347
FXUS65 KBOU 271958
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
158 PM MDT Mon May 27 2024

.KEY MESSAGES...

- Mostly dry tonight, with just the slightest chance of a shower
  or storm.

- Warm through the week.

- Limited late day storm coverage Tuesday, then higher coverage of
  showers and thunderstorms Wednesday, and potentially into
  Thursday and Friday. A few severe storms are possible on the
  plains with the highest threat on Wednesday.

&&

.SHORT TERM /Through Tuesday/...
Issued at 158 PM MDT Mon May 27 2024

Satellite shows some shallow cumulus developing. ACARS show a
weakening cap, but little if any MLCAPE is available (less than
200 J/kg). Thus, even if we do reach convective temp, don`t think
there`d be much more than virga around at this point. And most of
that would be over the Palmer Divide area south of Denver, and the
WY/NE border area where water vapor shows a little more moisture
availability.

For Tuesday, moisture values improve a little further with
precipitable water (PW) values coming up another 0.1 (mountains)
to 0.2 inch (plains). MLCAPE will also increase, with a few
hundred J/kg over the eastern plains. That said, it will take some
heating to break the cap, but that should be able to occur by late
afternoon across portions of the I-25 Corridor and Palmer Divide
area. We don`t think any of these storms would have much if any
severe potential given relatively limited instability, but a
couple stronger ones late in the day could produce small hail,
gusty winds, and brief moderate rainfall. High temperatures will
be near readings seen today - about 2-4 degrees above normal.

&&

.LONG TERM /Tuesday night through Monday/...
Issued at 158 PM MDT Mon May 27 2024

Not too many changes to the long-term forecast. An active early
summer pattern begins Wednesday through Friday with diurnal
showers and storms across the Front Range.

An upper level trough will push north of our area near the
US/Canada border, thus clipping the CWA and increasing mid-level
moisture along the foothills and plains Wednesday. Daytime
heating and weak instability will likely lead to scattered
thunderstorm and shower development Wednesday afternoon. Low level
southeasterly winds increase between 20-30kts Wednesday afternoon
east of the I-25 corridor. This combined with higher MLCAPE
values near 800-1200 J/kg will likely lead to a greater chance of
severe storms for the eastern plains through late Wednesday
evening especially below I-70 east. These storms could produce
hail, wind gusts up to 60 mph and brief heavy rainfall.

Coverage for showers and storms decreases Thursday due to moisture
exiting the region through northwest flow as an additional
shortwave trough is favored to develop southeast of northeastern
Colorado. Isolated to scattered chances (10-30%) exist mainly for
the foothills and plains through Thursday afternoon. Also, a cold
front develops along the Front Range foothills extending into the
plains Thursday. There is still some uncertainty in timing of the
front but with the potential for the front arriving late Thursday
morning, thunderstorm development may become limited. Still, there
is higher confidence in weak isolated showers versus
thunderstorms Thursday afternoon. Friday, there is lower
confidence in precipitation chances along the Front Range as
models differ in mid-level moisture back building from the
potential shortwave trough southeast. Knowing this pattern is
usually not favorable, decided to lower NBM PoPs but still keep
isolated to scattered chances. Zonal flow occurs Saturday and
diurnal chances of storms and showers should come as no surprise
once more favoring the mountains and foothills then decreasing in
coverage along the plains.

Warmer and drier conditions are expected Sunday through early next
week. Above normal temperatures are likely across the entire CWA.
This pattern may lead to elevated fire weather conditions depending
on fuel status.

&&

.AVIATION /18Z TAFS through 18Z Tuesday/...
Issued at 1158 AM MDT Mon May 27 2024

VFR conditions will persist through the TAF period. Easterly winds
have developed and will remain mostly east or ESE through 02Z.
Then, winds at KDEN and KAPA should gradually transition to light
south/southwesterly after 06Z, but can`t rule out a period of VRB
winds. Meanwhile, KBJC will likely turn more northwesterly.
Diurnal easterly winds can be expected again for Tuesday afternoon
after 18Z.

&&

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

&&

$$

SHORT TERM...Barjenbruch
LONG TERM...AD
AVIATION...Barjenbruch