Tuesday, December 24, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, DECEMBER 24, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

A FAIR WEATHER DAY WITH A COOL NORTHERLY
BREEZE….

Today we observed partly cloudy skies with abundant
sunshine. Visibility was excellent at 80 miles on
average, with 85 miles being seen at 10 A.M. and 1
P.M. Wind was consistent at a speed of 10 mph from
the north. Humidity dropped to 40% by the 1 P.M.
observation.

The high so far today is 42F, which is 6 degrees above
the daily normal maximum of 36F. The low since midnight
is 33F, which is 12 degrees above the normal minimum
of 21F.

Today’s Observations:

7 A.M.
Weather: Scattered cirrus
Temperature: 34F; Dew Point: 23F; Wind: NW at 13G16 kts
Sea-level pressure: 30.06 ins. Hg, rising steadily
Visibility: 75 miles
6-hr Max temp: 42F
6-hr Min temp: 34F
24-hr Precip:  0.00 ins.
24-hr Snowfall: 0.0 ins.
Snow Depth: Trace
BHO SA 1155 250 SCT 75 171/34/23/3213G18/006/ 8/002 53031
10042 20034

10 A.M.
Weather: Broken cirrus
Temperature: 36F; Dew Point: 20F; Wind: NNW at 11G18 kts,
Sea-level pressure: 30.15 ins. Hg, rising steadily
Visibility: 85 miles
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E250 BKN 85 200/36/20/3311G18/015/ 8/002 53029

1 P.M.
Weather: Scattered cirrus
Temperature: 42F; Dew Point: 19F; Wind: N at 8 kts
Sea-level pressure: 30.12 ins. Hg, falling steadily
Visibility: 85 miles
6-hr Max temp: 42F
6-hr Min temp: 33F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
Snow Depth: Trace
BHO SA 1755 250 SCT 85 190/42/19/3508/012/ 8/002 56010 10042
20033

SUMMARY FOR MONDAY, DECEMBER 23, 2019

TEMPERATURE (DEGREES F)
MAX…..54   NORMAL…..37
MIN…..33   NORMAL…..21
MEAN….44   NORMAL…..29

DEPARTURE FROM 30-YEAR NORMAL…………………+15
TOTAL DEPARTURE FOR THE MONTH…………………-38 [-1.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………21  DEPARTURE…….-15
TOTAL HEATING UNITS FOR THE MONTH…………..781  DEPARTURE…….+36
TOTAL HEATING UNITS FOR THE SEASON…………2018  DEPARTURE…….+11
TOTAL HEATING UNITS LAST SEASON TO DATE…….2041  DEPARTURE…….-23

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..30 WSW AT  8:47 P.M.
AERO…………………….30 SW  AT  6:08 P.M.
ASOS…………………….31 W   AT  8:48 P.M.
DAVIS……………………32 SW  AT  7:35 P.M. RMY 30
FASTEST MILE FOR YESTERDAY………………….25 SW  AT  5:52 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….22 W   AT  8:57 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………24 W   AT  8:55 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..14.1 WSW
ASOS…………………..13.9
DAVIS………………….13.9 WSW  [243 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.16
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….6.06  DEPARTURE……+2.35
ASOS…………..6.51
TOTAL PRECIPITATION FOR THE YEAR……….55.14  DEPARTURE……+2.89
ASOS………….55.91

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.5
TOTAL SNOWFALL FOR THE MONTH……………19.1  DEPARTURE…….+9.9
TOTAL SNOWFALL FOR THE SEASON…………..19.2  DEPARTURE…….+7.4

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  40/26/33/+4/0.00/0.0/…./..           23 SW  AERO 21 SW  RMY 23
12/23  54/33/44/+15/0.00/0.0/…./..          30 WSW AERO 30 SW  RMY 30

12/24 The low since midnight is 33F, daily normal minimum is 21F

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 24
HIGH 67 IN 2015
LOW -6 IN 1943
PRECIP 2.21 INS. IN 1994
SNOWFALL 12.3 INS. IN 1961
PEAK GUST 79e MPH SE IN 1941

RECORDS FOR DECEMBER 25
HIGH 64 IN 2015
LOW -11 IN 1980
PRECIP 1.37 INS. IN 2002
SNOWFALL 8.5 INS. IN 2002
PEAK GUST 80 MPH NW IN 1971

TODAY’S REPORT PREPARED BY: Benjamin Turner