BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, MAY 16, 2012
ALL TIMES ARE IN EASTERN STANDARD TIME
 
UNSEASONABLY WARM, HUMID AIR MASS IN PLACE
TWO DAY RAINFALL TOTALS OVER HALF INCH AND
INCLUDED THE  YEAR'S FIRST THUNDERSTORM
 
Yesterday's minimum temperature of 57F was just one
degree shy of the record high minimum for May 15 and
this morning's low of 60F would be a new record high
minimum for May 16 if it should hold through midnight.
The record high minimum is 58F in 1951, 1961.
Rain and showers which began yesterday afternoon and
continued until late evening netted 0.43 inch of rain-
fall. 
 
An additional 0.12 inch of rain fell this morning
and included a very brief thunderstorm, the year's
first, although it was just one rumble heard in clouds to
the southeast and south at 8:03 a.m. EDT.  The
latest occurrences for a thunderstorm in any year
on record is estimated to be May 18 so this year's
first occurrence comes very close to the record late
date.
 
The air has become quite moist or humid with dew points
rising into the 60's today. 
 
Today's observations:
 
7 A.M.
Weather:  Obscurement, light rain and heavy fog,
rain began 6:40 A.M. EST 
Temperature: 60F, Dew Point: 60F; Wind: SSE at 5 kts
Sea-level pressure: 30.17 inches Hg, rising then steady
Visibility: 1/16 mile, heavy fog, light rain occurring
6-hour rainfall: trace 
24-hour rainfall: 0.43 in.
6-hour min. temp: 60F
BHO SA 1155 W2 X 1/16R-F 137/60/60/1605/994/ RB40/ 8//// 55001
MANUAL 6000/ ASOS 60000 MANUAL 70043 ASOS 70042 10060 20060
 
10 A.M. 
Weather: Obscurement with heavy fog, rain ended 9:45 a.m.
Temperature: 62F, Dew Point: 62F; Wind: S at 8 kts,
Sea-level pressure: 29.91 inches Hg, falling then more rapidly
Visibility: 1/16 mile
3-hour precip: 0.12 inch
BHO SA 1455 W2 X 1/16F 130/62/62/1908/991/ WND GRDLY VEERING/
RELB30 PCPN VRY LGT/ 8//// 58007 ASOS 60012 MANUAL 6012/
 
1 P.M. 
Weather: Low overcast stratus 
Temperature: 65F, Dew Point: 63F; Wind: SSW at 8 kts
Sea-level pressure: 29.89 inches Hg, falling then more rapidly
Visibility: 25 miles, except 30 miles E-S and 20 miles, W-N,
light distant fog 
6-hour precip: 0.12 inch
6-hour max. temp: 65F
BHO SA 1755 E6 OVC 25 122/65/63/2108/989/ VSBY E-S 30 W-N 20 
THN LGT DSNT F/ 8/6// 58008 MANUAL 6012/ ASOS 60012 10065 20060
 
WEATHER SUMMARY FOR TUESDAY, MAY 15
 
TEMPERATURE (DEGREES F)
MAX.....72    NORMAL.....66
MIN.....57    NORMAL.....48
MEAN....65    NORMAL.....57
 
DEPARTURE FROM 30-YEAR NORMAL........................+8
TOTAL DEPARTURE FOR THE MONTH........................+9 [+0.4 DEGREE/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE..........-9
TOTAL HEATING UNITS FOR THE MONTH.............148   DEPARTURE.........-17
TOTAL HEATING UNITS FOR THE SEASON...........4862   DEPARTURE.......-1329
TOTAL HEATING UNITS LAST SEASON TO DATE......6052   DIFFERENCE......-1190
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............32 S   AT 10:02 A.M.
                   AERO..................35 S   AT 10:02 A.M.
                   ASOS..................33 S   AT 11:08 A.M.
                   DAVIS.................32 S   AT 10:01 A.M. RMY 33
THE FASTEST MILE FOR YESTERDAY...........25 S   AT 11:17 A.M. *  
MAXIMUM 2-MINUTE ASOS AVERAGE............24 S   AT 11:18 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE...........23 SSE AT 10:59 A.M.
AVERAGE WIND SPEED AND DIRECTION.......14.5 S
                   ASOS................13.5
                   DAVIS...............13.3 S [170 deg.]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.43   DEPARTURE..........+0.31
                         ASOS..............0.42
TOTAL PRECIPITATION FOR THE MONTH..........2.83   DEPARTURE..........+1.00
                         ASOS..............2.75
TOTAL PRECIPITATION FOR THE YEAR..........12.44   DEPARTURE..........-7.94
                         ASOS.............12.48
     
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/.../..    33 W   AERO 36 MPH W   RMY 37
5/11 62/42/52/-4/T/0.0/.../..       30 WNW AERO 33 MPH WNW RMY 34
5/12 77/46/62/+6/0.00/0.0/.../..    30 W   AERO 30 MPH W   RMY 29
5/13 82/57/70/+14/0.00/0.0/.../..   27 S   AERO 29 MPH S   RMY 29
5/14 71/52/62/+5/0.05/0.0/.../..    23 S   AERO 24 MPH S   RMY 23
5/15 72/57/65/+8/0.43/0.0/.../..    32 S   AERO 35 MPH S   RMY 33
 
5/16 morning low temp: 60F; the normal low is now 48F
 
DAILY RECORDS FOR MAY 2012
None so far.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 16
HIGH 90F IN 1951
LOW 30F IN 1936
PRECIP 2.63 INCHES IN 1954
PEAK GUST 56e MPH NW IN 1952
 
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
 
TODAY'S REPORT PREPARED BY: Robert Skilling