Monday, September 20, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
MONDAY, SEPTEMBER 20, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0530E
SUNSET: 1745E
ANOTHER BEAUTIFUL DAY BEING OBSERVED HERE AT BLUE HILL…
We are having another very beautiful day with plenty of sun
mixing with some diurnal stratocumulus/cumulus clouds.
The wind has been quite light all day, as a matter of fact it
was completely calm for about 2 hours early this morning. Since
7 A.M., we’ve been only averaging around 4-5mph out of mainly an
easterly direction. The peak gust for the day has only been a
measly 12mph!!
Humidity levels are starting to creep up as the dew point
started the day in the low 50s, but has risen to the mid-upper
50s by early this afternoon. It’s still pleasant for now.
Visibility continues to be excellent starting the day at around
80 miles, but has slipped a bit to around 70 miles by late morning.
The high so far today is 71F, this is equal to the daily normal
maximum of 71F. The low so far today is 55F, which is 1 degrees
above the daily normal minimum of 54F.
Tomorrow 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: Clear, few stratocumulus distant SSW-NW and offshore distant
E-ESE, few cirrus distant NE-E
Temperature: 58F; Dew Point: 52F; Relative Humidity: 80%
Wind: Calm
Sea-level pressure: 1028.0 mb; 30.36 in. Hg; rising, then more rapidly
Visibility: 80 miles
6-hr Max temp: 58F
6-hr Min temp: 55F
24-hr Precip: 0.00 ins.
BHO SA 1155 CLR 80 280/58/52/0000/036/ FEW SC DSNT SSW-NW AND OFFSHR
DSNT E-ESE FEW CI DSNT NE-E WND CALM/ 8/501 53020 10058 20055
10 A.M.
Weather: Clear, few stratocumulus/cumulus all quadrants, few cirrus
distant NNE-E
Temperature: 67F; Dew Point: 54F; Relative Humidity: 63%
Wind: ENE @ 5 kts, wind light
Sea-level pressure: 1029.5 mb; 30.40 in Hg; rising, then more slowly
Visibility: 70 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 70 295/67/54/0705/040/ FEW SC/CU ALQDS FEW CI DSNT NNE-E
WND LGT/ 8/801 51015
1 P.M.
Weather: Scattered stratocumulus/cumulus
Temperature: 70F, Dew point: 57; Relative Humidity: 63%
Wind: E @ 5 kts, wind light
Sea-level pressure: 1028.9 mb; 30.38 in Hg; steady, then falling
Visibility: 70 miles
6-hr Max temp: 71F
6-hr Min temp: 58F
6-hr Precip: 0.00 ins.
BHO SA 1755 40 SCT 70 289/70/57/0805/038/ WND LGT/ 8/800 58006 10071 20058
SUMMARY FOR SUNDAY, SEPTEMBER 19, 2021
TEMPERATURE (DEGREES F)
MAX…….71 NORMAL…..72
MIN…….57 NORMAL…..55
MEAN……64 NORMAL…..63
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………….+1
TOTAL DEPARTURE FOR THE MONTH…………………….+8 [+0.2 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY…………….1 DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE MONTH……………13 DEPARTURE…….-26
TOTAL HEATING UNITS FOR THE SEASON…………..41 DEPARTURE…….-16
TOTAL HEATING UNITS LAST SEASON TO DATE………52 DEPARTURE…….-11
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…….-17
TOTAL COOLING UNITS FOR THE SEASON………….694 DEPARTURE…….+37
TOTAL COOLING UNITS LAST SEASON TO DATE……..807 DEPARTURE……-113
PEAK WIND GUST (MPH):
Official……………….23 NNE @ 5:35 A.M.
AEROVANE (south tower)…..24 NNE @ 5:36 A.M.
VECTOR #2 (south tower)….24 @ 6:38 A.M.
DAVIS #2 (south tower)…..22 ENE @ 2:53 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………………14 NNE @ 6:18 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..16 @ 5:37 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………15 NNE @ 5:38 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……. 7.4 NNE [178 total miles]
VECTOR #2…………….. 8.3
DAVIS #2……………… 8.1 ENE
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….+3.11
TOTAL PRECIPITATION FOR THE YEAR………….45.86 DEPARTURE….+9.10
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 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 20
HIGH 90 IN 1983
LOW 34 IN 1979
PRECIP 4.57 INS IN 1899
PEAK GUST 44 MPH NE IN 1972
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)
TODAY’S REPORT PREPARED BY: Matt Douglas
