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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, JUNE 6, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

SLIGHTLY LOWER HUMIDITY BRINGS IN DRIER WEATHER
AND GREATER VISIBILITY ON THE GREAT BLUE HILL...

Yesterday began with 100% relative humidity, which later dropped
to its lowest observed value at 72%. This resulted in dense fog 
with intermittent rain showers. Yesterday afternoon a passing 
thunderstorm brought measurable precipitation for today's 7 A.M. 
observation. This morning there was 0.19 inches of precipitation 
and overcast skies with a visibility of 35 miles. Skies were still 
overcast by the 10 A.M. observation, with increased visibility at 
70 miles. Cloud cover decreased by the 1 P.M. observation, with a 
mixture of cumulus and stratocumulus. Temperatures still remained below 
seasonable so far today with a high of 61F, which is a 11F degrees
below the daily normal of 72F degrees. Winds remained light, coming 
from the N in the morning, becoming variable in the afternoon.     
    
PRELIMINARY STATS FOR MAY 2018

TEMPERATURE, Deg. F
Avg. Max. 72.2 [+5.9]
Avg. Min. 51.3 [+3.5]
Mean      61.8 [+4.7]
24-hour corrected mean: 61.0
Max. for month: 90F on 3rd
Min. for month: 39F on 1st

HEATING DEGREE DAYS
Total heating units:   154 [-114]
Total for the season:  5847 [-456]
Total for last season: 5662

COOLING DEGREE DAYS
Total cooling units:   62 [+40]
Total for the season:  62 [+38]
Total for last season: 56

PRECIPITATION, Inches
Total: 2.01 ins. [-2.10]
Greatest in 24 hrs: 0.74 ins. on 15th

SNOWFALL, Inches
Total: 0.0 ins. [-0.0]

WIND, mph
Avg. uncorrected wind speed: 10.3
Avg. corrected wind speed: 10.8
Prevailing wind direction: SSW at 14%
Peak gust and direction: 56 W on 5th

SUNSHINE:
Campbell-Stokes card minutes: 13326 minutes of possible 26226 or 51%
Astronomical total minutes: 13831 minutes of possible 27178 or 51%

BHO Warmest May Mean Temperature (24-hour adjusted mean), deg F (1885-2018):

1) 61.5 in 2015
2) 61.4 in 1991
3) 61.0 in 1944
   61.0 in 2018
5) 60.9 in 2010
6) 59.4 in 1911
   59.4 in 1959
8) 59.3 in 1964
   59.3 in 2012

Today's Observations:

7 A.M.
Weather: Overcast stratus 
Temperature: 52F; Dew Point: 49F; Wind: NW at 5 kts
Wind: Light
Sea-level pressure: 29.83 ins. Hg, rising, then more rapidly
Visibility: 35 miles, distant fog in all directions 
6-hr Max temp: 52F
6-hr Min temp: 50F
24-hr Precip: 0.19 ins.
BHO SA 1155 12 OVC 35 102/52/49/3205/983/ DSNT FG ALQDS 
WND LGT/ 8/6// 52027 MANUAL 70019 ASOS 70018 10052 20050

10 A.M.
Weather:Overcast stratus  
Temperature: 54F; Dew Point: 48F; Wind: NE at 3 kts
Wind: Light
Sea-level pressure: 29.88 ins. Hg, rising, then more slowly
Visibility: 70 miles, distant haze in all directions
3-hr Precip: 0.00 ins. 
BHO SA 1455 15 OVC 70 121/54/48/0403/988/ DSNT HZ ALQDS WND 
LGT/ 8/6// 53019

1 P.M.
Weather: Broken stratocumuls, broken cumulus
Temperature: 60F; Dew Point: 51F; Wind: NW at 4 kts
Wind: Light
Sea-level pressure: 29.90 ins. Hg, steady, then increasing
Visibility: 60 miles, distant haze in all directions 
6-hr Max temp: 61F
6-hr Min temp: 52F
6-hr precip: 0.00 ins.
BHO SA 1755 E30 BKN 35 BKN 60 127/60/51/3204/990/ DSNT HZ 
ALQDS WND LGT 8/800 53006 10061 20052

SUMMARY FOR TUESDAY, JUNE 5, 2018

TEMPERATURE (DEGREES F)
MAX.....64   NORMAL.....72
MIN.....47   NORMAL.....54
MEAN....56   NORMAL.....63

DEPARTURE FROM 30-YEAR NORMAL........................-7
TOTAL DEPARTURE FOR THE MONTH........................-11 [-3.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............9   DEPARTURE...........+5
TOTAL HEATING UNITS FOR THE MONTH.............38   DEPARTURE..........+16
TOTAL HEATING UNITS FOR THE SEASON..........5885   DEPARTURE.........-440
TOTAL HEATING UNITS LAST SEASON TO DATE.....5693   DIFFERENCE........+192

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............0   DEPARTURE..........-2
TOTAL COOLING UNITS FOR THE MONTH...............7   DEPARTURE..........-2
TOTAL COOLING UNITS FOR THE SEASON.............69   DEPARTURE.........+36
TOTAL COOLING UNITS LAST SEASON TO DATE........58   DEPARTURE.........+11

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................24  N  AT  2:21 P.M.
                   AERO.........................21  N  AT  2:27 P.M. 
                   ASOS.........................24 NNE AT  2:22 P.M.
                   DAVIS........................23  M  AT  2:15 P.M.** RMY 23
FASTEST MILE FOR YESTERDAY......................16  N  AT  2:16 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...................17  N  AT  2:16 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE..................17  M  AT  2:16 P.M.**
AVERAGE WIND SPEED AND DIRECTION................5.2 NNW
                   ASOS.........................5.8
                   DAVIS........................5.3 
** Davis direction malfunctioning 

