BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, AUGUST 14, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME
 
VERY SUNNY, BECOMING WINDY, COOL FOR MID-AUGUST AND DRY
REFRESHINGLY COOLER AND DRIER AIR ARRIVES EARLY THIS
MORNING WITH DEW POINTS FALLING FROM THE LOW 60'S
IN THE FIRST THREE HOURS OF THE DAY TO 49F BY 8 A.M.
 
Today is another one of already several very sunny days
this month.  Winds have increased from the WNW and are
gusting over 30 MPH by early this afternoon.  The new
cooler and much drier air mass which arrived early today
is keeping high temperatures in the lower 70's or close
to 10 degrees cooler than normal while the dew point
remains near a comfortable 50F.  Visibility of 75 miles early
this morning has decreased slightly to 65 miles by
early this afternoon.
 
The air mass change from moderately humid to much drier early
today was rather dramatic with dew point falling from the low
60's during the pre-dawn hours down to 49 degrees by 8 A.M. EDT
observation time.  The arrival of the new air mass was only
accompanied by some cloudiness and gentle to moderate winds
from the west-northwest. Visibility was up to 75 miles by
8 A.M. EDT and still increasing.  
 
A period of light rain and rain showers around mid-day yesterday
lasting into the afternoon provided a mere 0.02 of an inch.  A large
batch of heavier rain and embedded t-storms spread to our north, and
especially to our south, leaving us in a lull of light rain. However,
radar reports of heavier rain on Cape Cod were misleading so except
for the Islands south of the Cape, most of Cape Cod received less than
a quarter of an inch of rainfall!  
 
Interestingly, Monday of this week was the first day since July 29
that the average daily temperature actually finished above the 30-year 
normal for any given date.
 
Today's Observations:
 
7 A.M.
Weather: Clear, altocumulus/altocumulus lenticularis mostly distant
ENE-S, layer altocumulus/cirrus/cirrostratus distant off shore E-SE
is receding
Temperature: 60F; Dew Point: 49F; Wind: WNW at 12G20 kts.
Sea-level pressure: 29.74 ins. Hg, rising then more slowly
Visibility: 75 miles
6-hr min. temp: 58F
24-hour rainfall: 0.02 inch
BHO SA 1155 CLR 75 071/60/49/2912G20/974/ AC/ACSL MSTLY DSNT ENE-S
AC/CI/CS LYR DSNT E-SE DSNT OFFSHR RCDNG WND 26V32/ 8/048 51013
MANUAL 70002 ASOS 70001 10064 20058 
 
10 A.M.
Weather: Clear, stratocumulus, few cumulus distant SW-N,
slowly advancing
Temperature: 66F; Dew Point: 51F; Wind: W at 15G21 kts,
Wind: Direction variable 
Sea-level pressure: 29.74 ins. Hg, about steady
Visibility: 70 miles, light distant haze  
BHO SA 1455 CLR 70 070/66/51/2715G21/974/ CU/SC DSNT SW-N SLWLY
ADVCNG HZ ALF E-S WND 24V30/ 8/800 55001
 
1 P.M.
Weather: Clear, shallow cumulus all quadrants 
Temperature: 70F; Dew Point: 50F; Wind: WNW at 15G29 kts,
Wind: Peak wind 29 kts W @ 12:51 P.M.,
Wind: Direction variable WSW-NW 
Sea-level pressure: 29.75 ins. Hg, rising slightly
Visibility: 65 miles, distant haze 
6-hr max. temp: 71F
BHO SA 1755 CLR 65 075/70/50/2915G29/975/ SHLW CU ALQDS DSBT HZ
PK WND 2829/51/ WND 25V31/ 8/100 51005 10071 20060
 
WEATHER SUMMARY FOR TUESDAY, AUGUST 13, 2013
 
TEMPERATURE (DEGREES F)
MAX.....73     NORMAL.....80
MIN.....64     NORMAL.....62
MEAN....69     NORMAL.....71
 
DEPARTURE FROM 30-YEAR NORMAL......................-2
TOTAL DEPARTURE FOR THE MONTH..................,...-25  [-2.1 DEGREES/DAY]
 
COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY.............4    DEPARTURE.........-2
TOTAL COOLING UNITS FOR THE MONTH............63    DEPARTURE........-28
TOTAL COOLING UNITS FOR THE SEASON..........546    DEPARTURE.......+104
TOTAL COOLING UNITS LAST SEASON TO DATE.....598    DIFFERENCE.......-52
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY................16 SSE AT 12:54 P.M. *
                   AERO.....................15 SSE AT 12:54 P.M. *
                   ASOS.....................16 SSE AT 12:54 P.M.
                   DAVIS....................15 SSE AT 12:40 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY..................11 SSE AT 12:52 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...............12 SSE AT 12:48 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..............12 SSE AT 12:48 P.M.
AVERAGE WIND SPEED AND DIRECTION...........6.9 S
                   ASOS....................6.1
                   DAVIS...................6.5 S [190 deg.]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.02   DEPARTURE............-0.10
                         ASOS..............0.01
TOTAL PRECIPITATION FOR THE MONTH..........2.55   DEPARTURE............+0.71
                         ASOS..............2.60
TOTAL PRECIPITATION FOR THE YEAR..........37.82   DEPARTURE............+5.01
                         ASOS..............N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals 
     
PRELIMINARY CLIMATE SUMMARY FOR AUGUST 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
8/1  81/62/72/0/0.01/503/58          25 S   AERO 26 MPH S   RMY 27
8/2  81/62/72/0/0.23/518/60          26 W   AERO 26 MPH W   RMY 28
8/3  77/63/70/-2/T/276/32            22 WSW AERO 23 MPH WSW RMY 23
8/4  79/58/69/-3/T/645/75            25 WNW AERO 21 MPH WNW RMY 26
8/5  75/54/65/-7/0.00/858/100        26 WNW AERO 25 MPH WNW RMY 27
8/6  78/56/67/-5/0.00/846/99         17 ESE AERO 15 MPH S   RMY 16
8/7  80/59/70/-2/0.00/759/89         21 S   AERO 21 MPH S   RMY N/A
8/8  79/62/71/-1/0.08/153/18         25 S   AERO 25 MPH S   RMY N/A
8/9  73/70/72/0/2.21/000/00          37 S   AERO 39 MPH S   RMY 40
8/10 81/61/71/-1/0.00/795/94         30 WNW AERO 31 MPH WNW RMY 31
8/11 78/58/68/-3/0.00/835/99         18 W   AERO 18 MPH W   RMY 21
8/12 81/62/72/+1/0.00/.../..         18 W   AERO 17 MPH WSW RMY 19
8/13 73/64/69/-2/0.02/.../..         16 SSE AERO 15 MPH SSE RMY N/A
 
8/14 morning low temp: 58F; the normal low is now 62F
 
DAILY RECORDS FOR AUGUST 2013
None so far.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR AUGUST 14
HIGH 99F IN 2002
LOW 46F IN 1964
PRECIP 3.06 INCHES IN 1919
PEAK GUST 61 MPH WNW IN 1963
 
RECORDS FOR AUGUST 15
HIGH 95F IN 1928
LOW 47F IN 1964
PRECIP 1.89 INCHES IN 2011
PEAK GUST 44e MPH S IN 1941
 
TODAY'S REPORT PREPARED BY: Robert Skilling/Marc Douglas