BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, APRIL 5, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME MOSTLY SUNNY TO PARTLY CLOUDY COOLER BUT NOT AS VERY DRY TODAY AS IN PAST DAYS A cold front passed early last evening accompanied by the peak wind gust of the day to near or a little over 40 MPH from the NW. While the air mass behind the front was cooler it was not nearly as dry as it was during the past couple of days. Relative humidity today has fallen to the 30% range rather than the near 20% values of the past couple of days. A few very light rain showers followed in the immediate wake of the front but that was it and the extreme absence of significant precipitation goes on and on. Temperatures today are near the seasonal normals rising from 33F this morning to the low 50's this afternoon. Visibility is way up to over 80 miles early this afternoon. Today's observations: 7 A.M. Clear, stratocumulus, few lonticulars, overhead thru SE and SW-N, cirrus distant NNW-N Temperature: 38F, Dew point: 29F, Wind: NNW at 10 kts, Wind: Direction variable W-N Sea-level pressure: 29.74 inches Hg, rising unsteadily Visibility: 65 miles, mountain in cloud 70 NW 24-hour precip: trace 6-hour min. temp: 33F BHO SA 1155 CLR 65 072/38/29/3310/974/ SC/FEW SCSL OVHD-SE AND SC/SCSL SW-N FEW CI DSNT NNW-N MTN INCLD 70 NW WND 28V35/ 8/501 53020 10038 20033 10 A.M. Weather: Scattered to occasionally broken stratocumulus Temperature: 45F, Dew Point: 23F; Wind: NW at 15G20 kts, Wind: Direction variable WSW-NNW Sea-level pressure: 29.77 inches Hg, rising Visibility: 75 miles BHO SA 1455 44 SCT 75 080/45/23/3115G20/977/ SCT V BKN MSTLY CLR SKY DSNT NE-E GST 23 KTS PST HR WND 24V34 LGT DSNT HZ/ 8/500 53008 1 P.M. Weather: Broken stratocumulus, few lower cumulus Temperature: 48F, Dew Point: 23F; Wind: NW at 9 kts, Wind: Gust to 21 kts past hour Wind: Direction variable W-N Sea-level pressure: 29.78 inches Hg, rising Visibility: 85 miles 6-hour max. temp: 49F BHO SA 1755 E55 BKN 85 084/48/23/3109/978/ FEW LWR CU GST TO 21 KTS PST HR WND 26V35/ 8/800 53004 10049 20038 WEATHER SUMMARY FOR WEDNESDAY, APRIL 4 TEMPERATURE (DEGREES F) MAX.....62 NORMAL.....51 MIN.....38 NORMAL.....33 MEAN....50 NORMAL.....42 DEPARTURE FROM 30-YEAR NORMAL.......................+8 TOTAL DEPARTURE FOR THE MONTH......................+13 [+3.1 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY..............15 DEPARTURE..........-8 TOTAL HEATING UNITS FOR THE MONTH..............81 DEPARTURE.........-12 TOTAL HEATING UNITS FOR THE SEASON...........4366 DEPARTURE.......-1191 TOTAL HEATING UNITS LAST SEASON TO DATE......5496 DEPARTURE.......-1130 ** ** there has been no error is these daily heating units and departures as was inadvertently reported here yesterday. The correct difference or departure is on here from both the seasonal normal and last year's total through the current date. PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............40 NW AT 6:37 P.M. AERO..................39 NW AT 6:37 P.M. ASOS..................41 NW AT 6:37 P.M. DAVIS.................41 NW AT 6:36 P.M. RMY 43 MPH THE FASTEST MILE FOR YESTERDAY...........31 NW AT 6:36 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............31 NW AT 6:37 P.M. DAVIS MAXIMUM 2-MINUTE AVERAGE...........30 NW AT 6:37 P.M. AVERAGE WIND SPEED AND DIRECTION.......13.3 WNW ASOS................12.6 DAVIS...............11.6 NW [310 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M... TRACE DEPARTURE..........-0.17 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.18 DEPARTURE..........-0.50 ASOS..............0.17 TOTAL PRECIPITATION FOR THE YEAR...........6.27 DEPARTURE..........-8.41 ASOS..............6.32 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..........-0.5 TOTAL SNOWFALL FOR THE SEASON..............24.2 DEPARTURE.........-33.2 PRELIMINARY CLIMATE SUMMARY FOR APRIL 2012 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 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 50/34/42/+1/0.14/0.0/.../.. 20 SSW AERO 20 MPH SSW RMY N/A 4/2 51/35/43/+2/0.04/T/.../.. 35 NNW AERO 33 MPH NNW RMY 35 4/3 57/31/44/+2/0.00/0.0/.../.. 36 NW AERO 37 MPH NW RMY 40 4/4 62/38/50/+8/T/0.0/.../.. 40 NW AERO 39 MPH NW RMY 43 4/5 our morning low temp: 33F; the normal low is now 34F DAILY RECORDS FOR APRIL 2012 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: Robert Skilling If you do not wish to receive this Daily Discussion and Climate Summary from the Blue Hill Observatory, please send an email to sitemaster@bluehill.org.