Friday, December 11, 2020

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

FRIDAY, DECEMBER 11, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

A WARMER THAN NORMAL DAY ATOP GREAT BLUE HILL….

Today we observed mostly cloudy skies, with a max
visibility of 40 miles due to haze. Wind is
southwesterly, with a max gust of 29 mph and an
average speed of 15 mph. Pressure is on a steady
decline, which may be the reason for the increase
in clouds this afternoon.

Temperatures are definitely warmer in comparison
to the preceding days. The high so far today is
48F, 7 degrees above the daily normal high of 41F.
The low since midnight is 31F, 6 degrees above
the normal low of 25F.
PRELIMINARY STATS FOR NOVEMBER 2020

TEMPERATURE, Deg. F
Avg. Max. 56.3 [+6.3] Avg. Min. 38.6 [+5.1] Mean      47.5 [+5.8] 24-hour corrected mean: 46.9
Max. for month: 75F on the 7th
Min. for month: 18F on the 19th

HEATING DEGREE DAYS
Total heating units:   521 [-177] Total for the season:  973 [-288] Total for last season: 1237

PRECIPITATION, Inches
Total: 5.23 [+1.77] Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: TRACE
Greatest in 24 hrs: T on the 2nd

WIND, mph
Avg. uncorrected wind speed: 12.9 mph
Avg. corrected wind speed:   13.2 mph
Prevailing wind direction:   SSW [14%] Peak gust and direction:     81 SSE on the 30th

SUNSHINE:
Campbell-Stokes card minutes: 9066 minutes of a possible 17010 or 53%
Astronomical total minutes: 9382 minutes of a possible 17593 or 53%

Today’s Observations:

7 A.M.
Weather: Scattered altocumulus, broken cirrostratus
Temperature: 32F; Dew Point: 28F; Relative Humidity: 85%
Wind: SW at 8 kts
Sea-level pressure: 30.23 in Hg; rising steadily
Visibility: 40 miles, hazy
6-hr Max temp: 34F
6-hr Min temp: 31F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 1 ins.
BHO SA 1155 140 SCT 250 BKN 40 238/32/28/2308/023/ HAZY/
8/056 4/001 53008 10034 20031

10 A.M.
Weather: Scattered altocumulus, broken cirrostratus
Temperature: 42F; Dew Point: 33F; Relative Humidity: 70%
Wind: SSW at 13 kts
Sea-level pressure: 30.22 in Hg; falling steadily
Visibility: 35 miles, hazy
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 140 SCT 250 BKN 35 232/42/33/2013/022/ HAZY/
8/056 56005

1 P.M.
Weather: Scattered altocumulus, broken cirrostratus
Temperature: 48F; Dew Point: 35F; Relative Humidity: 60%
Wind: SSW at 15G22 kts
Sea-level pressure: 30.17 in Hg; falling steadily
Visibility: 30 miles, hazy
6-hr Max temp: 48F
6-hr Min temp: 32F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth:  0 ins.
BHO SA 1755 160 SCT 250 BKN 30 200/48/35/2115G22/014/ HAZY/
8/056 56032 10048 20032

SUMMARY FOR THURSDAY, DECEMBER 10, 2020

TEMPERATURE (DEGREES F)
MAX…….42   NORMAL…..41
MIN…….30   NORMAL…..26
MEAN……36   NORMAL…..33

DEPARTURE FROM 30-YEAR NORMAL……………….  +3
TOTAL DEPARTURE FOR THE MONTH………………. +12 [+1.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………29  DEPARTURE…….-3
TOTAL HEATING UNITS FOR THE MONTH…………..289  DEPARTURE……-12
TOTAL HEATING UNITS FOR THE SEASON…………1262  DEPARTURE…..-300
TOTAL HEATING UNITS LAST SEASON TO DATE…….1569  DEPARTURE…..-307

PEAK WIND GUST FOR YESTERDAY (MPH):
420C/Official…………..30 WNW  AT  9:16 A.M.
AEROVANE (south tower)…..31 WNW  AT  9:14 A.M.
ASOS…………………..29 W    AT  9:18 A.M.
DAVIS #1……………….31 W    AT  9:17 A.M.
DAVIS #2 (south tower)…..30 WNW  AT 11:12 A.M.
RMY……………………29
VECTOR…………………33
MERLIN…………………30

FASTEST MILE FOR YESTERDAY:
CONTACTING/OFFICIAL………………………..18 WNW  AT  11:12 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 NW   AT   1:36 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………20 WNW  AT  12:38 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………20 WNW  AT  11:12 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…..10.5 WNW  [251 total miles] ASOS………………..10.6      [254 total miles] DAVIS #1…………….11.3 WNW  [271 total miles] DAVIS #2…………….11.6 WNW  [278 total miles] RMY…………………10.1 WNW  [243 total miles] VECTOR………………10.8      [252 total miles]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.00  DEPARTURE….-0.17
ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….2.81  DEPARTURE….+1.16
ASOS………….2.89
TOTAL PRECIPITATION FOR THE YEAR………….47.38  DEPARTURE….-0.97
ASOS………..48.33

