BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, MAY 12, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME SPECTACULAR SPRING WEATHER TODAY...FULL SUNSHINE WITH TEMPERATURES IN THE MID TO UPPER 70S... A brief period of very light rain showers on Friday afternoon brought a trace of precipitation to the summit shortly before 3 PM EDT yesterday. The low temperature this morning was 46 degrees, which is one degree below the normal of 47. The temperature climbed quickly all morning and has reached the middle 70s as of early afternoon. The air is very dry with dew points in the upper 20s to low 30s, resulting in very good visibility of 70 to 75 miles. The sky has been almost completely clear all day with only a few high cirrus clouds appearing from time to time. Today's observations: 7 A.M. Weather: Clear, few cirrus distant NE-SE Temperature: 52F, Dew Point: 37F; Wind: W at 7 kts, Sea-level pressure: 30.15 inches Hg, rising Visibility: 75 miles 24-hour precip: Trace 6-hour min. temp: 46F BHO SA 1155 CLR 75 211/52/37/2707/015/ FEW CI DSNT NE-SE/ 8/001 53020 10052 20046 10 A.M. Weather: Sky clear Temperature: 66F, Dew Point: 26F; Wind: W at 13G22 kts, Sea-level pressure: 30.16 inches Hg, rising Visibility: 75 miles BHO SA 1455 SKC 75 213/66/26/2713G22/016/ 8/000 50002 1 P.M. Weather: Clear, few cirrus distant WSW-WNW Temperature: 74F, Dew Point: 33F; Wind: W at 13G20 kts, Wind: Direction variable WSW-NW Sea-level pressure: 30.11 inches Hg, falling Visibility: 70 miles 6-hour max. temp: 74F BHO SA 1755 CLR 70 197/74/33/2813G20/011/ FEW CI DSNT WSW-WNW WND 25V31/ 8/001 56016 10074 20052 WEATHER SUMMARY FOR FRIDAY, MAY 11 TEMPERATURE (DEGREES F) MAX.....62 NORMAL.....65 MIN.....42 NORMAL.....46 MEAN....52 NORMAL.....56 DEPARTURE FROM 30-YEAR NORMAL.......................-4 TOTAL DEPARTURE FOR THE MONTH......................-24 [-2.4 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY..............13 DEPARTURE..........+3 TOTAL HEATING UNITS FOR THE MONTH.............142 DEPARTURE.........+14 TOTAL HEATING UNITS FOR THE SEASON...........4856 DEPARTURE.......-1298 TOTAL HEATING UNITS LAST SEASON TO DATE......6009 DIFFERENCE......-1153 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............30 WNW AT 2:16 P.M. * AERO..................33 WNW AT 2:16 P.M. ASOS..................32 NW AT 2:16 P.M. DAVIS.................32 WNW AT 9:31 A.M. RMY 34 THE FASTEST MILE FOR YESTERDAY...........23 WNW AT 2:15 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............23 WNW AT 2:16 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........24 WNW AT 2:16 P.M. AVERAGE WIND SPEED AND DIRECTION.......11.4 WNW ASOS................10.9 DAVIS...............10.1 W [278 deg.] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace DEPARTURE..........-0.12 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........2.35 DEPARTURE..........+1.01 ASOS..............2.29 TOTAL PRECIPITATION FOR THE YEAR..........11.96 DEPARTURE..........-7.93 ASOS.............12.02 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE...........0.0 TOTAL SNOWFALL FOR THE MONTH................0.0 DEPARTURE..........-0.1 TOTAL SNOWFALL FOR THE SEASON..............24.2 DEPARTURE.........-35.9 PRELIMINARY CLIMATE SUMMARY FOR MAY 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 5/1 47/42/45/-8/0.65/0.0/000/00 33 SE AERO 36 MPH SE RMY 37 5/2 50/43/47/-6/0.05/0.0/000/00 16 ENE AERO 16 MPH ENE RMY 17 5/3 51/44/48/-5/0.08/0.0/000/00 14 SSE AERO 16 MPH SSE RMY N/A 5/4 56/47/52/-2/0.01/0.0/000/00 21 SSW AERO 25 MPH SSW RMY 23 5/5 57/46/52/-2/0.04/0.0/034/04 14 NE AERO 15 MPH NE RMY 15 5/6 58/45/52/-2/0.00/0.0/532/62 21 ENE AERO 21 MPH ENE RMY 21 5/7 67/48/58/+3/0.00/0.0/740/86 23 S AERO 25 MPH S RMY 25 5/8 57/48/53/-2/0.18/0.0/000/00 40 S AERO 46 MPH S RMY 46 5/9 61/54/58/+3/0.36/0.0/000/00 25 S AERO 28 MPH S RMY N/A 5/10 65/46/56/+1/0.98/0.0/.../.. 33 W AERO 36 MPH W RMY 37 5/11 62/42/52/-4/T/0.0/.../.. 30 WNW AERO 33 MPH WNW RMY 34 5/12 morning low temp: 46F; the normal low is now 47F DAILY RECORDS FOR MAY 2012 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 12 HIGH 88F IN 2001 LOW 29F IN 1907 PRECIP 1.49 INCHES IN 1968 PEAK GUST 76 MPH S IN 1974 RECORDS FOR MAY 13 HIGH 85F IN 1947 LOW 35F IN 1914, 2005 PRECIP 2.39 INCHES IN 2006 PEAK GUST 49 MPH NNW IN 1965 TODAY'S REPORT PREPARED BY: Mike Iacono