Sunday, December 19, 2021

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

SUNDAY, DECEMBER 19, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0708E
SUNSET:  1613E

RAW AND CHILLY FOLLOWING A NIGHT OF WINTRY PRECIPITATION….

We observed a thin ice glaze at the 7 A.M. observation, accompanied
by freezing rain and a visibility of only 3 miles. New precipitation
amounts are 0.2 inches for snow and 0.91 inches for liquid. This
new rainfall was necessary, and yet we are still at a 1.25 inch
deficit on the month.

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 32F, which is 8 degrees below the normal
max of 40F. The low since midnight is 29F, which 5 degrees above
the normal low of 24F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Overcast stratus, light freezing rain with a thin
ice glaze on most surfaces
Temperature: 30F; Dew Point: 30F; Relative Humidity: 100%
Wind: N @ 10G20 kts
Sea-level pressure: 1011.1 mb; 29.86 in. Hg: rising then falling
Visibility: 3 miles, fog
6-hr Max temp: 38F
6-hr Min temp: 30F
24-hr Precip:  0.91 ins.
24-hr Snowfall: 0.2 ins.
Snow Depth: 0 ins.
BHO SA 1155 E10 OVC 3ZR-F 111/30/30/3610G20/986/ THN GLZ MST SFCS
NEW SNW PST 24 HRS 0.2 INS./ 8/6// 53037 70091 10038 20030

10 A.M.
Weather: Overcast stratocumulus
Temperature: 30F; Dew Point: 28F; Relative Humidity: 92%
Wind: N @ 8G14 kts
Sea-level pressure: 1013.1 mb; 29.92 in Hg; rising, then more
rapidly
Visibility: 35 miles, thin fog
3-hr Precip: Trace
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E40 OVC 35 131/30/28/3608G14/992/ THN F ALQDS/ 8/8//
53020 600//

1 P.M.
Weather: Overcast stratocumulus
Temperature: 30F, Dew point: 26F; Relative Humidity: 84%
Wind: NW @ 13G19 kts
Sea-level pressure: 1014.3 mb; 29.96 in Hg; rising, then more rapidly
Visibility: 70 miles
6-hr Max temp: 32F
6-hr Min temp: 29F
6-hr Precip:   Trace
6-hr Snowfall: 0.0 ins.
Snow Depth: 0.0 ins.
BHO SA 1755 E40 OVC 70 143/30/26/3313G19/996/ 8/8// 53012 600// 10032 20029

SUMMARY FOR SATURDAY, DECEMBER 18, 2021

TEMPERATURE (DEGREES F)
MAX…….39     NORMAL…..40
MIN…….31     NORMAL…..24
MEAN……35     NORMAL…..32

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………+3
TOTAL DEPARTURE FOR THE MONTH………………………+98 [+5.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY……………30  DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE MONTH…………..454  DEPARTURE…….-98
TOTAL HEATING UNITS FOR THE SEASON…………1461  DEPARTURE……-295
TOTAL HEATING UNITS LAST SEASON TO DATE…….1521  DEPARTURE…….-60

PEAK WIND GUST (MPH):
Official (1-Sec AVG)…….21 NNW @  6:30 A.M.
AEROVANE……………….20 NNW @  6:31 A.M.
VECTOR #2 (Instantaneous)..22     @  6:30 A.M.
DAVIS #2 ………………19 N   @  6:30 A.M.
RMY #2 (Instantaneous)…..20 NNW @  6:30 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………………13 ENE @  7:40 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..14     @  7:23 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………14 E   @  7:38 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..14 E   @  7:23 P.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……7.7 NE  [184 total miles] VECTOR #2…………….8.2
DAVIS #2……………..7.9 NE
RMY #2……………….8.1 NNE
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…….0.91  DEPARTURE…..+0.74
TOTAL PRECIPITATION FOR THE MONTH………….1.95  DEPARTURE…..-1.26
TOTAL PRECIPITATION FOR THE YEAR………….58.72  DEPARTURE…..+7.30

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M………….0.2  DEPARTURE……-0.2
TOTAL SNOWFALL FOR THE MONTH……………….1.4  DEPARTURE……-4.7
TOTAL SNOWFALL FOR THE SEASON (2021-2022)……2.4  DEPARTURE……-6.2

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   39/31/35/+3/…./0.2/…/..       21 NNW AERO 20 NNW RMY 20

12/19 The low since midnight is 30F, 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 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: Benjamin Turner