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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, JULY 10, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

MOSTLY CLOUDY AND HUMID WITH MORNING FOG AND DRIZZLE 
VERY LOW WIND SPEEDS YESTERDAY

The summit of Great Blue Hill was shrouded in dense fog this morning, with
the visibility reduced to 1/16 of a mile.  This fog gradually dissipated
later in the morning, leaving mostly cloudy skies, but the visibility
struggled to rise above 10 miles as haze continued. The temperature has
risen to 84F by early afternoon despite significant cloud cover.  Dew
points have also been very high, above 70F for much of the day, giving the
air a very humid feel.  Light drizzle this morning provided only a trace of
rainfall.

The average wind speed yesterday was just 5.5 mph, and the peak wind gust
was only 14 mph, which is tied for the lowest peak gust this year.  Winds
have been slightly stronger today, and are increasing early this afternoon,
but the peak gust so far is only 23 mph.  Yesterday's average temperature of 
68F was 4 degrees below average for the date, which is the first below 
normal day this month.  The previous 8 days had averaged about 7 degrees 
above average, and despite yesterday's cooler temperatures the month 
continues to run over 5.5 degrees above average.

Today's Observations:

7 A.M. 

Weather: Light drizzle, sky obscured by dense fog, stratus drifting over
summit, very light drizzle began at 6:50 A.M. EST and continued
Temperature: 68F; Dew Point: 68F; Wind: ESE at 6 kts
Sea-level pressure: 30.03 ins. Hg, falling
Visibility: 1/16 mile, dense fog
24-hr precip: Trace
6-hr precip: Trace
6-hr min. temp: 65F
BHO SA 1155 W3 X 1/16L-F 168/68/68/1206/003/ STRA DRFTNG OVR SMT L-B50 CTD
VRY LGT/ 8//// 57007 MANUAL 7000/ 6000/ 10068 20065

10 A.M. 
Weather: Broken stratocumulus, broken cirrus, few cirrocumulus, thin fog
all quadrants
Temperature: 76F; Dew Point: 73F; Wind: S at 8 kts
Sea-level pressure: 29.98 ins. Hg, falling then falling more rapidly
Visibility: 8 miles, thin fog
3-hr precip: Trace
BHO SA 1455 E8 BKN 250 BKN 8 153/76/73/1808/998/ THN F ALQDS FEW CC/ 8/509 
58015 MANUAL 6000/

1 P.M.
Weather: Broken stratocumulus, broken cumulus, broken dense cirrus, few
cirrocumulus
Temperature: 84F; Dew Point: 73F; Wind: S at 12 kts
Sea-level pressure: 29.91 ins. Hg, falling then falling more rapidly
Visibility: 12 miles, hazy
6-hour precip: Trace
6-hour max. temp: 84F
BHO SA 1755 E15 BKN 35 BKN 200 BKN 12 131/84/73/1812/991/ HAZY FEW CC/ 
8/509 58022 MANUAL 6000/ 10084 20068

WEATHER SUMMARY FOR TUESDAY, JULY 9, 2013

TEMPERATURE (DEGREES F)
MAX.....72     NORMAL.....81
MIN.....63     NORMAL.....63
MEAN....68     NORMAL.....72

DEPARTURE FROM 30-YEAR NORMAL.....................-4
TOTAL DEPARTURE FOR THE MONTH....................+53 [+5.7 DEGREES/DAY]

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY................14 ENE AT  6:43 P.M. *
                   AERO.....................14 ENE AT  5:28 P.M. 
                   ASOS.....................14 ENE AT  7:31 P.M.
                   DAVIS....................N/A                   RMY 14
FASTEST MILE FOR YESTERDAY..................11 ENE AT  6:43 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...............12 ENE AT  6:37 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..............N/A
AVERAGE WIND SPEED AND DIRECTION...........5.5 NE
                   ASOS....................5.6
                   DAVIS...................5.1 ENE [58 deg]
* last of several occurrences...

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)

TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace   DEPARTURE...........-0.11
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.31   DEPARTURE...........-0.68
                         ASOS..............0.30
TOTAL PRECIPITATION FOR THE YEAR..........32.51   DEPARTURE...........+4.55
                         ASOS..............N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals  

PRELIMINARY CLIMATE SUMMARY FOR JULY 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

7/1  82/69/76/+6/0.05/247/27         29 S   AERO 31 MPH SSW RMY 32
7/2  82/61/72/+2/T/100/11            23 SSW AERO 23 MPH SSW RMY 25
7/3  87/62/75/+4/T/556/61            28 SW  AERO 30 MPH SW  RMY 30
7/4  90/71/81/+10/0.00/811/89        25 WSW AERO 26 MPH SW  RMY 28
7/5  92/73/83/+12/0.00/874/96        24 W   AERO 25 MPH WSW RMY 25
7/6  90/73/82/+11/0.00/836/92        25 WNW AERO 25 MPH WNW RMY 26
7/7  91/72/82/+11/0.21/508/56        38 SSW AERO 43 MPH SSW RMY 44  TSTM
7/8  82/64/73/+1/0.04/.../..         18 NE  AERO 20 MPH NE  RMY 20  TSTM
7/9  72/63/68/-4/0.01/.../..         14 ENE AERO 14 MPH ENE RMY 14  

7/10 morning low temp: 65F; the normal low is now 63F

DAILY RECORDS FOR JULY 2013
None so far.

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

RECORDS FOR JULY 10
HIGH 99F IN 1911
LOW 46F IN 1890
PRECIP 1.68 INS IN 1933
WIND 75 MPH W IN 1985

RECORDS FOR JULY 11
HIGH 98F IN 1911
LOW 49F IN 1890
PRECIP 1.87 INS IN 1959
WIND 53 MPH NW IN 1988

TODAY'S REPORT PREPARED BY: Jonathan O'Brien and Mark Medlinskas