519
FNUS71 KBOX 170530
FWSBOX
SPOT FORECAST FOR LEYDEN WMA RX FIRE 20250417...MASSWILDLIFE
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
130 AM EDT THU APR 17 2025
FORECAST IS BASED ON IGNITION TIME OF 0500 EDT ON APRIL 17.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL
WEATHER SERVICE.
DISCUSSION
DRY AND BREEZY TODAY NW WINDS 5-10 MPH WITH GUSTS 20-25 MPH.
RELATIVE HUMIDITY VALUES DROP INTO THE 24-30 PERCENT RANGE IN THE
AFTERNOON. GRADUALLY IMPROVING SMOKE DISPERSAL THROUGH THE MORNING
AS MIXING INCREASES WITH VERY GOOD TO EXCELLENT DISPERSAL BY THE
AFTERNOON. LIGHT NW TO W WINDS THURSDAY NIGHT WITH RELATIVE
HUMIDITIES RECOVERING INTO THE 70 PERCENT RANGE.
MAINLY DRY FRIDAY WITH SOUTH WINDS 5-10 MPH WITH GUSTS UP TO 20
MPH IN THE AFTERNOON. RELATIVE HUMIDITY VALUES DROP TO 30-35
PERCENT. SHOWERS DEVELOP BY FRIDAY EVENING WITH LOW PROBABILITY
FOR WETTING RAIN.
REST OF TONIGHT
SKY/WEATHER.........MOSTLY CLEAR.
CWR.................0 PERCENT.
MIN TEMPERATURE.....AROUND 32.
MAX HUMIDITY........75 PERCENT.
DEWPOINT............26.
MIN APPARENT TEMP...27.
SURFACE WINDS (MPH).NORTHWEST WINDS AROUND 7 MPH.
WIND (20 FT)........NORTHWEST WINDS AROUND 7 MPH.
MIXING HEIGHT.......500 FT AGL.
TRANSPORT WINDS.....NORTHWEST AROUND 10 MPH.
SMOKE DISPERSAL.....POOR (4700 KNOT-FT).
LVORI...............4.
ADI.................5.
CEILING (KFT).......25.
TIME (EDT) 5AM
SKY (%).........18
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0
TEMP............33
DEWPOINT........26
RH..............75
HEAT INDEX (F)..27
20 FT WIND DIR..NW
20 FT WIND SPD..7
20 FT WIND GUST.15
SURFACE WND DIR.NW
SURFACE WND SPD.7
SURFACE WND GST.15
MIX HGT (KFT)...0.5
TRANSP WIND DIR.NW
TRANSP WIND SPD.10
LVORI...........4
ADI.............5
VRATE KT-FT/1K..5
VENTRATE CAT....PR
CEILING (KFT)...25
TODAY
SKY/WEATHER.........SUNNY.
CWR.................0 PERCENT.
MAX TEMPERATURE.....AROUND 52.
MIN HUMIDITY........26 PERCENT.
DEWPOINT............24 DECREASING TO 19 IN THE AFTERNOON.
MIN APPARENT TEMP...26.
SURFACE WINDS (MPH).NORTHWEST WINDS 8 TO 9 MPH.
WIND (20 FT)........NORTHWEST WINDS 8 TO 9 MPH.
MIXING HEIGHT.......5800 FT AGL.
TRANSPORT WINDS.....NORTHWEST 13 TO 22 MPH INCREASING TO 23 TO 26
MPH IN THE LATE MORNING AND AFTERNOON.
SMOKE DISPERSAL.....POOR (10500 KNOT-FT) EARLY IN THE MORNING
INCREASING TO EXCELLENT (108900 KNOT-FT) IN THE
AFTERNOON INCREASING TO EXCELLENT (124000
KNOT-FT) LATE IN THE AFTERNOON.
LVORI...............3.
ADI.................16 INCREASING TO 105.
CEILING (KFT).......25.
TIME (EDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........9 6 6 5 3 3 2 2 2 2 2 2
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
TEMP............33 33 34 36 40 42 44 46 50 51 52 52
DEWPOINT........26 26 25 25 24 23 22 21 20 19 19 18
RH..............75 75 69 64 52 46 41 37 30 28 27 26
HEAT INDEX (F)..26 26 27 29 34 36 39 41 46 51 52 52
20 FT WIND DIR..NW W NW NW NW NW NW NW NW NW NW NW
20 FT WIND SPD..8 8 9 9 9 9 9 9 9 9 9 9
20 FT WIND GUST.16 16 17 18 18 18 18 18 18 18 18 18
SURFACE WND DIR.NW W NW NW NW NW NW NW NW NW NW NW
SURFACE WND SPD.8 8 9 9 9 9 9 9 9 9 9 9
SURFACE WND GST.16 16 17 18 18 18 18 18 18 18 18 18
MIX HGT (KFT)...1.0 1.5 2.1 2.7 3.2 3.9 4.5 5.2 5.8 5.8 5.8 5.6
TRANSP WIND DIR.NW NW NW NW NW NW NW NW NW NW NW NW
TRANSP WIND SPD.13 17 22 23 23 23 24 24 25 25 26 25
LVORI...........4 3 1 1 1 1 1 1 1 1 1 1
ADI.............16 33 55 69 77 84 95 102 105 105 105 105
VRATE KT-FT/1K..11 22 39 54 65 77 95 109 128 128 132 124
VENTRATE CAT....PR PR PR FR GD GD GD VGD VGD VGD VGD VGD
CEILING (KFT)...25 25 25 25 25 25 25 25 25 25 25 25
TONIGHT
SKY/WEATHER.........MOSTLY CLEAR.
