Saturday, May 8, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SATURDAY, MAY 8, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0430E
SUNSET: 1850E
MOSTLY CLOUDY WITH GOOD VISIBILITY ATOP
GREAT BLUE HILL….
Today was overcast with surprisingly great visibility.
We had a mix of low and mid-level cloud cover with an
average visibility of 80 miles. Wind is northeasterly
and light with a max gust of 20 mph. This provides a
chilly breeze off the water, contributing to lower than
normal temperatures.
The high so far today is 53F, this is 11 degrees below the
normal high of 64F. The low since midnight is 40F, which
is 5 degrees below the daily normal low of 45F.
PRELIMINARY STATS FOR APRIL 2021
TEMPERATURE, Deg. F
Avg. Max. 57.2 [+1.5]Avg. Min. 37.8 [+0.1]Mean 47.5 [+0.8]24-hour corrected mean: 47.0
Max. for month: 75F on the 10th
Min. for month: 23F on the 3rd
HEATING DEGREE DAYS
Total heating units: 519 [-32]Total for the season: 5341 [-694]Total for last season: 5521
PRECIPITATION, Inches
Total: 4.89 [+0.45]Greatest in 24 hrs: N/A
SNOWFALL, Inches
Total: 3.6 [+0.6]Greatest in 24 hrs: 3.6 ins. on the 16th
WIND, mph
Avg. uncorrected wind speed: 12.1 mph
Avg. corrected wind speed: 12.5 mph
Prevailing wind direction: WNW [16%]Peak gust and direction: 58 WNW on the 30th
SUNSHINE:
Campbell-Stokes card minutes: N/A
Astronomical total minutes: N/A
Today’s Observations:
7 A.M.
Weather: Broken stratocumulus and overcast altocumulus
Temperature: 45F; Dew Point: 34F; Relative Humidity: 65%
Wind: N at 5G16 kts
Sea-level pressure: 29.85 in Hg, rising, then more steadily
Visibility: 65 miles
6-hr Max temp: 45F
6-hr Min temp: 40F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0.0 ins.
BHO SA 1155 40 BKN 70 OVC 65 107/45/34/0105G16/985/ 8/87/ 53004
10045 20040
10 A.M.
Weather: Broken stratocumulus and overcast altocumulus
Temperature: 48F; Dew Point: 37F; Relative Humidity: 65%
Wind: NE @ 8 kts
Sea-level pressure: 29.89 in Hg; rising steadily
Visibility: 75 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 40 BKN 70 OVC 75 121/48/37/0508/989/ 8/87/ 53014
1 P.M.
Weather: Broken stratocumulus and overcast altocumulus
Temperature: 52F, Dew point: 34F; Relative Humidity: 49%
Wind: NE @ 8 kts
Sea-level pressure: 29.85 in Hg; falling, then steady
Visibility: 80 miles
6-hr Max temp: 53F
6-hr Min temp: 45F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 40 BKN 90 OVC 80 109/52/34/0408/985/ 8/87/ 57012
10053 20045
SUMMARY FOR FRIDAY, MAY 7, 2021
TEMPERATURE (DEGREES F)
MAX…….61 NORMAL…..64
MIN…….43 NORMAL…..45
MEAN……52 NORMAL…..55
DEPARTURE FROM 30-YEAR (1981-2010) NORMAL…….. -3
TOTAL DEPARTURE FOR THE MONTH…………………-6 [-1.1 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL THRU JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………13 DEPARTURE…….+3
TOTAL HEATING UNITS FOR THE MONTH……………85 DEPARTURE…….+3
TOTAL HEATING UNITS FOR THE SEASON…………5426 DEPARTURE…..-691
TOTAL HEATING UNITS LAST SEASON TO DATE…….5590 DEPARTURE…..-164
COOLING DEGREE DAYS (SEASON JAN THRU DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………… 0 DEPARTURE……. 0
TOTAL COOLING UNITS FOR THE MONTH…………… 0 DEPARTURE…….-2
TOTAL COOLING UNITS FOR THE SEASON………….. 0 DEPARTURE…….-4
TOTAL COOLING UNITS LAST SEASON TO DATE……… 2 DEPARTURE…….-2
PEAK WIND GUST (MPH):
420C/Official…………..28 ESE @ 11:18 A.M.
AEROVANE (south tower)…..22 ESE @ 11:22 A.M.
ASOS…………………..25 ESE @ 11:21 A.M.
DAVIS #1……………….26 ESE @ 11:21 A.M.
DAVIS #2 (south tower)…..25 E @ 11:05 A.M.
RMY……………………26 @ 11:19 A.M.
VECTOR…………………27 @ 11:20 A.M.
MERLIN…………………24
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………17 ESE @ 11:28 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 E @ 11:42 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 ESE @ 11:22 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………18 E @ 10:50 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..18 SE @ 11:39 A.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..19 @ 11:20 A.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…… 10.1 ESE [243 total miles] ASOS………………… 10.2
DAVIS #1…………….. 10.7 E
DAVIS #2…………….. 10.4 E
RMY…………………. 10.1 ESE
VECTOR………………. 10.5
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………….1.39 DEPARTURE….+0.52
ASOS………….1.35
TOTAL PRECIPITATION FOR THE YEAR………….16.45 DEPARTURE….-2.97
ASOS………..16.63
PRELIMINARY CLIMATE SUMMARY FOR MAY 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
05/01 62/38/50/-3/0.06/0.0/…/.. 31 WNW AERO 35 WNW RMY 40
05/02 76/48/62/+9/0.01/0.0/…/.. 41 SW AERO 41 SW RMY 46
05/03 67/48/58/+5/0.07/0.0/…/.. 21 E AERO 20 E RMY 20
05/04 50/44/47/-7/…./0.0/…/.. 36 NNE AERO 32 NNE RMY 37
05/05 48/44/46/-8/…./0.0/…/.. 18 ESE AERO 14 ESE RMY 17
05/06 64/45/55/+1/0.00/0.0/…/.. 33 NW AERO 38 NNW RMY 39
05/07 61/43/52/-3/0.00/0.0/…/.. 28 ESE AERO 22 ESE RMY 26
05/08 The low since midnight is 40F, the daily normal low is 45F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR MAY 8
HIGH 89F IN 2000
LOW 29F IN 1956
PRECIP 1.48 INCHES IN 1886
SNOWFALL TRACE IN 1898, 1947
PEAK GUST 68e MPH NNW IN 1943
RECORDS FOR MAY 9
HIGH 93F IN 2000
LOW 31F IN 1947
PRECIP 2.72 INCHES IN 1954
SNOWFALL 5.0 INS IN 1977 (RECORD FOR MAY)
PEAK GUST 70e MPH NE IN 1977
TODAY’S REPORT PREPARED BY: Benjamin Turner
