BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, JULY 22, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME
 
LOW CLOUDS BREAK UP AND ALLOW SOME SUNSHINE
YESTERDAY'S COOL AND WET WEATHER WAS VERY
UNUSUAL FOR A MID-LATE JULY DAY
 
Dense fog and low clouds early today have broken
up by early afternoon with temperatures rising
into and through the 70's.  Dew points are in
the middle 60's and we're now fully in a warm
and humid airmass.  Yesterday was unusually
cool for mid-late July with a daytime maximum
temperature of only 63F.  This was just below
the record low maximum for the date of 64F but
the early morning high was 66F so no new record
for 21 July.  The maximum for the 24 hours ending
at 8 a.m. this morning was that 63F.
Yesterday's rainfall didn't completely end till
very late last night with a final total of
0.62 inch.
 
Today's observations:
 
7 A.M.  
Weather: Obscurement with heavy fog
Temperature: 63F, Dew point: 63F, Wind: WNW at 4 kts
Sea-level pressure: 30.17 inches Hg, rising
Visibility: 1/16 mile, zero past hour
6-hour minimum temp: 61F
6-hourly rainfall: 0.00 inch
24-hourly rainfall: 0.58 inch 
BHO SA 1155 W2 X 1/16F 216/63/63/2904/017/
VSBY 0 PST HR/ 8//// 53014 ASOS 70056
MANUAL 70058 10063 20061
 
10 A.M.
Weather: Low overcast of stratus clouds
Temperature: 65F, Dew point: 63F, Wind: SW at 7 kts,
Wind: direction variability south to west-southwest 
Sea-level pressure: 30.18 inches Hg, rising slightly
Visibility: 40 miles, west-northwest 50 miles, NE 20 miles  
BHO SA 1455 E10 OVC 40 221/65/63/2207/018/
VSBY WNW 50 NE 20 WND 19V25/ 8/6// 51005
 
1 P.M.  
Weather: Scattered cumulus, broken stratocumulus,
broken cirrus 
Temperature: 73F, Dew point: 65F, Wind: WSW at 5 kts,
Sea-level pressure: 30.17 inches Hg, falling
Visibility: 50 miles, northeast 20 miles 
6-hourly max. temp: 73F
BHO SA 1755 24 SCT E30 BKN 250 BKN 50 218/73/65/2405/017/
FEW LWR CU FEW MDT CU VSBY NE 20 LGT HZ/ 8/801
58003 10073 20062 
 
WEATHER SUMMARY FOR TUESDAY, JULY 21
 
TEMPERATURE (DEGREES F)
MAX.....66    NORMAL.....82
MIN.....61    NORMAL.....63
MEAN....64    NORMAL.....72
 
DEPARTURE FROM 30-YEAR AVERAGE..........-8
TOTAL DEPARTURE FOR THE MONTH..........-93  [-4.6 DEGREES/DAY]
 
HEATING DEGREE DATA WILL RESUME IN SEPTEMBER
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............29 NNE AT  3:57 P.M. *  
                   AEROVANE..............27 NE  AT 11:45 A.M.   
                   ASOS..................29 NE  AT 11:57 A.M.     
                   DAVIS.................27 NNE AT 11:57 A.M.    
FASTEST MILE FOR YESTERDAY...............20 NNE AT  1:21 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............18 NNE AT  3:55 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE...........20 NNE AT  1:22 P.M. 
AVERAGE WIND SPEED AND DIRECTION.......11.5 NNE 
                   ASOS................11.0 
                   DAVIS...............11.0 NE [040 DEG]
 
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.58  DEPARTURE....+0.46
                         ASOS..............0.56
TOTAL PRECIPITATION FOR THE MONTH..........4.07  DEPARTURE....+1.53
                         ASOS..............4.12 
TOTAL PRECIPITATION FOR THE YEAR..........27.71  DEPARTURE....-0.50
                         ASOS.............28.77
 
PRELIMINARY CLIMATE SUMMARY FOR JULY 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
7/1  62/57/60/-10/0.51/000/00   25 NNE   TSTM
7/2  66/56/61/-9/1.00/000/00    29 SSW   TSTM
7/3  75/58/67/-3/T/283/31       23 WSW
7/4  77/59/68/-2/0/838/92       43 W      
7/5  78/54/66/-5/0/856/94       33 W     
7/6  79/60/70/-1/0/883/97       20 SSE
7/7  66/58/62/-9/0.73/027/03    28 SE    TSTM
7/8  67/56/62/-9/0.23/091/10    27 NNE   TSTM
7/9  66/55/61/-10/0/689/76      23 NE
7/10 76/54/65/-6/0/896/99       21 SW
7/11 77/56/67/-5/0.29/686/76    36 S
7/12 78/60/69/-3/0.33/650/72    30 SSW   TSTM
7/13 76/55/66/-6/0/802/89       32 SW 
7/14 75/56/66/-6/0/567/63       25 WNW
7/15 79/55/67/-5/0/826/92       30 WSW
7/16 77/62/70/-2/T/161/18       30 S
7/17 86/65/76/+4/0.01/582/65    24 ESE
7/18 84/66/75/+3/0.35/447/50    25 SSW   TSTM
7/19 80/62/71/-1/0/865/97       27 WSW
7/20 80/64/72/0/0/481/54        16 E
7/21 66/61/64/-8/0.62/000/00    29 NNE
 
7/22 our morning low temp: 61F; the normal low is now 63F
 
NEW DAILY RECORDS FOR JULY 2009 TO DATE...
NONE
 
DAILY EXTREMES
 
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR JULY 22
HIGH 99F IN 1926
LOW 52F IN 1890
PRECIP 1.73 INCHES IN 1900
PEAK GUST 55 MPH IN 1983
 
RECORDS FOR JULY 23
HIGH 99F IN 1952
LOW 51F IN 1923,1977
PRECIP 1.82 INCHES IN 1953
PEAK GUST 54e MPH S IN 1946
 
TODAY'S REPORT PREPARED BY: Robert Skilling