Spot Forecast
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
751
FNUS75 KBOU 281227
FWSBOU
Spot Forecast for Lake John SWA Broadcast...Colorado DFPC
National Weather Service Denver/Boulder CO
627 AM MDT Wed Oct 28 2026
If conditions become unrepresentative...contact the National Weather
Service.
.DISCUSSION...
Gusty south and southwest winds are expected to persist through most
of the day. There will be a slight decrease in strength mid
morning, increasing again for the afternoon hours. Peak gusts will
approach 40 mph, but will mostly stay closer to 25 to 30 mph.
There will likely be occasional lulls in wind speeds, especially
in the mid to late morning, and these breaks in gusty conditions
could support brief drops in temperatures/rises in humidity that
are not reflected in the hourly trends below. Nonetheless, expect
minimum afternoon humidity values to fall close to 30% under
mostly clear sky conditions. Smoke dispersal will remain highly
favorable given the wind, with "Good" or better ventilation as
early as 1000 or 1100. Winds aloft will transport winds to the
northeast.
A high humidity recovery is forecast tonight, above 80-90%, together
with considerably weaker winds that will generally stay below 5-10 mph
most of the night. This will support notably colder temperatures, with
a hard freeze expected.
Thursday will bring drier and slightly warmer conditions, along with
a slight increase in cloud cover. Southwest winds are favored to
develop during the day, but with much lower speeds relative to
Wednesday. Thus, smoke dispersal will suffer, and it`s possible that
Poor ventilation will persist for the entire day. Winds Thursday
night will be light (around 5 mph). Humidity recovery Thursday
night will be around 85%. No precipitation is expected.
[** NOTE FOR REQUESTER: Recent wind direction observations from DFPC
Portable 1 appear suspect. Recommend contacting NWS Boulder upon
receipt of this spot forecast to discuss further **].
.REST OF TODAY...
Sky/weather.........Mostly sunny (15-25 percent) until 1700, then
partly cloudy (30-40 percent).
CWR.................1 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 53.
Min humidity........36 percent.
Wind (20 ft)........South winds 11 to 16 mph with gusts to around
32 mph until 1000, then southwest 11 to 19 mph
with gusts to around 31 mph.
Mixing height.......Below 1000 FT AGL until 0900, then 5400 ft AGL.
Transport winds.....Southwest 15 to 23 mph until 1100, then west 22
to 29 mph.
Smoke dispersal.....Poor until 1000, then good until 1100, then
very good until 1700, then good.
TIME (MDT) 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........12 21 25 10 18 16 14 12 18 23 36
Weather cov.....
Weather type....
Tstm cov........
CWR.............0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).0 0 0 0 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0
Temp............29 29 36 40 46 51 52 52 53 52 50
RH..............78 78 72 67 56 46 41 39 36 36 41
20 FT wind dir..S S SW SW SW SW SW SW SW SW SW
20 FT wind spd..14 13 13 13 15 16 18 18 17 15 12
20 FT wind gust.32 29 26 26 28 29 30 31 30 25 18
Mix hgt (kft)...0.5 0.6 2.0 3.5 4.4 5.2 5.3 5.8 5.7 5.1 4.2
Transp wind dir.SW SW W W W W W W W W SW
Transp wind spd.17 15 16 23 28 29 29 29 26 24 22
Vrate kt-ft/1K..8 8 28 70 106 129 134 146 131 107 81
SmokeDispersion.P P P G VG VG VG VG VG VG G
.TONIGHT...
Sky/weather.........Partly cloudy (25-35 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....Around 20.
Max humidity........96 percent.
Wind (20 ft)........Southwest winds 5 to 7 mph until 2100, then
south until 0400, then around 5 mph.
Mixing height.......Below 1000 FT AGL.
Transport winds.....Southwest 8 to 13 mph until 0300, then 8 to 10
mph.
Smoke dispersal.....Poor.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........32 42 48 41 35 34 26 33 26 16 15 14
Weather cov.....
Weather type....
Tstm cov........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).0 0 0 0 0 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0
Temp............47 40 37 35 33 30 29 27 26 25 23 22
RH..............47 59 64 69 75 85 85 88 88 88 92 96
20 FT wind dir..SW SW SW S S S S S S S S S
20 FT wind spd..6 5 5 5 5 5 5 5 5 5 3 3
20 FT wind gust.9 7 7 7 7 7 7 7 7 7 6 6
Mix hgt (kft)...0.8 0.5 0.5 0.5 0.5 0.5 0.6 0.5 0.5 0.5 0.5 0.5
Transp wind dir.SW SW SW SW SW S SW S SW SW SW SW
Transp wind spd.12 10 9 9 9 10 9 9 8 7 7 8
Vrate kt-ft/1K..8 5 4 4 4 4 4 4 4 3 3 4
SmokeDispersion.P P P P P P P P P P P P
.THURSDAY...
Sky/weather.........Mostly sunny (10-20 percent) until 0700, then
partly cloudy (35-45 percent) until 1200, then
mostly cloudy (45-55 percent) until 1300, then
partly cloudy (35-45 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 56.
Min humidity........25 percent.
Wind (20 ft)........Variable up to 5 mph until 1100, then south 5
to 13 mph with gusts to around 21 mph.
Mixing height.......Below 1000 FT AGL until 1000, then 3100 ft AGL
until 1200, then 6300 ft AGL until 1700, then
1400 ft AGL.
Transport winds.....Southwest around 8 mph until 0700, then 8 to 10
mph until 0900, then light until 1000, then
southwest 12 to 20 mph until 1700, then west
around 12 mph.
Smoke dispersal.....Poor until 1100, then fair until 1200, then
good until 1400, then very good until 1600,
then good until 1700, then poor.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........13 36 34 34 35 49 52 43 41 49 34 31
Weather cov.....
Weather type....
Tstm cov........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).0 0 0 0 0 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0
Temp............22 20 21 27 37 45 51 54 55 56 55 53
RH..............92 96 92 85 64 47 37 31 27 25 27 33
20 FT wind dir..S NE SW S S S S S S SW SW S
20 FT wind spd..3 3 2 2 3 5 8 9 10 9 8 5
20 FT wind gust.5 5 5 6 9 14 20 21 21 20 17 12
Mix hgt (kft)...0.5 0.5 0.5 0.5 1.7 3.5 5.1 6.2 6.8 6.3 5.1 1.4
Transp wind dir.SW SW SW SW S SW SW SW SW SW SW W
Transp wind spd.8 7 7 7 12 16 20 16 18 18 15 12
Vrate kt-ft/1K..4 3 3 3 17 49 87 86 109 100 66 14
SmokeDispersion.P P P P P F G G VG VG G P
$$
Forecaster...Pettett
Requested by...Sam Parsons
Type of request...PRESCRIBED
.TAG 2624578.1/BOU
.DELDT 10/28/26
.FormatterVersion 2.0.0
.EMAIL samuel.parsons@state.co.us