Sunday, May 10, 2020

| May 11, 2020 | Reply

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 10, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

A BREEZY AND FAIR WEATHER DAY WITH A STRONG
WESTERLY WIND IN THE AFTERNOON HOURS….

The summit of Great Blue Hill saw another fair
weather day, with strong winds from the west
in the afternoon. Wind speed has reached 25 mph
on average, with a max gust of almost 50 mph.
Skies have remained partly cloudy, and visibility
is excellent at 85 miles. Conditions are dry, with
a humidity of 30% seen at the 1 P.M. observation.

The high so far today is 54F, this is 11 degrees
below our daily normal high temperature of 65F.
The low since midnight is 31F, which is 15 degrees
below the daily normal low of 46F.

PRELIMINARY STATS FOR APRIL 2020

TEMPERATURE, Deg. F
Avg. Max. 50.6 [-5.1]
Avg. Min. 35.8 [-1.9]
Mean      43.4 [-3.3]
24-hour corrected mean: 42.9
Max. for month: 63F on the 7th
Min. for month: 28F on the 1st

HEATING DEGREE DAYS
Total heating units:    648 [+97]
Total for the season:  5521 [-514]
Total for last season: 5900

PRECIPITATION, Inches
Total: 7.71 [+3.16]
Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: 4.3 [+1.3]
Greatest in 24 hrs: 4.3 ins. on the 18th

WIND, mph
Avg. uncorrected wind speed: 13.9 mph
Avg. corrected wind speed:   14.3 mph
Prevailing wind direction:   W [24%]
Peak gust and direction:     79 S on the 13th

SUNSHINE:
Campbell-Stokes card minutes: N/A
Astronomical total minutes: N/A

Today’s Observations:

7 A.M.
Weather: Scattered stratocumulus and altostratus
Temperature: 38F; Dew Point: 26F; Relative Humidity: 62%
Wind: WNW at 10G19 kts
Sea-level pressure: 29.96 ins. Hg: rising steadily
Visibility: 80 miles
6-hr Max temp: 38F
6-hr Min temp: 31F
24-hr Precip:   Trace
24-hr Snowfall: Trace
BHO SA 1155 60 SCT 150 SCT 80 147/38/26/2310G19/996/ NEW
SNW PST 24 HRS TRACE/ 8/460 51007 10038 20031

10 A.M.
Weather: Broken stratocumulus
Temperature: 46F; Dew Point: 26F; Relative Humidity: 44%
Wind: W at 27G31 kts, peak of 36 mph at 9:46 A.M.
Sea-level pressure: 29.96 ins. Hg: falling steadily
Visibility: 80 miles
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E60 BKN 80 145/46/26/2814G31/996/ PK WND 2731/46/ 8/800 58002

1 P.M.
Weather: Broken stratocumulus and cirrostratus
Temperature: 54F; Dew Point: 25F; Relative Humidity: 32%
Wind: W at 18G27 kts, peak of 41 mph at 12:27 P.M.
Sea-level pressure: 29.93 ins. Hg: falling steadily
Visibility: 85 miles
6-hr Max temp: 54F
6-hr Min temp: 38F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E60 BKN 250 BKN 85 136/54/25/2618G27/993/
PK WND 2635/27/ 8/808 58009 10054 20038

SUMMARY FOR SATURDAY, MAY 9, 2020

TEMPERATURE (DEGREES F)
MAX…..44   NORMAL…..64
MIN…..32   NORMAL…..46
MEAN….38   NORMAL…..55

DEPARTURE FROM 30-YEAR NORMAL………………-17
TOTAL DEPARTURE FOR THE MONTH………………-11 [-1.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………27  DEPARTURE…….+17
TOTAL HEATING UNITS FOR THE MONTH…………..112  DEPARTURE…….+9
TOTAL HEATING UNITS FOR THE SEASON…………5633  DEPARTURE……-505
TOTAL HEATING UNITS LAST SEASON TO DATE…….6025  DEPARTURE……-392

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH…………….2  DEPARTURE……..+1
TOTAL COOLING UNITS FOR THE SEASON……………2  DEPARTURE……..-3
TOTAL COOLING UNITS LAST SEASON TO DATE……….0  DEPARTURE……..+2

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..52 W   AT  2:42 P.M.
AERO…………………….53 W   AT  1:01 P.M.
ASOS…………………….52 W   AT  4:41 P.M.
DAVIS……………………53 W   AT  4:41 P.M. RMY 54
FASTEST MILE FOR YESTERDAY………………….42 W   AT  4:54 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….38 W   AT  4:57 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………43 W   AT  4:57 P.M.
AVERAGE WIND SPEED AND DIRECTION…………….21.4 W
ASOS…………………….20.4
DAVIS……………………21.4 WNW [287 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…Trace  DEPARTURE……-0.12
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.39  DEPARTURE……+0.40
ASOS…………..1.39
TOTAL PRECIPITATION FOR THE YEAR……….18.43  DEPARTURE……-1.11
ASOS………….18.99

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……..Trace  DEPARTURE……..0.0
TOTAL SNOWFALL FOR THE MONTH…………..Trace  DEPARTURE……..0.0
TOTAL SNOWFALL FOR THE SEASON…………..31.9  DEPARTURE……-30.8

