BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, APRIL 11, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME LOW CLOUDS AND FOG EARLY TODAY GIVE WAY TO A MOSTLY CLOUDY SKY BY AFTERNOON Temperatures are running much cooler today after a high of 64F Wednesday afternoon. Clouds and easterly winds are holding our high temperature to the upper 40's to around 50 degrees today. Only light precipitation amounts of well under one quarter of an inch during the past 24 to 36 hours continues to leave April with a deficit of over one inch. The mild temperatures of the past several days brought the April average up to over 2 degrees above the 30-year normal for the first 10 days of the month. Today's observations: 7 A.M. Weather: Overcast stratus, few stratus fractus drifting below and occasionally over the summit, ceiling and visibiity increased past hour but conditions are variable, very light drizzle occurring, drizzle began 6:15 A.M. EST and continued Temperature: 44F; Dew Point: 44F; Wind: N at 8 kts, Sea-level pressure: 29.95 ins. Hg, rising slightly Visibility: 2 miles, except 1/4 mile N-NE, stratus/stratus fractus, drifting below and occasionally over summit, very light drizzle 6-hr precip: 0.01 inch 24-hr precip: 0.09 inch 6-hour min. temp: 43F BHO SA 1155 E4 OVC 2L-F 143/44/44/0108/995/ FEW STFRA DRFTG BLO/OCNL OVR SMT VSBY N-NE 1/4 CIG/VSBY INCRSD PST HR CDNS VRBL LB15 CTD/ 8/6// 51035 ASOS 60002 MANUAL 60001 ASOS 70007 MANUAL 70009 10045 20043 10 A.M. Weather: Overcast stratus, light drizzle and fog Temperature: 42F; Dew Point: 42F; Wind: ENE at 9 kts, Wind: Direction variable NNE-E Sea-level pressure: 30.01 ins. Hg, rising then more rapidly Visibility: 2 1/2 miles, except 3 miles E, light drizzle and fog 3-hr precip: trace BHO SA 1455 E10 OVC 21/2L-F 163/42/42/0609/001/ VSBY E 3 WND 02V09 LB30 CTD/ 8/6// 53020 6000/ 1 P.M. Weather: Overcast stratocumulus, few lower cumulus, line of clearing distant SW-NW with higher clouds visible behind it, distant haze Temperature: 46F; Dew Point: 37F; Wind: ENE at 10 kts, Wind: Direction variable NNE-E Sea-level pressure: 30.04 ins. Hg, rising then more slowly Visibility: 40 miles, except 50 miles WNW, distant haze all quadrants 6-hr precip: trace 6-hr max. temp: 49F BHO SA 1755 E22 OVC 40 173/46/37/0710/004/ FEW LWR CU LINE OF CLRG DSNT SW-NW/HIER CLDS VSB VSBY WNW 50 DSNT HZ WND 02V09/ 8/8// 51010 MANUAL 6000/ 10049 20042 WEATHER SUMMARY FOR WEDNESDAY, APRIL 10 TEMPERATURE (DEGREES F) MAX.....64 NORMAL.....53 MIN.....43 NORMAL.....36 MEAN....54 NORMAL.....45 DEPARTURE FROM 30-YEAR NORMAL....................+9 TOTAL DEPARTURE FOR THE MONTH...................+24 [+2.2 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............11 DEPARTURE..........-9 TOTAL HEATING UNITS FOR THE MONTH...........198 DEPARTURE.........-24 TOTAL HEATING UNITS FOR THE SEASON.........5218 DEPARTURE........-488 TOTAL HEATING UNITS LAST SEASON TO DATE....4485 DIFFERENCE.......+733 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............23 SE AT 5:33 P.M. AERO....................20 SE AT 5:33 P.M. ASOS....................23 SE AT 5:30 P.M. DAVIS...................23 SE AT 5:33 P.M. RMY: 25 THE FASTEST MILE FOR YESTERDAY.............17 SE AT 5:32 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE..............16 SE AT 5:37 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............16 SE AT 5:31 P.M. AVERAGE WIND SPEED AND DIRECTION..........6.7 SSE ASOS...................6.5 DAVIS..................6.4 ESE [110 deg] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.09 DEPARTURE...........-0.09 ASOS..............0.07 TOTAL PRECIPITATION FOR THE MONTH..........0.50 DEPARTURE...........-1.20 ASOS..............0.48 TOTAL PRECIPITATION FOR THE YEAR..........14.59 DEPARTURE...........-1.11 ASOS..............N/A* *ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals 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............-1.6 TOTAL SNOWFALL FOR THE SEASON.............99.0 DEPARTURE...........+37.7 PRELIMINARY CLIMATE SUMMARY FOR APRIL 2013 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust RMY: RMY = R.M. Young wind gust recording system added 8/9/2011 TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 4/1 61/31/46/+5/0.34/0.0/458/60 40 W AERO 44 MPH WNW RMY 46 TSTM 4/2 40/27/34/-7/T/T/460/460/60 45 W AERO 42 MPH W RMY 47 4/3 45/27/36/-6/0.00/0.0/755/98 44 W AERO 43 MPH W RMY 47 4/4 55/26/41/-1/0.00/0.0/719/93 30 WSW AERO 27 MPH WSW RMY 31 4/5 59/36/48/+5/0.00/0.0/403/52 33 NNW AERO 28 MPH NNW RMY 38 4/6 47/30/39/-4/0.00/0.0/747/96 38 NW AERO 35 MPH NW RMY 40 4/7 52/31/42/-1/0.00/0.0/.../.. 51 S AERO 46 MPH S RMY 50 4/8 65/43/54/+10/T/0.0/.../.. 29 SSW AERO 22 MPH SSW RMY N/A 4/9 72/44/58/+14/T/0.0/.../.. 35 WNW AERO 35 MPH WNW RMY 39 TSTM 4/10 64/43/54/+9/0.13/0.0/.../.. 23 SE AERO 20 MPH SE RMY 25 4/11 the morning low temp: 43F; the normal low is now 36F DAILY RECORDS FOR APRIL 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 11 HIGH 78 IN 1945 LOW 19 IN 1909 PRECIP 1.72 IN. IN 2003 SNOWFALL 9.5 IN. IN 1958 PEAK GUST 65 MPH NW IN 1963 RECORDS FOR APRIL 12 HIGH 82 IN 1945 LOW 17 IN 1926 PRECIP 1.51 IN. IN 1993 SNOWFALL 12.0 IN. IN 1894 PEAK GUST 65e MPH W IN 1978 TODAY'S REPORT PREPARED BY: Robert Skilling