BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, APRIL 30, 2012
ALL TIMES ARE IN EASTERN STANDARD TIME
 
HIGH CLOUDS ON THE INCREASE TODAY AFTER CLEAR MORNING
DEW POINTS FELL TO SINGLE NUMBERS ON SUNDAY AND THE
RELATIVE HUMIDITY WAS IN THE TEENS
WARM BUI NOT THE WARMEST APRIL
 
High clouds were increasing today ahead of the next
weather system which promises some light amount of
rainfall.  Sunday was an especially dry day with
dew points down to the single numbers for a time and
the relative humidity in the teens.
April will likely rank in the top five warmest on
record after today's numbers are in.
 
April continues much warmer than average, though the cool
temperatures occurring in the last days of the month will lower
the mean somewhat.  April will still end up among the warmest on
record. Through the 29th, the corrected mean temperature for
April 2012 is 50.0 deg F.
 
Warmest April, 1885-2011 (deg F)
 
1) 51.5 in 2010
2) 51.0 in 1976
3) 49.4 in 1945
4) 49.0 in 1994
5) 48.9 in 2009
   48.9 in 2005
 
Today's observations:
 
7 A.M.
Weather: Clear, patch thin cirrus WSW-WNW
Temperature: 44F, Dew point: 18F, Wind: WNW at 7 kts,
Wind: Direction variable W-NNW
Sea-level pressure: 30.32 inches Hg, rising then more rapidly
Visibility: 75 miles
6-hour min. temp: 35F
BHO SA 1155 CLR 75 267/44/18/3007/032/ PTCH THN CI WSW-WNW LGT DSNT HZ
WND 27V33/ 8/001 53020 10044 20035
 
10 A.M.
Weather: Thin scattered cirrus, layer SSW-NW,
invading, few cirrus overhead  
Temperature: 51F, Dew Point: 17F; Wind: NNW at 3 kts,
Wind: Light
Sea-level pressure: 30.31 inches Hg, falling
Visibility: 80 miles   
BHO SA 1455 250 –SCT 80 263/51/17/3303/031/ FEW CI OVHD
CI LYR SSW-NW INVADING FRM NW LGT DSNT HZ WND L/V/ 8/005 58004
 
1 P.M. 
Weather: Scattered dense cirrus, (2 layers), broken cirrus,
thin overcast cirrostratus, lone patch altocumulus
lenticularis E, break in overcast distant NNE-ESE 
Temperature: 57F, Dew Point: 19F; Wind: WNW at 6 kts,
Wind: Wind light
Sea-level pressure: 30.26 inches Hg, falling 
Visibility: 70 miles, light distant
6-hour max. temp: 59F
BHO SA 1755 220 SCT 250 SCT 300 -OVC 70 247/57/19/2906/026/
LONE PTCH ACSL E PTCHS DNS CI ALQDS PTCH CC OVHD BINOVC DSNT NNE-ESE
INCRSNG LGT DSNT HZ WND LGT/ 8/047 10059 20044
 
WEATHER SUMMARY FOR SUNDAY, APRIL 29
 
TEMPERATURE (DEGREES F)
MAX.....58    NORMAL.....61
MIN.....36    NORMAL.....43
MEAN....47    NORMAL.....52
 
DEPARTURE FROM 30-YEAR NORMAL.......................-5
TOTAL DEPARTURE FOR THE MONTH.....................+134 [+4.4 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY..............18   DEPARTURE..........+4
TOTAL HEATING UNITS FOR THE MONTH.............412   DEPARTURE........-136
TOTAL HEATING UNITS FOR THE SEASON...........4697   DEPARTURE.......-1315
TOTAL HEATING UNITS LAST SEASON TO DATE......5885   DIFFERENCE......-1188
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............38 NW AT  5:23 P.M. *
                   AERO..................42 NW AT  5:23 P.M. 
                   ASOS..................40 NW AT  5:23 P.M.
                   DAVIS.................40 NW AT  5:23 P.M. A.M. RMY 42
THE FASTEST MILE FOR YESTERDAY...........30 NW  AT  5:22 P.M. * 
MAXIMUM 2-MINUTE ASOS AVERAGE............31 NW  AT  5:23 P.M.
DAVIS MAXIMUM 2-MINUTE AVERAGE...........30 NW  AT  5:23 P.M.
AVERAGE WIND SPEED AND DIRECTION.......13.8 WNW
                   ASOS................12.7
                   DAVIS...............11.6 NW  [310 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..........3.52   DEPARTURE..........-0.90
                         ASOS..............3.58
TOTAL PRECIPITATION FOR THE YEAR...........9.61   DEPARTURE..........-8.81
                         ASOS..............9.73
     
