BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, MAY 17, 2020 ALL TIMES ARE IN EASTERN STANDARD TIME OVERCAST WITH SOME SUN BREAKING OUT IN THE AFTERNOON.... The summit of Great Blue Hill experienced overcast skies with a light wind shifting from south to west. Visibility was 65 miles on average due to a slight distant haze. Pressure has been on a steady decline all day, with an increase of stratus clouds. The sun has broken out in spots during the afternoon hours, even though the sky still remains mostly covered with clouds. The high so far today is 65F, this is 2 degrees below the daily normal high of 67F. The low since midnight is 47F, which is a degree below the daily normal low of 48F. PRELIMINARY STATS FOR APRIL 2020 TEMPERATURE, Deg. F Avg. Max. 50.6 [-5.1] Avg. Min. 35.8 [-1.9] Mean      43.4 [-3.3] 24-hour corrected mean: 42.9 Max. for month: 63F on the 7th Min. for month: 28F on the 1st HEATING DEGREE DAYS Total heating units:    648 [+97] Total for the season:  5521 [-514] Total for last season: 5900 PRECIPITATION, Inches Total: 7.71 [+3.16] Greatest in 24 hrs: 2.23 ins. on the 3rd-4th SNOWFALL, Inches Total: 4.3 [+1.3] Greatest in 24 hrs: 4.3 ins. on the 18th WIND, mph Avg. uncorrected wind speed: 13.9 mph Avg. corrected wind speed:   14.3 mph Prevailing wind direction:   W [24%] Peak gust and direction:     79 S on the 13th SUNSHINE: Campbell-Stokes card minutes: 8358 minutes of possible 23250 or 36% Astronomical total minutes: 8676 minutes of possible 24148 or 36% Today's Observations: 7 A.M. Weather: Broken stratus Temperature: 52F; Dew Point: 46F; Relative Humidity: 79% Wind: SSW at 7 kts   Sea-level pressure: 30.34 ins. Hg: rising steadily Visibility: 65 miles 6-hr Max temp: 52F 6-hr Min temp: 47F 24-hr Precip:  0.00 ins. 24-hr Snowfall: 0.0 ins. BHO SA 1155 E50 BKN 65 273/52/46/2307/034/ 8/600 53016 10052 20047 10 A.M. Weather: Broken stratus Temperature: 61F; Dew Point: 42F; Relative Humidity: 49% Wind: SSW at 8 kts Sea-level pressure: 30.33 ins. Hg: falling steadily Visibility: 65 miles 3-hr Precip:  0.00 ins. 3-hr Snowfall: 0.0 ins. BHO SA 1455 E50 BKN 65 270/61/42/2108/033/ 8/600 58003 1 P.M. Weather: Overcast stratus Temperature: 65F; Dew Point: 44F; Relative Humidity: 47% Wind: W at 7 kts Sea-level pressure: 30.27 ins. Hg: falling steadily Visibility: 70 miles 6-hr Max temp: 65F 6-hr Min temp: 52F 6-hr Precip:  0.00 ins. 6-hr Snowfall: 0.0 ins. BHO SA 1755 E50 OVC 70 252/65/44/2707/027/ 8/6// 58018 10065 20052 SUMMARY FOR SATURDAY, MAY 16, 2020 TEMPERATURE (DEGREES F) MAX.....69   NORMAL.....67 MIN.....47   NORMAL.....47 MEAN....58   NORMAL.....57 DEPARTURE FROM 30-YEAR NORMAL...................+1 TOTAL DEPARTURE FOR THE MONTH..................-37 [-2.5 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY...............7   DEPARTURE........-1 TOTAL HEATING UNITS FOR THE MONTH..............199  DEPARTURE.......+30 TOTAL HEATING UNITS FOR THE SEASON............5720  DEPARTURE......