Monday, May 6, 2019

| May 6, 2019 | Reply

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 6, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

RAIN AND FOG THIS MORNING LEAD TO A FAIR WEATHER,
SPRING-LIKE DAY IN THE AFTERNOON….

A distant fog earlier this morning broke up by the 10 A.M.
observation, giving us 85 miles of visibility for the rest
of the day. Low stratocumulus this morning has given
way to upper-level cirrostratus, which has interfered
little with incoming sunshine. Wind has remained
northeasterly at an average speed of 15 mph with a max
gust of 25 mph. The high temperature so far today is
57F, 7 degrees cooler than the normal daily maximum of 64F.
The low since midnight is 44F, a degree below the normal
minimum of 45F.

PRELIMINARY STATS FOR APRIL 2019

TEMPERATURE, Deg. F
Avg. Max. 57.2 [+1.5]
Avg. Min. 39.3 [+1.6]
Mean      48.3 [+1.6]
24-hour corrected mean: 48.5
Max. for month: 71F on the 13th, 14th, and 19th
Min. for month: 27F on the 2nd and 5th

HEATING DEGREE DAYS
Total heating units:    496 [-55]
Total for the season:  5901 [-134]
Total for last season: 5693

PRECIPITATION, Inches
Total: 8.14 [+3.59]
Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: Trace [-3.0]
Greatest in 24 hrs: Trace [10th]

WIND, mph
Avg. uncorrected wind speed: 13.2
Avg. corrected wind speed: 13.6
Prevailing wind direction: S at 15%
Peak gust and direction: 54 W on 3rd

SUNSHINE:
Campbell-Stokes card minutes: N/A
Astronomical total minutes:   N/A

BHO Greatest April Precipitation, inches (1886-2019):

1) 10.37 in 1987
2)  9.38 in 2004
3)  8.71 in 1929
4)  8.68 in 2007
5)  8.53 in 1904
6)  8.14 in 2019
7)  7.57 in 1935
7.57 in 1983
9)  7.31 in 1901

The calendar day rainfall on Monday, 4/22, was more than
two and a half inches, which made it one of the wettest
calendar days ever observed in April. The finalized
amount for the day is now available.

BHO Greatest April Calendar Day Precipitation, inches (1886-2019):

1) 3.47 on April 1,  2004
2) 3.18 on April 21, 1991
3) 2.63 on April 16, 2018
4) 2.57 on April 22, 2019
5) 2.51 on April 24, 1898
2.51 on April 13, 2004
6) 2.45 on April 16, 1929
7) 2.41 on April 28, 1904
8) 2.40 on April 10, 1935

Today’s Observations:

7 A.M.
Weather: Overcast stratocumulus
Temperature: 45F; Dew Point: 45F; Wind: NE at 11G16 kts
Sea-level pressure: 29.96 ins. Hg, rising steadily
Visibility: 40 mile, distant fog
6-hr Max temp: 45F
6-hr Min temp: 44F
24-hr Precip: 0.04 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 E20 OVC 40 146/45/45/0411G16/996/ DSNT FG
ALQDS/ 8/6// 70004 53021 10045 20044

10 A.M.
Weather: Broken stratocumulus
Temperature: 52F; Dew Point: 46F; Wind: NE at 9G17 kts
Sea-level pressure: 30.02 ins. Hg, rising steadily
Visibility: 85 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E20 BKN 85 167/52/46/0409G17/002/ 8/060 53021

1 P.M.
Weather: Broken cirrus, few cumulus in all directions
Temperature: 57F; Dew Point: 41F; Wind: NE at 14G21 kts
Sea-level pressure: 30.04 ins. Hg, rising steadily
Visibility: 85 miles
6-hr Max temp: 57F
6-hr Min temp: 45F
6-hr Precip: 0.00 ins.
BHO SA 1755 E250 BKN 85 173/57/41/0514G21/004/ FEW DSNT
CU ALQDS/ 8/102 53006 10057 20045

SUMMARY FOR SUNDAY, MAY 5, 2019

TEMPERATURE (DEGREES F)
MAX…..52   NORMAL…..63
MIN…..44   NORMAL…..45
MEAN….48   NORMAL…..54

DEPARTURE FROM 30-YEAR NORMAL……………………-6
TOTAL DEPARTURE FOR THE MONTH…………………..-25 [-5.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..17   DEPARTURE………+6
TOTAL HEATING UNITS FOR THE MONTH…………..83   DEPARTURE……..+23
TOTAL HEATING UNITS FOR THE SEASON………..5984   DEPARTURE…….-116
TOTAL HEATING UNITS LAST SEASON TO DATE……5707   DIFFERENCE……+277

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..18 NE  AT  4:50 A.M.
AERO…………………….20 NE  AT  3:39 A.M.
ASOS…………………….18 NE  AT 11:40 P.M.
DAVIS……………………17 NE  AT  4:51 A.M.  RMY N/A
FASTEST MILE FOR YESTERDAY………………….13 NE  AT  4:42 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….13 ENE AT 11:41 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………13 NE  AT  4:13 A.M.
AVERAGE WIND SPEED AND DIRECTION……………7.6 NE
ASOS……………………8.2
DAVIS…………………..8.2 ENE [63 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.04  DEPARTURE…….-0.09
ASOS…………..0.04
TOTAL PRECIPITATION FOR THE MONTH……….0.20  DEPARTURE…….-0.42
ASOS…………..0.17
TOTAL PRECIPITATION FOR THE YEAR……….21.38  DEPARTURE…….+2.30
ASOS………….21.38

