Monday, September 11, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, SEPTEMBER 11, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

HIGH PRESSURE RETURNS WITH WARM TEMPS AND SUNNY SKIES

Despite the chilly morning with a minimum temperature
of 50F, the day has become warmer than the previous few
days.  The max. temperature by 1:00PM was 76F which is
3F above normal.  The building high pressure has also
brought dry air keeping dew points in the upper 40s and
skies mostly sunny all day.  Few cirrus clouds have been
observed, and visibility has remained excellent at 70 miles.

Today’s Observations:

7 A.M.
Weather: Clear, few cirrus in all directions
Temperature: 53F; Dew Point: 45F; Wind: WNW at 10 kts
Sea-level pressure: 30.29 ins. Hg, rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 53F
6-hr Min temp: 50F
24-hr Precip:  0.00 in.
BHO SA 1155 CLR 70 257/53/45/3010/029/ FEW CI ALQDS/
8/001 53009 10053 20050

10 A.M.
Weather: Sky clear
Temperature: 68F; Dew Point: 50F; Wind: WNW at 7 kts
Sea-level pressure: 30.27 ins. Hg, falling steadily
Visibility: 70 miles
BHO SA 1455 CLR 70 251/68/50/3007/027/ SKC/ 57006

1 P.M.
Weather: Few cirrus SE-W
Temperature: 76F; Dew Point: 48F; Wind: WNW at 6 kts,
Wind speed: Light
Sea-level pressure: 30.19 ins. Hg, falling, then less quickly
Visibility: 70 miles
6-hr Max temp: 76F
6-hr Min temp: 53F
BHO SA 1755 CLR 70 225/76/48/2906/019/ FEW CI SE-W WND LGT/
8/001 56026 10076 20053

SUMMARY FOR SUNDAY, SEPTEMBER 10, 2017

TEMPERATURE (DEGREES F)
MAX…..71   NORMAL…..74
MIN…..51   NORMAL…..57
MEAN….61   NORMAL…..65

DEPARTURE FROM 30-YEAR NORMAL…………………….-4
TOTAL DEPARTURE FOR THE MONTH……………………-33 [-3.5 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE……….-3
TOTAL COOLING UNITS FOR THE MONTH…………..14   DEPARTURE………-18
TOTAL COOLING UNITS FOR THE SEASON…………621   DEPARTURE………+52
TOTAL COOLING UNITS LAST SEASON TO DATE…….839   DEPARTURE……..-218

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………4   DEPARTURE……….+2
TOTAL HEATING UNITS FOR THE MONTH…………..30   DEPARTURE………+13
TOTAL HEATING UNITS FOR THE SEASON………….56   DEPARTURE………+14
TOTAL HEATING UNITS LAST SEASON TO DATE……..11   DEPARTURE………+45

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….18 NW  AT  9:48 P.M.
AERO……………………16 NW  AT  9:45 P.M.
ASOS……………………19 NNW AT  9:48 P.M.
DAVIS…………………..22 N   AT  6:00 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………13 NW  AT  9:43 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………13 NW  AT 11:44 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..15 NNW AT  6:02 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..7.9 NNW
ASOS…………………..8.3
DAVIS………………….6.6 N [352 DEG.] 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……….1.52  DEPARTURE……+0.30
ASOS…………..1.55
TOTAL PRECIPITATION FOR THE YEAR……….37.88  DEPARTURE……+1.64
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings

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
M:    Missing data

9/1  68/47/58/-10/0.00/…/..              26 WNW AERO 28 WNW RMY 31
9/2  72/46/59/-9/0.00/…/..               18 NNW AERO 18 NNW RMY 21
9/3  63/52/58/-9/0.24/…/..               33 W   AERO 33 W   RMY 37
9/4  79/55/67/0/0.00/…/..                29 SSW AERO 28 SSW RMY N/A
9/5  84/62/73/+6/0.00/…/..               36 S   AERO 32 S   RMY 38
9/6  76/59/68/+1/…./…/..               28 S   AERO 28 S   RMY 30
9/7  74/58/66/0/…./…/..                24*WSW AERO 23 WSW RMY 24
9/8  74/53/64/-2/0.00/…/..               21 WSW AERO 18 WSW RMY 22
9/9  68/51/60/-5/T/…/..                  18 ENE AERO 16 ENE RMY 18
9/10 71/51/61/-4/0.00/…/..               18 NW  AERO 16 NW  RMY N/A

9/11 Low temp since midnight is 50F; normal low is now 56F

DAILY RECORDS FOR SEPTEMBER

9/1/17: DAILY RECORD LOW MINIMUM TEMPERATURE OF 47F,
TIES PREVIOUS RECORD SET IN 1975

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

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: Cecilia Borries-Strigle