BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, JANUARY 25, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME CONTINUED COLD AND VERY DRY Today marks our 5th consecutive day of below normal temperatures. But, temperatures are finally beginning to moderate somewhat. The past 5 days have averaged about 11 degrees below normal. Despite the significant cold spell, the average for January remains nearly 5 degrees above normal. Winds have slackened this afternoon, but were quite brisk this morning. Winds of 15-25 mph with gusts over 30 mph at times produced wind chill readings of -10F to -20F this morning. High clouds have been increasing in coverage and thickening throughout the day. A weak disturbance is tracking well to our south, spreading clouds and a tiny bit of moisture our way. While still incredibly dry, dew point temperatures have inched up a little today, but remain below zero. Depending on how the weather plays out over the next few days, January 2013 is in the running for the driest January on record. The current record stands at 0.89 inch of precipitation in 1955. We've only had 0.69 inch so far this month. Today's observations: 7 A.M. Weather: Scattered altocumulus, scattered dense cirrus, broken thin cirrus, stratocumulus/cumulus layer with a few moderate tops along/offshore distant NE-ESE, altocumulus/altocumulus lenticularis S-NW, few patches of dense cirrus, thin smoke layer distant S-NW-NE, light distant haze Temperature: 5F; Dew Point: -7F; Wind: W at 13 kts, Windchill: -13F Sea-level pressure: 30.27 ins. Hg, rising slightly Visibility: 60 miles, light distant haze Snow depth: Trace 6-hour min temp: 4F BHO SA 1155 160 SCT 220 SCT 250 –BKN 60 250/5/-7/2813/027/ SC/CU LYR FEW MDT TOPS ALG/OFFSHR DSNT NE-ESE AC/ACSL S-NW FEW PTCHS DNS CI THN K LYR DSNT S-NW-NE LGT DSNT HZ WNDCHILL -13F/ 8/542 51003 10007 20004 10 A.M. Weather: Scattered cirrostratus, scattered dense cirrus, broken thin cirrus, few cumulus/stratocumulus along/offshore distant NE-ESE, few altocumulus/altocumulus lenticularis distant ESE-S, patches of dense cirrus ESE-WSW, light distant haze Temperature: 14F; Dew Point: -6F; Wind: WNW at 17G22 kts, Wind: Direction variable W-NW Windchill: -3F Sea-level pressure: 30.29 ins. Hg, rising BHO SA 1455 200 SCT 220 SCT 250 –BKN 75 259/14/-6/2917G22/029/ FEW CU/SC ALG/OFFSHR DSNT NE-ESE FEW AC/ACSL DSNT ESE-S PTCHS DNS CI ESE-WSW LGT DSNT HZ WND 26V32 WNDCHILL -3F/ 8/547 51009 1 P.M. Weather: Broken cirrostratus, broken cirrus, few cumulus/stratocumulus along/offshore distant NE-E, higher cirrus layer partly thin, partial halo, thin smoke layer distant NE-ESE and distant WNW-NNW, light distant haze Temperature: 22F; Dew Point: -5F; Wind: WNW at 11 kts, Wind: Direction variable W-NW Sea-level pressure: 30.23 ins. Hg, falling Visibility: 75 miles, light distant haze 6-hour max temp: 22F BHO SA 1755 E200 BKN 250 BKN 75 237/22/-5/2911/023/ FEW CU/SC ALG/OFFSHR DSNT NE-E HIER CI LYR PRTLY THN PARTIAL HALO THN K LYR DSNT NE-ESE AND DSNT WNW-NNW LGT DSNT HZ WND 26V32/ 8/507 58022 10022 20005 WEATHER SUMMARY FOR THURSDAY, JANUARY 24 TEMPERATURE (DEGREES F) MAX.....17 NORMAL.....34 MIN......0 NORMAL.....17 MEAN.....9 NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL......................-16 TOTAL DEPARTURE FOR THE MONTH.....................