Saturday, December 16, 2023

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

SATURDAY, DECEMBER 16, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0707E
SUNSET:  1613E

BEAUTIFUL, SUNNY AND WARM DAY ON BLUE HILL….

Mostly clear skies have been the theme today, with just a bit of
cirrus allowing for lots of sunshine! Combined with warm temperatures
and a light breeze, it has been a beautiful day so far up here on
Great Blue Hill.

Temperatures remain above average again today, beginning the morning
in the upper 30s and rising to the low 50s around noon time. Since then,
they have fallen back to the upper 40s, around the same time we experienced
a shift in wind direction, now coming in off the ocean. Dew points have
remained steady in the low 30s all day.

Winds were more active overnight, but since this morning have slowed
noticeably. Our average speed so far is only about 10mph. The peak gust
so far occurred just before 7am this morning, with a speed of about
24mph.

Visibility was limited this morning to 30 miles, but by the 1pm
observation has risen to 60 miles!

The maximum temperature for today is 50F degrees, this is 10 degrees
above the normal high of 40F. The minimum temperature since midnight
is 37F degrees, this is 12 degrees above the normal low of 25F.

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Today’s Observations:

7 A.M.
Weather: Clear, few altocumulus distant NE-E, few cirrus all quadrants,
few cirrostratus distant NW-NE
Temperature: 38F; Dew Point: 34F; Relative Humidity: 82%
Wind: NW @ 13G18 kts
Sea-level pressure: 1029.2 mb; 30.39 in. Hg: rising, then more slowly
Visibility: 30 miles
6-hr Max temp: 41F
6-hr Min temp: 37F
24-hr Precip:  0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 CLR 30 292/38/34/3213G18/039/ FEW AC DSNT NE-E FEW CI ALQDS
FEW CS DSNT NW-NE/ 8/055 51024 10041 20037

10 A.M.
Weather: Clear, few altocumulus distant W-WNW, few cirrus all quadrants
Temperature: 46F; Dew Point: 33F; Relative Humidity: 60%
Wind: N @ 7G15 kts
Sea-level pressure: 1032.5 mb; 30.49 in. Hg: rising, then more slowly
Visibility: 40 miles, thin smoke layer along horizon all quadrants
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 40 325/46/33/3607G15/049/ FEW AC DSNT W-WNW FEW CI ALQDS
THN K LYR ALNG HRZN ALQDS/ 8/051 51033

1 P.M.
Weather: Clear, few altocumulus offshore distant ENE-ESE,
few cirrus all quadrants
Temperature: 48F; Dew Point: 33F; Relative Humidity: 55%
Wind: E @ 7 kts
Sea-level pressure: 1032.2 mb; 30.48 in. Hg: falling unsteadily
Visibility: 60 miles
6-hr Max temp: 50F
6-hr Min temp: 38F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 CLR 60 322/48/33/0907/048/ FEW AC OFFSHR DSNT ENE-ESE
FEW CI ALQDS/ 8/051 57003 10050 20038

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SUMMARY FOR FRIDAY, DECEMBER 15, 2023

TEMPERATURE (DEGREES F)
MAX…….53   NORMAL…..40
MIN…….30   NORMAL…..25
MEAN……42   NORMAL…..33

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………..+9
TOTAL DEPARTURE FOR THE MONTH………………….+56 [+3.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY……………23  DEPARTURE……..-9
TOTAL HEATING UNITS FOR THE MONTH…………..397  DEPARTURE…….-57
TOTAL HEATING UNITS FOR THE SEASON…………1484  DEPARTURE……-147
TOTAL HEATING UNITS LAST SEASON TO DATE…….1402  DEPARTURE…….+82

PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all Main Tower.
E=Estimated

