BLUE HILL METEOROLOGICAL OBSERVATORY 
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MARCH 15, 2011
ALL TIMES ARE IN EASTERN STANDARD TIME
 
COMPLETE SUNSHINE WITH NEAR NORMAL TEMPS.
CONSIDERABLE FROST THIS MORNING AS
TEMPERATURE INVERSION PREVAILED OVERNIGHT
 
After a frosty start the day has turned nice and
completely sunny with near normal temperatures.
Early morning frost covered wood and grassy
surfaces throughout the area including here at
the summit. Our low of 28F was just one degree
above the normal for the date and by early this
afternoon the high of 45F was also within one
degree of normal. An early morning temperature
inversion brought temperatures down into the low
20's in the surrounding countryside.
 
Sunshine has been complete right from sunrise.
Quite a nice change from yesterday when
only a few glimpses of sun showed through during
the afternoon after the snow flurries ended.
There was no measurable snow even up here despite
the fact there was 0.01 inch of melted precipitation.
 
Today's observations:
 
7 A.M.  
Weather: Clear, stratus, stratocumulus layer distant SW-NNW, 
cirrus layer distant SW increasing, frost grassy and wood surfaces 
Temperature: 32F, Dew point: 27F; Wind: ESE at 3 kts
Sea-level pressure: 30.50 ins Hg, rising
Visibility: 20 miles, except 15 miles SW-NW adn 35 miles northeast,
thin fog below inversion  
24-hour precip: 0.01 inch
24-hour snowfall: trace 
BHO SA 1155 CLR 20 330/32/27/1203/050/ STRA/FEW LYR ALG HRZN DSNT 
SW-NNW CI LYR DSNT SW INVADING THN FG BLO INVSN VSBY SW-NW 15 NE 35 
FROST GRASSY/WOODEN SFCS/ 8/605 51008 ASOS 70001 MANUAL 70001
10032 20028
 
10 A.M.  
Weather: Thin scattered high cirrus, small cumulus forming E-SSE,
stratocumulus/cumulus extending SW-N and few NE
Temperature: 39F, Dew point: 26F; Wind: SE at 6 kts  
Sea-level pressure: 30.52 inches Hg, rising
Visibility:  35 miles,  distant haze   
BHO SA 1455 300 –SCT 35 335/39/26/1406/952/ SML CU FRMG E-SSE SC/CU 
XTDNG SW-N-FEW NE CI SE-W INVADING DSNT HZ/ 8/806 53005
 
1 P.M.   
Weather: Scattered thin cirrus, stratocumulus, few cumulus,
S-W-N-OVHD, cirrus slowly invading sky 
Temperature: 43F, Dew point: 25F; Wind: SE at 5 kts
Sea-level pressure: 30.47 inches Hg, falling
Visibility: 35 miles, distant haze   
6-hour max. temp. 45F 
BHO SA 1755 250 –SCT 35 319/43/25/1305/047/ SC FEW CU S-W-N-OVHD
CI S-WNW INVADING DSNT HZ/ 8/805/ 58016 10045 20032 
 
WEATHER SUMMARY FOR MONDAY, MARCH 14
 
TEMPERATURE (DEGREES F)
MAX.....37     NORMAL.....44
MIN.....28     NORMAL.....27
MEAN....33     NORMAL.....36
 
DEPARTURE FROM 30-YEAR NORMAL...................-3
TOTAL DEPARTURE FOR THE MONTH..................+34 [+2.2 DEGREES/DAY]
 
HEATING DEGREE DAYS    
TOTAL HEATING UNITS FOR YESTERDAY............32    DEPARTURE........+3
TOTAL HEATING UNITS FOR THE MONTH...........405    DEPARTURE.......-36
TOTAL HEATING UNITS FOR THE SEASON.........4927    DEPARTURE.......-84
TOTAL HEATING UNITS LAST SEASON TO DATE....4758    DIFFERENCE.....+169
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..............20 NW  AT   3:17 A.M.  
                   AEROVANE...............23 NW  AT   3:13 A.M.  
                   ASOS...................20 NW  AT   3:13 A.M.   
                   DAVIS..................23 WNW AT   3:13 A.M.   
THE FASTEST MILE FOR YESTERDAY............12 NE  AT  11:38 A.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE.............15 NE  AT  11:36 A.M.     
MAXIMUM 2-MINUTE DAVIS AVERAGE............16 WNW AT   3:07 A.M.     
AVERRAGE WIND SPEED AND DIRECTION....... 7.2 NE
                   ASOS..................7.0               
                   DAVIS.................7.4 N [355 DEG]
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.01   DEPARTURE.......-0.15
                         ASOS..............0.00   
TOTAL PRECIPITATION FOR THE MONTH..........1.33   DEPARTURE.......-0.78
                           ASOS............1.39   
TOTAL PRECIPITATION FOR THE YEAR..........12.26   DEPARTURE.......+1.31
                        ASOS..............13.00**
** 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........Trace  DEPARTURE........-0.4
TOTAL SNOWFALL FOR THE MONTH..............Trace  DEPARTURE........-6.2
TOTAL SNOWFALL FOR THE SEASON..............89.7  DEPARTURE.......+38.1
 
PRELIMINARY CLIMATE SUMMARY FOR MARCH 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
 
3/1  36/27/32/0/0.00/0.0/580/86      37 WNW  AERO 40 MPH WNW
3/2  45/18/32/0/T/T/264/39           51 W    AERO 53 MPH W
3/3  27/8/18/-14/0.00/0.0/659/97     36 WNW  AERO 40 MPH WNW
3/4  37/15/26/-7/0.00/0.0/540/79     24 SSE
3/5  53/27/40/7/T/0.0/158/23         48 SSW  AERO 53 MPH SSW
3/6  59/46/53/+20/0.16/0.0/028/04    48 S    AERO 56 MPH S
3/7  54/25/40/+7/0.64/T/159/23       58 SE   AERO 62 MPH SSE
3/8  41/22/32/-2/0.00/0.0/638/92     23 NW 
3/9  34/28/31/-3/T/T/049/07          31 NE   AERO 32 MPH NE
3/10 40/32/36/+2/.../T/000/00        37 E    AERO 39 MPH E
3/11 54/40/47/+12/.../0.0/000/00     40 E    AERO 40 MPH E
3/12 51/34/43/+8/0.00/0.0/550/78     35 SW   AERO 37 MPH WSW 
3/13 48/36/42/+7/T/0.0/326/46        39 W    AERO 42 MPH W
3/14 37/28/33/-3/0.01/T/021/03       20 NW
 
3/15 our morning low temp: 28F; the normal low is now 27F
 
DAILY RECORDS FOR MARCH 2011
None so far
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MARCH 15
HIGH 80 IN 1990
LOW 6 IN 1993
PRE 2.86 INS. IN 2010 
SNOW 12.0 INS. 1967
WIND 73e MPH ESE IN 1940
 
RECORDS FOR MARCH 16
HIGH 73 IN 1990
LOW 8 IN 1932
PRE 1.95 INS. IN 1900
SNOW 10.0 INS. IN 1896
WIND 79 MPH NE IN 1956
 
TODAY'S REPORT PREPARED BY: Robert Skilling