Wednesday, May 7, 2025

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

WEDNESDAY, MAY 7, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0431E
SUNSET:  1851E

EARLY MORNING FOG LIFTS, SUNSHINE LEADS TO MORE CLOUDS AND A FEW
SHOWERS….

We started the day in the clouds once again, but the low clouds
and fog burned off pretty quickly yielding us with partial sunshine
for a time during the mid to late morning hours. However, surface
heating from the sun has helped convective clouds to develop, giving
us more clouds than sun during the afternoon so far. A few showers
have popped up in the vicinity of Blue Hill since the 1pm
observation, but nothing so far has reached the summit.

Temperatures warmed nicely into the low 70s by early this afternoon,
but has since slipped back to the upper 60s following the 1pm
observation due to an abundance of cloud cover at this time. The
dew point has dropped a bit as mixing takes place from aloft with
values slipping from the mid 50s to the low 50s.

Winds were on the lighter side during the morning, but have since
increased due to the mixing from aloft early this afternoon. A
generally south-southwesterly flow has been averaging at around
12mph for the day so far, despite the period of light wind this
morning. Gusts have been reaching 30mph or higher since around
noon time, with a peak gust so far of 33mph occurring at 12:40pm.

Visibility has improved quite a bit from the low values of early
this morning, reaching up to 40 miles by early this afternoon.

The maximum temperature for today is 72F degrees, which is 7 degrees
above the normal high of 65F. The minimum temperature since midnight
is 54F degrees, which is 8 degrees above the normal low of 46F.

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Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200ft, sun dimly visible
Temperature: 55F; Dew Point: 55F; Relative Humidity: 100%
Wind: S @ 6 kts, wind light
Sea-level pressure: 1016.4 mb; 30.01 in. Hg: rising, then more slowly
Visibility: 5 miles, fog
6-hr Max temp: 58F
6-hr Min temp: 54F
24-hr Precip:  0.52 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 X W2 5F 164/55/55/1806/001/ SUN DMLY VSBL WND LGT/
8//// 51008 6000/ 70052 10058 20054

10 A.M.
Weather: Broken altocumulus, broken cirrus, few stratocumulus all
quadrants, few moderate cumulus distant W-NW, few cumulus distant
SW-NW-NNE
Temperature: 67F; Dew Point: 55F; Relative Humidity: 66%
Wind: SW @ 9 kts
Sea-level pressure: 1016.5 mb; 30.02 in. Hg: rising, then falling
Visibility: 30 miles, hazy
3-hr Precip:  0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 E95 BKN 250 BKN 30 165/67/55/2209/002/ FEW SC ALQDS
FEW MDT CU DSNT W-NW FEW CU DSNT SW-NW-NNE HAZY/ 8/852 50001

1 P.M.
Weather: Broken cumulus, broken altocumulus, broken cirrus,
few lower cumulus fractus all quadrants, virga distant NNW
Temperature: 71F Dew Point: 52F; Relative Humidity: 50%
Wind: SSW @ 15G26 kts, peak wind SSW 33mph at 12:40 P.M.
Sea-level pressure: 1014.1 mb; 29.95 in. Hg: falling, then more rapidly
Visibility: 40 miles, hazy
6-hr Max temp: 72F
6-hr Min temp: 55F
6-hr Precip:  0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E50 BKN 65 BKN 250 BKN 40 141/71/52/2115G26/995/
FEW LWR CUFRA ALQDS VIRGA DSNT NNW HAZY PK WND 2029/40/ 8/262
58024 10072 20055

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SUMMARY FOR TUESDAY, MAY 6, 2025

TEMPERATURE (DEGREES F)
MAX…….61   NORMAL…..64
MIN…….48   NORMAL…..45
MEAN……55   NORMAL…..55

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……………..0
TOTAL DEPARTURE FOR THE MONTH………………………+30 [+4.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….10  DEPARTURE……..-1
TOTAL HEATING UNITS FOR THE MONTH…………….39  DEPARTURE…….-29
TOTAL HEATING UNITS FOR THE SEASON………….5437  DEPARTURE……-518
TOTAL HEATING UNITS LAST SEASON TO DATE……..5233  DEPARTURE……+204

COOLING DEGREE DAYS (SEASON JAN 2025 THRU DEC 2025)
TOTAL COOLING UNITS FOR YESTERDAY……………..0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH……………..4  DEPARTURE……..+2
TOTAL COOLING UNITS FOR THE SEASON…………….7  DEPARTURE……..+2
TOTAL COOLING UNITS LAST SEASON TO DATE………..0  DEPARTURE……..+7

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 S    @   10:14 P.M.
VECTOR #1 (1-Sec)……….27 ENE  @   01:57 A.M.
VECTOR #2 (1-Sec)……….27 NE   @   01:57 A.M.
DAVIS #1……………….25 ENE  @   01:56 A.M.
DAVIS #2 ………………33 S    @   10:15 P.M.
RMY #1 (Instantaneous)…..27 ENE  @   01:57 A.M.
RMY #2 (Instantaneous)…..28 S    @   10:14 P.M.
MERLIN………………….M
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………21 ENE  @   01:34 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..18      @   01:58 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..20      @   10:16 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 E    @   03:29 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………24 S    @   10:16 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..18 S    @   10:14 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..21 S    @   10:16 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..10.8 ESE [260 total miles] VECTOR #1………………10.8
VECTOR #2………………11.8
DAVIS #1……………….11.1 ESE
DAVIS #2……………….11.8 ESE
RMY #1…………………10.9 ESE
RMY #2…………………11.8 ESE
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.52 DEPARTURE…..+0.39
TOTAL PRECIPITATION FOR THE MONTH…………..1.23 DEPARTURE…..+0.47
TOTAL PRECIPITATION FOR THE YEAR (2025)…….15.35 DEPARTURE…..-4.19

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE MONTH………………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE SEASON (2024-2025)……35.8 DEPARTURE…..-33.9

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PRELIMINARY CLIMATE SUMMARY FOR MAY 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

5/1   69/43/56/+3/0.00/0.0/…/..        28 S   VEC1 28 SSW RMY 28
5/2   79/47/63/+9/0.19/0.0/…/..        28 SE  VEC1 29 SE  RMY 25 TSTM
5/3   84/54/69/+15/0.15/0.0/…/..       43 SSW VEC1 42 SSW RMY 44 TSTM
5/4   77/50/64/+10/0.06/0.0/…/..       33 SW  VEC1 34 SW  RMY 32
5/5   50/46/48/-7/0.26/0.0/…/..        35 ENE VEC1 35 ENE RMY 36
5/6   61/48/55/0/0.57/0.0/…/..         26 S   VEC1 27 ENE RMY 27

5/7 The low since midnight is 54F, the daily normal low is 46F.

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MAY 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 MAY 7
HIGH 93F IN 1930
LOW 33F IN 1970
PRECIP 1.19 INCHES IN 2005
SNOWFALL TRACE IN 1967
PEAK GUST 66e MPH WNW IN 1940

RECORDS FOR MAY 8
HIGH 89F IN 2000
LOW 29F IN 1956
PRECIP 1.48 INCHES IN 1886
SNOWFALL TRACE IN 1898, 1947
PEAK GUST 68e MPH NNW IN 1943

TODAY’S REPORT PREPARED BY: MFD