Monday, May 1, 2023

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

MONDAY, MAY 1, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0440E
SUNSET:  1844E

HEAVY RAIN OVERNIGHT CLEARS OUT EARLY THIS MORNING; PARTIAL
SUNSHINE AND WINDY FOR THE BALANCE OF THE DAY…

Rainfall, which was heavy at times overnight, cleared out early
this morning, but not before leaving 1.23″ of rain in the gauge.
Actually, going back to Saturday evening, the weekend rainfall
total was an impressive 1.94″!

Partial sunshine and windy conditions have been left in the wake
of the strong storm system that moved through. As a matter of
fact, our station pressure dropped to a low of 961.3mb (28.387in)
between 4-5am this morning, this translates to around 984.4mb
(29.069in) at sea-level.

Temperatures warmed overnight with readings reaching 61F degrees
around 1am. Values then dropped off a bit through the morning into
the mid 50s, before recovering again into the low 60s early this
afternoon.

The wind has been quite busy with an average speed for the day
thus far of around 18mph. The peak gust for the day occurred
just before 1am and it was 44mph!

Visibility has increased markedly from the early morning value
of only 12 miles. It reached 70 miles by late this morning,
where it has remained through the balance of the day.

The high temperature so far today is 62F degrees, which is 1
degree below the normal high of 63F. The low since midnight is
54F, which is 10 degrees above the normal low of 44F.

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PRELIMINARY STATS FOR APRIL 2023

TEMPERATURE, Deg. F
Avg. Max. 59.8 [+3.5] Avg. Min. 40.9 [+3.0] Mean      50.4 [+3.3] 24-hour corrected mean: 49.4
Max. for month: 88F on the 13th and 14th
Min. for month: 28F on the 3rd

HEATING DEGREE DAYS
Total heating units:    439 [-101] Total for the season:  4971 [-916] Total for last season: 5364

COOLING DEGREE DAYS
Total cooling units:      9 [+006] Total for the season:     9 [+006] Total for last season:    0

PRECIPITATION, Inches
Total: 3.59 [-1.17] Greatest in 24 hrs: 1.72 on the 30th

SNOWFALL, Inches
Total: 0.0 [-2.8] Greatest in 24 hrs: N/A

WIND, mph
Avg. uncorrected wind speed: 10.5 mph
Avg. corrected wind speed:   11.1 mph
Prevailing wind direction:   East-Northeast [13%] Peak gust and direction:  46 NW on the 12th

SUNSHINE:
Campbell-Stokes card minutes: 11598 of a possible 23250, or 50%
Astronomical total minutes: 12017 of a possible 24085, or 50%

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Today’s Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 55F; Dew Point: 55F; Relative Humidity: 99%
Wind: SSW @ 16G23 kts, peak wind S 31mph at 5:58 A.M.
Sea-level pressure: 985.8 mb; 29.11 in. Hg: rising, then more rapidly
Visibility: 12 miles, thin fog
6-hr Max temp: 60F
6-hr Min temp: 55F
24-hr Precip:  1.23 ins.
BHO SA 1155 E3 OVC 12 858/55/55/2016G23/911/ THN F ALQDS
L-E32 PK WND 1727/58/ 8/6// 53016 6002/ 70123 10060 20055

10 A.M.
Weather: Broken cumulus, broken altocumulus
Temperature: 55F; Dew Point: 43F; Relative Humidity: 64%
Wind: W @ 16G29 kts, peak wind WSW 35mph at 9:10 A.M.
Sea-level pressure: 991.1 mb; 29.27 in. Hg: rising, then more slowly
Visibility: 70 miles
3-hr Precip:  0.01 ins.
BHO SA 1455 E25 BKN 120 BKN 70 911/55/43/2716G29/927/
PK WND 2430/10/ 8/230 51053 6001/

1 P.M.
Weather: Broken cumulus
Temperature: 62F; Dew Point: 42F; Relative Humidity: 47%
Wind: WSW @ 11G18 kts
Sea-level pressure: 994.0 mb; 29.35 in. Hg: rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 62F
6-hr Min temp: 54F
6-hr Precip:  0.01 ins.
BHO SA 1755 E55 BKN 70 940/62/42/2411G18/935/ 8/200 51029
6001/ 10062 20054

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SUMMARY FOR SUNDAY, APRIL 30, 2023

TEMPERATURE (DEGREES F)
MAX…….57   NORMAL…..63
MIN…….46   NORMAL…..43
MEAN……52   NORMAL…..53

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………-1
TOTAL DEPARTURE FOR THE MONTH……………….+105 [+3.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2022 THRU JUN 2023)
TOTAL HEATING UNITS FOR YESTERDAY……………13  DEPARTURE……..+1
TOTAL HEATING UNITS FOR THE MONTH…………..439  DEPARTURE……-101
TOTAL HEATING UNITS FOR THE SEASON…………4971  DEPARTURE……-916
TOTAL HEATING UNITS LAST SEASON TO DATE…….5364  DEPARTURE……-393

COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH…………….9  DEPARTURE……..+6
TOTAL COOLING UNITS FOR THE SEASON……………9  DEPARTURE……..+6
TOTAL COOLING UNITS LAST SEASON TO DATE……….0  DEPARTURE……..+9

