Friday, October 20, 2023

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

FRIDAY, OCTOBER 20, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0603E
SUNSET:  1655E

MUCH COOLER AND FALL-LIKE TODAY ON GREAT BLUE HILL…

Even though temperatures are similar to yesterday, it feels
much cooler thanks to the overcast skies and more steady
wind. Dew points have risen to the upper 50’s but with the
temperatures in the low 60’s this afternoon, it hasn’t felt
bad at all.

The wind has been pretty steady today, with winds mostly from
the SSE. Our average so far is about 12mph and our peak gust
occurred just before 1pm at about 25mph.

We started this morning in the clouds, as a layer of fog and
low hanging stratus fractus clouds gave us a rather poor
visibility. As the temperatures warmed and the clouds lifted
we recovered to about 40 miles for the remainder of the morning
and early afternoon.

The maximum temperature so far today has been 62F, which is 2
degrees above the normal high of 60F. The minimum temperature
since midnight is 50F, which is 8 degrees above the normal low
of 42F.

As we continue to remain above normal in the minimum temperature
category, we are actively tracking when we will have our first
low temperature below 40F. Here are the current rankings as
compiled by our Chief Scientist, Mike Iacono.

BHO Latest First Minimum Temperature Below 40 deg F (1885-2023):

1) 24 October 2013 (36F)
24 October 2021 (37F)
3) 22 October 1955 (34F)
4) 21 October 2005 (39F)
5) 20 October 1960 (38F)
6) 19 October 2014 (39F)

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Today’s Observations:

7 A.M.
Weather: Fog, broken altocumulus, broken cirrus
Temperature: 53F; Dew Point: 53F; Relative Humidity: 100%
Wind: SSE @ 8 kts
Sea-level pressure: 1015.0 mb; 29.97 in. Hg: falling, then more
slowly
Visibility: 3 miles, 6 miles WNW-NE, 1 mile N-NE
6-hr Max temp: 53F
6-hr Min temp: 50F
24-hr Precip: 0.00 inches
BHO SA 1155 E1 BKN 85 BKN 250 BKN 3F 150/53/53/1608/997/
VSBY 6 WNW-NW 1 N-NE/ 8/651 56012 10053 20050

10 A.M.
Weather: Overcast, broken altostratus, few lower stratus fractus
distant all quadrants, few cumulus NE-SE-W
Temperature: 58F; Dew Point: 58F; Relative Humidity: 100%
Wind: SSE @ 7 kts
Sea-level pressure: 1013.9 mb; 29.94 in. Hg: falling, then more
slowly
Visibility: 40 miles
3-hr Precip: 0.00 inches
BHO SA 1455 E85 OVC 40 139/58/58/1507/994/ FEW LWR STFRA DSNT
ALQDS FEW CU NE-SE-W 8/21/ 56011

1 P.M.
Weather: Broken cumulus, broken altostratus, overcast cirrostratus,
few breaks in overcast distant NNW
Temperature: 62F; Dew Point: 57F; Relative Humidity: 81%
Wind: SSE @ 8 kts
Sea-level pressure: 1010.6 mb; 29.84 in. Hg: falling, then more
rapidly
Visibility: 40 miles
6-hr Max temp: 62F
6-hr Min temp: 53F
6-hr Precip: 0.00 inches
BHO SA 1755 E50 BKN 120 BKN 250 OVC 40 106/62/57/1608/984/
FEW BINOVC DSNT NNW/ 8/238 58033 10062 20053

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SUMMARY FOR THURSDAY, OCTOBER 19, 2023

TEMPERATURE (DEGREES F)
MAX…….65   NORMAL…..60
MIN…….50   NORMAL…..43
MEAN……58   NORMAL…..51

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….+7
TOTAL DEPARTURE FOR THE MONTH…………………+76 [+3.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY…………….7  DEPARTURE……..-7
TOTAL HEATING UNITS FOR THE MONTH…………..135  DEPARTURE…….-67
TOTAL HEATING UNITS FOR THE SEASON………….234  DEPARTURE…….-86
TOTAL HEATING UNITS LAST SEASON TO DATE……..277  DEPARTURE…….-43

COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH……………15  DEPARTURE……..+9
TOTAL COOLING UNITS FOR THE SEASON………….704  DEPARTURE…….+27
TOTAL COOLING UNITS LAST SEASON TO DATE……..884  DEPARTURE……-180

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)……….E31 SSW  @  04:46 P.M.
VECTOR #1 (1-Sec)……….30 SSW  @  04:38 P.M.
VECTOR #2 (1-Sec)……….30 SSW  @  03:46 P.M.
DAVIS #1……………….30 S    @  04:44 P.M.
DAVIS #2 ………………33 S    @  04:22 P.M.
RMY #1 (Instantaneous)…..33 SSW  @  04:46 P.M.
RMY #2 (Instantaneous)…..31 SSW  @  04:46 P.M.
MERLIN…………………30 S
RICHARDS (C5C) (Inst)……32      @  04:46 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………23 SSW  @  04:46 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..21      @  04:46 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..23      @  04:45 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………22 SSW  @  04:47 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………24 SSW  @  04:46 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..21 SSW  @  04:46 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..23 SSW  @  04:46 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………21      @  04:47 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….10.9 SSW [262 total miles] VECTOR #1……………..11.4
VECTOR #2……………..12.1
DAVIS #1………………10.9 SSW
DAVIS #2………………12.4 SSW
RMY #1………………..11.2 SSW
RMY #2………………..12.2 SSW
RICHARDS (C5C)…………11.0

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.18
TOTAL PRECIPITATION FOR THE MONTH…………..0.23 DEPARTURE…..-3.06
TOTAL PRECIPITATION FOR THE YEAR…………..47.45 DEPARTURE…..+5.49

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PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 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

10/1  68/50/59/+1/0.00/458/65             20 NNE VEC1 20 NNE RMY 19
10/2  68/55/62/+4/0.00/681/97             24 NE  VEC1 23 NE  RMY 24
10/3  81/54/68/+11/0.00/672/96            18 WSW VEC1 18 WSW RMY 18
10/4  81/64/73/+16/0.00/669/96            17 S   VEC1 17 S   RMY 16
10/5  77/59/68/+11/0.00/638/92            24 S   VEC1 24 S   RMY 23
10/6  71/60/66/+10/0.00/269/39            20 SE  VEC1 19 SE  RMY 18
10/7  68/54/61/+5/0.16/007/01             30 WNW VEC1 29 WNW RMY 29
10/8  63/48/56/+1/0.00/651/95             30 W   VEC1 30 WNW RMY 30
10/9  61/44/53/-2/0.00/532/78             25 WSW VEC1 24 WSW RMY 25
10/10 64/47/56/+1/T/245/36                23 W   VEC1 22 W   RMY 21
10/11 68/50/59/+5/0.00/393/58             23 SSW VEC1 22 SW  RMY 22
10/12 69/51/60/+6/0.00/479/71             18 NW  VEC1 18 NNW RMY 18
10/13 61/43/52/-2/0.00/638/95             33 NW  VEC1 31 NW  RMY 34
10/14 60/44/52/-1/0.00/247/37             24 NW  VEC1 23 NW  RMY 23
10/15 59/44/52/-1/0.00/226/34             24 NNW VEC1 25 NNW RMY 25
10/16 58/44/51/-1/0.07/166/25             17 WNW VEC1 17 WNW RMY 17
10/17 60/45/53/+1/T/211/32                15 N   VEC1 15 N   RMY 14
10/18 62/49/56/+4/0.00/079/12             15 SSW VEC1 15 SSW RMY 16
10/19 65/50/58/+8/0.00/…/..             31 SSW VEC1 30 SSW RMY 33

10/20 The low since midnight is 50F, the daily normal low is 42F

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OCTOBER 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 OCTOBER 20
HIGH 78F IN 1965,1984
LOW 24F IN 1972
PRECIP 7.10 INCHES IN 1996 (RECORD FOR MONTH)
SNOWFALL TRACE IN 1934,1943
PEAK GUST 63 MPH W IN 1966

RECORDS FOR OCTOBER 21
HIGH 79F IN 1979
LOW 24F IN 1974
PRECIP 2.34 INCHES IN 1944
SNOWFALL TRACE IN 1895,1907,1941
PEAK GUST 69e MPH S IN 1976

TODAY’S REPORT PREPARED BY: Amanda Joly