Thursday, December 12, 2024

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

THURSDAY, DECEMBER 12, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0704E
SUNSET:  1612E

RECORD PRECIPITATION YESTERDAY AS A POWERFUL STORM SYSTEM PASSED
THROUGH THE REGION….

The big story is the amount of water that fell from the sky yesterday
as some places across southern New England had upwards of 5 inches
of rain, mainly across northwestern Rhode Island. Here at Blue Hill,
the storm total was 3.44 inches, 3.38 inches of which fell on the
calendar day yesterday setting a new record for the date. This smashed
the previous record of 2.36″ set in 1992.

The rain was also accompanied by strong gusty winds. The official
peak gust here was 65mph, however we had several gusts of 60+mph, and
several hours of winds gusting over 50mph.

There was even a thunderstorm observed during the evening, giving us
the first thunderstorm day since August 19th!

Today the sun has returned, mixing with some low level stratocumulus
clouds. Strong cold air advection is taking place, as such the
temperature has had a hard time rising today. It did make it into the
low 40s briefly late this morning, but has since settled back into
the upper 30s as the advection increases.

The wind has also increased after lowering a bit early this morning
from the strong overnight values. The average speed for the day so
far is around 18mph. The peak gust for the day occurred at 1:24am with
a value of 51mph. However, gusts late this morning and early this
afternoon are pushing over 40mph as the strong cold air advection
helps to maximize mixing of the stronger winds aloft toward the
surface.

Visibility has been decent today, generally hanging around in the
50-60 mile range all day.

The maximum temperature for today is 53F degrees back at midnight,
which is 12 degrees above the normal high of 41F. The minimum
temperature since midnight is 33F degrees, which is 7 degrees above
the normal low of 26F.

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Today’s Observations:

7 A.M.
Weather: Clear, few stratocumulus distant all quadrants,
few cirrostratus distant NNE-SE
Temperature: 33F; Dew Point: 27F; Relative Humidity: 78%
Wind: W @ 14G22 kts, peak wind W 31mph at 6:21 A.M.
Sea-level pressure: 1011.1 mb; 29.86 in. Hg: rising, then more slowly
Visibility: 60 miles
6-hr Max temp: 47F
6-hr Min temp: 33F
24-hr Precip:  3.31 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 CLR 60 111/33/27/2614G22/986/ FEW SC DSNT ALQDS FEW CS DSNT
NNE-SE PK WND 2827/21/ 8/508 51059 6001/ 70331 10047 20033

10 A.M.
Weather: Clear, few stratocumulus all quadrants
Temperature: 37F; Dew Point: 24F; Relative Humidity: 58%
Wind: WSW @ 15G26 kts, peak wind WSW 31mph at 9:40 A.M.
Sea-level pressure: 1015.5 mb; 29.99 in. Hg: rising, then more slowly
Visibility: 50 miles
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 50 155/37/24/2515G26/999/ FEW SC ALQDS PK WND 2527/40/
8/500 51044

1 P.M.
Weather: Broken stratocumulus
Temperature: 39F; Dew Point: 22F; Relative Humidity: 50%
Wind: W @ 20G30 kts, peak wind W 41mph at 12:30 P.M.
Sea-level pressure: 1015.6 mb; 29.99 in. Hg: falling, then rising
Visibility: 60 miles
6-hr Max temp: 41F
6-hr Min temp: 33F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E50 BKN 60 156/39/22/2820G30/999/ PK WND 2636/30/
8/500 53001 10041 20033

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SUMMARY FOR WEDNESDAY, DECEMBER 11, 2024

TEMPERATURE (DEGREES F)
MAX…….62  NORMAL…..41
MIN…….36  NORMAL…..26
MEAN……49  NORMAL…..34

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………….+15
TOTAL DEPARTURE FOR THE MONTH…………………….-14 [-1.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………16  DEPARTURE…….-15
TOTAL HEATING UNITS FOR THE MONTH…………..340  DEPARTURE…….+13
TOTAL HEATING UNITS FOR THE SEASON…………1283  DEPARTURE……-247
TOTAL HEATING UNITS LAST SEASON TO DATE…….1366  DEPARTURE…….-83

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)………..65 SSW  @   06:50 P.M.
VECTOR #1 (1-Sec)……….67 SSW  @   06:49 P.M.
VECTOR #2 (1-Sec)……….69 SSW  @   06:50 P.M.
DAVIS #1……………….72 S    @   03:18 P.M.
DAVIS #2 ………………78 S    @   04:01 P.M.
RMY #1 (Instantaneous)…..70 SSW  @   06:50 P.M.
RMY #2 (Instantaneous)…..72 S    @   04:07 P.M.
MERLIN…………………63 S
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………49 SSW  @   06:51 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..49      @   06:52 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..51      @   06:52 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………50 S    @   06:52 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………53 S    @   06:52 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..48 SSW  @   06:52 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..52 S    @   06:52 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..21.6 SSW [519 total miles] VECTOR #1………………21.1
VECTOR #2………………22.0
DAVIS #1……………….21.1 S
DAVIS #2……………….22.9 S
RMY #1…………………20.6 S
RMY #2…………………22.2 S
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..3.31 DEPARTURE…..+3.13
TOTAL PRECIPITATION FOR THE MONTH…………..4.54 DEPARTURE…..+2.57
TOTAL PRECIPITATION FOR THE YEAR (2024)…….52.01 DEPARTURE…..+1.75

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……-0.4
TOTAL SNOWFALL FOR THE MONTH………………..3.0 DEPARTURE……-0.3
TOTAL SNOWFALL FOR THE SEASON (2024-2025)…….3.0 DEPARTURE……-2.7

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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   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 The low since midnight is 33F, the daily normal low is 26F.

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DECEMBER DAILY RECORDS TO DATE

12/11 NEW PRECIPITATION RECORD OF 3.38″; OLD RECORD 2.36″ IN 1992

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

RECORDS FOR DECEMBER 12
HIGH 67 IN 1979
LOW -3 IN 1988
PRECIP 3.94 INS. IN 1992
SNOWFALL 20.3 INS. IN 1960
PEAK GUST 75 MPH SSE IN 2008

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

TODAY’S REPORT PREPARED BY: Matt Douglas