Friday, November 20, 2020

| November 20, 2020 | Reply

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

FRIDAY, NOVEMBER 20, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

COLD YESTERDAY, BUT TEMPERATURE PENDULUM SWINGS WARM
TODAY…

An anomalously cold air mass that overtook the area mid-week
peaked yesterday morning. It presented the coldest low temperature
of the season of 18 degrees! But it was not sustained and it soon
loosened its grip. Since bottoming out, a busy SW wind peaking at
37 MPH at 11:54 PM last night has ushered in warming temperatures.
In fact, it warmed throughout the nocturnal hours with yesterday’s
high occurring at midnight at 44 degrees. So far today, the high has
achieved 62 degrees.

Very dry air has ruled today with a spacious dew point depression
of 30 degrees! Despite this, visibly has been fairly meager
averaging about 45 miles today.

The high so far today is 62F, 13 degrees above the daily
normal high of 49F. The low since midnight 44F, 12 degrees
above the normal low of 32F.

PRELIMINARY STATS FOR OCTOBER 2020

TEMPERATURE, Deg. F
Avg. Max. 61.2 [+0.9]
Avg. Min. 45.5 [+2.6]
Mean      53.4 [+1.8]
24-hour corrected mean: 52.7
Max. for month: 75F on the 1st and 10th
Min. for month: 24F on the 31st

HEATING DEGREE DAYS
Total heating units:   354  [-67]
Total for the season:  452 [-111]
Total for last season: 440

COOLING DEGREE DAYS
Total cooling units:      1  [-4]
Total for the season:   831  [+229]
Total for last season:  682

PRECIPITATION, Inches
Total: 6.75 [+2.06]
Greatest in 24 hrs: 2.24 inches on the 16-17th

SNOWFALL, Inches
Total: 6.5 [+6.2]
Greatest in 24 hrs: 6.5 inches on the 30th

WIND, mph
Avg. uncorrected wind speed: 10.7 mph
Avg. corrected wind speed:   11.3 mph
Prevailing wind direction:   S [12%]
Peak gust and direction:     76 S on the 7th

SUNSHINE:
Campbell-Stokes card minutes: 10008 minutes of a possible 19824 or 50%
Astronomical total minutes: 10345 minutes of a possible 20500 or 50%

Today’s Observations:

7 A.M.
Weather: Broken Altocumulus & Altostratus, (thin) Broken Cirrus
and Cirrostratus
Temperature: 45F; Dew Point: 33F; Relative Humidity: 62%
Wind: SSW at 17 kts, gusting to 24 kts
Sea-level pressure: 30.30 ins. Hg, rising, then falling
Visibility: 35 miles, hazy
6-hr Max temp: 46F
6-hr Min temp: 44F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 E140 BKN E250 -BKN 35 260/45/33/2117G24/030/ HAZY/
8/096 50002 10046 20044

10 A.M.
Weather: Scattered Altocumulus & Altostratus, (thin) Broken Cirrus
Temperature: 53F; Dew Point: 33F; Relative Humidity: 46%
Wind: SSW at 16 kts, gusting to 22 kts
Sea-level pressure: 30.29 ins. Hg: rising, then falling
Visibility: 45 miles, hazy
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 130 SCT E250 -BKN 45 258/53/33/211622/029/ HAZY/ 8/096 58002

1 P.M.
Weather: Scattered Altocumulus & Altostratus, (thin) Scattered
Cirrus and Cirrocumulus
Temperature: 62F; Dew Point: 32F; Relative Humidity: 32%
Wind: SSW at 16 kts, gusting to 20 kts
Sea-level pressure: 30.23 ins. Hg: falling, then falling more rapidly
Visibility: 50 miles, hazy
6-hr Max temp: 62F
6-hr Min temp: 45F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 130 SCT 250 -SCT 50 236/62/32/2116G20/023/ HAZY/ 8/096 58022
10062 20045

SUMMARY FOR THURSDAY, NOVEMBER 19, 2020

TEMPERATURE (DEGREES F)
MAX…….44   NORMAL…..49
MIN…….18   NORMAL…..33
MEAN……31   NORMAL…..41

DEPARTURE FROM 30-YEAR NORMAL………………. -10
TOTAL DEPARTURE FOR THE MONTH……………….+100 [+5.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………34  DEPARTURE……+10
TOTAL HEATING UNITS FOR THE MONTH…………..308  DEPARTURE……-99
TOTAL HEATING UNITS FOR THE SEASON………….760  DEPARTURE…..-210
TOTAL HEATING UNITS LAST SEASON TO DATE……..952  DEPARTURE…..-192

PEAK WIND GUST FOR YESTERDAY (MPH):
420C/Official…………..37 SW   AT  11:54 P.M.
AEROVANE (south tower)…..39 SW   AT  11:36 P.M.
ASOS…………………..40 SW   AT  11:56 P.M.
DAVIS #1……………….38 SW   AT  11:34 P.M.
DAVIS #2 (south tower)…..38 SSW  AT  11:34 P.M.
RMY……………………43
VECTOR…………………43
MERLIN…………………40

FASTEST MILE FOR YESTERDAY:
CONTACTING/OFFICIAL………………………..29 SW   AT  11:19 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….29 SW   AT  11:19 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………28 SW   AT  11:19 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………29 SW   AT  11:19 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……13.6 SSW [327 total miles]
ASOS…………………13.8     [331 total miles]
DAVIS #1……………..13.2 SW  [317 total miles]
DAVIS #2……………..13.8 SW  [331 total miles]
RMY………………….13.5 SW  [324 total miles]
VECTOR……………….13.9     [334 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………….1.74  DEPARTURE….-1.25
ASOS………….1.78
TOTAL PRECIPITATION FOR THE YEAR………….42.91  DEPARTURE….-3.85
ASOS………..43.73

