BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, DECEMBER 6, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME
 
LOW PRESSURE OVERNIGHT BRINGS HIGH WINDS AND
HEAVY RAINFALL TO GREAT BLUE HILL...

Southeasterly winds picked up yesterday afternoon 
and peaked at 62 MPH just after 11:00 PM. Soon 
after we had our high for the day at 58F. Today
just after 6:00 AM winds shifted and began coming 
for the West/WNW. This has cooled the hill and 
temperatures began dropping. We have observed
a 17 degree decrease in temperature since midnight.
The rain, which was heavy at times, began before 
noon yesterday and ended just before 7:00 AM today.
We measures 0.72 inches during this rainstorm.   
Visibility was limited in the morning to only 35 
miles due to a distant fog. By 1:00 PM the fog
had cleared and we could see 80 miles.

PRELIMINARY STATS FOR NOVEMBER 2017
 
TEMPERATURE, Deg. F
Avg. Max. 49.8 [-0.2]
Avg. Min. 32.9 [-0.6]
Mean      41.4 [-0.3]
24-hour corrected mean: 41.7 
Max. for month: 74F on 3rd 
Min. for month: 18F on 11th 
 
HEATING DEGREE DAYS
Total heating units: 701 [+3] 
Total for the season: 969 [-292] 
Total for last season: 1030

PRECIPITATION, Inches
Total: 2.04 [-2.72] 
Greatest in 24 hrs: 0.87 in. on the 22nd 
 
WIND, mph
Avg. uncorrected wind speed: 12.7 
Avg. corrected wind speed: 13.0 
Prevailing wind direction: WNW at 12%
Peak gust and direction: 50 W on 19th
 
SUNSHINE:
Campbell-Stokes card minutes: 9,108 minutes of possible 17,010 or 54%
Astronomical total minutes: 9,431 minutes of possible 17,610 or 54%

BHO Warmest Fall (Sep-Nov) 24-hour Corrected Mean Temperature, deg F (1885-2017):

1) 55.3 in 2017
2) 55.1 in 2011
3) 54.8 in 1931
   54.8 in 2015
5) 54.3 in 1946
   54.3 in 2001

Today's Observations:

7 A.M.
Weather: Very light rain, overcast stratus, few stratus
fractus in all directions  
Temperature: 47F; Dew Point: 45F; Wind: W at 14G22 kts,
Peak Wind: 31 kts (36 MPH) W at 6:13 AM
Sea-level pressure: 29.81 ins. Hg, rising, then more quickly  
Visibility: 35 miles, distant fog in all directions  
6-hr Max temp: 56F
6-hr Min temp: 47F
24-hr precip: 0.72 ins.
BHO SA 1155 E40 OVC 35L- 096/47/45/2714G22/981/ FEW STFA ALQDS
PCPN VRY LGT DSNT FG ALQDS PK WND 2731/13/ 8/6// MANUAL 70072 
ASOS 70079 53017 10056 20047   

10 A.M.
Weather: Broken altostratus, few altocumulus WSW-ENE
Temperature: 42F; Dew Point: 35F; Wind: WNW at 13G22 kts 
Sea-level pressure: 29.88 ins. Hg, rising, then more slowly  
Visibility: 35 miles, distant fog in all directions
3-hr precip: 0.00 ins. 
BHO SA 1455 E180 BKN 35 119/42/35/2913G22/988/ FEW AC WSW-ENE 
DSNT FG ALQDS/ 8/020 53023  

1 P.M.
Weather: Few altocumulus ESE-S, scattered cirrus, broken 
cirrostratus
Temperature: 42F; Dew Point: 27F; Wind: W at 14G18 kts 
Sea-level pressure: 29.85 ins. Hg, falling then steady
Visibility: 80 miles 
6-hr Max temp: 47F
6-hr Min temp: 39F
6-hr precip: 0.00 ins.
BHO SA 1755 200 SCT 250 BKN 80 110/42/27/2614G18/985/ FEW 
AC ESE-S/ 8/086 57009 10047 20039 

SUMMARY FOR TUESDAY, DECEMBER 5, 2017
 
TEMPERATURE (DEGREES F)
MAX.....58   NORMAL.....43
MIN.....34   NORMAL.....27
MEAN....46   NORMAL.....35

DEPARTURE FROM 30-YEAR NORMAL..........................+11
TOTAL DEPARTURE FOR THE MONTH..........................+21 [+4.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............19  DEPARTURE.........-11
TOTAL HEATING UNITS FOR THE MONTH............125  DEPARTURE.........-21
TOTAL HEATING UNITS FOR THE SEASON..........1094  DEPARTURE........-314
TOTAL HEATING UNITS LAST SEASON TO DATE.....1164  DIFFERENCE........-70

