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

SATURDAY, DECEMBER 25, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0712E
SUNSET:  1617E

...MERRY CHRISTMAS FROM BLUE HILL...
LIGHT ICING THIS MORNING TRANSITIONS TO A CHILLY RAIN....

A phenomenon that isn't too common here at Blue Hill occurred
this morning. Before the light precipitation moved in, the hill
was in the clouds with temperatures in the upper 20s. This
created freezing fog which did begin to accrue some rime ice on
some surfaces before the light freezing rain started to fall.

Light freezing rain continued for about 4 hours before the
temperature climbed just above freezing allowing for a transition
to plain rain. Light rain has continued into the early afternoon
hours. Total liquid equivalent as measured at 1 P.M. is 0.16".

The wind has however backed from the east to the north-northeast
over the last couple of hours, as such the temperature has slipped
back to just under 32F degrees after a maximum temperature of 34F
was reached. So far no additional icing has occurred, but we'll be
watching for it as the afternoon progresses.

The wind has been very much on the light side only mustering a
peak gust of 17mph so far. The average speed for the day has only
been around 7mph.

The high so far today is 34F, which is 4 degrees below the normal
max of 38F. The low since midnight is 25F, which is 3 degrees above
the normal low of 22F.

Merry Christmas, and best wishes to you and yours!  

--------------------------------------------------------------

Today's Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200ft
Temperature: 28F; Dew Point: 28F; Relative Humidity: 100%
Wind: S @ 4 kts, wind light
Sea-level pressure: 1006.9 mb; 29.73 in. Hg: falling, then more slowly
Visibility: 1/8 mile, freezing fog
6-hr Max temp: 29F
6-hr Min temp: 26F
24-hr Precip:  Trace
24-hr Snowfall: 0.1 ins.
Snow Depth: Trace
BHO SA 1155 X W2 1/8ZF 069/28/28/1704/973/ ZR-B33E55 WND LGT
NEW SNW PST 24 HRS 0.1/ 8//// 4/000 56032 6000/ 70001 10029 20026

10 A.M.
Weather: Sky obscured, vertical visibility 200ft, light freezing rain  
Temperature: 31F; Dew Point: 31F; Relative Humidity: 100%
Wind: E @ 7 kts  
Sea-level pressure: 1004.2 mb; 29.65 in Hg; falling, then more rapidly
Visibility: 1/8 mile, freezing fog
3-hr Precip:  0.04 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 X W2 1/8ZR-ZF 042/31/31/1007/965/ THN GLZ ALL SFCS/ 8////
58027 6004/

1 P.M.
Weather: Sky obscured, vertical visibility 200ft, light rain
Temperature: 32F, Dew point: 32F; Relative Humidity: 100%
Wind: NNE @ 8kts
Sea-level pressure: 1000.1 mb; 29.53 in Hg; falling, then more slowly
Visibility: 1/8 mile, fog
6-hr Max temp: 34F
6-hr Min temp: 28F
6-hr Precip:   0.16 ins.
6-hr Snowfall: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 X W2 1/8R-F 001/32/32/0208/953/ 8//// 56041 6016/ 10034 20028


SUMMARY FOR FRIDAY, DECEMBER 24, 2021

TEMPERATURE (DEGREES F)
MAX.......25     NORMAL.....38
MIN.......20     NORMAL.....23
MEAN......23     NORMAL.....30

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL............... -7
TOTAL DEPARTURE FOR THE MONTH...........................+87 [+3.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY...............42  DEPARTURE........+7
TOTAL HEATING UNITS FOR THE MONTH..............669  DEPARTURE.......-88
TOTAL HEATING UNITS FOR THE SEASON............1676  DEPARTURE......-285
TOTAL HEATING UNITS LAST SEASON TO DATE.......1718 DEPARTURE........-42

PEAK WIND GUST (MPH):
                     Official (1-Sec AVG).......14 N   @ 12:06 A.M.
                     AEROVANE...................13 N   @ 12:09 A.M.
                     VECTOR #2 (Instantaneous)..14     @ 12:06 A.M.
                     DAVIS #2 ..................15 S   @  6:04 A.M.
                     RMY #2 (Instantaneous).....14 N   @ 12:05 A.M.
                     ASOS...........OUT OF SERVICE D/T RENOVATIONS
                     VECTOR #1......OUT OF SERVICE D/T RENOVATIONS
                     DAVIS #1.......OUT OF SERVICE D/T RENOVATIONS
                     RMY #1.........OUT OF SERVICE D/T RENOVATIONS  
                     MERLIN.........OUT OF SERVICE D/T RENOVATIONS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL.................. 8 NW  @ 10:26 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE..............10     @ 10:27 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............10 NNW @ 10:27 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE.................10 NW  @ 10:27 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE.......OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE...OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE..OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE RMY #1 AVERAGE.....OUT OF SERVICE D/T RENOVATIONS

