Scientific Forecaster Discussion
fxus64 ktsa 271707
Area forecast discussion
National Weather Service Tulsa OK
1207 PM CDT Sat may 27 2017
concerning taf sites ktul/krvs/kbvo/kmlc/kxna/kfyv/kfsm/krog.
Ongoing MVFR ceilings will continue to lift by mid afternoon.
Thunderstorms expected to develop in the vicinity of approaching
cold front and possibly ahead of dryline, likely during the 23-01z
time frame. Continue to cover most likely time frames for thunderstorms and rain
with tempo groups, including a mention of severe wind gust
potential. A second round of thunderstorms later in the
evening/early tomorrow morning is most likely to affect mlc/fsm,
which is covered with a prob30. Winds shift to a north to northwest direction
behind the cold front by tomorrow morning, with MVFR ceilings
prevailing through the end of the valid taf period.
Previous discussion... /issued 1118 am CDT Sat may 27 2017/
forecast is largely on track.
Early morning convection has produced a substantial reinforcement
to the cold frontal boundary which currently extends from far northwest
OK to along the Kansas OK border in NE OK. Short term solutions seem
somewhat aggressive in lifting this boundary northward this
afternoon and we tend to favor a more southern solution which
places a focus nearer NE OK. An additional area of concern will be
the dryline extending from the cold front southward through south
central OK by late afternoon. Both of these boundaries are likely
to serve as a focus for storm development later this afternoon.
The environment is extremely unstable with 35 to 50 kts of deep
layer shear overspreading the warm sector. Low level winds are
less impressive however the aforementioned cold front would be a
prime zone for enhanced low level shear especially given the level
of instability. Further south along the dryline convective
initiation is less certain however the idea of hot temps and deep
dryline circulation may well be enough to erode the cap. Initial
storm development within this zone could be a bit high based and
hrrr solutions offer impressive downburst wind signatures. By
early evening however any sustained supercell across southeast OK looks
to experience a period of enhanced low level shear and forecast
hodographs become increasingly concerning before the cold front
and/or combined outflow boundary from storms further north
overtake any cellular activity.
Regardless the exact evolution the atmosphere is capable of
significant severe weather this afternoon through the early
morning hours. Stay weather aware.