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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 3, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

OVERCAST WITH A LIGHT EASTERLY WIND ATOP 
GREAT BLUE HILL....

Fog limited visibility to a maximum of 40 miles
today, with visibility to the west decreasing 
to 20 miles at 1 P.M. Wind has remained relatively
light today, with an average speed of 6 mph. No
gusts above 10 mph have been recorded so far today.
Wind shifted from E-N shortly following the 1 P.M. 
observation. A passing shower yesterday afternoon 
left 0.01 inches in the gauge, measured at 7 A.M. 
this morning. The high so far today is 60F, 3 degrees 
below the daily normal maximum of 63F. The low since 
midnight is 40F, 3 degrees below the daily normal of 43F.    

PRELIMINARY STATS FOR APRIL 2019

TEMPERATURE, Deg. F
Avg. Max. 57.2 [+1.5]
Avg. Min. 39.3 [+1.6]
Mean      48.3 [+1.6]
24-hour corrected mean: 48.5
Max. for month: 71F on the 13th, 14th, and 19th
Min. for month: 27F on the 2nd and 5th

HEATING DEGREE DAYS
Total heating units:    496 [-55]
Total for the season:  5901 [-134]
Total for last season: 5693

PRECIPITATION, Inches
Total: 8.14 [+3.59]
Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: Trace [-3.0]
Greatest in 24 hrs: Trace [10th] 

WIND, mph
Avg. uncorrected wind speed: 13.2
Avg. corrected wind speed: 13.6
Prevailing wind direction: S at 15%
Peak gust and direction: 54 W on 3rd  

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

BHO Greatest April Precipitation, inches (1885-2019):

1) 10.37 in 1987
2)  9.38 in 2004
3)  8.71 in 1929
4)  8.68 in 2007
5)  8.53 in 1904
6)  8.14 in 2019
7)  7.57 in 1935
    7.57 in 1983
9)  7.31 in 1901

The calendar day rainfall on Monday, 4/22, was more than
two and a half inches, which made it one of the wettest
calendar days ever observed in April. The finalized
amount for the day is now available.
 
BHO Greatest April Calendar Day Precipitation, inches (1885-2019):

1) 3.47 on April 1,  2004
2) 3.18 on April 21, 1991
3) 2.63 on April 16, 2018
4) 2.57 on April 22, 2019
5) 2.51 on April 24, 1898
   2.51 on April 13, 2004
6) 2.45 on April 16, 1929
7) 2.41 on April 28, 1904
8) 2.40 on April 10, 1935

Today's Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 43F; Dew Point: 42F; Wind: SE at 3 kts,
Wind: Light and variable
Sea-level pressure: 30.20 ins. Hg, falling steadily
Visibility: 35 miles, distant fog
6-hr Max temp: 43F
6-hr Min temp: 40F
24-hr Precip: 0.01 ins. 
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins. 
BHO SA 1155 E20 OVC 35 226/43/42/1303/020/ DSNT FG ALQDS
WND L/V/ 8/6// 70001 56002 10043 20040

10 A.M.
Weather: Overcast stratus
Temperature: 48F; Dew Point: 43F; Wind: SSE at 7 kts
Sea-level pressure: 30.16 ins. Hg, falling steadily
Visibility: 35 miles, distant fog
3-hr Precip: 0.00 ins. 
BHO SA 1455 E30 OVC 35 214/48/43/1607/016/ DSNT FG ALQDS/ 
8/6// 58012 


SUMMARY FOR THURSDAY, MAY 2, 2019 

TEMPERATURE (DEGREES F)
MAX.....45   NORMAL.....62
MIN.....41   NORMAL.....44
MEAN....43   NORMAL.....53

DEPARTURE FROM 30-YEAR NORMAL.......................-10
TOTAL DEPARTURE FOR THE MONTH.......................-14 [-7.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............22   DEPARTURE........+10
TOTAL HEATING UNITS FOR THE MONTH..............38   DEPARTURE.........13
TOTAL HEATING UNITS FOR THE SEASON...........5939   DEPARTURE.......-121
TOTAL HEATING UNITS LAST SEASON TO DATE......5706   DIFFERENCE......+233

