BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, APRIL 13, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME AFTER A MORNING IN THE CLOUDS, SUN BREAKS THROUGH AND TEMPS CLIMB Visibility from the summit suffered this morning as we were stuck in the low clouds with light drizzle ending shortly after 8:00 AM. Total precipitation from Friday's storm was 0.47 inch, which still leaves our April total 1.33 inches short of normal. The storm also packed significant gusts of 38 MPH and speeds averaged over 20 MPH between 7:00 and 12:00 PM. Drier air came in slowly from the NW throughout the day and clouds began to break around 11:00 AM. Temperatures climbed up into the upper 40s by the afternoon, which is considerably warmer than yesterday's high of 38F. Today's observations: 7 A.M. Weather: Low overcast stratocumulus, light rain/drizzle and fog Temperature: 35F; Dew Point: 33F; Wind: NNW at 8 kts, Sea-level pressure: 29.84 ins. Hg, rising then rising more slowly Visibility: 2 miles, fog all quadrants 24-hr precip: 0.47 inch 6-hour max. temp: 36 6-hour min. temp: 34 BHO SA 1155 E10 OVC 2R-F 106/35/33/3408/984/ FEW STFRA DRFTG OVR SMT/ 8/8// 51018 60/// 70047 10036 20034 10 A.M. Weather: Overcast stratocumulus with few breaks Temperature: 39F; Dew Point: 35F; Wind: NW at 6 kts, Sea-level pressure: 29.88 ins. Hg, slowly rising Visibility: 55 miles, light distant haze BHO SA 1455 E13 OVC 55 119/39/35/3206/988/ DSNT HZ ALQDS/ 8/5// 51013 1 P.M. Weather: Broken cumulus and altocumulus, stratocumulus layer distant offshore NE-SE Temperature: 48F; Dew Point: 36F; Wind: NNW at 6 kts, Sea-level pressure: 29.85 ins. Hg, increasing then decreasing Visibility: 70 miles, light distant haze 6-hour max temp: 48 F 6-hour min temp: 35 F 6-hour precip: Trace BHO SA 1755 E30 BKN 50 BKN 70 108/48/36/3406/985/ SC LYR DSNT OFSHR NE-SE LT DSNT HZ ALQDS/ 8/54/ 58011 6000/ 10048 20035 WEATHER SUMMARY FOR FRIDAY, APRIL 12 TEMPERATURE (DEGREES F) MAX.....38 NORMAL.....54 MIN.....34 NORMAL.....36 MEAN....36 NORMAL.....45 DEPARTURE FROM 30-YEAR NORMAL....................-9 TOTAL DEPARTURE FOR THE MONTH...................+16 [+1.3 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............29 DEPARTURE..........+9 TOTAL HEATING UNITS FOR THE MONTH...........246 DEPARTURE.........-16 TOTAL HEATING UNITS FOR THE SEASON.........5266 DEPARTURE........-480 TOTAL HEATING UNITS LAST SEASON TO DATE....4519 DIFFERENCE.......+747 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............38 E AT 9:06 A.M. AERO....................32 E AT 9:00 A.M. ASOS....................38 E AT 9:07 A.M. DAVIS...................37 E AT 9:06 A.M. RMY: 41 THE FASTEST MILE FOR YESTERDAY.............30 E AT 9:07 A.M. * MAXIMUM 2-MINUTE ASOS AVERAGE..............29 E AT 9:07 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............28 E AT 9:01 A.M. AVERAGE WIND SPEED AND DIRECTION..........16.3 E ASOS...................15.1 DAVIS..................14.0 E [79 deg] *last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.47 DEPARTURE...........+0.30 ASOS..............0.46 TOTAL PRECIPITATION FOR THE MONTH..........1.18 DEPARTURE...........-0.86 ASOS..............1.13 TOTAL PRECIPITATION FOR THE YEAR..........15.60 DEPARTURE...........-0.77 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.......Trace DEPARTURE............-0.1 TOTAL SNOWFALL FOR THE MONTH.............Trace DEPARTURE............-1.9 TOTAL SNOWFALL FOR THE SEASON.............99.0 DEPARTURE...........+37.4 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/460/60 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 52/40/46/+1/..../0.0/.../.. 18 ENE AERO 14 MPH ENE RMY N/A 4/12 40/34/37/-8/0.47/T/.../.. 38 E AERO 32 MPH E RMY 41 4/13 the morning low temp: 36F; 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 13 HIGH 85 IN 1945 LOW 22 IN 1939 PRECIP 2.51 IN. IN 2004 SNOWFALL 6.8 IN. IN 1933 PEAK GUST 59 MPH SSW IN 1995 RECORDS FOR APRIL 14 HIGH 80 IN 1945 LOW 21 IN 1923 PRECIP 2.22 IN. IN 1895 SNOWFALL 8.4 IN. IN 1953 PEAK GUST 71e MPH W IN 1943 TODAY'S REPORT PREPARED BY: Forrest Iwanik