BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 4, 2009 
ALL TIMES ARE IN EASTERN STANDARD TIME
 
SCANT 0.05 RAINFALL FOR THREE DAYS WITH RAIN
DENSE HIGH CLOUDS AND NO SUNSHINE TODAY
 
Despite rain on each of the first three days
of the new month we've come up with only 0.05
inch to date.  Both yesterday and Friday had
traces in mostly very light rain showers.
A deck of dense middle and high clouds have
obscured all but 6 minutes of any bright
sunshine for today.
 
Today's observations:
 
7 A.M.  
Weather: Overcast altostratus with few altocumulus,
virga, bright spots in overcast and sun occasionally
dimly visible
Temperature: 52F, Dew point: 49F, Wind: SW at 6 kts 
Sea-level pressure: 30.08 inches Hg, rising
Visibility: 15 miles, thin fog
6-hour minimum temp: 48F
24-hour precipitation: trace
BHO SA 1155 E140 OVC 15 187/52/49/2206/008/
FEW AC BRGHT STPS IOVC SUN OCNL DMLY VSB VIRGA THN FG/
8/07/ 53015 10052 20048
 
10 A.M.  
Weather: Scattered altostratus, overcast of dense cirrostratus,
sun dimly visible
Temperature: 58F, Dew point: 48F, Wind: S at 6 kts
Sea-level pressure: 30.10 inches Hg, rising
Visibility: 25 miles, hazy
BHO SA 1455 140 SCT E180 OVC 25 193/58/48/1806/010/
SUN DMLY VSB HAZY/ 8/17/ 51006
 
1 P.M.  
Weather: Overcast with altocumulus and altostratus, bright spots
in overcast
Temperature: 64F, Dew point: 44F, Wind: SSE at 4 kts
Sea-level pressure: 30.10 inches Hg, steady
Visibility: 40 miles, WNW 50 miles, NE 25 miles, light haze
6-hour maximum temp: 64F 
BHO SA 1755 E140 OVC 40 192/64/44/1504/010/ BRGHT SPTS IOVC
VSBY WNW 50 NE 25 LGT HZ ALQDS WND LGT/ 8/07/ 55001 10064 20052 
 
WEATHER SUMMARY FOR SUNDAY, MAY 3
 
TEMPERATURE (DEGREES F)
MAX.....64    NORMAL.....62
MIN.....48    NORMAL.....43
MEAN....56    NORMAL.....53
 
DEPARTURE FROM 30-YEAR NORMAL...........+3
TOTAL DEPARTURE FOR THE MONTH..........+18 [+5.8 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............9  DEPARTURE.......-4
TOTAL HEATING UNITS FOR THE MONTH............20  DEPARTURE......-19
TOTAL HEATING UNITS FOR THE SEASON.........5916  DEPARTURE.....-149
TOTAL HEATING UNITS LAST SEASON TO DATE....5671  DIFFERENCE....+245
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............25 S   AT 4:01 P.M.
                   AEROVANE.............23 S   AT 4:01 P.M. 
                   ASOS.................23 S   AT 4:08 P.M. 
                   DAVIS................22 S   AT 4:01 P.M.
FASTEST MILE FOR YESTERDAY..............19 S   AT 4:00 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...........18 SSE AT 4:02 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE..........17 SSE AT 4:01 P.M.
AVERAGE WIND SPEED AND DIRECTION.......8.9 S
                   ASOS................8.9
                   DAVIS...............8.5 SSW [200 DEG]
 
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..........0.05  DEPARTURE....-0.34
                         ASOS..............0.05 
TOTAL PRECIPITATION FOR THE YEAR..........14.66  DEPARTURE....-3.68
                         ASOS.............15.73  
 
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..............78.9  DEPARTURE.....18.8
 
PRELIMINARY CLIMATE SUMMARY FOR APRIL 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
4/1  45/31/38/-3/0.13/0/015/02       24 SE    
4/2  52/39/46/+4/0.02/0/000/00       20 SSE       
4/3  58/45/52/+10/0.70//000/00       39 SSE   AERO 38 MPH SSE TSTM
4/4  51/38/45/+3/0.01/0/015/02       48 WSW   AERO 48 MPH WSW 
4/5  58/37/48/+5/0/0/551/71          40 W     AERO 37 MPH W
4/6  55/38/47/+4/1.42/0/047/006      42 SE    AERO 40 MPH SE  TSTM 
4/7  50/34/42/-1/T/0/109/14          36 WSW   AERO 35 MPH WSW
4/8  45/32/39/-5/0/0/149/19          33 SW    AERO 31 MPH SW
4/9  60/34/47/+3/0/0/692/88          36 SSW   AERO 33 MPH SSW
4/10 65/41/53/+9/0.18/0/544/69       37 SSW   AERO 35 MPH SSW 
4/11 44/33/39/-6/0.77/0.2/000/00     35 N     AERO 30 MPH N
4/12 43/29/36/-9/0/0/541/68          45 NW    AERO 43 MPH WNW
4/13 52/29/41/-4/0/0/734/92          38 W     AERO 35 MPH W
4/14 58/37/48/+2/0/0/696/87          25 E     
4/15 49/36/43/-3/0/0/650/81          35 NE    AERO 31 MPH NE
4/16 50/34/42/-4/0/0/806/100         29 NNE  
4/17 69/35/52/+5/0/0/695/86          37 W     AERO 33 MPH W
4/18 64/44/54/+7/0.05/0/170/21       28 W  
4/19 52/38/45/-2/0.03/0/773/95       33 NNE   AERO 28 MPH NNE
4/20 51/36/44/-4/0.10/0/196/24       43 E     AERO 39 MPH E
4/21 58/42/50/+2/0.95/0/000/00       43 E     AERO 43 MPH S
4/22 62/45/54/+5/0.16/0/296/36       28 S    
4/23 56/40/48/-1/0.01/0/668/81       43 W
4/24 70/40/55/+6/0/0/810/98          30 W
4/25 83/49/66/+16/T/0/647/78         29 S
4/26 88/56/72/+22/0/0/574/69         33 NE
4/27 72/49/61/+11/0/0/768/92         29 S
4/28 92/57/75/+24/0/0/704/84         37 SSW   AERO 36 MPH S
4/29 63/44/54/+3/T/0/823/98          35 NW    AERO 30 MPH NW TSTM
4/30 67/41/54/+2/T/0/717/85          37 S
 
NEW DAILY RECORDS FOR APRIL 2009...
New record high maximum temperature for April 25 of 83F
surpasses 80F in 1942.
New record high maximum temperature for April 26 of 88F
surpasses 83F in 1908.
New record high minimum temperature for April 26 of 56F
surpasses 55F in 1985.
Maximum temperature of 92F for April 28 equals record
high maximum of 92F in 1990.
Minimum temperature of 57F for April 28 equals record
high minimum of 57F in 1935. 
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
5/1 64/53/59/+7/T/.../..          37 SSW   AERO 37 MPH SSW
5/2 68/52/60/+8/0.05/.../..       32 WNW
5/3 64/48/56/+3/T/.../..          25 S
 
5/4 morning low temp: 48F; our normal low is now 43F
 
 
NEW DAILY RECORDS FOR MAY 2009...
NONE
 
DAILY EXTREMES
 
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 4
HIGH 90F IN 2001
LOW 27F IN 1911 (RECORD FOR MAY)
PRECIP 1.92 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966
 
RECORDS FOR MAY 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976
 
TODAY'S REPORT PREPARED BY: Robert Skilling