BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, NOVEMBER 16, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME COOL AND CALM WITH SURFACE HIGH PRESSURE BUILDING IN; RARE PARTIAL DOUBLE HALO OBSERVED TODAY Conditions today have been a bit on the cool side, but fairly calm. With a low of 31F and a high so far of 45F, temperatures a few degrees below normal. Winds continue from a northerly direction as a surface high pressure system builds in, but have been fairly calm. Wind gusts have only rarely reached 10-15 mph today. Skies have been mostly cloudy with a variety of mid and high level clouds. A rare and spectacular double halo was observed around the sun late this morning as sunlight was refracted through uniformly-aligned hexagonal ice crystals in a layer of cirrostratus clouds. The inner, 22 degree halo was nearly complete and quite apparent. The outer, 44 degree halo was only partially present and relatively faint. Today's observations: 7 A.M. Weather: Scattered stratocumulus, scattered altocumulus, broken altocumulus, broken altostratus, broken dense cirrus, broken cirrus, stratocumulus NNE-E-S, few altocumulus lenticularis distant W-N, higher cirrus layer partly thin, inversion present, smoke layer below inversion along horizon all quadrants, light distant haze, frost on grassy surfaces Temperature: 32F; Dew Point: 30F; Wind: N at 8 kts, Sea-level pressure: 30.29 ins. Hg, steady Visibility: 80 miles, light distant haze 6-hour min. temp: 31F BHO SA 1155 20 SCT 80 SCT E140 BKN 180 BKN 220 BKN 250 BKN 80 259/32/30/3508/029/ SC DSNT NNE-E-S FEW ACSL DSNT W-N HIER CI LYR PRTLY THN INVSN PRSNT K LYR BLO INVSN ALG HRZN ALQDS LGT DSNT HZ FROST GRASSY SFCS/ 8/572 54000 10033 20031 10 A.M. Weather: Scattered cumulus/stratocumulus, scattered altocumulus (2 levels), broken cirrostratus, broken dense cirrus, broken cirrus, few cumulus forming NNE-E-S, stratocumulus distant NNE-E-SSE, lower altocumulus/altocumulus lenticularis distant WSW-W, higher altocumulus/ altocumulus lenticularis E-S-WSW, higher cirrus layer partly thin, halo and partial double halo, dark smoke layer distant SW-NW-NE, distant haze Temperature: 40F; Dew Point: 32F; Wind: N at 4 kts, Wind: Light and variable Sea-level pressure: 30.34 ins. Hg, rising Visibility: 55 miles, distant haze BHO SA 1455 25 SCT 100 SCT 140 SCT E200 BKN 220 BKN 25 BKN 55 273/40/32/3604/034/ FEW CU FRMG NNE-E-S SC DSNT NNE-E-SSE LWR AC/ACSL DSNT WSW-W HIER AC/ACSL E-S-WSW HIER CI LYR PRTLY THN HALO AND PARTIAL DOUBLE HALO DRK K LYR DSNT SW-NW-NE DSNT HZ WND LGT AND VRB/ 8/547 52014 1 P.M. Weather: Scattered altocumulus, broken altocumulus, broken altostratus, broken cirrus, cumulus/stratocumulus layer distant NNE-E-S, few altocumulus lenticularis all quadrants, cirrus layer partly thin, thin smoke layer distant SW-NW-ENE, distant haze Temperature: 42F; Dew Point: 30F; Wind: N at 3 kts, Wind: Light and variable Sea-level pressure: 30.31 ins. Hg, falling Visibility: 65 miles, distant haze 6-hour max. temp: 45F BHO SA 1755 120 SCT E140 BKN 180 BKN 250 BKN 65 263/42/30/3503/031/ CU/SC LYR DSNT NNE-E-S FEW ACSL ALQDS CI LYR PRTLY THN THN K LYR DSNT SW-NW-ENE DSNT HZ WND LGT AND VRB/ 8/571 55010 10045 20032 WEATHER SUMMARY FOR THURSDAY, NOVEMBER 15 TEMPERATURE (DEGREES F) MAX.....39 NORMAL.....50 MIN.....32 NORMAL.....34 MEAN....36 NORMAL.....42 DEPARTURE FROM 30-YEAR NORMAL.....................