BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, FEBRUARY 15, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME DENSE FOG QUICKLY DISSIPATES GIVING WAY TO SUNNY AND WARM DAY Southerly winds transported a warmer air mass over the snow pack-chilled and moistened near surface air this morning, resulting in the formation of dense fog. Visibility was reduced to 1/16th of a mile before the fog gradually dissipated an hour or two after sunrise. There have been little in the way of clouds since the fog dissipated. Mostly sunny conditions have prevailed, and temperatures have responded accordingly, reaching the upper 40s this afternoon. Temperatures today are running close to 10 degrees above normal. The negative temperature departure for the month of February has been erased. The month is now averaging above normal. Today's observations: 7 A.M. Weather: Sky mostly obscured by dense fog, stratus drifting over summit Temperature: 32F; Dew Point: 32F; Wind: S at 13 kts. Sea-level pressure: 30.00 ins. Hg, steady then rising slightly Visibility: 1/16 mile, dense fog Snow depth: 10 inches 6-hour min. temp: 29F BHO SA 1155 –X 1/16F 160/32/32/1913/000/ F9 STRA DRFTNG OVR SMT/ 8//// 4/010 53003 10032 20029 10 A.M. Weather: Scattered dense cirrus, scattered thin cirrus, patches of dense cirrus WSW-NW-NE, hazy Temperature: 40F; Dew Point: 30F; Wind: SSW at 15G20 kts, Wind: Direction variable SSE-SW Sea-level pressure: 30.02 ins. Hg, rising slightly Visibility: 15 miles, hazy BHO SA 1455 220 SCT 250 –SCT 15 165/40/30/2015G20/002/ PTHCS DNS CI WSW-NW-NE HAZY WND 16V23/ 8/002 51005 1 P.M. Weather: Clear, few small cumulus forming SE-SW-NNW, few thin cirrus distant E, hazy, thin smoke/haze layer distant all quadrants Temperature: 47F; Dew Point: 33F; Wind: S at 14G22 kts, Wind: Direction variable SSE-SW Sea-level pressure: 29.96 ins. Hg, falling Visibility: 25 miles, hazy 6-hr max temp: 48F BHO SA 1755 CLR 25 147/47/33/1914G22/996/ FEW SML CU FRMG SE-SW-NNW FEW THN CI DSNT E HAZY THN K/HZ LYR DSNT ALQDS WND 15V22/ 8/101 58018 10048 20032 WEATHER SUMMARY FOR THURSDAY, FEBRUARY 14 TEMPERATURE (DEGREES F) MAX.....43 NORMAL.....37 MIN.....29 NORMAL.....19 MEAN....36 NORMAL.....28 DEPARTURE FROM 30-YEAR NORMAL.....................+8 TOTAL DEPARTURE FOR THE MONTH.....................+2 [-0.1 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............29 DEPARTURE...........-8 TOTAL HEATING UNITS FOR THE MONTH...........534 DEPARTURE...........-3 TOTAL HEATING UNITS FOR THE SEASON.........3660 DEPARTURE.........-408 TOTAL HEATING UNITS LAST SEASON TO DATE....3232 DIFFERENCE........+428 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............21 NNW AT 10:43 A.M. AERO....................16 NNW AT 10:43 A.M. ASOS....................20 S AT 6:49 P.M. DAVIS...................19 NW AT 10:43 A.M. RMY N/A THE FASTEST MILE FOR YESTERDAY.............13 SW AT 11:16 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE..............15 SSW AT 7:45 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............15 S AT 6:50 P.M. AVERAGE WIND SPEED AND DIRECTION..........8.7 NNW ASOS...................8.9 DAVIS..................8.2 W [279 deg] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE...........-0.14 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........3.12 DEPARTURE...........+1.20 ASOS..............N/A* TOTAL PRECIPITATION FOR THE YEAR...........4.54 DEPARTURE...........-1.73 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............-0.5 TOTAL SNOWFALL FOR THE MONTH..............28.9 DEPARTURE...........+22.0 TOTAL SNOWFALL FOR THE SEASON.............50.4 DEPARTURE...........+10.4 PRELIMINARY CLIMATE SUMMARY FOR FEBRUARY 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 2/1 32/19/26/0/T/T/325/54 39 WSW AERO 38 MPH W RMY 42 2/2 30/15/23/-3/0/0/452/75 28 SSW AERO 23 MPH SSW RMY 28 2/3 26/19/23/-3/0.08/1.2/000/00 22 W AERO 21 MPH WSW RMY N/A 2/4 29/17/23/-3/T/T/547/90 44 W AERO 46 MPH W RMY N/A 2/5 25/18/22/-4/0.04/0.8/000/00 21 W AERO 16 MPH W RMY N/A 2/6 37/22/30/+4/0.01/0.2/521/85 35 W AERO 33 MPH W RMY 35 2/7 29/16/23/-4/0.00/0.0/306/52 24 NW AERO 21 MPH NW RMY 24 2/8 31/18/25/-2/1.86/16.1/000/00 63 NE AERO 61 MPH NE RMY 66 2/9 20/12/16/-11/0.98/10.5/000/00 51 NNW AERO 52 MPH N RMY 51 2/10 37/9/23/-4/0.00/0.0/623/100 29 NW AERO 27 MPH NW RMY N/A 2/11 44/23/34/+7/0.15/T/000/00 33 S AERO 35 MPH S RMY 39 2/12 44/30/37/+10/0.00/0.0/.../.. 39 W AERO 37 MPH S RMY 39 2/13 42/27/35/+7/T/T/.../.. 22 W AERO 17 MPH W RMY N/A 2/14 43/29/36/+8/T/0.1/.../.. 21 NNW AERO 16 MPH NNW RMY N/A 2/15 the morning low temp: 29F; the normal low is now 19F DAILY RECORDS FOR FEBRUARY 2013 2/8 - NEW RECORD DAILY SNOWFALL OF 16.1 INCHES; surpasses the previous record of 11.0 inches in 1891 2/8 - TIED DAILY RECORD PEAK WIND GUST OF 63e MPH NE IN 1945 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR FEBRUARY 15 HIGH 60F IN 1954 LOW -18F IN 1943 PRECIP 1.28 INCHES IN 1950 SNOWFALL 11.2 INCHES IN 1940 PEAK GUST 94e MPH WNW IN 1946 RECORDS FOR FEBRUARY 16 HIGH 62F IN 1954 LOW -16F IN 1943 PRECIP 1.91 INCHES IN 1958 SNOWFALL 18.6 INCHES IN 1958 PEAK GUST 78 MPH W IN 1967 TODAY'S REPORT PREPARED BY: Sean Fankhauser