Friday, April 17, 2020
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, APRIL 17, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME
A CHILLY, BUT BRIGHT AND PLEASANT DAY ATOP
GREAT BLUE HILL…
We began the day under clear skies and chilly
conditions. The overnight low bottomed out at 29F.
The last time we reached the upper-20s was a few weeks
ago on April 1st. Visibility was fair to start at 50
miles increasing to 70 miles by the 1 PM observation.
Winds have been moderately busy clocking in so far
today at 39 MPH.
Our high temperature so far today is 49F,
which is 7 degrees below our daily normal high
temperature of 56F. The low since midnight is 29F,
which is 9 degrees below the daily normal low of 38F.
PRELIMINARY STATS FOR MARCH 2020
TEMPERATURE, Deg. F
Avg. Max. 49.8 [+5.5]
Avg. Min. 32.3 [+5.7]
Mean 41.1 [+5.6]
24-hour corrected mean: 40.5
Max. for month: 72F on the 9th
Min. for month: 15F on the 1st
HEATING DEGREE DAYS
Total heating units: 733 [-183]
Total for the season: 4873 [-611]
Total for last season: 5432
PRECIPITATION, Inches
Total: 4.67 [-0.91]
Greatest in 24 hrs: 2.37 ins. on the 23rd-24th
SNOWFALL, Inches
Total: 2.8 [-9.9]
Greatest in 24 hrs: 1.6 ins. on the 23rd
WIND, mph
Avg. uncorrected wind speed: 12.6 mph
Avg. corrected wind speed: 12.9 mph
Prevailing wind direction: W [12%]
Peak gust and direction: 56 W on the 4th
SUNSHINE:
Campbell-Stokes card minutes: 11298 minutes of possible 21516 or 53%
Astronomical total minutes: 11708 minutes of possible 22287 or 53%
Today’s Observations:
7 A.M.
Weather: Clear (few cirrostratus)
Temperature: 34F; Dew Point: 19F; Relative Humidity: 54%
Wind: W at 11 kts
Sea-level pressure: 30.20 ins. Hg: rising, then more slowly
Visibility: 50 miles
6-hr Max temp: 34F
6-hr Min temp: 29F
24-hr Precip: Trace
24-hr Snowfall: Trace
BHO SA 1155 CLR 50 228/34/19/2811/020/ FEW CS S DSNT HZ ALQDS/
8/005 51018 10034 20029
10 A.M.
Weather: Scattered Cumulus (few cirrus)
Temperature: 40F; Dew Point: 17F; Relative Humidity: 39%
Wind: W at 17G24 kts
Peak Wind: 35 MPH (30 kts) W at 8:38 A.M.
Sea-level pressure: 30.19 ins. Hg: falling, then rising
Visibility: 70 miles
3-hr Precip: 0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 50 SCT 70 220/40/17/2717G24/019/
FEW CI SE-SW PK WND 2730/1338/ 8/101 55008
1 P.M.
Weather: Scattered Cumulus (few cirrus)
Temperature: 49F; Dew Point: 13F; Relative Humidity: 23%
Wind: WNW at 14G26 kts
Peake Wind: 39 MPH (34 kts) WNW at 11:42 A.M.
Sea-level pressure: 30.10 ins. Hg: falling, then more rapidly
Visibility: 70 miles
6-hr Max temp: 49F
6-hr Min temp: 34F
6-hr Precip: 0.00 ins
6-hr Snowfall: 0.0 ins
BHO SA 1755 50 SCT 70 192/49/13/2914G26/010/
FEW CI SE-SW PK WND 2934/1642/ 8/101 58028 10049 20034
SUMMARY FOR THURSDAY, APRIL 16, 2020
TEMPERATURE (DEGREES F)
MAX…..47 NORMAL…..56
MIN…..32 NORMAL…..38
MEAN….40 NORMAL…..47
DEPARTURE FROM 30-YEAR NORMAL………………..-7
TOTAL DEPARTURE FOR THE MONTH………………..+9 [+0.4 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………25 DEPARTURE……. +7
TOTAL HEATING UNITS FOR THE MONTH…………..327 DEPARTURE…….-10
TOTAL HEATING UNITS FOR THE SEASON…………5200 DEPARTURE……-620
TOTAL HEATING UNITS LAST SEASON TO DATE…….5712 DEPARTURE……-512
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..33 WNW AT 5:59 P.M.
AERO…………………….33 WNW AT 5:48 P.M
ASOS…………………….32 WNW AT 6:00 P.M.
DAVIS……………………34 WNW AT 12:28 P.M. RMY 32
FASTEST MILE FOR YESTERDAY………………….25 WNW AT 6:04 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….23 WNW AT 6:04 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………25 WNW AT 6:01 P.M.
AVERAGE WIND SPEED AND DIRECTION…………….12.6 W
ASOS…………………….11.9
DAVIS……………………13.0 WNW [287 deg.]
