Friday, September 4, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, SEPTEMBER 4, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

COLD FRONT PASSES EARLY THIS MORNING FROM THE NORTH
THUNDERSTORM (WEAK) BROUGHT A SCANT TRACE OF RAIN EARLY TODAY
TEMPERATURES COOLED FROM 71F AT MIDNIGHT TO LOW OF 63 THIS MORNING

The passage of weak thunderstorms in the vicinity early today preceded
the passage of a cold front. Only a few drops of rain fell around
midnight last night.
After a second day with high temperatures in the mid to upper 80’s
a cooling breeze from the ENE gusting over 20 MPH is holding our
our temperature to the upper 60’s early this afternoon.

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) 303.0 in 1969  (73%)
3) 299.1 in 2015  (72%)
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

COOLING DEGREE DAYS
Total cooling units: 272 [+86] Total for the season: 537 [+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: 39 W on the 4th [TSTM GUST]

SUNSHINE:
Campbell-Stokes card minutes: 17946 mins. of possible 24780 or 72%
Astronomical total minutes:   18654 mins. of possible 25773 or 72%
Long-term average for August is 58%

Today’s Observations:

7 A.M.
Weather: Overcast stratus/stratocumulus
Temperature: 64F; Dew Point: 56F; Wind: NE at 14G20 8 kts,
Wind: Peak wind was 27 kts NE at 15 past the hour
Sea-level pressure: 30.12 ins. Hg, rising then more slowly
Visibility:  55 miles, light distant haze, except 25 miles SSE-S hazy
6-hr Max temp: 71F
6-hr Min temp: 63F
24-hr precip: trace
BHO SA 1155 E16 OVC 55 200/64/56/0514G20/012/ NMRS BRGHT SPTS
AND SML BINOVC VSBY SSE-S 25 HAZY LGT DSNT HZ PK WND 0427/15/
8/6// 51035 10071 20063

10 A.M.
Weather: Scattered stratocumulus lenticularis, overcast
of stratocumulus with bright spots and few small breaks
in the overcast
Temperature: 67F; Dew Point 55F; Wind: NE at 6 kts,
Wind: Gust 22 kts past hour
Sea-level pressure: 30.18 ins. Hg, rising then more rapidly
Visibility: 55 miles, light distant haze
BHO SA 1455 25 SCT E36 OVC 60 219/67/55/0512/018/ 25 SCT SCSL
NMRS BRGHT SPTS IOVC SML BINOVC VSBY LWR E-S HAZY DSNT LGT HZ W-N
WND GST 22 KTS PST HR/ 8/5// 53019

1 P.M.
Weather: Broken stratus/stratocumulus, overcast stratocumulus
Temperature: 67F; Dew Point: 59F; Wind: NE at 10 kts,
Wind: Direction NNE variable ENE
Sea-level pressure: 30.21 ins. Hg, rising then more slowly
Visibility: 15 miles, thin fog, hazy, NE-SE 12 miles,
WNW 20 miles
BHO SA 1755 E22 BKN 30 OVC 15 229/67/59/0511/021/
BRGHT SPTS AND BINOVC THN FH ALQDS VSBY NE-SE 12 WNW 20/
WND 01V07/ 8/5// 51010 10070 20064

SUMMARY FOR THURSDAY, SEPTEMBER 3, 2015

TEMPERATURE (DEGREES F)
MAX…..85   NORMAL…..76
MIN…..66   NORMAL…..59
MEAN….76   NORMAL…..67

DEPARTURE FROM 30-YEAR NORMAL……………………+9
TOTAL DEPARTURE FOR THE MONTH…………………..+23  [+7.5 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..11   DEPARTURE……….+7
TOTAL COOLING UNITS FOR THE MONTH…………..31   DEPARTURE………+20
TOTAL COOLING UNITS FOR THE SEASON…………697   DEPARTURE……..+149
TOTAL COOLING UNITS LAST SEASON TO DATE…….519   DIFFERENCE…….+178

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….17   E    AT   12:50 P.M.  *
ASOS……………………18   E    AT   12:01 P.M. .
DAVIS…………………..16   NE   AT   11:36 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………12  ENE   AT   12:30 P.M.  .
MAXIMUM 2-MINUTE ASOS AVERAGE………………13  ENE   AT   12:30 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..11   E    AT   12:30 P.M.
AVERAGE WIND SPEED AND DIRECTION……………6.8 ENE
ASOS………………….. 7.6
DAVIS…………………. 6.3  N [10 DEG]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..trace DEPARTURE…..-0.11
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..0.00  DEPARTURE…..-0.33
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE YEAR………..30.26  DEPARTURE…..-5.09
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 92/70/91/+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/+6/0.31/98/12                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/…/..               22 W   RMY 23
8/28 80/58/69/+0/0.00/753/94               15 NW  RMY 15
8/29 81/60/70/+2/0.00/734/92               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/T/…/..                  17 E   RMY N/A TSTM

9/4  low since midnight is 63F; normal low is now 59F

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 4
HIGH 90F IN 1953, 1973
LOW 46F IN 1987
PRECIP 3.22 INCHES IN 1922
PEAK GUST 47 MPH SE IN 1966

RECORDS FOR SEPTEMBER 5
HIGH 90F IN 1971
LOW 45F IN 1906
PRECIP 1.37 INCHES IN 1907
PEAK GUST 46 MPH NW IN 1994

TODAY’S REPORT PREPARED BY: Robert Skilling