BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

SUNDAY, APRIL 4, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0522E
SUNSET:  1813E

A NICE DAY FOR EASTER ATOP GREAT BLUE HILL....

We observed fair and more seasonable weather today. Visibility
is 75 miles on average with very few clouds in the sky. The
weather is again very dry, with a relative humidity of 20%
measured at the 10 A.M. observation. Wind is northwesterly
with an average speed of 10 mph and no notable gusts. This
is a cool breeze with more seasonable temperatures in the
afternoon hours.

The high today so far today is 56F, this is 5 degrees above
the normal high of 51F. The low since midnight is 33F, which
is the same as the daily normal low.

PRELIMINARY STATS FOR MARCH 2021

TEMPERATURE, Deg. F
Avg. Max. 50.2 [+5.9]
Avg. Min. 29.1 [+2.5]
Mean      39.7 [+4.2]
24-hour corrected mean: 39.2
Max. for month: 71F on the 11th
Min. for month: 10F on the 2nd

HEATING DEGREE DAYS
Total heating units:    777 [-139]
Total for the season:  4822 [-662]
Total for last season: 5484

PRECIPITATION, Inches
Total: 2.17 [-3.41]
Greatest in 24 hrs: 0.80 ins. on the 18th and 28th

SNOWFALL, Inches
Total: 0.2 [-12.5]
Greatest in 24 hrs: 0.1 ins. on the 2nd and 14th

WIND, mph
Avg. uncorrected wind speed: 13.8 mph
Avg. corrected wind speed:   14.2 mph
Prevailing wind direction:   WNW [22%]
Peak gust and direction:     69 WNW on the 1st

SUNSHINE:
Campbell-Stokes card minutes: 14328 out of 21516 or 67%
Astronomical total minutes: 14835 out of 22265 or 67%

Today's Observations:

7 A.M.
Weather: Clear, few cumulus and cirrus
Temperature: 36F; Dew Point: 13F; Relative Humidity: 38%
Wind: NW @ 7 kts
Sea-level pressure: 30.11 in Hg, rising then falling
Visibility: 75 miles
6-hr Max temp: 36F
6-hr Min temp: 33F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 CLR 75 196/36/13/3207/011/ FEW CU/CI ALQDS/
8/101 57009 10036 20033

10 A.M.
Weather: Clear, few cirrus
Temperature: 49F; Dew Point: 12F; Relative Humidity: 22%
Wind: NW @ 8 kts
Sea-level pressure: 30.06 in Hg; falling steadily
Visibility: 75 miles
3-hr Precip: 0.00 ins
3-hr Snow: 0.0 ins.
BHO SA 1455 CLR 75 181/49/12/3108/006/ FEW CI ALQDS/ 8/001
58015

1 P.M.
Weather: Scattered cirrostratus
Temperature: 55F, Dew point: 13F; Relative Humidity: 19%
Wind: NW @ 7 kts
Sea-level pressure: 29.98 in Hg; falling steadily
Visibility: 75 miles
6-hr Max temp: 56F
6-hr Min temp: 36F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 250 SCT 75 146/55/13/3107/998/ 8/005 58035
10056 20036


SUMMARY FOR SATURDAY, APRIL 3, 2021

TEMPERATURE (DEGREES F)
MAX.......48     NORMAL.....51
MIN.......23     NORMAL.....33
MEAN......36     NORMAL.....42

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL......-6
TOTAL DEPARTURE FOR THE MONTH.................-14 [-4.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............29  DEPARTURE.......+6
TOTAL HEATING UNITS FOR THE MONTH...............85  DEPARTURE......+14
TOTAL HEATING UNITS FOR THE SEASON............4907  DEPARTURE.....-648
TOTAL HEATING UNITS LAST SEASON TO DATE.......4952  DEPARTURE......-45

PEAK WIND GUST (MPH):
                     420C/Official..............24 NW  @  1:13 P.M.
                     AEROVANE (south tower).....25 NW  @  1:47 P.M.
                     ASOS.......................24 NW  @ 11:31 A.M.
                     DAVIS #1...................26 NW  @  1:48 P.M.
                     DAVIS #2 (south tower).....26 NW  @  1:48 P.M.
                     RMY........................26     @ 11:29 A.M.
                     VECTOR.....................28     @ 11:30 A.M.
                     MERLIN.....................26

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL..................19 WNW @  1:13 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...................17 WNW @  1:50 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE...............19 WNW @ 11:15 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............19 WNW @ 11:15 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE....................18 NW  @  1:47 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE.................18     @ 11:29 A.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL.......8.4 NW [202 total miles]
                     ASOS......................8.5  
                     DAVIS #1..................8.7 NNW  
                     DAVIS #2..................8.7 NNW
                     RMY.......................8.2 NNW
                     VECTOR....................8.8

