Saturday, April 20, 2024

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

SATURDAY, APRIL 20, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0455E
SUNSET:  1832E

MORNING RAIN WITH LINGERING CLOUDINESS….

We began the morning in the clouds with some light drizzle,
becoming rain very shortly after the 7am observation. The intensity
was moderate for a short time, but light rain lasted through the 10am
observation, and came to an end not long after that. For the day today,
we have picked up 0.30″ in the gauge.

Temperatures were slow to climb this morning due to the cloud cover
and precipitation, rising only slightly from the mid 40s to the upper 40s
by noontime. Since then, we have made it into the mid 50s.

Winds have been quite light, averaging only 9mph to this point. The peak
gust so far is only about 22mph, taking place around 1:30am.

Visibility was poor this morning, limited to 1/16 of a mile. By the
afternoon, the cloud base began to lift, and views improved to 40 miles.

The maximum temperature so far today is 54F degrees, which is
5 degrees below the normal high of 59F. The minimum temperature
since midnight is 44F degrees, which is 4 degrees above the
normal low of 40F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Light drizzle and fog, sky obscured, vertical visibility 200ft
Temperature: 45F; Dew Point: 45F; Relative Humidity: 100%
Wind: SSW @ 7 kts
Sea-level pressure: 1014.8 mb; 29.97 in. Hg: rising, then falling
Visibility: 1/16 mile, fog
6-hr Max temp: 45F
6-hr Min temp: 44F
24-hr Precip:  0.01 inches
24-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1155 X W2 1/16L-F 148/45/45/2107/997/ 8//// 58005 70001 10045 20044

10 A.M.
Weather: Light rain and fog, sky obscured, vertical visibility 200ft
Temperature: 47F; Dew Point: 47F; Relative Humidity: 100%
Wind: SW @ 5 kts, wind light
Sea-level pressure: 1013.3 mb; 29.92 in. Hg: falling, then more rapidly
Visibility: 1/4 mile, fog
3-hr Precip:  0.28 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 X W2 1/4R-F 133/47/47/2205/992/ WND LGT/ 8//// 58015 6028/

1 P.M.
Weather: Broken stratocumulus, overcast altocumulus,
few breaks in overcast all quadrants
Temperature: 53F; Dew Point: 51F; Relative Humidity: 94%
Wind: SW @ 6 kts, wind light
Sea-level pressure: 1011.3 mb; 29.86 in. Hg: falling, then more slowly
Visibility: 40 miles, thin fog all quadrants
6-hr Max temp: 54F
6-hr Min temp: 45F
6-hr Precip:  0.29 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 0 inches
BHO SA 1755 E6 BKN 100 OVC 40 113/53/51/2306/986/ FEW BINOVC ALQDS
THN F ALQDS WND LGT/ 8/55/ 56020 6029/ 10054 20045

————————————————————–

SUMMARY FOR FRIDAY, APRIL 19, 2024

TEMPERATURE (DEGREES F)
MAX…….60   NORMAL…..58
MIN…….41   NORMAL…..39
MEAN……51   NORMAL…..49

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………….+2
TOTAL DEPARTURE FOR THE MONTH……………………+41 [+2.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY……………14  DEPARTURE……..-2
TOTAL HEATING UNITS FOR THE MONTH…………..353  DEPARTURE…….-32
TOTAL HEATING UNITS FOR THE SEASON…………4994  DEPARTURE……-738
TOTAL HEATING UNITS LAST SEASON TO DATE…….4808  DEPARTURE……+186

PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all Main Tower.
E=Estimated

