Forecast Discussion
NWS Omaha/Valley, NE

000
FXUS63 KOAX 190033
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
633 PM CST Fri Jan 18 2019

.UPDATE...
Issued at 626 PM CST Fri Jan 18 2019

Trimmed out a few counties from the winter weather advisory in
northeast NE where additional significant winter weather is not
expected. Also converted most of the winter storm warning in
southeast NE and southwest IA back to the winter weather advisory
as the heaviest snow band appears to be setting up just south of
the region. Kept Richardson county in the winter storm warning,
and lowered snow amounts just a little there.

Otherwise, freezing drizzle continues over much of east central NE
and west central IA, although it has switched to light snow from
about Columbus to Wayne. Flat ice accumulation measurements from
our ASOS locations have ranged from 0.16 to 0.22, which converts
to about 0.06 to 0.09 radial ice.

&&

.SHORT TERM...(Tonight through Monday)
Issued at 332 PM CST Fri Jan 18 2019

Freezing drizzle and snow overnight, then cold temperatures through
the weekend, are the primary highlights of the forecast.

Mid level trough was moving through the region this afternoon. And
as expected yesterday, two distinct areas of heavier precipitation
developed, one from southeast SD into northern IA/southern MN, and
the second from northeast Kansas into southern Iowa. However, in
between, mid level dry air had eroded moisture from dendritic
temperature zone, thus effectively shutting off seeder-feeder
mechanism for snow formation. Strong warm advection continued over
low level cool and moist surface layer, leading to widespread
freezing drizzle across much of eastern Nebraska and southwest Iowa.

Meanwhile, southern stream system was finally emerging from the
Southern Plains and was inducing lift from central Kansas into
southern Iowa. Latest satellite and radar trends suggests this will
be the line of heaviest potential snowfall into the evening. However
duration of snow in our far southeast Nebraska and far southwest
Iowa counties likely will be limited, thus limiting snow totals.

Given ice accumulation already today, will continue with Winter
Weather Advisory across much of our area into the evening. We may
see a period of snow from Interstate 80 and south where mid level
moisture increases are possible, which will only contribute to the
already slippery conditions. Will also maintain the Winter Storm
Warning in our far southeast where an uptick in snowfall is expected
late this afternoon and evening.

Any precipitation will end by Saturday morning as system pulls to
the east, then cold high pressure will follow for the afternoon.
Persistent northerly surface winds and cold advection should keep
temps from gaining too much from morning lows. Then another
shortwave dropping through Minnesota and Iowa on Sunday will
induce a return to southerly low level flow Saturday night keeping
lows from bottoming out. Still single digit lows and wind chills
below zero are expected. That wave could also trigger flurries or
a light snow shower Sunday afternoon, especially in west central
Iowa.

Our next mid level trough will begin to move toward the region on
Monday. As it does, increasing theta-e advection into our area will
again saturate low levels and provide lift for drizzle or freezing
drizzle by Monday afternoon.

.LONG TERM...(Monday night through Friday)
Issued at 332 PM CST Fri Jan 18 2019

Another chance for freezing drizzle and snow will begin the longer
term period, with cold temperatures continuing through the week.

Mid level trough is forecast to swing into the Plains Monday night
and exit to our east Tuesday night. Continued theta-e advection will
maintain chance for freezing drizzle Monday evening before deeper
saturation and a change to snow occurs after midnight. This is
another progressive wave, so widespread heavy snow is not
anticipated, but mesoscale bands could drop several inches of snow
in a short period.

Colder air follows this system for the rest of the work week, with a
reinforcing shortwave dropping into the region Thursday into Friday.
A chance for more snow will accompany this wave as early as Thursday
as per the GFS. ECMWF is a bit stronger and slower with this system,
and would paint a decent swath of snow across eastern Nebraska and
western Iowa.

Otherwise high temperatures will average the 20s through the week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 626 PM CST Fri Jan 18 2019

Still a few flurries at KOFK, but ending soon. Still freezing
drizzle at KOMA, but becoming snow by 02z, and ending by 06z.
Still a chance of freezing drizzle or light snow at KLNK, but
visibility has improved there so that may be a good sign.
Otherwise, northerly winds at 17 to 27 knots early in the taf
period.


&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Winter Weather Advisory until midnight CST tonight for NEZ015-
     018-030>034-042>045-050>053-065-066-078-088-089.

     Winter Weather Advisory until 6 AM CST Saturday for NEZ067-068-
     090>092.

     Winter Storm Warning until 6 AM CST Saturday for NEZ093.

IA...Winter Weather Advisory until midnight CST tonight for IAZ043-
     055-056-069.

     Winter Weather Advisory until 6 AM CST Saturday for IAZ079-080-
     090-091.

&&

$$

UPDATE...Forecaster
SHORT TERM...Dergan
LONG TERM...Dergan
AVIATION...Forecaster

NWS OAX Office Area Forecast Discussion

Forecast Discussion
NWS Hastings, NE

000
FXUS63 KGID 182326
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
526 PM CST Fri Jan 18 2019

.SHORT TERM...(This evening through Saturday)
Issued at 320 PM CST Fri Jan 18 2019

Observations continue to come in with some freezing drizzle at times
for much of the area this afternoon. Temperatures are only a few
degrees below freezing for many locations, but temperatures have
started falling across the northern part of the forecast area this
afternoon and will continue to fall through the rest of the
afternoon and during the evening.

Because much of the precipitation is drizzle, many of the models are
not handling the areas with precipitation very well. Those that do
show some precipitation for the area are fairly consistent that it
will gradually end from west to east across the area during the
afternoon and evening. Soundings indicate that much of the
precipitation will be freezing drizzle, but toward the end, just
before the precipitation ends, there could be a little bit of snow.
The precipitation should be coming to an end during the evening.
Since it is hard to tell where there is freezing drizzle, have
decided to leave the advisory alone for now and will probably be
able to expire it sometime during the evening.

As a surface high builds into the area late tonight into Saturday,
clouds will start to diminish. Tonight, skies will be mostly cloudy
and should become mostly sunny on Saturday. The temperatures tonight
will dip into the 8 to 15 degree range with wind chill values of -5
to -10 degrees. For Saturday, there will be some warm advection
later in the day, but temperatures will remain cool with highs
mainly in the 20s.

.LONG TERM...(Saturday night through Friday)
Issued at 320 PM CST Fri Jan 18 2019

Saturday night through Monday will be a dry period. There will be
warm advection Saturday night into Sunday and the temperatures are
expected to warm up some on Sunday, but as another cold front moves
through Monday, temperatures will fall back just a little bit.

Another upper level wave will move through the area Monday night
into Tuesday. Will need to keep an eye on this system as it moves
into the area. The first look appears like it would be mostly snow
because the temperatures are fairly cool, but there could be a short
period early in the system where the dendritic layer would not have
enough moisture and there could be a brief period of freezing
drizzle at the start. Have kept it all snow at this time, but will
need to watch this system.

The next break between systems will be Tuesday night through
Wednesday night. Temperatures warm back up a little bit, but still
only about normal for this time of year.

Thursday through Friday there are several mainly weak, quick moving
systems that move through the area. There could be some on and off
snow and rain as these systems move through. Temperatures will be
around or just a little below normal.

&&

.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Saturday)
Issued at 522 PM CST Fri Jan 18 2019

Conditions are forecast to improve through this TAF period, but
the next few hours still has IFR conditions in the forecast. VFR
conditions are expected to return, kept it on the slow side of
things, not returning until 10Z. It`s possible it`ll be before
that time. Though the threat for precipitation is waning, kept a
mention of light SN/FZDZ going for a couple more hours...will then
be dry through the rest of the period. Gusty northerly winds look
to linger thorugh the overnight hours...with the late
morning/afternoon hours tomorrow closer to 10-15 MPH.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...Winter Weather Advisory until midnight CST tonight for
     NEZ039>041-046>049-060>064-072>077-082>087.

KS...Winter Weather Advisory until midnight CST tonight for
     KSZ005>007-017>019.

&&

$$

SHORT TERM...JCB
LONG TERM...JCB
AVIATION...ADP

NWS GID Office Area Forecast Discussion