BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, SEPTEMBER 10, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Scattered stratocumulus, broken dense cirrus Temperature: 60F, Dew point: 52F, Wind: ENE at 10 kts Sea-level pressure: 30.44 inches Hg, rising Visibility: 25 miles, hazy 6-hour minimum temp: 53F BHO SA 1155 20 SCT E250 BKN 25 309/60/52/0610/044/ DENS CI HAZY INVSN PRSNT/ 8/506 53016 10060 20053 10 A.M. Weather: Scattered stratocumulus, overcast dense cirrus, breaks in overcast W-N-NE Temperature: 63F, Dew point: 49F, Wind: ENE at 14G22 kts Wind: Peak gust 27 kts ENE at 9:08 A.M. Wind: Variable direction N to E Sea-level pressure: 30.49 inches Hg, rising Visibility: 45 miles, light haze BHO SA 1455 30 SCT E250 OVC 45 324/63/49/0614G22/049/ DENS CI BRKS IOVC W-N-NE LGT HZ PK WND 0627/08 WND 36V10/ 8/507 51015 1 P.M. Weather: Scattered stratocumulus, broken cirrostratus, overcast cirrus, small breaks in overcast all quadrants Temperature: 63F, Dew point: 49F, Wind: ENE at 9 kts Wind: Varible direction N to ESE Sea-level pressure: 30.23 inches Hg, steady Visibility: 40 miles, light haze 6-hour max. temp: 65F BHO SA 1755 E35 BKN 220 BKN 250 OVC 40 324/63/49/0609/049/ SML BRKS IOVC ALQDS LGT HZ WND 35V11/ 8/507 54000 10065 20059 WEATHER SUMMARY FOR WEDNESDAY, SEPTEMBER 9 TEMPERATURE (DEGREES F) MAX.....68 NORMAL.....73 MIN.....55 NORMAL.....55 MEAN....62 NORMAL.....64 DEPARTURE FROM 30-YEAR AVERAGE...........-2 TOTAL DEPARTURE FOR THE MONTH............-9 [-1.2 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............3 DEPARTURE........0 TOTAL HEATING UNITS FOR THE MONTH............17 DEPARTURE.......-5 TOTAL HEATING UNITS FOR THE SEASON...........51 DEPARTURE.......-2 TOTAL HEATING UNITS LAST SEASON TO DATE......14 DIFFERENCE.....+37 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............36 NNE AT 12:56 P.M. AEROVANE..............33 NNE AT 12:54 P.M. ASOS..................33 NNE AT 12:54 P.M. DAVIS................ 35 NNE AT 12:56 P.M. FASTEST MILE FOR YESTERDAY...............23 NNE AT 12:56 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............22 NE AT 12:56 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 NNE AT 12:56 P.M. AVERAGE WIND SPEED AND DIRECTION.......13.3 NNE ASOS................12.5 DAVIS...............12.5 NNE [025 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..............0.00 DEPARTURE....-1.19 ASOS..............0.00 TOTAL PRECIPITATION FOR THE YEAR..........34.77 DEPARTURE....+0.11 ASOS.............35.92 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/.../.. 36 NNE 9/10 our morning low temp: 53F; the normal low is now 55F 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 10 HIGH 90F IN 1931,1989 LOW 41F IN 1956 PRECIP 5.60 INCHES IN 1999 (DAILY RECORD FOR SEPTEMBER) PEAK GUST 48 MPH NW IN 1972 RECORDS FOR SEPTEMBER 11 HIGH 93F IN 1983 LOW 37F IN 1917 PRECIP 5.23 INCHES IN 1954 (HURRICANE EDNA) PEAK GUST 101 MPH NW IN 1954 (HURRICANE EDNA) TODAY'S REPORT PREPARED BY: Stephanie Radner