Saturday, October 20, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, OCTOBER 20, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

CLOUDY, WINDY DAY ON TOP OF GREAT BLUE HILL….

Overcast conditions persisted throughout the day until
1 P.M. when a small patch of the sky became visible. Winds
have consistently gusted over 25 knots, with a peak wind
speed so far today of 30 knots around 5:50 A.M. Low
pressure stayed in the area, with a station pressure of
only 28.99 inches of mercury at the 7:00 A.M. observation.
The high temperature so far is 62F, 2 degrees above our
normal high temperature for today of 59F. On this day in
1996, 7.10 inches of rain fell at Great Blue Hill, which
is the record for the month of October in precipitation. Our
low temperature since midnight is 51F, 10 degrees above our
normal low of 41F.

Today’s Observations:

7 A.M.
Weather: Overcast stratus, few cumulus in all directions
Temperature: 55F; Dew Point: 45F; Wind: SSW at 13G22 kts
Sea-level pressure: 29.69 ins. Hg, falling steadily
Visibility: 40 miles
6-hr Max temp: 55F
6-hr Min temp: 51F
24-hr Precip: 0.00 ins.
BHO SA 1155 E50 OVC 40 054/55/45/2113G22/969/ FEW CU ALQDS
DSNT HZ ALQDS/ 8/600 55014 10055 20051

10 A.M.
Weather: Overcast stratocumulus
Temperature: 57F; Dew Point: 47F; Wind: WSW at 16G27 kts
Peak Wind: 27 WSW at 9:58 A.M.
Sea-level pressure: 29.66 ins. Hg, steady then falling
Visibility: 70 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E21 OVC 70 045/57/47/2516G27/966/ PK WND 2527/58/
8/500 58009

1 P.M.
Weather: Broken stratocumulus, broken cirrocumulus
Temperature: 60F; Dew Point: 46F; Wind: W at 12G19 kts
Sea-level pressure: 29.60 ins. Hg, falling rapidly
Visibility: 80 miles
6-hr Max temp: 62F
6-hr Min temp: 55F
6-hr Precip: 0.00 ins.
BHO SA 1755 E50 BKN 250 BKN 80 025/60/46/2612G19/960/ 8/509
58020 10062 20055

SUMMARY FOR FRIDAY, OCTOBER 19, 2018

TEMPERATURE (DEGREES F)
MAX…..60   NORMAL…..59
MIN…..31   NORMAL…..42
MEAN….46   NORMAL…..50

DEPARTURE FROM 30-YEAR NORMAL…………………..-4
TOTAL DEPARTURE FOR THE MONTH………………….+32 [+1.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..19   DEPARTURE………+4
TOTAL HEATING UNITS FOR THE MONTH………….192   DEPARTURE……..-29
TOTAL HEATING UNITS FOR THE SEASON…………279   DEPARTURE……..-84
TOTAL HEATING UNITS LAST SEASON TO DATE…….191   DIFFERENCE…….+88

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0  DEPARTURE………..0
TOTAL COOLING UNITS FOR THE MONTH…………..11  DEPARTURE……….+6
TOTAL COOLING UNITS FOR THE SEASON…………874  DEPARTURE……..+272
TOTAL COOLING UNITS LAST SEASON TO DATE…….727  DIFFERENCE…….+147

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..33 SSW AT 10:24 P.M.
AERO…………………….35 SSW AT 10:25 P.M.
ASOS…………………….36 SSW AT 10:27 9.M.
DAVIS……………………33 SW  AT 10:28 P.M. RMY 36
FASTEST MILE FOR YESTERDAY………………….25 WSW AT  8:20 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….25 SSW AT 10:27 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………24 SW  AT  9:39 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..15.3 SW
ASOS…………………..14.8
DAVIS………………….15.1 SW [240 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……….2.76  DEPARTURE……-0.07
ASOS…………..2.76
TOTAL PRECIPITATION FOR THE YEAR……….49.96  DEPARTURE……+8.23
ASOS………….51.68

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

10/01 65/53/59/+2/…./042/06         21 ENE AERO 18 SSW RMY N/A
10/02 64/53/59/+2/…./000/00         33 S   AERO 32 S   RMY 35 TSTM
10/03 60/52/56/0/…./000/00          18 NNE AERO 14 NNE RMY 14
10/04 69/57/63/+7/…./209/30         29 SSW AERO 29 SSW RMY 32
10/05 64/47/56/0/…./638/92          25 NE  AERO 21 NE  RMY 24
10/06 64/45/55/0/0.00/276/40          23 SSW AERO 23 SSW RMY 25
10/07 75/56/66/+11/…./076/11        28 NE  AERO 24 ENE RMY 27
10/08 56/53/55/+1/…./000/00         22 ENE AERO 20 ENE RMY N/A
10/09 75/56/66/+12/…./211/31        26 WSW AERO 28 SW  RMY 29
10/10 82/65/74/+20/…./496/73        24 WSW AERO 23 WSW RMY 25
10/11 70/56/63/+10/…./…/..        48 NNE AERO 47 NNE RMY 50
10/12 59/44/52/-1/…./…/..         32 NW  AERO 32 NW  RMY 33
10/13 49/40/45/-8/…./…/..         21 WNW AERO 20 WNW RMY 20
10/14 55/37/46/-6/…./…/..         21 W   AERO 18 W   RMY 21
10/15 66/44/55/+3/…./…/..         46 W   AERO 46 W   RMY N/A
10/16 56/41/49/-2/…./…/..         48 W   AERO 48 W   RMY N/A
10/17 60/39/50/-1/…./…/..         48 W   AERO 50 W   RMY 53
10/18 45/33/39/-12/…./…/..        32 WNW AERO 35 WNW RMY 36
10/19 60/31/46/-4/…./…/..         33 SSW AERO 36 SSW RMY 36

10/20 Low temp since midnight is 51F; normal low is 41F

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: Samantha Richard