BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, MAY 15, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME CLOUDY AND WARM TODAY; MAY NOW AVERAGING SLIGHTLY WARMER THAN NORMAL Sky conditions have been mostly cloudy all day, with only a few moments of sunshine this morning. The sky has become overcast this afternoon, with a very brief, light sprinkle observed just after the 2 PM EDT observation. With a low of 57F this morning and a high shortly after noon EDT of 72F, temperatures are running several degrees above average. Dew point temperatures have held fairly steady in the mid 50s. Visibility has also held steady at a hazy 45 miles. Winds continue out of the S, transporting a warm and moist air mass into the region. Winds have gusted at times in the 25-35 mph range. With the warmth of the past few days, the negative temperature departure that we had seen for much of the month of May has now been wiped out. Today's warmth will put the month slightly above normal. A rain shower Monday afternoon between 3 and 5 p.m. EDT provided 0.04 inch of precipitation. Every little bit is welcomed and needed to address our 2012 rainfall deficit which stands at just over 8 inches. Today's observations: 7 A.M. Weather: Scattered altocumulus, broken altocumulus, broken altostratus, broken dense cirrus, broken cirrus, altocumulus chaotic, altocumulus lenticularis all quadrants, few altocumulus castellanus distant NNE-E, altostratus WSW-NW-NNE, patches of virga NNE-SE and SSW, smoke layer along horizon all quadrants, distant haze Temperature: 61F, Dew Point: 55F; Wind: S at 13G18 kts, Sea-level pressure: 30.17 inches Hg, rising then steady Visibility: 45 miles, distant haze 24-hour rainfall: 0.04 in. 6-hour min. temp: 57F BHO SA 1155 80 SCT E100 BKN 160 BKN 220 BKN 250 BKN 45 216/61/55/1713G18/017/ AC CHAOTIC ACSL ALQDS FEW ACC DSNT NNE-E AS WSW-NW-NNE PTCHS VIRGA NNE-SE AND SSW K LYR ALG HRZN ALQDS DSNT HZ/ 8/092 51003 MANUAL 70004 ASOS 70004 10061 20057 10 A.M. Weather: Scattered cumulus, broken stratocumulus (2 levels), broken altostratus, few moderate cumulus ESE-S-WSW, altocumlus chaotic, altocumulus lenticularis all quadrants, partial halo, distant haze Temperature: 68F, Dew Point: 55F; Wind: S at 16G22 kts, Wind: Direction variable SE-SSW Sea-level pressure: 30.15 inches Hg, falling Visibility: 45 miles, distant haze BHO SA 1455 30 SCT E100 BKN 120 BKN 160 BKN 45 210/68/55/1716G22/015/ FEW MDT CU ESE-S-WSW AC CHAOTIC ACSL ALQDS PARTIAL HALO DSNT HZ WND 14V21/ 8/290 58006 1 P.M. Weather: Scattered cumulus, broken altocumulus (2 levels), overcast altostratus, moderate cumulus all quadrants, altocumulus lenticularis all quadrants, few small breaks in overcast distant NE and distant SSE, distant haze, rain shower distant SW-W moving NE Temperature: 68F, Dew Point: 53F; Wind: S at 17G23 kts, Wind: Direction variable SE-SW Sea-level pressure: 30.13 inches Hg, falling Visibility: 45 miles, distant haze 6-hour max. temp: 72F BHO SA 1755 35 SCT E60 BKN 100 BKN 140 OVC 45 202/68/53/1817G23/013/ MDT CU ALQDS ACSL ALQDS FEW SML BINOVC DSNT NE AND DSNT SSE DSNT HZ SHRA DSNT SW-W MOVG NE WND 14V22/ 8/270 56008 10072 20061 WEATHER SUMMARY FOR MONDAY, MAY 14 TEMPERATURE (DEGREES F) MAX.....71 NORMAL.....66 MIN.....52 NORMAL.....47 MEAN....62 NORMAL.....57 DEPARTURE FROM 30-YEAR NORMAL........................+5 TOTAL DEPARTURE FOR THE MONTH........................+1 [-0.1 DEGREE/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY...............3 DEPARTURE..........-6 TOTAL HEATING UNITS FOR THE MONTH.............148 DEPARTURE..........-8 TOTAL HEATING UNITS FOR THE SEASON...........4862 DEPARTURE.......-1320 TOTAL HEATING UNITS LAST SEASON TO DATE......6042 DIFFERENCE......-1180 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............23 S AT 11:14 P.M. AERO..................24 S AT 11:03 P.M. ASOS..................23 S AT 11:41 P.M. DAVIS.................23 S AT 11:41 P.M. RMY 23 THE FASTEST MILE FOR YESTERDAY...........17 S AT 11:49 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............17 S AT 11:49 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........N/A AVERAGE WIND SPEED AND DIRECTION........6.9 S ASOS.................6.1 DAVIS................6.3 SSE [162 deg.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.04 DEPARTURE..........-0.08 ASOS..............0.04 TOTAL PRECIPITATION FOR THE MONTH..........2.40 DEPARTURE..........+0.69 ASOS..............2.33 TOTAL PRECIPITATION FOR THE YEAR..........12.01 DEPARTURE..........-8.25 ASOS.............12.06 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 77/46/62/+6/0.00/0.0/.../.. 30 W AERO 30 MPH W RMY 29 5/13 82/57/70/+14/0.00/0.0/.../.. 27 S AERO 29 MPH S RMY 29 5/14 71/52/62/+5/0.05/0.0/.../.. 23 S AERO 24 MPH S RMY 23 5/15 morning low temp: 57F; the normal low is now 48F 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 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 RECORDS FOR MAY 16 HIGH 90F IN 1951 LOW 30F IN 1936 PRECIP 2.63 INCHES IN 1954 PEAK GUST 56e MPH NW IN 1952 TODAY'S REPORT PREPARED BY: Sean Fankhauser