121
FNUS73 KOAX 131320
FWSOAX

Spot Forecast for Zimmerman...Iowa DNR Mo River
National Weather Service Omaha/Valley NE
820 AM CDT Tue May 13 2025

Forecast is based on ignition time of 0900 CDT on May 13.
If conditions become unrepresentative, contact the National Weather
Service.

.DISCUSSION...

Winds are light out of the southeast this morning. A morning
inversion is in place keeping mixing heights down around 500 ft.
This will burn off around 10-11 AM this morning with mixing
heights rapidly increasing to 6000-6500 ft by noon. Winds around
this time will also increase out of the south-southeast to around
10 to 15 mph with gusts to 20 mph. Could see a few gusts to 25 mph
through the afternoon. Humidity will drop to around 27 percent
during the afternoon as well. With high mixing heights and
transport winds around 15 mph out of the south, smoke dispersal
should be excellent once the inversion breaks by 11 AM, through
the rest of the afternoon.

Strongest Possible Wind Speeds on Day of Burn: 28 mph

Lowest Possible Relative Humidity on Day of Burn: 23 percent

.REST OF TODAY...

Sky/weather.........Sunny (0-5 percent).
Max temperature.....Around 87.
Min humidity........27 percent.
Eye level winds.....South winds up to 8 mph. Gusts up to 23 mph in
                    the afternoon.
Surface winds (mph).South winds 8 to 13 mph. Gusts up to 23 mph in
                    the afternoon.
Wind (20 ft)........South winds 7 to 12 mph. Gusts up to 23 mph in
                    the afternoon.
Mixing height.......7900 ft AGL.
Transport winds.....South 14 to 16 mph.
Smoke dispersal.....Poor (12500 knot-ft) early in the morning
                    increasing to excellent (111000 knot-ft) in the
                    afternoon.
GFDI................0.

TIME (CDT)      9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........0   1   0   1   2   1   1   2   2
Weather cov.....
Weather type....
Tstm cov........
Temp............68  75  79  81  83  85  86  87  87
RH..............57  46  38  34  31  27  28  27  27
20 FT wind dir..S   S   S   S   S   S   S   S   S
20 FT wind spd..6   8   8   9   9   9   10  10  10
20 FT wind gust.7   13  14  16  18  18  18  18  18
Eye lvl wnd dir.S   S   S   S   S   S   S   S   S
Eye lvl wnd spd.4   6   6   7   7   7   8   8   8
Eye lvl wnd gst.5   10  11  12  13  14  14  14  14
Surface wnd dir.S   S   S   S   S   S   S   S   S
Surface wnd spd.8   10  10  11  11  11  13  13  13
Surface wnd gst.9   16  18  20  22  23  23  23  23
Mix hgt (kft)...1.1 2.0 5.1 6.2 6.7 7.1 7.5 7.9 7.7
Transp wind dir.S   S   S   S   S   S   S   S   S
Transp wind spd.14  14  16  16  16  16  16  16  16
GFDI............0   0   0   0   0   0   0   0   0
SDspl kt-ft/100013  24  46  72  93  106 111 110 107

.TONIGHT...

Sky/weather.........Mostly clear (5-15 percent).
Min temperature.....Around 60.
Max humidity........83 percent.
Eye level winds.....Southeast winds 5 to 7 mph. Gusts up to 22 mph
                    early in the evening.

TIME (CDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........8   17  11  12  11  12  4   8   7   6   6   6
Weather cov.....
Weather type....
Tstm cov........
Temp............86  85  82  76  73  71  70  68  67  65  63  63
RH..............29  30  33  42  48  55  57  63  68  73  80  78
Eye lvl wnd dir.S   S   SE  SE  SE  SE  SE  SE  SE  SE  SE  SE
Eye lvl wnd spd.7   6   6   6   6   6   6   6   6   5   5   5
Eye lvl wnd gst.13  11  7           7   7   7       6

$$
Forecaster...McCoy
Requested by...Doug Chafa
Type of request...PRESCRIBED
.TAG 2513863.0/OAX
.DELDT 05/13/25
.FormatterVersion 2.0.0
.EMAIL Doug.Chafa@dnr.iowa.gov