BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, OCTOBER 1, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Broken altocumulus, overcast cirrus, distant stratocumulus all quadrants except NW-NE Temperature: 42F, Dew point: 39F, Wind: WSW at 9 kts Sea-level pressure: 29.96 inches Hg, rising Visibility: 80 miles 6-hour minimum temp: 39F 24-hour precipitation: 0.00 inch BHO SA 1155 E110 BKN 250 OVC 80 145/42/39/2409/996/ DSNT SC ALQDS XCPT NW-NE 8/541 51014 10042 20039 10 A.M. Weather: Scattered stratocumulus, broken altocumulus, overcast cirrus Temperature: 53F, Dew point: 39F, Wind: W at 9 kts Wind: Direction variable from S to WNW Sea-level pressure: 29.96 inches Hg, rising Visibility: 80 miles BHO SA 1455 50 SCT E80 BKN 250 BKN 80 146/53/39/2609/996/ WND 19V30/ 8/531 50001 1 P.M. Weather: Overcast stratocumulus with breaks N-E-S Temperature: 53F, Dew point: 39F, Wind: WSW at 8 kts Wind: Direction variable from SSW to NW Sea-level pressure: 29.95 inches Hg, falling Visibility: 80 miles 6-hour max. temp: 54F BHO SA 1755 E43 OVC 80 141/53/39/2508/995/ BRKS IOVC N-E-S WND 20V31/ 8/500 58005 10054 20042 WEATHER SUMMARY FOR WEDNESDAY, SEPTEMBER 30 TEMPERATURE (DEGREES F) MAX.....60 NORMAL.....66 MIN.....42 NORMAL.....48 MEAN....51 NORMAL.....57 DEPARTURE FROM 30-YEAR AVERAGE...........-6 TOTAL DEPARTURE FOR THE MONTH...........-14 [-0.7 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............14 DEPARTURE.......+6 TOTAL HEATING UNITS FOR THE MONTH...........123 DEPARTURE......-15 TOTAL HEATING UNITS FOR THE SEASON..........157 DEPARTURE......-12 TOTAL HEATING UNITS LAST SEASON TO DATE.....116 DIFFERENCE.....+41 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............27 WSW AT 1:23 P.M. * AEROVANE..............25 W AT 3:50 P.M. ASOS..................25 WNW AT 3:50 P.M. DAVIS.................26 W AT 3:47 P.M. FASTEST MILE FOR YESTERDAY...............18 WSW AT 2:10 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............18 W AT 3:51 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........19 W AT 3:51 P.M. AVERAGE WIND SPEED AND DIRECTION.......11.3 WSW ASOS................11.0 DAVIS...............11.0 WSW [251 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..............3.11 DEPARTURE....-1.02 ASOS..............3.14 TOTAL PRECIPITATION FOR THE YEAR..........37.88 DEPARTURE....+0.28 ASOS.............39.06 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/-2/0/352/46 36 NNE AERO 33 MPH NNE 9/10 65/53/59/-5/0/603/79 31 ENE 9/11 61/54/58/-6/0.49/000/00 30 NE 9/12 63/60/62/-1/1.74/000/00 30 NNE TSTM 9/13 76/58/67/+4/0.06/393/52 28 NW 9/14 74/55/65/+2/0/699/93 22 WSW 9/15 75/56/66/+4/0/682/91 22 WNW 9/16 61/53/57/-5/T/060/08 31 NNE AERO 29 MPH NNE 9/17 60/49/55/-7/0/022/03 27 N 9/18 71/47/59/-2/T/571/77 35 WSW AERO 30 MPH WSW 9/19 65/45/55/-6/0/716/97 30 NW AERO 28 MPH WNW 9/20 71/45/58/-3/0/721/98 22 SW 9/21 76/50/63/+3/0/703/96 20 S 9/22 74/55/65/+5/0/124/17 27 SSW 9/23 78/61/70/+10/0/145/20 35 SSW 9/24 77/57/67/+8/0/348/48 25 SW 9/25 63/50/57/-2/0/671/93 33 NW 9/26 62/43/53/-6/0/689/96 24 S 9/27 65/49/57/-1/0.32/000/00 32 SE AERO 31 MPH SE 9/28 73/55/64/+6/0.38/619/87 43 W AERO 39 MPH W; DAVIS 45 MPH WSW TSTM 9/29 67/54/61/+3/0.12/533/75 35 S AERO 35 MPH S 9/30 60/42/51/-6/0/049/07 27 WSW 10/1 our morning low temp: 39F; the normal low is now 48F NEW DAILY RECORDS FOR SEPTEMBER 2009 None. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR OCTOBER 1 HIGH 85F IN 1927 LOW 30F IN 1992 PRECIP 1.44 INCHES IN 1984 PEAK GUST 68e MPH SSE IN 1977 RECORDS FOR OCTOBER 2 HIGH 85F IN 1968 LOW 29F IN 1899 PRECIP 1.75 INCHES IN 1984 PEAK GUST 52e MPH S IN 1952, 52 NNW IN 1984 TODAY'S REPORT PREPARED BY: Stephanie Radner