BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, MARCH 15, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME CHILLY, FAIRLY CALM DAY; SOME SUNSHINE FOR A CHANGE The morning low of 17F was the coolest temperature reading on the summit in nearly a month (11F on Feb. 18th). The high temperature, as was the case yesterday, has struggled to reach the mid 30s. And, like yesterday, the average daily temperature will likely be several degrees below the 30-year average for the date. The warmth of the first half of March pushed the average monthly temperature about 3 degrees above normal. That departure will likely be whittled away over the next couple of weeks with more cool temperatures in the forecast. Sunshine has been a rarity this month. In contrast, today some intermittent and very welcomed sunshine has been observed. However, clouds are increasing this afternoon ahead of a weak disturbance that will slide south of the region early this weekend. With a dry air mass (dew point in the single digits) in place, visibility today has been excellent, reaching 75-80 miles much of the day. Today's observations: 7 A.M. Weather: Scattered altocumulus, scattered thin cirrus (2 levels), cumulus/ stratocumulus layer along/offshore distant NE-S, altocumulus/altocumulus lenticularis distant SSW-N, thin smoke/haze distant N-SE, light distant haze Temperature: 19F; Dew Point: 8F; Wind: WNW at 10 kts. Sea-level pressure: 29.86 ins. Hg, rising Visibility: 70 miles, light distant haze 6-hr min. temp: 17F Snow depth: Trace BHO SA 1155 160 SCT 250 –SCT 300 –BKN 70 113/19/8/2910/986/ CU/SC LYR ALG/OFFSHR DSNT NE-S AC/ACSL DSNT SSW-N THN K/HZ DSNT N-SE LGT DSNT HZ/ 8/541 52010 10021 20017 10 A.M. Weather: Scattered altocumulus, scattered altostratus, broken cirrostratus, broken cirrus, few cumulus along/offshore distant ENE-SE, altocumulus lenticularis S-W-N, partial halo, light distant haze Temperature: 27F; Dew Point: 10F; Wind: WNW at 11G19 kts, Wind: Direction variable W-NNW Sea-level pressure: 29.84 ins. Hg, falling slightly Visibility: 80 miles, light distant haze BHO SA 1455 120 SCT 180 SCT E200 BKN 250 BKN 80 106/27/10/2911G19/984/ FEW CU ALG/OFFSHR DSNT ENE-SE ACSL S-W-N PARTIAL HALO LGT DSNT HZ WND 26V33/ 8/177 58007 1 P.M. Weather: Scattered altocumulus, scattered altostratus, broken cirrostratus, broken cirrus, few altocumulus lenticularis distant W-N, light distant haze, virga SW Temperature: 35F; Dew Point: 6F; Wind: WSW at 14G21 kts, Wind: Direction variable S-W Sea-level pressure: 29.75 ins. Hg, falling Visibility: 75 miles, light distant haze 6-hour max. temp: 36F BHO SA 1755 100 SCT 180 SCT 200 BKN 250 BKN 75 076/35/6/2514G21/975/ FEW ACSL DSNT W-N LGT DSNT HZ VIRGA SW WND 19V28/ 8/077 58030 10036 20019 WEATHER SUMMARY FOR THURSDAY, MARCH 14 TEMPERATURE (DEGREES F) MAX.....34 NORMAL.....44 MIN.....20 NORMAL.....26 MEAN....27 NORMAL.....35 DEPARTURE FROM 30-YEAR NORMAL.......................-8 TOTAL DEPARTURE FOR THE MONTH......................+44 [+2.9 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............38 DEPARTURE............+8 TOTAL HEATING UNITS FOR THE MONTH...........406 DEPARTURE...........-45 TOTAL HEATING UNITS FOR THE SEASON.........4526 DEPARTURE..........-493 TOTAL HEATING UNITS LAST SEASON TO DATE....4002 DIFFERENCE.........+524 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............37 W AT 5:23 P.M. AERO....................37 NW AT 8:08 P.M. ASOS....................37 WNW AT 5:24 P.M. DAVIS...................38 WNW AT 7:57 P.M. RMY: 38 THE FASTEST MILE FOR YESTERDAY.............27 NW AT 8:09 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE..............25 NW AT 8:10 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............26 WNW AT 8:10 P.M. AVERAGE WIND SPEED AND DIRECTION.........15.9 WNW ASOS..................15.0 DAVIS.................13.7 WNW [288 deg] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE...........-0.17 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........3.96 DEPARTURE...........+1.55 ASOS..............4.20 TOTAL PRECIPITATION FOR THE YEAR..........12.35 DEPARTURE...........+1.52 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............-0.4 TOTAL SNOWFALL FOR THE MONTH..............30.0 DEPARTURE...........+23.1 TOTAL SNOWFALL FOR THE SEASON.............91.2 DEPARTURE...........+37.3 PRELIMINARY CLIMATE SUMMARY FOR MARCH 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 3/1 39/33/36/+5/0.00/0.0/047/07 25 NNW AERO 24 MPH NNW RMY 28 3/2 42/30/36/+5/0.00/0.0/400/59 18 NW AERO 16 MPH NW RMY 21 3/3 42/30/36/+4/0.01/0.2/034/05 17 WNW AERO 15 MPH WNW RMY N/A 3/4 39/26/33/+1/T/T/328/48 32 NW AERO 33 MPH WNW RMY 37 3/5 43/30/37/+5/0/0/123/18 27 WNW AERO 24 MPH WNW RMY N/A 3/6 37/33/35/+3/.../.../000/00 * 47 NE AERO 46 MPH NE RMY 51 3/7 34/29/32/-1/.../.../000/00 * 45 NE AERO 45 MPH NE RMY 47 3/8 37/28/33/0/.../.../000/00 * 41 NNE AERO 39 MPH NNW RMY 45 3/9 40/29/35/+2/0.00/0.0/677/97 29 N AERO 23 MPH N RMY 28 3/10 40/27/34/+1/0.00/0.0/372/53 21 S AERO 17 MPH S RMY N/A 3/11 50/32/41/+7/0.00/0.0/099/14 27 S AERO 25 MPH S RMY N/A 3/12 52/39/46/+12/0.51/0.0/000/00 45 S AERO 46 MPH S RMY 47 3/13 50/33/42/+8/T/0.0/674/95 32 WNW AERO 32 MPH WNW RMY 34 3/14 34/20/27/-8/0.00/0.0/.../.. 37 W AERO 37 MPH NW RMY 38 3/15 the morning low temp: 17F; the normal low is now 26F * Precipitation and snowfall for calendar days March 6-8 are under review. The records under review are as follows: (inches) March 6 0.19 precip // 0.3 snowfall March 7 1.36 precip // 11.5 snowfall March 8 1.89 precip // 18.0 snowfall DAILY RECORDS FOR MARCH 2013 None so far. Calendar day precipitation and snowfall amounts for 3/6-8 are under review. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MARCH 15 HIGH 80 IN 1990 LOW 6 IN 1993 PRE 2.86 INS. IN 2010 SNOW 12.0 INS. 1967 WIND 73e MPH ESE IN 1940 RECORDS FOR MARCH 16 HIGH 73 IN 1990 LOW 8 IN 1932 PRE 1.95 INS. IN 1900 SNOW 10.0 INS. IN 1896 WIND 79 MPH NE IN 1956 TODAY'S REPORT PREPARED BY: Sean Fankhauser