Sunday, September 16, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, SEPTEMBER 16, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

HAZY BUT FAIR SKY DAY ON TOP OF GREAT BLUE HILL…

Today started off with a layer of fog just above the horizon
in all directions. As the day progressed, the fog dissipated
into haze, which persisted through the 1 o’clock observation.
Wind was fairly light today, only rising over 10 knots once so
far. Pressure began to drop around 9:00 A.M., causing a slight
increase in clouds, but only enough to cover about 1/8th of
the sky. We have reached a high so far of 83F, which is 11
degrees above the normal high of 72F.

Today’s Observations:

7 A.M.
Weather: Clear, distant fog in all directions
Temperature: 66F; Dew Point: 64F; Wind: NW at 4 kts,
Wind: Light
Sea-level pressure: 30.22 ins. Hg, rising, then more slowly
Visibility: 80 miles
6-hr Max temp: 66F
6-hr Min temp: 61F
24-hr Precip: 0.00 ins.
BHO SA 1155 CLR 80 234/66/64/3204/022/ DSNT FG ALQDS WND LGT/
51009 10066 20061

10 A.M.
Weather: Few cumulus W-NW
Temperature: 78F; Dew Point: 67F; Wind: SW at 1 kts,
Wind: Light and variable, direction estimated
Sea-level pressure: 30.23 ins. Hg, rising then falling
Visibility: 80 miles, distant haze in all directions
BHO SA 1455 CLR 80 237/78/67/E1301/023/ FEW CU W-NW DSNT
HZ ALQDS WND L/V/ 8/100 50005

1 P.M.
Weather: Few cumulus in all directions
Temperature: 82F; Dew Point: 64F; Wind: ESE at 2 kts,
Wind: Light and variable, direction estimated
Sea-level pressure: 30.22 ins. Hg, falling, then more slowly
Visibility: 80 miles, distant haze in all directions
6-hr Max temp: 83F
6-hr Min temp: 66F
BHO SA 1755 CLR 80 232/82/64/E1102/022/ FEW CU ALQDS DSNT HZ
ALQDS WND L/V/ 8/100 57005 10083 20066

SUMMARY FOR SATURDAY, SEPTEMBER 15, 2018

TEMPERATURE (DEGREES F)
MAX…..76   NORMAL…..72
MIN…..62   NORMAL…..55
MEAN….69   NORMAL…..64

DEPARTURE FROM 30-YEAR NORMAL…………………..+5
TOTAL DEPARTURE FOR THE MONTH………………….+48 [+3.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-3
TOTAL HEATING UNITS FOR THE MONTH…………..18   DEPARTURE………-13
TOTAL HEATING UNITS FOR THE SEASON………….18   DEPARTURE………-38
TOTAL HEATING UNITS LAST SEASON TO DATE……..57   DIFFERENCE……..-39

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………4  DEPARTURE……….+2
TOTAL COOLING UNITS FOR THE MONTH…………..80  DEPARTURE………+37
TOTAL COOLING UNITS FOR THE SEASON…………833  DEPARTURE……..+253
TOTAL COOLING UNITS LAST SEASON TO DATE…….653  DIFFERENCE…….+180

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………………14 SW AT 10:02 P.M.
AERO……………………..13 SW AT 10:00 P.M.
ASOS……………………..14 SW AT 10:02 P.M.
DAVIS…………………….16 S  AT 10:01 P.M. RMY 13
FASTEST MILE FOR YESTERDAY…………………..11 SW AT 10:00 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………..12 SW AT 9:26  P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………….13 S  AT 10:02 P.M.
AVERAGE WIND SPEED AND DIRECTION…………….4.0 SW
ASOS…………………….4.2
DAVIS……………………4.6 SSE [DEG 153]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.95  DEPARTURE……+1.07
ASOS…………..2.95
TOTAL PRECIPITATION FOR THE YEAR……….40.90  DEPARTURE……+4.18
ASOS………….42.47

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

9/01 75/58/67/-1/0.00/521/66        17 NE  AERO 15 NE  RMY 16
9/02 83/61/72/+4/0.00/684/87        20 SSW AERO 18 SSW RMY N/A
9/03 92/68/80/+13/0.00/650/83       24 WSW AERO 22 WSW RMY 25
9/04 88/70/79/+12/0.00/695/89       17 W   AERO 16 W   RMY 17
9/05 89/67/78/+11/0.00/638/82       23 SSW AERO 23 SSW RMY 25
9/06 92/70/81/+14/0.56/488/63       29 NNW AERO 29 NNW RMY N/A TSTM
9/07 70/63/67/+1/0.01/000/00        24 NE  AERO 22 NE  RMY N/A
9/08 68/54/61/-5/0.00/031/04        22 NE  AERO 18 NE  RMY 21
9/09 61/53/57/-9/0.00/000/00        23 NE  AERO 21 NE  RMY N/A
9/10 62/56/59/-6/…./…/..        30 E   AERO 28 E   RMY 28
9/11 75/61/68/+3/…./…/..        23 E   AERO 21 E   RMY N/A TSTM
9/12 69/63/66/+1/…./…/..        21 ENE AERO 21 ENE RMY 21  TSTM
9/13 68/62/65/+1/…./…/..        21 NE  AERO 21 NE  RMY N/A TSTM
9/14 75/61/68/+4/…./…/..        13 NE  AERO 12 ENE RMY 12
9/15 76/62/69/+5/0.01/…/..        14 SW  AERO 13 SW  RMY 13

9/16 Low temp since midnight is 61F; normal low is now 55F

DAILY RECORDS FOR SEPTEMBER

09/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 70F,
BREAKS PREVIOUS RECORD OF 68F SET IN 1937 AND 1959

09/06/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 92F,
TIES PREVIOUS RECORD OF 92F SET IN 1900

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

RECORDS FOR SEPTEMBER 16
HIGH 91F IN 1939,1941
LOW 39F IN 1984
PRECIP 5.12 INCHES IN 1933 (Hurricane)
PEAK GUST 59 MPH SSE IN 1999

RECORDS FOR SEPTEMBER 17
HIGH 87F IN 2015
LOW 38F IN 1959
PRECIP 2.73 INCHES IN 1933
PEAK GUST 60 MPH WNW IN 1999

TODAY’S REPORT PREPARED BY: Samantha Richard