to move over the Plains. This will bring
increasing isentropic ascent and thunderstorm coverage across
eastern Texas/Oklahoma and western Arkansas, especially after 06Z.
Forecast soundings show ample elevated instability and shear for an
occasional stronger storm or two, but expect this activity to remain
mostly sub-severe.
..Bentley.. 12/16/2021