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

04/01  42/28/35/-6/0.00/0.0/008/01         28 NE  AERO 28 NE  RMY 30
04/02  46/35/41/0/0.34/0.0/000/00          39 NW  AER0 40 NW  RMY 41
04/03  42/38/40/-2/2.14/0.0/000/00         48 NE  AERO 53 NE  RMY 49
04/04  46/36/41/-1/0.24/0.0/278/36         38 NE  AERO 38 NE  RMY N/A
04/05  55/36/46/+3/0.00/0.0/039/05         22 S   AERO 21 S   RMY 21
04/06  61/40/51/+8/0.00/0.0/732/94         29 NW  AERO 30 NW  RMY 29
04/07  63/42/53/+10/0.00/0.0/649/83        29 W   AERO 30 W   RMY 28
04/08  50/41/46/+2/0.08/T/047/06           23 S   AERO 22 S   RMY 22
04/09  47/37/42/-2/0.66/T/000/00           58 W   AERO 58 W   RMY 56
04/10  47/35/41/-4/0.02/T/324/41           48 W   AERO 50 W   RMY 53
04/11  51/33/42/-3/0.00/0.0/730/92         38 WNW AERO 39 WNW RMY 40
04/12  60/33/47/+2/0.00/0.0/326/41         38 S   AERO 40 S   RMY N/A
04/13  59/50/55/+9/1.42/0.0/000/00         79 S   AERO 83 S   RMY 78
04/14  57/41/49/+3/0.00/0.0/641/80         41 W   AERO 40 W   RMY N/A
04/15  52/36/44/-3/0.02/0.0/450/56         37 W   AERO 36 W   RMY 37
04/16  47/32/40/-7/T/T/379/47              33 WNW AERO 33 WNW RMY 32
04/17  49/29/39/-8/0.01/0.0/591/73         41 W   AERO 39 W   RMY 41
04/18  37/31/34/-14/0.73/4.3/000/00        29 NE  AERO 25 NE  RMY 25
04/19  60/31/46/-2/0.00/0.0/693/85         40 SSW AERO 40 SSW RMY 41
04/20  49/37/43/-6/0.00/0.0/…/..         25 ENE AERO 22 W   RMY N/A
04/21  53/33/43/-6/0.34/…/…/..         52 S   AERO 52 S   RMY 52
04/22  43/30/37/-12/0.00/0.0/…/..        51 W   AERO 50 W   RMY 50
04/23  55/29/42/-8/0.00/0.0/…/..         31 W   AERO 29 W   RMY N/A
04/24  42/37/40/-10/0.34/…/…/..        31 NNE AERO 29 NNE RMY 29
04/25  60/38/49/-1/0.00/0.0/…/..         25 S   AERO 24 S   RMY 24
04/26  51/38/45/-6/0.42/0.0/…/..         51 NE  AERO 50 NE  RMY 50
04/27  39/35/37/-14/0.94/T/…/..          54 NE  AERO 52 NNE RMY 55
04/28  48/35/42/-10/0.00/0.0/…/..        28 N   AERO 27 N   RMY N/A
04/29  55/35/45/-7/0.00/0.0/…/..         24 ENE AERO 23 ENE RMY 22
04/30  52/42/47/-5/0.01/0.0/…/..         36 SE  AERO 32 SE  RMY N/A

DAILY RECORDS FOR APRIL 2020

4/13/2020
NEW PEAK GUST OF 79 MPH S, REPLACING THE OLD
RECORD OF 59 MPH SSW IN 1995

4/18/2020
NEW RECORD SNOWFALL OF 4.3 INS, REPLACING THE OLD
RECORD OF 3.7 INS IN 1965

4/27/2020
NEW RECORD LOW MAX TEMPERATURE OF 39F, REPLACING
THE OLD RECORD OF 40F IN 1917

PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

05/01  64/52/58/+5/…./0.0/…/..         46 SSE  AERO 44 SSE RMY N/A
05/02  70/42/56/+3/…./0.0/…/..         41 NW   AERO 40 NW  RMY N/A
05/03  78/55/67/+14/0.00/0.0/…/..        35 SSW  AERO 35 SSW RMY 36
05/04  72/45/59/+5/T/0.0/…/..            37 NW   AERO 40 WNW RMY 39
05/05  60/40/50/-4/0.00/0.0/…/..         31 NW   AERO 32 NW  RMY N/A
05/06  57/38/48/-6/T/0.0/…/..            24 ESE  AERO 22 ENE RMY 22
05/07  63/37/50/-5/0/0.0/…/..            30 WSW  AERO 29 WSW RMY N/A
05/08  57/40/49/-6/…./0.0/…/..         31 W    AERO 32 W   RMY N/A
05/09  44/32/38/-17/…./T/…/..          52 W    AERO 53 W   RMY 54

05/10 The low since midnight is 31F, the daily normal low is 46F

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

RECORDS FOR MAY 10
HIGH 93F IN 1896
LOW 29F  IN 1900
PRE 1.85 INS IN 1998
SNOW 2.8 INS 1977 (7.8 INS TOTAL 5/9-5/10 1977)
PEAK GUST 64 MPH S IN 1990

RECORDS FOR MAY 11
HIGH 90F IN 1993
LOW 28F IN 1900
PRE 1.28 INS IN 1957
SNOW 1.0 INS IN 1907 (LATEST MEASURABLE SNOW ON RECORD)
PEAK GUST 75e MPH NW IN 1945

TODAY’S REPORT PREPARED BY: Benjamin Turner

Category: Daily Discussions

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