BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY MAY 14, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

AIRMASS DRYING OUT TODAY AFTER HIGH HUMIDITY
DEW POINTS DROP FROM 60F YESTERDAY TO 40'S TODAY
SMALL AMOUNT OF RAINFALL 0.21 INCH WITH COLD FRONT
 
After the most humid conditions of the year and month
today yesterday and wind shift with a cold front passage
overnight brought in much drier air today.  Dew points 
went down from near 60F late yesterday through the 50's
to 40's early today.  The wind shifted from south to
west and west-northwest.
Only a small amount of rainfall accompanied the air mass
change with just 0.21 inch measured for the 24 hours
ending at 7:00 A.M. this morning.  
 
Today's Observations:
 
7 A.M.
Weather: Clear, cirrus ENE-SS, receding
Temperature: 59F; Dew Point: 55F; Wind: WNW at 7 kts
Sea-level pressure: 29.75 ins. Hg, rising then falling but higher
than 3 hours ago
Visibility: 35 miles, except 45 miles WNW, light distant haze
6-hr Max temp: 59F
6-hr Min temp: 54F
24-hr precip: 0.21 in.
BHO SA 1155 CLR 35 074/59/55/2907//975/ CI DSNT ENE-SSE RCDNG VSBY 
WNW 45 THN DSNT FG/ 8/001 50007 ASOS 70017 MANUAL 70021 10059 20054
 
10 A.M.
Weather:  Clear, few small cumulus fractus and cumulus forming,
cirrus layer SW-NW below 45 deg. advancing
Temperature: 68F; Dew Point: 45F; Wind: WSW AT 4 kts (estimated)
Wind: Light
Sea-level pressure: 29.73 ins. Hg, falling, then more quickly
Visibility: 40 miles, except 45 miles WNW, light distant haze
BHO SA 1455 CLR 40 067/68/45/E2404/973/ FEW SML CUFRA/CU FRMG
CI LYR DSNT SW-NW ADVCNG VSBY WNW 45 LGT DSNT HZ WND LGT/
8/105 58007
 
1 P.M.
Weather: Scattered dense cirrus, thin broken cirrus and thin 
overcast cirrus 
Temperature: 76F; Dew Point: 42F; Wind: WSW at 9G18 kts
Sea-level pressure: 29.67 ins. Hg, falling, then more rapidly
Visibility: 40 miles, except 50 miles WNW, distant haze
6-hr Max temp: 76F
6-hr Min temp: 59F
BHO SA 1755 220 SCT 250 -BKN 300 -OVC 40 049/76/42/2509G18/967/ 
PTCHS DNS CI VSBY WNW 50 LGT DSNT HZ ALQDS WND 18V27/ 8/002 58018 
10076 20059

SUMMARY FOR FRIDAY, MAY 13, 2016
  
TEMPERATURE (DEGREES F)
MAX.....74   NORMAL.....66
MIN.....52   NORMAL.....47
MEAN....63   NORMAL.....56
 
DEPARTURE FROM 30-YEAR NORMAL..........................+7
TOTAL DEPARTURE FOR THE MONTH.........................-34 [-2.8 DEGREES/DAY]
 
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............2   DEPARTURE.........,-7
TOTAL HEATING UNITS FOR THE MONTH.............170   DEPARTURE.........+28
TOTAL HEATING UNITS FOR THE SEASON...........5162   DEPARTURE.......-1015
TOTAL HEATING UNITS LAST SEASON TO DATE......6332   DIFFERENCE......-1170  
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY...................27 S   AT  2:51 P.M.     
                   ASOS........................27 S   AT  2:51 P.M.  
                   DAVIS.......................27 S   AT  2:50 P.M. RMY 26
FASTEST MILE FOR YESTERDAY.....................20 S   AT  2:42 P.M.   
MAXIMUM 2-MINUTE ASOS AVERAGE..................21 S   AT  2:43 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................19 SSE AT  1:21 P.M.  
AVERAGE WIND SPEED AND DIRECTION...............11.7 S
                   ASOS........................12.0
                   DAVIS.......................10.9 S [190 Deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.21  DEPARTURE......+0.09
                         ASOS..............0.17
TOTAL PRECIPITATION FOR THE MONTH..........1.88  DEPARTURE......+0.29
                         ASOS..............1.76
TOTAL PRECIPITATION FOR THE YEAR..........18.82  DEPARTURE......-1.41
                         ASOS.............18.76
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST) 
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........0.0
TOTAL SNOWFALL FOR THE MONTH..............TRACE  DEPARTURE........0.0
TOTAL SNOWFALL FOR THE SEASON..............57.5  DEPARTURE.......-5.7
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 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
 
5/1 52/39/46/-7/0.08/T/000/00               21 S   AERO 22 SE  RMY 20
5/2 50/41/46/-7/0.31/0.0/000/00             20 NE  AERO 21 NE  RMY 18
5/3 48/43/46/-7/0.16/0.0/000/00             16 E   AERO 16 E   RMY 17
5/4 48/41/45/-9/0.53/0.0/000/00             33 NE  AERO 35 NE  RMY 34
5/5 44/41/43/-11/0.30/0.0/000/00            39 NNE AERO 41 NNE RMY 39
5/6 54/43/49/-5/0.13/0.0/.../..             28 ENE AERO 29 N   RMY 26
5/7 51/43/47/-8/.../0.0/.../..              25 NE  AERO 25 NE  RMY 23
5/8 60/46/53/-2/.../0.0/.../..              47 W   AERO 53 W   RMY 49        
5/9 65/43/54/-1/0.00/0.0/.../..             40 W   AERO 44 W   RMY 40
5/10 69/40/55/0/0.00/0.0/.../..             22 W   AERO 25 WNW RMY 22
5/11 76/50/63/0.00/0.0/.../..               22 WNW AERO 23 WNW*RMY 22
5/12 75/54/65/0.00/0.0/.../..               23 NNE AERO 25 S   RMY 23
5/13 74/52/63/+7/0.21/0.0/.../..            27 S   AERO 27 S   RMY 26 
 
5/14 low temp since midnight is 54F; normal low now 47F
 
*last of several occurrences
    
DAILY RECORDS FOR MAY 2016
 
5/1/16: DAILY RECORD SNOWFALL OF A TRACE,
TIES PREVIOUS RECORDS SET IN 1905, 1917, 1921, and 1995
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 14
HIGH 85F IN 1961
LOW 33F IN 1895
PRECIP 1.93 INCHES IN 2006
PEAK GUST 53 MPH S IN 2009
 
RECORDS FOR MAY 15
HIGH 93F IN 1900
LOW 36F IN 1947,1985
PRECIP 1.63 INCHES IN 1978
PEAK GUST 53e MPH NE IN 1978, W 2002
 
TODAY'S REPORT PREPARED BY: Robert Skilling