Monday, December 28, 2020

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

MONDAY, DECEMBER 28, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

OVERCAST AND MAINLY DRY ATOP GREAT BLUE HILL…

Not much to write home about today. Chilly overcast skies
with limited visibility have been the theme here today. The
only precipitation so far is a trace as we caught the
remnants of a dissolving band of light rain.

Winds shifted yesterday evening from the west-southwest to
now primarily out of the south-southeast. This direction
has allowed temperatures to reach the mid-40s, despite
the abundant cloud cover. Gusts have not been too impressive
– peaking at 29 MPH so far today.

The high so far today is 44F, 8 degrees above the daily
normal high of 36. The low since midnight is 27F, 7 degrees
above the daily normal low of 20F.

Today’s Observations:

7 A.M.
Weather: Overcast Stratocumulus
Temperature: 32F; Dew Point: 28F; Relative Humidity: 84%
Wind: S @ 11 kts
Sea-level pressure: 30.28 in Hg; falling, then rising
Visibility: 35 miles (hazy)
6-hr Max temp: 32F
6-hr Min temp: 27F
24-hr Precip: 0.0 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 E035 OVC 35 255/32/28/1811/028/ DSNT HZ ALQDS/ 8/5// 55010 10032 20027

10 A.M.
Weather: Broken Stratocumulus, Overcast Altostratus
Temperature: 40F; Dew Point: 37F; Relative Humidity: 88%
Wind: SSE @ 14G23 kts,
Sea-level pressure: 30.22 in Hg; falling, then falling more slowly
Visibility: 35 miles (hazy)
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 E040 BKN E180 OVC 35 234/40/37/1614G23/022/ HAZY/ 8/51/ 56021

1 P.M.
Weather: Scattered Stratocumulus, Broken Altostratus/Altocumulus
Temperature: 44F, Dew point: 39F; Relative Humidity: 82%
Wind: S @ 15G20 kts,
Sea-level pressure: 30.11 inches Hg, falling, then falling more rapidly
Visibility: 35 miles (hazy)
6-hr Max temp: 44F
6-hr Min temp: 32F
Snow Depth: 0 ins.
BHO SA 1755 E035 SCT E200 BKN 35 196/44/39/1815G20/011/ HAZY/ 8/51/ 58038 10044 20032

SUMMARY FOR SUNDAY, DECEMBER 27, 2020

TEMPERATURE (DEGREES F)
MAX…….38   NORMAL…..36
MIN…….22   NORMAL…..20
MEAN……30   NORMAL…..28

DEPARTURE FROM 30-YEAR NORMAL………………….+2
TOTAL DEPARTURE FOR THE MONTH…………………+60 [+2.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………35  DEPARTURE…….-2
TOTAL HEATING UNITS FOR THE MONTH…………..830  DEPARTURE……-62
TOTAL HEATING UNITS FOR THE SEASON…………1803  DEPARTURE…..-351
TOTAL HEATING UNITS LAST SEASON TO DATE…….2135  DEPARTURE…..-332

PEAK WIND GUST FOR YESTERDAY (MPH):
420C/Official…………..18 W   @ 12:04 A.M.
AEROVANE (south tower)…..18 W   @ 12:40 A.M.
ASOS…………………..20 W   @ 12:04 A.M.
DAVIS #1……………….17 WSW @  6:52 A.M.
DAVIS #2 (south tower)…..18 S   @ 10:17 P.M.
RMY……………………20
VECTOR…………………21
MERLIN…………………N/A

FASTEST MILE FOR YESTERDAY:
CONTACTING/OFFICIAL………………………..13 S   @ 10:22 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….15 S   @ 10:18 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………13 SSW @ 10:18 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………14 S   @ 10:18 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…8.4 WSW [201 total miles] ASOS………………9.2     [221 total miles] DAVIS #1…………..8.9 WSW [214 total miles] DAVIS #2…………..9.4 SW  [226 total miles] RMY……………….8.9 SSW [214 total miles] VECTOR…………….9.2     [221 total miles]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.00  DEPARTURE….-0.15
ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….7.18  DEPARTURE….+2.86
ASOS………….7.77
TOTAL PRECIPITATION FOR THE YEAR………….53.58  DEPARTURE….+0.73
ASOS………..55.10

