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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 10, 2018 
ALL TIMES ARE IN EASTERN STANDARD TIME

DRY AND CLEAR WITH GOOD VISIBILITY ATOP
GREAT BLUE HILL....

Skies remained clear all day, with only a few 
distant cumulus being observed between 7 A.M. and
1 P.M. Visibility increased since this morning, 
reaching a visibility of 70 miles at 1 P.M. A 
visibility of 40 miles was observed at 7 A.M. and
10 A.M., due to a distant haze. Humidity dropped
from 78% at 7 A.M. to 43% this afternoon. The max
temperature so far today is 36F, 5 degrees below 
the daily normal of 41F. The low since midnight is
22F, 4 degrees below the daily normal minimum of 26F.
 

BHO Wettest Novembers, inches (1886-2018):

1) 10.31 in 2018
2) 9.78 in 1983
3) 9.29 in 1945
4) 9.17 in 1972
5) 8.95 in 1895
6) 8.93 in 1988
7) 8.79 in 1963
 
BHO Wettest Falls (Sep-Nov), inches (1886-2018):

1) 25.41 in 2018 
2) 23.18 in 2005
3) 23.13 in 1996
4) 22.47 in 1888
5) 20.65 in 2011
6) 20.64 in 1932
7) 20.08 in 1962
    

PRELIMINARY STATS FOR NOVEMBER 2018

TEMPERATURE, Deg. F
Avg. Max. 45.2 [-4.8]
Avg. Min. 32.4 [-1.1]
Mean 38.8 [-2.9]
24-hour corrected mean: 38.6
Max. for month: 65F on the 1st and 2nd
Min. for month: 9F on the 22nd and 23rd

HEATING DEGREE DAYS
Total heating units: 776 [+78]
Total for the season: 1320 [+351]
Total for last season: 969

PRECIPITATION, Inches
Total: 10.31 in. [+5.55]
Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: 7.6 in. [+5.3]
Greatest in 24 hrs: N/A

WIND, mph
Avg. uncorrected wind speed: 13.1
Avg. corrected wind speed: 13.4
Prevailing wind direction: WNW at 15%	
Peak gust and direction: 59 W on the 3rd 

SUNSHINE:
Campbell-Stokes card minutes: 6144 minutes of possible 17010 or 36%
Astronomical total minutes:   6359 minutes of possible 17623 or 36%

Today's Observations:

7 A.M.
Weather: Clear, few cumulus NE-S
Temperature: 23F; Dew Point: 17F; Wind: NNW at 10G14 kts  
Sea-level pressure: 30.07 ins. Hg, steady       
Visibility: 40 miles, distant haze 
6-hr Max temp: 23F
6-hr Min temp: 22F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.   
BHO SA 1155 CLR 40 182/23/17/3310G14/007/ FEW CU NE-S 
DSNT HZ ALQDS/ 8/100 50000 10023 20022

10 A.M.
Weather: Clear, few cumulus NE-S 
Temperature: 32F; Dew Point: 16F; Wind: NNW at 10G16 kts  
Sea-level pressure: 30.11 ins. Hg, rising steadily
Visibility: 40 miles, distant haze  
3-hr Precip: 0.00 ins. 
BHO SA 1455 CLR 40 197/32/16/3410G16/011/ FEW CU NE-S 
DSNT HZ ALQDS/ 8/100 53015

1 P.M.
Weather: Clear, few distant cumulus N-S     
Temperature: 36F; Dew Point: 16F; Wind: NNW at 7G12 kts  
Sea-level pressure: 30.14 ins. Hg, falling steadily       
Visibility: 70 miles
6-hr Max temp: 36F
6-hr Min temp: 22F
6-hr Precip: 0.00 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.   
BHO SA 1755 CLR 70 206/36/16/3307G12/014/ FEW DSNT CU N-S/ 
8/100 55009 10036 20022

 
SUMMARY FOR SUNDAY, DECEMBER 9, 2018 

TEMPERATURE (DEGREES F)
MAX.....34   NORMAL.....41
MIN.....17   NORMAL.....26
MEAN....26   NORMAL.....34

DEPARTURE FROM 30-YEAR NORMAL........................-8
TOTAL DEPARTURE FOR THE MONTH.......................-27 [-2.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............39   DEPARTURE.........+8
TOTAL HEATING UNITS FOR THE MONTH.............296   DEPARTURE........+27
TOTAL HEATING UNITS FOR THE SEASON...........1616   DEPARTURE........+85
TOTAL HEATING UNITS LAST SEASON TO DATE......1209   DIFFERENCE......+407

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................23 WSW AT 5:51 P.M.
                   AERO.........................21 WSW AT 5:38 P.M. 
                   ASOS.........................23 SW  AT 5:52 P.M. 
                   DAVIS........................23 W   AT 1:43 P.M. RMY 22
FASTEST MILE FOR YESTERDAY......................16 SW  AT 3:07 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...................17 SW  AT 3:27 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................17 WSW AT 3:08 P.M.
AVERAGE WIND SPEED AND DIRECTION..............11.1 WSW
                   ASOS.......................11.1
                   DAVIS......................11.6 WSW [258 deg.]   

