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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MAY 16, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

FAIR WEATHER WITH MORE NORMAL TEMPERATURES
FOR THIS TIME OF YEAR....

Weather conditions began partly cloudy, becoming
cloudier as the day went on. Visibility has remained 
70 miles throughout the day. Wind has shifted from S-NE
since this morning, becoming lighter as the day went on. 
abundant sunshine has brought temperatures closer to 
seasonal normals. The high so far today is 68F, a degree
above the normal maximum of 67F. The low since midnight 
is 46F, a degree below the normal daily minimum of 47F. 


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: 47.3
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: 3.00 ins. on the 22nd-23rd

SNOWFALL, Inches
Total: Trace [-3.0]
Greatest in 24 hrs: Trace on the 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: 8238 minutes of possible 23250 or 35%
Astronomical total minutes:   8543 minutes of possible 24086 or 35%

BHO Greatest April Precipitation, inches (1886-2019):

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 (1886-2019):

1) 3.47 on April 1,  2004
2) 3.18 on April 21, 1991
3) 2.63 on April 16, 2018
4) 2.60 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

BHO Lowest April Sunshine, hours (1886-2019):

1)  82.6 in 1901  [21%]
2) 121.1 in 1987  [31%]
3) 121.7 in 1988  [31%]
4) 131.6 in 1983  [34%]
5) 132.2 in 1921  [34%]
6) 137.3 in 2019  [35%]
7) 138.1 in 1939  [36%]
8) 140.7 in 1955  [36%]
9) 141.1 in 2000  [36%]

Today's Observations:

7 A.M.
Weather: Scattered cirrus, few cumulus in all directions
Temperature: 53F; Dew Point: 43F; Wind: S at 3 kts,
Wind: Light and variable
Sea-level pressure: 29.85 ins. Hg, falling then rising 
Visibility: 70 miles
6-hr Max temp: 53F
6-hr Min temp: 46F
24-hr Precip: 0.00 ins. 
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins. 
BHO SA 1155 250 SCT 70 107/53/43/1903/985/ FEW CU 
ALQDS WND L/V/ 8/102 53014 10053 20046  

10 A.M.
Weather: Scattered cumulus, broken altocumulus
Temperature: 60F; Dew Point: 42F; Wind: W at 4 kts,
Wind: Light and variable
Sea-level pressure: 29.85 ins. Hg, steady
Visibility: 70 miles
3-hr Precip: 0.00 ins. 
BHO SA 1455 40 SCT E65 BKN 70 107/60/42/2604/985/ 
WND L/V/ 8/210 50000 

1 P.M.
Weather: Scattered cumulus, broken altocumulus
Temperature: 68F; Dew Point: 40F; Wind: ENE at 7G12 kts 
Sea-level pressure: 29.83 ins. Hg, falling steadily
Visibility: 75 miles
6-hr Max temp: 68F
6-hr Min temp: 53F
6-hr Precip: 0.00 ins. 
BHO SA 1755 40 SCT E65 BKN 75 101/68/40/0707G12/983/ 
8/210 58006 10068 20053

SUMMARY FOR WEDNESDAY, MAY 15, 2019 

TEMPERATURE (DEGREES F)
MAX.....58   NORMAL.....66
MIN.....40   NORMAL.....48
MEAN....49   NORMAL.....57

DEPARTURE FROM 30-YEAR NORMAL........................-8
TOTAL DEPARTURE FOR THE MONTH.......................-72 [-5.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............16   DEPARTURE.........+8
TOTAL HEATING UNITS FOR THE MONTH.............224   DEPARTURE........+64
TOTAL HEATING UNITS FOR THE SEASON...........6125   DEPARTURE........-70
TOTAL HEATING UNITS LAST SEASON TO DATE......5775   DIFFERENCE......+350

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................28 NW  AT  3:47 P.M.
                   AERO..........................M M   AT N/A
                   ASOS.........................28 WNW AT  3:47 P.M. 
                   DAVIS........................29 W   AT  3:46 P.M.  RMY 28
FASTEST MILE FOR YESTERDAY......................19 WNW AT  3:45 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...................20 NW  AT  3:45 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................21 W   AT  3:45 P.M.
AVERAGE WIND SPEED AND DIRECTION...............8.5 NW
                   ASOS........................8.8
                   DAVIS.......................8.8 W [273 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE.......-0.12
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........2.44  DEPARTURE.......+0.61
                         ASOS..............2.37
TOTAL PRECIPITATION FOR THE YEAR..........23.62  DEPARTURE.......+3.24
                         ASOS.............23.58


