BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, MAY 1, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME Today's observations: 7 A.M. Weather: Broken stratus, overcast altocumulus, few lower stratus fractus drifting in vicinity of station, bright spots in overcast, sun occasionally visible Temperature: 57F, Dew point: 54F, Wind: SSW at 19G29 kts Wind: Peak gust past hour 31 kts S at 6:36 A.M. Wind: Direction variability SSE to SW Sea-level pressure: 29.94 inches Hg, falling Visibility: 10 miles, thin fog 6-hour minimum temp: 54F 6-hour precipitation: Trace 24-hour precipitation: Trace BHO SA 1155 E15 BKN 90 OVC 10 139/57/54/2019G29/994/ FEW LWR STFRA DRFTG VCTY STN BRGHT SPTS IOVC SUN OCNL VSBL THN FG RB10E35 PCPN VRY LGT PK WND 1931/36 WND 16V23/ 8/63/ 56013 MANUAL 6000/ 10057 20054 10 A.M. Weather: Overcast stratus Temperature: 60F, Dew point: 56F, Wind: S at 20G28 kts, Wind: Peak gust past hour 29 kts S at 9:41 A.M. Sea-level pressure: 29.89 inches Hg, falling Visibility: 10 miles, thin fog/haze BHO SA 1455 E15 OVC 10 122/60/56/1920G28/989/ THN FG/HAZY PK WND 1929/41/ 8/6// 56017 1 P.M. Weather: Overcast stratus Temperature: 63F, Dew point: 57F, Wind: SW at 18G29 kts Wind: Peak gust past hour 29 kts SSW at 12:44 P.M. Sea-level pressure: 29.85 inches Hg, falling Visibility: 8 miles, hazy 6-hour maximum temp: 64F 6-hour precipitation: Trace BHO SA 1755 E15 OVC 8 108/63/57/2218G29/985/ HAZY RB40E50 PK WND 2029/44/ 8/6// 56014 MANUAL 6000/ 10064 20057 WEATHER SUMMARY FOR THURSDAY, APRIL 30 TEMPERATURE (DEGREES F) MAX.....67 NORMAL.....61 MIN.....41 NORMAL.....42 MEAN....54 NORMAL.....52 DEPARTURE FROM 30-YEAR NORMAL...........+2 TOTAL DEPARTURE FOR THE MONTH.........+101 [+3.2 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............11 DEPARTURE.......-3 TOTAL HEATING UNITS FOR THE MONTH...........478 DEPARTURE......-84 TOTAL HEATING UNITS FOR THE SEASON.........5896 DEPARTURE.....-130 TOTAL HEATING UNITS LAST SEASON TO DATE....5611 DIFFERENCE....+285 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............37 S AT 3:27 P.M. AEROVANE.............36 S AT 3:48 P.M. ASOS.................38 S AT 3:27 P.M. DAVIS................38 S AT 3:48 P.M. FASTEST MILE FOR YESTERDAY..............29 S AT 3:49 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........28 SSW AT 3:55 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........28 S AT 3:55 P.M. AVERAGE WIND SPEED AND DIRECTION......15.2 S ASOS...............15.0 DAVIS..............13.7 SSW [192 DEG] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...trace DEPARTURE....-0.13 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........4.53 DEPARTURE....+0.21 ASOS..............4.55 TOTAL PRECIPITATION FOR THE YEAR..........14.61 DEPARTURE....-3.34 ASOS.............15.68 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.....-0.1 TOTAL SNOWFALL FOR THE MONTH................0.2 DEPARTURE.....-2.8 TOTAL SNOWFALL FOR THE SEASON..............78.9 DEPARTURE.....18.9 PRELIMINARY CLIMATE SUMMARY FOR APRIL 2009 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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 4/1 43/31/38/-3/0.13/0/015/02 24 SE 4/2 52/39/46/+4/0.02/0/000/00 20 SSE 4/3 58/45/52/+10/0.70//000/00 39 SSE AERO 38 MPH SSE TSTM 4/4 51/38/45/+3/0.01/0/015/02 48 WSW AERO 48 MPH WSW 4/5 58/37/48/+5/0/0/551/71 40 W AERO 37 MPH W 4/6 55/38/47/+4/1.42/0/047/006 42 SE AERO 40 MPH SE TSTM 4/7 50/34/42/-1/T/0/109/14 36 WSW AERO 35 MPH WSW 4/8 45/32/39/-5/0/0/149/19 33 SW AERO 31 MPH SW 4/9 60/34/47/+3/0/0/692/88 36 SSW AERO 33 MPH SSW 4/10 65/41/53/+9/0.18/0/544/69 37 SSW AERO 35 MPH SSW 4/11 44/33/39/-6/0.77/0.2/000/00 35 N AERO 30 MPH N 4/12 43/29/36/-9/0/0/541/68 45 NW AERO 43 MPH WNW 4/13 52/29/41/-4/0/0/734/92 38 W AERO 35 MPH W 4/14 58/37/48/+2/0/0/696/87 25 E 4/15 49/36/43/-3/0/0/650/81 35 NE AERO 31 MPH NE 4/16 50/34/42/-4/0/0/806/100 29 NNE 4/17 69/35/52/+5/0/0/695/86 37 W AERO 33 MPH W 4/18 64/44/54/+7/0.05/0/170/21 28 W 4/19 52/38/45/-2/0.03/0/773/95 33 NNE AERO 28 MPH NNE 4/20 51/36/44/-4/0.10/0/196/24 43 E AERO 39 MPH E 4/21 58/42/50/+2/0.95/0/000/00 43 E AERO 43 MPH S 4/22 62/45/54/+5/0.16/0/296/36 28 S 4/23 56/40/48/-1/0.01/0/668/81 43 W 4/24 70/40/55/+6/0/0/810/98 30 W 4/25 83/49/66/+16/T/0/647/78 29 S 4/26 88/56/72/+22/0/0/574/69 33 NE 4/27 72/49/61/+11/0/0/768/92 29 S 4/28 92/57/75/+24/0/0/704/84 37 SSW AERO 36 MPH S 4/29 63/44/54/+3/T/0/823/98 35 NW AERO 30 MPH NW TSTM * 4/30 67/41/54/+2/T/0/717/85 37 S * TSTM added to daily record for 4/29 ** Sunshine minutes and percentages for 4/20 through 4/30 are preliminary data and are subject to review. 5/1 morning low temperature 53F; our normal low is now 42F NEW DAILY RECORDS FOR APRIL 2009... New record high maximum temperature for April 25 of 83F surpasses 80F in 1942. New record high maximum temperature for April 26 of 88F surpasses 83F in 1908. New record high minimum temperature for April 26 of 56F surpasses 55F in 1985. Maximum temperature of 92F for April 28 equals record high maximum of 92F in 1990. Minimum temperature of 57F for April 28 equals record high minimum of 57F in 1935. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 1 HIGH 87F IN 1899 LOW 29F IN 1978 PRECIP 2.53 INCHES IN 1921 SNOWFALL TRACE IN 1905,1917,1921,1995. PEAK GUST 57 MPH NW IN 1974 RECORDS FOR MAY 2 HIGH 92F IN 2001 LOW 29F IN 1903 PRECIP 1.36 INCHES IN 2006 SNOWFALL 1.0 INS IN 1888 PEAK GUST 58 MPH S IN 1983 TODAY'S REPORT PREPARED BY: Stephanie Radner