Saturday, September 21, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, SEPTEMBER 21, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

LIGHT WINDS AND ABUNDANT SUNSHINE WITH
CLEAR SKIES….

Wind remained under 10 mph for the majority of the
day, out of the west. Skies have been clear at each
observation, despite some distant cumulus offshore
at the 10 A.M. Visibility was limited by haze, but
was 65 miles on average. Conditions were dry, with
the dew point holding in the low to mid 50’s.

The high so far today has been 82F. This is 12 degrees
above the normal maximum of 70F. The low since midnight
is 60F, 7 degrees above the normal of 53F.

Today’s Observations:

7 A.M.
Weather: Clear
Temperature: 64F; Dew Point: 56F; Wind: WNW at 8 kts
Sea-level pressure: 30.21 ins. Hg, rising steadily
Visibility: 70 miles
6-hr Max temp: 64F
6-hr Min temp: 60F
24-hr Precip: 0.00 ins.
BHO SA 1155 CLR 70 229/64/56/3308/021/ 53015 10064
20060

10 A.M.
Weather: Few distant cumulus offshore
Temperature: 76F; Dew Point: 55F; Wind: WNW at 4 kts,
Wind: Light and variable
Sea-level pressure: 30.23 ins. Hg, falling then rising
Visibility: 60 miles, distant haze
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 60 235/76/55/3304/023/ FEW DSNT CU
OFFSHR DST HZ ALQDS WND L/V/ 8/100 50006

1 P.M.
Weather: Clear
Temperature: 81F; Dew Point: 56F; Wind: WNW at 5 kts,
Wind: Light
Sea-level pressure: 30.27 ins. Hg, rising steadily
Visibility: 65 miles
6-hr Max temp: 82F
6-hr Min temp: 64F
6-hr Precip: 0.00 ins.
BHO SA 1755 CLR 65 248/81/56/3306/027/ WND LGT/ 58013
10082 20064

SUMMARY FOR FRIDAY, SEPTEMBER 20, 2019

TEMPERATURE (DEGREES F)
MAX…..78   NORMAL…..70
MIN…..50   NORMAL…..53
MEAN….64   NORMAL…..62

DEPARTURE FROM 30-YEAR NORMAL………………….+2
TOTAL DEPARTURE FOR THE MONTH…………………-40 [-2.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON AUG TO JUL)
TOTAL HEATING UNITS FOR YESTERDAY……………1   DEPARTURE………-4
TOTAL HEATING UNITS FOR THE MONTH…………..64   DEPARTURE……..+12
TOTAL HEATING UNITS FOR THE SEASON………….76   DEPARTURE………-1
TOTAL HEATING UNITS LAST SEASON TO DATE……..49   DEPARTURE……..+27

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE………-1
TOTAL COOLING UNITS FOR THE MONTH…………..25   DEPARTURE……..-26
TOTAL COOLING UNITS FOR THE SEASON…………644   DEPARTURE……..+56
TOTAL COOLING UNITS LAST SEASON TO DATE…….855   DEPARTURE…….-211

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..21 W   AT  8:33 P.M.
AERO…………………….18 W   AT  8:57 P.M.
ASOS…………………….20 W   AT  8:32 P.M.
DAVIS……………………19 W   AT  8:17 P.M. RMY 20
FASTEST MILE FOR YESTERDAY………………….15 W   AT  8:51 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….15 W   AT  8:47 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………16 W   AT  8:29 P.M.
AVERAGE WIND SPEED AND DIRECTION…………….8.4 W
ASOS…………………….8.9
DAVIS……………………9.0 W [280 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……….0.98  DEPARTURE……-1.60
ASOS…………..0.96
TOTAL PRECIPITATION FOR THE YEAR……….38.13  DEPARTURE……+0.52
ASOS………….37.99

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

9/01  73/56/65/-3/0.00/…/..                21 ENE AERO 14 ENE RMY 18
9/02  75/57/66/-2/0.37/…/..                39 W   AERO 41 W   RMY 41
9/03  77/61/69/+2/0.00/…/..                18 S   AERO 16 S   RMY N/A
9/04  83/61/72/+5/0.00/…/..                30 SW  AERO 28 SW  RMY 30
9/05  68/54/61/-6/0.00/…/..                23 NW  AERO 17 NW  RMY N/A
9/06  65/56/61/-6/0.03/…/..                37 ENE AERO 36 ENE RMY 36
9/07  70/51/61/-5/0.27/…/..                37 N   AERO 37 N   RMY N/A
9/08  73/53/63/-3/0.00/…/..                25 W   AERO 21 W   RMY N/A
9/09  71/54/63/-3/0.00/…/..                17 SE  AERO 16 SE  RMY 16
9/10  73/57/65/0/0.00/…/..                 25 S   AERO 25 S   RMY N/A
9/11  83/63/73/+8/0.00/…/..                31 SW  AERO 32 SW  RMY N/A
9/12  70/52/61/-4/0.11/…/..                29 ENE AERO 28 ENE RMY 28
9/13  65/49/57/-7/0.00/…/..                29 ENE AERO 27 ENE RMY 27
9/14  69/49/59/-5/0.19/…/..                36 S   AERO 37 S   RMY 37
9/15  78/62/70/+6/0.00/…/..                24 W   AERO 23 W   RMY 22
9/16  72/54/63/0/0.00/…/..                 25 WNW AERO 23 WNW RMY 25
9/17  67/49/58/-5/0.00/…/..                23 NW  AERO 23 N   RMY N/A
9/18  61/49/55/-7/0.00/…/..                26 NE  AERO 25 NE  RMY 25
9/19  67/43/55/-7/0.00/…/..                17 NE  AERO 18 NE  RMY N/A
9/20  78/50/64/+2/0.00/…/..                21 W   AERO 18 W   RMY 20

9/21  The low since midnight is 60F, normal daily minimum is 53F

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

RECORDS FOR SEPTEMBER 21
HIGH 91 IN 1895
LOW 35 IN 1929, 1956, 1962
PRECIP 5.58 INS IN 1961 (HURRICANE ESTHER; RETURNED AS TS SEPT 25-26TH)
PEAK GUST 186 MPH S IN 1938 (GREAT NEW ENGLAND HURRICANE; CALCULATED GUST, STATION RECORD)

RECORDS FOR SEPTEMBER 22
HIGH 90F IN 1895, 1914
LOW 30F IN 1904 (Earliest freeze)
PRECIP 1.16 INCHES IN 2001
PEAK GUST 60 MPH SSW IN 1989

TODAY’S REPORT PREPARED BY: Benjamin Turner