Saturday, December 18, 2021

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

SATURDAY, DECEMBER 18, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0708E
SUNSET:  1613E

OVERCAST WITH A WINTRY MIX BEGINNING IN THE AFTERNOON HOURS….

Today consisted of overcast skies with trace amounts of either
ice pellets, light rain, or snow beginning around noontime.
Wind was light and variable, with north being the average direction.
Visibility was 65 miles at the 10 A.M. observation, being the
highest visibility seen all day.

Some more snow would be favorable at this point, as the observatory
nears a 5-inch deficit on the month and 6 inches on the year.

The high so far today is 38F, which is 2 degrees below the normal
max of 40F. The low since midnight is 35F, which 11 degrees above
the normal low of 24F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Broken altocumulus and overcast cirrostratus
Temperature: 35F; Dew Point: 24F; Relative Humidity: 63%
Wind: N @ 8G14 kts
Sea-level pressure: 1022.4 mb; 30.19 in. Hg: rising then falling
Visibility: 40 miles
6-hr Max temp: 38F
6-hr Min temp: 35F
24-hr Precip:  0.00 ins.
24-hr Snowfall: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 110 BKN 200 OVC 40 224/35/24/3608G14/019/ 8/078 51008
10038 20035

10 A.M.
Weather: Overcast altostratus
Temperature: 36F; Dew Point: 24F; Relative Humidity: 61%
Wind: NW @ 4 kts, light and variable
Sea-level pressure: 1022.7 mb; 30.20 in Hg; falling then rising
Visibility: 65 miles
3-hr Precip: 0.00
3-hr Snowfall: 0.0 ins.
BHO SA 1455 110 OVC 65 227/36/24/3204/020/ WND L/V/ 8/07/ 50003

1 P.M.
Weather: Overcast nimbostratus, light snow beginning at 12:45 P.M. with
the end of light rain; mixed with some sleet
Temperature: 36F, Dew point: 28F; Relative Humidity: 71%
Wind: N @ 4 kts, light and variable
Sea-level pressure: 1020.2 mb; 30.12 in Hg; falling, then falling more slowly
Visibility: 5 miles, due to snow or fog
6-hr Max temp: 38F
6-hr Min temp: 35F
6-hr Precip:   Trace
6-hr Snowfall: Trace
Snow Depth: 0.0 ins.
BHO SA 1755 65 OVC 5IP-R-S-F 202/36/28/3604/012/ S-B45 R-E45 NEW SNW PST 6 HRS
TRACE WND L/V/ 8/02/ 56025 600// 10038 20035

SUMMARY FOR FRIDAY, DECEMBER 17, 2021

TEMPERATURE (DEGREES F)
MAX…….56     NORMAL…..40
MIN…….39     NORMAL…..25
MEAN……48     NORMAL…..32

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………+16
TOTAL DEPARTURE FOR THE MONTH………………………+95 [+5.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY……………17  DEPARTURE…….-16
TOTAL HEATING UNITS FOR THE MONTH…………..424  DEPARTURE…….-95
TOTAL HEATING UNITS FOR THE SEASON…………1431  DEPARTURE……-292
TOTAL HEATING UNITS LAST SEASON TO DATE…….1479  DEPARTURE…….-48

PEAK WIND GUST (MPH):
Official (1-Sec AVG)…….43 WNW @  6:14 A.M.
AEROVANE……………….41 WNW @  6:16 A.M.
VECTOR #2 (Instantaneous)..48     @  6:14 A.M.
DAVIS #2 ………………41 W   @  6:15 A.M.
RMY #2 (Instantaneous)…..46 W   @  6:15 A.M.
ASOS………..OUT OF SERVICE D/T RENOVATIONS
VECTOR #1……OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…….OUT OF SERVICE D/T RENOVATIONS
RMY #1………OUT OF SERVICE D/T RENOVATIONS
MERLIN………OUT OF SERVICE D/T RENOVATIONS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………30 WNW @  6:27 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..31     @  6:28 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………29 WNW @  6:28 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..31 WNW @  6:28 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE…….OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE..OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE RMY #1 AVERAGE…..OUT OF SERVICE D/T RENOVATIONS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……17.0 W  [408 total miles] VECTOR #2…………….17.6
DAVIS #2……………..17.7 WNW
RMY #2……………….17.4 WNW
RMY #1…………..OUT OF SERVICE D/T RENOVATIONS
ASOS…………….OUT OF SERVICE D/T RENOVATIONS
VECTOR #1………..OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…………OUT OF SERVICE D/T RENOVATIONS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.00  DEPARTURE…..-0.18
TOTAL PRECIPITATION FOR THE MONTH………….1.04  DEPARTURE…..-2.00
TOTAL PRECIPITATION FOR THE YEAR………….57.81  DEPARTURE…..+6.56

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M………….0.0  DEPARTURE……-0.4
TOTAL SNOWFALL FOR THE MONTH……………….1.2  DEPARTURE……-4.5
TOTAL SNOWFALL FOR THE SEASON (2021-2022)……2.2  DEPARTURE……-6.0

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

12/01   44/30/37/0.00/0.0/…/..          35 W   AERO 35 W   RMY 34
12/02   58/35/47/10/T/0.0/…/..          56 WNW AERO 59 WNW RMY 62 TSTM
12/03   41/28/35/-1/0.00/0.0/…/..       46 NW  AERO 44 NW  RMY 46
12/04   39/25/32/-4/0.00/0.0/…/..       25 SW  AERO 23 SW  RMY 26
12/05   45/32/39/+3/0.00/0.0/…/..       25 SE  AERO 25 SE  RMY 25
12/06   59/37/48/+13/0.34/0.0/…/..      59 WNW AERO 59 NW  RMY 60
12/07   40/29/35/0/T/0.0/…/…          47 WNW AERO 36 WNW RMY 48
12/08   34/25/30/-5/0.05/0.6/…/..       26 NNE AERO 25 NE  RMY 26
12/09   35/20/28/-6/0.05/0.6/…/..       32 NW  AERO 30 NW  RMY 33
12/10   43/27/35/+1/0.00/0.0/…/..       21 SE  AERO 20 SE  RMY 21
12/11   62/37/50/+16/0.34/0.0/…/..      57 SSW AERO 59 SSW RMY 58
12/12   58/36/47/+13/0.05/0.0/…/..      55 WNW AERO 55 WNW RMY 58
12/13   50/35/43/+10/0.00/0.0/…/..      32 WSW AERO 33 WSW RMY 33
12/14   50/33/42/+9/0.00/0.0/…/..       31 WSW AERO 30 WSW RMY 32
12/15   42/28/35/+2/T/0.0/…/..          35 SSE AERO 35 SSE RMY 36
12/16   58/42/50/+18/…/0.0/…/..       35 SW  AERO 37 SW  RMY 38
12/17   56/39/48/+16/…./…/…/..      43 WNW AERO 41 WNW RMY 46

12/18 The low since midnight is 35F, the daily normal low is 24F

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

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

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

TODAY’S REPORT PREPARED BY: Benjamin Turner