BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, DECEMBER 12, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME SUNSHINE ALONG WITH NEW ARCTIC AIR MASS WINDS NOT VERY GUSTY THROUGH EARLY AFTERNOON Sunshine has been ineffective in bringing us much heating in the new Arctic air mass. Our temperature struggled up from a morning low of 16 degrees to an early afternoon high of close to 23F, well below normal for this date. At the same time dew point temperatures have fallen to the lower single numbers truly a sign of the newly arriving very cold air ass. Today's Observations: 7 A.M. Weather: Clear, stratocumulus/cumulus layer along and offshore NE-SE. cirrus distant SE-SSW, distant haze Temperature: 17F; Dew Point: 11F; Wind: NW at 9 kts. Sea-level pressure: 30.22 ins. Hg, rising then more slowly Visibility: 35 miles, distant haze Total snow on ground at 7 a.m. 1 inch 6-hr. min temp: 16F BHO SA 1155 CLR 35 234/17/11/3109/022/ CU/SC ALG/OFFSHR NE-SE CI DSNT SE-SSW LGT DSNT HZ/ 8/801 4/001 53017 10021 20016 10 A.M. Weather: Clear, few cumulus fractus forming vicinity station E-S, cumulus/stratocumulus along/offshore NE-SE, cirrus distant ESE-S-SW Temperature: 20; Dew Point: 4F; Wind: NW at 15G23 kts, Sea-level pressure: 30.25 ins. Hg, rising then falling Visibility: 70 miles, light distant haze BHO SA 1455 CLR 70 245/20/4/3115G23/025/ FEW CUFRA FMRG VC E-S CU/SC ALG/OFFSHR NE-SE CI DSNT ESE-S-SW WND 28V34/ 8/801 50011 1 P.M. Weather: Clear, cumulus fractus forming vicinity station mostly overhead-E-S, stratocumulus, cumulus along and offshore NE-SE, cirrus distant SE-SW Temperature: 22F; Dew Point: 2F; Wind: NW at 12 kts. Sea-level pressure: 30.19 ins. Hg, falling then falling more rapidly Visibility: 75 miles, light distant haze 6-hr max. temp. 23F 6-hr min. temp: 16F BHO SA 1755 CLR 75 223/22/2/3112/019/ CUFRA FRMG VC MOSTLY OVHD-E-S SCCU ALG/OFFSHR NE-SE CI DSNT SE-SW LGT DSNT HZ/ 8/801 58022 10023 20016 WEATHER SUMMARY FOR WEDNESDAY, DECEMBER 11, 2013 TEMPERATURE (DEGREES F) MAX.....28 NORMAL.....41 MIN.....19 NORMAL.....25 MEAN....24 NORMAL.....33 DEPARTURE FROM 30-YEAR NORMAL......................-9 TOTAL DEPARTURE FOR THE MONTH......................+0 [-0.2 DEGREE/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............41 DEPARTURE.........+9 TOTAL HEATING UNITS FOR THE MONTH.............333 DEPARTURE.........-0 TOTAL HEATING UNITS FOR THE SEASON...........1557 DEPARTURE........-37 TOTAL HEATING UNITS LAST SEASON TO DATE......1407 DIFFERENCE......+150 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..................27 SW AT 9:21 A.M. AERO.......................28 W AT 10:17 P.M. ASOS.......................27 W AT 9:22 A.M. DAVIS......................26 W AT 11:02 P.M. RMY 27 FASTEST MILE FOR YESTERDAY....................20 WSW AT 10:50 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE.................20 WSW AT 10:49 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE................19 W AT 4:22 A.M. AVERAGE WIND SPEED AND DIRECTION............14.0 ASOS.....................13.6 DAVIS....................12.4 WSW [240 degrees] * 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..........1.29 DEPARTURE.............-0.52 ASOS..............1.26 TOTAL PRECIPITATION FOR THE YEAR..........47.89 DEPARTURE..............-2.45 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.............2.7 DEPARTURE.............-0.9 TOTAL SNOWFALL FOR THE SEASON............2.9 DEPARTURE.............-3.3 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2013 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 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 12/1 45/30/38/+1/0.28/T/000/00 22 SSE AERO 23 MPH SSE RMY 23 12/2 38/34/36/0/T/0.0/000/00 15 NW AERO 15 MPH NW RMY 16 12/3 45/32/39/+3/0.00/0.0/284/51 18 NNW AERO 18 MPH NNW RMY 20 12/4 43/29/36/+1/0.00/0.0/389/70 21 WNW AERO 21 MPH WNW RMY 21 12/5 53/38/46/+11/0.02/0.0/000/00 36 S AERO 40 MPH S RMY 39 12/6 55/33/44/+9/0.38/T/000/00 25 SSW AERO 28 MPH SSW RMY N/A 12/7 40/26/33/-1/0.12/T/287/52 23 NW AERO 25 MPH NW RMY N/A 12/8 30/22/26/-8/T/T/039/07 25 NW AERO 27 MPH NW RMY N/A 12/9 41/25/33/-1/0.35/0.6/000/00 28 E AERO 28 MPH E RMY 24 12/10 33/21/27/-6/0.14/2.1/000/00 28 W AERO 28 MPH W RMY 28 12/11 28/19/24/-9/0.00/0.0/.../.. 27 SW AERO 28 MPH SW RMY 27 12/12 morning low temp: 16F; the normal low is now 25F DAILY RECORDS FOR DECEMBER 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 12 HIGH 67 IN 1979 LOW -3 IN 1988 PRECIP 3.94 INS. IN 1992 SNOWFALL 20.3 INS. IN 1960 PEAK GUST 75 MPH SSE IN 2008 RECORDS FOR DECEMBER 13 HIGH 60 IN 1984 LOW 0 IN 1893 PRECIP 1.45 INS. IN 1983 SNOWFALL 9.2 INS. IN 2007 PEAK GUST 81e WNW IN 1976 TODAY'S REPORT PREPARED BY: Robert Skilling