Wednesday, April 29, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, APRIL 29, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

A NICE DAY WITH RELATIVELY LIGHTER WIND AND
PARTLY CLOUDY SKIES….

Today the observatory saw fair weather, with partly cloudy
skies and a good visibility around 70 miles. Wind shifted
from north to east since this morning, with an average
speed of 10 mph. Today was, again, dry in contrast to
a few days ago, but the monthly rain total is something
to take note of. Our rain amount for April 2020 is 7.70
inches, which is 3.41 inches above the normal. This may
be nature’s way of making up for some drier months
earlier this year.

An interesting stat, considering how unusually light winds were
during winter, April is trying to make up for it. We have
measured wind gusts of 50 mph or higher the last 4 consecutive
weeks. Here is the listing of days with peak gusts exceeding
50 mph.

4/9:  58 mph
4/13: 79 mph
4/21: 52 mph
4/22: 51 mph
4/26: 51 mph
4/27: 54 mph

Wind Stats Section written by:

Matthew Douglas

The high so far today is 54F, this is 7 degrees below our daily
normal high temperature of 61F. The low since midnight is 35F,
which is 8 degrees below the daily normal low of 43F.

Today’s Observations:

7 A.M.
Weather: Clear, few translucent cirrostratus
Temperature: 42F; Dew Point: 35F; Relative Humidity: 76%
Wind: N at 8 kts
Sea-level pressure: 30.27 ins. Hg: rising steadily
Visibility: 70 miles
6-hr Max temp: 40F
6-hr Min temp: 35F
24-hr Precip:  0.00 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 CLR 70 252/42/35/3508/027/ FEW CS ALQDS/ 8/008
53021 10040 20035

10 A.M.
Weather: Broken cirrostratus
Temperature: 52F; Dew Point: 34F; Relative Humidity: 49%
Wind: E at 7 kts
Sea-level pressure: 30.32 ins. Hg: falling, then rising
Visibility: 70 miles
3-hr Precip:   0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E250 BKN 70 268/52/34/0807/032/ 8/007 51016

1 P.M.
Weather: Scattered cirrus
Temperature: 54F; Dew Point: 30F; Relative Humidity: 39%
Wind: E at 8 kts
Sea-level pressure: 30.34 ins. Hg: rising steadily
Visibility: 70 miles
6-hr Max temp: 54F
6-hr Min temp: 42F
6-hr Precip:  0.00 ins
6-hr Snowfall: 0.0 ins.
BHO SA 1755 250 SCT 70 274/54/30/0808/034/ 8/002 53006 10054 20042

SUMMARY FOR TUESDAY, APRIL 28, 2020

TEMPERATURE (DEGREES F)
MAX…..48   NORMAL…..61
MIN…..35   NORMAL…..42
MEAN….42   NORMAL…..52

DEPARTURE FROM 30-YEAR NORMAL……………….-10
TOTAL DEPARTURE FOR THE MONTH……………….-88 [-3.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………23  DEPARTURE…….+10
TOTAL HEATING UNITS FOR THE MONTH…………..610  DEPARTURE…….+85
TOTAL HEATING UNITS FOR THE SEASON…………5483  DEPARTURE……-526
TOTAL HEATING UNITS LAST SEASON TO DATE…….5861  DEPARTURE……-378

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..28 N   AT  12:23 A.M.
AERO…………………….MISSING
ASOS…………………….28 N   AT  12:24 A.M.
DAVIS……………………29 N   AT  12:23 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………….18 N   AT   7:59 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 N   AT   7:58 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………19 N   AT  12:25 A.M.
AVERAGE WIND SPEED AND DIRECTION……………..9.3 N
ASOS……………………..9.3
DAVIS…………………….9.7 NNE [22 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….7.70  DEPARTURE……+3.41
ASOS…………..7.87
TOTAL PRECIPITATION FOR THE YEAR……….17.03  DEPARTURE……-1.26
ASOS………….17.60

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…….+1.3
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 The low since midnight is 35F, 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 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