Monday, January 11, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
MONDAY, JANUARY 11, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0712E
SUNSET: 1633E
OVERCAST AND CHILLY, BUT QUIET TODAY ON THE HILL….
High clouds this morning have lowered to mid level clouds
early this afternoon. The sun has been dimly visible through
the clouds, but not enough to render a burn on our sun card
so far today.
Wind has been quite light today, generally steady at around
8 mph. High pressure over the region is the culprit for the
“dull” weather.
An inversion has been over the region all day. A thin smoke
layer trapped under this inversion has been visible since
mid morning. Our visibility started the day at around 55
miles, then jumped up to 80 miles above the inversion. It has
since dropped back to 40 miles as the level of the inversion
increased and allowed the hazy/smoke layer to rise obscuring
the views of both Mt Wachusett and Mt Monadnock to the WNW
and NW respectively.
The inversion is also holding temperatures down a bit today,
the high so far today is only 33F, 1 degree lower than the
daily normal maximum of 34F. The low since midnight is 25F,
8 degrees above the normal minimum of 17F.
PRELIMINARY STATS FOR DECEMBER 2020
TEMPERATURE, Deg. F
Avg. Max. 41.1 [+2.0]
Avg. Min. 27.2 [+3.6]
Mean 34.2 [+2.9]
24-hour corrected mean: 34.0
Max. for month: 62F on the 1st
Min. for month: 13F on the 16th and 19th
HEATING DEGREE DAYS
Total heating units: 957 [-86]
Total for the season: 1930 [-375]
Total for last season: 2251
PRECIPITATION, Inches
Total: 7.32 [+2.43]
Greatest in 24 hrs: 2.15 ins. on the 25th
SNOWFALL, Inches
Total: 19.7 [+6.3]
Greatest in 24 hrs: 16.5 ins. on the 16th-17th
WIND, mph
Avg. uncorrected wind speed: 13.0 mph
Avg. corrected wind speed: 13.3 mph
Prevailing wind direction: WNW [17%]
Peak gust and direction: 68 SSE on the 25th
SUNSHINE:
Campbell-Stokes card minutes: 6756 minutes of a possible 16470 or 41%
Astronomical total minutes: 6961 minutes of a possible 16991 or 41%
Today’s Observations:
7 A.M.
Weather: Broken cirrus
Temperature: 27F; Dew Point: 14F; Relative Humidity: 58%
Wind: SW at 7 kts
Sea-level pressure: 30.30 in Hg; rising, then more rapidly
Visibility: 55 miles
6-hr Max temp: 28F
6-hr Min temp: 25F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 E250 BKN 55 262/27/14/2207/030/ 8/001 53008 10028 20025
10 A.M.
Weather: Overcast cirrostratus, thin smoke layer along horizon
all quadrants
Temperature: 30F; Dew Point: 15F; Relative Humidity: 53%
Wind: SW at 6 kts
Sea-level pressure: 30.28 in Hg; falling, then more rapidly
Visibility: 80 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 E180 OVC 80 253/30/15/2206/028/ THN K LYR ALNG HRZN ALQDS SUN DMLY VSBL/ 8/007 58009
1 P.M.
Weather: Overcast altostratus, thin smoke layer all quadrants
Temperature: 33F, Dew point: 19F; Relative Humidity: 56%
Wind: WSW at 7 kts
Sea-level pressure: 30.20 inches Hg, falling, then more rapidly
Visibility: 40 miles, hazy
6-hr Max temp: 33F
6-hr Min temp: 27F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 E130 OVC 40 228/33/19/2407/020/ THN K LYR ALQDS SUN DMLY VSBL HAZY/ 8/01/ 58025 10033 20027
SUMMARY FOR SUNDAY, JANUARY 10, 2021
TEMPERATURE (DEGREES F)
MAX…….39 NORMAL…..34
MIN…….24 NORMAL…..17
MEAN……32 NORMAL…..25
DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……..+7
TOTAL DEPARTURE FOR THE MONTH……………….+57 [+5.5 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………33 DEPARTURE…….-7
TOTAL HEATING UNITS FOR THE MONTH…………..332 DEPARTURE……-57
TOTAL HEATING UNITS FOR THE SEASON…………2262 DEPARTURE…..-431
TOTAL HEATING UNITS LAST SEASON TO DATE…….2564 DEPARTURE…..-302
PEAK WIND GUST (MPH):
420C/Official…………..25 NNW @ 2:43 A.M.
AEROVANE (south tower)…..23 NNW @ 2:43 A.M.
ASOS…………………..23 NNW @ 2:43 A.M.
DAVIS #1……………….23 NNW @ 2:43 A.M.
DAVIS #2 (south tower)…..24 N @ 2:43 A.M.
RMY……………………24 @ 2:42 A.M.
VECTOR…………………25 @ 2:46 A.M.
MERLIN…………………N/A
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………16 NNW @ 2:44 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 NNW @ 6:50 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………17 NW @ 2:43 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………18 NNW @ 2:44 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..16 NNW @ 6:47 A.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..16 @ 2:40 A.M.
