Wednesday, October 18, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, OCTOBER 18, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

WITH HIGH PRESSURE DRY AND CLEAR CONDITIONS CONTINUE

With high pressure in the area we had a clear dry day
with a few distant cirrus clouds at each observation.
Humidity was low all day with a drop from 68% at
7:00 AM EST to 35% by 1:00 PM EST. Visibility
increased from 60 miles at 7:00 AM EST to 70 miles
at 10:00 AM EST and 1:00 PM EST. Temperatures have
increased with an overnight wind direction change from
NW to SW. We have had a high of 69F by 1:00 PM EST.
This is 9 degrees above the normal of 60F.
Winds became light and shifted to WNW after the
7:00 AM observation.

Today’s Observations:

7 A.M.
Weather: Clear, few distant cirrus ENE-SSE AND WSW-WNW
Temperature: 46F; Dew Point: 36F; Wind: WSW at 11 kts
Sea-level pressure: 30.25 ins. Hg, rising, then more quickly
Visibility: 60 miles
6-hr Max temp: 47F
6-hr Min temp: 45F
24-hr precip: 0.00 ins.
BHO SA 1155 CLR 60 245/46/36/2511/025/ FEW DSNT CI ENE-SSE
AND WSW-WNW/ 8/005 53007 10047 20045

10 A.M.
Weather: Clear, few distant cirrostratus all directions,
few distant cirrus WSW-W
Temperature: 61F; Dew Point: 44F; Wind: W at 6 kts,
Wind: Light
Sea-level pressure: 30.29 ins. Hg, rising, then more slowly
Visibility: 70 miles
BHO SA 1455 CLR 70 257/61/44/2606/029/ FEW DSNT CS ALQDS
FEW DSNT CI WSW-W WND LGT/ 8/005 51012

1 P.M.
Weather: Clear, few distant cirrus SE and NE
Temperature: 68F; Dew Point: 40F; Wind: WNW at 6 kts,
Wind: Light
Sea-level pressure: 30.25 ins. Hg, falling, then more quickly
Visibility: 70 miles
6-hr Max temp: 69F
6-hr Min temp: 47F
BHO SA 1755 CLR 70 243/68/40/2906/025/ FEW DSNT CI SE-NE
WND LGT/ 8/001 58014 10069 20047

SUMMARY FOR TUESDAY, OCTOBER 17, 2017

TEMPERATURE (DEGREES F)
MAX…..57   NORMAL…..60
MIN…..35   NORMAL…..42
MEAN….46   NORMAL…..51

DEPARTURE FROM 30-YEAR NORMAL…………………….-5
TOTAL DEPARTURE FOR THE MONTH…………………..+118 [+6.7 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…………..19   DEPARTURE……….-2
TOTAL HEATING UNITS FOR THE MONTH…………..88   DEPARTURE……..-104
TOTAL HEATING UNITS FOR THE SEASON…………181   DEPARTURE……..-153
TOTAL HEATING UNITS LAST SEASON TO DATE…….223   DEPARTURE………-42

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….25  S   AT   5:57 P.M.
AERO……………………22  S   AT   5:57 P.M.
ASOS……………………25  S   AT   5:58 P.M.
DAVIS…………………..25  SSW AT   5:57 P.M.   RMY 25
FASTEST MILE FOR YESTERDAY…………………20  SW  AT  11:11 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………20  SSW AT  11:12 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..18  SW  AT  11:11 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..9.8  NNW
ASOS…………………..9.9
DAVIS………………….9.4  W  [272 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……-2.02
ASOS…………..0.50
TOTAL PRECIPITATION FOR THE YEAR……….42.36  DEPARTURE……+0.76
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/…/..              28 SW  AERO 26 SW  RMY N/A
10/6  73/57/65/+10/T/…/..                 15 NW  AERO 14 NW  RMY 15
10/7  75/59/67/+12/T/…/..                 29 S   AERO 30 SSW RMY N/A
10/8  71/67/69/+15/0.23/…/..              33 S   AERO 36 SSW RMY 37
10/9  71/68/70/+16/0.22/…/..              43 S   AERO 41 S   RMY 45
10/10 76/61/69/+15/0.00/…/..              21 WNW AERO 20 WNW RMY 21
10/11 68/55/62/+9/0.00/…/..               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 Low temp since midnight is 45F; 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 18
HIGH 82F IN 1908
LOW  26F IN 1939
PRECIP 2.79 INCHES IN 1975
SNOWFALL 3.0 INCHES IN 2009
PEAK GUST 66 MPH S IN 1967

RECORDS FOR OCTOBER 19
HIGH 81F IN 1945
LOW  21F IN 1922
PRECIP 3.64 INCHES IN 1932
SNOWFALL 1.0 INCHES IN 1972
PEAK GUST 66 MPH SSW IN 1967

TODAY’S REPORT PREPARED BY: Kaitlin Geagan/Afshin Pourmokhtarian