Saturday, July 18, 2020

| July 18, 2020 | Reply

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

SATURDAY, JULY 18, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

MUCH IMPROVED FROM YESTERDAY – SUN AND HEAT
TAKE THE HELM ATOP GREAT BLUE HILL…

A complete 180 from yesterday’s cool, damp
and grey conditions. Those temperatures were
more reflective of mid-September…we even picked
up 1 heating degree day (HDD)! Today, clear
skies and rapidly warming temperatures greeted
us here upon arrival. Temperatures continued to
climb throughout the day reaching 87 degrees by
1 PM under the abundant sunshine. Higher dew
points have made their comeback, too, albeit
slipping a bit from the upper-60s this morning
to the mid-60s by early afternoon. Winds have
remained rather gentle only capping out at
14 MPH so far.

On an interesting note, we recorded “clear” skies
as the dominant weather for all 3 consecutive
observation periods today. The last day we
experienced this streak was back on June 17, 2020
– just over 1 month ago!

The high so far today is 87 degrees. This is
6 degrees above the daily normal high of 81F.
The low since midnight is 66F, which is 3 degrees
above 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: Clear
Temperature: 72F; Dew Point: 68F; Relative Humidity: 88%
Wind: NW at 6 kts (wind light)
Sea-level pressure: 30.07 ins. Hg: rising unsteadily
Visibility: 65 miles; hazy
6-hr Max temp: 72F
6-hr Min temp: 66F
24-hr Precip: 0.01 ins.
BHO SA 1155 CLR 65 182/72/68/3406/007/ HAZY WND LGT/ 8/000
52001 70001 10072 20066

10 A.M.
Weather: Clear (few cumulus)
Temperature: 83F; Dew Point: 68F; Relative Humidity: 62%
Wind: WSW at 6 kts (wind light)
Sea-level pressure: 30.06 ins. Hg: rising, then falling
Visibility: 50 miles, hazy
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 50 182/83/68/2506/007/ FEW CU DSNT ALQDS HAZY WND LGT/
8/100 50000

1 P.M.
Weather: Clear (few cumulus)
Temperature: 85F; Dew Point: 64F; Relative Humidity: 50%
Wind: SSW at 7 kts
Sea-level pressure: 30.02 ins. Hg: falling, then more slowly
Visibility: 65 miles, hazy
6-hr Max temp: 87F
6-hr Min temp: 72F
6-hr Precip: 0.00 ins.
BHO SA 1755 CLR 65 169/85/64/2107/003/ FEW CU ALQDS HAZY/
8/100 56013 10087 20072

SUMMARY FOR FRIDAY, JULY 17, 2020

TEMPERATURE (DEGREES F)
MAX…..71   NORMAL…..81
MIN…..57   NORMAL…..63
MEAN….64   NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL…………….. -8
TOTAL DEPARTURE FOR THE MONTH…………….. +4 [+0.0 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………….. 0  DEPARTURE……. -7
TOTAL COOLING UNITS FOR THE MONTH…………….115  DEPARTURE……. +1
TOTAL COOLING UNITS FOR THE SEASON……………299  DEPARTURE…….+56
TOTAL COOLING UNITS LAST SEASON TO DATE……….268  DEPARTURE…….+31

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..24 SSW AT  1:47 P.M.
AERO…………………….24 SSW AT  1:43 P.M.
ASOS…………………….25 S   AT  1:47 P.M.
DAVIS……………………25 SSW AT  1:46 P.M RMY 25
FASTEST MILE FOR YESTERDAY………………….17 SSW AT  1:48 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 SSW AT  1:50 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………17 SSW AT  1:47 P.M.
AVERAGE WIND SPEED AND DIRECTION………….. 9.7 S
ASOS………………….. 9.6
DAVIS…………………. 9.7 SSW [199 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.01  DEPARTURE……-0.12
ASOS…………..0.02
TOTAL PRECIPITATION FOR THE MONTH……….1.06  DEPARTURE……-1.01
ASOS…………..1.06
TOTAL PRECIPITATION FOR THE YEAR……….28.41  DEPARTURE……-0.63
ASOS………….29.07

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/-3/0.01/0.0/689/76         28 W    AERO 27 W   RMY 28
06/03  79/55/67/+5/0.00/0.0/400/44         29 W    AERO 28 W   RMY 26
06/04  87/62/75/+12/0.00/0.0/673/74        26 W    AERO 25 S   RMY N/A
06/05  80/65/73/+10/0.14/0.0/300/33        28 SSW  AERO 28 SSW RMY N/A TSTM
06/06  86/57/72/+9/1.14/0.0/301/33         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/-1/0.00/0.0/658/72         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/-6/5/0.00/0.0/696/76       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/T/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/-4/1.46/0.0/064/07         18 NE   AERO 18 NE  RMY 18  TSTM
06/30  68/62/65/-5/0.02/0.0/027/03         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  72/59/66/-6/0.00/…/..             21 NE   AERO 21 NE   RMY N/A
07/16  73/57/65/-7/0.00/…/..             21 E    AERO 21 E    RMY 19
07/17  71/57/64/-8/0.19/…/..             24 SSW  AERO 24 SSW  RMY 25

07/18 The low since midnight is 66F, 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 18
HIGH 96F IN 1991, 1999
LOW 54F IN 1892, 1956, 1971
PRECIP 1.65 INS IN 2000
WIND 43e MPH SW IN 1949

RECORDS FOR JULY 19
HIGH 96F IN 1977, 1991
LOW 50F IN 1890
PRECIP 1.10 INS IN 1951
WIND 63 MPH SSW IN 1982

TODAY’S REPORT PREPARED BY: Andrew Swanson

Category: Daily Discussions

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