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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 8, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

A DRY, CALM AND CLEAR DAY ON GREAT BLUE HILL....

Winds throughout the day were light and variable, being
completely calm at 7 A.M. A thick layer of fog that obscured
most of Boston migrated offshore by the 10 P.M. observation.
The relative humidity has decreased since this morning, and 
it was observed at 31 percent when last checked. Visibility has
been obscured by either fog early in the day, or a thin smoke
layer later on. The farthest visibility observed was 40 miles.
Skies were clear other than a few cumulus clouds.Temperatures
have reached 70F so far today, 6 degrees above the daily normal 
of 64F. The low since midnight was 46F, just one degree above 
the normal minimum.  

PRELIMINARY STATS FOR APRIL 2018
 
TEMPERATURE, Deg. F
Avg. Max. 52.4 [-3.3]
Avg. Min. 34.9 [-2.8]
Mean      43.7 [-3.0]
24-hour corrected mean: 43.1
Max. for month:  73F on 28th
Min. for month:  24F on  9th
 
HEATING DEGREE DAYS
Total heating units:    635  [+84]
Total for the season:  5693 [-342]
Total for last season: 5333

PRECIPITATION, Inches
Total: 6.51 [+1.96]
Greatest in 24 hrs: 2.85 on the 15-16th 

SNOWFALL, Inches
Total: 2.6 [-0.4]
Greatest in 24 hrs: 1.6 in. on 2nd
 
WIND, mph
Avg. uncorrected wind speed: 12.2
Avg. corrected wind speed: 12.6
Prevailing wind direction: WNW at 16%
Peak gust and direction: 56 NW on the 4th 
 
SUNSHINE:
Campbell-Stokes card minutes: 9744 minutes of possible 23250 or 42%
Astronomical total minutes: 10085 minutes of possible 24105 or 42%

Today's Observations:

7 A.M.
Weather: Few cumulus   
Temperature: 54F; Dew Point: 50F; Wind: Calm 
Sea-level pressure: 30.29 ins. Hg, rising then steady     
Visibility: 20 miles, distant fog in all directions
6-hr Max temp: 54F
6-hr Min temp: 46F
24-hr precip:  0.00 ins. 
24-hr snowfall: 0.0 ins.  
Snow depth: 0 ins.
BHO SA 1155 CLR 20 259/54/50/0000/029/ DSNT FG ALQDS 
FEW CU ALQDS WND CALM/ 8/100 51015 10054 20046   

10 A.M.
Weather: Clear, few cumulus SE-NW
Temperature: 65F; Dew Point: 46F; Wind: SE at 2 kts,
Wind: Light and variable 
Sea-level pressure: 30.30 ins. Hg, rising then falling   
Visibility: 40 miles, except 20 NE, distant fog offshore 
3-hr precip: 0.00 ins.  
3-hr snowfall: 0.0 ins.
BHO SA 1455 CLR 40 263/65/46/1302/030/ DSNT FG OFFSHR FEW CU 
SE-NW VSBY NE 20 WND L/V/ 8/100 50004

1 P.M.
Weather: Scattered cumulus  
Temperature: 70F; Dew Point: 38F; Wind: SSW at 4G12 kts,
Wind: Light
Sea-level pressure: 30.26 ins. Hg, falling then steady
Visibility: 40 miles, thin smoke layer in all directions 
6-hr Max temp: 70F
6-hr Min temp: 56F
6-hr precip:   0.00 ins
6-hr snowfall: 0.0 ins.   
Snow depth: 0 ins.
BHO SA 1755 40 SCT 247/70/38/2004G12/026/ THN K LYR ALQDS WND LGT/ 
8/100 56016 10071 20056  
 
SUMMARY FOR MONDAY, MAY 7, 2018

TEMPERATURE (DEGREES F)
MAX.....62   NORMAL.....64
MIN.....49   NORMAL.....45
MEAN....56   NORMAL.....55

DEPARTURE FROM 30-YEAR NORMAL..........................+1 
TOTAL DEPARTURE FOR THE MONTH.........................+80 [+11.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............9   DEPARTURE..........-1
TOTAL HEATING UNITS FOR THE MONTH.............31   DEPARTURE.........-51
TOTAL HEATING UNITS FOR THE SEASON..........5724   DEPARTURE........-393
TOTAL HEATING UNITS LAST SEASON TO DATE.....5420   DIFFERENCE.......+304

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............0   DEPARTURE...........0
TOTAL COOLING UNITS FOR THE MONTH..............32   DEPARTURE.........+30
TOTAL COOLING UNITS FOR THE SEASON.............32   DEPARTURE.........+29
TOTAL COOLING UNITS LAST SEASON TO DATE........20   DEPARTURE.........+12

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................26 NE  AT 12:06 P.M. 
                   AERO........................22 NE  AT 11:56 P.M. 
                   ASOS........................26 NE  AT 11:12 A.M.
                   DAVIS.......................25 M   AT 11:12 A.M.** RMY 24
FASTEST MILE FOR YESTERDAY.....................17 NE  AT 11:52 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................17 ENE AT 11:48 A.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE.................17 M   AT 11:41 A.M.**
AVERAGE WIND SPEED AND DIRECTION..............8.3 NE
                   ASOS.......................8.4 
                   DAVIS......................8.4 M**

