903  
FNUS71 KBOX 130004  
FWSBOX  
 
SPOT FORECAST FOR STERLING FAIR...MEMA  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
804 PM EDT SAT SEP 12 2026  
 
FORECAST IS BASED ON FORECAST START TIME OF 0600 EDT ON SEPTEMBER 13.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL  
WEATHER SERVICE.  
   
DISCUSSION  
 
SHOWERS WITH PERIODS OF HEAVY DOWNPOURS ARE EXPECTED STARTING  
AFTER 8/9 AM TOMORROW, WITH THE HIGHEST CHANCES FOR THE PERIODS OF  
HEAVY RAIN PEAKING AROUND 11 AM/NOON. THIS SHOULD CLEAR OUT MORE  
TOWARDS THE EVENING HOURS, GENERALLY AFTER 5 PM. WITH REGARDS TO  
TOTALS, CURRENTLY EXPECTING AROUND 2" OVER THE COURSE OF THE LATE  
MORNING THROUGH THE EVENING HOURS. ANY HIGHLY LOCALIZED HIGHER  
TOTALS CANNOT BE ENTIRELY RULED OUT, THOUGH. A FEW THUNDERSTORMS  
ARE POSSIBLE, PARTICULARLY IN THE AFTERNOON.  
   
SUNDAY  
 
SKY/WEATHER.........CLOUDY. SHOWERS AND ISOLATED THUNDERSTORMS  
THROUGH THE DAY.  
CHANCE OF PCPN......100 PERCENT.  
CHANCE OF RAIN......99 PERCENT.  
CHANCE OF THUNDER...23 PERCENT.  
BEGIN/END OF PCPN...  
MAX TEMPERATURE.....AROUND 72.  
MIN HUMIDITY........93 PERCENT.  
SURFACE WINDS (MPH).LIGHT WINDS IN THE MORNING BECOMING SOUTHEAST  
AROUND 5 MPH, THEN SHIFTING TO THE EAST EARLY  
IN THE AFTERNOON BECOMING LIGHT.  
RAINFALL AMOUNT.....0.84 INCHES.  
PCPN AMOUNT.........0.84 INCHES.  
MIXING HEIGHT.......1000 FT AGL.  
TRANSPORT WINDS.....SOUTH 7 TO 9 MPH SHIFTING TO THE EAST AROUND 9  
MPH EARLY IN THE AFTERNOON, THEN SHIFTING TO  
THE SOUTHEAST LATE IN THE AFTERNOON SHIFTING TO  
THE NORTHEAST 8 TO 10 MPH LATE IN THE  
AFTERNOON.  
SMOKE DISPERSAL.....POOR (3000 KNOT-FT).  
LVORI...............8.  
ADI.................1 TO 12.  
 
TIME (EDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........87 80 91 88 100 94 92 92 95 87 94 94  
WEATHER COV.....SCH CHC LKY DEF DEF DEF DEF LKY CHC CHC SCH  
WEATHER TYPE....RW RW RW RW RW RW RW RW RW RW RW  
TSTM COV........ISO ISO ISO ISO ISO ISO ISO ISO ISO  
CHC OF PCPN (%).20 30 70 80 100 90 80 60 50 40 20 10  
CHC OF RAIN (%).20 50 60 90 90 100 100 100 100 60 50 30  
CHC OF THDR (%).10 10 20 20 20 20 20 20 20 20 20 10  
TEMP............61 61 63 64 66 67 68 68 70 70 70 71  
RH..............93 97 97 100 100 100 100 100 97 97 100 97  
SURFACE WND DIR.S S S S SE SE E E E E NE NE  
SURFACE WND SPD.2 2 3 3 3 5 5 5 5 3 3 3  
SURFACE WND GST.7 8 8 9 10 10 10 10 10 8 7 6  
MIX HGT (KFT)...0.4 0.5 0.5 0.8 0.8 0.9 1.0 1.0 0.9 0.8 0.9 0.9  
TRANSP WIND DIR.S SW S SW S S S SE E SE NE N  
TRANSP WIND SPD.8 8 8 8 7 8 9 9 9 9 10 8  
LVORI...........6 6 6 8 8 10 10 10 10 8 7 6  
ADI.............9 9 9 9 8 1 1 1 1 11 12 9  
VRATE KT-FT/1K..3 3 4 5 5 7 8 8 7 7 8 6  
VENTRATE CAT....PR PR PR PR PR PR PR PR PR PR PR PR  
   
SUNDAY NIGHT  
 
SKY/WEATHER.........MOSTLY CLOUDY. SLIGHT CHANCE OF SHOWERS EARLY  
IN THE MORNING.  
CHANCE OF PCPN......20 PERCENT.  
CHANCE OF RAIN......29 PERCENT.  
CHANCE OF THUNDER...9 PERCENT.  
BEGIN/END OF PCPN...  
MIN TEMPERATURE.....AROUND 60.  
MAX HUMIDITY........100 PERCENT.  
SURFACE WINDS (MPH).LIGHT WINDS BECOMING WEST 5 TO 6 MPH EARLY IN  
THE MORNING.  
RAINFALL AMOUNT.....0.08 INCHES.  
PCPN AMOUNT.........0.08 INCHES.  
MIXING HEIGHT.......400 FT AGL.  
TRANSPORT WINDS.....NORTH AROUND 8 MPH SHIFTING TO THE EAST AROUND  
7 MPH EARLY IN THE EVENING, THEN SHIFTING TO  
THE NORTH EARLY SHIFTING TO THE WEST 6 TO 10  
MPH IN THE LATE EVENING AND EARLY MORNING  
SHIFTING TO THE NORTHWEST AROUND 12 MPH.  
SMOKE DISPERSAL.....POOR (2200 KNOT-FT).  
LVORI...............8.  
ADI.................3 TO 9.  
 
TIME (EDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........79 75 67 70 66 64 53 54 55 73 83 88  
WEATHER COV..... SCH SCH SCH  
WEATHER TYPE.... RW RW RW  
TSTM COV........  
CHC OF PCPN (%).10 0 0 0 0 0 0 0 10 20 20 20  
CHC OF RAIN (%).30 30 30 10 10 10 10 10 10 20 20 20  
CHC OF THDR (%).10 0 0 0 0 0 0 0 10 10 10 10  
TEMP............70 70 68 66 66 66 65 65 65 65 63 62  
RH..............97 97 97 100 100 97 100 97 97 93 97 97  
SURFACE WND DIR.N NW W SW W W W W W W W W  
SURFACE WND SPD.2 1 1 2 2 3 3 3 5 5 6 6  
SURFACE WND GST.5 3 3 5 6 7 8 9 10 12 13 14  
MIX HGT (KFT)...0.7 0.5 0.4 0.4 0.4 0.5 0.5 0.5 0.5 0.4 0.4 0.5  
TRANSP WIND DIR.N E N SW W W W W W W NW NW  
TRANSP WIND SPD.8 7 7 6 7 8 8 9 10 10 12 12  
LVORI...........6 9 8 10 9 8 9 8 7 6 6 6  
ADI.............9 3 3 3 3 4 4 4 7 7 8 8  
VRATE KT-FT/1K..5 3 2 2 3 3 3 4 4 4 4 5  
VENTRATE CAT....PR PR PR PR PR PR PR PR PR PR PR PR  
 
 
FORECASTER...BRW  
REQUESTED BY...D LEAVITT  
TYPE OF REQUEST...OTHER  
.TAG 2621738.0/BOX  
.DELDT 09/12/26  
.FORMATTERVERSION 2.0.0  
.EMAIL DANIEL.LEAVITT@MASS.GOV  
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