Tuesday, September 21, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
TUESDAY, SEPTEMBER 21, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0531E
SUNSET: 1743E
QUIET AND WARM UNDER A MIX OF SUN AND CLOUDS…
A mix of sun and clouds have been the theme with warming
temperatures today after a chilly start for many. Lows in many
surrounding areas were in the 40s, however up here on the hill,
our low was in the mid 50s thanks to a light SE wind blowing
all night.
The wind has been quite light again today only averaging around
6-10mph out of mainly a southerly direction. The peak gust for the
day has been 18mph.
Humidity levels are creeping up as the dew point did touch 60F
for a time. We expect higher dew points to settle in overnight and
stick around for a few days, so the pleasant air is coming to an
end.
Visibility was markedly lower today compared to the last couple.
We’ve only been able to see 30-40 miles.
The high so far today is 74F, this is 3 degrees above the daily
normal maximum of 71F. The low so far today is 55F, which is 1
degree above the daily normal minimum of 54F.
Today marks the 83rd anniversary of the Great New England Hurricane
of 1938. This system slammed into Long Island, NY. on the afternoon
of September 21st, then continuing north-northwestward through
Connecticut. Here at the Blue Hill Observatory we measured a 5
minute average sustained wind speed of 121mph out of the south, with
a calculated peak gust of 186mph! This is the highest wind gust on
our 136 year record!
With the hurricane passing to the west of the Observatory, we did
not receive much rainfall from it, with only around 3 tenths of
an inch being measured.
Today’s Observations:
7 A.M.
Weather: Scattered stratocumulus, thin scattered cirrus, patchy ground
fog all quadrants
Temperature: 59F; Dew Point: 56F; Relative Humidity: 89%
Wind: SE @ 5 kts, wind light
Sea-level pressure: 1030.1 mb; 30.42 in. Hg; steady, then rising
Visibility: 30 miles
6-hr Max temp: 59F
6-hr Min temp: 55F
24-hr Precip: 0.00 ins.
BHO SA 1155 20 SCT 250 -SCT 30 301/59/56/1305/042/ PTCHY GF ALQDS WND LGT/
8/501 53003 10059 20055
10 A.M.
Weather: Scattered stratocumulus, broken stratocumulus, thin broken cirrus
Temperature: 67F; Dew Point: 60F; Relative Humidity: 75%
Wind: SE @ 5 kts, wind light
Sea-level pressure: 1030.3 mb; 30.42 in Hg; rising, then falling
Visibility: 40 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 20 SCT E30 BKN 250 -BKN 40 303/67/60/1405/042/ WND LGT/
8/501 50002
1 P.M.
Weather: Broken cumulus
Temperature: 73F, Dew point: 58; Relative Humidity: 59%
Wind: SSE @ 5 kts, wind light
Sea-level pressure: 1028.9 mb; 30.38 in Hg; falling, then more rapidly
Visibility: 40 miles
6-hr Max temp: 74F
6-hr Min temp: 59F
6-hr Precip: 0.00 ins.
BHO SA 1755 E35 BKN 40 289/73/58/1505/038/ WND LGT/ 8/200 58014 10074 20059
SUMMARY FOR MONDAY, SEPTEMBER 20, 2021
TEMPERATURE (DEGREES F)
MAX…….71 NORMAL…..71
MIN…….55 NORMAL…..54
MEAN……63 NORMAL…..63
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………. 0
TOTAL DEPARTURE FOR THE MONTH…………………….+8 [+0.2 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY…………….2 DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE MONTH……………15 DEPARTURE…….-28
TOTAL HEATING UNITS FOR THE SEASON…………..43 DEPARTURE…….-18
TOTAL HEATING UNITS LAST SEASON TO DATE………68 DEPARTURE…….-25
COOLING DEGREE DAYS (SEASON: JAN 2021 THRU DEC 2021)
TOTAL COOLING UNITS FOR YESTERDAY…………….0 DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE MONTH……………44 DEPARTURE…….-19
TOTAL COOLING UNITS FOR THE SEASON………….694 DEPARTURE…….+35
TOTAL COOLING UNITS LAST SEASON TO DATE……..807 DEPARTURE……-113
PEAK WIND GUST (MPH):
Official……………….20 SE @ 9:38 P.M.
AEROVANE (south tower)…..20 SE @ 10:32 P.M.
VECTOR #2 (south tower)….20 @ 9:38 P.M.
DAVIS #2 (south tower)…..19 SSE @ 10:31 P.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………………17 SE @ 9:26 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..15 @ 10:30 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 SE @ 10:31 P.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……. 6.5 ESE [157 total miles]
VECTOR #2…………….. 7.5
DAVIS #2……………… 7.3 SE
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…….0.00 DEPARTURE….-0.15
TOTAL PRECIPITATION FOR THE MONTH………….5.52 DEPARTURE….+2.96
TOTAL PRECIPITATION FOR THE YEAR………….45.86 DEPARTURE….+8.95
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/…/.. 24 WNW AERO 25 WNW RMY N/A
09/07 78/57/68/+1/0.00/…/.. 23 WSW AERO 22 WSW RMY N/A
09/08 81/61/71/+4/0.00/…/.. 43 S AERO 45 S RMY N/A
09/09 71/64/68/+1/0.90/…/.. 33 S AERO 36 S RMY N/A
09/10 74/55/65/-1/0.04/…/.. 31 NW AERO 32 WNW RMY N/A
09/11 75/51/63/-3/0.00/…/.. 24 SW AERO 24 SW RMY N/A
09/12 79/60/70/+4/0.00/…/.. 33 SW AERO 32 SW RMY N/A
09/13 77/62/70/+5/0.06/…/.. 22 NW AERO 23 NW RMY N/A
09/14 75/59/67/+2/0.00/…/.. 23 S AERO 25 S RMY N/A
09/15 82/65/74/+9/T/…/.. 32 SSW AERO 35 SSW RMY N/A
09/16 69/61/65/+1/0.27/…/.. 24 ENE AERO 24 ENE RMY N/A TSTM
09/17 66/60/63/-1/0.02/…/.. 22 NE AERO 23 NE RMY N/A
09/18 74/62/68/+5/0.04/…/.. 17 WNW AERO 18 WNW RMY N/A TSTM
09/19 71/57/64/+1/0.15/…/.. 23 NNE AERO 24 NNE RMY N/A
09/20 71/55/63/0/0.00/…/.. 20 SE AERO 20 SE RMY N/A
09/21 The low since midnight is 55F, the daily normal low is 54F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR SEPTEMBER 21
HIGH 91 IN 1895
LOW 35 IN 1929, 1956, 1962
PRECIP 5.58 INS IN 1961 (HURRICANE ESTHER; RETURNED AS TS SEPT 25-26TH)
PEAK GUST 186 MPH S IN 1938 (GREAT NEW ENGLAND HURRICANE; CALCULATED GUST, STATION RECORD)
RECORDS FOR SEPTEMBER 22
HIGH 90F IN 1895, 1914
LOW 30F IN 1904 (Earliest freeze)
PRECIP 1.16 INCHES IN 2001
PEAK GUST 60 MPH SSW IN 1989
TODAY’S REPORT PREPARED BY: Matt Douglas
