Tuesday, April 30, 2019

| April 30, 2019 | Reply

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, APRIL 30, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

OVERCAST WITH SOME RAIN IN THE MORNING AND
LIGHT WINDS THROUGHOUT THE DAY….

We measured 0.17 inches of precipitation from
rainfall earlier this morning. Visibility improved
from a mile at 7 A.M. to 20 miles this afternoon.
We observed the sun breaking out of the clouds at
the 1 P.M. observation. Wind has been relatively
calm, with an average speed of 3 mph. The high so
far today is 45F, 16 degrees below the daily normal
maximum of 61F. The low since midnight is 40F, three
degrees below the daily normal of 43F.

BHO Greatest April Precipitation, inches (1885-2019):

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  (through 7 AM on 4/30)
7)  7.57 in 1935
7.57 in 1983
9)  7.31 in 1901

The calendar day rainfall on Monday, 4/22, was more than
two and a half inches, which made it one of the wettest
calendar days ever observed in April. The finalized
amount for the day will be reported when available.

BHO Greatest April Calendar Day Precipitation, inches (1885-2019):

1) 3.47 on April 1,  2004
2) 3.18 on April 21, 1991
3) 2.63 on April 16, 2018
4) 2.51 on April 24, 1898
2.51 on April 13, 2004
6) 2.45 on April 16, 1929
7) 2.41 on April 28, 1904
8) 2.40 on April 10, 1935

Today’s Observations:

7 A.M.
Weather: Light drizzle, partial obscuration due to fog
Temperature: 40F; Dew Point: 40F; Wind: SSE at 4 kts,
Wind: Light
Sea-level pressure: 30.20 ins. Hg, falling steadily
Visibility: 1 mile, fog
6-hr Max temp: 44F
6-hr Min temp: 40F
24-hr Precip: 0.17 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 –X 1L-F 228/40/40/1604/020/ L-CTD WND LGT/
8//// 70017 58005 10044 20040

10 A.M.
Weather: Overcast altostratus, few stratus fractus
Temperature: 43F; Dew Point: 43F; Wind: W at 1 kt,
Wind: Light and variable
Sea-level pressure: 30.21 ins. Hg, rising steadily
Visibility: 20 miles, except 8 miles W-NE
3-hr Precip: Trace
BHO SA 1455 E65 OVC 20 230/43/43/E2601/021/ DSNT FG FEW
STFA ALQDS VSBY 8 W-NE WND L/V/ 8/72/ 53002

1 P.M.
Weather: Overcast stratus
Temperature: 45F; Dew Point: 43F; Wind: NW at 5 kts,
Wind: Light
Sea-level pressure: 30.24 ins. Hg, rising steadily
Visibility: 20 miles, distant fog
6-hr Max temp: 45F
6-hr Min temp: 40F
6-hr Precip: Trace
6-hr snowfall: 0.0 ins.
BHO SA 1755 E15 OVC 20 238/45/43/3205/024/ DSNT FG ALQDS
WND LGT/ 8/6// 600// 53008 10045 20040

SUMMARY FOR MONDAY, APRIL 29, 2019

TEMPERATURE (DEGREES F)
MAX…..60   NORMAL…..61
MIN…..34   NORMAL…..43
MEAN….47   NORMAL…..52

DEPARTURE FROM 30-YEAR NORMAL……………………-5
TOTAL DEPARTURE FOR THE MONTH…………………..+61 [+1.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..18   DEPARTURE………+5
TOTAL HEATING UNITS FOR THE MONTH………….475   DEPARTURE……..-63
TOTAL HEATING UNITS FOR THE SEASON………..5880   DEPARTURE…….-142
TOTAL HEATING UNITS LAST SEASON TO DATE……5669   DIFFERENCE……+211

