Monday, December 23, 2024

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

MONDAY, DECEMBER 23, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0711E
SUNSET: 1616E

ANOTHER VERY COLD DAY DESPITE PLENTY OF SUNSHINE….

We had another morning in which the mercury dipped into the single
digits, and it was even colder than yesterday morning. Our low this
morning dropped to 4F, which is now the coldest temperature we’ve
recorded in 2024 to date, and only the second time we have been
below 10F this year. The previous lowest temperature this year
before yesterday was 10F on January 20th and 21st. This morning was
also the coldest reading we’ve had since February 4, 2023 when the
temperature dipped to an impressive -14F!

Sunshine has been the theme for the most part today, although an
area of low to mid level clouds did move across the sky for a time
blocking the sun. Otherwise, mainly high thin clouds are increasing
starting late this morning and into this afternoon as our next
system approaches. For now, high pressure is cresting over the
region, so it’ll assure one last nice day today.

It’s still quite cold (well below normal), but not as cold as
yesterday afternoon when readings failed to reach 20F. We have
reaching the low to mid 20s today so far at least. With the light
wind, it really doesn’t feel too bad in the sun.

The wind has been decreasing through the morning, after being steady
overnight at around 10-12mph. The wind has even gone calm at times
during the mid morning hours. It has become light and variable as
we push into the afternoon hours. The average speed for the day so
far is around 10mph, but again, most of that is due to the steady
speed prior to 7am this morning. The peak gust for the day is 20mph,
which occurred at 1:48am.

Visibility has been a bit limited due to trapped pollution under the
inversion creating haziness, holding the view to around 50-60 miles.

The maximum temperature for today is 25F degrees, which is 13 degrees
below the normal high of 38F. The minimum temperature since midnight
is 4F degrees, which is 19 degrees below the normal low of 23F.
————————————————————–

Today’s Observations:

7 A.M.
Weather: Clear, few stratocumulus along shore distant NNE-SE-SSW
Temperature: 5F; Dew Point: 0F; Relative Humidity: 78%
Wind: N @ 9 kts
Sea-level pressure: 1037.1 mb; 30.63 in. Hg: rising, then more rapidly
Visibility: 50 miles
6-hr Max temp: 7F
6-hr Min temp: 4F
24-hr Precip: 0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 7 inches
BHO SA 1155 CLR 50 371/5/0/3509/063/ FEW SC ALNG SHR DSNT NNE-SE-SSW/
8/500 4/007 53011 10007 20004

10 A.M.
Weather: Clear, few stratocumulus distant NE-SE-WSW, few altocumulus
distant W-N, few cirrus all quadrants, thin smoke layer along horizon
all quadrants
Temperature: 19F; Dew Point: 8F; Relative Humidity: 62%
Wind: Calm
Sea-level pressure: 1038.3 mb; 30.66 in. Hg: rising, then falling
Visibility: 50 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 50 383/19/8/0000/066/ FEW SC DSNT NE-SE-WSW FEW AC DSNT
W-N FEW CI ALQDS THN K LYR ALNG HRZN ALQDS WND CALM/ 8/551 50012

1 P.M.
Weather: Thin broken cirrus, few stratocumulus all quadrants, few
altocumulus distant WSW-NNE
Temperature: 24F; Dew Point: 11F; Relative Humidity: 58%
Wind: SW @ 4 kts, wind light
Sea-level pressure: 1036.5 mb; 30.61 in. Hg: falling, then more rapidly
Visibility: 60 miles
6-hr Max temp: 25F
6-hr Min temp: 5F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 7 inches
BHO SA 1755 E250 -BKN 60 365/24/11/2204/061/ FEW SC ALQDS FEW AC DSNT
WSW-NNE WND LGT/ 8/551 4/007 58018 10025 20005

————————————————————–

SUMMARY FOR SUNDAY, DECEMBER 22, 2024

TEMPERATURE (DEGREES F)
MAX…….17 NORMAL…..39
MIN……..6 NORMAL…..23
MEAN……12 NORMAL…..31

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………-19
TOTAL DEPARTURE FOR THE MONTH……………………-27 [-1.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………53 DEPARTURE…….+19
TOTAL HEATING UNITS FOR THE MONTH…………..714 DEPARTURE…….+26
TOTAL HEATING UNITS FOR THE SEASON…………1657 DEPARTURE……-234
TOTAL HEATING UNITS LAST SEASON TO DATE…….1674 DEPARTURE…….-17

