FXUS65 KBOU 262109

AFDBOU



Area Forecast Discussion

National Weather Service Denver/Boulder CO

309 PM MDT Thu Jun 26 2025



.KEY MESSAGES...

 

- Hot Friday and Saturday with isolated afternoon storms.



- Cooler Sunday and Monday with higher coverage of storms and a

  threat for some of these storms to be strong to severe. 



&&



.DISCUSSION /Through Thursday/...

Issued at 220 PM MDT Thu Jun 26 2025



Water vapor satellite shows dry air over Colorado with southwest

flow aloft. There is some weak subsidence that is limiting

convection this afternoon. However, a few stray storms are forming

over the Palmer Divide and east to northern Lincoln County. High

resolution models are also starting to come into better agreement

that showers will form over the foothills late this afternoon and

into the evening and these showers will move over the I-25

corridor this evening. Brief moderate rain with gusty winds will

be possible with these showers. PoPs were increased to get a

mention of showers in the forecast this evening. 



Temperatures aloft will increase on Friday as light zonal flow

aloft will be in place. This will allow high temperatures to the

reach the low 90s across the I-25 corridor and plains. Model

guidance also suggests a weak low level convergent boundary will 

form generally from Deer Trail to Julesburg. Isolated storms will 

form along this boundary by the late afternoon. Soundings show a 

large boundary layer up to around 600 mb with dry adiabatic lapse 

rates. This suggests strong wind gusts up to 60 mph will be 

possible with the strongest storms especially north and east of 

Akron. Elsewhere, a few light showers and weak storms could form 

over the higher terrain and move onto the adjacent plains. 



Saturday will be very similar to Friday as hot temperatures and

isolated storms will again be possible. Gusty winds will be the

main threat from these storms. 



A cold front seems likely to move through the northeast plains on

Sunday bringing northeast winds. The majority of guidance 

indicates dew points may be in the 60s and upper 50s behind this 

front. Given the upslope winds and moderate instability, it is

expected that storm coverage will increase with 30-40% coverage.

An upper level jet will pass to the north of Colorado on Sunday

and may help to increase the deep layer shear close to the WY/CO

and NE/CO borders. Some storms may be strong to severe in far

northern Colorado with large hail and damaging wind gusts the

primary threat. 



Monday will have east-southeast winds across the plains with

healthy dew points. Moderate instability will be under a strong

cap due to a ridge and warm temperatures aloft. The upslope flow 

may help to generate storms in the foothills but it is uncertain 

if the storms will be able to survive on the plains. Monday will 

be the coolest day of the 7 day forecast. 



A ridge aloft will strengthen on Tuesday and Wednesday and highs

will increase to normal. Isolated storms will likely develop over

the higher terrain each day. 



&&



.AVIATION /18Z TAFS through 18Z Friday/...

Issued at 1158 AM MDT Thu Jun 26 2025



VFR conditions expected through the TAF period. Light winds

today expected to increase out of the southeast in the late

afternoon. Recent high resolution model runs have been more

consistent in showing showers over the terminals this evening.

While these are unlikely to impact the terminals, it is possible

that wind gusts up to 25 knots occur. There will be normal

drainage flow tonight and light winds Friday morning. In the

afternoon on Friday, storms to the southeast of Denver will likely

push an outflow boundary through that has moderate southeast

winds with gusts up to 30 knots. 



&&



.BOU WATCHES/WARNINGS/ADVISORIES...

None.



&&



$$



DISCUSSION...Danielson

AVIATION...Danielson

