Sunday, September 23, 2018
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, SEPTEMBER 23, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME
A COOL AND CLOUDY DAY WITH LIGHT WIND…
Temperatures stayed cool today, with a high of
only 60F, 12 degrees cooler than our normal high of 72F,
and the same as our daily normal minimum. Pressure began to
decrease as the day progressed, leading to an increase in cloud
cover, especially to our south. This morning at the 7:00
observation, the mountains and coast line were looming due to a
temperature inversion, leading to excellent visibility of several
mountains in New Hampshire that are not normally visible from
the top of Great Blue Hill. Winds have been light, not rising
over 10 kts yet today. The low temperature since midnight
is 47F, 13 degrees below our normal minimum temperature of 60F.
1 PM observation.
Today’s Observations:
7 A.M.
Weather: Scattered stratocumulus, few cumulus distant
in all directions, thin smoke layer W-NE, looming along
horizon below inversion in all directions
Temperature: 48F; Dew Point: 44F; Wind: N at 5 kts
Wind: Light
Sea-level pressure: 30.27 ins. Hg, falling then rising
Visibility: 80 miles
6-hr Max temp: 50F
6-hr Min temp: 47F
24-hr Precip: 0.00 ins.
BHO SA 1155 250 SCT 80 250/48/44/3605/027/ FEW CU DSNT ALQDS
THN K LYR W-NE LOOMING ALG HRZN BLO INVSN ALQDS WND LGT/ 8/108
53008 10050 20047
10 A.M.
Weather: Broken cirrostratus, few cumulus NNW-NNE, thin smoke
layer NW-NE
Wind: Calm
Temperature: 56F; Dew Point: 44F; Wind: W at 2 kts
Sea-level pressure: 30.28 ins. Hg, rising then falling
Visibility: 80 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E250 BKN 80 255/56/44/2602/028/ FEW CU NNW-NNE THN
K LYR NW-NE WND CALM/ 8/108 50005
1 P.M.
Weather: Broken altocumulus, broken cirrus, few cumulus in
all directions
Wind: Light
Temperature: 60F; Dew Point: 46F; Wind: W at 4 kts
Sea-level pressure: 30.26 ins. Hg, steady then falling
Visibility: 80 miles
6-hr Max temp: 60F
6-hr Min temp: 48F
6-hr Precip: 0.00 ins.
BHO SA 1755 E160 BKN 220 BKN 80 247/60/46/2904/026/ FEW CU ALQDS
WND LGT/ 8/134 56008 10060 20048
SUMMARY FOR SATURDAY, SEPTEMBER 22, 2018
TEMPERATURE (DEGREES F)
MAX…..70 NORMAL…..69
MIN…..51 NORMAL…..52
MEAN….61 NORMAL…..61
DEPARTURE FROM 30-YEAR NORMAL…………………..0
TOTAL DEPARTURE FOR THE MONTH………………….+76 [+3.2 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………4 DEPARTURE……….0
TOTAL HEATING UNITS FOR THE MONTH…………..33 DEPARTURE……..-29
TOTAL HEATING UNITS FOR THE SEASON………….33 DEPARTURE……..-54
TOTAL HEATING UNITS LAST SEASON TO DATE……..68 DIFFERENCE…….-35
COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0 DEPARTURE………..0
TOTAL COOLING UNITS FOR THE MONTH………….102 DEPARTURE………+49
TOTAL COOLING UNITS FOR THE SEASON…………855 DEPARTURE……..+265
TOTAL COOLING UNITS LAST SEASON TO DATE…….665 DIFFERENCE…….+190
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………………37 SW AT 12:54 A.M.
AERO……………………..36 SW AT 12:50 A.M.
ASOS……………………..40 SW AT 1:22 A.M.
DAVIS…………………….38 SSW AT 12:18 A.M. RMY 30
FASTEST MILE FOR YESTERDAY…………………..26 SW AT 12:18 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………..29 SSW AT 1:22 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………….29 SSW AT 12:55 A.M.
AVERAGE WIND SPEED AND DIRECTION……………13.0 NNW
ASOS……………………13.2
DAVIS…………………..13.0 WNW [300]
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……….6.46 DEPARTURE……+3.58
ASOS…………..6.53
TOTAL PRECIPITATION FOR THE YEAR……….44.41 DEPARTURE……+6.69
ASOS………….46.05
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
9/01 75/58/67/-1/0.00/521/66 17 NE AERO 15 NE RMY 16
9/02 83/61/72/+4/0.00/684/87 20 SSW AERO 18 SSW RMY N/A
9/03 92/68/80/+13/0.00/650/83 24 WSW AERO 22 WSW RMY 25
9/04 88/70/79/+12/0.00/695/89 17 W AERO 16 W RMY 17
9/05 89/67/78/+11/0.00/638/82 23 SSW AERO 23 SSW RMY 25
9/06 92/70/81/+14/0.56/488/63 29 NNW AERO 29 NNW RMY N/A TSTM
9/07 70/63/67/+1/0.01/000/00 24 NE AERO 22 NE RMY N/A
9/08 68/54/61/-5/0.00/031/04 22 NE AERO 18 NE RMY 21
9/09 61/53/57/-9/0.00/000/00 23 NE AERO 21 NE RMY N/A
9/10 62/56/59/-6/…./…/.. 30 E AERO 28 E RMY 28
9/11 75/61/68/+3/…./…/.. 23 E AERO 21 E RMY N/A TSTM
9/12 69/63/66/+1/…./…/.. 21 ENE AERO 21 ENE RMY 21 TSTM
9/13 68/62/65/+1/…./…/.. 21 NE AERO 21 NE RMY N/A TSTM
9/14 75/61/68/+4/…./…/.. 13 NE AERO 12 ENE RMY 12
9/15 76/62/69/+5/0.01/…/.. 14 SW AERO 13 SW RMY 13
9/16 84/61/73/+10/…./…/.. 15 S AERO 14 S RMY N/A
9/17 82/64/73/+10/…./…/.. 22 SSW AERO 22 SSW RMY N/A
9/18 74/67/71/+9/…./…/.. 31 SSW AERO 30 SSW RMY N/A TSTM
9/19 66/57/62/0/…./…/.. 28 NE AERO 25 NE RMY 26
9/20 63/55/59/-3/…./…/.. 22 NE AERO 21 NE RMY 19
9/21 70/55/63/+2/…./…/.. 37 SSW AERO 37 SSW RMY 41
9/22 70/51/61/0/…./…/.. 37 SW AERO 36 SW RMY 30
9/23 Low temp since midnight is 47F; normal low is now 52F
DAILY RECORDS FOR SEPTEMBER
09/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 70F,
BREAKS PREVIOUS RECORD OF 68F SET IN 1937 AND 1959
09/06/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 92F,
TIES PREVIOUS RECORD OF 92F SET IN 1900
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR SEPTEMBER 23
HIGH 93F IN 1895,1914
LOW 33F IN 1904
PRECIP 2.67 INCHES IN 1994
PEAK GUST 62 MPH SSW IN 1989
RECORDS FOR SEPTEMBER 24
HIGH 87F IN 1959
LOW 33F IN 1885,1950,1963
PRECIP 1.19 INCHES IN 1955
PEAK GUST 54e MPH SW IN 1940
TODAY’S REPORT PREPARED BY: Samantha Richard
