Saturday, October 13, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, OCTOBER 13, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

RAINY AND COOL WITH A LIGHT WESTERLY WIND….

We measured a total of 0.17 inches from today’s rain,
ending a little before the 1 P.M. observation. Visibility
was reduced to 10 miles this morning by a distant fog, but
increased to 45 miles following the end of the rain. Wind
has been light and westerly for most of the day, staying
at or below 10 mph on average. Temperatures have increased to
46F so far today. This is 15 degrees below the normal maximum
of 61F. The low since midnight is 43F, which is a degree lower
than the daily normal minimum of 44F.

PRELIMINARY STATS FOR SEPTEMBER 2018

TEMPERATURE, Deg. F
Avg. Max. 72.5 [+0.9] Avg. Min. 58.6 [+4.0] Mean 65.6 [+2.5] 24-hour corrected mean: 64.8
Max. for month: 92F on 3rd, 6th
Min. for month: 47F on 23rd

HEATING DEGREE DAYS
Total heating units: 87 [-30] Total for the season: 87 [-55] Total for last season: 93

COOLING DEGREE DAYS
Total cooling units: 110 [+50] Total for the season: 863 [+266] Total for last season: 707

PRECIPITATION, Inches
Total: 9.25 [+5.19] Greatest in 24 hrs: 3.32 ins. on the 18th-19th

WIND, mph
Avg. uncorrected wind speed: 9.4
Avg. corrected wind speed: 10.1
Prevailing wind direction: NE [12% of total hours] Peak gust and direction: 37 SSW

SUNSHINE:
Campbell-Stokes card minutes: 7608 minutes of possible 21582 or 35%
Astronomical total minutes: 7924 minutes of possible 22447 or 35%

BHO Lowest September Sunshine, hours (1886-2018):
1) 120.7 in 1934  [34%] 2) 126.8 in 2018  [35%] 3) 130.8 in 1889  [36%] 4) 131.1 in 1996  [36%] 5) 133.0 in 1907  [37%]

BHO Wettest Septembers, inches (1886-2018):
1) 12.37 in 1999
2) 11.04 in 1933
3) 10.23 in 1896
4) 10.00 in 1961
5) 9.62 in 1987
6) 9.58 in 1888
7) 9.36 in 1918
8) 9.25 in 2018
9) 8.81 in 1907
10) 8.78 in 1996

Today’s Observations:

7 A.M.
Weather: Light rain
Temperature: 45F; Dew Point: 44F; Wind: WNW at 5 kts,
Wind: Light
Sea-level pressure: 29.81 ins. Hg, rising steadily
Visibility: 10 miles, fog SSW-NE, except 30 miles
NE-SW
6-hr Max temp: 45F
6-hr Min temp: 44F
24-hr Precip: 0.13 ins.
BHO SA 1155 E120 OVC 10 094/45/42/2905/981/ FEW DSNT CU
NE-SW VSBY NE-SW 30 DSNT FG SSW-NE R-B55 WND LGT/ 8/12/
70013 53020 10045 20044

10 A.M.
Weather: Overcast stratus, few stratus fractus in
all directions
Temperature: 45F; Dew Point: 44F; Wind: W at 8G17 kts
Sea-level pressure: 29.84 ins. Hg, rising steadily
Visibility: 10 miles, distant fog in all directions
3-hr Precip: 0.09 ins.
BHO SA 1455 E40 OVC 10 104/45/44/2808G17/984/ FEW STFA
ALQDS DSNT FG ALQDS R-CTD/ 8/6// 6009/ 53010

1 P.M.
Weather: Overcast altostratus with light rain ending
Temperature: 46F; Dew Point: 45F; Wind: W at 8G15 kts
Sea-level pressure: 29.84 ins. Hg, falling steadily
Visibility: 45 miles
6-hr Max temp: 46F
6-hr Min temp: 43F
6-hr Precip: 0.17 ins.
BHO SA 1755 E70 OVC 45 103/46/45/2708G15/984/ R-EUKN/ 8/01/
6017/ 58001 10046 20043

SUMMARY FOR FRIDAY, OCTOBER 12, 2018

TEMPERATURE (DEGREES F)
MAX…..59   NORMAL…..62
MIN…..44   NORMAL…..45
MEAN….52   NORMAL…..53

DEPARTURE FROM 30-YEAR NORMAL…………………..-1
TOTAL DEPARTURE FOR THE MONTH…………………..64 [+5.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..13   DEPARTURE………+1
TOTAL HEATING UNITS FOR THE MONTH…………..67   DEPARTURE……..-58
TOTAL HEATING UNITS FOR THE SEASON…………154   DEPARTURE…….-113
TOTAL HEATING UNITS LAST SEASON TO DATE…….136   DIFFERENCE…….+18

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0  DEPARTURE………..0
TOTAL COOLING UNITS FOR THE MONTH…………..11  DEPARTURE……….+7
TOTAL COOLING UNITS FOR THE SEASON…………874  DEPARTURE……..+273
TOTAL COOLING UNITS LAST SEASON TO DATE…….727  DIFFERENCE…….+147

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..32 NW  AT 1:28  P.M.
AERO…………………….32 NW  AT 1:42  P.M.
ASOS…………………….34 NW  AT 1:30  P.M.
DAVIS……………………32 NNW AT 1:18  P.M. RMY 33
FASTEST MILE FOR YESTERDAY………………….23 NW  AT 1:42  P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….22 NW  AT 1:42  P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………24 NW  AT 1:30  P.M.
AVERAGE WIND SPEED AND DIRECTION…………..11.5 NNW
ASOS…………………..11.1
DAVIS………………….11.1 NW [326 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.13  DEPARTURE……-0.02
ASOS…………..0.14
TOTAL PRECIPITATION FOR THE MONTH……….2.49  DEPARTURE……+0.71
ASOS…………..2.49
TOTAL PRECIPITATION FOR THE YEAR……….49.57  DEPARTURE……+8.89
ASOS………….51.41

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 75/58/67/-1/0.00/521/66        17 NE  AERO 15 NE  RMY 16
9/02 83/61/72/+4/0.00/684/87        20 SSW AERO 18 SSW RMY N/A
9/03 92/68/80/+13/0.00/650/83       24 WSW AERO 22 WSW RMY 25
9/04 88/70/79/+12/0.00/695/89       17 W   AERO 16 W   RMY 17
9/05 89/67/78/+11/0.00/638/82       23 SSW AERO 23 SSW RMY 25
9/06 92/70/81/+14/0.56/488/63       29 NNW AERO 29 NNW RMY N/A TSTM
9/07 70/63/67/+1/0.01/000/00        24 NE  AERO 22 NE  RMY N/A
9/08 68/54/61/-5/0.00/031/04        22 NE  AERO 18 NE  RMY 21
9/09 61/53/57/-9/0.00/000/00        23 NE  AERO 21 NE  RMY N/A
9/10 62/56/59/-6/…./000/00        30 E   AERO 28 E   RMY 28
9/11 75/61/68/+3/…./000/00        23 E   AERO 21 E   RMY N/A TSTM
9/12 69/63/66/+1/…./000/00        21 ENE AERO 21 ENE RMY 21  TSTM
9/13 68/62/65/+1/…./091/12        21 NE  AERO 21 NE  RMY N/A TSTM
9/14 75/61/68/+4/…./233/31        13 NE  AERO 12 ENE RMY 12
9/15 76/62/69/+5/0.01/218/29        14 SW  AERO 13 SW  RMY 13
9/16 84/61/73/+10/…./695/93       15 S   AERO 14 S   RMY N/A
9/17 82/64/73/+10/…./372/50       22 SSW AERO 22 SSW RMY N/A
9/18 74/67/71/+9/…./000/00        31 SSW AERO 30 SSW RMY N/A TSTM
9/19 66/57/62/0/…./007/01         28 NE  AERO 25 NE  RMY 26
9/20 63/55/59/-3/…./110/15        22 NE  AERO 21 NE  RMY 19
9/21 70/55/63/+2/…./352/48        37 SSW AERO 37 SSW RMY 41
9/22 70/51/61/0/…./175/24         37 SW  AERO 36 SW  RMY 30
9/23 60/47/54/-6/…./058/08        14 N   AERO 13 N   RMY N/A
9/24 55/50/53/-7/…./000/00        37 ENE AERO 35 ENE RMY 35
9/25 68/51/60/0/…./000/00         36 SE  AERO 37 SE  RMY 38
9/26 79/66/73/+14/…./244/34       35 SSW AERO 37 SSW RMY 37
9/27 66/56/61/+2/…./465/65        26 NNE AERO 25 NNE RMY 28
9/28 56/52/54/-4/…./029/04        24 NNE AERO 21 NNE RMY 23
9/29 71/50/61/+3/…./518/73        20 NW  AERO 18 NW  RMY 20
9/30 68/48/58/0/…./650/92         20 W   AERO 16 W   RMY N/A

DAILY RECORDS FOR SEPTEMBER

09/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 70F,
BREAKS PREVIOUS RECORD OF 68F SET IN 1937 AND 1959

09/06/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 92F,
TIES PREVIOUS RECORD OF 92F SET IN 1900

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 65/53/59/+2/…./…/..         21 ENE AERO 18 SSW RMY N/A
10/02 64/53/59/+2/…./…/..         33 S   AERO 32 S   RMY 35 TSTM
10/03 60/52/56/0/…./…/..          18 NNE AERO 14 NNE RMY 14
10/04 69/57/63/+7/…./…/..         29 SSW AERO 29 SSW RMY 32
10/05 64/47/56/0/…./…/..          25 NE  AERO 21 NE  RMY 24
10/06 64/45/55/0/0.00/…/..          23 SSW AERO 23 SSW RMY 25
10/07 75/56/66/+11/…./…/..        28 NE  AERO 24 ENE RMY 27
10/08 56/53/55/+1/…./…/..         22 ENE AERO 20 ENE RMY N/A
10/09 75/56/66/+12/…./…/..        26 WSW AERO 28 SW  RMY 29
10/10 82/65/74/+20/…./…/..        24 WSW AERO 23 WSW RMY 25
10/11 70/56/63/+10/…./…/..        48 NNE AERO 47 NNE RMY 50
10/12 59/44/52/-1/…./…/..         32 NW  AERO 32 NW  RMY 33

10/13 Low temp since midnight is 44F; normal low is 44F

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

RECORDS FOR OCTOBER 13
HIGH 84F IN 1930,1954
LOW 29F IN 2012
PRECIP 5.92 INCHES IN 1895
SNOWFALL 4.2 INCHES IN 1934
PEAK GUST 46e MPH W IN 1950

RECORDS FOR OCTOBER 14
HIGH 79F IN 2000
LOW 28F IN 1958
PRECIP 2.69 INCHES IN 1990
SNOWFALL 2.0 INCHES IN 1913
PEAK GUST 63e W IN 1976

TODAY’S REPORT PREPARED BY: Benjamin Turner