Thursday, April 29, 2021

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

THURSDAY, APRIL 29, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0443E
SUNSET:  1842E

RAINY WITH VERY LOW VISIBILITY IN THE
AFTERNOON HOURS….

We observed an overcast this morning with limited visibility
in the morning hours due to fog. Visibility quickly dropped
to a 1/16th mile and a light rain began quickly following
the 10 A.M. observation. Since then, we measured a 1/10th
inch of precipitation with hopefully more on the way. We
are normal for rainfall on the month, but at a 3.25 inch
deficit from the annual normal rain total. This leaves us
with an “abnormally dry” rating on the drought monitor,
with some areas in northern MA being in a moderate drought
situation.  

Wind wasn’t really a feature today, being light and variable
from the northeast on average.

The high so far today is 52F, this is 9 degrees below the
normal high of 61F. The low since midnight is 45F, which
is 2 degrees above the daily normal low of 43F.

Today’s Observations:

7 A.M.
Weather: Overcast altostratus
Temperature: 48F; Dew Point: 46F; Relative Humidity: 91%
Wind: NE at 4 kts, light and variable
Sea-level pressure: 29.82 in Hg, rising, then more slowly
Visibility: 5 miles, fog
6-hr Max temp: 49F
6-hr Min temp: 45F
24-hr Precip: Trace
24-hr Snow: 0.0 ins.
Snow Depth: 0.0 ins.
BHO SA 1155 80 OVC 5F 099/48/46/0404/982/ WND L/V/ 8/02/
70000 53010 10049 20045

10 A.M.
Weather: Overcast altostratus
Temperature: 51F; Dew Point: 50F; Relative Humidity: 96%
Wind: NE @ 4 kts, light and variable
Sea-level pressure: 29.78 in Hg; falling, then more slowly
Visibility: 5 miles, fog
3-hr Precip: 0.00 ins.
3-hr Snow: 0.00 ins.
BHO SA 1455 80 OVC 5F 085/51/50/0405/978/ WND L/V/ 8/02/
56014

1 P.M.
Weather: Light rain
Temperature: 48F, Dew point: 48F; Relative Humidity: 100%
Wind: NE @ 7 kts
Sea-level pressure: 29.73 in Hg; falling, then more slowly
Visibility: 1/16 mile, fog
6-hr Max temp: 52F
6-hr Min temp: 48F
6-hr Precip: 0.09 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 X W2 1/16R-F 068/48/48/0407/973/ R-CTD/ 8////
6009/ 58017 10052 20048

SUMMARY FOR WEDNESDAY, APRIL 28, 2021

TEMPERATURE (DEGREES F)
MAX…….63     NORMAL…..61
MIN…….46     NORMAL…..42
MEAN……55     NORMAL…..52

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……. +3
TOTAL DEPARTURE FOR THE MONTH……………….+33 [+1.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………10  DEPARTURE…….-3
TOTAL HEATING UNITS FOR THE MONTH…………..489  DEPARTURE……-36
TOTAL HEATING UNITS FOR THE SEASON…………5311  DEPARTURE…..-698
TOTAL HEATING UNITS LAST SEASON TO DATE…….5483  DEPARTURE…..-172

PEAK WIND GUST (MPH):
                     420C/Official…………..18 ENE @  1:28 P.M.
                     AEROVANE (south tower)…..21 WNW @  1:41 A.M
                     ASOS…………………..21 ENE @  1:27 P.M
                     DAVIS #1……………….20 E   @  1:28 P.M
                     DAVIS #2 (south tower)…..19 WNW @  1:37 A.M
                     RMY……………………20     @  1:27 P.M
                     VECTOR…………………21     @  1:27 P.M
                     MERLIN…………………19

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………15 ENE @  1:32 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….15 E   @  1:28 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………15 E   @  1:29 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………17 WNW @  1:29 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..14 ESE @  1:26 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..15     @  1:35 A.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL…….7.6 SE [182 total miles]                     ASOS………………….7.7
                     DAVIS #1………………8.2 ESE
                     DAVIS #2………………8.2 E
                     RMY…………………..7.7 SE
                     VECTOR………………..8.1

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……TRACE  DEPARTURE….-0.14
                             ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….4.39  DEPARTURE….+0.10
                             ASOS………….4.29
TOTAL PRECIPITATION FOR THE YEAR………….14.56  DEPARTURE….-3.72
                              ASOS………..14.80

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…..+0.6
TOTAL SNOWFALL FOR THE SEASON……………..76.2  DEPARTURE….+14.0

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/0.0/415/52         31 NE   AERO 30 NE   RMY 33
04/14   56/42/49/+3/0.00/0.0/729/91      22 ESE  AERO 23 ESE  RMY 22
04/15   51/37/44/-3/0.30/0.0/016/02      26 ESE  AERO 25 ESE  RMY 28
04/16   39/31/35/-12/2.22/3.6/000/00     48 NNW  AERO 58 NNW  RMY 58
04/17   45/34/40/-7/0.07/T/040/05        27 NNW  AERO 30 NNW  RMY 29
04/18   60/38/49/+1/0.00/0.0/666/82      28 NW   AERO 28 NW   RMY 31
04/19   66/44/55/+7/T/0.0/…/..         22 SSW  AERO 25 SSW  RMY 28
04/20   72/45/59/+10/0.00/0.0/…/..     38 SW   AERO 37 WSW  RMY 40
04/21   68/32/50/+1/0.48/*T/…/..       45 S    AERO 51 S    RMY 51 TSTM
04/22   44/28/36/-13/T/T/…/..          54 W    AERO 55 W    RMY 59
04/23   58/32/45/-5/0.00/0.0/…/..      47 W    AERO 48 W    RMY 52
04/24   70/44/57/+7/0.00/0.0/…/..      33 WNW  AERO 37 WNW  RMY 55
04/25   54/44/49/-1/0.20/0.0/…/..      23 NNE  AERO 20 SSW  RMY 24
04/26   55/40/48/-3/0.00/0.0/…/..      39 NW   AERO 40 NW   RMY 43
04/27   67/38/53/+2/T/0.0/…/..         26 W    AERO 28 WNW  RMY 28
04/28   63/46/55/+3/…./…/…/..      18 ENE  AERO 21 WNW  RMY 20

04/29   The low since midnight is 45F, the daily normal low is 43F

*Trace of frozen on 04/21 was hail, 1/8″ diameter, this does not
count as snowfall.

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

RECORDS FOR APRIL 29
HIGH 85 IN 1974
LOW 26 IN 1909
PRECIP 1.65 IN 1923
SNOWFALL 1.0 IN. IN 1987
PEAK GUST 55 MPH WNW IN 2010

RECORDS FOR APRIL 30
HIGH 86 IN 1942
LOW 30 IN 1931
PRECIP 1.41 IN 1991
SNOWFALL 0.3 IN. IN 1909
PEAK GUST 64e MPH NW IN 1978

TODAY’S REPORT PREPARED BY: Benjamin Turner