Tuesday, December 12, 2017
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, DECEMBER 12, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME
AS PRESSURE DROPS LIGHT RAIN BEGINS IN LATE
MORNING AND CONTINUES INTO AFTERNOON…
Pressure began dropping late yesterday and
continued to drop all day. With the low pressure
the sky covered with stratus clouds and a light
rain began just before 10:00 AM. The rain has
begun to melt the snow cover from the ground
allowing for fog to form around the Observatory
limiting visibility to 10 miles at 1:00 PM. So
far we measured 0.02 inches of rain by 1:00 PM.
Winds have been moderate today and from the ESE.
Today’s Observations:
7 A.M.
Weather: Overcast stratus
Temperature: 34F; Dew Point: 28F; Wind: ESE at 14 kts
Sea-level pressure: 29.82 ins. Hg, falling, then more quickly
Visibility: 40 miles, distant fog in all directions
6-hr Max temp: 34F
6-hr Min temp: 31F
24-hr precip: Trace
24-hr snowfall: Trace
Snow cover: 2 ins.
BHO SA 1155 E46 OVC 40 099/34/28/1214/982/ NEW SNW PST 24 HRS
TRACE DSNT FG ALQDS/ 8/6// 4/002 58031 10034 20031
10 A.M.
Weather: Light rain, overcast nimbostratus
Temperature: 37F; Dew Point: 31F; Wind: ESE at 12 kts
Sea-level pressure: 29.73 ins. Hg, falling, then more quickly
Visibility: 35 miles, distant fog in all directions
3-hr precip: Trace
3-hr snowfall: 0.0 ins.
BHO SA 1455 E40 OVC 35R- 068/37/31/1212/973/ DSNT FG ALQDS/
8/6// MANUAL 600// 58031
1 P.M.
Weather: Light rain, overcast nimbostratus
Temperature: 40F; Dew Point: 37F; Wind: ESE at 14G22 kts
Sea-level pressure: 29.54 ins. Hg, falling, then more quickly
Visibility: 10 miles, distant fog in all directions
6-hr Max temp: 41F
6-hr Min temp: 34F
6-hr precip: 0.02 ins.
6-hr snowfall: 0.0 ins.
Snow cover: 1 in.
BHO SA 1755 E30 OVC 10R- 002/40/37/1214G22/954/ DSNT FG ALQDS/
8/6// 4/001 MANUAL 6002/ ASOS 60002 56066 10041 20034
SUMMARY FOR MONDAY, DECEMBER 11, 2017
TEMPERATURE (DEGREES F)
MAX…..38 NORMAL…..41
MIN…..29 NORMAL…..25
MEAN….34 NORMAL…..33
DEPARTURE FROM 30-YEAR NORMAL………………………+1
TOTAL DEPARTURE FOR THE MONTH……………………..+28 [+2.5 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….31 DEPARTURE……….-1
TOTAL HEATING UNITS FOR THE MONTH…………305 DEPARTURE………-28
TOTAL HEATING UNITS FOR THE SEASON……….1274 DEPARTURE……..-321
TOTAL HEATING UNITS LAST SEASON TO DATE…..1371 DIFFERENCE……..-97
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….23 W AT 12:47 P.M.
AERO……………………21 W AT 12:49 P.M.
ASOS……………………22 W AT 12:50 P.M.
DAVIS…………………..22 SW AT 07:54 A.M. RMY 22
FASTEST MILE FOR YESTERDAY…………………17 W AT 12:49 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………16 W AT 12:51 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..17 W AT 12:51 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..8.3 SW
ASOS…………………..8.4
DAVIS………………….8.1 W [259 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……….1.48 DEPARTURE……-0.33
ASOS…………..1.57
TOTAL PRECIPITATION FOR THE YEAR……….51.32 DEPARTURE……+0.98
ASOS……………N/A **
** ASOS annual total not available due to erroneous readings
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0 DEPARTURE…….-0.4
TOTAL SNOWFALL FOR THE MONTH…………….5.6 DEPARTURE…….+2.0
TOTAL SNOWFALL FOR THE SEASON……………5.6 DEPARTURE…….-0.6
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 50/35/43/+6/0.04/262/47 28 NW AERO 29 NW RMY 30
12/02 42/29/36/0/0.00/033/06 20 NNW AERO 18 NNW RMY N/A
12/03 42/32/37/+1/0.00/172/31 14 N AERO 10 N RMY N/A
12/04 43/32/38/+3/0.00/522/94 16 E AERO 14 E RMY N/A
12/05 58/34/46/+11/…/000/00 62 S AERO 66 S RMY 65
12/06 56/32/44/+9/…/160/29 52 S AERO 55 S RMY N/A
12/07 44/30/37/+3/0.00/522/98 25 WSW AERO 24 WSW RMY 25
12/08 38/28/33/-1/0.00/…/.. 21 W AERO 18 W RMY 20
12/09 34/28/31/-3./…./…/.. 23 NNW AERO 23 NNW RMY 23
12/10 35/27/31/-2/…./…/.. 30 W AERO 30 W RMY 27
12/11 38/29/34/+1/0.00/…/.. 23 W AERO 21 W RMY 22
12/12 Low temp since midnight is 31F; normal low is now 25F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR DECEMBER 12
HIGH 67 IN 1979
LOW -3 IN 1988
PRECIP 3.94 INS. IN 1992
SNOWFALL 20.3 INS. IN 1960
PEAK GUST 75 MPH SSE IN 2008
RECORDS FOR DECEMBER 13
HIGH 60 IN 1984
LOW 0 IN 1893
PRECIP 1.45 INS. IN 1983
SNOWFALL 9.2 INS. IN 2007
PEAK GUST 81e WNW IN 1976
TODAY’S REPORT PREPARED BY: Kaitlin Geagan
