Saturday, October 5, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, OCTOBER 5, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEAR WITH PERFECT VISIBILITY AFTER A COOLER THAN
NORMAL MORNING….

We observed a perfect visibility of 90 miles since
10 A.M. Sky conditions have been mostly clear, with
some very distant cumulus being seen to the east.
Wind is light an northerly, making for perfect
viewing from the top of the tower.

Despite abundant sunshine, temperatures have stayed cool
due to a cool air mass from the north entering the region
overnight. The high so far today is 57F, which
is 4 degrees below the normal high of 64F. The low this
morning was 35F, which is 12 degrees below the daily normal
minimum of 47F.

PRELIMINARY STATS FOR SEPTEMBER 2019

TEMPERATURE, Deg. F
Avg. Max. 73.6 [+2.0] Avg. Min. 54.5 [-0.1] Mean      64.1 [+1.0] 24-hour corrected mean: 63.4
Max. for month: 88F on the 23rd
Min. for month: 43F on the 19th

HEATING DEGREE DAYS
Total heating units:    81 [-36] Total for the season:   93 [-49] Total for last season:  87

COOLING DEGREE DAYS
Total cooling units:    58  [-2] Total for the season:  680 [+83] Total for last season: 863

PRECIPITATION, Inches
Total: 1.27 [-2.79] Greatest in 24 hrs: N/A

WIND, mph
Avg. uncorrected wind speed: 10.3 mph
Avg. corrected wind speed:   10.9 mph
Prevailing wind direction:   SSW [11%] Peak gust and direction:     39 W on the 2nd

SUNSHINE:
Campbell-Stokes card minutes: N/A
Astronomical total minutes:   N/A

Today’s Observations:

7 A.M.
Weather: Clear, few distant cumulus offshore
Temperature: 37F; Dew Point: 30F; Wind: NW at 8 kts
Sea-level pressure: 30.44 ins. Hg, falling then rising
Visibility: 85 miles
6-hr Max temp: 39F
6-hr Min temp: 35F
24-hr Precip: 0.00 ins.
BHO SA 1155 CLR 85 307/37/30/3308/044/ FEW DSNT CU OFFSHR/
8/100 53016 10039 20035

10 A.M.
Weather: Clear, few distant cumulus offshore
Temperature: 50F; Dew Point: 30F; Wind: N at 4 kts,
Wind: Light and variable
Sea-level pressure: 30.47 ins. Hg, rising steadily
Visibility: 90 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 90 315/50/30/0104/047/ FEW DSNT CU OFFSHR
WND L/V/ 8/100 51008

1 P.M.
Weather: Clear, few distant cumulus E-S
Temperature: 55F; Dew Point: 27F; Wind: NW at 4 kts,
Wind: Light and variable
Sea-level pressure: 30.43 ins. Hg, falling steadily
Visibility: 90 miles
6-hr Max temp: 57F
6-hr Min temp: 37F
6-hr Precip: 0.00 ins.
BHO SA 1755 CLR 90 304/55/27/3304/043/ FEW DSNT CU E-S
WND L/V/ 8/100 57011 10057 20037

SUMMARY FOR FRIDAY, OCTOBER 4, 2019

TEMPERATURE (DEGREES F)
MAX…..59   NORMAL…..65
MIN…..40   NORMAL…..47
MEAN….50   NORMAL…..56

DEPARTURE FROM 30-YEAR NORMAL………………….-6
TOTAL DEPARTURE FOR THE MONTH………………….-5 [-1.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..15   DEPARTURE………+6
TOTAL HEATING UNITS FOR THE MONTH…………..39   DEPARTURE………+3
TOTAL HEATING UNITS FOR THE SEASON…………132   DEPARTURE……..-46
TOTAL HEATING UNITS LAST SEASON TO DATE…….110   DEPARTURE……..+22

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE………-1
TOTAL COOLING UNITS FOR THE MONTH……………0   DEPARTURE………-2
TOTAL COOLING UNITS FOR THE SEASON…………680   DEPARTURE……..+81
TOTAL COOLING UNITS LAST SEASON TO DATE…….863   DEPARTURE…….-183

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..38 NNW  AT 10:47 A.M.
AERO…………………….38 NNW  AT 10:44 A.M.
ASOS…………………….38 NW   AT  9:30 A.M.
DAVIS……………………37 NW   AT  9:28 A.M. RMY 38
FASTEST MILE FOR YESTERDAY………………….28 NNW  AT  9:18 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….25 NW   AT  9:30 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………26 NW   AT  9:17 A.M.
AVERAGE WIND SPEED AND DIRECTION……………11.8 NNW
ASOS……………………11.4
DAVIS…………………..11.9 NW [331 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……….0.59  DEPARTURE……-0.01
ASOS…………..0.58
TOTAL PRECIPITATION FOR THE YEAR……….39.01  DEPARTURE……-0.68
ASOS………….38.81

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/T/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/-7/0.00/579/78                26 NE  AERO 25 NE  RMY 25
9/19  67/43/55/-7/0.00/709/96                17 NE  AERO 18 NE  RMY N/A
9/20  78/50/64/+2/0.00/677/92                21 W   AERO 18 W   RMY 20
9/21  83/60/72/+11/0.00/711/97               21 WNW AERO 18 WNW RMY N/A
9/22  85/62/74/+13/0.00/687/94               24 SW  AERO 23 SW  RMY 25
9/23  88/65/77/+17/0.00/539/74               29 SSW AERO 28 SSW RMY 29
9/24  76/56/66/+6/0.04/616/85                26 W   AERO 26 W   RMY 27
9/25  73/50/62/+2/0.00/686/95                22 W   AERO 21 W   RMY 21
9/26  79/55/67/+8/0.25/388/54                38 SW  AERO 37 SW  RMY 39
9/27  72/50/61/+2/0.00/695/97                23 S   AERO 23 S   RMY 22
9/28  78/55/67/+9/0.00/664/93                31 S   AERO 29 S   RMY 30
9/29  75/53/64/+6/0.00/619/87                24 NW  AERO 23 NW  RMY 23
9/30  62/49/56/-2/0.00/609/86                23 NNE AERO 16 NNE 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  67/52/60/+3/0.06/…/..               28 SW  AERO 25 SSW RMY 29
10/02  74/49/62/+5/0.42/…/..               30 ENE AERO 25 ENE RMY 28
10/03  51/46/49/-7/…./…/..               28 ENE AERO 26 ENE RMY N/A
10/04  59/40/50/-6/…./…/..               38 NNW AERO 38 NNW RMY 38

10/05  The low since midnight is 35F, normal daily minimum is 47F

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

RECORDS FOR OCTOBER 5
HIGH 86F IN 2007
LOW 29F IN 1965
PRECIP 3.17 INCHES IN 1962
PEAK GUST 64e MPH S IN 1979

RECORDS FOR OCTOBER 6
HIGH 83F IN 1990, 2007
LOW 26F IN 1965
PRECIP 3.78 INCHES IN 1962
PEAK GUST 60e MPH S IN 1942

TODAY’S REPORT PREPARED BY: Benjamin Turner