Monday, September 30, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, SEPTEMBER 30, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

SEASONAL EARLY FALL DAY….

Fair weather has abounded since the start of morning observations.
With only scattered & passing clouds, light wind, and good amount of
sunshine, today has been very delightful. High pressure has remained
primarily steady throughout the day. Visibility has remained around
60 miles, which is a decrease from yesterday’s 80 mile average despite
today’s dry, fall air. The high temperature so far today is 62F,
which is 4 degrees below the normal maximum temperature of 66F. The
the low since midnight is 49F, which is our normal low for the day.

Today’s Observations:

7 A.M.
Weather: Scattered Stratocumulus; Scattered Altocumulus,
Few Cirrus distant SW through W
Temperature: 51F; Dew Point: 43F; Wind: NNE at 8 kts
Sea-level pressure: 30.39 ins. Hg, rising then rising more slowly
Visibility: 60 miles
6-hr Max temp: 53F
6-hr Min temp: 49F
24-hr Precip: 0.00 ins.
BHO SA 1155 40 SCT 140 SCT 60 290/51/43/0308/039/ FEW CI DSNT SW-W/
8/538 51006 10053 20049

10 A.M.
Weather: Broken Stratocumulus
Temperature: 59F; Dew Point: 44F; Wind: ENE at 8 kts, gusting to 15 kts
Sea-level pressure: 30.38 ins. Hg, Rising then falling
Visibility: 60 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E30 BKN 60 288/59/44/0608G15/038/ 8/500 50002

1 P.M.
Weather: Scattered Cumulus; Scattered Altocumulus
Temperature: 61F; Dew Point: 41F; Wind: E at 7 kts
Sea-level pressure: 30.35 ins. Hg, rising then falling
Visibility: 60 miles
6-hr Max temp: 62F
6-hr Min temp: 51F
6-hr Precip: 0.00 ins.
BHO SA 1755 30 SCT 130 SCT 60 278/61/41/0807/035/ WND 03V11/
8/130 58010 10062 20051

SUMMARY FOR SUNDAY, SEPTEMBER 29, 2019

TEMPERATURE (DEGREES F)
MAX…..75   NORMAL…..67
MIN…..53   NORMAL…..49
MEAN….64   NORMAL…..58

DEPARTURE FROM 30-YEAR NORMAL………………….+6
TOTAL DEPARTURE FOR THE MONTH…………………+34 [+1.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON AUG TO JUL)
TOTAL HEATING UNITS FOR YESTERDAY……………1   DEPARTURE………-7
TOTAL HEATING UNITS FOR THE MONTH…………..72   DEPARTURE……..-37
TOTAL HEATING UNITS FOR THE SEASON………….84   DEPARTURE……..-50
TOTAL HEATING UNITS LAST SEASON TO DATE……..80   DEPARTURE………+4

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE………-1
TOTAL COOLING UNITS FOR THE MONTH…………..58   DEPARTURE………-1
TOTAL COOLING UNITS FOR THE SEASON…………680   DEPARTURE……..+84
TOTAL COOLING UNITS LAST SEASON TO DATE…….863   DEPARTURE…….-183

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..24 NW  AT 8:36 A.M.
AERO…………………….23 NW  AT 4:51 A.M.
ASOS…………………….23 NW  AT 7:29 P.M.
DAVIS……………………24 NW  AT 8:34 A.M. RMY 23
FASTEST MILE FOR YESTERDAY………………….16 NW  AT 8:39 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 NNW AT 7:29 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………24 NW  AT 8:34 A.M.
AVERAGE WIND SPEED AND DIRECTION…………….9.8 NNW
ASOS…………………….10.1 NNW
DAVIS……………………10.2 NNW [346 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……….1.27  DEPARTURE……-2.64
ASOS…………..1.19
TOTAL PRECIPITATION FOR THE YEAR……….38.42  DEPARTURE……-0.52
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  72/50/61/+2/0.00/…/..                23 S   AERO 23 S   RMY 22
9/28  78/55/67/+9/0.00/…/..                31 S   AERO 29 S   RMY 30
9/29  75/53/64/+6/0.00/…/..                24 NW  AERO 23 NW  RMY 23

9/30  The low since midnight is 49F, normal daily minimum is 49F

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

RECORDS FOR SEPTEMBER 30
HIGH 84F IN 1986
LOW 31F IN 1992
PRECIP 2.44 INCHES IN 2015
PEAK GUST 58 MPH SSE IN 1999

RECORDS FOR OCTOBER 1
HIGH 85F IN 1927
LOW 30F IN 1992
PRECIP 1.63 INCHES IN 2014
PEAK GUST 68e MPH SSE IN 1977

TODAY’S REPORT PREPARED BY: Andrew Swanson & Matt Douglas