Thursday, May 7, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MAY 7, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

PLEASANT SPRING DAY WITH A MIX OF CLOUDS AND SUN….

Today has been a pretty pleasant day with a mix of sun
and clouds and temperatures this afternoon close to
normal.

The air is very dry however with dew points falling
into the upper teens and low 20s giving us pretty
low relative humidity levels.

The high so far today is 63F, this is 1 degree below
our daily normal high temperature of 64F. The
low since midnight is 37F, which is 8 degrees below
the daily normal low of 45F.

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: N/A

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 altocumulus/altostratus
Temperature: 43F; Dew Point: 39F; Relative Humidity: 87%
Wind: WSW at 4 kts
Sea-level pressure: 29.70 ins. Hg: falling then rising
Visibility: 75 miles
6-hr Max temp: 43F
6-hr Min temp: 37F
24-hr Precip: TRACE
24-hr Snowfall: 0.0 ins.
BHO SA 1155 80 SCT 75 056/43/39/2504/970/ 8/070 53004 70000
10043 20037

10 A.M.
Weather: Broken cumulus, broken altocumulus
Temperature: 56F; Dew Point: 26F; Relative Humidity: 31%
Wind: NW at 7G19 kts
Sea-level pressure: 29.68 ins. Hg: falling, then steady
Visibility: 70 miles
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E50 BKN 80 BKN 70 051/56/26/3307G19/968/ 8/270 56005

1 P.M.
Weather: Broken cumulus
Temperature: 60F; Dew Point: 21F; Relative Humidity: 22%
Wind: NW at 9G16 kts
Sea-level pressure: 29.67 ins. Hg: falling, steady
Visibility: 60 miles
6-hr Max temp: 63F
6-hr Min temp: 43F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E70 BKN 60 047/60/21/3209G16/967/ 8/200 56004
10063 20043

SUMMARY FOR WEDNESDAY, MAY 6, 2020

TEMPERATURE (DEGREES F)
MAX…..57   NORMAL…..64
MIN…..38   NORMAL…..45
MEAN….48   NORMAL…..54

DEPARTURE FROM 30-YEAR NORMAL……………… -6
TOTAL DEPARTURE FOR THE MONTH………………+17 [+2.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………17  DEPARTURE……. +6
TOTAL HEATING UNITS FOR THE MONTH……………54  DEPARTURE…….-17
TOTAL HEATING UNITS FOR THE SEASON…………5575  DEPARTURE……-531
TOTAL HEATING UNITS LAST SEASON TO DATE…….5997  DEPARTURE……-422

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

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..24 ESE AT  8:28 P.M.
AERO…………………….22 ENE AT  1:04 P.M.
ASOS…………………….23 ENE AT  1:06 P.M.
DAVIS……………………22 ENE AT  1:05 P.M. RMY 22
FASTEST MILE FOR YESTERDAY………………….17 ESE AT  8:31 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 ESE AT  8:32 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………17 ENE AT  2:20 P.M.
AVERAGE WIND SPEED AND DIRECTION……………. 7.9 ENE
ASOS……………………. 8.9
DAVIS…………………… 8.5 ENE [072 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…TRACE  DEPARTURE……-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.94  DEPARTURE……+0.19
ASOS…………..0.96
TOTAL PRECIPITATION FOR THE YEAR……….17.97  DEPARTURE……-1.33
ASOS………….18.60

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…………..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/…/0.0/000/00           39 NW  AER0 40 NW  RMY 41
04/03  42/38/40/-2/…./0.0/000/00         48 NE  AERO 53 NE  RMY 49
04/04  46/36/41/-1/…./0.0/278/36         38 NE  AERO 38 NE  RMY N/A
04/05  55/36/46/+3/T/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/…./…/047/06         23 S   AERO 22 S   RMY 22
04/09  47/37/42/-2/…./…/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/…./0.0/591/73         41 W   AERO 39 W   RMY 41
04/18  37/31/34/-14/…./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/…./…/…/..         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/…./…/…/..        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/…./0.0/…/..         51 NE  AERO 50 NE  RMY 50
04/27  39/35/37/-14/…./T/…/..          54 NE  AERO 52 NNE RMY 55
04/28  48/35/42/-10/…./…/…/..        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/…/0.0/…/..          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 The low since midnight is 37F, 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 7
HIGH 93F IN 1930
LOW 33F IN 1970
PRECIP 1.19 INCHES IN 2005
SNOWFALL TRACE IN 1967
PEAK GUST 66e MPH WNW IN 1940

RECORDS FOR MAY 8
HIGH 89F IN 2000
LOW 29F IN 1956
PRECIP 1.48 INCHES IN 1886
SNOWFALL TRACE IN 1898, 1947
PEAK GUST 68e MPH NNW IN 1943

TODAY’S REPORT PREPARED BY: Matt Douglas and Benjamin Turner