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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 12, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME

SKIES CLEARED AFTER MORNING SHOWER

Light precipitation starting falling at the observatory around 6:45 AM EST.
The shower produced 0.01 inches of precipitation. The shower was finished
before the 10:00 AM EST observation. Skies were overcast stratus with poor
visibility SSW-ENE. Visibility increased as winds picked up and pressure rose 
and humidity dropped. Winds were mild and from the NE for most of the day 
today. Temperatures reached a maximum of 56F by 1:00 PM EST which is almost 
10 degrees below normal.   

Today's Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 46F; Dew Point: 46F; Wind: N at 7 kts
Sea-level pressure: 30.09 ins. Hg, rising then more slowly
Visibility: 5 miles except 20 ENE-SSW
6-hr Max temp: 46F
6-hr Min temp: 42F
24-hr precip: Trace
BHO SA 1155 E10 OVC 5L-F 188/46/46/3607/009/ VSBY ENE-SSW 20 
DSNT FG ENE-SSW PCPN VRY LGT 8/6// 51016 MANUAL 700// 10046 20042

10 A.M.
Weather: Broken stratocumulus
Temperature: 52F; Dew Point: 45F; Wind: NE at 10G16 kts
Sea-level pressure: 30.09 ins. Hg, rising then falling
Visibility: 40 miles
BHO SA 1455 E11 BKN 40 191/52/45/0510G16/009/ 8/4// 50003 MANUAL 
6001/ ASOS 60001

1 P.M.
Weather: Broken stratocumulus
Temperature: 55F; Dew Point: 44F; Wind: NE at 8 kts
Sea-level pressure: 30.08 ins. Hg, rising then falling
Visibility: 70 miles
6-hr Max temp: 56F
6-hr Min temp: 51F
BHO SA 1755 E26 BKN 70 187/55/44/0508/008/ 8/4// 58004 10056 20051 


SUMMARY FOR THURSDAY, MAY 11, 2017
 
TEMPERATURE (DEGREES F)
MAX.....58   NORMAL.....65
MIN.....45   NORMAL.....46
MEAN....52   NORMAL.....56

DEPARTURE FROM 30-YEAR NORMAL.........................-4
TOTAL DEPARTURE FOR THE MONTH........................-36 [-3.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............13   DEPARTURE..........+4
TOTAL HEATING UNITS FOR THE MONTH.............154   DEPARTURE.........+31
TOTAL HEATING UNITS FOR THE SEASON...........5487   DEPARTURE........-671
TOTAL HEATING UNITS LAST SEASON TO DATE......5160   DIFFERENCE.......+327

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................23 NE  AT  2:57 P.M.
                   AERO........................23 NE  AT  8:55 A.M.
                   ASOS........................25 E   AT  8:56 A.M.
                   DAVIS.......................22 ENE AT  8:55 A.M. RMY 23
FASTEST MILE FOR YESTERDAY.....................15 NE  AT  8:55 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................17 E   AT  9:27 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................15 ENE AT  9:27 A.M.
AVERAGE WIND SPEED AND DIRECTION..............8.4 NE
                   ASOS.......................9.3
                   DAVIS......................7.3 NE [47 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......-0.12
                         ASOS..............1.27
TOTAL PRECIPITATION FOR THE YEAR..........22.03  DEPARTURE......+2.14
                         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  53/36/45/-10/T/.../..                 20 ESE AERO 17 ESE RMY 19
5/10 57/42/50/-5/0.00/.../..               17 NNE AERO 16 NW  RMY N/A
5/11 58/45/52/-4/0.00/.../..               23 NE* AERO 23 NE  RMY 23 

5/11 Low temp since midnight is 41F; 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 12
HIGH 88F IN 2001
LOW 29F IN 1907
PRECIP 1.49 INCHES IN 1968
PEAK GUST 76 MPH S IN 1974

RECORDS FOR MAY 13
HIGH 85F IN 1947
LOW 35F IN 1914, 2005
PRECIP 2.39 INCHES IN 2006
PEAK GUST 49 MPH NNW IN 1965

TODAY'S REPORT PREPARED BY: Kaitlin Ann Geagan