Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 030913
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
313 AM CST Sat Dec 3 2016

.SHORT TERM...(today through Monday)
Issued at 225 AM CST Sat Dec 3 2016

Precipitation will likely develop today as a short wave lifts
through the northern Plains with strong warm air advection
developing across the region. Greatest precipitation chance will
be along/south of I80 where we will increase pops into the 60-70
percent range today, with all precip slowly shifting east tonight
and east of the forecast area by daybreak Sunday.

We are expecting a mixture of precip today, which could start as
snow in southeast Nebraska yet this morning as the column saturates
down to the wet bulb. As temperatures warm through the day, should
mix with or change to rain, then back to a snow/rain mixture by
early this evening, with precip pulling to the east through the
night. A lot of the snow accumulation should melt today with
daytime insolation, and even with temps still in the mid 30s
during the evening, a lot of melting will occur. Even lows
overnight in southeast NE and southwest IA will be still just
above freezing in the lower 30s, which should help to limit
accumulations. 4" soil temperatures are also running fairly warm
along/south of I80 in the lower 40s. Note, the raw model snow
output from various solutions would suggest 1-3" might be possiblein
southeast NE and southwest IA along/south of I80. However, due to
the rain/snow mix and expected melting, we`ll have an inch or less
in our grids, and then mostly just on grassy surfaces. QPF through
the next 24 hours ranges from 0.1" to 0.2".

Very mild conditions develop for both Sunday and Monday.
Northwesterly downsloping flow will prevail for Sunday which will
help boost temps back into the mid 40s. Southwesterly flow Monday
should yield one more much above normal day in the mid to upper
40s with dry conditions.

.LONG TERM...(Monday night through Friday)
Issued at 225 AM CST Sat Dec 3 2016

A cold front will arrive Monday night, which will begin to usher
in a brief period of arctic-like temperatures through the end of
the week. There could be a few snow showers or flurries with the
front Monday night. The initial surge should be east of the area
early Tuesday, but will still hang on to a 20 percent chance of
light snow or flurries based on previous model blends, but new 00z
models are suggesting it will probably be dry Tuesday.

The next trough moving out of the Rockies appears to be taking a
slightly more southern track mid week based on GFS and ECMWF. The
Canadian model is even further south and would keep the area dry.
Thus, will reduce overall probabilities in our area into the
20-30% range from Tuesday night through Wednesday, and then for
just the southern half of the forecast area as the system is
trending south. Still too early to focus on snowfall amounts, but
if it does snow, the amounts appear to be on the light side.

Sharply colder temperatures are probably the bigger weather story
in the extended period. Highs both Wednesday and Thursday will
only be in the teens. When combined with blustery northwest winds,
wind chill values will drop into the single digits above and below
zero. Temps do begin to rebound a little by Friday into the mid
20s, but still well below normal. We may even see moderation back
into the 30s for Saturday, so this first arctic intrusion appears
to be fairly brief.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1132 PM CST Fri Dec 2 2016

Mid and high-level clouds will continue to overspread the area
tonight in advance of a short-wave trough progressing into the
High Plains. The impulse will subsequently track east across the
region on Saturday, promoting development of a southwest-to-
northeast-oriented precipitation shield across portions of
eastern Nebraska and southwest Iowa. While KOFK is expected to
remain to the north of this precipitation, it will be impacted by
the arrival of MVFR ceilings late Saturday afternoon. At KOMA and
KLNK, precipitation is expected to begin by late morning or early
afternoon and continue into at least Saturday evening. Model
variability in the structure of the low-level thermodynamic
profiles yields various precipitation type forecasts. For now, the
highest probability scenario is a rain-snow mix with precipitation
rates peaking in intensity from mid afternoon into early evening.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&

$$

SHORT TERM...DeWald
LONG TERM...DeWald
AVIATION...Mead


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