Area Forecast Discussion
Issued by NWS Oklahoma City, OK
FXUS64 KOUN 181153
Area Forecast Discussion
National Weather Service Norman OK
553 AM CST Wed Jan 18 2017
The January 18-19, 2017 12 UTC TAF discussion follows:
Patchy dense fog and low ceilings are impacting southern Oklahoma
and western north Texas this morning (KSPS/KLAW). Expect flight
conditions at these terminals to improve to MVFR by mid-morning.
Otherwise, a low confidence forecast through today. At the other
terminals, currently expect VFR ceilings through much of the
daytime hours with brief periods of MVFR ceilings possible--
especially across western Oklahoma (KCSM/KHBR).
By this evening into the overnight hours, deteriorating flight
conditions are expected at all terminals. Fog/mist, drizzle, and
low ceilings are expected to develop between 03-06Z and become
prevailing toward the end of the TAF period. Most terminals are
expected to drop to IFR flight conditions; however, LIFR
conditions will be possible. Greatest confidence for at least
temporarily LIFR conditions and drizzle between 09-12Z will be
across central Oklahoma from KLAW to KOKC/KOUN to KPNC.
Winds will remain light from the south to southeast through the
.PREV DISCUSSION... /issued 336 AM CST Wed Jan 18 2017/
Showers continue to dissipate this morning with the measurable
precipitation generally confined across western Oklahoma in
association with the vort max and southeast Oklahoma with
isentropic ascent. Will maintain a chance of showers across the
northwest this morning as the vort max lifts northward into Kansas.
Across southeast Oklahoma, both convective-allowing models and
the NAM12 indicate there will be at least a slight chance of
showers in the southeast through this evening. Progged 295 K
isentropic surfaces indicate some ascent coincident with the QPF
For tonight, at least patchy fog will be possible as suggested by
various guidance (SREF/RAP13/NAM12). The possibility of fog seems
reasonable because of the recent rains and for many locations, the
forecast low temperatures are equal to or lower than this
afternoon`s dewpoints. In addition, forecast BUFR soundings
indicate some drizzle will be possible--espousal near I-35 to the
east. Forecast soundings at KOKC/KPNC/KADM all indicate a
relatively deep saturated layer from the sfc to ~925 mb coincident
with weak isentropic ascent at the 290 K insentropic surface.
Thursday will begin a warming trend with temperatures around 10F
above average. Friday will be even warmer as both the 18/00Z GFS
and ECMWF indicate 850 mb temperatures ranging from 9-11C with
south to southwest low-level flow. As a result, high temperatures
are forecast to be in the 60Fs and 70Fs (~15F above average). Near
critical fire weather conditions will be possible--especially
across western Oklahoma and western north Texas.
Seasonably warm weather will continue into Saturday as the next wave
approaches the Southern Plains. Ascent ahead of wave may result in
some showers across the west Saturday afternoon.
The GFS and ECMWF are in excellent agreement that a closed mid/upper-
level low will track across the Red River late Saturday into
Sunday morning. Northern Oklahoma will be within the deformation
zone on the north side of the low. Western north Texas may get dry
slotted with minimal precipitation. The GFS has a greater
magnitude of cold air advection than the ECMWF with 850 mb
temperatures down to -1C in far northwest Oklahoma. BUFR sounding
from KGAG still indicate liquid precipitation as temperatures warm
above freezing just below 850 mb. So for now, opted to keep all
precipitation liquid. Very breezy conditions are expected Sunday
afternoon in the system`s wake. This may result in near critical
fire weather conditions once again across the west.
For Monday, southwest flow aloft returns ahead of the next wave.
Consequently, seasonable temperatures are expected with a return
to southerly winds by Monday afternoon. The greatest
ascent/precipitation chances from this system is currently progged
to stay north of Oklahoma; however, the airmass behind this system
will be colder than the previous system (though not too cold).
Therefore, at least slightly below average temperatures are
currently expected on Wednesday.
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 41 61 38 66 / 10 0 0 0
Hobart OK 41 61 37 66 / 0 0 0 0
Wichita Falls TX 40 67 42 69 / 10 0 0 0
Gage OK 40 58 33 63 / 0 0 0 0
Ponca City OK 42 58 39 62 / 10 10 10 0
Durant OK 46 65 45 68 / 20 0 0 0