Saturday, May 4, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, MAY 4, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

FOGGY MORNING WITH INTERMITTENT SHOWERS AND INCREASING
VISIBILITY IN THE AFTERNOON….

This morning started with 1/8th mile visibility that
increased to a mile at 10 A.M. EST, and finally 40
miles by the 1 o’clock P.M. EST observation. Intermittent
showers were experienced at the observatory, with a total
rainfall amount of 0.12 inches in the past 24 hours. Fog
was present all morning, and lifted at noon, allowing for
the large increase in visibility between 10 and 1. Our high
so far today is 52F, 11 degrees below our normal daily
maximum temperature of 63F.

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 (1885-2019):

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 (1885-2019):

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: Fog
Temperature: 46F; Dew Point: 46F; Wind: NE at 3 kts
Sea-level pressure: 29.92 ins. Hg, falling then rising
Visibility: 1/8 mile, fog
6-hr Max temp: 51F
6-hr Min temp: 46F
24-hr Precip: 0.10 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 W3 X 1/8F 131/46/46/0506/992/ 8//// 53002 70010
10051 20046

10 A.M.
Weather: Overcast stratus, fog
Temperature: 48F; Dew Point: 48F; Wind: ENE at 5 kts
Wind: light
Sea-level pressure: 29.92 ins. Hg, rising then falling
Visibility: 1 mile, fog
3-hr Precip: 0.02 ins.
BHO SA 1455 E005 OVC 1 132/49/49/0605/992/ FOG WND LGT/ 8/6//
50001 6002/

1 P.M.
Weather: Overcast altostratus, scattered stratus
Temperature: 52F; Dew Point: 48F; Wind: ENE at 6 kts
Sea-level pressure: 29.90 ins. Hg, falling then more quickly
Visibility: 40 miles, distant haze in all directions
6-hr Max temp: 52F
6-hr Min temp: 46F
6-hr Precip: 0.00 ins.
BHO SA 1755 E070 OVC 036 SCT 40 126/52/48/0606/990/ FEW AC
S-N DSNT HZ ALQDS 8/61/ 58006 6002/ 10052 20046

SUMMARY FOR FRIDAY, MAY 3, 2019

TEMPERATURE (DEGREES F)
MAX…..60   NORMAL…..63
MIN…..43   NORMAL…..44
MEAN….52   NORMAL…..53

DEPARTURE FROM 30-YEAR NORMAL……………………-1
TOTAL DEPARTURE FOR THE MONTH…………………..-15 [-5.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..13   DEPARTURE………+1
TOTAL HEATING UNITS FOR THE MONTH…………..51   DEPARTURE………14
TOTAL HEATING UNITS FOR THE SEASON………..5952   DEPARTURE…….-120
TOTAL HEATING UNITS LAST SEASON TO DATE……5706   DIFFERENCE……+246

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..23 S  AT 3:16 P.M.
AERO…………………….23 S  AT 3:25 P.M.
ASOS…………………….22 SW AT 3:16 P.M.
DAVIS……………………29 S  AT 3:16 P.M.  RMY 22
FASTEST MILE FOR YESTERDAY………………….17 S  AT 3:22 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 S  AT 3:16 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………17 S  AT 5:04 P.M.
AVERAGE WIND SPEED AND DIRECTION……………5.8 SSE
ASOS……………………5.8
DAVIS…………………..6.3 SSE [158 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.10  DEPARTURE…….-0.03
ASOS…………..0.10
TOTAL PRECIPITATION FOR THE MONTH……….0.12  DEPARTURE…….-0.25
ASOS…………..0.12
TOTAL PRECIPITATION FOR THE YEAR……….21.30  DEPARTURE…….+2.38
ASOS………….21.33

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 Low temp since midnight is 46F; normal low is 44F

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

RECORDS FOR MAY 4
HIGH 90F IN 2001
LOW 27F IN 1911 (RECORD FOR MAY)
PRECIP 1.92 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966

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

TODAY’S REPORT PREPARED BY: Samantha Richard