Scientific Forecaster Discussion
fxus64 koun 221055
Area forecast discussion
National Weather Service Norman OK
555 am CDT Tue may 22 2018
12z taf discussion.
although some fog still appears possible at most of the taf sites this
morning, there continues to be no low stratus developing at this
time. Will therefore remove any IFR category ceilings with the 12z
issuance. Have maintained some 4 to 5 mile visibilities,
otherwise expect VFR conditions through the morning and the
remainder of this forecast. Winds will remain below 12kts other
than a few gusts at wwr this afternoon.
Previous discussion... /issued 220 am CDT Tue may 22 2018/
the large scale pattern continues to be dominated by positive
mid-level height anomalies across the country and is more
reminiscent of mid June than mid-late may. The exception is in the
southwest where a closed low resides early this morning centered
near Death Valley. Ascent on its eastern edge coupled with terrain
effects along the Central Mountain chain in New Mexico and
meridional flow enhancing moisture flux into this area will once
again lead to decent coverage of convection to our west this
afternoon. Convectively-driven cold pools may help organize
convection some over the High Plains but storms should diminish
during the evening as surface based instability wanes. We have
removed precipitation chances from far western sections of the
Further southeast, most of the diurnally driven isolated
convection today occurred in the ouachitas. Coverage today could
be more expansive and develop further west into the southeast
portion of the forecast area as weak DPVA associated with closed
upper low along the Texas Gulf Coast influences the area. Weak
mid-level lapse rates and very little wind aloft will result in
short lived single cells with very little movement. There could be
a brief gusty wind threat upon collapse of individual cells, but
severe weather potential is low.
By Wednesday, the closed mid-upper low will have moved into the
northern rockies and convective initation across the High Plains
should be less extensive and centered further east. Organization of
convection to our west is unlikely given weak winds aloft, but cold
pools could move into our area and generate some convection across
our far western section before diurnal heating and resulting
instability decrease during the evening. We have low probabilities
to cover this possibility from late afternoon through evening.
Meanwhile, a diurnal uptick in isolated convection is expected
across eastern section of the area once again given the presence
of a weak shear axis/DPVA oriented north to south across eastern
Oklahoma and a moist environment that becomes modestly unstable
with afternoon heating.
The above should repeat itself for the next several days as Gulf
Coast low gradually drifts northeastward through the weekend. The
potential for High Plains convection to drift into the northwest
will decrease for the latter half of the week and into the weekend
until another deep closed low approaches early next week.
No widespread or significant precipitation events are expected the
next several days and activity should have a strong diurnal maxima
with regards to coverage and intensity. Temperatures should
gradually warm through the week reaching 90 degrees or above by the
end of the week at most locations. Above normal temperatures will
continue through the weekend into early next week.
Preliminary point temps/pops...
Oklahoma City OK 86 66 86 66 / 0 10 10 10
Hobart OK 88 65 88 66 / 0 0 10 10
Wichita Falls Texas 88 66 88 67 / 0 0 10 0
gage OK 89 63 88 64 / 0 10 20 20
Ponca City OK 88 64 87 66 / 0 10 20 10
Durant OK 87 66 86 66 / 20 20 30 20