BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, DECEMBER 13, 2016   DRY CONDITIONS RETURN UNDER PARTLY SUNNY SKIES Increasing pressure gave us lower dew points and visibility reaching 70 miles today.  Temperatures started slightly cooler than yesterday morning but were still able to rise to a max. of  40F by 1:00PM. Westerly winds became light by early afternoon. Although skies turned broken by early afternoon, they were mostly cloudy with cirrus and allowed abundant sunshine.   7 A.M. Weather: Few cumulus NNW-S, scattered cirrus Temperature: 31F; Dew Point: 21F; Wind: W at 12 kts Sea-level pressure: 30.06 ins. Hg, rising, then more quickly Visibility: 70 miles 6-hr Max temp: 32F 6-hr Min temp: 30F 24-hr precip: 0.15 in. BHO SA 1155 250 SCT 70 181/31/21/2812/006/ FEW CU NNW-S/ 8/101 53025 MANUAL 70015 ASOS 70019 10032 20030 10 A.M. Weather: Few cumulus NNE-E, scattered cirrus Temperature: 35F; Dew Point: 22F; Wind: W at 8 kts Sea-level pressure: 30.13 ins. Hg, rising, then more slowly Visibility: 70 miles BHO SA 1455 250 SCT 70 204/35/22/2708/013/ FEW CU NNE-E/ 8/101 51023 1 P.M. Weather: Broken cirrus Temperature: 40F; Dew Point: 19F; Wind: W at 4 kts, Wind Speed: Light Sea-level pressure: 30.11 ins. Hg, falling, then more slowly Visibility: 70 miles 6-hr Max temp: 40F 6-hr Min temp: 30F BHO SA 1755 E250 BKN 70 197/39/19/2804/011/ WND LGT/ 8/001 56007 10040 20030 SUMMARY FOR MONDAY, DECEMBER 12, 2016   TEMPERATURE (DEGREES F) MAX.....41   NORMAL.....40 MIN.....27   NORMAL.....25 MEAN....34   NORMAL.....33 DEPARTURE FROM 30-YEAR NORMAL........................+1 TOTAL DEPARTURE FOR THE MONTH........................-7 [-0.8 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............31   DEPARTURE..........-2 TOTAL HEATING UNITS FOR THE MONTH.............372   DEPARTURE..........+6 TOTAL HEATING UNITS FOR THE SEASON...........1402   DEPARTURE........-225 TOTAL HEATING UNITS LAST SEASON TO DATE......1252   DIFFERENCE.......+150 PEAK GUST AND AVERAGE WIND SPEED (MPH)  PEAK WIND GUST FOR YESTERDAY...................29 ESE AT  5:32 A.M.                    ASOS........................29 SE  AT  5:58 A.M.                    DAVIS.......................28 ESE AT  5:57 A.M. RMY N/A FASTEST MILE FOR YESTERDAY.....................23 ESE AT  7:17 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE..................21 SW  AT 11:15 A.M.  MAXIMUM 2-MINUTE DAVIS AVERAGE.................21 ESE AT  7:19 A.M. AVERAGE WIND SPEED AND DIRECTION.............13.1 SW                    ASOS......................13.2                    DAVIS.....................11.8 S [190 Deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.15  DEPARTURE......-0.02                          ASOS..............0.19 TOTAL PRECIPITATION FOR THE MONTH..........0.84  DEPARTURE......-1.14                          ASOS..............0.93 TOTAL PRECIPITATION FOR THE YEAR..........37.81  DEPARTURE.....-12.70                          ASOS.............38.36 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.......-0.4 TOTAL SNOWFALL FOR THE MONTH................1.7  DEPARTURE.......-2.3 TOTAL SNOWFALL FOR THE SEASON...............1.7  DEPARTURE.......-4.9 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 12/1  55/39/47/+10/0.20/0.0/385/69          36 W   AERO 37 W   RMY 36 12/2  48/34/41/+5/0.00/0.0/535/96           32 W   AERO 32 W   RMY N/A 13/3  44/31/38/+2/0.00/0.0/.../..           37 WNW AERO 39 WNW RMY 40 12/4  39/27/33/-2/0.00/0.0/.../..           25 NW  AERO 25 NW  RMY N/A 12/5  36/27/32/-3/0.13/0.4/.../..           26 W   AERO 25 W   RMY 29 12/6  42/30/36/+1/0.00/0.0/.../..           22 W   AERO 21 W   RMY N/A 12/7  39/34/37/+3/0.10/0.0/.../..           21 E   AERO 21 E   RMY N/A 12/8  40/29/35/+1/0.00/0.0/.../..           30 W   AERO 31 W   RMY 33 12/9  35/21/28/-6/0.00/0.0/.../..           35 W   AERO 36 WNW RMY 34 12/10 27/17/22/-11/0.00/0.0/.../..          26 WNW AERO 27 WNW RMY 29  12/11 33/16/25/-8/..../.../.../..           17 SSW AERO 15 SW  RMY N/A 12/12 41/27/34/+1/..../.../.../..           29 ESE AERO 29 SE  RMY N/A 12/13 Low temp since midnight is 30F; normal low is now 25F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 13 HIGH 60 IN 1984 LOW 0 IN 1893 PRECIP 1.45 INS. IN 1983 SNOWFALL 9.2 INS. IN 2007 PEAK GUST 81e WNW IN 1976 RECORDS FOR DECEMBER 14 HIGH 62 IN 1901 LOW -6 IN 1893 PRECIP 1.94 INS. IN 2002 SNOWFALL 8.0 INS. IN 1907 PEAK GUST 78e ENE IN 1941 TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle