Wednesday, September 25, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 25, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

A FAIR EARLY FALL DAY ATOP GREAT BLUE HILL….

Today began clear with a visibility of 70 miles, increasing
to a max of 85 miles at the 10 A.M. observation. Skies became
cloudier as the day went on, being partly cloudy at 1 P.M.
The air remains dry, with dew points in the upper 40s. A cool
breeze has been coming in from the northwest at around 10 mph.

Very little has been measured for rainfall this month, with a
monthly total of only 1.02 inches. That is 2.15 inches below
normal at this point in the month.

The high so far today has been 71F, which is 3 degrees above
the normal high of 68F. The low since midnight was 50F,
which is a degree above our normal low of 51F.

Today’s Observations:

7 A.M.
Weather: Clear, few distant cumulus NW-SE
Temperature: 53F; Dew Point: 47F; Wind: W at 7 kts
Sea-level pressure: 29.88 ins. Hg, rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 54F
6-hr Min temp: 50F
24-hr Precip: 0.00 ins.
BHO SA 1155 CLR 70 117/53/47/2707/988/ FEW DSNT CU NW-SE/
8/100 51011 10054 20050

10 A.M.
Weather: Scattered cumulus
Temperature: 65F; Dew Point: 54F; Wind: W at 5 kts,
Wind: Light
Sea-level pressure: 29.89 ins. Hg, falling then rising
Visibility: 85 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 30 SCT 85 121/65/54/2905/989/ WND LGT/ 8/100
50004

1 P.M.
Weather: Broken cumulus and cirrus
Temperature: 69F; Dew Point: 47F; Wind: NW at 10 kts
Sea-level pressure: 29.85 ins. Hg, falling, then steady
Visibility: 80 miles
6-hr Max temp: 71F
6-hr Min temp: 53F
6-hr Precip: 0.00 ins.
BHO SA 1755 E40 BKN 250 BKN 80 108/69/47/3110/985/ 8/102 56013
10071 20053

SUMMARY FOR TUESDAY, SEPTEMBER 24, 2019

TEMPERATURE (DEGREES F)
MAX…..76   NORMAL…..69
MIN…..56   NORMAL…..52
MEAN….66   NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL…………………+6
TOTAL DEPARTURE FOR THE MONTH…………………+7 [+0.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON AUG TO JUL)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE………-6
TOTAL HEATING UNITS FOR THE MONTH…………..64   DEPARTURE……..-10
TOTAL HEATING UNITS FOR THE SEASON………….76   DEPARTURE……..-23
TOTAL HEATING UNITS LAST SEASON TO DATE……..56   DEPARTURE……..+20

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………1   DEPARTURE……….0
TOTAL COOLING UNITS FOR THE MONTH…………..54   DEPARTURE………-1
TOTAL COOLING UNITS FOR THE SEASON…………673   DEPARTURE……..+81
TOTAL COOLING UNITS LAST SEASON TO DATE…….855   DEPARTURE…….-182

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..26 W   AT  4:04 P.M.
AERO…………………….26 W   AT  2:52 P.M.
ASOS…………………….27 W   AT  4:03 P.M.
DAVIS……………………29 W   AT  4:01 P.M. RMY 27
FASTEST MILE FOR YESTERDAY………………….21 W   AT  3:08 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….20 W   AT  4:04 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………21 WSW AT  3:28 P.M.
AVERAGE WIND SPEED AND DIRECTION…………….11.0 W
ASOS…………………….11.1
DAVIS……………………11.4 W [273 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……….1.02  DEPARTURE……-2.15
ASOS…………..0.98
TOTAL PRECIPITATION FOR THE YEAR……….38.17  DEPARTURE……-0.03
ASOS………….38.02

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  The low since midnight is 50F, normal daily minimum is 51F

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

RECORDS FOR SEPTEMBER 25
HIGH 87F IN 1970
LOW 31F IN 1950
PRECIP 2.68 INCHES IN 1961
PEAK GUST 63 MPH SSW IN 1991

RECORDS FOR SEPTEMBER 26
HIGH 91F IN 2007
LOW 36F IN 1905,1922,1978
PRECIP 3.84 INCHES IN 1888
PEAK GUST 54e MPH S IN 1977

TODAY’S REPORT PREPARED BY: Benjamin Turner and Greg White