Monday, January 20, 2025
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
MONDAY, JANUARY 20, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0708E
SUNSET: 1643E
ARCTIC AIR MASS MOVES IN ON THE HEELS OF WINTER STORM….
It looks like a winter wonderland up here on Great Blue Hill yet
again, and with the arctic air mass moving into place, it certainly
feels it too. Precipitation began here as rain yesterday evening,
before changing fully over to snow by 8pm. Snow continued into the
early morning hours, though by then the intensity was rather light.
Snowfall accumulated 5.7″, which brings our season total to exactly
20.0″. The liquid equivalent precipitation was 0.59″.
Temperatures dropped steadily through the overnight, and despite the
current abundant sunshine, they have struggled to rise. The low of 13F
occurred around 7:30am, and since we have only made it to the low 20s
by the final observation. The high occurred just after midnight. The dew
point dropped through the night but has remained steady in the low teens
for the past few hours.
There is a decent breeze out of the west-northwest, helping to advect
the arctic air in our direction. The average speed for the day so far
is 14mph. Our peak gust is 31mph, occurring at 4:44am and again at
6:32am.
Visibility was initially hindered by some thin fog as the storm departed,
but with clearing skies and dry air views are currently up to 70 miles.
The maximum temperature for today is 27F degrees, which is 7 degrees
below the normal high of 34F. The minimum temperature since midnight
is 13F degrees, which is 5 degrees below the normal low of 18F.
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Today’s Observations:
7 A.M.
Weather: Scattered altocumulus, few stratocumulus distant NNE-SE-SW,
few nimbostratus distant N-E-S, virga distant NNE-SE
Temperature: 14F; Dew Point: 13F; Relative Humidity: 95%
Wind: NW @ 15G22 kts, peak wind NW 31mph @ 6:32am
Sea-level pressure: 1012.8 mb; 29.91 in. Hg: rising, then more rapidly
Visibility: 30 miles, thin fog all quadrants
6-hr Max temp: 25F
6-hr Min temp: 14F
24-hr Precip: 0.59 inches
24-hr Snowfall: 5.7 inches
Snow Depth: 6 inches
BHO SA 1155 100 SCT 30 128/14/13/3115G22/991/ FEW SC DSNT NNE-SE-SW
FEW NS DSNT N-E-S VIRGA DSNT NNE-SE THN F ALQDS PK WND 3127/32/
TOTAL NEW SNW PST 24 HRS 5.7 INS/ 8/570 4/006 53055 70059 10025 20014
10 A.M.
Weather: Clear, few stratocumulus distant NNE-SSE
Temperature: 18F; Dew Point: 12F; Relative Humidity: 76%
Wind: NW @ 14G23 kts
Sea-level pressure: 1017.9 mb; 30.06 in. Hg: rising steadily
Visibility: 60 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 60 179/18/12/3214G23/006/ FEW SC DSNT NNE-SSE/ 8/500 52051
1 P.M.
Weather: Clear, few stratocumulus all quadrants,
few altocumulus distant ESE-S-WNW
Temperature: 22F; Dew Point: 13F; Relative Humidity: 67%
Wind: WNW @ 14G24 kts
Sea-level pressure: 1019.1 mb; 30.09 in. Hg: rising, then steady
Visibility: 70 miles
6-hr Max temp: 22F
6-hr Min temp: 13F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 5 inches
BHO SA 1755 CLR 70 191/22/13/3014G24/009/ FEW SC ALQDS FEW AC DSNT ESE-S-WNW/
8/550 4/005 51012 10023 20013
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SUMMARY FOR SUNDAY, JANUARY 19, 2025
TEMPERATURE (DEGREES F)
MAX…….43 NORMAL…..34
MIN…….27 NORMAL…..18
MEAN……35 NORMAL…..26
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………..+9
TOTAL DEPARTURE FOR THE MONTH…………………….+10 [+0.3 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY……………30 DEPARTURE……..-9
TOTAL HEATING UNITS FOR THE MONTH…………..712 DEPARTURE…….-11
TOTAL HEATING UNITS FOR THE SEASON…………2644 DEPARTURE……-289
TOTAL HEATING UNITS LAST SEASON TO DATE…….2548 DEPARTURE…….+96
PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all on Main Tower.
E=Estimated
F420C (Official)………..26 N @ 08:44 P.M.
