BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, APRIL 17, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME
 
THE STRONG SOUTH WINDS OF TUESDAY GUSTED TO 45 MPH
CLOUDS CLEAR AWAY EARLY THIS MORNING
TEMPERATURES RISING INTO THE 60'S
 
The strong south winds which began averaging over 20 MPH
around noon yesterday reached hourly speeds of 28 to
29 MPH in the afternoon and evening.  The fastest
sustained winds were 33 MPH with gusts to 45 mph.
The strong winds diminished quickly in the very early
morning hours while veering to W and NW. 
 
Early morning clouds quickly cleared away and left
us with complete sunshine and temperatures rising
into the 60's with gentle NW-NNW winds. The air
continued to dry out after some light showers passed
just to the east of Blue Hill early this morning
and dew points were dropping into the lower 30's to
the upper 20's.  This was producing relative humidities
which fell into the 20 per cent range making for quite
a dry day.
 
Spectacular visibility over 80 miles has developed in
the increasingly dry air today with dew points down
to 26F and relative humidity of 24% at 2 P.M. EDT
 
Today's observations:
 
7 A.M.
Weather: Scattered altocumulus, lenticularis and few
castellanus, layer E-SW receding, few stratocumulus
distant W-WNW, light showers of rain moved ESE passing
in the vicinity of station to the east and southeast  
Temperature: 53F; Dew Point: 38F; Wind: NW at 12 kts,
Wind: Direction variable WSW-N
Sea-level pressure: 30.16 ins. Hg, rising then rising
more rapidly
Visibility: 70 miles, light distant haze
6-hour min. temp: 51F
BHO SA 1155 100 SCT 70 212/53/38/3212/016/ FEW SC DSNT W-NW
AC/FEW LWR AC/ACC/FEW ACSL LYR RCDG E-SW DRK SKY DSNT ESE-S
FEW -SHRA VC E-SE PST HR MOVD ESE VSBY ESE-S 30 HAZY
LGT DSNT HZ SW-NW-NE WND 24V35/ 8/580 53017 10055 20051
 
10 A.M. 
Weather: Clear, few small cumulus forming WSW, layer of
altocumulus and altocumulus lenticularis distant ESE-S
along the horizon, cirrus distant E-S-SW 
Temperature: 58F; Dew Point: 32F; Wind: NNW at 10 kts,
Wind: Direction variable WSW to N
Sea-level pressure: 30.19 ins. Hg, rising then more slowly
Visibility: 80 miles
BHO SA 1455 CLR 80 225/58/32/3310/019/ FEW SML CU FRMG WSW AC/ACSL LYR
DSNT ESE-S ALG HRZN CI DSNT E-S-SW WND 25V36/ 8/141 51013 
 
1 P.M.
Weather: Clear, few small cumulus dissipated during the
observation period, cirrus distant SE-SW
Temperature: 64F; Dew Point: 26F; Wind: NW at 7 kts,
Wind: Direction variable WSW-N
Sea-level pressure: 30.18 ins. Hg, falling slightly
Visibility: 85 miles
6-hour max temp: 64F
BHO SA 1755 CLR 85 221/64/26/3207/018/ FEW SML CU DSSPTD S
CI DSNT SE-SW WND 24V01/ 8/001 58004 10064 20053
 
WEATHER SUMMARY FOR TUESDAY, APRIL 16
 
TEMPERATURE (DEGREES F)
MAX.....62     NORMAL.....56
MIN.....38     NORMAL.....38                         
MEAN....50     NORMAL.....47  
 
DEPARTURE FROM 30-YEAR NORMAL....................+3
TOTAL DEPARTURE FOR THE MONTH...................+13 [+0.6 DEGREE/DAY]
 
