Scientific Forecaster Discussion
fxus63 koax 222328
Area forecast discussion
National Weather Service Omaha/valley NE
528 PM CST Fri Nov 22 2019
..updated for 00z aviation forecast discussion...
issued at 230 PM CST Fri Nov 22 2019
some light snow accumulation is possible this afternoon into
evening along the Kansas border, and potentially into far
southwest Iowa. Warmer temperatures can be expected this weekend
into Monday. Attention then turns to a weather system that may
bring rain and snow to the area Monday night into Tuesday night.
Slightly warmer temperatures are expected by Thanksgiving.
early afternoon water vapor imagery depicts separate vorticity
maxima over western Kansas and and northeast KS, yielding an elongated
band of frontogenetically forced snow across northern Kansas into
southern NE. Latest convection-allowing model data suggest that
the eastern vorticity lobe will sustain the snow band over
portions of far southeast NE this afternoon with possible
development into far southwest Iowa by late afternoon or early
evening. Accumulations should remain generally less than an inch
with the snow tapering off by late evening.
Saturday into monday:
an evolving quasi-zonal flow regime aloft will translate to a
warming trend into the weekend. Highs on Saturday will be in the
mid 40s to around 50 with readings in the mid to upper 50s on
Sunday. On Sunday night into Monday, a weak front will move
through the area with highs on Monday in the upper 40s to mid 50s.
Monday night into wednesday:
a fast-moving short-wave trough is forecast to translate from the
central and southern rockies through the Central Plains into the
Great Lakes and Ohio Valley. While model differences still remain in
the track and timing of this system, confidence in it affecting
our area has increased over the past 24 hours. Low-level thermal
profiles remain uncertain, which has implications on precipitation
type and any potential snowfall amounts. Current indications are
that the bulk of precipitation would fall Tuesday into Tuesday
evening. We will indicate highs in the lower 40s on Tuesday.
However, those values could end up lower, or vary more
drastically from north to south across our area.
Thursday and friday:
there continues to be a consistent model signal in the development
of a large mid-level trough along the Pacific coast with
downstream ridging across the Great Plains. That pattern evolution
would be supportive of warmer temperatures with a low-probability
chance of rain or snow.
Aviation...(for the 00z tafs through 00z Saturday evening)
issued at 530 PM CST Fri Nov 22 2019
Some MVFR conditions will be possible at klnk tonight, but look
for mainly VFR conditions at koma and kofk. Southerly winds will
shift to northwest as a weak front pushes through the region.