Thursday, February 4, 2021

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

THURSDAY, FEBRUARY 4, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0654E
SUNSET:  1703E

SNOWY START GIVES WAY TO DEVELOPING SUNSHINE…

While only 0.7 inches of snow fell early this morning, it did
make the summit road rather treacherous during our early
morning ascent to the top. The morning snow now brings us
to 15.2 inches on the month and 48.6 inches on the season!

Visibility gradually improved throughout the morning hours
from 20 miles to 80 miles by the 1 PM observation. Some
sunshine was introduced mid-morning though we have seen
more clouds than sun. It seems sunshine has been very hard to
come by since last Sunday.

As high pressure builds in today, our winds have relaxed – only
reaching 17 MPH so far. It appears we will return to cloudy
and rainy weather tomorrow.

The high temperature so far today is 37F, this is 2 degrees
above the daily normal maximum of 35F. The low since midnight
is 26F, which is 9 degrees above the normal minimum of 17F.

PRELIMINARY STATS FOR JANUARY 2021

TEMPERATURE, Deg. F
Avg. Max. 35.4 [+1.6] Avg. Min. 22.5 [+5.4] Mean      28.9 [+3.4] 24-hour corrected mean: 28.8
Max. for month: 52F on the 16th
Min. for month: 2F on the 31st

HEATING DEGREE DAYS
Total heating units:   1114 [-112] Total for the season:  3044 [-487] Total for last season: 3531

PRECIPITATION, Inches
Total: 2.32 [-2.03] Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: 7.2 [-9.9] Greatest in 24 hrs: N/A

WIND, mph
Avg. uncorrected wind speed: 11.1 mph
Avg. corrected wind speed:   11.7 mph
Prevailing wind direction:   NW [25%] Peak gust and direction:     48 ESE on the 16th

SUNSHINE:
Campbell-Stokes card minutes: N/A
Astronomical total minutes: N/A

Today’s Observations:

7 A.M.
Weather: Light snow, Overcast Stratus Fractus (precipitation very light)
Temperature: 26F; Dew Point: 26F; Relative Humidity: 100%
Wind: NW @ 6 kts  (wind light)
Sea-level pressure: 29.70 in Hg; rising, then rising more rapidly
Visibility: 20 miles
6-hr Max temp: 28F
6-hr Min temp: 26F
24-hr Precip: 0.02 ins.
24-hr Snow: 0.7 ins.
Snow Depth: 10 ins.
BHO SA 1155 40 OVC 20S- 057/26/26/3106/970/ PCPN VRY LGT
NEW SNW PST 24 HRS 0.7 INS WND LGT/ 8/6// 4/010 53026 6002/ 70002
10028 20026

10 A.M.
Weather: Scattered Stratocumulus, Broken Altocumulus, Broken Cirrus
Temperature: 32F; Dew Point: 24F; Relative Humidity: 72%
Wind: NNW @ 13G21 kts
Sea-level pressure: 29.75 in Hg; rising, then rising more slowly
Visibility: 80 miles
3-hr Precip: Trace
3-hr Snow: Trace
BHO SA 1455 45 SCT E120 BKN E250 BKN 80 074/32/24/3313G21/975/
NEW SNW PST 3 HRS TRACE/ 8/552 6000/ 51017

1 P.M.
Weather: Broken Stratocumulus, Broken Altocumulus
Temperature: 35F, Dew point: 24F; Relative Humidity: 63%
Wind: NNW @ 9 kts
Sea-level pressure: 29.74 in Hg, steady, then falling
Visibility: 75 miles
6-hr Max temp: 37F
6-hr Min temp: 26F
6-hr Precip: Trace
6-hr Snow: Trace
Snow Depth: 10 ins.
BHO SA 1755 40 BKN 70 BKN 75 072/35/24/3309/974/ NEW SNW PST 6 HRS TRACE/
8/550 4/010 58002 6000/ 10037 20026

SUMMARY FOR WEDNESDAY, FEBRUARY 3, 2021

TEMPERATURE (DEGREES F)
MAX…….34   NORMAL…..35
MIN…….26   NORMAL…..17
MEAN……30   NORMAL…..26

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……… +4
TOTAL DEPARTURE FOR THE MONTH…………………+11 [+3.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………35  DEPARTURE…… -4
TOTAL HEATING UNITS FOR THE MONTH…………. 106  DEPARTURE….. -12
TOTAL HEATING UNITS FOR THE SEASON…………3150  DEPARTURE…..-498
TOTAL HEATING UNITS LAST SEASON TO DATE…….3319  DEPARTURE…..-169