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….TRACE DEPARTURE……-0.15
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….4.92 DEPARTURE……+2.26
ASOS…………..5.10
TOTAL PRECIPITATION FOR THE YEAR……….14.25 DEPARTURE……-2.41
ASOS………….14.83
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……..TRACE DEPARTURE…….-0.1
TOTAL SNOWFALL FOR THE MONTH…………..TRACE DEPARTURE…….-2.3
TOTAL SNOWFALL FOR THE SEASON…………..27.6 DEPARTURE……-34.4
PRELIMINARY CLIMATE SUMMARY FOR MARCH 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
03/01 33/15/24/-7/0.00/0.0/676/100 28 WNW AERO 28 WNW RMY 27
03/02 52/24/38/+7/T/T/482/71 40 S AERO 39 S RMY 41
03/03 64/45/55/+23/0.05/0.0/361/53 30 S AERO 30 S RMY N/A
03/04 50/38/44/+12/0.04/0.0/561/82 56 W AERO 56 W RMY 58
03/05 51/32/42/+10/0.00/0.0/666/97 31 W AERO 31 NW RMY 32
03/06 47/30/39/+7/0.04/0.3/283/41 46 NE AERO 45 NE RMY 46
03/07 43/26/35/+2/0.03/0.5/534/77 42 N AERO 43 N RMY 44
03/08 53/26/40/+7/0.00/0.0/508/73 31 W AERO 30 W RMY 28
03/09 72/40/56/+23/0.00/0.0/685/98 32 SW AERO 32 SW RMY 31
03/10 68/49/59/+26/0.00/0.0/246/35 48 WSW AERO 46 WSW RMY 49
03/11 56/37/47/+13/0.00/0.0/501/71 31 WNW AERO M M RMY 21
03/12 46/31/39/+5/0.01/0.0/156/22 21 SE AERO 18 SE RMY N/A
03/13 59/38/49/+15/0.20/0.0/000/00 46 WNW AERO 44 WNW RMY 46
03/14 51/35/43/+8/0.00/0.0/613/86 37 W AERO 36 W RMY 35
03/15 47/28/38/+3/0.00/0.0/680/95 28 NW AERO 28 NW RMY N/A
03/16 36/22/29/-6/0.00/0.0/618/86 21 NE AERO 21 ESE RMY 21
03/17 43/28/36/0/0.06/0.4/000/00 29 W AERO 30 W RMY 29
03/18 54/31/43/+7/0.00/0.0/609/84 26 S AERO 26 S RMY 26
03/19 43/37/40/+4/0.63/0.0/000/00 36 E AERO 35 E RMY 34
03/20 66/37/52/+15/0.03/0.0/000/00 48 W AERO 48 W RMY 46
03/21 55/29/42/+5/0.00/0.0/535/73 45 W AERO 48 W RMY N/A
03/22 36/23/30/-7/0.00/0.0/692/94 23 NE AERO 24 NE RMY 23
03/23 40/25/33/-5/1.74/1.6/037/05 38 NNE AERO 39 NNE RMY 38
03/24 48/33/41/+3/0.63/0.0/148/20 37 NNW AERO 37 NNW RMY N/A
03/25 41/35/38/0/0.03/0.0/000/00 28 ENE AERO 28 ENE RMY 27
03/26 51/30/41/+2/0.00/0.0/613/82 25 SSE AERO 26 SSW RMY N/A
03/27 61/41/51/+12/0.00/0.0/631/84 32 NW AERO M M RMY 33
03/28 56/36/46/+7/0.15/0.0/309/41 22 S AERO 21 E RMY N/A
03/29 43/37/40/0/0.74/0.0/000/00 32 NE AERO 33 NE RMY 33
03/30 40/34/37/-3/0.21/0.0/000/00 33 NE AERO 33 NE RMY 33
03/31 40/29/35/-6/0.08/0.0/564/74 28 ENE AERO 26 ENE RMY N/A
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/…/.. 28 NE AERO 28 NE RMY 30
04/02 46/35/41/0/…/0.0/…/.. 39 NW AER0 40 NW RMY 41
04/03 42/38/40/-2/…./0.0/…/.. 48 NE AERO 53 NE RMY 49
04/04 46/36/41/-1/…./0.0/…/.. 38 NE AERO 38 NE RMY N/A
04/05 55/36/46/+3/T/0.0/…/.. 22 S AERO 21 S RMY 21
04/06 61/40/51/+8/0.00/0.0/…/.. 29 NW AERO 30 NW RMY 29
04/07 63/42/53/+10/0.00/0.0/…/.. 29 W AERO 30 W RMY 28
04/08 50/41/46/+2/…./…/…/.. 23 S AERO 22 S RMY 22
04/09 47/37/42/-2/…./…/…/.. 58 W AERO 58 W RMY 56
04/10 47/35/41/-4/0.02/T/…/.. 48 W AERO 50 W RMY 53
04/11 51/33/42/-3/0.00/0.0/…/.. 38 WNW AERO 39 WNW RMY 40
04/12 60/33/47/+2/0.00/0.0/…/.. 38 S AERO 40 S RMY N/A
04/13 59/50/55/+9/1.42/0.0/…/.. 79 S AERO 83 S RMY 78
04/14 57/41/49/+3/0.00/0.0/…/.. 41 W AERO 40 W RMY N/A
04/15 52/36/44/-3/0.02/0.0/…/.. 37 W AERO 36 W RMY 37
04/16 47/32/40/-7/T/T/…/.. 33 WNW AERO 33 WNW RMY 32
04/17 The low since midnight is 29F, daily normal minimum is 38F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR APRIL 17
HIGH 93 IN 2002
LOW 21 IN 1908
PRECIP 1.68 IN 1954
SNOWFALL 1.0 IN. IN 1899
PEAK GUST 63 MPH ESE IN 2011
RECORDS FOR APRIL 18
HIGH 92 IN 1976
LOW 23 1887
PRECIP 1.48 IN 1954
SNOWFALL 3.7 IN. IN 1965
PEAK GUST 59 MPH S IN 1982
TODAY’S REPORT PREPARED BY: Andrew Swanson
