Tuesday, January 5, 2021

| January 5, 2021 | Reply

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

TUESDAY, JANUARY 5, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME

ANOTHER OVERCAST DAY WITH PERIODS OF LIGHT SNOW….

A large ocean storm sitting south of Nova Scotia has been
retrograding a bit since yesterday sending spokes of moisture
onshore from off the ocean. The first spokes pushed through
last evening bringing 0.5 inches of snowfall to the summit overnight.

Periods of light snow has continued through much of today,
however it has not been able to accumulate despite the
temperature remaining below freezing. Enough solar radiation
is coming through the clouds warming the ground just enough
to melt the snow on contact.

Today is now the 5th day in a row in which at least a trace
of snow has fallen, 4 of the 5 days have had measurable
amounts totaling only 1.6 inches.

The wind has been steady, but generally light averaging around
9 mph since 7 A.M. The peak gust so far today has only been
19 mph.

The highest temperature so far today is 31F, 3 degrees below
the normal high of 34F. The low since midnight is 28F, 10
degrees above the normal minimum of 18F.

The year 2020 was 2nd warmest on record here at Blue Hill going
back to 1885. Here is a list of the rankings. Data below from
our Chief Scientist, Mike Iacono.

BHO Warmest Annual 24-Hour Adjusted Mean Temperature,
deg F (1885-2020):

1) 51.7 in 2012
2) 51.3 in 2020
3) 51.2 in 2016
4) 51.0 in 2010
5) 50.9 in 1999
6) 50.8 in 1998
7) 50.6 in 2006
8) 50.5 in 1953

Today’s Observations:

7 A.M.
Weather: Broken stratus fractus, overcast stratocumulus, few breaks
in overcast distant S-SW
Temperature: 28F; Dew Point: 27F; Relative Humidity: 96%
Wind: NNW at 7G14 kts
Sea-level pressure: 29.92 in Hg; rising, then falling
Visibility: 40 miles, 20 miles E-SE
6-hr Max temp: 30F
6-hr Min temp: 28F
24-hr Precip: 0.03 ins.
24-hr Snow: 0.5 ins.
Snow Depth: Trace.
BHO SA 1155 E9 BKN 25 OVC 40 132/28/27/3407G14/992/ FEW BINOVC DSNT S-SW HIER CLDS VSBL DSNT S-SW VSBY 20 E-SE HAZY TOTAL NEW SNW PST 24 HRS 0.5 INS/ 8/6// 4/000 50007 6002/ 70003 10030 20028

10 A.M.
Weather: Broken stratus fractus, overcast stratocumulus, light snow,
sun dimly visible
Temperature: 30F; Dew Point: 28F; Relative Humidity: 92%
Wind: N at 9G14 kts
Sea-level pressure: 29.93 in Hg; rising, then falling
Visibility: 10 miles, 6 miles ENE-SE
3-hr Precip: Trace
3-hr Snow: Trace
BHO SA 1455 E9 BKN 30 OVC 10S- 134/30/28/3509G14/993/ VSBY 6 ENE-SE SUN DMLY VSBL TOTAL NEW SNW PST 3 HRS TRACE/ 8/6// 50002 6000/

1 P.M.
Weather: Overcast stratocumulus, light snow
Temperature: 30F, Dew point: 29F; Relative Humidity: 96%
Wind: NNW at 10G16 kts
Sea-level pressure: 29.87 inches Hg, falling, then more slowly
Visibility: 3 miles, fog
6-hr Max temp: 31F
6-hr Min temp: 28F
6-hr Precip: Trace
6-hr Snow: Trace
Snow Depth: Trace
BHO SA 1755 E10 OVC 3S-F 116/30/29/3410G16/987/ TOTAL NEW SNW PST 6 HRS TRACE/ 8/5// 4/000 56018 6000/ 10031 20028

SUMMARY FOR MONDAY, JANUARY 4, 2021

TEMPERATURE (DEGREES F)
MAX…….37   NORMAL…..34
MIN…….28   NORMAL…..18
MEAN……33   NORMAL…..26

DEPARTURE FROM 30-YEAR NORMAL………………… +7
TOTAL DEPARTURE FOR THE MONTH…………………+25 [+6.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………32  DEPARTURE…… -7
TOTAL HEATING UNITS FOR THE MONTH…………..129  DEPARTURE……-25
TOTAL HEATING UNITS FOR THE SEASON…………2059  DEPARTURE…..-399
TOTAL HEATING UNITS LAST SEASON TO DATE…….2355  DEPARTURE…..-296

PEAK WIND GUST FOR YESTERDAY (MPH):
420C/Official…………..25 NNE @ 12:58 A.M.
AEROVANE (south tower)…..23 NNE @ 12:58 A.M.
ASOS…………………..26 NNE @ 12:59 A.M.
DAVIS #1……………….22 NE  @ 12:58 A.M.
DAVIS #2 (south tower)…..22 NNE @ 12:58 A.M.
RMY……………………27
VECTOR…………………25
MERLIN…………………N/A

FASTEST MILE FOR YESTERDAY:
CONTACTING/OFFICIAL………………………..13 NNE @  2:00 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….15 NNE @  1:01 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………14 NNE @  1:00 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………14 NNE @  1:00 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..15 NE  @ 12:58 A.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..14     @ 12:40 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL… 8.8 NNW [212 total miles]
ASOS……………… 9.0     [216 total miles]
DAVIS #1………….. 8.9 N   [214 total miles]
DAVIS #2………….. 9.0 N   [216 total miles]
RMY………………. 9.0 NNE [216 total miles]
VECTOR……………. 9.2     [221 total miles]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.03  DEPARTURE….-0.11
ASOS………….0.01
TOTAL PRECIPITATION FOR THE MONTH………….0.46  DEPARTURE….-0.11
ASOS………….0.45
TOTAL PRECIPITATION FOR THE YEAR…………..0.46  DEPARTURE….-0.11
ASOS…………0.45

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.5  DEPARTURE…..+0.0
TOTAL SNOWFALL FOR THE MONTH……………… 1.6  DEPARTURE…..-0.7
TOTAL SNOWFALL FOR THE SEASON……………..27.8  DEPARTURE…..+9.5

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/…/..            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/-11/0.14/1.4/…/..      38 E    AERO 37 E    RMY 39
12/17   31/19/25/-6/1.58/15.1/…/..      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/T/0.0/…/..         46 SSE  AERO 50 SSE  RMY 55
12/25   61/37/49/+21/2.15/0.0/…/..      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   49/27/38/+10/T/0.0/…/..         35 SSW  AERO 36 –    RMY 37
12/29   38/20/29/+2/0.00/0.0/…/..       48 WNW  AERO 50 WNW  RMY 56
12/30   40/19/30/+3/0.00/0.0/…/..       39 SW   AERO 41 SW   RMY 45
12/31   44/28/36/+9/0.14/0.0/…/..       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 The low since midnight is 28F, the daily normal low is 18F

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

RECORDS FOR JANUARY 5
HIGH 61F IN 2007
LOW -9F IN 1981
PRECIP 1.15 INS. IN 2019
SNOW 4.5 INS. IN 1891
PEAK GUST 70 MPH WNW IN 1959

RECORDS FOR JANUARY 6
HIGH 66F IN 2007
LOW -14F IN 1896
PRECIP 3.10 INS. IN 1889 [RECORD FOR MONTH]
SNOWFALL 7.5 INS. IN 1893
PEAK GUST 70 MPH WNW IN 1959

TODAY’S REPORT PREPARED BY: Matt Douglas

Category: Daily Discussions

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