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL..... 2.8 WNW  [068 total miles]
                     VECTOR #2............... 4.0
                     DAVIS #2................ 3.3 W
                     RMY #2.................. 3.9 WSW
                     RMY #1..............OUT OF SERVICE D/T RENOVATIONS
                     ASOS................OUT OF SERVICE D/T RENOVATIONS
                     VECTOR #1...........OUT OF SERVICE D/T RENOVATIONS
                     DAVIS #1............OUT OF SERVICE D/T RENOVATIONS   

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.......0.01  DEPARTURE.....-0.16
TOTAL PRECIPITATION FOR THE MONTH.............2.06  DEPARTURE.....-2.20
TOTAL PRECIPITATION FOR THE YEAR.............58.83  DEPARTURE.....+6.36

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M.............0.1  DEPARTURE......-0.4
TOTAL SNOWFALL FOR THE MONTH...................1.5  DEPARTURE......-7.5
TOTAL SNOWFALL FOR THE SEASON (2021-2022)......2.5  DEPARTURE......-9.0


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   44/30/37/0.00/0.0/263/47          35 W   AERO 35 W   RMY 34      
12/02   58/35/47/10/T/0.0/106/19          56 WNW AERO 59 WNW RMY 62 TSTM
12/03   41/28/35/-1/0.00/0.0/512/92       46 NW  AERO 44 NW  RMY 46
12/04   39/25/32/-4/0.00/0.0/233/42       25 SW  AERO 23 SW  RMY 26
12/05   45/32/39/+3/0.00/0.0/460/83       25 SE  AERO 25 SE  RMY 25
12/06   59/37/48/+13/0.34/0.0/077/14      59 WNW AERO 59 NW  RMY 60
12/07   40/29/35/0/T/0.0/436/79           47 WNW AERO 36 WNW RMY 48
12/08   34/25/30/-5/0.05/0.6/000/00       26 NNE AERO 25 NE  RMY 26
12/09   35/20/28/-6/0.05/0.6/319/58       32 NW  AERO 30 NW  RMY 33
12/10   43/27/35/+1/0.00/0.0/000/00       21 SE  AERO 20 SE  RMY 21
12/11   62/37/50/+16/0.34/0.0/000/00      57 SSW AERO 59 SSW RMY 58
12/12   58/36/47/+13/0.05/0.0/416/76      55 WNW AERO 55 WNW RMY 58
12/13   50/35/43/+10/0.00/0.0/224/41      32 WSW AERO 33 WSW RMY 33
12/14   50/33/42/+9/0.00/0.0/442/81       31 WSW AERO 30 WSW RMY 32
12/15   42/28/35/+2/T/0.0/153/28          35 SSE AERO 35 SSE RMY 36
12/16   58/42/50/+18/0.21/0.0/016/03      35 SW  AERO 37 SW  RMY 38
12/17   56/39/48/+16/0.00/0.0/518/95      43 WNW AERO 41 WNW RMY 46
12/18   39/31/35/+3/0.52/0.2/000/00       21 NNW AERO 20 NNW RMY 20
12/19   39/20/30/-2/0.39/0.0/.../..       35 NNW AERO 37 NNW RMY 36
12/20   32/15/24/-7/0.00/0.0/.../..       29 SSW AERO 30 SSW RMY 30
12/21   40/27/34/+3/0.00/0.0/.../..       31 SW  AERO 32 SW  RMY 33
12/22   45/30/38/+7/0.10/0.0/.../..       47 NW  AERO 45 NW  RMY 47
12/23   30/21/26/-5/0.00/0.0/.../..       39 NW  AERO 38 NW  RMY 37
12/24   25/20/23/-7/0.01/0.1/.../..       14 N   AERO 13 N   RMY 14

12/25 The low since midnight is 25F, the daily normal low is 22F

DAILY RECORDS FOR DECEMBER 2021

12/16/21: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 42F
          TIES PREVIOUS RECORD OF 42F SET IN 1982


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 2.15 INS. IN 2020
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: Matt Douglas