Wednesday, September 4, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 4, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

SUNNY AND DRIER

Yesterday we recorded a high temperature of 79F within the 10 o’clock hour
of the morning and dropping temps throughout the day. This would indicate
a cold front moved through. Since then we have had drier and cooler
air move in. It is now very comfortable compared to how humid it has been.
Within the first couple days of the month we have been recording dew points close
to 70 degrees. The dew point is now around 55F (at the time of report),
and the drier conditions are making for clear skies and visibility
around 70 miles!

AUGUST 2013 PRELIMINARY STATISTICS:
(departures relative to 1981-2010 average)

TEMPERATURE:
Average Max Temp: 78.5F [-0.7F] Average Min Temp: 60.7F [-1.1F] Mean Temp: 69.6F [-0.9F] 24-hr. Corr. Mean Temp: 68.8F [-0.6F] Max Temp: 87F on 21st
Min Temp: 53F on 15th

Total heating degree day units (month):    6  [-10] *NCDC method
Total heating degree day units (season):  12  [-13] *start July 1 (NCDC)
Total cooling degree day units (month):  157  [-29] *NCDC method
Total cooling degree day units (season): 640 [+103] *start Jan 1 (NCDC)

PRECIPITATION:
Total precipitation: 2.72 inches [-1.31 inches] Greatest 24-hr precipitation: 2.21 on 9th

WIND:
Avg wind speed: 9.8 MPH
Avg corrected wind speed: 10.3 MPH
Prevailing wind direction: W [16%] Peak gust: 37 MPH S on 9th
Peak fastest mile: 28 MPH SSW on 9th

SUNSHINE:
Astronomical minutes: 16,623 of a possible 25,727 or 65%
Campbell-Stokes sun card minutes: 16,086 of a possible 24,780 or 65%

METEOROLOGICAL SUMMER 2013 (JUNE, JULY, AUGUST) PRELIMINARY STATISTICS:
(departures relative to 1981-2010 average)

TEMPERATURE:
Average Max Temp: 79.4F [+1.1F] Average Min Temp: 61.9F [+1.3F] Mean Temp: 70.7F [+1.2F] 24-hr. Corr. Mean Temp: 69.8F [+1.3F] Max Temp: 95F on July 19th
Min Temp: 48F on June 4th

PRECIPITATION:
Total precipitation: 17.92 inches [+5.56 inches]

Blue Hill Warmest Summers (Jun-Aug), deg F:
1) 71.3 in 2010
2) 70.8 in 1949
3) 70.6 in 1999
4) 70.4 in 1952
5) 70.2 in 2005
6) 70.1 in 1994
7) 70.0 in 1973
70.0 in 2012
9) 69.9 in 1988
10) 69.8 in 2013

Blue Hill Warmest Jan-Aug, deg F:
1) 53.5 in 2012
2) 53.0 in 2010
3) 52.0 in 1991
4) 51.9 in 1949
51.9 in 1998
51.9 in 2002
7) 51.7 in 1999
8) 51.1 in 2006
9) 51.0 in 1973
51.0 in 2013

Blue Hill Wettest Summers (Jun-Aug), inches:
1) 25.22 in 1998
2) 24.61 in 1955
3) 24.09 in 1938
4) 21.56 in 2006
5) 21.02 in 1922
6) 20.23 in 1982
7) 18.71 in 1989
8) 17.92 in 2013
9) 17.42 in 1927
10) 17.20 in 1921

Today’s Observations:

7 A.M.
Weather: Clear,dense cirrus layer extending distance northeast through east
southeast through distance south.
Temperature: 61F; Dew Point: 58F; Wind: WNW at 9 kts.
Sea-level pressure: 29.90 ins. Hg, rising, then rising more rapidly
Visibility: 60 miles, except 70 miles NW, light distant haze
6-hr min. temp: 57F
BHO SA 1155 CLR 60 124/61/58/2909/990/ DNS CI LYR XTDNG DSNT NE-
E-SSE-DSNT S VSBY NW 70 LGT DSNT HZ/ 8/002 53016 10060 20057

10 A.M.
Weather:Clear, small cumulus fractus/cumulus forming, dense cirrus
layer distance northeast through east-southeast
Temperature: 72F; Dew Point: 57F; Wind: W at 11 kts,
Wind: Direction variable WSW-WNW
Sea-level pressure: 29.90 ins. Hg, steady
Visibility: 70 miles, light distant haze
BHO SA 1455 CLR 70 126/72/57/2811/990/ SML CUFRA/CU FRMG
DNS CI LYR DSNT ENE-ESE LGT DSNT HZ WND 24V30/ 8/102 50002

1 P.M.
Weather:Clear, few cumulus NW-NNW and distance SE-S
Temperature: 76F; Dew Point: 56F; Wind: WSW at 10 kts.
Wind: Direction WSW variable WNW
Sea-level pressure: 29.98 ins. Hg, falling slightly
Visibility: 75 miles, light distant haze
6-hr max. temp: 77F
BHO SA 1755 CLR 75 123/76/56/2510/989/ FEW SML CU DSNT NW-NNW AND
DSNT SE-S WND 24V30/ 8/100 58003 10077 20061

