BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, AUGUST 1, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME MORE RAINFALL WITH THUNDER ON FRIDAY... JULY WAS SIXTH WETTEST ON RECORD... SUNNY, WARM AND HUMID WEATHER TO START AUGUST... Rainfall on Friday afternoon fell mostly during two heavy showers just after noon and from 5:15-5:30 PM EDT. The peak gust for the day of 39 mph WNW at 5:16 PM EDT occurred right after a wind shift that preceeded the rain shower at that time. This was the ninth day with thunder during July. The final July rainfall of 7.62 inches makes this the 6th wettest July on record. WETTEST JULYS, 1886-2009 (inches) 1) 11.67 in 1938 2) 10.66 in 1988 3) 10.43 in 1921 4) 9.52 in 1915 5) 8.47 in 1889 6) 7.62 in 2009 7) 7.55 in 1916 8) 7.41 in 1898 July 2009 Summary Temp Max: 76.4 deg F [-4.8] Temp Min: 60.6 deg F [-1.4] Temp Mean: 68.5 deg F [-3.1] Temp Mean 24-hr corrected: 67.6 deg F Precipitation: 7.62 inches [+3.88] HDD: 20 [+11] CDD: 137 [-78] Mean Wind Speed corrected: 11.1 mph, S Peak Wind Gust: 46 mph NE [24th] Sunshine: 51% Thunderstorm Days: 9 Mean Station Pressure: 29.25 inches Mean Sea-level Pressure: 29.94 inches Vapor Pressure: 18.0 mb Today's observations: 7 A.M. Weather: Scattered cirrus, hazy Temperature: 67F, Dew point: 64F, Wind: WNW at 7 kts Sea-level pressure: 30.06 inches Hg, rising Visibility: 25 miles, hazy 24-hour precipitation: 0.50 inch 6-hour minimum temp: 63F BHO SA 1155 250 SCT 25 180/67/64/2907/006/ HAZY WND LGT/ 8/001 53027 70050 10066 20063 10 A.M. Weather: Clear, cirrus distant E-SE, few small cumulus all quadrants, hazy Temperature: 75F, Dew point: 65F, Wind: SSW at 2 kts (estim.) Sea-level pressure: 30.09 inches Hg, rising Visibility: 30 miles, hazy BHO SA 1455 CLR 30 189/75/65/2002E/009/ CI DSNT E-SE FEW SML CU ALQDS HAZY WND LGT AND VRB/ 8/101 51009 1 P.M. Weather: Scattered cumulus, hazy Temperature: 80F, Dew point: 61F, Wind: WSW at 6 kts, Sea-level pressure: 30.09 inches Hg, falling Visibility: 35 miles 6-hourly max. temp: 81F BHO SA 1755 40 SCT 35 189/80/61/2506/009/ HAZY WND LGT/ 8/100 50000 10081 20067 WEATHER SUMMARY FOR FRIDAY, JULY 31 TEMPERATURE (DEGREES F) MAX.....81 NORMAL.....81 MIN.....66 NORMAL.....63 MEAN....74 NORMAL.....72 DEPARTURE FROM 30-YEAR AVERAGE..........+2 TOTAL DEPARTURE FOR THE MONTH..........-88 [-3.0 DEGREES/DAY] HEATING DEGREE DATA WILL RESUME IN SEPTEMBER PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............39 WNW AT 4:16 P.M. * AEROVANE..............39 WNW AT 4:15 P.M. ASOS..................39 NW AT 4:16 P.M. DAVIS.................39 WNW AT 4:15 P.M. FASTEST MILE FOR YESTERDAY...............29 WNW AT 4:16 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............29 NW AT 4:17 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........30 WNW AT 4:16 P.M. AVERAGE WIND SPEED AND DIRECTION.......11.6 SSE ASOS................10.6 DAVIS...............10.4 SSW [200 DEG] * last of several occurrences.... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.50 DEPARTURE....+0.38 ASOS..............0.48 TOTAL PRECIPITATION FOR THE MONTH..........7.62 DEPARTURE....+3.88 ASOS..............7.73 TOTAL PRECIPITATION FOR THE YEAR..........31.26 DEPARTURE....+1.85 ASOS.............32.38 PRELIMINARY CLIMATE SUMMARY FOR JULY 2009 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 7/1 62/57/60/-10/0.51/000/00 25 NNE TSTM 7/2 66/56/61/-9/1.00/000/00 29 SSW TSTM 7/3 75/58/67/-3/T/283/31 23 WSW 7/4 77/59/68/-2/0/838/92 43 W 7/5 78/54/66/-5/0/856/94 33 W 7/6 79/60/70/-1/0/883/97 20 SSE 7/7 66/58/62/-9/0.73/027/03 28 SE TSTM 7/8 67/56/62/-9/0.23/091/10 27 NNE TSTM 7/9 66/55/61/-10/0/689/76 23 NE 7/10 76/54/65/-6/0/896/99 21 SW 7/11 77/56/67/-5/0.29/686/76 36 S 7/12 78/60/69/-3/0.33/650/72 30 SSW TSTM 7/13 76/55/66/-6/0/802/89 32 SW 7/14 75/56/66/-6/0/567/63 25 WNW 7/15 79/55/67/-5/0/826/92 30 WSW 7/16 77/62/70/-2/T/161/18 30 S 7/17 86/65/76/+4/0.01/582/65 24 ESE 7/18 84/66/75/+3/0.35/447/50 25 SSW TSTM 7/19 80/62/71/-1/0/865/97 27 WSW 7/20 80/64/72/0/0/481/54 16 E 7/21 66/61/64/-8/0.62/000/00 29 NNE 7/22 77/61/69/-3/T/160/18 15 W 7/23 72/60/66/-6/0.68/195/22 35 NE 7/24 69/60/65/-8/2.07/088/10 46 NE AERO 45 NE 7/25 83/61/72/-1/0/766/87 30 SSE 7/26 82/68/75/+3/0.05/422/48 32 S 7/27 83/69/76/+4/0/588/67 30 S TSTM 7/28 86/67/77/+5/0/709/81 24 S 7/29 82/69/76/+4/0/070/08 29 S 7/30 84/69/77/+5/0.25/392/45 25 S TSTM 7/31 81/66/74/+2/0.50/.../.. 39 WNW AERO 39 WNW TSTM 7/31 our morning low temp: 67F; the normal low is now 63F NEW DAILY RECORDS FOR JULY 2009 TO DATE... 7/24: New record peak gust 46 MPH NE at 3:32 A.M. surpasses previous record of 43 MPH S IN 2008 PRELIMINARY CLIMATE SUMMARY FOR AUGUST 2009 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 8/1 morning low temp: 63F; the normal low is now 63F DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR AUGUST 1 HIGH 97F IN 1917 LOW 49F IN 1891 PRECIP 3.61 INCHES IN 1927 PEAK GUST 41 MPH NNW IN 1985 RECORDS FOR AUGUST 2 HIGH 101F IN 1975 [STATION RECORD MAXIMUM - Tied with 8/10/1949] LOW 50F IN 1929, 1947 PRECIP 1.59 INCHES IN 1946 PEAK GUST 50 MPH SW IN 2006 TODAY'S REPORT PREPARED BY: Mike Iacono