BLUE HILL METEOROLOGICAL OBSERVATORY 
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 2, 2011
ALL TIMES ARE IN EASTERN STANDARD TIME
 
MONTH OF APRIL 2011 STATS
 
TEMPERATURE DEG. F
Av. Max. 56.6
Av. Min. 39.9
Mean     48.3 [+2.0]
24-hour corr. mean: 47.6
Highest temp: 78 on 27th
Lowest temp:  31 on 1st, 6th, 15th, 16th
Total heating units: 497 [-65]
Total seasonal heating units: 5895 [-131] 
Total precip:   4.61 ins. [+0.29] 
Total snowfall:  1.6 ins. [-1.5 ]
Greatest snowfall in 24 hours 4.6 ins. (31st-1st)
Sunshine: N/A until 5/4 or 5/5
Prevailing wind:    "      "
 
Today's observations:
 
7 A.M.  
Weather: Clear, cirrus S-W-N
Temperature: 48F, Dew point: 36F; Wind: WSW at 7 kts
Sea-level pressure: 30.32 inches Hg, rising
Visibility: 60 miles, distant haze  
6-hour min. temp: 42F  
BHO SA 1155 CLR 60 267/48/36/2507/032/ CI S-W-N  
DSNT HZ/ 8/001 53012 10048 20042
 
10 A.M.  
Weather: Thin scattered cirrus 
Temperature: 60F, Dew point: 37F; Wind: S at 5 kts
Wind: Light and variable
Sea-level pressure: 30.28 inches Hg, falling 
Visibility: 60 miles, distant haze 
BHO SA 1455 300 –SCT 60 255/60/37/1805/028/ FEW LWR CI
DSNT HZ WND LGT/ 8/001 58012
 
1 P.M.  
Weather: Clear, altocumulus layer including numerous
lenticular advancing and extending from SSW-NW,
few cirrus 
Temperature: 69F, Dew point: 41F; Wind: SW at 7 kts,
Wind: Direction variable SSE-WNW
Sea-level pressure: 30.21 inches Hg, falling
Visibility: 50 miles, distant haze increasing
Max. temp: 70F
BHO SA 1755 CLR 50 232/69/41/2307/021/ AC LYR SSW-NW
ADVCNG NMRS ACSL SW-NW FEW CI ALQDS INCR DSNT HZ WND 16V29/
8/051 58023 10070 20048
 
WEATHER SUMMARY FOR SUNDAY, MAY 1
 
TEMPERATURE (DEGREES F)
MAX.....55     NORMAL.....62
MIN.....43     NORMAL.....42
MEAN....49     NORMAL.....52
 
DEPARTURE FROM 30-YEAR NORMAL...................-3
TOTAL DEPARTURE FOR THE MONTH...................-3 
 
HEATING DEGREE DAYS    
TOTAL HEATING UNITS FOR YESTERDAY............16    DEPARTURE........+3
TOTAL HEATING UNITS FOR THE MONTH............16    DEPARTURE........+3
TOTAL HEATING UNITS FOR THE SEASON.........5911    DEPARTURE......-128
TOTAL HEATING UNITS LAST SEASON TO DATE....5482    DIFFERENCE.....+429
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..............30 NE  AT 11:37 A.M. *
                   AEROVANE...............29 NE  AT 11:37 A.M. * 
                   ASOS...................29 ENE AT 11:52 A.M.
                   DAVIS..................28 NE  AT 11:36 A.M. 
THE FASTEST MILE FOR YESTERDAY............20 NE  AT  1:03 P.M. * 
MAXIMUM 2-MINUTE ASOS AVERAGE.............21 ENE AT  1:04 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE............22 NE  AT 10:49 A.M. 
AVERAGE WIND SPEED AND DIRECTION.........10.9 NE
                   ASOS..................11.0  
                   DAVIS.................10.3 NE [040 DEG]
* last of several occurrences......
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE........-0.13
                         ASOS..............0.00  
TOTAL PRECIPITATION FOR MAY................0.00  
TOTAL PRECIPITATION FOR APRIL..............4.61  DEPARTURE........+0.29
                           ASOS............4.57
TOTAL PRECIPITATION FOR THE YEAR..........18.22  DEPARTURE........+0.14
                        ASOS..............18.96**
**ASOS data is in error due to system failure on 1/12-13   
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........-0.1
TOTAL SNOWFALL FOR THE APRIL................1.6  DEPARTURE........-1.5
TOTAL SNOWFALL FOR THE SEASON..............96.8  DEPARTURE.......+36.7
 
