Wednesday, May 31, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, MAY 31, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

LIGHT, BRIEF SHOWERS TODAY AS SKIES SLOWLY CLEAR

Very light showers fell during the day between before
6:00AM EST and again before 12:00PM.  The extra moisture
made for a humid day with dew points in the upper 50s.
Temps. had reached 67F by 1:00PM.  Skies began to clear
near noon, and the first bit of sunshine in almost three
days was recorded shortly after.  The slightest bit of
blue sky could be seen at the 1:00PM observation.

Today’s Observations:

7 A.M.
Weather: Sky obscurement due to thick fog
Temperature: 55F; Dew Point: 55F; Wind: S at 9 kts
Sea-level pressure: 30.09 ins. Hg, falling then rising
Visibility: 1/8 mile
6-hr Max temp: 55F
6-hr Min temp: 52F
24-hr precip: Trace
BHO SA 1155 W2 X 1/8F 188/55/55/1909/009/ 8//// 55001 10055 20052

10 A.M.
Weather: Overcast stratocumulus
Temperature: 61F; Dew Point: 57F; Wind: SSW at 5 kts,
Wind speed: Light
Sea-level pressure: 30.07 ins. Hg, rising then falling
Visibility: 15 miles, except 30 miles NNE-S, distant fog S-NNE
BHO SA 1455 E7 15 184/61/57/2105/007/ VSBY NNE-S 30
DSNT FG S-NNE WND LGT/ 8/5// 58004

1 P.M.
Weather: Broken cumulus, broken altostratus
Temperature: 67F; Dew Point: 59F; Wind: S at 5 kts,
Wind speed: Light
Sea-level pressure: 30.02 ins. Hg, falling then more quickly
Visibility: 20 miles, except 15 miles N, distant fog N
6-hr Max temp: 67F
6-hr Min temp: 55F
6-hr precip: Trace
BHO SA 1755 E31 BKN 160 BKN 20 166/67/59/1805/002/ VSBY N 15
DSNT FG N WND LGT/ 8/110 58018 10067 20055

SUMMARY FOR TUESDAY, MAY 30, 2017

TEMPERATURE (DEGREES F)
MAX…..61   NORMAL…..70
MIN…..46   NORMAL…..52
MEAN….54   NORMAL…..61

DEPARTURE FROM 30-YEAR NORMAL…………………….-7
TOTAL DEPARTURE FOR THE MONTH……………………-49 [-1.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..11   DEPARTURE……….+6
TOTAL HEATING UNITS FOR THE MONTH………….325   DEPARTURE………+62
TOTAL HEATING UNITS FOR THE SEASON………..5658   DEPARTURE……..-640
TOTAL HEATING UNITS LAST SEASON TO DATE……5248   DIFFERENCE…….+410

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….20  S  AT 11:14 P.M.
AERO……………………22  S  AT 10:20 P.M.
ASOS……………………22  S  AT 11:15 P.M.
DAVIS…………………..19 SSE AT  8:06 P.M. RMY 21
FASTEST MILE FOR YESTERDAY…………………15  S  AT 10:22 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………16  S  AT 11:20 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..13  S  AT 10:22 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..5.8  S
ASOS…………………..6.1
DAVIS………………….4.4 SE [140 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…Trace  DEPARTURE……-0.16
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….4.52  DEPARTURE……+0.56
ASOS…………..4.66
TOTAL PRECIPITATION FOR THE YEAR……….25.33  DEPARTURE……+2.82
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/-7/0.01/453/52               21 NE  AERO 20 NE  RMY 19
5/13 57/41/49/-7/0.19/009/01               24 ENE AERO 24 E   RMY N/A
5/14 47/43/45/-12/1.49/000/00              33 NNE AERO 36 N   RMY 36
5/15 58/43/51/-6/0.24/018/02               36 NNW AERO 40 NNW RMY 41
5/16 79/51/65/+8/0.00/870/99               26 WNW AREO 26 WNW RMY 29
5/17 90/60/75/+18/T/775/88                 32 SSE AERO 33 SW* RMY 34
5/18 96/69/83/+25/0.01/830/94              39 WNW AERO 41 WNW RMY 42 TSTM
5/19 89/56/73/+15/T/814/92                 35 W   AERO 33 W   RMY 37
5/20 67/49/58/0/0.00/709/80                23 NE  AERO 22 NE  RMY 21
5/21 66/45/56/-3/0.00/773/87               21 E   AERO 20 S   RMY 21
5/22 53/48/51/-8/…./000/00               22 S   AERO 22 S   RMY 23
5/23 70/51/61/+2/…./366/41               21 NNW AERO 18 NNW RMY 19
5/24 65/53/59/0/0.00/116/13                17 E   AERO 16 E   RMY N/A
5/25 53/49/51/-9/…./000/00               36 E   AERO 38 E   RMY N/A TSTM
5/26 56/46/51/-9/…./…/..               35 N   AERO 37 N   RMY N/A
5/27 67/51/59/6/0.00/…/..                18 SE  AERO 18 SE  RMY 19
5/28 71/51/61/0/T/…/..                   18 SSW*AERO 18 SSW RMY 18
5/29 51/46/49/-12/…./…/..              21 E   AERO 20 ENE*RMY 20
5/30 61/46/54/-7/0.00/000/00               20 S   AERO 22 S   RMY 21

5/31 Low temp since midnight is 52F; normal low is now 52F

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 96F,
BREAKS PREVIOUS RECORD OF 88F SET IN 1906
AND TIED IN 1936 AND 1986;
BREAKS PREVIOUS MONTHLY RECORD OF 94F SET ON
MAY 26, 2010

5/18/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 69F,
BREAKS PREVIOUS RECORD OF 61F SET IN 1943

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

RECORDS FOR MAY 31
HIGH 92F IN 1944,1987,2013
LOW 35F IN 1961
PRECIP 5.02 INS 1984 (RECORD FOR MAY)
PEAK GUST 54e MPH WNW IN 1945

RECORDS FOR JUNE 1
HIGH 90F IN 1937,2013
LOW 36F IN 1945 [Record for month] PRECIP 2.28 INS IN 1992
PEAK GUST 51e MPH SE IN 1952

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle