BLUE HILL OBSERVATORY MILTON, MA MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, SEPTEMBER 11, 2010 ALL TIMES ARE IN EASTERN STANDARD TIME SPECTACULAR LATE SUMMER WEATHER TODAY...VERY SUNNY WITH LOW HUMIDITY AND VERY HIGH VISIBILITY... The low temperature this morning was a cool 53 degrees this morning on the summit with a much cooler 44 degrees at the lower elevation of Norwood Airport. This was the lowest temperature since a minimum of 53 was observed on July 1st. There have been only a few small cumulus clouds in the sky today that have not obscured the bright sunshine. With the dew point near 50 degrees, the visibility has been excellent today near 80 miles. Tomorrow is the 50th anniversary of the landfall of Hurricane Donna in New England in 1960. This storm brought the second highest gust ever observed at Blue Hill to 140 mph SSE and 2.79 inches of rain. Today's observations: 7 A.M. Weather: Clear, few stratocumulus along horizon NE-SE, line of stratocumulus castellanus ENE-ESE Temperature: 56F, Dew point: 51F; Wind: NW at 7 kts, Wind: Light Sea-level pressure: 29.97 inches Hg, rising Visibility: 80 miles 6-hour minimum temp: 53F BHO SA 1155 CLR 80 149/56/51/3207/997/ FEW SC ALG HRZN NE-SE LINE SCCAS ENE-ESE WND LGT/ 8/500 52020 10057 20053 10 A.M. Weather: Scattered cumulus, few cumulus fractus Temperature: 67F, Dew point: 51F; Wind: NNE at 7 kts, Wind: Light and variable Sea-level pressure: 30.01 inches Hg, rising Visibility: 80 miles BHO SA 1455 35 SCT 80 164/67/51/0207/001/ FEW CUFRA ALQDS WND LGT AND VRB/ 8/100 51015 1 P.M. Weather: Scattered cumulus Temperature: 67F, Dew point: 50F; Wind: ENE at 12 kts, Wind: Light and variable Sea-level pressure: 30.01 inches Hg, falling slightly Visibility: 80 miles Maximum 6-hour maximum temp: 68F BHO SA 1755 40 SCT 80 162/67/50/0612/001/ WND LGT AND VRB/ 8/100 58002 10068 20056 WEATHER SUMMARY FOR FRIDAY, SEPTEMBER 10 TEMPERATURE (DEGREES F) MAX.....67 NORMAL.....73 MIN.....55 NORMAL.....55 MEAN....61 NORMAL.....64 DEPARTURE FROM 30-YEAR AVERAGE.................-3 TOTAL DEPARTURE FOR THE MONTH.................+57 [+5.5 DEGREES/DAY] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............26 WNW AT 7:23 A.M. AEROVANE..............29 WNW AT 7:23 A.M. * ASOS..................26 NW AT 7:11 A.M. DAVIS.................29 WNW AT 7:11 A.M. THE FASTEST MILE FOR YESTERDAY...........18 WNW AT 7:12 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE............18 NW AT 7:12 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 WNW AT 7:12 A.M. AVERAGE WIND SPEED AND DIRECTION.......10.8 WNW ASOS................10.2 DAVIS...............11.2 WNW [286 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 SEPTEMBER..........0.55 DEPARTURE........-0.78 ASOS..............0.54 TOTAL PRECIPITATION FOR THE YEAR..........46.58 DEPARTURE.......+11.78 ASOS.............46.38 ** ** ASOS missing rainfall due to system failure on 6/24-25 PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 2010 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 93/73/83/+16/0.00/765/97 18 SW 9/2 93/72/83/+17/0.00/740/94 25 SSW 9/3 83/69/76/+10/0.47/039/05 25 NNE 9/4 79/62/71/+5/0.00/672/86 37 WSW AERO 39 MPH WSW 9/5 73/55/64/-1/0.00/778/100 28 SW AERO 32 MPH SW 9/6 76/54/65/0/T/768/99 22 SSW 9/7 84/62/73/+8/0.00/440/57 30 SSW AERO 32 MPH S 9/8 80/59/70/+5/0.08/.../.. 35 W AERO 40 MPH W 9/9 72/55/64/0/T/.../.. 28 W 9/10 67/55/61/-3/0.00/.../.. 26 WNW 9/11 morning low temp: 53F; the normal low is now 55F NEW DAILY RECORDS FOR SEPTEMBER 2010 9/1 - High maximum temperature of 93F equals the previous record of 93F set in 1969 9/1 - High minimum temperature of 73F surpasses the previous record of 71F in 1898, 1959 9/2 - High minimum temperature of 72F surpasses the previous record of 71F in 1959 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): 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) RECORDS FOR SEPTEMBER 12 HIGH 92F IN 1961 LOW 42F IN 1958,1967,1985 PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA) PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA) TODAY'S REPORT PREPARED BY: Mike Iacono