F420C (Official)……….E29 S    @  05:39 P.M.
VECTOR #1 (1-Sec)……….29 S    @  05:39 P.M.
VECTOR #2 (1-Sec)……….28 SSE  @  04:38 P.M.
DAVIS #1……………….32 S    @  05:39 P.M.
DAVIS #2 ………………36 S    @  05:39 P.M.
RMY #1 (Instantaneous)…..29 S    @  05:39 P.M.
RMY #2 (Instantaneous)…..30 S    @  05:38 P.M.
MERLIN…………………27 S
RICHARDS (C5C) (Inst)……28      @  04:44 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………19 S    @  05:40 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..20      @  05:40 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..21      @  05:40 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………19 S    @  05:40 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 S    @  05:40 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..19 S    @  05:40 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..22 S    @  05:40 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………19      @  04:46 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….9.6 S  [231 total miles] VECTOR #1……………..9.8
VECTOR #2…………….10.5
DAVIS #1………………9.6 SSE
DAVIS #2……………..10.5 SSE
RMY #1………………..9.6 SSE
RMY #2……………….10.5 SE
RICHARDS (C5C)………..10.1

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.01 DEPARTURE…..-0.13
TOTAL PRECIPITATION FOR THE MONTH…………..3.89 DEPARTURE…..+0.73
TOTAL PRECIPITATION FOR THE YEAR (2024)…….23.94 DEPARTURE…..+6.76

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE MONTH………………..0.7 DEPARTURE……-1.8
TOTAL SNOWFALL FOR THE SEASON (2023-2024)……26.8 DEPARTURE…..-42.6

————————————————————–

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

4/1   56/40/48/+7/0.00/0.0/153/20         20 SSE VEC1 20 SSE RMY 19
4/2   47/35/41/0/0.07/0.0/115/15          25 E   VEC1 25 E   RMY 25
4/3   41/34/38/-4/1.10/T/000/00           53 E   VEC1 53 E   RMY 53
4/4   36/32/34/-8/1.25/0.7/000/00         63 ENE VEC1 64 ENE RMY 68
4/5   45/31/38/-5/0.01/T/147/19           33 WNW VEC1 31 WNW RMY 33
4/6   43/33/38/-5/0.08/093/12             35 N   VEC1 35 N   RMY 35
4/7   48/34/41/-3/T/0.0/094/12            32 N   VEC1 31 N   RMY 31
4/8   66/36/51/+7/0.00/0.0/636/81         23 WNW VEC1 23 WNW RMY 22
4/9   63/40/52/+8/0.00/0.0/741/94         22 ENE VEC1 21 ENE RMY 21
4/10  65/38/52/+7/T/0.0/348/44            26 S   VEC1 26 S   RMY 30
4/11  55/42/49/+4/0.04/0.0/000/00         32 SSE VEC1 32 SSE RMY 31
4/12  60/46/53/+7/1.03/0.0/032/04         62 SSE VEC1 62 S   RMY 63
4/13  54/43/49/+3/T/0.0/271/34            43 W   VEC1 42 WNW RMY 46
4/14  58/42/50/+3/0.09/0.0/384/48         33 WSW VEC1 33 WSW RMY 35
4/15  73/43/58/+11/T/0.0/764/95           33 NW  VEC1 33 NW  RMY 34
4/16  68/44/56/+9/0.00/0.0/759/94         29 NW  VEC1 28 NW  RMY 29
4/17  60/40/50/+2/0.00/0.0/656/81         25 ESE VEC1 24 ESE RMY 24
4/18  47/40/44/-4/0.21/0.0/…/..         25 E   VEC1 25 E   RMY 23
4/19  60/41/51/+2/…/0.0/…/..          29 S   VEC1 29 S   RMY 29

4/20 The low since midnight is 44F, the daily normal low is 40F.

————————————————————–

APRIL DAILY RECORDS TO DATE

NONE…

————————————————————–

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

RECORDS FOR APRIL 20
HIGH 88 IN 1927
LOW 18 IN 1897
PRECIP 1.14 IN 1972
SNOWFALL 2.5 IN. IN 1904, 1972
PEAK GUST 76 MPH WNW IN 1963

RECORDS FOR APRIL 21
HIGH 85 IN 1923
LOW 22 IN 1908
PRECIP 3.18 IN. IN 1991
SNOWFALL 0.8 IN. IN 1947
PEAK GUST 76e MPH NE IN 1940

TODAY’S REPORT PREPARED BY: Joshua Polen