BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, AUGUST 9, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME A high pressure system moved in this morning bringing cool, dry conditions and consequently a spectacular array of cloud types and visibility of 80 miles from the observatory. The dew point temperature dipped down to 30 degrees around 3:25 P.M. EDT and the relative humidity was measured at 20 percent! The maximum air temperature was 75 degrees as of 3:30 P.M. EDT and winds are light and variable. Today's observations: 7 A.M. Weather: Thin broken cirrus Temperature: 65F, Dew point: 55F, Wind: NNW at 06 kts Sea-level pressure: 29.94 inches Hg, rising Visibility: 80 miles 6-hour min temp: 60 deg. F 24-hour precip: 0.10 inch BHO SA 1155 250 –BKN 80 138/65/55/3406/994/ FEW SC DSNT E-S/ 8/501 51029 ASOS 70010 MANUAL 70010 10070 20060 10 A.M. Weather: Scattered cumulus, scattered cirrocumulus, thin broken cirrus Temperature: 70F, Dew point: 49F, Wind: NNE at 07 kts Wind: Variability SSE-SSW Sea-level pressure: 29.98 inches Hg, rising Visibility: 80 miles BHO SA 1455 40 SCT 200 SCT 250 –BKN 80 151/70/49/0207/998/ WND 32V09/ 8/101 51013 1 P.M. Weather: Scattered cirrocumulus, thin broken cirrostratus Temperature: 74F, Dew point: 39F, Wind: NNE at 04 kts Sea-level pressure: 29.98 ins. and rising Visibility: 80 miles 6-hour max. temp: 74 deg. F BHO SA 1755 200 SCT 220 –BKN 80 153/74/39/0304/998/ FEW CU DSNT SSW-NW FEW CCSL FEW CCCAS PARTIAL HALO WND LGT AND VRB/ 8/109 53002 10074 20065 WEATHER SUMMARY FOR WEDNESDAY, AUGUST 8 TEMPERATURE (DEGREES F) MAX.....88 NORMAL.....80 MIN.....70 NORMAL.....62 MEAN....79 NORMAL.....71 DEPARTURE FROM 30-YEAR NORMAL.........+8 TOTAL DEPARTURE FOR THE MONTH........+37 (+4.4 DEGREES/DAY) PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............36 S AT 10:35 A.M. * AEROVANE...............36 S AT 10:35 A.M. ASOS...................N/A # DAVIS..................39 S AT 9:18 A.M. FASTEST MILE FOR YESTERDAY................28 S AT 10:07 A.M. * MAXIMUM 2-MINUTE ASOS AVERAGE.............N/A # MAXIMUM 2-MINUTE DAVIS AVERAGE............29 S AT 10:21 A.M. AVERAGE WIND SPEED AND DIRECTION..........15.0 SSE ASOS...................N/A # DAVIS..................14.8 SSW [209 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....0.10 DEPARTURE.....-0.03 ASOS..............0.10 TOTAL PRECIPITATION FOR THE MONTH..........0.27 DEPARTURE.....-0.74 ASOS..............0.25 TOTAL PRECIPITATION FOR THE YEAR..........30.63 DEPARTURE.....+0.21 ASOS FOR YEAR..........29.92 PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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/+4/0/782/94 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/.../.. 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/.../.. 15 SSE 8/8 88/70/79/+8/0.10/.../.. 36 S 8/9 morning low temp. 60 deg; normal low now 62 deg. NEW DAILY RECORDS FOR AUGUST 2007: None to date DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR AUGUST 9 HIGH 100F IN 1949 LOW 49F IN 1899 PRE 2.65 INS IN 1976 PEAK GUST 90 MPH SW IN 1968 RECORDS FOR AUGUST 10 HIGH 101F IN 1949 [STATION RECORD MAXIMUM - Tied with 8/2/1975] LOW 49F IN 1964 PRE 2.27 INS IN 1952 PEAK GUST 88e MPH S IN 1976 TODAY'S REPORT PREPARED By: Stephanie Radner and Eli Melaas