BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA SUNDAY, DECEMBER 20, 2020 ALL TIMES ARE IN EASTERN STANDARD TIME OVERCAST WITH SOME DISTANT SNOW BEING SEEN TO THE WEST IN THE AFTERNOON HOURS.... Today we observed mostly cloudy to overcast conditions, along with seasonably cold temperatures. Wind was light at barely 5 mph at 2 P.M. Visibility has been limited by a number of factors including haze, smoke, and even distant snow to the west at the 1 P.M. observation. We were still able to see a visibility of 60 miles at 10 A.M. Houghton's Pond and Lake Ponkapoag are now completely covered in ice due to well below freezing temperatures overnight. Mostly cloudy skies today have left us with the same snow depth we had this morning of 9 inches. The high so far today is 35F, 3 degrees below the daily normal maximum of 38F. The low since midnight is 24F, 2 degrees above the normal minimum of 22F. Today's Observations: 7 A.M. Weather: Broken altocumulus and altostratus Temperature: 26F; Dew Point: 20F; Relative Humidity: 77% Wind: S @ 8 kts Sea-level pressure: 30.24 in Hg; falling unsteadily Visibility: 25 miles, hazy 6-hr Max temp: 26F 6-hr Min temp: 24F 24-hr Precip: 0.00 ins. 24-hr Snow: 0.0 ins. Snow Depth: 9 ins. BHO SA 1155 130 BKN 25 241/26/20/1808/024/ HAZY/ 8/070 4/009 56007 10026 20024 10 A.M. Weather: Broken altocumulus and altostratus Temperature: 32F; Dew Point: 26F; Relative Humidity: 78% Wind: SSW @ 7 kts Sea-level pressure: 30.23 in Hg; rising, then falling Visibility: 60 miles, thin smoke layer 3-hr Precip: 0.00 ins. 3-hr Snow: 0.0 ins. BHO SA 1455 130 BKN 60 239/32/26/2007/023/ THN K LYR ALQDS/ 8/070 58002 1 P.M. Weather: Overcast altocumulus and altostratus Temperature: 35F; Dew Point: 29F; Relative Humidity: 80% Wind: SSE @ 7 kts Sea-level pressure: 30.13 in Hg; falling, then falling more quickly Visibility: 50 miles (30 miles SW-NW due to virga) 6-hr Max temp: 35F 6-hr Min temp: 26F 6-hr Precip: 0.00 ins. 6-hr Snow: 0.0 ins. Snow Depth: 9 ins. BHO SA 1755 130 OVC 50 202/35/29/1507/013/ VSBY 30 VIRGA SW-NW/ 8/07/ 4/009 56037 10035 20026 SUMMARY FOR SATURDAY, DECEMBER 19, 2020 TEMPERATURE (DEGREES F) MAX.......29   NORMAL.....38 MIN.......13   NORMAL.....23 MEAN......21   NORMAL.....30 DEPARTURE FROM 30-YEAR NORMAL.....................-9 TOTAL DEPARTURE FOR THE MONTH.....................+9 [+0.3 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY...............44  DEPARTURE.......+9 TOTAL HEATING UNITS FOR THE MONTH..............592  DEPARTURE......-11 TOTAL HEATING UNITS FOR THE SEASON............1565  DEPARTURE.....-299 TOTAL HEATING UNITS LAST SEASON TO DATE.......1879  DEPARTURE.....-314 PEAK WIND GUST FOR YESTERDAY (MPH):                      420C/Official..............16 SW  @ 10:41 P.M.                      AEROVANE (south tower).....16 S   @  8:51 P.M.                      ASOS.......................16 S   @  8:52 P.M.                      DAVIS #1...................16 N   @ 12:11 A.M.                      DAVIS #2 (south tower).....16 N   @ 12:11 A.M.                      