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/-2/0.08/0.0/605/79           29 S   AERO 25 S   RMY 31
04/03 62/35/49/+7/0.36/0.0/484/63           54 W   AERO 58 W   RMY 56
04/04 50/34/42/0/0.00/0.0/717/93            46 W   AERO 41 W   RMY N/A
04/05 47/27/37/-6/0.10/0.0/341/44           23 SSW AERO 17 SSW RMY 23
04/06 64/32/48/+5/0.12/0.0/536/69           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/+1/0.15/0.0/000/00           35 SSW AERO 29 SSW RMY 39
04/13 71/54/63/+17/0.38/0.0/167/21          38 SSW AERO 32 SSW RMY N/A
04/14 71/51/61/+15/0.15/0.0/224/28          25 S   AERO 18 S   RMY N/A
04/15 67/40/54/+7/0.93/0.0/168/21           46 W   AERO 52 W   RMY 50
04/16 58/37/48/+1/0.00/0.0/805/100          46 W   AERO 44 W   RMY 44 
04/17 62/36/49/+2/0.00/0.0/807/100          26 ESE AERO 25 S   RMY 28
04/18 63/39/51/+3/T/0.0/000/00              44 S   AERO 44 S   RMY 50
04/19 71/58/65/+17/0.03/0.0/049/06          47 SSW AERO 51 SSW RMY 52
04/20 68/60/64/+15/0.46/0.0/000/00          50 SSW AERO 54 SSW RMY 52
04/21 68/51/60/+11/0.06/0.0/123/15          35 S   AERO 35 S   RMY N/A
04/22 53/45/49/0/2.60/0.0/000/00            35 NNE AERO 32 NNE RMY 35
04/23 52/44/48/-2/0.42/0.0/041/05           30 NNE AERO 26 NNE RMY N/A
04/24 65/44/55/+5/0.02/0.0/438/53           29 WNW AERO 29 WNW RMY 30
04/25 61/39/50/0/0.00/0.0/696/84            22 S   AERO 22 S   RMY 21 
04/26 53/42/48/-3/0.84/0.0/000/00           35 ESE AERO 30 W   RMY 33
04/27 54/39/47/-4/0.62/0.0/100/12           41 W   AERO 44 W   RMY 47
04/28 51/38/45/-7/0.08/0.0/159/19           28 W   AERO 28 W   RMY N/A
04/29 60/34/47/-5/0.00/0.0/612/73           23 NW  AERO 24 WNW RMY 24
04/30 48/40/44/-8/0.17/0.0/000/00           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 60/43/52/-1/..../.../.../..           23 S   AERO 23 S    RMY 22
05/04 54/46/50/-4/..../.../.../..           14 ENE AERO 14 ENE  RMY 17
05/05 52/44/48/-6/0.00/0.0/.../..           18 NE  AERO 20 NE   RMY N/A
05/06 58/44/51/-3/..../0.0/.../..           25 NE  AERO 26 ENE  RMY 24
05/07 72/41/57/+2/0.12/0.0/.../..           30 S   AERO 29 S    RMY 30
05/08 67/48/58/+3/0.00/0.0/.../..           20 NE  AERO 20 NE   RMY 19
05/09 60/43/52/-3/0.00/0.0/.../..           21 SE  AERO 21 E    RMY 22
05/10 61/46/54/-1/0.16/0.0/.../..           35 S   AERO 37 S    RMY 37
05/11 68/50/59/+3/..../.../.../..           26 NW  AERO M  M    RMY N/A
05/12 50/36/43/-13/0.68/T/.../..            30 ENE AERO M  M    RMY N/A
05/13 52/38/45/-11/..../.../.../..          35 E   AERO M  M    RMY 34
05/14 44/38/41/-16/..../.../.../..          26 NNE AERO M  M    RMY 25
05/15 58/40/49/-8/..../.../.../..           28 NW  AERO M  M    RMY 28

05/16 Low temp since midnight is 46F; normal low is 48F


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

RECORDS FOR MAY 16
HIGH 90F IN 1951
LOW 30F IN 1936
PRECIP 2.63 INCHES IN 1954
PEAK GUST 56e MPH NW IN 1952

RECORDS FOR MAY 17
HIGH 90F IN 2017
LOW 34F IN 1956, 1957
PRECIP 2.07 INS IN 1916
PEAK GUST 52 MPH SW IN 1967, W IN 1974

TODAY'S REPORT PREPARED BY: Benjamin Turner