Monday, August 21, 2017
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, AUGUST 21, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME
PARTIAL SOLAR ECLIPSE AT THE BLUE HILL OBSERVATORY
A partial solar eclipse was visible from Great Blue Hill today, with a
maximum of about 63% of the sun covered by the moon. The eclipse began
at approximately 12:28 P.M. Eastern Standard Time. The maximum was at
1:46 P.M. EST, and the eclipse ended at 2:59 P.M. EST. Broken cirrus was
in the sky for the whole duration of the eclipse, and a few cumulus and
altocumulus moved in towards the second half. The sun was able to shine
through the clouds for most of the time, so people at Blue Hill were able
to view the eclipse.
Extra temperature observations were recorded every half hour during the
eclipse. The temperature did go down during the eclipse, but some of the
cooling could be due to more cloud cover.
All times are in Eastern Standard Time:
12:00 P.M. – 83.9F
83.7F – 12:28 P.M. (Start of Eclipse)
12:30 P.M. – 83.5F
1:00 P.M. – 83.7F
1:30 P.M. – 81.4F
81.8F – 1:46 P.M. (Maximum Coverage)
2:00 P.M. – 80.9F
2:30 P.M. – 82.4F
83.3F – 2:59 P.M. (End of Eclipse)
3:00 P.M. – 83.5F
3:30 P.M. – 82.4F
4:00 P.M. – 81.8F
85.2F – Maximum before eclipse
80.7F – Minimum during eclipse
85.3F – Maximum after eclipse
The temperature dropped about 4.5F during the eclipse, and it went up again
to roughly the same temperature after. Eclipses historically have occurred
on cool days at Blue Hill. Previously, the warmest day with a solar eclipse
was July 9, 1945 where a maximum temperature of 83F was reached. However,
the maximum of 85F reached today makes it the warmest day with an eclipse
on record.
Today’s Observations:
7 A.M.
Weather: Scattered cirrus
Temperature: 68F; Dew Point: 58F; Wind: WNW at 9 kts
Sea-level pressure: 30.17 ins. Hg, rising, then less quickly
Visibility: 25 miles, hazy
6-hr Max temp: 68F
6-hr Min temp: 63F
24-hr precip: 0.00 in.
BHO SA 1155 250 SCT 25 218/68/58/2909/017/ HAZY/ 8/001 51011 10068 20063
10 A.M.
Weather: Broken cirrus
Temperature: 80F; Dew Point: 61F; Wind: Estimated SW at 3 kts,
Wind Speed: Light
Sea-level pressure: 30.16 ins. Hg, steady, then falling
Visibility: 25 miles, hazy
BHO SA 1455 E250 BKN 25 214/80/61/E2203/016/ HAZY WND LGT/ 8/002 57004
1 P.M.
Weather: Few cumulus in all directions, few altocumulus in all directions,
broken cirrus
Temperature: 84F; Dew Point: 61F; Wind: WSW at 9G15 kts
Sea-level pressure: 30.13 ins. Hg, falling unsteadily
Visibility: 25 miles, hazy
6-hr Max temp: 85F
6-hr Min temp: 68F
BHO SA 1755 E250 BKN 25 202/84/61/2509G15/013/ FEW CU ALQDS FEW AC ALQDS
HAZY/ 8/102 58012 10085 20068
SUMMARY FOR SUNDAY, AUGUST 20, 2017
TEMPERATURE (DEGREES F)
MAX…..84 NORMAL…..79
MIN…..66 NORMAL…..62
MEAN….75 NORMAL…..70
DEPARTURE FROM 30-YEAR NORMAL…………………….+5
TOTAL DEPARTURE FOR THE MONTH……………………+21 [+0.9 DEGREES/DAY]
COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..10 DEPARTURE……….+4
TOTAL COOLING UNITS FOR THE MONTH………….147 DEPARTURE………+14
TOTAL COOLING UNITS FOR THE SEASON…………568 DEPARTURE………+84
TOTAL COOLING UNITS LAST SEASON TO DATE…….693 DEPARTURE……..-125
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….23 NW AT 4:48 P.M.
AERO……………………25 NW AT 4:49 P.M.
ASOS……………………26 NW AT 4:50 P.M.
DAVIS…………………..24 NW AT 4:49 P.M. RMY 27
FASTEST MILE FOR YESTERDAY…………………19 NW AT 4:50 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………18 NW AT 4:50 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..18 WNW AT 1:02 P.M.
AVERAGE WIND SPEED AND DIRECTION………….11.5 WNW
ASOS………………….11.6
DAVIS………………….9.9 WNW [288 DEG.]
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00 DEPARTURE……-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.40 DEPARTURE……-1.35
ASOS…………..1.38
TOTAL PRECIPITATION FOR THE YEAR……….36.16 DEPARTURE……+2.42
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings
PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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
8/1 87/65/76/+4/0.00/762/88 16 ESE*AERO 16 NNW RMY 16
8/2 86/65/76/+4/1.09/372/43 32 W AERO 36 W RMY 34 TSTM
8/3 83/65/74/+2/0.00/552/64 22 S AERO 23 S RMY 24
8/4 84/66/75/+3/0.00/697/81 26 S AERO 30 S RMY 29
8/5 75/63/69/-3/0.10/060/07 23 NW AERO 28 NW RMY 29
8/6 76/57/67/-5/0.00/795/93 30 NW AERO 32 NW RMY 31
8/7 76/60/68/-4/0.01/597/70 28 SSW AERO 28 SSW RMY 29
8/8 74/60/67/-5/0.02/000/00 17 S AERO 16 SSE RMY 16
8/9 83/58/71/-1/0.00/…/.. 18 S AERO 18 S RMY 19
8/10 86/63/75/+4/T/…/.. 20 S AERO 18 S RMY 20
8/11 82/63/73/+2/0.00/…/.. 17 S AERO 16 S RMY 17
8/12 75/57/66/-5/0.17/…/.. 22 SSW*AERO 22 SSW RMY 23
8/13 84/67/76/+5/0.00/…/.. 26 WNW AERO 24 WNW RMY 26
8/14 82/67/75/+4/0.00/…/.. 14 SSW*AERO 14 S RMY 15
8/15 79/64/72/+1/T/…/.. 21 S AERO 21 S RMY 23
8/16 83/64/74/+3/0.00/…/.. 23 NW* AERO 23 NW RMY 25
8/17 81/58/70/-1/0.00/…/.. 15 SSW AERO 14 SSW RMY N/A
8/18 79/63/71/0/…./…/.. 33 S AERO 35 S RMY 35
8/19 89/65/77/+7/0.00/…/.. 23 WSW AERO 23 WSW RMY 25
8/20 84/66/75/+5/0.00/…/.. 23 NW AERO 25 NW RMY 27
8/21 Low temp since midnight is 63F; normal low is now 62F
DAILY RECORDS FOR AUGUST
None so far.
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR AUGUST 21
HIGH 92F IN 1937, 1995
LOW 47F IN 1982
PRECIP 2.84 INCHES IN 1888
PEAK GUST 54 MPH WSW IN 2004
RECORDS FOR AUGUST 22
HIGH 90F IN 1939
LOW 42F IN 1894
PRECIP 2.28 INCHES IN 1935
PEAK GUST 44 MPH SSW IN 1987
TODAY’S REPORT PREPARED BY: Lizzy Suzedell
