Saturday, December 23, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 23, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

FREEZING RAIN CAUSES ICE TO GLAZE THE AREA

Freezing rain fell throughout the day, leaving Blue Hill
with 0.3 in. of ice by the 1:00 P.M. observation. A maximum
of only 31F by 1:00 P.M., but temperatures have a chance of
going above freezing later this afternoon. A total of 0.49 ins.
of precipitation has fallen so far from this storm. The wind
continued to be light today, but it began to pick up as the
pressure started to fall rapidly in the early afternoon.
Visibility today was limited to just 1/8 mile because of
fog and rain in the area.

Today’s Observations:

7 A.M.
Weather: Light freezing rain
Temperature: 25F; Dew Point: 25F; Wind: NNW at 5 kts,
Wind speed: Light
Sea-level pressure: 30.12 ins. Hg, falling, then more quickly
Visibility: 1/8 miles, fog
6-hr Max temp: 27F
6-hr Min temp: 24F
24-hr precip: 0.11 ins.
24-hr snowfall: 0.0 ins.
Snow cover: 0 ins.
Ice glaze: 0.1 ins.
BHO SA 1155 W3 X 1/8ZR-F 200/25/25/3305/012/ GLZ 0.1 IN WND LGT/
8//// 58014 MANUAL 70011 ASOS 70009 10027 20024

10 A.M.
Weather: Freezing rain
Temperature: 27F; Dew Point: 27F; Wind: NW at 6 kts,
Wind speed: Light
Sea-level pressure: 30.06 ins. Hg, falling, then more quickly
Visibility: 1/8 miles, fog
3-hr precip: 0.10 ins.
3-hr snowfall: 0.0 ins.
Ice glaze: 0.2 ins.
BHO SA 1455 W3 X 1/8ZRF 179/27/27/3206/006/ GLZ 0.2 IN WND LGT/
8//// 58021 MANUAL 60010 ASOS 60009

1 P.M.
Weather: Freezing rain
Temperature: 31F; Dew Point: 31F; Wind: NE at 7 kts
Sea-level pressure: 29.83 ins. Hg, pressure falling rapidly
Visibility: 1/8 miles, fog
6-hr Max temp: 31F
6-hr Min temp: 25F
6-hr precip: 0.38 ins.
6-hr snowfall: 0.0 ins.
Snow cover: 0 ins.
Ice glaze: 0.3 ins.
BHO SA 1755 W3 X 1/8ZRF 103/31/31/0407/983/ GLZ 0.3 IN PRESFR/
8//// 56076 MANUAL 60038 ASOS 60034 10031 20025

SUMMARY FOR FRIDAY, DECEMBER 22, 2017

TEMPERATURE (DEGREES F)
MAX…..32   NORMAL…..37
MIN…..21   NORMAL…..22
MEAN….27   NORMAL…..29

DEPARTURE FROM 30-YEAR NORMAL………………………-2
TOTAL DEPARTURE FOR THE MONTH………………………-6 [-0.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….38  DEPARTURE……….+2
TOTAL HEATING UNITS FOR THE MONTH…………714  DEPARTURE……….+5
TOTAL HEATING UNITS FOR THE SEASON……….1683  DEPARTURE……..-288
TOTAL HEATING UNITS LAST SEASON TO DATE…..1768  DIFFERENCE……..-85

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….18 E   AT 3:04 P.M.
AERO……………………17 E   AT 3:01 P.M.
ASOS……………………19 ENE AT 3:03 P.M.
DAVIS…………………..17 ENE AT 3:03 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………12 E   AT 3:00 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………15 E   AT 3:04 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..14 E   AT 3:04 P.M.
AVERAGE WIND SPEED AND DIRECTION…….. …..7.1 N
ASOS……………….. ..7.4
DAVIS………………. ..6.9 NE [46 DEG.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.11  DEPARTURE……-0.05
ASOS…………..0.09
TOTAL PRECIPITATION FOR THE MONTH……….1.65  DEPARTURE……-1.90
ASOS…………..1.72
TOTAL PRECIPITATION FOR THE YEAR……….51.49  DEPARTURE……-0.59
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…….-0.5
TOTAL SNOWFALL FOR THE MONTH…………….5.7  DEPARTURE…….-3.0
TOTAL SNOWFALL FOR THE SEASON……………5.7  DEPARTURE…….-5.6

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/+11/0.18/000/00         62 S   AERO 66 S   RMY 65
12/06 56/32/44/+9/0.54/160/29          52 S   AERO 55 S   RMY N/A
12/07 44/30/37/+3/0.00/540/98          25 WSW AERO 24 WSW RMY 25
12/08 38/28/33/-1/0.00/116/21          21 W   AERO 18 W   RMY 20
12/09 34/28/31/-3./0.70/000/00         23 NNW AERO 23 NNW RMY 23
12/10 35/27/31/-2/0.02/384/70          30 W   AERO 30 W   RMY 27
12/11 38/29/34/+1/0.00/301/55          23 W   AERO 21 W   RMY 22
12/12 43/31/37/+4/0.06/000/00          35 W   AERO 31 W   RMY N/A
12/13 31/18/25/-7/0.00/312/57          44 W   AERO 44 W   RMY 44
12/14 27/14/21/-11/T/…/..            35 WSW AERO 33 W   RMY 34
12/15 24/12/18/-14/T/…/..            25 W   AERO 23 W   RMY N/A
12/16 32/17/25/-6/0.00/…/..          33 W   AERO 35 W   RMY 36
12/17 27/14/21/-10/0.00/…/..         21 NW  AERO 21 NW  RMY 20
12/18 35/20/28/-3/T/…/..             20 SSE AERO 16 SSE RMY 20
12/19 49/34/42/+12/T/…/..            36 WNW AERO 35 SW  RMY 38
12/20 42/26/34/+4/T/…/..             41 W   AERO 40 W   RMY 45
12/21 32/23/28/-2/0.00/…/..          26 NW  AERO 24 NW  RMY 27
12/22 32/21/27/-2/…./…/..          18 E   AERO 17 E   RMY N/A

12/23 Low temp since midnight is 24F; normal low is now 21F

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

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

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

TODAY’S REPORT PREPARED BY: Lizzy Suzedell