Friday, October 30, 2020

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

FRIDAY, OCTOBER 30, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

RECORD SETTING SNOW BLANKETS THE PEAK OF GREAT BLUE HILL…

We began the drive up to the summit around 5:35 AM this morning.
At the base, only rainfall was observed with the car reading 36
degrees. About halfway up the access road (~350ft), rain changed
to snow! By 7AM, we measured 0.2 inches on the snowboard. A running
snowfall total then commenced – 3.0 inches by 10AM, followed by 5.1
inches at our concluding observation at 1PM. Our final snowfall total
for today comes in at 6.5 inches! This sets a new daily record
shattering the previous 2.0 inches set in 2011. 6.5 inches
also marks the 2nd highest daily October snowfall. The maximum
remains 6.8 inches on October 10th, 1979!

Anomalously cold air created excellent snow accumulation conditions.
The air was 32 degrees at 7AM and it slipped quickly to the upper-20s
where it has held remarkably stable at 28 degrees since just after the
10AM observation. Very impressive stuff for late October!

The high so far today is 41F set at midnight, this is 15 degrees
below the daily normal maximum of 56F. The low since midnight is
28F, which is 11 degrees below the daily normal minimum of 39F.

Today’s Observations:

7 A.M.
Weather: Moderate Snow (sky obscured, vertical visibility 300ft)
Temperature: 32F; Dew Point: 32F; Relative Humidity: 100%
Wind: N at 8G23 kts
Sea-level pressure: 29.83 ins. Hg: falling, then rising
Visibility: 1/16 mile, fog
6-hr Max temp: 41F
6-hr Min temp: 32F
24-hr Precip: 1.58 ins.
24-hr Snow: 0.2 ins
BHO SA 1155 X W3 1/16SF 100/32/32/3508G23/983/ SCTD
TOTAL NEW SNW PST 24 HRS 0.2 INS/ 8//// 4/000 53014 70158 10041 20032

10 A.M.
Weather: Moderate Snow (sky obscured, vertical visibility 300ft)
Temperature: 29F; Dew Point: 29F; Relative Humidity: 100%
Wind: N at 13G21 kts
Sea-level pressure: 29.87 ins. Hg: rising, then steady
Visibility: 1/8 mile, fog
3-hr Precip: 0.31 ins.
3-hr Snow: 2.8 ins
BHO SA 1455 X W3 1/8SF 114/29/29/3513G21/987/ SCTD
TOTAL NEW SNW PST 3 HRS 2.8 INS/ 8//// 51014 6031/

1 P.M.
Weather: Light snow (sky obscured, vertical visibility 300ft)
Temperature: 28F; Dew Point: 28F; Relative Humidity: 100%
Wind: NNW at 12G20 kts
Sea-level pressure: 29.93 ins. Hg: rising, then rising more rapidly
Visibility: 1/4 mile, fog
6-hr Max temp: 32F
6-hr Min temp: 28F
6-hr Precip: 0.21 ins.
6-hr Snow: 4.9 ins.
Snow Depth: 5 ins.
BHO SA 1755 X W3 1/4S-F 134/28/28/3412G20/993/ S-CTD
TOTAL NEW SNW PST 6 HRS 4.9 INS/ 8//// 4/005 53020 6021/
10032 20028

SUMMARY FOR THURSDAY, OCTOBER 29, 2020

TEMPERATURE (DEGREES F)
MAX…..46   NORMAL…..56
MIN…..41   NORMAL…..39
MEAN….44   NORMAL…..47

DEPARTURE FROM 30-YEAR NORMAL……………. -3
TOTAL DEPARTURE FOR THE MONTH…………….+89 [+2.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….21  DEPARTURE….. +3
TOTAL HEATING UNITS FOR THE MONTH…………290  DEPARTURE…..-95
TOTAL HEATING UNITS FOR THE SEASON………..388  DEPARTURE….-139
TOTAL HEATING UNITS LAST SEASON TO DATE……431  DEPARTURE…..-43

