Saturday, December 10, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 10, 2016

COLDEST DAY OF THE SEASON DESPITE MOSTLY SUNNY SKIES

Temperatures reached a minimum of 17F this morning, making it the lowest
temperature of the season. 26F was the high reached by the 1:00PM EST observation.
Winds out of the NNW brought us this cold air. The peak gust so far for the day
is 29 mph, which was last measured at 11:32 AM EST. Pressure continued to rise and
the air remained very dry with dew points around 10F. The dry conditions allowed
for great visibility at 80 miles.

7 A.M.
Weather: Few stratocumulus NNE-SW, few altostratus SW-NNE, few cirrus in all
directions
Temperature: 18F; Dew Point: 11F; Wind: WNW at 10G18 kts
Sea-level pressure: 30.27 ins. Hg, rising, then more quickly
Visibility: 70 miles
6-hr Max temp: 20F
6-hr Min temp: 17F
24-hr precip: 0.00 in.
BHO SA 1155 CLR 70 249/18/11/2910G18/027/ FEW SC NNE-SW FEW AS SW-NNE FEW CI
ALQDS/ 8/411 53015 10020 20017

10 A.M.
Weather: Few stratocumulus in all directions, scattered cirrostratus
Temperature: 22F; Dew Point: 8F; Wind: WNW at 10G22 kts
Sea-level pressure: 30.30 ins. Hg, rising, then less quickly
Visibility: 80 miles
BHO SA 1455 250 SCT 80 261/22/08/3010G22/030/ FEW SC ALQDS/ 8/408 51012

1 P.M.
Weather: Few stratocumulus, scattered cirrostratus
Temperature: 26F; Dew Point: 10F; Wind: WNW at 11G20 kts
Sea-level pressure: 30.25 ins. Hg, falling, then more quickly
Visibility: 80 miles
6-hr Max temp: 26F
6-hr Min temp: 18F
BHO SA 1755 220 SCT 80 245/26/10/3011G20/025/ FEW SC ALQDS/ 8/408 56016 10026
20018

SUMMARY FOR FRIDAY, DECEMBER 9, 2016

TEMPERATURE (DEGREES F)
MAX…..35   NORMAL…..41
MIN…..21   NORMAL…..26
MEAN….28   NORMAL…..34

DEPARTURE FROM 30-YEAR NORMAL……………………-6
TOTAL DEPARTURE FOR THE MONTH…………………..+11 [+0.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..37   DEPARTURE……….-6
TOTAL HEATING UNITS FOR THE MONTH………….258   DEPARTURE………-11
TOTAL HEATING UNITS FOR THE SEASON………..1288   DEPARTURE……..-243
TOTAL HEATING UNITS LAST SEASON TO DATE……1209   DIFFERENCE……..+79

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….35 W   AT  9:06 A.M.
ASOS……………………36 W   AT  9:06 A.M.
DAVIS…………………..34 W   AT  9:04 A.M. RMY 34
FASTEST MILE FOR YESTERDAY…………………24 W   AT  1:00 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………34 WNW AT  1:51 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..23 W   AT 12:46 P.M.
AVERAGE WIND SPEED AND DIRECTION………….16.1 W
ASOS………………….15.0
DAVIS…………………13.9 W [270 Deg.]

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……….0.43  DEPARTURE……-1.05
ASOS…………..0.49
TOTAL PRECIPITATION FOR THE YEAR……….37.40  DEPARTURE…..-12.61
ASOS………….37.92

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.4
TOTAL SNOWFALL FOR THE MONTH…………….0.4  DEPARTURE…….-2.4
TOTAL SNOWFALL FOR THE SEASON……………0.4  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/…/..           37 WNW AERO 39 WNW RMY 40
12/4  39/27/33/-2/0.00/0.0/…/..           25 NW  AERO 25 NW  RMY N/A
12/5  36/27/32/-3/0.13/0.4/…/..           26 W   AERO 25 W   RMY 29
12/6  42/30/36/+1/0.00/0.0/…/..           22 W   AERO 21 W   RMY N/A
12/7  39/34/37/+3/0.10/0.0/…/..           21 E   AERO 21 E   RMY N/A
12/8  40/29/35/+1/0.00/0.0/…/..           30 W   AERO 31 W   RMY 33
12/9  35/21/28/-6/0.00/0.0/…/..           35 W   AERO 36 WNW RMY 34

12/10  Low temp since midnight is 17F; 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 10
HIGH 62 IN 1946
LOW -6 IN 1902
PRECIP 1.67 INS. IN 1907
SNOWFALL 6.0 INS. IN 1905
PEAK GUST 66e SW IN 1940

RECORDS FOR DECEMBER 11
HIGH 63 IN 1911
LOW -1 IN 1988
PRECIP 2.36 INS. IN 1992
SNOWFALL 6.0 INS. IN 1894
PEAK GUST 78 S IN 1969

TODAY’S REPORT PREPARED BY: Lizzy Suzedell