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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 21, 2016  
ALL TIMES ARE IN EASTERN STANDARD TIME

HIGH PRESSURE AND DRY AIR MOVE INTO REGION

High pressure over the region has given us a very pleasant last day of summer.
Temperatures climbed to a max. of 80F by the 1:00PM observation, and dew points
dropped to the mid 40s in the early afternoon.  Visibility remained at 70 miles
all day with winds out of the NW.  An early morning shower left us with a trace
of precipitation by the 7AM EST observation.


7 A.M. 
Weather: Broken cirrus
Temperature: 66F; Dew Point: 60F; Wind: NW at 10 kts
Sea-level pressure: 30.15 ins. Hg, rising unsteadily 
Visibility: 70 miles
6-hr Max temp: 68F
6-hr Min temp: 64F
24-hr precip: Trace
BHO SA 1155 E250 BKN 70 210/66/60/3110/015/ 8/002 52012 10068 20064

10 A.M.
Weather: Broken cirrostratus 
Temperature: 74F; Dew Point: 52F; Wind: NW at 8 kts
Sea-level pressure: 30.17 ins. Hg, rising then steady
Visibility: 70 miles
BHO SA 1455 E250 BKN 70 218/74/52/3108/017/ 8/007 50008 

1 P.M. 
Weather: Broken cirrostratus
Temperature: 80F; Dew Point: 46F; Wind: WNW at 7 kts
Sea-level pressure: 30.16 ins. Hg, falling, then more quickly
Visibility: 70 miles
6-hr Max. temp: 80F 
6-hr Min. temp: 65F
6-hr precip: 0.00 in.
BHO SA 1755 E250 BKN 70 212/80/46/3007/016/ 8/006 58006 10080 20065

SUMMARY FOR TUESDAY, SEPTEMBER 20, 2016
 
TEMPERATURE (DEGREES F)
MAX.....81   NORMAL.....70
MIN.....66   NORMAL.....53 
MEAN....74   NORMAL.....62

DEPARTURE FROM 30-YEAR NORMAL.......................+12
TOTAL DEPARTURE FOR THE MONTH.......................+76 [+3.6 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............9   DEPARTURE..........+8
TOTAL COOLING UNITS FOR THE MONTH..............84   DEPARTURE.........+33
TOTAL COOLING UNITS FOR THE SEASON............876   DEPARTURE........+288
TOTAL COOLING UNITS LAST SEASON TO DATE.......797   DIFFERENCE........+79 

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE..........-5
TOTAL HEATING UNITS FOR THE MONTH...............6   DEPARTURE.........-46
TOTAL HEATING UNITS FOR THE SEASON.............16   DEPARTURE.........-61
TOTAL HEATING UNITS LAST SEASON TO DATE.........6   DIFFERENCE........+10

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................16 WSW AT 10:51 P.M.*
                   ASOS........................16 WSW AT 11:14 P.M.  
                   DAVIS.......................15 SSW AT  8:46 P.M. RMY N/A 
FASTEST MILE FOR YESTERDAY.....................12 WSW AT 10:52 P.M.     
MAXIMUM 2-MINUTE ASOS AVERAGE..................13 W   AT 11:10 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE.................12 WSW AT 11:10 P.M.  
 AVERAGE WIND SPEED AND DIRECTION.............6.1 S  
                   ASOS.......................6.7
                   DAVIS......................5.7 SW [230 Deg.]
* Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace  DEPARTURE......-0.14
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.47  DEPARTURE......-1.11
                         ASOS..............1.47
TOTAL PRECIPITATION FOR THE YEAR..........26.44  DEPARTURE.....-11.16
                         ASOS.............26.74 
 
PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 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

9/1  72/64/68/0/0.09/000/00                  21 NNW AERO 16 NNW RMY 20
9/2  76/58/67/-1/0.00/738/94                 23 ENE AERO 17 NE  RMY 23
9/3  72/56/64/-3/0.00/368/47                 16 E   AERO 12 E   RMY N/A
9/4  71/58/65/-2/0.00/740/95                 28 NE  AERO 21 NE  RMY 27
9/5  73/57/65/-2/0.52/241/31                 42 NNE AER0 33 NNE RMY 43  
9/6  70/61/66/-1/0.54/046/06                 32 N   AERO 23 NNE RMY N/A  
9/7  78/66/72/+6/0.05/339/44                 21 NE* AERO 15 NE* RMY 21
9/8  79/65/72/+6/T/276/36                    22 S   AERO 15 S   RMY 23
9/9  90/69/80/+14/T/421/55                   23 W   AERO 24 W   RMY 25  
9/10 82/71/77/+12/T/229/30                   25 S   AERO 18 S   RMY 32
9/11 79/59/69/+4/0.10/365/48                 39 WNW AERO 30 WNW RMY 43
9/12 76/53/65/0/0.00/749/99                  18 SW* AERO 13 WNW RMY 19
9/13 81/57/69/+5/0.00/739/98                 25 SSW AERO  M     RMY 26
9/14 87/58/73/+9/T/526/70                    35 NNW AERO  M     RMY 35
9/15 67/52/60/-4/0.00/531/71                 21 NE  AERO  M     RMY 20
9/16 74/54/64/+1/0.00/567/76                 23 SSE AERO  M     RMY 24   
9/17 77/54/66/+3/0.00/.../..                 28 S   AERO  M     RMY 28
9/18 79/63/71/+9/T/.../..                    30 SW  AERO  M     RMY 33
9/19 73/67/70/+8/0.16/.../..                 25 S   AERO  M     RMY N/A
9/20 81/66/74/+12/0.00/.../..                16 WSW*AERO  M     RMY N/A

9/21 Low temp since midnight is 64F; normal low is now 53F

DAILY RECORDS FOR SEPTEMBER 2016

9/10/16: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 71F,
         BREAKS PREVIOUS RECORD OF 69F SET IN 1915, 1931, AND 1989

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

RECORDS FOR SEPTEMBER 21
HIGH 91 IN 1895
LOW 35 IN 1929, 1956, 1962
PRECIP 5.58 INS IN 1961 (HURRICANE ESTHER; RETURNED AS TS SEPT 25-26TH)
PEAK GUST 186 MPH S IN 1938 (GREAT NEW ENGLAND HURRICANE; CALCULATED GUST,
          STATION RECORD)

RECORDS FOR SEPTEMBER 22
HIGH 90F IN 1895, 1914
LOW 30F IN 1904 (Earliest freeze)
PRECIP 1.16 INCHES IN 2001
PEAK GUST 60 MPH SSW IN 1989

TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle