BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, APRIL 17, 2020 ALL TIMES ARE IN EASTERN STANDARD TIME A CHILLY, BUT BRIGHT AND PLEASANT DAY ATOP GREAT BLUE HILL... We began the day under clear skies and chilly conditions. The overnight low bottomed out at 29F. The last time we reached the upper-20s was a few weeks ago on April 1st. Visibility was fair to start at 50 miles increasing to 70 miles by the 1 PM observation. Winds have been moderately busy clocking in so far today at 39 MPH. Our high temperature so far today is 49F, which is 7 degrees below our daily normal high temperature of 56F. The low since midnight is 29F, which is 9 degrees below the daily normal low of 38F. PRELIMINARY STATS FOR MARCH 2020 TEMPERATURE, Deg. F Avg. Max. 49.8 [+5.5] Avg. Min. 32.3 [+5.7] Mean      41.1 [+5.6] 24-hour corrected mean: 40.5 Max. for month: 72F on the 9th Min. for month: 15F on the 1st HEATING DEGREE DAYS Total heating units:    733 [-183] Total for the season:  4873 [-611] Total for last season: 5432 PRECIPITATION, Inches Total: 4.67 [-0.91] Greatest in 24 hrs: 2.37 ins. on the 23rd-24th SNOWFALL, Inches Total: 2.8 [-9.9] Greatest in 24 hrs: 1.6 ins. on the 23rd WIND, mph Avg. uncorrected wind speed: 12.6 mph Avg. corrected wind speed:   12.9 mph Prevailing wind direction:   W [12%] Peak gust and direction:     56 W on the 4th SUNSHINE: Campbell-Stokes card minutes: 11298 minutes of possible 21516 or 53% Astronomical total minutes: 11708 minutes of possible 22287 or 53% Today's Observations: 7 A.M. Weather: Clear (few cirrostratus) Temperature: 34F; Dew Point: 19F; Relative Humidity: 54% Wind: W at 11 kts Sea-level pressure: 30.20 ins. Hg: rising, then more slowly Visibility: 50 miles 6-hr Max temp: 34F 6-hr Min temp: 29F 24-hr Precip:   Trace 24-hr Snowfall: Trace BHO SA 1155 CLR 50 228/34/19/2811/020/ FEW CS S DSNT HZ ALQDS/ 8/005 51018 10034 20029 10 A.M. Weather: Scattered Cumulus (few cirrus) Temperature: 40F; Dew Point: 17F; Relative Humidity: 39% Wind: W at 17G24 kts Peak Wind: 35 MPH (30 kts) W at 8:38 A.M. Sea-level pressure: 30.19 ins. Hg: falling, then rising Visibility: 70 miles 3-hr Precip:   0.00 ins. 3-hr Snowfall: 0.0 ins. BHO SA 1455 50 SCT 70 220/40/17/2717G24/019/ FEW CI SE-SW PK WND 2730/1338/ 8/101 55008 1 P.M. Weather: Scattered Cumulus (few cirrus) Temperature: 49F; Dew Point: 13F; Relative Humidity: 23% Wind: WNW at 14G26 kts Peake Wind: 39 MPH (34 kts) WNW at 11:42 A.M. Sea-level pressure: 30.10 ins. Hg: falling, then more rapidly Visibility: 70 miles 6-hr Max temp: 49F 6-hr Min temp: 34F 6-hr Precip:   0.00 ins 6-hr Snowfall: 0.0 ins BHO SA 1755 50 SCT 70 192/49/13/2914G26/010/ FEW CI SE-SW PK WND 2934/1642/ 8/101 58028 10049 20034 SUMMARY FOR THURSDAY, APRIL 16, 2020 TEMPERATURE (DEGREES F) MAX.....47   NORMAL.....56 MIN.....32   NORMAL.....38 MEAN....40   NORMAL.....47 DEPARTURE FROM 30-YEAR NORMAL....................-7 TOTAL DEPARTURE FOR THE MONTH....................+9 [+0.4 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY...............25  DEPARTURE....... +7 TOTAL HEATING UNITS FOR THE MONTH..............327  DEPARTURE.......-10 TOTAL HEATING UNITS FOR THE SEASON............5200  DEPARTURE......-620 TOTAL HEATING UNITS LAST SEASON TO DATE.......5712  DEPARTURE......-512 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY....................33 WNW AT  5:59 P.M.                      AERO.........................33 WNW AT  5:48 P.M                     ASOS.........................32 WNW AT  6:00 P.M.                    DAVIS........................34 WNW AT 12:28 P.M. RMY 32 FASTEST MILE FOR YESTERDAY......................25 WNW AT  6:04 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................23 WNW AT  6:04 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..................25 WNW AT  6:01 P.M. AVERAGE WIND SPEED AND DIRECTION................12.6 W                                  ASOS.........................11.9                    DAVIS........................13.0 WNW [287 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....TRACE  DEPARTURE......-0.15                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........4.92  DEPARTURE......