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0  DEPARTURE…..-0.1
TOTAL SNOWFALL FOR THE MONTH……………..Trace  DEPARTURE…..-0.8
TOTAL SNOWFALL FOR THE SEASON………………6.5  DEPARTURE…..+5.4

PRELIMINARY CLIMATE SUMMARY FOR OCTOBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

10/01  75/56/66/+9/0.00/591/84           28 SW    AERO 28 SW   RMY N/A
10/02  63/49/56/-1/0.02/203/29           20 NW    AERO 21 NW   RMY 20
10/03  65/45/55/-1/0.00/676/97           19 WNW   AERO 19 WNW  RMY 19
10/04  65/45/55/-1/0.00/659/95           17 ESE   AERO 18 ESE  RMY 18
10/05  62/52/57/+1/0.00/277/40           17 ENE   AERO 17 ENE  RMY N/A
10/06  69/51/60/+5/0.00/503/73           28 S     AERO 28 S    RMY 29
10/07  73/50/62/+7/0.14/316/46           76 W     AERO 74 W    RMY 70  TSTM
10/08  61/42/52/-2/0.00/676/99           41 W     AERO 41 W    RMY N/A
10/09  60/37/49/-5/0.00/646/95           25 SSW   AERO 28 SSW  RMY N/A
10/10  75/52/64/+10/0.00/549/81          40 SSW   AERO 40 SSW  RMY 38
10/11  64/47/56/+3/0.00/574/85           32 NNW   AERO 35 NNW  RMY N/A
10/12  52/48/50/-3/T/000/00              28 E     AERO 27 E    RMY N/A
10/13  57/49/53/0/1.74/000/00            32 E     AERO 33 E    RMY N/A
10/14  67/47/57/+5/0.00/606/91           23 WNW   AERO 25 WNW  RMY N/A
10/15  71/50/61/+9/0.00/511/77           43 S     AERO 46 S    RMY 42
10/16  68/48/58/+7/1.00/020/03           28 S     AERO 30 S    RMY N/A
10/17  56/39/48/-3/1.24/480/73           35 WNW   AERO 40 WNW  RMY 37
10/18  60/46/53/+2/0.00/622/95           20 ESE   AERO 21 ESE  RMY 20
10/19  61/46/54/+4/0.00/575/88           16 ESE   AERO 16 SSE  RMY N/A
10/20  66/49/58/+8/0.00/065/10           22 S     AERO 22 S    RMY 22
10/21  71/56/64/+14/0.06/000/00          26 SSW   AERO 26 SSW  RMY 26
10/22  70/54/62/+13/0.00/471/73          18 SSW   AERO 17 SSW  RMY N/A
10/23  68/52/60/+11/0.00/340/53          18 ESE   AERO 18 ESE  RMY 18
10/24  68/42/55/+6/0.00/217/34           32 NNW   AERO 32 NNW  RMY 32
10/25  50/40/45/-4/0.00/134/21           19 NNW   AERO 19 NNW  RMY N/A
10/26  52/43/48/0/0.02/000/00            20 E     AERO 18 ESE  RMY 20
10/27  52/43/48/0/T/038/06               22 NNW   AERO 22 NNW  RMY N/A
10/28  49/42/46/-2/0.33/000/00           18 W     AERO 18 W    RMY 18
10/29  46/41/44/-3/1.26/000/00           39 NE    AERO 38 NE   RMY 38
10/30  41/26/34/-13/0.94/000/00          37 NNE   AERO 44 NNE  RMY N/A
10/31  39/24/32/-15/0.00/596/96          18 SSE   AERO 20 SSE  RMY 17

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/…/..     40 SW    AERO 44 SW   RMY 45
11/12   64/46/55/+12/0.04/0.0/…/..     32 NNW   AERO 31 NNW  RMY 33
11/13   48/38/43/0/0.30/0.0/…/..       22 NW    AERO 21 NW   RMY 25
11/14   49/32/41/-1/0.00/0.0/…/..      26 NW    AERO 28 NW   RMY 29
11/15   58/30/44/+2/0.62/0.0/…/..      60 S     AERO 67 S    RMY 65
11/16   53/39/46/+4/0.00/0.0/…/..      40 WNW   AERO 41 WNW  RMY 43
11/17   47/32/40/-1/0.00/0.0/…/..      28 NW    AERO 28 NW   RMY 30
11/18   32/19/26/-15/0.00/0.0/…/..     40 NW    AERO 46 NW   RMY 43
11/19   44/18/31/-10/0.00/0.0/…/..     37 SW    AERO 39 SW   RMY 43

11/20 The low since midnight is 44F, the daily normal low is 32F

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

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

RECORDS FOR NOVEMBER 20
HIGH 72 IN 1953
LOW 10 IN 1894
PRECIP 2.78 INS IN 1988
SNOWFALL 3.0 INS IN 1897
PEAK GUST 73e S IN 1950

RECORDS FOR NOVEMBER 21
HIGH 69 IN 1931
LOW 10 IN 1888
PRECIP 2.60 INCHES IN 1950
SNOWFALL 4.0 INS IN 1929
PEAK GUST 69 NW IN 1989

TODAY’S REPORT PREPARED BY: Andrew Swanson

Category: Daily Discussions

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