BLUE HILL METEOROLOGICAL OBSERVATORY 
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 22, 2011
ALL TIMES ARE IN EASTERN STANDARD TIME
 
DENSE FOG THIS MORNING...
 
After reaching an afternoon high of 69F yesterday (the highest
temperature since May 7th of this month), temperatures rapidly
dropped throughout the evening down to 44F with winds steadily rising out
of the north-northeast. This morning, dense fog obscured visibilities
less than 1/4 mile for the ninth consecutive day and the eleventh time
this month! 
 
As of 10:00 AM EDT, the fog has lifted and temperatures are well below normal
in the upper 40s.
 
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) 33 in 2011 (thru 18th)
3) 34 in 2005
4) 35 in 1927
   35 in 1983
   35 in 2003
7) 36 in 1948
8) 39 in 1892
   39 in 1917
 
 
Today's observations:
 
7 A.M.  
Weather: Sky obscured with dense fog
Temperature: 46F, Dew point: 46F; Wind: NNE at 8 kts
Wind: Direction variable NNW to ENE
Sea-level pressure: 30.21 inches Hg, rising
Visibility: 1/4 mile, visibility variable 1/4 to 3/4 mile
24-hour precip: Trace
6-hour min. temp: 44F
BHO SA 1155 W3 X 1/4VF 229/46/46/0208/021/ VSBY 1/4V3/4
WND 33V06/ 8//// 52020 10046 20044
 
                                                                       
WEATHER SUMMARY FOR SATURDAY, MAY 21
 
TEMPERATURE (DEGREES F)
MAX.....69     NORMAL.....69
MIN.....44     NORMAL.....49
MEAN....57     NORMAL.....59
 
DEPARTURE FROM 30-YEAR NORMAL...................-2
TOTAL DEPARTURE FOR THE MONTH..................-30 [-1.6 DEGREES/DAY]
 
HEATING DEGREE DAYS    
TOTAL HEATING UNITS FOR YESTERDAY.............8    DEPARTURE........+1
TOTAL HEATING UNITS FOR THE MONTH...........232    DEPARTURE.......+20
TOTAL HEATING UNITS FOR THE SEASON.........6127    DEPARTURE......-111
TOTAL HEATING UNITS LAST SEASON TO DATE....5634    DIFFERENCE.....+493
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..............28 NE  AT  7:30 P.M.
                   AEROVANE...............30 NE  AT  7:30 P.M.
                   ASOS...................26 NE  AT  7:30 P.M.
                   DAVIS..................27 NNE AT  7:29 P.M.
THE FASTEST MILE FOR YESTERDAY............18 NE  AT  8:19 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE.............18 NE  AT  7:31 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE............18 NE  AT  7:31 P.M.  
AVERAGE WIND SPEED AND DIRECTION..........7.4 NNE
                   ASOS...................6.8    
                   DAVIS..................6.5 NNE [023 DEG]
* Last of several occurrences
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace  DEPARTURE........-0.12
                         ASOS..............0.01  
TOTAL PRECIPITATION FOR THE MONTH..........3.54  DEPARTURE........+0.97 
                         ASOS..............3.40
TOTAL PRECIPITATION FOR THE YEAR..........21.76  DEPARTURE........+1.24
                        ASOS..............22.36**
**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/-5/0.06/0.0/000/00    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/.../000/00        38 NNE
5/17 48/45/47/-10/.../000/000       36 NNE
5/18 53/48/51/-7/.../000/00         29 NNE
5/19 62/49/56/-2/.../.../..         27 NNE
5/20 67/49/58/0/.../.../..          18 NE 
5/21 69/44/57/-2/T/.../..           28 NE
 
5/22 morning low temp: 44F; the normal low is now 49F
 
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 22
HIGH 93F IN 1911
LOW 35F IN 1907
PRECIP 3.75 INCHES IN 1920
PEAK GUST 49e MPH SSW IN 1947
 
RECORDS FOR MAY 23
HIGH 92F IN 1964,1992
LOW 38F IN 1976
PRECIP 0.97 INS IN 1979
PEAK GUST 49e MPH W IN 1945
 
TODAY'S REPORT PREPARED BY: Eli Melaas