Friday, September 8, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, SEPTEMBER 8, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

DRY AND CLEAR DAY ON TOP OF GREAT BLUE HILL

Low humidity today brought dry crisp air to Great Blue Hill.
The day started with a few cirrus and distant cumulus along
with a distant fog that quickly dissipated by 10:00 AM EST.
This allowed for visibility to reach 70 miles by 1:00 PM EST.
The afternoon brought scattered cumulus cloud. Winds have
been light to moderate and out of the WSW. Yesterday was a
seasonable day with a high and low temperature that did not
depart from a normal September 7th.

Today’s Observations:

7 A.M.
Weather: Sky Clear, few distant cumulus W-WNW, few cirrus E-S
Temperature: 56F; Dew Point: 51F; Wind: WSW at 6 kts,
Wind: Light
Sea-level pressure: 30.05 ins. Hg, rising, then more rapidly
Visibility: 60 miles distant fog in all directions
6-hr Max temp: 56F
6-hr Min temp: 53F
24-hr Precip:  Trace
BHO SA 1155 CLR 60 175/56/51/2506/005/ DSNT FG ALQDS FEW DSNT
CU W-WNW FEW CI E-S WND LGT/ 8/101 53016 10056 20053

10 A.M.
Weather: Sky Clear, few distant cumulus in all directions
few towering cumulus SSW, few cirrus S
Temperature: 67F; Dew Point: 49F; Wind: W at 8 kts
Sea-level pressure: 30.07 ins. Hg, rising, then more slowly
Visibility: 65 miles
BHO SA 1455 CLR 65 183/67/49/2608/007/ FEW DSNT CU ALQDS
FEW TCU SSW FEW CI S/ 8/201 50008

1 P.M.
Weather: Scattered cumulus
Temperature: 70F; Dew Point: 48F; Wind: WSW at 10G17 kts
Sea-level pressure: 30.06 ins. Hg, falling, then more slowly
Visibility: 70 miles
6-hr Max temp: 72F
6-hr Min temp: 56F
6-hour Precip: 0.00 inches
BHO SA 1755 45 SCT 70 180/70/48/2410G17/006/ 8/100 56003
10072 20056

SUMMARY FOR THURSDAY, SEPTEMBER 7, 2017

TEMPERATURE (DEGREES F)
MAX…..74   NORMAL…..74
MIN…..58   NORMAL…..58
MEAN….66   NORMAL…..66

DEPARTURE FROM 30-YEAR NORMAL……………………..0
TOTAL DEPARTURE FOR THE MONTH……………………-21 [-3.2 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………1   DEPARTURE……….-2
TOTAL COOLING UNITS FOR THE MONTH…………..14   DEPARTURE………-10
TOTAL COOLING UNITS FOR THE SEASON…………621   DEPARTURE………+60
TOTAL COOLING UNITS LAST SEASON TO DATE…….805   DEPARTURE……..-184

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-2
TOTAL HEATING UNITS FOR THE MONTH…………..20   DEPARTURE………+10
TOTAL HEATING UNITS FOR THE SEASON………….46   DEPARTURE………+11
TOTAL HEATING UNITS LAST SEASON TO DATE……..11   DEPARTURE………+35

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….24  S  AT  1:15 P.M.
AERO……………………23 WSW AT  3:52 A.M.
ASOS……………………25  W  AT  1:40 P.M.
DAVIS…………………..24 WSW AT  1:09 P.M. RMY 24
FASTEST MILE FOR YESTERDAY…………………16 WSW AT  1:40 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………17  W  AT  1:41 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..16  W  AT  1:09 P.M.
AVERAGE WIND SPEED AND DIRECTION………….10.7 WSW
ASOS………………….10.6
DAVIS………………….9.2  W [265 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……+0.68
ASOS…………..1.55
TOTAL PRECIPITATION FOR THE YEAR……….37.88  DEPARTURE……+2.02
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/SNOW/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  Low temp since midnight is 53F; normal low is now 58F

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 8
HIGH 97F IN 2015
LOW 42F IN 1978
PRECIP 1.51 INCHES IN 2011
PEAK GUST 45 MPH S IN 2012

RECORDS FOR SEPTEMBER 9
HIGH 92F IN 2015
LOW 41F IN 1938
PRECIP 1.97 INCHES IN 1969
PEAK GUST 52 MPH WNW IN 1969, NW IN 1978

TODAY’S REPORT PREPARED BY: Kaitlin Ann Geagan