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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, DECEMBER 8, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME
 
COOL, DRY, AND MOSTLY CLOUDY DAY

Cloud cover has increased, from scattered to 
broken cirrostratus, as the pressures slowly 
decreased throughout the day. We also had layers 
of altocumulus during each observation.
Winds have been coming from the southwest with
a short shift to the west have been light to
moderate. As humidity dropped from 65%-41% 
there was an increase in visibility but a 
thin smoke layer limited visibility to 70 miles.

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: Scattered cirrostratus, few altostratus NNE-SE
Temperature: 29F; Dew Point: 19F; Wind: WSW at 10 kts
Sea-level pressure: 30.02 ins. Hg, rising, then more quickly  
Visibility: 45 miles, distant haze in all directions  
6-hr Max temp: 32F
6-hr Min temp: 28F
24-hr precip: 0.00 ins.
BHO SA 1155 250 SCT 45 166/29/19/2510/002/ FEW AS NNE-SE DSNT 
HZ ALQDS/ 8/028 52020 10032 20028

10 A.M.
Weather: Broken cirrostratus, few altocumulus E-SE
Temperature: 34F; Dew Point: 20F; Wind: WSW at 6 kts,
Wind: Light
Sea-level pressure: 30.04 ins. Hg, falling then rising 
Visibility: 70 miles, smoke layer along horizon NW-NNW
3-hr precip: 0.00 ins. 
BHO SA 1455 E300 BKN 70 173/34/20/2506/004/ FEW AC SUN DMLY 
VSBL E-SE K LYR ALG HRZN NW-NNE WND LGT/ 8/036 53007  

1 P.M.
Weather: Broken altocumulus, broken cirrostratus, few 
cumulus distant W-NW 
Temperature: 37F; Dew Point: 15F; Wind: SW at 9G15 kts 
Sea-level pressure: 29.98 ins. Hg, falling, then more slowly 
Visibility: 70 miles, thin smoke layer along horizon NW-NNE  
6-hr Max temp: 37F
6-hr Min temp: 29F
6-hr precip: 0.00 ins.
BHO SA 1755 E150 BKN 280 BKN 154/37/15/2309G15/998/ 
FEW CU DSNT W-NW THN K LYR ALG HRZN NW-NNE/ 8/136 58019 
10037 20029  

SUMMARY FOR THURSDAY, DECEMBER 7, 2017
 
TEMPERATURE (DEGREES F)
MAX.....44   NORMAL.....42
MIN.....30   NORMAL.....27
MEAN....37   NORMAL.....34

DEPARTURE FROM 30-YEAR NORMAL...........................+3
TOTAL DEPARTURE FOR THE MONTH..........................+33 [+4.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............28  DEPARTURE..........-3
TOTAL HEATING UNITS FOR THE MONTH............174  DEPARTURE.........-33
TOTAL HEATING UNITS FOR THE SEASON..........1143  DEPARTURE........-326
TOTAL HEATING UNITS LAST SEASON TO DATE.....1221  DIFFERENCE........-78

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................25 WSW AT 12:57 P.M. 
                   AERO........................24 WSW AT 12:55P.M.
                   ASOS........................25 W   AT 12:57 P.M.
                   DAVIS.......................24 W   AT 12:57 P.M. RMY 25
FASTEST MILE FOR YESTERDAY.....................17 W   AT 13:05 P.M.    
MAXIMUM 2-MINUTE ASOS AVERAGE..................17 W   AT 13:04 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................18 W   AT 12:59 P.M.
AVERAGE WIND SPEED AND DIRECTION.............11.7 SW 
                   ASOS......................11.8
                   DAVIS.....................11.3 W  [261 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..........0.76  DEPARTURE......-0.39
                         ASOS..............0.83
TOTAL PRECIPITATION FOR THE YEAR..........50.60  DEPARTURE......+0.92
                         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.......-2.0
TOTAL SNOWFALL FOR THE SEASON...............0.0  DEPARTURE.......-4.6 

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/.../.../..          62 S   AERO 66 S   RMY 65
12/06 56/32/44/+9/.../.../..           52 S   AERO 55 S   RMY N/A
12/07 44/30/37/+3/0.00/.../..          25 WSW AERO 24 WSW RMY 25

12/08 Low temp since midnight is 28F; normal low is now 26F

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

RECORDS FOR DECEMBER 8
HIGH 62 IN 1966
LOW -4 IN 1906
PRECIP 1.54 INS. IN 1969
SNOWFALL 2.5 INS. IN 2001
PEAK GUST 78e W IN 1979

RECORDS FOR DECEMBER 9
HIGH 68 IN 1966
LOW -14 IN 1902
PRECIP 3.23 INS. IN 2014
SNOWFALL 10.8 INS. IN 2005
PEAK GUST 66 SE IN 1973

TODAY'S REPORT PREPARED BY: Kaitlin Geagan