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE.......-0.16
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.04  DEPARTURE.......-0.44
                         ASOS..............1.78
TOTAL PRECIPITATION FOR THE YEAR..........64.41  DEPARTURE......+14.59
                         ASOS.............67.41

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........-0.4
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE........-2.8
TOTAL SNOWFALL FOR THE SEASON...............7.6  DEPARTURE........+2.2


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 65/49/57/+11/0.00/006/01         25 SSW AERO 24 SSW RMY N/A
11/02 65/52/59/+13/0.37/000/00         37 SSW AERO 41 SSW RMY N/A
11/03 64/42/53/+7/1.43/148/24          59 W   AERO 60 W   RMY 58
11/04 52/37/45/0/0.00/588/96           31 W   AERO 30 W   RMY N/A
11/05 49/40/45/0/0.34/000/00           30 ENE AERO 29 ENE RMY 28
11/06 58/45/52/+7/0.97/000/00          29 SSW AERO 29 SSW RMY 31
11/07 60/50/55/+10/0.00/593/98         30 WSW AERO 30 WSW RMY 32
11/08 52/37/45/+1/0.00/470/78          29 WNW AERO 26 WNW RMY 23
11/09 48/34/41/-3/1.23/240/40          43 E   AERO 40 E   RMY 42
11/10 45/32/39/-5/0.55/000/00          45 W   AERO 47 WNW RMY 46
11/11 43/30/37/-6/0.00/596/100         32 WNW AERO 30 W   RMY 32
11/12 48/27/38/-5/0.00/475/80          18 SW  AERO 18 SW  RMY N/A
11/13 52/37/45/+2/1.07/000/00          44 WNW AERO 44 WNW RMY 48
11/14 37/20/29/-13/0.00/471/80         45 WNW AERO 50 WNW RMY 50
11/15 30/19/25/-17/0.71/000/00         33 E   AERO 36 E   RMY N/A
11/16 41/30/36/-6/0.69/000/00          43 E   AERO 44 ENE RMY N/A
11/17 45/34/40/-1/0.00/111/19          28 W   AERO 27 W   RMY 28
11/18 40/30/35/-6/0.00/157/27          21 W   AERO 21 W   RMY M
11/19 38/33/36/-5/0.03/000/00          16 E   AERO 14 E   RMY N/A
11/20 38/31/35/-5/0.46/000/00          30 NE  AERO 30 NE  RMY N/A
11/21 39/20/30/-10/0.00/081/14         40 WNW AERO 46 WNW RMY 47
11/22 20/09/15/-25/0.00/567/99         36 NW  AERO 41 NW  RMY 42
11/23 30/09/20/-19/0.00/548/96         25 SW  AERO 25 SW  RMY 27
11/24 43/24/34/-5/0.00/302/53          27 SW  AERO 27 ESE RMY N/A
11/25 43/40/42/+3/0.94/000/00          39 ENE AERO 39 ENE RMY 39
11/26 44/39/42/+4/0.92/000/00          45 E   AERO 44 E   RMY 45
11/27 45/33/39/+1/0.60/141/25          44 ENE AERO 44 ENE RMY N/A
11/28 39/31/35/-3/0.00/180/32          37 WNW AERO 41 WNW RMY 42
11/29 43/30/37/0/0.00/315/56           40 NW  AERO 41 NW  RMY 44 
11/30 39/27/33/-4/0.00/370/66          18 NW  AERO 16 NW  RMY N/A

DAILY RECORDS FOR NOVEMBER 2017

11/22/18: DAILY RECORD LOW MAXIMUM TEMPERATURE OF 20F,
          BREAKS PREVIOUS RECORD OF 26F SET IN 1972 AND 2008
11/22/18: DAILY RECORD LOW MINIMUM TEMPERATURE OF 9F,
          BREAKS PREVIOUS RECORD OF 12F SET IN 1987
11/23/18: DAILY RECORD LOW MINIMUM TEMPERATURE OF 9F,
          TIES PREVIOUS RECORD OF 9F SET IN 1888


PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 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

12/01 41/28/35/-2/0.00/.../..          20 NNW AERO 18 NNW RMY N/A
12/02 52/35/44/+8/1.04/.../..          28 ESE AERO 25 ESE RMY 27
12/03 54/38/46/+10/0.00/.../..         35 W   AERO 35 W   RMY 38 
12/04 38/23/31/-4/0.00/.../..          30 WNW AERO 31 WNW RMY 33
12/05 33/18/26/-9/0.00/.../..          16 NNW AERO 15 NNW RMY N/A
12/06 37/24/31/-4/0.00/.../..          29 W   AERO 28 W   RMY 30
12/07 37/21/29/-5/0.00/.../..          29 NW  AERO 29 NW  RMY 32
12/08 27/15/21/-13/0.00/.../..         28 NW  AERO 27 NW  RMY 29
12/09 34/17/26/-8/0.00/.../..          23 SSW AERO 21 SSW RMY 22

12/10 Low temp since midnight is 22F; normal low is 26F


DAILY EXTREMES
Temperature and precipitation records back to 1885, and

RECORDS FOR DECEMBER 10
HIGH 62 IN 1946
LOW -6 IN 1902
PRECIP 1.67 INS. IN 1907
SNOWFALL 6.0 INS. IN 1905
PEAK GUST 66e SW IN 1940

RECORDS FOR DECEMBER 11
HIGH 63 IN 1911
LOW -1 IN 1988
PRECIP 2.36 INS. IN 1992
SNOWFALL 6.0 INS. IN 1894
PEAK GUST 78 S IN 1969

TODAY'S REPORT PREPARED BY: Benjamin Turner