Friday, May 10, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 10, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

GLOOMY COUDY DAY, With LIGHT SHOWERS IN THE AFTEROON

Clouds persisted throughout the day moderating the temperature
in the upper 40s to mid-50s. Only seeing a 6 degree temperature
increase mid-day then beginning to cool as shower began in the
late afternoon. Visibility decreased throughout the day, with 20
miles observed at the 1 P.M. with distant fog. The high temperature
so far today is 55F, 9 degrees under the daily normal maximum of 64F.
The low since midnight is 47F, 1 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: Overcast stratus
Temperature: 49F; Dew Point: 48F; Wind: SSE at 9G20 kts
Sea-level pressure: 30.21 ins. Hg, falling, then more rapidly
Visibility: 40 miles
6-hr Max temp: 49F
6-hr Min temp: 47F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 32 OVC 40 233/49/48/1609G20/021/ 8/6// 58011 10049 20047

10 A.M.
Weather: Overcast stratocumulus
Temperature: 53F; Dew Point: 49F; Wind: S at 18G28 kts
Sea-level pressure: 30.18 ins. Hg, falling, then more rapidly
Visibility: 35 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 23 OVC 35 222/53/49/1718G28/018/PK WND 1728/43 8/5//
58031

1 P.M.
Weather: Overcast stratus fractus
Temperature: 53F; Dew Point: 53F; Wind: S at 15G26 kts
Sea-level pressure: 30.11 ins. Hg, falling, then more rapidly
Visibility: 20 miles, distant fog in all directions
6-hr Max temp: 53F
6-hr Min temp: 48F
6-hr Precip: 0.00 ins.
BHO SA 1755 12 OVC 20 199/53/53/1815G26/011/ R- DSNT FG ALQDS PK WND
1827/57 8/7// 58023 10053 20048

SUMMARY FOR THURSDAY, MAY 9, 2019

TEMPERATURE (DEGREES F)
MAX…..60   NORMAL…..64
MIN…..43   NORMAL…..46
MEAN….52   NORMAL…..55

DEPARTURE FROM 30-YEAR NORMAL……………………-3
TOTAL DEPARTURE FOR THE MONTH…………………..-25 [-2.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………13   DEPARTURE………+3
TOTAL HEATING UNITS FOR THE MONTH………….125   DEPARTURE……..+22
TOTAL HEATING UNITS FOR THE SEASON………..6026   DEPARTURE…….-112
TOTAL HEATING UNITS LAST SEASON TO DATE……5733   DIFFERENCE……+293

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..21 SE  AT  5:14 P.M.
AERO…………………….21 E   AT  4:02 P.M.
ASOS…………………….20 ESE AT  3:37 P.M.
DAVIS……………………21 E   AT  3:37 P.M.  RMY 22
FASTEST MILE FOR YESTERDAY………………….15 E   AT  4:36 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….15 S   AT  11:59 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………15 SE  AT  4:538 P.M.
AVERAGE WIND SPEED AND DIRECTION……………9.3 NE
ASOS……………………9.8
DAVIS…………………..9.6 E [91 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE…….-0.11
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.32  DEPARTURE…….-0.78
ASOS…………..0.28
TOTAL PRECIPITATION FOR THE YEAR……….21.50  DEPARTURE…….+1.85
ASOS………….21.49

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 60/43/52/-3/0.00/0.0/…/..     21 SE  AERO 21 E    RMY 22

05/10 Low temp since midnight is 47F; normal low is 46F

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

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

RECORDS FOR MAY 11
HIGH 90F IN 1993
LOW 28F IN 1900
PRE 1.28 INS IN 1957
SNOW 1.0 INS IN 1907 (LATEST MEASURABLE SNOW ON RECORD)
PEAK GUST 75e MPH NW IN 1945

TODAY’S REPORT PREPARED BY: Nicholas Rousseau