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0  DEPARTURE…..-0.4
TOTAL SNOWFALL FOR THE MONTH……………….2.8  DEPARTURE…..-0.4
TOTAL SNOWFALL FOR THE SEASON………………9.3  DEPARTURE…..+3.5

PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER 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

11/01   49/36/43/-3/0.69/0.0/006/01      38 W     AERO 40 W    RMY 39
11/02   40/31/36/-10/T/T/425/69          61 WNW   AERO 62 WNW  RMY 62
11/03   43/29/36/-10/0.00/0.0/473/77     48 WNW   AERO 53 WNW  RMY 48
11/04   54/30/42/-3/0.00/0.0/550/90      30 SSW   AERO 30 SSW  RMY 30
11/05   69/49/59/+14/0.00/0.0/548/90     37 SSW   AERO 40 SSW  RMY 38
11/06   72/55/64/+19/0.00/0.0/394/65     28 SW    AERO 28 SW   RMY M
11/07   75/54/65/+20/0.00/0.0/562/93     21 WSW   AERO 21 WSW  RMY 21
11/08   73/54/64/+20/0.00/0.0/584/97     18 W     AERO 18 W    RMY 19
11/09   74/52/63/+19/0.00/0.0/593/99     20 WSW   AERO 18 WSW  RMY 21
11/10   74/53/64/+20/0.00/0.0/597/100    30 SW    AERO 28 SW   RMY 31
11/11   73/58/66/+23/0.04/0.0/137/23     40 SW    AERO 44 SW   RMY 45
11/12   64/46/55/+12/0.04/0.0/000/00     32 NNW   AERO 31 NNW  RMY 33
11/13   48/38/43/0/0.30/0.0/000/00       22 NW    AERO 21 NW   RMY 25
11/14   49/32/41/-1/0.00/0.0/276/47      26 NW    AERO 28 NW   RMY 29
11/15   58/30/44/+2/0.62/0.0/311/53      60 S     AERO 67 S    RMY 65
11/16   53/39/46/+4/0.00/0.0/526/90      40 WNW   AERO 41 WNW  RMY 43
11/17   47/32/40/-1/0.00/0.0/204/35      28 NW    AERO 28 NW   RMY 30
11/18   32/19/26/-15/0.00/0.0/580/100    40 NW    AERO 46 NW   RMY 43
11/19   44/18/31/-10/0.00/0.0/393/68     37 SW    AERO 39 SW   RMY 43
11/20   63/44/54/+14/0.00/0.0/495/86     33 SSW   AERO 35 SSW  RMY 37
11/21   62/40/51/+11/0.00/0.0/339/59     24 W     AERO 23 W    RMY 27
11/22   45/33/39/-1/T/0.0/006/01         28 SE    AERO 28 SE   RMY 31
11/23   58/32/45/+6/1.77/0.0/000/00      42 WNW   AERO 48 WNW  RMY 46 TSTM
11/24   42/27/35/-4/0.00/0.0/569/100     31 WNW   AERO 32 WNW  RMY 33
11/25   50/26/38/-1/0.01/0.0/017/03      23 SSE   AERO 23 SSE  RMY 26
11/26   58/45/52/+14/0.36/0.0/000/00     36 S     AERO 37 S    RMY 41
11/27   53/46/50/+12/0.00/0.0/056/10     23 WNW   AERO 23 WNW  RMY 23
11/28   52/36/44/+6/T/0.0/180/32         28 WNW   AERO 30 WNW  RMY 27
11/29   52/33/43/+6/0.00/0.0/561/100     21 SSW   AERO 21 SSW  RMY 22
11/30   62/40/51/+14/1.35/0.0/000/00     81 SSE   AERO 82 SSE  RMY 86

DAILY RECORDS FOR NOVEMBER 2020

11/06/20: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 72F,
BREAKS PREVIOUS RECORD OF 71F SET IN 1959 AND 2015

11/07/20: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 75F,
TIES PREVIOUS RECORD OF 75F SET IN 1938

11/08/20: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 73F,
BREAKS PREVIOUS RECORD OF 72F SET IN 1938

11/09/20: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 74F,
BREAKS PREVIOUS RECORD OF 72F SET IN 1975

11/11/20: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 58F,
BREAKS PREVIOUS RECORD OF 56F IN 2002
DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 73F,
BREAKS PREVIOUS RECORD OF 68F IN 1984

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 The low since midnight is 31F, the daily normal low is 25F

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

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

RECORDS FOR DECEMBER 12
HIGH 67 IN 1979
LOW -3 IN 1988
PRECIP 3.94 INS. IN 1992
SNOWFALL 20.3 INS. IN 1960
PEAK GUST 75 MPH SSE IN 2008

TODAY’S REPORT PREPARED BY: Benjamin Turner