Thursday, May 18, 2017
BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MAY 18, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME
RECORD BREAKING HEAT CONTINUES, 94F BY 1:00PM EST
Temperatures had risen to 94F by 1:00PM, breaking the previous
record of 88F set in 1936 and tied in 1986. This also ties the
highest temperature ever recorded in May at BHO which was set
in 2010. Yesterday’s minimum temperature of 60F also tied the
high minimum record. Today’s minimum of 69F is on track to breaking
the previous record of 61F set in 1943.
Hazy conditions and air quality alerts continued today. Visibility
was only 20 miles during the morning observations, but increased to
40 miles by afternoon. Winds were gusting up to 25 MPH and were
out of the southwest.
The average maximum temperature of 56.8F for the first 15 days of
May 2017 ranks as the sixth coldest since 1885. However, ranking
the maximum temperature over the first 15 days of May shows that
the reading of 65F this month (on May 2, May 4, and May 6) is the
coldest on record.
BHO Coldest 1st-15th May Average Maximum Temperature, deg F (1885-2017)
1) 48.6 in 1917
2) 55.3 in 1885
3) 56.0 in 1962
4) 56.1 in 1921
5) 56.5 in 1954
6) 56.8 in 2017
7) 56.9 in 1920
8) 57.0 in 1907
BHO Coldest 1st-15th May Maximum Temperature, deg F (1885-2017):
1) 65 in 2017
2) 66 in 1917
3) 68 in 1962
68 in 1967
5) 69 in 1966
6) 70 in 1898
70 in 1928
Today’s Observations:
7 A.M.
Weather: Scattered cirrus
Temperature: 76F; Dew Point: 63F; Wind: WSW at 9G14 kts
Sea-level pressure: 29.92 ins. Hg, rising then steady
Visibility: 20 miles, hazy
6-hr Max temp: 76F
6-hr Min temp: 69F
24-hr precip: 0.00 in.
BHO SA 1155 250 SCT 20 131/76/63/2509G14/992/ HAZY/ 8/001 51010
10076 20069
10 A.M.
Weather: Few cirrus in all directions
Temperature: 89F; Dew Point: 56F; Wind: SSW at 13G19 kts
Sea-level pressure: 29.87 ins. Hg, falling, then more quickly
Visibility: 20 miles, hazy
BHO SA 1455 CLR 20 116/89/56/2513G19/987/ FEW CI ALQDS HAZY/
8/001 58015
1 P.M.
Weather: Few altocumulus W-N, scattered cirrus, patches of
cirrocumulus N-SW
Temperature: 93F; Dew Point: 49F; Wind: W at 12G23 kts
Sea-level pressure: 29.83 ins. Hg, falling steadily
Visibility: 40 miles, distant haze in all directions
6-hr Max temp: 94F
6-hr Min temp: 75F
BHO SA 1755 250 SCT 40 100/93/49/2811G21/983/ FEW AC W-N
PTCHS CC N-SW DSNT HZ ALQDS/ 8/069 56016 10094 20075
SUMMARY FOR WEDNESDAY, MAY 17, 2017
TEMPERATURE (DEGREES F)
MAX…..90 NORMAL…..67
MIN…..60 NORMAL…..48
MEAN….75 NORMAL…..57
DEPARTURE FROM 30-YEAR NORMAL……………………+18
TOTAL DEPARTURE FOR THE MONTH……………………-42 [-2.7 DEGREES/DAY]
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0 DEPARTURE……….-8
TOTAL HEATING UNITS FOR THE MONTH………….220 DEPARTURE………+43
TOTAL HEATING UNITS FOR THE SEASON………..5553 DEPARTURE……..-659
TOTAL HEATING UNITS LAST SEASON TO DATE……5200 DIFFERENCE…….+353
COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..10 DEPARTURE……….+9
TOTAL COOLING UNITS FOR THE MONTH…………..10 DEPARTURE……….+4
TOTAL COOLING UNITS FOR THE SEASON………….30 DEPARTURE………+22
TOTAL COOLING UNITS LAST SEASON TO DATE………4 DIFFERENCE……..+26
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….32 SSW AT 5:27 P.M.
AERO……………………33 SW AT 5:25 P.M.*
ASOS……………………33 SW AT 5:27 P.M.
DAVIS…………………..33 SSW AT 6:01 P.M. RMY 34
FASTEST MILE FOR YESTERDAY…………………26 SW AT 5:26 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………25 SSW AT 5:27 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..25 SSW AT 5:27 P.M.
AVERAGE WIND SPEED AND DIRECTION………….12.9 SW
ASOS………………….12.6
DAVIS…………………11.4 SW [230 deg.]
*LAST OF MULTIPLE 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……….3.15 DEPARTURE……+1.07
ASOS…………..3.22
TOTAL PRECIPITATION FOR THE YEAR……….23.96 DEPARTURE……+3.33
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/034/04 21 N AERO 18 N RMY 22
5/2 65/42/54/+1/0.26/136/16 41 W AERO 44 W RMY 43
5/3 52/42/53/0/0.00/595/70 37 WNW*AERO 39 WNW RMY 40
5/4 65/40/53/-1/0.00/724/85 23 S AERO 23 S RMY 24
5/5 51/44/48/-6/0.73/000/00 28 E AERO 28 E RMY N/A
5/6 65/50/58/+4/0.23/094/11 46 SSE AERO 48 SSE RMY 49
5/7 63/47/55/0/T/670/78 35 S AERO 38 S RMY 39
5/8 54/38/46/-9/T/224/26 29 WSW AERO 29 WSW RMY 32
5/9 53/36/45/-10/T/251/29 20 ESE AERO 17 ESE RMY 19
5/10 57/42/50/-5/0.00/225/26 17 NNE AERO 16 NW RMY N/A
5/11 58/45/52/-4/0.00/443/51 23 NE* AERO 23 NE RMY 23
5/12 57/41/49/-7/0.01/…/.. 21 NE AERO 20 NE RMY 19
5/13 57/41/49/-7/0.19/…/.. 24 ENE AERO 24 E RMY N/A
5/14 47/43/45/-12/1.49/…/.. 33 NNE AERO 36 N RMY 36
5/15 58/43/51/-6/0.24/…/.. 36 NNW AERO 40 NNW RMY 41
5/16 79/51/65/+8/0.00/…/.. 26 WNW AREO 26 WNW RMY 29
5/17 90/60/75/+18/T/…/.. 32 SSE AERO 33 SW* RMY 34
5/18 Low temp since midnight is 69F; normal low is now 48F
DAILY RECORDS FOR MAY
5/17/17: DAILY RECORD MAXIMUM TEMPERATURE OF 90F,
BREAKS PREVIOUS RECORD OF 88F SET IN 1974
AND TIED IN 1977
5/17/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 60F,
TIES PREVIOUS RECORD SET IN 1932
5/18/17: DAILY RECORD MAXIMUM TEMPERATURE OF 94F (through 13E),
BREAKS PREVIOUS RECORD OF 88F SET IN 1906
AND TIED IN 1936 AND 1986
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
RECORDS FOR MAY 18
HIGH 88F IN 1906, 1936, 1986
LOW 35F IN 2002
PRECIP 1.93 INS IN 2007
SNOW TRACE IN 2002 (Ice pellets)
PEAK GUST 64 MPH SSW IN 2000
RECORDS FOR MAY 19
HIGH 91F IN 1962
LOW 34F IN 2002
PRECIP 1.54 INCHES IN 1900
PEAK GUST 58 MPH NW IN 1964
TODAY’S REPORT PREPARED BY: Nick Rousseau and Cecilia Borries-Strigle
