Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Norman OK
529 am CST Sat Dec 27 2014
the 12z aviation discussion follows....
a wintry mess is occurring early this morning across the western
half of Oklahoma...and western North Texas. Surface reports
indicate snow...pl...ra...and possibly some freezing rain. In the heavier
bands of snow...visibilities abruptly but temporarily dip to below 1
sm. This area of precipitation is expected to shift slowly southeast and
diminish through the day today...and by late afternoon should
have ended at all our taf sites. -Ra and -sn will continue in east OK
into the evening. Skies will clear tonight...and winds will
diminish and become light and variable.
Previous discussion... /issued 432 am CST Sat Dec 27 2014/
radars show a large area of light precipitation over much of our
forecast area early this morning. Surface reports...from regular
observing sites and from the ping project...indicate a wide
variety of precipitation types. In addition...the lightning
detection network showed a couple of cloud-to-ground strikes over
southern Garvin County earlier this morning. It is unclear how
much of the precipitation that the radars show is actually
reaching the ground.
Short-range models indicate that that the existing precipitation
should become more scattered or end over the southeast 1/4 or so
of our forecast area...but the band of mixed precipitation will
persist through the morning. Some light snow accumulations are
possible...especially on grassy and elevated surfaces. Warm
ground temperatures should prevent significant accumulations on
most roads and sidewalks...but if a heavier band of snow or sleet
develops...there could be a few exceptions. Also...the weak
instability that supported earlier thunderstorms is expected to
diminish...so lightning/thunderstorms are unlikely after sunrise.
The precipitation is forecast to shift slowly southeast
today...and end tonight. Dry weather is expected thereafter until
Thursday...New Years Day.
Next Thursday will likely start with areas of sleet and freezing
rain...before temperatures rise enough to turn the mix into all
rain over most of our forecast area. Depending on ground
temperatures and precipitation intensity/duration...this has the
potential of being quite problematic. There is a lot of time and
potential for this scenario to change...however.
Monday will be the only day of the next seven with near-average
temperatures...before a feeble warming trend is abruptly halted by
a very large mass of Arctic air. This mass of low-level cold air
is the reason for the chance of freezing rain/sleet on Thursday.
Precipitation chances will continue into Friday...but less-cold
weather will turn most of the precipitation to rain. Frozen or
freezing precipitation will still be possible in northern
Oklahoma during the day on Friday...and will then spread
southeast Friday night as temperatures drop again.
Preliminary point temps/pops...
Oklahoma City OK 37 24 43 28 / 20 0 0 0
Hobart OK 38 20 43 25 / 20 0 0 0
Wichita Falls Texas 40 24 48 31 / 30 0 0 0
gage OK 36 14 43 17 / 0 0 0 0
Ponca City OK 38 20 40 24 / 20 0 0 0
Durant OK 41 28 46 31 / 50 20 0 0