BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA SATURDAY, MAY 15, 2021 ALL TIMES ARE IN EASTERN STANDARD TIME SUNRISE: 0423E SUNSET:  1859E MORNING SUNSHINE GIVING WAY TO DEVELOPING CLOUDS AND EVEN SOME BRIEF RAIN SHOWERS... Plenty of sun this morning allowed for rapidly rising temperatures. As a matter of fact, the temperature spiked 11 degrees in 1 hour between 6 and 7 A.M. The wind during the morning was very light, even going calm for a time during mid morning. However, a sea-breeze developed late morning. This sea- breeze has created a boundary in which clouds have developed and even some showers. A couple of these showers have passed over the hill bringing 0.01" of rain. The temperature has of course responded to the sea-breeze and has dropped from the mid 70s to the upper 60s. The high so far today is 75F, which is 9 degrees above the normal high of 66F. The low since midnight is 55F, which is 7 degrees above the daily normal low of 48F. PRELIMINARY STATS FOR APRIL 2021 TEMPERATURE, Deg. F Avg. Max. 57.2 [+1.5] Avg. Min. 37.8 [+0.1] Mean      47.5 [+0.8] 24-hour corrected mean: 47.0 Max. for month: 75F on the 10th Min. for month: 23F on the 3rd HEATING DEGREE DAYS Total heating units:    519 [-32] Total for the season:  5341 [-694] Total for last season: 5521 PRECIPITATION, Inches Total: 4.89 [+0.45] Greatest in 24 hrs: 2.45 ins. on the 15-16th SNOWFALL, Inches Total: 3.6 [+0.6] Greatest in 24 hrs: 3.6 ins. on the 16th WIND, mph Avg. uncorrected wind speed: 12.1 mph Avg. corrected wind speed:   12.5 mph Prevailing wind direction:   WNW [16%] Peak gust and direction:     58 WNW on the 30th SUNSHINE: Campbell-Stokes card minutes: 12444 minutes of a possible 23250 or 54% Astronomical total minutes: 12904 minutes of a possible 24128 or 53% Today's Observations: 7 A.M. Weather: Scattered altocumulus/altocumulus castellanus, thin scattered cirrus Temperature: 68F; Dew Point: 33F; Relative Humidity: 27% Wind: ENE at 4 kts, wind light Sea-level pressure: 30.21 in. Hg; rising, then more slowly Visibility: 65 miles 6-hr Max temp: 68F 6-hr Min temp: 55F 24-hr Precip: 0.00 ins. 24-hr Snow: 0.0 ins. Snow Depth: 0.0 ins. BHO SA 1755 85 SCT 250 -SCT 65 230/68/33/0604/021/ VIRGA ALQDS THN K LYR ALNG HRZN SSW-WSW WND LGT/ 8/081 51013 10068 20055 10 A.M. Weather: Scattered cumulus, scattered altocumulus, thin scattered cirrus Temperature: 73F; Dew Point: 33F; Relative Humidity: 22% Wind: S @ 3 kts, wind light and variable Sea-level pressure: 30.22 in Hg; rising, then falling Visibility: 60 miles 3-hr Precip: 0.00 ins. 3-hr Snow: 0.0 ins. BHO SA 1455 55 SCT 100 SCT 250 -SCT 60 233/73/33/1803/022/ WND L/V/ 8/261 50003 1 P.M. Weather: Broken cumulus, broken altocumulus, thin broken cirrus, cumulonimbus SSE-S, virga all quadrants Temperature: 71F, Dew point: 38F; Relative Humidity: 30% Wind: ESE @ 9G15 kts Sea-level pressure: 30.19 in Hg; falling, then more rapidly Visibility: 60 miles 6-hr Max temp: 75F 6-hr Min temp: 65F 6-hr Precip: 0.01 ins. 6-hr Snow: 0.0 ins. Snow Depth: 0 ins. BHO SA 1755 E60 BKN 120 BKN 250 -BKN 60 223/71/38/1109G15/019/ CB SSE-S VIRGA ALQDS RW-B05E30/ 8/361 58010 6001/ 10075 20065 SUMMARY FOR FRIDAY, MAY 14, 2021 TEMPERATURE (DEGREES F) MAX.......76     NORMAL.....66 MIN.......49     NORMAL.....47 MEAN......63     NORMAL.....57 DEPARTURE FROM 30-YEAR (1981-2010) NORMAL....... +6 TOTAL DEPARTURE FOR THE MONTH...................-15 [-1.3 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL THRU JUN) TOTAL HEATING UNITS FOR YESTERDAY............... 2  DEPARTURE.......