BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, SEPTEMBER 18, 2008 ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED Today's observations: 8 A.M. EDT Weather: Clear, few cirrus E-S Temperature: 58F, Dew point: 52F, Wind: NW at 13 kts Wind: direction variability W-N Sea-level pressure: 30.11 inches Hg, rising Visibility: 45 miles, NW 55 miles 6-hourly minimum temperature: 55F 24-hourly rainfall: 0.00 inch BHO SA 1155 CLR 45 198/58/52/3213/011/ FEW CI E-S VSBY NW 55 WND 27V01/ 8/001 53023 10058 20055 11 A.M. EDT Weather: Broken stratocumulus, broken cirrus Temperature: 63F, Dew point: 50F, Wind: NNE at 13G21 kts Wind: direction variability NNW-E Sea-level pressure: 30.19 inches Hg, rising Visibility: 80 miles BHO SA 1455 E30 BKN 250 BKN 80 224/63/50/0313G21/019/ WND 34V90/ 8/501 52026 2 P.M. EDT Weather: Scattered stratocumulus, scattered cirrus Temperature: 60F, Dew point: 48F, Wind: NE at 14G21 kts, Wind: direction variability N-E Sea-level pressure: 30.22 inches Hg, rising Visibility: 75 miles 6-hour max. temp: 65F BHO SA 1755 40 SCT 250 SCT 75 234/60/48/0514G21/022/ WND 35V09/ 8/501 51010 10065 20058 WEATHER SUMMARY FOR WEDNESDAY, SEPTEMBER 17 TEMPERATURE (DEGREES F) MAX.....72 NORMAL.....71 MIN.....53 NORMAL.....53 MEAN....63 NORMAL.....62 DEPARTURE FROM 30-YEAR NORMAL.............+1 TOTAL DEPARTURE FOR THE MONTH............+47 (+2.6 DEGREES/DAY) PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............20 S AT 7:37 P.M. AEROVANE.............17 S AT 8:09 P.M. ASOS.................18 SSW AT 8:08 P.M. DAVIS................19 S AT 8:30 P.M. FASTEST MILE FOR YESTERDAY..............14 S AT 7:46 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........14 WSW AT 11:42 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........unknown AVERAGE............ 7.6 S ASOS................7.7 DAVIS...............7.0 SSW [221 deg] 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 SEPT..............3.13 DEPARTURE.......+0.82 ASOS..............3.15 TOTAL PRECIPITATION FOR THE YEAR..........38.59 DEPARTURE.......+2.81 ASOS.............41.15 # # Includes erroneous ASOS precipitation data on 2/13/08. PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 2008 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 9/1 81/57/69/+2/0.00/787/100 29 NW 9/2 74/60/67/+1/0.00/604/77 27 N 9/3 75/57/66/0/0.00/766/98 22 N 9/4 85/62/74/+8/0.00/748/96 23 SSW 9/5 86/67/77/+12/0.00/575/74 32 SSE 9/6 82/68/75/+10/1.88/039/05 44 SE Aero 39 MPH SE * 9/7 78/61/70/+5/0.31/655/85 43 NW Aero 43 MPH NW * 9/8 78/58/68/+3/0.00/753/98 23 WSW 9/9 73/60/67/+3/0.32/054/07 43 SW Aero 46 MPH SW TSTM # 9/10 68/52/60/-4/0.00/748/98 25 WNW 9/11 69/48/59/-5/0.00/616/81 23 S 9/12 66/54/60/-3/0.22/008/01 33 S 9/13 74/62/68/+5/T/113/15 21 S 9/14 70/64/67/+4/0.40/000/00 35 S 9/15 79/60/70/+8/0.00/697/93 45 WSW Aero 45 MPH WSW ** 9/16 64/54/59/-3/0.00/045/06 21 NNW 9/17 72/53/63/+1/0.00/.../.. 20 S Aero 17 MPH S 9/18 morning low temp. 55F; our normal low is now 53F * Tropical Storm Hanna # Thunderstorm gust ** Ike remnants NEW DAILY RECORDS FOR SEPTEMBER None to date.. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR SEPTEMBER 18 HIGH 88F IN 1906 LOW 36F IN 1919 PRECIP 4.25 INCHES IN 1996 PEAK GUST 77e MPH WNW IN 1948 RECORDS FOR SEPTEMBER 19 HIGH 87F IN 1906,1983 LOW 37F IN 1929 PRECIP 3.69 INCHES IN 1936 PEAK GUST 48 MPH NE IN 1972 TODAY'S REPORT PREPARED By: Stephanie Radner