Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 141739

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1239 PM CDT Wed Mar 14 2018

.SHORT TERM...(Today through Friday)
Issued at 315 AM CDT Wed Mar 14 2018

Multiple forecast issues to deal with, fire weather today, then
mixed precipitation (with snow and ice accumulations for parts of
the area) starting by late Thursday night and continuing Friday.

Yesterday we were still under the influence of the cool airmass
associated with high pressure that settled south across the area,
but that has shifted off to the south and southeast. South/
southwest winds today will bring in warmer air, and with some
downslope component we should warm into the 60s at most locations.
Relative humidity values will drop to around 20 percent near the
KS and MO borders with winds mainly 10 to 20 mph. Fire danger will
be very high but probably not quite to the point that a Red Flag
Warning would be needed. The day shift can take a look and issue
one if needed. Will highlight the elevated fire danger in our
products. A cold front is expected to push down into the northern
parts of the forecast area with winds shifting to north or
northeast. Thus fire danger should not be quite as high Thursday.

That front will continue to settle southward tonight, possibly
down into the northern parts of MO and KS by 12z Thursday. At the
same time, low pressure will be organizing over WY and CO. Highs
will be cooler Thursday, especially northern and central parts of
the forecast area with less favorable winds for mixing.

Pattern will become much more favorable for precipitation Thursday
night as 500 mb trough to our west takes on a negative tilt and a
closed low forms. Current model guidance does have some variance
with the 00Z GFS farther north than the ECMWF. 00Z NAM location of
the closed low at 12z Friday was east of the ECMWF and southeast
of the GFS. Temperatures will start out fairly mild Thursday
evening but will cool during the night as precipitation develops.
The surface temperature progs suggest that our southern counties
will remain well above freezing but could drop to near freezing in
the north. Elevated instability works into at least southeast NE
Thursday night, expect isolated thunderstorms there. Precipitation
north of a line from around Neligh to Oakland IA will likely be
mixed, with some freezing rain and sleet. This is somewhat based
on a blend of guidance. If the 00z GFS solution ends up being more
correct, we could have more rain and not as much freezing rain or
sleet from Thursday night into Friday morning. If temperatures
warm as expected, we will see mainly rain Friday afternoon. The
exception to this is northeast NE where it could remain a mix.

.LONG TERM...(Friday night through Tuesday)
Issued at 315 AM CDT Wed Mar 14 2018

Models retain general agreement with the overall pattern from
Friday night through Sunday, with some variance. The GFS remains
farther north with the closed low Friday night. Through sunrise
Saturday, at this time, we expect snow amounts to be confined to
northeast NE with amounts an inch or less. Total ice amounts
through sunrise Saturday could be up to 0.15 inches generally
along and north of a line from around Neligh to Tekamah and
Oakland IA.

Current forecast has mainly dry weather from Saturday afternoon
through Sunday morning, then we will have chances for rain and
snow Sunday night into Monday night. The 00z ECMWF had higher
precipitation amounts compared to the GFS and at this time the
values seemed too high.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1232 PM CDT Wed Mar 14 2018

VFR conditions are expected through the period with only a few
passing high level clouds towards the tail end of the TAFs. As a
result...primarily a wind forecast with occasionally gusty
southwest winds continuing through the late afternoon
hours...before winds decouple and become light and variable this
evening. Overnight...expect winds to shift and become
northeasterly across the area...with the pressure gradient
increasing during the morning hours Thursday...likely resulting
in a fairly breezy afternoon tomorrow.


NE...Red Flag Warning until 7 PM CDT this evening for NEZ068-088>093.

IA...Red Flag Warning until 7 PM CDT this evening for IAZ090-091.



LONG TERM...Miller
AVIATION...Rossi is the U.S. government's official web portal to all federal, state and local government web resources and services.