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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 22, 2017  
ALL TIMES ARE IN EASTERN STANDARD TIME

INTERMITTENT PRECIP. AFTER MORNING SHOWERS

Rain showers began after 3:00AM EST this morning but
stopped before the 7:00AM ob leaving 0.09 in. of precip.
Rain and drizzle were on and off through the rest of the
morning and early afternoon and amounted to just a trace
by 1:00PM.  Despite the rain, fog remained distant all
day with visibility ranging from 10 miles to 50 miles.

Temperatures were also much cooler today.  The max. at
1:00PM was only 52F compared to the normal max. of 68F.
Winds were light and out of the south for much of the
day.  Wind direction shifted east-southeast after noon.


Today's Observations:

7 A.M.
Weather: Few cumulus fractus E, overcast stratus
Temperature: 48F; Dew Point: 46F; Wind: S at 7 kts
Sea-level pressure: 30.23 ins. Hg, rising then falling
Visibility: 50 miles, distant fog in all directions
6-hr Max temp: 52F
6-hr Min temp: 48F
24-hr precip: 0.09 in.
BHO SA 1155 E49 OVC 50 237/48/46/1707/023/ FEW CUFRA E DSNT FG ALQDS/
8/6// 50000 MANUAL 70009 ASOS 70010 10052 20048

10 A.M.
Weather: Light rain, overcast nimbostratus
Temperature: 51F; Dew Point: 45F; Wind: S at 5 kts
Wind speed: Light
Sea-level pressure: 30.21 ins. Hg, falling then rising
Visibility: 10 miles, except 20 miles E-SW, distant fog in all directions
3-hr precip: Trace
BHO SA 1455 E42 OVC 10R- 231/51/45/1805/021/ VSBY E-SW 20
DSNT FG ALQDS WND LGT/ 8/6// 57006 MANUAL 600//

1 P.M. 
Weather: Few cumulus WNW-SSE, overcast stratus
Temperature: 50F; Dew Point: 44F; Wind: ESE at 7 kts
Sea-level pressure: 30.15 ins. Hg, falling unsteadily
Visibility: 40 miles, except 10 miles NNW-NNE,
distant fog in all directions
6-hr Max temp: 52F
6-hr Min temp: 48F
6-hr precip: Trace
BHO SA 1755 E29 OVC 40 210/50/44/1107/015/ FEW CU WNW-SSE VSBY NNW-NNE 10
DSNT FG ALQDS/ 8/6// 58021 MANUAL 600// AS0S 60001 10052 20048


SUMMARY FOR SUNDAY, MAY 21, 2017
 
TEMPERATURE (DEGREES F)
MAX.....66   NORMAL.....68
MIN.....45   NORMAL.....49
MEAN....56   NORMAL.....59

DEPARTURE FROM 30-YEAR NORMAL.........................-3
TOTAL DEPARTURE FOR THE MONTH.........................-5 [-0.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............9   DEPARTURE..........+2
TOTAL HEATING UNITS FOR THE MONTH.............236   DEPARTURE.........+28
TOTAL HEATING UNITS FOR THE SEASON...........5569   DEPARTURE........-673
TOTAL HEATING UNITS LAST SEASON TO DATE......5222   DIFFERENCE.......+347

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................21  E  AT  4:02 P.M.
                   AERO........................20  S  AT  8:25 P.M.
                   ASOS........................22 ENE AT 1:42 P.M.
                   DAVIS.......................21 SSW AT 10:29 P.M. RMY 21
FASTEST MILE FOR YESTERDAY.....................15  E  AT  4:02 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................17  E  AT  4:02 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE.................15 SSW AT 11:33 P.M.
AVERAGE WIND SPEED AND DIRECTION..............9.3 ENE
                   ASOS.......................9.5
                   DAVIS......................7.6 SE [140 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.09  DEPARTURE......-0.04
                         ASOS..............0.10
TOTAL PRECIPITATION FOR THE MONTH..........3.25  DEPARTURE......+0.64
                         ASOS..............3.33
TOTAL PRECIPITATION FOR THE YEAR..........24.06  DEPARTURE......+2.90
                         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/.../..                 35 W   AERO 33 W   RMY 37
5/20 67/49/58/0/0.00/.../..                23 NE  AERO 22 NE  RMY 21
5/21 66/45/56/-3/0.00/.../..               21 E   AERO 20 S   RMY 21

5/22 Low temp since midnight is 48F; normal low is now 49F


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 22
HIGH 93F IN 1911
LOW 35F IN 1907
PRECIP 3.75 INCHES IN 1920
PEAK GUST 49e MPH SSW IN 1947

RECORDS FOR MAY 23
HIGH 92F IN 1964,1992
LOW 38F IN 1976
PRECIP 0.97 INS IN 1979
PEAK GUST 49e MPH W IN 1945

TODAY'S REPORT PREPARED BY: Cecilia Borries-Strigle