BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, JUNE 23, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME FIRST THREE-DAY HEAT-WAVE OF 2012 ENDED YESTERDAY... FRIDAY HIGH TEMPERATURE OF 93 AND LOW OF 69 BOTH TIE RECORDS FOR THE DATE...THUNDERSTORM FRIDAY EVENING BROUGHT A PERIOD OF MODERATE RAIN...COOLER AND MOSTLY SUNNY SO FAR TODAY WITH BUILDING CUMULUS THIS AFTERNOON... The high temperature on Friday reached the 90s for the third straight day making this the first heat wave of 2012. The last heat wave occurred on July 21-23, 2011 with highs of 93, 99 and 90 on those days. Friday's high of 93 deg F tied the record for the date set previously in 1921, and the low temperature of 69, which occurred in the last hours of the day, also tied the previous record for the date set in 1892. The change to cooler and slightly drier air began Friday evening as thunderstorms associated with a cold front approached the area. Thunder occurred at the Observatory between 5 and 6 PM EST on Friday with a period of moderate rain. Another period of moderate rain fell early this morning with light rain occurring at the 7 AM EST observation time. The rainfall total since yesterday has been 0.30 inch. The sun returned by mid-morning and cumulus began building in the interior by late morning. These have grown to cumulus congestus by early afternoon, so showers and thunderstorms are possible later today. The air is beginning to dry out further with the dew point dropping to near 60 by 2 PM EST this afternoon. Today's observations: 7 A.M. Weather: Sky partly obscured in light rain and fog, broken stratus overcast nimbostratus, visibility increasing W-NW Temperature: 65F, Dew Point: 65F; Wind: NNW at 6 kts, Wind: Light Sea-level pressure: 29.84 inches Hg, rising Visibility: 3 miles, 6-hour min. temp: 65F 6-hour precip: N/A 24-hour precip: 0.28 inch BHO SA 1155 –X E20 BKN 30 OVC 3R-F 106/65/65/3406/984/ F2 VSBY INCR W-NW WND LGT/ 8/72/ 53017 60/// 70028 10068 20065 10 A.M. Weather: Scattered altocumulus, thin broken cirrus fibratus radiatus, few cumulus distant N-NW and ESE-SSW, few cumulus fractus vicinity of station, hazy Temperature: 73F, Dew Point: 64F; Wind: NW at 5 kts, Wind: Light and variable Sea-level pressure: 29.83 inches Hg, falling slightly Visibility: 50 miles, hazy 3-hour precip: 0.02 inch BHO SA 1455 100 SCT 250 –BKN 50 103/73/64/3005/983/ FEW CU DSNT W-NW AND ESE-SSW FEW CUFRA VCNTY STN HAZY WND LGT AND VRB/ 8/171 55003 6002/ 1 P.M. Weather: Scattered cumulus, thin broken cirrus, few moderate cumulus all quadrants, few cumulus congestus distant SW-NW, hazy Temperature: 81F, Dew Point: 64F; Wind: SSW at 3 kts, Wind: Light and variable Sea-level pressure: 29.84 inches Hg, rising slightly Visibility: 55 miles, hazy 6-hour max. 81F 6-hour min. 65F 6-hour precip: 0.02 inch BHO SA 1755 40 SCT 250 –BKN 55 104/81/64/2103/984/ FEW MOD CU ALQDS FEW CU CONGESTUS DSNT SW-NW HAZY WND LGT AND VRB/ 8/201 50001 6002/ 10081 20065 WEATHER SUMMARY FOR FRIDAY, JUNE 22 TEMPERATURE (DEGREES F) MAX.....93 NORMAL.....77 MIN.....69 NORMAL.....59 MEAN....81 NORMAL.....68 DEPARTURE FROM 30-YEAR NORMAL......................+13 TOTAL DEPARTURE FOR THE MONTH......................-43 [-2.2 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY...............0 DEPARTURE..........