Friday, September 15, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, SEPTEMBER 15, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPS AGAIN REACH INTO THE 80s,
TOWERING CUMULUS SPOTTED AT 1:00PM EST

Above normal temperatures continue today with a max. of
81F by 1:00PM.  The below normal temps. from the first
few days of the month have been balanced out by the 80+
temps. from the past four days.  The total temperature
departure for the month is now 0F through 1:00PM today.

Winds out of the south and south-southwest continue to
bring humid air into the region.  Dew points have measured
in the upper 60s today with moderate and towering cumulus
observed at the 1:00PM observation.  Scattered showers and
thunderstorms are forecast for this afternoon.

Today’s Observations:

7 A.M.
Weather: Fog, broken stratocumulus
Temperature: 68F; Dew Point: 68F; Wind: S at 6 kts,
Wind speed: Light
Sea-level pressure: 30.03 ins. Hg, rising unsteadily
Visibility: 3 miles, variable 5-8 miles NE-N
6-hr Max temp: 68F
6-hr Min temp: 67F
24-hr Precip:  Trace
BHO SA 1155 E64 BKN 3F 170/68/68/1806/003/ VSBY NE-N 5V8 WND LGT/
8/500 52019 10068 20067

10 A.M.
Weather: Broken cumulus, broken altocumulus
Temperature: 74F; Dew Point: 67F; Wind: SSW at 4 kts,
Wind speed: Light
Sea-level pressure: 30.08 ins. Hg, rising, then more slowly
Visibility: 10 miles, distant fog in all directions
BHO SA 1455 E9 BKN 80 BKN 10 187/74/67/2104/008/ DSNT FG ALQDS WND LGT/
8/180 51017

1 P.M.
Weather: Scattered moderate cumulus, towering cumulus W-E,
scattered altocumulus
Temperature: 81F; Dew Point: 65F; Wind: estimated SSW at 2 kts,
Wind: Light and variable
Sea-level pressure: 30.05 ins. Hg, falling unsteadily
Visibility: 40 miles, distant haze in all directions
6-hr Max temp: 81F
6-hr Min temp: 68F
BHO SA 1755 34 SCT 84 SCT 40 177/81/65/E2103/005/ TCU W-E DSNT HZ ALQDS
WND L/V/ 8/230 57010 10081 20068

SUMMARY FOR THURSDAY, SEPTEMBER 14, 2017

TEMPERATURE (DEGREES F)
MAX…..82   NORMAL…..72
MIN…..66   NORMAL…..55
MEAN….74   NORMAL…..64

DEPARTURE FROM 30-YEAR NORMAL……………………+10
TOTAL DEPARTURE FOR THE MONTH……………………-10 [-0.9 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………9   DEPARTURE……….+7
TOTAL COOLING UNITS FOR THE MONTH…………..36   DEPARTURE……….-5
TOTAL COOLING UNITS FOR THE SEASON…………643   DEPARTURE………+65
TOTAL COOLING UNITS LAST SEASON TO DATE…….855   DEPARTURE……..-212

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-3
TOTAL HEATING UNITS FOR THE MONTH…………..31   DEPARTURE……….+3
TOTAL HEATING UNITS FOR THE SEASON………….57   DEPARTURE……….+4
TOTAL HEATING UNITS LAST SEASON TO DATE……..11   DEPARTURE………+46

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….23 SW  AT  2:23 P.M.
AERO……………………23 WSW AT  2:20 P.M.
ASOS……………………24 WSW AT 11:52 A.M.
DAVIS…………………..28 SSW AT  1:40 P.M. RMY 25
FASTEST MILE FOR YESTERDAY…………………16 WSW AT 11:51 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………18 SW  AT  1:17 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..17 SW  AT  1:17 P.M.
AVERAGE WIND SPEED AND DIRECTION………….10.9 SW
ASOS………………….11.2
DAVIS………………….8.3 SW [225 DEG.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…Trace  DEPARTURE……-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.52  DEPARTURE……-0.23
ASOS…………..1.55
TOTAL PRECIPITATION FOR THE YEAR……….37.88  DEPARTURE……+1.11
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/-10/0.00/749/95              26 WNW AERO 28 WNW RMY 31
9/2  72/46/59/-9/0.00/542/69               18 NNW AERO 18 NNW RMY 21
9/3  63/52/58/-9/0.24/000/00               33 W   AERO 33 W   RMY 37
9/4  79/55/67/0/0.00/702/90                29 SSW AERO 28 SSW RMY N/A
9/5  84/62/73/+6/0.00/583/75               36 S   AERO 32 S   RMY 38
9/6  76/59/68/+1/0.49/070/09               28 S   AERO 28 S   RMY 30 TSTM
9/7  74/58/66/0/0.79/…/..                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 78/50/64/-1/0.00/…/..               20 NNW AERO 17 NNW RMY 20
9/12 84/58/71/+6/0.00/…/..               22 WSW AERO 18 WSW RMY 23
9/13 84/59/72/+8/T/…/..                  18 WSW AERO 15 WSW RMY 20 TSTM
9/14 82/66/74/+10/0.00/…/..              23 SW  AERO 23 WSW RMY 25 TSTM

9/15 Low temp since midnight is 68F; normal low is now 55F

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 15
HIGH 89F IN 1931
LOW 35F IN 1913
PRECIP 3.93 INCHES IN 1904 (Extra-tropical storm making landfall in
New England on 9/15/1904 passing east of BHO and bringing a storm total
of 4.11 inches 9/14-15/1904)
PEAK GUST 65e MPH NW, WSW IN 1944 (In the wake of Great Atlantic Hurricane)

RECORDS FOR SEPTEMBER 16
HIGH 91F IN 1939,1941
LOW 39F IN 1984
PRECIP 5.12 INCHES IN 1933 (Hurricane)
PEAK GUST 59 MPH SSE IN 1999

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle