Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 211731

Area Forecast Discussion
National Weather Service North Platte NE
1131 AM CST Wed Feb 21 2018

Issued at 324 AM CST Wed Feb 21 2018

H5 analysis from earlier this evening had a ridge of
high pressure across the western Atlantic and ridging in the eastern
Pacific. Across the CONUS, a trough of low pressure extended from
central Canada south southwest into the swrn CONUS. Within this
trough several shortwaves were noted. The first was located across
the Dakotas, a second around the four corners, a third off the coast
of California, and a fourth over swrn portions of British Columbia.
Strong high pressure was located off the North Carolina coast, with
a second high located in the Gulf of Alaska. At the surface: An
arctic cold front had pushed well south of the forecast area over the
past 24 hours, and extended from central Texas into western portions
of the Ohio valley. Arctic high pressure had built into northern
Nebraska overnight. with clear skies and fresh snow cover in place,
bitterly cold temperatures had set in across western and north
central Nebraska. Readings as of 3 AM CST ranged from 6 at Broken
Bow to -9 at Valentine and Thedford.


.SHORT TERM...(Today and tonight)
Issued at 324 AM CST Wed Feb 21 2018

High pressure will build east into the upper Mississippi valley
today. Southeasterly winds will increase today, allowing return
low level moisture to surge north from the southern plains. This
surging moisture, will result in increased cloudiness tonight as
low cloudiness pushes into the forecast area from the south. In
the meantime, today, skies will be clear to partly cloudy.
Temperatures will be cold however, given the cold start and
widespread, fresh snow cover. Afternoon highs will be in the upper
20s to around 30 which is around 15 degrees below normal for this
time of year. As mentioned earlier, low level moisture will
increase from south to north tonight thanks to increased southerly
and southeasterly winds. Aloft, a H5 trough of low pressure will
drop south into the four corners. Downstream of this feature, mid
level warm air advection will increase overnight, leading to an
increased threat for precipitation. Light precipitation is
expected to develop after midnight in south central Nebraska,
lifting north into the forecast area overnight. As for
precipitation type, based on Bufkit sounding data and fcst
temperature profiles tonight per the NAM12 solution, all snow is
expected. Fcst QPF`s remain on the light side for tonight, so any
snow amounts will be very light with the main show arriving on

.LONG TERM...(Thursday through Tuesday)
Issued at 324 AM CST Wed Feb 21 2018

An active ending to the week is expected across north central
Nebraska as a couple winter systems move across the region. The
first system continues to impact the area on Thursday. Surface
temperatures are expected to be in the mid 20s on Thursday. In
addition, model soundings indicate that the atmosphere should
support an all snow forecast. Therefore, new snow totals should be
between 1 to 2 inches. The best locations to see the heaviest snow
will be across north central Nebraska (near O`Neill). Snow will move
out of the area by 6pm Thursday.

The second system tracks across the central Plains on Friday night
and into Saturday. Model guidance is still a bit uncertain in the
track and strength of this storm. A few models have a pretty decent
snowfall band over central Nebraska which could drop a significant
amount of snow (up to 10 inches or more). However, confidence in
this is quite low and have decided to go a more modest snowfall
forecast for now. Have put in a fairly widespread 1 to 3 inches
across the majority of the forecast area. The only locations not
expected at this time to see snowfall will be across the Pine Ridge
region. Another concern with this system that will have to be
watched over the next couple days is the chance for some freezing
rain across the eastern half of the forecast area. Model guidance is
not too convincing of significant icing, however, it does warrant at
least a mention.

A quiet and dry pattern returns from Saturday night through next
Tuesday. Another chance of snow arrives mid-week. Will only put in a
mention of some light snow for now until this system is better
sampled and it`s track becomes more certain.

For temperatures, highs will return into the 30s after only rising
into the mid-20s on Thursday. The beginning of next week (Monday
through Tuesday) could see highs return to the upper 30s and low
40s. For overnight low temperatures, generally upper teens to low
20s will be seen across the forecast area through the middle of next


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1131 AM CST Wed Feb 21 2018

VFR conditions and a slight southerly breeze will continue
through this evening across western Nebraska. Cloud cover
increases and cigs drop to MVFR overnight as the next storm
system approaches. Light snow will develop across southwest and
central Nebraska Thursday morning (affecting LBF), then slowly
spread into northern Nebraska (including VTN). IFR cigs and visby
are possible after 22/12z southwest and 22/15z north central.




SHORT TERM...Buttler
AVIATION...Snively is the U.S. government's official web portal to all federal, state and local government web resources and services.