+2.26                          ASOS..............5.10 TOTAL PRECIPITATION FOR THE YEAR..........14.25  DEPARTURE......-2.41                          ASOS.............14.83 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M........TRACE  DEPARTURE.......-0.1 TOTAL SNOWFALL FOR THE MONTH..............TRACE  DEPARTURE.......-2.3 TOTAL SNOWFALL FOR THE SEASON..............27.6  DEPARTURE......-34.4 PRELIMINARY CLIMATE SUMMARY FOR MARCH 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 03/01  33/15/24/-7/0.00/0.0/676/100        28 WNW AERO 28 WNW RMY 27 03/02  52/24/38/+7/T/T/482/71              40 S   AERO 39 S   RMY 41 03/03  64/45/55/+23/0.05/0.0/361/53        30 S   AERO 30 S   RMY N/A 03/04  50/38/44/+12/0.04/0.0/561/82        56 W   AERO 56 W   RMY 58 03/05  51/32/42/+10/0.00/0.0/666/97        31 W   AERO 31 NW  RMY 32 03/06  47/30/39/+7/0.04/0.3/283/41         46 NE  AERO 45 NE  RMY 46 03/07  43/26/35/+2/0.03/0.5/534/77         42 N   AERO 43 N   RMY 44 03/08  53/26/40/+7/0.00/0.0/508/73         31 W   AERO 30 W   RMY 28 03/09  72/40/56/+23/0.00/0.0/685/98        32 SW  AERO 32 SW  RMY 31 03/10  68/49/59/+26/0.00/0.0/246/35        48 WSW AERO 46 WSW RMY 49 03/11  56/37/47/+13/0.00/0.0/501/71        31 WNW AERO M  M   RMY 21 03/12  46/31/39/+5/0.01/0.0/156/22         21 SE  AERO 18 SE  RMY N/A 03/13  59/38/49/+15/0.20/0.0/000/00        46 WNW AERO 44 WNW RMY 46 03/14  51/35/43/+8/0.00/0.0/613/86         37 W   AERO 36 W   RMY 35 03/15  47/28/38/+3/0.00/0.0/680/95         28 NW  AERO 28 NW  RMY N/A 03/16  36/22/29/-6/0.00/0.0/618/86         21 NE  AERO 21 ESE RMY 21 03/17  43/28/36/0/0.06/0.4/000/00          29 W   AERO 30 W   RMY 29 03/18  54/31/43/+7/0.00/0.0/609/84         26 S   AERO 26 S   RMY 26 03/19  43/37/40/+4/0.63/0.0/000/00         36 E   AERO 35 E   RMY 34 03/20  66/37/52/+15/0.03/0.0/000/00        48 W   AERO 48 W   RMY 46 03/21  55/29/42/+5/0.00/0.0/535/73         45 W   AERO 48 W   RMY N/A 03/22  36/23/30/-7/0.00/0.0/692/94         23 NE  AERO 24 NE  RMY 23 03/23  40/25/33/-5/1.74/1.6/037/05         38 NNE AERO 39 NNE RMY 38 03/24  48/33/41/+3/0.63/0.0/148/20         37 NNW AERO 37 NNW RMY N/A 03/25  41/35/38/0/0.03/0.0/000/00          28 ENE AERO 28 ENE RMY 27 03/26  51/30/41/+2/0.00/0.0/613/82         25 SSE AERO 26 SSW RMY N/A 03/27  61/41/51/+12/0.00/0.0/631/84        32 NW  AERO M  M   RMY 33 03/28  56/36/46/+7/0.15/0.0/309/41         22 S   AERO 21 E   RMY N/A 03/29  43/37/40/0/0.74/0.0/000/00          32 NE  AERO 33 NE  RMY 33 03/30  40/34/37/-3/0.21/0.0/000/00         33 NE  AERO 33 NE  RMY 33 03/31  40/29/35/-6/0.08/0.0/564/74         28 ENE AERO 26 ENE RMY N/A 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/.../..         28 NE  AERO 28 NE  RMY 30 04/02  46/35/41/0/.../0.0/.../..           39 NW  AER0 40 NW  RMY 41 04/03  42/38/40/-2/..../0.0/.../..         48 NE  AERO 53 NE  RMY 49 04/04  46/36/41/-1/..../0.0/.../..         38 NE  AERO 38 NE  RMY N/A 04/05  55/36/46/+3/T/0.0/.../..            22 S   AERO 21 S   RMY 21 04/06  61/40/51/+8/0.00/0.0/.../..         29 NW  AERO 30 NW  RMY 29 04/07  63/42/53/+10/0.00/0.0/.../..        29 W   AERO 30 W   RMY 28 04/08  50/41/46/+2/..../.../.../..         23 S   AERO 22 S   RMY 22 04/09  47/37/42/-2/..../.../.../..         58 W   AERO 58 W   RMY 56 04/10  47/35/41/-4/0.02/T/.../..           48 W   AERO 50 W   RMY 53 04/11  51/33/42/-3/0.00/0.0/.../..         38 WNW AERO 39 WNW RMY 40 04/12  60/33/47/+2/0.00/0.0/.../..         38 S   AERO 40 S   RMY N/A 04/13  59/50/55/+9/1.42/0.0/.../..         79 S   AERO 83 S   RMY 78 04/14  57/41/49/+3/0.00/0.0/.../..         41 W   AERO 40 W   RMY N/A 04/15  52/36/44/-3/0.02/0.0/.../..         37 W   AERO 36 W   RMY 37 04/16  47/32/40/-7/T/T/.../..              33 WNW AERO 33 WNW RMY 32 04/17 The low since midnight is 29F, daily normal minimum is 38F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):   RECORDS FOR APRIL 17 HIGH 93 IN 2002 LOW 21 IN 1908 PRECIP 1.68 IN 1954 SNOWFALL 1.0 IN. IN 1899 PEAK GUST 63 MPH ESE IN 2011 RECORDS FOR APRIL 18 HIGH 92 IN 1976 LOW 23 1887 PRECIP 1.48 IN 1954 SNOWFALL 3.7 IN. IN 1965 PEAK GUST 59 MPH S IN 1982 TODAY'S REPORT PREPARED BY: Andrew Swanson