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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 19, 2016  

CHILLY TEMPERATURES RETURN AS WINDS BECOME LIGHT

Below average temperatures have returned today despite high
pressure bringing sunny skies and dry conditions.  Temps.
reached a minimum of 17F after the 10:00am observation and
then rose to 24F by 1:00PM.  Visibility improved to 70 miles
mid-morning, while winds became light by early afternoon.


7 A.M.
Weather: Overcast altostratus
Temperature: 20F; Dew Point: 9F; Wind: NW at 11G18 kts
Sea-level pressure: 30.62 ins. Hg, rising, then more slowly
Visibility: 40 miles
6-hr Max temp: 28F
6-hr Min temp: 19F
24-hr precip: Trace
BHO SA 1155 E200 OVC 40 368/20/09/3111G18/062/ 8/02/ 51033
ASOS 70005 10028 20019

10 A.M.
Weather: Scattered altostratus
Temperature: 18F; Dew Point: 1F; Wind: NNW at 10G16 kts
Sea-level pressure: 30.71 ins. Hg, rising, then more slowly
Visibility: 70 miles
BHO SA 1455 200 SCT 70 401/18/01/3310G16/071/ 8/010 51033

1 P.M.
Weather: Broken cirrus
Temperature: 24F; Dew Point: 0F; Wind: NNW at 4 kts,
Wind Speed: Light
Sea-level pressure: 30.67 ins. Hg, falling, then more quickly
Visibility: 70 miles
6-hr Max temp: 24F
6-hr Min temp: 17F
BHO SA 1755 E250 BKN 70 386/24/00/3404/067/ WND LGT/ 
8/002 56015 10024 20017


SUMMARY FOR SUNDAY, DECEMBER 18, 2016
 
TEMPERATURE (DEGREES F)
MAX.....55   NORMAL.....38
MIN.....30   NORMAL.....23
MEAN....43   NORMAL.....31

DEPARTURE FROM 30-YEAR NORMAL.......................+12
TOTAL DEPARTURE FOR THE MONTH.......................-26 [-1.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............22   DEPARTURE.........-13
TOTAL HEATING UNITS FOR THE MONTH.............592   DEPARTURE.........+24
TOTAL HEATING UNITS FOR THE SEASON...........1622   DEPARTURE........-208
TOTAL HEATING UNITS LAST SEASON TO DATE......1360   DIFFERENCE.......+262

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................47 WSW AT 3:26 P.M.
                   ASOS........................52 SSW AT 7:55 A.M.
                   DAVIS.......................52 SSE AT 7:54 A.M. RMY 53
FASTEST MILE FOR YESTERDAY.....................36 SSE AT 7:33 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................37 SSW AT 8:01 A.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE.................35 SSE AT 8:01 A.M.
AVERAGE WIND SPEED AND DIRECTION.............23.4 SSE
                   ASOS......................21.8
                   DAVIS.....................20.9 S [190 Deg.]
*last of multiple occurances


PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace  DEPARTURE......-0.16
                         ASOS..............0.05
TOTAL PRECIPITATION FOR THE MONTH..........1.49  DEPARTURE......-1.44
                         ASOS..............1.64
TOTAL PRECIPITATION FOR THE YEAR..........38.46  DEPARTURE.....-13.00
                         ASOS.............39.07

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.......-0.4
TOTAL SNOWFALL FOR THE MONTH................6.0  DEPARTURE.......-0.7
TOTAL SNOWFALL FOR THE SEASON...............6.0  DEPARTURE.......-3.3


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

12/1  55/39/47/+10/0.20/0.0/385/69          36 W   AERO 37 W   RMY 36
12/2  48/34/41/+5/0.00/0.0/535/96           32 W   AERO 32 W   RMY N/A
13/3  44/31/38/+2/0.00/0.0/445/80           37 WNW AERO 39 WNW RMY 40
12/4  39/27/33/-2/0.00/0.0/355/64           25 NW  AERO 25 NW  RMY N/A
12/5  36/27/32/-3/0.13/0.4/000/00           26 W   AERO 25 W   RMY 29
12/6  42/30/36/+1/0.00/0.0/392/71           22 W   AERO 21 W   RMY N/A
12/7  39/34/37/+3/0.10/0.0/000/00           21 E   AERO 21 E   RMY N/A
12/8  40/29/35/+1/0.00/0.0/033/06           30 W   AERO 31 W   RMY 33
12/9  35/21/28/-6/0.00/0.0/549/100          35 W   AERO 36 WNW RMY 34
12/10 27/17/22/-11/0.00/0.0/544/99          26 WNW AERO 27 WNW RMY 29 
12/11 33/16/25/-8/0.06/0.4/411/75           17 SSW AERO 15 SW  RMY N/A
12/12 41/27/34/+1/0.35/0.9/038/07           29 ESE AERO 29 SE  RMY 30
12/13 41/30/36/+4/0.00/0.0/.../..           25 WSW AERO 25 W   RMY 27
12/14 40/26/33/+1/0.00/0.0/.../..           30 WNW AERO 31 WNW RMY N/A
12/15 29/13/21/-11/T/T/.../..               50 W   AERO 62 W   RMY 56
12/16 18/01/10/-21/0.00/0.0/.../..          39 WNW AERO 51 WNW RMY N/A
12/17 36/18/27/-4/..../4.3/.../..           25 SSW AERO 28 SSW RMY N/A
12/18 55/30/43/+12/..../0.0/.../..          47 WSW AERO 53 S   RMY 53

12/19 Low temp since midnight is 18F; normal low is now 23F


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

RECORDS FOR DECEMBER 19
HIGH 59 IN 1899
LOW -1 IN 1919
PRECIP 2.06 INS. IN 1986
SNOWFALL 14.1 INS. IN 1945
PEAK GUST 68 NE IN 1986

RECORDS FOR DECEMBER 20
HIGH 61 IN 1957
LOW -16 IN 1942
PRECIP 1.69 INS. IN 1936
SNOWFALL 13.7 INS. IN 2009
PEAK GUST 75 MPH S IN 2002

TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle