657
FXUS65 KBOU 200929
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
329 AM MDT Thu Jun 20 2024

.KEY MESSAGES...

- Warmer today with a good chance of afternoon thunderstorms. A
  few severe storms will be possible mainly across the plains.
  Locally heavy rainfall will occur in some areas as well.

- Scattered to likely showers and thunderstorms on Friday. A few
  could be strong to severe, and also produce locally heavy rain.

- Hotter and drier this weekend into next week.

&&

.SHORT TERM /Through tonight/...
Issued at 300 AM MDT Thu Jun 20 2024

A disturbance embedded in SW flow aloft is moving across the area
early this morning.  Most of the shower and tstm activity with this
feature will move across srn areas of CWA thru 12z.

For later today, sfc low pres will develop along the front range
with increasing southerly low level flow across the plains. Deeper
low level moisture has already overspread the plains. Overall,
showers and storms will increase by early aftn over the higher
terrain. Outflow booundaries from this activity will trigger
additional development by mid aftn along the I-25 Corridor which
will then spread across the plains by late aftn into the early
evening hours. MLCAPE over the plains will be in the 1500-2000
j/kg range this aftn with a favorable enough shear profile for a
few svr storms. Meanwhile, storms over the higher terrain may
produce a few wind gusts up to 60 mph as well. Although storms
will be moving, they could produce from 1.00 to 1.5 inches of rain
in a rather short period of time as well. As far as highs today,
readings will be warmer with readings in the 85 to 90 degree range
over nern CO.

For tonight,  there is some indication of a another disturbance
moving across overnight. This feature may allow for the
development of additional shower and tstm development especially
over the higher terrain.

&&

.LONG TERM /Friday through Wednesday/...
Issued at 330 AM MDT Thu Jun 20 2024

Upper ridging returns to dominate the CWA`s weather by Friday.  This
will continue well into next week, at least.  Southwesterly flow
aloft is progged for the forecast area Friday into Saturday,  It
becomes more zonal Saturday afternoon and night.  The QG Omega
fields indicate weak upward synoptic scale energy for the CWA Friday
and Friday evening.  Then weak downward vertical velocity is progged
Saturday and Saturday evening, with benign conditions after that.
There looks to be weak surge of slightly cooler air and upslope
flow on Friday, at least for the plains.

Models continue to show plenty of moisture for the CWA on Friday
with precipitable water values in the 0.80 inch to 1.50 inches range
in the afternoon and evening. Again, there is fairly decent CAPE
progged Friday, especially over the northern and eastern border
areas of the CWA. Moisture looks to decrease on Saturday with the
PWs dropping into the 0.50 to 1.00 inch range. That along with the
weak subsidence should lessen pops from Friday`s numbers.

For temperatures, Friday`s highs look to be close to this
afternoon`s expected highs, perhaps 0-1.5 C cooler.  Saturday`s
highs are 1.5-4.0 C warmer than Friday`s.

For the later days, Sunday through Wednesday, models show upper
ridging over Colorado all four days with the center of the upper
high just sough of the state. The synoptic scale energy is benign
to weak subsident all four days. There is enough moisture for
rounds of late day showers and thunderstorms, with the best
chances in the mountains and foothills. Temperatures look to be
above seasonal normals all four days, with highs in the mid 90s
to 100 degree F for the plains each afternoon.

&&

.AVIATION /06Z TAFS through 06Z Friday/...
Issued at 1117 PM MDT Wed Jun 19 2024

Winds were southerly late this evening and should reman so
overnight.  As long as they stay south stratus development
is unlikely. There is a disturbance over swrn CO moving
northeast. At this time it appears any shower and thunderstorm
activity with this feature overnight would stay to the south and
east of DIA. On Thu, will see south winds increase thru midday
which will continue thru the aftn. Sct tstms develop will
develop after 20z.  A few stronger storms will be possible
with hail, gusty winds and heavy rain thru 00z. Ceilings and
visibility may briefly drop to MVFR as these storms move across.

&&

.HYDROLOGY...
Issued at 300 AM MDT Thu Jun 20 2024

Although storms will be moving this afternoon and evening, the
threat of heavy rainfall will be greater with an elevated threat of
flash flooding in the burn scars. Across the plains, where rather
high precipitable water levels will be in place, rainfall amounts
of 1 to 1.5 inches in a short period of time will certainly be
possible with isolated higher amounts.

There could also be decent rainfall late day Friday, and the burn
scares will be most susceptible to flash flooding. Pops will be
lower Saturday and Sunday so the flash flooding threat will be
decreased somewhat those days.

&&

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

&&

$$

SHORT TERM...RPK
LONG TERM....RJK
AVIATION.....RPK
HYDROLOGY....RJK/RPK