PRELIMINARY CLIMATE SUMMARY FOR APRIL 2011 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
4/1  36/31/34/-7/0.71/1.6/000/00     35 N    AERO 40 MPH N
4/2  50/33/42/0/T/0.0/581/76         38 W    AERO 41 MPH W
4/3  53/35/44/+2/0.00/0.0/753/98     41 W    AERO 42 MPH W
4/4  46/38/42/0/0.43/T/000/00        33 SE   AERO 36 MPH SE
4/5  61/35/48/+5/0.16/0.0/023/03     52 S    AERO 55 MPH S
4/6  51/31/41/-2/0.00/0.0/490/63     43 WSW  AERO 43 MPH WSW
4/7  52/32/42/-1/0.00/0.0/749/96     22 SSE 
4/8  52/34/43/-1/0.00/0.0/422/54     25 SSE
4/9  60/33/47/+3/0.00/0.0/699/89     30 SE
4/10 63/37/50/+6/0.03/0.0/496/63     31 SSE
4/11 69/47/58/+13/0.02/0.0/308/39    35 S    AERO 36 MPH S
4/12 61/43/52/+7/0.15/0.0/024/03     43 WNW  AERO 45 MPH WNW
4/13 47/40/44/-1/1.13/0.0/000/00     39 ENE  AERO 39 MPH ENE
4/14 63/39/51/+5/T/0.0/607/76        29 NNW
4/15 47/31/39/-7/0.00/0.0/730/91     28 NW
4/16 46/31/39/-7/0.18/0.0/266/33     45 ESE  AERO 46 MPH ESE 
4/17 61/46/54/+7/1.12/0.0/347/43     63 ESE  AERO 63 MPH ESE
4/18 59/40/50/+3/T/0.0/486/60        39 SW   AERO 38 MPH WSW
4/19 49/38/44/-3/0.09/0.0/000/00     20 NW
4/20 44/38/41/-7/T/0.0/000/00        31 NE   AERO 32 MPH NE
4/21 54/35/45/-3/0.00/0.0/703/86     60 W    AERO 62 MPH W
4/22 52/33/43/-6/0.00/0.0/517/63     21 WNW
4/23 52/36/44/-5/0.43/0.0/000/00     42 SSE  AERO 42 MPH SSE
4/24 74/51/63/+14/0.04/0.0/297/36    39 WSW  AERO 41 MPH W
4/25 56/45/51/+1/.../0.0/.../..      17 NE
4/26 64/45/55/+5/T/0.0/.../..        24 NNE 
4/27 78/58/68/+18/0.01/0.0/000/00    36 S    AERO 39 MPH S
4/28 65/60/63/+12/.../0.0/.../..     54 S    AERO 54 MPH S
4/29 74/53/64/+13/0.00/0.0/.../..    37 S    AERO 37 MPH S
4/30 60/49/55/+3/0.00/0.0/.../..     28 WNW 
 
5/1  55/43/49/-3/0.00/0.0/.../..     30 NE
 
5/2  our morning low temp: 42F, the normal low is now 43F
 
DAILY RECORDS FOR APRIL 2011
4/17 - NEW RECORD PEAK GUST OF 63 MPH ESE;
surpasses the previous record of 58 MPH NW in 1994
4/27 - NEW RECORD HIGH MINIMUM TEMPERATURE OF 58F;
surpasses the previous record of 57F in 1900,1979
4/28 - NEW RECORD HIGH MINIMUM TEMPERATURE OF 60F;
surpasses the previous record of 57F in 1935,2009
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 2
HIGH 92F IN 2001
LOW 29F IN 1903
PRECIP 1.36 INCHES IN 2006
SNOWFALL 1.0 INS IN 1888
PEAK GUST 58 MPH S IN 1983
 
RECORDS FOR MAY 3
HIGH 92F IN 2001
LOW 31F IN 1888
PRECIP 2.25 INS IN 1900
SNOWFALL TRACE IN 1908, 1985
PEAK GUST 71 MPH W IN 2002
 
TODAY'S REPORT PREPARED BY: Robert Skilling