101
FXUS65 KBOU 312102
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
302 PM MDT Fri May 31 2024

.KEY MESSAGES...

- Chance of more storms through tonight, a few could be severe
  with the greatest threat over the Palmer Divide into East
  Central Colorado.

- Severe storm threat over eastern plains on Saturday.

- Low 90s possible for highs over the plains on Sunday.

&&

.SHORT TERM /Through Saturday/...
Issued at 233 PM MDT Fri May 31 2024

Surface observations show a convergence line extending from the
Palmer Divide east-northeast across Washington County. Expect
storms to form along the boundary later this afternoon. With ML
CAPE of 1000-1500 J/kg and 0-6km Bulk Shear around 40 knots,
supercell thunderstorms with large hail and strong winds will be
possible. For the Front Range Urban Corridor, soundings show the
airmass should stay capped through most of the afternoon. Better
chance for storms will be this evening, if temperatures can warm
into the lower to mid 70s, which will help break the cap. Also, if
a strong outflow boundary from convection off to the east is
thrown westward, it could kickoff convection as well. Another
possible source of lift for storms will be the right entrance of a
speed max moving across northern Colorado and southern Wyoming.
If storms develop they could become severe as well with ML CAPE
climbing to 1000-1500 J/kg. Models generally agree storms form
along the boundary to the southeast of Denver. For the rest of the
area, not much model agreement if and where storms will form late
this afternoon through tonight, so forecast confidence is low.

For Saturday, another round of afternoon/evening thunderstorms is
expected. Mostly clear skies will prevail Saturday morning,
allowing temperatures to warm into the lower 80s by early
afternoon. A wave embedded in the westerly flow aloft should kick
off weak showers and thunderstorms over the high country by early
afternoon. This activity will progress eastward through the day. A
dry line/surface trough sets up over eastern Colorado, roughly
from Fort Morgan to Limon. Strong to severe storms are expected
along and east of the dry line with ML CAPE up to 2000 J/kg and
good shear. Large hail and damaging winds will be possible with
severe thunderstorms.

&&

.LONG TERM /Saturday night through Friday/...
Issued at 301 PM MDT Fri May 31 2024

Models have zonal flow aloft over the CWA Saturday night with
flat upper ridging Sunday. There will be weak northwesterly flow
aloft Sunday night into Monday night. There is weak upward
synoptic scale energy late Saturday night through Sunday night and
again Monday night. The low level winds look to be normal diurnal
patterns through the period.

Moisture-wise, is is pretty dry, with he best precipitable water
values and dew point readings over the far eastern border areas. It
seems the models are not quite as dry as they were previously,
especially for Monday. CAPE-wise, there is still some over the
far eastern plains Sunday evening early. On Monday, the best CAPE
is over the far eastern border late in the day. Will leave the
limited pops in for the eastern plains Saturday evening, and again
for the northern and eastern border areas late day Sunday. Monday
looks pretty dry with just isolated storms for the high mountains
for now. Temperatures look to heat up pretty good for Sunday and
Monday, with Sunday`s highs 3-6 C warmer than Saturday`s highs.
Monday highs are close to Sunday`s. Denver could see it`s first 90
F degree reading on Sunday.

For that later days, Tuesday through Friday, upper ridging seems to
dominate the weather for the CWA.  Pops will be sparse, with the
best chances in the high country.  Temperatures look to stay above
seasonal normals.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1132 AM MDT Fri May 31 2024

Low stratus clouds will give way to stratocumulus clouds after
18Z with ceilings slowly rising in the 2500-5000 foot range. Best
chance for thunderstorms will be to the south and east of DEN
where less cloud cover will allow temperatures to warm and help
destabilize the airmass. Still a chance for a storm near DEN and
will continue with the VCTS beginning at 23Z. Threat for storms
ends in the 04-06Z window. Another round of storms are expected
Saturday, beginning 19-20Z. There`s a chance for low clouds
09-15Z, though they are expected to stay to north of the Denver
area.

&&

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

&&

$$

SHORT TERM...Meier
LONG TERM....RJK
AVIATION.....Meier