-2 TOTAL HEATING UNITS FOR THE MONTH..............95 DEPARTURE.........+29 TOTAL HEATING UNITS FOR THE SEASON...........4983 DEPARTURE.......-1380 TOTAL HEATING UNITS LAST SEASON TO DATE......6223 DIFFERENCE......-1240 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............40 W AT 9:54 A.M. AERO..................39 W AT 9:54 A.M. * ASOS..................40 W AT 9:54 A.M. DAVIS.................41 WSW AT 6:31 A.M. RMY 43 THE FASTEST MILE FOR YESTERDAY...........32 W AT 4:26 A.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............31 W AT 6:33 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........29 W AT 5:13 A.M. AVERAGE WIND SPEED AND DIRECTION.......11.2 WNW ASOS................10.2 DAVIS................9.5 W [276 deg.] * Last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.28 DEPARTURE...........+0.16 ASOS..............0.03 TOTAL PRECIPITATION FOR THE MONTH..........2.83 DEPARTURE...........-0.56 ASOS..............2.70 TOTAL PRECIPITATION FOR THE YEAR..........16.07 DEPARTURE...........-9.98 ASOS.............15.95 PRELIMINARY CLIMATE SUMMARY FOR JUNE 2012 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/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 6/1 67/53/60/-2/0.00/742/82 28 ENE AERO 28 MPH ENE RMY 29 6/2 63/52/58/-4/0.80/000/00 39 SE AERO 39 MPH SE RMY 40 6/3 62/50/56/-6/0.01/082/09 31 N AERO 28 MPH N RMY 29 6/4 50/47/49/-14/0.58/000/00 44 NNE AERO 43 MPH NNE RMY 43 6/5 54/47/51/-12/0.23/009/01 23 NNE AERO 18 MPH NNE RMY N/A 6/6 63/48/56/-7/0.01/310/34 16 ENE AERO 14 MPH ENE RMY 15 6/7 70/50/60/-4/0.27/328/36 31 NE AERO 31 MPH NE RMY 32 TSTM,1/8" HAIL 6/8 76/51/64/0/0.03/502/55 25 WSW AERO 25 MPH WNW RMY 26 TSTM 6/9 76/56/66/+2/T/822/90 25 WNW AERO 24 MPH WNW RMY 24 6/10 78/56/67/+2/0.00/868/95 21 E AERO 18 MPH E RMY 18 6/11 76/55/66/+1/0.00/521/57 23 S AERO 21 MPH S RMY 22 6/12 73/57/65/0/0.03/320/35 29 S AERO 29 MPH S RMY 30 6/13 63/60/62/-3/0.59/000/00 25 S AERO 23 MPH S RMY N/A 6/14 69/58/64/-2/0.00/624/68 32 NNE AERO 29 MPH NE RMY 31 6/15 68/54/61/-5/0.00/890/97 28 ENE AERO 24 MPH ENE RMY 25 6/16 64/51/58/-8/T/485/53 28 NE AERO 24 MPH NE RMY 27 6/17 67/50/59/-8/0.00/752/82 21 E AERO 17 MPH E RMY 19 6/18 68/50/59/-8/0.00/.../.. 21 S AERO 20 MPH S RMY 20 6/19 73/53/63/-4/0.00/.../.. 24 SW AERO 23 MPH SW RMY 24 6/20 93/62/78/+10/0.00/.../.. 22 SW AERO 22 MPH SW RMY N/A 6/21 94/74/84/+16/0.00/.../.. 22 NW AERO 22 MPH NW RMY 21 6/22 93/69/81/+13/..../.../.. 40 W AERO 39 MPH W RMY 43 TSTM 6/23 morning low temp: 65F; the normal low is now 59F DAILY RECORDS FOR JUNE 2012 6/4 - NEW DAILY RECORD LOW MAXIMUM TEMP OF 50F; surpasses the previous record of 51F in 1891. 6/21 - NEW DAILY RECORD HIGH MAXIMUM TEMP OF 94F; surpasses the previous record of 92F in 1949. 6/21 - DAILY RECORD HIGH MINUMUM TEMPERATURE OF 74F; ties the current record of 74F in 1923. 6/22 - DAILY RECORD HIGH MAXIMUM TEMP OF 93F; ties the current record of 93F in 1921. 6/22 - DAILY RECORD HIGH MINIMUM TEMP OF 59F; ties the current record of 69F in 1892. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JUNE 23 HIGH 93F IN 1888 LOW 45F IN 1885 PRECIP 0.70 INS IN 2006 PEAK GUST 63 MPH SE IN 1972 (AGNES) RECORDS FOR JUNE 24 HIGH 91F IN 1914,1976 LOW 40F IN 1932 PRECIP 2.80 INS IN 1929 PEAK GUST 46 MPH S IN 1985 TODAY'S REPORT PREPARED BY: Mike Iacono