Friday, July 9, 2021

| July 9, 2021 | Reply

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

FRIDAY, JULY 9, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0416E
SUNSET:  1922E

HEAVY RAINS RETURN AS TROPICAL STORM ELSA GLIDES THROUGH…

Tropical Storm Elsa is making a pass approximately 40 miles to our
southeast delivering torrential rain and some gusty winds. So far,
we have logged 2.91 inches of rain through 1 PM. 2.67 inches of that
fell between 7a-1p!. We are now currently sitting at 2nd place for
most rainfall for this date. And with the day’s precipitation, we
have graduated to 5th wettest July on record at 8.66 inches. 

Winds have veered to the northwest with escalating speeds. A peak
gust of 36 MPH was recorded around 1:20 PM. Rainfall has been more
of the headline here locally, than the wind.

Temperatures are on the cool side, but the dew points are near
70F – indicative of tropical moisture being enveloped into the
storm.

Visibility continues to be poor. We’ve only been able to see
1/4 mile at best.

Now,here’s some more context for the tropical rain today including the list
of most rainfall on July 9th and the list of wettest calendar days
in July.  Only one other day on these lists appears to have been
from a tropical cyclone.

BHO Highest July 9 Precipitation, inches (1885-2021):
1) 3.74 on July 9, 1921
2) 1.37 on July 9, 1964
3) 1.17 on July 9, 1962
4) 1.10 on July 9, 1895
5) 0.92 on July 9, 1930

BHO Highest July Calendar Day Precipitation, inches (1885-2021):
1) 4.46 on July 1, 1915
2) 4.01 on July 27, 1979
3) 3.74 on July 9, 1921
4) 3.54 on July 13, 1996 [T.S. Bertha]
5) 3.32 on July 28, 1911
6) 3.14 on July 13, 1898
7) 2.92 on July 27, 1988

~via BHO Chief Scientist Mike Iacono

The high so far today is 70F, 12 degrees below the daily average
of 82F. The low so far today is 60F, 4 degrees below the daily
average of 64F.
———————————————–
PRELIMINARY STATS FOR JUNE 2021

TEMPERATURE, Deg. F
Avg. Max. 80.9 [+5.9]
Avg. Min. 60.4 [+3.3]
Mean      70.7 [+4.6]
24-hour corrected mean: 70.0
Max. for month: 95F on the 29th
Min. for month: 50F on the 1st

HEATING DEGREE DAYS
Total heating units:     19 [-54]
Total for the season:  5597 [-725]
Total for last season: 5852

COOLING DEGREE DAYS
Total cooling units:     197 [+92]
Total for the season:    226 [+97]
Total for last season:   184

PRECIPITATION, Inches
Total: 2.72 [-1.59]
Greatest in 24 hrs: 0.68 inches on the 22nd

WIND, mph
Avg. uncorrected wind speed: 10.4 mph
Avg. corrected wind speed:   10.9 mph
Prevailing wind direction:   SSW [22%]
Peak gust and direction:     51 NW on the 30th

SUNSHINE:
Campbell-Stokes card minutes: 16230 minutes of a possible 26376 or 62%
Astronomical total minutes: 16866 minutes of a possible 27415 or 62%


Today’s Observations:

7 A.M.
Weather: Light Rain, Fog (Sky Obscured, Vertical Visibility 200 ft)
Temperature: 68F; Dew Point: 68F; Relative Humidity: 100%
Wind: ESE @ 14G20kts
Sea-level pressure: 29.93 in. Hg; Falling, then falling more slowly
Visibility: 1/16 mile
6-hr Max temp: 68F
6-hr Min temp: 60F
24-hr Precip: 0.24 ins.
BHO SA 1155 X W2 1/16R-F 136/68/68/1114G20/993/ 8//// 56018 70024 10068 20060

10 A.M.
Weather: Heavy Rain, Fog (Sky Obscured, Vertical Visibility 300 ft)
Temperature: 67F; Dew Point: 67F; Relative Humidity: 100%
Wind: ESE @ 13G18 kts
Sea-level pressure: 29.79 in Hg; Falling, then falling more rapidly-
Pressure Falling Rapidly
Visibility: 1/2 mile
3-hr Precip: 1.14 ins.
BHO SA 1455 X W3 1/2R+F 088/67/67/1113G18/979/ PRESFR/ 8//// 58048 6114/


