Monday, May 13, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 13, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

CHILLY AND OVERCAST WITH TEMPERATURES DROPPING
THROUGHOUT THE DAY….

Yesterday’s rain left 0.68 inches in the gauge
at the 7 A.M. observation. Ice pellets were also
observed following noontime yesterday. Skies have
moved from mostly cloudy to completely overcast by
10 A.M. today, with pressure dropping almost 3 millibars
by the early afternoon. Wind has shifted more easterly
this morning, and has intensified to an average speed
of 25 mph. The highest gust so far today is 35 mph.
The high so far today is 52F, 14 degrees below the
normal maximum of 66F. The low since midnight is
39F, 8 degrees below the normal daily minimum of 47F.

BHO Dates of Latest Frozen Precipitation (1885-2019):
(excluding hail)

1) June 2, 1907 (Trace of sleet)
2) May 26, 1967 (Trace of sleet)
3) May 18, 2002 (Trace of sleet)
4) May 12, 2019 (Trace of sleet)
5) May 11, 1907 (1.0 inch of snow)
May 11, 1945 (Trace of snow)
7) May 10, 1900 (Trace of snow)
May 10, 1945 (Trace of snow)
May 10, 1977 (2.8 inches of snow)
10) May 9, 1977 (5.0 inches of snow)

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: 47.3
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, broken cirrocumulus
Temperature: 48F; Dew Point: 36F; Wind: ENE at 11G20 kts
Sea-level pressure: 29.96 ins. Hg, rising, then more slowly
Visibility: 75 miles
6-hr Max temp: 48F
6-hr Min temp: 40F
24-hr Precip: 0.68 ins.
24-hr snowfall: Trace (sleet)
Snow depth: 0 ins.
BHO SA 1155 160 SCT E250 BKN 75 147/48/36/0611G20/996/
8/089 70068 53011 10048 20040

10 A.M.
Weather: Overcast altostratus
Temperature: 50F; Dew Point: 39F; Wind: E at 11G24 kts
Sea-level pressure: 29.97 ins. Hg, rising then steady
Visibility: 75 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E80 OVC 75 149/50/39/0811G24/997/ FEW CU
ALQDS/ 8/12/ 50002

1 P.M.
Weather: Overcast altostratus
Temperature: 47F; Dew Point: 37F; Wind: E at 15G23 kts,
Peak wind: 35 MPH (30 kts) E at 12:48 P.M.
Sea-level pressure: 29.92 ins. Hg, falling, then more rapidly
Visibility: 75 miles
6-hr Max temp: 52F
6-hr Min temp: 47F
6-hr Precip: 0.00 ins.
BHO SA 1755 E80 OVC 75 133/47/37/1015G23/992/ FEW CU ALQDS
PK WND 1030/48/ 8/12/ 58014 10052 20047

SUMMARY FOR SUNDAY, MAY 12, 2019

TEMPERATURE (DEGREES F)
MAX…..50   NORMAL…..65
MIN…..36   NORMAL…..47
MEAN….43   NORMAL…..56

DEPARTURE FROM 30-YEAR NORMAL…………………..-13
TOTAL DEPARTURE FOR THE MONTH…………………..-37 [-3.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..22   DEPARTURE……..+13
TOTAL HEATING UNITS FOR THE MONTH………….164   DEPARTURE……..+31
TOTAL HEATING UNITS FOR THE SEASON………..6065   DEPARTURE…….-102
TOTAL HEATING UNITS LAST SEASON TO DATE……5757   DIFFERENCE……+308

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..30 ENE AT 6:25 A.M.
AERO……………………..M M   AT N/A
ASOS…………………….28 E   AT 6:25 A.M.
DAVIS……………………27 ENE AT 6:18 A.M.  RMY N/A
FASTEST MILE FOR YESTERDAY………………….19 ENE AT 6:40 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….20 E   AT 6:39 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………20 E   AT 6:40 A.M.
AVERAGE WIND SPEED AND DIRECTION……………5.9 NW
ASOS……………………6.5
DAVIS…………………..6.3 ENE [78 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.68  DEPARTURE…….+0.55
ASOS…………..0.67
TOTAL PRECIPITATION FOR THE MONTH……….1.19  DEPARTURE…….-0.28
ASOS…………..1.13
TOTAL PRECIPITATION FOR THE YEAR……….22.37  DEPARTURE…….+2.35
ASOS………….22.34

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 61/46/54/-1/0.16/0.0/…/..           35 S   AERO 37 S    RMY 37
05/11 68/50/59/+3/6/0/…/…/..            26 NW  AERO M  M    RMY N/A
05/12 50/36/43/-13/0.68/T/…/..          30 ENE AERO M  M    RMY N/A

05/13 Low temp since midnight is 39F; normal low is 47F

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

RECORDS FOR MAY 13
HIGH 85F IN 1947
LOW 35F IN 1914, 2005
PRECIP 2.39 INCHES IN 2006
PEAK GUST 49 MPH NNW IN 1965

RECORDS FOR MAY 14
HIGH 85F IN 1961
LOW 33F IN 1895
PRECIP 1.93 INCHES IN 2006
PEAK GUST 53 MPH S IN 2009

TODAY’S REPORT PREPARED BY: Benjamin Turner / Mike Iacono