Sunday, September 25, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, SEPTEMBER 25, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

COLD START TO THE DAY BRINGS SEASONABLE TEMPERATURES TO
THE SUMMIT

The cold front that moved through New England on Friday
evening continues to bring the cold air down behind it.
The wind direction turned out of the northeast by late
afternoon on Friday and the winds continues to blow out of the
Northwest. The low temperature of 44F this morning was the
lowest reading of the season so far, with much cooler
temperatures expected the next couple of nights. As of
mid-afternoon, the dew point has dropped into the middle 30s.
The visibility today has been excellent near 75-80 miles.

7 A.M.
Weather: Few Cumulus distant E-SSE
Temperature: 47F; Dew Point: 49F; Wind: NW at 10 kts
Sea-level pressure: 30.14 ins. Hg, rising, then more rapidly
Visibility: 70 miles
6-hr Max temp: 47F
6-hr Min temp: 44F
24-hr precip: 0.00 in.
BHO SA 1155 CLR 70 207/47/35/3210/014/ FEW CU DSNT E-SSE/
8/1// 53010 10047 20044

10 A.M.
Weather: Few cumulus distant NNE-SSE
Temperature: 58F; Dew Point: 35F; Wind: NNW at 11G20 kts,
Sea-level pressure: 30.13 ins. Hg, steady then falling
Visibility: 75 miles
BHO SA 1455 CLR 75 204/58/35/3311G20/013/ FEW CU DSNT
NNW-SSE/ 8/1// 58003

1 P.M.
Weather: Few cumulus
Temperature: 64F; Dew Point: 31F; Wind: WNW at 13G26 kts
Sea-level pressure: 30.09 ins. Hg, falling, then more quickly
Visibility: 80 miles
6-hr Max. temp: 64F
6-hr Min. temp: 47F
6-hr precip: 0.00 in.
BHO SA 1755 CLR 80 189/64/31/3013G26/009/ FEW CU ALQDS/ 8/1//
58015 10064 20047

SUMMARY FOR SATURDAY, SEPTEMBER 24, 2016

TEMPERATURE (DEGREES F)
MAX…..66   NORMAL…..68
MIN…..48   NORMAL…..51
MEAN….57   NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL……………………-3
TOTAL DEPARTURE FOR THE MONTH………………….+104 [+4.4 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE……….-1
TOTAL COOLING UNITS FOR THE MONTH………….102   DEPARTURE………+47
TOTAL COOLING UNITS FOR THE SEASON…………894   DEPARTURE……..+302
TOTAL COOLING UNITS LAST SEASON TO DATE…….797   DIFFERENCE……..+97

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………8   DEPARTURE……….+2
TOTAL HEATING UNITS FOR THE MONTH…………..14   DEPARTURE………-60
TOTAL HEATING UNITS FOR THE SEASON………….24   DEPARTURE………-75
TOTAL HEATING UNITS LAST SEASON TO DATE……..22   DIFFERENCE………+2

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….24 NW  AT  2:30 P.M.
ASOS……………………25 NW  AT  3:47 P.M.
DAVIS…………………..23 WNW AT  2:06 P.M. RMY 25
FASTEST MILE FOR YESTERDAY…………………21 NW  AT  3:47 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………20 NW  AT  3:47 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..17 NW  AT  3:47 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..9.2 NW
ASOS…………………..9.2
DAVIS………………….7.7 NNW  [332 Deg.] * Last of several occurrences

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……….1.66  DEPARTURE……-1.51
ASOS…………..1.66
TOTAL PRECIPITATION FOR THE YEAR……….26.63  DEPARTURE…..-11.56
ASOS………….26.93

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 81/64/73/+12/T/…/..                   20 WNW AERO  M     RMY 18
9/22 82/63/73/+12/0.00/…/..                23 S   AERO  M     RMY 25
9/23 80/53/67/+7/…./…/..                 32 NE  AERO  M     RMY 32
9/24 66/48/57/-3/…./…/..                 24 NW  AERO  M     RMY 25

9/25 Low temp since midnight is 44F; normal low is now 51F

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 25
HIGH 87F IN 1970
LOW 31F IN 1950
PRECIP 2.68 INCHES IN 1961
PEAK GUST 63 MPH SSW IN 1991

RECORDS FOR SEPTEMBER 26
HIGH 91F IN 2007
LOW 36F IN 1905,1922,1978
PRECIP 3.84 INCHES IN 1888
PEAK GUST 54e MPH S IN 1977

TODAY’S REPORT PREPARED BY: Robert Millette