Thursday, August 19, 2021
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
THURSDAY, AUGUST 19, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0456E
SUNSET: 1839E
REMNANTS OF TROPICAL STORM FRED SWINGING THROUGH…
Rainfall associated with what was Tropical Storm Fred arrived
shortly after sunrise. Precipitation was light at the onset,
picking up quite a bit by mid-morning. Our gauge recorded a
total of 0.62 inches by 1 PM…another healthy drink during
what has been one of the wettest summers on record.
With the area of low pressure passing through, the cloud
deck has been predominantly low and very thick. Visibility
through the morning averaged just 1/16 of a mile. As of
mid-afternoon, the sun is poking through with a peak visibility
of 20 miles.
Winds remain out of the south allowing warm moist air to flood
in. Thus, ambient air temperature and dew point are responding.
Both readings have slowly risen throughout the day – beginning
in the upper-60s and weaving their way into the mid-70s. At
1PM, with the Observatory well within the tropical air mass
associated with post-tropical storm Fred passing to the north,
the mercury read 78F with a dew point of 74F!
Peak wind associated with the storm is 34 MPH with a daily
average so far of 14 MPH.
The high so far today is 79F, 1 degree below the daily normal
maximum of 80F. The low so far today is 69F, which is 6 degrees
above the daily normal minimum of 63F.
FROM THE BHO HISTORY BOOKS…
TODAY IS THE 30TH ANNIVERSARY OF THE LANDFALL OF HURRICANE BOB…
The tropical cyclone that became Hurricane Bob first formed over the Bahamas on August 16th, 1991 and briefly reached Category 3 strength as it moved up the East Coast. It made landfall as a Category 2 Hurricane over coastal Rhode Island at midday on August 19th, 1991. The center of the storm passed about 20 miles east of the Observatory by mid-afternoon. At Blue Hill, light rain began late on the 18th, and periods of moderate to heavy rain including two thunderstorms continued until the evening of the 19th. A total of 2.78 inches of rain was measured. Hourly average wind speeds increased quickly by late morning reaching a high of 50 mph in the hour from 1-2 pm EST. The peak gust of 78 mph from the ENE occurred at 1:32 PM EST before the dissipating eye of the storm, which could be seen from Blue Hill, passed off shore. Two additional wind gusts to 77 mph from the NW and WNW occurred later in the afternoon. The minimum sea-level pressure observed at Blue Hill was 28.78 inches at 2:45 pm EST. Hurricane Bob was the last time that a hurricane made a direct landfall in New England.
Today’s Observations:
7 A.M.
Weather: Sky Obscured, Vertical Visibility 200 feet, Light Rain, Fog
Temperature: 71F; Dew Point: 71F; Relative Humidity: 100%
Wind: SSE @ 10G16 kts
Sea-level pressure: 30.08 in. Hg; Falling, then rising
Visibility: 1/16 mile
6-hr Max temp: 71F
6-hr Min temp: 69F
3-hr Precip: 0.05 ins.
24-hr Precip: 0.05 ins.
BHO SA 1155 X W2 1/16R-F 186/71/71/1610G16/008/ 8//// 55009 6005/ 70005 10071 20069
10 A.M.
Weather: Overcast Nimbostratus, Light Rain, Fog
Temperature: 72F; Dew Point: 72F; Relative Humidity: 100%
Wind: SE @ 18G30 kts
Peak Wind: 34 MPH (30 knots) SE @ 9:54 AM
Sea-level pressure: 29.97 in Hg; Falling, then falling more rapidly
Visibility: 1 mile
3-hr Precip: 0.44 ins.
BHO SA 1455 08 OVC 1R-F 150/72/72/1418G30/997/ PK WND 1430/54/ 8/6//
58036 6044/
1 P.M.
Weather: Broken Stratus Fractus
Temperature: 78F, Dew point: 74F; Relative Humidity: 88%
Wind: SSW @ 19G27 kts
Peak Wind: 31 MPH (27 knots) S @ 12:55 PM
Sea-level pressure: 29.93 in Hg; Falling, then falling more rapidly
Visibility: 20 miles, hazy
6-hr Max temp: 79F
6-hr Min temp: 71F
6-hr Precip: 0.57 ins.
