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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, JULY 17, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME
 
PLEASANT, DRY WEATHER CONTINUES TODAY
 
For the second morning in a row, the low temperature fell to a cool 56F here
at the summit, well below the average of 63F.  Yesterday remained cool all day,
with a high of only 72F, making it the coolest day of the month so far.  Today,
we have warmed to 78F.  Dew points have also remained comfortable, in the mid
50s for most of the day, indicating dry air.  Winds have been light and
variable, averaging under 5mph since 7AM.  High clouds have increased in
coverage during the day, creating near overcast conditions by mid-afternoon. 
These clouds have been filtering, but not completely blocking, the sunshine. 
A full solar halo has also been observed.  A warm front should move through the
region tomorrow, opening the door for another round of warm, humid conditions.
 
Today's Observations:

7 A.M.
Weather: Scattered cirrus, thin scattered cirrus, smoke layer along horizon
all quadrants except NE-E
Temperature: 64F; Dew Point: 56F; Wind: estimated NE at 5 kts,
Wind: Light
Sea-level pressure: 30.14 ins. Hg, rising
Visibility: 70 miles
6-hr Max temp: 64F
6-hr Min temp: 56F
24-hr precip: none
BHO SA 1155 250 SCT 300 -SCT 70 205/64/56/E0505/014/
K LYR ALG HRZN ALQDS XCPT NE-E WND LGT/ 8/001 52011 10064 20056
 
10 A.M.
Weather: Broken cirrus (partially thin), few cumulus and cumulus fractus
ENE-SW. lower cirrus distant S-WNW, thin smoke layer above horizon N-NE
Temperature: 73F; Dew Point 55F; Wind: estimated WSW at 3 kts,
Wind: Light
Sea-level pressure: 30.14 ins. Hg, about steady
Visibility: 60 miles, light distant haze
BHO SA 1455 E250 BKN 60 208/73/55/E2403/014/ FEW CU/CUFRA ENE-SW
CI LYR PRTLY THN LWR CI DSNT S-WNW THN K LYR ABV HRZN N-NE
LGT DSNT HZ WND LGT/ 8/101 51003
 
1 P.M.
Weather: Broken cirrostratus, broken cirrus, few cumulus all quadrants except
NE, full solar halo
Temperature: 78F; Dew Point: 55F; Wind: estimated SSW at 4 kts,
Wind: Light and variable
Sea-level pressure: 30.10 ins. Hg, steady then falling
Visibility: 60 miles, light distant haze
6-hr Max temp: 78F
6-hr Min temp: 64F
BHO SA 1755 E200 BKN 250 BKN 60 194/78/55/E2104/010/ FEW CU ALQDS XCPT NE
SOLAR HALO LGT DSNT HZ WND L/V/ 8/107 58014 10078 20064
 
SUMMARY FOR THURSDAY, JULY 16, 2015
  
TEMPERATURE (DEGREES F)
MAX.....72   NORMAL.....81
MIN.....56   NORMAL.....63
MEAN....64   NORMAL.....72

DEPARTURE FROM 30-YEAR NORMAL........................-8
TOTAL DEPARTURE FOR THE MONTH........................+5 [+0.1 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY...............0   DEPARTURE..........-7
TOTAL COOLING UNITS FOR THE MONTH.............109   DEPARTURE..........+2
TOTAL COOLING UNITS FOR THE SEASON............247   DEPARTURE.........+11
TOTAL COOLING UNITS LAST SEASON TO DATE.......251   DIFFERENCE.........-4

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY...................25   NNE  AT   9:00 A.M. *               
                   ASOS........................26   NNE  AT  12:28 A.M.
                   DAVIS.......................N/A                     RMY 24
FASTEST MILE FOR YESTERDAY.....................16   NNE  AT  12:26 A.M.         
MAXIMUM 2-MINUTE ASOS AVERAGE..................17   NNE  AT  12:29 A.M.                 
MAXIMUM 2-MINUTE DAVIS AVERAGE.................16   N    AT  12:29 A.M.         
AVERAGE WIND SPEED AND DIRECTION...............8.8  NNE
                   ASOS........................8.9
                   DAVIS.......................8.0  NE  [044 deg.]
* Last of several occurrences...
 
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...........2.82  DEPARTURE.....+0.89
                         ASOS...............2.85
TOTAL PRECIPITATION FOR THE YEAR...........27.09  DEPARTURE.....-1.81
                        ASOS...............N/A ***
*** ASOS annual total not available due to erroneous readings

PRELIMINARY CLIMATE SUMMARY FOR JULY CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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
 
7/1  80/63/72/+2/0.59/.../..               30 SSE RMY 33  TSTM
7/2  78/60/69/-1/0.00/.../..               23 WNW RMY N/A
7/3  79/58/69/-2/0.00/867/95               17 SSW RMY 17
7/4  74/61/68/-3/T/109/12                  16 S   RMY N/A
7/5  82/58/70/-1/0.00/865/95               20 WSW RMY 20 
7/6  85/64/75/+4/0.00/755/83               20 S   RMY 21
7/7  84/65/75/+4/0.02/445/49               35 S   RMY 40
7/8  87/68/78/+6/T/372/41                  23 NE  RMY N/A
7/9  73/61/67/-5/..../390/43               24 NE  RMY 25
7/10 80/59/70/-2/..../535/59               18 W   RMY N/A TSTM
7/11 84/61/73/+1/0.00/868/96               21 NW  RMY 19
7/12 88/67/78/+6/0.00/.../..               20 W   RMY 17
7/13 82/66/74/+2/0.00/.../..               21 E   RMY 20
7/14 81/64/73/+1/..../.../..               25 S   RMY 27
7/15 84/61/73/+1/..../.../..               24 ENE RMY 26
7/16 72/56/64/-8/0.00/.../..               25 NNE RMY 24
 
7/17 low since midnight is 56F; normal low is now 63F

DAILY RECORDS FOR JULY 2015
 
7/10- NEW RECORD DAILY PRECIPITATION PENDING OF X.XX in 2015
surpasses previous record of 1.68 in. in 1933

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR JULY 17
HIGH 96F IN 1999
LOW 47F IN 1892
PRECIP 1.39 INS IN 1989
WIND 46 MPH WNW IN 1971
 
RECORDS FOR JULY 18
HIGH 96F IN 1991, 1999
LOW 54F IN 1892, 1956, 1971
PRECIP 1.65 INS IN 2000
WIND 43e MPH SW IN 1949
 
TODAY'S REPORT PREPARED BY: Jonathan O'Brien