Tuesday, May 7, 2019

| May 7, 2019 | Reply

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 7, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

A WARMER THAN NORMAL DAY TO BREAK THE
CLOUDY STREAK….

Today we observed fair weather with increasing clouds
in the afternoon. Wind has remained southerly, blowing
at an average of 15 mph. Visibility decreased as the
day went on, dropping to 40 miles from 70 miles this
morning. Warm air advection from the south brought
temperatures above seasonal averages. However, the
overnight lows remain at or below normal. The high
temperature so far today is 72F, 8 degrees above
the normal daily maximum of 64F. The low since midnight
is 41F, 4 degrees below the normal minimum of 45F.

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: Trace [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 (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

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: Clear, few cirrostratus in all directions
Temperature: 52F; Dew Point: 40F; Wind: SW at 10G14 kts
Sea-level pressure: 30.16 ins. Hg, rising steadily
Visibility: 70 miles
6-hr Max temp: 52F
6-hr Min temp: 41F
24-hr Precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 CLR 70 212/52/40/2210G14/016/ FEW CS ALQDS/
8/008 53003 10052 20041

10 A.M.
Weather: Broken altocumulus, broken cirrus
Temperature: 65F; Dew Point: 45F; Wind: NE at 16G23 kts
Sea-level pressure: 30.16 ins. Hg, rising steadily
Visibility: 70 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E90 SCT 250 BKN 70 215/65/45/2116G23/016/
8/062 53004

1 P.M.
Weather: Broken altocumulus, broken cirrostratus
Temperature: 71F; Dew Point: 45F; Wind: S at 14G24 kts
Sea-level pressure: 30.13 ins. Hg, falling steadily
Visibility: 40 miles
6-hr Max temp: 72F
6-hr Min temp: 51F
6-hr Precip: 0.00 ins.
BHO SA 1755 E100 BKN 250 BKN 40 203/71/45/1814G24/013/
8/066 58012 10072 20051

SUMMARY FOR MONDAY, MAY 6, 2019

TEMPERATURE (DEGREES F)
MAX…..58   NORMAL…..64
MIN…..44   NORMAL…..45
MEAN….51   NORMAL…..54

DEPARTURE FROM 30-YEAR NORMAL……………………-3
TOTAL DEPARTURE FOR THE MONTH…………………..-28 [-4.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..14   DEPARTURE………+3
TOTAL HEATING UNITS FOR THE MONTH…………..97   DEPARTURE……..+26
TOTAL HEATING UNITS FOR THE SEASON………..5998   DEPARTURE…….-108
TOTAL HEATING UNITS LAST SEASON TO DATE……5715   DIFFERENCE……+283

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..25 NE  AT 12:56 P.M.
AERO…………………….26 ENE AT  1:38 P.M.
ASOS…………………….26 NE  AT  4:26 A.M.
DAVIS……………………25 ENE AT  5:39 A.M.  RMY 24
FASTEST MILE FOR YESTERDAY………………….17 NE  AT 12:55 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 ENE AT  1:08 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………19 ENE AT 12:54 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..10.5 NNE
ASOS…………………..10.8
DAVIS………………….11.1 ENE [66 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……….0.20  DEPARTURE…….-0.54
ASOS…………..0.17
TOTAL PRECIPITATION FOR THE YEAR……….21.38  DEPARTURE…….+2.09
ASOS………….21.38

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/-4/0.00/0.0/726/98           40 WNW AERO 37 W   RMY 42
04/02 50/27/39/-2/…./0.0/582/79           29 S   AERO 25 S   RMY 31
04/03 62/35/49/+7/…./0.0/468/63           54 W   AERO 58 W   RMY 56
04/04 50/34/42/0/…./0.0/690/93            46 W   AERO 41 W   RMY N/A
04/05 47/27/37/-6/…./0.0/324/44           23 SSW AERO 17 SSW RMY 23
04/06 64/32/48/+5/…./0.0/516/69           24 NW  AERO 18 W   RMY 26
04/07 66/41/54/+11/0.00/0.0/324/41          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/-5/0.00/0.0/390/51           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/…./0.0/162/21          38 SSW AERO 32 SSW RMY N/A
04/14 71/51/61/+15/…./0.0/216/28          25 S   AERO 18 S   RMY N/A
04/15 67/40/54/+7/…./0.0/162/21           46 W   AERO 52 W   RMY 50
04/16 58/37/48/+1/0.00/0.0/774/100          46 W   AERO 44 W   RMY 44
04/17 62/36/49/+2/0.00/0.0/780/100          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/…./0.0/048/06          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/…./0.0/120/15          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/…./0.0/036/05           30 NNE AERO 26 NNE RMY N/A
04/24 65/44/55/+5/…./0.0/420/53           29 WNW AERO 29 WNW RMY 30
04/25 61/39/50/0/0.00/0.0/678/84            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/…./0.0/096/12           41 W   AERO 44 W   RMY 47
04/28 51/38/45/-7/0.08/0.0/150/19           28 W   AERO 28 W   RMY N/A
04/29 60/34/47/-5/0.00/0.0/594/73           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 Low temp since midnight is 41F; normal low is 45F

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

RECORDS FOR MAY 7
HIGH 93F IN 1930
LOW 33F IN 1970
PRECIP 1.19 INCHES IN 2005
SNOWFALL TRACE IN 1967
PEAK GUST 66e MPH WNW IN 1940

RECORDS FOR MAY 8
HIGH 89F IN 2000
LOW 29F IN 1956
PRECIP 1.48 INCHES IN 1886
SNOWFALL TRACE IN 1898, 1947
PEAK GUST 68e MPH NNW IN 1943

TODAY’S REPORT PREPARED BY: Benjamin Turner

Category: Daily Discussions

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