Spot Forecast
Issued by NWS Boston, MA
Issued by NWS Boston, MA
544
FNUS71 KBOX 120819
FWSBOX
Spot Forecast for JBCC GLU grassland Rx Fire 20260512...MassWildlife
National Weather Service Boston/Norton MA
419 AM EDT Tue May 12 2026
Forecast is based on ignition time of 0600 EDT on May 12.
If conditions become unrepresentative, contact the National
Weather Service.
.DISCUSSION...
A few morning clouds will give way to full sunshine across
southwestern Cape Cod today. Surface winds could become variable
by mid morning due to localized sea breezes. Increasing clouds
late Tuesday night into Wednesday morning, rain arrives late
Wednesday into Thursday.
.TODAY...
Sky/weather.........Partly sunny then becoming sunny.
CWR.................0 percent.
Max temperature.....Around 61.
Min humidity........39 percent.
Dewpoint............37.
Min apparent temp...36.
Surface winds (mph).North winds 6 to 8 mph shifting to the east
around 7 mph late in the afternoon, then
shifting to the south 7 to 8 mph late in the
afternoon.
Wind (20 ft)........North winds around 8 mph decreasing to 6 to 8
mph until late afternoon, then shifting to the
east around 7 mph late in the afternoon
shifting to the south 7 to 8 mph late in the
afternoon.
Mixing height.......6700 ft AGL.
Transport winds.....North 12 to 16 mph shifting to the southwest
around 13 mph late in the afternoon.
Smoke dispersal.....Fair (14000 knot-ft) early in the morning
increasing to excellent (89000 knot-ft) in the
afternoon.
LVORI...............3.
ADI.................21 early in the morning increasing to 105 in
the afternoon.
CEILING (KFT).......9.0 decreasing to 6.0.
TIME (EDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........65 41 19 15 12 7 12 17 21 25 28 32
Weather cov.....
Weather type....
Tstm cov........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Temp............41 41 50 53 56 58 59 60 60 61 61 60
Dewpoint........38 39 39 38 38 37 36 36 36 36 37 38
RH..............89 92 66 57 51 45 42 41 41 39 41 44
Heat index (F)..36 36 47 53 56 58 59 60 60 61 61 60
20 FT wind dir..N N N N N N N N NE E SE S
20 FT wind spd..8 8 8 8 8 8 8 7 6 7 7 8
20 FT wind gust.15 15 16 15 15 14 13 12 9 10 10 12
Surface wnd dir.N N N N N N N N NE E SE S
Surface wnd spd.8 8 8 8 8 8 8 7 6 7 7 8
Surface wnd gst.15 15 16 15 15 14 13 12 9 10 10 12
Mix hgt (kft)...1.2 1.9 2.7 3.9 5.0 6.2 6.4 6.5 6.7 5.8 4.9 3.9
Transp wind dir.N N N N N N N N N NW NW SW
Transp wind spd.14 15 15 16 16 16 16 15 14 12 12 13
LVORI...........4 4 1 1 1 1 1 1 1 1 1 1
ADI.............21 37 51 75 93 105 105 105 105 75 65 60
Vrate kt-ft/1K..14 25 35 54 70 87 89 85 81 58 49 43
Ventrate Cat....PR PR PR FR GD GD GD GD GD FR FR FR
Ceiling (kft)...9.0 7.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0
.TONIGHT...
Sky/weather.........Partly cloudy then becoming mostly cloudy then
becoming partly cloudy then becoming mostly
cloudy.
CWR.................0 percent.
Min temperature.....Around 48.
Max humidity........83 percent.
Dewpoint............41 increasing to 43 around midnight.
Max apparent temp...59.
Surface winds (mph).Southwest winds 6 to 8 mph decreasing to around
6 mph after midnight.
Wind (20 ft)........Southwest winds 6 to 7 mph.
Mixing height.......300 ft AGL.
Transport winds.....Southwest 10 to 12 mph shifting to the west
after midnight.
Smoke dispersal.....Fair (28000 knot-ft) early in the evening
decreasing to poor (2700 knot-ft) late in the
night.
LVORI...............3.
ADI.................5 to 40.
CEILING (KFT).......6.0 increasing to 20.
TIME (EDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM
Sky (%).........27 17 20 28 32 50
Weather cov.....
Weather type....NONE NONE NONE NONE NONE NONE
Tstm cov........
CWR.............0 0 0 0 0 0
Temp............59 55 51 50 49 48
Dewpoint........39 42 43 44 44 43
RH..............47 61 74 80 83 83
Heat index (F)..59 55 51 48 47 45
20 ft wind......S 8 S 7 SW 6 SW 6 SW 6 SW 6
20 ft wind gust.12 13 12 12 12 10
Surface wind....S 8 S 7 SW 6 SW 6 SW 6 SW 6
Surface wnd gst.12 13 12 12 12 10
Mix hgt (ft)....2800 600 400 300 300 300
Transport wind..S 12 S 12 SW 10 SW 10 W 12 W 12
LVORI...........1 3 3 4 4 4
ADI.............40 5 5 5 5 8
Vrate kt-ft/1K..28 6 4 3 3 3
Ventrate Cat....POOR POOR POOR POOR POOR POOR
Ceiling (kft)...6.0 6.0 11 15 20 20
.WEDNESDAY...
Sky/weather.........Mostly cloudy.
CWR.................0 percent.
Max temperature.....Around 63.
Min humidity........56 percent.
Dewpoint............44.
Max apparent temp...61.
Surface winds (mph).Southwest winds 6 to 15 mph shifting to the
south 14 to 15 mph with gusts to around 26 mph
late in the afternoon.
Wind (20 ft)........South winds 7 to 15 mph with gusts to around 26
mph.
Mixing height.......2800 ft AGL.
Transport winds.....Southwest 9 to 18 mph shifting to the south 20
to 24 mph in the late morning and afternoon.
Smoke dispersal.....Poor (5100 knot-ft) early in the morning
increasing to good (50500 knot-ft) in the
afternoon.
LVORI...............3.
ADI.................9 early in the morning increasing to 64 in the
afternoon.
CEILING (KFT).......20 decreasing to 7.0.
TIME (EDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM
Sky (%).........62 59 75 89 82 82
Weather cov.....
Weather type....NONE NONE NONE NONE NONE NONE
Tstm cov........
CWR.............0 0 0 0 0 0
Temp............49 54 58 60 60 60
Dewpoint........43 45 45 45 45 46
RH..............80 71 62 58 58 60
Heat index (F)..47 54 58 60 60 60
20 ft wind......SW 6 SW 7 SW 9 S 13 S 15 S 15
20 ft wind gust.12 14 17 22 25 26
Surface wind....SW 6 SW 7 SW 9 S 13 S 15 S 15
Surface wnd gst.12 14 17 22 25 26
Mix hgt (ft)....600 1300 2400 2800 2200 2300
Transport wind..SW 9 SW 15 SW 20 SW 21 S 22 S 24
LVORI...........4 3 1 1 1 1
ADI.............9 26 54 64 44 51
Vrate kt-ft/1K..5 17 41 51 41 49
Ventrate Cat....POOR POOR FAIR FAIR FAIR FAIR
Ceiling (kft)...20 15 10 8.0 7.0 7.0
$$
Forecaster...Dooley
Requested by...Alex Entrup
Type of request...PRESCRIBED
.TAG 2613401.0/BOX
.DELDT 05/12/26
.FormatterVersion 2.0.0
.EMAIL alex.entrup@mass.gov