Saturday, September 16, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, SEPTEMBER 16, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

MORNING DRIZZLE, FOG AND CLOUDS BURNING OFF
THIS AFTERNOON…VERY MUGGY AGAIN TODAY…

A rain shower brought 0.05 inches of additional rainfall
to the summit on Friday afternoon in what remains another
dry month so far. Very light drizzle early this morning
ended before 8:45 AM EST, leaving only a trace of
precipitation for today. Fog and clouds persisted
throughout the morning, though breaks in the stratus are
appearing as of 1 PM EST, and the first sunshine of the
day was observed just after the 1 PM observation. The air
is very humid with dew points holding in the middle 60s
all day, and the visibility has struggled to climb from
about 1 mile early today to about 15 miles this afternoon.
The wind has been generally very light today near 5 kts.

 

Today’s Observations:

7 A.M.
Weather: Sky obscured in light drizzle and fog, few
patches of ground fog S-SW, precipitation very light
Temperature: 66F; Dew Point: 66F; Wind: estimated NNW at 3 kts,
Wind speed: Light
Sea-level pressure: 30.19 ins. Hg, rising then more slowly
Visibility: 1 mile, variable 1/2 to 11/2 miles
6-hr Max temp: 66F
6-hr Min temp: 65F
24-hr Precip:  0.05 inches
BHO SA 1155 W3 X 1VL-F 222/66/66/E3403/019/ FEW PTCHS
GF S-SW VSBY 1/2V11/2 PCPN VRY LGT WND LGT/ 8//// 51013
6000/ 70005 10066 20065

10 A.M.
Weather: Fog, overcast stratus, few patches of ground fog
all quadrants
Temperature: 68F; Dew Point: 66F; Wind: estimated WNW at 2 kts,
Wind speed: Light
Sea-level pressure: 30.20 ins. Hg, rising, then more slowly
Visibility: 6 miles
3-hr Precip: Trace
BHO SA 1455 E3 OVC 6F 227/68/66/E3002/020/ FEW PTCHS
GF ALQDS WND LGT/ 8/6// 51005 6000/

1 P.M.
Weather: Scattered stratus, broken stratus, overcast stratocumulus,
few lower cumulus, few stratus fractus, few breaks in overcast WSW-W
Temperature: 71F; Dew Point: 67F; Wind: NW at 5 kts,
Wind: Light
Sea-level pressure: 30.18 ins. Hg, falling then more quickly
Visibility: 15 miles, visibility N-NE 10, SSE-SSW 20, hazy
6-hr Max temp: 71F
6-hr Min temp: 66F
6-hr Precip: Trace
BHO SA 1755 20 SCT E30 BKN 45 OVC 15 220/71/67/3105/018/
FEW LWR CU FEW STFRA FEW BINOVC WSW-W VSBY N-NE 10 SSE-SSW 20
HAZY WND LGT/ 8/6// 6000/ 58007 10071 20066

 

SUMMARY FOR FRIDAY, SEPTEMBER 15, 2017

TEMPERATURE (DEGREES F)
MAX…..83   NORMAL…..72
MIN…..66   NORMAL…..55
MEAN….75   NORMAL…..64

DEPARTURE FROM 30-YEAR NORMAL……………………+11
TOTAL DEPARTURE FOR THE MONTH…………………….+1 [-0.1 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..10   DEPARTURE……….+8
TOTAL COOLING UNITS FOR THE MONTH…………..46   DEPARTURE……….+3
TOTAL COOLING UNITS FOR THE SEASON…………653   DEPARTURE………+73
TOTAL COOLING UNITS LAST SEASON TO DATE…….855   DEPARTURE……..-202

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-3
TOTAL HEATING UNITS FOR THE MONTH…………..31   DEPARTURE………..0
TOTAL HEATING UNITS FOR THE SEASON………….57   DEPARTURE……….+1
TOTAL HEATING UNITS LAST SEASON TO DATE……..16   DEPARTURE………+41

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….18 WNW AT  4:32 P.M.
AERO……………………15 WNW AT  4:32 P.M. *
ASOS……………………19 WNW AT  4:32 P.M.
DAVIS…………………..19 SSW AT  8:02 A.M. RMY 18
FASTEST MILE FOR YESTERDAY…………………13 S   AT  2:59 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE………………14 NW  AT  4:33 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..13 NW  AT  4:33 P.M.
AVERAGE WIND SPEED AND DIRECTION…………. 7.0 SSW
ASOS…………………..6.7
DAVIS………………….4.3 SSW [200 DEG.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.05  DEPARTURE……-0.08
ASOS…………..0.04
TOTAL PRECIPITATION FOR THE MONTH……….1.57  DEPARTURE……-0.31
ASOS…………..1.59
TOTAL PRECIPITATION FOR THE YEAR……….37.93  DEPARTURE……+1.03
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  74/58/66/0/0.79/417/54                24*WSW AERO 23 WSW RMY 24
9/8  74/53/64/-2/0.00/577/75               21 WSW AERO 18 WSW RMY 22
9/9  68/51/60/-5/T/620/81                  18 ENE AERO 16 ENE RMY 18
9/10 71/51/61/-4/0.00/694/91               18 NW  AERO 16 NW  RMY N/A
9/11 78/50/64/-1/0.00/692/91               20 NNW AERO 17 NNW RMY 20
9/12 84/58/71/+6/0.00/690/91               22 WSW AERO 18 WSW RMY 23
9/13 84/59/72/+8/T/680/90                  18 WSW AERO 15 WSW RMY 20 TSTM
9/14 82/66/74/+10/0.00/233/31              23 SW  AERO 23 WSW RMY 25 TSTM
9/15 83/66/75/+11/0.05/300/40              18 WNW AERO 15 WNW RMY 18

9/16 Low temp since midnight is 65F; 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 16
HIGH 91F IN 1939,1941
LOW 39F IN 1984
PRECIP 5.12 INCHES IN 1933 (Hurricane)
PEAK GUST 59 MPH SSE IN 1999

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

TODAY’S REPORT PREPARED BY: Mike Iacono