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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, JANUARY 10, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

HIGH PRESSURE BRINGS CLEAR SKIES AND LOW WINDS...

Another mild day on top of Great Blue Hill. The
day started with a clear cloudless sky. Sky cover
slightly increased throughout the day with a few 
cirrus clouds moving in by mid-morning. Winds
shifted today from the west to the south and have 
been light. Temperatures were seasonable today
with a high so far of 35F. This is 1 degree above
the daily normal of 34F.  

Today's Observations:

7 A.M.
Weather: Sky clear
Temperature: 21F; Dew Point: 14F; Wind: WSW at 4 kts,
Wind: Light 
Sea-level pressure: 30.46 ins. Hg, rising, then more slowly 
Visibility: 45 miles, distant haze in all directions
6-hr Max temp: 24F
6-hr Min temp: 21F
24-hr precip: Trace
24-hr snowfall: Trace
Snow depth: 11 ins.
BHO SA 1155 CLR 45 316/21/14/2404/046/ SKC NEW SNW PST 24 
HRS TRACE DSNT HZ ALQDS WND LGT/ 4/011 51031 10024 20021  

10 A.M.
Weather: Clear, few cirrus in all directions
Temperature: 27F; Dew Point: 15F; Wind: WSW at 4 kts,
Wind: Light
Sea-level pressure: 30.50 ins. Hg, rising unsteadily 
Visibility: 60 miles
3-hr precip: 0.00 ins.
3-hr snowfall: 0.0 ins. 
BHO SA 1455 CLR 60 329/27/15/2404/050/ FEW CI ALQDS 
DSNT HZ ALQDS WND LGT/ 53013

1 P.M.
Weather: Clear, few cirrus ESE-ENE, few cirrostratus
in all directions along horizon 
Temperature: 35F; Dew Point: 22F; Wind: SSW at 7 kts
Sea-level pressure: 30.44 ins. Hg, falling, then more slowly   
Visibility:60 miles, distant haze in all directions 
6-hr Max temp: 35F
6-hr Min temp: 20F
6-hr precip: 0.00 ins. 
6-hr snowfall: 0.0 ins.
Snow depth: 9 ins.
BHO SA 1755 CLR 60 308/35/22/2107/044/ FEW CI ESE-ENE 
FEW CS ALQDS DSNT HZ ALQDS/ 8/005 4/009 58021 10035 20020 

PRELIMINARY STATS FOR DECEMBER 2017

TEMPERATURE, Deg. F
Avg. Max. 33.9 [-5.2]
Avg. Min. 21.2 [-2.4]
Mean      27.6 [-3.7]
Corrected mean: 27.2
Max. for month: 58 on the  5TH
Min. for month: -3 on the 29TH

HEATING DEGREE DAYS
Total heating units:   1153 [+110]
Total for the season:  2122 [-183]
Total for last season: 2032

PRECIPITATION, Inches
Total: 3.08 [-1.81]

SNOWFALL, Inches
Total: 9.4 [-4.0]

WIND, mph
Avg. uncorrected wind speed: 11.6
Avg. corrected wind speed: 12.0
Prevailing wind direction: W @ 23%
Peak gust and direction: 62 S on the 5th

SUNSHINE:
Campbell-Stokes card minutes: 7128 minutes of possible 16470 or 43%
Astronomical total minutes:   7351 minutes of possible 16994 or 43%


SUMMARY FOR TUESDAY, JANUARY 9, 2018

TEMPERATURE (DEGREES F)
MAX.....40   NORMAL.....34
MIN.....25   NORMAL.....17
MEAN....33   NORMAL.....26

DEPARTURE FROM 30-YEAR NORMAL...........................+7
TOTAL DEPARTURE FOR THE MONTH.........................-109 [-12.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............32  DEPARTURE..........-7
TOTAL HEATING UNITS FOR THE MONTH............458  DEPARTURE........+109
TOTAL HEATING UNITS FOR THE SEASON..........2580  DEPARTURE.........-74
TOTAL HEATING UNITS LAST SEASON TO DATE.....2377  DIFFERENCE.......+203

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................37 W   AT 11:20 A.M.
                   AERO........................35 W   AT 11:19 A.M. 
                   ASOS........................31 WNW AT  3:40 P.M.*
                   DAVIS.......................N/A*             RMY 33 
FASTEST MILE FOR YESTERDAY.....................23 W   AT 12:11 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE..................23 W   AT  3:41 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE.................N/A*
AVERAGE WIND SPEED AND DIRECTION..............14.8 W  
                   ASOS.......................13.8*
                   DAVIS.......................N/A*

*ASOS and Davis anemometers malfunctioning
** Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE......-0.14
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.68  DEPARTURE......+0.40
                         ASOS..............1.98
TOTAL PRECIPITATION FOR THE YEAR...........1.68  DEPARTURE......+0.40
                         ASOS..............1.98

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........-0.6
TOTAL SNOWFALL FOR THE MONTH...............16.5  DEPARTURE.......+11.4
TOTAL SNOWFALL FOR THE SEASON..............25.9  DEPARTURE........+4.8

PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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