VECTOR #1 (1-Sec)……….28 NNW @ 08:15 P.M.
VECTOR #2 (1-Sec)……….29 NNW @ 08:15 P.M.
DAVIS #1……………….26 N @ 08:15 P.M.
DAVIS #2 ………………24 N @ 08:15 P.M.
RMY #1 (Instantaneous)…..29 N @ 08:45 P.M.
RMY #2 (Instantaneous)…..28 NNW @ 10:18 P.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)…..OTS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 NNW @ 08:08 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..19 @ 08:45 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..19 @ 10:18 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………18 N @ 08:45 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………17 N @ 10:20 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 N @ 08:45 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..19 NNW @ 10:20 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………9.8 NW [234 total miles]
VECTOR #1……………….9.9
VECTOR #2………………10.6
DAVIS #1……………….10.3 NNW
DAVIS #2……………….10.2 N
RMY #1…………………10.0 NNW
RMY #2…………………10.5 NNW
RICHARDS (C5C)…………..OTS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.59 DEPARTURE…..+0.45
TOTAL PRECIPITATION FOR THE MONTH…………..1.52 DEPARTURE…..-1.32
TOTAL PRECIPITATION FOR THE YEAR (2025)……..1.52 DEPARTURE…..-1.32
SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..5.7 DEPARTURE……+5.1
TOTAL SNOWFALL FOR THE MONTH………………..7.4 DEPARTURE……-3.5
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……20.0 DEPARTURE……-6.0
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PRELIMINARY CLIMATE SUMMARY FOR JANUARY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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
1/1 47/36/42/+13/0.55/0.0/000/00 44 W VEC1 45 W RMY 44
1/2 42/31/37/+9/T/T/534/97 60 W VEC1 60 WNW RMY 63
1/3 36/26/31/+3/0.00/0.0/446/81 48 W VEC1 48 W RMY 51
1/4 29/22/26/-2/0.00/0.0/453/82 43 NW VEC1 43 NW RMY 48
1/5 32/18/25/-3/0.00/0.0/088/16 39 WNW VEC1 39 WNW RMY 40
1/6 23/15/19/-9/0.00/0.0/000/00 31 NNW VEC1 31 NNW RMY 31
1/7 24/11/18/-9/T/T/450/81 43 WNW VEC1 42 WNW RMY 47
1/8 27/14/21/-6/0.00/0.0/550/99 48 WNW VEC1 48 WNW RMY 52
1/9 25/13/19/-8/T/T/223/40 46 NW VEC1 47 NW RMY 51
1/10 40/19/30/+3/0.00/0.0/560/100 39 NW VEC1 39 NW RMY 42
1/11 30/21/26/-1/0.12/1.7/000/00 25 NW VEC1 26 NW RMY 28
1/12 36/19/28/+1/0.00/0.0/556/99 35 NNW VEC1 35 NNW RMY 39
1/13 39/26/33/+7/0.00/0.0/192/34 26 WNW VEC1 27 WNW RMY 27
1/14 32/20/26/0/0.00/0.0/537/95 44 WNW VEC1 44 WNW RMY 45
1/15 29/16/23/-3/0.00/0.0/504/89 37 NW VEC1 37 NW RMY 38
1/16 30/13/22/-4/T/T/…/.. 20 W VEC1 20 SSW RMY 20
1/17 35/16/26/0/T/T/…/.. 20 S VEC1 20 SSW RMY 20
1/18 44/27/36/+10/0.26/0.0/…/.. 36 S VEC1 37 S RMY 39
1/19 43/27/35/+9/…./…/…/.. 26 N VEC1 28 NNW RMY 29
1/20 The low since midnight is 13F, the daily normal low is 18F.
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JANUARY 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 JANUARY 20
HIGH 59F IN 1951
LOW -9F IN 1901
PRECIP 1.95 INS. IN 1978
SNOWFALL 19.0 INS. IN 1978
PEAK GUST 76e MPH NE IN 1978
RECORDS FOR JANUARY 21
HIGH 65F IN 1906
LOW -4F IN 1888
PRECIP 2.49 INS. IN 1979
SNOWFALL 9.0 INS. IN 2014
PEAK GUST 78e MPH SE IN 1979
TODAY’S REPORT PREPARED BY: Joshua Polen
