Sunday, September 10, 2023

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

SUNDAY, SEPTEMBER 10, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0519E
SUNSET:  1803E

OVERCAST SKIES WITH THUNDERSTORMS DEVELOPING, STILL VERY HUMID….

This morning started off cloaked in dense fog with 1/8th of a
mile visibility. The fog lifted by mid morning, but skies
remained overcast with only a few brief periods of filtered
sun. It wasn’t enough however, to create a burn on the sun card.
Despite that, the temperature did make it to the upper 70s
before the rain showers moved in.

The wind shifted to the northeast around noon-time. A fog bank
that was observed over Boston and Boston Harbor at 10am, reached
the hill by the 1pm observation. We are once again socked in with
dense fog this afternoon. We have also been experiencing a
thunderstorm as well, which began around 12:15.

The wind has been light yet again today with an average speed
for the day only around 6mph to this point. The peak gust so far,
which occurred around 11:30 this morning, is only around 17mph.

Visibility has fluctuated today between being in dense fog, and
numerous showers and thunderstorms around the area. The highest
visibility today was around 30 miles late this morning, but has
dropped back to only 1/16th of a mile this afternoon.

The maximum temperature so far today has been 78F, which is
3 degrees above the normal high of 75F. The minimum temperature
since midnight is 69F, which is 11 degrees above the normal low
of 58F.

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Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200ft
Temperature: 71F; Dew Point: 71F; Relative Humidity: 100%
Wind: S @ 5 kts, wind light
Sea-level pressure: 1021.3 mb; 30.16 in. Hg: rising, then more rapidly
Visibility: 1/8 mile, fog
6-hr Max temp: 71F
6-hr Min temp: 70F
24-hr Precip: 0.49 inches
BHO SA 1155 X W2 1/8F 213/71/71/1805/016/ WND LGT/ 8//// 53008
70049 10071 20070

10 A.M.
Weather: Scattered stratus fractus, broken cumulus, overcast altocumulus,
towering cumulus all quadrants, fog bank NNW-ENE
Temperature: 76F; Dew Point: 72F; Relative Humidity: 89%
Wind: S @ 5 kts, wind light
Sea-level pressure: 1021.4 mb; 30.16 in. Hg: rising, then falling
Visibility: 30 miles, 8 miles NNW-ENE, 20 miles WSW-NW
3-hr Precip: 0.00 inches
BHO SA 1455 7 SCT E30 BKN 85 OVC 30 214/76/72/1705/016/ TCU ALQDS
F BNK NNW-ENE VIRGA DSNT ESE-SE AND DSNT S AND DSNT SSW-NW
VSBY 8 NNW-ENE 20 WSW-NW WND LGT/ 8/25/ 50001

1 P.M.
Weather: Sky obscured, vertical visibility 200ft, thunderstorm
with light rain showers
Temperature: 70F; Dew Point: 70F; Relative Humidity: 100%
Wind: NE @ 8 kts
Sea-level pressure: 1020.4 mb; 30.13 in. Hg: falling, then more slowly
Visibility: 1/16 mile, fog
6-hr Max temp: 78F
6-hr Min temp: 70F
6-hr Precip: Trace
BHO SA 1755 X W1 1/16TRW-F 204/70/70/0408/013/ OCNL LTGICCC ALQDS
TB15 RW-B43/ 8//// 56010 6000/ 10078 20070

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SUMMARY FOR SATURDAY, SEPTEMBER 9, 2023

TEMPERATURE (DEGREES F)
MAX…….86   NORMAL…..75
MIN…….68   NORMAL…..58
MEAN……77   NORMAL…..67

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………+10
TOTAL DEPARTURE FOR THE MONTH…………………+64 [+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……..-9
TOTAL HEATING UNITS FOR THE SEASON……………3  DEPARTURE…….-26
TOTAL HEATING UNITS LAST SEASON TO DATE……….7  DEPARTURE……..-4

COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY……………12  DEPARTURE……..+9
TOTAL COOLING UNITS FOR THE MONTH……………92  DEPARTURE…….+55
TOTAL COOLING UNITS FOR THE SEASON………….662  DEPARTURE…….+30
TOTAL COOLING UNITS LAST SEASON TO DATE……..858  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)……….E30 S    @  02:20 P.M.
VECTOR #1 (1-Sec)……….31 S    @  02:20 P.M.
VECTOR #2 (1-Sec)……….30 S    @  02:20 P.M.
DAVIS #1……………….28 S    @  02:19 P.M.
DAVIS #2 ………………34 S    @  02:19 P.M.
RMY #1 (Instantaneous)…..29 S    @  02:20 P.M.
RMY #2 (Instantaneous)…..32 S    @  02:20 P.M.
MERLIN…………………27 S
RICHARDS (C5C) (Inst)……28      @  02:20 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 S    @  02:20 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..21      @  02:20 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..22      @  02:20 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 SSE  @  02:21 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………22 S    @  02:20 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 S    @  02:20 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..22 S    @  02:20 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………19      @  02:20 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..8.0 SW [193 total miles] VECTOR #1………………8.5
VECTOR #2………………8.9
DAVIS #1……………….8.0 SSW
DAVIS #2……………….8.7 SW
RMY #1…………………8.4 SW
RMY #2…………………9.0 SW
RICHARDS (C5C)………….8.3

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.49 DEPARTURE…..+0.37
TOTAL PRECIPITATION FOR THE MONTH…………..0.49 DEPARTURE…..-0.57
TOTAL PRECIPITATION FOR THE YEAR…………..40.94 DEPARTURE…..+5.27

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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 The low since midnight is 69F, the daily normal low is 58F

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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 10
HIGH 90F IN 1931,1989
LOW 41F IN 1956
PRECIP 5.60 INCHES IN 1999 (DAILY RECORD FOR SEPTEMBER)
PEAK GUST 48 MPH NW IN 1972

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)

TODAY’S REPORT PREPARED BY: Matt Douglas