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..23 NW  AT  8:58 A.M.
AERO…………………….24 WNW AT 10:38 A.M.
ASOS…………………….25 NW  AT  9:00 A.M.
DAVIS……………………25 W   AT  8:58 A.M.  RMY 24
FASTEST MILE FOR YESTERDAY………………….19 W   AT  2:32 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 WNW AT  2:28 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………19 WSW AT  2:30 P.M.
AVERAGE WIND SPEED AND DIRECTION……………9.9 W
ASOS…………………..10.2
DAVIS………………….10.2 WSW [249 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.17  DEPARTURE…….+0.04
ASOS…………..0.16
TOTAL PRECIPITATION FOR THE MONTH……….8.14  DEPARTURE…….+3.72
ASOS…………..8.06
TOTAL PRECIPITATION FOR THE YEAR……….21.18  DEPARTURE…….+2.76
ASOS………….21.21

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M………0.0  DEPARTURE……..-0.1
TOTAL SNOWFALL FOR THE MONTH………….TRACE  DEPARTURE……..-3.0
TOTAL SNOWFALL FOR THE SEASON………….47.6  DEPARTURE…….-15.1

PRELIMINARY CLIMATE SUMMARY FOR MARCH 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 45/29/37/-4/0.00/0.0/748/98           40 WNW AERO 37 W   RMY 42
04/02 50/27/39/-2/…./0.0/605/79           29 S   AERO 25 S   RMY 31
04/03 62/35/49/+7/…./0.0/484/63           54 W   AERO 58 W   RMY 56
04/04 50/34/42/0/…./0.0/717/93            46 W   AERO 41 W   RMY N/A
04/05 47/27/37/-6/…./0.0/341/44           23 SSW AERO 17 SSW RMY 23
04/06 64/32/48/+5/…./0.0/536/69           24 NW  AERO 18 W   RMY 26
04/07 66/41/54/+11/0.00/0.0/320/41          24 S   AERO 18 S   RMY 25
04/08 48/34/41/-3/0.49/0.0/000/00           25 NE  AERO 20 NE  RMY 26
04/09 40/32/36/-8/0.08/0.0/000/00           23 NE  AERO 16 N   RMY 25
04/10 43/30/37/-8/T/T/000/00                32 NW  AERO 26 NW  RMY 36
04/11 51/29/40/-5/0.00/0.0/403/51           23 NW  AERO 18 NW  RMY N/A
04/12 53/38/46/+1/…./0.0/000/00           35 SSW AERO 29 SSW RMY 39
04/13 71/54/63/+17/…./0.0/167/21          38 SSW AERO 32 SSW RMY N/A
04/14 71/51/61/+15/…./0.0/224/28          25 S   AERO 18 S   RMY N/A
04/15 67/40/54/+7/…./0.0/168/21           46 W   AERO 52 W   RMY 50
04/16 58/37/48/+1/0.00/0.0/805/100          46 W   AERO 44 W   RMY 44
04/17 62/36/49/+2/0.00/0.0/807/100          26 ESE AERO 25 S   RMY 28
04/18 63/39/51/+3/0.00/0.0/000/00           44 S   AERO 44 S   RMY 50
04/19 71/58/65/+17/…./0.0/049/06          47 SSW AERO 51 SSW RMY 52
04/20 68/60/64/+15/…./0.0/000/00          50 SSW AERO 54 SSW RMY 52
04/21 68/51/60/+11/…./0.0/123/15          35 S   AERO 35 S   RMY N/A
04/22 53/45/49/0/…./0.0/000/00            35 NNE AERO 32 NNE RMY 35
04/23 52/44/48/-2/…./0.0/041/05           30 NNE AERO 26 NNE RMY N/A
04/24 65/44/55/+5/…./0.0/…/..           29 WNW AERO 29 WNW RMY 30
04/25 61/39/50/0/0.00/0.0/…/..            22 S   AERO 22 S   RMY 21
04/26 53/42/48/-3/…./0.0/…/..           35 ESE AERO 30 W   RMY 33
04/27 54/39/47/-4/…./…/…/..           41 W   AERO 44 W   RMY 47
04/28 51/38/45/-7/0.08/0.0/…/..           28 W   AERO 28 W   RMY N/A
04/29 60/34/47/-5/0.00/0.0/…/..           23 NW  AERO 24 WNW RMY 24

04/30 Low temp since midnight is 40F; normal low is 43F

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

Category: Daily Discussions

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