Saturday, January 9, 2021

| January 9, 2021 | Reply

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

Category: Daily Discussions

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