Wednesday, May 10, 2017
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, MAY 10, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME
ANOTHER COOL, MOSTLY CLOUDY DAY
There was not much variation from yesterday to today with
continuing lower than average temperatures and cloudy skies.
Morning skies cleared briefly, but increasing moisture led
to more cloud development by the afternoon. More passing
rain showers yesterday afternoon and evening gave us a trace
of precip. Winds were light and had become easterly in the
afternoon.
FROM THE RECORD BOOKS:
40TH ANNIVERSARY OF MAY 9-10, 1977 SNOWSTORM
An unusually cold spring storm brought significant snow, sleet,
and rain to southern New England on May 9-10, 1977. The total
snowfall at the Observatory was 7.8 inches over the two days,
which is the largest snowfall ever observed so late in the season
and the record largest snowfall in May. The total liquid equivalent
precipitation over both days was 3.12 inches. A maximum temperature
of 40 deg F was observed on May 10, 1977, which remains the record
low maximum temperature for that date. The minimum temperature of
32 deg F on that date is not a record, but it is one of the latest
freezing temperatures ever observed. This storm was not the latest
measurable snowfall at the Observatory. That occurred 110 years ago
on May 11, 1907 when exactly one inch of snow was measured.
Today’s Observations:
7 A.M.
Weather: Broken altocumulus
Temperature: 46F; Dew Point: 33F; Wind: NW at 8 kts
Sea-level pressure: 30.00 ins. Hg, rising, then more slowly
Visibility: 70 miles
6-hr Max temp: 46F
6-hr Min temp: 42F
24-hr precip: Trace
BHO SA 1155 E79 BKN 70 160/46/33/3108/000/ 8/030 51011 10046 20042
10 A.M.
Weather: Broken cumulus, broken altocumulus
Temperature: 54F; Dew Point: 30F; Wind: WNW at 5 kts,
Wind Speed: Light
Sea-level pressure: 30.00 ins. Hg, rising then falling
Visibility: 70 miles
BHO SA 1455 E42 BKN 74 BKN 70 159/54/30/3005/000/ WND LGT/ 8/230 58001
1 P.M.
Weather: Few cumulus ESE, broken stratocumulus, broken altocumulus,
broken cirrostratus
Temperature: 55F; Dew Point: 32F; Wind: E at 4 kts,
Wind speed: Light
Sea-level pressure: 30.00 ins. Hg, falling then rising
Visibility: 70 miles
6-hr Max temp: 55F
6-hr Min temp: 46F
BHO SA 1755 E60 BKN 74 BKN 220 BKN 70 160/55/32/0904/000/
FEW CU ESE WND LGT/ 8/538 53001 10055 20046
SUMMARY FOR TUESDAY, MAY 9, 2017
TEMPERATURE (DEGREES F)
MAX…..53 NORMAL…..64
MIN…..36 NORMAL…..46
MEAN….45 NORMAL…..55
DEPARTURE FROM 30-YEAR NORMAL……………………-10
TOTAL DEPARTURE FOR THE MONTH……………………-27 [-2.9 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..20 DEPARTURE………+10
TOTAL HEATING UNITS FOR THE MONTH………….126 DEPARTURE………+23
TOTAL HEATING UNITS FOR THE SEASON………..5459 DEPARTURE……..-679
TOTAL HEATING UNITS LAST SEASON TO DATE……5148 DIFFERENCE…….+311
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….20 ESE AT 11:29 A.M.
AERO……………………17 ESE AT 11:29 A.M.
ASOS……………………19 ESE AT 11:26 A.M.
DAVIS…………………..16 ESE AT 11:50 A.M. RMY 19
FASTEST MILE FOR YESTERDAY…………………13 ESE AT 11:24 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………14 ESE AT 11:27 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..12 E AT 11:27 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..5.2 ESE
ASOS…………………..5.5
DAVIS………………….3.8 W [270 deg.]
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…Trace DEPARTURE……-0.11
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.22 DEPARTURE……+0.12
ASOS…………..1.27
TOTAL PRECIPITATION FOR THE YEAR……….22.03 DEPARTURE……+2.38
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings
PRELIMINARY CLIMATE SUMMARY FOR MAY 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
M: Missing data
5/1 50/43/47/-6/T/…/.. 21 N AERO 18 N RMY 22
5/2 65/42/54/+1/0.26/…/.. 41 W AERO 44 W RMY 43
5/3 52/42/53/0/0.00/…/.. 37 WNW*AERO 39 WNW RMY 40
5/4 65/40/53/-1/0.00/…/.. 23 S AERO 23 S RMY 24
5/5 51/44/48/-6/0.73/…/.. 28 E AERO 28 E RMY N/A
5/6 65/50/58/+4/0.23/…/.. 46 SSE AERO 48 SSE RMY 49
5/7 63/47/55/0/T/…/.. 35 S AERO 38 S RMY 39
5/8 54/38/46/-9/T/…/.. 29 WSW AERO 29 WSW RMY 32
5/9 53/36/45/-10/T/…/.. 20 ESE AERO 17 ESE RMY 19
5/10 Low temp since midnight is 42F; normal low is now 46F
DAILY RECORDS FOR MAY
None so far.
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR MAY 10
HIGH 93F IN 1896
LOW 29F IN 1900
PRE 1.85 INS IN 1998
SNOW 2.8 INS 1977 (7.8 INS TOTAL 5/9-5/10 1977)
PEAK GUST 64 MPH S IN 1990
RECORDS FOR MAY 11
HIGH 90F IN 1993
LOW 28F IN 1900
PRE 1.28 INS IN 1957
SNOW 1.0 INS IN 1907 (LATEST MEASURABLE SNOW ON RECORD)
PEAK GUST 75e MPH NW IN 1945
TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle / Nicholas Rousseau / Mike Iacono
