Saturday, September 18, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SATURDAY, SEPTEMBER 18, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0528E
SUNSET: 1748E
CLOUDS HANGING TOUGH SO FAR, BUT SKY IS STARTING TO BRIGHTEN…
We started the day in the clouds here on the summit with only 1/8th
mile visibility. Drizzle developed late yesterday afternoon and
continued through the overnight and into mid-morning this morning.
0.05″ of measurable water resulted from the drizzle, 0.04″ of which
falling prior to 7 A.M. and 0.01″ coming after.
Clouds have been hanging tough into early this afternoon, but the
cloud heights have lifted allowing for 40 miles of visibility. While
no breaks in the overcast are showing, brightening of the sky is
occurring, so it’s just a matter of time before we get at least a
little sun later this afternoon.
The high so far today is 68F, this is 4 degrees below the
daily normal maximum of 72F. The low so far today is 62F,
which is 7 degrees above the daily normal minimum of 55F.
Today’s Observations:
7 A.M.
Weather: Sky Obscured, Vertical Visibility 200 feet, light drizzle
Temperature: 63F; Dew Point: 63F; Relative Humidity: 100%
Wind: NNE @ 4 kts, wind light
Sea-level pressure: 1019.9 mb; 30.12 in. Hg; falling, then rising
Visibility: 1/8 mile, fog
6-hr Max temp: 63F
6-hr Min temp: 62F
24-hr Precip: 0.04 ins.
BHO SA 1155 X W2 1/8L-F 199/63/63/0204/012/ WND LGT/ 8//// 53003 6002/
70004 10063 20062
10 A.M.
Weather: Sky Obscured, Vertical Visibility 300 feet
Temperature: 65F; Dew Point: 65F; Relative Humidity: 100%
Wind: ENE @ 6 kts
Sea-level pressure: 1018.6 mb; 30.08 in Hg; falling, then more rapidly
Visibility: 1 mile, fog
3-hr Precip: 0.01 ins.
BHO SA 1455 X W3 1F 186/65/65/0606/008/ 8//// 58013 6001/
1 P.M.
Weather: Overcast Stratus
Temperature: 67F, Dew point: 66; Relative Humidity: 96%
Wind: WNW @ 3 kts, wind light and variable
Sea-level pressure: 1017.4 mb; 30.04 in Hg; rising, then falling
Visibility: 40 miles
6-hr Max temp: 68F
6-hr Min temp: 63F
6-hr Precip: 0.01 ins.
BHO SA 1755 E6 OVC 40 174/67/66/3003/004/ WND L/V/ 8/6// 58012 6001/ 10068 20063
SUMMARY FOR FRIDAY, SEPTEMBER 17, 2021
TEMPERATURE (DEGREES F)
MAX…….66 NORMAL…..72
MIN…….60 NORMAL…..55
MEAN……63 NORMAL…..64
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………….-1
TOTAL DEPARTURE FOR THE MONTH…………………….+2 [-0.1 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY…………….2 DEPARTURE……..-1
TOTAL HEATING UNITS FOR THE MONTH……………12 DEPARTURE…….-20
TOTAL HEATING UNITS FOR THE SEASON…………..40 DEPARTURE…….-10
TOTAL HEATING UNITS LAST SEASON TO DATE………29 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……………41 DEPARTURE…….-17
TOTAL COOLING UNITS FOR THE SEASON………….691 DEPARTURE…….+37
TOTAL COOLING UNITS LAST SEASON TO DATE……..807 DEPARTURE……-116
PEAK WIND GUST (MPH):
Official……………….22 NE @ 9:46 A.M.
AEROVANE (south tower)…..23 NE @ 8:20 A.M.
VECTOR #2 (south tower)….24 @ 9:46 A.M.
DAVIS #2 (south tower)…..22 ENE @ 8:20 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 NE @ 9:49 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..15 @ 9:47 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 ENE @ 12:34 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
*LAST OF TWO OCCURRENCES
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……. 8.7 NE [208 total miles]
VECTOR #2…………….. 9.2
DAVIS #2……………… 9.1 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…….0.04 DEPARTURE….-0.11
TOTAL PRECIPITATION FOR THE MONTH………….5.35 DEPARTURE….+3.23
TOTAL PRECIPITATION FOR THE YEAR………….45.69 DEPARTURE….+9.22
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 The low since midnight is 62F, 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 18
HIGH 88F IN 1906
LOW 36F IN 1919
PRECIP 4.25 INCHES IN 1996
PEAK GUST 77e MPH WNW IN 1948
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
TODAY’S REPORT PREPARED BY: Matt Douglas
