Friday, October 16, 2020

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

FRIDAY, OCTOBER 16, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

A DETERIORATING DAY ATOP GREAT BLUE HILL….

What began with overcast skies and a visibility of
20 miles slowly progressed to thick fog and a
visibility of 2 miles at best by early afternoon.
A few sprinkles also moved in during the morning
before heavier rainfall settled in by early afternoon.
Winds have eased from yesterday’s peak of 43 MPH and
average of 17 MPH. Max gust so far is 27 MPH with an
average of 11 MPH.

The low through 12:30 PM was 60 degrees. This temporarily
tied for the 3rd highest minimum temperature on record
before a cold front swept through the region rapidly
knocking temperatures down to 55 degrees by the 1 PM
observation. Moderate precipitation immediately followed
the abrupt frontal passage. Fun Fact: This front is
classified as a “anafront” due to the precipitation being
situated along and behind the cold front. We anticipate the
beneficial rainfall to extend into tomorrow morning.

The high so far today is 69F, 9 degrees above the daily
normal of 60F. The low since midnight is 55F, 12 degrees
above the normal low of 43F.

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: Overcast Stratus Fractus (higher clouds visible NE-ESE)
Temperature: 63F; Dew Point: 62F; Relative Humidity: 96%
Wind: SSE at 11 kts
Sea-level pressure: 30.05 ins. Hg: rising, then rising more slowly
Visibility: 20 miles (thin fog)
6-hr Max temp: 63F
6-hr Min temp: 61F
24-hr Precip: 0.00 ins.
BHO SA 1155 E17 OVC 20 175/63/62/1611/005/ HIR CLDS VSB DSNT NE-ESE
THN F ALQDS/ 8/6// 51005 10063 20061

10 A.M.
Weather: Overcast Stratus Fractus
Temperature: 65F; Dew Point: 64F; Relative Humidity: 96%
Wind: S at 12G17 kts
Sea-level pressure: 30.06 ins. Hg: rising steadily
Visibility: 10 miles
3-hr Precip: TRACE
BHO SA 1455 E15 OVC 10 178/65/64/1812G17/ THN F ALQDS/ 8/6// 52003 6///

1 P.M.
Weather: Overcast Stratus (moderate rain shower beginning at 12:30 PM)
Temperature: 56F; Dew Point: 56F; Relative Humidity: 100%
Wind: N at 15G16 kts (wind shift at 12:25 PM via frontal passage)
Sea-level pressure: 30.03 ins. Hg: falling, then falling more slowly
Visibility: 2 miles, fog
6-hr Max temp: 69F
6-hr Min temp: 56F
6-hr Precip: 0.23 inches
BHO SA 1455 E10 OVC 2RF 170/56/56/3515G16/003/ RB30 WSHFT 25 FROPA/
8/6// 56008 60023 10069 20056

SUMMARY FOR THURSDAY, OCTOBER 15, 2020

TEMPERATURE (DEGREES F)
MAX…..71   NORMAL…..61
MIN…..50   NORMAL…..43
MEAN….61   NORMAL…..52

DEPARTURE FROM 30-YEAR NORMAL……………..+9
TOTAL DEPARTURE FOR THE MONTH…………….+36 [+2.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..4  DEPARTURE….. -9
TOTAL HEATING UNITS FOR THE MONTH…………123  DEPARTURE…..-41
TOTAL HEATING UNITS FOR THE SEASON………..221  DEPARTURE…..-85
TOTAL HEATING UNITS LAST SEASON TO DATE……252  DEPARTURE…..-31

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………. 0  DEPARTURE…… 0
TOTAL COOLING UNITS FOR THE MONTH…………. 1  DEPARTURE….. -4
TOTAL COOLING UNITS FOR THE SEASON………..831  DEPARTURE….+229
TOTAL COOLING UNITS LAST SEASON TO DATE……682  DEPARTURE….+149

PEAK WIND GUST FOR YESTERDAY (MPH)
420C/Official……………43 S   AT   2:59 P.M.
AEROVANE (south tower)……46 S   AT   2:58 P.M.
ASOS……………………43 S   AT   3:00 P.M.
DAVIS #1………………..45 S   AT   1:07 P.M.
DAVIS #2 (south tower)……48 S   AT   2:59 P.M.
RMY…………………… 42
MERLIN………………….43
FASTEST MILE FOR YESTERDAY…………………31 S   AT   2:59 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………30 S   AT   3:09 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…………..29 WSW AT   1:56 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE…………..35 S   AT   3:00 P.M.
AVERAGE WIND SPEED AND DIRECTION………….16.7 S [401 total miles] ASOS………………….17.0
DAVIS #1………………15.1 SSW [198 deg.] DAVIS #2………………18.0 S   [189 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE….-0.15
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.90  DEPARTURE….-0.32
ASOS…………..1.91
TOTAL PRECIPITATION FOR THE YEAR……….36.32  DEPARTURE….-4.98
ASOS………….37.12

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  TSTM
10/08  61/42/52/-2/0.00/…/..             41 W    AERO 41 W    RMY N/A
10/09  60/37/49/-5/0.00/…/..             25 SSW  AERO 28 SSW  RMY N/A
10/10  75/52/64/+10/0.00/…/..            40 SSW  AERO 40 SSW  RMY 38
10/11  64/47/56/+3/0.00/…/..             32 NNW  AERO 35 NNW  RMY N/A
10/12  52/48/50/-3/T/…/..                28 E    AERO 27 E    RMY N/A
10/13  57/49/53/0/1.74/…/..              32 E    AERO 33 E    RMY N/A
10/14  67/47/57/+5/0.00/…/..             23 WNW  AERO 25 WNW  RMY N/A
10/15  71/50/61/+9/0.00/…/..             43 S    AERO 46 S    RMY 42

10/16 The low since midnight is 60F, the daily normal low is 43F

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

RECORDS FOR OCTOBER 16
HIGH 86F IN 1897
LOW 28F IN 1886
PRECIP 2.82 INCHES IN 1974
SNOWFALL TRACE IN 2009
PEAK GUST 68e MPH SSE IN 1954 (HURRICANE HAZEL)

RECORDS FOR OCTOBER 17
HIGH 86F IN 1947
LOW 25F IN 1886
PRECIP 1.87 INCHES IN 1989
SNOWFALL TRACE IN 1970
PEAK GUST 61 MPH E IN 2019

TODAY’S REPORT PREPARED BY: Andrew Swanson