1 P.M.
Weather: Light Rain, Fog (Sky Obscured, Vertical Visibility 300 ft)
Temperature: 68F, Dew point: 68F; Relative Humidity: 100%
Wind: NNW @ 14G21 kts
Sea-level pressure: 29.59 in Hg; Falling, then falling more slowly
Visibility: 1/8 miles
6-hr Max temp: 70F
6-hr Min temp: 65F
6-hr Precip: 2.67 ins.
BHO SA 1755 X W3 1/8R-F 022/68/68/3414G21/959/ 8//// 56066 6267/ 10070 20065


SUMMARY FOR THURSDAY, JULY 8, 2021

TEMPERATURE (DEGREES F)
MAX…….67     NORMAL…..81
MIN…….59     NORMAL…..63
MEAN……63     NORMAL…..72

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….-9
TOTAL DEPARTURE FOR THE MONTH…………………-45 [-5.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY…………….2  DEPARTURE……..+2
TOTAL HEATING UNITS FOR THE MONTH……………23  DEPARTURE…….+21
TOTAL HEATING UNITS FOR THE SEASON…………..23  DEPARTURE…….+21
TOTAL HEATING UNITS LAST SEASON TO DATE……….0  DEPARTURE…….+23

COOLING DEGREE DAYS (SEASON: JAN 2021 THRU DEC 2021)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE…….-8
TOTAL COOLING UNITS FOR THE MONTH……………32  DEPARTURE……-25
TOTAL COOLING UNITS FOR THE SEASON………….258  DEPARTURE……+62
TOTAL COOLING UNITS LAST SEASON TO DATE……..228  DEPARTURE……+30

PEAK WIND GUST (MPH):
                     420C/Official…………..46 W   @ 2:57 A.M.
                     VECTOR #1………………50 W   @ 3:02 A.M.
                     RMY……………………51     @ 3:03 A.M.
                     MERLIN…………………N/A
                     AEROVANE (south tower)…..46 W   @ 3:03 A.M.
                     VECTOR #2 (south tower)….47     @ 3:01 A.M.
                     DAVIS #2 (south tower)…..46 WSW @ 3:04 A.M.
                     ASOS………..OUT OF SERVICE D/T RENOVATIONS
                     DAVIS #1…….DEFECTIVE D/T LIGHTNING STRIKE

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………34 W   @ 3:04 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..35     @ 3:03 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..35 W   @ 3:03 A.M
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..34     @ 3:03 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………35 W   @ 3:04 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE…….OUT OF SERVICE D/T RENOVATIONS MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…DEFECTIVE D/T LIGHTNING STRIKE

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL……9.8 NE [236 total miles]
                     VECTOR #1…………….10.1
                     DAVIS #2……………..N/A
                     RMY………………….9.7 E
                     ASOS…………………OUT OF SERVICE D/T RENOVATIONS
                     DAVIS #1……………..DEFECTIVE D/T LIGHTNING STRIKE

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.24  DEPARTURE….+0.13
TOTAL PRECIPITATION FOR THE MONTH………….5.99  DEPARTURE….+5.12
TOTAL PRECIPITATION FOR THE YEAR………….29.37  DEPARTURE….+1.53
     


PRELIMINARY CLIMATE SUMMARY FOR JUNE CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