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M………0.0  DEPARTURE………0.0
TOTAL SNOWFALL FOR THE MONTH……………0.0  DEPARTURE………0.0
TOTAL SNOWFALL FOR THE SEASON………….47.6  DEPARTURE…….-15.1

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 45/29/37/-4/0.00/0.0/748/98           40 WNW AERO 37 W   RMY 42
04/02 50/27/39/-2/…./0.0/605/79           29 S   AERO 25 S   RMY 31
04/03 62/35/49/+7/…./0.0/484/63           54 W   AERO 58 W   RMY 56
04/04 50/34/42/0/…./0.0/717/93            46 W   AERO 41 W   RMY N/A
04/05 47/27/37/-6/…./0.0/341/44           23 SSW AERO 17 SSW RMY 23
04/06 64/32/48/+5/…./0.0/536/69           24 NW  AERO 18 W   RMY 26
04/07 66/41/54/+11/0.00/0.0/320/41          24 S   AERO 18 S   RMY 25
04/08 48/34/41/-3/0.49/0.0/000/00           25 NE  AERO 20 NE  RMY 26
04/09 40/32/36/-8/0.08/0.0/000/00           23 NE  AERO 16 N   RMY 25
04/10 43/30/37/-8/T/T/000/00                32 NW  AERO 26 NW  RMY 36
04/11 51/29/40/-5/0.00/0.0/403/51           23 NW  AERO 18 NW  RMY N/A
04/12 53/38/46/+1/…./0.0/000/00           35 SSW AERO 29 SSW RMY 39
04/13 71/54/63/+17/…./0.0/167/21          38 SSW AERO 32 SSW RMY N/A
04/14 71/51/61/+15/…./0.0/224/28          25 S   AERO 18 S   RMY N/A
04/15 67/40/54/+7/…./0.0/168/21           46 W   AERO 52 W   RMY 50
04/16 58/37/48/+1/0.00/0.0/805/100          46 W   AERO 44 W   RMY 44
04/17 62/36/49/+2/0.00/0.0/807/100          26 ESE AERO 25 S   RMY 28
04/18 63/39/51/+3/0.00/0.0/000/00           44 S   AERO 44 S   RMY 50
04/19 71/58/65/+17/…./0.0/049/06          47 SSW AERO 51 SSW RMY 52
04/20 68/60/64/+15/…./0.0/000/00          50 SSW AERO 54 SSW RMY 52
04/21 68/51/60/+11/…./0.0/123/15          35 S   AERO 35 S   RMY N/A
04/22 53/45/49/0/…./0.0/000/00            35 NNE AERO 32 NNE RMY 35
04/23 52/44/48/-2/…./0.0/041/05           30 NNE AERO 26 NNE RMY N/A
04/24 65/44/55/+5/…./0.0/…/..           29 WNW AERO 29 WNW RMY 30
04/25 61/39/50/0/0.00/0.0/…/..            22 S   AERO 22 S   RMY 21
04/26 53/42/48/-3/…./0.0/…/..           35 ESE AERO 30 W   RMY 33
04/27 54/39/47/-4/…./…/…/..           41 W   AERO 44 W   RMY 47
04/28 51/38/45/-7/0.08/0.0/…/..           28 W   AERO 28 W   RMY N/A
04/29 60/34/47/-5/0.00/0.0/…/..           23 NW  AERO 24 WNW RMY 24
04/30 48/40/44/-8/0.17/0.0/…/..           26 NW  AERO 23 NW  RMY 25

PRELIMINARY CLIMATE SUMMARY FOR MAY 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

05/01 57/40/49/-4/0.00/0.0/…/..           21 S   AERO 21 SSE  RMY 21
05/02 45/41/43/-10/0.02/0.0/…/..          21 NE  AERO 21 SSW  RMY 20
05/03 60/43/52/-1/…./…/…/..           23 S   AERO 23 S    RMY 22
05/04 54/46/50/-4/…./…/…/..           14 ENE AERO 14 ENE  RMY 17
05/05 52/44/48/-6/0.00/0.0/…/..           18 NE  AERO 20 NE   RMY N/A

05/06 Low temp since midnight is 44F; normal low is 45F

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

RECORDS FOR MAY 6
HIGH 90F IN 1930
LOW 29F IN 1891
PRECIP 1.04 INCHES IN 1890
SNOWFALL TRACE IN 1917,1996
PEAK GUST 65 MPH SSE IN 1989

RECORDS FOR MAY 7
HIGH 93F IN 1930
LOW 33F IN 1970
PRECIP 1.19 INCHES IN 2005
SNOWFALL TRACE IN 1967
PEAK GUST 66e MPH WNW IN 1940

TODAY’S REPORT PREPARED BY: Benjamin Turner

Category: Daily Discussions

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