BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, JULY 13, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME
 
MORNING LOW TEMPERATURE ONLY 3F ABOVE RECORD 
A SECOND GREAT WEATHER EARLY JULY WEEKEND
TEMPERATURES CONTINUE ON COOL SIDE OF NORMAL
WEEKEND SHOWERS AND THUNDERSTORMS SATURDAY NIGHT...
AVERAGE MAXIMUM TEMP SINCE JUN 1 LOWEST ON RECORD...
NO TEMPERATURES OF 80 OR HIGHER FROM JUNE 1 TO
JULY 12 FOR FIRST TIME ON RECORD...
 
The long period of cool summer weather goes on
and this morning's low of 55F was only 3 degrees
above the record low for this date!  There have
been no above normal temperature days for two
weeks and two days and today will continue that
trend. The day features lots of bright sunshine with
temperatures in the mid-70's and dew points way down
in the mid to upper 40's.  Visibility was up to
75 miles by early afternoon.
The second weekend of July brought sunny, pleasantly
warm and dry weather and follows the equaly nice
Independence Day weekend weather.
Temperatures again reached highs in the upper 70's but
we continue on without any 80-degree weather since 80F
on 24 May. The average maximum temperature was recently
reported to have been at all-time record low values
from 1 June through 9 July at weather stations across
southern New England.  
At the Observatory, there have been no maximum
temperatures of 80 or higher from June 1 to July 12.  
This is the first time this has occurred on our record 
dating back to 1885. The average maximum temperature
over that 42-day period, 69.2 deg F, is the coldest
on record and just below 69.4 measured in 1916. 
A period of showers and thunderstorms late Saturday
night into early Sunday morning left 0.62 inch of rain
and the monthly total of 3 inches is now an inch and
a half above normal.
 
Today's observations:
 
7 A.M.  
Weather:  Clear, few stratocumulus distant E-SE
Temperature: 62F, Dew point: 51F, Wind: W at 7 kts
Sea-level pressure: 29.89 inches Hg, rising 
Visibility: 60 miles, 70 miles to the northwest
6-hour minimum temp: 55F
24-hour precipitation: 0.00 inch
BHO SA 1155 CLR 60 121/62/51/2707/989/
FEW SC DSNT E-SE VSBY NW 70/ 8/500
53007 10062 20055
 
10 A.M.  
Weather: Clear, cumulus fractus and cumulus forming
all quadrants 
Temperature: 71F, Dew point: 46F, Wind: W at 12G22 kts,
Wind: direction variable SW to WNW 
Sea-level pressure: 29.88 inches Hg, rising slightly
Visibility: 70 miles
BHO SA 1455 CLR 70 118/71/46/2712G22/988/
CUFRA/CU FRMG ALQDS WND 23V30/ 8/100 55003
 
1 P.M.  
Weather: Scattered cumulus, moderate cumulus, altocumulus
cumulogenitus 
Temperature: 74F, Dew point: 47F, Wind: WSW at 14G21 kts,
Wind: direction variable SSW to W
Sea-level pressure: 29.85 inches hg, falling
Visibility: 75 miles 
6-hourly max. temp. 75F
BHO SA 1755 50 SCT 70 SCT 85 SCT 75 110/74/47/2514G21/985/
MDT CU ACCU WND 21V28/ 8/260 58008 10075 20062
 
WEATHER SUMMARY FOR SUNDAY, JULY 12
 
TEMPERATURE (DEGREES F)
MAX.....78    NORMAL.....81
MIN.....60    NORMAL.....62
MEAN....69    NORMAL.....72
 
DEPARTURE FROM 30-YEAR NORMAL...........-3
TOTAL DEPARTURE FOR THE MONTH..........-72  [-6.2 DEGREES/DAY]
 
HEATING DEGREE DATA WILL RESUME IN SEPTEMBER
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............30 SSW AT  1:18 A.M. *
                   AEROVANE..............28 SSW AT  1:13 A.M. *
                   ASOS..................28 SSW AT  1:19 A.M.
                   DAVIS.................31 SSW AT  1-2  A.M. #
FASTEST MILE FOR YESTERDAY...............22 SSW AT  3:12 A.M. * 
MAXIMUM 2-MINUTE ASOS AVERAGE............22 SSW AT  1:20 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 SSW AT  1-2  A.M. #
AVERAGE WIND SPEED AND DIRECTION.......13.0 W
                   ASOS................12.2
                   DAVIS...............12.8 SW [230 DEG]
* last of several occurrences
# within the hour, minute not available
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE....-0.12
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........3.09  DEPARTURE....+1.63
                         ASOS..............3.15 
TOTAL PRECIPITATION FOR THE YEAR..........26.73  DEPARTURE....-0.40
                         ASOS.............27.80
 
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   AERO 25 MPH 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/.../..    27 NNE   TSTM
7/9  66/55/61/-10/0/.../..      23 NE
7/10 76/54/65/-6/0/.../..       21 SW
7/11 77/56/67/-5/.../.../..     36 S
7/12 78/60/69/-3/.../.../..     30 SSW   AERO 28 MPH TSTM
 
7/13 our morning low temp. 55F; the normal low is now 61F 
 
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 13
HIGH 95F IN 1894
LOW 52F IN 1888, 1895, 1939, 1973
PRECIP 3.54 INS IN 1996
WIND 55 MPH SE IN 1996
 
RECORDS FOR JULY 14
HIGH 98F IN 1952
LOW 51F IN 1895, 1937
PRECIP 1.97 INS IN 1960
WIND 110e MPH NW IN 1942 [RECORD FOR MONTH]
 
TODAY'S REPORT PREPARED BY: Robert Skilling