Sunday, December 17, 2023

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

SUNDAY, DECEMBER 17, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0708E
SUNSET:  1613E

MILD, YET OVERCAST AND DREARY AS THE AIR MASS CHANGES….

Today we observed a low visibility of 20 miles due to distant fog.
The pressure over the course of the day has dropped off by almost
6 millibars, signifying incoming weather from the south. Skies were
overcast with a prevailing layer of cirrostratus in the morning, but
quickly changed over to low-level stratus around noontime.

There is a wind coming in from the east that is around 10 mph with
a highest gust so far today of 22 mph. The breeze feels cool off the
water as milder temperatures persist.

The maximum temperature for today is 49F degrees, this is 9 degrees
above the normal high of 40F. The minimum temperature since midnight
is 37F degrees, this is 12 degrees above the normal low of 25F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Overcast cirrostratus, few distant stratocumulus SE-W-NE,
sun dimly visible
Temperature: 38F; Dew Point: 36F; Relative Humidity: 92%
Wind: E @ 11G17 kts
Sea-level pressure: 1031.5 mb; 30.46 in. Hg: falling, then more rapidly
Visibility: 20 miles, thin fog
6-hr Max temp: 38F
6-hr Min temp: 37F
24-hr Precip:  0.00 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 20 OVC 200 315/38/36/0911G17/046/ FEW SC DSNT SE-W-NE SUN DMLY
VSBL THN F ALQDS/ 8/507 58025 10038 20037

10 A.M.
Weather: Overcast cirrostratus, few distant stratocumulus
Temperature: 44F; Dew Point: 41F; Relative Humidity: 89%
Wind: E @ 10G15 kts
Sea-level pressure: 1030.4 mb; 30.43 in. Hg: falling, then more rapidly
Visibility: 20 miles, thin layer of fog
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 20 OVC 200 304/44/41/0910G15/043/ FEW SC DSNT ALQDS THN F ALQDS/
8/507 58011

1 P.M.
Weather: Overcast stratus
Temperature: 48F; Dew Point: 43F; Relative Humidity: 81%
Wind: ESE @ 7G11 kts
Sea-level pressure: 1025.7 mb; 30.29 in. Hg: falling, then more rapidly
Visibility: 20 miles, thin fog
6-hr Max temp: 49F
6-hr Min temp: 38F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 20 OVC 20 257/48/43/1107G11/029/ THN F ALQDS/ 8/6//
58047 10049 20038

————————————————————–

SUMMARY FOR SATURDAY, DECEMBER 16, 2023

TEMPERATURE (DEGREES F)
MAX…….50   NORMAL…..40
MIN…….36   NORMAL…..25
MEAN……43   NORMAL…..32

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….+11
TOTAL DEPARTURE FOR THE MONTH………………….+67 [+4.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY……………22  DEPARTURE…….-11
TOTAL HEATING UNITS FOR THE MONTH…………..419  DEPARTURE…….-68
TOTAL HEATING UNITS FOR THE SEASON…………1506  DEPARTURE……-184
TOTAL HEATING UNITS LAST SEASON TO DATE…….1426  DEPARTURE…….+80

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)……….E21 WNW  @  7:12 P.M.
VECTOR #1 (1-Sec)……….22 WNW  @  7:11 P.M.
VECTOR #2 (1-Sec)……….23 WNW  @  9:04 A.M.
DAVIS #1……………….23 W    @  7:11 P.M.
DAVIS #2 ………………23 WNW  @  7:16 P.M.
RMY #1 (Instantaneous)…..22 WNW  @  6:37 A.M.
RMY #2 (Instantaneous)…..23 WNW  @  7:16 P.M.
MERLIN…………………21 NW
RICHARDS (C5C) (Inst)……21      @  7:11 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………17 ESE  @  7:10 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..16      @  7:11 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17      @  9:04 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………16 NW   @  8:06 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 NW   @  7:00 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..16 ESE  @  7:11 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..16 NW   @  2:34 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………16      @  8:06 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….10.5 ESE [253 total miles] VECTOR #1……………..10.5
VECTOR #2……………..11.1
DAVIS #1………………10.9 NE
DAVIS #2………………10.9 NE
RMY #1………………..10.0 E
RMY #2………………..10.4 E
RICHARDS (C5C)…………10.9

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.17
TOTAL PRECIPITATION FOR THE MONTH…………..3.50 DEPARTURE…..+0.64
TOTAL PRECIPITATION FOR THE YEAR…………..54.87 DEPARTURE…..+3.54

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……-5.0
TOTAL SNOWFALL FOR THE SEASON (2023-2024)…….0.3 DEPARTURE……-7.5

————————————————————–

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/-12/0.00/0.0/121/22        18 NNW VEC1 18 NW  RMY 19
12/8  42/24/33/-2/0.00/0.0/530/96         20 S   VEC1 18 S   RMY 18
12/9  52/33/43/+9/0.00/0.0/264/48         24 S   VEC1 24 S   RMY 24
12/10 60/43/52/+18/0.66/0.0/033/06        55 SSW VEC1 54 SSW RMY 53
12/11 61/33/47/+13/1.96/0.0/038/07        69 SSW VEC1 69 SSW RMY 71
12/12 42/29/36/+2/0.00/0.0/543/99         33 WNW VEC1 32 WNW RMY 34
12/13 43/28/36/+3/0.00/0.0/470/86         36 WNW VEC1 34 WNW RMY 36
12/14 34/22/28/-5/0.00/0.0/…/..         31 SW  VEC1 31 SW  RMY 32
12/15 53/30/42/+9/0.00/0.0/…/..         31 WNW VEC1 30 WNW RMY 28
12/16 50/36/43/+11/0.00/0.0/…/..        21 ESE VEC1 22 ESE RMY 22

12/17 The low since midnight is 37F, the daily normal low is 25F

————————————————————–

DECEMBER DAILY RECORDS TO DATE

NONE…

————————————————————–

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 59 IN 1928
LOW -11 IN 1919
PRECIP 1.44 INS. IN 1915
SNOWFALL 7.0 INS. IN 1904
PEAK GUST 76e W IN 1978

TODAY’S REPORT PREPARED BY: Benjamin Turner