832  
FNUS71 KBOX 171259  
FWSBOX  
 
SPOT FORECAST FOR LYMAN...MASS DCR  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
859 AM EDT THU APR 17 2025  
 
FORECAST IS BASED ON IGNITION TIME OF 0951 EDT ON APRIL 17.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL  
WEATHER SERVICE.  
   
DISCUSSION
 
 
BOURNE/WAREHAME AREA DISCUSSION (-70.63W, 41.76N)  
 
STEADY WEST TO WEST-NORTHWEST WINDS THURSDAY AFTERNOON AROUND 10  
KNOTS WITH MODEST GUSTS GENERALLY LESS THAN 20 KNOTS. LOW  
DEWPOINTS IN THE MID 20S WILL SUPPORT LOW RH VALUES BOTTOMING OUT  
BETWEEN 25 AND 30 PERCENT BETWEEN 2 AND 5 PM THURSDAY AFTERNOON.  
MIXING HEIGHTS AROUND 3000 FEET THIS MORNING GRADUALLY RISE AND MAX  
OUT BETWEEN 5500 AND 6000 FEET THIS AFTERNOON. NO PRECIP IN THE  
FORECAST.  
 
   
REST OF TODAY
 
 
SKY/WEATHER.........SUNNY.  
CWR.................0 PERCENT.  
MAX TEMPERATURE.....AROUND 57.  
MIN HUMIDITY........35 PERCENT.  
DEWPOINT............31.  
MIN APPARENT TEMP...38.  
SURFACE WINDS (MPH).WEST WINDS 8 TO 9 MPH.  
WIND (20 FT)........WEST WINDS 8 TO 9 MPH.  
MIXING HEIGHT.......5700 FT AGL.  
TRANSPORT WINDS.....WEST 17 TO 21 MPH.  
SMOKE DISPERSAL.....GOOD (45800 KNOT-FT) EARLY IN THE MORNING  
INCREASING TO EXCELLENT (103200 KNOT-FT) IN THE  
AFTERNOON.  
LVORI...............1.  
ADI.................66 TO 67 INCREASING TO 78 EARLY, THEN  
INCREASING TO 95 EARLY IN THE AFTERNOON  
DECREASING TO 76 EARLY IN THE AFTERNOON  
INCREASING TO 88 TO 91.  
CEILING (KFT).......25 DECREASING TO 20 AROUND NOON, THEN  
INCREASING TO 25 LATE IN THE AFTERNOON.  
 
TIME (EDT) 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........4 12 15 10 5 7 7 5 4  
WEATHER COV.....  
WEATHER TYPE....  
TSTM COV........  
CWR.............0 0 0 0 0 0 0 0 0  
TEMP............43 47 50 53 54 56 56 56 56  
DEWPOINT........31 30 32 33 33 32 32 31 29  
RH..............62 51 50 46 45 40 40 38 35  
HEAT INDEX (F)..38 43 47 53 54 56 56 56 56  
20 FT WIND DIR..W W W W W W W W W  
20 FT WIND SPD..8 8 8 8 9 9 9 9 9  
20 FT WIND GUST.16 16 15 16 16 16 16 16 17  
SURFACE WND DIR.W W W W W W W W W  
SURFACE WND SPD.8 8 8 8 9 9 9 9 9  
SURFACE WND GST.16 16 15 16 16 16 16 16 17  
MIX HGT (KFT)...2.7 3.1 3.8 4.4 5.0 5.7 5.7 5.5 5.3  
TRANSP WIND DIR.W W W W W W W W NW  
TRANSP WIND SPD.20 17 17 18 18 21 21 21 21  
LVORI...........1 1 1 1 1 1 1 1 1  
ADI.............66 67 78 95 76 90 91 89 88  
VRATE KT-FT/1K..46 47 56 70 80 102 103 99 96  
VENTRATE CAT....FR FR FR GD GD VGD VGD GD GD  
CEILING (KFT)...25 20 20 20 20 25 25 25 25  
   
TONIGHT
 
 
SKY/WEATHER.........MOSTLY CLEAR.  
CWR.................0 PERCENT.  
MIN TEMPERATURE.....AROUND 34.  
MAX HUMIDITY........75 PERCENT.  
DEWPOINT............28.  
MIN APPARENT TEMP...34.  
SURFACE WINDS (MPH).WEST WINDS 5 TO 8 MPH EARLY IN THE EVENING  
BECOMING LIGHT.  
WIND (20 FT)........WEST WINDS 5 TO 6 MPH EARLY IN THE EVENING  
BECOMING LIGHT.  
MIXING HEIGHT.......300 FT AGL.  
TRANSPORT WINDS.....NORTHWEST 10 TO 18 MPH DECREASING TO 7 TO 8 MPH  
AFTER MIDNIGHT.  
SMOKE DISPERSAL.....GOOD (55500 KNOT-FT) EARLY IN THE EVENING  
DECREASING TO POOR (2000 KNOT-FT) LATE IN THE  
NIGHT.  
LVORI...............3.  
ADI.................78 DECREASING TO 3 TO 7.  
CEILING (KFT).......25 DECREASING TO 20 AFTER MIDNIGHT, THEN  
INCREASING TO 25 EARLY IN THE MORNING.  
 
