Sunday, September 13, 2020

| September 14, 2020 | Reply

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

SUNDAY, SEPTEMBER 13, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

ANOTHER COOL AND FAIR WEATHER DAY WITH WIND
PICKING UP SLIGHTLY IN THE AFTERNOON….

Today we observed mostly cloudy skies, which opened up
a little more in the afternoon. Visibility was limited
to 10 miles this morning from fog, but increased to 65
miles by the 1 P.M. observation. Pressure has dropped
by more than 5 millibars in the past 6 hours, which is
odd considering there are less clouds now than earlier.
It is surely drier at the hill now, with a dew point
in the mid 50’s and a relative humidity of 50%.

The high since midnight is 74F, a degree above the daily
normal max of 73F. The low since midnight is 53F, which
is 3 degrees below the normal low of 56F.

PRELIMINARY STATS FOR AUGUST 2020

TEMPERATURE, Deg. F
Avg. Max. 82.5 [+3.3]
Avg. Min. 64.3 [+2.5]
Mean      73.4 [+2.9]
24-hour corrected mean: 72.3
Max. for month: 94F on the 10th
Min. for month: 54F on the 31st

HEATING DEGREE DAYS
Total heating units:     2 [-14]
Total for the season:    3 [-22]
Total for last season:  12

COOLING DEGREE DAYS
Total cooling units:    270  [+84]
Total for the season:   757  [+220]
Total for last season:  622

PRECIPITATION, Inches
Total: 3.74 [-0.29]
Greatest in 24 hrs: 2.21 ins. on the 23rd

WIND, mph
Avg. uncorrected wind speed: 10.0 mph
Avg. corrected wind speed:   10.6 mph
Prevailing wind direction:   SSW [12%]
Peak gust and direction:     67 SSE on the 4th

SUNSHINE:
Campbell-Stokes card minutes: 15366 minutes of a possible 24780 or 62%
Astronomical total minutes: 15940 minutes of a possible 25709 or 62%

Today’s Observations:

7 A.M.
Weather: Broken stratocumulus and cirrus
Temperature: 57F; Dew Point: 56F; Relative Humidity: 95%
Wind: NNE at 3 kts, light and variable
Sea-level pressure: 30.24 ins. Hg: rising, then falling
Visibility: 10 miles, thin fog
6-hr Max temp: 57F
6-hr Min temp: 53F
24-hr Precip: 0.00 ins.
BHO SA 1155 35 BKN 250 BKN 10 242/57/56/1503/024/ THN FG ALQDS WND
L/V/ 8/701 55001 10057 20053

10 A.M.
Weather: Broken cumulus and cirrus
Temperature: 67F; Dew Point: 57F; Relative Humidity: 71%
Wind: SSE at 7 kts
Sea-level pressure: 30.19 ins. Hg: falling steadily
Visibility: 35 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 35 BKN 250 BKN 35 227/67/57/1607/019/ HAZY/ 8/701 57015

1 P.M.
Weather: Scattered cumulus, scattered cirrostratus
Temperature: 73F; Dew Point: 55F; Relative Humidity: 54%
Wind: S at 11G18 kts
Sea-level pressure: 30.10 ins. Hg: falling, then more rapidly
Visibility: 65 miles
6-hr Max temp: 74F
6-hr Min temp: 57F
6-hr Precip: 0.00 ins.
BHO SA 1755 35 SCT 250 SCT 65 197/73/55/1911G18/010/ 8/105
58030 10074 20057

SUMMARY FOR SATURDAY, SEPTEMBER 12, 2020

TEMPERATURE (DEGREES F)
MAX…..68   NORMAL…..73
MIN…..51   NORMAL…..56
MEAN….60   NORMAL…..65

DEPARTURE FROM 30-YEAR NORMAL……………. -5
TOTAL DEPARTURE FOR THE MONTH……………. +19 [+2.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..5  DEPARTURE……+2
TOTAL HEATING UNITS FOR THE MONTH…………..7  DEPARTURE…..-17
TOTAL HEATING UNITS FOR THE SEASON…………10  DEPARTURE…..-39
TOTAL HEATING UNITS LAST SEASON TO DATE…….32  DEPARTURE…..-23

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………  0  DEPARTURE……-2
TOTAL COOLING UNITS FOR THE MONTH………… 48  DEPARTURE…..+11
TOTAL COOLING UNITS FOR THE SEASON………..805  DEPARTURE….+237
TOTAL COOLING UNITS LAST SEASON TO DATE……642  DEPARTURE….+163

PEAK WIND GUST FOR YESTERDAY (MPH)
420C/Official…………….21 ENE AT 11:04 A.M.
AERO…………………….21 ENE AT 11:12 A.M.
ASOS…………………….22 ENE AT 10:12 A.M.
DAVIS……………………22 E   AT 11:02 A.M.
RMY 21  MERLIN 21
FASTEST MILE FOR YESTERDAY………………….16 ENE AT 10:16 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 ENE AT 10:12 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………16 E   AT 10:12 A.M.
AVERAGE WIND SPEED AND DIRECTION……………9.5 NNE
ASOS……………………9.5
DAVIS…………………..10.1 E [86 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……….0.52  DEPARTURE….-0.96
ASOS…………..0.51
TOTAL PRECIPITATION FOR THE YEAR……….33.33  DEPARTURE….-3.17
ASOS………….34.09

