BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 11, 2009 
ALL TIMES ARE IN EASTERN STANDARD TIME
 
PARTLY SUNNY AFTER MOSTLY CLEAR THIS MORNING
WINDS MUCH DIMINISHED AFTER YESTERDAY'S
STRONG WINDS GUSTED PAST 40 MPH FROM THE WEST
 
Stratocumulus clouds have increased to a broken layer
this afternoon after mostly clear sky this morning. 
Winds have greatly diminished after yesterday, Sunday,
Mothers Day, was a very windy day.  Wind gusts were
reaching 35 to 45 MPH from the west througout the
daylight hours.  A peak gust to 53 MPH occurred
just before 9 a.m. EDT.
 
Today's observations:
 
7 A.M.  
Weather: Scattered stratocumulus, altocumulus distant
northwest thru east, altocumulus lenticular in the
vicinity past hour 
Temperature: 48F, Dew point: 37F, Wind: WNW at 11G19 kts,
Wind: direction variable west to northwest  
Sea-level pressure: 30.03 inches Hg, rising
Visibility: 60 miles, 75 miles NW
6-hour minimum temp: 41F
24-hour precipitation: 0.00
BHO SA 1155 28 SCT 120 SCT 60 171/48/37/2911G19/003/
SC FRMG ALQDS AC DSNT NW-E ACSL PST HR VCTY STN
VSBY NW 75 WND 26V31/ 8/530 51015 10048 20041
 
10 A.M.  
Weather: Clear, stratocumulus with cumuloform tops,
few altocumulus distant NE-E, cirrus/cirrostratus
later distant ESE-SSW  
Temperature: 56F, Dew point: 35F, Wind: NW at 7 kts.
Wind: direction variable west to north
Sea-level pressure: 30.04 inches Hg, steady
Visibility: 75 miles 
BHO SA 1455 CLR 75 172/56/35/3107/004/
SC CUFRM TOPS ALQDS FEW AC DSNT
NE-E DSNT ESE-SSW WND 28V01/
8/548 53001
 
1 P.M.  
Weather: Broken stratocumulus, altocumulus, cirrus and
cirrostratus, mostly clear distant NE-SE 
Temperature: 61F, Dew point: 37F, Wind: WNW at 7 kts,
Wind: direction W variable to N 
Sea-level pressure: 30.02 inches Hg, falling
Visibility: 75 miles
6-hour maximum temp: 63F  
BHO SA 1755 E50 BKN 120 BKN 250 BKN 75 166/61/37/3007/002
MSTLY CLR SKY DSNT NE-SE WND 26V35/
8/448 58006 10063 20048
 
WEATHER SUMMARY FOR SUNDAY, MAY 10, MOTHERS DAY
 
TEMPERATURE (DEGREES F)
MAX.....65    NORMAL.....65
MIN.....46    NORMAL.....45
MEAN....56    NORMAL.....55
 
DEPARTURE FROM 30-YEAR NORMAL...........+1
TOTAL DEPARTURE FOR THE MONTH..........+39 [+3.7 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............9  DEPARTURE.......-1
TOTAL HEATING UNITS FOR THE MONTH............76  DEPARTURE......-42
TOTAL HEATING UNITS FOR THE SEASON.........5972  DEPARTURE.....-172
TOTAL HEATING UNITS LAST SEASON TO DATE....5737  DIFFERENCE....+235
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............53 W   AT  7:53 A.M. 
                   AEROVANE.............48 W   AT  7:53 A.M. 
                   ASOS.................51 W   AT  7:54 A.M. 
                   DAVIS................48 WSW AT  9:52 A.M.
FASTEST MILE FOR YESTERDAY..............36 W   AT  7:56 A.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...........36 W   AT  7:55 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..........36 W   AT  7:59 A.M.
AVERAGE WIND SPEED AND DIRECTION......22.8 W
                   ASOS...............22.0
                   DAVIS..............21.5 W [260 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..........2.15  DEPARTURE....+0.90
                         ASOS..............2.14 
TOTAL PRECIPITATION FOR THE YEAR..........16.76  DEPARTURE....-2.44
                         ASOS.............17.82 
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE..... 0.0
TOTAL SNOWFALL FOR THE MONTH................0.0  DEPARTURE.....-0.1
TOTAL SNOWFALL FOR THE SEASON..............78.9  DEPARTURE.....18.8 
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2009 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
 
5/1  64/53/59/+7/T/000/00          37 SSW   AERO 37 MPH SSW
5/2  68/52/60/+8/0.05/263/31       32 WNW
5/3  64/48/56/+3/T/068/08          25 S
5/4  64/48/56/+3/0.01/009/01       17 SSW
5/5  52/44/48/-5/.../000/00        43 NNE   AERO 40 MPH NNE
5/6  63/43/53/-1/.../189/22        24 SSE  
5/7  68/49/59/+5/.../009/01        29 S    
5/8  75/52/64/+10/.../.../..       28 S
5/9  71/55/63/+8/.../.../..        31 W
5/10 65/46/56/+1/0/.../..          53 W     Aero 50 MPH W
 
5/11  morning low temp: 41F; our normal low is 45F
 
NEW DAILY RECORDS FOR MAY 2009...
NONE
 
DAILY EXTREMES
 
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 11
HIGH 90F IN 1993
LOW 28F IN 1900
PRE 1.28 INS IN 1957
SNOW 1.0 INS IN 1907 (LATEST MEASURABLE SNOW ON RECORD)
PEAK GUST 75e MPH NW IN 1945
 
RECORDS FOR MAY 12
HIGH 88F IN 2001
LOW 29F IN 1907
PRECIP 1.49 INCHES IN 1968
PEAK GUST 76 MPH S IN 1974
 
TODAY'S REPORT PREPARED BY: Robert Skilling