Wednesday, September 20, 2023

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

WEDNESDAY, SEPTEMBER 20, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0529E
SUNSET:  1745E

ANOTHER BEAUTIFUL SEPTEMBER DAY WITH SUNSHINE AND SEASONABLE TEMPS….

Today is offering yet another splendid day with plenty of
sunshine, seasonably mild temperatures, and comfortable humidity
levels. Once again, some fair weather cumulus clouds are popping
up, but they are not as numerous in coverage as they were
yesterday afternoon.

Temperatures have reached the low 70s early this afternoon with
the dew point in the low to mid 50s. Definitely an excellent
day for outdoor activities.

The wind has been steady out of the west-northwest, but lighter
than yesterday. The average speed so far is around 10mph.

Visibility has been quite decent all day ranging between 60-70
miles.

The maximum temperature so far today has been 72F, which is
1 degree above the normal high of 71F. The minimum temperature
since midnight is 53F, which is 1 degree below the normal low
of 54F.

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Today’s Observations:

7 A.M.
Weather: Thin scattered cirrus, few altocumulus distant SSW-WNW
Temperature: 56F; Dew Point: 53F; Relative Humidity: 89%
Wind: WNW @ 8 kts
Sea-level pressure: 1019.5 mb; 30.11 in. Hg: rising, then more rapidly
Visibility: 70 miles
6-hr Max temp: 56F
6-hr Min temp: 53F
24-hr Precip: 0.00 inches
BHO SA 1155 250 -SCT 70 195/56/53/3008/011/ FEW AC DSNT SSW-WNW/
8/051 53014 10056 20053

10 A.M.
Weather: Clear, few stratocumulus all quadrants, few cirrus distant
NE-S-WSW
Temperature: 67F; Dew Point: 54F; Relative Humidity: 62%
Wind: NW @ 7 kts
Sea-level pressure: 1020.0 mb; 30.12 in. Hg: rising then falling
Visibility: 60 miles
3-hr Precip: 0.00 inches
BHO SA 1455 CLR 60 200/67/54/3107/012/ FEW SC ALQDS FEW CI DSNT
NE-S-WSW/ 8/501 50005

1 P.M.
Weather: Clear, few small cumulus all quadrants, few cirrus distant
ESE-S-W
Temperature: 71F; Dew Point: 52F; Relative Humidity: 52%
Wind: WNW @ 6 kts, wind light
Sea-level pressure: 1009.3 mb; 30.10 in. Hg: falling, then more slowly
Visibility: 60 miles
6-hr Max temp: 72F
6-hr Min temp: 56F
6-hr Precip: 0.00 inches
BHO SA 1755 CLR 60 193/71/52/3006/010/ FEW SML CU ALQDS FEW CI DSNT
ESE-S-W WND LGT/ 8/101 56007 10072 20056

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SUMMARY FOR TUESDAY, SEPTEMBER 19, 2023

TEMPERATURE (DEGREES F)
MAX…….70   NORMAL…..72
MIN…….56   NORMAL…..55
MEAN……63   NORMAL…..63

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………..0
TOTAL DEPARTURE FOR THE MONTH…………………+80 [+4.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY…………….2  DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE MONTH……………16  DEPARTURE…….-23
TOTAL HEATING UNITS FOR THE SEASON…………..17  DEPARTURE…….-40
TOTAL HEATING UNITS LAST SEASON TO DATE………27  DEPARTURE…….-10

COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-2
TOTAL COOLING UNITS FOR THE MONTH…………..119  DEPARTURE…….+58
TOTAL COOLING UNITS FOR THE SEASON………….689  DEPARTURE…….+32
TOTAL COOLING UNITS LAST SEASON TO DATE……..884  DEPARTURE……-195

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)……….E35 WNW  @  03:42 P.M.
VECTOR #1 (1-Sec)……….37 WNW  @  03:42 P.M.
VECTOR #2 (1-Sec)……….36 WNW  @  03:19 P.M.
DAVIS #1……………….35 W    @  03:33 P.M.
DAVIS #2 ………………35 WNW  @  03:42 P.M.
RMY #1 (Instantaneous)…..36 WNW  @  03:42 P.M.
RMY #2 (Instantaneous)…..38 WNW  @  03:19 P.M.
MERLIN…………………33 W
RICHARDS (C5C) (Inst)……38      @  03:42 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………27 W    @  02:41 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..25      @  02:41 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..26      @  03:52 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………26 W    @  02:41 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 WNW  @  03:52 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..24 W    @  02:41 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..25 WNW  @  03:52 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………25      @  02:41 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..15.1 W [362 total miles] VECTOR #1………………14.7
VECTOR #2………………15.0
DAVIS #1……………….15.4 W
DAVIS #2……………….14.8 WNW
RMY #1…………………13.8 W
RMY #2…………………14.7 WNW
RICHARDS (C5C)………….14.6

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.15
TOTAL PRECIPITATION FOR THE MONTH…………..5.07 DEPARTURE…..+2.66
TOTAL PRECIPITATION FOR THE YEAR…………..45.52 DEPARTURE…..+8.50

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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/+15/0.00/726/94            20 SSW VEC1 21 SSW RMY 21
9/8   86/70/78/+11/0.00/293/38            30 SSW VEC1 31 SSW RMY 32 TSTM
9/9   86/68/77/+10/0.49/291/38            30 S   VEC1 31 S   RMY 29 TSTM
9/10  78/67/73/+7/0.25/008/01             17 NE  VEC1 17 NE  RMY 15 TSTM
9/11  74/67/71/+5/0.64/023/03             15 E   VEC1 15 E   RMY 14 TSTM
9/12  79/65/72/+6/T/250/33                18 E   VEC1 17 E   RMY 18
9/13  76/64/70/+5/1.92/242/32             35 SSW VEC1 35 SSW RMY 36 TSTM
9/14  75/57/66/+1/0.00/670/89             24 NW  VEC1 24 NW  RMY 24
9/15  66/53/60/-5/0.00/465/62             36 N   VEC1 35 N   RMY 35
9/16  68/54/61/-3/0.21/022/03             44 WNW VEC1 44 WNW RMY 47
9/17  76/53/65/+1/0.00/685/92             26 WNW VEC1 25 WNW RMY 24
9/18  64/60/62/-1/1.56/000/00             33 WNW VEC1 33 WNW RMY 35 TSTM
9/19  70/56/63/0/0.00/…/..              35 WNW VEC1 37 WNW RMY 36

9/20 The low since midnight is 53F, the daily normal low is 54F

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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 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: Matt Douglas