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

THURSDAY, APRIL 15, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0503E
SUNSET:  1826E

CLOUDS THICKEN THIS MORNING WITH RAIN ARRIVING EARLY THIS
AFTERNOON...

After a brilliant sunrise this morning, clouds quickly
increased and thickened leaving us with yet another cloudy
day for this week. We've had a couple of light rain showers
in the last couple of hours, however the steadier rain is
approaching the region and should arrive by late afternoon.

This rain will be welcomed as it's been dry not only
recently, but for the year to date. The month had a -1.39"
deficit while for the year to date we're looking at a
-5.21" deficit.

This morning's drought monitor has most of the state as
abnormally dry, with north central Massachusetts now in
moderate drought territory.

Onshore flow is the theme again today, as such temperatures
remain on the cool side!

The high so far today is 52F, this is 4 degrees below the
normal high of 56F. The low since midnight is 42F, which is
4 degrees above the daily normal low of 38F.


Today's Observations:

7 A.M.
Weather: Overcast Altocumulus/Castellanus, few breaks in overcast
distant N-E, stratus layer distant SSW-WNW
Temperature: 45F; Dew Point: 34F; Relative Humidity: 65%
Wind: SE at 10 kts
Sea-level pressure: 29.88 in Hg, falling, then more slowly  
Visibility: 30 miles, hazy
6-hr Max temp: 45F
6-hr Min temp: 42F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 E95 OVC 30 117/45/34/1310/988/ FEW BINOVC DSNT N-E
ST LYR DSNT SSW-WNW HAZY/ 8/78/ 56008 10045 20042

10 A.M.
Weather: Broken Stratocumulus, overcast altocumulus
Temperature: 50F; Dew Point: 29F; Relative Humidity: 43%
Wind: SE @ 8 kts
Sea-level pressure: 29.86 in Hg; steady, then falling
Visibility: 30 miles, hazy
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 E35 BKN 80 OVC 30 112/50/29/1308/986/ HAZY/ 8/57/ 58005

1 P.M.
Weather: Overcast stratocumulus
Temperature: 50F, Dew point: 30F; Relative Humidity: 45%
Wind: ESE @ 9G17 kts
Sea-level pressure: 29.81 in Hg; falling, then more rapidly
Visibility: 25 miles, hazy
6-hr Max temp: 52F
6-hr Min temp: 45F
6-hr Precip: Trace
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 E35 OVC 25 096/50/30/1109G17/981/ RW-B25E28 HAZY/
8/5// 58016 6000/ 10052 20045


SUMMARY FOR WEDNESDAY, APRIL 14, 2021

TEMPERATURE (DEGREES F)
MAX.......56     NORMAL.....55
MIN.......42     NORMAL.....37
MEAN......49     NORMAL.....46

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL....... +3
TOTAL DEPARTURE FOR THE MONTH...................+46 [+3.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............16  DEPARTURE...... -3
TOTAL HEATING UNITS FOR THE MONTH..............254  DEPARTURE......-46
TOTAL HEATING UNITS FOR THE SEASON............5076  DEPARTURE.....-708
TOTAL HEATING UNITS LAST SEASON TO DATE.......5154  DEPARTURE......-78

PEAK WIND GUST (MPH):
                     420C/Official..............22 ESE @  3:49 P.M.
                     AEROVANE (south tower).....23 ESE @  4:21 P.M.
                     ASOS.......................20 E   @ 12:22 P.M.
                     DAVIS #1...................21 S   @  5:25 P.M.
                     DAVIS #2 (south tower).....21 ESE @  4:22 P.M.
                     RMY........................22     @  5:25 P.M.
                     VECTOR.....................23     @  5:23 P.M.
                     MERLIN.....................20

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL..................15 SE  @  5:24 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...................15 E   @  3:49 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE...............16 ESE @  3:49 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............17 SE  @  5:27 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE....................15 SE  @  3:47 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE.................16     @  3:46 P.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL....... 8.9 ESE [213 total miles]
                     ASOS...................... 9.0  
                     DAVIS #1.................. 9.5 SE  
                     DAVIS #2.................. 9.4 ESE
                     RMY....................... 8.9 SSE
                     VECTOR.................... 9.3

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.......0.00  DEPARTURE....-0.15
                             ASOS.............0.00
TOTAL PRECIPITATION FOR THE MONTH.............0.94  DEPARTURE....-1.39
                             ASOS.............0.92
TOTAL PRECIPITATION FOR THE YEAR.............11.11  DEPARTURE....-5.21
                              ASOS...........11.43

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M...........0.0  DEPARTURE.... -0.1
TOTAL SNOWFALL FOR THE MONTH ................TRACE  DEPARTURE.....-2.1
TOTAL SNOWFALL FOR THE SEASON.................72.6  DEPARTURE....+11.3


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   The low since midnight is 42F, the daily normal low is 38F


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

RECORDS FOR APRIL 15
HIGH 81 IN 1896
LOW 23 IN 1943
PRECIP 1.75 IN. IN 2007
SNOWFALL 1.0 IN. IN 1916, 1962
PEAK GUST 66 MPH E IN 2007      

RECORDS FOR APRIL 16
HIGH 89 IN 2012
LOW 23 IN 1943
PRECIP 2.63 IN. IN 2018
SNOWFALL 2.0 IN. IN 1904, 1962
PEAK GUST 73 MPH E IN 2007

TODAY'S REPORT PREPARED BY: Matt Douglas