Sunday, August 18, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, AUGUST 18, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

MOSTLY CLOUDY AND SEASONABLE WITH VERY LIGHT WINDS TODAY

It has been a mostly cloudy day today on the summit, with several cloud layers
limiting sunshine.  The temperature has climbed to 80F so far this afternoon
after a morning low of 63F.  These levels are near the average for today’s
date, and August continues to run nearly 3 degrees below average for the month
so far.  The dew point has continued to run at or below 60F today, keeping the
air quite comfortable.  Winds have been very light today, with an average speed
of under 5mph since 7AM this morning and no gusts greater than 15mph.  Winds
were generally out of the  W-SW this morning, but turned more out of the S by
early afternoon.  The barometric pressure continues to run at high levels, and
yesterday evening’s reading of 30.31 inches is the highest of the month so far.
For the second straight day, the visibility has been limited to about 40 miles
for most of the day by haze.

Today’s Observations:

7 A.M.
Weather: Broken cirrostratus, broken cirrus, thin broken cirrus, few cumulus
and cumulus fractus NNW-NE, thin smoke layer along horizon WNW-N-SSE
Temperature: 68F; Dew Point: 57F; Wind: Estimated WNW at 4 kts,
Wind: Light
Sea-level pressure: 30.29 ins. Hg, steady then rising slightly
Visibility: 50 miles, distant haze
6-hr min. temp: 63F
BHO SA 1155 E200 BKN 250 BKN 300 –BKN 50 258/68/57/E2904/029/
FEW CU AND CUFRA NNW-NE DSNT HZ THN K LYR ALG HRZN WNW-N-SSE WND LGT/
8/106 53003 10068 20063

10 A.M.
Weather: Broken altocumulus, broken dense cirrus, broken cirrus, thin broken
cirrus, few cumulus and moderate cumulus WNW-NW, thin smoke layer along
horizon NNE-NE
Temperature: 72F; Dew Point: 60F; Wind: Estimated SW at 3 kts,
Wind: Light
Sea-level pressure: 30.29 ins. Hg, about steady
Visibility: 40 miles, distant haze
BHO SA 1455 E75 BKN 210 BKN 250 BKN 300 –BKN 40 256/72/60/E2203/029/
FEW CU AND MDT CU WNW-NW DSNT HZ THN K LYR ALG HRZN NNE-NE WND LGT/
8/258 55002

1 P.M.
Weather: Broken altocumulus, broken dense cirrus, broken cirrus, few cumulus
Temperature: 80F; Dew Point: 55F; Wind: S at 7 kts,
Wind: Direction variable SSE-WSW
Sea-level pressure: 30.24 ins. Hg, steady then falling
Visibility: 40 miles, distant haze
6-hr max. temp: 80F
BHO SA 1755 E75 BKN 210 BKN 250 BKN 40 241/80/55/1907/024/ FEW CU DSNT HZ
WND 15V24/ 8/158 58015 10080 20068

WEATHER SUMMARY FOR SATURDAY, AUGUST 17, 2013

TEMPERATURE (DEGREES F)
MAX…..77     NORMAL…..79
MIN…..59     NORMAL…..62
MEAN….68     NORMAL…..71

DEPARTURE FROM 30-YEAR NORMAL…………………..-3
TOTAL DEPARTURE FOR THE MONTH………………….-45  [-2.8 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY………….3    DEPARTURE………-3
TOTAL COOLING UNITS FOR THE MONTH…………68    DEPARTURE……..-47
TOTAL COOLING UNITS FOR THE SEASON……….551    DEPARTURE……..+85
TOTAL COOLING UNITS LAST SEASON TO DATE…..632    DIFFERENCE…….-81

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………….18 W  AT 1:27 A.M. *
AERO…………………18 W  AT 1:00 A.M. *
ASOS…………………20 W  AT 1:09 A.M.
DAVIS………………..18 W  AT N/A        RMY N/A
FASTEST MILE FOR YESTERDAY………………15 W  AT 1:28 A.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………14 W  AT 1:48 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………..N/A
AVERAGE WIND SPEED AND DIRECTION………..8.6 ENE
ASOS………………..8.2
DAVIS……………….7.9 ENE
* 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…………+0.19
ASOS…………..2.60
TOTAL PRECIPITATION FOR THE YEAR……….37.84   DEPARTURE…………+4.49
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/…/..         23 W   AERO 23 MPH W   RMY 24
8/16 77/57/67/-4/0.00/…/..         20 W   AERO 19 MPH W   RMY 21
8/17 77/59/68/-3/0.00/…/..         18 W   AERO 18 MPH W   RMY N/A

8/18 morning low temp: 63F; the normal low is now 62F

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 18
HIGH 93F IN 2002
LOW 47F IN 1824
PRECIP 5.75 INCHES IN 1955 [DIANE] PEAK GUST 46 MPH WNW IN 2007

RECORDS FOR AUGUST 19
HIGH 90F IN 1906, 1966, 2002
LOW 48F IN 1958
PRECIP 7.02 INCHES IN 1955 [DIANE – RECORD FOR MONTH] PEAK GUST 78 MPH ENE IN 1991 – HURRICANE BOB

TODAY’S REPORT PREPARED BY: Jonathan O’Brien