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

MONDAY, APRIL 19, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0457E
SUNSET:  1831E

SUNNY START, CLOUDS BUILDING WITH THE HEATING OF THE DAY....

Plenty of sunshine this morning has given way to growing
cumulus clouds as the heating of the day has allowed
for convection to take place.

Not much in the way of wind today with an average speed
of only around 5 mph since 7 A.M.

Visibility has been hanging around the 60 mile mark today.

All in all not a bad Patriots Day here at Blue Hill!

The high so far today is 64F, this is 7 degrees above the
normal high of 57F. The low since midnight is 44F, which
is 5 degrees above the daily normal low of 39F.


Today's Observations:

7 A.M.
Weather: Thin scattered cirrus
Temperature: 49F; Dew Point: 39F; Relative Humidity: 68%
Wind: WNW at 6 kts
Sea-level pressure: 29.87 in Hg, rising, then steady  
Visibility: 60 miles
6-hr Max temp: 49F
6-hr Min temp: 44F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0.0 ins.
BHO SA 1155 250 -SCT 60 114/49/39/3006/987/ 8/001 51005
10049 20044

10 A.M.
Weather: Scattered cumulus, thin scattered cirrus
Temperature: 58F; Dew Point: 35F; Relative Humidity: 41%
Wind: W @ 5 kts, wind light
Sea-level pressure: 29.86 in Hg; rising then falling
Visibility: 60 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 45 SCT 250 -SCT 60 112/58/35/2804/986/ WND LGT/
8/201 58002

1 P.M.
Weather: Broken cumulus, few moderate cumulus all quadrants
Temperature: 63F, Dew point: 31F; Relative Humidity: 29%
Wind: NW @ 5 kts, wind light and variable
Sea-level pressure: 29.82 in Hg; falling, then more rapidly
Visibility: 60 miles
6-hr Max temp: 64F
6-hr Min temp: 49F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 E45 BKN 60 097/63/31/3205/982/ MDT CU ALQDS
WND L/V/ 8/200 58015 10064 20049


SUMMARY FOR SUNDAY, APRIL 18, 2021

TEMPERATURE (DEGREES F)
MAX.......60     NORMAL.....57
MIN.......38     NORMAL.....39
MEAN......49     NORMAL.....48

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL....... +1
TOTAL DEPARTURE FOR THE MONTH...................+25 [+1.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............16  DEPARTURE.......-1
TOTAL HEATING UNITS FOR THE MONTH..............346  DEPARTURE......-26
TOTAL HEATING UNITS FOR THE SEASON............5168  DEPARTURE.....-687
TOTAL HEATING UNITS LAST SEASON TO DATE.......5257  DEPARTURE......-89

PEAK WIND GUST (MPH):
                     420C/Official..............28 NW  @  3:37 P.M.
                     AEROVANE (south tower).....28 NW  @  3:22 P.M.
                     ASOS.......................28 NW  @  3:35 P.M.
                     DAVIS #1...................28 NW  @  3:34 P.M.
                     DAVIS #2 (south tower).....28 NW  @  1:39 P.M.
                     RMY........................31     @  3:19 P.M.
                     VECTOR.....................33     @  3:23 P.M.
                     MERLIN.....................29

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL..................22 NW  @  3:26 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...................20 WNW @  3:24 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE...............21 NW  @  3:25 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............21 WNW @  1:43 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE....................19 NW  @  3:23 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE.................21     @  3:22 P.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL...... 8.6 WNW [207 total miles]
                     ASOS..................... 8.3
                     DAVIS #1................. 9.0 NW  
                     DAVIS #2................. 9.2 NW
                     RMY...................... 8.3 NW
                     VECTOR..................  8.9

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.............3.53  DEPARTURE....+0.60
                             ASOS.............3.42
TOTAL PRECIPITATION FOR THE YEAR.............13.70  DEPARTURE....-3.22
                              ASOS...........13.93

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M...........0.0  DEPARTURE.....-0.1
TOTAL SNOWFALL FOR THE MONTH ..................3.6  DEPARTURE.....+1.1
TOTAL SNOWFALL FOR THE SEASON.................76.2  DEPARTURE....+14.5


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/000/00        44 NW   AERO 51 NW   RMY 49
04/02   37/24/31/-10/0.00/0.0/614/80     28 NW   AERO 32 NNW  RMY 30
04/03   48/23/36/-6/0.00/0.0/755/98      24 NW   AERO 25 NW   RMY 26
04/04   58/33/46/+4/0.00/0.0/734/95      38 NNW  AERO 41 NNW  RMY 41
04/05   57/41/49/+6/T/T/031/04           41 NNW  AERO 48 NNW  RMY 50
04/06   61/40/51/+8/0.00/0.0/412/53      26 NNW  AERO 25 NNW  RMY 31
04/07   57/41/49/+6/0.00/0.0/391/50      23 ENE  AERO 21 ENE  RMY 22
04/08   59/43/51/+7/0.00/0.0/745/95      22 ENE  AERO 22 ENE  RMY 24
04/09   69/42/56/+12/0.00/0.0/707/90     24 S    AERO  M   M  RMY 26
04/10   75/43/59/+14/0.00/0.0/576/73     26 SSW  AERO 28 SSW  RMY 30
04/11   53/40/47/+2/T/0.0/000/00         33 ENE  AERO 33 ENE  RMY 34
04/12   46/37/42/-3/0.05/0.0/000/00      36 ENE  AERO 37 ENE  RMY 41
04/13   56/37/47/+1/T/0.0/.../..         31 NE   AERO 30 NE   RMY 33
04/14   56/42/49/+3/0.00/0.0/.../..      22 ESE  AERO 23 ESE  RMY 22
04/15   51/37/44/-3/0.30/0.0/.../..      26 ESE  AERO 25 ESE  RMY 28
04/16   39/31/35/-12/2.22/3.6/.../..     48 NNW  AERO 58 NNW  RMY 58
04/17   45/34/40/-7/0.07/T/.../..        27 NNW  AERO 30 NNW  RMY 29
04/18   60/38/49/+1/0.00/0.0/.../..      28 NW   AERO 28 NW   RMY 31

04/19   The low since midnight is 44F, the daily normal low is 39F


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

RECORDS FOR APRIL 19
HIGH 94 IN 1976 [RECORD FOR MONTH]
LOW 21 IN 1890
PRECIP 1.71 IN 1969
SNOWFALL 1.3 IN. IN 1967
PEAK GUST 66 MPH E IN 1984

RECORDS FOR APRIL 20
HIGH 88 IN 1927
LOW 18 IN 1897
PRECIP 1.14 IN 1972
SNOWFALL 2.5 IN. IN 1904, 1972
PEAK GUST 76 MPH WNW IN 1963

TODAY'S REPORT PREPARED BY: Matt Douglas