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

F420C (Official)……….E37 ESE @   11:07 P.M.
VECTOR #1 (1-Sec)……….39 ESE @   11:06 P.M.
VECTOR #2 (1-Sec)……….38 SE  @   11:20 P.M.
DAVIS #1……………….37 ESE @   11:06 P.M.
DAVIS #2 ………………37 SE  @   11:20 P.M.
RMY #1 (Instantaneous)…..38 ESE @   11:06 P.M.
RMY #2 (Instantaneous)…..39 ESE @   10:56 P.M.
MERLIN…………………M
RICHARDS (C5C) (Inst)……38     @   11:06 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………29 ESE @   11:12 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..26     @   11:10 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..25     @   11:08 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………27 ESE @   11:06 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………25 ESE @   11:09 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..25 ESE @   11:10 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..25 ESE @    9:47 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………25     @   11:07 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………14.8 ENE [356 total miles] VECTOR #1……………….13.9
VECTOR #2……………….14.9
DAVIS #1………………..15.0 E
DAVIS #2………………..15.1 E
RMY #1………………….14.1 E
RMY #2………………….14.7 E
RICHARDS (C5C)…………..14.5

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..1.23 DEPARTURE…..+1.09
TOTAL PRECIPITATION FOR THE MONTH…………..3.59 DEPARTURE…..-1.17
TOTAL PRECIPITATION FOR THE YEAR…………..18.23 DEPARTURE…..-0.55

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……-2.8
TOTAL SNOWFALL FOR THE SEASON (2022-2023)……34.9 DEPARTURE…..-34.8

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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   60/39/50/+9/0.39/0.0/145/19         36 SW   VEC1 40 SW  RMY 41
4/2   50/30/40/-1/0.00/0.0/636/83         40 NNW  VEC1 44 NNW RMY 45
4/3   51/28/40/-2/0.00/0.0/737/96         41 SSW  VEC1 46 SSW RMY 46
4/4   62/40/51/+9/0.00/0.0/594/77         26 ENE  VEC1 26 ENE RMY 27
4/5   45/37/41/-2/0.02/0.0/000/00         33 ENE  VEC1 34 ENE RMY 37
4/6   62/37/50/+7/0.02/0.0/155/20         26 NW   VEC1 28 NNW RMY 29
4/7   58/36/47/+3/0.00/0.0/328/42         45 WNW  VEC1 48 WNW RMY 52
4/8   50/29/40/-4/0.00/0.0/767/98         26 NNW  VEC1 29 NNW RMY 31
4/9   54/33/44/0/0.00/0.0/770/98          25 S    VEC1 28 S   RMY 28
4/10  65/33/49/+4/0.00/0.0/772/98         18 WSW  VEC1 19 NW  RMY 20
4/11  75/45/60/+15/0.00/0.0/522/66        37 W    VEC1 37 W   RMY 38
4/12  73/56/65/+19/0.00/0.0/515/65        46 NW   VEC1 49 NW  RMY 52
4/13  88/52/70/+24/0.00/0.0/764/96        25 W    VEC1 26 WNW RMY 27
4/14  88/50/69/+22/0.00/0.0/711/89        24 WNW  VEC1 27 WNW RMY 26
4/15  68/45/57/+10/T/0.0/401/50           20 ENE  VEC1 20 ENE RMY 21
4/16  55/46/51/+4/0.05/0.0/000/00         21 NE   VEC1 22 NE  RMY 21
4/17  55/45/50/+2/0.06/0.0/000/00         17 NE   VEC1 18 ENE RMY 18
4/18  57/45/51/+3/T/0.0/446/55            39 WSW  VEC1 41 WSW RMY 42
4/19  49/37/43/-6/0.00/0.0/244/30         35 WNW  VEC1 36 WNW RMY 40
4/20  64/36/50/+1/0.00/0.0/693/85         23 NW   VEC1 23 NNW RMY 23
4/21  55/42/49/-1/0.00/0.0/663/81         22 E    VEC1 24 SE  RMY 24
4/22  53/42/48/-2/0.27/0.0/000/00         28 ESE  VEC1 31 ESE RMY 30
4/23  51/45/48/-2/0.72/0.0/000/00         30 SE   VEC1 33 SE  RMY 31
4/24  58/43/51/0/0.00/0.0/339/41          21 WNW  VEC1 22 WNW RMY 22
4/25  61/42/52/+1/0.11/0.0/406/49         18 NNE  VEC1 21 NNE RMY 21
4/26  55/42/49/-3/T/0.0/332/40            20 NE   VEC1 21 E   RMY 22
4/27  59/42/51/-1/0.04/0.0/450/54         26 NW   VEC1 30 NW  RMY 30
4/28  62/41/52/0/0.00/0.0/619/74          20 ESE  VEC1 23 ESE RMY 22
4/29  55/44/50/-3/0.19/0.0/008/01         33 ESE  VEC1 34 ESE RMY 34
4/30  57/46/52/-1/1.72/0.0/000/00         37 ESE  VEC1 39 ESE RMY 38

5/1  The low since midnight is 54F, the daily normal low is 44F

DAILY RECORDS

04/12/2023: NEW RECORD HIGH MINIMUM TEMPERATURE OF 56F,
THIS BEATS THE OLD RECORD OF 52F SET IN 1945 AND 1947

04/13/2023: NEW RECORD HIGH MAXIMUM TEMPERATURE OF 88F,
THIS BEATS THE OLD RECORD OF 85F SET IN 1945

04/14/2023: NEW RECORD HIGH MAXIMUM TEMPERATURE OF 88F,
THIS BEATS THE OLD RECORD OF 80F SET IN 1945

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

RECORDS FOR MAY 1
HIGH 87F IN 1899
LOW 29F IN 1978
PRECIP 2.53 INCHES IN 1921
SNOWFALL TRACE IN 1905,1917,1921,1995,2016
PEAK GUST 57 MPH NW IN 1974

RECORDS FOR MAY 2
HIGH 92F IN 2001
LOW 29F IN 1903
PRECIP 1.36 INCHES IN 2006
SNOWFALL TRACE IN 1920, 1941
PEAK GUST 58 MPH S IN 1983

TODAY’S REPORT PREPARED BY: Matt Douglas