Thursday, September 30, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
THURSDAY, SEPTEMBER 30, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0540E
SUNSET: 1730E
CLOUDY AND COOL ATOP GREAT BLUE HILL….
Today consisted of cool, fall-like weather with an average visibility
of 80 miles. Wind was northwesterly with an average speed of 10 mph.
The highest gust so far today is 18 mph. Cloud cover increased around
noontime, covering up almost all of the sky.
Today was dry with dew points in the mid 40’s. This makes for
another nice fall day.
The high so far today is 60F, 7 degrees below the normal max of 67F.
The low since midnight is 48F, 2 degrees below the normal low of 50F.
Today’s Observations:
7 A.M.
Weather: Scattered stratocumulus, broken altocumulus
Temperature: 50F; Dew Point: 47F; Relative Humidity: 89%
Wind: NNW @ 10 kts
Sea-level pressure: 1017.4 mb; 30.04 in. Hg; rising, then more
rapidly
Visibility: 70 miles
6-hr Max temp: 51F
6-hr Min temp: 48F
24-hr Precip: 0.01 ins.
BHO SA 1155 50 SCT 120 BKN 70 174/50/47/3410/004/ 8/550 70001
53009 10051 20048
10 A.M.
Weather: Scattered Cumulus
Temperature: 57F; Dew Point: 45F; Relative Humidity: 64%
Wind: WNW @ 10G15 kts
Sea-level pressure: 1017.1 mb; 30.03 in Hg; rising then falling
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 40 SCT 80 171/57/45/3010G15/003/ 8/200 55003
1 P.M.
Weather: Broken stratocumulus
Temperature: 57F, Dew point: 43F; Relative Humidity: 59%
Wind: N @ 9G16 kts
Sea-level pressure: 1017.2 mb; 30.03 in Hg; rising then falling
Visibility: 80 miles
6-hr Max temp: 60F
6-hr Min temp: 49F
6-hr Precip: 0.00 ins.
BHO SA 1755 60 BKN 80 172/57/43/3409G16/003/ 8/800 50001 10060 20049
SUMMARY FOR WEDNESDAY, SEPTEMBER 29, 2021
TEMPERATURE (DEGREES F)
MAX…….63 NORMAL…..67
MIN…….45 NORMAL…..50
MEAN……54 NORMAL…..59
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………. -5
TOTAL DEPARTURE FOR THE MONTH…………………….+46 [+1.4 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY……………11 DEPARTURE……..+4
TOTAL HEATING UNITS FOR THE MONTH……………34 DEPARTURE…….-59
TOTAL HEATING UNITS FOR THE SEASON…………..62 DEPARTURE…….-49
TOTAL HEATING UNITS LAST SEASON TO DATE………97 DEPARTURE…….-35
COOLING DEGREE DAYS (SEASON: JAN 2021 THRU DEC 2021)
TOTAL COOLING UNITS FOR YESTERDAY…………….0 DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH……………62 DEPARTURE…….-12
TOTAL COOLING UNITS FOR THE SEASON………….712 DEPARTURE…….+43
TOTAL COOLING UNITS LAST SEASON TO DATE……..826 DEPARTURE……-118
PEAK WIND GUST (MPH):
Official……………….25 NNW @ 12:23 A.M.
AEROVANE (south tower)…..25 NNW @ 12:23 A.M.
VECTOR #2 (south tower)….26 @ 12:23 A.M.
DAVIS #2 (south tower)…..22 NNW @ 12:23 A.M.
