Tuesday, March 18, 2025

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

TUESDAY, MARCH 18, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0550E
SUNSET:  1754E

MUCH COOLER AND DRIER TODAY FOLLOWING THE BIG RAIN EVENT….

Today is a much different story than the past couple of days.
Temperatures are a solid 20 degrees cooler on average along with
much drier conditions compared to yesterday. Clouds are finding it
tough to move out as the frontal system has pretty much stalled
offshore, however we have been able to get a bit of filtered
sunshine today.

Speaking of yesterday, we set a new record for precipitation with
2.12″ of rain falling for the calendar day. This beat the old
record of 1.97″ set in 1968.

Temperatures bottomed out in the mid 30s early this morning, only
recovering to the mid to upper 40s early this afternoon. At least
these values are more seasonable for this time of year. The dew
point has been hanging in the 20s today, which is a far departure
from readings that were in the mid to upper 50s on Sunday and
yesterday. The air mass is much drier today which is allowing for
excellent visibility.

The wind shifted to the north-northwest late yesterday afternoon,
and was generally out of a northerly direction through this morning.
However, as we push into the early afternoon hours, the wind has
become more onshore. Winds were gusty overnight, but had been
gradually trending lighter through the morning. Now, it’s starting
to pick up a bit again early this afternoon. The average speed for
the day so far is around 13mph. As mentioned, it was quite gusty
during the early hours of the day with the peak occurring just
after 3am with a value of 31mph.

As mentioned above, the visibility is excellent today, with the
view of around 80s miles all morning, dropping a bit to around
70 miles early this afternoon.

The maximum temperature for today is 48F degrees, which is 4 degrees
above the normal high of 44F. The minimum temperature since midnight
is 34F degrees, which is 7 degrees above the normal low of 27F.

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Today’s Observations:

7 A.M.
Weather: Overcast altostratus, breaks in overcast distant SSW-W-N,
higher clouds visible distant WNW-N
Temperature: 36F; Dew Point: 27F; Relative Humidity: 69%
Wind: N @ 8G16 kts
Sea-level pressure: 1017.3 mb; 30.04 in. Hg: rising, then more rapidly
Visibility: 80 miles
6-hr Max temp: 38F
6-hr Min temp: 34F
24-hr Precip:  0.49 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 E70 OVC 80 173/36/27/3508G16/004/ BINOVC DSNT SSW-W-N
HIER CLDS VSBL DSNT WNW-N/ 8/02/ 53023 70049 10038 20034

10 A.M.
Weather: Broken cirrus, few altostratus distant NE-SSE
Temperature: 43F; Dew Point: 28F; Relative Humidity: 55%
Wind: N @ 13G22 kts
Sea-level pressure: 1018.2 mb; 30.07 in. Hg: rising, then steady
Visibility: 80 miles
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E230 BKN 80 182/43/28/0113G22/007/ FEW AS DSNT NE-SSE/
8/022 51009

1 P.M.
Weather: Broken cirrus, few altocumulus/altostratus distant NE-SE-S
Temperature: 47F; Dew Point: 23F; Relative Humidity: 38%
Wind: ENE @ 9G16 kts
Sea-level pressure: 1017.6 mb; 30.05 in. Hg: rising, then falling
Visibility: 70 miles
6-hr Max temp: 48F
6-hr Min temp: 36F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E230 BKN 70 176/47/23/0709G16/005/ FEW AC/AS DSNT NE-SE-S/
8/072 58006 10048 20036

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SUMMARY FOR MONDAY, MARCH 17, 2025

TEMPERATURE (DEGREES F)
MAX…….58   NORMAL…..44
MIN…….38   NORMAL…..27
MEAN……48   NORMAL…..36

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………….+12
TOTAL DEPARTURE FOR THE MONTH……………………+111 [+6.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….17  DEPARTURE…….-12
TOTAL HEATING UNITS FOR THE MONTH……………426  DEPARTURE……-112
TOTAL HEATING UNITS FOR THE SEASON………….4607  DEPARTURE……-363
TOTAL HEATING UNITS LAST SEASON TO DATE……..4277  DEPARTURE……+330

