Saturday, September 17, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, SEPTEMBER 17, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

ANOTHER COOL MID-SEPTEMBER EARLY MORNING TODAY
NOT QUITE AS COOL AS 24 HOURS AGO AS HIGH PRESSURE MOVES OFF TO EAST
A SOUTHWESTERLY WIND FLOW WILL BRING WARMER TEMPERATURES

Here at the summit the morning low temperature matched the 54F which
we recorded 24 hours ago this morning. That is exactly the normal low
for this date. Eastern Massachusetts locations subject to radiational
cooling were again down in the low 40’s with even a few upper 30’s being
recorded including nearby Norwood Airport which again dropped into the
upper 30’s. My Hingham station had a low of 45 yesterday morning and
46 this morning.

Patches of shallow dense ground fog could be seen dissipating well to our
west and there was a patch of steam fog over Ponkapoag Pond just to our
south-southeast.

7 A.M.
Weather: Thin scattered cirrus and thin broken cirrus, narrow line of
stratocumulus distant E-SW, thin patch of steam fog dissipating over the
pond in vicinity SSE, patches of shallow dense ground fog dissipated
to the distant WSW-W
Temperature: 57F; Dew Point: 50F; Wind: SW at 7 kts,
Sea-level pressure: 30.29 ins. Hg, rising slightly
Visibility: 50 miles, except 60 miles W-NW, 20 miles S
6-hr Max temp: 57F
6-hr Min temp: 54F
24-hr precip: 0.00 in.
BHO SA 1155 250 -SCT 300 -BKN 50 258/57/50/2307/029/ LONG NARROW PTCH SC LYR
XTDNG DSNT E-SW FEW PTCHS LWR CI PTCH STEAM FG DSSPTG OVR POND VC SSE
PTCHS DNS SHLW GF DSNT WSW-W DSSPTD PST HR VSBY W-NW 60 S 20/ 8/501 53004
10057 20054

10 A.M.
Weather: Scattered cumulus fractus/cumulus, thin scattered cirrus,
thin broken cirrus, few lower cirrus
Temperature: 70F; Dew Point: 55F; Wind: SSW at 11G17 kts,
Wind: Direction variability SSE-WSW
Sea-level pressure: 30.27 ins. Hg, falling then more slowly
Visibility: 60 miles
BHO SA 1455 25 SCT 250 -SCT 300 -BKN 60 252/70/55/2011G17/027/ CUFRA/CU FRMG
WND 15V24/ 8/101 56006

1 P.M.
Weather: Scattered cumulus, thin scattered cirrus, thin broken cirrus
Temperature: 76F; Dew Point: 55F; Wind: SSW at 13G20 kts,
Wind: Direction variability SSE-WSW
Sea-level pressure: 30.20 ins. Hg, falling, then more quickly
Visibility: 55 miles
6-hr Max. temp: 76F
6-hr Min. temp: 57F
BHO SA 1755 37 SCT 250 -SCT 300 -BKN 55 227/76/55/1813G20/020/ LGT DSNT HZ
WND 15V24/ 8/101 58025 10076 20057

SUMMARY FOR FRIDAY, SEPTEMBER 16, 2016

TEMPERATURE (DEGREES F)
MAX…..74   NORMAL…..72
MIN…..54   NORMAL…..55
MEAN….64   NORMAL…..63

DEPARTURE FROM 30-YEAR NORMAL……………………+1
TOTAL DEPARTURE FOR THE MONTH…………………..+45 [+2.6 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE……….-3
TOTAL COOLING UNITS FOR THE MONTH…………..63   DEPARTURE………+18
TOTAL COOLING UNITS FOR THE SEASON…………855   DEPARTURE……..+273
TOTAL COOLING UNITS LAST SEASON TO DATE…….770   DIFFERENCE……..+85

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………1   DEPARTURE……….+2
TOTAL HEATING UNITS FOR THE MONTH……………5   DEPARTURE………-29
TOTAL HEATING UNITS FOR THE SEASON………….16   DEPARTURE………-44
TOTAL HEATING UNITS LAST SEASON TO DATE………6   DIFFERENCE……..+10

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….23 SSE AT  5:46 P.M.
ASOS……………………22 SSE AT  5:46 P.M.
DAVIS…………………..22 SSE AT  5:45 P.M. RMY 24
FASTEST MILE FOR YESTERDAY…………………14 SSW AT  9:44 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………15 SSW AT  9:46 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..15 SSE AT  5:47 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..8.1 S
ASOS……………………8.5
DAVIS…………………..7.4 S [190 Deg.] * Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.31  DEPARTURE……-0.71
ASOS…………..1.30
TOTAL PRECIPITATION FOR THE YEAR……….26.28  DEPARTURE…..-10.76
ASOS………….26.57

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  72/64/68/0/0.09/000/00                  21 NNW AERO 16 NNW RMY 20
9/2  76/58/67/-1/0.00/738/94                 23 ENE AERO 17 NE  RMY 23
9/3  71/56/64/-3/0.00/368/47                 16 E   AERO 12 E   RMY N/A
9/4  71/58/65/-2/0.00/740/95                 28 NE  AERO 21 NE  RMY 27
9/5  73/57/65/-2/0.52/241/31                 42 NNE AER0 33 NNE RMY 43
9/6  70/61/66/-1/0.54/046/06                 32 N   AERO 23 NNE RMY N/A
9/7  78/66/72/+6/0.05/339/44                 21 NE* AERO 15 NE* RMY 21
9/8  79/65/72/+6/T/276/36                    22 S   AERO 15 S   RMY 23
9/9  90/69/80/+14/T/421/55                   23 W   AERO 24 W   RMY 25
9/10 82/71/77/+12/T/…/..                   25 S   AERO 18 S   RMY 32
9/11 79/59/69/+4/0.10/…/..                 39 WNW AERO 30 WNW RMY 43
9/12 76/53/65/0/0.00/…/..                  18 SW* AERO 13 WNW RMY 19
9/13 81/57/69/0/0.00/…/..                  25 SSW AERO  M     RMY 26
9/14 87/58/73/+5/T/…/..                    35 NNW AERO  M     RMY 35
9/15 67/52/60/+9/0.00/…/..                 21 NE  AERO  M     RMY 20
9/16 74/54/64/+1/0.00/…/..                 23 SSE AERO  M     RMY 24

9/17 Low temp since midnight is 54F; normal low is now 54F

DAILY RECORDS FOR SEPTEMBER 2016

9/10/16: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 71F,
BREAKS PREVIOUS RECORD OF 69F SET IN 1915, 1931, AND 1989

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

RECORDS FOR SEPTEMBER 17
HIGH 87F IN 2015
LOW 38F IN 1959
PRECIP 2.73 INCHES IN 1933
PEAK GUST 60 MPH WNW IN 1999

RECORDS FOR SEPTEMBER 18
HIGH 88F IN 1906
LOW 36F IN 1919
PRECIP 4.25 INCHES IN 1996
PEAK GUST 77e MPH WNW IN 1948

TODAY’S REPORT PREPARED BY: Robert Skilling