BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, SEPTEMBER 25, 2019 ALL TIMES ARE IN EASTERN STANDARD TIME A FAIR EARLY FALL DAY ATOP GREAT BLUE HILL.... Today began clear with a visibility of 70 miles, increasing to a max of 85 miles at the 10 A.M. observation. Skies became cloudier as the day went on, being partly cloudy at 1 P.M. The air remains dry, with dew points in the upper 40s. A cool breeze has been coming in from the northwest at around 10 mph. Very little has been measured for rainfall this month, with a monthly total of only 1.02 inches. That is 2.15 inches below normal at this point in the month. The high so far today has been 71F, which is 3 degrees above the normal high of 68F. The low since midnight was 50F, which is a degree above our normal low of 51F. Today's Observations: 7 A.M. Weather: Clear, few distant cumulus NW-SE Temperature: 53F; Dew Point: 47F; Wind: W at 7 kts Sea-level pressure: 29.88 ins. Hg, rising, then more slowly Visibility: 70 miles 6-hr Max temp: 54F 6-hr Min temp: 50F 24-hr Precip: 0.00 ins. BHO SA 1155 CLR 70 117/53/47/2707/988/ FEW DSNT CU NW-SE/ 8/100 51011 10054 20050 10 A.M. Weather: Scattered cumulus Temperature: 65F; Dew Point: 54F; Wind: W at 5 kts, Wind: Light Sea-level pressure: 29.89 ins. Hg, falling then rising Visibility: 85 miles 3-hr Precip: 0.00 ins. BHO SA 1455 30 SCT 85 121/65/54/2905/989/ WND LGT/ 8/100 50004 1 P.M. Weather: Broken cumulus and cirrus Temperature: 69F; Dew Point: 47F; Wind: NW at 10 kts Sea-level pressure: 29.85 ins. Hg, falling, then steady Visibility: 80 miles 6-hr Max temp: 71F 6-hr Min temp: 53F 6-hr Precip: 0.00 ins. BHO SA 1755 E40 BKN 250 BKN 80 108/69/47/3110/985/ 8/102 56013 10071 20053 SUMMARY FOR TUESDAY, SEPTEMBER 24, 2019 TEMPERATURE (DEGREES F) MAX.....76   NORMAL.....69 MIN.....56   NORMAL.....52 MEAN....66   NORMAL.....60 DEPARTURE FROM 30-YEAR NORMAL.....................+6 TOTAL DEPARTURE FOR THE MONTH.....................+7 [+0.1 DEGREES/DAY] HEATING DEGREE DAYS (SEASON AUG TO JUL) TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE.........-6 TOTAL HEATING UNITS FOR THE MONTH..............64   DEPARTURE........-10 TOTAL HEATING UNITS FOR THE SEASON.............76   DEPARTURE........-23 TOTAL HEATING UNITS LAST SEASON TO DATE........56   DEPARTURE........+20 COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY...............1   DEPARTURE..........0 TOTAL COOLING UNITS FOR THE MONTH..............54   DEPARTURE.........-1 TOTAL COOLING UNITS FOR THE SEASON............673   DEPARTURE........+81 TOTAL COOLING UNITS LAST SEASON TO DATE.......855   DEPARTURE.......-182 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................26 W   AT  4:04 P.M.                    AERO.........................26 W   AT  2:52 P.M.                    ASOS.........................27 W   AT  4:03 P.M.                    DAVIS........................29 W   AT  4:01 P.M. RMY 27 FASTEST MILE FOR YESTERDAY......................21 W   AT  3:08 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................20 W   AT  4:04 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................21 WSW AT  3:28 P.M. AVERAGE WIND SPEED AND DIRECTION................11.0 W                    ASOS.........................11.1                    DAVIS........................11.4 W [273 deg.] 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..........1.02  DEPARTURE......-2.15                          ASOS..............0.98 TOTAL PRECIPITATION FOR THE YEAR..........38.17  DEPARTURE......-0.03                          ASOS.............38.02 PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA DATE: MAX/MIN/MEAN/DEP/PRECIP/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 9/01  73/56/65/-3/0.00/703/89                21 ENE AERO 14 ENE RMY 18 9/02  75/57/66/-2/0.37/165/21                39 W   AERO 41 W   RMY 41 9/03  77/61/69/+2/0.00/643/82                18 S   AERO 16 S   RMY N/A 9/04  83/61/72/+5/0.00/375/48                30 SW  AERO 28 SW  RMY 30 9/05  68/54/61/-6/0.00/513/66                23 NW  AERO 17 NW  RMY N/A 9/06  65/56/61/-6/0.03/054/07                37 ENE AERO 36 ENE RMY 36 9/07  70/51/61/-5/0.27/325/42                37 N   AERO 37 N   RMY N/A 9/08  73/53/63/-3/0.00/631/82                25 W   AERO 21 W   RMY N/A 9/09  71/54/63/-3/0.00/537/70                17 SE  AERO 16 SE  RMY 16 9/10  73/57/65/0/0.00/207/27                 25 S   AERO 25 S   RMY N/A 9/11  83/63/73/+8/0.00/419/55                31 SW  AERO 32 SW  RMY N/A 9/12  70/52/61/-4/0.11/015/02                29 ENE AERO 28 ENE RMY 28 9/13  65/49/57/-7/0.00/741/98                29 ENE AERO 27 ENE RMY 27 9/14  69/49/59/-5/0.19/030/04                36 S   AERO 37 S   RMY 37 9/15  78/62/70/+6/0.00/600/80                24 W   AERO 23 W   RMY 22 9/16  72/54/63/0/0.00/673/90                 25 WNW AERO 23 WNW RMY 25 9/17  67/49/58/-5/0.00/611/82                23 NW  AERO 23 N   RMY N/A 9/18  61/49/55/-7/0.00/.../..                26 NE  AERO 25 NE  RMY 25 9/19  67/43/55/-7/0.00/.../..                17 NE  AERO 18 NE  RMY N/A 9/20  78/50/64/+2/0.00/.../..                21 W   AERO 18 W   RMY 20 9/21  83/60/72/+11/0.00/.../..               21 WNW AERO 18 WNW RMY N/A 9/22  85/62/74/+13/0.00/.../..               24 SW  AERO 23 SW  RMY 25 9/23  88/65/77/+17/0.00/.../..               29 SSW AERO 28 SSW RMY 29 9/24  76/56/66/+6/0.04/.../..                26 W   AERO 26 W   RMY 27   9/25  The low since midnight is 50F, normal daily minimum is 51F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR SEPTEMBER 25 HIGH 87F IN 1970 LOW 31F IN 1950 PRECIP 2.68 INCHES IN 1961 PEAK GUST 63 MPH SSW IN 1991 RECORDS FOR SEPTEMBER 26 HIGH 91F IN 2007 LOW 36F IN 1905,1922,1978 PRECIP 3.84 INCHES IN 1888 PEAK GUST 54e MPH S IN 1977 TODAY'S REPORT PREPARED BY: Benjamin Turner and Greg White