Spot Forecast
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
189
FNUS75 KBOU 231203
FWSBOU
Spot Forecast for Forsythe II - Unit 44...USFS
National Weather Service Denver/Boulder CO
603 AM MDT Thu May 23 2024
If conditions become unrepresentative...contact the National Weather
Service.
.DISCUSSION...Observations across the Boulder county foothills
suggest a pretty strong surface inversion has developed this
morning, with the RAWS site at 8000 feet about 15 degrees cooler
than surrounding sites a few hundred feet higher. Initial
conditions in the first few hours are a blend of obs between
8000-8500ft.
Today should be warmer and windier for the spot location as
stronger westerly flow develops. Main uncertainty is with how low
RH gets this afternoon. This morning`s recovery was slightly
better than forecast at the RAWS but surrounding sites were
significantly drier above the inversion. Given that RH has been
consistently lower than guidance the past couple of days, the spot
forecast here calls for RH to bottom out near or just below 20%
which is drier than any model guidance. Winds are also expected to
increase quickly this morning into the afternoon, with sustained
winds around 10-20 mph, with gusts generally around 25-35 mph.
Wouldn`t be surprised if there`s a few gusts closer to 40 mph in
some of the more favorable terrain, but perhaps not at the RAWS
itself.
An approaching front this afternoon and evening will bring
slightly increased moisture along with a chance for an isolated
shower, but chances for measurable precipitation are quite low.
Overnight humidity recovery is forecast to be close to 50% again.
Friday should be slightly cooler with slightly improved RH, along
with isolated showers/storms in the afternoon again.
.TODAY...
Sky/weather.........Mostly sunny (10-20 percent) until 1400, then
partly cloudy (25-35 percent).
CWR.................4 percent.
Chance of pcpn......10 percent.
LAL.................1.
Max temperature.....Around 66.
Min humidity........20 percent.
Wind (20 ft)........Southwest winds 9 to 15 mph until 1300, then
15-20 mph. Gusts up to 35 mph in the afternoon.
Gusty and erratic winds expected near
thunderstorms after 1500.
Mixing height.......Below 1000 FT AGL until 0700, then 2200 ft AGL
until 0900, then 6700 ft AGL until 1200, then
10200 ft AGL until 1600, then 7400 ft AGL.
Transport winds.....West 20 to 26 mph until 0900, then 31 to 37
mph.
Smoke dispersal.....Poor until 0800, then fair until 0900, then
very good until 1000, then excellent.
Haines Index........5 or moderate potential for large plume
dominated fire growth.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........8 6 5 8 11 15 23 24 28 28 32 34
Weather cov..... SCH SCH SCH
Weather type.... RW RW RW
Tstm cov........ SCH SCH SCH
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).0 0 0 0 0 0 10 10 10 10 10 10
LAL.............1 1 1 1 1 1 1 1 1 2 2 2
Temp............39 42 48 54 56 60 62 63 64 64 61 59
RH..............39 36 32 27 23 21 20 20 21 22 26 28
20 FT wind dir..SW SW SW SW W W W W W W W W
20 FT wind spd..9 8 8 9 10 12 14 15 16 17 18 18
20 FT wind gust.15 13 13 15 16 18 22 24 27 29 33 32
Mix hgt (kft)...0.9 1.1 2.2 4.6 6.4 7.4 9.0 10 10 9.3 7.4 6.4
Transp wind dir.W W W W W W W W W W W W
Transp wind spd.20 21 26 33 33 33 36 36 33 31 37 33
Haines index....5 5 5 5 5 5 5 5 5 5 5 5
Vrate kt-ft/1K..15 19 51 132 185 215 280 309 298 251 237 185
SmokeDispersion.P P F VG E E E E E E E E
.TONIGHT...
Sky/weather.........Mostly clear (20-30 percent).
CWR.................4 percent.
Chance of pcpn......10 percent.
LAL.................1.
Min temperature.....Around 33.
Max humidity........53 percent.
Wind (20 ft)........West winds 10 to 20 mph. Gusts up to 30 mph in
the evening. Gusty and erratic winds expected
near thunderstorms until 2400.
