Friday, September 27, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, SEPTEMBER 27, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEAR AND GORGEOUS DAY FOLLOWING LAST
NIGHT’S RAINFALL….

We observed clear skies and an outstanding visibility
of 85 miles throughout the day. The air became dryer
as the day went on, with an afternoon humidity of 40%.
Rain last night left 0.25 inches in the gauge, measured
at the 7 A.M. observation. Wind has been relatively light
and westerly, with a max gust so far of 16 mph.

The high so far today has been 71F, which is 4 degrees above
the normal high of 67F. The low since midnight was 50F,
which is the same as our daily normal minimum.

Today’s Observations:

7 A.M.
Weather: Clear, few distant cirrus
Temperature: 52F; Dew Point: 51F; Wind: NW at 10 kts
Sea-level pressure: 30.09 ins. Hg, rising, then more
rapidly
Visibility: 85 miles
6-hr Max temp: 54F
6-hr Min temp: 50F
24-hr Precip: 0.00 ins.
BHO SA 1155 CLR 85 190/52/51/3110/009/ FEW DSNT CI ALQDS/
8/001 70025 51028 10054 20050

10 A.M.
Weather: Clear, few distant cirrus
Temperature: 56F; Dew Point: 52F; Wind: NW at 7 kts
Sea-level pressure: 30.16 ins. Hg, rising steadily
Visibility: 85 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 85 211/56/52/3307/016/ FEW DSNT CI ALQDS/
8/001 51021

1 P.M.
Weather: Clear, few distant cumulus
Temperature: 70F; Dew Point: 45F; Wind: WNW at 5 kts,
Wind: Light
Sea-level pressure: 30.14 ins. Hg, falling steadily
Visibility: 85 miles
6-hr Max temp: 71F
6-hr Min temp: 53F
6-hr Precip: 0.00 ins.
BHO SA 1755 CLR 85 204/70/45/2905/014/ FEW DSNT CU ALQDS
WND LGT/ 8/100 58007 10071 20053

SUMMARY FOR THURSDAY, SEPTEMBER 26, 2019

TEMPERATURE (DEGREES F)
MAX…..79   NORMAL…..68
MIN…..55   NORMAL…..51
MEAN….67   NORMAL…..59

DEPARTURE FROM 30-YEAR NORMAL…………………+8
TOTAL DEPARTURE FOR THE MONTH…………………+17 [+0.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE………-7
TOTAL HEATING UNITS FOR THE MONTH…………..67   DEPARTURE……..-20
TOTAL HEATING UNITS FOR THE SEASON………….79   DEPARTURE……..-33
TOTAL HEATING UNITS LAST SEASON TO DATE……..61   DEPARTURE……..+18

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………2   DEPARTURE………+1
TOTAL COOLING UNITS FOR THE MONTH…………..56   DEPARTURE………-1
TOTAL COOLING UNITS FOR THE SEASON…………678   DEPARTURE……..+84
TOTAL COOLING UNITS LAST SEASON TO DATE…….863   DEPARTURE…….-185

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..38 SW  AT  1:28 P.M.
AERO…………………….37 SW  AT  1:32 P.M.
ASOS…………………….38 SW  AT  1:28 P.M.
DAVIS……………………36 W   AT  4:26 P.M. RMY 39
FASTEST MILE FOR YESTERDAY………………….28 SW  AT  1:34 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….29 SW  AT  1:31 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………27 SSW AT  1:30 P.M.
AVERAGE WIND SPEED AND DIRECTION…………….12.3 S
ASOS…………………….12.6
DAVIS……………………12.0 SW [233 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.25  DEPARTURE……+0.10
ASOS…………..0.21
TOTAL PRECIPITATION FOR THE MONTH……….1.27  DEPARTURE……-2.20
ASOS…………..1.19
TOTAL PRECIPITATION FOR THE YEAR……….38.42  DEPARTURE……-0.20
ASOS………….38.23

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/-3/0.00/703/89                21 ENE AERO 14 ENE RMY 18
9/02  75/57/66/-2/0.37/165/21                39 W   AERO 41 W   RMY 41
9/03  77/61/69/+2/0.00/643/82                18 S   AERO 16 S   RMY N/A
9/04  83/61/72/+5/0.00/375/48                30 SW  AERO 28 SW  RMY 30
9/05  68/54/61/-6/0.00/513/66                23 NW  AERO 17 NW  RMY N/A
9/06  65/56/61/-6/0.03/054/07                37 ENE AERO 36 ENE RMY 36
9/07  70/51/61/-5/0.27/325/42                37 N   AERO 37 N   RMY N/A
9/08  73/53/63/-3/0.00/631/82                25 W   AERO 21 W   RMY N/A
9/09  71/54/63/-3/0.00/537/70                17 SE  AERO 16 SE  RMY 16
9/10  73/57/65/0/0.00/207/27                 25 S   AERO 25 S   RMY N/A
9/11  83/63/73/+8/0.00/419/55                31 SW  AERO 32 SW  RMY N/A
9/12  70/52/61/-4/0.11/015/02                29 ENE AERO 28 ENE RMY 28
9/13  65/49/57/-7/0.00/741/98                29 ENE AERO 27 ENE RMY 27
9/14  69/49/59/-5/0.19/030/04                36 S   AERO 37 S   RMY 37
9/15  78/62/70/+6/0.00/600/80                24 W   AERO 23 W   RMY 22
9/16  72/54/63/0/0.00/673/90                 25 WNW AERO 23 WNW RMY 25
9/17  67/49/58/-5/0.00/611/82                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  83/60/72/+11/0.00/…/..               21 WNW AERO 18 WNW RMY N/A
9/22  85/62/74/+13/0.00/…/..               24 SW  AERO 23 SW  RMY 25
9/23  88/65/77/+17/0.00/…/..               29 SSW AERO 28 SSW RMY 29
9/24  76/56/66/+6/0.04/…/..                26 W   AERO 26 W   RMY 27
9/25  73/50/62/+2/0.00/…/..                22 W   AERO 21 W   RMY 21
9/26  79/55/67/+8/0.25/…/..                38 SW  AERO 37 SW  RMY 39

9/27  The low since midnight is 50F, normal daily minimum is 50F

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

RECORDS FOR SEPTEMBER 27
HIGH 86F IN 2017
LOW 32F IN 1947
PRECIP 2.26 INCHES IN 1962
PEAK GUST 100 MPH SSE IN 1985 (HURRICANE GLORIA)

RECORDS FOR SEPTEMBER 28
HIGH 86F IN 2014
LOW 33F IN 1897,1947
PRECIP 2.46 INCHES IN 2004
PEAK GUST 69 MPH NE IN 1962

TODAY’S REPORT PREPARED BY: Benjamin Turner