Saturday, December 5, 2020

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

SATURDAY, DECEMBER 5, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

GRADUALLY COOLER AS RAIN BEGINS TO MIX IN WITH
FROZEN PRECIPITATION….

We observed visibility only up to 3 miles due to fog,
and a rain that is slowly mixing with ice pellets and
snow. Wind is definitely picking up from the northeast,
and has reached 45 mph following the 1 P.M. observation.
Pressure is trending downwards very fast, dropping by
more than 12 millibars between 7 A.M. and 1 P.M.
Temperature has dropped since this morning, by more
than 7 degrees since the rain came in. Rain began to
mix with ice pellets a little before noon, and the
ice pellets have become more prevalent since then.
Current event rainfall total is around 1.30 inches,
with only a trace left of snow.

The high so far today is 43F, the same as the daily
normal high of 43F. The low since midnight is 39F,
12 degrees above the normal low of 27F.

Today’s Observations:

7 A.M.
Weather: Overcast stratus, rain
Temperature: 41F; Dew Point: 41F; Relative Humidity: 100%
Wind: NE at 9 kts
Sea-level pressure: 29.78 in Hg; falling, then more
rapidly
Visibility: 3 miles, fog
6-hr Max temp: 43F
6-hr Min temp: 41F
24-hr Precip: 0.37 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 10 OVC 3RF 086/41/41/0509/978/ RCTD/ 8/6//
70037 58018 10043 20041

10 A.M.
Weather: Overcast stratus, rain
Temperature: 40F; Dew Point: 40F; Relative Humidity: 100%
Wind: NE at 13G21 kts
Sea-level pressure: 29.67 in Hg; falling rapidly
Visibility: 1 mile, fog
3-hr Precip: 0.34 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 10 OVC 1RF 046/40/40/0113G21/967/ RCTD PRESFR/
8/6// 6034/ 56038

1 P.M.
Weather: Overcast stratus, rain and some ice pellets
Temperature: 39F; Dew Point: 39F; Relative Humidity: 100%
Wind: N at 18G32 kts, peak of 41 mph at 12:17 P.M.
Sea-level pressure: 29.42 in Hg; falling rapidly
Visibility: 2 miles, fog
6-hr Max temp: 42F
6-hr Min temp: 39F
6-hr Precip: 0.73 ins.
6-hr Snow: Trace
Snow Depth: 0 ins.
BHO SA 1755 10 OVC 2RF 963/39/39/0118G32/942/ RCTD IP-CTD
PRESFR PK WND 0136/17/ 8/6// 6073/ 56083 10042 20039

SUMMARY FOR FRIDAY, DECEMBER 4, 2020

TEMPERATURE (DEGREES F)
MAX…….58   NORMAL…..43
MIN…….40   NORMAL…..28
MEAN……49   NORMAL…..35

DEPARTURE FROM 30-YEAR NORMAL………………. +16
TOTAL DEPARTURE FOR THE MONTH………………. +35 [+8.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………16  DEPARTURE……-16
TOTAL HEATING UNITS FOR THE MONTH……………83  DEPARTURE……-33
TOTAL HEATING UNITS FOR THE SEASON…………1056  DEPARTURE…..-322
TOTAL HEATING UNITS LAST SEASON TO DATE…….1387  DEPARTURE…..-331

PEAK WIND GUST FOR YESTERDAY (MPH):
420C/Official…………..35 SSW  AT  2:47 P.M.
AEROVANE (south tower)…..35 SSW  AT  2:41 P.M.
ASOS…………………..35 SSW  AT  2:44 P.M.
DAVIS #1……………….38 N    AT  2:44 P.M.
DAVIS #2 (south tower)…..33 SSE  AT  2:27 P.M.
RMY……………………37
VECTOR…………………40
MERLIN…………………36

FASTEST MILE FOR YESTERDAY:
CONTACTING/OFFICIAL………………………..26 SSW  AT   2:32 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….25 SSW  AT   2:31 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………25 SW   AT   2:31 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 SSW  AT   2:31 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……15.7 SSW  [376 total miles] ASOS…………………15.9      [382 total miles] DAVIS #1……………..15.4 SSW  [370 total miles] DAVIS #2……………..16.3 SSW  [391 total miles] RMY………………….15.8 SSW  [380 total miles] VECTOR……………….16.3      [382 total miles]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.37  DEPARTURE….+0.21
ASOS………….0.35
TOTAL PRECIPITATION FOR THE MONTH………….0.98  DEPARTURE….+0.12
ASOS………….1.00
TOTAL PRECIPITATION FOR THE YEAR………….47.38  DEPARTURE….-1.80
ASOS………..48.33

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0  DEPARTURE…..-0.3
TOTAL SNOWFALL FOR THE MONTH……………….0.0  DEPARTURE…..-1.1
TOTAL SNOWFALL FOR THE SEASON………………6.5  DEPARTURE…..+2.8

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/+20/0.00/0.0/585/98     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/0.0/000/00         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/-1/0.01/0.0/107/03      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/…./0.0/…/..      60 S    AERO 67 W    RMY 64
12/02   42/32/37/+1/…./…/…/..       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/…./…/…/..      35 SSW  AERO 35 SSW  RMY 37

12/05 The low since midnight is 41F, the daily normal low is 27F

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

RECORDS FOR DECEMBER 5
HIGH 65 IN 2001
LOW -1 IN 1926
PRECIP 2.86 INS. IN 1993
SNOWFALL 7.0 INS. IN 1926, 1981
PEAK GUST 67 MPH WNW IN 1961, S IN 1973

RECORDS FOR DECEMBER 6
HIGH 70 IN 2001
LOW 5 IN 1901,1935
PRECIP 2.78 INS. IN 2003
SNOWFALL 17.0 INS. IN 2003
PEAK GUST 74 MPH NW IN 1981

TODAY’S REPORT PREPARED BY: Benjamin Turner