Wednesday, July 15, 2020

BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

WEDNESDAY, JULY 15, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

PARTLY CLOUDY AND COOL WITH DECENT VISIBILITY
ATOP GREAT BLUE HILL….

It was foggy this morning, only allowing a
mile of visibility. The fog dissipated
quickly between 8 and 9 A.M., letting the
observer to see over 70 miles. Overnight
rainfall totaled 0.05 inches, making a
small contribution to the monthly deficit
of -0.79 inches. Cloudy cover decreased
considerably this morning, with sky
conditions being mostly clear by the 1 P.M.
observation.

Today was much cooler than the preceeding
days, barely reaching 70 degrees by 1 P.M.
This is 11 degrees below the daily normal
high of 81F. The low since midnight is 60F,
which is 3 degrees below the daily normal
low of 63F.

PRELIMINARY STATS FOR JUNE 2020

TEMPERATURE, Deg. F
Avg. Max. 78.0 [+3.0] Avg. Min. 59.1 [+2.0] Mean      68.6 [+2.5] 24-hour corrected mean: 67.5
Max. for month: 90F on the 20th
Min. for month: 42F on the 1st

HEATING DEGREE DAYS
Total heating units:     40 [-33] Total for the season:  5852 [-402] Total for last season: 6254

COOLING DEGREE DAYS
Total cooling units:    152  [+47] Total for the season:   184  [+55] Total for last season:  89

PRECIPITATION, Inches
Total: 7.56 [+3.25] Greatest in 24 hrs: 4.71 inches on the 28th-29th

WIND, mph
Avg. uncorrected wind speed: 9.1 mph
Avg. corrected wind speed:   9.8 mph
Prevailing wind direction:   S [15%] Peak gust and direction:     55 SW on the 6th

SUNSHINE:
Campbell-Stokes card minutes: 15996 minutes of a possible 26376 or 61%
Astronomical total minutes: 16650 minutes of a possible 27422 or 61%

Today’s Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 62F; Dew Point: 61F; Relative Humidity: 91%
Wind: NNE at 7 kts
Sea-level pressure: 30.20 ins. Hg: rising steadily
Visibility: 1 mile fog
6-hr Max temp: 63F
6-hr Min temp: 60F
24-hr Precip: 0.04 ins.
BHO SA 1155 E15 OVC 1F 228/62/61/0307/020/ 8/6// 70004 51015
10063 20060

10 A.M.
Weather: Overcast stratocumulus
Temperature: 67F; Dew Point: 62F; Relative Humidity: 84%
Wind: NE at 9 kts
Sea-level pressure: 30.21 ins. Hg: falling then rising
Visibility: 75 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E25 OVC 75 233/67/62/0509/021/ 8/8// 50005

1 P.M.
Weather: Scattered cumulus and stratocumulus
Temperature: 70F; Dew Point: 59F; Relative Humidity: 69%
Wind: ENE at 9 kts
Sea-level pressure: 30.26 ins. Hg: rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 71F
6-hr Min temp: 62F
6-hr Precip: 0.00 ins.
BHO SA 1755 E30 SCT 70 247/70/59/0609/026/ 8/8// 51014 10071 20062

SUMMARY FOR TUESDAY, JULY 14, 2020

TEMPERATURE (DEGREES F)
MAX…..78   NORMAL…..81
MIN…..63   NORMAL…..63
MEAN….71   NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL…………….. -1
TOTAL DEPARTURE FOR THE MONTH…………….. +25 [+1.6 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………..6   DEPARTURE……. -4
TOTAL COOLING UNITS FOR THE MONTH…………….114  DEPARTURE…….+21
TOTAL COOLING UNITS FOR THE SEASON……………298  DEPARTURE…….+76
TOTAL COOLING UNITS LAST SEASON TO DATE……….234  DEPARTURE…….+64

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..26 ENE AT  5:00 P.M.
AERO…………………….25 ENE AT  4:58 P.M.
ASOS…………………….27 ENE AT  5:01 P.M.
DAVIS……………………27 ENE AT  5:00 P.M RMY 26
FASTEST MILE FOR YESTERDAY………………….19 ENE AT  5:02 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 ENE AT  5:02 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………20 E   AT  5:01 P.M.
AVERAGE WIND SPEED AND DIRECTION………….. 8.2 ENE
ASOS………………….. 8.8
DAVIS…………………. 8.7 NE [48 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.04  DEPARTURE……-0.10
ASOS…………..0.04
TOTAL PRECIPITATION FOR THE MONTH……….0.87  DEPARTURE……-0.79
ASOS…………..0.86
TOTAL PRECIPITATION FOR THE YEAR……….28.22  DEPARTURE……-0.41
ASOS………….28.87

PRELIMINARY CLIMATE SUMMARY FOR JUNE 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

