Friday, August 18, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, AUGUST 18, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

OVERCAST AND MODERATELY WINDY DAY

The skies remained overcast with stratus clouds all day. Winds
coming from the south-southeast began to pick up early this
morning, and we have had a peak gust of 33 MPH by the 1:00 PM
observation. Pressure has been falling throughout the day with
the anticipation of evening rainstorms. Humidity remained high
all day leaving sticky air on top of Great Blue Hill.

Looking back at the historical records, back in 1955 on this
date 5.75 inches of rain fell due to Tropical Storm Diane,
which was followed by another 7.02 inches the next day.
The total of 12.77 inches remains the highest two-day rainfall
amount on record at Blue Hill.

Today’s Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 68F; Dew Point: 63F; Wind: SSE at 12G18 kts
Sea-level pressure: 29.98 ins. Hg, rising, then falling
Visibility: 30 miles
6-hr Max temp: 67F
6-hr Min temp: 64F
24-hr precip: 0.00 in.
BHO SA 1155 E60 OVC 30 151/68/63/1612G18/998/ DSNT FG ALQDS/
8/6// 50001 10067 20064

10 A.M.
Weather: Overcast stratus
Temperature: 75F; Dew Point: 68F; Wind: SSE at 13G21 kts
Sea-level pressure: 29.93 ins. Hg, falling, then more quickly
Visibility: 15 miles
BHO SA 1455 E110 OVC 15 136/75/68/1613G21/993/ DSNT FG ALQDS/
8/6// 56015

1 P.M.
Weather: Overcast stratus fractus
Temperature: 76F; Dew Point: 69F; Wind: S at 16G27 kts,
Sea-level pressure: 29.90 ins. Hg, falling, then more quickly
Visibility: 30 miles
6-hr Max temp: 79F
6-hr Min temp: 71F
BHO SA 1755 E90 OVC 30 124/76/69/1916G27/990/ DSNT FG ALQDS PK
WND 1927/57/ 8/7// 58012 10079 20071

SUMMARY FOR THURSDAY, AUGUST 17, 2017

TEMPERATURE (DEGREES F)
MAX…..81   NORMAL…..79
MIN…..58   NORMAL…..62
MEAN….70   NORMAL…..71

DEPARTURE FROM 30-YEAR NORMAL…………………….-1
TOTAL DEPARTURE FOR THE MONTH…………………….+9 [+0.3 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………5   DEPARTURE……….-1
TOTAL COOLING UNITS FOR THE MONTH………….114   DEPARTURE……….+4
TOTAL COOLING UNITS FOR THE SEASON…………540   DEPARTURE………+74
TOTAL COOLING UNITS LAST SEASON TO DATE…….658   DEPARTURE……..-118

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….15 SSW AT  2:00 A.M.
AERO……………………14 SSW AT  1:28 A.M.
ASOS……………………18 N   AT  2:01 A.M.
DAVIS…………………..15 NW  AT  1:27 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………12 SSW AT  1:50 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………11 N   AT  1:56 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..13 N   AT  1:54 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..7.4 NNW
ASOS…………………..7.7
DAVIS………………….6.2 W   [279 DEG.] *last of multiple occurrences

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……….1.39  DEPARTURE……-0.97
ASOS…………..1.38
TOTAL PRECIPITATION FOR THE YEAR……….36.15  DEPARTURE……+2.80
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings

PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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

8/1  87/65/76/+4/0.00/762/88               16 ESE*AERO 16 NNW RMY 16
8/2  86/65/76/+4/1.09/372/43               32 W   AERO 36 W   RMY 34 TSTM
8/3  83/65/74/+2/0.00/552/64               22 S   AERO 23 S   RMY 24
8/4  84/66/75/+3/0.00/697/81               26 S   AERO 30 S   RMY 29
8/5  75/63/69/-3/0.10/060/07               23 NW  AERO 28 NW  RMY 29
8/6  76/57/67/-5/0.00/795/93               30 NW  AERO 32 NW  RMY 31
8/7  76/60/68/-4/0.01/597/70               28 SSW AERO 28 SSW RMY 29
8/8  74/60/67/-5/0.02/000/00               17 S   AERO 16 SSE RMY 16
8/9  83/58/71/-1/0.00/…/..               18 S   AERO 18 S   RMY 19
8/10 86/63/75/+4/T/…/..                  20 S   AERO 18 S   RMY 20
8/11 82/63/73/+2/0.00/…/..               17 S   AERO 16 S   RMY 17
8/12 75/57/66/-5/0.17/…/..               22 SSW*AERO 22 SSW RMY 23
8/13 84/67/76/+5/0.00/…/..               26 WNW AERO 24 WNW RMY 26
8/14 82/67/75/+4/0.00/…/..               14 SSW*AERO 14 S   RMY 15
8/15 79/64/72/+1/T/…/..                  21 S   AERO 21 S   RMY 23
8/16 83/64/74/+3/0.00/…/..               23 NW* AERO 23 NW  RMY 25
8/17 81/58/70/-1/0.00/…/..               15 SSW AERO 14 SSW RMY N/A

8/18 Low temp since midnight is 63F; normal low is now 62F

DAILY RECORDS FOR AUGUST

None so far.

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

RECORDS FOR AUGUST 18
HIGH 93F IN 2002
LOW 47F IN 1824
PRECIP 5.75 INCHES IN 1955 [DIANE] PEAK GUST 46 MPH WNW IN 2007

RECORDS FOR AUGUST 19
HIGH 90F IN 1906, 1966, 2002
LOW 48F IN 1958
PRECIP 7.02 INCHES IN 1955 [DIANE – RECORD FOR MONTH] PEAK GUST 78 MPH ENE IN 1991 – HURRICANE BOB

TODAY’S REPORT PREPARED BY: Kaitlin Geagan