BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, APRIL 20, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME LIGHT RAIN OVERNIGHT AND THIS MORNING BRINGS MORE THAN HALF INCH OF RAIN...COOLER THAN LAST FEW DAYS IN THE 50S WITH MOSTLY HIGH CLOUDS FILTERING THE SUNSHINE THIS AFTERNOON... Steady rain began late Friday evening and continued until 8:10 AM EST this morning, bringing a total of 0.55 inch of rain. A cold front passed through around 4 AM EST today, which turned the wind direction from S to NW and dropped the temperature 8 degrees from 58 to 50 in the 4-5 AM hour. The high temperature of 62 for the day so far occurred back at midnight. Winds have remained gusty with a peak gust today of 43 mph S shortly after midnight and a gust of 41 mph W occuring at 11:15 AM EST today. The air is drying out from the dew points in the upper 50s on Friday. As of early afternoon the dew point has dropped into the middle 30s. As a result, the visiblity has climbed nicely today from just a few miles during the early rain to 70 miles this afternoon. Today's observations: 7 A.M. Weather: Light rain and fog, scattered stratocumulus, overcast nimbostratus, few stratus fractus all quadrants Temperature: 45F; Dew Point: 45F; Wind: NW at 13 kts, Wind: Peak wind of 26 kts NW at 6:22 A.M. Sea-level pressure: 29.78 ins. Hg, rising Visibility: 5 miles, visibility increasing rapidly 24-hour precip: 0.52 inch 6-hour precip: N/A 6-hour min. temp: 45F BHO SA 1155 5 SCT E15 OVC 5R-F 084/45/45/3113/978/ FEW STFRA ALQDS VSBY INCR RAPIDLY PK WND 3126/22/ 8/72/ 51044 60/// 70052 10061 20045 10 A.M. Weather: Scattered stratocumulus (2 layers), broken altocumulus, overcast cirrostratus, few lower stratocumulus, few cumulus fractus all quadrants, breaks in overcast overhead, high clouds visible overhead, hazy Temperature: 48F; Dew Point: 39F; Wind: NW at 13G20 kts Sea-level pressure: 29.86 ins. Hg, rising Visibility: 50 miles, visibility E-S 40 WNW-NW 60, hazy 3-hour precip.: 0.03 inch BHO SA 1455 20 SCT 50 SCT E75 BKN 220 OVC 50 113/48/39/3113G20/986/ FEW LWR SC FEW CUFRA ALQDS BINOVC OVHD HIR CLDS VSBL OVHD VSBY E-S 40 WNW-NW 60 SUN DMLY VSBL HAZY/ 8/578 53029 6003/ 1 P.M. Weather: Scattered cumulus, overcast cirrostratus, breaks in overcast distant WSW-NW, few higher clouds visible Temperature: 54F; Dew Point: 34F; Wind: W at 13G24 kts, Wind: Peak wind of 26 kts. W at 12:33 P.M. Sea-level pressure: 29.87 ins. Hg, rising Visibility: 70 miles 6-hour max temp: 55F 6-hour precip.: 0.03 inch BHO SA 1755 45 SCT E250 OVC 70 116/54/34/2713G24/987/ BINOVC DSNT WSW-NW FEW HIR CLDS VSBL PK WND 2726/33/ 8/108 51003 6003/ 10055 20045 WEATHER SUMMARY FOR FRIDAY, APRIL 19 TEMPERATURE (DEGREES F) MAX.....72 NORMAL.....57 MIN.....50 NORMAL.....39 MEAN....61 NORMAL.....48 DEPARTURE FROM 30-YEAR NORMAL...................+13 TOTAL DEPARTURE FOR THE MONTH...................+43 [+2.1 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............4 DEPARTURE.........-13 TOTAL HEATING UNITS FOR THE MONTH...........346 DEPARTURE.........-43 TOTAL HEATING UNITS FOR THE SEASON.........5366 DEPARTURE........-506 TOTAL HEATING UNITS LAST SEASON TO DATE....4563 DIFFERENCE.......+803 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............47 SSW AT 1:47 P.M. AERO....................48 SSW AT 7:15 P.M. ASOS....................48 SSW AT 10:59 P.M. DAVIS...................49 SSW AT 10:14 P.M. RMY: 50 THE FASTEST MILE FOR YESTERDAY.............39 SSW AT 10:14 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE..............37 SSW AT 11:00 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............36 SSW AT 10:15 P.M. AVERAGE WIND SPEED AND DIRECTION.........23.3 SSW ASOS..................21.8 DAVIS.................20.9 SSW [195 deg] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.52 DEPARTURE...........+0.39 ASOS..............0.51 TOTAL PRECIPITATION FOR THE MONTH..........1.70 DEPARTURE...........-1.37 ASOS..............1.64 TOTAL PRECIPITATION FOR THE YEAR..........15.79 DEPARTURE...........-1.28 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............-2.6 TOTAL SNOWFALL FOR THE SEASON.............99.0 DEPARTURE...........+36.7 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/460/60 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/-1/0.00/0.0/391/50 51 S AERO 46 MPH S RMY 50 4/8 65/43/54/+10/T/0.0/494/63 29 SSW AERO 22 MPH SSW RMY N/A 4/9 72/44/58/+14/T/0.0/456/58 35 WNW AERO 35 MPH WNW RMY 39 TSTM 4/10 64/43/54/+9/0.13/0.0/426/54 23 SE AERO 20 MPH SE RMY 25 4/11 52/40/46/+1/0.09/0.0/063/08 18 ENE AERO 14 MPH ENE RMY N/A 4/12 40/34/37/-8/0.58/T/000/00 38 E AERO 32 MPH E RMY 41 4/13 52/34/43/-3/0.04/0.0/128/16 31 NNE AERO 27 MPH NNE RMY 21 4/14 52/36/44/-2/0.00/0.0/216/27 31 WNW AERO 27 MPH WNW RMY 32 4/15 55/35/45/-2/0.00/0.0/514/64 21 ESE AERO 15 MPH S RMY N/A 4/16 62/38/50/+3/T/0.0/540/67 44 S AERO 40 MPH S RMY 45 4/17 67/48/58/+11/T/0.0/769/95 29 SSW AERO 25 MPH SSW RMY N/A 4/18 65/43/54/+6/0.00/0.0/.../.. 30 S AERO 25 MPH S RMY N/A 4/19 72/50/61/+13/.../0.0/.../.. 47 SSW AERO 48 MPH SSW RMY 50 4/20 morning low temp: 45F; the normal low is now 40F 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 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: Mike Iacono/Jonathan O'Brien