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................62 S AT 11:05 P.M. 
                   AERO........................66 S AT 11:04 P.M.
                   ASOS........................67 S AT 11:05 P.M.
                   DAVIS.......................69 S AT 11:06 P.M. RMY 65
FASTEST MILE FOR YESTERDAY.....................52 S AT 11:15 P.M.    
MAXIMUM 2-MINUTE ASOS AVERAGE..................48 S AT 11:14 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................46 S AT 11:14 P.M.
AVERAGE WIND SPEED AND DIRECTION.............20.5 SE 
                   ASOS......................19.0
                   DAVIS.....................18.7 SSE [165 DEG.]
*** LAST OF MULTIPLE PEAK GUST
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.72  DEPARTURE......+0.55
                         ASOS..............0.79
TOTAL PRECIPITATION FOR THE MONTH..........0.76  DEPARTURE......-0.06
                         ASOS..............0.83
TOTAL PRECIPITATION FOR THE YEAR..........50.60  DEPARTURE......+1.25
                         ASOS...............N/A **
** ASOS annual total not available due to erroneous readings

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.......-0.3
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE.......-1.4
TOTAL SNOWFALL FOR THE SEASON...............0.0  DEPARTURE.......-4.0 

PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
M:    Missing data

11/01 53/39/46/0/0.00/167/27           25 SE  AERO 24 SE  RMY 25
11/02 71/49/60/+14/0.00/000/00         28 SSE AERO 25 SSE RMY 27
11/03 74/47/61/+15/T/350/57            35 WNW AERO 35 WNW RMY 38 
11/04 54/39/47/+2/0.00/545/89          31 NW  AERO 31 NW  RMY N/A 
11/05 61/46/54/+9/0.01/006/01          26 S   AERO 24 S   RMY N/A
11/06 64/47/56/+11/0.05/000/00         32 S   AERO 28 SSW RMY 35
11/07 46/35/41/-4/0.11/145/24          26 NNW AERO 23 N   RMY 26
11/08 3/34/39/-5/0.08/295/49           26 N   AERO 23 N   RMY 27 
11/09 50/31/41/-3/0.01/480/80          25 S   AERO 23 S   RMY N/A 
11/10 45/20/33/-11/0.00/586/98         46 WNW AER0 44 WNW RMY 46 
11/11 36/18/27/-16/0.00/589/99         28 WNW AERO 26 WNW RMY 28 
11/12 44/27/36/-7/0.00/302/51          13 E   AERO  9 S   RMY 14
11/13 40/35/38/-5/0.26/000/00          20 NNW AERO 17 NNW RMY 20
11/14 40/33/37/-5/T/000/00             18 N   AERO 15 N   RMY 18
11/15 43/31/37/-5/0.00/417/71          20 NE  AERO 15 NE  RMY N/A
11/16 51/37/44/+2/0.21/012/02          32 SE  AERO 32 SE  RMY N/A TSTM
11/17 42/30/36/-5/0.00/565/97          41 WNW AERO 43 WNW RMY 47
11/18 49/26/38/-3/0.08/168/29          35 SSW AERO 35 SSW RMY 39
11/19 58/34/46/+5/0.36/231/40          50 W   AERO 50 W   RMY 54
11/20 39/31/35/-5/0.00/462/80          48 WNW AERO 50 WNW RMY 44 
11/21 57/35/46/+6/0.00/506/88          46 SSW AERO 46 SSW RMY 48 
11/22 53/35/44/+4/0.87/000/00          37 NW  AERO 38 NW  RMY 41 
11/23 40/26/33/-6/0.00/571/100         26 NW  AERO 25 NW  RMY N/A 
11/24 49/29/39/0/0.00/558/98           28 SSW AERO 26 SSW RMY 29 
11/25 57/38/48/+9/0.00/523/92          29 SSW AERO 28 SSW RMY 31
11/26 46/33/40/+2/0.00/509/90          39 WNW AERO 41 WNW RMY 41 
11/27 44/24/34/-4/0.00/254/45          37 W   AERO 39 W   RMY 36 
11/28 45/19/32/-6/0.00/557/99          35 S   AERO 37 S   RMY N/A
11/29 58/34/46/+9/0.00/370/66          46 W   AERO 47 W   RMY 46 
11/30 43/26/35/-2/0.00/263/47          25 SSE AERO 25 NNW RMY 25

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
M:    Missing data

12/01 50/35/43/+6/0.04/.../..          28 NW  AERO 29 NW  RMY 30
12/02 42/29/36/0/0.00/.../..           20 NNW AERO 18 NNW RMY N/A
12/03 42/32/37/+1/0.00/.../..          14 N   AERO 10 N   RMY N/A 
12/04 43/32/38/+3/0.00/.../..          16 E   AERO 14 E   RMY N/A 
12/05 58/34/46/+11/0.00/.../..         62 S   AERO 66 S   RMY 65

12/06 Low temp since midnight is 40F; normal low is now 27F

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):      

RECORDS FOR DECEMBER 6
HIGH 70 IN 2001
LOW 5 IN 1901,1935
PRECIP 2.78 INS. IN 2003
SNOWFALL 17.0 INS. IN 2003
PEAK GUST 74 MPH NW IN 1981

RECORDS FOR DECEMBER 7
HIGH 74 IN 1998
LOW 6 IN 1906
PRECIP 1.67 INS. IN 1953
SNOWFALL 6.3 INS. IN 2003
PEAK GUST 76e SE IN 1976

TODAY'S REPORT PREPARED BY: Kaitlin Geagan