BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 6, 2012
ALL TIMES ARE IN EASTERN STANDARD TIME
 
A LITTLE LATE AFTERNOON SUNSHINE SATURDAY 
LOWEST AVERAGE WIND SPEED IN RECORDS BACK TO 2000
LOW CLOUDS CLEAR BRIEFLY AFTER SUNRISE THIS MORNING
 
The sun made its first appearance during the month of
May to date late yesterday afternoon.
 
In our long term record hourly average wind speeds
are corrected up 1 MPH when speeds drop to 10 MPH
or less to account for inertia (drag) on the 3-cup
anemometer as has been used throughout the whole
period of record here at Blue Hill.
 
Only 94 miles (uncorrected) of wind blew passed the
Observatory yesterday for an uncorrected daily average
wind speed of 3.9 NE (uncorrected) as registered on our
contacting wind system.  This surpasses the previous
low wind day of 4.0 WNW on January 22, 2007, in records
checked back to 2000. (records are uncorrected for low winds)
The wind average for May has now dropped to
7.3 MPH with two days so far this month averaging
below 5 MPH. 
 
After brief clearing this morning low clouds moved back
in within a couple of hours and we continue with what has
so far been a nearly sunless month of May.
 
 
Today's observations:
 
7 A.M.
Weather: Scattered altocumulus, stratus, stratus fractus layer S-NW,
stratocumulus, few stratocumulus and altocumulus castellanus distant
WNW-NNE-ESE, fog S-NW, partial undercast dissipated past hour
Temperature: 51F, Dew point: 49F, Wind: ENE at 5 kts
Sea-level pressure: 29.98 inches Hg, rising
Visibility: 12 miles, thin fog, except 6 miles fog, SW-NW,
visibility NE-SE 15 miles, partial undercast dissipated past hour
24-hour precip: trace
6-hour min. temp: 45F
BHO SA 1155 90 SCT 12 196/51/49/0705/011/ STRA/STFRA LYR S-NW SC/
FEW SCC AND ACC DSNT WNW-N-ESE VSBY S-NW 6 FG NE-SE 15 CLRG PST HR
PARTIAL UNDRCST DSSPTD/ 8/680 51010 10051 20045
 
10 A.M.
Weather: Scattered low cumulus, overcast stratocumulus,
higher clouds visible, virga, dark cloud bases distant WNW,
few bright spots in the overcast, higher clouds visible
Temperature: 51F, Dew Point: 46F; Wind: NE at 8 kts,
Wind: Direction variable N-E
Sea-level pressure: 30.14 inches Hg, rising then more rapidly 
Visibility: 50 miles except 40 miles W-WNW
BHO SA 1455 10 SCT E30 OVC 50 208/51/46/0408/014/ VIRGA/DRK CLD BASES
DSNT WNW FEW BRGHT SPTS IOVC HIER CLDS VSB VSBY W-WNW 40 36V09/ 8/8//
53012
 
WEATHER SUMMARY FOR SATURDAY, MAY 5
 
TEMPERATURE (DEGREES F)
MAX.....57    NORMAL.....63
MIN.....46    NORMAL.....45
MEAN....52    NORMAL.....54
 
DEPARTURE FROM 30-YEAR NORMAL.......................-2
TOTAL DEPARTURE FOR THE MONTH......................-23 [-4.8 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY..............13   DEPARTURE..........+1
TOTAL HEATING UNITS FOR THE MONTH..............81   DEPARTURE.........+18
TOTAL HEATING UNITS FOR THE SEASON...........4795   DEPARTURE.......-1294
TOTAL HEATING UNITS LAST SEASON TO DATE......5946   DIFFERENCE......-1151
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............14 NE  AT  4:23 P.M. *
                   AERO..................15 NE  AT  3:37 P.M.
                   ASOS..................15 NE  AT  4:24 P.M.
                   DAVIS.................15 NE  AT  4:23 P.M. RMY 15
THE FASTEST MILE FOR YESTERDAY............9 NE  AT  4:17 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............10 ENE AT  4:24 P.M.
DAVIS MAXIMUM 2-MINUTE AVERAGE...........10 NE  AT  3:37 P.M.
AVERAGE WIND SPEED AND DIRECTION........3.9 NE 
                   ASOS.................3.2
                   DAVIS................3.7 NE[050 deg.]
* last of several occurrences....
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....TRACE  DEPARTURE..........-0.13
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.83   DEPARTURE..........+0.21
                         ASOS..............0.81
TOTAL PRECIPITATION FOR THE YEAR..........10.44   DEPARTURE..........-8.73
                         ASOS.............10.54
     
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/.../0.0/000/00     21 SSW AERO 25 MPH SSW RMY 23
5/5  57/46/52/-2/.../0.0/.../..     14 NE  AERO 15 MPH NE  RMY 15
 
5/6 morning low temp: 45F; the normal low is now 45F
 
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 6
HIGH 90F IN 1930
LOW 29F IN 1891
PRECIP 1.04 INCHES IN 1890
SNOWFALL TRACE IN 1917,1996
PEAK GUST 65 MPH SSE IN 1989
 
RECORDS FOR MAY 7
HIGH 93F IN 1930
LOW 33F IN 1970
PRECIP 1.19 INCHES IN 2005
SNOWFALL TRACE IN 1967
PEAK GUST 66e MPH WNW IN 1940
 
TODAY'S REPORT PREPARED BY: Robert Skilling