Sunday, January 31, 2021

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

SUNDAY, JANUARY 31, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0658E
SUNSET:  1657E

INCREASINGLY CLOUDY WITH LIGHT WINDS ATOP
GREAT BLUE HILL….

Today we observed more and more cloud cover as the day
went on. This was accompanied by a good visibility of
70 miles, and wind that was almost calm at times.

Today was, again, colder than normal.
The high temperature so far today is 23F, this is 11 degrees
below the daily normal maximum of 34F. The low since midnight
is 2F, which is 11 degrees below the normal minimum of 13F.

Today’s Observations:

7 A.M.
Weather: Scattered cirrostratus, few stratocumulus
offshore
Temperature: 3F; Dew Point: -4F; Relative Humidity: 72%
Wind: NNW @ 9 kts
Sea-level pressure: 30.34 in Hg; rising steadily
Visibility: 65 miles
6-hr Max temp: 8F
6-hr Min temp: 2F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 3 ins.
BHO SA 1155 250 SCT 65 273/3/-4/3309/034/ FEW SC OFFSHR/
8/506 4/003 53009 10008 20002

10 A.M.
Weather: Scattered stratocumulus, broken cirrostratus
Temperature: 13F; Dew Point: 1F; Relative Humidity: 59%
Wind: NW @ 4 kts, light and variable
Sea-level pressure: 30.35 in Hg; rising steadily
Visibility: 70 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 30 SCT 250 BKN 70 278/13/1/3204/035/ WND L/V/
8/506 53005

1 P.M.
Weather: Scattered stratocumulus, broken cirrostratus
Temperature: 20F, Dew point: 5F; Relative Humidity: 52%
Wind: E @ 4 kts, light and variable
Sea-level pressure: 30.30 inches Hg, falling steadily
Visibility: 70 miles
6-hr Max temp: 23F
6-hr Min temp: 3F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 2 ins.
BHO SA 1755 30 SCT 250 BKN 70 262/20/5/0904/030/ WND L/V/
8/506 4/002 58016 10023 20003

SUMMARY FOR SATURDAY, JANUARY 30, 2021

TEMPERATURE (DEGREES F)
MAX…….19   NORMAL…..34
MIN……..3   NORMAL…..17
MEAN……11   NORMAL…..26

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……..-15
TOTAL DEPARTURE FOR THE MONTH……………….+126 [+4.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………54  DEPARTURE……+15
TOTAL HEATING UNITS FOR THE MONTH………….1062  DEPARTURE…..-125
TOTAL HEATING UNITS FOR THE SEASON…………2992  DEPARTURE…..-499
TOTAL HEATING UNITS LAST SEASON TO DATE…….3198  DEPARTURE…..-206

PEAK WIND GUST (MPH):
420C/Official…………..24 NW  @  3:42 A.M.
AEROVANE (south tower)…..28 NW  @  3:43 A.M.
ASOS…………………..26 NW  @  3:42 A.M.
DAVIS #1……………….25 NNW @  3:11 A.M.
DAVIS #2 (south tower)…..25 NNW @  3:11 A.M.
RMY……………………27     @  3:41 A.M
VECTOR…………………29     @  3:41 A.M.
MERLIN…………………N/A

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………18 NW  @  1:18 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 NW  @  1:18 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………18 NW  @  3:11 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………18 NW  @  3:11 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..19 NNW @ 12:08 A.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..19     @ 12:07 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL….11.3 NW  [271 total miles] ASOS……………….11.0     [268 total miles] DAVIS #1……………11.8 NW  [283 total miles] DAVIS #2……………11.8 NW  [283 total miles] RMY………………..11.1 NW  [267 total miles] VECTOR……………..11.6     [271 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………….2.32  DEPARTURE….-1.90
ASOS………….2.35
TOTAL PRECIPITATION FOR THE YEAR…………..2.32  DEPARTURE….-1.90
ASOS…………2.35

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0  DEPARTURE…..-0.5
TOTAL SNOWFALL FOR THE MONTH……………… 7.1  DEPARTURE…..-9.5
TOTAL SNOWFALL FOR THE SEASON……………..33.3  DEPARTURE…..+0.7

