FXUS65 KCYS 241741

AFDCYS



Area Forecast Discussion

National Weather Service Cheyenne WY

1141 AM MDT Fri Apr 24 2026



.KEY MESSAGES...



- A Red Flag Warning is in effect for the I-80 corridor from

  Cheyenne to Sidney this afternoon due to low humidity and 

  breezy conditions.



- Isolated to scattered showers and snow showers possible this

  afternoon and evening due to a stationary front draped across

  the region.



- Easterly, upslope flow develops Saturday, leading to

  increasing precipitation chances for much of the region.



- Relatively cool and wet weather is expected for the weekend

  and early next week.



&&



.SHORT TERM /THROUGH SATURDAY NIGHT/...

Issued at 211 AM MDT Fri Apr 24 2026



Upper-level trough remains in place across the region today as the 

broad, upper-level trough spins over southern Canada. Poor vorticity 

advection at 500mb will prevent this trough from quickly moving off 

to the east, therefore, cooler and cloudier weather will continue. 

With the upper-level system struggling to push eastwards, the 700mb 

low will continue to spin across southern Canada with a few 

North/South meandering throughout the day. Therefore, elevated 

height gradients are anticipated to remain across the CWA, favoring 

breezy conditions for another day. The 700mb low will stay largely 

north enough to prevent a very strong 700mb jet from developing, but 

the jet is anticipated to peak around 45kts. With modest downward 

omega values progged by the GFS, breezy conditions are expected to 

develop across western portions of the CWA throughout the day today. 

With the weaker 700mb jet, high winds are not expected, but gusts 

over 40 mph cannot be ruled out at this time. Near the surface, a 

stationary front looks to develop as the 700mb low continues to spin 

in one location. As a result, ongoing precipitation development 

along the front is expected, though widespread precipitation is not 

anticipated at this time. Precipitation chances range between about 

20 to 45%, with the highest values in northern portions of the CWA 

where better ascent may develop. Increasing cloud cover this 

afternoon combined with the stationary front draped across the 

region will lead to a cooler day, with widespread high temperatures. 

Northern portions of the region will see temperatures peaking in the 

mid-40s, while all other locations with see 50s and 60s, depending 

on exactly where the stationary front sets up this afternoon. Right 

now, the front is expected to setup along a line from about Douglas 

to Wheatland to Sidney. As a result, many locations along Interstate 

80 from Cheyenne to Sidney will see significant drying this 

afternoon, with humidity values dropping to the 10-15% range and 

winds gusting up to 35 mph. Red Flag Warnings remain in effect for 

this area through 8 PM tonight. As precipitation slowly migrates 

southerly, Red Flag conditions are expected to improve with the 

increasing moisture.



Saturday looks to be a little more active as upper-level propagation 

begins to pick up as another upper-level trough moves onshore in 

southern California. Multiple vorticity maxima will eject out ahead 

of the incoming trough, resulting in synoptic ascent across the 

region and a shortwave trough developing at 500mb and ejecting 

through the region southwest to northeast. 700mb flow remains mostly 

southerly across the region Saturday as a 700mb shortwave propagates 

southeast of the CWA. Luckily, with largely southerly flow in the 

lower-levels, increasing moisture is expected across the region. 

Additionally, a backdoor cold front will push into the region from 

the east, leading to largely easterly, upslope flow along and east 

of the Laramie Range. Precipitation chances will increase into the 

60-70% range Saturday night. Mostly rain is likely east of the 

Laramie Range where temperatures will be a touch warmer overnight 

Saturday, with rain/snow then snow expected west of the Laramie 

Range where temperatures will be cooler. Upslope flow will continue 

for much of the day and into the overnight hours. Total 

precipitation accumulation looks to be quite decent at this time, 

potentially the most precipitation we have seen in a while. However, 

it will still be nowhere near enough to put a dent in the drought. 

Luckily, an active pattern is expected to continue into the long 

term forecast.



&&



.LONG TERM /SUNDAY THROUGH THURSDAY/...

Issued at 211 AM MDT Fri Apr 24 2026



A mid level disturbance is expected to make its presence known on 

Sunday as it moves in from Southern California. At the surface we 

should be behind a cold front with temperatures in the 30s and 40s 

over much of the area. A warm nose around the 650 mb layer will 

promote rising motions above the shallow cool layer and a saturated 

profile will increase our rain/snow chances. Cyclogenesis is 

expected to our south and will keep the cold air advection going

through the day. So, expect cool and wet conditions in other 

words. The Snowy and Sierra Madre ranges may pick up 2-4 inches 

of snow. Most of the are around 0.15-0.25" and perhaps higher 

amounts in the southern Nebraska Panhandle where some lucky 

spots could receive a half inch in rainfall. This system 

departs to the northeast quickly overnight. Periods of snow 

showers may continue through the morning hours as temperatures 

hover around the freezing level over much of the area. We keep 

this seasonable weather trend going into Monday, which may end 

up slightly cooler than Sunday. Chances of precip do decrease 

during the day, but we get another round of increased PoPs in 

the overnight hours as another upper level vorticity maximum 

passes over the area, courtesy of the trough that's been in 

place over Canada since last Thursday. We may pick up another 

tenth of an inch of rainfall with this disturbance and the 

mountain ranges another 2 inches or so of snow. We will gladly 

take what we can get to improve our current dry conditions and 

buffer ourselves from the next drying spell. Winds may also 

increase as this shortwave moves through Tuesday. Presently 

there are no concerns of high winds. Persistent troughing seems 

to be a more favored outcome going into Wednesday and to end out

the forecast period. Therefore, expect generally cool and wet 

conditions.



&&



.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...

Issued at 1128 AM MDT Fri Apr 24 2026



West southwest flow aloft will continue, while a cold front

passing this afternoon and evening brings unsettled weather 

through the period.



Wyoming TAFS...High confidence in ceilings lowering to 5000 feet

this evening, then to 1500 to 2500 feet after midnight, then

improving to 5000 feet Saturday morning. Pressure gradients

suggest winds gusting to 48 knots at Rawlins and Laramie until

03Z, then to 25 knots at Laramie from 09Z to 15Z, and gusting to

35 knots at Cheyenne until 07Z.



Nebraska TAFS...For Chadron and Alliance, high confidence in

ceilings near 4500 feet through 09Z, with occasional showers

from 18Z to 22Z reducing visibilities to 6 miles and ceilings to

2500 feet, then ceilings near 2500 feet from 09Z to 15Z with

visibilities in fog reduced to 2 miles, then ceilings near 4000

feet after 15Z Saturday. Winds gusting to 25 knots until 01Z.



For Scottsbluff and Sidney, high confidence in scattered to

broken clouds from 4000 to 10000 feet with occasional showers at

Scottsbluff from 20Z to 00Z, and ceilings near 2500 feet at

Sidney from 05Z to 15Z. Winds gusting to 32 knots at Scottsbluff

until 04Z, and to 37 knots at Sidney until 15Z Saturday. 



&&



.CYS WATCHES/WARNINGS/ADVISORIES...

WY...Red Flag Warning until 8 PM MDT this evening for WYZ430-431.

NE...Red Flag Warning until 8 PM MDT this evening for NEZ437.



&&



$$



SHORT TERM...AM

LONG TERM...RV

AVIATION...RUBIN