WEATHER SUMMARY FOR TUESDAY, SEPTEMBER 3, 2013

TEMPERATURE (DEGREES F)
MAX…..79     NORMAL…..76
MIN…..61     NORMAL…..59
MEAN….70     NORMAL…..67

DEPARTURE FROM 30-YEAR NORMAL…………………..+3
TOTAL DEPARTURE FOR THE MONTH………………….+12 [+3.8 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..5   DEPARTURE………+1
TOTAL COOLING UNITS FOR THE MONTH………….20   DEPARTURE………+9
TOTAL COOLING UNITS FOR THE SEASON………..660   DEPARTURE…….+112
TOTAL COOLING UNITS LAST SEASON TO DATE……722   DIFFERENCE…….-62

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………….28 S   AT  4:17 P.M
AERO…………………29 S   AT  4:17 P.M
ASOS…………………30 S   AT  4:17 P.M
DAVIS………………..27 SSW AT  4:17 P.M  RMY 30
FASTEST MILE FOR YESTERDAY………………22 S AT    4:18 P.M
MAXIMUM 2-MINUTE ASOS AVERAGE……………23 S AT    4:18 P.M
MAXIMUM 2-MINUTE DAVIS AVERAGE…………..22 S AT    4:18 P.M
AVERAGE WIND SPEED AND DIRECTION…………9.6 S
ASOS……………….9.6
DAVIS………………8.6 SW [232 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……….2.75   DEPARTURE………….+2.41
ASOS…………..2.88
TOTAL PRECIPITATION FOR THE YEAR……….40.76   DEPARTURE………….+5.40
ASOS…………..N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

PRELIMINARY CLIMATE SUMMARY FOR AUGUST & SEPTEMBER 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized

8/1  81/62/72/0/0.01/503/58          25 S   AERO 26 MPH S   RMY 27
8/2  81/62/72/0/0.23/518/60          26 W   AERO 26 MPH W   RMY 28
8/3  77/63/70/-2/T/276/32            22 WSW AERO 23 MPH WSW RMY 23
8/4  79/59/69/-3/T/645/75            25 WNW AERO 21 MPH WNW RMY 26
8/5  75/54/65/-7/0.00/858/100        26 WNW AERO 25 MPH WNW RMY 27
8/6  78/56/67/-5/0.00/846/99         17 ESE AERO 15 MPH S   RMY 16
8/7  80/59/70/-2/0.00/759/89         21 S   AERO 21 MPH S   RMY N/A
8/8  79/62/71/-1/0.08/153/18         25 S   AERO 25 MPH S   RMY N/A
8/9  73/70/72/0/2.21/000/00          37 S   AERO 39 MPH S   RMY 40
8/10 81/61/71/0/0.00/795/94          30 WNW AERO 31 MPH WNW RMY 31
8/11 78/58/68/-3/0.00/835/99         18 W   AERO 18 MPH W   RMY 21
8/12 81/62/72/+1/0.00/656/78         18 W   AERO 17 MPH WSW RMY 19
8/13 73/64/69/-2/0.02/193/23         16 SSE AERO 15 MPH SSE RMY N/A
8/14 73/57/65/-6/0.00/819/98         35 W   AERO 35 MPH W   RMY 35
8/15 75/53/64/-7/0.00/800/96         23 W   AERO 23 MPH W   RMY 24
8/16 77/57/67/-4/0.00/740/89         20 W   AERO 19 MPH W   RMY 21
8/17 77/59/68/-3/0.00/770/93         18 W   AERO 18 MPH W   RMY N/A
8/18 80/61/71/0/T/231/28             16 SSW AERO 17 MPH SSW RMY 18
8/19 82/58/70/0/T/494/60             17 W   AERO 18 MPH W   RMY 20
8/20 85/64/75/+5/0.00/772/94         17 NW  AERO 18 MPH NW  RMY N/A
8/21 87/65/76/+6/0.00/802/98         18 WSW AERO 18 MPH WSW RMY 18
8/22 84/67/76/+6/0.00/432/53         22 SW  AERO 22 MPH SSW RMY N/A  TSTM
8/23 78/63/71/+1/0.00/610/75         25 NNW AERO 25 MPH NNW RMY 24
8/24 73/55/64/-6/0.00/786/97         23 NNE AERO 22 MPH NNE RMY N/A
8/25 82/57/70/+1/0.00/791/98         20 SW  AERO 21 MPH SW  RMY 21
8/26 80/64/72/+3/T/145/18            26 WSW AERO 26 MPH SW  RMY 28
8/27 78/66/72/+3/0.07/329/41         16 NE  AERO 15 MPH NE  RMY 16
8/28 81/62/72/+3/T/631/79            26 NE  AERO 24 MPH NE  RMY 27
8/29 64/58/61/-8/0.05/000/00         23 NNE AERO 23 MPH NNE RMY 23
8/30 81/58/70/+2/0.00/429/54         17 WSW AERO 18 MPH WSW RMY 21
8/31 81/67/74/+6/0.05/005/01         21 SSW AERO 22 MPH S   RMY 23

9/1  76/67/72/+4/2.32/…/..         33 S   AERO 39 MPH S   RMY 38   TSTM
9/2  79/67/73/+5/0.43/…/..         30 SSE AERO 33 MPH SSE RMY N/A  TSTM
9/3  79/61/70/+3/0.00/…/..         28 S   AERO 29 MPH S   RMY 30

9/4  morning low temp: 57; the normal low is now 59F

DAILY RECORDS FOR AUGUST 2013
None.

DAILY RECORDS FOR SEPTEMBER 2013
9/1 – NEW DAILY RECORD MAXIMUM PRECIPITATION OF 2.32 INCHES;
surpasses previous record of 1.60 inches set in 1927

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 and Kevin Pecora