Friday, January 29, 2021

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

FRIDAY, JANUARY 29, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0700E
SUNSET:  1655E

VERY COLD, BLUSTERY, MOSTLY CLOUDY ATOP GREAT BLUE HILL…

Yesterday’s light snow scooted off to our east as an
arctic air mass arrived in its place. Winds quickly
ramped up around dinnertime peaking at 39 MPH just
before 9 PM. With a low temperature this morning of
just 4F and winds consistently peaking around 30-35 MPH,
wind chill values were around -20F! It is worth noting
that we have not reached 4F or lower since January 20th,
2019…approximately 2 years ago!

Through the morning, winds have continued to be busy out of
the northwest and temperatures have not responded much since
the 4F low. Wind chill values are in the negative single digits
and the high so far is 14F. We have observed passing virga to
our east as a trough extending from a powerful ocean storm throws
coastal locales some light snow. No flakes have been seen so far
today though. In the sectors where there is no falling snow
(SW-NW), visibility is an excellent 75 miles on average.

The high temperature so far today is 14F, this is 20 degrees below
the daily normal maximum of 34F. The low since midnight is 4F,
which is 9 degrees below the normal minimum of 13F.

Today’s Observations:

7 A.M.
Weather: Scattered Stratocumulus & Cumulus, Scattered Altocumulus
(line of stratocumulus offshore)
Temperature: 4F; Dew Point: -6F; Relative Humidity: 62%
Wind: NW @ 15G25 kts (Peak Wind: 32 kts/37 MPH WNW @ 6:49 AM)
Sea-level pressure: 29.89 in Hg; falling, then rising
Visibility: 50 miles
6-hr Max temp: 12F
6-hr Min temp: 4F
24-hr Precip: 0.06 ins.
24-hr Snow: 0.6 ins.
Snow Depth: 3 ins.
BHO SA 1155 40 SCT 120 SCT 50 122/4/-6/3115G25/989/ LINE
SC OFFSHR TOTAL NEW SNW PST 24 HRS 0.6 INS PK WND 2932/1149/
8/550 4/003 53002 70006 10012 20004

10 A.M.
Weather:  Broken Cumulus, Broken Stratocumulus, Virga NE-SE
Temperature: 7F; Dew Point: -6F; Relative Humidity: 60%
Wind: NW @ 19G34 kts (Peak Wind: 34 kts/39 MPH NW @ 9:23 AM)
Sea-level pressure: 29.89 in Hg; rising, then falling
Visibility: 80 miles (15 miles NE-SE)
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 40 BKN 70 BKN 80 121/7/-6/3119G34/989/ VIRGA NE-SE
VSBY 15 NE-SE PK WND 3134/1423/ 8/500 58001

1 P.M.
Weather: Broken Stratus, Virga N-SE
Temperature: 14F, Dew point: -2F; Relative Humidity: 48%
Wind: NW @ 21G32 kts (Peak Wind: 32 kts/37 MPH NNW @ 12:55 PM)
Sea-level pressure: 29.85 inches Hg, falling unsteadily
Visibility: 70 miles (20 miles N-SE)
6-hr Max temp: 14F
6-hr Min temp: 4F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 3 ins.
BHO SA 1755 50 BKN 70 108/14/-2/3121G32/985/ VIRGA N-SE
VSBY 20 N-SE PK WND 3332/1755/ 8/600 4/003 57013 10014 20004

SUMMARY FOR THURSDAY, JANUARY 28, 2021

TEMPERATURE (DEGREES F)
MAX…….29   NORMAL…..34
MIN…….13   NORMAL…..17
MEAN……21   NORMAL…..25

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL………-4
TOTAL DEPARTURE FOR THE MONTH……………….+156 [+5.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………44  DEPARTURE…… -4
TOTAL HEATING UNITS FOR THE MONTH…………..953  DEPARTURE…..-155
TOTAL HEATING UNITS FOR THE SEASON…………2883  DEPARTURE…..-529
TOTAL HEATING UNITS LAST SEASON TO DATE…….3124  DEPARTURE…..-241

PEAK WIND GUST (MPH):
420C/Official…………..39 NW @  8:55 P.M.
AEROVANE (south tower)…..48 NW @ 11:17 P.M.
ASOS…………………..39 NW @  8:55 P.M.
DAVIS #1……………….39 NW @  7:58 P.M.
DAVIS #2 (south tower)…..41 NW @ 11:17 P.M.
RMY……………………42    @  8:53 P.M
VECTOR…………………44    @  8:40 P.M.
MERLIN…………………42

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………28 NW  @  8:42 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….26 NW  @ 11:31 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………28 NW  @  8:43 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………27 NW  @  7:09 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..26 NNW @  7:05 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..27     @  7:07 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL….13.8 NNW [331 total miles] ASOS……………….13.6     [326 total miles] DAVIS #1……………13.7 NNW [329 total miles] DAVIS #2……………13.7 NNW [329 total miles] RMY………………..13.0 NNW [312 total miles] VECTOR……………..13.6     [326 total miles]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.06  DEPARTURE….-0.08
ASOS………….0.05
TOTAL PRECIPITATION FOR THE MONTH………….2.32  DEPARTURE….-1.62
ASOS………….2.35
TOTAL PRECIPITATION FOR THE YEAR…………..2.32  DEPARTURE….-1.62
ASOS…………2.35

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.6  DEPARTURE…-/+0.0
TOTAL SNOWFALL FOR THE MONTH……………… 7.1  DEPARTURE…..-8.4
TOTAL SNOWFALL FOR THE SEASON……………..33.3  DEPARTURE…..+1.8

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  The low since midnight is 4F, 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 29
HIGH 66F IN 2002
LOW -11F IN 1888
PRECIP 1.48 INS. IN 1973
SNOWFALL 8.0 INS. IN 1943
PEAK GUST 72 MPH NW IN 1973

RECORDS FOR JANUARY 30
HIGH 60F IN 1914
LOW -8F IN 1948
PRECIP 1.12 INS. IN 1925
SNOWFALL 6.5 INS. IN 1986
PEAK GUST 76 MPH WNW IN 1962

TODAY’S REPORT PREPARED BY: Andrew Swanson