BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, MAY 3, 2008 ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED COOL AND WET CONDITIONS TODAY...APRIL WAS 8TH WARMEST ON RECORD...APRIL HAD LOWEST WIND SPEED ON RECORD... Rain showers early this morning have turned into a more general light rainfall by late morning. A total of 0.03 inch has been measured since 8 AM EDT. The temperature has remained in the low 40s all day with a range in temperature of only 2 degrees from 43 to 41 so far today. April mean temperature of 48.5 (corrected to 24-hours) was the 8th warmest on record. The mean wind speed for April was only 12.0 mph, which is the lowest on record for that month. April 2008 Summary Tmax: 58.9 [+3.4] Tmin: 39.1 [+2.0] Tmean: 49.0 [+2.7] Precip: 3.16 [-1.16] Snow: 0.0 [-3.1] HDD: 474 CDD: 2 Mean Wind Speed: 12.0 mph, NE Peak Wind Gust: 54 mph S April Lowest Mean Wind Speed (mph) 1) 12.0 in 2008 2) 12.4 in 2001 3) 12.7 in 1998 4) 12.8 in 1986 5) 13.1 in 2005 Today's observations: 8 A.M. EDT Weather: Overcast, light rain shower ended past hour Temperature: 42F, Dew point: 38F, Wind: ENE at 13G21 kts Sea-level pressure: 30.18 inches Hg, rising Visibility: 30 miles 6-hour min temp: 42F 24-hour precip: 0.10 in. BHO SA 1155 E30 OVC 30 221/42/38/0713G21/018/ FEW LWR STRA HAZY RE20/ 8/5// 51017 600// 70010 10043 20042 11 A.M. EDT Weather: Overcast, light rain shower Temperature: 43F, Dew point: 37F, Wind: ENE at 8 kts Sea-level pressure: 30.19 inches Hg, rising Visibility: 35 miles 3-hour precip: trace BHO SA 1455 E30 OVC 35RW- 225/43/37/0708/019/ HAZY RB45 WND LGT/ 8/5// 53004 6000/ 2 P.M. EDT Weather: Overcast, light rain Temperature: 41F, Dew point: 40F, Wind: ENE at 14 kts Sea-level pressure: 30.16 inches Hg, falling Visibility: 10 miles, thin fog 6-hour max. temp: 43F 6-hour precip: 0.03 inch BHO SA 1755 E20 OVC 10R- 215/41/40/0614/016/ THN F/ 8/6// 58010 6003/ 10043 20041 WEATHER SUMMARY FOR FRIDAY, MAY 2 TEMPERATURE (DEGREES F) MAX.....48 NORMAL.....62 MIN.....42 NORMAL.....43 MEAN....45 NORMAL.....52 DEPARTURE FROM 30-YEAR NORMAL............-7 TOTAL DEPARTURE FOR THE MONTH...........-11 [-5.7 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............20 DEPARTURE........+7 TOTAL HEATING UNITS FOR THE MONTH............37 DEPARTURE.......+11 TOTAL HEATING UNITS FOR THE SEASON.........5648 DEPARTURE......-404 TOTAL HEATING UNITS LAST SEASON TO DATE....5635 DIFFERENCE......+13 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............21 ENE AT 7:00 P.M. * AEROVANE.............19 ENE AT 7:00 P.M. ASOS.................18 E AT 1:57 P.M. DAVIS................19 ENE AT 1:56 P.M. FASTEST MILE FOR YESTERDAY..............14 ENE AT 7:06 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........14 E AT 7:02 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........15 E AT 7:02 P.M. AVERAGE.............7.8 ENE ASOS................7.0 DAVIS...............6.6 E [86 deg] * last of several occurrences. PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.10 DEPARTURE......-0.03 ASOS..............0.09 TOTAL PRECIPITATION FOR THE MONTH..........0.13 DEPARTURE......-0.13 ASOS..............0.12 TOTAL PRECIPITATION FOR THE YEAR..........20.89 DEPARTURE......+2.68 ASOS.............23.35 # # Includes erroneous ASOS precipitation data on 2/13/08. SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE.......0.0 TOTAL SNOWFALL FOR THE MONTH...............0.0 DEPARTURE......-0.1 TOTAL SNOWFALL FOR THE SEASON.............66.5 DEPARTURE......+6.4 ** ** corrected error of 0.1 in snowfall departure for the season; this error was introduced in late March or early April PRELIMINARY CLIMATE SUMMARY FOR APRIL 2008 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available, records not finalized 4/1 59/50/55/+14/0.20/0/000/00 54 S Aero 58 MPH SSW 4/2 47/31/39/-3/0/0/745/97 52 W Aero 51 MPH W 4/3 52/27/40/-2/0/0/648/84 37 SSW 4/4 43/34/39/-3/0.71/0/000/00 35 E 4/5 51/37/44/+1/0.06/0/093/12 21 W 4/6 40/36/38/-5/0.09/0/000/00 36 NE 4/7 39/34/37/-6/0/0/172/22 35 NE Aero 36 MPH NE 4/8 47/30/39/-5/0/0/627/80 22 NE 4/9 59/33/47/+3/0/0/150/19 29 S 4/10 71/44/58/+14/T/0/624/79 34 W 4/11 54/40/47/+2/0.03/096/13 24 SE 4/12 70/43/57/+12/0.43/0/342/43 40 WNW Aero 42 WNW 4/13 47/34/41/-4/T/0/104/13 30 NW 4/14 53/30/42/-4/0/0/625/78 29 NW 4/15 57/33/45/-1/0/0/803/100 23 SSE 4/16 64/39/52/+6/0/0/806/100 24 SSE 4/17 64/14/53/+6/0/0/810/100 23 NE 4/18 70/42/56/+9/0/0/723/89 23 NW 4/19 70/46/58/+11/0/0/799/98 22 NE 4/20 67/42/55/+7/0/0/760/93 25 ESE 4/21 61/41/51/+3/0/0/615/75 17 E 4/22 74/45/60/+11/0/0/789/96 23 S 4/23 83/50/67/+18/0/0/784/95 25 SW 4/24 72/53/63/+14/0/0/802/97 38 WNW Aero 39 WNW 4/25 71/46/59/+9/0/0/557/67 25 E 4/26 55/42/49/-1/T/0/716/86 27 ENE 4/27 49/40/45/-5/0.02/0/000/00 16 ESE 4/28 57/39/48/-3/0.67/0/008/01 39 SE Aero 39 SE 4/29 60/39/50/-1/0.95/0/008/01 44 WNW Aero 44 WNW 4/30 54/35/45/-7/0/0/700/83 29 WSW PRELIMINARY CLIMATE SUMMARY FOR MAY 2008 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available, records not finalized 5/1 60/35/48/-4/0/0/.../.. 30 W Aero 28 W 5/2 48/42/45/-7/.../0/.../.. 21 ENE 5/3 morning low temp. 42F; our normal low is now 43F NEW DAILY RECORDS FOR MAY 2008 None to date. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 3 HIGH 92F IN 2001 LOW 31F IN 1888 PRECIP 2.25 INS IN 1900 SNOWFALL TRACE IN 1908, 1985 PEAK GUST 71 MPH W IN 2002 RECORDS FOR MAY 4 HIGH 90F IN 2001 LOW 27F IN 1911 (RECORD FOR MAY) PRECIP 1.92 INCHES IN 1893 SNOWFALL 0.1 INCHES IN 1920 PEAK GUST 60 MPH NW IN 1966 TODAY'S REPORT PREPARED By: Mike Iacono