BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, SEPTEMBER 10, 2008 ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED THUNDERSTORM BROUGHT WIND GUST TO 46 MPH SW (Aerovane) YESTERDAY SEPTEMBER CONTINUES MUCH WARMER AND SUNNIER THAN AVERAGE A brief peak wind gust to 46 MPH SW was recorded on our Aerovane wind system early yesterday afternoon during a thunderstorm. A sudden downpour left 0.19 inch in just five minutes ending at 1:10 P.M. EDT. Light rainfall during the rest of the afternoon and evening brought a total of 0.32 inch for the day. September continues to be warmer than normal by almost five degrees with 71% of the possible sunshine running well above the monthly normal of 56%. Today's observations: 8 A.M. EDT Weather: Clear, few stratocumulus distant NNW-N along the horizon, cirrus, dense cirrus along horizon distant to the SE-S Temperature: 55F, Dew point: 50F, Wind: NW at 10 kts Sea-level pressure: 30.19 inches Hg, rising Visibility: 80 miles 6-hourly minimum temperature: 52F 24-hourly rainfall: 0.32 inch BHO SA 1155 CLR 80 222/55/50/3110/019/ FEW SC DSNT NNW-N ALG HRZN CI/DENS CI LYR ALG HRZN DSNT ESE-SSW/ 8/502 53025 MANUAL 70032 ASOS 70031 10055 20052 11 A.M. EDT Weather: Clear Temperature: 63F, Dew point: 47F, Wind: NW at 11 kts Wind: direction variable W to N Sea-level pressure: 30.24 inches Hg, rising Visibility: 80 miles BHO SA 1455 CLR 80 240/63/47/3111/024/ CU FRMG ALQDS CI/DNS CI LYR ALG HRZN DSNT SE-SSW WND GUST 20 KTS PST HR WND 28V35/ 8/102 53018 2 P.M. EDT Weather: Scatterd stratocumulus, cumulus Temperature: 67F, Dew point: 48F, Wind: NW at 10 kts, Wind: direction variable W-NNW Sea-level pressure: 30.26 inches Hg, steady Visibility: 75 miles 6-hour max. temp: 67F BHO SA 1755 47 SCT 75 246/67/48/3110/026/ WND 27V34/ 8/400 51006 10067 20055 WEATHER SUMMARY FOR TUESDAY, SEPTEMBER 9 TEMPERATURE (DEGREES F) MAX.....73 NORMAL.....73 MIN.....60 NORMAL.....55 MEAN....67 NORMAL.....64 DEPARTURE FROM 30-YEAR NORMAL............+ 3 TOTAL DEPARTURE FOR THE MONTH............+44 (+4.7 PER DAY) PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............43 SW AT 12:06 P.M. * AEROVANE.............46 SW AT 12:06 P.M. * ASOS.................43 SW AT 12:06 P.M. * DAVIS................40 W AT 12:06 P.M. * FASTEST MILE FOR YESTERDAY............. 31 WSW AT 12:06 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........29 WSW AT 12:07 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........29 WSW AT 12:06 P.M. AVERAGE............14.5 S ASOS...............14.3 DAVIS..............13.3 S [180 deg] * thunderstorm gust PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.32 DEPARTURE.......+0.18 ASOS..............0.31 TOTAL PRECIPITATION FOR SEPT..............2.51 DEPARTURE.......+1.32 ASOS..............2.52 TOTAL PRECIPITATION FOR THE YEAR..........37.97 DEPARTURE.......+3.31 ASOS.............40.52 # # 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 Aero 20 MPH SSE 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 the morning low temp: 52F; our normal low is now 55F * Tropical Storm Hanna # Thunderstorm gust 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 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: Robert Skilling