Spot Forecast
Issued by NWS Omaha/Valley, NE
Issued by NWS Omaha/Valley, NE
128
FNUS73 KOAX 081354
FWSOAX
Spot Forecast for St. Marys Island...Iowa DNR
National Weather Service Omaha/Valley NE
854 AM CDT Wed May 8 2024
Forecast is based on ignition time of 1100 CDT on May 08.
If conditions become unrepresentative, contact the National Weather
Service.
.DISCUSSION...
Temperatures today mainly will be in the 70s. West to southwest
winds at 10 to 15 mph with gusts up to 20 mph are expected.
Isolated showers this morning may bring gusty winds as high as 55
mph. There has already been a 55 mph wind gust recorded at Harlan
earlier this morning.
Strongest Possible Wind Speeds on Day of Burn: 20 mph. Gusts up to
50 mph possible under any shower or thunderstorm that develops
today.
Lowest Possible Relative Humidity on Day of Burn: 40%
.REST OF TODAY...
Sky/weather.........Mostly sunny (45-55 percent). Slight chance of
showers and thunderstorms late in the
afternoon.
Temperature.........66 at ignition...Max 75.
RH..................58 percent at ignition...Min 38 percent.
Eye level winds.....Southeast winds up to 6 mph shifting to the
northeast around 4 mph late in the afternoon,
then shifting to the west up to 6 mph late in
the afternoon.
Surface winds (mph).Southeast winds around 10 mph decreasing to 8
to 9 mph early in the afternoon, then shifting
to the northeast around 8 mph late in the
afternoon shifting to the west 8 to 10 mph late
in the afternoon.
Wind (20 ft)........Winds southeast at 8 mph at
ignition...otherwise Southeast winds around 9
mph decreasing to 6 to 8 mph early in the
afternoon, then shifting to the northeast
around 6 mph late in the afternoon shifting to
the west 7 to 9 mph late in the afternoon.
Gusty and erratic winds expected near
thunderstorms late in the afternoon.
Mixing height.......1900 ft AGL at ignition...otherwise 7500 ft
AGL.
Transport winds.....Southeast 12 to 17 mph shifting to the south
around 7 mph early in the afternoon, then
shifting to the west 8 to 10 mph late in the
afternoon.
Smoke dispersal.....Fair /24200 knot-ft/ at ignition.
Max...excellent /60000 knot-ft/.
GFDI................0.
Haines Index........6 or high potential for large plume dominated
fire growth at ignition...max 6.
TIME (CDT) 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........29 53 34 59 52 50 67
Weather cov..... SCH SCH SCH
Weather type.... RW RW RW
Tstm cov........ SCH SCH SCH
Temp............66 70 72 74 74 75 73
RH..............58 51 44 43 41 38 41
20 FT wind dir..SE SE SE SE NE W W
20 FT wind spd..8 7 6 6 6 6 8
20 FT wind gust.13 12 10 10 10 10 13
Eye lvl wnd dir.SE SE SE SE NE W W
Eye lvl wnd spd.6 5 4 4 4 4 6
Eye lvl wnd gst.10 9 8 7 7 8 10
Surface wnd dir.SE SE SE SE NE W W
Surface wnd spd.10 9 8 8 8 8 10
Surface wnd gst.16 15 13 12 12 13 16
Mix hgt (kft)...1.9 3.9 5.5 6.8 7.5 7.5 6.1
Transp wind dir.SE SE SE S W NW W
Transp wind spd.17 16 12 7 8 8 10
GFDI............0 0 0 0 0 0 0
Haines index....6 6 5 5 5 5 5
SDspl kt-ft/100024 42 55 60 59 53 42
.TONIGHT...
Sky/weather.........Mostly cloudy (50-60 percent) then becoming
mostly clear (15-25 percent). Chance of showers
and thunderstorms early in the evening, then
slight chance of showers and thunderstorms
early in the evening.
Temperature.........Min 49.
RH..................Max 96 percent.
Eye level winds.....Northwest winds up to 6 mph.
Surface winds (mph).Northwest winds 6 to 10 mph.