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)………..60 SSW  @   12:12 A.M.
VECTOR #1 (1-Sec)……….60 SSW  @   12:12 A.M.
VECTOR #2 (1-Sec)……….57 SSW  @   12:11 A.M.
DAVIS #1……………….64 S    @   12:12 A.M.
DAVIS #2 ………………65 S    @   01:24 A.M.
RMY #1 (Instantaneous)…..60 SSW  @   12:12 A.M.
RMY #2 (Instantaneous)…..62 SSW  @   12:11 A.M.
MERLIN…………………56 SSW
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………42 SSW  @   12:13 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..42      @   12:14 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..43      @   12:13 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………42 S    @   12:14 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………45 S    @   12:13 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..41 SSW  @   12:14 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..44 SSW  @   12:13 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..14.9 SSW [357 total miles] VECTOR #1………………14.8
VECTOR #2………………15.2
DAVIS #1……………….14.7 SW
DAVIS #2……………….15.1 SW
RMY #1…………………14.5 SW
RMY #2…………………15.1 SW
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.49 DEPARTURE…..+0.30
TOTAL PRECIPITATION FOR THE MONTH…………..3.35 DEPARTURE…..+0.38
TOTAL PRECIPITATION FOR THE YEAR (2025)……..9.00 DEPARTURE…..-2.47

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……-0.5
TOTAL SNOWFALL FOR THE MONTH………………TRACE DEPARTURE……-9.8
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……34.1 DEPARTURE…..-27.6

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PRELIMINARY CLIMATE SUMMARY FOR MARCH 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

3/1    50/21/36/+5/T/T/081/12            46 NW  VEC1 46 NW  RMY 49
3/2    28/14/21/-11/0.00/0.0/672/99      41 NW  VEC1 42 NW  RMY 43
3/3    31/8/20/-12/0.00/0.0/667/98       28 NW  VEC1 28 NW  RMY 31
3/4    48/23/36/+4/0.00/0.0/390/57       41 SW  VEC1 42 SW  RMY 43
3/5    54/41/48/+16/0.52/0.0/021/03      50 SSW VEC1 50 SSW RMY 55
3/6    55/32/44/+11/0.66/T/014/02        69 S   VEC1 69 S   RMY 68
3/7    41/25/33/0/T/T/638/92             60 WNW VEC1 61 WNW RMY 64
3/8    40/27/34/+1/0.00/0.0/619/89       55 W   VEC1 55 W   RMY 58
3/9    45/25/35/+2/0.00/0.0/544/78       40 W   VEC1 39 W   RMY 42
3/10   60/33/47/+13/0.00/0.0/680/97      38 WNW VEC1 38 WNW RMY 39
3/11   62/37/50/+16/0.00/0.0/676/96      39 SSW VEC1 40 SSW RMY 40
3/12   48/32/40/+6/T/T/544/77            29 N   VEC1 29 N   RMY 29
3/13   46/32/39/+5/0.00/0.0/483/68       25 ESE VEC1 26 ESE RMY 25
3/14   54/33/44/+9/0.00/0.0/570/80       22 SSW VEC1 22 SSW RMY 22
3/15   59/37/48/+13/0.00/0.0/358/50      28 S   VEC1 28 S   RMY 28
3/16   67/44/56/+21/0.05/0.0/136/19      56 SSW VEC1 58 SSW RMY 58
3/17   58/38/48/+12/2.12/0.0/000/00      60 SSW VEC1 60 SSW RMY 60

3/18 The low since midnight is 34F, the daily normal low is 27F.

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MARCH DAILY RECORDS TO DATE

3/16 RECORD HIGH MINIMUM TEMP OF 44F;
OLD RECORD WAS 43F IN 1921, 1973

3/17 RECORD PRECIPITATION AMOUNT OF 2.12 INS;
OLD RECORD WAS 1.97 INS IN 1968

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

RECORDS FOR MARCH 18
HIGH 73 IN 2022
LOW 0 IN 1885
PRECIP 5.61 INS. IN 1968 [RECORD FOR MONTH] SNOWFALL 9.3 INS. IN 1985
PEAK GUST 71e MPH WNW IN 1941

RECORDS FOR MARCH 19
HIGH 77 IN 2012
LOW -2 IN 1967
PRECIP 1.69 INS. IN 1956
SNOWFALL 17.6 INS. IN 1956
PEAK GUST 75e MPH WNW IN 1941

TODAY’S REPORT PREPARED BY: Matt Douglas