Sunday, August 25, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, AUGUST 25, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

QUIET WEATHER CONTINUES

The recent stretch of nice summer weather has continued today.  After
another fairly cool morning, with a morning low temperature of 57F, the
temperature has climbed to over 80F by early afternoon.  The sky has been
mostly sunny once again today with a few cirrus clouds.  The air has been
dry again today, though not quite as dry as yesterday, with today’s dew
points mostly in the upper 40s to lower 50s.  Winds have been light and
variable, averaging about 5mph since 7AM this morning.  The barometric
pressure was high again today, with this morning’s sea level pressure
reading of 30.38 ins. Hg being the highest of the month so far.  Visibility
was slightly lower than yesterday, but still averaged about 70 miles throughout
the day.

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, we are likely to tie that streak.  Despite the recent dry
weather, the month is currently only a little under three quarters of an
inch below normal, largely due to the 2.21 inches of rain that fell 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 cirrus distant SW-W, thin smoke layer distant SE-WSW
Temperature: 61F; Dew Point: 52F; Wind: NNW at 8 kts
Sea-level pressure: 30.38 ins. Hg, rising then rising more slowly
Visibility: 70 miles, light distant haze
6-hr min. temp: 57F
BHO SA 1155 CLR 70 287/61/52/3308/038/ FEW CI DSNT SW-W
THN K LYR DSNT SE-WSW LGT DSNT HZ/ 8/001 51017 10061 20057

10 A.M.
Weather: Clear, few small cumulus and cumulus fractus distant S-NW, few
cirrus distant SW-WNW
Temperature: 75F; Dew Point: 54F; Wind: Estimated NNE at 3 kts,
Wind: Light and variable
Sea-level pressure: 30.38 ins. Hg, rising then falling
Visibility: 70 miles, light distant haze
BHO SA 1455 CLR 70 287/75/54/E0203/038/ FEW SML CU AND CUFRA DSNT S-NW
FEW CI DSNT SW-WNW LGT DSNT HZ WND LGT AND VRB/ 8/101 50000

1 P.M.
Weather: Thin scattered cirrus, few cumulus distant SE-S
Temperature: 79F; Dew Point: 50F; Wind: WSW at 7 kts,
Wind: Direction variable SSW-WNW
Sea-level pressure: 30.32 ins. Hg, falling then falling more slowly
Visibility: 70 miles, light distant haze
6-hr max. temp: 81F
BHO SA 1755 270 -SCT 70 268/79/50/2407/032/ FEW CU DSNT SE-S
LGT DSNT HZ WND 20V29/ 8/101 56019 10081 20061

WEATHER SUMMARY FOR SATURDAY, AUGUST 24, 2013

TEMPERATURE (DEGREES F)
MAX…..73     NORMAL…..78
MIN…..55     NORMAL…..61
MEAN….64     NORMAL…..70

DEPARTURE FROM 30-YEAR NORMAL…………………..-6
TOTAL DEPARTURE FOR THE MONTH………………….-34  [-1.6 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..0   DEPARTURE………-5
TOTAL COOLING UNITS FOR THE MONTH…………116   DEPARTURE……..-38
TOTAL COOLING UNITS FOR THE SEASON………..599   DEPARTURE……..+94
TOTAL COOLING UNITS LAST SEASON TO DATE……668   DIFFERENCE…….-69

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………….23 NNE  AT  12:54 A.M. *
AERO…………………22 NNE  AT  12:04 A.M.
ASOS…………………24 N    AT  12:55 A.M.
DAVIS………………..22 NNE  AT  1-2   A.M. RMY: N/A
FASTEST MILE FOR YESTERDAY………………16 NNE  AT  12:54 A.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………16 ENE  AT  10:23 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………..15 N    AT  12:42 A.M.
AVERAGE WIND SPEED AND DIRECTION………..9.5 NNE
ASOS………………..9.2
DAVIS……………….8.7 NE [47 deg.] * last of several occurrences…

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……….2.55   DEPARTURE…………-0.70
ASOS…………..2.60
TOTAL PRECIPITATION FOR THE YEAR……….37.84   DEPARTURE…………+3.60
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 73/55/64/-6/0.00/…/..         23 NNE AERO 22 MPH NNE RMY N/A

8/25 morning low temp: 57F; 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 25
HIGH 93F IN 1947, 1948, 2007
LOW 41F IN 1940
PRECIP 2.69 INCHES IN 2010
PEAK GUST 60e MPH SSW IN 1941

RECORDS FOR AUGUST 26
HIGH 96F IN 1900, 1948
LOW 46F IN 1885
PRECIP 5.85 INCHES IN 1924
PEAK GUST 55e MPH NNW IN 1947

TODAY’S REPORT PREPARED BY: Jonathan O’Brien