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

08/01  87/66/77/+5/0.00/866/100            18 S    AERO 21 S    RMY 19
08/02  85/69/77/+5/0.02/320/37             36 S    AERO 37 S    RMY 38
08/03  91/75/83/+11/0.00/715/83            36 WSW  AERO 38 SW   RMY 36
08/04  83/71/77/5/0.21/094/11              67 SSE  AERO 71 S    RMY 70
08/05  90/68/79/+7/0.00/668/78             28 SW   AERO 30 SW   RMY 29
08/06  84/65/75/3/0.00/701/82   20 W    AERO 17 W    RMY 19
08/07  79/65/72/0/T/136/16                 16 NE   AERO 16 NE   RMY N/A
08/08  83/64/74/+2/0.00/612/72             20 S    AERO 20 S    RMY 19
08/09  90/65/78/+6/0.00/661/78             26 SSW  AERO 26 SSW  RMY 26
08/10  94/69/82/+11/0.00/727/86            22 W    AERO 20 W    RMY 20
08/11  92/72/82/+11/0.00/708/84            31 SSW  AERO 35 SSW  RMY 31  TSTM
08/12  93/74/84/+13/0.00/647/77            22 SSW  AERO 22 SW   RMY 19
08/13  88/71/80/+9/0.00/528/63             18 ENE  AERO 18 NE   RMY 18
08/14  82/67/75/+4/0.00/618/74             23 ENE  AERO 23 ENE RMY N/A
08/15  67/62/65/-6/T/000/00                33 NNE  AERO 32 NNE  RMY N/A
08/16  69/62/66/-5/0.34/000/00             26 ENE  AERO 28 ENE  RMY 26
08/17  73/59/66/-5/0.04/339/41             25 NE   AERO 24 NE   RMY N/A
08/18  84/63/74/+3/0.23/784/95             23 W    AERO 23 W    RMY 24
08/19  81/59/70/0/0.03/526/64              26 W    AERO 28 W    RMY 27
08/20  80/56/68/-2/0.00/804/98             22 W    AERO 21 W    RMY 22
08/21  88/61/75/+5/0.00/719/88             28 SW   AERO 26 SW   RMY 28
08/22  85/66/76/+6/0.26/521/64             18 NNE  AERO 16 S    RMY 16
08/23  89/63/76/+6/2.21/552/68             60 WNW  AERO 53 WNW  RMY 58  TSTM HAIL
08/24  87/67/77/+7/0.00/493/61             18 S    AERO 18 S    RMY 19  TSTM
08/25  86/65/76/+7/0.01/492/61             35 NNW  AERO 37 NNW  RMY 35
08/26  74/56/65/-4/0.00/780/97             29 NW   AERO 32 NW   RMY N/A
08/27  68/57/63/-6/0.33/008/01             18 SSE  AERO 20 SSE  RMY 20  TSTM
08/28  80/59/70/+1/0.00/559/70             20 W    AERO 20 W    RMY N/A
08/29  74/65/70/+1/0.06/000/00             32 W    AERO 32 W    RMY N/A
08/30  75/57/66/-2/0.00/793/100            36 W    AERO 36 W    RMY N/A
08/31  75/54/65/-3/0.00/569/72             20 S    AERO 20 S    RMY 20

DAILY RECORDS FOR AUGUST 2020

8/23/20: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 89F,
BREAKS PREVIOUS RECORD of 88F SET IN 1918, 1947, 1949, 1996

8/23/20: DAILY RECORD PRECIPITATION OF 2.21 INS,
BREAKS PREVIOUS RECORD OF 2.09 INS SET IN 2010

8/23/20: DAILY RECORD PEAK WIND GUST OF 60 MPH,
TIES PREVIOUS RECORD OF 60 MPH SET IN 1940

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/…/..              22 SSE  AERO 21 SE   RMY 20
09/02  69/59/64/-4/…/…/..              23 SSE  AERO 23 SSE  RMY 24
09/03  75/66/71/+4/…/…/..              22 SSW  AERO 21 SSW  RMY n/a
09/04  82/62/72/+5/0.00/…/..             26 WNW  AERO 26 WNW  RMY 25
09/05  76/55/66/-1/0.00/…/..             25 W    AERO 25 W    RMY 24
09/06  78/58/68/+1/0.00/…/..             24 W    AERO 24 W    RMY n/a
09/07  79/61/70/+4/0.00/…/..             27 SSE  AERO 30 SSE  RMY 28
09/08  82/61/72/+6/0.00/…/..             17 S    AERO 16 S    RMY 17
09/09  80/62/71/+5/0.00/…/..             16 S    AERO 15 S    RMY 16
09/10  81/69/75/+10/0.29/…/..            21 SSW  AERO 21 SSW  RMY n/a
09/11  72/55/64/-1/0.01/…/..             25 N    AERO 25 N    RMY N/A
09/12  68/51/60/-5/0.00/…/..             21 ENE  AERO 21 ENE  RMY 21

09/13 The low since midnight is 53F, the daily normal low is 56F

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

RECORDS FOR SEPTEMBER 13
HIGH 91F IN 1957
LOW 40F IN 1985
PRECIP 3.10 INCHES IN 1987
PEAK GUST 44 MPH WNW IN 1986

RECORDS FOR SEPTEMBER 14
HIGH 90F IN 1931
LOW 34F IN 1911
PRECIP 4.38 INCHES IN 1944 (Great Atlantic Hurricane in 1944)
PEAK GUST 96e MPH E IN 1944 (Great Atlantic Hurricane in 1944)

TODAY’S REPORT PREPARED BY: Benjamin Turner

Category: Daily Discussions

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