BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, JULY 18, 2010 
ALL TIMES ARE IN EASTERN STANDARD TIME
 
2ND OFFICAL HEATWAVE OF JULY REACHED THIS AFTERNOON
...CONDITIONS MUCH DRIER
 
Persistent westerly winds and bright sunshine brought more
heat to the summit on Sunday. As of 2:00 PM EDT the maximum
recorded temperature was 90.2F, marking the third consecutive
day above 90 degrees and, thus, the second official heatwave of
this July. Moreover, Sunday marked the tenth 90-degree day for
the month moving it into a third place tie for most monthly
90-degree days on record. Preliminary research also shows
that July is on pace to become one of the warmest on record
and to have one of the highest average maximum temperatures.
Through the 17th, this July currently ranks second on each
of these lists. 
 
Despite this continued heat, conditions have become somewhat drier
and more comfortable today with dew points dipping into the upper 50s.

Warmest NWS mean temperature (July 1st-17th)

1) 78.5 in 1911
2) 77.1 in 2010
3) 74.8 in 1952
   74.8 in 1955
5) 74.6 in 1910
6) 74.4 in 1912
7) 74.3 in 1993

Warmest average maximum temperature (July 1st-17th)
 
1) 89.8 in 1911
2) 87.5 in 2010 
3) 86.1 in 1912
   86.1 in 1952
5) 85.4 in 1908
   85.4 in 1988
7) 85.1 in 1910

Greatest monthly number of 90-degree days, July
 
1) 14 in 1952
2) 10 in 1949
   10 in 1963
   10 in 2010 (through the 18th)
5) 9 in 1911 
6) 8 in 1983
   8 in 1988
 
Greatest monthly number of 90-degree days, all months
 
1) 14 in July, 1952
2) 13 in August, 2002
3) 10 in August, 1944
   10 in July, 1949
   10 in July, 1963
   10 in July, 2010 (through the 18th)
7) 9 in July, 1911
   9 in August, 1928
9) 8 in August, 1949
   8 in July, 1983
   8 in July, 1988
 
 
Today's observations: 
 
7 A.M.
Weather: Clear, few altocumulus all quadrants, hazy
Temperature: 75F, Dew point: 68F; Wind: W at 7 kts
Sea-level pressure: 29.82 inches Hg, rising
Visibility: 25 miles, hazy
6-hour minimum temp: 71F
BHO SA 1155 CLR 25 098/75/63/2409/982/ FEW AC ALQDS HAZY/
8/030 53007 10075 20071
 
10 A.M.
Weather: Scattered altocumulus, few small cumulus all
quadrants, hazy
Temperature: 86F, Dew point: 63F; Wind: W at 16G21 kts
Sea-level pressure: 29.82 inches Hg, falling
Visibility: 20 miles, hazy
BHO SA 1455 150 SCT 20 097/86/63/2616G21/982/
FEW SML CU ALQDS HAZY/ 8/130 58001
 
1 P.M.
Weather: Scattered cumulus, few cumulus fractus all
quadrants, hazy
Temperature: 89F, Dew point: 61F; Wind: W at 16G21 kts
Sea-level pressure: 29.81 inches Hg, falling
Visibility: 25 miles, hazy
6-hour maximum temp: 90F
BHO SA 1755 55 SCT 25 094/89/61/2616G23/981/
FEW CUFRA ALQDS HAZY/ 8/100 58003 10090 20075
 
WEATHER SUMMARY FOR SATURDAY, JULY 17
 
TEMPERATURE (DEGREES F)
MAX.....91     NORMAL.....82
MIN.....71     NORMAL.....62
MEAN....81     NORMAL.....72
 
DEPARTURE FROM 30-YEAR AVERAGE.................+9
TOTAL DEPARTURE FOR THE MONTH................+103 [+5.9 DEGREES/DAY]
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............25 SW  AT  4:36 P.M. *
                   AEROVANE..............27 SW  AT  4:14 P.M. *
                   ASOS..................26 SSW AT  4:16 P.M. 
                   DAVIS.................28 SSW AT  4:18 P.M. 
THE FASTEST MILE FOR YESTERDAY...........19 SSW AT  4:19 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE............20 SSW AT  4:20 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 SSW AT  4:20 P.M.
AVERAGE WIND SPEED AND DIRECTION.......12.7 SW
                   ASOS................11.7
                   DAVIS...............11.9 SW [224 DEG]
* last of several occurrences...
 
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..........0.48  DEPARTURE........-1.58
                         ASOS..............0.45
TOTAL PRECIPITATION FOR THE YEAR..........36.57  DEPARTURE........+8.84
                         ASOS.............36.27 **
** ASOS missing rainfall due to system failure on 6/24-25
 
PRELIMINARY CLIMATE SUMMARY FOR JULY 2010 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  74/53/64/-6/0.00/649/71   30 W   AERO 30 MPH W
7/2  80/54/67/-3/0.00/867/95   23 WNW
7/3  85/60/73/+3/0.00/821/90   20 SW
7/4  93/67/80/+10/0.00/492/54  31 W
7/5  94/70/82/+11/0.00/864/97  22 WNW
7/6  99/77/88/+17/0.00/746/82  25 NNW
7/7  91/73/82/+11/0.00/.../..  18 SE
7/8  89/69/79/+8/0.00/.../..   23 S
7/9  90/71/81/+10/0.01/.../..  28 S
7/10 89/68/79/+8/0.01/.../..   30 W    TSTM
7/11 86/67/77/+5/0.00/.../..   20 ENE 
7/12 90/68/79/+7/0.00/.../..   32 SSW  AERO 33 MPH SSW
7/13 91/71/81/+9/0.06/.../..   25 S  
7/14 77/65/71/-1/.../.../..    21 NE
7/15 78/64/71/-1/.../.../..    18 ENE
7/16 90/65/78/+6/0.08/.../..   30 W    AERO 33 MPH WNW TSTM
7/17 91/71/81/+9/0.00/.../..   25 SW
 
7/18 morning low temperature was 71F; the normal low is 62F
 
NEW DAILY RECORDS FOR JULY 2010 TO DATE:
7/6 - Maximum temperature of 99 degrees F; surpasses 98F set in 1911.
7/6 - Minimum temperature of 77 degrees F; surpasses 73F set in 2003.
7/7 - Minimum temperature of 73 degrees F; surpasses 72F set in 1908.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
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
 
RECORDS FOR JULY 19
HIGH 96F IN 1977, 1991
LOW 50F IN 1890
PRE 1.10 INS IN 1951
WIND 63 MPH SSW IN 1982
 
TODAY'S REPORT PREPARED BY: Eli Melaas