Tuesday, December 13, 2022

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

TUESDAY, DECEMBER 13, 2022
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0705E
SUNSET:  1612E

ABUNDANT SUNSHINE AND A LITTLE LESS COLD, BUT STILL BRISK….

After failing to get above freezing the last 3 days here
on the summit of Blue Hill, today the temperature has
managed to rise into the upper 30s. Under plenty of bright
sunshine, it actually doesn’t feel that bad in the sun.
However the brisk wind is generating a stiff wind chill in
the 20s that’s no fun if you’re experiencing it in the
shade.

We had our coldest temperature of the season so far this
morning with a low of 19F!

The dew point has been gradually rising from the low teens
early this morning to near 20 early this afternoon. This
is a sign that the arctic air mass that’s been over the
region through the weekend into this morning is finally
heading out.

The wind as mentioned has been on the busy side with an
average speed for the day thus far around 15mph. Gusts
have been getting to between 35-40mph this afternoon.

Visibility is excellent today under almost completely
clear skies. Views of 70 miles early this morning have
increased to a perfect 90 miles early this afternoon.

The high so far today is 38F, which is 3 degrees below
the normal maximum of 41F. The low since midnight is 19F,
which is 7 degrees below the normal minimum of 26F.

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Today’s Observations:

7 A.M.
Weather: Clear, few stratocumulus offshore distant NNE-SE
Temperature: 21F; Dew Point: 13F; Relative Humidity: 70%
Wind: NNW @ 12G18 kts
Sea-level pressure: 1021.9 mb; 30.18 in. Hg: falling, then rising
Visibility: 70 miles
6-hr Max temp: 22F
6-hr Min temp: 19F
24-hr Precip:  Trace
24-hr Snowfall: Trace
Snow Depth: 1 inch
BHO SA 1155 CLR 70 219/21/13/3312G18/018/ FEW SC OFFSHR DSNT NNE-SE/
8/500 4/001 53008 70000 10022 20019

10 A.M.
Weather: Clear, few stratocumulus offshore distant NNE-SE
Temperature: 29F; Dew Point: 17F; Relative Humidity: 61%
Wind: NNW @ 12G22 kts
Sea-level pressure: 1022.2 mb; 30.19 in. Hg: rising then falling
Visibility: 80 miles
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 CLR 80 222/29/17/3312G22/019/ FEW SC OFFSHR DSNT NNE-SE/
8/500 50003

1 P.M.
Weather: Clear, few stratocumulus offshore distant NNE-SE
Temperature: 37F, Dew point: 19F; Relative Humidity: 48%
Wind: NNW @ 13G23 kts
Sea-level pressure: 1019.8 mb; 30.11 in Hg: falling, then more rapidly
Visibility: 90 miles
6-hr Max temp: 38F
6-hr Min temp: 21F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
Snow Depth: 1 inch
BHO SA 1755 CLR 90 198/37/19/3313G23/011/ FEW SC OFFSHR DSNT NNE-SE/
8/500 4/001 58024 10038 20021

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SUMMARY FOR MONDAY, DECEMBER 12, 2022

TEMPERATURE (DEGREES F)
MAX…….29   NORMAL…..41
MIN…….21   NORMAL…..26
MEAN……25   NORMAL…..34

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………-9
TOTAL DEPARTURE FOR THE MONTH………………..+28 [+2.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2022 THRU JUN 2023)
TOTAL HEATING UNITS FOR YESTERDAY……………40  DEPARTURE……..+9
TOTAL HEATING UNITS FOR THE MONTH…………..329  DEPARTURE…….-29
TOTAL HEATING UNITS FOR THE SEASON…………1298  DEPARTURE……-264
TOTAL HEATING UNITS LAST SEASON TO DATE…….1324  DEPARTURE…….-26

PEAK WIND GUST (MPH):
Official (1-Sec AVG)…….24 N   @  1:29 P.M.
VECTOR #2 (Instantaneous)..27     @  1:29 P.M.
DAVIS #2 ………………22 N   @  1:30 P.M.
RMY #2 (Instantaneous)…..24 N   @  1:29 P.M.
VECTOR #1……OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…….OUT OF SERVICE D/T RENOVATIONS
RMY #1………OUT OF SERVICE D/T RENOVATIONS
MERLIN………OUT OF SERVICE D/T RENOVATIONS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………17 NNW @ 11:56 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17     @  1:31 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 N   @  1:31 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 N   @  1:31 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE….OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE RMY #1 AVERAGE……OUT OF SERVICE D/T RENOVATIONS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….11.6 N [279 total miles] VECTOR #2……………..11.8
DAVIS #2………………11.2 N
RMY #2………………..11.8 N
RMY #1……….OUT OF SERVICE D/T RENOVATIONS
VECTOR #1…….OUT OF SERVICE D/T RENOVATIONS
DAVIS #1……..OUT OF SERVICE D/T RENOVATIONS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….TRACE DEPARTURE…..-0.18
TOTAL PRECIPITATION FOR THE MONTH…………..1.44 DEPARTURE…..-0.71
TOTAL PRECIPITATION FOR THE YEAR…………..38.51 DEPARTURE….-12.11

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………TRACE DEPARTURE……-0.4
TOTAL SNOWFALL FOR THE MONTH………………..2.5 DEPARTURE……-1.2
TOTAL SNOWFALL FOR THE SEASON (2022-2023)…….2.5 DEPARTURE……-3.7

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PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

12/1  40/30/35/-2/0.00/0.0/520/93         54 NW   AERO N/A    RMY 60
12/2  44/27/36/-1/0.00/0.0/535/96         24 SSW  AERO N/A    RMY 25
12/3  57/36/47/+11/0.31/0.0/000/00        54 SSW  AERO N/A    RMY 57
12/4  41/30/36/0/0.00/0.0/355/64          39 WNW  AERO N/A    RMY 41
12/5  48/29/39/+3/0.00/0.0/454/82         32 SSW  AERO N/A    RMY 32
12/6  54/38/46/+11/0.09/0.0/000/00        30 SSE  AERO N/A    RMY 31
12/7  56/46/51/+16/0.85/0.0/…/..        39 SSE  AERO N/A    RMY 39
12/8  53/33/43/+8/0.00/0.0/…/..         36 NNW  AERO N/A    RMY 39
12/9  44/29/37/+3/0.00/0.0/…/..         29 N    AERO N/A    RMY 30
12/10 31/27/29/-5/0.04/0.4/…/..         27 NE   AERO N/A    RMY 26
12/11 30/23/27/-7/0.15/2.1/…/..         25 NNE  AERO N/A    RMY 26
12/12 29/21/25/-9/T/T/…/..              24 N    AERO N/A    RMY 24

12/13 The low since midnight is 19F, the daily normal low is 26F

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)

RECORDS FOR DECEMBER 13
HIGH 60 IN 1984
LOW 0 IN 1893
PRECIP 1.45 INS. IN 1983
SNOWFALL 9.2 INS. IN 2007
PEAK GUST 81e WNW IN 1976

RECORDS FOR DECEMBER 14
HIGH 62 IN 1901
LOW -6 IN 1893
PRECIP 1.94 INS. IN 2002
SNOWFALL 8.0 INS. IN 1907
PEAK GUST 78e ENE IN 1941

TODAY’S REPORT PREPARED BY: Matt Douglas