Monday, December 25, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 25, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

MERRY CHRISTMAS FROM BLUE HILL OBSERVATORY…

This Christmas morning started wet and slushy with
a wintery mix of rain, sleet and freezing rain
falling until around 8:45 AM. Also at this time
the wind shifted from the northeast to northwest,
this caused temperatures to drop and snow began
to fall. We measured 2.3 inches measured by
10:00 A.M. EST. Winds began strong this morning
with a peak gust of 36 kts (41 MPH) by 11:00 AM.
Skies have remained overcast and visibility was
limited to less than a half mile during each
observation due to fog and then blowing snow.

Today’s Observations:

7 A.M.
Weather: Mixture of light rain and sleet, fog
Temperature: 33F; Dew Point: 33F; Wind: NE at 15G26 kts,
Peak wind: 32 kts (37 MPH) at 06:07 A.M.
Sea-level pressure: 29.54 ins. Hg, falling rapidly
Visibility: 1/4 mile
6-hr Max temp: 35F
6-hr Min temp: 33F
24-hr precip: 0.31 ins.
24-hr snowfall: 0.2 ins.
Snow cover: 0 ins.
BHO SA 1155 W3 X 1/4L-IPF 004/33/33/0415G26/954/ NEW SNW PST 24
HRS 0.2 INS PRESFR PK WND 0632/07/ 8//// 58075 MANUAL 70031 ASOS
70030 10035 20033

10 A.M.
Weather: Moderate snow and fog
Temperature: 22F; Dew Point: 22F; Wind: WNW at 22G32 kts,
Peak wind: 36 kts (41 MPH) at 09:37 A.M.
Sea-level pressure: 29.54 ins. Hg, falling, then rising
Visibility: 1/8 mile
3-hr precip: 0.27 ins.
3-hr snowfall: 2.3 ins.
BHO SA 1455 W3 X 1/8SF 003/22/22/3022G32/954/ SNOINCR 1/2 NEW SNW PST 3 HRS
2.3 INS PK WND 3036/37/ 8//// 55003 MANUAL 6027/ ASOS 60035

SUMMARY FOR SUNDAY, DECEMBER 24, 2017

TEMPERATURE (DEGREES F)
MAX…..35   NORMAL…..37
MIN…..29   NORMAL…..21
MEAN….32   NORMAL…..29

DEPARTURE FROM 30-YEAR NORMAL………………………+3
TOTAL DEPARTURE FOR THE MONTH………………………-2 [-0.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….33  DEPARTURE……….-3
TOTAL HEATING UNITS FOR THE MONTH…………782  DEPARTURE………..0
TOTAL HEATING UNITS FOR THE SEASON……….1751  DEPARTURE……..-292
TOTAL HEATING UNITS LAST SEASON TO DATE…..1823  DIFFERENCE……..-72

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….30 ENE AT 9:11 P.M.
AERO……………………25 ENE AT 9:42 P.M.
ASOS……………………29 E   AT 9:11 P.M.
DAVIS…………………..27 E   AT 9:10 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………21 ENE AT 9:12 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………21 E   AT 9:47 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..21 E   AT 9:15 P.M.
AVERAGE WIND SPEED AND DIRECTION………….10.9
ASOS………………….11.5
DAVIS…………………10.4 N [2 DEG.]

*Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.31  DEPARTURE……+0.16
ASOS…………..0.30
TOTAL PRECIPITATION FOR THE MONTH……….2.53  DEPARTURE……-1.33
ASOS…………..2.59
TOTAL PRECIPITATION FOR THE YEAR……….52.37  DEPARTURE……-0.02
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……….0.2  DEPARTURE…….-0.3
TOTAL SNOWFALL FOR THE MONTH…………….5.9  DEPARTURE…….-3.8
TOTAL SNOWFALL FOR THE SEASON……………5.9  DEPARTURE…….-6.4

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 36/24/30/+1/…./…/..          31 WSW AERO 28 WSW RMY 31
12/24 35/29/32/+3/…./…/..          30 ENE AERO 25 ENE RMY N/A

12/25 Low temp since midnight is 21F; 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 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

RECORDS FOR DECEMBER 26
HIGH 58 IN 1973,1982
LOW -12 IN 1980
PRECIP 3.64 INS. IN 1969
SNOWFALL 17.5 INS. IN 1909
PEAK GUST 84 MPH SSE IN 1957

TODAY’S REPORT PREPARED BY: Kaitlin Ann Geagan