BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, MAY 14, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME CHILLY DAY; FEW LATE MORNING SPRINKLES The morning low began at 38F, only 5 degree shy of the record of 33F set way back in 1895. Temperatures are struggling to reach the upper 50s this afternoon. Today's average temperature will likely end up nearly 10 degrees below the 30-year normal. The wind direction has been gradually backing from a NNW direction this morning to a W direction this afternoon, but a cool air mass continues to be advected into the region. Plenty of clouds have developed this afternoon, only allowing for occasional, brief glimpses of sunshine. A few rain showers/virga have been observed today extending down in veils from the bases of some of the more well-developed cumulus. A brief, very light rain shower late this morning lasted only a few short minutes and provided only a trace of precipitation. Today's observations: 7 A.M. Weather: Scattered cumulus, scattered altocumulus cumulogenitus, scattered altocumulus, cumulus congestus NE-S, higher altocumulus NNE-SSE, thin smoke layer along horizon NNW-NNE, light distant haze, rain shower/virga SE and S and distant NNE-ESE and distant SW and distant NNW-N moving SE Temperature: 44F; Dew Point: 32F; Wind: NNW at 7 kts, Wind: Direction variable WNW-N Sea-level pressure: 30.06 ins. Hg, rising then more slowly Visibility: 65 miles, light distant haze 6-hour min. temp: 38F BHO SA 1155 50 SCT 70 SCT 100 SCT 65 178/44/32/3307/006/ CU CONGESTUS NE-S HIER AC NNE-SSE THN K LYR ALG HRZN NNW-NNE LGT DSNT HZ SHRA/VIRGA SE AND S AND DSNT NNE-ESE AND DSNT SW AND DSNT NNW-N MOVG SE WND 30V36/ 8/360 51014 10045 20038 10 A.M. Weather: Scattered cumulus, broken altocumulus cumulogenitus, broken altocumulus, moderate cumulus all quadrants, mostly clear sky distant ENE-N, rain shower/virga S-SSW and WSW moving SSE, light distant haze Temperature: 54F; Dew Point: 29F; Wind: NW at 9G18 kts, Wind: Direction variable W-N Sea-level pressure: 30.04 ins. Hg, falling then rising Visibility: 65 miles, light distant haze BHO SA 1455 50 SCT E80 BKN 100 BKN 65 173/54/29/3209G18/004/ MDT CU ALQDS MSTLY CLR SKY DSNT ENE-E SHRA/VIRGA S-SSW AND WSW MOVG SSE LGT DSNT HZ WND 26V36/ 8/260 55005 1 P.M. Weather: Broken cumulus, broken stratocumulus, broken altocumulus cumulogenitus, moderate cumulus all quadrants, rain shower/virga SE-SW and distant WSW-WNW moving SSE, light distant haze Temperature: 53F; Dew Point: 30F; Wind: W at 9G16 kts, Wind: Direction variable WSW-NW Sea-level pressure: 30.02 ins. Hg, falling slightly Visibility: 65 miles, light distant haze 6-hour precip: Trace 6-hour max temp: 58F BHO SA 1755 E65 BKN 70 BKN 80 BKN 65 167/53/30/2809G16/002/ MDT CU ALQDS SHRA/VIRGA SE-SW AND DSNT WSW-WNW MOVG SSE LGT DSNT HZ WND 25V31/ 8/260 58006 MANUAL 6000/ 10058 20044 WEATHER SUMMARY FOR MONDAY, MAY 13, 2013 TEMPERATURE (DEGREES F) MAX.....60 NORMAL.....66 MIN.....41 NORMAL.....47 MEAN....51 NORMAL.....56 DEPARTURE FROM 30-YEAR NORMAL....................-5 TOTAL DEPARTURE FOR THE MONTH...................+30 [+2.1 DEGREE/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............14 DEPARTURE..........+5 TOTAL HEATING UNITS FOR THE MONTH...........107 DEPARTURE.........-35 TOTAL HEATING UNITS FOR THE SEASON.........5629 DEPARTURE........-548 TOTAL HEATING UNITS LAST SEASON TO DATE....4859 DIFFERENCE.......+770 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............25 WSW AT 7:58 A.M. AERO....................28 WSW AT 7:57 A.M. ASOS....................29 WSW AT 7:58 A.M. DAVIS...................29 WSW AT 7:57 A.M. RMY: 30 THE FASTEST MILE FOR YESTERDAY.............18 NW AT 6:22 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE..............20 W AT 1:53 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............19 WSW AT 7:31 A.M. AVERAGE WIND SPEED AND DIRECTION.........12.0 WSW ASOS..................11.5 DAVIS.................10.7 W [273 deg] *Last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE............-0.12 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.94 DEPARTURE...........-0.65 ASOS..............0.89 TOTAL PRECIPITATION FOR THE YEAR..........17.32 DEPARTURE...........-2.82 ASOS..............N/A* *ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals 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.............0.0 TOTAL SNOWFALL FOR THE SEASON.............99.0 DEPARTURE...........+36.3 PRELIMINARY CLIMATE SUMMARY FOR MAY 2013 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust 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 67/45/56/+3/0.00/845/100 18 E AERO 16 MPH E RMY 17 5/2 75/43/59/+6/T/669/79 29 NE AERO 26 MPH NE RMY 29 5/3 54/42/48/-5/0.00/706/83 24 NE AERO 25 MPH NE RMY 28 5/4 55/40/48/-6/0.00/843/99 21 NE AERO 23 MPH NE RMY 23 5/5 58/37/48/-6/0.00/752/88 17 ENE AERO 17 MPH ENE RMY 20 5/6 66/40/53/-1/0.00/600/70 17 S AERO 18 MPH S RMY 20 5/7 77/50/64/+9/0.00/807/94 21 S AERO 23 MPH S RMY 25 5/8 71/55/63/+8/0.42/112/13 31 SSE AERO 35 MPH SSE RMY 35 TSTM 5/9 66/56/61/+6/0.41/078/09 16 NE AERO 16 MPH NE RMY 18 TSTM 5/10 79/54/66/+11/T/333/63 18 S AERO 21 MPH S RMY N/A 5/11 70/56/63/+7/0.06/.../.. 43 SSW AERO 44 MPH SSW RMY 46 5/12 71/47/59/+3/0.05/339/39 30 W AERO 32 MPH W RMY 32 5/13 60/41/51/-5/0.00/.../.. 25 WSW AERO 28 MPH WSW RMY 30 5/14 morning low temp: 38F; the normal low is now 47F DAILY RECORDS FOR MAY 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 14 HIGH 85F IN 1961 LOW 33F IN 1895 PRECIP 1.93 INCHES IN 2006 PEAK GUST 53 MPH S IN 2009 RECORDS FOR MAY 15 HIGH 93F IN 1900 LOW 36F IN 1947,1985 PRECIP 1.63 INCHES IN 1978 PEAK GUST 53e MPH NE IN 1978, W 2002 TODAY'S REPORT PREPARED BY: Sean Fankhauser