BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, MAY 31, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Scattered cirrus Temperature: 65F, Dew point: 44F, Wind: SSE at 11 kt Sea-level pressure: 29.77 inches Hg, falling Visibility: 60 miles 6-hour minimum temp: 57F BHO SA 1155 200 SCT 60 083/65/44/1611/977/ CLR DSNT N-NE WND BACKING HAZY/ 8/005 56003 10065 20057 10 A.M. Weather: Scattered cirrus Temperature: 72F, Dew point: 47F, Wind: SSE at 14G20 kt Sea-level pressure: 29.75 inches Hg, falling Visibility: 40 miles; hazy BHO SA 1455 200 SCT 40 074/72/47/1614G20/975/ CLR W-N HAZY/ 8/008 58009 1 P.M. Weather: Scattered stratocumulus; scattered altocumulus; scattered cirrus Temperature: 76F, Dew point: 46F, Wind: SSE at 20G26 kt Sea-level pressure: 29.66 inches Hg, falling Visibility: 20 miles 6-hour maximum temp: F BHO SA 1755 30 SCT 180 SCT 200 SCT 20 045/76/46/1520G26/966/ HAZY PK WND 1827/1737/ 8/241 58029 10077 20065 WEATHER SUMMARY FOR SATURDAY, MAY 30 TEMPERATURE (DEGREES F) MAX.....76 NORMAL.....71 MIN.....59 NORMAL.....51 MEAN....68 NORMAL.....61 DEPARTURE FROM 30-YEAR NORMAL...........+7 TOTAL DEPARTURE FOR THE MONTH..........+44 [+1.3 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............0 DEPARTURE.......-5 TOTAL HEATING UNITS FOR THE MONTH...........222 DEPARTURE......-44 TOTAL HEATING UNITS FOR THE SEASON.........6118 DEPARTURE.....-174 TOTAL HEATING UNITS LAST SEASON TO DATE....5901 DIFFERENCE....+217 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............32 WSW AT 3:43 P.M. AEROVANE..............28 WSW AT 3:43 P.M. ASOS..................30 W AT 3:43 P.M. DAVIS.................32 WSW AT 3:42 P.M. FASTEST MILE FOR YESTERDAY...............24 WSW AT 3:33 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............22 W AT 3:44 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 W AT 2:31 P.M. AVERAGE WIND SPEED AND DIRECTION........9.8 W ASOS.................9.7 DAVIS................9.9 W [265 DEG] * Last of several occurrences. 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..........3.86 DEPARTURE....+0.21 ASOS..............3.85 TOTAL PRECIPITATION FOR THE YEAR..........18.47 DEPARTURE....-3.13 ASOS.............19.53 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/-5/0.95/000/00 43 NNE AERO 40 MPH NNE 5/6 63/43/53/-1/0.40/189/22 24 SSE 5/7 68/49/59/+5/0.60/009/01 29 S 5/8 75/52/64/+10/0/690/80 28 S 5/9 71/55/63/+8/0.14/104/12 31 W TSTM 5/10 65/46/56/+1/0/840/97 53 W Aero 50 MPH W 5/11 63/41/52/-3/0/781/90 24 WNW 5/12 63/45/54/-2/0/696/80 22 ENE 5/13 70/45/58/+2/0/732/84 31 SSE AERO 29 MPH SSE 5/14 62/47/55/-2/0.10/166/19 53 S AERO 52 MPH S 5/15 76/54/65/+8/0/474/54 38 S AERO 38 MPH S 5/16 68/54/61/+4/T/457/52 35 S AERO 35 MPH S 5/17 61/49/55/-2/0.09/009/01 35 WNW AERO 33 MPH WNW 5/18 53/42/48/-10/0.04/168/19 27 NE 5/19 70/42/56/-2/0/813/92 28 S 5/20 82/49/66/+8/0/771/87 31 SSW 5/21 89/59/74/+15/0/870/98 37 S AERO 34 MPH S 5/22 87/59/73/+14/0/739/83 31 N 5/23 65/50/58/-1/T/428/48 28 NE 5/24 80/50/65/+5/1.07/536/60 25 WNW TSTM TRACE DIME SIZE HAIL 5/25 76/51/64/+4/0/868/97 32 N 5/26 58/46/52/-8/0/601/67 28 NNE 5/27 52/43/48/-13/0.16/000/00 23 E AERO 19 MPH E 5/28 48/45/47/-14/0.03/000/00 28 NE AERO 25 MPH NNE 5/29 63/48/56/-5/..../000/00 17 NE 5/30 76/59/68/+7/..../.../.. 32 WSW NEW DAILY RECORDS FOR MAY 2009... 5/14: RECORD PEAK WIND GUST 53 MPH S; surpasses previous record of 50 MPH SW in 1976 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 31 HIGH 92F IN 1944,1987 LOW 35F IN 1961 PRECIP 5.02 INS 1984 (RECORD FOR MAY) PEAK GUST 54e MPH WNW IN 1945 RECORDS FOR JUNE 1 HIGH 90F IN 1937 LOW 36F IN 1945 [Record for month] PRECIP 2.28 INS IN 1992 PEAK GUST 51e MPH SE IN 1952 TODAY'S REPORT PREPARED BY: Andrew Hoell