Sunday, May 5, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 5, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

FOG LIFTS IN THE MORNING, AND CLOUDY SKIES, BETTER VISIBILITY
AND DECREASING HUMIDITY PERSIST THROUGH THE LATER MORNING
AND EARLY AFTERNOON….

At 7 AM today, visibility was limited to just
one mile due to fog in the area. Shortly after, the
fog began to lift, and visibility increased to 40
miles by the 10 AM observation. By 1 PM,
visibility was decent at 70 miles. Overcast conditions
have persisted, with no breaks in overcast observed
so far. Our high temperature so far today has been 50F,
which is 13 degrees below our normal daily maximum
temperature of 63F. 0.03 inches of precipitation have
been measured in the past 24 hours before 1 PM.

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: N/A

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: Light drizzle, overcast stratus
Temperature: 46F; Dew Point: 46F; Wind: NE at 7 kts
Sea-level pressure: 29.91 ins. Hg, falling then rising
Visibility: 1 mile, fog
6-hr Max temp: 49F
6-hr Min temp: 45F
24-hr Precip: 0.04 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 E005 OVC 1F 130/46/46/0507/991/ L-CTD FOG/
8/6// 53009 70004 10049 20045

10 A.M.
Weather: Overcast altostratus, few cumulus in all
directions
Temperature: 47F; Dew Point: 45F; Wind: NE at 7 kts
Sea-level pressure: 29.93 ins. Hg, rising then steady
Visibility: 40 miles, distant haze in all directions
3-hr Precip: 0.02 ins.
BHO SA 1455 E120 OVC 40 136/47/45/0507/993/ FEW CU
ALQDS DSNT HZ ALQDS/ 8/11/ 51006 6002/

1 P.M.
Weather: Overcast stratus, few cumulus in all directions
Temperature: 49F; Dew Point: 46F; Wind: NE at 7 kts
Sea-level pressure: 29.92 ins. Hg, rising then falling
Visibility: 70 miles, distant haze in all directions
6-hr Max temp: 50F
6-hr Min temp: 46F
6-hr Precip: 0.02 ins.
BHO SA 1755 E050 OVC 70 132/49/46/0507/992/ FEW CU ALQDS
DSNT HZ ALQDS/ 8/6// 58004 6002/ 10050 20046

SUMMARY FOR SATURDAY, MAY 4, 2019

TEMPERATURE (DEGREES F)
MAX…..54   NORMAL…..63
MIN…..46   NORMAL…..44
MEAN….50   NORMAL…..54

DEPARTURE FROM 30-YEAR NORMAL……………………-4
TOTAL DEPARTURE FOR THE MONTH…………………..-19 [-5.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..15   DEPARTURE………+3
TOTAL HEATING UNITS FOR THE MONTH…………..66   DEPARTURE……..+18
TOTAL HEATING UNITS FOR THE SEASON………..5967   DEPARTURE…….-116
TOTAL HEATING UNITS LAST SEASON TO DATE……5706   DIFFERENCE……+281

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..14 ENE AT 4:50 A.M.
AERO…………………….16 ENE AT 5:50 A.M.
ASOS…………………….15 ENE AT 5:03 A.M.
DAVIS……………………15 ENE AT 4:51 A.M.  RMY N/A
FASTEST MILE FOR YESTERDAY………………….12 ENE AT 4:42 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….13 ENE AT 5:49 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………12 ENE AT 5:04 A.M.
AVERAGE WIND SPEED AND DIRECTION……………4.8 ENE
ASOS……………………5.7
DAVIS…………………..5.5 E [82 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.04  DEPARTURE…….-0.09
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….0.16  DEPARTURE…….-0.33
ASOS…………..0.13
TOTAL PRECIPITATION FOR THE YEAR……….21.34  DEPARTURE…….+2.30
ASOS………….21.34

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/…/..           46 W   AERO 44 W   RMY 44
04/17 62/36/49/+2/0.00/0.0/…/..           26 ESE AERO 25 S   RMY 28
04/18 63/39/51/+3/0.00/0.0/…/..           44 S   AERO 44 S   RMY 50
04/19 71/58/65/+17/…./0.0/…/..          47 SSW AERO 51 SSW RMY 52
04/20 68/60/64/+15/…./0.0/…/..          50 SSW AERO 54 SSW RMY 52
04/21 68/51/60/+11/…./0.0/…/..          35 S   AERO 35 S   RMY N/A
04/22 53/45/49/0/…./0.0/…/..            35 NNE AERO 32 NNE RMY 35
04/23 52/44/48/-2/…./0.0/…/..           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 16 ENE RMY N/A

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

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

RECORDS FOR MAY 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976

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

TODAY’S REPORT PREPARED BY: Samantha Richard