Sunday, October 18, 2020
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
SUNDAY, OCTOBER 18, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME
A COOLER DAY WITH MOSTLY CLOUDY SKIES AND
GREAT VISIBILITY….
Today we observed mostly cloudy skies covered by a
translucent layer of cirrostratus clouds, which left
an uninterrupted burn on the sun card. Wind is south-
easterly, with a max gust of 20 mph and an average
speed barely exceeding 10 mph. Visibility was between
75 and 80 miles on average, while pressure is very
steadily decreasing between the 10 A.M. and 1 P.M.
observations.
The high so far today is 60F, the same as the daily
normal minimum. The low since midnight is 46F, 4 degrees
above the normal low of 42F.
PRELIMINARY STATS FOR SEPTEMBER 2020
TEMPERATURE, Deg. F
Avg. Max. 73.2 [+1.6]
Avg. Min. 54.9 [+0.3]
Mean 64.1 [+1.0]
24-hour corrected mean: 63.6
Max. for month: 82F on the 8th
Min. for month: 39F on the 22nd
HEATING DEGREE DAYS
Total heating units: 95 [-22]
Total for the season: 98 [-44]
Total for last season: 93
COOLING DEGREE DAYS
Total cooling units: 73 [+13]
Total for the season: 830 [+233]
Total for last season: 680
PRECIPITATION, Inches
Total: 1.61 [-2.45]
Greatest in 24 hrs: 1.02 ins. on 29th-30th
WIND, mph
Avg. uncorrected wind speed: 10.6 mph
Avg. corrected wind speed: 11.1 mph
Prevailing wind direction: S [20%]
Peak gust and direction: 71 S on the 30th
SUNSHINE:
Campbell-Stokes card minutes: 12150 minutes of a possible 21582 or 56%
Astronomical total minutes: 12593 minutes of a possible 22403 or 56%
Today’s Observations:
7 A.M.
Weather: Broken cirrostratus
Temperature: 48F; Dew Point: 34F; Relative Humidity: 57%
Wind: SE at 7 kts
Sea-level pressure: 30.55 ins. Hg: rising, then more slowly
Visibility: 80 miles
6-hr Max temp: 48F
6-hr Min temp: 46F
24-hr Precip: 0.03 ins.
BHO SA 1155 250 BKN 80 344/48/34/1407/055/ 8/008 70003
53013 10048 20046
10 A.M.
Weather: Broken cirrostratus
Temperature: 57F; Dew Point: 37F; Relative Humidity: 47%
Wind: SSE at 8G17 kts
Sea-level pressure: 30.56 ins. Hg: falling then rising
Visibility: 75 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 250 BKN 75 347/57/37/1508G17/056/ 8/008 50003
1 P.M.
Weather: Broken cirrostratus
Temperature: 59F; Dew Point: 34F; Relative Humidity: 38%
Wind: ESE at 8G15 kts
Sea-level pressure: 30.51 ins. Hg: falling steadily
Visibility: 75 miles
6-hr Max temp: 60F
6-hr Min temp: 48F
6-hr Precip: 0.00 inches
BHO SA 1755 250 BKN 75 331/59/34/1108G15/051/ 8/008 58016
10060 20048
SUMMARY FOR SATURDAY, OCTOBER 17, 2020
TEMPERATURE (DEGREES F)
MAX…..56 NORMAL…..60
MIN…..39 NORMAL…..42
MEAN….48 NORMAL…..51
DEPARTURE FROM 30-YEAR NORMAL……………..-3
TOTAL DEPARTURE FOR THE MONTH…………….+40 [+2.2 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….17 DEPARTURE….. +3
TOTAL HEATING UNITS FOR THE MONTH…………147 DEPARTURE…..-45
TOTAL HEATING UNITS FOR THE SEASON………..245 DEPARTURE…..-89
TOTAL HEATING UNITS LAST SEASON TO DATE……276 DEPARTURE…..-31
COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………. 0 DEPARTURE…… 0
TOTAL COOLING UNITS FOR THE MONTH…………. 1 DEPARTURE….. -4
TOTAL COOLING UNITS FOR THE SEASON………..831 DEPARTURE….+229
TOTAL COOLING UNITS LAST SEASON TO DATE……682 DEPARTURE….+149
PEAK WIND GUST FOR YESTERDAY (MPH)
420C/Official……………35 WNW AT 12:20 P.M.
AEROVANE (south tower)……40 WNW AT 9:56 A.M.
ASOS……………………35 NW AT 2:46 A.M.
DAVIS #1………………..36 WNW AT 12:02 P.M.
DAVIS #2 (south tower)……37 WNW AT 9:58 A.M.
RMY…………………….37
MERLIN………………….34
FASTEST MILE FOR YESTERDAY…………………25 WNW AT 12:03 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………23 WNW AT 12:23 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…………..25 WNW AT 12:23 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE…………..26 WNW AT 8:16 A.M.
AVERAGE WIND SPEED AND DIRECTION………….12.7 NNW [305 total miles]
ASOS………………….12.2
DAVIS #1………………12.8 NW [316 deg.]
DAVIS #2………………13.2 NW [320 deg.]
