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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 9, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME

LOWER CLOUDS MOVE IN THIS AFTERNOON

Today's temperatures copied yesterday's almost exactly 
with a max of 53F by 1:00PM EST after a morning minimum
of 36F.  Temperatures are on trend to be about 10F below
normal.

Skies began partly sunny this morning, but thick strato-
cumulus had moved in by afternoon and were blocking most
of the sunshine.  Despite the clouds and observed distant
showers and virga, no precip. had fallen by the 1:00PM ob.

Winds remained light all day and varied direction from NW
at 7:00AM to ESE at 1:00PM.


Today's Observations:

7 A.M.
Weather: Scattered altocumulus, broken cirrostratus, distant 
virga SSE-SSW
Temperature: 45F; Dew Point: 30F; Wind: NW at 4 kts,
Wind Speed: Light
Sea-level pressure: 29.99 ins. Hg, steady then rising
Visibility: 70 miles
6-hr Max temp: 45F
6-hr Min temp: 36F
24-hr precip: 0.00 in.
BHO SA 1155 120 SCT E200 BKN 70 156/45/30/3104/999/ DSNT VIRGA 
SSE-SSW WND LGT/ 8/096 53005 10045 20036

10 A.M.
Weather: Scattered stratocumulus, broken altocumulus, distant 
showers SSE-SSW
Temperature: 51F; Dew Point: 27F; Wind: WSW at 4 kts,
Wind Speed: Light
Sea-level pressure: 30.01 ins. Hg, rising then steady
Visibility: 70 miles, except 50 miles SSE-SSW
BHO SA 1455 44 SCT E74 BKN 70 161/51/27/2404/001/ VSBY SSE-SSW 50 
DSNT SHWRS SSE-SSW WND LGT/ 8/560 53005

1 P.M.
Weather: Few cumulus SW, broken stratocumulus, virga WNW 
Temperature: 50F; Dew Point: 31F; Wind: estimated ESE at 3 kts,
Wind speed: Light
Sea-level pressure: 29.98 ins. Hg, falling, then more quickly
Visibility: 70 miles
6-hr Max temp: 53F
6-hr Min temp: 45F
BHO SA 1755 E54 BKN 70 154/50/31/E0603/998/ FEW CU SW VIRGA WNW 
WND LGT/ 8/500 56007 10053 20045


SUMMARY FOR MONDAY, MAY 8, 2017
 
TEMPERATURE (DEGREES F)
MAX.....54   NORMAL.....64
MIN.....38   NORMAL.....45
MEAN....46   NORMAL.....55

DEPARTURE FROM 30-YEAR NORMAL.........................-9
TOTAL DEPARTURE FOR THE MONTH........................-17 [-2.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............19   DEPARTURE..........+8
TOTAL HEATING UNITS FOR THE MONTH.............106   DEPARTURE.........+13
TOTAL HEATING UNITS FOR THE SEASON...........5439   DEPARTURE........-688
TOTAL HEATING UNITS LAST SEASON TO DATE......5137   DIFFERENCE.......+302

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................29 WSW AT 10:18 A.M.
                   AERO........................29 WSW AT 12:05 P.M.
                   ASOS........................31 WSW AT 10:19 A.M.
                   DAVIS.......................30 WSW AT 12:04 P.M. RMY 32
FASTEST MILE FOR YESTERDAY.....................22 WSW AT 10:09 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................22  W  AT  3:52 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................21 WSW AT 10:11 A.M.
AVERAGE WIND SPEED AND DIRECTION.............12.8  W
                   ASOS......................12.8
                   DAVIS.....................11.4  W [270 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE......-0.12
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.22  DEPARTURE......+0.23
                         ASOS..............1.27
TOTAL PRECIPITATION FOR THE YEAR..........22.03  DEPARTURE......+2.49
                         ASOS...............N/A ***
*** ASOS annual total not available due to erroneous readings


PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

5/1  50/43/47/-6/T/.../..                  21 N   AERO 18 N   RMY 22
5/2  65/42/54/+1/0.26/.../..               41 W   AERO 44 W   RMY 43               
5/3  52/42/53/0/0.00/.../..                37 WNW*AERO 39 WNW RMY 40
5/4  65/40/53/-1/0.00/.../..               23 S   AERO 23 S   RMY 24
5/5  51/44/48/-6/0.73/.../..               28 E   AERO 28 E   RMY N/A
5/6  65/50/58/+4/0.23/.../..               46 SSE AERO 48 SSE RMY 49
5/7  63/47/55/0/T/.../..                   35 S   AERO 38 S   RMY 39
5/8  54/38/46/-9/T/.../..                  29 WSW AERO 29 WSW RMY 32

5/9  Low temp since midnight is 36F; normal low is now 46F

DAILY RECORDS FOR MAY

None so far.

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):      

RECORDS FOR MAY 9
HIGH 93F IN 2000
LOW 31F IN 1947
PRECIP 2.72 INCHES IN 1954
SNOWFALL 5.0 INS IN 1977 (RECORD FOR MAY)
PEAK GUST 70e MPH NE IN 1977

RECORDS FOR MAY 10
HIGH 93F IN 1896
LOW 29F  IN 1900
PRE 1.85 INS IN 1998
SNOW 2.8 INS 1977 (7.8 INS TOTAL 5/9-5/10 1977)
PEAK GUST 64 MPH S IN 1990

TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle and Nicholas Rousseau