Spot Forecast
Issued by NWS La Crosse, WI

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FNUS73 KARX 211250
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Spot Forecast for Grannis Creek...Iowa DNR
National Weather Service La Crosse WI
750 AM CDT Thu Mar 21 2024

Forecast is based on ignition time of 0800 CDT on March 21.
If conditions become unrepresentative...contact the National Weather
Service.

Please contact our office at (608) 784-8292 if you have questions
or concerns with this forecast.

.DISCUSSION...

Today remains to be the driest day in the forecast period with
low relative humidities around 30 to 35%. Winds remain light 5 to
10 mph however there will be variable conditions due to local
terrain. Smoke disperal will be fair today and poor tonight.

Fire weather conditions improve tonight into Friday as a storm
system moves into the area and brings wetting precipitation. The
active weather pattern is expected to continue into early next
week as another storm looks to move into the region on Sunday.

.REST OF TODAY...

Sky/weather.........Mostly cloudy (80-90 percent).
CWR.................10 percent.
Temperature.........26 at ignition...Max 39.
RH..................40 percent at ignition...Min 32 percent.
Wind (20 ft)........Winds east at 4 mph at ignition...otherwise
                    Light winds becoming east 5 to 6 mph in the
                    late morning and afternoon.
Mixing height.......1400 ft AGL at ignition...otherwise 3600 ft
                    AGL.
Transport winds.....East 6 to 9 mph shifting to the southeast 6 to
                    7 mph late in the afternoon.
Smoke dispersal.....Poor /11400 knot-ft/ at ignition. Max...fair
                    /21800 knot-ft/.
Haines Index........4 or low potential for large plume dominated
                    fire growth at ignition...max 4.

TIME (CDT)      8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........87  82  90  90  92  89  89  88  88  87
Weather cov.....
Weather type....
Tstm cov........
CWR.............10  10  10  10  10  10  10  10  10  10
Temp............26  26  28  31  33  34  35  37  37  38
RH..............40  40  37  32  33  33  33  32  33  35
20 FT wind dir..E   E   E   E   E   E   E   E   E   E
20 FT wind spd..4   5   5   5   5   5   5   6   5   6
20 FT wind gust.6   7   7   6   6   6   6   7   7   8
Mix hgt (kft)...1.4 2.3 3.0 3.3 3.6 3.6 3.4 3.3 3.3 3.3
Transp wind dir.E   E   E   E   E   SE  SE  SE  SE  SE
Transp wind spd.9   8   8   6   7   7   6   7   7   7
Haines index....4   4   4   4   4   3   3   3   3   3
SDspl kt-ft/100011  16  21  16  21  22  17  20  20  20

.TONIGHT...

Sky/weather.........Cloudy (90-100 percent). Chance of snow in the
                    evening, then snow, slight chance of freezing
                    rain and light sleet overnight.
CWR.................10 percent increasing to 20 percent late in the
                    evening, then decreasing to 10 percent late in
                    the evening increasing to 30 percent late in
                    the evening increasing to 40 percent increasing
                    to 60 percent overnight decreasing to 50
                    percent increasing to 70 percent after 3 am
                    increasing to 80 percent increasing to 100
                    percent early in the morning.
Temperature.........Min 28.
RH..................Max 88 percent.
Wind (20 ft)........East winds 7 to 9 mph.
Mixing height.......500 ft AGL.
Transport winds.....East 8 to 17 mph.
Smoke dispersal.....Fair (20300 knot-ft) early in the evening
                    decreasing to poor (4200 knot-ft) late in the
                    night.
Haines Index........2 to 3 or very low potential for large plume
                    dominated fire growth.

TIME (CDT)      6 PM   8 PM   10 PM  MIDNGT 2 AM   4 AM
Sky (%).........89     92     96     97     98     97
Weather cov.....                     CHANCE CHANCE DEFNTE
Weather type....NONE   NONE   NONE   SNOW   SNOW   SNOW
Tstm cov........
CWR.............10     10     10     40     50     80
Temp............39     35     32     32     31     30
RH..............32     45     58     66     75     85
20 ft wind......E 7    E 8    E 9    E 9    E 9    E 9
20 ft wind gust.9      12     14     15     14     15
Mix hgt (ft)....2900   500    500    900    800    1200
Transport wind..E 8    E 10   E 13   SE 14  E 14   E 16
Haines index....3      3      3      3      2      2
SDspl kt-ft/100020     4      6      11     10     17

.FRIDAY...

Sky/weather.........Cloudy (85-95 percent). Snow and slight chance
                    of thunderstorms in the morning, then slight
                    chance of snow in the afternoon.
CWR.................100 percent decreasing to 10 percent.
Temperature.........Max 37.
RH..................Min 75 percent.
Wind (20 ft)........East winds 8 to 9 mph with gusts to around 19
                    mph shifting to the north 11 to 12 mph late in
                    the afternoon. Gusty and erratic winds expected
                    near thunderstorms early in the morning.
Mixing height.......2600 ft AGL.
Transport winds.....East 9 to 17 mph shifting to the north 12 to 21
                    mph early in the afternoon, then increasing to
                    21 to 22 mph late in the afternoon.
Smoke dispersal.....Poor (11000 knot-ft) early in the morning
                    increasing to good (50000 knot-ft) in the
                    afternoon.
Haines Index........2 or very low potential for large plume
                    dominated fire growth.

TIME (CDT)      6 AM   8 AM   10 AM  NOON   2 PM   4 PM
Sky (%).........99     100    98     90     91     85
Weather cov.....DEFNTE DEFNTE LIKELY S CHC
Weather type....SNOW   SNOW   SNOW   SNOW   NONE   NONE
Tstm cov........       S CHC
CWR.............100    100    60     20     10     0
Temp............30     28     31     34     35     37
RH..............92     100    100    89     85     75
20 ft wind......E 9    E 9    E 9    NE 8   N 10   N 12
20 ft wind gust.15     18     12     11     15     19
Mix hgt (ft)....1100   1100   1200   1800   2100   2600
Transport wind..E 16   E 17   E 13   N 12   N 21   N 22
Haines index....2      2      2      2      2      2
SDspl kt-ft/100015     16     13     18     39     50

$$
Forecaster...CZ
Requested by...Trent Stuchel
Type of request...PRESCRIBED
.TAG 2408070.0/ARX
.DELDT 03/21/24
.FormatterVersion 2.0.0
.EMAIL trent.stuchel@dnr.iowa.gov


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