Mixing height.......3800 ft AGL until 2000. Below 1000 FT AGL after
0100.
Transport winds.....West 23 to 30 mph until 2400, then 16 to 21
mph.
Smoke dispersal.....Very good until 1900, then good until 2000,
then fair until 2100, then poor.
Haines Index........3 or very low potential for large plume
dominated fire growth.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........26 26 27 30 26 23 19 18 16 17 17 17
Weather cov.....SCH SCH SCH
Weather type....RW RW RS
Tstm cov........SCH SCH SCH
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).10 10 10 10 10 10 0 0 0 0 0 0
LAL.............2 2 2 1 1 1 1 1 1 1 1 1
Temp............56 50 46 43 40 40 38 37 35 35 35 33
RH..............32 37 42 45 46 44 44 44 46 47 48 50
20 FT wind dir..W W W W W W W W W W W W
20 FT wind spd..16 17 17 17 16 12 10 10 12 12 10 10
20 FT wind gust.25 28 28 28 25 18 16 16 18 18 15 15
Mix hgt (kft)...4.6 3.8 1.8 1.0 1.1 1.0 1.0 0.9 0.7 0.7 0.7 0.7
Transp wind dir.W W W W W W W W W W W W
Transp wind spd.30 30 28 28 28 23 20 18 16 16 16 16
Haines index....3 3 3 3 3 3 3 3 3 3 3 3
Vrate kt-ft/1K..121 99 44 24 26 20 17 14 10 10 10 10
SmokeDispersion.VG G F P P P P P P P P P
.FRIDAY...
Sky/weather.........Mostly sunny (15-25 percent) until 1100, then
partly cloudy (35-45 percent) until 1600, then
mostly cloudy (60-70 percent). Slight chance of
rain showers and thunderstorms after 1200.
CWR.................4 percent.
Chance of pcpn......20 percent.
LAL.................1 until 1200, then 2 until 1500, then 3.
Max temperature.....Around 60.
Min humidity........27 percent.
Wind (20 ft)........West 5-10 mph until 0900, then southwest 7-12
mph with gusts to 20 mph. Gusty and erratic
winds expected near thunderstorms after 1200.
Mixing height.......Below 1000 FT AGL until 0800. 7200 ft AGL after
1100.
Transport winds.....West 10 to 18 mph until 1400, then southwest 15
to 21 mph.
Smoke dispersal.....Poor until 1000, then fair until 1100, then
good until 1200, then very good until 1700,
then good.
Haines Index........4 or low potential for large plume dominated
fire growth.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........21 14 18 15 23 30 38 41 45 48 58 69
Weather cov..... SCH SCH SCH SCH SCH SCH
Weather type.... RW RW RW RW RW RW
Tstm cov........ SCH SCH SCH SCH SCH SCH
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).0 0 0 0 0 0 20 20 20 20 20 20
LAL.............1 1 1 1 1 1 2 2 2 3 3 3
Temp............33 36 40 46 50 52 53 55 57 58 58 57
RH..............53 50 42 36 32 29 29 29 27 27 28 32
20 FT wind dir..W W W SW SW S S S SW W SW S
20 FT wind spd..8 7 6 5 7 8 10 11 10 11 9 8
20 FT wind gust.16 15 12 12 16 18 20 20 20 20 18 17
Mix hgt (kft)...0.7 0.8 2.3 3.5 4.7 5.8 6.9 7.3 7.7 8.1 6.9 5.6
Transp wind dir.W W W W W W W W W W SW SW
Transp wind spd.15 12 12 10 13 15 17 18 20 21 17 15
Haines index....4 4 4 4 4 4 4 4 4 4 4 4
Vrate kt-ft/1K..9 8 22 31 52 76 103 117 131 146 106 72
SmokeDispersion.P P P P F G VG VG VG VG VG G
$$
Forecaster...Hiris
Requested by...Luke Finn
Type of request...PRESCRIBED
.TAG 2414199.6/BOU
.DELDT 05/23/24
.FormatterVersion 2.0.0
.EMAIL luke.finn@usda.gov