BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 5, 2009 
ALL TIMES ARE IN EASTERN STANDARD TIME
 
MODERATE TO HEAVY RAIN LATE THIS MORNING
BRINGS ONE HALF INCH IN ONE HOUR AND 0.82 INCH
IN JUST 3 HOURS
 
The rain which began between 9 and 10 a.m. EDT
this morning became moderate to heavy for several
hours. We had almost a half inch in one hour and
and we measured a 6-hour total of 0.91 inch
by 2 p.m. after the rain had decreased in intensity
to light. Northeast winds were gusting 30 to
40 MPH with temperature stuck in the upper 40's
giving the feel of an early May nor'easter. 
 
Today's observations:
 
7 A.M.  
Weather: Overcast stratus fractus, higher nimbostratus
overcast occasionally visible, very light rain showers
occurring and began at 6:35 a.m. 
Temperature: 48F, Dew point: 48F, Wind: ENE  at 15G23 kts 
Sea-level pressure: 30.20 inches Hg, rising
Visibility: 10 miles, NW-E 6 miles, SE-SW 12 mile
thin fog
6-hour minimum temp: 48F
6-hour precip: trace
24-hour precipitation: 0.01
BHO SA 1155 E8 OVC 10RW- 228/48/48/0615G23/020/
HIER NS OVC OCNL VSB  VSBY NW-E 6 SE-SW 12 RB35
PCPN VRY LGT/ 8/72/ 51016 MANUAL 6000/
MANUAL 70001 10051 20048 
 
10 A.M.  
Weather: Obscurement with fog, light rain occurring
Temperature: 48F, Dew point: 48F, Wind: NE at 17G28 kts,
Wind: Peak wind NE @ 31 kts @ 9:31 a.m.,
Wind: direction variable NNE to E
Sea-level pressure: 30.19 inches Hg, falling
Visibility: 1/4 variable 1/8 mile to 3/4 mile in fog,
stratus drifting over summit 
BHO SA 1455 W3 X 1/4VR-F 224/48/48/0517G28/019/
STRA DRFTG OVR SMT CDNS VRBL VSBY 1/8V3/4
PK WND 0531/31 WND 02V09/ 8//// 58004 ASOS
60007 MANUAL 6009/ 
 
1 P.M.  
Weather: Obscurement with fog and light rain occurring
Temperature: 48F, Dew point: 48F, Wind: NE at 18G33 kts,
Wind: Peak wind NNE at 33 kts at 12:48 p.m.
Wind: direction variable N to E
Sea-level pressure: 30.15 inches Hg, falling
Visibility: 1/16 mile in heavy fog
6-hour maximum temp: 49F 
6-hour precip: 0.91 inch 
BHO SA 1755 W2 X 1/16R-F 211/48/48/0418G33/015/
PK WND 0333/48/ WND 36V08/ 8//// 58013 ASOS 60092
MANUAL 6091/ 10049 20047
 
WEATHER SUMMARY FOR MONDAY, MAY 4
 
TEMPERATURE (DEGREES F)
MAX.....64    NORMAL.....63
MIN.....48    NORMAL.....43
MEAN....56    NORMAL.....53
 
DEPARTURE FROM 30-YEAR NORMAL...........+3
TOTAL DEPARTURE FOR THE MONTH..........+21 [+5.1 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............9  DEPARTURE.......-3
TOTAL HEATING UNITS FOR THE MONTH............29  DEPARTURE......-22
TOTAL HEATING UNITS FOR THE SEASON.........5925  DEPARTURE.....-152
TOTAL HEATING UNITS LAST SEASON TO DATE....5690  DIFFERENCE....+235
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............17 SSW AT 12:09 A.M. 
                   AEROVANE.............15 SSW AT 12:09 A.M.  
                   ASOS.................16 SSW AT 12:09 A.M.  
                   DAVIS................17 SW  AT 12:35 A.M.
FASTEST MILE FOR YESTERDAY..............11 SW  AT 3:26 A.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...........12 SW  AT 3:29 A.M.   
MAXIMUM 2-MINUTE DAVIS AVERAGE..........12 SW  AT N/A
AVERAGE WIND SPEED AND DIRECTION.......6.3 SSE
                   ASOS................5.6 
                   DAVIS...............6.0 S [190 DEG]
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.01  DEPARTURE....-0.12
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.06  DEPARTURE....-0.46
                         ASOS..............0.05 
TOTAL PRECIPITATION FOR THE YEAR..........14.66  DEPARTURE....-3.80
                         ASOS.............15.73  
 