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0  DEPARTURE…..-0.5
TOTAL SNOWFALL FOR THE MONTH………………19.7  DEPARTURE…..+8.5
TOTAL SNOWFALL FOR THE SEASON……………..26.2  DEPARTURE….+12.4

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

12/01   62/40/51/+14/0.61/0.0/…/..      60 S    AERO 67 W    RMY 64
12/02   42/32/37/+1/0.00/0.0/…/..       32 SW   AERO 32 SW   RMY 35
12/03   49/30/40/+4/0.00/0.0/…/..       25 SSW  AERO 25 SSW  RMY 28
12/04   58/40/49/+14/0.06/0.0/…/..      35 SSW  AERO 35 SSW  RMY 37
12/05   42/32/37/+2/2.13/2.8/…/..       58 NNW  AERO 58 NNW  RMY 67
12/06   34/26/30/-5/0.01/T/…/..        E44 WNW  AERO 44 WNW  RMY 49
12/07   33/22/28/-6/T/T/…/..            24 NW   AERO 26 NW   RMY 26
12/08   29/22/26/-8/T/T/…/..            24 NW   AERO 25 NW   RMY 28
12/09   34/19/27/-7/T/T/…/..            16 W    AERO 17 W    RMY 19
12/10   42/30/36/+3/0.00/0.0/…/..       30 WNW  AERO 31 WNW  RMY 29
12/11   50/31/41/+8/0.00/0.0/…/..       32 SW   AERO 35 SW   RMY 34
12/12   48/40/44/+11/0.38/0.0/…/..      25 E    AERO 21 E    RMY 25
12/13   58/35/47/+15/0.00/0.0…/..       28 W    AERO 31 WSW  RMY 31
12/14   35/30/33/+1/0.10/0.4/…/..       25 N    AERO 25 N    RMY 29
12/15   34/21/28/-4/0.00/0.0/…/..       32 WNW  AERO 33 WNW  RMY 38
12/16   27/13/20/-11/…./1.4/…/..      38 E    AERO 37 E    RMY 39
12/17   31/19/25/-6/…./15.1/…/..      55 ENE  AERO 56 ENE  RMY 59
12/18   27/18/23/-8/0.00/0.0/…/..       28 N    AERO 26 N    RMY 27
12/19   29/13/21/-9/0.00/0.0/…/..       16 SW   AERO 16 S    RMY 16
12/20   36/24/30/0/0.02/T/…/..          14 S    AERO 16 SW   RMY 14
12/21   34/29/32/+2/0.00/0.0/…/..       22 WNW  AERO 24 WNW  RMY 23
12/22   42/30/36/+7/0.00/0.0/…/…      34 WNW  AERO 35 WNW  RMY 38
12/23   37/26/32/+3/0.00/0.0/…/..       30 WNW  AERO 28 WNW  RMY 31
12/24   53/30/42/+13/…./…/…/..      46 SSE  AERO 50 SSE  RMY 55
12/25   61/37/49/+21/…./…/…/..      68 SSE  AERO 77 SSE  RMY 84
12/26   37/25/31/+3/0.00/0.0/…/..       38 SW   AERO 44 SW   RMY 43
12/27   38/22/30/+2/0.00/0.0/../..        18 W    AERO 18 W    RMY 20

12/28 The low since midnight is 27F, the daily normal low is 20F

DAILY RECORDS FOR DECEMBER 2020

12/17/20: DAILY RECORD SNOWFALL OF 15.1 INCHES,

BREAKS PREVIOUS RECORD OF 7.5 INCHES SET IN 1988

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

RECORDS FOR DECEMBER 28
HIGH 60 IN 1982
LOW -2 IN 1933
PRECIP 2.16 INS. IN 1967
SNOWFALL 9.5 INS. IN 1967
PEAK GUST 89 MPH SSE IN 1983

RECORDS FOR DECEMBER 29
HIGH 72 IN 1984
LOW -19 IN 1933 (RECORD FOR DECEMBER)
PRECIP 1.91 INS. IN 1945
SNOWFALL 18.4 INS. IN 1945
PEAK GUST 95 MPH S IN 1966 (RECORD FOR DECEMBER)

TODAY’S REPORT PREPARED BY: Andrew Swanson