BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, MAY 8, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Clear, few altocumulus NW-N, distant cirrus all quadrants Temperature: 57F, Dew point: 53F, Wind: WSW at 5 kts Sea-level pressure: 29.82 inches Hg, rising Visibility: 60 miles 6-hour minimum temp: 52F 24-hour precipitation: 0.04 ins. BHO SA 1155 CLR 60 097/57/53/2505/982/ FEW AC NW-N DSNT CI ALQDS THN K LYR N-NE AND SE-SW/ 8/031 51014 MANUAL 70004 ASOS 70004 10057 20052 10 A.M. Weather: Scattered altocumulus, thin scattered cirrus, few stratocumulus distant E-S Temperature: 67F, Dew point: 48F, Wind: SSW at 5 kts Wind: Light and variable Sea-level pressure: 29.81 inches Hg, rising Visibility: 30 miles, hazy BHO SA 1455 150 SCT 250 -SCT 30 094/67/48/2005/981/ FEW SC DSNT E-S WND L/V HAZY/ 8/531 50003 1 P.M. Weather: Overcast stratocumulus Temperature: 72F, Dew point: 48F, Wind: SW at 11 kts Sea-level pressure: 29.78 inches Hg, falling Visibility: 25 miles, hazy 6-hour maximum temp: 73F BHO SA 1755 E50 BKN 70 OVC 25 086/72/48/2311/978/ HAZY WND 20V27/ 8/8// 55008 10073 20057 WEATHER SUMMARY FOR THURSDAY, MAY 7 TEMPERATURE (DEGREES F) MAX.....68 NORMAL.....64 MIN.....49 NORMAL.....44 MEAN....59 NORMAL.....54 DEPARTURE FROM 30-YEAR NORMAL...........+5 TOTAL DEPARTURE FOR THE MONTH..........+20 [+2.7 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............6 DEPARTURE.......-5 TOTAL HEATING UNITS FOR THE MONTH............64 DEPARTURE......-22 TOTAL HEATING UNITS FOR THE SEASON.........5960 DEPARTURE.....-152 TOTAL HEATING UNITS LAST SEASON TO DATE....5708 DIFFERENCE....+252 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............29 S AT 8:56 A.M. AEROVANE.............27 S AT 12:34 P.M. ASOS.................28 SSW AT 12:35 P.M. DAVIS................30 S AT 12:34 P.M. FASTEST MILE FOR YESTERDAY..............19 S AT 4:23 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE...........20 S AT 4:27 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........21 S AT 9:01 A.M. AVERAGE WIND SPEED AND DIRECTION......11.8 S ASOS...............11.5 DAVIS..............11.2 S [172 DEG] * last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.04 DEPARTURE....-0.08 ASOS..............0.04 TOTAL PRECIPITATION FOR THE MONTH..........2.01 DEPARTURE....+1.12 ASOS..............2.00 TOTAL PRECIPITATION FOR THE YEAR..........16.62 DEPARTURE....-2.22 ASOS.............17.68 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 AERO 22 MPH S 5/7 68/49/59/+5/.../009/01 29 S AERO 27 MPH S 5/8 morning low temp: 52F; 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 8 HIGH 89F IN 2000 LOW 29F IN 1956 PRECIP 1.48 INCHES IN 1886 SNOWFALL TRACE IN 1898, 1947 PEAK GUST 68e MPH NNW IN 1943 RECORDS FOR MAY 9 HIGH 93F IN 2000 LOW 31F IN 1947 PRECIP 2.72 INCHES IN 1954 SNOWFALL 5.0 INS IN 1977 (RECORD FOR MAY) PEAK GUST 70e MPH NE IN 1977 TODAY'S REPORT PREPARED BY: Stephanie Radner