605
FNUS73 KDMX 081251
FWSDMX

Spot Forecast for Prairie Valley Preserve...Story County Conservation
National Weather Service Des Moines IA
751 AM CDT Fri May 8 2026

Forecast is based on ignition time of 1100 CDT on May 08.
If conditions become unrepresentative...contact the National Weather
Service.

An initial observation at ignition and a mid burn observation are required.

Please relay them to the National Weather Service for each prescribed burn.

.DISCUSSION...

Winds will begin light and variable early this morning, but will
increase out of the southwest around ignition time. The boundary
layer fully mixes out by noon today, leading to sustained westerly winds
around 10 to 12 mph with gusts up to 20 mph likely. A few
stronger gusts near 25 mph may also be possible at times this afternoon.
The deep mixed layer will allow for excellent smoke dispersal and
dry conditions. Relative humidities drop into the 20 to 25
percent range with air temperatures reaching the mid 70s today.

.REST OF TODAY...

Sky/weather.........Mostly sunny (25-35 percent).
Max temperature.....Around 74.
Min humidity........24 percent.
Wind (20 ft)........Southwest winds 5 to 6 mph shifting to the west
                    7 to 10 mph in the afternoon.
Mixing height.......9600 ft AGL.
Transport winds.....West 9 to 18 mph.
Smoke dispersal.....Poor (28000 knot-ft) early increasing to
                    excellent (153400 knot-ft) by late in
                    the afternoon.
GFDI................0.

TIME (CDT)      11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........31  30  28  27  27  26  33
Weather cov.....
Weather type....
Tstm cov........
Temp............63  66  69  70  72  72  73
RH..............41  33  27  26  24  24  24
20 FT wind dir..SW  W   W   W   W   W   W
20 FT wind spd..5   6   7   7   8   9   10
20 FT wind gust.6   8   10  13  15  16  16
Mix hgt (kft)...3.5 5.7 6.8 7.8 8.8 9.3 9.6
Transp wind dir.W   NW  W   W   W   W   W
Transp wind spd.9   10  13  13  16  17  18
GFDI............0   0   0   0   0   0   0
Smoke Dispersal.28  51  75  86  123 140 153
Smoke Cat.......PR  FR  GD  GD  VGD VGD EXL

.TONIGHT...

Sky/weather.........Mostly clear (15-25 percent).
Min temperature.....Around 46.
Max humidity........65 percent.
Wind (20 ft)........West winds 5 to 10 mph.
Mixing height.......400 ft AGL.
Transport winds.....West 9 to 18 mph decreasing to around 8 mph
                    early in the morning.
Smoke dispersal.....Very good (136600 knot-ft) decreasing to poor
                    (2500 knot-ft).
GFDI................0.

TIME (CDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........29  30  32  36  18  24  14  4   3   2   10  4
Weather cov.....
Weather type....
Tstm cov........
Temp............74  72  68  62  59  57  55  53  51  49  48  48
RH..............23  27  33  43  47  51  55  57  61  63  65  65
20 FT wind dir..W   SW  SW  SW  SW  W   W   W   W   W   W   W
20 FT wind spd..10  7   6   7   6   6   6   6   6   5   6   6
20 FT wind gust.16  12  10  9   8   9   8   9   9   8   8   8
Mix hgt (kft)...8.5 2.1 0.5 0.4 0.4 0.5 0.4 0.4 0.4 0.4 0.4 0.4
Transp wind dir.W   W   W   SW  SW  W   NW  NW  NW  NW  W   W
Transp wind spd.18  12  12  13  14  14  13  13  12  9   9   8
GFDI............0   0   0   0   0   0   0   0   0   0   0   0
Smoke Dispersal.137 21  5   5   5   6   5   4   4   3   3   3
Smoke Cat.......VGD PR  PR  PR  PR  PR  PR  PR  PR  PR  PR  PR

.SATURDAY...

Sky/weather.........Sunny (15-25 percent) then becoming partly
                    sunny (50-60 percent).
Max temperature.....Around 75.
Min humidity........29 percent.
Wind (20 ft)........West winds 6 to 10 mph shifting to the north
                    around 14 mph late in the afternoon.
Mixing height.......7100 ft AGL.
Transport winds.....West 9 to 17 mph shifting to the northwest 18
                    to 22 mph in the late morning and afternoon.
Smoke dispersal.....Poor (3000 knot-ft) increasing to very good
                    (120000 knot-ft) late in the afternoon.
GFDI................0.

TIME (CDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........11  3   6   35  41  57  60  63  47  64  50  64
Weather cov.....
Weather type....
Tstm cov........
Temp............47  48  52  57  64  68  71  73  73  74  73  73
RH..............68  68  61  55  45  39  35  33  33  30  30  29
20 FT wind dir..W   W   W   W   W   NW  NW  NW  NW  NW  N   N
20 FT wind spd..6   6   7   8   10  13  14  15  15  15  14  14
20 FT wind gust.8   8   9   12  15  18  21  22  22  22  21  21
Mix hgt (kft)...0.4 0.4 0.7 1.6 2.6 4.2 4.6 5.0 6.7 7.1 5.7 6.6
Transp wind dir.W   SW  W   W   W   W   W   NW  NW  NW  NW  NW
Transp wind spd.9   10  12  17  20  22  20  18  20  20  18  18
GFDI............0   0   0   0   0   0   0   0   0   0   0   0
Smoke Dispersal.3   4   7   24  44  79  78  80  113 120 91  106
Smoke Cat.......PR  PR  PR  PR  FR  GD  GD  GD  VGD VGD GD  VGD

$$
Forecaster...Dodson
Requested by...Brandon Clough
Type of request...PRESCRIBED
.TAG 2613133.0/DMX
.DELDT 05/08/26
.FormatterVersion 2.0.0
.EMAIL bclough@storycountyiowa.gov