Sunday, September 11, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, SEPTEMBER 11, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

NEW RECORD FOR HIGHEST DAILY LOW SET AT 71 YESTERDAY

With a record high daily low added to the books, a warm start
ended with the passing of the cold front dropping temperatures
into the mid-60s.

The squall line that came through today didn’t have any thunder or
lightning, but it did produce wind gusts into the 40 MPH range
and bring a tenth of an inch of rain.

Conditions cleared quickly after the passage of the front, with
visibilities reaching 70 miles and temperatures rising back
into the upper 70s.

7 A.M.
Weather: Overcast Stratocumulus
Temperature: 73F; Dew Point: 69F; Wind: S at 19 kts
Sea-level pressure: 29.86 ins. Hg, rising then falling and lower
Visibility: 15 miles, hazy
6-hr Max temp: 74F
6-hr Min temp: 70F
24-hr precip: TRACE
BHO SA 1155 E15 OVC 15 111/73/69/1919G27/986/ HAZY/ 8/5//
58009 MANUAL 7000/ 10074 20070

10 A.M.
Weather: Overcast nimbostratus with light rain, Few Cumulus Fractus
Temperature: 66F; Dew Point: 66F; Wind: WNW at 10 kts,
Sea-level pressure: 29.91 ins. Hg, decreasing then increasing and higher
Visibility: 15 miles, except 10 miles E-SSE
BHO SA 1455 E18 OVC 15 129/66/66/3010G19/991/ R- FEW CU FRA HAZY
VSBY 10 E-SSE/ 53018 MANUAL 60010 ASOS 60007

1 P.M.
Weather: Scattered Altocumulus, Scattered Cirrus, Few Stratus ENE-SE
Temperature: 75F; Dew Point: 56F; Wind: W at 13 kts
Sea-level pressure: 29.93 ins. Hg, falling then rising and higher
Visibility: 80 miles
6-hr Max. temp: 75F
6-hr Min. temp: 66F
BHO SA 1755 10 SCT 20 SCT 80 134/75/56/2913G22/993/ FEW S ENE-SE
8/082 53005 MANUAL 60010 ASOS 60009 10075 20066

SUMMARY FOR SATURDAY, SEPTEMBER 10, 2016

TEMPERATURE (DEGREES F)
MAX…..82   NORMAL…..74
MIN…..71   NORMAL…..57
MEAN….77   NORMAL…..65

DEPARTURE FROM 30-YEAR NORMAL…………………..+12
TOTAL DEPARTURE FOR THE MONTH…………………..+30 [+2.1 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..12   DEPARTURE……….+9
TOTAL COOLING UNITS FOR THE MONTH…………..47   DEPARTURE………+15
TOTAL COOLING UNITS FOR THE SEASON…………839   DEPARTURE……..+268
TOTAL COOLING UNITS LAST SEASON TO DATE…….756   DIFFERENCE……..+75

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-2
TOTAL HEATING UNITS FOR THE MONTH……………0   DEPARTURE………-17
TOTAL HEATING UNITS FOR THE SEASON………….10   DEPARTURE………-32
TOTAL HEATING UNITS LAST SEASON TO DATE………9   DIFFERENCE………+7

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….25 S   AT  11:47 P.M.
AEROVANE………………..18 S   AT  11:47 P.M.
ASOS……………………27 S   AT  11:46 P.M.
DAVIS…………………..25 SSW AT  11:37 P.M. RMY 32
FASTEST MILE FOR YESTERDAY…………………18 S   AT  11:46 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………18 S   AT  11:47 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..17 S   AT  11:47 P.M.
AVERAGE WIND SPEED AND DIRECTION……………10.3 E
ASOS……………………10.8
DAVIS…………………..9.3 ESE [121 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……….1.21  DEPARTURE……+0.01
ASOS…………..1.22
TOTAL PRECIPITATION FOR THE YEAR……….26.18  DEPARTURE…..-10.06
ASOS………….26.49

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system 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

9/1  72/64/68/0/0.09/…/..                  21 NNW AERO 16 NNW RMY 20
9/2  76/58/67/-1/0.00/…/..                 23 ENE AERO 17 NE  RMY 23
9/3  71/56/64/-3/0.00/…/..                 16 E   AERO 12 E   RMY N/A
9/4  71/58/65/-2/0.00/…/..                 28 NE  AERO 21 NE  RMY 27
9/5  73/57/65/-2/0.52/…/..                 42 NNE AER0 33 NNE RMY 43
9/6  70/61/66/-1/0.54/…/..                 32 N   AERO 23 NNE RMY N/A
9/7  78/66/72/+6/0.05/…/..                 21 NE* AERO 15 NE* RMY 21
9/8  79/65/72/+6/T/…/..                    22 S   AERO 15 S   RMY 23
9/9  90/69/80/+14/T/…/..                   23 W   AERO 24 W   RMY 25
9/10 82/71/77/+12/T/…/..                   25 S   AERO 18 S   RMY 32

9/11 Low temp since midnight is 70F; normal low is now 56F

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

9/10/2016: RECORD High Minimum 71F, beats record of 69F set it 1989

RECORDS FOR SEPTEMBER 11
HIGH 93F IN 1983, 2013
LOW 37F IN 1917
PRECIP 5.23 INCHES IN 1954 (HURRICANE EDNA)
PEAK GUST 101 MPH NW IN 1954 (HURRICANE EDNA)

RECORDS FOR SEPTEMBER 12
HIGH 92F IN 1961
LOW 42F IN 1958,1967,1985
PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA)
PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA)

TODAY’S REPORT PREPARED BY: Robert Millette