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.19  DEPARTURE......+0.02
                         ASOS..............0.18
TOTAL PRECIPITATION FOR THE MONTH..........1.01  DEPARTURE......+0.18
                         ASOS..............1.04  
TOTAL PRECIPITATION FOR THE YEAR..........28.33  DEPARTURE......+5.02
                         ASOS.............29.91

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

5/01 65/39/52/-1/0.00/0.0/625/74    25 WNW AERO 21 WNW RMY 25
5/02 88/59/74/+21/0.00/0.0/584/69   37 WSW AERO 29 WSW RMY 35 
5/03 90/67/79/+26/0.13/0.0/433/51   36 SW  AERO 32 WSW RMY 36  
5/04 84/67/74/+20/0.05/0.0/102/12   39 SSW AERO 37 SSW RMY N/A
5/05 73/54/64/+10/0.00/0.0/615/72   56 W   AERO 55 W   RMY N/A
5/06 65/48/57/+3/0.21/0.0/000/00    24 NE  AERO 18 NE  RMY 21
5/07 62/49/56/+1/0.00/0.0/713/83    26 ENE AERO 22 NE  RMY 24
5/08 73/46/60/+5/0.00/0.0/852/99    25 SSE AERO 21 ESE RMY 23 
5/09 74/48/61/+6/0.00/0.0/768/89    23 ESE AERO 18 ESE RMY 21 
5/10 73/48/61/+6/0.03/0.0/355/41    33 S   AERO 30 S   RMY 32 
5/11 70/51/61/+5/0.00/0.0/703/81    26 WNW AERO 24 NW  RMY 28
5/12 51/47/49/-7/0.19/0.0/000/00    25 E   AERO 23 E   RMY N/A
5/13 58/46/52/-4/T/0.0/392/45       20 S   AERO 17 S   RMY 16 
5/14 73/47/60/+3/T/0.0/551/63       23 S   AERO 18 S   RMY 21
5/15 83/54/69/+12/0.74/0.0/333/38   51 NW  AERO 50 NW  RMY 54 TSTM
5/16 56/49/53/-4/0.00/0.0/272/31    32 ENE AERO 28 ENE RMY 30
5/17 72/51/62/+5/0.02/0.0/000/00    17 SW  AERO 14 SW  RMY N/A
5/18 62/43/53/-5/0.00/0.0/467/53    35 ENE AERO 33 ENE RMY N/A
5/19 57/43/50/-8/0.15/0.0/133/15    22 E   AERO 17 E   RMY N/A
5/20 77/54/66/+8/0.27/0.0/000/00    33 SW  AERO 31 SW  RMY 33 TSTM
5/21 77/52/65/+6/0.00/0.0/861/97    22 W   AERO 18 W   RMY 20
5/22 68/51/60/+1/0.04/0.0/000/00    23 SSW AERO 21 S   RMY 22
5/23 82/51/67/+8/0.06/0.0/677/76    33 NNW AERO 33 NNW RMY 34 TSTM
5/24 74/50/62/+3/0.00/0.0/795/89    28 SSW AERO 25 SSW RMY 27 
5/25 86/50/68/+8/0.00/0.0/779/87    40 W   AERO 39 W   RMY 43
5/26 88/61/75/+15/0.00/0.0/502/56   38 ENE AERO 38 ENE RMY 39
5/27 61/47/54/-6/0.07/0.0/000/00    32 ENE AERO 30 ENE RMY N/A
5/28 60/48/54/-7/0.05/0.0/027/03    23 S   AERO 21 S   RMY N/A
5/29 85/56/71/+10/0.00/0.0/775/86   23 WSW AERO 23 WSW RMY N/A
5/30 72/59/66/+5/0.00/0.0/758/84    21 S   AERO 20 S   RMY 21 
5/31 81/54/68/+7/0.00/0.0/759/84    28 S   AERO 28 S   RMY 29 

PRELIMINARY CLIMATE SUMMARY FOR JUNE CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

6/01 78/62/70/+8/T/.../..            21 S   AERO 21 S   RMY N/A
6/02 79/54/67/+5/0.00/.../..         26 ENE AERO 25 ENE RMY 27
6/03 59/45/52/-10/0.00/.../..        28 ENE AERO 25 ENE RMY N/A  
6/04 52/45/49/-14/.../..../..        29 ENE AERO 26 ENE RMY 29
6/05 64/47/56/-7/..../..../..        24  N  AERO 21  N  RMY 23 TSTM                                  

6/05  Low temp since midnight is 50F; normal low is now 54F

DAILY RECORDS FOR MAY 2018

5/03/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
         BREAKS PREVIOUS RECORD OF 66F SET IN 2001

5/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
         BREAKS PREVIOUS RECORD OF 66F SET IN 2001

DAILY RECORDS FOR JUNE 2018

None so far.

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

RECORDS FOR JUNE 6
HIGH 95F IN 1925
LOW 42F IN 1885, 1894, 1920, 1945
PRECIP 3.61 INS IN 2000
PEAK GUST 58 MPH NE IN 2000

RECORDS FOR JUNE 7
HIGH 93F IN 1999
LOW 40F IN 1932
PRECIP 4.01 INS IN 2006
PEAK GUST 58 MPH NE IN 1982

TODAY'S REPORT PREPARED BY: Kaitlin Geagan/Devin Richardt