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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, DECEMBER 13, 2018 
ALL TIMES ARE IN EASTERN STANDARD TIME

HIGH PRESSURE, COOLER THAN AVERAGE WEATHER, 
AND LIGHT WIND WITH THE MOST CLOUD COVER 
OBSERVED THIS WEEK....

Visibility has been 40 miles on average 
due to a distant smoke layer. Wind has been light
and variable since this morning, with a max wind so 
far of 12 mph. Clouds have covered the majority of
the sky today, a difference compared to the almost
clear daytime conditions Monday through Wednesday.
This is despite high pressure and cold air from the
north and west. The max temperature so far is 31F, 
9 degrees below the daily normal of 40F. The low 
since midnight is 16F, 9 degrees below the daily 
normal minimum of 25F.  

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: 1.78 ins. on 9th-10th

SNOWFALL, Inches
Total: 7.6 in. [+5.3]
Greatest in 24 hrs: 7.5 ins. on 16th-17th 

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: Scattered altocumulus, few distant cumulus
Temperature: 16F; Dew Point: 7F; Wind: NNW at 7 kts  
Sea-level pressure: 30.47 ins. Hg, rising steadily       
Visibility: 40 miles, thin smoke layer in all directions 
6-hr Max temp: 18F
6-hr Min temp: 16F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.   
BHO SA 1155 E250 BKN 40 318/16/7/3507/047/ THN K LYR 
ALQDS/ 8/008 53023 10018 20016

10 A.M.
Weather: Broken altostratus  
Temperature: 25F; Dew Point: 13F; Wind: NNE at 3 kts,
Wind: Light and variable  
Sea-level pressure: 30.52 ins. Hg, rising steadily
Visibility: 40 miles, thin smoke layer in all directions  
3-hr Precip: 0.00 ins. 
BHO SA 1455 E200 BKN 40 336/25/13/0304/052/ THN K LYR 
ALQDS WND L/V/ 8/070 51018

1 P.M.
Weather: Broken altostratus     
Temperature: 30F; Dew Point: 19F; Wind: ESE at 4 kts,
Wind: Light and variable    
Sea-level pressure: 30.52 ins. Hg, steady       
Visibility: 40 miles, thin smoke layer in all directions
6-hr Max temp: 31F
6-hr Min temp: 16F
6-hr Precip: 0.00 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.   
BHO SA 1755 E200 BKN 40 336/30/19/1204/052/ THN K LYR 
ALQDS/ 8/070 51000 10031 20016

 
SUMMARY FOR WEDNESDAY, DECEMBER 12, 2018 

TEMPERATURE (DEGREES F)
MAX.....35   NORMAL.....40
MIN.....18   NORMAL.....25
MEAN....27   NORMAL.....33

DEPARTURE FROM 30-YEAR NORMAL........................-6
TOTAL DEPARTURE FOR THE MONTH.......................-43 [-3.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............38   DEPARTURE.........+5
TOTAL HEATING UNITS FOR THE MONTH.............408   DEPARTURE........+42
TOTAL HEATING UNITS FOR THE SEASON...........1728   DEPARTURE.......+101
TOTAL HEATING UNITS LAST SEASON TO DATE......1302   DIFFERENCE......+426

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................30 NW  AT 12:35 P.M.
                   AERO.........................29 NW  AT 12:42 P.M. 
                   ASOS.........................30 NW  AT 12:13 P.M. 
                   DAVIS........................31 NW  AT 12:13 P.M. RMY M
FASTEST MILE FOR YESTERDAY......................22 NW  AT  1:10 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...................21 NW  AT  2:27 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................22 NW  AT  1:54 P.M.
AVERAGE WIND SPEED AND DIRECTION..............11.5 NW
                   ASOS.......................11.9
                   DAVIS......................11.7 NNW [333 deg.]   

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE.......-0.17
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.04  DEPARTURE.......-0.94
                         ASOS..............1.78
TOTAL PRECIPITATION FOR THE YEAR..........64.41  DEPARTURE......+14.09
                         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........-4.0
TOTAL SNOWFALL FOR THE SEASON...............7.6  DEPARTURE........+1.0


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 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/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 41/28/35/-2/0.00/0.0/391/70          20 NNW AERO 18 NNW RMY N/A
12/02 52/35/44/+8/1.04/0.0/000/00          28 ESE AERO 25 ESE RMY 27
12/03 54/38/46/+10/0.00/0.0/178/32         35 W   AERO 35 W   RMY 38 
12/04 38/23/31/-4/0.00/0.0/516/93          30 WNW AERO 31 WNW RMY 33
12/05 33/18/26/-9/0.00/0.0/432/78          16 NNW AERO 15 NNW RMY N/A
12/06 37/24/31/-4/0.00/0.0/354/64          29 W   AERO 28 W   RMY 30
12/07 37/21/29/-5/0.00/0.0/.../..          29 NW  AERO 29 NW  RMY 32
12/08 27/15/21/-13/0.00/0.0/.../..         28 NW  AERO 27 NW  RMY 29
12/09 34/17/26/-8/0.00/0.0/.../..          23 SSW AERO 21 SSW RMY 22
12/10 36/22/29/-4/0.00/0.0/.../..          24 NNW AERO 23 NNW RMY 22
12/11 36/17/27/-6/0.00/0.0/.../..          16 WSW AERO 14 WSW RMY N/A
12/12 35/18/27/-6/0.00/0.0/.../..          30 NW  AERO 29 NW  RMY M

12/13 Low temp since midnight is 16F; normal low is 25F


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

RECORDS FOR DECEMBER 13
HIGH 60 IN 1984
LOW 0 IN 1893
PRECIP 1.45 INS. IN 1983
SNOWFALL 9.2 INS. IN 2007
PEAK GUST 81e WNW IN 1976

RECORDS FOR DECEMBER 14
HIGH 62 IN 1901
LOW -6 IN 1893
PRECIP 1.94 INS. IN 2002
SNOWFALL 8.0 INS. IN 1907
PEAK GUST 78e ENE IN 1941

TODAY'S REPORT PREPARED BY: Benjamin Turner