** Davis direction malfunctioning 

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE......-0.13
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.39  DEPARTURE......-0.48
                         ASOS..............0.37  
TOTAL PRECIPITATION FOR THE YEAR..........25.70  DEPARTURE......+6.43
                         ASOS.............27.29

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..............92.8  DEPARTURE.......+30.0

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
*   : Estimated data 

4/01 58/33/46/+5/0.00/0.0/336/44   45 SSW AERO 43 SSW RMY N/A  
4/02 38/30/34/-7/0.13/1.6/077/10   20 SSW AERO 15 SSW RMY 17
4/03 48/30/39/-3/0.54/0.0/238/31   28 SSE AERO 25 SSE RMY 25
4/04 54/36/45/+3/0.21/0.0/000/00   56 WNW AERO 56 WNW RMY 54
4/05 40/27/34/-9/0.00/0.0/760/98   53 WNW AERO 53 WNW RMY 52 
4/06 41/25/33/-10/0.25/1.0/156/20  37 S   AERO 36 S   RMY 38
4/07 46/32/35/-4/0.00/0.0/312/40   32 WNW*AERO 35 WNW RMY 34
4/08 41/29/35/-9/0.00/0.0/290/37   35 WNW*AERO 31 WNW RMY 34
4/09 45/24/35/-9/0.00/0.0/715/01   28 WNW AERO 25 WNW RMY 29
4/10 39/31/35/-10/T/T/000/00       14 SSW AERO 13 SSW RMY N/A
4/11 48/29/39/-6/T/0.0/364/46      24 SSE AERO 23 SSE RMY 25 
4/12 61/33/47/+2/0.03/0.0/500/63   39 SSW AERO 38 SSW RMY 41 
4/13 65/47/56/+10/T/0.0/096/12     37 SSW AERO 37 SSW RMY N/A
4/14 51/36/44/-2/0.00/0.0/328/41   33 ENE AERO 31 ENE RMY N/A
4/15 36/30/33/-14/0.32/T/000/00    39 ENE AERO 39 ENE RMY N/A
4/16 55/32/44/-3/2.63/000/00       41 ENE AERO 43 ENE RMY 41
4/17 48/36/42/-5/0.00/0.0/210/26   37 W   AERO 33 W   RMY 37
4/18 53/32/43/-5/0.00/0.0/633/78   35 W   AERO 31 W   RMY 34
4/19 41/34/38/-10/0.22/T/000/00    28 WNW AERO 25 WNW RMY N/A 
4/20 52/31/42/-7/0.00/0.0/522/64   34 NW  AERO 33 NW  RMY 36
4/21 60/33/47/-2/0.00/0.0/811/99   28 NW  AERO 26 NW  RMY 29
4/22 61/36/49/0/0.00/0.0/821/100   25 NW  AERO 24 NW  RMY 26 
4/23 62/40/51/+1/0.00/0.0/816/99   25 S   AERO 25 S   RMY 26
4/24 67/39/53/+3/0.00/0.0/645/78   31 S   AERO 29 S   RMY 32
4/25 57/47/52/+2/0.94/0.0/000/00   32 SE  AERO 32 SE  RMY 33 
4/26 66/48/57/+6/0.28/0.0/308/37   36 WNW AERO 35 WNW RMY 37 
4/27 60/45/53/+2/0.55/0.0/192/23   18 W   AERO 15 W   RMY N/A
4/28 73/47/60/+8/0.00/0.0/711/85   25 S   AERO 21 S   RMY 25
4/29 59/38/49/-3/0.04/0.0/227/27   32 SW  AERO 26 SW  RMY 31
4/30 46/36/41/-11/0.37/0.0/017/02  23 WSW AERO 16 WSW RMY N/A

DAILY RECORDS FOR APRIL 2018

4/16/18: NEW DAILY RECORD MAXIMUM PRECIPITATION OF 2.63 INS.
         PREVIOUS RECORD WAS 2.45 INS. SET IN 1929

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

5/1 65/39/52/-1/0.00/0.0/.../..    25 WNW AERO 21 WNW RMY 25
5/2 88/59/74/+21/0.00/0.0/.../..   37 WSW AERO 29 WSW RMY 35 
5/3 90/67/70/+26/..../0.0/.../..   36 SW  AERO 32 WSW RMY 36  
5/4 84/67/74/+20/..../0.0/.../..   39 SSW AERO 37 SSW RMY N/A
5/5 73/54/64/+10/0.00/0.0/.../..   56 W   AERO 55 W   RMY N/A
5/6 65/48/57/+3/0.21/0.0/.../..    24 NE  AERO 18 NE  RMY 21
5/7 62/49/56/+1/0.00/0.0/.../..    26 ENE AERO 22 NE  RMY 24

5/8 Low temp since midnight is 46F; normal low is now 45F

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

RECORDS FOR MAY 8
HIGH 89F IN 2000
LOW 29F IN 1956
PRECIP 1.48 INCHES IN 1886
SNOWFALL TRACE IN 1898, 1947
PEAK GUST 68e MPH NNW IN 1943

RECORDS FOR MAY 9
HIGH 93F IN 2000
LOW 31F IN 1947
PRECIP 2.72 INCHES IN 1954
SNOWFALL 5.0 INS IN 1977 (RECORD FOR MAY)
PEAK GUST 70e MPH NE IN 1977

TODAY'S REPORT PREPARED BY: Benjamin Turner