BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
  
DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 16, 2008  
ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED
 
HIGH CLOUDS THICKENING BUT NO RAIN THROUGH 2 P.M. 
SUN WAS SEEN DIMLY THROUGH THE CLOUDS THIS MORNING
 
As of early this afternoon we could see the precipitation
aloft (virga) and off to the south and southwest but nothing
was reaching the ground here.  The air continued quite dry and 
precipitation was evaporating before reaching the ground. 
However, visibility was decreasing to the southwest and 
rain finally began falling here at 2:20 P.M. EDT. 
 
Temperatures reached a high of 59 degrees during a very brief
glimpse of the sun this morning but had fallen back to the
mid-50's with a very light east wind and heavy cloud cover.
 
Today's observations:
 
8 A.M. EDT
Weather: Overcast of middle and high clouds, 
Scattered altocumulus, broken altostratus, overcast cirrostratus,
few stratocumulus, sun visible through altostratus and cirrostratus layers    
Temperature: 54F, Dew point: 44F,  Wind: NNE at 10 kts,
Wind: gradually veering
Sea-level pressure: 29.86 inches Hg, steady
Visibility: 40 miles, NE-SE 30, W-NW 50 
6-hour min temp: 50F
BHO SA 1155 70 SCT E150 BKN 200 OVC 40 113/54/44/0210/986/ 
FEW SC SUN VSBL VSBY NE-SE 30 W-NW 50 WND GRDLY VEERING/ 
8/577 55003 10054 20050 
 
11 A.M. EDT
Weather: High dense overcast cirrostratus, few cumulus SW-W and
few altocumulus 
Temperature: 57F, Dew point: 45F,  Wind: ENE at 9 kts
Wind: direction variable N to E
Sea-level pressure: 29.84 inches Hg, falling
Visibility: 35 miles, 45 miles WNW, light haze   
BHO SA 1455 E200 OVC 35 105/57/45/0609/984/ FEW SML CU SW-W 
FEW AC DENS CS OVC SUN DMLY VSB VSBY WNW 45 LGT HZ 
WND 01V09/ 8/147 58008 
 
2 P.M. EDT
Weather: Overcast nimbostratus, virga, precipitation within sight
SE-SW 
Temperature: 54F, Dew point: 42F,  Wind: E at 6 kts 
Sea-level pressure: 29.78 inches Hg, falling
Visibility: 45 miles, SE thru SW 20 miles  
6-hour max temp: 59F
BHO SA 1755 E130 OVC 45 084/54/42/0906/978/ VIRGA ALQDS 
FEW SC SSE-SW CIG LWR SE-SW HIER NW-E PCPN/VSBY 20 SE-SW/ 
8/52/ 58021 10059 20054 
 
WEATHER SUMMARY FOR THURSDAY, MAY 15
 
TEMPERATURE (DEGREES F)
MAX.....67    NORMAL.....67
MIN.....47    NORMAL.....46
MEAN....57    NORMAL.....57
 
DEPARTURE FROM 30-YEAR NORMAL............ 0  
TOTAL DEPARTURE FOR THE MONTH...........-31 [-2.3 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............8  DEPARTURE........-1
TOTAL HEATING UNITS FOR THE MONTH...........190  DEPARTURE.......+25 
TOTAL HEATING UNITS FOR THE SEASON.........5801  DEPARTURE......-390 
TOTAL HEATING UNITS LAST SEASON TO DATE....5725  DIFFERENCE......+76
 
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............22 S    AT  5:55 A.M. 
                   AEROVANE.............21 S    AT  5:55 A.M.    
                   ASOS.................21 S    AT  9:37 A.M.     
                   DAVIS................24 SSW  AT  5:54 A.M.     
FASTEST MILE FOR YESTERDAY..............17 s    at  6:00 A.M. *   
MAXIMUM 2-MINUTE ASOS AVERAGE...........17 S    AT  10:40 A.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE..........19 S    AT  5:55  A.M.   
                   AVERAGE.............9.4 S   
                   ASOS................9.5    
                   DAVIS...............9.6 SSW [210 deg]    
* last of several occurrences....
  
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....trace  DEPARTURE......-0.12  
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.67   DEPARTURE......-1.18
                         ASOS..............0.62
TOTAL PRECIPITATION FOR THE YEAR..........21.43   DEPARTURE......+1.63
                         ASOS.............23.85 #
# Includes erroneous ASOS precipitation data on 2/13/08.
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2008 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system when significant
TSTM: Thunderstorm day
....: Data not yet available, records not finalized
 
5/1  60/35/48/-4/0/786/93        30 W    Aero 28 MPH W
5/2  48/42/45/-7/0.07/000/00     21 ENE
5/3  43/41/42/-11/0.09/000/00    25 E    
5/4  50/42/46/-7/0.17/000/00     27 E
5/5  69/40/55/+2/0/752/88        24 ESE  
5/6  74/46/60/+6/0/686/80        25 W
5/7  75/48/62/+8/0/722/84        29 S
5/8  75/54/65/+11/0.08/172/20    42 W    Aero 42 MPH W 
5/9  56/43/50/-5/0.26/000/00     30 NE
5/10 57/44/51/-4/T/407/47        35 NNE  
5/11 58/41/50/-5/0/747/86        24 ENE  
5/12 47/42/45/-11/0/017/02       43 NNE  Aero 43 MPH NNE
5/13 63/43/53/-3/0/812/93        47 NNE  Aero 50 MPH NNE
5/14 64/47/56/-1/0/788/90        23 ENE
5/15 67/47/57/0/T/009/01         22 S 
 
5/16 morning low temp. 50F; our normal low is now 47F
 
NEW DAILY RECORDS FOR MAY 2008
None to date.
 
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