Sidney, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

869
FXUS65 KCYS 242339
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
539 PM MDT Sun May 24 2026

.KEY MESSAGES...

- Widely scattered showers and isolated thunderstorms in the
  afternoon and evening will bring the potential for localized
  strong, gusty winds for both Sunday and Monday.

- Near record high temperatures will continue through Tuesday.

- A stormier weather pattern will setup on Tuesday and continue
  through the remainder of the week with daily chances for PM
  showers and thunderstorms.

- Increasing potential for strong to severe thunderstorms is
  being monitored for Wednesday through Friday.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 130 PM MDT Sun May 24 2026

Summer weather is back across the area today as upper level
troughing that has dominated most of the last week is replaced by a
modest ridge. While temperatures have warmed to values about 10
degrees above average today, this is not a very clean ridge. A
jumbled mess of 500-mb vorticity continues to translate over the
central and northern Rockies on top of the ridge aloft. While the
boundary layer remains quite dry this afternoon, moisture aloft is
beginning to increase as Pacific moisture is advected inland from
the west. Cloud cover will increase from west to east this
afternoon and evening. Weak synoptic lift in place of modest
instability (100 to 300 J/kg SBCAPE over the High Plains and 300
to 700 J/kg in Carbon and Albany counties) will also support
increasing coverage of high based showers and isolated
thunderstorms. Soundings across the area show a deep inverted-v,
but ample moisture aloft should prevent today`s activity from
being completely dry. Brief downpours are more likely west of
the Laramie Range. Further east, expect rainfall to be more
limited as rain drops will need to travel through a much deeper
and drier boundary layer. The primary hazard today will be dry
microbursts (or dry-ish microbursts west of the Laramie range)
thanks to the warm temperatures and dry boundary layer. DCAPE is
already substantial, around 600 to 800 J/kg west of I-25 and
800 to 1200 J/kg east of I-25. These values may climb by a few
hundred J/kg over the next few hours too. The axis of the very
subtle upper level shortwave will not really move overhead until
around midnight tonight. As a result, showers will probably
continue well into the evening hours tonight. After sunset, the
surface will decouple from the well-mixed boundary layers aloft,
which may set the stage for a few heat bursts over the High
Plains this evening. Most storms will produce wind gusts in the
40 to 55 mph, but a few gusts over 60 mph are certainly
possible.

Monday will transition into a different weather pattern that will
prevail for most of the week ahead. A powerful upper level closed
low will begin to dive into the Pacific northwest on Monday, pushing
the ridge aloft east of the area and into the central Plains.
Southerly flow aloft will increase in between the two, pulling
improved moisture northward in a pseudo-monsoonal pattern. The
warmth will peak on Monday with NAEFS mean 700-mb temperatures
around +10 to +12C across the area. Expect highs to range from
the mid 70s in Laramie and Rawlins up to the lower 90s in the
Nebraska panhandle. Nebraska locations will be within a few
degrees of daily record highs. As moisture arrives from the
south in the early afternoon hours, another round of widely
scattered showers and isolated thunderstorms will kick up,
bringing another chance for dry microburst activity. NBM PoPs
remain too low over the High Plains as they have for the last
several days, so slight chance (20%) PoPs were maintained from
the previous forecast for Monday afternoon and evening.

While Monday will feature a very weak pressure gradient and thus
light winds across the area, this will change heading into Tuesday.
The powerful upper level trough will dive southward, taking on a
negative tilt underneath a blocking ridge which will amplify over
the northern Plains. Nearly vertically stacked, strong southerly
flow will increase as pressure falls to the west, and rises to the
east. Integrated Water Vapor transport values per the NAEFS mean are
around the 90 to 97.5 percentile, pushing precipitable water over
the climatological 90th percentile. Over the Plains, warm and breezy
conditions will continue with highs a touch warmer than Monday north
of the North Platte River, and a touch cooler to the south. While
dewpoints will be improving with the southerly moisture fetch, the
warm temperatures will keep RH fairly low. Further west, forecast
soundings show near saturation throughout the column with ample
moisture moving in. Another vort-max is expected to be pulled up
from the south, moving into the area with peak-heating in the early
afternoon hours. This will initiate widespread showers and isolated
embedded thunderstorms (instability looks limited) over Carbon and
Albany counties during the early afternoon hours, and continuing
through the evening. This will spread east of I-25 in the late
afternoon and evening, but coverage to the east will be much more
limited.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 130 PM MDT Sun May 24 2026

The upper-level low dropping south will continue its
progression Wednesday, but starts to become cutoff from the flow mid-
day Wednesday. The low looks to be cutoff over Nevada, with strong
southerly flow across the CWA Wednesday through the rest of the
week. This low will remain cutoff and spinning over Nevada until
Friday when it gets absorbed back into the flow by the next incoming
strong trough. However, with this cutoff low progged to spin over
Nevada for several days, a very wet pattern is anticipated Wednesday
onwards, due to continued synoptic ascent and support downstream of
the churning upper-level low. This especially true with 700mb and
surface flow remaining strongly southerly through Friday when a weak
front tries to push through. With 700mb and surface flow remaining
southerly, warm, moist air will continue to advect into the region
leading to a warm week ahead that might event feel a touch muggy!
With warm, moist air and synoptic ascent nearby, daily afternoon
showers and storms will be possible, with Wednesday looking more
favorable for stronger storms across the region. This cutoff low
pattern looks to come to an end for next weekend, as cooler, more
seasonable air starts to the return to the region ahead of the upper-
level trough pushing through. Thursday into Friday, The spinning
upper level low looks to eject a surface low to increase the amount
of forcing on Friday. Each of the global models puts the area of the
most unstable CAPE in a different area (which is to be expected) but
given those values range between 1500 to 2500 Joules, Friday could
be signaling a particularly explosive environment and with the right
dynamics and spin all hazards could be possible at the end of the
work week.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1738 PM MDT Sun May 24 2026

Some stronger showers are north of KLAR and near the CO/WY
border near the Snowy Mountain Range. Otherwise not much rain
has been hitting the ground so VCSH was used and any -TSRA or
-RA was taken out of the TAFs. not quite sure if the showers
 will make it to the Nebraska Border as the showers are
 weakening and dissipating before reach KBFF. Will amend as
 needed but not to hopeful that any of the stronger showers will
 make it through the evening.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

$$

SHORT TERM...MN
LONG TERM...MM/AM
AVIATION...MM