-483 TOTAL HEATING UNITS LAST SEASON TO DATE.......6132  DEPARTURE......-412 COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY................0  DEPARTURE........-1 TOTAL COOLING UNITS FOR THE MONTH................2  DEPARTURE........-4 TOTAL COOLING UNITS FOR THE SEASON...............2  DEPARTURE........-6 TOTAL COOLING UNITS LAST SEASON TO DATE..........0  DEPARTURE........+2 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................31 NW  AT 12:20 P.M.                      AERO.........................31 NW  AT 7:06 A.M.                     ASOS.........................31 NW  AT 7:23 A.M.                    DAVIS........................33 WNW AT 7:08 A.M. RMY 32 FASTEST MILE FOR YESTERDAY......................21 NW  AT 7:08 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................21 NW  AT 7:23 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................22 NW  AT 7:08 A.M. AVERAGE WIND SPEED AND DIRECTION................12.0 NW                                  ASOS.........................11.2                    DAVIS........................12.3 NW [311 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE......-0.12                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........2.55  DEPARTURE......+0.60                          ASOS..............2.54 TOTAL PRECIPITATION FOR THE YEAR..........19.59  DEPARTURE......-0.91                          ASOS.............20.04 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........0.0 TOTAL SNOWFALL FOR THE MONTH..............Trace  DEPARTURE........0.0 TOTAL SNOWFALL FOR THE SEASON..............31.9  DEPARTURE......-30.8 PRELIMINARY CLIMATE SUMMARY FOR APRIL 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 04/01  42/28/35/-6/0.00/0.0/008/01         28 NE  AERO 28 NE  RMY 30 04/02  46/35/41/0/0.34/0.0/000/00          39 NW  AER0 40 NW  RMY 41 04/03  42/38/40/-2/2.14/0.0/000/00         48 NE  AERO 53 NE  RMY 49 04/04  46/36/41/-1/0.24/0.0/278/36         38 NE  AERO 38 NE  RMY N/A 04/05  55/36/46/+3/0.00/0.0/039/05         22 S   AERO 21 S   RMY 21 04/06  61/40/51/+8/0.00/0.0/732/94         29 NW  AERO 30 NW  RMY 29 04/07  63/42/53/+10/0.00/0.0/649/83        29 W   AERO 30 W   RMY 28 04/08  50/41/46/+2/0.08/T/047/06           23 S   AERO 22 S   RMY 22 04/09  47/37/42/-2/0.66/T/000/00           58 W   AERO 58 W   RMY 56 04/10  47/35/41/-4/0.02/T/324/41           48 W   AERO 50 W   RMY 53 04/11  51/33/42/-3/0.00/0.0/730/92         38 WNW AERO 39 WNW RMY 40 04/12  60/33/47/+2/0.00/0.0/326/41         38 S   AERO 40 S   RMY N/A 04/13  59/50/55/+9/1.42/0.0/000/00         79 S   AERO 83 S   RMY 78 04/14  57/41/49/+3/0.00/0.0/641/80         41 W   AERO 40 W   RMY N/A 04/15  52/36/44/-3/0.02/0.0/450/56         37 W   AERO 36 W   RMY 37 04/16  47/32/40/-7/T/T/379/47              33 WNW AERO 33 WNW RMY 32 04/17  49/29/39/-8/0.01/0.0/591/73         41 W   AERO 39 W   RMY 41 04/18  37/31/34/-14/0.73/4.3/000/00        29 NE  AERO 25 NE  RMY 25 04/19  60/31/46/-2/0.00/0.0/693/85         40 SSW AERO 40 SSW RMY 41 04/20  49/37/43/-6/0.00/0.0/000/00         25 ENE AERO 22 W   RMY N/A 04/21  53/33/43/-6/0.34/T/271/33           52 S   AERO 52 S   RMY 52 04/22  43/30/37/-12/0.00/0.0/601/73        51 W   AERO 50 W   RMY 50 04/23  55/29/42/-8/0.00/0.0/545/66         31 W   AERO 29 W   RMY N/A 04/24  42/37/40/-10/0.34/0.0/000/00        31 NNE AERO 29 NNE RMY 29 04/25  60/38/49/-1/0.00/0.0/557/67         25 S   AERO 24 S   RMY 24 04/26  51/38/45/-6/0.42/0.0/000/00         51 NE  AERO 50 NE  RMY 50 04/27  39/35/37/-14/0.94/T/000/00          54 NE  AERO 52 NNE RMY 55 04/28  48/35/42/-10/0.00/0.0/159/19        28 N   AERO 27 N   RMY N/A 04/29  55/35/45/-7/0.00/0.0/656/78         24 ENE AERO 23 ENE RMY 22 04/30  52/42/47/-5/0.01/0.0/000/00         36 SE  AERO 32 SE  RMY N/A DAILY RECORDS FOR APRIL 2020 4/13/2020 NEW PEAK GUST OF 79 MPH S, REPLACING THE OLD RECORD OF 59 MPH SSW IN 1995 4/18/2020 NEW RECORD SNOWFALL OF 4.3 INS, REPLACING THE OLD RECORD OF 3.7 INS IN 1965 4/27/2020 NEW RECORD LOW MAX TEMPERATURE OF 39F, REPLACING THE OLD RECORD OF 40F IN 1917 PRELIMINARY CLIMATE SUMMARY FOR MAY 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 05/01  64/52/58/+5/..../0.0/.../..         46 SSE  AERO 44 SSE RMY N/A 05/02  70/42/56/+3/..../0.0/.../..         41 NW   AERO 40 NW  RMY N/A 05/03  78/55/67/+14/0.00/0.0/.../..        35 SSW  AERO 35 SSW RMY 36 05/04  72/45/59/+5/T/0.0/.../..            37 NW   AERO 40 WNW RMY 39   05/05  60/40/50/-4/0.00/0.0/.../..         31 NW   AERO 32 NW  RMY N/A 05/06  57/38/48/-6/T/0.0/.../..            24 ESE  AERO 22 ENE RMY 22 05/07  63/37/50/-5/0.00/0.0/.../..         30 WSW  AERO 29 WSW RMY N/A 05/08  57/40/49/-6/..../0.0/.../..         31 W    AERO 32 W   RMY N/A 05/09  44/32/38/-17/..../T/.../..          52 W    AERO 53 W   RMY 54 05/10  59/31/45/-10/0.00/0.0/.../..        46 W    AERO 46 W   RMY 49 05/11  65/43/54/-2/0.22/0.0/.../..         39 S    AERO 43 S   RMY 41 05/12  55/37/46/-10/0.00/0.0/.../..        37 W    AERO 37 W   RMY 37 05/13  59/32/46/-10/0.00/0.0/.../..        37 WNW  AERO 37 WNW RMY 38 05/14  70/40/55/-2/0.00/0.0/.../..         29 W    AERO 26 W   RMY 27 05/15  78/50/64/+7/..../0.0/.../..         40 WSW  AERO 40 WSW RMY 43 05/16  69/47/58/+1/..../0.0/.../..         31 NW   AERO 31 NW  RMY 32 05/17 The low since midnight is 47F, the daily normal low is 48F   DAILY RECORDS FOR MAY 2020 5/13/2020: NEW RECORD LOW OF 32F, REPLACING 35F SET IN 1914 AND 2005 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):   RECORDS FOR MAY 17 HIGH 90F IN 2017 LOW 34F IN 1956, 1957 PRECIP 2.07 INS IN 1916 PEAK GUST 52 MPH SW IN 1967, W IN 1974 RECORDS FOR MAY 18 HIGH 96F IN 2017(RECORD FOR MAY) LOW 35F IN 2002 PRECIP 1.93 INS IN 2007 SNOW TRACE IN 2002 (Ice pellets) PEAK GUST 64 MPH SSW IN 2000 TODAY'S REPORT PREPARED BY: Benjamin Turner