Monday, September 11, 2023
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
MONDAY, SEPTEMBER 11, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0520E
SUNSET: 1801E
OVERCAST SKIES WITH SHOWERS AND THUNDERSTORMS DEVELOPING ONCE
AGAIN….
This morning started off cloaked in dense fog with 1/16th to
1/8th of a mile visibility. We’ve spent most of the day in the
fog, however it did lift for a couple of hours early in the
afternoon before moving back in just ahead of showers and
thunderstorms. It has become increasingly stormy as the
afternoon progresses.
The temperature has been held back today due to all the cloud
cover and fog, with the high barely reaching the mid 70s.
However the dew point remains on the high side with values
just under 70F. We’re really looking forward to a period of
lower humidity levels expected later this week.
The wind has been light yet again today with an average speed
for the day only around 5mph. The peak gust so far, which occurred
around 1:30 this afternoon, is a pitiful 13mph.
Visibility has fluctuated today between being in dense fog, and
numerous showers and thunderstorms around the area. The highest
visibility today was briefly around 20 miles early this afternoon,
but has dropped back to only 1/16th as the dense fog settled
back onto the summit.
The maximum temperature so far today has been 74F, which is
1 degree below the normal high of 75F. The minimum temperature
since midnight is 67F, which is 10 degrees above the normal low
of 57F.
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Today’s Observations:
7 A.M.
Weather: Sky obscured, vertical visibility 200ft, light drizzle
Temperature: 67F; Dew Point: 67F; Relative Humidity: 100%
Wind: E @ 3 kts, wind light
Sea-level pressure: 1018.3 mb; 30.07 in. Hg: falling, then rising
Visibility: 1/8 mile, fog
6-hr Max temp: 67F
6-hr Min temp: 67F
24-hr Precip: 0.25 inches
BHO SA 1155 X W2 1/8L-F 183/67/67/0903/007/ L-B50 WND LGT/ 8//// 53001
6000/ 70025 10067 20067
10 A.M.
Weather: Sky obscured, vertical visibility 100ft
Temperature: 69F; Dew Point: 69F; Relative Humidity: 100%
Wind: E @ 4 kts, wind light
Sea-level pressure: 1018.5 mb; 30.08 in. Hg: rising, then steady
Visibility: 1/16 mile, fog
3-hr Precip: Trace
BHO SA 1455 X W1 1/16F 185/69/69/0904/008/ WND LGT/ 8//// 51002 6000/
1 P.M.
Weather: Broken stratocumulus, broken altocumulus, overcast cirrostratus,
towering cumulus SSE-SSW, few breaks in overcast W-WNW
Temperature: 72F; Dew Point: 69F; Relative Humidity: 91%
Wind: ENE @ 5 kts, wind light
Sea-level pressure: 1017.3 mb; 30.04 in. Hg: falling, then more rapidly
Visibility: 20 miles, 10 miles N-NE
6-hr Max temp: 74F
6-hr Min temp: 67F
6-hr Precip: Trace
BHO SA 1755 E4 BKN 95 BKN 200 OVC 20 173/72/69/0605/004/ TCU SSE-SSW
FEW BINOVC W-WNW FEW LWR STFRA ALQDS VSBY 10 N-NE WND LGT/ 8/557
58012 6000/ 10074 20067
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SUMMARY FOR SUNDAY, SEPTEMBER 10, 2023
TEMPERATURE (DEGREES F)
MAX…….78 NORMAL…..75
MIN…….67 NORMAL…..58
MEAN……73 NORMAL…..66
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….+7
TOTAL DEPARTURE FOR THE MONTH…………………+71 [+6.9 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY…………….0 DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE MONTH…………….2 DEPARTURE…….-11
TOTAL HEATING UNITS FOR THE SEASON……………3 DEPARTURE…….-28
TOTAL HEATING UNITS LAST SEASON TO DATE……….7 DEPARTURE……..-4
COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY…………….8 DEPARTURE……..+5
TOTAL COOLING UNITS FOR THE MONTH…………..100 DEPARTURE…….+60
TOTAL COOLING UNITS FOR THE SEASON………….670 DEPARTURE…….+34
TOTAL COOLING UNITS LAST SEASON TO DATE……..866 DEPARTURE……-196
PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all Main Tower.
