Saturday, December 15, 2018
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 15, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME
WARM DECEMBER DAY WITH MORNING FOG…
Yesterday’s shift to southerly winds helped usher in a mass
of warm air that has swiftly brought temperatures high above
seasonal values. With the month of December starting off
cold and dry, today’s weather proved to be anomalous, with
a high temperature of 50 F reached by the 1 P.M. observation.
The Great Blue Hill spent most of its morning encapsulated
by fog before the fog lifted in the afternoon. Light rain and
drizzle were also observed this morning, with a rainfall
total of 0.06 ins. accumulated throughout this duration.
As fog cleared off the hill, a marked shift in both wind speed and
direction were observed, with magnitudes approaching zero at times,
and direction trending northwesterly; this change should
inhibit any further advective warming. By
1 P.M., skies remain near overcast with pressure readings
still trending towards relatively low values.
Today’s Observations:
7 A.M.
Weather: Light rain, light drizzle, fog
Temperature: 45F; Dew Point: 45F; Wind: WSW at 10G17 kts
Sea-level pressure: 30.18 ins. Hg, rising slowly
Visibility: 1/16 mile
6-hr Max temp: 45F
6-hr Min temp: 43F
24-hr Precip: 0.02 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 W2 X 1/16R-L-F 221/45/45/2510G17/018/
8//// 53003 6002/ 70002 10045 20043
10 A.M.
Weather: Sky obscured in dense fog
Temperature: 45F; Dew Point: 45F; Wind: WSW at 5 kts,
Wind: Light
Sea-level pressure: 30.21 ins. Hg, rising steadily
Visibility: 1/16 mile
3-hr Precip: 0.04 ins.
BHO SA 1455 W2 X 1/16F 230/45/45/2405/021/ WND LGT/ 8////
52009 6004/
1 P.M.
Weather: Broken altocumulus, overcast cirrostratus,
few lower altocumulus, hazy, sun dimly visible
Temperature: 49F; Dew Point: 45F; Wind: NW at 3 kts,
Wind: Light
Sea-level pressure: 30.14 ins. Hg, falling quickly
then more slowly
Visibility: 45 miles, 35 miles NE-E, 65 miles WNW-NW
6-hr Max temp: 50F
6-hr Min temp: 45F
6-hr Precip: 0.04 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1755 E70 BKN 200 OVC 45 208/49/45/3103/014/
FEW LWR AC BINOVC NW-NE VSBY NE-E 35 WNW-NW 65 HAZY
SUN DMLY VSBL WND LGT/ 8070/ 56022 6004/ 10050 20045
SUMMARY FOR FRIDAY, DECEMBER 14, 2018
TEMPERATURE (DEGREES F)
MAX…..46 NORMAL…..40
MIN…..28 NORMAL…..24
MEAN….37 NORMAL…..32
DEPARTURE FROM 30-YEAR NORMAL……………………+5
TOTAL DEPARTURE FOR THE MONTH…………………..-46 [-3.5 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..28 DEPARTURE………-5
TOTAL HEATING UNITS FOR THE MONTH………….477 DEPARTURE……..+45
TOTAL HEATING UNITS FOR THE SEASON………..1797 DEPARTURE…….+104
TOTAL HEATING UNITS LAST SEASON TO DATE……1386 DIFFERENCE……+411
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..28 SSW AT 10:13 P.M.
AERO…………………….28 SSW AT 10:11 P.M.
ASOS…………………….28 S AT 10:16 P.M.
DAVIS……………………26 SSW AT 10:15 P.M. RMY 29
FASTEST MILE FOR YESTERDAY………………….21 SSW AT 10:08 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….22 S AT 10:16 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………20 SSW AT 10:16 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..10.9 S
ASOS…………………..11.1
DAVIS………………….10.6 S [186 deg.]
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.02 DEPARTURE…….-0.14
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….1.06 DEPARTURE…….-1.24
ASOS…………..1.79 *
TOTAL PRECIPITATION FOR THE YEAR……….64.43 DEPARTURE……+13.79
ASOS………….67.42 *
* ASOS MONTHLY AND ANNUAL PRECIPITATION IS SUSPECT
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0 DEPARTURE……..-0.4
TOTAL SNOWFALL FOR THE MONTH…………….0.0 DEPARTURE……..-4.9
TOTAL SNOWFALL FOR THE SEASON……………7.6 DEPARTURE……..+0.1
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/…/.. 29 NW AERO 29 NW RMY 32
12/08 27/15/21/-13/0.00/0.0/…/.. 28 NW AERO 27 NW RMY 29
12/09 34/17/26/-8/0.00/0.0/…/.. 23 SSW AERO 21 SSW RMY 22
12/10 36/22/29/-4/0.00/0.0/…/.. 24 NNW AERO 23 NNW RMY 22
12/11 36/17/27/-6/0.00/0.0/…/.. 16 WSW AERO 14 WSW RMY N/A
12/12 35/18/27/-6/0.00/0.0/…/.. 30 NW AERO 29 NW RMY M
12/13 31/16/24/-8/0.00/0.0/…/.. 16 NNE AERO 12 SE RMY N/A
12/14 46/28/37/+5/0.00/0.0/…/.. 28 SSW AERO 28 SSW RMY 29
12/15 Low temp since midnight is 42F; normal low is 24F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR DECEMBER 15
HIGH 64 IN 1975
LOW 4 IN 1900, 1905, 1933
PRECIP 1.80 INS. IN 1981
SNOW 7.5 INS. IN 1951
PEAK GUST 65 MPH NW IN 1991
RECORDS FOR DECEMBER 16
HIGH 61 IN 1971
LOW -2 IN 1930
PRECIP 1.67 INS. IN 1960
SNOW 8.5 INS. IN 2007
WIND 73 MPH SSE IN 1982
TODAY’S REPORT PREPARED BY: Nate Iannuccillo
