BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, MAY 10, 2020 ALL TIMES ARE IN EASTERN STANDARD TIME A BREEZY AND FAIR WEATHER DAY WITH A STRONG WESTERLY WIND IN THE AFTERNOON HOURS.... The summit of Great Blue Hill saw another fair weather day, with strong winds from the west in the afternoon. Wind speed has reached 25 mph on average, with a max gust of almost 50 mph. Skies have remained partly cloudy, and visibility is excellent at 85 miles. Conditions are dry, with a humidity of 30% seen at the 1 P.M. observation. The high so far today is 54F, this is 11 degrees below our daily normal high temperature of 65F. The low since midnight is 31F, which is 15 degrees below the daily normal low of 46F. 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: N/A 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: N/A Astronomical total minutes: N/A Today's Observations: 7 A.M. Weather: Scattered stratocumulus and altostratus Temperature: 38F; Dew Point: 26F; Relative Humidity: 62% Wind: WNW at 10G19 kts   Sea-level pressure: 29.96 ins. Hg: rising steadily Visibility: 80 miles 6-hr Max temp: 38F 6-hr Min temp: 31F 24-hr Precip:   Trace 24-hr Snowfall: Trace BHO SA 1155 60 SCT 150 SCT 80 147/38/26/2310G19/996/ NEW SNW PST 24 HRS TRACE/ 8/460 51007 10038 20031 10 A.M. Weather: Broken stratocumulus Temperature: 46F; Dew Point: 26F; Relative Humidity: 44% Wind: W at 27G31 kts, peak of 36 mph at 9:46 A.M. Sea-level pressure: 29.96 ins. Hg: falling steadily Visibility: 80 miles 3-hr Precip:  0.00 ins. 3-hr Snowfall: 0.0 ins. BHO SA 1455 E60 BKN 80 145/46/26/2814G31/996/ PK WND 2731/46/ 8/800 58002 1 P.M. Weather: Broken stratocumulus and cirrostratus Temperature: 54F; Dew Point: 25F; Relative Humidity: 32% Wind: W at 18G27 kts, peak of 41 mph at 12:27 P.M. Sea-level pressure: 29.93 ins. Hg: falling steadily Visibility: 85 miles 6-hr Max temp: 54F 6-hr Min temp: 38F 6-hr Precip:  0.00 ins. 6-hr Snowfall: 0.0 ins. BHO SA 1755 E60 BKN 250 BKN 85 136/54/25/2618G27/993/ PK WND 2635/27/ 8/808 58009 10054 20038 SUMMARY FOR SATURDAY, MAY 9, 2020 TEMPERATURE (DEGREES F) MAX.....44   NORMAL.....64 MIN.....32   NORMAL.....46 MEAN....38   NORMAL.....55 DEPARTURE FROM 30-YEAR NORMAL..................-17 TOTAL DEPARTURE FOR THE MONTH..................-11 [-1.4 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY...............27  DEPARTURE.......+17 TOTAL HEATING UNITS FOR THE MONTH..............112  DEPARTURE.......+9 TOTAL HEATING UNITS FOR THE SEASON............5633  DEPARTURE......-505 TOTAL HEATING UNITS LAST SEASON TO DATE.......6025  DEPARTURE......-392 COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY................0  DEPARTURE........-1 TOTAL COOLING UNITS FOR THE MONTH................2  DEPARTURE........+1 TOTAL COOLING UNITS FOR THE SEASON...............2  DEPARTURE........-3 TOTAL COOLING UNITS LAST SEASON TO DATE..........0  DEPARTURE........+2 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................52 W   AT  2:42 P.M.                      AERO.........................53 W   AT  1:01 P.M.                     ASOS.........................52 W   AT  4:41 P.M.                    DAVIS........................53 W   AT  4:41 P.M. RMY 54 FASTEST MILE FOR YESTERDAY......................42 W   AT  4:54 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................38 W   AT  4:57 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................43 W   AT  4:57 P.M. AVERAGE WIND SPEED AND DIRECTION................21.4 W                                  ASOS.........................20.4                    DAVIS........................21.4 WNW [287 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace  DEPARTURE......-0.12                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.39  DEPARTURE......+0.40                          ASOS..............1.39 TOTAL PRECIPITATION FOR THE YEAR..........18.43  DEPARTURE......-1.11                          ASOS.............18.99 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M........Trace  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/.../..         25 ENE AERO 22 W   RMY N/A 04/21  53/33/43/-6/0.34/.../.../..         52 S   AERO 52 S   RMY 52 04/22  43/30/37/-12/0.00/0.0/.../..        51 W   AERO 50 W   RMY 50 04/23  55/29/42/-8/0.00/0.0/.../..         31 W   AERO 29 W   RMY N/A 04/24  42/37/40/-10/0.34/.../.../..        31 NNE AERO 29 NNE RMY 29 04/25  60/38/49/-1/0.00/0.0/.../..         25 S   AERO 24 S   RMY 24 04/26  51/38/45/-6/0.42/0.0/.../..         51 NE  AERO 50 NE  RMY 50 04/27  39/35/37/-14/0.94/T/.../..          54 NE  AERO 52 NNE RMY 55 04/28  48/35/42/-10/0.00/0.0/.../..        28 N   AERO 27 N   RMY N/A 04/29  55/35/45/-7/0.00/0.0/.../..         24 ENE AERO 23 ENE RMY 22 04/30  52/42/47/-5/0.01/0.0/.../..         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/-5/0/0.0/.../..            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 The low since midnight is 31F, the daily normal low is 46F   DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):   RECORDS FOR MAY 10 HIGH 93F IN 1896 LOW 29F  IN 1900 PRE 1.85 INS IN 1998 SNOW 2.8 INS 1977 (7.8 INS TOTAL 5/9-5/10 1977) PEAK GUST 64 MPH S IN 1990 RECORDS FOR MAY 11 HIGH 90F IN 1993 LOW 28F IN 1900 PRE 1.28 INS IN 1957 SNOW 1.0 INS IN 1907 (LATEST MEASURABLE SNOW ON RECORD) PEAK GUST 75e MPH NW IN 1945 TODAY'S REPORT PREPARED BY: Benjamin Turner