06/01  64/42/53/-9/T/0.0/724/80            28 WNW  AERO 29 WNW RMY 28
06/02  72/45/59/-3/…./0.0/689/76         28 W    AERO 27 W   RMY 28
06/03  79/55/67/+5/T/0.0/400/44            29 W    AERO 28 W   RMY 26
06/04  87/62/75/+12/…./0.0/673/74        26 W    AERO 25 S   RMY N/A
06/05  80/65/73/+10/…./0.0/300/33        28 SSW  AERO 28 SSW RMY N/A TSTM
06/06  86/57/72/+9/…./0.0/301/33         55 SW   AERO 59 SW  RMY 59  TSTM
06/07  68/54/61/-3/0.00/0.0/255/28         24 NW   AERO 24 NW  RMY N/A
06/08  77/51/64/0/0.00/0.0/866/95          25 W    AERO 24 W   RMY 25
06/09  77/60/69/+5/T/0.0/110/12            23 E    AERO 21 E   RMY N/A
06/10  70/58/64/-1/T/0.0/658/72            25 E    AERO 24 E   RMY N/A
06/11  71/64/68/+3/0.62/0.0/165/18         40 S    AERO 40 S   RMY 42
06/12  82/63/73/+8/0.00/0.0/705/77         26 W    AERO 25 W   RMY 27
06/13  71/53/62/-3/0.00/0.0/669/73         21 WNW  AERO 20 WNW RMY N/A
06/14  67/49/58/-8/0.00/0.0/852/93         21 E    AERO 21 ENE RMY 21
06/15  67/53/60/-6/5/0/0.0/696/76          21 NE   AERO 16 ENE RMY 20
06/16  73/54/64/-2/0.00/0.0/889/97         18 E    AERO 18 E   RMY 18
06/17  78/57/68/+1/0.00/0.0/889/97         20 S    AERO 20 S   RMY 20
06/18  86/59/73/+6/0.00/0.0/715/78         22 S    AERO 22 SSW RMY 22
06/19  86/66/76/+9/0.00/0.0/789/86         22 S    AERO 22 S   RMY 21
06/20  90/65/78/+10/0.00/0.0/834/91        22 S    AERO 21 S   RMY 21
06/21  90/66/78/+10/0.83/0.0/514/56        33 ESE  AERO 35 ESE RMY 33  TSTM
06/22  77/65/71/+3/0.00/0.0/761/83         15 E    AERO 17 S   RMY 14
06/23  85/65/75/+7/0.00/0.0/431/47         27 S    AERO 24 S   RMY 26
06/24  84/66/75/+6/0.00/0.0/348/38         25 S    AERO 24 S   RMY 25
06/25  84/63/74/+5/0.00/0.0/806/88         29 W    AERO 29 W   RMY 29
06/26  83/65/74/+5/0.02/0.0/769/84         25 S    AERO 25 S   RMY 27
06/27  82/65/74/+5/0.05/0.0/330/36         21 S    AERO 20 S   RMY 20
06/28  84/62/73/+3/3.27/0.0/421/46         35 W    AERO 33 N   RMY 37  TSTM
06/29  71/61/66/-4/…./0.0/064/07         18 NE   AERO 18 NE  RMY 18  TSTM
06/30  68/62/65/-5/…./…/027/03         14 ENE  AERO 14 ENE RMY 13

Record rainfall on the 28th of 3.27″. Old record 2.09″ in 1938

PRELIMINARY CLIMATE SUMMARY FOR JULY 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

07/01  76/63/70/0/0.00/228/25              16 E    AERO 14 E   RMY 14  TSTM
07/02  86/61/74/4/0.00/803/88              30 WSW  AERO 25 WSW RMY 33
07/03  73/60/67/-4/0.00/091/10             30 NE   AERO 28 NE  RMY 30
07/04  79/60/70/-1/0.00/565/62             16 S    AERO 16 S   RMY 16
07/05  83/63/73/+2/0.54/373/41             24 NW   AERO 30 NW  RMY 26  TSTM
07/06  73/60/67/-4/0.00/…/..             20 ENE  AERO 16 NNE RMY 18
07/07  78/60/69/-2/0.00/…/..             25 S    AERO 25 S   RMY 26
07/08  83/64/74/+2/0.00/…/..             32 SSW  AERO 32 SSW RMY 32
07/09  89/70/80/+8/0.00/…/.              24 S    AERO 23 S   RMY 22
07/10  83/70/77/+5/0.05/…/..             30 SSE  AERO 32 SSE RMY N/A
07/11  85/70/78/+6/0.00/…/..             39 S    AERO 39 S   RMY 38
07/12  86/70/78/+6/0.00/…/..             28 WSW  AERO 28 WSW RMY 29
07/13  82/69/76/+4/0.23/…/..             30 SSE  AERO 31 SSE RMY 30  TSTM
07/14  78/63/71/-1/0.00/…/..             26 ENE  AERO 25 ENE RMY 26

07/15 The low since midnight is 60F, the daily normal low is 63F

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR JULY 15
HIGH 94F IN 1995
LOW 50F IN 1929, 1930
PRECIP 1.64 INS IN 1896
WIND 71 MPH WNW IN 2002

RECORDS FOR JULY 16
HIGH 94F IN 1968, 1980, 1983, 1999
LOW 50F IN 1889, 1903
PRECIP 0.97 INS IN 2014
WIND 48e MPH SW 1944

TODAY’S REPORT PREPARED BY: Benjamin Turner