Thursday, December 5, 2024

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

THURSDAY, DECEMBER 5, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0658E
SUNSET:  1612E

FIRST SNOWFALL OF THE SEASON AS EARLY WINTER ROLLS ON….

The first flakes of the season actually flew last evening as a
warm frontal band of snow showers moved through. Thereafter,
snow changed to rain during the latter half of the evening which
continued until around 1:30am this morning. At this point snow
began to mix back in with the rain, and a change to all snow
occurred shortly after 2am. Light to at times moderate snow
fell until it ended around 10:30am. 1.8″ of snow was measured
through 7am, which an additional 1.2″ falling by 10am, giving us
a total of 3.0″ for this event.

A brief period of partial sunshine was observed early this
afternoon before clouds took over once again. A few snow pellets
have been observed during the mid afternoon.

Temperatures have been on a bit of a roller coaster the last 24
hours, dropping from the upper 30s yesterday afternoon, to near
freezing during the early to mid evening hours, then back to the
upper 30s by late evening through about 1am, then back down to
near freezing again by 3am through the duration of the snow event.
We did reach the mid 30s again early this afternoon, allowing for
some melting of the new snow.

The wind has also seen ups and downs, which a period of gusty
winds prior to 2am this morning, then generally steady around 10mph
through the morning, picking up again for a time around noon into
early this afternoon. The average speed for the day so far is
around 12mph. The peak gust for the day so far is 31mph, which
occurred at 1:37am this morning.

Visibility started the day extremely low between the snow and being
in the clouds this morning. The view (if we can call it that) was
only around 1/16th of a mile. Visibility improved once the snow
moved out late this morning and through this afternoon, rising to
around 25-30 miles.

The maximum temperature for today is 37F degrees, which is 6 degrees
below the normal high of 43F. The minimum temperature since midnight
is 31F degrees, which is 3 degrees above the normal low of 28F.

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Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200ft, very light snow
Temperature: 32F; Dew Point: 32F; Relative Humidity: 100%
Wind: SW @ 11 kts
Sea-level pressure: 1000.6 mb; 29.55 in. Hg: falling, then more slowly
Visibility: 1/16 mile, fog
6-hr Max temp: 37F
6-hr Min temp: 31F
24-hr Precip:  0.43 inches
24-hr Snowfall: 1.8 inches
Snow Depth: 2 inches
BHO SA 1155 X W2 1/16S-F 006/32/32/2211/955/ PCPN VRY LGT
SLGT RIME ICING TOTAL NEW SNW PST 24 HRS 1.8 INS/ 8//// 4/002
56020 6025/ 70043 10037 20031

10 A.M.
Weather: Sky obscured, vertical visibility 200ft, light snow
Temperature: 33F; Dew Point: 33F; Relative Humidity: 100%
Wind: SW @ 9 kts
Sea-level pressure: 997.7 mb; 29.46 in. Hg: falling, then more rapidly
Visibility: 1/4 mile, fog
3-hr Precip:  0.10 inches
3-hr Snowfall: 1.2 inches
BHO SA 1455 X W2 1/4S-F 977/33/33/2309/946/ TOTAL NEW SNW PST
3 HRS 1.2 INS/ 8//// 58029 6010/

1 P.M.
Weather: Broken stratocumulus
Temperature: 36F; Dew Point: 34F; Relative Humidity: 92%
Wind: W @ 12G19 kts
Sea-level pressure: 995.9 mb; 29.41 in. Hg: falling, then more slowly
Visibility: 25 miles, thin fog
6-hr Max temp: 37F
6-hr Min temp: 32F
6-hr Precip:  0.10 inches
6-hr Snowfall: 1.2 inches
Snow Depth: 2 inches
BHO SA 1755 E25 BKN 25 959/36/34/2612G19/941/ THN F ALQDS NEW SNW
PST 6 HRS 1.2 INS/ 8/500 4/002 56018 6010/ 10037 20032

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SUMMARY FOR WEDNESDAY, DECEMBER 4, 2024

TEMPERATURE (DEGREES F)
MAX…….39  NORMAL…..44
MIN…….22  NORMAL…..28
MEAN……31  NORMAL…..36

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………..-5
TOTAL DEPARTURE FOR THE MONTH…………………….-27 [-7.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………34  DEPARTURE……..+5
TOTAL HEATING UNITS FOR THE MONTH…………..141  DEPARTURE…….+27
TOTAL HEATING UNITS FOR THE SEASON…………1084  DEPARTURE……-234
TOTAL HEATING UNITS LAST SEASON TO DATE…….1170  DEPARTURE…….-86

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)………..30 S    @   08:45 P.M.
VECTOR #1 (1-Sec)……….31 S    @   08:45 P.M.
VECTOR #2 (1-Sec)……….30 SSE  @   07:44 P.M.
DAVIS #1……………….31 S    @   08:45 P.M.
DAVIS #2 ………………41 S    @   08:44 P.M.
RMY #1 (Instantaneous)…..33 S    @   08:45 P.M.
RMY #2 (Instantaneous)…..32 SSE  @   08:24 P.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………22 SSE  @   08:12 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..21      @   08:14 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..21      @   08:45 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 SSE  @   08:14 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………25 S    @   08:48 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..20 SSE  @   08:14 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..22 SSE  @   08:45 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.2 WNW [244 total miles] VECTOR #1………………10.5
VECTOR #2………………11.1
DAVIS #1……………….10.3 SSW
DAVIS #2……………….11.1 SSW
RMY #1…………………10.2 SW
RMY #2…………………11.1 SW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.43 DEPARTURE…..+0.25
TOTAL PRECIPITATION FOR THE MONTH…………..0.43 DEPARTURE…..-0.27
TOTAL PRECIPITATION FOR THE YEAR (2024)…….47.90 DEPARTURE…..-1.27

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..1.8 DEPARTURE……+1.6
TOTAL SNOWFALL FOR THE MONTH………………..1.8 DEPARTURE…..+0.9
TOTAL SNOWFALL FOR THE SEASON (2024-2025)…….1.8 DEPARTURE……-1.6

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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   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 The low since midnight is 31F, the daily normal low is 28F.

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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 5
HIGH 65 IN 2001
LOW -1 IN 1926
PRECIP 2.86 INS. IN 1993
SNOWFALL 7.0 INS. IN 1893, 1895, 1926, 1981
PEAK GUST 67 MPH WNW IN 1961, S IN 1973

RECORDS FOR DECEMBER 6
HIGH 70 IN 2001
LOW 5 IN 1901,1935
PRECIP 2.78 INS. IN 2003
SNOWFALL 17.0 INS. IN 2003
PEAK GUST 74 MPH NW IN 1981

TODAY’S REPORT PREPARED BY: Matt Douglas