-6 TOTAL DEPARTURE FOR THE MONTH....................-19 [-1.5 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............29 DEPARTURE........+6 TOTAL HEATING UNITS FOR THE MONTH...........331 DEPARTURE.......+19 TOTAL HEATING UNITS FOR THE SEASON..........739 DEPARTURE......-136 TOTAL HEATING UNITS LAST SEASON TO DATE.....649 DIFFERENCE......+90 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............23 N AT 11:32 A.M. * AERO...................21 N AT 11:28 A.M. ASOS...................23 N AT 11:28 A.M. DAVIS..................23 N AT 11:26 A.M. RMY 25 THE FASTEST MILE FOR YESTERDAY............14 N AT 11:48 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............16 N AT 11:28 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............15 N AT 11:28 A.M. AVERAGE WIND SPEED AND DIRECTION.........9.3 NNW ASOS..................9.2 DAVIS.................8.5 N [002 deg] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE..........-0.16 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.49 DEPARTURE..........-0.87 ASOS..............1.52 TOTAL PRECIPITATION FOR THE YEAR..........34.69 DEPARTURE.........-11.44 ASOS.............34.70 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE..........-0.1 TOTAL SNOWFALL FOR THE MONTH...............4.0 DEPARTURE..........+3.4 TOTAL SNOWFALL FOR THE SEASON..............4.0 DEPARTURE..........+3.1 PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER 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 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 11/1 56/42/49/+3/0.00/371/60 28 SW AERO 28 MPH SW RMY 27 11/2 51/41/46/0/0.02/000/00 24 WNW AERO 22 MPH WNW RMY 22 11/3 52/37/45/-1/0.00/319/52 29 NW AERO N/A RMY 28 11/4 52/34/43/-2/0.00/570/96 27 NW AERO 25 MPH NW RMY 26 11/5 45/28/37/-8/0.00/292/48 25 NW AERO 25 MPH NW RMY 25 11/6 40/25/33/-12/0.00/600/99 22 ENE AERO 20 MPH ENE RMY N/A 11/7 42/29/36/-9/0.78/3.5/000/00 48 NNE AERO 52 MPH NNE RMY 51 11/8 36/29/33/-11/0.26/0.5/000/00 43 N AERO 50 MPH N RMY 44 11/9 51/34/43/-1/0.00/0.0/569/95 33 NW AERO 35 MPH NW RMY 32 11/10 53/36/45/+1/0.00/0.0/561/94 25 W AERO 23 MPH W RMY 23 11/11 62/40/51/+8/0.00/0.0/357/60 28 SSW AERO 27 MPH SSW RMY 28 11/12 66/50/58/+15/0.00/0.0/385/65 33 SSW AERO 33 MPH S RMY N/A 11/13 63/37/50/+7/0.43/0.0/000/00 45 S AERO 45 MPH S RMY N/A 11/14 44/33/39/-3/0.00/0.0/559/95 27 NNE AERO 23 MPH N RMY 24 11/15 39/32/36/-6/0.00/0.0/.../.. 23 N AERO 21 MPH N RMY 25 11/16 morning low temp: 31F; the normal low is now 34F DAILY RECORDS FOR NOVEMBER 2012 11/7 - NEW DAILY RECORD MAXIMUM SNOWFALL OF 3.5 INCHES; surpasses the previous record of 1.0 inch in 1967 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR NOVEMBER 16 HIGH 73 IN 1927 LOW 8 IN 1933 PRECIP 2.25 INCHES IN 1981 SNOWFALL 2.0 IN 1913 PEAK GUST 78 S IN 1989 RECORDS FOR NOVEMBER 17 HIGH 74 IN 1928 LOW 10 IN 1924 PRECIP 1.92 INCHES IN 1920 SNOWFALL 1.0 INS IN 1980 PEAK GUST 61 SSE IN 2006 TODAY'S REPORT PREPARED BY: Sean Fankhauser