TIME (EDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........2 3 5 4 17 20 15 10 5 4 4 3  
WEATHER COV.....  
WEATHER TYPE....  
TSTM COV........  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
TEMP............54 50 47 45 43 42 41 38 37 36 35 34  
DEWPOINT........30 30 30 30 30 30 29 29 28 28 28 27  
RH..............40 46 51 55 60 62 62 70 70 72 75 75  
HEAT INDEX (F)..54 48 45 44 41 40 41 38 37 36 35 34  
20 FT WIND DIR..W W W W W W W W W W W W  
20 FT WIND SPD..8 6 5 3 3 3 2 2 2 2 2 2  
20 FT WIND GUST.15 13 12 10 9 8 7 7 6 6 6 6  
SURFACE WND DIR.W W W W W W W W W W W W  
SURFACE WND SPD.8 6 5 3 3 3 2 2 2 2 2 2  
SURFACE WND GST.15 13 12 10 9 8 7 7 6 6 6 6  
MIX HGT (KFT)...3.5 2.0 0.7 0.7 0.5 0.5 0.4 0.4 0.4 0.4 0.4 0.3  
TRANSP WIND DIR.NW NW NW W W NW NW NW W NW NW W  
TRANSP WIND SPD.18 16 14 13 12 10 8 7 8 8 7 7  
LVORI...........1 2 2 3 3 3 3 3 3 3 4 4  
ADI.............78 7 6 6 5 5 4 3 4 4 3 3  
VRATE KT-FT/1K..56 28 9 7 5 5 3 2 3 3 2 2  
VENTRATE CAT....FR PR PR PR PR PR PR PR PR PR PR PR  
CEILING (KFT)...25 25 25 25 25 25 25 20 20 20 25 25  
   
FRIDAY
 
 
SKY/WEATHER.........MOSTLY SUNNY THEN BECOMING MOSTLY CLOUDY.  
CWR.................0 PERCENT.  
MAX TEMPERATURE.....AROUND 57.  
MIN HUMIDITY........40 PERCENT.  
DEWPOINT............30 INCREASING TO 34 IN THE AFTERNOON.  
MIN APPARENT TEMP...35.  
SURFACE WINDS (MPH).LIGHT WINDS BECOMING SOUTHWEST 6 TO 12 MPH IN  
THE LATE MORNING AND AFTERNOON.  
WIND (20 FT)........SOUTHWEST WINDS 5 TO 12 MPH EARLY IN THE  
MORNING BECOMING LIGHT, THEN BECOMING SOUTHWEST  
6 TO 12 MPH IN THE LATE MORNING AND AFTERNOON.  
MIXING HEIGHT.......2800 FT AGL.  
TRANSPORT WINDS.....WEST 6 TO 12 MPH INCREASING TO SOUTHWEST AROUND  
25 MPH.  
SMOKE DISPERSAL.....POOR (1800 KNOT-FT) EARLY IN THE MORNING  
INCREASING TO GOOD (45800 KNOT-FT) IN THE  
AFTERNOON.  
LVORI...............3.  
ADI.................6 TO 15 INCREASING TO 31, THEN INCREASING TO 52  
TO 60 EARLY INCREASING TO 59 TO 63 EARLY IN THE  
AFTERNOON DECREASING TO 43 TO 44.  
CEILING (KFT).......25 DECREASING TO 12.  
 
TIME (EDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........2 2 1 8 15 22 28 34 40 50 61 71  
WEATHER COV.....  
WEATHER TYPE....  
TSTM COV........  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
TEMP............35 36 41 47 51 55 56 57 57 56 55 54  
DEWPOINT........28 29 30 31 31 32 32 33 33 34 35 36  
RH..............75 75 65 53 46 41 40 40 40 43 47 50  
HEAT INDEX (F)..35 36 41 46 51 55 56 57 57 56 55 54  
20 FT WIND DIR..W W W SW SW SW SW SW SW SW SW SW  
20 FT WIND SPD..2 2 2 3 6 7 8 10 12 12 12 12  
20 FT WIND GUST.5 5 5 7 10 13 15 18 21 21 22 22  
SURFACE WND DIR.W W W SW SW SW SW SW SW SW SW SW  
SURFACE WND SPD.2 2 2 3 6 7 8 10 12 12 12 12  
SURFACE WND GST.5 5 5 7 10 13 15 18 21 21 22 22  
MIX HGT (KFT)...0.3 0.4 0.5 1.5 2.1 2.8 2.6 2.4 2.2 2.0 1.8 1.6  
TRANSP WIND DIR.W W W SW SW SW SW SW SW SW SW SW  
TRANSP WIND SPD.7 6 6 8 12 15 18 21 24 24 24 25  
LVORI...........4 4 3 2 1 1 1 1 1 1 1 1  
ADI.............7 6 6 15 31 52 60 58 63 59 44 43  
VRATE KT-FT/1K..2 2 2 10 22 37 42 43 46 42 38 35  
VENTRATE CAT....PR PR PR PR PR PR FR FR FR FR PR PR  
CEILING (KFT)...25 25 25 25 25 25 25 25 20 20 15 12  
 

 
FORECASTER...RM  
REQUESTED BY...MICHAEL MARQUARDT  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2510163.2/BOX  
.DELDT 04/17/25  
.FORMATTERVERSION 2.0.0  
.EMAIL MICHAEL.MARQUARDT@MASS.GOV  
 
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