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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, DECEMBER 21, 2016  

FIRST DAY OF WINTER MET WITH DRY CONDITIONS AND MILD TEMPS.

Temperatures rose to a max of 40F by 1:00PM today after a
morning low of 25F, creating warmer than normal conditions
for our first day of winter.  Dew points in the upper teens
gave us dry conditions.  The day was made even better by
mostly sunny skies hindered only by scattered cirrus.

Winds picked up slightly in the early afternoon and were
gusting to 18 MPH out of the west.  Distant haze limited
prevailing visibility to 20 miles in the morning, improving
to 35-60 miles in the early afternoon.


7 A.M.
Weather: Few altocumulus ESE-SW, scattered cirrus
Temperature: 25F; Dew Point: 15F; Wind: WSW at 8 kts
Sea-level pressure: 30.08 ins. Hg, steady, then rising
Visibility: 20 miles, distant haze in all directions
6-hr Max temp: 30F
6-hr Min temp: 25F
24-hr precip: 0.00 in.
BHO SA 1155 250 SCT 20 186/25/15/2408/008/ FEW AC ESE-SW DSNT HZ 
ALQDS/ 8/031 53008 10030 20025

10 A.M.
Weather: Scattered cirrus
Temperature: 30F; Dew Point: 13F; Wind: WSW at 8 kts
Sea-level pressure: 30.11 ins. Hg, rising then steady
Visibility: 20 miles, distant haze in all directions
BHO SA 1455 250 SCT 20 195/30/13/2408/011/ DSNT HZ ALQDS/ 8/001 
51009

1 P.M.
Weather: Scattered cirrus
Temperature: 40F; Dew Point: 18F; Wind: W at 9G16 kts
Sea-level pressure: 30.06 ins. Hg, falling, then more slowly
Visibility: 35 miles, except 60 miles WSW-NNW, distant haze
in all directions
6-hr Max temp: 40F
6-hr Min temp: 25F
BHO SA 1755 250 SCT 35 181/40/18/2709G16/006/ VSBY WSW-NNW 60
DSNT HZ ALQDS/ 8/001 56014 10040 20025


SUMMARY FOR TUESDAY, DECEMBER 20, 2016
 
TEMPERATURE (DEGREES F)
MAX.....32   NORMAL.....38
MIN.....13   NORMAL.....22
MEAN....23   NORMAL.....30

DEPARTURE FROM 30-YEAR NORMAL........................-7
TOTAL DEPARTURE FOR THE MONTH.......................-39 [-2.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............42   DEPARTURE..........+7
TOTAL HEATING UNITS FOR THE MONTH.............675   DEPARTURE.........+37
TOTAL HEATING UNITS FOR THE SEASON...........1705   DEPARTURE........-195
TOTAL HEATING UNITS LAST SEASON TO DATE......1422   DIFFERENCE.......+283

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................28 SSE AT 10:29 P.M.
                   ASOS........................29 SSW AT 10:31 P.M.
                   DAVIS.......................28 SSE AT 10:30 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY.....................21 SSW AT 10:51 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................22 SSW AT 11:29 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE.................21 S   AT 11:29 P.M.
AVERAGE WIND SPEED AND DIRECTION..............9.7 W
                   ASOS.......................9.8
                   DAVIS......................9.1 S [190 Deg.]
*last of multiple occurances


PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE......-0.16
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.49  DEPARTURE......-1.75
                         ASOS..............1.64
TOTAL PRECIPITATION FOR THE YEAR..........38.46  DEPARTURE.....-13.31
                         ASOS.............39.07

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.......-0.6
TOTAL SNOWFALL FOR THE MONTH................6.0  DEPARTURE.......-1.8
TOTAL SNOWFALL FOR THE SEASON...............6.0  DEPARTURE.......-4.4


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/-4/0.60/4.3/.../..           25 SSW AERO 28 SSW RMY N/A
12/18 55/30/43/+12/0.05/0.0/.../..          47 WSW AERO 53 S   RMY 53
12/19 30/17/24/-6/0.00/0.0/.../..           26 WNW*AERO 28 NW  RMY 26
12/20 32/13/23/-7/0.00/0.0/.../..           28 SSE AERO 29 SSW RMY N/A

12/21 Low temp since midnight is 25F; normal low is now 22F


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

RECORDS FOR DECEMBER 21
HIGH 60 IN 1957
LOW -10 IN 1942
PRECIP 2.01 INS. IN 1946
SNOWFALL 11.4 INS. IN 1954
PEAK GUST 77 MPH SSE IN 1957

RECORDS FOR DECEMBER 22
HIGH 62 IN 1994
LOW -5 IN 1921
PRECIP 1.52 INS. IN 1975
SNOWFALL 8.8 INS. IN 1975
PEAK GUST 62 MPH WNW IN 1998

TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle