Sunday, September 6, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, SEPTEMBER 6, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

SPECTACULAR LATE SUMMER WEATHER TODAY…BRILLIANT SUNSHINE
WITH SEASONABLE TEMPERATURES AND LOW HUMIDITY…AUGUST
SUNSHINE WAS THE SECOND HIGHEST ON RECORD…

While dew points continue to remain low after the cold front that
Passed through the region a few days ago, temperatures have returned
To being above average with a high temperature of 87 degrees by the 1
O’clock observation.  This is more than 10 degrees above normal.

With the dry air, the visibility has been excellent today in
the 60-70 mile range.  Only a few thin cirrus to the West have
interrupted an almost completely clear sky.

BHO Warmest Augusts, deg F (1885-2015)

1) 72.6 in 2012
2) 72.5 in 1988
3) 72.4 in 2015
4) 72.3 in 2005
5) 72.1 in 2002

BHO Warmest August Average Maximum Temperature, deg F (1885-2015)

1) 83.2 in 2005
2) 83.1 in 1949
3) 82.6 in 2015
4) 82.5 in 1988
82.5 in 2002
82.5 in 2012

BHO Warmest August Average Minimum Temperature, deg F (1885-2015)

1) 64.9 in 2001
2) 64.6 in 2012
3) 64.4 in 2005
64.4 in 2015
5) 64.3 in 2003

BHO Slowest August Wind Speed, mph (1885-2015)

1) 9.5 in 1996
9.5 in 2008
3) 10.0 in 1899
10.0 in 2009
10.0 in 2012
10.0 in 2015

BHO Sunniest Augusts, hours (1886-2015)

1) 303.7 in 1971  (74%)
2) 303.2 in 2015  (73%)
3) 303.0 in 1969  (73%)
4) 298.1 in 1932  (72%)
5) 296.7 in 1970  (72%)

PRELIMINARY STATS FOR AUGUST 2015

TEMPERATURE, Deg. F
Avg. Max. 82.6 [+3.4] Avg. Min. 64.4 [+2.6] Mean      73.5 [+3.0] Corrected mean: 72.4
Max. for month: 92 on 18th
Min. for month: 58 on 8th, 10th, 28th

HEATING DEGREE DAYS (JUL-JUN)
Total heating units: 0 [-16] Total for the season: 1 [-24] Total for last season: 2

COOLING DEGREE DAYS (JAN-DEC)
Total cooling units: 272 [+86] Total for the season: 666 [+129] Total for last season: 479

PRECIPITATION, Inches
Total: 2.90 [-1.13] Greatest in 24 hrs: 1.24, 15th-16th

WIND, mph
Avg. uncorrected wind speed: 9.3
Avg. corrected wind speed: 10.0
Prevailing wind direction: WNW @ 15%
Peak gust and direction: 45 W on the 4th [TSTM GUST]

SUNSHINE: (corrected)
Campbell-Stokes card minutes: 18192 mins. of possible 24780 or 73%
Astronomical total minutes:   18916 mins. of possible 25773 or 73%
Long-term average for August is 58%

Today’s Observations:

7 A.M.
Weather: Clear, cloudless sky, light distant haze
Temperature: 63F; Dew Point: 56F; Wind: W at 8 kts,
Sea-level pressure: 30.22 ins. Hg, steady then rising
Visibility:  60 miles
6-hr Max temp: 63F
6-hr Min temp: 59F
24-hr precip: 0.00
BHO SA 1155 CLR 65 236/63/56/2708/022/ SKC LGT DSNT HZ/ 8/000
53004 10063 20059

10 A.M.
Weather: Clear, few altocumulus distant SW and ESE
Temperature: 78F; Dew Point 53F; Wind: VRB at 4 kts,
Wind: Light and Variable
Sea-level pressure: 30.21 ins. Hg, rising then falling
Visibility: 75 miles
BHO SA 1455 CLR 75 233/78/53/VRB04/021/ FEW AC DSNT SW AND ESE
WND LGT/ 8/040 58003

1 P.M.
Weather:  Clear, Few cirrus distant W-NNW
Temperature: 87F; Dew Point: 54F; Wind: W at 5 kts
Wing: Light
Sea-level pressure: 30.18 ins. Hg, falling then more slowly
Visibility: 60 miles
BHO SA 1755 CLR 60 222/87/54/2605/018/ FEW CI DSNT W-NNW
LGT DSNT HZ WND LGT/ 8/002 56011 10087 20063

SUMMARY FOR SATURDAY, SEPTEMBER 5, 2015

TEMPERATURE (DEGREES F)
MAX…..77   NORMAL…..75
MIN…..55   NORMAL…..58
MEAN….66   NORMAL…..67

DEPARTURE FROM 30-YEAR NORMAL……………………-1
TOTAL DEPARTURE FOR THE MONTH…………………..+20  [+5.1 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………1   DEPARTURE……….-2
TOTAL COOLING UNITS FOR THE MONTH…………..32   DEPARTURE………+14
TOTAL COOLING UNITS FOR THE SEASON…………698   DEPARTURE……..+143
TOTAL COOLING UNITS LAST SEASON TO DATE…….541   DIFFERENCE…….+157

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….16  SW AT 10:26 P.M.
ASOS……………………17 SSW AT 10:39 P.M.
DAVIS…………………..17 WSW AT 11:23 A.M. RMY 18
FASTEST MILE FOR YESTERDAY…………………24  NE AT  4:59 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………14  SW AT 11:18 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..13  SW AT 11:31 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..7.8 NNE
ASOS…………………..8.2
DAVIS………………….7.1 ENE [77 DEG]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE…..-0.12
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH……….Trace  DEPARTURE…..-0.58
ASOS……………0.00
TOTAL PRECIPITATION FOR THE YEAR………..30.26  DEPARTURE…..-5.34
ASOS…………….N/A ***
*** ASOS annual total not available due to erroneous readings

PRELIMINARY CLIMATE SUMMARY FOR AUGUST & SEPTEMBER CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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

8/1  88/68/78/+6/0.06/729/84               28 WNW RMY N/A
8/2  86/62/74/+2/0.00/865/100              24 SW  RMY N/A
8/3  89/68/79/+7/0.00/690/80               31 S   RMY N/A
8/4  86/66/76/+4/0.31/422/49               45 W   RMY 50  TSTM
8/5  84/64/74/+2/0.00/765/89               28 WNW RMY 27
8/6  80/59/70/-2/0.00/685/80               22 W   RMY 21
8/7  78/61/70/-2/0.00/845/99               20 ESE RMY 18
8/8  77/58/68/-4/0.00/741/87               18 E   RMY N/A
8/9  72/59/66/-6/T/458/54                  27 NNE RMY 26
8/10 84/58/71/0/0.00/830/98                28 S   RMY N/A
8/11 70/63/67/-4/0.52/000/00               32 SSE RMY 35
8/12 83/65/74/+3/0.00/766/91               22 W   RMY 20
8/13 83/62/73/+2/0.00/832/99               18 WNW RMY 18
8/14 86/63/75/+4/0.00/837/100              21 S   RMY 23
8/15 91/66/79/+8/1.24/534/64               38 W   RMY 41  TSTM
8/16 87/65/76/+5/T/774/93                  16 W   RMY N/A TSTM
8/17 90/70/80/+9/0.00/805/97               17 W   RMY 18
8/18 92/70/81/+10/0.27/546/66              31 W   RMY 32  TSTM
8/19 87/69/78/+8/0.00/775/94               23 S   RMY 24
8/20 85/70/78/+8/0.00/723/88               22 ESE RMY 22
8/21 82/69/76/+6/0.31/328/40               21 S   RMY 23
8/22 73/66/70/0/T/98/12                    18 ENE RMY 16
8/23 70/66/68/-2/0.18/000/00               20 ENE RMY 18
8/24 78/67/73/+3/0.01/122/15               18 SSW RMY 19
8/25 85/68/77/+8/0.00/526/65               22 S   RMY 22
8/26 82/64/73/+4/0.00/629/78               21 NW  RMY 22
8/27 79/59/69/0/0.00/779/97                22 W   RMY 23
8/28 80/58/69/0/0.00/753/94                15 NW  RMY 15
8/29 81/60/71/+2/0.00/766/96               21 WSW RMY 21
8/30 86/65/76/+8/0.00/588/74               23 W   RMY 23
8/31 87/68/78/+10/0.00/705/89              26 W   RMY 28

9/1  81/65/73/+5/0.00/…/..               20 SSW RMY 20
9/2  89/64/77/+9/0.00/…/..               20 SW  RMY 21
9/3  85/66/76/+9/trace/…/..              17 E   RMY N/A TSTM
9/4  72/58/65/0/0.00/…/..                31 ENE RMY N/A
9/5  77/55/66/-1/0.00/…/..               14 SW  RMY 18

9/6  low since midnight is 58F; normal low is now 58F

DAILY RECORDS FOR AUGUST 2015
None so far.

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

RECORDS FOR SEPTEMBER 6
HIGH 92F IN 1900
LOW 39F IN 1888
PRECIP 3.19 INCHES IN 1890
PEAK GUST 78e MPH SE IN 1979 (TROPICAL STORM DAVID)

RECORDS FOR SEPTEMBER 7
HIGH 92F IN 2007
LOW 40F IN 1888
PRECIP 2.95 INCHES IN 1891
PEAK GUST 58e MPH W IN 1941

TODAY’S REPORT PREPARED BY: Robert Millette