BHO SA 1755 10 BKN 20 137/78/74/2019G27/993/ HAZY PK WND 1827/55/ 8/700 58013 6057/ 10079 20071
SUMMARY FOR WEDNESDAY, AUGUST 18, 2021
TEMPERATURE (DEGREES F)
MAX…….86 NORMAL…..80
MIN…….66 NORMAL…..63
MEAN……76 NORMAL…..71
DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………..+5
TOTAL DEPARTURE FOR THE MONTH…………………..14 [+0.6 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON: JUL 2021 THRU JUN 2022)
TOTAL HEATING UNITS FOR YESTERDAY…………….0 DEPARTURE………0
TOTAL HEATING UNITS FOR THE MONTH…………….0 DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE SEASON…………..28 DEPARTURE…….+18
TOTAL HEATING UNITS LAST SEASON TO DATE……….1 DEPARTURE…….+27
COOLING DEGREE DAYS (SEASON: JAN 2021 THRU DEC 2021)
TOTAL COOLING UNITS FOR YESTERDAY……………11 DEPARTURE……..+4
TOTAL COOLING UNITS FOR THE MONTH…………..146 DEPARTURE…….+12
TOTAL COOLING UNITS FOR THE SEASON………….525 DEPARTURE……..+4
TOTAL COOLING UNITS LAST SEASON TO DATE……..683 DEPARTURE……-158
PEAK WIND GUST (MPH):
Official……………….21 SSW @ 5:01 P.M.
AEROVANE (south tower)…..22 SSW @ 6:10 P.M.
VECTOR #2 (south tower)….22 @ 5:01 P.M.
DAVIS #2 (south tower)…..20 SSW @ 5:11 P.M.
ASOS………..OUT OF SERVICE D/T RENOVATIONS
VECTOR #1……OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…….OUT OF SERVICE D/T RENOVATIONS
RMY…………OUT OF SERVICE D/T RENOVATIONS
MERLIN………OUT OF SERVICE D/T RENOVATIONS
FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………17 SSW @ 5:14 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..17 @ 5:02 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………16 SW @ 1:43 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE…….OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE…OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE..OUT OF SERVICE D/T RENOVATIONS
MAXIMUM 2-MINUTE RMY AVERAGE……..OUT OF SERVICE D/T RENOVATIONS
AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……10.3 SSW [248 total miles]
VECTOR #2…………….11.0
DAVIS #2……………..10.6 SW
RMY……………..OUT OF SERVICE D/T RENOVATIONS
ASOS…………….OUT OF SERVICE D/T RENOVATIONS
VECTOR #1………..OUT OF SERVICE D/T RENOVATIONS
DAVIS #1…………OUT OF SERVICE D/T RENOVATIONS
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.05 DEPARTURE….-0.07
TOTAL PRECIPITATION FOR THE MONTH………….2.81 DEPARTURE….+0.47
TOTAL PRECIPITATION FOR THE YEAR………….37.78 DEPARTURE….+5.00
PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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
08/01 77/58/68/-5/T/589/68 23 SSW AERO 24 SSW RMY N/A
08/02 78/61/70/-3/T/821/95 28 WNW AERO 28 WNW RMY N/A
08/03 76/60/68/-5/0.00/302/35 15 N AERO 16 N RMY N/A
08/04 75/61/68/-5/0.71/077/09 21 ESE AERO 21 ESE RMY N/A
08/05 68/61/65/-8/1.68/000/00 28 NE AERO 28 NE RMY N/A
08/06 85/62/74/+1/0.00/727/85 19 S AERO 20 WSW RMY N/A
08/07 88/66/77/+4/0.00/520/61 23 SW AERO 23 SW RMY N/A
08/08 80/67/74/+2/T/128/15 16 SW AERO 16 WNW RMY N/A
08/09 75/64/70/-2/0.25/076/09 22 ENE AERO 21 NE RMY N/A
08/10 78/63/71/-1/0.12/…/.. 19 S AERO 20 S RMY N/A
08/11 89/70/80/+8/0.00/…/.. 29 SSW AERO 28 SSW RMY N/A
08/12 91/71/81/+9/T/…/.. 36 WSW AERO 37 WSW RMY N/A TSTM
08/13 92/73/83/+11/0.00/…/.. 18 WSW AERO 18 WSW RMY N/A
08/14 87/69/78/+6/T/…/.. 25 W AERO 25 NNW RMY N/A
08/15 80/62/71/-1/0.00/…/.. 19 NNW AERO 20 NNW RMY N/A
08/16 78/59/69/-3/0.00/…/.. 15 S AERO 15 S RMY N/A
08/17 82/63/73/1/0.00/…/.. 22 SSW AERO 23 SSW RMY N/A
08/18 86/66/76/+5/0.00/…/.. 21 SSW AERO 22 SSW RMY N/A
08/19 The low since midnight is 69F, the daily normal low is 63F
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)
RECORDS FOR AUGUST 19
HIGH 92F IN 2019
LOW 48F IN 1958
PRECIP 8.07 INCHES IN 1955 [DIANE – RECORD FOR MONTH]
PEAK GUST 78 MPH ENE IN 1991 – HURRICANE BOB
RECORDS FOR AUGUST 20
HIGH 93F IN 1937
LOW 48F IN 1896, 1905, 1949
PRECIP 2.71 INCHES IN 1970
PEAK GUST 47 MPH W IN 1983, 47 SSW IN 2010
TODAY’S REPORT PREPARED BY: Andrew Swanson
