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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 9, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

STORMY WEATHER HAS RETURNED WITH RAIN, STRONG WINDS,
AND MILD TEMPERATURES....

After a couple of fair, but cold days, we have returned to
the cloudy conditions that we've seemingly have become 
accustomed to the last couple of months. Rain began falling
very early this morning and had accumulated to 0.02" as of
7 A.M. this morning. Rain has continued at varying intensities
throughout the day amounting to 0.28" of additional rainfall
for the 6 hours ending at 1P.M.

A gusty southerly wind developed late this morning and has 
been rocking the observatory since. Frequents gusts over 40 mph
have been observed over the last 3 hours with a peak gust so
far of 53 mph.

The mild temperatures along with a dew point into the lower 50s
is proving to be an effective snow eater, taking our snow depth 
from 4 inches at 7 A.M. to only 2 inches by 1 P.M. More than 
likely all the snow will be gone by tomorrow morning. 

The high so far today is 52F, which is 11 degrees above the 
daily normal maximum of 41F. The low since midnight is 36F, 
which is 10 degrees above the normal minimum of 26F. Today will
mark the first day this month to average above normal.


PRELIMINARY STATS FOR NOVEMBER 2019

TEMPERATURE, Deg. F
Avg. Max. 46.0 [-4.0]
Avg. Min. 30.3 [-3.2]
Mean      38.2 [-3.5]
24-hour corrected mean: 38.0
Max. for month: 67F on the 1st
Min. for month: 15F on the 13th

HEATING DEGREE DAYS
Total heating units:    761 [+99]
Total for the season:  1237 [-24]
Total for last season: 1319

PRECIPITATION, Inches
Total: 3.74 [-1.02]
Greatest in 24 hrs: N/A 

SNOWFALL, Inches
Total: 0.1 [-2.2]
Greatest in 24 hrs: 0.1 ins. on the 12th

WIND, mph
Avg. uncorrected wind speed: 12.5 mph
Avg. corrected wind speed:   12.9 mph
Prevailing wind direction:   W [16%]
Peak gust and direction:     67 S on the 1st

SUNSHINE:
Campbell-Stokes card minutes: 8652 minutes of possible 17010 or 51%
Astronomical total minutes: 8985 minutes of possible 17640 or 51%

Today's Observations:

7 A.M.
Weather: Vertical visibility 300 feet, sky obsured, light rain and fog
Temperature: 40F; Dew Point: 40F; Wind: S at 11 kts 
Sea-level pressure: 30.24 ins. Hg, falling, then more slowly
Visibility: 1/4 miles
6-hr Max temp: 40F
6-hr Min temp: 38F
24-hr Precip:  0.02 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 W3 X 1/4R-F 239/40/40/1711/024/ 8//// 4/004 56017 6002 70002
10041 20038 

10 A.M.
Weather: Vertical visibility 300 feet, sky obsured, light rain and fog
Temperature: 45F; Dew Point: 45F; Wind: S at 14 kts 
Sea-level pressure: 30.18 ins. Hg, falling, then more rapidly
Visibility: 1/16 miles
3-hr Precip: 0.13 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 W3 X 1/16R-F 219/45/45/1614/018/ 8//// 58020 6013

1 P.M.
Weather: Overcast stratus fractus, light rain and fog 
Temperature: 52F; Dew Point: 52F; Wind: S at 29G36 kts
Sea-level pressure: 30.01 ins. Hg, falling, then more rapidly
Visibility: 3 miles
6-hr Max temp: 52F
6-hr Min temp: 40F
6-hr Precip:  0.28 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E3 OVC 3R-F 162/52/52/1829G36/001/ PK WND 1840/36/ 8/7// 4/002
58057 6028 10052 20040  


SUMMARY FOR SUNDAY, DECEMBER 8, 2019 

TEMPERATURE (DEGREES F)
MAX.....36   NORMAL.....42
MIN.....15   NORMAL.....26
MEAN....26   NORMAL.....34

DEPARTURE FROM 30-YEAR NORMAL..................... -8
TOTAL DEPARTURE FOR THE MONTH.....................-59 [-7.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............39  DEPARTURE........+8
TOTAL HEATING UNITS FOR THE MONTH..............297  DEPARTURE.......+59
TOTAL HEATING UNITS FOR THE SEASON............1534  DEPARTURE.......+35
TOTAL HEATING UNITS LAST SEASON TO DATE.......1576  DEPARTURE.......-42

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................31 SSW AT 11:23 P.M.  
                   AERO.........................32 SSW AT 11:23 P.M.   
                   ASOS.........................33 S   AT 11:44 P.M. 
                   DAVIS........................34 SSW AT 11:20 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY......................25 SSW AT 11:38 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...................25 SSW AT 11:39 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................25 SSW AT 11:38 P.M.
AVERAGE WIND SPEED AND DIRECTION..............12.4 SSW                   
                   ASOS.......................12.7  
                   DAVIS......................12.3 SW [224 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.02  DEPARTURE......-0.14
                         ASOS..............0.01
TOTAL PRECIPITATION FOR THE MONTH..........2.47  DEPARTURE......+1.16
                         ASOS..............2.60
TOTAL PRECIPITATION FOR THE YEAR..........51.55  DEPARTURE......+1.70
                         ASOS.............52.00

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.......-0.4
TOTAL SNOWFALL FOR THE MONTH...............13.2  DEPARTURE......+10.7
TOTAL SNOWFALL FOR THE SEASON..............13.3  DEPARTURE.......+8.2


PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER 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

11/01  67/35/51/+5/0.12/0.0/534/86            67 S   AERO M  M   RMY N/A
11/02  50/31/41/-5/0.00/0.0/612/99            17 WNW AERO 14 W   RMY N/A
11/03  53/35/44/-2/0.00/0.0/567/92            25 WSW AERO 23 W   RMY 26
11/04  53/33/43/-2/0.00/0.0/546/89            24 S   AERO 20 S   RMY 24
11/05  54/44/49/+4/0.33/0.0/000/00            22 S   AERO 18 WNW RMY 28
11/06  51/36/44/-1/0.00/0.0/596/98            28 WSW AERO 23 W   RMY 27
11/07  55/38/47/+2/0.27/0.0/000/00            30 S   AERO 26 SSW RMY 32
11/08  38/23/31/-13/0.00/0.0/555/92           38 NW  AERO 37 WNW RMY 44   
11/09  39/20/30/-14/0.00/0.0/583/97           22 S   AERO 18 S   RMY N/A
11/10  51/30/41/-3/0.00/0.0/174/29            30 SW  AERO 30 SW  RMY 31
11/11  52/39/46/+3/T/0.0/000/00               23 NE  AERO 22 NE  RMY 23
11/12  42/20/31/-12/0.08/0.1/000/00           37 WNW AERO 37 WNW RMY 41
11/13  28/15/22/-21/0.00/0.0/592/100          32 WNW AERO 32 WNW RMY 35
11/14  36/17/28/-14/0.00/0.0/136/23           18 SW  AERO 17 SW  RMY 20 
11/15  51/32/42/0/0.00/0.0/553/94             25 WNW AERO 25 WNW RMY N/A
11/16  35/22/29/-13/0.00/0.0/580/99           35 NNW AERO 35 NNW RMY N/A
11/17  40/21/31/-10/T/T/000/00                28 ENE AERO 27 ENE RMY 29
11/18  36/32/34/-7/..../0.0/000/00            28 NNE AERO 29 N   RMY 31
11/19  42/36/39/-2/..../0.0/000/00            12 SSW AERO  9 NNW RMY N/A
11/20  38/33/36/-4/..../T/000/00              20 NW  AERO 18 NW  RMY 21
11/21  46/30/38/-2/0.00/0.0/536/93            21 NW  AERO 21 NW  RMY N/A
11/22  52/32/42/+2/0.12/0.0/000/00            46 W   AERO 47 W   RMY 47
11/23  44/27/36/-3/0.00/0.0/503/88            29 WNW AERO 29 WNW RMY N/A
11/24  44/35/40/+1/1.49/0.0/000/00            45 N   AERO 44 NE  RMY 46 TSTM
11/25  50/34/42/+3/0.00/0.0/329/58            32 WNW AERO 35 WNW RMY 23
11/26  59/39/49/+11/0.00/0.0/544/96           28 SSW AERO 27 SSW RMY 29
11/27  50/42/46/+8/..../0.0/011/02            30 W   AERO 32 W   RMY N/A TSTM
11/28  48/30/39/+1/..../T/062/11              42 NW  AERO 44 NW  RMY 44
11/29  39/27/33/-4/0.00/0.0/433/77            35 NW  AERO 36 NW  RMY 39
11/30  35/22/29/-8/0.00/0.0/539/96            30 NW  AERO 28 WNW RMY 31

DAILY RECORDS FOR NOVEMBER

11/13/19: DAILY RECORD LOW MAXIMUM TEMPERATURE OF 28F,
          BREAKS PREVIOUS RECORD OF 30F SET IN 1920.
          It was also the third earliest maximum temperature 
          colder than 30F on record, behind only 28F on 11/8/1894 
          and 29F on 11/12/1894.

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  32/16/24/-13/..../5.8/.../..           33 ENE AERO 32 ENE RMY N/A
12/02  37/25/31/-5/..../2.7/.../..            52 NE  AERO 47 NE  RMY 53
12/03  30/23/27/-9/..../4.6/.../..            32 N   AERO 35 N   RMY 36
12/04  34/22/28/-7/..../0.0/.../..            23 WNW AERO 23 NNW RMY N/A
12/05  41/26/34/-1/..../0.0/.../..            33 NW  AERO 35 NW  RMY 37
12/06  33/23/28/-7/0.02/0.1/.../..            25 NW  AERO 23 NW  RMY 29
12/07  31/18/25/-9/0.00/0.0/.../..            25 NW  AERO 23 NW  RMY N/A
12/08  36/15/26/-8/0.00/0.0/.../..            31 SSW AERO 32 SSW RMY N/A

12/09  The low since midnight is 36F, daily normal minimum is 26F 


DAILY RECORDS FOR DECEMBER

12/01/19: DAILY RECORD SNOWFALL OF 5.8 INS.,
          BREAKS PREVIOUS RECORD OF 2.0 INS. SET IN 1902.

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

RECORDS FOR DECEMBER 9
HIGH 68 IN 1966
LOW -14 IN 1902
PRECIP 3.23 INS. IN 2014
SNOWFALL 10.8 INS. IN 2005
PEAK GUST 66 SE IN 1973

RECORDS FOR DECEMBER 10
HIGH 62 IN 1946
LOW -6 IN 1902
PRECIP 1.67 INS. IN 1907
SNOWFALL 6.0 INS. IN 1905
PEAK GUST 66e SW IN 1940

TODAY'S REPORT PREPARED BY: Matt Douglas