Tuesday, December 19, 2023

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

TUESDAY, DECEMBER 19, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0709E
SUNSET:  1614E

MUCH CALMER CONDITIONS TODAY AFTER THE POWERFUL STORM YESTERDAY….

The strong storm system of yesterday is but a memory today as much
improved weather conditions are being enjoyed. The storm total
rainfall was 2.94″. For the calendar day yesterday, 2.47″ fell,
beating the old record for the date of 1.44″ set in 1915.

Today is an ideal day for cleaning up yesterday’s mess. Sunshine
developed this morning with only some diurnal stratocumulus clouds
popping up this afternoon.

The temperature has reached the mid 40s, so it feels rather mild
out there with the sunshine and light wind.

As mentioned, the wind has become much lighter today. The average
speed for the day so far is around 10mph. The highest gust occurred
in the wee hours of the day, just after midnight and was measured at
around 25mph.

Visibility has been excellent today, holding at around 70 miles.

The maximum temperature for today is 45F degrees, this is 6 degrees
above the normal high of 39F. The minimum temperature since midnight
is 37F degrees, this is 13 degrees above the normal low of 24F.

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Today’s Observations:

7 A.M.
Weather: Overcast altocumulus/altostratus, few breaks in overcast
SSW-NNW, few stratocumulus distant all quadrants
Temperature: 38F; Dew Point: 33F; Relative Humidity: 81%
Wind: SW @ 9 kts
Sea-level pressure: 1008.2 mb; 29.77 in. Hg: rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 41F
6-hr Min temp: 38F
24-hr Precip:  1.55 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 E100 OVC 70 082/38/33/2209/977/ FEW BINOVC SSW-NNW
FEW SC DSNT ALQDS VIRGA ALQDS/ 8/57/ 51042 70155 10041 20038

10 A.M.
Weather: Clear, few stratocumulus distant all quadrants, few altocumulus
distant NNE-SE-WSW
Temperature: 42F; Dew Point: 31F; Relative Humidity: 64%
Wind: WSW @ 7 kts
Sea-level pressure: 1010.6 mb; 29.84 in. Hg: rising, then more slowly
Visibility: 70 miles
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 70 106/42/31/2507/984/ FEW SC DSNT ALQDS FEW AC DSNT
NNE-SE-WSW/ 8/550 51024

1 P.M.
Weather: Broken stratocumulus
Temperature: 43F; Dew Point: 32F; Relative Humidity: 63%
Wind: WNW @ 5 kts, wind light
Sea-level pressure: 1012.2 mb; 29.89 in. Hg: rising, then more rapidly
Visibility: 70 miles
6-hr Max temp: 45F
6-hr Min temp: 37F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E40 BKN 70 122/43/32/2905/989/ WND LGT/ 8/500 53016 10045
20037

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SUMMARY FOR MONDAY, DECEMBER 18, 2023

TEMPERATURE (DEGREES F)
MAX…….61R  NORMAL…..40
MIN…….42   NORMAL…..24
MEAN……52   NORMAL…..32

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….+20
TOTAL DEPARTURE FOR THE MONTH…………………+101 [+5.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY……………13  DEPARTURE…….-20
TOTAL HEATING UNITS FOR THE MONTH…………..451  DEPARTURE……-102
TOTAL HEATING UNITS FOR THE SEASON…………1538  DEPARTURE……-218
TOTAL HEATING UNITS LAST SEASON TO DATE…….1486  DEPARTURE…….+52

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)……….E90 SSE  @  11:33 A.M.
VECTOR #1 (1-Sec)……….95 SSE  @  11:33 A.M.
VECTOR #2 (1-Sec)……….87 SSE  @  11:33 A.M.
DAVIS #1……………….95 SSE  @  11:31 A.M.
DAVIS #2 ………………86 S    @  10:12 A.M.
RMY #1 (Instantaneous)….101 SSE  @  09:56 A.M.
RMY #2 (Instantaneous)…..96 SSE  @  10:03 A.M.
MERLIN…………………85 S
RICHARDS (C5C) (Inst)……94      @  11:33 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………61 SSE  @  11:34 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..57      @  11:29 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..60      @  11:30 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………56 SSE  @  11:34 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………55 SSE  @  11:35 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..55 SSE  @  11:29 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..57 S    @  11:43 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………56      @  11:34 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….29.4 SSE [705 total miles] VECTOR #1……………..27.6
VECTOR #2……………..29.1
DAVIS #1………………27.3 S
DAVIS #2………………27.6 S
RMY #1………………..26.3 S
RMY #2………………..28.3 S
RICHARDS (C5C)…………27.0

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..1.55 DEPARTURE…..+1.38
TOTAL PRECIPITATION FOR THE MONTH…………..6.44 DEPARTURE…..+3.23
TOTAL PRECIPITATION FOR THE YEAR…………..57.81 DEPARTURE…..+6.13

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……-5.8
TOTAL SNOWFALL FOR THE SEASON (2023-2024)…….0.3 DEPARTURE……-8.3

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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  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 55/37/46/+14/0.47/0.0/…/..        40 SSE VEC1 41 SSE RMY 41
12/18 61/42/52/+20/2.47/0.0/…/..        90 SSE VEC1 95 SSE RMY 101

12/19 The low since midnight is 37F, the daily normal low is 24F

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DECEMBER DAILY RECORDS TO DATE

12/18: RECORD MAXIMUM TEMPERATURE OF 61F;
BEATS OLD RECORD OF 59F SET IN 1928

12/18: RECORD PRECIPITATION OF 2.47 INS;
BEATS OLD RECORD OF 1.44 INS SET IN 1915

12/18: RECORD PEAK WIND GUST OF 90 MPH;
BEATS OLD RECORD OF 76e MPH SET IN 1978

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

RECORDS FOR DECEMBER 19
HIGH 59 IN 1899
LOW -1 IN 1919
PRECIP 2.06 INS. IN 1986
SNOWFALL 14.1 INS. IN 1945
PEAK GUST 68 NE IN 1986

RECORDS FOR DECEMBER 20
HIGH 61 IN 1957
LOW -16 IN 1942
PRECIP 1.69 INS. IN 1936
SNOWFALL 13.7 INS. IN 2009
PEAK GUST 75 MPH S IN 2002

TODAY’S REPORT PREPARED BY: Matt Douglas