Friday, September 20, 2024

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

FRIDAY, SEPTEMBER 20, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0530E
SUNSET:  1744E

BRIEF PERIODS OF RAIN, GUSTY WINDS IMPACT BLUE HILL TODAY…

The low pressure system from yesterday is still off the coast,
bringing the coastal areas brief periods of rain throughout the day.
So far we have received 0.04 inches of rain today, which gives us a
total of 0.17 inches since yesterday morning. This still puts us
considerably below normal for the month, but every bit helps as parts
of the region has reached the D0 intensity (abnormally dry) on the
US Drought Monitor.

Temperatures have been relatively flat today, thanks in part to the
cloud cover and breezy conditions. While we remain below the normal
high temperatures, we are above average in normal low temperatures which
results in our overall mean temperatures to be close to normal. As a
result of the rain, we have been mostly at 100% relative humidity which
puts the dew points in the upper 50’s. It’s been a damp yet muggy
feeling throughout the day.

The wind remains gusty today, with strong flow out of the NE due
to a mostly static low pressure system that is situated off the
south coast of the state. Our average wind speed so far is about
13 mph, which has gradually increased since this morning. Our peak
gust so far for the day is about 36 mph, which occurred just after
9am. Our record peak gust for the day is 44 mph which was set back
in 1972.

Visibility was impacted by the rain showers this morning, as we only
had about 1/8 mile of visibility during our first observation. With
periodic rain throughout the day, the visibility has fluctuated between
nearly 0 to about 30 miles.

The maximum temperature so far today is 60F, which is 11 degrees below
the normal high of 71F. The minimum temperature since midnight is 59F,
which is 5 degrees above the normal low of 54F.

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Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200ft, light drizzle
Temperature: 60F; Dew Point: 60F; Relative Humidity: 100%
Wind: NE @ 11G23 kts
Sea-level pressure: 1014.7 mb; 29.96 in. Hg: rising unsteadily
Visibility: 1/8 mile, fog
6-hr Max temp: 63F
6-hr Min temp: 60F
24-hr Precip:  0.00 inches
BHO SA 1155 X W2 1/8L-F 147/60/60/0411G23/996/ PCPN VRY LGT/ 8////
52016 6003/ 70013 10063 20060

10 A.M.
Weather: Overcast stratus
Temperature: 59F; Dew Point: 59F; Relative Humidity: 100%
Wind: NE @ 13G23 kts, peak wind NE 36mph at 9:08 A.M.
Sea-level pressure: 1015.8 mb; 30.00 in. Hg: rising, then more slowly
Visibility: 30 miles, thin fog all quadrants
3-hr Precip: 0.02 inches
BHO SA 1455 E3 OVC 30 158/59/59/0413G23/000/ THN F ALQDS PK WND
0431/08/ 8/6// 51011 6002/

1 P.M.
Weather: Overcast stratus, very light drizzle
Temperature: 59F; Dew Point: 59F; Relative Humidity: 100%
Wind: ENE @ 9 kts
Sea-level pressure: 1015.7 mb; 29.99 in. Hg: rising then falling
Visibility: 30 miles, thin fog all quadrants
6-hr Max temp: 60F
6-hr Min temp: 59F
6-hr Precip: 0.04 inches
BHO SA 1755 E8 OVC 30L- 157/59/59/0609/999/ THN F ALQDS PCPN VRY LGT/
8/6// 58001 6004/ 10060 20059

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SUMMARY FOR THURSDAY, SEPTEMBER 19, 2024

TEMPERATURE (DEGREES F)
MAX…….69  NORMAL…..72
MIN…….60  NORMAL…..55
MEAN……65  NORMAL…..63

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………..+2
TOTAL DEPARTURE FOR THE MONTH…………………….+26 [+1.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-4
TOTAL HEATING UNITS FOR THE MONTH……………10  DEPARTURE…….-29
TOTAL HEATING UNITS FOR THE SEASON…………..21  DEPARTURE…….-36
TOTAL HEATING UNITS LAST SEASON TO DATE………17  DEPARTURE……..+4

COOLING DEGREE DAYS (SEASON: JAN 2024 THRU DEC 2024)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE MONTH……………59  DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE SEASON………….753  DEPARTURE…….+96
TOTAL COOLING UNITS LAST SEASON TO DATE……..689  DEPARTURE…….+64

PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all on Main Tower.
E=Estimated

F420C (Official)……….E30 NE   @   03:22 P.M.
VECTOR #1 (1-Sec)……….30 NE   @   03:22 P.M.
VECTOR #2 (1-Sec)……….32 NE   @   02:45 P.M.
DAVIS #1……………….28 NE   @   03:22 P.M.
DAVIS #2 ………………28 ENE  @   03:22 P.M.
RMY #1 (Instantaneous)…..31 NE   @   03:41 P.M.
RMY #2 (Instantaneous)…..31 NE   @   03:22 P.M.
MERLIN…………………27 NE
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 NE   @   02:18 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19      @   02:18 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..19      @   03:54 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 NE   @   02:18 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………19 NE   @   02:18 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..18 NE   @   02:18 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..19 NNE  @   02:18 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….11.3 NE  [272 total miles] VECTOR #1……………..11.2
VECTOR #2……………..11.8
DAVIS #1………………11.7 NE
DAVIS #2………………11.8 ENE
RMY #1………………..10.9 NE
RMY #2………………..11.5 NE
RICHARDS (C5C)………….OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.13 DEPARTURE…..-0.02
TOTAL PRECIPITATION FOR THE MONTH…………..0.17 DEPARTURE…..-2.24
TOTAL PRECIPITATION FOR THE YEAR (2024)…….41.38 DEPARTURE…..+4.36

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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   82/67/75/+6/T/244/31                28 SSW VEC1 27 SW  RMY 28
9/2   79/56/68/-1/0.00/644/82             31 NNW VEC1 31 NNW RMY 32
9/3   74/49/62/-6/0.00/766/98             23 NW  VEC1 23 NNW RMY 23
9/4   80/56/68/0/0.00/732/94              18 ESE VEC1 19 SE  RMY 18
9/5   77/58/68/0/0.00/737/95              20 ESE VEC1 19 ESE RMY 19
9/6   73/58/66/-2/0.00/240/31             22 E   VEC1 21 ENE RMY 23
9/7   77/56/67/0/0.04/301/39              34 WNW VEC1 31 WNW RMY 33
9/8   70/50/60/-7/0.00/753/98             35 W   VEC1 35 W   RMY 34
9/9   75/51/63/-4/0.00/727/95             31 WNW VEC1 28 WNW RMY 30
9/10  78/56/67/+1/0.00/717/94             21 NW  VEC1 20 SW  RMY 21
9/11  78/53/66/0/0.00/714/94              20 S   VEC1 19 S   RMY 18
9/12  82/58/70/+4/0.00/711/94             20 S   VEC1 19 S   RMY 20
9/13  85/59/72/+7/0.00/595/79             21 SSW VEC1 20 SSW RMY 20
9/14  81/61/71/+6/0.00/691/92             21 ENE VEC1 20 ENE RMY 21
9/15  78/60/69/+4/0.00/598/80             23 SE  VEC1 23 SE  RMY 25
9/16  83/55/69/+5/0.00/700/94             22 SSW VEC1 21 SSW RMY 21
9/17  83/55/69/+5/0.00/453/61             16 SW  VEC1 14 S   RMY 15
9/18  77/60/69/+6/0.00/163/22             15 W   VEC1 14 W   RMY 14
9/19  69/60/65/+2/0.10/…/..             30 NE  VEC1 30 NE  RMY 31

9/20  The low since midnight is 59F, the daily normal low is 54F.

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SEPTEMBER DAILY RECORDS TO DATE

NONE.

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

RECORDS FOR SEPTEMBER 20
HIGH 90 IN 1983
LOW 34 IN 1979
PRECIP 4.57 INS IN 1899
PEAK GUST 44 MPH NE IN 1972

RECORDS FOR SEPTEMBER 21
HIGH 91 IN 1895
LOW 35 IN 1929, 1956, 1962
PRECIP 5.58 INS IN 1961 (HURRICANE ESTHER; RETURNED AS TS SEPT 25-26TH)
PEAK GUST 186 MPH S IN 1938 (GREAT NEW ENGLAND HURRICANE; CALCULATED GUST, STATION RECORD)

TODAY’S REPORT PREPARED BY: Amanda Joly