Tuesday, September 20, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, SEPTEMBER 20, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

MORNING FOG SLOWLY CLEARS, DRIER AIR PUSHING OUT TROPICAL MOISTURE

Yesterday’s passing cold front left us with 0.16 in. of precipitation for the day,
but tropical moisture was slow to leave the area.  The morning fog eventually
cleared to mostly sunny skies and 40 miles of visibility by the early afternoon.
Dew points remained in the upper 60s during each observation today even though
high pressure is set to bring in warmer temperatures and drier air.  Temperatures
had reached a max. of 78F by the 1:00PM observation, 8F above normal, continuing
the trend of above-normal temperatures for most of the month.

7 A.M.
Weather: Fog
Temperature: 67F; Dew Point: 67F; Wind: estimated WNW at 3 kts,
Wind Speed: Light
Sea-level pressure: 30.13 ins. Hg, rising, then more quickly
Visibility: 1/8 mile
6-hr Max temp: 67F
6-hr Min temp: 66F
24-hr precip: 0.16 in.
BHO SA 1155 W2 X 1/8F 202/67/67/E2903/013/ WND LGT/ 8//// 53009
MANUAL 70016 ASOS 70016 10067 20066

10 A.M.
Weather: Scattered stratus, broken altostratus
Temperature: 69F; Dew Point: 67F; Wind: estimated NNW at 1 kt,
Wind: Light and variable
Sea-level pressure: 30.15 ins. Hg, rising then falling
Visibility: 15 miles, distant fog
BHO SA 1455 6 SCT E200 BKN 15 209/69/67/E3301/015/ DSNT FG WND L/V/
8/610 51007

1 P.M.
Weather: Scattered cumulus, broken cirrus
Temperature: 78F; Dew Point: 66F; Wind: estimated W at 3 kts,
Wind: Light and variable
Sea-level pressure: 30.11 ins. Hg, falling, then more slowly
Visibility: 40 miles, except 20 miles NNE-NE, distant fog NNE-NE
6-hr Max. temp: 78F
6-hr Min. temp: 66F
6-hr precip: 0.00 in.
BHO SA 1755 29 SCT E200 BKN 40 195/78/66/E2703/011/ VSBY NNE-NE 20
DSNT FG NNE-NE WND L/V/ 8/102 56014 10078 20066

SUMMARY FOR MONDAY, SEPTEMBER 19, 2016

TEMPERATURE (DEGREES F)
MAX…..73   NORMAL…..71
MIN…..67   NORMAL…..54
MEAN….70   NORMAL…..62

DEPARTURE FROM 30-YEAR NORMAL……………………+8
TOTAL DEPARTURE FOR THE MONTH…………………..+56 [+2.7 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………5   DEPARTURE……….+4
TOTAL COOLING UNITS FOR THE MONTH…………..75   DEPARTURE………+26
TOTAL COOLING UNITS FOR THE SEASON…………867   DEPARTURE……..+281
TOTAL COOLING UNITS LAST SEASON TO DATE…….797   DIFFERENCE……..+70

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-4
TOTAL HEATING UNITS FOR THE MONTH……………6   DEPARTURE………-41
TOTAL HEATING UNITS FOR THE SEASON………….16   DEPARTURE………-56
TOTAL HEATING UNITS LAST SEASON TO DATE………6   DIFFERENCE……..+10

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….25 S   AT  2:13 A.M.
ASOS……………………27 S   AT  2:13 A.M.
DAVIS…………………..26 SSW AT  2:27 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………17 S   AT  2:27 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………17 SSW AT  2:33 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..17 S   AT  2:27 A.M.
AVERAGE WIND SPEED AND DIRECTION………….6.6 S
ASOS…………………..7.0
DAVIS………………….6.3 S [190 Deg.] * Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.16  DEPARTURE……+0.02
ASOS…………..0.16
TOTAL PRECIPITATION FOR THE MONTH……….1.47  DEPARTURE……-0.97
ASOS…………..1.47
TOTAL PRECIPITATION FOR THE YEAR……….26.44  DEPARTURE…..-11.02
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 81/57/69/0/0.00/739/98                  25 SSW AERO  M     RMY 26
9/14 87/58/73/+5/T/526/70                    35 NNW AERO  M     RMY 35
9/15 67/52/60/+9/0.00/531/71                 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 Low temp since midnight is 66F; 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 20
HIGH 90 IN 1983
LOW 34 IN 1979
PRECIP 4.57 INS IN 1899
PEAK GUST 44 MPH NE IN 1972

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)

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle