Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Norman OK
1226 PM CDT sun Aug 30 2015
aviation discussion for the 18z tafs is below.
VFR conditions are generally expected. Surface winds should stay
below 10 knots at all locations through 14z Monday before increasing.
Patches of MVFR or lower conditions with br may occur 07-15z
mainly over northern Oklahoma...but did not mention in tafs due
low confidence of occurrence.
Previous discussion... /issued 1113 am CDT sun Aug 30 2015/
the update this morning is mainly to remove mention of fog and
morning thunder. Fog has cleared all of the observation sites. If
there is some lingering fog over Alfalfa/Grant counties... do not
expect it to remain long and conditions will continue to improve.
To the south... one isolated shower is drifting across Bryan
County... but otherwise have seen no significant development. Will
keep the mention of isolated shower for the morning hours but
reduce probability of precipitation to less than 20. Still some mixed signals for
redevelopment this afternoon in the southeast and will leave the
low afternoon probability of precipitation in the southeast.
Previous discussion... /issued 646 am CDT sun Aug 30 2015/
30/12z taf issuance.
LIFR conditions in fog/stratus are expected across northern
Oklahoma terminals through 15z. Will also mention MVFR fog over
central Oklahoma terminals of kokc/koun first few hours of
forecast. Otherwise VFR forecast with light northerly winds
becoming light southerly late in the afternoon and tonight.
Previous discussion... /issued 406 am CDT sun Aug 30 2015/
main adjustment to going forecast package was to add fog for this
morning across areas north of I-40. The most widespread and
possibly dense fog will be over far north/northwest Oklahoma
nearest low level ridge axis. Confident that there will be fog but
just not sure how widespread any dense fog will be. The most
aggressive models...WRF and hrrr keep a majority of dense fog up
in Kansas through 9 am. Dense fog advisory not anticipated at this
point but we will watch trends and issue as needed. Probability of precipitation were also
continued through today across southeast County Warning Area near middle-level shear
axis and effective synoptic boundary.
Todays temperatures were cooled a bit from previous forecast as well.
Initializations came in a few degrees cooler mainly over northern
and western Oklahoma...and with plume of high level smoke this
sounds reasonable. GFS and ecm have trended weaker with the upper
level ridge and have generally underforecast strength/persistence
of longwave trough axis just to our east. This will yield slightly
cooler temperatures through the week most areas and although probability of precipitation are too
low to mention...cannot rule out an isolated shower or weak storm
especially far northwest Oklahoma closer to possible High Plains
remnants and far southeast Oklahoma closer to upper trough.
Preliminary point temps/pops...
Oklahoma City OK 68 93 70 92 / 0 0 0 0
Hobart OK 67 97 71 95 / 0 0 0 0
Wichita Falls Texas 71 97 72 96 / 0 0 0 0
gage OK 63 96 69 94 / 0 0 0 0
Ponca City OK 67 93 70 93 / 0 0 0 0
Durant OK 71 95 71 94 / 10 10 0 10