Tuesday, December 17, 2024

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

TUESDAY, DECEMBER 17, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0708E
SUNSET:  1613E

OVERNIGHT RAIN ENDS THIS MORNING, GRADUAL CLEARING WITH MILD
TEMPERATURES FOR THE BALANCE OF THE DAY….

Another weak system pushes through the region overnight into early
this morning bringing periods of rain to the area. 0.25″ of rain was
measured from this latest event. Rain moved out of the area this
morning with gradual clearing taking place thereafter. All in all,
it’s been quite a nice day for mid December standards.

Temperatures are on the mild side today with readings into the upper
50s. This is nearly 20 degrees above the normal values expected for
the date! The dew point was also in the low to mid 50s this morning,
but has eased back to the mid to upper 40s early this afternoon.
Either way, there is a bit of a humid feel to the air, especially when
compared to the low values we had days prior.

Winds became quite gusty overnight into this morning out of the south-
southwest. Gusts approached 50mph overnight. However, the wind has
diminished as we move into the late morning and early afternoon hours.
The average speed for the day so far is around 20mph, but as mentioned,
it has settled back to around 10-12mph for the last couple of hours
or so. The peak gust for the day is 48mph, which occurred at 3am this
morning.

Visibility improved markedly since early this morning, going from
around 20-25 miles up to 70 miles.

The maximum temperature for today is 59F degrees, which is 19 degrees
above the normal high of 40F. The minimum temperature since midnight
is 45F degrees, which is 20 degrees above the normal low of 25F.

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Today’s Observations:

7 A.M.
Weather: Broken stratus fractus, broken stratocumulus, overcast nimbostratus,
few lower stratus fractus all quadrants
Temperature: 54F; Dew Point: 54F; Relative Humidity: 100%
Wind: SSW @ 17G27 kts, peak wind SSW 37mph at 6:18 A.M.
Sea-level pressure: 1016.2 mb; 30.01 in. Hg: falling, then more slowly
Visibility: 25 miles, thin fog
6-hr Max temp: 54F
6-hr Min temp: 46F
24-hr Precip:  0.25 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 E7 BKN 16 BKN 65 OVC 25 162/54/54/2017G27/001/
FEW LWR STFRA ALQDS THN F ALQDS R-E47 PK WND 2132/18/ 8/72/
56006 6025/ 70025 10054 20046

10 A.M.
Weather: Broken stratocumulus, overcast altocumulus, few breaks in
overcast all quadrants
Temperature: 53F; Dew Point: 51F; Relative Humidity: 90%
Wind: WSW @ 15G25 kts, peak wind WSW 30mph at 9:39 A.M.
Sea-level pressure: 1017.6 mb; 30.05 in. Hg: falling, then rising
Visibility: 70 miles
3-hr Precip:  Trace
3-hr Snowfall: 0.0 inches
BHO SA 1455 E16 BKN 85 OVC 70 176/53/51/2515G25/005/ FEW BINOVC ALQDS
PK WND 2426/39/ 8/55/ 53014 6000/

1 P.M.
Weather: Broken stratocumulus, broken altocumulus/castellanus,
broken cirrostratus, broken cirrus
Temperature: 58F; Dew Point: 47F; Relative Humidity: 67%
Wind: W @ 10G17 kts
Sea-level pressure: 1016.4 mb; 30.01 in. Hg: falling, then rising
Visibility: 70 miles
6-hr Max temp: 59F
6-hr Min temp: 54F
6-hr Precip:  Trace
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E30 BKN 85 BKN 200 BKN 250 BKN 70 164/58/47/2810G17/001/
8/588 55012 6000/ 10059 20054

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SUMMARY FOR MONDAY, DECEMBER 16, 2024

TEMPERATURE (DEGREES F)
MAX…….45  NORMAL…..40
MIN…….29  NORMAL…..25
MEAN……37  NORMAL…..32

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………….+5
TOTAL DEPARTURE FOR THE MONTH……………………-27 [-1.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………28  DEPARTURE……..-5
TOTAL HEATING UNITS FOR THE MONTH…………..513  DEPARTURE…….+26
TOTAL HEATING UNITS FOR THE SEASON…………1456  DEPARTURE……-234
TOTAL HEATING UNITS LAST SEASON TO DATE…….1506  DEPARTURE…….-50

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)………..35 SSE  @   11:48 P.M.
VECTOR #1 (1-Sec)……….35 SSE  @   11:48 P.M.
VECTOR #2 (1-Sec)……….33 SSE  @   11:55 P.M.
DAVIS #1……………….35 SSE  @   11:48 P.M.
DAVIS #2 ………………41 S    @   11:33 P.M.
RMY #1 (Instantaneous)…..35 SSE  @   11:48 P.M.
RMY #2 (Instantaneous)…..36 SSE  @   11:55 P.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………24 SSE  @   10:42 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..24      @   11:50 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..27      @   11:58 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………23 SSE  @   11:50 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 S    @   11:58 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..23 SSE  @   11:50 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..27 SSE  @   11:58 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..11.8 SSE [284 total miles] VECTOR #1………………12.0
VECTOR #2………………12.7
DAVIS #1……………….11.7 SSE
DAVIS #2……………….11.9 SSE
RMY #1…………………11.4 SSE
RMY #2…………………12.8 SE
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.25 DEPARTURE…..+0.07
TOTAL PRECIPITATION FOR THE MONTH…………..4.79 DEPARTURE…..+1.93
TOTAL PRECIPITATION FOR THE YEAR (2024)…….52.26 DEPARTURE…..+0.93

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……-2.3
TOTAL SNOWFALL FOR THE SEASON (2024-2025)…….3.0 DEPARTURE……-4.8

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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  53/25/39/+5/0.05/0.0/…/..        51 WNW VEC1 49 WNW RMY 51
12/13  31/19/25/-8/0.00/0.0/…/..        30 WNW VEC1 30 W   RMY 30
12/14  33/17/25/-8/0.00/0.0/…/..        20 NW  VEC1 19 NNW RMY 20
12/15  34/17/26/-7/0.00/0.0/…/..        17 N   VEC1 17 N   RMY 16
12/16  45/29/37+5/T/0.0/…/..            35 SSE VEC1 35 SSE RMY 35

12/17 The low since midnight is 45F, the daily normal low is 25F.

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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 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

RECORDS FOR DECEMBER 18
HIGH 61 IN 2023
LOW -11 IN 1919
PRECIP 2.47 INS. IN 2023
SNOWFALL 7.0 INS. IN 1904
PEAK GUST 90 SSE IN 2023

TODAY’S REPORT PREPARED BY: Matt Douglas