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0    DEPARTURE..........-0.1
TOTAL SNOWFALL FOR THE MONTH................0.0    DEPARTURE..........-3.0
TOTAL SNOWFALL FOR THE SEASON..............24.2    DEPARTURE.........-35.7
 
PRELIMINARY CLIMATE SUMMARY FOR APRIL 2012 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
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
4/1  50/34/42/+1/0.14/0.0/360/47    20 SSW AERO 20 MPH SSW RMY N/A
4/2  51/35/43/+2/0.04/T/353/46      35 NNW AERO 33 MPH NNW RMY 35
4/3  57/31/44/+2/0.00/0.0/724/94    36 NW  AERO 37 MPH NW  RMY 40
4/4  62/38/50/+8/T/0.0/688/89       40 NW  AERO 39 MPH NW  RMY 43
4/5  51/33/42/-1/0.00/0.0/660/85    29 NW  AERO 27 MPH NW  RMY 30
4/6  51/31/41/-2/0.00/0.0/623/80    26 NNW AERO 26 MPH NNW RMY 28
4/7  54/32/43/0/0.00/0.0/305/39     31 NW  AERO 32 MPH NW  RMY 32
4/8  51/37/44/0/0.00/0.0/086/11     32 NW  AERO 31 MPH NW  RMY 33
4/9  57/43/50/+6/T/0.0/323/41       44 W   AERO 42 MPH W   RMY 44
4/10 61/40/51/+6/0.00/0.0/600/76    32 W   AERO 31 MPH W   RMY 34
4/11 57/40/49/+4/0.00/0.0/397/50    21 NE  AERO 20 MPH NE  RMY 22
4/12 54/39/47/+2/0.16/0.0/127/16    25 NNW AERO 24 MPH NNW RMY 28
4/13 63/36/50/+4/0.00/0.0/782/98    24 W   AERO 23 MPH W   RMY 25
4/14 70/44/57/+11/0.00/0.0/617/77   25 SSW AERO 27 MPH SSW RMY 28
4/15 75/52/64/+17/T/0.0/426/53      23 W   AERO 23 MPH W   RMY 25
4/16 89/57/73/+26/0.01/0.0/678/84   28 SSW AERO 30 MPH SSW RMY 32
4/17 83/53/68/+21/0.00/0.0/777/96   28 W   AERO 28 MPH W   RMY 32
4/18 61/45/53/+5/0.00/0.0/487/60    27 NNW AERO 27 MPH NNW RMY N/A
4/19 70/44/57/+9/0.00/0.0/676/83    23 S   AERO 22 MPH S   RMY 25
4/20 75/46/61/+12/0.00/0.0/768/94   30 S   AERO 31 MPH S   RMY 33
4/21 75/51/63/+14/T/0.0/508/62      32 S   AERO 37 MPH SSW RMY 38
4/22 59/41/50/+1/1.16/0.0/000/00    50 NE  AERO 51 MPH NE  RMY 52
4/23 61/42/52/+2/1.99/0.0/000/00    46 NE  AERO 47 MPH NE  RMY 48
4/24 57/43/50/0/0.00/0.0/.../..     37 SSW AERO 42 MPH S   MMY N/A
4/25 61/41/51/+1/T/0.0/.../..       32 W   AERO 33 MPH W   RMY 32
4/26 66/36/51/0/0.01/0.0/.../..     29 SSW AERO 31 MPH SSW RMY N/A
4/27 56/36/46/-5/0.01/0.0/.../..    39 W   AERO 41 MPH W   RMY 42
4/28 58/31/45/-7/0.00/0.0/.../..    30 WNW AERO 35 MPH WNW RMY 31
4/29 58/36/47/-5/0.00/0.0/.../..    38 NW  AERO 42 MPH NW  RMY 42
 
4/30 our morning low temp: 35F; the normal low is now 43F
 
DAILY RECORDS FOR APRIL 2012
4/16 - NEW DAILY RECORD HIGH MAXIMUM TEMP OF 89F;
surpasses the previous record of 87F in 1896.
4/23 - NEW DAILY RECORD PRECIPITATION OF 1.99 INCHES;
surpasses the previous record of 1.51 inches in 1998.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR APRIL 30
HIGH 86 IN 1942
LOW 30 IN 1931
PRECIP 1.41 IN 1991
SNOWFALL 0.3 IN. IN 1909
PEAK GUST 64e MPH NW IN 1978
 
RECORDS FOR MAY 1
HIGH 87F IN 1899
LOW 29F IN 1978
PRECIP 2.53 INCHES IN 1921
SNOWFALL TRACE IN 1905,1917,1921,1995.
PEAK GUST 57 MPH NW IN 1974
 
TODAY'S REPORT PREPARED BY: Robert Skilling/Patrick Peters