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 APRIL 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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
 
4/1  45/31/38/-3/0.13/0/015/02       24 SE    
4/2  52/39/46/+4/0.02/0/000/00       20 SSE       
4/3  58/45/52/+10/0.70//000/00       39 SSE   AERO 38 MPH SSE TSTM
4/4  51/38/45/+3/0.01/0/015/02       48 WSW   AERO 48 MPH WSW 
4/5  58/37/48/+5/0/0/551/71          40 W     AERO 37 MPH W
4/6  55/38/47/+4/1.42/0/047/006      42 SE    AERO 40 MPH SE  TSTM 
4/7  50/34/42/-1/T/0/109/14          36 WSW   AERO 35 MPH WSW
4/8  45/32/39/-5/0/0/149/19          33 SW    AERO 31 MPH SW
4/9  60/34/47/+3/0/0/692/88          36 SSW   AERO 33 MPH SSW
4/10 65/41/53/+9/0.18/0/544/69       37 SSW   AERO 35 MPH SSW 
4/11 44/33/39/-6/0.77/0.2/000/00     35 N     AERO 30 MPH N
4/12 43/29/36/-9/0/0/541/68          45 NW    AERO 43 MPH WNW
4/13 52/29/41/-4/0/0/734/92          38 W     AERO 35 MPH W
4/14 58/37/48/+2/0/0/696/87          25 E     
4/15 49/36/43/-3/0/0/650/81          35 NE    AERO 31 MPH NE
4/16 50/34/42/-4/0/0/806/100         29 NNE  
4/17 69/35/52/+5/0/0/695/86          37 W     AERO 33 MPH W
4/18 64/44/54/+7/0.05/0/170/21       28 W  
4/19 52/38/45/-2/0.03/0/773/95       33 NNE   AERO 28 MPH NNE
4/20 51/36/44/-4/0.10/0/196/24       43 E     AERO 39 MPH E
4/21 58/42/50/+2/0.95/0/000/00       43 E     AERO 43 MPH S
4/22 62/45/54/+5/0.16/0/296/36       28 S    
4/23 56/40/48/-1/0.01/0/627/76 *     43 W
4/24 70/40/55/+6/0/0/810/98          30 W
4/25 83/49/66/+16/T/0/647/78         29 S
4/26 88/56/72/+22/0/0/574/69         33 NE
4/27 72/49/61/+11/0/0/768/92         29 S
4/28 92/57/75/+24/0/0/704/84         37 SSW   AERO 36 MPH S
4/29 63/44/54/+3/T/0/823/98          35 NW    AERO 30 MPH NW TSTM
4/30 67/41/54/+2/T/0/717/85          37 S
 
* the sunshine total and % for 4/23 has been corrected
 
NEW DAILY RECORDS FOR APRIL 2009...
New record high maximum temperature for April 25 of 83F
surpasses 80F in 1942.
New record high maximum temperature for April 26 of 88F
surpasses 83F in 1908.
New record high minimum temperature for April 26 of 56F
surpasses 55F in 1985.
Maximum temperature of 92F for April 28 equals record
high maximum of 92F in 1990.
Minimum temperature of 57F for April 28 equals record
high minimum of 57F in 1935. 
 
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/.../..          37 SSW   AERO 37 MPH SSW
5/2 68/52/60/+8/0.05/.../..       32 WNW
5/3 64/48/56/+3/T/.../..          25 S
5/4 64/48/56/+3/../.../..         17 SSW
 
5/5 morning low temp: 48F; our normal low is now 44F
 
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 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976
 
RECORDS FOR MAY 6
HIGH 90F IN 1930
LOW 29F IN 1891
PRECIP 1.04 INCHES IN 1890
SNOWFALL TRACE IN 1917,1996
PEAK GUST 65 MPH SSE IN 1989
 
TODAY'S REPORT PREPARED BY: Robert Skilling