BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, APRIL 16, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME 
 
A FROSTY START TO THE DAY IN SURROUNDING AREA
VERY SUNNY AGAIN TODAY FOR 4TH CONSECUTIVE DAY
NORTHEAST WINDS BRING CONTINUING COOL TEMPS.
 
Low temperatures dipped to the mid-20's at
Norwood and Taunton airports early this morning
with a heavy frost after a temperature inversion
developed overnight.
Sunshine prevailed again today but the
prevailing northeast winds continued to keep
temperatures cool and about where they were
during the early afternoon yesterday,
in the upper 40's.
 
Today's weather observations: 
 
7 A.M.
Weather: Clear, few cirrus W-N 
Temperature: 41F, Dew point: 23F, Wind: N at 12G20 kts,
Wind: Direction variability NNW to NE
Sea-level pressure: 30.29 inches Hg, rising
Visibility: 60 miles, 70 miles northwest, light haze
6-hour minimum temperature: 34F
BHO SA 1155 CLR 60 258/41/23/0112G20/029/ FEW CI W-N
LGT HZ VSBY NW 70 WND 33V04/ 8/001 53021 10041 20034 
 
10 A.M.
Weather: High thin broken cirrus clouds, small cumulus
forming distant ESE-SSE 
Temperature: 48F, Dew point: 27F, Wind: NNE at 11G22 kts,
Wind: Direction variability NNW to E,
Wind: gust to 25 kts past hour 
Sea-level pressure: 30.34 inches Hg, rising
Visibility: 60 miles, 70 miles northwest, light haze  
BHO SA 1455 300 –BKN 60 273/48/27/0211G22/034/
SML CU FRMG DSNT ESE-SSE LWR CI W-N VSBY NW 70
LGT HZ WND 34V08/ 8/101 51015
 
1 P.M. 
Weather: Thin scattered cirrus, clear sky overhead thru
northwest thru northeast, few small cumulus distant E-SE  
Temperature: 48F, Dew point: 26F, Wind: ENE at 11 kts,
Wind: Direction variability NNE-ESE,
Wind: gust to 21 kts past hour
Sea-level pressure: 30.32 inches Hg, falling
Visibility: 60 miles, 70 NW, light haze 
6-hourly max. temp: 49F
BHO SA 1755 250 –SCT 300 –SCT 60 268/48/26/0711/032/ FEW SML CU
DSNT E-SE CLR SKY OVHD-NW-NE VSBY NW 70 LGT HZ WND 03V11
GUST 21 KTS PST HR/ 8/101 58005 10049 20041
 
WEATHER SUMMARY FOR WEDNESDAY, APRIL 15, 2009
 
TEMPERATURE (DEGREES F)
MAX.....49    NORMAL......55
MIN.....36    NORMAL......37
MEAN....43    NORMAL......46
 
DEPARTURE FROM 30-YEAR NORMAL..................-3
TOTAL DEPARTURE FOR THE MONTH..................+9  [+0.4 DEGREE/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............22  DEPARTURE........+3
TOTAL HEATING UNITS FOR THE MONTH............311  DEPARTURE........-9
TOTAL HEATING UNITS FOR THE SEASON..........5729  DEPARTURE.......-55
TOTAL HEATING UNITS LAST SEASON TO DATE.....5445  DIFFERENCE.....+284
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............35 NE  AT  2:03 P.M. *
                   AEROVANE.............31 NE  AT 12:06 P.M. *
                   ASOS.................35 NE  AT 12:06 P.M.
                   DAVIS................33 NE  AT 12:05 P.M.
FASTEST MILE FOR YESTERDAY..............26 NE  AT 12:06 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...........24 NE  AT 12:07 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..........26 NE  AT 12:06 P.M.
                   AVERAGE............13.1 NE
                   ASOS...............12.8
                   DAVIS..............12.6 NE [040 deg]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.00 DEPARTURE.........-0.15 
                         ASOS...............0.00
TOTAL PRECIPITATION FOR THE MONTH...........3.23 DEPARTURE.........+0.98
                         ASOS...............3.28
TOTAL PRECIPITATION FOR THE YEAR...........13.31 DEPARTURE.........-2.57
                         ASOS..............14.41 #
# 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................0.2   DEPARTURE.........-1.4
TOTAL SNOWFALL FOR THE SEASON..............78.9   DEPARTURE........+20.4
 
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/+3/0.01/0/015/02       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    AER0 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/.../..          35 NE    AERO 31 MPH NE
 
4/16 morning low temp: 34F; our normal low is now 37F
 
 
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 16
HIGH 87 IN 1896
LOW 23 IN 1943
PRECIP 2.45 IN. IN 1929
SNOWFALL 2.0 IN. IN 1904, 1962
PEAK GUST 73 MPH E IN 2007
 
RECORDS FOR APRIL 17
HIGH 93 IN 2002
LOW 21 IN 1908
PRECIP 1.68 IN 1954
SNOWFALL 1.0 IN. IN 1899
PEAK GUST 58 MPH NW IN 1994
 
TODAY'S REPORT PREPARED BY: Robert Skilling