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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 27, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

CLOUDY AND COLD AT THE OBSERVATORY

After yesterday's back door cold front, below average temperatures have
moved into place, with temperature's remaining around today's average
low of 51.  Clouds have been present since this morning and a trace of 
precipitation moved through the area early this morning.  Visibility was 
only 5 miles at the 7 AM observation due to fog, but has slowly been 
improving this afternoon as the humidity slowly drops.  

May 2018 is on pace to be one of the warmest May's on record at Blue Hill
with a mean temperature through the 26th of nearly 61F.  It also has a 
chance to become just the fifth May on record to have a monthly average 
temperature of 60F or greater.

Blue Hill Observatory Warmest May Mean Temperature (°F), 1885-2017

1. 61.5 in 2015
2. 61.4 in 1991
3. 61.0 in 1944
4. 60.9 in 2010
5. 59.4 in 1911
   59.4 in 1959
7. 59.3 in 1964
   59.3 in 2012

Today's Observations:

7 A.M.
Weather: Fog
Temperature: 51F; Dew Point: 49F; Wind: ENE at 17G28 kts
Sea-level pressure: 30.13 ins. Hg, rising, then more quickly 
Visibility: 5 miles, Fog
6-hr Max temp: 59F
6-hr Min temp: 51F
24-hr Precip: 0.04 ins.
BHO SA 1155 W4 X 5F 203/51/49/0717G28/013/ PCPN VRY LGT/ 8//// 
53024 MANUAL 70004 ASOS 70004 10059 20051 

10 A.M.
Weather: Overcast Stratus
Temperature: 52F; Dew Point: 46F; Wind: ENE at 15G24 kts
Sea-level pressure: 30.17 ins. Hg, rising, then more slowly
Visibility: 15 miles, distant haze
3-hr Precip: TRACE
BHO SA 1455 E20 OVC 15 216/52/46/0715G24/017/ DSNT HZ/ 8/7// 51013 
ASOS 6000/ MANUAL 6000/

1 P.M.
Weather: Overcast Stratus
Temperature: 51F; Dew Point: 44F; Wind: ENE at 11G23 kts
Sea-level pressure: 30.18 ins. Hg, steady then rising 
Visibility: 30 miles, distant haze 
6-hr Max temp: 53F
6-hr Min temp: 51F
6-hr precip:  TRACE
BHO SA 1755 E24 OVC 30 219/51/44/0611G23/018/ DSNT HZ/ 8/7// 53003 
ASOS 6000/ MANUAL 6000/ 10053 20051 

SUMMARY FOR SATURDAY, MAY 26, 2018

TEMPERATURE (DEGREES F)
MAX.....88   NORMAL.....69
MIN.....61   NORMAL.....51
MEAN....75   NORMAL.....60

DEPARTURE FROM 30-YEAR NORMAL.........................+15
TOTAL DEPARTURE FOR THE MONTH.......................+143 [+5.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............0         DEPARTURE...........-6
TOTAL HEATING UNITS FOR THE MONTH............132     DEPARTURE.........-109
TOTAL HEATING UNITS FOR THE SEASON...........5825   DEPARTURE.........-450
TOTAL HEATING UNITS LAST SEASON TO DATE...5621   DIFFERENCE........+204

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............10   DEPARTURE..........+9
TOTAL COOLING UNITS FOR THE MONTH..............52   DEPARTURE.........+37
TOTAL COOLING UNITS FOR THE SEASON.............52   DEPARTURE.........+35
TOTAL COOLING UNITS LAST SEASON TO DATE.....56   DEPARTURE..........-4

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................38  NE  AT 6:41 P.M.
                   AERO.........................................38  NE  AT 6:39 P.M. 
                   ASOS.........................................42  ENE AT 6:41 P.M.
                   DAVIS........................................38  M   AT 6:41 P.M.** RMY 39
FASTEST MILE FOR YESTERDAY........................27  NE  AT 6:54 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE................28  ENE AT 6:55 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE...............27  M   AT 6:55 P.M.**
AVERAGE WIND SPEED AND DIRECTION...........12.6 W
                   ASOS........................................12.7
                   DAVIS.......................................11.7
** Davis direction malfunctioning 

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.04  DEPARTURE......-0.11
                         ASOS..............0.04
TOTAL PRECIPITATION FOR THE MONTH..........1.92  DEPARTURE......-1.44
                         ASOS..............1.89  
TOTAL PRECIPITATION FOR THE YEAR..........27.23  DEPARTURE......+5.50
                         ASOS.............28.81

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE.........0.0
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE.........0.0
TOTAL SNOWFALL FOR THE SEASON..............92.8  DEPARTURE.......+30.0

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

5/01 65/39/52/-1/0.00/0.0/625/74    25 WNW AERO 21 WNW RMY 25
5/02 88/59/74/+21/0.00/0.0/584/69   37 WSW AERO 29 WSW RMY 35 
5/03 90/67/79/+26/0.13/0.0/433/51   36 SW  AERO 32 WSW RMY 36  
5/04 84/67/74/+20/0.05/0.0/102/12   39 SSW AERO 37 SSW RMY N/A
5/05 73/54/64/+10/0.00/0.0/615/72   56 W   AERO 55 W   RMY N/A
5/06 65/48/57/+3/0.21/0.0/000/00    24 NE  AERO 18 NE  RMY 21
5/07 62/49/56/+1/0.00/0.0/713/83    26 ENE AERO 22 NE  RMY 24
5/08 73/46/60/+5/0.00/0.0/852/99    25 SSE AERO 21 ESE RMY 23 
5/09 74/48/61/+6/0.00/0.0/768/89    23 ESE AERO 18 ESE RMY 21 
5/10 73/48/61/+6/0.03/0.0/355/41    33 S   AERO 30 S   RMY 32 
5/11 70/51/61/+5/0.00/0.0/703/81    26 WNW AERO 24 NW  RMY 28
5/12 51/47/49/-7/0.19/0.0/000/00    25 E   AERO 23 E   RMY N/A
5/13 58/46/52/-4/T/0.0/392/45       20 S   AERO 17 S   RMY 16 
5/14 73/47/60/+3/T/0.0/557/63       23 S   AERO 18 S   RMY 21
5/15 83/54/69/+12/0.74/0.0/333/38   51 NW  AERO 50 NW  RMY 54 TSTM
5/16 56/49/53/-4/T/0.0/.../..       32 ENE AERO 28 ENE RMY 30
5/17 72/51/62/+5/0.02/0.0/.../..    17 SW  AERO 14 SW  RMY N/A
5/18 62/43/53/-5/0.00/0.0/.../..    35 ENE AERO 33 ENE RMY N/A
5/19 57/43/50/-8/.../0.0/.../..     22 E   AERO 17 E   RMY N/A
5/20 77/54/66/+8/.../0.0/.../..     33 SW  AERO 31 SW  RMY 33 TSTM
5/21 75/52/64/+5/0.00/0.0/.../..    22 W   AERO 18 W   RMY 20
5/22 68/51/60/+1/0.04/0.0/.../..    23 SSW AERO 21 S   RMY 22
5/23 82/51/67/+8/0.06/0.0/.../..    33 NNW AERO 33 NNW RMY 34 TSTM
5/24 74/50/62/+3/0.00/0.0/.../..    28 SSW AERO 25 SSW RMY 27 
5/25 86/50/68/+8/0.00/0.0/.../..    40 W   AERO 39 W   RMY 43
5/26 88/61/75/+15/.../0.0/.../..    38 NE  AERO 38 NE  RMY 39

5/27 Low temp since midnight is 51F; normal low is now 51F

DAILY RECORDS FOR MAY 2018

5/03/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
         BREAKS PREVIOUS RECORD OF 66F SET IN 2001

5/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
         BREAKS PREVIOUS RECORD OF 66F SET IN 2001

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

RECORDS FOR MAY 27
HIGH 92F IN 1914
LOW 36F IN 1915
PRECIP 1.40 INS IN 1898
PEAK GUST 55 S IN 1956

RECORDS FOR MAY 28
HIGH 92F IN 2016
LOW 39F IN 1917
PRECIP 2.48 INS 1906
PEAK GUST 51e MPH NE IN 1946

TODAY'S REPORT PREPARED BY: Robert Millette