FXUS64 KTSA 211045
Area Forecast Discussion
National Weather Service Tulsa OK
545 AM CDT Tue Aug 21 2018
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
Main aviation concern is the potential for MVFR ceilings this
morning at the NW AR terminals and perhaps BVO as well. These
ceilings should lift late morning into early afternoon with VFR
conditions expected thereafter. VFR conditions will prevail at the
remaining terminals through the period. Toward sunrise Wednesday,
there is a nonzero chance of showers or thunderstorms mainly at
BVO, but those chances are well below mentionable levels. Chances
increase after 12Z Wednesday.
.PREV DISCUSSION... /Issued 403 AM CDT Tue Aug 21 2018/
The relatively cool August weather will persist for a couple more
days before summertime heat returns for the weekend into next
week. Mainly late night and morning shower and thunderstorm
chances will exist from late tonight through Friday morning as
upstream MCS activity attempts to push into mainly the northern
part of our area along the southern edge of the stronger mid level
flow. The resultant clouds will help hold temperatures down
through Thursday. By this weekend into next week, an upper ridge
takes hold, with hot and humid weather returning, although daytime
temperatures will still be somewhat modulated by the copious
amounts of rain that have fallen recently in many locations.
Stayed close to guidance temperatures the next couple days.
FXUS64 KOUN 211054
Area Forecast Discussion
National Weather Service Norman OK
554 AM CDT Tue Aug 21 2018
VFR conditions are expected through the period. A north
wind will become east and southeast this afternoon/night.
Mid and high clouds will increase across at least northern
Oklahoma this evening/night with widely scattered showers and a
thunderstorm across northwest Oklahoma after 4Z.
.PREV DISCUSSION... /issued 338 AM CDT Tue Aug 21 2018/
A mid and upper level ridge center over New Mexico, will build
eastward today and tonight. Meanwhile, surface winds will become
east to southeast across western Oklahoma today and the rest of
the area tonight. Upslope flow over eastern Colorado and a weak
upper air disturbance will result in scattered afternoon showers
and thunderstorms. Widely scattered showers and a few storms
should reach mainly northwest Oklahoma during the late evening
and overnight, but limited instability should reduce coverage
Afternoon and evening showers and storms are expected to develop
again Wednesday. Better coverage of showers and storms should
be across Kansas where the low to mid level flow will be
A trough is forecast to move across the northern Plains late
Thursday into Friday. This may result in widely scattered
showers and thunderstorms mainly across the northern third/half
Dry, breezy and hot weather is expected over the weekend/early
next week as the mid level ridge builds northward and eastward.
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 86 66 88 68 / 0 10 10 20
Hobart OK 92 69 91 72 / 0 10 10 10
Wichita Falls TX 94 69 93 74 / 0 0 10 0
Gage OK 87 65 86 68 / 0 40 40 40
Ponca City OK 86 66 79 64 / 0 40 50 60
Durant OK 91 68 91 71 / 0 0 10 0
FXUS64 KAMA 211131
Area Forecast Discussion
National Weather Service Amarillo TX
631 AM CDT Tue Aug 21 2018
12Z Issuance...VFR conditions unless storms hit GUY and DHT, then
cigs or vsby may be lower. If storms happen, it would hit DHT
starting after 00Z and at GUY after 02Z, but confidence is middle
of the road. Winds will be southerly and moving more southeasterly
after 00Z. If storms do happen, any outflows could change the wind
direction. Will monitor and update when more confidence is build.
.PREV DISCUSSION... /Issued 353 AM CDT Tue Aug 21 2018/
The northerly flow yesterday, that allowed for smoke from the
fires all the way up in CA/OR/WA to be transported across the
northern Rockies and then down the great plains, will become more
northwesterly today. The flow at the lower levels will become
more south to southeasterly today due to a lee surface low setting
up. This southerly flow should aid in the dispersal of the smoke
by late morning to early afternoon.
Northwest flow today will transition to more of a westerly flow
later in the evening and overnight as an upper level trough from
the northwest will help suppress the ridge off over the AZ/NM
area. Models continue to hang on to a shortwave that looks to move
across the northern Panhandles around 7pm this evening. This
could be a hit or miss scenario for the central and northern
Panhandles, as depending on the track of the shortwave and the
timing, it could impact the southern CO/KS area, and have limited
impact the the OK Panhandle, with litter to no impact in the TX
Panhandle. Deterministic models seem to favor the impacts the be
in the TX/OK Panhandle area, while the CAM's want to favor a more
northerly progression of the activity.
Some things to note for today, conditional instability ahead of
the main shortwave, ML CAPE ranges from 1000-2000 J/kg. Helicity
values are fairly decent given the southeasterly winds at the
surface and the westerly winds aloft. Storms could be strong to
severe with wind and hail being the primary threat, but wont rule
out a low end tornado threat. The LCL's are pretty high in the 5
to 6kft range. With a minimal cap later in the evening storms
should line out and be more elevated in nature, becoming more of
a wind threat.
Flow will be more westerly on Wednesday into Thursday, but monsoon
moisture will still be transported over the area, as well as the
potential for other shortwaves to move across. This will keep the
chances for storms going, mainly for the central and northern
Panhandles. Storms could be strong to possibly severe as well on
Wednesday afternoon and evening, with wind and hail being the
As the upper level trough slowly progresses across the northern
CONUS, the high will remain suppressed to the southeast TX area,
continuing the westerly flow across the Panhandles. As a result
showers and storms will be possible again on Thursday.
As we head into the end of the work week and the weekend, the
high that was suppressed to the southeast will strengthen across
the southern CONUS, due to the exit of the trough the northeast.
Still a little difficult to tell if we will be close enough to the
center of the high, to remain under mostly subsidence and stay
dry the entire time, but do expect that if the high shifts far
enough east, return moisture from the southwest will likely impact
the Panhandles, allowing for a better chance for precipitation in
the extended. As it stands now holding onto a dry pattern from
Something important to note, being on the back side of the high
will also transport warmer/hot temperatures to the area, the Palo
Duro Canyon floor is forecast to be right around 100 degrees
Thursday to the end of the forecast period. All other areas can
expect upper 90s to near 100 as well for the extended period.
06Z Issuance...VFR conditions expected but northern sites may see
storms after 00Z that may lower conditions. Winds are turning
clockwise from easterly to southerly with some gusts to 20kts.
Smoke causing low vsby should start clearing up by morning.