Saturday, April 4, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, APRIL 4, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

A WET AND CHILLY START LEAD TO A CLEARER
AFTERNOON….

Following some much-needed rainfall overnight, the
observatory has experienced fair weather in the
afternoon. Since 7 A.M. yesterday, 1.60 inches of
rain fell, ending around 6 A.M. this morning. With
a net increase in pressure, visibility rose from
5 miles this morning to 70 miles this afternoon.
Wind decreased as the day went on, becoming less than
10 mph by 2 P.M.

Our high temperature so far today is 44F, which is 7 degrees
below our daily normal high temperature of 51F. The low
since midnight is 36F, which is 3 degrees above the daily
normal low of 33F.

PRELIMINARY STATS FOR MARCH 2020

TEMPERATURE, Deg. F
Avg. Max. 49.8 [+5.5] Avg. Min. 32.3 [+5.7] Mean      41.4 [+5.9] 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: N/A

SNOWFALL, Inches
Total: 2.8 [-9.9] Greatest in 24 hrs: N/A

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: N/A
Astronomical total minutes: N/A

Today’s Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 36F; Dew Point: 36F; Relative Humidity: 100%
Wind: NNE at 11G21 kts
Peak wind: 36 MPH (31 kts) NE at 5:25 A.M.
Sea-level pressure: 30.02 ins. Hg: rising steadily
Visibility: 5 miles, fog
6-hr Max temp: 39F
6-hr Min temp: 36F
24-hr Precip:  1.60 ins.
24-hr Snowfall: 0.0 ins.
BHO SA 1155 E20 OVC 5F 165/36/36/0211G21/002/ PK WND 0531/1025/
8/6// 70160 53023 10039 20036

10 A.M.
Weather: Overcast stratus
Temperature: 39F; Dew Point: 36F; Relative Humidity: 89%
Wind: NNE at 12G21 kts
Sea-level pressure: 30.05 ins. Hg: rising steadily
Visibility: 15 miles, thin fog
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E20 OVC 15 175/39/36/0312G21/005/ THN FG ALQDS/ 8/6//
51010

1 P.M.
Weather: Broken stratocumulus
Temperature: 44F; Dew Point: 36F; Relative Humidity: 74%
Wind: NE at 10G15 kts
Sea-level pressure: 30.03 ins. Hg: rising then falling
Visibility: 70 miles
6-hr Max temp: 44F
6-hr Min temp: 36F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E20 BKN 70 170/44/36/0410G15/003/ 8/400 58005 10044
20036

SUMMARY FOR FRIDAY, APRIL 3, 2020

TEMPERATURE (DEGREES F)
MAX…..42   NORMAL…..51
MIN…..38   NORMAL…..33
MEAN….40   NORMAL…..42

DEPARTURE FROM 30-YEAR NORMAL………………..-2
TOTAL DEPARTURE FOR THE MONTH………………..-8 [-2.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………25  DEPARTURE……..+2
TOTAL HEATING UNITS FOR THE MONTH……………79  DEPARTURE……..+8
TOTAL HEATING UNITS FOR THE SEASON…………4952  DEPARTURE……-603
TOTAL HEATING UNITS LAST SEASON TO DATE…….5474  DEPARTURE……-522

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..48 NE  AT 11:39 A.M.
AERO…………………….53 NE  AT  4:58 P.M
ASOS…………………….49 N   AT  1:23 P.M.
DAVIS……………………48 NE  AT 10:40 A.M. RMY 49
FASTEST MILE FOR YESTERDAY………………….33 NNE AT 10:52 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….31 NNE AT  2:33 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………33 NNE AT 10:51 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..21.9 NE
ASOS…………………..20.7
DAVIS………………….21.0 NNE [29 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….1.60  DEPARTURE……+1.43
ASOS…………..1.77
TOTAL PRECIPITATION FOR THE MONTH……….1.60  DEPARTURE……+2.21
ASOS…………..1.77
TOTAL PRECIPITATION FOR THE YEAR……….12.05  DEPARTURE……-2.46
ASOS………….12.55

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.2
TOTAL SNOWFALL FOR THE MONTH…………….0.0  DEPARTURE…….-0.6
TOTAL SNOWFALL FOR THE SEASON…………..27.6  DEPARTURE……-32.7

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/…./0.0/361/53        30 S   AERO 30 S   RMY N/A
03/04  50/38/44/+12/…./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/…./…/283/41         46 NE  AERO 45 NE  RMY 46
03/07  43/26/35/+2/…./…/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/…./0.0/156/22         21 SE  AERO 18 SE  RMY N/A
03/13  59/38/49/+15/…./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/…./0.4/000/00          29 W   AERO 30 W   RMY 29
03/18  54/31/43/+7/…./0.0/609/84         26 S   AERO 26 S   RMY 26
03/19  43/37/40/+4/…./0.0/000/00         36 E   AERO 35 E   RMY 34
03/20  66/37/52/+15/…./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/…./1.6/037/05         38 NNE AERO 39 NNE RMY 38
03/24  48/33/41/+3/…./…/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/…./0.0/613/82         25 SSE AERO 26 SSW RMY N/A
03/27  61/41/51/+12/…./0.0/…/..        32 NW  AERO M  M   RMY 33
03/28  56/36/46/+7/…./0.0/…/..         22 S   AERO 21 E   RMY N/A
03/29  43/37/40/0/…./0.0/…/..          32 NE  AERO 33 NE  RMY 33
03/30  40/34/37/-3/…./0.0/…/..         33 NE  AERO 33 NE  RMY 33
03/31  40/29/35/-6/…./0.0/…/..         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 The low since midnight is 36F, daily normal minimum is 33F

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

RECORDS FOR APRIL 4
HIGH 76 IN 2010
LOW 12 IN 1954
PRECIP 1.45 IN. IN 1987
SNOWFALL 7.3 IN. IN 2016
PEAK GUST 80 MPH WNW IN 1963

RECORDS FOR APRIL 5
HIGH 81 IN 1928
LOW 15 IN 1995
PRECIP 2.15 IN. IN 1987
SNOWFALL 4.0 IN. IN 1898
PEAK GUST 76 MPH WNW IN 1963

TODAY’S REPORT PREPARED BY: Benjamin Turner