1/1 11/-5/3/-24/0.00/0.0/.../..         30 NW  AERO 30 NW  RMY 31
1/2 15/-2/7/-20/0.00/0.0/.../..         26 W   AERO 25 W   RMY 26  
1/3 28/11/20/-6/0.00/0.0/.../..         23 WSW AERO 20 WSW RMY N/A
1/4 28/18/23/-3/1.66/16.5/000/00        54 NNW AERO 60 NNW RMY 64
1/5 18/2/10/-16/0.00/0.0/.../..         53 W   AERO 53 W   RMY 57
1/6 10/-2/4/-22/0.00/0.0/.../..         43 WSW AERO 47 WSW RMY 47
1/7 14/-8/3/23/0.00/0.0/.../..          37 WNW AERO 35 WNW RMY N/A 
1/8 33/14/24/T/T/.../..                 40 S   AERO 40 S   RMY 42 
1/9 40/25/33/T/T/.../..                 37 W   AERO 35 W   RMY 33

1/10 Low temp since midnight is 21F; normal low is now 17F

DAILY RECORDS FOR JANUARY 2018

01/04/18: NEW DAILY RECORD MAXIMUM SNOWFALL OF 16.5 INS. 
          PREVIOUS RECORD WAS 8.6 INS. SET IN 1923 AND 
          TIED IN 1942 

01/07/18: DAILY RECORD LOW MINIMUM TEMPERATURE OF -8F,
          PREVIOUS RECORD OF -7F WAS SET IN 1896

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2017 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/+6/0.04/0.0/262/47        28 NW  AERO 29 NW  RMY 30
12/02 42/29/36/0/0.00/0.0/033/06         20 NNW AERO 18 NNW RMY N/A
12/03 42/32/37/+1/0.00/0.0/172/31        14 N   AERO 10 N   RMY N/A 
12/04 43/32/38/+3/0.00/0.0/522/94        16 E   AERO 14 E   RMY N/A 
12/05 58/34/46/+11/0.18/0.0/000/00       62 S   AERO 66 S   RMY 65
12/06 56/32/44/+9/0.54/0.0/160/29        52 S   AERO 55 S   RMY N/A
12/07 44/30/37/+3/0.00/0.0/540/98        25 WSW AERO 24 WSW RMY 25
12/08 38/28/33/-1/0.00/0.0/116/21        21 W   AERO 18 W   RMY 20
12/09 34/28/31/-3./0.70/5.5/000/00       23 NNW AERO 23 NNW RMY 23 
12/10 35/27/31/-2/0.02/0.1/384/70        30 W   AERO 30 W   RMY 27 
12/11 38/29/34/+1/0.00/0.0/301/55        23 W   AERO 21 W   RMY 22
12/12 43/31/37/+4/0.06/0.0/000/00        35 W   AERO 31 W   RMY N/A
12/13 31/18/25/-7/0.00/0.0/372/68        44 W   AERO 44 W   RMY 44
12/14 27/14/21/-11/T/T/257/47            35 WSW AERO 33 W   RMY 34 
12/15 24/12/18/-14/0.00/0.0/011/02       25 W   AERO 23 W   RMY N/A
12/16 32/17/25/-6/0.00/0.0/382/70        33 W   AERO 35 W   RMY 36
12/17 27/14/21/-10/0.00/0.0/425/78       21 NW  AERO 21 NW  RMY 20
12/18 35/20/28/-3/T/T/011/02             20 SSE AERO 16 SSE RMY 20
12/19 49/34/42/+12/0.00/0.0/185/34       36 WNW AERO 35 SW  RMY 38  
12/20 42/26/34/+4/T/T/447/82             41 W   AERO 40 W   RMY 45 
12/21 32/23/28/-2/0.00/0.0/533/98        26 NW  AERO 24 NW  RMY 27
12/22 32/21/27/-2/0.08/T/000/00          18 E   AERO 17 E   RMY N/A
12/23 36/24/30/+1/0.70/T/000/00          31 WSW AERO 28 WSW RMY 31
12/24 35/29/32/+3/0.00/0.0/191/35        30 ENE AERO 25 ENE RMY N/A
12/25 35/21/28/0/0.73/3.2/098/18         50 W   AERO 54 W   RMY 47
12/26 24/13/19/-9/0.00/0.0/529/97        39 W   AERO 39 W   RMY 41     
12/27 19/6/13/-15/0.00/0.0/519/95        28 WNW AERO 25 WNW RMY N/A
12/28 10/1/6/-22/0.00/0.0/546/100        37 WNW AERO 44 WNW RMY 43
12/29 13/-3/5/-22/0.00/0.0/164/30        25 W   AERO 25 W   RMY 27
12/30 14/1/8/-19/0.03/0.5/016/03         21 W   AERO 18 W   RMY 24
12/31 10/0/5/-22/0.00/0.0/175/32         32 WNW AERO 32 WNW RMY 35

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

RECORDS FOR JANUARY 10
HIGH 58F IN 2016
LOW -7F IN 2004
PRECIP 2.16 INS. IN 1935
SNOWFALL 6.3 INS. IN 1977
PEAK GUST 73e SE IN 1977

RECORDS FOR JANUARY 11
HIGH 59F IN 1975
LOW -7F IN 1968
PRECIP 1.58 INS. IN 2008
SNOW 10.2 INS. 1927
PEAK GUST 95e MPH S IN 1980

TODAY'S REPORT PREPARED BY: Kaitlin Geagan