FXUS65 KCYS 020540

AFDCYS



Area Forecast Discussion National Weather Service Cheyenne WY 1140 

PM MDT Tue Jul 1 2025



.KEY MESSAGES...



- There is a Marginal to Slight Risk of strong to severe 

thunderstorms  this afternoon for portions of western Nebraska and 

far   eastern Wyoming.



- Warm temperatures and daily chances for PM showers and 

thunderstorms will continue late this week and into next  weekend.



&&



.SHORT TERM /THROUGH THURSDAY/...

Issued at 1249 PM MDT Tue Jul 1 2025



A mid to upper level shortwave will kick off thunderstorms this 

afternoon. Most of the Panhandle is in a Marginal Risk as dewpoints 

and shear are more favorable in that area. The far eastern portion 

of the panhandle of our CWA is in a slight as the thunderstorms are 

likely to intensify the further east the storms travel. Effective 

shear looks to range between 25 to 35kts with 1000-2000 joules of 

CAPE. These storms if they do develop are likely to be messy and 

pulsy as the shear and mid level lapse rates of 7.5C are quite 

lackluster. However, looking at model soundings severe winds and 

hail look to be the main threats as the classic inverted v soundings 

are displayed by the models. Later in the evening, a developing low 

level jet may enhance this thunderstorm activity, but most of the 

activity may be moving into central Nebraska by then. 



For Wednesday and Thursday, a pretty typical summer weather pattern 

sets up across the region as a slow moving upper level ridge moves 

east of the area. High temperatures will remain in the 80s west of I-

25, and upper 80s to mid 90s east of I-25.

Secondary 590 dm ridge axis will push into the area Wednesday.

With increasing midlevel subsidence and the lack of any notable 

forcing, kept mention of precipitation west of the Laramie Range. 

Showers and thunderstorms will return to most of the region on 

Thursday as a broad eastern Pacific trough moves into the Great 

Basin Region and finally into the Intermountain West Thursday 

afternoon. This feature is expected to bring some subtropical 

moisture to the area as PWATs increase between 1.00 to 1.50 inches. 

Continued to increase POP across southeast Wyoming with some heavy 

rainfall possible. High temperatures will be slightly cooler 

Thursday afternoon due to cloud cover, but still near or slightly 

above average for this time of the year.



&&



.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...

Issued at 455 AM MDT Tue Jul 1 2025



Models show the pacific upper level trough continuing to lift 

northeast across the area Friday with another round of showers and 

thunderstorms. Thunderstorm coverage is forecast to lower this 

weekend due to the lack of forcing as weak zonal flow develops 

across the Intermountain west and across the Rocky Mountain Region. 



Temperatures remain in the upper 70's to the mid 80's across the 

forecast area. 700mb temperatures stay around 16 celsius which 

translate surface temperatures into the low to mid 80's for the 

lower elevations and upper 70's to low 80's for our more mountainous 

regions.



As we head into next week, models show another slow warming trend as 

a 595 to 600dm upper level high develops near the four corners 

region. The position of this high is a bit far south, so any 

shortwave activity digging south of of Canada will be enough to 

trigger showers and thunderstorms each afternoon. Kept thunderstorms 

in the forecast Monday and Tuesday as all models do not show this 

upper level high drifting northward until the middle of next week.



&&



.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...

Issued at 1140 PM MDT Tue Jul 1 2025



Shower and thunderstorm activity has ended for the night with skies 

becoming mostly clear through early Wednesday morning. Upper level 

ridge axis will build over the area Wednesday resulting in less 

coverage of showers and thunderstorms Wednesday afternoon into 

Wednesday evening. 



HAZARDS/WEATHER TRENDS: VFR conditions will prevail over the next 24 

hours. Another round of showers and possible thunderstorms are 

forecast for Wednesday afternoon, but should mainly impact KRWL and 

KLAR. Further east, can't rule out some shower activity and an 

embedded thunderstorm, but confidence is too low to include for KCYS 

and the western Nebraska terminals. 



&&



.CYS WATCHES/WARNINGS/ADVISORIES...

WY...High Wind Watch until 6 PM MDT this evening for WYZ109-110.

NE...None.



&&



$$



SHORT TERM...TJT/MM

LONG TERM...TJT/MM

AVIATION...TJT