ASOS………..OUT OF SERVICE D/T RENOVATIONS
VECTOR #1……OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…….OUT OF SERVICE D/T RENOVATIONS
RMY…………OUT OF SERVICE D/T RENOVATIONS
MERLIN………OUT OF SERVICE D/T RENOVATIONS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………15 NNW @ 1:05 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..15 @ 12:59 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………15 N @ 1:00 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE…….OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE..OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE RMY AVERAGE……..OUT OF SERVICE D/T RENOVATIONS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..8.0 NNW [191 total miles]
VECTOR #2………………8.7
DAVIS #2……………….8.3 N
RMY……………..OUT OF SERVICE D/T RENOVATIONS
ASOS…………….OUT OF SERVICE D/T RENOVATIONS
VECTOR #1………..OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…………OUT OF SERVICE D/T RENOVATIONS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.01 DEPARTURE….-0.14
TOTAL PRECIPITATION FOR THE MONTH………….6.64 DEPARTURE….+2.74
TOTAL PRECIPITATION FOR THE YEAR………….46.98 DEPARTURE….+8.73
PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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
09/01 68/56/62/-7/1.47/000/00 34 NNE AERO 37 NNE RMY N/A
09/02 71/55/63/-6/2.53/322/41 49 ENE AERO 52 ENE RMY N/A
09/03 72/52/62/-6/0.00/735/94 23 NW AERO 23 NW RMY N/A
09/04 76/55/66/-2/0.00/757/97 22 WNW AERO 21 WNW RMY N/A
09/05 72/60/66/-2/0.04/008/01 27 S AERO 29 S RMY N/A
09/06 80/61/71/+3/0.00/557/72 24 WNW AERO 25 WNW RMY N/A
09/07 78/57/68/+1/0.00/732/95 23 WSW AERO 22 WSW RMY N/A
09/08 81/61/71/+4/0.00/646/84 43 S AERO 45 S RMY N/A
09/09 71/64/68/+1/0.90/000/00 33 S AERO 36 S RMY N/A
09/10 74/55/65/-1/0.04/595/78 31 NW AERO 32 WNW RMY N/A
09/11 75/51/63/-3/0.00/730/96 24 SW AERO 24 SW RMY N/A
09/12 79/60/70/+4/0.00/591/78 33 SW AERO 32 SW RMY N/A
09/13 77/62/70/+5/0.06/559/74 22 NW AERO 23 NW RMY N/A
09/14 75/59/67/+2/0.00/444/59 23 S AERO 25 S RMY N/A
09/15 82/65/74/+9/T/539/72 32 SSW AERO 35 SSW RMY N/A
09/16 69/61/65/+1/0.27/037/05 24 ENE AERO 24 ENE RMY N/A TSTM
09/17 66/60/63/-1/0.02/000/00 22 NE AERO 23 NE RMY N/A
09/18 74/62/68/+5/0.04/207/28 17 WNW AERO 18 WNW RMY N/A TSTM
09/19 71/57/64/+1/0.15/619/84 23 NNE AERO 24 NNE RMY N/A
09/20 71/55/63/0/0.00/588/80 20 SE AERO 20 SE RMY N/A
09/21 75/55/65/+3/0.00/…/.. 19 SSE AERO 20 SSE RMY N/A
09/22 75/65/70/+8/0.02/…/.. 30 S AERO 30 S RMY N/A
09/23 78/65/72/+10/0.08/…/.. 36 SSE AERO 37 SSE RMY N/A
09/24 75/62/69/+8/0.02/…/.. 43 SSE AERO 45 SSE RMY N/A
09/25 74/59/67/+6/0.02/…/.. 14 N AERO 14 NNW RMY N/A
09/26 73/54/64/+4/0.57/…/.. 33 WNW AERO 32 WNW RMY N/A
09/27 73/52/63/+3/T/…/.. 30 SW AERO 30 SW RMY N/A
09/28 67/52/60/+1/0.40/…/.. 27 SSW AERO 25 SSW RMY N/A TSTM
09/29 63/45/54/-5/…./…/.. 25 NNW AERO 25 NNW RMY N/A
09/30 The low since midnight is 48F, the daily normal low is 50F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR SEPTEMBER 30
HIGH 84F IN 1986
LOW 31F IN 1992
PRECIP 2.44 INCHES IN 2015
PEAK GUST 71 MPH S IN 2020
RECORDS FOR OCTOBER 1
HIGH 85F IN 1927
LOW 30F IN 1992
PRECIP 1.63 INCHES IN 2014
PEAK GUST 68e MPH SSE IN 1977
TODAY’S REPORT PREPARED BY: Benjamin Turner
