BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, APRIL 30, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME

COOLER DAY, LIGHT RAIN BEGINS BEFORE 1:00PM EST

Temperatures and dew points have been much lower compared to
yesterday.  The max. by 1:00PM was only 54F, and temps. had
dropped back down to 47F at the time of the observation.  Dew
points were in the upper 20s before light rain began in the
afternoon.

Light rain and distant fog dropped visibility to 10 miles in
some directions after a clear 80-mile start to the day.
Wind has been mainly out of the east since 7:00AM and was
gusting about 20 MPH.


Today's Observations:

7 A.M.
Weather: Few cumulus SSW-SW, scattered cirrus
Temperature: 49F; Dew Point: 27F; Wind: NNW at 8 kts
Sea-level pressure: 30.25 ins. Hg, rising, then more slowly
Visibility: 80 miles
6-hr Max temp: 58F
6-hr Min temp: 47F
24-hr precip: 0.00 in.
24-hr snowfall: 0.0 in.
BHO SA 1155 250 SCT 80 254/49/27/3408/025/ FEW CU SSW-SW/
8/101 51035 10058 20047

10 A.M.
Weather: Few cumulus W-WSW, scattered cirrus
Temperature: 51F; Dew Point: 29F; Wind: E at 10G20 kts
Sea-level pressure: 30.29 ins. Hg, rising then steady 
Visibility: 70 miles
BHO SA 1455 250 SCT 70 258/51/29/0810G20/029/ FEW CU W-WSW/ 
8/101 50004

1 P.M.
Weather: Light rain, broken nimbostratus, broken altocumulus
Temperature: 47F; Dew Point: 34F; Wind: NE at 8 kts
Sea-level pressure: 30.32 ins. Hg, falling then rising
Visibility: 40 miles, except 10 miles S-WNW, distant fog S-WNW
6-hr Max temp: 54F
6-hr Min temp: 47F
6-hr precip: Trace
6-hr snowfall: 0.0 in.
BHO SA 1755 E59 BKN 100 BKN 40R- 268/47/34/0408/032/ VSBY S-WNW 10
DSNT FG S-WNW/ 8/670 53010 MANUAL 600// 10054 20047


SUMMARY FOR SATURDAY, APRIL 29, 2017
 
TEMPERATURE (DEGREES F)
MAX.....83   NORMAL.....61
MIN.....60   NORMAL.....43
MEAN....72   NORMAL.....52

DEPARTURE FROM 30-YEAR NORMAL........................+20
TOTAL DEPARTURE FOR THE MONTH.......................+137 [+4.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE.........-13
TOTAL HEATING UNITS FOR THE MONTH.............418   DEPARTURE........-120
TOTAL HEATING UNITS FOR THE SEASON...........5320   DEPARTURE........-702
TOTAL HEATING UNITS LAST SEASON TO DATE......4977   DIFFERENCE.......+343

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................43 WNW AT 4:48 P.M.
                   AERO........................46 WNW AT 5:28 P.M.
                   ASOS........................46 WNW AT 4:46 P.M.
                   DAVIS.......................42 NW  AT 4:45 P.M. RMY 47
FASTEST MILE FOR YESTERDAY.....................35 WNW AT 4:47 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................32 W   AT 4:48 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................33 WNW AT 4:49 P.M.
AVERAGE WIND SPEED AND DIRECTION.............15.3 W
                   ASOS......................14.7
                   DAVIS.....................13.7 W [280 deg.]

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..........6.65  DEPARTURE......+2.23
                         ASOS..............6.76
TOTAL PRECIPITATION FOR THE YEAR..........20.77  DEPARTURE......+2.35
                         ASOS...............N/A ***
*** ASOS annual total not available due to erroneous readings

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........0.0
TOTAL SNOWFALL FOR THE MONTH................2.7  DEPARTURE.......-0.3
TOTAL SNOWFALL FOR THE SEASON..............66.4  DEPARTURE.......+3.7


PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
M:    Missing data

4/1  35/31/33/-8/2.21/2.7/000/00           40 ENE AERO 41 ENE RMY 41
4/2  53/30/42/+1/0.00/0.0/552/72           32 NW  AERO 33 NW  RMY 34
4/3  60/35/48/+6/0.00/0.0/685/89           21 W*  AERO 20 NW  RMY N/A
4/4  42/35/39/-3/0.78/0.0/000/00           41 ESE AERO 43 ESE RMY 42
4/5  41/35/38/-5/0.00/0.0/000/00           21 NNW AERO 20 NNW RMY N/A
4/6  55/35/45/+2/1.27/0.0/000/00           35 SSE AERO 37 S   RMY 37  TSTM
4/7  53/38/46/+3/0.00/0.0/226/29           43 SSW AERO 47 SSW RMY 48
4/8  50/34/42/-2/0.00/0.0/666/85           37 WNW AERO 40 WNW RMY 39
4/9  65/34/50/+6/0.00/0.0/716/91           23 W   AERO 23 W   RMY N/A
4/10 77/45/61/+16/0.00/0.0/560/71          37 S   AERO 37 S   RMY 39
4/11 85/50/68/+23/0.00/0.0/642/81          28 S   AERO 28 S   RMY 30
4/12 68/47/58/+13/0.01/0.0/382/48          26 WNW AERO 28 WNW RMY N/A
4/13 58/39/49/+3/0.00/0.0/567/71           28 WNW AERO 31 NW  RMY 30 
4/14 62/40/51/+5/0.00/0.0/801/100          22 NNW AERO 22 NNW RMY 24
4/15 68/40/54/+7/0.01/0.0/675/84           40 SSW AERO 45 SSW RMY 45
4/16 86/55/71/+24/T/0.0/758/94             38 W*  AERO 39 SW  RMY 42
4/17 75/48/62/+15/0.00/0.0/405/50          37 W   AERO 37 W   RMY 43
4/18 52/35/44/-4/0.00/0.0/779/96           25 ENE AERO 23 ENE RMY 25
4/19 54/34/44/-4/0.06/0.0/431/53           31 S   AERO 33 S   RMY 34
4/20 58/41/50/+1/0.05/0.0/270/33           25 SSW AERO 24 SSW RMY 23
4/21 45/42/44/-5/0.50/0.0/000/00           26 ESE AERO 29 ESE RMY 28
4/22 44/40/42/-7/0.14/0.0/.../..           22 NE  AERO 22 NNE RMY 20
4/23 65/37/51/+1/0.00/0.0/.../..           28 S   AERO 26 S   RMY 28
4/24 69/42/56/+6/0.00/0.0/.../..           23 SSW*AERO 22 SSW*RMY N/A
4/25 49/42/46/-4/..../0.0/.../..           35 NE  AERO 36 NE  RMY 35
4/26 60/47/54/+3/..../0.0/.../..           29 ENE AERO 28 ENE RMY N/A
4/27 66/50/58/+7/0.00/0.0/.../..           20 S   AERO 20 S   RMY N/A
4/28 81/56/69/+17/.../.../.../..           25 W   AERO 23 W   RMY 26
4/29 83/60/72/+20/0.00/0.0/.../..          43 WNW AERO 46 WNW RMY 47

4/30 Low temp since midnight is 47F; normal low is now 52F


DAILY RECORDS FOR APRIL 2017

4/11/17: DAILY RECORD MAXIMUM TEMPERATURE OF 85F,
         BREAKS PREVIOUS RECORD OF 78F SET IN 1945

4/11/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 50F,
         TIES WITH PREVIOUS RECORD SET IN 1955

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 1905,1917,1921,1995,2016
PEAK GUST 57 MPH NW IN 1974

TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle