BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, MAY 16, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
VERY COOL NORTHEAST WIND DROPS TEMPERATURES INTO THE 50'S
SHOWERS AND A THUNDERSTORM LAST NIGHT BUT ONLY 0.01 IN OF RAIN
 
A frontal passage from the northeast sent the temperature 
down from an early morning high of 66 just before 9 a.m. EDT
to the upper 50's early this afternoon. A fog bank and stratus
layer could be seen to our northeast through southeast.   
Last evening's showers included a rumble of thunder but left 
only 0.01 of an inch of rainfall. 
 
Today's observations:
 
7 A.M.   
Weather: Clear and hazy  
Temperature: 61F, Dew point: 56F, Wind: S at 04 kts  
Sea-level pressure: 29.74 inches Hg, steady
Visibility: 7 miles with thin fog and haze 
6-hourly min. temp. 55F
24-houry rainfall: 0.01 in.  
BHO SA 1155 CLR 7 071/61/55/1704/974/ THN FH VSBY INCRSNG/
55001 MANUAL 70001 ASOS 70001 10061 20055 
   
10 A.M.
Weather: High thin broken cirrus clouds   
Temperature: 65F, Dew point: 53 Wind: E at 08 kts 
Sea-level pressure: 29.71 inches Hg, falling   
Visibility: 6 miles in haze     
BHO SA 1455 220 SCT 250 -BKN 6H 060/65/53/0808/971/ 8/001 58011
  
1 P.M.
Weather: Scattered cumulus and altocumulus, few modt. cumulus 
Temperature: 58F, Dew point: 51F, Wind: NE at 17 kts 
Sea-level pressure: 29.67 inches Hg, falling   
Visibility: 6 miles in haze, stratus and fog NE-SE     
Six hourly max. temp: 66 deg.
BHO SA 1755 60 SCT 150 SCT 5H 049/58/51/0417/967/ FEW MDT CU 
STRA/FG LAYR NE-SE WND 01V08/ 8/240 58011 10066 20057
 
WEATHER SUMMARY FOR TUESDAY, MAY 15 
 
TEMPERATURE (DEGREES F)
MAX.....80    NORMAL.....67 
MIN.....50    NORMAL.....47
MEAN....65    NORMAL.....57
DEPARTURE FROM 30-YEAR NORMAL...........+8
TOTAL DEPARTURE FOR THE MONTH..........+65 (+4.1 DEGREES/DAY)
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY........... 0  DEPARTURE........- 9
TOTAL HEATING UNITS FOR THE MONTH..........109  DEPARTURE........-56 [corrected] 
TOTAL HEATING UNITS FOR THE SEASON........5725  DEPARTURE.......-466
TOTAL HEATING UNITS LAST SEASON TO DATE...5622  DIFFERENCE......+103
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............30 S    AT  11:34 A.M. *  
                   AEROVANE.............29 S    AT  11:21 A.M. * 
                   ASOS.................30 S    AT  11:21 A.M.  
                   DAVIS................37 S    AT  10:15 A.M. 
FASTEST MILE FOR YESTERDAY..............23 S    AT  11:34 A.M. *  
MAXIMUM 2-MINUTE ASOS AVERAGE...........24 S    AT  11:35 A.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE..........26 S    AT  11:34 A.M.  
AVERAGE WIND SPEED AND DIRECTION.......16.8 S   
ASOS FOR THE DAY.......................16.7                    
DAVIS FOR THE DAY .....................17.1 SSW [190 degrees]
 
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.01  DEPARTURE.....-0.11
                         ASOS..............0.01  
TOTAL PRECIPITATION FOR THE MONTH..........0.11   DEPARTURE....-1.74 
                         ASOS..............0.09    
TOTAL PRECIPITATION FOR THE YEAR..........20.53   DEPARTURE....+0.73
                         ASOS.............20.06    
 
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..............27.6  DEPARTURE.....-32.5  
    
PRELIMINARY CLIMATE SUMMARY FOR MAY 2007......CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
 
AERO: Aerovane recording wind system when significant
TSTM: Thunderstorm day
....: Data not yet available
 
5/1  67/44/56/+4/0/0/624/74      33 NW 
5/2  64/45/55/+3/0.06/0/381/45   36 NW    Aero 33 MPH WNW
5/3  67/42/55/+2/0/0/849/100     38 W     Aero 37 MPH W
5/4  66/44/55/+2/0/0/842/99      39 WNW   Aero 40 MPH WNW 
5/5  65/45/55/+2/0/0/384/45      33 N  
5/6  51/42/47/-7/T/0/514/60      36 N     Aero 33 MPH N 
5/7  68/39/54/0/0/0/798/93       25 S
5/8  77/43/60/+6/0/0/851/99      33 S     Aero 31 MPH S 
5/9  85/54/70/+15/0/0/707/92     30 S 
5/10 85/60/73/+18/0/0/692/80     29 S     Aero 27 MPH S
5/11 74/60/67/+12/0.02/0/355/41  23 S
5/12 63/47/55/-1/0.02/0/.../..   32 NE    
5/13 65/46/56/0/T/0/775/89       33 WNW   Aero 33 MPH WNW 
5/14 73/43/58/+1/0/0/822/94      30 SSW
5/15 80/50/65/+8/0.01/0/.../..   30 S     TSTM evening  
 
5/16 morning low temp. 55 deg; normal now 47 deg. 
 
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
PRE 2.07 INS IN 1916
PEAK GUST 52 MPH SW IN 1967, W IN 1974
 
TODAY'S REPORT PREPARED By: Robert Skilling/Stephanie Radner