E=Estimated
F420C (Official)……….E17 NE @ 12:47 P.M.
VECTOR #1 (1-Sec)……….17 NE @ 11:30 A.M.
VECTOR #2 (1-Sec)……….16 NE @ 12:40 P.M.
DAVIS #1……………….16 NE @ 11:30 A.M.
DAVIS #2 ………………15 ENE @ 12:40 P.M.
RMY #1 (Instantaneous)…..15 NE @ 12:40 P.M.
RMY #2 (Instantaneous)…..15 NE @ 12:40 P.M.
MERLIN…………………14 NE
RICHARDS (C5C) (Inst)……14 @ 12:40 P.M.
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………12 NE @ 12:46 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..12 @ 12:47 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..12 @ 12:48 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………12 NE @ 12:48 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………12 ENE @ 12:48 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..12 NE @ 12:47 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..12 NE @ 12:48 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………12 @ 12:47 P.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..4.7 NE [112 total miles]
VECTOR #1………………5.3
VECTOR #2………………5.6
DAVIS #1……………….4.8 SE
DAVIS #2……………….5.1 SE
RMY #1…………………5.3 SE
RMY #2…………………5.6 SE
RICHARDS (C5C)………….5.8
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.25 DEPARTURE…..+0.12
TOTAL PRECIPITATION FOR THE MONTH…………..0.74 DEPARTURE…..-0.45
TOTAL PRECIPITATION FOR THE YEAR…………..41.19 DEPARTURE…..+5.39
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PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN)/SUN(%)/PEAK GUST/VEC1/RMY GUST
PEAK GUST: F420C (Official)
VEC1: Vector #1 1-second gust
RMY: R.M. Young #1 wind gust recording system (Instantaneous)
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M: Missing data
9/1 73/52/63/-6/0.00/774/98 23 SSW VEC1 22 SSW RMY 21
9/2 79/56/68/-1/0.00/708/90 25 SW VEC1 24 SW RMY 26
9/3 85/61/73/+5/T/674/86 21 SW VEC1 21 SW RMY 21
9/4 85/68/77/+9/0.00/719/92 17 NW VEC1 16 NW RMY 16
9/5 86/68/77/+9/0.00/647/83 16 NNE VEC1 16 ENE RMY 16
9/6 89/70/80/+12/0.00/722/93 17 WSW VEC1 17 SSW RMY 18
9/7 92/72/82/+15/0.00/…/.. 20 SSW VEC1 21 SSW RMY 21
9/8 86/70/78/+11/0.00/…/.. 30 SSW VEC1 31 SSW RMY 32 TSTM
9/9 86/68/77/+10/0.49/…/.. 30 S VEC1 31 S RMY 29 TSTM
9/10 78/67/73/+7/0.25/…/.. 17 NE VEC1 17 NE RMY 15 TSTM
9/11 The low since midnight is 67F, the daily normal low is 57F
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SEPTEMBER DAILY RECORDS
09/07/2023: NEW RECORD HIGH DAILY MINIMUM TEMPERATURE OF 72F;
BEATS THE RECORD OF 70F SET IN 1999
09/07/2023: RECORD HIGH TEMPERATURE OF 92F;
TIES THE RECORD OF 92F SET IN 2007 AND 2015
09/08/2023: RECORD HIGH DAILY MINIMUM TEMPERATURE OF 70F;
TIES THE RECORD OF 70F SET IN 2015
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DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR SEPTEMBER 11
HIGH 93F IN 1983, 2013
LOW 37F IN 1917
PRECIP 5.23 INCHES IN 1954 (HURRICANE EDNA)
PEAK GUST 101 MPH NW IN 1954 (HURRICANE EDNA)
RECORDS FOR SEPTEMBER 12
HIGH 92F IN 1961
LOW 42F IN 1958,1967,1985
PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA)
PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA)
TODAY’S REPORT PREPARED BY: Matt Douglas
