Friday, October 20, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, OCTOBER 20, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

SOUTHWEST WINDS CONTINUE TO BRING DRY WARM
AIR TO GREAT BLUE HILL

With high pressure stalling in the area, clear
and dry conditions continue. Sky remained mostly
clear with a few cirrus clouds at each observation.
The air is drier compared to yesterday, which
made the visibility today near perfect at 80 miles
at 10:00 AM EST and 1:00 PM EST. A distant fog
which left the area before 10:00 AM EST kept
visibility down to 70 miles at the 7:00 AM EST
observation.
With winds coming from the southwest temperatures
continue to be above seasonable with a high of 67F
by 1:00 PM EST this is 8 degrees above the normal
of 59F for this day. Winds from the SSW have been
light to moderate with gust up to 20 kts (23 MPH.)

Today’s Observations:

7 A.M.
Weather: Clear, few cirrus in all directions
Temperature: 55F; Dew Point: 44F; Wind: W at 12 kts
Sea-level pressure: 30.06ins. Hg, rising, then more quickly
Visibility: 70 miles distant fog in all directions
6-hr Max temp: 55F
6-hr Min temp: 53F
24-hr precip: 0.00 ins.
BHO SA 1155 CLR 70 179/55/44/2812/006/ FEW CI ALQDS
DSNT FG ALQDS/ 8/001 53015 10055 20053

10 A.M.
Weather: Few cirrus SSE
Temperature: 61F; Dew Point: 40F; Wind: NW at 10 kts
Sea-level pressure: 30.08 ins. Hg, rising then falling
Visibility: 80 miles
BHO SA 1455 CLR 80 185/61/40/3110/008/ FEW CI SSE/
8/001 50006

1 P.M.
Weather: Clear, few cirrus SSE-S
Temperature: 66F; Dew Point: 39F; Wind: WNW at 12G18 kts
Sea-level pressure: 30.02 ins. Hg, falling, then more slowly
Visibility: 80 miles
6-hr Max temp: 67F
6-hr Min temp: 55F
BHO SA 1755 CLR 80 167/66/39/3012G18/002/ FEW CI SSE-S/
8/001 58018 10067 20055

SUMMARY FOR THURSDAY, OCTOBER 19, 2017

TEMPERATURE (DEGREES F)
MAX…..72   NORMAL…..59
MIN…..52   NORMAL…..42
MEAN….62   NORMAL…..50

DEPARTURE FROM 30-YEAR NORMAL……………………+12
TOTAL DEPARTURE FOR THE MONTH…………………..+137 [+7.0 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………-12
TOTAL HEATING UNITS FOR THE MONTH…………..98   DEPARTURE……..-123
TOTAL HEATING UNITS FOR THE SEASON…………191   DEPARTURE……..-172
TOTAL HEATING UNITS LAST SEASON TO DATE…….223   DEPARTURE………-32

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….31  SSW  AT 3:27 P.M.
AERO……………………30  SSW  AT 3:25 P.M.
ASOS……………………34  SSW  AT 3:26 P.M.
DAVIS…………………..33  SSW  AT 2:53 P.M.  RMY 32
FASTEST MILE FOR YESTERDAY…………………25  SSW  AT 3:24 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………24  SSW  AT 7:33 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..25  SSW  AT 3:25 P.M.
AVERAGE WIND SPEED AND DIRECTION………….15.1  SSW
ASOS………………….15.1
DAVIS…………………14.6  SW  [216 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……….0.50  DEPARTURE……-2.33
ASOS…………..0.50
TOTAL PRECIPITATION FOR THE YEAR……….42.36  DEPARTURE……+0.45
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/+14/0.00/429/62          28 SW  AERO 26 SW  RMY N/A
10/6  73/57/65/+10/T/352/51             15 NW  AERO 14 NW  RMY 15
10/7  75/59/67/+12/T/344/50             29 S   AERO 30 SSW RMY N/A
10/8  71/67/69/+15/0.23/007/01          33 S   AERO 36 SSW RMY 37
10/9  71/68/70/+16/0.22/000/00          43 S   AERO 41 S   RMY 45
10/10 76/61/69/+15/0.00/637/94          21 WNW AERO 20 WNW RMY 21
10/11 68/55/62/+9/0.00/122/18           29 ENE AERO 25 ENE RMY 29
10/12 58/48/50/0/T/…/..               30 NE  AERO 28 ENE RMY 30
10/13 64/48/56/+3/0.00/…/..           20 E   AERO 16 E   RMY 17
10/14 66/54/60/+8/…/…/..            15 SSE AERO 13 SSE RMY 13
10/15 72/58/65/+13/…/…/..           39 SSW AERO 36 SSW RMY 40
10/16 66/39/53/+2/…/…/..            28 NNW AERO 25 NNW RMY 29
10/17 57/35/46/-5/0.00/…/..           25 S   AERO 22 S   RMY 25
10/18 70/45/58/+7/0.00/../..            25 SW  AERO 23 SW  RMY 22
10/19 72/52/62/+12/0.00/../..           31 SSW AERO 30 SSW RMY 32

10/20 Low temp since midnight is 53F; normal low is now 42F

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 20
HIGH 78F IN 1965,1984
LOW 24F IN 1972
PRECIP 7.10 INCHES IN 1996 (RECORD FOR MONTH)
SNOWFALL TRACE IN 1934,1943
PEAK GUST 63 MPH W IN 1966

RECORDS FOR OCTOBER 21
HIGH 79F IN 1979
LOW 24F IN 1974
PRECIP 2.39 INCHES IN 1944
SNOWFALL TRACE IN 1895,1907,1940
PEAK GUST 69e MPH S IN 1976

TODAY’S REPORT PREPARED BY: Kaitlin Geagan