BLUE HILL METEOROLOGICAL OBSERVATORY 
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 30, 2011 MEMORIAL DAY
ALL TIMES ARE IN EASTERN STANDARD TIME
 
WARM AND VERY HUMID WEATHER CONTINUES...
PAST SIX DAYS AVERAGE 63% OF POSSIBLE SUNSHINE
MONTHLY PERCENTAGE UP FROM 29% TO 37% SINCE 23RD
AREA OF SHOWERS PASSES TO OUR SOUTH THIS MORNING
 
Unseasonably warm and very humid late May weather
continues today with the past six days averaging
some 10 degrees warmer than normal. The May average
is now above normal after being below much of the
month.
 
Sunshine has been increasing each day starting with 
the 24th and has reached 37% of possible through the
29th. It appears that May will run close to a tie for
7th cloudiest or might even go down to 8th place.
 
A convective complex of showers and some thunderstorms 
was moving southeast to our west and southwest this
morning and dissipating as it headed offshore.
The system brought heavy showers and thunderstorms to
portions of the Great Lakes Region yesterday.
 
Lowest May Sunshine, hours
1) 136.1 in 1888
2) 147.4 in 2005
3) 150.8 in 1927
4) 152.4 in 1983
5) 155.0 in 2003
6) 155.4 in 1948
7) 169.7 in 1917
8) 170.7 in 1892
 
Lowest May Sunshine, percent
1) 31 in 1888
2) 34 in 2005
3) 35 in 1927
   35 in 1983
   35 in 2003
6) 36 in 1948
7) 39 in 1892
   39 in 1917
 
Today's observations:
 
7 A.M.  
Weather: Scattered altocumulus, floccus and few castellanus,
generally decreasing past hour, overcast dense cirrostratus,
few thin spots in overcast overhead
Temperature: 70F, Dew point: 66F; Wind: SSW at 8 kts
Sea-level pressure: 30.03 inches Hg, rising
Visibility: 12 miles, hazy
6-hour min. temp: 66F
BHO SA 1155 95 SCT E250 OVC 12 168/70/66/2008/003/
FEW ACC ALQDS DSPTNG DNS CS THN SPTS IOVC OVHD HAZY/
8/087 51012 10070 20066
 
10 A.M.
Weather: Overcast dense cirrostratus, few altocumulus
and altocumulus lenticularis, sun dimly visible    
Temperature: 75F, Dew point: 69F; Wind: W at 11 kts,
Wind: Direction gradually veering
Wind: Direction variable SW-WNW
Sea-level pressure: 30.06 inches Hg, rising
Visibility: 12 miles, hazy
BHO SA 1455 E200 OVC 12 180/75/69/2611/006/
FEW AC/ACSL SUN DISC VSB WND GRDLY VEERING
WND 23V29 HAZY/ 8/047 51012
 
1 P.M.
Weather: Scattered dense cirrus, east thru south,
overcast cirrus, partly thin, break in overcast NW-N    
Temperature: 82F, Dew point: 68F; Wind: N at 6 kts,
Wind: Light
Sea-level pressure: 30.04 inches Hg, falling
Visibility: 12 miles, except 20 miles WNW, hazy 
6-hour max. temp: 83F
BHO SA 1755 200 SCT E250 BKN 250 OVC 12 173/82/68/3506/004/
FEW CU/MDT CU ALQDS DNS CI E-S OVC PTLY THN BINOVC NW-N 
VSBY WNW 20 HAZY ALQDS WND LGT/ 8/202 58007 10083 20070
 
WEATHER SUMMARY FOR SUNDAY, MAY 29
 
TEMPERATURE (DEGREES F)
MAX.....82     NORMAL.....71  
MIN.....64     NORMAL.....51
MEAN....73     NORMAL.....61
 
DEPARTURE FROM 30-YEAR NORMAL..................+12
TOTAL DEPARTURE FOR THE MONTH..................+19 [+0.5 DEGREES/DAY]
 
