205
FXUS65 KBOU 181053
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
453 AM MDT Tue Jun 18 2024

.KEY MESSAGES...

- Cooler Today and Wednesday with a chance of showers and a few
  storms.

- Scattered thunderstorms Thursday into Friday.

- Hot and drier through the weekend on into next week.

&&

.SHORT TERM /Through tonight/...
Issued at 306 AM MDT Tue Jun 18 2024

An upper level trough will move across the nrn Rockies today with SW
flow aloft in place.  At the sfc, a cold front was moving across the
plains early this morning.  As a result, highs today will be much
cooler than yesterday with readings mainly in the 70`s over nern CO.
As for precip chances, there is minimal MLCAPE across the plains as
better low level moisture will be to the southeast and south of
the area. However, some moisture will move into the higher terrain
where MLCAPE will be around 500 j/kg. Thus will keep in a slight
chc of storms mainly in the mtns and across South Park.

For tonight, the low level flow will increase from the east across
the plains.  This will allow for some increase in deeper low level
moisture. Meanwhile, it appears nrn CO will be on the south side
of a stronger upper level jet. Thus this could help produce some
shower activity overnight across parts of the plains with an isold
tstm or two. At this time still not clear where the best threat
of showers will be so have kept pops in the chc category
overnight.

&&

.LONG TERM /Wednesday through Monday/...
Issued at 326 AM MDT Tue Jun 18 2024

Models keep the CWA in southwesterly flow aloft Wednesday trough
Thursday night with upper troughing over the western U.S. and strong
upper ridging over the southeastern United States. The QG Omega
fields mostly have weak upward vertical velocity through the four
periods.  In the low levels, pressure and wind fields have
southeasterly surface winds on Wednesday with a Denver Cyclone
likely to develop. After that, normal diurnal wind patterns are a
good bet into Friday morning.

Looking at moisture, precipitable water values increase a bit
through the day Wednesday and by late afternoon most of the plains
have 0.90 to 1.15 inches in place.  By Thursday afternoon, values
are up a bit more into the 1.00 to 1.30 inches range.  Some CAPE is
progged Wednesday but it is mainly limited to the western half of
the CWA, with the highest values in the mountains and foothills.
CAPE is more widespread and values are more significant for late day
Thursday. Will mainly go with "scattered" pops or less late day
Wednesday and Wednesday night. Pops will be a tad higher for late
day Thursday with increased heating and somewhat better moisture.

For temperatures, Wednesday`s highs are below seasonal normals
for another day, then Thursday`s readings warm up some 5-10 C
from Wednesday`s.

For the later days, Friday through Monday, models finally show the
weak upper trough to push eastward across the CWA on Friday into
Saturday, then upper ridging builds in from the southeast and
south of Colorado into next week. Late day convection will be
"scattered" in the mountains and foothills, with less chances out
on the plains. High temperatures will be around 90 F on the
plains Friday, with above 90 F for the weekend and early next
week. Monday looks like the hottest day with highs in the 95 to
100 F range over the plains.

&&

.AVIATION /12Z TAFS through 12Z Wednesday/...
Issued at 446 AM MDT Tue Jun 18 2024

Have a well developed Longmont Anti-Cyclone this morning which
is enhancing low level easterly winds at DIA.  Expect winds will
gradaully decrease by 13z but stay easterly. Winds will stay
easterly thru the aftn and gradually increase by 19z.  Hi res
data wants to develop some high based showers after 21z thru
the evening hours, however,threat of tstms looks low at this time.
Ceilings with the showers could drop to 9000 ft or so. Winds this
evening and overnight will remain mainly easterly. May see some
stratus develop late tonight with MVFR ceilings after 10z.

&&

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

&&

$$

SHORT TERM...RPK
LONG TERM....RJK
AVIATION...RPK