Friday, October 9, 2020

| October 9, 2020 | Reply

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

FRIDAY, OCTOBER 9, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

A DAZZLING FALL DAY ATOP GREAT BLUE HILL…

Clear skies, light winds, and temperatures in the upper-30s
were found here upon our arrival. The low bottomed out at
37 degrees marking the coldest air of the season. The last
time the temperature reached 37 or below was back on
May 13th…149 days or just under 5 months ago! Visibility
has been astounding – horizon to horizon – averaging 85 miles
throughout the day.

Fall colors are also becoming more visible around us. The
Neponset River Valley is exhibiting the most advanced and
vibrant colors thanks to its low-lying elevation allowing
for superb radiational cooling on clear, calm nights.

The high so far today is 57, 6 degrees below the daily
normal of 63F. The low since midnight is 48F, which is
2 degrees above the normal low of 45F.

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: Clear (few cumulus E & S; few altocumulus SSW-WSW)
Temperature: 40F; Dew Point: 30F; Relative Humidity: 68%
Wind: NW at 9 kts
Sea-level pressure: 30.21 ins. Hg: rising, then rising more rapidly
Visibility: 85 miles
6-hr Max temp: 42F
6-hr Min temp: 37F
24-hr Precip: 0.00 ins.
BHO SA 1155 CLR 85 231/40/30/3209/021/ FEW CU DSNT E AND S
FEW AC DSNT SSW-WSW/ 8/150 53025 10042 20037

10 A.M.
Weather: Clear
Temperature: 52F; Dew Point: 21F; Relative Humidity: 29%
Wind: NNW at 9G13 kts
Sea-level pressure: 30.24 ins. Hg: rising, then rising more slowly
Visibility: 85 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 85 240/52/21/3309G13/024/ 8/000 51009

1 P.M.
Weather: Clear (few cumulus S-SW; few cirrus S-SW)
Temperature: 56F; Dew Point: 25F; Relative Humidity: 29%
Wind: WNW at 9G16 kts
Sea-level pressure: 30.18 ins. Hg: falling, then falling more rapidly
Visibility: 85 miles
6-hr Max temp: 57F
6-hr Min temp: 40F
6-hr Precip: 0.00 ins.
BHO SA 1755 CLR 85 219/56/25/2909G16/018/ FEW CU DSNT S-SW
FEW CI DSNT S-SW 8/101 58021 10057 20040

SUMMARY FOR THURSDAY, OCTOBER 8, 2020

TEMPERATURE (DEGREES F)
MAX…..61   NORMAL…..63
MIN…..42   NORMAL…..46
MEAN….52   NORMAL…..54

DEPARTURE FROM 30-YEAR NORMAL……………..-2
TOTAL DEPARTURE FOR THE MONTH…………….+17 [+1.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….13  DEPARTURE……+2
TOTAL HEATING UNITS FOR THE MONTH………….58  DEPARTURE…..-19
TOTAL HEATING UNITS FOR THE SEASON………..156  DEPARTURE…..-64
TOTAL HEATING UNITS LAST SEASON TO DATE……169  DEPARTURE…..-13

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………. 0  DEPARTURE…….0
TOTAL COOLING UNITS FOR THE MONTH…………..1  DEPARTURE….. -2
TOTAL COOLING UNITS FOR THE SEASON………..831  DEPARTURE….+231
TOTAL COOLING UNITS LAST SEASON TO DATE……682  DEPARTURE….+149

PEAK WIND GUST FOR YESTERDAY (MPH)
420C/Official…………….41 W  AT  12:06 A.M.
AERO…………………….41 W  AT  12:02 A.M.
ASOS…………………….40 W  AT  12:06 A.M.
DAVIS……………………42 W  AT  12:05 A.M.
RMY N/A  MERLIN N/A
FASTEST MILE FOR YESTERDAY………………….28 W  AT  12:07 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….29 W  AT  12:07 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………31 W  AT  12:07 A.M.
AVERAGE WIND SPEED AND DIRECTION………….15.7 WNW (376 total miles)
ASOS………………….15.1
DAVIS…………………15.9 WNW [299 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE….-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.16  DEPARTURE….-1.03
ASOS…………..0.12
TOTAL PRECIPITATION FOR THE YEAR……….34.58  DEPARTURE….-5.69
ASOS………….35.33

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
10/08  61/42/52/-2/0.00/…/..             41 W    AERO 41 W    RMY N/A

10/09  The low since midnight is 37F, the daily normal low is 45F

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

RECORDS FOR OCTOBER 9
HIGH 82F IN 2011
LOW 29F IN 1907,1937
PRECIP 2.54 INCHES IN 1976
SNOWFALL 0.2 INCHES IN 1888
PEAK GUST 81e MPH S IN 1976 (RECORD FOR MONTH)

RECORDS FOR OCTOBER 10
HIGH 85F IN 1949
LOW 27F IN 1929
PRECIP 2.02 INCHES IN 1998
SNOWFALL 6.8 INCHES IN 1979 (RECORD FOR MONTH)
PEAK GUST 59 MPH WNW IN 1958

TODAY’S REPORT PREPARED BY: Andrew Swanson

Category: Daily Discussions

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