Friday, March 19, 2021

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

FRIDAY, MARCH 19, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0549E
SUNSET: 1756E

NO SNOW, BUT HEALTHY RAINFALL TO FINISH OUT THE LAST DAY
OF ASTRONOMICAL WINTER…

Overnight rainfall amounted to a beneficial 0.80 inches.
Despite this measurement, we continue a monthly deficit
which stands now at -2.19 inches with the annual at -2.61
inches.

The rainfall was associated with an area of low pressure
that passed to our south. While a few computer models hinted
at some snowfall, we did not observe anything measurable.
Most of the precipitation had exited before the snow really had
a chance to get going – indicating that the cold air infiltrated
the atmosphere a little too late!

What did work out, however, were the temperatures. High
pressure began building into the region late yesterday and
continues to do so today. The barometer rose 4 millibars
in 3hrs – from 4am to 7am!. Air temperatures are responding
to below normal readings as the high so far is just 37F.
Skies are mostly clear with great visibility.

FYI – Astronomical Spring begins tomorrow Saturday, March 20th,
at 4:37 AM EST! The sun angle will have risen 23.4 degrees
since its lowest point at 24.3 degrees above the horizon at
the winter solstice.

The high so far today is 37F, which is 8 degrees below the
normal high of 45F. The low since midnight is 26F, which
is 1 degree below the daily normal low of 27F.

Today’s Observations:
7 A.M.
Weather: Scattered Altocumulus/Altostratus (few cirrus NW,
line of Altocumulus/Altostratus E-SSW)
Temperature: 27F; Dew Point: 10F; Relative Humidity: 49%
Wind: NNW @ 15G26 kts
Sea-level pressure: 30.04 in Hg; Rising, then rising more slowly
Visibility: 75 miles
6-hr Max temp: 34F
6-hr Min temp: 27F
24-hr Precip: 0.80 ins.
24-hr Snow: Trace
Snow Depth: 0 ins.
BHO SA 1155 140 SCT 75 174/27/10/3415G26/004/ FEW CI NW
LINE AC/AS E-SSW/ 8/031/ 51040 70080 10034 20027

10 A.M.
Weather: Clear (few cirrus all quadrants)
Temperature: 32F; Dew Point: 36F; Relative Humidity: 34%
Wind: N @ 15G23 kts
Sea-level pressure: 30.14 in Hg; Rising, then rising more slowly
Visibility: 75 miles
3-hr Precip: 0.00 ins
3-hr Snow: 0.0 ins.
BHO SA 1455 CLR 75 208/32/6/3615G23/014/ FEW CI ALQDS/ 8/001 51034

1 P.M.
Weather: Scattered Cirrus
Temperature: 36F, Dew point: 6F; Relative Humidity: 28%
Wind: NNW @ 16G22 kts
Sea-level pressure: 30.19 in Hg; Rising, then rising more slowly
Visibility: 75 miles
6-hr Max temp: 37F
6-hr Min temp: 26F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 250 SCT 75 222/36/6/3316G22/019/ 8/001 51014 10037
20026

SUMMARY FOR THURSDAY, MARCH 18, 2021

TEMPERATURE (DEGREES F)
MAX…….46 NORMAL…..45
MIN…….34 NORMAL…..27
MEAN……40 NORMAL…..36

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……. +4
TOTAL DEPARTURE FOR THE MONTH………………. +1 [-0.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………25 DEPARTURE…… -4
TOTAL HEATING UNITS FOR THE MONTH…………..568 DEPARTURE…… -1
TOTAL HEATING UNITS FOR THE SEASON…………4613 DEPARTURE…..-524
TOTAL HEATING UNITS LAST SEASON TO DATE…….4554 DEPARTURE……+59

PEAK WIND GUST (MPH):
420C/Official…………..38 NE @ 10:38 P.M.
AEROVANE (south tower)…..40 NE @ 10:38 P.M.
ASOS…………………..38 NE @ 10:38 P.M.
DAVIS #1……………….38 NE @ 10:38 P.M.
DAVIS #2 (south tower)…..39 NE @ 10:37 P.M.
RMY……………………42 @ 10:37 P.M.
VECTOR…………………47 @ 10:37 P.M.
MERLIN…………………40

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………25 NE @ 10:39 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….24 NNE @ 10:38 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………25 NE @ 10:39 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………25 NE @ 10:50 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..24 ENE @ 10:37 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..24 @ 10:36 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……11.9 SW [285 total miles] ASOS…………………11.3
DAVIS #1……………..11.9 WNW
DAVIS #2……………..12.2 WNW
RMY………………….11.4 WNW
VECTOR……………….11.9

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.80 DEPARTURE….+0.61
ASOS………….0.81
TOTAL PRECIPITATION FOR THE MONTH………….0.94 DEPARTURE….-2.19
ASOS………….0.98
TOTAL PRECIPITATION FOR THE YEAR…………..8.94 DEPARTURE….-2.61
ASOS…………9.24

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M……. TRACE DEPARTURE…. -0.4
TOTAL SNOWFALL FOR THE MONTH……………… 0.2 DEPARTURE…. -8.4
TOTAL SNOWFALL FOR THE SEASON……………..72.6 DEPARTURE….+17.5

PRELIMINARY CLIMATE SUMMARY FOR MARCH 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

03/01 42/24/33/+2/0.13/T/020/03 69 WNW AERO 78 WNW RMY 78
03/02 27/10/19/-12/T/0.1/679/100 63 WNW AERO 71 WNW RMY 69
03/03 45/19/32/0/0.00/0.0/375/55 30 W AERO 30 W RMY 34
03/04 38/22/30/-2/0.00/0.0/520/76 46 NW AERO 51 NW RMY 53
03/05 31/18/25/-7/0.00/0.0/549/80 39 WNW AERO 44 NW RMY 45
03/06 33/15/24/-8/0.00/0.0/675/98 28 WNW AERO 29 WNW RMY 30
03/07 35/15/25/-8/0.00/0.0/686/99 21 NW AERO 22 NW RMY 23
03/08 38/19/29/-4/T/T/389/56 20 NW AERO 20 NW RMY 21
03/09 56/30/43/+10/T/T/…/.. 32 WNW AERO 35 WNW RMY 37
03/10 54/32/43/+10/0.00/0.0/…/.. 29 SSW AERO 29 SSW RMY 31
03/11 71/35/53/+19/0.00/0.0/…/.. 41 SSW AERO 43 SSW RMY 46
03/12 62/42/52/+18/0.00/0.0/…/.. 52 WNW AERO 59 WNW RMY 57
03/13 46/27/37/+3/0.00/0.0/…/.. 53 WNW AERO 59 WNW RMY 57
03/14 45/19/32/-3/0.01/0.1/…/.. 51 WNW AERO 58 NW RMY 58
03/15 27/12/20/-15/0.00/0.0/…/.. 48 NW AERO 47 NW RMY 54
03/16 37/13/25/-10/0.00/0.0/…/.. 22 NNW AERO 22 NNW RMY 23
03/17 52/27/40/+4/0.00/0.0/…/.. 28 S AERO 25 S RMY 29
03/18 46/34/40/+4/0.80/T/…/.. 38 NE AERO 40 NE RMY 42