BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, DECEMBER 5, 2011 ALL TIMES ARE IN EASTERN STANDARD TIME TEMPERATURE REACHES 60F BEFORE 2 P.M. UNSEASONABLY MILD TEMPERATURES AVERAGE FAR ABOVE NORMAL AS DECEMBER GETS OFF TO A WARM START The temperature was reaching 60F early this afternoon after an unseasonably warm start with a low of 44F some 17 degrees above normal. Dew point temperatures were on the rise overnight last night reaching near 50F this morning. Considerable fog and low clouds developed and heavy dew covered all surfaces this morning. By early afternoon our visibility had increased to 20 to 45 miles with some distant haze after briefly dropping to well under one mile in fog early this morning. A sharp temperature inversion existed before dawn today with Norwood Airport reporting a low of 33 degrees while we were in the mid-40's here at the summit. Today's observations: 7 A.M. Weather: Scattered dense cirrus, thin broken cirrus, few stratus fractus E-S and patches stratus fractus drifting below summit E, altocumulus lenticularis and altocumulus of a chaotic sky, patches of shallow dense valley fog 2 miles W-WNW, heavy dew all surfaces Temperature: 48F, Dew point: 48F; Wind: SSW at 13 kts Sea-level pressure: 30.36 inches Hg, rising Visibility: 10 miles, thin fog, except 6 miles east thru south, thin fog below summit/inversion all quadrants 6-hour min. temp: 44F BHO SA 1155 220 SCT 250 –SCT 300 –BKN 10 282/48/48/2113/036/ FEW STFRA E-S PTCHS STFRA DRFTG BLO SMT E THN FG BLO SMT/INVSN ALQDS ESTMTD TOP OF INVSN 6 HND OVR CTY N PTCHS DNS SHLW VLY GF 2 W-WNW ACSL/AC CHAOTIC ALQDS PTCH DNS CI E VSBY E-S 6 DEW ALL SFCS / 8/692 51005 10048 20044 10 A.M. Weather: Scattered altocumulus, broken altocumulus, broken dense cirrus, overcast cirrus, overcast partly thin, few stratus fractus all quadrants. altocumulus of a chaotic sky and dense cirrus all quads Temperature: 54F, Dew Point: 50F; Wind: SW at 9 kts, Sea-level pressure: 30.37 inches Hg, falling slightly Visibility: 15 miles, thin fog, hazy BHO SA 1455 130 SCT E150 BKN 180 BKN 220 BKN 250 OVC 15 284/54/50/2209/037/ FEW STFRA ALQDS FEW ACSL AC CHAOTIC DNS CI OVC PTLY THN F HAZY/ 8/692 50002 1 P.M. Weather: Broken altocumulus (chaotic) 2 layers, overcast dense ci, ci, small breaks in overcast and thin spots in overcast mostly W-N, few cumulus E-SW Temperature: 59F, Dew Point: 48F; Wind: SW at 13 kts, Sea-level pressure: 30.32 inches Hg, falling Visibility: 35 miles, 45 WNW, 20 NE, distant haze BHO SA 1755 130 SCT E150 BKN 180 BKN 220 OVC 35 268/59/48/2313/032/ FEW CUFRA/CU E-SW AC CHAOTIC DNS CI ALQDS SML BINOVC W-N THN SPTS IOVC VSBY WNW 45 NE 20 DSNT HZ/ 8/192 56016 10059 20048 WEATHER SUMMARY FOR SUNDAY, DECEMBER 4 TEMPERATURE (DEGREES F) MAX.....51 NORMAL.....42 MIN.....34 NORMAL.....28 MEAN....43 NORMAL.....35 DEPARTURE FROM 30-YEAR NORMAL......................+8 TOTAL DEPARTURE FOR THE MONTH.....................+18 [+4.3 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............22 DEPARTURE.........-8 TOTAL HEATING UNITS FOR THE MONTH............100 DEPARTURE........-18 TOTAL HEATING UNITS FOR THE SEASON..........1007 DEPARTURE.......-400 TOTAL HEATING UNITS LAST SEASON TO DATE.....1264 DIFFERENCE......-257 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............28 SSW AT 11:08 P.M. * AERO..................30 SSW AT 10:54 P.M. ASOS..................29 SSW AT 10:54 P.M. DAVIS.................29 S AT 10:54 P.M. RMY 29 MPH THE FASTEST MILE FOR YESTERDAY...........23 SSW AT 10:58 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............22 SSW AT 11:03 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 SSW AT 10:58 P.M. AVERAGE WIND SPEED AND DIRECTION.......14.7 S ASOS................14.0 DAVIS...............13.7 S [190 deg] * Last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE..........-0.15 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.00 DEPARTURE..........-0.60 ASOS..............0.00 TOTAL PRECIPITATION FOR THE YEAR..........58.69 DEPARTURE.........+11.43 ASOS..............59.09** **ASOS data is in error due to system failure on 1/12-13/11 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.........-0.2 TOTAL SNOWFALL FOR THE MONTH................0.0 DEPARTURE.........-0.8 TOTAL SNOWFALL FOR THE SEASON...............8.5 DEPARTURE.........+4.8 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2011 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: 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 12/1 46/33/40/+4/0.00/0.0/.../.. 29 NW AERO 29 MPH NW RMY 27 MPH 12/2 49/31/40/+4/0.00/0.0/.../.. 25 NW AERO 28 MPH NW RMY 28 MPH 12/3 43/30/37/+2/0.00/0.0/.../.. 21 NW AERO 22 MPH NW RMY N/A 12/4 51/34/43/+8/0.00/0.0/.../.. 28 SSW AERO 30 MPH S RMY 29 MPH 12/5 our morning low temp: 44F; the normal low is now 27F DAILY RECORDS FOR DECEMBER 2011 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 5 HIGH 65 IN 2001 LOW -1 IN 1926 PRECIP 2.86 INS. IN 1993 SNOWFALL 7.0 INS. IN 1926, 1981 PEAK GUST 67 MPH WNW IN 1961, S IN 1973 RECORDS FOR DECEMBER 6 HIGH 70 IN 2001 LOW 5 IN 1901,1935 PRECIP 2.78 INS. IN 2003 SNOWFALL 17.0 INS. IN 2003 PEAK GUST 74 MPH NW IN 1981 TODAY'S REPORT PREPARED BY: Robert Skilling/Patrick Peters