Sunday, December 22, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, DECEMBER 22, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

MOSTLY CLOUDY AND SEASONABLE WITH LIMITED VISIBILITY
AND A SOUTHWESTERLY BREEZE….

Today we observed mostly cloudy skies with an occasional
break of sunshine. Visibility was limited to less than
35 miles due to a layer of haze. Wind was consistent,
at a speed of 10 mph from the southwest. Pressure has
begun to steadily drop since this morning; by about 5
millibars.

Milder temperatures have been observed today, being
warmer than the past 5 days. The high so far today is 40F,
which is 3 degrees above the daily normal maximum of 37F.
The low since midnight is 26F, which is 4 degrees above
the normal minimum of 22F.

Today’s Observations:

7 A.M.
Weather: Scattered altostratus, broken cirrostratus,
few offshore cumulus, sun dimly visible
Temperature: 27F; Dew Point: 23F; Wind: SW at 11 kts
Sea-level pressure: 30.31 ins. Hg, falling steadily
Visibility: 20 miles, hazy
6-hr Max temp: 29F
6-hr Min temp: 27F
24-hr Precip:  0.00 ins.
24-hr Snowfall: 0.0 ins.
Snow Depth: Trace
BHO SA 1155 120 SCT E220 BKN 20 265/27/23/2211/031/ FEW CU OFFSHR
HAZY SUN DMLY VSBL/ 8/128 56016 10029 20027

10 A.M.
Weather: Scattered altostratus, overcast cirrostratus,
few offshore cumulus, sun dimly visible
Temperature: 32F; Dew Point: 26F; Wind: SW at 10 kts,
Sea-level pressure: 30.30 ins. Hg, falling slowly
Visibility: 30 miles, hazy
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 120 SCT E220 OVC 30 261/32/26/2110/030/ FEW CU
OFFSHR HAZY SUN DMLY VSBL/ 8/128 58004

1 P.M.
Weather: Broken cirrus
Temperature: 30F; Dew Point: 22F; Wind: SW at 9 kts
Sea-level pressure: 30.20 ins. Hg, falling then more quickly
Visibility: 35 miles, hazy
6-hr Max temp: 40F
6-hr Min temp: 26F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
Snow Depth: Trace
BHO SA 1755 E220 BKN 35 228/38/23/2209/020/ HAZY/ 8/002
56033 10040 20026

SUMMARY FOR SATURDAY, DECEMBER 21, 2019

TEMPERATURE (DEGREES F)
MAX…..31   NORMAL…..37
MIN…..16   NORMAL…..22
MEAN….24   NORMAL…..30

DEPARTURE FROM 30-YEAR NORMAL………………….-6
TOTAL DEPARTURE FOR THE MONTH…………………-57 [-2.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………41  DEPARTURE……..+6
TOTAL HEATING UNITS FOR THE MONTH…………..729  DEPARTURE…….+54
TOTAL HEATING UNITS FOR THE SEASON…………1965  DEPARTURE…….+30
TOTAL HEATING UNITS LAST SEASON TO DATE…….1987  DEPARTURE…….-22

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..16 SSE AT  9:51 A.M.
AERO…………………….15 SSE AT  9:48 P.M.
ASOS…………………….16 SW  AT 11:53 P.M.
DAVIS……………………17 SSE AT  9:51 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………….12 SW  AT 11:54 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………….13 SW  AT 11:59 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………13 NNW AT 12:28 A.M.
AVERAGE WIND SPEED AND DIRECTION……………7.2 S
ASOS……………………7.9
DAVIS…………………..7.7 W  [262 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.15
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….6.06  DEPARTURE……+2.67
ASOS…………..6.51
TOTAL PRECIPITATION FOR THE YEAR……….55.14  DEPARTURE……+3.21
ASOS………….55.91

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.4
TOTAL SNOWFALL FOR THE MONTH……………19.1  DEPARTURE……+10.9
TOTAL SNOWFALL FOR THE SEASON…………..19.2  DEPARTURE…….+8.4

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

12/01  32/16/24/-13/…./5.8/011/02           33 ENE AERO 32 ENE RMY N/A
12/02  37/25/31/-5/…./2.7/000/00            52 NE  AERO 47 NE  RMY 53
12/03  30/23/27/-9/…./4.6/000/00            32 N   AERO 35 N   RMY 36
12/04  34/22/28/-7/…./0.0/000/00            23 WNW AERO 23 NNW RMY N/A
12/05  41/26/34/-1/…./0.0/343/62            33 NW  AERO 35 NW  RMY 37
12/06  33/23/28/-7/0.02/0.1/000/00            25 NW  AERO 23 NW  RMY 29
12/07  31/18/25/-9/0.00/0.0/519/94            25 NW  AERO 23 NW  RMY N/A
12/08  36/15/26/-8/0.00/0.0/…/..            31 SSW AERO 32 SSW RMY N/A
12/09  57/36/47/+13/…./0.0/…/..           53 S   AERO 52 S   RMY 54
12/10  58/37/48/+15/…./0.0/…/..           35 SW  AERO 39 SW  RMY N/A
12/11  36/23/30/-3/…./3.0/…/..            25 NW  AERO 25 NW  RMY N/A
12/12  29/17/23/-10/…./1.8/…/..           29 W   AERO 30 W   RMY 25
12/13  46/22/34/+2/…./0.0/…/..            25 SSE AERO 25 SSE RMY N/A
12/14  58/46/52/+20/…./0.0/…/..           45 S   AERO 41 S   RMY N/A
12/15  48/28/38/+6/0.00/0.0/…/..            53 W   AERO 53 W   RMY 50
12/16  30/25/28/-3/0.00/0.0/…/..            36 W   AERO 36 W   RMY N/A
12/17  35/23/29/-2/…./1.0/…/..            22 NNW AERO 21 NE  RMY 23
12/18  33/18/26/-5/…/0.0/…/..             44 WNW AERO 45 WNW RMY N/A
12/19  20/9/15/-15/…/0.0/…/..             51 W   AERO 47 W   RMY N/A
12/20  29/11/20/-10/0.00/0.0/…./..          32 W   AERO 30 W   RMY 29
12/21  31/16/24/-6/0.00/0.0/…./..           16 SSE AERO 15 SSE RMY N/A

12/22 The low since midnight is 27F, daily normal minimum is 22F

DAILY RECORDS FOR DECEMBER

12/01/19: DAILY RECORD SNOWFALL OF 5.8 INS.,
BREAKS PREVIOUS RECORD OF 2.0 INS. SET IN 1902.

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

RECORDS FOR DECEMBER 22
HIGH 63 IN 2013
LOW -5 IN 1921
PRECIP 1.52 INS. IN 1975
SNOWFALL 8.8 INS. IN 1975
PEAK GUST 62 MPH WNW IN 1998

RECORDS FOR DECEMBER 23
HIGH 62 IN 1990
LOW -1 IN 1989
PRECIP 1.70 INS. IN 1947
SNOWFALL 11.9 INS. IN 1947
PEAK GUST 67 SSE IN 2004

TODAY’S REPORT PREPARED BY: Benjamin Turner