Wednesday, September 13, 2023

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

WEDNESDAY, SEPTEMBER 13, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0522E
SUNSET:  1758E

CHANGEABLE SKIES TODAY WITH SOME RAIN SHOWERS….

This morning began with fascinating sky conditions, as there was
fog to the ENE-SSW and a partial undercast to the SSW-N. The
prevailing visibility was only 1 mile, but as low as 1/8th of a
mile in the direction of the fog. Both the fog and partial
undercast lifted by the mid-morning.

The temperature climbed today until it was impeded by increasing
cloud cover and some precipitation, reaching the mid 70’s late
this morning. However, it dropped back to the upper 60’s in the
early afternoon. The dew point has unfortunately remained in the
upper 60’s all day.

It has been a bit breezier on the hill today compared to the past
several days, with an average speed thus far around 7mph. The peak
gust occured in the early afternoon when the showers came through,
clocking in at 23mph.

Visibility improved by mid-morning to 30 miles, but was reduced to
only 4 miles as showers moved through the area.

The maximum temperature so far today has been 76F, which is
2 degrees above the normal high of 74F. The minimum temperature
since midnight is 65F, which is 8 degrees above the normal low
of 57F.

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Today’s Observations:

7 A.M.
Weather: Sky partially obscured, thin broken cirrus, partial undercast
SSW-N, few altocumulus/castellanus SW-NW
Temperature: 67F; Dew Point: 67F; Relative Humidity: 100%
Wind: S @ 4 kts, wind light
Sea-level pressure: 1015.7 mb; 29.99 in. Hg: rising unsteadily
Visibility: 1 mile, 1/8th mile ENE-SSW, 2 miles NW-NNW, fog
6-hr Max temp: 67F
6-hr Min temp: 65F
24-hr Precip: Trace
BHO SA 1155 -X ///BKN E250 -BKN 1F 157/67/67/1904/999/
PARTIAL UNDERCAST SSW-N FEW AC/ACC SW-NW VSBY 1/8 ENE-SSW 2 NW-NNW
WND LGT/ 8/681 52009 70000 10067 20065

10 A.M.
Weather: Broken altocumulus/altostratus, thin broken cirrus, few cumulus
Temperature: 74F; Dew Point: 68F; Relative Humidity: 81%
Wind: S @ 6 kts, wind light
Sea-level pressure: 1015.1 mb; 29.98 in. Hg: falling, then more rapidly
Visibility: 30 miles
3-hr Precip: 0.00 inches
BHO SA 1455 E55 BKN 250 -BKN 30 151/74/68/1806/998/ FEW CU ALQDS
WND LGT/ 8/271 58006

1 P.M.
Weather: Broken stratus fractus, overcast nimbostratus, light rain showers,
few lower stratus fractus all quadrants
Temperature: 69F; Dew Point: 68F; Relative Humidity: 97%
Wind: SSW @ 10 kts
Sea-level pressure: 1014.7 mb; 29.96 in. Hg: falling, then more rapidly
Visibility: 4 miles
6-hr Max temp: 76F
6-hr Min temp: 69F
6-hr Precip: 0.25 inches
BHO SA 1755 E17 BKN 60 OVC 4RW-F 147/69/68/2010/996/ FEW LWR STFRA
ALQDS/ 8/72/ 58004 6025/ 10076 20069

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SUMMARY FOR TUESDAY, SEPTEMBER 12, 2023

TEMPERATURE (DEGREES F)
MAX…….79   NORMAL…..74
MIN…….65   NORMAL…..57
MEAN……72   NORMAL…..66

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….+6
TOTAL DEPARTURE FOR THE MONTH…………………+82 [+6.6 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…….-16
TOTAL HEATING UNITS FOR THE SEASON……………3  DEPARTURE…….-33
TOTAL HEATING UNITS LAST SEASON TO DATE……….7  DEPARTURE……..-4

COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY…………….7  DEPARTURE……..+4
TOTAL COOLING UNITS FOR THE MONTH…………..113  DEPARTURE…….+67
TOTAL COOLING UNITS FOR THE SEASON………….683  DEPARTURE…….+41
TOTAL COOLING UNITS LAST SEASON TO DATE……..873  DEPARTURE……-190

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)……….E18 E    @  12:17 A.M.
VECTOR #1 (1-Sec)……….17 E    @  12:18 A.M.
VECTOR #2 (1-Sec)……….17 ENE  @  12:19 A.M.
DAVIS #1……………….18 E    @  12:17 A.M.
DAVIS #2 ………………17 E    @  12:19 A.M.
RMY #1 (Instantaneous)…..18 E    @  12:17 A.M.
RMY #2 (Instantaneous)…..17 ENE  @  12:19 A.M.
MERLIN…………………M
RICHARDS (C5C) (Inst)……17      @  12:17 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………13 ENE  @  12:21 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..12      @  12:19 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..13      @  12:19 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………14 E    @  12:19 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………14 E    @  12:19 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..14 E    @  12:20 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..13 ENE  @  12:19 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………13      @  12:20 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..4.2 SSW [101 total miles] VECTOR #1………………5.6
VECTOR #2………………5.3
DAVIS #1……………….4.6 S
DAVIS #2……………….4.8 S
RMY #1…………………5.0 WSW
RMY #2…………………5.3 W
RICHARDS (C5C)………….5.5

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….TRACE DEPARTURE…..-0.13
TOTAL PRECIPITATION FOR THE MONTH…………..1.38 DEPARTURE…..-0.06
TOTAL PRECIPITATION FOR THE YEAR…………..41.83 DEPARTURE…..+5.78

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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  74/67/71/+5/0.64/…/..             15 E   VEC1 15 E   RMY 14 TSTM
9/12  79/65/72/+6/T/…/..                18 E   VEC1 17 E   RMY 18

9/13 The low since midnight is 65F, 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 13
HIGH 91F IN 1957
LOW 40F IN 1985
PRECIP 3.10 INCHES IN 1987
PEAK GUST 44 MPH WNW IN 1986

RECORDS FOR SEPTEMBER 14
HIGH 90F IN 1931
LOW 34F IN 1911
PRECIP 2.90 INCHES IN 1944 (Great Atlantic Hurricane in 1944)
PEAK GUST 96e MPH E IN 1944 (Great Atlantic Hurricane in 1944)

TODAY’S REPORT PREPARED BY: Joshua Polen/Matt Douglas