BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, APRIL 5, 2011 ALL TIMES ARE IN EASTERN STANDARD TIME STRONG SOUTHERLY WINDS, OCCASSIONAL LIGHT TO MODERATE RAIN SHOWERS Winds have been quite strong for much of the day. Southerly winds have been frequently gusting 40-50 mph. The strongest gust of the day of 52 mph from the south occurred at 9:40 AM EST. Just prior to 1 PM EST, the wind direction shifted from SSW to W with the passage of a cold front. Winds are not as strong since the front passage, but still occassionally gusting 25-30 mph. Also with the passage of the front, the temperature dropped from a high of 61F near noon EST to the mid 40s two and a half hours later. Rainfall since 7 AM EST on Monday has amounted to 0.46 inches through 1 PM EST. That brings our total for the month above 1 inch. A thunderstorm was observed on the summit Monday afternoon during the 2-3 PM EST hour. Today's observations: 7 A.M. Weather: Broken stratocumulus, overcast stratus, higher stratus layer occassionally visible, thin fog/haze Temperature: 57F, Dew point: 55F; Wind: S at 28G39 kts Wind: Peak wind 39 kts from the S at 6:53 AM EST Wind: Direction variable SSE to SSW Sea-level pressure: 29.31 ins. Hg, falling Visibility: 12 miles, thin fog/haze 24-hour precip: 0.43 6-hour min. temp: 46F BHO SA 1155 E5 BKN 10 OVC 12 924/57/55/1828G39/931/ HIER STRA LYR OCNLY VSBL THN FG/HZ PK WND 1839/53 WND 15V21/ 8/7// 58010 MANUAL 70043 ASOS 70045 10057 20046 10 A.M. Weather: Light drizzle, fog, broken stratocumulus, overcast nimbostratus, higher nimbostratus layer occassionally visible, light rain began 9:31 AM EST and ended at 9:36 AM EST, precipitation very light and intermittent Temperature: 56F, Dew point: 55F; Wind: S at 25G41 kts, Wind: Peak wind 45 kts from the S at 9:40 AM EST Wind: Direction variable SE to S Sea-level pressure: 29.20 inches Hg, falling Visibility: 6 miles, light drizzle, fog 3-hour precip: 0.01 inch BHO SA 1455 E3 BKN 5 OVC 6L-F 887/56/55/1725G41/920/ HIER NS LYR OCNLY VSBL PK WND 1745/40 WND 13V19 R-B31E36 PCPN VRY LGT AND INTMT/ 8/7// 58037 MANUAL 60001 ASOS 60000 1 P.M. Weather: Moderate rain, fog, scattered stratocumulus, broken stratocumulus, overcast nimbostratus, few lower stratus fractus SW-N, line of moderate rain showers NNE-OVHD-SSW moving E, light rain began 12:04 PM EST, moderate rain began 12:40 PM EST Temperature: 49F, Dew point: 49F; Wind: SSW at 23G38 kts, Wind: Peak wind 43 kts from the SSW at 12:35 PM EST Wind: Shift at 12:52 PM EST (frontal passage) Sea-level pressure: 29.20 inches Hg, rising slightly Visibility: 4 miles, variable 3 to 6 miles, N-NE and S-SW 3 miles, ENE-SE and SW-NNW 6 miles, moderate rain, fog 6-hour precip: 0.03 inch 6-hour max. temp. 61F BHO SA 1755 8 SCT E15 BKN 25 OVC 4VRF 889/49/49/2023G38/920/ FEW LWR STFRA SW-N VSBY N-NE AND S-SW 3 ENE-SE AND SW-NNW 6 VSBY 3V6 LINE RW NNE-OVHD-SSW MOVG E PK WND 2043/35 WND SHFT/FROPA 52 R-B04 RB40/ 8/7// 51002 MANUAL 60003 ASOS 60001 10061 20049 WEATHER SUMMARY FOR MONDAY, APRIL 4 TEMPERATURE (DEGREES F) MAX.....46 NORMAL.....51 MIN.....38 NORMAL.....33 MEAN....42 NORMAL.....42 DEPARTURE FROM 30-YEAR NORMAL....................0 TOTAL DEPARTURE FOR THE MONTH...................-5 [-1.5 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............23 DEPARTURE.........0 TOTAL HEATING UNITS FOR THE MONTH............98 DEPARTURE........+5 TOTAL HEATING UNITS FOR THE SEASON.........5496 DEPARTURE.......-61 TOTAL HEATING UNITS LAST SEASON TO DATE....5127 DIFFERENCE.....+369 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............33 SE AT 11:00 A.M. AEROVANE...............36 SE AT 11:57 A.M. ASOS...................32 SSE AT 11:22 A.M. DAVIS..................32 SE AT 11:22 A.M. THE FASTEST MILE FOR YESTERDAY............26 SE AT 1:45 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE.............24 SSE AT 1:47 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............26 SE AT 1:47 P.M. AVERAGE WIND SPEED AND DIRECTION........13.8 SE ASOS.................12.9 DAVIS................12.4 SE [142 DEG] * last of several occurrences.... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M... 0.43 DEPARTURE........+0.28 ASOS..............0.45 TOTAL PRECIPITATION FOR THE MONTH..........1.14 DEPARTURE........+0.54 ASOS............1.12 TOTAL PRECIPITATION FOR THE YEAR..........14.75 DEPARTURE........+0.52 ASOS..............15.51** ** ASOS data is in error due to system failure on 1/12-13 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M........Trace DEPARTURE........-0.1 TOTAL SNOWFALL FOR THE MONTH................1.6 DEPARTURE........+1.1 TOTAL SNOWFALL FOR THE SEASON..............96.8 DEPARTURE.......+39.4 PRELIMINARY CLIMATE SUMMARY FOR MARCH/APRIL 2011 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 36/31/34/-7/0.71/1.6/.../.. 35 N AERO 40 MPH N 4/2 50/33/42/0/T/0.0/.../... 38 W AERO 41 MPH W 4/3 53/35/44/+2/0.00/0.0/.../.. 41 W AERO 42 MPH W 4/4 46/38/42/0/.../T/000/00 33 SE AERO 36 MPH SE 4/5 our morning low temp: 46F; the normal low is now 34F DAILY RECORDS FOR APRIL 2011 None so far DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 5 HIGH 81 IN 1928 LOW 15 IN 1995 PRECIP 2.15 IN. IN 1987 SNOWFALL 4.0 IN. IN 1898 PEAK GUST 76 MPH WNW IN 1963 RECORDS FOR APRIL 6 HIGH 82 IN 1921 LOW 16 IN 1982 PRE 1.72 INS IN 1886 SNOW 12.3 INS IN 1982 WIND 71e MPH WNW IN 1940 TODAY'S REPORT PREPARED BY: Sean Fankhauser