BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, DECEMBER 16, 2017   ALL TIMES ARE IN EASTERN STANDARD TIME 0.1 IN. OF SNOW OVERNIGHT AND COLD TEMPERATURES 0.1 in. of snow fell last night on Great Blue Hill. This was equal to a trace of liquid precipitation. The morning started with mostly clear skies, but a layer of broken altocumulus moved in by the afternoon. Distant haze remained in the area all day, so visibility did not exceed 60 miles. Yesterday, there was a maximum temperature of 24F and a minimum of 12F, making the average for the day 18F (14F below normal). Temperatures were slightly warmer today. The minimum this morning was 17F, and a maximum of 31F was reached by the 1 P.M. EST observation. The cumulative departure for the month of December is now at +/- 0F.  Today's Observations: 7 A.M. Weather: Clear, few stratocumulus NNE-S, few altocumulus NNW-N, few  altocumulus NNW-N, few altostratus S-SE Temperature: 17F; Dew Point: 14F; Wind: WSW at 8G14 kts Sea-level pressure: 29.88 ins. Hg, rising, then less quickly     Visibility: 20 miles, hazy 6-hr Max temp: 20F 6-hr Min temp: 17F 24-hr precip: Trace 24-hr snowfall: 0.1 in. Snow cover: 1 in. BHO SA 1155 CLR 20 118/17/14/2508G14/988/ NEW SNW PST 24 HRS 0.1 INS FEW SC  NNE-S FEW AC NNW-N FEW AS S-SE HAZY/ 8/530 4/001 51023 10020 20017 10 A.M. Weather: Clear, few cumulus NE, few altocumulus SW-WNW, few cirrus in all directions Temperature: 25F; Dew Point: 15F; Wind: W at 11G21 kts Sea-level pressure: 29.94 ins. Hg, rising, then less quickly   Visibility: 60 miles, distant haze in all directions 3-hr precip: 0.00 ins. 3-hr snowfall: 0.0 ins.  BHO SA 1455 CLR 60 140/25/15/2611G21/994/ FEW CU NE FEW AC SW-WNW FEW CI  ALQDS DSNT HZ ALQDS/ 8/131 53022 1 P.M. Weather: Few stratocumulus SE-NE, broken altocumulus Temperature: 30F; Dew Point: 14F; Wind: WSW at 14G21 kts Sea-level pressure: 29.89 ins. Hg, falling unsteadily  Visibility: 60 miles, distant haze in all directions 6-hr Max temp: 31F 6-hr Min temp: 17F 6-hr precip: 0.00 ins. 6-hr snowfall: 0.0 ins. Snow cover: 1 in. BHO SA 1755 E110 BKN 60 122/30/14/2514G21/989/ FEW SC SE-NE PK WND 2626/39  DSNT HZ ALQDS/ 8/330 4/001 56018 10031 20017 SUMMARY FOR FRIDAY, DECEMBER 15, 2017   TEMPERATURE (DEGREES F) MAX.....24   NORMAL.....39 MIN.....12   NORMAL.....24 MEAN....18   NORMAL.....32 DEPARTURE FROM 30-YEAR NORMAL..........................-14 TOTAL DEPARTURE FOR THE MONTH...........................+0 [-0.2 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY.............47  DEPARTURE.........+13 TOTAL HEATING UNITS FOR THE MONTH............464  DEPARTURE..........-1 TOTAL HEATING UNITS FOR THE SEASON..........1433  DEPARTURE........-294 TOTAL HEATING UNITS LAST SEASON TO DATE.....1507  DIFFERENCE........-74 PEAK GUST AND AVERAGE WIND SPEED (MPH)  PEAK WIND GUST FOR YESTERDAY...................25 W AT 12:17 A.M.                     AERO........................23 W AT 12:14 A.M.                    ASOS........................24 W AT 12:18 A.M.                    DAVIS.......................23 W AT 12:18 A.M. RMY N/A FASTEST MILE FOR YESTERDAY.....................19 W AT 12:23 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE..................18 W AT 12:23 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.................18 W AT 12:23 A.M. AVERAGE WIND SPEED AND DIRECTION..............6.4 S                     ASOS.......................6.4                    DAVIS......................6.4 WSW [247 DEG.]   PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...TRACE  DEPARTURE......-0.16                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.54  DEPARTURE......-0.92                          ASOS..............1.63 TOTAL PRECIPITATION FOR THE YEAR..........51.38  DEPARTURE......+0.39                          ASOS...............N/A ** ** ASOS annual total not available due to erroneous readings SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.1  DEPARTURE.......-0.4 TOTAL SNOWFALL FOR THE MONTH................5.7  DEPARTURE.......+0.4 TOTAL SNOWFALL FOR THE SEASON...............5.7  DEPARTURE.......-2.2  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 50/35/43/+6/0.04/262/47          28 NW  AERO 29 NW  RMY 30 12/02 42/29/36/0/0.00/033/06           20 NNW AERO 18 NNW RMY N/A 12/03 42/32/37/+1/0.00/172/31          14 N   AERO 10 N   RMY N/A  12/04 43/32/38/+3/0.00/522/94          16 E   AERO 14 E   RMY N/A  12/05 58/34/46/+11/0.18/000/00         62 S   AERO 66 S   RMY 65 12/06 56/32/44/+9/0.54/160/29          52 S   AERO 55 S   RMY N/A 12/07 44/30/37/+3/0.00/522/98          25 WSW AERO 24 WSW RMY 25 12/08 38/28/33/-1/0.00/.../..          21 W   AERO 18 W   RMY 20 12/09 34/28/31/-3./..../.../..         23 NNW AERO 23 NNW RMY 23  12/10 35/27/31/-2/..../.../..          30 W   AERO 30 W   RMY 27  12/11 38/29/34/+1/0.00/.../..          23 W   AERO 21 W   RMY 22 12/12 43/31/37/+4/0.06/.../..          35 W   AERO 31 W   RMY N/A 12/13 31/18/25/-7/0.00/.../..          44 W   AERO 44 W   RMY 44 12/14 27/14/21/-11/T/.../..            35 WSW AERO 33 W   RMY 34  12/15 24/12/18/-14/T/.../..            25 W   AERO 23 W   RMY N/A 12/16 Low temp since midnight is 17F; normal low is now 24F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):       RECORDS FOR DECEMBER 16 HIGH 61 IN 1971 LOW -2 IN 1930 PRECIP 1.67 INS. IN 1960 SNOW 8.5 INS. IN 2007 WIND 73 MPH SSE IN 1982 RECORDS FOR DECEMBER 17 HIGH 63 IN 2000 LOW -10 IN 1942 PRECIP 3.03 INS. IN 1888 SNOWFALL 7.5 INS. IN 1988 PEAK GUST 78 MPH SSE IN 2000 TODAY'S REPORT PREPARED BY: Lizzy Suzedell