F420C (Official)……….E31 WNW  @  01:56 P.M.
VECTOR #1 (1-Sec)……….30 WNW  @  01:56 P.M.
VECTOR #2 (1-Sec)……….31 WNW  @  01:56 P.M.
DAVIS #1……………….30 W    @  01:56 P.M.
DAVIS #2 ………………31 WNW  @  01:56 P.M.
RMY #1 (Instantaneous)…..28 WNW  @  01:56 P.M.
RMY #2 (Instantaneous)…..31 WNW  @  01:56 P.M.
MERLIN…………………28 W
RICHARDS (C5C) (Inst)……31      @  01:56 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 WNW  @  12:26 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..20      @  12:28 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..22      @  01:57 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 W    @  12:28 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………21 WNW  @  01:57 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 W    @  12:28 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..21 WNW  @  01:57 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………20      @  01:57 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….13.3 W [320 total miles] VECTOR #1……………..13.3
VECTOR #2……………..14.0
DAVIS #1………………13.7 WSW
DAVIS #2………………14.0 W
RMY #1………………..12.9 W
RMY #2………………..13.8 W
RICHARDS (C5C)…………13.1

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.17
TOTAL PRECIPITATION FOR THE MONTH…………..3.50 DEPARTURE…..+0.82
TOTAL PRECIPITATION FOR THE YEAR…………..54.87 DEPARTURE…..+3.72

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……-0.4
TOTAL SNOWFALL FOR THE MONTH………………..0.3 DEPARTURE……-4.6
TOTAL SNOWFALL FOR THE SEASON (2023-2024)…….0.3 DEPARTURE……-7.1

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PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN)/SUN(%)/PEAK GUST/VEC1/RMY GUST
PEAK GUST: F420C (Official)
VEC1: Vector #1 1-second gust
RMY:  R.M. Young #1 wind gust recording system (Instantaneous)
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

12/1  51/38/45/+8/0.04/0.0/213/38         29 SW  VEC1 28 SW  RMY 29
12/2  48/43/46/+9/T/0.0/000/00            18 SSW VEC1 19 SSW RMY 19
12/3  44/41/43/+7/0.76/0.0/000/00         31 ENE VEC1 32 ENE RMY 33
12/4  49/37/43/+7/0.07/0.0/155/28         23 W   VEC1 22 W   RMY 23
12/5  38/28/33/-3/0.00/0.0/144/26         23 NNW VEC1 24 NW  RMY 24
12/6  34/22/28/-7/0.01/0.3/100/18         21 N   VEC1 21 N   RMY 20
12/7  28/17/56/-12/0.00/0.0/121/22        18 NNW VEC1 18 NW  RMY 19
12/8  42/24/33/-2/0.00/0.0/530/96         20 S   VEC1 18 S   RMY 18
12/9  52/33/43/+9/0.00/0.0/264/48         24 S   VEC1 24 S   RMY 24
12/10 60/43/52/+18/0.66/0.0/033/06        55 SSW VEC1 54 SSW RMY 53
12/11 61/33/47/+13/1.96/0.0/038/07        69 SSW VEC1 69 SSW RMY 71
12/12 42/29/36/+2/0.00/0.0/543/99         33 WNW VEC1 32 WNW RMY 34
12/13 43/28/36/+3/0.00/0.0/470/86         36 WNW VEC1 34 WNW RMY 36
12/14 34/22/28/-5/0.00/0.0/…/..         31 SW  VEC1 31 SW  RMY 32
12/15 53/30/42/+9/0.00/0.0/…/..         31 WNW VEC1 30 WNW RMY 28

12/16 The low since midnight is 37F, the daily normal low is 25F

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DECEMBER DAILY RECORDS TO DATE

NONE…

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

RECORDS FOR DECEMBER 16
HIGH 61 IN 1971
LOW -2 IN 1930
PRECIP 1.88 INS. IN 2022
SNOW 8.5 INS. IN 2007
WIND 73 MPH SSE IN 1982

RECORDS FOR DECEMBER 17
HIGH 63 IN 2000
LOW -9 IN 1942
PRECIP 3.03 INS. IN 1888
SNOWFALL 15.1 INS. IN 2020
PEAK GUST 78 MPH SSE IN 2000

TODAY’S REPORT PREPARED BY: Joshua Polen