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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, DECEMBER 21, 2018 
ALL TIMES ARE IN EASTERN STANDARD TIME

WARM WET DAY HITS RECORD HIGH TEMPERATURES
IN THE MIDST OF SUSTAINED RAINFALL...

The past 48 hours witnessed sustained southerly winds that have brought 
warm air and unseasonably high temperatures for both yesterday and today.
This produced readings significantly higher than December averages for 
yesterday, and already breaking the daily record high of 60 F for today,
with a high temperature of 61 F recorded at 1 P.M..
A noteworthy low pressure system has accompanied the warm air, with 
this coastal storm bringing significant rainfall to the Blue Hills 
this morning, with no signs of stopping at the time of the 1 P.M. 
observation, with heavy rain battering the landscape.  Wind speeds, 
which were sustained but relatively modest throughout yesterday, have 
been replaced by near gale force and gale force winds throughout 
the observation period today.  Already, a peak wind speed of 49 KTS (56 MPH) 
has been reached this morning.  Pressure readings have plummeted throughout 
the forecast period and continue to do so through the 1 P.M. observation.


Today's Observations:

7 A.M.
Weather: Light fog, light rain
Temperature: 54F; Dew Point: 54F; Wind: SW at 24G33 kts 
Peak wind: 33 KTS (38 MPH) SW at 6:58 P.M.    
Sea-level pressure: 29.74 ins. Hg, falling rapidly       
Visibility: 3 miles 
6-hr Max temp: 54F
6-hr Min temp: 43F
24-hr Precip: 0.13 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.   
BHO SA 1155 W1 X 3R-F 062/54/54/2224G33/974/ 
PK WND 2233/58/ 8//// 57042 6013/ 70013 10054 20043 

10 A.M.
Weather: Light fog, light rain  
Temperature: 58F; Dew Point: 58F; Wind: SSE at 31G45 kts 
Peak Wind: 45 KTS (52 MPH) SSE at 9:57 A.M.   
Sea-level pressure: 29.63 ins. Hg, falling steadily
Visibility: 2 miles
3-hr Precip: 0.17 ins. 
BHO SA 1455 W1 X 2R-F 033/58/58/1631G45/963/ 
PK WND 1645/57/ 8//// 58029 6017/ 

1 P.M.
Weather: Light fog, moderate rain
Temperature: 60F; Dew Point: 60F; Wind: S at 31G49 kts
Peak Wind: 49 KTS (56 MPH) S at 12:47 P.M.    
Sea-level pressure: 29.52 ins. Hg, falling, then more slowly      
Visibility: 2 miles
6-hr Max temp: 61F
6-hr Min temp: 54F
6-hr Precip: 0.24 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.   
BHO SA 1755 W1 X 2R-F 996/60/60/1731G49/952/ 
PK WND 1749/47/ 8//// 56037 6024/ 10061 20054

SUMMARY FOR THURSDAY, DECEMBER 20, 2018 

TEMPERATURE (DEGREES F)
MAX.....47   NORMAL.....38
MIN.....30   NORMAL.....22
MEAN....39   NORMAL.....30

DEPARTURE FROM 30-YEAR NORMAL........................+9
TOTAL DEPARTURE FOR THE MONTH.......................-20 [-1.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............26   DEPARTURE.........-9
TOTAL HEATING UNITS FOR THE MONTH.............656   DEPARTURE........+18
TOTAL HEATING UNITS FOR THE SEASON...........1976   DEPARTURE........+76
TOTAL HEATING UNITS LAST SEASON TO DATE......1608   DIFFERENCE......+368

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................23 SW  AT 10:53 A.M.
                   AERO.........................22 SW  AT 10:52 A.M. 
                   ASOS.........................23 SW  AT 10:56 A.M. 
                   DAVIS........................25 WSW AT 10:55 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY......................16 SW  AT  5:22 A.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...................16 SW  AT 10:57 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................17 WSW AT 10:57 A.M.
AVERAGE WIND SPEED AND DIRECTION..............11.9 SW
                   ASOS.......................12.4
                   DAVIS......................11.9 SSW [211 deg.]   

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.13  DEPARTURE.......-0.03
                         ASOS..............0.13
TOTAL PRECIPITATION FOR THE MONTH..........2.08  DEPARTURE.......-1.16
                         ASOS..............2.81 *
TOTAL PRECIPITATION FOR THE YEAR..........65.45  DEPARTURE......+13.87
                         ASOS.............68.44 *
* ASOS MONTHLY AND ANNUAL PRECIPITATION IS SUSPECT

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........-0.6
TOTAL SNOWFALL FOR THE MONTH................0.1  DEPARTURE........-7.7
TOTAL SNOWFALL FOR THE SEASON...............7.7  DEPARTURE........-2.7

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/.../..          29 NW  AERO 29 NW  RMY 32
12/08 27/15/21/-13/0.00/0.0/.../..         28 NW  AERO 27 NW  RMY 29
12/09 34/17/26/-8/0.00/0.0/.../..          23 SSW AERO 21 SSW RMY 22
12/10 36/22/29/-4/0.00/0.0/.../..          24 NNW AERO 23 NNW RMY 22
12/11 36/17/27/-6/0.00/0.0/.../..          16 WSW AERO 14 WSW RMY N/A
12/12 35/18/27/-6/0.00/0.0/.../..          30 NW  AERO 29 NW  RMY M
12/13 31/16/24/-8/0.00/0.0/.../..          16 NNE AERO 12 SE  RMY N/A
12/14 46/28/37/+5/0.00/0.0/.../..          28 SSW AERO 28 SSW RMY 29
12/15 49/33/43/+11/0.04/0.0/.../..         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 Low temp since midnight is 43F; normal low is 22F


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

RECORDS FOR DECEMBER 21
HIGH 60 IN 1957
LOW -10 IN 1942
PRECIP 2.01 INS. IN 1946
SNOWFALL 11.4 INS. IN 1954
PEAK GUST 77 MPH SSE IN 1957

RECORDS FOR DECEMBER 22
HIGH 63 IN 2013
LOW -5 IN 1921
PRECIP 1.52 INS. IN 1975
SNOWFALL 8.8 INS. IN 1975
PEAK GUST 62 MPH WNW IN 1998

TODAY'S REPORT PREPARED BY: Nate Iannuccillo