Saturday, January 9, 2021

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

SATURDAY, JANUARY 9, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME

PARTLY CLOUDY WITH A NORTHERLY BREEZE AND
GOOD VISIBILITY….

Today we observed partly cloudy skies and a visibility
of 75 miles. Wind was northerly at an average around
10 mph and a peak gust of 24 mph since 7 A.M. The ponds
are mostly frozen over, and despite abundant sunshine
they have stayed 7/10ths frozen. This is due to the
seasonable overnight lows being in the upper teens
and lower 20’s. Conditions are dry, with a current
temp of 33F and a dew point of 16F. That leaves us
with a relative humidity of 49%.

The high so far today is 34F, the same as the daily
normal maximum. The low since midnight is 20F,
3 degrees above the normal minimum of 17F.

PRELIMINARY STATS FOR DECEMBER 2020

TEMPERATURE, Deg. F
Avg. Max. 41.1 [+2.0] Avg. Min. 27.2 [+3.6] Mean      34.2 [+2.9] 24-hour corrected mean: 34.0
Max. for month: 62F on the 1st
Min. for month: 13F on the 16th and 19th

HEATING DEGREE DAYS
Total heating units:   957 [-86] Total for the season:  1930 [-375] Total for last season: 2251

PRECIPITATION, Inches
Total: 7.32 [+2.43] Greatest in 24 hrs: 2.15 ins. on the 25th

SNOWFALL, Inches
Total: 19.7 [+6.3] Greatest in 24 hrs: 16.5 ins. on the 16th-17th

WIND, mph
Avg. uncorrected wind speed: 13.0 mph
Avg. corrected wind speed:   13.3 mph
Prevailing wind direction:   WNW [17%] Peak gust and direction:     68 SSE on the 25th

SUNSHINE:
Campbell-Stokes card minutes: 6756 minutes of a possible 16470 or 41%
Astronomical total minutes: 6961 minutes of a possible 16991 or 41%

Today’s Observations:

7 A.M.
Weather: Scattered altocumulus
Temperature: 20F; Dew Point: 11F; Relative Humidity: 67%
Wind: NNW at 10 kts
Sea-level pressure: 29.83 in Hg; steady, then rising
Visibility: 60 miles
6-hr Max temp: 24F
6-hr Min temp: 20F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 70 SCT 60 100/20/11/3410/983/ 8/080 53002 10024
20020

10 A.M.
Weather: Scattered cirrocumulus
Temperature: 27F; Dew Point: 13F; Relative Humidity: 55%
Wind: N at 9G18 kts
Sea-level pressure: 29.85 in Hg; steady, then rising
Visibility: 75 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 250 SCT 75 108/27/13/3609G18/985/ 8/006 50008

1 P.M.
Weather: Scattered stratocumulus, broken altocumulus and
cirrocumulus
Temperature: 34F, Dew point: 14F; Relative Humidity: 44%
Wind: NNE at 4 kts (wind light and variable)
Sea-level pressure: 29.79 inches Hg, falling, then falling more slowly
Visibility: 75 miles
6-hr Max temp: 34F
6-hr Min temp: 20F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 30 SCT 100 BKN 250 BKN 75 090/34/14/0204/979/ WND L/V/
8/559 56018 10034 20020

SUMMARY FOR FRIDAY, JANUARY 8, 2021

TEMPERATURE (DEGREES F)
MAX…….40   NORMAL…..34
MIN…….21   NORMAL…..18
MEAN……31   NORMAL…..26

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……..+5
TOTAL DEPARTURE FOR THE MONTH……………….+49 [+5.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………34  DEPARTURE…….-5
TOTAL HEATING UNITS FOR THE MONTH…………..261  DEPARTURE……-49
TOTAL HEATING UNITS FOR THE SEASON…………2191  DEPARTURE…..-424
TOTAL HEATING UNITS LAST SEASON TO DATE…….2492  DEPARTURE…..-301

PEAK WIND GUST (MPH):
420C/Official…………..25 NNW  @  9:32 P.M.
AEROVANE (south tower)…..22 NNW  @  9:38 P.M.
ASOS…………………..23 NW   @ 12:13 A.M.
DAVIS #1……………….24 NNW  @ 12:12 A.M.
DAVIS #2 (south tower)…..22 NNW  @ 12:12 A.M.
RMY……………………25      @ 12:12 A.M.
VECTOR…………………27      @ 12:39 A.M.
MERLIN…………………N/A

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 NNW @ 12:16 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 NW  @ 12:13 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 NNW @ 12:14 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………18 NNW @ 12:13 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..18 NNW @ 12:10 A.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..18     @ 12:11 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…9.4  NW  [226 total miles] ASOS………………9.5      [230 total miles] DAVIS #1…………..9.5  NNW [230 total miles] DAVIS #2…………..10.0 NNW [235 total miles] RMY……………….9.4  NNW [226 total miles] VECTOR…………….9.5      [230 total miles]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.00  DEPARTURE….-0.14
ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….0.49  DEPARTURE….-0.65
ASOS………….0.48
TOTAL PRECIPITATION FOR THE YEAR…………..0.49  DEPARTURE….-0.65
ASOS…………0.48

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0  DEPARTURE…..-0.6
TOTAL SNOWFALL FOR THE MONTH……………… 1.9  DEPARTURE…..-2.6
TOTAL SNOWFALL FOR THE SEASON……………..28.1  DEPARTURE…..+7.6

