BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
  
DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, JULY 18, 2008     
ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED 
 
FIRST 90 DEGREE DAY IN JULY
 
The temperature on the summit of Great Blue Hill has 
reached 91 degrees F as of 2:00 PM EDT, making today 
the first 90+ degree day in July.  The last time we 
saw 90 degrees was on June 10 on the last day of a 
four day heatwave.
 
Today's observations:
 
8 A.M. EDT
Weather: Broken cirrostratus, broken cirrus, dark smoke
layer S-W-NE, top of inversion estimated 500 feet over 
city to the north
Temperature: 73F, Dew point: 65F,  Wind: SW at 6 kts 
Sea-level pressure: 30.06 inches Hg, rising
Visibility: 10 miles, hazy
6-hourly minimum temperature: 70F     
24-hourly rainfall: 0.00 in.
BHO SA 1155 E200 BKN 250 BKN 10 178/73/65/2206/006/ 
DRK K LYR S-W-NE TOP OF INVSN ESTMTD 5 HND OVER CTY N 
HAZY/ 8/002 53006 10073 20070
 
11 A.M. EDT
Weather: Scattered cirrostratus, scattered cirrus, 
few cumulus SW-NW
Temperature: 86F, Dew point: 64F,  Wind: SW at 7 kts, 
Wind: Direction variability S-W
Sea-level pressure: 30.04 inches Hg, falling
Visibility: 12 miles, hazy   
BHO SA 1455 220 SCT 250 SCT 12 172/86/64/2207/004/ 
FEW CU SW-NW HAZY WND 18V26/ 8/102 58006
 
2 P.M. EDT
Weather: Scattered cumulus, scattered cirrostratus,
thin broken cirrus
Temperature: 91F, Dew point: 63F,  Wind: WSW at 7 kts, 
Wind: Direction variability S-NW
Sea-level pressure: 30.00 inches Hg, falling
Visibility: 12 miles, hazy
6-hourly max. temp. 91F  
BHO SA 1755 50 SCT 220 SCT E250 BKN 12 159/91/63/2407/000/ 
HAZY WND 19V31/ 8/102 58013 10091 20073
 
WEATHER SUMMARY FOR THURSDAY, JULY 17
 
TEMPERATURE (DEGREES F)
MAX.....86    NORMAL.....82
MIN.....68    NORMAL.....62
MEAN....77    NORMAL.....72
 
DEPARTURE FROM 30-YEAR NORMAL.............+5 
TOTAL DEPARTURE FOR THE MONTH............+49 [+2.7 DEGREES/DAY]
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............20 SW  AT  3:23 A.M.     
                   AEROVANE.............18 SW  AT  3:23 A.M.       
                   ASOS.................18 WSW AT  3:24 A.M.      
                   DAVIS................21 SSW AT  1:46 A.M.  
FASTEST MILE FOR YESTERDAY..............14 SW  AT  3:21 A.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE...........14 WSW AT  3:22 A.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE..........16 SSW AT  2:03 A.M.      
                   AVERAGE............ 7.8 N  
                   ASOS................7.5  
                   DAVIS...............8.4 SSW [211 deg] 
 
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..........1.76   DEPARTURE......-0.30  
                         ASOS..............1.79   
TOTAL PRECIPITATION FOR THE YEAR..........26.76   DEPARTURE......-0.97    
                         ASOS.............29.17 #
# Includes erroneous ASOS precipitation data on 2/13/08.
 
PRELIMINARY CLIMATE SUMMARY FOR JULY 2008 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
7/1  83/66/75/+5/0.15/411/45     28 SSW   TSTM
7/2  84/61/73/+3/1.02/593/65     44 W     TSTM Small hail *
7/3  85/63/74/+4/T/793/87        45 SW    Aero 44 MPH SW
7/4  69/59/64/-6/0.22/018/02     25 NE
7/5  70/62/66/-5/0.01/000/00     17 E
7/6  81/65/73/+2/0/245/27        20 S
7/7  86/67/77/+6/0/563/62        21 S
7/8  89/69/79/+8/0/753/83        30 SSE  
7/9  88/70/79/+8/T/734/81        36 SSW  TSTM Aero 35 MPH SSW
7/10 82/65/74/+3/T/887/98        28 W    Aero 29 MPH W
7/11 83/61/72/0/0/759/84         17 NW   
7/12 82/65/74/+2/0/631/70        28 S  
7/13 81/66/74/+2/0/784/87        38 S    Aero 40 MPH S  
7/14 80/67/74/+2/0.36/468/52     23 W    TSTM 
7/15 87/67/77/+5/0/799/89        22 SSW
7/16 88/66/77/+5/0/.../..        22 SSE
7/17 86/68/77/+5/0/.../..        20 SW   Aero 18 MPH SW
 
7/18 morning low temp. 70F; our normal low now 62F
 
NEW DAILY RECORDS FOR JULY 
None to date...       
 
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: Stephanie Radner