Wednesday, December 13, 2023

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

WEDNESDAY, DECEMBER 13, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0705E
SUNSET:  1612E

MAINLY SUNNY SKIES, SEASONABLE TEMPERATURES, AND A BRISK WIND TODAY….

Skies were clear all morning, but some stratocumulus clouds began
dotting the sky early this afternoon. Cloud coverage is tending to
increase ahead of an arctic front, and snow showers associated with
the boundary can be seen well off to the northwest through north
across southern New Hampshire!

Temperatures are seasonable for this time of year with readings
getting into the low 40s early this afternoon. The dew point has
been gradually slipping from the mid 20s early this morning to
around 20 early this afternoon.

The wind has been brisk today, mainly out of a west to west-
northwesterly direction. The average speed for the day thus far
is around 13mph. The peak gust for the day so far is 28mph.

Visibility has been somewhat limited today due to haziness. The
view all morning was around 40 miles, but it has improved to
around 60 miles early this afternoon.

The maximum temperature for today is 43F degrees, this is 2 degrees
above the normal high of 41F. The minimum temperature since midnight
is 31F degrees, this is 5 degrees above the normal low of 26F.

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Today’s Observations:

7 A.M.
Weather: Clear, few cirrus distant E-S
Temperature: 31F; Dew Point: 25F; Relative Humidity: 78%
Wind: WNW @ 12G17 kts
Sea-level pressure: 1028.5 mb; 30.37 in. Hg: rising, then steady
Visibility: 40 miles, hazy
6-hr Max temp: 35F
6-hr Min temp: 31F
24-hr Precip:  0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 CLR 40 285/31/25/2912G17/037/ FEW CI DSNT E-S HAZY/ 8/001
51008 10035 20031

10 A.M.
Weather: Clear, few stratocumulus distant WSW-N, few cirrus distant E-SSW
Temperature: 39F; Dew Point: 23F; Relative Humidity: 52%
Wind: W @ 13G23 kts
Sea-level pressure: 1029.1 mb; 30.39 in. Hg: rising, then steady
Visibility: 40 miles, hazy
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 40 291/39/23/2813G23/039/ FEW SC DSNT WSW-N FEW CI DSNT
E-SSW HAZY/ 8/501 51006

1 P.M.
Weather: Scattered stratocumulus, few cirrus distant SE-SW
Temperature: 42F; Dew Point: 20F; Relative Humidity: 41%
Wind: W @ 13G22 kts
Sea-level pressure: 1027.2 mb; 30.33 in. Hg: falling, then more slowly
Visibility: 60 miles
6-hr Max temp: 43F
6-hr Min temp: 31F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E50 SCT 60 272/42/20/2813G22/033/ FEW CI DSNT SE-SW/ 8/501
56019 10043 20031

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SUMMARY FOR TUESDAY, DECEMBER 12, 2023

TEMPERATURE (DEGREES F)
MAX…….42   NORMAL…..41
MIN…….29   NORMAL…..26
MEAN……36   NORMAL…..34

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………..+2
TOTAL DEPARTURE FOR THE MONTH………………….+49 [+3.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY……………29  DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE MONTH…………..308  DEPARTURE…….-50
TOTAL HEATING UNITS FOR THE SEASON…………1395  DEPARTURE……-167
TOTAL HEATING UNITS LAST SEASON TO DATE…….1298  DEPARTURE…….+97

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)……….E33 WNW  @  12:00 A.M.
VECTOR #1 (1-Sec)……….32 WNW  @  12:54 A.M.
VECTOR #2 (1-Sec)……….34 WNW  @  12:35 A.M.
DAVIS #1……………….32 W    @  12:00 A.M.
DAVIS #2 ………………32 W    @  12:35 A.M.
RMY #1 (Instantaneous)…..34 WNW  @  12:54 A.M.
RMY #2 (Instantaneous)…..35 WNW  @  12:35 A.M.
MERLIN…………………M
RICHARDS (C5C) (Inst)……32      @  12:00 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………26 WNW  @  12:02 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..23      @  12:01 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..24      @  12:01 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………24 W    @  12:01 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………24 WNW  @  12:01 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 WNW  @  12:01 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..23 WNW  @  12:01 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………23      @  12:01 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….12.6 SW [302 total miles] VECTOR #1……………..12.5
VECTOR #2……………..13.3
DAVIS #1………………12.5 WSW
DAVIS #2………………13.2 W
RMY #1………………..12.2 WSW
RMY #2………………..13.1 WSW
RICHARDS (C5C)…………12.3

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.18
TOTAL PRECIPITATION FOR THE MONTH…………..3.50 DEPARTURE…..+1.35
TOTAL PRECIPITATION FOR THE YEAR…………..54.87 DEPARTURE…..+4.25

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……-3.4
TOTAL SNOWFALL FOR THE SEASON (2023-2024)…….0.3 DEPARTURE……-5.9

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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/…/..        18 NNW VEC1 18 NW  RMY 19
12/8  42/24/33/-2/0.00/0.0/…/..         20 S   VEC1 18 S   RMY 18
12/9  52/33/43/+9/0.00/0.0/…/..         24 S   VEC1 24 S   RMY 24
12/10 60/43/52/+18/0.66/0.0/…/..        55 SSW VEC1 54 SSW RMY 53
12/11 61/33/47/+13/1.96/0.0/…/..        69 SSW VEC1 69 SSW RMY 71
12/12 42/29/36/+2/0.00/0.0/…/..         33 WNW VEC1 32 WNW RMY 34

12/13 The low since midnight is 31F, the daily normal low is 26F

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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 13
HIGH 60 IN 1984
LOW 0 IN 1893
PRECIP 1.45 INS. IN 1983
SNOWFALL 9.2 INS. IN 2007
PEAK GUST 81e WNW IN 1976

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

TODAY’S REPORT PREPARED BY: Matt Douglas