Wednesday, October 21, 2020

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

WEDNESDAY, OCTOBER 21, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

MORNING FOG LED TO MOSTLY SUNNY CONDITIONS
IN THE AFTERNOON….

We observed foggy conditions from this morning until
the 1 P.M. observation. This quickly changed as skies
are mostly clear, and the sun had broken through shortly
after the usual observing hours. Visibility was limited
to 3 miles, but we are now seeing over 40 miles.

There was some rainfall overnight and this morning,
leaving only 0.06 inches in total. This doesn’t do
much for our annual deficit of almost three and a
half inches, but the month is still looking good
at a 1.20 inch surplus.

The high so far today is 64F, 5 degrees above the daily
normal minimum of 59F. The low since midnight is 56F,
15 degrees above the normal low of 41F.

Today’s Observations:

7 A.M.
Weather: Drizzle and fog
Temperature: 56F; Dew Point: 56F; Relative Humidity: 100%
Wind: S at 14 kts
Sea-level pressure: 30.33 ins. Hg: rising, then more slowly
Visibility: 1/16th mile, fog
6-hr Max temp: 59F
6-hr Min temp: 56F
24-hr Precip: 0.04 ins.
BHO SA 1155 X W3 1/16LF 270/56/56/0814/033/ LCTD/ 8//// 70004
53009 10059 20056

10 A.M.
Weather: Fog
Temperature: 58F; Dew Point: 58F; Relative Humidity: 100%
Wind: Calm
Sea-level pressure: 30.33 ins. Hg: falling steadily
Visibility: 1/16 mile, fog
3-hr Precip: 0.02 ins.
BHO SA 1455 X W3 1/16F 271/58/58/0000/033/ WND CALM/ 8////
6002/ 58001

1 P.M.
Weather: Broken stratus fractus, overcast altostratus
Temperature: 63F; Dew Point: 63F; Relative Humidity: 100%
Wind: WSW at 4 kts, light and variable
Sea-level pressure: 30.28 ins. Hg: falling steadily
Visibility: 3 miles, fog
6-hr Max temp: 64F
6-hr Min temp: 56F
6-hr Precip: 0.02 inches
BHO SA 1755 15 BKN 65 OVC 3F 254/63/63/2404/028/ WND L/V/
8/72/ 6002/ 58017 10064 20056

SUMMARY FOR TUESDAY, OCTOBER 20, 2020

TEMPERATURE (DEGREES F)
MAX…..66   NORMAL…..59
MIN…..49   NORMAL…..41
MEAN….58   NORMAL…..50

DEPARTURE FROM 30-YEAR NORMAL……………..+8
TOTAL DEPARTURE FOR THE MONTH…………….+54 [+2.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………. 7  DEPARTURE….. -8
TOTAL HEATING UNITS FOR THE MONTH…………177  DEPARTURE…..-59
TOTAL HEATING UNITS FOR THE SEASON………..275  DEPARTURE….-103
TOTAL HEATING UNITS LAST SEASON TO DATE……323  DEPARTURE…..-48

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………. 0  DEPARTURE…… 0
TOTAL COOLING UNITS FOR THE MONTH…………. 1  DEPARTURE….. -4
TOTAL COOLING UNITS FOR THE SEASON………..831  DEPARTURE….+229
TOTAL COOLING UNITS LAST SEASON TO DATE……682  DEPARTURE….+149

PEAK WIND GUST FOR YESTERDAY (MPH)
420C/Official……………22 S   AT  11:48 A.M.
AEROVANE (south tower)……22 S   AT   9:10 A.M.
ASOS……………………23 S   AT  11:50 A.M.
DAVIS #1………………..23 WSW AT  11:13 A.M.
DAVIS #2 (south tower)……27 SSE AT   9:13 A.M.
RMY…………………….22
MERLIN………………….22
FASTEST MILE FOR YESTERDAY…………………17 S   AT  11:56 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………16 S   AT  11:53 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…………..15 S   AT   6:38 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE…………..19 S   AT   9:11 A.M.
AVERAGE WIND SPEED AND DIRECTION………….8.2 S  [199 total miles] ASOS………………….9.2
DAVIS #1………………8.5 S    [190 deg.] DAVIS #2………………9.9 S    [182 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.04  DEPARTURE….-0.11
ASOS…………..0.03
TOTAL PRECIPITATION FOR THE MONTH……….4.18  DEPARTURE….+1.20
ASOS…………..4.16
TOTAL PRECIPITATION FOR THE YEAR……….38.60  DEPARTURE….-3.46
ASOS………….39.37

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  75/56/66/+9/0.00/…/..             28 SW   AERO 28 SW   RMY N/A
10/02  63/49/56/-1/0.02/…/..             20 NW   AERO 21 NW   RMY 20
10/03  65/45/55/-1/0.00/…/..             19 WNW  AERO 19 WNW  RMY 19
10/04  65/45/55/-1/0.00/…/..             17 ESE  AERO 18 ESE  RMY 18
10/05  62/52/57/+1/0.00/…/..             17 ENE  AERO 17 ENE  RMY N/A
10/06  69/51/60/+5/0.00/…/..             28 S    AERO 28 S    RMY 29
10/07  73/50/62/+7/0.14/…/..             76 W    AERO 74 W    RMY 70  TSTM
10/08  61/42/52/-2/0.00/…/..             41 W    AERO 41 W    RMY N/A
10/09  60/37/49/-5/0.00/…/..             25 SSW  AERO 28 SSW  RMY N/A
10/10  75/52/64/+10/0.00/…/..            40 SSW  AERO 40 SSW  RMY 38
10/11  64/47/56/+3/0.00/…/..             32 NNW  AERO 35 NNW  RMY N/A
10/12  52/48/50/-3/T/…/..                28 E    AERO 27 E    RMY N/A
10/13  57/49/53/0/1.74/…/..              32 E    AERO 33 E    RMY N/A
10/14  67/47/57/+5/0.00/…/..             23 WNW  AERO 25 WNW  RMY N/A
10/15  71/50/61/+9/0.00/…/..             43 S    AERO 46 S    RMY 42
10/16  68/48/58/+7/…./…/..             28 S    AERO 30 S    RMY N/A
10/17  56/39/48/-3/…./…/..             35 WNW  AERO 40 WNW  RMY 37
10/18  60/46/53/+2/0.00/…/..             20 ESE  AERO 21 ESE  RMY 20
10/19  61/46/54/+4/0.00/…/..             16 ESE  AERO 16 SSE  RMY N/A
10/20  66/49/58/+8/0.00/…/..             22 S    AERO 22 S    RMY 22

10/21 The low since midnight is 56F, the daily normal low is 41F

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

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

RECORDS FOR OCTOBER 22
HIGH 85F IN 1979
LOW 22F IN 1940
PRECIP 2.38 INCHES IN 2014
SNOWFALL TRACE IN 1969, 2010
PEAK GUST 67 MPH ESE IN 1988

TODAY’S REPORT PREPARED BY: Benjamin Turner