BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SUNDAY, SEPTEMBER 2, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME SPECTACULARLY CLEAR, SUNNY AND DRY TODAY A completely cloudless sky was observed early this morning while at the same time visibility was up to 80 to 90 miles. Visibility as observed from the summit of Mount Washinton in New Hampshire was near their maximum reportable values of 120 to 130 miles. A smoke layer coming from house fires in the city of Lawrence could be seen along our northwest to north horizon between 8 and 9 a.m. drifting to the southwest before it dissipating to our west-northwest by 9 a.m. Looming of the mountains 60 to 70 miles to our northwest was observed at 8 a.m. caused by atmospheric temperature differences. While the Monadnocks appeared very flattened a couple of peaks to the north of them appeared to bulge much higher than usual. A very dry weather pattern appears to be extending the very dry August weather right into the first week of September. Driest Augusts (inches) 1) 0.53 in 1981 2) 0.63 in 2007 3) 0.91 in 1984 4) 1.05 in 1910 5) 1.22 in 1948 August 2007 Summary Avg Max Temp: 81.0 deg F [+2.1] Avg Min Temp: 62.2 deg F [+1.3] Average Temp: 71.6 Deg F [+1.7] Corrected Mean Temp: 70.5 deg F Highest Temp: 93 deg F [25th] Lowest Temp: 51 deg F [19th] Precipitation: 0.63 inch [-3.43] Heating Degree Days: 19 [-3] Cooling Degree Days: 229 [+56] Average Wind Speed: 10.8 mph, S Peak Wind Gust: 46 mph WNW [18th] Mean Vapor Pressure: 17.8 mb Sunshine: 65% (FINAL) Summer 2007 Summary (June-August) Avg Max Temp: 79.3 deg F [+0.8] Avg Min Temp: 60.2 deg F [+0.6] Average Temp: 69.8 Deg F [+0.7] Corrected Mean Temp: 68.8 deg F Highest Temp: 93 deg F [6/27 and 8/25] Lowest Temp: 44 deg F [6/7] Precipitation: 6.83 inches [-4.90] Today's observations: 7 A.M. Weather: Clear, smoke layer aloft along NW-N horizon Temperature: 57F, Dew point: 43F, Wind: N at 08 kts Wind: graudally veering Sea-level pressure: 30.32 inches Hg, rising Visibility: 80 miles 6-hour min temp: 51F 24-hour rainfall: 0.00 BHO SA 1155 CLR 80 266/57/43/3508/032/ K LYR ALF/NR HRZN DSNT NW-N LOOMING OF DSNT MTNS NW WND GRDLY VEERING/ 51020 10057 20051 10 A.M. Weather: Clear, small cumulus forming ESE-SSW Temperature: 69F, Dew point: 42F, Wind: WNW at 04 kts Wind: light and variable Sea-level pressure: 30.31 inches Hg, falling Visibility: 90 miles BHO SA 1455 CLR 90 265/69/42/2904/031/ SML CU FRM ESE-SSW WND L/V/ 8/100 58001 WEATHER SUMMARY FOR SATURDAY, SEPTEMBER 1 TEMPERATURE (DEGREES F) MAX.....79 NORMAL.....75 MIN.....57 NORMAL.....58 MEAN....68 NORMAL.....67 DEPARTURE FROM 30-YEAR NORMAL.........+1 TOTAL DEPARTURE FOR THE MONTH........ +1 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............25 WNW AT 2:32 P.M. * AEROVANE...............23 WNW AT 2:32 P.M. ASOS...................N/A # DAVIS..................25 NW AT 1:02 P.M. FASTEST MILE FOR YESTERDAY................17 WNW AT 2:31 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE.............N/A # MAXIMUM 2-MINUTE DAVIS AVERAGE............20 WNW AT 2:33 P.M. AVERAGE WIND SPEED AND DIRECTION.........10.8 NW ASOS...................N/A # DAVIS.................11.2 NW [320 deg] * last of several occurrences.. # ASOS WINDS SWITCHED OFF BY NWS 6/6, IT IS NOT KNOWN WHEN THAT DATA WILL RESUME PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE.....-0.13 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.00 DEPARTURE.....-0.13 ASOS..............0.00 TOTAL PRECIPITATION FOR THE YEAR..........30.99 DEPARTURE.....-2.61 ASOS.............30.23 PRELIMINARY CLIMATE SUMMARY FOR AUGUST-SEPTEMBER 2007...CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available 8/1 84/67/76/+4/0/851/98 20 NNE 8/2 92/68/80/+8/0/823/95 21 S 8/3 92/70/81/+9/0/760/88 28 SSW 8/4 89/71/80/+8/0/827/96 29 WSW 8/5 80/62/71/-1/0/842/98 23 SSE 8/6 77/61/69/-3/0.05/129/15 36 SSE Aero 34 MPH SSE TSTM 8/7 82/67/75/+4/0.12/410/48 15 SSE 8/8 88/70/79/+8/0.10/349/41 36 S 8/9 75/60/68/-3/0/722/85 32 NW 8/10 63/53/58/-13/0.19/017/02 16 SSW 8/11 83/52/68/-3/0/743/88 21 WNW 8/12 86/64/75/+4/0/665/79 21 SSW 8/13 83/64/74/+3/0.01/260/31 30 NW TSTM 8/14 78/58/68/-2/0/812/97 23 NW 8/15 83/59/71/+1/0/651/78 36 SSW Aero 34 MPH SSW 8/16 87/67/77/+7/0/641/77 33 SSW 8/17 78/62/70/0/0.07/241/29 43 S Aero 39 MPH S TSTM 8/18 71/52/62/-8/0.08/761/92 46 WNW Aero 42 MPH WNW, Davis 46 MPH WNW TSTM 8/19 74/51/63/-7/0/619/75 25 WNW 8/20 70/56/63/-6/0/411/50 21 ENE 8/21 68/56/62/-7/0/271/33 23 E 8/22 70/55/63/-6/0/147/18 23 NE 8/23 75/59/67/-2/T/024/03 22 SSE 8/24 88/66/77/+8/0/552/68 30 SSW 8/25 93/69/81/+13/0/566/70 25 SSE 8/26 84/68/76/+8/T/169/21 22 S 8/27 79/64/72/+4/0/731/91 25 NNE 8/28 83/64/74/+6/0/736/92 21 ESE 8/29 88/64/76/+9/0/782/98 24 SSE 8/30 89/65/77/+10/0/779/98 23 S 8/31 78/65/72/+5/0.01/546/69 28 NNE 9/1 79/57/68/+1/0/.../.. 25 WNW 9/2 morning low temp. 51F; normal low now 57F NEW DAILY RECORDS FOR AUGUST 2007: 8/18 - NEW RECORD PEAK GUST FOR OF 46 MPH WNW; the previous record was 39 MPH SW in 1991 8/25 - RECORD HIGH TEMPERATURE OF 93F; ties previous record set in 1947,1948 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR SEPTEMBER 2 HIGH 99F IN 1953 (SEPTEMBER MAXIMUM RECORD) LOW 44F IN 1909 PRECIP 2.73 INCHES IN 1947 PEAK GUST 55e MPH WNW IN 1944 RECORDS FOR SEPTEMBER 3 HIGH 95F IN 1929 LOW 43F IN 1983 PRECIP 3.82 INCHES IN 1972 (TROPICAL STORM CARRIE) PEAK GUST 58 MPH NNE IN 1972 (TROPICAL STORM CARRIE) TODAY'S REPORT PREPARED By: Robert Skilling