Thursday, April 30, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, APRIL 30, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

AN OVERCAST DAY WITH A LITTLE RAIN IN
THE MORNING HOURS….

We observed light rain from 6 A.M. to 11 A.M. today,
only leaving 0.01 inches in the gauge by the 1 P.M.
observation. Visibility was hindered by a distant
fog that gradually decreased as the day went on.
Only 5 miles were seen at 7 A.M., and 25 miles at
noontime. Wind was southeasterly with a max gust
of 28 mph and an average speed of 15 mph. A fog
bank was seen moving into Boston, decreasing
visibility to the north to 10 miles by 4 P.M.

The high so far today is 48F, this is 13 degrees
below our daily normal high temperature of 61F.
The low since midnight is 42F, which is a degree
below the daily normal low of 43F.

Blue Hill is seeing a record April in regards to
total rainfall!

BHO Greatest April Precipitation, inches (1885-2020):

1) 10.37 in 1987
2) 9.38 in 2004
3) 8.71 in 1929
4) 8.68 in 2007
5) 8.53 in 1904
6) 8.14 in 2019
7) 7.70 in 2020 (through the 29th)
8) 7.57 in 1935
7.57 in 1983
10) 7.31 in 1901

Today’s Observations:

7 A.M.
Weather: Overcast stratus, light rain
Temperature: 42F; Dew Point: 38F; Relative Humidity: 84%
Wind: SE at 9G15 kts
Sea-level pressure: 30.31 ins. Hg: falling then rising
Visibility: 5 miles, fog
6-hr Max temp: 42F
6-hr Min temp: 38F
24-hr Precip:   Trace
24-hr Snowfall: 0.0 ins.
BHO SA 1155 E40 OVC 5R-F 265/42/38/1409G15/031/ R-CTD/
8/6// 51004 10043 20042

10 A.M.
Weather: Overcast stratus, very light rain
Temperature: 45F; Dew Point: 39F; Relative Humidity: 79%
Wind: SE at 9G18 kts
Sea-level pressure: 30.29 ins. Hg: falling steadily
Visibility: 15 miles, distant fog
3-hr Precip:  0.01 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E30 OVC 15R- 257/45/39/1409G18/029/ DSNT FG
ALQDS R-CTD PCPN VRY LGT/ 8/6// 6001/ 58006

1 P.M.
Weather: Overcast stratus
Temperature: 47F; Dew Point: 40F; Relative Humidity: 75%
Wind: SE at 10G18 kts
Sea-level pressure: 30.25 ins. Hg: falling unsteadily
Visibility: 25 miles, distant fog
6-hr Max temp: 48F
6-hr Min temp: 42F
6-hr Precip:  0.01 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E50 OVC 25 244/47/40/1410G18/025/ DSNT FG ALQDS/
8/6// 6001/ 57013 10048 20042

SUMMARY FOR WEDNESDAY, APRIL 29, 2020

TEMPERATURE (DEGREES F)
MAX…..55   NORMAL…..61
MIN…..35   NORMAL…..43
MEAN….45   NORMAL…..52

DEPARTURE FROM 30-YEAR NORMAL……………….-7
TOTAL DEPARTURE FOR THE MONTH……………….-95 [-3.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………20  DEPARTURE…….+7
TOTAL HEATING UNITS FOR THE MONTH…………..630  DEPARTURE…….+82
TOTAL HEATING UNITS FOR THE SEASON…………5503  DEPARTURE……-519
TOTAL HEATING UNITS LAST SEASON TO DATE…….5879  DEPARTURE……-376

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..24 ENE AT  11:33 A.M.
AERO…………………….23 ENE AT  11:37 A.M.
ASOS…………………….24 ENE AT  11:41 A.M.
DAVIS……………………23 ENE AT  11:40 A.M. RMY 22
FASTEST MILE FOR YESTERDAY………………….16 ENE AT  11:30 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 E   AT  11:28 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………18 E   AT  11:28 A.M.
AVERAGE WIND SPEED AND DIRECTION……………..9.7 ENE
ASOS……………………..9.9
DAVIS……………………10.3 E [97 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……….7.70  DEPARTURE……+3.28
ASOS…………..7.87
TOTAL PRECIPITATION FOR THE YEAR……….17.03  DEPARTURE……-1.13
ASOS………….17.60

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…….+1.3
TOTAL SNOWFALL FOR THE SEASON…………..31.9  DEPARTURE……-30.8

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/+3/0.00/0.0/641/80         41 W   AERO 40 W   RMY N/A
04/15  52/36/44/-3/0.02/0.0/450/56         37 W   AERO 36 W   RMY 37
04/16  47/32/40/-7/T/T/379/47              33 WNW AERO 33 WNW RMY 32
04/17  49/29/39/-8/…./0.0/591/73         41 W   AERO 39 W   RMY 41
04/18  37/31/34/-14/…./4.3/000/00        29 NE  AERO 25 NE  RMY 25
04/19  60/31/46/-2/0.00/0.0/693/85         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  53/33/43/-6/…./…/…/..         52 S   AERO 52 S   RMY 52
04/22  43/30/37/-12/0.00/0.0/…/..        51 W   AERO 50 W   RMY 50
04/23  55/29/42/-8/0.00/0.0/…/..         31 W   AERO 29 W   RMY N/A
04/24  42/37/40/-10/…./…/…/..        31 NNE AERO 29 NNE RMY 29
04/25  60/38/49/-1/0.00/0.0/…/..         25 S   AERO 24 S   RMY 24
04/26  51/38/45/-6/…./0.0/…/..         51 NE  AERO 50 NE  RMY 50
04/27  39/35/37/-14/…./T/…/..          54 NE  AERO 52 NNE RMY 55
04/28  48/35/42/-10/…./…/…/..        28 N   AERO 27 N   RMY N/A
04/29  55/35/45/-7/0.00/0.0/…/..         24 ENE AERO 23 ENE RMY 22
04/30 The low since midnight is 42F, daily normal minimum is 43F

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

4/27/2020
NEW RECORD LOW MAX TEMPERATURE OF 39F, REPLACING
THE OLD RECORD OF 40F IN 1917

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

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

RECORDS FOR MAY 1
HIGH 87F IN 1899
LOW 29F IN 1978
PRECIP 2.53 INCHES IN 1921
SNOWFALL TRACE IN 1905,1917,1921,1995,2016
PEAK GUST 57 MPH NW IN 1974

TODAY’S REPORT PREPARED BY: Benjamin Turner