CWR.................0 PERCENT.
MIN TEMPERATURE.....AROUND 27.
MAX HUMIDITY........78 PERCENT.
DEWPOINT............20.
MIN APPARENT TEMP...28.
SURFACE WINDS (MPH).NORTHWEST WINDS 5 TO 8 MPH IN THE EVENING
BECOMING LIGHT.
WIND (20 FT)........NORTHWEST WINDS AROUND 8 MPH DECREASING TO 5 TO
7 MPH IN THE EVENING, THEN BECOMING LIGHT
AROUND MIDNIGHT.
MIXING HEIGHT.......300 FT AGL.
TRANSPORT WINDS.....NORTHWEST 14 TO 23 MPH SHIFTING TO THE WEST 6
TO 12 MPH UNTIL JUST AFTER MIDNIGHT, THEN
SHIFTING TO THE SOUTHWEST 5 TO 6 MPH EARLY IN
THE MORNING.
SMOKE DISPERSAL.....EXCELLENT (98400 KNOT-FT) EARLY IN THE EVENING
DECREASING TO POOR (1100 KNOT-FT) LATE IN THE
NIGHT.
LVORI...............3.
ADI.................105 DECREASING TO 2 TO 6.
CEILING (KFT).......25 DECREASING TO 20, THEN INCREASING TO 25
AFTER MIDNIGHT.
TIME (EDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM
SKY (%).........7 4 11 5 4 4
WEATHER COV.....
WEATHER TYPE....NONE NONE NONE NONE NONE NONE
TSTM COV........
CWR.............0 0 0 0 0 0
TEMP............51 44 39 34 31 29
DEWPOINT........19 21 22 22 22 22
RH..............28 39 50 61 69 75
HEAT INDEX (F)..51 41 36 34 31 29
20 FT WIND......NW 8 NW 6 NW 5 W 2 W 2 W 2
20 FT WIND GUST.16 13 9 6 5 3
SURFACE WIND....NW 8 NW 6 NW 5 W 2 W 2 W 2
SURFACE WND GST.16 13 9 6 5 3
MIX HGT (FT)....4900 500 400 300 300 300
TRANSPORT WIND..NW 23 NW 12 NW 8 W 6 W 6 SW 6
LVORI...........1 2 2 3 3 4
ADI.............105 5 4 3 3 3
VRATE KT-FT/1K..98 5 3 2 1 1
VENTRATE CAT....GOOD POOR POOR POOR POOR POOR
CEILING (KFT)...25 25 25 25 25 25
FRIDAY
SKY/WEATHER.........MOSTLY SUNNY THEN BECOMING MOSTLY CLOUDY.
SLIGHT CHANCE OF RAIN SHOWERS LATE IN THE
AFTERNOON.
CWR.................6 PERCENT.
MAX TEMPERATURE.....AROUND 61.
MIN HUMIDITY........34 PERCENT.
DEWPOINT............24 INCREASING TO 34.
MIN APPARENT TEMP...28.
SURFACE WINDS (MPH).LIGHT WINDS BECOMING SOUTH 5 TO 9 MPH IN THE
LATE MORNING AND AFTERNOON.
WIND (20 FT)........SOUTH WINDS 5 TO 9 MPH EARLY IN THE MORNING
BECOMING LIGHT, THEN BECOMING SOUTH 5 TO 9 MPH
IN THE LATE MORNING AND AFTERNOON.
MIXING HEIGHT.......4400 FT AGL.
TRANSPORT WINDS.....SOUTHWEST 5 TO 13 MPH INCREASING TO 16 TO 24
MPH EARLY.
SMOKE DISPERSAL.....POOR (1600 KNOT-FT) EARLY IN THE MORNING
INCREASING TO EXCELLENT (88000 KNOT-FT) IN THE
AFTERNOON.
LVORI...............3.
ADI.................5 TO 14 INCREASING TO 35, THEN INCREASING TO 60
EARLY INCREASING TO 77 TO 78 EARLY IN THE
AFTERNOON INCREASING TO 85 TO 90 DECREASING TO
78 TO 80 LATE IN THE AFTERNOON.
CEILING (KFT).......25 DECREASING TO 10.
TIME (EDT) 6 AM 10 AM 2 PM
SKY (%).........11 37 67
WEATHER COV.....
WEATHER TYPE....NONE NONE NONE
TSTM COV........
CWR.............0 0 10
TEMP............28 45 59
DEWPOINT........22 26 31
RH..............78 47 34
HEAT INDEX (F)..28 43 59
20 FT WIND......SW 2G3 S 5G9 S 8G16
SURFACE WIND....SW 2G3 S 5G9 S 8G16
MIX HGT (FT)....300 2200 4400
TRANSPORT WIND..SW 6 SW 13 SW 23
LVORI...........4 1 1
ADI.............6 35 90
VRATE KT-FT/1K..2 24 88
VENTRATE CAT....POOR POOR GOOD
CEILING (KFT)...25 25 11
FORECASTER...MENSCH
REQUESTED BY...BEN MAZZEI
TYPE OF REQUEST...PRESCRIBED
.TAG 2510789.0/BOX
.DELDT 04/17/25
.FORMATTERVERSION 2.0.0
.EMAIL BEN.MAZZEI@MASS.GOV
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