Saturday, August 24, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, AUGUST 24, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

ANOTHER BEAUTIFUL SUMMER DAY

It has been another beautiful summer day today.  The temperature fell to
55F this morning, the coolest reading in over a week.  It has rebounded
into the low 70s this afternoon, which is below normal for today’s date.
In addition to these comfortable temperatures, the dew point has been very
low today, falling from around 50F this morning to just under 40F by early
afternoon, making the air feel very refreshing.  Dew points this low have
not been observed since late May!  The sky has been mostly sunny all day,
with only a few fair weather clouds.  Winds have been steady at about 10mph
out of the N-E today, with a few gusts over 20mph.  Visibility has been
good today, averaging about 75 miles.  Also of note today is the high
barometric pressure, as the sea level pressure this afternoon has risen to
30.33 ins. Hg, the highest reading of this month so far.

The dry stretch of weather continues, with no measurable precipitation
recorded on the summit since 0.02 inches of rain fell August 13.  This is
the longest such streak since we went 12 days without measurable
precipitation from April 26 through May 7 of this year.  With no rain
expected today or tomorrow, we are likely to tie that streak.  Despite the
recent dry weather, the month is currently only a little over half an inch
below normal, largely due to the 2.21 inches of rain on August 9.  That one
rain event accounts for about 87% of the monthly precipitation so far.

Today’s Observations:

7 A.M.
Weather: Clear, few altocumulus castellanus NE-SE, few cirrus NE-SE
Temperature: 61F; Dew Point: 50F; Wind: NE at 9 kts
Sea-level pressure: 30.29 ins. Hg, rising then rising more slowly
Visibility: 75 miles, light distant haze
6-hr min. temp: 55F
BHO SA 1155 CLR 75 256/61/50/0409/029/ FEW ACC NE-SE FEW CI NE-SE
LGT DSNT HZ/ 8/081 51024 10062 20055

10 A.M.
Weather: Clear, few small cumulus and cumulus fractus distant SE-SSE, few
altocumulus castellanus distant E-SE, few cirrus distant NE-SE
Temperature: 70F; Dew Point: 45F; Wind: ENE at 10G18 kts,
Wind: Direction variable NNE-E
Sea-level pressure: 30.32 ins. Hg, rising then rising more slowly
Visibility: 75 miles, light distant haze
BHO SA 1455 CLR 75 269/70/45/0610G18/032/ FEW SML CU AND CUFRA DSNT SE-SSE
FEW ACC DSNT E-SE FEW CI DSNT NE-SE LGT DSNT HZ WND 03V10/ 8/181 51013

1 P.M.
Weather: Clear, few cirrus and dense cirrus SW-NNW, dense cirrus distant
offshore ENE-E
Temperature: 70F; Dew Point: 39F; Wind: E at 10 kts,
Wind: Direction variable NE-ESE
Sea-level pressure: 30.33 ins. Hg, rising slightly
Visibility: 75 miles, light distant haze
6-hr max. temp: 72F
BHO SA 1755 CLR 75 271/70/39/0910/033/ FEW CI AND DNS CI SW-NNW
DNS CI DSNT OFFSHR ENE-E LGT DSNT HZ WND 05V12/ 8/001 53002 10072 20061

WEATHER SUMMARY FOR FRIDAY, AUGUST 23, 2013

TEMPERATURE (DEGREES F)
MAX…..78     NORMAL…..79
MIN…..63     NORMAL…..61
MEAN….70     NORMAL…..70

DEPARTURE FROM 30-YEAR NORMAL……………………0
TOTAL DEPARTURE FOR THE MONTH………………….-28  [-1.4 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..5   DEPARTURE……….0
TOTAL COOLING UNITS FOR THE MONTH…………116   DEPARTURE……..-33
TOTAL COOLING UNITS FOR THE SEASON………..599   DEPARTURE……..+99
TOTAL COOLING UNITS LAST SEASON TO DATE……660   DIFFERENCE…….-61

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………….25 NNW  AT  7:37 A.M.
AERO…………………25 NNW  AT  7:37 A.M. *
ASOS…………………26 NNW  AT  7:38 A.M.
DAVIS………………..22 NNW  AT  7:37 A.M. RMY: 24
FASTEST MILE FOR YESTERDAY………………18 NNW  AT  4:05 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………17 NW   AT  4:05 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………..15 NW   AT  4:04 A.M.
AVERAGE WIND SPEED AND DIRECTION………..9.1 NNW
ASOS………………..8.8
DAVIS……………….7.9 NNW [345 deg.] * last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M… 0.00   DEPARTURE…………-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.55   DEPARTURE…………-0.58
ASOS…………..2.60
TOTAL PRECIPITATION FOR THE YEAR……….37.84   DEPARTURE…………+3.72
ASOS…………..N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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  79/58/69/-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/-1/0.00/795/94         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 80/62/71/0/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/…/..         22 SW  AERO 22 MPH SSW RMY N/A
8/23 78/63/70/0/0.00/…/..          25 NNW AERO 25 MPH NNW RMY 24

8/24 morning low temp: 55F; the normal low is now 61F

DAILY RECORDS FOR AUGUST 2013
None so far.

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

RECORDS FOR AUGUST 24
HIGH 92F IN 1947
LOW 43F IN 1971
PRECIP 2.40 INCHES IN 2010
PEAK GUST 54 MPH W IN 1986

RECORDS FOR AUGUST 25
HIGH 93F IN 1947, 1948, 2007
LOW 41F IN 1940
PRECIP 2.69 INCHES IN 2010
PEAK GUST 60e MPH SSW IN 1941

TODAY’S REPORT PREPARED BY: Jonathan O’Brien