HEATING DEGREE DAYS    
TOTAL HEATING UNITS FOR YESTERDAY.............0    DEPARTURE........-5
TOTAL HEATING UNITS FOR THE MONTH...........258    DEPARTURE........-3
TOTAL HEATING UNITS FOR THE SEASON.........6153    DEPARTURE......-134
TOTAL HEATING UNITS LAST SEASON TO DATE....5641    DIFFERENCE.....+512
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..............32 S   AT  1:30 P.M.
                   AEROVANE...............35 S   AT  3:55 P.M.
                   ASOS...................31 S   AT  2:56 P.M.
                   DAVIS..................33 S   AT  2:56 P.M. 
THE FASTEST MILE FOR YESTERDAY............23 s   at  3:55 P.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE.............23 S   AT  3:56 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE............24 S   AT  2:36 P.M.  
AVERAGE WIND SPEED AND DIRECTION........14.3 S
                   ASOS.................14.1  
                   DAVIS................12.8 S [180 DEG]
 
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE........-0.12
                         ASOS..............0.00  
TOTAL PRECIPITATION FOR THE MONTH..........3.97  DEPARTURE........+0.44 
                         ASOS..............3.86
TOTAL PRECIPITATION FOR THE YEAR..........22.19  DEPARTURE........+0.71
                        ASOS..............22.82**
**ASOS data is in error due to system failure on 1/12-13   
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2011 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
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
5/1  55/43/49/-3/0.00/0.0/819/97    30 NE
5/2  73/42/58/+6/0.00/0.0/651/77    24 SSW
5/3  74/51/63/+10/0.00/0.0/441/52   31 SSE
5/4  63/44/54/+1/0.57/0.0/000/00    35 SSE
5/5  58/41/50/-3/0.02/0.0/264/31    47 W
5/6  70/43/57/+3/0.00/0.0/667/78    41 SSE  AERO 41 MPH SSE
5/7  71/48/60/+6/0.50/0/0/326/38    29 WNW  TSTM 
5/8  54/48/51/-3/0.00/0.0/238/27    31 NE
5/9  67/47/57/+2/T/0.0/474/55       43 N
5/10 53/46/50/-5/0.07/0.0/000/00    50 N
5/11 59/45/52/-3/0.14/0.0/035/04    37 NNE
5/12 57/48/53/-3/T/0.0/287/33       30 NNE
5/13 64/46/55/-1/0.00/0.0/828/95    22 NE
5/14 64/43/54/-3/T/0.0/035/04       22 SSE
5/15 63/47/55/-2/0.77/0.0/000/00    23 NE
5/16 47/45/46/-11/0.31/000/00       38 NNE
5/17 48/45/47/-10/0.32/000/00       36 NNE
5/18 53/48/51/-7/0.20/000/00        29 NNE
5/19 62/49/56/-2/0.62/035/04        27 NNE
5/20 67/49/58/0/0.01/230/26         18 NE 
5/21 69/44/57/-2/T/461/52           28 NE
5/22 54/44/49/-10/0/071/08          28 NNE
5/23 62/47/55/-4/0.12/000/00        40 SSE  AERO 45 MPH SSE
5/24 80/62/71/+11/0.31/232/26       43 S    AERO 46 MPH S
5/25 75/58/67/+7/0.00/777/87        23 SE 
5/26 80/54/67/+7/0.00/644/72        35 SSE  AERO 38 MPH SSE
5/27 89/62/76/+15/0.00/628/70       33 SSE  AERO 36 MPH SSE
5/28 80/63/72/+11/0.00/584/65       35 SE   AERO 38 MPH SE
5/29 82/64/73/+12/0.00/513/57       32 S    AERO 35 MPH S
 
5/30 our morning low temp: 66F; the normal low is now 51F
 
DAILY RECORDS FOR MAY 2011
None so far...
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 30
HIGH 93F IN 1929
LOW 39F IN 1949,1961
PRECIP 1.47 INS 1948
PEAK GUST 61e MPH NW IN 1945
 
RECORDS FOR MAY 31
HIGH 92F IN 1944,1987
LOW 35F IN 1961
PRECIP 5.02 INS 1984 (RECORD FOR MAY)
PEAK GUST 54e MPH WNW IN 1945
 
TODAY'S REPORT PREPARED BY: Robert Skilling