BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, APRIL 7, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME 
 
HEAVY RAINFALL YESTERDAY TOTAL 1.42 INCHES
MOST OF RAIN FELL IN JUST 4 HOURS
SPRINKLES OF RAIN TODAY WITH JUST A TRACE
 
The heavy rain which began by mid-afternoon
yesterday amounted to close to 0.80 inch in
just two hours between 2 and 4 P.M. EDT.  
Nearly an inch and a quarter fell between 2 
and 6 P.M. EDT.  Temperatures rose from the 
low 40's in the early afternoon to 55F with 
the arrival of the warm front during the early
evening.  Mostly cloudy weather has produced
a few light showers leaving only a trace.
 
Today's Observations:
 
7 A.M.
Weather: Partial obscurement with fog  
Temperature: 43F, Dew point: 43F, Wind: S at 12 kts
Sea-level pressure: 29.19 inches Hg, rising
Visibility: 1 mile, variable 3/4 to 1 1/2 miles
6-hour minimum temperature: 41F
24-hour precipitation: 1.42 inches
BHO SA 1155 –X E3 OVC 1VF 884/43/43/1912/919/
F2 STRA DRFTG OVR SMT VSBY 3/4V11/2
INCRSNG CIG/VSBY PST HR/ 8/6//
53004 ASOS 70145 MANUAL 70142 10043 20041 
 
10 A.M.
Weather: Scattered cumulus and moderate cumulus,
overcast variable to broken stratocumulus, breaks
in the overcast 
Temperature: 48F, Dew point: 40F, Wind: SSW at 17G27 kts,
Wind: Peak wind gust from SSW at 27 kts at 9:53 A.M.
Sea-level pressure: 29.20 inches Hg, rising
Visibility: 35 miles
3-hourly precip: trace    
BHO SA 1455 30 SCT E40 OVC 35 888/48/40/2017G27/920/ MDT CU ALQDS
BINOVC OVC V BKN PK WND 2027/53/ 8/8// 53004 MANUAL 6000/
 
1 P.M. 
Weather: Scattered cumulus and moderate cumulus,
broken stratocumulus, rain shower 25 miles west,
few patches of virga, very light shower began
and 12:35 P.M. and ended 12:45 P.M. 
Temperature: 45F, Dew point: 34F, Wind: WSW at 17G26 kts,
Wind: Peak wind gust 31 kts SW @ 12:34 P.M.,
Wind: Direction variable SW to W     
Sea-level pressure: 29.26 inches Hg, rising
Visibility: 75 miles, except 30 miles in rain shower west
6-hourly precip: trace
6-hourly max. temp. 50F 
BHO SA 1755 30 SCT E40 BKN 75 908/45/34/2417G26/926/
MDT CU RW25 W FEW PTCHS VIRGA VSBY W 30/RW PK WND 2331/34/
WND 22V27 RB35E45/ 8/800 51020 MANUAL 6000/ 10050 20043 
 
WEATHER SUMMARY FOR MONDAY APRIL 6, 2009
 
TEMPERATURE (DEGREES F)
MAX.....55    NORMAL.....52
MIN.....38    NORMAL.....34
MEAN....47    NORMAL.....43
 
DEPARTURE FROM 30-YEAR NORMAL................. +4
TOTAL DEPARTURE FOR THE MONTH.................+23  [+3.6 DEGREE/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............18  DEPARTURE.........-4
TOTAL HEATING UNITS FOR THE MONTH............114  DEPARTURE........-23
TOTAL HEATING UNITS FOR THE SEASON..........5532  DEPARTURE........-69
TOTAL HEATING UNITS LAST SEASON TO DATE.....5272  DIFFERENCE......+260
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............42 SE  AT 5:34 P.M.                   
                   AEROVANE.............40 SE  AT 5:34 P.M. 
                   ASOS.................37 SE  AT 5:34 P.M.   
                   DAVIS................39 SSE AT 5:34 P.M. 
FASTEST MILE FOR YESTERDAY..............29 E   AT 2:35 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...........26 E   AT 3:03 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE..........29 E   AT 2:35 P.M. 
                   AVERAGE............13.2 E               
                   ASOS...............12.8 
                   DAVIS..............12.9 E [090 deg]
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....1.42 DEPARTURE.........+1.27
                         ASOS...............1.45
TOTAL PRECIPITATION FOR THE MONTH...........2.28 DEPARTURE.........+1.38
                         ASOS...............2.36
TOTAL PRECIPITATION FOR THE YEAR...........12.36 DEPARTURE.........-2.17
                         ASOS..............13.49 #
# Includes erroneous ASOS precipitation data on 1/1/09, 1/2/09 and 2/27/09.
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0   DEPARTURE.........-0.1
TOTAL SNOWFALL FOR THE MONTH................0.0   DEPARTURE.........-0.7
TOTAL SNOWFALL FOR THE SEASON..............78.7   DEPARTURE........+21.1
 
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  43/31/38/-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/.../..       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    AER0 40 MPH SE  TSTM 
 
4/7  morning low temp: 41F; our normal low temp. now 34F
 
NEW DAILY RECORDS FOR APRIL 2009...
None to date..
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR APRIL 7
HIGH 86 IN 1929
LOW 13 IN 1982
PRECIP 1.72 IN. IN 1924
SNOWFALL 4.5 IN. IN 1967, 1996
PEAK GUST 65 MPH WNW IN 1982
 
RECORDS FOR APRIL 8
HIGH 87 IN 1991
LOW 17 IN 1888
PRECIP 1.78 IN. IN 1956
SNOWFALL 9.3 IN. IN 1956
PEAK GUST 70 MPH S IN 2000
 
TODAY'S REPORT PREPARED BY: Robert Skilling