BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 20, 2006  
ALL TIMES ARE IN EASTERN STANDARD TIME
 
LAST NIGHT'S RAINFALL TOTALED 0.90 INCH
ONE BIG DOWNPOUR BROUGHT A HALF INCH IN HALF HOUR
 
Close to half an inch of rain fell during a downpour 
between midnight and 12:30 a.m. EDT.  About two thirds
of an inch fell in a 45 minute period ending 12:30 a.m. 
All of the total rainfall of 0.90 inch fell in a six hour
period between 9 p.m. and 3 a.m.
 
Today's observations:
                           
7 A.M.
Weather: Broken dense cirrus clouds clearing from west  
Temperature: 56F, Dew point: 53F, Wind: WNW at 12 kts 
Sea-level pressure: 29.63 ins. and rising                   
Visibility: 30 miles, 55 miles W-NW
6-hourly min. temp. 55 deg. 
24-hourly rainfall: 0.90 inch
 
BHO SA 1155 E200 BKN 220 BKN 30 033/56/53/2912/963/ 
CLR SKY/LINE OF CLRG XTDNG SSW-N MOVG E DENSE CI ALQDS 
VSBY W-NW 55 E-S 15/ 8/002 53005 ASOS 60011 MANUAL 6011/ 
ASOS 70089 MANUAL 70090 10061 20055 
 
10 A.M.
Weather:  Clear with high clouds east and few cu forming west
Temperature: 64F, Dew point: 50F, Wind: WNW at 10G18 kts   
Sea-level pressure: 29.64 inches Hg, falling                      
Visibility: 60 miles, 70 to NW
 
BHO SA 1455 CLR 60 037/64/50/2910G18/964/ 
FEW CUFRA/SML CU FRMG SW-NW CI/DENSE CI 
DSNT NNE-S MOVG E VSBY NW 70 WND 25V31/ 
8/102 50004 
 
1 P.M.
Weather: Clear, cumulus, dense cirrus distant NE-SE
Temperature: 69F, Dew point: 50F, Wind: W at 12 kts
Sea-level pressure: 29.63 inches Hg, falling
Visibility: 65 miles NW 70 miles 
6-hourly max. temp. 70 deg.
 
BHO SA 1755 CLR 65 032/69/50/2612/963/ CU ALQDS 
DENSE CI DSNT NE-SE VSBY NW 70/ 
8/102 58005 10070 20056 
  
WEATHER SUMMARY FOR TUESDAY, SEPTEMBER 19 
 
TEMPERATURE (DEGREES F)
MAX.....79   NORMAL.....70 
MIN.....61   NORMAL.....52   
MEAN....70   NORMAL.....61   
DEPARTURE FROM 30-YEAR NORMAL........+9
TOTAL DEPARTURE FOR THE MONTH.......+ 2 (-0.1 DEGREE/DAY)
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.........30 S   AT  2:28 P.M.     
                   AEROVANE..........29 S   AT  2:28 P.M.           
                   ASOS..............29 S   AT  2:28 P.M.    
                   DAVIS.............33 S   AT  2:28 P.M. 
FASTEST MILE FOR YESTERDAY...........22 S   AT  2:46 P.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE.......21 S   AT  2:47 P.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE........22 S   AT  2:51 P.M.    
AVERAGE WIND SPEED AND DIRECTION....13.8 S  
                   ASOS.............14.5 n/a
                   DAVIS............12.9 S [180 deg]
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.90   DEPARTURE....+0.76   
                         ASOS..............0.89
TOTAL PRECIPITATION FOR THE MONTH..........1.75   DEPARTURE....-0.84 *
                         ASOS..............1.72
TOTAL PRECIPITATION FOR THE YEAR..........45.31   DEPARTURE....+9.25 *
                         ASOS.............43.95
 
* monthly and yearly totals corrected [added 0.01] and departures 
  corrected accordingly [see note below about daily precip.]
 
PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 2006......CALENDAR DAY DATA
DATA REPORTED:
DATE  MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
 
AERO: Aerovane recording wind system when significant
TSTM: Thunderstorm day
....: Data not yet available
 
9/1  68/57/63/-4/0/442/56      29 ENE   
9/2  63/58/61/-5/T/000/00 **   45 ENE  Aero 42 MPH ENE TD ERNESTO
9/3  68/58/63/-3/0.44/000/00   39 E    Aero 37 MPH E 
9/4  73/56/65/-1/0/519/66      31 WSW  Aero 30 MPH WSW   
9/5  71/56/64/-1/0.11/168/22   18 W 
9/6  73/59/66/+1/0/194/25      17 WSW
9/7  73/58/66/+1/0/723/94      17 S     
9/8  78/59/69/+4/0/631/82      22 SW   
9/9  82/61/72/+8/T/682/89      24 SSW    
9/10 65/51/58/-6/0/497/65      27 NE
9/11 63/47/55/-9/0/731/96      32 NE    
9/12 64/45/55/-8/0/735/97      28 NNE 
9/13 64/48/56/-7/T/119/16      23 SSE
9/14 70/56/63/0/0.30/0/0  **   24 SSE
9/15 69/59/64/+2/T/.../..      23 NE  
9/16 76/57/67/+5/0/.../..      18 N
9/17 79/58/69/+7/0/.../..      17 SE 
9/18 80/59/70/+9/0/.../..      24 S
9/19 79/61/70/+9/0.77/525/71   30 S 
 
9/20 morning low temp. 55 deg; normal now 52
     morning rainfall: 0.13 inch
** 0.01 added to previously reported total of 0.29 for 14th  
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR SEPTEMBER 20
HIGH 90 IN 1983
LOW 34 IN 1979
PRE 4.57 INS IN 1899
WIND 44 MPH NE IN 1972
 
RECORDS FOR SEPTEMBER 21
HIGH 91 IN 1895
LOW 35 IN 1929, 1956, 1962
PRE 5.58 INS IN 1961 (HURRICANE ESTHER; RETURNED AS TS SEPT 25-26TH)
WIND 186 MPH S IN 1938 (GREAT NEW ENGLAND HURRICANE; CALCULATED GUST, STATION RECORD
 
TODAY'S REPORT BY: Robert Skilling