RMY........................17                            VECTOR.....................17                          MERLIN.....................15 FASTEST MILE FOR YESTERDAY: CONTACTING/OFFICIAL.............................14 NNW @ 12:46 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................14 N   @ 12:50 A.M. MAXIMUM 2-MINUTE DAVIS #1 AVERAGE...............14 N   @ 12:13 A.M. MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............14 N   @ 12:13 A.M. AVERAGE WIND SPEED AND DIRECTION:                      CONTACTING/OFFICIAL....6.8 NNW [163 total miles]                      ASOS...................7.5     [180 total miles]                      DAVIS #1...............7.5 WNW [180 total miles]                      DAVIS #2...............7.9 WNW [183 total miles]                      RMY....................7.5 W   [180 total miles]                      VECTOR.................8.0     [184 total miles] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST): TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.......0.00  DEPARTURE....-0.15                              ASOS.............0.00 TOTAL PRECIPITATION FOR THE MONTH.............5.01  DEPARTURE....+1.93                              ASOS.............5.51 TOTAL PRECIPITATION FOR THE YEAR.............51.41  DEPARTURE....-0.20                               ASOS...........52.84 SNOWFALL (INCHES) THROUGH THIS MORNING (EST): TOTAL SNOWFALL 24 HOURS ENDING 7 A.M...........0.0  DEPARTURE.....-0.5 TOTAL SNOWFALL FOR THE MONTH..................19.7  DEPARTURE....+12.5 TOTAL SNOWFALL FOR THE SEASON.................26.2  DEPARTURE....+16.9 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   62/40/51/+14/0.61/0.0/.../..      60 S    AERO 67 W    RMY 64 12/02   42/32/37/+1/0.00/0.0/.../..       32 SW   AERO 32 SW   RMY 35 12/03   49/30/40/+4/0.00/0.0/.../..       25 SSW  AERO 25 SSW  RMY 28 12/04   58/40/49/+14/0.06/0.0/.../..      35 SSW  AERO 35 SSW  RMY 37 12/05   42/32/37/+2/2.13/2.8/.../..       58 NNW  AERO 58 NNW  RMY 67 12/06   34/26/30/-5/0.01/T/.../..        E44 WNW  AERO 44 WNW  RMY 49 12/07   33/22/28/-6/T/T/.../..            24 NW   AERO 26 NW   RMY 26 12/08   29/22/26/-8/T/T/.../..            24 NW   AERO 25 NW   RMY 28 12/09   34/19/27/-7/T/T/.../..            16 W    AERO 17 W    RMY 19 12/10   42/30/36/+3/0.00/0.0/.../..       30 WNW  AERO 31 WNW  RMY 29 12/11   50/31/41/+8/0.00/0.0/.../..       32 SW   AERO 35 SW   RMY 34 12/12   48/40/44/+11/0.38/0.0/.../..      25 E    AERO 21 E    RMY 25 12/13   58/35/47/+15/0.00/0.0.../..       28 W    AERO 31 WSW  RMY 31 12/14   35/30/33/+1/0.10/0.4/.../..       25 N    AERO 25 N    RMY 29 12/15   34/21/28/-4/0.00/0.0/.../..       32 WNW  AERO 33 WNW  RMY 38 12/16   27/13/20/-11/..../1.4/.../..      38 E    AERO 37 E    RMY 39 12/17   31/19/25/-6/..../15.1/.../..      55 ENE  AERO 56 ENE  RMY 59 12/18   27/18/23/-8/0.00/0.0/.../..       28 N    AERO 26 N    RMY 27 12/19   29/13/21/-9/0.00/0.0/.../..       16 SW   AERO 16 S    RMY 16 12/20   The low since midnight is 24F, the daily normal low is 22F DAILY RECORDS FOR DECEMBER 2020 12/17/20: DAILY RECORD SNOWFALL OF 15.1 INCHES, BREAKS PREVIOUS RECORD OF 7.5 INCHES SET IN 1988 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 20 HIGH 61 IN 1957 LOW -16 IN 1942 PRECIP 1.69 INS. IN 1936 SNOWFALL 13.7 INS. IN 2009 PEAK GUST 75 MPH S IN 2002 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 TODAY'S REPORT PREPARED BY: Benjamin Turner