BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY SEPTEMBER 2, 2008 ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED AUGUST WAS COOL AND SLIGHTLY WETTER THAN AVERAGE THE MONTH FEATURED A VERY CLOUDY FIRST HALF AND A VERY SUNNY SECOND HALF...DAILY WIND SPEEDS AVERAGED VERY LOW THROUGHOUT THE MONTH The mean temperature for August of 68.4 degrees was 1.5 degrees below the 30-year average. However, the mean of 67.3 (corrected for 24 hours) comes in as the lowest August corrected mean temperature since 1986. There were no 90-degree days and the highest for the month was only 85 degrees on the 18th. There were 13 days with measurable rainfall but the month had all but two of those days during the first half. Despite a very cloudy first half, the second half of August had 85% of the possible sunshine when a total of ten days had over 90% of the possible bright sunshine. The final day of the month had 100% of the possible sunshine. The month wound up with 63% of the possible sunshine which is about 5 points more sunshine than average. Wind speeds were unusually low throughout the month with the corrected average of 9.5 MPH equaling the lowest on record with August 1996. THE MONTHLY STATS: Mean temp. 68.4 [-1.5] deg F Heating units: 13 [-9] Cooling units: 123 [-50] Precip: 4.53 ins. [+0.47] Corrected sunshine: 16148 mins. [269.1 hrs] Percent of sunshine: 63% Uncorrected sunshine: not yet available Uncorr. av. wind speed: 8.8 MPH Corrected av. wind speed: 9.5 MPH Prevailing wind direction: WNW 13% Av. vapor pressure: 17.4 mbs. Today's observations: 8 A.M. EDT Weather: Scattered dense cirrus and cirrocumulus, thin broken cirrus. few altocumulus distant west Temperature: 66F, Dew point: 54F, Wind: NNW at 9 kts Sea-level pressure: 30.08 inches Hg, rising Visibility: 60 miles, 70 NW 6-hourly minimum temperature: 60F 24-hourly rainfall: 0.00 BHO SA 1155 220 SCT 250 –BKN 60 185/66/54/3409/008/ FEW AC DSNT W-WNW DENS CI/CC ALQDS VSBY NW 70/ 8/042 53012 10066 20060 11 A.M. EDT Weather: Scattered dense cirrus and thin cirrus, few cirrocumulus south, cumulus forming south thru west thru north Temperature: 71F, Dew point: 57F, Wind: NNE at 9 kts, Wind: direction variability N to ENE Sea-level pressure: 30.08 inches of Hg. and steady Visibility: 60 miles, NW 70 miles BHO SA 1455 220 SCT 250 SCT 60 185/71/57/0309/008/ CU FRMG S-W-N PTCH ACSL N DENS CI NNE-E-S FEW CC S VSBY NW 70 WND 35V06/ 50000 2 P.M. EDT Weather: Scattered cumulus/stratocumulus, dense cirrus, thin broken cirrus Temperature: 73F, Dew point: 58F, Wind: NE at 12 kts Sea-level pressure: 30.04 ins. Hg. and falling Visibility: 60 miles, NW 70 miles 6-hourly max. temp. 74F 6-hourly rainfall: None BHO SA 1755 40 SCT 60 SCT 220 SCT 250 –BKN 60 173/73/58/0412/004/ SC DSNT E-ESE FEW MDT CU FEW DENS CI VSBY NW 70 WND 36V07/ 8/802 56012 10074 20066 WEATHER SUMMARY FOR MONDAY, SEPTEMBER 1, LABOR DAY TEMPERATURE (DEGREES F) MAX.....81 NORMAL.....75 MIN.....57 NORMAL.....58 MEAN....69 NORMAL.....67 DEPARTURE FROM 30-YEAR NORMAL.............+2 TOTAL DEPARTURE FOR THE MONTH.............+2 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............29 NW AT 9:39 A.M. AEROVANE.............28 NW AT 9:39 A.M. ASOS.................29 NNW AT 2:12 P.M. DAVIS................29 NNW AT 2:16 P.M. FASTEST MILE FOR YESTERDAY............. 19 NW AT 3:09 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........20 NNW AT 2:16 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........21 NW AT 2:16 P.M. AVERAGE............13.3 NW ASOS...............12.5 DAVIS..............13.7 NW [310 deg] 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 AUGUST.............4.53 DEPARTURE.......+0.47 ASOS..............4.57 TOTAL PRECIPITATION FOR THE YEAR..........35.46 DEPARTURE.......+1.86 ASOS.............38.00 # # Includes erroneous ASOS precipitation data on 2/13/08. PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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 8/1 85/66/76/+4/0.00/719/83 16 WSW 8/2 80/65/73/+1/0.80/346/40 21 NW TSTM 8/3 81/61/71/-1/0.56/422/49 52 NW Aero 55 MPH NW TSTM 8/4 79/60/70/-2/0.01/731/85 25 WNW 8/5 72/63/68/-4/T/377/44 21 NE 8/6 64/60/62/-10/0.55/000/00 31 ESE 8/7 72/61/67/-4/0.41/009/01 21 SW TSTM 8/8 77/59/68/-3/0.47/442/52 23 ENE TSTM 8/9 78/59/69/-2/0.00/534/63 16 SSE 8/10 80/61/71/0/0.08/474/56 24 ESE TSTM 8/11 67/61/64/-7/0.06/025/03 25 E 8/12 72/58/65/-6/0.18/134/16 21 NNW TSTM 8/13 79/59/69/-2/0.00/778/93 18 WSW 8/14 78/63/71/+1/T/334/40 21 NNW 8/15 79/62/71/+1/1.32/125/15 18 SSW TSTM 8/16 79/61/70/0/0.01/647/78 23 WSW 8/17 80/59/70/0/0.00/787/95 28 WSW 8/18 85/64/75/+5/0.00/759/92 28 SSW 8/19 78/54/66/-4/0.05/576/70 29 WNW TSTM 8/20 72/50/61/-8/0.00/812/99 28 WNW 8/21 78/55/67/-2/0.00/801/98 16 WNW 8/22 82/60/71/+2/0.00/799/98 20 S 8/23 80/60/70/+1/0.00/771/95 21 S 8/24 80/60/70/+1/0.00/697/86 18 S 8/25 82/58/70/+2/0.00/258/32 28 NNW 8/26 72/52/62/-6/0.00/788/98 25 NNW 8/27 74/52/63/-5/0.00/778/97 21 NNE 8/28 74/59/67/-1/0.00/743/93 22 NE 8/29 79/57/68/+1/0.00/549/69 18 S 8/30 76/63/70/+3/0.03/143/18 23 SSW 8/31 78/62/70/+3/0.00/790/100 35 WNW 9/1 81/57/69/+2/0.00/787/100 29 NW 9/2 our morning low temp: 60F; normal low is now 57F NEW DAILY RECORDS FOR AUGUST 8/3 - PEAK GUST OF 52 MPH FROM THE NW IS NEW RECORD FOR THE DATE; PREVIOUS RECORD 41 MPH NE IN 1964 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