809
FNUS75 KBOU 032319
FWSBOU

Spot Forecast for Slack Wiess...USFS
National Weather Service Denver/Boulder CO
419 PM MST Wed Dec 3 2025

If conditions become unrepresentative...contact the National Weather
Service.

.DISCUSSION...Northwest flow aloft will increase brining gusty
west to southwest winds Thursday and Friday. Gusts to 30 mph
will be possible, mainly during the afternoon and evening hours.
This will lead to fair smoke dispersal during the afternoon hours
both Thursday and Friday.

.THURSDAY...

Sky/weather.........Mostly sunny (15-25 percent) until 1300, then
                    partly cloudy (25-35 percent).
CWR.................4 percent.
Chance of pcpn......5 percent.
Max temperature.....Around 22.
Min humidity........53 percent.
Wind (20 ft)........Southwest winds 10 to 15 mph with gusts to
                    around 23 mph until 1100, then 12 to 17 mph
                    with gusts to around 30 mph.
Mixing height.......Below 1000 FT AGL until 0900, then 2800 ft AGL
                    until 1700, then Below 1000 FT AGL.
Transport winds.....West 13 to 21 mph until 1300, then 15 to 23
                    mph.
Smoke dispersal.....Poor until 1200, then fair until 1600, then
                    poor.

TIME (MST)      8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........21  20  19  22  25  27  31  30  36  33
Weather cov.....                                    SCH
Weather type....                                    SN
Tstm cov........
CWR.............0   0   0   0   0   0   0   0   0   0
Chc of pcpn (%).0   0   0   0   0   0   0   0   0   5
Temp............8   13  16  19  20  21  22  20  20  16
RH..............80  67  64  60  59  54  53  58  57  64
20 FT wind dir..SW  SW  SW  SW  SW  W   W   W   SW  SW
20 FT wind spd..10  12  14  15  16  17  17  17  16  12
20 FT wind gust.17  20  23  24  28  29  29  29  26  22
Mix hgt (kft)...0.7 1.2 1.9 2.3 2.8 2.9 2.7 2.5 1.7 0.9
Transp wind dir.SW  W   W   W   W   W   W   W   W   W
Transp wind spd.13  15  17  20  21  23  23  23  20  15
Vrate kt-ft/1K..8   16  28  40  50  58  54  49  29  12
SmokeDispersion.P   P   P   P   F   F   F   F   P   P

.THURSDAY NIGHT...

Sky/weather.........Partly cloudy (30-40 percent) until 2300, then
                    mostly cloudy (65-75 percent). Slight chance of
                    snow until 2300, then chance of snow.
CWR.................8 percent.
Chance of pcpn......60 percent.
Min temperature.....Around 12.
Max humidity........84 percent.
Wind (20 ft)........Southwest winds 10 to 20 mph. Gusts up to 30
                    mph.
Mixing height.......1000 ft AGL until 1900, then Below 1000 FT AGL.
Transport winds.....Southwest 14 to 19 mph.
Smoke dispersal.....Poor.

TIME (MST)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........28  29  30  34  45  59  59  68  78  79  76  73
Weather cov.....SCH SCH SCH SCH SCH CHC CHC CHC CHC CHC CHC LKY
Weather type....SN  SN  SN  SN  SN  SN  SN  SN  SN  SN  SN  SN
Tstm cov........
CWR.............0   0   0   0   0   10  10  10  10  10  10  10
Chc of pcpn (%).20  20  20  20  20  40  40  40  40  40  40  60
Temp............15  15  12  12  13  13  13  13  13  12  13  13
RH..............70  70  76  73  70  70  73  73  76  80  80  80
20 FT wind dir..SW  SW  SW  SW  SW  SW  SW  SW  SW  SW  SW  SW
20 FT wind spd..12  13  14  14  14  14  14  13  13  13  12  12
20 FT wind gust.22  23  25  25  25  24  24  23  23  22  21  18
Mix hgt (kft)...1.0 0.6 0.6 0.6 0.6 0.6 0.7 0.8 0.9 0.9 0.8 0.8
Transp wind dir.SW  SW  SW  SW  SW  SW  SW  SW  SW  SW  SW  SW
Transp wind spd.15  16  16  16  16  16  17  17  18  18  18  18
Vrate kt-ft/1K..13  9   9   9   9   8   10  12  15  14  13  13
SmokeDispersion.P   P   P   P   P   P   P   P   P   P   P   P

.FRIDAY...

Sky/weather.........Mostly cloudy (70-80 percent). Snow likely
                    until 1100, then chance of snow.
CWR.................15 percent increasing to 24 percent late in the
                    afternoon.
Chance of pcpn......60 percent.
Max temperature.....Around 23.
Min humidity........77 percent.
Wind (20 ft)........Southwest winds 10 to 18 mph with gusts to
                    around 25 mph.
Mixing height.......Below 1000 FT AGL until 0800, then 2400 ft AGL.
Transport winds.....Southwest 15 to 24 mph.
Smoke dispersal.....Poor until 1100, then fair until 1500, then
                    poor.

TIME (MST)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........73  73  73  73  73  73  75  77  79  79  79  80
Weather cov.....LKY LKY LKY LKY LKY CHC CHC CHC CHC CHC CHC CHC
Weather type....SN  SN  SN  SN  SN  SN  SN  SN  SN  SN  SN  SN
Tstm cov........
CWR.............10  10  10  10  10  20  20  20  20  20  20  20
Chc of pcpn (%).60  60  60  60  60  40  40  40  40  40  40  40
Temp............12  12  13  15  18  20  21  22  23  22  21  22
RH..............84  84  84  84  80  77  77  77  77  81  84  81
20 FT wind dir..SW  SW  SW  SW  SW  SW  SW  W   W   W   SW  SW
20 FT wind spd..12  13  13  13  14  14  14  14  14  13  12  12
20 FT wind gust.18  21  21  21  22  22  22  22  22  21  18  23
Mix hgt (kft)...0.9 0.9 1.0 1.5 2.0 2.5 2.5 2.5 2.4 2.0 1.6 1.2
Transp wind dir.SW  SW  SW  SW  W   W   W   W   W   W   SW  SW
Transp wind spd.17  16  15  18  21  24  24  24  24  22  21  18
Vrate kt-ft/1K..13  13  13  23  36  52  52  52  51  39  28  19
SmokeDispersion.P   P   P   P   P   F   F   F   F   P   P   P


$$
Forecaster...Meier
Requested by...Matthew Polley
Type of request...PRESCRIBED
.TAG 2526998.0/BOU
.DELDT 12/03/25
.FormatterVersion 2.0.0
.EMAIL matthew.polley@usda.gov