-7 TOTAL HEATING UNITS FOR THE MONTH..............159  DEPARTURE...... +8 TOTAL HEATING UNITS FOR THE SEASON............5500  DEPARTURE.....-686 TOTAL HEATING UNITS LAST SEASON TO DATE.......5712  DEPARTURE.....-212 COOLING DEGREE DAYS (SEASON JAN THRU DEC) TOTAL COOLING UNITS FOR YESTERDAY............... 0  DEPARTURE.......-1 TOTAL COOLING UNITS FOR THE MONTH............... 0  DEPARTURE.......-5 TOTAL COOLING UNITS FOR THE SEASON.............. 0  DEPARTURE.......-7 TOTAL COOLING UNITS LAST SEASON TO DATE......... 2  DEPARTURE.......-2 PEAK WIND GUST (MPH):                      420C/Official..............23 WNW  @  1:17 P.M.                      AEROVANE (south tower).....23 WNW  @  1:23 P.M.                      ASOS.......................23 W    @  1:17 P.M.                      DAVIS #1...................24 W    @  1:16 P.M.                      DAVIS #2 (south tower).....24 SSE  @  5:05 P.M.                      RMY........................25      @  1:16 P.M.                      VECTOR.....................24      @  1:16 P.M.                      MERLIN.....................23 FASTEST MILE: CONTACTING ANEMOMETER/OFFICIAL..................14 WNW @   5:27 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...................16 W   @   1:18 P.M. MAXIMUM 2-MINUTE DAVIS #1 AVERAGE...............18 W   @   1:18 P.M. MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............17 SSE @   5:16 A.M. MAXIMUM 2-MINUTE RMY AVERAGE....................15 W   @   1:15 P.M. MAXIMUM 2-MINUTE VECTOR AVERAGE.................15     @   1:15 P.M. AVERAGE WIND SPEED AND DIRECTION:                      CONTACTING/OFFICIAL...... 9.0 WNW [217 total miles]                      ASOS..................... 9.0                      DAVIS #1................. 9.3 WNW                      DAVIS #2................. 9.8 WNW                      RMY...................... 8.8 WNW                      VECTOR................... 9.4 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.............1.78  DEPARTURE....+0.07                              ASOS.............1.73 TOTAL PRECIPITATION FOR THE YEAR.............16.84  DEPARTURE....-3.42                               ASOS...........17.01 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   62/38/50/-3/0.06/0.0/659/78       31 WNW  AERO 35 WNW  RMY 40 05/02   76/48/62/+9/0.01/0.0/220/26       41 SW   AERO 41 SW   RMY 46 05/03   67/48/58/+5/0.07/0.0/400/47       21 E    AERO 20 E    RMY 20 05/04   50/44/47/-7/0.78/0.0/000/00       36 NNE  AERO 32 NNE  RMY 37 05/05   48/44/46/-8/0.45/0.0/000/00       18 ESE  AERO 14 ESE  RMY 17 05/06   64/45/55/+1/0.00/0.0/780/91       33 NW   AERO 38 NNW  RMY 39 05/07   61/43/52/-3/0.00/0.0/516/60       28 ESE  AERO 22 ESE  RMY 26 05/08   54/40/47/-8/0.00/0.0/069/08       24 SSW  AERO 23 SSW  RMY 25 05/09   66/42/54/-1/T/0.0/579/67          30 SW   AERO 29 SW   RMY 34 05/10   60/45/53/-2/0.39/0.0/.../..       21 W    AERO 20 W    RMY 20 05/11   63/45/54/-2/0.00/0.0/.../..       38 WNW  AERO 41 WNW  RMY 41 05/12   65/41/53/-3/0.00/0.0/.../..       28 NW   AERO M  M    RMY 31 05/13   69/45/57/+1/0.00/0.0/.../..       22 WNW  AERO 21 WNW  RMY 21 05/14   76/49/63/+8/0.00/0.0/.../..       23 WNW  AERO 23 WNW  RMY 25 05/15 The low since midnight is 55F, the daily normal low is 48F   DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated) RECORDS FOR MAY 15 HIGH 93F IN 1900 LOW 36F IN 1947,1985 PRECIP 1.63 INCHES IN 1978 PEAK GUST 53e MPH NE IN 1978, W 2002 RECORDS FOR MAY 16 HIGH 90F IN 1951 LOW 30F IN 1936 PRECIP 2.63 INCHES IN 1954 PEAK GUST 56e MPH NW IN 1952 TODAY'S REPORT PREPARED BY: Matt Douglas