Thursday, December 22, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, DECEMBER 22, 2016

LOW PRESSURE BRINGS TRACE OF SNOW AND PRECIP. BY 1:00PM

Only a trace of precip. was measured during the 1:00PM
observation today. Light rain began shortly before 10:00AM
but had stopped by the observation time.  Light snow started
around 10:30AM and ended before noon with no accumulation as
it melted once it hit the ground.

Temperatures remained mild, while visibility was limited to
20-35 miles today with distant fog in all directions.  Winds
were moderate and out of the S-SSE.

7 A.M.
Weather: Broken stratus, overcast altostratus
Temperature: 30F; Dew Point: 19F; Wind: SSE at 9 kts
Sea-level pressure: 30.08 ins. Hg, rising then falling
Visibility: 20 miles, distant fog in all directions
6-hr Max temp: 31F
6-hr Min temp: 29F
24-hr precip: 0.00 in.
BHO SA 1155 E54 BKN 110 OVC 20 185/30/19/1609/008/ DSNT FG ALQDS/
8/61/ 58006 10031 20029

10 A.M.
Weather: Scattered stratus fractus, broken stratus, overcast stratus
Temperature: 34F; Dew Point: 25F; Wind: SSE at 11 kts
Sea-level pressure: 30.03 ins. Hg, falling, then more slowly
Visibility: 20 miles, distant fog in all directions
3-hr precip: Trace
BHO SA 1455 24 SCT E42 BKN 54 OVC 20 169/34/25/1611/003/ DSNT FG ALQDS/
8/6// 56016 MANUAL 600//

1 P.M.
Weather: Light rain, overcast stratus
Temperature: 37F; Dew Point: 30F; Wind: S at 8 kts
Sea-level pressure: 29.92 ins. Hg, falling, then more quickly
Visibility: 35 miles, except 20 miles SSW-NW and 10 miles NW-NE,
distant fog in all directions
6-hr Max temp: 37F
6-hr Min temp: 30F
6-hr precip: Trace
6-hr snowfall: Trace
BHO SA 1755 E49 OVC 35R- 132/37/30/1708/992/ VSBY SSW-NW 20 AND NW-NE 10
DSNT FG ALQDS/ 8/6// 58037 MANUAL 600// ASOS 60001 10037 20030

SUMMARY FOR WEDNESDAY, DECEMBER 21, 2016

TEMPERATURE (DEGREES F)
MAX…..40   NORMAL…..37
MIN…..25   NORMAL…..22
MEAN….33   NORMAL…..30

DEPARTURE FROM 30-YEAR NORMAL……………………+3
TOTAL DEPARTURE FOR THE MONTH…………………..-36 [-1.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..32   DEPARTURE……….-3
TOTAL HEATING UNITS FOR THE MONTH………….707   DEPARTURE………+33
TOTAL HEATING UNITS FOR THE SEASON………..1737   DEPARTURE……..-198
TOTAL HEATING UNITS LAST SEASON TO DATE……1446   DIFFERENCE…….+291

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….28 SSE AT 12:18 A.M.
ASOS……………………30 SSW AT 12:18 A.M.
DAVIS…………………..29 SSE AT 12:18 A.M. RMY 30
FASTEST MILE FOR YESTERDAY…………………21 SSE AT 12:17 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………22 SW  AT 12:19 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..21 S   AT 12:19 A.M.
AVERAGE WIND SPEED AND DIRECTION………….11.1 SSW
ASOS………………….10.9
DAVIS………………….9.8 SSW [210 Deg.] *last of multiple occurrences

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……….1.49  DEPARTURE……-1.90
ASOS…………..1.64
TOTAL PRECIPITATION FOR THE YEAR……….38.46  DEPARTURE…..-13.46
ASOS………….39.07

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.4
TOTAL SNOWFALL FOR THE MONTH…………….6.0  DEPARTURE…….-2.2
TOTAL SNOWFALL FOR THE SEASON……………6.0  DEPARTURE…….-4.8

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

12/1  55/39/47/+10/0.20/0.0/385/69          36 W   AERO 37 W   RMY 36
12/2  48/34/41/+5/0.00/0.0/535/96           32 W   AERO 32 W   RMY N/A
13/3  44/31/38/+2/0.00/0.0/445/80           37 WNW AERO 39 WNW RMY 40
12/4  39/27/33/-2/0.00/0.0/355/64           25 NW  AERO 25 NW  RMY N/A
12/5  36/27/32/-3/0.13/0.4/000/00           26 W   AERO 25 W   RMY 29
12/6  42/30/36/+1/0.00/0.0/392/71           22 W   AERO 21 W   RMY N/A
12/7  39/34/37/+3/0.10/0.0/000/00           21 E   AERO 21 E   RMY N/A
12/8  40/29/35/+1/0.00/0.0/033/06           30 W   AERO 31 W   RMY 33
12/9  35/21/28/-6/0.00/0.0/549/100          35 W   AERO 36 WNW RMY 34
12/10 27/17/22/-11/0.00/0.0/544/99          26 WNW AERO 27 WNW RMY 29
12/11 33/16/25/-8/0.06/0.4/411/75           17 SSW AERO 15 SW  RMY N/A
12/12 41/27/34/+1/0.35/0.9/038/07           29 ESE AERO 29 SE  RMY 30
12/13 41/30/36/+4/0.00/0.0/…/..           25 WSW AERO 25 W   RMY 27
12/14 40/26/33/+1/0.00/0.0/…/..           30 WNW AERO 31 WNW RMY N/A
12/15 29/13/21/-11/T/T/…/..               50 W   AERO 62 W   RMY 56
12/16 18/01/10/-21/0.00/0.0/…/..          39 WNW AERO 51 WNW RMY N/A
12/17 36/18/27/-4/0.60/4.3/…/..           25 SSW AERO 28 SSW RMY N/A
12/18 55/30/43/+12/0.05/0.0/…/..          47 WSW AERO 53 S   RMY 53
12/19 30/17/24/-6/0.00/0.0/…/..           26 WNW*AERO 28 NW  RMY 26
12/20 32/13/23/-7/0.00/0.0/…/..           28 SSE AERO 29 SSW RMY N/A
12/21 40/25/33/+3/0.00/0.0/…/..           28 SSE AERO 28 SSW RMY 30

12/22 Low temp since midnight is 29F; normal low is now 22F

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

RECORDS FOR DECEMBER 22
HIGH 62 IN 1994
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: Cecilia Borries-Strigle