BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, APRIL 9, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME TEMPERATURE REACHES LOWER 70S THIS AFTERNOON; WARMTH OF PAST 2 DAYS PUSHES APRIL DEPARTURE INTO POSITIVE TERRITORY Yesterday's warmth all but eliminated the remaining negative temperature departure for the month of April. Today's warmth is picking up where yesterday's warmth left off. It's been a few degrees warmer today, with an afternoon high pushing into the lower 70s. This is the first 70+ degree temperature reading since October 20, 2012. Today's average temperature will likely finish close to 15 degrees above the 30-year normal, pushing April solidly into positive temperature departure territory. Early this morning, a few light rain showers and even a brief thunderstorm brought only a trace of precipitation to the summit. The summit soon became shrouded in fog, reducing visibility to 1/4 mile. The fog began dissipating rather quickly, with the first glimpse of sun just before 9 A.M. EDT. Winds that were SSE early this morning have become W this afternoon with the passage of a cold front shortly before 11 A.M. EDT. Winds are gusting in the 25-35 mph range, with a peak wind for the day so far of 35 mph. Today's observations: 7 A.M. Weather: Sky obscured by dense fog, stratus drifting over summit Temperature: 47F; Dew Point: 46F; Wind: S at 10 kts. Sea-level pressure: 29.91 ins. Hg, rising then falling Visibility: 1/4 mile, dense fog 24-hr precip: Trace 6-hr precip: Trace 6-hour min. temp: 45F BHO SA 1155 W3 X 1/4F 130/47/46/1910/991/ STRA DRFTNG OVR SMT/ 8//// 58014 MANUAL 7000/ MANUAL 6000/ 10047 20045 10 A.M. Weather: Scattered altocumulus, scattered cirrostratus, few cumulus/ cumulus fractus forming distant WSW-NNE, cirrostratus distant N-NE, thin smoke/haze layer distant all quadrants, hazy Temperature: 62F; Dew Point: 50F; Wind: W at 10 kts, Wind: Direction variable SW-WNW Wind: Direction gradually veering (clockwise) Sea-level pressure: 29.89 ins. Hg, falling Visibility: 20 miles, lower W-N-E, higher E-S-W, hazy BHO SA 1455 140 SCT 200 SCT 20 123/62/50/2710/989/ FEW CU/CUFRA FRMG DSNT WSW-NNE CS DSNT N-NE THN K/HZ LYR DSNT ALQDS HAZY VSBY W-N-E LWR E-S-W HIER WND 22V30 WND GRDLY VEERING/ 8/178 55007 1 P.M. Weather: Scattered cumulus/cumulus fractus/stratocumulus, scattered thin cirrus, broken thin cirrus, cumulus/cumulus fractus/stratocumulus mostly distant NW-ENE, few small cumulus/cumulus fractus E-S-NW, stratocumulus distant NNW-NNE, thin smoke/haze layer distant N-E-S, distant haze Temperature: 71F; Dew Point: 46F; Wind: W at 17G27 kts, Wind: Peak wind 29 kts. from the W at 12:17 P.M. Wind: Direction variable WSW-NW Sea-level pressure: 29.89 ins. Hg, falling then rising Visibility: 60 miles, NW 70 miles, N-E-SW lower, distant haze 6-hour max. temp: 71F BHO SA 1755 40 SCT 250 ñSCT 300 ñBKN 60 123/71/46/2817G27/989/ CU/CUFRA/SC MSTLY DSNT NW-ENE FEW SML CU/CUFRA E-S-NW SC DSNT NNW-NNE THN K/HZ LYR DSNT N-E-S DSNT HZ VSBY NW 70 N-E-SW LWR PK WND 2729/17 WND 25V32/ 8/501 55000 10071 20047 WEATHER SUMMARY FOR MONDAY, APRIL 8 TEMPERATURE (DEGREES F) MAX.....65 NORMAL.....53 MIN.....43 NORMAL.....35 MEAN....54 NORMAL.....44 DEPARTURE FROM 30-YEAR NORMAL...................+10 TOTAL DEPARTURE FOR THE MONTH....................+1 [-0.1 DEGREE/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............11 DEPARTURE.........-10 TOTAL HEATING UNITS FOR THE MONTH...........180 DEPARTURE..........-1 TOTAL HEATING UNITS FOR THE SEASON.........5200 DEPARTURE........-465 TOTAL HEATING UNITS LAST SEASON TO DATE....4456 DIFFERENCE.......+744 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............29 SSW AT 12:09 A.M. AERO....................22 SSW AT 12:09 A.M. ASOS....................28 SSW AT 12.09 A.M. DAVIS...................28 SSW AT 12-1 A.M. RMY: N/A THE FASTEST MILE FOR YESTERDAY.............21 SSW AT 12:08 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE..............21 SSW AT 1:33 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............20 SSW AT 12-1 A.M. AVERAGE WIND SPEED AND DIRECTION.........11.3 SE ASOS..................10.3 DAVIS.................10.7 SSW [202 deg] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace DEPARTURE...........-0.16 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.34 DEPARTURE...........-1.01 ASOS..............0.35 TOTAL PRECIPITATION FOR THE YEAR..........14.43 DEPARTURE...........-0.92 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............-0.2 TOTAL SNOWFALL FOR THE MONTH.............Trace DEPARTURE............-1.4 TOTAL SNOWFALL FOR THE SEASON.............99.0 DEPARTURE...........+37.9 PRELIMINARY CLIMATE SUMMARY FOR APRIL 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 4/1 61/31/46/+5/0.34/0.0/458/60 40 W AERO 44 MPH WNW RMY 46 4/2 40/27/34/-7/T/T/460/460/60 45 W AERO 42 MPH W RMY 47 4/3 45/27/36/-6/0.00/0.0/755/98 44 W AERO 43 MPH W RMY 47 4/4 55/26/41/-1/0.00/0.0/719/93 30 WSW AERO 27 MPH WSW RMY 31 4/5 59/36/48/+5/0.00/0.0/403/52 33 NNW AERO 28 MPH NNW RMY 38 4/6 47/30/39/-4/0.00/0.0/747/96 38 NW AERO 35 MPH NW RMY 40 4/7 52/31/42/-1/0.00/0.0/.../.. 51 S AERO 46 MPH S RMY 50 4/8 65/43/54/+10/T/0.0/.../.. 29 SSW AERO 22 MPH SSW RMY N/A 4/9 the morning low temp: 45F; the normal low is now 35F DAILY RECORDS FOR APRIL 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 9 HIGH 83 IN 1991 LOW 18 IN 1888 PRECIP 2.38 IN. IN 1935 SNOWFALL 11.0 IN. IN 1917 PEAK GUST 72 MPH WNW IN 1962 RECORDS FOR APRIL 10 HIGH 83 IN 1922 LOW 20 IN 1985 PRECIP 2.40 IN. IN 1935 SNOWFALL 10.1 IN. IN 1996 PEAK GUST 66 MPH WNW IN 1967 TODAY'S REPORT PREPARED BY: Sean Fankhauser