06/01   74/50/62/0/0.00/425/47            20 WSW  AERO 24 WSW  RMY 22
06/02   80/55/68/+6/0.00/553/61           28 S    AERO 25 S    RMY 28
06/03   73/56/65/+3/0.01/073/08           29 SSW  AERO 29 SSW  RMY 29
06/04   77/61/69/+6/0.02/054/06           23 SW   AERO 25 WSW  RMY 25 TSTM
06/05   87/60/74/+11/0.00/801/88          32 SSW  AERO 37 SSW  RMY 35
06/06   91/69/80/+17/0.00/819/90          30 WSW  AERO 31 WSW  RMY 32
06/07   92/69/81/+17/0.00/838/92          31 SSW  AERO 35 SSW  RMY 34
06/08   92/69/81/+17/0.06/456/50          24 WSW  AERO 25 WSW  RMY 27 TSTM
06/09   88/70/79/+15/0.02/530/58          21 N    AERO 23 NNW  RMY 23
06/10   70/53/62/-3/0.00/795/87           28 NE   AERO 28 NE   RMY 28
06/11   70/51/61/-4/0.13/411/45           21 SSE  AERO 22 SSE  RMY 22
06/12   72/53/63/-2/0.43/430/47           20 WSW  AERO 18 WSW  RMY 20
06/13   82/56/69/+4/0.00/860/94           26 SSW  AERO 29 SSW  RMY 29
06/14   65/56/61/-5/0.63/027/03           28 S    AERO 30 SSE  RMY 29
06/15   77/61/69/+3/T/357/39              18 NE   AERO 20 NE   RMY 18 TSTM
06/16   73/56/65/-1/0.00/769/84           27 NNW  AERO 31 NNW  RMY 27
06/17   77/52/65/-2/0.00/880/96           21 WNW  AERO 21 NW   RMY 23
06/18   82/56/69/+2/T/789/86              26 WSW  AERO 28 WSW  RMY 30
06/19   86/63/75/+8/0.09/504/55           30 SW   AERO 32 SW   RMY 32
06/20   85/63/74/+6/0.00/816/89           24 S    AERO 25 SSW  RMY 25
06/21   83/65/74/+6/0.00/514/56           37 SSW  AERO 39 SSW  RMY 39
06/22   84/58/71/+3/0.68/229/25           30 NW   AERO 31 NW   RMY 31 TSTM
06/23   73/52/63/-5/0.00/807/88           25 NW   AERO 24 NW   RMY 26
06/24   76/58/67/-2/T/899/98              25 SE   AERO 24 SE   RMY 25
06/25   71/57/64/-5/0.11/046/05           23 S    AERO 23 S    RMY 23
06/26   81/61/71/+2/0.00/376/41           36 SSW  AERO 37 SSW  RMY 38
06/27   85/70/78/+9/0.00/476/52           38 SW   AERO 39 SW   RMY 42
06/28   93/70/82/+12/0.00/851/93          28 SW   AERO 28 SW   RMY 28
06/29   95/73/84/+14/T/750/82             26 W    AERO 30 W    RMY 27 TSTM
06/30   94/69/82/+12/0.54/731/80          51 NW   AERO 53 NW   RMY 56 TSTM

RECORDS FOR JUNE:
JUNE 7: Record high minimum temperature of 69F,
        Surpasses previous record of 66F set in 1922 and 1953

JUNE 29: Record high maximum temperature of 95F,
        Surpasses previous record of 94F set in 1933

JUNE 29: Record high minimum temperature of 73F,
        Surpasses previous record of 71F set in 1999

JUNE 30: Record high maximum temperature of 94F,
        Ties previous record of 94F set in 1964


PRELIMINARY CLIMATE SUMMARY FOR JULY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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


07/01   80/65/73/+2/0.74/…/..           22 W   AERO 20 WSW  RMY 21
07/02   65/55/60/-11/1.49/…/..          37 NE  AERO 36 NE   RMY 39
07/03   56/54/55/-17/1.98/…/..          41 NE  AERO 44 NE   RMY 45
07/04   66/54/60/-12/0.16/…/..          26 ENE AERO 23 ENE  RMY 26
07/05   74/53/64/-8/0.01/…/..           26 SSW AERO 28 SSW  RMY 27
07/06   87/66/77/+5/0.24/…/..           37 W   AERO 48 W    RMY 38 TSTM
07/07   88/88/77/+5/…/…/..            63 NW  AERO 75 NW   RMY 70 TSTM
07/08   67/59/63/-9/…/…/..            46 W   AERO 46 W    RMY 51  

07/09   The low since midnight is 60F, the daily normal low is 64F

RECORDS FOR JULY:
JULY 2: Record daily precipitation of 1.49″,
        Surpasses previous record of 1.42″ set in 1986

JULY 3: Record daily precipitation of 1.98″,
        Surpasses previous record of 1.36″ set in 1985

JULY 7: Record peak wind gust of 63 MPH,
        Surpasses previous record of 55 MPH set in 1989


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

RECORDS FOR JULY 9
HIGH 98F IN 1912
LOW 47F IN 1909
PRECIP 3.74 INS IN 1921
WIND 46 MPH NW IN 1992

RECORDS FOR JULY 10
HIGH 99F IN 1911
LOW 46F IN 1890
PRECIP 1.95 INS IN 2015
WIND 75 MPH W IN 1985

TODAY’S REPORT PREPARED BY: Andrew Swanson

Category: Daily Discussions

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