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................21 NE  AT 12:45 A.M.
                   AERO.........................21 SSW AT 12:30 A.M.
                   ASOS.........................21 S   AT 12:03 A.M. 
                   DAVIS........................21 S   AT 12:03 A.M.  RMY 20
FASTEST MILE FOR YESTERDAY......................15 NE  AT 12:48 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...................16 ENE AT 12:46 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................17 ENE AT 12:46 P.M.
AVERAGE WIND SPEED AND DIRECTION...............7.5 ENE
                   ASOS........................7.9
                   DAVIS.......................7.9 ENE [70 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.01  DEPARTURE.......-0.11
                         ASOS..............0.01
TOTAL PRECIPITATION FOR THE MONTH..........0.02  DEPARTURE.......-0.22
                         ASOS..............0.02
TOTAL PRECIPITATION FOR THE YEAR..........21.20  DEPARTURE.......+2.41
                         ASOS.............21.23

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.............47.6  DEPARTURE.......-15.1


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 45/29/37/-4/0.00/0.0/748/98           40 WNW AERO 37 W   RMY 42
04/02 50/27/39/-2/..../0.0/605/79           29 S   AERO 25 S   RMY 31
04/03 62/35/49/+7/..../0.0/484/63           54 W   AERO 58 W   RMY 56
04/04 50/34/42/0/..../0.0/717/93            46 W   AERO 41 W   RMY N/A
04/05 47/27/37/-6/..../0.0/341/44           23 SSW AERO 17 SSW RMY 23
04/06 64/32/48/+5/..../0.0/536/69           24 NW  AERO 18 W   RMY 26
04/07 66/41/54/+11/0.00/0.0/320/41          24 S   AERO 18 S   RMY 25
04/08 48/34/41/-3/0.49/0.0/000/00           25 NE  AERO 20 NE  RMY 26
04/09 40/32/36/-8/0.08/0.0/000/00           23 NE  AERO 16 N   RMY 25
04/10 43/30/37/-8/T/T/000/00                32 NW  AERO 26 NW  RMY 36
04/11 51/29/40/-5/0.00/0.0/403/51           23 NW  AERO 18 NW  RMY N/A
04/12 53/38/46/+1/..../0.0/000/00           35 SSW AERO 29 SSW RMY 39
04/13 71/54/63/+17/..../0.0/167/21          38 SSW AERO 32 SSW RMY N/A
04/14 71/51/61/+15/..../0.0/224/28          25 S   AERO 18 S   RMY N/A
04/15 67/40/54/+7/..../0.0/168/21           46 W   AERO 52 W   RMY 50
04/16 58/37/48/+1/0.00/0.0/.../..           46 W   AERO 44 W   RMY 44 
04/17 62/36/49/+2/0.00/0.0/.../..           26 ESE AERO 25 S   RMY 28
04/18 63/39/51/+3/0.00/0.0/.../..           44 S   AERO 44 S   RMY 50
04/19 71/58/65/+17/..../0.0/.../..          47 SSW AERO 51 SSW RMY 52
04/20 68/60/64/+15/..../0.0/.../..          50 SSW AERO 54 SSW RMY 52
04/21 68/51/60/+11/..../0.0/.../..          35 S   AERO 35 S   RMY N/A
04/22 53/45/49/0/..../0.0/.../..            35 NNE AERO 32 NNE RMY 35
04/23 52/44/48/-2/..../0.0/.../..           30 NNE AERO 26 NNE RMY N/A
04/24 65/44/55/+5/..../0.0/.../..           29 WNW AERO 29 WNW RMY 30
04/25 61/39/50/0/0.00/0.0/.../..            22 S   AERO 22 S   RMY 21 
04/26 53/42/48/-3/..../0.0/.../..           35 ESE AERO 30 W   RMY 33
04/27 54/39/47/-4/..../.../.../..           41 W   AERO 44 W   RMY 47
04/28 51/38/45/-7/0.08/0.0/.../..           28 W   AERO 28 W   RMY N/A
04/29 60/34/47/-5/0.00/0.0/.../..           23 NW  AERO 24 WNW RMY 24
04/30 48/40/44/-8/0.17/0.0/.../..           26 NW  AERO 23 NW  RMY 25

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 57/40/49/-4/0.00/0.0/.../..           21 S   AERO 21 SSE  RMY 21
05/02 45/41/43/-10/0.02/0.0/.../..          21 NE  AERO 21 SSW  RMY 20

05/03 Low temp since midnight is 40F; 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 1.92 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966

TODAY'S REPORT PREPARED BY: Benjamin Turner