BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MAY 17, 2012
ALL TIMES ARE IN EASTERN STANDARD TIME
 
A SUNNY, WARM AND MUCH DRIER DAY TODAY
MINIMUM TEMPERATURE OF 58F TIED RECORD FOR MAY 16  
 
High clouds cleared away early this morning with a very
sunny day today with much drier air. Yesterday's dew points
were in the humid 60's but today have fallen to the very
comfortable 30's by afternoon.
The minimum temperature of 58 degrees on Wednesday equaled
the record high minimum for the date which occurred in
1951 and 1961. 
 
Yesterday brought our first rumbles of thunder for the
first thunderstorm day of 2012. The years of the latest
first thunderstorm occurrences are listed here. The actual
dates of the occurrences have yet to be entered.
 
Latest first T-storm (May or later, listed chronologically):
 
May 16, 2012
May 11, 2007
June 1978
June 1971
May 1968
May 1966
May 1964
June 1960
May 1946
May 1941
May 1937
May 1934
May 1906
May 1903
May 1901
May 1894
May 1892
 
Today's observations:
 
7 A.M.
Weather: Scattered dense cirrus patches, dense cirrostratus
layer NE-S    
Temperature: 54F, Dew Point: 42F; Wind: NW at 9 kts,
Wind: Direction variable W-NNW
Sea-level pressure: 30.01 inches Hg, rising then more rapidly 
Visibility: 60 miles, 70 miles NW 
24-hour rainfall: 0.12 in.
6-hour min. temp: 50F
BHO SA 1155 220 SCT E250 BKN 60 164/54/42/3109/001/
PTCHS DNS CI VC W-N DNS CS LYR XTDNG NE-S RCDNG
CLRG/CLR SKY WSW-NW VSBY NW 70 DSNT HZ
WND 28V34/ 8/008 53027 MANUAL 70012 ASOS 70012
10059 20050
 
10 A.M.
Weather: Clear, cirrus mostly distant NE-S  
Temperature: 61F, Dew Point: 38F; Wind: NW at 9 kts,
Sea-level pressure: 30.06 inches Hg, rising then more slowly
Visibility: 55 miles, distant haze
BHO SA 1455 CLR 55 181/61/38/3209/006/ CI MSTLY DSNT NE-S
DSNT HZ WND 27V36/ 8/001 51017
 
1 P.M. 
Weather: Thin scattered cirrus, few lower cirrus 
Temperature: 68F, Dew Point: 36F; Wind: NW at 10 kts,
Wind: Direction variable WSW-N 
Sea-level pressure: 30.07 inches Hg, rising slightly 
Visibility: 70 miles, distant haze 
6-hour max. temp: 68F
BHO SA 1755 300 –SCT 70 182/68/36/3110/007/ FEW LWR CI AND
CI OVHD-NE-SE-SW WND 25V36/ 8/001 51001 10068 20054
 
WEATHER SUMMARY FOR WEDNESDAY, MAY 16
 
TEMPERATURE (DEGREES F)
MAX.....71    NORMAL.....66
MIN.....58    NORMAL.....48
MEAN....65    NORMAL.....57
 
DEPARTURE FROM 30-YEAR NORMAL........................+8
TOTAL DEPARTURE FOR THE MONTH.......................+17 [+0.9 DEGREE/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE..........-9
TOTAL HEATING UNITS FOR THE MONTH.............148   DEPARTURE.........-26
TOTAL HEATING UNITS FOR THE SEASON...........4862   DEPARTURE.......-1338
TOTAL HEATING UNITS LAST SEASON TO DATE......6071   DIFFERENCE......-1209
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............23 S   AT  8:19 A.M. * 
                   AERO..................24 S   AT  8:19 A.M. 
                   ASOS..................24 S   AT  7:48 P.M. 
                   DAVIS.................24 S   AT  8:19 P.M. RMY N/A
THE FASTEST MILE FOR YESTERDAY...........19 S   AT  7:36 P.M.   
MAXIMUM 2-MINUTE ASOS AVERAGE............18 S   AT  7:48 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE...........18 S   AT  7:36 P.M. 
AVERAGE WIND SPEED AND DIRECTION.......10.2 S 
                   ASOS.................9.9 
                   DAVIS................9.6 S [190 deg.]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.12   DEPARTURE..........+0.00
                         ASOS..............0.12
TOTAL PRECIPITATION FOR THE MONTH..........2.95   DEPARTURE..........+1.00
                         ASOS..............2.87
TOTAL PRECIPITATION FOR THE YEAR..........12.56   DEPARTURE..........-7.94
                         ASOS.............12.60
     
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..........-0.1
TOTAL SNOWFALL FOR THE SEASON..............24.2    DEPARTURE.........-35.9
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2012 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust when significant
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
 
5/1  47/42/45/-8/0.65/0.0/000/00    33 SE  AERO 36 MPH SE  RMY 37
5/2  50/43/47/-6/0.05/0.0/000/00    16 ENE AERO 16 MPH ENE RMY 17
5/3  51/44/48/-5/0.08/0.0/000/00    14 SSE AERO 16 MPH SSE RMY N/A
5/4  56/47/52/-2/0.01/0.0/000/00    21 SSW AERO 25 MPH SSW RMY 23
5/5  57/46/52/-2/0.04/0.0/034/04    14 NE  AERO 15 MPH NE  RMY 15
5/6  58/45/52/-2/0.00/0.0/532/62    21 ENE AERO 21 MPH ENE RMY 21
5/7  67/48/58/+3/0.00/0.0/740/86    23 S   AERO 25 MPH S   RMY 25
5/8  57/48/53/-2/0.18/0.0/000/00    40 S   AERO 46 MPH S   RMY 46
5/9  61/54/58/+3/0.36/0.0/000/00    25 S   AERO 28 MPH S   RMY N/A
5/10 65/46/56/+1/0.98/0.0/234/27    33 W   AERO 36 MPH W   RMY 37
5/11 62/42/52/-4/T/0.0/539/62       30 WNW AERO 33 MPH WNW RMY 34
5/12 77/46/62/+6/0.00/0.0/862/99    30 W   AERO 30 MPH W   RMY 29
5/13 82/57/70/+14/0.00/0.0/314/36   27 S   AERO 29 MPH S   RMY 29
5/14 71/52/62/+5/0.05/0.0/096/11    23 S   AERO 24 MPH S   RMY 23
5/15 72/57/65/+8/0.43/0.0/123/14    32 S   AERO 35 MPH S   RMY 33
5/16 71/58/65/+8/0.12/0.0/141/16    23 S   AERO 24 MPH S   RMY N/A
 
5/17 morning low temp: 50F; the normal low is now 48F
 
DAILY RECORDS FOR MAY 2012
5/16 - Minimum temperature of 56F equals record high minimum
      for the date set in 1951 and 1961
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 17
HIGH 88F IN 1974, 1977
LOW 34F IN 1956, 1957
PRECIP 2.07 INS IN 1916
PEAK GUST 52 MPH SW IN 1967, W IN 1974
 
RECORDS FOR MAY 18
HIGH 88F IN 1906, 1936, 1986
LOW 35F IN 2002
PRECIP 1.93 INS IN 2007
SNOW TRACE IN 2002 (Ice pellets)
PEAK GUST 64 MPH SSW IN 2000
 
TODAY'S REPORT PREPARED BY: Robert Skilling/ William Wilson