Wednesday, January 13, 2021

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

WEDNESDAY, JANUARY 13, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0711E
SUNSET:  1635E

A SIMILAR DAY TO YESTERDAY, BEING PARTLY CLOUDY
AND WARMER THAN NORMAL….

The quiet and dry weather pattern continues. Following 5
consecutive days with measurable precipitation to open the
month, we’ve now gone the other way with the last 6 days
seeing not even a trace. Today will make day 7 of this dry
spell.

The monthly (and yearly) precipitation is only 0.49″, this
is now 1.21″ below normal for the month to date. Of course
below normal precipitation in January means we haven’t seen
much snow either with only 1.9″ measured for the month to
date. This is now 4.9″ below normal to date.

In addition to the dry conditions, temperatures have been
running above normal as well, with the month currently running
5.4 degrees above normal per day. It should be noted however,
that the majority of this “warmth” has been occurring at night,
with many of our daily low temperatures running 7-15 degrees
above normal. The coldest low temperature so far this month was
20 degrees back on the 9th, and this low was 3 degrees above
normal for the date. So this really gives a good indication of
where our above normal temperatures are coming from.

-Precipitation and Temperature section by Matt Douglas

As for today, generally a mix of sun and clouds have been
observed with rather hazy conditions thanks to another
inversion this morning. This inversion has been mixing out
early this afternoon with the visibility rising from
15-20 miles to about 65 miles. Wind is light, but has shifted
from northwest to south as the day went on. The max gust is only
14 mph.

The high temperature so far today is 41F, 7 degrees above the
daily normal maximum of 34F. The low since midnight is 26F,
9 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: Scattered stratocumulus, broken cirrostratus
Temperature: 27F; Dew Point: 23F; Relative Humidity: 84%
Wind: W at 7 kts
Sea-level pressure: 30.05 in Hg; rising steadily
Visibility: 15 miles, hazy
6-hr Max temp: 30F
6-hr Min temp: 26F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1155 55 SCT 250 BKN 15 176/27/23/2607/005/ HAZY/
8/506 53009 10030 20026

10 A.M.
Weather: Scattered stratocumulus, broken cirrostratus
Temperature: 34F; Dew Point: 24F; Relative Humidity: 65%
Wind: NW at 3 kts, light and variable
Sea-level pressure: 30.05 in Hg; rising, then more slowly
Visibility: 20 miles, hazy
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 55 SCT 250 BKN 20 177/34/24/3403/005/ HAZY WND L/V/
8/506 52001

1 P.M.
Weather: Scattered stratocumulus, broken cirrostratus
Temperature: 39F, Dew point: 24F; Relative Humidity: 54%
Wind: S at 7 kts
Sea-level pressure: 29.96 inches Hg, falling, then more slowly
Visibility: 65 miles
6-hr Max temp: 41F
6-hr Min temp: 27F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 50 SCT 250 BKN 65 144/39/24/1807/996/ 8/506 58033
10041 20027

SUMMARY FOR TUESDAY, JANUARY 12, 2021

TEMPERATURE (DEGREES F)
MAX…….40   NORMAL…..34
MIN…….24   NORMAL…..17
MEAN……32   NORMAL…..25

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……..+7
TOTAL DEPARTURE FOR THE MONTH……………….+69 [+5.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………33  DEPARTURE…….-7
TOTAL HEATING UNITS FOR THE MONTH…………..400  DEPARTURE……-68
TOTAL HEATING UNITS FOR THE SEASON…………2330  DEPARTURE…..-443
TOTAL HEATING UNITS LAST SEASON TO DATE…….2586  DEPARTURE…..-256

PEAK WIND GUST (MPH):
420C/Official…………..23 WNW  @ 10:56 A.M.
AEROVANE (south tower)…..23 WNW  @ 10:58 A.M.
ASOS…………………..24 NW   @ 10:51 A.M.
DAVIS #1……………….22 WNW  @ 10:45 A.M.
DAVIS #2 (south tower)…..22 NW   @ 12:37 P.M.
RMY……………………24      @ 10:56 A.M.
VECTOR…………………25      @  2:49 P.M.
MERLIN…………………24

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………15 WNW @  3:09 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 W   @  3:09 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………17 WNW @  2:52 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………17 W   @  3:09 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..15 W   @  3:06 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..15     @  2:49 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL… 9.0 WNW [216 total miles] ASOS……………… 9.3     [217 total miles] DAVIS #1………….. 9.8 WNW [236 total miles] DAVIS #2…………..10.0 WNW [240 total miles] RMY………………. 8.8 WNW [212 total miles] VECTOR……………. 9.4     [217 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….-1.21
ASOS………….0.48
TOTAL PRECIPITATION FOR THE YEAR…………..0.49  DEPARTURE….-1.21
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…..-4.9
TOTAL SNOWFALL FOR THE SEASON……………..28.1  DEPARTURE…..+5.3

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   34/25/30/+5/0.00/0.0/…/..       17 SW   AERO 16 SSW  RMY 16
01/12   40/24/32/+7/0.00/0.0/…/..       23 WNW  AERO 23 WNW  RMY 24

01/13 The low since midnight is 26F, 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 13
HIGH 60F IN 2018
LOW -10F IN 1912,1914
PRECIP 1.54 INS. IN 1979
SNOWFALL 12.6 INS. IN 1964
PEAK GUST 74 MPH NE IN 1964

RECORDS FOR JANUARY 14
HIGH 65F IN 1995
LOW -12F IN 1914
PRECIP 1.45 INS. IN 2008
SNOWFALL 10.3 INS. IN 2008
PEAK GUST 68 MPH WNW IN 1976, S IN 2005

TODAY’S REPORT PREPARED BY: Benjamin Turner