Sunday, September 19, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SUNDAY, SEPTEMBER 19, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0529E
SUNSET: 1746E
A SPECTACULAR MID SEPTEMBER DAY HERE AT BLUE HILL…
What a spectacular day here with plenty of bright sunshine once
some early morning clouds cleared out. Humidity levels have
dropped off with the dew point leaving the humid mid 60s in the
wee hours of the morning to very pleasant levels of low 50s
early this afternoon.
With the crisp air, visibility is excellent averaging around 80
miles all day!
A east-northeast breeze is blowing in at generally light speeds
of 5-10 mph, but occasionally gusts up to near 20 mph.
All in all it’s easily a contender for a top 10 day!
The high so far today is 69F, this is 3 degrees below the
daily normal maximum of 72F. The low so far today is 58F,
which is 3 degrees above the daily normal minimum of 55F.
Today’s Observations:
7 A.M.
Weather: Broken stratocumulus, few lower stratocumulus distant S-SSW
Temperature: 59F; Dew Point: 55F; Relative Humidity: 86%
Wind: N @ 9G16 kts
Sea-level pressure: 1020.8 mb; 30.14 in. Hg; rising, then more rapidly
Visibility: 80 miles
6-hr Max temp: 66F
6-hr Min temp: 58F
24-hr Precip: 0.17 ins.
BHO SA 1155 E45 BKN 80 208/59/55/0109G16/014/ FEW LWR SC DSNT S-SSW/
8/500 53026 6015/ 70017 10066 20058
10 A.M.
Weather: Clear, few stratocumulus distant SSE-SW-N, few cirrus all
quadrants
Temperature: 66F; Dew Point: 54F; Relative Humidity: 65%
Wind: NE @ 5 kts, wind light
Sea-level pressure: 1021.9 mb; 30.18 in Hg; rising, then more slowly
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 80 219/66/54/0405/018/ FEW SC DSNT SSE-SW-N FEW CI AQLDS
WND LGT/ 8/501 51011
1 P.M.
Weather: Clear, few cumulus S-W-N, few cirrus distant SSW-W
Temperature: 69F, Dew point: 51; Relative Humidity: 52%
Wind: ENE @ 7 kts
Sea-level pressure: 1021.8 mb; 30.17 in Hg; rising, then falling
Visibility: 80 miles
6-hr Max temp: 69F
6-hr Min temp: 59F
6-hr Precip: 0.00 ins.
BHO SA 1755 CLR 80 218/69/51/0707/017/ FEW CU S-W-N FEW CI DSNT SSW-W/
8/101 58001 10069 20059
SUMMARY FOR SATURDAY, SEPTEMBER 18, 2021
TEMPERATURE (DEGREES F)
MAX…….74 NORMAL…..72
MIN…….62 NORMAL…..55
MEAN……68 NORMAL…..63
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………….+5
TOTAL DEPARTURE FOR THE MONTH…………………….+7 [+0.2 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY…………….0 DEPARTURE……..-4
TOTAL HEATING UNITS FOR THE MONTH……………12 DEPARTURE…….-23
TOTAL HEATING UNITS FOR THE SEASON…………..40 DEPARTURE…….-13
TOTAL HEATING UNITS LAST SEASON TO DATE………38 DEPARTURE……..+2
COOLING DEGREE DAYS (SEASON: JAN 2021 THRU DEC 2021)
TOTAL COOLING UNITS FOR YESTERDAY…………….3 DEPARTURE……..+1
TOTAL COOLING UNITS FOR THE MONTH……………44 DEPARTURE…….-16
TOTAL COOLING UNITS FOR THE SEASON………….694 DEPARTURE…….+39
TOTAL COOLING UNITS LAST SEASON TO DATE……..807 DEPARTURE……-113
PEAK WIND GUST (MPH):
Official……………….17 WNW @ 8:50 P.M.
AEROVANE (south tower)…..18 WNW @ 8:52 P.M.
VECTOR #2 (south tower)….18 @ 8:50 P.M.
DAVIS #2 (south tower)…..17 NW @ 8:51 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………………13 NNW @ 3:22 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..14 @ 8:52 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………14 WNW @ 8:53 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……. 5.0 N [121 total miles]
VECTOR #2…………….. 6.1
DAVIS #2……………… 5.5 NNE
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…….0.17 DEPARTURE….+0.03
TOTAL PRECIPITATION FOR THE MONTH………….5.52 DEPARTURE….+3.26
TOTAL PRECIPITATION FOR THE YEAR………….45.86 DEPARTURE….+9.25
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 The low since midnight is 58F, the daily normal low is 55F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR SEPTEMBER 19
HIGH 87F IN 1906,1983
LOW 37F IN 1929
PRECIP 3.69 INCHES IN 1936
PEAK GUST 55 MPH S IN 2012
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
TODAY’S REPORT PREPARED BY: Matt Douglas
