Saturday, April 30, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, APRIL 30, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

SKIES CLEAR AS TEMPERATURES RISE INTO THE 60S

After a partly cloudy start, skies have cleared with only a few
cirrus and fair weather cumulus clouds remaining on the horizon.
Temperatures, which had gotten down into the 30’s overnight, have
rebounded throughout the day climbing into the upper 60s by the
1 o’clock observation.

Winds have decreased since this morning, remaining calm several
times this morning.  Humidities have dropped quickly from this
morning leading to very dry conditions.

Visibilities are low with hazy conditions.

Today’s Observations:

7 A.M.
Weather: Scattered Cirrostratus
Temperature: 45F; Dew Point: 34F; Wind: WSW at 6 kts,
Sea-level pressure: 30.23 ins. Hg, rising, then more quickly
Visibility: 50 miles
6-hr Max temp: 45F
6-hr Min temp: 39F
24-hr precip: 0.00 in.
BHO SA 1155 180 SCT 50 238/45/34/2406/023/ WND LGT
LGT DSNT HZ/ 8/005 53024 10045 20039

10 A.M.
Weather: Few Cirrus, Few Cirrostratus
Temperature: 57F; Dew Point: 31F; Wind: estimated SE at 4 kts,
Wind: Light and variable
Sea-level pressure: 30.20 ins. Hg, rising, then falling
Visibility: 50 miles
BHO SA 1455 CLR 50 229/57/31/E1304/020/FEW CI S-NW FEW CS NW
WND L/V/ LGT DSNT HZ/ 8/009 58009

1 P.M.
Weather: Few cumulus, few cirrostratus
Temperature: 61F; Dew Point: 28F; Wind: E at 10 kts,
Sea-level Pressure: 30.15 ins. HG, falling then more rapidly
Visibility: 55 miles
6-hr Max temp: 61F
6-hr Min temp: 45F
BHO SA 1755 CLR 55 219/61/28/0810/015/ FEW CU SW-NW FEW CS W
LGT DSNT HZ 8/108 56010 10061 20045

SUMMARY FOR FRIDAY, APRIL 29, 2016

TEMPERATURE (DEGREES F)
MAX…..56   NORMAL…..61
MIN…..39   NORMAL…..42
MEAN….48   NORMAL…..52

DEPARTURE FROM 30-YEAR NORMAL…………………….-4
TOTAL DEPARTURE FOR THE MONTH……………………-19 [-0.9] DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..17   DEPARTURE……….+4
TOTAL HEATING UNITS FOR THE MONTH………….558   DEPARTURE………+20
TOTAL HEATING UNITS FOR THE SEASON………..4977   DEPARTURE…….-1045
TOTAL HEATING UNITS LAST SEASON TO DATE……6257   DIFFERENCE……-1280

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….20  ESE  AT   3:37 P.M.
ASOS……………………19  SE   AT   6:30 P.M.
DAVIS…………………..19  SE   AT   6:10 P.M.  RMY 20
FASTEST MILE FOR YESTERDAY…………………14  SE   AT   6:34 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………14  SSE  AT   8:44 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..14  SE   AT   6:36 P.M.
AVERAGE WIND SPEED AND DIRECTION……………8.0 ESE
ASOS……………………8.2
DAVIS…………………..7.1 SE [125 Deg.] * last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00 DEPARTURE…….-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….4.36  DEPARTURE……-0.05  (corrected)
ASOS…………..4.36
TOTAL PRECIPITATION FOR THE YEAR……….16.94  DEPARTURE……-1.47  (corrected)
ASOS………….17.37

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.0
TOTAL SNOWFALL FOR THE MONTH……………15.0  DEPARTURE……+12.0
TOTAL SNOWFALL FOR THE SEASON…………..57.5  DEPARTURE…….-5.7