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.......0.00  DEPARTURE....-0.17
                             ASOS.............0.00
TOTAL PRECIPITATION FOR THE MONTH.............0.89  DEPARTURE....+0.38
                             ASOS.............0.87
TOTAL PRECIPITATION FOR THE YEAR.............11.06  DEPARTURE....-3.44
                              ASOS...........11.38

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M...........0.0  DEPARTURE.... -0.2
TOTAL SNOWFALL FOR THE MONTH ..................0.0  DEPARTURE.....-0.4
TOTAL SNOWFALL FOR THE SEASON.................72.6  DEPARTURE....+12.8


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   42/24/33/+2/0.13/T/020/03        69 WNW  AERO 78 WNW  RMY 78
03/02   27/10/19/-12/T/0.1/679/100       63 WNW  AERO 71 WNW  RMY 69
03/03   45/19/32/0/0.00/0.0/375/55       30 W    AERO 30 W    RMY 34
03/04   38/22/30/-2/0.00/0.0/520/76      46 NW   AERO 51 NW   RMY 53
03/05   31/18/25/-7/0.00/0.0/549/80      39 WNW  AERO 44 NW   RMY 45
03/06   33/15/24/-8/0.00/0.0/675/98      28 WNW  AERO 29 WNW  RMY 30
03/07   35/15/25/-8/0.00/0.0/686/99      21 NW   AERO 22 NW   RMY 23
03/08   38/19/29/-4/T/T/389/56           20 NW   AERO 20 NW   RMY 21
03/09   56/30/43/+10/T/T/628/90          32 WNW  AERO 35 WNW  RMY 37
03/10   54/32/43/+10/0.00/0.0/666/95     29 SSW  AERO 29 SSW  RMY 31
03/11   71/35/53/+19/0.00/0.0/218/31     41 SSW  AERO 43 SSW  RMY 46
03/12   62/42/52/+18/0.00/0.0/614/87     52 WNW  AERO 59 WNW  RMY 57
03/13   46/27/37/+3/0.00/0.0/696/98      53 WNW  AERO 59 WNW  RMY 57
03/14   45/19/32/-3/0.01/0.1/449/63      51 WNW  AERO 58 NW   RMY 58
03/15   27/12/20/-15/0.00/0.0/694/97     48 NW   AERO 47 NW   RMY 54
03/16   37/13/25/-10/0.00/0.0/352/49     22 NNW  AERO 22 NNW  RMY 23
03/17   52/27/40/+4/0.00/0.0/483/67      28 S    AERO 25 S    RMY 29
03/18   46/34/40/+4/0.80/T/000/00        38 NE   AERO 40 NE   RMY 42
03/19   39/26/33/-3/T/T/683/94           37 N    AERO 38 N    RMY 41
03/20   58/24/41/+4/0.00/0.0/701/96      23 W    AERO 23 W    RMY 27
03/21   62/39/51/+14/0.00/0.0/704/96     22 S    AERO 23 S    RMY 25
03/22   62/36/49/+12/0.00/0.0/698/95     21 S    AERO 18 S    RMY 22
03/23   65/38/52/+14/0.00/0.0/568/77     22 ESE  AERO 18 SE   RMY 21
03/24   63/44/54/+16/0.01/0.0/163/22     22 SSE  AERO 21 SSE  RMY 21
03/25   67/49/58/+20/0.10/0.0/201/27     25 S    AERO 26 S    RMY 26
03/26   63/48/56/+17/0.01/0.0/127/17     58 W    AERO 67 W    RMY 63
03/27   63/40/52/+13/0.00/0.0/608/81     39 WNW  AERO 41 WNW  RMY 44
03/28   56/37/47/+8/0.80/0.0/000/00      40 S    AERO 41 S    RMY 46
03/29   50/35/43/+3/T/0.0/718/95         58 WNW  AERO 62 WNW  RMY 63
03/30   58/31/45/+5/0.00/0.0/720/95      36 S    AERO 36 S    RMY 37
03/31   66/43/55/+14/0.31/0.0/251/33     41 SSW  AERO 45 S    RMY 44


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   56/30/43/+2/0.89/T/.../..        44 NW   AERO 51 NW   RMY 49
04/02   37/24/31/-10/..../.../.../..     28 NW   AERO 32 NNW  RMY 30
04/03   48/23/36/-6/0.00/0.0/.../..      24 NW   AERO 25 NW   RMY 26

04/04   The low since midnight is 33F, the daily normal low is 33F


DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)

RECORDS FOR APRIL 4
HIGH 76 IN 2010
LOW 12 IN 1954
PRECIP 1.45 IN. IN 1987
SNOWFALL 7.3 IN. IN 2016
PEAK GUST 80 MPH WNW IN 1963

RECORDS FOR APRIL 5
HIGH 81 IN 1928
LOW 15 IN 1995
PRECIP 2.15 IN. IN 1987
SNOWFALL 4.0 IN. IN 1898
PEAK GUST 76 MPH WNW IN 1963

TODAY'S REPORT PREPARED BY: Benjamin Turner