Saturday, December 17, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 17, 2016

WARM FRONT BRINGS 4 IN OF SNOW TO SUMMIT,
CHANGES TO LIGHT DRIZZLE BEFORE NOON

Snow began early this morning and measured a total of 4.3 inches
before turning to light rain by noon and then light drizzle.  Total
precipitation measured 0.58 in. at 1:00PM.  Visibility was limited to
less than 2 miles all day by fog.  Temperatures had warmed to a max.
of 33F, and winds became light and variable by the 1:00PM ob.

7 A.M.
Weather: Light snow, fog, overcast stratus
Temperature: 22F; Dew Point: 20F; Wind: ESE at 7 kts
Sea-level pressure: 30.22 ins. Hg, falling, then less quickly
Visibility: 1 1/2 miles
6-hr Max temp: 22F
6-hr Min temp: 19F
24-hr precip: 0.14 in.
2-hr snowfall: 1.7 in.
BHO SA 1155 E12 OVC 1 1/2S-F 234/22/20/1207/022/ NEW SNW PST 24 HRS
1.7 INS/ 8/6// 4/002 56044 MANUAL 70014 ASOS 70014 10022 20019

10 A.M.
Weather: Light snow, fog, overcast stratus
Temperature: 27F; Dew Point: 25F; Wind: ESE at 14 kts
Sea-level pressure: 30.07 ins. Hg, falling, then more quickly
Visibility: 1/2 mile
3-hr precip: 0.16 in.
3-hr snowfall: 1.3 in.
BHO SA 1455 E5 OVC 1/2S-F 184/27/25/1114/007/ NEW SNW PST 3 HRS 1.3 INS/
8/6// MANUAL 6016/ ASOS 60015 58050

1 P.M.
Weather: Light drizzle, thick fog
Temperature: 32; Dew Point: 31F; Wind: E at 5 kts,
Wind: Light and variable
Sea-level pressure: 29.89 ins. Hg, falling, then more quickly
Visibility: 1/8 mile
6-hr Max temp: 33F
6-hr Min temp: 22F
6-hr precip: 0.44 in.
6-hr snowfall: 2.6 in.
BHO SA 1755 W3 X 1/8L-F 121/32/31/1005/989/ WND L/V NEW SNW PST 3 HRS
1.3 INS/ 8//// 56063 MANUAL 6044/ ASOS 60043 10033 20022

SUMMARY FOR FRIDAY, DECEMBER 16, 2016

TEMPERATURE (DEGREES F)
MAX…..18   NORMAL…..39
MIN……1   NORMAL…..24
MEAN….10   NORMAL…..31

DEPARTURE FROM 30-YEAR NORMAL…………………..-21
TOTAL DEPARTURE FOR THE MONTH…………………..-34 [-2.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..55   DEPARTURE………+21
TOTAL HEATING UNITS FOR THE MONTH………….532   DEPARTURE………+33
TOTAL HEATING UNITS FOR THE SEASON………..1562   DEPARTURE……..-199
TOTAL HEATING UNITS LAST SEASON TO DATE……1318   DIFFERENCE…….+244

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….39 WNW AT 1:44 A.M.
ASOS……………………51 WNW AT 1:45 A.M.
DAVIS…………………..50 W   AT 1:45 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………36 W   AT 1:54 A.M.*
MAXIMUM 2-MINUTE ASOS AVERAGE………………33 WNW AT 1:49 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..33 W   AT 2:00 A.M.
AVERAGE WIND SPEED AND DIRECTION………….14.4 W
ASOS………………….14.1
DAVIS…………………12.8 W [260 Deg.] *last of multiple occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.14  DEPARTURE……-0.02
ASOS…………..0.14
TOTAL PRECIPITATION FOR THE MONTH……….0.98  DEPARTURE……-1.64
ASOS…………..1.07
TOTAL PRECIPITATION FOR THE YEAR……….37.95  DEPARTURE…..-13.20
ASOS………….38.50

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….1.7  DEPARTURE…….+1.2
TOTAL SNOWFALL FOR THE MONTH…………….3.4  DEPARTURE…….-2.4
TOTAL SNOWFALL FOR THE SEASON……………3.4  DEPARTURE…….-5.0

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 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 17
HIGH 63 IN 2000
LOW -10 IN 1942
PRECIP 3.03 INS. IN 1888
SNOWFALL 7.5 INS. IN 1988
PEAK GUST 78 MPH SSE IN 2000

RECORDS FOR DECEMBER 18
HIGH 59 IN 1928
LOW -11 IN 1919
PRECIP 1.44 INS. IN 1915
SNOWFALL 7.0 INS. IN 1904
PEAK GUST 76e W IN 1978

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle