BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, MAY 13, 2020 ALL TIMES ARE IN EASTERN STANDARD TIME AN ALMOST CLEAR DAY WITH GREAT VISIBILITY AND A NEAR FREEZING OVERNIGHT LOW.... Today we observed a few fair weather cumulus with skies being completely clear at the 7 A.M. observation. There was a good westerly breeze, with a max gust of 38 mph. The overnight low was 32.4F, setting a new record for the daily minimum temperature. The old record was 35F, set in 2005. Conditions remain dry, with a humidity of 22% by 1 P.M. The high so far today is 57F, this is 9 degrees below the daily normal high of 66F. The low since midnight is 32F, which is 15 degrees below the daily normal low of 47F. The temperature of 32F this morning was also the second latest freezing temperature ever observed at Blue Hill, behind only 30F on May 16th, 1936. BHO Latest Freezing Temperature, deg F (1885-2020): 1) 30F on 16 May 1936 2) 32F on 13 May 2020 3) 29F on 12 May 1907 30F on 12 May 1963 5) 28F on 11 May 1900 31F on 11 May 1907 31F on 11 May 1913 30F on 11 May 1923 9) 29F on 10 May 1900 31F on 10 May 1902 31F on 10 May 1947 32F on 10 May 1966 32F on 10 May 1977 31F on 10 May 2020 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: Clear Temperature: 42F; Dew Point: 22F; Relative Humidity: 22% Wind: WNW at 9 kts   Sea-level pressure: 30.21 ins. Hg: rising Visibility: 80 miles 6-hr Max temp: 57F 6-hr Min temp: 42F 24-hr Precip:  0.00 ins. 24-hr Snowfall: 0.0 ins. BHO SA 1155 CLR 80 231/42/22/2909/021/ 52023 10057 20042 10 A.M. Weather: Few cumulus Temperature: 51F; Dew Point: 21F; Relative Humidity: 30% Wind: WNW at 11G27 kts, peak wind 35 mph at 9:39 A.M. Sea-level pressure: 30.20 ins. Hg: falling Visibility: 80 miles 3-hr Precip:  0.00 ins. 3-hr Snowfall: 0.0 ins. BHO SA 1455 CLR 80 228/51/21/3011G27/020/ FEW CU ALQDS PK WND 2830/39/ 8/100 58003 1 P.M. Weather: Few cumulus Temperature: 56F; Dew Point: 18F; Relative Humidity: 22% Wind: W at 14G26 kts, peak wind 33 mph at 12:29 P.M. Sea-level pressure: 30.16 ins. Hg: falling Visibility: 75 miles 6-hr Max temp: 57F 6-hr Min temp: 42F 6-hr Precip:  0.00 ins. 6-hr Snowfall: 0.0 ins. BHO SA 1755 CLR 75 214/56/18/2814G26/016/ FEW CU ALQDS PK WND 2929/29/ 8/100 58014 10057 20042 SUMMARY FOR TUESDAY, MAY 12, 2020 TEMPERATURE (DEGREES F) MAX.....55   NORMAL.....65 MIN.....37   NORMAL.....47 MEAN....46   NORMAL.....56 DEPARTURE FROM 30-YEAR NORMAL..................-10 TOTAL DEPARTURE FOR THE MONTH..................-33 [-3.0 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY...............19  DEPARTURE.......+10 TOTAL HEATING UNITS FOR THE MONTH..............162  DEPARTURE.......+29 TOTAL HEATING UNITS FOR THE SEASON............5683  DEPARTURE......-484 TOTAL HEATING UNITS LAST SEASON TO DATE.......6064  DEPARTURE......-381 COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY................0  DEPARTURE........ 0 TOTAL COOLING UNITS FOR THE MONTH................2  DEPARTURE........-2 TOTAL COOLING UNITS FOR THE SEASON...............2  DEPARTURE........-4 TOTAL COOLING UNITS LAST SEASON TO DATE..........0  DEPARTURE........+2 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................37 W   AT  3:55 P.M.                      AERO.........................37 W   AT  4:00 P.M.                     ASOS.........................40 WNW AT  4:18 P.M.                    DAVIS........................39 W   AT  3:50 P.M. RMY 37 FASTEST MILE FOR YESTERDAY......................29 W   AT  3:58 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................29 WNW AT  3:58 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................31 W   AT  3:58 P.M. AVERAGE WIND SPEED AND DIRECTION................17.3 WNW                                  ASOS.........................16.5                    DAVIS........................17.6 WNW [288 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE......-0.13                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.61  DEPARTURE......+0.14                          ASOS..............1.60 TOTAL PRECIPITATION FOR THE YEAR..........18.65  DEPARTURE......-1.37                          ASOS.............19.20 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 The low since midnight is 32F, the daily normal low is 47F   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 12 HIGH 88F IN 2001 LOW 29F IN 1907 PRECIP 1.49 INCHES IN 1968 PEAK GUST 76 MPH S IN 1974 RECORDS FOR MAY 13 HIGH 85F IN 1947 LOW 35F IN 1914, 2005 PRECIP 2.39 INCHES IN 2006 PEAK GUST 49 MPH NNW IN 1965 TODAY'S REPORT PREPARED BY: Benjamin Turner