BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
  
DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, SEPTEMBER 25, 2009  
ALL TIMES ARE IN EASTERN STANDARD TIME

Today's observations:

7 A.M.   
Weather: Clear, few stratocumulus distant 
Temperature: 54F, Dew point: 44F, Wind: NW at 17G24 kts
Wind: Variable direction WSW to N
Sea-level pressure: 30.12 inches Hg, rising
Visibility: 60 miles
6-hour minimum temp: 51F
24-hour precipitation: 0.00
BHO SA 1155 CLR 60 201/54/44/3117G24/012/ 
FEW SC DSNT NE-SE AND W-NNW FEW CI SE-S-W WND 24V36/ 
8/505 51020 10055 20051

10 A.M. 
Weather: Scattered stratocumulus, cirrus
Temperature: 60F, Dew point: 43F, Wind: NW at 10G22 kts,
Wind: Direction variable WSW to N
Sea-level pressure: 30.19 inches Hg, rising
Visibility: 75 miles
BHO SA 1455 35 SCT 250 SCT 75 223/60/43/3210G22/019/ 
WND 24V01/ 8/501 51022

1 P.M.  
Weather: Broken stratocumulus, cirrus
Temperature: 60F, Dew point: 40F, Wind: NNW at 9G20 kts
Wind: Direction variable WSW to NNE
Sea-level pressure: 30.22 inches Hg, rising
Visibility: 80 miles
6-hourly max. temp: 63F  
BHO SA 1755 E50 BKN 250 BKN 80 233/60/40/3309G20/022/ 
WND 24V03/ 8/501 51010 10063 20054

WEATHER SUMMARY FOR THURSDAY, SEPTEMBER 24

TEMPERATURE (DEGREES F)
MAX.....77    NORMAL.....68
MIN.....57    NORMAL.....50
MEAN....67    NORMAL.....59

DEPARTURE FROM 30-YEAR AVERAGE...........+8
TOTAL DEPARTURE FOR THE MONTH............-8 [-0.5 DEGREES/DAY] 

HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............0  DEPARTURE.......-7
TOTAL HEATING UNITS FOR THE MONTH............76  DEPARTURE......-17
TOTAL HEATING UNITS FOR THE SEASON..........110  DEPARTURE......-14
TOTAL HEATING UNITS LAST SEASON TO DATE.....100  DIFFERENCE.....+10

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............25 SW  AT  1:26 A.M. *
                   AEROVANE..............22 SW  AT  1:18 A.M. *
                   ASOS..................24 WSW AT  1:02 A.M.     
                   DAVIS.................25 SW  AT  1:01 A.M.    
FASTEST MILE FOR YESTERDAY...............17 SSW AT  2:28 A.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE............17 SW  AT 12:43 A.M.    
MAXIMUM 2-MINUTE DAVIS AVERAGE...........19 SSW AT 12:21 A.M.    
AVERAGE WIND SPEED AND DIRECTION........7.8 WNW
                   ASOS.................7.7
                   DAVIS................8.4 W [262 DEG]
* last of several occurrences
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M... 0.00   DEPARTURE....-0.14
                         ASOS..............0.00
TOTAL PRECIPITATION FOR MONTH..............2.29   DEPARTURE....-1.00
                         ASOS..............2.33
TOTAL PRECIPITATION FOR THE YEAR..........37.06   DEPARTURE....+0.30
                         ASOS.............38.25

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 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

9/1  71/51/61/-6/0/773/98     17 NW 
9/2  76/54/65/-1/0/786/100    22 S
9/3  77/56/67/+1/0/587/75     19 SW
9/4  77/60/69/+3/0/764/98     18 NE
9/5  81/59/70/+5/0/591/76     25 NNW 
9/6  64/53/59/-6/0/743/96     31 NNE 
9/7  70/52/61/-4/0/709/92     20 WSW 
9/8  75/56/66/+1/0/369/48     18 WSW   
9/9  68/55/62/-2/0/352/46     36 NNE  AERO 33 MPH NNE 
9/10 65/53/59/-5/0/603/79     31 ENE
9/11 61/54/58/-6/0.49/000/00  30 NE
9/12 63/60/62/-1/1.74/000/00  30 NNE
9/13 76/58/67/+4/0.06/393/52  28 NW  
9/14 74/55/65/+2/0/699/93     22 WSW
9/15 75/56/66/+4/0/682/91     22 WNW
9/16 61/53/57/-5/T/060/08     31 NNE  AERO 29 MPH NNE 
9/17 60/49/55/-7/0/022/03     27 N    
9/18 71/47/59/-2/T/571/77     35 WSW  AERO 30 MPH WSW
9/19 65/45/55/-6/0/716/97     30 NW   AERO 28 MPH WNW 
9/20 71/45/58/-3/0/721/98     22 SW   
9/21 76/50/63/+3/0/703/96     20 S 
9/22 74/55/65/+5/0/124/17     27 SSW 
9/23 78/61/70/+10/145/20      35 SSW
9/24 77/57/67/+8/348/48       25 SW

9/25 our morning low temp: 51F; the normal low is now 50F

NEW DAILY RECORDS FOR SEPTEMBER 2009 TO DATE...
None.
  
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR SEPTEMBER 25
HIGH 87F IN 1970
LOW 31F IN 1950
PRECIP 2.68 INCHES IN 1961
PEAK GUST 63 MPH SSW IN 1991

RECORDS FOR SEPTEMBER 26
HIGH 91F IN 2007
LOW 36F IN 1905,1922,1978
PRECIP 3.84 INCHES IN 1888
PEAK GUST 54e MPH S IN 1977

TODAY'S REPORT PREPARED BY: Stephanie Radner