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/+14/0.61/0.0/112/20      60 S    AERO 67 W    RMY 64
12/02   42/32/37/+1/0.00/0.0/301/54       32 SW   AERO 32 SW   RMY 35
12/03   49/30/40/+4/0.00/0.0/512/92       25 SSW  AERO 25 SSW  RMY 28
12/04   58/40/49/+14/0.06/0.0/332/60      35 SSW  AERO 35 SSW  RMY 37
12/05   42/32/37/+2/2.13/2.8/000/00       58 NNW  AERO 58 NNW  RMY 67
12/06   34/26/30/-5/0.01/T/403/73        E44 WNW  AERO 44 WNW  RMY 49
12/07   33/22/28/-6/T/T/457/83            24 NW   AERO 26 NW   RMY 26
12/08   29/22/26/-8/T/T/006/01            24 NW   AERO 25 NW   RMY 28
12/09   34/19/27/-7/T/T/000/00            16 W    AERO 17 W    RMY 19
12/10   42/30/36/+3/0.00/0.0/351/64       30 WNW  AERO 31 WNW  RMY 29
12/11   50/31/41/+8/0.00/0.0/384/70       32 SW   AERO 35 SW   RMY 34
12/12   48/40/44/+11/0.38/0.0/000/00      25 E    AERO 21 E    RMY 25
12/13   58/35/47/+15/0.00/0.0/109/20      28 W    AERO 31 WSW  RMY 31
12/14   35/30/33/+1/0.10/0.4/000/00       25 N    AERO 25 N    RMY 29
12/15   34/21/28/-4/0.00/0.0/541/99       32 WNW  AERO 33 WNW  RMY 38
12/16   27/13/20/-11/0.14/1.4/180/33      38 E    AERO 37 E    RMY 39
12/17   31/19/25/-6/1.58/15.1/000/00      55 ENE  AERO 56 ENE  RMY 59
12/18   27/18/23/-8/0.00/0.0/120/22       28 N    AERO 26 N    RMY 27
12/19   29/13/21/-9/0.00/0.0/436/80       16 SW   AERO 16 S    RMY 16
12/20   36/24/30/0/0.02/T/000/00          14 S    AERO 16 SW   RMY 14
12/21   34/29/32/+2/0.00/0.0/000/00       22 WNW  AERO 24 WNW  RMY 23
12/22   42/30/36/+7/0.00/0.0/447/82       34 WNW  AERO 35 WNW  RMY 38
12/23   37/26/32/+3/0.00/0.0/480/88       30 WNW  AERO 28 WNW  RMY 31
12/24   53/30/42/+13/T/0.0/153/28         46 SSE  AERO 50 SSE  RMY 55
12/25   61/37/49/+21/2.15/0.0/000/00      68 SSE  AERO 77 SSE  RMY 84
12/26   37/25/31/+3/0.00/0.0/485/89       38 SW   AERO 44 SW   RMY 43
12/27   38/22/30/+2/0.00/0.0/513/94       18 W    AERO 18 W    RMY 20
12/28   49/27/38/+10/T/0.0/109/20         35 SSW  AERO 36 –    RMY 37
12/29   38/20/29/+2/0.00/0.0/470/86       48 WNW  AERO 50 WNW  RMY 56
12/30   40/19/30/+3/0.00/0.0/060/11       39 SW   AERO 41 SW   RMY 45
12/31   44/28/36/+9/0.14/0.0/000/00       38 SW   AERO 43 SW   RMY 43

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
12/25/20: DAILY RECORD PRECIPITATION OF 2.15 INCHES,
BREAKS PREVIOUS RECORD OF 1.37 INCHES SET IN 2002

PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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

01/01   36/25/31/+4/0.06/0.3/…/..       23 E    AERO 23 NNW  RMY 23
01/02   43/30/37/+10/0.30/T/…/..        37 WNW  AERO 39 WNW  RMY 44
01/03   33/27/30/+4/0.07/0.8/…/..       23 NNE  AERO 22 NNE  RMY 25
01/04   37/28/33/+7/0.01/0.1/…/..       25 NNE  AERO 23 NNE  RMY 27
01/05   31/28/30/+4/0.05/0.7/…/..       21 NNW  AERO 21 NNW  RMY 22
01/06   38/28/33/+7/T/T/…/..            30 NW   AERO 29 NW   RMY 32
01/07   42/26/34/+8/0.00/0.0/…/..       28 NNW  AERO 26 NNW  RMY 31
01/08   40/21/31/+5/0.00/0.0/…/…      25 NNW  AERO 22 NNW  RMY 25

01/09 The low since midnight is 20F, the daily normal low is 17F

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

RECORDS FOR JANUARY 9
HIGH 62F IN 1937
LOW -9F IN 1968
PRECIP 3.00 INS. IN 1956
SNOWFALL 10.0 INS. IN 1904
PEAK GUST 101e MPH SE IN 1978 [RECORD FOR MONTH]

RECORDS FOR JANUARY 10
HIGH 58F IN 2016
LOW -7F IN 2004
PRECIP 2.16 INS. IN 1935
SNOWFALL 6.3 INS. IN 1977
PEAK GUST 73e SE IN 1977

TODAY’S REPORT PREPARED BY: Benjamin Turner