Wednesday, May 3, 2023

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

WEDNESDAY, MAY 3, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0437E
SUNSET:  1846E

MORE CLOUDS THAN SUN AGAIN TODAY WITH A FEW RAIN SHOWERS…

Clouds have dominated the sky today with a couple of short
duration periods of partial sun this morning. The sun has been
what we call self destructive, as is often the case when an
upper level low is over the region. Even the tiniest amount of
surface heating quickly gets the convective process going,
leading to clouds and eventually showers. A rain shower did
move across the hill late this morning. Some areas just to
the north of the hill reported some small hail.

Temperatures have been kept down today thanks to the cloud
cover and very cold air aloft. We have only warmed into the
low-mid 50s after a morning low in the low 40s.

The wind has been quite light today, only averaging around
6mph for the day thus far. Direction has been rather variable,
coming mostly out of the south-southwest early this morning,
then southeast mid to late morning, and now finally northeast
early this afternoon.

Visibility has been changeable today with the spokes of showers
moving through, dropping to as low as around 5 miles at times,
then rising again to as high as 60 miles.

The high temperature so far today is 53F degrees, which is 10
degrees below the normal high of 63F. The low since midnight is
42F, which is 2 degrees below 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: Broken altocumulus, broken altocumulus castellanus, broken
cirrus, few stratocumulus distant all quadrants
Temperature: 45F; Dew Point: 42F; Relative Humidity: 89%
Wind: ESE @ 3 kts, wind light
Sea-level pressure: 998.6 mb; 29.49 in. Hg: rising, then more slowly
Visibility: 60 miles
6-hr Max temp: 45F
6-hr Min temp: 42F
24-hr Precip:  0.20 ins.
BHO SA 1155 E75 BKN 120 BKN 250 BKN 60 986/45/42/1203/949/
FEW SC DSNT ALQDS THN K LYR ALNG HRZN ALQDS WND LGT/ 8/584
51014 70020 10045 20042

10 A.M.
Weather: Scattered cumulus, overcast nimbostratus, very light rain
shower, few breaks in overcast NW-NE
Temperature: 52F; Dew Point: 42F; Relative Humidity: 69%
Wind: S @ 4 kts, wind light and variable
Sea-level pressure: 1000.1 mb; 29.53 in. Hg: rising, then more slowly
Visibility: 60 miles, 4 miles SSW
3-hr Precip:  Trace
BHO SA 1455 55 SCT E85 OVC 60RW- 001/52/42/1704/953/ FEW BINOVC
NW-NE RW-B51 PCPN VRY LGT VSBY 4 SSW WND L/V/ 8/22/ 51015 6000/

1 P.M.
Weather: Scattered cumulus, broken altocumulus, few cumulus fractus
all quadrants, towering cumulus distant NW-NNE
Temperature: 53F; Dew Point: 41F; Relative Humidity: 63%
Wind: ENE @ 5 kts, wind light
Sea-level pressure: 1000.5 mb; 29.55 in. Hg: rising, then steady
Visibility: 60 miles
6-hr Max temp: 53F
6-hr Min temp: 45F
6-hr Precip:  0.01 ins.
BHO SA 1755 30 SCT E60 BKN 60 005/53/41/0605/955/ FEW CUFRA ALQDS
TCU DSNT NW-NNE WND LGT/ 8/260 51004 6001/ 10053 20045

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SUMMARY FOR TUESDAY, MAY 2, 2023

TEMPERATURE (DEGREES F)
MAX…….57   NORMAL…..63
MIN…….43   NORMAL…..44
MEAN……50   NORMAL…..54

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………-4
TOTAL DEPARTURE FOR THE MONTH…………………-3 [-1.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2022 THRU JUN 2023)
TOTAL HEATING UNITS FOR YESTERDAY……………15  DEPARTURE……..+3
TOTAL HEATING UNITS FOR THE MONTH……………26  DEPARTURE……..+2
TOTAL HEATING UNITS FOR THE SEASON…………4997  DEPARTURE……-914
TOTAL HEATING UNITS LAST SEASON TO DATE…….5389  DEPARTURE……-392

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)……….E33 S   @   12:12 P.M.
VECTOR #1 (1-Sec)……….34 S   @   12:12 P.M.
VECTOR #2 (1-Sec)……….34 SSE @   12:03 P.M.
DAVIS #1……………….34 S   @   11:23 A.M.
DAVIS #2 ………………45 S   @   12:06 P.M.
RMY #1 (Instantaneous)…..35 S   @   12:12 P.M.
RMY #2 (Instantaneous)…..36 SSE @   12:03 P.M.
MERLIN…………………32 S
RICHARDS (C5C) (Inst)……34     @   12:12 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………26 S   @   12:12 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..26     @   12:12 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..26     @   12:12 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………24 S   @   11:24 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………26 S   @   12:12 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..25 S   @   12:12 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..27 S   @   12:12 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………25     @   12:12 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………11.8 S [284 total miles] VECTOR #1……………….12.1
VECTOR #2……………….12.6
DAVIS #1………………..11.5 S
DAVIS #2………………..12.3 S
RMY #1………………….11.8 S
RMY #2………………….12.8 S
RICHARDS (C5C)…………..12.0

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.20 DEPARTURE…..+0.08
TOTAL PRECIPITATION FOR THE MONTH…………..0.26 DEPARTURE…..+0.01
TOTAL PRECIPITATION FOR THE YEAR…………..18.46 DEPARTURE…..-0.57

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 The low since midnight is 42, the daily normal low is 44F

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

RECORDS FOR MAY 3
HIGH 92F IN 2001
LOW 31F IN 1888
PRECIP 2.25 INS IN 1900
SNOWFALL TRACE IN 1908, 1985
PEAK GUST 71 MPH W IN 2002

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

TODAY’S REPORT PREPARED BY: Matt Douglas