Saturday, April 25, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, APRIL 25, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

MILD WITH PARTIAL CLOUDS AND GOOD VISIBILITY
ATOP GREAT BLUE HILL…

We observed partly cloudy skies today, mostly consisting
of altocumulus. Visibility was 20 miles this morning due
to a layer of haze, but increased to 70 miles as the day
went on. Wind was light and variable, but mostly blowing
in from the northeast. However, the max gust of 19 mph
happened between 10 A.M. and 1 P.M.

Our high temperature so far today is 60F, which is a
degree below our daily normal high temperature of 59F.
The low since midnight is 38F, which is 4 degrees below
the daily normal low of 41F.

Today’s Observations:

7 A.M.
Weather: Broken altocumulus
Temperature: 45F; Dew Point: 32F; Relative Humidity: 60%
Wind: NW at 7 kts
Sea-level pressure: 30.01 ins. Hg: rising unsteadily
Visibility: 20 miles, hazy
6-hr Max temp: 45F
6-hr Min temp: 38F
24-hr Precip:  0.19 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 E70 BKN 20 164/45/32/3207/001/ HAZY/ 8/070 52023
10045 20038

10 A.M.
Weather: Broken altocumulus
Temperature: 55F; Dew Point: 30F; Relative Humidity: 37%
Wind: WNW at 4 kts, light and variable
Sea-level pressure: 30.06 ins. Hg: rising steadily
Visibility: 70 miles
3-hr Precip:   0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E70 BKN 70 179/55/30/3004/006/ WND L/V/ 8/070 53015

1 P.M.
Weather: Broken altocumulus
Temperature: 60F; Dew Point: 34F; Relative Humidity: 38%
Wind: NNE at 4 kts, light and variable
Sea-level pressure: 30.08 ins. Hg: rising steadily
Visibility: 70 miles
6-hr Max temp: 60F
6-hr Min temp: 45F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E70 BKN 70 185/60/34/0204/008/ WND L/V/ 8/070 53006
10060 20045

SUMMARY FOR FRIDAY, APRIL 24, 2020

TEMPERATURE (DEGREES F)
MAX…..42   NORMAL…..59
MIN…..37   NORMAL…..41
MEAN….40   NORMAL…..50

DEPARTURE FROM 30-YEAR NORMAL……………….-10
TOTAL DEPARTURE FOR THE MONTH……………….-57 [-2.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………25  DEPARTURE……..+8
TOTAL HEATING UNITS FOR THE MONTH…………..523  DEPARTURE…….+55
TOTAL HEATING UNITS FOR THE SEASON…………5396  DEPARTURE……-556
TOTAL HEATING UNITS LAST SEASON TO DATE…….5791  DEPARTURE……-395

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..31 NNE AT  12:45 A.M.
AERO…………………….29 W   AT   1:19 A.M
ASOS…………………….30 W   AT  12:02 A.M.
DAVIS……………………29 ENE AT  11:36 A.M. RMY 29
FASTEST MILE FOR YESTERDAY………………….20 NNE AT  12:42 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….20 NNE AT   2:48 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………19 NNE AT  12:47 P.M.
AVERAGE WIND SPEED AND DIRECTION……………..9.8 NE
ASOS…………………….10.0
DAVIS……………………10.0 NNE [39 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.19  DEPARTURE……+0.06
ASOS…………..0.19
TOTAL PRECIPITATION FOR THE MONTH……….6.34  DEPARTURE……+2.59
ASOS…………..6.52
TOTAL PRECIPITATION FOR THE YEAR……….15.67  DEPARTURE……-2.08
ASOS………….16.25

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.1
TOTAL SNOWFALL FOR THE MONTH…………….4.3  DEPARTURE…….+1.4
TOTAL SNOWFALL FOR THE SEASON…………..31.9  DEPARTURE……-30.7

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  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 The low since midnight is 38F, daily normal minimum is 41F

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 25
HIGH 83 IN 2009
LOW 24 IN 1892
PRECIP 1.38 IN. IN 1901
SNOWFALL 0.7 IN. IN 2002.
PEAK GUST 66 MPH SE IN 1968

RECORDS FOR APRIL 26
HIGH 88 IN 2009
LOW 23 IN 1919
PRECIP 1.64 IN. IN 1931
SNOWFALL 1.0 IN. IN 2000
PEAK GUST 53 MPH SSW IN 1996

TODAY’S REPORT PREPARED BY: Benjamin Turner