
Mesoscale Discussion 0354
NWS Storm Prediction Center Norman OK
0110 PM CDT Sun Apr 12 2020
Areas affected...Eastern Oklahoma and northeast Texas
Concerning...Severe potential...Watch possible
Valid 121810Z - 121945Z
Probability of Watch Issuance...60 percent
SUMMARY...Storm development is expected in the next 1 to 2 hours. A
watch is possible.
DISCUSSION...The airmass across northeast Texas and southern
Oklahoma has destabilized in the last 1 to 2 hours in the wake of a
morning MCS. MLCAPE has increased to 750 to 1250 J/kg per SPC
mesoanalysis. Some additional destabilization is expected in the
next hour or so before storm coverage quickly expands in the next 1
to 2 hours ahead of the approaching upper trough. Storm intensity
will likely be somewhat muted due to airmass contamination from the
earlier convection, but some strong to severe storms are possible.
A cold front is moving quickly across western Oklahoma and may be
the trigger for a few storms, but the fast speed may cut off
updrafts from the more unstable airmass before they can become
better rooted along the cold front. Therefore, the better threat for
strong to severe storms will likely be with storms that form ahead
of this front in eastern Oklahoma and northwest Texas. Boundary
layer cumulus have started to form in this area and SPC mesoanalysis
indicates CINH is mostly eroded indicating storm development is
likely imminent.
The primary threat from these storms will initially be large hail
and damaging winds. There is considerable low-level turning in the
TLX VWP, but low-level flow is quite weak (Less than 20 kts) which
will be a limiting factor to more than a brief weak tornado.
However, the low-level flow is expected to increase to 35-40 knots
after 22Z in southeast OK/NE TX which may lead to a greater tornado
threat early this evening in that region.
A watch may be needed, but it is unclear if storm intensity will be
strong enough to warrant a watch, especially prior to the increasing
low-level flow.
..Bentley.. 04/12/2020
...Please see
www.spc.noaa.gov for graphic product...
ATTN...WFO...LZK...SHV...TSA...FWD...OUN...
Winter time post are almost exclusively focused on the DFW area.