Tuesday, May 6, 2025

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

TUESDAY, MAY 6, 2025
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0433E
SUNSET:  1850E

OVERCAST SKIES AND DENSE FOG WITH OFF AND ON SHOWERS ONCE AGAIN TODAY….

Today is featuring another day of overcast skies and dense fog (the
summit is in the clouds). Off and on rain showers have been occurring
as well pretty much since yesterday. 0.10″ of rain was measured
through 7am this morning, with an additional 0.24″ measured through
1pm.

Temperatures rose for a time this morning, reaching the upper 50s
before the backdoor boundary slipped back to the south, turning the
wind to northeast, and dropping the temperature back to the lower 50s.
The front has once again pushed back to the north just before the
1pm observation with the temperature jumping back up to around 60F.

Winds have been bouncing between northeast and southeast depending
on where we are in relation to the backdoor boundary. The speed has
been fairly steady however, averaging at around 12mph for the day
so far. The peak gust, at least so far, occurred just before 2am
this morning with a value of 26mph.

Visibility has been quite poor as one would expect being in the
aforementioned dense fog. Much like yesterday, the view has generally
been 1/4th of a mile or less most of the day.

The maximum temperature for today is 60F degrees, which is 4 degrees
below the normal high of 64F. The minimum temperature since midnight
is 48F degrees, which is 3 degrees above the normal low of 45F.

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Today’s Observations:

7 A.M.
Weather: Sky obscured, vertical visibility 200ft
Temperature: 57F; Dew Point: 57F; Relative Humidity: 100%
Wind: ESE @ 8G14 kts
Sea-level pressure: 1024.8 mb; 30.26 in. Hg: rising, then falling
Visibility: 1/8th mile, fog
6-hr Max temp: 57F
6-hr Min temp: 48F
24-hr Precip:  0.10 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 X W2 1/8F 248/57/57/1208G14/026/ 8//// 50000 6005/ 70010
10057 20048

10 A.M.
Weather: Sky partially obscured, overcast stratocumulus,
light rain showers
Temperature: 53F; Dew Point: 53F; Relative Humidity: 100%
Wind: NE @ 9 kts
Sea-level pressure: 1023.6 mb; 30.23 in. Hg: falling, then more rapidly
Visibility: 1/16th mile, fog
3-hr Precip:  0.02 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 -X E14 OVC 1/16RW-F 236/53/53/0509/023/ RW-B14E19B33/
8/5// 58012 6002/

1 P.M.
Weather: Sky obscured, vertical visibility 200ft, light rain showers
Temperature: 60F Dew Point: 60F; Relative Humidity: 100%
Wind: ESE @ 9 kts
Sea-level pressure: 1021.3 mb; 30.16 in. Hg: falling, then more slowly
Visibility: 1/4th mile, fog
6-hr Max temp: 60F
6-hr Min temp: 52F
6-hr Precip:  0.24 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 X W2 1/4RW-F 213/60/60/1209/016/ 8//// 56023 6024/
10060 20052

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SUMMARY FOR MONDAY, MAY 5, 2025

TEMPERATURE (DEGREES F)
MAX…….50   NORMAL…..64
MIN…….46   NORMAL…..45
MEAN……48   NORMAL…..55

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………….-7
TOTAL DEPARTURE FOR THE MONTH………………………+30 [+5.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….17  DEPARTURE……..+6
TOTAL HEATING UNITS FOR THE MONTH…………….29  DEPARTURE…….-28
TOTAL HEATING UNITS FOR THE SEASON………….5427  DEPARTURE……-517
TOTAL HEATING UNITS LAST SEASON TO DATE……..5229  DEPARTURE……+198

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)………..35 ENE  @   12:27 P.M.
VECTOR #1 (1-Sec)……….35 ENE  @   12:27 P.M.
VECTOR #2 (1-Sec)……….35 ENE  @   12:57 P.M.
DAVIS #1……………….33 NE   @   01:51 P.M.
DAVIS #2 ………………31 ENE  @   07:47 A.M.
RMY #1 (Instantaneous)…..36 ENE  @   12:26 P.M.
RMY #2 (Instantaneous)…..35 ENE  @   12:57 P.M.
MERLIN…………………31 ENE
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………27 NE   @   07:56 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..23      @   07:56 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..23      @   12:58 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………23 NE   @   07:48 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………22 ENE  @   07:55 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 NE   @   07:56 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..22 ENE  @   12:58 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..14.4 ENE [345 total miles] VECTOR #1………………13.8
VECTOR #2………………14.6
DAVIS #1……………….14.7 ENE
DAVIS #2……………….14.7 ENE
RMY #1…………………13.5 NE
RMY #2…………………14.3 NE
RICHARDS (C5C)…………..OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.10 DEPARTURE…..-0.03
TOTAL PRECIPITATION FOR THE MONTH…………..0.71 DEPARTURE…..+0.08
TOTAL PRECIPITATION FOR THE YEAR (2025)…….14.83 DEPARTURE…..-4.58

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 The low since midnight is 48F, the daily normal low is 45F.

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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 6
HIGH 90F IN 1930
LOW 29F IN 1891
PRECIP 1.04 INCHES IN 1890
SNOWFALL TRACE IN 1917, 1952, 1996
PEAK GUST 65 MPH SSE IN 1989

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

TODAY’S REPORT PREPARED BY: MFD