Sunday, May 19, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 19, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

LATE MORNING SHOWERS BRING A DROP IN TEMPERATURES
AND VISIBILITY, LATER CLEARING FOR A WARM AND DRY
EARLY AFTERNOON…

This morning started pretty mildly with temperatures
rising into the 60’s before 10 AM, but dropping between
10 and 11 to about 54F as showers entered the area. So
far today we have received 0.13 inches of rain. Visibility
at 7 this morning was 40 miles, and dropped to 20 miles
to our west by 10 with the entrance of these showers,
but increased to 40 miles again by the 1 o’clock observation.
Our high so far today was 63F, and temperatures continue
to climb into the afternoon. Our low since midnight was
50F.

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) 2.60 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 cirrostratus, few altocumulus S-N
Temperature: 56F; Dew Point: 44F; Wind: SSE at 16G24 kts,
Sea-level pressure: 30.09 ins. Hg, rising then falling
Visibility: 40 miles, distant haze
6-hr Max temp: 56F
6-hr Min temp: 50F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 250 SCT 40 191/56/44/1516G24/009/ FEW AC S-N
DSNT HZ ALQDS/ 8/098 58001 10056 20050

10 A.M.
Weather: Overcast altostratus
Temperature: 63F; Dew Point: 49F; Wind: SSE at 16G27 kts,
Peak gust: 27 knots SSE at 10:48 A.M.
Sea-level pressure: 30.09 ins. Hg, rising then falling
Visibility: 40 miles N-SW, 20 miles SW-N, distant haze
3-hr Precip: 0.00 ins.
BHO SA 1455 E140 OVC 40 191/63/49/1616G27/009/ DSNT HZ ALQDS
VSBY 20 MI SW-N PK WND 1627/48/ 8/01/ 50000

1 P.M.
Weather: Broken altostratus
Temperature: 62F; Dew Point: 50F; Wind: SSE at 21G31 kts
Peak gust: 31 knots SSE at 12:51 P.M.
Sea-level pressure: 30.03 ins. Hg, falling, then more quickly
Visibility: 40 miles, distant haze
6-hr Max temp: 63F
6-hr Min temp: 54F
6-hr Precip: 0.13 ins.
BHO SA 1755 E140 BKN 40 191/62/50/1621G31/009/ DSNT HZ ALQDS
PK WND 1631/51/ 8/01/ 50000 6013/ 10063 20054

SUMMARY FOR SATURDAY, MAY 18, 2019

TEMPERATURE (DEGREES F)
MAX…..72   NORMAL…..67
MIN…..49   NORMAL…..48
MEAN….61   NORMAL…..58

DEPARTURE FROM 30-YEAR NORMAL……………………+3
TOTAL DEPARTURE FOR THE MONTH…………………..-69 [-4.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………4   DEPARTURE………-4
TOTAL HEATING UNITS FOR THE MONTH………….244   DEPARTURE……..+59
TOTAL HEATING UNITS FOR THE SEASON………..6145   DEPARTURE……..-75
TOTAL HEATING UNITS LAST SEASON TO DATE……5802   DIFFERENCE……+343

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..26 SSE AT 8:47 P.M.
AERO…………………….25 SSE AT 8:53 P.M.
ASOS…………………….25 NW  AT 7:20 A.M.
DAVIS……………………27 ESE AT 8:46 P.M.  RMY 29
FASTEST MILE FOR YESTERDAY………………….20 SSE AT 8:52 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….18 SSE AT 8:53 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………20 SE  AT 8:53 P.M.
AVERAGE WIND SPEED AND DIRECTION……………11.1 NW
ASOS……………………10.5
DAVIS…………………..11.4 WSW [243 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE…….-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.51  DEPARTURE…….+0.30
ASOS…………..2.45
TOTAL PRECIPITATION FOR THE YEAR……….23.69  DEPARTURE…….+2.93
ASOS………….23.66

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/-2/0.08/0.0/605/79           29 S   AERO 25 S   RMY 31
04/03 62/35/49/+7/0.36/0.0/484/63           54 W   AERO 58 W   RMY 56
04/04 50/34/42/0/0.00/0.0/717/93            46 W   AERO 41 W   RMY N/A
04/05 47/27/37/-6/0.10/0.0/341/44           23 SSW AERO 17 SSW RMY 23
04/06 64/32/48/+5/0.12/0.0/536/69           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/+1/0.15/0.0/000/00           35 SSW AERO 29 SSW RMY 39
04/13 71/54/63/+17/0.38/0.0/167/21          38 SSW AERO 32 SSW RMY N/A
04/14 71/51/61/+15/0.15/0.0/224/28          25 S   AERO 18 S   RMY N/A
04/15 67/40/54/+7/0.93/0.0/168/21           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/T/0.0/000/00              44 S   AERO 44 S   RMY 50
04/19 71/58/65/+17/0.03/0.0/049/06          47 SSW AERO 51 SSW RMY 52
04/20 68/60/64/+15/0.46/0.0/000/00          50 SSW AERO 54 SSW RMY 52
04/21 68/51/60/+11/0.06/0.0/123/15          35 S   AERO 35 S   RMY N/A
04/22 53/45/49/0/2.60/0.0/000/00            35 NNE AERO 32 NNE RMY 35
04/23 52/44/48/-2/0.42/0.0/041/05           30 NNE AERO 26 NNE RMY N/A
04/24 65/44/55/+5/0.02/0.0/438/53           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/-3/0.84/0.0/000/00           35 ESE AERO 30 W   RMY 33
04/27 54/39/47/-4/0.62/0.0/100/12           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/…./…/…/..           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 52/38/45/-11/…./…/…/..          35 E   AERO M  M    RMY 34
05/14 44/38/41/-16/…./…/…/..          26 NNE AERO M  M    RMY 25
05/15 58/40/49/-8/…./…/…/..           28 NW  AERO M  M    RMY 28
05/16 68/46/57/0/…./…/…/..            17 NW  AERO M  M    RMY 19
05/17 64/49/57/0/…./…/…/..     22 WNW AERO 21 WNW  RMY 25
05/18 72/49/61/+3/…./…/…/..           26 SSE AERO 25 SSE  RMY 29

05/19 Low temp since midnight is 50F; normal low is 49F

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

RECORDS FOR MAY 19
HIGH 91F IN 1962
LOW 34F IN 2002
PRECIP 1.54 INCHES IN 1900
PEAK GUST 58 MPH NW IN 1964

RECORDS FOR MAY 20
HIGH 91F IN 1975,1996
LOW 37F IN 1948, 2002
PRECIP 1.65 INCHES IN 1969
PEAK GUST 57 MPH S IN 1963, WNW IN 1982

TODAY’S REPORT PREPARED BY: Samantha Richard