Wind (20 ft)........Northwest winds 5 to 9 mph. Gusty and erratic
winds expected near thunderstorms early in the
evening.
Mixing height.......400 ft AGL.
Transport winds.....Northwest 10 to 12 mph shifting to the north
overnight.
Smoke dispersal.....Fair (28800 knot-ft) early in the evening
decreasing to poor (3500 knot-ft) late in the
night.
GFDI................0.
Haines Index........5 or moderate potential for large plume
dominated fire growth.
TIME (CDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM
Sky (%).........58 35 21 16 8 22
Weather cov.....CHANCE S CHC
Weather type....RNSHWR RNSHWR NONE NONE NONE NONE
Tstm cov........CHANCE S CHC
Temp............73 67 60 56 53 51
RH..............40 49 60 72 83 89
20 ft wind......W 8 NW 7 NW 6 N 6 N 6 NW 6
20 ft wind gust.13
Eye level wind..W 6 NW 5 NW 4 N 4 N 4 NW 4
Eye lvl wnd gst.10 5
Surface wind....W 10 NW 9 NW 8 N 8 N 8 NW 8
Surface wnd gst.16
Mix hgt (ft)....4300 500 500 500 400 500
Transport wind..W 10 NW 10 NW 12 N 12 N 12 N 10
GFDI............0 0 0 0 0 0
Haines index....5 5 5 5 5 5
SDspl kt-ft/100029 10 5 4 4 4
.THURSDAY...
Sky/weather.........Mostly sunny (45-55 percent). Chance of rain
showers. Slight chance of thunderstorms in the
afternoon.
Temperature.........Max 66.
RH..................Min 56 percent.
Eye level winds.....North winds up to 9 mph.
Surface winds (mph).North winds 8 to 15 mph.
Wind (20 ft)........North winds 6 to 13 mph. Gusty and erratic
winds expected near thunderstorms in the
afternoon.
Mixing height.......3700 ft AGL.
Transport winds.....North 12 to 17 mph.
Smoke dispersal.....Poor (4100 knot-ft) early in the morning
increasing to good (57300 knot-ft) in the
afternoon.
GFDI................0.
Haines Index........3 to 5 or very low to moderate potential for
large plume dominated fire growth.
TIME (CDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM
Sky (%).........37 42 49 43 50 57
Weather cov..... CHANCE CHANCE CHANCE CHANCE CHANCE
Weather type....NONE RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR
Tstm cov........ S CHC S CHC
Temp............49 51 58 62 63 64
RH..............96 96 80 70 67 63
20 ft wind......NW 6 NW 7 N 9 N 10 N 12 N 12
20 ft wind gust. 8 12 14 16 18
Eye level wind..NW 4 NW 5 N 7 N 8 N 9 N 9
Eye lvl wnd gst. 6 9 10 12 13
Surface wind....NW 8 NW 9 N 11 N 13 N 15 N 15
Surface wnd gst. 10 15 17 20 22
Mix hgt (ft)....500 1200 2200 3000 3500 3700
Transport wind..NW 12 N 16 N 16 N 16 N 16 N 17
GFDI............0 0 0 0 0 0
Haines index....5 3 3 3 3 3
SDspl kt-ft/10004 14 31 46 56 55
.FORECAST DAYS 3 THROUGH 5...
.FRIDAY...
Partly cloudy. Chance of showers and slight chance of
thunderstorms. Lows in the upper 40s. Highs in the mid 70s.
Northwest winds around 8 mph.
.SATURDAY...
Mostly clear. Lows in the upper 40s. Highs in the mid 70s.
Northwest winds around 12 mph.
.SUNDAY...
Partly cloudy. Slight chance of showers and thunderstorms. Lows
in the lower 50s. Highs in the lower 80s. Southwest winds around
8 mph.
$$
Forecaster...Darrah
Requested by...Matt Dollison
Type of request...PRESCRIBED
.TAG 2413479.0/OAX
.DELDT 05/08/24
.FormatterVersion 2.0.0
.EMAIL matt.dollison@dnr.iowa.gov