Scientific Forecaster Discussion
fxus64 koun 152130
Area forecast discussion
National Weather Service Norman OK
330 PM CST Fri Dec 15 2017
main focus for impactful weather continues to be fire weather
conditions. Temperatures will be near to slightly above normal for
the next several days until a much colder pattern settles in late
next week. Rain chances increase tomorrow evening/night with light
amounts, primarily across the eastern two-thirds of the area.
Otherwise dry conditions are expected until low probabilities
return in the south late next week.
Latest visible satellite imagery shows clear skies across the
region. Temperatures are mild and near normal for mid-December.
Slightly warmer weather will return tomorrow as most locations
make it to the lower 60s for high temperatures. Strengthening
southerly winds are expected as western trough deepens. Mid-upper
low over the Gulf of California will open and move quickly
northeast into the area providing ascent to increasingly moist
environment. This will result in some rain across the area
tomorrow evening into the night, with the best chances being
across eastern Oklahoma. Models diverge early next week in the
degree to which western trough closes off and its timing as it
moves east. This will probably necessitate mainly minor
adjustments in the forecast as the time nears and models come into
Large trough to our west will force a strong cold front through
Thursday bringing much colder air to the area. There's general
agreement in the synoptic scale pattern in medium range guidance
which shows a deep closed off southern stream system to our west.
At this time southerly warm/moist advection atop the cold front
looks to yield a minor precipitation event at best, and primarily
to our south. Nevertheless, preliminary thoughts are that some
wintry precipitation may occur across the southeast portions of
the area by Friday. Details with regard to amounts and
precipitation type will be better resolved in the coming days.
despite fairly deep mixing and low relative humidity values this afternoon, winds
are fairly light limiting the potential for significant fire
spread. Nonetheless, some initial attack fire activity may occur
through the rest of the afternoon.
Bigger (albeit somewhat conditional) concerns arise tomorrow as
southerly winds increase markedly in response to deepening western
trough. 20-30 knot southerly winds with gusts approaching 40 will
be possible over far western Oklahoma. Relative humidity values stand the best
chance of dropping to near critical or critical levels in
northwest Oklahoma if cirrus is a little slower to increase over
the area than currently expected. Current indications are that the
timing/position of the ejective shortwave trough should support
fairly thick cirrus and eventually mid-level deck by afternoon
across especially western North Texas and southern Oklahoma,
spreading into northern Oklahoma by early afternoon. This would
limit fuel heating and temper mixing depth some. Another mitigating
factor will be lack of anomalous temperatures (lower 60s for
highs). Nevertheless, potential for initial attack fire activity
will increase, and conditions could briefly reach critical levels
in northwest Oklahoma tomorrow afternoon.
The next potential fire weather day may be Thursday as
warm/downsloping southwesterly winds occur ahead of a cold front.
Strong northerly winds will occur with the frontal passage late
Thursday or Thursday night.
Preliminary point temps/pops...
Oklahoma City OK 52 31 60 44 / 0 0 0 50
Hobart OK 54 28 60 41 / 0 0 0 20
Wichita Falls Texas 56 31 61 44 / 0 0 10 40
gage OK 58 27 61 36 / 0 0 0 20
Ponca City OK 53 30 60 44 / 0 0 0 60
Durant OK 54 33 61 44 / 0 0 10 70