BLUE HILL METEOROLOGICAL OBSERVATORY 
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 3, 2011
ALL TIMES ARE IN EASTERN STANDARD TIME
 
WARM TEMPERATURES, INCREASING MOISTURE
ON SOUTHERLY WINDS
 
With a morning low of 51F and an afternoon high of 74F through 2PM EDT,
temperatures are running close to 10 degrees above average for the
date.  Along with the warm air, southerly winds are transporting more
moisture into the region.  The dew point temperature has risen from
the low 40s early this morning into the low 50s this afternoon.
Hazy conditions are becoming more apparent as visibility has gradually
decreased to 40 miles this afternoon.
 
APRIL 2011 PRELIMINARY STATS
Average Max Temp:  56.6F [+1.1F]
Average Min Temp:  39.9F [+2.8F]
Mean Temp:  48.3F [+2.0F]
24-hr. Corr Mean Temp:  47.6F
Max Temp:  78F on 27th
Min Temp:  31F on 1st, 6th, 15th, 16th
Total precipitation:  4.61 ins. [+0.29 in.]
Total snowfall:  1.6 ins. [-1.5 ins. ]
Greatest 24-hour snowfall:  4.6 ins. (31st-1st)
Total heating degree day units (month):   497  [-65]
Total heating degree day units (season): 5895 [-131]
Avg wind speed:  13.9 MPH S 15%
Avg corrected wind speed:  14.2 MPH S
Peak gust:  63 MPH ESE on 17th
Peak fastest mile:  42 MPH ESE on 17th, 42 MPH S on 28th
Sunshine (astronomical):  10,227 minutes; 42% of total possible
Sunshine (Campbell-Stokes):  9,858 minutes; 42% of possible 23,250
 
Today's observations:
 
7 A.M.  
Weather: Scattered stratocumulus, scattered altocumulus, broken
cirrostratus, few altocumulus lenticularis distant NNW-ENE,
cirrostratus layer distant ENE-S, thin smoke layer distant NNW-E and
distant SE-WSW, distant haze
Temperature: 55F, Dew point: 45F; Wind: S at 4 kts
Sea-level pressure: 30.18 inches Hg, rising
Visibility: 45 miles, distant haze  
6-hour min. temp: 51F  
BHO SA 1155 60 SCT 100 SCT E220 BKN 250 –BKN 45 221/55/45/1904/018/
FEW ACSL DSNT NNW-ENE CS LYR DSNT ENE-S THN K LYR DSNT NNW-E AND
DSNT SE-WSW DSNT HZ/ 8/542 52017 10055 20051
 
10 A.M.  
Weather: Scattered stratocumulus, scattered altocumulus, thin broken
cirrus, stratocumulus layer distant NE-SSE, altocumulus/altocumulus
lenticularis distant WNW-NNE, distant haze 
Temperature: 68F, Dew point: 50F; Wind: ESE at 7 kts
Wind: Direction variable ENE-SE
Sea-level pressure: 30.16 inches Hg, falling 
Visibility: 45 miles, distant haze 
BHO SA 1455 60 SCT 100 SCT 250 –BKN 45 214/68/50/1207/016/ SC LYR
DSNT NE-SSE AC/ACSL DSNT WNW-NNE DSNT HZ WND 07V13/ 8/541 58007
 
1 P.M.  
Weather: Scattered stratocumulus, scattered altocumulus/altocumulus
lenticularis, scattered altostratus, broken cirrostratus, broken thin
cirrus, few cumulus distant E-S, few altocumulus lenticularis distant
all quadrants except ESE-SSW, cirrostratus layer SSE-W-NNE and overhead
invading the sky, partial halo, distant haze
Temperature: 72F, Dew point: 52F; Wind: SE at 10 kts,
Wind: Direction variable E-SSE
Sea-level pressure: 30.13 inches Hg, falling
Visibility: 40 miles, distant haze
6-hour max. temp: 74F
BHO SA 1755 50 SCT 80 SCT 120 SCT E200 BKN 250 –BKN 40
204/72/52/1310/013/ FEW CU DSNT E-S FEW ACSL DSNT ALQDS XCPT ESE-SSW
CS LYR SSE-W-NNE AND OVHD INVADING PARTIAL HALO DSNT HZ WND 09V15/
8/847 58010 10074 20055
 
WEATHER SUMMARY FOR MONDAY, MAY 2
 
TEMPERATURE (DEGREES F)
MAX.....73     NORMAL.....62
MIN.....42     NORMAL.....43
MEAN....58     NORMAL.....52
 
DEPARTURE FROM 30-YEAR NORMAL...................+6
TOTAL DEPARTURE FOR THE MONTH...................+3 [+1.3 DEGREES/DAY]
 
HEATING DEGREE DAYS    
TOTAL HEATING UNITS FOR YESTERDAY.............7    DEPARTURE........-6
TOTAL HEATING UNITS FOR THE MONTH............23    DEPARTURE........-3
TOTAL HEATING UNITS FOR THE SEASON.........5918    DEPARTURE......-134
TOTAL HEATING UNITS LAST SEASON TO DATE....5482    DIFFERENCE.....+436
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY..............24 SSW AT 10:08 P.M. 
                   AEROVANE...............27 SSW AT 10:09 P.M.  
                   ASOS...................23 SSW AT 10:09 P.M.
                   DAVIS..................23 SSW AT 10:09 P.M. 
THE FASTEST MILE FOR YESTERDAY............17 SSW AT 10:12 P.M. * 
MAXIMUM 2-MINUTE ASOS AVERAGE.............17 SW  AT 10:13 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE............18 SSW AT 10:12 P.M. 
AVERAGE WIND SPEED AND DIRECTION.........8.5 S
                   ASOS..................8.4  
                   DAVIS.................7.7 SSW [212 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 THE MONTH..........0.00  DEPARTURE........-0.26
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE YEAR..........18.22  DEPARTURE........+0.01
                        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.........0.0
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE........-0.1
TOTAL SNOWFALL FOR THE SEASON..............96.8  DEPARTURE.......+36.7
 
PRELIMINARY CLIMATE SUMMARY FOR APRIL & 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
 
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/+14/0.05/0.0/297/36    39 WSW  AERO 41 MPH W
4/25 56/45/51/+1/0.06/0.0/008/01      17 NE
4/26 64/45/55/+5/T/0.0/357/43        24 NNE 
4/27 78/58/68/+18/0.01/0.0/375/45    36 S    AERO 39 MPH S
4/28 65/60/63/+12/0.04/0.0/000/00     54 S    AERO 54 MPH S
4/29 74/53/64/+13/0.00/0.0/662/79    37 S    AERO 37 MPH S
4/30 60/49/55/+3/0.00/0.0/320/38     28 WNW 
 
5/1  55/43/49/-3/0.00/0.0/.../..     30 NE
5/2  73/42/58/+6/0.00/0.0/.../..     24 SSW
 
5/3  our morning low temp: 51F, 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 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 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
 
RECORDS FOR MAY 4
HIGH 90F IN 2001
LOW 27F IN 1911 (RECORD FOR MAY)
PRECIP 1.92 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966
 
TODAY'S REPORT PREPARED BY: Sean Fankhauser / Caroline Corbett