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL… 9.0 NW [215 total miles]
ASOS……………… 9.7 [233 total miles]
DAVIS #1………….. 9.6 NNW [230 total miles]
DAVIS #2………….. 9.5 NNW [228 total miles]
RMY………………. 9.1 NNW [218 total miles]
VECTOR……………. 9.5 [228 total miles]
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.00 DEPARTURE….-0.14
ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….0.49 DEPARTURE….-0.93
ASOS………….0.48
TOTAL PRECIPITATION FOR THE YEAR…………..0.49 DEPARTURE….-0.93
ASOS…………0.48
SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0 DEPARTURE…..-0.6
TOTAL SNOWFALL FOR THE MONTH……………… 1.9 DEPARTURE…..-3.8
TOTAL SNOWFALL FOR THE SEASON……………..28.1 DEPARTURE…..+6.4
PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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
12/01 62/40/51/+14/0.61/0.0/112/20 60 S AERO 67 W RMY 64
12/02 42/32/37/+1/0.00/0.0/301/54 32 SW AERO 32 SW RMY 35
12/03 49/30/40/+4/0.00/0.0/512/92 25 SSW AERO 25 SSW RMY 28
12/04 58/40/49/+14/0.06/0.0/332/60 35 SSW AERO 35 SSW RMY 37
12/05 42/32/37/+2/2.13/2.8/000/00 58 NNW AERO 58 NNW RMY 67
12/06 34/26/30/-5/0.01/T/403/73 E44 WNW AERO 44 WNW RMY 49
12/07 33/22/28/-6/T/T/457/83 24 NW AERO 26 NW RMY 26
12/08 29/22/26/-8/T/T/006/01 24 NW AERO 25 NW RMY 28
12/09 34/19/27/-7/T/T/000/00 16 W AERO 17 W RMY 19
12/10 42/30/36/+3/0.00/0.0/351/64 30 WNW AERO 31 WNW RMY 29
12/11 50/31/41/+8/0.00/0.0/384/70 32 SW AERO 35 SW RMY 34
12/12 48/40/44/+11/0.38/0.0/000/00 25 E AERO 21 E RMY 25
12/13 58/35/47/+15/0.00/0.0/109/20 28 W AERO 31 WSW RMY 31
12/14 35/30/33/+1/0.10/0.4/000/00 25 N AERO 25 N RMY 29
12/15 34/21/28/-4/0.00/0.0/541/99 32 WNW AERO 33 WNW RMY 38
12/16 27/13/20/-11/0.14/1.4/180/33 38 E AERO 37 E RMY 39
12/17 31/19/25/-6/1.58/15.1/000/00 55 ENE AERO 56 ENE RMY 59
12/18 27/18/23/-8/0.00/0.0/120/22 28 N AERO 26 N RMY 27
12/19 29/13/21/-9/0.00/0.0/436/80 16 SW AERO 16 S RMY 16
12/20 36/24/30/0/0.02/T/000/00 14 S AERO 16 SW RMY 14
12/21 34/29/32/+2/0.00/0.0/000/00 22 WNW AERO 24 WNW RMY 23
12/22 42/30/36/+7/0.00/0.0/447/82 34 WNW AERO 35 WNW RMY 38
12/23 37/26/32/+3/0.00/0.0/480/88 30 WNW AERO 28 WNW RMY 31
12/24 53/30/42/+13/T/0.0/153/28 46 SSE AERO 50 SSE RMY 55
12/25 61/37/49/+21/2.15/0.0/000/00 68 SSE AERO 77 SSE RMY 84
12/26 37/25/31/+3/0.00/0.0/485/89 38 SW AERO 44 SW RMY 43
12/27 38/22/30/+2/0.00/0.0/513/94 18 W AERO 18 W RMY 20
12/28 49/27/38/+10/T/0.0/109/20 35 SSW AERO 36 – RMY 37
12/29 38/20/29/+2/0.00/0.0/470/86 48 WNW AERO 50 WNW RMY 56
12/30 40/19/30/+3/0.00/0.0/060/11 39 SW AERO 41 SW RMY 45
12/31 44/28/36/+9/0.14/0.0/000/00 38 SW AERO 43 SW RMY 43
DAILY RECORDS FOR DECEMBER 2020
12/17/20: DAILY RECORD SNOWFALL OF 15.1 INCHES,
BREAKS PREVIOUS RECORD OF 7.5 INCHES SET IN 1988
12/25/20: DAILY RECORD PRECIPITATION OF 2.15 INCHES,
BREAKS PREVIOUS RECORD OF 1.37 INCHES SET IN 2002
PRELIMINARY CLIMATE SUMMARY FOR JANUARY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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
01/01 36/25/31/+4/0.06/0.3/…/.. 23 E AERO 23 NNW RMY 23
01/02 43/30/37/+10/0.30/T/…/.. 37 WNW AERO 39 WNW RMY 44
01/03 33/27/30/+4/0.07/0.8/…/.. 23 NNE AERO 22 NNE RMY 25
01/04 37/28/33/+7/0.01/0.1/…/.. 25 NNE AERO 23 NNE RMY 27
01/05 31/28/30/+4/0.05/0.7/…/.. 21 NNW AERO 21 NNW RMY 22
01/06 38/28/33/+7/T/T/…/.. 30 NW AERO 29 NW RMY 32
01/07 42/26/34/+8/0.00/0.0/…/.. 28 NNW AERO 26 NNW RMY 31
01/08 40/21/31/+5/0.00/0.0/…/.. 25 NNW AERO 22 NNW RMY 25
01/09 34/30/27/+1/0.00/0.0/…/.. 25 N AERO 23 N RMY 24
01/10 39/24/32/+7/0.00/0.0/…/.. 25 NNW AERO 23 NNW RMY 24
01/11 The low since midnight is 25F, the daily normal low is 17F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR JANUARY 11
HIGH 65F IN 2020
LOW -7F IN 1968
PRECIP 1.58 INS. IN 2008
SNOW 10.2 INS. 1927
PEAK GUST 95e MPH S IN 1980
RECORDS FOR JANUARY 12
HIGH 68F IN 2020 [RECORD FOR MONTH]
LOW -15F IN 1886
PRECIP 2.04 INS. IN 2011
SNOW 18.2 INS. IN 2011
WIND 84e MPH S IN 1980
TODAY’S REPORT PREPARED BY: Matt Douglas
