Monday, December 14, 2020

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

MONDAY, DECEMBER 14, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

CLOUDY, COLD, AND WET TODAY HERE AT BLUE HILL…

What a difference a day makes! After yesterday’s mild
temperatures during which we had a high temperature
of 58 degrees, today has brought us back to the reality
that it’s mid December.

Temperatures have been stuck in the low-mid 30s all
day with light sleet, rain, and snow developing around
mid morning. The frozen precipitation types didn’t last
long, but were enough to measure 0.1″ of mainly sleet.
Light rain then continued for a few hours into early
this afternoon before a break in the action. Mixed
precipitation then re-started and has since changed to
all snow at around 3:20 this afternoon and has left
a coating so far as of the time of this discussion.

There hasn’t been much wind to speak of at all today.
We had a brief period of gusty winds between 8:45 and
9:10 this morning during which we had a peak gust of
25 MPH. But other than that, winds have generally been
less than 10 MPH most of the day. As a matter of fact,
the average speed since 7 A.M. has only been 4.6 MPH.

The high so far today is 35F, 5 degrees below the
daily normal high of 40F. The low since midnight is
31F, 7 degrees above the normal low of 24F.
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: 1.77 ins. on the 23rd

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: Broken altocumulus/altostratus, overcast cirrostratus
Temperature: 33F; Dew Point: 27F; Relative Humidity: 78%
Wind: NNW at 7 kts
Sea-level pressure: 29.95 in Hg; rising then falling
Visibility: 40 miles
6-hr Max temp: 33F
6-hr Min temp: 31F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 E140 BKN 200 OVC 40 141/33/27/3407/995/ FEW BINOVC
DSNT ENE-SE-S FEW SC OFFSHR DSNT NNE-ESE VIRGA ALQDS/ 8/577
58006 10033 20031

10 A.M.
Weather: Broken stratocumulus, overcast nimbostratus, light rain
Temperature: 34F; Dew Point: 32F; Relative Humidity: 92%
Wind: Calm
Sea-level pressure: 29.97 in Hg; rising unsteadily
Visibility: 25 miles
3-hr Precip: 0.02 ins.
3-hr Snow: 0.1 ins.
BHO SA 1455 E50 BKN 70 OVC 25R- 148/34/32/0000/997/ PCPN VRY LGT
WND CALM S-B1353E05 IP-E1357 R-B1357 TOTAL NEW SNOW/SLEET
PST 3 HRS 0.1 INS/ 8/52/ 52007 6002/

1 P.M.
Weather: Broken stratus fractus, overcast nimbostratus, light rain
Temperature: 34F; Dew Point: 34F; Relative Humidity: 100%
Wind: W at 5 kts, wind light
Sea-level pressure: 29.84 in Hg; falling, then more rapidly
Visibility: 3 miles, 6 miles NE-ESE, fog
6-hr Max temp: 35F
6-hr Min temp: 33F
6-hr Precip: 0.05 ins.
6-hr Snow: 0.1 ins.
Snow Depth:  0 ins.
BHO SA 1755 E2 BKN 25 OVC 3R-F 106/34/34/2605/984/ STFRA OCLY
DRFTG OVR SMT VSBY 6 NE-ESE IP-B25E30 WND LGT TOTAL NEW
SNOW/SLEET PST 6 HRS 0.1 INS/ 8/6// 58042 6005/ 10035 20033

SUMMARY FOR SUNDAY, DECEMBER 13, 2020

TEMPERATURE (DEGREES F)
MAX…….58   NORMAL…..40
MIN…….35   NORMAL…..25
MEAN……47   NORMAL…..32

DEPARTURE FROM 30-YEAR NORMAL………………. +15
TOTAL DEPARTURE FOR THE MONTH………………. +46 [+3.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………18  DEPARTURE……-15
TOTAL HEATING UNITS FOR THE MONTH…………..352  DEPARTURE……-46
TOTAL HEATING UNITS FOR THE SEASON…………1325  DEPARTURE…..-335
TOTAL HEATING UNITS LAST SEASON TO DATE…….1677  DEPARTURE…..-352

PEAK WIND GUST FOR YESTERDAY (MPH):
420C/Official…………..28 W    AT  7:46 P.M.
AEROVANE (south tower)…..31 WSW  AT  1:48 P.M.
ASOS…………………..29 SW   AT  1:52 P.M.
DAVIS #1……………….30 WSW  AT  1:51 P.M.
DAVIS #2 (south tower)…..30 W    AT  1:50 P.M.
RMY……………………31
VECTOR…………………31
MERLIN…………………31

FASTEST MILE FOR YESTERDAY:
CONTACTING/OFFICIAL………………………..20 WSW AT   1:53 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….20 WSW AT   1:53 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 W   AT  12:41 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………22 WSW AT   1:53 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL….10.8 WNW  [258 total miles] ASOS……………….11.5      [276 total miles] DAVIS #1……………11.3 W    [271 total miles] DAVIS #2……………11.8 W    [283 total miles] RMY………………..11.1 WNW  [266 total miles] VECTOR……………..11.8      [283 total miles]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.00  DEPARTURE….-0.16
ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….3.19  DEPARTURE….+1.05
ASOS………….3.29
TOTAL PRECIPITATION FOR THE YEAR………….49.59  DEPARTURE….-1.08
ASOS………..50.62

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…..-1.6
TOTAL SNOWFALL FOR THE SEASON………………9.3  DEPARTURE…..+2.3

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   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 The low since midnight is 31F, the daily normal low is 24F

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

RECORDS FOR DECEMBER 14
HIGH 62 IN 1901
LOW -6 IN 1893
PRECIP 1.94 INS. IN 2002
SNOWFALL 8.0 INS. IN 1907
PEAK GUST 78e ENE IN 1941

RECORDS FOR DECEMBER 15
HIGH 64 IN 1975
LOW 4 IN 1900, 1905, 1933
PRECIP 1.80 INS. IN 1981
SNOW 7.5 INS. IN 1951
PEAK GUST 65 MPH NW IN 1991

TODAY’S REPORT PREPARED BY: Matt Douglas