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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, OCTOBER 12, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME

MODERATE NORTHEAST WINDS BRING COOLER TEMPERATURES 

After over a week of above seasonable temperatures
it finally feels like autumn on top of Great Blue Hill.
We had a high temperature of 58F by 1:00 PM EST. This
is slightly below the normal of 62F for this day. This
is also an 18 degree decrease from Tuesday's high of 76F.

Winds were moderate and from the northeast, with a peak 
gust of 30 MPH by 1:00 PM EST. With low dew points and 
humidity we had excellent visibility with 70 miles in 
the morning and 80 miles at the 1:00 PM observation.   

Today's Observations:

7 A.M.
Weather: Scattered altocumulus, few cumulus NE-S
Temperature: 51F; Dew Point: 40F; Wind: NE at 11G22 kts
Sea-level pressure: 30.42 ins. Hg, rising, then more rapidly 
Visibility: 70 miles
6-hr Max temp: 55F
6-hr Min temp: 51F
24-hr precip: Trace
BHO SA 1155 90 SCT 70 301/51/40/0511G22/042/ FEW CU NE-S/ 8/160 
53022 10055 20051 

10 A.M.
Weather: Scattered cumulus, few cirrus N
Temperature: 55F; Dew Point: 39F; Wind: NE at 13G24 kts
Sea-level pressure: 30.45 ins. Hg, rising then falling
Visibility: 70 miles
BHO SA 1455 30 SCT 70 311/55/39/0513G24/045/ FEW CI N/ 8/101 

1 P.M. 
Weather: Scattered cumulus 
Temperature: 55F; Dew Point: 38F; Wind: NE at 11G20 kts
Sea-level pressure: 30.45 ins. Hg, steady
Visibility: 80 miles
6-hr Max temp: 58F 
6-hr Min temp: 51F
BHO SA 1755 38 SCT 80 311/55/38/0511G20/045/ 8/100 50000 10058 
20051 

SUMMARY FOR WEDNESDAY, OCTOBER 11, 2017
 
TEMPERATURE (DEGREES F)
MAX.....68   NORMAL.....62
MIN.....55   NORMAL.....45
MEAN....62   NORMAL.....53

DEPARTURE FROM 30-YEAR NORMAL.........................+9
TOTAL DEPARTURE FOR THE MONTH........................+97 [+8.6 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............0   DEPARTURE...........0
TOTAL COOLING UNITS FOR THE MONTH..............20   DEPARTURE.........+16
TOTAL COOLING UNITS FOR THE SEASON............727   DEPARTURE........+126
TOTAL COOLING UNITS LAST SEASON TO DATE.......894   DEPARTURE........-167

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............3   DEPARTURE..........-9
TOTAL HEATING UNITS FOR THE MONTH..............31   DEPARTURE.........-82
TOTAL HEATING UNITS FOR THE SEASON............124   DEPARTURE........-131
TOTAL HEATING UNITS LAST SEASON TO DATE.......174   DEPARTURE.........-50

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................29 ENE AT 11:42 P.M.
                   AERO........................25 ENE AT 11:43 P.M.
                   ASOS........................30 ENE AT 11:43 P.M.
                   DAVIS.......................28 ENE AT 11:43 P.M.   RMY 29
FASTEST MILE FOR YESTERDAY.....................21 ENE AT 11:41 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................20 ENE AT 11:43 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................20 ENE AT 11:42 P.M.
AVERAGE WIND SPEED AND DIRECTION..............9.8 ENE
                   ASOS......................10.4
                   DAVIS......................9.4 NE  [40 DEG.]


PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE......-0.15
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.45  DEPARTURE......-1.18
                         ASOS..............0.46
TOTAL PRECIPITATION FOR THE YEAR..........42.31  DEPARTURE......+1.60
                         ASOS...............N/A ***
*** ASOS annual total not available due to erroneous readings


PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 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

10/1  65/42/54/-3/0.00/697/99               18 WNW AERO 16 NW  RMY N/A
10/2  65/46/56/-1/0.00/687/98               21 NNW AERO 21 NNW RMY 21
10/3  67/50/59/+3/0.00/677/97               21 S   AERO 21 S   RMY N/A
10/4  75/50/63/+7/0.00/660/95               30 SSW AERO 30 SW  RMY 32
10/5  79/60/70/+14/0.00/.../..              28 SW  AERO 26 SW  RMY N/A
10/6  73/57/65/+10/T/.../..                 15 NW  AERO 14 NW  RMY 15
10/7  75/59/67/+12/T/.../..                 29 S   AERO 30 SSW RMY N/A
10/8  71/67/69/+15/0.23/.../..              33 S   AERO 36 SSW RMY 37
10/9  71/68/70/+16/0.22/.../..              43 S   AERO 41 S   RMY 45
10/10 76/61/69/+15/0.00/.../..              21 WNW AERO 20 WNW RMY 21 
10/11 68/55/62/+9/0.00/.../..               29 ENE AERO 25 ENE RMY 29 

10/12 Low temp since midnight is 51F; normal low is now 45F

DAILY RECORDS FOR OCTOBER

10/8/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
         BREAKS PREVIOUS RECORD OF 60F SET IN 1944

10/9/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 68F,
         BREAKS PREVIOUS RECORD OF 61F SET IN 2011

10/9/17: MONTHLY RECORD HIGH MINIMUM TEMPERATURE OF 68F,
         BREAKS PREVIOUS RECORD OF 67F SET ON OCTOBER 13, 1990
         AND TIED ON OCTOBER 8, 2017

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

RECORDS FOR OCTOBER 12
HIGH 87F IN 1954
LOW 31F IN 1906
PRECIP 1.53 INCHES IN 1948
SNOWFALL TRACE IN 1941
PEAK GUST 55 MPH NW IN 1963

RECORDS FOR OCTOBER 13
HIGH 84F IN 1930,1954
LOW 29F IN 2012
PRECIP 5.92 INCHES IN 1895
SNOWFALL 4.2 INCHES IN 1934
PEAK GUST 46e MPH W IN 1950

TODAY'S REPORT PREPARED BY: Kaitlin Geagan