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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 18, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME
 
DRY, COOL, AND BLUSTERY DAY WITH WIND FROM THE NORTHEAST...

Strong wind gusts from the northeast kept temperatures 
well below seasonable with a day time high of 54F so far 
today. This is 13 degrees below the daily normal of 67F. 
Our max so far today of 61F was at midnight when the wind was 
coming from the south. The wind shifted to the NE and soon 
after temperatures began to drop keeping temperatures 
between 51-54 since the early morning. The wind has been 
strong today with frequent gust over 22 kts (25 MPH) and 
a peak gust so far of 31 kts (36 MPH). 

Today's Observations:

7 A.M.
Weather: Broken altocumulus, overcast cirrostratus 
Temperature: 53F; Dew Point: 40F; Wind: NE at 18G30 kts
Peak wind: 30 kts (35 MPH) at 6:49 A.M. 
Sea-level pressure: 30.33 ins. Hg, rising, then more quickly    
Visibility: 40 miles, distant fog in all directions
6-hr Max temp: 61F
6-hr Min temp: 53F
24-hr precip: Trace
BHO SA 1155 E190 BKN E250 OVC 40 271/53/40/0518G30/033/ 
DSNT FG ALQDS PK WND 0530/49/ 8/066 53031 10061 20053

10 A.M.
Weather: Broken cirrus, broken cirrostratus
Temperature: 52F; Dew Point: 37F; Wind: ENE at 16G29 kts,
Peak wind: 31 kts (40 MPH) at 9:35 A.M.  
Sea-level pressure: 30.40 ins. Hg, rising, then more slowly
Visibility:  70 miles
3-hr precip: 0.00 ins. 
BHO SA 1455 E220 BKN 300 BKN 70 293/52/37/0616G29/040/ 
PK WND 0631/35/ 8/006 51022   

1 P.M.
Weather: Broken cirrostratus, few cirrus SW-E
Temperature: 53F; Dew Point: 34F; Wind: NE at 14G22 kts 
Sea-level pressure: 30.43 ins. Hg, rising, then more slowly
Visibility:  70 miles
6-hr Max temp: 54F
6-hr Min temp: 51F
6-hr precip:   0.00 ins. 
BHO SA 1755 E250 BKN 70 305/53/34/0614G22/043/ FEW CI SW-E/ 
8/036 50012 10054 20051 

SUMMARY FOR THURSDAY, MAY 17, 2018

TEMPERATURE (DEGREES F)
MAX.....72   NORMAL.....67
MIN.....51   NORMAL.....48
MEAN....62   NORMAL.....57

DEPARTURE FROM 30-YEAR NORMAL..........................+5 
TOTAL DEPARTURE FOR THE MONTH........................+107 [+6.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............3   DEPARTURE..........-5
TOTAL HEATING UNITS FOR THE MONTH.............97   DEPARTURE.........-80
TOTAL HEATING UNITS FOR THE SEASON..........5790   DEPARTURE........-422
TOTAL HEATING UNITS LAST SEASON TO DATE.....5553   DIFFERENCE.......+237

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............0   DEPARTURE..........-1
TOTAL COOLING UNITS FOR THE MONTH..............36   DEPARTURE.........+30
TOTAL COOLING UNITS FOR THE SEASON.............36   DEPARTURE.........+28
TOTAL COOLING UNITS LAST SEASON TO DATE........30   DEPARTURE..........+6

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................17 SW  AT 10:36 P.M.
                   AERO........................14 SW  AT 10:36 P.M. 
                   ASOS........................16 SSW AT  8:41 P.M.
                   DAVIS.......................15 M   AT  7:38 P.M.** RMY N/A
FASTEST MILE FOR YESTERDAY.....................13 SW  AT 10:36 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................13 SW  AT 10:20 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE.................12 M   AT  8:35 P.M.**
AVERAGE WIND SPEED AND DIRECTION..............5.1 SW
                   ASOS.......................5.7 
                   DAVIS......................5.3 M**

** Davis direction malfunctioning 

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..........1.37  DEPARTURE......-0.71
                         ASOS..............1.32  
TOTAL PRECIPITATION FOR THE YEAR..........26.68  DEPARTURE......+6.23
                         ASOS.............28.24

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 90/67/70/+26/..../0.0/433/51   36 SW  AERO 32 WSW RMY 36  
5/04 84/67/74/+20/..../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/..../0.0/768/89    23 ESE AERO 18 ESE RMY 21 
5/10 73/48/61/+6/..../0.0/.../..    33 S   AERO 30 S   RMY 32 
5/11 70/51/61/+5/..../0.0/.../..    26 WNW AERO 24 NW  RMY 28
5/12 51/47/49/-7/0.19/0.0/.../..    25 E   AERO 23 E   RMY N/A
5/13 58/46/52/-4/T/0.0/.../..       20 S   AERO 17 S   RMY 16 
5/14 73/47/60/+3/0.00/0.0/.../..    23 S   AERO 18 S   RMY 21
5/15 83/54/69/+12/..../0.0/.../..   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 Low temp since midnight is 51F; normal low is now 48F

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 18
HIGH 96F IN 2017
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: Kaitlin Geagan