FXUS65 KBOU 200726
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
126 AM MDT Wed May 20 2026

.KEY MESSAGES... 
 
- Unsettled Tuesday through Friday with scattered to numerous
  showers and a few storms.
 
- Warming and drying trend for the weekend. 

&&

.DISCUSSION /Through Tuesday/...
Issued at 109 AM MDT Wed May 20 2026

Cooler temperatures and rain chances are expected to continue
through the workweek. An upper level trough will remain to our 
west/northwest through Thursday. Ahead of the trough, we'll see 
decent large scale lift. And with the moisture already present 
thanks to the rain the past few days, this will be enough to 
produce some scattered showers and thunderstorms during this time.
For today, instability is on the lower end (MLCAPEs 400 J/kg or 
less), so we're not expecting any severe storms this afternoon. 
The one thing we will need to keep an eye on the potential for 
landspouts. High res models have a Denver cyclone developing near 
the urban corridor this afternoon and we do have some weak 
surface CAPEs in that area, so landspouts are not out of the 
question. For Thursday, coverage and intensity of storms look a 
bit higher. Moisture will be ushered into the area at the surface,
QG lift ahead of the trough will be stronger, and we could see 
some breaks in the clouds in the late morning allowing for some 
surface heating and increased lapse rates/instability for 
Thursday afternoon. The highest chance of stronger storms will be
in our southeastern counties where the better shear and 
instability overlap. Right now, the main hazard looks like large 
hail, but we can't rule out an isolated tornado or strong winds as
well. 

The upper level trough will move over the area and off to the 
northeast overnight Thursday into early Friday. A cold front will
also move through overnight, dropping temperatures a few degrees 
for Friday. Rain chances will continue on Friday as a secondary,
weaker trough develops to our northwest and moves over the area 
late Friday into Saturday. Coverage and intensity of showers and
storms will be lower than what we're expecting on Thursday. 

After that secondary trough moves through, upper level ridging 
will start to build over the area. A warming trend will begin on 
Saturday, with highs reaching into the upper 80s for portions of 
the plains by Monday. The warming trend will be halted on Tuesday 
as another trough approaches from the west, cloud cover increases,
and precip chances return to the mountains and potentially the 
plains. 

&&

.AVIATION /06Z TAFS through 06Z Thursday/...
Issued at 1143 PM MDT Tue May 19 2026

Light rain and mist will continue near the TAF sites through the
early morning. Rain will likely clear out of the KBJC area first
and KAPA last. We'll see a brief break in rain chances in the mid
to late morning, before they return. Showers and storms are
expected to form in the area around 17Z to 19Z and then progress
eastward over the next couple of hours. This will be the best 
chance of showers and storms. There is potential for some 
lingering rain after the initial push, but models are starting to 
trend further south with that activity, so the best chance for 
additional rain in the afternoon and evening will be at KAPA. MVFR
CIGs are present this evening and will continue through tomorrow 
morning, before they start to lift around 14Z to 16Z to low end 
VFR for the afternoon (4000ft to 6000ft). 

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...AP
AVIATION...AP