BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, APRIL 6, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME HEAVY RAIN BEGINS JUST AFTER 2 PM After a little sunshine very early this morning some light rain began before noon but amounted to only 0.01 inch. By 2:15 p.m. heavy rain had moved in and we had recorded almost a quarter inch in about 20 minutes. Today's Observations: 7 A.M. Weather: Scattered altocumulus, high overcast cirrostratus partly thin overhead thru north thru southeast Temperature: 42F, Dew point: 33F, Wind: E at 10 kts Sea-level pressure: 29.74 inches Hg, falling Visibility: 45 miles, 60 miles northeast to southeast 6-hour minimum temperature: 38F 24-hour precipitation: 0.00 inch BHO SA 1155 130 SCT 220 SCT 250 OVC 45 071/42/33/0910/974/ LINE ACC NE PTCHS AC CHAOTIC OVC PTLY THN OVHD-N-SE LWR CI LYR S-NW VSBY 60 NE-SE/ 8/087 55005 10042 20038 10 A.M. Weather: Overcast nimbostratus, virga and precip. observed to the south thru northwest, higher clouds distant northeast through southeast, precipitation approaching station Temperature: 44F, Dew point: 33F, Wind: ENE at 12 kts, Wind: direction gradually backing Sea-level pressure: 29.67 inches Hg, falling Visibility: 35 miles, NE-SE 60 miles, S-W 30 miles BHO SA 1455 E35 OVC 35 049/44/33/0712/967/ VIRGA S-NW PCPN 30 S-W APPRCHNG STN HIER CLDS VSB DSNT NE-SE VSBY NE-SE 60 S-W 30 N-E VIRGA SW-W WND GRDLY BACKING/ 8/02/ 56022 1 P.M. Weather: Overcast with stratus fractus, very light rain Temperature: 42F, Dew point: 40F, Wind: E at 12G22 kts, Wind: Peak wind gust 30 kts ENE @ 12:32 P.M. Sea-level pressure: 29.51 inches Hg, falling Visibility: 20 miles, 30 miles NW-N BHO SA 1755 E10 OVC 20R- 994/42/40/0812G22/951/ CIG RGD VSBY 30 W-NW LWRG SW 15 PK WND 0730/32/ PCPN VRY LGT/ 8/7// 56055 MANUAL 6001/ ASOS 60001 10046 20042 WEATHER SUMMARY FOR SUNDAY APRIL 5, 2009 TEMPERATURE (DEGREES F) MAX.....58 NORMAL.....52 MIN.....37 NORMAL.....34 MEAN....48 NORMAL.....43 DEPARTURE FROM 30-YEAR NORMAL................. +5 TOTAL DEPARTURE FOR THE MONTH.................+19 [+3.6 DEGREE/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............17 DEPARTURE.........-5 TOTAL HEATING UNITS FOR THE MONTH.............96 DEPARTURE........-19 TOTAL HEATING UNITS FOR THE SEASON..........5514 DEPARTURE........-65 TOTAL HEATING UNITS LAST SEASON TO DATE.....5245 DIFFERENCE......+269 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............40 W AT 8:03 A.M. AEROVANE.............37 W AT 8:03 A.M. ASOS.................38 W AT 8:04 A.M. DAVIS................37 W AT 8:03 A.M. FASTEST MILE FOR YESTERDAY..............29 W AT 8:03 A.M. * MAXIMUM 2-MINUTE ASOS AVERAGE...........28 W AT 1:34 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........27 WNW AT 11:32 A.M. AVERAGE............17.8 W ASOS...............16.1 DAVIS..............17.1 W [280 deg] * last of several occurrences.... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.00 DEPARTURE.........-0.15 ASOS...............0.00 TOTAL PRECIPITATION FOR THE MONTH...........0.86 DEPARTURE.........+0.11 ASOS...............0.91 TOTAL PRECIPITATION FOR THE YEAR...........10.94 DEPARTURE.........-3.44 ASOS..............12.04 # # Includes erroneous ASOS precipitation data on 1/1/09, 1/2/09 and 2/27/09. SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.........-0.1 TOTAL SNOWFALL FOR THE MONTH................0.0 DEPARTURE.........-0.6 TOTAL SNOWFALL FOR THE SEASON..............78.7 DEPARTURE........+21.2 PRELIMINARY CLIMATE SUMMARY FOR APRIL 2009 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 4/1 43/31/38/-3/0.13/0/015/02 24 SE 4/2 52/39/46/+4/0.02/0/000/00 20 SSE 4/3 58/45/52/+10/0.70//000/00 39 SSE AERO 38 MPH SSE TSTM 4/4 51/38/45/+3/0.01/0/.../.. 48 WSW AERO 48 MPH WSW 4/5 58/37/48/+5/0/0/551/71 40 W AERO 37 MPH W 4/6 morning low temp: 38F; our normal low is now 34F NEW DAILY RECORDS FOR APRIL 2009... None to date.. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): 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 RECORDS FOR APRIL 7 HIGH 86 IN 1929 LOW 13 IN 1982 PRECIP 1.72 IN. IN 1924 SNOWFALL 4.5 IN. IN 1967, 1996 PEAK GUST 65 MPH WNW IN 1982 TODAY'S REPORT PREPARED BY: Robert Skilling