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

4/1  66/54/60/+19/0.06/0.0/092/12          39 SSW AERO N/A    RMY 43
4/2  54/40/47/+6/0.47/0.0/023/03           23 SSW AERO N/A    RMY N/A
4/3  40/23/32/-10/0.85/7.7/354/46          46 W   AERO N/A    RMY 55
4/4  28/21/25/-17/0.63/7.3/000/00          29 NNE AERO N/A    RMY 25
4/5  35/19/27/-16/0.00/0.0/660/85          25 NW  AERO N/A    RMY 27
4/6  41/21/31/-12/T/0.0/483/62             44 S   AERO N/A    RMY N/A
4/7  56/41/49/+6/1.41/0.0/000/00           53 SSE AERO 59 SSE RMY 55
4/8  52/32/42/-2/T/0.0/353/45              41 WSW AERO 45 WSW RMY 42
4/9  47/29/38/-6/0.00/0.0/417/53           33 NW  AERO 39 NW  RMY 32
4/10 49/26/38/-7/0.00/0.0/735/93           30 NW  AERO 32 NW  RMY 31
4/11 58/40/49/+4/0.01/T/182/23             47 S   AERO 52 S   RMY N/A
4/12 59/37/48/+3/0.30/0.0/040/05           53 S   AERO 60 S   RMY 54
4/13 53/33/43/-3/0.00/0.0/798/100          21 NNW AERO 25 NNW RMY 21
4/14 48/33/41/-5/0.00/0.0/793/99           28 ENE AERO 28 NNE RMY 26
4/15 54/35/45/-2/0.00/0.0/804/100          26 NNE AERO 28 NNE RMY N/A
4/16 52/39/46/-1/0.00/0.0/783/97           36 NNE AERO 31 NNE RMY 34
4/17 62/36/49/+2/0.00/0.0/809/100          20 NNE AERO 20 NNE RMY 19
4/18 67/45/56/+8/0.00/0.0/715/88           28 ENE AERO 29 NE  RMY 28
4/19 55/41/48/0/0.05/0.0/440/54            25 NW  AERO 30 NW  RMY N/A
4/20 57/41/49/0/0.00/0.0/801/98            29 NNW AERO 30 NNW RMY 29
4/21 76/38/57/+8/0.00/0.0/795/97           28 W   AERO 29 WSW RMY 28
4/22 80/56/68/+19/0.03/0.0/313/38          36 S   AERO 37 S   RMY 36
4/23 60/46/53/+3/0.19/0.0/289/35           26 NNW AERO 60 NNW RMY 24
4/24 59/38/49/-1/0.00/0.0/770/93           23 NW  AERO 25 NW  RMY 24
4/25 63/41/52/+2/0.00/0.0/158/19           23 W   AERO 24 W   RMY N/A
4/26 52/35/44/-7/0.36/0.0/000/00           33 E   AERO 35 E   RMY 31
4/27 61/33/47/-4/0.00/0.0/761/91           28 S   AERO 39 S   RMY 29
4/28 60/37/49/-3/0.00/0.0/670/80           26 S   AERO 30 S   RMY 27
4/29 56/40/48/-4/0.00/0.0/563/67           20 ESE AERO 22 SE  RMY 20

4/30 low temp since midnight is 39F; normal now 42F

DAILY RECORDS FOR APRIL 2016

4/1/16: NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 54F,
BREAKS PREVIOUS RECORD OF 51F SET IN 1948

4/4/16: NEW DAILY RECORD SNOWFALL OF 7.3 INS,
BREAKS PREVIOUS RECORD OF 3.7 INS SET IN 1975

4/4/16: NEW DAILY RECORD LOW MAXIMUM TEMPERATURE OF 28F,
BREAKS PREVIOUS RECORD OF 32F SET AND TIED IN 1896, 1908, 1975

4/22/16: NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 56F,
BREAKS PREVIOUS RECORD OF 55F IN 1977 AND 1992

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

RECORDS FOR APRIL 30
HIGH 86 IN 1942
LOW 30 IN 1931
PRECIP 1.41 IN 1991
SNOWFALL 0.3 IN. IN 1909
PEAK GUST 64e MPH NW IN 1978

RECORDS FOR MAY 1
HIGH 87F IN 1899
LOW 29F IN 1978
PRECIP 2.53 INCHES IN 1921
SNOWFALL TRACE IN 1905,1917,1921,1995.
PEAK GUST 57 MPH NW IN 1974

TODAY’S REPORT PREPARED BY: Robert Millette