BLUE HILL METEOROLOGICAL OBSERVATORY 
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 16, 2011
ALL TIMES ARE IN EASTERN STANDARD TIME
 
HEAVILY OVERCAST WITH STRATUS CLOUDS
EARLY MORNING RAIN THEN SOME VERY LIGHT DRIZZLE
VERY COOL TEMPS. STUCK IN MID-40'S
GUSTY N-NNE WINDS UP TO 35 MPH
 
The total rainfall from the precipitation event
which began very early Sunday morning was 0.97 inch
through 8 A.M. EDT today.  Some light drizzle added
just 0.01 inch during the next six hours. Temperatures
were running some 20 degrees cooler than normal early
this after and for all three of our regularly scheduled
observations at 8 a.m., 11 a.m. and 2 p.m. EDT it was a very
cool 45 degrees.  North gradually veering to northeast
winds were reaching peak gusts from 30 to 35 MPH.  
 
Today's observations:
 
7 A.M.  
Weather: Sky obscured in dense fog, light drizzle,
drizzle began at 6:25 A.M. EST
Temperature: 45F, Dew point: 45F; Wind: N at 9G23 kts
Sea-level pressure: 29.75 inches Hg, steady
Visibility: 1/16 mile variable to 1/8 mile, dense fog,
light drizzle
6-hour min. temp: 45F
6-hour precip: 0.04 in.
24-hour precip: 0.64 in.  
BHO SA 1155 W3 X 1/16VL-F 102/45/45/0209G23/983/ VSBY 1/16V1/8/
LE25/ 8//// 53019 ASOS 60004 MANUAL 6004/ ASOS 70062 MANUAL 70064
10046 20045
 
10 A.M.  
Weather: Sky obscured in dense fog, drizzle
ended past hour
Temperature: 45F, Dew point: 45F; Wind: NNE at 8G22 kts,
Sea-level pressure: 29.88 inches Hg, rising
Visibility: 1/8 mile in fog
3-hourly precip: 0.01 in.
BHO SA 1455 W3 X 1/8F 117/45/45/0208G22/988/ LEUKN/ 8////
53015 MANUAL 6001/ ASOS 60001 
 
1 P.M.  
Weather: Low overcast stratus, ceiling ragged,
stratus drifting over summit  
Temperature: 45F, Dew point: 45F; Wind: NNE at 16G26 kts,
Wind: Peak wind from NNE @ 27 kts at 12:41 P.M. EST,
Wind: Direction variable NNW to ENE 
Sea-level pressure: 29.86 inches Hg, falling
Visibility: 1 mile, 1/4 mile N-NE, lowering
6-hourly max. temp: 47F
6-hourly precip: 0.01 in. 
BHO SA 1755 E3 OVC 1F 113/45/45/0216G26/986/ CIG RGD
STRA DRFTG OVR SMT VSBY N-NE 1/4 LWRG PK WND 0227/41/
8/6// 56004 MANUAL 6001/ ASOS 60001 10047 20045
                                                                                   
WEATHER SUMMARY FOR SUNDAY, MAY 15
 
TEMPERATURE (DEGREES F)
MAX.....63     NORMAL.....67
MIN.....47     NORMAL.....47
MEAN....55     NORMAL.....57
 
DEPARTURE FROM 30-YEAR NORMAL...................-2
TOTAL DEPARTURE FOR THE MONTH...................+2 [-0.1 DEGREE/DAY]
 
HEATING DEGREE DAYS    
TOTAL HEATING UNITS FOR YESTERDAY............10    DEPARTURE........+1
TOTAL HEATING UNITS FOR THE MONTH...........157    DEPARTURE........-8
TOTAL HEATING UNITS FOR THE SEASON.........6052    DEPARTURE......-139
TOTAL HEATING UNITS LAST SEASON TO DATE....5596    DIFFERENCE.....+456
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..............23 NNE AT  7:50 P.M.  
                   AEROVANE...............23 NNE AT  7:50 P.M. *  
                   ASOS...................21 NNE AT  7:50 P.M. 
                   DAVIS..................21 NNE AT  7:59 P.M. 
THE FASTEST MILE FOR YESTERDAY............16 NE  AT  6:36 P.M. **
MAXIMUM 2-MINUTE ASOS AVERAGE.............17 NE  AT  6:36 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE............14 N   AT  10-11 P.M.  
AVERAGE WIND SPEED AND DIRECTION.........9.2 SE
                   ASOS..................9.2    
                   DAVIS.................9.0 ESE [110 DEG]
* Last of several occurrences
** estimated due to power failure
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.64  DEPARTURE........+0.52
                         ASOS..............0.62  
TOTAL PRECIPITATION FOR THE MONTH..........2.27  DEPARTURE........+0.42
                         ASOS..............2.21
TOTAL PRECIPITATION FOR THE YEAR..........20.49  DEPARTURE........+0.6917
                        ASOS..............21.17**
**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.........0.0
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE........-0.1
TOTAL SNOWFALL FOR THE SEASON..............96.8  DEPARTURE.......+36.7
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 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
 
5/1  55/43/49/-3/0.00/0.0/819/97     30 NE
5/2  73/42/58/+6/0.00/0.0/651/77     24 SSW
5/3  74/51/63/+10/0.00/0.0/441/52    31 SSE
5/4  63/44/54/+1/0.57/0.0/000/00     35 SSE
5/5  58/41/50/-3/0.02/0.0/264/31     47 W
5/6  70/43/57/+3/0.00/0.0/667/78     41 SSE  AERO 41 MPH SSE
5/7  71/48/60/+6/0.50/0/0/326/38     29 WNW  TSTM 
5/8  54/48/51/-3/0.00/0.0/238/27     31 NE
5/9  67/47/57/+2/T/0.0/.../..        43 N
5/10 53/46/50/-5/.../0.0/.../..      50 N
5/11 59/45/52/-3/.../0.0/.../..      37 NNE
5/12 57/48/53/-3/T/0.0/.../..        30 NNE
5/13 64/46/55/-1/0.00/0.0/.../..     22 NE
5/14 64/43/54/-3/T/0.0/.../..        22 SSE
5/15 63/47/55/-2/..../0.0/000/00     23 NE 
 
5/16 our morning low temp: 45F; the normal low is now 47F
 
DAILY RECORDS FOR MAY 2011
None so far...
 
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
PRECIP 2.07 INS IN 1916
PEAK GUST 52 MPH SW IN 1967, W IN 1974
 
TODAY'S REPORT PREPARED BY: Robert Skilling