BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, APRIL 20, 2010 ALL TIMES ARE IN EASTERN STANDARD TIME WARM TEMPERATURES RETURN As of 1 PM EST, the high temperature for today is 68F. Today, we resume our above average temperatures after a brief interruption over the last 4 days. The last such streak of at or below normal temperatures was back on February 5-8. A brief, very light rain shower was noted on the summit around 12:15 PM EST this afternoon. Today's observations: 7 A.M. Weather: Clear, few altocumulus southwest thru east-southeast Temperature: 49F, Dew point: 40F, Wind: WNW at 10 kts, Sea-level pressure: 29.93 inches Hg, rising Visibility: 75 miles 6-hour minimum temp: 43F BHO SA 1155 CLR 75 135/49/40/2910/993/ FEW AC SW-ESE/ 8/040 53007 10049 20043 10 A.M. Weather: Scattered altocumulus/altocumulus lenticularis, cumulus developing all quadrants except east-northeast thru east-southeast, cumulus few moderate tops, altocumulus overhead Temperature: 62F, Dew point: 39F, Wind: WNW at 9 kts, Wind: Direction variable WSW to N Sea-level pressure: 29.91 inches Hg, falling Visibility: 70 miles BHO SA 1455 80 SCT 70 130/62/39/2909/991/ CU FRMG ALQDS XCPT ENE-ESE FEW MDT TOPS AC OVHD WND 24V35/ 8/840 58005 1 P.M. Weather: Broken stratocumulus/cumulus, broken altocumulus, virga northeast and south-southeast thru south, rain began 1212PM EST ended 1219PM EST, precipitation very light Temperature: 66F, Dew point: 32F, Wind: WNW at 13G23 kts, Wind: Direction variable SSW to NW Sea-level pressure: 29.86 inches Hg, falling Visibility: 65 miles 6-hourly max. temp: 68F 6-hour precip: Trace BHO SA 1755 E75 BKN 100 BKN 65 111/66/32/2813G23/986/ VIRGA NE AND SSE-S RB12E19 PCPN VRY LGT WND 20V32/ 8/260 58019 MANUAL 60000 10068 20049 WEATHER SUMMARY FOR MONDAY, APRIL 19 TEMPERATURE (DEGREES F) MAX.....58 NORMAL.....57 MIN.....35 NORMAL.....38 MEAN....47 NORMAL.....47 DEPARTURE FROM 30-YEAR AVERAGE.................0 TOTAL DEPARTURE FOR THE MONTH...............+153 (+7.9 DEGREES/DAY) HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............18 DEPARTURE.........0 TOTAL HEATING UNITS FOR THE MONTH...........243 DEPARTURE......-150 TOTAL HEATING UNITS FOR THE SEASON.........5339 DEPARTURE......-518 TOTAL HEATING UNITS LAST SEASON TO DATE....5796 DIFFERENCE.....-457 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............30 WNW AT 7:46 A.M. AEROVANE..............32 WNW AT 7:47 A.M. ASOS..................30 NW AT 7:46 A.M. DAVIS................ 32 WNW AT 7:46 A.M. THE FASTEST MILE FOR YESTERDAY...........21 WNW AT 6:21 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............21 NW AT 5:51 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........23 WNW AT 5:51 P.M. AVERAGE WIND SPEED AND DIRECTION.........13.1 WNW ASOS..................12.3 DAVIS.................13.6 NW [305 DEG] * last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE......-0.14 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.83 DEPARTURE......-0.85 ASOS..............1.77 TOTAL PRECIPITATION FOR THE YEAR..........29.74 DEPARTURE.....+13.29 ASOS.............29.87 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE......-0.1 TOTAL SNOWFALL FOR THE MONTH..............Trace DEPARTURE......-2.0 TOTAL SNOWFALL FOR THE SEASON..............64.4 DEPARTURE......+5.5 PRELIMINARY CLIMATE SUMMARY FOR APRIL 2010 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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 4/1 59/43/51/+10/T/0/359/47 24 NNW AERO 30 MPH NNW 4/2 67/46/57/+15/0.00/0/728/95 21 SSE 4/3 75/45/60/+18/0.00/0/731/95 26 SSE 4/4 76/45/61/+19/0.00/0/617/80 27 W AERO 29 MPH W 4/5 72/53/63/+20/0.00/0/635/82 37 SSE AERO 40 MPH SSE 4/6 68/50/59/+16/T/0/202/26 23 W 4/7 90/45/68/+25/0.00/0/578/74 36 WSW AERO 41 MPH WSW 4/8 65/45/55/+11/0.00/0/611/78 31 ENE 4/9 56/37/47/+3/1.12/0/000/00 35 W AERO 39 MPH W 4/10 56/37/47/+3/0.00/0/663/84 45 W AERO 52 MPH W 4/11 69/47/58/+13/0.00/0/506/64 36 W AERO 40 MPH W 4/12 61/43/52/+7/0.00/0/635/80 31 W AERO 33 MPH W 4/13 56/39/48/+3/0.00/0/613/77 23 S 4/14 65/37/51/+5/0.00/0/760/95 28 WNW AERO 32 MPH WNW 4/15 60/40/50/+4/0.00/0/739/92 30 NE 4/16 43/34/39/-7/.../T/000/00 26 E 4/17 41/36/39/-8/.../T/000/00 * 27 ENE 4/18 49/37/43/-4/0.07/0/.../.. 29 WNW 4/19 58/35/47/0/0.00/0/.../.. 30 WNW AERO 32 MPH WNW * trace of snow added 4/20 the morning low temp: 43F; the normal low is 39F NEW DAILY RECORDS FOR APRIL 2010 4/4 - new record high maximum temperature of 76F; surpasses 71F in 1950. 4/5 - new record high minimum temperature of 53F; surpasses 52F in 1981 4/7 - new record high maximum temperature of 90F; surpasses 86F in 1929 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 20 HIGH 88 IN 1927 LOW 18 IN 1897 PRECIP 1.14 IN 1972 SNOWFALL 2.5 IN. IN 1904, 1972 PEAK GUST 76 MPH WNW IN 1963 RECORDS FOR APRIL 21 HIGH 85 IN 1923 LOW 22 IN 1908 PRECIP 3.18 IN. IN 1991 SNOWFALL 0.8 IN. IN 1947 PEAK GUST 76e MPH NE IN 1940 TODAY'S REPORT PREPARED BY: Sean Fankhauser