HEATING DEGREE DAYS 
TOTAL HEATING UNITS FOR YESTERDAY............15   DEPARTURE..........-3
TOTAL HEATING UNITS FOR THE MONTH...........324   DEPARTURE.........-13
TOTAL HEATING UNITS FOR THE SEASON.........5344   DEPARTURE........-476
TOTAL HEATING UNITS LAST SEASON TO DATE....4543   DIFFERENCE.......+801
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY...............44 S   AT  2:54 P.M.
                   AERO....................40 S   AT  3:31 P.M.  
                   ASOS....................44 S   AT  3:04 P.M.
                   DAVIS...................43 S   AT  3:03 P.M. RMY: 45
THE FASTEST MILE FOR YESTERDAY.............33 S   AT  5:17 P.M. * 
MAXIMUM 2-MINUTE ASOS AVERAGE..............33 SSW AT  5:24 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.............33 S   AT  2:53 P.M.
AVERAGE WIND SPEED AND DIRECTION.........20.4 S 
                   ASOS..................20.3
                   DAVIS.................18.5 S [190 deg]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE...........-0.15
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.18  DEPARTURE...........-1.48
                         ASOS..............1.13
TOTAL PRECIPITATION FOR THE YEAR..........15.27  DEPARTURE...........-1.39
                         ASOS..............N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals
                       
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0   DEPARTURE............-0.1
TOTAL SNOWFALL FOR THE MONTH.............Trace   DEPARTURE............-2.3
TOTAL SNOWFALL FOR THE SEASON.............99.0   DEPARTURE...........+37.0
 
PRELIMINARY CLIMATE SUMMARY FOR APRIL 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
4/1  61/31/46/+5/0.34/0.0/458/60     40 W   AERO 44 MPH WNW RMY 46  TSTM
4/2  40/27/34/-7/T/T/460/60          45 W   AERO 42 MPH W   RMY 47
4/3  45/27/36/-6/0.00/0.0/755/98     44 W   AERO 43 MPH W   RMY 47
4/4  55/26/41/-1/0.00/0.0/719/93     30 WSW AERO 27 MPH WSW RMY 31
4/5  59/36/48/+5/0.00/0.0/403/52     33 NNW AERO 28 MPH NNW RMY 38
4/6  47/30/39/-4/0.00/0.0/747/96     38 NW  AERO 35 MPH NW  RMY 40 
4/7  52/31/42/-1/0.00/0.0/391/50     51 S   AERO 46 MPH S   RMY 50
4/8  65/43/54/+10/T/0.0/494/63       29 SSW AERO 22 MPH SSW RMY N/A
4/9  72/44/58/+14/T/0.0/456/58       35 WNW AERO 35 MPH WNW RMY 39  TSTM
4/10 64/43/54/+9/0.13/0.0/426/54     23 SE  AERO 20 MPH SE  RMY 25
4/11 52/40/46/+1/0.09/0.0/.../..     18 ENE AERO 14 MPH ENE RMY N/A
4/12 40/34/37/-8/0.58/T/000/00       38 E   AERO 32 MPH E   RMY 41
4/13 52/34/43/-3/0.04/0.0/128/16     31 NNE AERO 27 MPH NNE RMY 21
4/14 52/36/44/-2/0.00/0.0/216/27     31 WNW AERO 27 MPH WNW RMY 32
4/15 55/35/45/-2/0.00/0.0/.../..     21 ESE AERO 15 MPH S   RMY N/A
4/16 62/38/50/+3/0.00/0.0/.../..     44 S   AERO 40 MPH S   RMY 45
 
4/17 morning low temp: 51F; the normal low is now 38F
 
DAILY RECORDS FOR APRIL 2013
None so far.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR APRIL 17
HIGH 93 IN 2002
LOW 21 IN 1908
PRECIP 1.68 IN 1954
SNOWFALL 1.0 IN. IN 1899
PEAK GUST 63 MPH ESE IN 2011
 
RECORDS FOR APRIL 18
HIGH 92 IN 1976
LOW 23 1887
PRECIP 1.48 IN 1954
SNOWFALL 3.7 IN. IN 1965
PEAK GUST 59 MPH S IN 1982
 
TODAY'S REPORT PREPARED BY: Robert Skilling/Peter Volpe