Friday, April 16, 2021

| April 16, 2021 | Reply

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

FRIDAY, APRIL 16, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0501E
SUNSET:  1827E

CALENDAR SAYS SPRING, YET SCENERY SAYS WINTER…

Record breaking snowfall occurred here on the hill today.
Snow began mixing with rain just before the 7AM observation.
By 7:30AM, the precipitation type was all snow. It came down
moderate at times totaling 3.6 inches before changing back
to light rain by the 1PM observation. This breaks the old
daily record of 2.0 inches set back in 1904 and in 1962.
In fact, today ranks as the 6th Highest Late Season
Snowfall (1885-2021), per our Chief Scientist Mike Iacono:

1) 7.8 on 9-10 May 1977
2) 11.0 on 28-29 April 1987
3) 8.0 on 28 April 1916
4) 4.3 on 18 April 2020
5) 3.7 on 18 April 1965
6) 3.6 on 16 April 2021

The snow was accompanied by anomalously chilly temperatures.
32F was the average during the snowfall dipping to 31F during
heavy bursts. Only a high of 39F was found today which was
set just after midnight. This is good for 17 degrees below
where we should be at 56F.

The storm has brought a total of 1.98 inches of melted 
precipitation so far which puts a noteworthy dent in the
drought department. We are now just 0.51 inches below on
the month, though at -4.33 inches on the year. The weekly
drought monitor has most of MA as abnormally dry, with north
central Massachusetts now in moderate drought territory.

Winds are the other story. Gusts have escalated rapidly after
lunchtime peaking so far at 47 MPH from the NNW.

The high so far today is 39F, this is 17 degrees below the
normal high of 56F. The low since midnight is 31F, which is
7 below the daily normal low of 38F.


Today’s Observations:

7 A.M.
Weather: Overcast Stratus; Light mix of snow, sleet and rain
Temperature: 36F; Dew Point: 36F; Relative Humidity: 100%
Wind: N at 11G33kts
Peak Wind: 38 MPH (33 knots) NNE @ 6:33 AM
Sea-level pressure: 29.54 in Hg, falling, then falling more slowly  
Visibility: 1 mile, fog
6-hr Max temp: 39F
6-hr Min temp: 36F
24-hr Precip: 1.06 ins.
24-hr Snow: Trace
Snow Depth: Trace
BHO SA 1155 E80 OVC 1S-IP-R-F 002/36/36/3511G33/954/ S-B50 IP-B50
R-CTD TOTAL NEW SNW PST 24 HRS TRACE PK WND 0333/33/ 8/6// 56021
70106 10039 20036

10 A.M.
Weather: Sky Obscured, Vertical Visibility 300 feet; Steady Snow & Fog
Temperature: 32F; Dew Point: 32F; Relative Humidity: 100%
Wind: NNW @ 14G24 kts
Sea-level pressure: 29.47 in Hg; falling, then falling more rapidly
Visibility: 1/2 mile, fog
3-hr Precip: 0.52 ins.
3-hr Snow: 2.5 ins.
BHO SA X W3 1/2SF 980/32/32/3314G24/947/ SCTD TOTAL NEW SNW PST
3 HRS 2.5 INS/ 8/// 58022 6052/

1 P.M.
Weather: Sky Obscured, Vertical Visibility 300 feet; Light Rain & Fog
Temperature: 33F, Dew point: 33F; Relative Humidity: 100%
Wind: NNW @ 26G35 kts
Peak Wind: 40 MPH (35 knots) NNW @ 12:50 PM
Sea-level pressure: 29.35 in Hg; falling unsteadily
Visibility: 3/4 mile, fog
6-hr Max temp: 36F
6-hr Min temp: 31F
6-hr Precip: 0.92 ins.
6-hr Snow: 3.6 ins.
Snow Depth: 3 ins.
BHO SA 1755 X W3 3/4R-F 939/33/33/3326G35/935/ R-CTD TOTAL
NEW SNW PST 6 HRS 3.6 INS PK WND 3335/50/ 8//// 4/003 57045
6092/ 10036 20031


SUMMARY FOR THURSDAY, APRIL 15, 2021

TEMPERATURE (DEGREES F)
MAX…….51     NORMAL…..56
MIN…….37     NORMAL…..38
MEAN……44     NORMAL…..47

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……. -3
TOTAL DEPARTURE FOR THE MONTH……………….+43 [+2.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………21  DEPARTURE…… +3
TOTAL HEATING UNITS FOR THE MONTH…………..275  DEPARTURE……-44
TOTAL HEATING UNITS FOR THE SEASON…………5097  DEPARTURE…..-705
TOTAL HEATING UNITS LAST SEASON TO DATE…….5175  DEPARTURE……-78

