Tuesday, September 19, 2023

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

TUESDAY, SEPTEMBER 19, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0528E
SUNSET:  1747E

SPECTACULAR WEATHER RETURNS TODAY AFTER HEAVY RAINFALL YESTERDAY….

Periods of rain, at times moderate to heavy, continued through
the entire day yesterday. The storm total for the event was
1.56″. This brings the monthly total to over 5″, which now
guarantees us another above normal precipitation month (3rd in
a row, and 5th out of the 9 months this year). The normal
amount for the entire month of September is 4.06″.

Today is featuring mainly sunny skies with some fair weather
cumulus clouds developing, definitely much improved over
yesterday’s conditions.

Temperatures have reached near 70 early this afternoon with
the dew point in the mid 50s. This is very delightful air and
what we’d expect in the latter half of September.

The wind has been on the breezy side today with an average
speed of around 14mph. Frequent gusts between 25-30mph have
been occurring with a peak gust so far for the day of 33mph.

Visibility has been improving as the day progresses, increasing
from 30 miles early this morning to around 60-70 miles early
this afternoon.

The maximum temperature so far today has been 70F, which is
2 degrees below the normal high of 72F. The minimum temperature
since midnight is 56F, which is 1 degree above the normal low
of 55F.

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Today’s Observations:

7 A.M.
Weather: Clear, few stratus fractus all quadrants, few cirrus
distant NE-SE
Temperature: 58F; Dew Point: 57F; Relative Humidity: 96%
Wind: W @ 12G17 kts
Sea-level pressure: 1008.7 mb; 29.79 in. Hg: rising, then more rapidly
Visibility: 30 miles
6-hr Max temp: 60F
6-hr Min temp: 56F
24-hr Precip: 1.42 inches
BHO SA 1155 CLR 30 087/58/57/2712G17/979/ FEW STFRA AQLDS
FEW CI DSNT NE-SE/ 8/701 53022 70142 10060 20056

10 A.M.
Weather: Scattered cumulus
Temperature: 65F; Dew Point: 56F; Relative Humidity: 71%
Wind: W @ 13G20 kts, peak wind W 30mph at 9:27 A.M.
Sea-level pressure: 1010.0 mb; 29.83 in. Hg: rising, then more slowly
Visibility: 50 miles
3-hr Precip: 0.00 inches
BHO SA 1455 25 SCT 50 100/65/56/2813G20/983/ PK WND 2826/27/
8/200 51013

1 P.M.
Weather: Broken cumulus, broken stratocumulus, thin broken cirrus
Temperature: 68F; Dew Point: 54F; Relative Humidity: 60%
Wind: W @ 16G27 kts, peak wind W 31mph at 12:54 P.M.
Sea-level pressure: 1010.4 mb; 29.84 in. Hg: rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 70F
6-hr Min temp: 58F
6-hr Precip: 0.00 inches
BHO SA 1755 E40 BKN 45 BKN 250 -BKN 70 104/68/54/2816G27/984/
PK WND 2827/54/ 8/401 51004 10070 20058

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SUMMARY FOR MONDAY, SEPTEMBER 18, 2023

TEMPERATURE (DEGREES F)
MAX…….64   NORMAL…..72
MIN…….60   NORMAL…..55
MEAN……62   NORMAL…..63

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….-1
TOTAL DEPARTURE FOR THE MONTH…………………+80 [+4.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY…………….3  DEPARTURE……..-1
TOTAL HEATING UNITS FOR THE MONTH……………14  DEPARTURE…….-21
TOTAL HEATING UNITS FOR THE SEASON…………..15  DEPARTURE…….-38
TOTAL HEATING UNITS LAST SEASON TO DATE………23  DEPARTURE……..-8

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…….+59
TOTAL COOLING UNITS FOR THE SEASON………….689  DEPARTURE…….+34
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)……….E33 WNW  @  10:39 P.M.
VECTOR #1 (1-Sec)……….33 WNW  @  10:39 P.M.
VECTOR #2 (1-Sec)……….36 NW   @  11:09 P.M.
DAVIS #1……………….33 W    @  10:39 P.M.
DAVIS #2 ………………33 WNW  @  11:01 P.M.
RMY #1 (Instantaneous)…..35 NW   @  11:12 P.M.
RMY #2 (Instantaneous)…..35 NW   @  11:38 P.M.
MERLIN…………………30 W
RICHARDS (C5C) (Inst)……33      @  10:39 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………24 WNW  @  10:50 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..23      @  10:45 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..25      @  10:41 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………24 W    @  10:45 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………24 WNW  @  10:41 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 WNW  @  10:45 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..24 WNW  @  10:41 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………23      @  10:45 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..8.3 SSE [198 total miles] VECTOR #1………………8.6
VECTOR #2………………9.1
DAVIS #1……………….8.4 SSE
DAVIS #2……………….8.4 SSE
RMY #1…………………8.4 SSE
RMY #2…………………9.1 SSE
RICHARDS (C5C)………….9.0

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..1.42 DEPARTURE…..+1.28
TOTAL PRECIPITATION FOR THE MONTH…………..5.07 DEPARTURE…..+2.81
TOTAL PRECIPITATION FOR THE YEAR…………..45.52 DEPARTURE…..+8.65

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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 The low since midnight is 56F, the daily normal low is 55F

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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 19
HIGH 87F IN 1906,1983
LOW 37F IN 1929
PRECIP 3.69 INCHES IN 1936
PEAK GUST 55 MPH S IN 2012

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

TODAY’S REPORT PREPARED BY: Matt Douglas