Sidney, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

209
FXUS65 KCYS 301743
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1143 AM MDT Sun Mar 30 2025

.KEY MESSAGES...

- Snow and rain showers continue into the day Sunday with
  additional snowfall accumulations generally under an inch.

- Active pattern this week bringing more chances for wind and
  precipitation.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 441 AM MDT Sun Mar 30 2025

Current radar returns from KCYS show light precipitation across
the Interstate 80 corridor. ASOS stations and webcams along
Interstate 80 corroborate this with observations of falling
snow. Light snow is expected to continue through the morning
hours, expanding in coverage to the Interstate 25 corridor and
the Nebraska panhandle, per Hi-Res guidance. Additional snow
accumulations during this time appear minimal, with most
locations expected to see less than an inch. Snow will taper off
by early afternoon. Another round of showers will be possible
later this afternoon. These convectively driven showers will
develop thanks to decent surface instability and low-level
frontogenesis this afternoon. This next round of showers looks
to mainly be confined to the Interstate 80 corridor. Given the
instability, cannot rule out a few rumbles of thunder this
evening with any showers. Some snow accumulation could be
possible this evening if rain transitions to snow quickly. Any
snow showers will likely dissipate after midnight as shallow,
but brief, upper-level ridging engulfs the Rockies.

An upper-level disturbance pushing into Wyoming on Monday will bring
yet another round of precipitation to the CWA. Increasing mid-level
moisture as well as decent mid-level frontogenesis will lead to the
development of fairly widespread precipitation across the area.
Given that warmer temperatures are expected during the day Monday,
precipitation will likely start off as rain in most locations before
transitioning to snow overnight. Orographic lift will aid in good
snowfall rates Monday night in the mountains, so headlines could be
needed for both the Sierra Madre and Snowy Ranges. Snowfall amounts
could exceed 8 inches in the mountains during this time. Will also
have to keep an eye on the lower elevations west of the Laramie
Range as a few inches of snow accumulation could be possible Monday
night.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 441 AM MDT Sun Mar 30 2025

An active wet pattern continues through the long
term forecast. The uncertainty is substantial next weekend as each
global model has the same general idea but differs on location which
can have differing effects for the Southeast Wyoming and Nebraska
Panhandle areas. Starting Tuesday, an upper level wave creates some
leeward cyclogenesis in central to northeast colorado. There is an
amplified ridge over the Midwest and into part of the eastern coast
of the US. This ridge provides the steering flow for the newly
developed low pressure system to travel directly across our area.
Tuesday will be rather breezy as a low level jet intensifies from 30
to 40 kts in the morning to 50 to 55kts by the evening into the
overnight hours. As this low pressure system travels over us, the
synoptic lift will be strong allowing for widespread precipitation
chances to occur. Throughout the day Tuesday, there will be mainly
snow chances in the as the snow levels look to be around 5,000ft.
Depending on how strong the warm air advection is from this system
there could be a rain/snow mix for the Southeast Wyoming area while
the Nebraska will start with rain and change to snow by the evening
into the overnight hours. The 25th percentile has an inch or less
for areas east of I-25 in Southeast Wyoming with the 75th depicting
about 4 inches of snow. For the Nebraska Panhandle the 25th
percentile has 0 inches and the 75th percentile is 2 inches. The key
uncertainty is how fast we transition from rain to snow. For the
mountains it looks to be between 2 to 6 inches for Laramie and
Rawlins, and 5 to 10 inches for the Sierra Madre/Snowy mountains.
Wednesday, the low let jet intensifies slightly to 60knots on the
backside of the Low to give us some elevated winds with light snow
for Southeast Wyoming. The Nebraska panhandle doesn`t look like as
likely to see those elevated wind as there is strong rising motion
over the Panhandle which doesn`t typically favor those elevated
winds. However, they will still see the light snow in the morning.
Over the course of the day Wednesday, the Low pressure system will
slowly meander into the central and Northern plains as that
amplified ridge slowly moves east. By the evening Wednesday there
will be a brief break in precipitation as a weak transient ridge
moves overhead. This break doesn`t last long as another wave impacts
the Rocky mountains to rejuvenate our precipitation chances for the
region. This pattern begins to get more muddled as a low pressure
system gets dives down into the Southwestern portion and gets cut
off from the flow as a Rex Block forms over the Pacific NW and a
high pressure system builds off the Atlantic Coast helping to cutoff
the low and stalling it somewhere near the Intermountain west and
the Southwestern portion of the US (AZ and NM). Depending on when
and where this Low is can give us a little precipitation or a lot of
precipitation. The 00-06z runs of the global models play with this
band of heavy snow ranging from 6 to 12 inches. Keep in mind this is
a long way off so this total will fluctuate a lot until then but its
something to monitor for trends. The Euro maintains a Northern track
which puts the heaviest precip band over the I-80 corridor east of I-
25. The GFS has the system cutting off sooner and maintains a
southern track placing the band in Northern Colorado while only
giving us a couple inches. The Canadian is in the middle and keeps
the snow amount just under advisory levels for the same area. So the
resemblance of an agreement between the models is that a low
pressure system will be sandwiched and cut off from the flow by the
two areas of high pressure. For now this muddled pattern will be
monitored for trends and impacts as the models further resolve how
this system will play out this weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1142 AM MDT Sun Mar 30 2025

MVFR to IFR ceilings will affect terminals east of the Laramie
Range today. Additional showers and possibly a rumble of thunder
will affect CYS and SNY, with brief VIS lowerings in the
heaviest precipitation. General light snow or a rain snow mix is
possible at LAR and RWL for a few hours later this afternoon
with some very light preicp at BFF CDR and AIA as well. Expect
improving conditions late overnight and through the morning on
Monday.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until noon MDT today for WYZ114-116-
     117.
NE...None.

&&

$$

SHORT TERM...SF
LONG TERM...MM
AVIATION...MAC