Saturday, April 27, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, APRIL 27, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

THUNDERSTORMS OVERNIGHT BRING MORE HEAVY RAIN TO BLUE HILL…
MOSTLY CLOUDY AND BREEZY TODAY…

A total of 1.45 inches of rainfall was recorded since Friday
morning, with most of that falling during two thunderstorms
last evening. The heaviest hours were between 7 and 8 PM EST
and 11 PM to 2 AM EST this morning; those hours alone brought
about an inch and a quarter of rainfall. Only a trace of rain
fell during a brief rain shower around 10:00 AM EST today.
The sky has been mostly cloudy, with periods of sunshine during
the morning. As the departing storm left the area, drier air
has moved in, dropping the dew point to the upper 20s as of
mid-day. The visibility has improved during the day, rising
to about 70 miles by the 1 PM EST observation. The wind
became much stronger after 7 AM, and has been gusting to
35-40 mph all day. The peak gust has been 37 knots, 43 mph,
from the west at 12:10 PM and 12:27 PM EST.

The rainfall overnight brought the monthly total up to 7.89 inches,
which makes it the sixth wettest April already, with more rain
expected before the end of the month.

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)  7.89 in 2019  (through 1 PM on 4/27)
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 will be reported when 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) 2.51 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: Broken stratocumulus, overcast stratocumulus, few
lower stratocumulus, pressure rising rapidly
Temperature: 44F; Dew Point: 42F; Wind: W at 12G17 kts
Sea-level pressure: 29.33 ins. Hg, rising then more rapidly
Visibility: 50 miles, visibility NW 60, N 25
6-hr Max temp: 54F
6-hr Min temp: 42F
24-hr Precip: 1.45 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 E20 BKN 40 OVC 50 931/44/42/2612G17/933/ FEW LWR SC
VSBY NW 60 N 25 PRESRR/ 8/5// 53039 60/// 70145 10054 20042

10 A.M.
Weather: Light rain shower, broken stratocumulus, overcast
altocumulus, few breaks in overcast SW-N, rain shower began
9:48 AM EST, rain shower overhead-south moving east, rain
shower, WNW-NW moving E
Temperature: 46F; Dew Point: 35F; Wind: WSW at 21G34 kts
Wind: Peak gust 39 mph W at 9:55 A.M. EST
Sea-level pressure: 29.42 ins. Hg, rising then more rapidly
Visibility: 50 miles, visibility WNW-NW 35, SSE-S 20
3-hr Precip: Trace ins.
BHO SA 1455 E35 BKN 45 BKN 75 OVC 50RW- 964/46/35/2521G34/942/
FEW BINOVC SW-N RW- OVHD-S MVNG E RW- WNW-NW MVNG E RW-B48
VSBY WNW-NW 35 SSE-S 20 PK WND 2634/55/ 8/57/ 53033 6000//

1 P.M.
Weather: Scattered stratocumulus, overcast stratocumulus,
breaks in overcast overhead-W-NE
Temperature: 49F; Dew Point: 28F; Wind: W at 20G33 kts,
Wind: Peak gust 43 mph W at 12:12 P.M. EST
Sea-level pressure: 29.44 ins. Hg, rising then more quickly
Visibility: 70 miles
6-hr Max temp: 51F
6-hr Min temp: 44F
6-hr Precip: Trace ins.
6-hr snowfall: 0.0 ins.
BHO SA 1755 50 SCT E70 OVC 70 971/49/28/2620G33/944/ BINOVC
OVHD-W-NE PK WND 2637/27/ 8/57/ 53007 6000/ 10051 20044

SUMMARY FOR FRIDAY, APRIL 26, 2019

TEMPERATURE (DEGREES F)
MAX…..53   NORMAL…..60
MIN…..42   NORMAL…..42
MEAN….48   NORMAL…..51

DEPARTURE FROM 30-YEAR NORMAL……………………-3
TOTAL DEPARTURE FOR THE MONTH…………………..+77 [+2.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..17   DEPARTURE………+3
TOTAL HEATING UNITS FOR THE MONTH………….419   DEPARTURE……..-78
TOTAL HEATING UNITS FOR THE SEASON………..5824   DEPARTURE…….-157
TOTAL HEATING UNITS LAST SEASON TO DATE……5636   DIFFERENCE……+188

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..35 ESE AT  1:38 P.M.
AERO…………………….N/A
ASOS…………………….34 ESE AT 11:49 A.M.
DAVIS……………………34 ESE AT 11:49 A.M.  RMY 33
FASTEST MILE FOR YESTERDAY………………….25 ESE AT  1:37 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….25 E   AT  1:40 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………27 E   AT  1:40 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..13.8 ESE
ASOS…………………..13.6
DAVIS………………….13.8 E [096 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….1.45  DEPARTURE…….+1.31
ASOS…………..1.49
TOTAL PRECIPITATION FOR THE MONTH……….7.89  DEPARTURE…….+3.87
ASOS…………..7.83
TOTAL PRECIPITATION FOR THE YEAR……….20.93  DEPARTURE…….+2.91
ASOS………….20.98

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M………0.0  DEPARTURE………0.0
TOTAL SNOWFALL FOR THE MONTH………….TRACE  DEPARTURE……..-2.9
TOTAL SNOWFALL FOR THE SEASON………….47.6  DEPARTURE…….-15.0

PRELIMINARY CLIMATE SUMMARY FOR MARCH 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        RMY 33

04/27 Low temp since midnight is 42F; normal low is 42F

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

RECORDS FOR APRIL 27
HIGH 93 IN 1990
LOW 28 IN 1919
PRECIP 1.89 IN 1979
SNOWFALL 2.7 IN. IN 1993
PEAK GUST 65e MPH N IN 1941

RECORDS FOR APRIL 28
HIGH 92 IN 1990, 2009
LOW 26 IN 1947
PRECIP 2.41 IN 1904
SNOWFALL 10.0 IN. IN 1987
PEAK GUST 69 MPH NE 1967

TODAY’S REPORT PREPARED BY: Mike Iacono