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Area forecast discussion 
National Weather Service Norman OK
1044 PM CST Friday Feb 27 2015

Discussion...
another widespread round of accumulating snow is expected
after 2 am tonight into Saturday.

Latest radars indicated one band of snow associated with
frontogenesis around 800 mb from near Chickasha to Norman to
Seminole...which is forecast to weaken over the next few hours as
it moves northeast. Additional light snow continues across
southern Oklahoma and western North Texas. Accumulations from
these features are expected to be light...generally a dusting to
one inch through the night.

The next round is just getting started over the panhandles
to our west. This will move east and impact the area late tonight
into Saturday. The I-35 corridor will begin to be impacted in the
6 am to 8 am range. Light to moderate snow will be the main
weather type...though some sleet and even freezing rain may occur
over southern Oklahoma and western North Texas as warmer air
aloft moves in. Kept accumulations in the 1 to 4 inch range with
the highest accumulations in northern Oklahoma where banding of
moderate snow is highest...although latest hrrr runs have been
shifting the heaviest snow farther south closer to I-40.

During the day on Saturday into Sunday morning...light ice
accumulation from freezing drizzle and light rain freezing rain
will be another big concern...and will only enhance slick and
hazardous travel. Although ice amounts are expected to be light
and generally under 0.10 inch...glazing may be widespread.

Slick and hazardous travel will continue through Sunday in many
locations. Some improvement may occur as early as late Saturday
afternoon in far southern Oklahoma and western North Texas where
temperatures will rise above freezing first.

Aviation discussion for the 06z tafs is below.

Mbs

&&

Aviation...
have moderate confidence in the tafs.

Through 09z...think all locations will bounce between VFR/MVFR
with areas of -sn. IFR conditions may occur briefly at nearly
any site except kpnc.

After 09z...another batch of heavier -sn with IFR or lower
conditions will move into and through the area. Kokc will be
affected mainly 12-21z and klaw will be affected 10-19z. Ksps
may be affected 10-17z as well. -Pl may occur south of kcsm-
kswo...but did not mention due to low chances of occurrence.

After 17z...-fzdz will likely develop and spread northward...
affecting mainly locations south of kcsm-kokc. IFR or lower
conditions will likely continue during this time frame as well.
Widespread LIFR conditions may develop after 00z.

Mbs

&&

Previous discussion... /issued 543 PM CST Friday Feb 27 2015/

Discussion...
aviation discussion for the 00z tafs is below.

Aviation...
have moderate confidence in the tafs.

Through 09z...think all locations will bounce between VFR/MVFR
with -sn flurries.

After 09z...another batch of heavier -sn with IFR or lower
conditions will move into and through the area. Kokc will be
affected mainly 12-21z and klaw will be affected 10-19z. Ksps
may be affected 10-17z as well.

After 17z...fzdz may develop and spread northward...affecting
mainly locations south of kcsm-kokc. IFR or lower conditions will
likely continue during this time frame as well.

Mbs

Previous discussion... /issued 256 PM CST Friday Feb 27 2015/

Discussion...
the first round of this multi-part weather event is starting to
wind down. Through midnight...significant snowfall should be
restricted to the southern third or so of Oklahoma...and western
North Texas. Things begin to turn very complicated tomorrow...as
higher temperatures start to advance north. This will...over the
course of the weekend...turn the snow to sleet...freezing
rain...and then rain...with various combinations thereof during
the transition period.

The previously-issued advisories appear to make sense for the
rest of today/this evening. However...the evening shift will need
to take another look at snow/ice accumulation potential
overnight...especially over southern Oklahoma and western North
Texas. This may require an extension of our current advisory for
that area.

The main brunt of the next upper-level wave should affect the
northern two rows of counties in Oklahoma tomorrow. Snowfall
should be sufficient to warrant the Winter Weather Advisory that
will be new with this forecast update.

Freezing rain will probably require additional advisories over the
weekend...but uncertainty in timing and location preclude issuing
them now.

By Tuesday...most of the winter weather will temporarily make way
for a springlike day...complete with a chance of thunderstorms
over the southeastern half or so of Oklahoma. At this
time...severe weather appears to be unlikely.

In keeping with the theme of wild extremes of weather...another
strong cold front is scheduled to arrive Tuesday afternoon in
northwest Oklahoma...and late Tuesday evening in the southeast.
Some light snow or other freezing/frozen precipitation will be
possible with this system...but it does not look like a
significant event. And...by the end of the week...temperatures
should rebound to a few degrees below the seasonal average.

&&

Oun watches/warnings/advisories...
OK...Winter Weather Advisory until midnight CST tonight for okz019-
020-025-026-028>032-040>043-047-048.

Winter Weather Advisory from 6 am to 6 PM CST Saturday for
okz007-008-012-013-018>020-024>032-040>043-047-048.

Winter Weather Advisory until 6 PM CST Saturday for okz004>006-
010-011-015>017-023-038.

Winter Weather Advisory until noon CST Saturday for okz009-014-
021-022-034-035.

Winter Weather Advisory until 6 PM CST Saturday for okz039-
044>046-050>052.

Winter Weather Advisory until noon CST Saturday for okz033-036-
037.

Texas...Winter Weather Advisory until 6 PM CST Saturday for txz086-089-
090.

Winter Weather Advisory until noon CST Saturday for txz083>085-
087-088.

&&

$$

03/17

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