+117 [+4.7 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............56 DEPARTURE.........+16 TOTAL HEATING UNITS FOR THE MONTH...........832 DEPARTURE........-117 TOTAL HEATING UNITS FOR THE SEASON.........2860 DEPARTURE........-393 TOTAL HEATING UNITS LAST SEASON TO DATE....2581 DIFFERENCE.......+279 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............43 WNW AT 3:54 P.M. AERO....................39 WNW AT 3:54 P.M. ASOS....................43 WNW AT 3:54 P.M. DAVIS...................42 WNW AT 3:54 P.M. RMY 44 THE FASTEST MILE FOR YESTERDAY.............29 WNW AT 5:39 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE..............28 WNW AT 5:19 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............27 WNW AT 3:48 P.M. AVERAGE WIND SPEED AND DIRECTION.........16.6 WNW ASOS..................15.0 DAVIS.................14.6 WNW [295 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..........0.69 DEPARTURE..........-2.71 ASOS..............0.66 TOTAL PRECIPITATION FOR THE YEAR...........0.69 DEPARTURE..........-2.71 ASOS..............0.66 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE............-0.5 TOTAL SNOWFALL FOR THE MONTH...............4.5 DEPARTURE............-8.8 TOTAL SNOWFALL FOR THE SEASON.............19.9 DEPARTURE............-9.4 PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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 1/1 35/18/27/0/0.00/0.0/313/57 44 WNW AERO 44 MPH WNW RMY 45 1/2 29/11/20/-7/0.00/0.0/457/83 35 WNW AERO 35 MPH WNW RMY 33 1/3 23/2/13/-13/0.00/0.0/529/96 24 WNW AERO 23 MPH WNW RMY 23 1/4 38/19/29/+3/0.00/0.0/320/58 35 W AERO 36 MPH W RMY 36 1/5 40/27/34/+8/0.00/0.0/536/97 36 WNW AERO 37 MPH WNW RMY 38 1/6 42/27/35/+9/T/0.1/471/85 29 SW AERO 29 MPH SW RMY 29 1/7 38/27/33/+7/0.00/0.0/538/97 29 NW AERO 27 MPH NW RMY N/A 1/8 45/27/36/+10/0.00/0.0/428/77 39 SW AERO 42 MPH SW RMY 41 1/9 42/31/37/+11/T/0.0/033/06 40 W AERO 39 MPH W RMY N/A 1/10 45/32/39/+14/0.00/0.0/548/98 47 WNW AERO 48 MPH WNW RMY 50 1/11 38/29/34/+9/0.15/0.0/050/09 23 SE AERO 21 MPH SE RMY 23 1/12 43/35/40/+15/0.02/0.0/000/00 21 SE AERO 18 MPH SE RMY 15 1/13 50/41/46/+21/0.01/0.0/000/00 30 SW AERO 30 MPH SW RMY N/A 1/14 59/40/50/+25/T/0.0/175/31 36 S AERO 37 MPH S RMY 39 1/15 40/33/37/+12/T/0.0/045/08 17 N AERO 16 MPH NNW RMY 17 1/16 33/29/31/+6/0.45/3.5/000/00 16 NNE AERO 14 MPH N RMY 15 1/17 39/28/34/+9/0.00/0.0/519/91 36 WNW AERO 35 MPH WNW RMY 32 1/18 28/16/22/-3/0.00/0.0/566/99 39 NW AERO 39 MPH NW RMY 43 1/19 47/21/34/+9/0.00/0.0/350/61 46 SSW AERO 45 MPH SSW RMY 48 1/20 52/26/39/+14/0.00/0.0/408/71 48 SW AERO 52 MPH SW RMY 51 1/21 26/18/22/-3/0.06/0.9/144/25 35 WNW AERO 32 MPH WNW RMY N/A 1/22 23/10/17/-8/T/T/544/94 35 WNW AERO 30 MPH WNW RMY 35 1/23 15/4/10/-15/0.00/0.0/569/98 39 W AERO 35 MPH W RMY 37 1/24 17/0/9/-16/0.00/0.0/.../.. 43 WNW AERO 39 MPH WNW RMY 44 1/24 morning low temp: 4F; the normal low is now 17F DAILY RECORDS FOR JANUARY 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 25 HIGH 56F IN 2010 LOW -10F IN 1935 PRECIP 2.24 INS. IN 1979 SNOWFALL 12.5 INS. IN 1941 PEAK GUST 81 MPH WNW IN 1972 RECORDS FOR JANUARY 26 HIGH 68F IN 1950 [RECORD FOR MONTH] LOW -5F IN 1920 PRECIP 1.60 INS. IN 1958 SNOW 9.0 INS. IN 1898 WIND 90e MPH SE IN 1978 TODAY'S REPORT PREPARED BY: Sean Fankhauser