Friday, April 11, 2025

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

FRIDAY, APRIL 11, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0509E
SUNSET:  1822E

MEASURABLE SNOW ON GREAT BLUE HILL THIS MORNING….

Well, April snow arrived on the hill early this morning. We received
a measurable amount, 1.0 inches! Maybe not enough to build a snowman,
but enough to put down in the books. And in typical springtime fashion,
all evidence has since melted. The liquid equivalent of the snow
measured to 0.28″. This still puts us in a deficit for snow but we are
above in liquid precipitation for the month at +0.13″.

Temperatures have struggled to rebound much today, though we have
made it to 43F by the final observation. During the snow event, we
hovered just around freezing, and then once the system moved to our
northeast the temperatures started to improve. It did start to feel
slightly cooler by late morning as the dew points dropped slightly and
the air dried a bit.

Winds were steady during the overnight, with an average of around
9mph. However, after the winds shifted to a more easterly flow, the
wind speed slowed considerably. The average speed for the day so far
is around 5mph. The peak gust thus far is 16mph, which occurred right
around 10:30am.

Visibility was heavily impacted by foggy and winter-like conditions
this morning, giving us about a 1/4 mile view. Fortunately, the fog
lifted and we had around 30 miles for the remainder of the day.

The maximum temperature for today is 43F degrees, which is 11 degrees
below the normal high of 54F. The minimum temperature since midnight
is 31F degrees, which is 5 degrees below the normal low of 36F.

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Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200ft
Temperature: 33F; Dew Point: 33F; Relative Humidity: 100%
Wind: E @ 7 kts
Sea-level pressure: 1024.9 mb; 30.27 in. Hg: falling, then rising
Visibility: 1/4 mile, fog
6-hr Max temp: 33F
6-hr Min temp: 31F
24-hr Precip:  0.28 inches
24-hr Snowfall: 1.0 inches
Snow Depth: 1 inch
BHO SA 1155 X W2 1/4F 249/33/33/0807/027/ ZL-E29 NEW SNW PST 24 HRS
1.0 INS/ 8//// 4/001 58001 6023/ 70028 10033 20031

10 A.M.
Weather: Overcast stratocumulus, few lower stratus fractus ENE-E-SE
Temperature: 39F; Dew Point: 38F; Relative Humidity: 98%
Wind: NE @ 4 kts, wind light
Sea-level pressure: 1025.5 mb; 30.28 in. Hg: rising, then more
rapidly
Visibility: 30 miles
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E30 OVC 30 255/39/38/0604/028/ FEW LWR STFRA ENE-E-SE
WND LGT/ 8/5// 53006

1 P.M.
Weather: Overcast stratocumulus, few stratocumulus NE-E-ESE
Temperature: 43F Dew Point: 40F; Relative Humidity: 82%
Wind: E @ 4 kts, wind light
Sea-level pressure: 1022.5 mb; 30.19 in. Hg: falling unsteadily
Visibility: 30 miles
6-hr Max temp: 43F
6-hr Min temp: 33F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E35 OVC 30 225/43/40/0804/019/ FEW SC NE-E-ESE WND LGT/
8/5// 57030 10043 20033

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SUMMARY FOR THURSDAY, APRIL 10, 2025

TEMPERATURE (DEGREES F)
MAX…….49   NORMAL…..54
MIN…….29   NORMAL…..36
MEAN……39   NORMAL…..45

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………..-6
TOTAL DEPARTURE FOR THE MONTH……………………..-12 [-1.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….26  DEPARTURE……..+6
TOTAL HEATING UNITS FOR THE MONTH……………233  DEPARTURE…….+11
TOTAL HEATING UNITS FOR THE SEASON………….5162  DEPARTURE……-407
TOTAL HEATING UNITS LAST SEASON TO DATE……..4858  DEPARTURE……+304

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)………..23 SSW  @   11:34 P.M.
VECTOR #1 (1-Sec)……….23 SSW  @   11:34 P.M.
VECTOR #2 (1-Sec)……….23 SSW  @   11:14 P.M.
DAVIS #1……………….25 S    @   11:36 P.M.
DAVIS #2 ………………27 S    @   08:53 P.M.
RMY #1 (Instantaneous)…..25 SSW  @   11:36 P.M.
RMY #2 (Instantaneous)…..24 SSW  @   11:46 P.M.
MERLIN…………………23 S
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………17 SSW  @   11:36 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..17      @   11:36 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17      @   11:36 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………17 S    @   08:53 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………19 S    @   08:53 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..17 SSW  @   11:36 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 S    @   09:46 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………8.6 SSW [206 total miles] VECTOR #1……………….9.0
VECTOR #2……………….9.3
DAVIS #1………………..8.9 SSE
DAVIS #2………………..9.4 SSE
RMY #1………………….8.7 E
RMY #2………………….9.2 ENE
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.28 DEPARTURE…..+0.10
TOTAL PRECIPITATION FOR THE MONTH…………..1.84 DEPARTURE…..+0.13
TOTAL PRECIPITATION FOR THE YEAR (2025)…….12.55 DEPARTURE…..-3.18

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..1.0 DEPARTURE……+0.8
TOTAL SNOWFALL FOR THE MONTH………………..1.1 DEPARTURE……-0.6
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……35.2 DEPARTURE…..-33.4

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PRELIMINARY CLIMATE SUMMARY FOR APRIL 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

4/1    55/32/44/+3/0.17/0.0/512/67       38 NW  VEC1 38 NW  RMY 40
4/2    42/27/35/-6/0.11/T/584/76         29 NNW VEC1 28 NNW RMY 29
4/3    62/32/47/+5/0.31/0.0/000/00       38 SW  VEC1 38 SW  RMY 39
4/4    69/47/58/+16/0.00/0.0/456/59      31 NW  VEC1 31 NW  RMY 30
4/5    47/36/42/-1/0.49/0.0/000/00       25 ESE VEC1 29 SE  RMY 25
4/6    51/37/44/+1/0.20/0.0/016/02       22 NNW VEC1 21 NNW RMY 21
4/7    45/34/40/-4/0.18/T/000/00         24 E   VEC1 23 NNE RMY 23
4/8    40/26/33/-11/0.10/0.1/196/25      51 W   VEC1 48 W   RMY 51
4/9    46/24/35/-9/0.00/0.0/755/96       36 WNW VEC1 33 NW  RMY 36
4/10   49/29/39/-6/0.01/0.0/…/..       23 SSW VEC1 23 SSW RMY 25

4/11 The low since midnight is 31F, the daily normal low is 36F.

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APRIL 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 APRIL 11
HIGH 85 IN 2017
LOW 19 IN 1909
PRECIP 1.72 IN. IN 2003
SNOWFALL 9.5 IN. IN 1958
PEAK GUST 65 MPH NW IN 1963

RECORDS FOR APRIL 12
HIGH 82 IN 1945
LOW 17 IN 1926
PRECIP 1.51 IN. IN 1993
SNOWFALL 9.0 IN. IN 1894
PEAK GUST 65e MPH W IN 1978

TODAY’S REPORT PREPARED BY: Amanda Joly