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.03 DEPARTURE….-0.12
ASOS…………..0.03
TOTAL PRECIPITATION FOR THE MONTH……….4.14 DEPARTURE….+1.62
ASOS…………..4.13
TOTAL PRECIPITATION FOR THE YEAR……….38.56 DEPARTURE….-3.04
ASOS………….39.34
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 76/59/68/0/0.00/698/88 22 SSE AERO 21 SE RMY 20
09/02 69/59/64/-4/0.18/102/13 23 SSE AERO 23 SSE RMY 24
09/03 75/66/71/+4/0.04/000/00 22 SSW AERO 21 SSW RMY N/A
09/04 82/62/72/+5/0.00/763/98 26 WNW AERO 26 WNW RMY 25
09/05 76/55/66/-1/0.00/760/98 25 W AERO 25 W RMY 24
09/06 78/58/68/+1/0.00/356/46 24 W AERO 24 W RMY N/A
09/07 79/61/70/+4/0.00/632/82 27 SSE AERO 30 SSE RMY 28
09/08 82/61/72/+6/0.00/545/71 17 S AERO 16 S RMY 17
09/09 80/62/71/+5/0.00/214/28 16 S AERO 15 S RMY 16
09/10 81/69/75/+10/0.28/015/02 21 SSW AERO 21 SSW RMY N/A
09/11 72/55/64/-1/0.01/152/20 25 N AERO 25 N RMY N/A
09/12 68/51/60/-5/0.00/666/88 21 ENE AERO 21 ENE RMY 21
09/13 74/53/64/0/0.00/611/81 26 SSW AERO 26 SSW RMY 26
09/14 74/50/62/-2/0.00/511/68 29 NNW AERO 33 NNW RMY 30
09/15 64/44/54/-10/0.00/583/78 18 S AERO 18 S RMY N/A
09/16 72/49/61/-2/0.00/603/81 31 SSW AERO 31 SSW RMY 31
09/17 76/57/67/+4/0.00/453/61 26 WSW AERO 28 W RMY N/A
09/18 64/48/56/-6/0.00/163/22 28 NE AERO 30 NNW RMY N/A
09/19 59/42/51/-11/0.00/722/98 23 N AERO 23 N RMY N/A
09/20 58/40/49/-13/0.00/602/82 25 NE AERO 25 NE RMY 27
09/21 61/41/51/-10/0.00/694/95 29 NE AERO 27 NE RMY 29
09/22 63/39/51/-10/0.00/022/03 28 NNW AERO 30 NNW RMY 29
09/23 78/50/64/+4/0.00/617/85 31 NW AERO 32 WNW RMY 32
09/24 76/57/67/+7/0.00/347/48 20 SW AERO 18 WSW RMY 19
09/25 77/57/67/+7/0.00/655/91 18 ENE AERO 18 WSW RMY N/A
09/26 77/57/67/+8/0.00/516/72 21 S AERO 21 S RMY 21
09/27 79/64/72/+13/0.01/121/17 24 S AERO 25 S RMY 24
09/28 78/64/71/+13/0.07/199/28 24 SSE AERO 24 S RMY 25
09/29 76/62/69/+11/0.01/234/33 30 S AERO 30 S RMY N/A
09/30 72/56/64/+6/1.01/395/56 71 S AERO 88 S RMY N/A
PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 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
10/01 75/56/66/+9/0.00/…/.. 28 SW AERO 28 SW RMY N/A
10/02 63/49/56/-1/0.02/…/.. 20 NW AERO 21 NW RMY 20
10/03 65/45/55/-1/0.00/…/.. 19 WNW AERO 19 WNW RMY 19
10/04 65/45/55/-1/0.00/…/.. 17 ESE AERO 18 ESE RMY 18
10/05 62/52/57/+1/0.00/…/.. 17 ENE AERO 17 ENE RMY N/A
10/06 69/51/60/+5/0.00/…/.. 28 S AERO 28 S RMY 29
10/07 73/50/62/+7/0.14/…/.. 76 W AERO 74 W RMY 70 TSTM
10/08 61/42/52/-2/0.00/…/.. 41 W AERO 41 W RMY N/A
10/09 60/37/49/-5/0.00/…/.. 25 SSW AERO 28 SSW RMY N/A
10/10 75/52/64/+10/0.00/…/.. 40 SSW AERO 40 SSW RMY 38
10/11 64/47/56/+3/0.00/…/.. 32 NNW AERO 35 NNW RMY N/A
10/12 52/48/50/-3/T/…/.. 28 E AERO 27 E RMY N/A
10/13 57/49/53/0/1.74/…/.. 32 E AERO 33 E RMY N/A
10/14 67/47/57/+5/0.00/…/.. 23 WNW AERO 25 WNW RMY N/A
10/15 71/50/61/+9/0.00/…/.. 43 S AERO 46 S RMY 42
10/16 68/48/58/+7/…./…/.. 28 S AERO 30 S RMY N/A
10/17 56/39/48/-3/…./…/.. 35 WNW AERO 40 WNW RMY 37
10/18 The low since midnight is 46F, the daily normal low is 42F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR OCTOBER 18
HIGH 82F IN 1908
LOW 26F IN 1939
PRECIP 2.79 INCHES IN 1975
SNOWFALL 3.0 INCHES IN 2009
PEAK GUST 66 MPH S IN 1967
RECORDS FOR OCTOBER 19
HIGH 81F IN 1945
LOW 21F IN 1922
PRECIP 3.64 INCHES IN 1932
SNOWFALL 1.0 INCHES IN 1972
PEAK GUST 66 MPH SSW IN 1967
TODAY’S REPORT PREPARED BY: Benjamin Turner