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

F420C (Official)………..33 NW @ 12:07 A.M.
VECTOR #1 (1-Sec)……….33 NW @ 12:07 A.M.
VECTOR #2 (1-Sec)……….34 NW @ 12:27 A.M.
DAVIS #1……………….31 WNW @ 12:07 A.M.
DAVIS #2 ………………30 NW @ 12:27 A.M.
RMY #1 (Instantaneous)…..35 NW @ 12:07 A.M.
RMY #2 (Instantaneous)…..34 NW @ 12:27 A.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………24 NW @ 12:08 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..23 @ 12:08 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..24 @ 12:08 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………24 NW @ 12:08 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………23 NW @ 12:08 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..24 NW @ 12:09 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..23 NW @ 12:08 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..13.0 NW [313 total miles] VECTOR #1………………13.0
VECTOR #2………………13.6
DAVIS #1……………….13.3 NW
DAVIS #2……………….13.2 NNW
RMY #1…………………12.9 NW
RMY #2…………………13.3 NW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.18
TOTAL PRECIPITATION FOR THE MONTH…………..6.66 DEPARTURE…..+2.74
TOTAL PRECIPITATION FOR THE YEAR (2024)…….54.13 DEPARTURE…..+1.74

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……-0.4
TOTAL SNOWFALL FOR THE MONTH……………….12.4 DEPARTURE……+4.4
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……12.4 DEPARTURE……+1.9

————————————————————–

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 37/23/30/-7/0.00/0.0/452/81 21 WSW VEC1 21 WSW RMY 21
12/2 38/22/30/-7/0.00/0.0/551/99 18 W VEC1 18 W RMY 18
12/3 36/20/28/-8/0.00/0.0/411/74 21 NW VEC1 21 WNW RMY 21
12/4 39/22/31/-5/0.13/T/394/71 30 S VEC1 31 S RMY 33
12/5 37/31/34/-2/0.40/3.0/072/13 43 WNW VEC1 43 WNW RMY 47
12/6 31/23/27/-8/0.00/0.0/514/93 39 NW VEC1 39 W RMY 42
12/7 37/22/30/-5/T/T/408/74 25 S VEC1 25 S RMY 26
12/8 47/28/38/+3/0.02/T/198/36 37 SSW VEC1 37 SSW RMY 40
12/9 47/34/41/+7/0.41/0.0/187/34 28 ENE VEC1 28 E RMY 29
12/10 42/31/37/+3/0.15/0.0/000/00 31 NE VEC1 32 NE RMY 34
12/11 62/36/49/+15/3.38/0.0/000/00 65 SSW VEC1 67 SSW RMY 70 TSTM
12/12 53/25/39/+5/0.05/0.0/460/84 51 WNW VEC1 49 WNW RMY 51
12/13 31/19/25/-8/0.00/0.0/514/94 30 WNW VEC1 30 W RMY 30
12/14 33/17/25/-8/0.00/0.0/546/100 20 NW VEC1 19 NNW RMY 20
12/15 34/17/26/-7/0.00/0.0/377/69 17 N VEC1 17 N RMY 16
12/16 45/29/37/+5/T/0.0/005/01 35 SSE VEC1 35 SSE RMY 35
12/17 59/41/50/+18/0.25/0.0/360/66 48 SSW VEC1 50 SSW RMY 50
12/18 50/36/43/+11/0.57/0.0/507/93 21 S VEC1 21 S RMY 21
12/19 44/30/37/+5/0.13/0.0/…/.. 31 NW VEC1 31 NW RMY 32
12/20 32/24/28/-3/1.17/9.4/000/00 28 NNE VEC1 29 N RMY 29
12/21 26/12/19/-12/0.00/0.0/…/.. 38 NW VEC1 38 NW RMY 41
12/22 17/6/12/-19/0.00/0.0/…/.. 33 NW VEC1 33 NW RMY 35