BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, APRIL 16, 2010 ALL TIMES ARE IN EASTERN STANDARD TIME A trace of snow was observed on the summit and in lower areas this morning between 7 and 9AM EDT, but only a trace accumulated on the summit. Today's cold, wet weather marks the end of a very warm and sunny first half of April. The average daily temperature through yesterday has been over 11 degrees F above normal. The average daily bright sunshine for April has been over 70%. Today's observations: 7 A.M. Weather: Scattered stratus, overcast nimbostratus, few lower stratus drifting over and below summit Temperature: 35F, Dew point: 35F, Wind: E at 5 kts Sea-level pressure: 30.15 inches Hg, falling Visibility: 30 miles, 10 miles N to E 6-hour minimum temp: 34F 24-hour precipitation: 0.10 inches 24-hour snowfall: Trace BHO SA 1155 20 SCT E50 OVC 30 211/35/35/1005/015/ FEW LWR STRA DRFTG OVR AND BLO SMT VSBY N-E 10 TOTAL NEW SNW PST 24 HRS TRACE/ 8/62/ 58015 MANUAL 6010/ ASOS 60012 MANUAL 70010 ASOS 70012 10041 20034 10 A.M. Weather: Broken stratocumulus, overcast altostratus Temperature: 42F, Dew point: 38F, Wind: ESE at 7 kts Sea-level pressure: 30.09 inches Hg, falling Visibility: 30 miles 3-hour precipitation: 0.03 ins. 3-hour snowfall: Trace BHO SA 1455 E20 BKN 55 OVC 30 189/42/38/1207/009/ 8/52/ 58022 MANUAL 6003/ ASOS 60000 1 P.M. Weather: Broken stratus, overcast nimbostratus, light rain Temperature: 41F, Dew point: 38F, Wind: ENE at 6 kts Sea-level pressure: 30.03 inches Hg, falling Visibility: 8 miles, light rain 6-hour maximum temp: 43F 6-hour precipitation: 0.04 ins. 6-hour snowfall: Trace BHO SA 1755 E10 BKN 25 OVC 8R- 170/41/38/0606/003/ 8/72/ 56019 MANUAL 6004/ ASOS 60001 10043 20035 WEATHER SUMMARY FOR THURSDAY, APRIL 15 TEMPERATURE (DEGREES F) MAX.....60 NORMAL.....55 MIN.....40 NORMAL.....37 MEAN....50 NORMAL.....46 DEPARTURE FROM 30-YEAR AVERAGE................+4 TOTAL DEPARTURE FOR THE MONTH...............+172 (+11.3 DEGREES/DAY) HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............15 DEPARTURE........-4 TOTAL HEATING UNITS FOR THE MONTH...........151 DEPARTURE......-169 TOTAL HEATING UNITS FOR THE SEASON.........5247 DEPARTURE......-537 TOTAL HEATING UNITS LAST SEASON TO DATE....5729 DIFFERENCE.....-482 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............30 NE AT 12:56 P.M. * AEROVANE..............30 ENE AT 3:35 P.M. * ASOS..................30 E AT 1:09 P.M. DAVIS.................31 ENE AT 12:56 P.M. THE FASTEST MILE FOR YESTERDAY...........23 ENE AT 1:11 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............24 ENE AT 12:57 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........24 ENE AT 12:57 P.M. AVERAGE WIND SPEED AND DIRECTION.........13.1 W ASOS..................12.3 DAVIS.................13.3 N [003 DEG] * last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.10 DEPARTURE......-0.05 ASOS..............0.12 TOTAL PRECIPITATION FOR THE MONTH..........1.22 DEPARTURE......-1.03 ASOS..............1.22 TOTAL PRECIPITATION FOR THE YEAR..........29.13 DEPARTURE.....+13.25 ASOS.............29.32 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M........Trace DEPARTURE......-0.1 TOTAL SNOWFALL FOR THE MONTH..............Trace DEPARTURE......-1.6 TOTAL SNOWFALL FOR THE SEASON..............64.4 DEPARTURE......+5.9 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 our morning low temp: 34F; the normal low is now 37F 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 16 HIGH 87 IN 1896 LOW 23 IN 1943 PRECIP 2.45 IN. IN 1929 SNOWFALL 2.0 IN. IN 1904, 1962 PEAK GUST 73 MPH E IN 2007 RECORDS FOR APRIL 17 HIGH 93 IN 2002 LOW 21 IN 1908 PRECIP 1.68 IN 1954 SNOWFALL 1.0 IN. IN 1899 PEAK GUST 58 MPH NW IN 1994 TODAY'S REPORT PREPARED BY: Stephanie Radner