Tuesday, December 25, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, DECEMBER 25, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

INCREASING WIND WITH GOOD VISIBILITY, AND
A FAIR WEATHER CHRISTMAS OVERALL….

Winds from the west-northwest have increased since
yesterday, with the highest gust so far being 29 mph.
Skies are mostly clear, with some scattered cumulus
in the distance. The light snow that occurred yesterday
left a trace on the ground, and 0.01 inches of liquid
in the gauge. Visibility improved from 70 miles at the
7 A.M. observation to 80 miles at 10 A.M. Pressure has
increased by almost 4 millibars since this morning, which
has contributed to the decrease of cloud cover throughout
the day. The low since midnight of 27F is 6 degrees above
the daily normal low of 21F.

Today’s Observations:

7 A.M.
Weather: Scattered cumulus
Temperature: 27F; Dew Point: 23F; Wind: NW at 10G13 kts
Sea-level pressure: 30.14 ins. Hg, rising, then more rapidly
Visibility: 70 miles
6-hr Max temp: 30F
6-hr Min temp: 27F
24-hr Precip: 0.01 ins.
24-hr snowfall: Trace
Snow depth: Trace
BHO SA 1155 50 SCT 70 208/27/23/3210G13/014/ 8/100 70001
53024 10030 20027

10 A.M.
Weather: Clear, few distant cumulus
Temperature: 31F; Dew Point: 19F; Wind: NNW at 15G22 kts
Sea-level pressure: 30.20 ins. Hg, rising rapidly
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 80 226/31/19/3315G22/020/ FEW DSNT CU ALQDS/
8/100 51018

SUMMARY FOR MONDAY, DECEMBER 24, 2018

TEMPERATURE (DEGREES F)
MAX…..34   NORMAL…..37
MIN…..27   NORMAL…..21
MEAN….31   NORMAL…..29

DEPARTURE FROM 30-YEAR NORMAL……………………+2
TOTAL DEPARTURE FOR THE MONTH…………………..+23 [+0.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..34   DEPARTURE………-2
TOTAL HEATING UNITS FOR THE MONTH………….756   DEPARTURE……..-26
TOTAL HEATING UNITS FOR THE SEASON………..2076   DEPARTURE……..+33
TOTAL HEATING UNITS LAST SEASON TO DATE……1751   DIFFERENCE……+325

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..21 W   AT  9:58 P.M.
AERO…………………….21 W   AT  7:26 P.M.
ASOS…………………….21 W   AT 11:48 P.M.
DAVIS……………………22 W   AT 11:48 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………….15 W   AT  7:32 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 W   AT  7:32 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………17 W   AT  7:32 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..6.7 W
ASOS…………………..7.0
DAVIS………………….7.3 W [277 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.01  DEPARTURE…….-0.14
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….3.13  DEPARTURE…….-0.59
ASOS…………..3.77 *
TOTAL PRECIPITATION FOR THE YEAR……….66.50  DEPARTURE……+14.30
ASOS………….69.40 *
* ASOS MONTHLY AND ANNUAL PRECIPITATION IS SUSPECT

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.5
TOTAL SNOWFALL FOR THE MONTH…………….0.1  DEPARTURE……..-9.6
TOTAL SNOWFALL FOR THE SEASON……………7.7  DEPARTURE……..-4.6

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 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/-5/0.00/0.0/546/99          29 NW  AERO 29 NW  RMY 32
12/08 27/15/21/-13/0.00/0.0/518/94         28 NW  AERO 27 NW  RMY 29
12/09 34/17/26/-8/0.00/0.0/391/71          23 SSW AERO 21 SSW RMY 22
12/10 36/22/29/-4/0.00/0.0/544/99          24 NNW AERO 23 NNW RMY 22
12/11 36/17/27/-6/0.00/0.0/543/99          16 WSW AERO 14 WSW RMY N/A
12/12 35/18/27/-6/0.00/0.0/471/86          30 NW  AERO 29 NW  RMY M
12/13 31/16/24/-8/0.00/0.0/088/16          16 NNE AERO 12 SE  RMY N/A
12/14 46/28/37/+5/0.00/0.0/399/73          28 SSW AERO 28 SSW RMY 29
12/15 49/33/43/+11/0.04/0.0/000/00         28 NE  AERO 27 NE  RMY 30
12/16 40/37/39/+8/…./0.0/…/..          38 NE  AERO 38 NE  RMY 40
12/17 37/32/35/+4/…./0.0/…/..          39 NNE AERO 37 NNE RMY N/A
12/18 34/20/27/-4/0.02/0.1/…/..          48 NW  AERO 55 NW  RMY 48
12/19 38/17/28/-2/0.00/0.0/…/..          23 WNW AERO 23 WNW RMY N/A
12/20 47/30/39/+9/0.00/0.0/…/..          23 SW  AERO 22 SW  RMY N/A
12/21 62/43/53/+23/…./0.0/…/..         60 SSE AERO 62 SSE RMY 63
12/22 54/31/43/+14/…./0.0/…/..         41 W   AERO 45 W   RMY 43
12/23 38/27/33/+4/0.00/0.0/…/..          30 WNW AERO 32 WNW RMY N/A
12/24 34/27/31/+2/0.01/T/…/..            21 W   AERO 21 W   RMY N/A

12/25 Low temp since midnight is 27F; normal low is 21F

DAILY RECORDS FOR DECEMBER 2018

12/21/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 62F,
BREAKS PREVIOUS RECORD OF 60F SET IN 1957

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: Benjamin Turner