Monday, December 24, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 24, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

LIGHT WIND AND FREEZING TEMPERATURES WITH
SNOW DEVELOPING IN THE AFTERNOON….

Westerly airflow persisted overnight, but remained light
throughout the day. Wind has remained at or below 10 mph
since midnight, with an average speed around 5 mph. The
highest visibility seen so far was 40 miles at the 7 A.M.
and 10 A.M. observations. Due to a distant fog and light
snow beginning shortly before 1 P.M., only 5 miles could
be seen. The snow left only a trace in the gauge at the
1 P.M. observation. The high temperature so far today is
38F, a degree above the daily normal of 37F. The minimum
since this morning of 27F is 6 degrees above the daily
normal low of 21F.

Today’s Observations:

7 A.M.
Weather: Overcast altostratus
Temperature: 28F; Dew Point: 21F; Wind: WSW at 4 kts,
Wind: Light
Sea-level pressure: 30.03 ins. Hg, falling steadily
Visibility: 40 miles, thin smoke layer in all directions
6-hr Max temp: 28F
6-hr Min temp: 27F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 E110 OVC 40 171/28/21/2504/003/ THN K LYR ALQDS
WND LGT/ 8/01/ 56005 10028 20027

10 A.M.
Weather: Broken cirrostratus
Temperature: 33F; Dew Point: 25F; Wind: W at 5 kts,
Wind: Light
Sea-level pressure: 30.05 ins. Hg, rising then falling
Visibility: 40 miles, distant haze
3-hr Precip: 0.00 ins.
BHO SA 1455 E250 BKN 40 175/33/25/2605/005/ DSNT HZ ALQDS WND
LGT/ 8/007 50004

1 P.M.
Weather: Light snow and fog
Temperature: 33F; Dew Point: 29F; Wind: SW at 4 kts,
Wind: Light
Sea-level pressure: 29.98 ins. Hg, falling, then more rapidly
Visibility: 5 miles, fog
6-hr Max temp: 34F
6-hr Min temp: 27F
6-hr Precip: Trace
6-hr snowfall: Trace
Snow depth: 0 ins.
BHO SA 1755 E110 OVC 5S-F 153/33/29/2404/998/ S-B35 WND LGT/
8/02/ 600// 56022 10034 20027

SUMMARY FOR SUNDAY, DECEMBER 23, 2018

TEMPERATURE (DEGREES F)
MAX…..38   NORMAL…..37
MIN…..27   NORMAL…..21
MEAN….33   NORMAL…..29

DEPARTURE FROM 30-YEAR NORMAL……………………+4
TOTAL DEPARTURE FOR THE MONTH…………………..+21 [+0.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..32   DEPARTURE………-4
TOTAL HEATING UNITS FOR THE MONTH………….722   DEPARTURE……..-23
TOTAL HEATING UNITS FOR THE SEASON………..2042   DEPARTURE……..+32
TOTAL HEATING UNITS LAST SEASON TO DATE……1713   DIFFERENCE……+324

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..30 WNW AT 12:17 A.M.
AERO…………………….32 WNW AT 12:16 A.M.
ASOS…………………….31 W   AT 12:22 A.M.
DAVIS……………………31 NW  AT 12:21 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………….24 WNW AT 12:08 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….22 WNW AT 12:10 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………23 WNW AT 12:10 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..11.8 WNW
ASOS…………………..11.4
DAVIS………………….12.4 WNW [295 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……….3.12  DEPARTURE…….-0.59
ASOS…………..3.76 *
TOTAL PRECIPITATION FOR THE YEAR……….66.49  DEPARTURE……+14.44
ASOS………….69.39 *
* ASOS MONTHLY AND ANNUAL PRECIPITATION IS SUSPECT

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.5
TOTAL SNOWFALL FOR THE MONTH…………….0.1  DEPARTURE……..-9.1
TOTAL SNOWFALL FOR THE SEASON……………7.7  DEPARTURE……..-4.1

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 41/28/35/-2/0.00/0.0/391/70          20 NNW AERO 18 NNW RMY N/A
12/02 52/35/44/+8/1.04/0.0/000/00          28 ESE AERO 25 ESE RMY 27
12/03 54/38/46/+10/0.00/0.0/178/32         35 W   AERO 35 W   RMY 38
12/04 38/23/31/-4/0.00/0.0/516/93          30 WNW AERO 31 WNW RMY 33
12/05 33/18/26/-9/0.00/0.0/432/78          16 NNW AERO 15 NNW RMY N/A
12/06 37/24/31/-4/0.00/0.0/354/64          29 W   AERO 28 W   RMY 30
12/07 37/21/29/-5/0.00/0.0/546/99          29 NW  AERO 29 NW  RMY 32
12/08 27/15/21/-13/0.00/0.0/518/94         28 NW  AERO 27 NW  RMY 29
12/09 34/17/26/-8/0.00/0.0/391/71          23 SSW AERO 21 SSW RMY 22
12/10 36/22/29/-4/0.00/0.0/544/99          24 NNW AERO 23 NNW RMY 22
12/11 36/17/27/-6/0.00/0.0/543/99          16 WSW AERO 14 WSW RMY N/A
12/12 35/18/27/-6/0.00/0.0/471/86          30 NW  AERO 29 NW  RMY M
12/13 31/16/24/-8/0.00/0.0/088/16          16 NNE AERO 12 SE  RMY N/A
12/14 46/28/37/+5/0.00/0.0/399/73          28 SSW AERO 28 SSW RMY 29
12/15 49/33/43/+11/0.04/0.0/000/00         28 NE  AERO 27 NE  RMY 30
12/16 40/37/39/+8/…./0.0/…/..          38 NE  AERO 38 NE  RMY 40
12/17 37/32/35/+4/…./0.0/…/..          39 NNE AERO 37 NNE RMY N/A
12/18 34/20/27/-4/0.02/0.1/…/..          48 NW  AERO 55 NW  RMY 48
12/19 38/17/28/-2/0.00/0.0/…/..          23 WNW AERO 23 WNW RMY N/A
12/20 47/30/39/+9/0.00/0.0/…/..         23 SW  AERO 22 SW  RMY N/A
12/21 62/43/53/+23/…./0.0/…/..         60 SSE AERO 62 SSE RMY 63
12/22 54/31/43/+14/…./0.0/…/..         41 W   AERO 45 W   RMY 43
12/23 38/27/33/+4/0.00/0.0/…/..          30 WNW AERO 32 WNW RMY N/A

12/24 Low temp since midnight is 27F; normal low is 21F

DAILY RECORDS FOR DECEMBER 2018

12/21/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 62F,
BREAKS PREVIOUS RECORD OF 60F SET IN 1957

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