Thursday, May 9, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MAY 9, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

A COOL AND DRY DAY ATOP GREAT BLUE HILL….

Today we observed fair weather with increasing clouds
in the afternoon. Winds have shifted from NE to ENE,
with a max gust so far today of 20 mph. Visibility
was good today, remaining at 70 miles on average. Clouds
have started to increase following the 1 P.M. observation.
The high temperature so far today is 59F, 5 degrees under the
daily normal maximum of 64F. The low since midnight is 43F,
3 degrees below the normal minimum of 46F.

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: 3.00 ins. on the 22nd-23rd

SNOWFALL, Inches
Total: Trace [-3.0] Greatest in 24 hrs: Trace on the 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: 8238 minutes of possible 23250 or 35%
Astronomical total minutes:   8543 minutes of possible 24086 or 35%

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

BHO Lowest April Sunshine, hours (1886-2019):

1)  82.6 in 1901  [21%] 2) 121.1 in 1987  [31%] 3) 121.7 in 1988  [31%] 4) 131.6 in 1983  [34%] 5) 132.2 in 1921  [34%] 6) 137.3 in 2019  [35%] 7) 138.1 in 1939  [36%] 8) 140.7 in 1955  [36%] 9) 141.1 in 2000  [36%]

Today’s Observations:

7 A.M.
Weather: Scattered altocumulus, scattered cirrostratus,
few stratocumulus S-NW
Temperature: 49F; Dew Point: 41F; Wind: Ne at 7G15 kts
Sea-level pressure: 30.40 ins. Hg, rising steadily
Visibility: 75 miles
6-hr Max temp: 49F
6-hr Min temp: 43F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 110 SCT 250 SCT 75 293/49/41/0507G15/040/
FEW SC S-NW/ 8/435 51008 10049 20043

10 A.M.
Weather: Scattered altocumulus
Temperature: 54F; Dew Point: 33F; Wind: NE at 7G12 kts
Sea-level pressure: 30.40 ins. Hg, falling steadily
Visibility: 70 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 110 SCT 70 290/54/33/0607G12/040/ 8/030
58003

1 P.M.
Weather: Scattered altocumulus, scattered cirrostratus
Temperature: 57F; Dew Point: 30F; Wind: ESE at 7G14 kts
Sea-level pressure: 30.34 ins. Hg, falling steadily
Visibility: 70 miles
6-hr Max temp: 59F
6-hr Min temp: 49F
6-hr Precip: 0.00 ins.
BHO SA 1755 160 SCT 250 SCT 70 275/57/30/1107G14/034/
8/085 56015 10059 20049

SUMMARY FOR WEDNESDAY, MAY 8, 2019

TEMPERATURE (DEGREES F)
MAX…..67   NORMAL…..64
MIN…..48   NORMAL…..45
MEAN….58   NORMAL…..55

DEPARTURE FROM 30-YEAR NORMAL……………………+3
TOTAL DEPARTURE FOR THE MONTH…………………..-23 [-3.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………7   DEPARTURE………-3
TOTAL HEATING UNITS FOR THE MONTH………….112   DEPARTURE……..+19
TOTAL HEATING UNITS FOR THE SEASON………..6013   DEPARTURE…….-114
TOTAL HEATING UNITS LAST SEASON TO DATE……5729   DIFFERENCE……+284

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..20 NE  AT  7:47 A.M.
AERO…………………….20 NE  AT  7:53 A.M.
ASOS…………………….20 ENE AT  7:53 A.M.
DAVIS……………………20 NE  AT  7:53 A.M.  RMY 19
FASTEST MILE FOR YESTERDAY………………….15 NE  AT  7:54 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….15 ENE AT  7:54 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………15 ENE AT  7:54 A.M.
AVERAGE WIND SPEED AND DIRECTION……………7.6 N
ASOS……………………8.3
DAVIS…………………..8.1 N [11 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE…….-0.12
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.32  DEPARTURE…….-0.67
ASOS…………..0.28
TOTAL PRECIPITATION FOR THE YEAR……….21.38  DEPARTURE…….+1.96
ASOS………….21.38

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/…./0.0/438/53           29 WNW AERO 29 WNW RMY 30
04/25 61/39/50/0/0.00/0.0/696/84            22 S   AERO 22 S   RMY 21
04/26 53/42/48/-3/…./0.0/000/00           35 ESE AERO 30 W   RMY 33
04/27 54/39/47/-4/…./0.0/100/12           41 W   AERO 44 W   RMY 47
04/28 51/38/45/-7/0.08/0.0/159/19           28 W   AERO 28 W   RMY N/A
04/29 60/34/47/-5/0.00/0.0/612/73           23 NW  AERO 24 WNW RMY 24
04/30 48/40/44/-8/0.17/0.0/000/00           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 58/44/51/-3/…./0.0/…/..           25 NE  AERO 26 ENE  RMY 24
05/07 72/41/57/+2/0.12/0.0/…/..           30 S   AERO 29 S    RMY 30
05/08 67/48/58/+3/0.00/0.0/…/..           20 NE  AERO 20 NE   RMY 19

05/09 Low temp since midnight is 43F; normal low is 46F

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

RECORDS FOR MAY 9
HIGH 93F IN 2000
LOW 31F IN 1947
PRECIP 2.72 INCHES IN 1954
SNOWFALL 5.0 INS IN 1977 (RECORD FOR MAY)
PEAK GUST 70e MPH NE IN 1977

RECORDS FOR MAY 10
HIGH 93F IN 1896
LOW 29F  IN 1900
PRE 1.85 INS IN 1998
SNOW 2.8 INS 1977 (7.8 INS TOTAL 5/9-5/10 1977)
PEAK GUST 64 MPH S IN 1990

TODAY’S REPORT PREPARED BY: Benjamin Turner