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……………39 NE  AT  11:38 P.M.
AEROVANE (south tower)……38 NE  AT  11:47 P.M.
ASOS……………………38 NE  AT   9:16 P.M
DAVIS #1………………..39 ENE AT   9:16 P.M
DAVIS #2 (south tower)……39 NE  AT  11:50 P.M
VECTOR………………….43
RMY…………………….38
MERLIN………………….41

FASTEST MILE FOR YESTERDAY…………………24 NE  AT  11:34 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………23 NE  AT  11:53 P.M
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…………..24 NNE AT  11:19 P.M
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE…………..25 NE  AT  11:52 P.M
AVERAGE WIND SPEED AND DIRECTION…………. 8.7 NNE [209 total miles] ASOS…………………. 9.0
DAVIS #1……………… 9.1 NNE [24 deg.] DAVIS #2……………… 9.2 NNE [23 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….1.58  DEPARTURE….+1.43
ASOS…………..1.56
TOTAL PRECIPITATION FOR THE MONTH……….6.13  DEPARTURE….+1.75
ASOS…………..6.08
TOTAL PRECIPITATION FOR THE YEAR……….40.55  DEPARTURE….-2.91
ASOS………….41.29

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/+9/0.00/591/84             28 SW   AERO 28 SW   RMY N/A
10/02  63/49/56/-1/0.02/203/29             20 NW   AERO 21 NW   RMY 20
10/03  65/45/55/-1/0.00/676/97             19 WNW  AERO 19 WNW  RMY 19
10/04  65/45/55/-1/0.00/659/95             17 ESE  AERO 18 ESE  RMY 18
10/05  62/52/57/+1/0.00/277/40             17 ENE  AERO 17 ENE  RMY N/A
10/06  69/51/60/+5/0.00/503/73             28 S    AERO 28 S    RMY 29
10/07  73/50/62/+7/0.14/316/46             76 W    AERO 74 W    RMY 70  TSTM
10/08  61/42/52/-2/0.00/676/99             41 W    AERO 41 W    RMY N/A
10/09  60/37/49/-5/0.00/646/95             25 SSW  AERO 28 SSW  RMY N/A
10/10  75/52/64/+10/0.00/549/81            40 SSW  AERO 40 SSW  RMY 38
10/11  64/47/56/+3/0.00/574/85             32 NNW  AERO 35 NNW  RMY N/A
10/12  52/48/50/-3/T/000/00                28 E    AERO 27 E    RMY N/A
10/13  57/49/53/0/1.74/000/00              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/+7/1.00/…/..             28 S    AERO 30 S    RMY N/A
10/17  56/39/48/-3/1.24/…/..             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  71/56/64/+14/0.06/…/..            26 SSW  AERO 26 SSW  RMY 26
10/22  70/54/62/+13/0.00/…/..            18 SSW  AERO 17 SSW  RMY N/A
10/23  68/52/60/+11/0.00/…/..            18 ESE  AERO 18 ESE  RMY 18
10/24  68/42/55/+6/0.00/…/..             32 NNW  AERO 32 NNW  RMY 32
10/25  50/40/45/-4/0.00/…/..             19 NNW  AERO 19 NNW  RMY N/A
10/26  52/43/48/0/0.02/…/..              20 E    AERO 18 ESE  RMY 20
10/27  52/43/48/0/0.00/…/..              22 NNW  AERO 22 NNW  RMY N/A
10/28  49/42/46/-2/…./…/..             18 W    AERO 18 W    RMY 18
10/29  46/41/44/-3/…/…/..              39 NE   AERO 38 NE   RMY 38

10/30 The low since midnight is 28, the daily normal low is 39F

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

RECORDS FOR OCTOBER 30
HIGH 75F IN 1946,1989
LOW 21F IN 1928
PRECIP 1.85 INCHES IN 1917
SNOWFALL 2.0 INCHES IN 2011
PEAK GUST 66 NW IN 1963

RECORDS FOR OCTOBER 31
HIGH 79F IN 1946
LOW 22F IN 1904
PRECIP 3.74 INCHES IN 1991
SNOWFALL TRACE IN 1906
PEAK GUST 70e S IN 1945

TODAY’S REPORT PREPARED BY: Andrew Swanson