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/+4/0.06/0.3/330/60       23 E    AERO 23 NNW  RMY 23
01/02   43/30/37/+10/0.30/T/116/21        37 WNW  AERO 39 WNW  RMY 44
01/03   33/27/30/+4/0.07/0.8/000/00       23 NNE  AERO 22 NNE  RMY 25
01/04   37/28/33/+7/0.01/0.1/110/20       25 NNE  AERO 23 NNE  RMY 27
01/05   31/28/30/+4/0.05/0.7/000/00       21 NNW  AERO 21 NNW  RMY 22
01/06   38/28/33/+7/T/T/244/44            30 NW   AERO 29 NW   RMY 32
01/07   42/26/34/+8/0.00/0.0/516/93       28 NNW  AERO 26 NNW  RMY 31
01/08   40/21/31/+5/0.00/0.0/517/93       25 NNW  AERO 22 NNW  RMY 25
01/09   34/30/27/+1/0.00/0.0/395/71       25 N    AERO 23 N    RMY 24
01/10   39/24/32/+7/0.00/0.0/493/88       25 NNW  AERO 23 NNW  RMY 24
01/11   34/25/30/+5/0.00/0.0/000/00       17 SW   AERO 16 SSW  RMY 16
01/12   40/24/32/+7/0.00/0.0/438/78       23 WNW  AERO 23 WNW  RMY 24
01/13   40/26/33/+8/0.00/0.0/389/69       15 SW   AERO 14 SW   RMY 19
01/14   38/31/35/+10/0.09/T/000/00        16 SSW  AERO 16 SSW  RMY 19
01/15   40/32/36/+11/0.00/0.0/266/47      25 ESE  AERO 23 ESE  RMY 27 TSTM
01/16   52/33/43/+18/1.00/0.0/000/00      48 ESE  AERO 53 SE   RMY 54
01/17   41/32/37/+12/0.00/0.0/314/55      47 W    AERO 46 W    RMY 54
01/18   42/27/35/+10/T/0.0/…/..         35 W    AERO 37 WNW  RMY 36
01/19   39/23/31/+6/T/T/…/..            25 WNW  AERO 25 WNW  RMY 27
01/20   37/22/30/+5/T/T/…/..            32 WNW  AERO 33 WNW  RMY 34
01/21   31/17/24/-1/T/0.1/…/..          23 WNW  AERO 24 SSW  RMY 24
01/22   42/29/36/+11/0.00/0.0/…/..      28 WNW  AERO 24 WNW  RMY 29
01/23   29/14/22/-3/0.00/0.0/…/..       41 WNW  AERO 41 WNW  RMY 46
01/24   29/13/21/-4/0.00/0.0/…/..       43 WNW  AERO 48 WNW  RMY 44
01/25   35/15/25/0/0.00/0.0/…/..        28 NW   AERO 29 NW   RMY 30
01/26   36/20/28/+3/…./2.4/…/..       18 E    AERO 18 E    RMY 20
01/27   33/27/30/+5/…./1.9/…/..       16 NNW  AERO 17 NNW  RMY 17
01/28   29/13/21/-4/…/0.9/…/..        39 NW  AERO 48 NW   RMY 42
01/29   15/4/10/-15/…./…/…/..       44 NW   AERO 46 NW   RMY 50
01/30   19/3/11/-15/0.00/0.0/…/..       24 NW   AERO 28 NW   RMY 27

01/31  The low since midnight is 2F, 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 31
HIGH 58F IN 1913, 1947, 2013
LOW -12F IN 1920
PRECIP 1.03 INS. IN 1914
SNOWFALL 9.0 INS. IN 1898
PEAK GUST 75 MPH NW IN 1974

RECORDS FOR FEBRUARY 1
HIGH 65F IN 1989
LOW -9F IN 1920
PRECIP 1.30 INS. IN 1898
SNOWFALL 11.0 INS. IN 1898
PEAK GUST 66e MPH SSW IN 1951

TODAY’S REPORT PREPARED BY: Benjamin Turner