Tuesday, April 28, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, APRIL 28, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

SOME IMPROVEMENT TODAY; MILDER AND DRY WITH MUCH LESS WIND….

The storm system that brought rain, gusty winds, and even some
snow mixed in has finally moved away from the region. Better
weather is being observed today. While it’s been a mostly
cloudy day, temperatures being about 10 degrees warmer than
yesterday is a welcomed improvement in itself.

Total rainfall from the storm system amounted to 1.36″. This
brings the monthly total to 7.70″, this is 3.55″ inches above
normal to date. Despite how wet April has been, we’re still
running a deficit for the year of 1.12″. A trace of snow was
also measured yesterday as snow was observed mixed with the
rain from mid afternoon into the evening hours.

We set a new record low max for the day yesterday. The high was
only 39F. The previous record was 40F set in 1917. The high of
39F on Monday was the coldest maximum temperature this late
in the season since 39F was observed on April 28, 1987.

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

We may add 1 more day before the month is over, on Thursday.
Stay tuned!

The high so far today is 48F, this is 13 degrees below our daily
normal high temperature of 61F. The low since midnight is 35F,
which is 7 degrees below the daily normal low of 42F.

Today’s Observations:

7 A.M.
Weather: Scattered stratocumulus, overcast stratus, breaks in
overcast distant S-W
Temperature: 37F; Dew Point: 31F; Relative Humidity: 78%
Wind: N at 13G20 kts
Sea-level pressure: 30.06 ins. Hg: rising, then more rapidly
Visibility: 60 miles
6-hr Max temp: 37F
6-hr Min temp: 35F
24-hr Precip:  0.58 ins.
24-hr Snowfall: TRACE
BHO SA 1155 25 SCT E35 OVC 60 180/37/31/3513G20/006/ BINOVC DSNT S-W
HIR CLDS VSBL DSNT S-W/ 8/5// 53014 70058 10037 20035

10 A.M.
Weather: Broken stratocumulus, overcast dense cirrus, thin spots
in overcast all quadrants, sun dimly visible
Temperature: 42F; Dew Point: 29F; Relative Humidity: 59%
Wind: N at 10G17 kts
Sea-level pressure: 30.07 ins. Hg: falling, then rising
Visibility: 60 miles
3-hr Precip:   0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E40 BKN 180 OVC 60 184/42/29/3610G17/007/ THN SPTS INOVC
ALQDS SUN DMLY VSBL/ 8/502 53004

1 P.M.
Weather: Broken cumulus/stratocumulus, overcast stratocumulus, few
breaks in overcast all quadrants
Temperature: 47F; Dew Point: 34F; Relative Humidity: 60%
Wind: NNE at 5 kts, wind light and variable
Sea-level pressure: 30.08 ins. Hg: rising, then falling
Visibility: 70 miles
6-hr Max temp: 48F
6-hr Min temp: 37F
6-hr Precip:  0.00 ins
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E35 BKN 75 OVC 70 185/47/34/0305/008/ FEW BINOVC ALQDS
WND L/V/ 8/8// 50001 10048 20037

SUMMARY FOR MONDAY, APRIL 27, 2020

TEMPERATURE (DEGREES F)
MAX…..39   NORMAL…..60
MIN…..35   NORMAL…..42
MEAN….37   NORMAL…..51

DEPARTURE FROM 30-YEAR NORMAL……………….-14
TOTAL DEPARTURE FOR THE MONTH……………….-78 [-3.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………28  DEPARTURE…….+14
TOTAL HEATING UNITS FOR THE MONTH…………..587  DEPARTURE…….+76
TOTAL HEATING UNITS FOR THE SEASON…………5460  DEPARTURE……-535
TOTAL HEATING UNITS LAST SEASON TO DATE…….5841  DEPARTURE……-381

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..54 NE  AT   8:02 A.M.
AERO…………………….52 NNE AT   7:55 A.M
ASOS…………………….51 NNE AT   9:01 A.M.
DAVIS……………………51 NE  AT   7:57 A.M. RMY 55
FASTEST MILE FOR YESTERDAY………………….36 NE  AT   9:02 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….33 NE  AT   9:03 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………36 NE  AT   9:03 A.M.
AVERAGE WIND SPEED AND DIRECTION…………….20.7 NNE
ASOS…………………….19.5
DAVIS……………………20.0 NE [036 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.58  DEPARTURE……+0.44
ASOS…………..0.56
TOTAL PRECIPITATION FOR THE MONTH……….7.70  DEPARTURE……+3.55
ASOS…………..7.87
TOTAL PRECIPITATION FOR THE YEAR……….17.03  DEPARTURE……-1.12
ASOS………….17.60

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……..TRACE  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 The low since midnight is 35F, daily normal minimum is 42F

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 28
HIGH 92 IN 1990, 2009
LOW 26 IN 1947
PRECIP 2.41 IN 1904
SNOWFALL 10.0 IN. IN 1987
PEAK GUST 69 MPH NE 1967

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

TODAY’S REPORT PREPARED BY: Matt Douglas