PEAK WIND GUST (MPH):
420C/Official…………..20 NW  @  6:24 A.M.
AEROVANE (south tower)…..20 NW  @ 10:50 P.M.
ASOS…………………..22 NW  @  6:25 A.M.
DAVIS #1……………….20 NW  @  6:24 A.M.
DAVIS #2 (south tower)…..20 NW  @ 11:02 P.M.
RMY……………………22     @  3:17 P.M
VECTOR…………………21     @ 10:49 P.M.
MERLIN…………………21

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………16 NW  @ 6:27 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 NW  @ 6:31 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………16 NW  @ 6:26 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………15 NW  @ 3:16 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..15 NNW @ 3:12 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..14     @ 3:12 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL….9.3 WNW [224 total miles] ASOS……………….9.7
DAVIS #1……………9.6 NW
DAVIS #2……………9.8 NW
RMY………………..M
VECTOR……………..M

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.02  DEPARTURE….-0.12
ASOS………….0.02
TOTAL PRECIPITATION FOR THE MONTH………….2.80  DEPARTURE….+2.40
ASOS………….3.06
TOTAL PRECIPITATION FOR THE YEAR…………..5.12  DEPARTURE….+0.37
ASOS…………5.41

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.7  DEPARTURE…..+0.2
TOTAL SNOWFALL FOR THE MONTH………………15.2  DEPARTURE….+13.7
TOTAL SNOWFALL FOR THE SEASON……………..48.6  DEPARTURE….+14.0

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/0.0/366/64         35 W    AERO 37 WNW  RMY 36
01/19   39/23/31/+6/T/T/293/51            25 WNW  AERO 25 WNW  RMY 27
01/20   37/22/30/+5/T/T/144/25            32 WNW  AERO 33 WNW  RMY 34
01/21   31/17/24/-1/T/0.1/081/14          23 WNW  AERO 24 SSW  RMY 24
01/22   42/29/36/+11/0.00/0.0/226/39      28 WNW  AERO 24 WNW  RMY 29
01/23   29/14/22/-3/0.00/0.0/442/76       41 WNW  AERO 41 WNW  RMY 46
01/24   29/13/21/-4/0.00/0.0/571/98       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/+3/0.17/2.4/…/..       18 E    AERO 18 E    RMY 20
01/27   33/27/30/+5/0.12/1.9/…/..       16 NNW  AERO 17 NNW  RMY 17
01/28   29/13/21/-4/0.09/0.9/…/..       39 NW   AERO 48 NW   RMY 42
01/29   15/4/10/-15/0.00/0.0/…/..       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   23/2/13/-13/0.00/0.0/…/..       18 NW   AERO 18 NW   RMY 19

PRELIMINARY CLIMATE SUMMARY FOR FEBRUARY 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

02/01   32/21/27/+1/1.86/12.7/…/..      53 NE   AERO 65 NE   RMY 62
02/02   34/29/32/+6/…./…/…/..       52 NNE  AERO 55 NE   RMY 58
02/03   34/26/30/+4/…/…/…/..        20 NW   AERO 20 NW   RMY 22

02/04 The low since midnight is 26F, the daily normal low is 17F

DAILY RECORDS

02/01 -RECORD SNOWFALL OF 12.7 INS, BREAKING PREVIOUS RECORD
OF 11.0 INS SET IN 1898
02/01 -RECORD PRECIPITATION OF 1.86 INS, BREAKING PREVIOUS
RECORD OF 1.30 INS SET IN 1898

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

RECORDS FOR FEBRUARY 4
HIGH 63F IN 1991
LOW -4F IN 1886, 1908
PRECIP 1.80 INS. IN 1926
SNOWFALL 15.0 INS. IN 1961
PEAK GUST 89 MPH SSE IN 1972

RECORDS FOR FEBRUARY 5
HIGH 65F IN 1991
LOW -14F IN 1918
PRECIP 1.55 INS. IN 2001
SNOWFALL 16.0 INS. IN 1907
PEAK GUST 67 MPH WNW IN 1969

TODAY’S REPORT PREPARED BY: Andrew Swanson