Tuesday, April 21, 2020
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, APRIL 21, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME
NICE START TO THE DAY GIVES WAY TO CLOUDS, SHOWERS, AND
GUSTY WINDS…
The day started off with mainly clear skies and chilly
temperatures in the mid 30s. However clouds quickly
increased by mid to late morning with showers close
behind. So far the showers have been on the light side with
only 0.01″ of rain being measured through 1 pm.
A south wind has been increasing steadily into early this
afternoon with frequent gusts over 40mph and a peak gust
thus far of 52 mph at 12:23pm.
Our high temperature so far today is 53F, which is 5
degrees below our daily normal high temperature of 58F.
The low since midnight is 35F, which is 5 degrees below
the daily normal low of 40F.
Today’s Observations:
7 A.M.
Weather: Clear, few altocumulus castellanus distant SSW-NNW,
few cirrus distant NW-NE-ESE
Temperature: 42F; Dew Point: 28F; Relative Humidity: 57%
Wind: S at 14G23 kts
Sea-level pressure: 29.69 ins. Hg: rising, then falling
Visibility: 50 miles
6-hr Max temp: 42F
6-hr Min temp: 35F
24-hr Precip: 0.00 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 CLR 50 054/42/28/1714G23/969/ FEW ACC DSNT SSW-WNW
FEW CI DSNT NW-NE-ESE/ 8/081 50000 10042 20035
10 A.M.
Weather: Broken altocumulus/altocumulus castellanus, broken cirrus
Temperature: 51F; Dew Point: 28F; Relative Humidity: 40%
Wind: S at 19G30 kts, peak wind S 30 kts at 9:55am
Sea-level pressure: 29.62 ins. Hg: falling, then more rapidly
Visibility: 50 miles
3-hr Precip: 0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E100 BKN 250 BKN 50 032/51/28/1819G30/962/ FEW SCSL
SW-W-OVH RW S-SW-W MOVG NE VSBY 7 S-SW 15 W PK WND 1830/55/
8/581 58022
1 P.M.
Weather: Broken stratocumulus, broken altostratus, Overcast altocumulus,
light rain
Temperature: 49F; Dew Point: 39F; Relative Humidity: 68%
Wind: S at 24G38 kts, peak wind S 45kts at 12:23pm
Sea-level pressure: 29.51 ins. Hg: falling, then more rapidly
Visibility: 40 miles, 20 miles S-SW
6-hr Max temp: 53F
6-hr Min temp: 42F
6-hr Precip: 0.01 ins
6-hr Snowfall: 0.0 ins
BHO SA 1755 E25 BKN 50 BKN 90 OVC 40R- 993/49/39/1824G38/951/ VSBY
20 S-SW PCPN VRY LGT PK WND 1845/23/ 8/57/ 58039 6001 10053 20042
SUMMARY FOR MONDAY, APRIL 20, 2020
TEMPERATURE (DEGREES F)
MAX…..49 NORMAL…..58
MIN…..37 NORMAL…..40
MEAN….43 NORMAL…..49
DEPARTURE FROM 30-YEAR NORMAL………………. -6
TOTAL DEPARTURE FOR THE MONTH……………….-21 [-1.3 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………22 DEPARTURE……. +6
TOTAL HEATING UNITS FOR THE MONTH…………..425 DEPARTURE…….+20
TOTAL HEATING UNITS FOR THE SEASON…………5298 DEPARTURE……-591
TOTAL HEATING UNITS LAST SEASON TO DATE…….5743 DEPARTURE……-445
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..25 ENE AT 1:39 P.M.
AERO…………………….22 W AT 12:12 A.M
ASOS…………………….24 ENE AT 2:22 P.M.
DAVIS……………………24 WNW AT 1:23 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………….17 E AT 2:00 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 E AT 2:00 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………17 E AT 12:52 P.M.
AVERAGE WIND SPEED AND DIRECTION……………. 9.2 E
ASOS……………………. 9.2
DAVIS…………………… 9.8 N [359 deg.]
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……….5.66 DEPARTURE……+2.45
ASOS…………..5.84
TOTAL PRECIPITATION FOR THE YEAR……….14.99 DEPARTURE……-2.22
ASOS………….15.57
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0 DEPARTURE……. 0.0
TOTAL SNOWFALL FOR THE MONTH…………….4.3 DEPARTURE…….+1.7
TOTAL SNOWFALL FOR THE SEASON…………..31.9 DEPARTURE……-30.4
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 42/28/35/-6/0.00/0.0/008/01 28 NE AERO 28 NE RMY 30
04/02 46/35/41/0/…/0.0/000/00 39 NW AER0 40 NW RMY 41
04/03 42/38/40/-2/…./0.0/000/00 48 NE AERO 53 NE RMY 49
04/04 46/36/41/-1/…./0.0/278/36 38 NE AERO 38 NE RMY N/A
04/05 55/36/46/+3/T/0.0/039/05 22 S AERO 21 S RMY 21
04/06 61/40/51/+8/0.00/0.0/732/94 29 NW AERO 30 NW RMY 29
04/07 63/42/53/+10/0.00/0.0/649/83 29 W AERO 30 W RMY 28
04/08 50/41/46/+2/…./…/047/06 23 S AERO 22 S RMY 22
04/09 47/37/42/-2/…./…/000/00 58 W AERO 58 W RMY 56
04/10 47/35/41/-4/0.02/T/324/41 48 W AERO 50 W RMY 53
04/11 51/33/42/-3/0.00/0.0/730/92 38 WNW AERO 39 WNW RMY 40
04/12 60/33/47/+2/0.00/0.0/326/41 38 S AERO 40 S RMY N/A
04/13 59/50/55/+9/1.42/0.0/000/00 79 S AERO 83 S RMY 78
04/14 57/41/49/+3/0.00/0.0/…/.. 41 W AERO 40 W RMY N/A
04/15 52/36/44/-3/0.02/0.0/…/.. 37 W AERO 36 W RMY 37
04/16 47/32/40/-7/T/T/…/.. 33 WNW AERO 33 WNW RMY 32
04/17 49/29/39/-8/…./0.0/…/.. 41 W AERO 39 W RMY 41
04/18 37/31/34/-14/…./4.3/…/.. 29 NE AERO 25 NE RMY 25
04/19 60/31/46/-2/0.00/0.0/…/.. 40 SSW AERO 40 SSW RMY 41
04/20 49/37/43/-6/0.00/0.0/…/.. 25 ENE AERO 22 W RMY N/A
04/21 The low since midnight is 35F, daily normal minimum is 40F
DAILY RECORDS FOR APRIL 2020
4/13/2020
NEW PEAK GUST OF 79 MPH S, REPLACING THE OLD
RECORD OF 59 MPH SSW IN 1995
4/18/2020
NEW RECORD SNOWFALL OF 4.3 INS, REPLACING THE OLD
RECORD OF 3.7 INS IN 1965
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR APRIL 21
HIGH 85 IN 1923
LOW 22 IN 1908
PRECIP 3.18 IN. IN 1991
SNOWFALL 0.8 IN. IN 1947
PEAK GUST 76e MPH NE IN 1940
RECORDS FOR APRIL 22
HIGH 85 IN 1977, 2001
LOW 26 IN 1981
PRECIP 1.85 IN. IN 2000
SNOWFALL 3.0 IN. IN 1940
PEAK GUST 68e MPH NW IN 1945
TODAY’S REPORT PREPARED BY: Matt Douglas
