Thursday, December 24, 2020

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

THURSDAY, DECEMBER 24, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

INCREASING WIND AND CLOUDS AS PRESSURE
DROPS….

Today we observed a limited visibility between
1 and 40 miles. This was due to fog in the
morning and haze later on. Pressure is falling
steadily as winds begin to strengthen. There
is a constant speed of 20 mph with the highest
gusting being almost 40 mph from the southeast.

The high so far today is 53F, 16 degrees above
the daily normal maximum of 37F. The low since
midnight is 30F, 9 degrees above the normal
minimum of 21F.

Today’s Observations:

7 A.M.
Weather: Scattered altocumulus
Temperature: 38F; Dew Point: 38F; Relative Humidity: 100%
Wind: SE @ 13 kts
Sea-level pressure: 30.29 in Hg; falling steadily
Visibility: 1 mile, fog
6-hr Max temp: 39F
6-hr Min temp: 32F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 7 ins.
BHO SA 1155 180 SCT 1F 259/38/38/1513/029/ 8/070 4/007
56014 10039 20032

10 A.M.
Weather: Scattered cumulus, broken altocumulus and
cirrostratus
Temperature: 49F; Dew Point: 42F; Relative Humidity: 75%
Wind: SSE @ 15G23 kts
Sea-level pressure: 30.28 in Hg; falling steadily
Visibility: 40 miles, hazy
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 50 SCT 180 BKN 250 BKN 40 262/49/42/1615G23/028/
HAZY/ 8/878 56003

1 P.M.
Weather: Scattered stratocumulus, broken altocumulus
Temperature: 52F; Dew Point: 45F; Relative Humidity: 75%
Wind: S @ 19G30 kts, peak of 39 mph S at 12:12 P.M.
Sea-level pressure: 29.19 in Hg; falling, then more rapidly
Visibility: 25 miles, hazy
6-hr Max temp: 53F
6-hr Min temp: 38F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 5 ins.
BHO SA 1755 50 SCT 180 BKN 25 229/52/45/1719G30/019/ HAZY
PK WND 1734/12/ 8/870 4/005 56033 10053 20038

SUMMARY FOR WEDNESDAY, DECEMBER 23, 2020

TEMPERATURE (DEGREES F)
MAX…….37   NORMAL…..37
MIN…….26   NORMAL…..21
MEAN……32   NORMAL…..29

DEPARTURE FROM 30-YEAR NORMAL…………………+3
TOTAL DEPARTURE FOR THE MONTH…………………+21 [+0.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………33  DEPARTURE…….-3
TOTAL HEATING UNITS FOR THE MONTH…………..722  DEPARTURE……-23
TOTAL HEATING UNITS FOR THE SEASON…………1695  DEPARTURE…..-312
TOTAL HEATING UNITS LAST SEASON TO DATE…….2018  DEPARTURE…..-323

PEAK WIND GUST FOR YESTERDAY (MPH):
420C/Official…………..30 WNW @ 12:19 A.M.
AEROVANE (south tower)…..28 WNW @ 12:20 A.M.
ASOS…………………..29 WNW @ 12:12 A.M.
DAVIS #1……………….32 WNW @ 12:20 A.M.
DAVIS #2 (south tower)…..30 SSE @ 10:47 P.M.
RMY……………………31
VECTOR…………………34
MERLIN…………………N/A

FASTEST MILE FOR YESTERDAY:
CONTACTING/OFFICIAL………………………..20 S   @ 11:03 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….20 S   @ 11:01 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 NW  @ 12:21 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………24 SSE @  9:56 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…10.5 WNW [251 total miles] ASOS………………11.0     [264 total miles] DAVIS #1…………..11.2 W   [268 total miles] DAVIS #2…………..11.9 W   [277 total miles] RMY……………….10.4 W   [250 total miles] VECTOR…………….11.1     [258 total miles]

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………….5.03  DEPARTURE….+1.32
ASOS………….5.53
TOTAL PRECIPITATION FOR THE YEAR………….51.43  DEPARTURE….-0.81
ASOS………..52.86

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….+10.5
TOTAL SNOWFALL FOR THE SEASON……………..26.2  DEPARTURE….+14.4

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   The low since midnight is 30F, the daily normal low is 21F

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 24
HIGH 67 IN 2015
LOW -6 IN 1943
PRECIP 2.21 INS. IN 1994
SNOWFALL 12.3 INS. IN 1961
PEAK GUST 79e MPH SE IN 1941

RECORDS FOR DECEMBER 25
HIGH 64 IN 2015
LOW -11 IN 1980
PRECIP 1.37 INS. IN 2002
SNOWFALL 8.5 INS. IN 2002
PEAK GUST 80 MPH NW IN 1971

TODAY’S REPORT PREPARED BY: Benjamin Turner