871
FNUS73 KLSX 111036 CCA
FWSLSX
SPOT FORECAST FOR RIVERLANDS WAY BURN...U.S. ARMY CORPS OF ENGINEERS
NATIONAL WEATHER SERVICE SAINT LOUIS MO
428 AM CST WED DEC 11 2024
FORECAST IS BASED ON IGNITION TIME OF 1100 CST ON DECEMBER 11.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE
NATIONAL WEATHER SERVICE.
DISCUSSION
MIXING WILL BE EFFICIENT TODAY, BY 10 AM THE MIXING HEIGHT WILL BE
AROUND 2,000 FEET. BUT BY PEAK MIXING IN THE MID AFTERNOON THE
HEIGHT IS EXPECTED TO REACH BETWEEN 4,000 AND 5,000 FEET. WE COULD
MIX HIGHER THAN THIS, BUT CONFIDENCE IN MIXING HIGHER THAN 5,000 FT
IS LOW. THIS DEEP MIXING WILL TRANSPORT GUSTS IN THE UPPER 20S (MPH)
TO THE SURFACE THROUGH THE DAY. ALL OF THIS WILL RESULT IN EXCELLENT
SMOKE DISPERSION. SMOKE PLUMES WILL BE ABLE TO RISE RAPIDLY AND
DISPERSE AT THE TOP OF THE MIXED LAYER.
TEMPERATURES WILL BE COLD, PEAKING IN THE MID 30S AND MINIMUM RH
VALUES WILL ONLY DROP INTO THE UPPER 40S. ADDITIONALLY, THERE IS A
20% CHANCE FOR LIGHT SNOW SHOWERS TODAY. THE BEST TIME FOR THESE
SHOWERS WILL BE THIS MORNING BEFORE NOON, BUT UNCERTAINTY REMAINS
IN EXACTLY WHERE AND WHEN THESE SHOWERS DEVELOP. UNDERNEATH THEM
A REDUCTION IN VISIBILITY AND UP TO 0.4" OF SNOW ACCUMULATION ON
GRASSY AND ELEVATED SURFACES IS EXPECTED. OUTSIDE OF THESE SHOWERS
NON-IMPACTFUL FLURRIES ARE POSSIBLE ON AND OFF THROUGHOUT THE DAY.
REST OF TODAY
SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT) THEN BECOMING
SUNNY (20-30 PERCENT). SLIGHT CHANCE OF SNOW
SHOWERS LATE IN THE MORNING.
CHANCE OF PCPN......20 PERCENT.
LAL.................NO TSTMS.
TEMPERATURE.........35 AT IGNITION...MAX 37.
RH..................61 PERCENT AT IGNITION...MIN 48 PERCENT.
WIND (20 FT)........WINDS WEST AT 15 MPH AT IGNITION...OTHERWISE
WEST WINDS 13 TO 16 MPH WITH GUSTS TO AROUND 24
MPH.
EYE LEVEL WINDS.....6 MPH, GUSTING UP TO 10 MPH. USING AN ADJUSTMENT
FACTOR OF 0.4.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
DOMINATED FIRE GROWTH AT IGNITION...MAX 5.
MIXING HEIGHT.......4000 FT AGL AT IGNITION...OTHERWISE MAX 5300 FT
AGL.
TRANSPORT WINDS.....WEST 20 TO 29 MPH.
SMOKE DISPERSAL.....GOOD /13980 M/S-M/ AT IGNITION. MAX...EXCELLENT
/20830 M/S-M/ DECREASING TO POOR (3440 M/S-M)
LATE IN THE AFTERNOON.
TIME (CST) 11 AM 1 PM 3 PM 5 PM 7 PM 9 PM
SKY (%).........83 83 57 10 3 1
WEATHER COV.....S CHC S CHC
WEATHER TYPE....SNSHWR SNSHWR NONE NONE NONE NONE
TSTM COV........
CWR.............20 20 10 10 0 0
LAL.............1 1 1 1 1 1
TEMP............35 36 35 31 26 24
RH..............61 59 54 51 52 54
20 FT WIND......W 15 W 16 W 16 W 13 W 10 W 8
20 FT WIND GUST.21 24 24 19 15 13
EYE LEVEL WIND..W 7 W 7 W 7 W 6 W 5 W 4
EYE LVL WND GST.10 11 11 9 7 6
MIX HGT (KFT)...4.0 4.8 4.9 1.3 0.7 0.7
TRANSPORT WIND..W 25 W 28 NW 29 NW 20 NW 15 NW 15
HAINES INDEX....3 3 4 5 5 5
VRATE KT-FT/1K..89 116 123 22 9 10
VENTRATE CAT....GOOD VYGD VYGD POOR POOR POOR
TONIGHT
SKY/WEATHER.........MOSTLY CLEAR (20-30 PERCENT) THEN BECOMING
MOSTLY CLOUDY (55-65 PERCENT).
CHANCE OF PCPN......10 PERCENT.
LAL.................NO TSTMS.
TEMPERATURE.........MIN 18.
RH..................MAX 64 PERCENT.
WIND (20 FT)........WEST WINDS 5 TO 12 MPH IN THE EVENING BECOMING
LIGHT.
EYE LEVEL WINDS.....2 TO 5 USING AN ADJUSTMENT FACTOR OF 0.4.
HAINES INDEX........2 TO 5 OR VERY LOW TO MODERATE POTENTIAL FOR
LARGE PLUME DOMINATED FIRE GROWTH.
MIXING HEIGHT.......MIN 700 FT AGL.
TRANSPORT WINDS.....NORTHWEST 8 TO 17 MPH DECREASING TO AROUND 5
MPH EARLY IN THE MORNING.
SMOKE DISPERSAL.....POOR (720 M/S-M).
FORECASTER...DELIA
REQUESTED BY...BRIAN STOFF
TYPE OF REQUEST...PRESCRIBED
.TAG 2428269.0/LSX
.DELDT 12/11/24
.FORMATTERVERSION 2.0.0
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