Thursday, May 4, 2023

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

THURSDAY, MAY 4, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0436E
SUNSET:  1847E

OVERCAST, CHILLY, AND DAMP WITH PERIODS OF SHOWERS AND DRIZZLE…

Clouds have dominated the sky once again (I know, sounds like a
broken record) today with periods of light rain showers and
drizzle occurring into the mid afternoon hours. It’s been a
rather raw and chilly day with a brisk onshore wind at times.
The temperature has been stuck in the low to mid 40s all day,
which is some 20 degrees below normal for the date.

The wind has been onshore and brisk all morning, but has finally
diminished this afternoon. The average speed for the day has been
around 10mph, with gusts this morning were just under 30mph.

Visibility has been changeable today with the periods of showers
and drizzle moving through, dropping to as low as around 2 miles
at times, but averaging around 6-10 miles most of the morning
into early afternoon. It has improved to over 60 miles by late
this afternoon.

The high temperature so far today is 44F degrees, which is 20
degrees below the normal high of 64F. The low since midnight is
40F, which is 5 degrees below the normal low of 45F.

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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 stratocumulus, very light rain showers
Temperature: 41F; Dew Point: 41F; Relative Humidity: 100%
Wind: NE @ 9G20 kts
Sea-level pressure: 1010.2 mb; 29.83 in. Hg: rising, then more rapidly
Visibility: 6 miles, fog, 10 miles N-ENE, 4 miles S-SW
6-hr Max temp: 43F
6-hr Min temp: 40F
24-hr Precip:  0.04 ins.
BHO SA 1155 E12 OVC 6RW-F 102/41/41/0509G20/983/ PCPN VRY LGT
VSBY 10 N-ENE 4 S-SW/ 8/5// 53029 6003/ 70004 10043 20040

10 A.M.
Weather: Broken stratocumulus, overcast stratus, light drizzle
Temperature: 41F; Dew Point: 41F; Relative Humidity: 98%
Wind: NE @ 9G21 kts
Sea-level pressure: 1012.4 mb; 29.90 in. Hg: rising, then more rapidly
Visibility: 7 miles, thin fog, 10 miles NW-NNW, 5 miles ESE-SE
3-hr Precip:  0.02 ins.
BHO SA 1455 E6 BKN 14 OVC 7L- 124/41/41/0409G21/990/ THN F ALQDS
VSBY 10 NW-NNW 5 ESE-SE AND SW-WSW/ 8/6// 53022 6002/

1 P.M.
Weather: Sky obscured, vertical visibility 300ft, light drizzle
Temperature: 41F; Dew Point: 41F; Relative Humidity: 100%
Wind: NNE @ 8 kts
Sea-level pressure: 1013.9 mb; 29.94 in. Hg: rising steadily
Visibility: 2 miles, fog
6-hr Max temp: 44F
6-hr Min temp: 41F
6-hr Precip:  0.03 ins.
BHO SA 1755 X W3 2L-F 139/41/41/0308/994/ 8//// 52015 6003/
10044 20041

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SUMMARY FOR WEDNESDAY, MAY 3, 2023

TEMPERATURE (DEGREES F)
MAX…….55   NORMAL…..63
MIN…….42   NORMAL…..44
MEAN……49   NORMAL…..54

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………-5
TOTAL DEPARTURE FOR THE MONTH…………………-8 [-2.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2022 THRU JUN 2023)
TOTAL HEATING UNITS FOR YESTERDAY……………16  DEPARTURE……..+5
TOTAL HEATING UNITS FOR THE MONTH……………42  DEPARTURE……..+7
TOTAL HEATING UNITS FOR THE SEASON…………5013  DEPARTURE……-909
TOTAL HEATING UNITS LAST SEASON TO DATE…….5404  DEPARTURE……-391

COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE………0
TOTAL COOLING UNITS FOR THE MONTH…………….0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE SEASON……………9  DEPARTURE……..+5
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.
E=Estimated

F420C (Official)……….E25 E   @   11:14 P.M.
VECTOR #1 (1-Sec)……….25 E   @   10:44 P.M.
VECTOR #2 (1-Sec)……….24 E   @   11:13 P.M.
DAVIS #1……………….25 S   @   10:10 A.M.
DAVIS #2 ………………23 S   @   10:10 A.M.
RMY #1 (Instantaneous)…..25 E   @   11:14 P.M.
RMY #2 (Instantaneous)…..24 E   @   11:14 P.M.
MERLIN…………………27 SW
RICHARDS (C5C) (Inst)……24     @   11:14 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………18 E   @   11:21 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..16     @   10:46 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17     @   10:45 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………18 E   @   10:46 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………18 S   @   10:12 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..17 E   @   10:46 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 E   @   10:45 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………17     @   11:18 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……… 8.0 NE [191 total miles] VECTOR #1………………. 8.1
VECTOR #2………………. 8.5
DAVIS #1……………….. 8.2 E
DAVIS #2……………….. 8.2 E
RMY #1…………………. 8.1 E
RMY #2…………………. 8.4 E
RICHARDS (C5C)………….. 8.5

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.04 DEPARTURE…..-0.08
TOTAL PRECIPITATION FOR THE MONTH…………..0.30 DEPARTURE…..-0.07
TOTAL PRECIPITATION FOR THE YEAR…………..18.50 DEPARTURE…..-0.65

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 (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

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

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   63/45/54/+1/0.04/0.0/…/..         44 SSE  VEC1 46 SSE RMY 48
5/2   57/43/50/-4/0.22/0.0/…/..         33 S    VEC1 34 S   RMY 35
5/3   55/42/49/-5/0.01/0.0/…/..         25 E    VEC1 25 E   RMY 25

5/4 The low since midnight is 40, the daily normal low is 45F

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

RECORDS FOR MAY 4
HIGH 90F IN 2001
LOW 27F IN 1911 (RECORD FOR MAY)
PRECIP 1.67 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966

RECORDS FOR MAY 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976

TODAY’S REPORT PREPARED BY: Matt Douglas