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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, JULY 9, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

A LITTLE ON THE COOL SIDE WITH PERSISTENT E-NE WIND;
DENSE MORNING FOG TRANSITIONS TO AFTERNOON OVERCAST

The wind direction has persisted from the E-NE since yesterday's back
door cold front passage.  As a result, temperatures have remained on the
cool side.  The morning low matched the 30-year normal of 63F, but the
afternoon high so far today has struggled to reach the lower 70s.  As a
result, today will be the first below normal day after the recent streak
of a week and a half of above normal temperatures.

Dense fog shrouded the summit for much of the morning, reducing visibility
to 1/16th of a mile a times.  As the low stratus has lifted this afternoon,
the visibility has improved to only 9 miles, with plenty of thin fog and
haze still in the air.

The wind speed has been quite low today, not exceeding 10 mph since very
early this morning.

A brief thunderstorm late yesterday evening provided 0.04 inch of rainfall.
Periods of morning drizzle this morning added another 0.01 inch of rain.
 
Today's Observations:

7 A.M. 
Weather: Sky obscured by dense fog, stratus drifting over summit, heavy
dew all surfaces, very light drizzle ended at unknown time
Temperature: 65F; Dew Point: 65F; Wind: Calm
Sea-level pressure: 30.12 ins. Hg, rising
Visibility: 1/8 mile, variable 1/8 to 1/4 mile, visibility increasing,
dense fog
6-hr precip: Trace
24-hr precip: 0.05 inch
6-hr min. temp: 63F
BHO SA 1155 W3 X 1/8VF 199/65/65/0000/012/ STRA DRFTNG OVR SMT HVY DEW ALL
SFCS VSBY 1/8V1/4 INCRSNG WND CALM L-EUKN VRY LGT/ 8//// 51010 ASOS 70004
MANUAL 70005 MANUAL 6000/ 10065 20063

10 A.M. 
Weather: Overcast stratus, fog, stratus occasionally drifting over summit,
sun dimly visible, very light drizzle ended at unknown time
Temperature: 69F; Dew Point: 67F; Wind: Estimated NE at 3 kts,
Wind: Light and variable
Sea-level pressure: 30.12 ins. Hg, rising slightly
Visibility: 2 miles, N-ESE 1 mile, SE-SW 3 miles, fog
3-hr precip: Trace
BHO SA 1455 E3 OVC 2F 201/69/67/E0403/012/ STRA OCNLY DRFTNG OVR SMT
SUN DMLY VSBL VSBY N-ESE 1 SE-SW 3 WND LGT AND VRB L-EUKN PCPN VRY LGT/
8/6// 51002 MANUAL 6000/
 
1 P.M.
Weather: Broken stratocumulus, overcast stratus, thin fog, hazy 
Temperature: 70F; Dew Point: 66F; Wind: ENE at 4 kts,
Wind: Light and variable
Sea-level pressure: 30.12 ins. Hg, falling slightly 
Visibility: 9 miles, thin fog/haze
6-hour precip: Trace
6-hour max. temp: 71F
BHO SA 1755 E8 BKN 20 OVC 9 200/70/66/0604/012/ THN FG/HZ ALQDS WND LGT
AND VRB/ 8/8// 58001 MANUAL 6000/ 10071 20065
 
WEATHER SUMMARY FOR MONDAY, JULY 8, 2013

TEMPERATURE (DEGREES F)
MAX.....82     NORMAL.....80
MIN.....64     NORMAL.....63
MEAN....73     NORMAL.....72
 
DEPARTURE FROM 30-YEAR NORMAL.....................+1
TOTAL DEPARTURE FOR THE MONTH....................+57 [+6.9 DEGREES/DAY]
 
PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY................18 NE  AT  6:29 P.M.
                   AERO.....................20 NE  AT  6:29 P.M. *
                   ASOS.....................21 ENE AT  6:29 P.M.
                   DAVIS....................19 NNE AT  6:11 P.M. RMY 20
FASTEST MILE FOR YESTERDAY..................14 ENE AT  5:46 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...............15 ENE AT  6:29 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..............14 NE  AT  6:29 P.M.
AVERAGE WIND SPEED AND DIRECTION...........9.1 NE
                   ASOS....................8.8
                   DAVIS...................8.5 E [101 deg]
* last of several occurrences...

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.05   DEPARTURE...........-0.07
                         ASOS..............0.04
TOTAL PRECIPITATION FOR THE MONTH..........0.31   DEPARTURE...........-0.57
                         ASOS..............0.30
TOTAL PRECIPITATION FOR THE YEAR..........32.51   DEPARTURE...........+4.66
                         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  morning low temp: 63F; 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 9
HIGH 98F IN 1912
LOW 47F IN 1909
PRECIP 3.74 INS IN 1921
WIND 46 MPH NW IN 1992 

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

TODAY'S REPORT PREPARED BY: Sean Fankhauser and Mark Medlinskas