Sunday, February 21, 2021

| February 21, 2021 | Reply

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

SUNDAY, FEBRUARY 21, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0633E
SUNSET:  1724E

A FAIR WEATHER DAY WITH EXCELLENT VISIBILITY
ATOP GREAT BLUE HILL….

Today we observed almost clear skies with an excellent
85 miles of visibility. This followed a significant
pressure increase of more than 20 millibars overnight.
Dew points are now also in the lower teens, with a
humidity approaching 40%.

We are open until 4 P.M., come on in and enjoy the view
from the roof!

The high so far today is 31F, 7 degrees below the daily
average max of 38F. The low since midnight is 15F, 5 degrees
below the daily average low of 20F.

Today’s Observations:

7 A.M.
Weather: Few cumulus offshore
Temperature: 15F; Dew Point: 10F; Relative Humidity: 80%
Wind: NW @ 11G16 kts
Sea-level pressure: 30.35 in Hg; rising steadily
Visibility: 80 miles
6-hr Max temp: 18F
6-hr Min temp: 15F
24-hr Precip: Trace
24-hr Snow: Trace
Snow Depth: 17 ins.
BHO SA 1155 CLR 80 276/15/10/3111G16/035/ FEW CU OFFSHR
NEW SNW PST 24 HRS TRACE/ 8/100 4/017 51025 10018 20015

10 A.M.
Weather: Few cumulus
Temperature: 25F; Dew Point: 11F; Relative Humidity: 55%
Wind: NNW @ 11G20 kts
Sea-level pressure: 30.42 in Hg; rising steadily
Visibility: 85 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 CLR 85 301/25/11/3311G20/042/ FEW CU ALQDS/
8/100 51025

1 P.M.
Weather: Few cumulus
Temperature: 30F, Dew point: 11F; Relative Humidity: 45%
Wind: NW @ 8 kts
Sea-level pressure: 30.43 in Hg, falling then rising
Visibility: 85 miles
6-hr Max temp: 31F
6-hr Min temp: 15F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 17 ins.
BHO SA 1755 CLR 85 303/30/11/3208/043/ FEW CU ALQDS/ 8/100
4/017 50002 10031 20015

SUMMARY FOR SATURDAY, FEBRUARY 20, 2021

TEMPERATURE (DEGREES F)
MAX…….32   NORMAL…..38
MIN…….19   NORMAL…..20
MEAN……26   NORMAL…..29

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL…… -3
TOTAL DEPARTURE FOR THE MONTH……………….-2 [-0.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………39  DEPARTURE…….+3
TOTAL HEATING UNITS FOR THE MONTH…………..757  DEPARTURE……..0
TOTAL HEATING UNITS FOR THE SEASON…………3801  DEPARTURE…..-486
TOTAL HEATING UNITS LAST SEASON TO DATE…….3883  DEPARTURE……-82

PEAK WIND GUST (MPH):
420C/Official…………..32 NW  @ 10:43 P.M.
AEROVANE (south tower)…..35 NW  @ 10:42 P.M.
ASOS…………………..33 NW  @ 10:45 P.M.
DAVIS #1……………….34 NW  @ 10:44 P.M.
DAVIS #2 (south tower)…..31 W   @ 10:40 P.M.
RMY……………………38     @ 10:43 P.M.
VECTOR…………………38     @ 11:10 P.M.
MERLIN…………………34

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………22 NW  @ 10:46 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….22 NW  @ 10:46 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………22 W   @ 10:46 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………22 W   @ 10:45 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..22 NNW @ 10:42 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..23     @ 10:42 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……10.5 NW [253 total miles]
ASOS…………………10.7
DAVIS #1……………..10.6 NNW
DAVIS #2……………..10.6 NNW
RMY………………….10.2 NNW
VECTOR……………….10.8

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……TRACE  DEPARTURE….-0.15
ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….5.24  DEPARTURE….+2.43
ASOS………….5.42
TOTAL PRECIPITATION FOR THE YEAR…………..7.56  DEPARTURE….+0.40
ASOS…………7.77

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0  DEPARTURE…. -0.5
TOTAL SNOWFALL FOR THE MONTH………………38.9  DEPARTURE….+29.0
TOTAL SNOWFALL FOR THE SEASON……………..72.3  DEPARTURE….+29.3

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/+1/1.86/12.7/000/00      53 NE   AERO 65 NE   RMY 62
02/02   34/29/32/+6/0.91/1.6/000/00       52 NNE  AERO 55 NE   RMY 58
02/03   34/26/30/+4/0.01/0.2/036/06       20 NW   AERO 20 NW   RMY 22
02/04   37/26/32/+6/0.02/0.7/158/26       23 NW   AERO 22 NW   RMY M
02/05   39/26/33/+7/0.01/T/000/00         33 S    AERO 32 S    RMY 30
02/06   40/28/34/+8/0.00/0.0/595/97       42 WSW  AERO 41 WSW  RMY 47
02/07   35/25/30/+3/0.71/11.6/000/00      27 WNW  AERO 28 WNW  RMY 30
02/08   27/13/20/-7/0.00/0.0/619/100      29 NW   AERO 31 WNW  RMY 32
02/09   27/18/23/-4/0.17/2.2/000/00       16 N    AERO 16 N    RMY 17
02/10   31/15/23/-4/0.00/0.0/…/..       26 WNW  AERO 25 WNW  RMY 28
02/11   31/15/23/-4/0.00/0.0/…/..       28 NW   AERO 26 NW   RMY 31
02/12   25/8/17/-10/0.00/0.0/…/..       32 NW   AERO 35 NW   RMY 36
02/13   27/15/21/-7/0.00/0.0/…/..       20 NNW  AERO 20 NNW  RMY 23
02/14   34/24/29/+1/0.00/0.0/…/..       19 ENE  AERO 16 ENE  RMY 19
02/15   31/27/29/+1/0.11/0.0/…/..       21 NNE  AERO 21 NNE  RMY 22
02/16   44/29/37/+9/0.63/0.0/…/..       39 W    AERO 41 W    RMY 43
02/17   30/19/25/-3/0.00/0.0/…/..       40 W    AERO 41 WNW  RMY 40
02/18   29/21/25/-4/…/…/…/..        24 ENE  AERO 24 ENE  RMY 25
02/19   30/24/27/-2/…./…/…/..       24 NE   AERO 23 NE   RMY 24
02/20   32/19/26/-3/T/T/…/..            32 NW   AERO 35 NW   RMY 38

02/21 The low since midnight is 15F, the daily normal low is 20F

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 21
HIGH 70F IN 2018
LOW -6F IN 1950
PRECIP 2.42 INCHES IN 1898
SNOWFALL 9.0 INCHES IN 1929
PEAK GUST 72 MPH WNW IN 1967

RECORDS FOR FEBRUARY 22
HIGH 63F IN 1997
LOW -1F IN 1918
PRECIP 1.38 INCHES IN 1900
SNOWFALL 8.0 INCHES IN 1893
PEAK GUST 74 MPH S IN 1974

TODAY’S REPORT PREPARED BY: Benjamin Turner

Category: Daily Discussions

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