PEAK WIND GUST (MPH):
                     420C/Official…………..26 ESE @  2:58 P.M.
                     AEROVANE (south tower)…..25 ESE @  9:28 P.M.
                     ASOS…………………..26 E   @  9:18 P.M.
                     DAVIS #1……………….27 ESE @  3:11 P.M.
                     DAVIS #2 (south tower)…..22 ESE @  2:47 P.M.
                     RMY……………………28     @  2:58 P.M.
                     VECTOR…………………28     @  2:58 P.M.
                     MERLIN…………………N/A

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 ESE @  3:13 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….21 ESE @  2:59 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………22 ESE @  2:59 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………20 ESE @  2:59 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..20 SE  @  2:57 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..21     @  2:56 P.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL……10.8 ESE [258 total miles]
                     ASOS…………………10.3
                     DAVIS #1……………..11.3 ESE  
                     DAVIS #2……………..11.1 ESE
                     RMY………………….11.7 ESE
                     VECTOR……………….11.0

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….1.06  DEPARTURE….+0.91
                             ASOS………….1.00
TOTAL PRECIPITATION FOR THE MONTH………….2.00  DEPARTURE….-0.51
                             ASOS………….1.92
TOTAL PRECIPITATION FOR THE YEAR………….12.17  DEPARTURE….-4.33
                              ASOS………..12.43

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………TRACE  DEPARTURE…. -0.1
TOTAL SNOWFALL FOR THE MONTH …………….TRACE  DEPARTURE…..-2.2
TOTAL SNOWFALL FOR THE SEASON……………..72.6  DEPARTURE….+11.2


PRELIMINARY CLIMATE SUMMARY FOR APRIL 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

04/01   56/30/43/+2/0.89/T/000/00        44 NW   AERO 51 NW   RMY 49
04/02   37/24/31/-10/0.00/0.0/614/80     28 NW   AERO 32 NNW  RMY 30
04/03   48/23/36/-6/0.00/0.0/755/98      24 NW   AERO 25 NW   RMY 26
04/04   58/33/46/+4/0.00/0.0/734/95      38 NNW  AERO 41 NNW  RMY 41
04/05   57/41/49/+6/T/T/031/04           41 NNW  AERO 48 NNW  RMY 50
04/06   61/40/51/+8/0.00/0.0/412/53      26 NNW  AERO 25 NNW  RMY 31
04/07   57/41/49/+6/0.00/0.0/391/50      23 ENE  AERO 21 ENE  RMY 22
04/08   59/43/51/+7/0.00/0.0/745/95      22 ENE  AERO 22 ENE  RMY 24
04/09   69/42/56/+12/0.00/0.0/707/90     24 S    AERO  M   M  RMY 26
04/10   75/43/59/+14/0.00/0.0/576/73     26 SSW  AERO 28 SSW  RMY 30
04/11   53/40/47/+2/T/0.0/000/00         33 ENE  AERO 33 ENE  RMY 34
04/12   46/37/42/-3/0.05/0.0/000/00      36 ENE  AERO 37 ENE  RMY 41
04/13   56/37/47/+1/T/0.0/…/..         31 NE   AERO 30 NE   RMY 33
04/14   56/42/49/+3/0.00/0.0/…/..      22 ESE  AERO 23 ESE  RMY 22
04/15   51/37/44/-3/…/0.0/…/..       26 ESE  AERO 25 ESE  RMY 28

04/16   The low since midnight is 31F, the daily normal low is 38F


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

RECORDS FOR APRIL 16
HIGH 89 IN 2012
LOW 23 IN 1943
PRECIP 2.63 IN. IN 2018
SNOWFALL 2.0 IN. IN 1904, 1962 [NEW RECORD: 3.6 IN. IN 2021]
PEAK GUST 73 MPH E IN 2007

RECORDS FOR APRIL 17
HIGH 93 IN 2002
LOW 21 IN 1908
PRECIP 1.68 IN 1954
SNOWFALL 1.0 IN. IN 1899
PEAK GUST 63 MPH ESE IN 2011

TODAY’S REPORT PREPARED BY: Andrew Swanson

Category: Daily Discussions

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